JP2000220570A - Plunger pump and brake device using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain necessary pressure only when necessary with a simple structure. SOLUTION: This device is provided with a voice coil motor 14 for driving a plunger 13 by a magnetic force, a stroke detecting means 66 for detecting the stroke position of the plunger 13, and a switching means for reverse- controlling the direction of a current flowing to the voice coil motor 14 according to the detecting result of the stroke detecting means 66. Thus, the voice coil motor 14 reciprocates the plunger 13 by a magnetic force, and liquid introduced through an introduction side check valve 23 to a liquid chamber 45 is discharged through a discharge side check valve 24.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plunger pump for generating hydraulic pressure by reciprocating a plunger and a brake device using the same.

[0002]

2. Description of the Related Art Various types of electronically controlled hydraulic brake devices for controlling brake hydraulic pressure by electric signals have been developed. One example is shown in FIG. This electronically controlled hydraulic brake system
A brake pedal 200; a tread force sensor 201 for detecting an input to the brake pedal 200;
A master cylinder 202 for generating a brake hydraulic pressure by inputting 0, a stroke simulator 203 for absorbing the brake hydraulic pressure generated by the master cylinder 202 and applying a reaction force corresponding to the depression to the brake pedal 200; Failure of master cylinder 20
And an NC valve 204 for preventing the brake fluid pressure generated in 2 from being introduced into the stroke simulator 203. A reservoir tank 205 for storing brake fluid; a pump 206 for sucking brake fluid from the reservoir tank 205 to generate brake fluid pressure; an accumulator 207 for storing brake fluid pressure generated by the pump 206; A relief valve 208 for releasing the fluid pressure on the 207 side to the reservoir tank 205 side as needed. Further, calipers 209, 209,... Provided for each wheel to generate a braking force, and provided for each of the calipers 209, 209,... To control the communication between the corresponding caliper 209 and the accumulator 207. , And an electromagnetic switching type pressure-intensifying valve 210 for controlling the pressure of the brake fluid supplied to the caliper 209, and a corresponding one of the calipers 209, 209,. By controlling the communication between the caliper 2
, 209, 209,... Are provided for the respective calipers 209, 209,... And the supply source of the brake hydraulic pressure to the corresponding calipers 209 is a master cylinder. And a switching valve 212 of an electromagnetic switching type for switching to one of the accumulator 202 and the accumulator 207. In addition, a pressure sensor 213 provided for each of the calipers 209, 209,... For detecting the brake fluid pressure of the corresponding caliper 209, a relief valve 208, and a pressure increasing valve 210, 21
, And a pressure sensor 214 for detecting the brake fluid pressure during this period. In such an electronically controlled hydraulic brake device, a normal plunger pump in which an eccentric shaft is rotated by a motor and a plunger is reciprocated by the eccentric shaft is used as the pump 206. This plunger pump has a structure suitable for efficiently obtaining a high pressure. However, while the pressure required for a normal brake operation with a deceleration of about 0.3 G is about 3 MPa,
A high pressure of 13 MPa or more is used. This is because it is necessary to accumulate the required pressure in the accumulator in advance as described above, since the starting time of the pump is required due to the rotor inertia of the motor.

[0003]

As described above, the plunger pump used in the conventional electronically controlled hydraulic brake system has a problem that the hydraulic pressure is generated more than necessary. In addition, conventional electronically controlled hydraulic brake devices
A large number of valves are required to generate low pressure, resulting in a complex system with a large number of parts. Specifically, as described above, 13 electromagnetic valves and 5 pressure sensors are required. Therefore, the present invention
It is an object of the present invention to provide a plunger pump that can achieve a required pressure only when needed with a simple configuration, and a brake device using the plunger pump.

[0004]

According to a first aspect of the present invention, there is provided a plunger pump comprising: a cylinder; a plunger reciprocally inserted into the cylinder; A liquid chamber whose volume is increased or decreased by the reciprocating motion of the plunger, an inlet check valve that allows only the flow of the liquid to the liquid chamber, and a discharge that allows only the flow of the liquid from the liquid chamber. A voice coil motor for driving the plunger by magnetic force, stroke detection means for detecting a stroke position of the plunger, and detecting the direction of a current flowing through the voice coil motor by the stroke detection. Switch means for performing inversion control according to the detection result of the means. Thus, while the stroke position of the plunger is detected by the stroke detecting means, the switch means reversely controls the direction of the current flowing through the voice coil motor according to the stroke position, so that the voice coil motor reciprocates the plunger with the magnetic force. Will be. Thus, while the thrust is proportional to the current,
The plunger is reciprocated with a voice coil motor that can keep the thrust in the stroke constant and can respond faster.
The volume of the liquid chamber is increased or decreased by the reciprocating motion of the plunger, and the liquid introduced into the liquid chamber through the introduction-side check valve is discharged through the discharge-side check valve.

According to a second aspect of the present invention, there is provided the plunger pump according to the first aspect, wherein the liquid chamber has a first liquid whose volume increases by one-way movement of the plunger and decreases by a reverse movement. And a second liquid chamber whose volume is reduced by the one-way movement of the plunger and whose volume is increased by the reverse movement, and the introduction-side check valve is provided in each of the first liquid chamber and the second liquid chamber. And the discharge-side check valve is provided. Thus, while the stroke detecting means detects the stroke position of the plunger, the switch means reversely controls the direction of the current flowing through the voice coil motor in accordance with the stroke position, so that the voice coil motor reciprocates the plunger with the magnetic force. Then, in one direction movement, the plunger increases the volume of the first liquid chamber and decreases the volume of the second liquid chamber, and in the reverse direction movement, the plunger reduces the volume of the first liquid chamber and the second liquid chamber. The volume of the chamber is increased, and as a result, the pressurized liquid can be discharged twice in one reciprocation of the plunger.

