JPH0434263Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to an inverted hydraulic shock absorber, and particularly to a fixing structure between a cylinder and an inner tube.

(Prior art) An inverted front walk as an inverted hydraulic shock absorber used for motorcycles is disclosed in USP4561669, for example.
As described in the specification, the inner tube is slidably inserted into the outer tube from below, the upper end of the outer tube is closed with a fork bolt, and the lower end of the inner tube is closed with a lower bracket. A cylinder is installed in the inner tube of this lower bracket, and a piston rod whose upper end is attached to the fork bolt of the outer tube is inserted into this cylinder. It is equipped with a piston that slides into contact with the surface.

A convex oil lock piece that protrudes downward is formed in the center of the fork bolt of the outer tube, and a guide bush that slides on the outer circumference of the piston rod is fixed to the inner periphery of the upper end of the cylinder. The upper end of the cylinder is a concave oil lock collar that fits over the oil lock piece when the shock absorber is fully compressed, and hydraulic oil is sealed in a chamber surrounded by the oil lock piece, oil lock collar, and guide bushing when the shock absorber is fully compressed. Therefore, oil lock is activated to prevent bottoming out.

(Problems to be solved by the invention) This is a so-called cartridge type cylinder in which a cylinder in which hydraulic oil is sealed in a shock absorber and a piston rod having a fixed piston that slides on the inner circumferential surface of the cylinder are arranged. In an inverted front fork, an oil lock mechanism is provided above the shock absorber, and in order for this oil lock mechanism to operate reliably, the inside of the oil lock collar at the upper end of the cylinder must be filled with hydraulic oil at all times.

However, since the upper portion of the shock absorber generally serves as a gas chamber, there may be a shortage of hydraulic oil in the oil lock collar, and the oil lock may not function satisfactorily. Therefore, it is conceivable to arrange the oil lock mechanism in the lower part of the shock absorber, but in the case of an inverted shock absorber, the structure becomes complicated due to the relationship with the cylinder and the like.

(Means for solving the problem) In order to solve the above problem, the present invention fixes an oil lock collar to the tip of the piston rod,
Attach the oil lock piece into which the oil lock collar fits to the inner peripheral surface of the lower end of the cylinder, and then fix the bottom piece to the lower end of the inner tube, and connect the oil lock piece and the bottom piece with one lock bolt. and fitted it into the recess of the bracket.

(Function) Since the oil lock chamber is provided at the bottom of the shock absorber, oil lock can be applied reliably, and the cylinder and oil lock piece are integrally fixed to the inner tube by one lock bolt, so that the cylinder can be fixed to the inner tube. The number of parts required for fixing is reduced.

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

Fig. 1 is a sectional view showing the hydraulic shock absorber according to the present invention in its most compressed state, Fig. 2 is a sectional view taken along the - line in Fig. 1, and Fig. 3 is an enlarged sectional view of the main part of Fig. 1. .

This hydraulic shock absorber is closed by fitting a top cap 2 to the upper end of an outer tube 1, and an inner tube 3 is slidably inserted from below the outer tube 1 to the inner periphery of the lower end of the inner tube 3. A bottom piece 4 is fixed by caulking, and a cylinder 5 facing into the inner tube 3 is installed on the upper surface of the bottom piece 4.

A damping force generating mechanism 6 is attached to the inner periphery of the upper end of the cylinder 5, and a spring receiver 7 is attached to the upper end surface of the cylinder 5, and between this spring receiver 7 and a spring receiver 8 provided at the bottom of the top cap 2. A spring 9 is interposed to press the cylinder 5 downward.

Further, inside the cylinder 5, a piston rod 11 whose upper end is screwed onto the top cap 2 of the outer tube 1 faces from above, and at the tip of the piston rod 11 is installed a piston 12 that slides into contact with the inner circumferential surface of the cylinder 5. This piston 12 is provided with an extension side oil passage 13 and a compression side oil passage 14, and an extension side bubble 15 for opening and closing the extension side oil passage 13.

Further, an oil lock piston 17 as an oil lock collar is fixed to the tip of the piston rod 11 below the piston 12, and an oil passage 18 is formed in the oil lock piston 17. A check valve 19 is provided which opens at .

