JP5390980B2 - Motor unit for electric power steering and electric power steering device - Google Patents

Description

  The present invention relates to an electric power steering motor unit and an electric power steering apparatus including the same.

Electric power steering system EPS (Electric Power-Steering)
System) is a torque sensor that detects steering torque, and an electric power steering motor unit that controls the output of the electric motor in accordance with a signal from the torque sensor and appropriately adjusts assist torque added to the steering torque (hereinafter referred to as motor unit). And a gear box that generates an output torque obtained by adding an assist torque to a steering torque. Such an electric power steering device drives an electric motor in accordance with a signal from a torque sensor, and gives an assist torque according to a driver's intention to operate, thereby making the operability of a steering handle provided in the vehicle comfortable. It is.

  The motor unit includes a full bridge circuit that includes a power semiconductor element and controls the electric motor by a PWM (Power Width Modulation) method, and a control board that outputs a control signal to the power semiconductor element and adjusts the output power of the full bridge circuit. An arranged motor control device is provided. Since such a motor control device includes a power semiconductor element such as a full bridge circuit, a heat radiator such as a heat sink is required. However, in order to fully demonstrate the function of the radiator, the position of the radiator of the motor control device is selected. Therefore, the motor controller is arranged at a position away from the housing of the motor unit. It was common to be done. In such a case, since the electric motor built in the motor unit and the motor control device arranged independently of the motor unit are electrically connected by the harness, the voltage drop caused by the harness and the complicated assembly work. Along with these problems, it has been pointed out that the production cost will rise.

  In view of this, Japanese Patent Application Laid-Open No. 2008-254655 (Patent Document 1) introduces an electric power steering device in which a harness between an electric motor and a control unit (a control device in claims) is omitted. Such an electric power steering apparatus includes an electric motor, a control unit that controls the electric motor, and a gear box that is connected to a drive shaft of the electric motor and generates assist torque in accordance with the operation of the electric motor. The electric motor has a motor-side contact surface that contacts the bracket of the gear box, and a motor-side terminal is provided on the motor-side contact surface. On the other hand, the control unit is provided with a control side terminal on the side surface in the longitudinal direction. The electric motor is fixed to the bracket of the gear box through the contact surface of the motor, and the control side terminal of the control unit is directly connected to the motor side terminal.

  However, in the technique of Patent Document 1, since the electric motor and the control unit are connected in the axial direction, the terminal connecting portion is disposed in the intermediate portion of the connected structure, and a large bending moment is applied to the terminal connecting portion. I will let you. Therefore, when such a device is mounted on a vehicle, a structure capable of withstanding vibration or impact is required. Therefore, it is necessary to provide a support structure in the gear box to grip the control unit, and the structure of the gear box is complicated. In addition, there arises a problem that the assembly work is complicated.

  Japanese Patent Laid-Open No. 2003-204654 (Patent Document 2) introduces an electric power steering device that avoids such a problem. The electric power steering device includes a motor (an electric motor in the claims), a cylindrical frame (a motor cover in the claims field) that houses the motor, a housing that houses a brush of the motor, and the motor. A power semiconductor element to be controlled, a control circuit unit for controlling the power semiconductor element, and a control circuit unit containing a filter circuit, the control circuit unit being disposed on a side wall of the power steering device and screwed to the housing and the frame. Thereby, the support structure of the gear box is omitted.

JP 2008-254655 A JP 2003-204654 A

  Generally, since an electric motor is fixed to a bracket formed on a gear box, a housing side that accommodates a brush or the like is a fixed end, and a frame (motor cover) side thereof is a free end. It exhibits a structure. In this case, when the vibration or impact force of the vehicle is transmitted to the electric power steering apparatus, in each structure that supports the weight on the frame (motor cover) side, the bending moment acting due to vibration or the like increases according to the weight on the frame side. It will be. Therefore, in the electric power steering apparatus having such a structure, it is preferable that the structure on the frame (motor cover) side is somewhat reduced in weight.

  However, in the technique according to Patent Document 2, since all of the control board, the power semiconductor element, and the filter circuit are accommodated in the control circuit unit, the weight of the control circuit unit becomes enormous, and the weight of the structure on the frame side. Will also increase accordingly. Therefore, in the technique of Patent Document 2, the structure of the joint portion between the housing and the frame (motor cover) must be strengthened, and there is a problem that the structure of the device is increased in size, weight, and cost. Arise. The structure of the coupling portion between the housing and the frame (motor cover) includes the fastening material such as a bolt for coupling the housing and the frame (motor cover), and the thickness and shape of the structure in the housing and the frame (motor cover). Etc.

