JP2008179249A - Electric power steering device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electric power steering device capable of lowering the height of a motor side joint portion and a unit side joint portion without degrading assemblability. <P>SOLUTION: The column-assist type electric power steering device is provided with a steering column 3 with a steering shaft 2 transmitting steering torque mounted therein, and an electric motor 5 transmitting steering assist force to the steering shaft 2 through a speed reduction mechanism in a speed reduction gearbox 4. The electric motor 5 and a control unit 19 including a control board mounted with a control circuit driving and controlling the motor are juxtaposedly provided in the gearbox 4. Motor side joint parts 5c, 5d provided at the electric motor 5, and unit side joint parts 33a, 33b face-contactable with the motor side joint parts 5c, 5d provided at the control unit side are tiltedly disposed against the axial direction of the electric motor, respectively. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention provides a column assist type electric motor comprising 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 present invention relates to a power steering device.

As a conventional electric power steering device, for example, a housing in which a metal substrate is fixed in close contact is disposed on the opposite side of the electric motor, and heat radiating fins are provided on the outside of the housing and on the inside and outside of the cover attached to the electric motor, A power board, a large current board, and a control board are built in a laminated structure inside the housing and cover, and a 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. There has been known an electric power steering apparatus (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 are stacked in a housing and a cover to constitute a control device, and this control device is attached to an electric motor. Since 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, the electric connection between the electric motor and the control device is directly performed. However, since the electric motor itself is a heating element, the heat generated on the power board of the control device cannot be transferred to the electric motor side, so heat is released to the outside of the housing and the inside and outside of the cover, respectively. There is a problem that it is necessary to provide fins, and the control device becomes large.

  For this reason, it is considered that the control device is mounted in the vicinity of the electric motor in the reduction gear box having a large heat capacity and a large surface area. In this case, when the electric motor is assembled to the reduction gear box, the output shaft of the electric motor and the worm shaft of the reduction gear box are splined or serrated, so that the electric motor is circumferentially connected when they are combined. In order to prevent interference between the motor-side connecting portion and the unit-side connecting portion that can come into surface contact with the motor-side connecting portion provided on the control unit side during this rotation, the electric motor The motor-side connecting part protrudes in a direction perpendicular to the axial direction of the electric motor on the mounting surface of the reduction gear box, and the output shaft of the electric motor and the worm shaft are splined or serrated to connect the electric motor to the reduction gear. It is conceivable that the motor-side connecting portion and the unit-side connecting portion are brought into surface contact when assembled in the box.

  Thus, when extending the motor side connection portion and the unit side connection portion in a direction perpendicular to the axial direction of the electric motor, when screwing the motor side connection portion and the unit side connection portion, There is a certain limitation to reduce the height of the terminal block because it is necessary to be high enough to insert a tool such as a screwdriver. On the other hand, the terminal block may affect the collapse stroke of the shock absorbing structure, and considering the versatility of multiple vehicle types, it is required that the height of the terminal block be as low as possible.

  Therefore, the present invention has been made paying attention to the unsolved problems of the above-described conventional example, and can reduce the height of the motor-side connecting portion and the unit-side connecting portion without reducing the assemblability. It aims at providing a power steering device.

  In order to achieve the above object, an electric power steering apparatus according to a first aspect of the present invention includes a steering column having a steering shaft to which steering torque is transmitted, and a steering assist to the steering shaft via a reduction mechanism in a reduction gear box. A column assist type electric power steering apparatus including an electric motor for transmitting force, the control unit including a control board in which the electric motor and a control circuit for driving and controlling the electric motor are mounted on the reduction gear box Are arranged in parallel, and a motor side connecting portion provided in the electric motor and a unit side connecting portion capable of surface contact with the motor side connecting portion provided on the control unit side are inclined with respect to the axial direction of the electric motor, respectively. It is characterized by being arranged.

An electric power steering device according to claim 2 is the invention according to claim 1, wherein the motor side connection portion and the unit side connection portion are configured by one of a connection terminal and a terminal block. It is a feature.
Furthermore, the electric power steering apparatus according to a third aspect is the invention according to the first or second aspect, wherein the motor side connecting portion is integrally formed with a bus bar that distributes power to a brush or a coil inside the electric motor. It is characterized by that.

