Double link type suspension system

Abstract

A double link type front suspension system for an automotive vehicle of the front engine front drive type or the four wheel drive type. The suspension system is comprised of upper and lower control arms adapted to connect a steering knuckle to a vehicle body. A shock absorber is disposed .[.generally vertical.]. so that its upper end .[.section.]. is connected to the vehicle body .[.while its.]. .Iadd.and the .Iaddend.lower end .[.section.]. is .[.relatively rotatably.]. .Iadd.pivotally .Iaddend.connected .[.to.]. .Iadd.by way of a joint formed on the upper portion of .Iaddend.the knuckle .Iadd.to either the knuckle itself or the lower end of an intermediate arm which is connected between the .Iaddend.upper .[.section is made around.]. .Iadd.arm and the knuckle. The lower control arm is connected to the knuckle by way of a ball joint. A steering axis is defined by .Iaddend.a .[.straight.]. line (steering axis).]. passing through .[.a.]. .Iadd.the .Iaddend.ball joint .[.for connecting.]. .Iadd.and the joint on the upper portion of .Iaddend.the knuckle .[.lower section and the lower control arm, thereby making possible to set the steering axis regardless of the upper control arm.]..

What is claimed is: 
     
       1. A double link type suspension system for a vehicle, comprising: a knuckle for rotatably supporting a wheel of the vehicle;   a lower control arm having a first end section .[.movable.]. .Iadd.pivotally .Iaddend.connected to a lower section of said knuckle by a first joint, and a second end section .[.movably.]. .Iadd.pivotally .Iaddend.connected to .[.side of.]. a vehicle body;   a shock absorber having a first .[.end.]. section .Iadd.which is .Iaddend.connected to the vehicle body .[.side.]., and a second .[.end.]. section .[.relatively movably.]. .Iadd.operatively .Iaddend.connected to an upper section of said knuckle.[.,.]. .Iadd.by way of a joint means in such a manner that .Iaddend.said .[.shock absorber being.]. .Iadd.knuckle is .Iaddend.relatively rotatable .[.to said knuckle around.]. .Iadd.with respect to said shock absorber about .Iaddend.a straight line passing through said first joint .Iadd.and said joint means.Iaddend.;   an extension member having a first end section.Iadd.and a second end section, the first end section being .Iaddend.connected to .Iadd.one of .Iaddend.said shock absorber.[., and a second end section.]. .Iadd.and said knuckle.Iaddend.; and   an upper control arm having a first end section .[.movably.]. .Iadd.pivotally .Iaddend.connected to the second end section of said extension member, and a second end section .Iadd.pivotally .Iaddend.connected to the vehicle body .[.side.]..   
     
     
       2. A double link type suspension system as claimed in claim 1, wherein said shock absorber is disposed generally vertical and near said extension member. 
     
     
       3. A double link type suspension system as claimed in claim 1, wherein the vehicle is of a front engine front wheel drive type. 
     
     
       4. A double link type suspension system as claimed in claim 1, wherein the vehicle is a four wheel drive type. 
     
     
       5. A double link type suspension system as claimed in claim 1, wherein said wheel has an axle shaft connected through a constant velocity joint to a drive shaft which is driven by an engine, said axle shaft being rotatably journalled by said knuckle. 
     
     
       6. A double link type suspension system as claimed in claim 1, wherein said first joint is a ball joint .[.whose axis is aligned with said straight line.].. 
     
     
       7. A double link type suspension system as claimed in claim 6, wherein said ball joint includes a ball stud secured to said knuckle lower section, said ball stud having an axis aligned with said straight line, and a retainer for movably supporting said ball stud, secured to said lower control arm. 
     
     
       8. A double link type suspension system as .[.calimed.]. .Iadd.claimed .Iaddend.in claim 1, wherein .[.said knuckle upper section and said shock absorber second end section are connected by a second joint through which said straight line passes, and.]. said extension member second end section and said upper control arm first end section are connected by a third joint, said third joint being .[.separate from.]. .Iadd.located between .Iaddend.a vertical plane containing a point .[.in a horizontal plane passing through said third joint, said straight line passing through said point, said third joint being located between said vertical plane containing said point.]. .Iadd.which lies on said straight line .Iaddend.and a wheel vertical plane containing center line of said wheel and perpendicular to axis of rotation of said wheel. 
     
     
       9. A double link type suspension system as claimed in claim 8, wherein said straight line serves as a steering axis. 
     
     
       10. A double link type suspension system as claimed in claim 8, wherein said point resides in said upper control arm and separate from said third joint. 
     
