JPH0488233A - Shock absorber - Google Patents

Abstract

PURPOSE:To maintain the viscosity increasing effect, etc., for a long period and improve the durability of the electric viscous fluid by charging the inside of a case with the electric viscous fluid and allowing the voltage applied between electrodes to be controlled. CONSTITUTION:When a voltage is applied between electrode plates 20, an electric field is formed which crosses at right angle with the flow of the electric viscous fluid which directs to a fluid chamber 9b from a fluid chamber 9a through a communication passage 10a, through hole 8a, and a communication passage 10b or the flow in the counter direction, and the viscosity of the electric viscous fluid nipped between the electrode plates 2 increases. Accordingly, the viscosity of the fluid which passes through the through hole 8a of a piston 8 is controlled, and the viscous resistance of the fluid is adjusted. When the piston 8 lowers, a portion of the electric viscous fluid in the fluid chamber 9b circulates in the fluid chamber 9a in the upper part of a case 7 through a circulation pipe 16 and a check valve 15, and the electric viscous fluid is agitated, and the sinking of the solid particles is reduced, and even if the solid particles precipitate, the solid particles are dispersed, and the characteristic of the electric viscous ffuid such as viscosity increasing effect can be maintained.

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention is widely used in industrial machinery, transportation machinery such as vehicles, and other types of equipment, and is used to damp vibrations in vibration systems or to act on drive systems. This invention relates to a mechanical shock absorber for making force variable.

[Prior Art] Conventionally, a working fluid such as oil or air is used as a shock absorber, a piston is provided in a damper case, two fluid chambers are formed in the damper case by the piston, and two fluid chambers are formed in the piston. Provide an orifice that communicates with
It is known that an operating shaft fixed to a piston extends inside and outside a damper case, and a vibrating body is connected to this operating shaft.

[Problems to be Solved by the Invention] However, the vibration damping characteristics of the conventional shock absorber described above are fixed depending on the shape of the orifice and the characteristics of the working fluid.

Therefore, when the above-mentioned Shikaku absorber is used in a vibration system different from its original design conditions, optimum vibration damping characteristics cannot be obtained. Further, when the shock absorber is used in a vibration system whose vibration state changes over time, the vibration cannot be effectively damped.

In order to solve the above problem, the present applicant filled a damper case with an electrorheological fluid, arranged an electrode in an orifice that communicates between two fluid chambers, and applied a voltage between the electrodes to prevent the electrorheological fluid from flowing. We have proposed a system that can control the viscosity of the engine and make the damping force of the engine variable. however,
The electrorheological fluid filled in the shock absorber is only slightly agitated by the up and down movement of the piston.
Solid particles in the electrorheological fluid precipitate due to long-term use.
There are problems such as sedimentation and deterioration of only the fluid near the electrode, a decrease in the coupling term of the electrorheological fluid, and durability.

The present invention solves the above-mentioned problems, and aims to provide a syrup absorber that can constantly circulate and stir electrorheological fluid and improve the durability of electrorheological fluid. shall be.

[Means for solving the problem] For this purpose, the shock absorber 6 of the present invention has a case 7.
a piston 8 provided therein, and two fluid chambers 9 as 9 b formed in the case by the piston 8.
, a through hole 8a provided in the piston 8, and an electrode plate 2 arranged in parallel with an interval in the through hole 8a.
0, and a circulation pipe 16 connecting the bottom and top of the case 7.
It consists of a check valve 15 provided in the middle of the circulation pipe, and an operating shaft 11 connected to the piston 8, which fills the case 7 with electrorheological fluid and controls the voltage applied between the electrodes. It is characterized by being controllable.

Note that the numbers added to the above configurations are for comparison with the drawings to facilitate understanding, and the configurations of the present invention are not limited thereby.

[Operation] In the present invention, when a voltage is applied between the electrode plates 20,
The communication path 10a1 forms an electric field perpendicular to the flow of electrorheological fluid from the fluid chamber 9a to the fluid chamber 9b through the through hole 8a and the communication path 10b, or the flow of the electrorheological fluid in the opposite direction, and the electric field is generated between the electrode plates 20. This increases the viscosity of the electrorheological fluid sandwiched between the two. Therefore, the viscosity of the fluid passing through the through hole 8a of the piston 8 is controlled, and as a result, the viscous resistance of the fluid in the through hole 8a is adjusted. Then, when the piston 8 descends,
A part of the electrorheological fluid in the fluid chamber 9b circulates through the circulation pipe 16 and the check valve 15 toward the fluid chamber 9a in the upper part of the case 7, so that the electrorheological fluid is stirred and solid particles are There is little precipitation, and even if precipitation occurs, the solid particles are dispersed by circulation, and the properties of the electrorheological fluid, such as the thickening effect, are maintained.

[Example] Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a cross-sectional view showing one embodiment of the shock absorber of the present invention, and FIG. 2 is a cross-sectional view taken along the line ■-■ in FIG.

The lock absorber 6 has a piston 8 inside the case 7.
The piston 8 is slidably fitted into the case 7.
Two fluid chambers 9at9b are formed which are partitioned by. A through hole 8a having a rectangular cross section is formed in the axial direction in the piston 8, and a large number of electrode plates 20 (
(Fig. 2) are arranged in parallel at intervals, and the upper and lower piston covers 8 bz 8 c are attached to the piston 8 with bolts 2.
It is fixed at 1. The upper and lower piston covers 8b1
8C is provided with a communication passage 10a110b, and the two fluid chambers 9a19b are communicated via the communication passage 10a1, the through hole 8a, and the communication passage 10b. Further, an operating shaft 11 is connected and fixed to the upper piston cover. In addition, 12
13 is a piston ring, and 13 is a seal member.

