JPS604033B2 - Front fork of a motorcycle - Google Patents

Description

[Detailed Description of the Invention] If a motorcycle is braked suddenly while it is running, the rider's weight will be applied to the handlebars due to inertia, which will cause the handlebars to sink abnormally and affect maneuverability, which is extremely dangerous. be.

In order to eliminate this drawback, conventionally, a device has been used in which an oil passage opening/closing mechanism is provided on the side of the bottom case and is linked to the brake lever. However, it requires a complicated mechanism and has drawbacks such as difficulty in movement due to the large distance between it and the control lever. The present invention eliminates the above-mentioned drawbacks by providing a gas on-off valve at the upper end of the fork pipe, and also prevents the steering wheel from sinking during control, and also prevents the steering wheel from sinking even if it receives an impact from the road surface in that state. It provides a front fork that can be relaxed.

An embodiment of the present invention will be described in detail below with reference to the drawings. FIG. 1 is a longitudinal cross-sectional view showing one embodiment of a front fork of the present invention, in which the lower part of a fork pipe 1 to which a handle is attached and which suspends the front part of the vehicle body is slidably connected to a bottom case as is well known. A suspension spring 2 is stretched between them and oil 3 is filled.

The upper end of this fork pipe 1 is sealed with a fork port 4, and an auxiliary gas chamber 5 is provided inside the fork port 4.
It is connected to a main gas chamber 8 above the oil level in the fork pipe by means of passages 6 and 7. In addition, a hollow space is provided in the middle of the lotus passages 6 and 7 to iron the cylinder 9, and a valve core 10 in the cylinder 9 (according to JIS, D4211).
, the slider 11, the first spring 12, and the spring receiver 13 are iron-clad in this order, and normally the tip end surface of the slider 11 is aligned with the shaft 1 of the valve core 10.
Push the shaft head 10a of 0c to open the communication passages 6 and 7. In addition, as shown in FIGS. 2A and 2B, when the valve core 10 pushes the bell head 10a, the spring 10b contracts and the "shaft 10
The valve part provided at the tip of the valve core 10 presses the valve packing 10d and protrudes from the end face of the rope 10e to form a passage, so that the inside and outside of the valve core 10 are flush with each other. It is common. Further, the rear end side of the slider 11 on the opposite side from the valve core 10 has a small diameter portion 11a, and this small diameter portion 11a has a spring receiver 13.
The spring receiver 13 is extended to the outside of the cylindrical body 9 through the cylindrical body 9, and the spring receiver 13 is screwed onto the cylindrical body 9. Note that the first spring 12 is inserted into this small diameter portion 11a, is located between the spring receiver 13 and the large weight portion 11b of the slider 11, pushes the slider 11 toward the valve core 10, and presses the shaft head of the valve core 10. I'm pressing 10a. Therefore, one part of the valve core is opened, and the main gas chamber 8 and the auxiliary gas chamber 5 are completely closed within the valve core. The spring receiver 13 is screwed together with the cylindrical body 9, and when the knob 13a of the spring receiver 13 is turned as shown in FIG.
(as seen from the figure) direction, and the tension of the first spring '12 (the initial load of the spring) is changed. In this case, a large number of vertical grooves 13b in the axial direction are provided on the entire outer circumference of the tip end side of the spring receiver 13,
A small spring presses the steel ball 14 in an elastic manner to create a sense of moderation. The end of the small-diameter portion 11a of the slider 11 is connected via a second spring 16 to a wire 15 that interlocks with the brake lever. Note that the second spring 16 is
The spring is stronger than spring 12, and when the brake is applied,
First, the first spring 12 is compressed, and then the second spring 16 is expanded, so that the operating range of the brake lever can be absorbed. Further, in the figure, 17 is a circle, and 18 is a gas sealing port. In the above configuration, the shaft head 10a of the valve core 10 is normally pushed by the distal end surface of the slider 11 and the lotus passage 6,
7 is carried through the valve core 10, and therefore the vehicle body is suspended by the suspension spring 2 and an air spring made of the gas sealed in the main gas chamber 8 and the auxiliary gas chamber 5, and the fork pipe expands and contracts according to its overall spring characteristics. Do exercise.

