JP2938903B2 - Motorcycle front wheel suspension - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a double wishbone type front wheel suspension for a motorcycle.

2. Description of the Related Art A conventional front wheel suspension of a motorcycle is disclosed, for example, in Japanese Patent Publication No. 58-49435.

To explain this, a body frame is composed of a pair of left and right main frames located outside the engine supported by the body frame, and a steering frame that projects forward and upward from these main frames and whose protruding end supports a head pipe. A steering knuckle is provided in front of the vehicle body frame to support the front wheels, and the rear ends of the lower arm and the upper arm, which are vertically separated from each other, are pivotally supported by the vehicle body frame. The steering knuckle is steerably pivoted, and a shock absorber is provided which extends long in the forward downward direction, has a rear end pivotally supported by the body frame, and a front end pivotally supported by the lower arm, and is supported by the head pipe. The steering knuckle is interlocked to the steering wheel.

(Problems to be solved by the invention) By the way, according to the above-mentioned conventional technology, there are the following problems.

That is, the support portion of the steering frame with respect to the main frame and the pivot portion of the upper arm and the rear end of the shock absorber with respect to the vehicle body frame are separately arranged. When the support portion and each pivotal support portion are reinforced in order to further strengthen the pivotal support of the upper arm and the shock absorber with respect to the above, the configuration may be complicated due to the large number of reinforced portions.

Further, during the traveling of the motorcycle, the impact force to be applied to the vehicle body frame side through the front wheels from the traveling road surface is mainly supported by the lower arm and the shock absorber, and at this time, the lower arm The load from each rear end of the shock absorber is supported by the vehicle body frame.

In the above case, since the load from the lower arm and the shock absorber to the body frame is based on the impact force and is large, the rear ends of the lower arm and the shock absorber are more firmly attached to the body frame. It is hoped that it will be supported.

(Object of the Invention) The present invention has been made in view of the above circumstances, and has a steering frame supported by a main frame and a steering frame supported by a body frame via a lower arm, an upper arm, and a shock absorber. When the knuckle is supported, the support of the steering frame by the main frame and the pivotal support of the lower arm, the upper arm, and the shock absorber with respect to the body frame are made stronger, and this is achieved with a simple configuration. The purpose is to.

(Structure of the Invention) A feature of the present invention for achieving the above object is that the vehicle body frame 2 comprises a pair of left and right main frames 3, 3 located outside an engine 17 supported by the vehicle body frame 2. A steering knuckle 25 projecting forward and upward from the main frame 3 and projecting from the main frame 3 to support the head pipe 8. A steering knuckle 25 is provided in front of the vehicle body frame 2 to support the front wheels 5, The rear ends of the lower arm 33 and the upper arm 42, which are arranged vertically apart, are pivotally supported by the vehicle body frame 2, while the steering knuckles 25 are pivotally supported at their respective front ends so as to be steerable. A shock absorber 40, which is long and has a rear end pivotally supported by the body frame 2 and a front end pivotally supported by the lower arm 33, is provided on a handle 9 supported by the head pipe 8. In the front wheel suspension of a motorcycle in which a steering knuckle 25 is interlocked and connected, (1) the main frame 3 extends from a front lower end portion of the main frame body 3a extending downward in a forwardly inclined direction. And a lower bracket 3c protruding downward from the front lower end of the main frame body 3a.
Then, the base of the steering frame 7 is supported and the rear ends of the upper arm 42 and the shock absorber 40 are pivotally supported. (2) The lower bracket 3c pivotally supports the rear end of the lower arm 33; The upper arm with respect to the upper bracket 3b
The pivot portion at the rear end of the shock absorber 40 is disposed closer to the main frame body 3a than the pivot portion at the rear end of 42. (4) The shock absorber 40 is arranged in a side view of the vehicle body. The point is that it is disposed so as to be substantially parallel to the main frame main body 3a.

(Operation) The operation of the above configuration is as follows.

(1) A main frame body 3a in which the main frame 3 extends in a downwardly inclined direction, an upper bracket 3b projecting upward from a front lower end of the main frame body 3a, and a main frame body 3a. A lower bracket 3c protruding downward from the front lower end, and the upper bracket 3b,
The base of the steering frame 7 is supported, and the rear ends of the upper arm 42 and the shock absorber 40 are pivotally supported.

