JP2006046635A - Pressure pulsation absorber and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pressure pulsation absorber and its manufacturing method capable of exercising a pulsation absorbing effect over a long period of time having a wide range of application by a compact and simple structure, and easily manufacturable. <P>SOLUTION: This pressure pulsation absorber mounted in a pressure circuit for absorbing pulsation is composed of a foamed body composed of an elastic body, and a resin film wrapping the foamed body and composed of an ethylene-vinyl alcohol copolymer. This manufacturing method of the pressure pulsation absorber mounted in the pressure circuit for absorbing the pulsation comprises applying a solution prepared by dissolving the ethylene-vinyl alcohol copolymer into a solvent to the foamed body composed of the elastic body, and then removing the solvent to form a resin film wrapping the foamed body and composed of the ethylene-vinyl alcohol copolymer. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a pulsation absorber used to reduce pulsation of pressure fluid in a pressure line, and more specifically, a pressure pulsation absorber that efficiently absorbs pressure and flow pulsation of pressure fluid flowing in a pipe. And a manufacturing method thereof.

Conventionally, as a means for suppressing pulsation of pressure fluid, a bladder or diaphragm made of synthetic rubber is used for an accumulator to which a bladder or a diaphragm is attached, and a piston type accumulator type is used to move the piston and a spring. The bellows is used in the lator, and the pressure is suppressed (absorbed) by changing the volume of the sealed gas or the spring in response to the pressure fluctuation in the fluid (for example, Patent Document 1).
Japanese Patent Laid-Open No. 10-159803 (Claims, Embodiment of the Invention, FIG. 1)

However, such an accumulator has the biggest drawback that its structure is complicated and expensive. In addition, there are various drawbacks that cannot be generalized, such as the complexity of maintenance associated with high-pressure nitrogen gas, as well as limited applications.
In order to eliminate such drawbacks, a simple structure that reduces the pulsation of fluid pressure by installing foam rubber in the pressure fluid flow path was also considered. However, if the pulsation is repeated in the pressure fluid, the foam rubber The air in the air bubbles leaks into the liquid, or the liquid penetrates through the rubber and penetrates into the foamed rubber, so that the effect of preventing pulsation is reduced at an early stage, so that it has not spread widely.

Accordingly, the present invention provides a pressure pulsation-absorbing foam that can exhibit a pulsation-absorbing effect over a long period of time, can be made to have a small and simple structure, and can be easily manufactured, and a method for producing the same. For the purpose.

  In order to solve the above-mentioned problems, the present invention provides a pressure pulsation absorber for absorbing a pulsation disposed in a pressure circuit, the foam comprising an elastic body, and The pressure pulsation absorber is characterized by being formed by a resin film enclosing the foam.

The invention according to claim 2 is a pressure pulsation absorber for absorbing pulsation disposed in a pressure circuit, comprising a foam made of an elastic body and an ethylene-vinyl alcohol copolymer enclosing the foam. There is provided a pressure pulsation absorber characterized by being formed of a resin film.

The invention according to claim 3 provides a pressure pulsation absorber, wherein the ethylene content of the ethylene-vinyl alcohol copolymer according to claim 2 is 10 mol% to 70 mol%.

  The invention according to claim 4 provides a pressure pulsation absorber, wherein the thickness of the resin film made of the ethylene-vinyl alcohol copolymer according to claim 2 is 1-1000 microns.

  The invention according to claim 5 is a method for producing a pressure pulsation absorber for absorbing pulsation disposed in a pressure circuit, and a solution obtained by dissolving an ethylene-vinyl alcohol copolymer in a solvent is made of an elastic body. Provided is a method for producing a pressure pulsation absorber, wherein a resin film made of an ethylene-vinyl alcohol copolymer enclosing the foam is formed by removing the solvent after being applied to the foam.

The invention according to claim 6 provides a method for producing a pressure pulsation absorber, wherein the coating method according to claim 5 is a spray method.

  The invention according to claim 7 provides a method for producing a pressure pulsation absorber, wherein the coating method according to claim 5 is an immersion method.

