JP2022026387A - Motor control device and electric power steering device - Google Patents

Abstract

To provide a motor control device that reduces defects such as solder cracks and suppresses manufacturing costs.SOLUTION: A motor control device includes a circuit board 13 fixed to a motor housing on the opposite output side in the axial direction of a motor. The circuit board includes a plurality of connection portions for connecting a plurality of clip terminals. Each of the plurality of connection portions has a copper foil surface 14 that is in contact with the connection surfaces of the plurality of clip terminals. The copper foil surface is formed on at least one surface of the circuit board in close proximity to the end of the circuit board, and the plurality of clip terminals are electrically connected by sandwiching the plurality of connection portions.SELECTED DRAWING: Figure 3

Description

The present invention relates to a motor control device and an electric power steering device.

In a motor control device integrated with a motor, soldering is used to connect the coil winding of the motor and the circuit board. However, solder connection affects the tact time and yield in the production process. Further, when stress is applied to the solder connection portion, there is a possibility that the solder may be cracked. In Patent Document 1, the coil winding of the motor and the circuit board are connected by a press-fit connection.

Patent 6443055

However, in the case of press-fit connection, high-precision positioning is required and strong force is required, so dedicated equipment for press-fit connection is required in the production process, and there is a problem that the manufacturing cost is high. be.

One aspect of the motor control device according to the present invention includes a circuit board fixed to a motor housing on the opposite output side in the axial direction of the motor. The circuit board has a plurality of connection portions for connecting a plurality of clip terminals. Each of the plurality of connection portions has a copper foil surface in contact with the connection surface of the plurality of clip terminals. The copper foil surface is formed on at least one surface of the circuit board in close proximity to the end of the circuit board, and a plurality of clip terminals are electrically connected by sandwiching the plurality of connection portions, and the motor control Device.

One aspect of the electric power steering device according to the present invention is an electric power steering device that assists a driver's steering wheel operation of a vehicle or the like, and is a torque sensor that detects torque due to the steering wheel operation, a motor control device, and torque. An electric power steering device including an electric motor driven by a motor control device based on a torque detected by a sensor.

According to an exemplary embodiment of the present invention, the motor control device can eliminate solder in the connection between the coil winding of the motor and the circuit board, so that defects such as solder cracks are eliminated. In addition, since a dedicated assembly device such as a press fit is not required, the manufacturing cost can be suppressed.

Further, according to the exemplary embodiment of the present invention, in the electric power steering device, since solder is not used for the connection between the motor coil winding of the motor control device and the circuit board, defects such as solder cracks are eliminated. , The failure rate of the electric power steering device is also reduced.

FIG. 1 is a perspective view showing the appearance of the motor control device according to the embodiment of the present invention. FIG. 2 is a view of the appearance of the motor control device according to the embodiment of the present invention as viewed from the cover side. FIG. 3 is a diagram showing a circuit board of a motor control device according to an embodiment of the present invention. FIG. 4a is an enlarged view of the connection portion A in FIG. FIG. 4b is an enlarged view of the connection portion A in FIG. FIG. 4c is an enlarged view of the connection portion A in FIG. FIG. 5a is a cross-sectional view showing the connection between the connection portion and the clip terminal. FIG. 5a is a cross-sectional view showing the connection between the connection portion and the clip terminal. FIG. 5a is a cross-sectional view showing the connection between the connection portion and the clip terminal. FIG. 6a is a cross-sectional view showing the fixing of the clip terminal and the connection with the motor coil winding. FIG. 6b is a cross-sectional view showing the fixing of the clip terminal and the connection with the motor coil winding. FIG. 7 is a cross-sectional view showing the connection and fixing of the copper foil surface group and the clip terminal connector in FIG. FIG. 8 is a diagram showing a schematic configuration of an electric power steering device including a motor control device according to an embodiment of the present invention.

Hereinafter, the motor control device of the present disclosure and the electric power steering device having the motor control device will be described in detail with reference to the drawings. However, in order to avoid unnecessary redundancy of the following explanations and to facilitate the understanding of those skilled in the art, more detailed explanations than necessary may be omitted. For example, detailed explanations of already well-known matters and duplicate explanations for substantially the same configuration may be omitted. The electric power steering may be referred to as EPS (Electric Power Steering).
<Explanation of structure>

FIG. 1 is a perspective view showing the appearance of the motor control device according to the embodiment of the present invention. The motor control device 10 is applied to, for example, a motor control device for electric power steering, and the motor control device 10, the motor 15, the motor housing 19, the cover 11, and the clip terminal connector 12 are integrally formed. The motor control device 10 and the clip terminal connector 12 are fixed to the motor housing 19 on the opposite output side of the motor 15 in the axial direction, and the cover 11 covers the motor control device 10.

