Suspension device

Abstract

To provide a suspension device that vertically displaces a vehicle by a low driving force.SOLUTION: This suspension device comprises: a first suspension 100 including a knuckle 13, a lower arm 15, a shock absorber 12, and a main spring 11; and a second suspension 200 including a main arm 21 swung by a hinge shaft 69 and connected at one end to the lower arm 15, a driven sub-spring seat link 28 connected at one end to the other end of the main arm 21, a sub-spring 24 connected at one end to the other end of the driven sub-spring seat link 28, a driving sub-spring seat link 27 connected to the other end of the sub-spring 24, two parallel links connected to both ends of the driving sub-spring seat link 27 and each including a first link 22, a second link 23, and a driving link 25, and a motor 26 for operating the parallel links. When the motor 26 is driven, a distance between the sub-spring 24 and the hinge shaft 69 is changed.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a suspension device.

Background Art

[0002] In recent years, in order to displace a general four-wheel vehicle vertically, a device that controls and displaces the pressure of air or oil in an absorber has been put into practical use. However, there is also a method of displacing a spring with an electric actuator to displace the vehicle height.

[0003] Here, as one proposal for a method of providing a function of expanding and contracting the spring of a suspension, Non-Patent Document 1 discloses a method of using the springs of the suspension that supports one wheel as a main spring and a sub-spring, respectively distributing the load to each, and moving the vehicle body up and down by varying the load sharing ratio of the sub-spring.

Prior Art Documents

Non-Patent Documents

[0004]

Non-Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the configuration described in Non-Patent Document 1, the operating efficiency is poor and a large driving force is required to displace the spring. Therefore, there is a desire to improve the efficiency of the spring displacement operation and reduce the driving force required for the operation.

[0006] The present disclosure provides a suspension device that displaces a vehicle vertically with a low driving force.

Means for Solving the Problem

[0007] The suspension device according to the present disclosure includes a knuckle that supports a wheel provided on a vehicle body, a lower arm that attaches the wheel to the vehicle body via the knuckle so that the wheel can move up and down with respect to the vehicle body, a shock absorber attached to the lower arm, a main spring that is arranged coaxially with the shock absorber and supports the load of the vehicle body, a first suspension portion having the above components, a main arm that is swingable about a hinge axis and has one end connected to the lower arm, a driven sub-spring seat link having one end hinge-connected to the other end of the main arm, a sub-spring having one end hinge-connected to the other end of the driven sub-spring seat link, a driving sub-spring seat link having one end hinge-connected to the other end of the sub-spring, two parallel links that are hinge-connected to both ends of the driving sub-spring seat link and each have a first link, a second link, and a driving link, and a motor that drives the driving link to operate the first link and the second link. The second suspension portion having the above components is provided. When the motor is driven to operate the first link and the second link, the distance between the sub-spring and the hinge axis where the main arm abuts is changed. Thereby, according to the driving force of the motor, the force with which the main arm presses the lower arm can be changed.

Advantages of the Invention

[0008] According to the present disclosure, a suspension device that displaces a vehicle up and down with low driving force can be provided.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Mode for Carrying Out the Invention

[0010] Embodiment 1 Hereinafter, the suspension according to this embodiment will be described with reference to the drawings. FIGS. 1(a) and 1(b) are schematic perspective views of a suspension composed of a first suspension unit 100 and a second suspension unit 200 according to an embodiment of the present invention. In the following description, the same reference numerals are given to the same components. Note that FIG. 1(a) shows a state where the vehicle height is low, and FIG. 1(b) shows a state where the vehicle height is high.

[0011] The first suspension unit 100 is an existing suspension device. The first suspension unit 100 is a device for suspending a wheel 300 (a structure below the spring) from the vehicle body side so that the wheel 300 can move up and down with respect to a vehicle body (a structure above the spring) (not shown). The first suspension unit 100 includes a chassis spring 11, a shock absorber 12, a knuckle 13, an upper arm 14, and a lower arm 15.

[0012] The chassis spring 11 (main spring) is disposed between the wheel 300 and the vehicle body, supports the load of the vehicle body, and alleviates impacts and vibrations from the road surface.

[0013] The shock absorber 12 is disposed coaxially with the chassis spring 11 and attenuates the vertical vibration of the vehicle body. The upper ends of the chassis spring 11 and the shock absorber 12 are attached to the vehicle body. The lower end of the shock absorber 12 is attached to the lower arm 15.

[0014] The knuckle 13 rotatably supports the wheel 300 via a hub bearing (not shown). One end of the upper arm 14 is connected to the upper part of the knuckle 13, and the other end is attached to the vehicle body side, supporting the upper part of the knuckle 13. One end of the lower arm 15 is connected to the lower part of the knuckle 13, and the other end is attached to the vehicle body side, supporting the lower part of the knuckle 13. The upper arm 14 and the lower arm 15 are attached to the vehicle body side so that the wheel 300 can move up and down with respect to the vehicle body.

