KR20110071164A - Diaphragm type accumulator - Google Patents

Abstract

PURPOSE: A diaphragm type accumulator is provided to suppress a gas permeability of diaphragm and to improve a processing efficiency and a life span. CONSTITUTION: The diaphragm type accumulator includes a rubber layer(81); and an adhesive layer(83). The rubber layer is composed of natural rubber 33~37 weight%, styrene-butadiene rubber 26~28 weight%, polyphenylene ether 1~2 weight%, carbon blank 1~2 weight%, zinc oxide 1~2 weight%, stearic acid 1~2 weight%, anti-aging agent 0.2~0.6 weight%, vulcanization accelerator 0.3~0.6 weight%, vulcanizate 0.4~1.0 weight%, retarder 0.4~0.8 weight%. The adhesive layer is composed of urethane prepolymer 20~24 weight%, zinc modified urethane resin 18~21 weight%, polyol 10~13 weight%, polyisocyanate compound 12~15 weight%, polyamide resin 10~13 weight%, epoxy resin 10~13 weight%, ethylendiamine 6~8 weight%, acetone 4~7 weight%.

Description

Diaphragm type accumulator

The present invention relates to an improvement of an accumulator.

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, 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.

As the prior art of the present invention, there is an accumulator shown in FIG.

4 is a cross-sectional view of a conventional accumulator. In FIG. 4, the shell 151 is spherical and has an oil inlet 152 at one end. The inside of the shell 51 is formed by the sealed space 153, and the sealed space 153 communicates with the oil inlet and outlet 152.

The sealed space 153 is divided into a gas chamber 154 and an oil chamber 155 by the diaphragm 160. And it is comprised so that oil may flow in and out from the oil inlet and outlet 152 in the oil chamber 152. FIG. The diaphragm 160 embeds the resin film 165 so that the gas in the gas chamber 154 does not permeate the oil chamber 155. The diaphragm 160 is made of a rubber material and is configured to have plasticity. In the accumulator 150 configured as described above, when oil flows in from the oil inlet and outlet 152, the diaphragm 160 tries to invert to the gas chamber 154, but the circumferential direction is formed in the abdomen 163 of the diaphragm 160. Accordingly, the bending deformation portion 164 occurs at various points. This is considered to be because the diaphragm 160 is provided with a resin film, so that shrinkage is not possible at the time of inversion and buckling occurs. When the curved portion 164 occurs, stress concentrates on the curved portion 164, causing cracking to cause damage.

In Japanese Unexamined Utility Model Publication No. HEI 5-66302, as shown in FIG. 5, the gas barrier resin layer 181 and the resin layer 181 integrally formed on both sides of the gas barrier are formed integrally with each other. The center of the inner elastic layer 183 is centered on the inner surface of the inner elastic layer 183 and the inner elastic layer 183 and the inner surface of the inner elastic layer 183 and the poppet 184 and the inner elastic layer 183. The structure is composed of a plurality of annular ribs 185 provided so as to extend in the circumferential direction.

Since the diaphragm 180 has the resin layer 181, rigidity becomes high, and it is practical to make the thickness dimension of the resin layer 181 and the elastic layers 182, 183, etc. completely uniform at the time of manufacture. Since it is impossible, there is a subtle gap in the stiffness of each part. Therefore, when the middle portion of the diaphragm 180 is bent and elastically deformed, deformation due to stress concentration occurs in a portion of low rigidity, and the portion is likely to buckle, and such buckling is repeatedly applied to the resin layer 181. If it occurs, cracks are generated and destroyed.

Thus, the diaphragm 180 is provided with a plurality of annular ribs 185 on the inner surface of the inner elastic layer 183, in order to prevent the deterioration in durability due to buckling at the bending deformation portion. Between the annular ribs 185 which are adjacent positions, the V-shaped ring groove is formed in cross section. Further, each annular rib 185 is formed in the same size in a trapezoidal shape in cross section.

