JPH08159102A - Accumulator - Google Patents

Abstract

PURPOSE: To form a shell into thin plate thickness, to form an accumulator into small size and further to form a connecting part between the shell and an end cover into a simple structure by interposing with a fitting part and calking part of the shell a bladder mounting part so as to be in adhesion to a seating part of the end cover. CONSTITUTION: A shell 3, in plate shape of almost equal thickness, is formed into bottomed cylindrical shape. The shell 3 has a cylinder part 17, to form its opening side into a fitting part 1 having a tapered part 25 and a cylindrical supporting part 27. An opening side of the fitting part is formed into a calking part 2 bent to bee engaged with a stepped part 5 of an end cover 7. In a manner of interposing the end cover 7 by the calking part 2 and the tapered part 25, both the parts are secured, In one end of a large diametric surface 4a in a seating part 4, a stop part 12 is provided, and it is formed in an L-shaped section, to have a stop surface 23 in one end of a peripheral surface, also to have a small protrusion 22 in the other end.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION This invention relates to small accumulators. In particular, it relates to an accumulator used for water supply and the like.

[0002]

2. Description of the Related Art As a conventional example of the present invention, there is an accumulator shown in FIG. FIG. 9 is a half sectional view of this accumulator. In FIG. 9, 30 is an oil accumulator. Accumulator 30 is shell 32
Accumulator chamber 36 surrounded by the end cover 34 and
A resin bellows 38 is mounted therein so as to be expandable and contractible. By mounting the resin bellows 38 in the accumulator chamber 36, the accumulator chamber 36 is partitioned into a liquid chamber 40 and a gas chamber 42. Tapered portion 38 of resin bellows 38
The a is sandwiched between the joints of the tapered surfaces of the shell 32 and the end cover 34, and is sealed by attaching O-rings 47 to the O-ring grooves 45 and 46 on the tapered surfaces. 40 is sealed.
To join the end cover 34 to the shell 32,
The open end 32a of the shell 32 may be caulked.
In addition, at the same time as reliably sealing the accumulator chamber 36, in order to prevent water from entering from the outside, the shell 3
A square ring 44 is interposed at the joint between the 2 and the end cover 34.

The end cover 34 has a protrusion 3 in the liquid chamber.
4a is formed, and the tip thereof serves as a stopper surface to regulate the minimum compression position of the resin bellows 38. Further, the resin bellows 38 is provided on the end cover 34.
An oil port 39 that communicates with a liquid chamber 40 formed inside is formed. On the other hand, at the top of the shell 32, a gas charging port 37 communicating with a gas chamber 42 formed outside the resin bellows 38 is formed. A plug 41 for sealing the inside of the gas chamber 42 is detachably attached to the gas charging port 37.

A gas having a predetermined pressure (for example, nitrogen gas) is sealed in the gas chamber 42 through the gas charging port 37, and the liquid chamber 40 is passed through an oil port 39 formed in the end cover 34 and a liquid pipe (not shown). Alternatively, when communicating with a fluid device system such as a fluid device, a pressure difference between an internal liquid chamber 40 and an external gas chamber 42 acts on the resin bellows 38, and in a direction to mitigate the pressure fluctuation of the fluid device system,
The resin bellows 38 expands and contracts in the axial direction.
As a result, the pressure fluctuation of the fluid device system can be absorbed.

[0005]

The accumulator 30 constructed as described above has a shell formed by fitting the tapered outer surface 31 of the end cover 34, the tapered inner surface 35a of the shell 32 and the tapered portion 38a of the resin bellows 38. Three
The two, the bellows 38, and the end cover 34 can be automatically centered and assembled as a single unit, making it extremely easy to assemble.

However, in order to provide the taper inner surface 35a of the shell 32, the mounting portion 35 for forming the taper inner surface 35a must be thickened by the radial width of the taper surface. Further, since the O-ring grooves 45 and 46 are provided, the thickness is further increased accordingly. Also, since two O-ring grooves are provided in the axial direction, the length is also increased in the axial direction. Furthermore, since the square ring 44 must be provided in order to prevent water or the like from entering between the caulking members from the outside at the same time as flowing out from the inside, the outer diameter of the end cover 34 becomes larger.

As a result, the shell 32 and the end cover 34
Has a large diameter and forms a large diameter portion projecting from the cylindrical portion 32b of the shell 32, which is a problem in mounting the accumulator (however, it does not cause a problem in an oil device). .

Further, since the open end portion 32a of the shell 32 has to be thinned to be caulked, the processing cost for thinning the shell 32 becomes high.

