JP2005119548A - Suspension device of electric vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a suspension device of an electric vehicle capable of easily achieving an adequate suspension function of a wheel-in motor type driving wheel by sharing a part of the suspension function by motor drive control. <P>SOLUTION: A motor is disposed in a wheel of a driving wheel in a suspension device of a wheel-in motor type electric vehicle. A suspension arm is provided as a suspension member of the driving wheel with one end of the arm fixed to a motor case subjected to the driving reaction force of the motor, and the other end of the arm supported in a rocking manner with respect to a vehicle body. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a suspension device for a wheel-in-motor type electric vehicle in which a motor is disposed in a wheel of a drive wheel.

Conventionally, a wheel-in-motor type electric vehicle in which a motor is disposed in a wheel of a drive wheel is known (see, for example, Patent Document 1).
Japanese Patent Laid-Open No. 10-295004 (FIG. 2)

  However, the suspension function of a conventional wheel-in motor type electric vehicle is intended to be optimized only by a stabilizer or a suspension device that is applied to an engine vehicle, regardless of motor drive control. In the case of the wheel-in motor type, the unsprung weight increases. Therefore, even if it is attempted to optimize only with a stabilizer or suspension device as applied to an engine vehicle, the suspension device is caused by a large unsprung inertia force. As a result, there is a problem that the operation effect on the device and the like is large and the optimization is accompanied by a considerable difficulty.

  The present invention has been made paying attention to the above problem, and by appropriately allocating a part of the suspension function by motor drive control, it is possible to easily achieve optimization of the suspension function of the wheel-in motor type drive wheel. An object is to provide a suspension device for an electric vehicle.

  In order to achieve the above object, according to the present invention, in a suspension apparatus for a wheel-in-motor type electric vehicle in which a motor is disposed in a wheel of a driving wheel, a motor that receives a driving reaction force of the motor as a suspension member of the driving wheel. A suspension arm is provided in which one end of the arm is fixed to the case and the other end of the arm is swingably supported with respect to the vehicle body.

  Here, the “motor drive reaction force” refers to the stator reaction force against the rotor rotational force in the case of a motor that does not have a speed reducer, and in the case of a motor with a speed reducer, the speed is reduced to the stator reaction force against the rotor rotational force. The reaction force with mechanical reaction force added.

  Therefore, in the electric vehicle suspension apparatus of the present invention, for example, when the suspension arm extends in the vehicle longitudinal direction, the motor driving reaction force received at the fixed end to the motor case by controlling the motor driving force. Suspension vertical force is generated according to the size of the wheel, and this suspension vertical force is used for stroke vibration reduction, roll reduction, etc., and part of the suspension function is shared by motor drive control, so wheel-in motor type drive is easy Optimization of the suspension function of the wheel can be achieved.

  Hereinafter, the best mode for realizing a suspension device for an electric vehicle of the present invention will be described based on Examples 1 to 3 shown in the drawings.

First, the configuration will be described.
1 is an overall system diagram showing a suspension device for an electric vehicle according to a first embodiment, FIG. 2 is a cross-sectional view showing a suspension device for one rear wheel of the first embodiment, and FIG. 3 is a suspension device for an electric vehicle according to the first embodiment. It is a control block diagram which shows the suspension controller in.

  As shown in FIG. 1, the rear wheel suspension device of the first embodiment includes a rear tire 1, a rear wheel 2, a motor 3 with a speed reducer, a brake device 4, an axle member 5, a vehicle body side member 6, a strut 7, a parallel link 8, A suspension arm 9 is provided.

  As shown in FIG. 2, the rear wheel 2 is a wheel-in-motor type in which a rear tire 1 is mounted at a wheel outer peripheral position and a motor 3 with a speed reducer and a brake device 4 are disposed at the wheel inner peripheral position.

