Vehicle height adjustment device

Abstract

To reduce output of an inclination changing device.SOLUTION: A vehicle height adjustment device according to the present invention includes: a main spring and an auxiliary spring that are provided in parallel with each other between a wheel-side member and a vehicle body-side member; and an inclination changing device that changes an inclination of the auxiliary spring. The inclination changing device changes vehicle height by changing an inclination of the auxiliary spring, thereby changing a rate of load assigned by the auxiliary spring. The inclination changing device changes the inclination of the auxiliary spring, therefore output of an actuator of the inclination changing device can be made smaller than in the case of changing inclinations of a shock absorber and the main spring.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a vehicle height adjusting device for adjusting a vehicle height. [Background technology]

[0002] The vehicle height adjusting device described in Patent Document 1 is attached to a suspension including a suspension arm, and a shock absorber and main spring arranged in parallel between the suspension arm and the vehicle body. The shock absorber body is attached to the suspension arm, the piston rod is attached to the vehicle body, and the main spring is held between a lower retainer attached to the shock absorber body and an upper retainer attached to the vehicle body.

[0003] The vehicle height adjustment device described in Patent Document 1 includes an inclination change device that changes the inclination of the shock absorber and the main spring. The inclination change device changes the position of the lower end of the shock absorber (the mounting position relative to the suspension arm) to change the inclination of the shock absorber and the main spring. The inclination change device includes an actuator and a generally L-shaped drive member. The drive member is rotatably mounted to the suspension arm at its middle, connected to the lower end of the shock absorber at one end, and connected to the actuator at the other end. The actuator rotates the drive member, moving one end of the drive member between a first position and a second position that is inward and lower than the first position on the vehicle. This moves the lower end of the shock absorber between the first position and the second position, changing the inclination of the shock absorber and the main spring and thereby changing the vehicle height. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 5-238225 Summary of the Invention [Problem to be solved by the invention]

[0005] An object of the present invention is to reduce the output of the tilt change device. [Means for solving the problem]

[0006] The vehicle height adjusting device according to the present invention includes a main spring and an auxiliary spring arranged in parallel between a wheel-side member and a vehicle body-side member, and a tilt change device that changes the tilt of the auxiliary spring. The tilt change device changes the tilt of the auxiliary spring, thereby changing the load distribution of the auxiliary spring and thereby changing the vehicle height. Because the tilt change device changes the tilt of the auxiliary spring, the output of the tilt change device can be smaller than when the tilt of the shock absorber and the main spring is changed. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a perspective view of a vehicle height adjusting device according to an embodiment of the present invention; [Figure 2] FIG. 2 is a front view of the vehicle height adjusting device. [Figure 3] FIG. 2 is a front view illustrating an operating state of the vehicle height adjusting device. [Figure 4] FIG. 6 is a front view illustrating another operating state of the vehicle height adjusting device. [Figure 5] FIG. 10 is a front view illustrating still another operating state of the vehicle height adjusting device. [Figure 6] 1A is a diagram showing the output torque of the actuator, (b) is a diagram showing the motor rotation angle, and (c) is a diagram showing the vehicle height, which change with the operation of the vehicle height adjusting device. [Figure 7] 2 is a diagram showing the periphery of a control device included in the vehicle height control device. FIG. [Figure 8] 4 is a flowchart showing a vehicle height adjustment program stored in a storage unit of the control device. Embodiments of the invention

[0008] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A vehicle height adjusting device according to an embodiment of the present invention will now be described with reference to the accompanying drawings. 1 and 2-5, the vehicle height adjusting device can be provided, for example, between a lower arm 6 serving as a suspension arm of a double wishbone suspension and a vehicle body member 8. One end of the lower arm 6 is rotatably connected to a wheel holding member (not shown) of a wheel 10 via a connecting portion 6a, and the other end is rotatably connected to the vehicle body member 8 about an axis P1 extending in the longitudinal direction of the vehicle. [Example]