  The invention according to claim 8 provides a method for producing a pressure pulsation absorber, wherein the solvent according to claim 5 is a mixture of alcohol and water.

The invention according to claim 9 is a method of manufacturing a pressure pulsation absorber for absorbing pulsation disposed in a pressure circuit, and covers a foam made of an elastic body by combining a single or a plurality of them in advance. A film-like body made of a resin is formed into a possible shape, the film-like body is placed in a state of covering the foam, and a contact portion between the film-like bodies made of resin is joined and sealed. A method for producing a pressure pulsation absorber is provided.

The invention according to claim 10 is a method of manufacturing a pressure pulsation absorber for absorbing pulsation arranged in a pressure circuit, and covers a foam made of an elastic body by combining a single or a plurality in advance. A film-like body made of an ethylene-vinyl alcohol copolymer is formed into a possible shape, and the film-like body is placed in a state of covering the foam, and the contact portions of the film-like bodies made of resin are joined together. And a method of manufacturing a pressure pulsation absorber.

In the pressure pulsation absorber according to claim 1, since the foam is formed of an elastic body and a resin film enclosing the foam, the resin film is excellent in flexibility and permeation resistance to gas and liquid. For this reason, the pulsation absorbing effect can be exhibited over a long period of time, and the pressure pulsation absorber can be manufactured with a small, simple structure and a wide range of application, and can be easily manufactured.

Since the pressure pulsation absorber of claim 2 is formed of a foam made of an elastic body and a resin film made of an ethylene-vinyl alcohol copolymer enclosing the foam, the same effect as in claim 1 is obtained. In addition, the resin film is further excellent in flexibility and excellent in permeation resistance to gases and liquids, and becomes a pressure pulsation absorber capable of exhibiting a pulsation absorption effect over a long period of time.

In the pressure pulsation absorber according to claim 3, since the ethylene content of the ethylene-vinyl alcohol copolymer according to claim 2 is 10 mol% to 70 mol%, the flexibility of the resin film and the resistance to gas and liquid are obtained. The balance of permeability can be made good, so that the same effect as in claim 2 can be obtained, and the pulsation absorption effect can be further exhibited over a long period of time, with a small and simple structure and wide application range In addition, the pressure pulsation absorber can be easily manufactured.

In the pressure pulsation absorber according to claim 4, since the thickness of the resin film made of the ethylene-vinyl alcohol copolymer according to claim 2 is set to 1 to 1000 microns, the flexibility of the resin film and the permeation resistance to gas and liquid are obtained. Therefore, the effect similar to that of claim 2 can be obtained, and the pulsation absorbing effect can be further exhibited over a long period of time. The compact and simple structure has a wide application range. In addition, the pressure pulsation absorber can be easily manufactured.

In the manufacturing method of the pressure pulsation absorber of Claim 5, after apply | coating the solution which melt | dissolved the ethylene-vinyl alcohol copolymer in the solvent to the foam which consists of an elastic body, this solvent is removed by removing this solvent. A resin film made of an ethylene-vinyl alcohol copolymer that encloses the pressure pulsation is formed, so that the pulsation absorbing effect can be demonstrated over a long period of time, and it is easy to manufacture a pressure pulsation absorber with a small and simple structure and a wide range of applications. It becomes the manufacturing method of the pressure pulsation absorber which can be made.

In the method for producing a pressure pulsation absorber according to claim 6, since the coating method according to claim 5 is a spray method, the same effects as those of claim 5 can be obtained, and the pressure pulsation absorption can be further facilitated. It becomes a manufacturing method of a body.

  In the method for producing a pressure pulsation absorber according to claim 7, since the coating method according to claim 5 is an immersion method, the same effect as in claim 5 can be obtained, and the pressure pulsation absorption can be further facilitated. It becomes a manufacturing method of a body.

  In the method for producing a pressure pulsation absorber according to claim 8, since the solvent according to claim 5 is a mixed solution of alcohol and water, the same effect as in claim 5 can be obtained, and the production is further facilitated. It becomes a manufacturing method of a pressure pulsation absorber.

