JP5060642B1 - Battery case lid joining method - Google Patents

Abstract

There is provided a battery case lid joining method that is highly productive, does not require high accuracy in the production of a battery case, and can suppress adverse effects due to heat of welding.
A lid 16 is joined to a battery case main body 12 so that the inner diameter increases in a tapered shape as it goes downward, and the inner diameter of the upper end portion has a tapered portion 5 smaller than the outer diameter of the upper end portion of the battery case main body 12. Using the mold body 2 having the crimping hole 3 formed therein and the crimping mold 1 having the cooling means 6 provided in the mold body, the battery case body 12 on which the lid 16 is placed is inserted into the crimping hole 3 from below to the upper end. Is inserted until it is pressed to the inner peripheral side at the upper end of the taper portion 5, and the upper end portion of the battery case body 12 is pressed to the inner peripheral side by the inner wall of the caulking hole 3, and the outer peripheral portion of the lid 16 is caulked. The contact portion between the inner peripheral portion of the upper end portion of the battery case body 12 and the outer peripheral portion of the lid 16 is joined by laser welding.
[Selection] Figure 4

Description

The present invention relates to a battery case lid joining method mainly used in hybrid vehicles and electric vehicles . More specifically, the battery case lid can be joined in a short time, and high accuracy is required when manufacturing the battery case. The present invention also relates to a battery case lid joining method .

  In recent years, so-called new batteries such as lithium ion batteries, sodium batteries, and nickel metal hydride batteries have been adopted as batteries for use in hybrid vehicles, electric vehicles, and the like. These new batteries include an electrode and an electrolyte solution in a battery case. The battery case is configured by a box-shaped or cylindrical battery case main body having an opening at the top and a lid for closing the upper opening of the battery case main body. .

  The new battery constructed as described above is manufactured by filling the battery case body with battery components such as electrodes and electrolyte, and then joining a lid to the upper part of the battery case body.

  Here, as a method of joining the lid to the battery case main body, a laser welding method is generally employed, and there are an upward welding method and a side surface welding method as the laser welding method.

  This laser welding lid joining method will be described with reference to FIG. 10. FIG. 10 is a diagram for explaining a general lid joining method, in which 31 is a battery case body and 32 is a lid. is there. Reference numeral 33 denotes a positioning jig, and 34 denotes pressing means such as an air cylinder. The positioning jig 33 has walls 3301 orthogonal to each other.

  When the lid 32 is joined to the upper opening of the battery case body 31 according to this conventional method, first, the battery case 31 is filled with battery components, and then the two adjacent surfaces of the battery case body 31 are firstly connected. Each is brought into contact with each of the walls 3301 of the positioning jig 33, and as shown in the drawing, the two surfaces not in contact with the wall 3301 are pressed against the wall 3301 by pressing means such as an air cylinder 34. Thus, the battery case body 31 is positioned.

  Next, the lid 32 is placed on the upper part of the battery case body 31 so as to close the upper opening of the battery case body 31, and then the lid 32 is joined to the battery case body 31 by laser welding.

  Here, the relationship between the battery case body 31 and the lid 32 will be described. FIG. 11 shows a case where an upward welding method is employed. In this case, the inner diameter of the upper end portion of the battery case body 31 is widened. By reducing the thickness, the stepped portion 35 is formed on the inner periphery of the upper end portion of the battery case body 31.

  In addition, the height of the inner circumference of the upper end that reduces the thickness of the battery case body 31 is the same as the thickness of the lid 32, while the lid 32 has a reduced outer diameter. The inner diameter of the upper end inner peripheral portion of the case body 31 is the same.

  Then, the lid 32 is placed on the upper end of the battery case body 31 while closing the upper opening of the battery case body 31 by placing the peripheral edge of the lid on the stepped portion 35, and then on the upper surface portion. The four sides of the contact portion (portion indicated by the arrow) of the outer periphery of the lid 32 and the upper end inner periphery of the battery case body 31 are welded from the upper side by a laser beam, and thereby the lid 32 is joined to the battery case body 31. .