[0009] The suspension includes a lower arm 6, a shock absorber 12 provided between the lower arm 6 and a vehicle body side member 8, a main spring 14 provided in parallel with the shock absorber 12, and an upper arm (not shown). The shock absorber 12 includes a main body 12h and a piston 12p fitted to the main body 12h so as to be relatively movable. The main body 12h is attached to the lower arm 6 or a wheel holding member, and the piston rod of the piston 12p is attached to a vehicle body member 8. The main spring 14 is constantly held in a compressed state by a pair of retainers 14i, 14j. Of the pair of retainers, the lower retainer 14i is attached to the main body 12h of the shock absorber 12, and the upper retainer 14j is attached to the vehicle body member 8. The main spring 14 is disposed with its axis extending generally in the vertical direction. Hereinafter, in this specification, the lower arm 6, the wheel holding member, etc. may be referred to as the wheel-side member 6.

[0010] This vehicle height adjusting device includes the main spring 14, a housing 20 (part of the vehicle body member 8) fixedly attached to the vehicle body member 8, an auxiliary spring 22 provided between the wheel-side member 6 and the housing 20, and an inclination change device 24 that changes the inclination of the auxiliary spring 22. As shown in FIG. 2-5, the inclination of the auxiliary spring 22 can be expressed, for example, by the angle (inclination angle) θ of the axis Ls of the auxiliary spring 22 relative to a line Lv extending in the vertical direction. In the case shown in FIG. 2-5, it is expressed as a counterclockwise angle from the line Lv extending in the vertical direction.

[0011] The vehicle height adjusting device also includes a pair of arm members 28 that are held at an intermediate portion of the housing 20 so as to be rotatable about an axis P2 (an axis parallel to the axis P1) that extends in the front-rear direction. Each of the pair of arm members 28 is connected to each other at one end and connected to the wheel-side member 6 via an engaging member 26, and is connected to the secondary spring 22 at the other end via an arm connecting member 44.

[0012] The tilt change device 24 includes an electric actuator 30 and a link mechanism 32 that is operated by the electric actuator 30 . The electric actuator 30 includes an electric motor and a reducer, and a pair of output members 40 are connected to the rotating shaft 30a of the reducer so as to be rotatable together. Each of the pair of output members 40 has a shape extending in the longitudinal direction, and is connected at one end to the rotating shaft 30a, and at the other end, is connected to one another so as to be rotatable relative to each other while being located on both sides of one drive transmission member 42. The output member 40 rotates in conjunction with the rotation of the electric actuator 30, and the drive transmission member 42 is moved. In this embodiment, the electric actuator 30 is attached to the housing 20.

[0013] The link mechanism 32 includes a pair of first link members 46 connected to the drive transmission member 42 so as to be rotatable relative to each other, and a pair of second link members 48 connected to the pair of first link members 46 so as to be rotatable relative to each other. Although not shown, the drive transmission member 42 has a shape including a central shaft portion and two branch portions that branch off from the central shaft portion. The end portions of the central shaft portion are connected to the pair of output members 40 so as to be able to rotate relative to each other, and each of the branch portions is connected to the middle portions of each of the pair of first link members 46 so as to be able to rotate relative to each other.

[0014] One end of each of the pair of first link members 46 is held by the housing 20 so as to be rotatable relative to the housing 20 about the axis P3. One end of each of the pair of second link members 48 is connected to the other end of the pair of first link members 46 so as to be rotatable relative to the housing 20 about an axis parallel to the axis P3, and the other end of each of the pair of second link members 48 is connected to the secondary spring 22 so as to be rotatable relative to the housing 20 about an axis parallel to the axis P3. In this embodiment, the axis P3 extends in the fore-and-aft direction of the vehicle, and the first link member 46 and the second link member 48, and the second link member 48 and the auxiliary spring 22 are each connected so as to be able to rotate relatively around an axis parallel to the axis P3.