[0015] Here, FIGS. 2(a) and 2(b) show the mechanism diagrams of the suspension device. As shown in FIGS. 1(a), 1(b), 2(a), and 2(b), the second suspension unit 200 includes a main arm 21, a first link 22, a second link 23, a sub-spring 24, a drive link 25, a motor 26, a drive sub-spring seat link 27, a driven sub-spring seat link 28, and a main hinge portion 29.

[0016] The main arm 21 is an L-shaped arm with one end connected to the lower arm 15. The first arm is hinge-connected at an intermediate portion in a state where it can swing by the main hinge portion 29 which is a hinge shaft. Also, a driven sub-spring seat link 28 is connected to the other end of the main arm 21. Let the length of the main arm 21 be length C.

[0017] The driven sub-spring seat link 28 has one end connected to the main arm 21 and the other end hinge-connected to the sub-spring 24.

[0018] One end of the sub-spring 24 is connected to the driven sub-spring seat link 28, and the other end is hinge-connected to the drive sub-spring seat link 27.

[0019] At both ends of the drive sub-spring seat link 27, they are respectively hinge-connected to the drive link 25 of the parallel link 31 (see Fig. 2(b)). This parallel link 31 has the same configuration, and is composed of a first link 22, a second link 23, and a drive link 25 respectively connected to the first link 22 and the second link 23.

[0020] Also, a motor 26 is connected to the drive link 25. When the drive link 25 operates by the power given from the motor 26, the first link 22 is driven and the second link 23 is driven. This is the same for each of the parallel links 31 provided at both ends of the drive sub-spring seat link 27.

[0021] In this way, in the second suspension unit 200, by applying a driving force to the drive link 25 by the motor 26, the first link 22 and the second link 23 are operated, and as a result, the extending direction of the sub-spring 24 can be changed.

[0022] Next, the action of changing the vehicle height by changing the load sharing between the main spring 11 and the sub-spring 24 by operating the second suspension unit 200 will be described.

[0023] In the second suspension unit 200, by operating the parallel link 31 composed of the first link 22, the second link 23, and the drive link 25 by the motor 26, the position on the main arm 21 side of the sub-spring 24 is changed. Thereby, the direction of the thrust of the sub-spring 24 can be changed, the torque as a mechanism can be changed, and the load sharing of the sub-spring 24 can be changed.

[0024] More specifically, let the reaction force of the sub-spring 24 be F A , and let the distance between the reaction force direction of the sub-spring 24 and the main hinge portion 29 be B. In other words, for the sub-spring 24, the distance between the extending direction between the drive sub-spring seat link 27 and the driven sub-spring seat link 28, and the main hinge portion 29 with which the main arm 21 abuts, is B. That is, the distance B is the spring axis offset amount.

[0025] This distance B increases or decreases when the motor 26 rotationally drives the drive link 25. Therefore, the torque for rotating the main arm 21 calculated by the product of the reaction force F A and the distance B changes. In response to this change in torque, the load F D with which the main arm 21 presses the lower arm 15 changes.

[0026] At this time, the value of the reaction force F A of the auxiliary spring 24 changes. However, since the change amount of the distance B is large, the increase or decrease of the load F D is dominated by the change in the distance B. Therefore, in response to the motor 26 rotationally driving the drive link 25, the load F D can be changed.

[0027] Therefore, as shown in Fig. 2(a), when the arrangement has a short distance B which is the spring axis offset amount, the downward load F D applied from the main arm 21 to the lower arm 15 becomes small, and the state where the wheel 300 rises, that is, the state where the vehicle height decreases. On the other hand, as shown in Fig. 2(b), in the arrangement where the distance B which is the spring axis offset amount becomes long, the downward load F D applied from the main arm 21 to the lower arm 15 becomes large, and the state where the vehicle height rises. Note that Fig. 2(a) corresponds to Fig. 1(a), and Fig. 2(b) corresponds to Fig. 1(b).

[0028] Here, in the second suspension unit 200, since a structure for changing the direction of the auxiliary spring 24 is adopted by using a plurality of parallel links 31 composed of the first link 22, the second link 23, and the drive link 25, the force for changing the direction of the auxiliary spring 24 can be reduced. That is, in the second suspension unit 200, the power consumption of the motor 26 for operating the parallel link 31 can be reduced, and the motor 26 can be miniaturized.

[0029] Here, FIGS. 2(a) and 2(b) show a configuration in which in the second suspension unit 200, the motor 26 is provided on each parallel link 31 while being connected to the first link 22. In this configuration, by operating the motor 26, the position of the motor 26 itself moves without being fixed.

