JPH0516418Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Field of Industrial Application) The present invention relates to a valve structure for a shock absorber used in motorcycles, automobiles, etc.

(Prior Art) As a valve structure for a vehicle shock absorber, the one shown in FIG. 5 is known as one that exhibits damping during expansion or compression.

FIG. 5 shows the valve structure on the extension side. Specifically, a piston rod 101 is inserted into the cylinder 100, a piston 102 is fixed to the lower end of the piston rod 101, and the piston 102 is fixed to the lower end of the piston rod 101.
An oil hole 103 is formed in 02, an inner round surface 104 is formed radially inward from the oil hole 103, and a protrusion 105 is formed radially outward from the oil hole 103, and the upper surface of this protrusion 105 is an inner round surface 104. Outer round surface 106
A sizing groove 107 is formed in this outer round surface 106.

A valve seat 108 and a collar 109 are fitted on the outer periphery of the piston rod 101 above the piston 102, and a plurality of plate valves 110 and check valves 111 are stacked and slidably attached to the outer side of the collar 109. and close the square hole 112 of the check valve 111,
The outer periphery of the check valve 111 is connected to the spring 11.
3, it is pressed against the outer round surface 106.

When the stroke speed of the piston 102 is low, the damping force is determined by the sizing groove 107, when the stroke speed is medium, the damping force is determined by the rigidity of the plate valve 110, and when the stroke speed is high, the damping force is determined by the square The damping force on the extension side is determined by the hole.

(Problems to be Solved by the Invention) In order to obtain a stable damping force without variation with the above-mentioned conventional valve structure, the plate valve 110 and the check valve 111 should be in contact with each other without any gap in the assembled state. Furthermore, the outer circumference of the check valve 111 must be in contact with the outer round surface 106 without any gaps.

For this purpose, the height h of the protrusion 105,
The overlapped thickness h' of the valve seat 108 and the plurality of plate valves 110 must be equal. However, the shingle plate valve 110 and the valve seat 10
It is difficult to manufacture the thickness of 8 without error, and the above-mentioned gap occurs, making it difficult to obtain a stable damping force.

Further, in the conventional valve structure, the number of plate valves can only be changed within a range that does not change the predetermined total thickness, and adjustment of the damping force is also troublesome.

(Means for Solving the Problems) In order to solve the above problems, the present invention provides a valve block that defines an oil chamber of a shock absorber, a plurality of oil holes that communicate both oil chambers, and one end of the oil hole. A plate-shaped check valve is fitted into this annular groove via a spring so that its inner periphery can slide, and a round surface is formed on the inner periphery of the annular groove. The plate valve is brought into contact with this round surface, and an inner fixing member is provided that can be pressed and fixed according to the thickness of the plate, and the check valve is brought into contact with the outer periphery of the annular groove at the same time as the plate valve. The present invention is characterized in that an outer fixing member having a sheet surface formed thereon is provided separately from the inner fixing member.

(Function) Since the inner fixing member and the outer fixing member are separate bodies, the valve mechanism can be assembled without gaps being formed between the plate valve and the check valve and between the check valve and the seat surface. can.

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

FIG. 1 is a cross-sectional view of a shock absorber to which the valve structure according to the present invention is applied. ,
A sealing member 5 is held on this rod guide 3 by a holder 4, and a piston rod 6 is inserted into the inner tube 2 from above through the rod guide 3 and sealing member 5, and an extension side valve mechanism 7 is attached to the lower end of this piston rod 6. A compression side valve mechanism 8 is also provided at the lower edge of the inner tube 2.

Next, the structures of the expansion side valve mechanism 7 and the compression side valve mechanism 8 will be described below based on FIGS. 2 and 3.

First, the rebound side valve mechanism 7 is connected to the piston rod 6.
A piston 10 serving as a valve block slides on the inner peripheral surface of the inner tube 2 at the small diameter portion 6a at the lower end.
is externally fitted, and a plurality of oil holes 11...
and an annular groove 40 connecting one end thereof, the lower end radially inward of the annular groove 40 is an inner round surface 12, and the lower end radially outward than the annular groove 40 is an outer round surface 13. There is.

An inner nut 14 serving as an inner fixing member is screwed from below onto the threaded portion 6b carved at the lower end of the piston rod 6, and a valve seat 15 is inserted between the upper end surface of the inner nut 14 and the inner round surface 12 of the piston 10. and the inner peripheral portions of the plurality of plate valves 16 are held between them.

Further, a threaded portion is carved on the outer periphery of the inner nut 14, and an outer nut 17 serving as an outer fixing member is screwed into this threaded portion from below.
The upper end seat surface 18 of the piston 10 is brought into contact with the outer round surface 13 of the piston 10. An oil hole 19 is formed in the outer nut 17, and a sizing groove 20 is formed in the upper end sheet surface 18.

