JP5251939B2 - Electric power steering device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electric power steering device capable of reliably preventing ingress of conductive foreign matters or the like which adversely affect the sensing operation of a torque sensor by an inexpensive structure. <P>SOLUTION: A first engaging groove 33a along the axial direction of a steering shaft is formed in a side face directed to the vehicle width direction of a unit engagement part 20b, and a second engaging groove extending in the vehicle width direction is formed in a side face directed to the longitudinal direction of a vehicle of the unit engagement part 20b. A cover is slidably moved in the longitudinal direction of a vehicle while fitting end plate parts 35b, 36b forming a cutout part 28a of a cover plate part 28 into the first engaging groove 33a. Then, the cover plate part surrounds an opening part while the end plate parts are fitted in the first engaging groove 33a and the second engaging groove. <P>COPYRIGHT: (C)2012,JPO&amp;INPIT

Description

  The present invention provides a control unit including an electric motor that transmits a steering assist force to a steering shaft to which a steering torque is transmitted via a speed reduction mechanism in a speed reduction gear box, and a control board on which a control circuit that drives and controls the electric motor is mounted. And an electric power steering apparatus.

  As a conventional electric power steering device, for example, an electric motor is accommodated in a rack case or a reduction gear box in which a rack shaft is slidably accommodated or mounted, and a control board for controlling driving of the electric motor is accommodated. The housing is formed in a rack case or a reduction gear box, and when the control board inserted from the opening is brought into contact with a mounting boss formed on the bottom facing the opening of the housing, the electric motor projects from the electric motor. There has been proposed an electric power steering device in which board connection terminals provided on the control board are in contact with each other and electrically connected to the motor side connection terminals, and an electric connection line is provided between the electric motor and the control board. By attaching directly without insertion, electrical noise is applied with the shortest wiring length between the electric motor and the control board. It is possible to prevent, it is possible to reduce electrical losses by reducing the wiring resistance.

  However, it is necessary to input a torque detection value of a torque sensor that detects torque transmitted to the steering shaft to a control board that controls the electric motor. It is installed on the wheel side, and it is necessary to provide a long connection cable between this torque sensor and the control board. Electric noise is added to this connection cable, and electrical resistance increases, resulting in an increase in electrical loss. .

  Therefore, a mounting surface is formed on the outer periphery of the reduction gear box, and a control unit incorporating a control board is mounted on the mounting surface, and a plurality of external connection terminals connected to a torque sensor built in the reduction gear box. Projecting to the outside from the opening provided so as to open at the mounting surface in communication with the position where the torque sensor is housed, and inserted into a plurality of through holes provided on the control board of the control unit mounted on the mounting surface In addition, we have developed an electric power steering device that has a structure in which both are electrically connected by soldering, and the connection distance between the control board and the torque sensor is minimized to prevent electrical noise and electrical loss between the two. (For example, refer to Patent Document 1).

JP 2009-023459 A

However, as described above, the mounting surface of the reduction gear box to which the control unit is mounted is provided with an opening communicating with the position where the torque sensor is accommodated, and the outside of the torque sensor connected to the control board from this opening. If the connection terminal is protruded and connected to the through hole of the control board, conductive foreign matter enters from the gap between the reduction gearbox mounting surface and the control unit mounting surface, and is connected to any external part of the torque sensor. There is a possibility that the connection terminals come into contact with each other, the torque sensor outputs an erroneous torque detection value, and the electric motor performs erroneous drive control.
Here, it is difficult in terms of manufacturing cost to form the mounting surface and the mounting surface with high accuracy so that there is no gap between the mounting surface of the reduction gear box and the mounting surface of the control unit.

  Therefore, the present invention has been made paying attention to the unsolved problems of the above-described conventional example, projecting the external connection terminal of the torque sensor from the gear box mounting surface to the outside, and connecting it to the control board of the control unit, To provide an electric power steering device that can reliably prevent intrusion of conductive foreign matters and the like that adversely affect the detection operation of a torque sensor with an inexpensive structure even when the gear box mounting surface and the control unit are opposed to each other. It is an object.