[0015] The secondary spring 22 is a compression spring and is always in a compressed state. Therefore, the direction of the spring force of the secondary spring 22 is the extension direction. The secondary spring 22 is held by a pair of retainers 52, 54. One of the pair of retainers 52, 54, a first retainer 52, is held by the housing 20 so as to be relatively rotatable about an axis P4, and the other, a second retainer 54, is connected to the other end of the pair of second link members 48 so as to be relatively rotatable about an axis parallel to the axis P4. In this embodiment, the axis P4 is parallel to the axis P3 and extends in the fore-and-aft direction of the vehicle.

[0016] An arm connecting member 44 is connected to the second link member 48. The arm connecting member 44 includes a pair of connecting member bodies 44h and a connecting portion 44r that connects the pair of connecting member bodies 44h to each other. Each of the pair of connecting member bodies 44h has one end connected to the other end of the pair of second link members 48, and the other end connected to the other end of the pair of arm members 28 so as to be rotatable relative to each other.

[0017] In this embodiment, the other end of each of the pair of second link members 48, one end of the pair of connecting member bodies 44h of the arm connecting member 44, and the second retainer 54 are all connected by a common connecting shaft 56 so as to be rotatable relative to one another. The second retainer 54 is held in the middle of this connecting shaft 56, and the other end of each of the pair of second link members 48 and one end of the pair of connecting member bodies 44h are held on both sides of the second retainer 54 in a state in which the second retainer 54 is sandwiched between them. Therefore, the spring force of the secondary spring 22 acts on the arm connecting member 44 and the other end of the arm member 28 via the connecting shaft 56. The connecting shaft 56 extends in the front-to-rear direction of the vehicle and is parallel to the axes P3 and P4. The other end of each connecting member body 14h and the other end of each arm member 28 are connected to each other so as to be rotatable relative to each other about axes parallel to the axes P3 and P4.

[0018] It is not essential to provide a pair of each of the first link members 46, the second link members 48, etc. Furthermore, in this vehicle height adjusting device, the pair of first link members 46, the pair of second link members 48, etc. are not operated separately one by one. Therefore, hereinafter in this specification, the pair of first link members 46, the pair of second link members 48, etc. may be simply referred to as the first link members 46, the second link members 48, etc.

[0019] As described above, the spring force Fa of the secondary spring 22 acts on the other end of the arm member 28, and the reaction force Fb from the wheel-side member 6 acts on one end via the engaging member 26. For example, in the case shown in Fig. 2, the position of the arm member 28 and the position of the wheel-side member 6 are determined so that the moment (Fax*La) about the axis P2 resulting from the vertical component Fax of the spring force Fa of the secondary spring 22 acting on the other end of the arm member 28 balances with the moment (Fb*Lb) about the axis P2 resulting from the reaction force Fb from the wheel-side member 6 acting on one end.

[0020] Moreover, the auxiliary spring 22 is held at one end by the vehicle body side member 8, which is the housing 20, via the first retainer 52, and is engaged at the other end by the arm member 28 via the second retainer 54 and the arm connecting member 44, and the arm member 28 is engaged with the wheel side member 6 via the engaging member 26. In this way, the spring force of the auxiliary spring 22 acts between the vehicle body side member 8 and the wheel side member 6 via the arm member 28.

[0021] From the above, it can be considered that the force that the secondary spring 22 acts between the vehicle body side member 8 and the lower arm 6 is the force Fb (reaction force from the wheel side member 6) acting on one end of the arm member 28. Furthermore, when the force Fb acting on one end of the arm member 28 (upward force is taken as a positive value) is large, the load share of the secondary spring 22 becomes larger than when it is small.

[0022] The force Fb acting on one end of the arm member 28 generally changes with changes in the inclination angle θ of the secondary spring 22. As shown in FIG. 2-5, the moment acting on the arm member 28 due to the spring force of the secondary spring 22 acting on the other end of the arm member 28 changes with changes in the inclination angle θ of the secondary spring 22, so the force Fb acting on one end of the arm 28 changes. 2, the length of the arm, i.e., the distance La between the axis P2 and the other end, is longer than the distance Lb between the axis P2 and one end. Therefore, in the case shown in Fig. 2, the force acting between the vehicle body member 8 and the lower arm by the sub-spring 22 (the force Fb acting on one end of the arm member 28) can be made larger than the force Fax acting on the other end of the arm member 28 and contributing to the moment of the arm member.

