WO2018025549A1

WO2018025549A1 - Battery can and battery

Info

Publication number: WO2018025549A1
Application number: PCT/JP2017/024196
Authority: WO
Inventors: 啓藤井; 敏弘小田垣
Original assignee: 冨士発條株式会社
Priority date: 2016-08-02
Filing date: 2017-06-30
Publication date: 2018-02-08
Also published as: JP2018022586A; JP6085058B1; CN107681069A; CN207082565U

Abstract

A low surface part (14) and a step part (15) are formed in a range in the peripheral direction in which a gap (g) can occur between short-side surface parts (22) and corner surface parts (23) corresponding to a battery lid (20), among a pair of short-side wall parts (12, 12) and four corner parts (13, 13, 13, 13) of the battery can body (10), when engaged with the battery lid (20). The insertion limit position of the battery lid (20) is set in relation to the peripheral direction according to the contact between the step part (15) in a position differing from the low surface part (14), and the bottom-surface engagement part (25) of the battery lid (20). When the bottom-surface-side corner part (24) of the battery lid (20) has come into contact with the top end of the sidewall of the battery can body (10), the bottom-surface-side corner part (24) slides over the top end and guides the battery lid (20) toward the inner side of the sidewall, and makes contact with or faces the low surface part (14) in a position lower than the bottom-surface engagement part (25) in the vertical direction.

Description

Battery can and battery

The present invention relates to a battery can formed by welding a rectangular battery can body and a battery lid, and a battery including the battery can.

In recent years, battery-driven hybrid vehicles, electric vehicles, portable computers, and power tools are increasing. A typical example of such a battery is a lithium ion secondary battery. As a battery form of the battery, a rectangular battery including a metal rectangular battery can is widely used as a battery can that houses a power generation element. Yes. The battery can includes a battery can body formed in a bottomed rectangular tube shape and a battery lid joined to a side wall of the battery can body. The side wall of the battery can body and the peripheral edge of the battery lid are welded over the entire circumference.

In this type of battery can, a welding method of irradiating an energy beam from above is adopted as a method of welding the peripheral edge of the battery lid and the side wall of the battery can body. This is because when the beam is irradiated from the side of the battery can, it is disadvantageous because the welding length is extended and the welding time is increased, and the welding equipment is increased in size and cost. In order to enable welding by beam irradiation from above, the periphery of the battery lid has a shape that can be inserted into the inside of the side wall from above with respect to the battery can body. In order to stabilize the welding strength, it is necessary to make the fitting gap between the battery can body and the battery lid as small as possible and uniform. When the battery lid is inserted, if the peripheral edge of the battery lid is rubbed against the side wall of the battery can body, metal foreign matter may be generated and enter the housing space in the battery can body. This metal foreign matter can cause insulation failure. In order to suppress the generation of metallic foreign objects, a fitting gap in the longitudinal direction and the short direction is appropriately set between the periphery of the battery lid and the side wall of the battery can body. The smaller the fitting gap is to stabilize the welding strength, the higher the precision of the battery can body and battery lid parts and the accuracy of the assembly and manufacturing equipment. As a result, the equipment costs increase and the battery cans are assembled. This will lead to a decrease in cycle time, which will increase the manufacturing cost.

Further, the beam irradiation from above fixes the long side wall portion of the battery can body to a state in which the long side wall portion is pressed against the long side surface portion of the battery lid, and the pair of long side surface portions on the periphery of the battery lid and the side wall of the battery can body This is performed in a fitted state in which the pair of long side wall portions are in close contact with each other. On the other hand, between the short side surface portion and the corner surface portion of the battery lid and the short side wall portion and the corner portion of the battery can body, depending on the setting of the fitting gap and the flat deformation of the battery can body, it is perpendicular to the vertical direction. Gaps in various directions can occur. If the beam irradiated from above reaches the inside of the battery can body through the gap and damages the power generation element housed in the battery can body, or if spatter is scattered in the battery can body, it causes electrical failure. Can be. Moreover, even if the peripheral edge of the battery lid is lowered relative to the side wall of the battery can body, or conversely, it is liable to cause poor welding.

As measures for preventing the occurrence of such defects, conventionally, on the inner side surface of the short side wall portion or corner portion of the battery can body, a stepped portion disposed at least at one place and a lower surface portion disposed at a place other than the stepped portion. And are formed. The lower surface portion is below the battery lid at a position lower than the step portion. These stepped portion and lower surface portion prevent beam irradiation to the power generating element disposed in the housing space in the battery can body, and prevent spatter from scattering into the battery can body. In particular, the step portion is also a part that determines the insertion limit position of the battery lid. When the inserted battery cover abuts the stepped portion of the battery can body in the vertical direction, the battery cover is not inserted further downward. The insertion limit position of the battery lid is set to an appropriate position for welding. In addition, since it is difficult to cold-press the stepped portion to a uniform height in a long range in the circumferential direction, the cold-pressing is facilitated by adopting a lower surface portion (Patent Documents 1 and 2 below). .

