JP2016157570A - Sealing plate, manufacturing method of sealing plate and sealed battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sealing plate having a highly reliable safety valve capable of satisfying both of durability against repeated stress due to an inner pressure smaller than an allowable pressure and the stability reliably opened by an operation pressure.SOLUTION: A sealing plate 3 has a plate part 3A and a safety valve 3B. The safety valve 3B is integrally formed with a part of the plate part 3A. The safety valve 3B includes: an outer concave 301; an inner concave 302; an outer periphery bent part 303; at least two hatch part 304; a ligament part 305; a first peripheral groove 31; a first traverse groove 32; a second peripheral groove 33.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a sealing plate having a valve for releasing the pressure inside a container, a method for manufacturing the sealing plate, and a sealed battery.

  The sealed battery is provided with a safety valve (pressure relief valve or explosion-proof valve) that discharges internal gas when the pressure in the container exceeds a design allowable value. The safety valve may be provided in a battery container, or may be provided in a sealing plate attached to seal the container after an electrode or the like is placed in the container. In general, for ease of processing, a safety valve is often provided integrally with a sealing plate.

  According to the sealing body (sealing plate) described in Patent Document 1 and the manufacturing method thereof, the annular groove along the inner periphery of the rectangular concave portion and the X-shaped slit-scheduled groove along the diagonal line are provided. And it is disclosed that a safety valve is formed integrally with the sealing body by carrying out stamping processing (embossing molding) in two stages by a shallow groove portion and a deep groove portion, respectively.

  According to the secondary battery described in Patent Document 2, the gas discharge valve in which the gas discharge valve (safety valve) is provided integrally with the battery lid includes an outer peripheral groove along the inner periphery of the oval concave portion, A central groove element that connects the centers of the arcs, and a radial groove element that extends from the center of the arc to the outer peripheral groove part. And it has the discontinuous part which connects with a battery cover (sealing board) in the middle of an outer periphery groove part so that two trapezoid area | regions and two triangular area | regions made by these groove | channels may not scatter.

  According to the sealing plate for a sealed battery and the method for manufacturing the same described in Patent Document 3, a valve is provided in an oblong recess formed integrally with the recess of the sealing plate. A first groove having a constant width along the inner periphery of the recess and a second groove having a smaller width on the bottom surface of the first groove are integrally formed on the sealing plate by coining (compression processing). It is disclosed that the procedure of the manufacturing method of this valve is as follows. First, an oval recess is formed in the first step of the first compression process, and a first groove having a constant width is formed by coining along the inner periphery of the recess in the subsequent step. As a result, the bulging portion is formed inside the first groove. Next, in the second compression processing, when the second groove is formed by coining along the contour of the predetermined region surrounding the bulging portion, the predetermined region becomes a stepped portion and the bulging portion further has a depth of the groove. It bulges in the opposite direction. And in order to stabilize the fracture | rupture pressure of a 2nd groove part, the annealing process is performed after compression processing.

Japanese Patent No. 5059033 JP 2011-181214 A Japanese Patent Laid-Open No. 11-273640

  By the way, in the case of a secondary battery that repeatedly charges and discharges among sealed batteries, an internal pressure close to a design allowable pressure may be applied by a gas generated inside during charging or discharging. The application field of secondary batteries is expanding, and the reliability of safety valves (explosion-proof valves) is required. In particular, the durability of the safety valve against repeated loads due to internal pressure, that is, the durability of the safety valve against repeated tensile stress below an allowable pressure is regarded as important. In order to improve the durability of the safety valve against repeated loads, it is only necessary to increase the thickness of the bottom portion of the groove serving as the opening portion of the safety valve formed integrally with the sealing plate.

  However, increasing the thickness of the bottom of the groove means that the safety valve will not operate at the desired pressure. That is, it is difficult to achieve both the improvement of the durability of the safety valve and the stability that ensures the safety valve is opened by the operating pressure. In any of the techniques described in Patent Documents 1-3, no study has been made on repeated durability below the allowable pressure for the safety valve.

  Accordingly, the present invention provides a sealing plate provided with a reliable safety valve that achieves both durability against repeated stress due to internal pressure less than the allowable pressure and stability that can be reliably opened at the operating pressure, and a method for manufacturing the sealing plate, And the sealed battery provided with this sealing board is provided.

  The sealing board of one Embodiment which concerns on this invention is provided with a plate part and a safety valve. The plate portion closes the opening of the container of the sealed battery and forms an outer shell together with the container. The safety valve is formed integrally with a part of the plate portion. The safety valve includes an outer concave portion, an inner concave portion, an outer curved portion, at least two hatch portions, a ligament portion, a first circumferential groove, a first transverse groove, and a second circumferential groove. Including. The outer recessed portion is recessed from the outer surface of the plate portion. The inner recess is recessed from the inner surface of the plate portion at a position coinciding with the outer recess. The outer peripheral curved portion is formed between the outer concave portion and the inner concave portion so as to extend continuously from the plate portion and along the inner circumference of the outer concave portion, and bulges toward the outer concave portion. The hatch portions are formed continuously from the outer peripheral curved portion inside the outer peripheral curved portion, and respectively bulge toward the outer concave portion. The ligament portion connects each of the hatch portions to the outer curved portion. The first circumferential groove is disposed between the outer circumferential curved portion and the hatch portion, and is recessed from the outer recessed portion side. The first transverse groove is disposed between at least two hatch portions, is recessed from the outer recessed portion side, and is continuous with the first circumferential groove. The second circumferential groove is formed in the first circumferential groove except at least the ligament part.

  In this case, in the sealing plate, the outer recessed portion has an inner peripheral edge perpendicular to the outer surface, and the inner recessed portion has an inclined edge that expands outward from a position corresponding to the inner peripheral edge. In the sealing plate, the hatch portion preferably has a thick portion thicker than the outer curved portion on the inner side surrounded by the first circumferential groove and the first transverse groove. The sealing plate may further include a second transverse groove formed in the first transverse groove and continuing to the second circumferential groove.

  In the sealing plate, the first circumferential groove may be formed discontinuously at the ligament portion, and the ligament portion may be connected to the hatch portion with the same plate thickness as the outer curved portion. Alternatively, in the sealing plate, the first circumferential groove is formed discontinuously in the ligament part, the second circumferential groove is formed discontinuously away from the ligament part than the first circumferential groove, and the ligament part is It may be connected to the hatch portion with the same thickness as that of the outer curved portion. Alternatively, in the sealing plate, the first circumferential groove may be formed continuously in the ligament portion, and the ligament portion may have the same plate thickness as the bottom portion of the first circumferential groove and the outer peripheral curved portion connected to the hatch portion. .

  Further, in the sealing plate, the outer concave portion and the inner concave portion are formed in an oval shape, and the first transverse groove includes an oblique groove that is continuous with the first circumferential groove obliquely with respect to the elliptical major axis direction, The first transverse groove may include an elliptical central groove extending in the major axis direction and an oblique groove that obliquely continues from the central groove to the first circumferential groove. Alternatively, in the sealing plate, the outer recessed portion and the inner recessed portion are formed in an elliptical shape including a pair of parallel straight edge portions, the first circumferential groove includes a straight groove along the straight edge portion, and the first transverse groove is The straight groove includes an oblique groove that is obliquely continuous, or a central groove in which the first transverse groove is short and parallel to the straight groove, and an oblique groove that is obliquely continuous from the central groove to the linear groove. May be included. Further, at this time, in the sealing plate, the ligament part is disposed at a position away from the linear groove forming an acute angle with respect to the oblique groove, or the ligament part is separated from the linear groove forming an obtuse angle with respect to the oblique groove. It is good to arrange in the position.

  The sealed battery according to an embodiment of the present invention is a sealed battery in which an outer shell is formed by a container having an opening and a sealing plate that closes the opening, and the sealing plate is any of the above-described ones. It is preferable that this is a sealing plate.

  The manufacturing method of the sealing board of one Embodiment which concerns on this invention is a manufacturing method of the sealing board which forms a safety valve in the plate part of the above-mentioned sealing board, Comprising: A recessed part manufacturing process, a 1st marking process, 2nd Engraving process. In the recess processing step, the outer mold for forming the outer recess and the inner mold formed by matching the inner recess with the outer recess are formed with the plate portion sandwiched in the plate thickness direction. In the first marking step, the first circumferential groove and the first transverse groove are formed in the outer concave portion, and the outer concave portion is sandwiched between the plate portion in the plate thickness direction by the receiving die applied to the inner concave portion. An outer peripheral curved portion and a hatch portion are formed so as to bulge toward the direction. In the second marking step, the second circumferential groove is formed by being sandwiched between a second marking formed in the first circumferential groove except at least the ligament part and the receiving die.