  In addition, since a high bending moment acts on the abutment surface between the gear box bracket and the housing on the electric motor side, the structure around the bracket is required to be strengthened, and the electric power steering device is increased in size, weight, and weight. There is also a problem that it leads to cost.

  SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to provide an electric power steering motor unit and an electric power steering device that can prevent an increase in size and weight of the device and can also avoid an increase in cost.

In order to solve the above problems, the present invention has the following configuration of an electric power steering motor unit. That is, an electric motor that generates drive torque on the drive shaft in accordance with the turning operation of the built-in rotor and a power semiconductor element that outputs drive power for converting the input power and driving the electric motor is output. A power conversion unit, a power element substrate on which the power semiconductor element is mounted, a motor side bracket in which the power element substrate is accommodated, and a power distribution unit in which at least a filter circuit inserted in an electric circuit is accommodated. A motor cover that houses the electric motor, and a control device that includes a housing body fixed to a side surface of the motor cover and houses a control board that controls the power semiconductor element inside the housing body. In the motor unit for electric power steering,
The power distribution unit has an angle forming surface that forms a predetermined angle with respect to a side surface of the motor cover, and the container is fixed to the angle forming surface.

Preferably, the angle forming surface is substantially perpendicular to the side surface of the motor cover.

Preferably, the angle forming surface is offset from the position of the power element substrate toward the motor.

Preferably, the container is made of a resin material.

Preferably, the fixing part between the container and the power distribution part is waterproofed.

In the present invention, the following electric power steering device may be used. That is, the motor unit for electric power steering described above and a gear box that adds the assist torque to the steering torque according to the turning operation of the steering handle are provided.

  According to the motor unit for electric power steering according to the present invention, since the control device fixed to the side wall of the motor cover is reduced in weight, the coupling structure between the motor cover and the motor side bracket is also simplified, thereby The increase in size and weight is avoided, and at the same time, the increase in cost is prevented.

  Further, according to the electric power steering apparatus of the present invention, since the bending moment acting on the contact surface between the electric power steering motor unit and the gear box bracket is suppressed, the structure around the gear box bracket is simplified. This avoids the increase in size and weight of the apparatus, and at the same time, prevents the increase in cost.

The figure which shows the structure of the vehicle carrying the electric power steering device. The figure which shows the structure of the electric power steering apparatus which concerns on embodiment. The figure which shows the internal structure of the electric power steering apparatus which concerns on embodiment. 1 shows a circuit configuration of an electric power steering apparatus according to an embodiment. The figure which shows the structure of the motor unit for electric power steering which concerns on this Embodiment. Sectional drawing of the motor unit for electric power steering which concerns on this Embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. As shown in FIG. 1, the vehicle CAR includes a front wheel FT and a rear wheel RT provided in the chassis, and controls the yawing posture of the vehicle body by giving a steering angle to the front wheel FR. The front wheel FR is provided with a rack RCK and is steered according to the axial movement operation of the rack RCK. In recent years, vehicles employing so-called 4WS (4 Wheel Steering) in which front and rear wheels are steered according to the vehicle speed are also widely used.

  As shown in the figure, a vehicle CAR equipped with an electric power steering device (a driven device in claims) includes an in-vehicle battery BTT, a vehicle speed sensor VMU, an ECU 1 (Engine Control Unit / Electric Control Unit), a steering device HDM, and electric power. The steering device 200, an ignition relay IG, and a pinion gear box SGB are included.

  The in-vehicle battery BTT is composed of a rechargeable battery pack and outputs a voltage of about 12 to 24V. Such a battery pack does not ask the type of the battery.

  The vehicle speed sensor VMU converts information related to the vehicle speed into an electrical signal using a wheel rotation sensor or a sensor that detects a reflected wave from the road surface. In the vehicle CAR according to the present embodiment, information on the vehicle speed sensor VMU is transmitted to the ECU 1.

