JP2008189146A - Electric power steering device and assembling method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To attain miniaturization and light weight by efficiently transmitting heat generated on a control unit to a speed reduction gear box while eliminating a motor harness between an electric motor and the control unit. <P>SOLUTION: A torque sensor, the electric motor 5 and the control unit 19 are assembled to the speed reduction gear box 4, and the electric motor 5 is constituted of a brushless motor having electric contacts tm1-tm3 for outside connection connected to a motor coil. The control unit 19 has electric contacts tc1-tc3 connected to the electric contacts of the electric motor 5, and the electric contacts of the electric motor 5 and the electric contacts of the control unit are arranged at a position where they are directly connected to each other in a state that the electric motor 5 and the control unit 19 are assembled to the speed reduction gear box 4. Further, the control unit is assembled to the speed reduction gear box so as to directly transmit heat generated when the electric motor 5 is energized and controlled to the speed reduction gear box 4. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  In the present invention, the steering torque transmitted to the steering shaft is detected to drive and control the electric motor, and the steering assist force generated by the electric motor is transmitted to the steering shaft via the reduction mechanism in the reduction gear box. The present invention relates to an electric power steering apparatus and an assembling method.

  In recent years, demands for vehicle fuel efficiency improvement and integrated control have increased, and electric power steering devices have begun to be adopted not only for small vehicles but also for large vehicles that require large steering assist thrust. In order to increase the output of the electric motor that generates the steering assist force, it is necessary to increase the motor current. Accordingly, the wiring loss of the motor harness connecting the control unit that controls the drive of the electric motor and the electric motor. Will increase and efficiency will decrease.

For this reason, conventionally, a housing with a metal substrate fixed in close contact is disposed on the opposite side of the electric motor, and heat radiating fins are provided on the outer side of the housing and on the inner side and outer side of the cover attached to the electric motor. The power board, large current board and control board are built in a laminated structure, and the motor terminal protruding from the large current board to the outside of the cover is inserted into the electric motor and electrically connected to the electric motor. A steering device is known (see, for example, Patent Document 1).
JP 2003-267233 A

  However, in the conventional example described in Patent Document 1, a power board, a large current board, and a control board that constitute a control device that controls an electric motor are stacked and built in a housing and a cover, and the cover is electrically driven. It is configured to be directly attached to the motor, and heat is generated by the control device, but the electric motor is also a heat source, so the heat generated by the control device is generated by the reduction gear having a large heat capacity and a large surface area via the electric motor. Heat can not be transferred efficiently to the gearbox, and as a countermeasure against this, heat dissipation is improved by providing heat dissipation fins, but it is impossible to avoid an increase in the size of the control device due to the provision of heat dissipation fins. There are unresolved issues.

  Therefore, the present invention has been made paying attention to the unsolved problems of the above-described conventional example, and the heat generated in the control unit is efficiently generated in the reduction gear box while omitting the motor harness between the electric motor and the control unit. An object of the present invention is to provide an electric power steering device and an assembling method that can conduct heat well and can be reduced in size and weight.

  In order to achieve the above object, an electric power steering apparatus according to claim 1 includes a steering column having a steering shaft to which steering torque is transmitted, a torque sensor for detecting the steering torque, and a reduction gear on the steering shaft. An electric power steering apparatus comprising: an electric motor that transmits a steering assist force via a reduction mechanism in a box; and a control unit that drives and controls the electric motor based on a steering torque detected by the torque sensor, The torque sensor, the electric motor, and the control unit are assembled to the reduction gear box, and the electric motor is composed of a brushless motor having an electrical contact for external connection connected to a motor coil, and the control unit Is an electrical contact that connects to the electrical contact of the electric motor. And the electrical contact of the electric motor and the electrical contact of the control unit are arranged in a portion where they are directly connected to each other in a state where the electric motor and the control unit are assembled to the reduction gear box, and The control unit is assembled to the reduction gear box so that heat generated when energization control of the electric motor is directly transferred to the reduction gear box.

In the invention according to claim 1, since the electric motor and the control unit are assembled in a reduction gear box having a large heat capacity and a large surface area, the heat generated by the control unit can be efficiently transferred to the reduction gear box. The radiating fins of the unit can be made as small as possible or omitted, and the electric power steering device can be reduced in size and weight.
In addition, since the motor coil and the output stage of the control unit can be connected without going through a wire harness, the wire harness for energizing the motor can be omitted, and it is compact and lightweight, low cost, and high efficiency with reduced wiring loss A simple electric power steering apparatus can be provided.

Further, since the electric motor is a brushless motor, there is no loss due to the contact resistance of the brush, and in combination with the omission of the wire harness for energizing the motor, it can be achieved by only one of the low loss methods. The electric power steering apparatus can be applied to a large vehicle that requires a large steering assist thrust.
In addition, when applied to a small vehicle while not requiring a large steering assist thrust, the loss is small, so that the electric motor and the control unit can be made smaller than the current situation.

  According to a second aspect of the present invention, there is provided the electric power steering apparatus according to the first aspect of the invention, wherein the electric motor detects a rotor rotation angle disposed on the output shaft side and provides an electrical contact for external connection. A rotor rotation angle detector, and the control unit includes an electrical contact connected to an electrical contact of the rotor rotation angle detector, and the electrical contact of the rotor rotation angle detector and the electrical power of the control unit. The electrical contact and the control unit are arranged at portions that are directly connected to each other in a state where the electric motor and the control unit are assembled to the reduction gear box.

  In the invention according to claim 2, since the electrical contact connected to the rotor rotation angle detector and the electrical contact for receiving the signal of the rotor rotation angle detector in the control unit can be directly connected, the rotor rotation angle Since the detector and the control unit can be connected without going through the wire harness, the wire harness for transmitting the rotor rotation angle signal to the control unit can also be omitted, and the electric power steering apparatus can be reduced in size and weight and at a lower cost. Can be provided.

  Furthermore, the electric power steering apparatus according to a third aspect is the invention according to the twelfth aspect, wherein the electric motor includes a connecting portion that is fitted to a motor mounting surface of the reduction gear box and is bolted. The rotor rotation angle detector is built in the connecting portion, and the electrical contact of the electric motor is formed to protrude in at least one of the vertical direction and the horizontal direction with respect to the speed reduction gear box side end surface, and the rotor rotation The electrical contact of the angle detector is characterized in that it is formed to project in at least one of the vertical direction and the horizontal direction with respect to the end face on the side of the reduction gear box.

  In the invention according to claim 3, the electrical contact connected to the motor coil of the electric motor protrudes from the end face of the connecting portion in at least one of the vertical direction and the horizontal direction, and is a control assembled to the reduction gear box. Direct connection with the electrical connection terminal of the unit is facilitated, and the wiring from the output stage of the control unit to the motor coil can be made very short, so that wiring loss can be reduced and a highly efficient electric power steering device is provided. be able to.

  In addition, since the electrical contact of the rotor rotation angle detector is formed so as to protrude in at least one of the vertical direction and the horizontal direction with respect to the end face of the motor flange on the speed reduction gear box side, It is easy to connect directly to the contact point, and the rotor rotation angle signal necessary for the brushless motor commutation can be transmitted to the control unit without using a wire harness. Therefore, an inexpensive electric power steering device can be provided. it can.

