JPH036554Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement of an anti-dive mechanism for a front fork that prevents the front part of the vehicle body from sinking when the vehicle is braked.

For example, when braking is applied to a running two-wheeled vehicle, the center of gravity of the vehicle moves forward due to inertia, causing the front of the vehicle to sink, and this phenomenon impairs steering stability.

Therefore, a so-called anti-dive mechanism for preventing this phenomenon has been provided in the front fork, and various anti-dive mechanisms have been proposed so far.

For example, a piston case is fixed to the side of the bottom case to form an oil passage in the case, an oil hole that opens to the oil passage is bored in the bottom case, and a piston that opens and closes the oil hole is connected to the piston. The piston is slidably supported in the case, and the outer end of the piston is connected to a brake member, and when braking, the piston connected to the brake member slides to close the oil hole. An anti-dive mechanism is known that blocks the flow of hydraulic oil sealed in a hydraulic fluid.

However, in such an anti-dive mechanism, since the piston and the braking member were directly connected by a metal pin, there was a problem in that a metallic sound was generated during operation.

In addition, since the piston and braking member were directly connected by a rod, there was no place to absorb dimensional errors due to manufacturing when assembling these parts, which required high processing accuracy and made assembly difficult. He was accompanying me.

The present invention was developed to effectively eliminate such problems, and its purpose is to eliminate metallic noise during operation, absorb dimensional errors in component parts, and improve assembly ease. The purpose is to provide an anti-dive mechanism for the front fork that makes it possible to

In order to achieve this purpose, the present invention includes a fork pipe that is slidably inserted and fitted into the bottom case.
A piston case is fixed to the side of the bottom case to form an oil passage in the case, an oil hole that opens to the oil passage is bored in the bottom case, and a piston that closes the oil hole during braking is installed in the bottom case. A front fork, which is slidably fitted and held in a piston case, exposes the outer end of the piston to the outside, and connects the outer end to a braking member via a pin inserted through the outer end. In the anti-dive mechanism, a circular connecting member is fitted into a circular hole bored in either the piston or the braking member via an elastic ring, an oblong hole is formed in the circular connecting member, and the oval hole is formed in the circular connecting member. The dimensions of the brake member are short in the direction of rotation about the rotation fulcrum of the braking member and long in the direction perpendicular to the rotation direction, and the pin is inserted into the oval hole and the pin is inserted into the hole. It is characterized in that the outer end of the piston is connected to a braking member.

A preferred embodiment of the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 is a partially cutaway side view of a front fork equipped with an anti-dive mechanism according to the present invention, and FIG. 2 is an enlarged detailed view of the outer end of the piston.

In the front fork 1 shown in FIG. 1, 2 is a bottom case with an open upper end, and a fork pipe 3 is inserted and fitted into the bottom case 2 from above so as to be vertically slidable. Further, a seat pipe 4 with an open upper end as shown in the figure is installed in the inner bottom of the bottom case 2 with a bolt 5, and the tip piston portion 4a of the seat pipe 4 is in sliding contact with the inner periphery of the fork pipe 3. There is. Further, an oil hole 4b is bored in the lower end of the seat pipe 4, and two oil lock pieces 6 and 7 are fitted on the outer periphery of the oil hole 4b so as to be vertically slidable. There is. The upward movement of the upper piece 6 is regulated by a stopper ring 8, and both pieces 6 and 7
A spring 9 is compressed in between as shown in the figure.

On the other hand, the upper end of the fork pipe 3 is closed with a fork bolt 10, and a free valve 11 that slides on the outer periphery of the seat pipe 4 and a free valve 11 on the inner periphery of the lower part of the fork pipe 3 and the inner periphery of the fork pipe 3 are closed with a fork bolt 10. An oil lock collar 12 that fits around the outer periphery of the lock piece 6 is fitted. A coil spring 13 is stretched between the fork bolt 10 in the fork pipe 3 and the upper end surface of the sheet pipe 4 as shown in the figure. In addition, 14 in FIG. 1 is a rebound spring.

In this way, the inside of the front fork 1 is divided into seat pipe inner/outer chambers S ₁ , S ₂ and upper chamber S ₃ , and hydraulic oil is sealed in these chambers S ₁ , S ₂ , S ₃ . The upper part of chamber S ₃ is occupied by gas.

