JP2020111191A - Suspension structure for in-wheel motor driving device - Google Patents

Abstract

To provide a suspension structure which enables reduction of a vehicle height compared to a conventional structure for an in-wheel motor and achieves improvement of quietness.SOLUTION: Inner ends 48b, 48C as seen in a vehicle width direction of a lower arm 48 are connected to a vehicle body side member and an outer end 48a as seen in the vehicle width direction of the lower arm 48 is connected to an in-wheel motor driving device 10 to enable the lower arm 48 to swing in a vertical direction around an axis passing through the inner ends 48b, 48c in a vehicle width direction. One end part 45b of a torsion bar spring 45 is fixed to the lower arm 48 and the other end part 45e is fixed to the vehicle body side member. The torsion bar spring 45 is twisted and deformed between the one end part 45b and the other end part 45e by swinging of a suspension arm 48.SELECTED DRAWING: Figure 3

Description

The present invention relates to a suspension device that connects an in-wheel motor drive device arranged inside a wheel to a vehicle body side member.

An in-wheel motor that is arranged in an inner space of a road wheel and drives the road wheel is disclosed in Japanese Patent No. 4511976 (Patent Document 1) and Japanese Patent Laid-Open No. 2018-047831 (Patent Document 2). A suspension device is known in which a shock absorber is arranged above the shock absorber, and an in-wheel motor is connected to the vehicle body via the shock absorber. The shock absorber has a telescopic damper extending in the vertical direction, and a coil spring arranged so as to surround the shock absorber. A disc-shaped lower coil spring seat that supports the lower end of the coil spring is provided at the center of the shock absorber.

Japanese Patent No. 4511976 JP, 2018-047831, A

However, the present inventor has found that there is a point to be further improved in the above-described conventional suspension device. In other words, the dish-shaped spring seat is arranged above the road wheel, and a tire (not shown) is attached to the outer periphery of the road wheel. If this is the case, it will be necessary to take measures such as raising the upper end of the shock absorber and the vehicle height, or installing flat tires on the road wheel, so that the tires and the lower coil spring seat do not interfere with each other, and it may not be possible to satisfy the vehicle height limit requirements. Or, it may not be possible to install normal tires.

The coil spring is a component that receives the vehicle weight.If the axial position of the upper end of the damper and the axial position of the tire ground contact point are misaligned, the vehicle weight is applied to the damper, and the bending moment accompanying this vehicle weight acts on the damper. Resulting in. Then, it is necessary to increase the bending strength of the damper such as making the damper thick, which causes a problem that the unsprung weight of the suspension structure becomes heavy.

Further, the vibration of the in-wheel motor is transmitted to the coil spring, and the vibration is amplified due to the resonance of the coil spring, which may worsen the noise in the vehicle interior. As an example of the resonance mode of the coil spring, when the tire moves in the vehicle front-rear direction due to the driving force, the coil spring bends and resonates in the front-rear direction, causing large vibrations to be transmitted to the vehicle body and worsening vehicle interior noise.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an improved suspension structure for an in-wheel motor.

For this purpose, the suspension structure for an in-wheel motor drive device according to the present invention has a base end connected to a vehicle body side member, a free end connected to the in-wheel motor drive device, and a vertical direction about an axis passing through the base end. And a torsion bar spring, one end of which is fixed to the suspension arm and the other end of which is fixed to the vehicle body member. The torsion bar spring is attached to the one end of the suspension arm as the suspension arm swings. And is twisted and deformed between the other ends.

According to the present invention, the coil spring of the shock absorber can be replaced with the torsion bar spring. Therefore, the coil spring seat becomes unnecessary, and the shock absorber damper can be provided at a lower position in the vertical direction than in the conventional case, and the upper end of the shock absorber can be lowered. Even if normal tires are attached to the road wheel, they will not interfere with the lower coil spring seat. Further, since the coil spring can be omitted, the vehicle weight is not applied to the damper, and the bending moment due to the vehicle weight does not act on the damper. Further, by eliminating the coil spring, there is no fear that the coil spring resonates due to the vibration of the in-wheel motor drive device, and the noise in the vehicle compartment does not deteriorate.

