Title of Invention

LINK TYPE FRONT SUSPENSION STRUCTURE

Abstract

To provide a link type front suspension structure that makes it difficult for a bending moment to act on a push rod conveying expansion and contraction of a front fork to a shock absorber. [Means of Solution] An upper arm 15 rotatably bridges between an upper end of a push rod 14 and the front fork 5, and the length of this upper arm is equal to the length between a linking point of a lower end section of the push rod 14 of the axle support arm and a linking point of the arm holder 6, and is parallel with this length. As a result, a parallelogram link is formed by the front fork 5, the push rod 14, the upper arm 15 and part of the axle support arm 8. [Selected Drawing] Fig. 1.

Full Text

FORM 2 THE PATENTS ACT 1970 [39 OF 1970] COMPLETE SPECIFICATION [See Section 10] "LINK TYPE FRONT SUSPENSION STRUCTURE" HONDA GIKEN KOGYO KABUSHIKI KAISHA, a corporation of Japan, having a place of business at 1-1, Minamiaoyama 2-chome, Minato-ku, Tokyo, Japan The following specification particularly describes the nature of the invention and the manner in which it is to be performed :- The" present invention relates to a link type front suspension structure. The present invention relates to a link type front suspension structure applied to a motorcycle. [0002] [Related Art] A link type front suspension structure having a shock absorbing function not in a front fork but separately from a front fork, in which expansion and contraction of the front fork is conveyed to a shock absorber through a link mechanism, is known from the related art. [0003] Fig. 8 shows a link type front suspension structure of the related art. Specifically, a steering stem 101 is rotatably attached to a head pipe 100, a top bridge 102 is provided on an upper end of this steering stem 101, a bottom bridge 103 is provided on a lower end of the steering stem 101, a front fork 104 is supported by the top bridge 102 and the bottom bridge 103, one end of an axle support arm 105 is connected to a lower end of this front fork 104, and the other end of the axle support arm is connected to an axle 106 of a front wheel. [0004] -2- An upper end of a shock absorber 107 is attached to a cushion upper bracket passed through the front fork 104 and arranged on a lower end of the top bridge 102, a lower end of this shock absorber 107 is attached to a cushion arm 108 having one end pivoted on the bottom bridge 103, a push rod 109 links between the cushion arm 108 and the axle support arm 105, and expansion and contraction of the front form 104 is conveyed to the shock absorber 107 through a link mechanism made up of the axle support arm 105, the push rode 109 and the cushion arm 108. [0005] [Problems to be solved by the invention] With the above described link type front suspension structure of the related art, there is great variation between the direction of expansion and contraction of the front fork and the arrangement direction of the push rod, which means that a bending moment acts on the push rod. as a result, the push rod must have a certain rigidity to take this bending moment into consideration, and this inevitably makes the push rod thicker, and increases the overall weight, A link type front suspension structure having a steering stem rotatabiy attached to a head pipe, a top bridge being provided on an upper end of the steering stem and a bottom bridge provided on a lower end of the steering stem, a front fork supported by the top bridge and bottom bridge, and a lower end of a shock absorber supported by a link mechanism provided on the front fork, wherein the link mechanism is a quadrilateral link mechanism comprising: B an upper link with one end connecting to a middle portion of the front fork; an axle support arm with one end connecting to a lower end of the front fork and the other end connecting to an axle side of a front wheel; a push rod having an upper'end connecting to the other end of the upper link and a lower end connecting to the axle support arm; and a connecting member having a first end connected to a triangular-shaped cushion arm having a first corner rotatabiy secured to said lower end of said shock absorber, the connecting member haying a second end connected to the upper end of said push_rqd.__ With this structure, it is possible to reduce a bending moment acting on the push rod. [0007] Preferably, a side section of the front fork pipe and the upper are link are parallel to a greater extent than a pivot point of the push rod of the axle support arm. As a result, it is possible to completely do away with the bending moment acting on the push rod. [0008] 3 [Brief Description of the Drawings] Fig. 1 is a side elevation of a link type front suspension structure to which the present invention reiates. Fig. 2 is a perspective drawing of the link type front suspension structure to which the present invention relates. Fig. 3 is a side elevation of a link type front suspension structure to which another embodiment relates. Fig. 4 is a side elevation of a link type front suspension structure to which a further embodiment relates. Fig. 5 is an enlarged cross sectional view, looking from direction A - A, of the embodiment shown in Fig. 3. Fig. 6 is a cross sectional view in direction B - B in Fig. 5. Fig. 7 is a drawing similar to Fig. 6 showing another embodiment. Fig. 8 is a side elevation of a link type front suspension structure of the related art. 4 [Embodiments of the Invention] bmbodiments of the present invention will be described below.based on the attached drawings. Fig. 1 is a side elevation of a link type front suspension structure to which the present invention relates, and Fig. 2 is a perspective drawing of the'link'type - front suspension structure to which the present invention relates. *">'" " [0009] A steering stem 2 is inserted into this head pipe 1 so as to be capable of rotation, with a top bridge 3 being provided on an upper end of the steering stem 2 and a bottom bridge 4 being provided on a lower end of the steering stem 2, an upper part of a front fork 5 being supported by the top bridge 3 and bottom bridge 4, and a lower end of the front fork 5 being inserted into an arm holder 6. [0010] Also, one end of an axle support arm (pivot arm) 8 is swingably attached to the axle 7 of the front wheel. The shape of this axle support arm 8 is substantially chevron shaped when viewed from the side, and the other end of the axle support arm 8 is rotatably pivoted at a lower end of the arm holder 6. [0011] Also, an upper end of the shock absorber 10 is rotatably attached to the top bridge via an attachment