JPH04171006A - Gas separation device - Google Patents

Abstract

PURPOSE:To avoid securely the storing of gas and control liquid pressure well at all times by making gas existing in a high pressure liquid chamber of a high pressure liquid device diffusible through a selective diffusible film and further making the gas penetrate through a porous backup component and then discharging the gas. CONSTITUTION:At least a part of a high pressure liquid chamber 66 is demarcated by a selective diffusible film 42 composed of a gas diffusible liquid impermeable material and a porous backup component 44 adhered to the back face of said selective diffusible film 44 backing up the selective diffusible film 42 from the back side and allowing the gas to pass through. Also, a high pressure liquid chamber 66 is communicated with a high pressure liquid chamber 14 of a high pressure liquid device 10 by a high pressure piping 30. As a result, gas existing in the high pressure liquid is separated without the necessity of the operation by a worker to get the effect of reducing the working manhour and also avoid securely storing of gas in the high pressure liquid chamber and control the liquid pressure and the like well at all times.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an apparatus for separating gas from high pressure liquid.

BACKGROUND OF THE INVENTION Air bleed valves have traditionally been used to separate gases present in high pressure liquids.

For example, if gas gets mixed into the brake fluid in a vehicle hydraulic brake system, the brake fluid pressure cannot be controlled properly, so as stated in the Automotive Engineering Handbook published by Tosho Publishing on April 25, 1974, In addition, air vent valves were installed in wheel cylinders and the like.

Problem to be Solved by the Invention When the gas present in high-pressure liquid is separated using an air bleed valve, the operator must not operate the air bleed valve. In this case, gas accumulates in the vicinity of the air vent valve, and the contraction and expansion of this gas may impede control of hydraulic pressure.

Note that one of the causes of gas intrusion into high-pressure liquid is that gas permeates through the bladder membrane of a bladder-type accumulator. 252802) is known, but in this case, the cost of the accumulator is high,
- Not suitable for boat fishing use.

With this background in mind, the present invention has been made with the object of providing an apparatus capable of separating gas from high-pressure liquid without requiring operator's operation.

Means for Solving the Problems The gas separation device according to the present invention is characterized by (a) a permselective membrane made of a material that allows gas to pass through but does not allow liquid to pass through, and (b) the back surface of the permselective membrane. The high-pressure liquid chamber is small (
The high-pressure liquid chamber is defined in both parts and has means for communicating the high-pressure liquid chamber with the high-pressure liquid chamber of the high-pressure liquid device.

Function When the high-pressure liquid chamber of the gas separation device according to the present invention is installed in communication with the high-pressure liquid chamber of the high-pressure liquid device, the gas present in the high-pressure liquid of the high-pressure liquid device permeates through the permselective membrane, and furthermore, the porous backup It passes through the member and is discharged to the outside. Since the permselective membrane is made of a material that allows gas to pass through but not liquid, high-pressure liquid will not pass through this membrane and no liquid will leak to the outside.

Effects of the Invention As described above, according to the present invention, the gas present in the high-pressure liquid is separated without requiring any operation by the operator, reducing the number of work steps and reliably preventing the accumulation of gas. This provides the effect that hydraulic pressure control etc. are always performed satisfactorily.

EXAMPLE Hereinafter, an example of the present invention will be described in detail based on the drawings.

In FIGS. 1 and 2, 10 is an accumulator. The main body 11 of the accumulator 10 is formed into a shell shape by combining two bowl-shaped members on the opening side. Inside the main body 11 is a plug membrane 12 (first
The bladder membrane 12 in the figure is also called a diaphragm membrane, but is included in the bladder membrane in a broad sense).
14 is a high-pressure liquid chamber filled with high-pressure liquid, and 16 is a gas chamber filled with high-pressure nitrogen gas. The high-pressure liquid chamber 14 is provided with a high-pressure liquid inlet/outlet 18, and the gas chamber 16 is provided with a check valve 20 for injecting nitrogen gas. In addition, entrance 18
A high pressure pipe 30 is connected to.

A main body 40 of a gas separation device 38 is connected in the middle of the high-pressure pipe 30 . The internal space of the main body 40 is partitioned into two by a permselective membrane 42 that allows gas to pass through but not liquid, and a porous backup member 44 is disposed in close contact with the back surface of the permselective membrane 11142. ing. The outer periphery of the permselective membrane 42 is fixed to a metal retainer 46, and this retainer 46 is connected to the shoulder surface 50 of the main body 40 by a plug 48 with a porous backup member 44 in between.
The permselective membrane 42 and the porous backup member 44 are fixed to the main body 40 by being pressed against them.

The plug 48 has a large tool holding hole 52 formed in the center.
The tool engagement hole 52 is connected to the porous backup member 44 in the main body 40 for rotational operation.
It also serves as a communication hole that connects the space to the atmosphere. Airtightness between the retainer 46 and the main body 40 is maintained by an O-ring 54.

The permselective membrane 42 has a downwardly swollen central portion 56 to increase its surface area, and the porous backup member 44 is also formed with a corresponding protrusion 58 .

