KR101082308B1 - Diaphram for accumulator - Google Patents

Abstract

This invention relates to the improvement of the diaphragm for accumulators.

In the conventional accumulator diaphragm having a resin layer in order to suppress gas permeability, the surface of the gas chamber and the surface of the inflow chamber are formed of a rubber layer, and are composed of three or more layers including both rubber layers. There was a problem that consumption is high in price and manufacturing is difficult.

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned conventional problems, which can suppress gas permeability, make it easy to manufacture, inexpensive to manufacture, and also have high processing efficiency at the time of manufacture, and a remarkably long accumulator life. Its purpose is to provide a diaphragm for a cumulator.

The diaphragm for the accumulator of the present invention is 50 to 58 wt% of acrylonitrile butadiene rubber, 10 to 15 wt% of organic peroxide, 6 to 10 wt% of sebacic acid-based polyester, 8 to 12 wt% of polyalkyrene fatty acid ester, and magnesium oxide 30 to 40 wt% of urethane prepolymer, 14 to 20 wt% of telphenphenol resin, and methyl ethyl to rubber layer 81, which is a single layer composed of 3 to 5 wt%, plasticizer 2 to 5 wt%, vulcanizing agent and 3 to 7 wt% of vulcanization accelerator. The degree of polymerization was 1500 using an adhesive layer 83 having a composition of 8-14 wt% ketone, 10-15 wt% ethyl acetate, 9-14 wt% isopropyl alcohol, 8-18 wt% plastic epoxy resin, and 5-10 wt% rubber latex. 36 to 42 wt% of the above-mentioned vinyl chloride resin, 12 to 18 wt% of chlorinated polyethylene, 7 to 11 wt% of ethylene vinyl alcohol copolymer, 8 to 15 wt% of acrylonitrile, 6 to 10 wt% of methacrylic acid ester copolymer, and polyamide resin 9 15 wt% to 7-12 wt% of ethylene vinyl alcohol copolymer The resin layer 82, which is a single layer composed of the composition, is bonded to each other, the resin layer 82 is placed on the nitrogen gas chamber 87 side, and the rubber layer 81 is provided on the oil chamber 88 side.

The accumulator diaphragm of the present invention can suppress gas permeability, is easy to manufacture, is inexpensive to manufacture, furthermore, has high processing efficiency at the time of manufacturing, and has a remarkably long life of the accumulator. .

Accumulator, Diaphragm, Rubber, Resin, Gas, Oil

Description

Diaphragm for accumulator

This invention relates to the improvement of the diaphragm for accumulators.

In general, the accumulator 20, which is generally adapted to absorb accumulation of high pressure fluid in the flow path or pulsation of the fluid in the flow path, has a configuration as shown in FIG.

That is, a diaphragm 20 made of an elastic body such as rubber is attached to the inside of the shell 26 formed in a spherical shape by the holder 13, and the inside is divided into two sealed spaces and one sealed space for gas encapsulation. In the gas chamber 21, the other sealed space is formed in the oil chamber 22 serving as the fluid inflow chamber.

In this case, since the diaphragm 24 is made of a material having a gas permeability such as rubber, the gas inside the gas chamber 21 gradually penetrates the diaphragm 24 and is used for a long time. The pressure inside the gas chamber 21 was very low, and there was a problem that control of a stable fluid pressure was impossible.

2 is a schematic cross-sectional view showing an operating state in which pressure is applied to the oil chamber side in a conventional accumulator, and FIG. 3 is a schematic cross-sectional view showing an operating state in which pressure is applied to the oil chamber side in a conventional accumulator. . 3M is a bending point in the diaphragm in the operating state in which the oil chamber side is pressurized in the accumulator, and damage is likely to occur at this bending point M due to fatigue stress during long periods of repeated use. Therefore, the diaphragm of the accumulator requires not only the gas permeability during use, but also the predetermined durability according to the cyclic stress during use. 23 of FIG. 2 shows the oil inlet and 27 of FIG. 3 shows the poppet.

