Vehicle height adjustment device

Abstract

To make improvement of a vehicle height adjusting device, which includes reduction of output of an inclination changing device, for instance.SOLUTION: In a vehicle height adjusting device, one end part of a sub spring or one end part of a link member connected to a third arm is connected to a second arm that is rotated by an actuator, and the other end part of the sub spring or the other end part of the link member is positioned in a turning rang of a shaft line of the actuator. This can make components in a rotation direction of the second arm of force acting on the second arm by the sub spring smaller in comparison with a configuration in which the other end part of the sub spring or the other end part of the link member is positioned out of the turning rang of the shaft line of the actuator, which can reduce loads that are applied to the actuator when increasing a vehicle height and reduce output of an inclination changing device (the actuator).SELECTED DRAWING: Figure 3

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 improve a vehicle height adjusting device, for example, by reducing the output of an inclination changing device. [Means for solving the problem]

[0006] A vehicle height adjusting device according to the present invention can include, for example, (a) a main spring and an auxiliary spring arranged in parallel with each other between a wheel-side member and a vehicle body-side member; (b) a first arm engageable with the wheel-side member; (c) a connecting bar that is rotatably held on the vehicle body-side member around a first axis, which is its own axis, and that rotatably holds the first arm around the first axis; (d) an inclination change device that includes an actuator and a second arm that is rotatably held at one end on a rotation shaft that is an output shaft of the actuator and has the other end connected to one end of the auxiliary spring, and that changes the inclination of the auxiliary spring by rotation of the second arm by the actuator; and (e) a connecting mechanism that connects the inclination change device and the connecting bar in a state that allows relative rotation of the second arm with respect to the connecting bar around the second axis, which is the axis of the rotation shaft of the second arm, and allows integral rotation of the inclination change device and the connecting bar around the first axis, and the other end of the auxiliary spring is held on the vehicle body-side member within a rotation range of the second axis of the actuator.

[0007] The vehicle height adjusting device may include, for example, (1) a main spring and an auxiliary spring provided in parallel with each other between a wheel-side member and a vehicle-body-side member, (2) a first arm engageable with the wheel-side member, (3) a connecting bar that is rotatably held by the vehicle-body-side member around a first axis that is its own axis, and that holds the first arm rotatably around the first axis, and (4) an actuator, and a second arm that is rotatably held at one end by a rotary shaft that is an output shaft of the actuator, and that is connected at the other end to a third arm that is integrally attached to the auxiliary spring so as to be rotatable, and the second arm is rotated by the actuator. (5) a connecting mechanism that connects the tilt change device and the connecting bar in a state that allows relative rotation of the second arm relative to the connecting bar about a second axis that is the axis of the rotation shaft of the second arm and allows integral rotation of the tilt change device and the connecting bar about a first axis, and (i) the auxiliary spring is a torsion bar that is held at one end by a vehicle body side member so as not to be able to rotate relatively, and at the other end, one end of the third arm is held integrally and rotatably, and (ii) the other end of the third arm is connected to the other end of the second arm via a link member, A connecting portion that connects the link member and the other end of the third arm may be located within the range of rotation of the second axis of the actuator.

[0008] In this way, since the tilt change device changes the tilt of the secondary spring or the third arm, the output of the tilt change device can be reduced compared to when changing the tilt of the shock absorber and main spring.

