JP4306459B2 - Wheel support device - Google Patents

Description

  The present invention relates to a wheel support device, and more particularly to a wheel support device that can cancel unsprung vibration.

As a conventional in-wheel motor drive system, a hollow motor supported by a motor suspension is known (Non-Patent Document 1). The hollow motor is connected to the wheel of the wheel and rotates the wheel. The motor suspension includes a spring and a damper. The hollow motor is supported by the spring and the damper so as to vibrate in the vertical direction of the vehicle, and is separated from the unsprung weight. The wheel is supported by the vehicle by the suspension arm. In this in-wheel motor drive system, when a wheel vibrates, the hollow motor receives the vibration of the wheel through the wheel, and vibrates in the vertical direction of the vehicle so as to cancel out the unsprung vibration by the spring and the damper.
Japanese Patent Laid-Open No. 11-170831 JP 7-81430 A Go Nagaya, Yasunori Wakao, Akihiko Abe, “Development of Dynamic Damper-type In-wheel Motor”, Japan Society for Automotive Engineers, November 26, 2002, Preprint of Scientific Lecture No. 83-02, p9-12

  However, in the conventional in-wheel motor drive system, since the hollow motor is supported by the spring and the damper so as to vibrate in the vertical direction of the vehicle, the number of components for vibrating the hollow motor in the vertical direction of the vehicle is large. There is a problem of becoming.

  Therefore, the present invention has been made to solve such a problem, and an object of the present invention is to provide a wheel support device capable of canceling unsprung vibration with a small number of parts.

  According to this invention, the wheel support device includes a suspension arm, a rotation support member, and an elastic body. The suspension arm is fixed to the vehicle body so that one end of the suspension arm can rotate in the vertical direction of the vehicle body. The rotation support member is connected to the suspension arm and rotatably supports the wheel of the wheel. The elastic body has a substantially plate-like shape that supports an in-wheel motor provided in the wheel so as to vibrate in the vertical direction of the vehicle body and the wheel.

  Preferably, the elastic body has one end connected to the rotation support member and the other end connected to the in-wheel motor.

  Preferably, the elastic body is arranged so that the width direction thereof is the front-rear direction of the vehicle body.

  Preferably, the elastic body is connected to a substantially center of gravity position of the in-wheel motor.

  Preferably, the elastic body is a leaf spring.

  Preferably, the elastic body is a leaf spring having a multilayer structure.

  Since the wheel support device according to the present invention includes an elastic body that supports the in-wheel motor so as to vibrate in the vertical direction of the vehicle body, the vibration of the wheel in the vertical direction of the vehicle body is caused by the single elastic body in the vertical direction of the in-wheel motor. Converted into vibration.

  Therefore, according to the present invention, the unsprung vibration can be canceled by reducing the number of components.

  Moreover, in the wheel support device according to the present invention, the elastic body is arranged such that the width direction thereof is the front-rear direction of the vehicle body, and therefore the elastic body is less likely to vibrate in the front-rear direction of the vehicle body. As a result, the elastic body opposes the rotational force of the in-wheel motor itself generated by the rotation of the wheel.

  Therefore, according to this invention, rotation of the in-wheel motor itself by rotation of a wheel can be suppressed.

  Furthermore, in the wheel support device according to the present invention, the elastic body is connected near the center of gravity of the in-wheel motor.

  Therefore, according to this invention, an in-wheel motor can be supported stably.

  Furthermore, in the wheel support device according to the present invention, since the elastic body is a leaf spring having a multilayer structure, the vibration of the wheel in the vertical direction of the vehicle body is delayed in phase and the in-wheel in the vertical direction of the vehicle body is delayed. It is converted into motor vibration.

  Therefore, according to the present invention, the vibration of the wheel can be sufficiently damped.

  Embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and description thereof will not be repeated.

  FIG. 1 is a schematic cross-sectional view of a wheel support device according to an embodiment of the present invention and an electric wheel supported thereby. Referring to FIG. 1, electric wheel 100 includes a wheel disc 10, a wheel hub 20, a constant velocity joint 30, a brake rotor 40, a brake caliper 50, an in-wheel motor IWM, and a tire 250.

  The in-wheel motor IWM has a case 60 and a shaft 110. In-wheel motor IWM includes a motor, a planetary gear, an oil pump, and an oil passage. The motor, the planetary gear, the oil pump, and the oil passage are not shown in FIG. 1 because they are housed in the case 60.