  At this time, even in the recess processing step, a thick portion having a plate thickness larger than that of the outer peripheral curved portion may be formed in each of the hatch portions inside the range in which the outer mold is surrounded by the first circumferential groove and the first transverse groove. Good. In the recess processing step, the outer mold has an inner peripheral edge perpendicular to the outer surface formed in the outer peripheral recess, and the inner mold has an inclined edge that extends outward from a position corresponding to the inner peripheral edge in the inner recess. Also good.

  According to the sealing plate according to the present invention, a safety valve is integrally formed on a part of the plate portion, and the safety valve has an outer peripheral curved portion and at least two hatch portions disposed inside the outer peripheral curved portion. Both the outer peripheral curved portion and the hatch portion are formed in a shape bulging toward the outer concave portion. A first circumferential groove is formed between the outer curved portion and the hatch portion, and a first transverse groove is formed between the hatch portions. Further, the second circumferential groove is formed leaving at least the ligament part in the first circumferential groove. Therefore, when pressure is applied from the inner surface side, the first circumferential groove and the second circumferential groove between the outer curved portion and the hatch portion are bent by extending the outer curved portion when the pressure is small. As a result, the bottom of the second circumferential groove is subjected to compressive stress. Therefore, even if an internal pressure below the operating pressure at which the hatch is not opened, i.e., below the operating pressure at which the safety valve is not opened, the change in stress acting on the bottom of the second circumferential groove is small, so the safety valve against repeated internal pressure is applied. Durability is improved. In addition, an opening start point is provided at an intersection where the first transverse groove continues with respect to the first circumferential groove. This intersection is a position deviating from the center of the safety valve, and the stress acting on the safety valve due to the internal pressure of the sealed battery container is smaller in the intersection than in the center. Since the operating pressure set for the safety valve is set with respect to the opening start point, the internal pressure at which the hatch portion is actually opened with respect to the set operating pressure is less varied.

  According to the sealed battery according to the present invention, since the above-described safety valve is formed, the internal pressure is equal to or lower than the operating pressure of the safety valve due to the gas generated in the container when charging and discharging are repeated. Even if it fluctuates repeatedly, the safety valve can be prevented from being opened due to fatigue, and the service life of the sealed battery can be extended.

  According to the method for manufacturing a sealing plate according to the present invention, when the safety valve is integrally formed on the sealing plate, the sealing plate is constructed in three stages, that is, a recess processing step, a first marking step, and a second marking step. . Since the amount of deformation processed at one time is reduced, it is possible to reduce the load of heat and stress on the processed part and its periphery, and also reduce the load applied to the mold during processing. In particular, in the second marking, a part of the mold surface is cut out so that the second circumferential groove is processed except for the ligament part, that is, the second circumferential groove is not processed in a range where the ligament part is provided. Therefore, the lubricating oil or the like interposed between the plate portion and the second stamp is easily discharged from the notched portion. As a result, the useful life of the second stamp can be extended.

1 is a perspective view of a sealed battery according to a first embodiment of the present invention. The perspective view which expanded the safety valve of the F2 part in FIG. 2A is a plan view of the safety valve, FIG. 2B is a sectional view of the safety valve along the line F31-F31, and FIG. 3C is a sectional view of the safety valve along the line F32-F32. The figure which shows typically the area | region deform | transformed by each of the recessed part manufacturing process of a safety valve of FIG. 2, a 1st marking process, and a 2nd marking process. The sealing board which performed the recessed part manufacturing process of the safety valve of FIG. 2 is shown, (A) is a top view of the sealing board by which the outer side recessed part was processed, (B) is sectional drawing of the sealing board along F51-F51 line. 5 shows a sealing plate obtained by subjecting the sealing plate of FIG. 5 to a first marking step, wherein (A) is a plan view of the sealing plate in which the first circumferential groove and the first transverse groove are processed, and (B) is an F61 line. (C) is a fragmentary sectional view of the sealing board which passes F62 line and F63 line. The sealing board which gave the 2nd marking process to the sealing board of FIG. 6 is shown, (A) is a top view of the sealing board by which the 2nd circumferential groove and the 2nd transverse groove were processed, (B) is F71 line | wire Partial sectional drawing of the sealing board which passes along, (C) is a partial sectional view of the sealing board which passes along F72 line and F73 line. FIG. 3 is a perspective view of the safety valve in a state where the hatch portion of FIG. 2 is opened. The perspective view of the safety valve provided in the sealing board of 2nd Embodiment which concerns on this invention. The safety valve of FIG. 9 is shown, (A) is a top view of a safety valve, (B) is sectional drawing of the safety valve which follows F101-F101 line, (C) is sectional drawing of the safety valve which follows F102-F102 line. The figure which shows typically the area | region deform | transformed by each of the recessed part manufacturing process of a safety valve of FIG. 9, a 1st marking process, and a 2nd marking process. 9 shows the sealing plate subjected to the recess processing step of the safety valve of FIG. 9, (A) is a plan view of the sealing plate in which the outer recess is processed, (B) is a cross-sectional view of the sealing plate taken along line F121-F121, (C ) Is a cross-sectional view of a sealing plate taken along line F122-F122. The sealing board which gave the 1st marking process to the sealing board of FIG. 12 is shown, (A) is a top view of the sealing board by which the 1st circumferential groove and the 1st crossing groove were processed, (B) is F131 line | wire Partial sectional drawing of the sealing board which passes along, (C) is a partial sectional view of the sealing board which passes along F132 line. The sealing board which gave the 2nd marking process to the sealing board of FIG. 13 is shown, (A) is a top view of the sealing board by which the 2nd circumferential groove and the 2nd crossing groove were processed, (B) is F141 line | wire The fragmentary sectional view of the sealing board which passes along, (C) is the partial sectional view of the sealing board which passes F142 line. The perspective view of the safety valve provided in the sealing board of 3rd Embodiment which concerns on this invention. The figure which shows typically the area | region deform | transformed by each of the recessed part manufacturing process of a safety valve of FIG. 15, a 1st marking process, and a 2nd marking process. 15 shows the sealing plate subjected to the recess processing step and the first marking step of the safety valve in FIG. 15, (A) is a plan view of the sealing plate in which the first circumferential groove and the first transverse groove are processed, (B). FIG. 4 is a partial cross-sectional view of a sealing plate that passes through lines F171 to F173. FIG. 17 shows a sealing plate obtained by subjecting the sealing plate of FIG. 17 to a second marking step, in which (A) is a plan view of the sealing plate in which the second circumferential groove and the second transverse groove are processed, and (B) is a line F181. (C) is a fragmentary sectional view of the sealing board which passes F182 line and F183 line. The perspective view of the safety valve provided in the sealing board of 4th Embodiment which concerns on this invention. The figure which shows typically the area | region deform | transformed by each of the recessed part processing process of a safety valve of FIG. 19, a 1st marking process, and a 2nd marking process. FIG. 19 shows a sealing plate subjected to a recess processing step, a first marking step, and a second marking step of the safety valve in FIG. 19, (A) is a plan view of the sealing plate in which the second circumferential groove is processed; ) Is a partial cross-sectional view of the sealing plate that passes through the F211 line, (C) is a partial cross-sectional view of the sealing plate that passes through the F212 line, and (D) is a partial cross-sectional view of the sealing plate that passes through the F213 line. The perspective view of the safety valve provided in the sealing board of 5th Embodiment which concerns on this invention. 22 shows the sealing plate subjected to the recess processing step and the first marking step of the safety valve of FIG. 22, (A) is a plan view of the sealing plate in which the first circumferential groove and the first transverse groove are processed, (B). Is a partial cross-sectional view of the sealing plate passing through line F231, and (C) is a partial cross-sectional view of the sealing plate passing through lines F232 and F233. 23 shows a sealing plate obtained by subjecting the sealing plate of FIG. 23 to a second marking step, wherein (A) is a plan view of the sealing plate in which the second circumferential groove and the second transverse groove are processed, and (B) is a line F241. (C) is a fragmentary sectional view of the sealing board which passes F242 line and F243 line. The perspective view of the safety valve provided in the sealing board of 6th Embodiment which concerns on this invention. The figure which shows typically the area | region deform | transformed by each of the recessed part manufacturing process of a safety valve of FIG. 25, a 1st marking process, and a 2nd marking process. 25 shows a sealing plate subjected to a recess processing step, a first marking step, and a second marking step of the safety valve of FIG. 25, (A) is a sealing plate in which a second circumferential groove and a second transverse groove are processed. (B) is a partial sectional view of the sealing plate passing through the F271 line, (C) is a partial sectional view of the sealing plate passing through the F272 line, and (D) is a portion of the sealing plate passing through the F273 line. Sectional view. The perspective view of the safety valve provided in the sealing board of 7th Embodiment which concerns on this invention. The figure which shows typically the area | region deform | transformed by each of the recessed part manufacturing process of a safety valve of FIG. 28, a 1st marking process, and a 2nd marking process. 28 shows the sealing plate subjected to the recess processing step of the safety valve of FIG. 28, (A) is a plan view of the sealing plate in which the outer recess and the thick portion are processed, and (B) is a cross section of the sealing plate along the line F301-F301. FIG. 4C is a cross-sectional view of the sealing plate taken along line F302-F302. 30 shows a sealing plate obtained by subjecting the sealing plate of FIG. 30 to a first marking step, (A) is a plan view of the sealing plate in which the first circumferential groove and the first transverse groove are processed, and (B) is an F311 line. (C) is a partial cross-sectional view of the sealing plate passing through line F312; (D) is a partial cross-sectional view of the sealing plate passing through line F313. 31 shows a sealing plate obtained by subjecting the sealing plate of FIG. 31 to a second marking step, wherein (A) is a plan view of the sealing plate in which the second circumferential groove and the second transverse groove are processed, and (B) is a line F321. (C) is a fragmentary sectional view of the sealing board which passes F322 line, (D) is a fragmentary sectional view of the sealing board which passes F323 line. The figure which shows the pattern of the groove | channel of the safety valve of other embodiment.