  Furthermore, an electric power steering apparatus according to a fourth aspect is the invention according to any one of the first to third aspects, wherein the torque sensor is an external connected to either the torque detection element or its signal processing circuit. An electrical contact for connection, and the control unit has an electrical contact connected to the electrical contact of the torque sensor, and the electrical contact of the torque sensor and the electrical contact of the control unit are related to the torque. The sensor and the control unit are arranged in a portion that is directly connected to each other in a state where the sensor and the control unit are assembled to the reduction gear box.

  In the invention according to the fourth aspect, since the electrical contact connected to the torque sensor and the electrical contact connected to the electrical contact of the torque sensor in the control unit can be directly connected, the torque sensor and the control are controlled. The unit can be connected to the unit without a wire harness, the wire harness for transmitting the steering torque to the control unit can be omitted, and a small, light and low-cost electric power steering can be provided.

Still further, according to a fifth aspect of the present invention, in the electric power steering apparatus according to the fourth aspect, the torque sensor may be mounted on the mounting surface of the control unit in a state where the electrical contact is assembled to the reduction gear box. And projecting vertically.
In the invention according to claim 5, since the electrical contact of the torque sensor protrudes in the vertical direction from the control unit mounting surface of the reduction gear box in the state where it is attached to the reduction gear box, it is attached to the reduction gear box. Direct connection with the electrical connection terminal of the control unit is facilitated, and the steering torque essential for control of the electric power steering device can be transmitted to the control unit without using a wire harness. It can be downsized.

An electric power steering apparatus according to a sixth aspect is the invention according to any one of the first to fifth aspects, wherein the speed reduction mechanism is configured by a worm speed reducer, and the control unit mounting surface of the speed reduction gear box. Is a plane perpendicular to the worm wheel axis direction.
In the invention according to claim 6, since the control unit mounting surface is a plane perpendicular to the axial direction of the worm wheel, the steering torque sensor built in the steering wheel side of the worm wheel and the end of the worm shaft are provided. The control unit can be arranged to straddle the arranged electric motor, and it becomes easy to directly connect the torque sensor and the end of the control unit. This can be transmitted to the control unit without using a harness, and the electric power steering apparatus can be reduced in size.

Furthermore, the electric power steering apparatus according to a seventh aspect is the invention according to any one of the first to third aspects, wherein the control unit has a shape in the width direction that is line-symmetric with respect to the axis of the electric motor. It is characterized by being formed.
In the invention according to claim 7, since the shape in the width direction of the control unit is axisymmetric with respect to the axis of the electric motor, the mounting direction of the electric motor is changed according to the right-hand drive vehicle and the left-hand drive vehicle. Even if it exists, since there is no difference in installation height, it is not necessary to change an electric motor and a control unit, and a low-cost electric power steering apparatus can be provided.

Furthermore, an electric power steering apparatus according to an eighth aspect is the invention according to any one of the first to fifth aspects, wherein an electrical contact of the control unit with respect to the electric motor is caused by a screw axial force of the electric motor. It is characterized by comprising a screw terminal that is brought into electrical contact with an electrical contact.
In the invention according to claim 8, the control unit is provided with a screw terminal that contacts the motor-side electrical contact by a screw axial force and is electrically connected as an electrical contact to be connected to the electrical contact of the electric motor. Since it is used, a strong and reliable electrical connection is achieved, wiring loss can be reduced, and variations in contact resistance can be suppressed.

  Still further, according to a ninth aspect of the present invention, there is provided an electric power steering apparatus according to any one of the first to fifth aspects, wherein the electrical contact of the control unit with respect to the electric motor is caused by a spring pressure. A spring contact terminal that is in electrical contact with an electrical contact, and the insertion port of the spring contact terminal is mounted on the motor mounting surface of the reduction gear box in a state where the control unit is assembled to the reduction gear box. It is characterized by being opened toward.

  In the invention according to claim 9, the control unit includes a spring contact terminal that is connected to the electrical contact of the electric motor by the spring pressure as the electrical contact to be connected to the electrical contact of the electric motor. The insertion port is open toward the motor mounting surface in the reduction gear box in the state where the control unit is assembled to the reduction gear box, so when attaching the electric motor to the motor mounting surface, By simply inserting the electrical contacts of the electric motor, electrical connection can be made, wiring loss can be reduced, man-hours can be reduced, and the electrical contacts are not mechanically fixed to each other. It is possible to release stress caused by attachment error, accuracy of each part, difference in linear expansion coefficient, and the like.

An electric power steering apparatus according to a tenth aspect is the invention according to any one of the first to fifth aspects, wherein the electrical contact of the control unit to the electric motor is performed by either welding or soldering. The electrical connection with the electrical contact of the electric motor is performed.
In the invention according to claim 10, since the electrical contacts of the control unit and the electric motor are connected by either welding or soldering, a strong and reliable electrical connection can be obtained, and the wiring loss can be reduced. In addition, variations in contact resistance can be suppressed.

Furthermore, an electric power steering apparatus according to an eleventh aspect is the invention according to the second or third aspect, wherein an electrical contact of the control unit to the rotor rotation angle detector is an electrical contact of the rotor angle detector by a spring pressure. It is characterized by comprising a spring contact terminal that is brought into contact with the contact to be electrically connected.
In the invention according to claim 11, the control unit is electrically connected to the electrical contact of the rotor rotation angle detector by the spring pressure as the electrical contact connected to the electrical contact of the rotor rotation angle detector of the electric motor. Spring contact terminals that can be connected to each other, and the insertion port is open toward the motor mounting surface of the reduction gear box when the control unit is assembled to the reduction gear box. When the motor is mounted on the motor mounting surface, the electrical connection can be obtained simply by inserting the electrical contact of the rotor rotation angle detector into the spring contact terminal, and the number of connection steps can be reduced.

Furthermore, the electric power steering device according to claim 12 is the invention according to claim 2 or 3, wherein the electrical contact of the control unit with respect to the rotor rotation angle detector is performed by either welding or soldering. The electrical connection with the electrical contact of the rotation angle detector is performed.
In the invention according to claim 12, since the electrical connection between the control unit and the rotor rotation angle detector is stronger and more reliable than welding or soldering, contact failure of the contact is prevented to prevent contact failure. Reliability can be increased.

Still further, according to a thirteenth aspect of the present invention, in the electric power steering device according to the fourth or fifth aspect, the electrical contact of the control unit to the torque sensor contacts the electrical contact of the torque sensor by a spring pressure. It is characterized by comprising spring contact terminals that are electrically connected.
In the invention according to claim 13, the control unit uses a spring contact terminal that is connected to the electrical contact of the torque sensor by the spring pressure as the electrical contact to be connected to the electrical contact of the torque sensor. When the control unit is assembled to the reduction gear unit, the insertion port is open to the control unit mounting surface of the reduction gear unit when the control unit is assembled to the reduction gear box. By simply inserting the electrical contact of the torque sensor into the spring contact terminal, an electrical enemy connection can be made and the connection man-hours can be reduced.

According to a fourteenth aspect of the present invention, there is provided the electric power steering apparatus according to the fourth or fifth aspect, wherein the electrical contact of the control unit to the torque sensor is an electric contact of the torque sensor by welding or soldering. It is characterized in that electrical connection with the contact is made.
In the invention according to claim 14, since the electrical connection terminals of the control unit and the torque sensor are firmly and securely electrically connected by welding or soldering, the contact failure of the contact is prevented and the reliability is improved. Can do.

