JPH01295040A - Fluid damper - Google Patents

Abstract

PURPOSE:To drastically easily adjust the vibration attenuation characteristic of a liquid damper by forming communication passages at plural positions in the circumferential and radial directions, having the working shaft of a piston as center and charging two fluid chambers with the electric viscous fluid. CONSTITUTION:In a liquid damper 10, communication passages 14 are formed at plural positions in the peripheral direction and radial direction, setting the working shaft 15 of a piston 12 as center. A pair of electrodes 19 are installed onto the opposed inner surfaces, having the communication passage 14 of the piston 12 interposed. Two fluid chambers 13A and 13B are charged with the electric viscous fluid which possesses the Winslow effect. The viscosity of the fluid which passes through the communication passage 14 of the piston 12 is controlled by increasing the viscosity of the electric viscous fluid, and the throttle resistance of the fluid in the communication passage 14 is controlled. Thus, the vibration attenuation characteristic of the fluid damper 10 can be adjusted drastically easily.

Description

[Detailed Description of the Invention] [Industrial Field of Application] The invention is not yet inventive.
The present invention relates to fluid dampers widely used in various other devices.

[Prior art] Conventionally, hydraulic fluids such as oil or air have been used as fluid dampers.
A piston is provided within the damper case, and two fluid chambers partitioned by the piston are formed within the damper case,
The piston is provided with an orifice that communicates the two fluid chambers, an operating shaft fixed to the piston extends inside and outside the damper case, and a vibrating body is connected to the operating shaft.

[Issue 8 to be solved by the invention] The vibration damping characteristics of the conventional fluid damper described above are fixed depending on the shape of the orifice and the characteristics of the working fluid.

Therefore, if the fluid damper described above is used in a vibration system different from its original design conditions, an optimal vibration damping effect cannot be obtained. As designed, this means that the fluid damper does not dampen smaller-scale vibrations (high-frequency vibrations without large displacements) and slower-paced vibrations with larger wavelengths than normal.

Furthermore, when the fluid damper is used in a vibration system whose vibration state changes over time, it cannot effectively damp the vibrations.

Note that it is desirable for the fluid damper to effectively damp vibrations generated in the piston even in a vibration system in which the moving speed of the piston changes rapidly.

Furthermore, in a fluid damper, fluid pressure is almost always applied to the piston, and the piston needs to be as simple and robust as possible in structure.

An object of the present invention is to extremely easily adjust the vibration damping characteristics of a fluid damper and to provide an optimal vibration damping effect to a vibration system.

An object of the present invention is to simply configure a piston of a liquid damper and make it robust.

[Means for Solving the Problems] The present invention according to claim 1 provides a piston in a damper case, forms two fluid chambers partitioned by the piston in the damper case, and provides the piston with the two fluid chambers in the damper case. A communication path is provided to communicate the fluid chambers, and an operating shaft fixed to the piston is connected to multiple positions in the circumferential direction and radial direction around the operating shaft of the piston in a fluid damper that extends inside and outside the damper case. A passage is provided, a pair of electrodes are provided on inner surfaces facing each other with each communication passage in between, and the two fluid chambers are filled with an electrorheological fluid having a Winslow effect.

In the present invention according to claim 2, the piston is provided with three or more ring-shaped electrodes coaxially around the operating axis of the piston body, and the ring-shaped electrodes are spaced apart in the circumferential direction of a region sandwiched between adjacent ring-shaped electrodes. A plurality of block-shaped insulators are arranged, and a communication path is defined by adjacent ring-shaped electrodes and adjacent block-shaped insulators.

[Operation] First, the electrorheological fluid having the Winslow effect, which is essential to the configuration of the present invention, will be explained.

The Winslow effect is 1347W M W+nsl
It was first disclosed in U.S. Pat. ) is filled with a suspension of so-called electrorheological fluid and a voltage is applied between two electrodes, the viscosity of the fluid increases due to the influence of an external electric field. Not only can this viscosity be externally controlled by the magnitude of the external electric field, but it can also be expected to have excellent effects in that it has very good responsiveness.

Microcrystalline cellulose, silica gel, soybean casein, mica, etc. are known as the above-mentioned dispersed phase, and silicone oil, diphenyl chloride, dibutyl sebacate, etc. are known as the dispersion medium, and the effect is remarkable depending on the combination of each. Become.