Further, since the cylindrical portion 32b of the shell 32 must be chucked on a lathe or the like for cutting the caulked portion, the cylindrical portion 32b must be made thick, and in addition to the above-mentioned large-sized formation, It has the drawback of being heavy.

The accumulator of the present invention has been made in view of the problems of the prior art as described above, and its technical problem is to reduce the thickness of the shell to reduce the size of the accumulator as a whole and to reduce the size of the shell. The purpose is to make the joint of the end cover and the end cover a simple structure and to ensure the tightness of the joint.

[0011]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned technical problem, and the technical means is constituted as follows.

That is, a shell made of a plate-like wall having a mounting caulking portion at the end of the fitting portion, a seating portion that presses the fitting portion of the shell in a tapered shape, and engages with the caulking portion. A vacant chamber having a stepped portion and an end cover for a liquid port that forms an empty space with the shell, and a mounting portion that is press-contacted between the fitting portion of the shell and the seating portion of the end cover. A bladder made of a resin material that divides the gas chamber into a gas chamber and a liquid chamber. The end cover has an O-ring locking portion on the step side of the seating portion, and the locking portion is made of a rubber-like elastic material. The O-ring is arranged so that the end surface of the bladder on the mounting portion side is in pressure contact with the O-ring together with the locking portion.

Further, in the present invention, a small projection is provided at the boundary between the engaging portion of the end cover and the seating portion.

[0014]

[Function] The bladder mounting portion is press-fitted into the seating portion of the end cover, and the crimping portion is crimped while the shell fitting portion is press-fitted into the mounting portion so that the end surface of the bladder compresses the O-ring. Join in a simple shape. Then, the O-ring is stopped by the engaging portion of the end plate by its pressure contact, and then elastically deformed to improve the sealing ability,
This assembly is extremely easy.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment according to the present invention will be described below with reference to the drawings.

FIG. 1 is a half sectional view of an accumulator according to an embodiment of the present invention.

In FIG. 1, 3 is a shell. The shell 3 has a plate shape having substantially the same thickness and is formed in a bottomed cylindrical shape. The shell 3 has a tubular portion 17, and the opening side thereof is formed into a fitting portion 1 having a tapered portion 25 and a circumferential support portion 27. Further, the opening side of the fitting portion 1 is formed with a caulking portion 2 which is bent and engaged with the step portion 5 of the end cover 7. Then, the caulking portion 2 and the taper portion 25 sandwich the end cover 7 so that they are fixed to each other.

The shell 3 is made of iron, stainless steel,
Copper and aluminum plate materials are also suitable. In particular, stainless steel and copper are preferable in terms of workability.

The end cover 7 has an inflow hole 19 in the center thereof, and the central projection of the end cover 7 serves as a stopper 15 when the bladder 11 contracts. Further, the outer peripheral surface has a tapered surface 25a.
And a large diameter surface 4a forming a peripheral surface parallel to the large diameter side of the tapered surface 25a. The large diameter surface 4a is provided as needed. An O-ring groove 24 is formed on the tapered surface 25a.

A locking portion 12 is provided at one end of the large-diameter surface 4a of the seating portion 4. The locking portion 12 has an L-shaped cross section, and a locking surface 23 is provided at one end of the peripheral surface. In addition to having the small projection 22 at the other end. The small protrusion 22 corresponds to an example of a preferable aspect. As an example without the small protrusion 22, the engaging portion 1 is connected to one large diameter end of the tapered surface 25a.
2 are provided.

A rubber-like O-ring 18 is mounted in the above-mentioned O-ring groove 24 so that the liquid chamber 10 is completely sealed. Even if this O-ring is not provided, the gas chamber 9 and the liquid chamber 10 are completely sealed by the pressure bonding of the mounting portion 8 of the bladder 11 and the close contact of the seal ring 13.
In addition, FIG. 1B is an enlarged view of a main part viewed from an arrow A of FIG. 1A (related configuration of the seating portion of the end cover).

The bladder 11 has a tubular portion formed in a bellows shape, and has an overall bag shape. The open end has an end face 14, and the end face 14 is arranged so as to form a seal ring groove 21 between the end face 14 and the locking portion 12 of the end cover 7. Further, the mounting portion 8 is provided on the opening side. The mounting portion 8 is formed so as to press-fit into the seating portion 4 of the end cover 7.

A thermoplastic resin is used as the material of the bladder 11. This is to make it gas impermeable. Particularly when applied to drinking water piping, it is preferable to use ethylene vinyl alcohol or the like, which does not affect the human body.
The bladder 11 may be manufactured by blow molding, injection molding, compression molding, or the like.

