JPH0589861A - Battery can and its manufacture - Google Patents

Abstract

PURPOSE:To increase the strength of a sealing part, heighten the fastening force for a sealing cap, enhance the sealing performance, and construct a battery in a light weight by forming the sealing part of a battery can with a larger wall thickness than the other parts of the side circumferential wall. CONSTITUTION:The sealing part 2e of a cylindrical battery can 2 is formed with a larger wall thickness than the other parts of its side circumferential wall 2d, and the peripheral surface 2b and internal surface 2c are formed flat and smooth. To form a battery with this can 2, a pos. and a neg. electrode plate are accommodated in the can 2, and thereto an electrolyte is added. If this is followed by a movement in the centripetal direction while a relative rotation is made along the periphery of the part 2e by the use of a pressurization roller, the edge of the part 2e is folded to inside the can 2 in its radial direction. Therein the part 2e is formed with a larger wall thickness than the other parts of the side circumferential wall 2d and equipped with a high strength, so that the fastening force for a cap can be heightened even with a smaller wall thickness of the side circumferential wall 2d. This allows enhancing the sealing performance of the battery and constructing it in a light weight.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a battery can for a dry battery,
The present invention relates to the manufacturing apparatus.

[0002]

2. Description of the Related Art In the manufacturing process of dry batteries, when manufacturing battery cans, a hoop material is punched and press-formed to form a cup-shaped can base material, and the can base material is formed into a cylinder having a smaller diameter and a longer length. Then, the battery can is generally obtained. For example, when manufacturing dry batteries such as AA batteries, a punch made of cemented carbide with a smaller diameter than the can base is advanced to insert its tip into the can of the base of the can, and in the direction of advance of the punch. Insert into the die with the inner diameter gradually decreasing. Then, as the can base material is squeezed and squeezed as the punch advances, when it passes through all the dies,
As shown in FIG. 1, the wall thickness of the side peripheral wall 50a depends on the sealing portion 5
The same battery can 50 including 0b is formed.

When a nickel-cadmium battery is constructed by the battery can 50, the battery can 50 is used.
The rear end portion is cut into a predetermined length, and then, in the battery can 50, though not shown, wound between a positive electrode current collector and a negative electrode current collector via a separator. The prepared positive electrode plate and negative electrode plate are housed and an electrolytic solution is added. At this time, the negative electrode current collector is connected to the bottom surface 50c serving as the negative electrode via the conductive portion, and the positive electrode current collector is connected to the cap serving as the positive electrode via the conductive portion. This cap is firmly sandwiched by the sealing device with respect to the sealing portion 50b of the battery can 50 via an insulating gasket.

As the sealing device, a device provided with a pressure roller is generally adopted, and the pressure roller is gradually moved in the centripetal direction while relatively rotating along the outer periphery of the sealing portion 50b. Then, the edge of the sealing portion 50b is bent inward in the radial direction of the battery can 50, so that the insulating gasket is sandwiched between the peripheral edge of the cap and the edge of the sealing portion 50b. As a result, a nickel-cadmium battery in which the battery can 50 is capped and the inside of the can is sealed is obtained.

[0005]

By the way, in this type of dry battery, it is desired to reduce the thickness of the battery can 50 from the viewpoint of weight saving and material saving. However, the side wall 50a
If the thickness of the sealing portion 50b is too thin, the sealing portion 50b is also thin. Therefore, when the sealing portion 50b is bent by the pressure roller or the like, the sealing portion 50b is firmly attached to the cap to prevent damage. However, there was a problem in that the sealing performance of the battery was insufficient due to the lack of sufficient tightening force.

The present invention aims to solve the above problems.

[0007]

The battery can of the present invention is characterized in that the sealing portion is formed thicker than the other portions of the side peripheral wall.

