JP2010056507A - Pressure release valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pressure release valve easily manufacturable in a shape fittable in a small mounting space, keeping stable valve-opening pressure over a long period, and having no risk of slipping-out of a valve element from a groove part even if high valve-opening pressure is kept. <P>SOLUTION: The pressure release valve is arranged in a capacitor wrapped with a laminate film, and used for making the inside and outside of the laminate film communicate with each other when the pressure in the laminate film is set higher than a certain value. The pressure release valve comprises: a housing made of a resin material which is attached to an opening formed on the laminate film, and including an annular groove part opened to the outer side, and a communication hole for making the groove part communicate with the inside; and a valve element having a body part held to the bottom side of the groove part and a valve part extending toward the outer side from the body part and elastically contacting a circumferential surface of the groove part, and formed of a rubber-like elastic simple body. <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 a pressure release valve shown in FIG. 6 (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.

JP 2006-294669 A JP 2004-71725 A

  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 has an annular groove that opens to the outside, and a resin-made housing provided with a communication hole that communicates the groove with the interior; It has a main body portion that is held on the bottom side of the groove portion, and a valve portion that extends from the main body portion toward the outside and is in elastic contact with the outer peripheral surface of the groove portion. When the internal pressure becomes higher than a certain pressure, the valve portion and the outer peripheral surface are released from contact to release the internal pressure to the outside. Is.

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 release valve of the invention described in claim 3, it is possible to more reliably prevent the valve body from falling out of the groove portion.

Further, according to the pressure release valve of the invention described in claim 4, 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.
In addition, according to the pressure relief valve of the invention of claim 5, 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 6, since no adhesive is required, peeling due to deterioration of the adhesive due to an electrolyte or the like and contamination factors can be eliminated, and the laminate film and the housing are welded. Therefore, the manufacturing cost can be kept low.
According to the pressure release valve of the invention described in claim 7, it is easy to perform injection molding, and the valve body can be more reliably prevented from falling out of the groove.
Moreover, according to the pressure release valve of the invention of claim 8, the posture of the valve body can be correctly maintained.
Further, according to the pressure release valve of the ninth aspect of the invention, even when the pressure release valve becomes very small, injection molding is easy, and the valve body can be more reliably prevented from falling out of the groove portion. .
In addition, according to the pressure relief valve of the invention of the tenth aspect, it is possible to reliably prevent the internal electrolyte from flowing out to the valve body side.

Further, according to the pressure relief valve of the invention of the eleventh aspect, it is possible to prevent the gas-liquid separator from falling off even if there is a thermal influence.
Moreover, according to the pressure release valve of the twelfth aspect of the invention, it is possible to more reliably prevent the valve body from falling off.

Hereinafter, the best mode for carrying out the present invention will be described with reference to FIGS. 1 to 6. 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 further improvement of the first embodiment.
FIG. 4 is a cross-sectional view of a second embodiment of the pressure relief valve according to the present invention.
FIG. 5 is a cross-sectional view of a third embodiment of the pressure relief valve according to the present invention.
FIG. 6 is a cross-sectional view of a pressure release valve according to a fourth embodiment of the present invention.
FIG. 7 is a sectional view according to a fifth embodiment of the pressure relief valve of the present invention.
FIG. 8 is a sectional view according to a sixth embodiment of the pressure release 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 includes an annular groove 51 that is attached to the opening 4 provided in the laminate film 1 and opens to the outside Y side, and a communication hole 52 that communicates the groove 51 and the inside X.

As the material of the resin housing 5, a thermoplastic resin such as polyethylene or polypropylene is preferably used.
This makes it easy to integrate with the laminate film 1 by means such as ultrasonic welding.
Further, the communication hole 52 is formed with a columnar groove 521 in the center portion of the housing 5 from the inside X side, and the columnar groove 521 and the groove portion 51 are communicated with each other by notch portions 522 provided on the circumference at equal intervals. It has become.
The valve body 6 includes a main body portion 61 that is held on the bottom 53 side of the groove portion 51, and a valve portion that extends from the main body portion 61 toward the external Y side and elastically contacts the outer peripheral surface 551 of the groove portion 51. 62, and is composed of a rubber-like elastic body alone, and when the pressure in the internal X becomes higher than a certain pressure, the contact between the valve portion 62 and the outer peripheral surface 551 is released, and the pressure in the internal X is reduced to the external Y It is configured to open up to.

