JP4264738B2 - accumulator - Google Patents

Description

  The present invention relates to an accumulator used as a pressure accumulator or a pulse pressure attenuator.

  Conventionally, as shown in FIG. 13, the inside of a housing 52 having a pressure inlet 53 is communicated with a pressure sealing chamber 57 and a pressure inlet 53 in which a predetermined pressure is sealed by an operating member 54 having a bellows 55 and a bellows cap 56. When the pressure on the system (not shown) side connecting to the accumulator 51 drops, the backup fluid (not shown) in the pressure inflow chamber 58 flows out and the bellows 55 An accumulator 51 provided with a seal mechanism 59 that suppresses breakage due to a difference in pressure between the inside and the outside is known (see FIG. 1 of Patent Document 1), and as shown in FIG. In preparation for the case where the sealing function is lost due to foreign matter being caught in 59, the sealing mechanism is indicated by reference numerals 59A and 59B. And to accumulator 51 is known a (see also FIG. 2 of Patent Document 1).

  However, according to the above prior art, in both the case of FIG. 13 and FIG. 14, the seal mechanisms 59, 59A, 59B are all constituted by a rubber seal having a seal member 60 made of rubber-like elastic material. Due to the characteristics of the material, there is a disadvantage that fatigue occurs relatively quickly or wear due to biting of foreign matter.

JP 2000-249101 A

  In view of the above, an object of the present invention is to provide an accumulator that can improve the durability of a seal mechanism in an accumulator having an internal / external double seal mechanism that suppresses the outflow of backup fluid to the bellows.

  In addition to this, even when the backup fluid is sealed with a metal seal, a part of the circumference of the metal seal melts when an abnormally high temperature such as a fire occurs, and the backup fluid flows out from this melted part. An accumulator that can discharge the sealed pressure (filled gas) in the bellows from the melted part after the bellows is damaged due to the increased sealed pressure, and can prevent the housing from being damaged by the increased sealed pressure. The purpose is to provide.

In order to achieve the above object, an accumulator according to claim 1 of the present invention includes a pressure sealing chamber in which a predetermined pressure is sealed by an operating member having a bellows and a bellows cap inside a housing having a pressure inlet, and the pressure inlet. An internal / external double seal mechanism is provided to prevent the bellows from being damaged by the back-up fluid in the pressure inflow chamber flowing out when the pressure on the system side to which the accumulator is connected is reduced. In the accumulator, the metal that seals the back-up fluid when the metal contact portion provided on the bellows cap contacts the metal contact portion provided on the inner surface of the housing. and the seal, the circumference on one of the circumferentially part abutted portion or the abutting portion To, and is characterized in that it has to have arranged the melting member is melted at a specified temperature in a fire or the like abnormally high temperature occurred.

  The present invention has the following effects.

That is, according to the accumulator according to claim 1 of the present invention having the above-described configuration, since the outer peripheral seal mechanism of the inner and outer double seal mechanisms is a metal seal that contacts the metals, From the above characteristics, it has the characteristic that it is hard to be fatigued or worn out. Therefore, it is possible to provide an accumulator capable of improving the durability of the internal and external double seal mechanism that suppresses the outflow of the backup fluid as intended.

However, if the seal mechanism on the outer peripheral side is a metal seal in this way, the metal seal does not easily melt even if a fire or the like occurs, so the metal seal continues to hold the backup fluid. Therefore, in this state, when the enclosed pressure in the bellows rises as the temperature rises and the bellows expands, the internal pressure of the entire housing may rise and the housing may be damaged. Therefore, in the accumulator of the present invention, by arranging a melting member that melts at a specified temperature on a part of the circumference of the contacted part or a part of the circumference of the contacted part, when a fire or the like occurs This melting member was melted. That is, when a fire or the like occurs and the melting member melts due to the high heat, the metal seal loses its sealing function.In this state, if the sealing pressure in the bellows rises as the temperature rises and the bellows expands, the backup fluid is pressurized. It becomes possible to discharge from the inlet to the outside. In addition, even if the bellows is broken due to expansion, the sealed pressure can be discharged from the pressure inlet to the outside. Therefore, in any case, if a melting member is disposed on the contacted portion or a part of the circumference of the contacting portion, a pressure release channel is formed when the melting member is melted, and the housing is damaged. Can be prevented beforehand.

