JP2011168169A - Electric power steering device - Google Patents

Abstract

An electric power steering device that is easy to assemble and can reliably prevent intrusion of conductive foreign matter between electrodes of a motor-side external connection portion and a unit-side external connection portion while simplifying the structure. I will provide a.
A protective cover 27 is provided on one outer periphery of a motor-side external connection portion 5d and a unit-side external connection portion 28, and covers a motor-side external connection portion and a unit-side external connection portion that are connected to each other. The protective cover 27 includes a cover main body 27a and a belt-shaped skirt portion 27c that extends from the hem portion 27b of the cover main body and contacts the outer surface 5e around the motor-side external connection portion that faces the hem portion. ing.
[Selection] Figure 10

Description

  The present invention relates to an electric power steering apparatus including an electric motor that applies a steering assist force to a steering system, and a control unit that controls an energization state of the electric motor in accordance with a steering torque of the steering system.

  As a conventional electric power steering apparatus, there is an apparatus that applies a steering assist torque to a steering system of a vehicle by decelerating the rotation of an electric motor with a gear box. In such an electric power steering device, an electric motor for transmitting steering assist force and a control unit for driving and controlling the electric motor are arranged in parallel in the reduction gear box, and a motor-side external connection portion provided outside the electric motor; An electromechanically integrated device is known in which a unit-side external connection provided outside the control unit is directly connected (see, for example, Patent Document 1).

  In the device of Patent Document 1, the motor-side external connection portion and the unit-side external connection portion are connected in a state of projecting to the outside of the reduction gear box, and the motor-side external connection portion and the unit-side external connection portion are covered. Since the cover (referred to as a terminal cover in Patent Document 1) is mounted from the outside of the reduction gear box, the protective cover can be easily mounted and the structure can be simplified. An increase in the cost of manufacturing the device can be suppressed.

JP 2009-23456 A

However, in the device of Patent Document 1, a gap is easily generated between the skirt of the protective cover and the outer surface around the motor-side external connection portion and the unit-side external connection portion. If the infiltrated conductive foreign matter adheres between the electrodes of the motor-side external connection portion and the unit-side external connection portion, an electrical short circuit may occur.
Therefore, the present invention has been made paying attention to the unsolved problems of the above-described conventional example, and is easy to assemble and the electrodes of the motor side external connection portion and the unit side external connection portion while simplifying the structure. An object of the present invention is to provide an electric power steering device that can reliably prevent a conductive foreign substance from entering between.

  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 a steering torque is transmitted, and a steering assist to the steering shaft via a reduction mechanism in a reduction gear box. And a control unit including a control board on which the control circuit for driving and controlling the electric motor is mounted in parallel to the reduction gear box, and the outside of the electric motor. A motor-side external connection portion is provided so as to protrude from a position close to the control unit, and a unit-side external connection portion that is in surface contact with the motor-side external connection portion is located near the electric motor that is outside the control unit. In the projecting electric power steering device, the motor side external connection part and the unit side outside A cover body that covers the motor-side external connection portion and the unit-side external connection portion that are assembled to one outer periphery of the connection portion and connected to each other, and extends from the hem portion of the cover body, A protective cover is provided that includes a belt-shaped skirt portion that contacts at least one outer surface of the motor-side external connection portion and the periphery of the unit-side external connection portion.

According to a second aspect of the present invention, in the electric power steering device according to the first aspect, the skirt portion is formed on a side of the motor-side external connection portion and the unit-side external connection portion that is exposed to the outside. ing.
According to a third aspect of the present invention, in the electric power steering apparatus according to the first or second aspect, the skirt portion is formed in a flare shape that spreads away from the cover body.

According to a fourth aspect of the present invention, in the electric power steering device according to any one of the first to third aspects, the thickness of the skirt portion gradually decreases as the skirt portion moves away from the cover body. ing.
According to a fifth aspect of the present invention, in the electric power steering apparatus according to any one of the first to fourth aspects, the skirt portion is assembled in a state where the cover main body is inclined, and the skirt portion is separated from the skirt portion. The height of the side facing the outer surface is set longer than the length of the side not facing the outer surface so that the outer surface is contacted even if the distance to the outer surface is separated.