Further, a spring 2 is provided on the upper surface of the plate valve 16.
The lower surface of the check valve 22 energized at step 1 comes into contact, the lower surface of the outer periphery of the check valve 22 contacts the seat surface 18 of the outer nut 17, and the square hole 23 formed in the check valve 22 is connected to the plate valve. It is closed at 16. Here, inner nut 1
4 and the outer nut 17 are separate bodies, so after the plate valve 16 is held between the inner nut 14 and the inner round surface 12, the outer nut 17 is held so that its upper end seat surface 18 touches the lower surface of the outer periphery of the check valve 22. Since the check valve 22 and the plate valve 16 or the seat surface 18 can be tightened until they touch each other, no gap is formed between the check valve 22 and the plate valve 16 or the seat surface 18.

The compression side valve mechanism 8 is attached to the lower end of the inner tube 2 as a first bottom piece 2 as a valve block.
A plurality of oil holes 25... and an annular groove 40 connecting one end side thereof are formed in the first bottom piece 24, and the lower surface radially inward from the annular groove 40 is formed into an inner round surface. 26, the lower surface radially outward of the annular groove 40 is an outer round surface 27, and a fixing nut 28 as an inner fixing member is press-fitted or screwed into the center of the first bottom piece 24. A valve seat 30 and a plurality of plate valves 31 are sandwiched between the upper surface of the flange portion 29 and the inner round surface 26, and the first bottom piece 24 serves as an outer fixing member fixed to the bottom of the outer tube 1. 2 is fitted onto the bottom piece 32 from above. This second bottom piece 3
A sizing groove 34 is formed in the upper end seat surface 33 of the valve plate 31, and the lower surface of a check valve 36, which is biased by a spring 35, is in contact with the upper surface of the plate valve 31. A square hole 37 that is closed is formed, and the lower surface of the outer periphery of the check valve 36 is in contact with the seat surface 33. Here, even in the compression side valve mechanism 8, since the fixing nut 28 and the second bottom piece 32 are separate bodies, the check valve 36 is in close contact with both the plate valve 31 and the seat surface 33.

The operation of the valve structure as described above will be explained with reference to FIG. 4, taking the extension side valve mechanism 7 as an example.

During the shock absorber extension process, oil tends to flow from the oil chamber S1 above the piston 10 to the oil chamber S2 below, so the check valve 22 is pushed downward. If the piston speed during this elongation process is low, the oil in the oil chamber S1 will flow through the sizing groove 20.
The square hole 23 remains closed by the plate valve 16. On the other hand, when the piston speed becomes medium to high speed, oil chambers S1 and S2
When the pressure difference becomes large and the plate valve 16 is bent downward as shown in FIG. When the flow path P is wider than the square hole 23 (high speed), the damping force is generated depending on the square hole 23.

In the embodiment, a sizing groove is provided in order to generate damping force at low speeds, but a slit valve may be provided in place of this sizing groove.

(Effects of the invention) As explained above, according to the invention, in the valve structure of a shock absorber configured by stacking a plate valve and a check valve having a square hole, the plate valve is fixed by an inner fixing member. Since the outer circumference of the check valve is pressed against the inner round surface and brought into contact with the seat surface of the outer fixing member which is assembled separately from the inner fixing member, there is no gap between the check valve and the plate valve or the seat surface. A stable damping force is generated because there is no gap between the valves and it is easy to give an initial preset to the valve.
Furthermore, since the total thickness of the plate valve can be changed without changing other parts, it is possible to set a wide range of damping force specifications.

[Brief explanation of the drawing]

Figure 1 is a sectional view of a shock absorber to which the valve structure according to the present invention is applied, Figures 2 and 3 are enlarged sectional views of the expansion side and compression side valve mechanisms, and Figure 4 shows the action of the expansion side valve mechanism. The described cross-sectional view, FIG. 5, is a cross-sectional view of a conventional valve structure. In the drawings, 1 is an outer tube, 2 is an inner tube, 7 is an extension side valve mechanism, 8 is a compression side valve mechanism, 10 and 24 are valve blocks (corresponding to the piston and the first bottom piece, respectively), 12,
26 is an inner round surface, 13, 27 is an outer round surface, 14, 28 is an inner fixing member, 16, 31 is a plate valve, 17, 32 is an outer fixing member, 22, 3
6 is a check valve, and 40 is an annular groove.

Claims (1)

[Scope of utility model registration request] In the valve structure of a buffer, an oil chamber in the buffer is defined by stacking a plate-shaped check valve having a square hole and a flexible plate valve that closes the square hole of the check valve. A plurality of oil holes that communicate both oil chambers and an annular groove connecting one end of the oil holes are formed in the valve block, and the inner periphery of the check valve can slide into this annular groove via a spring. Further, an inner fixing member is provided which forms a round surface on the inner peripheral edge of the annular groove, allows the plate valve to abut against the round surface, and fixes the plate valve by pressing according to the thickness of the plate. Further, an outer fixing member is provided on the outer periphery of the annular groove, and is separate from the inner fixing member and has a seat surface that comes into contact with the plate valve at the same time as the check valve comes into contact with the plate valve. .