  The ECU is generally called an “engine control unit” for a vehicle equipped with an internal combustion engine, and is generally called an “electric control unit” for an electric vehicle. However, the present embodiment is not distinguished by these differences, and a desired signal is transmitted to the electric power steering apparatus 200 based on the speed information received from the vehicle speed VMU. In addition, the ECU 1 receives information from sensors installed in the vehicle and performs appropriate processing related to operation control of the vehicle CAR. In recent years, an ECU is provided in each sensor and can share information of each sensor with a CAN (Control Area Network). As will be described later, in the present embodiment, the electric power steering unit 100 is also equipped with an ECU for controlling the device.

  The handle device HDM is provided on the driver seat and transmits a steering torque according to the driver's steering intention to the electric power steering device 200. Further, the handle device HDM is provided with an ignition key, and when the ignition key is rotated, the ignition relay IG is switched to the ON state. In the case of an internal combustion engine, the cell motor is driven, and the electric vehicle In such a case, the control circuit for the wheel motor or the control circuit for another device is activated to switch to the standby state.

  As shown in the figure, the electric power steering apparatus 200 includes a torque sensor TS, a reduction gear box WGB, and an electric power steering motor unit 100 as main components, and the electric power steering motor unit (hereinafter referred to as a motor unit). Reference numeral 100 includes an ECU 2 and an electric motor EM as main components. The detailed configuration and operation of the electric power steering apparatus 200 and the motor unit 100 will be described later.

  In the pinion gear box SGB, the teeth formed on the rack RCK and the pinion gear fixed to the transmission shaft CSH are engaged with each other, and the rotational motion of the transmission shaft CSH is converted into the axial motion of the rack RCK. The transmission shaft CSH is appropriately provided with a universal joint to smoothly transmit the output torque applied from the electric power steering device 200 to the pinion gear box SGB.

  In the vehicle CAR having such a configuration, when the steering device HDM is steered by the driver, the ECU 2 drives the electric motor EM based on the signal from the torque sensor TS and the speed information from the ECU 1, thereby In the steering device 200, an assist torque is added to the steering torque by the driver, and an output torque corresponding to the steering intention of the driver is generated. At this time, in the vehicle CAR, the output torque gives an axial force to the rack RCK, so that a steering angle according to the steering intention of the driver is given to the front wheels FT regardless of the state of the load applied to the tires. This reduces the burden of handle operation by the user and improves operability.

  FIG. 2 shows a column type electric power steering apparatus according to the present embodiment. Such an electric power steering apparatus 200 is fixed to a main body portion including a shaft 210, a shaft case 220, a torque sensor housing portion 230, a signal terminal 240, and a gear box 250 (a reduction gear box WGB in FIG. 1). The motor unit 100 is comprised. Hereinafter, when the axial center of the shaft 210 is the axial direction, the side on which the gear box 250 in the axial direction is arranged is referred to as a rear side DR, and the opposite side of the rear side DR is referred to as a front side DF. Note that a pinion gear box PGW is connected to the front side DF via a transmission shaft CSH, and a handle device HDM is connected to the rear side DR.

  The shaft 210 forms a cylindrical bar, and includes a front side shaft 211 and a rear side shaft 212 and a torsion bar (not shown). The front shaft 211 has a male screw 211a and a spline 211b, and the rear shaft 212 also has a spline. Further, when the steering torque is input from the handle device HMD, the shaft 210 is given a torsion angle corresponding to the steering torque to the torsion bar. Further, a substantially hollow sensor shaft is fixed to each of the front side shaft 211 and the rear side shaft 212. The sensor shaft is formed with a groove that changes the cross-sectional area of the abutting surface in the torsional direction, and causes relative movement in the axial rotation direction according to the torsion angle of the torsion bar, thereby changing the cross-sectional area of the abutting cross section. Note that the mechanism of the torsion bar and the sensor shaft are stored in the shaft case 220 and the torque sensor housing portion 230.

  In the torque sensor housing portion 230, the butting portion of the sensor shaft is disposed inside. Such a sensor shaft has a primary coil pivotally attached to one side and a secondary coil pivotally attached to the other (not shown). The primary coil and the secondary coil are connected to the signal terminal 240 and connected to the motor unit 100 via a signal cable (not shown). That is, when a voltage is applied to the primary coil and a torsion angle is generated in the torsion bar, a change in magnetic flux is generated by the sensor shaft in the secondary coil, so that the twist angle is indicated from the secondary coil side terminal of the signal terminal 240. The induced voltage is output to the motor unit 100.

