Motor control device, electric power steering device, and vehicle

Abstract

This motor control device is configured so as to be integrated with an electric motor that is rotationally driven, the motor control device comprising: a motor drive circuit in which a plurality of switching elements for controlling the electric current of the electric motor are mounted; a motor control circuit that generates a drive signal for driving the switching elements, and controls driving of the electric motor; and one circuit board that has a first circuit region that forms the motor drive circuit, and a second circuit region that forms the motor control circuit. The first circuit region is positioned on the circuit board in the direction of the rotary shaft of the electric motor, the second circuit region is positioned on the circuit board set apart from the first circuit region in the radial direction, and the circuit board has a ground through-hole for a ground line and an electric power supply through-hole for an electric power supply end line for supplying electric power to the motor drive circuit and the motor control circuit, said through-holes being positioned at a boundary portion between the first circuit region and the second circuit region.

Description

Motor control device, electric power steering device, and vehicle

[0001] The present disclosure relates to a motor control device, an electric power steering device, and a vehicle.

[0002] Electric power steering devices installed in vehicles such as automobiles include a motor control device that integrates an electric motor that assists steering of the steering wheel and a controller that controls the electric motor. In order to reduce the size of such motor control devices and improve their resistance to electromagnetic noise, a known technology is to implement a motor drive circuit that drives the motor and a motor control circuit that controls the electric motor on a single board, and to separate the board area where the motor drive circuit is mounted from the board area where the motor control circuit is mounted with respect to the ground pattern of the board (see, for example, Patent Document 1).

[0003] JP 2019-80471 A

[0004] However, in the conventional motor control devices described above, for example, the ground pattern length in the area where the motor drive circuit is mounted is long, making it easy for switching noise to be superimposed on other signals. Also, in conventional motor control devices, the area where the motor drive circuit is mounted and the area where the motor control circuit is mounted are adjacent and run side by side, which can cause electromagnetic noise generated when the electric motor is driven to propagate to the area where the motor control circuit is mounted due to spatial coupling, potentially affecting operation.

[0005] The present disclosure has been made to solve the above problems, and its purpose is to provide a motor control device, an electric power steering device, and a vehicle that can achieve compactness while further suppressing the effects of superimposed electromagnetic noise.

[0006] In order to solve the above problems, one aspect of the present disclosure is a motor control device that is integrated with a rotationally driven electric motor, and includes: a motor drive circuit equipped with a plurality of switching elements that control current through the electric motor; a motor control circuit that generates drive signals for driving the switching elements and controls the drive of the electric motor; and a circuit board having a first circuit area that forms the motor drive circuit and a second circuit area that forms the motor control circuit, wherein the first circuit area is arranged on the circuit board toward the rotation axis of the electric motor, and the second circuit area is arranged on the circuit board radially separated from the first circuit area, and the circuit board has a power supply through hole for a power supply terminal line that supplies power to the motor drive circuit and the motor control circuit and a ground through hole for a ground line, which are arranged at the boundary between the first circuit area and the second circuit area.

[0007] Furthermore, one aspect of the present disclosure is an electric power steering device comprising the motor control device described above, an electric motor that assists steering of a steering wheel, and a torque sensor that detects steering torque due to steering of the steering wheel, wherein the motor control device controls the drive of the electric motor in accordance with the steering torque detected by the torque sensor.

[0008] Another aspect of the present disclosure is a vehicle including the electric power steering device described above.

[0009] According to the present disclosure, it is possible to achieve miniaturization while further suppressing the effects of superimposed electromagnetic noise.

[0010] 1 is a block diagram showing an example of a motor control device according to a first embodiment. FIG. 2 is a configuration diagram showing an example of a motor control device according to the first embodiment. FIG. 3 is a configuration diagram showing an example of a circuit board of the motor control device according to the first embodiment. FIG. 4 is a diagram showing an example of a circuit wiring pattern of the circuit board in the first embodiment. FIG. 5 is a diagram explaining an example of a power supply and an external signal flow on the circuit board in the first embodiment. FIG. 6 is a block diagram showing an example of a motor control device according to a second embodiment. FIG. 7 is a block diagram showing an example of a motor control device according to a third embodiment. FIG. 8 is a block diagram showing an example of a motor control device according to a fourth embodiment. FIG. 9 is a configuration diagram showing an example of a front surface of the circuit board of the motor control device according to the fourth embodiment. FIG. 10 is a configuration diagram showing an example of a back surface of the circuit board of the motor control device according to the fourth embodiment. FIG. 11 is a block diagram showing an example of a motor control device according to a fifth embodiment. FIG. 12 is a configuration diagram showing an example of a circuit board of the motor control device according to the fifth embodiment. FIG. 13 is a schematic configuration diagram of an electric power steering device and a vehicle according to a sixth embodiment.

[0011] A motor control device, an electric power steering device, and a vehicle according to an embodiment of the present disclosure will be described below with reference to the drawings.

[0012] [First embodiment] Fig. 1 is a block diagram showing an example of a motor control device 1 according to a first embodiment. Fig. 2 is an exploded perspective view showing an example of the configuration of the motor control device 1 according to the first embodiment.

[0013] As shown in Fig. 1, the motor control device 1 is a control device that drives an electric motor 3 (an example of a motor) based on power supplied from a battery 2. The motor control device 1 includes a motor control circuit 24 and a motor drive circuit 25. In this embodiment, an example will be described in which the motor control device 1 controls the electric motor 3 using two systems of motor drive signals.

[0014] The motor drive circuit 25 is equipped with multiple switching elements (Q1 to Q18) that control the current of the electric motor 3, and outputs two systems of motor drive signals to the electric motor 3 via motor terminal through holes (15 to 20).

[0015] The motor drive circuit 25 includes a plurality of switching elements (Q1 to Q18), which are, for example, N-channel MOS (Metal-Oxide-Semiconductor) field effect transistors (NMOSFETs).

[0016] Switching elements Q1 to Q9 constitute an inverter circuit that generates a first system of motor drive signals (U-phase signal, V-phase signal, W-phase signal). The first system of motor drive signals (U-phase signal, V-phase signal, W-phase signal) are supplied to electric motor 3 via motor terminal through holes (15 to 17).

