JPH05155225A - Height adjusting device with torsion bar for vehicle - Google Patents

Abstract

(57) [Summary] [Purpose] To adjust the vehicle height without changing the spring constant of the torsion bar and to improve the mountability on the vehicle. [Structure] A first torsion bar 10 connected to a suspension arm 14 at one end and twisted around an axis 10a according to the pivot movement thereof, and a second torsion bar 12 fixed to a vehicle body 18 at one end are provided. The other ends of these torsion bars are connected by a differential gear device 28. The ring gear 36 of the differential gear device is rotated about an axis by an actuator 48, and the side gears 44 and 46 fixed to the other ends of the two torsion bars are relatively rotated via a pair of transmission pinion gears 40 and 42. The vehicle height is adjusted by.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle height adjusting device for a vehicle such as an automobile, and more particularly to a vehicle height adjusting device for a vehicle having a torsion bar.

[0002]

2. Description of the Related Art As one of vehicle height adjusting devices equipped with a torsion bar, for example, as disclosed in Japanese Utility Model Laid-Open No. 2-68205, one end is connected to a suspension arm and the other end is fixed. An anchor arm for vehicle height adjustment provided in the middle of a torsion bar fixed to the vehicle body by an anchor arm, and an actuator connected to the tip of the anchor arm for vehicle height adjustment to pivot the anchor arm around the axis of the torsion bar. Conventionally, a vehicle height adjusting device having the following is known.

Further, as one of vehicle height adjusting devices for vehicles equipped with a torsion bar, for example, as disclosed in Japanese Utility Model Laid-Open No. 63-58010, a torsion bar connected at one end to a suspension arm, and others. 2. Description of the Related Art A vehicle height adjusting device having an anchor arm fixed to an end and an actuator provided between a tip end of the anchor arm and a vehicle body for pivoting the anchor arm around an axis of a torsion bar is conventionally known.

According to the former vehicle height adjusting device described above, the vehicle height adjusting anchor arm is pivoted about the axis of the torsion bar by the actuator to form the vehicle height adjusting anchor arm around the axis of the torsion bar. By changing the relative rotation angle between the suspension arm and the latter vehicle height adjusting device described above, the actuator causes the anchor arm to pivot about the axis of the torsion bar, so that the axis of the torsion bar moves. The vehicle height can be increased or decreased by changing the relative rotation angle between the surrounding anchor arm and the suspension arm.

[0005]

However, in the former vehicle height adjusting device described above, when the vehicle height is increased or decreased, a portion of the torsion bar between the vehicle height adjusting anchor arm and the suspension arm. Only the torsion bar will function as a torsion bar, so the spring constant of the torsion bar will be higher when the vehicle height is adjusted from the normal state, and conversely the spring constant will be lower when the vehicle is returned to the normal state from the vehicle height adjusted state. Therefore, it is difficult to adjust the vehicle height without adversely affecting the steering stability and riding comfort of the vehicle.

Further, in the former vehicle height adjusting device described above,
When the suspension arm pivots and the torsion bar is twisted by the wheel bouncing and rebounding in the normal state where the vehicle height is not adjusted, the vehicle height adjusting anchor arm also moves around the axis of the torsion bar. As it pivots, the actuator must, under normal conditions, allow free pivoting of the vehicle height adjusting anchor arm, thus complicating the structure.

On the other hand, in the latter vehicle height adjusting device described above,
Since the anchor arm is always fixed to the other end of the torsion bar, it is unavoidable to place an actuator that rotates and drives the anchor arm in the vicinity when adjusting the vehicle height. There is a problem that is.

Further, in any of the vehicle height adjusting devices described above,
Since the anchor arm pivots around the axis of the torsion bar during vehicle height adjustment, the anchor arm easily interferes with other parts of the vehicle, which also limits the vehicle on which the above vehicle height adjusting device can be mounted. There is a problem that is.

In view of the above-mentioned problems in the conventional vehicle height adjusting device for a vehicle having a torsion bar, the present invention can adjust the vehicle height without causing a change in the spring constant of the torsion bar, and An object of the present invention is to provide a vehicle height adjusting device which is excellent in mountability on a vehicle.

[0010]

According to the present invention, there is provided a vehicle height adjusting device having a torsion bar, and a suspension arm pivotally supported on a vehicle body.
A first torsion bar connected to the suspension arm at one end and twisted around its own axis as the suspension arm pivots; and one end fixed to the vehicle body and extending substantially along the axis. A second torsion bar, a differential gear device that connects the other ends of the first and second torsion bars, and an actuator that rotates the differential gear device around the axis, The differential gear device includes a ring that is rotationally driven around the axis by the actuator, a pair of transmission pinion gears that are arranged to face each other on both sides of the axis and rotatably supported by the ring, and A first side gear fixed to the other end of the one torsion bar and meshing with the pair of transmission pinion gears; Is accomplished by a vehicle height adjustment device and a second side gear to second is fixed to the other end of the torsion bar meshing with the pair of transmission pinion.

