JPH0227231Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a mechanism for adjusting the preload of a suspension spring of a shock absorber used as a front fork of a motorcycle, etc.

(Prior Art) Some shock absorbers conventionally used as front forks of motorcycles are equipped with a mechanism for adjusting the stiffness of a suspension spring depending on the load and road surface conditions.

A common adjustment mechanism for this is to form a cam surface on the lower end of the fork bolt, and a pin fixed to an adjustment pipe with a spring seat attached to this cam surface is engaged to adjust the preload of the spring. When adjusting, push down the adjustment pipe against the elastic force of the spring to release the locking state between the pin and the cam surface, and turn the adjustment pipe to lock the pin to the other cam surface. It is something.

However, according to the above-mentioned mechanism, a large amount of force is required to push down the adjustment pipe, and continuous fine adjustment is not possible.
An improved variable preload mechanism was proposed as No. 57-124378.

This preload variable mechanism is as shown in Figure 6.
An annular housing 10 is attached to the upper end of the tube 100.
1, insert the adjustment member 102 into the center hole of this housing 101, screw the female threaded part of the nut member 103 into the male threaded part carved on the lower outer periphery of this adjustment member 102, and then tighten the nut member 103. A spring seat 105 supporting the upper end of the suspension spring 104 is attached to the lower end of the suspension spring 103, and the nut member 1
03 is engaged with a long groove 107 formed in the axial direction of the housing 101. To adjust the preload of the spring 104, a pin 106 fixed to the adjusting member 102 is inserted into a slit 108 formed at the upper end of the adjusting member 102. Insert the tip of the screwdriver and rotate the adjusting member 102 with the ball 109 pushed outward, and this rotation causes the nut member 103 to be screwed in the axial direction without being rotated due to the engagement between the pin 106 and the long groove 107. The preload of the spring 104 is adjusted by adjusting the preload of the spring 104.

(Problems to be Solved by the Invention) According to the variable preload mechanism described above, the preload of the sling can be finely adjusted continuously, but it has the disadvantage that adjustment cannot be made without always using a jig such as a screwdriver.

(Means for solving the problem) In order to solve the above problem, the present invention has an outer fork bolt screwed onto the upper end of the buffer pipe, and a spring attached to the inner fork bolt rotatably inserted into the outer fork bolt. The adjustment guide with the seat attached is screwed together, the adjustment guide and the outer fork bolt are prevented from rotating through a pin, and the adjustment guide is forced upward into the upwardly opening recess formed in the outer fork bolt. A locking member is stored, a part of the locking member is engaged with the inner fork bolt, and the engagement can be released by external operation using a pressing member provided between the inner fork bolt and the outer fork bolt. I did it like that.

(Example) An example of the present invention will be described below based on the accompanying drawings.

FIG. 1 is a longitudinal cross-sectional view of a main part of a shock absorber to which a variable mechanism according to the present invention is applied, and an outer fork bolt 2 is screwed onto the upper end of a fork pipe 1 from above. As shown in FIG. 2, which is a cross-sectional view, and FIG. 3, which is a plan view, this outer fork bolt 2 has an angular upper part and a through hole in the center consisting of a large diameter hole 3a and a small diameter hole 3b. 3 is formed, and two recesses 4, 4 are formed that open at the step between the large-diameter hole 3a and the small-diameter hole 3b, and a leg 5 hangs downward from one side. A long groove 6 is formed along the axial direction.

Further, an inner fork bolt 7 is rotatably inserted into the through hole 3 of the outer fork bolt 2 from above, and the inner fork bolt 7 is shown in FIG. 4, which is a half-cut sectional view, and FIG. 5, which is a bottom view of the main part. As shown in , it has a multi-stage cylindrical shape whose diameter gradually decreases from the top to the bottom, and the external shape of the portion 7a facing the large diameter hole 3a of the outer fork bolt 2 is smaller in diameter than the large diameter hole 3a, The outer shape of the portion 7b facing the small diameter hole 3b is approximately the same as that of the small diameter hole 3b. A recess 9 is formed in a portion facing the recess 4 .

