JPS5842765B2 - Punching method for soft metal with adhesive properties - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a punching method for punching a sticky soft metal, such as lithium used as a negative electrode active material for batteries, into a predetermined shape such as a disc shape with good workability.

Lithium is an excellent material for use as a negative electrode active material for batteries because of its high electronegativity. However, its material properties include being sticky, flexible, and easily deformed, making it difficult to cut as expected, and containing moisture in the air. There is instability in that it easily reacts with

Therefore, for example, when lithium is used as the negative electrode active material of a coin-shaped battery, a coiled lithium sheet is punched out into a disk shape of a predetermined size in a dry atmosphere.

FIG. 3 shows a conventional lithium punching method.

In this figure, 1 is an eccentric press, 2 is a lithium sheet which is a material to be eroded which is unwound from a coiled state, 3 is an upper punch for punching, and 4 is a lower die.

The upper punch 3 and the lower die 4 are usually made of hard synthetic resin because if they are made of metal, lithium will stick to them when punching lithium, making it impossible to cut them into a desired shape.

Reference numeral 5 denotes a movable plate that supports a battery case 6 that moves in and out directly under the punching part of the lower die 4. As shown in FIG. It is attached to the inner bottom of the bag.

The lithium sheet 2 is intermittently fed in one direction as shown by arrow A, and stops at a predetermined position of the lower die 4.

The stopped lithium sheet 2 is punched out into a disk shape by the lower die 4 having a circular die hole as the upper die punch 3 descends, and the lithium sheet 2 is punched out into a disk shape by the lower die 4 having a circular die hole while remaining attached to the tip of the punch 3. It is properly attached to the inner bottom of a battery case 6 supported by a movable plate 5 prepared in advance directly below.

When punching out such a disk-shaped coin-shaped lithium 2' from the lithium sheet 2, in order to achieve high precision punching dimensions, the dimensional accuracy of the resin upper punch and lower die must be made high. There is a need.

However, it is difficult to process and prepare, and because it has poor strength compared to metal molds, it easily wears out, and has short mold lifespans, requiring frequent replacement of molds.

Furthermore, since the Senryo type is made of synthetic resin, the degree of lithium adhesion is lower than that of metal types, but this does not mean that the adhesion has disappeared, so when it is attached to the inner bottom of the battery case after punching, it is shaped like a coin. The lithium cover may be incomplete or deformed, and it is not satisfactory to punch out a coin-shaped lithium piece with good workability and attach it to the inner bottom of the battery case without deforming it. Ta.

The present invention solves the drawbacks of the conventional punching methods, and provides a punching method that can punch out coin-shaped lithium from a lithium sheet with good workability, and can also reliably cover the inner bottom of the battery case. It provides:

Hereinafter, an embodiment of the present invention will be described in which a lithium negative electrode of a coin-type battery is punched out and placed inside a battery case.

Figure 1 is a perspective view of the main parts of the device used in the present invention.
2 is a press unit; 2 is a lithium sheet that is unwound from a coiled state and is supplied; 7 is a feeding roller that places this lithium sheet on a curved surface and transports it, and also serves as a lower mold for the press; 8
9 is a punching part, 9 is a case indexing plate driven by Geneva, and a plate-shaped battery case 11 is supplied from a shooter 10.
This is for holding the coin-shaped lithium 2' in the recess 12 of the same edge and transferring it to the side of the punching part 13, and placing the punched coin-shaped lithium 2' on the inner bottom of the case.

Reference numeral 14 denotes a discharge portion of the case, and 15 denotes an upper press plate of the press portion, which holds the punch portion 8 vertically and rotatably, and connects the punch portion 8 to the punch portion 13 and the case inner bottom portion 16. We are making it possible to move between.

Next, the specific structure of the punching section 8 and the feed roller 7 will be explained with reference to FIG. 2, along with a method for punching out coin-shaped lithium from a lithium sheet.

The feeding port/rough serves both as a rotary transport body for the lithium sheet 2 and as a presto lower die during punching. A rubber lining or elastic synthetic resin lining 17 is provided, which has a cylindrical cross section curved to the highest point.

On the other hand, the punch part 8 includes a punch 18 in the form of a cylindrical sleeve with a tapered tip 18', a sleeve-like strike IJ collar 19 made of synthetic resin that moves up and down on the outside thereof, and a sleeve-like strike IJ collar 19 made of synthetic resin that moves up and down inside the punch 18. A jacket pin 20 is provided coaxially.

Note that 21 is a spindle with a pin 20 fixed to its lower end.

