JP2010056501A - Pressure relief valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pressure relief valve which can be readily manufactured into a form that a small attachment space can accommodate for maintaining a stable relief valve pressure for a long time, and without the risk of a valve body slipping out of a groove part, even if a high relief valve pressure is maintained. <P>SOLUTION: In a pressure relief valve provided in a capacitor wrapped by a laminated film and which causes its inside and outside to communicate with each other, when the pressure inside the laminated film becomes higher than a fixed pressure, the pressure relief valve includes a housing made of resin material and is attached to an opening provided in the laminated film and which comprises: a through-hole; a valve body arranged within the through-hole and having a body part; a valve part that extends from the body part toward the outside and elastic contact with the inner circumferential surface of the through-hole of the housing; and an engaging means for holding the body part on the side of the housing. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

The present invention relates to a pressure relief valve.
The present invention also relates to a pressure release valve that is provided in a capacitor packaged with a laminate film and communicates between the inside and the outside when the pressure inside the laminate film becomes higher than a certain pressure.
Furthermore, the present invention relates to a pressure release valve that quickly releases the internal pressure when the pressure inside the laminate film increases.

  In recent years, capacitors are strongly required to be light and thin. Therefore, the battery exterior material can be further reduced in weight and thickness in place of conventional metal cans that are limited in weight and thickness, and can have a free shape compared to metal cans. A metal thin film or a laminate film in which a metal thin film and a heat-fusible resin film are laminated has come to be used.

  A typical example of a laminate film used as a capacitor exterior material is to laminate a heat-sealable resin film as a heat seal layer on one side of an aluminum thin film as a metal thin film and a protective film on the other side. The laminated film which was made is mentioned.

In a film-clad capacitor using a laminate film as a packaging material, an electrochemical element generally composed of a positive electrode, a negative electrode, an electrolyte, and the like is surrounded by a packaging material with the heat-fusible resin film on the inside. The electrochemical element is sealed by heat-sealing the peripheral edge of the exterior material.
For example, a polyethylene film or a polypropylene film is used as the heat-fusible resin film, and a nylon film or a polyethylene terephthalate film is used as the protective film, for example.
When sealing the electrochemical element, external terminals are connected to the positive electrode and the negative electrode, respectively, so that the positive electrode and the negative electrode of the capacitor are drawn out of the outer packaging material, and these external terminals protrude from the outer packaging material.

When a voltage outside the standard range is applied to the capacitor when the capacitor is used, heat and gas species are generated due to electrolysis of the electrolyte solvent, and the battery temperature and internal pressure may increase.
Furthermore, even if the capacitor is used at a high temperature outside the standard range, a substance that is a source of gas species is generated due to decomposition of the electrolyte salt or the like.

Such generation of gas inside the capacitor causes an increase in the internal pressure of the capacitor.
In a film exterior capacitor, if the internal pressure increases too much, the film expands and eventually the exterior material may rupture, which may adversely affect surrounding equipment.

  Therefore, a conventional film-covered capacitor is known in which a pressure release valve for releasing the internal pressure to the outside is provided.

Specifically, it is the pressure release valve shown in FIG. 5 (Patent Document 1).
A capacitor is packaged with a laminate film 100, and a pressure release valve 300 is attached to an opening 400 provided in the laminate film 100.
This pressure release valve 300 has a configuration in which an oil seal type valve body 600 is fitted in a groove 510 provided in a resin-made housing 500.

The valve body 600 is embedded with a metal reinforcing ring 640 so that the valve body 600 does not fall out of the groove portion 510.
Further, a coil spring 660 is disposed on the lip portion 650 that functions as a valve portion.
However, it has been very difficult to manufacture the pressure release valve 300 having such a structure so as to fit in a mounting space of less than 1 cm.

Therefore, a pressure release valve using a valve body composed of a single rubber-like elastic body has been proposed (Patent Document 2).
However, since the valve body is a slit part formed in the rubber tip part and is held in the groove part by the thin main body part, the sealing performance is inferior, and there is a risk that moisture enters the inside from the outside. At the same time, it was not possible to provide a high valve opening pressure release valve, and there was a risk that the valve body could easily come out of the groove.

