JP2000043740A - Electric power steering circuit device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify a manufacturing process by integratedly forming a case to store a bridge circuit, a wiring pattern, a microcomputer and peripheral circuit elements with a connector, and providing an extension terminal in which a lead terminal of the connector is extended so as to be directly connected to a circuit board. SOLUTION: An electric power steering circuit device in which a shield cover 1B is assembled, and electromagnetic-noise is shut off from the circuit device is provided with a first circuit board 64 comprising an insulation printed circuit board on which small current parts such as a microcomputer and its peripheral circuits are mounted, and a second circuit board 65 comprising a metallic circuit board excellent in heat conductivity on which large current parts such as semi-conductor switching elements Q1, Q3 and a shut resistor 43 are mounted. The circuit boards 64, 65 are assembled with upper and lower surfaces of a case 62 integrated with a connector 45. A lead terminal of the connector 45 is extended in the case 62, and connected to an extension terminal 67 through a wiring pattern formed on a bottom surface of a recessed part of the case.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric power steering device which assists a steering device of a vehicle by the rotational force of a motor, and more particularly to a control device for the electric power steering device.

[0002]

2. Description of the Related Art FIG. 4 is a circuit diagram partially showing a block diagram of a general electric power steering control device. In FIG. 4, reference numeral 40 denotes an auxiliary torque output to a steering wheel (not shown) of a vehicle. A motor 41 is a battery for supplying a motor current IM for driving the motor 40.

Reference numeral 42 denotes a large-capacity (about 3600 μF) capacitor for absorbing a ripple component of the motor current IM; 43, a shunt resistor for detecting the motor current IM; And a bridge circuit including a plurality of semiconductor switching elements (for example, FETs) Q1 to Q4 for switching according to the direction, and 49 is a coil for removing electromagnetic noise.

L1 is a conductive line connecting one end of the capacitor 42 to the ground, P1 and P2 are wiring patterns connecting the semiconductor switching elements Q1 to Q4 in a bridge and connecting the shunt resistor 43 and the bridge circuit 44, and P3 is a bridge circuit. 44 is a wiring pattern serving as an output terminal.

[0005] Reference numeral 45 denotes a connector comprising a plurality of lead terminals for connecting the motor 40 and the battery 41 to the bridge circuit 44; L2, external wiring for connecting the motor 40 and the battery 41 to the connector 45; A normally-open relay for turning off the power of the IM as necessary, P4 is a wiring pattern for connecting the relay 46, the capacitor 42 and the shunt resistor 43, and P5 is a connector 4
5 is a wiring pattern for connecting 5 to the ground. The wiring pattern P3 serving as an output terminal of the bridge circuit 44 is connected to the connector 45.

Reference numeral 47 denotes a motor 4 via a bridge circuit 44.
A driving circuit that drives the relay 46 while driving 0.
L3 is a conductive line that connects the drive circuit 47 to the exciting coil of the relay 46, L4 is a conductive line that connects the drive circuit 47 to the bridge circuit 44, and 48 is a motor that detects the motor current IM via one end of the shunt resistor 43. The driving circuit 47 and the motor current detecting means 48 constitute a peripheral circuit element of a microcomputer described later.

Reference numeral 50 denotes a torque sensor for detecting a steering torque T of a steering wheel, and reference numeral 51 denotes a vehicle speed sensor for detecting a vehicle speed V of the vehicle. Reference numeral 55 denotes a microcomputer (ECU) which calculates an auxiliary torque based on the steering torque T and the vehicle speed V and feeds back the motor current IM to generate a drive signal corresponding to the auxiliary torque.
4 is input to the drive circuit 47 as a drive signal.

The microcomputer 55 includes a motor 40
A motor current determining means 56 for generating a motor current command Im corresponding to the rotational direction command D0 and the auxiliary torque, a subtracting means 57 for calculating a current difference ΔI between the motor current command Im and the motor current IM, and a current deviation ΔI P (proportional)
And a PID calculating means 58 for calculating a correction amount of the term, I (integral) term and D (differential) term to generate a current control amount I0 corresponding to the PWM duty ratio.

Although not shown, the microcomputer 55 includes a well-known self-diagnosis function in addition to an AD converter, a PWM timer circuit, and the like, and constantly performs self-diagnosis as to whether or not the system is operating normally. When an abnormality occurs, the relay 46 is opened via the drive circuit 47 and the motor current IM
Is to be shut off. L5 is a conductive line for connecting the microcomputer 55 to the drive circuit 47.

