FR3086496A1 - CONTROL COMPUTER OF A MOTOR-FAN GROUP OF A MOTOR VEHICLE - Google Patents

Abstract

The invention relates to a control computer (100) of a fan unit (600) of a vehicle, the control computer (100) comprising at least one electronic card (1) comprising an electronic chip (2) and a plurality of transistors (3, 3a, 3b, 3c), the electronic chip (2) being configured to control the plurality of transistors (3, 3a, 3b, 3c), the electronic card (1) comprising at least first connection pads (5) connected to the electronic chip (2), at least second connection pads (6) each connected to a transistors (3, 3a, 3b, 3c) and at least connection tracks (7, 7a, 7b, 7c) connecting the first connection pads (5) to the second connection pads (6). In the control computer (100) according to the invention, a length (200) of the longest connecting track (7, 7a, 7b, 7c) is less than or equal to eleven millimeters.

Description

CONTROL COMPUTER OF A MOTOR-FAN GROUP OF A MOTOR VEHICLE

The invention relates to the field of rotating electrical machines intended for a motor vehicle. It finds a preferred, but not exclusive, application to motor-driven fan groups placed on the front of a vehicle and intended to generate an air flow passing through at least one heat exchanger.

Such motor-ventilator groups in particular comprise a propeller driven in rotation by an electric motor, the operation of which is governed by an electronic control and command unit.

The electronic control and command unit includes in particular a computer configured to establish a set of control information from data received from the vehicle. It also includes a circuit for controlling a plurality of transistors configured to receive a signal representative of all of the control information established by the aforementioned computer and to control, on the basis of this information, the operation of the electric motor.

The technical problem to which the invention proposes to provide a solution is that of the electromagnetic disturbances induced by such a PWM signal on other electronic devices of the vehicle such as, for example, a satellite geolocation system or an audio system of the vehicle.

To address this problem, the subject of the invention is a control computer for a motor-driven fan assembly of a vehicle, the control computer comprising at least one electronic card comprising an electronic chip and a plurality of transistors, the chip being configured to control the plurality of transistors, the electronic card comprising at least first connection pads connected to the electronic chip, second connection pads each connected to a transistor, and connecting tracks connecting the first connection pads to second connection pads, characterized in that a length of the longest connecting track is less than or equal to eleven millimeters.

The invention therefore proposes a particular organization of the transistors and the electronic chip on an electronic card of the computer, in such a way that a control signal, for example a signal of the PWM type previously mentioned, circulating between the electronic chip and the transistors via connecting tracks, does not generate electromagnetic interference harmful to the operation of other electronic components of the vehicle. More specifically, the invention provides, by the particular arrangement of the electronic chip and of the transistors that it offers, that the level of such electromagnetic disturbances remains low enough not to cause malfunction of other electronic components of the vehicle.

Advantageously, the electronic card of the control computer according to the invention is in the form of a substantially flat plate of small thickness. More precisely, this electronic card advantageously comprises a first main face and a second main face, for example each of generally substantially rectangular shape, substantially parallel to each other and separated from each other by a thickness whose dimension, measured perpendicular to the first and second main faces, is small with regard to the dimensions of the above-mentioned main faces. Advantageously, the electronic chip, the transistors, the first pads, the second pads and the connecting tracks, previously mentioned, are placed on a main face of the electronic card. In one example, these components are placed on the same main face of the electronic card.

In the computer according to the invention, first and second pads are connected together by conductive tracks, designated in the following as connecting tracks. The length of a connecting track is here measured between a first pad and a second pad that this connecting track connects together. More precisely, the term length here designates a developed length, that is to say a length taking into account all of the possible angles, curves, and course variations that the link track considered presents between the first and the second stud. connection between which it extends. According to an example, each link track connects the electronic chip to a single transistor.

According to the invention, a length, as previously defined, of the longest connecting track is less than or equal to eleven millimeters. Such a value is defined, for example, with reference to the quantities characteristic of a signal such as a current of the PWM type previously mentioned flowing between the electronic chip and the transistors, previously defined, of the control computer according to the invention.