On the other hand, there has been an attempt to suppress gas permeability by adding an additive to the rubber material constituting the diaphragm. However, in this way, the gas permeability of the rubber is suppressed, but the flexibility of the accumulator diaphragm itself is lowered, and a new problem of cracking and the like in a long time of use occurs.

In order to solve the above problems, Japanese Patent Laid-Open No. 2-165948 discloses a rubber resin composite film in which an ethylene vinyl alcohol resin film is provided with an adhesive layer interposed between rubber thin films. In the case of forming an accumulator diaphragm using such a composite membrane, the ethylene vinyl alcohol resin membrane is excellent in gas permeation resistance, so that the gas encapsulation pressure can be maintained for a long time, but rubber-resin When the composite membrane is used for a long time, that is, when the number of bending repetitions in use increases, cracks and peeling occur in the ethylene vinyl alcohol copolymer (EVOH) membrane. Therefore, an accumulator using such an accumulator diaphragm has a problem that the service life is significantly reduced.

In Japanese Patent Laid-Open No. 3053526, a technique for suppressing gas permeability of a diaphragm and improving a lifetime has been proposed, which will be described with reference to FIGS. 4 to 7. 4 is a schematic cross-sectional view showing a conventional accumulator in JP-A-3035326, and FIG. 5 is an enlarged schematic view showing a diaphragm used in the related art. The diaphragm is composed of a resin layer 52 for suppressing gas permeability and an elastic body 51 such as rubber laminated on both surfaces of the resin layer 52 using an adhesive. In FIG. 4, 61 represents the shell of the accumulator, 62 is the diaphragm, 63 is the poppet, 64 is the holder, 65 is the oil poppet, 66 is the gas flag, 67 is the O-ring, 68 is the gas inlet, 69 Represents an oil inlet, 21 represents a gas chamber, and 22 represents an oil chamber. In Fig. 5, 32 denotes a diaphragm, 33 denotes a poppet, 51 denotes an elastic membrane, 52 denotes a resin layer, and 54 denotes projections. In addition, Japanese Patent Laid-Open Publication No. 3030326 proposes a diaphragm of a form different from that shown in Figs. 6 and 7. That is, FIG. 6 is an enlarged schematic diagram showing another example of a diaphragm conventionally used, and FIG. 7 shows an enlarged schematic diagram showing another example of a diaphragm conventionally used. In the diaphragm of FIG. 6 and FIG. 7, the resin layer 62 formed by laminating | stacking the resin film 63 on both sides of resin, and the elastic layer 61, such as rubber laminated on both sides of this resin layer 62, is formed. It consists of a lamination | stacking and lamination | stacking of each layer is performed with an adhesive agent. 6 and 7, 33 represents a poppet, 61 an elastic membrane, 62 a resin layer, 64 a protrusion, 65 a diaphragm, 60 a resin, and 63 a resin film.

Fig. 8 is an enlarged partial cross-sectional view showing a main portion of a plastic film attached to the inside of a main body of a conventional accumulator. In Japanese Laid-Open Patent Publication No. Hei 9-111064, gas permeability of a diaphragm is shown. In order to suppress this, as shown in FIG. 8, the plastic film 47 arrange | positions the intermediate | middle layer 40 and the flexible layers 42 and 42 which were laminated | stacked on both sides, and further, the adhesive agent outside each flexible layer 42 is carried out. It was configured to have an integral laminated structure consisting of seven layers of rubber layers 46 and 46 laminated with layers 44 and 44.

