CA1248565A - Suspension apparatus for vehicle - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE
Telescopic members which are expanded and contracted by a fluid pressure controlled by a steering mechanism are integrally connected to suspension springs. When a vehicle makes a turn, the body is caused to decline toward the turning center side due to the telescopic movement of the telescopic members according to the steering operation. The fluid pressure may be fed from a hydraulic cylinder including a piston associated for movement with the steering mechanism. Alternatively, fluid pressurized by a pump may be fed through a controlling valve which is actuated in response to the steering mechanism. At a time when the vehicle makes a turn, a satisfactory steering sense similar to a motorcycle can be obtained.

Description

1~4~3565 This invention relates to a suspension apparatus for a vehicle such as an automobile or a motor tricycle, having at least one unit with a pair of right and left wheels.

In a vehicle which has such a pair of right and left wheels, the body tends to incline outwardly or to the side remote from the turning center of the vehicle when it turns, due to cen-trifugal force. However, in a motorcycle, the turn is made whlle inclining its body inwardly. In other words, the motorcycle makes a turn in a leaning state. The present invention intends to dec]ine a body of an automobile or a motor tricycle toward the turning center side during turns, so that a driver of the automo-blle or the motor tricycle can en~oy the same sort of driving sense or feeling as that of the motorcycle.
One example of such a motor tricycle which can decline lts body toward the turning center side when it turns is dis-closed in Japanese Laid-Open Patent Publication (Kokai Tokkyo Koho) NO. sho 54-25033. This motor tricycle has a pair of rlght and left front wheels and one rear wheel. It is designed such that when it turns, a driver shifts his weight toward the turning center side reslstlng the centrifugal force in order to decllne the vehicle body toward the turnlng center side. Slnce this motor tricycle ls of a saddle type ~ust the same as a common motorcycle, the driver can comparatlvely easily shlft hls weight to decline the vehicle body as described above. However, in the case of a common automobile where the driver sits on a seat, it is not necessarily an easy ~ob for him to decline the vehicle body by shifting his weight.
The present lnvention thus provides a suspension appa-ratus for a vehicle, wherein the vehicle body can be automati-cally declined toward the turning center side by means of steer-ing operation and without the drlver's intended shifting of his weight to that direction irrespective of whether the vehicle is of said saddle type or seat type.

~1248565 The present invention also provides a suspension appa-ratus for a vehicle, wherein the entire length of a suspension spring is changed by expanding and contracting a telescopic mem-ber provided integrally with said suspension spring thereby caus-ing to decline a vehicle body.

The present invention also provides a suspension appa-ratus for a vehicle, wherein said telescopic member is expanded and contracted by means of a fluid pressure regulated by a steer-ing mechanism.
According to the present invention therefore there isprovlded a suspenslon apparatus for a vehicle provlded between a pair of left and right wheels of the vehicle and the vehicle body, comprlslng telescopic members integrally connected to sus-pension sprlngs and expanded and contracted by means of fluld pressure, fluld passages for feeding fluid pressurized by a pump to sald telescoplc members and discharging the fluid from sald telescopic members, controlling valves provided in said fluid passages, each valve havlng a cylindrical inner valve member, a cylindrlcal outer valve member rotatably fitted on said lnner valve member and a maln body containing and supporting sald inner and outer valve members for rotation respectively, means for con-necting each said inner valve member to a steering mechanism to rotate said inner valve member in accordance with the movement of said steerlng mechanism, and means for connecting each said outer valve member to one of said telescopic members to rotate said outer valve member in accordance with the movement of said tele-scopic member relative to the vehicle body, whereby the control-ling valves are connected to the steering mechanism and to saidtelescopic members to control said valves not only with respect to the steering but also wlth respect to the movement of the telescopic members relative to the vehicle body so that the veh-icle body is caused to decline toward turnlng center side due to telescopic movement of said telescopic members in accordance with a steering operation. Desirably said means for connecting each ,, 12~35~5 inner valve member to a steering mechanism is a first lever por-tion piece formed on said inner valve member which is directly connected to a moving bar of the steering mechanism; and whereln said means for connecting each outer valve member to one of said telescopic members is a second lever portion piece formed on said outer valve member which is directly connected to a plston side member of said one of said telescopic members.