  On the other hand, an electric power steering apparatus according to claim 6 is a steering column having a steering shaft to which a steering torque is transmitted, and an electric motor for transmitting a steering assist force to the steering shaft via a reduction mechanism in a reduction gear box. A control unit including a control board on which the electric motor and a control circuit for driving and controlling the electric motor are mounted in the reduction gear box, and in close proximity to the control unit that is outside the electric motor Electric power with a motor-side external connection projectingly provided at a position where the motor-side external connection is provided and a unit-side external connection projecting in contact with the motor-side external connection at a position close to the electric motor that is outside the control unit In the steering device, assembled to one of the motor side external connection part and the unit side external connection part A cover main body that covers the motor-side external connection portion and the unit-side external connection portion that are connected to each other, and that protrudes from the inner wall of the cover main body and extends outward from the hem portion of the cover main body, and is connected to each other And a partition plate for partitioning a plurality of electrodes of the motor-side external connection portion and the unit-side external connection portion.

  Furthermore, the invention according to claim 7 is the electric power steering device according to any one of claims 1 to 5, wherein the protective cover protrudes from the inner wall of the cover body and is located outside the skirt of the cover body. A partition plate is provided that extends and is connected to each other and separates a plurality of electrodes of the motor-side external connection portion and the unit-side external connection portion.

According to the electric power steering device according to the present invention, the skirt portion of the protective cover is in contact with the outer surface of at least one of the periphery of the motor-side external connection portion and the periphery of the unit-side external connection portion. Since there is almost no gap between them, it is possible to reliably prevent the conductive foreign matter from entering the inside of the cover body.
And since the motor side external connection part outside the electric motor and the motor side external connection part outside the control unit are connected and the protective cover covers them, the protective cover can be easily attached, Simplification can also be achieved, and the manufacturing cost of the electric power steering apparatus can be reduced.

It is the perspective view shown from the left 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 an electric power steering apparatus. It is a perspective view which shows the external appearance of the reduction gear box which comprises an electric power steering device. It is a perspective view which shows the connection relation of the electric motor which comprises an electric power steering apparatus, and a control unit. It is a front view which shows the internal structure of the electric motor which comprises an electric power steering apparatus. It is a disassembled perspective view of a control unit. It is a perspective view which shows the terminal block integrated with the control unit, and the protective cover engaged with this terminal block. It is the perspective view which showed the protective cover of 1st Embodiment. It is an AA arrow line view of FIG. It is a figure which shows the state which attached the protective cover of 1st Embodiment to the terminal block and connection terminal which were electrically connected. It is a figure which shows the state which attached the protective cover of 2nd Embodiment to the terminal block and connection terminal which were electrically connected. It is a perspective view which shows the protective cover of 3rd Embodiment. It is a figure which shows the state which attached the protective cover of 3rd Embodiment to the terminal block and connection terminal which were electrically connected. It is a figure which shows the position of the partition plate which comprises the protective cover of 3rd Embodiment. It is the perspective view which showed the protective cover of 4th Embodiment.

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.
In FIG. 1, reference numeral 1 denotes a column-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). An electric motor 5 whose axial direction is extended in a direction perpendicular to the axial direction of the steering column 3 is disposed in the reduction gear box 4.

  The steering column 3 has a double tube structure of an inner tube 3a and an outer tube 3b. 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 includes a mounting plate portion 7a that is mounted on a vehicle body side member (not shown), and a pair of support plate portions 7b that extend in parallel from the lower surface of the mounting plate portion 7a at a predetermined distance in the left-right direction. Is formed. And the lower end of the support plate part 7b is rotatably connected to the support part 4b integrally formed in the vehicle front side of the reduction gear box 4 via the pivot 7c (refer FIG. 2).

The upper mounting bracket 6 includes a mounting plate portion 6a attached to a vehicle body side member (not shown) and a pair of support plate portions fixed to the lower end of the mounting plate portion 6a and spaced apart in the left-right (vehicle width) direction. 6b and a tilt mechanism 6c for supporting the outer tube 3b of the steering column 3 formed on the pair of support plate portions 6b. Then, the tilt lever 6g of the tilt mechanism 6c is rotated to release the support state of the outer tube 3b, whereby 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 includes an input shaft 2a whose upper end is connected to a steering wheel (not shown), and a torsion bar 2b connected to the lower end of the input shaft 2a via a torsion bar 2b. It is comprised with the output shaft 2c to cover.