Also, the battery lid of Patent Document 2 has a curved lower surface side corner that extends continuously from the periphery to the entire periphery in the circumferential direction. When the battery lid is inserted, when the lower surface side corner of the battery lid comes into contact with the upper end of the side wall of the battery can body, the lower surface side corner slides the upper end of the side wall and moves the battery lid to the inside of the side wall. Can lead. As described above, when the shape of the lower surface of the battery lid is provided with insertion guideability with respect to the upper end of the side wall of the battery can body, the insertability of the battery lid does not deteriorate even if the positional deviation occurs when the battery lid is transported. This is advantageous when the fitting gap between the peripheral edge of the battery lid and the side wall of the battery can body is set narrow. In other words, the narrower the fitting gap is, the easier it is for the lower surface of the battery lid to come into contact with the upper end of the side wall of the battery can body when misalignment occurs during transportation. It is possible to prevent the situation where the manufacturing facility is stopped due to the battery lid riding on the upper end of the side wall of the battery can body. As a result, the above-described component accuracy and the accuracy of assembly and manufacturing equipment can be avoided.

JP 2014-10936 A JP 2013-93119 A

However, in the battery can as in Patent Document 2, it is limited to the circumferential range in which the step portion of the battery can body can surely prevent the intrusion of the metal foreign matter and the scattering of the spatter. In the circumferential range where the lower surface portion is present, the space between the lower surface portion of the battery lid and the lower surface portion is relatively wide open into the battery can body. There is a problem that it is relatively easy to allow scattering.

In view of the above-mentioned background, the problem to be solved by the present invention is that the battery lid insertion guideability with respect to the rectangular battery can body is good in the shape of the battery lid, and the battery can body of metallic foreign matters at the time of insertion While preventing intrusion, scattering of spatter into the battery can body during welding and beam irradiation to the power generation element at the stepped portion and lower surface portion of the battery can body, The purpose is to further prevent intrusion and spatter scattering.

To achieve the above object, the present invention includes a battery can body and a battery lid joined to the battery can body. The battery can body includes a pair of long side wall portions and a pair of short side walls. A side wall portion, a side wall formed of four corners connecting the long side wall portion and the short side wall portion adjacent to each other in the circumferential direction, and the battery cover includes a pair of long side surface portions and , A peripheral edge comprising a pair of short side surface portions, the long side surface portion adjacent in the circumferential direction, and four corner surface portions connecting the short side surface portions, and the peripheral edge of the battery lid is the battery. The peripheral edge and the side wall can be welded in a fitted state inserted inside the side wall of the can main body, and at least one of the short side wall portion and the corner portion of the battery can main body, A step portion extending below the battery lid is formed, and the step in the vertical direction is provided at a place other than the step portion. A lower surface portion extending below the battery lid at a lower position, and the battery lid slides on the upper end of the battery can body when the battery lid contacts the upper end of the side wall of the battery can body during the insertion. It has a lower surface side corner portion that continues from the periphery of the battery lid to the lower side so as to guide the lid to the inside of the side wall, and a lower surface engaging portion that faces the stepped portion of the battery can body in the vertical direction. In the battery can where the insertion limit position of the battery lid with respect to the battery can body is determined by the contact between the stepped portion of the battery can body and the lower surface engaging portion of the battery lid, the lower surface side corner of the battery lid is The battery can is formed so as to contact or face the lower surface portion at a position lower than the lower surface engaging portion in the vertical direction.

According to the above configuration, the stepped portion of the battery can body and the lower surface engaging portion of the battery lid restrict the insertion of the battery lid to the battery can body to a limit position suitable for welding, and the metal foreign object battery at the time of insertion Intrusion into the can body can be prevented, and furthermore, the lower surface portion and step portion of the battery can body can prevent spatter scattering and beam irradiation to the power generation element during welding. it can.
In addition, since it is possible to obtain good insertion guideability by the lower side corner portion of the battery lid, the peripheral edge of the battery lid and the battery can body can be avoided while avoiding an increase in the accuracy of parts and assembly manufacturing equipment. It is also possible to stabilize the welding strength by setting a small fit between the side walls, and to prevent the aforementioned beam irradiation.
Further, since the lower surface side corner of the battery lid is in contact with or faces the lower surface portion of the battery can body at a position lower than the lower surface engaging portion, even if there is a misalignment when inserting the battery lid, After the portion guides the battery lid to the inside of the side wall of the battery can body, insertion restriction by the lower surface engaging portion and the step portion occurs. For this reason, there is no concern that metal foreign matter is generated due to the contact between the stepped portion and the lower surface side corner portion, but in the circumferential range where the lower surface portion exists, the contact between the lower surface side corner portion and the lower surface portion closes the two portions. In other words, the space between the two parts is narrower than that of the battery can of Patent Document 2. For this reason, this invention can prevent the penetration | invasion of the metal foreign material into a battery can main body, and scattering of a spatter more.