Generally, circuit elements 42 to 44 and 49, wiring patterns P1 to P5, and conductive lines L1 and L2 interposed between the motor 40 and the battery 41 correspond to a large motor current IM. In consideration of heat dissipation (heat resistance) and durability, the size is large. On the other hand, the peripheral circuit elements including the microcomputer 55, the drive circuit 47, and the motor current detection circuit 48, and the conductive lines L3 to L5 are configured to be small in size because they correspond to small currents and are required to have high density.

FIG. 5 is a plan view showing a circuit structure of a general electric power steering control device.
4, 42, 43, 45, 46, 49 and 55 are the same as those shown in FIG. In this case, each of the semiconductor switching elements Q1 to Q4 has a pair of F
ET, the large-capacity capacitor 42 is formed by three capacitors, and the microcomputer 55
Is constituted by a one-chip IC. In addition, in order to prevent the drawing from being complicated, peripheral circuit elements, wiring patterns, conductive lines, and the like are omitted, and only typical components are shown.

1 is a box-shaped metal frame that also functions as a shield plate and a heat sink, 2 is an insulated printed circuit board mounted on the bottom surface of the metal frame 1, and 3 is one end face on the inner side surface of the metal frame 1. It is, for example, a radiator plate made of aluminum joined. Each of the circuit elements 42,
43, 46, 49, 55, etc. are mounted, and each semiconductor switching element Q
1 to Q4 are joined.

Reference numerals 4a to 4e denote wiring boards corresponding to the wiring patterns P1 to P5 and the like. In order to cope with a large current exclusively, a conductive board having a large width and a large thickness separately from the wiring patterns on the insulated printed circuit board 2. Is used.

Next, the operation of the conventional electric power steering control device shown in FIG. 5 will be described with reference to FIG. The microcomputer 55 takes in the steering torque T and the vehicle speed V from the torque sensor 50 and the vehicle speed sensor 51, and feeds back the motor current IM from the shunt resistor 43, and corresponds to the power steering rotation direction command D0 and the auxiliary torque amount. And a current control amount I0 to be controlled by the driving circuit 47 via the conductive line L5.
To enter.

In the steady driving state, the drive circuit 47 closes the normally open relay 46 by a command via the conductive line L3. When the rotation direction command D0 and the current control amount I0 are input, the drive circuit 47 generates a PWM drive signal. The semiconductor switching elements Q1 to Q4 of the bridge circuit 44 are generated through the conductive line L4.
Is applied.

As a result, the motor 40 is
Motor current IM supplied from the external wiring L2, connector 45, coil 49, relay 46, wiring pattern P4, shunt resistor 43, wiring pattern P1, bridge circuit 44, wiring pattern P3, connector 45 and external wiring L2 , And outputs a required amount of auxiliary torque in a required direction.

At this time, the motor current IM is detected via the shunt resistor 43 and the motor current detecting means 48 and fed back to the subtracting means 57 in the microcomputer 55 so that the motor current IM matches the motor current command Im. Is controlled. The motor current IM includes a ripple component due to the switching operation at the time of PWM driving of the bridge circuit 44, but is suppressed by being smoothed by the large-capacity capacitor 42. Furthermore, the coil 49 prevents the noise generated by the switching operation of the bridge circuit 44 from being performed during the PWM driving from being emitted to the outside and becoming radio noise.

By the way, the value of the motor current IM controlled by this type of electric power steering control device is about 25 A even in a light car, and is about 60 A in a small car.
A to about 80A. Therefore, the bridge circuit 44
Of the semiconductor switching elements Q1 to Q4 are increased in size according to the magnitude of the motor current IM, and a plurality of the semiconductor switching elements are connected in parallel as shown in FIG.
It is necessary to suppress heat generation during switching.

Further, the semiconductor switching elements Q1 to Q4
In order to dissipate the heat generation amount, the heat radiating plate 3 is required. As the motor current IM increases, the number of the semiconductor switching elements Q1 to Q4 increases, and the heat radiating plate 3 also increases in size.

Further, a wiring pattern P1 from the terminal of the connector 45 to the ground via the coil 49, the relay 46, the shunt resistor 43 and the bridge circuit 44,
The lengths of P2 and P4 and the wiring pattern P3 from the bridge circuit 44 to the motor 40 are determined by the motor current I
It becomes physically longer in proportion to an increase in the current of M, an increase in the number of semiconductor switching elements Q1 to Q4, and an increase in the size of the heat sink.