On the other hand, in order to solve the above problems of the accumulator diaphragm, Japanese Patent Laid-Open No. 2747860 proposes an accumulator diaphragm shown in FIGS. 9 and 10. FIG. 9 is a cross-sectional view showing the structure of a conventional accumulator diaphragm, and FIG. 10 is a partial cross-sectional view of the accumulator diaphragm provided with the accumulator diaphragm of FIG. As the rubber layer, conventionally known acrylonitrile butane rubber (NBR) and the like were used. As a center layer, the elastic layer made of a polyamide resin on the upper and lower surfaces of the upper and lower sides were formed integrally to constitute a composite layer. In this case, since the bonding interface between the ethylene vinyl alcohol copolymer (EVOH) and the elastic layer made of a polyamide resin is adhered by the reaction of both, no adhesive is required. Next, the conventionally well-known adhesive agent was apply | coated to the upper and lower surfaces of this composite layer, the rubber layer was press-molded by the press, and vulcanized adhesion was carried out. 9 of Japanese Patent Laid-Open No. 2747860 shows the structure of an accumulator diaphragm manufactured by this method. The accumulator diaphragm thus obtained is positioned at the inner circumferential edge of the opening of the lower dividing shell 71 among the two roughly hemispherical dividing shells, and the main edge is positioned. The main edge portion is attached to the lower divided shell 71 by clamping the outer edge of the ring-shaped support 71a to the inner peripheral edge of the opening of the lower divided shell 71. And the accumulator 70 was comprised by carrying out the electron beam welding etc. to the opening part of the upper division shell 70a to the opening part of this lower division shell 71. In the figure, 73 is a poppet.

Japanese Patent Laid-Open No. 2747860 also proposes a manufacturing method of the accumulator diaphragm shown in Figs. 11 to 13 as described below. FIG. 11 is a cross-sectional view showing the layer structure of the center layer and the elastic layer of the composite layer used for the conventional accumulator diaphragm, FIG. 12 is a cross-sectional view showing another structure of the conventional accumulator diaphragm, It is sectional drawing which shows the further another structure of the conventional accumulator diaphragm. EVOH (32% ethylene content, F-101 manufactured by Kuraray Co., Ltd.) was prepared as the center layer forming material, and a polyamide resin (Super Tough Nylon ST811HS manufactured by DuPont) was prepared as the elastic layer forming material. NBR was prepared as a material. Next, the EVOH and the polyamide resin were all extruded from an extrusion molding machine at a predetermined thickness to prepare a composite layer having a three-layer structure shown in Fig. 11. In FIG. 11, 71 is a center layer made of EVOH, and 72 is an elastic layer made of polyamide resin. Next, a conventionally well-known adhesive agent was apply | coated to each of the upper and lower surfaces of the said composite layer, Furthermore, after press-molding NBR to a predetermined thickness using a press machine, it vulcanized and bonded. In this way, a diaphragm 77 (see Fig. 9) for elastic thin plate accumulators having a five-layer structure was obtained.

In addition, a composite layer having a seven-layer structure was produced by extruding together from the extrusion machine in the same manner as described above. Next, a conventionally well-known adhesive is applied to each of the upper and lower surfaces of the composite layer, and further press-molded NBR rubber into a layer to have a predetermined thickness by using a press machine, and then vulcanized and bonded to the nine layers as shown in FIG. The accumulator diaphragm 77 of the structure was obtained. In Fig. 12, 73 is a rubber layer, 71 'is a layer made of EVOH, and 72' is an elastic layer made of a polyamide resin.

Meanwhile, in the above-described method, an extruder was extruded together to produce an 11-layered composite layer. Next, a conventionally known adhesive was applied to each of the upper and lower surfaces of the composite layer, and further, NBR was applied using a press. It was vulcanized and adhered after press molding into a layer with a predetermined thickness. Thus, as shown in FIG. 13, the accumulator diaphragm 77 of 13-layer structure was obtained. In Fig. 13, 73 is a rubber layer. 12 and 13, A represents an inner sublayer.

In the conventional accumulator diaphragm having a resin layer in order to suppress gas permeability as described above, the surface of the gas chamber and the surface of the inflow chamber are formed of a rubber layer, and are composed of three or more layers including both rubber layers. The high cost has made consumption expensive and difficult to manufacture.

The present invention is to solve the problems of the conventional accumulator diaphragm, the accumulator diaphragm of the present invention can suppress gas permeability, easy to manufacture, low production cost, Moreover, the objective is to provide the accumulator diaphragm which has high processing efficiency at the time of manufacture, and whose accumulator life is remarkably long.