[0017] Switching elements Q10 to Q18 also form an inverter circuit that generates second-system motor drive signals (U-phase signal, V-phase signal, W-phase signal), which are supplied to electric motor 3 via motor terminal through-holes (18 to 20).

[0018] The electric motor 3 is, for example, a three-phase motor that is driven to rotate, and as described above, is driven by two systems of motor drive signals (U-phase signal, V-phase signal, and W-phase signal).

[0019] The motor control circuit 24 generates drive signals for driving the switching elements (Q1 to Q18) of the motor drive circuit 25, and controls the drive of the electric motor 3. The motor control circuit 24 operates using DC power supplied from the battery 2 via a power supply through hole 22 (power supply terminal) and a ground through hole 23 (ground terminal). The motor control circuit 24 also communicates with the outside via input / output through holes (9, 10), which are input / output terminals for external signals, and controls the drive of the electric motor 3 based on information communicated via the input / output through holes (9, 10).

[0020] The motor control circuit 24 includes FET drivers (11-1, 11-2), a microcomputer 12, and a constant voltage circuit 14. The FET drivers (11-1, 11-2) are an example of a switching element driver that generates drive signals to drive the switching elements (Q1 to Q18).

[0021] The FET driver 11-1 generates a drive signal for driving the switching elements (Q1 to Q9) of the first system. The FET driver 11-1 outputs the drive signal for driving the switching elements (Q1 to Q9) to the motor drive circuit 25 based on the control signal output by the microcomputer 12.

[0022] The FET driver 11-2 generates a drive signal for driving the switching elements (Q10 to Q18) of the second system. The FET driver 11-2 outputs the drive signal for driving the switching elements (Q10 to Q18) to the motor drive circuit 25 based on the control signal output by the microcomputer 12.

[0023] In this embodiment, the FET driver 11-1 and the FET driver 11-2 have the same configuration, and when simply referring to the FET driver provided in the motor control device 1 or when no particular distinction is made, the FET driver 11-1 or the FET driver 11-2 will be described as the FET driver 11.

[0024] The microcomputer 12 is, for example, a microcontroller including a CPU (Central Processing Unit), and controls the driving of the electric motor 3. Based on information input via the input / output through-holes (9, 10), the microcomputer 12 outputs control signals for controlling the driving of the electric motor 3 to the FET drivers (11-1, 11-2). In addition, in response to an external request, the microcomputer 12 outputs various pieces of information acquired or generated by the microcomputer 12 to the outside via the input / output through-holes (9, 10).

[0025] The constant voltage circuit 14 is a regulator circuit that generates a constant voltage from the power supply supplied from, for example, the battery 2. The constant voltage circuit 14 converts the DC power supplied from the battery 2 via the power supply through hole 22 and the ground through hole 23 into a constant voltage and supplies it as an operating power source for the microcomputer 12 and the FET drivers (11-1, 11-2).

[0026] The battery 2 is, for example, a lead storage battery, and supplies power to operate the motor control device 1 .

[0027] 2, the motor control device 1 is configured as an integral part of the electric motor 3, and includes a connector 21, a conductive cover 26, and a circuit board PB. The electric motor 3, the circuit board PB, the connector 21, and the conductive cover 26 are arranged in the axial direction of the electric motor 3, in that order, moving away from the electric motor 3. Here, the axial direction refers to the direction of the rotational axis of the electric motor 3, and is a direction perpendicular to the main surface of the circuit board PB (thickness direction of the circuit board PB).

[0028] The electric motor 3 is equipped with windings, motor terminals for passing current through the windings, a rotor that rotates when current flows through the windings, and magnets necessary for detecting the relative angle of the electric motor 3, and these are all covered by a frame 4.

[0029] The electric motor 3 covered by the frame 4 and the circuit board PB are fixed together with screws 27. The conductive cover 26 is made of a conductive material and is disposed on the frame 4 so as to cover the circuit board PB. A connector 21 is disposed on the upper part of the conductive cover 26.

[0030] The connector 21 is used for power supply from the battery 2 and for communication of external signals. A power supply through-hole 22, a ground through-hole 23, and input / output through-holes (9, 10) are connected to the connector 21. The connector 21 has terminals for the positive potential and ground potential of the battery 2, which are electrically connected to the power supply through-hole 22 and the ground through-hole 23 on the circuit board 8, respectively.

[0031] The circuit board PB is a board on which electronic circuits are mounted, and is fixed with screws 27 so that the main surface of the circuit board PB is perpendicular to the axial direction of the electric motor 3. Here, the main surface of the circuit board PB is the surface on which the electronic circuits are mounted, and is the surface in the radial direction of the electric motor 3. The thickness direction of the circuit board PB is the axial direction of the electric motor 3.

[0032] The electric motor 3, circuit board PB, connector 21, and conductive cover 26 are arranged in the axial direction of the electric motor 3 in the order of electric motor 3, circuit board PB, connector 21, and conductive cover 26, moving away from the electric motor 3. It is also desirable that the connector 21 has openings on the main surface of the circuit board PB directly above the power supply through-holes 22 and the ground through-holes 23, or be located on the motor control circuit area A2 side.

[0033] The circuit board PB is a single board including a motor drive circuit area A1 (first circuit area) and a motor control circuit area A2 (second circuit area). The motor drive circuit area A1 (first circuit area) is the area where the motor drive circuit 25 shown in Figure 1 is formed, and where switching elements (Q10 to Q18) and the like are mounted.

[0034] The motor drive circuit area A1 is arranged on the circuit board PB in the direction of the rotational axis of the electric motor 3. The motor drive circuit area A1 is arranged in close proximity to the direction of the rotational axis of the portion of the frame 4 that houses the windings, motor terminals, rotor, magnet, etc. of the electric motor 3. Here, heat generated by losses in the multiple switching elements (Q10 to Q18) themselves is dissipated to the electric motor 3, which is covered by the frame 4.