[0011]

According to the above-described structure, when the suspension arm pivots due to the wheel bouncing and rebounding, the first torsion bar is twisted about its axis and the other end of the first torsion bar is The rotation is transmitted to the other end of the second torsion bar as a reverse rotation by the differential gear device and the second torsion bar is twisted in the opposite direction, so that the first and second torsion bars are as if they were one. It functions as a torsion bar and acts as a suspension spring.

Further, when the ring of the differential gear device is rotated about the axis by the actuator, the pair of transmission pinion gears rotatably supported by the ring revolves around the axis while rotating around the first and second transmission pinion gears. A relative rotation angle occurs between the other ends of the two torsion bars. Therefore, when the relative rotation angle is increased, the relative rotation angle of the suspension arm with respect to the vehicle body is increased to increase the vehicle height, and conversely, the relative rotation angle between the other ends of the first and second torsion bars is reduced. Then, the relative rotation angle of the suspension arm with respect to the vehicle body decreases and the vehicle height decreases. Therefore, the vehicle height can be increased or decreased by rotating the ring of the differential gear device by the actuator.

In this case, since the load of the vehicle body acting on the suspension arm does not change even if the vehicle height is adjusted, the torsion amounts of the first and second torsion bars are invariable, and the first and second torsion bars have the same twisting amount. Both function as torsion bars as they are, and therefore the spring constant as a whole is unchanged.

Further, according to the above-mentioned structure, the thicknesses of the first and second torsion bars and their constituent materials can be set relatively freely by appropriately selecting the constituent materials. The position of the gear gear device and the actuator for rotationally driving the same can be set relatively freely, and the anchor arm does not pivot even when the vehicle height is adjusted. Therefore, compared with the two vehicle height adjustment devices described above, the vehicle It is possible to improve the mountability for.

[0015]

Embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

FIG. 1 is a perspective view showing an embodiment of a vehicle height adjusting device according to the present invention, and FIG. 2 is a schematic plan view showing the embodiment shown in FIG.

In FIG. 1, reference numerals 10 and 12 denote first and second torsion bars, respectively. The first torsion bar 10 is connected to the suspension arm 14 at one end, and the second torsion bar 12 is fixed to the frame 18 of the vehicle body by an anchor arm 16 at one end. In the illustrated embodiment, the first and second torsion bars extend in the longitudinal direction of the vehicle and their axes 10a and 10b are substantially aligned with each other.

In the illustrated embodiment, the suspension arm 14 has an outer end rotatably supporting a wheel via a carrier and two inner ends pivotally supported by the vehicle body, which are not shown in the drawing. It is an A-shaped arm having. The two inner ends are provided with rubber bush devices 22 and 24 that extend along the axis 20 substantially aligned with the axis 10a and are spaced from each other, and one end of the first torsion bar 10 has a rubber bush. It is connected and fixed to the outer cylinder of the device 22 by serration engagement. Although not shown in detail in the drawing, the outer cylinders of the rubber bush devices 22 and 24 are the suspension arm 1
The inner cylinder is fixed to the inner end of No. 4 and is supported by a vehicle body (not shown) by a support bracket 26 disposed between the two rubber bush devices. Therefore, when a wheel (not shown) bounces or rebounds, the suspension arm pivots around the axis 20 and, accordingly, the first torsion bar 10 twists around its own axis 10a. ..

As shown in the figure, a differential gear device 28 is provided between the first and second torsion bars. The differential gear device has a housing 30, and a drive pinion gear 34 is fixed to one end of a drive shaft 32 extending through the housing. The drive pinion gear 34 meshes with a ring gear 36, and a frame 38 is integrally connected to the ring gear 36.
The frame 38 includes a pair of transmission pinion gears 40 and 42 arranged on both sides of the axes 10a and 12a so as to face each other.
Of the torsion bar 10 and the shaft of the torsion bar 10 are rotatably supported about an axis perpendicular to the axes 10a and 12a.
The other end of 2 is rotatably supported around each axis 10a, 12a. Side gears 44 and 46 are fixed to the other ends of the torsion bars 10 and 12, respectively, and these side gears are the transmission pinion gears 40 and 4.
It meshes with 2.