The suspension arm may be located above the axis of the wheel or below the axis of the wheel. The shape of the suspension arm is not particularly limited and may be A-type, H-type, I-type, V-type or the like. As one aspect of the present invention, the suspension arm has a plurality of base ends, and one end of the torsion bar spring is fixed to each of the plurality of base ends. As another aspect, one end of the torsion bar spring is fixed to a single base end.

The torsion bar spring is in principle straight, but it may be curved or have another shape. The extending direction of the torsion bar spring is not particularly limited. For example, the torsion bar springs are arranged substantially parallel to the vehicle front-rear direction, or substantially parallel to the vehicle width direction, or arranged in the vehicle front-rear direction and the vehicle width direction, that is, diagonally. As one aspect of the present invention, one end of the torsion bar spring and the base end of the suspension arm are arranged in front of the vehicle with respect to the free end of the suspension arm, and the other end of the torsion bar spring is behind the free end of the vehicle. Is located in. According to this aspect, since the torsion bar springs are arranged obliquely, the other end of the torsion bar springs does not excessively project in the vehicle front-rear direction than the in-wheel motor drive device.

As a preferred aspect of the present invention, the suspension arm further includes a damper having an upper end connected to the vehicle body-side member and a lower end connected to the in-wheel motor drive device, and the suspension arm is disposed below the damper. According to this aspect, the suspension arm of the present invention can be applied as a lower arm of a suspension device.

As another aspect of the present invention, the suspension arm is an upper arm that is connected to an upper portion of the in-wheel motor drive device, and further includes a lower arm that is disposed below the upper arm and that is connected to a lower portion of the in-wheel motor drive device. According to this aspect, the suspension arm of the present invention can be applied as the upper arm of the suspension device.

As described above, according to the present invention, the vertical position of the damper can be made lower than that of the conventional strut, and the vehicle height limit of the electric vehicle can be satisfied. Moreover, the bending moment acting on the damper can be eliminated. The risk that the vibration of the in-wheel motor drive device is amplified by the coil spring and transmitted to the vehicle interior space is eliminated.

1 is a side view showing a suspension structure for an in-wheel motor drive device according to a first embodiment of the present invention. It is a top view showing the embodiment. It is a rear view which shows the same embodiment. It is a top view which shows the modification of 1st Embodiment. It is a top view which shows the other modification of 1st Embodiment. It is a rear view which shows another modification of 1st Embodiment. It is a top view showing the modification. It is a bottom view showing the modification. It is a front view which shows 1st Embodiment typically. It is a side view which shows the suspension structure for in-wheel motor drive devices which become 2nd Embodiment of this invention. It is a rear view which shows the same embodiment. It is a perspective view showing the embodiment.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a side view showing a suspension structure for an in-wheel motor drive device according to a first embodiment of the present invention, showing a state viewed from the vehicle width direction inner side (inboard side). FIG. 2 is a plan view showing the same embodiment. FIG. 3 is a rear view showing the same embodiment and shows a state as viewed in the vehicle front-rear direction. As shown in FIG. 3, the in-wheel motor drive device 10 is arranged in an inner space of the road wheel W and is drivingly coupled to the road wheel W.

Tires T are mounted on the outer periphery of the road wheel W. The road wheel W and the tire T form a wheel. The wheels are steered wheels that are steered in the left-right direction by the tie rod 67 together with the in-wheel motor drive device 10. The in-wheel motor drive device 10 is attached to the strut suspension device 40. The strut type suspension device 40 is arranged on each of a pair of front wheels among the four wheels arranged on the front, rear, left and right of the electric vehicle.

The in-wheel motor drive device 10 includes a wheel hub bearing portion 11, a motor portion 21, and a speed reduction portion 31. The wheel hub bearing portion 11 is a rolling bearing that has a rotating wheel, a fixed wheel, and a plurality of rolling elements and supports the vehicle weight, and its axis O extends in the vehicle width direction. The rotating wheel of the wheel hub bearing 11 is attached and fixed to the road wheel W. The wheel hub bearing portion 11 is arranged on one side in the axis O direction (vehicle width direction outer side/outboard side), and the motor portion 21 is arranged on the other side in the axis line O direction (vehicle width direction inner side/inboard side) to reduce the speed. The portion 31 is arranged in the central portion in the direction of the axis O.

