GB2301324A

GB2301324A - Suspension system for automobile

Info

Publication number: GB2301324A
Application number: GB9617294A
Authority: GB
Inventors: Hiroshi Maeda; Akihiko Sakazaki
Original assignee: Fuji Jukogyo KK; Yorozu Corp; Yorozu Jidosha Kogyo KK; Fuji Heavy Industries Ltd
Current assignee: Subaru Corp; Yorozu Corp
Priority date: 1992-08-19
Filing date: 1993-08-13
Publication date: 1996-12-04
Anticipated expiration: 2013-08-13
Also published as: GB2301323A; GB9617233D0; GB2301322A; GB2301323B; GB2301322B; GB9617294D0; GB9617234D0; GB2294668B; GB2294668A; GB2294668A8; GB9600353D0; GB2301324B

Description

1 SUSPENSION S'.7STEM FOR AUTOMOBILE 2301324 he present invention relates

to a suspension system for an automobile, in particular, to a suspension system for an automobile having a torsion bar.

japanese Utility Model Publication No. 61-27287 10 dsc-icses a suspension system having a tcrsicn bar which is twisted to urge a suspens-on arm when a load is ar)r)lied to t-he arm in a substantially vertical direction o an au t-omobile body, and which is allowed to move in a substantially front to rear or longitudinal direction of the body. This related art reference will hereinafter be zefe-.-.-ed to as the first related art reference. In 'this front suspension system, a front end of the torsion bar is mounted at the center of the rotation of a lower arm. In addition, a cross member is provided with a proximal end of an anchor arm which is made of a spring plate and extends in a substantially lateral direction of the body.

The rear end of the torsion bar is fixed to a distal end of the anchor arm. Thus, when a load is appiied to the suspension system in the substantially front to rear directon of the body, the anchor arm made of the spring plate"elastically deforms, thereby moving the torsion bar and the lower arm in the substantially longitudinal direction of the body. Therefore, the riding comfort of the automobile is improved.

When a load is applied to the suspension system of this type, it is necessary to prevent the rear end of the torsion bar from directly contacting the cross member.

Otherwise, the load will be transmitted from the torsion bar to the automobile body through the cross member.

Thus, the riding comfort will be degraded. Therefore, in the suspension system disclosed in the first related art reference, the rear end of the torsion bar is provided 1 BAD ORIGINAL L -59).

9 2 with a rubber bushing so as to prevent the torsion bar -he cross member.

from directly con'.

Eowever, when a load is applied to the suspension system in the substantially -longitudinal direction of the body, a large reaction force takes place on the rubber bushing and thereby the rubber bushing isexcessively worn. Therefore, the rubber bushing should have high durability. Nevertheless, if the rubber bushing is made of relatively hard rubber, the durability may be -.n e satisfied. Eowever, the load will be transmit 'L to L body through the rubber bushing and the cross member, thereby degrading the riding comfort.

Ano ther suspension system, which is allowed to move tudinal direction of the body in' the substantially longit is disclosed in japanese Patent Application Laid-Open No. 57-110514. This related art reference will hereinafter be referred to as the second this front suspension system, su,Dr)orted to the body at one related art reference. In a lower arm is rotatably position thereof one end -e is f iixed to the lower arm, whereas the of a spring plat other end of the spring plate is fixed to a front end of a torsion bar. Thus, when a load is aplied to the suspension system in the substantially front to rear direction of the body, the spring plate elastically deforms and the lower arm moves in the substantially front to rear direction of the body, thereby improving the riding comfort of the automobile.

The construction of such a suspension system does not have enough rigidity against a load which is applied i-n the lateral direction of the body of the automobile. Thus, a bending force may be applied to the torsion bar. In the suspension system disclosed in the second related art reference, to prevent such a bending force from being applied to the torsion bar, the vicinity of a front end of the torsion bar is supported to a f ront end of a support member extending from the cross member by a bushing. In add-it;,.--n, a portion extending from the X& i BAD ORIG- INAL 0 3 middle to the rear end of the torsion bar is movably supported by a cylindr-cal memiDer which is Supported by 'he cross member. Thus, this suspension system prevent-s a bending force from being app'ied to the torsion bar, thereby improving the rigidity in the lat-e-ral direction of the body of the automobile.

However, although the support member and the cylindrical member may prevenlt a bending force from being applied to the torsion bar, they will complicate the construction of the suspension system. Thus, such a suspension system is difficult, to practically use.

In Japanese Patent Application Laid-Open No. 62101507, a further suspension system is disclosed. This related art reference will hereinafter be referred to as the third related art reference. In this suspension system, a torsion bar is supported -by a lower arm at a plurality of positions thereof so as to prevent a bending force from being applied to the torsion bar. However, in the third related art -reference, the mounting construction of the lower arm and the torsion bar will become comolicated.

t 011 the present invention is to An objec. provide a suspension system for an automobile, which prevents a bending force from being applied to a torsion bar with a simple construction so as to improve the rigidity in a lateral direction of the body of the automobile and the riding comfort and steering stability thereof.

BAD ORIGiNAL 1 4 According to a -firs-- aspect of the present invention there is provided a suspension system for an automobile having first and second pivot portions on a body for supporting said suspension system, comprising a suspension arm for supporting a wheel, having first and second arm portions rotatably mounted on the first and second pivot portions, one of said pivot portions being disposed rearwardly of the other; a torsion bar having one end connected to said body; and a spring plate having a proximal portion mounted on said suspension arm, and a portion connected with the other end of said torsion bar, wherein an axial line of said torsion bar is offset in a substantially lateral direction of the body from a line connecting said first and second pivot portions, whereby said other end of the torsion bar is spaced apart from the line connecting said first and second pivot portions.

The suspension arm has the two arm portions each of which is supported b the two pivot portions. Thus, the suspension system has enough rigidity against a load applied in the subs tan tially longitudinal direction of the body, thereby preventing a bending force from being applied to the torsion bar with a simple construc-ion.

When a load is applied in the substantially front to rear direction c-f the body, the spring plate elastically deforms and thereby the suspension ar.,n moves in thIs direction. Thus, riding the automobile becomes comfortable.

When a load is applied in a substantially vertical direction cl' the body, the torsion bar twists and thereby a suspension force as the reaction force '..akes place. in addition, the soring plate bgnds and thereby an excessive bending moment is not applied to the torsion bar. Thus, the torsion bar may be constructed ef a thin and short member. As a result, the riding comfort and steering stability is imz)rcved.