Therefore, in the present invention according to claim 1, a pair of electrodes are provided on the inner surfaces of the piston facing each other across the communication path,
In addition, since the two fluid chambers formed in the damper case are filled with an electrorheological fluid having a Winslow effect, applying a voltage between the electrodes increases the viscosity of the electrorheological fluid sandwiched between the inner electrodes. becomes. Therefore, the viscosity of the fluid passing through the communication passage of the piston is controlled, and as a result, the throttling resistance of the fluid in the communication passage is adjusted, and the vibration damping characteristics of the fluid damper can be adjusted. In other words, by appropriately controlling the voltage applied between both electrodes according to the position, speed, direction of movement, etc. of the piston with respect to the damper case, the vibration damping characteristics of the fluid damper can be adjusted extremely easily and optimized for the vibration system. It is possible to provide a vibration damping effect. As a result, the fluid damper of the present invention can effectively damp not only normal vibration levels, but also small-scale vibrations and gentle vibrations with larger wavelengths than normal. Further, even in a vibration system whose vibration state changes over time, the vibrations can be effectively damped.

By the way, the above-mentioned viscosity increasing property of electrorheological fluid due to electric field tends to weaken as the shear rate increases. According to the present invention as set forth in claim 1, an extremely large number of communication passages can be provided in the circumferential direction and radial direction of the piston.

Therefore, even when the moving speed of the piston is large,
The fluid velocity (shear velocity) passing through the communication path can be set low. Therefore, even in a vibrating system where the moving speed of the piston changes rapidly, the viscosity increase characteristic due to the electric field of the electrorheological fluid passing through the communication path is prevented from weakening, and the vibrations transmitted to the piston are effectively damped. can.

Furthermore, in the present invention as set forth in claim 2, when the piston is provided with the electrodes and the insulator, an extremely large number of communication paths sandwiched between the electrodes can be formed by simply combining the electrodes and the insulator. . I want to do it, 1! ! , the piston of the body damper is simply configured.

It can be made robust.

[Example] FIG. 1 is a longitudinal cross-sectional view showing an example of the present invention, and FIG. S2 is a cross-sectional view of FIG. 1.

The fluid damper IO is provided with a piston 12 inside a damper case 11, and forms two fluid chambers 13A and 13B partitioned by the piston 12 inside the damper case 11. 13A,
13B is provided, and an operating shaft 15 fixed to the piston 12 extends inward and outward at both ends of the damper case 11. In addition, 16 is a piston ring, 1
7 is a sealing member.

Here, the fluid damper IO is provided with the above-mentioned communication passages 14 at a plurality of positions in the circumferential direction and the radial direction around the actuating shaft 15 of the piston 12.

Note that the piston 12 of the fluid damper IO is as follows.

Three or more ring-shaped electrodes 19 (four in this embodiment) are provided coaxially around the operating shaft 15 of the piston body 18, and are spaced apart in the circumferential direction of the area sandwiched between adjacent ring-shaped electrodes 19. A plurality of block-shaped insulators 20 are arranged. Further, the piston 12 connects the adjacent ring-shaped electrodes 19 and the adjacent block-shaped insulators 20 to the above-mentioned communication path 1.
4. Note that adjacent ring-shaped electrodes 19 have mutually different polarities (positive electrode and negative electrode).

Furthermore, the fluid damper 10 includes the two fluid chambers 13A,
13B is loaded with an electrorheological fluid having a Winslow effect.

Note that a voltage source V is connected between adjacent electrodes 19 . The voltage source V can be taken in from the extending end of the actuating shaft 15 located outside the damper case 11. Further, the voltage source V may be built into the piston 12 or the actuating shaft 15.

Next, the operation of the above embodiment will be explained.

In the fluid damper IO, a pair of electrodes 19, 19 are provided on the inner surfaces of the piston 12 facing each other across the communication path 14, and windows are provided in the two fluid chambers 13A and 13B formed inside the damper case 11. Since the electrorheological fluid having a wax effect is loaded, applying a voltage between the two electrodes 19 and 19 causes the electrorheological fluid to flow through the communication path 14 from the fluid chamber 13A to the fluid chamber 13B or vice versa. An electric field perpendicular to the flow of the electrorheological fluid is formed, increasing the viscosity of the electrorheological fluid sandwiched between the electrodes 19 and 19. Therefore, the viscosity of the fluid passing through the communication passage 14 of the piston 12 is controlled, and as a result, the throttle resistance of the fluid in the communication passage 14 is adjusted, and the vibration damping characteristics of the fluid damper 10 can be adjusted.