  In the motor 3 with a speed reducer, a rotor 3c having a motor shaft 3b is disposed in a motor case 3a, a stator 3d having a coil wound around the inner surface of the motor case 3a is fixed, and the rotor 3c and the stator 3d have a slight clearance. It is arrange | positioned coaxially through. The reduction gear is a single planetary gear type reduction gear. The sun gear 3e is connected to the motor shaft 3b, the ring gear 3f is fixed to the motor case 3a, and the pinion carrier 3g that supports the pinion is connected to the wheel drive shaft 3h. The That is, by adopting a ring gear fixed, sun gear input, and carrier output structure, the reduction ratio based on the gear ratio between the sun gear 3e and the ring gear 3f is obtained while the motor shaft 3b and the wheel drive shaft 3h are coaxially arranged. .

  The brake device 4 is formed integrally with a brake disc 4a fixed to the rear wheel 2, a brake pad 4b that sandwiches the outer peripheral position of the brake disc 4a, and the motor case 3a, and applies braking force by hydraulic pressure. And a brake caliper 4c to be obtained.

  As shown in FIG. 2, the axle member 5 is an axle member that is supported on the outer peripheral position of the motor case 3a through a ball bearing or the like so as to be relatively rotatable. Between the axle member 5 and the vehicle body side member 6, a strut 7 for supporting a force acting in the vehicle vertical direction and a parallel link 8 for supporting a force acting in the vehicle left-right direction are interposed. .

  The strut 7 is inclined and arranged in the vehicle vertical direction so that the upper end is slightly inclined toward the vehicle center side with respect to the lower end. The strut 7 is fixed to a shock absorber 7a having a lower end supported by the axle member 5 via a rubber bush and an upper end supported by the vehicle body side member 6 via the rubber bush, and a piston rod of the shock absorber 7a. Between the upper spring seat 7b and the lower spring seat 7c fixed to the cylinder case, there is a coil spring 7d interposed concentrically with the shock absorber 7a.

  The parallel link 8 is arranged in parallel in the left-right direction of the vehicle between the axle member 5 and the vehicle body side member 6, and both ends of the parallel link 8 provide rubber bushes for the axle member 5 and the vehicle body side member 6. Supported through.

  The suspension arm 9 is a suspension member that supports a force acting in the vehicle front-rear direction of the rear tire 1 that is a drive wheel. The suspension arm 9 extending in the vehicle front-rear direction includes the speed reducer as shown in FIG. One end of the arm is fixed to a motor case 3 a that receives the driving reaction force of the motor 3, and the other end of the arm is supported to be swingable with respect to the vehicle body side member 6 via a rubber bush 10.

  The suspension arm 9 generates a suspension vertical force that extends the strut 7 when the motor driving force is increased, and generates a suspension vertical force when the motor driving force is decreased, according to the magnitude of the motor driving reaction force received at the fixed end to the motor case 3a. It is set in an arrangement (see FIG. 1) that is substantially parallel to the road surface in a side view so as to generate a suspension vertical force that shrinks.

  As shown in FIG. 1, the control system of the rear wheel suspension device of the first embodiment includes an accelerator operation amount sensor 11, a motor drive controller 12, a vehicle height sensor 13, and a suspension controller 14 (damping control means).

  The motor drive controller 12 receives the accelerator operation amount information from the accelerator operation amount sensor 11, calculates a drive torque corresponding to the accelerator operation amount that represents a driver's drive torque request, and outputs a drive torque signal to the suspension controller 14. Output to.

  The suspension controller 14 is a means for controlling the motor driving force so as to control the motor driving force so as to suppress the suspension vertical movement with respect to the suspension vertical movement whose suspension stroke speed is equal to or lower than the limit speed.

  As shown in FIG. 3, the suspension controller 14 includes a first limiter 14a, a differentiator 14b (suspension stroke speed detecting means), a bandpass filter 14c, a second limiter 14d, an adder 14e, and a third limiter 14f. .