BAD ORIGINAL L - 1 According to a second aspect of the present invention there is provided a suspension system for automobile, having first and second pivot portions on a body for supporting said suspension system comprising a suspension arm for supporting a wheel and having first and second arm portions rotatably mounted on the first and second pivot portions, one of said pivot portions being disposed rearwardly of the other; a torsion bar having one end connected to said body; a spring plate having a prcximal portion mounted on said suspension arm, and a portion connected with the other end of said torsion bar; a reference thread member arranged to connect said suspension arm and said spring plate; a cam thread member arranged substantially in parallel with said reference thread member opposite to said proximal portion of said spring plate to connect said suspension arm and said spring plate and having a drive cam portion being eccentric from a center of said cam thread member; and a follower cam portion provided on one of said spring plate and said suspension arm engaged with said drive cam portion to cause said spring plate to rotate with said reference thread member in a vertical direction of the body by rotating said cam thread member, so as to adjust the height of the body.

According to a third aspect of the present i=vention there is provided a suspension system for automobile, having first and second pivot portions on a body for supporting said suspension system comprising a suspension arm for supporting a wheel and having first and second arm portions rotatably mounted on the first and second pivot portions, one of said pivot portions being disposed rearwardly of the other; a torsion bar having one end connected to said body; a spring plate having a proximal portion mounted on said suspension arm, and a portion connected with the other end of said torsion bar; at least one tightening thread member arranged to connect said first arm portion and second arm portion to said spring plate; a cam thread member arranged to connect said first arm portion, said second arm portion and said spring plate and having a drive cam portion being eccentric t-c a center of said cam thread member; one of said first arm portion E3AD ORIGiNAL 6 and second arm portion having at least one oval hole extending in a substantially lateral direction of the body to receive said tightening thread member; and one of said first arm portion and said second arm portion having a follower cam portion engaged with said drive cam portion to cause said first arm portion and said second arm portion to relatively displace in a lateral direction of the body by rotating said cam thread member, so as to adjust a caster angle of the wheel.

According to a fourth aspect of the present invention there is provided a suspension system for automobile, having first and second pivot portions on a body for supporting said suspension system comprising a suspension arm for supporting a wheel and having first and second arm portions rotatably mounted on the first and second pivot portions rotatably mounted on the first and second pivot portions which are shifted with each other in a substantially front to rear direction; a torsion bar having one end connected to said body; a spring plate having a proximal portion mounted on said suspension arm, and a portion connected with the other end of said torsion bar; a joint holder interposed between said suspension arm and said wheel; a cam thread member connecting said suspension arm to said joint holder and having a drive cam portion being eccentric to a center of said cam thread member; and one of said joint holder and said'suspension arm having an oval hole as a follower cam portion to be engaged with said drive cam portion to cause said joint holder to displace in a laterla direction of the body by rotating said cam thread member, so as to adjust a camber angle of the wheel.

According to a fifth aspect of the present invention there is provided a suspension system for an automobile having a crossmember across a body thereof, comprising a suspension arm for supporting a wheel and rotatably mounted on said body; a torsion bar extending in a substantially front to rear direction of the body and having one end connected with said suspension arm; a spring plate extending from said body in a substantially lateral direction and having a free end portion for connecting with another end of said torsion bar, the free end connecting portion being shifted to a lower side with respect to said cross member, 7 wherein when a load is applied to the substantially front to rear direction, said spring plate elastically deforms, thereby allowing said suspension system to move in substantially front to rear direction; and a rubber bushing provided on said body supporting said spring plate so as to allow said spring plate to easily deform in the substantially front to rear direction.

Fig. I is a perspective view schematically showing a structure of a suspension system for an automobile including a spring plate; Fig. 2A is a perspective view schematically showing the structure of d first modification of the spring plate of Fig. 1; Fig. 2D is a plan view of Fig. 2A; Fig. 2C is a sectional view taken along line IIC-IIC of Fig.

2A; 2C; Fig. 2D is a sectional view taken along line IID-IID of Fig.

Fig. 3A is a perspective view schematically showing the structure of a second modification of the spring plate of Fig. 1; Fig. 3B is a view taken along line IIIE-IIIE of Fig. 3A; Fig. 4 is a perspective view schematically showing a third modification of the structure of the suspension system of Fig. 1; Fig. 5 is a perspective view schematically showing a fourth modification of the structure of the suspension system of Fig. 1; 1 suepsnion embodiment Fig.

Fig. 6 is a partial plan view showing the structure of a system for an automobile according to a first of the present invention; 7 is a perspective view showing the structure of a suspenion system of Fig. 6; Fig. 8 is a partial plan view showing the structure of a suspension system for an automobile according to a first modification of the first embodiment; Fig. 9 is a perspective view showing the structure of the suspension arm of Fig. 8; Fig. 10 is a partial plan view showing the structure of a 8 suspension system for an automobile according to a second modification of the first embodiment; Fig. 11 is a partial plan view showing the structure of a suspension system for an automobile according to a third modification of the first embodiment; Fig. 12A is a view for explaining a camber angle of a suspension system; Fig. 12B is a view for explaining a caster angle; Fig. 13 is a plan view showing the structure of a suspension body of a suspension system according to a second embodiment of the present invention; Fig. 14 is a perspective view showing the structure of the suspension body of Fig. 13; 1 9 Fig. 15 is an enlarged plan view showing a principal portion of Fig. 13; Fig. 16 is a side view taken along line XVI-Xvi o= Fig. 15; Fig - 17 are views showing the structure L 0 E an automobile height adjustment mechanism, where Fig. 17A is a sectional view taken along line XVIIA-XVIIA of Fig. 17B; Fig. 17B is a sectional view taken along line XVIIB-MIE of Fig. 17A, and Fig. 17C Is a sectional view taken along line)7;-IC-XVIIC oJE Fig. 173; Fig. 18 are views showing the structure of a caster angle adjustment mechanism, where Fig. 18A is a sectional view taken along line XVIIIAXVIIIA of Fig. 18B, Fig. 18B is a sectional view taken along line XVIIIBXVIIIB of Fig. 18., and Fig. 18C is a sectional view taken along line XVIIIC-XVIIIC of Fig.-18B; Fig. 19 are views showing the structure of a camber angle adjustment mechanism, where Fig. 19A is a sectional view taken along line XIXA-XIXA of Fig. 19B, and Fig. 19B is a sectional view taken alonc line X=B-XIXB of Fig. 19A; Fi.g. 20 are views showing the structure of a caster angle and camber angle adjustment mechanism, where Fig. 20A is a sectional view taken along line XXA-XXA of Fig.