The diaphragm 85 for an accumulator of this invention is 50-58 wt% of acrylonitrile butadiene rubbers, 10-15 wt% of organic peroxides, 6-10 wt% of sebacic acid type polyesters, and 8-12 wt% of polyalkyrene fatty acid esters. 30-40 wt% of urethane prepolymer, 14-20 wt% of telphenphenol resin, in rubber layer 81, which is a single layer composed of 3-5 wt% of magnesium oxide, 2-5 wt% of plasticizer, 3-7 wt% of vulcanizing agent and vulcanization accelerator. Using an adhesive layer 83 having a composition of 8 to 14 wt% methyl ethyl ketone, 10 to 15 wt% ethyl acetate, 9 to 14 wt% isopropyl alcohol, 8 to 18 wt% plastic epoxy resin, and 5 to 10 wt% rubber latex. 36-42 wt% of vinyl chloride resins with a degree of polymerization of 1500 or more, 12-18 wt% of chlorinated polyethylene, 7-11 wt% of ethylene vinyl alcohol copolymer, 8-15 wt% of acrylonitrile, 6-10 wt% of methacrylic acid ester copolymer, poly 9-15 wt% of amide resin, 7-12 wt% of ethylene vinyl alcohol copolymer The resin layer 82, which is a single layer having a composition of A, is bonded to each other, the resin layer 82 is placed on the nitrogen gas chamber 87 side, and the rubber layer 81 is provided on the oil chamber 88 side.

The accumulator diaphragm of the present invention can suppress gas permeability, is easy to manufacture, has a low manufacturing cost, furthermore has high processing efficiency at the time of manufacturing, and has an effect of significantly longer life of the accumulator. .

A detailed description of the present invention will be given below with reference to FIGS. 14 and 15.

Fig. 14 is a sectional view showing the configuration of the accumulator diaphragm 85 of the present invention. In Fig. 14, 81 represents a rubber layer, 82 represents a resin layer, 83 represents an adhesive layer, and 85 represents a diaphragm. The diaphragm 85 for an accumulator of this invention is 50-58 wt% of acrylonitrile butadiene rubbers, 10-15 wt% of organic peroxides, 6-10 wt% of sebacic acid type polyesters, and 8-12 wt% of polyalkyrene fatty acid esters. 30-40 wt% of urethane prepolymer, 14-20 wt% of telphenphenol resin, in rubber layer 81, which is a single layer composed of 3-5 wt% of magnesium oxide, 2-5 wt% of plasticizer, 3-7 wt% of vulcanizing agent and vulcanization accelerator. Using an adhesive layer 83 having a composition of 8 to 14 wt% methyl ethyl ketone, 10 to 15 wt% ethyl acetate, 9 to 14 wt% isopropyl alcohol, 8 to 18 wt% plastic epoxy resin, and 5 to 10 wt% rubber latex. 36-42 wt% of vinyl chloride resins with a degree of polymerization of 1500 or more, 12-18 wt% of chlorinated polyethylene, 7-11 wt% of ethylene vinyl alcohol copolymer, 8-15 wt% of acrylonitrile, 6-10 wt% of methacrylic acid ester copolymer, poly 9-15 wt% of amide resin, 7-12 wt% of ethylene vinyl alcohol copolymer The resin layer 82, which is a single layer having a composition of A, is bonded to each other, the resin layer 82 is placed on the nitrogen gas chamber 87 side, and the rubber layer 81 is provided on the oil chamber 88 side. Fig. 15 shows a schematic cross-sectional view showing an accumulator provided with an accumulator diaphragm of the present invention. In Fig. 15, 81 represents a rubber layer, 82 represents a resin layer, 83 represents an adhesive layer, 85 represents a diaphragm, 87 represents a gas chamber, 88 represents an oil chamber, and 89 represents an accumulator.