Punch 18. Sl-, IJ collar 19 and jacket bin 20
The three parties are in mutual positions in the state shown in Figure 2 a! The relationship is maintained and each has its own cushioning mechanism.

The punch part 8 descends toward the lithium sheet 2 which is warped in a cylindrical shape on the fico-shaped rubber lining 17 in the state shown in FIG. It is held down by the force determined by the cushion mechanism.

Then, the cylindrical sleeve-shaped punch 18 descends to remove the lithium inside the stripper until the tapered tip 18' cuts shallowly into the rubber lining 17, as shown in Figure 2, and the lithium sheet 2 is shaped into a coin shape 2'. Push through.

At this time, there is a punch 1 in the lower inner part of the stripper 19.
Relief 19 to make it easier to move in and out the tapered tip of 8.
' is provided.

Further, the rubber lining 17 has an appropriate elastic resistance so that it will not be cut even if the tip of the punch 18 bites in slightly.

The coin-shaped lithium 2' that has been punched out by the punch 18 is attached to the inside of the tip of the punch due to its adhesive properties, and the lithium sheet 2 is pressed down by the punch while the sl-IJ collar 19 is still pressing the lithium sheet 2. 18 retreats upward, resulting in the state shown in FIG. 2C.

After this, the IJ collar 19 also retreats upward, and the punch part 8 as a whole rotates 180 degrees from the punch part 13 to reach the retaining part 16, and is placed above the battery case 11 held in the recess 12 of the index plate 9. The state shown in Fig. 2 (d) is reached.

After this state, the entire punch part 8 descends again, and after fixing the opening edge of the battery case 11 with the stripper 19, the punch 18 descends, and further the spindle 21 descends, and the crimp pin 20 at the tip of the punch part A second button presses the coin-shaped lithium 2' attached to the inside of the case 11 against the inner bottom surface of the case 11 in a square defined by a cushion mechanism.
The process is shown in Figure e.

When pressing the coin-shaped lithium 2' against the inner bottom of the case, the punch 18 acts as a guide, and the positive pressing force of the crimp pin 20 suppresses the coin-shaped lithium 2' from escaping to the surroundings. can be reliably crimped without deformation.

After this, the correct pin 20. Punch 18. The stripper 19 retreats upward in order, rotates 180 degrees again, faces the punching section 13, and begins punching out the lithium sheet 2 into a coin shape.

In this way, the punching method of the present invention uses lithium or a soft metal with similar adhesiveness as a hydraulic punching material, and uses rubber or elastic synthetic resin to serve as a transporting body and press lower die to transport the material. A feed roller with the same surface made of steel, a punch section with a cylindrical punch, a stripper, and a crimping pin movable up and down coaxially are used to press the workpiece to be corroded by the stripper onto the feed roller. After that, the workpiece is punched out with a punch, so the workpiece can be punched out with ease of operation, and the punched member can be properly attached to a receiving case or the like without deforming it.

[Brief explanation of the drawing]

Figure 1 is a perspective view showing the main parts of the punching device used in the present invention, and Figures 2 a, b, c, d, and e show the process of punching a lithium sheet, which is a workpiece, and pressing it onto a receiving case. FIG. 3 is a diagram showing a conventional lithium sheet punching device, and FIG. 4 is a diagram showing press-bonding of punched coin-shaped lithium to a receiving case. 2... Lithium sheet, 2'... Lithium punched into a coin shape, 7... Feed roller, 8... Punch part, 11... ...Receiving case, 17... Tyco-shaped rubber lining,
18... Punch, 18' tapered tip, 19... S) IJ collar 120...
- Correct pin, 21...Spindle.

Claims (1)

[Scope of Claims] 1. A feeding roller with a peripheral surface made of rubber or elastic synthetic resin, which serves as a transporting body and a press lower mold for transporting the sticky soft metal that is the material to be caroeed, and a cylindrical shape. a punch, a mating pin that moves up and down inside the punch, and a stripper that moves up and down outside the punch so as to press the soft metal, which is the material to be cut, against the feed roller; ) After pressing the soft metal onto the feed roller with the IJ collar, the punched patch is lowered and the soft metal is pressed until the tip of the punch partially bites into the circumferential surface of the feed roller, and the soft metal is attached to the inside of the punch. After that, the soft metal attached to the inside of the punch is separated by the downward movement of a pin provided on the punch side, and the soft metal attached to the inside of the punch is attached to the inside of the receiving case. . 2. The method for punching a soft metal with adhesive properties according to claim 1, wherein the feed roller is curved in a cylindrical shape so that the center portion of its circumferential surface is highest. 3. The method for punching a soft metal with adhesive properties according to claim 1, wherein the soft metal with adhesive properties is lithium.