As a result, if the temperature rise increases due to the amount of heat generated by the voltage drop in each of the wiring patterns P1 to P4, the heat resistance and durability of the wiring patterns P1 to P4 may be impaired. As shown in FIG. 5, large-current-only wiring boards 4a to 4e having a large width or thickness as shown in FIG.
Is used. Therefore, the size of the insulating printed board 2 is increased.

The capacitor 42 and the shunt resistor 4
3, the relay 46 and the coil 49 are connected to the motor current IM.
However, when these are to be mounted on the insulated printed circuit board 2, the mounting space is increased and the insulated printed circuit board 2 is further increased in size.

In order to solve these problems, for example, one described in JP-A-6-270824 is known. FIGS. 6A and 6B show an electric power steering circuit device described in JP-A-6-270824, in which FIG. 6A is a side sectional view (hatching is omitted), and FIG. 6B is an insulated print in FIG. It is a top view showing the state where a substrate was removed. In the drawings, the same reference numerals as those shown in FIGS. 4 and 5 indicate the same parts, and 1A and 3A
Correspond to the metal frame 1 and the heat sink 3, respectively.

The circuit configuration (not shown) is as shown in FIG. 4, and the normal circuit operation is the same as described above. In this case, the insulated printed circuit board 2 has mounted thereon a microcomputer 55 and peripheral circuit elements of a small current such as an interface circuit, a power supply circuit, a logic circuit and a signal processing circuit belonging to the microcomputer 55. Further, the torque sensor 50 and the vehicle speed sensor A sensor signal connector (not shown) connected to 51 (see FIG. 5) is provided.

The heat radiating plate 3A has a function of a shield plate below the circuit device. The metal frame 1A is electrically connected to the heat radiating plate 3A to form a complete shield structure. Blocks noise. 2
A is another insulated printed circuit board mounted on the heat sink 3A, which is divided from the insulated printed circuit board 2 on which the microcomputer 55 is mounted, and on which a drive circuit (peripheral circuit element) 47 composed of an IC chip is mounted. Is placed.

Reference numeral 10 denotes a metal substrate made of, for example, a HITT substrate (trade name) manufactured by Denki Kagaku Kogyo Co., Ltd. The wiring pattern P is a 100 μm copper pattern (20 μm aluminum) on a 3 mm aluminum substrate via an 80 μm insulating layer. Film is coated). The wiring pattern P is a general term for P1 to P5 and the like, and here only a part is shown.

The back surface of the metal substrate 10 is fixed to the heat radiating plate 3A, and the heat radiating function is enhanced. Metal substrate 10
The divided printed circuit boards 2A are arranged in parallel in the horizontal direction.

As shown in the figure, on the wiring pattern P joined and disposed on the metal substrate 10 with the insulating layer interposed therebetween,
The shunt resistor 43 and the bridge circuit 44 are mounted, and the metal substrate 10 also functions as a heat sink.
The wiring pattern P formed on the metal substrate 10 is
A circuit element having a sufficient cross-sectional capacity to cope with a large current and through which the motor current IM flows can be mounted.

The number of the semiconductor switching elements Q1 to Q4 constituting the bridge circuit 44 is, for example, eight (two each).
And is soldered to a primary heat sink (not shown) via copper or molybdenum, and further soldered to a wiring pattern P (P1 to P3, etc.) on the metal substrate 10. The wires are connected by aluminum bonding or the like, and are bridge-connected to the motor 40 of FIG.

As described above, by using bare-chip semiconductor switching elements Q1 to Q4 which are smaller in size than ordinary elements because they are not covered with resin,
The bridge circuit 44 can be arranged in a small space on the metal substrate 10. Therefore, even if three or more semiconductor switching elements Q1 to Q4 are connected in parallel with each other by increasing the motor current IM, compact mounting can be achieved.

Further, the semiconductor switching elements Q1 to Q4
In addition, the amount of heat generated from the wiring pattern P is effectively transmitted to the heat radiating plate 3A via the metal substrate 10 and is radiated to the outside air from the heat radiating plate 3A. it can.

Reference numerals 14a to 14g denote a plurality of leads protruding from the wiring pattern P on the metal substrate 10,
The leads 14a and 14g correspond to the wiring pattern P4 and the conductive line L3 of the relay 46.