[0023] On the other hand, the load applied to the wheel 10 is received by the main spring 14 and the secondary spring 22. Therefore, when the inclination angle θ of the secondary spring 22 is large, the load share of the load applied to the wheel 10 borne by the secondary spring 22 is generally smaller than when the inclination angle θ is small, and the load share of the main spring 14 is larger. The compression amount of the main spring 14 increases, and the vehicle height decreases.

[0024] 7, the vehicle height control device is provided with a vehicle height ECU 70 as a control device mainly composed of a computer. Vehicle height sensors 82 provided corresponding to each of the plurality of wheels 10 provided on the vehicle, a boarding / alighting estimation device 84 that estimates the possibility of a person getting on or off, an inertial measurement device 86 that measures the inertial force acting on the vehicle, etc. are connected to the vehicle height ECU 70, and electric actuators 30 provided corresponding to each of the plurality of wheels 10 are also connected.

[0025] The vehicle height sensor 82 detects the vehicle height, which is the height of the vehicle body side member 8 relative to the wheel side member 6, for each of the wheels 10. The boarding / alighting estimation device 84 includes, for example, a communication device capable of communicating with a portable key, a door opening / closing sensor that detects the opening and closing of a door, and estimates whether a person is boarding or alighting by detecting that the vehicle's portable key is approaching the vehicle or by detecting the opening and closing of the vehicle door. The inertial measurement unit 86 measures, for example, acceleration acting on the vehicle in the longitudinal, lateral, and vertical directions, and rotational angular velocities around axes extending in the longitudinal, lateral, and vertical directions. Based on these, the vehicle's running state, changes in attitude, etc. can be obtained.

[0026] In the vehicle height control device configured as described above, the output member 40 is rotated by driving the electric actuator 30, which in turn moves the drive transmission member 42. The first link member 46 is rotated about the axis P3, and the second link member 48 is moved. As a result, the relative position of the second retainer 54 with respect to the first retainer 52 changes, the first retainer 52 is rotated about the axis P4, and the inclination angle θ of the secondary spring 22 changes.

[0027] Furthermore, the arm member 28 is rotated so that the moment due to the spring force of the secondary spring 22 acting on the other end of the arm member 28 balances with the moment due to the reaction force of the lower arm 6, thereby changing the vehicle height. Furthermore, as the tilt angle (posture) θ of the secondary spring 22 changes, the moment due to the spring force of the secondary spring 22 acting on the other end of the arm member 28 changes, and the force Fb acting between the vehicle body side member 8 and the lower arm 6 by the secondary spring 22, i.e., the load share of the secondary spring 22, changes, changing the vehicle height. As shown in FIG. 2-5, in this embodiment, the change in the axial length of the secondary spring 22 is small, and the force Fb acting between the vehicle body side member 8 and the lower arm 6 by the secondary spring 22 changes mainly due to the change in the inclination angle θ.

[0028] As shown in FIG. 6(a), when the rotation angle φ of the electric actuator 30 from the reference position changes, the motor torque changes as shown in FIG. 6(b), and the vehicle height changes as shown in FIG. 6(c).

[0029] The state of the vehicle height control device at time t0 in Figure 6 is shown in Figure 2, and the state at time t1 is shown in Figure 3. Similarly, the states at times t2 and t3 in Figure 6 are shown in Figures 4 and 5, respectively. In the case shown in Figures 2 and 3, the moment acting on the arm member 28 due to the spring force of the auxiliary spring 22 is in a direction that moves the lower arm 6 and the vehicle body side member 8 away from each other (increases the vehicle height), whereas in the case shown in Figures 4 and 5, the moment acting on the arm member 28 due to the spring force of the auxiliary spring 22 is in a direction that moves the lower arm 6 and the vehicle body side member 8 closer to each other (decreases the vehicle height).

