JP2014148932A - Engine work machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an engine work machine capable of stably starting an engine even when a carburetor goes wrong.SOLUTION: An engine work machine which drives a work machine with an engine comprises: a cell motor which starts the engine by being driven with electric power supplied from a battery; and start control means which controls electric power supply to the cell motor. The start control means starts the engine by driving the cell motor at a first rotation speed Nand, when determining that the engine is not started after a lapse of predetermined time, driving the cell motor at a second rotation speed Nfaster than the first rotation speed.

Description

  The present invention relates to an engine working machine such as a chain saw or a brush cutter, and more particularly to an engine working machine that starts by driving a cell motor using a battery.

  In small working machines such as brush cutters and chain saws, small engines are widely used as power sources. FIG. 7 is an external view of a brush cutter as an example of an engine working machine. As shown in FIG. 7, an engine work machine 501 equipped with a small two-cycle engine passes a drive shaft (not shown) through a pipe-shaped main pipe 5, and this drive shaft is connected to an engine provided at one end of the main pipe 5. The rotary blade 6 provided at the other end of the main pipe 5 is rotated. In the vicinity of the rotary blade 6, a scattering protection cover 6 a for preventing scattering of the cut grass is provided. The engine working machine 1 is carried by a shoulder belt (not shown) or the like, and a handle 4 having a substantially U shape in front view for operation by an operator is attached to the vicinity of the central portion of the main pipe 5. The rotation speed of the engine working machine 1 is controlled by an operator by a throttle lever 7 attached in the vicinity of the grip portion 3. The operation of the throttle lever 7 is transmitted to the engine carburetor by the wire 18.

  An engine such as that used in the engine work machine 501 is small and light and can obtain a large output, and can supply a fuel for a long time. A manual starter is used to start the engine, and various ideas have been proposed to improve startability. For example, Patent Document 1 proposes a small engine working machine that includes a cell motor and has improved startability by increasing the fuel concentration of the air-fuel mixture to the engine.

Japanese Utility Model Publication No. 63-164549

  Conventionally, a mixed oil in which gasoline and oil are mixed is used as a fuel for a two-cycle engine. If this mixed oil is left in the engine tool for a long time, the gasoline may vaporize and the mixing ratio with the oil may change. Moreover, when the oil in mixed oil deteriorates, there exists a possibility that a viscosity may become high and it may change to gum shape and the inside of a vaporizer may be clogged. For this reason, when storing engine tools for a long time, the fuel in the carburetor must be removed by emptying the engine when the engine is stopped.

  The present invention has been made in view of the above background, and an object of the present invention is to provide an engine working machine that can easily start an engine even if a carburetor is malfunctioning.

  Another object of the present invention is to provide an engine work machine in which startability is further improved by rotating the cell motor at a high speed in the boost mode when the cell motor is not started by a normal engine start operation. .

  Still another object of the present invention is to provide an engine working machine that can effectively eliminate clogging of a carburetor.

The characteristics of representative ones of the inventions disclosed in the present application will be described as follows.
According to one aspect of the present invention, an engine having a cylinder in which a piston can reciprocate, a crankcase that holds the cylinder and forms a crank chamber, and a cell motor that moves the piston by electric power supplied from a battery is used. In the engine working machine that drives the work equipment, there is provided start control means for controlling power supply to the cell motor. The start control means drives the cell motor at the first rotational speed, and a predetermined time has elapsed since the start of driving the cell motor. Even when the engine is not started, the cell motor is driven at a second rotational speed higher than the first rotational speed.

  According to another feature of the invention, the start control means drives the cell motor with the first effective voltage at the first rotational speed, and the second higher than the first effective voltage at the second rotational speed. The cell motor is driven with an effective voltage of. This is because the switching element is provided in series in the power supply circuit from the battery to the cell motor, and the start control means performs PWM (Pulse Width Modulation) control of the switching element, and is applied to the cell motor by changing the duty ratio of the PWM control. Adjust the effective voltage. The start control means preferably determines the duty ratio at the first and second rotational speeds based on the voltage measurement result of the battery. The battery is preferably a lithium ion secondary battery, but any other primary battery or secondary battery can be used.