Furthermore, an electric power steering device according to a fourth aspect is the invention according to any one of the first to third aspects, wherein at least one of the motor side connection portion and the unit side connection portion is flexible. In a state where the electric motor and the control unit are assembled to the gear box, a predetermined gap is provided between them.
Still further, an electric power steering apparatus according to a fifth aspect is characterized in that, in the invention according to any one of the first to fourth aspects, the motor side connecting portion and the unit side connecting portion are screwed. .

  According to the present invention, the motor side connecting portion provided in the electric motor and the unit side connecting portion that can be brought into surface contact with the motor side connecting portion provided in the control unit are inclined with respect to the axial direction of the electric motor. In addition to securing the necessary area at the motor side connection part and the unit side connection part, it is possible to secure a sufficient insertion area for the mounting tool and reduce the assembly performance without deteriorating the assembling property. The effect that the protrusion length of the direction orthogonal to an axial direction can be shortened is acquired.

In addition, since the unit side connection part of the control unit is brought into surface contact with the electric motor motor side connection part, the electrical connection length between the two is minimized, the wiring resistance is minimized, and electric noise is surely applied. In addition to preventing this, it is possible to obtain an effect that there is no need to provide a connection terminal having a large rigidity.
Further, since it is not necessary to provide a motor harness between the electric motor and the control unit, noise radiated from the motor harness is reduced, and an effect that the influence on radio noise can be reduced can be obtained.

  Further, at least one of the motor side connection portion and the unit side connection portion has flexibility, and in a state where the electric motor and the control unit are assembled to the gear box, a predetermined gap is provided between them. Even if the electric motor is rotated during the alignment work for rotating the electric motor when the output shaft of the electric motor and the input shaft of the reduction gear box are connected, the motor side connection part and the unit side It is possible to reliably prevent the connecting portions from interfering with each other, and even when the electric motor is inserted obliquely with respect to the axial direction of the reduction gear housing when the electric motor is assembled, the connecting portion and the unit side connecting portion are mutually connected. Interference can be reliably prevented.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a perspective view showing an embodiment of the present invention, FIG. 2 is a perspective view of a state in which an electric motor and a control unit are mounted on a reduction gear box, and FIG. 3 is a longitudinal section showing an enlarged part of the reduction gear box. 4 is an exploded perspective view, FIG. 5 is a perspective view showing the electric motor, FIG. 6 is a front view showing the bus bar structure of the electric motor, FIG. 7 is a perspective view seen from the front side of the reduction gear box, FIG. FIG. 9 is a front view showing a control board, FIG. 10 is a front view showing a power board, FIG. 11 is a perspective view showing a mold part, and FIG. 12 is a rear view of the mold part. FIG. 13 is an exploded perspective view seen from the side, and FIG. 13 is a perspective view showing a state where the control unit is assembled to the reduction gear box.

  In FIG. 1, reference numeral 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 composed of a brush 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.
Here, the mounting plate portion 6a is composed of a pair of left and right capsules 6d attached to a vehicle body side member (not shown), and a sliding plate portion 6f fixed to these capsules 6d by resin injection 6e. When an impact force for moving the steering column 3 to the front of the vehicle body acts, the sliding plate portion 6f slides to the front of the vehicle body with respect to the capsule 6d, and the resin injection 6e is sheared. It is comprised so that it may become.

Further, by rotating the tilt lever 6g of the tilt mechanism 6c and releasing the support state, the tilt position of the steering column 3 can be adjusted up and down around the pivot 7c of the lower mounting bracket 7.
Further, as shown in FIG. 3, 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. 4, 7 and 8, the reduction gear box 4 is made of a material having high thermal conductivity such as aluminum, aluminum alloy, magnesium and magnesium alloy, for example, by die casting. It is formed by doing. The reduction gear box 4 has a worm housing part 12 for housing a worm 11 connected to the output shaft 5a of the electric motor 5, and a worm housing part 12 having a central axis perpendicular to the central axis below the worm housing part 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 2a 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 19 which is formed in a plane perpendicular to the center axis of the torque sensor accommodating portion 16. 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. 3, 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 15a. And 15b, and external connection terminals 15c, 15d projecting outside 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 projecting portions of these 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.