Furthermore, an electric power steering apparatus according to a fifteenth aspect is the invention according to any one of the first to fourteenth aspects, wherein the electrical contact of the control unit to the electric motor has a waterproof and dustproof sealing mechanism. It is characterized by being provided.
According to the fifteenth aspect of the present invention, since the sealing mechanism for waterproofing and dustproofing is provided at the junction of the electrical contacts of the control unit and the electric motor, only the column assist type electric power steering device installed in the vehicle interior is provided. In addition, the present invention can be applied to an electric power steering device arranged in an engine room, such as a pinion assist type or rack assist type electric power steering device.

The electric power steering apparatus according to claim 16 is the invention according to any one of claims 1 to 15, wherein the electrical contact of the control unit to the rotor rotation angle detector is waterproof and dustproof. A sealing mechanism is provided.
In the invention according to claim 16, since a sealing mechanism for waterproofing and dustproofing is provided at the junction of the electrical contacts of the control unit and the rotor rotation angle detector, the column assist type electric power installed in the vehicle interior is provided. The present invention can be applied not only to a steering device but also to an electric power steering device disposed in an engine room such as a pinion assist type or rack assist type electric power steering device.

Still further, an electric power steering apparatus according to claim 17 is the invention according to any one of claims 1 to 16, wherein the electrical contact of the control unit to the torque sensor is a sealing mechanism that is waterproof and dustproof. It is characterized by being provided.
In the invention according to claim 17, since a sealing mechanism for waterproofing and dustproofing is provided at the joint between the electrical contacts of the control unit and the torque detecting means, the column assist type electric power steering device installed in the vehicle interior In addition, the present invention can also be applied to an electric power steering device arranged in an engine room, such as a pinion assist type or rack assist type electric power steering device.

An electric power steering apparatus according to an eighteenth aspect of the present invention is the electric power steering apparatus according to any one of the first to seventeenth aspects, wherein the speed reduction mechanism includes a worm speed reducer and includes a worm shaft in the speed reduction gear box. A control unit mounting surface on which the control unit is mounted is formed at a site.
In the invention according to claim 18, the speed reduction mechanism is constituted by a worm speed reducer, and a control unit mounting surface for mounting the control unit is formed in a portion where the worm shaft in the speed reduction gear box is internally provided. By assembling the control unit so that the longitudinal direction thereof coincides with the axial direction of the worm shaft, the control unit can be laid out without protruding. In addition, a sufficient contact surface according to the seating surface of the control unit is obtained, and adhesion to the control unit is enhanced, so that the heat of the control unit to the reduction gear box is efficiently transferred to the control unit. The heat dissipating fins can be omitted, and the electric power steering apparatus can be miniaturized.

  Furthermore, the electric power steering apparatus according to claim 19 is the invention according to claim 3, wherein the speed reduction mechanism is constituted by a worm speed reducer, and the worm shaft and the output shaft of the electric motor are spline-coupled. The length is set longer than the protruding length of the electrical contact of the electric motor and the electrical contact of the rotor rotation angle detector from the end face of the mounting flange.

  In the invention according to claim 19, the joint between the worm shaft and the output shaft of the electric motor is a spline, and the fitting length is such that the electric contact of the electric motor and the electric contact of the rotor rotation angle detector are attached. Since it is longer than the projecting length from the flange end surface, the spline is shallowly fitted. Rotate the electric motor to align the rotor rotation angle detector and the electric motor electrical contact with the control unit electrical contact. This makes it possible to omit the wire harness for transmitting the rotor rotation angle signal and the wire harness for energizing the motor while using spline coupling as the shaft coupling.

  Furthermore, an assembly method for an electric power steering apparatus according to claim 20 includes a steering column having a steering shaft to which steering torque is transmitted, a torque sensor for detecting the steering torque, and a reduction gear box on the steering shaft. An electric power steering device for assembling an electric motor for transmitting a steering assist force through an internal speed reduction mechanism and a control unit for driving and controlling the electric motor based on a steering torque detected by the torque sensor to the reduction gear box The torque sensor is composed of a torque detection element, and a signal processing circuit for processing a steering torque detection signal detected by the torque detection element is incorporated in the control unit, and the torque sensor is Installed in the reduction gearbox, then the torque sensor The control unit is assembled to the reduction gear box to electrically connect the torque detecting element and the control unit, and then the electric motor is assembled to the reduction gear box to electrically connect the control unit and the electric motor. It is characterized by connecting.

  In the invention according to claim 20, the torque sensor is composed of only the torque detection element, the signal processing circuit is built in the control unit, and the control unit is assembled to the reduction gear box in which the torque detection element is built. In this state, the electrical enemy is connected between the control unit and the torque detection element, and then the electric motor is assembled to the reduction gear box. Therefore, when the control unit is assembled to the reduction gear box with the torque detection element built in, Calibration of the signal processing circuit can be performed. For this reason, it is possible to calibrate the signal processing circuit without providing the signal processing circuit separately from the control unit while omitting the wire harness and without being affected by the electric motor, and without reducing the accuracy of the torque sensor. This can be done by reducing the number of parts.

  Still further, the electric power steering apparatus assembling method according to claim 21 includes a steering column having a steering shaft to which steering torque is transmitted, a torque sensor for detecting the steering torque, and a reduction gear box on the steering shaft. An electric power steering device for assembling an electric motor for transmitting a steering assist force through an internal speed reduction mechanism and a control unit for driving and controlling the electric motor based on a steering torque detected by the torque sensor to the reduction gear box The torque sensor is composed of a torque detection element and a signal processing circuit that performs signal processing on the steering torque detection signal, and the torque detection element and the signal processing circuit are assembled to the reduction gear box. And then assembling the electric motor to the reduction gearbox In assembling the control unit to the reduction gear box is characterized in that to perform the electrical connection between the electrical connection and control unit and the electric motor between the control unit and the torque detection element.

  In the invention according to claim 21, since the torque sensor is calibrated by the torque detection element and the signal processing circuit, and the signal processing circuit is arranged separately from the control unit, the signal processing in the torque sensor in the state of the reduction gearbox alone. Circuit calibration can be performed. Then, in the state where the electric motor is assembled to the reduction gear box whose signal processing circuit has been calibrated, and then the control unit is assembled to the reduction gear box, the electrical connection between the control unit and the torque detection element, the control unit, Since electrical connection is made between the electric motors, assembly is facilitated, and the assembly process can be simplified without degrading the accuracy of the torque sensor.

  According to the present invention, since the electric motor and the control unit are assembled to the reduction gear box, the heat generated by the control unit can be directly and efficiently transferred to the reduction gear box having a large heat capacity and a large surface area. The heat dissipating fins can be made as small as possible or omitted to reduce the size and weight of the control unit, and since a brushless motor is used as the electric motor, there is no loss due to brush contact resistance, and the motor A wire harness for energization can be omitted, a large steering assist thrust can be generated, and an effect that the electric power steering device can be applied to a large vehicle is obtained.

In addition, when applied to a small vehicle while not requiring a large steering assist thrust, since the loss is small, an effect that the electric motor can also reduce the size of the control unit compared to the current state can be obtained.
In addition, the motor harness between the control unit and the electric motor can be omitted, and the wire harness between the control unit and the rotor rotation angle detector such as a resolver attached to the electric motor and the steering torque sensor attached to the reduction gear box. Therefore, it is possible to provide an electric power steering apparatus that is smaller, lighter, and lower in cost.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a perspective view showing an example in which an embodiment of the present invention is applied to a right-hand drive vehicle, FIG. 2 is an exploded perspective view of FIG. 1, and FIG. 3 is a perspective view of a state in which the electric motor of FIG. 4 is a longitudinal sectional view of the reduction gear box, FIG. 5 is a perspective view of the electric motor, FIG. 6 is an exploded perspective view of the electric motor, and FIG. 7 is a perspective view of the control unit.

