JPS62199583A - Front fork for motorcycle - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) This invention relates to a front fork for a motorcycle that supports steering wheels.

(Prior Art) Some motorcycles use an inverted front fork for supporting a steering wheel.

The inner tube supported on the steering wheel side of this inverted front fork is rotatably supported on the single body side via an under bracket and a handle crown.

The outer tube is connected to the underbracket and handlebar crown by threading the outer tube through the tightening portions of the underbracket and handlebar crown, and tightening the tightening portions with bolts.

(Problems to be Solved by the Invention) Since the inner tube inserted through the pair of outer tubes slides due to the vibration of the vehicle body, it is necessary to ensure parallelism between the pair of outer tubes. By the way, since the outer tube is supported by the under bracket and the handle crown and is relatively long, the distance between the tips of the outer tube tends to vary, and it is difficult to always maintain a constant distance.

In addition, the tightening parts of the under bracket and handle crown are formed thick to ensure rigidity, and the molecule flffl is bulky, and it is necessary to tighten and fix with a predetermined pressure, making assembly work difficult. It was a hassle.

This invention was made against the background of the above circumstances, and it is possible to more easily ensure the parallelism of a pair of outer tubes, increase the rigidity of the connecting part, reduce the need for a stop surface, and simplify assembly by 1 fL. The purpose is to share the front forks of two-wheeled vehicles.

(Means for Solving the Problems) In order to solve the above-mentioned problems, the present invention has an inner tube supported by a steering wheel, which is extendably inserted into a pair of actor tubes, and a pair of outer tubes. A front fork of a motorcycle in which a front fork is rotatably supported on a single unit side via an under bracket and a handle crown, characterized in that the pair of outer tubes, the under tube and the handle crown are integrally formed. .

(Function) In this invention, the pair of outer tubes, the lower bracket, and the handle crown are integrally formed, and the distance between the two outer tubes tends to be constant, ensuring parallelism, and the inner tube runs inside the outer tube. Move smoothly.

In addition, the rigidity of the connection between the outer tube, under bracket, and handle crown has been improved, and its molecular fIm
In addition, no assembly is required.
Assembling the front fork requires n desks.

(Example) Hereinafter, an example of the present invention will be described in detail based on the accompanying drawings.

In the figure, reference numeral 1 indicates a heavy body of a motorcycle, and this vehicle body 1 is composed of a head vibrator 2, a main frame 3, and a down tube 4. A front fork 5 is rotatably supported by the head vibe 2, and the front fork 5 has an inverted shape.

The inner tube 6 of the front fork 5 has several wheels 7 and 8 which are steering wheels attached thereto.

This inner tube 6 is pushed through the outer tube 9,
It is supported so that it can expand and contract with a built-in damper (not shown).

A cover 10 is disposed between the lower end of the inner tube 6 and the lower end of the outer tube 9 on the front side in the traveling direction. This cover 10 is made of synthetic resin, for example,
Its lower end is fixed to the lower end of the inner tube 6, and its upper end is fixed to the support 1 provided at the lower end of the outer tube 9.
1 and is movable in the axial direction.

A guide groove 10a is formed in the center of the cover 10 in the axial direction to smoothly guide water, mud, etc. that adheres to the inner tube 6 during rainy weather downward. It is prevented.

The pair of outer tubes 9 are integrally cast with the under bracket 12 and the handle crown 13, for example, from aluminum. Notches 12a and 13a are formed in the under bracket 12 and the handle crown 13.
Efforts are being made to make it lighter.

Both fjm12b of the under bracket 12 are formed integrally with the center portion of the outer tube 9, and both ends 13b of the handle crown 13 are formed integrally with the upper end portion of the handle crown 13. The distance between both outer tubes 9 is determined by the under bracket 12 and the handle crown 13.
It is easy to ensure parallelism.

A steering shaft 14 is located in the center of the under bracket 12.
is press-fitted, and this steering shaft 14 is connected to the head vibration 2.
is inserted into the A sleeve 15 is pushed through the upper part of the steering IPHL 14, and the handle crown 13 is applied to this sleeve 15 and fixed by a cap crown 16.

Next, the operation of this embodiment will be explained.

The pair of outer tubes 9 are integrally cast with the under bracket 12 and the handle crown 13, and the distance between the outer tubes 9 is determined by the integral molding with the under bracket 12 and the handle crown 13.

Therefore, the parallelism of the actuator tube 9 can be easily ensured with two members, the under bracket 12 and the handle crown 13, compared to the case where the actuator tube 9 is assembled.
The inner tube 6 inserted therein can slide smoothly.

Also, a pair of outer tubes 9 and an under bracket 1
2 and the handle crown 13 are integrally cast, the outer tube 9 and the under bracket 12
Since the outer tube 9 is connected at two points at the connection portion with the handle crown 13, the overall rigidity is improved.

Therefore, there is no need to provide a tightening part with a notched groove as in the conventional case, and the thickness of the connecting part can be made thinner accordingly.
It becomes possible to reduce the weight of the front fork 5.

Furthermore, an under bracket 12 and a handle crown 1
Since no special processing or tightening members are used for the tightening part of 3,
It is easy to process and can save costs.

(Effects of the Invention) As mentioned above, in this invention, since the pair of outer tubes, the under bracket and the handle crown are integrally formed, the distance between the pair of outer tubes is determined by the two members of the under bracket and the handle crown. -・Concurrency is easier to ensure.

Further, since the outer tube is integrally formed with two members, the under bracket and the handle crown, the rigidity of the connecting portion is improved, and the weight can be reduced accordingly. Furthermore, since no assembly is required between these members, the assembly work of the front fork to the vehicle body is simple and costs can be reduced.

[Brief explanation of drawings]

Figure 1 is a side view of a motorcycle to which this invention can be applied;
3 is a partial sectional view of the front fork, FIG. 4 is a top view of the handle crown, and FIG. 5 is a plan view of the under bracket. 1... Vehicle body 2... Head pipe 5... Front fork 6... Inner tube 9... Outer tube 10... Cover 12... Under bracket 13... Handle crown 14... Steering shaft diagram 1

Claims (1)

[Claims] A motorcycle in which an inner tube supported by a steering wheel is extendably inserted into a pair of outer tubes, and the pair of outer tubes are rotatably supported toward a single body via an under bracket and a handlebar crown. In the front fork, the pair of outer tubes;
A front fork for a motorcycle in which the undertube and the handlebar crown are integrally formed.