  In addition, the electric motor 5 distributes power to the built-in brush at a position close to and opposed to the control unit 19 mounted on the control unit mounting section 20 at a position close to the mounting flange section 5b mounted on one of the reduction gear boxes 4. Connecting terminals 5c and 5d as motor side connecting portions formed integrally with bus bars 5i and 5j, which will be described later, are directed forward from the end face of the mounting flange 5b at an inclination angle of, for example, 45 ° with respect to the axial direction of the electric motor 5. The slope is extended. The distal ends of the connection terminals 5c and 5d are formed in an arc shape, and a long hole 5e through which a fixing screw is inserted is formed on the distal end side. At this time, as shown in FIG. 5, when the steering column 3 is viewed from the side, the angle θ formed by the line L1 connecting the pair of mounting flange portions 5b and the extending direction of the center line L2 between the connection terminals 5c and 5d is The projecting length of the mounting flange portion 5b in a direction parallel to the steering column 3 and a direction perpendicular thereto is suppressed by an acute angle (for example, 60 °), thereby reducing the size.

Here, as shown in FIG. 6, each of the connection terminals 5c and 5d is disposed insulated from each other in a synthetic resin brush support 5f having an armature insertion hole in the center of the bottom, and two sets of brushes. The arc-shaped bus bars 5i and 5j individually connected to 5g and 5h are integrally formed at opposite ends.
The electric motor 5 has its mounting flange 5b splined or serrated to the motor mounting portion 17 of the reduction gear box 4 and its output shaft 5a to the worm shaft 11a to which the worm 11 is mounted, and the connection terminals 5c and 5d are connected. It is attached to the rear of the vehicle. Here, as shown in FIGS. 7 and 8, the motor mounting portion 17 has a pair of flange portions 17a formed at positions facing the mounting flange 5b of the electric motor 5b. A flat surface 17b for attaching the terminal blocks 33a and 33b of 19C and the mounting flange 43 is formed, and the electric motor 5 itself is rotated to assemble the electric motor 5 to the motor mounting portion 17 on the motor mounting end surface side of the flat surface 17b. A cutout portion 17c is formed to avoid interference with the connection terminals 5c and 5d when being made.

  Further, the control unit mounting portion 20 formed in the reduction gear box 4 is provided on the upper side of the worm storage portion 12 and the lower worm wheel storage portion 14 as is apparent with reference to FIGS. An L-shaped board mounting surface is formed by the first flat mounting surface 20a straddling and the second flat mounting surface 20b extending perpendicularly from the upper edge of the first flat mounting surface 20a to the vehicle front side. In addition, a third flat mounting surface 20c that is integrally connected to the left end side of the first flat mounting surface 20a, that is, the electric motor mounting portion 17 side is formed, and the first flat mounting surface 20c that is formed on the upper surface of the torque sensor housing portion 16 is formed. A fourth flat mounting surface 20d extending from the lower end of the flat mounting surface 20a at a right angle to the vehicle rear side is formed, and the first, second and fourth flat mounting surfaces are crank-shaped when viewed from the side. .

  An L-shaped side wall 20f connected to the fourth flat mounting surface 20d is formed at the lower end and the right end of the first flat mounting surface 20a. The side wall 20f, the first flat mounting surface 20a and the fourth flat mounting surface 20a are formed. A control board housing portion 20i for housing the control board 19A is formed by the mounting surface 20d, a power board housing portion 20k for housing the power board 19B is formed by the second flat mounting surface 20b and the side wall 20g. The flat mounting surface 20d is a mold component mounting portion 19C for mounting the mold component 19C.

  As shown in FIG. 9, the control board 19A calculates a steering assist current command value based on a torque detection value from the torque sensor 15 or a vehicle speed detection value from a vehicle speed sensor (not shown). The steering assist force generated by the electric motor 5 is controlled by performing current feedback control based on the detected value of the motor current output to the motor 5 and calculating a voltage command value to the pulse width modulation circuit of the power board 19B. 2 sets of through-holes 21a and 21b for mounting a micro control unit (MCU) and its peripheral devices, and passing through 2 sets of connection terminals 24a and 24b described later formed on the power board 19B, and a molded part Two sets of through holes 22a and 22b that pass through two sets of connection terminals 34a and 34b of 19C, and torque sensor 1 And a through hole 23a~23d which the external connection terminals 15c~15f are inserted in is formed.

