JPH0417848Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a bladder for an accumulator, and particularly to an accumulator bladder that has excellent gas permeability and durability.

[Prior art and its problems]

Accumulators with conventional bladders are
It is constructed as shown in FIG.

That is, in the accumulator 1 shown in the same figure, the internal space of a substantially spherical shell 2 is connected to a gas chamber 5 and oil by a bladder 4 made of an elastic material such as rubber, which is integrally attached to the shell 2 via a holder 3. It is isolated from room 6.

A hole 7 for gas filling is bored in the neck of the shell 2 on the side of the gas chamber 5, and a gas plug 9 equipped with an O-ring 8 is fitted into the hole 7.

Further, at the bottom of the shell 2 on the side of the oil chamber 6, there is a hole 10 connected to an oil flow path (not shown).
Further, an oil port 11 having a hole 1 is disposed at a center position of the lower surface of the bladder 4 corresponding to the hole 10 of the oil port 11.
A poppet 12 that closes the bladder 4 is integrally provided with the bladder 4.

Appropriate high pressure gas is sealed into the gas chamber 5 through the hole 7, and pressure is introduced into the oil chamber through the hole 10 of the oil port 11.

When a pressure increase such as an abnormal surge pressure occurs in the oil flow path (not shown), the accumulator 1 configured as described above absorbs the abnormal pressure increase and prevents damage to other devices. are doing.

However, the material of the bladder 4 is rubber or soft resin, and therefore the gas chamber 5
Over time, high-pressure gas such as nitrogen gas sealed therein permeated the bladder 4 and leaked into the oil on the oil chamber 6 side, causing the gas pressure in the gas chamber 5 to drop.

Therefore, in order to make the accumulator 1 function normally and absorb abnormal fluid pressure in the oil flow path such as surge pressure, it is necessary to periodically replace the gas or
There is a problem in that it requires recharging, and if this is not done, it will no longer be able to fulfill its role of preventing damage to other devices installed in the oil flow path.

As a result, accumulators installed in automobiles, especially anti-lock brake systems,
The bladder type accumulator 1 is difficult to apply to automobiles due to its small size, high operating temperature, significant drop in gas pressure due to permeation, and difficulty in maintenance such as recharging.

In addition, in order to reduce the permeation of gases such as nitrogen gas and achieve the desired gas permeation resistance, for example, gas permeation resistance suitable for the 10-year service life of automobiles,
When using a metal bellows or a metal film as a sealing packaging material for the rubber or resin bladder 4, there are
Pressure fluctuations at high pressures are large and the bladder deforms greatly, which poses problems such as difficulty in following this deformation.

In view of the above-mentioned problems, the present invention has been developed to improve gas permeability and withstand long-term use without reducing responsiveness to pressure changes compared to conventional products made of a single elastic material such as rubber. The purpose of the present invention is to provide a bladder for an accumulator that has excellent durability.

[Means for solving problems]

In order to solve the above-mentioned problems, the present invention has a configuration in which a bladder body made of an elastic material containing highly conductive particles is plated with a metal thin film on at least one surface thereof.

[Effect]

By adopting the above-mentioned measures, the present invention further improves gas permeation resistance while maintaining durability and withstanding long-term use without reducing responsiveness to pressure changes compared to conventional products. Becomes excellent.

〔Example〕

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

FIG. 1 shows a state in which an accumulator bladder according to the present invention is attached to an accumulator.

That is, the accumulator 1 shown in FIG.
Similar to the conventional one, the interior space of the approximately spherical shell 2 is connected to a gas chamber 5 and an oil chamber 6 by a bladder 4 that is integrally attached to the shell 2 via a holder 3.
It is isolated from.

Here, the bladder 4 according to the present invention is manufactured as follows.

That is, it is generally known as an agent that imparts electrical conductivity to the rubber material that is the material of the bladder body 4b. Carbon black such as acetylene black, oil furnace black, or
Appropriate amounts of fine metal powder, metal flakes, fibers, metal-plated beads, etc. are mixed in, and the rubber material is vulcanized and molded using a mold in the same way as conventional bladders.

With this, the bladder body 4 made of conductive rubber material
b can be done.

Next, a metal thin film 4a is formed on the surface of the vulcanized bladder body 4b by electroplating.

As the metal to be plated, copper, zinc, nickel, tin, cadmium, or a combination thereof is used.

The film thickness is in the range of 2 to 50 μm, preferably 5 to 10 μm.

Then, the bladder 4 made as above
In the case of the accumulator 1 provided with this, a hole 7 for gas filling is bored at the top of the shell 2 on the side of the gas chamber 5, and this hole 7 is similar to the conventional one.
A gas plug 9 equipped with an O-ring 8 is fitted in the shell 2, and a hole 10 connected to an oil flow path (not shown) is provided at the bottom of the shell 2 on the side of the oil chamber 6.
An oil port 11 having an oil port 11 is disposed at a central position of the lower surface of the bladder 4 corresponding to the hole 10 of the oil port 11.
A poppet 12 that closes the bladder 4 is integrally provided with the bladder 4.

Further, appropriate high pressure gas is sealed into the gas chamber 5 through the hole 7, and hydraulic pressure is introduced into the oil chamber 6 through the hole 10 of the oil port 11.

During the above operation, high pressure gas such as nitrogen gas in the gas chamber 5 of the accumulator 1 is transferred to the oil in the oil chamber 6 by the metal thin film 4a that is evenly adhered to the surface of the bladder body 4b made of a conductive rubber material. As a result, if a pressure rise such as abnormal surge pressure occurs in the oil flow path over a long period of time, as described in the conventional example, the abnormal pressure rise will be absorbed. This will continue to prevent damage to other equipment.

The bladder 4 for an accumulator according to the present invention can be electroplated using the conductive bladder body 4b as an electrode, and is inexpensive and suitable for mass production. However, it is not limited to electroplating as described above. A good metal thin film 4a can also be obtained by chemical plating (for example, nickel plating).

[Effect of idea]

This invention has the above configuration, so that
Since a metal thin film is formed by plating on the bladder body made of conductive rubber material, the metal thin film has excellent adhesion to the bladder body, and a uniform metal thin film is obtained, providing excellent gas permeability and durability. A bladder with excellent performance can be obtained, and there is no decrease in the bending durability of this bladder, and there is no deterioration in responsiveness. Moreover, the plating process is simple and can be performed at low cost, and has excellent effects.

[Brief explanation of the drawing]

FIG. 1 is a schematic sectional view showing a state in which an accumulator bladder according to the present invention is attached to an accumulator, and FIG. 2 is a schematic sectional view showing a state in which a conventional accumulator bladder is attached to an accumulator. 1...Akiyumureta, 2...Ciel, 3...
Holder, 4... Bladder, 4a... Metal thin film, 4b
... Bladder body, 5 ... Gas chamber, 6 ... Oil chamber, 7 ... Hole, 8 ... O-ring, 9 ... Gas plug, 10 ... Hole, 11 ... Oil port.

Claims (1)

[Scope of utility model registration request] A bladder for an accumulator, comprising a bladder main body 4b containing highly conductive particles in an elastic material, and a metal thin film 4a applied to at least one surface of the bladder main body 4b by plating.