JP4955865B2 - Sealing plate for sealed battery and method for manufacturing the same - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a sealing plate for a sealed battery and a method for manufacturing the same, and particularly relates to a sealing plate having a valve function that communicates with the outside when the pressure in the battery becomes excessive, and a method for manufacturing the sealing plate.
[0002]
[Prior art]
Regarding a sealing plate for a sealed battery and a method for manufacturing the same, Japanese Patent Application Laid-Open No. 11-273640 includes a metal plate that closes an opening of a container of the sealed battery, and surrounds a predetermined region on the surface of the metal plate. There is disclosed a sealing plate configured to form a groove along the contour and to form a bulging portion bulging on the surface side of the metal plate inside the groove. Further, a recess is formed in a region including the groove and the bulging portion on the surface of the metal plate, and the groove and the bulging portion are formed on the bottom surface of the recess.
[0003]
In JP-A-11-273640, a first predetermined region is compressed into a metal plate to form a concave portion on the surface of the metal plate, and the second predetermined region is surrounded by the bottom surface of the concave portion. A manufacturing method of a sealing plate is disclosed in which a groove is formed by compression processing along an outline, and a bulging portion that bulges on the surface side of a metal plate is formed inside the groove.
[0004]
[Problems to be solved by the invention]
According to the sealing plate described in the above-mentioned JP-A-11-273640, when the internal pressure of the sealed battery becomes excessive and the pressure received by the bulging portion exceeds a predetermined pressure, the sealing plate breaks at the groove portion, The bulge is opened and communicates with the external space. Therefore, the breaking pressure can be adjusted by appropriately setting the thickness of the metal plate in the groove portion. Similarly, according to the manufacturing method described in the publication, the breaking pressure in the groove portion of the sealing plate can be adjusted by sequentially setting the thickness of the metal plate in the recess and the groove portion as appropriate. However, when the set rupture pressure is low, the thickness of the metal plate in the groove is thin, so careful handling of the finished product is required, and assembly into a sealed battery is easy. is not.
[0005]
Therefore, the present invention provides a sealing plate that closes the opening of a container of a sealed battery, and even when the set breaking pressure is low, the pressure in the container is set at the set breaking pressure while ensuring rigidity that does not hinder normal handling. It is an object of the present invention to provide a sealing type battery sealing plate that can be reliably broken and communicated to the outside when exceeding the above.
[0006]
Further, the present invention provides a manufacturing method capable of easily manufacturing a sealing plate for a sealed battery that reliably breaks when the pressure in the container exceeds a set breaking pressure while ensuring rigidity that does not hinder normal handling. The issue is to provide.
[0007]
[Means for Solving the Problems]
In order to solve the above problems, a sealing plate of a sealed battery according to the present invention comprises a metal plate that closes an opening of a container of a sealed battery, as defined in claim 1, and is formed on the surface of the metal plate. A recess formed in a predetermined region, and a bottom surface in the recess, extending from the center of the recess to the vicinity of the boundary of the recess, substantially surrounding two adjacent regions, and at least a part of the bottom surface in the recess And a groove formed so as to be flush with each other, and a bulging portion formed so that each of the two regions bulges to the surface side of the metal plate.
[0008]
According to the sealing plate configured as described above, when the internal pressure of the sealed battery becomes excessive and the pressure received by each bulging portion exceeds the set breaking pressure, the sealing plate has the largest distortion at the bottom surface of the recess. Breaks sequentially from the central groove and breaks toward the vicinity of the boundary of the recess. As a result, the above two regions are opened and communicated with the external space, but even when opened in this way, there is a portion that is not broken in each bulging portion, so that the two regions are opened without falling off from the sealing plate. The
[0009]
Furthermore, as described in claim 2, if the groove is formed so as to substantially surround each of the two regions and be flush with the bottom surface in the recess in the vicinity of the boundary of the recess, Even when the region is opened and communicates with the external space, each bulging portion has a portion that is not broken, so that the region is opened without falling off the sealing plate.
[0010]
In addition, as described in claim 3, the groove is a single continuous groove, substantially surrounds each of the two regions, and both ends at the center of the recess are flush with the bottom surface in the recess. For example, as described in claim 4, it may be formed in an S shape in a plan view.