In the method for producing a pressure pulsation absorber according to claim 9, a film-like body made of a resin is formed into a shape capable of covering a foamed body made of an elastic body by combining a single or a plurality in advance. Since the body is arranged so as to cover the foam, and the contact portions between the film-like bodies made of resin are joined and sealed, the film-like body made of resin is individually molded in advance. A film-like body having good thickness uniformity and good film quality can be easily formed, and the resin film has excellent flexibility and permeation resistance to gases and liquids. For this reason, the pulsation absorbing effect can be exhibited over a long period of time, and the manufacturing method of the pressure pulsation absorber can be made to have a small and simple structure and a wide range of application, and can be easily manufactured.

In the method for producing a pressure pulsation absorber according to claim 10, a film-like body made of an ethylene-vinyl alcohol copolymer is formed into a shape capable of covering a foam made of an elastic body by combining a single or a plurality of them in advance. Since the film-shaped body is molded and disposed so as to cover the foam, and the contact portions between the film-shaped bodies made of resin are joined and sealed, the same effect as in claim 9 can be obtained. In addition, the resin film is further excellent in flexibility and excellent in permeation resistance to gases and liquids, and a method for producing a pressure pulsation absorber capable of exhibiting a pulsation absorption effect over a long period of time.

  As the best mode of the pressure pulsation absorber and the manufacturing method thereof according to the present invention, a pressure pulsation absorber comprising a foam made of an elastic body and a resin film made of an ethylene-vinyl alcohol copolymer enclosing the foam, and The manufacturing method will be described below.

  As an elastic body used as a foam made of an elastic body constituting the pressure pulsation absorber of one embodiment of the present invention, for example, a material such as rubber, resin, or thermoplastic elastomer is used, from the viewpoint of pulsation absorption characteristics. Preferably, rubber and thermoplastic elastomer having excellent elastic properties are used, and it is possible to form a foam made of an elastic body by foaming this elastic body.

In addition, the foaming method of this invention is not specifically limited, For example, you may use the chemical foaming method made to foam by utilizing the gas component generated by a chemical reaction. Specifically, it is only necessary to mix the foaming agent with the elastic body and then foam the elastic body. Examples of the foaming agent include organic foams such as azodigalbonamide, azobisisobutyronitrile, and dinitrosopentamethylenetetramine. Inorganic foaming agents such as agents, carbonates, bicarbonates are often used.
As another foaming method, a physical foaming method in which foaming is performed by using a gas generated by utilizing a phase change of a substance may be used. Specifically, similar to the chemical foaming method, the foaming agent may be mixed with the elastic body and then the elastic body may be foamed. Examples of the foaming agent include low molecular weight hydrocarbons such as ethylene, propane, butane, and pentane. As the resin constituting the shell, for example, polyethylene, polypropylene, styrene resin, acrylic resin, polyethylene terephthalate, fluorine resin, polyacrylonitrile, polymethyl acrylate, polyvinyl alcohol, an ethylene-vinyl alcohol copolymer are used. Inflatable microcapsules are often used.
Furthermore, as another foaming method, a mechanical foaming method in which a foam is formed by forcibly stirring and mixing gas from the outside and then curing may be used. Specifically, the gas component may be, for example, a low molecular weight hydrocarbon, or a gas component such as oxygen, nitrogen, or air.

The resin film that encloses the foam constituting the pressure pulsation absorber of one embodiment of the present invention uses an ethylene-vinyl alcohol copolymer that is excellent in flexibility and excellent in permeation resistance to gases and liquids. It can be synthesized by copolymerization of ethylene and vinyl acetate followed by a saponification reaction.

Regarding the ethylene content of the ethylene-vinyl alcohol copolymer constituting the pressure pulsation absorber of one embodiment of the present invention, if the content is too large, the permeation resistance to gas and liquid is lacking, and if it is too small, the ethylene content is flexible. Lack of sex. Therefore, the content is preferably 10 mol% to 70 mol%, and the best balance between flexibility and permeation resistance to gas and liquid is that the content is 30 mol% to 50 mol%. This is the case. Furthermore, regarding the thickness of the resin film of the ethylene-vinyl alcohol copolymer constituting the pressure pulsation absorber of one embodiment of the present invention, if the thickness is too thin, the resin film lacks strength, and if it is too thick, the resin film The film lacks flexibility. Therefore, the thickness is preferably 1 to 1000 microns, and the balance between the strength and flexibility of the resin film is best when the thickness is 2 to 100 microns.

