JP3692638B2 - Metal bellows accumulator - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a metal bellows accumulator that uses a metal bellows installed in a hydraulic circuit in order to absorb hydraulic pulsation in a hydraulic device or the like.
[0002]
[Prior art]
Conventionally, accumulators of various shapes have been proposed according to various applications. For example, a hollow container is known in which a liquid bellows and a gas chamber are separated by a metal bellows, a compressed gas is sealed in the gas chamber, and the liquid chamber is filled with oil. The metal bellows can be expanded and contracted in the axial direction of the container, the liquid chamber is defined on either the inner surface or the outer surface of the bellows, the gas chamber is defined on the other side, and the pressure change in the liquid chamber or gas chamber The bellows expands and contracts accordingly.
[0003]
An example of the prior art is shown in FIG. The accumulator 100 is provided between a hydraulic pump 111 and a hydraulic device 112 that is moved by the pump 111. In this accumulator 100, an inner cylinder 102 and a metal bellows 103 are provided concentrically inside a container 101, and the liquid chamber 104 and the gas chamber 105 are separated by the bellows 103.
[0004]
The inner cylinder 102 is provided with a flow port 106 through which oil flows in accordance with the expansion and contraction of the bellows 103, and a sealing material 110 is provided on the inner surface side of the cap member 109 that closes one end of the bellows 103. The sealing material 110 and the annular valve seat 107 around the circulation port 106 face each other, and oil is confined between the inner cylinder 102 and the bellows 103 when the bellows 103 is contracted by a predetermined stroke or more. The self-sealing means 108 is configured. The liquid chamber 104 is filled with oil, and the gas chamber 105 is filled with compressed gas.
[0005]
Accordingly, the oil discharged from the hydraulic pump 111 flows into the liquid chamber 104 via the inflow side pipe 113 and the port 114, and the oil that flows into the liquid chamber 104 passes through the outflow port 115 and the outflow side pipe 116. To the hydraulic device 112. At this time, a hydraulic pulsation component generated by the rotation of the pump 111 acts on the liquid chamber 104 and also acts on the gas chamber 105 through the oil in the liquid chamber 104. Therefore, the pulsating component is absorbed by the compression / expansion of the gas in the gas chamber 105. When the gas chamber 105 is compressed, the bellows 103 is bent in the extending direction, and when the gas chamber 105 is expanded, the bellows 103 is bent in the contracting direction. In this way, the volume change of the oil discharged from the pump 111 is replaced with the volume change of the gas in the gas chamber 105.
[0006]
[Problems to be solved by the invention]
However, the cap member 109 hermetically attached to the end portion of the metal bellows 103 in the accumulator 100 as described above is fixed by conventional welding. This situation is shown enlarged in FIG. 10 and FIG.
[0007]
That is, as shown in the figure, the cap member 109 is made of a metal plate having a cutting edge 117 and a sealing material 110 that opens and closes the flow port 106, and this is welded 118 to the end of the metal bellows 103. Fixed by.
However, since the sealing material 110 is formed of an elastic material such as rubber and attached by vulcanization adhesion, the cap member 109 has a peripheral edge after the rubber is bonded when the groove of the welded portion 118 is cut. Since cutting is performed, rubber may be damaged, and there is a problem that rubber characteristics (seal characteristics) are locally degraded by welding heat.
[0008]
Moreover, sufficient care and jigs are provided so that the groove processing and the welding work do not lower the assembly efficiency of the accumulator body, and do not damage the sealing material 110 or deteriorate the sealing material 110 by welding heat as described above. Etc., the manufacturing process and time are lengthened, which increases the cost.
[0009]
Furthermore, as shown in FIG. 10, it seems to be an influence of the edge portion 119 formed by the cutting of the plate 109, but the effect of welding becomes insufficient, and there is a slight problem with the airtight function at the welded portion 118.
[0010]
The present invention has been made in order to solve the above-described problems, makes it easier to remove the thermal stress in the welding of the metal bellows to the cap member, and facilitates the mounting of rubber on the cap member. An object of the present invention is to provide a metal bellows accumulator which does not deteriorate the quality of a sealing material due to welding.
