Vehicle height adjusting device

Abstract: A vehicle height adjusting device includes a resilient member (11) having an outer end (A) coupled to a wheel support member (3) and an inner end (B) supported on a vehicle body (9), the resilient member (11) having a vertical resilient force and serving as a suspension component, and a load unit disposed between the resilient member (11) and the vehicle body (9) for applying a vertical bending stress to the resilient member (11) to displace the resilient member (11) for thereby varying the height of the vehicle body (9). Another vehicle height adjusting device includes an elongate resilient member (13) extending transversely of a vehicle body (9) and having opposite ends (A) coupled respectively to two laterally spaced wheel support members (3), the resilient member (13) having a vertical resilient force and serving as a suspension component, retaining members (21) supporting an intermediate portion (t₁) of the elongate resilient member (13) slidably and swingably on the vehicle body (9) at at least two spaced points (C) on the intermediate portion (t₁), and a load unit for applying a vertical bending stress to the resilient member (13) to displace the resilient member for thereby varying the height of the vehicle body (9).

Description: The present invention relates to a vehicle height adjusting device as described in the preamble part of claim 1. Such a vehicle height adjusting device e.g. is known from DE-A-25 41 841. In the vehicle height adjusting device according to this disclosure an elongate resilient member extending transversely of the vehicle body has opposite ends respectively coupled to two laterally spaced wheel support members and is vertically resilient and serves as a suspension element. The elongate resilient member is supported by retaining means at an intermediate portion thereof at at least two points laterally spaced apart from each other. A load means is provided for applying a load on the elongate resilient member in a vertical direction and in a substantially central portion thereof in order to adjust the height of the vehicle. This vehicle height adjusting device, however, is not able to independently adjust the height of both the right and left road wheels of the vehicle for thereby adjusting the attitude of the vehicle e.g. when turning a curve. Further known conventional vehicle height adjusting devices include a damper comprising a shock absorber which has an additional air chamber serving as an actuator for effecting vehicle height adjustment and also comprising a coil spring. Laterally spaced suspensions have such dampers independently. Such a height adjusting device is disclosed in Japanese Laid-Open Patent Publication No. 61-150809, for example It is an object of the present invention to provide a vehicle height adjusting device which is capable of indepently adjusting the height of the vehicle at both sides thereof. This object is solved by a vehicle height adjusting device according to the preamble part of claim 1, in which the load means includes means for applying different loads to two points laterally spaced apart on the elongate resilient member between said supporting points. Preferred embodiments of the invention are described in the subclaims. The above and further objects, details and advantages of the present invention will become apparent from the following detailed description of preferred embodiments thereof, when read in conjunction with the accompanying drawings. FIG. 1 is a schematic front elevational view of a suspension incorporating a vehicle height adjusting device; FIG. 2 is a schematic front elevational view of a suspension incorporating a vehicle height adjusting device; FIG. 3 is a schematic front elevational view of two laterally spaced suspensions incorporating a vehicle height adjusting device; FIG. 4 is a schematic front elevational view of two laterally spaced suspensions incorporating a vehicle height adjusting device; FIG. 5 is a schematic front elevational view showing the manner in which a concentrated load is appiled to the center of a resilient member by a load means; FIG. 6 is a schematic front elevational view showing the manner in which different concentrated loads are appiled at two spaced positions to an intermediate portion of a resilient member by a load means according to the present invention. Fig. 1 to 5 do not show embodiments of the present invention but refer to examples which are particularly useful for understanding the present invention. FIG. 1 shows a vehicle suspension incorporating a vehicle height adjusting device. The suspension shown together with one of laterally spaced road wheels is of the double-wishbone type. A road wheel 1 is rotatably supported on an axle 2 mounted on a support member or knuckle 3 pivotally connected at an upper end thereof to the outer end of an upper arm 4 of the suspension. The suspension also includes a lower