According to a third aspect of the present invention, there is provided a brake device comprising:
3. The plunger pump according to claim 1, an operation amount detection unit that detects an operation amount of a brake pedal, a braking force generation unit that generates a braking force by a hydraulic pressure generated by the plunger pump, and the operation amount. Control means for controlling the plunger pump based on the detection result of the detection means. Thus, when the operation amount of the brake pedal is detected by the operation amount detection means, the control means moves the plunger of the voice coil motor back and forth by magnetic force based on the detection result, and the reciprocation of the plunger causes the volume of the liquid chamber to change. Is increased or decreased, and the liquid introduced into the liquid chamber through the introduction-side check valve is discharged through the discharge-side check valve to introduce the hydraulic pressure to the braking force generating means. In this way, the thrust is proportional to the current, the thrust within the stroke can be made constant, and the plunger is reciprocated by the voice coil motor that can respond at a high speed, and the volume of the liquid chamber is increased or decreased by the reciprocation of the plunger. Since a plunger pump for discharging the liquid introduced into the liquid chamber through the introduction-side check valve through the discharge-side check valve is used, an accumulator, a relief valve, a pressure-intensifying valve, and a pressure sensor are not required. .

According to a fourth aspect of the present invention, there is provided a brake device comprising:
4. The control device according to claim 3, wherein the control unit supplies a current to the voice coil motor only when a target hydraulic pressure based on a detection result of the operation amount detecting unit is higher than a hydraulic pressure of the braking force generating unit. And As described above, since the current flows through the voice coil motor only when the target hydraulic pressure based on the detection result of the operation amount detecting means is higher than the hydraulic pressure of the braking force generating means, the energy consumption can be further reduced.

[0008]

FIG. 1 shows a first embodiment of the present invention.
This will be described below with reference to FIGS. First, the plunger pump 11 will be described. The plunger pump 11
It has a cylinder 12, a plunger 13 reciprocally inserted into the cylinder 12, and a voice coil motor 14 for reciprocating the plunger 13.

The cylinder 12 has a cylinder hole 15 from one side.
Is formed into a substantially cylindrical shape with a bottom by being formed to an intermediate predetermined position. The cylinder hole 15 has a large-diameter hole portion 16 having a large diameter on the opening side and a small diameter having a smaller diameter than the large-diameter hole portion 16 on the bottom side. The hole 17 has a stepped shape. Cylinder 1
2, a pair of introduction passages 18 and a discharge passage 19 for separately communicating the outer diameter side and the bottom side of the cylinder hole 15 are formed along the radial direction of the cylinder 12.

The cylinder 12 has a communication passage 20 having an opening at one end at a predetermined position of the introduction passage 18 and an opening at the other end at a predetermined position in the small-diameter hole 17 of the cylinder hole 15. ing. Further, the cylinder 12 has a shape in which one end opening is arranged at a predetermined position of the large diameter hole 16 of the cylinder hole 15 and the other end is arranged on the same side as the opening of the large diameter hole 16 in the axial direction. Air passage 21 is formed.

The introduction passage 18 is provided in the introduction passage 1.
An inlet check valve 23 that allows the flow of the liquid from 8 to the direction of the cylinder hole 15 and prevents the flow of the liquid in the opposite direction is provided closer to the cylinder hole 15 than the opening position of the communication passage 20. The discharge passage 19 is provided with a discharge-side check valve 24 that allows the flow of the liquid from the cylinder hole 15 toward the discharge passage 19 and prevents the flow of the liquid in the opposite direction.

The introduction-side check valve 23 includes a valve base 26 having a smaller diameter than the other portion formed in the introduction passage 18 on the outside diameter side of the cylinder hole 15 by a predetermined amount, and the valve in the introduction passage 18. A spherical valve body 27 movably housed in the cylinder hole 15 side from the base 26, and a spring member (not shown) for urging the valve 27 in a direction of closing the introduction passage 18 by contacting the valve 27 with the valve base 26. And

The discharge-side check valve 24 has a valve seat 28 having a smaller diameter than the other portion formed in the discharge passage 19 near the cylinder hole 15, and a cylinder hole 15 of the valve seat 28 in the discharge passage 19. And a spherical valve element 29 housed movably on the opposite side to the valve body, and a spring member (not shown) that abuts the valve element 29 on the valve base 28 and urges the discharge passage 19 in the closing direction. ing.

On the side opposite to the introduction passage 18 and the discharge passage 19 in the axial direction of the cylinder 12, a cylindrical portion 31 is provided.
Cylindrical yoke 33 having a bottom and a bottom 32
However, it is fixed coaxially with the cylinder hole 15 in a state where the opposite side to the bottom 32 of the cylindrical portion 31 is arranged on the cylinder 12 side. A guide hole 34 is formed through the bottom 32 of the outer yoke 33 so as to be coaxial therewith.

The plunger 13 has a small-diameter shaft portion 36 formed on the distal end side, a large-diameter shaft portion 37 formed adjacent to the small-diameter shaft portion 36 and having a larger diameter than the small-diameter shaft portion 36, and a large-diameter shaft portion. A first connecting shaft 38 having the same diameter as the small-diameter shaft 36 formed on the opposite side of the small-diameter shaft 36 and the first connecting shaft 38;
A guide shaft portion 39 having a diameter larger than the first connection shaft portion 38 and smaller than the large diameter shaft portion 37 formed adjacent to the large diameter shaft portion 37 on the opposite side, and a first connection shaft of the guide shaft portion 39. A second connecting shaft portion 40 having the same diameter as the first connecting shaft portion 38 formed adjacent to and opposite to the portion 38 is provided.

On the opposite side of the guide shaft 39 of the second connecting shaft 40, which is the other end of the plunger 13, the guide shaft 3
An iron piece 41 larger in diameter than 9 and smaller in diameter than the large-diameter shaft portion 37 is fixed coaxially. A ring-shaped guide member 42 is fixed to the large-diameter shaft portion 37.

When the small-diameter shaft portion 36 is positioned inside the small-diameter hole portion 17 of the cylinder hole 15, the plunger 13 moves the guide member 42 of the large-diameter shaft portion 37 inside the large-diameter hole portion 16 of the cylinder hole 15. And the guide shaft 39 is slidably fitted in the guide hole 34 of the outer yoke 33 so that the cylinder 12 can be reciprocally supported without misalignment. Become. A ring-shaped seal member 44 for closing a gap between the small-diameter hole portion 17 of the cylinder hole 15 and the small-diameter shaft portion 36 of the plunger 13 is fixed. It is slidable.