  The present application includes the following embodiments.

(1) The back-up fluid is prevented from flowing out by the metal seal when the seal of the metal bellows type accumulator expires.
(2) A metal seal mechanism comprising a bellows cap and an oil port is configured to suppress the outflow of backup fluid when the seal expires due to lip seal breakage or contamination trapping in a metal bellows type accumulator.
(3) In order to reduce the change in bellows profile due to outflow of the backup fluid when the lip seal is missing, a metal seal is provided at the end face of the oil port that serves as a stopper for the bellows cap.
(4) A metal seal is provided at the bellows cap and the oil port end face without installing a sealing material to prevent or suppress the outflow of the backup fluid.
(5) An oil port end face is provided with an inclination, and the bellows cap contact portion is formed in an R shape to improve the metal sealability.
(6) A sealing part is improved by installing a convex part in the oil port and performing metal sealing at the part. The convex portion may be R-shaped or square-shaped. The mating surface may be a tapered surface.
(7) A convex part is installed in the bellows cap, and the sealing performance is improved by metal sealing at the part. The convex portion may be R-shaped or square-shaped. The mating surface may be a tapered surface.

(8) A metal that melts at a specified temperature is placed in the metal seal part.
(9) In the event of a fire, the lip seal is carbonized and the seal expires, but the backup fluid is retained by the metal seal, the enclosed gas pressure increases with the temperature rise, and the shell is damaged. To prevent this, in the event of a fire, a metal (eutectic metal, etc.) or resin material that melts when the specified temperature is reached is placed on the oil port end seal surface, and the metal seal is expired at the melting temperature for backup. After the fluid is discharged, the bellows expands with the enclosed gas pressure, and the internal gas is discharged outside through the oil port hole. Note that the melting temperature is lower than the temperature at which the strength of other components is reduced, and is not higher than the temperature at which the lip seal (rubber) is carbonized. Furthermore, this mechanism may be provided on the bellows cap side. In this way, in the event of a fire, even if the gas pressure rises due to a temperature rise, the gas is discharged from the oil port side, and the shell is not damaged due to the rise in the enclosed gas pressure.

  Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 shows a longitudinal section of an accumulator 1 according to an embodiment of the present invention. FIG. 2 shows an enlarged cross-section of the main part, and FIG. 3 shows an enlarged view of part A in FIG .

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

  That is, first, a gas end cover 4 and an oil port (broadly defined oil port) 5 are fixed (welded) to both ends of a substantially cylindrical shell 3, thereby providing a housing 2. An operating member 6 having a bellows 7 and a bellows cap 8 is accommodated therein. The gas end cover 4 may be formed integrally with the shell 3, and the oil port 5 may be formed integrally with the shell 3. The shell 3, the gas end cover 4, the oil port 5, and the bellows cap 8 are each formed of a predetermined metal material.

  One end (fixed end) of the bellows 7 is fixed (welded) to the gas end cover 4 and the other end (floating end) is fixed (welded) to the bellows cap 8. The inside of the housing 2 is divided into a pressure sealing chamber (gas chamber) 9 inside the operating member 6 and a pressure inflow chamber (fluid chamber) 10 outside by the operating member 6 composed of 7 and a bellows cap 8. A vibration damping ring 11 that is slidably in contact with the inner peripheral surface of the shell 3 is attached to the outer periphery of the other end of the bellows 7 so that the bellows 7 does not bite against the inner peripheral surface of the shell 3. . The bellows 7 is a metal bellows made of an electrodeposition bellows, a molded bellows, a welded bellows, or the like. However, depending on the specifications and applications of the accumulator 1, a bellows of other materials can be used. The bellows cap 8 may be integrally formed with the bellows 7. One end of the bellows 7 is fixed to an inward flange portion 4a provided at the outer peripheral edge of the gas end cover 4. Instead of the flange portion 4a, an annular mounting member (not shown) is used here. ) Is fixed, one end of the bellows 7 is fixed to the mounting member.