FIG. 2 is a view of the appearance of the motor control device according to the embodiment of the present invention as viewed from the cover side. The cover 11 covers the circuit board 13 in a shape connected to a circular portion obtained by projecting the motor case 15c of the motor 15 in the axial direction and a rectangular portion connected to the circular portion.

FIG. 3 is a diagram showing a circuit board of a motor control device according to an embodiment of the present invention. The circuit board 13 is a single substrate having a circular shape inside the projection region obtained by projecting the motor case 15c of the motor 15 in the axial direction of the motor and a rectangular portion outside the projection region. be. Further, it has a plurality of connecting portions A at least at the end of the circular portion. Each of the plurality of connection portions A has at least a copper foil surface 14, and a plurality of clip terminals 16 are connected to each other. Each of the plurality of clip terminals 16 is connected to the coil winding 15w of the motor.

Further, as will be described later, a plurality of copper foil surfaces 14 arranged in a row are also provided at one end of the rectangular shape of the circuit board 13.

The circuit board 13 is fixed to the motor housing 19 with screws (not shown), for example, and is covered with a cover 11. As shown in FIG. 6a, a gap is provided between the circuit board 13 and the motor housing 19 for providing, for example, a heat radiating sheet or a heat radiating gel having electrical insulating properties. This is to dissipate the heat of the electronic component (not shown) mounted on the circuit board 13 to the motor housing 19 and to electrically insulate the electronic component (not shown) from the motor housing 19. The motor housing 19 also serves as a heat sink.

The circuit board 13 is a single circuit board on which many electronic components can be mounted, and the cost can be reduced as compared with the case where a plurality of circuit boards are configured. Further, since there is at least a connection portion A at the end of the circular portion inside the projection region, each of the plurality of connection portions A and the coil winding 15w of the motor connected via the clip terminal 16 are connected to each other. Can be connected inside the projection area.

4a to 4c are enlarged views of the connection portion A in FIG. 3, showing different embodiments.
In FIG. 4a, the circuit board 13 has a notch 13k at the end of the circular portion and a copper foil surface 14 formed on the back side of the notch at each of the plurality of connection portions A. Then, the copper foil surface 14 and the clip terminal 16 inserted into the cut portion 13k are electrically connected. By connecting the clip terminal 16 to the coil winding 15w of the motor, the copper foil surface 14 and the coil winding 15w of the motor are also electrically connected.

By providing the notch 13k in the circuit board 13, it is possible to suppress the horizontal displacement of the circuit board 13 of the clip terminal 16, so that the connection between the circuit board 13 and the clip terminal 16 can be stabilized. Become. Further, by inserting the clip terminal 16 into the notch portion, it is possible to suppress the protrusion of the clip terminal 16 in the radial direction of the motor.

The width of the cut portion 13k may be wider than the width of the copper foil surface 14 parallel to the width of the cut portion 13k. By making the width of the cut portion 13k wider than the width of the copper foil surface 14, the clip terminal 16 having a width wider than the copper foil surface 14 can be connected, so that the electrical contact surface can be widened.

Further, the length of the cut portion 13k cut into the circuit board 13 may be shorter than the length of the depth of the copper foil surface 14. By shortening the length of the cut portion 13k, it is possible to prevent the mounting area of the electronic component (not shown) of the circuit board 13 from becoming narrow.

In FIG. 4b, the circuit board 13 has a copper foil surface 14 formed between a notch 13 m at the end of the circular portion and an adjacent notch 13 m in each of the plurality of connection portions A. Have. Then, the copper foil surface 14 and the clip terminal 16 inserted into the cut portion 13 m and the adjacent cut portion 13 m are electrically connected. By connecting the clip terminal 16 to the coil winding 15w of the motor, the copper foil surface 14 and the coil winding 15w of the motor are also electrically connected.