The motor unit 21 is an electric motor and drives the rotating wheels of the wheel hub bearing unit 11. The motor portion 21 is arranged so as to be offset from the axis O of the wheel hub bearing portion 11 in the vehicle front-rear direction. The motor unit 21 of the present embodiment is arranged biased toward the vehicle front side of the in-wheel motor drive device 10. The motor rotation shaft of the motor unit extends parallel to the axis O. The speed reducer 31 is a parallel shaft gear reducer, and an input shaft connected to the motor rotation shaft of the motor unit 21, a single or a plurality of intermediate shafts, and an output shaft connected to the rotary wheel are provided on these shafts, respectively. It has a plurality of gears and decelerates the rotation of the input shaft and transmits it to the output shaft.

The strut suspension device 40 has a damper 44, a torsion bar spring 45, and a lower arm 48. The damper 44 extends in the vertical direction, the damper outer cylinder 42 on the lower end side is connected to the in-wheel motor drive device 10 for the steered wheels, and the damper upper end 43 is attached to the vehicle body (not shown) via the upper mount 74. The vehicle body is a member on the vehicle body side when viewed from the damper 44. The vehicle body side member refers to a member that is connected to the vehicle body side when viewed from the members to be described.

The in-wheel motor drive device 10 includes a carrier member 60. The damper outer cylinder 42 is coupled to the upper end 61 of the carrier member 60 below the uppermost portion of the in-wheel motor drive device 10. The carrier member 60 extends in the vertical direction, the vertical center portion 62 is connected and fixed to the in-wheel motor drive device 10, and the vehicle weight is transmitted to the wheel hub bearing portion 11 via the in-wheel motor drive device 10. The lower end 63 of the carrier member 60 is rotatably connected to the vehicle width direction outer end 48a of the lower arm 48 via a ball joint 49. The ball joint 49 is arranged below the in-wheel motor drive device 10. The lower end 63, the vehicle width direction outer end 48a, and the ball joint 49 are arranged in the inner space of the road wheel W. The lower end 63, the vehicle width direction outer end 48a, and the ball joint 49 are arranged substantially directly below the axis O. The ball joint 49 is a connection point between the in-wheel motor drive device 10 and the lower arm 48.

The steering axis K defines the steering axis K with the damper upper end 43 and the ball joint 49. The steered axis K is a straight line passing through the damper upper end 43 and the ball joint 49. Since the ball joint 49 is arranged in front of the vehicle with respect to the damper upper end 43, the strut suspension device 40 has a caster angle.

To add to the description of the damper 44, the damper outer cylinder 42 projects downward from the upper end 61. Therefore, the vertical position of the damper outer cylinder 42 overlaps the vertical position of the in-wheel motor drive device 10. The damper 44 has a stroke area on the upper end side, and the stroke area is covered with the dust boot 41. The dust boot 41 is arranged above the upper end 61. The outer diameter dimension of the dust boot 41 is substantially the same as the outer diameter dimension of the damper outer cylinder 42.

In a general strut type suspension device, a coil spring and a damper are integrated to form a strut, whereas in the present embodiment, a torsion bar spring 45 is used instead of providing the coil spring. Therefore, according to this embodiment, since the coil spring does not exist, the damper 44 can be arranged outside in the vehicle width direction, and the damper 44 can be brought closer to the tire T.

Further, according to the present embodiment, since the lower end of the damper 44 is arranged so as to approach the lower end 63 of the carrier member 60, the damper upper end 43 can be arranged at a lower position as compared with the upper end of the conventional strut. it can.

Returning the description to the carrier member 60, the lower end 63 of the carrier member 60 is arranged in front of the upper end 61 of the vehicle. The center portion of the carrier member 60 may or may not intersect with the axis O, but is arranged so as to be biased toward the rear of the vehicle when viewed from the axis O.

An arm portion 64 is formed at the center of the carrier member 60 in the vertical direction. The arm portion 64 projects from the carrier member 60 in the vehicle front-rear direction. In the present embodiment, the arm portion 64 projects rearward of the vehicle. The tip of the arm portion 64 is rotatably connected to the vehicle width direction outer end of the tie rod 67. The tie rod 67 extends in the vehicle width direction, and the vehicle width direction inner end 67n of the tie rod 67 is connected to a steering device (not shown). The steering device pushes and pulls the arm portion 64 in the vehicle width direction via the tie rod 67, whereby the in-wheel motor drive device 10 is steered to the left and right. As a result, the wheels are steered around the steered axis K together with the in-wheel motor drive device 10, and the electric vehicle turns. Further, the driving force of the in-wheel motor drive devices 10 arranged on the left and right of the electric vehicle is controlled independently. This controls the yaw moment of the electric vehicle.