It should be noted that in the control computer according to the invention, the previously mentioned transistors are advantageously power transistors intended for the electrical supply of the different phases of the electric drive motor, for example of a propeller of a motor-fan unit. According to one example, the electric motor comprising three electric phases, a power transistor is configured to supply each of these phases. According to such an example, the previously defined electronic card therefore comprises three transistors, as well as three connecting tracks each connecting one of these transistors to the previously defined electronic chip.

The invention advantageously also has one or more of the following characteristics, taken separately or in combination:

- an average length of the connecting tracks is equal to seven millimeters, to the nearest five percent. Advantageously, this average length is an arithmetic average calculated over all the lengths of the previously defined connecting tracks. The tolerance of five percent here takes into account, for example, the manufacturing and installation tolerances of the connecting tracks and the connection pads on the electronic card;

- the length of the shortest connecting track is greater than or equal to five millimeters;

- At least one of the connecting tracks is straight between the first connection pad and the second connection pad between which it extends. According to an example, all the connecting tracks are rectilinear. This makes it easier to produce the connecting tracks as well as the installation of the transistors relative to the electronic chip on the electronic card;

- The electronic chip is arranged in the central position, or substantially central, of the main face of the electronic card on which it is placed;

- On the electronic card of the computer according to the invention, the transistors are arranged around the electronic chip. In other words, on the main face of the electronic card on which they are placed, the transistors at least partially surround the electronic chip. This characteristic, combined with a substantially central position of the electronic chip on the electronic card according to the invention, makes it possible to facilitate the implantation of the transistors at substantially equal distances from the electronic chip. According to one example, it is thus possible to define a substantially annular shape covering, around the electronic chip, a surface in which the transistors and the corresponding connection tracks are arranged, to the exclusion of any other component carried by the electronic card. In other words, according to such an example, on the electronic card of the computer according to the invention, there are, between the electronic chip and the transistors previously mentioned, only the previously defined connecting tracks;

the electronic card according to the invention comprises a resistance configured for the measurement of a current flowing in at least one transistor, as well as a measurement track connecting the measurement resistance to the electronic chip, and a length of the measurement is less than or equal to eleven millimeters. Such a configuration makes it possible to reduce the effects of electromagnetic disturbances circulating in a measurement track as mentioned above. As with the previously mentioned connecting tracks, the length of a measurement track is to be understood here as a developed length, that is to say a length taking into account the exact shape of the track considered, straight or having angles and / or deviations, for example;

the electronic card according to the invention comprises a plurality of resistors configured for the measurement of currents flowing in a plurality of transistors, each resistor being connected to the electronic chip by a measurement track, and a length of the most long is less than or equal to eleven millimeters. In this case, the invention also advantageously provides that an average of the lengths of the measurement tracks is equal to seven millimeters, to the nearest five percent, and that a length of the shortest measurement track is greater than or equal to five millimeters. According to one example, in this case, the measurement resistors and the corresponding measurement tracks are advantageously located in the substantially annular shape, previously defined, covering, around the electronic chip, a surface in which the transistors and the measurement tracks are arranged. previously defined link;

- A measurement track connecting a measurement resistor to the electronic chip is rectilinear, or substantially rectilinear. According to an example in which several measurement resistors and measurement tracks are arranged on the electronic card of the control computer according to the invention, all the measurement tracks are rectilinear, or substantially rectilinear;

- The control computer according to the invention comprises a housing defining an interior volume in which an electronic card as previously described is received. In the context of a preferred application of the invention to a computer intended to equip a motor-ventilator group arranged on the front face of a motor vehicle, such a housing is advantageously waterproof in order to protect the electronic card and the components that it carries moisture present in the ambient air, in particular the transistors, the connection tracks and possible resistances and measurement tracks.

By implementing simple and inexpensive means which have just been described, such as a particular arrangement of an electronic chip and of transistors which it governs on an electronic card carrying these components, the invention achieves the object well. that it was fixed, by reducing the electromagnetic disturbances generated by a control and command signal flowing between the electronic chip and the aforementioned transistors, in particular in the case where this signal is a current with pulse width modulation, or PWM current as previously mentioned.

