JP2020108994A - Vehicle height adjustment device - Google Patents

Abstract

To provide a vehicle height adjustment device capable of solving the problem that many of various types of conventional vehicle height adjustment devices already proposed and put into practical use, require, for a vehicle that is not mounted with a vehicle height adjustment device, not only replacement of a shock absorber of a suspension but also installation of auxiliary devices including power sources for adjusting the vehicle height on a vehicle body side, resulting in inevitable increase in costs, weight, failure risks, and maintenance costs.SOLUTION: The present invention can solve the above-mentioned problem by providing a screw mechanism inside a coil spring of a suspension, thereby, integrating an electric motor and a speed reducer for driving the screw mechanism, with a shock absorber so as to eliminate requirement of a pneumatic power source, a hydraulic power source, pneumatic piping, hydraulic piping, and the like which are conventionally mounted on a vehicle body side.SELECTED DRAWING: Figure 1

Description

The present invention relates to a vehicle height adjusting device for a vehicle.

As a vehicle height adjusting device for a vehicle, for example, there is an existing air suspension system shown in "Non-Patent Document 1".

In the air suspension system of "Non-Patent Document 1", the shock absorber needs to be replaced for the air suspension, and many parts such as an air pump and an air tank need to be mounted on the vehicle body side.

"Automobile suspension structure, theory and evaluation" edited by KYB Co., Ltd. Grand Prix Publishing Co., Ltd. 204 pages ISBN978-4-87687-330-2 C2053

In the air suspension system of "Non-Patent Document 1," it is necessary to replace the shock absorber for the air suspension, and it is necessary to mount many parts such as an air pump and an air tank on the vehicle body side. Weight and cost increase.
There is also a problem that the risk of failure such as air leakage increases and maintenance costs that were not required in the past are incurred.

In the present invention, the screw mechanism is provided inside the coil spring of the suspension, the electric motor for driving the screw mechanism, and the speed reducer integrally configured with the shock absorber to minimize the pneumatic pressure source and hydraulic pressure source mounted on the vehicle body side. In addition, since the pneumatic piping and hydraulic piping are not used, the risk of failure is minimized and the above problems are solved.

Example 1, standard height state of Example 1 Example 1 A state in which the vehicle height of Example 1 is increased Example 2, Example of mounting on strut type steered wheels Example 3, Example in which a plurality of motors are installed Example 4, Example in which a coaxial motor is installed Example 5, Example in which a brake mechanism and a control circuit are integrated with a motor

FIG. 1 shows a vehicle height adjusting device for a vehicle according to the first embodiment.

The upper end of the suspension coil spring 6 is fixed to the vehicle body via the spring upper seat 4. The suspension coil spring 6 is fixed to the vehicle body by the fixing pin 24, and does not rotate in the rotation direction of the screw formed by the ball screw male screw 10 and the ball screw female screw 8.

The shock absorber outer cylinder 14 is attached to a suspension (not shown) attached to the vehicle body by a rubber bush composed of 15, 16 and 17, and is composed of a ball screw male screw 10 and a ball screw female screw 8. It does not rotate in the screw rotation direction.
In the first embodiment, the ball screw is adopted as the screw mechanism inside the suspension coil spring, but the function of FIG. 2 is not changed even if it is replaced with a screw of another system such as a trapezoidal screw.

Here, the drive motor 18 attached to the shock absorber outer cylinder 14 rotates the pinion gear 13 via the reduction gear 19. The pinion gear 13 meshes with the driven gear 11, and rotates the ball screw male screw 10.
The ball screw male screw 10 is rotatably connected to the shock absorber 14 by a ball bearing 12 and a thrust ball bearing 22.

The ball screw female screw 8 is connected to the lower end of the suspension coil spring 6 by the fixing pin 23 and cannot rotate in the rotation direction of the ball screw.
Therefore, the ball screw female screw 8 does not rotate, but the ball screw male screw 10 rotates.

As a result, the case where the ball screw female screw 8 moves upward in the figure and upward in the vehicle body is shown in FIG.
In FIG. 1, the ball screw female screw 8 is in close contact with the ball screw male screw 10 and the distance h is substantially zero, whereas in FIG. 2, h is about 40 mm. The vehicle height corresponding to this distance h is adjusted. The length H of the entire shock absorber is extended by the same length as the distance h of FIG. 2 in FIG. 2 as compared with the state of FIG.

The amount of change in the vehicle height of the vehicle body is a value obtained by multiplying the distance h by the lever ratio of the suspension. Since the lever ratio of the suspension is normally around 1.4, it is possible to adjust the vehicle height by about 50 mm with the normal suspension.

In the first embodiment, the case where the distance h shown in FIG. 1 is zero is the normal traveling time. As a result, even if the vehicle height adjusting device breaks down when the vehicle height rises, the distance h returns to the zero position due to the weight of the vehicle body, so that normal traveling is not hindered.
It is naturally possible to set the distance h during normal traveling to a value other than zero.

The vehicle height adjusting device according to the first embodiment requires a vehicle height sensor that detects the control amount of the vehicle height. There are many existing vehicle height sensors that have already been commercialized and commercialized. In the present invention, it is of course possible to use an existing vehicle height sensor, but in a brushless motor or the like, a rotation sensor is incorporated in the motor for controlling the motor itself. In the present invention, since the relationship between the rotation speed of the motor and the vehicle height is constant, the rotation sensor incorporated in the motor can be used as the vehicle height sensor. This eliminates the need to attach a separate vehicle height sensor, and improves cost, weight, and mountability.