Reference numeral 5 denotes an insulating support member interposed between the metal substrate 10 and the insulated printed circuit board 2;
The capacitor 42, the connector 45, and the relay 46 are attached while maintaining a predetermined interval between 0 and the insulating printed board 2. The insulating printed board 2 and the metal board 10 sandwich the support member 5 from above and below, and are superposed at a predetermined interval from each other.

The capacitor 42 is soldered to a pattern on the pointing member 5 via an electrode terminal 42a and a support terminal 42b. The ground (−)-side electrode terminal 42 a of the capacitor 42 is connected to the ground terminal of the connector 45, and the anode (+)-side electrode terminal 42 a is connected to the lead 14.
e, and is connected to the shunt resistor 43 through the support terminal 4
2b fixes the other end of the capacitor 42 on the support member 5.

The connector 45 is attached to the support member 5 in a frame shape by, for example, integral molding of an insert resin mold, and has an extension terminal portion 45a inside. The extension terminal portion 45a is electrically connected to the leads 14a to 14d projecting in a bar shape from the metal substrate 10.

As shown in FIG. 4, the motor 40 and the battery 41 are connected to the outer terminal of the connector 45 via the external wiring L2. The connector 45 may form a male pin, or may form a screw-type connection terminal.

In the relay 46, the relay contact terminal on the battery 41 side is connected to the battery terminal of the connector 45, and the relay contact terminal on the bridge circuit 44 side is connected to the wiring pattern P4 via the lead 14a.

As described above, the large-capacity capacitor 42, the connector 45, and the relay 46, which require a large mounting space and are difficult to mount on the metal substrate 10, are mounted on the support member 5 located on the intermediate layer. 10
It is electrically connected to the wiring pattern P via the leads 14a to 14g projecting upward.

Accordingly, the wiring pattern P on the metal substrate 10
In this case, the degree of freedom in the structural design between the capacitor 42 and each terminal of the relay 46 and the extension terminal 45a of the connector 45 is increased, and the wiring length can be reduced compactly and effectively. Further, the insulating printed board 2 and the metal board 10 disposed above and below the support member 5 can also be reduced in size because the use space is effectively omitted.

On the other hand, a drive circuit 47 mounted as a hybrid IC on an alumina thick film substrate of another insulated printed circuit board 2A is connected to a bridge circuit 44 on the metal substrate 10 via a conductive line L4, and a conductive line L5 Is connected to a microcomputer 55 on the insulated printed circuit board 2.

As described above, by using the divided insulating printed board 2A separately from the upper insulating printed board 2 and arranging it on the same plane as the lower metal board 10, the waste space on the metal board 10 side is reduced. Is eliminated, and further downsizing can be realized. Accordingly, high-density mounting of the microcomputer 55 and its peripheral circuit elements (such as the drive circuit 47) can be realized.

Further, a metal frame 1A serving as a shield plate
Are insulated printed circuit boards 2 and 2 in cooperation with heat sink 3A.
A is completely covered, and electromagnetic noise that can be input to the insulated printed circuit boards 2 and 2A is reliably blocked.

[0043]

In the conventional electric power steering circuit device configured as described above, when the extension terminal portion of the connector and the lead projecting in a rod shape from the metal substrate are electrically connected, Since the three-dimensional positioning of the extension terminal portion and the lead in the front-rear direction, the left-right direction, and the up-down direction is required, there is a problem that the positioning is very difficult.

In order to make the leads project from the metal substrate in a bar shape, the first soldering is performed when the lead is attached to the metal substrate, and the second soldering is performed at the time of connection with the extension terminal portion of the connector. Is required, and there is a problem that the manufacturing process becomes complicated.

Further, as described above, after soldering the metal substrate and the lead, when positioning for connection between the lead and the extension terminal portion of the connector, the soldered portion on the metal substrate is When stress is applied, for example, when installed in the engine compartment, the temperature around the circuit device fluctuates due to the heat generated by the engine, or when installed in the compartment, the cabin when the vehicle is left under the sun The lead expands and contracts due to fluctuations in the peripheral temperature of the circuit device due to the rise in temperature, and stress is applied to the soldered portion, which may eventually cause the solder to come off, resulting in reduced reliability. .

