JPS6216874B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a front fork for a motorcycle, a tricycle, etc.

Conventional front forks of this type have an inner cylinder,
Oil was also placed inside the outer cylinder to adjust the damping force between them, so a large amount of oil was required.

The present invention eliminates these conventional drawbacks and makes it possible to adjust the damping force with a small amount of oil. Therefore, in the front fork according to the present invention in which the inner and outer cylinders are slidable, the oil chamber extending in the axial direction provided in the sliding portion between the inner cylinder and the outer cylinder is controlled by the cylinder fixed inside the outer cylinder. Two oil chambers are formed which extend in the axial direction by dividing into an inner side and an outer side, and oil holes are provided at both ends of the cylinder, and a separation wall is provided between the cylinder and the outer cylinder at the center thereof, and A sliding wall in contact with the inner periphery of the cylinder is fixed to the outer periphery of the inner cylinder, and further includes a plurality of oil passages communicating oil chambers on both sides of the separation wall, and check valves provided in each of the oil passages that open during compression. The gist is that a damping mechanism is provided that has a check valve that opens when the cylinder is extended, and the desired damping force is obtained by moving oil through the damping mechanism through two oil chambers provided between the inner and outer cylinders. Therefore, the amount of oil used could be reduced to an extremely small amount. An embodiment of the present invention will be described in detail below with reference to the drawings.

Figure 1 shows an embodiment of the front fork of the present invention for two-wheeled vehicles, three-wheeled vehicles, etc., in particular a sectional view incorporating an anti-nose dive mechanism, and Figure 2 is a cross-sectional view of the front fork of the present invention.
A cross-sectional view, Figure 3 is the B-B cross-sectional view of Figure 2, and Figure 4 is
The figure is a sectional view taken along the line CC in FIG. In FIG. 1, reference numeral 1 denotes an inner cylinder of a front fork, which is slidably fitted into an outer cylinder 2. This outer cylinder 2
An oil chamber extending in the axial direction is provided inside the sliding portion with the inner cylinder 1, and a cylinder 4 is provided so as to divide this oil chamber into two, an inner oil chamber 3A and an outer oil chamber 3B. It is fixed to the guide member 5 which is fixed at. Note 6
is a sealing member. Oil holes 7A and 7B are provided at both ends of the cylinder 4, and a separation wall 8 including a sealing member is provided at the center of the cylinder 4 between it and the outer cylinder 2. A pair of oil holes 9 bored in the outer cylinder 2 in the damping mechanism that communicates the oil chambers on both sides of the separation wall 8.
There is an orifice 12 in the oil passage including A and 9B when it is extended.
A check valve 13 is provided which closes the valve a and opens during compression. However, it is equipped with an anti-nose dive device to prevent the steering wheel from sinking, especially when the brakes are applied while driving. That is, the flexible cable 14 (second
(see figure) rotates the operating lever 15 by braking and pushes the operating rod 16. A shaft 13a of the check valve 13 is slidably inserted into the operating rod 16.
Also, a circular spring plate 17 is attached to the shaft 13a of the check valve 13.
is fitted and installed with a certain gap between it and the check valve 13, and a seat plate 18 that contacts only the outer peripheral portion of the spring plate 17 is inserted on the outside thereof, and the seat plate 18 and The seat plate 18 is brought into contact with the outer periphery of the spring plate 17 by a coil spring 19 inserted between it and the operating rod 16. Therefore, by braking, the operating rod 1
When 6 is pressed, the spring plate 1 is released via the coil spring 19.
The outer periphery of the valve 7 is curved, and a damping force is applied sequentially until it pushes the check valve 13, and then it comes into contact with the valve seat and the orifice 1
By completely closing 2a, the oil passage is blocked and the front fork can be prevented from sinking, thereby preventing the steering wheel from sinking. The orifice 12a can be adjusted using a plurality of orifices 12b and 12c having different diameters.