Preferably, the lower surface portion of the battery can body has a flat portion along a direction perpendicular to the vertical direction where the lower surface portion is positioned below a gap that may be formed between the side wall of the battery can body and the periphery of the battery lid. Good. Since the metal foreign matter and spatter are small ones that can enter the gap, it can be expected to stay on the flat portion along the direction perpendicular to the vertical direction below the gap. Accordingly, it is possible to further prevent intrusion of metal foreign matters and scattering of spatter.

Since the battery including the battery can according to the present invention is further prevented from intruding metal foreign matter into the battery can main body and scattered spatter, it is possible to prevent the occurrence of defective products.

As described above, the battery can according to the present invention adopts the above-described configuration to improve the insertion guideability of the battery lid with respect to the rectangular battery can main body in the shape of the battery lid, and to prevent the metal foreign matter at the time of insertion. While preventing intrusion into the battery can body, spatter scattering into the battery can body during welding and beam irradiation to the power generation element at the stepped portion and lower surface portion of the battery can body, Intrusion of metal foreign matter and spatter scattering can be further prevented.

(A) is a partial plan view of the battery can when the battery lid has been properly inserted into the battery can body according to the first embodiment of the present invention, and (b) is a view taken along the line Ib-Ib of (a). Partially enlarged sectional view, (c) is a partially enlarged sectional view taken along line Ic-Ic of (a). The whole perspective view which shows the external appearance which looked at the external appearance of the battery provided with the battery can which concerns on 1st embodiment of this invention from diagonally upward. The partial exploded perspective view which shows the mode before the insertion which made the battery cover of FIG. 1B is a partially enlarged cross-sectional view showing the insertion guide action by the lower surface side corner of the battery lid in the same cross section as FIG. Partial enlarged sectional view showing the irradiation direction and aiming position of the energy beam at the time of welding in the cross section taken along the line VV in FIG. Partial plan view of the battery can at the time when the battery lid has been properly inserted into the battery can body according to the second embodiment of the present invention. (A) is a partial plan view of the battery can when the battery lid has been properly inserted into the battery can body according to the third embodiment of the present invention, and (b) is a VIIb-VIIb line of (a). Partial enlarged sectional view

Hereinafter, a first embodiment as an example of a battery can and a battery according to the present invention will be described with reference to FIGS.

As shown in FIGS. 2 and 3, this battery is a rectangular sealed battery provided with a metal battery can having a rectangular parallelepiped outer shape.

This battery can is composed of a battery can body 10 formed in a bottomed rectangular tube shape and a battery lid 20 joined to the battery can body 10.

The battery lid 20 is inserted into the inside of the rectangular tubular side wall formed on the battery can body 10 from above with respect to the battery can body 10. In this battery, the side wall of the battery can body 10 and the peripheral edge of the battery lid 20 inserted inside the battery can body 10 are hermetically welded over the entire circumference. In the present invention, the vertical direction refers to a linear direction in which the battery can main body 10 and the battery lid 20 face each other. The circumferential direction refers to a direction that goes around the rectangular tubular side wall of the battery can body 10 in a direction perpendicular to the vertical direction. 1 (b), (c), FIG. 4 and FIG. 5, the vertical direction in the figure coincides with the vertical direction in the present invention.

In the housing space in the battery can body 10, a power generation element, an electrolytic agent, etc. (not shown) are housed. Positive and

negative electrode terminals

31, 31 electrically connected to the power generation element are attached to the battery lid 20. For example, in the case of a lithium ion secondary battery, examples of the power generation element include a flat wound electrode body. Examples of the electrolytic agent include non-aqueous electrolytic solutions, gels, and polymers. The battery lid 20 is formed with a safety valve and a sealing port.

As is clear from FIG. 2, the battery can body 10 and the battery lid 20 have shapes that are symmetrical in the longitudinal direction and the lateral direction, respectively. In the present invention, the longitudinal direction of the battery can body 10 and the battery lid 20 is an imaginary that defines the total length of the battery can body 10 and the battery lid 20 (the length of the object measured in a direction perpendicular to the vertical direction). The direction where two planes face each other. The short direction means a direction perpendicular to the long direction. Usually, the longitudinal direction and the lateral direction are not different between the battery can body 10 and the battery lid 20.