By the way, as shown in FIG. 6, in order for the diaphragm 80 to elastically deform with the pressure change of the oil chamber 71, the center part in which the poppet 84 is installed is raised straightly without tilting, and it bends and deforms. Ideally, the position of the portion M is at the same position in the direction from the center portion side toward the outside. However, in manufacturing the diaphragm 80, the gap of the thickness dimension in the circumferential direction of the resin layer 81 and both elastic layers 82 and 83 inevitably arises. For this reason, when the diaphragm 80 actually deforms elastically, as shown in FIG. 7, the center part in which the poppet 84 is installed raises in an obliquely tilted state, and the position of the bending deformation | transformation part M moves to the center part side. It is often shifted in the direction toward the outer side. Thus, when the position of the bending deformation | transformation part M shifts in the direction from the center part side to the outer side, since stress concentrates at this point, a crack will arise and a damage will be caused.

In this way, when the diaphragm 80 is elastically deformed at an oblique angle, the position of the bending deformation portion M increases from one side to increase the deformation, or the diaphragm 80 is damaged by contact with the clamp ring 85. In other words, the durability of the diaphragm 80 is significantly reduced. In addition, a difference occurs in the elastic deformation of each diaphragm 80, which may be a factor of serious variation in durability.

On the other hand, Japanese Utility Model Laid-Open Patent Publication No. Hei 7-10505 has a ring shape around a poppet for a diaphragm that is formed in a substantially hemispherical shape, and has a thin thickness near the center of the poppet and becomes thicker toward the periphery. By providing one or more ribs, a technique is disclosed in which the diaphragm can expand to a normal shape, and can contract and restore to a normal shape.

Further, Japanese Patent Laid-Open No. 8-334101 discloses a diaphragm having a flexible portion near the open end in a substantially hemispherical shape, with a thick portion that gradually increases in thickness toward the center on the central side of the flexible portion. When a working fluid acts on a fram, a technique is disclosed to maintain a normal elastic deformation state to improve durability.

However, even in the diaphragm disclosed in Japanese Utility Model Laid-Open Publication No. Hei 7-10505 and Japanese Patent Laid-Open Publication No. Hei 8-334101, the gap in the thickness dimension in the circumferential direction during production is completely filled out. Since it is impossible to solve this problem, it is difficult to obtain an ideal state of elastic deformation in the diaphragm to a satisfactory level.

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 repeats 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 improving the service life by suppressing gas permeability of a diaphragm is proposed, which will be described with reference to FIGS. 8 to 11. FIG. 8 is a schematic sectional view showing a conventional accumulator in JP-A-3035326, and FIG. 9 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. 8, 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. 9, 32 is a diaphragm, 33 is a poppet, 51 is an elastic membrane, 52 is a resin layer, and 54 is a projection. In addition, Japanese Patent Laid-Open Publication No. 3030326 proposes a diaphragm of a form different from that shown in FIGS. 10 and 11. That is, FIG. 10 is an enlarged schematic diagram showing another example of a diaphragm conventionally used, and FIG. 11 is an enlarged schematic diagram showing another example of a diaphragm conventionally used. In the diaphragm of FIGS. 10 and 11, a resin layer 62 formed by laminating a resin film 63 on both sides of the resin, and an elastic layer 61 such as rubber laminated on both sides of the resin layer 62. It consists of a lamination | stacking, and lamination | stacking of each layer is performed with an adhesive agent. 10 and 11, 33 is a poppet, 61 is an elastic membrane, 62 is a resin layer, 64 is a protrusion, 65 is a diaphragm, 60 is a resin, and 63 is a resin film.