20B. Fig. 20B is a sectional view taken along line XXBX= of Fig. 20A, Fic. 20C is a sectional view taken along line MC-XXC of Fig. 20B, and Fig. 20D is a sectional view taken along line XXD-XXD of Fig. 20B; Fig. 21 are views showing the structure of an automobile height and camber angle adjustment mechanism, where Fig. 21A is a sectional view taken along line XXIA-XXIA of Fig. 21B, Fig. 21B is a sectional view taken along line XXIB-XXIB c'L- Fig. 21A, and Fig. 21C is a sectional view taken along line xxIC-XXIC of Fig. 213; Fig. 22 are views showing the structure of a modification of the automobile height adjustment mechanism clE Fig. 17, where Fig. 22A is a sectional view taken along line MIA-XXIIA of Fig. 22B, Fig. 22B is a sect,cnal view taken along line =IB-XXIIB o-E Fig. 22A, and Fig. 22C is a sectional view taken along line XXIIC-MIC of Fig. 22B; s Fig. 23 are views showing the structure of a modification of the caster angle adjustment mechanism of Fig. 18, where Fig. 23A is a sectional view taken along line XXIIIA-XXIIIA of Fig. 23B, Fig. 23B is a sectional view taken along line XXIIIB-XXIIIB ot Fig. 23A, and Fig.

XXIIIC-XX1TIC of 23C is a sectlonal view taken along line Fig. 23B; is Fig. 1 is a schematic diagram showing the construction of a principal portion of a suspension system for an automobile useful in understandiriq the present invention. The suspension system is used for suspending a front wheel on the left or right of the automobile.

BAD ORIGINAL L_ id 11 A left-side lower arm (suspension arm) lla of Aletter shaped type is disposed on the left side of the automobile body. The left-side lower arm Ila has a ball joint l2a disposed at a front end thereof. The ball joint 12a is connected to a knuckle (not shown) at a lower end portion thereof. The lower arm lla has two pivot portions 13a and 14a which are disposed in front and rear positions of a distal portion thereof. The lower arm lla is rotatable about the pivot portions 13a and 14a to the body of the automobile. The center axis of the pivot portions 13a and 14a extends nearly in a substantially longitudinal (or front to rear) direction of the body. A right-side lower arm llb is opposed to the left-side lower arm lla and mounted on the right side of the body. The right-side lower arm lla is rotatable about pivot portions 13b and 14b. Likewise, the rightside lower arm 11b is provided with a ball joint 12b at a front end portion thereof.

The upper end portion of the knuckle is connected to 20 an upper arm (not shown) so as to rotatably support the wheel. Each of the lower arms is connected to a lower end portion of a shock absorber. In addition, the left I and right lower arms are connected with a stabilizer (not' shown). The arms, knuckles, and so forth principally construct the suspension system which suspends the front wheels on the left and right of the body of the automobile.

To the pivot portion 14a behind the left lower arm lla is fixed a front end portion of 21a. Likewise to the nivot portion a left torsion bar 14b behind the right lower arm llb is fixed a front end portion of a right torsion bar 21b. Thus, as shown in Fig. 1, each center axis of the torsion bars 21a and 21b almost accords with the center axis of the pivot portion thereof.

To a cross member of the body is fixed a rear end portion of each o f spring plates 24a and 24b by appropriate fastening means such as welding. The spring plate center plate 24a extends in a direction perpendicular to the axis of the torsion bar 21a. Likewise, the sprinc 24b extends in a direction perpendicular to the center axils of the torsion bar 21b. A sleeve 25a is Eront end portion (free end portion) of the welded to a 'L spring plate 24a. Likewise, a sleeve 25b is welded to a front end portion (free end portion) of the spring plate 24b. The sleeve 25a is f ixed to a rear end portion of E, torsion bar 21a. is the le:. Likewise, the sleeve 25b - fixed to a rea: end portion of the right torsion bar 21b.

In this suspension system, when a load is applied to the lower arms lla and llb in the substantially longitudinal direction of the body, t"he spring plates 24a and 24b bend in the arrow direction shown in Fig. 1, is thereby absorbing the load. Thus, a compression stress and a tensile stress against the torsi-on bars.21a and-21b are alleviated. In addition, the torsion bars 21a and 21b do not prevent the suspension system from bending and -ion of the moving in the substantially longitudinal direct body. Moreover, an excessive bending stress is _not applied to each of the torsion bars 21a and 21b.

In addition, the free end portions of the spring plates 24a and 24b fixed to the rear end portions of the torsion bars 21a and 21b are spaced apart from the cross member. Thus, without necessity of a rubber bushing, the suspension system can securely prevent the torsion bars 21a and 21b f rom directly contacting the cross member. Thus, when a load is applied thereto and the suspension system moves in this direction, the load is not transmitted to the body. As a result, the riding comfort is securely improved.

Figs. 2A, 2B, 2C, and 2D show a first modification of the Figure 1 de,lce. In Fig. 1, the spring plates 24a and 24b are mounted on the body by welding, whereas in Fig. 2, the spring plates 24a and 24b are mounted tc the body with bolts.

A reinforcement plate 41 is integrally connected to the front end portion of the spring plate 24a. Along with the reinforcement- plate 41, the spring plate 24a is mounted on the body B with bolts 42 and 43. As shown in Fig. 2C, the bolt 43 has a ca-m portion 44 on the head side thereof. The cam portion 44 is eccentrically formed on the bolt 43. The cam portion 44 is fit in an oval hole 45 formed on the reinforcement plate 41, the oval hole 45 extending in the substantially vertical direct.4 on of the bod-v. On the other hand, the bolt 42 is not eccentricallv mounted. Thus, the spring plate 24a is slidable about the bolt 42 alcnc with the reinforcemenlplate 41. Therefore, when both the bolts 42 and 43 are being loosened and then the bolt 43 is further rotated, the spring plate 24a is rotated about the bolt 42 and.thereby the proximal portion oil- the spring plate 24a moves in the substantially vertical direction of the body Consequently, the positions of the sleeve 25a can be changed with respect to the body B in the substantially vertical direction of the.body 1. Thus, the height of the body 3 can be adjusted. For the sake of simplicity, Fig. 2 shows only the mounting structure of the spring plate 24a. Thus, the mounting structure 'of the other spring plate 24b is the same as that of the spring plate 24a.

Figs. 3A and 3B show a second modification of the spring plate for the previously-described suspension system. A propeller shaft 47 and an exhaust pipe 48 are disposed at a center portion of the body B and extend in the substantially longitudinal direction thereof. A cross member 49 is disposed between the propeller shaft 47 and the exhaust pipe 46. The cross member 49 is connected to distal portions of the spring plates 24a and 24b with bolts.

The torsion bars 21a and 21b are respectively fixed to the sleeves 25a and 25b which are mounted on t-he distal portions of the spring plates 24a and 24b.