[0009] Furthermore, one end of the auxiliary spring or one end of a link member connected at the other end to the third arm is connected to the second arm rotated by the actuator, and the other end of the auxiliary spring or the other end of the link member is located within the rotation range of the axis of the actuator. This reduces the component of the force acting on the second arm by the auxiliary spring in the direction opposite to the rotation direction of the second arm, compared to when the other end of the auxiliary spring or the other end of the link member is located outside the rotation range of the axis of the actuator. As a result, when the vehicle height is increased, the load applied to the actuator is reduced, and the output of the tilt change device (actuator) can be reduced. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a perspective view conceptually showing a vehicle height control device according to a first embodiment of the present invention. [Figure 2] 4 is a side view showing a main part of the vehicle height adjusting device (when the rotation angle γ is 90°). FIG. [Figure 3] (3A) and (3B) are diagrams showing the rotational component of the force applied to the second arm when the other end of the auxiliary spring is held within the rotational range of the axis of the actuator of the vehicle body member in the vehicle height control device. (3C) and (3D) are diagrams showing the rotational component of the force applied to the second arm when the other end of the auxiliary spring is held in a portion outside the rotational range of the axis of the actuator of the vehicle body member in the vehicle height control device. [Figure 4] FIG. 6 is a plan view of a vehicle height control device according to a second embodiment of the present invention. [Figure 5] FIG. 2 is a side view of the vehicle height adjusting device. [Figure 6](6A) A diagram showing the rotational component of the force applied to the second arm when the connecting portion of the other end of the link member with the torsion bar arm is located within the rotational range of the axis of the actuator in the vehicle height control device. (6B) A diagram showing the rotational component of the force applied to the second arm when the connecting portion of the other end of the link member with the torsion bar arm is located outside the rotational range of the axis of the actuator in the vehicle height control device. [Figure 7] 4 is a diagram showing the relationship between the rotation angle γ of the second arm and the load torque applied to the actuator in the vehicle height control apparatus according to the first embodiment. FIG. [Figure 8] 10 is a diagram showing the relationship between the rotation angle γ of the second arm and the output torque of the actuator in the vehicle height control apparatus according to the second embodiment. FIG. Embodiments of the invention

[0011] 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. As shown in FIG. 1 , the present vehicle height adjusting device can be provided between a wheel-side member 6 including a suspension arm such as a strut-type or double-wishbone-type suspension, and a vehicle-body member 8. The suspension includes a lower arm 10, an upper arm (not shown), a main spring 14, etc. One end of the lower arm 10 is connected to a wheel holding member (not shown) of the wheel 12 via a connecting portion, and the other end is connected to the vehicle-body member 8 so as to be swingable about an axis extending in the longitudinal direction of the vehicle. The main spring 14 is provided in parallel with a shock absorber (not shown) provided between the wheel-side member 6 and the vehicle-body member 8. The axis of the main spring 14 extends generally in the vertical direction. The wheel-side member 6 is formed by the lower arm 10 and the wheel holding member (not shown). Example 1

[0012] The vehicle height adjusting device includes the main spring 14, the secondary spring 16, the first arm 20, the connecting bar 22, the tilt changing device 24, and the like. The secondary spring 16 is a compression coil spring provided in parallel with the main spring 14 between the wheel-side member 6 and the vehicle-body-side member 8. In the secondary spring 16, an elastic force F is generated in the direction in which the secondary spring 16 extends. The first arm 20 is engageable with the lower arm 10 via an engaging member 30. The connecting bar 22 is held by the vehicle body member 8 via a bearing 32 or the like so as to be rotatable about a first axis L, which is the axis of the connecting bar 22. The first arm 20 is held at one end of the connecting bar 22 so as to be rotatable integrally with the first axis L, and an inclination change device 24 is attached to the other end of the connecting bar 22.

[0013] The inclination change device 24 changes the inclination of the secondary spring 16 and includes a housing 34, an actuator 38, a second arm 40, etc. One end of the second arm 40 is held rotatably integrally with a rotation shaft 38r, which is the output shaft of the actuator 38. The second arm 40 is rotated in conjunction with the rotation of the rotation shaft 38r of the actuator 38.

[0014] The housing 34 holds the actuator 38. The housing 34 is generally frame-shaped, and the connecting bar 22 is attached to one of a pair of opposing side surfaces of the housing 34, and the retaining bar 46 is attached to the other of the pair of side surfaces. The retaining bar 46 extends on the same axis as the first axis L, and is held by the vehicle body member 8 via bearings 48 and the like so as to be rotatable about the first axis L. In this way, the housing 34 is held by the connecting bar 22 and the retaining bar 46 so as to be rotatable about the first axis L to the vehicle body member 8.

[0015] As shown in FIG. 2, the secondary spring 16 is held by a pair of retainers 16b, 16c provided on a retaining shaft 16a. The retaining shaft 16a is of a telescopic type and is extendable and contractible. The retainers 16b, 16c are provided at one end and the other end of the retaining shaft 16a, respectively. One end 42 of the secondary spring 16 (one end of the retaining shaft 16a or the retainer 16b) is connected to the other end of the second arm 40 via a connecting portion so that they can rotate relative to each other. The other end 44 of the secondary spring 16 (the other end of the retaining shaft 16a or the retainer 16c) is held by the vehicle body member 8.