  A sealed battery 1 according to a first embodiment of the present invention will be described with reference to FIGS. A sealed battery 1 shown in FIG. 1 has an outer shell sealed by a container 2 having an opening 2A and a sealing plate 3 that closes the opening 2A. The container 2 stores the core together with the electrolytic solution. The core is manufactured by interposing a separator and laminating or winding a positive electrode and a negative electrode. The positive and negative terminals 41 and 42 penetrate the sealing plate 3 from the inside to the outside of the container 2, and are fixed to the sealing plate 3 via an insulating member 43. The container 2 of the sealed battery 1 of the present embodiment is formed in a square shape that is flat in a direction crossing the direction in which the terminals 41 and 42 are arranged.

  The sealing plate 3 includes a plate portion 3A and a safety valve 3B. The plate portion 3 </ b> A closes the opening 2 </ b> A of the container 2 of the sealed battery 1 and forms an outer shell together with the container 2. The safety valve 3B is integrally formed on a part of the plate portion 3A at a position between the terminals 41 and 42. 3 A of plate parts have the level | step difference which fits with the opening part 2A of the container 2 in the outer peripheral part 3C. The groove formed by attaching the outer peripheral part 3C of the plate part 3A and the edge of the opening part 2A of the container 2 is sealed and welded by laser welding or the like. In addition, if it is a sealing means applied to the sealed battery 1, the sealing means of the container 2 and the sealing board 3 may be joined by methods other than welding.

  As shown in FIG. 2, the safety valve 3 </ b> B includes an outer recessed portion 301, an inner recessed portion 302, an outer curved portion 303, a hatch portion 304, a ligament portion 305, a first circumferential groove 31, and a first transverse groove 32. And at least a second circumferential groove 33. In the case of this embodiment, a second transverse groove 34 is further included. As shown in FIGS. 2 and 3B and 3C, the outer recess 301 is recessed from the outer surface of the sealing plate 3 serving as the outer shell, that is, the plate portion 3A. The inner recess 302 coincides with the outer recess 301 and is recessed from the inner surface of the sealing plate 3 serving as the outer shell, that is, the plate portion 3A. The outer recessed portion 301 has an inner peripheral edge 306 perpendicular to the outer surface of the plate portion 3 </ b> A, and the inner recessed portion 302 has an inclined edge 307 that expands from the position corresponding to the inner peripheral edge 306 toward the inside of the container 2. ing. In the case of this embodiment, the outer recessed part 301 and the inner recessed part 302 are formed in an elliptical shape, more specifically, an elliptical shape including a pair of parallel straight edge portions.

  As shown in FIGS. 3B and 3C, the outer peripheral curved portion 303 is continuous with the plate portion 3 </ b> A between the outer concave portion 301 and the inner concave portion 302 and along the inner peripheral edge 306 of the outer concave portion 301. It is formed with a constant width and bulges toward the outer recess 301. At this time, the outer peripheral curved portion 303 is formed so as not to protrude from the outer surface of the plate portion 3A. Further, the inner surface side of the outer peripheral curved portion 303 is formed so as to be smoothly continuous with the inclined edge 307 of the inner concave portion 302 by the outer peripheral curved portion 303 bulging outward. Thereby, the stress which acts on the continuous part of the outer periphery curved part 303 and the plate part 3A by the deformation | transformation at the time of a process and the internal pressure of the sealed battery 1 is relieved.

  As shown in FIG. 2 and FIG. 3A in this embodiment, at least two hatch portions 304 are formed in the direction along the parallel straight edges of the outer recess 301 and the inner recess 302 formed in an elliptical shape. Two are arranged. As shown in FIGS. 3B and 3C, the hatch portion 304 is formed continuously from the outer peripheral curved portion 303 inside the outer peripheral curved portion 303 and bulges toward the outer concave portion 301.

  The ligament portion 305 connects each of the hatch portions 304 to the outer curved portion 303 as shown in FIGS. 2, 3 </ b> A, and 3 </ b> C. This ligament part 305 is provided in order to prevent the hatched part 304 that is opened when the internal pressure of the container 2 of the sealed battery 1 exceeds the operating pressure set in the safety valve 3B from being scattered as foreign matter. Therefore, the ligament part 305 is preferably provided at a position far from the position set as the starting point when the hatch part 304 is opened.

  As shown in FIGS. 2 and 3, the first circumferential groove 31 is disposed between the outer circumferential curved portion 303 and the hatched portion 304 and is recessed from the outer recessed portion 301 side. The first circumferential groove 31 includes a linear groove 311 and an arc groove 312. The straight groove 311 is a portion along a straight edge provided in a pair of the outer recesses 301. The arc groove 312 extends so as to be connected by an arc from the end of one linear groove 311 to the end of the other linear groove 311 of two linear grooves 311 extending in parallel. The first transverse groove 32 is disposed so as to cross between the two hatched portions 304 and is recessed from the outer recessed portion 301 side to the same depth as the first circumferential groove 31. 31 linear grooves 311 are connected from one to the other.

  In the case of this embodiment, as shown in FIGS. 2 and 3, the first circumferential groove 31 is formed discontinuously in the ligament portion 305. In other words, the ligament part 305 is disposed across the first circumferential groove 31. Specifically, the ligament part 305 is disposed between the end of the linear groove 311 and the arc groove 312. Therefore, the ligament part 305 is connected to the hatch part 304 with the same plate thickness as the outer peripheral curved part 303.

  The first transverse groove 32 includes an oblique groove 321 that is obliquely continuous with respect to the major axis direction of the outer recess 301 formed in an elliptical shape, that is, with respect to the linear groove 311. In the present embodiment, the intersecting angle between the straight groove 311 and the oblique groove 321 is between 30 ° and 60 °, preferably about 45 °.

  As shown in FIGS. 2 and 3, the second circumferential groove 33 is formed in the first circumferential groove 31 except at least the ligament portion 305. In the present embodiment, the second circumferential groove 33 is provided over the entire area of the first circumferential groove 31. The second transverse groove 34 is formed in the first transverse groove 32 at the same depth as the second circumferential groove 33, and is continuous with the second circumferential groove 33. That is, the second circumferential groove 33 and the second transverse groove are formed over the same range as the first circumferential groove 31 and the first transverse groove 32, and therefore the second circumferential groove 33 is a straight groove. 331 and the arc groove 332, and the second transverse groove 34 includes an oblique groove 341.

  As already described, the ligament part 305 is preferably provided at a position away from the starting point when the hatch part 304 is opened. In the case of the present embodiment, as described above, the first circumferential groove 31, the first transverse groove 32, the second circumferential groove 33, and the second transverse groove 34 are formed. The portion where one transverse groove 32 intersects, that is, the portion where the second circumferential groove 33 and the second transverse groove 34 intersect, tends to be the opening start point X. Therefore, the ligament part 305 is located far from the opening starting point X with respect to each hatch part 304, that is, between the end of the linear groove 311 on the side that forms an acute angle with the oblique groove 321 and the arc groove 312. A ligament part 305 is provided.

  A manufacturing method of the sealing plate 3 in which the safety valve 3B configured as described above is formed integrally with the plate portion 3A will be described with reference to FIGS. According to the manufacturing method of the sealing plate 3 of one embodiment according to the present invention, it includes a recess processing step, a first marking step, and a second marking step, and is processed in three stages. A safety valve 3B is formed integrally with a part of the plate portion 3A.

  FIG. 4 schematically shows a range processed in each step. In order from the bottom in FIG. 4, a region P1 embossed in the recess processing step, a region P2 embossed by the first stamping in the first stamping step, and a second stamping in the second stamping step. An area P3 to be pushed is shown. Both are exaggerated for easy understanding.