  As shown in the figure, the gear box 250 is integrally formed with a gear side bracket 252, and the motor unit 100 is fixed using bolts and nuts B / N. The internal structure of the gear box 250 will be described with reference to FIG. This figure shows a cross-sectional view of the AA cross-section described in FIG. 2 observed in the direction of the arrow. In this gear box 250, a worm housing portion 251 and a flat worm housing portion 252 are integrally formed.

  The worm housing portion 251 includes an input shaft 253 that rotates in conjunction with the operation of the motor unit 100. The input shaft 253 is formed with a worm gear 253g and is rotatably supported by bearings 254a and 254b.

  The flat worm 252g is formed with teeth of the same module as the worm gear 253g and meshes with the worm gear 253g. The flat worm housing portion 252 has a rear side shaft 212 pivotally attached to the center thereof, and the rear side shaft 212 rotates in conjunction with the operation of the flat worm 252g.

  When a steering torque is applied to the rear side shaft 212, the gear box 250 outputs a signal from the torque sensor in response to the torsional deformation of the torsion bar, and requests the motor unit 100 to output the driving torque. When a driving torque is output from the motor unit 100, the motor unit 100 and the worm gear 253g are rotated, and an assist force is applied to the flat worm 252g. Such assist force applies an assist force to the front shaft 211 via the flat worm 252g, whereby the assist torque is applied to the steering torque from the operator at the front shaft 211 of the gear box 250, thereby An appropriate output torque is generated.

  FIG. 4 shows a circuit configuration of the motor unit 100. In the figure, the configuration of the torque sensor TS is shown for convenience. As shown in the figure, the circuit configuration of the motor unit 100 includes an electric motor EM, a full bridge circuit constituting the power conversion unit 175, a control circuit 151 mounted on a control board, and an electric circuit. Appropriate electrical elements are provided as necessary.

  The electric motor EM is connected to the full bridge circuit via the relay circuit 180. The electric motor EM is applied with driving power from a full bridge circuit according to the operation of the relay circuit 180. The relay circuit 180 is controlled by the central processing circuit 151b and regulates permission / non-permission of the driving power output to the electric motor EM. That is, the electric motor EM is driven by the full bridge circuit when the relay circuit 180 is in the ON state, and the driving power from the full bridge circuit is cut off when the relay circuit 180 is in the OFF state.

  The full bridge circuit 175 (power conversion unit in the claims) includes power semiconductor elements 175a to 175d, and an output line is provided in each inverter unit. One of the output lines is connected to the terminal Tm1 via the relay circuit 180, and the other is connected to the terminal Tm2. As the power semiconductor elements 175a to 175d, MOSFETs or IGBTs having gate terminals are used. The power semiconductor elements 175a to 175d are appropriately provided with a ceramic capacitor, a Zener diode, and the like that protect the gate terminal. The power semiconductor elements 175a to 175d are heated by the passing current when a control signal is input to the gate terminal. In the present embodiment, the voltage value by the DC power is boosted to about 50V. Therefore, the amount of heat corresponding to this is generated in the power semiconductor element. Such a full bridge circuit converts the input DC power to output the driving power and supplies the driving power to the electric motor EM as described above. The power conversion unit in the claims is not limited to a full bridge circuit, and may be, for example, an inverter circuit. In addition, the power conversion unit performs power conversion using the power semiconductor element described above. I just need it.

  The power semiconductor element 175k is connected to an electric circuit that relays the input electric circuit. The power semiconductor element 175k is driven in accordance with a control signal from the drive circuit 151d. In some cases, the input power applied to the power supply terminal Vb is relayed to the filter circuit 144. In other situations, the input power to the filter circuit is used. Shut off the supply.