  In order to achieve the above object, an electric power steering apparatus according to claim 1 of the present invention is an electric motor that transmits a steering assist force to a steering shaft to which a steering torque is transmitted via a reduction mechanism in a reduction gear box. And a control unit including a control board on which a control circuit for driving and controlling the electric motor is mounted, and the control board of the control unit is accommodated in a unit engaging portion formed to protrude from the outer periphery of the reduction gear box An opening formed with a plurality of external connection terminals connected to a torque sensor housed in the reduction gear box at the top of the unit engaging portion, with the cover plate portion of the cover to be mounted close to the control unit And projecting each of the plurality of external connection terminals through a notch formed in the cover plate portion, to the control board In the electric power steering apparatus that is electrically connected directly to the plurality of board-side terminals, a first engagement groove is formed on the side surface of the unit engagement portion facing the vehicle width direction along the axial direction of the steering shaft. A second engagement groove extending in the vehicle width direction is formed on a side surface of the unit engagement portion facing the vehicle longitudinal direction, and the notch portion of the cover plate portion is formed in the first engagement groove. The cover plate is inserted into the first engagement groove and the second engagement groove by sliding the cover in the vehicle front-rear direction while fitting the end plate portion. The part surrounds the opening.

  According to this invention, the end plate part which forms the notch part of the cover is fitted and engaged with the first engagement groove and the second engagement groove formed on the side surface of the unit engagement part. Since the opening is surrounded by the plate portion, intrusion of conductive foreign matter generated on the outer peripheral side of the reduction gear box is blocked. Further, it is possible to prevent a large foreign object (for example, a screw, a pebble, etc.) from entering the opening side.

According to a second aspect of the present invention, in the electric power steering apparatus according to the first aspect, the first engagement groove, the second engagement groove, and the end plate portion are fitted and engaged with each other. Sometimes, a pressing means for pressing one against the other was provided.
According to a third aspect of the present invention, in the electric power steering apparatus according to the second aspect, the pressing means protrudes from a part of the end plate portion, and the first engagement groove and the second engagement groove It is a protrusion part which contacts, pressing an inner wall.

According to a fourth aspect of the present invention, in the electric power steering apparatus according to the second aspect, the pressing means protrudes from a part of the inner walls of the first engagement groove and the second engagement groove, and the end plate It is a projection part which contacts, pressing the end surface of a part.
According to the second to fourth aspects of the present invention, even if the motor vibration is transmitted from the electric motor mounted on the reduction gear box to the control unit, the cover and the unit engaging portion are engaged via the pressing means. Therefore, it is possible to prevent an unpleasant sound such as a chatter sound from being generated on the cover.

Furthermore, the invention according to claim 5 is the electric power steering apparatus according to any one of claims 1 to 4, wherein the second engagement groove is formed on a side surface of the unit engagement portion facing the vehicle rear. The cover is moved from the rear of the vehicle to engage the cover plate portion with the unit engaging portion.
According to the present invention, the cover can be engaged with the unit engaging portion from the rear side of the vehicle having a large mounting space, so that the assembling property of the control unit is improved.

  Further, the steering column of the electric power steering apparatus is arranged with an upward inclination toward the rear of the vehicle, and water droplets attached to the cover plate portion flow toward the unit engagement portion 20b in the front of the vehicle. However, in the present invention, the end plate portion forming the notch portion of the cover plate portion is provided on the side surface (the first engagement groove and the first engagement groove) below the position where the opening portion is open. The water droplets that have been engaged at the engagement position of the two engagement grooves and have reached the end plate part do not rise to the upper part of the side surface and flow into the opening part.

  According to the electric power steering apparatus according to the present invention, the end plate portion forming the notch portion of the cover is fitted into the first engagement groove and the second engagement groove formed on the side surface of the unit engagement portion. Since the cover plate portion surrounds the opening portion, it is possible to reliably prevent conductive foreign matters and large foreign matters from entering with an inexpensive structure.

