JP5639558B2 - Coupling structure of metal plate and metal shaft and electrode structure of sealed battery - Google Patents

Description

  The present invention relates to a coupling structure of a metal plate and a metal shaft, and an electrode structure of a sealed battery using the same.

  In recent years, a sealed battery such as a lithium ion battery that is lightweight and has a high energy density has attracted attention as a power source for mounting on a vehicle. For example, in Patent Document 1, an electrode body and an electrolyte are accommodated in a battery case, and an axial electrode terminal is an external terminal composed of a terminal through hole provided in the battery case and a metal plate disposed on the surface of the battery case. The terminal through-holes provided in the case are sequentially passed through and drawn out from the inside of the case. However, since the metal plate is also provided with the terminal insertion hole, there is a problem that the seal structure for suppressing leakage of the electrolyte inside the battery case to the outside is complicated.

By the way, as a technique for coupling the metal shaft to the through hole of the metal plate, the small diameter end portion of the metal shaft is inserted into the through hole of the metal plate, and the tip of the small diameter end portion is slightly protruded from the surface of the metal plate. The caulking method is generally used in which the projected tip is crushed by a press and engaged with the periphery of the through hole.
On the other hand, a technique for caulking a metal shaft without providing a through hole in a metal plate has been proposed. For example, in Patent Document 2, the end of the metal shaft, in which a large number of minute vertical grooves and transverse grooves intersecting with this are formed on the outer periphery, or a knurled line is formed on the bottomed hole of the metal plate. At the same time, the cylindrical caulking punch fitted to the outer periphery of the end of the metal shaft is moved along the metal shaft, so that the meat that forms the edge of the bottomed hole in the metal plate is Techniques for pushing into grooves and transverse grooves have been proposed. On the other hand, there is a welding method in which the end surface of the metal shaft is brought into contact with the surface of the metal plate, and the contact surface is melted and joined.

JP 2010-282848 A JP 59-147724 A

In the above-described welding method, there is an influence of thermal distortion and the like, and the amount of penetration of the metal shaft is not constant, so the position accuracy of the metal shaft with respect to the metal plate is not very good. Moreover, the manufacturing cost is high.
Patent Document 2 has the following drawbacks. That is, when it is necessary to consider severe conditions such as vibration when mounted on a vehicle or the like, a minute vertical groove or knurled may cause loosening of the metal shaft due to the influence of vibration or the like. In addition, since the caulking punch is used, variation in the positional accuracy between the metal shaft and the caulking punch affects the caulking amount, and the positional accuracy of the metal shaft with respect to the metal plate may be deteriorated. Furthermore, it is necessary to periodically replace the caulking punch with a new one, which increases the manufacturing cost.

  Accordingly, an object of the present invention is to provide a metal plate / metal shaft coupling structure and a sealed battery electrode structure including the same, which have a high coupling force, excellent positional accuracy, and are inexpensive.

To achieve the above object, the invention of claim 1 is a metal having a first surface (2) and a second surface (3) parallel to each other, and a bottomed hole (4) is formed in the first surface. A plate (1; 1A) and a metal shaft (5; 5A) press-fitted into the bottomed hole, and the metal shaft is in contact with the first surface and restrains deformation of the first surface. A main body portion (6) having a shoulder portion (8), and a press-fit end portion (7) press-fitted into the bottomed hole, wherein the press-fit end portion is provided adjacent to the main body portion and the main body A polygonal part (9) arranged in the projection space in the axial direction (X1) of the part and an end surface (102) in contact with the bottom (42) of the bottomed hole, the axial direction of the polygonal part A tapered guide portion (10) disposed in the projection space of the guide portion and the guide portion and the polygonal portion are connected to form a constricted space (S1) between the guide portion and the polygonal portion. And the polygonal part bites into the inlet edge by plastically deforming the inlet edge (41) of the bottomed hole to the second surface side, metal plate, said constricted saw including a plastically deformed portion (12) having entered the space, the second surface of the metal plate, outside the projection space in the axial direction of the guide portion, the plastic deformation by press-fitting of the polygonal section Provided is a coupling structure (A) of a metal plate and a metal shaft, in which a mark (13) is formed so as to be visible .

In addition, although the alphanumeric character in a parenthesis represents the corresponding component etc. in embodiment mentioned later, this does not mean that this invention should be limited to those embodiment as a matter of course. The same applies hereinafter.
Moreover, the flat screen parallel to the 1st surface may be sufficient as the division screen (91) of the said polygon part which divides the said constriction space like Claim 2.