[0012]
Moreover, as a manufacturing method of a sealing plate for a sealed battery according to the present invention, as described in claim 5 , a predetermined region is compressed with respect to the metal plate to form a recess on the surface of the metal plate, Compression processing so that the bottom surface in the recess extends from the central portion of the recess to the vicinity of the boundary of the recess, substantially surrounds two adjacent regions, and at least a part thereof is flush with the bottom surface in the recess. Thus, a groove is formed, and the two regions are bulged to the surface side of the metal plate in accordance with the formation of the groove by compression processing, thereby forming a bulge portion.
[0013]
According to the sealing plate manufacturing method described above, the breaking pressure at the groove portion of the sealing plate is adjusted by appropriately setting the thickness of the concave portion and the metal plate of the groove portion, but the concave portion having the largest distortion. Therefore, it is possible to easily adjust the set breaking pressure to a low pressure at the time of manufacturing the sealing plate without excessively thinning the groove portion.
[0014]
Further, as defined in claim 6 , if the groove is formed so as to substantially surround each of the two regions and to be flush with the bottom surface in the recess in the vicinity of the boundary of the recess, A sealing plate that does not drop off can be formed. Also, the grooves, as described in claim 7, each of the two regions substantially surrounding, be formed to both end at the center portion of the recess is between the bottom surface and the same surface of said recess For example, as described in claim 8 , it may be formed in an S shape in a plan view.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings. 1 and 2 show a sealed battery including a sealing plate according to an embodiment, in which a sealing plate 2 is fitted into an opening 1a of a metal container 1, and the container 1 and the sealing plate 2 are opened. The entire circumference of the portion 1a is hermetically joined by laser welding. The container 1 of the present embodiment is formed by forming a plate made of an aluminum alloy into a rectangular parallelepiped by deep drawing, and accommodates, for example, components (not shown) of a nonaqueous electrolyte battery therein.
[0017]
The sealing plate 2 of the present embodiment is made of an aluminum alloy and is formed in a substantially rectangular shape so as to match the shape of the opening 1 a of the container 1. As shown in FIG. 2, a substantially rectangular recess 2a is formed in the center of the sealing plate 2, and a hole 2b is formed in the center thereof. The gasket 3 is fitted into the hole 2 b and is crimped by the rivet terminal 4, whereby the hole 2 b is sealed by the gasket 3. Note that both the container 1 and the sealing plate 2 may be formed of other metal materials.
[0018]
On the surface of the sealing plate 2, a concave portion 2 c is formed in a predetermined area having an oval shape in plan view defined on either side of the longitudinal direction with the hole 2 b as the center. A groove 22 is formed on the bottom surface 20 in the recess 2c so as to extend from the center of the recess 2c to the vicinity of the boundary 21 of the recess 2c so as to substantially surround the two regions. And the bulging parts 23 and 24 are formed so that two area | regions in the recessed part 2c may bulge to the surface side of the sealing board 2. FIG. In the present embodiment, in particular, it is formed in one continuous groove 22 and is S-shaped in plan view so that both ends are flush with the bottom surface in the recess 2c at the center of the recess 2c. 1). The grooves 22 and the bulging portions 23 and 24 will be described later in detail.
[0019]
The recesses 2a and 2c and the groove 22 are formed by compressing a base plate made of an aluminum alloy, and the breaking pressure of the sealing plate 2 in the groove 22 is adjusted by the amount of compression at this time. Hereinafter, the recessed part 2c, the groove | channel 22, and the bulging part 23 are demonstrated in detail, explaining the manufacturing process of the sealing board 2. FIG.
[0020]
FIG. 3 shows steps in the method for manufacturing the sealing plate 2 according to the embodiment of the present invention, and arrows indicate the flow of the steps. First, in the outer shape shearing process, a shearing process is performed by a press device (not shown) that includes a so-called press machine and a die and performs a pressing process, and the base plate M is punched from a plate material made of an aluminum alloy. Subsequently, in the compression processing step, the central portion R1 and the predetermined region R2 of the base plate M are compressed by a press device. Specifically, coining (coining) is performed, and as shown in the next drilling process, a substantially rectangular recess 2a and a substantially oval recess 2c are formed in plan view. At this stage, the bottom surface 20 of the recess 2c is formed flat as a thin plate portion as shown in FIGS. And the hole 2b is formed in the recessed part 2a in the process of drilling.