  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 FIGS. 2 and 3, 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 lower side of the worm storage portion 12. A worm wheel housing part 14 for housing a worm wheel 13 having a central axis perpendicular to the central axis thereof and meshing with the worm 11, and a torque integrally and coaxially connected to the vehicle rear side of the worm wheel storage part 14 Torque sensor housing portion 16 for housing the sensor 15, motor mounting portion 17 for attaching the electric motor 5 formed on the open end surface of the worm housing portion 12, and a cylindrical shape formed at the vehicle rear end of the torque sensor housing portion 16 The column attachment portion 18, the worm storage portion 12 and the worm wheel storage portion 14 are straddled across a part of the worm wheel storage portion 14 and the torque sensor storage. 16 a control unit 19 which is formed in a plane perpendicular to the central axis of and a control unit mounting section 20 for mounting. The vehicle front end portion 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 torsional state between the input shaft 2a and the output shaft 2c of the steering shaft 2 and transmits the steering torque transmitted to the steering shaft to a pair of detection coils. The external connection terminals 15c and 15d are configured to be detected by 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. 15e and 15f are connected, and the protruding portions of the external connection terminals 15c to 15f are bent at the central portion in parallel with the central axis of the steering column 3 to form an L shape.

As shown in FIG. 4, the electric motor 5 has connection terminals 5c and 5d formed at positions close to and opposed to the control unit 19 mounted on the control unit mounting portion 20 at a position close to the mounting flange 5b. As shown in FIG. 5, each of the connection terminals 5c and 5d is insulated from each other in a synthetic resin brush support 5f having an armature insertion hole in the center of the bottom, and is connected to two sets of brushes 5g and 5h. The arc-shaped connection terminals 5i and 5j connected individually are integrally formed at one end facing each other.
As shown in FIG. 3, the control unit mounting portion 20 formed in the reduction gear box 4 has a flat mounting surface 20a formed between the worm storage portion 12 and the upper side of the worm wheel storage portion 14 below. And a flat mounting surface 20a formed on the upper surface of the torque sensor storage portion 16 and a unit mounting surface 20b perpendicular to the upper surface of the torque sensor storage portion 16 are formed in an L shape when viewed from the left-right direction.

Further, a frame mounting surface 20c having a narrow width is formed on the rear end surface of the motor mounting portion 17 in parallel with the flat mounting surface 20a and at a position on the vehicle rear side of the flat mounting surface 20a. And the external connection terminals 15c-15f of the torque sensor 15 protrude from the center part of the left-right direction of the unit mounting surface 20b.
As shown in FIG. 6, the control unit 19 mounted on the control unit mounting portion 20 includes a metal heat radiation plate 21 having a high heat transfer rate, a power substrate 23, a rectangular frame-shaped synthetic resin frame 24, and the like. The control board 25 and the cover 26 are provided.

  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 board 23 is a discrete component 23a, 23b 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. A synthetic resin frame 24 surrounds the power board 23. The control board 25 is attached to the front surface of the synthetic resin frame 24 and has through holes 25a to 25d that are directly inserted through the external connection terminals 15c to 15f of the torque sensor 15. A steering assist current command value is calculated based on the vehicle speed detection value from the vehicle speed sensor that is not operated, and 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 obtain a power board By calculating a voltage command value to the pulse width modulation circuit 23, a discrete unit 25e such as a micro control unit (MCU) for controlling a steering assist force generated by the electric motor 5 and its peripheral devices is mounted. The cover 26 covers the power board 23, the synthetic resin frame 24, and the control board 25.

  The synthetic resin frame 24 includes a rectangular frame-shaped frame body 24a, a mounting plate portion 24b formed on the left end of the frame body 24a and fixed to the frame mounting surface 20c of the reduction gear box 4, and the mounting plate. A terminal block 24c fixed on the portion 24b and electrically connected to the connection terminals 5c and 5d of the electric motor 5 and a female connector 45 fixed to the right end of the frame body 24a are provided. The female connector 45 is connected to a power supply connector 45a connected to a battery (not shown) via a power supply male connector 46, and a network such as CAN that exchanges data with control devices in each part of the vehicle body. And a signal connector 45b. The power board 23 and the control board 25 are connected via the connection terminal 22a.