  On the other hand, FIG. 12 shows a case where the side surface welding method is adopted. In such a case, the inside of the upper end of the battery case body 31 is formed on the lower surface of the lid 32 by setting the same outer dimensions as the inner diameter of the battery case body 31. A fitting portion 36 that can be fitted to the periphery is formed.

  Then, the lid is placed on the upper end of the battery case main body 31 while closing the upper opening of the battery case main body 31 by fitting the fitting portion 36 to the inner periphery of the upper end of the battery case main body 31. The four sides of the upper end portion of the battery case body 31 and the contact portion (portion indicated by the arrow) of the lid 32 are welded from the measuring method by a laser beam, thereby joining the lid 32 to the battery case body 31.

JP 2009-9868 A JP 2004-39445 A JP 2001-236929 A Japanese Patent Laid-Open No. 11-86809 JP-A-8-315790 JP-A-8-315789 JP-A-8-315788 JP-A-8-250079 JP-A-8-185835

  However, in the upward welding method, it is pointed out that the outer diameter of the lid 32 must match the inner diameter of the upper end of the battery case body 31, which requires accuracy when manufacturing the battery case body and the lid. Has been.

  That is, for example, as shown in FIG. 13, the outer diameter of the lid 32 is smaller than the inner diameter of the upper end of the battery case body 31, thereby creating a gap 37 between the outer periphery of the lid 32 and the inner periphery of the battery case body 31. In other words, a laser beam enters the gap 37 during laser welding, and the battery case body 31 and the lid 32 are not sufficiently joined together. In the case of the upward welding method, high precision is required when manufacturing the lid of the battery case body. Is done.

  Further, the battery case body 31 of the new battery is generally manufactured by slightly inflating the side surface portion as shown in FIG. 14 in order to facilitate insertion of battery components such as an electrode and an electrolytic solution. Prior to joining, after inserting the battery components, as shown in FIG. 15 (a), there is a step of pressing the bulging portion by the pressing means 41 such as an air cylinder to correct the bulging. Since both end portions of the battery case main body are high in strength, as shown in FIG. 15B, when the portion swelled by the pressing means 41 such as an air cylinder is pressed, the side portions swelled are linear. It may become indented without becoming.

  If the lid 32 is forcibly placed on the upper end of the battery case body 31 in this state, a gap 37 may be generated between the inner periphery of the battery case body 31 and the outer periphery of the lid 32. FIG. 16 is a diagram showing a plane in this state. In this state, if laser welding is performed on the contact portion between the outer periphery of the lid 32 and the inner periphery of the battery case 31, a laser beam enters the gap 37, Thereby, while joining of the battery case main body 31 and the lid | cover 32 becomes inadequate, the situation where the finish of welding will worsen is considered.

  On the other hand, in the case of the side welding method, since the upper end of the battery case main body 31 is in contact with the lower surface of the lid 32, the battery case main body 31 and the lid 32 are rarely required to have high accuracy. In order to irradiate the laser beam from the side, the laser beam irradiating means has to be circulated around the battery case 31, and it takes time to irradiate, thereby reducing productivity compared to the upward welding method. It has been pointed out that there is a problem.

  In addition, when joining the battery case body and the lid by laser welding, there is a possibility that the battery components filled in the battery case may be adversely affected by the heat of the laser beam. No effective measures have been taken to address this issue.

Accordingly, the present invention provides a battery case lid joint that is short in welding time and high in productivity, is not required to have high accuracy in the manufacture of the battery case, and can further suppress adverse effects due to the heat of welding. The challenge is to provide a method .

