JP4011769B2 - Bottom link type front wheel suspension system for motorcycles - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a bottom link type front wheel suspension device for a motorcycle.
[0002]
[Prior art]
In general, a telescopic type and a bottom link type are adopted for a front wheel suspension device of a motorcycle.
The telescopic method is a method in which the front wheels and the vehicle body frame are directly connected by a shock absorber. When the telescopic front wheel suspension is used in a large motorcycle, a large stroke buffer is used to obtain a large lifting stroke of the front wheel, and the buffer becomes large. In order to use a shock absorber with a small stroke, the bottom link type, which can reduce the stroke of the shock absorber with respect to the lift stroke of the front wheel by using a link, is relatively advantageous.
[0003]
As a bottom link type front wheel suspension device for a motorcycle, for example, Japanese Utility Model Publication No. 60-15744, “Front Wheel Suspension Device for Motorcycles” is known. The conventional bottom link type front wheel suspension system includes a leading arm system shown in FIG. 1 of the publication (hereinafter referred to as “Prior Art 1”) and a trailing arm system shown in FIG. "Conventional technology (2)").
[0004]
In the prior art {circle around (1)}, the rear end of the leading arm 3 is connected to the lower part of the front fork F (the reference is quoted in the publication), and the front end of the leading arm 3 is connected to the front end. It is disclosed that wheels W are attached. Further, it is disclosed that the rear end of the control lever 6 is connected to the front end of the lower bridge Fb, and the front end of the control lever 6 and the front end of the upper bridge Fa are connected by a shock absorber A. For this reason, the shock absorber A protrudes in front of the front fork F. Further, it is disclosed that the control lever 6 and the leading arm 3 are connected by a link 8 in the middle of the longitudinal direction.
[0005]
The prior art {circle around (2)} discloses that the front end of the leading arm 3 is connected to the lower portion of the front fork F, and the front wheel W is attached to the rear end of the leading arm 3. Further, it is disclosed that the front end of the control lever 6 is connected in the middle of the front fork F, and the rear end of the control lever 6 and the front end of the upper bridge Fa are connected by a shock absorber A. For this reason, the upper half of the shock absorber A protrudes in front of the front fork F. Further, it is disclosed that the control lever 6 and the leading arm 3 are connected by a link 8 in the middle of the longitudinal direction.
[0006]
[Problems to be solved by the invention]
In the prior art {circle around (1)}, the shock absorber A protrudes in front of the front fork F as described above, so that a space for disposing the shock absorber A in front of the front fork F is required. For this reason, in order to arrange a headlamp and a meter in front of the front fork F, there is a design restriction, which is not convenient. The same applies to the conventional technique (2).
Although it is conceivable to arrange the shock absorber A behind the front fork F, since there is a fuel tank or the like behind, there is still a design restriction.
[0007]
Accordingly, an object of the present invention is to provide a bottom link type front wheel suspension device in which auxiliary machines such as a headlamp and a meter can be easily arranged in front of a front fork.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, the first aspect of the present invention provides a steering stem rotatably attached to a head pipe, and a top bridge and a bottom bridge are attached to the upper and lower portions of the steering stem, and the top end of the front fork is attached to these top and bottom bridges. The front wheel support arm is connected to the lower end of the front fork, the rod lower end is connected to the front wheel support arm, and the rod can be swung up and down forward from the bottom bridge to the upper end of the rod. connecting the arms extending, by connecting the lower end of the damper to the arm, for connecting the upper end of the shock absorber to the top bridge side, it constitutes a bottom link type front wheel suspension device, the rear end of the arm To the bottom of the bottom bridge below the steering stem and the front end of the arm to the bottom of the shock absorber. In the front fork is arranged in front of the steering stem, characterized in that substantially coincide with the center of the damper in a side view in the center of the front fork.
[0009]
In the bottom link type front wheel suspension device, the arm extends swingably forward from the bottom bridge, and the shock absorber has a lower end connected to the arm and an upper end connected to the top bridge. Furthermore, a front fork is disposed in front of the steering stem in a side view, and the center of the shock absorber substantially coincides with the center of the front fork in a side view.