[0035] The motor control circuit area A2 (second circuit area) is an area where the motor control circuit 24 shown in FIG. 1 is formed, and where, for example, the FET driver 11 and the like are mounted. The motor control circuit area A2 is located on the circuit board PB, radially separated from the motor drive circuit area A1. In other words, the motor control circuit area A2 is located at a position separated from the portion of the frame 4 where the windings, motor terminals, rotor, magnet, etc. of the electric motor 3 are stored.

[0036] The circuit board PB also has a power supply through hole 22 and a ground through hole 23. The power supply through hole 22 and the ground through hole 23 are arranged between the motor drive circuit area A1 and the motor control circuit area A2 (for example, at the boundary portion).

[0037] The detailed configuration of the circuit board PB will now be described with reference to Fig. 3. Fig. 3 is a configuration diagram showing an example of the circuit board of the motor control device according to this embodiment.

[0038] As shown in FIG. 3, the circuit board PB has a motor drive circuit area A1, a motor control circuit area A2, a power supply through hole 22, and a ground through hole 23.

[0039] In FIG. 3, coordinates parallel to the main surface (XY plane) of the circuit board PB are defined as the X-axis and Y-axis, and the thickness direction of the circuit board PB (axial direction of the electric motor 3) is defined as the Z-axis.

[0040] The power supply through hole 22 and the ground through hole 23 are configured, for example, by arranging a plurality of through holes in a straight line, and it is desirable that each through hole has the same Y-axis coordinate, and the through holes are aligned so that their X-coordinates are different.

[0041] The circuit board PB has through holes (18-20) for motor terminals in the motor drive circuit area A1, and switching elements (Q10-Q18) that constitute the motor drive circuit 25 are mounted in the motor drive circuit area A1.

[0042] The motor terminal through holes (18 to 20) are arranged so as to coincide with the positions of the motor terminals of the electric motor 3 when the circuit board PB is fixed to the frame 4, and are electrically connectable thereto.

[0043] On the circuit board PB, the switching elements (Q10 to Q18) mounted in the motor drive circuit area A1 are disposed above the electric motor 3 in the axial direction (Z-axis direction).

[0044] In addition, the circuit board PB has input / output through holes (9, 10) in the motor control circuit area A2, and the motor control circuit area A2 is equipped with FET drivers (11-1, 11-2), a microcomputer 12, and a constant voltage circuit 14 that constitute the motor control circuit 24.

[0045] The input / output through holes (9, 10) are arranged at the position on the circuit board PB farthest from the motor drive circuit 25 and the electric motor 3. The input / output through holes (9, 10) are, for example, configured by arranging a plurality of through holes in a straight line, and it is desirable that each through hole has the same Y-axis coordinate, but are aligned so that their X-coordinates are different.

[0046] The power supply through-hole 22 is a through-pole for a power supply line that supplies power to the motor drive circuit 25 and the motor control circuit 24, and the ground through-hole 23 is a through-hole for a ground line.

[0047] The power supply line and the ground line are connected to the motor drive circuit 25 and the motor control circuit 24 by a power supply pattern (wiring pattern). At least one of the power supply line and the ground line is separated immediately near the power feed through hole 22 or the ground through hole 23. The power supply line may be separated by the power feed through hole 22 and connected to the motor drive circuit 25 and the motor control circuit 24, respectively. The ground line may be separated by the ground through hole 23 and connected to the motor drive circuit 25 and the motor control circuit 24, respectively.

[0048] Here, the power supply pattern (wiring pattern) connected to the power supply through-hole 22 and the ground through-hole 23 will be described with reference to Fig. 4. Fig. 4 is a diagram showing an example of a circuit wiring pattern of the circuit board PB in this embodiment.

[0049] 4, power supply wiring patterns (L22-1, L22-2) which are power supply patterns for power supply lines are provided for each of the motor control circuit 24 and the motor drive circuit 25. In addition, ground wiring patterns (L23-1, L23-2) which are power supply patterns for ground lines are provided for each of the motor control circuit 24 and the motor drive circuit 25.

[0050] The ground wiring pattern L23-1 for the motor control circuit 24 is wired from the ground through-hole 23 toward the motor control circuit area A2, and the ground wiring pattern L23-2 for the motor drive circuit 25 is wired from the ground through-hole 23 toward the motor drive circuit area A1. In this way, the ground lines are separated by the ground through-hole 23 through the ground wiring patterns (L23-1, L23-2) and connected to the motor drive circuit 25 and the motor control circuit 24, respectively.

[0051] Furthermore, the power supply wiring pattern L22-1 for the motor control circuit 24 is routed from the power supply through hole 22 toward the motor control circuit area A2, and the power supply wiring pattern L22-2 for the motor drive circuit 25 is routed from the power supply through hole 22 toward the motor drive circuit area A1. In this way, the power supply lines are separated by the power supply through hole 22 and connected to the motor drive circuit 25 and the motor control circuit 24 by the power supply wiring patterns (L22-1, L22-2).

[0052] Next, the flow of power supply and external signals to the circuit board PB in this embodiment will be described with reference to Fig. 5. Fig. 5 is a diagram illustrating an example of the flow of power supply and external signals to the circuit board PB in this embodiment.

[0053] 5, solid arrows indicate the flow of power supply, and dashed arrows indicate the flow of signals such as external signals. As shown in Fig. 5, the flow of power supply on the circuit board PB is as follows: first, in the power supply to the motor control circuit 24, power is supplied from the power supply through hole 22 to the constant voltage circuit 14, and the constant voltage circuit 14 supplies the generated constant voltage power to the microcomputer 12 and the FET drivers (11-1, 11-2).

[0054] In addition, in the power supply to the motor control circuit 24, the ground through-hole 23 is connected to the ground lines of each component of the motor control circuit 24. In the motor control circuit 24, external signals are connected to the microcomputer 12 via the input / output through-holes (9, 10), and the microcomputer 12 outputs control signals (drive instructions) for driving the switching elements (Q10 to Q18) to the FET drivers (11-1, 11-2) via the input / output through-holes (9, 10) based on, for example, vehicle information from the outside.