The battery case lid joining method of the present invention includes:
A bottomed battery case main body having a stepped portion formed at the inner periphery of the upper end and having an opening at the top; and a lid for closing the upper opening of the battery case main body by placing a peripheral edge on the stepped portion; A method of joining the lid of the battery case with the battery case body,
A die body with a crimping hole having a tapered portion with an inner diameter that tapers toward the lower side and the inner diameter of the upper end portion is smaller than the outer diameter of the upper end portion of the battery case body, and Using a crimping mold having a cooling means provided in the mold body,
By placing the peripheral edge of the lid on the stepped portion of the battery case body, placing the lid on the upper part of the battery case body while closing the upper opening of the battery case body with the lid,
The battery case body is inserted into the caulking hole from the lower side of the caulking mold, and the battery case body is inserted until the upper end of the battery case body is pressed to the inner peripheral side by at least the upper end portion of the tapered portion. By going to the inner wall of the caulking hole, press the upper end portion of the battery case body toward the inner periphery side and crimp the inner periphery of the upper end portion of the battery case body and the outer periphery portion of the lid,
In this state, the contact portion between the inner peripheral portion of the upper end portion of the battery case body and the outer peripheral portion of the lid is joined by laser welding.

  In the battery case lid joining method of the present invention, a stepped portion is formed on the inner periphery of the upper end portion and a bottomed battery case main body having an opening at the top, and a peripheral portion is placed on the stepped portion of the battery case main body. The lid in the battery case having a lid that closes the upper opening of the battery case main body is joined to the battery case main body, that is, because the above-described upward welding method is adopted, side welding is performed. Unlike the method, it is possible to shorten the welding time.

  And at this time, in the battery case lid joining method of the present invention, the inner diameter of the upper end portion is smaller than the outer diameter of the upper end portion of the battery case body, while the inner diameter is tapered in the downward direction. The lid body is placed on the stepped portion of the battery case body using a mold body having a crimped hole having a tapered portion and a crimping mold having a cooling means provided in the mold body. After closing the upper opening of the main body case with a lid, the battery case main body is inserted into the caulking hole from the lower side of the caulking mold, and the upper end of the battery case main body is at least the inner peripheral side by the upper end portion of the tapered portion. The battery case body is inserted until it is pressed by the inner edge of the battery case body, thereby pressing the upper end portion of the battery case body toward the inner peripheral side with the inner wall of the caulking hole, and the outer periphery of the upper end portion of the battery case body and the outer periphery of the lid After that, since the contact portion between the inner peripheral portion of the upper end portion of the battery case body and the outer peripheral portion of the lid is joined by laser welding, the outer periphery of the lid and the inner periphery of the battery case main body are Therefore, the battery case main body and the lid can be sufficiently joined and finished with a good appearance without requiring high accuracy in manufacturing the battery case.

  Further, the crimping die according to the present invention has a cooling means, while the lid is joined, the upper end portion of the battery case body is pressed by pressing the upper end portion of the battery case body toward the inner peripheral side with the inner wall of the crimping hole. In order to perform laser welding with the inner peripheral portion of the lid and the outer peripheral portion of the lid being caulked, the cooling means provided in the caulking mold can absorb the heat from the laser beam. It is possible to prevent the battery components filled in the battery from being adversely affected.

It is a figure for demonstrating the crimping die used for the Example of the joining method of the cover of the battery case of this invention. FIG. 2 is an end view taken along line AA in FIG. 1. It is a figure for demonstrating the battery case used for the Example of the joining method of the cover of the battery case of this invention. It is a figure for demonstrating the effect | action of the crimping die used for the Example of the joining method of the battery case cover of this invention. It is a figure for demonstrating the Example of the joining method of the cover of the battery case of this invention. It is a figure for demonstrating the other form of the joining method of the cover of the battery case of this invention. It is a figure for demonstrating the other form of the lid | cover used for the Example of the joining method of the lid | cover of the battery case of this invention. It is a figure for demonstrating the other form of the lid | cover used for the Example of the joining method of the lid | cover of the battery case of this invention. It is a figure for demonstrating the other form of the battery case main body used for the Example of the joining method of the cover of the battery case of this invention. It is a figure for demonstrating the joining method of the cover of the conventional battery case. It is a figure for demonstrating the joining method of the cover of the battery case by the conventional upward welding system. It is a figure for demonstrating the joining method of the cover of the battery case by the conventional side surface welding system. It is a figure for demonstrating the problem of the joining method of the battery case cover by the conventional upward welding system. It is a figure for demonstrating the problem of the joining method of the battery case cover by the conventional upward welding system. It is a figure for demonstrating the problem of the joining method of the battery case cover by the conventional upward welding system. It is a figure for demonstrating the problem of the joining method of the battery case cover by the conventional upward welding system.

