JP2001020901A - Accumulator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To exhibit a good pulse pressure absorbing effect or a damping effect by providing a chamber and a throttle mechanism for absorbing pulsation generated at a system side for connecting an accumulator. SOLUTION: In an accumulator, when pressure of a system side is extremely reduced during operation, a bellows is extended, an end member 7 abuts on an end surface part 3b and the like of a shell 3, and then it is stopped, a throttle clearance 21 of a throttle mechanism 20 is formed between a tip surface of a throttle forming wall 19 and an end surface 7a of the end member 7, and also a chamber 22 is formed on an outer peripheral side of the throttle clearance 21 to communicate therewith. When a pressure fluid flows into the accumulator in association with pulsation of the system side, pulsation energy is converted into loss energy by contracted flow and throttle when the throttle clearance 21 is propagated by the fluid or its pressure, and it attains the chamber 22 to consume as dynamic pressure loss. It is thus possible to effectively damp pulsation of the system side by a damping action.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an accumulator used as a pressure accumulator or a pulse pressure absorbing device.

[0002]

2. Description of the Related Art Conventionally, an accumulator 5 shown in FIG.
1 is known and is configured as follows.

[0003] First, a housing 52 is provided by welding and fixing lid members 54 and 55 to both ends of a cylindrical shell 53, and an operation having a bellows 57 and an end member 58 inside the housing 52. The member 56 is housed. One end of the bellows 57 is connected to one lid member 5.
4 and the other end is fixed to the end member 58. Therefore, the bellows 57 and the end member 5
8 is divided into a pressure sealing chamber (gas chamber) 59 inside and a pressure inflow chamber (liquid chamber) 60 outside.

[0004] One lid member 54 on the left side of the figure is provided with a pressure injection port 61 for injecting gas into the pressure sealing chamber 59, and the pressure injection port 61 is used to close the injection port 61. Is attached. Therefore, the plug member 62 is removed and the sealing chamber 59 is inserted through the injection port 61.
After the injection, a gas at a predetermined pressure is sealed in the sealing chamber 59 by closing the injection port 61 with a plug member 62.

A mounting portion 63 having a screw portion 64 for connecting the accumulator 51 to a pressure pipe or the like (not shown) is provided on the other lid member 55 on the right side in the drawing. A fluid inlet 65 for introducing the system side pressure fluid into the pressure inlet chamber 60 is provided in the section 63.
Is provided. Therefore, the actuator 51
Is connected to the system side at the mounting portion 63, and the pressure on the system side is introduced from the inflow port 65 into the inflow chamber 60.

The accumulator 51 having the above configuration is
For example, as a pulse pressure absorbing device, the pressure pulsation generated on the system side is absorbed by balancing the sealed gas pressure sealed in the pressure sealing chamber 59 with the fluid pressure introduced into the pressure inflow chamber 60. During operation, the pressure inflow chamber 6
If the pressure in the system 0, that is, the pressure on the system side, is extremely reduced, the bellows 57 will extend completely inside the housing 52, so that the pulsation generated on the system side cannot be absorbed in a low pressure state lower than that. There is.

[0007]

SUMMARY OF THE INVENTION In view of the above, the present invention has been made to reduce the pulsation generated on the system side even when the internal operating members such as the bellows do not operate in response to the pressure fluctuation on the system side. It is an object of the present invention to provide an accumulator that can absorb and thereby exhibit an excellent pulse pressure absorption effect or a pulse pressure attenuation effect, and an internal operating member such as a bellows in response to a pressure fluctuation on the system side. Even when is operating, the pulsation generated on the system side can be absorbed by the separate throttling mechanism and the chamber at the start of the operation, thereby exhibiting an excellent pulse pressure absorbing effect or pulse pressure damping effect. It is an object of the present invention to provide an accumulator that can perform the operation.

[0008]

In order to achieve the above object, an accumulator according to a first aspect of the present invention is provided with a throttle mechanism and a chamber for absorbing a pulsation generated on a system connecting the accumulator. It is assumed that.

According to a second aspect of the present invention, the accumulator according to the second aspect of the present invention includes a throttling mechanism and a chamber for absorbing a pulsation generated on the system side to which the accumulator is connected in a range from zero to a gas filling pressure. It is a feature.

According to a third aspect of the present invention, in the accumulator, an operating member including a bellows is disposed inside the housing to partition the inside of the housing into a pressure sealing chamber and a pressure inflow chamber. In an accumulator provided with a fluid inlet for introducing a fluid from a system side to an inflow chamber, the throttle forming wall and the operating member are provided when the operating member approaches a throttle forming wall provided around the fluid inlet. A diaphragm mechanism that forms a diaphragm gap between the diaphragm and the operating member when the operating member approaches the diaphragm forming wall, around the diaphragm forming wall and between the inner surface of the housing and the operating member. And a chamber.