Further, in the battery can manufacturing apparatus of the present invention, a rod-shaped punch whose tip is inserted into the can of the cup-shaped can base material conveyed to a predetermined position, and the punch are advanced and retracted. A driving means and a plurality of dies each having a gradually smaller inner diameter toward the forward direction of the punch are connected in series, and when the punch is advanced, the can substrate is squeezed to have a diameter smaller than that of the can substrate. In a battery can manufacturing apparatus including a die mechanism for forming a battery can, a rear end portion of the can forming portion of the punch is formed to have a smaller diameter than a front portion thereof, and the rear end portion and the front portion are formed. It is characterized in that the boundary is a tapered surface.

[0009]

When a nickel-cadmium battery is constituted by the battery can having the above-mentioned structure, a positive electrode plate wound between the positive electrode current collector and the negative electrode current collector with a separator interposed therebetween in the battery can, and The negative electrode plate is added with an electrolytic solution and accommodated. Then, a cap is attached to the opening of the battery can. For example, a pressure roller is used to gradually move in the centripetal direction while relatively rotating along the outer periphery of the sealing portion. Then, the edge of the sealing portion is bent inward in the radial direction of the battery can. At this time, since the sealing portion is formed thicker than the other portions of the side peripheral wall and has high strength, even if the side peripheral wall is formed to have a small thickness, the tightening force for the cap is enhanced. ..

Further, in the production of battery cans, when the can base material into which the tips of the punches are inserted is pushed into a plurality of dies having gradually smaller inner diameters in the forward direction of the punches, the cans of the punches are pushed. Since the rear end portion of the forming portion is formed to have a smaller diameter than the front portion thereof, the distance between the outer peripheral surface of the rear end portion and the inner peripheral surface of the die becomes larger than that of other portions. .. Here, when the can base material passes through all the dies, a squeeze (including a narrowly defined squeezing and ironing) is applied to form a battery can. Since the wall thickness increases, the sealing portion of the battery can is formed thicker than the other portions of the side peripheral wall. At this time, since the boundary between the rear end portion and the front portion of the can forming portion of the punch is a tapered surface, metal deformation is smoothly performed when the can base material is squeezed, and the thin wall portion of the side peripheral wall is formed. The stress generated between the thick portion and the thick portion can be reduced, and a battery can having no weak point in strength can be manufactured. Further, when the battery can is detached from the punch, the thick portion of the side peripheral wall is smoothly detached from the punch by being guided by the tapered surface.

[0011]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a vertical sectional view of a battery can according to an embodiment of the present invention. The battery can 2 is cylindrical and has a sealing portion 2e thicker than other portions of the side peripheral wall 2d, and an outer peripheral surface 2b and an inner peripheral surface 2c are formed smooth.
For example, the wall thickness of the sealing portion 2e is 0.2 mm, the wall thickness of the other portion of the side peripheral wall 2d is 0.1 mm, and the wall thickness of the bottom wall 2f is 0.2 mm.
It can be mm.

FIG. 2 is a vertical sectional view showing an apparatus for manufacturing a battery can according to an embodiment of the present invention. This battery can manufacturing equipment is
Can base material 1 formed by punching out hoop material to form a cup
Is molded into a long battery can 2 having a smaller diameter than
It is provided with a can base material conveying section 3, a punch 4, a punch driving section 5, a die mechanism 6, a claw expansion / contraction means 7, a plurality of claws 8 and the like.

The can base material carrying section 3 is constructed by vertically mounting a fixed plate 3a on a support base 9 and fixing a guide rail 3b to the fixed plate 3a. The guide rail 3b has its upper end continuously provided to the can base material forming section via a transport rail (not shown), while its lower end faces the can base material placing section 10 formed in the center of the support base 9. There is. The can base material transporting section 3 is provided with a feeding mechanism (not shown), and the can base material 1 formed by punching out the hoop material in the can base material molding section and having a cup shape is placed from the guide rail 3b onto the can base material. The sheets are sequentially conveyed to the section 10. The can base material mounting portion 10 has a space equivalent to the outer diameter of the can base material 1, and mounts the opening 1a of the transferred can base material 1 toward the slide guide 11 side. The slide guide 11 is a slide bearing for the punch 4, and is fitted to a support base 9 and a guide receiving plate 12 fixed to the support base 9.