Fig. 12 is a partial cross-sectional explanatory view showing an enlarged main portion of a plastic film mounted in the main body of a conventional accumulator. In Japanese Laid-Open Patent Publication No. 9-111064, in order to suppress gas permeability of a diaphragm, as shown in FIG. 8, the plastic layer 47 has the intermediate | middle layer 40 and the flexible layer 42 laminated | stacked on both sides. , 42), and further, on the outside of each flexible layer 42, 42, to have an integral laminated structure consisting of seven layers of rubber layers 46, 46 laminated with adhesive layers 44, 44. It was.

On the other hand, in order to solve the above problems of the accumulator diaphragm, Japanese Patent Laid-Open No. 2747860 discloses an accumulator diaphragm shown in FIGS. 13 and 14. FIG. 9 is a cross-sectional view showing the structure of a conventional accumulator diaphragm, and FIG. 14 shows 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. 13 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 out of two substantially hemispherical dividing shells, and the The main corner portion is attached to the lower partition shell 71 by clamping the outer corner portion to the outer circumference of the ring-shaped support 71a and the inner circumferential edge of the opening portion of the lower partition 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 Unexamined Patent Publication No. 2747860 also proposes a manufacturing method of the accumulator diaphragm shown in FIGS. 15 to 17 as described below. FIG. 15 is a sectional view showing a layer structure between a central layer and an elastic layer of a composite layer used for a conventional accumulator diaphragm, FIG. 16 is a sectional view showing another configuration of a conventional accumulator diaphragm, 17 is a cross-sectional view showing still another configuration of a conventional accumulator diaphragm. While preparing EVOH (32% ethylene content, F-101 manufactured by Kuraray Co., Ltd.) as the center layer forming material, a polyamide resin (Super Tough Nylon ST811HS manufactured by DuPont) was prepared as an elastic layer forming material, and a rubber layer was formed. NBR was prepared as a material. Next, all of the above-described EVOH and polyamide resins were extruded from a extrusion machine at a predetermined thickness to prepare a composite layer having a three-layer structure shown in FIG. In FIG. 15, 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. 13) 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 shape 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. 16, 73 is a rubber layer, 71 'is a layer made of EVOH, and 72' is an elastic layer made of 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. 17, the accumulator diaphragm 77 of 13-layer structure was obtained. In FIG. 17, 73 is a rubber layer. In Figures 16 and 17, A represents the 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. Higher costs have led to higher consumer prices and difficult manufacturing.

The present invention solves the problems of the conventional accumulator diaphragm. The accumulator of the present invention allows the diaphragm to be stably deformed on the central axis when the working pressure changes, thereby preventing damage to the diaphragm. It is possible to prevent the gas permeability of the diaphragm, and to provide the accumulator which is easy to manufacture, the manufacturing cost is low, furthermore, the processing efficiency at the time of manufacturing and the remarkable long life of the accumulator are long. There is this.

The accumulator diaphragm 85 of the present invention comprises 33 to 37 wt% of natural rubber, 30 to 34 wt% of ethylene-α-olefin resin, 26 to 28 wt% of styrene butadiene rubber, and 1 to 2 wt% of polyphenylene ether. %, Carbon blanks 1-2 wt%, zinc oxide 1-2 wt%, stearic acid 1-2 wt%, anti-aging agent 0.2-0.6 wt%, vulcanization accelerator 0.3-0.6 wt%, vulcanizing agent 0.4-1.0 wt%, retardant 0.4- 20 to 24 wt% of urethane prepolymer, 18 to 21 wt% of zinc-modified urethane resin, 10 to 13 wt% of polyol, 12 to 15 wt% of polyisocyanate compound, 10 polyamide resin 30-34 wt% of vinyl-aromatic hydrocarbon polymers and rubber-modified styrene-based polymers using an adhesive layer 83 composed of -13 wt%, 10-13 wt% epoxy resin, 6-8 wt% ethyleneamine, and 4-7 wt% acetone. 24 to 28 wt%, polyolefin resin 10 to 14 wt%, rubbery polymer 9 to 13 wt%, rubber softener 2 to 4 wt The resin layer 82, which is a single layer composed of 6 to 8 wt% of ester and 8 to 12 wt% of glass fiber, is bonded to acrylic acid, and the resin layer 82 is placed on the nitrogen gas chamber 87 side. ) Is installed on the oil chamber 88 side, and a projection is placed on the inner and outer circumferential surfaces of the diaphragm 85, and the rubber layer thickness T1 of the diaphragm is the total thickness T of the diaphragm in which the resin layer and the rubber layer are combined. The inner peripheral surface side protrusion width t1 of the diaphragm is 1.1 to 2 times the total thickness T of the diaphragm, and the outer peripheral surface side protrusion width t2 is the range of 7/8 to 3/4 times. The range of 1.1 to 2 times the total thickness T of the diaphragm, and the distance f1 between the projections on the inner peripheral surface side of the diaphragm are the range of 6 to 12 times the total thickness T of the diaphragm, and the outer peripheral surface The distance f2 between the side projections is in a range of 6 to 12 times the total thickness T of the diaphragm, and the height h1 of the inner peripheral surface side of the diaphragm is 1.1 of the total thickness T of the diaphragm. And in the range of 1.8 times, the outer peripheral surface side of the projection height (h2) of the diaphragm is in the range of 1.1 to 1.8 times the total thickness (T) of the diaphragm.