[0016] In this way, the secondary spring 16 expands and contracts in accordance with the expansion and contraction of the retaining shaft 16a. The secondary spring 16 is held by the vehicle body side member 8 at the other end 44, and is connected at one end 42 to the wheel side member, which is the lower arm 10, via the second arm 40, the actuator 38, the housing 34, the connecting bar 22, the first arm 20, and the engaging member 30. The secondary spring 16 is provided in parallel with the main spring 14 between the wheel side member and the vehicle body side member.

[0017] The actuator 38 rotates the second arm 40 to change the inclination of the secondary spring 16. The actuator 38 may be an electric motor, or may include an electric motor and a reducer that reduces the rotational speed of the electric motor. A main body 38h of the actuator 38 is fixedly held in the housing 34. A holding portion 38s is provided at the middle portion of the rotation shaft 38r, and one end of the second arm 40 is held by the holding portion 38s so that it can rotate integrally with the rotation shaft 38r. The actuator 38 is mounted such that the holding portion 38s is located on the first axis L of the connecting bar 22, and a second axis La (which is also the axis of the rotation shaft 38r) that is the axis of the actuator 38 intersects with the first axis L of the connecting bar 22 at the holding portion 38s.

[0018] Rotation of the rotation shaft 38r by the actuator 38 rotates the second arm 40 about the second axis La, thereby moving one end 42 of the secondary spring 16 and changing the inclination of the secondary spring 16. The inclination of the secondary spring 16 can be expressed, for example, by a rotation angle γ of the rotation shaft 38r by the actuator 38 (hereinafter, may be abbreviated as the rotation angle γ of the actuator 38 or the rotation angle γ, etc.). In this embodiment, the rotation angle γ is set to 0° when the second arm 40 is positioned on the same line as the first axis L.

[0019] In this embodiment, the connecting bar 22 is attached to the housing 34 that holds the actuator 38, allowing relative rotation of the tilt change device 24, including the housing 34, actuator 38, etc., around the connecting bar 22. For this reason, it can be considered that the housing 34, etc. of the tilt change device 24 constitutes a connecting mechanism. In this embodiment, the connecting mechanism can be considered to be a component of the tilt change device 24.

[0020] In the vehicle height adjusting device configured as described above, the rotation angle γ is changed by the actuator 38, thereby changing the inclination of the secondary spring 16 and changing the load distribution of the secondary spring 16, thereby adjusting the vehicle height. In this vehicle height adjusting device, the inclination of the secondary spring 16 is changed, rather than the inclination of the main spring 14. As a result, the output of the inclination changing device 24 (the output of the actuator 38) can be made smaller than when the inclination of the main spring 14 is changed.

[0021] In addition, in this vehicle height adjusting device, when the second arm 40 is positioned on the first axis L, the moment M generated around the connecting bar 22 by the elastic force of the secondary spring 16 is zero. In contrast, when second arm 40 is rotated about second axis La, a force F is applied to second arm 40 by secondary spring 16 around connecting bar 22, thereby applying moment M shown in FIG. 1. Connecting bar 22 is rotated about first axis L, and a force Fs acts in a direction that pushes lower arm 10 downward via first arm 20 and engaging member 30. In addition, a reaction force Fd from lower arm 10 acts on connecting bar 22, and vehicle height is determined when these moments M and M' are balanced. In this embodiment, the vehicle height when the second arm 40 is positioned on the first axis L (when the rotation angle γ is 0°) is referred to as the low vehicle height as the second vehicle height, and the vehicle height when the second arm 40 is in a position that is approximately perpendicular to the first axis L (when the rotation angle γ is 90°) is referred to as the normal vehicle height as the first vehicle height.