The battery can body 10 and the battery lid 20 are each integrally formed by cold forging press processing. Examples of the material of the battery can body 10 and the battery lid 20 include stainless steel, nickel-plated steel plate, and aluminum alloy. Aluminum alloy is preferable from the viewpoint of workability, corrosion resistance, and weight reduction. The battery can body 10 is formed into a bottomed cylindrical shape, for example, by a drawing process in which an aluminum alloy flat plate is sandwiched between upper and lower molds and deformed while applying a strong pressure. The battery lid 20 is formed by punching from a flat plate of aluminum alloy, for example, by press working.

As shown in FIGS. 2 and 3, the battery can body 10 includes a pair of long

side wall portions

11, 11, a pair of short

side wall portions

12, 12, a long side wall portion 11 adjacent to the circumferential direction, and a short side. It has a side wall composed of four

corners

13, 13, 13, 13 connecting the side wall 12. The side wall of the battery can body 10 forms a side surface and an opening of the battery can body 10.

Further, the battery can body 10 has a shape closed by a bottom portion (not shown) continuous with the lower end of the side wall. On the other hand, the upper end of the side wall of the battery can body 10 is an end surface that defines the height of the side wall with respect to the bottom portion (not shown). The upper end of the side wall of the battery can body 10 is continuous at the same height over the entire circumference.

The long side wall portion 11 has a solid portion that is continuous in the longitudinal direction between two

adjacent corner portions

13 and 13. The short side wall portion 12 has a solid portion that is continuous in the lateral direction between two

adjacent corner portions

13 and 13. The corner portion 13 has a solid portion that is continuous in an arc shape between the adjacent long side wall portion 11 and the short side wall portion 12.

The inner side surface and the outer side surface of the long side wall part 11 are along the longitudinal direction and the vertical direction, respectively.

The outer side surface of the short side wall portion 12 is along the short side direction and the vertical direction. The outer surface of the corner 13 has an R shape.

On the inner side surfaces of the short side wall portion 12 and the corner portion 13, a lower surface portion 14 is formed in which the thickness of the short side wall portion 12 and the corner portion 13 is gradually increased inward toward the lower side. Further, a stepped portion 15 protruding along the longitudinal direction is formed on the inner side surface of the short side wall portion 12.

The step portion 15 is a flat portion along the longitudinal direction at the center portion in the short side direction of the short side wall portion 12 among the short side wall portion 12 and the corner portion 13.

On the other hand, the lower surface portion 14 is a portion of the short side wall portion 12 and the corner portion 13 other than the step portion 15 in the circumferential direction (that is, both sides in the short side direction excluding the central portion of the short side wall portion 12 in the short direction). In the portion and the entire circumferential direction of the corner portion 13, and at a position lower than the step portion 15 in the vertical direction, the inclined portion is inclined inwardly downward. The inclination angle formed between the lower surface portion 14 and the lower direction gradually increases as the corner portion 13 approaches the short side wall portion 12 in the circumferential direction.

Among the inner side surfaces of the pair of short side wall portions 12 and the four corner portions 13, the portion that continues upward from the lower surface portion 14 and the portion that continues upward from the step portion 15 are each along the vertical direction.

The battery lid 20 includes a pair of long

side surface portions

21 and 21, a pair of short

side surface portions

22 and 22, and four corner surface portions that connect the long side surface portion 21 and the short side surface portion 22 adjacent in the circumferential direction. 23.

The peripheral edge of the battery lid 20 is composed of a side surface portion of the battery lid 20 that defines the fit between the battery lid 20 and the side wall of the battery can body 10 over the entire circumference.

The long side surface portion 21 is composed of a peripheral portion that defines a fit between the battery lid 20 and the long side wall portion 11 of the battery can body 10. The pair of long

side surface portions

21, 21 is a part that defines the length (full width) of the battery lid 20 in the short direction.

The short side surface portion 22 is formed of a peripheral portion that defines a fit between the battery lid 20 and the short side wall portion 12 of the battery can body 10. The pair of short

side surface portions

22, 22 is a part that defines the length (full length) of the battery lid 20 in the longitudinal direction.

The corner surface portion 23 is composed of a peripheral portion that defines the fitting between the battery lid 20 and the corner portion 13 of the battery can body 10.

The pair of long

side surface portions

21 and 21, the pair of short

side surface portions

22 and 22, and the four corner surface portions 23 are each along the vertical direction. The corner surface portion 23 has an R-surface shape connecting the adjacent long side surface portion 21 and short side surface portion 22.