  In FIG. 1, reference numeral 1 denotes a column assist type electric power steering device, in which a reduction gear box 4 is connected to a steering column 3 that rotatably houses a steering shaft 2 connected to a steering wheel (not shown). The reduction gear box 4 is provided with an electric motor 5 composed of a brushless motor whose axial direction is extended in a direction perpendicular to the axial direction of the steering column 3.

Here, the steering column 3 has a double-pipe structure of an inner tube 3a and an outer tube 3b that secures a predetermined collapse stroke by absorbing impact energy at the time of collapse at a connecting portion with the reduction gear box 4. The outer tube 3 b and the reduction gear box 4 of the steering column 3 are attached to the vehicle body side by an upper mounting bracket 6 and a lower mounting bracket 7.
The lower mounting bracket 7 is formed by a mounting plate portion 7a attached to a vehicle body side member (not shown) and a pair of support plate portions 7b extending in parallel with a predetermined distance on the lower surface of the mounting plate portion 7a. ing. And the front-end | tip of the support plate part 7b is connected with the support part 4b integrally formed in the cover 4a arrange | positioned at the lower end side of the reduction gear box 4, ie, the vehicle body front side, via the pivot 7c so that rotation is possible.

The upper mounting bracket 6 includes a mounting plate portion 6a attached to a vehicle body side member (not shown), a rectangular frame-shaped support portion 6b integrally formed with the mounting plate portion 6a, and the rectangular frame-shaped support portion. And a tilt mechanism 6c that supports the outer tube 3b of the steering column 3 formed in 6b.
Also, the tilt mechanism 6c can adjust the tilt position of the steering column 3 up and down around the pivot 7c of the lower mounting bracket 7 by rotating the tilt lever 6d to release the support state.

Further, as shown in FIG. 4, the steering shaft 2 includes an input shaft 2a whose upper end is connected to a steering wheel (not shown), and a torsion bar connected to the lower end of the input shaft 2a via a torsion bar 2b. And an output shaft 2c covering 2b.
Furthermore, as shown in FIGS. 2 to 4, the reduction gear box 4 is formed by die-casting, for example, any one of materials having high thermal conductivity such as aluminum, aluminum alloy, magnesium and magnesium alloy. ing. The reduction gear box 4 has a worm storage portion 12 for storing a worm 11 connected to the output shaft 5f of the electric motor 5, and a worm storage portion 12 having a central axis orthogonal to the central axis below the worm storage portion 12. The worm wheel storage part 14 for storing the worm wheel 13 meshing with the worm wheel 11, the torque sensor storage part 16 for storing the torque sensor 15 integrally and coaxially connected to the rear side of the worm wheel storage part 14, and the worm storage A motor mounting portion 17 for mounting the electric motor 5 formed on the open end surface of the portion 12 and a column mounting portion for mounting the mounting flange 3c formed on the front end portion of the steering column 3 formed on the rear end surface of the torque sensor storage portion 16. 18 and the worm wheel storage part 14 and the worm wheel storage part 14 across part of the worm wheel storage part 14 and And a control unit mounting section 20 for mounting the control unit (ECU) 19 which is formed in a plane perpendicular to the center axis of the torque sensor accommodating portion 16. Here, the control unit mounting portion 20 is cut into a flat shape in order to improve adhesion to the control unit 19.

The reduction gear box 4 is fixed to the steering column 3 by a bolt 18a in a state where the mounting flange 3c of the steering column 3 is in contact with the column mounting portion 18.
Here, as shown in FIG. 4, the torque sensor 15 magnetically detects the twisted state between the input shaft 2a and the output shaft 2c of the steering shaft 2 and uses the steering torque transmitted to the steering shaft as a torque detection element. Are detected by a pair of detection coils 15a and 15b.

  External connection terminals 15c, 15d and 15e, 15f projecting outward in parallel to the direction orthogonal to the central axis of the steering column 3 are connected to the start and end of winding of the pair of detection coils 15a and 15b, respectively. The projecting portions of the terminals 15c to 15f are bent at the central portion in parallel with the central axis of the steering column 3, and formed into an L shape, and as shown in FIG. It protrudes upward from an opening 22 formed in a guide surface 21 that guides the lower surface of the unit 19.

  Further, as shown in FIGS. 5 and 6, the electric motor 5 includes a bottomed cylindrical frame 5a having an open front end, a connecting portion 5b that covers the front end of the frame 5a and is attached to the reduction gear box 4, A motor stator 5c disposed in the frame 5a, a rear bearing 5d inserted into the motor stator 5c and fixed to the bottom of the frame 5a, and a front bearing 5e fixed to the connecting portion 5b are rotatably supported. The output shaft 5f, a surface magnet type motor rotor 5g having a permanent magnet formed on a surface fixed to a position of the output shaft 5f facing the motor stator 5c, and a position facing the connecting portion 5b of the motor rotor 5g. It is comprised by the resolver 5h as a rotor rotation angle detector which detects the rotor rotation angle arrange | positioned.

Here, as shown in FIG. 6, the frame 5 a is formed with a flange portion 5 i at a position 180 degrees away from the outer peripheral surface on the open end side.
Further, as shown in FIG. 6, the connecting portion 5b is formed with a flange mounting portion 5j at a position facing the flange portion 5i, and an electrical contact described later is provided on the outer peripheral surface of the intermediate position of the flange mounting portion 5j. An opening 5k that is exposed to the frame 5a is formed, and an inlay portion 5m that is inlayed to the frame 5a is formed on the end surface of the frame 5a. The flange attachment portion 5j on the opposite side of the inlay portion 5m is displaced in the circumferential direction. A mounting flange 5n to be mounted on the motor mounting portion 17 of the reduction gear box 4 described above is formed at a position, and an inlay portion 5o to be connected to the motor mounting portion 17 is formed inside the mounting flange 5n.

Further, the motor stator 5c is provided with a stator 5q in a cylindrical insulating case 5p, and is insert-molded with resin together with a substantially annular bus bar 5p connected to the end of a three-phase coil wound around the stator 5q. Motor terminals tm1 to tm3 are provided as electrical contacts for external connection.
These motor terminals tm1 to tm3 are a protruding portion 5r protruding in a radial direction perpendicular to the central axis of the electric motor 5 from the front end surface of the bus bar 5p of the motor stator 5c, and a central axis of the electric motor 5 from the upper end of the protruding portion 5r. And an extension portion 5s extending forward and a terminal portion 5t extending in the same direction as the protruding portion 5r from the front end of the extension portion 5s.

  Further, the rear bearing 5d and the front bearing 5e are constituted by deep groove ball bearings, and a fixed ring of the rear bearing 5d is fitted to an inner diameter portion of a protrusion formed on the bottom of the frame 5a, and a wave (not shown) is axially shown. A washer is inserted between the bottom of the projection and the end face of the fixed ring in the rear bearing 5d to give an axial preload. On the other hand, the fixed ring of the front bearing 5e is fitted to the connecting portion 5b and fixed in the axial direction with a retaining ring (not shown).

Further, the resolver 5h includes a resolver stator 5v fixed to an inner peripheral surface of a resolver case 5u fixed in the connecting portion 5b, and a resolver rotor 5w fixed to an output shaft 5f inserted into the resolver stator 5v. Have
When a sine wave excitation signal f (t) = A · sin (ωt) is input from an external signal processing circuit, the resolver stator 5v receives a sine wave and cosine wave resolver signal Ys corresponding to the rotation angle θ of the rotor. (= K · sin (θ) · f (t)) and Yc (= k · sin (θ) · f (t)) are output.

