WO2016181795A1

WO2016181795A1 - Suspension structure for in-wheel motor drive device

Info

Publication number: WO2016181795A1
Application number: PCT/JP2016/062796
Authority: WO
Inventors: 四郎田村; 将吾岡本; 直哉竹内; 真也太向
Original assignee: Ntn株式会社
Priority date: 2015-05-13
Filing date: 2016-04-22
Publication date: 2016-11-17
Also published as: JP2016210378A

Abstract

A suspension structure (10) for an in-wheel motor drive device is provided with: a carrier (31) having an upper connection point (32c) and a lower connection point (32d), which connect to the in-wheel motor drive device (11), and holding the in-wheel motor drive device so that the in-wheel motor drive device can be steered about a king pin (K) passing through the connection points; and an arm member (21) having a free end (22) which connects to the carrier and a base end (23) which connects to a vehicle body-side member, the free end being rockable in the vertical direction relative to the base end.

Description

Suspension structure for in-wheel motor drive

The present invention relates to an in-wheel motor drive device that drives steered wheels, and more particularly to a suspension device that attaches the in-wheel motor drive device to a vehicle body.

Since the in-wheel motor drive device is arranged in the wheel (in 当該 wheel) and drives the wheel, there is no need to mount a drive source on the vehicle body unlike the conventional vehicle engine, and the internal space of the vehicle body is effectively used. can do. In addition, the drive source can be made smaller and lighter than a conventional vehicle engine.

As a suspension device that can steer a wheel that surrounds an in-wheel motor drive device, a suspension device described in, for example, Japanese Patent Application Laid-Open No. 2015-58825 (Patent Document 1) is conventionally known. FIG. 5 is a front view showing a state in which the suspension device described in Patent Document 1 is viewed in the vehicle front-rear direction. The in-wheel motor drive device 110 described in Patent Document 1 includes a wheel hub 111 that rotates about an axis O that extends in the vehicle width direction, and an arm portion 112 that extends upward from the upper part of the device above the axis O. The upper end of the arm portion 112 is rotatably connected to an upper arm 114 of a high mount double wishbone suspension device via a ball joint 113. Further, the lower part 117 of the in-wheel motor driving device 110 below the axis O is rotatably connected to the lower arm 119 of the high mount double wishbone suspension device via the ball joint 118.

The virtual straight line passing through the ball joint 113 and the ball joint 118 constitutes a kingpin K. The in-wheel motor drive device 110 can be steered around a kingpin K together with a steered wheel (not shown). The wheel hub 111 and the ball joint 118 of the in-wheel motor drive device 110 are disposed in the inner space area of the road wheel of the steered wheel.

The upper arm 114 extends in the vehicle width direction, and can swing in the vertical direction with the vehicle width direction outer end 115 coupled to the ball joint 113 as a free end and the vehicle width direction inner end 116 as a base end. The lower arm 119 can also swing in the vertical direction with the vehicle width direction outer end 120 coupled to the ball joint 118 as a free end and the vehicle width direction

inner ends

121 and 122 as base ends. Thereby, the in-wheel motor drive device 110 can bounce and rebound in the vertical direction together with a steered wheel (not shown).

The lower part 117 of the in-wheel motor drive device 110 below the axis O is connected to the lower end of the damper 123. The upper end of the damper 123 is connected to a vehicle body (not shown). The damper 123 attenuates the bounce and rebound of the in-wheel motor drive device 110.

According to the suspension device described in Patent Document 1, since the kingpin K extends across the steered wheel and is disposed near the wheel center, the kingpin offset as viewed from the wheel center is small. Therefore, the running stability is better than when the kingpin does not intersect the steered wheel.

Japanese Unexamined Patent Publication No. 2015-58825

According to the suspension device described in Patent Document 1, since the lower arm 119 is disposed adjacent to the lower side of the in-wheel motor driving device 110, the lower arm 119 is driven by the in-wheel motor when the in-wheel motor driving device 110 rebounds downward. There is a risk of interference with the device 110. Furthermore, since the free end region of the lower arm 119 is disposed in the inner space region of the steered wheel, the lower arm 119 may interfere with the load wheel of the steered wheel when the in-wheel motor drive device 110 bounces upward. Furthermore, if the in-wheel motor drive device 110 is steered at a large angle or is steered with bound and rebound, the lower arm 119 may interfere with the in-wheel motor drive device 110.

