JPH05346137A - Magnetic connection type enclosed oil damper - Google Patents

Abstract

PURPOSE:To provide a magnetic connection type enclosed oil damper which is capable of realizing the sealing of the working oil and the reliable sliding by using a center shaft and an inner bushing. CONSTITUTION:In a magnetic connection type enclosed oil damper, a center shaft 9 where the outer dimensions can be accurately obtained is provided inside an inner cylinder 3, and an inner bushing 10 of low friction by making use of e.g. the rolling of a ball inside a yoke 5, realizing the sealing function of the working oil and the reliable sliding function by securing the appropriate clearance between the yoke and the inner cylinder 3. Thus, a directly-driven oil damper is obtained where the low friction sliding of the yoke and the reliable sealing of the working oil are realized.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention eliminates leakage of hydraulic oil from sliding parts, etc. by completely sealing the hydraulic oil in an oil damper having an excellent cushioning capacity, and is used under maintenance-free condition for a long time. The present invention relates to a direct-acting oil damper for vacuum (for space use), which is required to secure the cushioning performance and to eliminate contamination of peripheral devices due to leakage.

[0002]

2. Description of the Related Art FIG. 4 is a view showing a conventional magnetic coupling type oil damper. In the figure, 1 is an outer cylinder, 2 is a permanent magnet, 3 is an inner cylinder, 4 is an outer bushing, 5 is a yoke, 6a and 6b are coil springs, 7 is a working fluid, and 8 is a through hole.

The characteristic of the conventional magnetic coupling type oil damper is that the yoke 5 moves inside the inner cylinder 3 by the non-contact coupling force of the permanent magnet 2 as the outer cylinder 1 and the inner cylinder 3 move relative to each other. The working fluid 7 sealed in the cylinder passes through the small through hole 8 provided in the yoke 5 to achieve the damping effect.

[0004]

However, in the conventional magnetic coupling type oil damper, the yoke 5 is attracted to one side by the force of the permanent magnet 2, and the outer periphery of the yoke 5 that reciprocates linearly in the inner cylinder 3. Since the inner wall of the inner cylinder 3 makes an offset contact, there is a problem in that it is difficult to realize reliable sealing with a seal of the hydraulic oil 7 and less friction.

Further, since the through hole 8 for determining the damping characteristic of the oil damper is inside the sealed inner cylinder 3, the damping characteristic (coefficient of viscous resistance) cannot be easily adjusted from the outside. However, there is a problem that it is not possible to absorb an abnormal pressure change of the incompressible hydraulic oil due to the above.

The present invention has been made in order to solve the above problems, and a magnetic coupling type hermetic seal capable of realizing a hydraulic oil seal and reliable sliding by using a center shaft and an inner bushing. The purpose is to obtain a type oil damper.

Further, by providing the adjusting valve and the diaphragm, it is possible to externally adjust the damping characteristic (coefficient of viscous resistance) and obtain a magnetic coupling type oil damper capable of absorbing an abnormal pressure change of the hydraulic oil. This is the purpose.

[0008]

SUMMARY OF THE INVENTION A magnetic coupling type oil damper according to the present invention is provided with a center shaft inside an inner cylinder, which is easy to obtain external dimension accuracy, and inside the yoke, a low friction utilizing, for example, rolling of balls. The inner bushing is provided to ensure an appropriate clearance between the yoke and the inner cylinder, thereby achieving the function of sealing the working fluid and the reliable sliding function.

Further, the magnetic coupling type oil damper according to the present invention uses the center shaft to guide the flow path of the working fluid to the return hole provided at one end of the inner cylinder, and to provide the adjusting valve there. The damping characteristics (coefficient of viscous resistance) can be adjusted from the outside, and a diaphragm is provided at the other end of the inner cylinder to absorb an abnormal pressure change of the working fluid.

[0010]

The magnetically coupled closed type oil damper according to the present invention achieves the function of sealing the working fluid and the reliable sliding function by ensuring a proper clearance between the yoke and the inner cylinder, and at the same time, as the adjusting valve, By providing a diaphragm, a damping function adjustment function and a working fluid pressure change absorption function are achieved, and high-performance vacuum (space)
A direct-acting oil damper can be realized.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing an embodiment of the present invention. In the figure, 1 is an outer cylinder that covers the outer circumference of the damper, 2 is a plurality of permanent magnets incorporated in the outer cylinder 1,
Reference numeral 3 denotes an inner cylinder that reciprocates linearly inside the permanent magnet 2, 4a and 4b are outer bushings incorporated in the outer cylinder 1 to support the movement of the inner cylinder 3, and 5 is magnetically coupled to the permanent magnet 2. By doing so, the yokes 6a, 6b which reciprocate linearly inside the inner cylinder 3 in accordance with the movement of the permanent magnet are fixed inside the inner cylinder 3, one end of which is fixed to the inner cylinder and the other end of which is fixed to the yoke 5. Coil spring, 7 is a working fluid sealed inside the inner cylinder 3 including the inside of the through hole 8 described below, 8 is a through hole located in the central axis of the center shaft 9 described below, and 9 is both ends inside the inner cylinder 3. A center shaft 10 fixed to the center shaft 10 is incorporated inside the yoke 5 to support the reciprocating linear motion of the yoke with respect to the center shaft 9. Runner is a bushing.