[0021]
Next, in the groove compression process, coining is performed again by the press device, and an S-shaped groove 22 (FIG. 1) is formed on the bottom surface 20 in the recess 2c in plan view. At this time, the bottom surface 20 (flat thin plate portion) in the recess 2c bulges toward the opening of the recess 2c with the formation of the groove 22 by coining. Specifically, the sealing plate 2 (actually, the base plate M in FIG. 3) is compressed as described in JP-A-11-273640. At this time, since the upper side of the bottom surface 20 (opening side of the recess 2c) is not pressed by the upper mold (not shown), the bottom surface 20 (thin plate portion) bulges upward in FIGS. The bulging portions 23 and 24 having a convex portion on the opening side and a concave portion on the pressure receiving side below are formed.
[0022]
Thus, since the pressure receiving side of the bulging portions 23 and 24 is formed in a curved concave portion shape, it has a larger area than the bottom surface 20 (flat thin plate portion) of the concave portion 2c before the groove compression processing step of FIG. Finally, in the outer shape shearing process, a shearing process is performed by a press device, and the sealing plate 2 shown in FIGS.
[0023]
Thus, when the recess 2c is formed and the sealing plate 2 having the groove 22 and the bulging portions 23 and 24 formed on the bottom surface 20 thereof is attached to the container 1, and the hole 2b is sealed by the gasket 3. A predetermined valve function is secured by the recess 2c, the groove 22, and the bulging portions 23 and 24. That is, the bulging portions 23 and 24 formed in the two regions function as pressure receiving portions, and the sealing plate 2 has a minimum thickness at the groove 22 portion. And if the internal pressure of the container 1 rises, distortion will arise in the recessed part 2c of the sealing board 2, but the distortion of the center part of the recessed part 2c will become the largest. Accordingly, when the internal pressure of the container 1 becomes excessive and the pressure received by the bulging portions 23 and 24 exceeds the set breaking pressure, the vessel 22 is sequentially broken from the groove 22 located at the center of the recess 2c, and near the boundary 21 of the recess 2c. Break towards. As a result, the two regions where the bulging portions 23 and 24 are formed are opened and communicated with the external space, the interior of the container 1 communicates with the external space, and the internal pressure is reduced at once.
[0024]
The breaking pressure of the sealing plate 2 can be easily adjusted by appropriately setting the thickness of the bottom surface 20 (thin plate portion) of the recess 2c and appropriately setting the thickness of the sealing plate 2 in the groove 22 portion. it can. In this case, since the groove 22 is sequentially broken from the central portion of the concave portion 2c where the distortion is the largest, the set breaking pressure can be easily adjusted to a low pressure without excessively thinning the groove 22 portion. Moreover, since the groove | channel 22 of this embodiment is formed in S shape as shown in FIG. 8, as shown in the state after a fracture | rupture in FIG. Left on the plate 2.
[0025]
3, the recesses 2a and 2c are formed in the sealing plate 2 by continuous processing by a press device (not shown), and a groove 22 is formed in 20 of the recess 2c. Accordingly, since the bulging portions 23 and 24 are formed, the sealing plate 2 having a valve function can be formed of a single component. Thus, a sealing plate that can function as a safety valve for the sealed battery can be provided at low cost.
[0026]
11 to 14 show another embodiment of the present invention. In this embodiment, grooves 25 and 26 are formed on the bottom surface 20 in the recess 2c of the sealing plate 2, and the bulging portion 27 and 28 is formed. The grooves 25 and 26 are formed so as to substantially surround the two regions and to be flush with the bottom surface in the recess 2c in the vicinity of the boundary 21 of the recess 2c . That is, in the present embodiment, as shown in FIG. 12, the grooves 25 and 26 formed in a C shape in plan view are joined at the central portion, and the boundary 21 between the central portion of the concave portion 2c and the concave portion 2c. It extends in the vicinity (left and right in FIG. 12), and both ends thereof are formed so as to be flush with the bottom surface in the recess 2c near the boundary 21 of the recess 2c .
[0027]
Thus, in this embodiment, the bulging portions 27 and 28 formed in the two regions function as pressure receiving portions, and the distortion of the sealing plate 2 when the internal pressure of the container 1 rises is the center of the recess 2c. It becomes the largest in the overlapping part of the grooves 25 and 26 located in the part. Accordingly, when the internal pressure of the container 1 becomes excessive and the pressure received by the bulging portions 27 and 28 exceeds the set breaking pressure, the overlapping portion of the grooves 25 and 26 sequentially breaks and breaks toward the boundary 21 respectively. As a result, the two regions where the bulging portions 27 and 28 are formed are opened and communicated with the external space, the interior of the container 1 communicates with the external space, and the internal pressure is reduced at once.