  FIG. 5 shows a state in which the recess processing step has been performed on the material of the sealing plate 3, FIG. 6 shows a state in which the first marking step has been performed on the sealing plate 3 in FIG. 5, and FIG. The state which performed the 2nd marking process with respect to this sealing plate is shown.

  In the recess processing step, as shown in FIG. 5, the outer recess 301 and the inner recess 302 are formed on the plate portion 3A by pressing the plate portion 3A of the sealing plate 3 between the outer mold and the inner mold in the thickness direction. Mold simultaneously to the part. At this time, the plate portion 3A is a primary material before the safety valve 3B is processed. The outer mold is a convex mold that forms the outer concave portion 301 from the outer surface of the outer shell in the plate thickness direction. The inner mold is a convex mold formed by aligning the inner recess 302 with the outer recess 301 from the inner surface of the outer shell in the plate thickness direction. FIG. 5A shows a plan view of the processed range viewed from the outer concave portion 301 side, and FIG. 5B shows a cross-sectional view of the range in which the outer concave portion 301 and the inner concave portion 302 are formed.

  In the first marking step, the peripheral curved portion 303, the two hatched portions 304, and the plate portion 3A that has undergone the recess processing step are pressed between the first marking and the receiving die in the plate thickness direction, The ligament part 305 is formed. The first marking has a convex mold for forming the first circumferential groove 31 and the first transverse groove 32, and is pressed against the outer concave portion 301. The receiving mold has a convex shape that fits into the inner recess 302 and is applied to the inner recess 302. FIG. 6A shows a plan view in which the first circumferential groove 31 and the first transverse groove 32 are processed in the outer recessed portion 301 by passing through the first marking step, and the F61 line in FIG. 6A. 6B is a cross section taken along line F62 (cross section of the first circumferential groove 31) in FIG. 6A and a cross section taken along line F63 (first cross section). A cross section of the transverse groove 32 is shown in FIG.

  Further, through the first marking step, the outer peripheral curved portion 303 is formed outside the first circumferential groove 31, and the two hatched portions 304 are surrounded by the first circumferential groove 31 and the first transverse groove 32. Formed inside. The outer peripheral curved portion 303 and the hatched portion 304 bulge toward the outer concave portion 301 by pressing the first stamp on the flat receiving mold. Moreover, the discontinuous part which does not process the 1st circumferential groove 31 is left as much as possible to the ligament part 305.

  In the second marking step, the plate portion 3A that has undergone the first marking step is pressed between the second marking and the receiving die in the plate thickness direction, so that the second circumferential portion 31 has a second stamping process. The circumferential groove 33 is formed excluding at least the ligament portion 305. In the case of the present embodiment, the safety valve 3B also has the second transverse groove 34. Therefore, the second marking is the second circumferential groove 33 and the second transverse groove 34 in the first circumferential groove 31. And a convex shape formed in each of the first transverse grooves 32.

  The second circumferential groove 33 has a discontinuous portion that matches the discontinuous portion of the first circumferential groove 31. The ligament portion 305 is a portion that connects each of the discontinuous portions, that is, the hatch portions 304 to the outer circumferential curved portion 303. The second circumferential groove and the second transverse groove are respectively processed in the first circumferential groove 31 and the first transverse groove 32 through the second marking step, and a plan view is shown in FIG. FIG. 7B shows a cross section taken along line F71 in FIG. 7A (cross section of the ligament portion 305), and a cross section taken along line F72 in FIG. 7A (first circumferential groove 31 and second cross section). FIG. 7C shows a cross section of the circumferential groove 33 and a cross section along the F73 line (cross sections of the first transverse groove 32 and the second transverse groove 34), respectively.

  In the sealing plate 3 made by the above manufacturing method, the safety valve 3B shown in FIGS. 2 and 3 is formed integrally with the plate portion 3A and incorporated in the sealed battery 1. When internal pressure is applied to the container 2 of the sealed battery 1, the safety valve 3 </ b> B is pressed toward the outside of the container 2. At this time, the outer peripheral curved portion 303 and the hatched portion 304 bulge toward the outer concave portion 301. Therefore, while the inner pressure is relatively small, the outer peripheral curved portion 303 is displaced so as to be pushed outward. The inner periphery of the portion 303, that is, the portion provided with the first circumferential groove 31 and the second circumferential groove 33 is displaced so as to be narrowed. Therefore, compressive stress acts on the bottoms of the first circumferential groove 31 and the second circumferential groove 33. When the internal pressure approaches the pressure set in advance as the operating pressure (opening pressure) of the safety valve 3 </ b> B, tensile stress acts on the bottoms of the first circumferential groove 31 and the second circumferential groove 33.

  Further, since the first transverse groove 32 and the second transverse groove 34 are oblique grooves 321 and 341 inclined with respect to the first circumferential groove 31 and the second circumferential groove 33, the hatch portion 304 is The edge 304B facing the straight grooves 311 and 331 forming an acute angle with the oblique grooves 321 and 341 is longer than the edge 304A facing the straight grooves 311 and 331 forming an obtuse angle with the oblique grooves 321 and 341. Further, a ligament portion 305 is provided between the end portions of the linear grooves 311 and 331 that form an acute angle with the oblique grooves 321 and 341 and the arc grooves 312 and 332. Therefore, in the hatch portion 304, the long edge 304 </ b> B along the straight grooves 311 and 331 has a stronger coupling force to the outer peripheral curved portion 303. As a result, shear stress in the direction along the grooves acts on the bottoms of the first transverse grooves 32 and the second transverse grooves 34 that are the oblique grooves 321 and 341.

  When the internal pressure becomes higher than the operating pressure of the safety valve 3B, the corner where the oblique grooves 321 and 341 and the straight grooves 311 and 331 form an obtuse angle becomes the opening start point X. The safety valve 3B is opened along the bottoms of the circumferential groove 33 and the second transverse groove 34, and the gas that generated the internal pressure is released. The ligament part 305 is arranged at a position far from the opening start point X of the safety valve 3B along the groove. Specifically, the ligament part 305 and the opening start point X are arranged at positions that are substantially symmetrical with respect to the center of the hatch part 304. When the safety valve 3B is opened, the hatched portion 304 rotates to twist the ligament portion 305 to the outside of the container 2 with the ligament portion 305 as a fulcrum as shown in FIG. The energy that opens the hatch portion 304 is absorbed as energy that deforms the ligament portion 305.

  As described above, the safety valve 3B provided on the sealing plate 3 of the sealed battery 1 according to the present invention is a ligament even when the safety valve 3B is opened by generating a pressure exceeding the set operating pressure inside the container 2. Since the portion 305 is provided, the hatch portion 304 is not scattered. Further, the outer peripheral curved portion 303 and the hatched portion 304 bulge outward, but are accommodated inside the outer concave portion 301. That is, the safety valve 3B is formed so as not to protrude from the outer surface of the sealing plate. Therefore, even when the sealing plate 3 is stacked in the manufacturing process of the sealed battery 1, it is possible to prevent the safety valve 3B from being damaged.

  The tensile stress resulting from the internal pressure that opens the safety valve 3B is concentrated in the central portion of the safety valve 3B. When the safety valve 3B is elliptical, if there is a groove along the major axis direction, stress tends to concentrate on the groove. Therefore, when the safety valve 3B has parallel straight portions, it is difficult to determine which side or which position of the straight portion is the opening start point X, and the operation performance of the safety valve 3B becomes unstable. Since the safety valve 3B of the sealing plate 3 according to the present invention is provided with the first transverse groove 32 and the second transverse groove 34, the opening starting point X is the first circumferential groove 31 and the second circumferential groove 33. It is specified at the intersection (groove connection portion) between the first transverse groove 32 and the second transverse groove 34. That is, the operation performance of the safety valve 3B is stabilized.

  In particular, the first transverse groove 32 and the second transverse groove 34 are oblique grooves 321 and 341 that are obliquely connected to the straight grooves 311 and 331 of the first circumferential groove 31 and the second circumferential groove 33. It is. Therefore, the tensile stress in the direction intersecting the groove acting on the bottom of the second transverse groove 34 is the tensile force acting on the bottom when the second transverse groove 34 is arranged parallel to the straight grooves 311 and 331. Instead, the shear stress acts on the bottom of the second transverse groove 34 in the direction along the groove. When the sealed battery 1 is a secondary battery that is repeatedly charged and discharged, it is assumed that an internal pressure lower than the operating pressure for opening the safety valve 3B acts repeatedly. Since the stress that repeatedly acts on the bottom of the second transverse groove 34 by the internal pressure is a shear stress along the second transverse groove 34, durability until fatigue failure due to the repeated stress is improved. That is, the operating performance of the safety valve 3B with respect to the operating pressure is stabilized, and the durability of the safety valve 3B at the operating pressure or lower is also improved.

