TW200403876A - Safety valve structure of enclosed battery - Google Patents

Abstract

The invention provides a safety valve structure for enclosed battery with highly secure-valve-operation reliability, which can maintain enclosed battery at safe internal pressure for long time and can release the internal gas like Hydrogen with good accuracy while the internal pressure goes up. The resolution is to make the fluorine resin tiny powder 26 located between the mutual contact surfaces of the valve tube 21 and the valve body 22 in the safety valve structure of enclosed battery formed by penetrating the electric chamber cover 1 of the enclosed battery to install the cap rubber valve body 22 in the valve tube 21.

Description

200403876 (1) 发明. Description of the invention [Technical field to which the invention belongs] The present invention relates to the construction of safety valves for sealed batteries, and particularly to those who can keep sealed batteries at a stable internal pressure for a long time. Constructor of a safety valve for a sealed battery that releases a gas with good accuracy when the internal pressure rises. [Prior art] In the prior art, as shown in FIG. 3, a sealed battery is provided with a valve cylinder 2 1 penetrating through the electric tank cover 1 of the electric tank for storing power generation elements, and the valve cylinder 2 1 is formed as a valve hole for air permeability. 2 3. At the same time, the valve cylinder 2 1 has a safety valve structure 2 having a cap-shaped rubber valve body 22. In general, when the upper part of the valve body 2 2 in the electric tank cover 1 releases internal gas such as hydrogen generated by the electric tank, the valve body 2 2 has an upper cover 24 ′ which prevents the valve cylinder 21 from leaking to the outside. A gas exhaust port 25 is provided. In this sealed battery, a cap-shaped rubber valve body 22 mounted on the valve cylinder 21 generates hydrogen gas during charging of the battery, and when the internal pressure of the battery rises, the valve body 22 expands in the diameter direction and above, and then the valve cylinder 2 1 When gas is released from each other's space, when the internal pressure of the battery is lowered, the valve body 2 2 is closely adhered to the valve cylinder 21 to prevent air from flowing into the outside. The safety valve structure 2 of this sealed battery plays a very important role in the sealed battery. In other words, during the full use of a sealed battery with a long service life, the discharge performance of the battery is irrelevant, but the safety valve structure must operate normally. ′ It must maintain its safety and reliability for a long time. (2) (2) 200403876 In the closed battery safety-closing structure 2 of the foregoing prior art, when internal gas such as hydrogen in the battery is released from the gap between the valve cylinder 21 and the valve body 22, the sulfuric acid of the electrolyte leaks out, and this sulfuric acid Appears in the form of mist and gas at the same time. At this time, sulfuric acid adheres between the valve cylinder 21 and the cap-shaped rubber valve body 22, and when sulfuric acid adheres to the gap between the valve body 21 and the valve body 22, the cap-shaped rubber valve body 22 is liable to adhere to Valve cylinder 2; [especially at high temperature, after the sulfuric acid is concentrated, the surfaces of the valve cylinder 21 and the valve body 22 are eroded, which makes it easier to adhere. Also, as a material for forming the electric valve cylinder 21, ABS resin and polypropylene resin are used, and as a material for forming the valve body 2 2 made of rubber, it is mainly based on dicumyl peroxide. Synthetic rubbers such as ethylene-propylene-diene copolymer rubber (hereinafter referred to as "EP DM"), neoprene rubber, etc., which are formed by sulfuric acid, are used, and in this combination, the valve body 22 rubber unreacted group acts on the valve After the cylinder 21, it will also cause the cause of easy adhesion. In order to prevent the valve 22 from being easily adhered to the valve 21, it has been proposed to use fluorine rubber as the material for forming the rubber valve body 22. However, after the battery is used for a long time, even if the valve body 2 2 is formed of fluororubber, the valve body 22 may adhere to the valve body 22 under long-term use. In addition, the inner surface of the valve body 22 was also coated with polysiloxane oil. However, after the sulfuric acid was scattered in the polysiloxane oil, the main chain of the polysiloxane oil was cut to form a cyclic compound. Volatile substances (low-molecular-weight siloxane) evaporate. Therefore, the lubricity between the valve cylinder 21 and the valve body 22 is reduced, which causes the valve body 22 to expand and be difficult to open. Due to the above problems, the function of the safety valve structure 2 cannot be operated normally. (3) (3) 200403876 As the internal pressure of the battery rises, the electric tank expands and ruptures, and the valve cylinder 2 and the valve body 2 cannot maintain each other. The tightness makes it easy for air to penetrate into the battery when the internal pressure of the battery drops. At the same time as sulfuric acid is oxidized, after the cathodic oxidation, the self-discharge becomes larger, the lattice corrosion becomes larger, and the problem of shortened battery life occurs. [Summary of the Invention] The object of the present invention is