Thus, the inner fork bolt 7 is inserted into the outer fork bolt 2 with the locking member 11 such as a pin urged upward by the spring 10 stored in the recess 4 of the outer fork bolt 2. A part of the upper end of the locking member 11 engages with the recess 9 of the inner fork bolt 7 due to the elastic force of the spring 10, and the inner fork bolt 7
The rotation of is regulated.

Furthermore, the large diameter hole 3a of the outer fork bolt 2
A gap will be formed between the inner fork bolt 7 and the portion 7a of the inner fork bolt 7 facing the large diameter hole 3a, and a collar-shaped pressing member 12 and a dust sealing O-ring 8 are inserted into this gap. It is slidably interposed through the hole. The pressing member 12 is prevented from coming off upward by the inner side of the upper end coming into contact with the stepped portion of the inner fork bolt 7, and has a leg piece 13 on the member facing the locking member 11. By pressing downward, the locking member 11 is pushed down by the leg piece 13, and the engagement state between the locking member 11 and the recess 9 is released.

On the other hand, a male threaded portion is carved on the outer periphery of the lower half of the inner fork bolt 7, an adjustment guide 14 is screwed into this male threaded portion, and a spring seat 15 is attached to the lower end of this adjustment guide 14. This spring seat 15 supports the upper end of the suspension spring 16. Further, a pin 1 protruding outward is provided at the upper end of the adjustment guide 14.
7 is implanted, and this pin 17 is engaged with a long groove 6 formed in the leg portion 5 of the outer fork bolt 2.

To adjust the preload of the spring 16 using the variable preload mechanism configured as described above, press down the pressing member 12 by hand, and press down on the locking member 11.
completely into the recess 4. Then, the engagement between the outer fork bolt 2 and the inner fork bolt 7 is released, so the inner fork bolt 7 is rotated using the hand pushing the pressing member 12 or another hand.

Then, the adjustment guide 14 also tries to rotate together with the inner fork bolt 17, but since the adjustment guide 14 is engaged with the outer fork bolt 2 via the pin 17, it does not rotate.
Instead, it spirals in the axial direction, and together with this, the spring seat 15 also moves in the vertical direction, and the preload of the spring 16 changes.

(Effect of the invention) As explained above, according to the invention, it is possible to manually release the locking state of the locking member that has the function of preventing the inner fork bolt from rotating relative to the outer fork bolt without using a jig such as a screwdriver. Since this can be done with a hand, there is no need to always have a jig such as a screwdriver on hand. Further, according to the present invention, the preload adjustment work can be performed with one hand, making the operation extremely easy.

[Brief explanation of the drawing]

Fig. 1 is a half-cut sectional view of the upper part of a shock absorber to which the variable preload mechanism according to the present invention is applied, Fig. 2 is a longitudinal sectional view of the outer fork bolt, Fig. 3 is a plan view of the outer fork bolt, and Fig. 4 is a FIG. 5 is a bottom view of essential parts of the inner fork bolt, and FIG. 6 is a sectional view of a conventional variable preload mechanism. In the drawings, 1 is a fork pipe, 2 is an outer fork bolt, 4 and 9 are recesses, 6 is a long groove, 7 is an inner fork bolt, 11 is a locking member, and 12
14 is a pressing member, 14 is an adjustment guide, 15 is a spring seat, and 16 is a suspension spring.

Claims (1)

[Scope of utility model registration request] Fit an outer fork bolt to the upper end of the pipe, insert an inner fork bolt into the outer fork bolt so that it can rotate freely, screw an adjustment guide with a spring seat attached to the inner fork bolt, and insert the azimuth guide into the adjustment guide. In the front fork, the outer fork bolt has a recess that opens upward, and a locking member that is biased upward is provided in the recess. Further, the inner fork bolt is formed with a recessed portion in which a part of the locking member engages, and the locking member is pushed down and engaged between the inner circumference of the outer fork bolt and the outer circumference of the inner fork bolt. 1. A variable spring preload mechanism for a shock absorber, characterized in that a pressing member for releasing the locked state is provided.