Also in the embodiment of FIG. 4b, by providing the notch portion 13m in the circuit board 13, it is possible to suppress the displacement of the circuit board 13 of the clip terminal 16 in the horizontal direction, so that the connection between the circuit board 13 and the clip terminal 16 can be suppressed. Can be stabilized.

The width of the cut portion 13 m may be narrower than the width of the copper foil surface 14 parallel to the width of the cut portion 13 m. Since the copper foil surface 14 is formed between the notch portion 13 m and the adjacent notch portion 13 m, the electrical contact surface between the clip terminal 16 and the copper foil surface 14 can be widely secured. Further, it is possible to secure a wide distance between the connecting portion A and the adjacent connecting portion A.

Further, the length of the cut portion 13 m cut into the circuit board 13 may be longer than the length of the depth of the copper foil surface 14. By increasing the length of the cut portion 13 m, it is possible to secure a wide electrical contact surface between the clip terminal 16 and the copper foil surface 14.

In FIG. 4c, similarly to FIG. 4b, the circuit board 13 is formed in each of the plurality of connection portions A between the cut portion 13 m at the end of the circular portion and the adjacent cut portion 13 m. It has a copper foil surface 14b. Then, the copper foil surface 14b and the clip terminal 16 inserted into the notch portion 13m and the adjacent notch portion 13m are electrically connected. By connecting the clip terminal 16 to the coil winding 15w of the motor, the copper foil surface 14b and the coil winding 15w of the motor are also electrically connected.

The difference between FIGS. 4b and 4c is the shape of the copper foil surface. The copper foil surface 14 of FIG. 4a may be changed to the copper foil surface 14b of FIG. 4c.

Further, the cut portion may be a combination of the cut portion 13k of FIG. 4a and the cut portion 13m of FIG. 4b.

5a to 5c are cross-sectional views showing the connection between the connection portion A and the clip terminal 16, and show different embodiments.

In FIG. 5a, the copper foil surface 14 is formed on the upper surface side, which is at least one surface of the circuit board 13, in the vicinity of the end portion of the circuit board 13. The clip terminal 16 comes into contact with the copper foil surface 14 on the connection surface 16s of the clip terminal and sandwiches the connection portion A, whereby the clip terminal 16 and the connection portion A are electrically connected.

In FIG. 5b, the copper foil surface 14 is formed on the lower surface side, which is at least one surface of the circuit board 13, in the vicinity of the end portion of the circuit board 13. The clip terminal 16 comes into contact with the copper foil surface 14 on the connection surface 16s of the clip terminal and sandwiches the connection portion A, whereby the clip terminal 16 and the connection portion A are electrically connected.

In FIG. 5c, the copper foil surface 14 is formed on both the upper and lower sides of the circuit board 13 in the vicinity of the end portion of the circuit board 13. The clip terminal 16 comes into contact with the copper foil surface 14 on the connection surface 16s of the clip terminal and sandwiches the connection portion A, whereby the clip terminal 16 and the connection portion A are electrically connected.

That is, the copper foil surface 14 may be formed on at least one of the upper and lower surfaces of the circuit board 13 in the vicinity of the end portion of the circuit board 13.

Further, the shape of the copper foil surface 14 may be, for example, the shape of the copper foil surface 14b, and is not limited to this, and may be any shape that is electrically connected to the connection surface 16s of the clip terminal.

6a and 6b are cross-sectional views showing the fixing of the clip terminal and the connection with the motor coil winding, and show different embodiments.

In FIG. 6a, one end of the clip terminal 16 is connected to the connection portion A as shown in FIGS. 5a to 5c. The other end of the clip terminal 16 is connected to the coil winding 15w of each phase of the motor 15. The clip terminal 16 is housed inside a projection region in which the motor case 15c is projected in the axial direction of the motor. Here, the axial direction indicates the vertical direction in FIG. 6a.

The coil winding 15w of each phase of the motor 15 passes through the hole portion 19h provided in the motor housing 19 from the motor 15 side, escapes to the motor control device 10 side, and is connected to the clip terminal 16. This connection may be, for example, fitting, press-fitting, etc., or may be a connector-like type plug-in type. The hole 19h may be provided with a resin member (not shown) that insulates the coil winding 15w of each phase of the motor 15 from the motor housing 19.