  A gas inlet 12 for injecting gas into the pressure sealing chamber 9 is provided in the gas end cover 4 constituting a part of the housing 2, and a gas plug for closing the gas inlet 12 is provided in the inlet 12. 13 is attached and covered with a hex nut 14. Therefore, by injecting a gas of a predetermined pressure from the inlet 12 into the pressure sealing chamber 9 before fixing the gas plug 13 and the hexagon nut 14, and fixing the gas plug 13 and the hexagon nut 14 (both are welded) after the injection, A gas having a predetermined pressure is sealed in the pressure sealing chamber 9. Nitrogen gas or the like is suitable as the type of gas to be sealed. A spacer 15 for adjusting the volume of the pressure sealing chamber 9 is incorporated inside the pressure sealing chamber 9 and inside the gas end cover 4.

  Also, a cylindrical mounting portion 16 having a screw portion 17 for connecting the accumulator 1 to a pressure pipe or the like on the hydraulic system side (not shown) is provided on the oil port 5 that also constitutes a part of the housing 2. The mounting portion 16 is provided with a pressure inlet (narrow sense oil port) 18 for introducing the pressure fluid on the pipe side into the pressure inflow chamber 10. Therefore, the accumulator 1 is connected to the pipe side at the mounting portion 16, and the pressure on the pipe side is introduced from the pressure inlet 18 into the pressure inflow chamber 10.

  Further, the accumulator 1 according to this embodiment is provided with inner and outer double-seal seal mechanisms 21 and 26 configured as follows. The seal mechanisms 21 and 26 are configured so that a backup fluid (not shown, part of pressure oil such as brake oil) in the pressure inflow chamber 10 is stored in the accumulator when the pressure on the hydraulic system side to which the accumulator 1 is connected is extremely reduced. 1. It is provided to prevent the bellows 7 from flowing out to the outside and being damaged due to the pressure difference between the inside and outside.

  That is, first, an annular recess-shaped seal mounting portion 22 is provided on the inner surface (upper surface) of the oil port 5, and a lip seal 23, which is a seal member made of rubber-like elastic material, is mounted on the seal mounting portion 22. An annular recess-shaped holder mounting portion 24 is provided on the inner peripheral side of the seal mounting portion 22 and between the seal mounting portion 22 and the pressure inlet 18, and the holder mounting portion 24 has a substantially L-shaped cross section. A seal holder 25 made of a metal ring is attached (welded). The lip seal 23 made of rubber-like elastic material is formed by integrally forming an outward seal lip 23b at one end (upper end) of the base 23a. When the bellows cap 8 is lowered by the extension of the bellows 7, the bellows The cap 8 abuts the seal lip 23b with its end surface (lower surface) to seal the backup fluid. Therefore, a combination of the lip seal 23 and the bellows cap 8 constitutes an inner peripheral side seal mechanism 21, and the inner peripheral side seal mechanism 21 includes a combination lip seal 23 made of rubber. It is a rubber seal.

  Further, an annular protrusion-shaped stopper portion 27 is provided on the outer peripheral side of the seal mounting portion 22 on the inner surface of the oil port 5, and when the bellows cap 8 is lowered by the extension of the bellows 7, the bellows cap 8 is moved to its end surface. To contact the end surface (upper surface) of the stopper portion 27 to seal the backup fluid. Therefore, the combination of the oil port 5 provided with the stopper portion 27 and the bellows cap 8 constitutes the outer peripheral side seal mechanism 26, and both the combined parts of the outer peripheral side seal mechanism 26 are made of metal. From the metal seal.

  The end surface of the stopper portion 27 is formed in a funnel-shaped taper shape, and the end surface of the stopper portion 27 formed in the tapered shape is a contacted portion 27 a of the outer peripheral side seal mechanism 26. Further, the outer peripheral edge portion of the end surface of the bellows cap 8 is rounded with an arcuate cross section over the entire circumference, and the outer peripheral edge portion of the end surface of the bellows cap 8 that is rounded is the outer peripheral side. The contact portion 8a of the seal mechanism 26 is used. Accordingly, since the oil port 5 and the bellows cap 8 are easy to make a line contact over the entire circumference with the combination of the contacted portion 27a and the contact portion 8a and the contact surface pressure is set high, the metal seal is used. Nevertheless, excellent sealing performance can be exhibited. Instead of the roundness, an annular protrusion (convex portion) 8b as shown in FIGS. 4 and 5 may be provided at the contact portion 8a of the end face of the bellows cap 8. The cross-sectional shape of the protrusion 8b is also rounded.