The invention also extends to a motor-fan unit of a motor vehicle, comprising an electric motor, a propeller rotated by the electric motor, and a control computer as described above, in which the electric motor is governed by the control computer.

Other characteristics, details and advantages of the invention will appear more clearly with the aid of the following description and the drawings, among which:

FIG. i is a simplified schematic view of a control computer according to an exemplary embodiment of the invention,

- And Figure 2 is a schematic view of a motor fan unit comprising a control computer according to the invention.

It should first of all be noted that if the figures show the invention in detail for its implementation, they can of course be used to better define the invention if necessary. It should also be noted that, in all of the figures, similar elements and / or fulfilling the same function are indicated by the same reference.

Referring to the above, Figure i schematically illustrates a first main face io of an electronic card i of a control computer too according to the invention, the electronic card i comprising a second main face, not visible in the figure i, substantially parallel to the first main face io, and opposite the latter. According to one example, the first main face io and the second main face of the electronic card i are separated from each other by a thickness of small dimension with regard to the dimensions of the main faces.

With reference to FIG. I, the electronic card i notably comprises an electronic chip 2 configured to govern the operation of a motor-fan unit 6oo of a motor vehicle, for example a motor-fan unit 6oo placed on the front face of a vehicle and intended to generate an air flow passing through at least one heat exchanger. Such a motor-driven fan unit 6oo is schematically represented in FIG. 2.

The electronic chip 2 according to the invention integrates in a single electronic component a microcontroller 2a and a control member 2b configured to allow the microcontroller 2a to interact with the transistor (s) 3. The microcontroller 2a is the portion of the electronic chip 2 which performs the calculations and makes the decision-making choices, while the control unit 2b transforms this calculation or these choices into electrical information, for example of the PWM type, as mentioned above.

More specifically, the electronic chip 2 is advantageously configured to generate a set of control and command signals of an electric motor 400 of such a motor-fan unit 600 and to transmit these signals to a plurality of transistors 3 configured to control the aforementioned electric motor 400. To this end, each transistor 3 comprises, according to the example illustrated in FIG. 1, a first part 30 by which it is electrically connected to an electrical supply, and a second part 31 by which it is connected to the above-mentioned electric motor 400, not visible in FIG. 1, via a power track represented by an arrow 35 in FIG. 1.

According to an exemplary embodiment, the signals transmitted by the electronic chip 2 to the transistors 3 take the form of a current with pulse width modulation, also designated under the term of PWM according to the English acronym for Pulse-Width. modulation.

According to the example more particularly illustrated in FIG. 1, the electronic card 1 comprises three power transistors 3, respectively 3a, 3b, 3c, each of which is configured to control, as a function of the signals received from the electronic chip 2, a phase electric motor considered. According to this exemplary embodiment, the electronic chip 2 is placed in a substantially central position on the main face 10 of the electronic card 1, and the transistors 3a, 3b, 3c, are arranged on this main face 10 so that they surround partially the electronic chip 2. More precisely, according to this exemplary embodiment, the transistors 3a, 3b, 3c, surround the electronic chip 2 substantially on three sides thereof.

To make the electrical connection necessary for the transmission of signals between the electronic chip 2 and the transistors 3a, 3b, 3c, the electronic chip 2 comprises first connection pads 5 and the transistors 3 comprise a second connection pad 6. According to a example, each transistor 3 has a second connection pad 6.

The first connection pads 5 and the second connection pads 6 are interconnected by connecting tracks 7. According to the example more particularly illustrated in FIG. 1, each first connection pad 5 of the electronic chip 2 is connected to a transistor 3 by a connecting track 7. More precisely, each connecting track 7 connects together a single first connection pad 5 and a single second connection pad 6. According to the embodiment more particularly illustrated in FIG. 1 , in which the electronic card i comprises three transistors 3a, 3b, 3c, three connecting tracks, respectively 7a, 7b, 7c, are therefore arranged on the electronic card 1.

