JPS633797B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a front fork for anti-nose diving of motorcycles, tricycles, etc.

Conventional front forks of this type require a large amount of oil, as the damping force is adjusted between the inner and outer cylinders by filling them with oil.

The present invention eliminates these conventional drawbacks, makes it possible to adjust the damping force with a small amount of oil, and also provides an anti-nose system that prevents the steering wheel from sinking when braking is applied while driving. Aims to provide a front fork of the dive.

Hereinafter, one embodiment of the present invention will be described based on the drawings.

In FIG. 1, reference numeral 1 denotes an inner cylinder of a front fork, which is slidably fitted into an outer cylinder 2. Inside this outer cylinder 2, an oil chamber extending in the axial direction is provided at the sliding portion with the inner cylinder 1, and a cylinder 4 is provided so as to divide this oil chamber into two into an inner oil chamber 3A and an outer oil chamber 3B. , is fixed to a guide member 5 fixed between the inner and outer cylinders. Note that 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. Between a pair of oil holes 9A and 9B provided in the outer cylinder 2 with this separation wall 8 in between,
A check valve 13 is provided which closes the orifice 12a communicating with both oil holes when it is extended and opens when it is compressed. In this check valve 13, the valve shaft 13a is connected to the operating rod 1.
6, and this valve stem 1
A circular spring plate 17 is fitted to the valve shaft 13a at a certain distance from the check valve 13, and a seat plate 18 is fitted to the valve shaft 13a so as to contact only the outer circumference of the spring plate 17.
A coil spring 19 is inserted between the seat plate 18 and the operating rod 16 so that the seat plate 18 is always in contact with the outer periphery of the spring plate 17. Further, the operating rod 16 is pushed by a flexible cable 14 connected to a brake lever via an operating lever 15 attached to the outer cylinder 2. That is, when braking is applied while driving, the operating rod 16 is pushed through the operating lever 15, and the pushing force causes the outer periphery of the spring plate 17 to curve via the coil spring 19, sequentially until the check valve 13 is pushed. The damping force works, and the orifice 12a is then completely closed to open the oil holes 9A and 9B.
This prevents the front fork from sinking. The orifice 12a can be adjusted by using a plurality of orifices 12b and 12c having different diameters.

Further, in addition to the above-mentioned damping mechanism, the front fork according to the present invention is equipped with a damping mechanism that operates with a relatively small damping force. That is,
As shown in FIG. 3, an oil hole 10 provided in the outer cylinder 2
A, 10B, a check valve 20 that opens the oil hole 10A when extended and closes the same oil hole 10A when compressed is held by a coil spring 21, and an orifice 22a
In the normal elongation process, oil flows through the oil holes 10A,
It is adapted to be expanded by a damping mechanism flowing through 10B. 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, oil holes 11A and 11B provided in the outer cylinder 2
A check valve 23 that opens the oil hole 11A during extension and 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, the oil hole 11A is closed. ,1
It is adapted to be expanded by a damping mechanism flowing through 1B. This damping mechanism also includes a plurality of orifices 2 with different diameters in addition to the orifice 25a as described above.
5b and 25c, the damping force can be adjusted.

Further, 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 inner circumference of the cylinder 4, and is usually located approximately in the center of the cylinder 4.
In the compression process, the oil moves to the oil hole 7B side, and the oil in the oil chamber 3A passes through the oil hole 7B, from the oil chamber 3B to the oil hole 9B, and from the orifice 12a to the oil hole 9A through the check valve 13.
, and a damping effect acts during that time. On the contrary, in the extension process, the sliding wall 2 moves to the oil hole 7A side, and the oil chamber 3
Normally, oil in A flows through oil hole 10A to check valve 2.
0, flows to the orifice 22a and the oil hole 10B, but if there is a sudden pressure change, the flow flows from the oil hole 11A through the check valve 23 to the orifice 25a and the oil hole 11.
Flow to B to make it grow faster.

As mentioned above, the present invention provides an axial oil chamber between the inner and outer cylinders on the outer cylinder side, and divides the oil chamber into two with a cylinder to provide a buffering effect, thereby reducing the amount of oil. It is possible to adjust the damping force, and the amount of movement of the sliding wall can also be increased, which has the effect of making the device more compact. Furthermore, in addition to these effects, the present invention links the braking mechanism and the damping mechanism to adjust the damping force based on the braking displacement, so that the steering wheel's position when braking while driving is adjusted. This has the effect of accurately preventing sinking, and since the mechanism is simple, it is also advantageous in terms of cost.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view showing one embodiment of the present invention, FIG. 2 is a cross-sectional view taken along line A-A in FIG. 1, FIG. 3 is a longitudinal cross-sectional view taken along line B-B in FIG. The figure is Figure 2 C-
It is a longitudinal cross-sectional view on the C line. 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, 22
a, 25a... Orifice, 13, 20, 23...
... Check valve, 14 ... Flexible cable, 15 ... Operation lever, 16 ... Operation rod, 17 ... Circular spring plate, 18
...Seat board, 26...Sliding wall.

Claims (1)

[Claims] 1. In a front fork in which the inner and outer cylinders are slidable, oil chambers 3A and 3B extending in the axial direction are provided inside the outer cylinder 2 of the sliding part, and the oil chamber is divided into two by a cylinder 4 into inner and outer sides. In addition, oil holes 7A and 7B are provided at both ends of the cylinder, and a separation chamber 8 is provided between the cylinder and the outer cylinder in the center thereof, and oil holes 9A and 9B are provided in the outer cylinder with the separation chamber in between. The communicating oil passage is provided with a damping mechanism having a check valve 13 that opens when compressed, and a flexible cable 14 connected to a brake lever is used to control the reverse operation via an operating lever 15 provided on the outer cylinder 2. The operating rod 16 into which the shaft 13a of the check valve 13 is slidably inserted is pressed, and the spring plate 17 and coil spring 19 provided on the outer periphery of the check valve 13 are pressed.
and the oil hole 9A provided in the outer cylinder 2 through the seat plate 18,
Orifice 12a or 12b, 1 communicating with 9B
Anti-nose dive front fork with a mechanism to adjust 2c.