Further, the bladder 11 may have a three-layer structure as shown in FIG. 6 for the purpose of improving gas impermeability. For example, a soft relaxation layer 29 made of polypropylene or polyacid may be formed on the front and back of the ethylene vinyl alcohol gas barrier layer 28 to form a multilayer structure. The gas barrier layer 28 exhibits gas impermeability to block gas permeation through the gas chamber 9. At the same time, the soft relaxation layer 29 prevents the liquid in the liquid chamber 10 from permeating and prevents the gas barrier layer from being deteriorated in function by the liquid. With this structure, the hard gas barrier layer 28 can be made thin, and the entire structure is excellent in flexibility.

As shown in FIG. 5, the end surface of the gas barrier layer 28 is embedded in the soft relaxation layer 29 to enhance the sealing effect, and as shown in FIG. A mode in which the seal effect is enhanced by elastically deforming is exemplified.

The mounting portion 8 of the bladder 11 has an end cover 7
Is pressed and sandwiched between the seating portion 4 and the fitting portion 1 of the shell 3 to seal the gas chamber 9 and the liquid chamber 10, and the end surface 14 of the bladder 11 crimps the seal ring 13 to form a double layer. It is sealed to. Then, the bladder 11 hermetically partitions the accumulator chamber 6 formed between the inner peripheral surface of the shell 3 and the end cover 7 into a gas chamber 9 and a liquid chamber 10.

FIG. 4 is a sectional view showing a state in which the mounting portion 8 of the bladder 11 and the seating portion 4 of the end cover 7 are temporarily fitted.

In FIG. 4, the locking portion 1 of the end cover 7
The seal ring 13 is fitted to the second portion 2, and then the mounting portion 8 of the bladder 11 is fitted to the seat portion 4. And the seal ring 1
3 and the end surface 14 of the bladder 11 are in a state with a gap of A dimension. Note that the names and configurations of the reference numerals are the same as in FIG.

Next, from the state shown in FIG. 4 to the state shown in FIG. 5, the fitting portion 1 of the shell 3 is fitted into the mounting portion 8 of the bladder 11 so that the shell 3 covers the bladder 11. Meanwhile, it is press-fitted downward in the drawing. Then, when the shell is press-fitted until the end surface 14 of the bladder 11 is pressed against the seal ring 13, the mounting portion 8 of the bladder 11 is pressed by the tapered surface 25a of the end cover 7 and the tapered surface 25a of the shell 3. At this time, since the caulking portion 2 of the shell 3 is set to be lower than the step portion 5 of the end cover 7, by caulking the caulking portion 2 to the step portion 5, the end cover 7 is tapered. The shell 3 and the bladder 11 are fixed to the end cover 7 by tightening the space between the shape portion 25 and the step portion 5.

FIG. 6 is a cross-sectional view of essential parts showing the mounting state of the mounting portion 8 of the bladder 11 and the fitting portion of the shell 3 to the seating portion 4 of the end cover 7. FIG. 6 is a state diagram in which the caulking is completed after the assembling steps shown in FIGS. 4 and 5 are passed. The overall configuration of the accumulator 20 shown in FIG. 6 is as shown in FIG. The names and configurations of the reference numerals are substantially the same as those described with reference to FIG.

FIG. 7 is a partial sectional view showing the structure of the outer peripheral surface of the end cover 7.

In FIG. 7, the seating portion 4 is formed with a tapered surface 25a, and the locking portion 12 is formed in the L-shaped cross section from the large diameter surface of the tapered surface 25a. The locking portion 12 has a locking surface 23 formed on the lower side in the drawing, and a small projection 22 on the opposite side. This small protrusion 22
Height H is set to 0 <H <0.80 W (W is the seal ring wire diameter). The φD dimension is the same as the inner diameter of the seal ring 13. Further, on the lower side of the locking surface 23 shown in the figure, a step portion 5 is formed at the tip of which the corner is chamfered to have an R radius. The embodiment shown in FIG. 7 has a structure in which the seal ring is excellent in hermeticity.

FIG. 8 is a sectional view of another embodiment of the same main part as the end cover 7 shown in FIG.

In FIG. 8, the seating portion 4 of the end cover 7
The engaging portion 12 and the engaging portion 12 have a shape in which the peripheral surface is formed as a tapered surface 25a without providing a small protrusion, and the engaging surface 23 is directly formed on the large diameter of the tapered surface 25a. Other parts are substantially the same as the configuration shown in FIG. 7. In this case, the processing of the end cover 7 becomes extremely easy. Especially suitable for plastic working.