Therefore, the shock absorber does not protrude forward of the front fork in the arm swing angle range. As a result, there is a space in front of the front fork. Auxiliary equipment such as headlamps and meters may be arranged in this empty space.
According to a second aspect of the present invention, the front end of the front wheel support arm is connected to the lower end of the front fork, the lower end of the rod is connected to the middle of the front wheel support arm extending rearward and downward, and the front wheel is attached to the rear end of the front wheel support arm. It is characterized by that.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the accompanying drawings. Note that “front”, “rear”, “left”, “right”, “upper”, and “lower” follow the direction seen from the driver. The drawings are to be viewed in the direction of the reference numerals.
FIG. 1 is a side view of the front half of a motorcycle according to the present invention.
In the motorcycle 1, a vertical steering stem 4 is attached to a head pipe 3 of a vehicle body frame 2 so as to be rotatable left and right. A top bridge 11 described later is attached to an upper portion of the steering stem 4, and a bar handle 5 is attached to the top bridge 11. Further, a bottom link type front wheel suspension device 10 is attached to the steering stem 4.
The front brake 50 of the motorcycle 1 is a hydraulic disc brake including a brake disc 51 attached to a side portion of the front wheel 32 and a caliper 56 for controlling the braking of the brake disc 51. 61 is a headlamp.
[0011]
FIG. 2 is a side view of the front wheel suspension apparatus according to the present invention.
The front wheel suspension device 10 includes a top bridge 11 attached to the upper portion of the steering stem 4, a bottom bridge 12 attached to the lower portion of the steering stem 4, and a front fork 13 having upper end portions attached to these top / bottom bridges 11, 12. And a front wheel support arm 14 having a front end connected to a lower end of a front fork 13 extending downward and downward, and a front wheel support arm 14 extending rearward and downward, and a lower end connected to a front swing support arm 14 extending rearward and downward. In order to connect the rod 15 and the upper end of the rod 15 extending upward via the rod hanger 16, the arm 17 extends so as to be able to swing up and down from the bottom bridge 12, and the shock absorber 18 has the lower end connected to the arm 17. And attached to the upper part of the front fork 13 to connect the upper end of the shock absorber 18 extending upward. Consisting Tsu Pas bracket 19. a suspension system of trailing arm type. In the figure, reference numerals 21 to 25 denote connecting pins.
[0012]
Because of the trailing arm system, the front wheel axle 31 is attached to the rear end portion of the front wheel support arm 14, and the front wheel 32 is rotatably attached to the axle 31.
The front wheel support arm 14 employs a bolting method referred to as “split tightening” in order to attach the axle 31 without looseness. Split tightening is a method in which a split groove (slit) 14 a extending to a hole for fitting the axle 31 is formed in the front wheel support arm 14, and a portion of the split groove 14 a is tightened with a bolt 27. Although this figure shows that the left front wheel support arm 14 is attached by split tightening, the same applies to the right front wheel support arm (not shown).
[0013]
The front wheel suspension device 10 has (1) the front fork 13 disposed in front of the steering stem 4 in a side view, and the inclination angle of the front fork 13 set to be gentler than the inclination angle of the steering stem 4; (2) The center O ₂ of the shock absorber 18 is substantially aligned with the center O ₁ of the front fork 13 in a side view.
The shock absorber 18 is a spring exterior shock absorber including a hydraulic damper 41 and a suspension spring 42 wound around the damper 41. As apparent from FIG. 2, the outer diameter of the suspension spring 42 which is the maximum diameter of the shock absorber 18 is substantially equal to the diameter of the front fork 13.
[0014]
The axle 31 is provided with a bracket 52 orthogonal to the axle 31 attached so as to be able to swing up and down. The bracket 52 includes a first bracket 53 attached to the axle 31 and a second bracket 54 attached to the tip of the first bracket 53. The second bracket 54 is a member that attaches the caliper 56 and the front fender 62 to the front end side of the second bracket 54 via the torque transmission link 55 and is connected to the middle portion of the front fork 13. The torque transmission link 55 is a rotation stop link that prevents rotation of a link member, for example, the bracket 52, whose both ends are connected to each other by connection pins 57 and 58 so as to be swingable up and down.