[0022] Furthermore, rotation of the connecting bar 22 about the first axis L rotates the inclination change device 24, thereby rotating the housing 34, the actuator 38, etc. As shown in FIG. 1 , the second axis La(L) at low vehicle height is inclined relative to the second axis La(N) of the actuator 38 at normal vehicle height. In this embodiment, the inclination change device 24 is provided so that the second axis La(N) of the actuator 38 at normal vehicle height extends in a substantially horizontal direction. As a result, when the rotation angle γ of the second arm 40 is 90°, the second arm 40 assumes a substantially vertical position, thereby increasing the moment M generated around the connecting bar 22. In this embodiment, the second axis La(L) of the actuator 38 at low vehicle height is inclined relative to the horizontal plane so that the main body 38h of the actuator 38 is positioned above the horizontal plane.

[0023] In this embodiment, the other end 44 of the secondary spring 16 is held by the vehicle body member 8 within a rotation range A of the second axis La of the actuator 38. The rotation range A of the second axis La of the actuator 38 includes the area between the second axis La(N) and the second axis La(L) and the area on the second axis La(N) and the second axis La(L).

[0024] When raising the vehicle height from low to normal, the force F applied to the second arm 40 by the secondary spring 16 acts in the opposite direction to the rotational direction of the second arm 40. Therefore, the force F applied to the second arm 40 by the secondary spring 16 becomes a load on the actuator 38, and a large output is required when raising the vehicle height from low to normal.

[0025] A hypothetical case where the other end 44 of the secondary spring 16 is held in a portion that is off the second axis La(N) side from the rotation range A of the second axis La of the vehicle body side member 8 will be described with reference to Figures 3C and 3D. 3C, when the rotation angle γ of the second arm 40 is 90°, in rear view (as viewed from the direction of arrow w), the other end 44 of the secondary spring 16 is located on an extension of the second arm 40. Therefore, the component of the force FC acting on the second arm 40 from the secondary spring 16 in the rotation direction of the second arm 40 is very small.

[0026] 3D, when the rotation angle γ of the second arm 40 is 0°, the other end 44 of the secondary spring 16 is located at a position far removed (distance d) from the second axis La (L) in rear view. Furthermore, when the distance d is large, the rotational direction component of the force FD acting on the second arm 40 by the secondary spring 16 is larger than when the distance d is small. The rotational direction component FDr of the force FD is calculated by using the magnitude of the force FD and the angle θd formed between the second arm 40 and the secondary spring 16 in rear view, as follows: FDr=FD*sinθd It can be expressed as:

[0027] Next, a case where the other end 44 of the auxiliary spring 16 is held within the rotation range A of the second axis La of the vehicle body side member 8 will be described with reference to FIGS. 3A and 3B. As shown in FIG. 3B, when the rotation angle of the second arm 40 is 0°, as compared with the case shown in FIG. 3D, in a rear view, the other end 44 is located closer to the second axis La (L). When the other end 44 is located at a distance b from the second axis La (L), the distance b is smaller than the distance d (b < d). Therefore, the angle θb formed by the second arm 40 and the auxiliary spring 16 becomes smaller than the angle θd (θb < θd, sinθb < sinθd), and the rotational direction component FBr of the force FB acting on the second arm 40 becomes smaller as compared with the case shown in FIG. 3D. FBr = FB * sinθb FBr < FDr

[0028] For example, the dashed line in FIG. 7 indicates the load applied to the actuator 38 when the vehicle height is increased from the low vehicle height to the normal vehicle height, when the other end 44 of the auxiliary spring 16 is held by the vehicle body side member 8 at a position outside the rotation range A of the second axis La of the actuator 38 and on the second axis La (N) side of the actuator 38 at the normal vehicle height. Also, the solid line indicates the load applied to the actuator 38 when the vehicle height is increased from the low vehicle height to the normal vehicle height, when the other end of the auxiliary spring 16 is held by the vehicle body side member 8 within the rotation range A of the second axis of the actuator 38. As shown in FIG. 7, it is clear that the load applied to the actuator 38 is smaller when the other end 44 of the auxiliary spring 16 is located within the rotation range A of the second axis of the actuator 38.