[0055] The signal lines for the control signals (drive instructions) output by the microcomputer 12 are connected from the microcomputer 12 to the FET drivers (11-1, 11-2), respectively. The FET drivers (11-1, 11-2) also output drive signals for the switching elements (Q10 to Q18) to the switching elements (Q10 to Q18).

[0056] The signal lines of the drive signals output by the FET drivers (11-1, 11-2) are connected to the control terminals (gate terminals) of the switching elements (Q10 to Q18) in the motor drive circuit area A1.

[0057] Furthermore, in the motor control circuit region A2 of the circuit board PB, the input / output through holes (9, 10), microcomputer 12, and FET drivers (11-1, 11-2) are preferably mounted in the above-mentioned order, starting from the end of the board farthest from the motor drive circuit region A1 and moving toward the motor drive circuit region A1. That is, the input / output through holes (9, 10), microcomputer 12, and FET drivers (11-1, 11-2) are arranged in this order toward the motor drive circuit region A1. The input / output through holes (9, 10) are arranged at least at the end of the circuit board PB and in the motor control circuit region A2.

[0058] Furthermore, since the constant voltage circuit 14 supplies voltage from the vehicle battery 2 and is connected to the power supply through hole 22 and the ground through hole 23, it is placed in the motor drive circuit area A2 so that the microcontroller 12, FET drivers (11-1, 11-2), etc. are not present between the constant voltage circuit 14 and the power supply through hole 22 or the ground through hole 23.

[0059] Furthermore, since the output of the constant voltage circuit 14 is supplied to the microcontroller 12 and the FET drivers (11-1, 11-2), the mounting position of the constant voltage circuit 14 must be within the motor control circuit area A2 and must be located in an area other than the following (1) to (3).

[0060] (1) Between the input / output through holes (9, 10) and the microcomputer 12. (2) Between the microcomputer 12 and the FET drivers (11-1, 11-2). (3) Between the FET drivers (11-1, 11-2) and the switching elements (Q10 to Q18).

[0061] By arranging the input / output through holes (9, 10), the microcomputer 12, the FET drivers (11-1, 11-2), and the constant voltage circuit 14 so as to satisfy the above-mentioned conditions, the board pattern from the input / output through holes (9, 10) to the signal lines of the drive signals for the switching elements (Q10 to Q18) can be connected in the shortest possible manner.

[0062] As described above, the motor control device 1 according to this embodiment is a motor control device integrated with the electric motor 3 that rotates and is equipped with a motor drive circuit 25, a motor control circuit 24, and a circuit board PB. The motor drive circuit 25 is equipped with multiple switching elements (Q1 to Q18) that control the current of the electric motor 3. The motor control circuit 24 generates drive signals for driving the switching elements (Q1 to Q18) and controls the driving of the electric motor 3. The circuit board PB is a single board that has a motor drive circuit area A1 (first circuit area) that forms the motor drive circuit 25 and a motor control circuit area A2 (second circuit area) that forms the motor control circuit 24. The motor drive circuit area A1 is disposed on the circuit board PB in the direction of the rotational axis of the electric motor 3. The circuit board PB also has a power supply through hole 22 for a power supply line that supplies power to the motor drive circuit 25 and the motor control circuit 24 and a ground through hole 23 for a ground line, disposed between the motor drive circuit area A1 and the motor control circuit area A2 (e.g., at the boundary between them).

[0063] As a result, the motor control device 1 according to this embodiment can prevent common impedance on the board pattern by providing a power supply through hole 22 for supplying power from the battery 2 and a ground through hole 23 between (e.g., the boundary between) the motor drive circuit area A1 and the motor control circuit area A2 arranged on the circuit board PB. This makes it possible for the motor control device 1 according to this embodiment to prevent electromagnetic noise generated in the motor drive circuit area A1 from being superimposed on the power supply wiring and ground wiring of the motor control circuit area A2. Furthermore, because the motor control device 1 according to this embodiment is configured integrally with the electric motor 3, it can be made smaller. Therefore, the motor control device 1 according to this embodiment can further suppress the effects of superimposed electromagnetic noise while achieving a smaller size.

[0064] In this embodiment, the power supply line and the ground line are connected to the motor drive circuit 25 and the motor control circuit 24, respectively. At least one of the power supply line and the ground line is separated immediately adjacent to the power feed through hole 22 or the ground through hole 23.

[0065] As a result, in the motor control device 1 according to this embodiment, either the power supply lines or the ground lines of the motor drive circuit area A1 and the motor control circuit area A2 are not shared on the board, but are shared by the power feed through holes 22 or the ground through holes 23, making it possible to design an optimal power supply pattern for each of the two areas and reducing the size of the motor control device 1. Furthermore, the motor control device 1 according to this embodiment can prevent electromagnetic noise generated in one area from being superimposed on the wiring patterns of the power supply lines and ground lines of the other area, thereby improving noise resistance.

[0066] In addition, in this embodiment, the power supply line may be separated by a power supply through hole 22 and connected to the motor drive circuit 25 and the motor control circuit 24, respectively, and the ground line may be separated by a ground through hole 23 and connected to the motor drive circuit 25 and the motor control circuit 24, respectively.

[0067] As a result, in the motor control device 1 according to this embodiment, the connection between the power supply line and the ground line is separated between the motor drive circuit 25 and the motor control circuit 24 by the power supply through hole 22 and the ground through hole 23, so that the effects of electromagnetic noise can be further suppressed between the motor drive circuit 25 and the motor control circuit 24.

[0068] In this embodiment, the circuit board PB also has input / output through holes (9, 10) for external signals. The input / output through holes (9, 10) are arranged in the motor control circuit area A2.

[0069] As a result, by providing the input / output through holes (9, 10) in the motor control circuit area A2, the motor control device 1 according to this embodiment can realize a pattern design that is not affected by switching noise generated by the motor drive circuit 25. Therefore, the motor control device 1 according to this embodiment can suppress the superposition of electromagnetic noise onto external signal lines while the motor is being driven.