Furthermore, in order to mount a large-capacity capacitor, connector and relay requiring a large mounting space to a support member located in the intermediate layer, an upper insulating printed board, an intermediate layer support member, a lower metal substrate or A certain space is required between the divided insulated printed circuit boards, and there is a problem that the vertical dimension of the circuit device cannot be reduced.

[0047]

An electric power steering circuit device according to the present invention includes a motor for outputting an auxiliary torque to a steering wheel of a vehicle, a battery for supplying a motor current for driving the motor, and the motor. A bridge circuit including a plurality of semiconductor switching elements for switching a current according to the auxiliary torque, a board on which at least the bridge circuit is mounted, a wiring pattern for connecting the semiconductor switching elements in a bridge and connecting the bridge circuit, and the motor A connector for connecting the battery to the bridge circuit, a torque sensor for detecting a steering torque of the steering wheel, a vehicle speed sensor for detecting a vehicle speed of the vehicle, the bridge circuit based on a steering torque of the steering wheel and a vehicle speed of the vehicle. Drive signal to control In generating electric power steering circuit device having a microcomputer and a peripheral circuit element To, the bridge circuit, the wiring pattern,
A case accommodating the microcomputer and the peripheral circuit element and the connector are integrally formed, and an extension terminal is provided by extending a lead terminal of the connector so as to be directly connected to the substrate.

The extension terminals obtained by extending the lead terminals of the connector are obtained by reducing the width of some or all of the terminals.

The extension terminals obtained by extending the lead terminals of the connector are obtained by reducing the thickness of some or all of the terminals.

The extension terminal, which is an extension of the lead terminal of the connector, has its terminal length longer than necessary.

Also, at least one of a capacitor for absorbing a ripple component of a motor current, a relay for supplying and blocking a motor current, and a coil for removing electromagnetic noise is mounted on a wiring pattern formed by extension terminals. It is.

Further, the case is provided with a concave portion into which at least one of a capacitor, a relay and a coil is inserted.

In addition, the heat sink attached to the case
At least one of a capacitor, relay, or coil
It has a cut-out portion for accommodating one.

Further, the substrate on which the bridge circuit, the microcomputer, the peripheral circuit elements and the like are mounted is a first substrate on which the microcomputer and the peripheral circuit elements are mounted.
It is divided into a substrate and a second substrate on which at least a bridge circuit is mounted.

The conductive lines connecting the first substrate and the second substrate are provided at least independently of the case.

The substrate on which the bridge circuit is mounted is formed of a metal substrate having excellent heat conductivity.

Further, the outer periphery of the case is covered with a shield cover for performing electric shielding.

[0058]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows the structure of Embodiment 1 of the present invention, and the same reference numerals as those in FIGS. The circuit configuration is the same as in FIG.
In addition, the operation is the same, and a detailed description is omitted here.

In FIG. 1, reference numeral 1B denotes a shield cover which, when assembled (not shown), surrounds the circuit device and blocks electromagnetic noise to the circuit. Reference numeral 64 denotes a first substrate on which the small current components such as the microcomputer 55 and its peripheral circuits are mounted, and is constituted by an insulated printed circuit board. Reference numeral 65 denotes a second substrate on which high-current components such as the semiconductor switching elements Q1 to Q4 and the shunt resistor 43 are mounted, and is formed of a metal substrate having excellent heat conductivity. In other words, a small-current component is mounted on an insulated printed circuit board, and a large-current board is mounted on a metal substrate to form a two-substrate structure. At the same time, the heat generated by the large-current components is transmitted to a heat radiating plate 3B, which will be described later, through a metal substrate having excellent heat conduction, thereby promoting heat release to the outside and improving the reliability of the device.

Reference numeral 62 denotes a case in which the connector 45 is formed integrally. The case 62 is provided with the connector 4
5 is insert molded, and the lead terminal is extended into the case 62, forms a wiring pattern P6 on a bottom surface 66A of a case recess 66 described later, and is further extended, and the second substrate 65 An extension terminal 67 for connecting to the terminal is formed.

Reference numeral 3B denotes a heat sink, which is attached so as to be in contact with the second substrate constituted by the metal substrate.
The heat generated by the electric components mounted on the second substrate is released to the outside. In the heat sink 3B, a concave notch 3 is formed in a portion facing the concave 66 of the case 62.
C is formed. When the heat radiating plate 3B is not provided, a protection cover (not shown) for covering the concave portion 66 of the case 62 is provided.