arm which is constructed of a resilient member or leaf spring 11 having a vertical resilient force and extending transversely of the vehicle. More specifically, the leaf spring 11 has a slightly upwardly curved intermediate portion of an arcuate shape. The outer end of the leaf spring 11 is pivotally connected to the lower end of the knuckle 3 at a supporting point A. The leaf spring 11 has its inner end fixedly supported on a vehicle body 9 at a supporting point B. Although not shown in FIG. 1, a load means of any desired type is interposed between the vehicle body 9 and the intermediate portion of the leaf spring 11, and a damper comprising a shock absorber only is associated with the suspension. Since the lower arm, which cooperates with the upper arm 4 in constructing the double-wishbone suspension, is constructed of the leaf spring 11, the portion of the suspension pivotally coupled to the leaf spring 11 at the outer supporting point A near the road wheel 1 is normally urged downwardly under the resiliency of the arcuate leaf spring 11 which is supported on the vehicle body 9 at the inner supporting point B. Therefore, as the leaf spring 11 doubles as the lower arm, the suspension is made lightweight. The suspension can also employ dampers each comprising a shock absorber only with no coil spring. When an upward bending stress, for example, is applied to the leaf spring 11 at a portion or in a certain range thereof by the load means, as indicated by the arrow F, the leaf spring 11 fixed to the vehicle body 9 at the inner supporting point B is elastically deformed, lifting its outer supporting point A, i.e., moving the road wheel 1 upwardly with respect to the vehicle body 9. The vehicle height above ground is thus lowered. Conversely, the vehicle height above ground is increased by applying a downward bending stress to the leaf spring 11. FIG. 2 shows a second example in which a lower arm 5 has an outer end pivotally coupled to the lower end of a knuckle 3 and a leaf spring 12 is provided separately from the lower arm 5. The leaf spring 12 has an outer end pivotally coupled to an intermediate portion of the lower arm 5 at a supporting point A and an inner end fixedly supported on a vehicle body 9 at a supporting point B. The arrangement shown in FIG. 2 operates in the same manner and offers the same advantages as the construction shown in FIG. 1, except that the leaf spring doubles as the lower arm in FIG. 1. According to a third example shown in FIG. 3, two laterally spaced suspensions each identical to that of the first embodiment are interconnected by a leaf spring 13 which is elongate transversely of the vehicle. The leaf spring 13 is of an arcuate shape with its intermediate portion curved upwardly, and is longer than the leaf springs 11, 12 shown in FIGS. 1 and 2. The opposite ends of the leaf spring 13 are pivotally coupled at supporting points A to the lower ends of laterally spaced knuckles or support members 3 supporting road wheels 1, respectively, through axles 2. The leaf spring 13 has its intermediate portion slidably and swingably supported on a vehicle body 9 at two laterally spaced supporting points C by means of retaining members 21, respectively. The leaf spring 13 doubles as two lower arms. Although not shown, a load means of any desired type is interposed between the vehicle body 9 and a central area, for example, of the intermediate portion of the leaf spring 11 between the supporting points C, and a damper comprising a shock absorber only is associated with each of the suspensions. Since the lower arms 5 are constructed of the common leaf spring 13, the portions of the suspensions pivotally coupled to the leaf spring 13 at supporting points A on the opposite ends of the leaf spring 13 near the road wheels 1 are normally urged downwardly under the resiliency of the arcuate leaf spring 13 which is supported on the vehicle body 9 at the two laterally spaced supporting points C on the intermediate portion of the leaf spring 13, with the load means interposed between the leaf spring 13 and the vehicle body 9 between the supporting points C. Therefore, the common leaf spring 13 doubling as the lower arms gives the suspensions a stabilizer function, the load means is shared by the suspensions, and the suspensions are made lightweight. The suspensions can also employ dampers each comprising a shock absorber only with no coil spring. When an upward bending stress, for example, is applied to the leaf spring 13 at its center or within a certain intermediate range L between the supporting points C by the load means, as indicated by the arrow F, the leaf spring 13 is elastically deformed, lifting its intermediate portion. The supporting points A on the opposite ends of the leaf spring 13 near the road wheels 1 are then lowered about the supporting points C, so that the road wheels 1 are moved downwardly with respect to the vehicle body 9, resulting in