[0029] Although not shown in the drawings, it is conceivable that the other end 44 of the auxiliary spring 16 is held at a position outside the rotation range A of the second axis La of the vehicle body side member 8 and on the second axis La (L) side at the low vehicle height. Even in this case, it is possible to reduce the rotational direction component of the force applied to the second arm 40 by the auxiliary spring 16, but another problem occurs in that when the rotation angle γ of the second arm 40 is 90°, the elongation of the auxiliary spring 16 becomes large, the elastic force decreases, and the moment M generated around the first axis L becomes small. On the other hand, the secondary spring 16 can be made large so that a desired amount of elastic force can be obtained when the rotation angle γ of the second arm 40 is 90°. However, in that case, another problem occurs in that the elastic force of the secondary spring 16 becomes too large when the rotation angle γ is 0°.

[0030] From the above, by holding the other end 44 of the secondary spring 16 within the rotation range A of the second axis La of the vehicle body side member 8, it is possible to maintain the force applied to the second arm 40 by the secondary spring 16 at an appropriate magnitude while reducing the rotational component of the force applied to the second arm 40 by the secondary spring 16, thereby reducing the load applied to the actuator 38 and reducing the output of the actuator 38. Example 2

[0031] In the vehicle height control device according to the first embodiment, the secondary spring 16 is a coil spring, but in the vehicle height control device according to the second embodiment, the secondary spring 116 is a torsion bar. 4 and 5, the torsion bar 116 extends in the width direction of the vehicle. The torsion bar 116 is held at both ends by a pair of side frames 108, which serve as vehicle body members spaced apart in the width direction of the vehicle and extending in the front-to-rear direction. One end 118 of the torsion bar 116 is held so as not to rotate relative to the torsion bar 116 about its own axis Lp, and the other end 119 is held so as to rotate relative to the torsion bar 116 about its own axis Lp. One end of a torsion bar arm 150, which serves as a third arm that twists the torsion bar 116, is attached to the other end 119 of the torsion bar 116 so as to rotate integrally with the torsion bar 116.

[0032] Like the vehicle height control device according to the first embodiment, this vehicle height control device includes a main spring (not shown), a torsion bar 116 as a secondary spring, a first arm 120, a connecting bar 122, an inclination change device 124, etc. In the vehicle height control device according to the second embodiment and the vehicle height control device according to the first embodiment, members that perform the same functions as those in the vehicle height control device according to the first embodiment are given reference numerals that are 100 larger than the reference numerals in the vehicle height control device according to the first embodiment, and descriptions thereof may be omitted. The main spring may be, for example, a coil spring provided between a wheel-side member and a vehicle body-side member.

[0033] The tilt change device 124 includes a housing 134, an actuator 138, a second arm 140, a link member 152, etc. One end of the second arm 140 is held by a rotation shaft 138r of the actuator 138 so as to be rotatable integrally with the second arm 140, and the other end is connected to a link member 152. The link member 152 is a rigid body having a certain length. One end of the link member 152 is connected to the other end of the second arm 140, and the other end is connected to a torsion bar arm 150 via a ball joint 154. The torsion bar arm 150 is attached to the torsion bar 116 so as to be rotatable integrally with the torsion bar 116, and the other end is connected to the link member 152 via the ball joint 154.

[0034] The inclination change device 124 rotates the second arm 140 with the actuator 138 to move one end of the link member 152, thereby moving the ball joint 154, thereby changing the inclination of the torsion bar arm 150. By changing the inclination of the torsion bar arm 150 and rotating it, the amount of torsion of the torsion bar 116 can be changed. For this reason, the inclination change device 124 can be called a torsion amount change device.

[0035] A connecting bar 122 and a retaining bar 146 are attached to opposing end surfaces of a housing 134 of the tilt change device 124 so as to be rotatable integrally about a first axis Lq. The connecting bar 122 and the retaining bar 146 are positioned on the same axis Lq and are respectively held by the vehicle body side member 108 via bearings 132, 148 so as to be rotatable about the first axis Lq. The tilt change device 124 is rotatably held around the connecting bar 122 and the retaining bar 146. A first arm 120 is held on the connecting bar 122 so as to be rotatable integrally about the first axis Lq. The first arm 120 is engaged with the lower arm 110 via an engaging member 130.