It is the perspective view shown from the right direction at the time of applying one Embodiment of the electric power steering device which concerns on this invention to a right-hand drive vehicle. It is a longitudinal cross-sectional view which shows the principal part of the reduction gear box which comprises an electric power steering apparatus. It is the perspective view which showed the reduction gear box before mounting | wearing with a control unit from the vehicle width direction. It is the figure which expanded and showed the unit engaging part of the reduction gear box. FIG. 5 is a cross-sectional view taken along line AA in FIG. 4. FIG. 5 is a cross-sectional view taken along line B-B in FIG. 4. It is a disassembled perspective view of a control unit. It is CC sectional view taken on the line of FIG. It is DD sectional view taken on the line of FIG. It is the schematic which showed the contact state of the cover board part and unit engagement part of 1st Embodiment which concerns on this invention from the vehicle rear. It is the schematic which showed the contact state of the cover board part and unit engagement part of 1st Embodiment which concerns on this invention from the vehicle width direction. It is a figure which shows the shape of the opening part formed in the cover board part of 2nd Embodiment which concerns on this invention. It is a figure which shows the shape of the unit engaging part of 3rd Embodiment which concerns on this invention.

Hereinafter, the best mode for carrying out the present invention (hereinafter referred to as an embodiment) will be described in detail with reference to the drawings.
FIG. 1 is a perspective view showing an electric power steering apparatus according to the present invention from the front of a vehicle.
Reference numeral 1 in FIG. 1 denotes a column-type electric power steering device. 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 whose axial direction is extended in a direction orthogonal to the axial direction of the steering shaft 2.

The steering column 3 has a double tube structure of an inner tube 3a and an outer tube 3b. The inner tube 3 a 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 of a mounting plate portion 7a attached to the vehicle body side member, and a pair of support plate portions 7b extending in parallel from the lower surface of the mounting plate portion 7a in the left-right direction with a predetermined interval. . And the lower end of the support plate part 7b is rotatably connected to the support part 4b integrally formed in the vehicle body front side of the reduction gear box 4 via the pivot 7c.

  The upper mounting bracket 6 is formed on a pair of flanges 6a, a pair of support plate portions 6c fixed to the lower ends of the flanges 6a and spaced apart in the left-right (vehicle width) direction, and the pair of support plate portions 6c. And a tilt mechanism 6 d that supports the outer tube 3 b of the steering column 3. A slit 6a1 is formed in the flange 6a, and a release capsule 6b is fitted in the slit 6a1. A bolt through hole 6b1 is formed in the release capsule 6b, and a fixing bolt (not shown) that penetrates the bolt through hole 6b1 from below the release capsule 6b is screwed into a vehicle body side member (not shown). The flange 6a is attached to the vehicle body side member.

Then, by tilting the tilt lever 6g of the tilt mechanism 6d and releasing the support state of the outer tube 3b, the tilt position of the steering column 3 can be adjusted up and down around the pivot 7c of the lower mounting bracket 7. .
As shown in FIG. 2, the steering shaft 2 has an input shaft 2a whose upper end is connected to the steering wheel, and an output shaft 2c that covers the torsion bar 2b connected to the lower end of the input shaft 2a via the torsion bar 2b. It consists of

  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. As shown in FIG. 2, the reduction gear box 4 includes a worm storage portion 12 that stores a worm 11 connected to an output shaft (not shown) of the electric motor 5, and a central shaft below the worm storage portion 12. A worm wheel storage portion 14 for storing a worm wheel 13 having a central axis perpendicular to the worm 11 and meshing with the worm 11, and a torque sensor 15 integrally and coaxially connected to the rear side of the vehicle body of the worm wheel storage portion 14 are stored. A torque sensor housing portion 16, a motor mounting portion 17 for mounting the electric motor 5 formed on the open end surface of the worm housing portion 12, and a cylindrical column mounting portion 18 formed at the rear end of the vehicle body of the torque sensor housing portion 16. And a control unit mounting portion 20 for mounting a control unit 19 formed over part of the worm storage portion 12 and the worm wheel storage portion 14. It is equipped with a. The front end portion of the vehicle body of the steering column 3 is externally fitted and connected to the column mounting portion 18 of the reduction gear box 4.