  Further, according to the manufacturing method of the sealing plate 3, since the outer recess 301 and the inner recess 302 are formed by pressing in the recess processing step, the strength of the safety valve 3B and the surrounding material is increased, and the safety valve 3B is stabilized. Performance can be obtained. In addition, since the second circumferential groove 33 and the second transverse groove 34 are formed in the first circumferential groove 31 and the first transverse groove 32, the amount of deformation processed at a time can be reduced. It is possible to prevent heat and high stress from being generated locally during processing. That is, according to the manufacturing method of the sealing plate concerning the present invention, variation in the material characteristic of safety valve 3B formed by press work can be controlled, and the operation performance of safety valve 3B is stabilized.

  Below, the sealing board 3 of the 2nd to 7th embodiment which concerns on this invention is demonstrated. In each embodiment, the structure which has the same function as the sealing board 3 of 1st Embodiment attaches | subjects the same code | symbol also in each embodiment, and a detailed description considers the corresponding description and drawing of 1st Embodiment. I will do it. Therefore, in the following description of each embodiment, different points will be mainly described, and other details will be described in the embodiment from the first embodiment to the previous embodiment.

  A sealing plate 3 according to a second embodiment of the present invention will be described with reference to FIGS. 9 to 14. FIG. 9 is a perspective view of a safety valve 3 </ b> B formed integrally with a part of the sealing plate 3. The outer circumferential curved portion 303 and the hatched portion 304 are partitioned by the first circumferential groove 31 and the first transverse groove 32 and bulge toward the outer recessed portion 301 side. A second circumferential groove 33 and a second transverse groove 34 are formed in the first circumferential groove 31 and the first transverse groove 32. The second embodiment is different from the safety valve 3B of the first embodiment in that a thick portion 308 is provided at the center of each hatch portion 304.

  FIG. 10A is a plan view of the safety valve 3B of FIG. 9 as viewed from the outer recessed portion 301 side, and a central portion (F101-F101) in which the first transverse groove 32 and the second transverse groove 34 are arranged obliquely. 10B, and FIG. 10C shows a cross-sectional view through the ligament portion 305 (line F102-F102). As shown in FIG. 10C, the thick portion 308 protrudes toward the outer recessed portion 301 at the center portion of the hatched portion 304 and does not protrude toward the inner recessed portion 302 side. Moreover, even if the hatched portion 304 has the thick portion 308, it is accommodated in the outer recessed portion 301.

  The thick portion 308 is produced in the process of forming the safety valve 3B on the sealing plate 3. FIG. 11 schematically shows ranges to be processed in the recess processing step, the first marking step, and the second marking step, respectively. In order from the bottom in FIG. 11, a region P1 embossed in the recess processing step, a region P2 embossed by the first stamping in the first stamping step, and a second stamping in the second stamping step. An area P3 to be pushed is shown. In the region P4 that is differently hatched in the region P1 that is embossed in the recess processing step, the mold is retracted more than the outer recess 301 in order to form the thick portion 308.

  FIG. 12 shows a portion of the safety valve 3B of the sealing plate 3 subjected to the recess processing step. FIG. 12A is a plan view of a processed portion viewed from the outer recessed portion 301 side, and FIG. 12B passes through a central portion (F121-F121 line) where the outer recessed portion 301 and the inner recessed portion 302 are processed. FIG. 12C is a cross-sectional view through a portion (a line F122-F122) where the thick portion 308 is formed. As can be seen from FIG. 12C, the thick wall portion 308 protrudes toward the outer recess portion 301 side and does not protrude toward the inner recess portion 302 side. Further, as shown in FIG. 12, in the recess processing step, the outer peripheral curved portion 303 and the hatched portion 304 are not partitioned and do not bulge to the outer recess 301 side.

  FIG. 13 shows the portion of the safety valve 3B of the sealing plate 3 that has been subjected to the first marking step after the recess processing step. 13A is a plan view, FIG. 13B is a cross-sectional view of a portion (line F131) passing through the ligament portion 305, and FIG. 13C is a portion of the first circumferential groove 31 crossing the arc groove 312 (F132). It is sectional drawing of a line. Although it is difficult to understand from the drawing, the size of the hatched portion 304 bulging toward the outer recessed portion 301 with respect to the outer peripheral curved portion 303 can be suppressed to be slightly smaller by providing the thick portion 308.

  FIG. 14 shows the completed safety valve 3B of the sealing plate 3 that has been subjected to the second stamping process after the first stamping process. 14A is a plan view of the completed safety valve 3B, FIG. 14B is a cross-sectional view of a portion (line F141) passing through the ligament portion 305, and FIG. 14C is an arc groove 332 of the second circumferential groove 33. It is sectional drawing of the part (F142 line) which crosses. As shown in FIG. 14, the second circumferential groove 33 and the second transverse groove 34 are formed over the entire length of the first circumferential groove 31 and the first transverse groove 32.

  When the sealing plate 3 of the second embodiment configured as described above is assembled to the sealed battery 1 and receives an internal pressure equal to or higher than the operating pressure of the safety valve 3B by the gas generated in the container 2, the first embodiment Similarly to the embodiment shown in FIG. 8, the hatch portion 304 is opened. When a sufficiently low pressure is repeatedly received with respect to the operating pressure of the safety valve 3B, the hatch portion 304 has the thick portion 308, so that the amount of deformation is small, and the safety valve provided on the sealing plate 3 of the first embodiment. The durability against fatigue due to repeated stress is improved compared to 3B.

  A sealing plate 3 according to a third embodiment of the present invention will be described with reference to FIGS. 15 to 18. FIG. 15 is a perspective view of a safety valve 3 </ b> B formed integrally with a part of the sealing plate 3. The outer circumferential curved portion 303 and the hatched portion 304 are partitioned by the first circumferential groove 31 and the first transverse groove 32 and bulge toward the outer recessed portion 301 side. Further, the second circumferential groove 33 and the second transverse groove 34 are formed in the first circumferential groove 31 and the first transverse groove 32. The safety valve 3B of the third embodiment is different from the safety valve 3B of the first embodiment in that the first circumferential groove 31 is formed continuously in the ligament part 305, that is, across the ligament part 305. ing.

  FIG. 16 schematically shows ranges processed in the recess processing step, the first marking step, and the second marking step, respectively. In order from the bottom in FIG. 16, a region P1 embossed in the recess processing step, a region P2 embossed by the first engraving in the first engraving step, and a second engraving in the second engraving step. Each of the areas P3 to be pushed is shown. In the present embodiment, the shape of the first marking used in the first marking step is different. Specifically, the first marking has a convex shape that crosses the ligament portion 305, that is, a convex shape that forms the first circumferential groove 31 over the entire circumference as shown in a region P2 in FIG.

  Since the recess processing step is the same as in the first embodiment, FIG. 5 and the description thereof are taken into consideration. FIG. 17 shows a portion of the safety valve 3B of the sealing plate 3 subjected to the first marking process. 17A is a plan view of the processed portion, FIG. 17B is a portion of the first circumferential groove 31 (line F171) crossing the ligament portion 305, and a portion of the circular groove 312 of the first circumferential groove 31 (F172). Line) and a portion of the first transverse groove 32 (line F173). By performing the first marking step, the outer curved portion 303 and the hatched portion 304 are partitioned and bulge toward the outer concave portion 301 side.

  FIG. 18 shows a portion of the safety valve 3B of the sealing plate 3 that has been subjected to the second marking step. 18A is a plan view of the completed safety valve 3B, FIG. 18B is a cross-sectional view taken through the ligament portion 305 (line F181), and FIG. 18C shows the arc groove 332 of the second circumferential groove 33. It is sectional drawing which is common in the part (F183 line) which crosses the part (F182 line) which crosses, and the 2nd crossing groove | channel 34. As can be seen from FIGS. 16 and 18, the ligament portion 305 is configured by a portion where the second circumferential groove 33 is not formed.

  In the safety valve 3B configured as described above, the ligament part 305 is formed in a portion where the second circumferential groove 33 is not formed. In order to satisfy the function of the ligament part 305, the first circumferential groove 31 is formed. The dimensions are adjusted, for example, by reducing the depth of the groove or by increasing the range in which the second circumferential groove is not provided in order to form the ligament portion 305. The safety valve 3B provided on the sealing plate 3 of the third embodiment is the same as the safety valve 3B provided on the sealing plate 3 of the first embodiment, except that the shape of the ligament part 305 is different. . Therefore, when the sealing plate 3 of the third embodiment is adopted as the sealing plate 3 of the sealed battery 1, when the internal pressure equal to or higher than the operating pressure of the safety valve 3B is received as in the first embodiment, the hatch portion 304 is Opened. In addition, the safety valve 3B of the third embodiment also has the first transverse groove 32 and the second transverse groove 34 while the outer peripheral curved portion 303 and the hatch portion 304 bulge toward the outer recessed portion 301 side. Thus, when a sufficiently low pressure is repeatedly received with respect to the operating pressure of the safety valve 3B, durability against repeated stress is high. Further, as with the safety valve 3B of the sealing plate 3 of the first and second embodiments, since the opening start point X is determined, the operation stability in which the hatch portion 304 is opened by the operating pressure is excellent.