  The first limiter 14a sets an upper limit value and a lower limit value for the value of the vehicle height sensor signal from the vehicle height sensor 13, and generates a vehicle height signal limit value.

  The differentiator 14b calculates the suspension stroke speed, which is the change speed of the vehicle height, by differentiating the vehicle height signal limit value from the first limiter 14a with time.

  The band pass filter 14c removes the high frequency band component and the low frequency band component of the suspension stroke speed calculated by the differentiator 14b, and generates a suspension stroke speed filter value.

  The second limiter 14d generates a suspension control torque signal in accordance with a suspension stroke speed limit value obtained by setting an upper limit value and a lower limit value for the suspension stroke speed filter value from the bandpass filter 14c.

  The adder 14e adds the suspension control torque signal from the second limiter 14d and the drive torque signal from the motor drive controller 12.

  The third limiter 14f generates a target torque signal by setting an upper limit value and a lower limit value to the torque signal added by the adder 14e, and outputs the target torque signal to the motor 3 with a speed reducer.

  Next, the operation will be described.

[Anti-dive action during acceleration]
At the time of starting or intermediate acceleration, the driving force of the motor 3 with a speed reducer increases according to the accelerator depressing operation, so that an increase in motor driving torque acts as a vertical force that contracts the strut 7, and the vehicle body on the rear wheel side sinks. The rear dive phenomenon is going to occur.

  However, when the motor driving torque is increased, the motor driving reaction force obtained by adding the reduction gear reaction force to the stator reaction force is also increased. As shown in FIG. 6 acts on the upper side of the vehicle and becomes a force for extending the strut 7 by the reaction force from the vehicle body side member 6.

  Therefore, at the time of starting or during intermediate acceleration, the force that contracts the strut 7 (rear dive force) due to the increase in motor drive torque is caused by the force that extends the strut 7 (anti-dive force) due to the increase in motor drive reaction force. This cancels out and prevents the rear dive phenomenon in which the rear wheel body sinks.

  Further, when the anti-dive force due to the motor drive reaction force is smaller than the rear dive force and the vehicle height is lowered due to the rear wheel body sinking, the suspension controller 14 causes the suspension control torque corresponding to the suspension stroke speed to be obtained. As a result, the anti-dive force is further increased, and as a result, the rear dive phenomenon in which the rear wheel body sinks is surely prevented.

[Stroke vibration damping action]
A stroke vibration damping action when minute vibrations that cannot be responded by the shock absorber 7a when traveling on an uneven road surface or the like is input to the rear tire 1 will be described with reference to an uneven road traveling action diagram shown in FIG.

  First, when the rear tire 1 of the flat road surface shown in FIG. 4A shifts to the state where the rear tire 1 rides on the road convex portion of FIG. 4B, the suspension stroke speed is generated so that the strut 7 is contracted. . If a suspension control torque signal with a negative value is calculated based on the suspension stroke speed and a target torque signal obtained by adding the suspension control torque signal and the drive torque signal from the motor drive controller 12 is output, the motor drive force is reduced. Along with this, the motor drive reaction force also decreases, and a force for contracting the struts 7 (= lowering reaction force of the rear tire 1) is generated. As a result, it is possible to suppress the vehicle body from being lifted by the protrusion of the rear tire 1.

  When the rear tire 1 moves from the state in which the rear tire 1 rides on the road surface convex portion in FIG. 4 (b) to the state in which the rear tire 1 descends to the flat road surface in FIG. 4 (c), the suspension stroke speed is generated so that the strut 7 is extended. If a suspension control torque signal with a positive value is calculated based on the suspension stroke speed and a target torque signal obtained by adding the suspension control torque signal and the drive torque signal from the motor drive controller 12 is output, the motor drive force increases. Along with this, the motor driving reaction force also increases, and a force to stretch the strut 7 (= the rising reaction force of the rear tire 1) is generated. As a result, the vehicle body can be prevented from sinking due to the descent from the convex portion of the rear tire 1.