  Here, as shown in FIG. 2, 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 detects a pair of steering torques transmitted to the steering shaft 2. The external connection terminals 15c are configured to be detected by the coils 15a and 15b and project outwardly in parallel to the direction perpendicular to the central axis of the steering column 3 at the start and end of winding of the pair of detection coils 15a and 15b, respectively. 15d and 15e, 15f are connected, and the protruding portions of these external connection terminals 15c to 15f are bent in parallel with the central axis of the steering column 3 at the central portion to form an L shape.

  As shown in FIG. 1, the electric motor 5 has a connection terminal (not shown) at a position close to and facing the control unit 19 mounted on the control unit mounting portion 20 at a position close to the mounting flange 5b. Although not specifically shown, each of the connection terminals is insulated from each other in a synthetic resin brush support body having an armature insertion hole at the bottom center, and is individually connected to two sets of brushes. The arc-shaped connection terminals are integrally formed at opposite ends.

As shown in FIG. 3, the control unit mounting portion 20 formed in the reduction gear box 4 includes a flat mounting surface 20a formed by the worm storage portion 12 and the upper side of the worm wheel storage portion 14 below, and torque. And a unit engagement portion 20b formed to project from the upper surface of the sensor housing portion 16 into a substantially rectangular parallelepiped shape.
An opening 20d that communicates with the internal space of the torque sensor housing 16 that houses the torque sensor 15 is formed at the center in the left-right direction of the unit engaging portion 20b, and passes through the opening 20d. External connection terminals 15c to 15f of the torque sensor 15 are provided so as to protrude above the unit engagement portion 20b.

Further, a frame mounting surface 20c having a narrow width is formed on the vehicle rear end surface of the motor mounting portion 17 at a position parallel to the flat mounting surface 20a and on the vehicle rear side from the flat mounting surface 20a.
Here, as shown in FIGS. 4 to 6, the unit engaging portion 20 b of the control unit mounting portion 20 that protrudes in a substantially rectangular parallelepiped shape from the upper surface of the outer periphery of the torque sensor housing portion 16 has two side surfaces facing the vehicle width direction. Further, a pair of first engagement grooves 33a are formed along the axial direction of the steering shaft 2, and the pair of first engagement grooves 33a extend in the vehicle width direction on the side surfaces facing the rear of the vehicle. A continuous second engagement groove 33b is formed.

On the other hand, as shown in FIG. 7, the control unit 19 mounted on the control unit mounting unit 20 includes a heat radiating plate 21, a power board 22, a rectangular frame 23, a control board 24, and a cover 26. I have.
The heat radiating plate 21 is directly fixed to the flat mounting surface 20a of the control unit mounting portion 20 via heat radiating grease. The power substrate 22 is an integrated circuit 22a, 22b such as an H bridge circuit composed of a power switching element such as a field effect transistor that drives and controls the electric motor 5, and a pulse width modulation circuit that drives the power switching element of the H bridge circuit. Is implemented.

  The control board 24 is attached to the front surface of the frame 23, and has through holes 24a to 24d that are directly inserted through the external connection terminals 15c to 15f of the torque sensor 15. A torque detection value from the torque sensor 15 or a vehicle speed sensor (not shown) is provided. The steering assist current command value is calculated based on the detected vehicle speed value from the vehicle, and the current feedback control is performed based on the steering assist current command value and the detected value of the motor current output to the electric motor 5 to perform the pulse of the power board 22. In addition to the micro control unit (MCU) that controls the steering assist force generated by the electric motor 5 and its peripheral devices by calculating the voltage command value to the width modulation circuit, discrete components 24e such as capacitors, coils, relays, etc. Is implemented.

  The frame 23 is a member that surrounds the power board 22, and includes a rectangular frame-shaped frame body 23 a and a mounting plate portion 23 b that is formed at the left end of the frame body 23 a and is fixed to the frame mounting surface of the reduction gear box 4. A terminal block 23c fixed on the mounting plate 23b and electrically connected to a connection terminal of the electric motor 5 and a female connector 45 fixed to the right end of the frame body 23a are provided. Although not shown, the female connector 45 includes a power connector 45a that is connected to a battery via a male connector for power supply, and a signal connector 45b that is connected to a network such as a CAN that transmits and receives data to / from a control device in each part of the vehicle body. And. The power board 22 and the control board 24 are connected via a connection terminal 22c.

