JP3148351U - accumulator - Google Patents

Abstract

An accumulator is provided which is inexpensive and can improve safety. An accumulator (1) includes a cylindrical member (26) connected to an oil passage hole (30) for introducing hydraulic oil into an oil chamber (L), and a seal provided around a communication hole (33) communicating with the oil chamber of the cylindrical member (26). A member 34 and a bellows cap 52 attached to a metal bellows 51 of a bellows mechanism 50 housed in the pressure vessel 10 and having a fragile portion 53, the fragile portion 53 being a gas in the pressure vessel 10. When the gas pressure in the chamber G is increased, the bellows cap 52 is broken before the pressure vessel 10 so that the gas chamber G and the hydraulic circuit are made continuous. [Selection] Figure 1

Description

  The present invention relates to a pressure vessel such as an accumulator used in a hydraulic circuit, and more particularly to an inexpensive one that improves accuracy.

  Metal bellows type accumulators (accumulation / buffer devices) are used in hydraulic circuits such as hydraulic circuits of hydraulic control devices and hydraulic circuits using shock absorbers. Generally, a metal bellows type accumulator is obtained by bonding a bellows and a trapezoidal seal member by vulcanization adhesion to a pressure vessel formed by joining an outer shell member and a lid by welding or the like. A bellows mechanism composed of a partition plate is provided. In such an accumulator, the inside of the pressure vessel is partitioned into a gas chamber and a liquid chamber (oil chamber) by a bellows mechanism. Further, the pressure vessel is configured to buffer the pressure fluctuation of the liquid flowing into the hydraulic circuit and the accumulator by the expansion and contraction action of the gas in the gas chamber accompanying the expansion and contraction of the bellows mechanism.

  In the accumulator, when the pressure in the liquid chamber becomes lower than the pressure in the gas chamber, the seal member covers the opening provided in the communication portion that continuously connects the hydraulic circuit and the liquid chamber, and the Close the opening to close the opening. By closing the opening with the seal member, a certain amount of liquid is sealed in the liquid chamber, and the balance between the sealed liquid and the gas in the gas chamber prevents excessive deformation of the bellows toward the liquid chamber. What to do is known. In addition, what is provided in the circumference | surroundings of an opening part is also known rather than providing a sealing member in a partition plate.

  In such an accumulator, for example, when the temperature of the accumulator rises due to a fire or the like, the gas pressure in the gas chamber rises abnormally. Due to this abnormal increase in gas pressure, the pressure vessel of the accumulator may be destroyed. In particular, since gas is used in the pressure vessel, if the pressure vessel is destroyed, there is a risk of causing secondary damage to the outside, such as scattering of the destroyed pressure vessel.

  For this reason, in order to prevent damage to the pressure vessel due to a fire or the like, a member that seals the hydraulic circuit and the liquid chamber in the liquid chamber closed by the seal member via the bellows mechanism by gas pressure, for example, a communication portion An accumulator having a fragile portion (relief means) such as a spot facing is also known (see, for example, Patent Document 1). In order to seal the hydraulic circuit and the liquid chamber, the communication portion having such a weak portion is formed into a cylindrical shape by pressing from a plate material, and the weak portion is formed on the side surface of the communication portion formed in the cylindrical shape. Processed and provided.

As described above, a case where the gas pressure becomes high in a state where the liquid chamber is sealed due to a fire or the like by using the communication portion having the fragile portion will be described. First, due to a relief or the like provided in the hydraulic pressure circuit, the pressure of the hydraulic pressure circuit becomes zero or low pressure, so-called zero down. At this time, the gas in the gas chamber expands due to heat, and the gas pressure becomes high. Moreover, it is pressed by the gas pressure through the bellows mechanism, and the hydraulic pressure in the liquid chamber also becomes high due to heat. The fragile portion is destroyed by this high pressure. Further, the bellows mechanism is destroyed by the gas pressure. The gas in the gas chamber escapes from the gas chamber through the broken bellows mechanism, the liquid chamber, and the broken fragile portion into the hydraulic circuit, thereby preventing the pressure vessel from being broken.
JP 2004-270763 A

  The accumulator described above has the following problems. That is, in order for the gas in the gas chamber to escape to the hydraulic circuit, after the gas pressure becomes high, the fragile portion must be destroyed by the oil pressure in the oil chamber L, and further, the metal bellows must be destroyed by the gas pressure. is there. However, if the metal bellows is not destroyed even if the fragile part is destroyed, the pressure in the gas chamber is not released into the hydraulic circuit. is there. For this reason, a method for releasing the pressure in the gas chamber more directly is demanded.