[0030] Specifically, in the cases shown in Figures 2, 3, and 5, the moment (Fax*La) due to the spring force of the secondary spring 22 and the moment (Fb*Lb) due to the reaction force Fb from the lower arm 6 are balanced, and in the case shown in Figure 4, the moment (Fa*La') due to the spring force of the secondary spring 22 and the moment (Fb*Lb) due to the reaction force Fb from the lower arm 6 are balanced.

[0031] Although not shown in the drawings, when the moment acting on the arm member 28 due to the spring force of the secondary spring 22 is approximately 0, the load share of the secondary spring 22 is 0, and the load applied to the wheel is borne by the main spring 14. On the other hand, when the load share of the secondary spring 22 is greater than 0, the vehicle height is higher than when the load share of the secondary spring 22 is 0, and when the load share of the secondary spring 22 is less than 0, the vehicle height is lower than that.

[0032] Strictly speaking, as shown in Figures 6(a) and 6(c), due to the structure of the link mechanism 32, there is a region in which the arm member 28 does not rotate and the vehicle height does not change even when the rotation angle φ of the electric actuator 30 changes. However, it is possible to adjust the vehicle height without using this region. In other words, it is desirable to adjust the vehicle height using a region in which the rotation angle φ of the electric actuator and the vehicle height correspond one-to-one.

[0033] In this embodiment, the tilt change device 24 tilts the secondary spring 22 instead of the primary spring 14, and mainly changes the posture (tilt angle θ) without substantially extending the secondary spring 22. As a result, the output of the electric actuator 30 can be reduced. The maximum value of the motor torque relative to the load applied to the wheel 10 can be reduced, and the vehicle height can be changed with a small torque.

[0034] Furthermore, the driving force of the electric actuator 30 is transmitted to the second retainer 54 of the secondary spring 22 via the link mechanism 32, thereby changing the tilt angle θ of the secondary spring 22. Therefore, if the link mechanism 32 is designed to have a boosting function, the output of the electric actuator 30 can be made smaller than the force required to change the tilt angle θ of the secondary spring 22, and the output of the electric actuator 30 can be made even smaller.

[0035] The maximum value of the motor torque can be changed as appropriate by changing the installation position of the electric actuator 30, the design of the length and shape of the output member 40, the design of the link mechanism 32, etc. Furthermore, the change in the motor torque relative to the rotation angle φ of the electric actuator 30 can also be changed as appropriate by changing these designs.

[0036] The attitude (inclination angle θ) of the secondary spring 22 is changed by the link mechanism 32. In the link mechanism 32, the first link member 46 and the housing 20, the first link member 46 and the second link member 48, and the second link member 48 and the second retainer 54 are connected to each other so as to be rotatable about an axis parallel to the axis P3. The first retainer 52 is held by the housing 20 so as to be rotatable about an axis P4 parallel to the axis P3. As a result, the holding portion (connecting shaft 56) of the second retainer 54 is moved in the same plane perpendicular to the axes P3 and P4, and therefore the axis Ls passing through the first retainer 52 and the second retainer 54 is always located in the plane A that includes the first retainer 52 and the second retainer 54. The axis Ls of the secondary spring 22 exists in the plane A even if the inclination angle θ changes, and the attitude (inclination) of the secondary spring 22 is changed two-dimensionally.

[0037] In this way, since the inclination (posture) of the secondary spring 22 is changed two-dimensionally, the space occupied by the secondary spring 22 due to the change in inclination of the secondary spring 22 can be made narrower than when it is changed three-dimensionally, and the vehicle height adjustment device can be made smaller.

[0038] Furthermore, it is possible to increase the length of the arm member 28 between the axis P2 and the other end where the spring force of the secondary spring 22 acts. This makes it easy to ensure the space occupied by the secondary spring 22, thereby improving the degree of freedom in design.