  The control circuit 151 is provided in a state that is physically independent from the full bridge circuit, and is installed at a position that is not affected by the heat generated in the full bridge circuit. As shown in the figure, the control circuit 151 includes a torque sensor detection circuit 151a, a central processing circuit 151b, an operation monitoring circuit 151c, a drive circuit 151d, a thermal detection circuit 151e, an overcurrent detection circuit 151f, and a CAN communication circuit. The torque sensor detection circuit 151a detects a potential difference generated between both coils of the torque sensor TS and outputs it to the central processing circuit 151b. The CAN communication circuit receives speed information from the ECU and communicates necessary information bidirectionally. The drive circuit 151d outputs control signals for driving the power semiconductor elements 175a to 175d and 175k. The thermal detection circuit 151e and the overcurrent detection circuit 151f receive signals from the thermistor 175e and the shunt resistor 175f, and output a warning signal to the central processing circuit 151b when the respective reference values are exceeded. The central processing circuit 151b outputs a control signal based on the signal of the torque sensor TS and the speed information. Such control signals drive the power semiconductor elements 175a to 175d, 175k, respectively. The central processing circuit 151b is provided with a plurality of fail safe functions. For example, when a signal indicating an abnormal state is input from the thermal detection circuit 151e or the overcurrent detection circuit 151f, the central processing circuit 151b stops outputting the control signal and stops driving the electric motor EM. In addition, an operation monitoring circuit 151c is connected to the central processing circuit 151b so that bidirectional communication is possible. The operation monitoring circuit 151c executes the same arithmetic processing as the central processing circuit 151b, and outputs the processing result to the central processing circuit 151b at every predetermined timing. At this time, the central processing circuit 151b outputs a control signal only when its own processing result and the processing result from the operation monitoring circuit 151c match, and when both processing results do not match, the central processing circuit 151b outputs the control signal. Stop output. That is, if a difference occurs in the processing result of the operation monitoring circuit 151c, the central processing circuit 151b determines that an error has occurred in its processing result and stops the operation of the electric motor EM. The torque sensor detection circuit 151a, the drive circuit 151d, the thermal detection circuit 151e, the overcurrent detection circuit 151f, the CAN communication circuit, etc. are configured by appropriate ICs, and the central processing circuit 151b and the operation monitoring circuit 151c are the CPU and others. It is composed of a microcomputer and DSP having a memory circuit and the like. In other words, all the electrical elements configured as the control circuit 115 are driven by weak electric power, and do not require high power as in a power semiconductor element.

  In the present embodiment, the circuit for electric circuit described above includes a filter circuit 144 and a relay circuit 180. The electric circuit connects the power supply line 177a from the power supply terminal Vb to which the DC power is applied to the full bridge circuit, the power supply line 177b from the full bridge circuit to the ground terminal GND, and the full bridge circuit and the electric motor EM. Output lines 177c and 177d to be included.

  The filter circuit 144 is inserted in the electric circuit 177a from the terminal Vb to which DC power is input to the full bridge circuit. The filter circuit 144 is appropriately provided with electrical elements such as a capacitor, a reactor, and a resistor.

  Note that the circuit configuration is satisfied if at least one of the relay circuit 180 and the filter circuit 144 exists. For example, even when there is no filter circuit 144, an electric circuit is formed by the relay circuit 180. When only the filter circuit 144 exists, the electric circuit is formed by such a circuit. To do. That is, the circuit for the electric circuit indicates a circuit connected to the electric circuits 177a to 177d as illustrated.

  5 to 6 show the configuration of the motor unit 100 according to the present embodiment. As shown in the figure, the motor unit 100 includes an electric motor EM, an inner bottom surface 120, a drive shaft 114, a power element substrate 170, a power distribution unit 140, and a control device 150 incorporating a control substrate. In the following description, the arrow direction DH in the figure is the heat dissipation direction, and the arrow direction DM is the motor direction.

  The electric motor EM uses a brush motor in the present embodiment, and specifically includes a rotor 111a, a permanent magnet 111e, and a commutator 111c. When the coil is wound inside the slit and the driving power is applied from the power conversion unit 175, the rotor 111a changes the state of the magnetic flux inside the rotor 111a. Permanent magnets are arranged around the rotor 111a with alternating polarities. The commutator 111c is fixed to the rotor 111a, arranges conductor regions and insulating regions alternately on the cylindrical surface, and reverses the polarity of current for each region. The conduction region is electrically connected to the coil of the rotor 111a. As shown in the figure, the brush assembly 111b has a plurality of brush elements 112 arranged therein. The casing of the brush assembly 111b is formed of an insulating material, and wiring that is electrically connected to the brush element 112 is integrally formed.