[0015]
FIG. 3 is an exploded side view of the front wheel suspension device according to the present invention, and shows the connection relationship of each member in the front wheel suspension device 10.
In this figure, in particular, a connecting portion 12 a is provided at the lower end of the bottom bridge 12, and a rear end connecting portion 17 a of an arm 17 (also referred to as “crank”) is connected to the connecting portion 12 a so as to be able to swing up and down. It shows that the lower end portion 18a of the shock absorber 18 is connected to the front end connecting portion 17b so that it can swing up and down, and the upper connecting portion 16b of the rod hanger 16 is connected to the intermediate connecting portion 17c of the arm 17 so that it can swing up and down. The intermediate connecting portion 17c is provided in the middle of the arm 17 in the longitudinal direction and higher than the front end connecting portion 17b.
This figure also shows that the split groove 14a of the front wheel support arm 14 is cut out to the fitting hole 14b for fitting the front wheel axle.
[0016]
FIG. 4 is a perspective view of a front wheel suspension device according to the present invention. A front fork 13 pipe (front fork pipe) 13a, a front wheel support arm 14, a rod 15 and a shock absorber 18 which are constituent members of the front wheel suspension device 10 are shown in FIG. Indicates that there is one on each side. The top / bottom bridges 11 and 12 have a substantially U-shape in plan view so as not to interfere with the left and right shock absorbers 18 and 18. The first and second brackets 53 and 54 and the torque transmission link 55 are also provided on the left and right sides, respectively. The left and right torque transmission links 55 and 55 are slightly curved toward the center of the vehicle body so as not to interfere with the rods 15 and 15. The torque transmission links 55 and 55 may have a straight structure as long as they do not interfere with the rods 15 and 15.
[0017]
FIG. 5 is a front view of the main part of the front wheel suspension device according to the present invention, showing that the front wheel suspension device 10 is symmetrical with respect to the vehicle body center CL.
The rod hanger 16 has a substantially inverted Y-shape when viewed from the front, in which left and right rod mounting portions 16a and 16a into which the upper ends of the rods 15 and 15 are screwed and a central upper connecting portion 16b connected to the arm 17 are integrally formed. It is a member.
The arm 17 is a single member that connects the lower end portions 18 a and 18 a of the left and right shock absorbers 18 and 18.
The upper bracket 19 is a member that spans between the left and right front fork pipes 13 a and 13 a below the top bridge 11. Damper rods 45, 45 that are upper ends of the shock absorbers 18, 18 are swingably suspended from the upper bracket 19 via upper cushion members 43, 43 and lower cushion members 44, 44 such as rubber. By lowering, the shock absorbers 18 and 18 can be connected to the top bridge 11 side. That is, the shock absorbers 18 and 18 are not directly connected to the top bridge 11 but are connected to the top bridge 11 via the upper bracket 19. The shock absorbers 18 and 18 may be directly connected to the top bridge 11.
[0018]
FIG. 6 is a plan cross-sectional view of the front wheel support arm according to the present invention, which is developed with reference to each connecting portion.
In this figure, the front end portions (one end portion) of the front wheel support arms 14, 14 are connected to the front forks 13, 13 by connecting pins 21, 21, and the rods 15, 15 are connected to the intermediate portion of the front wheel support arms 14, 14. It shows that the axles 31 are spanned between the rear end portions (the other end portions) of the front wheel support arms 14 and 14 by connecting the pins 22 and 22, and the first brackets 53 and 53 are attached to the axle 31.
[0019]
Next, the operation of the front wheel suspension device 10 configured as described above will be described with reference to FIGS. FIG. 7 is an operation diagram (part 1) of the front wheel suspension device according to the present invention, and shows a state of the front wheel suspension device 10 when a downward load is not applied to the front wheel 32.
The front wheel 32 is at the lower limit level, and the arm 17 at this time is at the lower limit position D shown in the figure. As a result, the shock absorber 18 is in the most extended state. The front side surface of the shock absorber 18 is substantially flush with the front side surface of the front fork 13.
[0020]
FIG. 8 is an operational view (No. 2) of the front wheel suspension device according to the present invention. The state of the front wheel suspension device 10 when the front wheel 32 is at an intermediate level, that is, the shock absorber 18 is contracted to some extent from the state of FIG. It shows that.