  A sealing plate 3 according to a fourth embodiment of the present invention will be described with reference to FIGS. FIG. 19 is a perspective view of the safety valve 3 </ b> B formed integrally with a part of the sealing plate 3. The outer circumferential curved portion 303 and the hatched portion 304 are partitioned by the first circumferential groove 31 and the first transverse groove 32 and bulge toward the outer recessed portion 301 side. The first circumferential groove 31 is formed except for the ligament portion 305. The second circumferential groove 33 is formed in the entire first circumferential groove 31. The safety valve 3B of the fourth embodiment is different from the first embodiment in that the second transverse groove 34 is not formed.

  FIG. 20 schematically shows ranges to be processed in the recess processing step, the first marking step, and the second marking step, respectively. In order from the bottom in FIG. 20, a region P1 to be embossed in the recess processing step, a region P2 to be embossed by the first marking in the first marking step, and a mold by the second marking in the second marking step. Each of the areas P3 to be pushed is shown. In the present embodiment, the shape of the second marking used in the second marking step is different. Specifically, the second marking has a convex shape not including the second transverse groove 34, that is, the second circumferential groove 33 in a range excluding the ligament portion 305, as shown in the region P3 of FIG. It has a convex shape.

  Since the recess processing step and the first marking step are the same as those in the first embodiment, reference is made to FIGS. 5 and 6 and the description thereof. FIG. 21 shows a portion of the safety valve 3B of the sealing plate 3 that has been subjected to the second marking step. 21A is a plan view of the completed safety valve 3B, FIG. 21B is a cross-sectional view of the portion (line F211) passing through the ligament portion 305, and FIG. 21C is an arc groove 332 of the second circumferential groove 33. FIG. 21D is a cross-sectional view of a portion (line F213) crossing the first transverse groove 32 in which the second transverse groove was not processed.

  The safety valve 3B of the sealing plate 3 of the fourth embodiment configured as described above is resistant to shear stress acting in the direction along the first transverse groove 32 by the amount that the second transverse groove is not provided. And high strength. Therefore, the safety valve 3B of the sealing plate 3 according to the fourth embodiment is based on repetitive stress when a pressure lower than the operating pressure is repeatedly applied while maintaining the operation stability in which the hatch portion 304 is opened with respect to the operating pressure. The durability against fatigue is improved as compared with the first embodiment. Further, it is possible to withstand even a large stress compared with the magnitude of the repeated stress.

  A sealing plate 3 according to a fifth embodiment of the present invention will be described with reference to FIGS. FIG. 22 is a perspective view of a safety valve 3 </ b> B formed integrally with a part of the sealing plate 3. The outer circumferential curved portion 303 and the hatched portion 304 are partitioned by the first circumferential groove 31 and the first transverse groove 32 and bulge toward the outer recessed portion 301 side. The second circumferential groove 33 and the second transverse groove 34 are formed in the first circumferential groove 31 and the first transverse groove 32. The safety valve 3B of the sealing plate 3 of the fifth embodiment is different from the safety valve 3B of the first embodiment in the first transverse groove 32 and the second transverse groove 34.

  As shown in FIG. 22, the first transverse groove 32 includes a central groove 322 that is shorter and parallel to the straight groove 311 of the first circumferential groove 31, and a straight groove 311 of the first circumferential groove 31 from both ends thereof. And an oblique groove 321 extending obliquely. Accordingly, the second transverse groove 34 is also formed in the first transverse groove 32, and thus includes the central groove 342 and the oblique groove 341.

  In the case of the fifth embodiment, similarly to the other embodiments, the safety valve 3B is integrally formed on a part of the sealing plate 3 by the recess processing step, the first marking step, and the second marking step. Since the region P1 embossed in the recess processing step is the same as that in the first embodiment, FIG. 5 and the description thereof are taken into consideration.

  FIG. 23 shows a portion of the safety valve 3B of the sealing plate 3 subjected to the first marking step. 23A is a plan view of the processed portion, FIG. 23B is a cross-sectional view of a portion (line F231) passing through the ligament portion 305, and FIG. 23C is crossed by the arc groove 312 of the first circumferential groove 31. FIG. 4 is a cross-sectional view common to a portion (line F232) and a portion (line F233) crossing the central groove 322 of the first transverse groove 32; Therefore, the first marking used in the first marking step has a convex shape that forms the first transverse groove 32 including the central groove 322 and the oblique groove 321 as shown in FIG. doing.

  FIG. 24 shows a portion of the safety valve 3B of the sealing plate 3 that has been subjected to the second marking step. 24A is a plan view of the completed safety valve 3B, FIG. 24B is a cross-sectional view of a portion (line F241) passing through the ligament portion 305, and FIG. 24C is an arc groove 332 of the second circumferential groove 33. 5 is a cross-sectional view common to a portion (line F242) crossing the center groove 342 and a portion (line F243) crossing the central groove 342 of the second transverse groove 34. As shown in FIG. 24, the second circumferential groove 33 and the second transverse groove 34 are formed over the entire length of the first circumferential groove 31 and the first transverse groove 32 as in the first embodiment. Yes.

  In the fifth embodiment, since the safety valve 3B has the central grooves 322 and 342, the opening start point X is set at the intersection of the central grooves 322 and 342 and the oblique grooves 321 and 341. That is, the operating pressure of the safety valve 3B can be easily set by adjusting the length of the central grooves 322 and 342 and the crossing angle between the central grooves 322 and 342 and the oblique grooves 321 and 341. Rather than adjusting the depth of the groove, changing the length of the central grooves 322 and 342 and the arrangement of the oblique grooves 321 and 341 provides a greater degree of freedom and adjustment.

  A sealing plate 3 according to a sixth embodiment of the present invention will be described with reference to FIGS. FIG. 25 is a perspective view of a safety valve 3 </ b> B formed integrally with a part of the sealing plate 3. The outer circumferential curved portion 303 and the hatched portion 304 are partitioned by the first circumferential groove 31 and the first transverse groove 32 and bulge toward the outer recessed portion 301 side. Moreover, the 1st circumferential groove 31 is formed except the ligament part 305 similarly to 5th Embodiment.

  The safety valve 3B of the sixth embodiment is different from the safety valve 3B of the fifth embodiment in the range in which the second circumferential groove 33 and the second transverse groove 34 are formed. Specifically, the second circumferential groove 33 is formed in a range excluding the ligament portion 305 and its vicinity. That is, the second circumferential groove 33 is formed discontinuously apart from the ligament part 305 than the first circumferential groove 31. Further, the second transverse groove 34 is not formed in the central groove 322 of the first transverse groove 32.

  FIG. 26 schematically shows ranges to be processed in the recess processing step, the first marking step, and the second marking step, respectively. In order from the bottom in FIG. 26, a region P1 to be embossed in the recess processing step, a region P2 to be embossed by the first marking in the first marking step, and a mold by the second marking in the second marking step. Each of the areas P3 to be pushed is shown. That is, the first marking used in the first marking step has a convex shape corresponding to the region P2 in FIG. 26, and the second marking used in the second marking step is the region in FIG. It has a convex shape corresponding to P3.

  Since the recess processing step is the same as in the first embodiment, FIG. 5 and the description thereof are taken into consideration. Further, since the first marking step is the same as that of the fifth embodiment, FIG. 23 and the description thereof are taken into consideration. FIG. 27 shows a portion of the safety valve 3B of the sealing plate 3 that has been subjected to the second marking step. 27A is a plan view of the completed safety valve 3B, FIG. 27B is a cross-sectional view of the portion (line F271) passing through the ligament portion 305, and FIG. 27C is an arc groove 332 of the second circumferential groove 33. FIG. 27D is a cross-sectional view of the portion of the second transverse groove 34 that intersects the central groove 322 of the first transverse groove 32 where the central groove 342 is not formed (line F273). FIG.

  In the safety valve 3B of the sealing plate 3 of the sixth embodiment configured as described above, the central groove 322 is formed at the depth of the first transverse groove 32. That is, the portion of the central groove 322 is shallower and the bottom portion is thicker than that of the fifth embodiment because the central groove 342 of the second transverse groove 34 is not formed. Also, the rigidity of the ligament part 305 is increased in the vicinity of the ligament part 305 as much as the second circumferential groove 33 is not formed. Therefore, the safety valve 3B of the sixth embodiment has higher durability against fatigue due to repeated stress than the safety valve 3B of the fifth embodiment when repeated stress due to an internal pressure lower than the operating pressure of the safety valve 3B is applied. At the same time, it is possible to withstand a large stress compared with the magnitude of the repeated stress.