The end cover 7 can be made of synthetic resin material in addition to iron, stainless steel, aluminum, copper material. Although the manufacturing can be performed by cutting, the end cover 7 of the present invention has a simple structure, so that the cost can be greatly reduced by manufacturing by plastic working. The present invention is characterized by this point. If a resin material is used, it can be manufactured by injection molding.

FIG. 2 is a sectional view of another embodiment of the accumulator according to the present invention. In FIG. 2, reference numerals and symbols have substantially the same names and configurations as those shown in FIG. The difference between the two is that the tapered surface 25a of the seating portion 4 of the end cover 7 is formed to have a small diameter downward in the drawing. The attachment portion 8 of the bladder 11 is formed to be slightly thicker toward the opening side. The overall mounting structure is substantially the same as that described with reference to FIG. 1, and therefore description thereof will be omitted. In this aspect, the outer diameter of the accumulator can be made small, and the accumulator can be configured to have excellent pulsation absorption capacity and pressure accumulation capacity.

FIG. 3 is a sectional view of an accumulator according to still another embodiment of the present invention. The overall structure of this accumulator is substantially the same as that in FIG. The difference is that the tapered surface 25a of the seating portion 4 of the end cover 7 is formed as a tapered surface slightly protruding in an arc shape. Therefore, the tapered surface 25a of the fitting surface of the shell 3 is also formed correspondingly. In this mode, joining of the mounting portion 8 side of the bladder and the stopper 15 side of the end cover 7 is preferable, the axial length of the accumulator can be shortened, and the pulsation absorbing ability is improved.

The embodiment of the accumulator shown in FIGS. 2 and 3 does not have the O-ring groove 24 and the O-ring 18 fitted in the O-ring groove 24 in the seat 4, but it is necessary. Accordingly, a good result is also obtained in the mode in which the O-ring 18 is mounted in the O-ring groove 24.

Seating portion 4 in the end cover 7 of the present invention
The angle of the tapered surface 25a with respect to the axial direction is 10 ° or less, as shown in FIGS. Then, the tapered surface 25a may be an arcuate surface as shown in FIG. Further, as shown in FIG. 2, it may be formed in a tapered surface inward. Further, the tapered surface 25 of the seating portion 4
There are a large diameter surface 4a provided on the large diameter side of a as shown in FIGS. 5 and 6, and a large diameter surface 4a not provided as shown in FIGS. This may be provided if necessary.

The locking portion 12 of the end cover 7 is shown in FIG.
There are those in which the small projection 22 (that is, the deformed groove) is provided, and those in which the tapered surface 25 reaches the locking surface 23 as shown in FIG. Further, in FIG. 7, there is a case where the small projection 22 is not provided, that is, a case where the fitting surface D dimension of the seal ring 13 has only a peripheral surface parallel to the axis. Further, the radial dimension B of the locking surface 23 is formed to be equal to or less than the wall thickness of the mounting portion 8 of the bladder 11.

The inner peripheral surface of the fitting portion 1 of the shell 3 is preferably similar to the outer peripheral surface of the seating portion 4 of the end cover 7 when the thickness of the shell 3 is large. When the shell 3 has a small wall thickness, it may be press-fitted into the seat 4 of the end cover 7 so as to be deformed in correspondence with the straight peripheral surface. This idea is also applied to the shape of the mounting portion 8 of the bladder 11.

[0042]