[0070] In this embodiment, the motor control circuit 24 includes a microcomputer 12, an FET driver 11 (switching element drive unit), and a constant voltage circuit 14. The microcomputer 12 (microcomputer) controls the drive of the electric motor 3. The FET driver 11 (switching element drive unit) generates drive signals that drive the switching elements (Q1 to Q18). The constant voltage circuit 14 generates a constant voltage that is supplied to the microcomputer 12 and the FET driver 11. In the motor control circuit area A2 of the circuit board PB, input / output through holes (9, 10), the microcomputer 12, and the FET driver 11 are arranged in this order toward the motor drive circuit area A1.

[0071] This allows the motor control device 1 according to this embodiment to be connected so that the wiring pattern from the input / output through holes (9, 10) to the drive signals of the switching elements (Q1 to Q18) is the shortest. Therefore, the motor control device 1 according to this embodiment can be wired so that the power supply path to the electronic components mounted on the circuit board PB is also the shortest, allowing the motor control device 1 to be made smaller while still further improving its noise resistance.

[0072] The motor control device 1 according to this embodiment also includes a connector 21. The connector 21 is arranged on the main surface of the circuit board PB so that its openings are located directly above the power supply through-holes 22 and the ground through-holes 23, or on the motor control circuit area A2 side.

[0073] As a result, the motor control device 1 according to this embodiment can suppress spatial superposition of electromagnetic noise generated in the motor drive circuit 25 on the connection lines (power supply line and ground line) to the battery 2 .

[0074] Second Embodiment Next, a motor control device 1a according to a second embodiment will be described with reference to the drawings.

[0075] In recent years, when a motor control device is applied to, for example, electric power steering, system redundancy is adopted in order to reduce the failure rate that leads to an assist disabled mode due to a hardware random failure, along with the expansion of autonomous vehicles. In the first embodiment described above, an example in which control is performed using two systems as system redundancy was explained, but in this embodiment, a modified example in which the motor control device is applied to a non-redundant system that does not implement redundancy will be explained.

[0076] Fig. 6 is a block diagram showing an example of a motor control device 1a according to the second embodiment. As shown in Fig. 6, the motor control device 1a is a control device that drives an electric motor 3a (an example of a motor) based on power supplied from a battery 2. The motor control device 1a includes a motor control circuit 24a and a motor drive circuit 25a.

[0077] In FIG. 6, the same components as those in FIG. 2 are denoted by the same reference numerals, and the description thereof will be omitted.

[0078] The electric motor 3a is, for example, a three-phase motor that is driven to rotate, and is driven by a single system of motor drive signals (U-phase signal, V-phase signal, W-phase signal) without redundancy.

[0079] The motor drive circuit 25a is equipped with multiple switching elements (Q1 to Q9) that control the current of the electric motor 3a, and generates a motor drive signal that drives the electric motor 3a. The motor drive circuit 25a outputs one system of motor drive signals to the electric motor 3a via the motor terminal through holes (15 to 17).

[0080] The motor control circuit 24a generates drive signals for driving the switching elements (Q1 to Q9) of the motor drive circuit 25a, and controls the driving of the electric motor 3a. The motor control circuit 24a operates using DC power supplied from the battery 2 via the power supply through-hole 22 (power supply terminal) and the ground through-hole 23 (ground terminal).

[0081] The motor control circuit 24a communicates with the outside via input / output through-holes (9, 10) that are input / output terminals for external signals, and controls the driving of the electric motor 3a based on the information communicated via the input / output through-holes (9, 10). The motor control circuit 24a includes one FET driver 11-1, a microcomputer 12, and a constant voltage circuit 14.

[0082] The configuration example of the motor control device 1a according to this embodiment is similar to the configuration example of the first embodiment shown in Fig. 2. Except for the fact that the motor drive circuit 25a is mounted in the motor drive circuit area A1 and the motor control circuit 24a is mounted in the motor control circuit area A2 on the circuit board PB, the configuration is similar to the first embodiment shown in Fig. 2, and therefore a description thereof will be omitted here.

[0083] As described above, the motor control device 1a according to this embodiment comprises a motor control circuit 24a and a motor drive circuit 25a, with the motor drive circuit 25a implemented in the motor drive circuit area A1 and the motor control circuit 24a implemented in the motor control circuit area A2.

[0084] As a result, the motor control device 1a according to this embodiment has the same effects as the first embodiment described above, and can achieve miniaturization while further suppressing the effects of superimposed electromagnetic noise.

[0085] Third Embodiment Next, a motor control device 1b according to a third embodiment will be described with reference to the drawings. In this embodiment, a modified example in which the microcomputer 12 and the constant voltage circuit 14 are applied to a redundant system with further redundancy will be described.

[0086] 7 is a block diagram showing an example of a motor control device 1b according to this embodiment. As shown in FIG. 7, the motor control device 1b includes a motor control circuit 24b and a motor drive circuit 25.

[0087] In FIG. 7, the same components as those in FIG. 2 are denoted by the same reference numerals, and the description thereof will be omitted.

[0088] The motor control circuit 24b generates drive signals for driving the switching elements (Q1 to Q18) of the motor drive circuit 25, and controls the driving of the electric motor 3. The motor control circuit 24b operates using DC power supplied from the battery 2 via the power supply through-hole 22 (power supply terminal) and the ground through-hole 23 (ground terminal).

[0089] The motor control circuit 24b communicates with the outside via input / output through holes (9, 10) which are input / output terminals for external signals, and controls the driving of the electric motor 3 based on the information communicated via the input / output through holes (9, 10). The motor control circuit 24b includes FET drivers (11-1, 11-2), microcomputers (12-1, 12-2), and constant voltage circuits (14-1, 14-2).

[0090] The microcomputers 12-1 and 12-2 have the same configuration as the microcomputer 12 of the first embodiment described above, and output one system of control signals. The microcomputer 12-1 outputs a control signal for controlling the drive of the electric motor 3 to the FET driver 11-1 based on information input via the input / output through holes (9, 10). The microcomputer 12-2 outputs a control signal for controlling the drive of the electric motor 3 to the FET driver 11-2 based on information input via the input / output through holes (9, 10).

