JP2010036262A - Thin plate punching die - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To continuously perform punching by always keeping constant accuracy and clearance in cutting blade parts of a punch and die in a thin plate punching die, and to perform cutting by maintaining the accuracy, even when the temperature of the die chages while using the punching die. <P>SOLUTION: The punch and die are positioned by positioning guide and positioning hole provided integrally with the punch and die. Since the positioning guide is forcibly fitted into the positioning hole, positional accuracy of the die and punch can be exactly performed and can be continued. Even if the temperature of the die rises, the positional accuracy can be maintained. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

The present invention relates to a die for punching, in which a thin sheet as an object to be cut (work) is punched out by a die and a punch.

FIG. 5 shows a method for punching a plate-like material which is generally performed with a die having a die and a punch, and will be described based on this. A thin sheet W, which is a workpiece to be cut, is sandwiched between the die 2 and the stripper 10, and a punch 1 tip having a slightly smaller contour shape than the edge shape of the die 2 is pushed into the die sheet W to be cut in the die 2 and the punch 1. This is a method of cutting W as an object to be cut by shearing with a blade portion. The clearance between the die 2 and the punch 1 is represented by C.

  The die 2 and the punch 1 are respectively fixed by holders (not shown), and the mutual positional accuracy is maintained to some extent. However, the positional accuracy is not sufficient from the viewpoint of the rigidity of the mold body and thermal expansion. If the positional accuracy of the punch 1 and the die 2 is not maintained, it is necessary to provide a large clearance C between the punch 1 and the die 2, or the quality of the edge of the punched material W is deteriorated due to entrainment or peeling. It is easy to cause a bad effect that only a part of the wear and tear is lost.

  For this purpose, a guide post 40 shown in FIG. 6 is generally used so that the punch and die can be positioned more accurately. This is composed of a post 41 for maintaining the positional relationship between the die 2 and the punch 1 and a post guide 42 for receiving the post. The accuracy when this post guide 40 is used is improved as compared with the case where it is not used. This is because by providing this in the vicinity of the punch 1 and the die 2, the influence of the deformed portion is limited between the post-die and the post-punch. For this reason, a form in which the post 41 and the post guide 42 are used for maintaining mold accuracy is often used.

  However, since the distance between the post-die and post-punch still remains, it can be maintained with a clearance of about 2 to 5 μm. However, the clearance is less than 2 μm or less, and the zero-clearance or minus is less than that. The clearance was not accurate enough.

  In Patent Document 1, a guide portion (described as a guide heel) integrated with a punch is provided so as to be integrated with a die and on one die side so as to be fitted with a punch integrated with the guide portion. With this structure, the position accuracy of the punch and the die is further improved as compared with the example using the guide post. However, although the structure is written in the specification, the main purpose is to prevent the wear of the punch and die cutting edge, and it is written that the guide heel is provided. No details are mentioned, including its accuracy.

JP-A-10-235436

In a punching die for punching a thin plate, the problem was that the punch and the cutting blade portion of the die always maintained constant accuracy and clearance, and could be punched continuously. Moreover, even when there was a change in the temperature of the mold during use, it was an object to cut the mold while maintaining its accuracy.

The present invention achieves at least one of the following effects.
1. The relative positional accuracy between the punch and die used for the punching process can be maintained extremely high, and the positional relationship does not change even if it is repeatedly cut.
2. Since positioning is not performed at the portion corresponding to the cutting edge portion between the punch and the die, the punch and die are not easily damaged or worn.
3. The quality of the material to be punched W is high, and chipping, cracking, chipping and the like in the vicinity of the punched portion are particularly suppressed.
4). Even if the mold temperature changes during use, punching can be performed without reducing accuracy.

The punching die of the present invention can be obtained as follows.
First, a mold body such as a frame, a transfer machine, and the like may be manufactured in the same manner as a normal punching mold.
As shown in FIG. 1, the die 2 and the punch 1, which are main parts, are formed integrally with the punch in a positioning guide 5 that fits into the positioning hole 6 of the die 2 prior to the punch 1, and on the die 2 side A positioning hole 6 is provided together with the die 2. This is a schematic diagram in which the positioning guide 5 is provided on the punch 1 side, but the same effect can be obtained by providing the positioning hole 6 on the punch 1 side and the positioning guide 5 on the die 2 side. In the following explanation, the die side is fixed and the punch side approaches the die, but the same result can be obtained regardless of whether the die side or the punch side moves or both.