  Wheel support device 200 includes ball joints 160, 170, knuckle 180, elastic body 190, upper arm 210, lower arm 220, and shock absorber 230.

  The wheel disc 10 has a substantially cup shape, and includes a disc portion 10A and a rim portion 10B. The wheel disc 10 may house the wheel hub 20, the brake rotor 40, the brake caliper 50, and the in-wheel motor IWM. The wheel disc 10 is coupled to the wheel hub 20 by fastening the disc portion 10A to the wheel hub 20 with screws 1 and 2. The wheel hub 20 incorporates a constant velocity joint 30 and is coupled to the shaft 110 of the in-wheel motor IWM via the built-in constant velocity joint 30. The wheel hub 20 is rotatably supported by the knuckle 180 by the hub bearings 11 and 12.

  The constant velocity joint 30 includes an inner 31 and a ball 32. The inner 31 is fitted to the shaft 110. The ball 32 meshes with the groove of the wheel hub 20 provided in the rotation axis direction of the shaft 110 and the groove of the inner 31, and rotates the wheel hub 20 as the shaft 110 rotates. Further, the ball 32 is movable in the direction of the rotation axis of the shaft 110 along grooves provided in the wheel hub 20 and the inner 31.

  The brake rotor 40 is arranged so that the inner peripheral end is fixed to the outer peripheral end of the wheel hub 20 by screws 3 and 4 and the outer peripheral end passes through the brake caliper 50. The brake caliper 50 is fixed to the knuckle 180. Brake caliper 50 includes a brake piston 51 and brake pads 52 and 53. The brake pads 52 and 53 sandwich the outer peripheral end of the brake rotor 40.

  When brake oil is supplied from the opening 50A, the brake piston 51 moves to the right side of the page and pushes the brake pad 52 to the right side of the page. When the brake pad 52 is moved to the right side of the drawing by the brake piston 51, the brake pad 53 is moved to the left side of the drawing in response. As a result, the brake pads 52 and 53 sandwich the outer peripheral end of the brake rotor 40 and the electric wheel 100 is braked.

  The case 60 is disposed on the left side of the wheel hub 20 in the drawing. Case 60 accommodates shaft 110 and a motor, a planetary gear, an oil pump, and an oil passage that are not shown.

  The shaft 110 has one end connected to the planetary gear, the other end is splined to the inner 31 of the constant velocity joint 30, and is rotatably supported by a bearing (not shown).

  The motor housed in the case 60 includes a stator core, a stator coil, and a rotor. When a current is passed through the stator coil, the rotor rotates and outputs a predetermined torque. The planetary gear reduces the rotation speed of the motor, increases the torque output from the motor, and transmits the torque to the shaft 110. The shaft 110 rotates the wheel hub 20 and the wheel disc 10 at a predetermined rotational speed via the constant velocity joint 30 by the torque transmitted from the planetary gear. Thus, the in-wheel motor IWM is housed in the wheel disk 10 and rotates the wheel hub 20 and the wheel disk 10 at a predetermined number of rotations with a predetermined torque. Thereby, the electric wheel 100 rotates at a predetermined number of rotations. During the driving of the in-wheel motor IWM, the oil pump built in the in-wheel motor IWM pumps up the oil accumulated in the oil reservoir through the oil passage, and the pumped oil is a stator coil, a planetary gear, a bearing, and the like of the motor. To cool the stator coil and lubricate the planetary gear and the bearing.

  The tire 250 is fixed to the outer edge of the rim portion 10B of the wheel disc 10.

  The knuckle 180 (180a) has one end connected to the ball joint 160 and the other end connected to the wheel hub 20 via the hub bearings 11 and 12. The knuckle 180 (180b) has one end connected to the ball joint 170 and the other end connected to the wheel hub 20 via the hub bearings 11 and 12. Thus, the knuckle 180 (180a, 180b) rotatably supports the wheel hub 20 and the wheel disc 10.

  The elastic body 190 (190a) has one end connected to the knuckle 180 (180a) and the other end connected to the case 60 of the in-wheel motor IWM by the screw 5. The elastic body 190 (190b) has one end connected to the knuckle 180 (180b) and the other end connected to the case 60 of the in-wheel motor IWM by the screw 6.