A fitting gap is set between the peripheral edge of the battery lid 20 and the side wall of the battery can body 10 over the entire circumference. The fitting gap is set to a size of 0.05 mm or less in the longitudinal direction and is set to 0.10 mm or less in the short direction. In the transporting process of inserting the battery lid 20 into the inside of the side wall of the battery can body 10, the battery lid 20 is transported to above the battery can body 10. At this time, the transport target position is set so that the short side direction and the center in the long side direction of the battery lid 20 and the battery can main body 10 coincide with each other, but there is a limit in dimensional tolerance and positioning accuracy of the transport device. For this reason, when the battery lid 20 is inserted into the battery can main body 10 from above to a predetermined insertion limit position, the peripheral edge of the battery lid 20 and the side wall of the battery can main body 10 become an offset fit, Gaps can occur.

Further, as shown in FIGS. 1A to 1C and FIG. 3, the battery lid 20 includes a lower surface side corner portion 24 that overlaps the lower surface portion 14 of the battery can body 10 in the vertical direction, and a step difference between the battery can body 10. It has the part 15 and the lower surface engaging part 25 which faces an up-down direction.

The lower surface side corner portion 24 is a continuous portion with the lower surface engaging portion 25 among the pair of short

side surface portions

22 and 22 and the four corner surface portions 23 of the battery lid 20 (in the illustrated example, each short side surface portion. 22 from the lower edge region except for 22 in the short side direction). The lower surface side corner 24 is inclined so as to gradually approach the central axis of the battery lid 20 downward. The central axis of the battery lid 20 is an imaginary straight line in the vertical direction where a virtual plane that bisects the battery lid 20 in the longitudinal direction and a virtual plane that bisects the battery lid 20 in the lateral direction intersect. Say.

When the battery lid 20 is inserted into the inside of the side wall of the battery can body 10 as described above, the battery lid 20 is displaced from a predetermined position with respect to the battery can body 10 as shown by a two-dot chain line in FIG. When this happens, the lower surface side corner 24 of the battery lid 20 contacts the upper end of the side wall of the battery can body 10, and slides on the upper end to guide the battery lid 20 to the inside of the side wall (see the arrow in the figure). Finally, as shown by the solid line in the figure, the battery cover 20 is completely inside the side wall of the battery can body 10. The battery can body 10 and the battery lid 20 are accurate as shown in FIG. 4 as can be seen from the two-dot chain line in FIG. Is not sufficient for the longitudinal fit setting. For this reason, the insertion guideability of the battery lid 20 by the lower surface side corner portion 24 is important, but the arrangement and shape of the lower surface side corner portion 24 can guide the battery lid 20 to the inside of the side wall of the battery can body 10. What is necessary is just to determine suitably. In addition, the two-dot chain line battery lid 20 in the figure shows the insertion state that is offset to the maximum with respect to the side wall of the battery can body 10 that can occur with the above-described accuracy.

Further, as shown in FIG. 3, the battery lid 20 is formed with a second lower surface side corner portion 26 extending downward from the lower edge region of the pair of long

side surface portions

21 and 21. The second lower surface side corner portion 26 is continuous in the circumferential direction across the lower surface side corner portion 24 and has the same inclination angle as the lower surface side corner portion. The second lower surface side corner portion 26 is for avoiding the complicated shape of the battery lid 20, and may be omitted as appropriate. Of course, if the above-described component accuracy and positioning accuracy are insufficient even for the fitting setting in the short direction, the second lower surface side corner portion 26 is also important.

As shown in FIGS. 1 (a) to 1 (c) and FIG. 3, the lower surface engaging portion 25 has a flat surface shape that is higher than the lower surface side corner portion 24 in the vertical direction and is perpendicular to the vertical direction. Is formed. The lower surface engaging portion 25 extends in the longitudinal direction from the lower end of the central portion in the short direction of each short side surface portion 22. The lower surface engaging portion 25 is opened downward and is in a concave portion that is recessed from the lower surface side corner portion 24 and the periphery of the battery lid 20. It hits the corresponding step 15 in the vertical direction. The insertion limit position of the battery lid 20 with respect to the battery can body 10 is determined by the abutting contact of each lower surface engaging portion 25 and the corresponding stepped portion 15.

The lower surface engaging portion 25 and the lower surface side corner portion 24 as described above can be formed by press working of a mold that sandwiches a plate material up and down as in the conventional case, and the manufacture of the battery lid 20 is not particularly difficult.

In addition, the lower surface engaging portion 25 is set to have a larger dimension in the longitudinal direction and the shorter direction than the step portion 15 of the battery can body 10. This dimensional difference is set to be larger than the fitting gap. This is because, when the battery lid 20 is inserted, even if it is offset to the maximum within the range of the fitting gap, the edge of the stepped portion 15 does not come into contact with the lower surface side corner portion 24, and the generation of metallic foreign matter is prevented. It is for preventing.