Next, the assembly of the above circuit device will be described. On the second substrate 65 on which cream solder is applied to each electrode, electric components such as the semiconductor switching elements Q1 to Q4, the shunt resistor 43, and the case 62 are arranged. At this time, the extension terminal 67 extending from the case 62
Then, the electrode 65A on the second substrate 65 opposed to the extension terminal 67 is positioned, but the positioning can be performed by adjusting the position of the extension terminal 67 to the electrode 65A, so that the positioning can be easily performed. As described above, the second substrate on which the components are arranged is heated from below or the entire surrounding atmosphere, the previously applied cream solder is melted, and the components are soldered.
Thereby, the connection of various electric components and the connection between the terminal from the connector 45 and the second substrate can be completed by a single soldering operation, and the manufacturing process can be simplified.

The detailed shape of the extension terminal 67 will be described with reference to FIG. (A) is a cross-sectional view of a part of the case 62, (b) is a plan view of a part of the case 62, and as shown in the drawing, the extension terminal 67 has a part thereof having a width. When the extension terminal 67 and the electrode 65A on the second substrate 65 are positioned, the extension terminal 67 is aligned with the electrode 65A when the extension terminal 67 is aligned with the electrode 65A. The applied force is reduced, and the stress applied to the soldered portion between the extension terminal 67 and the electrode 65A can be reduced. Further, even when the extension terminal 67 expands and contracts due to heat, the stress is applied to the portion where the width of the extension terminal 67 is narrowed, so that the stress applied to the soldered portion can be reduced, and disconnection due to solder dislocation is prevented. And the reliability of the circuit device can be improved.

In the above description, the stress applied to the soldered portion is reduced by reducing the width of a part of the extension terminal 67. However, even if the width of the extension terminal itself is not reduced, FIG. As shown in c), by providing the hole 67A in a part of the extension terminal, the net width can be reduced, and the stress applied to the soldered portion can be reduced. Also, as shown in FIG. 2D, the thickness of a part of the extension terminal 67 may be reduced, or the thickness of the entire extension terminal 67 may be reduced.
It goes without saying that the stress applied to the soldered portion can be reduced. Further, originally, the length of the extension terminal 67 is determined by the length necessary for connecting to the electrode 65A of the second substrate 65 as shown in FIG. By making the length of the extension terminal 67 longer than the required length as described above, when a stress is applied to the extension terminal 67, the extension terminal 67 itself is easily bent, and the stress applied to the soldered portion can be reduced. . Furthermore, the width or thickness of the extension terminal is limited depending on the magnitude of the current, and the length of the extension terminal 67 is usually limited due to the size of the entire device. By adjusting the thickness and length) in combination, it is possible to adapt to the magnitude of the current, the size of the device, etc., and to reduce the stress applied to the soldered portion.

FIG. 3A is a bottom plan view of the case 62, and FIG. 3B is a side view. As shown in the figure, a concave portion 66 is provided in a part of the case 62, and a wiring pattern P6 formed by extension terminals obtained by extending the lead terminals of the connector 45 is provided on the bottom surface 66A. Of the circuit components, large components such as the capacitor 42, the relay 46, and the coil 49 are inserted into this concave portion and attached, and are connected by the wiring pattern P6.
The lead terminals of the connector 45 are thicker than the wiring pattern originally arranged on the insulated printed circuit board and the like, and can be electrically connected by the wiring pattern P6 provided by extending the wiring pattern. It is not necessary to increase the width of the circuit device, and the entire circuit device can be downsized.

When the height of the case 62 is reduced to further reduce the size of the circuit device, the case 6
The height of the capacitor 42, the relay 46, or the coil 49 becomes larger than the height of the case 2 and protrudes from the concave portion 66 of the case 62. In such a case, as shown in FIG. The condenser 42, the relay 46, the coil 49, and the like are provided by providing a concave notch 3C in the heat sink 3B that is attached to face and inserting the capacitor 42, the relay 46, the coil 49, and the like into the notch 3C. The circuit device can be further miniaturized without projecting.

A first substrate 64 on which components such as the microcomputer 55 and peripheral circuit elements through which a small current flows is mounted.
The conductive line L5 connecting the second substrate 65 on which components such as the bridge circuit 44 and the shunt resistor 43 to which a large current flows is mounted is provided independently of the case 62 as shown in FIG. When the conductive line L5 is connected to the second substrate 65, the conductive line L5 can be mounted on the substrate as one of simple electric components, so that positioning is easy, and even when connecting to the first substrate, Since it is not fixed to the case 62, positioning can be performed relatively easily. Thus, by providing the conductive line L5 independently of the case 62, the first
Connection to the substrate 64 and the second substrate 65 can be easily performed.