  In the battery case lid joining method of the present invention, a stepped portion is formed on the inner periphery of the upper end portion and a bottomed battery case main body having an opening at the top, and a peripheral portion is placed on the stepped portion. The lid of the battery case having a lid that closes the upper opening of the battery case body is joined to the battery case body, and the lid is joined to the battery case body using a caulking die.

  The caulking mold has a mold body in which caulking holes are formed, and the caulking hole has a tapered inner diameter that increases toward the lower side, and the inner diameter of the upper end portion is the same as that of the battery case body. Has a tapered part with a diameter slightly smaller than the outer diameter of the upper end part

  Further, the caulking mold has a cooling means, and this cooling means is, for example, a Peltier element, which is provided in the mold body.

  In the battery case lid joining method of the present invention using this caulking mold, first, the peripheral edge of the lid is placed on the stepped portion of the battery case body, thereby opening the upper opening of the battery case body. The lid is placed on top of the battery case body while closing with the lid.

  Next, the caulking mold is placed in a state in which the caulking mold is placed above the battery case body on which the lid is placed, and the battery case body on which the lid is placed is raised or the caulking mold is lowered. The battery case body is inserted into the caulking hole from the lower side of the caulking mold.

  Then, by inserting the battery case main body until the upper end of the battery case main body is pressed toward the inner peripheral side by at least the upper end portion of the taper portion, the upper end portion of the battery case main body is inserted into the inner wall of the caulking hole. By pressing to the peripheral side, the inner periphery of the upper end portion of the battery case main body and the outer peripheral portion of the lid are caulked and adhered.

  Then, the inner wall of the upper end portion of the battery case body and the outer peripheral portion of the lid are caulked with the inner wall of the caulking hole, while the inner peripheral portion of the upper end portion of the battery case main body is in contact with the outer peripheral portion of the lid. The contact points are joined by laser welding.

  An embodiment of the battery case lid joining method of the present invention (hereinafter simply referred to as “lid joining method”) will be described. The lid joining method of this embodiment is a laser welding joining method, The direction welding method is used.

  That is, FIG. 3 is a diagram showing a battery case that is a target of the lid joining method of the present embodiment, in which 11 is a battery case. And the battery case 11 which joins a lid | cover by the joining method of a lid | cover of a present Example, as shown in FIG. 3, the battery case main body 12 made into the box shape of the bottom which made the upper part the opening 13, and this battery case A lid 16 that closes the upper opening 13 of the main body 12 is provided.

  Further, the upper end portion of the battery case main body 12 is thinned while maintaining the outer diameter thereof, that is, the stepped portion 14 is formed on the inner peripheral side by widening the inner diameter, and the battery case main body 12 is thus formed. An upper portion of the step portion 14 in the inner periphery of the upper end portion of the battery is used as a fitting space 15, and a lid 16 is fitted into the fitting space 15 to close the opening 13 at the upper part of the battery case body 11.

  That is, the height dimension of the fitting space 15 is the same as the thickness dimension of the lid 16, while the lid 16 has an outer diameter that is the inner diameter of the inner peripheral portion of the upper end of the battery case body 12 with a reduced thickness. In other words, the outer diameter of the fitting space is made the same, and the peripheral portion of the lid 16 is placed on the stepped portion 14, so that the lid 16 is fitted into the fitting space 15, and the battery case body 12. The lid 16 is placed on the top of the screen.

  In the lid joining method of this embodiment, the lid 16 of the battery case 11 configured as described above is joined to the battery case body using a caulking die.

  In the present embodiment, the battery case body 12 is manufactured by a deep drawing method. However, it is not always necessary to manufacture the battery case body 12 by a deep drawing method. Good.