[0028]
The breaking pressure of the sealing plate 2 at this time can also be adjusted by appropriately setting the thickness of the sealing plate 2 in the grooves 25 and 26, and the grooves 25 and 26 are formed in the recess 2c where the distortion is the largest. Since the rupture is performed sequentially from the central portion, the set rupture pressure can be easily adjusted to a low pressure without excessively thinning the grooves 25 and 26. Further, as shown in FIG. 14 after the breakage, the bulging portions 27 and 28 are left on the sealing plate 2 without dropping off.
[0029]
In any of the above embodiments, the bulging portion (23 and 24, or 27 and 28) is configured not to drop off . Moreover, although the groove | channel in said embodiment is formed in the shape which combined the S-shaped groove | channel or C-shaped groove | channel in planar view, planar view E shape, planar view H shape, planar view 6 It can also be formed in a shape such as a shape, an eight shape in plan view (including mirror-symmetric characters and numbers). When shown to classified these forms is shown in Figure 15.
[0030]
15, as in the embodiment shown in the embodiment and FIGS. 11 to 14 shown in FIGS. 7 to 10 are those according to the embodiment of the bulging portion does not fall off after fracture of the groove, plan view oval For the concave portion having the shape (elliptical shape), the case where the groove extends from the central portion in the long axis direction and the case where the groove extends in the short axis direction are shown.
[0031]
Thus, in any of the embodiments, the breaking pressure can be appropriately adjusted by appropriately setting the thickness of the sealing plate of the recess and the groove, and the pressure received by the bulging portion exceeds the set breaking pressure. In this case, the rupture is performed sequentially from the groove located at the central portion of the concave portion, and the rupture is smoothly and reliably performed. Therefore, the set rupture pressure can be easily adjusted to a low pressure without excessively thinning the groove portion.
[0032]
【Effect of the invention】
Since this invention is comprised as mentioned above, there exists an effect as described below. That is, in the sealing plate of the sealed battery according to claim 1, the recess extends in a predetermined area on the surface of the metal plate and the bottom surface of the recess extends from the center of the recess to the vicinity of the boundary of the recess. A groove formed so that at least a part thereof is flush with the bottom surface in the recess, and the two regions bulge to the surface side of the metal plate, respectively. Since the formed bulging portion is provided, the set breaking pressure of the sealing plate can be easily adjusted by appropriately setting the thickness of the metal plate of the concave portion and the groove portion, and the pressure in the container When the pressure exceeds the set breaking pressure, it can be surely broken and communicated with the outside. In particular, since the rupture is performed sequentially from the central portion of the concave portion where the strain becomes the largest, the set rupture pressure can be easily adjusted to a low pressure without excessively thinning the groove portion. Therefore, it is possible to ensure a high rigidity that does not hinder normal handling. Moreover, since each bulging part is open | released without dropping from a sealing board, it is not necessary to worry about the member after dropping. Moreover, it is inexpensive because it is composed of only a single part formed of a metal plate.
[0033]
If the groove is formed as described in claim 2, each bulging portion is held near the boundary of the recess and is opened without dropping from the sealing plate. There is no need. Further, if the groove is formed as one continuous groove as described in claim 3 and further formed into an S shape in plan view as described in claim 4, a uniform groove can be easily formed. Therefore, it can be set as the structure which can adjust the preset breaking pressure of a sealing board easily .
[0034]
Moreover, in the manufacturing method of the sealing plate according to claim 5 , a predetermined region is compressed to the metal plate to form a recess in the surface of the metal plate, and the bottom surface of the recess is formed from the center of the recess. The groove extends in the vicinity of the boundary of the recess, substantially surrounds the two adjacent regions, and is compressed to form at least a part of the same surface as the bottom surface in the recess. Along with the formation of the groove, the two regions are bulged to the surface side of the metal plate , respectively, to form the bulged portion, and a sealing plate in which each bulged portion does not fall off only by pressing on a single part. Since it can be manufactured, it can be manufactured at low cost. In particular, the breaking pressure at the groove portion of the sealing plate can be adjusted by sequentially setting the thickness of the recess and the metal portion of the groove portion as appropriate, and easily without excessively thinning the groove portion. Since it can be adjusted to a low set breaking pressure, it is easy to manufacture and assemble, and a sealing plate having a desired set breaking pressure can be mass-produced.