Thus, in a suspension apparatus according to the pre-sent invention, a telescopic member expanded and contracted bymeans of a fluid pressure regulated by a steering mechanism is provided integrally with a suspension spring and when a vehicle makes a turn, said telescopic member is expanded and contracted accordlng to steerlng operatlon thereby causlng to decllne a vehlcle body in the turnlng center slde.
Sald fluld pressure may be supplied to said telescopic member from a hydraulic cylinder including a piston associated for movement with said steerlng mechanism. Alternatively, a fluid pressurized by a pump driven by an engine may be supplied to said telescopic member through a controlling valve whlch oper-ates in response to said steering mechanism~

According to the present lnventlon, when the vehlcle makes a turn, a driver can en~oy a similar steering operation sense or feeling as that of a motorcycle.

The present invention will be further lllustrated by way of the accompanying drawings, in which:-Fig. 1 is a front vlew of a suspension apparatus ~ according to one embodiment of the present-invention when a veh-; icle is running in a straight line;

Fig. 2 is a front view of the suspension apparatus of ' Fig. 1 when the vehicle ls turning;
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12'~ 5 Fig. 3 is a front view of a suspension apparatus according to another embodiment of the present invention when the vehicle is running in a straight line in which the hydraullc sys-tem is not shown;

Fig. 4 iS a front view of the hydraulic system of the suspension system of Fig. 3 when the vehicle is running in a straight line;

Fig. 5 is a view showing a part of the hydraulic system at a certain time;

Fig.s 6 and 7 are views showing a part of the hydraulic system at a time when the vehlcle is turning;

Flg. 8 ls a horlzontal sectional vlew of a controlling valve;

Fig. g is a sectional view taken along line IX-IX of Flg- 8; and Fig. lO is a perspective view showing a concrete con-stltution of a suspension apparatus.

Preferred embodiments of the present invention will be described hereunder with reference to the accompanying drawings in which the suspension system is applied to a motor tricycle having a pair of front wheels and one rear wheel.

Fig. 1 and Fig. 2 illustrate a flrst embodiment of the present invention. More specifically, Fig. l is a front view of a suspension apparatus when the vehicle is running ln a straight line, and Fig. 2 is a front view of the same when the vehicle is , turning left. The expression ~right~ or ~left~ as used hereln means right or left to the driver. 1l denotes a left front wheel, 12 denotes a right front wheel, and 2 denotes a body of a i I ~ _ 4 _ 12/-~3565 motor tricycle. The right and left front wheels 11,l2 are inte-grally provlded with knuckles 31'32' respectively, to the lower ends of which lower arms 41'42 are connected via ball ~oints 51'52' respectively, while, the upper ends of said knuckles 31'32 are connected with upper arms 61,62 via ball joints 71~72~
respectively. The other ends of the lower arms 41~42 are piv-otally connected to the body 2 via brackets 81,82 and the other ends of the upper arms 61,62 are pivotally connected to the body

2 via brackets 91~92~ The foregolng arrangement constitutes the so-called double wishbone type suspension.

Said knuckles 31'32 are provided with knuckle arms 101,102 extending backwardly therefrom. The knuckle arms 101,102 are connected with tie rods 121,122 via ball ~oints 111,112. The other ends of ! 25 '' 30 ~ 35 h' ~ - 5 -';

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said tie rods 121, 122 are pivotally connected to both ends of slider 13 respectively. Said slider 13 is slidably supported on the body 2 via a bearing 21. Said slider 13 is provided at its central portion with a rack 17, with which a pinion 18 mounted on a steering shaft 19 meshes. 20 dPnotes a steering wheel.

141, 142 denote right and left suspension springs respectlvely. These suspension springs 141, 142 are provided at the upper portions thereof with hydraulically operated telescopic members 2~1, 242 comprising a piston 22 and a cylinder 23. The upper ends of said suspension springs 141, 142 are secured to the body 2 vla pivots 151, 152 and said brackets 91~ 92~ while the lower ends of said suspension springs 141, 142 are secured to the intermediate portions of said lower arms 41~ 42 via pivots 161, 162.
Cylinders 231, 232 f said telescopic members 241, 242 are communicated with cylinder chambers 261, 262 f a hydraulic cylinder 26 through hydraulic pipe lines 251, 252, respectively.
Within said hydraulic cylinder 26, a hydraulic piston 27 adapted to partition said cylinder chambers 261, 262 is reciprocally moveably provided. A piston shaft 28 of said hydraulic piston 27 is connected to said slider 13 via an arm member 29. And the insides of said cylinder 23, hydraulic pipe 25 and hydraulic cylinder 26 are filled with oil.
When the vehicle run in a straight line, the pinion 18 meshes with the rack 17 at the central position thereof as shown in Fig. 1. However, when the vehicle is going to make, for example, a left turn, the steering wheel 20 is turned clockwise as shown by an arrow a as in Fig. 2. Then, due to the rotation of said pinion 18, the slider 13 slides to the right, as shown by an arrow b. Since the hydraulic piston 27 is also moved to the right within the hydraulic cylinder 26 in accordance with the movement of said slider 13, the oil within the cylinder chamber , .~