  Next, the caulking mold will be described with reference to the drawings. FIGS. 1 and 2 are views for explaining the caulking mold used in the lid joining method of this embodiment, and FIG. 1 is a perspective view. 2 is an end view taken along line AA in FIG. 1, and in the figure, 1 is a crimping die.

  The caulking mold 1 includes a mold body made of a material having a certain level of rigidity such as metal. That is, in the figure, reference numeral 2 denotes a mold body. In this embodiment, the mold body 2 has a hexagonal plane field of view, and a caulking hole 3 for caulking the lid to the battery case body is formed in the central portion. Has been.

  Here, the caulking hole 3 will be described. In FIG. 2, the caulking hole 3 has an upper end portion 4. In the present embodiment, the upper end portion 4 corresponds to the thickness dimension of the lid 16 of the battery case 11. The height is similar to that of the battery case body 11, and the outline dimension is slightly smaller than the outer dimension of the upper end portion of the battery case body 11. That is, the upper end 4 is a hole having a similar outline with a slightly smaller size than the upper end of the battery case 11.

  A tapered portion is continuously formed below the upper end portion 4. That is, in the figure, reference numeral 5 denotes a taper portion, and the taper portion 5 has a taper-shaped diameter that increases toward the lower side, and the contour of the upper end portion and the dimensions of the contour are the contour of the upper end portion 4 and The hole has the same size as the contour, that is, the contour of the upper end portion of the tapered portion 5 and the size of the contour are similar to those of the upper end portion 4 and slightly smaller than the upper end portion of the battery case 11. The hole is shaped.

  Next, in FIG. 1, 6 is a cooling means, and in this embodiment, a Peltier element is used as the cooling means. That is, in the caulking mold 1 in this embodiment, a total of four sets of Peltier elements 6 are respectively attached to the surface portion of the mold body 2, and each of the Peltier elements 6 is used for supplying a current to the Peltier element 6. The lead wire 7 is connected to thereby release the heat transmitted to the mold body 2 by laser welding to the outside.

  That is, as is well known, a Peltier element is a plate-like semiconductor that utilizes the Peltier effect that heat flows from one metal to the other when a current is applied to a joint between two types of metal, and a direct current is applied. And one surface absorbs heat and the other surface generates heat. Therefore, in the caulking mold 1 in this embodiment, the Peltier element is provided in the mold body, and the heat transmitted to the mold body 2 by laser welding is released by the Peltier element 6.

  However, the cooling means provided in the caulking mold 1 in the present invention is not necessarily limited to the Peltier element. For example, a flow path is formed inside the mold body 2 and the flow path is used. The external cooling water may be circulated through the inside of the mold body 2, thereby absorbing heat transferred to the mold body 2 by laser welding by the circulating cooling water. Any means that can cool the mold body 2 may be used.

  Next, the operation of the caulking die 1 in this embodiment configured as described above will be described with reference to FIG. 4. In the figure, the battery case body 12 with the lid 16 fitted in the fitting space 15 is When the caulking die 1 is inserted into the caulking hole 3 of the die body 2 from the lower side of the caulking die 1 and advanced in the taper portion 5, the upper end portion of the taper portion 5 as described above is obtained. Since the outline and the dimensions of the outline are slightly smaller than the external dimensions of the upper end portion of the battery case main body 11, the battery case 11 has the upper end portion of the tapered portion 5 as shown in FIG. The progress is interrupted.

  In this state, when the battery case 11 is forcibly advanced upward, the upper end portion of the battery case body 12 is formed by the inner peripheral portion of the upper end portion of the tapered portion 5 or the inner periphery of the upper end portion 4 of the caulking hole 3. That is, the inner wall of the caulking hole 3 is pressed toward the inner peripheral side.

  Then, as shown in FIG. 4B, the upper end portion of the battery case body 12 is deformed toward the inner periphery side, and the inner periphery of the upper end portion of the battery case body 12 and the outer periphery portion of the lid 16 are caulked. It will be in close contact.

