JPH0557474U - shock absorber - Google Patents

Abstract

(57) [Abstract] [Purpose] A piston or a damping force generating member can be attached to the piston rod without cutting the piston rod, the strength of the piston rod is maintained, and the damping force is not adversely affected. [Structure] In a shock absorber in which a piston 5 and a damping force generating member are assembled to a piston rod 12, and the piston rod is movably inserted into a cylinder 14 via the piston, a pipe-shaped stopper is provided on the outer circumference of the piston rod having a uniform thickness. 18 is inserted and fixed, and the piston inserted into the outer periphery of the lower portion of the piston rod and the damping force generating member are held by the stopper and the piston nut 9 screwed to the lower end of the piston rod.

Description

[Detailed description of the device]

[0001]

[Industrial application]

 The present invention relates to a shock absorber that is interposed between a vehicle body and an axle of a vehicle to damp vibrations from the road surface.

[0002]

[Prior Art]

 In this type of shock absorber, for example, as shown in FIG. 5, a piston rod 12 is movably inserted into a cylinder 14 via a piston 5, and an orifice 15 formed in a rotary valve 1 when the piston rod 12 is extended. The expansion side damping force is generated by the leaf valve 7 and the main valve 8, and the compression side damping force is generated by the compression side leaf valve 4 and the orifice 15 of the rotary valve 1 during the compression operation.

The piston rod 12 is formed by lathing the lower portion of the main body 12a by lathing to form a small diameter portion 12b, and a locking step portion 12c is formed between the main body 12a and the small diameter portion 12b.

A valve seat 2, a non-return spring 3, a pressure side leaf valve 4, a piston 5, an extension side leaf valve 7, a main valve 8, and a spring 6 are arranged in this order from the bottom of the small diameter portion 12 b of the piston rod 12. Are inserted in series, and these assemblies are clamped and held by the piston nut 9 screwed into the small diameter portion 12b and the locking step portion 12c.

[0005]

[Problems to be solved by the device]

 As described above, the conventional piston rod 12 is formed with the small diameter portion 12b and the step portion 12c which are the spigot portion for mounting the piston 5 and the valve assembly which is the damping force generating member. However, there is a problem in that this work is troublesome and the processing cost increases.

Further, when the body 12a of the piston rod 12 originally has a small diameter due to the type of shock absorber, if the cutting processing is performed to form the smaller diameter portion 12b, the strength of the smaller diameter portion 12b decreases and the strength decreases. I am anxious.

Moreover, as the diameter of the small diameter portion 12b becomes smaller, the internal passage into which the rotary valve 1 is inserted also has a smaller diameter, and as a result, the rotary valve 1 also has a smaller diameter, so that the oil pressure loss is increased and a desired damping force is obtained. There is a risk that it will not be obtained.

Therefore, if the main body 12a of the piston rod 1 of this type is made thick in advance, the main body 12a becomes thicker than necessary while maintaining the strength of the small diameter portion 12b and achieving the desired size of the internal passage. There is a problem that the weight is increased.

Therefore, an object of the present invention is to provide a piston or a damping force generating member to the piston rod without cutting the piston rod, to maintain the strength of the piston rod and not to give a shock to the damping force. To provide an absorber.

[0010]

[Means for Solving the Problems]

 In order to achieve the above-mentioned object, the structure of the present invention is a shock absorber in which a piston and a damping force generating member are assembled to a piston rod, and the piston rod is moved into the cylinder through the piston and inserted spontaneously. A pipe-shaped stopper is inserted and fixed to the outer circumference of the piston rod, and the piston inserted into the lower outer circumference of the piston rod and the damping force generating member are held between the stopper and a piston nut screwed to the lower end of the piston rod. It is what

[0011]

[Action]

 When the piston nut is screwed onto the piston rod, the upper end of the piston nut and the lower end of the stopper inserted on the outer periphery of the piston rod clamp and hold the piston and the damping force generating member. Therefore, it is not necessary to form a small diameter portion or a locking step below the piston rod in order to insert and hold the piston or the like.

[0012]

【Example】

 An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows an embodiment of the present invention.

A piston rod 12 is movably inserted through a piston 5 provided with a seal 10 and a piston ring 11 in a cylinder 14, and the piston 5 is divided into a rod side chamber 16 and a piston side chamber 17 in the cylinder 14. Has been done.

The piston rod 12 is formed to have a uniform thickness over the entire length, and a pipe-shaped stopper 18 is inserted on the outer periphery of the piston rod 12 and fixed at any position by spot welding.