When a downward light load about the weight of the motorcycle 1 acts on the vehicle body frame 2, the light load is generated by the head pipe 3, the steering stem 4, the top / bottom bridges 11, 12, the front fork 13, the front wheel support arm 14, and the axle 31. → It is transmitted to the road surface F along the route of the front wheel 32. The reaction force from the road surface F is transmitted to the shock absorber 18 through the path of the front wheel 32 → the axle 31 → the rod 15 → the rod hanger 16 → the arm 17.
As a result, the front wheel support arm 14 swings slightly upward from the state shown in FIG. 7, and the rod 15 and the rod hanger 16 are raised, so that the front end of the arm 17 swings upward. Shrink by the corresponding stroke. The front side surface of the shock absorber 18 at this time is substantially the same surface as the front side surface of the front fork 13.
[0021]
FIG. 9 is an operation view (No. 3) of the front wheel suspension device according to the present invention, showing the state of the front wheel suspension device 10 when the front wheel 32 is at the upper limit level, that is, the state where the shock absorber 18 is most contracted.
When a downward heavy load acts on the vehicle body frame 2, this heavy load is transmitted to the road surface F through the same route as that shown in FIG. A reaction force from the road surface F is transmitted from the front wheel 32 to the shock absorber 18. As a result, the rear portion of the front wheel support arm 14 swings further upward, and the rod 15 and the rod hanger 16 are raised, so that the front end portion of the arm 17 swings upward to the upper limit position U. Shrink by the corresponding stroke. The front side surface of the shock absorber 18 at this time is substantially the same surface as the front side surface of the front fork 13.
[0022]
As is clear from the above description, the front wheel suspension device 10 extends the arm 17 forwardly from the bottom bridge 12 so as to be able to swing up and down in a side view, and connects the lower end portion of the shock absorber 18 to the arm 17. This part is connected to the upper bracket 19 on the top bridge 12 side. In FIG. 9, the arm 17 swings up and down by a swing angle θ within a range between a lower limit position D indicated by an imaginary line and an upper limit position U indicated by a solid line. When the arm 17 swings, the shock absorber 18 swings back and forth with respect to the upper bracket 19.
[0023]
By the way, the center of the shock absorber 18 is set to substantially coincide with the center of the front fork 13. Moreover, the outer diameter of the suspension spring 42, which is the maximum diameter of the shock absorber 18, is set to be approximately equal to the diameter of the front fork 13. Further, when the shock absorber 18 is most contracted, the arm 17 is at the upper limit position U in a direction substantially orthogonal to the front fork 13 in a side view. Therefore, the shock absorber 18 does not protrude to the front of the front fork 13 in the swing angle θ range of the arm 17, that is, in the elevation range of the front wheel 32.
[0024]
FIG. 10 is an exploded side view showing a modified example of the front wheel suspension apparatus according to the present invention.
The front-wheel suspension device 10 of this modification is characterized in that the arm 17 is mounted upside down among the components shown in FIG. Even in this case, the basic operation is the same as that of FIG. Each structural member of the modification has the same configuration as each structural member shown in FIGS. 1 to 9 and is given the same reference numeral, and description thereof is omitted.
[0025]
In the embodiment of the present invention, (1) the front wheel suspension device 10 may be a bottom link type device, and may have a leading arm type configuration in addition to the trailing arm type configuration. . In the case of the leading arm method, the front wheel support arm 14 may be attached to the lower end portion of the front fork 13 in the reverse direction.
(2) It is arbitrary to make the front wheel suspension device 10 symmetrical with respect to the vehicle body center CL.
(3) The type and size of the shock absorber 18 are arbitrary. Further, the number of shock absorbers 18 is not limited to two on the left and right, and may be one. In that case, it is preferable to arrange one shock absorber 18 in the center of the vehicle body. Further, whether or not the outer diameter of the suspension spring 42 of the shock absorber 18 is made equal to the diameter of the front fork 13 is arbitrary.