  Therefore, in the first embodiment, the suspension arm 9 has a long support span and cannot absorb large vibrations. However, vibrations caused by small steps and unevenness on the general road can be actively reduced by increasing / decreasing the motor driving force with high response. It is possible to travel without changing the position of the vehicle body side member 6 when traveling on an uneven road.

Next, the effect will be described.
In the suspension device for an electric vehicle according to the first embodiment, the following effects can be obtained.

  (1) In a suspension apparatus for a wheel-in-motor type electric vehicle in which a motor is disposed in a wheel of a driving wheel, one end of an arm is fixed to a motor case that receives a driving reaction force of the motor as a suspension member of the driving wheel. Since the suspension arm that supports the other end of the arm so as to be swingable with respect to the vehicle body is provided, the suspension function of the wheel-in motor type drive wheel can be easily optimized by sharing a part of the suspension function by the motor drive control. Can be achieved. In addition, since the motor case can be molded integrally with the suspension arm, the number of parts can be reduced.

  (2) The suspension arm is arranged in the vehicle longitudinal direction so that the suspension vertical force can be generated according to the magnitude of the motor drive reaction force received at the fixed end to the motor case. Force can be transmitted in the vertical movement direction of the vehicle body.

  (3) The suspension arm is arranged and set so that the rear end of the arm is fixed to a motor case of a wheel-in motor provided on the rear wheel and the front end of the arm is swingably supported by the vehicle body. It is possible to obtain an anti-skid dive effect that prevents the rear body of the vehicle from sinking when the vehicle starts to increase or during intermediate acceleration.

  (4) a suspension stroke speed detecting means for detecting a suspension stroke speed, a suspension controller 14 for controlling the motor driving force so as to suppress the vertical movement of the suspension according to a speed signal from the suspension stroke speed detecting means, Therefore, the micro stroke vibration can be damped by the motor drive force control with high response to the micro stroke vibration which cannot be followed by the shock absorber 7a.

  (5) Since the suspension controller 14 controls the motor driving force with respect to the vertical movement of the suspension whose suspension stroke speed is lower than the limit speed, the motor driving force is changed with respect to the vibration that can be damped by the response of the shock absorber 7a. It is possible to ensure traveling with stable driving performance without any problems.

  The second embodiment is an example in which the anti-roll control that exhibits the stabilizer function at the time of turning when the vehicle body roll is generated is added to the damping control of the minute stroke vibration that assists the shock absorber function of the first embodiment.

  That is, as shown in FIG. 5, lateral acceleration information from the lateral acceleration sensor 15 is added as input information to the suspension controller 14 (anti-roll control means), and the suspension controller 14 is detected when a vehicle body roll occurs. The motor driving force of the motors 3 and 3 with speed reducers provided on the left and right rear wheels so as to determine whether the outer wheel is a turning outer wheel or the inner turning wheel, and to extend the outer turning wheel side and to reduce the turning inner wheel side. As a means to control. Since other configurations are the same as those in the first embodiment, the description thereof is omitted.

  Next, the operation will be described.

[Damping control & anti-roll control operation]
FIG. 6 is a flowchart showing the flow of the damping control & anti-roll control operation executed by the suspension controller 14 of the second embodiment, and each step will be described below.

  In step S1, the vehicle height sensor signal from the vehicle height sensor 13, the drive torque signal from the motor drive controller 12, and the lateral acceleration sensor signal from the lateral acceleration sensor 15 are read, and the process proceeds to step S2.

  In step S2, it is determined whether the lateral acceleration absolute value | Yg | of the lateral acceleration Yg obtained based on the lateral acceleration sensor signal from the lateral acceleration sensor 15 is equal to or smaller than the turning determination threshold value Ygo. Shifts to step S3, and if NO, shifts to step S4.