The lower surface side corner 24 of the battery lid 20 is inclined so as to contact the lower surface portion 14 of the battery can body 10 at a position lower than the lower surface engaging portion 25 in the vertical direction, as shown in FIG. Yes. As shown in FIG. 1 (b), this contact occurs when each lower surface engaging portion 25 of the battery lid 20 is in an insertion limit state in which it vertically hits the corresponding stepped portion 15 of the battery can body 10. The lower surface portion 14 is set so as to occur in the entire circumferential range. In particular, in the circumferential range of the short side wall portion 12, the contact mode between the lower surface portion 14 and the lower surface side corner portion 24 is surface contact, and in the circumferential range of the corner portion 13, the lower surface portion 14 and the lower surface side corner portion 24 are in contact with each other. The contact mode gradually changes to line contact as the distance from the short side wall portion 12 in the circumferential direction increases.

Moreover, when it is in the above-mentioned insertion limit state, the lower surface side of the battery cover 20 is such that the peripheral edge of the battery cover 20 and the upper end of the side wall of the battery can body 10 have the same height over the entire circumference. The vertical difference between the corner portion 24 and the lower surface engaging portion 25, the vertical difference between the lower surface portion 14 and the step portion 15 of the battery can body 10, and the lower surface portion 14 and the lower surface side corner portion 24, respectively. An inclination angle with respect to the vertical direction is set.

When the pair of long

side wall portions

11, 11 of the battery can body 10 are entirely sandwiched in the short direction by a fixing jig (not shown) in the insertion limit state described above, each long side wall portion 11 is attached to the battery lid 20. It is made to closely adhere to the corresponding long side surface portion 21 in the lateral direction. As a result, the side wall of the battery can body 10 is flattened, and coupled with the above-described fitting gap, the gap between the short side surface portion 22 of the battery lid 20 and the short side wall portion 12 of the battery can body 10 A gap g in a direction perpendicular to the vertical direction may be generated between the corner surface portion 23 of the battery lid 20 and the corner portion 13 of the battery can body 10. Although not shown, the gap g between the corner surface portion 23 of the battery lid 20 and the corner portion 13 of the battery can body 10 is a short side surface portion 22 of the battery lid 20 and a short side wall portion of the battery can body 10. 12 is generated in a size that does not exceed the gap g.

Such a gap g is generated, each long side surface portion 21 of the battery lid 20 and the corresponding long side wall portion 11 of the battery can body 10 are in close contact with each other in the lateral direction, and the periphery of the battery lid 20 and the battery can The peripheral edge of the battery lid 20 and the side wall of the battery can body 10 are welded in a fitting state in which the upper end of the side wall of the main body 10 is substantially at the same height over the entire circumference. .

The aforementioned lower surface portion 14 of the battery can body 10 is in the aforementioned fitted state among the pair of short

side wall portions

12 and 12 and the four

corner portions

13, 13, 13 and 13 of the battery can body 10. It exists in the circumferential direction range in which the gap g can occur between the corresponding short side surface portion 22 and the corner surface portion 23, and extends below the lower surface side corner portion 24 of the battery lid 20 at a position lower than the gap g in the vertical direction. So that it is inclined inward.

Further, the step portion 15 of the battery can body 10 has the above-mentioned fitting state among the pair of short

side wall portions

12 and 12 and the four

corner portions

13, 13, 13 and 13 of the battery can body 10. Sometimes in the circumferential range in which the gap g can occur between the corresponding short side surface portion 22 and the corner surface portion 23, and in a position different from the lower surface portion 14 in the circumferential direction, and lower than the gap g in the vertical direction It protrudes inward so as to extend below the lower surface engaging portion 25 of the battery lid 20 at the position.

In the above-mentioned fitting state, the energy beam LS is irradiated at the target position indicated by black in FIG. Examples of the energy beam include a laser beam and an electron beam. Examples of the laser include a CW laser such as a fiber laser and a pulse laser such as a YAG laser. This irradiation proceeds along the circumferential direction. Thereby, the periphery of the battery lid 20 and the side wall of the battery can body 10 are joined in an airtight manner.

This battery can is as described above (see FIG. 1), and when the battery lid 20 is inserted into the inside of the side wall of the battery can body 10 from above with respect to the battery can body 10, the component accuracy and the assembly manufacturing apparatus Therefore, even when the lower surface side corner 24 of the battery lid 20 is rubbed against the upper end of the side wall of the battery can body 10, the inclined lower surface side corner 24 that continues downward from the periphery of the battery lid 20 is obtained. Since the battery lid 20 is smoothly guided to the inside of the side wall of the battery can body 10 due to the insertion guideability that makes sliding contact with the upper end of the side wall of the battery can body 10, It is possible to prevent stoppage, and by avoiding increasing the precision of parts accuracy and assembly manufacturing equipment, the welding strength is set by setting a small fit between the periphery of the battery lid and the side wall of the battery can body. Can also be stabilized.