The other end of the drive shaft 32 is drivingly connected to an actuator 48, whereby the drive shaft 32 is predetermined by the actuator 48 in response to a control signal from a control device (not shown) during vehicle height adjustment. Is selectively driven to rotate in a predetermined direction, and is held in a non-rotating state when the vehicle height is not adjusted. The actuator 48 can selectively drive the drive shaft 32 in any direction by a predetermined amount during vehicle height adjustment, and may have any structure as long as it can prevent rotation of the drive shaft during normal operation. It may be an electric motor, a hydraulic motor, a hydraulic cylinder device having a motion converting mechanism such as a crank, or the like.

In FIG. 3, the suspension arm 14 has an axis 2
4 is an explanatory view showing the operation of the differential gear device 28 when it is pivoted around 0, and the thick arrows and the thin arrows in FIG. 3 respectively indicate that the suspension arm pivots in the wheel bounding direction and the wheel rebounding direction. The rotation direction in this case is shown.

As can be seen from FIG. 3, the other ends of the first and second torsion bars rotate in opposite directions by the same amount when the suspension arm pivots in either the bounding direction or the rebounding direction of the wheel. As a result, the torsion angles of the first and second torsion bars increase and decrease, and the spring force generated by the first and second torsion bars increases when the wheel bounces and decreases when the wheel rebounds.

Even when the suspension arm is in the neutral position, the suspension arm is pivoted in the wheel bound direction as compared with the case where the vehicle body load is not applied to the suspension arm. The second torsion bars are twisted in opposite directions.

FIGS. 4A and 4B are explanatory views showing the operation of the differential gear device 28 before and after the vehicle height adjustment, respectively. In FIG. 4, the side gears 44 and 46 are replaced with racks 44 'and 46', respectively, as in the case of the operation of the differential gear device used in the rear wheel drive system of an automobile. Pinion gear 5 that meshes with the rack
Reference numeral 0 corresponds to the transmission pinine gears 40 and 42.

The meshing point between the racks 44 'and 46' and the pinion gear 50 before the vehicle height is adjusted is shown in FIG.
It is indicated by ▲ in (a), and from this state, the drive pinion gear 34 moves through the drive shaft 32 to the actuator 4
When rotated by 8, the ring gear 36 rotates about the axes 10a and 12a, and the transmission pinion gears 40 and 4 are rotated.
2 revolves around these axes while revolving around its axis. Since one end of the second torsion bar 12 is fixed to the vehicle body 18, the rotation resistance of the side gear 46 is larger than the rotation resistance of the side gear 44. Therefore, as shown in FIG. 4 (b), the pinion gear 50 rotationally moves relative to the racks 46 ', and the racks 44' are accordingly driven relative to the racks 46 ', and the racks 44' are driven. Pinion gear 5
The meshing position with 0 changes to the position indicated by Δ in FIG. 4 (b). The distance D between the meshing positions before vehicle height adjustment in FIG. 4B is twice the moving distance d of the pinion gear 50, which corresponds to the relative rotation angle of the side gears 44 and 46 about the axes.

Thus, the side gears 44 and 46 can be relatively rotated in opposite directions by rotating the ring gear. However, when the vehicle height is adjusted to be increased, the relative rotation angle of the side gear 44 with respect to the side gear 46 is set to the wheel. When adjusting in the bounce direction and reducing the vehicle height, this relative rotation angle must be adjusted in the wheel rebound direction. Therefore, in the illustrated embodiment, when increasing the vehicle height, the drive shaft 32 is set to the actuator 48.
2 is driven to rotate in the direction indicated by the solid arrow in FIG. 2, and conversely, when the vehicle height is reduced and adjusted, the drive shaft 32 is moved in the direction indicated by the dashed arrow in FIG. Drive in rotation.

The angle between the anchor arm 16 and the suspension arm when the vehicle body load is not acting on the suspension arm 14 is θs, and the first and second torsion bars when the wheels are in the neutral position. Assuming that the twist angles of θ1 and θ2 are respectively and the relative rotation angle θd between the other ends of the first and second torsion bars is 0, the first and second torsion bars are twisted in opposite directions as described above. Therefore, the angle θt between the anchor arm and the suspension arm when the vehicle height is not adjusted
Is expressed as θt = θs + θ1−θ2.

When the suspension arm pivots due to the wheel bouncing and rebounding, the first torsion bar 10 is twisted around its axis and the rotation of the other end of the first torsion bar causes the differential gear device to rotate. Since the second torsion bar is twisted in the opposite direction by being transmitted to the other end of the second torsion bar 12 as a rotation in the opposite direction by 28, the first and second torsion bars function as if they were one torsion bar. When the wheels bounce, the angles θ1 and θ2 increase and the spring force increases, while when the wheels rebound, the angles θ1 and θ2 decrease and the spring force decreases.