  The motor cover 160 is made of a substantially cylindrical metallic material, and the thickness is set according to the force applied to the cylindrical body. As shown in the figure, the motor cover 160 is formed with a flange 161 having a through hole 161a, and the thickness is set according to the force applied to the motor cover 160 even in the flange 161. In addition, as described above, the motor cover 160 accommodates the rotor 111a and has permanent magnets arranged coaxially with the rotor. The meaning of the term “motor cover for storing the electric motor” in the claims is not limited to the aspect in which all the configurations of the rotor, the permanent magnet, and the commutator are stored in the motor cover. Including any aspect in which any of the configurations is not accommodated in the motor cover (for example, an aspect in which the permanent magnet and the rotor are accommodated in the motor cover and the commuter is not accommodated in the motor cover), A mode in which a part of the commuter 111c is not fully accommodated in the motor cover 160 (for example, as shown in the drawing) is also included.

  As shown in FIG. 6, when the electric motor EM is assembled, the contact surfaces of the brush elements 112 and the surface of the commutator 111c are in contact with each other. Therefore, when driving power is applied to the brush element 112, the rotor 111a rotates due to the magnetic force generated in the coil, and the commutator 111c also rotates accordingly. At this time, in the rotor 111a, the current flowing through the coil is commutated by the commutator 111c, and the rotation operation of the rotor 111a is maintained. Such an electric motor EM generates a drive torque on the drive shaft 114 in accordance with the turning operation of the built-in rotor 111a.

  As shown in the figure, the drive shaft 114 is fixed to the rotor 111a, and outputs a drive torque when the rotor 111a is driven. One end of the drive shaft 114 is supported by a bearing mechanism 162 in the motor direction DM, and the other end (heat radiation side DH) is supported by a bearing BR described later. A male-side spline 114a is formed on the heat dissipation side DH of the drive shaft 114, and is connected to the input shaft 253 via a socket SC in which a female-side spline is formed.

  The power element substrate 170 is mounted with a power converter 175, that is, power semiconductor elements 175a to 175d, 175k. Further, a thermistor 175e and a shunt resistor 175f may be mounted. Such an element is arranged in the vicinity of the power semiconductor elements 175a to 175d, thereby exerting its function. Further, in this embodiment, the control vertical terminal 176 and the electric circuit vertical terminal 177 are appropriately arranged. In addition, the power element substrate 170 may be filled with an insulating resin to reinforce the insulation between the wirings. In this case, although there is a concern about the increase in weight due to the insulating resin, since the power element substrate 170 is disposed on the bottom surface of the motor side bracket 130, the center of gravity of the motor unit 100 does not move to the motor side DM.

  The motor-side bracket 130 is a bottomed cylindrical body as shown in the figure, and a bracket portion 131 and a case fixing piece 132 are integrally formed. The bracket portion 131 is formed with a bolt hole 131a and is fixed by the gear side bracket 252 and the bolt nut B / N. The case fixing piece 132 is formed with a female screw tap 132a, and the motor case 160 is fixed by a screw. Further, the power element substrate 170 is accommodated in the motor side bracket 130, and the power element substrate 170 is laminated on the bottom surface of the motor side bracket 130. That is, the power element substrate 170 is disposed on the heat dissipation side DH of the drive shaft 114. Thus, when the motor unit 100 is fixed to the gear side bracket 252, the bottom surface of the motor side bracket 130 and the gear side bracket 252 come into contact with each other, and the amount of heat generated in the power semiconductor devices 175a to 175d and 175k changes the contact surface. Is effectively transmitted to the key box 250. The motor side bracket 130 is preferably made of a material having high heat transfer performance. The material having high heat transfer performance is preferably, for example, aluminum, copper, or an alloy thereof. Further, the present invention is not limited to this, and a metal material having iron as a base material may be used.

  In addition, a bearing holder BH is formed on the motor side bracket 130, and an outer ring of the bearing BR is attached to the bearing holder BH. The bearing BR is mounted by a method such as press fitting or shrink fitting. On the other hand, the inner ring of the bearing BR is fixed to the drive shaft 114 by press fitting or the like, whereby the drive shaft 114 is pivotally supported with respect to the motor side bracket. In this embodiment, the durability is improved by using the bearing BR as a bearing. However, the present invention is not limited to this, and a sliding bearing or the like may be employed.