  Moreover, in order to provide a weak part in a communication part, the process process which processes a weak part is required after the process of a communication part. In addition, since the communicating portion is cylindrical, when processing the fragile portion by, for example, milling, the thickness of the fragile portion portion is uneven and processing accuracy is required, or processing is not easy, There are also problems such as. This increases the manufacturing cost.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an accumulator that is inexpensive and can improve safety.

  In order to solve the above problems and achieve the object, the accumulator of the present invention is configured as follows.

  A bottomed cylindrical outer shell member, and a pressure vessel including a lid body that closes an opening of the outer shell member and has an inflow hole through which liquid can flow into and out of the outer shell member; A metal bellows formed to be stretchable along the inner wall surface of the pressure vessel, and provided on the metal bellows, and moves along the metal bellows along the inner wall surface of the pressure vessel. A disk-shaped partition plate having a weakened portion formed on the extension of the inflow hole, and a liquid chamber and a gas capable of flowing in and out of the liquid through the pressure vessel by the metal bellows and the partition plate. A bellows mechanism for partitioning into a sealable air chamber, and a seal member provided on the lid body and formed so as to be capable of liquid sealing the liquid chamber by contacting the partition plate. And

  According to the present invention, the pressure vessel can be prevented from being damaged, and the accumulator can be made inexpensive and improved in safety.

  FIG. 1 is a longitudinal sectional view showing a configuration of an accumulator 1 according to an embodiment of the present invention, and FIG. 2 is a longitudinal sectional view showing movement of a bellows mechanism 50 of the accumulator 1. 1 and 2, G represents a gas chamber (air chamber), L represents an oil chamber (liquid chamber), and S represents a welded portion (joined portion) of the pressure vessel 10.

  As shown in FIGS. 1 and 2, the accumulator 1 includes a pressure vessel 10 and a bellows mechanism 50 accommodated in the pressure vessel 10. Such an accumulator 1 is connected to, for example, a brake hydraulic circuit for a vehicle.

  The pressure vessel 10 includes a steel pipe 11 formed of a bottomed cylindrical steel material that is an outer shell member, and a lid 13 that is coupled to an opening 12 of the steel pipe 11. Moreover, the pressure vessel 10 is comprised by welding the steel pipe 11 and the cover body 13 with the welding part (joining part) S, for example. The pressure vessel 10 has therein a gas chamber G formed by the steel pipe 11 and the bellows mechanism 50 and an oil chamber L formed by the lid 13 and the bellows mechanism 50.

  The steel pipe 11 has a pipe part 15 and an end part (hereinafter referred to as “bottom part”, which is located at the upper part in FIGS. 1 and 2) 16 formed by, for example, deep drawing using a press. The steel pipe 11 may be subjected to heat treatment such as annealing after deep drawing. In the steel pipe 11, the opening 12 is located on one end (the other side of the bottom 16) side of the pipe part 15.

  In the steel pipe 11, an inner wall surface 17 is formed by an inner peripheral surface 15 a of the pipe portion 15 and an inner surface 16 a of the bottom portion 16. A gas chamber G is formed by a part of the lid 13, the inner wall surface 17 and the bellows mechanism 50. Note that the lid 13 is inserted into the opening 12, and the lid 13 is welded at the welded portion S.

  A circular through hole 18 is formed in the bottom portion 16. The through-hole 18 is hermetically closed to the gas sealing plug 19 by means of welding or the like after the gas is sealed. Further, the bottom portion 16 is provided with a cover 20 having a hexagonal cross section, for example, outside the through hole 18.

