JP2001124001A - Accumulator and manufacturing method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the accuracy in machining a cap member to seal the end face of the metal bellows of an accumulator and accuracy for mounting there for and a valve element to the metal bellows with a pimple structure. SOLUTION: The end face of the retractable metal bellows. which divides the inside of a pressure vessel into a liquid chamber connected to an external circuit and a gas chamber hermetically sealed with high pressure gas contained, and the opening of a flow passage communicated with the external circuit, are blockaded by a valve element. A recessed section is formed by drawing the center of the cap member of the accumulator to which the valve element is provided The method in which the external peripheral edge of the cap member is pressed or cut and the valve element is installed on the basis of the recessed section improves the accuracy more than that obtained by punching on the basis of the peripheral edge, and even if machining is made on the peripheral edge plural times, the alignment doesn't go wrong and the man hours required for manufacturing the accumulator are reduced. by eliminating the no cessit for changing bolding part of the cap member form one hand to the other in machining the cap member.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an accumulator using a metal bellows used for accumulating pressure and absorbing pulsation in a hydraulic device of a vehicle brake system and various industrial hydraulic systems, and a method of manufacturing the same. is there.

[0002]

2. Description of the Related Art As an accumulator used for a hydraulic device of a vehicle brake system or various industrial hydraulic systems, an extensible metal bellows having one end fixed inside a pressure vessel and the other end closed by a cap member. And a liquid chamber connected to an external circuit and a gas chamber in which high-pressure gas is sealed. In such an accumulator, when the hydraulic pressure transmitted from the external circuit is lower than the gas pressure sealed in the gas chamber, the metal bellows expands and contracts, and the valve element provided on the cap member is positioned on the periphery of the opening of the liquid chamber. The gas chamber is pressed against and tightly closed, and self-sealing is performed so that the pressure of the liquid chamber does not become lower than that of the gas chamber. Therefore, the accuracy with which the valve element is attached to the cap member is important for improving the sealing performance. on the other hand,
The edge of the metal bellows is joined to the periphery of the cap member. Therefore, the peripheral portion is processed so as to be easily joined. Then, in order to enhance the sealing between the gas chamber and the liquid chamber, it is necessary to increase the processing accuracy of the cap member and the positioning accuracy of both at the time of joining.

[0003]

However, the conventional cap member is formed into a substantially disk shape by punching, and the positioning of the above-mentioned processing and the like is performed by the peripheral edge thereof. Therefore, there is a limit in improving the accuracy. Further, when processing the peripheral edge of the cap member, first, the peripheral edge is positioned and partially cut, and the peripheral edge is cut and repositioned by the processed portion, so that the number of steps increases and the number of steps increases. There was a problem that the minute accuracy was reduced.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems in the prior art, and has been made in consideration of the processing accuracy of a cap member having a valve body for sealing and self-sealing an end surface of a metal bellows of an accumulator, and a valve body. An object of the present invention is to improve the mounting accuracy and the mounting accuracy to a metal bellows with a simple structure.

[0005]

SUMMARY OF THE INVENTION According to the present invention, there is provided, in accordance with the present invention, a pressure vessel having a liquid chamber connected to an external circuit and a gas chamber sealed with high-pressure gas. An opening of a flow passage having an extendable metal bellows having one end fixed to the pressure vessel and the other end closed by a cap member, and communicating with the external circuit through the cap member of the metal bellows. An accumulator provided with a valve element that closes the cap member, wherein the cap member has a concave portion formed by drawing at the center thereof, and an outer peripheral edge of the cap member is processed with reference to the concave portion, and An accumulator characterized in that the valve body is mounted with reference to the recess, and a pressure chamber received in a pressure vessel and a liquid chamber connected to an external circuit and having a high pressure. In order to separate the body from the sealed gas chamber, one end is fixed to the pressure vessel, and the other end has an extendable metal bellows closed by a cap member, and the external circuit is provided on the cap member of the metal bellows. A method for manufacturing an accumulator provided with a valve element that closes an opening of a flow path communicating with the accumulator, wherein a recess is formed by drawing at the center of the cap member, and an outer peripheral edge of the cap member is based on the recess. This is achieved by providing a method for manufacturing an accumulator, characterized in that the accumulator is processed with the concave portion as a reference. In particular, the inside of the metal bellows forms the liquid chamber,
The gas chamber may be formed between the pressure vessel and the metal bellows, and the valve body may be provided on a convex surface of the gas chamber opposite to the concave portion of the cap member.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of an accumulator to which the present invention is applied will be described below in detail.

FIG. 1 is a side sectional view of an accumulator to which the present invention is applied. The interior of the housing 1 as a pressure vessel is partitioned into a gas chamber 3 and a liquid chamber 4 by a metal bellows assembly 2 received therein. The metal bellows assembly 2 has a metal bellows 5 fixed at one end to the housing 1 and formed with a large number of folds so as to be able to expand and contract in the axial direction of the housing 1, and a cap member 6 attached to a free end of the metal bellows 5. And a valve body 7 made of an elastomer material such as rubber attached to the inside of the metal bellows 5 of the cap member 6. The liquid chamber 3 in the metal bellows 5 has an opening 8 provided in the housing 1.
a through the flow path 8 to communicate with the external circuit,
The compressed gas is sealed in the gas chamber 4 inside the metal bellows 5 and outside the metal bellows 5.

