JP2005035490A - Vehicle suspension device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vehicle suspension device, adjusting the ground clearance depending on a state of the running road surface. <P>SOLUTION: This vehicle suspension device determines whether the vehicle is running on a bad road from the amount of electric power applied to a motor functioning as an electromagnetic absorber and the electric power application time (S12). In this vehicle suspension device, when a large amplitude variation in applied current to the motor continues for predetermined time or more, the road is determined to be bad. When the bad road is decided, the ground clearance is increased (S18) to prevent interference of the car body with the road surface. On the other hand, when the road is determined to be good, the stroke position of each wheel is adjusted so that the car body becomes parallel to the road surface. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a vehicle suspension device, and more particularly to a vehicle suspension device capable of detecting the state of a traveling road surface.

There has been proposed a technique for determining whether or not the vehicle is on a rough road such as rough terrain using a vehicle height sensor and adjusting the vehicle height of the air suspension vehicle using a determination result by the vehicle height sensor (for example, (See Patent Document 1). Further, as a vehicle suspension technique, there is one that proposes an electromagnetic absorber provided with a motor and a ball screw (for example, see Patent Document 2).
Japanese Patent Laid-Open No. 11-123919 JP-A-8-197931

  According to the conventional vehicle height adjustment technique disclosed in Patent Document 1, the vehicle height sensor is required to be costly, and the control response of the air spring is not good, so that it takes time to adjust the vehicle height. Even when the vehicle height is adjusted by, for example, a hydropneumatic system other than the air spring, fine adjustment is difficult, and it takes time to reach the desired vehicle height.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a technique capable of detecting the state of a traveling road surface and further realizing vehicle height adjustment with a simple configuration.

  In order to solve the above-described problems, an aspect of the present invention includes an absorber that generates a damping force between a sprung and an unsprung portion of a vehicle using a motor, a power control unit that controls power applied to the motor, and a motor. There is provided a vehicle suspension device comprising: determination means for determining whether or not the vehicle is traveling on a rough road from the amount of electric power applied to the vehicle. The absorber may be configured with a motor and a ball screw. This absorber may function as an electromagnetic shock absorber that generates a damping force between the sprung and unsprung parts of the vehicle using a motor and a ball screw. The electric power applied to the motor may be a current or a voltage. According to the vehicle suspension device of this aspect, the road surface condition can be easily determined by effectively using the amount of electric power applied to the motor in order to adjust the damping force of the absorber.

  The determination means may determine whether or not the vehicle is traveling on a rough road based on the amount of power applied to the motor and the application time of the power. By setting the power application time as a determination target, it is possible to accurately grasp the road surface state.

  In the vehicle suspension device of this aspect, when the determination means determines that the vehicle is traveling on a rough road, the relative displacement amount between the sprung and unsprung portions is adjusted by the motor so as to avoid interference between the vehicle body and the road surface. You may further provide a rough road corresponding | compatible adjustment means. The rough road correspondence adjusting means may adjust the relative displacement amount between the sprung and unsprung portions in a direction to increase the distance between the vehicle body and the road surface. The rough road correspondence adjusting means can appropriately increase the vehicle height during traveling on rough roads.

  The vehicle suspension device of this aspect is a good road that adjusts the relative displacement amount between the sprung and unsprung by the motor so that the vehicle body and the road surface are parallel when the judging means judges that the vehicle is not traveling on a rough road. Corresponding adjustment means may be further provided. The vehicle height can be appropriately adjusted while traveling on a good road by the good road correspondence adjusting means. The good road correspondence adjusting means may adjust the vehicle height according to the vehicle speed.

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to provide the vehicle suspension apparatus which can detect the state of a driving | running | working road surface and implement | achieves vehicle height adjustment by simple structure.

  FIG. 1 shows a configuration of a vehicle 1 according to an embodiment of the present invention. The vehicle 1 includes a vehicle body 2, a wheel 3a that is a left front wheel, a wheel 3b that is a right front wheel, a wheel 3c that is a left rear wheel, and a wheel 3d that is a right rear wheel (hereinafter, collectively referred to as "wheel 3" as appropriate). . The wheel 3 is composed of a wheel and a rubber tire. The vehicle body 2 and the wheel 3 are connected via an electromagnetic suspension provided with an absorber that generates a damping force between the sprung and unsprung portions of the vehicle 1 using a motor. The position of the member supported by the coil spring of the electromagnetic suspension is called “sprung”, and the position of the member not supported by the coil spring is called “unsprung”. That is, the sprung is on the vehicle body 2 side, and the unsprung is on the wheel 3 side. In this example, the wheel 3a is attached to the electromagnetic suspension 4a, the wheel 3b is attached to the electromagnetic suspension 4b, the wheel 3c is attached to the electromagnetic suspension 4c, and the wheel 3d is attached to the electromagnetic suspension 4d. Hereinafter, the electromagnetic suspensions 4a, 4b, 4c, and 4d are collectively referred to as “electromagnetic suspension 4”. Each electromagnetic suspension 4 is independently controlled by an electronic control device (hereinafter, the electronic control device is referred to as “ECU”) 10. The ECU 10 includes a CPU, a RAM, and a ROM.