to provide a person who can solve the problems of the prior art sealed battery safety valve structure, and can keep the sealed battery at a safe internal pressure for a long time. A safety valve for sealed batteries that releases internal gas such as hydrogen gas with high accuracy and reliability. In order to achieve the above object, a feature of the safety valve structure for a sealed battery of the present invention is that a fluorine valve is used in the structure of the safety valve for a sealed battery, which is formed by penetrating the valve cover of the sealed battery and formed with a cap-shaped rubber valve body. The resin fine powder is interposed between the contact surface of the valve cylinder and the valve body. This sealed battery safety valve structure allows the sealed battery to maintain a safe internal pressure for a long period of time, and at the same time, when the internal pressure of the battery rises, it can release internal gas such as hydrogen with high accuracy, and it has high operational reliability. In this case, it can be applied to the fluororesin fine powder in which the device is dispersed in a liquid medium and the valve body in front of the valve cylinder. Therefore, an appropriate amount of the fine fluororesin fine powder is uniformly dispersed on the contact surface between the valve body and the valve cylinder, and it is applicable. In addition, the fluororesin fine powder mixed in the liquid medium can be made into 1 to 50% by weight. -7- (4) (4) 200403876 With this, the liquid medium in the state of finely dispersed fluororesin can be easily applied to the valve body. Further, a fluorine-based oil can be used as the liquid in which the fine fluororesin powder is dispersed. This is because those who can maintain stable lubricity even after long-term use. At the contact portion between the valve cylinder and the valve body, a concave portion can be formed which is kept in a state of being dispersed in the liquid medium state by the fluororesin fine powder. With this, the amount of fluororesin fine powder dispersed in the liquid medium is increased while preventing the outflow, and the fluororesin fine powder dispersed in the liquid medium can be stably maintained for a long period of time at the contact portion between the valve cylinder and the valve body. It also improves the operational reliability of the sealed battery safety valve structure. [Embodiment] Hereinafter, an embodiment of a safety valve structure for a sealed battery according to the present invention will be described with reference to the drawings. Fig. 1 shows an example of an embodiment of a safety valve structure for a sealed battery according to the present invention. This closed-type battery safety valve structure is formed by inserting a valve-cylinder cover 1 formed in the closed-cell battery cover 1 into a closed-type safety valve structure 2 for a closed-type battery, which includes a cap-shaped rubber valve body 22 in the sealed battery. The powder 26 is interposed between the valve body 21 and the valve body 2 2 in contact with each other. At this time, the fluororesin fine powder 2 between the contact surface of the valve cylinder 2 1 and the valve body 2 2 can be used arbitrarily as long as it is a fine powder of polytetrafluoroethylene or its denatured polymer. 1 // m ~ 20 // m are not particularly limited. (5) 200403876 Fine fluororesin powder 26 is suitable for those who are suitable for dispersing in liquid media. At this time, any lubricant such as fluorine-based oil, silicone oil or rapeseed oil can be used as the liquid media. At this time, the fluororesin fine powder 26 is preferably mixed in a liquid medium at 1 to 50% by weight, and more preferably at 1 to 30% by weight. If the mixing ratio of the fluororesin fine powder 26 exceeds 30% by weight, the viscosity of the dispersion liquid will increase, and the dispersion liquid will not be easily applied to the contact surface between the valve cylinder 21 and the valve body 22, and if it exceeds 50%, the dispersion liquid The applicability is even more difficult. One of the most ideal liquids using fluororesin fine powder 2 6 as a dispersion medium is a fluorine-based oil, which has heat resistance, nonflammability, and oxidation resistance. As a typical example of a fluorine-based oil, such as a fluorine-based oil having the following chemical structure, it is not limited to this chemical structure. A fluorine-based oil having the following chemical structure is a low-molecular-weight hexafluoropropylene epoxy group, a homopolymer terminated with fluorine at the end, a polymer chain completely saturated, and composed of carbon, oxygen, and fluorine. F — (― CF — CF2 —〇 一) n —CF2CF3 CF3 7 ~ 6 0 In this way, when using a fluorine-based oil as the medium for dispersing the fluororesin fine powder 2 6, depending on the type of rubber constituting the valve body 22, fluorine appears. The amount of fluorine-based oil that is adsorbed on the contact surface of the valve cylinder 21 and the valve body 22 is reduced, and the lubricating performance is reduced due to the fluorine-based oil. In order to prevent this phenomenon, the rubber valve body 22 is immersed in a fluorine-based oil for a predetermined time (not particularly limited, generally several weeks) in advance, and after the valve body 22 has fully absorbed the oil, it is suitable to mix fine fluorine resin powder. 26 Fluorine oil is suitable for -9- (6) 200403876 valve body 22.