14 Fig. 4 shows a third modification.

The co:-,s-rict-ion of lower arms ",La and "ib of this modification is the same as that of the first embodiment. Eowever, in this mod-if-ical-- icn, a single spring plate 24 is disposed on a cross member of the body. The sr)-r-nc:)late 24 extends in a direction nearly perpendicular to the center axes of torsion bars 21a and -ends in the 21b. Thus, the spring plate 24 ext subs tantially lateral direction of the body. Rear end portions of the two torsion bars 21a and 21b are fixed to both proximal portions of the spring plate 24. The spring plate 24 is fixed to the cross member with two mounting members 31 and 32. The mounting members 31 and 32 are preferably of floating type where they each have a rubber bushing so that the spring plate 24 bends in the substantially longitudinal direction of the body. Eowever, the spring plate 24 may be mounted directly on the cross member with metal pins or the like.

z, lig. 5 shows a fourth modification.

in this modificatic.

n, as in the third modification shown in Fi9. 4, both proximal portions of a spring plate 24 are fixed to rear end portiQns. of torsion bars 21a and 21b, respectively. The both proximal portions jof the spring plate 24 are connected to a cross member by mounting members 33 and 34. Thus, the rear end portion of the left torsion bar 21a is disposed between the mounting members 31 and 33. The rear end portion of the right torsion bar 21b is disposed between the mounting members 32 and 34.

In the suspension systems according to the third and fourth modif _Scalt ions shown in Figs. 4 and 5, when a load, is applied thereto in the substantially rear direction of the body, the spring plate 24 elastically deforms. In addition, at this po-int, the Dorl--;or between the two mounting members 31 and 32 deforms, thereby cancelling the load applied thereto. Thus, the load applied to the body is reduced.

As a result, when a load is applied to BAD ORIGINAL the suspension system in the substantially longitudinal direction of the body, the suspension system bends Jrj this direction. Thus these suspension systems can provide good riding ccmfort.

In particular, in the modif ications shown in Figs. 4 and 5, the reaction force by the spring plate 24 against the body at the mounting members can be reduced. Thus, so-called floating bushings having rubber bushing-s as the mounting members 31 to 34 can be used. Therefore, the -Orily bend in 'the suspension systems can Sa±'SfaCL substantially longitudinal direction of the body. The bending characteristic in the substantially longitudinal f direction of the suspension system which uses a total ol four mounting members shown in Fig. 5 is superior to that of the suspension system which uses two mounting members shown in Fig. 4.

In the above-described device and the modifications thereof, the front end portions of the torsion bars 21a and 21b are fixed to the pivot portions 14a and 14b behind the lower arms lla and l1b, respectively. Thus, the center axes 0 the pivot portions accord with the respective center- axes of the I these axes do not accord torsion bars. However, even i with each other, the vresent invention may be applied. In this case, when the suspension system vertically moves, the front end ocrtions of the torsion bars 21a and 21b move in the substantially vertical direction of the body as the lower arms lla and llb rotate. Eowever, since the spring plates 24, 24a, and 24b elastically deform in their twisting directions, an excessive bending stress is qot applied to the torsi-on bars 21a and 21b.

Thus the suspension system smoothly moves inthe direction of the body. At this system always moves in the same the riding comfort and steering r substantially vertical point, the suspension path. As a result, stability is improved.

BAU L--- - - - --- J is 16 Figs. 6 and 7 show the construction cf a principal portion 011 a suspension system f 0 r an automobile according to the present invention. In these figures, a suspension arm 50 comprises a first arm portion 51 and a second arm portion 52 which is disposed behind the first arm r)crt-ion 51. A lower end portion of a knuckle (not shown) which rotatably supports a wheel W is connected to the arm 50 bv a ball joint 53. The sus-iension arm 50 is referred to arm or lower link. The suspension arm 50 the as a ", ower connects the lower end pcrticn of the knuck-'e and body. The first arm pcrt-on 51 and the second arm portion 52 are connected by connecting elements 54 and 55 which are for examiDle bolts. The suspension arm 50 is A-letter shaped arm.

first p. -ion The first arm portion 5.1 has a vot porl 61 into which a rubber bushing 53 is fitted. The first arm portion 51 is supported to a body B by the first pivot portion 61. Likewise, the second arm 62 has a second pivot portion 62 into which a rubber bushing 64 is fitted. The second arm portion 52 is supported to the body 3 by the second pivot portion 62.

The f. Lrst pivolt porticn 61 and the second pivot.

portion 62 are spaced apart from each other in the substantially longitudinal direction of the body B. A pivot axial line P which connects 'C-he centers of the first pivot portion 61 and the second pivot portion 62 extends nearly in the substantially longitudinal direction of the body B. Now assume that La denotes the distance between the center of the ball joint 53 and the center of the first pivot portion 61 in the substantially longitudinal direction of the body B. In addition, assume that Lb denotes the distance between the center of 53 and the center of the second pivot the ball joint portion 62 in the substantially longitudinal direction of the body B. At this point, the relation of La < Lb is satisfied. The volume of the rubber bushing 64 is larger an 17 than that of the rubberbushing 63. Thus, when a load is applied to the suspension system in the substantiially. longitudinal direction of the body E, the rubber bushing 64 in the second pivot 62 can more elastically deform than the rubber bushing 63 in the first pivot 61 does.

A proximal portion of a spring plate 66 made of a spring member material is disposed between the first arm portion 51 and the second arm portion 52. Thus, t h e proximal portion of the spring plate 66 is fixed to t h e suspension arm 50. The spring plate 56 extends inthe substantially lateral direction of the body j- As shown in the figures, the spring plate 66 is connected to the two arm portions 51 and 52 by the bolts 54 and 55.

However, the spring plate 66 may be connected to the arm p. ortions 51 and 52 by welding or rivets.

To the dist-al portion of the spring plate 66, is fixed to a front end portion 72 of a torsion bar 71. A rear end portion 73 of the torsion bar 71 is fixed to the body B. The front end portion 72 of the torsion bar 71 is connected to a sleeve 74 by a fitting element such as a spline. The sleeve 74 and the spring plate 66 are -i the front- connected by welding or the like so as to 'L' end portion of the torsion bar 71 and the spring plate 66. Likewise, the rear end portion of the torsion bar 71 is connected to a sleeve 75 by a fitting element such as a spline. The sleeve 75 and the body j are connected by welding so as to fix the rear end portion 73 of the torsion bar 71 and the body B. A center axis T of the torsion bar 71 and the pivot 30 axial line P make an offset angle 6. The center of the first pivot portion 61 and the center of the front end portion 72 of the torsion bar 71 deviate in the substantially lateral direction of the body bya predetermined offset distance S.

As shown in the figures, the front end portion 72 of the torsion bar 71 is mounted on the suspension arm 50 by the spring plate 66 which extends in parallel with the ]B center axis T of the torsion bar 71. Thus, the rigidity Z: 1, a ---ad in the of the suspension arm 50 against subs tar, tially longitudinal direction cf the wheel W is low, whereas the rigidity of the arm 50 against a load in the substantiallv vertical direction of the wheel W is high.