Therefore, in order to ensure the clearance, the lower arm 119 is tapered toward the in-wheel motor driving device 110, the lower arm 119 is curved, the thickness of the lower arm 119 in the vertical direction or the cross-sectional shape is reduced, etc. Measures are taken. For this reason, there was room for improvement in the ground height, strength, and rigidity of the lower arm.

In view of the above circumstances, the present invention does not interfere with the suspension member even if the in-wheel motor drive device that drives the steered wheels steers, bounces, and rebounds, and further increases the ground clearance, strength, and rigidity of the suspension member. An object of the present invention is to provide a suspension structure for mounting an in-wheel motor drive device that can be enlarged to a vehicle body.

For this purpose, the suspension structure for an in-wheel motor drive device according to the present invention has an upper connection point and a lower connection point connected to the in-wheel motor drive device, and the in-wheel motor centering on a king pin passing through these connection points. A carrier that holds the drive device in a steerable manner, and a free end that is connected to the carrier and a base end that is connected to the vehicle body side member, and the free end is provided with an arm member that can swing vertically with respect to the base end .

According to the present invention, since the free end of the arm member is separated from the in-wheel motor drive device, the in-wheel motor drive device interferes with the arm member even if the in-wheel motor drive device swings or steers. There is nothing. The carrier swings in the vertical direction with respect to the arm member together with the in-wheel motor drive device, and the in-wheel motor drive device does not swing in the vertical direction with respect to the carrier. Therefore, the degree of freedom of arrangement and shape of the arm member is increased, the cross-sectional shape of the arm member is not restricted, and the ground height, strength, and rigidity of the arm member can be increased. The vehicle body side member refers to a member attached to the vehicle body side in view of the members to be described, and includes not only the vehicle body but also a vehicle body frame attached to the vehicle body, a bracket attached to the vehicle body frame, and other parts attached to the vehicle body. Including.

By the way, it is customary that the steered wheels are disposed on the front side of the vehicle and the driver's seat is disposed on the rear side of the vehicle with respect to the steered wheels. In the conventional example shown in FIG. 5, the lower end of the damper 123 is connected to the upper part of the in-wheel motor drive device 110 in order to bring the connection point between the damper 123 and the in-wheel motor drive device 110 closer to the wheel center of the steered wheels. In this case, since the damper 123 expands and contracts in the vertical direction with the same movement amount as the bounce amount and the rebound amount of the steered wheel, the full length of the damper 123 must be secured sufficiently, and the upper end of the damper 123 extending in the vertical direction is the steered wheel. Connect to the car body at a higher position. The vehicle body becomes higher than the upper end of the damper 123. If it does so, the front view of the driver who gets on the driver's seat of vehicles provided in the back of vehicles rather than damper 123 will be diminished by the body. Increasing the height of the driver's seat to ensure visibility will also increase the center of gravity of the vehicle, reducing steering stability, and increasing the vehicle's projected area in the longitudinal direction of the vehicle and increasing running resistance. .

Therefore, the suspension structure for an in-wheel motor drive device as one embodiment of the present invention is a member extending in the vertical direction, and further includes a damper having one end connected to the vehicle body side member and the other end connected to the carrier. According to this embodiment, in the damper extending in the vertical direction, it is possible to arrange the lower end region of the damper so as to overlap with the same height position as the in-wheel motor drive device. Therefore, the upper end of the damper can be lowered than before without sacrificing the entire length of the damper, and the height of the vehicle body can be lowered to ensure the driver's front view. Further, since the carrier does not turn, even if the in-wheel motor drive device turns, the moment around the kingpin does not act on the damper, and the life of the damper is improved.