[0036] In this embodiment, the vehicle height when the rotation angle γ of the second arm 140 is 0° is the low vehicle height, which is the second vehicle height. In this state, the moment acting around the connecting bar 122 is 0. The vehicle height increases as the rotation angle γ of the second arm 140 increases, and the vehicle height when the rotation angle γ is 90° is the normal vehicle height, which is the first vehicle height.

[0037] In this embodiment, when the rotation angle γ is between 0° and 90°, the torsion bar 116 is twisted in the direction of arrow C and generates an elastic force in the direction of arrow D (FIG. 4). When the actuator 138 rotates the second arm 140, one end of the link member 152 is moved, the position of the ball joint 154 changes, and the torsion bar arm 150 rotates around the axis Lp, changing the amount of twist of the torsion bar 116 and the elastic force. Meanwhile, the elastic force of the torsion bar 116 is transmitted to the torsion bar arm 150, the ball joint 154, and the link member 152, and a force Ft is applied to the second arm 140. This generates a moment M around the connecting bar 122, causing the first arm 120 to rotate. When the moment M is large, the downward force Fs acting on the lower arm 10 is larger than when the moment M is small. In response to this, a reaction force Fd is applied from the lower arm 10, and a moment M' is generated around the connecting bar 122. The vehicle height is determined so that the moments M and M' are balanced.

[0038] Further, by the rotation of the connecting bar 122 about the first axis Lq, the tilt change device 124 is also rotated about the first axis Lq, and the second axis Ls which is the axis Ls of the actuator 138 is tilted. In the present Example 2, similar to the case in Example 1, the tilt change device 124 is provided such that the second axis Ls(N) of the actuator 138 at the normal vehicle height extends substantially in the horizontal direction.

[0039] In the present embodiment, the length of the link member 152 and the like are designed such that the ball joint 154 is positioned within the rotation range B of the second axis Ls of the actuator 138. The rotation range B includes between the second axis Ls(N) at the normal vehicle height and the second axis Ls(L) at the low vehicle height, on the second axis Ls(N), and on the second axis Ls(L).

[0040] A case where the ball joint 154 is located outside the rotation range B of the second axis Ls of the actuator 138 on the second axis Ls(N) side at the normal vehicle height will be described based on FIG. 6B. When the rotation angle γ of the second arm 140 is 0°, in a rear view (when viewed from the arrow w), the distance f between the ball joint 154 and the second axis Ls(L) increases, and the rotation direction component Ftbr of the force Ftb applied to the second arm 140 in the rotation direction of the second arm 140 increases. Ftbr = Ftb * sinθ2 Therefore, when raising the vehicle height from the low vehicle height to the normal vehicle height, the rotation direction component Ftr acting in the opposite direction to the rotation direction of the second arm 140 increases, and the load applied to the actuator 138 increases.

[0041] On the other hand, when the ball joint 154 is positioned within the rotation range B of the second axis Ls of the actuator 138, as shown in FIG. 6A, the distance h between the second axis Ls(L) at the low vehicle height and the ball joint 154 in a rear view (when viewed from the arrow w) is smaller (h < f) compared to the case shown in FIG. 6B (f). Therefore, the rotation direction component Ftar in the opposite direction to the rotation direction of the second arm 140 of the force Fta applied to the second arm 140 by the torsion bar 116 becomes smaller. Ftar=Fta*sinθ1 Ftar <Ftbr Therefore, when the vehicle height is increased from low to normal, the rotational direction component Ftr acting in the direction opposite to the rotational direction of the second arm 140 becomes smaller, and the load applied to the actuator 138 becomes smaller.

[0042] For example, the dashed-dotted line in Figure 8 indicates the output torque of actuator 138 when the vehicle height is increased from low to normal when the ball joint 154, which is the connecting portion between link member 152 and torsion bar arm 150, is positioned outside of rotation range B of the second axis Ls of actuator 138 toward the second axis Ls(N) of actuator 138 at the normal vehicle height. The solid line indicates the output torque of actuator 138 when the vehicle height is increased from low to normal when the ball joint 154 at the other end of link member 152 is positioned within rotation range B of the second axis Ls of actuator 138. As shown in Figure 8, it is clear that the output torque of actuator 138 can be reduced when ball joint 154 is positioned within rotation range B of the second axis Ls of actuator 138.