The diaphragm for the accumulator used in Example 1 of Table 1 was acrylonitrile butadiene rubber 54 wt%, organic peroxide 11 wt%, sebacic acid type polyester 9 wt%, polyalkyrene fatty acid ester 11wt%, magnesium oxide 5wt %, Plasticizer 4wt%, vulcanizing agent and vulcanization accelerator 6wt% in composition, urethane prepolymer 30t%, telphenphenol resin 15wt%, methyl ethyl ketone 13wt%, ethyl acetate 14wt%, isopropyl alcohol 12wt%, plastic epoxy Using an adhesive composed of 8 wt% resin and 8 wt% rubber latex, 37 wt% vinyl chloride resin, 13 wt% chlorinated polyethylene, 8 wt% ethylene vinyl alcohol copolymer, 9 wt% acrylonitrile, and methacrylic acid ester A resin layer having a composition of 7 wt% of a copolymer, 14 wt% of a polyamide resin, and 12 wt% of an ethylene vinyl alcohol copolymer was bonded to each other, and the resin layer was placed on the nitrogen gas chamber side. The installed on the oil chamber side, it was produced in the accumulator as shown in FIGS.

In addition, the accumulator diaphragm used in Example 2 of Table 1 is 55 wt% of acrylonitrile butadiene rubber, 15 wt% of organic peroxide, 8 wt% of sebacic acid type polyester, 10 wt% of polyalkyrene fatty acid ester, and oxidation In a rubber composed of 3wt% magnesium, 3wt% plasticizer, 6wt% vulcanizing agent and vulcanization accelerator, 35wt% urethane prepolymer, 17wt% telphenphenol resin, 12wt% methyl ethyl ketone, 12wt% ethyl acetate, 9wt% isopropyl alcohol, Using an adhesive composed of 10 wt% of a plastic epoxy resin and 5 wt% of rubber latex, 39 wt% of a vinyl chloride resin having a degree of polymerization of 1500 or more, 12 wt% of chlorinated polyethylene, 9 wt% of ethylene vinyl alcohol copolymer, 12 wt% of acrylonitrile, and meta A resin layer having a composition of 8 wt% of an acrylic acid ester copolymer, 9 wt% of a polyamide resin and 11 wt% of an ethylene vinyl alcohol copolymer was bonded together, and the resin layer was placed on the nitrogen gas chamber side. And a rubber layer were installed in the oil chamber side, and the accumulator as shown in FIG. 14 and FIG. 15 was produced.

In addition, the diaphragm for accumulator used in Example 3 of Table 1 is 58 weight% of acrylonitrile butadiene rubber, 13 weight% of organic peroxides, 7 weight% of sebacic acid type polyesters, 9 weight% of polyalkyrene fatty acid esters, and oxidation In a rubber composed of 5 wt% of magnesium, 3 wt% of a plasticizer, 5 wt% of a vulcanizing agent and a vulcanization accelerator, 39 wt% of a urethane prepolymer, 14 wt% of telphenphenol resin, 8 wt% of methyl ethyl ketone, 11 wt% of ethyl acetate, 10 wt% of isopropyl alcohol, Using an adhesive composed of 9 wt% of a plastic epoxy resin and 9 wt% of rubber latex, 42 wt% of vinyl chloride-based resin having a degree of polymerization of 1500 or more, 17 wt% of chlorinated polyethylene, 7 wt% of ethylene vinyl alcohol copolymer, 8 wt% of acrylonitrile, and metaacryl rilsan ester copolymer 6wt%, 12wt% polyamide resin, ethylene vinyl alcohol copolymer and adhesive to the pressing of 50㎏f / cm ² the resin composition of 8wt% with a press, and The thickness of the subsequent rubber layer was 1.3 mm, the bonding layer was sandwiched between the rubber layer and the resin layer, and the total thickness in the state where the rubber layer and the resin layer were pressurized and bonded was 1.5 mm. The resin layer was placed on the nitrogen gas chamber side, and the rubber layer was It mounted in the oil chamber side and produced the accumulator as shown in FIG. 14 and FIG.

In addition, N ₂ gas was sealed in the gas chamber 87 at a closing pressure of 5 MPa, and at the same time, the oil chamber 88 was filled with an oil containing a viscosity-inhibiting agent (Pentosin CHF11S). The pressure of 0 MPa and 10 MPa was repeatedly applied to the oil chamber 88 under alternating conditions at room temperature, and the durability was tested. The nitrogen gas permeability and durability test (0 MPa to 10 MPa after the durability test (0 MPa to 10 MPa, 10,000 times)) were tested. Oil permeability after 10,000 cycles, bond crack after durability test (0 MPa to 10 MPa, 10,000 cycles), rubber layer damage after durability test (0 MPa to 10 MPa, 10,000 cycles), resin layer damage after durability test (0 MPa to 10 MPa, 10,000 cycles) The presence or absence of abnormality such as initial nitrogen gas permeability and flexibility was measured and evaluated.