  The lid body 13 includes a lid body 21 formed in a disc shape, a port portion 22 provided on the axis of the lid body 21, and a port portion 22 of the lid body 21. A surface 23 and a second surface 24 opposite to the first surface 23 are provided. Further, the lid body 13 includes a cylindrical member 26 joined on the axis of the lid body 21 and on the second surface 24 side by welding, for example.

  The lid body 21 has an outer diameter at least such that the second surface 24 side is located inside the steel pipe 11 and the first surface 23 is exposed to the outside of the steel pipe 11 by being inserted into the opening 12. It has a diameter. Further, on the second surface 24 side of the side surface portion 27 of the lid body 21, a seal groove 29 into which a ring-shaped blocking seal 28 formed of a resin material or the like is inserted is provided.

  More specifically, the lid body 21 is formed such that the first surface 23 side has a larger diameter than the inner peripheral diameter of the tube portion 15, and the second surface 24 side has a smaller diameter than the inner peripheral diameter of the tube portion 15. . Moreover, the welding part S provided with the curved surface part 12a of the steel pipe 11 is provided in the 1st surface 23 side rather than the seal groove 29 of the side surface of the cover body 21 and melt | dissolves at the time of welding. Here, the blocking seal 28 is formed so as to be able to block spatter (welded pieces or the like) generated when the curved surface portion 12a and the welded portion S are welded. There is no entry into. The blocking seal 28 and the seal groove 29 are exposed to the gas chamber G.

The port portion 22 is provided with an oil passage hole 30 through which the oil chamber L and hydraulic oil flow in and out. Moreover, the port part 22 is connected on piping of the hydraulic circuit which is not illustrated, for example.
The cylindrical member 26 has a hollow portion 31 formed therein and is continuous with the oil passage hole 30. In addition, a communication hole (inflow hole) 33 that connects the cavity 31 and the oil chamber L is provided in the end surface portion 32 of the cylindrical member 26. The cylindrical member 26 is provided with a seal member 34 on the outer surface of the end surface portion 32, that is, on the surface facing the bellows mechanism 50.

  The seal member 34 is formed of an elastic resin material having an annular shape (ring shape) and a square cross section. The seal member 34 is bonded to the outer surface of the end surface portion 32 and the periphery of the communication hole 33 with, for example, a vulcanized adhesive.

  The resin material used for the seal member 34 may be any material that has resistance to hydraulic oil used in a hydraulic circuit of a brake and exhibits sealing properties by elastic deformation. Further, the resin material can be appropriately changed depending on the use of the accumulator 1.

  The bellows mechanism 50 is formed in a cylindrical shape, and one end of the opening is a metal bellows 51 disposed on the second surface 24 of the lid body 21 and a disk shape attached to the other of the opening ends of the metal bellows 51. The bellows cap (partition plate) 52 is provided. Further, the bellows mechanism 50 includes a guide 52 a that is attached to the outer peripheral portion of the bellows cap 52 and formed to be slidable.

  One end of the metal bellows 51 that contacts the second surface 24 is joined to the second surface 24 of the lid body 21 by welding. The junction between the metal bellows 51 and the lid body 21 has liquid (air) tightness between the oil chamber L and the gas chamber G.

  In the bellows cap 52, the other end of the metal bellows 51 is welded to the surface (the surface on the oil chamber L side) facing the lid body 13. With this connection, the connecting portion (welded portion) between the bellows cap 52 and the metal bellows 51 has liquid (air) tightness between the oil chamber L and the gas chamber G.

  The bellows cap 52 is formed so that the inner wall surface 17 can be smoothly slid when the bellows cap 52 moves in accordance with the expansion and contraction of the metal bellows 51. In addition, although it has the structure which has the guide 52a in the outer peripheral part of the bellows cap 52, the outer peripheral part of the bellows cap 52 should be able to move smoothly along the inner wall surface 17, and does not have to contact 17 directly. The bellows cap 52 is only formed so that the inner wall surface 17 can be smoothly slid, and the gas chamber G communicates with the space of the inner wall surface 17 and the metal bellows 51.