Also, as an example of an ideal liquid for dispersing the fluororesin fine powder 26, such as silicone oil. Polysiloxane has heat resistance, nonflammability, and oxidation resistance up to a certain temperature. The typical polysiloxane oil is a polydimethylsiloxane with the following chemical structure, the main chain is a siloxane bond, and the side chain is a methyl group. Therefore, at high temperatures, mixing with acid and alkali increases the viscosity. Gelation occurred. However, in the structure of the safety valve for a sealed battery according to the present invention, the fluororesin fine powder 26 is interposed between the valve cylinder 21 and the valve body 22, so that the valve cylinder 21 and the valve body 22 are not adhered to each other. In addition, it is an ideal liquid as a medium for dispersing fluororesin fine powder 26. Examples include rapeseed oil. Rapeseed oil has insufficient inherent heat resistance. However, when the fluororesin fine powder 26 is used as a dispersion medium in the safety valve structure of the sealed battery of the present invention, the fluororesin fine powder 26 is interposed between the valve cylinder 21 and the valve body. Therefore, the valve cylinder 21 and the valve body 22 are not adhered to each other.

CH3 CH3 ~ Si —〇 CHa / CH3 \ one Si — 〇-

I

kCHa J CHs

Si—CH3

I CH3 Hereinafter, the operation of this closed battery safety valve structure 2 will be described with reference to the drawing. Sealed battery with closed cap safety valve structure 2 in valve cylinder 21 formed with valve cap 21 formed by penetrating trough cover 1 and equipped with a cap-shaped rubber valve body 2 The internal pressure of the battery rises when hydrogen gas is generated during charging Above a certain pressure -10- (7) (7) 200403876, the cap-shaped rubber valve body 22 expands in the diameter direction and above, expands to form a gap with the valve cylinder 21, and then releases the gap. Out of the internal gas such as hydrogen. When the internal pressure of the battery is lowered, the cap-shaped rubber valve body 2 2 is closely adhered to the valve cylinder 21 to prevent air from flowing in from the outside. At this time, the hydrogen generated in the battery is released from the gap between the valve cylinder 21 and the valve body 22, and the sulfuric acid of the electrolyte leaks out in the gap between the valve cylinder 21 and the valve body 22. This sulfuric acid is in the form of a mist with the gas. Even if sulfuric acid adheres to the contact surface of the valve cylinder 21 and the valve body 22, the fluororesin fine powder 26 is interposed between the valve cylinder 2 1 of the safety battery structure 2 for a sealed battery of the present invention and the valve body 2 made of a rubber cap Therefore, it is difficult to make the cap-shaped rubber valve body 2 2 adhere to the valve cylinder 2 1, and even after the sulfuric acid is concentrated at high temperature, the surfaces of the valve cylinder 2 1 and the valve body 2 2 are slightly eroded, the battery life thereof The sticking of the valve cylinder 21 and the cap-shaped rubber valve body 2 2 can be prevented for the extended time. In addition, the safety valve structure 2 of the present invention, which is provided in a sealed battery, usually prevents the release of hydrogen gas generated by the electric tank, and the cap-shaped rubber valve body 2 2 leaks upward from the valve cylinder 2 1, and the upper cover 2 4 A slight gap is formed between the valve body 22 and the upper surface of the valve body 22, and after the gas exhaust port 25 is provided on the upper cover 24, internal gas such as hydrogen is released from the gas exhaust port. This safety valve structure 2 for a sealed battery of the present invention has the fluororesin fine powder 26 interposed between the valve cylinder 2 1 and the valve body 2 2 in contact with each other. Therefore, the reliability and safety of the battery can be used by Director O. Nakada. By. In the sealed battery safety valve structure 2 of the present invention, the concave portion of the fluorine resin fine powder that maintains a predetermined amount of dispersion in the liquid medium can be formed in the contact portion between the valve cylinder 2 and the valve body 22. -11-200403876 The place where the recessed portion is formed and the shape of the recessed portion are not particularly limited. Generally, as shown in FIG. 2 (a), a groove-shaped recessed portion 22 a is formed on the inner periphery of the valve body 2 2 which is in contact with the valve cylinder 21. More specifically, an inner trench with a width of 0.5 to 5 mm and a depth of 0.05 to 0.5 mm is formed from 1 to a plurality (2 in the illustrated embodiment), as shown in FIG. 2 (b). A groove-shaped recess 2 I a is formed on the periphery of the valve cylinder 2 1 that is in contact with the valve body 2 2. More specifically, one to a plurality (two in the illustrated embodiment) is formed. The width is 0 · 5 to 5 mm. Deep grooves of 0. 〇5 to 1 · 〇 mm, more than the cylinder barrel 2 1 and the valve body 2 2 can form the same recessed part ® 〇 By configuring the valve in this way 2 1 and the valve body 2 2, It can increase the holding amount of the fluororesin fine powder dispersed in the liquid medium and prevent it from flowing out. The contact portion of the valve cylinder 21 and the valve body 22 can keep the resin fine powder dispersed in the liquid medium stable for a long time. , Can further improve the operational reliability of the closed battery safety valve structure. [Embodiment] Φ The following is a description of the content and effect of the present invention by taking the embodiment as an example, without being limited to the description of the embodiment. The present invention does not exceed the scope of the present invention [Comparative Examples 1 to 4, Examples 1 to 14]