stay 9, a cushion arm attachment stay 11 is fixed to the front fork 5 so as to overlap the bottom bridge 4, one end of a cushion arm 12 is swingably supported on the cushion arm attachment stay, and a lower end of the shock absorber 10 is rotatably attached to a middle section of the cushion arm 12. [0012] An upper end of a rod shaped connecting member 13 is rotatably linked to the other end of the cushion arm 12, an upper end of a push rod 14 is rotatably linked to a lower end of the connecting member 13, and a lower end of the push rod 14 is rotatably linked to a middle section of the axle support arm 8. [0013] An upper arm 15 rotatably bridges between an upper end of the push rod 14 and the front fork 5; and the length of this upper arm is equal to the length between a linking point of a lower end section of the push rod 14 of the axle support arm and a linking point of the arm holder 6, and is parallel this length. As a result, a parallelogram link is formed by the front fork 5, the push rod 14, the upper arm 15 and part of the axle support arm 8. [0014] Further, one end of an attachment stay 17 for a brake caliper 16 is attached to 5 the front wheel axle 7, a torque link 18 is suspended between the\ other end of the attachment stay 17 and the front fork 5, and a fender 19 is attached fo.tli^ttachfnent stay 17. As described above, when a vehicle wheel moves up and down with the uneveness of the road surface, specifically, if the axle support arm 8 vibrates up and down with a linking point of the arm holder as a center, the push rod 14 constitutes part of the parallelogram link, and so it moves up and down parallel to the front fork 5 and there is no bending moment acting on the push rod 14. [0016] In the present invention, it is not necessary to have a link that is a complete parallelogram, as long as it is almost a parallelogram. In this case also it is possible to substantially reduce a bending moment. [0017] Fig. 3 and Fig. 4 are side elevations showing a link type front suspension structure of other embodiments of the present invention, and the embodiment shown in Fig. 3 has a lower end of a shock absorber 10 linked to a tip end (the left end in the drawing) of a cushion arm 12 that has a triangular shape when viewed from the side, an upper end of a connecting member 13 linked to a middle section of the cushion arm 12, and a rear end of the cushion arm 12 linked to a bottom bridge 4. [0018] The embodiment shown in Fig. 7 has a lower end of a shock absorber 10 linked to a tip end (the left end in the drawing) of a cushion arm 12 having the same triangular shape when viewed from the side as described above, an upper end of a push rod 14 linked to a lower end section of the cushion arm 12, a rear end of the cushion arm 12 linked to the bottom bridge 4, and the connecting member is omitted. [0019] The embodiment shown in Fig. 3 will be described in detail based n Fig. 5 and Fig. 6.Here, Fig. 5 is an enlarged cross sectional view looking from the direction A - A of the embodiment shown in Fig. 3, and Fig. 6 is a cross section in direction B - B in Fig. 5, with elements that are the same as in the previous embodiment having the same reference numerals, and description of these elements is omitted. [0020] A bracket 20 is provided on the bottom bridge 4, a rear end of the cushion arm 12 is rotatably linked to this bracket 20 via a bolt 21 and bearing 22, a lower end of the shock absorber 10 is linked to a tip end section of the cushion arm 12 via a bearing 23, 6 and a connecting member 3 is rotatably linked to a middle section of the cushion arm 12 via a ball bearing 24. [0021] Bolts 25 are inserted into both lower ends of the connecting member 13, upper end sections of the push rods 14 are rotatably linked to these bolts 25 via ball bearing6 26, one end of each of the upper arms 15 is rotatably linked to common bolts 25 via a bearing 27 while bolts 28 are fixed to side surfaces of the front fork 5, and the other end of each of the upper arms 15 is rotatably linked to these bolts 28 via ball bearings 29. [0022] Fig. 7 is a drawing similar to Fig. 6 showing another embodiment, and in this embodiment the connecting member 3 3 is split into left and right halves 13a and 13b.With this type of arrangement, air flow becomes smooth and a cooling effect is improved. > [0023] [Effects of the Invention] According to the present invention as described above, a push rod for conveying movement in response to expansion and contraction of a front fork to a shock absorber is substantially parallel to the front fork, which means that a bending moment acting on the push rod is either made extremely small or alleviated altogether, and the push rod requires less rigidity. As a result, it is possible to make the push rod fine and light in weight. 7- [Description of the numerals] 1. head pipe 2 steering stem 3 top bridge 4 bottom bridge 5 front fork 6 arm holder 7 Iront wheel axle 8 axle support arm (pivot arm) 9,11, 17 attachment stay 10 shock absorber 12 cushion arm 12 connecting member 14 push rod 15 upper arm 16 brake caliper 18 torque ring 19 fender 20 bracket 21,25,28 bolt 23, 24, 26 ball bearing 22,27 bearing 8 WE CLAIM: 1. A link type front suspension structure having a steering stem rotatably attached to a head pipe, a top bridge being provided on an upper end of the steering stem and a bottom bridge provided on a lower end of the steering stem, a front fork supported by the top bridge and bottom bridge, and a lower end of a shock absorber supported by a link mechanism provided on the front fork, wherein the link mechanism is a quadrilateral link mechanism comprising: an upper link with one end connecting to a middle portion of the front fork; an axle support arm with one end connecting to a lower end of the front fork and the other end connecting to an axle side of a front wheel; a push rod having an upper end connecting to the other end of the upper link and a lower end connecting to the axle support arm; and a connecting member having a first end connected to a triangular-shaped cushion arm having a first corner rotatably secured to said lower end of said shock absorber, the connecting member having a second end connected to the upper end of said push rod. 2. The link type front suspension structure as claimed in claim 1, wherein a line connecting a pivot point of the axle support arm push rod and a pivot point of the front fork is substantially parallel to the upper link. 3. A link type front suspension structure substantially as hereinbefore described with reference to figure 1 to 7 of the accompanying drawings. Dated this 31st day of January, 2001