According to a third aspect of the present invention, the section screen (101) of the guide section that divides the constricted space may be a flat surface parallel to the first surface .

According to a fourth aspect of the present invention, there is provided a metal plate (1A) as an external terminal having a back surface as a first surface and a front surface as a second surface and having a bottomed hole formed in the back surface, and a battery case ( 21) A metal shaft (5A) as an internal terminal drawn out from the inside and press-fitted into the bottomed hole, and the metal shaft is in contact with the first surface and restrains deformation of the first surface. A main body portion having a shoulder portion and a press-fit end portion press-fitted into the bottomed hole, the press-fit end portion being provided adjacent to the main body portion and in an axial projection space of the main body portion A polygonal portion disposed; a tapered guide portion having an end surface in contact with the bottom of the bottomed hole; and disposed in a projection space in an axial direction of the polygonal portion; the guide portion; A narrow-diameter portion connecting a square portion and forming a constricted space between the guide portion and the polygon portion, and the polygon Encloses the inlet edge of the bottomed hole plastically toward the second surface and bites into the inlet edge, and the metal plate includes a plastically deformed part that enters the constricted space. (20) An electrode structure (B) is provided.

According to the first aspect of the present invention, the plastic deformation portion of the metal plate enters the constricted space of the metal shaft to prevent the metal shaft from being pulled out in the axial direction, and the polygonal portion is a bottomed hole of the metal plate. Since the rotation of the metal shaft is reliably regulated by biting into the entrance edge of the metal plate, the coupling force of the metal shaft to the metal plate can be remarkably increased.
Further, since the polygonal portion of the metal shaft itself bites into the inlet edge of the bottomed hole, a separate jig for pressing the inlet edge in the press-fitting direction (for example, a caulking punch in Patent Document 2) is unnecessary. . Therefore, unlike Patent Document 2, it is not affected by variations in the positional accuracy between the caulking punch and the shaft, so that the accuracy of the caulking amount is good, and as a result, the positional accuracy of the metal shaft with respect to the metal plate can be improved. Further, it is not necessary to replace the caulking punch, and the manufacturing cost can be reduced.
In addition, on the second surface of the metal plate, plastic deformation marks due to the press-fitting of the polygonal part are formed so as to be visible outside the projection space in the axial direction of the guide part, so that it is possible to omit the inspection relating to the press-fitting process. Manufacturing costs can be reduced.

Furthermore, since the hole of the metal plate is a bottomed hole, it can be suitably used when sealing properties are required on the front and back of the metal plate.
According to the invention of claim 2, since the section screen of the polygonal section that divides the constricted space is a flat surface parallel to the first surface, the squareness of the metal axis with respect to the metal plate can be realized with high accuracy. .
According to the invention of claim 3, since the section screen of the guide section that divides the constricted space is a flat surface parallel to the first surface, the squareness of the metal axis with respect to the metal plate can be realized.

According to the invention of claim 4, the same effect as that of claim 1 can be obtained. That is, the coupling force of the internal terminal (metal shaft) with respect to the external terminal (metal plate) is high, the positional accuracy of the internal terminal (metal shaft) with respect to the external terminal (metal plate) is high, and the manufacturing cost can be reduced. it can. Moreover, since the terminal through hole is not provided in the metal plate, it is possible to realize an electrode structure of a sealed battery that can simplify a sealing structure for preventing leakage of an internal electrolyte or the like.

It is a partial fracture front view of the connection structure of a metal plate and a metal axis concerning one embodiment of the present invention. It is a disassembled perspective view before the coupling | bonding of a metal plate and a metal shaft. FIG. 3A is a side view of the metal shaft, and FIG. 3B is a front view of the metal shaft. 4A is a side view of the metal shaft viewed from a different angle from FIG. 3A, and FIG. 4B is a side view of the metal shaft viewed from a different angle from FIG. 4B. FIG. FIGS. 5A to 5C are partial cross-sectional front views sequentially showing steps of joining the metal plate and the metal shaft. It is the schematic of the surface of the metal plate after a coupling | bonding. It is a schematic perspective view of the sealed battery which concerns on another embodiment of this invention. It is sectional drawing of the electrode structure of the sealed battery of FIG.

Preferred embodiments of the present invention will be described with reference to the accompanying drawings.
FIG. 1 is a partial sectional front view of a metal plate / metal shaft coupling structure A according to an embodiment of the present invention. With reference to FIG. 1, the metal plate 1 has the 1st surface 2 and the 2nd surface 3 which are mutually parallel and oppose the plate | board thickness direction T1. A bottomed hole 4 is formed in the first surface 2 of the metal plate 1. As shown in FIG. 2, the metal shaft 5 is press-fitted into the bottomed hole 4 of the first surface 2 of the metal plate 1, so that the metal plate-metal shaft coupling structure A shown in FIG. 1 is configured. . The metal plate 1 is made of, for example, aluminum, and the metal shaft 5 is made of, for example, copper, and the hardness of both is relatively close.