  The current flowing through the motor of the electromagnetic suspension 4 is detected by a current sensor. A current sensor 5a is provided for the electromagnetic suspension 4a, a current sensor 5b is provided for the electromagnetic suspension 4b, a current sensor 5c is provided for the electromagnetic suspension 4c, and a current sensor 5d is provided for the electromagnetic suspension 4d. The rotational speed of the wheel 3 is detected by a wheel speed sensor. A wheel speed sensor 6a is provided for the wheel 3a, a wheel speed sensor 6b for the wheel 3b, a wheel speed sensor 6c for the wheel 3c, and a wheel speed sensor 6d for the wheel 3d. Hereinafter, the current sensors 5a, 5b, 5c, and 5d are collectively referred to as “current sensor 5”, and the wheel speed sensors 6a, 6b, 6c, and 6d are collectively referred to as “wheel speed sensor 6”. The detection results of each current sensor 5 and each wheel speed sensor 6 are transmitted to the ECU 10. The current detection function by the current sensor 5 may be realized by the ECU 10. The ECU 10 can measure the vehicle speed from the detection result of the wheel speed sensor 6.

  In the vehicle 1 of the present embodiment, a vehicle suspension device in which the electromagnetic suspension 4, the current sensor 5, the wheel speed sensor 6, and the ECU 10 determine the state of the traveling road surface and realize the vehicle height adjustment according to the determined road surface state. Configure. By providing the electromagnetic suspension 4 for each wheel 3, the ECU 10 can independently control the current applied to the motor of each electromagnetic suspension 4 according to the road surface condition. Further, by adopting the electromagnetic suspension 4, it is possible to realize control with excellent responsiveness compared to the case of using an air suspension or a hydraulic shock absorber.

  FIG. 2 shows the configuration of the electromagnetic suspension 4. The electromagnetic suspension 4 includes a motor 20, a coil spring 22, a ball screw 24, a ball screw nut 26, a rod 28, an outer shell 30, bearings 32, 34 and 36, a dust seal 38 and a rotation angle sensor 44. The bearing 32 rotatably supports the ball screw 24 inside the rod 28, and the bearings 34 and 36 support the rod 28 slidably inside the outer shell 30. The dust seal 38 prevents foreign matters such as dust from entering the outer shell 30. The rotation angle sensor 44 detects the rotation amount of the motor 20, and the detection result of the rotation angle sensor 44 is transmitted to the ECU 10. The rotation angle sensor 44 may be provided outside the motor 20 or may be provided inside the motor 20. The electromagnetic suspension 4 is attached to the configuration on the vehicle body 2 side at the first attachment portion 40, and is attached to the configuration on the wheel 3 side at the second attachment portion 46. The coil spring 22 is contracted between the body surface in the vicinity of the first mounting portion 40 and the spring seat 42, and is given a predetermined load in advance.

  The coil spring 22 supports the weight of the sprung portion of the vehicle 1 and prevents vibrations and shocks from the road surface from being transmitted to the vehicle body 2 through the wheels 3. The motor 20 and the ball screw 24 function as a shock absorber, and attenuate the vertical vibration of the vehicle body 2 caused by the coil spring 22. This shock absorber can generate a damping force between the sprung and unsprung parts of the vehicle 1 using the motor 20, and has excellent control response.

  The ball screw 24, the rod 28 and the outer shell 30 are arranged coaxially. The outer shell 30 is internally provided with a ball screw nut 26 having a female screw portion. The ball screw 24 has a male screw portion and is in a state of being screwed into the ball screw nut 26. The motor 20 supports one end of the ball screw 24 by serration so as to be rotatable. When the motor 20 is driven, the ball screw 24 rotates relative to the ball screw nut 26, and the outer shell 30 is pushed downward or lifted upward with respect to the motor 20.