The structure shown in FIG. 1 is π and…, and the j-shaped rubber valve body 22 -12- (9) (9) 200403876 is evaluated under the following conditions. Among them, the valve body 2 made of cap-shaped rubber uses chloroprene rubber (CR) and ethylene propylene diene copolymer rubber (ePD) V [) (size = height: 7 mm, inner diameter: 1 1.9 mm, outer diameter: 13.8 mm, initial thickness: 1.1 mm). In the case where the sulfuric acid is mixed with the coating material, the state of sulfuric acid mixed into the battery electrolyte is reappeared. The results obtained are shown in Table 1. From the results below, it was proved that in the comparative example in which ①polysiloxane oil and sulfuric acid, or ②fluorine oil and sulfuric acid were applied to the cap-shaped rubber valve body 22, poor lubrication occurred after 1 month, and After mixing ① fluororesin fine powder and sulfuric acid, ② fluororesin fine powder and sulphuric acid in a fluorine-based oil, or ③ polysilicone oil mixed fluororesin fine powder and sulphuric acid, respectively, after coating, the fluororesin fine powder is interposed between When the cylinder 21 and the valve body 2 are in contact with each other, the lubricity does not decrease. (1) fluororesin fine powder: average particle size 2 β m (2) coating material A: polysiloxane oil and ethyl sulfate: fluorine-based oil and propylene sulfate: fluororesin fine powder mixed with butyl sulfate and wind-based oil 10% resin micropowder powder mixed with pentyl sulfate: fluorine-based oil 20% fluororesin micro powder mixed with hexane sulfate: fluorine-based oil 30% fluororesin micropowder mixed with heptyl sulfate: polysiloxane oil 1 〇 % Fluororesin fine powder mixed with octyl sulfate: 20% fluororesin fine powder mixed with sulfuric acid-13- 200403876 do) Ren: polysiloxane resin mixed with 30% fluororesin fine powder and sulfuric acid [lubricity Evaluation] After the following coating materials were applied to the rubber valve body 22, the valve cylinder 21 of the safety valve structure 2 molded from AB S resin was installed. The experimental atmosphere was made at room temperature, and the lubricity of the device was evaluated after 1 month, 2 months, and 3 months. The evaluation of lubricity is based on the fingertip grasping device on the valve body 2 2 of the valve cylinder 2 1 to evaluate the ease of rotation. It is made into 3 stages (0) good rotation, (△) slightly resistant to rotation, ( X) Evaluation of lubricity that is sticky and cannot rotate. The average of the three evaluations was taken.