The accumulator of the present invention allows the diaphragm to be stably deformed on the central axis when the working pressure fluctuates, thereby preventing damage to the diaphragm, suppressing the gas permeability of the diaphragm, and is easy to manufacture. It is inexpensive, the processing efficiency at the time of manufacture is high, and the accumulator has a long life.

Detailed description of the invention with reference to Figures 18 to 21 as follows.

Fig. 18 shows a cross-sectional view showing the structure of the accumulator diaphragm 85 of the present invention, Fig. 19 is a schematic cross-sectional view showing the structure of the accumulator diaphragm of the present invention. Sectional drawing which shows the structure of a accumulator diaphragm, FIG. 21 shows sectional drawing which shows the structure of the accumulator of this invention. In FIG. 18, 81 represents a rubber layer, 82 represents a resin layer, 83 represents an adhesive layer, and 85 represents a diaphragm. The accumulator diaphragm 85 of the present invention comprises 33 to 37 wt% of natural rubber, 30 to 34 wt% of ethylene-α-olefin resin, 26 to 28 wt% of styrene butadiene rubber, and 1 to 2 wt% of polyphenylene ether. %, Carbon blanks 1-2 wt%, zinc oxide 1-2 wt%, stearic acid 1-2 wt%, anti-aging agent 0.2-0.6 wt%, vulcanization accelerator 0.3-0.6 wt%, vulcanizing agent 0.4-1.0 wt%, retardant 0.4- 20 to 24 wt% of urethane prepolymer, 18 to 21 wt% of zinc-modified urethane resin, 10 to 13 wt% of polyol, 12 to 15 wt% of polyisocyanate compound, 10 polyamide resin 30-34 wt% of vinyl-aromatic hydrocarbon polymers and rubber-modified styrene-based polymers using an adhesive layer 83 composed of -13 wt%, 10-13 wt% epoxy resin, 6-8 wt% ethyleneamine, and 4-7 wt% acetone. 24 to 28 wt%, polyolefin resin 10 to 14 wt%, rubbery polymer 9 to 13 wt%, rubber softener 2 to 4 wt The resin layer 82, which is a single layer composed of 6 to 8 wt% of acrylate ester and 8 to 12 wt% of glass fiber, is bonded to each other, the resin layer 82 is placed on the nitrogen gas chamber 87 side, and the rubber layer 81 is It is installed on the oil chamber 88 side and puts projections on the inner circumferential surface and the outer circumferential surface of the diaphragm 85, and the rubber layer thickness (T1) of the diaphragm is 7 / of the total thickness (T) of the diaphragm in which the resin layer and the rubber layer are combined. The inner peripheral surface side projection width t1 of the diaphragm is 1.1 to 2 times the total thickness T of the diaphragm, and the outer peripheral surface side projection width t2 is the diaphragm. Of the total thickness (T) of 1.1 to 2 times, and the distance f1 between the inner peripheral surface side projections of the diaphragm is 6 to 12 times the total thickness T of the diaphragm, and the outer peripheral surface side projections The distance f2 between them is in the range of 6-12 times the total thickness T of the diaphragm, and the height h1 of the inner peripheral surface side of the diaphragm is 1.1 of the total thickness T of the diaphragm. And in the range of 1.8 times, the outer peripheral surface side of the projection height (h2) of the diaphragm is in the range of 1.1 to 1.8 times the total thickness (T) of the diaphragm. Fig. 19 shows a schematic cross-sectional view showing an accumulator provided with an accumulator diaphragm of the present invention. In Fig. 19, 81 is rubber layer, 82 is resin layer, 83 is adhesive layer, 84 is shell, 85 is diaphragm, 86 is holder, 87 is gas chamber, 88 is oil chamber, 89 is accumulator, 90 is oil entrance Indicates.