  When the vehicle 1 is traveling on a horizontal good road, the ECU 10 sets the current value applied to the motor 20 of each electromagnetic suspension 4 to a reference current value of, for example, 0A. When the road surface is uneven, the ECU 10 measures the acceleration in the vertical direction of the vehicle body 2 from the detection result by an acceleration sensor (not shown) provided in the vehicle body 2. When the wheel 3 moves up and down, the coil spring 22 expands and contracts due to the relative movement between the rod 28 and the outer shell 30. At this time, when the ball screw 24 rotates relative to the ball screw nut 26, the motor 20 rotates and acts as a generator, and a damping force is generated by the resistance force generated at this time. The current sensor 5 detects a current generated by electromagnetic induction inside the motor 20 and transmits it to the ECU 10. The ECU 10 applies to the motor 20 a current in a direction that suppresses expansion and contraction of the coil spring 22, that is, a current that is opposite to the current generated by electromagnetic induction. ECU10 sets the electric current applied to the motor 20 according to the acceleration of the up-down direction of the vehicle body 2, and adjusts damping force.

  The vehicle suspension apparatus according to the present embodiment uses a shock absorber capable of adjusting the damping force by driving the motor 20 in order to adjust the relative displacement amount between the sprung and unsprung according to the road surface condition. The relative displacement amount between the sprung and unsprung is the stroke neutral position of the shock absorber in a stationary state, and is determined at a position where the spring force by the coil spring 22, the vehicle weight, and the frictional force of the shock absorber are balanced. The ECU 10 can independently change the relative displacement amount between the sprung and unsprung portions of each wheel 3 by controlling the current applied to each motor 20, and raises or lowers the vehicle height at each wheel 3. be able to. Specifically, by applying a set applied current to the motor 20 on a regular basis with reference to the relative displacement amount between the sprung and unsprung when a reference current value of 0 A is applied to the motor 20, The amount of displacement can be offset upward or downward.

  In the vehicle suspension apparatus according to the present embodiment, the ECU 10 functions as a determination unit that determines whether or not the vehicle 1 is traveling on a rough road from the amount of current applied to the motor 20. As described above, when the road surface is uneven, the ECU 10 applies a current in the direction opposite to the current generated by the electromagnetic induction to the motor 20. The ECU 10 determines that the vehicle is traveling on a rough road when the amplitude fluctuation of the current applied to the motor 20 is large and the state continues for a predetermined time or more.

FIG. 3 shows an example of the time variation of the current applied to the motor 20 by the ECU 10. The ECU 10 does not apply current to the motor 20 from time T ₀ to time T ₁ . The ECU 10 applies a current in the forward direction or the reverse direction to the motor 20 from time T ₁ to time T ₃ . In this case, the period from time T ₁ to time T _2, the amplitude variation of the applied current is large, during the time T ₂ to time T _3, the amplitude variation of the applied current is small. The amplitude fluctuation may be defined, for example, as a difference between a current maximum value in the positive direction and a current minimum value in the negative direction during a predetermined time ΔT. The magnitude of the amplitude fluctuation is determined by comparison with a predetermined threshold value. A large amplitude fluctuation means that the road surface is uneven, and a small amplitude fluctuation means that the road surface is small.

When the amplitude fluctuation of the applied current is small, the ECU 10 determines that the vehicle 1 is not traveling on a rough road. Even when the amplitude variation of the applied current is large, the ECU 10 determines that the vehicle 1 is not traveling on a rough road even when the state does not continue for a predetermined time or longer. For example, when the vehicle 1 accidentally rides on a stone rolling on the road surface, the amplitude fluctuation of the current applied to the motor 20 increases momentarily, but when the vehicle 1 passes the stone, it is applied within a short time. The current also decreases or becomes zero. Therefore, the ECU 10 determines that the vehicle 1 is not traveling on a rough road when the state where the amplitude fluctuation is large does not continue for a long time. On the other hand, when the state in which the amplitude fluctuation is large continues for a predetermined time or more, the ECU 10 determines that the vehicle 1 is traveling on a rough road. In the example of FIG. 3, it is determined that the ECU 10 is traveling on a good road from time T ₀ to time T ₁ and from time T ₂ to time T _3, and from time T ₁ to time T _1. It is determined that the vehicle is traveling on a rough road until ₂ .