-14- (11) 200403876 [Table 1] When the material lubricity device of the coating material valve body is 1 month, 2 months, and 3 months later, Comparative Example 1 A CR 〇Δ XX Comparative Example 2 BCR 〇Δ Δ Δ Example 1 Prop CR 0000 Example 2 Prop CR 10000 Example 3 P CR 10000 Example 4 HCR CR 5000 Example 5 HCR CR 10000 Example 6 Example 7 Non-CR 0000 Comparative Example 3 EPDM 〇〇Δ Comparative Example 4 EPDM 〇Δ Δ Δ Example 8 Prop EPDM 0000 Example 9 But EPDM 0000 Example 10 Example EPDM 0000 Example 11 Example EPDM 0000 Example 12 Example EPDM 0000 Example 3 Example EPDM 0000 Example 14 Example EPDM 0000 [Inventive effect] This The invention of a sealed battery safety valve structure can keep the sealed battery at -15- (12) (12) 200403876 at a long-term safe internal pressure. At the same time, when the internal pressure of the battery rises, it can release internal gas such as hydrogen with good accuracy. Extremely high security The reliability of valve construction. In more detail, the internal gas such as hydrogen generated in the battery is released by the valve cylinder and the valve body, and the sulfuric acid that leaks out of the electrolyte in the gap between the valve cylinder and the valve body is sprayed with the gas together with the gas, even if sulfuric acid is attached to the The contact surface between the valve body and the valve cylinder is interposed between the valve cylinder of the sealed type ® and the safety valve structure of the present invention and the valve body made of a rubber cap by means of a fluororesin fine powder. S 1 Gastric cap type rubber valve The body adheres to the valve cylinder, and the sulfur @ ®Concentrated under high temperature # Even if the surface of the valve cylinder and the valve body is slightly eroded, its battery life ^% β prevents the valve cylinder and the cap-shaped rubber valve body from sticking to each other. With. In addition, the fluororesin fine powder dispersed in the liquid medium is suitable for the valve body before the valve body is installed, and an appropriate amount of the fluororesin fine powder is uniformly dispersed on the contact surface between the valve body and the valve body. After the fluororesin fine powder mixed in the liquid medium is made into 1 to 50% by weight, the liquid medium in which the fluororesin fine powder is dispersed can be easily applied to a valve body. In addition, the stable lubricity can be maintained for a long period of time by using a stable fluorine-containing oil in a liquid in which the fine powder of the fluororesin is dispersed. After the concave portion of the fluororesin fine powder remaining dispersed in the liquid medium is formed at the contact portion between the valve cylinder and the valve body, the retention amount of the fluororesin fine powder dispersed in the liquid medium can be increased, and at the same time, it can be prevented from flowing out. The fluororesin fine powder dispersed in the liquid medium can be stably maintained for a long time, and the reliability of the structure and operation of the safety valve for sealed batteries can be improved. [Brief description of the drawings] -16- (13) (13) 200403876 [Fig. 1] A longitudinal section showing an example of the implementation form of the safety valve structure for a sealed battery of the present invention. [Fig. 2] A longitudinal section showing a modified example of the embodiment of the structure of the safety valve for a sealed battery according to the present invention. [Fig. 3] A longitudinal section showing an example of an implementation form of a safety valve for an advanced sealed battery. [Comparison table of main components] 1 Electric tank cover 2 Safety valve structure for sealed battery 2 1 Valve cylinder 22 Valve body 23 Valve hole 24 Upper cover 25 Gas outlet 26 Fine fluorine resin powder -17-

Claims (1)

(1) (1) 200403876 Scope of application and patent application 1. A closed type safety valve structure for a battery, which is a valve body made of a cap-shaped rubber in a valve cylinder formed after penetrating the electric tank cover of the closed type battery. The structure of the safety valve for the battery is characterized in that the fluororesin fine powder interposes the valve cylinder and the valve body in contact with each other. 2 · The structure of a safety valve for a sealed battery, as described in item 1 of the scope of patent application ′, where the structure is to apply the fine fluororesin powder dispersed in a liquid medium to the valve body in front of the valve cylinder of the device. 3 · The structure of a safety valve for a sealed battery according to item 2 of the scope of patent application ′ wherein the structure is mixed with 1 to 50% by weight of fluororesin fine powder in a liquid medium. 4 · If the sealed battery for the second or third item of the scope of the application for the patented structure, the liquid is a fluorine-based oil. 5 · If the scope of the patent application is No. 2, 3 or 4, the closed type electric 'valve safety valve structure' in which the contact portion of the valve cylinder and the valve body forms a fluororesin microparticles which is kept dispersed in the liquid medium. Recessed portion of powder.