[0026]
(4) The rod hanger 16 may be any member as long as it attaches the rods 15 and 15 and is connected to the arm 17 so as to be able to swing up and down. Moreover, the attachment structure of each rod 15 and 15 with respect to the rod hanger 16 is arbitrary. In addition to screwing, for example, it may be attached by welding or caulking, or may be formed integrally with the rod hanger 16.
(5) The left and right rods 15, 15 may be directly connected to the arm 17 without providing the rod hanger 16.
(6) The front brake 50 may be provided on both the left and right sides of the front wheel 32 or only on either the left side or the right side. When only one side is provided, the brake disc 51 is provided only on one side.
[0027]
【The invention's effect】
The present invention exhibits the following effects by the above configuration.
Claim 1 is a bottom link type front wheel suspension device, wherein the arm is extended forward from the bottom bridge so as to be able to swing up and down, the lower end portion of the shock absorber is connected to the arm, and the upper end portion of the shock absorber is connected to the top bridge side, Since the front fork is placed in front of the steering stem in side view and the center of the shock absorber is substantially aligned with the center of the front fork in side view, the shock absorber can be placed so as not to protrude to the front of the front fork. it can. As a result, it is possible to provide an empty space in front of the front fork, and by using this empty space, it is possible to easily arrange auxiliary equipment such as a headlamp and a meter in front of the front fork. In addition, since the shock absorber does not protrude in front of the front fork, the appearance of the motorcycle is enhanced.
According to a second aspect of the present invention, the front end of the front wheel support arm is connected to the lower end of the front fork, the lower end of the rod is connected to the middle of the front wheel support arm extending rearward and downward, and the front wheel is attached to the rear end of the front wheel support arm It was.
[Brief description of the drawings]
FIG. 1 is a side view of a front half of a motorcycle according to the present invention. FIG. 2 is a side view of a front wheel suspension according to the present invention. FIG. 3 is an exploded side view of a front wheel suspension according to the present invention. FIG. 5 is a front view of a cross section of the main part of the front wheel suspension device according to the present invention. FIG. 6 is a plan sectional view of the front wheel support arm according to the present invention. Operational diagram of such front wheel suspension (part 1)
FIG. 8 is an operation diagram of the front wheel suspension device according to the present invention (part 2).
FIG. 9 is an operation diagram of the front wheel suspension device according to the present invention (part 3).
FIG. 10 is an exploded side view showing a modified example of the front wheel suspension device according to the present invention.
DESCRIPTION OF SYMBOLS 1 ... Motorcycle, 2 ... Body frame, 3 ... Head pipe, 4 ... Steering stem, 10 ... Bottom link type front wheel suspension apparatus, 11 ... Top bridge, 12 ... Bottom bridge, 13 ... Front fork, 14 ... Front wheel support arm, 15 ... rod, 16 ... Roddohanga, 17 ... arm, 18 ... buffer, 19 ... upper bracket, 31 ... front wheel axle, 32 ... front wheel, 61 ... headlamp, O ₁ ... front fork center, O ₂ ... buffer Heart of.

Claims (2)

A steering stem is rotatably attached to the head pipe, and a top bridge and a bottom bridge are attached to the upper and lower parts of the steering stem. An upper end portion of a front fork is attached to the top and bottom bridges, and a front wheel is attached to a lower end portion of the front fork. Connect one end of the support arm, connect the lower end of the rod in the middle of the front wheel support arm, connect the upper end of the rod to the arm that can swing up and down from the bottom bridge, By connecting the lower end of the shock absorber and connecting the upper end of this shock absorber to the top bridge side, a bottom link type front wheel suspension device is configured ,
The rear end of the arm is connected to the lower end of the bottom bridge below the steering stem, the front end of the arm is connected to the lower end of the shock absorber, and a front fork is disposed in front of the steering stem in a side view. A bottom link type front wheel suspension system for a motorcycle, wherein the center of the shock absorber is substantially coincident with the center of the front fork. The front end of the front wheel support arm is connected to the lower end of the front fork, the lower end of the rod is connected to the middle of the front wheel support arm extending rearward and downward, and the front wheel is attached to the rear end of the front wheel support arm. The bottom link type front wheel suspension system for a motorcycle according to claim 1,

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