  According to still another aspect of the present invention, a centrifugal clutch that transmits the rotational force of the engine to the work equipment is provided, and the second engine speed when the cell motor is driven with the second effective voltage is the value of the centrifugal clutch. The number of rotations was less than the connection speed. The first engine speed when the cell motor is driven with the first effective voltage is less than half of the connection speed of the centrifugal clutch, and the second engine speed is more than half of the connection speed of the centrifugal clutch. It is preferable. The start control means stops the rotation of the cell motor when the engine does not start even if the engine rotates at the second rotation speed for a predetermined time. The start control means determines whether or not to shift from the first rotation speed to the second rotation speed and / or the timing to shift.

According to the first aspect of the present invention, when the cell motor is driven at the first rotational speed and the engine is not started even after a predetermined time has elapsed since the start of the driving of the cell motor, the cell motor is driven at a speed higher than the first rotational speed. Since the carburetor is clogged and it becomes difficult to start the engine because it is driven at a high second rotational speed, the negative pressure in the cylinder can be reduced by making the rotational speed of the cell motor higher than usual. Clogging in the vaporizer can be released.
According to the invention of claim 2, the cell motor is driven with the first effective voltage at the first rotational speed, and the cell motor is driven with the second effective voltage higher than the first effective voltage at the second rotational speed. Since it is driven, it is possible to control the number of revolutions easily by simply changing the voltage to the cell motor.
According to the invention of claim 3, since the effective voltage applied to the cell motor is adjusted by performing PWM control of the switching element and changing the duty ratio of the PWM control, it is necessary to use an ON / OFF switch to the cell motor. In addition, it is possible to realize an engine work machine that greatly reduces the cost increase. Further, the rotation speed of the motor can be easily adjusted by the start control means using a microcomputer.
According to the invention of claim 4, since the start control means determines the duty ratio at the first and second rotational speeds based on the voltage measurement result of the battery, it is possible to use batteries having different voltage specifications. The cell motor can be driven stably without being affected by the remaining amount.
According to the invention of claim 5, since the second engine speed when the cell motor is driven with the second effective voltage is equal to or lower than the connection speed of the centrifugal clutch, the rotation speed of the cell motor is increased. In addition, it is possible to prevent the centrifugal clutch from being connected, to prevent malfunction during starting, and to realize a highly safe engine working machine.
According to the sixth aspect of the present invention, since the first engine speed when the cell motor is driven with the first effective voltage is less than half of the connected speed of the centrifugal clutch, a large safety margin is normally obtained. The engine can be started with this secured. Further, since the second engine speed is not less than half of the connection speed of the centrifugal clutch but less than the connection speed, the engine can be started with a safety margin secured.
According to the invention of claim 7, since the start control means stops the rotation of the cell motor when the engine does not start even if the engine rotates at the second rotation speed for a predetermined time, it effectively prevents the battery from being overdischarged. be able to.
According to the invention of claim 8, since the start control means determines whether or not to shift from the first rotation speed to the second rotation speed and / or the timing to shift, the start control means determines the boost mode. It is possible to determine whether or not (the mode in which the cell motor is driven at a high rotation) is necessary, and it is possible to perform start-up control according to the settings from the operator and the surrounding conditions.

  The above and other objects and novel features of the present invention will become apparent from the following description and drawings.

It is a longitudinal cross-sectional view which shows the internal structure of the engine working machine which concerns on the Example of this invention. It is a rear view of the engine working machine which concerns on the Example of this invention. It is a circuit diagram of the engine working machine which concerns on the Example of this invention. It is a flowchart which shows the starting control of the engine working machine which concerns on the Example of this invention using FIG. It is a graph which shows the relationship of the time at the time of the normal engine starting based on the Example of this invention, a cell motor, and an engine speed. It is a graph which shows the relationship between the time in engine starting at the time of the boost mode action | operation which concerns on the Example of this invention, a cell motor, and an engine speed. It is an external view which shows the whole engine working machine shape. It is a perspective view which shows an example (brusher) of the conventional engine working machine.

  Embodiments of the present invention will be described below with reference to the drawings. In the following drawings, the same portions are denoted by the same reference numerals, and repeated description is omitted. Further, in this specification, description will be made assuming that the front, rear, left, right, and up and down directions are directions shown in the drawing.