  Therefore, the resolver terminals tr1, tr2, and tr3, each of which includes a pair of excitation signal input terminals and resolver signal output terminals for inputting / outputting the excitation signal f (t) and the resolver signals Ys, Yc, are provided. The terminals tr1 to tr3 extend in the radial direction formed on the outer peripheral surface of the resolver case 5u, and the central axis of the output shaft 5f of the electric motor 5 from the protruding portion 5x protruding outward from the opening 5k formed in the connecting portion 5b. In other words, it projects forward in the direction perpendicular to the end face of the connecting portion 5b.

On the other hand, the protruding portion 5x is formed with an engaging groove 5y that engages with the protruding portion 5r of the motor terminals tm1 to tm3 of the motor stator 5c on the rear end surface, and an extended portion 5s of the motor terminals tm1 to tm3 on the front end surface. An engaging groove 5z to be engaged is formed.
Then, with the motor stator 5c, the rear bearing 5d, the front bearing 5e, the output shaft 5f, the motor rotor 5g, and the resolver 5h mounted in the frame 5a and the connecting portion 5b, the flange portion 5i of the frame 5a is connected to the flange of the connecting portion 5b. By screwing to the attachment portion 5j, the electric motor 5 can be assembled as shown in FIG.

  At this time, the resolver 5h accommodates the protruding portion 5x of the resolver case 5u protruding outward from the opening 5k in the connecting portion 5b, and the protruding portion 5x of the resolver case 5u and the motor terminals tm1 to tm3 face each other. By fitting the motor stator 5c into the frame 5a so that the connecting portion 5b is connected in-slot to the frame 5a, the protruding portions 5r of the motor terminals tm1 to tm3 of the motor stator 5c are connected to the protruding portions of the resolver case 5u. It is integrated with the engaging groove 5y formed in 5x and the extension 5s engaged with the engaging groove 5z.

In this state, the length of the extension portion 5s is set so that the terminal portions 5d of the motor terminals tm1 to tm3 are flush with the end surface of the protruding portion 5x slightly behind the end surface of the mounting flange 5n.
By constructing the electric motor 5 with such an arrangement of components, the displacement of the axial position between the resolver stator 5v and the resolver rotor 5w due to assembly error, accuracy of each component, difference in linear expansion coefficient, etc. is suppressed, and detection accuracy is improved. Prevents the decline.

  A female spline is formed on an end surface protruding from the connecting portion of the output shaft 5f of the electric motor 5, and this female spline is a worm with a worm 11 attached when the electric motor 5 is assembled to the reduction gear box 4. Since the shaft coupling can be formed simply by fitting to the male spline formed on the shaft 11a, the number of steps is small and the reliability is high, so that the shaft coupling is suitably used for the electric power steering apparatus.

  However, the fitting between the splines cannot be performed unless the phases of the large and troughs are not matched, and when the electric motor 5 is assembled, the connecting portion 5b is kept until the phases of the splines match. Rotate the connecting portion 5b so that the phase of the through hole of the connecting portion 5b and the tap hole of the motor mounting portion 17 coincide with each other when it is pressed against the worm shaft 11a while being arbitrarily rotated in the circumferential direction. After that, it is necessary to push in until the end surface of the connecting portion 5b comes into contact with the end surface of the motor mounting portion 17.

When inserting the resolver terminals tr1 to tr3 into spring contact terminals 19i to 19k of the control unit 19 to be described later, it is necessary to avoid that the splines come off. Therefore, in this embodiment, the fitting length between the splines is set longer than the protruding length from the end face of the connecting portion 5b in the resolver terminals tr1 to tr3.
As a result, it is possible to rotate the connecting portion 5b in a state where the splines are shallowly fitted to each other so that the phases of the resolver terminals tr1 to tr3 and the insertion ports of the spring contact terminals 19i to 19k coincide with each other. Although used, a wire harness for signal transmission between the resolver terminals tr1 to tr3 and the spring contact terminals 19i to 19k can be omitted.

  Further, as shown in FIG. 7, the control unit 19 is made of, for example, aluminum having a good thermal conductivity mounted on the control unit mounting portion 20 of the reduction gear box 4, in which a power module board, a control board, and the like are stacked. The housing 19a has a substantially rectangular parallelepiped shape that is open on the side opposite to the control unit mounting portion 20 formed by casting a conductive material, and a lid 19b that closes the open end surface of the housing 19a. Here, although not shown in the figure, a packing is provided between the housing 19a and the lid 19b to enhance dustproof and dripproof properties. The lid 19b is provided with an adjustment window 19c, and a circuit board-like torque sensor signal processing circuit can be configured without removing the lid 19b. As shown in FIG. 3, when the control unit 19 is assembled to the reduction gear box 4 in a state before the electric motor 5 is assembled to the reduction gear box 4, the torque sensor signal circuit is calibrated to It can be adjusted accurately without being affected by the motor. The adjustment window 19c is sealed with a sealing sticker (not shown) after calibration of the torque sensor signal processing circuit.

  Spring contact terminals 19e to 19h that are clamped by a spring force when the external connection terminals 15c to 15f of the torque sensor 15 are inserted into the lower end portion of the seat surface 19d that is mounted on the control unit mounting portion 20 of the housing 19a. In addition, the screw terminals tc1 to tc3 that come into contact with the motor terminals tm1 to tm3 and the resolver terminals tr1 to tr3 of the resolver 5h are inserted into the end face on the side facing the electric motor 5 and springs are sandwiched by the spring force. Contact terminals 19i to 19k are provided.

Further, the power terminal 19m and the vehicle body side control device (ECU) and, for example, a CAN (Controller Area Network) are provided on the end surface opposite to the end surface on which the screw terminals tc1 to tc3 and the spring contact terminals 19i to 19k are disposed. ) An ECU connection terminal 19n to be connected by communication is provided.
As shown in FIG. 2, the control unit 19 has a seating surface 19d on the control unit mounting portion 20 side, the seating surface 19d has a high thermal conductivity, and has a notch at a position facing the spring contact terminals 19e to 19h. The torque sensor is mounted on the control unit mounting portion 20 of the reduction gear box 4 while the lower surface of the casing 19a is in contact with the guide surface 22 from the direction perpendicular to the control unit mounting portion 20 with the heat sheet 23 in contact therewith. Fifteen external connection terminals 15c to 15f are inserted into the spring contact terminals 19e to 19h and sandwiched by the spring force.

In this state, the housing 19a and the control unit mounting portion 20 are screwed to complete the mounting of the control unit 19 to the control unit mounting portion 20 as shown in FIG.
Thus, the electrical connection between the external connection terminals 15c to 15f of the torque sensor and the spring contact terminals 19e to 19h can be achieved simply by mounting the control unit 19 from the vertical direction with respect to the control unit mounting portion 20 of the reduction gear box 4. Since the control unit 19 can be assembled to the reduction gear box 4 without removing the cover 19b of the control unit 19, the man-hour can be reduced and a wire for transmitting a torque sensor signal can be obtained. The harness can also be omitted.