The lower arm 48 is an A-type suspension arm having vehicle width direction inner ends 48b, 48c and vehicle width direction outer end 48a. The lower arm 48 is rotatably connected to a subframe (not shown) at two vehicle width direction inner ends 48b and 48c. The connecting portion is, for example, via a rubber bush having a cylindrical shape. A straight line passing through the vehicle width direction inner ends 48b and 48c extends in the vehicle front-rear direction and constitutes an axis Lx. The subframe and the vehicle body are members on the vehicle body side when viewed from the lower arm 48. The lower arm 48 is vertically swingable with the vehicle width direction inner ends 48b and 48c as base ends and the vehicle width direction outer end 48a as a free end. The axis Lx is the swing center. As the lower arm 48 swings in the vertical direction, the damper 44 expands and contracts in the vertical direction to dampen the bound/rebound of the in-wheel motor drive device 10.

The vehicle width direction inner end 48b is located on the vehicle width direction inner side of the in-wheel motor drive device 10 and is disposed substantially directly below the axis O. On the other hand, the vehicle width direction inner end 48c is arranged so as to be displaced from the axis O in the vehicle front-rear direction. The vehicle width direction inner end 48c of the present embodiment is disposed rearward of the vehicle with respect to the in-wheel motor drive device 10.

The torsion bar spring 45 extends straight along the axis Lx. The torsion bar spring 45 may extend in line with the axis Lx, or may be slightly apart from the axis Lx. One ends 45b of the torsion bar springs 45 are fixed to vehicle width direction inner ends 48b and 48c, respectively. A tip portion of the one end portion 45b is inserted and fixed to a vehicle width direction inner end 48b in front of the vehicle, and an intermediate portion of the one end portion 45b is fixed so as to penetrate a vehicle width direction inner end 48c in the vehicle rear direction. The other end portion 45e of the torsion bar spring 45 is fixed to a vehicle body-side member (not shown) at the vehicle rear side with respect to the lower arm 48.

The torsion bar spring 45 and the lower arm 48 are fixed by serration, spline, bolt, or welding. In the present embodiment, as shown by the broken lines in FIGS. 1 and 2, a convex portion 45f is formed on the outer peripheral surface of the torsion bar spring 45, and the convex portion 45f engages with the vehicle width direction inner end 48c so as not to be rotatable relative to each other. .. The central region 45d of the torsion bar spring 45 extends below the vehicle body (not shown) in the vehicle front-rear direction without interfering with any member.

The other end portion 45e is restrained by the vehicle body side member from rotating. The torsion bar spring 45 can be twisted and deformed so that one end portion 45b rotates relative to the other end portion 45e. As the lower arm 48 swings, the torsion bar spring 45 is twisted and deformed. In the present embodiment, the carrier member 60 supports the vehicle weight and sinks downward, and the lower arm 28 rotates downward, while the torsion bar spring 45 is twisted and deformed to apply a reaction force to the lower arm 28. This balances the vehicle weight with the reaction force of the torsion bar spring 45.

When the wheel bounces or rebounds due to the unevenness of the road surface, the lower arm 28 rotates, and the torsion bar spring 45 is also twisted and deformed according to the rotation of the lower arm 28.

In the suspension structure for the in-wheel motor drive device of the present embodiment, the vehicle width direction inner ends 48b and 48c that are the base ends are connected to the vehicle body side member, and the vehicle width direction outer end 48a that is the free end is the in-wheel motor drive device. 10, a lower arm 48 that is vertically swingable about an axis Lx passing through the vehicle width direction inner ends 48b and 48c, one end portion 45b is fixed to the lower arm 48, and the other end portion 45e is a member on the vehicle body side. The torsion bar spring 45 is fixed to the torsion bar spring 45. The torsion bar spring 45 is twisted and deformed between the one end portion 45b and the other end portion 45e as the lower arm 48 swings.

