JPH0748470Y2 - Inverted front fork - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to an inverted front fork that suspends the front wheels of a motorcycle.

(Prior Art) A front fork for suspending a front wheel of a two-wheeled vehicle usually includes a pair of outer pipes and a pair of inner pipes slidably inserted into the outer pipes via springs. A hydraulic oil for damping the vibration when the inner pipe slides while slidingly contacting the inner peripheral surface of the outer pipe via a slide bush or the like is enclosed therein.

This type of front fork has an upright type with the inner pipe attached to the vehicle body side and the outer pipe attached to the front wheel axle, and an inverted type with the outer pipe attached to the vehicle body side and the inner pipe attached to the front wheel axle. However, in recent years, an inverted front fork has been widely used because it is more advantageous than the upright type in improving the rigidity of the front fork and reducing its weight.

In such an inverted front fork, usually, the upper end portion and the body portion of the pair of outer pipes are integrally coupled with each other at a vehicle width direction by a top bridge and a bottom bridge, which are vehicle body mounting members, respectively. The outer pipe is attached to the vehicle body side through. At this time, the front fork extends from both sides of the front wheel toward the axle of the front wheel, and the lower ends of the pair of inner pipes are connected to the axle. Here, the top bridge and the bottom bridge are usually tightened so as to sandwich the outer periphery of the outer pipe, and thereby fixed to the outer pipe.

However, due to the above-described tightening, in particular, the tightened portion of the outer pipe by the bottom bridge may be distorted inward, and the inner diameter of that portion may be slightly smaller than the other portions. At this time, when the outer diameter of the inner pipe inserted into the outer pipe and the inner diameter of the outer pipe are substantially the same, and the outer peripheral surface of the inner pipe is brought into sliding contact with the inner peripheral surface of the outer pipe, the inner peripheral surface of the outer pipe is The inner pipe is pressed and the sliding of the inner pipe is hindered. Therefore, conventionally, in consideration of the strain of the outer pipe in the tightened portion, the inner diameter of the outer pipe is made larger than the outer diameter of the inner pipe, and the inner pipe is slidably contacted with the inner peripheral surface of the tightened portion in the above tightened state. Was there.

However, in such a configuration, since a gap is generated between the inner pipe and the inner peripheral surface of the outer pipe in a portion other than the tightened portion of the outer pipe, rattling easily occurs between the inner pipe and the outer pipe, and sufficient rigidity of the outer pipe is obtained. In order to secure the above, it is necessary to increase the outer diameter along with the increase in the inner diameter, and if the outer diameter of the outer pipe increases in this way, the vehicle width also increases.

(PROBLEMS TO BE SOLVED) The present invention solves such inconvenience, and in an inverted front fork which is mounted on the vehicle body side of a motorcycle with the outer pipe being clamped by the vehicle body mounting member, the outer pipe is mounted by the vehicle body mounting member. It is an object of the present invention to provide an inverted front fork in which the inner pipe can slide in the outer pipe without hindrance while being fastened, and can prevent backlash between the inner pipe and the outer pipe. .

(Means for Solving the Problem) In order to achieve the above object, the present invention provides a method in which an inner pipe is slidably inserted from below in an outer pipe and the outer pipe is fastened with a body mounting member. In an inverted front fork that is attached to the vehicle body side of a two-wheeled vehicle and the end portion of the inner pipe protruding from the outer pipe is connected to the axle of the front wheel of the two-wheeled vehicle, the inner diameter of the tightened portion of the outer pipe tightened by the vehicle body mounting member is The outer diameter of the inner pipe is such that it is kept larger than the outer diameter of the inner pipe at least in the tightened state, and the inner diameter of the portion other than the tightened portion of the outer pipe is such that the outer peripheral surface of the inner pipe slides against the inner peripheral surface of the outer pipe. The feature is that the outer diameter of the inner pipe is approximately the same.

(Operation) According to the present invention, the inner diameter of the tightened portion is maintained larger than the outer diameter of the inner pipe even when the tightened portion of the outer pipe is tightened by the vehicle body mounting member.
The inner peripheral surface of the tightened portion does not make sliding contact with the inner pipe, and does not press the inner pipe sliding in the outer pipe. The inner diameter of the portion of the outer pipe other than the tightened portion is substantially the same as the outer diameter of the inner pipe, and the inner pipe slides while slidingly contacting the inner peripheral surface of the outer pipe other than the tightened portion.

(Example) An example of an inverted front fork of the present invention will be described with reference to FIGS. 1 and 2. FIG. 1 is a side view of a front portion of a motorcycle equipped with an inverted front fork, and FIG. 2 is an explanatory sectional view of the inverted front fork.