As described above, the cylinder hole 15, the portion of the introduction passage 18 on the introduction side check valve 23 side, and the introduction side check valve 23
The discharge-side check valve 24, the seal member 44, and a part of the plunger 13 protruding from the seal member 44 define a liquid chamber 45 whose volume increases and decreases due to reciprocation of the plunger 13. Become. Then, the introduction-side check valve 23 allows only the flow of the liquid to the liquid chamber 45, and the discharge-side check valve 24 allows only the flow of the liquid from the liquid chamber 45.

A step portion 47 serving as the bottom of the large-diameter hole portion 16 of the cylinder hole 15 and a small-diameter shaft portion 36 of the large-diameter shaft portion of the plunger 13.
An extendable bellows 49 is mounted between the end face 48 and the side end face 48. This bellows 49
The inside of the large-diameter hole portion 5 of FIG. 5 is divided into a chamber 50 on the inner peripheral surface side of the cylinder hole 15 and constantly communicating with the atmosphere passage 21 and a chamber 51 on the plunger 13 side and constantly communicating with the communication passage 20. It is densely defined and prevents liquid leakage from the chamber 51 side to the chamber 50 side.

Inside the outer yoke 33, a cylindrical inner yoke 53 is coaxially fixed to the bottom 32. The plunger 13 is inserted inside the inner yoke 53, and a cylindrical magnet 54 for forming a magnetic path is coaxially fixed to the outer diameter side of the inner yoke 53.

A VCM coil 56 is arranged between the outer diameter side of the magnet 54 and the inner diameter side of the cylindrical portion 31 of the outer yoke 33. The VCM coil 56 is located closer to the cylinder 12 than the magnet 54.
Is fixed to the large-diameter shaft 37 side of the first connection shaft 38. In addition, the electric wire 5 for flowing current to the VCM coil 56
7 is a hole 5 formed in the cylindrical portion 31 of the outer yoke 33.
8 leads to the outside.

The above plunger 13 and outer yoke 3
3, the inner yoke 53, the magnet 54, and the VCM coil 56 constitute the voice coil motor 14 that drives the plunger 13 by magnetic force.

On the opposite side of the outer yoke 33 with respect to the cylinder 12, a substantially bottomed cylindrical stroke sensor cover 64 having a cylindrical portion 62 and a bottom 63 is provided. The opposite side of the bottom 63 of the cylindrical portion 62 is located on the outer yoke 33 side. And is fixed coaxially with the outer yoke 33. The iron piece 41 described above is arranged inside the stroke sensor cover 64.

A stroke sensor (stroke detecting means) 66 is fixed to the inner peripheral surface of the stroke sensor cover 64. The stroke sensor 66 includes a bias magnet (not shown) and a pair of Hall elements 67 and 68 which are disposed at predetermined positions in the axial direction of the plunger 13 while being separated from each other, as shown in FIG.
And an IC 69 having a comparison circuit with hysteresis for differentially amplifying the outputs of the Hall elements 67 and 68. The stroke sensor 66 detects that the iron piece 41 is located at a predetermined position on one Hall element 67 side and that the iron piece 41 is located at a predetermined position on the other Hall element 68 side. Stroke position is detected.

The stroke sensor 66 is shown in FIG.
As shown in (b), the Hall element 67 on the cylinder 12 side
An L signal is output from the time when the iron piece 41 is detected at a predetermined position on the side to the time when the iron piece 41 is detected at a predetermined position on the Hall element 68 side opposite to the cylinder 12. However, from the point in time when it is detected that the iron piece 41 is located at a predetermined position on the Hall element 68 side opposite to the cylinder 12, it is detected that the iron piece 41 is located at a predetermined position on the Hall element 67 side on the cylinder 12 side. Until the output, an H signal is output. The electric wire 70 for extracting the signal of the stroke sensor 66 is connected to the stroke sensor cover 6.
4 is led out from a hole 71 formed in the cylindrical portion 62.

The stroke sensor 66 supplies a current to the voice coil motor 14 and determines the direction of the current to the stroke sensor 66.
Is connected to a drive circuit (control means) 73 for causing the voice coil motor 14 to reciprocate in a self-excited manner by causing the voice coil motor 14 to reciprocate by flowing while performing inversion control in accordance with the detection result.

The drive circuit 73 includes a stroke sensor 6
6, the iron piece 41 is placed at a predetermined position on one of the Hall elements 67 side.
At the time when the state where is located is detected and the other Hall element 6
The direction of the current flowing through the VCM coil 56 is reversed at each time when the state in which the iron piece 41 is located at the predetermined position on the side of the Hall element 67 is thereby reversed. Is a moving end on one side of the reciprocating motion of the plunger 13, and a state where the iron piece 41 is located at a predetermined position on the other Hall element 68 side is a moving end on the other side of the reciprocating motion of the plunger 13, The plunger 13 reciprocates between these moving ends. The driving circuit 7
Details of 3 will be described later.

The plunger pump 11 having such a configuration
When the plunger 13 is reciprocated by the voice coil motor 14 while the introduction passage 18 communicates with the liquid supply source side and the discharge passage 19 communicates with the liquid supply destination, the plunger 13 moves in one direction (right direction in FIG. 1). Due to the expansion of the volume in the liquid chamber 45 due to the movement to the position, the introduction-side check valve 23 is opened while the discharge-side check valve 24 is closed, and the liquid is introduced into the liquid chamber 45 from the liquid supply source. You. The liquid chamber 45 due to the subsequent movement of the plunger 13 in the opposite direction (left direction in FIG. 1)
Due to the reduction of the internal volume, the discharge-side check valve 24 is opened while the introduction-side check valve 23 is closed, and the pressure liquid is discharged from the liquid chamber 45 to the liquid supply destination. By repeating such reciprocation, the pressure liquid is discharged from the liquid supply source to the liquid supply destination.