  FIG. 4 shows a flowchart of the vehicle height adjustment control. In this flowchart, I (FL) is a current command value to the motor corresponding to the wheel 3a which is the left front wheel, I (FR) is a current command value to the motor corresponding to the wheel 3b which is the right front wheel, and I ( RL) indicates a current command value to the motor corresponding to the wheel 3c which is the left rear wheel, and I (RR) indicates a current command value to the motor corresponding to the wheel 3d which is the right rear wheel.

  First, the count coefficient n is set to 0 (S10). Subsequently, during a predetermined time ΔT, it is determined whether or not the difference between the maximum current command value and the minimum current command value for each motor 20 is larger than the threshold value Ia (S12). ΔT may be, for example, about 5 seconds. When the difference between the maximum value and the minimum value of I (FL), I (FR), I (RL), and I (RR) in the period of ΔT, that is, all the amplitude fluctuations are larger than the threshold value Ia (Y in S12) The count coefficient n is incremented by 1 (S14), and it is determined whether or not the incremented n is equal to a predetermined number of repetitions N (S16).

  When n is smaller than N (N in S16), the steps from S12 to S14 are repeated. When the determination step of S12 is repeated N times, n becomes equal to N (Y of S16), and the ECU 10 determines that the vehicle is on a bad road and avoids the interference between the vehicle body 2 and the road surface. The relative displacement amount between the unsprung parts is adjusted by the motor 20. The number of repetitions N may be about 10 times, for example. When ΔT is set to 5 seconds and the determination step of S12 is repeated 10 times, a state in which the amplitude variation is large continues for 50 seconds. The ECU 10 functions as a rough road correspondence adjusting means, and adjusts the relative displacement amount between the sprung and unsprung portions in a direction to increase the distance between the vehicle body 2 and the road surface. That is, the ECU 10 raises the stroke neutral position upward to raise the vehicle height.

  At this time, the ECU 10 independently drives the motor 20 corresponding to each wheel 3 to raise the stroke neutral position. The lifting amounts of all the wheels may be equal, and the lifting amounts of the stroke neutral positions may be determined independently for the four wheels so that the vehicle body 2 is kept parallel to the road surface. Even when the vehicle body 2 vibrates by traveling on a rough road, it is possible to avoid a situation in which the vehicle body 2 and the road surface come into contact with each other by increasing the vehicle height.

  In S12, when any of amplitude fluctuations of I (FL), I (FR), I (RL), and I (RR) is equal to or less than the threshold value Ia (N in S12), the ECU 10 indicates that the vehicle 1 is on a rough road. It is determined that the vehicle is not traveling, that is, the vehicle is traveling on a good road, and the vehicle height adjustment control during traveling on a rough road is terminated.

  When the vehicle 1 is traveling on a good road, the ECU 10 functions as a good road correspondence adjusting means. Hereinafter, for the sake of convenience, the relative displacement amount between the sprung and unsprung, that is, the stroke neutral position of the shock absorber is simply referred to as “wheel stroke position”. 5 and 6, St (FL) is the stroke position of the wheel 3a that is the left front wheel, St (FR) is the stroke position of the wheel 3b that is the right front wheel, and St (RL) is the left rear wheel. A stroke position of a certain wheel 3c, St (RR) indicates a stroke position of the wheel 3d which is the right rear wheel. The stroke position is positive in the direction away from the road surface.

  FIG. 5 shows a flowchart of the vehicle height adjustment control when the vehicle body 2 is tilted in the left-right direction. First, the rotation angle sensor 44 corresponding to each wheel 3 detects the rotation amount of the motor 20 (S30). The detection result of the rotation angle sensor 44 is transmitted to the ECU 10, and the ECU 10 calculates the stroke positions of all the wheels 3 (S32).

  The stroke positions of the front wheels of the wheels 3a and 3b are compared (S34). If the stroke position of the wheel 3b as the right front wheel is higher than the stroke position of the wheel 3a as the left front wheel (Y in S34), the stroke positions of the rear wheels of the wheel 3c and the wheel 3d are compared (S36). If the stroke position of the wheel 3d, which is the right rear wheel, is higher than the stroke position of the wheel 3c, which is the left rear wheel (Y in S36), the ECU 10 determines that the vehicle body 2 is in the leaning posture, and The stroke position is corrected (S38). The front wheel correction amount (ΔF) and the rear wheel correction amount (ΔR) are obtained by the following equations.