Documents:

105-mum-2001-abstract(12-02-2006).doc

105-mum-2001-abstract(12-02-2006).pdf

105-mum-2001-abstract.doc

105-mum-2001-abstract.pdf

105-mum-2001-cancelled page(24-04-2006).pdf

105-mum-2001-cilams.doc

105-mum-2001-claim(granted)-(24-04-2006).doc

105-mum-2001-claim(granted)-(24-04-2006).pdf

105-mum-2001-claims(cancelled).pdf

105-mum-2001-claims.pdf

105-mum-2001-correspondence(21-04-2006).pdf

105-mum-2001-correspondence(ipo)-(15-04-2006).pdf

105-mum-2001-correspondence(ipo).pdf

105-mum-2001-correspondence.pdf

105-mum-2001-description(granted).doc

105-mum-2001-description(granted).pdf

105-mum-2001-drawing(24-04-2006).pdf

105-mum-2001-drawing.pdf

105-mum-2001-form 1(31-01-2001).pdf

105-mum-2001-form 1.pdf

105-mum-2001-form 13.pdf

105-mum-2001-form 19(21-12-2004).pdf

105-mum-2001-form 1a(02-02-2006).pdf

105-mum-2001-form 1a.pdf

105-mum-2001-form 2(granted)-(24-04-2006).doc

105-mum-2001-form 2(granted)-(24-04-2006).pdf

105-mum-2001-form 2(granted).pdf

105-mum-2001-form 2(title page).pdf

105-mum-2001-form 3(02-02-2006).pdf

105-mum-2001-form 3(31-01-2001).pdf

105-mum-2001-form 3.pdf

105-mum-2001-form 4(27-02-2006).pdf

105-mum-2001-form 4.pdf

105-mum-2001-form 5(31-01-2001).pdf

105-mum-2001-form 5.pdf

105-mum-2001-form-2(granted).doc

105-mum-2001-patent(japanese government).pdf

105-mum-2001-petition under rule 137(02-02-2006).pdf

105-mum-2001-petition under rule 138(02-02-2006).pdf

105-mum-2001-power of attorney.pdf

105-mum-2001-power of authority(02-02-2006).pdf

105-mum-2001-power of authority(21-06-2001).pdf