  In the control unit 19 configured as described above, the power board 23 is screwed to the inner surface of the heat radiating plate 21. Then, heat radiation grease is applied to the flat mounting surface 20a of the control unit mounting portion 20 of the reduction gear box 4, and the heat radiating plate 21 is placed on the flat mounting surface 20a and screwed. The synthetic resin frame 24 is placed on the flat mounting surface 20 a and the frame mounting surface 20 c so as to surround the power substrate 23. Then, the mounting plate portion 24 b of the synthetic resin frame 24 is screwed to the frame mounting surface 20 c of the reduction gear box 4. Further, on the front side of the synthetic resin frame 24, the control board 25 is screwed after inserting the external connection terminals 15c to 15f of the torque sensor 15 through the through holes 25a to 25d, and the external connection terminals 15c to 15f. The control unit 19 is mounted on the control unit mounting portion 20 of the reduction gear box 4 by soldering the through holes 25 a to 25 d and mounting the cover 26 on the flat mounting surface 20 a of the control unit mounting portion 20.

Then, the assembly of the steering column 3, the steering shaft 2, the worm 11 and the worm wheel 13 is completed, and the mounting flange 5b of the electric motor 5 is assembled to the motor mounting portion 17 as shown in FIG. The connection terminals 5c and 5d of the electric motor 5 are electrically connected to the terminal block 24c fixed to the mounting plate portion 24b of the frame 24.
Here, as shown in FIG. 1, the terminal block 24c and the connection terminals 5c, 5d that are electrically connected are covered with a protective cover 27 made of synthetic resin.

  As shown in FIG. 7, the terminal block 24c integrated with the control unit 19 includes a substantially rectangular parallelepiped terminal block 28 rising from the mounting plate portion 24b. A pair of plate-like electrodes 30 and 31 provided with screw holes 29 are embedded in a rectangular side surface facing in a state of being separated in the longitudinal direction. In addition, a pair of engaging protrusions 33 with which the protective cover 27 engages are formed on both side surfaces of the terminal block 28 in the longitudinal direction.

  As shown in FIG. 4, the connection terminals 5c and 5d of the electric motor 5 are in contact with the pair of electrodes 30 and 31 of the terminal block 24c so that the screw passage holes formed in the connection terminals 5c and 5d correspond to the screw holes 29, respectively. By screwing the fixing screw 5o into the screw hole 29 from the terminal 5c, 5d side, one electrode 30 is electrically connected to one connection terminal 5c, and the other electrode 31 is electrically connected to the other connection terminal 5d. It is connected to the.

As shown in FIGS. 7 and 8, the protective cover 27 is a member that covers a side surface and an upper surface of the terminal block 28 while providing a predetermined space between the electrodes 30 and 31 embedded in the terminal block 28.
As shown in FIG. 8, the protective cover 27 has a substantially rectangular parallelepiped box-shaped cover main body 27a, a hem portion 27b formed by extending a part of the opening edge of the cover main body 27a in a U shape, And a belt-like skirt portion 27c formed so as to protrude from the entire lower portion of the hem portion 27b.

On the side plate of the cover body 27a, an engagement groove 34 is formed that engages with the pair of engagement protrusions 33 described above when the terminal block 28 is covered.
The skirt portion 27c is formed in a flared shape extending from the hem portion 27b on the side away from the cover main body 27a, and as shown in FIG. 9, the thickness gradually decreases as the distance from the hem portion 27b increases. Yes.

Then, as shown in FIG. 10, the engaging groove 34 of the protective cover 27 is engaged with the engaging protrusion 33 of the terminal block 28 to which the connection terminals 5c and 5d of the electric motor 5 are connected, so that the protective cover 27 is connected to the terminal block. When attached to 28, the outer periphery of the terminal block 28 is covered with the protective cover 27.
At the same time, as shown in FIG. 10, the skirt portion 27c of the protective cover 27 contacts the outer surface 5e of the electric motor 5 around the connection terminals 5c, 5d while being deformed so as to spread outward.