In this embodiment, since the torsion bar spring 45 receives the vehicle weight, it is not necessary to provide a coil spring around the damper 44, and it is not necessary to provide the damper 44 with an upper coil spring seat and a lower coil spring seat. That is, a shock absorber in which a coil spring is arranged around the damper unlike the general strut is not required. Therefore, the vertical position of the damper 44 is not limited, and the vertical position of the damper 44 and the vertical position of the in-wheel motor drive device 10 can be overlapped to lower the vertical position of the damper 44. And the demand for vehicle height restriction can be satisfied. Further, there is no limitation on the flatness of the tire T.

Further, since the vehicle weight is not applied to the damper 44, the bending moment acting on the damper 44 can be reduced. Therefore, the damper can be made thinner to reduce the bending strength, and the weight can be reduced, and the unsprung weight of the suspension structure can be reduced. In a general strut, the vehicle weight is supported by a coil spring that extends spirally around the damper, but according to the present embodiment, the upper mount 74 of the damper upper end 43 does not have to bear the vehicle weight.

In addition, since the coil spring included in a general strut can be eliminated, the vibration of the in-wheel motor is not transmitted to the coil spring, and the vibration is not amplified due to the resonance of the coil spring. Noise does not worsen.

Further, in the case of a general strut, the vibration of the in-wheel motor drive device is transmitted to the bulkhead (partition of the passenger compartment) arranged near the upper mount via the damper upper end 43 and the upper mount 74, and the bulkhead is transmitted. However, there is a possibility that the membrane vibration may worsen the noise and vibration in the passenger compartment. According to the present embodiment, the vibration transmission path using the in-wheel motor drive device as the vibration source is replaced by the torsion bar spring 45, so that vibration of the bulkhead can be eliminated or reduced.

Next, a modified example of the present invention will be described. FIG. 4 is a plan view showing a modified example of the present invention. With respect to this modification, the same components as those of the above-described embodiment are designated by the same reference numerals, and the description thereof will be omitted. Different configurations will be described below. In the embodiment of FIG. 2 described above, the torsion bar spring 45 extends from the lower arm 48 toward the rear of the vehicle, whereas in the modification of FIG. 4, the torsion bar spring 45 extends from the lower arm 48 toward the front of the vehicle. The modified example also exhibits the same effect as the above-described embodiment.

Next, another modification of the present invention will be described. FIG. 5 is a plan view showing another modification of the present invention. With respect to other modified examples, configurations common to the above-described embodiment are denoted by the same reference numerals, and the description thereof will be omitted. Different configurations will be described below. In another modification, the torsion bar spring 45 is arranged apart from the base end of the lower arm 48 (the inner end 48b in the vehicle width direction), and the one end portion 45c of the torsion bar spring 45 is arranged at the base end (the inner end in the vehicle width direction) of the lower arm 48. It is fixed to 48c). The inner end 48b in the vehicle width direction is rotatably connected to a vehicle body side member (not shown) via a rubber bush 78. The axis of the rubber bush 78 coincides with the axis Lx. The other modified examples also exhibit the same effect as the above-described embodiment.

Next, still another modification of the present invention will be described. FIG. 6 is a side view showing still another modified example of the present invention, showing a state viewed from the vehicle width direction inner side (inboard side). FIG. 7 is a plan view showing the modification. FIG. 8 is a bottom view showing the modification. With respect to still another modification, the same components as those in the above-described embodiment are designated by the same reference numerals, and the description thereof will be omitted. Different configurations will be described below. In still another modification, a plurality of I-type lower arms 51 and 52 are provided instead of the above-mentioned A-type suspension arm.

The lower arms 51 and 52 extend in the vehicle width direction and are arranged at intervals in the vehicle front-rear direction. An outer end of the lower arm 52 in the vehicle width direction is connected to a lower end 63 of the carrier member 60 via a ball joint (not shown). The outer end of the lower arm 51 in the vehicle width direction is connected to the lower portion of the casing of the speed reducing portion 31 or the lower end 63 of the carrier member 60 via a ball joint (not shown). The vehicle width direction inner ends 51b and 52c of the lower arms 51 and 52, respectively, are rotatably connected to a vehicle body side member (not shown).