As used in Example 1 of Table 1, the accumulator diaphragm includes 33 wt% of natural rubber, 30 wt% of ethylene-α-olefin resin, 28 wt% of styrene butadiene rubber, 1.8 wt% of polyphenylene ether, and carbon. 20 wt% urethane prepolymer in rubber with a composition of 1.6 wt% blank, 1.6 wt% zinc oxide, 1.5 wt% stearic acid, 0.6 wt% anti-aging agent, 0.6 wt% vulcanization accelerator, 0.8 wt% vulcanizing agent, 0.5 wt% retardant , Vinyl aromatic hydrocarbon polymer using an adhesive composed of 18 wt% zinc-modified urethane resin, 10 wt% polyol, 12 wt% polyisocyanate compound, 13 wt% polyamide resin, 13 wt% epoxy resin, 8 wt% ethyleneamine, and 6 wt% acetone. 30kg%, rubber modified Styrene-based polymer 24wt%, polyolefin resin 10wt%, rubber-like polymer 12wt%, rubber softener 4wt%, acrylic ester 8wt%, glass fiber 12wt% composition by pressing 50kgf / cm ² was pressed and bonded, the thickness of the rubber layer after pressing was 1.3mm, the bonding layer was sandwiched between the rubber layer and the resin layer, and the total thickness of the bonded state by pressing the rubber layer and the resin layer was 1.5mm. The ground layer is placed on the nitrogen gas chamber side, the rubber layer is installed on the oil chamber side, and the projections are placed on the inner and outer circumferential surfaces of the diaphragm 85. 7/8 times the thickness T, the inner peripheral surface side protrusion width t1 of the diaphragm is 1.1 times the total thickness T of the diaphragm, and the outer peripheral surface side protrusion width t2 is the total thickness T of the diaphragm. The distance f1 between the inner peripheral surface side projections of the diaphragm is 6 times the total thickness T of the diaphragm, and the distance f2 between the outer peripheral surface side projections is the total thickness T of the diaphragm. The height of the inner peripheral surface side of the diaphragm (h1) is the total thickness of the diaphragm ( The accumulator as shown in FIGS. 18 and 21 was fabricated by making 1.1 times T) and making the height h2 of the outer peripheral surface side of the diaphragm 1.1 times the total thickness T of the diaphragm.