[0011]
[Means for Solving the Problems]
In order to achieve the above object, a metal bellows accumulator according to the invention of claim 1 is accommodated in a container and one end of which is hermetically attached to the container, and the container is partitioned into a liquid chamber and a gas chamber. A metal bellows that can be expanded and contracted in the axial direction of the container, a cap member that closes the other end of the metal bellows, and provided at a position that communicates with the liquid chamber and faces the cap member. And a cap that has a sealing material, and that constitutes a self-sealing means for closing the circulation port when the metal bellows is stroked more than a predetermined stroke. A bellows accumulator, wherein the cap member has a plate fixed to the other end of the metal bellows by welding, Sealing material interior sealing member mounting member is bonded to Lumpur material or the core material, is attached by mechanical fixing means, said mechanical fixing means, Totsugata or concave is formed in the plate, the sealing material In the sealing material mounting member or the sealing material in which the core material is bonded, a concave portion or a convex portion corresponding to the convex shape or concave shape of the plate is formed, and this convex shape or concave shape and the corresponding concave portion or convex portion are formed. Are fixed to each other .
[0012]
The metal bellows accumulator according to the invention of claim 2 is accommodated in a container and one end of which is hermetically attached in the container, and is expanded and contracted in the axial direction of the container that separates the container into a liquid chamber and a gas chamber. A free metal bellows, a cap member that closes the other end of the metal bellows, and provided at a position that communicates with the liquid chamber and faces the cap member. A metal bellows accumulator that constitutes a self-sealing means for closing the circulation port in a state in which the cap member has a sealing material and the metal bellows has stroked more than a predetermined stroke. In the cap member, a plate is fixed to the other end of the metal bellows by welding, and a seal material is bonded to the plate. Sealing material furnished the timber mounting member or core, is attached by mechanical fixing means, said mechanical fixing means, the cap fitting is secured to the plate, a plurality of pressing pieces on the outer circumference of the cap fitting And the guide pieces that are in sliding contact with the inner wall surface of the container are alternately projected, and the seal material mounting member or the seal material that has the core material bonded thereto is overlapped with the cap metal fitting and the presser piece is bent. It is characterized by being pressed and fixed.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view showing an embodiment of the present invention, and FIG. 2 is an enlarged cross-sectional view of a main part showing an embodiment of the present invention. Metal Bellows accumulator shown in FIG. 1 is provided between the hydraulic pump as in the conventional example shown in FIG. 9, a hydraulic device driven by the pump.
[0016]
This metal bellows accumulator includes a hollow container 1, which has a flow port 2 for fluid such as oil at one end and an opening 3 at the other end. A mounting flange 5 having a mounting hole 4 is projected.
[0017]
A bellows base 7 having an O-ring 6 on the outer periphery is fitted into the opening 3 so as to hermetically close the opening 3. The bellows base 7 has a plug hole 8 as a gas filling port formed in the center thereof, and a gas plug 9 is attached to the plug hole 8.
The bellows base 7 is securely fixed so as not to move between a ring-shaped stopper step 1a on the inner periphery of the container 1 and an opening edge 1b obtained by bending the opening 3 of the container 1 inward. In order to adjust the maximum stress and height of the metal bellows 10, a ring having a predetermined thickness can be interposed between the bellows base 7 and the opening edge 1b as necessary.
[0018]
One end of the metal bellows 10 is fixed to the peripheral edge of the bellows base 7 by welding or the like, and is extendable in the axial direction of the container 1. The other end of the metal bellows 10 is closed by a cap member 11.
[0019]
The cap member 11 includes a thin cap metal fitting 11a in which a peripheral portion (not indicated by reference numeral, see FIG. 4) sagged in a circular arc shape by punching is fixed to the outer periphery 10a of the metal bellows 10 by welding as shown in FIG. The guide cap metal fitting 11b integrated so as to overlap the cap metal fitting 11a and the sealing material 11c that houses the core material 11d are pressed and fixed by the pressing piece 11e of the cap metal fitting 11b. Yes.