Next, the operation of the above embodiment will be described.
When an ignition switch (not shown) of the vehicle is turned on and electric power is supplied from the battery to the power board 23 and the control board 25, 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 connected. 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 23 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, in the present embodiment, the terminal block 24c on the control unit 19 side and the connection terminals 5c and 5d of the electric motor 5 are electrically connected in a state opened to the atmosphere outside the reduction gear box 4, Even when a conductive foreign matter such as iron scrap is generated in the worm 11 or the like in the reduction gear box 4 when the electric power steering apparatus 1 is assembled, an electrical short is generated in the connection terminals 5c and 5d of the electric motor 5. There is no fear.

  Further, the terminal block 24c on the control unit 19 side and the connection terminals 5c and 5d of the electric motor 5 are electrically connected outside the reduction gear box 4, and the engaging groove 34 provided in the protective cover 27 is connected to the terminal block 24c. Since the protective cover 27 is simply detachably attached to the terminal block 28 by engaging with the engaging protrusions 33 of the terminal block 28, the protective cover 27 can be easily attached and the structure can be simplified. Thus, an increase in manufacturing cost of the electric power steering apparatus 1 can be suppressed.

  Further, the periphery of the pair of connection terminals 5c and 5d and the terminal block 24c is covered with a protective cover 27, and the belt-like skirt portion 27c formed on the protective cover 27 is connected to the connection terminals 5c and 5d of the electric motor 5. Since it is provided on the side exposed to the outside in contact with the outer surface 5e of the electric motor 5, it is difficult for the conductive foreign matter to enter the inside of the protective cover 27, and an electrical short between the connection terminals 5c and 5d. Can be reliably prevented.

Further, the skirt portion 27c of the protective cover 27 is formed in a flared shape extending from the skirt portion 27b on the side away from the cover main body 27a, and its tip portion is in contact with the outer surface 5e of the electric motor 5, so that the skirt portion 27c. There is almost no gap between the outer surface 5e and the outer surface 5e, and it is possible to reliably prevent the conductive foreign matter from entering the cover body 27a.
Further, when the control unit 19 is mounted on the control unit mounting portion 20 of the reduction gear box 4, even if a slight error occurs in the assembly position of the terminal block 24c, the periphery of the connection terminals 5c and 5d and the terminal block 24c is covered. Since the protective cover 27 comes into contact with the outer surface 5e of the electric motor 5 while elastically deforming the skirt portion 27c whose thickness is gradually reduced as the protective cover 27 moves away from the skirt portion 27b, it absorbs the dimension crossing at the time of assembling the terminal block 24c. The gap between the skirt portion 27c and the outer surface 5e of the electric motor 5 can be eliminated.

Incidentally, the protective cover 27 may be attached to the terminal block 28 in an inclined state. In particular, the cover body 27a is often attached to the terminal block 28 with the side covering the terminal block 28 lower than the side covering the connection terminals 5c and 5d of the electric motor 5 and the bottom 27b being lifted. In this case, there is a possibility that a gap is generated between the skirt portion 27 c and the outer surface 5 e of the electric motor 5.
Therefore, FIG. 11 shows the protective cover 27 according to the second embodiment in which no gap is generated between the terminal block 28 and the outer surface 5e of the electric motor 5 even when the terminal block 28 is mounted in an inclined state.

In the protective cover 27 according to the second embodiment, the length of the longitudinal skirt portion 27c1 extending from the longitudinal portion of the U-shaped hem portion 27b of the skirt portion 27c is tilted. Even if it is mounted, the length is set so that it can come into contact with the outer surface 5e of the electric motor 5, and it is continuous from the long direction skirt portion 27c1 and extends in the short direction of the U-shaped skirt portion 27b. The length of the short direction skirt portion 27c2 extended from the portion (the portion close to the engaging groove 34) is gradually set shorter as the distance from the long direction skirt portion 27c1 increases.
As described above, even if the protective cover 27 having the long skirt portion 27c1 and the short skirt portion 27c2 is attached to the terminal block 28 in a tilted state, there is a gap between the protective cover 27 and the outer surface 5e of the electric motor 5. It does not occur, and it is possible to reliably prevent the conductive foreign matter from entering the cover main body 27a.