In addition, the diaphragm for accumulator used in Example 2 of Table 1 is 33 weight% of natural rubber, 30 weight% of ethylene-alpha-olefin resins, 28 weight% of styrene-butadiene rubbers, and 1.8 weight% of polyphenylene ethers. Urethane prepolymer in a rubber composed of 1.6 wt% carbon blank, 1.6 wt% zinc oxide, 1.5 wt% stearic acid, 0.6 wt% anti-aging agent, 0.6 wt% vulcanization accelerator, 0.8 wt% vulcanizing agent, 0.5 wt% retardant. 20% by weight, 18% by weight of zinc-modified urethane resin, 10% by weight of polyol, 12% by weight of polyisocyanate compound, 13% by weight of polyamide resin, 13% by weight of epoxy resin, 8% by weight of ethyleneamine, 6% by weight of acetone. Pressing resin layer composed of 30 wt% of hydrocarbon polymer, 24 wt% of rubber modified styrene polymer, 10 wt% of polyolefin resin, 12 wt% of rubbery polymer, 4 wt% of rubber softener, 8 wt% of acrylic ester, and 12 wt% of glass fiber And bonding under pressure of 50kgf / cm ^2, with a 1.3mm, a thickness of the bonding layer after the rubber layer is pressed between the rubber layer and a resin layer, were a total thickness of a bonding state by pressing the rubber layer and a resin layer to 1.5mm, The resin layer is placed on the nitrogen gas chamber side, the rubber layer is placed on the oil chamber side, and the projections are placed on the inner and outer circumferential surfaces of the diaphragm 85. 5/6 times the total thickness T, the inner peripheral surface side protrusion width t1 of the diaphragm is 1.5 times the total thickness T of the diaphragm, and the outer peripheral surface side protrusion width t2 is the total thickness of the diaphragm ( 1.6 times T), the distance f1 between the inner peripheral surface side projections of the diaphragm is 9 times the total thickness T of the diaphragm, and the distance f2 between the outer peripheral surface side projections is the total thickness T of the diaphragm. 9 times, and the height (h1) of the inner peripheral surface side of the diaphragm is equal to that of the diaphragm. 1.5 times the thickness (T), and the outer peripheral surface side of the projection height (h2) of the diaphragm to 1.5 times the total thickness (T) of the diaphragm was produced in the accumulator as shown in Figs. 18 and 21.

In addition, the diaphragm for accumulator used in Example 3 of Table 1 is 33 weight% of natural rubber, 30 weight% of ethylene-alpha-olefin resins, 28 weight% of styrene-butadiene rubbers, and 1.8 weight% of polyphenylene ethers. Urethane prepolymer in a rubber composed of 1.6 wt% carbon blank, 1.6 wt% zinc oxide, 1.5 wt% stearic acid, 0.6 wt% anti-aging agent, 0.6 wt% vulcanization accelerator, 0.8 wt% vulcanizing agent, 0.5 wt% retardant. 20% by weight, 18% by weight of zinc-modified urethane resin, 10% by weight of polyol, 12% by weight of polyisocyanate compound, 13% by weight of polyamide resin, 13% by weight of epoxy resin, 8% by weight of ethyleneamine, 6% by weight of acetone. Pressing resin layer composed of 30 wt% of hydrocarbon polymer, 24 wt% of rubber modified styrene polymer, 10 wt% of polyolefin resin, 12 wt% of rubbery polymer, 4 wt% of rubber softener, 8 wt% of acrylic ester, and 12 wt% of glass fiber And bonding under pressure of 50kgf / cm ^2, with a 1.3mm, a thickness of the bonding layer after the rubber layer is pressed between the rubber layer and a resin layer, were a total thickness of a bonding state by pressing the rubber layer and a resin layer to 1.5mm, The resin layer is placed on the nitrogen gas chamber side, the rubber layer is placed on the oil chamber side, and the projections are placed on the inner and outer circumferential surfaces of the diaphragm 85. 3/4 times the total thickness T, the inner peripheral surface side protrusion width t1 of the diaphragm is twice the total thickness T of the diaphragm, and the outer peripheral surface side protrusion width t2 is the total thickness of the diaphragm ( The distance f1 between the inner peripheral surface side projections of the diaphragm is 12 times the total thickness T of the diaphragm, and the distance f2 between the outer peripheral surface side projections is the total thickness T of the diaphragm. Of the diaphragm, the height of the protrusion on the inner peripheral surface side of the diaphragm h1 To 1.8-fold of the (T), and the outer peripheral surface side of the projection height (h2) of the diaphragm by 1.8 times the total thickness (T) of the diaphragm was produced in the accumulator as shown in Figs. 18 and 21.