That is, by appropriately controlling the voltage applied between both electrodes 19, 19 according to the position, speed, moving direction, etc. of the piston 12 with respect to the damper case 11, the vibration damping characteristics of the fluid damper 10 can be adjusted extremely easily. Therefore, an optimal vibration damping effect can be imparted to the vibration system. As a result, the fluid damper IO can effectively damp not only normal vibration levels, but also smaller-scale vibrations and gentler vibrations with larger wavelengths than normal. Further, even in a vibration system whose vibration state changes over time, vibrations can be effectively damped.

By the way, the above-mentioned viscosity increasing property of electrorheological fluid due to electric field tends to weaken as the shear rate increases. At this time, the fluid damper 10 has an extremely large number of communication passages 1 in the circumferential direction and radial direction of the piston 12.
4 can be provided, and therefore, even when the moving speed of the piston 12 is high, the fluid speed (shearing speed) passing through the communication path 14 can be set low. Therefore, even in a vibrating system where the moving speed of the piston 12 changes rapidly, the viscosity increasing characteristic due to the electric field of the electrorheological fluid passing through the communication path 14 is prevented from weakening, and the vibration transmitted to the piston 12 is effectively reduced. can be attenuated.

In addition, in the fluid damper 10, when the electrode 19 and the insulator 20 are provided on the piston 12, the electrodes 19, 19 and 19 are
A very large number of communication passages 14 can be formed between the two. Therefore, the piston 12 of the fluid gunba lO can be simply configured and made robust.

In the above embodiment, the communication path 1 of the piston 12
A pair of electrodes 1 are formed on each inner surface facing each other with 4 in between.
9.19, each '41t pole 19.19 was provided in a range corresponding to the entire length of the a passage 14 in the piston 12 from one open end to the other open end. However, in carrying out the present invention, the electrodes 19 and 19 are provided only at positions corresponding to one open end of the communication passage 14 in the piston 12, or between one open end and the other open end of the communication passage 14. They may be provided only at the corresponding positions. In this case as well, the viscosity of the electrorheological fluid sandwiched between the electrodes 19 and 19 can be increased, and the restriction resistance of the fluid in the communication path 14 can be adjusted.

[Effects of the Invention] As described above, according to the present invention as set forth in claim 1, the vibration damping characteristics of the fluid damper can be adjusted extremely easily, and an optimal vibration damping effect can be imparted to the vibration system. .

Furthermore, according to the second aspect of the present invention, the piston of the fluid damper can be simply configured and made robust.

[Brief explanation of the drawing]

FIG. 1 is a vertical cross-sectional view showing one embodiment of the present invention, and FIG.
FIG. ii is a cross-sectional view of FIG. DESCRIPTION OF SYMBOLS 10... Fluid damper, 11... Damper case, 12... Piston, 13A, 13B... Fluid chamber. Work 4...Communication path, 15...Operation axis. 18... Piston body. 19...Ring-shaped electrode, 20...Block-shaped insulator. Agent Patent Attorney Osamu Shiokawa Figure 1

Claims (2)

[Claims] (1) A piston is provided in the damper case, two fluid chambers partitioned by the piston are formed in the damper case, a communication path is provided in the piston to communicate the two fluid chambers, and the operation is fixed to the piston. In a fluid damper whose shaft extends inside and outside the damper case, communicating passages are provided at multiple positions in the circumferential direction and radial direction around the operating axis of the piston, and a pair of inner surfaces facing each other across each communicating passage are provided. A fluid damper characterized in that it is constructed by providing electrodes and filling the two fluid chambers with an electrorheological fluid having a Winslow effect. (2) The piston includes three or more ring-shaped electrodes coaxially around the operating axis of the piston body, and a plurality of block-shaped insulators spaced apart in the circumferential direction of a region sandwiched between adjacent ring-shaped electrodes. 2. The fluid damper according to claim 1, wherein a communication path is defined by adjacent ring-shaped electrodes and adjacent block-shaped insulators.