  Therefore, for example, as shown in FIG. 4A, when the lid 16 is fitted in the fitting space 15 of the battery case body 12, the gap between the inner periphery of the battery case body 12 and the outer periphery of the lid 16 is set. Even when the gap 17 is formed in the battery case, the inner periphery of the upper end portion of the battery case body 12 and the outer periphery portion of the lid 16 are caulked to be in close contact with each other by using the caulking die 1 of this embodiment. Therefore, the battery case main body 12 and the lid 16 can be sufficiently joined together with a good-looking finish. Therefore, according to the lid joining method of this embodiment, the battery case main body and the lid 16 can be obtained. High accuracy is not required in the manufacture.

  In addition, after caulking holes 3, the inner periphery of the upper end portion of the battery case body 12 and the outer periphery of the lid 16 are caulked and adhered, and then laser welding is performed in this state, so that the heat of the laser applied to the battery case 11 can be reduced. The caulking die 1 can escape and the heat transferred to the caulking die 1 is released to the outside by the Peltier element 6 as a cooling means provided in the caulking die 1. It is also possible to prevent the battery components filled in the case from being adversely affected.

  Next, an embodiment of the present invention in which a lid is joined to a battery case body using the caulking die 1 of the present embodiment having such an action will be described with reference to FIG. It is a figure which shows a part of the system 21 for joining the lid | cover 16 to the battery case main body 12 with the joining method of this lid | cover, The system 21 in FIG. 5 is equipped with the conveyor 22 which comprises a conveyance line, This conveyor 22, the battery case body 12 is tact-fed.

  Further, a means for fitting the lid 16 into the fitting space 15 of the battery case body 12 being conveyed is provided in the middle of the carrying line, and the lid 16 is inserted into the fitting space 15. After the means, the caulking die 1 is arranged.

  That is, in the figure, 1 is a caulking die 1. In the system shown in FIG. 5, the caulking die 1 is disposed above the conveyor 21, and a lift is placed below the caulking die 1 with the conveyor 22 interposed therebetween. 23 is arranged.

  Then, the lift 23 pushes up the battery case body 12 that has been conveyed to the lower side of the caulking die 1 and inserts the upper part of the battery case body 12 into the caulking hole 3. The lid 16 is caulked on the battery case body 12.

  In the figure, reference numeral 24 denotes laser welding means. The laser welding means 24 indicates a contact portion between the battery case body 12 and the lid 16 in the battery case 11 in which the lid 16 is caulked to the battery case body 11 by the lift 23. Used for laser welding.

  Further, in the figure, reference numeral 25 denotes a pressing means for taking out the battery case 11 inserted in the caulking hole 3 of the caulking die 1 from the caulking hole 3, and the pressing means 25 is rotated downward. By doing so, the lid 16 of the battery case 11 is hit, thereby causing the battery case 11 to drop downward from the caulking hole 3.

  In such a system, first, the peripheral edge of the lid 16 is placed in the fitting space 15 of the battery case body 12 that has been transported by the conveyor 22 in a state where battery components such as electrodes and electrolyte are filled. Thus, the lid 16 is inserted into the fitting space 15 of the battery case body 12 while the upper opening 13 of the battery case body 12 is closed with the lid 16.

  Next, when the battery case main body 12 with the lid 16 inserted in the fitting space 15 of the battery case main body 12 has been conveyed to the lower side of the caulking die 1, the conveyance of the conveyor 22 is stopped. At the same time, the battery case body 12 is raised by the lift 23, whereby the battery case body 12 is inserted into the caulking hole 3 of the caulking die 1 from below.

  The battery case body 12 is inserted until the upper end of the battery case body 12 is pressed to the inner peripheral side by at least the upper end portion of the taper portion 5, whereby the battery case is formed on the inner wall of the caulking hole 3 as described above. The upper end portion of the main body 12 is pressed toward the inner peripheral side, and the inner periphery of the upper end portion of the battery case main body 12 and the outer peripheral portion of the lid 16 are caulked and brought into close contact.

  Next, the inner peripheral portion of the upper end portion of the battery case main body 12 and the outer peripheral portion of the lid 16 are caulked by the inner wall of the caulking hole 3, and the lid 16 A laser beam is irradiated by the laser welding means 24 to a contact portion with the outer peripheral portion of the battery, whereby the lid 16 is joined to the battery case body 12 to complete a new battery.