  The bearing holder BH that accommodates the bearing BR is formed on the heat radiation side DH of the motor side bracket 130, and the bearing BR is inserted from the position of the heat radiation side DH to the motor side DM with respect to the power element substrate 170, The bearing holder BH is preferably mounted. Thereby, the opening part of a bearing holder is distribute | arranged to the outer peripheral surface side of the motor side bracket 130, and the bearing BR does not need to decompose | disassemble the circuit inside the motor side bracket 130, when performing replacement | exchange work or repair work. . Further, when the motor-side bracket 130 is removed from the gear box 250, the state of the bearing BR can be visually checked, and it is possible to easily determine whether or not the bearing BR is out of order.

  The control device 150 includes a container 154, a control board 153, and a control-side terminal 152 as shown in the figure. Among these, the container 154 has a substantially rectangular shell shape and is fixed to the side surface 163 of the motor cover. The housing 154 houses a control board 153 that controls the power semiconductor elements 175a to 175d and 175k. The control board 153 is mounted with a weak electrical element constituting the control circuit 151, and a control-side terminal 152 is appropriately connected to the land mounted on the board. Since the control board 153 is provided in a state independent of the power element board 170, the configuration of the heat dissipation mechanism in the control device 150 is omitted as much as possible, and the control board 153 and the control device 150 are reduced in size and weight. The Further, since the configuration of the power semiconductor element and the filter circuit is eliminated, the size and weight of the control device 150 can also be reduced. Further, since the control board 150 is mounted with an element for low electric current, it is not necessary to impregnate the mounting surface with an insulating resin, thereby reducing the weight of the control device 150. That is, since the weight of the control device 150 can be reduced as described above, the force due to the weight of the control device 150 can be minimized in the motor cover 160 even if vibration occurs.

  The control device 150 is preferably made of a resin material. Thereby, further weight reduction is achieved. The control device 150 may be fixed to the motor cover 160 using fastening means such as screws or bolts (not shown), or may be bonded to the motor cover 160 using an adhesive.

  As shown in FIG. 5, the power distribution unit 140 includes a power terminal 141, a control terminal group 142, an electric circuit terminal group 145, and an electric circuit. Among these, the power terminal 141 includes a terminal portion and an insulating connector structure, and the terminal portion is provided with terminals Vb, GND, and the like. The control terminal group 142 is electrically connected to terminals provided on the control board. When the control device 150 is connected to the power distribution unit 140, the control terminal group 142 has one end connected to the control board 153 via the control side terminal 152 and the other end connected to the control vertical terminal as shown in FIG. 176 is connected to the printed wiring of the power element substrate 170. Further, when the power distribution unit 140 and the brush assembly 111b are assembled to the motor-side bracket 130, one end of the electric circuit terminal group 145 is connected to the brush element 112 via the brush terminal 111d and the other end is connected to the electric circuit. It is connected to the printed wiring of the power element substrate 170 via the vertical terminal 177, thereby playing the role of the electric paths 177c and 177d. The circuit for electric circuit is a circuit inserted in the electric circuit, and the filter elements 144a and 144b and the relay circuit 180 are appropriately mounted on the circuit board. The filter element refers to a relatively large element such as an electrolytic capacitor, a film capacitor, or a coil. That is, by consolidating large electrical elements in the power distribution unit 140, the control board 153 can be further reduced in size and weight.

  The power distribution unit 140 is preferably disposed between the control board 153 and the power element board 170. As a result, the power distribution unit 140 distributes the high power to be relayed to the power semiconductor element and the weak power used by the control board 153, thereby making the control board 153 and the power element board 170 physically independent. It becomes possible. Further, since the power distribution unit 140 configures short-circuit electric paths 177a to 177b and the like by each terminal group without using a harness, the influence of parasitic inductance is reduced, and the element size of the filter circuit 144 can be reduced. It becomes possible. That is, in the power distribution unit 140, the housing of the power distribution unit is downsized as the filter circuit 144 is downsized.

  Further, since the power distribution unit 140 forms a physical distance between the control device 150 and the power element substrate 170, the amount of heat generated in the power element substrate 170 is difficult to be transmitted to the control substrate 153. The control device 150 omits a large heat radiation structure such as a heat radiation fin, and thus simplifies the configuration and reduces the weight. The control device 150 can output a control signal without malfunction under a favorable temperature environment. Therefore, since the risk of emergency stop due to fail-safe is reduced, the electric power steering apparatus 200 can stably supply the assist torque.