  As shown in FIGS. 1, 2, 3 (a) and 3 (b) and FIGS. 4 (a) and 4 (b), the metal shaft 5 is formed in a hollow round bar-shaped main body 6 and a bottomed hole 4. And a press-fit end 7 that is press-fitted. The main portion 6 of the metal shaft 5 has a shoulder portion 8 that abuts against the first surface 2 of the metal plate 1 and restrains deformation of the first surface 2. The shoulder 8 is formed on a flat surface parallel to the first surface 2. The hollow portion of the main body portion 6 is opened to the side opposite to the press-fit end portion 7.

  The press-fit end portion 7 has, for example, a substantially rectangular polygonal portion 9, a tapered guide portion 10, and a small diameter portion 11 sequentially from the main body portion 6 toward the tip end side of the metal shaft 5. . The polygonal portion 9 is provided adjacent to the main body 6 and is disposed in the projection space in the axial direction X1 of the main body 6 as shown in FIGS. 3 (a) and 4 (a). As shown in FIG. 1, the polygonal portion 9 bites into the inlet edge 41 by plastically deforming the inlet edge 41 of the bottomed hole 4 toward the second surface 3. In the present embodiment, the polygonal portion is substantially rectangular, but it may be a triangle or a pentagon or more.

The small-diameter portion 11 connects the polygonal portion 9 and the guide portion 10, and forms a constricted space S <b> 1 between the polygonal portion 9 and the guide portion 10. The metal plate 1 includes a plastic deformation portion 12 that has entered the constricted space S1. The section screen 91 of the polygonal section 9 and the section screen 101 of the guide section 10 that define the constricted space S <b> 1 are formed by flat surfaces parallel to the first surface 2.
As shown in FIG. 1, the guide portion 10 has an end face 102 that is in contact with the bottom 42 of the bottomed hole 4, and as shown in FIGS. 3 (a) and 4 (a), the polygonal portion 9. It is arranged in the projection space in the axial direction X1. The bottom 42 of the bottomed hole 4 and the end surface 102 of the guide portion 10 are formed by flat surfaces parallel to the first surface 2.

  A predetermined value within a range of 4 to 6 mm, for example, is employed as the diameter of the hollow round bar-shaped main body 6. As the diameter of the guide portion 10, a predetermined value within a range of 3 to 4 mm, for example, is adopted. For example, the length of one side of the polygonal portion 9 forming a substantially rectangular shape is substantially equal to the diameter of the guide portion 10. The height (axial length) of the press-fit end portion 7 is set to be, for example, about 0.4 to 0.6 mm smaller than the plate thickness (for example, 2 to 3 mm) of the metal plate 1. The height (axial length) of the polygonal portion 9 is set to, for example, ½ of the height (axial length) of the press-fit end portion 7. The diameter of the small diameter part 11 is made smaller than the diameter of the guide part 10 by about 1-2 mm, for example. The axial length of the small diameter part 11 is 0.4 to 0.5 mm, for example.

  Next, FIGS. 5A to 5C sequentially show the process of joining the metal plate 1 and the metal shaft 5 together. The upper and lower sides in FIG. 5 may be opposite to the actual vertical direction. As shown in FIG. 5A, the metal shaft 5 is pressed from the press-fit end portion 7 side into the bottomed hole 4 of the metal plate 1 in a state where the second surface 3 is received by a receiving portion of a press machine (not shown). Push in. The diameter D1 of the bottomed hole 4 before the metal shaft 5 is press-fitted is set to be equal to or slightly larger than the diameter D2 of the guide portion 10 (D1 ≧ D2). Further, the diameter D1 of the bottomed hole 4 before the metal shaft 5 is press-fitted is equal to or slightly smaller than the diameter D3 of the circumscribed circle of the polygonal part (D1 ≦ D3).

Therefore, as shown in FIG. 5 (b), when the press-fit end 7 is being pushed into the bottomed hole 4, the meat around the inlet edge 41 of the bottomed hole 4 pushed by the polygonal part 9 is removed. , Flows into the constricted space S1.
Next, as shown in FIG. 5 (c), a sufficient amount of meat enters the constricted space S 1 between the polygonal portion 9 and the guide portion 10, and the end face 102 made of a flat surface of the guide portion 10. However, by abutting against the bottom 42 of the bottomed hole 4, the press-fitting of the metal shaft 5 is completed, and the metal plate / shaft coupling structure A is completed.