An inclined surface 7a is formed at the bottom of the case 7, and the bottom and top of the case 7 are connected by a circulation pipe 16 including a check valve 15. The case 7 is filled with an electrorheological fluid that produces the Winslow effect. Further, a large number of electrode plates 20 are connected to a voltage source through the operating shaft 11. Regarding the connection of this voltage source, the cylinder wall may be used instead of the actuating shaft 11.

The electrorheological fluid, which is essential to the configuration of the present invention, will be explained. The Winslow effect possessed by electrorheological fluids is disclosed in U.S. Patent No. 2,417,850, and is created by suspending solid particles (dispersoids) in an electrically insulating liquid (dispersion medium) between two electrodes. When a so-called electrorheological fluid is filled and a voltage is applied between both 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 of very good responsiveness.

The electrically insulating liquid used as a dispersion medium for the above-mentioned electrorheological fluid may be any electrically insulating liquid and is not subject to any particular restrictions, but examples include mineral oil and synthetic oil. Examples include naphthenic mineral oil, paraffinic mineral oil, polyalphaolefin, polyalkylene glycol, silicone 1J cone, diester, polyol ester, phosphoric acid ester, silicon compound, fluorine compound, polyphenyl ether, alkylbenzene, and the like.

The viscosity range of these electrically insulating liquids is 5 at 40°C.
~300CP is preferred.

In addition, as the porous solid particles used as the dispersoid, conventional ones are used and are not subject to any particular restrictions, but for example,
Examples include silica gel, hydrous resin, diatomaceous earth, alumina, silica-alumina, zeolite ion exchange resin, and cellulose. These porous solid particles typically have a particle size of 10
Those with a diameter of nm to 200 μm are used in a proportion of 0.1 to 50 wt%.

Additionally, water, polyhydric alcohol, acid, salt, or base is added to enhance the polarization promoting effect. In particular, it is preferable to use the porous solid particles, which are dispersoids, in a manner that facilitates dielectric polarization. The amount of water or polyhydric alcohol used is usually 1 to 20 wt% based on the porous solid particles. Further, the amount of acid, salt, and base to be used is usually 0.01 to 5 wt% based on the porous solid particles.

Further, a dispersant is used to uniformly and stably disperse the porous solid particles in the dispersion medium. for example,
Sulfonates, phenates, phosphonates, succinimides, amines, esters, nonionic dispersants, etc. More specifically, magnesium sulfonate, calcium sulfonate, calcium phenate, calcium phosphonate, polybutenyl succinate. These include acid imides, sorbitan monooleate, and sorbitan sesquiolate. These are usually used in a proportion of 0.1 to 10 wt%. However, the dispersant may not be used if the solid particles have good dispersibility.

Next, the operation of the present invention having the above configuration will be explained.

When a voltage is applied between the electrode plates 20, an electric field perpendicular to the flow of the electrorheological fluid from the fluid chamber 9a to the fluid chamber 9b through the communication path 10a1, the through hole 8a and the communication path 10b or the flow of the electrorheological fluid in the opposite direction is generated. (This increases the viscosity of the electrorheological fluid sandwiched between the electrode plates 20. Therefore, the viscosity of the fluid passing through the through hole 8a of the piston 8 is controlled, and as a result, the viscosity of the fluid in the through hole increases. The viscous resistance of is adjusted.

Therefore, the voltage applied between the electrode plates 20 is
By appropriately controlling the weight, speed, direction of movement, etc. of the gear absorber 1, the vibration damping characteristics of the gear absorber 6 can be adjusted very easily.

Furthermore, in the present invention, when the piston 8 descends,
A part of the electrorheological fluid in the fluid chamber 9b circulates through the circulation pipe 18 and the check valve 15 toward the fluid chamber 9a in the upper part of the case 7, so that the electrorheological fluid is stirred and solid particles are No precipitation or precipitation. Further, since the inclined surface portion 7a is formed at the lower part of the case 7, even if solid particles in the electrorheological fluid settle, they flow in the direction of the circulation pipe 16 and are stirred. Note that when the piston 8 moves up, the electrorheological fluid is blocked by the check valve 15 and does not circulate.

[Effects of the Invention] As described above, according to the present invention, a piston provided in a case, two fluid chambers formed in the case by the piston, and a through hole provided in the piston, electrode plates arranged in parallel at intervals within the through hole; a circulation pipe connecting the bottom and top of the case 7;
It consists of a check valve provided in the middle of the circulation pipe and an operating shaft connected to the piston, and is configured to fill the case with electrorheological fluid and to control the voltage applied between the electrodes. Therefore, by lowering the piston, the electrorheological fluid can be constantly circulated and stirred, and the long-term maintenance and durability of the viscosity increasing effect of the electrorheological fluid can be improved.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing one embodiment of the fluid damper of the present invention;
FIG. 2 is a cross-sectional view taken along line n-■m in FIG. 1 6...Fluid tamper, 7...Case, 8...Piston, 8a...
Through hole, 9a19b...fluid chamber, 11...operating shaft,
15...Check valve, 16...Circulation pipe, 20...
electrode plate. Applicant: Tonen Co., Ltd. Patent Attorney Hiroki Shirai (7 others) θ Keno 1
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Claims (1)

[Claims] (1) A piston provided in a case, two fluid chambers formed in the case by the piston, a through hole provided in the piston, and arranged in parallel with an interval within the through hole. It consists of an electrode plate, a circulation pipe connecting the bottom and top of the case 7, a check valve provided in the middle of the circulation pipe, and an actuation shaft connected to the piston, and the case is filled with electrorheological fluid. A shock absorber characterized in that the voltage applied between the electrodes can be controlled.