However, when braking is applied, the wire 15 is pulled and the slider 11 is pulled, so the shaft head 10a of the valve core 10 and the tip end surface of the slider 11 are separated, and the valve packing 1 in FIG.
0d closes the body 10e and the valve core 10 is closed, so the auxiliary gas chamber 5 is separated and only the main gas chamber 8 acts as an air spring. Therefore, when the fork pipe 1 descends, the air pressure above the oil surface rises rapidly, preventing it from descending.
Therefore, the steering wheel is prevented from sinking due to the inertia of the passenger, and stable maneuverability can be maintained. In addition, if the front wheel rides on a bump on the road surface in this state, the air pressure in the main gas chamber 8 will rise significantly, and the air will enter the inside of the valve core 10 from the lotus passage 7 and close the valve gasket 10d.
, the valve core 10 opens, and when the fork falls into the recess and extends, the pressure in the main gas chamber 8 drops rapidly, absorbing the slider 11, and thus pushing the shaft head 10a of the valve core 10, opening the main gas chamber. 8 and the auxiliary gas chamber 5 are connected. Therefore, the front fork can be easily compressed or expanded to reduce the impact from approximately the surface. Further, even when the above-mentioned handle load due to inertia disappears while the brake is applied, the fork pipe quickly returns to the specified position. As explained in detail above, according to the present invention, by simply providing a normal valve core and an auxiliary gas chamber at the upper end of the front fork, it is possible to prevent the steering wheel from sinking during control and maintain stable maneuverability. At the same time, the cushioning effect against impacts from the road surface is maintained. In addition, the valve core can be placed at the upper end of the front fork, and its appearance is not much different from a conventional front fork, but it is also extremely short, and can be easily connected to the control lever of the handle using a thread. There are other effects.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal cross-sectional view showing an embodiment of the front fork of a two-wheeled vehicle according to the present invention, Fig. 2 shows a valve core, Fig. A is a side view, B is a partially longitudinal cross-sectional front view thereof, and Fig. 3 is a front view of a spring receiver. It is a diagram. 1... fork pipe, 2... suspension spring, 3...
Oil, 4... Fork bolt, 5... Auxiliary gas chamber, 6
, 7... Lotus passage, 8... Main gas chamber, 9... Cylindrical body,
DESCRIPTION OF SYMBOLS 10...Valve core, 10a...Mari head, 10d...Valve packing, 11...Numamoko, 12...First spring,
13... Spring receiver, 14... Steel ball, 15... Wire 1, 16... Second spring. Figure 1 Figure 2

Claims (1)

[Claims] 1. An auxiliary gas chamber is provided inside the fork bolt at the upper end of the fork pipe that is slidably fitted into the bottom case connected to the front wheel shaft to suspend the front part of the vehicle body, and the oil level in the fork pipe is In addition to connecting the communication passage to the main gas chamber above,
A cylindrical body is fitted into a hollow space provided in the middle of the communication path, and a valve core, a slider, a first spring, and a spring receiver are fitted in this order in the cylindrical body, and the distal end surface of the slider is normally fitted. The shaft head of the valve core is pushed by the first spring pressure to open the communication passage, and the small diameter part on the rear end side of the other slider passes through the shaft core part of the spring receiver to the outside of the cylinder body. The spring receiver has a large number of longitudinal grooves in the axial direction on the entire outer periphery of the tip side and is screwed onto the cylinder, and a steel ball provided on the wall on the cylinder side is inserted into the vertical groove in an elastic shape. A two-wheeled vehicle characterized in that the tension of the first spring can be adjusted by pressing it and rotating the rear end side, and the small diameter end of the slider is connected to an external wire that interlocks with a brake lever. front fork.