  The region 7 is a region where the center of gravity position of the in-wheel motor IWM exists. Therefore, in more detail, the elastic bodies 190a and 190b are connected by the screws 5 and 6 near the area 7 where the center of gravity position of the in-wheel motor IWM exists. That is, the elastic body 190 has one end connected to the knuckle 180 and the other end connected to the approximate center of gravity of the in-wheel motor IWM. Accordingly, the elastic body 190 supports the in-wheel motor IWM from the vertical direction DR1 of the vehicle body.

  The upper arm 210 and the lower arm 220 are disposed in the vertical direction DR1 of the vehicle body. The upper arm 210 has one end connected to the ball joint 160 and the other end fixed to the vehicle body so as to be rotatable in the vertical direction DR1 of the vehicle body. The lower arm 220 has one end connected to the ball joint 170 and the other end fixed to the vehicle body so as to be rotatable in the vertical direction DR1 of the vehicle body. Further, the lower arm 220 is connected to the vehicle body via a shock absorber 230. As a result, the electric wheel 100 is suspended from the vehicle body.

  As described above, the upper arm 210 and the lower arm 220 are connected to the knuckle 180 from the vertical direction DR1 of the vehicle body via the ball joints 160 and 170, respectively.

  The upper arm 210 and the lower arm 220 are fixed to the vehicle body so as to be rotatable in the vertical direction DR1 of the vehicle body, and the lower arm 220 is connected to the vehicle body via the shock absorber 230. Functions as a suspension. The upper arm 210 and the lower arm 220 constitute a “suspension arm”.

  FIG. 2 is a perspective view of the elastic body 190 shown in FIG. Referring to FIG. 2, the elastic body 190 is composed of a plurality of iron plates 191 to 19n (n is a natural number). The iron plate 191 includes flat portions 191A and 191B and an inclined portion 191C. The inclined portion 191C is disposed between the two flat portions 191A and 191B and connected to the two flat portions 191A and 191B. Further, the flat portions 191A and 191B form a step in the vertical direction DR1 of the vehicle body, and are provided substantially parallel to two planes arranged at an interval corresponding to the step. Therefore, the iron plate 191 has a bent structure so that a step is formed in the vertical direction DR1 of the vehicle body.

  Each of the iron plates 192 to 19n has the same structure as the iron plate 191. The elastic body 190 has a structure in which a plurality of iron plates 191 to 19n are stacked in the vertical direction DR1 of the vehicle body. Therefore, the elastic body 190 has a structure that is bent so that a step is formed in the vertical direction DR1 of the vehicle body, and has a substantially plate shape. Since the elastic body 190 has a bent structure so that a step is formed in the vertical direction DR1 of the vehicle body, the elastic body 190 functions as a spring having a spring constant k1 in the vertical direction DR1 of the vehicle body. Further, since the elastic body 190 has a substantially plate shape, it functions as a spring having a spring constant k2 larger than the spring constant k1 in the longitudinal direction DR2 of the vehicle body perpendicular to the vertical direction DR1.

  Thus, the elastic body 190 is a leaf spring having a substantially plate shape. The elastic body 190 is a leaf spring having a multilayer structure.

  The elastic body 190 has a width W1 on the flat portion 191A side and a width W2 on the flat portion 191B side. The elastic body 190 (190a) is connected to the case 60 of the in-wheel motor IWM on the flat portion 191A side and connected to the knuckle 180 (180a) on the flat portion 191B side. The elastic body 190 (190b) is connected to the knuckle 180 (180b) on the flat portion 191A side and connected to the case 60 on the flat portion 191B side.

  The widths W1 and W2 may be determined to be substantially equal to each other, or may be determined to be different from each other. When the widths W1 and W2 are determined so as to be different from each other, in the elastic body 190 (190a) coupled to the knuckle 180 (180a), the width W1 is determined to be wider than the width W2, and the knuckle 180 ( In the elastic body 190 (190b) connected to 180b), the width W2 is determined to be wider than the width W1. That is, in the elastic body 190, the widths W1 and W2 are determined so that the width on the flat portion side connected to the case 60 of the in-wheel motor IWM is wider than the width on the flat portion side connected to the knuckle 180. . Accordingly, as described later, the rotation of the in-wheel motor IWM itself due to the rotation of the electric wheel 100 is easily suppressed.