  The bellows cap 52 is provided on the axial center of the bellows cap 52 and is formed of a metal material, and includes a weakened portion 53 provided on the axial center or on the extension of the axial center of the communication hole 33. Have. The bellows cap 52 is formed in one process including the fragile portion 53 by, for example, pressing. That is, the bellows cap 52 is manufactured by press molding using a die that forms the outer shape and the weakened portion 53.

  The weak portion 53 is formed such that the surface of the bellows cap 52 on the gas chamber G side is thin. The thickness of the fragile portion 53 is formed to a depth that allows the bellows cap 52 to be broken at a pressure lower than the breaking pressure of the pressure vessel 10.

  That is, the bellows cap 52 is a portion where the breaking pressure is lower than the breaking pressure of the pressure vessel 10 by forming a part of the weak portion 53 so as to break at a pressure lower than the breaking pressure of the pressure vessel 10. have. Here, the thickness of the fragile portion 53 is a thickness at which the bellows cap 52 does not break and is broken at a pressure lower than the breaking pressure of the pressure vessel 10 when the normal accumulator 1 is used. It can be set as appropriate.

  In the accumulator 1 configured as described above, when the pressure in the hydraulic circuit rises and the pressure in the cavity portion 31 becomes higher than the pressure in the gas chamber G, the oil passage hole 30 in the port portion 22 and the cavity portion 31 in the cylindrical member 26. The hydraulic oil in the hydraulic circuit flows into the oil chamber L through the communication hole 33. Due to the inflow of the hydraulic oil, the pressure (hydraulic pressure) in the oil chamber L becomes the same as the pressure in the hydraulic circuit, and the accumulator 1 accumulates the pressure in the hydraulic circuit and buffers the pulsation in the hydraulic circuit. Become. At this time, the gas pressure in the gas chamber G is compressed so as to be the same as the oil pressure in the oil chamber L.

  That is, when the pressure in the hydraulic circuit increases and the hydraulic pressure in the oil chamber L increases, the metal bellows 51 expands and the gas in the gas chamber G contracts (compresses) by the hydraulic pressure, as shown in FIG. Due to the contraction of the gas in the gas chamber G, the hydraulic oil and the gas are balanced at a predetermined position.

  Next, when the pressure in the hydraulic circuit is increased, the pressure in the oil chamber L is increased, the gas is further contracted, and the metal bellows 51 is expanded. At this time, at least one of the pressure and volume of the gas in the gas chamber G is adjusted according to the specifications of the accumulator 1 such as the working pressure and temperature in the hydraulic circuit, and the metal bellows 51 has a guide 52a in the pipe portion 15. Only the range in which the peripheral surface 15a slides is expanded and contracted.

  Next, when the pressure in the hydraulic circuit decreases, the pressure of the hydraulic oil in the oil chamber L also decreases, and the gas in the gas chamber G expands. As a result, the metal bellows 51 contracts. Thereby, the gas in the gas chamber G expands. At this time, when the oil pressure in the oil chamber L becomes lower than the predetermined pressure and falls below the predetermined pressure, the metal is moved to a position where the bellows cap 52 and the seal member 34 come into contact with each other as shown in FIG. The bellows 51 contracts and the bellows cap 52 moves.

  When the bellows cap 52 and the seal member 34 come into contact with each other, the periphery of the communication hole 33 of the cylindrical member 26 is sealed by the seal member 34, and the oil chamber L is connected to the cylindrical member 26 from the oil passage hole 30 of the port portion 22. The space to the communication hole 33 is closed (liquid sealed) through the hollow portion 31. Due to the blockage of the oil chamber L, the hydraulic oil located between the outer peripheral surface of the cylindrical member 26 and the metal bellows 51 from the bellows cap 52 does not move from the communication hole 33 into the hydraulic circuit. For this reason, it becomes possible to restrict | deform the deformation | transformation to the center direction of the metal bellows 51 by gas pressure with gas pressure and the hydraulic pressure of hydraulic fluid.

Here, for example, a case where the accumulator 1 is exposed to a high temperature due to a fire or the like will be described.
When the accumulator 1 is exposed to a high temperature, the temperature of the accumulator 1 rises, and accordingly, the temperature of the gas and hydraulic oil in the accumulator 1 rises.