[0091] The constant voltage circuits 14-1 and 14-2 are regulator circuits that generate a constant voltage from a power supply supplied from, for example, the battery 2, and have the same configuration as the constant voltage circuit 14 of the first embodiment described above. The constant voltage circuits 14-1 and 14-2 each output a constant voltage power supply for one system.

[0092] The constant voltage circuit 14-1 converts DC power supplied from the battery 2 via the power supply through hole 22 and the ground through hole 23 into a constant voltage, and supplies it as an operating power source for the microcomputer 12-1 and the FET driver 11-1.

[0093] Furthermore, the constant voltage circuit 14-2 converts DC power supplied from the battery 2 via the power supply through hole 22 and the ground through hole 23 into a constant voltage, and supplies it as an operating power source for the microcomputer 12-2 and the FET driver 11-2.

[0094] The configuration example of the motor control device 1b according to this embodiment is similar to the configuration example of the first embodiment shown in Fig. 2. Except for the fact that the motor drive circuit 25 is mounted in the motor drive circuit area A1 and the motor control circuit 24b is mounted in the motor control circuit area A2 on the circuit board PB, the configuration is similar to the first embodiment shown in Fig. 2, and therefore a description thereof will be omitted here.

[0095] As described above, the motor control device 1b according to this embodiment comprises a motor control circuit 24b and a motor drive circuit 25, with the motor drive circuit 25 implemented in the motor drive circuit area A1 and the motor control circuit 24b implemented in the motor control circuit area A2.

[0096] As a result, the motor control device 1b according to this embodiment has the same effects as the first embodiment described above, and can further reduce the effects of superimposed electromagnetic noise while achieving a smaller size. Furthermore, the motor control device 1b according to this embodiment further enhances the reliability of the system using the electric motor 3 by further increasing the redundancy of the microcomputer 12 and the constant voltage circuit 14.

[0097] Next, a motor control device 1c according to a fourth embodiment will be described with reference to the drawings. In this embodiment, a modification of the motor control device 1b according to the third embodiment is described in which redundancy is further provided from the battery 2 to form two systems.

[0098] 8 is a block diagram showing an example of a motor control device 1c according to this embodiment. As shown in Fig. 8, the motor control device 1c includes motor control circuits (24a-1, 24a-2), motor drive circuits (25a-1, 25a-2), input / output through holes (9-1, 9-2, 10-1, 10-2), power supply through holes (22-1, 22-2), ground through holes (23-1, 23-2), and motor terminal through holes (15-17).

[0099] In FIG. 8, the same components as those in FIG. 6 are denoted by the same reference numerals, and the description thereof will be omitted.

[0100] The motor drive circuit 25a-1 has the same function as the motor drive circuit 25a shown in Figure 6 above, and drives the switching elements (Q1 to Q9) of the first system. The motor drive circuit 25a-1 is equipped with multiple switching elements (Q1 to Q9) that control the current of the electric motor 3, and generates a motor drive signal that drives the electric motor 3. The motor drive circuit 25a-1 outputs the motor drive signal of the first system to the electric motor 3 via the motor terminal through holes (15 to 17).

[0101] The motor drive circuit 25a-2 has the same function as the motor drive circuit 25a shown in Figure 6 above, and drives the switching elements (Q10 to Q18) of the second system. The motor drive circuit 25a-2 is equipped with multiple switching elements (Q10 to Q18) that control the current of the electric motor 3, and generates a motor drive signal that drives the electric motor 3. The motor drive circuit 25a-2 outputs the motor drive signal of the second system to the electric motor 3 via the motor terminal through holes (18 to 20).

[0102] The motor control circuit 24a-1 has the same functions as the motor control circuit 24a shown in Figure 6 described above, and controls the driving of the motor of the first system. The motor control circuit 24a-1 generates drive signals for driving the switching elements (Q1 to Q9) of the motor drive circuit 25a-1 of the first system, and controls the driving of the electric motor 3. The motor control circuit 24a-1 operates using DC power supplied from the battery 2 via the power supply through-hole 22-1 (power supply terminal) and the ground through-hole 23-1 (ground terminal).

[0103] The motor control circuit 24a-1 includes an FET driver 11-1, a microcomputer 12-1, and a constant voltage circuit 14-1. The microcomputer 12-1 has the same functions as the microcomputer 12, and the constant voltage circuit 14-1 has the same functions as the constant voltage circuit 14.

[0104] The motor control circuit 24a-2 has the same functions as the motor control circuit 24a shown in Figure 6 described above, and controls the drive of the motor of the second system. The motor control circuit 24a-2 generates drive signals for driving the switching elements (Q10 to Q18) of the motor drive circuit 25a-2 of the second system, and controls the drive of the electric motor 3. The motor control circuit 24a-2 operates using DC power supplied from the battery 2 via the power supply through hole 22-2 (power supply terminal) and the ground through hole 23-2 (ground terminal).

[0105] The motor control circuit 24a-2 includes an FET driver 11-2, a microcomputer 12-2, and a constant voltage circuit 14-2. The microcomputer 12-2 has the same functions as the microcomputer 12, and the constant voltage circuit 14-2 has the same functions as the constant voltage circuit 14.

[0106] The motor control device 1c also includes a circuit board PBa. Electronic components are mounted on both the front and back surfaces of the circuit board PBa in a plane (XY axis plane). An example of the configuration of the circuit board PBa will now be described with reference to FIGS. 9A and 9B .

[0107] 9A is a configuration diagram showing an example of the front surface of the circuit board PBa of the motor control device 1c according to this embodiment. Here, the front surface of the circuit board PBa refers to the surface on the conductive cover 26 side, and the back surface of the circuit board PBa refers to the surface on the frame 4 side.

[0108] As shown in FIG. 9A, a motor drive circuit area A1, a motor control circuit area A2, power supply through holes (22-1, 22-2), and ground through holes (23-1, 23-2) are arranged on the surface of the circuit board PBa.

[0109] Switching elements (Q10 to Q18) of the motor drive circuits (25a-1, 25a-2) are arranged in the motor drive circuit area A1 on the surface of the circuit board PBa, and the first system motor control circuit 24a-1 and input / output through holes (9-1, 9-2, 10-1, 10-2) are arranged in the motor control circuit area A2 on the surface of the circuit board PBa, and an FET driver 11-1, a microcomputer 12-1, and a constant voltage circuit 14-1 are mounted.