Thus, when a load is applied to the wheel W tantiallv long-tudinal direction of the bod-v subst front and rear rubber!Dushings 63 and 64 (3e--crm.

in the B, the Thus, the two arm portions 51 and 52 share I',)ad and nerebv tantial Iv the suspension arm 50 deforms i n t- h e s ubs t tion of the body However, the longitudinal direct rigidity of the spring plate 66 in the subst-antially longitudinal direction of the body E is low. Thus, as shown by two-dot line of Fig. 6, the spring plate 66 deforms in the substantially longitudinal direction or the body B. Therefore, an excessive bending force is not applied to the torsion bar 71. In addition, the torsion bar 71 does not prevent the suspension system from moving I. udinal direction of or bending in the substantially lonci. the body B. Thus, the suspension system can provide an 1 - - excellent riding comfort.

When a load is applied to the wheel W in the substantially lateral direction of the body B, the suspension arm 50 is pivotably supported to the body B by the two pivot portions 61 and 62. Since 'the pivot portions 61 and 62 do not elastically deform so much in,-he substantially lateral direction of the body B, satisfactory rigidity against a load in the substantially lateral direction of the body B can be obtained.

When the wheel W moves in the substantially vertical direction of the body, even if the pivol. axis P deviates from the center axis T of the torsion bar, there are offset distance S and offset angle 6. Thus, as the front end of the suspension arm 50 moves in the substantially vertical direction of the body, the spring plate 66 -S. In other w--r-ds, the spring plate 66 twists SO twis,k BAD ORGINAL 19 that the surface thereof inclines. Thus, an excessive - applied to t ion bar 71. The bending force is ncl. -he tors.

twisting torque of the torsion bar 71 is transmitted to the suspension arm 50 through the spring plate 66.

Therefore, the suspension system smoothly moves in the substantially vertical direction of the body B. Since the suspension system smoothly moves in the same path, excellent riding comfort and steering stability i S achieved.

To allow the suspension system to have satisfactory rigidity in the substantially lateral direction of the body B and keep sat is f actory bending amount in 'L h e substantially longitudinal direction of the body B, La should be much small ler than Lb. Because o f the difference of the volumes of the rubber bushincs 63 and 64, the first pivot 61 has a high rigidity in the substantially lateral direction of the body B, whereas the second Divot 62 has a low rigidity both in the substantially longitudinal direction and the lateral direction of 'the body B. As shown in the Ifigures, when the distance Lc between the line R which connects the center of the fir-st pivot 61 and the center of the ball -orsion bar 71 joint 53 and the force acting point of the 1. is as short as possible, most of the reaction force of the torsion bar 71 is applied to the first pivot portion 61. Thus, the rigidity in the substantially lateral direction of the body B, the bending amount in the -ion of the body B, and substantially longitudinal direct -uning are nearly unaffect the vibration -ed.

The suspension arm 50 is a lower arm which connects the lower end portion of the knuckle to the body. The upper end portion of the knuckle is connected to the body by for example an I-letter shaped upper arm (not shown).

Between the suspension arm 50 shown in the figure or the upper arm and the body, a known shock absorber (not shown) is disposed. Eowever, the suspension arm 50 may be used for an upper arm which connects the upper end portion of the knuckle to the body.The suspension arm L, Lront shown in the f igure S U P p 0 r t 5 the left-side 0 wheel. The right- side front wneel can be supported by i on. in addition, the rear the arm in the same constructwheels can be also supported by arms basically in the same construction.

Figs. 8 and 9 show the construction of a principal portion of a suspension system according to a first modification of the first embodiment. For the sake of simplicity, the nortions in Common W J. t h the first embodiment are denoted by the same reference numerals.

In the first embodiment, the other end portion 73 of the torsion bar 71 is fixed to the body B through the sleeve 75. In the suspension system according to this modification, the other end portion 73 of the torsion bar 71 is connected to a cross member of a body B by a second spring plate 67. The spring plates 66 and 67 extend in parallel with a center- axis T of the torsion bar 71. As in the second embodiment, the spring plates 66 and 67 have a high rigidity in the su'bstantially vertical direction oil the body and a low rigidity in the substantially longitudinal direction of the body B. In this modification, when a load is applied to a wheel W in -he substantially longitudinal direction of the body B or when the wheel W moves in the substantiallv vertical direction of the body B, a bending force applied to the torsion bar 71 can be remarkably reduced in comparison with the construction of the second embodiment because the two spring plates 66 and 67 deform.

Fig. 10 shows the construction of a suspension system according to a second modification of the first embodiment. In this suspension system, spring plates 66 and 67 are disposed on both end portions of a torsion bar 71. A first arm portion 51 is branched from a second arm portion 52. The first arm portion 51 and the second arm portion 52 are integrally constructed by a means such as weldinc. A ball joint 53 is disposed at a f ront end portion of the second arm portion 52. At an end portion of t.he first arnn pertion 51, a first p-Jvc-- pc-rtion 61 _s disposed. The first spring plate 66 is connected to the second arm portion 52 by a particular means such as welding. A line connecting the firs', and second pivot portions 61 and 62 extends in a substantially lonc:-i't--ud-inal directior of 'the body, 'the torsion bar 71 extends in parallel w-".-i the line, and the siDring plate 66 is arranged in front of the first and second arm 10 portons 51 and 52.

-iG. 11 shows third modification a suspension system according to a c- the first embodiment. In this examr)le, a second arm portion 52 extends almost in a subs -a-iiallv lateral direction of a body B. A front end 15 pprt-J--.n of a first arm 51 'is connected to a center portion of a second arm portion 52 by welding, bolts, or the like. The first arm 51 inclines in the substantially front direction of the body B. A pivot portion 61 disr)osed at a rear end portion of the first arm portion t ion -5l inclines in the substantially long i l-udinall directof the body B. The suspension system moves in the E substantially longitudinal direction cl-. the body B according to the characteristic of a resilient substance of the first pivot portion 61. The first pivot portion 61 is rotatable with an angle substantially in line with the body; the second pivot portion 62 is rotatable in the subs tant ially longitudinal direction of the body; the torsion bar 71 extends in the substantially longitudinal direction; and the spring plate 66 is arranged in front of the first and second arm portions 51 and 52.

Next, a second embodiment of the present invention will be described. The second embodiment relates to a suspension system for an automobile, in particular, to a suspension system having a wheel alignment mechanism.

As shown in Figs. 12.11. and 12B, a knuckle 80 rotatably supports a wheel W. A lower end portion of the knuckle 80 is connected to a lower arm 82 through a ball BAD 0,1 j, j u- i L_. 4d 22 joint 81. An upper end portion of the knuckle 80 J. s connected to an upper arm 84 through a ball joint 83.