  At this time, due to a temperature rise due to a fire, the relief mechanism of the hydraulic circuit is operated, and the hydraulic pressure in the hydraulic circuit becomes substantially zero or low pressure, so-called zero down. Note that the gas pressure in the gas chamber G increases as the temperature rises. As shown in FIG. 2, in the accumulator 1, since the gas pressure in the gas chamber G is higher than the hydraulic pressure in the hydraulic circuit, the metal bellows 51 contracts and the bellows cap 52 is pressed against the seal member 34 provided on the cylindrical member 26. Will be.

  The gas pressure and the oil pressure in the oil chamber L are higher than the normal operating pressure due to the temperature rise by the accumulator 1. A high gas pressure from the gas chamber G is applied to the pressure vessel 10 and the bellows cap 52. As a result, the bellows cap 52 is broken at the fragile portion 53 by the high gas pressure.

  In the accumulator 1, the gas chamber G, the communication hole 33, the cavity 31, and the oil passage hole 30 are continuous through the broken bellows cap 52. As a result, the gas chamber G and the hydraulic circuit are continuous, gas enters the hydraulic circuit, and the gas pressure in the gas chamber G decreases.

  According to the accumulator 1 configured as described above, when the accumulator 1 is exposed to a high temperature such as a fire and the temperature of the accumulator 1 rises, the pressure of the hydraulic circuit becomes substantially zero due to burnout of each part seal or operation of the relief mechanism. Become. Further, the gas pressure in the gas chamber G, which has become high pressure, rises, and as a result, the fragile portion 53 of the bellows cap 52 is broken. As the bellows cap 52 is broken, the gas chamber G and the hydraulic circuit are continuous, so that the gas in the gas chamber G moves into the hydraulic circuit, and the gas pressure in the gas chamber G increased at high temperature is reduced. It becomes possible. Due to the decrease in the gas pressure in the gas chamber G, it is possible to prevent the pressure vessel 10 from being destroyed, and it is possible to prevent a secondary disaster due to the destruction of the pressure vessel 10.

  In addition, the secondary disaster by destruction of the pressure vessel 10 which may generate | occur | produce because of the structure which does not have the weak part 53 is demonstrated. The high-pressure gas accumulated in the pressure vessel 10 expands rapidly when the pressure vessel 10 is broken, so that the pressure vessel 10 is ruptured vigorously. The parts of the pressure vessel 10 destroyed by this bursting are scattered in four directions around the accumulator 1.

  Such scattering of the destructive parts of the pressure vessel 10 is not only the destruction of the accumulator 1, but causes, for example, injury or breakage when it hits a vehicle body component, a vehicle occupant, or a person or an object located around the vehicle body. It becomes.

  However, by providing the fragile portion 53 as in the present invention, it is possible to prevent the pressure vessel 10 from being destroyed by releasing the gas pressure from the fragile portion 53 when the gas pressure in the gas chamber G increases. Thus, it is possible to prevent such a secondary disaster. That is, the safety of the accumulator 1 can be improved.

  Furthermore, by providing the fragile portion 53 in the bellows cap 52, the fragile portion 53 may be broken only by the gas pressure, and the fragile portion 53 can be directly broken by the gas pressure. For this reason, when the gas pressure increases, the fragile portion 53 can be directly destroyed by the gas pressure, and the gas can be reliably discharged into the hydraulic circuit, thereby improving the reliability. .

  Further, by providing the bellows cap 52 with the fragile portion 53, the fragile portion 53 can be formed in the same process when the bellows cap 52 is processed, thereby reducing the processing steps. Moreover, since the bellows cap 52 is disk-shaped and the weak part 53 is provided in this disk shape, since the depth of the weak part 53 (thickness of the bellows cap 52 in the weak part 53) becomes constant, Processing accuracy can be easily obtained. As a result, the manufacturing cost can be reduced. Furthermore, it is possible to easily obtain the processing accuracy, that is, it is possible to improve the dimensional accuracy by easy processing.

