JPS6053235A - Friction damper - Google Patents

Abstract

PURPOSE:To obtain different values of damping force between the push stroke and pull stroke by varying slide resistance between an elastic piston ring fitted to the outer periphery of a piston and the inner surface of a cylinder according to the relative moving direction. CONSTITUTION:A taper groove 5a is formed on the outer periphery of a piston 5 in such a manner that the depth of the groove changes in the sliding direction, that is, the depth increases rectilinearly as it goes downward. An elastic piston ring 4 tapered in section is fitted in the taper groove 5a in such a manner as to freely move up and down. The pressing force by compression deformation of the piston ring 4, that is, damping force can vary with the push stroke and the pull stroke of the piston 5.

Description

[Detailed description of the invention] The present invention relates to improvements in friction dampers.

In a friction damper in which a piston is slidably fitted into a cylinder and a piston rod extends from the piston to the outside of the cylinder, a piston 105 is fitted around the outer periphery of the piston as shown in FIG. piston ring 104
It fits into the inner periphery of the cylinder 102 through the inner periphery of the cylinder 102.

As shown in the figure, the piston ring 104 is tightly fitted to the outer periphery of the piston 105 in an immovable state, so the sliding resistance of the piston 105 is equal during the pushing and inward strokes of the damper, and this generally means that during the pushing stroke, This is disadvantageous for this type of damper, which is small and requires a large damping force during the pushing stroke.

The present invention has been made to effectively eliminate such inconveniences, and its purpose is to provide a friction damper that can change the value of the damping force in the push stroke and the pull stroke.

In a friction damper that extends from a piston rod to the outside of the cylinder, a tapered groove whose depth changes in the sliding direction of the piston is provided on the outer periphery of the piston, and an elastic piston having a tapered cross section is disposed within the tapered groove. Its feature is that the ring is fitted in a movable manner.

A preferred embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

Fig. 1 is a half-cut sectional view of the damper according to the present invention, Fig. 2 is an enlarged broken sectional view of section A in Fig. 1 during the pushing stroke, Fig. 3 is a sectional view taken along the line 3-3 in Fig. 2, and Fig. 4 1 is an enlarged broken sectional view of section A in FIG. 1 during the pulling stroke.

In the friction damper 1 shown in FIG.
A piston 5 is connected to the inner periphery via an elastic piston ring 4 and is fitted to be vertically slidable.

As shown in detail in FIG. 2, on the outer periphery of the piston 5, there is a tapered groove 5d whose depth changes in the sliding direction, that is, whose depth linearly increases downward. The elastic piston ring 4, which has a tapered cross section, is fitted into the tapered groove 5a so as to be vertically movable.

Grease passage grooves 4a are formed on the outer periphery of the piston ring 4, passing through them in the axial direction (piston sliding direction) (see FIG. 3).

3- By the way, lubricating grease is applied to the inner circumferential surface of the cylinder 2, and a front guide 6 that slides on the outer circumference of the piston rod 3 is fitted on the inner circumference of the lower end of the cylinder 2. In addition, 7 in FIG. 1 is a rebound spring.

On the other hand, a joint metal 8 is screwed onto the lower end of the piston rod 3 as shown in the figure, and a cylindrical spring guide 9 is in contact with the upper surface of the joint metal 8.

A coil spring 11 is stretched between the spring guide 9 and a spring seat 10 tied to the outer periphery of the upper end of the cylinder 2, as shown. In Fig. 1, 12 is a stop rubber, 13 is a rubber hook, 141
d rubber bushing color.

Next, the function of the present friction damper 1 will be described.

First, when the piston 5 moves upward in the cylinder 2 during the pushing stroke, the elastic piston ring 4 is located at the lower end of the tapered groove 5a of the piston 5, as shown in FIG. S4-ru. Since the depth of the tapered groove 5a increases downward, the compressive deformation of the elastic piston ring 4 in this state is small, and therefore the piston ring 4 is compressed in the cylinder 2.
The pressing force on the inner circumferential surface is also small, and the sliding resistance acting between the piston ring 4 and the cylinder 2 is also small. As a result, the damping force generated based on the sliding resistance of the piston 5 becomes relatively small during the pushing stroke. When the piston 5 slides, the grease passes through the grease passage grooves 4a formed on the outer periphery of the piston ring 4 and lubricates the sliding surface.

Next, when the damper 1 moves to the retraction stroke and the piston 5 moves downward in the cylinder 2, the elastic piston ring 4 is located at the upper end of the tapered groove 5a of the piston 5, as shown in FIG.
In this state, it moves downward together with the piston 5. Tapered groove 5
Since the depth of a decreases upward, the piston ring 4 is compressively deformed by a considerable amount between the tapered groove 5a and the cylinder 2, and the pressing force of the piston ring 4 against the inner peripheral surface of the cylinder 2 is Becomes a dog. As this pressing force increases, the sliding resistance acting on the sliding surfaces of the piston ring 4 and the cylinder 2 increases, V, and therefore the damping force generated based on this sliding resistance increases during the retraction stroke.

As described above, the damping force generated in the damper 1 can be made small in the pushing stroke and large in the pulling stroke, and the characteristics generally required for this type of damper can be satisfied.

The absolute value of the damping force can be changed arbitrarily by changing the depth of the tapered groove 5a and the material of the elastic piston ring 4.

As is clear from the above description, according to the present invention, in a friction damper, a tapered groove whose depth changes in the sliding direction of the piston is provided on the outer periphery of the piston, and an elastic piston having a tapered cross section is disposed within the tapered groove. Since the ring is movably fitted, the value of the damping force of the friction damper can be changed between the push stroke and the pull stroke.

[Brief Description of the Drawings] Fig. 1 is a half-cut sectional view of the damper according to the present invention, Fig. 2 is an enlarged broken sectional view of section A in Fig. 1 during the pushing stroke, and Fig. 3 is Fig. 2 3-3. A line sectional view, FIG. 4 is an enlarged broken sectional view of section A in FIG. 1 during the retraction stroke, and FIG. 5 is a broken sectional view showing a conventional example of a piston in a fitted state. In the drawing, 1 is a sorption damper, 2 is a cylinder,
3fd piston rod, 4 elastic piston ring, 51
[Piston 5a is a tapered groove. Patent Applicant Showa Seisakusho Co., Ltd. Agent Patent Attorney ± 2 1) Yobetsu Patent Attorney Kuni Ohashi Intention Patent Attorney Yu Koyama -7 ~ Figure 4 Figure 5 a

Claims (1)

[Claims] In a friction damper, in which a piston is slidably fitted in a cylinder with a piston ring fully closed, and a piston rod extends from the piston to the outside of the cylinder, the outer periphery of the piston has a depth in its sliding direction. A friction damper characterized in that a tapered groove that changes is provided, and an elastic piston ring having a tapered cross section is movably fitted into the tapered groove.