  Thereafter, the battery case 11 is pressed downward by the pressing means 25, the completed new battery is returned onto the conveyor 22 by the lift 23, and then the conveyor is tact-fed. Through this procedure, the lid 16 is joined to the battery case main body 12 that has been newly transported below the crimping mold 1, and thereafter this process is repeated until there is no battery case main body 12 to be processed.

  In laser welding, spot welding may be performed first, and then all-around welding may be performed. According to this, production stability can be improved.

  FIG. 6 is a diagram showing a system 26 that transports the battery case body 12 using the rotary table 27. In this system 26, the battery case body 12 is transported by the rotary table 27. A system is provided with a joining area 29 provided with a crimping die, a lift, laser welding means, and the like.

  Then, in the load area 28, when the battery case body 12 filled with battery components such as electrodes and electrolyte is fixed on the table 27, and the battery case body 12 is conveyed to the joining area 29, the table 27 And the lid 16 is joined to the battery case body 12, and then the completed new battery is taken out from the line in the unload area 30. In the lid joining method of the present invention, In the system, a lid may be joined to the battery case body.

  In any case, the lid joining method of this embodiment employs the upward welding method, so that it is possible to shorten the welding time unlike the side surface welding method, and depending on the caulking die. The inner periphery of the upper end portion of the battery case main body and the outer peripheral portion of the lid are caulked, and in this state, the contact portion between the inner peripheral portion of the upper end portion of the battery case main body and the outer peripheral portion of the lid is joined by laser welding. For this reason, it is possible to sufficiently join the battery case body and the lid and achieve a good-looking finish without requiring high accuracy when manufacturing the battery case.

  Further, in the lid joining method of this embodiment, the crimping mold has a cooling means, while the lid is joined by pressing the upper end portion of the battery case body toward the inner peripheral side with the inner wall of the crimping hole. Since laser welding is performed with the inner peripheral portion of the upper end portion of the battery case main body and the outer peripheral portion of the lid being caulked, the cooling means provided in the caulking mold can absorb the heat of the laser beam, It is possible to prevent the battery components filled in the battery case from being adversely affected by heat.

  Therefore, according to the lid joining method of the present embodiment, the welding time is short, the productivity is high, the battery case is not required to have high accuracy, and the adverse effects of the welding heat can be suppressed. Is possible.

  In the above description, the case where the battery case 11 has a box shape has been described. However, the battery case does not necessarily have a box shape, and may have a cylindrical shape. In this case, the caulking hole in the caulking mold also has an upper end portion having a circular planar field of view and a tapered portion having a circular planar field of view and having a diameter that increases downward.

  In the above description, the case where the lid 16 is a flat plate has been described. In addition, as shown in the cross-sectional view of FIG. 7, the peripheral portion is inclined downward so that the cross-sectional shape becomes a trapezoid. The configured lid 16b may be used. In this case, when the upper end portion of the battery case main body 12 is pressed toward the inner peripheral side by the inner wall of the caulking hole 3, the inner periphery and the lid of the upper end portion of the battery case main body 12 are covered. The inclined part of the peripheral part in 16b is caulked.

  Then, since the lid 16b has a trapezoidal cross-sectional shape, when the peripheral edge portion of the lid 16b is pressed on the inner periphery of the upper end portion of the battery case body 12, the pressed peripheral edge portion is deformed to the inner diameter side. Since the lid 16b can be firmly pressed by the upper end portion of the battery case main body 12, even when there is an error in the thickness of the battery case main body 11, the error is sufficiently absorbed, The inner periphery of the upper end portion of the battery case body 12 and the outer periphery portion of the lid 16b can be caulked more reliably.