Next, a brake device 75 to which the plunger pump 11 is applied will be described with reference to FIG. The brake device 75 includes a brake pedal 76 operated by a driver, and a tread force sensor (operation amount detection means) 7 that detects a tread force as an operation amount of the brake pedal 76.
7, a master cylinder 78 that generates a brake fluid pressure according to the input of the brake pedal 76, and absorbs the brake fluid pressure generated by the master cylinder 78 and applies a reaction force corresponding to the depression to the brake pedal 76. And a NC for preventing the brake fluid pressure generated in the master cylinder 78 from being introduced into the stroke simulator 79 when the system fails.
And a valve 80.

The brake device 75 includes a reservoir tank 81 for storing brake fluid, calipers (braking force generating means) 82 provided for each wheel to generate a braking force,
, And the plunger pumps 11, 11,..., Which are provided for the respective calipers 82, 82,... To suck the brake fluid from the reservoir tank 81 and introduce the brake fluid pressure to the corresponding calipers 82. Caliper 8
, 82,... Are connected to the corresponding caliper 82 and the reservoir tank 81 to control the pressure of the brake fluid supplied to the caliper 82 to reduce the brake fluid pressure. , 83,... And an electromagnetic switching type for switching the supply source of the brake fluid pressure to the corresponding caliper 82 to one of the master cylinder 78 and the plunger pump 11. .. Are provided.

That is, the conventional brake device does not require an accumulator, a relief valve, a pressure increasing valve for each caliper, a pressure sensor for each caliper, and a pressure sensor between the relief valve and the pressure increasing valve. Has become. The plunger pump 11 connects the introduction passage 18 to the reservoir tank 8.
1 and the discharge passage 19 is in communication with the caliper 82.

As shown in FIG. 4, the voice coil motor 1
The drive circuit 73 for self-exciting and reciprocating the motor 4 includes a current detection resistor 86 for detecting a current, a DC feedback amplifier 87 for amplifying a terminal voltage g of the current detection resistor 86, and a tread force sensor 7.
Error amplifier 88 for amplifying the error between the pedaling force signal (target pressure signal) f output from 7 and the current feedback signal, and drive element 89 for controlling the current flowing through current detection resistor 86
And switch elements 90 to surround the VCM coil 56 in an H shape.
93 and a logic circuit 94 that generates signals be for controlling ON / OFF of the switch elements 90 to 93 from the signal a of the stroke sensor 66.

In the driving circuit 73, the current detecting resistor 8
6. A current control circuit 95 for controlling the value of the current flowing through the VCM coil 56 is constituted by the current feedback amplifier 87, the error amplifier 88, and the drive element 89, and the stroke sensor 66, the logic circuit 94, and the switch elements 90 to 93 ,
Switch circuit (switch means) 9 for controlling the direction of current
6 are constituted.

When the output a from the stroke sensor 66 is "H" as shown in the time chart of FIG. 5, that is, when the plunger 13 is on the opposite side (right side in FIG. When it is located halfway from the moving end including the moving end to the cylinder 12 side (left side in FIG. 1), the signal b to the switch element 90 and the signal e to the switch element 93 are turned on, while the stroke sensor 66 is turned on. Is "L", that is, the plunger 13 moves from the moving end including the moving end on the cylinder 12 side (left side in FIG. 1) to the opposite side (right side in FIG. 1) with respect to the cylinder 12. When it is located halfway, the signal c to the switch element 91 and the signal d to the switch element 92 are turned on.

When the pedaling force signal f from the pedaling force sensor 77 rises, the current control circuit 95 causes the terminal voltage g to rise and the current to flow through the VCM coil 56. The current control circuit 95 enters a state in which a current flows through the VCM coil 56. For example, the switch circuit 96 outputs a signal b to the switch element 90 and a signal e to the switch element 93 when the output a from the stroke sensor 66 is “H”. Are turned on, a current flows through the VCM coil 56 in a predetermined direction (for example, from left to right in FIG. 4). Then, the plunger 13 moves in the direction (left direction in FIG. 1) in which the plunger 13 is inserted into the cylinder 12 by the magnetic force.

As a result, the brake fluid in the fluid chamber 45 is discharged toward the caliper 82. When the output “a” from the stroke sensor 66 becomes “L” by the movement of the plunger 13, the switch circuit 96 outputs the signal “b” to the switch element 90.
And the signal e to the switch element 93 are turned off, and the signal c to the switch element 91 and the signal d to the switch element 92 are turned on. As a result, the VCM coil 56 is turned in the opposite direction (for example, from the right in FIG. 4). The current flows to the left. Then, the plunger 13 is moved to the cylinder 1 by magnetic force.
It moves in the direction (right direction in FIG. 1) that is pulled out of the second position. As a result, the brake fluid is introduced into the fluid chamber 45 from the reservoir tank 81.

When the output a from the stroke sensor 66 becomes "H" by the movement of the plunger 13, the drive circuit 7
3 is the signal c to the switch element 91 and the switch element 92
Signal d to the switch element 9 and the switch element 9
The signal b to 0 and the signal e to the switch element 93 are turned on, and as a result, the plunger 13 moves in the direction to be inserted into the cylinder 12. By repeating such reciprocating motion, the brake fluid pressure of the caliper 82 is increased to generate a braking force.

As shown in the timing chart of FIG. 5, when the pedaling force signal f from the pedaling force sensor 77 rises (the pedaling speed of the brake pedal 76 is positive), the plunger 13 of the plunger pump 11 reciprocates. In order to move the pedals, the stroke sensor 66 switches the switch elements 90 to 93, and the pedaling force signal f of the pedaling force sensor 77 is constant (state in which the brake pedal 76 is depressed at a speed of 0) and In a state where the pedal depression force signal f decreases (a state where the depression speed of the brake pedal 76 is negative), the plunger pump 11
In order to stop the plunger 13, the stroke sensor 66 does not perform the above-described switching of the switch elements 90 to 93, for example. Further, when the pedaling force signal f is reduced, the brake fluid pressure is released from the caliper 82 by separately opening the pressure reducing valve 83 to reduce the braking force.

The stroke sensor 66 switches the switch elements 90 to 93 only when the output pressure of the plunger pump 11 determined from the pedaling force signal f from the pedaling force sensor 77 has not reached the target pressure. When the output pressure of the plunger pump 11 has reached the target pressure, the switching may not be performed.