  FIG. 1 is a longitudinal sectional view showing the internal structure of the engine working machine 1 according to this embodiment. The engine 10 is a two-cycle small engine, the crankshaft 13 is arranged coaxially with the main pipe 5 (see FIG. 7), the cylinder 11 is arranged so as to extend from the crankcase 14 substantially upward in the vertical direction, The piston 12 reciprocates in the cylinder 11 in the vertical direction. One end of a drive shaft (not shown) is connected to the front side (output side) of the crankshaft 13 via a clutch shaft 32 via a centrifugal clutch 29. The magnet rotor 22 to which the centrifugal clutch 29 is attached is integrally formed with engine cooling fins. The centrifugal clutch 29 is a known centrifugal clutch in which the oscillator 30a is connected to the clutch drum 30b by centrifugal force when the rotation speed of the crankshaft 13 becomes equal to or higher than a certain value. The clutch shaft 32 is rotatably held by a bearing 33 held by a housing 34. An ignition coil 23 is provided on the outer peripheral portion of the magnet rotor 22, here in the upper portion. The high-voltage current generated by the ignition coil 23 is transmitted to the spark plug 25 through the ignition cord 24 and the plug cap 25a. A fuel tank 27 is provided below the crankcase 14 of the engine 10. The fuel tank 27 contains a mixed oil of gasoline and oil for two cycles, and is sent to a vaporizer 35 (see FIG. 2) described later.

  One end of a drive shaft (not shown) is connected to the front side (output side) of the crankshaft 13 via a clutch shaft 32 via a centrifugal clutch 29. The magnet rotor 22 to which the centrifugal clutch 29 is attached is integrally formed with engine cooling fins. A decompression mechanism (hereinafter referred to as decompression) 31 is provided at a position adjacent to the combustion chamber of the cylinder 11 (the side surface of the cylinder 11 in FIG. 1). The decompression 31 is a mechanism for releasing part of the pressure in the combustion chamber when starting the engine 10 to facilitate the compression work by the piston 12 and making the engine 10 easier to start. In this embodiment, a part of the pressure in the cylinder 11 can be released by pushing in the operation portion (operation button) of the decompression 31 (moving the operation button from the rear to the front side). When the first combustion (first explosion) immediately after the rotation of the crankshaft 13 occurs, the decompression 31 automatically returns due to the pressure fluctuation.

  As a starting device for the engine 10 according to the present embodiment, two systems of a cell motor 106 and a recoil starter 40 are provided. The cell motor 106 is rotated by the electric power supplied via the connection line 52, and the gear 49 is rotated by the rotation of the pinion 57 provided on the rotating shaft 106a. The gear 49 is rotatably held with respect to the crankshaft 13 by the bearing 48. When the gear 49 rotates at a high speed, the one-way clutch 50 attached to a part of the gear 49 protrudes radially outward by centrifugal force. The crankshaft 13 is rotated by rotating the first drum 51 in close contact with the first drum 51. The recoil starter 40 rotates the starter rope 42 wound around the reel 41 at a high speed with a starter handle 36 (see FIG. 2 described later), so that the one-way clutch 46 protrudes radially outward by centrifugal force, and the second drum 47 The second drum 47 is rotated closely. Since the second drum 47 is fixed to the crankshaft 13, when the second drum 47 rotates, the crankshaft 13 also rotates so that the engine can be started. The released starter rope 42 is wound around the reel 41 by the restoring force of the spiral spring 43.

  The battery storage unit 39 is provided separately from, for example, the two grip units 3 (see FIG. 7) held by the operator, and is detachably provided on the handle 4, for example. In the present embodiment, the battery storage unit 39 is shaped to match the pack-type battery 80, but the shape of the battery storage unit 39 can be arbitrarily set according to the shape of the battery to be mounted. For example, you may comprise so that the lithium ion battery pack for several types of electric tools from which voltage differs, a dry cell, etc. can be mounted | worn. When starting the engine 10, the power switch 110 is turned on and then the cell switch 125 is pushed. When stopping the engine 10 during operation, a stop switch (kill switch) (not shown) provided on the main body side of the engine 10 is pressed to stop the supply of high-voltage current to the spark plug 25. The stop switch is provided at an arbitrary position (for example, the upper cover 2) on the engine 10 side, but may be configured to be provided in the battery storage unit 39. A battery 80 that is substantially cylindrical and can be attached and detached is housed inside the battery housing 39. The battery 80 has a substantially cylindrical shape and is configured in a so-called cassette type so that it can be attached to and detached from the battery storage unit 39. The battery 80 has two hooking portions 81 a formed therein, and holds the battery 80 by engaging with a recess (not shown) formed on the inner wall of the battery storage portion 39. In order to remove the battery 80, the battery 80 is pulled out from the battery storage unit 39 while pressing the release button 81.