Japanese Patent Laid-Open No. 2006-294669 Japanese Patent Laid-Open No. 2004-71725

  The present invention has been made in view of such problems, and can be easily manufactured in a form that fits in a small mounting space, and can maintain a stable valve opening pressure over a long period of time. And even if it maintains a high valve opening pressure, it aims at providing the pressure relief valve without the danger that a valve body will slip out from a groove part.

The pressure release valve of the present invention is provided in a capacitor packaged with a laminate film, and when the internal pressure of the laminate film is higher than a certain pressure, the pressure release valve communicates the inside and the outside.
The pressure relief valve is attached to an opening provided in the laminate film and is disposed in the resin material housing having a through hole, and is disposed in the through hole. And has a valve portion elastically in contact with the inner peripheral surface of the through hole of the housing, and a locking means for holding the main body portion on the housing side, and is composed of a rubber-like elastic body alone. And a valve body that releases the internal pressure to the outside by releasing the contact between the valve portion and the inner peripheral surface when the internal pressure becomes higher than a certain pressure. To do.

The present invention has the following effects.
According to the pressure relief valve of the first aspect of the invention, the pressure relief is easy to manufacture in a form that fits in a small mounting space, and there is no risk of the valve body coming out of the groove portion even if a high valve opening pressure is maintained. A valve can be provided.
Moreover, according to the pressure release valve of the invention of claim 2, the pressure release valve can be easily attached to the laminate film side.

Furthermore, according to the pressure relief valve of the invention described in claim 3, it is possible to more reliably prevent the valve body from falling out of the through hole.
According to the pressure relief valve of the invention described in claim 4, the inside and the outside can be communicated with each other with a simple structure.

Moreover, according to the pressure release valve of the invention described in claim 5, since the gas-liquid separator is attached to the end face on the inner side of the housing, the pressure release valve can cope with a very small pressure release valve. Is possible.
Moreover, according to the pressure relief valve of the invention of claim 6, since the electrolytic solution scattered by the nonwoven fabric can be collected, it is possible to effectively eliminate the electrolytic solution from eroding the valve portion, and the housing and the gas-liquid separator. Is easy to integrate.

Further, according to the pressure release valve of the invention of claim 7, since no adhesive is required, peeling due to deterioration of the adhesive due to an electrolyte or the like, and contamination can be eliminated, and the laminate film and the housing are welded. Therefore, the manufacturing cost can be kept low.
Further, according to the pressure relief valve of the eighth aspect of the invention, it is possible to more reliably eliminate liquid leakage from the inner side to the outer side of the housing.

Moreover, according to the pressure release valve of the ninth aspect of the invention, it is possible to reliably prevent the internal electrolyte from flowing out to the valve body side.
Further, according to the pressure release valve of the invention of the tenth aspect, it is possible to prevent the valve body from dropping out to the inner side.
Moreover, according to the pressure release valve of the invention of claim 11, the valve portion is not damaged.

Hereinafter, the best mode for carrying out the present invention will be described with reference to FIGS. 1 to 3. FIG.
FIG. 1 is an overall view of a capacitor to which the present invention is applied.
FIG. 2 is a cross-sectional view of a first embodiment of the pressure relief valve according to the present invention.
FIG. 3 is a sectional view according to a second embodiment of the pressure relief valve according to the present invention.
FIG. 4 is a cross-sectional view of a third embodiment of the pressure relief valve according to the present invention.

<First embodiment>
1 and 2, the pressure relief valve according to the present invention is provided in a capacitor 2 packaged with a laminate film 1, and when the pressure inside X of the laminate film 1 becomes higher than a certain pressure, A function of communicating X and external Y is provided.
The pressure release valve 3 includes a resin material housing 5 and a valve body 6.
The housing 5 is attached so as to surround the opening 4 provided in the laminate film 1 and is made of a resin material and includes a through hole 51.