  In step S3, the minute stroke vibration described in the first embodiment is suppressed based on the determination in step S2 that | Yg | ≦ Ygo, that is, the determination that the vehicle is in a substantially straight traveling state without occurrence of a body roll. Execute damping control and shift to return.

  In step S4, the lateral acceleration sensor signal from the lateral acceleration sensor 15 is determined based on the determination that | Yg |> Ygo is satisfied in step S2, that is, when turning or lane change occurs. The turning direction is discriminated based on the direction in which the turning occurs, and the turning outer wheel and the turning inner wheel are determined by turning direction discrimination. If it is a turning outer wheel, the process proceeds to step S5, and if it is a turning inner wheel, the process proceeds to step S7.

  In step S5, the increased torque on the turning outer wheel side is calculated according to the lateral acceleration absolute value | Yg |, and the process proceeds to step S6.

  In step S6, the target torque is calculated from the sum of the motor drive torque based on the drive torque signal from the motor drive controller 12 and the increased torque calculated in step S5, and is output to the motor 3 with a speed reducer as the target torque signal. Move to return.

  In step S7, a decrease torque on the turning inner wheel side is calculated according to the lateral acceleration absolute value | Yg |, and the process proceeds to step S8.

  In step S8, the target torque is calculated from the difference between the motor drive torque based on the drive torque signal from the motor drive controller 12 and the reduced torque calculated in step S7, and is output to the motor 3 with a speed reducer as the target torque signal. Move to return.

[Anti-roll control action]
For example, the anti-roll control action at the time of turning in Example 2 will be described with reference to FIG. First, when turning, the center of gravity of the vehicle moves to the turning outer wheel side, which increases the load on the turning outer wheel side, reduces the load on the turning inner wheel side, sinks the vehicle body on the turning outer wheel side, and lifts the vehicle body on the turning inner wheel side. The body roll is about to occur.

  On the other hand, in the second embodiment, when the lateral acceleration absolute value | Yg | exceeds the turning determination threshold value Ygo, on the turning outer wheel side, step S1 → step S2 → step S4 → step S5 in the flowchart of FIG. → The flow proceeds to step S6. In step S6, a command for obtaining the sum of the motor driving torque and the increased torque calculated in accordance with the lateral acceleration absolute value | Yg | is output to the motor 3 with a speed reducer. The driving torque of the motor 3 with a speed reducer increases.

  On the other hand, on the turning inner wheel side, the flow proceeds from step S1 to step S2 to step S4 to step S7 to step S8 in the flowchart of FIG. 6. In step S8, the motor driving torque and the lateral acceleration absolute value | Yg | A command for obtaining a torque that is the difference from the calculated decrease torque is output to the motor 3 with a speed reducer, and the drive torque of the motor 3 with the speed reducer is reduced.

  On the turning outer wheel side, the motor driving torque increases, so that the suspension driving force is generated by the motor driving reaction force, and the vehicle body that is about to sink is lifted. On the turning inner wheel side, the motor driving torque is reduced. Thus, an anti-roll characteristic can be obtained in which a suspension downward force is generated by the motor driving reaction force, pulling back the vehicle body to be lifted, and suppressing the vehicle body roll.

Next, the effect will be described.
In the electric vehicle suspension apparatus of the second embodiment, the following effects can be obtained in addition to the effects of the first embodiment.

  (6) The suspension arm 9 is provided on each of the left and right drive wheels, and at the time of turning generated by the body roll, the suspension controller 14 extends the outer wheel side suspension by controlling the motor driving force provided at least on the turning outer wheel side. Therefore, an anti-skirol effect can be produced during turning.

  (7) The suspension controller 14 determines whether the outer wheel is a turning outer wheel or a turning inner wheel based on the direction of occurrence of the detected lateral acceleration Yg, and controls the motor driving force so as to extend the turning outer wheel side and contract the turning inner wheel side. In some cases, the anti-roll effect can be exerted to a high degree, and the idling of the inner ring is suppressed, and the driving force limit of the tire can be used effectively.