When a pulsating fluid flows into the accumulator according to the present invention having the above-described structure, the pulsating energy is converted by the throttle mechanism into energy lost due to contraction and throttle, and a chamber is provided. As a result, the pulsation can be attenuated because it is used as a dynamic pressure loss.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 shows a cross section of an accumulator 1 according to the embodiment, and FIG. 2 shows a partially enlarged cross section showing an operation state thereof.

The accumulator 1 according to the embodiment is a metal bellows type accumulator, and is configured as follows.

First, a housing 2 is provided by welding and fixing a lid member (also referred to as an end cover or a gas end cover) 4 to the open end of a bottomed cylindrical shell 3. , An operating member 5 including a bellows 6 and an end member (also referred to as a bellows cap) 7 is accommodated. The bellows 6 has one end fixed to the lid member 4 and the other end fixed to the end member 7, so that the inside of the housing 2 is inside the bellows 6 and the end member 7 by the bellows 6 and the end member 7. And a pressure inflow chamber (also called a liquid chamber or fluid chamber) 9 on the outside. As the bellows 7, a metal bellows such as an electrodeposition bellows, a molded bellows, or a welding bellows is used, but a bellows of another material may be used depending on the specifications and use of the accumulator 1. Further, the end member 7 may be formed integrally with the bellows 6.

The cover member 4 constituting a part of the housing 2 is provided with a pressure injection port 10 for injecting a gas into the pressure sealing chamber 8. The pressure injection port 10 is provided with the pressure injection port 10. A plug member (also referred to as a gas plug) 11 for closing is attached. Therefore, by removing the plug member 11 and injecting a gas of a predetermined pressure from the injection port 10 into the sealing chamber 8, the injection port 10 is closed with the plug member 11 after the injection, so that the gas of the predetermined pressure is sealed in the sealing chamber 8. I do. As the type of gas to be filled, nitrogen gas, inert gas and the like are preferable.

A mounting portion 12 provided with a screw portion 13 for connecting the accumulator 1 to a pressure pipe or the like (not shown) on the end wall 3a of the shell 3 also constituting a part of the housing 2. The mounting portion 12 is provided with a fluid inlet (also referred to as a pressure inlet or a fluid passage) 14 for introducing a system side pressure fluid into the pressure inflow chamber 9. Therefore, the actuator 1 is connected to the system side at the mounting portion 12, and the pressure on the system side is introduced from the inflow port 14 into the inflow chamber 9.

An annular sliding member (also referred to as a vibration damping ring) 15 is mounted on the outer peripheral side of the other end of the bellows 6 fixed to the end member 7 or on the outer peripheral side of the end member 7. The sliding member 15 slides with its outer peripheral portion against the inner peripheral surface of the shell 3 during the expansion and contraction operation and when the end member 7 moves. Accordingly, the end member 7 moves in parallel with the inner peripheral surface of the shell 3 and the bellows 6 expands and contracts in parallel with the inner peripheral surface of the shell 3 by the sliding guide of the sliding member 15, whereby the end member 7 or The bellows 6 is prevented from biting against the inner peripheral surface of the shell 3. The sliding member 15 does not separate the pressure inflow chamber 9 into a space 9a on the outer peripheral side of the bellows 6 and a space 9b on the upper and lower sides of the end member 7 in the figure. A pressure communication unit (not shown) is provided.

A mounting portion 3c having a concave shape or a step shape is provided on the inner surface of the end wall portion 3a of the shell 3, that is, on the end surface portion 3b of the shell 3 and on the periphery of the opening of the pressure inlet 10. The seal 16, the holder 17, and the pipe 18 are mounted on the mounting portion 3c in order from the outer peripheral side.

First, when the accumulator 1 is used, when the pressure in the pressure inflow chamber 9, that is, the pressure on the system side is extremely reduced, the bellows 6 expands due to a pressure difference between the inside and outside of the accumulator 1, and is broken. In order to prevent this, the pressure is provided to maintain the pressure of the pressure inflow chamber 9 at a predetermined value or more, and the configuration is as follows.

That is, the seal 16 is formed as a lip seal formed of a predetermined rubber-like elastic material, and as shown in FIG.
An annular base 16a which is press-fitted in a non-adhesive manner to the
An annular seal lip (also referred to as an inner peripheral side seal lip or a first seal lip) that is in contact with the end surface of the base 16a on the end member 7 side so as to be able to come into contact with and separate from the end surface 7a of the end member 7.
16b is integrally formed. An annular recess 16c is formed on the outer peripheral side of the seal lip 16b,
An annular outer seal lip (also referred to as a second seal lip) 16d that is always in close contact with the inner surface of the mounting portion 3c is integrally formed on the outer periphery of the recess 16c.