12 to 14 show a protective cover 50 according to a third embodiment of the present invention. In addition, the same code | symbol is attached | subjected to the component same as the structure shown in FIG. 8, and the description is abbreviate | omitted.
Unlike the protective cover 27 of the first embodiment shown in FIG. 8, the protective cover 50 of this embodiment does not form the skirt portion 27 c shown in the first embodiment, and the cover body 27 a A partition plate 50a is formed so as to partition the internal space.
As shown in FIG. 12, the free end of the partition plate 50a includes a facing portion 50a1 that faces the outer surface 5e of the electric motor 5, and an extension portion 50a2 that continues to the facing portion 50a1 and extends downward from the skirt portion 27b. It is made the shape with.

  When the protective cover 50 is attached so as to cover the terminal block 28 and the connection terminals 5c and 5d of the electric motor 5, the partition plate 50a is connected to the connection terminals 5c and 5d of the electric motor 5 as shown in FIG. Each of the connection terminals 5c and 5d is located in between and divided into different spaces, and the extension part 50a2 of the partition plate 50a extends to a position close to the frame mounting surface 20c of the reduction gear box 4 as shown in FIG. To do.

  When the protective cover 50 having the above configuration is mounted so as to cover the terminal block 28 and the connection terminals 5c and 5d of the electric motor 5, there is a space between the skirt portion 27b of the protective cover 50 and the outer surface 5e of the electric motor 5. However, the partition plate 50a of the protective cover 50 extends to a position close to the frame mounting surface 20c of the reduction gear box 4 while partitioning each of the connection terminals 5c and 5d into different spaces. Even if it penetrates, electrical short-circuit between the connection terminals 5c and 5d can be reliably prevented.

Further, FIG. 15 shows a protective cover 51 according to a fourth embodiment of the present invention.
The protective cover 51 of the present embodiment is formed with a band-like skirt portion 27c protruding from the entire lower portion of the skirt portion 27b, and a partition plate 50a so as to partition the internal space of the cover body 27a from the inner wall of the cover body 27a. Is formed.
Similarly to the configuration shown in FIG. 8, the skirt portion 27c is formed in a flared shape extending from the hem portion 27b on the side away from the cover body 27a, and the thickness gradually decreases as the distance from the hem portion 27b increases. ing.

Similarly to the configuration shown in FIG. 12, the partition plate 50a includes an extension 50a2 that extends downward from the skirt 27b.
When the protective cover 51 having the above-described configuration is attached so as to cover the terminal block 28 and the connection terminals 5c and 5d of the electric motor 5, the strip-like skirt portion 27c comes into contact with the outer surface 5e of the electric motor 5 so that the conductive foreign matter is removed. Since it becomes difficult to enter the inside of the protective cover 51, the partition plate 50a extends to a position close to the frame mounting surface 20c of the reduction gear box 4 while partitioning the connection terminals 5c and 5d into different spaces. The electrical short between the connection terminals 5c and 5d can be more reliably prevented.
In the above embodiment, the connection terminals 5c and 5d are provided in the electric motor 5 and the terminal block 24c is provided in the control unit 19. However, the present invention is not limited to this, and the terminal block is provided in the electric motor 5. And a connection terminal may be provided on the control unit 19.

