JPH0424193Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to an improvement in a damping valve structure used in a rear suspension unit of a two-wheeled vehicle.

(Prior Art) In order to generate damping force in a rear-action unit, a damping valve is used that applies resistance on the extension side or compression side of the piston to the flow of hydraulic oil into and out of the upper and lower oil chambers defined by the piston. , has conventionally been configured as shown in FIG.

1 is a piston, 2 is a piston rod, 3 is a compression side passage formed in the piston 1, 4 is a compression side damping valve that opens and closes this passage 3, and the compression side damping valve 4 is made up of a plurality of stacked annular plate valves 5, and a piston nut. 6.

The inner periphery of the plate valve 5 is clamped between an annular support (spacer) 7 and a support pedestal 8 of the piston 1, and the outer periphery of the valve is pressed against the seat 9 of the piston 1.

Further, 10 is a holder disposed outside the support 7, 11 is a growth side damping valve, and 12 is a growth side passage. In addition, the expansion side damping valve 11 is also basically configured in the same manner as the compression side damping valve 4.

As shown in FIG. 5, when the piston operates on the pressure side, hydraulic oil flows from the pressure side passage 3 by pushing open the pressure side damping valve 4. A damping force is generated by the resistance when the compression side damping valve 4 is bent and opened.

During expansion side operation, the expansion side damping valve 11 is pushed open and hydraulic oil flows from the expansion side passage 10. At this time, the compression side damping valve 4 is pressed against the seat portion 9 and closed.

(Problems to be Solved by the Invention) However, in such a conventional valve structure, the support outer diameters of the support 7 and the support pedestal 8 that support the compression side damping valve 4 are the same;
As shown in FIG. 6, bending stress acts on the same position of the plate valve 5 on the expansion side and the compression side, resulting in a problem that the durability of the valve is impaired.

That is, as shown by the solid line, when the compression side damping valve 4 opens on the compression side stroke, the maximum bending stress is generated at the support point A of the corner that contacts the support 7, and as shown by the imaginary line, When closing in the extension stroke, large bending stress is generated at the support point A at the corner of the support pedestal 8 and at the support point B at the inner corner of the seat portion 9.

As is clear from the figure, since the diameters of the support 7 and the support pedestal 8 are the same, the support point A is at the same position, and therefore, the maximum stress of the plate valve 5 is generated at the same position on both the expansion side and the compression side. This concentrated stress significantly impairs durability.

The present invention aims to solve such problems by simple means.

(Means for Solving the Problems) Therefore, the present invention involves sandwiching the inner circumference of an annular plate valve between a piston support base and an annular support, and forming the outer circumference of this plate valve into a piston. In the damping valve structure, the support surface of the support pedestal is formed to have a larger outer diameter than the support, and the support pedestal is configured to have a larger outer diameter than the support, and to face the plate valve with the first support in between. A second independent disk-shaped support having a larger diameter than the support was provided.

(Function) Therefore, when the plate valve is pushed open by the hydraulic oil, stress increases at the outer diameter corner of the support, and when pressure on the closing side acts on the plate valve, the support Stress increases at the corners of the pedestal,
Since the support point of the support pedestal is different from the support point of the support, the point of application of stress on the plate valve on the closing side is at a different position than on the open side, and concentration of stress on the plate valve is avoided. Ru.

(Example) Hereinafter, an example of the present invention will be described based on the drawings.

In FIG. 1, first and second supports 7A and 7B are provided to support the plate valve 5 constituting the compression side damping valve 4.

The first and second supports 7A and 7B have different outer diameters, and the outer diameter of the second support 7B located on the outside is larger than the outer diameter of the first support.

Further, the diameter of the support surface of the support pedestal 8 is set larger than the diameter of the first support 7A, and preferably smaller than the outer diameter of the second support 7B.

The structure is as described above, and other parts that are the same as those of the conventional example are given the same reference numerals, and the operation will be explained next.

As shown in FIG. 2A, when the pressure side is operated, the plate valve 5 is bent and opened by the hydraulic oil flowing through the pressure side passage 3, and a damping force is generated accordingly.

In the region where the piston speed is low, the inner circumference of the plate valve 5 is supported only by the first support 7A, but as the piston speed increases, it begins to flex significantly, and eventually the second support 7B also deflects. come into contact with each other.

In this way, even in the high speed range where the greatest stress is applied to the damping valve 4, the plate valve 5 is supported at its inner circumferential portion and intermediate portion, as shown in FIG. Although the stress is high at two points, support points A and C, which are the corners of the first support 7A and the second support 7B, the stress is distributed overall. Therefore, it is also possible to prevent the maximum value of bending stress from becoming excessive.

Further, as shown in FIG. 2B, during the expansion side operation, the compression side damping valve 4 closes in close contact with the seat portion 9, but at this time, it bends around the outer periphery of the support pedestal 8 and the seat portion 9 as fulcrums. Therefore, the bending stress increases at these support points D and B, but the support point D is at an intermediate position different from the support points A and C, and therefore the plate valve 5 is at a position different from the pressure side. There is a maximum point of stress and concentrated stress action on the plate valve 5 is avoided.

Furthermore, in the above, by changing the position of the bending fulcrum of the leaf spring 5 by the supports 7A and 7B, the generation characteristics of the damping force can be changed, and the optimum damping force can be applied according to the request. .

In addition, in the said Example, although this invention was applied and demonstrated to the compression side valve 4, it cannot be overemphasized that it is applicable also to the expansion side valve 11.

(Effects of the invention) As described above, according to the invention, it is possible to disperse the stress acting on the plate valve in the expansion side and compression side strokes, thereby preventing damage to the valve and improving durability.

In addition, in this invention, an independent disk-shaped support is provided as the second support, so when changing or adjusting the damping force characteristics, it is necessary to use a second support with the same outer diameter but different thickness. All you have to do is prepare one and change it. In this case, the plate thickness can be controlled with great precision, so the damping force can be set or adjusted accurately.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention, FIGS. 2A and 2B are sectional views showing the operating state, respectively.
Fig. 3 is an operating characteristic diagram showing the state of stress generation on the expansion side and compression side, Fig. 4 is a sectional view of the conventional example, Fig. 5 is a sectional view also showing the operating state, and Fig. 6 is the state of stress generation. FIG. 1... Piston, 3... Compression side passage, 4... Damping valve, 5... Plate valve, 7A, 7B... Support, 8... Support pedestal, 9... Seat part, 10...
holder.

Claims (1)

[Scope of utility model registration request] In the damping valve structure, the inner circumferential portion of the annular plate valve is held between the support base of the piston and the annular support, and the outer circumferential portion of the plate valve is pressed against a seat portion formed on the piston. The outer diameter of the support surface of the support pedestal is formed to be larger than that of the support, and a second independent disk-shaped second support having a larger diameter than the support and facing the plate valve with the first support in between is formed. A damping valve structure characterized by the provision of support.