  For example, four 14500-size lithium ion battery cells (not shown) are accommodated in the battery 80. The shape of the rear end portion (lower side in the figure) of the battery storage portion 39 is formed so as to cover the opening portion 39a at the lower end. A start control circuit board 85 is provided at the other end of the mounting space of the battery 80 following the opening 39a, and a plurality of terminals 84 are provided so as to extend from the start control circuit board 85 toward the opening 39a. The start control circuit board 85 is a board on which a control circuit 102 described later in FIG. 3 is mounted. A plurality of terminals 83 are provided at the front end portion (upper side in the drawing) of the battery 80, and the terminal 83 comes into contact with the terminal 84 formed on the battery housing portion 39 side by mounting the battery 80 on the battery housing portion 39. Therefore, the power of the battery 80 is supplied to the control circuit 102 described later.

  FIG. 2 is a rear view of the engine working machine 1 according to the embodiment of the present invention. A carburetor 35 is provided on the left side of the engine 10 via an insulator 19 that connects an intake port of the engine 10, and an air cleaner cover 26 that forms a storage space for an air cleaner that filters inhaled air on the left side of the carburetor 35. Is provided. A muffler 16 is provided on the right side of the engine 10, and an exhaust port 16 a serving as an exhaust gas outlet is provided on the rear surface side of the muffler 16. The muffler 16 is covered with a resin muffler cover 8 to prevent the operator from touching it directly. The upper part of the engine 10 is covered by the upper cover 2. A recoil starter 40 (see FIG. 1) is provided coaxially with the crankshaft 13 and at the rear end thereof, and the recoil starter 40 is covered with a starter case 9. In the engine working machine 1 of the present embodiment, not only the recoil starter 40 but also the cell motor 106 (see FIG. 1) is provided, so that the shape of the starter case 9 viewed from the rear is a portion covering the recoil starter 40 and a portion covering the cell motor 106. It is made into the shape of a saddle like that was connected. A starter handle 36 is provided on the left side of the starter case 9. A fuel tank 27 is provided below the crankcase 14. The fuel tank 27 is a container formed of a translucent polymer resin, and a mixed fuel in which gasoline and a predetermined ratio of oil are mixed can be put in by removing the cap 28 attached to the opening.

  FIG. 3 is a circuit diagram of the engine working machine 1 according to the present embodiment. The engine working machine 1 is provided with a starting device using a cell motor 106, and the starting device is electronically controlled by a control circuit 102 (starting control means). The control circuit 102 includes three FETs 107, 117, 121, resistors 108, 109, 111, 112, 124, a power switch 110, a cell switch 125, capacitors 113, 114, 115, a regulator 116, and a microcomputer. 118 is comprised.

  The microcomputer 118 is driven by a constant voltage supplied by the regulator 116, and a signal indicating the voltage of the battery 80 by the resistors 111 and 112 is input to a plurality of A / D conversion ports. Further, an output signal of the rotation detection coil 105 is input from the engine 10 side. The rotational speed (rotational speed) of the engine 10 is detected by converting the magnetic flux from the magnet attached to the engine 10 into a voltage by the rotation detection coil 105 and inputting it to the microcomputer 118. Further, the microcomputer 118 controls the conduction or blocking between the source and the drain of the FETs 117 and 121 by transmitting the gate signals of the FETs 117 and 121.