The vehicle width direction inner end 51b has an axis Ly. The vehicle width direction inner end 52c has an axis Lz. The axis Lz is substantially parallel to the vehicle front-rear direction, but the axis Ly extends toward the vehicle rear side from the vehicle width direction inner end 51b toward the vehicle width direction inner side. The lower arm 51 extends at a right angle or a substantially right angle with respect to the axis Ly. The lower arm 52 also extends at a right angle or a substantially right angle with respect to the axis Lz.

The outer ends of the lower arms 51, 52 in the vehicle width direction are arranged close to each other, while the inner end 51b of the lower arm 51 in the vehicle width direction is sufficiently separated in front of the vehicle from the inner end 52c of the lower arm 52 in the vehicle width direction. Will be placed. In the present embodiment, the vehicle width direction inner end 51b is arranged in front of the vehicle with respect to the in-wheel motor drive device 10, and the vehicle width direction inner end 52c is arranged immediately below the axis O. Alternatively, as a modification not shown, the vehicle width direction inner end 52c is disposed rearward of the vehicle with respect to the axis O.

The vehicle width direction inner end 51b is further fixed to one end portion 45b of the torsion bar spring 45. The torsion bar spring 45 extends straight along the axis Ly. The other end 45e of the torsion bar spring 45 is fixed to a vehicle body-side member (not shown) behind the in-wheel motor drive device 10 in the vehicle.

Still another modification also exhibits the same effect as that of the above-described embodiment. Further, since the torsion bar spring 45 extends obliquely, the vehicle front-rear direction position of the other end portion 45e can be overlapped with the wheel (tire T) vehicle front-rear direction position.

FIG. 9 is a front view schematically showing the first embodiment and shows a state as viewed in the vehicle front-rear direction. An inner end in the vehicle width direction of the lower arm 48 is connected to the subframe 71 of the vehicle body. Both sides of the sub-frame 71 in the vehicle width direction are connected to the left and right lower arms 48, respectively. The sub frame 71 is connected to a main frame 73 of the vehicle body via a mount member 72. Both side portions 73b in the vehicle width direction of the main frame 73 are connected to the damper upper end 43 via the upper mounts 74, and are supported by the damper upper end 43 from below. The vehicle body from the sub frame 71 to the main frame 73 is a vehicle body side member when viewed from the strut suspension device 40.

In a general strut, a coil spring is attached to the outer peripheral space CS surrounding the upper end region of the damper 44, and the coil spring bears the vehicle weight. On the other hand, in this embodiment, the torsion bar spring 45 is provided instead of the coil spring. Therefore, the outer peripheral space CS for the coil spring becomes unnecessary, and the tire T and the road wheel can be arranged in the outer peripheral space CS and can be brought close to the damper 44.

Further, in this embodiment, a plurality of power lines 75 are arranged in the outer peripheral space CS. One end of each power line 75 is connected to the in-wheel motor drive device 10. The other end of each power line 75 is connected to an inverter (not shown) mounted on the main frame 73. The power line 75 supplies electric power to the in-wheel motor drive device 10 from the vehicle body side.

One end side region 75b of the power line 75 is wired in an inverted U shape in the outer peripheral space CS along the damper 44. The other end side region 75c is arranged in a U shape inside the damper 44 in the vehicle width direction. The boundary portion of the power line 75 that changes from the inverted U-shape to the U-shape is gripped by the clamp member 76. The clamp member 76 is provided on the damper outer cylinder 42, protrudes inward in the vehicle width direction from the damper 44, and bundles the plurality of power lines 75.

Since the in-wheel motor drive device 10 and the suspension device are arranged in the restricted space of the wheel house 77, it is difficult to secure a sufficient length of the power line extending from the in-wheel motor drive device 10 to the vehicle body. is there. According to the present embodiment, since the power line 75 can be wired in an inverted U shape and a U shape, the power line 75 can be lengthened in the limited space of the wheel house 77. As the power line 75 is longer, the bending amount of the power line 75 can be reduced when the in-wheel motor drive device 10 is steered, bound, or rebounded, and bending fatigue of the power line 75 is reduced.