  As the punch 1 and the die 2 approach each other, the positioning guide portion and the positioning hole contact and fit before the cutting blade portions 13 and 23 of the punch 1 and the die 2 approach each other to position the punch and the die. Do. At this time, if the clearance between the positioning guide portion 5 and the positioning hole portion 6 is large, it is not preferable because there is room for the positional relationship between the punch 1 and the die 2 to be greatly shifted accordingly. In order to ensure the positional relationship between the punch and the die, the clearance between the positioning guide portion 5 and the positioning hole portion 6 must be 0 (μm), or the positioning guide portion should be a “minus clearance” that is larger than the positioning hole portion. There is. By ensuring this, the positional relationship between the punch 1 and the die 2 formed integrally with them can be satisfactorily cut and maintained without deviation.

In order to set the clearance to 0 or minus, it is necessary to fit the positioning guide 5 into the positioning hole 6 in a press-fitted state. If the press-fitting margin is too large, the guide or the like may be broken during fitting. Therefore, the clearance is suitably set to -3 μm or more and 0 μm or less. Since this positioning is performed in advance for each punching, the positional relationship between the punch 1 and the die 2 is always constant, and good cutting can be continued.
The clearance between the positioning guide 5 and the positioning hole 6 is preferably smaller than the clearance between the punch 1 and the die 2. When direct positioning is performed with the punch 1 and the die 2, cutting cannot be performed at a fixed position every time punching is performed, and the punch 1 and the die 2 may be damaged depending on the amount of deviation. If the clearance between the punch 1 and the die 2 is reduced, this breakage is likely to occur, and the wear and tear are accelerated due to strong sliding and friction between each other. Positioning is performed with the positioning guide 5, and the clearance between the punch 1 and the die 2 is set wider than that, and a method of avoiding breakage and wear is desirable for good cutting.

According to a third aspect of the present invention, a taper portion or a chamfered portion provided for facilitating press-fitting is provided on at least one of the distal end portion and the positioning hole edge of the positioning guide. It is a punching device described in 1. By fitting an angle to either the positioning guide 5 or the positioning hole 6, both can be easily fitted. Further, even when there is a positioning error of about several μm in the entire mold, the position is corrected along the taper or chamfering, so that the positioning error generated in other parts in the mold can be canceled out. Without these tapers and chamfers, if there is a positioning error, they may collide with each other from the edge during positioning and cause damage. Therefore, it is more preferable to provide taper and chamfering in both the positioning guide and the positioning hole.

  According to a fourth aspect of the present invention, in the tapered portion or chamfered portion of the positioning guide and the positioning hole edge, the first opposing positioning hole or the tip portion that contacts the positioning guide is at least a positioning guide and a positioning hole. The contour is small by 3 μm or more with respect to the straight portion which is not the chamfered portion. As shown in FIG. 2, at the tapered portion 51 or chamfered portion 30 at the edge of the positioning guide 5 and the positioning hole 6, the first facing positioning hole or the tip portion 51 that comes into contact with the positioning guide is at least the positioning guide and the positioning hole. 4. The punching device according to claim 3, wherein a contour of the straight portion 52 not tapered or chamfered is small by 3 μm or more. In FIG. 2, only the punch and the positioning guide are shown as being integrated, but the punch and the positioning hole may be integrated. (1) is a schematic diagram in which the positioning guide is chamfered, and (2) is a schematic diagram in which the taper processing is performed. The fact that the contour is smaller than 3 μm as described above corresponds to the fact that the value of (b−a) is larger than 3 μm in FIG. In order for the positioning guide 5 and the positioning hole 6 to avoid the destruction, it is preferable that the leading ends of the positioning guide 5 and the positioning hole 6 be provided with an introduction portion of 3 μm or more in the surface direction of the thin plate. If it is smaller than 3 μm, there is a risk that the positioning guide 5 and the positioning hole 6 directly collide vertically beyond the tapered portion due to a subtle error in the other part of the mold. On the other hand, there is no particular limitation on increasing the size, and it may be 2 to 3 mm.