  The power board 19B is mounted with an H bridge circuit composed of a power switching element such as a field effect transistor that drives and controls the electric motor 5, a pulse width modulation circuit that drives the power switching element of the H bridge circuit, and the like. It is composed of a metal substrate with high thermal conductivity that is directly fixed to the second flat mounting surface 20b through, for example, heat radiation grease, and is a lead terminal that is electrically connected to the control board 19A on the connector portion on the upper end side. Two sets of connection terminals 24a and 24b are projected upward. Here, as shown in FIG. 4, the connecting terminal 24b has a bent portion 25 formed in the middle.

  Further, as shown in FIGS. 11 and 12, the molded part 19 </ b> C has a frame 32 that is substantially tower-shaped when viewed from above and whose upper end surface is closed by the upper plate portion 31. Terminal blocks 33a and 33b are formed on the left side facing the connection terminals 5c and 5d as unit-side connection portions inclined upward so as to be in surface contact with the connection terminals 5c and 5d. A connection terminal portion 34 having two sets of connection terminals 34a and 34b, which are lead terminals electrically connected to the control board 19A, is formed on the opposite side surface, and a power connector 35 is formed on the lower end surface.

On the back side of the molded part 19C, as shown in FIG. 12, large parts are mounted for holding and holding relays 36 and 37 for power supply and failsafe, a coil 38 for noise countermeasures, and capacitors 39 and 40. A portion 41 is formed, and the lower end surface is closed with a cover 42.
Then, the molding component 19C is screwed to the upper end surface of the motor mounting portion 17 with the mounting flanges 43 formed on the left and right ends of the terminal blocks 33a and 33b, and the connection terminals 34a and 34b are inserted into the through holes 22a and 22b. At the same time, the external connection terminals 15c to 15f of the torque sensor 15 are inserted into the through holes 23a to 23d to house the control board 19A in the control board housing portion 20i, and then the power board 19B controls the connection terminals 24a and 24b. The substrate 19A is inserted through the through holes 21a and 21b, and is mounted and accommodated in the power substrate accommodating portion 20k so that the back surface thereof is in direct contact with the second flat mounting surface 20b via heat radiation grease.

Thus, when the mounting of the mold component 19C, the control board 19A, and the power board 19B to the reduction gear box 4 is completed, the state becomes as shown in FIG. 2, and in this state, the control board housing part 20i and the power board housing part 20k are connected to each other. Covering with the cover 19D shown in FIG. 4 completes the mounting of the control unit 19 to the reduction gear box 4 as shown in FIG.
In this way, the electric motor 5 is attached to the motor attachment portion 17 of the reduction gear box 4 after the attachment of the control unit 19 to the reduction gear box 4 is completed. At this time, since the output shaft 5a of the electric motor 5 and the worm shaft 11a of the reduction gear box 4 are spline-coupled or serrated-coupled, the spline coupling or serration coupling is shallowly performed while the electric motor 5 is rotated. When the shallow spline coupling or the serration coupling is completed, the electric motor mounting flange 5b is aligned with the flange portion 17a of the motor mounting portion 17 in the reduction gear box 4 and then the electric motor 5 is used as the original reduction gear box. 4 in-row coupled. As a result, the external connection terminals 5c and 5d of the electric motor 5 come into surface contact with the terminal blocks 33a and 33b formed on the molded part 19C in the control unit 19, and in this state, the external connection terminals of the electric motor 5 The electric motor 5 and the external connection terminals 33a and 34b can be electrically connected by screwing from the opposite side to the terminal blocks 33a and 33b. At the same time, the motor-side mounting flange 5 b is bolted to the flange portion 17 a of the motor mounting portion 17, so that the electric motor 5 can be mounted on the reduction box 4.

Next, the operation of the above embodiment will be described.
First, in order to assemble the electric power steering device 1, the torque sensor 15 is connected to the front end of the external connection terminals 15c to 15f in the torque sensor housing 16 of the reduction gear box 4 and the first and second flat mounting surfaces 20a and 20a. Through the opening 20e formed in the boundary part of 20b, it fixes and arrange | positions so that it may extend to a vehicle body back in parallel with the 4th mounting flat surface 20d.