;~Z~85~5 262 is sent to the cylinder 232 through the hydraulic pipe line 252 and the oil flows into the cylinder chamber 261 from the cylinder 231 through the hydraulic pipe line 251. Since coil springs 301, 32 of the suspension springs 141, 142 are of high rigidity and have little elasticity, the cylinder 232 is moved upward by means of hydraulic pressure between the cylinder 232 and the piston 222 (i.e., the telescopic member 242 is expanded), the entire length of the suspension spring 142 is lengthened.
However, the entire length of the suspension spring 141 is shortened since the cylinder 231 moves downward, i.e., the tele5copic member 241 is contracted.

As a result, the suspension spring 142 pushes the lower arm ~2 down relative to the body 2, while the suspension spring 141 pulls the lower arm 41 relative to the body 2. At this moment, said upper arms 61, 62 follow the movement of said lower arms 41~ ~2. However, since the wheels 12~ 11 are normally in contact with the ground, when the respective members are moved in such a manner as described above, the body 2 is finally caused to incline to the left or to the turning center side (the front wheels 11, 12 are also caused to decline) as shown in Fig. 2.
Thus, the vehicle turns in a leaning state as in the case with the motorcycle.

In connection with the above description, it should be noted that since the both ends of said slider 13 are connected to said knuckle arms 101, 12 through said tie rods 121, 122 respectively, according to the movement of the slider 13, the respective knuckles 31~ 32 rotate about king pin axes Kl, K2, and as soon as the body 2 starts inclining as mentioned above, the respective front wheels 11, 11 are steered.

Although the left turn is described in detail in the above, the right turn is also effected in the same manner.

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Fig. 3 through Fig. 10 illustrate a second embodiment of the present invention. In these Figures, like or correspondeing parts with respect to the above mentioned first embodiment are denoted at like numerals. In this embodiment, a hydraulic system adapted to charge and discharge oil into or from a cylinder 23 is different from that of the above described first embodiment. However, there are no other substantial differences between the two ~though, the hydraulic system is not shown), as readily understood when compared with Fig. 3 and Fig. 1. Only minor dlfferences in Fig. 3 are that the upper arm 6 is provided beneath and the tie rod 12 ls provided above, and that the suspension spring 14 is connected to a bracket 15a other than a bracket 9.