Moreover, since this battery can can set fitting small by the insertion guideability of the lower surface side corner | angular part 24 of the battery cover 20, the fitting state which welds the periphery of the battery cover 20 and the side wall of the battery can main body 10 Even when a gap g may occur between the short side surface portion 22 and the corner surface portion 23 of the battery lid 20 and the corresponding short side wall portion 12 and the corner portion 13 of the battery can body 10, the gap g It is possible to prevent the beam generation to the power generation element in the battery can body 10 by setting it small.

In addition, when the battery lid 20 is inserted into the inside of the side wall of the battery can body 10 from above with respect to the battery can body 10, the battery can 10 and the battery can body 10 By contact with the corresponding stepped portion 15 in the vertical direction, the insertion limit position of the battery lid 20 with respect to the battery can body 10 can be determined at an appropriate position for welding by beam irradiation from above.

Further, since the lower surface side corner portion 24 of the battery lid 20 is in contact with the lower surface portion 14 of the battery can body 10 at a position lower than the lower surface engaging portion 25, the battery can is inserted when the battery lid 20 is inserted. Even when 20 is in contact with the upper end of the side wall of the battery can body 10, the lower surface side corner portion 24 leads the battery lid 20 to the inside of the side wall of the battery can body 10, so Insertion restrictions occur. For this reason, there is no fear that metal foreign matter is generated by contact between the step portion 15 and the lower surface side corner portion 24.

Further, in the battery can, the metal foreign matter generated when the battery lid 20 is inserted enters the battery can body 10 between the step portion 15 of the battery can body 10 and the lower surface engaging portion 25 of the battery lid 20. In particular, it is possible to prevent spatter generated during welding in the above-described fitting state from being scattered into the battery can body 10.

Furthermore, the battery can body 10 is located at a position where the lower surface side corner 24 of the battery cover 20 is lower than the lower surface engaging portion 25 when the battery cover 20 is inserted into the inside of the battery can body 10 in a predetermined manner. Since the lower surface portion 14 contacts the lower surface portion 14 and the space between the lower surface side corner portion 24 and the lower surface portion 14 is closed, the metal foreign matter generated when the battery lid 20 is inserted also enters the battery can body 10 during this time. In particular, it is possible to prevent spatter generated during welding in the above-described fitting state from being scattered into the battery can body 10. Therefore, this battery can can prevent the invasion of metal foreign matter into the battery can body 10 and the scattering of the spatter as compared with the conventional example.

In addition, since this battery is further prevented from intruding metal foreign matter into the battery can body 10 and spatter scattering, it is possible to prevent the generation of defective products.

A second embodiment according to the present invention will be described with reference to FIG. Hereinafter, only differences from the first embodiment will be described.

As shown in FIG. 6, the battery can according to the second embodiment has a plurality of stepped

portions

15, 15 formed on the battery can body, while a plurality of lower surface engaging portions 25 are arranged corresponding to the battery lid. It is different from the first embodiment in that it is formed. Thus, if the step portion 15 is formed in a distributed manner at a plurality of locations in the short direction, the posture stability of the battery lid 20 can be further improved.

A third embodiment according to the present invention will be described with reference to FIG. Hereinafter, only differences from the first embodiment will be described.

In the battery can according to the third embodiment, a flat surface portion 41 along a direction perpendicular to the vertical direction is formed in a side wall of the battery can main body at a position below the gap g and different from the step portion 15 in the circumferential direction. However, it is different from the first embodiment in that the lower surface portion 42 is formed from the flat surface portion 41. The flat portion 41 is set to a width equivalent to the width of the gap g above it. Since the metal foreign matter and spatter are small ones that can enter the gap g, it can be expected to remain on the flat portion 41 along the direction perpendicular to the vertical direction below the gap g. Therefore, this battery can can further prevent intrusion of metal foreign matters and scattering of spatter.

Further, in this battery can, the inclination angle of the lower surface portion 42 is slightly changed with the formation of the flat portion 41. Accordingly, when the lower surface engaging portion 25 and the stepped portion 15 are in the insertion limit state in which they vertically butt, the lower surface side corner portion 24 of the battery lid does not substantially contact the lower surface portion 42 and is narrower than the gap g. It is also different from the first embodiment in that it faces the lower surface portion 42 at intervals. The facing interval is defined between the intersecting edges of the flat surface portion 41 and the lower surface portion 42, and is set sufficiently smaller than the gap g. Since the metal foreign matter and spatter are small enough to enter the gap g, if the lower surface side corner 24 and the lower surface portion 42 are opposed to each other at a distance narrower than the gap g, the metal foreign matter or spatter is discharged from the flat portion 41 to the battery. Even if it is about to fall into the housing space of the can body, it can be caught by the lower surface side corner portion 24 to prevent entry and scattering.