An oil lock piece 22 having a recess 21 into which the oil lock piston 17 fits is fitted into the lower end of the cylinder 5, and the cylinder 5 and the oil lock piece 22 are fixed by a locking ring 23. The oil lock piece 22 is fixed to the bottom piece 4 with a lock bolt 24 formed on the bottom piece 4 and inserted into the through hole 4a from below.

Furthermore, the lower end of the inner tube 3 is fitted into the recess 27 of the C-shaped cross-sectional mounting bracket 26 as shown in FIG. 2, and the inner tube 3 is fixed by tightening the bolt 28 screwed into the mounting bracket 26. are doing. At this time, the lower end surface of the inner tube 3 and the recess 2 of the mounting bracket 26
A space portion 28 is formed between the bottom surface of the portion 7 and the bottom surface of the portion 7 .

Furthermore, an axle mounting hole 29 is formed in the lower part of the mounting bracket 26, and the axle mounting hole 29 is further formed in the mounting bracket 26.
A slit 30 is formed facing the
A bolt hole 31 facing the space 28 is formed through the bolt hole 31, and by screwing and tightening a bolt 32 into the bolt hole 31, the axle is attached to the mounting bracket 26.
It is fixed to .

With the above structure, when installing, after placing the cylinder 5 equipped with the oil lock piece 22 on the bottom piece 4 of the inner tube 3, the through hole 4a is inserted from below the bottom piece 4.
The cylinder 5 and the oil lock piece 22 are fixed to the inner tube 3 by inserting the lock bolt 24 through the inner tube 3 and screwing it onto the oil lock piece 22 and engaging the oil lock piece 22 with the bottom piece 4.

Furthermore, when the piston rod 11 moves downward during the compression stroke of this hydraulic shock absorber and reaches the maximum compression state, the outer peripheral surface of the oil lock piston 17 fits into the inner peripheral surface of the recess 21 of the oil lock piece 22.
The hydraulic oil is trapped in the oil lock chamber formed between the lower end surface of the oil lock piston 17 and the recess 21 of the oil lock piece 22, resulting in an oil lock state.

When the piston rod 11 moves upward from this state to the extension stroke, the oil lock piston 17
The check valve 19 opens and the oil passage 18 is opened, so hydraulic oil flows between the lower end surface of the oil lock piston 17 and the recess 21 of the oil lock piece 22, and the piston rod 11 moves upward smoothly. I can do it.

(Effects of the invention) As explained above, according to the invention, since the oil lock chamber is provided at the bottom of the shock absorber, the oil lock can be reliably applied, and the oil lock piece and the bottom piece are connected by the lock bolt. The cylinder and oil lock piece are integrally fixed to the inner tube by simply
The number of parts for fixing the cylinder to the inner tube is reduced, and the assembly work becomes easier.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing the hydraulic shock absorber according to the present invention in its most compressed state, Fig. 2 is a sectional view taken along the - line in Fig. 1, and Fig. 3 is an enlarged sectional view of the main part of Fig. 1. . In the drawings, 1 is an outer tube, 3 is an inner tube, 4 is a bottom piece, 11 is a piston rod, 12 is a piston, 17 is an oil lock piston, 22 is an oil lock piece, and 24 is a lock bolt.

Claims (1)

[Scope of utility model registration request] An inner tube is slidably inserted into the outer tube from below, a cylinder is installed in the inner bottom of the inner tube, a piston is placed inside the cylinder from above, and the tip of the piston rod is slid into the cinder. In an inverted hydraulic shock absorber equipped with a piston in contact with the piston, an oil lock piece is installed on the inner peripheral surface of the lower end of the cylinder, the oil lock piece having a recess into which an oil lock collar attached to the lower end of the piston rod fits, and the lower end of the inner tube. The bottom piece is fixed to the inner circumference of the part,
The oil lock piece and the bottom piece are connected with a lock bolt, the cylinder is fixed to the inner tube, and the lower end of the inner tube is fitted and fixed in the recess of the axle mounting bracket. Cylinder mounting structure of hydraulic shock absorber.