Advantageously, at least one of the connecting tracks 7 is straight. According to the example illustrated in FIG. 1, all the connecting tracks 7a, 7b, 7c are rectilinear, or substantially rectilinear.

According to the invention, a length 200 of the longest connecting track 7, here the connecting track 7a, is less than or equal to eleven millimeters. The length 200 is measured from the first connection pad 5 to the second connection pad 6 that the connecting track 7a connects together, that is to say that it is here a developed length of the track link 7a, taking into account any possible changes in direction of the link track 7a. In other words, the length 200 takes into account all the possible angles and the possible curves that the connecting track 7a could include.

As mentioned above, the invention also provides that an arithmetic average of the lengths of the connecting tracks 7 as defined above is equal to seven millimeters, to the nearest five percent. According to the example illustrated in FIG. 1, an arithmetic average of the lengths, respectively referenced 200, 210, 200, of the connecting tracks 7a, 7b, 7c, is therefore between approximately six millimeters and sixty-five hundredths of a millimeter and seven millimeters and thirty-five hundredths of a millimeter. Such a tolerance takes into account the installation tolerances of the first and second connection pads 5, 6, on the electronic card 1, as well as the production tolerances of the connecting tracks 7a, 7b, 7c.

The invention also provides that the length of the shortest connecting track 7b, 7c is greater than or equal to five millimeters. It therefore follows from the above that the lengths of the connecting tracks 7a, 7b, 7c are, according to the invention, all between five and eleven millimeters. It follows that one can define, around the electronic chip 2, a substantially annular surface, not shown in FIG. 1, in which the transistors 3 and connecting tracks 7a, 7b, 7c are inscribed. exclusion of any other electronic component carried by the electronic card 1.

According to the example more particularly illustrated in FIG. 1, a measurement resistor 4 is arranged on the supply track 35 which connects the second part 31 of the transistor to the phase of the electric motor. The measurement resistor 4 is configured to allow a measurement of the current supplying the phase of the motor. According to the invention, a maximum length of a measurement track 8 which connects the measurement resistor 4 to the electronic chip 2 is less than or equal to eleven millimeters. Thus, the electromagnetic disturbances possibly generated by the circulation of a measurement current in the portion of the electrical circuit constituted by the measurement resistor 4 and the aforementioned measurement track 8 are reduced to levels which do not cause other malfunctions. components carried by the electronic card 1 or other electronic devices located in the vicinity of the control computer 100 according to the invention. As for the connecting tracks 7, 7a, 7b, 7c, the length of the measurement track 8 designates here a developed length of this track, taking into account any possible changes of direction of the latter when the latter is not not straight.

According to an example not illustrated in FIG. 1, several measurement resistors 4 are arranged on the electronic card 1, for example a measurement resistance 4 is associated with each transistor 3a, 3b, 3c. In this case, the invention advantageously provides that an arithmetic average of the lengths of the different measurement tracks 8 is approximately seven millimeters, to the nearest five percent. The invention also advantageously provides, in this case, that a length of the shortest measurement track 8 is greater than or equal to five millimeters. Advantageously, according to such an example, the measurement resistors 4 and measurement tracks 8 at least partially surround the electronic chip 2.

It therefore follows from the above that, in this case, the measurement resistors 4 and the measurement tracks 8 extend in the annular surface previously defined, in which are located the transistors 3a, 3b, 3c, and the tracks of bond 7a, 7b, 7c. The components generating electromagnetic disturbances are thus grouped and concentrated around the electronic chip, so as to limit their antenna effect.

FIG. 2 schematically illustrates a motor-driven fan 6oo intended for example to be installed on the front face of a motor vehicle, in section along an axis of rotation X of a propeller of motor-driven fan 6oo comprises.