As shown in Table 1, the accumulator diaphragm of Examples 1 to 3 of the present invention has a nitrogen gas permeability and durability test (0 MPa to 10 MPa, 10,000 times) after the durability test (0 MPa to 10 MPa, 10,000 times). Oil permeability after), cracks at the bond after durability test (0 MPa to 10 MPa, 10,000 times), rubber layer damage after durability test (0 MPa to 10 MPa, 10,000 times), resin layer damage after durability test (0 MPa to 10 MPa, 10,000 times), initial nitrogen It can be seen that it has remarkably excellent performance in terms of gas permeability and flexibility.

1 is a schematic cross-sectional view showing a conventional accumulator,

2 is a schematic cross-sectional view showing an operating state in which a pressure is not applied to the oil chamber side in a conventional accumulator;

3 is a schematic cross-sectional view showing an operating state in which pressure is applied to an oil chamber side in a conventional accumulator;

4 is a schematic cross-sectional view showing a conventional accumulator;

5 is an enlarged schematic view showing a diaphragm conventionally used;

6 is an enlarged schematic view showing another example of a diaphragm conventionally used;

7 is an enlarged schematic view showing another example of a diaphragm conventionally used;

Fig. 8 is a partial cross-sectional explanatory view showing an enlarged portion of a plastic film attached to the inside of the main body in a conventional accumulator;

9 is a cross-sectional view showing the structure of a conventional accumulator diaphragm;

10 is a partial cross-sectional view of the accumulator diaphragm provided with the accumulator diaphragm of FIG. 9;

11 is a cross-sectional view showing a layer structure between a central layer and an elastic layer of a composite layer used for a conventional accumulator diaphragm;

12 is a cross-sectional view showing another configuration of a conventional accumulator diaphragm;

13 is a cross-sectional view showing another configuration of a conventional accumulator diaphragm;

14 is a cross-sectional view showing the configuration of an accumulator diaphragm of the present invention;

Fig. 15 is a schematic cross-sectional view showing an accumulator provided with an accumulator diaphragm of the present invention.

[Description of the code]

81 rubber layers

82 resin layer

83 adhesive layer

85 diaphragms

87 gas chamber

88 oil seal

89 Accumulator

Claims (1)

50 to 58 wt% of acrylonitrile butadiene rubber, 10 to 15 wt% of organic peroxide, 6 to 10 wt% of sebacic acid-based polyester, 8 to 12 wt% of polyalkyrene fatty acid ester, 3 to 5 wt% of magnesium oxide, 2 to 5 wt% of plasticizer, In the rubber layer 81, which is a single layer composed of a vulcanizing agent and a vulcanizing accelerator, of 3 to 7 wt%, 30 to 40 wt% of urethane prepolymer, 14 to 20 wt% of telphenphenol resin, 8 to 14 wt% of methyl ethyl ketone, and 10 to 15 wt of ethyl acetate %, 36 to 42 wt% of vinyl chloride-based resins having a degree of polymerization of 1500 or more by using an adhesive layer 83 having a composition of 9 to 14 wt% of isopropyl alcohol, 8 to 18 wt% of plastic epoxy resin, and 5 to 10 wt% of rubber latex. 12 to 18 wt% polyethylene, 7 to 11 wt% ethylene vinyl alcohol copolymer, 8 to 15 wt% acrylonitrile, 6 to 10 wt% methacrylic acid ester copolymer, 9 to 15 wt% polyamide resin, 7 to 7 ethylene vinyl alcohol copolymer Bonding resin layer 82, which is a single layer, having a composition of 12wt% Kigo, the resin layer 82, a diaphragm for the accumulator, characterized in that the place, installing the rubber layer 81 in the oil chamber 88 side on the side of the nitrogen gas chamber (87).

Images