Therefore, the support portion of the base of the steering frame 7 with respect to the body frame 2, the upper arm 42 and the shock absorber
Since the pivots at the rear end of each of the 40 are concentrated on the upper bracket 3b of the main frame 3, the strength of the support and the pivots can be improved by reinforcing the upper bracket 3b.

(2) The rear end of the lower arm 33 is pivotally supported by the lower bracket 3c, and the following operation is performed.

That is, when the motorcycle 1 travels, the impact force to be applied to the vehicle body frame 2 through the front wheels 5 from the traveling road surface side is mainly supported by the lower arm 33 and the shock absorber 40. The load applied to the body frame 2 from the rear ends of the lower arm 33 and the shock absorber 40 is large.

Therefore, as described in the above item (1), when the rear end of the shock absorber 40 is pivotally supported by the upper bracket 3b projecting upward from the main frame main body 3a, the rear end of the lower arm 33 is provided. Is pivotally supported by a lower bracket 3c projecting downward from the main frame main body 3a. Therefore, the lower arm 33 and the body frame 2 of the shock absorber 40 are pivotally supported.
Can be made sufficiently large in the vertical direction between the pivot portions.

Therefore, based on the impact force applied to the front ends of the lower arm 33 and the shock absorber 40 so as to face upward, the respective axial forces applied to the lower arm 33 and the shock absorber 40 can be further reduced. Can be.

In the above case, when the front wheel 5 is suddenly braked, a rearward load is applied to the upper bracket 3b and the lower bracket 3c of the main frame 3 from the lower arm 33 and the shock absorber 40. Since the upper bracket 3b and the lower bracket 3c protrude vertically from the main frame body 3a, when the load is applied to the main frame 3 from the lower arm 33 and the shock absorber 40, Applying a bending moment to the main frame body 3a of the main frame 3 is suppressed.

(3) The upper arm with respect to the upper bracket 3b
The pivot portion at the rear end of the shock absorber 40 is disposed closer to the main frame body 3a than the pivot portion at the rear end of 42,
The following effects occur.

That is, as described in the above item (2), the impact force to be applied to the vehicle body frame 2 through the front wheel 5 is mainly supported by the lower arm 33 and the shock absorber 40. The support by 42 would be less burdensome. Therefore, as described above, the pivot at the rear end of the shock absorber 40 with respect to the upper bracket 3b is disposed closer to the main frame body 3a, that is, the pivot at the rear end of the shock absorber 40 is The upper bracket 3b is provided on the base side having higher strength.

(4) The shock absorber 40 is disposed so as to be substantially parallel to the main frame main body 3a when viewed from the side of the vehicle body, and the following operation occurs.

That is, as described in the above item (2), the impact force to be applied to the vehicle body frame 2 through the front wheel 5 is mainly supported by the lower arm 33 and the shock absorber 40. Since the shock absorber 40 and the main frame 3 are pivotally supported with each other, the internal stress of the shock absorber 40 is generated in the axial direction of the shock absorber 40, and is applied to the main frame 3 from the shock absorber 40. The load to be applied is
It will be along 40 axial directions.

Therefore, as described above, the shock absorber 40 is disposed so as to be substantially parallel to the main frame main body 3a. Therefore, the main frame main body 3a applies a load from the shock absorber 40 in the longitudinal direction. The main frame 3, 3 is prevented from being given a bending moment.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

In FIG. 2, reference numeral 1 denotes a motorcycle, 2 denotes a body frame, and the body frame 2 is a pair of left and right main frames 3,
Has three. A front wheel 5 is supported on the left and right main frames 3 and 3 by a double wibone type front wheel suspension 4 so as to be steerable.

A steering frame 7 framed in a triangular shape in a side view projects forward and upward from the main frames 3, 3 side,
In this case, a front base 7a and a rear base 7b of the steering frame 7 are supported by the main frame 3, respectively. A head pipe 8 is supported at the projecting end of the steering frame 7, and the head pipe 8 supports a steering wheel 9 so as to be steerable. An interlocking means 10 is provided between the front wheel suspension 4 and the steering wheel 9. When the steering wheel 9 is steered, the front wheel 5 is steered through the front wheel suspension 4 and the interlocking means 10. It has become.