  The FET 121 serves as a semiconductor switch for driving the cell motor 106, and the source and drain of the FET 121 are brought into conduction by a command from the microcomputer 118 (supply of a gate signal), and a current flows through the cell motor 106. In addition, the microcomputer 118 performs pulse width modulation (PWM) control on the conduction of the FET 121 to lower the power supplied from the battery 80 to the cell motor 106 and adjust the effective voltage. The FET 121 may be composed of other semiconductor switching elements, and may be composed of an insulated gate bipolar transistor (Insulated Gate Bipolar Transistor), other transistors, or the like.

  Next, a method for driving the cell motor 106 in the engine working machine 1 according to the embodiment of the present invention will be described with reference to FIG. First, before describing the driving method of the cell motor 106 according to the present embodiment, the driving method of the cell motor in the conventional engine working machine will be described. FIG. 8 is a graph showing the relationship between the time when the conventional engine is started and the rotational speeds of the cell motor and the engine. The horizontal axis represents the passage of time (unit: second), and the vertical axis represents the rotational speed (unit: rpm) of the cell motor and engine. A dotted line indicates the rotational speed 181 of the cell motor, and a solid line indicates the rotational speed 182 of the engine. It should be noted that although the portions shown in parallel without the positions of the dotted line and the solid line being overlapped are actually overlapped, they are shifted in order to make them easier to see. The cell motor rotation speed 181 here is not the rotation speed of the rotation shaft 106a of the cell motor 106 but the rotation speed of the gear 49 portion of FIG. 1 in order to simplify the comparison with the rotation speed of the crankshaft. Please note that it is shown.

First operator at time t ₁ is the starter motor 106 by pressing the cell switch is initiated the rotation of the engine 10 to start. The starter motor 106 a predetermined voltage is supplied, to accelerate after the start rotating gear 49 is at a predetermined rotational speed N _1. At this time, when the gear 49 rotates at a high speed, the one-way clutch 50 attached to a part of the gear 49 protrudes radially outward by centrifugal force, and rotates the first drum 51 in close contact with the first drum 51. As a result, the crankshaft 13 rotates, and the rotational speed of the cell motor 106 and the rotational speed of the gear 49 are substantially synchronized. When the engine 10 is started at time _{t 2, the} rotational speed 182 of the engine 10 reaches the idling speed _{N I} at time _{t 3} to rise. Starter motor 106, the rotational speed of the gear 49 is stopped after rotating at a constant rotational speed in a state that does not work with the rotation speed of the engine 10 to the time t _3. Strictly speaking, when the engine 10 is started at the time t ₂ , the cell motor 106 is in a no-load operation, so the rotation speed often increases. However, in the description of this embodiment, the load fluctuation is described in order to explain the basic principle. It explains without considering the rotation fluctuation by. Timing of the starter motor 106 is turned OFF, the operator intended to determine by checking the engine sound, the rotation of the starter motor 106 by the operator at around the time t ₃ in the example of FIG. 8 releases the cell switch 125 Stop.

Returning to FIG. 4, the driving method of the cell motor 106 in the engine working machine 1 of the present embodiment will be described. Starter motor 106 is activated by the operator pushes the cell switch 125 at time _{t 1.} Microcomputer 118 drives the starter motor 106 at a first effective voltage (effective power), the engine 10 starts to rotate, the gear 49 is rotated at a predetermined rotational speed N _1. At this time, the rotational speed of the rotational speed and the gear 49 of the starter motor 106 are synchronized substantially the same, control proceeds engine 10 until the time t ₂ to start is the same as the control of the conventional example shown in FIG. In the present embodiment, when the engine 10 does not start between times t _{1 and} t ₂ , the microcomputer 118 increases the rotational speed 141 of the cell motor 106. At this time, the microcomputer 118 drives the cell motor 106 with the second effective voltage higher than the first effective voltage, and increases the rotational speed 142 of the gear 49 from N ₁ to N ₂ . As the rotational speed N ₂ is lower rotational speed than the centrifugal clutch 29 rpm rocker 30a is connected to the clutch drum 30b (see FIG. 1) (connection speed), the rotational speed N ₂ of the crank shaft 13 It is important to prevent power from being transmitted to the rotary blade 6 side (working equipment side) even if it is rotated at the position.