[0039] Furthermore, in this embodiment, since the electric actuator 30 is provided on the vehicle body side member 8 (sprung part), wiring can be made easier compared to when it is provided on the wheel side member 6 (unsprung part). Furthermore, since the electric actuator 30, the sub-spring 22, and the lower arm 6 are connected by the link mechanism 32, the unsprung vibrations are absorbed by the link mechanism 32. As a result, the vibrations transmitted to the electric actuator 30 attached to the spring can be suppressed, and the life of the electric actuator 30 can be extended. Furthermore, the vibrations of the vehicle body member 8 can be suppressed, and a decrease in ride comfort can be suppressed.

[0040] As shown in FIG. 4, at time t2, the secondary spring 22 is in a substantially horizontal position (the tilt angle θ is approximately 90°), but the secondary spring 22 is changed to a position facing upward from the horizontal position (upward position) as shown in FIGS. 2 and 3, and to a position facing downward from the horizontal position (downward position) as shown in FIG. 5. When the secondary spring 22 is in the downward position as shown in FIG. 5, the spring force Fa of the secondary spring 22 acting on the other end of the arm member 28 is downward. The spring force Fa of the secondary spring 22 acting on the other end of the arm member 28 becomes a negative value, and a moment can be applied to the arm member 28 in a direction that brings the lower arm 6 and the vehicle-body member 8 closer to each other. This makes it possible to significantly lower the vehicle height.

[0041] For example, if the vehicle adjustment device sets the vehicle height at time t0 or time t1 to the vehicle height in the steady state, the electric actuator 30 can be operated to lower the vehicle height. For example, while the vehicle is traveling, the vehicle height can be set to a height in a steady state, and when getting on or off, the vehicle height can be lowered to a height suitable for getting on or off.

[0042] An example of this case can be shown in the flowchart of FIG. In step 1 (hereinafter abbreviated as S1, the same applies to the other steps) of the vehicle height control program shown in the flowchart of Fig. 8, it is determined whether the vehicle is stopped, and if the determination is YES, it is determined in S2 whether the ingress / egress estimation device has estimated whether a person is getting on or off. If the determination in either S1 or S2 is NO, no vehicle height adjustment is performed, but if the determination in S1 or S2 is YES, the electric actuator 30 is operated in S3, and the vehicle height is lowered to a height suitable for getting on or off.

[0043] In this way, in this embodiment, when it is predicted that a person will get on or off the vehicle, the vehicle height can be lowered by ΔH or more from the steady state. As a result, the vehicle height can be adjusted to make it easier for people to get on and off when getting on or off. Furthermore, since the output of the electric actuator 30 required to tilt the secondary spring 22 can be small, the operating speed of the electric actuator 30 can be increased accordingly. In this case, the waiting time for people to get on or off the vehicle can be shortened, improving the usability of the vehicle.

[0044] Furthermore, if the vehicle height when the vehicle adjustment device is in the state shown at time t2 is set to the vehicle height in a steady state, the vehicle height can be raised or lowered based on the driving conditions by operating the electric actuator 30. For example, based on the detection results from the inertial measurement unit 86, the vehicle height of each of the front, rear, left and right wheels can be controlled so that the vehicle's posture is maintained in a substantially horizontal direction when turning. Furthermore, when the vehicle is traveling on a rough road, vibrations of the vehicle body member 8 can be suppressed based on the vertical acceleration measured by the inertial measurement device 86.

[0045] In the above embodiment, it is considered that the link mechanism 32 is constituted by the first link member 46, the second link member 48, etc., but it can also be considered that a four-joint link mechanism is constituted by the first link member 46, the second link member 48, the secondary spring 22, and the portion of the housing 20 between the axis P3 and the axis P4. In this case, the four-joint link mechanism has one degree of freedom, and the secondary spring 22 is rotated within the plane A around the axis P4.