Next, a second embodiment of the present invention will be described. FIG. 10 is a side view showing a suspension structure for an in-wheel motor drive device according to a second embodiment of the present invention, showing a state as viewed from the inside (inboard side) in the vehicle width direction. FIG. 11 is a rear view showing the same embodiment and shows a state as viewed in the vehicle front-rear direction. FIG. 12 is a perspective view showing the same embodiment. The in-wheel motor drive device 10 is attached to the double wishbone suspension device 50. The double wishbone suspension device 50 includes a damper 46, an upper arm 53, and a lower arm 48.

The upper arm 53 is a V-type or A-type suspension arm, is disposed above the axis O, and is connected to the upper end 66 of the carrier member 65 via a ball joint (not shown) at the vehicle width direction outer end 53a. The lower arm 48 is disposed below the axis O, and is connected to the lower end 63 of the carrier member 65 at the vehicle width direction outer end 48a via a ball joint (not shown).

The V-shaped or A-shaped upper arm 53 includes a front arm portion and a rear arm portion extending in the vehicle width direction. The vehicle width direction inner end 53b of the front arm portion and the vehicle width direction inner end 53c of the rear arm portion are rotatably connected to a vehicle body-side member (not shown) to form a common axis Lw. The axis Lw extends in the vehicle front-rear direction. The upper arm 53 can swing in the vertical direction about the axis Lw. Further, the vehicle width direction inner ends 53b and 53c are fixed to one end portion 45b of the torsion bar spring 45.

The torsion bar spring 45 extends straight along the axis Lw. The other end portion 45e of the torsion bar spring 45 is arranged rearward of the vehicle with respect to the in-wheel motor drive device 10.

The damper 46 is arranged between the front arm portion and the rear arm portion of the upper arm 53, and extends in the vertical direction. The damper lower end 47 of the damper 46 is rotatably connected to the lower arm 48 via a pivot shaft 47s. The damper 46 damps the bound and rebound of the in-wheel motor drive device 10.

The second embodiment also exhibits the same effects as the above-described embodiments.

Although the embodiments of the present invention have been described above with reference to the drawings, the present invention is not limited to the illustrated embodiments. Various modifications and variations can be added to the illustrated embodiment within the same range as or equivalent to the present invention. For example, a part of the configuration may be extracted from the above-described one embodiment, another part of the configuration may be extracted from the other embodiment described above, and the extracted configurations may be combined.

The present invention is advantageously used in electric vehicles and hybrid vehicles.

10 in-wheel motor drive device, 11 wheel hub bearing part,
21 motor part, 28, 48, 51, 52 lower arm,
31 speed reducer, 40 strut suspension device,
41 dust boot, 42 damper outer cylinder, 43 damper upper end,
44,46 damper, 45 torsion bar spring,
45b, 45c one end, 45d central region,
45e the other end, 50 double wishbone type suspension device,
53 upper arm, 60,65 carrier member,
67 tie rods, 71 sub-frame (vehicle side member),
72 mount member, 73 main frame,
74 upper mount, 75 power line, 76 clamp member,
77 wheel house, 78 rubber bush, T tire,
W road wheel.

Claims (5)

A suspension arm whose base end is connected to the vehicle body side member, whose free end is connected to an in-wheel motor drive device, and which is vertically swingable about an axis passing through the base end;
A torsion bar spring having one end fixed to the suspension arm and the other end fixed to the vehicle body member;
The suspension structure for an in-wheel motor drive device, wherein the torsion bar spring is twisted and deformed between the one end and the other end as the suspension arm swings. The suspension arm has a plurality of base ends,
The suspension structure for an in-wheel motor drive device according to claim 1, wherein the one end of the torsion bar spring is fixed to each of the plurality of base ends. The one end of the torsion bar spring and the base end of the suspension arm are arranged in front of the free end of the vehicle.
The suspension structure for an in-wheel motor drive device according to claim 1, wherein the other end portion of the torsion bar spring is disposed rearward of the vehicle with respect to the free end. An upper end connected to the vehicle body-side member and a lower end connected to the in-wheel motor drive device;
The suspension structure for an in-wheel motor drive device according to claim 1, wherein the suspension arm is disposed below the damper. The suspension arm is an upper arm connected to an upper portion of the in-wheel motor drive device,
The suspension structure for an in-wheel motor drive device according to claim 1, further comprising a lower arm disposed below the upper arm and connected to a lower portion of the in-wheel motor drive device.

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