  Further, the power distribution unit 140 has an angle forming surface 146 formed on the motor side DM, and a container 154 constituting the control device 150 is fixed to the angle forming surface 146. The angle forming surface 146 forms a predetermined angle θ with respect to the side surface 163 of the motor cover, and is approximately 90 degrees in the figure. However, the angle forming surface 146 may be such that the angle θ formed by both surfaces is not 0 degree (or 180 °). Accordingly, the container 154 is supported by two surfaces, and vibrations and inertial forces generated in the control device 150 are distributed to the angle forming surface 146 and the side surface 163 of the motor cover. The applied force is reduced. Further, by giving a predetermined angle θ between the angle forming surface 146 and the side surface 163 of the motor cover, a force such as vibration is distributed to the two surfaces regardless of the direction of the vibration or inertial force. Become.

  Further, the predetermined angle θ is preferably about 90 degrees. This is because the shape of the container 154 is a normal shape having a right-angled surface. Further, the vibration or inertial force acting on the control device 150 effectively distributes the force to the two surfaces when the predetermined angle θ is 90 °.

  Further, it is preferable that the angle forming surface 146 is appropriately offset from the position of the power element substrate 170 toward the motor direction DM (distance DF in the figure). Accordingly, an appropriate space is secured inside the power distribution unit 140, and the filter circuit and the circuit board can be accommodated therein.

  Further, the coupling structure for fixing the container 154 and the power distribution unit 140 may be a fitting structure, a labyrinth structure, or a chemical coupling structure using an adhesive. With such a strong coupling structure, a force such as vibration generated in the control device 150 is effectively transmitted to the power distribution unit side. On the other hand, in the motor cover 160, a force such as vibration generated in the control device 150 is suppressed.

  In addition, the coupling structure (fixing portion in the claims) that fixes the container 154 and the power distribution unit 140 is waterproofed to protect the internal circuits (power semiconductor element, filter circuit, control board). preferable. In such waterproofing treatment, a sealing member (O-ring, packing, etc.) may be attached between both structures, and the joint portion of both structures may be sealed and welded.

  As described above, according to the 100 motor unit according to the present embodiment, the control device 150 fixed to the side wall 161 of the motor cover 160 is reduced in weight, so that the coupling structure between the motor cover 160 and the motor side bracket 130 is also improved. This simplifies, thereby avoiding an increase in size and weight of the apparatus, and at the same time, preventing an increase in cost.

  Further, according to the 100 motor unit according to the present embodiment, since the force such as vibration applied to the side wall 161 of the motor cover 160 is suppressed, this also avoids an increase in size and weight of the apparatus. , To prevent high cost.

  Further, according to the electric power steering apparatus 200 according to the present embodiment, since the bending moment acting on the contact surface between the motor unit 100 and the bracket 252 of the gear box 250 is suppressed, the structure around the bracket of the gear box 250 is simple. To avoid the increase in size and weight of the apparatus, and to prevent the increase in cost.

DESCRIPTION OF SYMBOLS 100 Motor unit for electric power steering 200 Electric power steering apparatus EM Electric motor 175 Electric power conversion part 130 Motor side bracket 153 Control board

Claims (6)

An electric motor that generates drive torque on the drive shaft according to the turning operation of the built-in rotor, and power that is composed of a power semiconductor element and that outputs drive power for driving the electric motor by converting input power A converter, a power element substrate on which the power semiconductor element is mounted, a motor-side bracket in which the power element substrate is accommodated, a power distribution part in which at least a filter circuit inserted in an electrical path is accommodated, and electric power comprising: a motor cover for storing the electric motor, and a control device which has housed inside the housing body control board comprises a container to control the power semiconductor element is fixed to the side surface of the motor cover In the steering motor unit,
The electric power steering motor unit , wherein the power distribution unit has an angle forming surface that forms a predetermined angle with respect to a side surface of the motor cover, and the container is fixed to the angle forming surface . The motor unit for electric power steering according to claim 1 , wherein the angle forming surface is substantially perpendicular to a side surface of the motor cover. The motor unit for electric power steering according to claim 2 , wherein the angle forming surface is offset from the position of the power element substrate toward the motor. The electric power steering motor unit according to any one of claims 1 to 3, wherein the container is made of a resin material. The motor power steering motor unit according to any one of claims 1 to 4, wherein the fixing portion between the container and the power distribution unit is waterproofed. An electric power steering motor unit according to any one of claims 1 to 5, and a gear box that adds the assist torque to a steering torque according to a turning operation of a steering handle. Electric power steering device.

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