Proximal portions of the arms 82 and 84 are rotatably mounted on a body In the case of a front wheel, when the body B is turned, the wheel W is turned about a line connecting the centers of the upper and lower ball joints 81 and 83 (namely, a turning center axis or a king pin axis S). When the body is viewed from the front, the angle made by the center plane of the wheel W and the vertical plane v is refferred to as a camber angle a. The camber angle a varies according to the inclined angle of the king pin axis S in the substantially lateral direction of the body B. This camber angle affects the steering force.

is As shown in Fig. 12B, when the wheel W is viewed from a side, the inclined angle of the king pin axis S in the substantially longitudinal direction of the body B is referred to as a caster angle P. This caster angle affects the direction holding force of the wheel W. The height of. the body 11 is given by the position in the substantially vertical direction (Z direction) of the 1 wheel W to the body B. After the automobile is assembled, 'the height of the body B and the wheel alignment such as camber angle can be adjusted so as to securely provide steering stabilit-Y thereof.

An object of the third embodiment is to provide a suspension system which has both a torsion bar movable in a substantially longitudinal direction of a body and wheel alignment, such as camber angle and caster angle, and body height adjustment mechanism.

Figs. 13 and 14 show a principal portion of a suspension system for an. automobile according to a third embodiment of the present invention.

in these figures, a suspension arm 90 comprises a - member) 91 and a second arm first arm, portion f ront pc.rtion (rear member) 92. The second arm portion 92 is 23 disposed behind the first arm portion 91. A lower end portion of a knuckle (not shown) which rotatably supports L a wheel W is connected to the arm 90 by a ball joint (connecting portion) 93. The suspension arm 90 is referred to as a lower arm or lower link. The suspension arm 90 connects the lower end 1Dertion of the knuckle with the body. Thus, the suspension arm 90 accords with the lower arm 82 of the suspension system shown in Fig. 12. The first arm portion 91 and the second arm portion 92 are threaded as will be described later. The suspension arm 90 is a letter-A shaped arm. A front end portion of the first arm portion 91 is threaded to a joint holder 94 as will be described later. The joint holder 94 constructs the first arm port.on 91. The ball joint 93 is mounted on the joint holder 94.

The first arm portion 91 is provided with a first pivot portion 95 in which a rubber bushing 96 is fitted. The first arm portion 91 is supported by the first pivot portion 95. Likewise, the second arm portion 92 is provided with a second pivot portion 97 in which a rubber ted. The second arm port bushing 98 is fitt -.ion 92 is supported by the second pivot portion 97. Thus,the first pivot portion 95 and the second pivot portion 97 are spaced alpart in a substantially longitudinal 2, direction of the body B. A pivot axial line P which connects the centers of the first pivot portion 95 with the second pivot portion 97 extends in the substantially longitudinal direction of the body B. The volume of the rubber bushing 96 is large., than that of the rubber bushing 98. Thus, when a load is applied to the suspension system, the rubber bushing 98 in the second pivot 97 more elastically deforms than the rubber bushing 96 in the first pivot 95 does.

E An end portion of a spring plate 101 made of a leal spring member is disposed between the first arm portion 91 and the second arm portion 92. Thus, the proximal portion of the spring plate 101 is fixed to the 10;-, o 9 24 suspension arm 90. The spring plate 101 extends in the substantially lateral direction of the body B. The other proximal portion of the spring plate 101 is fixed to a front end portion of a torsion bar 102. A rear end portion Of the torsion bar 102 is fixed to the body B. The front end portion of the torsion bar 102 is spline connected to a sleeve 103. By weldinQ the sleeve 103 and -he spring plate 101 is f -ixed to the spring plate 1011, 'L the front end port,---- olf the torsion bar 102. Likewise, sleeve 104 is s::)'--;r.e-connecll--ed to the rear end the torsion bar -, 02. By welding the sleeve 10,1t and the body B, the rear end portion of 'the torsion bar 102 is fixed to the body E.

As shown in F ig 15, the spring plate 101 is disposed between the first arm portion 91 and the second arm portion 92. In addition, the first arm portion 91, the second arm portion 92, and the spring plate 101 are integrally connected with a total of three bolts 111, 112, and 113.

The joint holder 94 is integrally connected to the first arm portion 91 with 'the bolt 111 and thr-ee Other bolts 115, 116, and 117. 1 Figs. 17A, 17B, and 17C, show a princ pal portion of' a suspension system where the suspension system according to the third embodiment shown in Figs. 13 to 16 is provided with a body height adjustment mechanism. In Figs. 17.A to 17C, 'three bolts 111 to 113 which connect a 'first arm portion 91, a second arm portion 92, and a spring plate 101 are enlarged. The first arm portion 91 and the second arm portion 92 are formed by bending a steel material. The interior of these first arm portion 91 and second arm portion 92 are hollow. The first arm portion 91 and the second arm portion 92 have openings according to these belts. Thus, these bolts can be inserted from the outside into the openings formed on the first arm portion 91 and the second arm portion 92.

The bolt 111 passes through the f ir-st arm port -on 91. In addition, the bolt ill passes through the '.ront end portion of the second arm portion 92 and a proximal portion of the spring plate 10-1. The bolt 111 ext-ends in the substantially longitudinal direction of the body B. The bClt- 111 and a nut 121 which is thread onto the front end portion thereof construct- a reference thread member. Holes for the arm portions 91 and 92 and the spring plate 101 through which the bolt 111 passes acccrd W 4 th -the outer circumference of the bolt ill. -.he two bolts!12 and 113 are mounted on a circumference G with the radius of curvature as the bolt 111. The bolts -112 113 are mounted nearly in iDarallel with the bolt 111. the bolts 112 and 113, the first arm r)ortion 91, second arm por.tion 92, and %the spring plate 101 connected.

The bolt 112 and a nut 122 which is thread onto the front end thereof construct a cam thread member. The bolt 112 on the nut 122 is tightened by a tool inserted from an opening formed on the second arm portion 112. The boll t 112, which is the cam thread member, is fit to circular holes 131 and 132 which accord with the center of the bolt 112 formed on the first and second armportions 91 and 92. The bolt 112 has a drive cam portion 112a which is eccentric from the center thereof. The drive cam oortion 112a is engaged with a follower cam portion 133 formed on the spring plate 101. The follower cam portion 133 is 11crmed of an oval hole which extends in the radial direction R connecting the center of the bolt 111 and the center of the bolt 112, namely in a direction perpendicular to the circumference G.

The bolt 113 is a reinforcement bolt. The bolt 113 passes through circular holes formed on the first arm portion 91 and the second arm portion 92. In addition, as shown in the figure, the bolt 113 passes through an oval hole 134 which extends in the direction of the circumference G of the spring plate 101. Thus, while the s am e a n d 2 v the 26 nuts 121, 122, and 123 which are thread onto the three bolts Ill, 112, and 113 are being loosened, when the nut 112 as the cam thread member is rota ted, a iDroximai portion of the spring plate 101 connected to the tc)-rsion bar 102 vertically deforms about the bolt 111. Thus, as shown in Fig. 16, the spring plate 101 vertically rotates about the bolt 111 for an angle 51. Therefore, proximal portion of the sPring plate 101 deforms about the ball jo-,n-- 93 fc-- ball joint 93 vertically deforms "' the body is Therefore, the height cl automobile has been assembled, when is performed, the height of the body tighteni-ng the nuts, the adjustment bolt 112 and the belt 113 may reinforcement bolt and the cam respectively.