  According to the accumulator 1 having the above-described configuration, the back-up fluid is prevented from flowing out by the inner and outer double seal mechanisms 21 and 26, so that the bellows 7 can be prevented from being damaged by the difference between the inner and outer pressures. In addition, since the outer peripheral seal mechanism 26 of the inner and outer double seal mechanisms 21 and 26 is a metal seal that makes metal contact with each other, it is less likely to be fatigued due to the characteristics of the material, and foreign matter bites, etc. Even if it exists, it has the characteristic that it is hard to wear out. Therefore, the accumulator 1 in which the durability of the inner and outer double seal mechanisms 21 and 26 that suppress the outflow of the backup fluid is improved can be provided as intended.

  The stopper portion 27 that forms the contacted portion 27a in the outer peripheral seal mechanism 26 is also a portion that functions as a stopper that stops the expansion of the bellows 7 when the bellows cap 8 comes into contact therewith. 6, the end surface of the stopper portion 27 may be formed in a flat shape as shown in FIG. 6, and the end surface of the bellows cap 8 that forms the contact portion 8 a may be formed in a flat shape. . Thus, even when the end face of the stopper portion 27 and the end face of the bellows cap 8 are both formed in a flat shape, it is an object of the present invention if each end face is formed smoothly and the backup fluid can be sealed at the time of both-side contact. This structure is included in the technical scope of the present invention because it can be achieved.

  Moreover, the following shapes may be sufficient as both end surfaces.

(1) As shown in FIG. 7, an annular projection (convex portion) 27b is provided on the end surface of the stopper portion 27, and the end surface of the bellows cap 8 formed in a planar shape is brought into contact with the projection 27b. In the drawing, the cross-sectional shape of the protrusion 27b is a square shape (triangular shape), but it may be a round shape (arc shape) as shown in FIG. 8, and the cross-sectional shape is not particularly limited. Moreover, it is good also considering the end surface of the bellows cap 8 as a taper surface.

(2) As shown in FIG. 9, an annular projection (convex portion) 8c is provided on the end surface of the bellows cap 8, and the projection 8c is brought into contact with the end surface of the stopper portion 27 formed in a planar shape. In the figure, the cross-sectional shape of the protrusion 8c is a square shape (triangular shape). However, as shown in FIG. 10, it may be a round shape (arc shape), and the cross-sectional shape is not particularly limited. Further, the end surface of the stopper portion 27 may be a tapered surface.

Next, the accumulator 1 shown in FIG. 11 has the same configuration as the accumulator 1 shown in FIGS. 1 to 3, and further has the following configuration.

  That is, a metal that melts at a predetermined temperature when an abnormally high temperature such as a fire occurs on an end surface of the stopper portion 27 in the oil port 5 that is the contacted portion 27a on the housing 2 side and on a part of the circumference thereof. A melting member 30 made of eutectic metal or the like or a resin is disposed flush with the end surface of the stopper portion 27. When the melting member 30 is melted by high heat such as a fire, the end surface of the stopper portion 27 is formed. In addition, a groove-like flow path communicating between the outer peripheral side (pressure inlet chamber 10 side) and the inner peripheral side (pressure inlet 18 side) of the stopper portion 27 appears. That is, the outer peripheral side (pressure inflow chamber 10 side) and the inner peripheral side (pressure inlet 18 side) of the stopper portion 27 are formed on a part of the circumference of the stopper portion 27 that is the contacted portion 27a. In order to fill the groove 31 for a while, a melting member 30 made of a metal (eutectic metal or the like) or resin that melts at a predetermined temperature when an abnormally high temperature such as a fire occurs is provided as a stopper. It is embedded in the same plane with respect to the end surface of the portion 27. The temperature at which the melting member 30 is melted is set to a temperature lower than the temperature at which other components such as the oil port 5 and the bellows cap 8 are reduced in strength, and is set to be equal to or lower than the temperature at which the lip seal 23 made of rubber-like elastic material is carbonized.