an increase in the vehicle height above ground. Conversely, when a downward bending stress is imposed on the intermediate portion of the leaf spring 11, the vehicle height above ground is reduced. FIG. 4 shows a fourth example in which two laterally spaced suspensions each identical to that of the second embodiment are interconnected by a leaf spring 14 which is elongate transversely of a vehicle. More specifically, the elongate leaf spring 14, which is separate from two laterally spaced lower arms 5, has opposite ends pivotally coupled at supporting points A to intermediate portions of the lower arms 5, respectively. The leaf spring 14 has an intermediate portion slidably and swingably supported on a vehicle body 9 at two laterally spaced supporting points C by means of retaining members 21, respectively. The arrangement shown in FIG. 4 operates in the same manner and offers the same advantages as the construction shown in FIG. 3, except that the leaf spring doubles as the lower arms in FIG. 3. In the third and fourth examples, the elongate leaf springs 13, 14 are employed and a vertical bending stress is applied by the load means to a limited range L of the intermediate portion of the leaf springs 13, 14. Therefore, the supporting points A near the road wheels 1 can be displaced a relatively large distance by a relatively small vertical displacement of the intermediate range L. Inasmuch as the load means is disposed between the supporting points C on both sides of the intermediate portion of the leaf springs 13, 14, height adjusting actuators are not required to be associated independently with the road wheels 1 but the load means is located in a centralized position. This allows the suspensions to be smaller and lighter. The leaf spring 13, 14 may be subjected to a centralized load F applied to the center of the leaf spring 13, 14, as shown in FIG. 5. However, according to the present invention independent vehicle height adjustments may be effected at the laterally spaced road wheels 1 by applying different centralized loads F, F' to two laterally spaced points on the leaf spring 13, 14 between the supporting points B, as shown in FIG. 6.

Claims: A vehicle height adjusting device comprising: an elongate resilient member (13;14) extending transversely of a vehicle body (9) and having opposite ends coupled respectively to two laterally spaced wheel support members (3), said resilient member (13;14) having a vertically resilient characteristic and serving as a suspension component; retaining means (21) supporting an intermediate portion of said elongate resilient member (13;14) slidably and swingably on said vehicle body (9) at at least two spaced points (C) on said intermediate portion; load means (31) for applying a vertical bending force to said resilient member (13;14) to displace the resilient member (13;14) for thereby varying the height of the vehicle body (9), characterized in that said load means includes means for applying different concentrated loads (F,F') to two laterally spaced points on said elongate resilient member (13, 14) between said supporting points (C). A vehicle height adjusting device according to claim 1, further including upper arms (4) having outer ends pivotally coupled to upper portions of said wheel support members (3), respectively, said opposite ends of said resilient member (13) being pivotally coupled respectively to lower portions of said wheel support members (3), said resilient member (13) cooperating with said upper arms (4) in providing double-wishbone suspensions. A vehicle height adjusting device according to claim 1, further including upper arms (4) having outer ends pivotally coupled to upper portions of said wheel support members (3), respectively, and lower arms (5) having outer ends pivotally coupled to lower portions of said wheel support members (3), respectively, said opposite ends of said resilient member (14) being pivotally coupled respectively to said lower arms (5), said lower arms (5) cooperating with said upper arms (4) and said wheel support members (3) in providing double-wishbone suspensions. A vehicle height adjusting device according to claim 1, wherein said resilient member (13;14) comprises an upwardly curved arcuate leaf spring extending transversely of said vehicle body (9) for normally urging downwardly said wheel support members (3) coupled to the opposite ends of the resilient member (13;14).

Inventors: KAJIWARA HAJIME C O HONDA R D, OGURA MASAMI C O HONDA R D CO, SANO SHOICHI C O HONDA R D CO, KAJIWARA, HAJIME, C/O HONDA R & D CO., LTD., OGURA, MASAMI, C/O HONDA R & D CO., LTD., SANO, SHOICHI, C/O HONDA R & D CO., LTD., Kajiwara, Hajime, c/o Honda R &amp; D Co., Ltd., Ogura, Masami, c/o Honda R &amp; D Co., Ltd., Sano, Shoichi, c/o Honda R &amp; D Co., Ltd.
Applicants: HONDA MOTOR CO LTD, HONDA GIKEN KOGYO KABUSHIKI KAISHA
Application year: 1988
Main classification: B60G17
IPC codes: B60G11, B60G17