And as a material of the housing 5, thermoplastic resins, such as polyethylene and a polypropylene, are used preferably.
This makes it easy to integrate with the laminate film 1 by means such as ultrasonic welding.
The valve body 6 is disposed in the through hole 51, extends from the main body portion 61 toward the outside Y side, and elastically contacts the inner peripheral surface 52 of the through hole 51 of the housing 5. Portion 62 and a locking means 63 for holding the main body portion 61 on the housing 5 side, and is formed of a single rubber-like elastic body. When the pressure inside X becomes higher than a certain pressure, the valve portion The structure is such that the contact between 62 and the inner peripheral surface 52 is released, and the pressure inside X is released to outside Y.

The locking means 63 is formed on the inner X-side outer peripheral surface of the main body portion 61 by a protrusion 631 that abuts on the inner X-side end surface 53 of the housing 5.
Further, the protrusion 631 is provided with a plurality of notches 632 on the circumference so that the inner X side and the outer Y side can communicate with each other.
Further, a gap 8 is formed between the outer peripheral surface and the inner peripheral surface 52 of the main body portion 61 for forming the communication path 7 for communicating the inside X and the outside Y.
As a result, communication between the internal X and the external Y is ensured.

Further, a receiving portion 54 that protrudes radially inward is provided on the inner peripheral surface 52 side of the housing 5 and on the inner X side from the valve portion 62.
The receiving portion 54 is a conical surface 541 that converges toward the inner X side.
As a result, the valve body 6 can be prevented from falling off to the inside X side, and the valve portion 62 is not damaged.

  Examples of the material of the valve body 6 include saturated rubbers such as butyl rubber, halogenated butyl rubber, vinyl-modified butyl rubber, ethylene propylene rubber, fluorine rubber, acrylic rubber, or hydrogenated nitrile rubber, and include crosslinking agents, fillers, and plasticizers. Or an antiaging agent etc. are mix | blended suitably.

The laminate film 1 is a laminate film in which a heat-sealable resin film as a heat seal layer is laminated on one side of an aluminum thin film that is a metal thin film, and a protective film is laminated on the other side.
For example, a polyethylene film or a polypropylene film is used as the heat-fusible resin film, and a nylon film or a polyethylene terephthalate film is used as the protective film, for example.

  Then, the end surface 55 of the housing 5 of the pressure release valve 3 and the surface on the inner X side in the vicinity of the opening 4 of the laminate film 1 are integrated by heat fusion such as ultrasonic welding.

<Second embodiment>
A second embodiment will be described with reference to FIG.
The difference from the first embodiment is that a gas-liquid separator 9 is inserted into a part of the communication path 7.
As the gas-liquid separator 9, a porous fluorine resin or the like that allows gas to pass but prevents liquid from passing therethrough is used.
This can reliably prevent the internal electrolyte from flowing out to the valve body side.
Further, a cylindrical holding projection 91 extending along the inner peripheral surface of the receiving portion 54 is integrally provided on the outer peripheral side of the gas-liquid separator 9 on the outer Y side end.
This holding projection 91 can prevent the gas-liquid separator 9 from falling out of the housing 5.
In addition, it is not always necessary to provide the notch 632 in the projection 631 as the locking means 63 of the present embodiment as in the first embodiment.

<Third embodiment>
A third embodiment will be described with reference to FIG.
The difference from the second embodiment is that the gas-liquid separator 9 is attached to the end face 53 on the inner X side of the housing 5.
The gas-liquid separator 9 prevents the liquid on the inner X side from flowing out to the outer Y side.
For this reason, as compared with the second embodiment, it is possible to cope with even a very small pressure release valve.

Moreover, as a raw material of the gas-liquid separator 9, the nonwoven fabric made from thermoplastic resin materials, such as polyethylene, a polypropylene, a polyvinyl chloride, a polystyrene, is used suitably.
For this reason, since the electrolyte solution scattered by the nonwoven fabric can be collected, it is possible to effectively eliminate the electrolyte solution from eroding the valve portion 62. By using the nonwoven fabric made of the thermoplastic resin material, It can be integrated with the end face 53 on the inner X side of the housing 5 by welding.
As a result, no adhesive is required, so it is possible to eliminate peeling and contamination due to deterioration of the adhesive, and to be integrated in the same process as the welding of the laminate film and the housing, so the manufacturing cost is kept low. I can do it.