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 sectional view of an accumulator of the prior art;

5 is a cross-sectional view of a conventional accumulator diaphragm;

6 is an explanatory diagram showing a deformed state of a conventional accumulator diaphragm;

7 is an explanatory diagram showing a deformed state of a conventional accumulator diaphragm;

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

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

10 is an enlarged schematic view showing another example of a diaphragm used in the prior art;

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

FIG. 12 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; FIG.

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

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

Fig. 15 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;

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

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

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

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

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

Fig. 21 is a sectional view showing the structure of an accumulator of the present invention.

[Description of the code]

81 rubber layers

82 resin layer

83 adhesive layer

84 shell

85 diaphragms

86 holder

87 gas chamber

88 oil seal

89 Accumulator

90 oil doorway

f1 Distance between protrusions on inner surface of diaphragm

f2 Distance between protrusions on the outer circumferential surface

h1 Diaphragm inner protrusion side height

Height of protrusion on the outer circumference of the diaphragm h2

Total thickness of diaphragm combining T resin layer and rubber layer

Rubber layer thickness of T1 diaphragm

t1 Diaphragm inner protrusion side width

t2 Outer surface side projection width

Claims (1)

Natural rubber 33 to 37 wt%, ethylene-α-olefin copolymer rubber 30 to 34 wt%, styrene butadiene rubber 26 to 28 wt%, polyphenylene ether 1 to 2 wt%, carbon blank 1 to 2 wt%, zinc oxide 1 to 2 wt %, Stearic acid 1-2 wt%, anti-aging agent 0.2-0.6 wt%, vulcanization accelerator 0.3-0.6 wt%, vulcanizing agent 0.4-1.0 wt%, retardant 0.4-0.8 wt% rubber layer 81 20 to 24 wt% of urethane prepolymer, 18 to 21 wt% of zinc-modified urethane resin, 10 to 13 wt% of polyol, 12 to 15 wt% of polyisocyanate compound, 10 to 13 wt% of polyamide resin, 10 to 13 wt% of epoxy resin, and ethyleneamine 6 30 to 34 wt% of vinylaromatic hydrocarbon polymer, 24 to 28 wt% of rubber-modified styrene-based polymer, 10 to 14 wt% of polyolefin resin, using adhesive layer 83 composed of 8 to 8 wt% and acetone 4 to 7 wt% 9 to 13 wt% of rubbery polymer, 2 to 4 wt% of rubber softener, 6 to 8 wt% of acrylate ester, glass fiber 8 The resin layer 82, which is a single layer having a composition of 12wt%, is bonded, 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, and the diaphragm is Projections are provided on the inner and outer peripheral surfaces of (85), and the rubber layer thickness (T1) of the diaphragm is in the range of 7/8 to 3/4 times the total thickness (T) of the diaphragm in which the resin layer and the rubber layer are combined. The inner peripheral surface side protrusion width t1 of the fram is in the range of 1.1 to 2 times the total thickness T of the diaphragm, and the outer peripheral surface side protrusion width t2 is 1.1 to 2 times the total thickness T of the diaphragm. The distance f1 between the inner peripheral surface side projections of the diaphragm is in the range of 6 to 12 times the total thickness T of the diaphragm, and the distance f2 between the outer peripheral surface side projections is the total thickness of the diaphragm. The projection height h1 of the inner peripheral surface side of the diaphragm is in a range of 1.1 to 1.8 times the total thickness T of the diaphragm, and the outer peripheral surface of the diaphragm The projection height (h2) is air, characterized in that in the 1.1 to 1.8-fold of the total thickness (T) of the diaphragm accumulator (89).

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