With reference to FIG. 2, such a motor-driven fan 6oo comprises an electric motor 400, for example formed by a rotor 410 shown diagrammatically in FIG. 2, movable in rotation around an axis X, and a stator 420 statically mounted relative to the rotor 410. According to this example, it will be noted that the rotor 410 is a rotor arranged outside the stator 420. The motor-fan 600 also comprises a propeller 650 driven in rotation by the electric motor 400. Advantageously , the propeller 650 is mounted integral with the aforementioned rotor 410, in such a way that it is rotated about the axis X previously defined by the rotation of the rotor 410 around this same axis of rotation.

The fan motor 600 also includes a control computer 100 as previously described and illustrated in FIG. 1, configured to supply and control the electric motor 400. Advantageously, the electric motor 400 and its control computer 100 are interconnected by an interconnection device referenced 500 in FIG. 2, and the control computer 100 is electrically supplied by a cable 501 by which power signals arrive, and control signals arrive towards or leave the control computer 100.

In a motor-driven fan 600 according to the invention, the control computer 100 comprises a housing 9 delimiting an interior volume 90 in which an electronic card 1 as received above is received. Given the environment in which the control computer 100 is placed, the box 9 is advantageously waterproof.

The invention, as just described, achieves the goals it had set for itself and allows, by simple and inexpensive means, to limit the effects of electromagnetic disturbances generated by a signal passing between a electronic chip of the control computer of a motor-ventilator on the front side of a motor vehicle and various components, such as, for example, power transistors or current measurement resistors, of such a control computer.

The invention cannot however be limited to the means and configurations described and illustrated, and it also applies to all means or equivalent configurations and to any combination of such means. In particular, the invention applies regardless of the type of signal passing between an electronic chip 5 of a control computer as previously described and one or more electronic components governed by the aforementioned electronic chip.

Claims (10)

1. Control computer (100) of a motor-driven fan unit (6oo) of a vehicle, comprising at least one electronic card (1) comprising an electronic chip (2) and a plurality of transistors (3, 3a, 3b , 3c), the electronic chip (2) being configured to control the plurality of transistors (3, 3a, 3b, 3c), the electronic card (1) comprising at least first connection pads (5) connected to the electronic chip (2), at least second connection pads (6) each connected to a transistor (3, 3a, 3b, 3c) and at least connection tracks (7, 7a, 7b, 7c) connecting the first connection pads (5) to the second connection pads (6), characterized in that a length (200) of the longest connecting track (7, 7a, 7b, 7c) is less than or equal to eleven millimeters. 2. Control computer (100) according to the preceding claim, wherein an average length of several connecting tracks (7, 7a, 7b, 7c) is equal to seven millimeters, to the nearest five percent. 3. Control computer (100) according to any one of the preceding claims, in which a length (210,220) of the shortest connecting track (7,7a, 7b, 7c) is greater than or equal to five millimeters. 4. control computer (100) according to any one of the preceding claims, in which one of the connecting tracks (7, 7a, 7b, 7c) is substantially rectilinear between the first connection pad (5) and the second pad connection (6) between which it extends. 5. Control computer (100) according to any one of the preceding claims, in which the transistors (3,3a, 3b, 3c) are arranged around the electronic chip (2). 6. control computer (100) according to any one of the preceding claims, comprising at least one measurement resistor (4) configured for the measurement of an electric current flowing in at least one transistor (3,3a, 3b, 3c ), as well as a measurement track (8) connecting the measurement resistor (4) to the electronic chip (2), in which a length of the measurement track (8) is less than or equal to eleven millimeters. 7 · control computer (100) according to the preceding claim, wherein the measurement track (8) is substantially rectilinear. 8. control computer (100) according to any one of the preceding claims, in which the electronic chip (2) is configured to control the 5 transistors (3, 3a, 3b, 3c) using pulse width modulation current. 9. Control computer (100) according to any one of the preceding claims, comprising a housing (9) defining an interior volume (90) in which the electronic card (1) is received. 10. Motor-fan unit (600) of a vehicle comprising an electric motor (400), a propeller (650) set in rotation by the electric motor (400) and a control computer (100) according to any one of the previous claims, the electric motor (400) being governed by the control computer (100).