The cover 26 is a metal member capable of blocking electromagnetic waves and protecting internal components. As shown in FIG. 7, the cover 26 has a rectangular first plate portion 27 that covers the control board 24 and the first plate portion 27. Second and third plate portions 28 and 29 extending orthogonally from the edge in the longitudinal direction, and second and third plate portions 28 and 29 from the edge in the short direction of the first plate portion 27 The fourth and fifth plate portions 30 and 31 extending in the same direction and the second plate portion 28 and the fourth and fifth plate portions 30 and 31 are formed in a direction orthogonal to the outside of the cover. And a plurality of fixing pieces 32 having screw insertion holes. Further, the fourth plate portion 30 is formed with a notch 30 a surrounding the outer periphery of the female connector 45.
At the center in the longitudinal direction of the second plate portion 28, a notch portion 28a notched in a gate shape is formed.

8 and 9 show in detail the peripheral shape of the notch 28a described above, and a step 34 protruding outward from the cover 26 is formed at the periphery of the notch 28a.
That is, as shown in FIG. 8, the stepped portion 34 protruding outward from both sides in the longitudinal direction of the second plate portion 28 includes inclined plate portions 35 a and 36 a protruding outward with a predetermined inclination angle, It comprises end plate portions 35b and 36b that extend in parallel with the second plate portion 28 from the tip ends of the inclined plate portions 35a and 36a and form a notch portion 28a.
As shown in FIG. 9, the stepped portion 34 protruding outward from the first plate portion 27 side includes an inclined plate portion 37a protruding outward with a predetermined inclination angle, and the tip of the inclined plate portion 37a. And an end plate portion 37b extending in parallel with the second plate portion 28 to form a notch portion 28a.

Then, the heat radiation plate 21 and the frame 23 of the control unit 19 are fixed to the control unit mounting portion 20 of the reduction gear box 4, and the external connection of the torque sensor 15 protruding from the opening 20 d of the control unit mounting portion 20 of the reduction gear box 4. The terminals 15c to 15f (see FIG. 3) are directly inserted into the through holes 24a to 24d (see FIG. 7) of the control board 24 of the control unit 19 and soldered. Thereafter, the cover 26 is fixed to the control unit mounting portion 20 and the control unit 19 is mounted while moving the cover 26 from the vehicle rear side to the vehicle front side. Further, the terminal block 23 c fixed to the mounting plate portion 23 b of the frame 23 and the connection terminal of the electric motor 5 are electrically connected. The electrically connected terminal block 23c and the connection terminal of the electric motor 5 are covered with a synthetic resin terminal cover denoted by reference numeral 27 in FIG.
The cover plate portion of the present invention corresponds to the second plate portion 28, and the end plate portions of the present invention correspond to the end plate portions 35a, 36b, and 37b.

Next, the operation of the above embodiment will be described.
When power is supplied from the battery to the power board 22 and the control board 24 by turning on an ignition switch (not shown) of the vehicle body, a steering assist control process is executed by the micro control unit (MCU), and the torque sensor 15 and the vehicle speed sensor (not shown) are A steering assist current command value is calculated based on the detected value. A current feedback process is executed based on the steering assist current command value and the motor current detected by the motor current detection unit to calculate a voltage command value. By supplying this voltage command value to the gate drive circuit of the power board 22 and controlling the H bridge circuit, a motor drive current flows through the electric motor 5 and the electric motor 5 needs to be operated in the forward or reverse direction. Drive to generate force.

Therefore, a steering assist force corresponding to the steering torque of the steering wheel is generated from the electric motor 5, and this steering assist force is transmitted to the output of the steering shaft 2 via the worm 11 and the worm wheel 13, whereby the steering wheel Can be steered with a light steering force.
Here, when mounting the control unit 19, as described above, after mounting other parts of the control unit 19 (such as the heat radiation plate 21, the frame 23, and the control board 24) on the control unit mounting portion 20, the cover 26 is attached. It is moved from the vehicle rear side to the vehicle front side and fixed to the control unit mounting portion 20.