As described above, the components are connected and assembled, and finally, the shield cover 1B and the case 6
The circuit device is completed by connecting the heat sink 2 and the heat sink 3B with the mounting screws 61. By surrounding the case 62 with the shield cover 1B, malfunction of the device due to electromagnetic noise is prevented, and the reliability of the device is improved.

In the embodiment of the present invention described above,
The circuit board has a two-layer structure, and a heat radiating plate is used for releasing heat generated in the electric circuit. However, the present invention is not limited to this.
It goes without saying that various embodiments are included within a range that conforms to the gist of the present invention, such as using a column or a rack housing as a heat sink without specially providing a heat sink. When the influence of radio noise is slight, the coil 49 for removing radio noise may be omitted.

[0070]

As described above, according to the electric power steering circuit device of the present invention, a motor for outputting an auxiliary torque to a steering wheel of a vehicle and a motor current for driving the motor are supplied. A battery, a bridge circuit including a plurality of semiconductor switching elements for switching the motor current according to the auxiliary torque,
At least a board on which the bridge circuit is mounted, a wiring pattern for connecting the semiconductor switching elements in a bridge and connecting the bridge circuit, a connector for connecting the motor and the battery to the bridge circuit, and a torque for detecting a steering torque of the steering wheel. Electric power including a sensor, a vehicle speed sensor for detecting a vehicle speed of the vehicle, a microcomputer for generating a drive signal for controlling the bridge circuit based on a steering torque of the steering wheel and a vehicle speed of the vehicle, and a peripheral circuit element In the steering circuit device, a case accommodating the bridge circuit, the wiring pattern, the microcomputer and the peripheral circuit element, and the connector are integrally molded, and lead terminals of the connector are connected directly to the substrate. By providing long extension terminals, connection of each circuit component to the board on which the bridge circuit is mounted and connection of the extension terminals can be completed by a single soldering operation, simplifying the manufacturing process. In addition, since the positioning can be performed only by adjusting the position of the extension terminal to the position of the electrode on the substrate, there is an effect that positioning becomes easy.

Further, the extension terminal obtained by extending the lead terminal of the connector has a reduced width, partly or entirely, so that even if the extension terminal expands and contracts due to heat,
The stress applied to the soldered portion can be reduced, the solder can be prevented from coming off, and the reliability of the device can be improved.

Further, the extension terminal obtained by extending the lead terminal of the connector has a reduced thickness, partly or entirely, so that even if the extension terminal expands and contracts due to heat,
The stress applied to the soldered portion can be reduced, the solder can be prevented from coming off, and the reliability of the device can be improved.

The extension terminal obtained by extending the lead terminal of the connector has a longer terminal length than the required length, so that even if the extension terminal expands and contracts due to heat,
The stress applied to the soldered portion can be reduced, the solder can be prevented from coming off, and the reliability of the device can be improved.

Further, at least one of a capacitor for absorbing a ripple component of the motor current, a relay for supplying and interrupting the motor current, and a coil for removing electromagnetic noise is mounted on a wiring pattern formed by extension terminals. Accordingly, it is not necessary to increase the width of the wiring pattern to cope with a large current, and the circuit device can be downsized.

Further, by providing the case with a concave portion into which at least one of a capacitor, a relay, and a coil is inserted, a space required for mounting the capacitor, the relay or the coil can be used efficiently,
The circuit device can be downsized.

In addition, a heat sink attached to the case
The provision of the notch for accommodating at least one of the capacitor, the relay, and the coil can further improve the space efficiency required for mounting the capacitor, the relay, or the coil, and further reduce the size of the circuit device. Can be.

Further, the substrate on which the bridge circuit, the microcomputer, the peripheral circuit elements and the like are mounted is a substrate on which at least the microcomputer and the peripheral circuit elements are mounted.
When the circuit device is assembled by dividing the substrate into at least a second substrate on which a bridge circuit is mounted, these two substrates can be overlapped to reduce the area of the circuit device, thereby reducing the size of the circuit device. be able to.