When the ring gear 36 of the differential gear device 28 is rotated around the axis by the actuator 48 via the drive shaft 32 and the drive pinion gear 34 to adjust the vehicle height, the ring gear 36 is rotatably supported by the frame 38. The pair of transmission pinion gears 40 and 42 revolve around the axis while rotating, and a relative rotation angle θd is generated between the other ends of the first and second torsion bars. Therefore, the angle θt between the anchor arm and the suspension arm in this case is represented by θt = θs + θ1−θ2 + θd.

As can be seen from this equation, when the relative rotation angle θd is positive, the vehicle height increases by increasing the angle θt, and conversely, when the relative rotation angle θd is negative, the vehicle height decreases by decreasing the angle θt. Therefore, the vehicle height can be increased or decreased by increasing or decreasing the relative rotation angle θd by rotating the ring gear of the differential gear device as described above. In this case, the angles θ1 and θ2 do not change even if the relative rotation angle θd is increased or decreased.
Even if the vehicle height is adjusted to increase or decrease, both the first and second torsion bars function as the torsion bar as they are, and the spring constant as a whole does not change.

The anchor arm 16 remains stationary and does not pivot about the axis of the torsion bar before and after vehicle height adjustment, so that the anchor arm does not interfere with other parts of the vehicle.

Although the present invention has been described in detail with reference to specific embodiments, the present invention is not limited to these embodiments, and various other embodiments within the scope of the present invention. It will be apparent to those skilled in the art that

For example, in the illustrated embodiment, the ring gear 36 of the differential gear unit 28 is driven to rotate by the drive pinion gear 34 fixed to the drive shaft 32, but the drive of the rotary actuator. It may be rotationally driven by a worm gear that is fixed to the shaft and meshes with the ring gear.
The frame may be rotationally driven by a connecting rod pivotally attached to the reciprocating actuator at one end and pivotally attached to the outer circumference of the ring at the other end.

[0034]

As is apparent from the above description, according to the present invention, the ring of the differential gear device is rotated around the axis by the actuator and the ring between the other ends of the first and second torsion bars is rotated. The vehicle height can be increased or decreased by increasing or decreasing the relative rotation angle of. In this case, even if the vehicle height is adjusted, the load on the vehicle body that acts on the suspension arm does not change, the amount of twist of the first and second torsion bars does not change, and both the first and second torsion bars do not change their torsion. Since it functions as a bar,
The vehicle height can be adjusted without changing the spring constant.

Further, according to the present invention, the lengths of the first and second torsion bars and the constituent materials thereof can be set relatively freely by appropriately selecting the constituent materials, so that the differential gear can be set. Since the position of the device and the actuator for driving the device to rotate can be set relatively freely, and the anchor arm does not pivot even when adjusting the vehicle height, it is mounted on the vehicle as compared with the above two vehicle height adjusting devices. It is possible to improve the sex.

[Brief description of drawings]

FIG. 1 is a perspective view showing one embodiment of a vehicle height adjusting device according to the present invention.

FIG. 2 is a schematic plan view showing the embodiment shown in FIG.

FIG. 3 is an explanatory view showing the operation of the differential gear device when the suspension arm pivots around the axis.

FIG. 4 is an explanatory diagram showing the operation of the differential gear device in a state before vehicle height adjustment (a) and a state after vehicle height adjustment (b).

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... 1st torsion bar 12 ... 2nd torsion bar 14 ... Suspension arm 16 ... Anchor arm 18 ... Frame 28 ... Differential gear device 32 ... Drive shaft 34 ... Drive pinion gear 36 ... Ring gear 40, 42 ... Transmission pinion gear 44, 46 … Side gear 48… Actuator

Claims (1)

[Claims] 1. A vehicle height adjusting device having a torsion bar, wherein a suspension arm pivotally supported on the vehicle body is provided.
A first torsion bar connected to the suspension arm at one end and twisted around its own axis as the suspension arm pivots; and one end fixed to the vehicle body and extending substantially along the axis. A second torsion bar, a differential gear device that connects the other ends of the first and second torsion bars, and an actuator that rotates the differential gear device around the axis, The differential gear device includes a ring that is rotationally driven around the axis by the actuator, a pair of transmission pinion gears that are arranged to face each other on both sides of the axis and rotatably supported by the ring, and A first side gear fixed to the other end of the one torsion bar and meshing with the pair of transmission pinion gears; Vehicle height adjusting device having a second side gear of said pair of transmission pinion meshing is fixed to the other end of the second torsion bar.