  At this time, the end plate portions 35b and 36b formed on the periphery of the notch 28a facing the vehicle width direction of the cover 26 (second plate portion 28) face the vehicle width direction of the unit engaging portion 20b of the reduction gear box 4. It fits in a pair of 1st engaging groove 33a formed in two side surfaces, and slide-moves ahead of a vehicle (refer FIG. 10). And when the front-end | tip of the moving direction of the end plate parts 35b and 36b is located in the vehicle front end of a pair of 1st engagement groove | channel 33a, it is on the periphery of the notch 28a of the cover 26 (1st plate part 37 side). The end plate portion 37b that is formed and faces the front of the vehicle is fitted into a second engagement groove 33b that is formed on a side surface of the unit engagement portion 20b that faces the vehicle rear (see FIG. 11).

The external connection terminals 15c to 15f of the torque sensor 15 pass through the opening 20d, and the conductive foreign matter generated on the outer peripheral side of the reduction gear box 4 is on the opening 20d side where the external connection terminals 15c to 15f are arranged. The end plate portions 35b, 36b, and 37b formed on the peripheral edge of the notch portion 28a of the cover 26 have a pair of first engagement grooves 33a and second engagement formed on the side surfaces of the unit engagement portion 20b. Since the opening 20d is surrounded while fitting into the mating groove 33b, intrusion of conductive foreign matter is blocked.
Accordingly, the conductive foreign matter does not contact any pair of the plurality of external connection terminals 15 c to 15 f of the torque sensor 15, and the torque sensor 15 outputs a normal torque detection value to normalize the electric motor 5. Drive control can be performed.

Further, the end plate portions 35b, 36b, and 37b on the periphery of the notch portion 28a of the cover 26 are fitted into the pair of first engagement grooves 33a and second engagement grooves 33b of the unit engagement portion 20b, and the opening portion 20d. Therefore, it is possible to prevent large foreign matters (for example, screws, pebbles, etc.) from entering the opening 20d side.
Furthermore, since the cover 26 is engaged with the three directions of the unit engaging portion 20b (two directions in the vehicle width direction and one direction on the vehicle rear side), the cover 26 is attached to the control unit mounting portion 20 of the reduction gear box 4. The position shift of the cover 26 can be prevented.

Further, since the cover 26 can be engaged with the unit engaging portion 20b from the vehicle rear side where the mounting space is wide, the assembly of the control unit 19 can be easily performed.
Further, the steering column 3 of the electric power steering apparatus is arranged with an upward inclination toward the rear of the vehicle, and water droplets attached to the lower surface (second plate portion 28) of the cover 26 are unit-engaged in the front of the vehicle. In this embodiment, the end plate portions 35b, 36b, and 37b of the cover 26 are located on the side surface of the unit engaging portion 20b below the position where the opening 20d is open. Water droplets that are engaged in the (first engagement groove 33a, second engagement groove 33b) and transmitted to the end plate portions 35b, 36b, and 37b do not rise to the upper part of the side surface and flow into the opening 20d. .

FIG. 12 shows a second embodiment according to the present invention.
In this embodiment, the shape of the notch 28a formed in the cover 26 (second plate portion 28) is different from that shown in FIGS.
In the present embodiment, protrusions 38a and 38b are formed on a part of the notch portion 28a on the end plate portions 35b and 36b side formed in the longitudinal direction of the second plate portion 28, and formed on the first plate portion 27 side. A protrusion 38c is formed on a part of the notch 28a on the end plate portion 37b side.

  On the other hand, the unit engaging portion 20b of the control unit mounting portion 20 that protrudes in a substantially rectangular parallelepiped shape from the outer peripheral upper surface of the torque sensor housing portion 16 faces the vehicle width direction as in the structure shown in FIGS. A pair of first engagement grooves 33a is formed on one side surface along the axial direction of the steering shaft 2, and a side surface facing the rear of the vehicle extends in the vehicle width direction and continues to the pair of first engagement grooves 33a. A second engaging groove 33b is formed.