As shown in FIG. 4, the punch 4 comprises a punch tool 4a made of a super hard material on the tip side and a support rod 4b for supporting the punch tool 4a, and a rear end of the support rod 4b has a movable portion which will be described later. It is connected to 5a. In the punch 4, the rear portion side 4e of the can forming portion 4c of the punch tool 4a is formed to have a smaller diameter than the front portion 4d, and the boundary between the rear portion 4e and the front portion 4d is a tapered surface 4f. A female screw 4g is formed on the rear side 4e of the punch tool 4a. The female screw 4g is attached to a screw shaft (not shown) provided at the tip of the support rod 4b.

The punch driving section 5 moves the punch 4 forward or backward and has a movable section 5a driven by a cylinder. Then, the can forming portion 4c of the punch 4 is inserted into the can of the can substrate 1 and pushed into the die mechanism 6 when the movable part 5a is advanced, while the punch protruding forward from the die mechanism 6 after the battery can 2 is molded. 4 is set to retreat.

The die mechanism 6 is a squeezing and squeezing can base material 1 and is an outer cylinder 1 fixed on a base 13.
It is installed in No. 4. In the hollow portion 14a of the outer cylinder 14, five die receiving bases 15 to 19 are continuously provided in the length direction, and the inner diameters of the die receiving bases 15 to 19 are gradually increased in the forward direction of the punch 4. The dies 20 to 24 each having a small size are fixed. In this example, the first die 20
Inner diameter of 14.5mm and the inner diameter of the fifth die 24 is 1
The inner diameter of each of the second to fourth dies 21 to 23 is set to 4 mm, and the inner diameters are set to be successively smaller. The can substrate 1 has an outer diameter of 22 mm and a length of 18 mm, and the can substrate 1 is squeezed by the first die 20 when the punch 4 is advanced, and the second to fifth dies 21 to 24 are formed.
By squeezing, the battery can 2 having an outer diameter of 14 mm and a length of about 60 mm is formed.

The pawl expanding / contracting means 7 actuates a plurality of pawls 8 and comprises a click ring 25, a compression spring 32, a ball 36, a click ring swinging means and the like. The click ring 25 is provided on the front end side 14b of the outer cylinder 14 as shown in FIG.
The base ring 27 is joined to the base ring 27. The base ring 27 has a screw hole on the outer circumference and is fixed to the outer cylinder 14 by a fixing screw, and has a small gap between the inner peripheral surface 28 a of the inner cylindrical portion 28 and the outer peripheral surface 4 c of the punch 4. Is caused. Then, the base ring 27 has a claw 8
And a groove 30 communicating with the hollow hole 29 for accommodating the click ring 25.
Are formed. A lid 31 is attached to the front end of the base ring 27, which is the front opening of the hollow hole 29. As shown in FIG. 5, this lid 31 penetrates 8 corresponding to the claw 8 from the outer peripheral surface 31a toward the inner peripheral surface 31b.
The individual through holes 31c are provided. These through holes 3
A compression spring 32 is inserted in 1c, and the compression spring 32
A set screw 33 for locking one end of the spring so that the spring coefficient can be adjusted is screwed. The lid 31 is fitted to the front end of the base ring 27 as shown in FIG. 3 and attached with a fixing screw.