  The opening starting point X may be set at a position where the straight groove 331 of the second circumferential groove 33 and the oblique groove 341 of the second transverse groove 34 intersect, or the oblique groove of the second transverse groove 34. You may set to the position where 341 and the center groove | channel 322 of the 1st crossing groove | channel 32 cross | intersect. The central groove 342 of the second transverse groove 34 may not be formed at all as shown in FIGS. 26 and 27, or may be provided partially or intermittently. By changing the range in which the central groove 342 of the second transverse groove 34 is formed, the responsiveness to the operating pressure of the safety valve 3B and the size that can be accepted as a repetitive stress due to the internal pressure lower than the operating pressure and its It is possible to adjust the durability against fatigue due to repeated stress.

  A sealing plate 3 according to a seventh embodiment of the present invention will be described with reference to FIGS. FIG. 28 is a perspective view of a safety valve 3 </ b> B formed integrally with a part of the sealing plate 3. The outer circumferential curved portion 303 and the hatched portion 304 are partitioned by the first circumferential groove 31 and the first transverse groove 32 and bulge toward the outer recessed portion 301 side. The first circumferential groove 31 is formed except for the ligament portion 305 as in the first embodiment, and the first transverse groove 32 includes a central groove 322 and an oblique groove 321 as in the fifth embodiment. Contains. The second circumferential groove 33 and the second transverse groove 34 are formed over the entire length of the first circumferential groove 31 and the first transverse groove 32. That is, the second transverse groove 34 also includes the central groove 342 and the oblique groove 341.

  The safety valve 3B according to the seventh embodiment is different from the safety valve 3B according to the fifth embodiment in that a thick portion 308 is provided at the center of each hatch portion 304. The thick part 308 is made in the recess processing step for forming the safety valve 3B on the sealing plate 3. FIG. 29 schematically shows ranges to be processed in the recess processing step, the first marking step, and the second marking step, respectively. In order from the bottom in FIG. 29, the regions P1, P4 embossed in the recess processing step, the region P2 embossed by the first engraving in the first engraving step, and the second engraving in the second engraving step. A region P3 embossed by is shown. The region P4 where the thick portion 308 is formed in the recess processing step is provided with the central groove 322 of the first transverse groove 32 and the central groove 342 of the second transverse groove 34. It is smaller than the region P4 where the thick portion 308 of the embodiment is formed.

  FIG. 30 shows a portion of the safety valve 3B of the sealing plate 3 that has been subjected to the recess processing step. FIG. 30A is a plan view of a processed portion viewed from the outer concave portion 301 side, and FIG. 30B passes through a central portion (F301-F301 line) where the outer concave portion 301 and the inner concave portion 302 are processed. FIG. 30C is a cross-sectional view through a portion (line F302-F302) where the thick portion 308 is formed. Similar to the second embodiment, as shown in FIG. 30C, the thick portion 308 protrudes toward the outer recess 301 and does not protrude toward the inner recess 302.

  FIG. 31 shows a part of the safety valve 3B of the sealing plate 3 subjected to the first marking process. 31A is a plan view, FIG. 31B is a cross-sectional view of a portion (line F311) passing through the ligament portion 305, and FIG. 31C is a portion crossing the arc groove 312 of the first circumferential groove 31 (F312). FIG. 31D is a cross-sectional view of a portion (line F313) crossing the central groove 322 of the first transverse groove 32. FIG. Although it is difficult to understand from the drawing, by providing the thick wall portion 308, the size of the hatch portion 304 bulging toward the outer concave portion 301 with respect to the outer peripheral curved portion 303 can be suppressed to be slightly smaller.

  FIG. 32 shows the completed safety valve 3B of the sealing plate 3 subjected to the second marking step. 32A is a plan view of the completed safety valve 3B, FIG. 32B is a cross-sectional view of a portion (line F321) passing through the ligament portion 305, and FIG. 32C is an arc groove 332 of the second circumferential groove 33. FIG. 32D is a cross-sectional view of a portion crossing the central groove 342 of the second transverse groove 34 (line F323).

  The safety valve 3B of the seventh embodiment configured as described above has the same groove pattern as that of the fifth embodiment, and includes the thick portion 308 in the hatch portion 304 as in the second embodiment. . Since the thick part 308 is provided, when receiving the internal pressure as the safety valve 3 </ b> B of the sealing plate 3, the deformation of the center of the hatch part 304 can be suppressed. As a result, since the stress acting on the central grooves 322 and 342 is reduced, durability against fatigue due to repeated stress is improved. Further, the opening start point X with respect to the operating pressure of the safety valve 3B is set at the intersection of the oblique grooves 321 and 341 and the central grooves 322 and 342.

  Finally, the arrangement of the first circumferential groove 31, the first transverse groove 32, the second circumferential groove 33, and the second transverse groove 34 of the safety valve 3B provided on the sealing plate 3 described above, that is, the outer circumferential curved portion 303. FIG. 33 shows various modifications of the pattern of grooves that divide the hatch portion 304 from each other. In FIG. 33, similar patterns are surrounded by a frame. In FIG. 33, the ligament part 305 is shown so as to cross the first circumferential groove 31, but the first circumferential groove 31 may be formed across the ligament part as in the third embodiment. . Further, the second circumferential groove 33 and the second transverse groove 34 may be arranged over the entire length of the first circumferential groove 31 and the first transverse groove 32, or the third, fourth, or sixth. It may be partially arranged as in the embodiment. Furthermore, the thick portion 308 may be included in the hatch portion 304 as in the second and seventh embodiments.

  FIG. 33A shows an obtuse angle of the first transverse groove 32 and the second transverse groove 34 with respect to the safety valve 3B of the first embodiment, and FIG. 33B shows an acute angle. . FIG. 33C shows a case in which the distance between the linear grooves 311 and 331 of the first circumferential groove 31 and the second circumferential groove 33 is larger than that of the safety valve 3B of the first embodiment. FIG. 33D shows a case where the first circumferential groove 31 and the second circumferential groove 33 are elliptical but do not have a straight line portion.

  FIG. 33E shows a short central groove 322, 342 of the first transverse groove 32 and the second transverse groove 34 with respect to the safety valve 3B of the fifth embodiment, and FIG. ). FIG. 33G illustrates the safety valve 3B according to the first embodiment in which the first transverse groove 32 and the second transverse groove 34 are inclined in opposite directions and the ligament portion 305 is provided on the obtuse angle side. 33 in which the first transverse groove 32 and the second transverse groove 34 are perpendicular to the first circumferential groove 31 and the second circumferential groove 33 and the ligament part 305 is disposed in the vicinity of the intersection. H).

  33 (I) and (J), the first transverse groove 32 and the second transverse groove 34 are arranged so that the central grooves 322 and 342 intersect each other. 33 (K) and (L) are different in arrangement of the ligament part 305 from (G) and (H), and the linear grooves 311 and 331 of the first circumferential groove 31 and the second circumferential groove 33 are different. On the other hand, the ligament part 305 is arranged at the end of the first transverse groove 32 and the oblique grooves 321 and 341 of the second transverse groove 34 forming an obtuse angle.

  The first transverse groove 32 and the second transverse groove 34 bent in an “S” shape with respect to the safety valve 3B of the first embodiment are shown in FIGS. 33 (M) and (N), and are gently curved. This is shown in (Q) and (R) of FIG. At this time, (M) and (Q) are shallowly bent, and (N) and (R) are deeply bent. In (Q) of FIG. 33, the first transverse groove 32 and the second transverse groove 34 are symmetric with respect to the center of the safety valve 3B, whereas they are provided with plane symmetry on the center plane along the straight grooves 311 and 331. Is shown in (S). Further, the safety valve 3B according to the first embodiment has the ligament part 305 disposed so as to cross the arc grooves 312 and 332 (O), and the one having a plurality of hatch parts 304 (P) and (T ) Respectively.

  In the above embodiments and modifications, the sealing plate 3 having the safety valve 3B and the sealed battery 1 including the sealing plate 3 have been described. The structure of the safety valve 3B is the same as that of the sealed battery 1 together with the sealing plate 3. You may provide in the container 2 which comprises an outer shell, and may be provided in the container of another sealed electronic component, for example, an electrolytic capacitor. In addition, configurations and structures that differ between the embodiments can be applied to other embodiments, and effects resulting from the configurations and structures can be obtained in the same manner, and combinations thereof are not limited.