  In the present embodiment, the end plate portions 35b and 36b forming the notch 28a of the cover 26 are fitted into the pair of first engagement grooves 33a facing the vehicle width direction of the unit engagement portion 20b, and the cover When the end plate portion 37b that forms the notch 28a and faces the front of the vehicle is fitted into the second engagement groove 33b that faces the rear of the unit engagement portion 20b, the projection on the end plate portions 35b and 36b side is formed. The cover 26 is attached to the control unit mounting portion 20 in a state in which the portions 38a and 38b press the inner walls of the pair of first engaging grooves 33a and the projections 38c on the end plate portion 37b side press the inner walls of the second engaging grooves 33b. Fixed to.

  Therefore, this embodiment prevents rattling when the notch portion 28a of the cover 26 is engaged with the pair of first engagement grooves 33a and second engagement grooves 33b of the unit engagement portion 20a. Even when motor vibration is transmitted from the electric motor 5 mounted on the reduction gear box 4 to the control unit 19, it is possible to prevent the cover 26 from generating unpleasant sounds such as chatter noise.

Further, FIG. 13 shows a second embodiment according to the present invention.
In the present embodiment, the shape of the unit engaging portion 20b of the control unit mounting portion 20 is different from that shown in FIGS.
In the present embodiment, protrusions are formed on part of the inner walls of the pair of first engagement grooves 33a extending along the axial direction of the steering shaft 2 formed on the two side surfaces of the unit engagement portion 20b facing the vehicle width direction. 39a is formed on the side facing the rear of the vehicle, and a protrusion 39b is formed on a part of the inner wall of the second engagement groove 33b extending in the vehicle width direction and continuing to the pair of first engagement grooves 33a. Has been.

On the other hand, the shape of the notch portion 28a formed in the cover 26 (second plate portion 28) is the same as that shown in FIGS.
In the present embodiment, the end plate portions 35b and 36b forming the notch 28a of the cover 26 are fitted into the pair of first engagement grooves 33a facing the vehicle width direction of the unit engagement portion 20b, and the cover When the end plate part 37b that forms the notch 28a and faces the front of the vehicle is fitted into the second engagement groove 33b that faces the rear of the unit engagement part 20b, the pair of first engagement grooves 33a The projection 26a formed on the inner wall presses the end plate portions 35b and 36b and the projection 26b formed on the inner wall of the second engagement groove 33b presses the end plate 35c. Fixed to.

Therefore, this embodiment also prevents rattling when the notch portion 28a of the cover 26 is engaged with the pair of first engagement grooves 33a and second engagement grooves 33b of the unit engagement portion 20a. Even when motor vibration is transmitted from the electric motor 5 mounted on the reduction gear box 4 to the control unit 19, it is possible to prevent the cover 26 from generating unpleasant sounds such as chatter noise.
In the above-described embodiment, the case where the electric motor 5, the control unit 19, and the female connector 45 are arranged in a straight line along a line orthogonal to the central axis of the steering column 3 has been described. It may be arranged in a straight line along a line intersecting the central axis of the steering column 3.

  Moreover, in the said embodiment, although the case where a brush motor was applied as the electric motor 5 was demonstrated, it is not limited to this, You may make it apply a brushless motor, In this case, a connection terminal 5c and 5d are connected to the power supply side of the excitation coil of each phase, and, for example, an inverter circuit having a field effect transistor (FET) for driving a brushless motor on the power board 23 and a gate of the field effect transistor of the inverter circuit are pulse width modulated. A gate driving circuit driven by a signal may be mounted.

  Furthermore, in the above-described embodiment, the case where the present invention is applied to a right-hand drive vehicle has been described. However, the present invention is not limited to this, and when applied to a left-hand drive vehicle, the reduction gear box 4 and the electric motor 5 The control unit 19 is arranged symmetrically with respect to the vertical plane passing through the central axis of the steering column 3, that is, the electric motor 5 is arranged on the right side of the control unit 19, and the female connector 45 and the terminal block 24c of the control unit 19 are connected. What is necessary is just to arrange | position on the left side, Furthermore, you may make it arrange | position the electric motor 5 on the vehicle outer side, and arrange | position the female connector 45 and the terminal block 24c on the vehicle inner side.