As a method for forming a resin film of an ethylene-vinyl alcohol copolymer, which is a method for producing a pressure pulsation absorber according to an embodiment of the present invention, ethylene-vinyl alcohol obtained by dissolving an elastic body in a foamed foam is dissolved in a solvent. A method of applying a copolymer is used. The ethylene-vinyl alcohol copolymer can be dissolved in a solvent. For example, water or alcohol such as methyl alcohol, isopropyl alcohol, or butyl alcohol is used as the solvent, and alcohol and water are used. A mixed liquid may be used. Furthermore, you may use the mixed solvent which prepared the other solvent in arbitrary ratios. Next, as the dissolution method, for example, the ethylene-vinyl alcohol copolymer can be dissolved in the liquid by stirring and mixing, and the liquid may be dissolved while heating arbitrarily. It may be dissolved while refluxing.

Although it forms by apply | coating the melted ethylene-polyvinyl alcohol solution to the foam which consists of an elastic body in this way, it does not specifically limit as the application | coating method.
For example, the resin film of the ethylene-polyvinyl alcohol copolymer may be formed by spraying an ethylene-vinyl alcohol copolymer solution onto the foam using an air gun, and then removing the solvent. May be immersed in an ethylene-polyvinyl alcohol copolymer solution, and then the solvent may be removed to form an ethylene-polyvinyl alcohol copolymer resin film.
Further, the method for removing the solvent of the ethylene-polyvinyl alcohol copolymer solution coated in this way is not particularly limited. For example, the solvent is removed by leaving at room temperature, the solvent is removed by leaving in a heat oven, and the vacuum is removed. For example, the solvent can be volatilized by leaving it.

Further, as another manufacturing method, the following method may be used, which will be described with reference to FIGS. FIG. 1 is a cross-sectional view showing a state of molding of a film-like body of an embodiment of another method for producing a pressure pulsation absorber of the present invention, and FIG. 2 is a diagram of one method for producing another pressure pulsation absorber of the present invention. FIG. 3 is a cross-sectional view showing a foam covering process using the film-like body of the embodiment, FIG. 3 is a top view of the pressure pulsation absorber according to one embodiment of the method for producing another pressure pulsation absorber of the present invention, and FIG. Sectional drawing of the joining process by the 1st modification of one Example of the manufacturing method of the other pressure pulsation absorber of this invention, FIG. 5 is 2nd of one Example of the manufacturing method of the other pressure pulsation absorber of this invention. FIG. 6 is a cross-sectional view of the pressure pulsation absorber before and after joining according to a modification, and FIG. FIG. 7 is a cross-sectional view and a top view, and FIG. 7 is a pressure pulsation according to fourth and fifth modifications of an embodiment of another method of manufacturing a pressure pulsation absorber. It is a cross-sectional view of the absorbent body.
In FIG. 2 which is a cross-sectional view showing a foam outer covering process using a film-like body of an embodiment of another method for producing a pressure pulsation absorber of the present invention, FIG. 2 (A) shows the foam and the film-like body. 2B is a cross-sectional view showing a state in which the foam and the film-like body are placed on the outer surface, and FIG. 2C is a bonding process for the film-like body. FIG. 2D is a cross-sectional view showing a state after the completion of bonding. In FIG. 5 which is a cross-sectional view of the pressure pulsation absorber according to the second modification of the embodiment of the method for producing another pressure pulsation absorber of the present invention before and after joining, FIG. 5 (A) is a foam and a film-like body. FIG. 5B is a cross-sectional view showing a state after the completion of joining. FIG. 6A is a cross-sectional view and a top view showing the foam covering process of the film-like body according to the third modification of the embodiment of the method for producing another pressure pulsation absorber of the present invention. ) Is a cross-sectional view showing a state before the foam and the film-like body are placed on the outside, FIG. 6 (B) is a cross-sectional view showing a state after the completion of joining, and FIG. FIG. 6D is a top view after the film-like body covering the hollow portion is deleted. In FIG. 7 which is a cross-sectional view of the pressure pulsation absorber according to the fourth and fifth modifications of one embodiment of the method for producing another pressure pulsation absorber, FIG. 7 (A) is the fourth modification, and FIG. ) Shows a fifth modification.