As a preferred embodiment of the present invention, the other end of the damper is connected to the lower part of the carrier. According to this embodiment, the height of the damper can be lowered, the height of the vehicle body can be further lowered, and the driver's front field of view can be widely secured to the lower side. More preferably, the other end of the damper is connected to the carrier below the axis of the in-wheel motor drive device.

As a preferred embodiment of the present invention, the upper connection point and the lower connection point are arranged in an inner space region of a wheel driven by an in-wheel motor drive device. According to this embodiment, the king pin (steering axis) can intersect with the wheel (steering wheel) that houses the in-wheel motor drive device, and the offset between the wheel center of the steered wheel and the king pin can be reduced. Therefore, when the steered wheel gets over the step, the moment around the kingpin input from the step to the steered wheel is reduced, and the running stability is improved. Further, the distance from the king pin to the center of the ground contact range between the steered wheel and the road surface can be shortened, and the moment around the king pin generated with the driving force of the steered wheel is reduced, so that traveling stability is improved.

Although the present invention does not exclude the arrangement of the free end in the inner space of the wheel driven by the in-wheel motor drive device, as a preferred embodiment, the free end of the wheel driven by the in-wheel motor drive device. Located outside. According to this embodiment, it is possible to reliably prevent the arm member from interfering with the wheel when the wheel is steered or swung.

As a further preferred embodiment of the present invention, the arm member includes an upper arm disposed on the relatively upper side and a lower arm disposed on the relatively lower side. According to this embodiment, a double wishbone suspension structure can be realized. Here, it is preferable that the upper arm and the lower arm are arranged above and below the axis of the in-wheel motor drive device, respectively.

As an embodiment of the present invention, the free end of the arm member includes a front connection point disposed on the front side in the vehicle front-rear direction and a rear connection point disposed on the rear side in the vehicle front-rear direction. According to this embodiment, the carrier can be stably attached to the vehicle body side member at a plurality of connection points.

Thus, according to the present invention, since the carrier as the intermediate member is interposed between the in-wheel motor drive device and the arm member, it is not necessary to arrange the arm member above and below the in-wheel motor drive device, Even if the in-wheel motor drive device bounces and rebounds, there is no possibility that the arm member interferes with the in-wheel motor drive device or the wheels. Further, since a carrier as an intermediate member is interposed between the in-wheel motor drive device and the arm member, it is not necessary to arrange the arm member in front and rear (vehicle longitudinal direction) of the in-wheel motor drive device. Even if the drive device steers, there is no possibility that the arm member interferes with the in-wheel motor drive device or the wheels.

It is a perspective view which shows the suspension structure for in-wheel motor drive devices which becomes one Embodiment of this invention. It is a front view which shows the same embodiment. It is a top view which shows the same embodiment. It is sectional drawing which takes out and shows a connection point from the embodiment. It is a front view which shows the conventional in-wheel motor drive device and suspension apparatus.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a perspective view showing a suspension structure for an in-wheel motor drive device according to an embodiment of the present invention. FIG. 2 is a front view showing the embodiment, and shows a state seen in the vehicle front-rear direction together with a cross section of the wheel. FIG. 3 is a plan view showing the embodiment, which is shown together with a part of the wheel.

First, the in-wheel motor drive device 11 will be described. As shown in FIGS. 1 and 2, the in-wheel motor drive device 11 includes a motor unit 11A, a reduction unit 11B, and a wheel hub unit 11C. The wheel hub portion 11 </ b> C includes a hub wheel 12 that is a rotating member and an outer ring member (not shown) that is a non-rotating member that rotatably supports the hub wheel 12. The motor unit 11A, the reduction unit 11B, and the wheel hub unit 11C are sequentially arranged in series in the direction of the axis O of the hub wheel 12 and are arranged coaxially. A wheel 14 is attached and fixed to the hub wheel 12 by bolts.

The motor unit 11A incorporates a rotor and a stator of a rotating electric machine inside the casing, drives the hub wheel 12, or regenerates electric power by using the rotation of the hub wheel 12. The speed reduction part 11B incorporates a speed reduction mechanism such as a cycloid speed reducer in the casing, and reduces the rotation of the motor part 11A and transmits it to the hub wheel 12.