Figs. 18A, 18B, and 18C show a susmension system having a adjustment mechanism. A bolt 111 threa. d thereto construct a cam - arm portion 91, a tightens a first t-- the vertically an anc-e 2. The aca-inst t h e bodv.

adjusted. After an the wheel alignment, can be adjusted. By is completed. The be used for the thread member, a principal Dortion of wheel caster angle and a nuz 12-1 which is thread member which second arm portion 92, and a spring plate 101. The bolt 111 has a drive cam portion llla which is eccentric to the center thereof.

The second arm portion 92 has two follower cam portions which are engaged with the drive cam portion 111a.

The follower cam portions 135 are opposed in a substantially lateral direction of a body. Two bolts 112 and 113, which are disposed in parallel with the cam thread member 111, and nuts 122 and 123 which are thread thereto construct a tightening thread member. The bolts 112 and 113 pass through oval holes 132 and 132a formed on the second arm portion 92. The oval holes 132 and 132a extend in the substantially lateral direction of the body. The bolts 112 and 113 are f it to circular holes formed on the f irst arm portion 91 and the spring plate 101, respectively. Thus, while the three bolts 111 to L BAD ORIGINAL J0 27 113 are being loosened, when the bolt 111 as the cam thread member is rc,ated, the Dosition of -e seccn(f arm - L. I ocrtion 92 to the i:-irst arm -DOrtiOn 91 in the lateral direction of the body varies as shown by arrow Y of Fig. 15. In the figure, the positions of the center 01 of the first Z)-JV0t Portion 95 and the center 02 of the second pivot portion 97 against the body do not chance. Thus, first arm portion 91, namelthe front end:)Or-L on of the If t 93, moves in the the nos;.tion C1 -he ball -lc-nt substantially lcngitudinal direction X of the body. As a result, 'the caster angle of 'the wheel is ac3usted. After this adjustment is completed, the nuts are tightened.

Figs. 191P- and 19B show a principal portion of a suspension system having a wheel camber angle adjustment mechanism. The figures show a portion where a joint holder 94, first and second arm portions 91 and 92, and a spring plate 1-01 are connected to each other. These oortions are connected by a cam thread member which is constructed of a bolt 111 and a nut 121 thread thereto.

The bolt. 111 has a drive cam portion 111b which is eccentric to the center thereof. The drive cam portion lllb is formed on a joint holder 94. T-he- drive cam portion lllb passes through a follower cam:)orticn 136 which is an oval hole extending in the substantially vertical direction of the body.

On the other hand, bolts 115 to 117 extend in a direction nearly perpendicular to the bolt 111, namely in the subs tant i ally vertical direction of the body. The bolts 115 and 117 and nuts 125 to 127 which are thread thereto constitute a tightening thread member. The bolts 115 to 117 pass through oval holes 137 to 139 formed on the joint holder 94. The oval holes 137 to 139 extend in the lateral direction of the body. Thus, while the nuts 121 and 125 to 127 are being loosened, when the bolt 111 as the cam thread member is rotated, the drive cam portion 111b and the follower cam portion 136 are engaged with each other. Thus, the joint holder 94 deforms in BAD ORIGiNAL 1 JZJ 28 the substantially lateral direction of the body. As a result, the camber angle of the wheel can be ad-,iusted.

Thereafter, by tightening all the nuts,,,ne ac-lustment IS comDleted.

in the embodiment shown in Figs. 19A and 19B, the follower cam portion 136 is formed c-,, the joint 1-101derr 94. Eowever, the follower cam r)crtic,-. 136 may be formed on the first arm portion 91, 'the second arm portion 92 1 and t.1,e spring piate 101. At lhis cam pertion 66 is encaged with the drive ca.--, pertion holder 9 'L-S fit to a lilb. In this case, the joInt I- portion which is not eccentric to the bolt 111. As the boilill is rotated, the joint holde- 94 deforms in the lateral direction of the body against t h e first arm portion 91. Thus, the camber angle of the wheel can be adjusted.

Figs. 20A, 20B, 20C, and 20:) show a principal portic.n. of a suspension systen, having a mechanism whJc.,i can adjust the overall body height, caster angle and camber angle of a wheel. A first arm portion 91, a -e 101, and a joint second arm portion 92, a spring plat holder 94 are connected to each oLher bv a firs' can thread member. The first cam thread member, is 0 a bolt 111 and a nut 121 which is threaded constructed ol thereto. The bolt 111 extends in a substantially longitudinal direction of a body. on a circumference G With t-he same radius of curvature from the center of the bolt 111, two bolts 112 and 113 are mounted nearly in parallel with the bolt 111. By these bolts 112 and 113, the first arm portion 91, the second arm portion 92, and the spring plate 101 are tightened to each other.

A bolt 112 and a nut 122 which is threaded onto the front end thereof construct a second cam thread member. The boil. 112 is fit to a circular hole 131 formed on the first arm portion 91. As in the embodiment shown in Figs. 17A, 173, and 17C, the bolt 112 has a drive cam pcr'-ion 1-12a. The dr.Lve cam portion 112 is engaged wJtt.

BAD ORIGINAL 29 a follower cam r)or'tion 133 formed on the spring plate 101. As in the embodiment shown in Fig 17C, a reinj'-orce.mentt bolt 113 is f-t- to a circular hole formed on the first arm portion 91. in addition, the reinforcement bolt 113 passes through an oval hole 134 formed on the spring plate 101. In t-he mechanism shown -ruction of the spring plate 101 is in Fig. 20, the cons the same as that shown in Fig. 17. Thus, while the nuts 121, 122, and 123 are being loosened, when bolt ill is rc'tated, the body height can be adjusted.

truct The bolt ill which const s the first cam thread member has a drive cam portion Illa which is eccentric,-.c the center axis thereof as in the embodiment shown in Fig. is. On the second arm portion 92, two follower cam portions 135 which are engaged with the drive cam portion ilia are. opposed7 in the substantially lateral direction of the body. On the second arm portion 92, as shown in Fig. 20C, oval holes 132 and 132a which extend in the subs tan t _Jally lateral direction of the body are formed.

The belts 112 and 113 pass through the oval holes 132 and 132a, respectively. Thus, while the three bolts 111 to 113 are being loosened, when the bolt ill as the firs', cam thread member is rotated, a front end portion of the second arm portion 92 deforms in the substantially lateral direction of the body against the first arm portion 91 as in the embodiment shown in Fig. 18. Thus, the casterr angle of the wheel can be adjusted.