According to a fifth aspect of the present invention, the positioning guide 5 and the positioning hole 6 are made of a material whose thermal expansion coefficient at the operating temperature is larger or equivalent to that of the material in which the positioning guide material 5 forms the positioning hole 6. The punching die according to any one of claims 1 to 4, wherein the punching die can be maintained in a press-fitted state even when the temperature of the die rises during continuous punching. “Equivalent” in this case is used in the sense that the difference in thermal expansion coefficient between the two is 0 to 0.1 × 10 ⁻⁶ (K ⁻¹ ). In the present invention described in claim 6, the positioning guide 5 and the positioning hole 6 are made of different materials, and the thermal expansion coefficient of the positioning guide 5 is in the range of ⁰ to 3.0 × 10 ⁻⁶ (K ⁻¹ ). The punching die according to claim 5, wherein the punching die is larger than a material of the fixed hole. The positioning guide 5 and the positioning hole 6 are basically made of the same material, but there are cases where the materials of both are changed due to material compatibility problems such as wear and chipping. In that case, it is preferable to form the positioning guide 5 side with a material having a higher thermal expansion coefficient.
Since the punching die generates friction during punching, the temperature tends to rise if the outside air temperature is constant. Further, the punching die of the present invention also generates friction due to the positioning guide and the positioning hole, so that the temperature is likely to rise.
If the thermal expansion coefficient on the positioning guide 5 side is large or equivalent as in the present invention, a strong pressure for press-fitting and fitting will be required even if the temperature rises. Does not occur. However, if the difference becomes too large, it is not desirable because it is difficult to press-fit the two parts. In addition, a desirable range of difference is a range of 0 to 3.0 × 10 ⁻⁶ (K ⁻¹ ). By being larger than 0 × 10 ⁻⁶ (K ⁻¹ ), the clearance will not be positive with respect to the temperature rise, and by making the difference not more than 3.0 × 10 ⁻⁶ (K ⁻¹ ) Even if the temperature rises, the clearance does not become extremely negative, and positioning can be performed without hindering press-fitting and fitting.
Contrary to the above, if the positioning hole 6 side becomes extremely large, if the temperature rise is large, a positive clearance larger than 0 μm may occur between them. Positioning becomes difficult.

The present invention according to claim 7 is a cemented carbide comprising a punch, a die, and positioning guides and positioning holes provided integrally therewith, wherein the metal bonding component is 0.5 to 30% by mass and the balance is carbide. , Zirconia ceramics containing 50% or more of partially stabilized zirconia as a main component, alumina-carbide ceramics in which the proportion of carbide is 10 to 40% by mass and the balance is alumina and a sintering aid, and silicon nitride is 70 as a main component The punching die according to any one of claims 1 to 6, comprising at least one of silicon nitride ceramics and tool steel containing at least mass%. Tool steel is generally used for punches and dies, and cemented carbide is used when wear is severe. High-speed steel and die steel, which are tool steels, are advantageous in that they are inexpensive and easy to process, and cemented carbide has high wear resistance and is also used for long-lasting cutting edge performance. It is often difficult to use ceramics for dies, punches, positioning guides and positioning holes from the standpoint of toughness. Among them, zirconia ceramics and carbides containing 50% or more of partially stabilized zirconia with relatively high fracture toughness values. Alumina-carbide ceramics with a proportion of 10 to 40% by mass and the balance consisting of alumina and a sintering aid, silicon nitride ceramics containing 70% by mass or more of silicon nitride as a main component, withstand use and obtain a long life. be able to.

In the present invention according to claim 8, at least one mold main body for fixing the die or the punch is provided with a mechanism capable of expanding and contracting between the mold main body and the holder of the die or the punch. The die or punch according to any one of claims 1 to 7, further comprising a die or a punch that is movable at 30 µm or less and is movable in the surface direction of the thin sheet of the thin plate following the positioning guide and the positioning hole. It is a punching die. In the third aspect, a method for adjusting the positioning by applying a taper or chamfering to the positioning guide or the like is described. According to the eighth aspect of the present invention, a mechanism capable of expanding and contracting between the die body and the die or punch holder is provided so as to correspond thereto, and the mechanism is movable by 30 μm or less with respect to the surface direction of the thin sheet. . FIG. 3 shows an example using rubber. In this example, the die holder is movable with respect to the mold body in the surface direction of the thin sheet by the elasticity of the rubber. By providing this, the mold body moves in accordance with the positioning guide and the positioning hole, and the positional relationship between the positioning guide, the punch, and the die is always constant, so that cutting with high accuracy can be realized. In order to realize this, as described in claim 9, a mechanism in which the mold body can move freely by 30 μm or less in the surface direction of the thin sheet is provided between the holder supporting the die or punch and the mold body. A mechanism for expanding and contracting such as resin, mild steel, pure copper, a spring, a hydraulic cylinder, a damper, and an XY slider may be provided between the mold body and the die holder. By providing this, as shown in FIG. 3, it is possible to easily align the die side and the punch side accurately with reference to the positioning guide and the positioning hole.