  FIG. 8 shows a case where the lid 16b shown in FIG. 7 is joined to the battery case body 11, and FIG. 8 (a) shows a state where the battery case body 12 is inserted into the caulking hole 3. 8B, the battery case main body 12 is forcibly advanced upward in the state of FIG. 8A so that the upper end portion of the battery case main body 12 is located on the inner peripheral side by the inner wall of the caulking hole 3. FIG. 2 shows a state in which the battery case body 12 is deformed toward the inner peripheral side by being pressed, and is crimped to the outer peripheral part of the lid 16b. In FIG. Even when a gap 17 is formed between the inner periphery and the outer periphery of the lid 16b, or when there is a difference in the gap 17, the difference in the gap 17 or the gap 17 is absorbed, and the battery The inner periphery of the upper end portion of the case body 12 and the outer periphery portion of the lid 16b It can be occupied to become.

  Furthermore, in the above description, the upper end portion of the battery case main body 12 has a form in which the stepped portion 14 is formed on the inner peripheral side by reducing the thickness and widening the inner diameter while maintaining the outer diameter. As shown in FIG. 9, for example, a step 18 b is formed on the inner peripheral side by forming a groove 18 that is convex toward the inner diameter side at a position that is slightly lower than the upper end portion of the battery case body 12 by a roller or the like. In this case, the upper end of the battery case body 12 may be deformed outward, and the lid 16b having the form shown in FIG. 7 may be used. Then, as described above, the battery Since it is possible to firmly press the lid 16b by the case body 12, as shown in FIG. 9B, an error in the battery case body 12 is absorbed, and a gap between the battery case body 12 and the lid 16b is formed. To lose Door can be.

  At this time, similarly to the case described above, it is possible to improve production stability by adopting a method in which spot welding is performed at the time of caulking and then the entire periphery of the lid 16b is welded in the next step.

  The present invention eliminates the need for high accuracy in manufacturing a battery case and reduces the adverse effects of welding heat in a method of welding a lid to the battery case body by an upward welding method. Therefore, the present invention can be applied to all methods for joining lids in containers in which a case and a lid are joined by welding.

DESCRIPTION OF SYMBOLS 1 Caulking metal mold 2 Mold body 3 Caulking hole 4 Upper end part of caulking hole 5 Tapered part of caulking hole 6 Peltier element 7 Lead wire 11 Battery case 12 Battery case main body 13 Openings 14 and 14b on the upper part of the battery case main body Step 15 Fitting space 16, 16b Lid 17 Gap 18 Groove 21, 26 Lid joining system 22 Conveyor 23 Lift 24 Laser welding means 25 Pressing means 27 Rotary table 28 Loading area 29 Joining area 30 Unloading area

Claims (1)

A stepped portion (14, 14b) is formed on the inner periphery of the upper end and a bottomed battery case body (12) having an opening (13) at the top, and a peripheral portion placed on the stepped portion (14, 14b) The lid (16, 16b) in the battery case having a lid (16, 16b) that closes the upper opening (13) of the battery case body (12) is attached to the battery case body (12). A method of joining,
A caulking hole (3) having a tapered portion (5) having an inner diameter that tapers toward the lower side and an inner diameter of the upper end portion that is smaller than the outer diameter of the upper end portion of the battery case body (12). Using a caulking mold (1) having a mold body (2) formed with a cooling means (6) provided in the mold body (2),
By placing the periphery of the lid (16, 16b) on the stepped portion (14, 14b) of the battery case body (12), the upper opening (13) of the battery case body (12) is covered with the lid (16 16b), placing the lid (16, 16b) on the upper part of the battery case body (12),
The battery case body (12) is inserted into the crimping hole (3) from the lower side of the crimping mold (1), and the upper end of the battery case body (12) is inserted at least by the upper end portion of the tapered portion (5). By inserting the battery case main body (12) until it is pressed toward the peripheral side, the upper end portion of the battery case main body (12) is pressed toward the inner peripheral side by the inner wall of the caulking hole (3). Clamp the inner periphery of the upper end of (12) and the outer periphery of the lid (16, 16b),
In this state, the battery case lid is joined by laser welding the contact portion between the inner peripheral portion of the upper end portion of the battery case body (12) and the outer peripheral portion of the lid (16, 16b). Method.

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