A bolt 115 is one of three bolts which connect the joint holder 94 to the first arm portion 91. The bolt 115 and a nut 125 which is threaded thereto constitute a third cam thread member. The bolt 115 has a drive cam portion 115a. The drive cam portion 115a is fit to an oval hole 137a formed on the joint holder 94. The oval hole 137a extends in the substantially longitudinal direction of the body. The other two bolts 116 and 117 are tightening bolts. The bolts 116 and 117 pass through oval holes 138 an 139 which extend in the substantially 13AD 0HIGili,.,AL_ 1 1 L_ - I- J. I_ lateral direction of the holder 94. M11 h - e hu s, - and are formed cn the join t. hree bolts 1115 -__ - 1 beins loosened, when.he bolt -1 1-5 as the thirc --am member is rotated, the jo-Lnt inolder 94 deffcrns in the substantially lateral direction of 11--he body. Thus, a ball joint 93 disposed at E nL end portion of the - holder 94 deforms in th e substantla" I joinl -lateral direction of the bodv. Thus, tne camber a-cle of the wheel- can be ad-lusted.

0 After the body heicht, the caster anc-e, a n z t'- e camber angle have beer. adjusted, by tightening. the bolts tment is completed.

and nuts, the adjust Figs. 21A, 213, and 21C show a principal portion of a suspension system having a mechanism which can adjust both body height and camber angle of a wheel. A bolt 41 extends in a substantially longitudinal direction of a body and connects a first arm portion 91, a second arm portion 92, and a spring plate 101. The bo",-. 111 and a nut 51 which is threaded thereto constitute a -first cam thread member. As in the embodiment shown in Fig. 17, the first arm portion 91, the second arm portion 92, and 112 and a the spring plate 101 are connected by a bo tightening bc1t 1'3. The bolt 112 constitute a second cam thread member. As in the embodiment shown in Fig. 17, the bolt 112 has a drive cam portion 112a.

spring plate 101 has an oval hole 63 as a follower portion. Thus, while the three bolts 111 to 113 being loosened, when the bolt 112 as the second thread member i s rotated 'the body height can adjusted.

As in the embodiment shown in Fig. 19, IC-he bollt 111 as the first cam thread member has a drive cam portion 111b which is eccentric to the center thereof. The drive cam portion 111a is fit to an oval hole 136 Formed on a joint holder 94. The oval hole 136 extends n a substantially vertical direction of the body. The oval hole 136 is a follower cam portion.

body Che ----are hread The cam are cam be As in the embodiment BAD ORIGINAL C 1 L 4tw S 1 shown in Fig. 19, three bolts 115 to 117 which connect the f irst arm portion 91 and the jc-nt holder 94 z)ass throuch oval holes 137 to 139 formed on the JOint hclder 94. The oval holes 137 to "39 extend in the substantially lateral direction of the body. Thus, the bolts 111 and 115 to 117 are beJnc loosened, when the bolt 111 is rotated, the join'. holder 94 deforms in the the bodv. Therefore, as inthe lateral direction o. embodiment shown in F, 19. 19, --ne ca:-..be.- ang- 7e of the 10 wheel can be ad-justed. J After the bod-j heiaht wheel have been adjusted, and the ca-mbe-- angle of zhe all the bcl',-s aretightened withthe nuts. Thus, the adjiust-ment. is completed. 7 n he in Figs. 20 and 21, as in the embodiments shown embodiment shown in Fig. 17, the funct-ions of the bolts 1 12 and 113 may be reversely designated. In other words, the bolt 112 and the bolt 113 may be used for a reinforcement bolt and a cam thread member, respectively.

Figs. 22A, 22B, and 22C show the construction of a modification of the suspension system having the body height adjustment mechanism shown in Fig. 17. in this modification, two follower cam portions 133a and 133a are opposed on a circumference G. The two follower cam portions 133a and 133a are disposed on a first arm portion 91 through a bolt 112.' The bolt 112 constructs a cam thread member. A drive cam portion 112a which is engaged with the follower cam portions 133a and 133a is disoosed eccentrically from the center of the bolt 112.

As shown in Fig. 22C, a spring plate 101 has oval holes 134 and 134a on the circumference G. The bolts 112 and 113 pass through the oval holes 134 and 134a. Thus, when the bolt 112 is rotated, the spring plate 101 is rotated about the bolt 111 against the first arm portion 91 and the second arm portion 92. In the suspension system of this type, as in the embodiment shown in Fig. 17, the body height can be adjusted.

BAD ORIGii,4,_ I---- 3? Figs. 23A, 233, and 23C show another modification o the suspension system having the caster angle adjustmen mechanism shown in Fig. 18. In this modification, first arm portion 91, a second arm portion 92, and a spring plate 101 each have an oval hole 135a as a follower cam oortion. A drive cam iDcrtlon 111c which is engaged with the follower cam portion 135a is disposed on a bolt 111. The ovall hole 135a as the follower cam portion extends in a subs tant -Jally vertical directon of the body as shown -n Fig. 23A. Thus, when the bc-- -1- -at 92 n a is rot ed, the second arm TDCrt-'Cn MC',.7 e S subs tantially lateral direction of the body against the first arm portion 91 and the spring plate 101. As a result, a front end portion of the first arm portion 91 moves in a substantially longitudinal direction Y of the body. Therefore, the caster angle can be adjusted.

In each modification of the third embodiment, the orientations of all the bolts and nuts which are threaded thereto can be reversely designated with respect %to each other. In consideraticn of the operability of- tools for use, the orientations of the bolts and the nuts may be designated in any direction.

Reference is directed to co-pending Application No 9316853.2 which claims matter described in this application.

1 1 BAD ORIGINAL 33

Claims

CLAIMS:.

I. A suspension system for automobile, having first and second pivot portions on a body for supporting said suspension system comprising:- a suspension arm for supporting a wheel and having first and second arm portions rotatably mounted on the first and second pivot portions, one of said pivot portions being disposed rearwardly of the other; torsion bar having one end connected to said body; spring plate having a proximal portion mounted on said suspension arm, and a portion connected with the other end of said torsion bar; at least one tightening thread member arranged to connect said f-irst arm portion and second arm portion to said spring plate; a cam thread member arranged to connect said first arm portion, said second arm portion and said spring plate and having a drive cam portion being eccentric to a center of said cam thread member; one of said first arm portion and second arm portion having at least one oval hole extending in a substantially lateral direction of the body to receive said tightening thread member; and one of said first arm portion and said second arm portion having a follower cam portion engaged with said drive cam portion to cause said first arm portion and said second arm portion to relatively displace in a lateral direction of the body by rotating said cam thread member, so as to adjust a caster angle of the wheel.