Next, as shown in FIG. 3, another oil passage in the damping mechanism that communicates the oil chambers on both sides of the separation wall 8 and includes a pair of oil holes 10A and 10B has an oil hole 10 when the separation wall 8 is extended.
A check valve 20 which opens the oil hole A and closes the oil hole 10A during compression is held by a coil spring 21, and an orifice 22a allows oil to flow through the oil holes 10A and 10B during a normal expansion process. In addition to the orifice 22a, the damping force can be adjusted using a plurality of orifices 22b and 22c having different diameters. Furthermore, as shown in FIG. 4, an oil hole 11A is opened in another oil passage in the damping mechanism that communicates the oil chambers on both sides of the separation wall 8 and includes a pair of oil holes 11A and 11B when it is extended. On the other hand, a check valve 23 that closes the oil hole 11A during compression is held by a coil spring 24, and when there is a sudden pressure change due to the orifice 25a, oil flows through the oil holes 11A and 11B. This damping mechanism also has an orifice 25a as before.
In addition to the orifices 25b and 2 with different diameters,
5c allows the damping force to be adjusted. In addition, 26 in FIG. 1 is a sliding wall (cylinder) fixed to the outer circumferential side of the inner cylinder 1 and in contact with the circumference of the cylinder 4, and is usually located approximately in the center of the cylinder 4. In the compression process, the sliding wall 26 moves to the oil hole 7B side, and the oil in the oil chamber 3A passes through the oil hole 7B, flows from the oil chamber 3B to the oil hole 9B, and from the orifice 12a to the check valve 13 to the oil hole 9A. works. On the other hand, in the extension process, the sliding wall 26 moves toward the oil hole 7A, and the oil in the oil chamber 3A normally flows through the oil hole 1.
From 0A, through the check valve 20, the orifice 22a,
It flows to the oil hole 10B, but if there is a sudden pressure change, it flows from the oil hole 11A through the check valve 23 to the orifice 25a and the oil hole 11B to expand quickly.

In this way, in the present invention, between the inner and outer cylinders, an axial oil chamber is provided on the outer cylinder side, and the oil chamber is divided into two by the cylinder to perform a buffering effect, so damping can be achieved with a small amount of oil. The force can be adjusted, and the amount of movement of the sliding wall can also be increased, which has the effect of making the device more compact. Also, since the oil chamber is located on the outer cylinder side, the oil temperature does not rise.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing an embodiment of a front fork of a two-wheeled vehicle, tricycle, etc. of the present invention, Fig. 2 is a sectional view taken along line AA in Fig. 1, and Fig. 3 is a sectional view taken along line BB in Fig. FIG. 4 is a sectional view taken along line CC in FIG. 1...Inner cylinder, 2...Outer cylinder, 3A, 3B...Oil chamber, 4...
Cylinder, 5... Guide member, 7A, 7B... Oil hole, 8...
Separation wall, 9A, 9B, 10A, 10B, 11A,
11B... Oil hole, 12a, 22a, 25a... Orifice, 13, 20, 23... Check valve, 14... Flexible cable, 15... Operating lever, 16... Operating rod, 17... Circular spring plate, 18... Seat plate, 26...Sliding wall (cylinder).

Claims (1)

[Claims] 1. In a front fork in which the inner and outer cylinders are slidable, an oil chamber extending in the axial direction provided at the sliding portion between the inner cylinder 1 and the outer cylinder 2 is fixed to the inside of the outer cylinder 2. The cylinder 4 forms oil chambers 3A and 3B that are divided into two parts inside and outside and extend in the axial direction, and oil holes 7A and 7B are formed at both ends of the cylinder, and a hole between the cylinder and the outer cylinder is formed in the center thereof. A separation wall 8 is provided in the inner cylinder, and a sliding wall 26 in contact with the inner periphery of the cylinder is fixed to the outer periphery of the inner cylinder, and a plurality of oil passages communicating the oil chambers on both sides of the separation wall, and each of the oil passages are provided. A front fork characterized by being provided with a damping mechanism having a check valve 13 that opens when compressed and a check valve 20 that opens when extended. 2. In a front fork with slidable inner and outer cylinders, an oil chamber extending in the axial direction provided at the sliding portion of the inner cylinder 1 and outer cylinder 2 is connected to the inner side by a cylinder 4 fixed to the inside of the outer cylinder 2. Oil chambers 3A and 3B are formed outwardly in two and extend in the axial direction, and oil holes 7A and 7B are formed at both ends of the cylinder, and a separation wall 8 is provided between the cylinder and the outer cylinder in the center thereof. At the same time, a sliding wall 26 in contact with the inner periphery of the cylinder is fixed to the outer periphery of the inner cylinder, and a plurality of oil passages communicating the oil chambers on both sides of the separation wall, and a plurality of oil passages provided in each of the oil passages during compression are provided. A damping mechanism having a check valve 13 that opens and a check valve 20 that opens when extended is provided, and a spring plate 17 and a spring plate are provided on the shaft 13a of the check valve 13 with a gap from the check valve. A seat plate 18 that contacts only the outer periphery is inserted, and a coil spring 19 is interposed between the operating punch 16 and the seat plate 18 that are pushed by the braking operation, and the spring plate is pressed against the check valve 13. A front fork that is characterized by pressing down.