2 and 3 are views showing another embodiment of the present invention. FIG. 2 shows a neutral state of the magnetic coupling type oil damper, and FIG. 3 shows a compression operation of the magnetic coupling type oil damper. The latter state is shown. In the figure, 11 is a return hole for returning the working fluid 7 from the through hole 8 in the center of the center shaft 9 into the inner cylinder, 12 is a regulating valve screwed to one end of the inner cylinder 3, 13 is the regulating valve 1
2 is a taper portion which adjusts the effective sectional area of the return hole 11 by the screwing position of the adjusting valve, and 14 is a diaphragm provided at the other end of the inner cylinder 3 and connected to the through hole 8.

The operation of the magnetic coupling type oil damper constructed as described above will be described with reference to FIGS. 1 and 2 showing the neutral state and FIG. 3 showing the state after the compression operation.

The inner cylinder 3 moves downward in the figure by the compressive force applied to the inner cylinder 3 with respect to the outer cylinder 1. At this time, the yoke 5 relatively moves inside the inner cylinder by the magnetic coupling force with the external permanent magnet 2, and the working fluid 7 on the upper part of the yoke flows into the lower part of the yoke through the through hole 8 in the center of the center shaft 9. . The working fluid produces viscous resistance when passing through the through hole or the like, and the coil spring 6 produces a restoring force proportional to the displacement of the yoke. The inner cylinder 3 is supported by the outer bushing 4, and the yoke is supported by the inner bushing 10 and the center shaft 9. In addition, the working fluid is returned from the upper portion of the yoke to the through hole, and the return hole 11 and the adjusting valve 12 are provided.
Since it passes through the taper portion 13 at the tip, it is possible to change the effective cross-sectional area of the return hole 11 by adjusting the screwing amount of the adjusting valve and changing the position of the taper portion, and as a result, it is possible to adjust the viscous resistance. Further, the other end of the through hole reaches the diaphragm 14, and absorbs the pressure change of the working fluid due to the temperature change of the damper or the like as the internal volume change of the inner cylinder due to the diaphragm moving up and down in the figure.

[0015]

As described above, according to the present invention, a direct-acting oil damper for vacuum (for space use) having excellent cushioning performance can be used to completely remove oil, which is hydraulic oil, by using the magnetic coupling force of a permanent magnet. When closed, the yoke's reciprocating linear movement is supported with high precision by the low friction inner bushing and the center shaft, so that the yoke is attracted to one side by the permanent magnet and contacts the inner cylinder as in the conventional case. Sliding friction does not increase or the working fluid seal at the yoke does not become incomplete, low friction sliding of the yoke and reliable sealing of the working fluid are realized, and a direct acting oil damper with excellent cushioning performance is provided. It has the effect of being obtained.

Further, in the present invention, since the taper portion for adjusting the effective sectional area of the flow passage of the working fluid is provided at the inner cylinder end portion, the viscous resistance of the damper can be easily adjusted from the outside. Has the effect of becoming.

Further, in the present invention, since the diaphragm is provided at the end of the inner cylinder to change the volume of the working fluid inside the inner cylinder, the pressure change of the working fluid due to the temperature change of the damper is absorbed. This has the effect of realizing a highly reliable damper.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a magnetic coupling type oil damper according to an embodiment of the present invention.

FIG. 2 is a sectional view showing a magnetic coupling type oil damper according to another embodiment of the present invention.

FIG. 3 is a cross-sectional view showing the operating state of FIG.

FIG. 4 is a cross-sectional view showing a conventional magnetic coupling type oil damper.

[Explanation of symbols]

 1 Outer Cylinder 2 Permanent Magnet 3 Inner Cylinder 4 Outer Bushing 5 Yoke 6 Coil Spring 7 Working Fluid 8 Through Hole 9 Center Shaft 10 Inner Bushing 11 Return Hole 12 Control Valve 13 Taper Part 14 Diaphragm

Front Page Continuation (72) Inventor Eiichi Endo 2-1-1 Sengen, Tsukuba City, Ibaraki Space Development Center Tsukuba Space Center (72) Inventor Jun Nakagawa 325 Kamimachiya, Kamakura City Mitsubishi Electric Corporation Kamakura Factory

Claims (3)

[Claims] 1. An outer cylinder that covers an outer periphery, a permanent magnet incorporated in the outer cylinder, an inner cylinder that reciprocates linearly inside the permanent magnet, and an inner cylinder incorporated in the outer cylinder. A supporting outer bushing, a center shaft having both ends fixed inside the inner cylinder and a through hole in the center, and a reciprocating straight line inside the inner cylinder according to the movement of the permanent magnet by magnetically coupling with the permanent magnet. A moving yoke; an inner bushing that is incorporated inside the yoke and supports reciprocating linear movement of the yoke with respect to the center shaft; a coil spring that is inside the inner cylinder and has one end fixed to the inner cylinder and one end fixed to the yoke; Sealed inside the inner cylinder including the through hole of the center shaft A magnetic coupling type oil damper, which is composed of a working fluid. 2. A control valve having a return hole for returning a working fluid from a through hole at the center of the center shaft into the inner cylinder at the end of the inner cylinder, and a taper portion for adjusting the cross-sectional area of the return hole from the outside. The magnetic coupling type oil damper according to claim 1, further comprising: 3. The other end of the inner cylinder is provided,
2. The magnetic coupling type oil damper according to claim 1, further comprising a diaphragm connected to a through hole at the center of the center shaft to absorb a pressure change of the working fluid.