  In the accumulator 1 to which the above configuration is added, a groove portion 31 is provided on the end surface of the stopper portion 27 constituting the contacted portion 27a, and a melting member 30 such as metal or resin that melts at a predetermined temperature in the groove portion 31 is provided. Therefore, when a fire or the like occurs, the melting member 30 melts and a flow path by the groove portion 31 appears. When the flow path appears, the sealing function of the metal seal is lost even if the bellows cap 8 is in contact with the end surface of the stopper portion 27. In this state, the gas pressure in the bellows 7 rises as the temperature rises, and the bellows 7 Is expanded, the backup fluid in the pressure inflow chamber 10 is discharged from the pressure inlet 18 to the outside via the flow path (groove 31). Even if the bellows 7 is broken due to expansion, the sealed gas is discharged from the pressure inlet 18 through the flow path (groove 31). Therefore, in any case, since the pressure relief path by the flow path is formed by the melting of the melting member 30, the high pressure can be released to the outside, and thus the housing 2 can be prevented from being damaged by the high pressure. .

  In addition, as shown in FIG. 12, you may arrange | position the welding member 30 and the groove part 31 in the bellows cap 8 side which comprises the contact part 8a. Further, this structure may be added to any of the accumulators 1 shown in FIGS.

Sectional drawing of the accumulator which concerns on the Example of this invention The principal section expanded sectional view of the accumulator Part A enlarged view in FIG. Sectional drawing of the principal part of the accumulator which concerns on the other Example of this invention. Part B enlarged view in FIG. Sectional drawing of the principal part of the accumulator which concerns on the other Example of this invention. Sectional drawing of the principal part of the accumulator which concerns on the other Example of this invention. Sectional drawing of the principal part of the accumulator which concerns on the other Example of this invention. Sectional drawing of the principal part of the accumulator which concerns on the other Example of this invention. Sectional drawing of the principal part of the accumulator which concerns on the other Example of this invention. Sectional drawing of the principal part of the accumulator which concerns on the other Example of this invention. Sectional drawing of the principal part of the accumulator which concerns on the other Example of this invention. Cross section of accumulator according to conventional example Cross-sectional view of main parts of an accumulator according to another conventional example

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Accumulator 2 Housing 3 Shell 4 Gas end cover 5 Oil port 6 Actuating member 7 Bellows 8 Bellows cap 8a Contact part 8b, 8c, 27b Protrusion 9 Pressure sealing chamber 10 Pressure inflow chamber 11 Damping ring 12 Gas inlet 13 Gas plug 14 Hex Nut 15 Spacer 16 Mounting Portion 17 Screw Portion 18 Pressure Inlet Port 21 Inner Side Sealing Mechanism 22 Seal Mounting Portion 23 Lip Seal (Seal Member)
23a Base portion 23b Seal lip 24 Holder mounting portion 25 Seal holder 26 Outer peripheral side seal mechanism 27 Stopper portion 27a Contacted portion 30 Melting member 31 Groove portion

Claims (1)

A pressure sealing chamber (9) in which a predetermined pressure is sealed inside the housing (2) having a pressure inlet (18) by an operating member (6) having a bellows (7) and a bellows cap (8), and the pressure inlet When the pressure on the system side connecting to the accumulator (1) is reduced, the backup fluid in the pressure inflow chamber (10) flows out and the bellows is divided into the pressure inflow chamber (10) communicating with (18) In the accumulator (1) provided with the inner and outer double seal mechanisms (21) and (26) for suppressing the damage of (7),
A metal contact part (8a) provided on the bellows cap (8) is connected to a metal contact part (27a) provided on the inner surface of the housing (2). A metal seal that seals the backup fluid by abutting ,
A melting member (30) that melts at a specified temperature when an abnormally high temperature such as a fire occurs is disposed on a part of the circumference of the contacted part (27a) or a part of the circumference of the contact part (8a). An accumulator characterized by that.

Images