By the way, as shown in the figure, a part of the lower outer periphery of the bottom case 2 protrudes outward a little to form a thick walled part 2a, and the thick walled part 2a has the inner and outer chambers S ₁ and S ₂ of the sheet pipe. An oil passage 15 that communicates with each other is integrally formed, and an oil passage 16 that communicates with the oil passage 15 is provided through the bottom case 2.

An adjuster 17 is rotatably fitted and held in the oil passage 16, and an adjustment dial 18 is fixed to the outer end of the adjuster 17. Also this adjuster 1
7 has a bottomed cylindrical portion 17a, and a plurality of orifices 17b of different diameters that selectively open into the oil passage 15 are provided on the peripheral wall of the cylindrical portion 17a.

On the other hand, an anti-dive mechanism 20 according to the present invention is provided at another location in the lower part of the bottom case 2.

In the above anti-dive mechanism, 21 is the bolt 2
2 is a piston case fastened to the side of the bottom case 2 at..., and an oil passage 23 is formed inside the piston case 21 and partitioned by the outer periphery of the bottom case 2. Seat pipe outer chamber S ₂ via oil hole 2b drilled in case 2
is connected to.

Also, a circular hole 21 is provided in the upper part of the piston case 21.
A is bored into the circular hole 21a, and a piston 24 is slidably inserted and fitted into the circular hole 21a as shown in the figure.
The piston 24 is always urged outward by a spring 25.

One end of the piston 24 facing into the oil passage 23 is bent outward to form a flange 24a, and a ring-shaped elastic packing 26 is interposed between the flange 24a and the piston case 21. It is set up. Further, a ring-shaped elastic packing 27 is fitted and held in a ring-shaped recess 2c provided around the oil hole 2b provided in the bottom case 2. In addition, 28 in FIG. 1 is a dust boot.

By the way, one end of a brake caliper 50 is rotatably attached to a bracket 2d projecting laterally of the bottom case 2 with a pin 51, and the other end of the caliper 50 is connected to the piston in the following manner. 2
It is pivotally connected to the outer end of 4.

That is, the outer end of the piston 24 is provided with a circular hole 24b, as shown in detail in FIG. are fitted and held through an elastic ring 30. The oval hole 29a is formed to be short in the direction of rotation of the brake caliper 50 about the pin 51 and to be long in the direction perpendicular thereto.

The outer end of the piston 24 of the brake caliper 50 is pivotally connected to the outer end of the piston 24 by a pin 52 inserted into the oblong hole 29a of the connecting member 29. The pin 52 is always in contact with the wall of the oblong hole 29a in the direction of rotation of the brake caliper 50.

The brake caliper 50 is driven by pressure supplied from a master cylinder (not shown) that generates pressure when the brake lever is operated, and presses against both sides of a brake disc 53 that rotates together with the front axle, thereby causing the brake caliper 50 to press against both sides of the brake disc 53, which rotates together with the front axle. Braking is applied by the frictional force acting on the crimping surface.

Next, the function of the front fork 1 will be explained.

First, when the fork pipe 3 moves downward relative to the bottom case 2 and the seat pipe 4 during the compression stroke, the volume of the seat pipe outer chamber S ₂ decreases, and part of the oil corresponding to this decrease is transferred to the seat pipe. The oil flows from the pipe outer chamber _S2 into the seat pipe inner chamber _S1 through the oil hole 2b, oil passages 23, 16, and oil hole 4b, and the remaining oil flows through the oil passage 15 and the orifice 17b provided in the adjuster 17. It flows into the seat pipe interior chamber _S1 through one of the orifices that opens to the oil passage 15, the oil passage 16, and the oil hole 4b.

During this compression stroke, a required damping force is generated within the front fork 1 based on the flow resistance when oil passes through each flow path.

Next, in the extension stroke, when the fork pipe 3 moves upward inside the bottom case, the seat pipe interior S ₁
The oil inside flows into the seat pipe outer chamber _S2 following a path opposite to that during the compression stroke, and in this case as well, a required damping force is generated within the front fork 1 as described above.

By the way, if the brake lever is operated to drive the master cylinder linked thereto, and the hydraulic pressure generated in the master cylinder is guided to the brake caliper 50 to press the caliper 50 against the brake disc 53, the caliper 50 The piston 24 rotates counterclockwise in FIG. 1 around the pin 51, and as a result, the piston 24 moves to the right in the same figure against the spring 25, and the flange 24a of the piston 24 comes into close contact with the elastic gasket 27, causing oil to flow out. Hole 2b is completely closed.