[0020]
In other words, the cap fittings 11a and 11b are fixed integrally, and the cap fitting 11a is fixed to the end of the metal bellows 10 by welding or the like. As shown in FIG. 3, the cap fitting 11b has a pressing piece 11e and a guide piece 11f projecting radially on the outer periphery, and the sealing material 11c is overlapped with the cap fitting 11b, and the holding piece 11e is bent as shown in FIG. It is pressed and attached.
[0021]
The presser piece 11e may be not only bent as shown in FIG. 2, but also crimped as shown in FIG.
The guide piece 11f has a tip that is curved, and the tip is in sliding contact with the inner wall surface of the container 1 for movement.
[0022]
Thus, the inside of the container 1 is partitioned by the bellows 10, a gas chamber G is defined on the inner surface side of the bellows 10, and an inert gas such as nitrogen is sealed in the gas chamber G, and the outer surface of the bellows 10 and the container 1 A liquid chamber L is provided on the side defined by the inner wall and filled with oil. The flow port 2 is connected so as to communicate with the hydraulic circuit side, and the hydraulic pressure of the hydraulic circuit communicates with the liquid chamber L in the container 1 through the flow port 2.
[0023]
Accordingly, the cap member 11 is pushed open or pulled back in accordance with the hydraulic pressure fluctuation of the hydraulic circuit, and the metal bellows 10 is compressed or decompressed (expanded), so that the internal gas is also compressed or expanded. It can absorb hydraulic pressure fluctuations and pulsations in the circuit.
[0024]
Further, when the hydraulic pressure falls below the gas pressure enclosed in the metal bellows 10, the sealing material 11c of the cap member 11 seals the flow port 2, and oil having a pressure equal to the gas pressure of the gas chamber G is supplied to the liquid chamber. It is confined to L so that no differential pressure is applied to the metal bellows 10.
[0025]
And in the said embodiment, there is no operation | work which gives a groove process to a thick plate unlike the past, Therefore, the welding of the metal bellows end with respect to an edge part is lose | eliminated, and between the members with a thin plate | board thickness of a welding part mutually In addition, since welding is performed at the peripheral edge R of the cap fitting 10a that is bent in an arc shape, the welding state is extremely good as shown in FIG. According to the experiment, when the ratio T / t between the thickness T of the cap metal fitting 11b and the thickness of the metal bellows 10 is seen with respect to the conventional cutting of the plate and the press work of the cap metal fitting 11b of the present invention, FIG. As shown in the figure, it was confirmed that the mark “◯” indicates good welding, the mark “Δ” indicates slightly good welding, and the mark “×” indicates poor welding.
According to this experiment, it can be understood that the welding also affects the sag R and T / t caused by pressing.
[0026]
Further, since the seal material 11c is attached to the cap member 11b of the metal bellows 10 by the pressing of the presser piece 11e which is a mechanical fixing means, the seal material 11c is deteriorated and deteriorated by heat treatment after welding, and the welding is performed. Local damage due to sparks can be prevented.
[0027]
7 and 8 show another embodiment of the present invention, FIG. 7 is a sectional view thereof, and FIG. 8 is an enlarged sectional view of an essential part thereof.
This accumulator includes a hollow container 21 having a bottom portion, and has a plug hole 22 at the center of the bottom portion, and a gas plug 23 is attached to the plug hole 22. In addition, a closing member 25 having a circulation port 24 formed through the center thereof is hermetically attached to the open end of the container 21 by welding.
[0028]
The closing member 25 is integrally provided with a mounting flange 27 having a mounting hole 26 on the outer peripheral portion. Further, the closing member 25 integrally has a cylindrical portion (not indicated ) protruding in the center in the container 21, and the inside of the cylindrical portion is the flow port 24. A ring-shaped bellows base 30 is fixed to the outer periphery of the base portion of the cylindrical portion via an O-ring 29.
[0029]
In addition, one end of a metal bellows 31 is hermetically attached to the bellows base 30 by welding or the like so as to cover the outer periphery of the cylindrical portion with a constant gap. A cap is attached to the other end of the metal bellows 31. A member 32 is attached.