As shown in FIG. 3, when the control unit 19 is assembled to the control unit mounting portion 20 of the reduction gear box 4, the screw terminals tc1 to tc3 and the spring contact terminals 19i to 19k formed on the housing 19a. Is slightly protruded from the motor mounting portion 17 in parallel with the motor mounting portion 17 of the reduction gear box 4.
In the assembled state of the control unit 19, as shown in FIG. 2, the electric motor 5 is aligned with the motor mounting portion 17 of the reduction gear box 4 so that the axis of the worm shaft 11a coincides with the axis of the electric motor 5. By mounting the motor terminals tm1 to tm3 and the resolver terminals tr1 to tr4 so as to face the screw terminals tc1 to tc3 and the spring contact terminals 19i to 19k, the terminal portions 5t of the motor terminals tm1 to tm3 are screwed terminals. The resolver terminals tr1 to tr3 are in contact with tc1 to tc3 and are inserted into the spring contact terminals 19i to 19k and sandwiched therebetween.

In this state, the motor mounting portion 17 and the mounting flange 5n in the connecting portion 5b of the electric motor 5 are bolted, and the motor terminals tm1 to tm3 are screwed to the screw terminals tc1 to tc3, as shown in FIG. Thus, the assembly of the electric motor 5 to the reduction gear box 4 is completed.
Thus, the motor terminals tm1 to tm3 and the screw terminals tc1 to tc3 can be brought into contact with each other simply by mounting the electric motor 5 on the motor mounting portion 17 of the reduction gear box 4 from the direction perpendicular to the mounting surface. The motor terminals tm1 to tm3 and the screw terminals tc1 to tc3 can be directly connected without going through the wire harness, and the electrical connection is made by being firmly and surely contacted by the screw axial force. Wiring loss can be reduced, and variations in contact resistance can be suppressed.

  Further, since the motor terminals tm1 to tm3 are bent in a plurality of stages from the projecting part 5r, the extension part 5s and the terminal part 5t, the assembly error between the electric motor 5 and the control unit 19, the accuracy of each part and the line It is possible to prevent an excessive stress from being applied to the connecting portions of the screw terminals tc1 to tc3 and the motor terminals tm1 to tm3 and the bus bar 5p of the control unit 19 due to a difference in expansion coefficient.

Moreover, since the motor terminals tm1 to tm3 are arranged on the connecting portion 5b side together with the substantially annular bus bar connecting the end of the motor coil wound around the motor stator 5c, the motor terminals tm1 to tm3 are shortened. Wiring loss can be reduced.
At the same time, the resolver terminals tr1 to tr3 can be inserted and sandwiched between the spring contact terminals 19i to 19k, and the resolver terminals tr1 to tr3 and the spring contact terminals 19i to 19k can be directly connected without a wire harness. Can do.

Next, the assembly operation of the above embodiment will be described.
First, in order to assemble the electric power steering apparatus 1, the torque sensor 15 is extended in the torque sensor housing portion 16 of the reduction gear box 4, and the distal ends of the external connection terminals 15 c to 15 f extend rearward of the vehicle body along the guide surface 22. Place it so that it is fixed.
Next, the control unit 19 is mounted on the control unit mounting portion 20 of the reduction gear box 4. The control unit 19 is mounted from the vertical direction with respect to the control unit mounting unit 20 with the seating surface 19d facing the control unit mounting unit 20 and the heat transfer sheet 23 having high thermal conductivity in contact with the seating surface 19d. This is done by attaching the lower surface of the body 19a to the control unit mounting portion 20 of the reduction gear box 4 from the vertical direction while contacting the lower surface of the body 19a. As described above, the heat transfer for improving the heat transfer between the control unit 19 and the control unit mounting portion 20 by assembling the control unit 19 from the vertical direction with respect to the control unit mounting portion 20 of the reduction gear box 4. The sheet can be easily sandwiched.

  When the control unit 19 is mounted on the control unit mounting portion 20 of the reduction gear box 4, the external connection terminals 15 c to 15 f of the torque sensor 15 are inserted into the spring contact terminals 19 e to 19 h of the control unit 19 at the same time. Therefore, it is not necessary to interpose a wire harness between the external connection terminals 15c to 15f of the torque sensor 15 and the spring contact terminals 19e to 19h, and electrical connection can be reliably performed.

  At this time, the torque sensor 15 is configured only by the torque detection element and is built in the reduction gear box 4, and its signal processing circuit is incorporated in the control unit 19, so that the calibration of the signal processing circuit is performed on the lid 19b. The calibration can be easily performed from the adjustment window 19c, and the signal processing circuit can be calibrated before the electric motor is assembled to the reduction gear box 4, so that accurate calibration can be performed without being influenced by the electric motor 5. It can be performed.

  Further, since the external connection terminals 15c to 15f of the torque sensor 15 are bent in an L shape, the control unit 19 depends on the assembly error between the torque sensor 15 and the control unit 19, the accuracy of each part, the linear expansion coefficient difference, and the like. It is possible to avoid applying excessive stress to the joints between the spring contact terminals 19e to 19h and the external connection terminals 15c to 15f of the torque sensor 15 and the torque sensor 15, and the durability can be improved.

  After that, as described above, the electric motor 5 assembled in the state of FIG. 5 is brought into alignment with the central axis of the worm shaft 11 a and the central axis of the electric motor 5 to the motor mounting portion 17 adjacent to the control unit 19 of the reduction gear box 4. In addition, the motor terminals tm1 to tm3 and the resolver terminals tr1 to tr3 are brought close to the end face of the motor mounting portion 17 in a direction perpendicular to the screw terminals tc1 to tc3 and the spring contact terminals 19i to 19k of the control unit 19. .

  At this time, first, the female spline formed at the tip of the output shaft 5f and the male spline formed on the worm shaft 11a come into contact with each other, and the female spline and the male spline are rotated while the electric motor 5 is rotated so as to match the phases of both. Fit a predetermined length. In this state, the motor terminals tm1 to tm3 and the resolver terminals tr1 to tr3 are opposed to the screw terminals tc1 to tc3 and the spring contact terminals 19i to 19k of the control unit 19, and the mounting flange 5n of the connecting portion 5b and the motor mounting portion 17 are connected. By pushing the electric motor 5 with the flange portion facing each other, the spigot portion 5o of the connecting portion 5b of the electric motor 5 is in-line coupled to the motor mounting portion 17, and the end surface of the connecting portion 5b and the end surface of the motor mounting portion 17 are connected. And contact.

In this state, first, the resolver terminals tr1 to tr3 are inserted into the insertion ports of the spring contact terminals 19i to 19k of the control unit 19, and then the terminal portions 5t of the motor terminals tm1 to tm3 are screwed terminals tc1 to tc1 of the control unit 19. Contact tc3.
In this state, the mounting flange 5n of the connecting portion 5b and the flange portion 17a of the motor mounting portion 17 are bolted, and the terminal portions 5t of the motor terminals tm1 to tm3 and the screw terminals tc1 to tc3 of the control unit 19 are screwed. Stop.

  In this way, the motor terminals tm1 to tm3 are brought into contact with the screw terminals tc1 to tc3 of the control unit 19 only by mounting the electric motor 5 on the motor mounting portion 17 of the reduction gear box 4 from the direction perpendicular to the end face thereof. The resolver terminals tr1 to tr3 are inserted into the spring contact terminals 19i to 19k of the control unit 19 to be electrically connected to each other, so that the number of connecting steps can be reduced.

  At this time, since the motor terminals tm1 to tm3 and the screw terminals tc1 to tc3 are coupled by screwing, the coupling between the two can be performed firmly and surely to suppress variations in contact resistance, and the resolver terminal tr1. -Tr3 and the spring contact terminals 19i-19k can be reliably coupled by the spring force, and since both are directly electrically connected without interposing a wire harness, wiring loss can be reduced. At the same time, the cost can be reduced.