In the normal state, the brake device 75 sets the switching valves 84, 84,... To allow the caliper 82 to communicate with the plunger pump 11, and based on the output from the pedaling force sensor 77, Thus, the brake fluid pressure of the caliper 82 is controlled by controlling at least one of the plunger pump 11 and the pressure reducing valve 83. On the other hand, when an abnormality has occurred, the NC valve 80 is closed and the switching valves 84, 84,... Are brought into a state in which the caliper 82 communicates with the master cylinder 78, and the brake fluid pressure corresponding to the depression of the brake pedal 76 is reduced. Generated in the master cylinder 78 and introduced into the caliper 82.

According to the first embodiment described above,
When the depression force of the brake pedal 76 is detected by the depression force sensor 77, the drive circuit 73 detects the stroke position of the plunger 13 by the stroke sensor 66 based on the detection result, and flows to the voice coil motor 14 according to the stroke position. By reversing the direction of the current, the plunger 13 of the voice coil motor 14 is reciprocated by the magnetic force, and the volume of the liquid chamber 45 is increased or decreased by the reciprocating motion of the plunger 13 and introduced into the liquid chamber 45 from the reservoir tank 81. The liquid introduced through the side check valve 23 is discharged from the liquid chamber 45 through the discharge side check valve 24 to introduce a liquid pressure to the caliper 82.

As described above, the thrust is proportional to the current, the thrust within the stroke can be made constant, and the plunger 13 is reciprocated by the voice coil motor 14 capable of responding at a high speed. Since the plunger pump 11 that discharges the pressurized liquid by increasing or decreasing the volume of 45 is used, an accumulator, a relief valve, a pressure-intensifying valve, and a pressure sensor are not required, and therefore, the necessary pressure can be obtained only when necessary It can be realized with a simple configuration. Further, since there is no need to generate a pressure much higher than the pressure normally used, energy consumption can be reduced.

It should be noted that a target pressure converted from the pedal depression force is given instead of the pedal depression force signal f in FIG.
If a signal converter that gives a target pressure only when the target pressure is higher than the pressure of the caliper 82 and outputs “0” when the target pressure is equal to or lower than the pressure of the caliper 82 is added, As shown by the broken lines in the signals f and g of FIG.
The current to the VCM coil 56 can be reduced to zero, preventing the temperature of the plunger pump 11 from rising and further reducing energy consumption.

Here, FIG. 4 shows a case where a MOSFET is used as the drive element 89 and contacts are used as the switch elements 90 to 93.
It is also possible to use a driving element such as an OS, a transistor, or an IGBT.

Next, a second embodiment of the present invention will be described below with reference to FIGS. 6 and 7, focusing on differences from the first embodiment. The same parts as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted. The second embodiment partially differs from the first embodiment in the configuration of the plunger pump 11.

That is, the cylinder 1 of the second embodiment
2, a cylinder hole 15 is formed from one side to a predetermined intermediate position. As in the first embodiment, the cylinder hole 15 has a large-diameter hole portion 16 on the opening side and a large-diameter hole portion on the bottom side. It has a stepped shape with a small-diameter hole 17 having a smaller diameter than the diameter hole 16. The cylinder 12 has a radially extending introduction passage 18 penetrating from the outer diameter side to a predetermined position of the small-diameter hole portion 17 of the cylinder hole 15, and has a discharge passage coaxial with the cylinder hole 15. 19 is a large-diameter hole 16
Is formed so as to open to the opposite side.

Instead of the sealing member, a small-diameter shaft portion 36 of the plunger 13 similar to that of the first embodiment is replaced by an annular base 98 as shown in FIG. Annular support portion 9 extending to one side in the axial direction from
9 and a support portion 9 in the axial direction from the outer peripheral side of the base portion 98.
9 and a ring-shaped cup seal 101 having a U-shaped cross section having a ring-shaped opening / closing portion 100 extending on the same side.
It is fixed in. In addition, this cup seal 10
1 and a plunger 1 protruding from the cup seal 101
3, a liquid chamber 45 is defined by the bottom side of the cylinder hole 15 and the discharge-side check valve 24.

The cup seal 101 is connected to the liquid chamber 45.
When the pressure on the liquid chamber 45 side is higher than the pressure on the introduction passage 18 side, the opening / closing section 100 is pressed against the cylinder hole 15 to be in a sealed state. When the pressure on the introduction passage 18 side is higher than the pressure on the liquid chamber 45 side, the opening / closing unit 100 is separated from the cylinder hole 15 and is opened. As a result, the cup seal 101 constitutes an introduction-side check valve that allows the flow of the liquid from the introduction passage 18 toward the liquid chamber 45 and prevents the flow of the liquid in the opposite direction. Here, the position of the introduction passage 18 is set such that the introduction passage 18 is always located closer to the large-diameter hole 16 than the cup seal 101.

Further, between the discharge passage 19 and the cylinder hole 15, a discharge-side check valve for permitting the flow of the liquid from the cylinder hole 15 toward the discharge passage 19 and preventing the flow of the liquid in the reverse direction. 24 are provided. This discharge side check valve 24
Are moved between the discharge passage 19 and the smaller diameter hole 17 of the cylinder hole 15, and the valve seat 28 having a smaller diameter than the valve seat 28 is moved in the discharge passage 19 to the opposite side to the cylinder hole 15 of the valve seat 28. The valve body 29 has a spherical valve body 29 accommodated therein, and a spring member (not shown) that abuts the valve body 29 on the valve base 28 and urges the discharge passage 19 in the closing direction.

In the plunger pump 11 of the second embodiment having such a structure, the introduction passage 18 communicates with the liquid supply source side, that is, the reservoir tank 81 side, and the discharge passage 19 communicates with the liquid supply destination side, that is, the caliper 82 side. When the plunger 13 is reciprocated by the voice coil motor 14, the displacement of the plunger 13 in one direction (rightward in FIG. 6) increases the volume in the liquid chamber 45, so that the discharge-side check valve 24 closes. In this state, the cup seal 101 is opened, and the liquid is introduced from the reservoir tank 81 into the liquid chamber 45.