ΔF = | St (FR) −St (FL) | / 2
ΔR = | St (RR) −St (RL) | / 2
Since the vehicle body 2 is tilted to the left, the ECU 10 raises the stroke position of the wheel 3a, which is the left front wheel, by ΔF, and lowers the stroke position of the wheel 3b, which is the right front wheel, by ΔF. Correct. Further, the ECU 10 corrects the stroke position of the rear wheel so that the stroke position of the wheel 3c as the left rear wheel is increased by ΔR and the stroke position of the wheel 3d as the right rear wheel is decreased by ΔR. Accordingly, the ECU 10 can adjust the relative displacement amount between the sprung and unsprung so that the vehicle body 2 and the road surface are parallel to each other.

  On the other hand, if the stroke position of the wheel 3b, which is the right front wheel, is not higher than the stroke position of the wheel 3a, which is the left front wheel, by comparing the stroke positions of the front wheels (N in S34), the rear wheels of the wheels 3c and 3d The stroke positions are compared (S40). If the stroke position of the wheel 3c that is the left rear wheel is higher than the stroke position of the wheel 3d that is the right rear wheel (Y in S40), the ECU 10 determines that the vehicle body 2 is in the right-tilting posture, and The stroke position is corrected (S42).

  Since the vehicle body 2 is tilted to the right, the ECU 10 lowers the stroke position of the wheel 3a, which is the left front wheel, by ΔF, and increases the stroke position of the wheel 3b, which is the right front wheel, by ΔF. Correct. Further, the ECU 10 corrects the stroke position of the rear wheel so that the stroke position of the wheel 3c as the left rear wheel is lowered by ΔR and the stroke position of the wheel 3d as the right rear wheel is raised by ΔR. Accordingly, the ECU 10 can adjust the relative displacement amount between the sprung and unsprung so that the vehicle body 2 and the road surface are parallel to each other.

  In S36, when the stroke position of the wheel 3d as the right rear wheel is not higher than the stroke position of the wheel 3c as the left rear wheel (N in S36), the stroke position of the wheel 3c as the left rear wheel is determined in S40. If it is not higher than the stroke position of the wheel 3d that is the right rear wheel (N in S40), the ECU 10 ends the vehicle height adjustment control flow in the left-right direction without correcting the stroke position.

  In the above example, the vehicle height is adjusted so that the stroke position of each wheel is adjusted to the middle position between the stroke positions of the left and right wheels, but the higher stroke position and the lower stroke position are adjusted. Vehicle height adjustment may be performed. When the vehicle speed is low, it may be controlled to increase the vehicle height in order to avoid interference with the road surface. On the other hand, when the vehicle speed is high, it may be controlled to decrease the vehicle height to ensure driving stability. Good. The ECU 10 preferably measures the vehicle speed from the detection result of the wheel speed sensor 6 and adjusts the stroke position of each wheel based on the measured vehicle speed.

  FIG. 6 shows a flowchart of the vehicle height adjustment control when the vehicle body 2 is tilted in the front-rear direction. First, the rotation angle sensor 44 corresponding to each wheel 3 detects the rotation amount of the motor 20 (S50). The detection result of the rotation angle sensor 44 is transmitted to the ECU 10, and the ECU 10 calculates the stroke positions of all the wheels 3 (S52).

  The stroke positions of the right wheels of the wheel 3b and the wheel 3d are compared (S54). If the stroke position of the wheel 3b as the right front wheel is higher than the stroke position of the wheel 3d as the right rear wheel (Y in S54), the stroke positions of the left wheels of the wheel 3a and the wheel 3c are compared (S56). If the stroke position of the wheel 3a, which is the left front wheel, is higher than the stroke position of the wheel 3c, which is the left rear wheel (Y in S56), the ECU 10 determines that the vehicle body 2 is in the leaning posture. The stroke position is corrected (S58). The left wheel correction amount (ΔLL) and the right wheel correction amount (ΔRR) are obtained by the following equations.

ΔLL = | St (FL) −St (RL) | / 2
ΔRR = | St (FR) −St (RR) | / 2
Since the vehicle body 2 is tilted rearward, the ECU 10 lowers the stroke position of the wheel 3a, which is the left front wheel, by ΔLL, and lowers the stroke position of the wheel 3b, which is the right front wheel, by ΔRR. Correct the position. Further, the ECU 10 corrects the stroke position of the rear wheel so that the stroke position of the wheel 3c as the left rear wheel is increased by ΔLL, and the stroke position of the wheel 3d as the right rear wheel is increased by ΔRR. Accordingly, the ECU 10 can adjust the relative displacement amount between the sprung and unsprung so that the vehicle body 2 and the road surface are parallel to each other.