As shown, the seal lip 16b
It is formed as an outwardly-sealing seal lip whose radial dimension increases radially outward from its base end to its distal end, and a pressure inflow that is a sealing fluid pressure when it comes into contact with the end face 7 a of the end member 7. It is pressed by the pressure in the chamber 9 and pressed against the end face 7a to come into close contact therewith. Therefore, this seal lip 1
6b has an outer peripheral surface serving as a pressure receiving surface. At the tip of the seal lip 16b, two annular seal projections 16e, 16f are provided concentrically, each of which has an annular shape.
In close contact with the end face 7a. This is because foreign matter in the fluid is caught between one of the seal protrusions 16e, 16f and the end face 7a of the end member 7, and the seal protrusions 16e, 16f
Even if the sealing property between the end face 7a and the sealing face is impaired, the other sealing projections 16e and 16f are in close contact with the end face 7a over the entire circumference to ensure the sealing property. By providing such a multilayer structure of the seal projections 16e and 16f, the sealing performance of the entire seal lip 16b is improved. Seal projection 1
The number of 6e and 16f formed is not limited to two, but may be three or more. Further, when the end member 7 moves and comes into contact with the end surface portion 3b of the shell 3 or another stopper (not shown) or the like, the seal lip 16b stops.
6e, 16f contact the end face 7a of the end member 7, that is, the sealing lip 16b does not act or stop as a stopper for stopping the moved end member 7 by itself. Have been.

The holder 17 disposed on the inner peripheral side of the seal 16 is formed in an annular shape from a rigid material such as metal or resin, and has a flat plate-like or serpentine flat portion 1.
7a and a cylindrical rising portion 1 integrally formed from the outer peripheral end of the flat portion 17a toward the end member 7 side.
7b, and is formed in an L-shaped or substantially L-shaped cross section.

At the inner peripheral end of the flat portion 17a, an annular stepped engaging portion 18 provided on the outer peripheral surface of the pipe 18 is provided.
The holder 17 is fixed to the shell 3 by inserting and fixing the pipe 18 to the fluid inlet 14 as described later. The rising portion 17b is disposed immediately inside the seal 16 and its front end is enlarged in a trumpet shape or a tapered shape. Therefore, the rising portion 17b prevents the seal 16 from coming off the mounting portion 3c. Holds this. The rising portion 17b also has a function of backing up the seal lip 16b of the seal 16. As shown in FIG. 2, when the end member 7 moves and comes into contact with the end surface portion 3b of the shell 3 or another stopper, as shown in FIG.
A gap is formed between the end member 7 and the end member 7.

The pipe 18 disposed on the inner peripheral side of the holder 17 is formed of a rigid material such as metal or resin into a cylindrical shape, and has a relatively small outer diameter inserted into the fluid inlet 14. The insertion portion 18b and the insertion portion 18
b has a rising portion 18c integrally formed on the end member 7 side and having a relatively large outer diameter, and the above-described annular step-like engagement is formed at the boundary between the insertion portion 18b and the rising portion 18c. A joint 18a is provided.

The insertion portion 18b is fixed to the shell 3 by being press-fitted into the fluid inlet 14;
As shown in FIG. 2, the insertion portion 18b is connected to the fluid inlet 14.
, The leading end (upper / lower end in the figure) of this insertion portion 18b may be fixed to the shell 3 by enlarging it in a trumpet shape or a tapered shape. In this case, the fluid inlet 14 A trumpet-shaped or tapered engagement portion 14a is provided in advance on a part of the inner surface of the.

As shown in FIG. 2, when the end member 7 moves and comes into contact with the end surface portion 3b of the shell 3 or another stopper, as shown in FIG.
A gap is formed between the end member 7 and the end member 7 so that the end member 7 is always kept out of contact with the end member 7. When the end member 7 of the operating member 5 approaches the diaphragm forming wall 19, the annular diaphragm gap 2 is formed between the diaphragm forming wall 19 and the front end surface and the end surface 7 a of the end member 7.
1 is provided. When the end member 7 of the operating member 5 approaches the squeezing wall 19, the end member 7 moves as described above and comes into contact with the end surface 3b of the shell 3 or another stopper, and stops. It is.

Similarly, when the end member 7 of the operating member 5 approaches the diaphragm forming wall 19, the diaphragm forming wall 1
An annular chamber chamber 22 is provided around the periphery of the housing 9. In the figure, the chamber chamber 22 is formed by the upper surface of the flat portion 17 a of the holder 17, which forms a part of the inner surface of the housing 2, and the cylindrical portion 17 b. The inner peripheral surface, the outer peripheral surface of the rising portion 18c of the pipe 18, the end surface 7a of the end member 7, and the seal lip 16b of the seal 16 are formed as a space.
Through the fluid inlet 14.