The subsequent movement of the plunger 13 in the opposite direction (to the left in FIG. 6) reduces the volume in the liquid chamber 45, so that the discharge side check valve 2 remains closed while the cup seal 101 remains closed.
4 is opened, and the pressure liquid is discharged from the liquid chamber 45 to the caliper 82. By repeating such reciprocation,
The pressurized liquid is discharged to the caliper 82.

Next, a third embodiment of the present invention will be described below with reference to FIG. 8, focusing on differences from the first embodiment. The same parts as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted. The third embodiment is different from the first embodiment in that the plunger pump 11
Are partially different.

That is, the cylinder 1 of the third embodiment
The second cylinder hole 15 includes a first small-diameter hole portion 103 on the bottom side,
An intermediate-diameter hole portion 104 formed adjacent to the first small-diameter hole portion 103 and having a larger diameter than the first small-diameter hole portion 103;
4 and a second small-diameter hole 105 having the same diameter as the first small-diameter hole 103 formed on the opposite side to the first small-diameter hole 103. Diameter hole 10
Large-diameter hole 1 similar to that of the first embodiment
6 are formed adjacent to each other. The diameter of the intermediate hole 104 is smaller than that of the large hole 16.

An introduction passage 18 is formed in the cylinder 12 along the radial direction so as to penetrate from the outer diameter side to a predetermined position on the side of the first small diameter hole 103 of the intermediate diameter hole 104 of the cylinder hole 15. ing. In addition, the cylinder 12 has a communication passage 20 having an opening at one end at a predetermined position of the introduction passage 18 and an opening at the other end at a predetermined position in the second small-diameter hole 105 of the cylinder hole 15. Is formed.

Further, the cylinder 12 has a cylinder bore 1
5 is coaxial with the first discharge passage 106 and the large-diameter hole 16
, And an opening is disposed at a predetermined position of the first discharge passage 106,
The second small diameter hole 10 of the intermediate diameter hole 104 of the cylinder hole 15
A second discharge passage 107 having an opening at the other end is formed on the fifth side. In addition, the cylinder 12 has an atmosphere passage 21 similar to that of the first embodiment.

The first discharge passage 106 is provided with a first discharge-side check valve 109 for allowing the flow of the liquid from the cylinder hole 15 toward the first discharge passage 106 and preventing the flow of the liquid in the reverse direction. Is provided. Also, the second discharge passage 107
In addition, a second discharge-side check valve 110 that allows the flow of the liquid from the cylinder hole 15 toward the second discharge passage 107 and prevents the flow of the liquid in the opposite direction is provided.

The first discharge-side check valve 109 includes a valve base 111 having a smaller diameter formed at the boundary between the first discharge passage 106 and the first small-diameter hole 103 of the cylinder hole 15, and a first discharge passage. Cylinder hole 15 of valve base 111 in 106
Valve body 112 housed movably on the opposite side to
And a spring member (not shown) for urging the valve body 112 against the valve base 111 to close the first discharge passage 106.

The second discharge-side check valve 110 has a valve base 113 having a smaller diameter than other portions formed in the second discharge passage 107.
And a spherical valve element 114 movably housed in the second discharge passage 107 on the opposite side to the cylinder hole 15 of the valve base 113, and the valve 114 is brought into contact with the valve base 113 to perform the second discharge. And a spring member (not shown) that urges the passage 107 in the closing direction.

The plunger 13 has a first small diameter shaft portion 116 on the distal end side having the same diameter as the first connecting shaft portion 38, instead of the small diameter shaft portion of the first embodiment, and the first small diameter shaft portion 116. And an intermediate shaft portion 117 having a diameter larger than the first small diameter shaft portion 116 and smaller than the large diameter shaft portion 37, and formed adjacent to the intermediate shaft portion 117 on the side opposite to the first small diameter shaft portion 116. The first small-diameter shaft portion 116 adjacent to the large-diameter shaft portion 37
It has a shape having a second small-diameter shaft portion 118 having the same diameter as.

The plunger 13 is configured such that the first small-diameter shaft portion 116 is
3, the guide member 42 of the large-diameter shaft portion 37 is disposed with the intermediate shaft portion 117 disposed inside the intermediate diameter hole portion 104 and the second small diameter shaft portion 118 disposed inside the second small diameter hole portion 105. The guide shaft 39 is slidably fitted inside the large-diameter hole 16 and the guide shaft 39 is slidably fitted in the guide hole 34 of the outer yoke 33, so that the cylinder 12 can be reciprocated without any misalignment. Will be inserted as possible.

The second small diameter shaft portion 118 of the plunger 13 is slidably fitted to the second small diameter hole portion 105 from the opening of the communication passage 20 to the intermediate small hole portion 104 in the second small diameter hole portion 105. A ring-shaped seal member 120 for closing the gap between the ring-shaped sealing member 120 and the sealing member 120 is fixed.

A ring-shaped first cup seal 121 for opening and closing a gap between the first small-diameter hole portion 103 of the cylinder hole 15 and the first small-diameter shaft portion 116 of the plunger 13 is fixed. 121 is the first small diameter hole 1
03 is slidable. Although not shown, the first cup seal 121 extends from the inner peripheral side of the base to one side in the axial direction and is fixed to the first small-diameter shaft 116 as in the second embodiment. The support member has a U-shaped cross section having an annular support portion and an annular opening and closing portion extending from the outer peripheral side of the base portion to the same side as the support portion in the axial direction.

The first cup seal 121, a part of the plunger 13 protruding from the first cup seal 121, a part on the bottom side of the cylinder hole 15, and the first discharge side check valve 109. A first liquid chamber 125 is defined.

The first cup seal 121 is connected to the first liquid chamber 12
On the 5 side, the support section and the opening / closing section side are arranged,
When the pressure on the first liquid chamber 125 side is higher than the pressure on the introduction passage 18 side, the opening / closing portion is pressed against the cylinder hole 15 to be in a sealed state, and the pressure on the introduction passage 18 side is reduced.
When the pressure is higher than the pressure on the side, the opening / closing portion is separated from the cylinder hole 15 to be in an open state. As a result, the first cup seal 12
Reference numeral 1 denotes an introduction-side check valve that allows the flow of the liquid from the introduction passage 18 toward the first liquid chamber 125 and prevents the flow of the liquid in the opposite direction.