[0046] The vehicle height adjusting device can be provided between the upper arm and a vehicle body member. Furthermore, the vehicle height adjusting device can be provided not only to double wishbone suspensions but also to various types of suspensions such as strut suspensions. Furthermore, the present invention can be implemented in various forms with various modifications and improvements made based on the knowledge of those skilled in the art. [Explanation of symbols]

[0047] 6: Lower arm 8: Vehicle body side member 14: Main spring 20: Housing 22: Sub-spring 24: Tilt change device 26: Engagement member 28: Arm member 30: Electric actuator 32: Link mechanism 44: Arm connecting member 46: First link member 48: Second link member 52, 54: Retainer 70: Vehicle height ECU Patentable invention

[0048] (1) A vehicle height adjusting device capable of adjusting a vehicle height, which is the height of a vehicle body side member relative to a wheel side member, a main spring and an auxiliary spring provided in parallel with each other between the wheel-side member and the vehicle-body-side member; a tilt change device that changes the tilt of the secondary spring two-dimensionally; a tilt change device that changes the tilt of the secondary spring to change a load share of the secondary spring and adjust the vehicle height.

[0049] The inclination of the secondary spring can be expressed, for example, as an angle relative to a horizontal line that is a line extending horizontally of the axis of the secondary spring, or as an angle relative to a vertical line that is a line extending vertically of the axis of the secondary spring, etc. The axis of the secondary spring can be a line passing through the center of the secondary spring.

[0050] The load applied to the wheel is borne by both the main spring and the secondary spring. Therefore, when the secondary spring's load share is small, the main spring's load share is larger than when it is large. The amount of compression of the main spring increases, and the vehicle height becomes lower. The load share of the secondary spring can be changed by changing the amount of compression of the secondary spring, but in this embodiment, it is changed by changing the inclination of the secondary spring. Generally, when the inclination of the secondary spring (angle θ with respect to a line extending in the vertical direction) is larger than the set angle, the load share of the secondary spring is smaller and the vehicle height becomes lower compared to when it is small.

[0051] (2) The secondary spring is held by a pair of retainers, A vehicle height adjusting device as described in (1), wherein a first retainer, which is one of the pair of retainers, is rotatably held on the vehicle body side member, and a second retainer, which is the other of the pair of retainers, is engaged with the tilt change device.

[0052] When the second retainer is moved by the tilt change device, the relative positional relationship of the second retainer with respect to the first retainer is changed, and the tilt of the secondary spring is changed.

[0053] (3) The vehicle height adjusting device according to (1) or (2), wherein the tilt changing device includes an electric actuator and a link mechanism operated by the electric actuator.

[0054] The secondary spring is connected to a link member, which is a component of the link mechanism, and the inclination of the secondary spring is changed by moving the link member.

[0055] (4) The vehicle height adjusting device according to (3), wherein the electric actuator is provided on the vehicle body member.

[0056] (5) A vehicle height control device as described in (3) or (4), wherein the link mechanism includes a plurality of link members provided between the secondary spring and a drive transmission member connected to the output member of the electric actuator.

[0057] The drive force of the electric actuator is input to the link mechanism via a drive transmission member, and the output of the link mechanism acts in a direction to tilt the secondary spring. If the link mechanism has a boosting function, the drive force of the electric actuator can be made smaller than the force required to tilt the secondary spring, allowing the electric actuator to be made smaller.

[0058] (6) A vehicle height adjustment device as described in (5), wherein the plurality of link members include a first link member that is held at one end so as to be rotatable relative to the vehicle body side member and connected to the drive transmission member at an intermediate portion, and a second link member that is connected at one end so as to be rotatable relative to the other end of the first link member and connected at the other end to the secondary spring.

[0059] For example, the second retainer of the secondary spring is connected to the second link member, and is thereby moved relative to the first retainer, thereby changing the tilt angle of the secondary spring.

[0060] (7) A vehicle height adjustment device as described in any one of items (1) to (6), wherein the vehicle height adjustment device includes an arm member that is held at an intermediate portion so as to be rotatable relative to the vehicle body side member, that engages with the wheel side member at one end via an engaging member, and that receives the spring force of the secondary spring at the other end.

[0061] The spring force of the auxiliary spring acts between the vehicle body side member and the wheel side member via the arm member and the engaging member.