[0030] On the other hand, as shown in FIGS. 1(a) and 1(b), the second suspension unit 200 can be configured to have only one motor 26, and the parallel link 31 can be connected to the motor 26 via a belt. More specifically, the drive link 25 provided on each parallel link 31 can be driven by a belt provided on the drive unit of the motor 26. In this way, each parallel link 31 can be operated by the power from one motor 26. Note that the method of transmitting power from the motor 26 to the parallel link 31 is not limited to a belt, and another method such as a gear can also be used.

[0031] In this way, when the configuration is such that only one motor 26 is provided, the second suspension unit 200 can fix the motor 26 by arranging the motor 26 on the vehicle body side (hereinafter referred to as above the spring) when the suspension spring is divided vertically. In other words, by arranging the motor 26 above the spring, a configuration can be achieved in which the position of the motor 26 itself does not change according to the movement of the motor 26.

[0032] In this case, since the motor 26 is fixedly arranged in the second suspension unit 200, it is easy to unitize. Further, in the second suspension unit 200, since the movable part is not required for the wiring connected to the motor 26, it is easy to arrange on the vehicle body, and there is an advantage that the reliability is improved.

[0033] Also, as described above, in the second suspension unit 200, the method related to the operation of the auxiliary spring 24 is not a crank rotation orbit type that holds one end of the auxiliary spring 24 with a single crank, but a parallel link type that uses the parallel link 31. In this way, in the second suspension unit 200, by adopting the parallel link type, the load is dispersed by a large number of hinges, so that the advantage of being able to reduce the bracing force of the motor 26 can be obtained.

[0034] FIG. 3(a) is a diagram showing an example of the relationship between the vehicle height displacement amount in the state where the vehicle is fully loaded (full load) and the torque output by the motor 26, and FIG. 3(b) is a diagram showing an example of the relationship between the vehicle height displacement amount in the state where the vehicle is not loaded (empty vehicle) and the torque output by the motor 26. From FIGS. 3(a) and 3(b), it is shown that in the suspension device, the vehicle height can be changed by driving the motor 26 to exert the function of the second suspension unit 200 regardless of whether a load is loaded on the vehicle body.

[0035] Here, as an example of the conditions, the distance B which is the offset amount is 174.4 mm, the thrust F D for adjusting the vehicle height has a value of 11097.4 N, the main spring reaction force F E is 5565.9 N, the auxiliary spring reaction force F A has a value of 16092.5 N, the axle load at full load applied to the wheel 300 is 9055.2 N, and the axle load at empty vehicle is 6164.2 N. Also, the length C of the main arm 21 is 250 mm, and the arm ratio between the main arm 21 and the lower arm 15 is 0.5.

[0036] As shown in FIGS. 3(a) and 3(b), when the vehicle is loaded with a load, the output torque of the motor 26 required to adjust the height of the vehicle body becomes larger. Therefore, for example, when selecting the motor 26 used in the second suspension unit 200, the type of the motor can be determined based on the output torque in the state where the vehicle is loaded with a load.

[0037] Note that the present invention is not limited to the above-described embodiments, and can be appropriately modified without departing from the spirit thereof. That is, the above description has been appropriately omitted and simplified for the sake of clarity of explanation, and those skilled in the art can easily change, add, and transform each element of the embodiment within the scope of the present invention.

Explanation of Reference Numerals

[0038] 11 Main spring 12 Shock absorber 13 Knuckle 14 Upper arm 15 Lower arm 21 Main arm 22 First link 23 Second link 24 Auxiliary spring 25 Drive link 26 Motor 27 Drive auxiliary spring seat link 28 Driven auxiliary spring seat link 29 Main hinge portion 31 Parallel link 100 First suspension portion 200 Second suspension portion 300 Wheel

Claims

Claim 1 A knuckle that supports a wheel provided on a vehicle body, A lower arm that attaches the wheel to the vehicle body via the knuckle so that the wheel can move up and down with respect to the vehicle body, A shock absorber attached to the lower arm, A first suspension unit having a main spring that is arranged coaxially with the shock absorber and supports the load of the vehicle body, A main arm that is swingable about a hinge axis and has one end connected to the lower arm, A driven auxiliary spring seat link having one end hinge-connected to the other end of the main arm, An auxiliary spring having one end hinge-connected to the other end of the driven auxiliary spring seat link, A drive auxiliary spring seat link hinge-connected to the other end of the auxiliary spring, Two parallel links that are hinge-connected to both ends of the drive auxiliary spring seat link and each have a first link, a second link, and a drive link, A second suspension unit having a motor that operates the first link and the second link by driving the drive link, When the motor is driven to operate the first link and the second link, the distance between the auxiliary spring and the hinge axis where the main arm abuts is changed, A suspension device.

Images