A rear arm 12 is provided at the rear of the main frames 3, 3 to support the pivot shaft 1.
The rear arm 12 is supported by a rear wheel 14 at the swinging end thereof so as to be swingable up and down by 3. Further, a shock absorber 15 is provided for damping an impact transmitted from the rear wheel 14 side to the vehicle body frame 2 side.

An engine 17 is supported on the vehicle body frame 2, and each of the main frames 3 is located outside the engine 17. The power of the engine 17 is transmitted to the rear wheel 14 so that the rear wheel 14 is driven. Reference numeral 19 denotes a fuel tank, reference numeral 20 denotes a seat, and a radiator 22 is provided near the front of the cylinder 21 of the engine 17.

The front wheel suspension 4 will be described in detail with reference to FIG. 1 and FIGS. 3 to 6.

A steering knuckle 25 is provided in front of the body frame 2.
The steering knuckle 25 is attached to the front wheel 5
Is located to the left of The steering knuckle 25 is made of sheet metal. A lower portion of the steering knuckle 25 is rotatably supported via a bearing 26. The axle 27 is screwed to a left side surface of the front wheel 5, so that the front wheel 5 is connected to the steering knuckle. Supported at the bottom of 25. A lower knuckle arm 30 is formed below the steering knuckle 25, and an upper knuckle arm 31 is formed above the same.

The left and right main frames 3, 3 are located outside of the engine 17 and extend forward and downward.
An upper bracket 3b protruding upward from the front lower end of the main frame main body 3a, and the main frame main body 3a
Lower bracket protruding downward from the front lower end of the
3c. A front base 7a of the steering frame 7 is supported by the upper bracket 3b, and a rear end of a sheet metal lower arm 33 extending in the front-rear direction is pivotally supported by the lower bracket 3c by a pivot shaft 34 so as to be vertically movable. ing.

The lower arm 33 includes a left arm 35 pivotally supported by the left main frame 3, a right arm 36 pivotally supported by the right main frame 3, and a connecting portion 37 for connecting the two arms 35, 36 to each other. It is composed of The lower knuckle arm 30 is pivotally supported at the front end of the left arm 35 by a lower joint 39 which is a ball joint.

A shock absorber 40 is provided between each of the arms 35, 36 and the main frames 3, 3. The shock absorber 40 extends long in the downwardly inclined direction, and has a rear end pivotally supported by the upper bracket 3b by a pivot shaft 40a, and a front end pivotally supported by the lower arm 33 by a pivot shaft 40b. And the above-mentioned shock absorber 40
Holds the lower arm 33 in a predetermined posture, and when an impact is transmitted from the front wheel 5 side to the vehicle body frame 2 side, the impact is absorbed and reduced by the expansion and contraction operation in the axial direction of the shock absorber 40.

A flat U-shaped upper arm 42 is disposed in front of the left and right main frames 3, 3 in plan view. The upper arm 42 is disposed above and separated from the upper arm 42. The rear end of the upper arm 42 is pivotally supported on the upper bracket 3b by left and right pivot shafts 43, 43 so as to be vertically swingable. The upper knuckle arm 31 is a ball joint Is pivotally supported by the upper joint 44.

In the above case, a pivot portion at the rear end of the shock absorber 40 is disposed closer to the main frame body 3a than a pivot portion at the rear end of the upper arm 42 with respect to the upper bracket 3b.

The shock absorber 40 is disposed so as to be substantially parallel to the main frame main body 3a in a side view of the vehicle body (FIG. 1).

A steering knuckle 25 is supported on the vehicle body frame 2 via a lower arm 33, an upper arm 42, and a shock absorber 40 so as to be able to swing up and down. It is designed to be steerable around.

In the above case, the lower arm 33 and the upper arm 42 are parallel to each other, and the lower arm 33 and the upper arm 42 constitute a parallel link. That is, when the steering knuckle 25 swings up and down, the lower arm 33 and the upper arm 42 move the steering knuckle 25 up and down substantially in parallel. Thus, the change in the caster angle α during the swing is suppressed to a small value.

The interlocking means 10 is of a telescopic type,
It is composed of a pair of front and rear shafts 46, 46 interlocked with the handle 9, and a case 47 in which these shafts 46, 46 are fitted slidably up and down and connected to the upper end of the steering knuckle 25. When the steering knuckle 25 swings up and down as described above, the shafts 46 and the case 47 slide up and down, whereby the interlocking means 10 expands and contracts to absorb the swing. And while this action takes place,
The steering operation of the steering wheel 9 is transmitted to the steering knuckle 25.