[0062] (8) The vehicle height control device according to (7), wherein the vehicle height control device includes an arm connecting member connected at one end to the secondary spring and connected at the other end to the other end of the arm member so as to be rotatable relative to the other end.

[0063] The secondary spring is connected to one end of the arm connecting member, and the other end of the arm member is connected to the other end of the arm connecting member. The spring force of the secondary spring acts on the other end of the arm member via the arm connecting member.

[0064] (9) A vehicle height adjusting device according to any one of (1) to (8), wherein the tilt change device is capable of changing the tilt of the secondary spring between an upward tilt and a downward tilt with respect to the horizontal direction.

[0065] (10) The secondary spring is held by a pair of retainers, that is, a first retainer and a second retainer, the first retainer is held by the vehicle body side member so as to be rotatable around a rotation axis, and the second retainer is engaged with the tilt change device, The vehicle height adjustment device described in (9) above, wherein the tilt change device moves the second retainer to a position above or below a line that passes through the rotation axis of the first retainer and extends horizontally, thereby changing the tilt of the secondary spring to an upward tilt or a downward tilt with respect to the horizontal direction.

[0066] When the second retainer is positioned above a horizontal line passing through the pivot axis of the first retainer relative to the vehicle body member, the secondary spring tilts upward, and when the second retainer is positioned below the horizontal line, the secondary spring tilts downward. By tilting the secondary spring downward, the spring force of the secondary spring can be made negative.

[0067] (11) The tilt change device includes an electric actuator and a link mechanism operated by the electric actuator, the electric actuator includes an electric motor and a reducer that changes the rotation speed of the electric motor, The vehicle height control device according to any one of items (1) to (10), further comprising an electric actuator control unit that controls the electric motor to adjust the vehicle height.

[0068] For example, by controlling the electric actuator while the vehicle is running, it is possible to improve the running stability of the vehicle, improve the posture stability, suppress vibration, etc. In the above embodiment, the electric actuator control unit corresponds to the vehicle height ECU 70.

[0069] (12) A vehicle height adjustment device as described in (11), wherein the electric actuator control unit controls the electric motor so as to lower the vehicle height when it is predicted that a person will get on or off the vehicle.

[0070] By changing the inclination of the secondary spring, the vehicle height can be changed to a height suitable for getting on and off.

[0071] (13) A vehicle height adjusting device capable of adjusting a vehicle height, which is the height of a vehicle body side member relative to a wheel side member, a main spring and an auxiliary spring provided in parallel with each other between the wheel-side member and the vehicle-body-side member; an inclination change device that changes the inclination of the secondary spring; a tilt change device that changes the tilt of the secondary spring to change a load share of the secondary spring and adjust the vehicle height.

[0072] The vehicle height adjusting device described in this paragraph may employ any one of the technical features (1) to (12).

Claims

1. A vehicle height adjusting device capable of adjusting a vehicle height, which is the height of a vehicle body side member relative to a wheel side member, a main spring and an auxiliary spring provided in parallel with each other between the wheel-side member and the vehicle-body-side member; A vehicle height adjustment device that includes an inclination change device that changes the inclination of the secondary spring between an upward inclination and a downward inclination relative to the horizontal direction, and that changes the load distribution of the secondary spring by changing the inclination of the secondary spring using the inclination change device, thereby adjusting the vehicle height.

2. the tilt change device includes an electric actuator and a link mechanism operated by the electric actuator, The secondary spring is held by a pair of retainers, 2. The vehicle height adjusting device according to claim 1, wherein a first retainer, one of the pair of retainers, is rotatably held by the vehicle body side member, and a second retainer, the other of the pair of retainers, is connected to the link mechanism.

3. 3. The vehicle height adjusting device according to claim 2, wherein the electric actuator is provided on the vehicle body member.

4. The vehicle height adjustment device, 4. A vehicle height adjustment device as described in any one of claims 1 to 3, including an arm member that is held at an intermediate portion so as to be rotatable relative to the vehicle body side member, that engages with the wheel side member at one end via an engaging member, and that receives the spring force of the secondary spring at the other end.

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