A ring-shaped second cup seal 127 for opening and closing the gap between the intermediate hole portion 104 of the cylinder hole 15 and the intermediate shaft portion 117 of the plunger 13 is fixed.
The second cup seal 127 is slidable with respect to the intermediate diameter hole 104. This second cup seal 12
Although not shown in the drawing, an annular base 7 and an annular support that extends from the inner peripheral side of the base to one side in the axial direction and are fixed to the intermediate shaft 117 are also omitted from the drawing. , And has a U-shaped cross section having a support portion in the axial direction from the outer peripheral side of the base portion and an annular opening / closing portion extending to the same side.

The second cup seal 127, the seal member 120, a part of the plunger 13 located between the second cup seal 127 and the seal member 120, a part of the cylinder hole 15, A second liquid chamber 131 is defined by a part of the discharge passage 107 on the side of the cylinder hole 15 and the second discharge-side check valve 110.

The second cup seal 127 has a support portion and an opening / closing portion disposed on the second liquid chamber 131 side, and the pressure on the second liquid chamber 131 side is higher than the pressure on the introduction passage 18 side. In this case, the opening and closing portion is pressed against the cylinder hole 15 to be in a sealed state, and when the pressure on the introduction passage 18 side is higher than the pressure on the second liquid chamber 131 side, the opening and closing portion is closed by the cylinder hole 1.
5 and open. As a result, the second cup seal 127 forms an introduction-side check valve that allows the flow of the liquid from the introduction passage 18 toward the second liquid chamber 131 and prevents the flow of the liquid in the opposite direction. Here, the introduction passage 18 is
Always the first cup seal 121 and the second cup seal 127
The position is set so as to be located between.

As described above, the first liquid chamber 125 and the second liquid chamber 131 are arranged in parallel along the reciprocating direction of the plunger 13. Here, the first liquid chamber 125
In the second liquid chamber 1, the volume increases due to the one-way movement of the plunger 13 and decreases due to the reverse movement.
31 is such that the volume is reduced by the one-way movement of the plunger 13 and the volume is increased by the reverse movement, and the first liquid chamber 125 further includes a first cup seal 121 as an introduction-side check valve. The first discharge-side check valve 109,
In the second liquid chamber 131, a second cup seal 127 as an introduction-side check valve and a second discharge-side check valve 110 are respectively provided. Here, the diameter φA of the first small diameter hole 103 of the cylinder hole 15 and the diameter φB of the intermediate diameter hole 104
And the diameter φC of the second small-diameter hole portion 105 is φA ²
= ΦB ² −φC ² .

In the third embodiment, a short-circuit ring 133 is fixed to the outer peripheral surface of the magnet 54 of the voice coil motor 14. This short-circuit ring 133
Is made of a copper plate, and is attached so as to surround the outer periphery of the magnet 54 seamlessly. The short-circuit ring 133 constitutes a one-turn transformer with respect to the VCM coil 56. When a voltage is applied to the VCM coil 56, a large current flows in the short-circuit ring 133, and the current rise characteristic of the VCM coil 56 is improved. I do.

In the plunger pump 11 of the third embodiment having such a structure, the introduction passage 18 communicates with the liquid supply source side, that is, the reservoir tank 81, and the first discharge passage 106 communicates with the liquid supply destination side, that is, the caliper 82. At the same time, when the plunger 13 is reciprocated by the voice coil motor 14, the plunger 13 moves in one direction (rightward in FIG. 8), so that the volume in the first liquid chamber 125 is increased and the first discharge side non-return is stopped. While the valve 109 remains closed, the first cup seal 121 is opened and the liquid is introduced from the reservoir tank 81 into the first liquid chamber 125, and at the same time, the second liquid chamber 13 is opened.
1, the second discharge-side check valve 110 is opened while the second cup seal 127 remains closed, and the pressure liquid is discharged from the second liquid chamber 131 toward the caliper 82.

The subsequent movement of the plunger 13 in the reverse direction (left direction in FIG. 8) reduces the volume in the first liquid chamber 125 and keeps the first cup seal 121 closed so that the first discharge side check valve is closed. At the same time as the pressure liquid is discharged from the first liquid chamber 125 to the caliper 82 by opening the
The volume inside 31 increases, and the second cup seal 127 is opened while the second discharge-side check valve 110 is closed, and the liquid is introduced into the second liquid chamber 131. By repeating such a reciprocating motion, the pressure liquid is discharged to the caliper 82.

As described above, while the stroke position of the plunger 13 is detected by the stroke sensor 66, the drive circuit 7
3 is a voice coil motor 1 according to the stroke position.
When the voice coil motor 14 reciprocates the plunger 13 by magnetic force by reversing the direction of the current flowing through the plunger 4, the plunger 13 increases the volume of the first liquid chamber 125 in the forward direction, The volume of the liquid chamber 131 is reduced, the volume of the first liquid chamber 125 is reduced by the backward movement, and the volume of the second liquid chamber 131 is increased. As a result, the pressurized liquid is discharged twice in one reciprocation of the plunger 13. Discharge can be performed toward the caliper 82. That is, the plunger 13 operates as a pump in both reciprocating directions.

Moreover, the first small-diameter hole portion 1 of the cylinder hole 15
03, the diameter φB of the intermediate-diameter hole 104, and the diameter φC of the second small-diameter hole 105 are: φA ² = φB ²
−φC ² , whereby the plunger 13
In other words, when a current having the same current value is caused to flow through the VCM coil 56 under the reverse control, the same discharge pressure is generated from the first liquid chamber 125 and the second liquid chamber 131. Therefore, the pressure rising speed can be increased and the pressure pulsation can be reduced.

Since the short-circuit ring 133 is provided on the outer peripheral surface of the magnet 54 of the voice coil motor 14, when the voltage is applied to the VCM coil 56, the short-circuit ring 1
A large current flows through the inside 33, and the current rising characteristic of the VCM coil 56 can be improved to improve the reciprocating operation speed.