In FIG. 6b, the difference from FIG. 6a is that the outside of the clip terminal 16 is molded with resin. Since the clip terminal 16 is a resin mold 16c, it is not necessary to provide a resin member (not shown) for insulating the hole 19h of the motor housing 19.

In FIGS. 6a and 6b, the coil windings 15w of each phase of the circuit board 13 and the motor 15 can be connected by the clip terminals 16 without using solder, so that solder cracks can be avoided. Further, since the clip terminal 16 is housed inside the projection region in which the motor case 15c is projected in the axial direction of the motor, it is possible to suppress the increase in size in the radial direction of the motor without protruding in the radial direction of the motor 15. can.

In FIG. 6a, the motor control device 10 further includes a cover 11 that covers the circuit board 13. The clip terminal 16 is fixed to the circuit board 13 by a terminal support portion 11p made of an insulating resin provided inside the cover 11.

Since the clip terminal 16 can be insulated from the motor case 15c by the terminal support portion 11p made of an insulating resin, it is possible to avoid a short circuit between the coil winding 15w of the motor 15 and the cover 11, the motor housing 19, and the motor case 15c. Further, since the clip terminal 16 is fixed to the circuit board 13, the connection reliability can be improved.

Also in FIG. 6b, the motor control device 10 further includes a cover 11 that covers the circuit board 13. The outside of the clip terminal 16 is resin-molded 16c and fixed to the circuit board 13 by the terminal support portion 11p of the cover 11.

Since the clip terminal 16 is a resin mold 16c, it is possible to avoid a short circuit between the coil winding 15w of the motor 15, the cover 11, the motor housing 19, and the motor case 15c. Since the clip terminal 16 is a resin mold 16c, the cover 11 may be made of metal or resin. Further, since the clip terminal 16 is fixed to the circuit board 13, the connection reliability can be improved.

The circuit board 13, the clip terminal 16, and the coil winding 15w of the motor 15 may be fixed by clipping the circuit board 13 after assembling the coil winding 15w of the motor 15 and the clip terminal 16. Further, the motor control device 10 is integrally formed with the motor 15 and the motor housing 19 by covering the cover 11.

In FIG. 3, a copper foil surface group 14 g composed of a plurality of copper foil surfaces 14 arranged in a row is provided at one end of a square shape of the circuit board 13.

Although the circuit board 13 is a single board, it also has a board on the outer side of the projection area, so that it can be easily connected to an external signal. Further, since the copper foil surfaces 14 are arranged in a row, it is easier to connect.

FIG. 7 is a cross-sectional view showing the connection and fixing of the copper foil surface group 14 g in FIG. 3 and the clip terminal connector 12.

The motor control device 10 further includes a clip terminal connector 12 in which a plurality of clip terminals for connecting an external power supply BT and an external signal to the circuit board 13 are resin-molded. The clip terminal connector 12 is fixed to the motor housing 19 outside the projection area. Each of the terminal surfaces 12s, which is one end of the terminal of the clip terminal connector 12, is in contact with the copper foil surface 14 of the copper foil surface group 14g, and each of the terminal portions 12t, which is the other end of the terminal of the clip terminal connector 12, is It is electrically connected to an external power supply BT or an external signal, respectively.

The clip terminal connector 12 and the motor housing 19 are fixed by screws, for example, in a region where the motor case 15c is projected in the axial direction of the motor and overlaps in the axial direction of the motor.

Since the clip terminal connector 12 is fixed to the motor housing 19, the clip terminal connector 12 does not shift even when an external power supply BT or an external signal is connected to the clip terminal connector 12, so that the connection stability of a plurality of clip terminals is improved. Can be improved. Further, the external power supply BT and a plurality of external signals can be electrically connected to the circuit board 13 at once. In addition, since the clip can be connected without using solder, solder cracks can be avoided.

The external signal is a steering torque signal acquired from the torque sensor 59, a vehicle speed signal acquired from the vehicle speed sensor, an in-vehicle network signal (CAN signal), or the like.

The motor control device 10 to which the power of the external power supply BT and the external signal are supplied generates the motor control signal, and powers the coil winding 15w of the motor 15 from the inverter drive circuit (not shown) via the clip terminal 16. Supply.