  As shown in FIG. 6, on the second surface 3 of the metal plate 1 after completion of press-fitting, the polygonal portion 9 is outside the projection space P in the axial direction X1 of the guide portion 10 (the direction orthogonal to the paper surface in FIG. 6). The plastic deformation trace 13 due to the press-fitting is formed so as to be visible. The plastic deformation trace 13 is such that a change in the gloss of the second surface 3 can be seen, and the flatness of the second surface 3 is maintained at, for example, an accuracy of 5/100 or less.

According to the present embodiment, as shown in FIG. 1, the plastic deformation portion 12 of the metal plate 1 enters the constricted space S1 of the metal shaft 5 to prevent the metal shaft 5 from being pulled out in the axial direction X1. At the same time, since the polygonal portion 9 bites into the inlet edge 41 of the bottomed hole 4 of the metal plate 1 and reliably controls the rotation of the metal shaft 5, the coupling force of the metal shaft 5 to the metal plate 1 is markedly increased. Can be high.
Further, since the polygonal portion 9 itself of the metal shaft 5 bites into the inlet edge 41 of the bottomed hole 4, a separate jig for pressing the inlet edge 41 in the press-fitting direction (for example, the caulking punch of Patent Document 2) ) Is not required. Therefore, unlike Patent Document 2, it is not affected by variations in the positional accuracy between the caulking punch and the shaft, so that the accuracy of the caulking amount is good, and as a result, the positional accuracy of the metal shaft 5 with respect to the metal plate 1 can be improved. . Further, it is not necessary to replace the caulking punch, and the manufacturing cost can be reduced.

Furthermore, since the hole of the metal plate 1 is the bottomed hole 4, it can be suitably used when sealing properties are required on the front and back of the metal plate 1.
Moreover, since the section screen 91 of the polygonal part 9 that partitions the constricted space S1 is a flat surface parallel to the first surface 2, the squareness of the metal shaft 5 with respect to the metal plate 1 can be realized with high accuracy. Moreover, since the section screen 101 of the guide portion 10 that partitions the constricted space S1 is a flat surface parallel to the first surface 2, the squareness of the metal shaft 5 with respect to the metal plate 1 can be accurately realized from this point. be able to. Further, since the bottom 42 of the bottomed hole 4 and the end surface 102 of the guide portion 10 are flat surfaces parallel to the first surface 2, the squareness of the metal shaft 5 with respect to the metal plate 1 can be accurately realized from this point. can do.

Further, as shown in FIG. 6, on the second surface 3 of the metal plate 1, a plastic deformation mark 13 due to the press-fitting of the polygonal portion 9 is formed so as to be visible outside the projection space in the axial direction X1 of the guide portion 10. Therefore, it is possible to omit the inspection relating to the press-fitting process, and the manufacturing cost can be reduced.
Next, FIG. 7 shows an electrode structure B of a sealed battery to which a coupling structure A of a metal plate and a metal shaft is applied. As shown in FIG. 7, the sealed battery 20 includes, for example, a battery case 21 as an outer container having a rectangular parallelepiped shape, and a metal plate 1 </ b> A as a pair of external terminals arranged on the terminal arrangement surface 22 of the battery case 21. The electrode rod 23 is formed to protrude from the second surface 3 as the surface of the metal plate 1A. One metal plate 1A and the electrode rod 23 formed thereon constitute a positive electrode, and the other metal plate 1A and the electrode rod 23 formed thereon constitute a negative electrode.

As shown in FIG. 8, a recess 24 is formed in the terminal arrangement surface 22 of the battery case 21, and at least a part of the metal plate 1 </ b> A is accommodated in the recess 24. Between the bottom 241 and the inner wall surface 242 of the recess 24 and the first surface 2 (back surface) and the side surface 25 of the metal plate 1A opposite to the bottom 241, an insulating seal member 26 made of, for example, rubber is interposed.
A terminal through hole 27 is formed in the battery case 21, and the press-fit end portion 7 of the metal shaft 5A as an internal terminal is inserted into the terminal insertion hole 27, and the first surface 2 (back surface 2) of the metal plate 1A. The bottomed hole 4 is press-fitted. The seal member 26 is elastically sandwiched between the first surface 2 of the metal plate 1A and the bottom 241 of the recess 24 of the battery case 21 in a state of surrounding the metal shaft 5A inserted through the terminal through hole 27. Thus, the penetrating portion of the metal shaft 5A in the metal plate 1A is sealed.