A brake disc 50 is mounted on the front wheel 5, and the brake disc 50 is located between the front wheel 5 and the steering knuckle 25. A caliper brake that frictionally joins the brake disc 50 to brake the front wheel 5 is provided on the rear side of the steering knuckle 25.
51 is screwed.

The upper arm 42 will be described in more detail with reference to FIG.

A virtual link 53 is set which is equal in length and parallel to the lower arm 33, and which forms a parallel link with the lower arm 33. In this case, the virtual link 53 is set such that when the steering knuckle 25 swings up and down, the steering knuckle 25 moves in parallel while maintaining the desired posture. When the steering knuckle 25 is rocked up and down respectively, the virtual link 53 is rocked by the rocking angle β around the pivot point 52.
Near the bisector 54 of the swing angle β, the upper arm 42
The pivot shaft 43, which is the pivot point of the robot, is located. Also,
A locus 56 of the upper joint 44 which is a front pivot point of the upper arm 42 at a substantially center point of the locus 55 of the front pivot point of the virtual link 53
Are crossing.

The virtual link 53 may be slightly inclined with respect to the lower arm 33. Further, the vicinity of the bisector 54 is a concept that includes immediately above the bisector 54. Furthermore, the two trajectories 55,5
6 may intersect at any of its upper and lower parts. Also,
This intersection is a concept including that both the trajectories 55 and 56 are in contact with each other.

(Effects of the Invention) According to the present invention, the body frame has a pair of left and right main frames located outside the engine supported by the body frame, and projects forward and upward from these main frames so that the protruding ends are the heads. A steering frame for supporting a pipe, a steering knuckle for supporting a front wheel positioned in front of the vehicle body frame, and pivoting the rear ends of a lower arm and an upper arm, which are vertically separated from each other, to the vehicle body frame. On the other hand, at each front end, the steering knuckle is pivotally supported so as to be steerable, and a shock absorber is provided which extends long in a downwardly inclined direction, and has a rear end pivotally supported by the body frame and a front end pivotally supported by the lower arm. For the front wheel suspension of a motorcycle, the steering knuckle is linked to the handle supported by the head pipe. (1) a main frame body in which the main frame extends in a downwardly inclined direction, an upper bracket projecting upward from a front lower end of the main frame body, and A lower bracket protruding downward from a lower end, wherein the upper bracket supports the base of the steering frame and pivotally supports the rear ends of the upper arm and the shock absorber.

For this reason, since the support portion at the base of the steering frame with respect to the body frame and the pivot portions at the rear ends of the upper arm and the shock absorber are concentrated on the upper bracket of the main frame, the support portion and each pivot portion are To improve the strength, it is sufficient to reinforce the upper bracket.

Therefore, the improvement of the strength of the support portion and the pivot portion can be achieved with a simple configuration because the number of reinforcing portions is small.

(2) The rear end of the lower arm is pivotally supported by the lower bracket, and the following effects are obtained.

That is, during traveling of the motorcycle, the impact force that is to be applied to the vehicle body frame side through the front wheels from the traveling road surface side is mainly supported by the lower arm and the shock absorber. The load applied to the vehicle body frame from each rear end is large.

Therefore, when the rear end of the shock absorber is pivotally supported by an upper bracket projecting upward from the main frame main body as in the above item (1), the rear end of the lower arm is connected to the main frame main body. The lower arm is pivotally supported by a lower bracket protruding downward from the lower arm, so that the vertical dimension between the lower arm and each pivotal support portion of the shock absorber with respect to the vehicle body frame can be made sufficiently large.

Therefore, based on the impact force applied to the front ends of the lower arm and the shock absorber so as to face upward, the respective axial forces applied to the lower arm and the shock absorber can be suppressed to be smaller. Therefore, the lower arm and the shock absorber are pivotally supported more firmly with respect to the vehicle body frame.

In the above case, when the front wheels are suddenly braked, a rearward load is applied to the upper bracket and the lower bracket of the main frame from the lower arm and the shock absorber. Since the bracket is projecting vertically from the main frame main body, when the load is applied to the main frame from the lower arm and the shock absorber, a bending moment is applied to the main frame main body of the main frame. Is suppressed.