[0110] The power supply through-hole (22-1) and the ground through-hole (23-1) supply operating power to the first motor control circuit 24a-1 and the motor drive circuit 25a-1. The input / output through-holes (9-1, 10-1) output input / output signals from the outside to the first motor control circuit 24a-1.

[0111] 9B is a diagram showing an example of the back surface of the circuit board PBa of the motor control device 1c according to this embodiment. As shown in FIG. 9B, the back surface of the circuit board PBa is provided with a motor control circuit area A2, power supply through holes (22-1, 22-2), and ground through holes (23-1, 23-2).

[0112] In the motor control circuit area A2 on the back surface of the circuit board PBa, a second system motor control circuit 24a-2 and input / output through holes (9-1, 9-2, 10-1, 10-2) are arranged, and a FET driver 11-2, a microcomputer 12-2, and a constant voltage circuit 14-2 are mounted.

[0113] The power supply through-hole (22-2) and the ground through-hole (23-2) supply operating power to the second system motor control circuit 24a-2 and the motor drive circuit 25a-2. The input / output through-holes (9-2, 10-2) output input / output signals from the outside to the first system motor control circuit 24a-2.

[0114] Furthermore, a configuration example of a motor control device 1c according to this embodiment is similar to the configuration example of the first embodiment shown in Fig. 2. Except for the fact that the circuit board PB is replaced with a circuit board PBa, it is similar to the first embodiment shown in Fig. 2, and therefore a description thereof will be omitted here.

[0115] As described above, the motor control device 1c according to this embodiment comprises motor control circuits (24a-1, 24a-2) and motor drive circuits (25a-1, 25a-2), with the motor drive circuits (25a-1, 25a-2) implemented in the motor drive circuit area A1 and the motor control circuits (24a-1, 24a-2) implemented in the motor control circuit area A2.

[0116] As a result, the motor control device 1c according to this embodiment has the same effects as the first embodiment described above, and can achieve miniaturization while further suppressing the effects of superimposed electromagnetic noise.

[0117] The motor control device 1c also includes a circuit board PBa, which has electronic components mounted on both its front and back surfaces. This allows the motor control device 1c of this embodiment to effectively utilize the electronic component mounting surface of the circuit board PBa, thereby achieving even greater miniaturization.

[0118] Fifth Embodiment Next, a motor control device 1d according to a fifth embodiment will be described with reference to the drawings. In this embodiment, a modification of the first embodiment in which a noise removal filter is added will be described.

[0119] 10 is a block diagram showing an example of a motor control device 1d according to this embodiment. As shown in Fig. 10, the motor control device 1d includes a motor control circuit 24, a motor drive circuit 25, input / output through holes (9, 10), a power supply through hole 22, a ground through hole 23, motor terminal through holes (15-20), and noise suppression filters (31, 32).

[0120] 10, the same components as those in the above-described Fig. 1 are denoted by the same reference numerals, and their description will be omitted. The noise suppression filters (31, 32) are noise removal filters and are connected to the power supply line of the power supply through hole 22. The noise suppression filters (31, 32) are, for example, capacitors.

[0121] The noise suppression filter 31 is a noise suppression filter for the motor control circuit 24 , and the noise suppression filter 32 is a noise suppression filter for the motor drive circuit 25 .

[0122] An example of the arrangement of the noise suppression filters (31, 32) on the circuit board PB will now be described with reference to Fig. 11. Fig. 11 is a configuration diagram showing an example of the circuit board PB of the motor control device 1d according to this embodiment.

[0123] 11, on the circuit board PB, the noise suppression filter 31 is arranged between the power supply wiring pattern L22-1 and the ground wiring pattern L23-1 in the motor control circuit area A2, and the noise suppression filter 32 is arranged between the power supply wiring pattern L22-2 and the ground wiring pattern L23-2 in the motor drive circuit area A1.

[0124] As described above, in the motor control device 1d according to this embodiment, the motor control circuit 24, the motor drive circuit 25, the power supply through hole 22, and the ground through hole 33 are arranged on the circuit board PB in the same manner as in the first embodiment.

[0125] As a result, the motor control device 1d according to this embodiment has the same effects as the first embodiment described above, and can achieve miniaturization while further suppressing the effects of superimposed electromagnetic noise.

[0126] As shown in FIG. 11, the motor control device 1d according to this embodiment also includes a noise suppression filter 31 for the motor control circuit 24 and a noise suppression filter 32 for the motor drive circuit 25.

[0127] As a result, the motor control device 1d according to this embodiment is equipped with noise suppression filters (31, 32), which can further suppress the effects of superimposed electromagnetic noise, and can more efficiently reduce the electromagnetic noise generated in each of the motor drive circuit 25 and the motor control circuit 24.

[0128] Sixth Embodiment Next, an electric power steering device 50 and a vehicle A according to a sixth embodiment will be described with reference to the drawings.

[0129] 12 is a schematic diagram of an electric power steering device 50 according to the sixth embodiment and a vehicle A. The electric power steering device 50 includes a motor control device 1 (1a to 1d) according to any one of the first to fifth embodiments.

[0130] 13, vehicle A includes an electric power steering device 50. The electric power steering device 50 includes an electric motor 3, a motor control device 1 (1a to 1d), a torque sensor 52, a steering wheel 53, a steering shaft 54, a rack and pinion gear 55, wheels 56, and a reduction gear 57.

[0131] The steering wheel 53 is steered by the driver. The steering shaft 54 ​​is connected to the steering wheel 53 and a rack and pinion gear 55. The steering torque applied to the steering wheel 53 by the driver is transmitted to the rack and pinion gear 55 via the steering shaft 54.

[0132] The rack included in the rack-pinion gear 55 is connected to the wheels 56 via a tie rod and a knuckle arm. When steering torque is transmitted to the rack, the tie rod pushes the knuckle arm at one wheel 56, and the tie rod pulls the knuckle arm at the other wheel 56. This causes the wheels 56 to turn.