The accumulator 1 having the above-described structure, for example, as a pulse pressure absorbing device, changes the pressure pulsation generated on the system side by the pressure of the sealed gas in the pressure sealing chamber 8 and the fluid pressure introduced into the pressure inflow chamber 9. In particular, during operation, the pressure on the system side is extremely reduced, whereby the pressure inflow chamber 9 is reduced.
The pressure in the inside is extremely reduced, the bellows 6 expands, and the end member 7
Is stopped by contacting the end surface 3b of the shell 3 and other stoppers, etc., the aperture gap 21 of the aperture mechanism 20 is formed between the distal end face of the aperture forming wall 19 and the end face 7a of the end member 7 as described above. In addition, since the chamber chamber 22 connected to the throttle gap 21 is formed on the outer peripheral side of the throttle gap 21, the following operation and effect can be achieved.

That is, when pressure fluid accompanied by pulsation on the system side flows into the accumulator 1, when this fluid or its pressure passes or propagates through the throttle gap 21, the pulsation energy is reduced by the contraction / throttle loss. The energy is converted into energy and reaches the above-mentioned chamber chamber 22 to be used and consumed as a dynamic pressure loss. Therefore, pulsation on the system side can be effectively attenuated by such a damping action. The damping mechanism formed by the throttle gap 21 and the chamber 22 operates in a system pressure range from zero to a gas filling pressure.

[0031]

The present invention has the following effects.

That is, according to the above configuration, when a fluid accompanied by pulsation on the system side flows into the accumulator, the fluid or its pressure passes or propagates through the throttle gap of the throttle mechanism. Since the pulsation energy is converted to the energy lost due to the contraction / throttling and reaches the chamber, the pulsation energy is used as a dynamic pressure loss. Thus, the pulsation on the system side can be effectively attenuated by such a damping action. . According to the second aspect, the damping mechanism formed by the throttle gap and the chamber operates in a system pressure range from zero to a gas filling pressure. Therefore, even when the operating member such as the bellows does not operate in response to the pressure fluctuation on the system side, such as when the bellows is completely extended in the housing, the pulsation generated on the system side can be effectively absorbed. With
Even when the internal operating member such as the bellows operates according to the pressure fluctuation on the system side, the pulsation generated on the system side can be effectively absorbed by the separate throttle mechanism and the chamber at the start of the operation. . Therefore, an accumulator exhibiting an excellent pulse pressure absorbing effect or an excellent pulse pressure attenuation effect can be provided by such an action.

[Brief description of the drawings]

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

FIG. 2 is a partially enlarged sectional view showing an operation state of the accumulator.

FIG. 3 is a sectional view of an accumulator according to a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Accumulator 2 Housing 3 Shell 3a End wall part 3b End face part 3c Mounting part 4 Lid member 5 Operating member 6 Bellows 7 End member 7a End face 8 Pressure sealing chamber 9 Pressure inflow chamber 10 Pressure injection port 11 Plug member 12 Mounting part 13 Screw part Reference Signs List 14 Fluid inlet 14a, 18a Engaging part 15 Sliding member 16 Seal 16a Base 16b, 16d Seal lip 16c Depression 16e, 16f Seal projection 17 Holder 17a Flat part 17b, 18c Rising part 18 Pipe 18b Insertion part 19 Throttle forming wall 20 Throttle mechanism 21 Throttle gap 22 Chamber chamber

Claims (3)

[Claims] An accumulator comprising a throttle mechanism (20) and a chamber (22) for absorbing a pulsation generated in a system connecting the accumulator (1). 2. A throttle mechanism (20) and a chamber (22) for absorbing a pulsation generated on a system side to which the accumulator (1) is connected in a range of a system pressure from zero to a gas charging pressure. Accumulator. 3. An operating member (5) including a bellows (6) is arranged inside a housing (2), and the inside of the housing (2) is divided into a pressure sealing chamber (8) and a pressure inflow chamber (9). An accumulator (1) provided with a fluid inlet (14) for partitioning and introducing a fluid from the system side to the pressure inlet chamber (9) in the housing (2); Diaphragm forming wall (1)
An aperture mechanism (20) for forming an aperture gap (21) between the aperture forming wall (19) and the operating member (5) when the operating member (5) approaches 9); A chamber formed around the aperture forming wall (19) and between the inner surface of the housing (2) and the operating member (5) when the operating member (5) approaches the wall (19). An accumulator characterized by having a chamber (22).