  As described above, according to the accumulator 1 according to the present embodiment, the fragile portion 53 having a breaking pressure lower than that of the pressure vessel 10 is provided in a part of the bellows cap 52, thereby preventing the pressure vessel 10 from bursting. It becomes possible. Further, by preventing the pressure vessel 10 from rupturing, it is possible to prevent secondary disasters and improve the safety of the accumulator 1. In addition, it is possible to reduce the processing step and processing accuracy of the fragile portion 53, and it is also possible to reduce the manufacturing cost of the accumulator 1.

  The present invention is not limited to the above embodiment. For example, in the above-described example, the accumulator 1 is used in a hydraulic circuit for braking a vehicle body, but can be applied to other hydraulic circuits. Further, not only the hydraulic circuit but also other pressure circuits can be used. Furthermore, although the weak part 53 mentioned above was formed in one process by press work, it is not necessarily limited to this. Press work may be two steps. Even if the pressing process is two steps, if the pressing process is performed on the same line, there is almost no influence of the manufacturing cost accompanying the increase of the process, and the mold used during the pressing process becomes simple, so the cost of the mold is reduced. Can be reduced. In addition, the fragile portion 53 is preferably press-worked, but the fragile portion 53 may be formed by cutting or countersinking with a milling cutter or the like. Since the base plate 52 has a disk shape, it can be easily cut and the dimensional accuracy by the machining can be easily obtained with high accuracy. For this reason, it becomes possible to reduce processing cost rather than providing the weak part 53 in the side surface of a cylindrical member (cylindrical member 26). Moreover, since the weak part 53 is provided in the disk-shaped base plate 52, it becomes possible to improve a dimensional accuracy and also to improve reliability.

  In addition, the fragile portion 53 is processed into a disk concave shape, but is not limited to the disk concave shape. For example, a square shape or a cross-shaped groove may be used. That is, when the pressure in the gas chamber G of the accumulator 1 becomes high, the required durability (fatigue strength) is satisfied because the bellows cap 52 is broken before the pressure vessel 10 is broken. If the pressure vessel 10 can be prevented from bursting, its shape can be set as appropriate.

  Furthermore, although the cross-sectional shape of the sealing member 34 described above is rectangular, it is not limited to this and can be changed as appropriate. In addition, various modifications can be made without departing from the scope of the present invention.

Sectional drawing which shows the structure of the accumulator which concerns on one embodiment of this invention. Sectional drawing which shows the structure of the accumulator.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Accumulator, 10 ... Pressure vessel, 11 ... Steel pipe, 12 ... Opening part, 12a ... Curved surface part, 13 ... Lid, 15 ... Pipe part, 15a ... Inner peripheral surface, 16 ... End part, 16 ... Bottom part, 16a ... Inner wall surface, 17 ... inner wall surface, 18 ... through hole, 19 ... gas sealing plug, 20 ... cover, 21 ... cover body, 22 ... port portion, 23 ... first surface, 24 ... second surface, 26 ... cylindrical member, 27 ... side face part, 28 ... blocking seal, 29 ... seal groove, 30 ... oil passage hole, 31 ... hollow part, 32 ... end face part, 33 ... communication hole (inflow hole), 34 ... seal member, 50 ... bellows mechanism, 51 ... Metal bellows, 52 ... Bellows cap (partition plate), 53 ... Fragile part, G ... Gas chamber, L ... Oil chamber, S ... Welded part.

Claims (1)

A bottomed cylindrical outer shell member, and a pressure vessel including a lid body that closes an opening of the outer shell member and has an inflow hole through which liquid can flow into and out of the outer shell member;
A metal bellows formed to be stretchable along the inner wall surface of the pressure vessel, and provided on the metal bellows, and moves along the metal bellows along the inner wall surface of the pressure vessel. A disk-shaped partition plate having a weakened portion formed on the extension of the inflow hole, and a liquid chamber and a gas capable of flowing in and out of the liquid through the pressure vessel by the metal bellows and the partition plate. A bellows mechanism that divides the air chamber into a sealable chamber
An accumulator comprising: a sealing member provided on the lid body, wherein the liquid chamber is formed in contact with the partition plate so that the liquid chamber can be liquid-sealed.

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