Below the piston rod 12, a valve seat 2, a non-return spring 3, a pressure side leaf valve 4, a piston 5, an extension side leaf valve 7, a main valve 8 and a spring 6 are sequentially arranged in series. The piston 5 and the damping force generating members arranged above and below the piston 5 are inserted and tightened by a piston nut 9 screwed to the lower part of the piston rod 12, and the upper end of the piston nut 9 and the lower end of the stopper 18 are tightened. It is held by and.

In the present invention, since the stopper 18 is attached to the piston rod 12, it is necessary to purposely cut the engaging step portion and the small diameter portion on the piston rod in order to hold the piston 5 and the like. lost.

An extension port 19 and a pressure port 20 that connect the two chambers 16 and 17 to each other are formed in the piston 5, and an extension side leaf valve 7 is openably and closably disposed at the outlet end of the extension port 19. A pressure-side leaf valve 4 is arranged to be openable and closable at the outlet end of the.

A vertical passage 21 for communicating the upper and lower chambers 16, 17 with each other and first and second lateral passages 26, 28 are formed in the piston rod 12, and the rotary valve 1 is provided in the vertical passage 21. It is rotatably inserted.

The control valve 1 is formed with a plurality of first orifices 15 and second orifices 27 having different diameters which are selectively opened and closed in the first and second lateral passages 26 and 28, respectively. ..

The first lateral passage 26 of the piston rod 12 opens into the rod side chamber 16 through a through hole 25 formed in the stopper 18, and the second lateral passage 28 includes a branch passage 22 provided in the piston 5. To the pressure port 20 via.

The rotary valve 1 is rotationally driven by the control rod 13.

The piston nut 9 is formed with a through hole 24 for communicating the vertical direction 21 with the piston side chamber 17, and the through hole 24 is opened and closed by a check valve 23.

At the time of expansion operation, the expansion side damping force is generated by the orifices 15 and 27 of the rotary valve 1 and the expansion side leaf valve 7, and at the time of compression operation, the check valve 23 opens, and the orifice 15 and the compression side leaf valve 3 press the compression side. Generates damping force.

The pressure side leaf valve 3 can be replaced with a check valve.

FIG. 2 shows another embodiment of the present invention.

This is because the reband stopper 30 is inserted and fixed to the piston rod 12, the stopper 18 is inserted into the piston rod 12 and spot welding is performed, and the upper bent portion 31 is locked to the reband stopper 30 to be firmly fixed. It was done.

FIG. 3 shows another embodiment of the present invention in which an annular groove 32 for caulking is formed in the piston rod 12, and the stopper 18 is caulked in the annular groove 32 for more secure fixing.

FIG. 4 shows another embodiment of the present invention in which an annular groove 34 for caulking is formed in the piston rod 12, and the upper end of the stopper 18 is bent and caulked and fixed in the annular groove 34. Is.

[0030]

[Effect of the device]

 According to the present invention, the following effects can be obtained.

Since the stopper is inserted and fixed to the piston rod, the stopper can cooperate with the piston nut to hold the piston or the damping force generating member.

Since the piston and the like are held by the stopper, it is not necessary to cut and process the piston rod to form the small diameter portion and the locking step portion, the workability is improved, and the processing cost can be reduced.

Since the piston rod does not have a small diameter portion and is formed to have a uniform thickness, the strength can be maintained, the rotary valve can be easily inserted inside, and it is not necessary to reduce the diameter of the rotary valve. The oil passing through the rotary valve is not restricted and the desired damping force is obtained.

Since the rotary valve is inserted, it is not necessary to purposely form the diameter of the piston rod to be large, and it is possible to prevent an increase in weight.

[Brief description of drawings]

FIG. 1 is a partially longitudinal front view of a shock absorber according to an embodiment of the present invention.

FIG. 2 is a sectional view of a stopper portion according to another embodiment of the present invention.

FIG. 3 is a sectional view of a stopper portion according to another embodiment of the present invention.

FIG. 4 is a sectional view of a stopper portion according to another embodiment of the present invention.

FIG. 5 is a partially longitudinal front view of a conventional shock absorber.

[Explanation of symbols]

 5 Piston 9 Piston Nut 12 Piston Rod 14 Cylinder 18 Stopper

Claims (1)

[Scope of utility model registration request] 1. A shock absorber in which a piston and a damping force generating member are assembled to a piston rod, and the piston rod is movably inserted into the cylinder via the piston, and a pipe-shaped stopper is provided on the outer circumference of the piston rod having a uniform thickness. A shock absorber characterized in that the piston and the damping force generating member which are inserted and fixed and are inserted into the outer periphery of the lower portion of the piston rod are held by the stopper and a piston nut screwed to the lower end of the piston rod.