  Next, the control unit 19 is mounted on the control unit mounting portion 20 of the reduction gear box 4. In mounting the control unit 19, first, the mold component 19C is mounted on the third flat mounting surface 20c. Next, in the control board 19A, the connection terminals 34a and 34b of the molded component 19C are inserted into the through holes 22a and 22b, and the external connection terminals 15c to 15f of the torque sensor 15 are inserted into the through holes 23a to 23d. In the state, it is accommodated in the control board accommodating portion 20i. Next, after applying thermal grease to the back surface of the power board 19B, the back terminals are brought into close contact with the second flat mounting surface 20b while the connection terminals 24a and 24b are inserted into the through holes 21a and 21b of the control board 19A. To do.

In this state, the through holes 21a, 21b, 22a, 22b, and 23a to 23d of the control board 19A, the connection terminals 24a and 24b of the power board 19B, and the connection terminals 34a and 34b of the molded part 19C are soldered and then covered. The mounting of the control unit 19 is completed by covering the control board housing part 20i and the power board housing part 20k with 19D.
Next, after attaching the steering shaft 2, the steering column 3, the worm 11, the worm wheel 13, and the like to the reduction gear box 4, the electric motor 5 is finally attached to the motor attachment portion 17 of the reduction gear box 4.

  In mounting the electric motor 5, first, the output shaft 5a of the electric motor 5 and the worm shaft 11a to which the worm 11 housed in the worm housing portion 12 of the reduction gear box 4 is attached are brought into contact with each other. Then, the electric motor 5 itself is splined or serrated coupled shallowly while rotating in the circumferential direction. At this time, since the notch 17c is formed on the motor mounting surface side of the motor mounting portion 17, it is possible to avoid interference with the connection terminals 5c and 5d of the electric motor 5 by this notch 17c.

  When the shallow spline coupling or serration coupling is completed, the electric motor 5 is rotated again in the circumferential direction so that the mounting flange 5b faces the flange portion 17a of the motor mounting portion 17, and the connection terminals 5c and 5d are connected to the mold part 19C. The electric motor 5 is pushed into the reduction gear box 4 in an in-row connection with the formed terminal blocks 33a and 33b facing each other.

  In this state, since the connection terminals 5c and 5d are in surface contact with the terminal blocks 33a and 33b of the molded part 19C, the connection terminals 5c and 5d and the terminal blocks 33a and 33b are screwed with a tool such as a screwdriver in this state. To do. At this time, since the connection terminals 5c and 5d and the terminal blocks 33a and 33b are inclined to the right with respect to the axial direction of the electric motor 5, a tool such as a screwdriver can be easily inserted and screwed. Can be easily performed.

  Moreover, since the connection terminals 5c and 5d and the terminal blocks 33a and 33b are inclined upward to the right with respect to the axial center direction of the electric motor 5, the contact area required for the connection terminals 5c and 5d and the terminal blocks 33a and 33b. However, the height of the terminal blocks 33a and 33b can be reduced, and the connection terminals 5c and 5d and the terminal blocks 33a and 33b can be reliably prevented from protruding more than necessary. The degree of freedom can be improved.

  In addition, since the connection terminals 5c and 5d can be brought into surface contact with the terminal blocks 33a and 33b and firmly attached at the shortest distance, the connection terminals 5c and 5d and the terminal blocks 33a and 33b can be electrically connected without a motor harness. The external connection terminals 15c to 15f of the torque sensor 15 and the through holes 23a to 23d of the control board 19A can be directly and electrically connected without using a sensor harness. For this reason, the electrical connection length between the control unit 19 and the electric motor 5 and the torque sensor 15 can be minimized, wiring resistance can be minimized, power loss can be suppressed, and electric noise can be reduced. Riding can also be reduced.

Moreover, since it is not necessary to provide a motor harness between the electric motor 5 and the control unit 19, the noise radiated from the motor harness is reduced, and the influence on the radio noise can be reduced.
Further, a second flat surface in the control unit mounting portion 20 of the reduction gear box 4 in which the power board 19B with heat generation constituting the control unit 19 is formed of any one of aluminum, aluminum alloy, magnesium and magnesium alloy. Since it is in direct contact with the mounting surface 20b via the heat dissipating grease, the heat generated by the power board 19B can be dissipated to the reduction gear box 4 as a heat mass having a large heat capacity, and the power board 19B is reliably overheated. Can be prevented.