In the accumulator according to the first aspect of the present invention, the end cover has the tapered surface and the step portion, and the locking portion for the seal ring is provided between the tapered surface and the step portion. Has been. Then, the bladder is clamped by the fitting portion and the caulking portion of the shell so that the mounting portion of the bladder is pressed against the seating portion of the end cover. At this time, the seal ring is pressed against the bladder by the same action as that of the bladder mounting portion. Therefore, a) Since the bladder is made of a resin material, the end cover, which is shaped so as to hold the fitting portion and the caulking portion of the shell, firmly presses the gas chamber and the liquid chamber. Has the effect of sealing. B) At the same time, the seal ring strongly presses the end ring with the locking surface of the locking part and the end surface that is elastically deformed by the crimping of the mounting part of the bladder to make the gas chamber and the gas chamber double. Has the effect of sealing. On the contrary, the inclined tip of the end surface of the mounting portion is pressed against the inner peripheral surface of the fitting portion of the shell and acts like a seal lip to exert a sealing effect. Therefore, as in the conventional example, a large number of O
The sealing effect is exhibited without providing a ring, and the effect of reducing the manufacturing cost as well as the size of the mounting portion is achieved. C) Since the bladder is made of a resin material and is not elastically deformed significantly, the tapered surface of the end cover can have an extremely small inclination angle. Therefore, also in this respect, the radial expansion of the fitting portion of the shell is prevented. Further, since the locking surface of the locking portion does not have a diameter larger than the wall thickness of the mounting portion of the bladder, in this respect also, the expansion of the fitting portion of the shell in the radial direction is prevented. Moreover, since the shell is plate-shaped, it is not thick enough to be machined as in the conventional example. Also in this respect, radial expansion is prevented. Therefore, since the accumulator of the present invention does not have a component having a large diameter, the accumulator does not become large in size, and the gas chamber can be expanded, which can contribute to the improvement of the pulsation absorption capacity. Furthermore, since the shape of the end cover enables plastic working, the production cost can be reduced. Therefore, it has an excellent effect as an accumulator for household water supply.

[Brief description of drawings]

FIG. 1 is a half sectional view of an accumulator according to an embodiment of the present invention.

FIG. 2 is a sectional view of an accumulator according to another embodiment of the present invention.

FIG. 3 is a half sectional view of an accumulator according to still another embodiment of the present invention.

FIG. 4 is a cross-sectional view of a pre-assembly step in which a bladder is temporarily attached to the end cover of the accumulator according to the embodiment of the present invention.

5 is a sectional view of an essential part in the middle of a step of press-fitting a shell into the bladder shown in FIG. 4 according to an embodiment of the present invention.

FIG. 6 is a cross-sectional view of an essential part of a state where the caulking portion is crimped from the state shown in FIG. 5 according to the embodiment of the present invention.

FIG. 7 is a cross-sectional view of essential parts of an end cover of an example of the accumulator according to the embodiment of the present invention.

FIG. 8 is a sectional view of a main part of an end cover of another example of the accumulator according to the embodiment of the present invention.

FIG. 9 is a half cross-sectional view of a conventional accumulator.

[Explanation of symbols]

 1 ... Fitting part 2 ... Caulking part 3, 32, ... Shell 4 ... Seating part 5 ... Step part 6, 36 ... Accumulator chamber 7, 34 ... End cover 8, 35 ... Mounting part 9 , 42 ... gas chamber 10, 40 ... liquid chamber 11 ... bladder 12 ... locking part 13 ... seal ring 14 ... end face 15 ... stopper 16 ... bellows part 17 ... tubular part 18, 47 ... … O-ring 19 …… Inflow hole 20,30 …… Accumulator 21 …… Seal ring essential groove 22 …… Small protrusion 23 …… Locking surface 24 …… O-ring groove 25 …… Tapered part 25a …… Tapered Surface 27 ... Support portion 28 ... Gas barrier layer 29 ... Soft relaxation layer 31 ... Tapered outer surface 32a ... Opening end portion 32b ... Cylindrical portion 34a ... Projection portion 35a ... Tapered inner surface 37 ... Gas inlet port 38 …… Bellows 38a …… Te Pas portion 39 ...... oil port 41 ...... gas plug 44 ...... angle rings 45, 46 ...... O-ring groove B ...... seal ring width D ...... seal ring inner diameter

Claims (2)

[Claims] 1. A seating portion (4) having a tapered surface (25) on its outer periphery, a step portion (5) for caulking at one end of the seating portion (4), and the seating portion (4). A liquid port end cover (7) having a stepped locking portion (12) for a seal ring between the stepped portion (5) and the seating portion (4).
And a sealing ring groove (21) is formed between the end of the mounting portion (8) and the locking portion (12) of the end cover (7). A bag-shaped resin-made bladder (11) having an end surface (14) and forming a liquid chamber (10) between the end cover (7) and an attachment portion (8) of the bladder (11). The end cover (7)
Of the end cover (7) having a fitting portion (1) for crimping with the seating portion (4) of the end cover (7) and bending at the opening end side of the fitting portion (1). The end cover (7) is provided with a bottomed cylindrical shell (3) having a caulking portion (2) for caulking engagement and forming a gas chamber (9) with the bladder (11). An accumulator characterized in that a locking ring made of a rubber-like elastic material is attached to the locking portion (12) in pressure contact with the end surface (14) of the bladder (11). 2. A locking portion (12) of the end cover (7).
The accumulator according to claim 1, further comprising a small protrusion (22) at a boundary between the seat and the seat (4).