[0075]

As described in detail above, claim 1 of the present invention
According to the plunger pump described above, while the stroke detecting means detects the stroke position of the plunger, the switch means reversely controls the direction of the current flowing through the voice coil motor in accordance with the stroke position. Is reciprocated by magnetic force. Thus, while the thrust is proportional to the current,
The plunger is reciprocated with a voice coil motor that can keep the thrust in the stroke constant and can respond faster.
The volume of the liquid chamber is increased or decreased by the reciprocating motion of the plunger, and the liquid introduced into the liquid chamber through the introduction-side check valve is discharged through the discharge-side check valve. Therefore, it is possible to obtain a necessary pressure only when necessary, with a simple configuration. Further, since there is no need to generate a pressure much higher than the pressure normally used, energy consumption can be reduced.

According to the plunger pump according to the second aspect of the present invention, while the stroke detecting means detects the stroke position of the plunger, the switch means reversely controls the direction of the current flowing through the voice coil motor according to the stroke position. When the voice coil motor reciprocates the plunger with magnetic force, the plunger increases the volume of the first liquid chamber and decreases the volume of the second liquid chamber in one-way movement. Reduces the volume of the first liquid chamber and increases the volume of the second liquid chamber. As a result, the pressurized liquid can be discharged twice in one reciprocation of the plunger. Therefore, the pressure rising speed can be increased and the pressure pulsation can be reduced.

According to the brake device of the third aspect of the present invention, when the operation amount of the brake pedal is detected by the operation amount detection means, the control means controls the plunger of the voice coil motor by magnetic force based on the detection result. The plunger is reciprocated to increase or decrease the volume of the liquid chamber by reciprocating the plunger, and the liquid introduced into the liquid chamber via the introduction-side check valve is discharged through the discharge-side check valve to generate braking force. Introduce hydraulic pressure to In this way, the thrust is proportional to the current, the thrust within the stroke can be made constant, and the plunger is reciprocated by the voice coil motor that can respond at a high speed, and the volume of the liquid chamber is increased or decreased by the reciprocation of the plunger. Since a plunger pump for discharging the liquid introduced into the liquid chamber through the introduction-side check valve through the discharge-side check valve is used, an accumulator, a relief valve, a pressure-intensifying valve, and a pressure sensor are not required. . Therefore, it is possible to obtain a necessary pressure only when necessary, with a simple configuration. Further, since there is no need to generate a pressure much higher than the pressure normally used, energy consumption can be reduced.

According to the brake device of the fourth aspect of the present invention, the current flows to the voice coil motor only when the target hydraulic pressure based on the detection result of the operation amount detecting means is higher than the hydraulic pressure of the braking force generating means. And energy consumption can be further reduced.

[Brief description of the drawings]

FIG. 1 is a side sectional view showing a plunger pump according to a first embodiment of the present invention.

FIG. 2 shows a stroke sensor of the plunger pump according to the first embodiment of the present invention, wherein (a) is a side view,
(B) is a figure which shows the relationship between a stroke and a voltage.

FIG. 3 is a configuration diagram showing a brake device using the plunger pump according to the first embodiment of the present invention.

FIG. 4 is a circuit diagram showing a drive circuit of a brake device using the plunger pump according to the first embodiment of the present invention.

FIG. 5 is a timing chart showing signals of a drive circuit of a brake device using the plunger pump according to the first embodiment of the present invention.

FIG. 6 is a side sectional view showing a plunger pump according to a second embodiment of the present invention.

FIG. 7 is a side sectional view showing the vicinity of a cup seal of a plunger pump according to a second embodiment of the present invention.

FIG. 8 is a side sectional view showing a plunger pump according to a third embodiment of the present invention.

FIG. 9 is a configuration diagram showing a conventional brake device.

[Explanation of symbols]

Reference Signs List 11 plunger pump 12 cylinder 13 plunger 14 voice coil motor 23 introduction check valve 24 discharge check valve 45 liquid chamber 66 stroke sensor 73 drive circuit (control means) 75 brake device 76 brake pedal 77 pedal force sensor (operation amount detection means) ) 82 Caliper (braking force generating means) 96 Switch circuit (switch means) 101, 121, 127 Cup seal (introduction check valve) 125 First liquid chamber 131 Second liquid chamber

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H02P 7/00 101 H02K 33/18 B 5H607 // H02K 33/18 F04B 17/04 5H633 F Term (Reference) 3D049 BB17 BB42 CC02 HH12 HH47 HH48 HH53 RR05 3H045 AA03 AA08 AA12 AA32. BB06 BB08 EE17 FA03 FA23 5H607 BB01 BB11 BB14 BB21 CC01 DD17 EE08 FF06 5H633 BB02 GG03 GG06 GG09 GG17 GG23 HH02 JA02 JA08 JB06

Claims (4)

[Claims] 1. A cylinder, a plunger reciprocally inserted into the cylinder, a liquid chamber defined by the plunger and the cylinder, the volume of which increases and decreases by reciprocation of the plunger; In a plunger pump having an introduction-side check valve that allows only liquid flow and a discharge-side check valve that allows only liquid flow from the liquid chamber, a voice coil motor that drives the plunger with magnetic force, A plunger pump comprising: stroke detection means for detecting a stroke position of the plunger; and switch means for inverting and controlling the direction of a current flowing through the voice coil motor in accordance with a detection result of the stroke detection means. . 2. The liquid chamber has a first liquid chamber whose volume is increased by one-way movement of the plunger and whose volume is decreased by a reverse movement, and a first liquid chamber whose volume is reduced by the one-way movement of the plunger. A second liquid chamber whose volume is increased by movement is provided, and the first liquid chamber and the second liquid chamber are provided with the introduction-side check valve and the discharge-side check valve, respectively. The plunger pump according to 1. 3. A plunger pump according to claim 1 or 2, an operation amount detecting means for detecting an operation amount of a brake pedal, and a braking force generating means for generating a braking force by a hydraulic pressure generated by the plunger pump. And a control unit for controlling the plunger pump based on a detection result of the operation amount detection unit. 4. The control device according to claim 1, wherein the control unit supplies a current to the voice coil motor only when a target hydraulic pressure based on a detection result of the operation amount detecting unit is higher than a hydraulic pressure of the braking force generating unit. Item 4. The brake device according to item 3.