[0030]
The cap member 32 is configured by attaching a plate 32a to the other end of the metal bellows 31 by welding and attaching a seal material attaching member 32d having a seal material 32c bonded to the plate 32a. Specifically, in this example, a convex A is formed at the center of a plate 32a fixed to the other end of the metal bellows 31 by welding, and the plate 32a is attached to the sealing material mounting member 32d to which the sealing material 32c is bonded. A concave portion B corresponding to the convex type A is formed, and the concave portion B is attached by fitting the concave portion B to the convex type A of the plate 32a.
The formation of the convex mold A and the concave section B may be reversed. That is, a concave shape may be formed on the plate 32a, and a convex portion may be formed on the sealing material mounting member 32d to which the sealing material 32c is bonded. The sealing material 32c is disposed so as to face and separate from the inner end of the flow port 24.
A bellows guide 32b that is in sliding contact with the inner wall surface of the container 1 is provided on the outer periphery of the plate 32a.
[0031]
A region sandwiched between the plate 32a and the bottom of the container 21 is a gas chamber G of an inert gas such as N ₂ gas, and an inner region surrounded by the metal bellows 31 is a liquid communicating with the flow port 24. It is set as the room L.
[0032]
Therefore, in the metal bellows accumulator having such a configuration, the flow port 24 is connected so as to communicate with the hydraulic circuit, and the hydraulic pressure of the hydraulic circuit can be taken into the liquid chamber L in the container 21 through the flow port 24.
[0033]
For this reason, when the sealing material 32c of the cap member 32 is pressed according to the hydraulic pressure fluctuation (pulsation) of the hydraulic circuit, a hydraulic pressure change of the hydraulic circuit is introduced into the liquid chamber L through the flow port 24. In response to the change, the metal bellows 31 expands or contracts, whereby the hydraulic pressure fluctuation is absorbed in the same manner as in the above-described embodiment.
[0034]
Even in this case, the groove processing of the plate as in the prior art can be omitted, and since the sealing material mounting member 32d having the sealing material 32c bonded to the plate 32a can be arbitrarily mounted by fitting, this mounting can be performed by welding work or It becomes possible to carry out after the low temperature heat treatment after welding, and quality deterioration and damage due to heat of the sealing material 32c can be completely avoided.
[0035]
Further, since both the metal bellows 31 and the thin plate 32a obtained by punching can be welded by abutting a thin plate material at the sag portion of the periphery of the plate 32a, the welding accuracy and welding strength can be made sufficient. .
[0036]
【The invention's effect】
As described above in detail, according to the first aspect of the present invention, the other end of the metal bellows in the metal bellows accumulator is closed by the cap member, and the plate is fixed to the other end of the metal bellows by welding. Since the seal mounting member with the seal material bonded to the plate or the seal material with the core material is attached by mechanical fixing means, the metal bellows can be reliably and easily welded to the plate and welded. It is possible to prevent deterioration or deterioration of the sealing material due to subsequent heat treatment and damage to the sealing material during cutting of the groove of the welded portion, or local damage due to sparks during welding or the like.
In addition, the cutting of the groove of the welded portion is unnecessary, and a jig for preventing local deterioration of the sealing material due to welding heat is also unnecessary, so that the assembly efficiency is improved.
[0037]
Further, according to the engagement Ru invention in claim 1, wherein the mechanical fixing means plate to form a Totsugata or concave, and the plate in the sealing material for interior and bonded sealing member mounting member or core material sealant Since the concave portion or convex portion corresponding to the convex shape or concave shape is formed, and this convex shape or concave shape and the concave portion or convex portion corresponding thereto are fixed to each other, it is possible to reliably and easily weld the metal bellows to the plate. In addition, the sealing material can be easily attached to the plate. In addition, it is possible to prevent alteration and deterioration of the sealing material due to heat treatment after welding and damage to the sealing material during cutting of the groove of the welded portion, or local damage due to sparks during welding or the like .