  And since the brushless motor is applied as the electric motor 5, there is no loss due to the contact resistance of the brush, and in combination with the fact that the wire harness for energizing the motor is omitted, only one of the low-loss methods is used. Then, the electric power steering device can be applied to a large vehicle that requires a large steering assist thrust that cannot be achieved. When the present invention is applied to a medium-sized or small-sized vehicle without being applied to a large vehicle, since the loss is small, the electric motor 5 and the control unit can be made smaller than the current state.

  Further, since the control unit 19 is directly attached to the reduction gear box 4 having a large heat capacity, a large surface area and not easily generating a heat source, the heat generated in the control unit 19 can be directly transferred to the reduction gear box 4 efficiently. The heat dissipating fins provided on 19 can be made as small as possible or omitted, and the configuration of the control unit 19 can be reduced in size and weight.

Next, a second embodiment of the present invention will be described with reference to FIG.
In the second embodiment, the motor terminal is also extended in the direction perpendicular to the end face of the connecting portion, like the resolver terminal.
That is, in the second embodiment, as shown in FIG. 8, the terminal portions 5t of the motor terminals tm1 to tm3 in the first embodiment described above are formed on the extension line of the extension portion 5s, and the resolver terminals tr1 to tr1 are formed. Similarly to tr3, it extends in the vertical direction with respect to the end face of the connecting portion 5b, and according to this, the screw terminals tc1 to tc3 of the control unit 19 are omitted and changed to these to form spring contact terminals ts1 to ts3. Except for this, the configuration is the same as that of the first embodiment described above, and the same reference numerals are given to the corresponding parts to those in FIGS. 1 to 3, and the detailed description thereof will be omitted.

  According to the second embodiment, when the electric motor 5 is mounted on the motor mounting portion 17 of the reduction gear box 4 from the direction perpendicular to its end surface, the motor terminals tm1 to tm3 are also springs in the same manner as the resolver terminals tr1 to tr3. Since the contact terminals ts1 to ts3 are inserted and sandwiched, the screwing step of the motor terminals tm1 to tm3 in the first embodiment described above can be omitted. In addition, since a structure for withstanding the reaction force of the tightening torque in the screwing process is not required, the cost can be further reduced. Furthermore, since the motor terminals that have to be thickened to cope with large currents are not mechanically fixed, it is possible to relieve stress caused by assembly errors, accuracy of each part, and motor heat generation. Can increase the sex.

  In the first and second embodiments, the case where the present invention is applied to a column assist type electric power steering apparatus has been described. However, the present invention is not limited to this, and a pinion assist type or a rack assist type is not limited thereto. Even when applied to the electric power steering apparatus, the same effect as described above can be obtained. In this case, since it is disposed in the engine room, a sealing mechanism for waterproofing and dustproofing may be provided at the contact between the control unit 19 and the electric motor 5 and the contact between the control unit 19 and the torque sensor.

Moreover, in the said 1st and 2nd embodiment, although the case where a screwing terminal and a spring contact terminal were applied as a contact of motor terminals tm1-tm3 and the control unit 19 was demonstrated, it is limited to these. Instead, it may be electrically connected to at least one of welding and soldering.
Furthermore, in the said embodiment, although the screwing terminal and the spring contact terminal were applied about the motor terminals tm1-tm3 and only the spring contact terminal was applied about the resolver terminals tr1-tr3, motor terminal tm1- You may make it mix a screw terminal and a spring control terminal about each of tm3 and resolver terminal tr1-tr3.

Furthermore, a screw terminal or a spring contact terminal may be provided on the electric motor 5 side, and motor terminals tm1 to tm3 and resolver terminals tr1 to tr3 may be provided on the control unit side.
Furthermore, in the first and second embodiments, the case where the surface magnet type motor rotor 5g is applied as the electric motor 5 has been described. However, the present invention is not limited to this, and a magnet embedded type (IPM). Other types of brushless motors such as brushless motors and induction motors can be applied.

  In the above embodiment, the case where the female spline is formed on the output shaft 5f of the electric motor 5 and the male spline is formed on the worm shaft 11a has been described. However, the output shaft 5f of the electric motor 5 is reversely related. A male spline may be formed on the worm shaft 11a, and a female spline may be formed on the worm shaft 11a. Further, serration fitting may be applied instead of spline fitting.

Further, when the electric motor 5 is assembled to the reduction gear box 4, when the splines are fitted together shallowly and the terminal is covered with a jig that is pulled out in the radial direction of the connecting portion 5b, the terminals are connected during the spline fitting. It can be prevented from being bent or damaged.
Furthermore, in the first and second embodiments, the case where the control unit 19 is mounted on the control unit mounting portion 20 via the heat transfer sheet 23 has been described. However, the heat transfer sheet 23 is omitted. May be.

  In the first and second embodiments, the case where a three-phase brushless motor is applied has been described. However, the present invention is not limited to this, and a four-phase or more multiphase brushless motor is applied. In this case, the number of motor terminals may be the number corresponding to the number of phases. Similarly, a three-phase resolver signal having a phase difference of 120 degrees may be output from the resolver 5h. In this case, four pairs of resolver terminals including those for excitation signals may be provided.

  In the first and second embodiments, the torque sensor 15 is configured by only the torque detection element and the signal processing circuit is built in the control unit 19, but the present invention is not limited to this. The torque sensor 15 includes torque detection elements 15a and 15b and a signal processing circuit thereof, and the torque detection elements 15a and 15b are provided in the reduction gear box 4 and are electrically connected to the torque detection elements 15a and 15b. A signal processing circuit may be provided. In this case, the signal processing circuit can be calibrated in the state of the reduction gearbox 4 alone, and the signal processing circuit is not affected by the electric motor. Calibration can be performed. Then, when the electric motor 5 is assembled to the reduction gear box 4 in which the signal processing circuit of the torque sensor 15 has been calibrated, and then the control unit 19 is assembled, the electrical connection between the control unit 19 and the torque detection element and The electrical connection between the control unit 19 and the electric motor 5 can be performed, the assembly work can be easily performed, and the assembly process can be simplified without degrading the accuracy of the torque sensor.

1 is a perspective view showing an embodiment of an electric power steering device according to the present invention. FIG. 2 is an exploded perspective view of FIG. 1. It is a perspective view which shows the state which removed the electric motor. It is a longitudinal cross-sectional view of a reduction gear box. It is a perspective view which shows an electric motor. It is a disassembled perspective view of an electric motor. It is a perspective view which shows a control unit, Comprising: (a) is a perspective view of the front side, (b) is a perspective view of the back side. It is a disassembled perspective view before assembling the electric motor which shows the 2nd Embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Electric power steering apparatus, 2 ... Steering shaft, 3 ... Steering column, 4 ... Reduction gear box, 5 ... Electric motor, 5a ... Frame, 5b ... Connection part, 5c ... Motor stator, 5g ... Motor rotor, 5h ... Resolver, 5n ... Mounting flange, 5u ... Resolver case, 5v ... Resolver stator, 5w ... Resolver rotor, tm1-tm3 ... Motor terminal, tr1-tr3 ... Resolver terminal, 6 ... Upper mounting bracket, 7 ... Lower mounting bracket, 11 ... Worm, DESCRIPTION OF SYMBOLS 11a ... Worm shaft, 12 ... Worm storage part, 13 ... Worm wheel, 14 ... Worm wheel storage part, 15 ... Torque sensor, 15c-15f ... External connection terminal, 16 ... Torque sensor storage part, 17 ... Motor mounting part, 18 ... Column mounting part, 19 ... Control unit, 19i to 19k Spring contact terminals, TC1 to TC3 ... screwing terminals, Ts1～ts3 ... spring contact terminal, 20 ... control unit mounting section, 21 ... guide surface, 22 ... opening, 23 ... heat transfer sheet