The in-wheel motor drive device 11 drives the wheel 14 arranged on the outer side in the vehicle width direction of the vehicle, and is provided in the inner space area of the road wheel 15 of the wheel 14 as shown in FIG. In FIG. 1, the in-wheel motor drive device 11 is represented as a rectangular parallelepiped, but may be a cylinder having the axis O as the center. The in-wheel motor drive device 11 is attached to the vehicle body 50 via the suspension structure 10 with the wheel hub portion 11C of the in-wheel motor drive device 11 being outside in the vehicle width direction and the motor portion 11A being inside in the vehicle width direction.

Next, the suspension structure for suspending the in-wheel motor drive device on the vehicle body so as to be steerable will be described.

The suspension structure 10 of the present embodiment includes an upper arm 21 and a lower arm 24 as arm members that can swing in the vertical direction, a carrier 31 as an intermediate member interposed between the in-wheel motor drive device 11 and the arm member, and a damper 41. Is provided.

The carrier 31 has a base 31b, an upper arm 31c, and a lower arm 31d. The base 31b is disposed on the inner side in the vehicle width direction than the in-wheel motor drive device 11. The upper arm portion 31 c protrudes outward in the vehicle width direction from the upper edge of the base portion 31 b and is disposed above the in-wheel motor drive device 11. The lower arm portion 31 d protrudes outward in the vehicle width direction from the lower edge of the base portion 31 b and is disposed below the in-wheel motor drive device 11. The tip of the upper arm 31c is located in the inner space of the road wheel 15 and is connected to the upper portion of the in-wheel motor drive device 11 via the rotation shaft 32c. The tip of the lower arm 31d is also the inner space of the load wheel 15. It is located in the region and is connected to the lower part of the in-wheel motor drive device 11 via the rotation shaft 32d.

Rotating

shafts

32c and 32d extend in the vertical direction. The imaginary straight line passing through the

rotation shafts

32c and 32d serving as the two connecting points on the upper and lower sides constitutes the kingpin K. The in-wheel motor drive device 11 is further connected to a tie rod (not shown) of the steering device, and is held so as to be steerable as shown by an arrow centered on the kingpin K in FIG. Is done.

The upper upper arm 21 and the lower lower arm 24 are arranged on the inner side in the vehicle width direction with respect to the carrier 31 and spaced apart in the vertical direction. The upper arm 21 has an H shape, for example, and extends in the vehicle width direction, and has two free ends 22 on the outer side in the vehicle width direction and two base ends 23 on the inner side in the vehicle width direction. The upper arm 21 can swing up and down around the base end 23 as indicated by an arrow in FIG.

Each free end 22 is connected to the base portion 31b of the carrier 31 through the rotation shaft 33 as shown in FIG. For this reason, two brackets 34 are formed on the upper edge of the base portion 31b with an interval in the vehicle front-rear direction. Each bracket 34 supports both ends of a rotation shaft 33 extending in the vehicle front-rear direction.

Each base end 23 is connected to the vehicle body 50 via a rotating shaft 53 as shown in FIG. Since the rotation shaft 53 extends in the vehicle front-rear direction, the upper arm 21 can swing up and down around the rotation shaft 53 of the base end 23.

The lower arm 24 has the same shape as the upper arm 21 and has two free ends 25 on the outer side in the vehicle width direction and two base ends 26 on the inner side in the vehicle width direction. Each free end 25 is connected to the lower edge of the base portion 31 b via a rotation shaft 35, and each base end 26 is connected to the vehicle body 50 via a rotation shaft 56. For this reason, two brackets 36 are formed at the lower edge of the base portion 31b with a space in the vehicle longitudinal direction. Each bracket 36 supports both ends of a rotation shaft 35 extending in the vehicle front-rear direction. The lower arm 24 can also swing up and down about the base end 26 as shown by the arrow in FIG.