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:9 Z9L85~5 Fig. 4 illustrates a hydraulic system employed in this embodiment. The oil charging into the cylinder 23 and the oil discharging therefrom is controlled by means of a controlling valve, or a rotary valve 60 which is actuated in response to the movement of a slider 13. Oil pressurized by a pump 61 is charged into this rotary valve 60. The pump 61 is driven by the engine of the vehicle. When the engine is started, oil in a reservoir tank 62 is sent into a feed pipe 31 by the pump 61 through a cut-off valve 63 and a one way valve 64, and reaches said rotaryvalve 60. And a part of the oil is sent into an accumulator 32 and stored therein. When the pressure within the feed pipe 31 has reached a preset value, a piston 33 of the cut-off valve 63 ls moved to the right in the Figure against a spring 34 in order to isolate the feed pipe 31 from the pump 61, as shown in Fig. 5.
At the same time, oil discharged from said pump 61 is circulated toward an intake side via a by-pass pipe 35. The one way valve 64a ~Fig. 4) provided on the feed pipe 31 serves to 5~i5 prevent tn, press~re (;enerated at the susp~n~io ~-r<~ CaL)irl~ illtO t--,e acclllnulator 32.
~ s ill~lstr-.ted i~ . d and Fic;. 9, th~ r~t~r~
valve G0 corriprise; a cylindrical inner valve 3~i, a cylinrlrical ollter valve 37 contacted wit!l tl~ ~)ut r perii~hery c,f said inner valve 36 and rotata})lv fitte~l thereto relative to each other, ancl a maill l)o-ly COntaininCJ and supl~orting said valves 36 arlc3 37 ~,er~ir for rotation. ~aid inner valve 36 is provide(J with a Eeed oil l~assa~e 4() communicatin~ with saicl feed ~ipe 31 througll arl inlct port 39 an~ a waste oil l~assage 43 comlnunicatir~J with a return r~e 42 (re~er lo Fi(3. 4) through an outlet port 41. ~hes~ feed oil pdssa(Je 40 arld waste ~ as6age 43 are, as a~arent from Fi~. 3 and Fig. 9, communicated with a feed oil port 44 and a waste oil port 45, respectively, which are o~)ened up in the ~-eri~hery of sai(l inrler valve 36 by di-,pl~lci~J in the circumferential direction and the axial clirection with resl~ect Lo each other.
Said outer valve 37 is formed with a feed oil hole 46 allcl a ~/aste oil hole 47 in L~o,itions in agreelli~rlt witrl said ~ced oil L)ort 44 and sai(l waste oil port 45, respectively, in the axial direction. These i~oth }loles 46 and 47 are arranged on a common generatillg line Gf a ~6~
cylinc3er. In other worcls, ~eq~ are arLan~Je(l ~ithil~ a - plane incluciing t}le rotary axial line of said outer valve 37. Tlle m.lill l,ody 3~3 is provi~u-l .,itl 1~485~;5 l~a~iC;~ 4~ c~ frontir,~, said oi l hole 4~ arld .;.~id ~/a~ite oi.l ho]e~ ~7. ~aid oil ~assd(Je 4~ is communicated ~lth the cylind~r 23 of ~ id telescopic rner"~er 24 thr~
a cut-off valve 49.
Said cut-off valve 49 incllldes a piston 51 ~:)iased by nleans of a spring 50. Wherl the enyine i5 'it L~ ec~
and no hydraulic L~ressure exists wi~-llin tl-le feed pi,~e 31, said cut-off va]ve 49 f;erves, as sllowrl in F~i~3. l"
to isolate the oil passage 4~ from the cylindel- 23 in order to prevent the oil from escapirlcj froll, the c~lind~r 23 and thereby to preverlt the hody 2 frolll sirll~in~J.
When the enyine is started and the oil pressure is (~enerated within the fee~ pi.pe 31, OWill(J to the hydraulic pressure, the piston 51 cornpresses the sprin(J
50 for distortion and allows the oil passage 4~ to comlnunicate with the cylinder 23.
As shown in Fiq. 4 and in Fig. 10 as will ~e cle~cri~ed hereinafter, the inner valve 3~ is connectcd to a slider 13 through a lever portion piece 52 and rotated in accordance with the reciprocal movelnent of \~6~6R
~: said ~lider 13. On thc o~hcr harld, the outer valve 37 is connected to a piston 22 side of said telescopic member 24 through a lever portion piece 53 and rotated relative to said inner valve 36 in accordance witll the movement of said pistoll 22 ~movement relative to the vehicle l)ody. This definition remains unchan~3ed ~Jhen used hereinafter) anA conducts a feed ~ack opercltioll.

~.1 lZ~3565 The return pipe 42 connected to said outlet port 41 of the rotary valve 60 is further connected, as shown in Fig. 4, to a reservoir tank 62. Intermediate the feed pip 31 and the return pipe 42 provided is a safety valve 54 adapted to release oil within the feed pipe 31 to the reservoir tank 62. Fig. 4 illustrates a state similar to Fig. 1 when the vehicle is running straight forward. The rotary valve 60 is in its neutral position wherein the feed hole 46 and the waste oil hole 47 of the outer valve 37 are positloned intermediate the feed oil port 44 and the waste oil port 45 of the inner valve 36 in the circumferential direction. The afore-mentioned Fig. 9 also illustrates such a neutral state as ~ust mentioned before.

Flg. 6 lllustrates one state of a left side ~rlght side in the Figure) suspension spring 14 and a rotary valve 60 at a time when a vehicle is turning right. When the vehicle is turnlng right, a slider 13 is moved left as shown by an arrow b, and an inner valve 36 connected to said slider 13 through a lever 20 portion piece 52 is pivoted clockwise in the Figure. Accord-ingly, the feed oil port 44, which was spaced apart from the feed oil port 46 at the time when the vehicle is running in a straight line, is brought to be in alignment with the feed oll hole 46.
As a result, the pressurized oil in the feed pipe 31 is fed into 25 the cylinder 23 to push down the piston 22. In accordance with the movement of the piston 22, an outer valve 37 connected thereto through a lever portion piece 53 is pivoted clockwise.
Although the feed oil hole 46 iS brought to be spaced apart from the feed oil port 44, since the feed oil port 44 is also pivoted clockwise while the slider 13 is moving, the aligning state between the feed oil hole 46 and the feed oil port 44 ls maintained, and the piston 22 is kept moving. In other words, the telescopic member 24 is being expanded and the entire length of the suspension spring 14 is continuously increased. When the movement of the slider 13 is stopped, as shown in Fig. 7, the feed oil hole 46 iS in a spaced apart state with respect to the - lZ~8S~iS

feed oil port 44. Accordingly, the expansion of the telescopic member 24 is stopped as well, and the entire length of the suspension spring 14 is maintained in such a length as to ccrrespond to the moving amount of the slider 13, i.e., the steering amount.