DESCRIPTION OF SYMBOLS 1 ... Electric power steering device, 2 ... Steering shaft, 2a ... Input shaft, 2b ... Torsion bar, 2c ... Output shaft, 3 ... Steering column, 3a ... Inner tube, 3b ... Outer tube, 4 ... Reduction gear box, 4b ... Support portion, 5 ... electric motor, 5b ... flange, 6 ... upper mounting bracket, 6a ... flange, 6a1 ... slit, 6b ... detachment capsule, 6b1 ... bolt through hole, 6c ... support plate portion, 6d ... tilt mechanism, 6g ... Tilt lever, 7 ... Lower mounting bracket, 7a ... Mounting plate part, 7b ... Supporting plate part, 7c ... Axis, 11 ... Worm, 12 ... Worm storage part, 13 ... Worm wheel, 14 ... Worm wheel storage part, 15 ... Torque sensors, 15a, 15b ... detection coils, 15c-15f ... external connection terminals, 16 ... torque sensor storage, 17 ... motor removal 18, column mounting portion, 19 control unit, 20 control unit mounting portion, 20 a flat mounting surface, 20 b unit engaging portion, 20 c frame mounting surface, 20 d opening portion, 21 heat radiating plate, 22 ... Power board, 22a, 22b ... Integrated circuit, 22c ... Connection terminal, 23 ... Frame, 23a ... Frame body, 23b ... Mounting plate part, 23c ... Terminal block, 24 ... Control board, 24a-24d ... Through hole, 24e ... Discrete parts, 26 ... Cover, 27 ... First plate, 28 ... Second plate (cover plate), 28a ... Notch, 29 ... Third plate, 28a ... Notch, 30 ... Fourth Plate part 31 ... Fifth plate part 32 ... Fixed piece 33a ... First engagement groove 33a ... Second engagement groove 34 ... Step part 35a, 36a, 37a ... Inclined plate part 35b, 36b, 37b ... end Parts, 38a, 38b, 38c, 39a, 39b ... protrusion, 45a ... power connector, 45b ... signal connector

Claims (5)

An electric motor for transmitting a steering assist force to a steering shaft to which a steering torque is transmitted via a speed reduction mechanism in a speed reduction gear box, and a control unit including a control board on which a control circuit for driving and controlling the electric motor is mounted The control unit is mounted with the cover plate portion of the cover for accommodating the control board of the control unit being brought close to the unit engaging portion formed protruding from the outer periphery of the reduction gear box, and the reduction gear box A plurality of external connection terminals connected to the built-in torque sensor are projected from an opening formed in the upper part of the unit engaging portion, and each of the plurality of external connection terminals is formed in the cover plate portion. In the electric power steering apparatus, which is passed through and electrically connected directly to a plurality of board side terminals provided on the control board
A first engagement groove along the axial direction of the steering shaft is formed on a side surface facing the vehicle width direction of the unit engagement portion, and extends in the vehicle width direction on a side surface facing the vehicle front-rear direction of the unit engagement portion. Forming an existing second engaging groove;
The end plate portion is slid in the vehicle front-rear direction while the end plate portion forming the notch portion of the cover plate portion is fitted in the first engagement groove, so that the end plate portion is engaged with the first engagement groove. An electric power steering apparatus, wherein the cover plate portion surrounds the opening in a state of being fitted into the groove and the second engagement groove.   One of the first engagement groove, the second engagement groove and the end plate portion is provided with pressing means for pressing one against the other when they are fitted and engaged with each other. The electric power steering apparatus according to claim 1.   The said pressing means is a projection part which protrudes from a part of said end-plate part, and contact | abuts, pressing the inner wall of a said 1st engagement groove | channel and a said 2nd engagement groove | channel. Electric power steering device.   The said pressing means is a projection part which protrudes from a part of inner wall of the said 1st engagement groove | channel and the said 2nd engagement groove | channel, and contacts, pressing the end surface of the said end plate part. The electric power steering apparatus as described.   The second engagement groove is formed on a side surface of the unit engagement portion facing the rear of the vehicle, and the cover is moved from the rear of the vehicle so as to engage the cover plate portion with the unit engagement portion. The electric power steering apparatus according to any one of claims 1 to 4, wherein the electric power steering apparatus is characterized.

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