The damper 41 is a member extending in the vertical direction, and is disposed above the lower arm 24. The upper end of the damper 41 is connected to the vehicle body 50 above the upper arm 21, and the lower end of the damper 41 is connected to the lower part of the carrier 31 via the rotating shaft 38 below the upper arm 21. Therefore, the damper 41 is passed through the H-shaped upper arm 21. In particular, the lower end of the damper 41 is connected to the carrier 31 below the axis O of the in-wheel motor drive device 11, and the height position of the lower end region of the damper 41 is the height region of the carrier 31 and the in-wheel motor drive device 11. Overlap. The lower end of the damper 41 is formed in a cylindrical body, and a rotating shaft 38 extending in the vehicle front-rear direction is passed through the cylindrical body. A bracket 39 is formed on the base 31 b of the carrier 31. The bracket 39 supports both ends of the rotation shaft 38.

The free ends 22 and 25 and the lower end of the damper 41 are all formed in the same cylindrical body and are connected to

brackets

34, 36 and 39 having the same shape provided on the carrier 31, respectively. The base ends 23 and 26 are also connected to brackets of the same shape provided on the vehicle body 50, respectively. The connection structure of the free end 22 and the bracket 34 is taken out as a representative of these, and is enlarged and shown in FIG. A bush 37 that is a rubber cylindrical body is provided in an annular space between the free end 22 and the rotation shaft 33 that is passed through the central hole of the free end 22. The carrier 31 on the bracket 34 side can rotate around the rotation shaft 33 extending in the vehicle front-rear direction with respect to the upper arm 21 on the free end 22 side. Perpendicular movement is allowed.

Here, the carrier 31 is T-shaped as shown in FIG. 3 when viewed in the vertical direction, and the upper arm portion 31c of the carrier 31 is the center between the front bracket 34 and the rear bracket 34, that is, the front-rear direction of the base portion 31b. Located in the center. The same applies to the lower arm 31d. The bracket 39 is also disposed at the center in the front-rear direction of the base 31b.

Next, the operation of the suspension structure 10 will be described.

When the upper arm 21 and the lower arm 24 swing up and down around the base ends 23 and 26, the free ends 22 and 25 of the upper arm 21 and the lower arm 24 connected to the carrier 31 move up and down. Thereby, the carrier 31, the in-wheel motor drive device 11, and the wheel 14 bounce upward with respect to the vehicle body 50 or rebound downward. At the same time, the damper 41 expands and contracts in the vertical direction. The damper 41 is passed through the coil spring 42. The coil spring 42 alleviates a sudden expansion / contraction change of the damper 41. The damper 41 and the coil spring 42 constitute a shock absorber.

In addition to the bounce and rebound of the in-wheel motor drive device 11, the in-wheel motor drive device 11 steers the carrier 31 around the kingpin K together with the wheels 14.

By the way, according to the present embodiment, the suspension structure 10 that suspends the in-wheel motor drive device 11 from the vehicle body 50 so as to be steerable includes the carrier 31 and the upper arm 21 and the lower arm 24 as arm members. The carrier 31 is connected to an in-wheel motor drive device via a rotation shaft 32c that is an upper connection point and a rotation shaft 32d that is a lower connection point, and the in-wheel motor is centered on a kingpin K that passes through these connection points. The drive device 11 is held so as to be steerable. The arm member has free ends 22 and 25 connected to the carrier 31 and base ends 23 and 26 connected to the vehicle body 50, and the free ends 22 and 25 can swing vertically with respect to the base ends 23 and 26. According to such an embodiment, since the arm member swings in the vertical direction and the in-wheel motor drive device 11 is steered separately, the free ends 22 and 25 of the arm member are arranged so as to overlap the kingpin K. There is no need, and it is not necessary to arrange the arm member in a narrow annular space between the load wheel 15 and the in-wheel motor drive device 11, and the shape and cross-sectional dimensions of the arm member can be freely determined. Therefore, an arm member can be arrange | positioned in the position away from the in-wheel motor drive device 11, and interference with an arm member and the in-wheel motor drive device 11 can be avoided. In addition, the shape and cross-sectional dimensions of the arm member can be determined so as to ensure the minimum ground clearance, strength, and rigidity of the arm member.