1 and 2, the motor 18 and the control circuit 26 are connected by a motor control line 25. The control circuit 26 is installed on the vehicle body.

FIG. 3 shows an embodiment in which the present invention is applied to a strut type steered wheel. The present invention can be directly applied to the strut type steered wheels. However, in Example 1 of FIGS. 1 and 2, the relative rotation angle between the male screw 10 and the female screw 8 of the ball screw is generated only by driving the motor 18, but in the strut-type steered wheel of FIG. At the same time, the turning causes relative rotation of the male screw 10 and the female screw 8.

When the male screw 10 and the female screw 8 of the ball screw of the right wheel and the left wheel are, for example, both right screws, the vehicle height of the right wheel and the vehicle height of the left wheel are lowered by the right steering. In the case of left steering, both the vehicle height of the right wheel and the vehicle height of the left wheel increase, and a problem occurs in which the vehicle moves asymmetrically when steering left and right.

In order to avoid this problem, in the second embodiment of FIG. 3, the right-hand ball screw has a right-hand thread, the left-wheel ball screw has a left-hand thread, and the left-right wheel has opposite screw directions. As a result, the movement of the vehicle is targeted by right steering and left steering. Depending on the required height change of the vehicle, the ball screw for the right wheel can be left-handed or left-handed. ..

FIG. 4 shows Embodiment 3 and is characterized in that a plurality of sets of drive motors and reduction gears are provided. In FIG. 2, the set of the drive motor and the speed reducer is two, but it is also possible to set two or more.

By using multiple drive motors and reducers, 1. By reducing the size of the motor and the speed reducer, it is possible to reduce the d dimension in FIG. 4 and improve the vehicle mountability. 2. The speed of vehicle height adjustment can be improved by installing a plurality of motors and reduction gears of the same size as the case where there is one motor and reduction gears.
And the like.

Further, by using a plurality of motors and reduction gears, an eccentric load acting on the ball bearing 12 is reduced, the operation is smooth, and the durability is improved.

Example 4 is shown in FIG. The fourth embodiment is characterized in that the coaxial motor 34 is used as a drive motor. In the fourth embodiment, a known harmonic drive reduction mechanism 33 is used as a reduction gear.
Since the harmonic drive speed reduction mechanism can reduce the speed by about 1/100 by itself, the gear mechanism is not required in the 32 part of FIG. 5, and the 32 part has a fitting structure.

In the fourth embodiment, by using the coaxial motor 34, it is possible to further reduce the dimension d in FIG. 5 as compared with the third embodiment, and it is possible to reduce restrictions when mounting on the vehicle body.

Example 5 is shown in FIG. In the fifth embodiment, a known technology such as an electromagnetic brake 37, a motor control circuit, and a wireless transmission/reception circuit 35 are mounted coaxially with the drive motor 18. This eliminates the need for a motor current when the vehicle height is kept constant, so that the drive motor 18 can be mounted on the vehicle by connecting only the power supply line.

In recent years, the number and size of electronic devices mounted on vehicles have increased, and it has become difficult to mount a new motor control circuit or the like on the vehicle body side due to physical space restrictions. In this situation, integrating the motor control circuit and the like shown in the fifth embodiment is a very effective means for mounting a new device on the vehicle body.

The vehicle height adjusting device according to the present invention is smaller and lighter in weight than the conventional vehicle height adjusting device and has a small number of parts mounted on the vehicle body, and is excellent in vehicle mountability. Moreover, the risk of failure is low and the maintenance cost is increased. It is possible to realize a vehicle height adjusting device for a vehicle that can minimize the above.
As a result, it becomes possible to mount the vehicle on a small car, a mass car, a sports car, etc. for which the vehicle height adjusting device could not be mounted conventionally in terms of cost and weight.

1 Shock absorber piston rod screw 2 Shock absorber body mounting nut 3 Body panel 4 Spring upper seat 5 Shock absorber piston rod 6 Suspension coil spring 7 Ball screw dust cover 8 Ball screw female screw 9 Gear part dust cover 10 Ball screw male screw 11 Driven Gear 12 Ball Bearing 13 Pinion Gear 14 Shock Absorber Outer Cylinder 15 Rubber Bush Outer Cylinder 16 Rubber Bush Rubber Part 17 Rubber Bush Inner Cylinder 18 Drive Motor 19 Reducer 20 Thrust Ball Bearing Lower Bearing 21 Rotating Sliding Bushing 22 Thrust Ball Bearing 23 Fixed pin 24 Fixed pin 25 Motor control line 26 Motor control circuit 27 Speed reducer 28 First drive motor 29 Speed reducer 30 Second drive motor 31 Dust cover 32 Fitting portion 33 Harmonic drive speed reduction mechanism 34 Coaxial motor 35 Control circuit and wireless transmission/reception circuit 36 Power line 37 Spindle 38 Electromagnetic brake

Claims (4)

As a vehicle height adjuster 1. A screw mechanism provided inside the coil spring of the suspension.
2. A male screw with a screw mechanism that is rotatably connected to the shock absorber.
3. Female screw with a screw mechanism connected to the coil spring.
4. At least one electric motor installed on the shock absorber to drive the male screw of the screw mechanism.
Vehicle height adjustment device characterized by having both. The vehicle height adjusting device according to claim 1, wherein a state of the lowest vehicle height is a normal traveling state. When the structure according to claim 1 is combined with a strut-type steered wheel, the vehicle height adjusting device is characterized in that the screw mechanism provided inside the coil spring has the left and right wheels in opposite directions. A vehicle height adjusting device, wherein a ball screw is used as the screw mechanism of "claim 1" and "claim 2".