On the other hand, during braking, the center of gravity of the vehicle moves forward due to inertia, causing the front fork to move forward.
is about to be compressed, but since the oil hole 2b is blocked as described above, the oil in the seat pipe outer chamber _S2 is slightly compressed through the oil passage 15, the orifice 17b opening into the oil passage 15, the oil passage 16, and The oil flows into the seat pipe interior chamber _S1 through the oil hole 4b. At this time, orifice 1
The opening area of 7b is very small, and the flow resistance of oil flowing there is very high, so fork pipe 3
The downward movement of the vehicle, that is, the sinking of the front of the vehicle body, is effectively prevented, and the anti-dive function is demonstrated here.

In the anti-dive mechanism 20 described above, the piston 24 and the brake caliper 50 are connected through the pin 52 inserted into the oblong hole 29a of the connecting member 29, so the piston 24 and the brake caliper 50 are It is relatively movable in the vertical direction, and the relative movement of both members 24 and 50 effectively absorbs dimensional errors of each component, thereby improving the ease of assembling the parts.

Further, since the connecting member 29 is fitted and held in the circular hole 24b of the piston 24 via the elastic ring 30, no metallic noise is generated when the anti-dive mechanism 30 is operated.

Although the example above has been shown in which the connecting member 29 is held on the piston 24 side, the connecting members 29, 29 are fitted and held on the brake caliper 50 side as shown in FIG. 29a, 2
Brake caliper 5 with pin 52 inserted into 9a
Even if the piston 24 is connected to the piston 24, the same effect as described above can be obtained.

In addition, in the one shown in FIG. 2, the connecting member 29
Although measures to prevent rotation are not taken into consideration, if projections 129a projecting in all directions from the outer periphery of the connecting member 129 are engaged with the piston 124 as shown in FIG. 4, the rotation of the connecting member 129 can be prevented. .

As is clear from the above description, the present invention provides an anti-dive mechanism for a front fork in which the outer end of a piston that closes an oil hole provided in a bottom case when braking a vehicle is connected to a braking member by a pin. , a circular connecting member formed by having an oblong hole in the center of a circular hole bored in either the piston or the braking member is fitted and held via an elastic ring, and the oval shape of the connecting member is fitted and held through an elastic ring. Since the outer end of the piston is connected to the braking member with a pin inserted through the hole, no metallic noise is generated when the anti-dive mechanism is activated.
It is possible to absorb dimensional errors of component parts and improve assemblability. Further, the size of the oval hole formed in the circular connecting member is shortened in the rotation direction of the braking member,
In addition, since the pin is formed to be long in the direction orthogonal to the rotational direction, the pin inserted into the oval hole can be constantly brought into contact with the wall of the oval hole in the rotational direction of the braking member. Therefore, the rotation of the braking member is transmitted to the pin without any time difference, and there is no delay in anti-dive operation.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention; Fig. 1 is a partially cutaway side view of a front fork equipped with an anti-dive mechanism according to the present invention, Fig. 2 is an enlarged detailed view of the outer end of the piston, and Fig. 3 is a detailed view of the outer end of the piston. is an exploded perspective view showing another example of the connection between the piston and the brake caliper,
FIG. 4 is a diagram similar to FIG. 2 according to a modified embodiment. In the drawing, 1 is the front fork, 2 is the bottom case, 3 is the fork pipe, 4 is the seat pipe,
20 is an anti-dive mechanism, 21 is a piston case, 24 is a piston, 24b is a circular hole, 29 is a circular connecting member, 29a is an oblong hole, 30 is an elastic ring, 50 is a brake caliper, 51 and 52 are pins, 53 is the brake disc.

Claims (1)

[Scope of utility model registration request] A fork pipe is slidably inserted and fitted into the bottom case, a piston case is fixed to the side of the bottom case to form an oil passage in the case, and the bottom case has an oil hole that opens into the oil passage. A piston that closes the oil hole during braking is slidably fitted and held in the piston case, and an outer end of the piston is exposed to the outside and a pin is inserted through the outer end. In the anti-dive mechanism for a front fork, the outer end of which is connected to a brake member, a circular connecting member is fitted into a circular hole bored in either the piston or the brake member via an elastic ring, forming an oblong hole in the circular connecting member;
The size of the oval hole is formed to be short in the direction of rotation about the rotation fulcrum of the braking member and long in the direction perpendicular to the rotation direction, and the pin is inserted into the oval hole. An anti-dive mechanism for a front fork, characterized in that the outer end of the piston is connected to a braking member by the pin.