When the engine 10 is started at time _{t 3} the rotational speed 141 of the gear 49 continues rotating at _{N 2,} rotational speed 142 of the engine 10 reaches the idling speed _{N I} at time _{t 4} to rise. At this time, since the rotation speed 142 of the engine 10 exceeds the cutoff rotational speed N _U connecting the clutch for the starter motor, by the one-way clutch 50 attached to the first drum 51 is moved to the outer peripheral side by centrifugal force of the gear 49 Since the engagement state with the engagement piece portion is released, the output transmission of the cell motor 106, that is, the output transmission of the rotational force of the gear 49 to the crankshaft 13 is cut off. Rotation speed 141 of the gear 49 is stopped by the control of the microcomputer 118 after rotating at a constant rotational speed to the vicinity of the time t ₄ is not linked with the rotation speed 142 of the engine 10. Here, the time and the starter motor 106 to the rotation speed 141 of the engine 20 reaches the idling speed N _I but the timing is not required to match that to OFF, rotation of the starter motor 106 in order to suppress consumption of the battery 80 to accelerate It is desirable to control to stop. The first engine rotational speed N ₁ is set to a rotational speed that is less than or equal to half the connection rotational speed of the centrifugal clutch 29, and the second engine rotational speed N ₂ is set to a rotational speed that is greater than or equal to half the connected rotational speed of the centrifugal clutch 29. It is preferable.

  Next, a series of operations of the engine work machine 1 of the present invention will be described with reference to the flowchart of FIG. First, when the power switch 110 for the starter is turned on (step 201), the gate voltage of the FET 107 is applied by the resistors 108 and 109, the FET 107 is turned on (step 202), and the voltage is applied to the regulator 116. Supplied. The regulator 116 is a constant voltage source and supplies a constant voltage to the microcomputer 118 and the like. Capacitors 114 and 115 are provided to stabilize the output voltage of the regulator 116.

  When a predetermined voltage is input to the power supply terminal of the microcomputer 118, the microcomputer 118 is activated (step 203). Next, the microcomputer 118 supplies the gate signal to turn on the FET 117 (conduction between the source and drain), and keeps the FET 107 on even after the power switch 110 is opened (step 204). ).

  Next, the microcomputer 118 measures the battery voltage (step 205). In the circuit diagram shown in FIG. 3, the battery 80 has a rated voltage of 14.4 V in which four lithium ion batteries with a rated voltage of 3.6 V are connected in series, but is not limited thereto, and has a voltage higher than the rated voltage of the cell motor 106. Various batteries, for example, battery packs for electric tools using lithium ion battery cells of about 14.4 V to 36 V, or battery devices using other primary batteries and secondary batteries for engines can be used. The battery voltage is measured by smoothing the voltage divided by the resistors 111 and 112 by the capacitor 113 and inputting it to the A / D conversion input terminal of the microcomputer 118.

Next, in step 206, the microcomputer 118 determines the PWM control ON duty ratio of the gate signal input to the FET 121 in order to control the effective voltage applied to the cell motor 106. The PWM control ON duty ratio is determined by the following equation.
PWM control ON duty ratio = target motor voltage / battery voltage Here, the target motor voltage is a voltage value to be applied to the cell motor in the initial stage, and is applied to the cell motor in the boost mode performed when the engine is not started for a predetermined time. There are two types of voltage values. Incidentally, the target motor voltage in the boost mode needs to be set higher than the initial target motor voltage. As a specific example, if the initial target motor voltage is set to 8.0 V when the battery voltage is 14.4 V, and the target motor voltage is set to 12.0 V in the boost mode, the PWM control ON duty ratio is 56% and 83% in boost mode.

  Next, in step 207, it is determined whether or not the cell switch 125 has been pressed (turned on). If the cell switch 125 is OFF, the process proceeds to step 208, where the elapsed time from the start of the microcomputer is measured. If the cell switch 125 is not pressed for a predetermined time, the process proceeds to step 216, where the microcomputer 118 turns off the FET 117. Thus, the power supply of the control circuit 102 is shut down by itself, and the start control of the engine 10 is finished. When the cell switch 125 is turned on in step 207, the process proceeds to step 209, and the microcomputer 118 rotates the cell motor 106 by supplying the FET 121 with the gate voltage corresponding to the initial PWM control ON duty ratio calculated in step 206. .