The claws 8 separate the battery can 2 from the punch 4, and as shown in FIGS. 3 and 6, eight claws 8 are arranged on the front end peripheral edge 6a of the die mechanism 6. Each nail 8
As shown in FIG. 3, a concave portion 8c is formed on the outer peripheral surface on the front end side, and an outer peripheral surface on the rear end side 8b is a contact surface 8d.
A protrusion 8e is provided on the inner peripheral surface of the approximate center. This protrusion 8
e comes into contact with the outer peripheral surface 28b of the inner cylindrical portion 28, and the projection 8e
The claw 8 is rotatable about the fulcrum. The other end of the compression spring 32 is locked in the concave portion 8c of the claw 8 and is biased by the compression spring 32 in the centripetal direction. The rear end side 8b of the claw 8 is in contact with the elastic member 34 fitted in the recess 29a of the hollow hole 29, and absorbs an impact applied when the battery can 2 is separated from the punch 4. ,
The nail 8 is protected.

Click ring 25 of the pawl expansion / contraction means 7
As shown in FIG. 6, is circular and is provided with a screw hole 25a in the centering direction in the outer peripheral portion, and the screw portion 35a of the cam lever 35 is screwed into this screw hole 25a. The cam lever 35 is provided in the guide groove 1 formed in the outer cylinder 14.
4d is rotatable and has a guide hole 3 at the upper end.
5b (see FIG. 2). Click ring 2
An inclined cam surface 25b that is divided into eight equal parts is formed on the inner peripheral portion of 5, and the balls 36 are respectively housed between them and the respective pawls 8. The inclined cam surface 25b has a gradually increasing inner diameter in the clockwise direction, with a maximum inner diameter portion being a concave portion 25c and a minimum inner diameter portion being a convex portion 25d. When the cam lever 35 is at the solid line position in FIG.
Is moving toward the ball 36, the front end 8a of the pawl 8 is spring-biased in the centripetal direction by the compression spring 32 to keep the pawl 8 in a contracted state (states shown in FIGS. 3 and 5). ). on the other hand,
The cam lever 35 moves to the position shown by the chain line in the figure, the click ring 25 rotates clockwise, and the convex portion 25d moves to the ball 3 side.
In the state of moving to the 6 side, the contact surface 8d of the claw 8 is pressed to rotate about the projection 8e as a fulcrum, and the front end 8a of the claw 8 retreats in the centrifugal direction to resist the compression spring 32. Each nail 8
Expands in the centrifugal direction.

The motor 26 constituting the click ring swinging means is arranged above the outer cylinder 14 and has a shaft to which a rotary plate 26a is connected. This rotating plate 26a
An eccentric position pin 26b is provided so as to project in the guide hole 35b of the cam lever 35.
When the motor 26 is driven to rotate, the cam lever 35 is swung by being guided by the eccentric position pin 26b, and the click ring 25 is swung within a predetermined range. The motor 26 is synchronized with the cylinder of the punch drive unit 5, and when the cylinder moves the punch 4 forward so that the can forming unit 4c of the punch 4 passes the pawl 8 in the forward direction, it is eccentric. The click ring 25 is swung via the position pin 26b and the cam lever 35 to retract the plurality of pawls 8 in the centrifugal direction, and the inner peripheral surface 8f of the pawl 8 and the outer peripheral surface 2b of the battery can 2 are separated as shown in FIG. A gap is created between them. Further, when the punch 4 moves backward and the can forming portion 4c passes through the claw 8 in the backward direction, the click ring 25 is swung in the reverse direction and the plurality of claws 8 are moved.
Is moved in the centripetal direction so that the front end surface 8g of the claw 8 is engaged with the rear end surface 2a of the battery can 2.

Next, the manufacturing process of the battery can will be described.

First, the can base material 1 formed into a cup shape by punching out the hoop material in the can base material forming part is sequentially conveyed from the guide rail 3b to the can base material mounting part 10.

Then, as shown in FIGS. 2 and 7, the opening 1a of the can substrate 1 is placed with the slide guide 11 side facing. Next, the 4 movable parts 5 of the punch driving part 5
When a is driven by a cylinder, the can forming portion 4c of the punch 4 is inserted into the can of the can base material 1 and pushed into the die mechanism 6 when moving forward. Then, when the punch 4 passes through the first die 20, the can base material 1 is squeezed, and the outer diameter of the can base material 1 becomes small as shown in FIG. 7. Subsequently, when the punch 4 advances, the can substrate 1 is squeezed by the second to fifth dies 21 to 24. Therefore, when passing through all the dies 20 to 24, as shown in FIG. 1, the battery can 2 having a smaller diameter and a longer length than the can base material 1 is formed.