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.

And the end surface 54 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.
Further, a step 56 for retaining is provided on the inner peripheral surface 55 of the groove portion 51, which is in contact with the outer peripheral surface 63 of the body portion 61 of the valve body 6.
For this reason, a part of the main body portion 61 enters the step portion 56 side and prevents the valve body 6 from coming out of the groove portion 51.
As shown in FIG. 3, the retaining step 56 is provided on the outer peripheral surface 551 of the groove 51 and also on the portion where the inner peripheral surface 64 of the main body portion 61 of the valve body 6 is in contact with the valve body 6. 6 can be secured more securely.
In this case, a hole 521 is provided instead of the notch 522 in FIG. 2 so that the communication hole 52 can communicate the inner X and the outer Y.

<Second embodiment>
A second embodiment will be described with reference to FIG.
The difference from the first embodiment is that the gas-liquid separator 7 is inserted into the columnar groove 521 of the communication hole 52.
As the gas-liquid separator 7, a porous fluorine resin or the like that allows gas to pass but prevents the passage of the liquid is used.
This can reliably prevent the internal electrolyte from flowing out to the valve body side.
In addition, since a part of the outer peripheral surface of the gas-liquid separator 7 enters and is locked into the locking step portion 57 formed by the notch 522 of the communication hole 52, it is effective in preventing the gas-liquid separator 7 from coming off. It is.

<Third embodiment>
A third embodiment will be described with reference to FIG.
The difference from the second embodiment is that the gas-liquid separator 7 is attached to the end face 50 on the inner X side of the housing 5.
The gas-liquid separator 7 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 7, 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 50 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 7 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.

<Fourth embodiment>
A fourth embodiment will be described with reference to FIG.
The point that a retaining step 56 is provided on the inner peripheral surface 55 of the groove 51 in contact with the outer peripheral surface 63 of the main body 61 is the same as in the third embodiment. The third embodiment is different from the third embodiment in that the peripheral surface 64 is provided with a protrusion 65 in contact with the outer peripheral surface 551 and the protrusion 65 is provided with a passage 651 communicating from the internal X side to the external Y side.
Further, the locking step portion 57 formed by the notch portion 522 of the communication hole 52 provided in the third embodiment is not provided.
This makes injection molding easier than in the third embodiment, and the protrusion 65 prevents the valve body 6 from collapsing toward the inner diameter side, so that the sealing performance on the outer peripheral side of the valve body 6 can be maintained well. At the same time, the valve body can be more reliably prevented from falling out of the groove.
Further, the protrusions 65 are provided at equal intervals in the circumferential direction.
Thereby, the posture of the valve body can be correctly maintained.

<Fifth embodiment>
A fifth embodiment will be described with reference to FIG.
The difference from the third embodiment is that the outer peripheral surface 63 of the main body portion 61 is in close contact with the flat outer peripheral surface 55 of the groove 51, and the outer peripheral surface of the main body portion 61 is the same as the third embodiment. A step 56 for preventing the slipping is not provided at a portion in contact with 63.
Further, instead of the locking step portion 57 formed by the notch portion 522 of the communication hole 52 of the third embodiment, the locking protrusion 561 and the locking projection 561 from the inner X side to the outer Y side are provided. The difference is that a communication path 651 is provided.
The engaging projection 561 engages with the inner peripheral surface 64 of the main body portion 61, thereby preventing the valve body 6 from coming off to the outside Y side.
As a result, even if the pressure release valve becomes very small, injection molding is easy, and the valve body can be more reliably prevented from falling out of the groove.

<Sixth embodiment>
A sixth embodiment will be described with reference to FIG.
The difference from the first embodiment is that the main body portion 61 of the valve body 6 extends to the vicinity of the end surface 54 of the housing 5, and the end portion 59 of the columnar portion 58 surrounded by the groove portion 51 of the housing 5 extends to the vicinity of the end surface 54. It is growing.
And the laminate film 1 exists so that the groove part 51 and the columnar part 58 may be covered, and a part of laminate film 1 is integrated with the edge part 59 of the columnar part 58 by heat sealing | fusion.
A plurality of communication holes 11 are provided in a portion corresponding to the groove 51 of the laminate film 1.
This prevents the valve body 6 from coming out of the groove 51.