By the foaming method described above, the elastic body is foamed to form a foam having a desired shape. Next, a film-like body 11 made of a resin is formed as shown in FIG. 1 into a shape capable of covering the foam by combining a single or a plurality. FIG. 1 shows an example in which the foam 12 can be covered by combining the two film bodies 11 of the upper film body 11a and the lower film body 11b. The film body 11 (upper film body 11a, lower film body 11b) is a mold cavity formed by combining the upper mold 14a for molding a film body and the lower mold 14b for molding a film body. It shape | molds by the injection molding which inject | pours resin into the part 14c. In the present embodiment, the upper film body 11a and the lower film body 11b have the same shape symmetrical in the vertical direction, and the same film-forming mold 14 (the upper mold 14a for film-forming molding) The upper film body 11a and the lower film body 11b are formed by using a lower mold 14b) for forming a film body.

The foamed body 12 and the film-like body 11 (the upper film-like body 11a and the lower-side film-like body 11b) formed of the elastic body thus formed are combined into the film-like body 11 ( The upper film body 11a and the lower film body 11b) are arranged as shown in FIG.

Next, the foam 12 and the film-like body 11 (the upper film-like body 11a and the lower film-like body 11b) in a state of being combined and arranged as shown in FIG. In the joining mold 15 (upper joining mold 15a, lower joining mold 15b) that has been heated to the melting temperature of the resinous film 11 (upper film 11a, lower film 11b) in advance. The film-like body contact part 11c (upper film-like body contact part 11c1, lower film-like body contact part 11c2) and film-like body 11 (upper film-like body 11a, lower film-like form) The contact portion between the body 11b) and the foam 12 is welded and joined. Thereafter, the molded pressure pulsation absorber 13 is taken out from the joining mold 15 (joining upper mold 15a, joining lower mold 15b). In this welding step, the lower film body 11b, the foam body 12, and the upper mold film body 11a are arranged in this order in the lower mold 15b for bonding. In 11b), the foam 12 is placed so as to cover it, and the joining mold 15 (the joining upper mold 15a and the joining lower mold 15b) is heated in a state of being clamped by the joining upper mold 15a. And may be welded. As described above, the pressure pulsation absorber 13 as shown in FIG. 2 (D) and FIG. 3 can be manufactured.
In addition, the bonding process of the film-like body 11 (upper film-like body 11a, lower film-like body 11b) is performed as shown in FIG. It is good also as the upper metal mold | die 15a for joining which presses only the contact part 11c2) of a shape-like body.

Further, the upper film body 11a and the lower film body 11b may be asymmetrical, and the upper film body 11a as shown in FIGS. 5A to 5B is formed into a sheet-like flat shape. Furthermore, it is good also as a cylindrical thing which has the hollow part 13a as shown to FIG. 6 (A)-(D), and after joining the film-like body 1 like FIG. 6 (B), FIG. The part of the upper membrane 1a provided in the hollow part 13a may be removed and molded as in C).

In the embodiment shown above, the contact portion 11c of the membrane-like body to be joined (the contact portion 11c1 of the upper membrane-like body and the contact portion 11c2 of the lower membrane-like body) is compared with the shape of the foam 12 made of an elastic body. Although it is formed so as to protrude, this part may be removed by subsequent processing so that it can be easily inserted into the desired place during installation, and this part can be used as a fixed part after installation Further processing may be performed.