At this time, the motor 26 is rotationally driven in conjunction with the cylinder, but when the cam lever 35 moves from the chain line position in FIG. 8 to the solid line position, the click ring 25 rotates clockwise as indicated by the arrow. In motion, the ball 36 presses the contact surface 8d of the claw 8 to expand the plurality of claws 8,
As shown in FIG. 9, the inner peripheral surface 8f of the claw 8 and the outer peripheral surface 2b of the battery can 2
Creates a gap between and. For this reason, the can forming portion 4 of the punch 4 can be formed without the claws 8 slidingly contacting the outer peripheral surface 2b of the battery can 2.
c and the battery can 2 pass through the claw 8. Therefore, the outer peripheral surface 2b of the battery can 2 is not scratched.

When the can forming portion 4c of the punch 4 passes the claw 8 portion, the battery can 2 is moved to the die mechanism 6 as shown in FIG.
The front end peripheral edge 6a of the outer cylinder 14, that is, the front end portion 14b of the outer cylinder 14 is projected, and the punch 4 retreats. At this time, the cam lever 35 is guided by the guide of the eccentric position pin 26b.
Moves from the chain line position in FIG. 6 to the solid line position, the click ring 25 swings counterclockwise, and the compression spring 32 causes the pawl 8 to move.
The front end portion 8a of the above is spring-biased in the centripetal direction to bring the plurality of claws 8 into a contracted state. Then, the claws 8 are formed on the outer peripheral surface 4c of the punch 4.
The inner peripheral surface 8f of the battery is in sliding contact with the rear end surface 2 of the battery can 2.
Since the front end surface 8g of the claw 8 is engaged with a, the battery can 2 is detached from the punch 4. At this time, the rear end portion 8b of the claw 8 abuts on the elastic member 34 fitted in the recess 29a of the hollow hole 29, so that the impact applied when the battery can 2 is detached from the punch 4 is absorbed. The nail 8 is protected.

As described above, according to the battery can manufacturing apparatus, as shown in FIG. 1, the sealing portion 2e has the side peripheral wall 2d.
The battery can 2 having a larger wall thickness than the other portions is formed. That is,
When the can substrate 1 having the can forming portion 4c of the punch 4 inserted therein is pushed into the plurality of dies 20 to 24, the rear end portion 4e of the can forming portion 4c of the punch 4 has a front portion 4d.
Since the diameter is smaller, the distance between the outer peripheral surface of the rear end portion 4e and the inner peripheral surfaces of the dies 20 to 24 is larger than that of the other portions. Therefore, the can substrate 1 is the die 20.
When the can substrate 1 is squeezed and squeezed through .about.
Therefore, the sealing portion 2e is formed thicker than other portions of the side peripheral wall 2d. At this time, since the boundary between the rear end portion 4e and the front portion 4d is the tapered surface 4f, when the can substrate 1 is squeezed, this squeezing is smoothly performed. In this example, the outer diameter of the battery can 2 is 80.0 mm,
When the side peripheral wall 2d has a wall thickness of 0.1 mm, the wall thickness of the sealing portion 2e is doubled to about 0.2 mm. The bottom wall 2f of the battery can 2 has a wall thickness similar to that of the sealing portion 2e.