In the above 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. However, the present invention is not limited to this. Instead of this, they 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 are used. 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 part, 5 ... Electric motor, 5b ... Flange, 5c, 5d ... Connection terminal (motor side external connection part), 5e ... Outer surface (outer surface around the motor side external connection part), 5f ... Brush support, 5g, 5h ... Brush, 5i, 5j ... Connection terminal, 5o ... Fixing screw, 6 ... Upper mounting bracket, 6a ... Mounting plate, 6b ... Supporting plate, 6c ... Tilt mechanism, 6g ... Tilt lever, 7 ... Lower mounting bracket, 7a ... mounting plate part, 7b ... support plate part, 7c ... pivot, 11 ... worm, 12 ... worm storage part, 13 ... worm wheel, 14 ... worm wheel storage part, 15 ... torr Sensor, 15a ... Detection coil, 15a, 15b ... Detection coil, 15c-15f ... External connection terminal, 16 ... Torque sensor storage part, 17 ... Motor mounting part, 18 ... Column mounting part, 19 ... Control unit, 20 ... Control unit Mounting portion, 20a: flat mounting surface, 20b: unit mounting surface, 20c ... frame mounting surface, 21 ... heat dissipation plate, 22a ... connection terminal, 23 ... power board, 23a, 23b ... discrete components, 24 ... synthetic resin frame 24a ... Frame body, 24b ... Mounting plate, 24c ... Terminal block, 25 ... Control board, 25a-25d ... Through hole, 25e ... Discrete parts, 26 ... Cover, 27 ... Protective cover, 27a ... Cover body, 27b ... Bottom part (the bottom part of the cover body), 27c... Skirt part, 27c1. 2 ... Short direction skirt part, 28 ... Terminal block (newt side external connection part), 29 ... Screw hole, 30, 31 ... Electrode, 33 ... engagement protrusion, 34 ... engagement groove, 45 ... female connector, 45a ... Power connector, 45b ... Signal connector, 46 ... Power male connector, 50 ... Protective cover, 50a ... Partition plate, 50a1 ... Partition plate facing part, 50a2 ... Partition plate extension, 51 ... Protective cover

Claims (7)

A steering column having a steering shaft to which a steering torque is transmitted; and an electric motor for transmitting a steering assist force to the steering shaft via a speed reduction mechanism in a speed reduction gear box, the speed reduction gear box having the electric motor And a control unit including a control board on which a control circuit for driving and controlling the electric motor is provided, and a motor-side external connection portion is provided so as to protrude from a position close to the control unit that is outside the electric motor. In the electric power steering apparatus provided with a unit-side external connection portion that projects in surface contact with the motor-side external connection portion at a position close to the electric motor that is outside the control unit,
A cover body that covers the motor-side external connection portion and the unit-side external connection portion that are assembled to one outer periphery of the motor-side external connection portion and the unit-side external connection portion and connected to each other;
A belt-like skirt that is formed extending from the skirt of the cover body and contacts at least one of the outer surfaces of the motor-side external connection and the unit-side external connection facing the skirt, An electric power steering apparatus comprising a protective cover made of   The electric power steering apparatus according to claim 1, wherein the skirt portion is formed on a side of the motor side external connection portion and the unit side external connection portion that are exposed to the outside.   The electric power steering apparatus according to claim 1 or 2, wherein the skirt portion is formed in a flare shape that spreads away from the cover body.   4. The electric power steering apparatus according to claim 1, wherein the skirt portion has a thickness that gradually decreases as the skirt portion moves away from the cover body. 5.   The skirt portion is assembled in a state where the cover main body is tilted, and the height of the side facing the outer surface is adjusted so that the skirt portion contacts the outer surface even if the distance from the skirt portion to the outer surface is separated. 5. The electric power steering apparatus according to claim 1, wherein the electric power steering apparatus is set to be longer than a length on a side not facing the outer surface. A steering column having a steering shaft to which a steering torque is transmitted; and an electric motor for transmitting a steering assist force to the steering shaft via a speed reduction mechanism in a speed reduction gear box, the speed reduction gear box having the electric motor And a control unit including a control board on which a control circuit for driving and controlling the electric motor is provided, and a motor-side external connection portion is provided so as to protrude from a position close to the control unit that is outside the electric motor. In the electric power steering apparatus provided with a unit-side external connection portion that projects in surface contact with the motor-side external connection portion at a position close to the electric motor that is outside the control unit,
A cover body that covers the motor-side external connection portion and the unit-side external connection portion that are assembled to one of the motor-side external connection portion and the unit-side external connection portion and connected to each other;
A partition plate that protrudes from the inner wall of the cover body and extends from the bottom of the cover body to the outside and divides a plurality of electrodes of the motor-side external connection portion and the unit-side external connection portion that are connected to each other And an electric power steering device comprising a protective cover. The electric power steering apparatus according to any one of claims 1 to 5,
The protective cover protrudes from the inner wall of the cover main body and extends outward from the bottom of the cover main body, and includes a plurality of electrodes of the motor-side external connection portion and the unit-side external connection portion that are connected to each other. An electric power steering device characterized in that a partition plate is provided for separating the spaces.

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