Further, since the conductive lines connecting the first substrate and the second substrate are provided at least independently of the case, positioning and the like can be easily performed at the time of connecting the conductive lines, and the manufacturing process can be simplified.

Further, since the substrate on which the bridge circuit is mounted is made of a metal substrate having excellent thermal conductivity, the heat generated in the bridge circuit can be efficiently released to the outside, and the reliability of the device can be improved. .

Further, since the outer periphery of the case is covered with a shield cover for performing electrical shielding, malfunction of the device due to electromagnetic noise can be prevented, and reliability of the device can be improved.

[Brief description of the drawings]

FIG. 1 is a configuration diagram illustrating a configuration of an electric power steering circuit device according to a first embodiment of the present invention.

FIG. 2 is a diagram showing details of a part of the configuration of the electric power steering circuit device according to the first embodiment of the present invention;

FIG. 3 is a diagram showing details of a part of the configuration of the electric power steering circuit device according to the first embodiment of the present invention;

FIG. 4 is a circuit diagram showing a circuit configuration of a general electric power steering control device.

FIG. 5 is a configuration diagram showing a configuration of a general electric power steering control device.

FIG. 6 is a configuration diagram showing a configuration of a conventional electric power steering circuit device.

[Explanation of symbols]

 3B: Heatsink 42: Capacitor 43: Shunt resistor 44: Bridge circuit 44 46: Relay 49: Coil 45: Connector 62: Case 65: Second board 67: Extension terminal

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Hiroshi Watanabe 2-6-1 Otemachi, Chiyoda-ku, Tokyo F-term in Mitsubishi Electric Engineering Co., Ltd. 3D033 CA03 CA13 CA16 CA20 CA21 CA32

Claims (11)

[Claims] 1. A motor for outputting an auxiliary torque to a steering wheel of a vehicle, a battery for supplying a motor current for driving the motor, and a plurality of semiconductor switching elements for switching the motor current according to the auxiliary torque. , A board on which at least the bridge circuit is mounted, a wiring pattern for connecting the semiconductor switching elements in a bridge and connecting the bridge circuit, a connector for connecting the motor and the battery to the bridge circuit, and steering of the handle A torque sensor for detecting torque, a vehicle speed sensor for detecting the vehicle speed of the vehicle, a microcomputer for generating a drive signal for controlling the bridge circuit based on the steering torque of the steering wheel and the vehicle speed of the vehicle, and a peripheral circuit element. Equipped electric power In the steering circuit device, the bridge circuit, the wiring pattern, the case accommodating the microcomputer and the peripheral circuit element, and the connector are integrally molded, and lead terminals of the connector are connected directly to the substrate. An electric power steering circuit device comprising an extended extension terminal. 2. The electric power steering circuit device according to claim 1, wherein a part or all of the extension terminals obtained by extending the lead terminals of the connector have a reduced width. 3. The electric power steering circuit device according to claim 1, wherein a part or the whole of the extension terminal obtained by extending the lead terminal of the connector has a reduced thickness. 4. The electric power steering circuit device according to claim 1, wherein the extension terminal obtained by extending the lead terminal of the connector has a terminal length longer than a required length. 5. At least one of a capacitor for absorbing a ripple component of a motor current, a relay for supplying and interrupting a motor current, and a coil for removing electromagnetic noise is mounted on a wiring pattern formed by extension terminals. The electric power steering circuit device according to claim 1, wherein: 6. The electric power steering circuit device according to claim 5, wherein a concave portion into which at least one of a capacitor, a relay, and a coil is inserted is provided in the case. 7. A notch for accommodating at least one of a capacitor, a relay, and a coil is provided on a heat sink attached to the case.
7. An electric power steering circuit device according to claim 6. 8. A bridge circuit, a microcomputer,
2. The electric power supply according to claim 1, wherein the substrate on which the peripheral circuit elements are mounted is divided into at least a first substrate on which the microcomputer and the peripheral circuit elements are mounted, and at least a second substrate on which the bridge circuit is mounted. Steering circuit device. 9. The electric power steering circuit device according to claim 8, wherein the conductive line connecting the first substrate and the second substrate is provided at least independently of the case. 10. The electric power steering circuit device according to claim 1, wherein the substrate on which the bridge circuit is mounted is formed of a metal substrate having excellent heat conductivity. 11. The electric power steering circuit device according to claim 1, wherein an outer periphery of the case is covered with a shield cover for performing electric shielding.