[0035]
If the said groove | channel is formed as described in Claim 6 , the sealing board from which each bulging part does not drop | omit can be manufactured easily. Also, the grooves, as one continuous groove as described in claim 7, further, as set forth in claim 8, by forming the S-shape in plan view, for the manufacture of a sealing plate Since the mold can be formed easily and accurately, a sealing plate having a uniform groove can be easily mass-produced. Therefore, the set breaking pressure of the sealing plate can be easily adjusted .
[Brief description of the drawings]
FIG. 1 is a plan view of a sealed battery including a sealing plate according to an embodiment of the present invention.
FIG. 2 is a cross-sectional view of a sealed battery including a sealing plate according to an embodiment of the present invention, in which battery components are omitted.
FIG. 3 is a process chart showing a sealing plate manufacturing method according to an embodiment of the present invention.
FIG. 4 is a front sectional view showing a state where a recess is formed in the sealing plate in one embodiment of the present invention.
FIG. 5 is a plan view showing a state in which a recess is formed in the sealing plate in one embodiment of the present invention.
FIG. 6 is a side sectional view showing a state where a recess is formed in the sealing plate in one embodiment of the present invention.
FIG. 7 is a front sectional view showing a state in which a recess, a groove, and a bulging portion are formed in the sealing plate in one embodiment of the present invention.
FIG. 8 is a plan view showing a state in which concave portions, grooves, and bulging portions are formed in the sealing plate in the embodiment of the present invention.
FIG. 9 is a side sectional view showing a state in which a recess, a groove, and a bulge are formed in the sealing plate in one embodiment of the present invention.
FIG. 10 is a perspective view showing a state after the groove of the sealing plate is broken in one embodiment of the present invention.
FIG. 11 is a front sectional view showing a state in which a recess and a bulge are formed in a sealing plate in another embodiment of the present invention.
FIG. 12 is a plan view showing a state in which a recess and a bulge are formed in the sealing plate in another embodiment of the present invention.
FIG. 13 is a side sectional view showing a state in which a recess and a bulge are formed in a sealing plate in another embodiment of the present invention.
FIG. 14 is a perspective view showing a state after a groove of a sealing plate is broken in another embodiment of the present invention.
FIG. 15 is an explanatory view showing an example of a groove having a form in which a bulging portion does not fall off after breaking as an embodiment of the present invention.
[Explanation of symbols]
1 container, 2 sealing plate, 2a, 2c recess, 2b hole, 3 gasket, 4 rivet terminal, 20 bottom, 21 boundary, 22, 25, 26 groove, 23, 24, 27, 28 bulge

Claims (8)

It consists of a metal plate that closes the opening of the container of the sealed battery, and extends from the center of the recess to the vicinity of the boundary of the recess, and a recess formed in a predetermined region on the surface of the metal plate. And a groove formed so as to substantially surround two adjacent regions and at least a part thereof is flush with the bottom surface in the recess, and the two regions bulge to the surface side of the metal plate, respectively. A sealing plate for a sealed battery comprising a bulging portion formed as described above. 2. The sealed battery according to claim 1, wherein the groove is formed so as to substantially surround each of the two regions and to be flush with a bottom surface in the recess in the vicinity of the boundary of the recess. Sealing plate. The groove is one continuous groove, and substantially surrounds each of the two regions, and is formed so that both ends are flush with the bottom surface in the recess at the center of the recess. The sealing plate for a sealed battery according to claim 1.  4. The sealing plate for a sealed battery according to claim 3, wherein the groove is formed in an S shape in plan view. A predetermined region is compressed with respect to the metal plate to form a recess in the surface of the metal plate, and two adjacent regions extending from the center of the recess to the vicinity of the boundary of the recess on the bottom surface of the recess And forming a groove by compression processing so that at least a part thereof is flush with the bottom surface in the recess, and the two regions are formed on the metal plate by forming the groove by compression processing, respectively. A method for producing a sealing plate for a sealed battery, wherein the bulging portion is formed by bulging to the surface side. 6. The sealed battery seal according to claim 5 , wherein the groove is formed so as to substantially surround each of the two regions and to be flush with a bottom surface in the recess in the vicinity of the boundary of the recess. A manufacturing method of a board. 6. The sealed battery according to claim 5 , wherein the groove is formed so as to substantially surround each of the two regions and have both ends flush with a bottom surface in the recess at a central portion of the recess. Method for manufacturing the sealing plate. 8. The method for manufacturing a sealing plate for a sealed battery according to claim 7 , wherein the groove is formed in an S shape in plan view.

Images