  On the other hand, if the stroke position of the wheel 3b as the right front wheel is not higher than the stroke position of the wheel 3d as the right rear wheel (N in S54), the left wheels of the wheel 3a and the wheel 3c are compared with each other. Are compared (S60). If the stroke position of the wheel 3c, which is the left rear wheel, is higher than the stroke position of the wheel 3a, which is the left front wheel (Y in S60), the ECU 10 determines that the vehicle body 2 is in the forward leaning posture. The stroke position is corrected (S62).

  Since the vehicle body 2 is tilted forward, the ECU 10 increases the stroke position of the wheel 3a, which is the left front wheel, by ΔLL, and increases the stroke position of the wheel 3b, which is the right front wheel, by ΔRR. Correct. Further, the ECU 10 corrects the stroke position of the rear wheel so that the stroke position of the wheel 3c as the left rear wheel is lowered by ΔLL, and the stroke position of the wheel 3d as the right rear wheel is lowered by ΔRR. Accordingly, the ECU 10 can adjust the relative displacement amount between the sprung and unsprung so that the vehicle body 2 and the road surface are parallel to each other.

  In S56, the stroke position of the wheel 3a that is the left front wheel is not higher than the stroke position of the wheel 3c that is the left rear wheel (N in S56), and the stroke position of the wheel 3c that is the left rear wheel in S60. Is not higher than the stroke position of the wheel 3a that is the left front wheel (N in S60), the ECU 10 ends the vehicle height adjustment control flow in the front-rear direction without correcting the stroke position.

  In the above example, the vehicle height is adjusted so that the stroke position of each wheel is adjusted to the middle position between the stroke positions of the front and rear wheels. However, the vehicle height is adjusted to the higher stroke position or the lower stroke position. Vehicle height adjustment may be performed. When the vehicle speed is low, it may be controlled to increase the vehicle height in order to avoid interference with the road surface. On the other hand, when the vehicle speed is high, it may be controlled to decrease the vehicle height to ensure driving stability. Good. The ECU 10 preferably measures the vehicle speed from the detection result of the wheel speed sensor 6 and adjusts the stroke position of each wheel based on the measured vehicle speed.

  The present invention has been described above based on the embodiments. The present invention is not limited to this embodiment, and various modifications thereof are also effective as aspects of the present invention.

It is a figure which shows the structure of the vehicle which concerns on embodiment. It is a figure which shows the structure of an electromagnetic suspension. It is a figure which shows the time variation example of the electric current applied to a motor by ECU. It is a flowchart of vehicle height adjustment control. It is a flowchart of the vehicle height adjustment control when the vehicle body is tilted in the left-right direction. 7 is a flowchart of vehicle height adjustment control when the vehicle body is tilted in the front-rear direction.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Vehicle, 2 ... Vehicle body, 3 ... Wheel, 4 ... Electromagnetic suspension, 5 ... Current sensor, 6 ... Wheel speed sensor, 10 ... ECU, 20 ... Motor, 22 ... Coil spring, 24 ... Ball screw, 26 ... Ball screw nut, 28 ... Rod, 30 ... Outer shell, 32, 34, 36 ... Bearing, 38 ... -Dust seal, 40 ... 1st attachment part, 42 ... Spring seat, 44 ... Rotation angle sensor, 46 ... 2nd attachment part.

Claims (5)

  Absorber that generates a damping force between the sprung and unsprung parts of the vehicle using a motor, power control means for controlling the power applied to the motor, and traveling on a rough road from the amount of power applied to the motor A vehicle suspension device comprising: determination means for determining whether or not.   The vehicle suspension apparatus according to claim 1, wherein the determination unit determines whether or not the vehicle is traveling on a rough road based on an amount of electric power applied to the motor and an application time of the electric power. .   When the determination unit determines that the vehicle is traveling on a rough road, a rough road corresponding adjustment unit that adjusts the relative displacement amount between the sprung and unsprung by the motor so as to avoid interference between the vehicle body and the road surface. The vehicle suspension device according to claim 1, further comprising:   The vehicle suspension apparatus according to claim 3, wherein the rough road correspondence adjusting means adjusts a relative displacement amount between the sprung and unsprung portions in a direction of increasing a distance between the vehicle body and the road surface.   When the determination unit determines that the vehicle is not traveling on a rough road, the vehicle further includes a good road correspondence adjustment unit that adjusts the relative displacement amount between the sprung and unsprung by the motor so that the vehicle body and the road surface are parallel to each other. The vehicle suspension device according to any one of claims 1 to 4, wherein

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