  FIG. 3 is a plan view of the electric wheel 100 and the wheel support device 200 viewed from the direction A shown in FIG. In FIG. 3, the upper arm 210, the lower arm 220, and the shock absorber 230 are omitted.

  Referring to FIG. 3, elastic body 190 is fixed to case 60 of in-wheel motor IWM as described above. In this case, the elastic body 190 is disposed such that the width direction thereof is the front-rear direction DR2 of the vehicle body. Since the electric wheel 100 is rotated by the torque output from the in-wheel motor IWM, the electric wheel 100 tries to rotate in the rotation direction DR4 opposite to the rotation direction DR3 as the electric wheel 100 rotates in the rotation direction DR3. A rotational reaction force is generated in the in-wheel motor IWM.

  However, since the elastic body 190 is arranged so that the width direction thereof is the longitudinal direction DR2 of the vehicle body, the in-wheel motor IWM rotates in the rotational direction DR4 against the rotational reaction force generated in the in-wheel motor IWM. Suppress. In particular, as described above, when the width of the elastic body 190 is determined so that the width of the elastic body 190 on the in-wheel motor IWM side is wider than the width of the elastic body 190 on the knuckle 180 side, the elastic body 190 It is easy to suppress the in-wheel motor IWM from rotating in the rotation direction DR4 against the rotational reaction force generated in the wheel motor IWM. Therefore, the spring constant k2 when the elastic body 190 functions as a spring in the front-rear direction DR2 of the vehicle body, the in-wheel motor IWM rotates in the rotational direction DR4 against the rotational reaction force that the elastic body 190 generates in the in-wheel motor IWM. It is decided to suppress it. That is, the spring constant k2 is determined in consideration of the rotational torque of the electric wheel 100.

  Referring to FIG. 1 again, the elastic body 190 supports the in-wheel motor IWM so as to vibrate in the vertical direction DR1 of the vehicle body. That is, when the motorized wheel 100 receives vibration in the vertical direction DR1 of the vehicle body according to the road surface condition or the like while the vehicle is running, the elastic body 190 receives vibration in the vertical direction DR1 from the wheel disk 10 via the knuckle 180. The in-wheel motor IWM is vibrated in the vertical direction DR1 of the vehicle body by delaying the phase of the received vibration. Therefore, when the elastic body 190 functions as a spring in the vertical direction DR1 of the vehicle body, the spring constant k1 delays the phase of vibration received from the wheel disk 10 via the knuckle 180 and causes the in-wheel motor IWM to move in the vertical direction of the vehicle body. It is determined to cause DR1 to vibrate. That is, the spring constant k1 is determined in consideration of the mass of the in-wheel motor IWM when the in-wheel motor IWM is used as a weight.

  The wheel support device 200 connects the elastic body 190 to the case 60 of the in-wheel motor IWM, and connects the suspension arms (the upper arm 210 and the lower arm 220) to the knuckle 180 by the ball joints 160 and 170. Support the car body.

  That is, the wheel support device 200 rotatably supports the wheel disc 10 and the wheel hub 20 by the upper arm 210, the lower arm 220, and the knuckle 180, and the in-wheel motor IWM by the upper arm 210, the lower arm 220, the knuckle 180, and the elastic body 190. Is supported to be able to vibrate in the vertical direction DR1 of the vehicle body, and the in-wheel motor IWM rotates in a direction opposite to the rotation direction of the electric wheel 100 against the rotational reaction force generated in the in-wheel motor IWM by the rotation of the electric wheel 100. To suppress.

  When the motorized wheel 100 receives vibration in the vertical direction DR1 of the vehicle body according to the road surface condition or the like while the vehicle is running, the elastic body 190 functions as a spring in the vertical direction DR1 of the vehicle body by the in-wheel motor IWM serving as a damper mass. Then, the in-wheel motor IWM generates the vibration in the vertical direction DR1 in which the phase of the vibration received by the electric wheel 100 is delayed. That is, the elastic body 190 converts the vibration of the electric wheel 100 into the vibration of the in-wheel motor IWM whose phase is delayed. The elastic body 190 causes the in-wheel motor IWM to cancel the vibration received by the electric wheel 100. If it does so, it will become difficult to transmit the vibration of the motor-driven wheel 100 to the vehicle body via the upper arm 210 and the lower arm 220.