  Furthermore, since the surface of the gas-liquid separator 9 is treated with a water- and oil-repellent agent such as fluorine or silicon, liquid leakage from the inside to the outside of the housing can be more reliably eliminated.

  The present invention is not limited to the best mode for carrying out the invention described above, and various other configurations can be adopted without departing from the gist of the present invention.

1 is an overall view of a capacitor to which the present invention is applied. It is sectional drawing which concerns on 1st Example of the pressure relief valve which concerns on this invention. It is sectional drawing which concerns on 2nd Example of the pressure relief valve which concerns on this invention. It is sectional drawing which concerns on 3rd Example of the pressure relief valve which concerns on this invention. It is sectional drawing of the pressure relief valve which concerns on a prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Laminate film 2 Capacitor 3 Pressure release valve 4 Opening part 5 Housing 6 Valve body 7 Communication path 8 Gap 9 Gas-liquid separation body 51 Through-hole 52 Inner peripheral surface 53 End surface 54 Receiving part 55 End surface

Claims (11)

When the internal pressure (X) of the laminate film (1) is higher than a certain pressure, the internal (X) and external (Y) are provided on the capacitor (2) wrapped with the laminate film (1). In the pressure release valve (3) for communicating with
The pressure release valve (3) is attached to an opening (4) provided in the laminate film (1), and is made of a resin material housing (5) having a through hole (51), and the through hole (51). ), Extending from the main body portion (61) toward the outside (Y) side, and elastic with the inner peripheral surface (52) of the through hole (51) of the housing (5). It has a valve part (62) that is in contact and a locking means (63) for holding the main body part (61) on the housing (5) side, and is composed of a rubber-like elastic body alone, When the pressure of (X) becomes higher than a certain pressure, the contact between the valve part (62) and the inner peripheral surface (52) is released, and the pressure inside (X) is released to the outside (Y). A pressure relief valve comprising the valve body (6) configured as described above.   The pressure relief valve according to claim 1, wherein an end face (55) on the outside (Y) side of the housing (5) and the laminate film (1) are integrated by heat fusion.   The locking means (63) is a protrusion (631) that contacts the inner (X) side end surface (53) of the housing (5) on the inner (X) side outer peripheral surface of the main body portion (61). The pressure release valve according to claim 1 or 2, wherein   A gap (8) for forming a communication path (7) for communicating the inside (X) and the outside (Y) between the outer peripheral surface of the main body portion (61) and the inner peripheral surface (52). The pressure relief valve according to any one of claims 1 to 3, wherein:   A gas-liquid separator (9) is attached to an end face (53) on the inside (X) side of the housing (5), and the liquid on the inside (X) side is externally (Y) by the gas-liquid separator (9). The pressure release valve according to any one of claims 1 to 4, wherein the pressure release valve is prevented from flowing out to the side.   6. The pressure relief valve according to claim 5, wherein the gas-liquid separator (9) is a nonwoven fabric made of a thermoplastic resin material.   The pressure relief valve according to claim 6, wherein the gas-liquid separator (9) is held by welding on an end surface (53) on the inside (X) side of the housing (5).   The pressure release valve according to claim 6, wherein the surface of the gas-liquid separator (9) is subjected to water repellent treatment.   The pressure relief valve according to claim 4, wherein a gas-liquid separator (9) is inserted into a part of the communication passage (7).   A receiving portion (54) projecting radially inward is provided on the inner peripheral surface (52) side of the housing (5) on the inner (X) side from the valve portion (62). The pressure release valve according to any one of claims 1 to 9.   The pressure relief valve according to claim 10, wherein the receiving part (54) has a conical surface (541) converging toward the inside (X) side.

Images