Simultaneously, in the right side rotary valve 60, the waste oil port 45 and the waste oil hole 47 are in alignment with respect to each other. Accordingly, oil in the cylinder 23 is discharged into the return pipe 42 through the waste oil passage 43, and the outlet port 41. And in the same manner as described in the foregoing, the entire length of the suspension spring 14 ls contracted correspondlng to the steering amount, and the suspension spring 14 is maintained in this length.

As a result, as already described with respect to Fig.
1 and Flg. 2, the vehicle body is caused to decline to the right or toward the turnlng center side, and brought to a leaning state similar to a motorcycle.

Fig. 10 is a perspectlve view more reallstlcally lllustrating the structures of the above various devlces, whereln like numerals denote like parts as before. In Fig. 10, the steering shaft 19 and the slider 13 are connected with respect to each other through a llnk mechanlsm instead of the rack and the pinlon. More specifically, the arm 55 secured to the steering shaft 19 is connected to the arm 56 pivotally secured to the vehicle body through a link 57, and the oscillating movement as shown by an arrow c of the arm 56 is converted to a reciprocal movement of the slider 13 through the sllder 59 engaged with the slide rod 58 provided on said arm 56.

The pump 61 and the reservoir tank 62 (not shown in Fig. 10) juxtaposed thereto are disposed in lower posltions than the rotary valve 60 is returned to the reservoir tank 62 by gravity through the return plpe 42. Consequently, as shown in , .;!~.

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Fig. 8 and Fig. 9, the outlet port 41 is formed larger in its diameter than that of the inlet port 39, and the return pipe 42 is constituted with tubular material also having a large bore diameter compared with that of the feed pipe 31.

In the present embodiment, althou~h the suspension spring 14 is expanded and contracted in accordance with the movement of the slider 13, the slider 13 merely actuates the inner valve 36 of the rotary valve 60 and the reaction force of the suspension spring 14 is not transmitted to the slider 13.
Instead, only reaction force which the front wheel 1 receives from the earth ls transmitted to the slider 13, and this reaction force is transmitted to the steering wheel 20. Accordingly, a satisfactory steerlng sense can be obtained.

Although in the above respective embodiments, the present invention is applied to the double wishbone type suspension apparatus, it may also be applied to other types of suspension apparatuses. Also, instead of the steering wheel 20, a bar handle may be employed. Furthermore, the present invention may of course be applicable to other vehicles, such as automobiles. As discussed ln the foregoing, many other modifications can be made.

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Claims (2)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A suspension apparatus for a vehicle provided between a pair of left and right wheels of the vehicle and the vehicle body, comprising telescopic members integrally connected to suspension springs and expanded and contracted by means of fluid pressure, fluid passages for feeding fluid pressurized by a pump to said telescopic members and discharging the fluid from said telescopic members, controlling valves provided in said fluid passages, each valve having a cylindrical inner valve mem-ber, a cylindrical outer valve member rotatably fitted on said inner valve member and a main body containing and supporting said inner and outer valve members for rotation respectively, means for connecting each said inner valve member to a steering mecha-nism to rotate said inner valve member in accordance with the movement of said steering mechanism, and means for connecting each said outer valve member to one of said telescopic members to rotate said outer valve member in accordance with the movement of said telescopic member relative to the vehicle body, whereby the controlling valves are connected to the steering mechanism and to said telescopic members to control said valves not only with respect to the steering but also with respect to the movement of the telescopic members relative to the vehicle body so that the vehicle body is caused to decline toward turning center side due to telescopic movement of said telescopic members in accordance with a steering operation.

2. A suspension apparatus according to claim 1 said means for connecting each inner valve member to a steering mecha-nism is a first lever portion piece formed on said inner valve member which is directly connected to a moving bar of the steer-ing mechanism; and wherein said means for connecting each outer valve member to one of said telescopic members is a second lever portion piece formed on said outer valve member which is directly connected to a piston side member of said one of said telescopic members.