  The third embodiment is an example in which a suspension arm for controlling the suspension vertical force is added to an existing suspension device, and the damping force is increased with respect to increase / decrease in motor driving torque.

  That is, as shown in FIG. 8, the first suspension arm 19 arranged and set so as to generate a suspension vertical force according to the magnitude of the motor driving reaction force received at the fixed end to the motor case 3a, and the first suspension arm 19 In addition to the suspension arm 19, there is provided a second suspension arm 29 that extends in the vehicle front-rear direction, with one end of the arm fixed to the axle member 5 and the other end of the arm swingably supported with respect to the vehicle body. The support span L1 of the arm 19 is set shorter than the support span L2 of the second suspension arm 29. An intermediate joint 19a is provided at the intermediate position of the first suspension arm 19 to adjust the effect of the vertical movement effect associated with the increase / decrease in the motor drive reaction force. Since other configurations are the same as those in the first embodiment, the description thereof is omitted.

Next, the operation will be described.
In the third embodiment, the force in the vehicle upper limit direction is supported by the strut 7, the force in the vehicle left-right direction is supported by the parallel link 8, and the force applied in the vehicle front-rear direction is supported by the second suspension arm 29. The direction force is basically supported by three suspension members.

  The first suspension arm 19 obtains the force for extending the strut 7 due to the increase in the motor drive reaction force and the force for contracting the strut 7 due to the decrease in the motor drive reaction force. In addition, the suspension vertical force corresponding to the magnitude of the motor drive reaction force (torque) is obtained by the motor drive reaction force / support span. The shorter the support span, the greater the suspension vertical force becomes. In this case, by setting the support span L1 of the first suspension arm 19 to be shorter than the support span L2 of the second suspension arm 29, when applied to a rear wheel suspension device, the anti-dive effect at the time of start or intermediate acceleration Is larger than in the first and second embodiments. That is, the force for lifting the vehicle body is increased, which is advantageous for a heavy vehicle.

  Further, since the first suspension arm 19 of the third embodiment is provided with the intermediate joint 19a, the intermediate joint 19a is disposed below the line connecting the motor center point and the vehicle body support point as shown in FIG. Thus, the layout freedom of the suspension is not constrained. In addition, for example, when the intermediate joint 19a is disposed at the position of the intermediate joint 19a ′ indicated by the dotted line, even if the motor drive reaction force increases or decreases, The effect of the vertical movement effect can be adjusted by setting the position of the intermediate joint 19a so that the vertical movement hardly occurs. Since other operations are the same as those in the first embodiment, description thereof is omitted.

Next, the effect will be described.
In the electric vehicle suspension apparatus of the third embodiment, the following effects can be obtained in addition to the effects of the first and second embodiments.

  (8) The suspension arm is a first suspension arm 19 arranged and set so as to generate a suspension vertical force according to the magnitude of the motor driving reaction force received at the fixed end to the motor case 3a. In addition to the suspension arm 19, there is provided a second suspension arm 29 that extends in the vehicle front-rear direction, with one end of the arm fixed to the axle member 5 and the other end of the arm swingably supported with respect to the vehicle body. Since the support span L1 of the arm 19 is set to be shorter than the support span L2 of the second suspension arm 29, it is possible to ensure a large vertical force with respect to increase / decrease in motor drive torque.

  As mentioned above, although the suspension apparatus of the electric vehicle of this invention has been demonstrated based on Example 1-3, it is not restricted to these Examples about a concrete structure, Each claim of a claim Design changes and additions are permitted without departing from the spirit of the invention according to the paragraph.

  The suspension system for an electric vehicle according to the present invention employs a wheel-in motor not only for a rear-wheel drive vehicle in which a wheel-in motor is applied to the left and right rear wheels but also to a front-wheel drive vehicle in which a wheel-in motor is applied to the left and right front wheels and four wheels. It can also be applied to four-wheel drive vehicles.