[0038]
Further, according to the engagement Ru invention in claim 2, in addition to the same effects as described in paragraph [0036] in the invention according to the claim 1, said mechanical fixing means, fixing a cap fitting to the plate A plurality of presser pieces projecting from the outer periphery of the cap metal fitting, a sealing material mounting member with a sealing material bonded thereto or a sealing material containing a core material is overlaid on the cap metal fitting, and the presser piece is bent and fixed by pressing. As a result, the metal bellows can be reliably and easily welded to the plate, and the sealing material can be easily attached to the plate. Further, deterioration of the sealing material by heat treatment after welding, damage to the GMA cutting definitive during processing sealant deterioration and welds, or local damage due sparks during welding can be prevented.
[0039]
Furthermore, according to the engagement Ru invention in claim 2, since a plurality of guide pieces in sliding contact with the vessel wall to the outer periphery of the cap fitting are projected, the movement of the cap member caused by the expansion and contraction of the metal bellows is performed smoothly .
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing an embodiment of the present invention. FIG. 2 is an enlarged cross-sectional view showing a main part of the embodiment of the present invention.
FIG. 3 is a plan view showing a cap member.
FIG. 4 is an enlarged partial view showing a welded state between a plate and a metal bellows.
FIG. 5 is a chart showing a result of determining whether or not welding is good in a relationship between a plate thickness T of a plate and a plate thickness t of a bellows.
FIG. 6 is an enlarged partial view showing another bent state of the pressing piece of the plate.
FIG. 7 is a cross-sectional view showing another embodiment of the present invention.
FIG. 8 is an enlarged cross-sectional view showing a main part of another embodiment of the present invention.
FIG. 9 is a cross-sectional view showing a conventional example.
FIG. 10 is a partially enlarged sectional view of a conventional example.
FIG. 11 is an enlarged partial view showing a welded state between a cap member and a bellows of a conventional example.
[Explanation of symbols]
1, 21 Container 2, 24 Flow port 8, 22 Gas filling port 10, 31 Metal bellows 11, 32 Cap member 11a, 32a Plate 11c, 32c Seal material 11d Core material 32d Seal material mounting member

Claims (2)

A container, a metal bellows that is sealed and accommodated in one end in the container, and that can be expanded and contracted in the axial direction of the container that separates the container into a liquid chamber and a gas chamber, and the other end of the metal bellows is closed. A cap member that communicates with the liquid chamber and is opposed to the cap member, and a circulation port through which the liquid in the liquid chamber enters and exits as the bellows expands and contracts. A metal bellows accumulator constituting a self-sealing means for closing the flow port in a state where the metal bellows is stroked more than a predetermined stroke,
In the cap member, a plate is fixed to the other end of the metal bellows by welding, and a sealing material attaching member bonded with a sealing material or a sealing material having a core material is attached to the plate by mechanical fixing means. and,
The mechanical fixing means has a concave or convex shape corresponding to the convex or concave shape of the plate in a sealing material having a convex or concave shape formed on the plate, and a sealing material attaching member or a core material to which the sealing material is bonded. A metal bellows accumulator characterized in that a convex part or concave part and a concave part or convex part corresponding to the convex part or concave part are fixed to each other . A container, a metal bellows that is sealed and accommodated in one end in the container, and that can be expanded and contracted in the axial direction of the container that separates the container into a liquid chamber and a gas chamber, and the other end of the metal bellows is closed. A cap member that communicates with the liquid chamber and is opposed to the cap member, and a circulation port through which the liquid in the liquid chamber enters and exits as the bellows expands and contracts. A metal bellows accumulator constituting a self-sealing means for closing the flow port in a state where the metal bellows is stroked more than a predetermined stroke,
In the cap member, a plate is fixed to the other end of the metal bellows by welding, and a sealing material attaching member bonded with a sealing material or a sealing material having a core material is attached to the plate by mechanical fixing means. And
In the mechanical fixing means, a cap member is fixed to a plate, and a plurality of presser pieces and guide pieces that are in sliding contact with the inner wall surface of the container are alternately projected on the outer periphery of the cap member, and a sealing member to which a sealing member is bonded sealing material interior attachment member or core material, wherein the to Rume Tal bellows accumulator that said pressing piece is superposed on the cap fitting is being bent pressed and fixed.

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