     
       11. A double link type suspension system as claimed in claim 10, wherein said straight line intersects said wheel vertical plane at a point above a horizontal plane at which said wheel is in contact with road surface. 
     
     
       12. A double link type suspension system as claimed in claim 11, wherein said straight line intersects said horizontal plane at a point outside of said wheel vertical plane in a lateral direction of the vehicle body. 
     
     
       13. A double link type suspension system as claimed in claim 1, wherein said knuckle upper section is rotatably connected to said extension member first end section to which said shock absorber second end section is connected. 
     
     
       14. A double link type suspension system as claimed in claim 13, wherein said shock absorber second end section is connected through an elastomeric bushing to said extension member first end section. 
     
     
       15. A double link type suspension system as claimed in claim 13, wherein second joint includes a joint bracket fixedly secured to said extension member first end section, a rod member secured to said bracket, a sleeve member mounted on said rod member, means defining a through-hole in said knuckle upper section, said sleeve member being situated within said through-hole, and annular ball bearings disposed between said sleeve and said knuckle upper section. 
     
     
       16. A double link type suspension system as claimed in claim .[.1.]. .Iadd.3.Iaddend., wherein said third joint includes a rod member fixedly secured to said extension member second end section, and first and second elastomeric bushings securely mounted on said rod member and located on the opposite sides of said extension member second end section, said upper control arm first end section being mounted on said elastomeric bushings. 
     
     
       17. A double link type suspension system as claimed in claim 16, wherein said upper control arm first end section has first and second cylindrical portions which are respectively mounted on said first and second elastomeric bushings. 
     
     
       18. A double link type suspension system as claimed in claim 1, wherein said suspension member .[.is.]. .Iadd.has a .Iaddend.generally channel-shaped .Iadd.cross-section .Iaddend.and is disposed to .[.surround at least.]. .Iadd.enclose .Iaddend.part .[.of periphery.]. of said shock absorber. 
     
     
       19. A double link type suspension system as claimed in claim 18, wherein said extension member is formed of a press-formed sheet metal and includes a generally vertically extending base plate portion located between said shock absorber and said wheel, and first and second side plate portions integral with said base portion and extending along said base portion, said base plate portion and first and second side plate portions defining an elongate space in which at least a part of said shock absorber is positioned. 
     
     
       20. A double link type suspension system as claimed in claim 1, wherein said straight line intersects said wheel vertical plane at a point on a horizontal plane at which said wheel is in contact with road surface. 
     
     
       21. A double link type suspension system as claimed in claim 8, wherein said second joint includes a support bracket to which said shock absorber second end section is fixedly secured, and first and second ball joints disposed between said support bracket and said knuckle upper section, axes of said first and second ball joints being aligned with each other and aligned with said straight line. 
     
     
       22. A double link type suspension system as claimed in claim 21, wherein each ball joint includes a ball stud secured to said support bracket, and a retainer .[.for movably supporting.]. .Iadd.pivotally mounted on .Iaddend.said ball stud, .Iadd.the retainer being .Iaddend.secured to said knuckle upper section, .Iadd.and wherein the .Iaddend.axes of .Iadd.the .Iaddend.ball studs of said first and second ball joints .[.being.]. .Iadd.are .Iaddend.aligned with each other and aligned with said straight line. 
     
     
       23. A double link type suspension system as claimed in claim 22, wherein said support bracket has first and second flange sections which are spaced from each other so that a part of said knuckle upper section is interposed therebetween, said ball studs of said first and second ball joints being fixedly secured respectively to said first and second flange sections. 
     
     
       24. A double link type suspension system as claimed in claim 1, wherein said first end section of said extension member is fixedly secured to an outer tube of said shock absorber. 
     
     
       25. A double link type suspension system as claimed in claim 8, wherein said second joint includes a support bracket to which said shock absorber second end section is fixedly secured, a rod member secured to said support bracket, means defining a through-hole in said knuckle upper section, said rod member passing through said through-hole, and first and second annular ball bearings disposed between said support bracket and said knuckle upper section and coaxial with said rod member, said first and second annular ball bearings being separate from each other. 
     
     
       26. A double link type suspension system as claimed in claim 8, wherein said third joint is situated above the outer peripheral surface of said wheel. 
     