Furthermore, by arranging the control unit 19 above the torque sensor storage portion 16 of the speed reduction box 4, the axial length of the speed reduction gear box 4 as a whole can be shortened and the size can be reduced.
In this state, after the upper mounting bracket 6 and the lower mounting bracket 7 are mounted on the vehicle body side member, the battery and the power connector 35 formed on the molded part 19C in the control unit 19 and the signal connector 26 formed on the control board 19A are respectively connected to the battery and By attaching the external connection connector connected to the ground point and the network connection connector such as CAN, the assembly of the electric power steering apparatus 1 is completed.

At this time, in the upper mounting bracket 6, as shown in FIG. 1, the sliding plate portion 6f is fixed to the capsule 6d constituting the mounting plate portion 6a by the resin injection 6e.
When the assembly of the electric power steering apparatus 1 is completed, the tilt lock state is released by rotating the tilt lever 6g of the upper mounting bracket 6, and in this state, the steering column 3 is pivoted on the pivot shaft 7c of the lower mounting bracket 7. The tilt position can be adjusted by rotating it around the center.

  When an ignition switch (not shown) of the vehicle is turned on and electric power is supplied from the battery to the control board 19A, the power board 19B, and the molded part 19C, a steering assist control process is executed by the micro control unit (MCU), and the torque sensor 15 A steering assist current command value is calculated based on a detection value of a vehicle speed sensor (not shown). 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 19B and controlling the H-bridge circuit, a motor drive current flows through the electric motor 5, and the steering assist that requires the electric motor 5 in the forward or reverse direction. Drive to generate force.

For this reason, 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 via the worm 11 and the worm wheel 13, whereby the steering wheel is It can be steered with a light steering force.
In this state, when an occupant comes into contact with a steering wheel (not shown) when a collapse occurs and an impact force that slides the steering column 3 forward acts, the gap between the capsule 6d of the upper mounting bracket 6 and the sliding plate portion 6f. By shearing the resin injection 6e, the outer tube 3b slides against the inner tube 3a while absorbing the impact force on the mounting flange 3c side of the steering column 3, and strikes the head of the bolt 18a as a contraction stopper. By contacting, the necessary collapse stroke is secured and the steering column 3 contracts.

  When the steering column 3 contracts in this way, the members attached to the periphery of the steering column 3 come close to the control unit 19, but this control unit 19 is in a position where it does not come into contact with the moving parts while ensuring a predetermined collapse stroke. In addition, since the connection terminals 5c and 5d of the electric motor 5 and the terminal blocks 33a and 33b are inclined and lowered in height, interference with moving parts is prevented so as to prevent the collapse movement. And the necessary collapse stroke can be ensured.

  Incidentally, it is conceivable that the control unit 19 is also crushed in order to secure a collapse stroke at the time of occurrence of the collapse, but this control unit 19 is configured using a part of the reduction gear box 4 as described above. It is difficult to control crushing, and there is a problem in that the amount of energy absorbed at the time of collapsing varies. However, in this embodiment, the collapsing of the control unit 19 is not considered for securing the collapse stroke. It is possible to secure an amount of energy absorption that is consistent with the set value.

  In the first embodiment, the control unit 19 individually controls the control board 19a, the power board 19b, and the mold component 19c, the control board housing portion 20i, the power board housing portion 20k, and the mold component housing portion of the reduction gear box 4. Although the case of mounting to 20 m has been described, the present invention is not limited to this, and as shown in FIG. 14, the first and fourth flat mountings are omitted by omitting the second and third flat mounting surfaces 20b and 20c. A control board 19A and a power board 19B are laminated on the surfaces 20a and 20d in such a manner that the power board 19B is in close contact with the first flat mounting surface 20a, and an insulating frame 61 and a cover in which electric parts such as a relay, a coil and a capacitor are installed. A box-type control unit 63 composed of 62 may be mounted. In this case, the motor unit of the control unit 63 is mounted. In a position corresponding to the upper end surface of the part 17 it may be to form a terminal block 64a and 64b.

  In the first embodiment, when the control unit 19 is configured, the mold part 19C is first mounted, the control board 19A is then mounted, and the power board 19B is finally mounted. However, the present invention is not limited to this, and the mold component 19C may be mounted, then the power board 19B may be mounted, and finally the control board 19A may be mounted.