In FIGS. 1 and 2, 1 is an outer pipe of an inverted front fork A for suspending a front wheel 2 of a motorcycle on a body frame 3, and 4 is an inner pipe having an upper part inserted into the outer pipe 1 so as to be slidable. It is a pipe. As shown in FIG. 1, a top bridge 5a and a bottom bridge 5b, which are vehicle body mounting members, are externally inserted to the upper end portion and the body portion of the outer pipe 1, and the both bridges 5a and 5b are respectively attached to the bottom pipes 6a and 6b. Are clamped so that they are sandwiched, and thereby fixed to the outer pipe 1. The outer pipe 1 is attached to the head pipe 3a at the front end of the vehicle body frame 3 via these bridges 5a and 5b, and is rotatable around the axis of the head pipe 3a together with the handle 7.

Also, the tightening portion 1a of the outer pipe 1 by the bottom bridge 5b has a larger inner diameter than the other portions as shown in the second drawing, and accordingly, the outer diameter of the tightening portion 1a is also large. It is said that.

The outer diameter of the outer pipe 1 is gradually reduced downward from the tightened portion 1a.

As shown in FIG. 1, the inner pipe 4 is connected to the axle 2a of the front wheel 2 via an axon rudder 8 fitted to the lower end portion protruding downward from the outer pipe 1, and is shown in FIG. As described above, the upper end portion of the outer pipe 1 is connected to the upper end portion of the outer pipe 1 via the spring 9 and is urged downward. The inner pipe 4 has an outer diameter substantially the same as the inner diameter of the outer pipe 1 excluding the tightening portion 1a, and the outer peripheral surface of the inner pipe 4 is below the tightening portion 1a as shown in FIG. The slide pipes 10a, 10b provided in the outer pipe 1 are always in sliding contact with the inner peripheral surface of the lower portion of the outer pipe 1, and are slidable from a position below the tightening portion 1a to a position below the top bridge 5a. ing.

Further, hydraulic oil (not shown) is enclosed in the inner pipe 4 so that the vibration of the inner pipe 4 generated by the spring 9 when the inner pipe 4 slides is damped by the hydraulic braking mechanism 11 provided in the outer pipe 1. I have to. This hydraulic braking mechanism 11 damps its vibration by utilizing the flow resistance of the working oil when the inner pipe 4 slides, like a general front fork.

The inner pipe 4 of the front fork A having such a configuration is
The front wheel 2 slides as the front wheel 2 moves up and down according to road surface conditions and the like during traveling, and the sliding is damped by the hydraulic braking mechanism 11.
As a result, the shock caused by the vertical movement of the wheel 2 is absorbed.

In addition, as described above, the bottom bridge is attached to the tightening portion 1a.
If 5b is fixed and the tightening portion 1a is tightened, the second
As indicated by the phantom line in the figure, the tightening portion 1a is distorted and reduced in diameter, but its inner diameter is a dimension that does not abut the outer peripheral surface of the inner pipe 4 that slides inward in consideration of this distortion. The inner diameter of the inner pipe 4 is not hindered by this distortion.

The outer diameter of the inner pipe 4 is substantially the same as the inner diameter of the outer pipe 1 other than the tightening portion 1a as described above, and the outer peripheral surface of the inner pipe 4 is always slid on the inner peripheral surface of the outer pipe via the slide bushes 10a and 10b. Since they are in contact with each other, there is no play between the inner pipe 4 and the outer pipe 1.

(Effect) As is apparent from the above description, according to the inverted front fork of the present invention, even when the tightening portion of the outer pipe is tightened by the vehicle body mounting member, the inner diameter of the tightening portion is larger than the outer diameter of the inner pipe. Since it is maintained, the tightening portion does not press the inner pipe that slides inside thereof, and the inner pipe can slide smoothly without any trouble.

And, in the portion other than the tightened portion of the outer pipe, the inner diameter is made substantially the same as the outer diameter of the inner pipe, and the outer peripheral surface of the inner pipe makes sliding contact with the inner peripheral surface of the outer pipe.
Rattling between the outer pipe and the inner pipe is prevented,
The inner pipe can be slid smoothly.

[Brief description of drawings]

FIG. 1 is a side view of a front portion of a motorcycle including an example of the inverted front fork of the present invention, and FIG. 2 is an explanatory sectional view of the front fork. A ... Inverted front fork 1 ... Outer pipe, 1a ... Tightening part 2 ... Front wheel, 2a ... Axle 3 ... Body frame, 4 ... Inner pipe 5b ... Body mounting member

Claims (1)

[Scope of utility model registration request] 1. An inner pipe is slidably inserted into the outer pipe from below, and the outer pipe is attached to a vehicle body side of a two-wheeled vehicle with its body portion fastened by a vehicle body attachment member. In an inverted front fork whose end protruding from the inside is connected to the axle of the front wheel of a two-wheeled vehicle, the inner diameter of the tightened portion of the outer pipe tightened by the vehicle body mounting member is at least the outer diameter of the inner pipe in the tightened state. The inner diameter of the part other than the tightened part of the outer pipe is
An inverted front fork characterized in that the outer diameter of the inner pipe is approximately the same as the outer diameter of the inner pipe so that the outer peripheral surface of the inner pipe slides against the inner peripheral surface of the outer pipe.