Thus, when a nickel-cadmium battery is constructed by the battery can 2, the end of the sealing portion 2e of the battery can 2 is cut as shown by the chain line in FIG. Keep it. Then, as shown in FIG. 10, the positive electrode plate 42 and the negative electrode plate 43 wound between the positive electrode current collector 44 and the negative electrode current collector 45 via the separator 41 are housed in the battery can 2, and the electrolytic solution is stored. Add At this time, the negative electrode current collector 4
5 is connected to the bottom wall 2f serving as a negative electrode via the conductive portion 47, and the positive electrode current collector 44 is connected to a cap 49 serving as a positive electrode via the conductive portion 46. The cap 49 is firmly clamped to the sealing portion 2e of the battery can 2, but here, the cap 49 is firmly clamped to the sealing portion 2e of the battery can 2 with an insulating gasket 48 by a sealing device (not shown). To be done.

That is, the pressure roller of the sealing device is gradually moved in the centripetal direction while relatively rotating along the outer periphery of the sealing portion 2e. Then, the edge of the sealing portion 2e is bent inward in the radial direction of the battery can 2, so that the insulating gasket 48 is sandwiched between the peripheral edge of the cap 49 and the edge of the sealing portion 2e. This allows the battery can 2 to have a cap 49.
Thus, a nickel-cadmium type dry battery in which the inside of the can is sealed can be obtained.

In the above embodiment, the case where the battery can is applied to the nickel-cadmium battery has been described, but it goes without saying that the present invention can be widely applied to alkaline-manganese batteries and other batteries.

[0031]

As described above, according to the battery can of the present invention, since the sealing portion is formed thicker than the other portions of the side peripheral wall, the strength of the sealing portion can be increased. It is possible to increase the tightening force with respect to the sealing cap while reducing the thickness and reducing the material by thinning the other portion of the side peripheral wall.

Further, according to the battery can manufacturing apparatus of the present invention, the rear end portion of the can forming portion of the punch is formed to have a smaller diameter than the front portion thereof, and the boundary between the rear end portion and the front portion is formed. A battery can that can be easily removed from the punch while increasing the tightening force for the sealing cap and without having weak points on strength simply by making a simple structural improvement such as making the taper surface. Can be manufactured.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a battery can according to an embodiment of the present invention.

FIG. 2 is a vertical cross-sectional view of a battery can manufacturing apparatus according to the present invention.

FIG. 3 is an enlarged cross-sectional view of a main part of FIG.

FIG. 4 is a vertical sectional view of a punch.

5 is a cross-sectional view of the pawl expanding / contracting means taken along the line AA in FIG.

6 is a cross-sectional view of the pawl expanding / contracting means taken along the line BB in FIG.

FIG. 7 is an operation explanatory view showing a formation state of a battery can.

FIG. 8 is an operation explanatory view of the pawl expansion / contraction means.

FIG. 9 is an operation explanatory view showing a retracted state of a claw.

FIG. 10 is a vertical cross-sectional view of a dry battery to which the battery can of the present invention is applied.

FIG. 11 is a vertical cross-sectional view of a conventional battery can.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Can base material 2 Battery can 2e Sealing part 2d Side peripheral wall 4 Punch 4a Tip part 5 Driving means 6 Dice mechanism 7 Claw expansion / contraction means 8 Claws 20-24 Dice

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[Procedure amendment]

[Submission date] October 2, 1992

[Procedure Amendment 1]

[Document name to be corrected] Drawing

[Name of item to be corrected] Fig. 11

[Correction method] Change

[Correction content]

FIG. 11

Claims (2)

[Claims] 1. A battery can, wherein the sealing portion is formed thicker than the other portions of the side peripheral wall. 2. A rod-shaped punch, the tip of which is inserted into a can of a cup-shaped can substrate that has been conveyed to a predetermined position,
A driving means for moving the punch forward and backward and a plurality of dies each having a gradually smaller inner diameter in the forward direction of the punch are continuously provided, and the can base is squeezed when the punch is moved forward from the can base. In a battery can manufacturing apparatus provided with a die mechanism for forming a long battery can with a small diameter, a rear end portion of the can forming portion of the punch is formed to have a smaller diameter than a front portion thereof, and the rear end portion is formed. An apparatus for manufacturing a battery can, characterized in that a boundary with the front portion is a tapered surface.