Next, a second embodiment of the present invention will be described with reference to FIGS.
In the second embodiment, interference with the other members of the connection terminals 5c and 5d during the alignment of the electric motor 5 is reliably prevented.
That is, in the second embodiment, as shown in FIG. 15, the control unit 63 shown in FIG. 14 is applied as the control unit, and the connection terminals 5c and 5d of the electric motor 5 are made flexible, and the tip An arcuate warped portion 5o that warps upward is formed on the portion, and the inclination angle thereof is made larger than the inclination angles of the terminal blocks 64a and 64b, and the electric motor 5 is assembled to the motor mounting portion 17 of the reduction gear box 4 The first described above except that a slight gap is formed between the base portions of the connection terminals 5c and 5d and the lower ends of the terminal blocks 64a and 64b in the attached state by the notch portion 17c described above. The parts corresponding to those of the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  According to the second embodiment, the notch 17c is formed between the mounting end surface of the electric motor 5 and the mounting end surface of the motor mounting portion 17, and the inclination angles of the connection terminals 5c and 5d are set to the terminal block 64a and Since it is set to be larger than the inclination angle of 64b, as shown in FIG. 16, at the time of alignment when the output shaft 5a of the electric motor 5 and the worm shaft 11a of the reduction gear box 4 are spline-coupled or serrated-coupled, Even when the motor 5 itself is rotated, for example, by 10 ° from the normal mounting position, the connection terminals 5c and 5d do not interfere with the terminal blocks 64a and 64b or the end face of the motor mounting portion 17, and the alignment work is easy. It can be performed, and it is possible to reliably prevent the connection terminals 5c and 5d and the terminal blocks 64a and 64b from being damaged by this alignment work. Moreover, even if the bases of the connection terminals 5c and 5d of the electric motor 5 slightly protrude forward from the attachment end surface of the electric motor 5 due to an attachment error, the notch 17c is provided, so that interference with the notch 17c is ensured. Can be avoided.

  Further, since the inclination angles of the connection terminals 5c and 5d of the electric motor 5 are larger than the inclination angles of the terminal blocks 64a and 64b, as shown in FIG. 17, when connecting with the screws 65 from the connection terminals 5c and 5d side, The terminals 5c and 5d are tightened to the terminal blocks 64a and 64b in a bent state, and the same loosening prevention effect as that of the wave washer or the like can be exhibited. Further, the bending of the connection terminals 5c and 5d can be adjusted by a gap and an angle difference between them, and is designed in consideration of the strength of the connection terminals 5c and 5d.

Further, as shown in FIG. 18, when the electric motor 5 is assembled to the reduction gear box 4, the connection terminals 5c and 5d are difficult to contact the terminal blocks 64a and 64b even when the electric motor 5 is inserted obliquely. Even when they are in contact with each other, since the tips of the connection terminals 5c and 5d are formed in the arc-shaped warped portion 5o, damage to the connection terminals can be prevented.
In the second embodiment, the case where the stacked control unit 63 is applied as the control unit has been described. However, the present invention is not limited to this, and the control board 19A in the first embodiment described above, A control unit 19 of a type in which the power board 19B and the molded part 19C are individually attached to the reduction gear box 4 may be applied.

  In the first and second embodiments, the connection terminals 5c and 5d are provided in the electric motor 5, and the terminal blocks 33a, 33b and 64a, 64b are provided in the molded parts 19C of the control units 19 and 63. However, the present invention is not limited to this, and a terminal block may be provided in the electric motor 5 and a connection terminal may be provided in the control unit 19. Further, the motor-side connection portion of the electric motor 5 and the control unit 19 may be provided. Both of the unit side connection portions may be connection terminals having the same angle or different angles. In this case, both connection terminals may be fixed by arbitrary fixing means such as soldering, welding, rivets, screws and nuts.

  Further, in the first and second embodiments, the case where the external connection terminals 15c to 15f of the torque sensor 15 are bent in an L shape and inserted into the through holes 23a to 23d of the control board 19A has been described. In order to facilitate the insertion of the external connection terminals 15c to 15f into the through holes 23a to 23d, a funnel-shaped guide is provided on the insertion side of the external connection terminals 15c to 15f of the through holes 23a to 23d. A guide member having a surface may be provided.