Furthermore, in the said Example, the contact part 11c (the contact part 11c1 of an upper film-like body, and the contact part 11c2 of a lower film-like body) to join the film-like body with respect to the shape of the foam 12 which consists of an elastic body Although formed so as to protrude, as shown in FIGS. 7A and 7B, the contact portion 11c of the film-like body (the contact portion 11c1 of the upper film-like body, the contact portion 11c2 of the lower film-like body) ) May be formed along the shape of the foam 12 made of an elastic material. FIG. 7A, which is a fourth modification, is an example in which the contact portion 11 c of the film-like body is formed along the vertical side surface of the foam 12. FIG. 7B, which is a fifth modification, is an example in which the contact portion 11c of the film-like body is formed along the horizontal lower surface of the foam 12.
Since there is no protrusion in the state after completion of joining, these can be made good in insertion property at the time of attachment without subsequent processing.

Further, as another embodiment according to the manufacturing method of the present invention, an example in which the foam 12 is covered with the film-like body 1 made of a single resin will be described with reference to FIG. FIG. 8 is a cross-sectional view showing the process of covering the foam 12 with the film-like body 11 according to another embodiment of the method for producing a pressure pulsation absorber of the present invention.
The shape of the film-like body 11 to be molded in advance is formed into a shape capable of covering the foam 12 by bending as shown in FIG. As shown in FIG. 8B, the lower part 11e of the film-like body is put in the lower die 15b for bonding, the foam body 12 is disposed therein, and the upper side of the film-like body is covered so as to cover the foam body 12 The part 11d is bent, and in this state, the upper part 15a for joining is clamped to join the contact part 11c of the film-like body.

The pressure pulsation absorber made of the elastic body of the present invention and the resin film enclosing it formed as described above is arranged in the pressure circuit to allow the pressure fluid to flow, The pressure fluid pulsation and surge pressure generated by the control device are extremely effectively suppressed. The pressure fluid is not particularly limited, and examples thereof include engine oil, ATF oil, hydraulic oil, fuel oil, brake oil, refrigerator oil, long life coolant, and water.
That is, this pressure pulsation absorber holds gas inside, changes its volume each time by fluid pressure, absorbs the pressure change, and pumps fluid without pulsation, pressure change, etc. to other devices. Will be able to.

Next, the evaluation results of the pulsation absorption characteristics of the pressure pulsation absorber according to one embodiment of the present invention will be described below.
As shown in FIG. 9, the pressure pulsation absorbers of Examples 1 and 2 which are one embodiment of the present invention shown in Table 1 and the pressure pulsation absorbers of Comparative Examples 1 and 2 which are conventional forms are shown in FIG. The pulsation absorption characteristics were evaluated with a testing machine.
As the evaluation results, the amplitude after 168 hours endurance as the pulsation absorption characteristic is shown in the lower part of Table 1, and the waveform chart of the pulsation absorption characteristic measured without placing the pressure pulsation absorber in the path is shown in FIG. FIG. 12 is a waveform diagram of the pulsation absorption characteristics after 168 hours have elapsed after arranging the pressure pulsation absorber of Example 1 which is an embodiment of the present invention, and FIG. The measurement is started with the pressure pulsation-absorbing foaming material of No. 1, and the waveform diagram of the pulsation absorption characteristics after 168 hours have elapsed is shown.
In both Examples 1 and 2, the amplitude is smaller than in Comparative Examples 1 and 2, and the pulsation absorption characteristics are excellent.

As described above in detail, according to the present invention, a pressure pulsation absorber that can exhibit a pulsation absorbing effect over a long period of time, can be made to have a small, simple structure, and a wide range of application, and can be easily manufactured, and a manufacturing method thereof Can be provided.