[0043] Furthermore, in the vehicle height control device according to the second embodiment, the torsion bar 116 is twisted by tilting the torsion bar arm 150, rather than tilting the coil spring 16 serving as the secondary spring. Comparing the secondary spring 16 with the link member 152 and the torsion bar arm 150, the link member 152 and the torsion bar arm 150 have a smaller inertia force. As a result, the responsiveness of the actuator 138 can be improved.

[0044] Furthermore, a link member 152, rather than a coil spring, is connected to the second arm 140, but the link member 152 is thinner than a coil spring. This allows for a smaller installation space for the tilt change device, improving the degree of freedom in terms of the installation space for the tilt change device. Furthermore, the torsion bar 116 is easy to install, so installation is less likely to be restricted by the torsion bar 116.

[0045] The relative positions of the sub-spring, actuator, first arm, second arm, etc. are not important and can be changed as appropriate depending on the installation space, etc.

[0046] 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: Wheel side member 8,108: Vehicle body side member 10,110: Lower arm 14: Main spring 16,116: Sub-spring 20,120: First arm 22,122: Connecting bar 24,124: Tilt change device 30,130: Engagement member 34,134: Housing 38,138: Actuator 40,140: Second arm 150: Torsion bar arm 152: Link member 154: Ball joint

Claims

1. 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 first arm engageable with the wheel-side member; a connecting bar that is held by the vehicle body member so as to be rotatable about a first axis line that is an axis line of the connecting bar itself, and that holds the first arm so as to be rotatable about the first axis line; an inclination change device including an actuator and a second arm rotatably held at one end by a rotation shaft that is an output shaft of the actuator and connected at the other end to a third arm attached to the secondary spring, the inclination change device changing the inclination of the third arm by rotation of the second arm by the actuator; a coupling mechanism that couples the inclination change device and the connecting bar in a state that allows relative rotation of the second arm with respect to the connecting bar about a second axis that is an axis of the rotation shaft, and allows integral rotation of the inclination change device and the connecting bar about the first axis, the secondary spring is a torsion bar having one end held by the vehicle body member so as not to be rotatable relative to the vehicle body member around its own axis, and having the other end to which one end of the third arm is attached so as to be integrally rotatable, the other end of the third arm is connected to the other end of the second arm via a link member, a connecting portion that connects the link member and the other end of the third arm is located within a range of rotation of the second axis of the actuator about the first axis;

2. one end of the link member is connected to the other end of the second arm, 2. The vehicle height adjusting device according to claim 1, wherein the other end of the link member is connected to the other end of the third arm via a ball joint as the connecting portion.

3. 3. The vehicle height adjustment device according to claim 1, wherein the axis of the actuator is positioned in a horizontal plane when the vehicle height is a first vehicle height, and the tilt change device is held by the vehicle body side member in a state in which the axis of the actuator is tilted relative to the horizontal plane when the vehicle height is a second vehicle height lower than the first vehicle height.

4. A main spring and a sub-spring arranged in parallel with each other between the wheel side member and the vehicle body side member; a first arm engageable with the wheel-side member; a connecting bar that is held by the vehicle body member so as to be rotatable about a first axis line that is an axis line of the connecting bar itself, and that holds the first arm so as to be rotatable about the first axis line; an inclination change device including an actuator and a second arm rotatably held at one end on a rotation shaft that is an output shaft of the actuator and having one end of the secondary spring connected at the other end, the inclination change device changing the inclination of the secondary spring by rotation of the second arm by the actuator; a coupling mechanism that couples the inclination change device and the connecting bar in a state that allows relative rotation of the second arm with respect to the connecting bar about a second axis that is an axis of the rotation shaft, and allows integral rotation of the inclination change device and the connecting bar about the first axis, the other end of the auxiliary spring is held by the vehicle body side member within a rotation range of the second axis of the actuator of the vehicle body side member about the first axis, A vehicle height adjustment device in which the axis of the actuator is located in a horizontal plane when the vehicle height is a first vehicle height, and the tilt change device is held by the vehicle body side member in a state in which the axis of the actuator is tilted relative to the horizontal plane when the vehicle height is a second vehicle height lower than the first vehicle height.

Images