Therefore, also at this point, the rear ends of the lower arm and the shock absorber are pivotally supported more firmly with respect to the vehicle body frame.

(3) The pivot portion at the rear end of the shock absorber is disposed closer to the main frame body than the pivot portion at the rear end of the upper arm with respect to the upper bracket, and the following effects are obtained.

That is, as described in the above item (2), the impact force to be applied to the vehicle body frame through the front wheels is mainly supported by the lower arm and the shock absorber, and therefore, the support by the load of the upper arm Requires less effort.

Therefore, as described above, the pivot portion at the rear end of the shock absorber with respect to the upper bracket is disposed closer to the main frame body, that is, the pivot portion at the rear end of the shock absorber is provided in the upper bracket. , Was arranged on the base side of greater strength, for this reason, the shock absorber,
It will be pivoted more firmly to the body frame.

(4) The shock absorber is disposed so as to be substantially parallel to the main frame main body in a side view of the vehicle body, and the following effects are produced.

That is, as described in the above item (2), the impact force to be applied to the vehicle body frame side through the front wheels is mainly supported by the lower arm and the shock absorber.
Since the shock absorber and the main frame are pivotally supported with each other, the internal stress of the shock absorber is generated in the axial direction of the shock absorber, and the load applied to the main frame from the shock absorber is reduced by the shock absorber. Along the axis of the vessel.

Therefore, as described above, the shock absorber is disposed so as to be substantially parallel to the main frame main body. For this reason, the main frame main body supports the load from the shock absorber in the longitudinal direction. And the bending moment is suppressed from being applied to the main frame.

Therefore, also in this respect, the shock absorber is firmly pivoted with respect to the vehicle body frame.

[Brief description of the drawings]

1 shows an embodiment of the present invention. FIG. 1 is a partially enlarged view of FIG. 2, FIG. 2 is an overall side view of a motorcycle, and FIG.
FIG. 4 is a partial cross-sectional view taken along the line III-III of FIG.
FIG. 5 is a sectional view taken along the line VV of FIG. 1, and FIG. 6 is a sectional view taken along the line VI-VI of FIG. 1 ... motorcycle, 2 ... body frame, 3 ... main frame, 3a ... main frame body, 3b ... upper bracket,
3c: Lower bracket, 4: Front wheel suspension, 5
... front wheel, 7 ... steering frame, 8 ... head pipe, 25 ... steering knuckle, 33 ... lower arm, 40 ... shock absorber, 42 ... upper arm, 43 ... pivot shaft (rear pivot point), 44 …… Upper joint (front pivot point),
52: pivot point, 53: virtual link, 54: bisector,
55: trajectory, 56: trajectory, α: caster angle, β: swing angle

──────────────────────────────────────────────────の Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) B62K 25/16 B62K 25/24

Claims (1)

(57) [Claims] A pair of left and right main frames located outside of an engine supported by the body frame, and a steering frame projecting forward and upward from the main frames and having a protruding end supporting a head pipe. A steering knuckle is provided in front of the vehicle body frame to support the front wheels, and the rear ends of the lower arm and the upper arm, which are vertically separated from each other, are pivotally supported by the vehicle body frame. The steering knuckle is pivotally supported so as to be steerable, and a shock absorber is provided which extends long in the downwardly inclined direction, has a rear end pivotally supported by the vehicle body frame, and a front end pivotally supported by the lower arm, and is supported by the head pipe. (2) a front wheel suspension of a motorcycle in which the steering knuckle is interlocked to a steering wheel to be operated; A main frame body extending in a forward-downwardly inclined direction, an upper bracket projecting upward from a front lower end of the main frame main body, and projecting downward from a front lower end of the main frame main body. A lower bracket to be provided, the upper bracket supporting the base of the steering frame and pivoting the rear ends of the upper arm and the shock absorber. (2) The rear end of the lower arm is fixed to the lower bracket. (3) disposing a pivot portion at the rear end of the shock absorber closer to the main frame body than a pivot portion at the rear end of the upper arm with respect to the upper bracket; A front wheel suspension of a motorcycle in which the shock absorber is disposed so as to be substantially parallel to the main frame body in a side view.