  According to this embodiment, the same effect as the embodiment of FIGS. That is, the coupling force of the internal terminal (metal shaft 5A) to the external terminal (metal plate 1A) is high, the positional accuracy of the internal terminal (metal shaft 5A) to the external terminal (metal plate 1A) is high, and the manufacturing cost is reduced. Can be cheap. In addition, since the terminal through hole is not provided in the metal plate 1A, it is possible to simplify the seal structure for preventing leakage of the internal electrolyte and the like, and to realize an inexpensive sealed battery electrode structure B. it can.

  The present invention is not limited to the above-described embodiment. For example, as a material for a metal plate or a metal shaft, a material having excellent conductivity such as aluminum, copper, steel, stainless steel (SUS), or the like is used. it can. In addition, various modifications can be made within the scope of the claims of the present invention.

  DESCRIPTION OF SYMBOLS 1 ... Metal plate, 1A ... Metal plate (external terminal), 2 ... 1st surface, 3 ... 2nd surface, 4 ... Bottomed hole, 41 ... Entrance edge part, 42 ... Bottom, 5 ... Metal shaft, 5A ... Metal Axis (internal terminal), 6 ... main part, 7 ... press-fit end, 8 ... shoulder, 9 ... polygonal part, 91 ... section screen, 10 ... guide section, 101 ... section screen, 102 ... end face, 11 ... fine Diameter portion, 12 ... plastic deformation portion, 13 ... plastic deformation mark, 20 ... sealed battery, 21 ... battery case, 22 ... terminal arrangement surface, 23 ... electrode rod, 24 ... concave, 241 ... bottom surface, 242 ... inner wall surface, 25 ... side face, 26 ... sealing member, 27 ... terminal through hole, A ... metal plate / metal shaft coupling structure, B ... sealed battery electrode structure, D1 ... (guide portion) diameter, D2 ... (before press-fitting) Diameter (bottomed hole), D3 (diameter of the circumscribed circle of the polygonal part), P ... projection space, S1 ... constriction space, T1 ... plate thickness direction, X1 ... axial direction

Claims (4)

A metal plate having a first surface and a second surface parallel to each other and having a bottomed hole formed in the first surface;
A metal shaft press-fitted into the bottomed hole,
The metal shaft includes a main body having a shoulder that abuts against the first surface and restrains deformation of the first surface, and a press-fit end that is press-fitted into the bottomed hole,
The press-fit end portion has a polygonal portion provided adjacent to the main body portion and disposed in a projection space in the axial direction of the main body portion, and an end surface in contact with the bottom of the bottomed hole. A tapered guide portion disposed in the projection space in the axial direction of the rectangular portion, and a narrow portion that connects the guide portion and the polygon portion to form a constricted space between the guide portion and the polygon portion. A diameter portion, and
The polygonal part bites into the inlet edge by plastically deforming the inlet edge of the bottomed hole to the second surface side,
The metal plate is viewed including the constricted plastically deformed portion that enters into the space,
A coupling structure of a metal plate and a metal shaft , wherein a plastic deformation mark due to press-fitting of the polygonal portion is formed on the second surface of the metal plate so as to be visible outside the projection space in the axial direction of the guide portion .   The metal plate and metal shaft coupling structure according to claim 1, wherein a section screen of the polygonal section that divides the constricted space is a flat surface parallel to the first surface.   The metal plate / metal shaft coupling structure according to claim 1, wherein a section screen of the guide section that divides the constricted space is a flat surface parallel to the first surface. A metal plate as an external terminal having a back surface as a first surface and a surface as a second surface, and a bottomed hole formed in the back surface;
With a metal shaft as an internal terminal pulled out from the battery case and press-fitted into the bottomed hole,
The metal shaft includes a main body having a shoulder that abuts against the first surface and restrains deformation of the first surface, and a press-fit end that is press-fitted into the bottomed hole,
The press-fit end portion has a polygonal portion provided adjacent to the main body portion and disposed in a projection space in the axial direction of the main body portion, and an end surface in contact with the bottom of the bottomed hole. A tapered guide portion disposed in the projection space in the axial direction of the rectangular portion, and a narrow portion that connects the guide portion and the polygon portion to form a constricted space between the guide portion and the polygon portion. A diameter portion, and
The polygonal part bites into the inlet edge by plastically deforming the inlet edge of the bottomed hole to the second surface side,
The metal plate includes an electrode structure of a sealed battery including a plastic deformation portion that enters the constricted space.

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