[0133] The electric motor 3 functions as a driving force source that assists the steering of the steering wheel 53. Specifically, the electric motor 3 is connected to the steering shaft 54 ​​via a reduction gear 57. The motor torque generated by the electric motor 3 is transmitted to the steering shaft 54 ​​via the reduction gear 57, reducing the steering force applied by the driver when steering.

[0134] The torque sensor 52 is attached to the steering shaft 54. The torque sensor 52 detects the steering torque applied to the steering shaft 54 ​​when the driver turns the steering wheel 53. The torque sensor 52 outputs the detected steering torque to the motor control device 1 (1a to 1d).

[0135] The motor control device 1 (1a to 1d) receives the steering torque detected by the torque sensor 52 as an input, generates a motor drive signal corresponding to the steering torque, and outputs the signal to the electric motor 3. In other words, the motor control device 1 (1a to 1d) controls the drive of the electric motor 3 according to the steering torque.

[0136] As described above, the electric power steering device 50 according to this embodiment includes the motor control device 1 (1a to 1d), the electric motor 3 that assists the steering of the steering wheel 53, and the torque sensor 52 that detects the steering torque caused by the steering of the steering wheel 53. The motor control device 1 (1a to 1d) controls the driving of the electric motor 3 in accordance with the steering torque detected by the torque sensor 52.

[0137] As a result, the electric power steering device 50 according to this embodiment achieves the same effects as the motor control device 1 (1a to 1d) described above, and can further suppress the effects of superimposed electromagnetic noise while achieving miniaturization.

[0138] Furthermore, the vehicle A according to this embodiment is equipped with an electric power steering device 50. As a result, the vehicle A according to this embodiment can achieve the same effects as the electric power steering device 50 described above, and can further suppress the effects of superimposed electromagnetic noise while achieving a smaller size.

[0139] The present disclosure is not limited to the above-described embodiments and may be modified within the scope of the present disclosure. For example, in the above-described embodiments, the switching elements (Q1 to Q18) are NMOSFETs, but the present disclosure is not limited to this and may be other types of switching elements, such as IGBTs (insulated gate bipolar transistors).

[0140] Furthermore, in each of the above embodiments, the motor control circuit 24 (24a, 24a-1, 24a-2, 24b) and the motor drive circuit 25 (25a, 25a-1, 25a-2) are not limited to the circuit configurations described in each embodiment, and may have other circuit configurations.

[0141] Furthermore, in each of the above embodiments, an example has been described in which the circuit board PB (PBa) has a rectangular shape, but this is not limited to this and the board may have other shapes, such as a round or square shape.

[0142] Furthermore, in the above embodiment, an example has been described in which the motor control device 1 (1a, 1b, 1c, 1d) is applied to an electric power steering device, but this is not limitative, and the motor control device 1 (1a, 1b, 1c, 1d) may be applied to other uses.

[0143] 1, 1a, 1b, 1c, 1d... Motor control device, 2... Battery, 3, 3a... Electric motor, 9, 9-1, 9-2, 10, 10-1, 10-2... Input / output through-holes, 11, 11-1, 11-2... FET drivers, 12, 12-1, 12-2... Microcomputer, 14, 14-1, 14-2... Constant voltage circuits, 15 to 20... Motor terminal through-holes, 21... Connector, 22, 22-1, 22-2... Power supply through-holes, 23, 23-1, 23-2... Ground through-holes, 24, 24a, 24a-1, 24a-2, 24b... Motor control circuit, 25, 2 5a, 25a-1, 25a-2...motor drive circuit, 26...conductive cover, 27...screw, 31, 32...noise suppression filter, 50...electric power steering device, 52...torque sensor, 53...steering wheel, 54...steering shaft, 55...rack and pinion gear, 56...wheel, 57...reduction gear, A...vehicle, A1...motor drive circuit area, A2...motor control circuit area, L22-1, L22-2...power supply wiring pattern, L23-1, L23-2 ground wiring pattern, PB, PBa...circuit board, Q1 to Q18...switching elements

Claims

1. A motor control device integrated with a rotationally driven electric motor, comprising: a motor drive circuit equipped with a plurality of switching elements that control the current of the electric motor; a motor control circuit that generates drive signals for driving the switching elements and controls the drive of the electric motor; and a circuit board having a first circuit area that forms the motor drive circuit and a second circuit area that forms the motor control circuit, wherein the first circuit area is arranged on the circuit board toward the rotation axis of the electric motor, and the second circuit area is arranged on the circuit board radially separated from the first circuit area, and the circuit board has a power supply through hole for a power supply line that supplies power to the motor drive circuit and the motor control circuit and a ground through hole for a ground line, arranged at the boundary between the first circuit area and the second circuit area.

2. The motor control device according to claim 1, wherein the power supply line and the ground line are connected to the motor drive circuit and the motor control circuit, respectively, and at least one of the power supply line and the ground line is separated in the immediate vicinity of the power feed through hole or the ground through hole.

3. The motor control device according to claim 2, wherein the power supply lines are separated by the power supply through-holes and connected to the motor drive circuit and the motor control circuit, respectively, and the ground lines are separated by the ground through-holes and connected to the motor drive circuit and the motor control circuit, respectively.

4. A motor control device according to any one of claims 1 to 3, wherein the circuit board has input / output through holes for external signals, and the input / output through holes are arranged in the second circuit area.

5. A motor control device according to claim 4, wherein the motor control circuit comprises a microcomputer that controls the drive of the electric motor, a switching element drive unit that generates the drive signal that drives the switching element, and a constant voltage circuit that generates a constant voltage to be supplied to the microcomputer and the switching element drive unit, and the input / output through-hole, the microcomputer, and the switching element drive unit are arranged in this order in the second circuit area of ​​the circuit board toward the first circuit area.

6. An electric power steering device comprising: a motor control device according to any one of claims 1 to 5; an electric motor that assists steering of a steering wheel; and a torque sensor that detects steering torque due to steering of the steering wheel, wherein the motor control device controls the drive of the electric motor in accordance with the steering torque detected by the torque sensor.

7. A vehicle equipped with the electric power steering device according to claim 6.

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