     
       27. A double link type suspension system as claimed in claim 8, wherein said second joint includes a support bracket to which said shock absorber second end section is fixedly secured, a rod member fixedly secured to said support bracket, a cylindrical sliding bearing mounted on said rod member, a part of said knuckle upper section being mounted on said sliding bearing. 
     
     
       28. A double link type suspension system as claimed in claim 27, wherein said sliding bearing is a plastic bushing. 
     
     
       29. A double link type suspension system as claimed in claim 8, wherein said extension member first end section is formed with a cylindrical portion fitted on an outer tube of said shock absorber. .Iadd. 
     
     
       30.  A double link type suspension as claimed in claim 1, wherein said joint means comprises: a second joint which is formed on said knuckle and which provides a pivotal connection between the knuckle and the second end section of said extension member; and   a pivot connection which interconnects the second end section of said shock absorber and the second end section of said extension member at a location proximate said second joint. .Iaddend. .Iadd.31. A double link suspension system for a vehicle, comprising:   a knuckle on which a road wheel is rotatably supportable;   a first joint;   a lower control arm having an outboard section pivotally connected to a lower section of said knuckle by said first joint, and an inboard end section adapted for pivotal connection to a vehicle body;   a shock absorber, said shock absorber having a connection member adapted for connection to the vehicle body;   an upper control arm having an inboard end and an outboard end, the inboard end being adapted for pivotal connection to said vehicle body;   an extension member having a first end and a second end, the first end being pivotally connected to the outboard end of the upper arm, the second end being connected to said shock absorber; and   a second joint, said second joint pivotally connecting an upper section of said knuckle to one of said shock absorber and the second end of said extension member, said first and second joints being arranged such that said knuckle is pivotal with respect to said extension member about an axis which passes through the first and second joints. .Iaddend.   
     
     
        .Iadd.     A double link suspension system for a vehicle, comprising: a knuckle on which a road wheel is rotatably supportable;   a lower control arm having an outboard section which is pivotally connected to a lower section of said knuckle by a first joint, and an inboard end section which is adapted for pivotal connection to a vehicle body;   an extension member having an upper end and a lower end, the lower end being pivotally connected to said knuckle by a second joint, the first and second joints being arranged such that said knuckle is pivotal about an axis which passes through the first and second joints;   an upper control arm having an outboard end which is pivotally connected to the upper end section of said extension member, and an inboard end section which is adapted for pivotal connection to said vehicle body; and   a shock absorber having an upper end which is adapted for connection to the vehicle body, and a lower end which is pivotally connected to the lower   
     
     
        end section of said extension member. .Iaddend. .Iadd.33.  A double link suspension system for a vehicle, comprising: a knuckle on which a road wheel is rotatably supportable;   a lower control arm having an outboard end which is pivotally connected to a lower section of said knuckle by a first joint, and an inboard end which is adapted for pivotal connection to a vehicle body;   a shock absorber having an upper end which is adapted for connection to the vehicle body, and a lower end section operatively connected to an upper section of said knuckle by a second joint in such a manner that said knuckle is relatively rotatably with respect to said shock absorber about a straight line passing through said first joint and said second joint;   an extension member having first end and a second end, the first end being rigidly connected to said shock absorber; and   an upper control arm having an outboard end which is pivotally connected to the second end of said extension member, and an inboard end which is adapted for pivotal connection to said vehicle body. .Iaddend. .Iadd.34. A double link suspension system for a vehicle, comprising:   a knuckle;   means for rotatably supporting a road wheel on said knuckle;   means defining a first joint on a lower portion of said knuckle;   means defining a second joint on an upper portion of said knuckle;   a lower control arm having an outboard section which is pivotally connected to the lower section of said knuckle by said first joint, and an inboard end section which includes means for pivotally connecting the inboard end to a vehicle body;   an extension member having an upper end and a lower end, the lower end being pivotally connected to said knuckle by said second joint, the first and second joints being arranged such that said knuckle is pivotal with respect to said lower control arm and said extension about an axis which passes through the first and second joints;   an upper control arm having an outboard end which is pivotally connected to the upper end section of said extension member, and an inboard end section including means for pivotally connecting the inboard end to a vehicle body; and   a shock absorber having an upper end which includes means for connecting the upper end to a vehicle body, and a lower end which is pivotally connected to the lower end section of said extension member. .Iaddend.   
     
     
        .Iadd.35.  A double link suspension as claimed in claim 34 wherein said extension member has a channel shaped cross-section and said shock absorber is disposed in such a manner as to be partially enclosed by said extension member. .Iaddend.