  Next, in step 210, the microcomputer 118 detects whether or not the engine 10 has been started, that is, whether or not the engine 10 is continuously rotating at a rotational speed equal to or greater than a predetermined value. This can be determined based on whether or not the engine rotation signal is periodically detected from the rotation detection coil 105 by the microcomputer 118. If it is determined in step 210 that the engine 10 has been started (step 214), the process proceeds to step 216, where the microcomputer 118 turns off the FET 117, thereby shutting down the power supply of the control circuit 102, and starting the engine 10. End control. If it is determined in step 210 that the engine has not been started, the process proceeds to step 211, where it is determined whether a predetermined time has elapsed since the start of the cell motor. If the predetermined time has not elapsed, the process returns to step 210 and the cell motor is continuously driven. to continue. If the predetermined time has elapsed, the process proceeds to step 212, where the microcomputer 118 rotates the cell motor 106 by supplying the FET 121 with a gate voltage corresponding to the boost mode PWM control ON duty ratio calculated in step 206.

  Next, in step 213, the microcomputer 118 detects again whether or not the engine 10 has been started, that is, whether or not the engine 10 is continuously rotating at a rotational speed equal to or greater than a predetermined value. If it is determined in step 213 that the engine 10 has started, the process proceeds to step 216 (step 214), and the microcomputer 118 shuts down the power supply of the control circuit 102 by turning off the FET 117, thereby controlling the start of the engine 10. Exit.

  If it is determined in step 213 that the engine has not been started, the process proceeds to step 215 to determine whether a predetermined time has elapsed since the start of the cell motor. If the predetermined time has not elapsed, the process returns to step 213 to continue driving the cell motor. to continue. When the predetermined time has elapsed, the process proceeds to step 216, where the microcomputer 118 turns off the FET 117, thereby shutting down the power supply of the control circuit 102 and ending the start control of the engine 10. In the flowchart of FIG. 5, if the engine could not be started due to a single start of the cell motor, the power supply of the control circuit 102 is shut down in steps 214 and 216 to finish the start control. The cell motor 106 may be allowed to restart until a predetermined number of times, or the cell motor may be allowed to start until the voltage of the battery 80 decreases. In step 215, the microcomputer 118 is configured to stop the rotation of the cell motor 106 after a predetermined time has elapsed. However, the rotation of the cell motor 106 is maintained until the operator releases the cell switch 125 (however, an upper limit time can be set). You may comprise so that it may permit.

  As described above, in this embodiment, when the engine is started by the cell motor, if it is determined that the engine has not started even after a lapse of a predetermined time, the cell motor is driven at a higher rotation with a higher effective voltage. The cell motor is driven in the so-called boost mode. For this reason, even if the carburetor is clogged due to long-term storage with the fuel left in place and it becomes difficult to start the engine, by increasing the rotational speed of the cell motor higher than usual, The clogging in the vaporizer can be effectively eliminated by the negative pressure.

Next, a second embodiment of the present invention will be described with reference to FIG. Figure 6 is another method of driving the starter motor 106 in the engine working machine 1 of this embodiment, the engine 10 starter motor 106 is activated by the operator at time t ₁ pushes the cell switch 125 starts to rotate . The control from here to time t2 is the same control as in the first embodiment shown in FIG. If the engine 10 does not start between times t _{1 and} t ₂ , the microcomputer 118 increases the rotational speed 143 of the cell motor 106 to increase the rotational speed 144 of the gear 49 from N ₁ to N ₂ . in 2 of the example it was configured so as to gradually increase toward t ₃ the rotational speed 143 of the starter motor 106 from time t _2.

Rotation speed 143 of the gear 49 when it reaches the _{N 2} at time _{t 3,} and controls to continue rotate at a rotational speed _{N 2.} When the engine 10 is started at time _{t 4,} it reaches the idling speed _{N I} at time _{t 5} rpm 144 of the engine 10 is increased. At this time, the rotation number 142 of the engine 10 is to cross the cutoff rotational speed N _U connecting the clutch for the starter motor, an output transmission from the starter motor 106 to the crank shaft 13 is blocked. Rotation speed 143 of the gear 49 is stopped by the control of the microcomputer 118 after rotating at a constant rotational speed to the vicinity of the time t ₅ is not linked with the rotation speed 144 of the engine 10. By controlling as in the second embodiment, the rotational speed of the cell motor 106 does not increase suddenly when shifting to the boost mode, but gradually increases, so that a sudden change in motor sound can be prevented. .