Further, the high pressure piping 30 is connected to the main body 40 by pipe joints 60 and 62, whereby the permselective membrane 4
The space on the opposite side to the side where the second porous backup member 44 is disposed is a high-pressure liquid chamber 66 that communicates with the high-pressure liquid passage 64 in the high-pressure pipe 30. The high-pressure liquid passage 64 in the high-pressure pipe 30 is a type of high-pressure liquid chamber, and in this embodiment, the pipe joint 60, 62 and the tool engagement hole 52 are connected to the main body 4.
This constitutes means for communicating the two spaces partitioned by the permselective membrane 42 in the high-pressure liquid device with the atmosphere, respectively.

The bladder membrane 12 of the accumulator 10 is made of butyl rubber, fluororubber, etc. with excellent gas barrier properties, and over a long period of time, nitrogen gas in the gas chamber 16 passes through the bladder membrane 12 and flows into the high-pressure liquid chamber 14. Mixed. On the other hand, the permselective membrane 42 of the gas separation device 38 is made of silicone rubber or the like that allows gas to pass through but not liquid.

Further, these silicone rubber, butadiene rubber, etc. are materials that have higher nitrogen gas permeability than butyl rubber, fluororubber, etc. which are the materials of the bladder membrane 12. For example, the nitrogen permeability of butyl rubber is 2.5 x 10-9c+fl/CT
l1/sec/atm, whereas that of silicone rubber is 28 X 10-'cffl/c111/s
It is about 10 times as much as ec/atm.

Further, the porous backup member 44 must have a large number of communicating holes and must have sufficient strength to support the permselective membrane 42 against the liquid pressure of the high pressure liquid chamber 66. , sintered metal, fired ceramics, etc.

As is clear from FIG. 1, the gas separation device 38 is set above the accumulator 10 and the high pressure pipe 30 with the high pressure liquid chamber 66 at the bottom and the tool retaining hole 52 at the top.

The accumulator 10, high-pressure pipe 30, and gas separation device 38 constitute a hydraulic pressure source of a vehicle hydraulic brake system. Brake fluid pumped by a hydraulic pump (not shown) is stored as high-pressure fluid in the high-pressure fluid chamber 14 of the accumulator 10.
Brake fluid is stored in the accumulator 10 and high pressure piping 3 due to the nitrogen gas pressure in the gas chamber 16.
o, and the brake fluid in the gas separation device 38 is maintained at high pressure and is supplied to the hydraulic booster and wheel cylinders as required.

During this time, the nitrogen gas sealed in the gas chamber 16 of the accumulator 10 passes through the bladder membrane 12 little by little and leaks to the high-pressure liquid chamber 14 side, and gathers to form bubbles. The bubbles pass through the high-pressure liquid passage 64 in the high-pressure pipe 30 and remain in the high-pressure liquid chamber 66 of the gas separation device 38, where they closely adhere to the permselective membrane 42. The permselective membrane 42 is made of a material with high permeability for nitrogen gas, and is designed to have a thickness of 2 areas, etc. so as to be able to discharge the entire amount of nitrogen gas leaking from the bladder membrane 12. The nitrogen gas passes through the permselective membrane 42 and further passes through the porous backup member 44, and flows out from the tool holding hole 52 into the atmosphere. According to the present gas separation device 38, nitrogen gas mixed in brake fluid can be separated and discharged without operator's operation, and the nitrogen gas remains in each part of the vehicle hydraulic brake device. It is possible to avoid this from causing a decrease in brake fluid pressure control accuracy.

The gas separation device according to the present invention is particularly suitable for a high-pressure liquid device including an accumulator in which the liquid is constantly maintained at a high pressure, but it is also suitable for a high-pressure liquid device in which the liquid pressure is increased and decreased. can be used. This is because the gas separation device performs its separation function while the liquid pressure is maintained at a high pressure.

In addition, if the porous backup member is made of a material with fine pores, such as sintered metal or fired ceramics, the permselective membrane will not be damaged even if it is made thin, thereby increasing the gas separation ability. However, if the permselective membrane is relatively thick, it is also possible to use a metal member with a plurality of small holes as a porous backup member.

Furthermore, it is also possible to form a layer of silicone rubber or the like on the surface of a porous sintered metal member having a large number of irregularities on the surface, and to integrally configure the permselective membrane and the porous backup member. It is also possible that part or all of the main body of the gas separation device is made of a porous sintered metal member or the like, and a film of silicone rubber or the like is formed on the inner surface of the main body so that the main body also serves as a porous backup member.

In addition, the present invention can be implemented with various modifications and improvements based on the knowledge of those skilled in the art without departing from the scope of the claims.

[Brief explanation of drawings]

FIG. 1 is a front cross-sectional view of a high-pressure liquid device equipped with a gas separation device according to an embodiment of the present invention. FIG. 2 is a plan view of the gas separation device. 38: Gas separation device 40: Gas separation device main body 42: Permselective membrane 44: Porous backup member 46: Retainer 48 Nib lug 52: Tool engagement hole 60, 62: Pipe joint 66: High pressure liquid chamber

Claims (1)

[Claims] A permselective membrane made of a material that allows gas to pass through but does not allow liquid to permeate; and a permselective membrane that is in close contact with the back surface of the permselective membrane to support the selectively permselective membrane from behind and allow gas to pass through. A gas separation device characterized in that at least a portion of the high pressure liquid chamber is defined by a porous backup member, and means for communicating the high pressure liquid chamber with a high pressure liquid chamber of a high pressure liquid device.