Claims (21)

A steering column having a steering shaft to which a steering torque is transmitted; a torque sensor for detecting the steering torque; an electric motor for transmitting a steering assist force to the steering shaft via a reduction mechanism in a reduction gear box; An electric power steering apparatus comprising a control unit for driving and controlling the electric motor based on a steering torque detected by a torque sensor,
The torque sensor, the electric motor, and the control unit are assembled to the reduction gear box, and the electric motor is composed of a brushless motor having an electrical contact for external connection connected to a motor coil, and the control unit Has an electrical contact for connecting to the electrical contact of the electric motor, and the electrical contact of the electric motor and the electrical contact of the control unit assembled the electric motor and the control unit to the reduction gear box. Further, the control unit is mounted on the reduction gear box so that heat generated when energizing the electric motor is directly transferred to the reduction gear box. An electric power steering device.   The electric motor includes a rotor rotation angle detector that detects a rotor rotation angle disposed on the output shaft side and has an electrical contact for external connection, and the control unit includes a rotor rotation angle detector. An electrical contact connected to the electrical contact, and the electrical contact of the rotor rotation angle detector and the electrical contact of the control unit are in a state where the electric motor and the control unit are assembled to the reduction gear box. The electric power steering apparatus according to claim 1, wherein the electric power steering apparatus is disposed in a portion directly connected to each other.   The electric motor includes a connecting portion that is fitted to a motor mounting surface of the reduction gear box and is bolted, and the rotor rotation angle detector is incorporated in the connecting portion. An electrical contact is formed to project in at least one of a vertical direction and a horizontal direction with respect to the end surface on the reduction gear box side, and an electrical contact of the rotor rotation angle detector is vertical and horizontal with respect to the end surface on the reduction gear box side. The electric power steering apparatus according to claim 2, wherein the electric power steering apparatus is formed to protrude in at least one of directions.   The torque sensor includes an electrical contact for external connection connected to either the torque detection element or its signal processing circuit, and the control unit has an electrical contact connected to the electrical contact of the torque sensor. And the electrical contact of the torque sensor and the electrical contact of the control unit are arranged at a portion where they are directly connected to each other in a state where the torque sensor and the control unit are assembled to the reduction gear box. The electric power steering device according to any one of claims 1 to 3.   5. The electric power according to claim 4, wherein the torque sensor is formed so as to protrude in a direction perpendicular to a mounting surface of the control unit in a state where the electrical contact is assembled to the reduction gear box. Steering device.   6. The reduction mechanism according to claim 1, wherein the reduction mechanism comprises a worm reduction gear, and the control unit mounting surface of the reduction gear box is a plane perpendicular to the worm wheel axis direction. The electric power steering device according to claim 1.   The electric power steering apparatus according to any one of claims 1 to 3, wherein the control unit has a shape in a width direction that is symmetrical with respect to an axis of the electric motor.   2. The electrical contact of the control unit with respect to the electric motor is constituted by a screw terminal that contacts the electrical contact of the electric motor by a screw axial force and is electrically connected. The electric power steering device according to any one of 1 to 5.   The electrical contact of the control unit with respect to the electric motor is constituted by a spring contact terminal that contacts the electrical contact of the electric motor by a spring pressure and is electrically connected, and an insertion port of the spring contact terminal is the control port. The electric power steering apparatus according to any one of claims 1 to 5, wherein the electric power steering apparatus is opened toward a motor mounting surface of the reduction gear box in a state where the unit is assembled to the reduction gear box.   6. The electrical contact of the control unit with respect to the electric motor is electrically connected to the electrical contact of the electric motor by welding or soldering. The electric power steering device according to the item.   An electrical contact of the control unit with respect to the rotor rotation angle detector is constituted by a spring contact terminal that is brought into electrical connection by contact with the electrical contact of the rotor angle detector by a spring pressure. The electric power steering device according to claim 2 or 3.   The electrical contact of the control unit to the rotor rotation angle detector is electrically connected to the electrical contact of the rotor rotation angle detector by welding or soldering. Or the electric power steering apparatus according to 3;   The electrical contact with respect to the torque sensor of the control unit is configured by a spring contact terminal that is brought into electrical contact with the electrical contact of the torque sensor by spring pressure. 5. The electric power steering device according to 5.   The electric contact according to claim 4 or 5, wherein the electrical contact of the control unit with respect to the torque sensor is electrically connected to the electrical contact of the torque sensor by either welding or soldering. Power steering device.   The electric power steering device according to any one of claims 1 to 14, wherein a sealing mechanism for waterproofing and dust-proofing is provided for an electrical contact of the control unit with respect to the electric motor.   The electric power steering according to any one of claims 1 to 15, wherein the electrical contact of the control unit with respect to the rotor rotation angle detector is provided with a sealing mechanism for waterproofing and dustproofing. apparatus.   The electric power steering apparatus according to any one of claims 1 to 16, wherein a sealing mechanism for waterproofing and dust-proofing is provided for an electrical contact of the control unit with the torque sensor.   2. The control unit mounting surface for mounting the control unit is formed in a portion of the speed reduction gear box, in which the speed reduction mechanism is constituted by a worm reduction gear, and the control unit is mounted on a portion of the reduction gear box. The electric power steering device according to any one of 17.   The speed reduction mechanism is constituted by a worm speed reducer, and the worm shaft and the output shaft of the electric motor are spline-coupled, and the coupling length thereof is an electric contact of the electric motor and an electric contact of the rotor rotation angle detector. The electric power steering apparatus according to claim 3, wherein the electric power steering apparatus is set to be longer than a protruding length from the end face of the mounting flange. A steering column having a steering shaft to which a steering torque is transmitted; a torque sensor for detecting the steering torque; an electric motor for transmitting a steering assist force to the steering shaft via a reduction mechanism in a reduction gear box; A method for assembling an electric power steering device, wherein a control unit for driving and controlling the electric motor based on a steering torque detected by a torque sensor is assembled to the reduction gear box,
The torque sensor includes a torque detection element, and the control unit includes a signal processing circuit that processes a steering torque detection signal detected by the torque detection element, and the torque sensor is included in the reduction gear box, The control unit is assembled to the reduction gear box in which the torque sensor is built, and the torque detection element and the control unit are electrically connected, and then the electric motor is assembled to the reduction gear box, An electric power steering apparatus assembling method, wherein electrical connection with an electric motor is performed. A steering column having a steering shaft to which a steering torque is transmitted; a torque sensor for detecting the steering torque; an electric motor for transmitting a steering assist force to the steering shaft via a reduction mechanism in a reduction gear box; A method for assembling an electric power steering device, wherein a control unit for driving and controlling the electric motor based on a steering torque detected by a torque sensor is assembled to the reduction gear box,
The torque sensor includes a torque detection element and a signal processing circuit that processes a steering torque detection signal thereof. The torque detection element and the signal processing circuit are assembled to the reduction gear box, and then the reduction gear box. The electric motor is assembled, and then the control unit is assembled to the reduction gear box, so that the electrical connection between the control unit and the torque detection element and the electrical connection between the control unit and the electric motor are performed. A method of assembling an electric power steering device.

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