In such an accumulator, when the pressure in the flow path 8 is higher than the gas pressure sealed in the accumulator, the pressure in the flow path 8 and the pressure in the gas chamber 4 are the same. The metal bellows 5 expands until pressure is reached. In the process, the valve body 7 separates from the opening 8a, the liquid chamber 3 communicates with the flow path 8, and the pressure is accumulated by the contraction of the metal bellows 5. When the hydraulic pressure in the flow path 8 decreases due to pulsation, stoppage, load fluctuation, and the like of a pump (not shown), the metal bellows 5 contracts in a direction to maintain the hydraulic pressure in the flow path 8. And
When the liquid pressure in the flow path 8 becomes lower than the gas pressure sealed in the accumulator, the valve element 7 is pressed against the periphery of the opening 8a as shown by an imaginary line, and closes the opening 8a to close the opening 8a. Is self-sealed so that the pressure of the gas chamber 4 does not become lower than the same pressure.

Here, in order to ensure the airtightness between the liquid chamber 3 and the gas chamber 4, the edge of the cap member 6 and the edge of the metal bellows 5 are joined in a state where they are precisely aligned. There is a need. Further, in order to ensure that the valve 7 closes the opening 8a, the valve 7 needs to be attached to the cap member 6 with high positional accuracy in addition to the above.

Therefore, in this configuration, a concave portion 6a formed by drawing is formed at the center of the cap member 6, the outer peripheral edge of the cap member 6 is processed with reference to the concave portion 6a, and the valve element 7 is formed in the concave portion 6a. It is attached on the basis of. In addition, it is positioned and joined to the metal bellows 5 with reference to the recess 6a.

Specifically, to manufacture the cap member 6, first, a disc-shaped flat plate is formed by punching, and a concave portion 6a is formed at the center by drawing or pressing. Then, the concave portion 6a is held, positioned by this, and the peripheral edge is processed by press working. Here, the periphery may be cut by a lathe. Next, similarly, the concave portion 6a
The cap member 6 is completed by forming a valve body 7 made of an elastomer material such as rubber by vulcanization.

Further, the concave portion 6a is held in the same manner as described above, and is positioned by this. The free end edge of the metal bellows 5 which is positioned while holding the inner or outer diameter is aligned with the peripheral edge of the cap member 6 and joined by welding or the like. Thus, the metal bellows assembly 2 is completed. The open end opposite to the cap member 6 of the metal bellows assembly 2 is joined to the housing 1 by welding or the like.

As shown in the figure, in an accumulator of this type in which a gas chamber is defined outside the metal bellows 5, a gas filling hole 10 is formed on the side of the housing 1 opposite to the opening 8a. Plug retainer 1 formed with
1 is provided. Since the plug retainer 11 fits and holds the plug 12 after gas is sealed, it often projects inward. Therefore, if the diameter and depth of the concave portion 6a are set so that the protruding portion 11a enters when the metal bellows 5 is extended, the stroke of the metal bellows 5 can be increased, and the pressure accumulation capacity increases.

In the above construction, the interior of the metal bellows 5 is the liquid chamber 3, and the interior of the housing 1 and the exterior of the metal bellows 5 is the gas chamber 4. On the contrary, the interior of the metal bellows 5 is the gas chamber. Needless to say, the liquid chamber inside the metal bellows 5 and outside the metal bellows 5 may be used.

[0015]

As is apparent from the above description, according to the accumulator and the method of manufacturing the same according to the present invention,
An extensible metal bellows, one end of which is fixed to the pressure vessel and the other end of which is closed by a cap member, for separating the inside of the pressure vessel into a liquid chamber connected to an external circuit and a gas chamber in which high-pressure gas is sealed. A concave portion is formed by drawing at the center of the cap member of an accumulator provided with a valve body that closes an opening of a flow path communicating with an external circuit in a cap member of a metal bellows, and processing of an outer peripheral edge of the cap member By mounting the valve body with reference to this recess, not only the accuracy is improved compared to the case where the punched edge is used as a reference, but also there is no need to change the periphery when pressing or cutting the edge. Therefore, even if multiple processings are performed on the periphery, the alignment will not be out of order,
Man-hours are also reduced.

[Brief description of the drawings]

FIG. 1 is a side sectional view of an accumulator showing a first embodiment to which the present invention is applied.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Housing 2 Metal bellows assembly 3 Liquid chamber 4 Gas chamber 5 Metal bellows 6 Cap member 6a Concave part 7 Valve 8 Flow path 8a Opening 10 Gas filling hole 11 Plug retainer 11a Projecting part 12 Plug

Claims (3)

[Claims] 1. One end is fixed to the pressure vessel so as to be received in the pressure vessel, and the inside of the pressure vessel is separated into a liquid chamber connected to an external circuit and a gas chamber sealed with high-pressure gas, and An accumulator provided with a valve body that has an elastic metal bellows whose other end is closed by a cap member and that closes an opening of a flow path communicating with the external circuit in the cap member of the metal bellows, The cap member has a concave portion formed by drawing at the center thereof, an outer peripheral edge of the cap member is processed based on the concave portion, and the valve body is attached based on the concave portion. The accumulator characterized by the above. 2. The interior of the metal bellows forms the liquid chamber, the space between the pressure vessel and the metal bellows forms the gas chamber, and the valve element is opposite to the recess of the cap member of the gas chamber. The accumulator according to claim 1, wherein the accumulator is provided on a convex surface. 3. One end is fixed to the pressure vessel so as to be received in the pressure vessel, and to separate the inside of the pressure vessel into a liquid chamber connected to an external circuit and a gas chamber sealed with high-pressure gas, and A method for manufacturing an accumulator, comprising: a telescopic metal bellows whose other end is closed by a cap member, and a valve body for closing the opening of a flow path communicating with the external circuit in the cap member of the metal bellows. An accumulator, wherein a concave portion is formed by drawing at the center of the cap member, an outer peripheral edge of the cap member is processed based on the concave portion, and the valve body is attached based on the concave portion. Manufacturing method.