  As mentioned above, although this invention was demonstrated based on the Example, this invention is not limited to the above-mentioned Example, A various change is possible within the range which does not deviate from the meaning. For example, in the above-described embodiment, the brush cutter is used as an example of the engine working machine. However, other types of engine working machines such as a cutter, a chain saw, a lawn mower, and a cultivator may be used.

DESCRIPTION OF SYMBOLS 1 Engine working machine 2 Upper cover 3 Grip part 4 Handle 5 Main pipe 6 Rotary blade 6a Splash prevention cover 7 Throttle lever 8 Muffler cover 9 Starter case 10 Engine 11 Cylinder 12 Piston 13 Crankshaft 14 Crankcase 16 Muffler 16a Exhaust port 18 Wire 19 Insulator 20 Engine 22 Magnet Rotor 23 Ignition Coil 24 Ignition Cord 25 Spark Plug 25a Plug Cap 26 Air Cleaner Cover 27 Fuel Tank 28 Cap 29 Centrifugal Clutch 30a Oscillator 30b Clutch Drum 31 Decompressor 32 Clutch Shaft 33 Bearing 34 Housing 35 Vaporizer 36 Starter handle 39 Battery storage 39a Opening 40 Recoil starter 41 Reel 42 Tarter rope 43 Spiral spring 46 One-way clutch 47 Second drum 48 Bearing 49 Gear 50 One-way clutch 51 First drum 52 Connection line 57 Pinion 80 Battery 81 Release button 81a Latch part 83 Terminal 84 Terminal 85 Start control circuit board 102 Control circuit 105 Rotation Coil for detection 106 Cell motor 106a Rotating shaft 107, 117, 121 FET
108, 109, 111, 112, 124 Resistor 110 Power switch 113, 114, 115 Capacitor 116 Regulator 118 Microcomputer 125 Cell switch 141, 143, 181 Cell motor speed 142, 144, 182 Engine speed 501 Engine working machine

Claims (8)

A cylinder in which the piston can reciprocate;
A crankcase for holding the cylinder and forming a crank chamber;
In an engine working machine that drives a work device using an engine having a cell motor that moves the piston by electric power supplied from a battery,
A start control means for controlling power supply to the cell motor is provided,
The start control means drives the cell motor at a first rotation speed, and when the engine has not started even after a predetermined time has elapsed since the start of driving the cell motor, the start motor is operated at the first rotation speed. An engine working machine that is driven at a second rotational speed that is faster than the second rotational speed.   The start control means drives the cell motor with a first effective voltage at a first rotation speed, and drives the cell motor with a second effective voltage higher than the first effective voltage at a second rotation speed. The engine working machine according to claim 1, wherein the engine working machine is driven. A switching element is provided in series in the power supply circuit from the battery to the cell motor,
The engine work machine according to claim 2, wherein the start control means performs PWM control of the switching element, and adjusts an effective voltage applied to the cell motor by changing a duty ratio of the PWM control. .   The engine work machine according to claim 3, wherein the start control means determines the duty ratio at the first and second rotational speeds based on a voltage measurement result of the battery. A centrifugal clutch for transmitting the rotational force of the engine to the work equipment;
5. The engine working machine according to claim 4, wherein the second engine rotation speed when the cell motor is driven with the second effective voltage is equal to or less than a connection rotation speed of the centrifugal clutch.   The first engine speed when the cell motor is driven with the first effective voltage is equal to or less than half of the connection speed of the centrifugal clutch, and the second engine speed is the connection speed of the centrifugal clutch. 6. The engine working machine according to claim 5, wherein the working number is half or more of the number.   The engine work according to claim 5 or 6, wherein the start control means stops the rotation of the cell motor when the engine does not start even if the engine rotates at the second rotation speed for a predetermined time. Machine.   The start control means determines whether or not to shift from the first rotation speed to the second rotation speed and / or the timing to shift. The engine work machine as described in the item.

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