FIG. 8 is a diagram showing a schematic configuration of an electric power steering device including a motor control device according to an embodiment of the present invention. In FIG. 8, the electric power steering system 50 includes a motor control device 10, a motor 15, a steering handle 52 as a steering member, a rotary shaft 53 connected to the steering handle 52, a pinion gear 56, a rack shaft 57, and the like.

The rotary shaft 53 meshes with a pinion gear 56 provided at the tip thereof. The pinion gear 56 converts the rotational movement of the rotating shaft 53 into a linear movement of the rack shaft 57, and a pair of wheels 55a, 55b provided at both ends of the rack shaft 57 at an angle corresponding to the amount of displacement of the rack shaft 57. Is steered.

The rotating shaft 53 is provided with a torque sensor 59 that detects the steering torque when the steering handle 52 is operated, and the detected steering torque is sent to the motor control device 10. The motor control device 10 generates a motor drive signal based on signals such as steering torque acquired from the torque sensor 59 and vehicle speed from a vehicle speed sensor (not shown), and outputs the signal to the motor 15.

An auxiliary torque for assisting the steering of the steering handle 52 is output from the motor 15 to which the motor drive signal is input, and the auxiliary torque is transmitted to the rotating shaft 53 via the reduction gear 54. As a result, the torque generated by the motor 15 assists the rotation of the rotating shaft 53, thereby assisting the driver in operating the steering wheel.

10 Motor control device 11 Cover 12 Clip terminal connector 13 Circuit board 14 Copper foil surface 15 Electric motor 15c Motor case 15w Coil winding 16 Clip terminal 19 Motor housing 50 Electric power steering system 52 Steering handle 53 Rotating shaft 57 Rack shaft 59 Torque sensor BT external power supply

Claims (10)

A circuit board is provided which is fixed to a motor housing on the opposite output side in the axial direction of the motor, the circuit board has a plurality of connection portions for connecting a plurality of clip terminals, and the plurality of connection portions are each. It has a copper foil surface that is in contact with the connection surfaces of the plurality of clip terminals, and the copper foil surface is formed on at least one surface of the circuit board in close proximity to the end portion of the circuit board. A motor control device in which clip terminals are electrically connected by sandwiching the plurality of connection portions. The circuit board is a single substrate having a circular shape inside a projection region in which a motor case is projected in the axial direction of a motor and a rectangular portion outside the projection region. The motor control device according to claim 1, wherein the motor control device has the plurality of connections at least at the end of the circular portion. Each of the plurality of connecting portions is composed of a notch at the end of the circular portion and the copper foil surface formed on the back side of the notch, and the copper foil surface and the notch are provided. The motor control device according to claim 2, wherein the clip terminal inserted into the motor is electrically connected to the clip terminal. The connection portion is composed of a notch at the end of the circular portion and the copper foil surface formed between the adjacent notches, and the copper foil surface and the notch and the adjacent portion thereof. The motor control device according to claim 2, wherein the clip terminal inserted into the notch portion is electrically connected. The motor control device according to claim 3 or 4, wherein the other end of the clip terminal is connected to a coil winding of each phase of the motor and is housed inside the projection region. The motor control device further includes a cover that covers the circuit board, and the clip terminal is fixed to the circuit board by a terminal support portion made of an insulating resin provided inside the cover. The motor control device according to any one of claims 5. The motor control device further includes a cover that covers the circuit board, and the outside of the clip terminal is resin-molded and fixed to the circuit board by the terminal support portion of the cover, according to claims 3 to 5. The motor control device according to any one. The motor control device according to claim 2, wherein the circuit board has a copper foil surface group composed of a plurality of copper foil surfaces arranged in a row at one end of a rectangular shape of the circuit board. The motor control device further includes a clip terminal connector in which the plurality of clip terminals for connecting an external power supply and an external signal to the circuit board are resin-molded, and the clip terminal connector is said to be outside the projection area. Each of the terminal surfaces fixed to the motor housing and one end of the clip terminal connector is in contact with the copper foil surface of the copper foil surface group, and each of the terminal portions at the other end of the clip terminal connector is The motor control device according to claim 8, which is electrically connected to the external power supply or the external signal, respectively. An electric power steering device that assists the steering wheel operation of the driver of a vehicle, etc.
A torque sensor that detects the torque generated by operating the steering wheel and
The motor control device according to any one of claims 1 to 9,
An electric power steering device including the motor driven by the motor control device based on the torque detected by the torque sensor.

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