  Furthermore, in the first and second embodiments, the case where the external connection terminals 15c to 15f of the torque sensor 15 are formed in an L shape has been described. However, the present invention is not limited to this, and the external connection terminals 15c to 15f are linear, and are electrically connected by soldering or fusing along the connection land formed on the control board 19A, or the external connection terminals are clipped to the control board 19A. You may make it do.

  Furthermore, in the first and second embodiments, the case where the first flat mounting surface 20a of the control unit mounting portion 20 of the reduction gear box 4 is a plane orthogonal to the central axis of the steering column 3 has been described. However, the present invention is not limited to this, and the first flat mounting surface 20 a may be a surface that is inclined with respect to a surface orthogonal to the central axis of the steering column 3.

  Moreover, in the said 1st and 2nd 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, the bus bars 5c and 5d are connected to the power supply side of the excitation coil of each phase, and the inverter circuit having, for example, a field effect transistor (FET) for driving the brushless motor on the power board 19B, and the field effect transistor of the inverter circuit A gate driving circuit for driving the gate with a pulse width modulation signal may be mounted.

1 is a perspective view showing an embodiment of an electric power steering device according to the present invention. It is a perspective view in the state where an electric motor and a control unit are attached to a reduction gear box. It is a longitudinal cross-sectional view which expands and shows a part of reduction gear box. It is a disassembled perspective view of a reduction gear box. It is a perspective view which shows an electric motor. It is a front view showing the bus bar structure of the electric motor. It is the perspective view seen from the front side of the reduction gear box. It is the perspective view seen from the back side of the reduction gear box. It is a front view which shows a control board. It is a front view which shows a power board. It is a perspective view which shows a mold component. It is the disassembled perspective view which looked at the mold component from the back side. It is a perspective view which shows the state which assembled | attached the control unit to the reduction gear box. It is a disassembled perspective view which shows the other example of a control unit. It is an expansion perspective view of the principal part which shows the 2nd Embodiment of this invention. It is a perspective view which shows the relationship between the connection terminal of the state which rotated the electric motor, and a terminal block. It is a perspective view which shows the state which connects the connection terminal of an electric motor to a terminal block. It is explanatory drawing in the case of inserting an electric motor in a reduction gear box diagonally.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Electric power steering device, 2 ... Steering shaft, 3 ... Steering column, 4 ... Reduction gear box, 5 ... Electric motor, 5c, 5d ... Connection terminal, 5i, 5j ... Bus bar, 6 ... Upper mounting bracket, 7 ... Lower Mounting bracket, 11 ... worm, 11a ... worm shaft, 12 ... worm housing portion, 13 ... worm wheel, 14 ... worm wheel housing portion, 15 ... torque sensor, 16 ... torque sensor housing portion, 17 ... motor mounting portion, 17c ... Cutout portion, 18 ... column mounting portion, 19 ... control unit, 19A ... control board, 19B ... power board, 19C ... molded part, 19C ... cover, 20 ... control unit mounting portion, 20a ... first flat mounting surface, 20b ... second flat mounting surface, 20c ... third flat mounting surface, 20d ... fourth flat mounting surface, 20i ... control Plate accommodating portion 20k ... power substrate containing part, 20 m ... molded component housing, 26 ... signal connectors 33a, 33b ... terminal block, 35 ... power connector, 63 ... control unit, 64a, 64b ... terminal block

Claims (5)

A column assist type electric power steering apparatus including 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. There,
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 is provided side by side. The electric power steering apparatus, wherein the motor-side connecting portion and the unit-side connecting portion that can come into surface contact with each other are inclined with respect to the axial center direction of the electric motor.   The electric power steering apparatus according to claim 1, wherein the motor-side connection unit and the unit-side connection unit are configured with one of a connection terminal and a terminal block.   3. The electric power steering apparatus according to claim 1, wherein the motor side connection portion is formed integrally with a bus bar that distributes power to a brush or a coil inside the electric motor. 4.   At least one of the motor side connection part and the unit side connection part is flexible, and the electric motor and the control unit are assembled to the gear box and have a predetermined gap therebetween. The electric power steering device according to any one of claims 1 to 3.   The electric power steering apparatus according to any one of claims 1 to 4, wherein the motor side connecting portion and the unit side connecting portion are screwed.

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