  As mentioned above, several embodiment was described about the sealing plate of this invention, the sealing type battery provided with this sealing plate, and the manufacturing method of a sealing plate. These embodiments are merely examples for ease of understanding of the invention, and therefore are not intended to limit the invention to these embodiments. The present invention can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the spirit of the invention. In addition, the modifications of the above-described embodiments are included in the scope of the invention and also include their equivalent scope with respect to the invention described in the claims.

  DESCRIPTION OF SYMBOLS 1 ... Sealed battery, 2 ... Container, 3 ... Sealing plate, 3A ... Plate part, 3B ... Safety valve, 301 ... Outer recessed part, 302 ... Inner recessed part, 303 ... Outer curved part, 304 ... Hatch part, 305 ... Ligament part, 308... Thick part 31. First circumferential groove 311. Linear groove 312. Circular groove 32. First transverse groove 321. Diagonal groove 322 Central groove 33 33 second circumferential groove 331: straight groove, 332: arc groove, 34: second transverse groove, 341: oblique groove, 342: central groove.

The sealing board of one Embodiment which concerns on this invention is provided with a plate part and a safety valve. The plate portion closes the opening of the container of the sealed battery and forms an outer shell together with the container. The safety valve is formed integrally with a part of the plate portion. The safety valve includes an outer concave portion, an inner concave portion, an outer peripheral curved portion, two hatched portions, a ligament portion, a first circumferential groove, a first transverse groove, and a second circumferential groove. . The outer recessed portion is recessed from the outer surface of the plate portion. The inner recess is recessed from the inner surface of the plate portion at a position coinciding with the outer recess. The outer peripheral curved portion is formed between the outer concave portion and the inner concave portion so as to extend continuously from the plate portion and along the inner circumference of the outer concave portion, and bulges toward the outer concave portion. The hatch portions are formed continuously from the outer peripheral curved portion inside the outer peripheral curved portion, and respectively bulge toward the outer concave portion. The ligament portion connects each of the hatch portions to the outer curved portion. The first circumferential groove is disposed between the outer circumferential curved portion and the hatch portion, and is recessed from the outer recessed portion side. First transverse groove is arranged between the two hatch, recessed from the outer recess side, continuous to the first circumferential groove. The second circumferential groove is formed in the first circumferential groove except at least the ligament part.

According to the sealing plate according to the present invention, the safety valve is integrally formed on a part of the plate portion, the safety valve, and a two hatch that will be placed on the inner and outer peripheral curved portion. Both the outer peripheral curved portion and the hatch portion are formed in a shape bulging toward the outer concave portion. A first circumferential groove is formed between the outer curved portion and the hatch portion, and a first transverse groove is formed between the hatch portions. Further, the second circumferential groove is formed leaving at least the ligament part in the first circumferential groove. Therefore, when pressure is applied from the inner surface side, the first circumferential groove and the second circumferential groove between the outer curved portion and the hatch portion are bent by extending the outer curved portion when the pressure is small. As a result, the bottom of the second circumferential groove is subjected to compressive stress. Therefore, even if an internal pressure below the operating pressure at which the hatch is not opened, i.e., below the operating pressure at which the safety valve is not opened, the change in the stress acting on the bottom of the second circumferential groove is small, so Durability is improved. In addition, an opening start point is provided at an intersection where the first transverse groove continues with respect to the first circumferential groove. This intersection is a position deviating from the center of the safety valve, and the stress acting on the safety valve due to the internal pressure of the sealed battery container is smaller in the intersection than in the center. Since the operating pressure set for the safety valve is set with respect to the opening start point, the internal pressure at which the hatch portion is actually opened with respect to the set operating pressure is less varied.

Claims (17)

A plate portion that closes an opening of the container of the sealed battery and forms an outer shell together with the container;
A safety valve formed integrally with a part of the plate portion,
The safety valve is
An outer recess recessed from the outer surface of the plate portion;
An inner recess recessed from the inner surface of the plate portion in alignment with the outer recess;
An outer peripheral curved portion that is formed between the outer concave portion and the inner concave portion in a continuous manner along the inner periphery of the outer concave portion and bulges toward the outer concave portion.
At least two hatch portions formed continuously from the outer peripheral curved portion inside the outer peripheral curved portion and bulging toward the outer concave portion; and
A ligament part that connects each of the hatch parts to the outer curved part,
A first circumferential groove recessed from the outer recessed portion between the outer circumferential curved portion and the hatch portion;
A first transverse groove that is recessed from the outer recessed portion side between at least two of the hatch portions and continues to the first circumferential groove;
A second circumferential groove formed in the first circumferential groove except at least the ligament part;
The sealing board characterized by including. The outer recess has an inner periphery perpendicular to the outer surface;
The sealing plate according to claim 1, wherein the inner concave portion has an inclined edge that expands from a position corresponding to the inner peripheral edge. The sealing plate according to claim 1, further comprising a second transverse groove formed in the first transverse groove and continuing to the second circumferential groove. The first circumferential groove is formed discontinuously in the ligament part,
The sealing plate according to any one of claims 1 to 3, wherein the ligament part is connected to the hatch part with the same plate thickness as the outer peripheral curved part. The first circumferential groove is formed discontinuously in the ligament part,
The second circumferential groove is formed discontinuously apart from the ligament part than the first circumferential groove,
The sealing plate according to any one of claims 1 to 3, wherein the ligament part is connected to the hatch part with the same plate thickness as the outer peripheral curved part. The first circumferential groove is continuously formed in the ligament part,
The said ligament part connects the said outer periphery curved part to the said hatch part with the same plate | board thickness as the bottom part of the said 1st circumferential groove, It was described in any one of Claims 1-3 characterized by the above-mentioned. Sealing plate. The outer recess and the inner recess are formed in an oval shape,
The said 1st crossing groove | channel contains the diagonal groove | channel which continues to the said 1st circumferential groove diagonally with respect to the elliptical major axis direction, The any one of Claim 1-6 characterized by the above-mentioned. The sealing plate described in 1. The outer recess and the inner recess are formed in an oval shape,
The first transverse groove includes a central groove extending in the major axis direction of the elliptical shape, and an oblique groove continuously extending obliquely from the central groove to the first circumferential groove. The sealing board described in any one of Claims 1-6. The outer recess and the inner recess are formed in an oval shape including a pair of parallel straight edges,
The first circumferential groove includes a straight groove along the straight edge,
The sealing plate according to any one of claims 1 to 6, wherein the first transverse groove includes an oblique groove that is obliquely continuous with the linear groove. The outer recess and the inner recess are formed in an oval shape including a pair of parallel straight edges,
The first circumferential groove includes a straight groove along the straight edge,
The first transverse groove includes a central groove that is short and parallel to the straight groove, and an oblique groove that extends obliquely from the central groove to the straight groove. The sealing board described in any one of Claim 6. 11. The sealing plate according to claim 9, wherein the ligament portion is disposed at a position away from the linear groove that forms an acute angle with respect to the oblique groove. The said ligament part is arrange | positioned in the position away from the said linear groove which makes an obtuse angle with respect to the said oblique groove, The sealing board described in any one of Claim 9 or Claim 10 characterized by the above-mentioned. The said hatch part has a thick part thicker than the said outer periphery curved part inside the said 1st surrounding groove and the said 1st crossing groove, It is characterized by the above-mentioned. The sealing board described in any one of these. A sealed battery that forms an outer shell with a container having an opening and a sealing plate that closes the opening,
14. The sealed battery according to claim 1, wherein the sealing plate is the sealing plate according to any one of claims 1 to 13. It is a manufacturing method of the sealing board which forms the safety valve in the plate part of the sealing board described in any 1 paragraph of Claims 1-13,
A recess processing step in which the outer mold that forms the outer recess and the inner mold that forms the inner recess so as to match the outer recess are formed by sandwiching the plate portion in the plate thickness direction;
The outer recessed portion sandwiching the plate portion in the plate thickness direction by a first stamp that forms the first circumferential groove and the first transverse groove in the outer recessed portion and a receiving mold applied to the inner recessed portion. A first marking step for forming the outer peripheral curved portion and the hatch portion so as to bulge to
A second marking step for forming the second circumferential groove by sandwiching the second circumferential groove between the receiving mold and the second marking formed in the first circumferential groove except at least the ligament part;
The manufacturing method of the sealing board characterized by including. In the recess processing step,
The outer mold is formed with a thick part having a plate thickness larger than that of the outer peripheral curved part in each of the hatch parts inside the range surrounded by the first circumferential groove and the first transverse groove. The method for producing a sealing plate according to claim 15. In the recess processing step,
The outer mold forms an inner peripheral edge perpendicular to the outer surface in the outer recess,
The said inner type | mold forms the inclined edge which spreads outward from the position corresponding to the said inner periphery in the said inner side recessed part, The manufacturing method of the sealing board described in Claim 15 or Claim 16 characterized by the above-mentioned.

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