  Thereby, the unsprung input from the tire 250 is relieved. That is, vibration that cannot be absorbed by the shock absorber 230 is absorbed. As a result, the ride comfort of the vehicle is improved.

  Further, when the electric wheel 100 rotates in the rotation direction DR3 while the vehicle is traveling, the in-wheel motor IWM tries to rotate in the rotation direction DR4 (see FIG. 3). Then, the elastic body 190 suppresses the rotation of the in-wheel motor IWM caused by the rotation of the electric wheel 100.

  As described above, the elastic body 190 causes the in-wheel motor IWM to vibrate in the vertical direction DR1 of the vehicle body by delaying the phase of the vibration of the electric wheel 100 and to rotate the in-wheel motor IWM caused by the rotation of the electric wheel 100. Suppress.

  In the wheel support device 200, the in-wheel motor IWM is supported by the single elastic body 190 so as to be able to vibrate in the vertical direction DR1 of the vehicle body.

  Further, since the elastic body 190 is connected to the vicinity of the center of gravity of the in-wheel motor IWM (region 7 in FIG. 1), the in-wheel motor IWM can be stably supported.

  Furthermore, since the elastic body 190 is composed of a multilayer leaf spring in which a plurality of iron plates 191 to 19n are laminated, the vibration of the electric wheel 100 in the vertical direction DR1 of the vehicle body can be sufficiently damped.

  In the above description, the elastic body 190 is connected to both the knuckles 180a and 180b. However, the present invention is not limited to this, and the elastic body 190 is connected to one of the knuckles 180a and 180b. It may be. That is, in the present invention, the elastic body 190 only needs to be connected to at least one of the knuckles 180a and 180b.

  The wheel disc 10 and the wheel hub 20 constitute a “wheel”.

  Further, the knuckles 180a and 180b constitute “a pair of knuckles”.

  Further, the knuckle 180 constitutes a “rotation support member” that rotatably supports the wheel (wheel disc 10 and wheel hub 20) of the electric wheel 100.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description of the embodiments but by the scope of claims for patent, and is intended to include meanings equivalent to the scope of claims for patent and all modifications within the scope.

  The present invention is applied to a wheel support device that can cancel the unsprung vibration with a small number of parts.

1 is a schematic cross-sectional view of a wheel support device according to an embodiment of the present invention and an electric wheel supported by the wheel support device. It is a perspective view of the elastic body shown in FIG. It is a top view of the motor-driven wheel and wheel support apparatus seen from the A direction shown in FIG.

Explanation of symbols

  1-6 screw, 7 area, 10 wheel disc, 10A disc portion, 10B rim portion, 11, 12 hub bearing, 20 wheel hub, 30 constant velocity joint, 40 brake rotor, 50 brake caliper, 50A opening, 51 brake piston , 52, 53 Brake pad, 60 Case, 100 Motorized wheel, 110 Shaft, 160, 170 Ball joint, 180, 180a, 180b Knuckle, 190, 190a, 190b Elastic body, 191-19n Iron plate, 191A, 191B Flat part, 191C Inclined part, 200 wheel support device, 210 upper arm, 220 lower arm, 230 shock absorber, 250 tire, IWM in-wheel motor.

Claims (6)

A suspension arm that is fixed to the vehicle body so that one end thereof is rotatable in the vertical direction of the vehicle body;
A rotation support member coupled to the suspension arm and rotatably supporting a wheel of the wheel;
A wheel support device comprising: an in-wheel motor provided in the wheel; and an elastic body having a substantially plate shape that supports the vehicle body and the wheel so as to vibrate in a vertical direction of the vehicle body.   The wheel support device according to claim 1, wherein one end of the elastic body is connected to the rotation support member and the other end is connected to the in-wheel motor.   The wheel support device according to claim 1, wherein the elastic body is disposed such that a width direction thereof is a front-rear direction of the vehicle body.   The wheel support device according to any one of claims 1 to 3, wherein the elastic body is connected to a substantially center of gravity position of the in-wheel motor.   The wheel support device according to any one of claims 1 to 4, wherein the elastic body is a leaf spring.   The wheel support device according to any one of claims 1 to 4, wherein the elastic body is a leaf spring having a multilayer structure.

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