  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 the further improvement of 1st Example. 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 which concerns on 4th Example of the pressure relief valve which concerns on this invention. It is sectional drawing which concerns on 5th Example of the pressure relief valve which concerns on this invention. It is sectional drawing which concerns on 6th 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 Gas-liquid separator 50 End surface 51 Groove part 52 Communication hole 53 Bottom part 54 End surface 55 Inner peripheral surface 551 Outer peripheral surface 56 Step part 561 Locking protrusion 57 Locking Step portion 58 Columnar portion 59 End portion 61 Body portion 62 Valve portion 63 Outer peripheral surface 64 Inner peripheral surface 65 Projection

Claims (12)

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 relief valve (3) is attached to the opening (4) provided in the laminate film (1) and opened to the outside (Y) side, and the groove (51) A resin-made housing (5) having a communication hole (52) communicating with the interior (X), a main body portion (61) held on the bottom (53) side of the groove (51), It has a valve portion (62) extending from the main body portion (61) toward the outside (Y) side and in elastic contact with the outer peripheral surface (551) of the groove portion (51), and is composed of a rubber-like elastic body alone. When the internal (X) pressure becomes higher than a certain pressure, the contact between the valve part (62) and the outer peripheral surface (551) is released, and the internal (X) pressure is changed to the external (Y). A pressure relief valve comprising a valve body (6) adapted to be opened.   The end surface (54) of the housing (5) of the pressure release valve (3) and the inner (X) side surface near the opening (4) of the laminate film (1) are integrated by thermal fusion. The pressure relief valve according to claim 1, wherein the pressure relief valve is provided.   At least one of the inner peripheral surface (55) and the outer peripheral surface (551) of the groove portion (51) is detached from the portion where the outer peripheral surface (63) or the inner peripheral surface (64) of the main body portion (61) is in contact. The pressure relief valve according to claim 1 or 2, wherein a stop step (56) is provided.   A gas-liquid separator (7) is attached to the end face (50) 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 (7). The pressure release valve according to any one of claims 1 to 3, wherein the pressure release valve is prevented from flowing out to the side.   The pressure relief valve according to claim 4, wherein the gas-liquid separator (7) is a nonwoven fabric made of a thermoplastic resin material.   6. The pressure relief valve according to claim 5, wherein the gas-liquid separator (7) is held by welding on an end surface (50) on the inside (X) side of the housing (5).   A step portion (56) for retaining is provided at a portion of the inner peripheral surface (55) of the groove portion (51) that is in contact with the outer peripheral surface (63) of the main body portion (61). A protrusion (65) that contacts the outer peripheral surface (551) of the groove (51) is provided on the inner peripheral surface (64), and a passage (communication from the inner (X) side to the outer (Y) side of the protrusion (65) ( 651) is provided, The pressure release valve according to claim 1 or 2.   The pressure relief valve according to claim 7, wherein the protrusions (65) are provided at equal intervals in the circumferential direction.   The outer peripheral surface (63) of the main body portion (61) is in intimate contact with the flat outer peripheral surface (55) of the groove (51), and the locking protrusion is formed on the outer peripheral surface (551) of the groove (51). (561) and a passage (651) communicating from the inside (X) side to the outside (Y) side is provided, and the locking projection (561) is connected to the inner peripheral surface (64) of the main body portion (61). The pressure relief valve according to claim 1 or 2, wherein the valve body (6) is prevented from coming off to the outside (Y) side by engaging.   The pressure relief valve according to any one of claims 1 to 3, wherein a gas-liquid separator (7) is inserted into the communication hole (52).   An engagement step (57) for preventing the gas-liquid separator (7) from coming off is provided at a portion of the communication hole (52) that is in contact with the gas-liquid separator (7). 10. The pressure relief valve according to 10.   A columnar portion (58) in which the main body portion (61) of the valve body (6) extends to the vicinity of the end face (54) of the housing (5) and is surrounded by the groove portion (51) of the housing (5). The end (59) extends to the vicinity of the end surface (54), and a part of the laminate film (1) is integrated with the end (59) by heat fusion, thereby the valve body (6). The pressure release valve according to any one of claims 1 to 11, wherein the release of the pressure is prevented.

Images