The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. Therefore, the scope of the present invention is defined by the terms of the claims, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

For example, the second embodiment and the third embodiment may be combined.

Alternatively, the stepped portion may be formed at each corner of the battery can body, and the lower surface portion may be formed only on the short side wall portion. Moreover, you may add a level | step-difference part and a low-order surface part to the long side side wall part of a battery can main body. Further, although all or a part of the lower surface portion is formed in the inclined portion, the entire lower surface portion may be formed in a flat portion perpendicular to the vertical direction.

The fitting between the battery lid and the battery can body is not limited to the case where a gap is set, and the battery lid may be press-fitted and fitted inside the side wall of the battery can body. In short, in terms of component accuracy and positioning accuracy of the assembly manufacturing equipment to be used, the manufacturing equipment by generating metal foreign matter and riding on the battery cover is within the range in which the insertion of the battery cover can be guided by the lower side corners of the battery cover. Therefore, it is possible to set the fitting gap as small as possible within the range, or to set a tightening allowance for the fitting.

DESCRIPTION OF SYMBOLS 10 Battery can main body 11 Long side side wall part 12 Short side side wall part 13 Corner |

angular part

14, 42 Low level surface part 15 Step part 20 Battery cover 21 Long side side part 22 Short side side part 23 Corner side part 24 Lower surface side corner part 25 Lower surface engagement Part 41 Plane part g Clearance

Claims

A battery can body (10) and a battery lid (20) joined to the battery can body (10);
The battery can body (10) includes a pair of long side wall parts (11), a pair of short side wall parts (12), the long side wall part (11) adjacent to the circumferential direction, and the short side wall parts. (12) having four side walls that connect the four corners (13),
The battery cover (20) includes a pair of long side surface portions (21), a pair of short side surface portions (22), the long side surface portion (21) adjacent to the circumferential direction, and the short side surface portions ( 22) having a peripheral edge composed of four corners (23) connecting the two,
The peripheral edge of the battery lid (20) can be welded to the peripheral edge and the side wall in a fitted state in which the peripheral edge of the battery lid (20) is inserted inside the side wall of the battery can body (10).
A step portion (15) extending below the battery lid (20) is formed in at least one of the short side wall portion (12) and the corner portion (13) of the battery can body (10), A lower surface portion (14, 42) extending below the battery lid (20) at a position lower than the step portion (15) in the vertical direction is formed at a place other than the step portion (15),
When the battery lid (20) comes into contact with the upper end of the side wall of the battery can body (10) during the insertion, the battery lid (20) is slid on the upper end to guide the battery lid (20) to the inside of the side wall. A lower surface side corner (24) continuous from the periphery of the battery lid (20) to the lower side, and the stepped portion (15) of the battery can body (10) and a lower surface engaging portion (25) facing in the vertical direction. Have
Insertion limit position of the battery lid (20) with respect to the battery can body (10) by contact of the stepped portion (15) of the battery can body (10) and the lower surface engaging portion (25) of the battery lid (20). In battery cans where
The lower surface engaging portion (25) of the battery lid (20) is formed at a position higher than the lower surface side corner (24) of the battery lid (20) in the vertical direction.
The lower surface side corner (24) of the battery lid (20) is formed so as to contact or face the lower surface portion (14, 42) at a position lower than the lower surface engaging portion (25) in the vertical direction. A battery can characterized by that.
Up and down direction where the lower surface portion (42) of the battery can body (10) is located below a gap (g) that may be formed between the side wall of the battery can body (10) and the periphery of the battery lid (20). The battery can according to claim 1, wherein the battery can has a flat portion (41) along a direction perpendicular to the vertical direction.
The battery can according to claim 2, wherein the lower surface side corner (24) of the battery lid (20) is formed so as to face the lower surface portion (42) at a smaller interval than the gap (g). .
The lower surface engaging portion (25) of the battery lid (20) is formed in a flat surface shape along a direction perpendicular to the vertical direction, and the lower surface side corner (24) and the battery lid (20). ) In the recess recessed from the peripheral edge of the battery can and opened downward, and set to a large size in the longitudinal direction and the lateral direction compared to the stepped portion (15) of the battery can body (10). Has been
The lower surface side corner portion (24) of the battery lid (20) is the lower surface engaging portion of the pair of short side surface portions (22) and four corner surface portions (23) of the battery lid (20). The battery can according to any one of claims 1 to 3, wherein the battery can extends downward from all lower edge regions except a continuous portion with (25).
A battery comprising the battery can according to any one of claims 1 to 4.