In addition, according to the present embodiment, the damper 41 further includes a damper 41 that extends in the vertical direction and that has an upper end connected to the vehicle body 50 and a lower end connected to the lower portion of the carrier 31. be able to. Therefore, the height position of the vehicle body 50 can also be lowered, and the front view of the driver who is seated behind the damper 41 can be secured.

In addition, according to the present embodiment, the pivot shaft 32 c serving as the upper connection point and the pivot shaft 32 d serving as the lower connection point are disposed in the inner space of the road wheel 15, so that the kingpin K crosses the wheel 14. Thus, the running stability of the vehicle is improved.

Further, according to the present embodiment, the free ends 22 and 25 are disposed outside the wheel 14, that is, on the inner side in the vehicle width direction than the wheel 14, so that even if the wheel 14 swings or steers, the arm member and the wheel 14. Can be reliably avoided.

Further, according to the present embodiment, the arm member includes the upper arm 21 disposed on the relatively upper side and the lower arm 24 disposed on the relatively lower side, so that a double wishbone suspension structure can be realized. it can.

Further, according to the present embodiment, the free end 22 of the upper arm 21 is arranged at the front connection point arranged on the front side in the vehicle front-rear direction and the rear end arranged on the rear side in the vehicle front-rear direction as shown in FIG. Since the side connection point is included, the carrier 31 can be stably attached to the vehicle body 50 at a plurality of connection points. Further, the upper arm 21 can be formed in an H shape, for example, and a member such as the damper 41 can be passed through the upper arm 21. The same applies to the free end 25 of the lower arm 24 (FIG. 1).

The embodiment of the present invention has been described above with reference to the drawings, but the present invention is not limited to the illustrated embodiment. Various modifications and variations can be made to the illustrated embodiment within the same range or equivalent range as the present invention.

The suspension structure for an in-wheel motor drive device according to the present invention is advantageously used in electric vehicles and hybrid vehicles.

10 suspension structure, 11 in-wheel motor drive, 12 hub wheel, 14 wheels, 15 road wheel, 21 upper arm, 22, 25 free end, 23, 26 base end, 24 lower arm, 31 carrier, 31b base, 31c upper arm, 31d lower arm, 32c, 32d, 33, 35, 38 pivot axis, 34, 36, 39 bracket, 37 bush, 41 damper, 42 coil spring, 50 body (vehicle body side member), 53, 56 pivot axis, K kingpin, O axis.

Claims

A suspension structure for attaching an in-wheel motor drive to a vehicle body,
A carrier that has an upper connection point and a lower connection point that are connected to the in-wheel motor drive device, and that holds the in-wheel motor drive device in a steerable manner around a king pin that passes through these connection points;
A suspension structure for an in-wheel motor drive device having a free end connected to the carrier and a base end connected to a vehicle body side member, the free end including an arm member swingable in a vertical direction with respect to the base end. .
The suspension structure for an in-wheel motor drive device according to claim 1, further comprising a damper that is a member extending in a vertical direction, one end of which is connected to the vehicle body side member and the other end is connected to the carrier.
The suspension structure for an in-wheel motor drive device according to claim 2, wherein the other end of the damper is connected to a lower portion of the carrier.
The suspension for an in-wheel motor drive device according to any one of claims 1 to 3, wherein the upper connection point and the lower connection point are arranged in an inner space region of a wheel driven by the in-wheel motor drive device. Construction.
The suspension structure for an in-wheel motor drive device according to any one of claims 1 to 4, wherein the free end is disposed outside a wheel driven by the in-wheel motor drive device.
The suspension structure for an in-wheel motor drive device according to any one of claims 1 to 5, wherein the arm member includes an upper arm disposed on a relatively upper side and a lower arm disposed on a relatively lower side.
The free end includes a front connection point disposed on the front side in the vehicle front-rear direction and a rear connection point disposed on the rear side in the vehicle front-rear direction. Suspension structure for in-wheel motor drive.