Sectional drawing which showed the shaping | molding state of the film-like body of one Example of the manufacturing method of the other pressure pulsation absorber of this invention Sectional drawing which showed the outer covering process of the foam by the film-like body of one Example of the manufacturing method of the other pressure pulsation absorber of this invention The top view of the pressure pulsation absorber by one Example of the manufacturing method of the other pressure pulsation absorber of this invention Sectional drawing of the joining process by the 1st modification of one Example of the manufacturing method of the other pressure pulsation absorber of this invention. Sectional drawing before and behind joining of the pressure pulsation absorber by the 2nd modification of one Example of the manufacturing method of the other pressure pulsation absorber of this invention Sectional drawing and top view which showed the outer covering process of the foam by the film-like body by the 3rd modification of one Example of the manufacturing method of the other pressure pulsation absorber of this invention Sectional drawing of the pressure pulsation absorber by the 4th and 5th modification of one Example of the manufacturing method of the other pressure pulsation absorber of this invention Sectional drawing which showed the covering process of the foam 12 by the film-like body 11 by the other Example by the manufacturing method of the other pressure pulsation absorber of this invention. The block diagram which showed the evaluation apparatus of the pressure pulsation absorber of this invention Waveform diagram of pulsation absorption characteristics measured without placing a pressure pulsation absorber in the path Waveform diagram of pulsation absorption characteristics after 168 hours have elapsed after placing the pressure pulsation absorber of Example 1 which is an embodiment of the present invention in the path and starting measurement. Waveform diagram of pulsation absorption characteristics after 168 hours have elapsed after the pressure pulsation absorber of Comparative Example 1 which is a conventional form is placed in the path and measurement starts.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Hydraulic pump 2 Pulsation generator 3 Pressure gauge 4 Pressure pulsation absorber 5 Flow control valve 6 Pressure gauge

11 Membrane 11a Upper Membrane 11b Lower Membrane 11c Contact Part of Membrane
11c1 Upper membrane contact portion
11c2 Lower membrane contact portion 11d Upper membrane portion 11e Lower membrane portion 12 Foam 13 Pressure pulsation absorber 13a Hollow portion 14 Mold for molding a membrane 14a Mold for molding a membrane Die 14b Lower mold 14 for forming a film-like body 14c Mold cavity 15 Joining mold 15a Joining upper mold 15b Joining lower mold

Claims (10)

A pressure pulsation absorber for absorbing pulsation disposed in a pressure circuit, wherein the pressure pulsation absorber is formed of a foam made of an elastic body and a resin film enclosing the foam. A pressure pulsation absorber for absorbing pulsation disposed in a pressure circuit, comprising a foam made of an elastic body and a resin film made of an ethylene-vinyl alcohol copolymer enclosing the foam. Characteristic pressure pulsation absorber. The pressure pulsation absorber, wherein the ethylene-vinyl alcohol copolymer according to claim 2 has an ethylene content of 10 mol% to 70 mol%. A pressure pulsation absorber, wherein the resin film comprising the ethylene-vinyl alcohol copolymer according to claim 2 has a thickness of 1 to 1000 microns. A method for producing a pressure pulsation absorber for absorbing pulsation disposed in a pressure circuit, wherein a solution obtained by dissolving an ethylene-vinyl alcohol copolymer in a solvent is applied to a foam made of an elastic body, and then the solvent A method for producing a pressure pulsation absorber, wherein a resin film made of an ethylene-vinyl alcohol copolymer enclosing the foam is formed by removing the foam. The method for producing a pressure pulsation absorber, wherein the coating method according to claim 5 is a spray method. The method for producing a pressure pulsation absorber, wherein the coating method according to claim 5 is an immersion method. A method for producing a pressure pulsation absorber, wherein the solvent according to claim 5 is a mixture of alcohol and water. A method for producing a pressure pulsation absorber for absorbing pulsations arranged in a pressure circuit, wherein a film made of a resin is formed in a shape capable of covering a foam made of an elastic body by combining a single or a plurality in advance. A pressure pulsation absorber, characterized in that a film-like body is formed, the membrane-like body is disposed so as to cover the foam, and a contact portion between the film-like bodies made of resin is joined and sealed. Method. A method for producing a pressure pulsation absorber for absorbing pulsations arranged in a pressure circuit, wherein ethylene-vinyl alcohol is formed into a shape capable of covering a foam made of an elastic body by combining a single or a plurality of them in advance. A film-like body made of a copolymer is formed, and the film-like body is disposed in a state of covering the foam, and a contact portion between the film-like bodies made of a resin is joined and sealed. Manufacturing method of pressure pulsation absorber.