1 is an overall system diagram illustrating a suspension device for an electric vehicle according to a first embodiment. 1 is a cross-sectional view showing a suspension device for one rear wheel in Embodiment 1. FIG. FIG. 3 is a control block diagram illustrating a suspension controller in the suspension device for the electric vehicle according to the first embodiment. It is action explanatory drawing at the time of uneven road driving | running | working in the suspension apparatus of the electric vehicle of Example 1. FIG. It is a whole system figure which shows the suspension apparatus of the electric vehicle of Example 2. FIG. 10 is a flowchart showing a flow of a damping control & anti-roll control operation executed by the suspension controller of the second embodiment. FIG. 10 is an explanatory diagram of an anti-roll action in Example 2. FIG. 6 is a configuration diagram illustrating a suspension device for an electric vehicle according to a third embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Rear tire 2 Rear wheel 3 Motor with reduction gear 4 Brake device 5 Axle member 6 Car body side member 7 Strut 8 Parallel link 9 Suspension arm 10 Rubber bush 11 Accelerator operation amount sensor 12 Motor drive controller 13 Vehicle height sensor 14 Suspension controller (damping control) Means, anti-roll control means)
15 Lateral acceleration sensor 19 First suspension arm 29 Second suspension arm

Claims (8)

In a suspension device for a wheel-in-motor type electric vehicle in which a motor is arranged in a wheel of a driving wheel,
As the suspension member for the driving wheel, a suspension arm is provided in which one end of an arm is fixed to a motor case that receives a driving reaction force of the motor, and the other end of the arm is swingably supported with respect to the vehicle body. Electric vehicle suspension system. In the electric vehicle suspension device according to claim 1,
The suspension device for an electric vehicle according to claim 1, wherein the suspension arm is arranged in the vehicle front-rear direction so as to generate a suspension vertical force corresponding to a magnitude of a motor driving reaction force received at a fixed end to the motor case. The suspension device for an electric vehicle according to claim 2,
The suspension arm has an arm rear end fixed to a motor case of a wheel-in motor provided on a rear wheel, and the arm front end is supported by a vehicle body so as to be swingable. Suspension device. The suspension device for an electric vehicle according to any one of claims 1 to 3,
Suspension stroke speed detecting means for detecting the suspension stroke speed;
Damping control means for controlling the motor driving force so as to suppress the vertical movement of the suspension according to the speed signal from the suspension stroke speed detection means;
A suspension device for an electric vehicle, comprising: In the suspension device of the electric vehicle according to claim 4,
The suspension apparatus for an electric vehicle, wherein the damping control means controls a motor driving force with respect to a vertical movement of the suspension whose suspension stroke speed is equal to or less than a limit speed. The suspension device for an electric vehicle according to any one of claims 1 to 3,
The suspension arm is provided on each of the left and right drive wheels,
An electric vehicle suspension apparatus comprising anti-roll control means for extending a suspension on an outer wheel side by controlling a motor driving force provided at least on a turning outer wheel side when the vehicle body roll is generated. In the electric vehicle suspension apparatus according to claim 6,
The anti-roll control means determines whether the outer wheel is a turning outer wheel or a turning inner wheel based on the detected direction of lateral acceleration, and controls the motor driving force so that the outer turning wheel side is extended and the turning inner wheel side is shortened. Automobile suspension device. In the electric vehicle suspension device according to claim 1,
The suspension arm is a first suspension arm arranged and set so as to generate a suspension vertical force according to the magnitude of the motor drive reaction force received at a fixed end to the motor case,
In addition to the first suspension arm, there is provided a second suspension arm extending in the vehicle front-rear direction, in which one end of the arm is fixed to the axle member and the other end of the arm is swingably supported with respect to the vehicle body, and the first suspension A suspension device for an electric vehicle, wherein a support span of the arm is set shorter than a support span of the second suspension arm.

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