The present invention according to claim 10 is an electrode in which a strip-shaped thin sheet to be punched includes a metal compound having a thickness of 10 to 200 μm on one or both sides of a current collector made of a metal foil having a thickness of 10 μm to 200 μm. The punching die according to any one of claims 1 to 9, wherein the punching die is a power storage device electrode coated with a material or carbon. The present invention described in claim 1 and after is particularly suitable for a thin plate having a thickness of about several μm to 500 μm, but does not particularly specify a material that can be punched, and has the same thickness as a general mold. Metal, resin, rubber, paper, etc. up to several mm can be cut well.

Examples of the electricity storage device include a battery, a capacitor, a capacitor, and the like. Currently, it is difficult to cut various thin sheets well, but it is an electrode of a lithium ion battery. Generally, this electrode has a lithium compound active material containing an organic binder or carbon applied as an electrode material on one or both surfaces of a metal foil such as copper or aluminum. When cutting this electrode, the metal foil that is difficult to cut and stretches easily and the electrode material that is relatively brittle and easy to peel off, so the cutting edge of the die and punch must be sharp and the clearance must be reduced to some extent. It is difficult to cut continuously, suppressing the occurrence of stretch and burrs. In addition, the cutout dimensions are required to have high accuracy. The punching die according to the present invention is suitable for cutting the electrodes because the die and the cutting edge of the punch have a sharp state and the dimensional accuracy is high.
Hereinafter, the present invention will be described in more detail by way of examples.

  Below, several main examples of the present invention will be described.

Example 1
As shown in FIG. 1, the present invention was used in a punching die that has a cutting edge portion on the long sides 13 and 23 of the punch 1 and the die 2 and cuts the thin sheet W into a strip shape.
A substantially hexagonal positioning guide 5 that is integral with the punch 1 having the cutting edge portion 13 and whose tip protrudes from the cutting edge portion is provided.
On the die side, a positioning hole 6 corresponding to the shape of the positioning guide formed integrally with the cutting edge portion 23 was provided.
The punch and die were made of cemented carbide with the same material and a composition of WC-10 mass% Co.
The cutting blade portions 13 and 23 cut the thin plate W by two straight lines.
Regarding the cutting edge portions 13 and 23 of the punch 1 and the die 2, the die side was made 3 μm larger than the punch side. In other words, the clearance between the two is plus 3 μm (one side 1.5 μm).

On the other hand, in the positioning guide 5 and the positioning hole 6, the positioning guide 5 is made 1 μm larger than the shape of the positioning hole 6, and the clearance between both is set to −1 μm.
A chamfered portion 20 having an angle of 10 ° was provided around the guide from the tip of the positioning guide. As a result, the outer shape of the tip portion was smaller by 10 μm than the other straight line portion (see FIG. 2).

The thin plate W was continuously cut with the punching die whose main part was described above. The material of the thin plate W is an electrode for a lithium ion battery, which is one of power storage devices in which a hard but relatively brittle lithium compound is mixed with an organic binder and applied to 80 μm on both sides of a 10 μm thick copper foil. It was.
Moreover, the test environment was a constant temperature room (22 degreeC), and it tested in the state which can maintain temperature constant, performing an air blow to a metal mold | die part.

The punching process is as follows.
1. 1. The thin plate W is transported onto the die while the punch 1 and the die 2 are separated. A stripper (not shown) (10 in FIG. 5) presses and fixes the thin plate W onto the surface of the die 2 from both sides of the punch 1. 2. Punch 1 and positioning guide 5 descend in the direction of die 2 3. The positioning guide 5 with the chamfered portion 20 attached from the tip descends along the positioning hole 6. 4. The positioning guide 5 and the positioning hole 6 are completely in close contact with each other at the upper end of the chamfered portion, and thereafter, the outer shape of the positioning guide 5 becomes larger, so press-fitting into the positioning hole 6 begins. 5. The position of the cutting edge portion of the punch 1 and the die 2 is determined by the positioning guide 5 and the positioning hole 6 in the press-fitted state. The punch 1 having a clearance of 1.5 μm on one side and the cutting edge portions 13 and 23 of the die 2 are brought into contact with the thin plate and punched as it is.
7). A strip-shaped thin plate punched below the die hole 2 falls. 7. The punch 1 stops at a position 1 mm below the upper surface of the die 2 and then moves up. 8. Stripper not shown rises. The press-fitted positioning guide 5 comes out of the positioning hole 6 (returns to 1).

This 1. ~ 9. By repeating this process, the thin plate was continuously subjected to a punching test. As a result, the following things were confirmed.

A. The cutting of the thin plate was smoothly performed up to 100,000 shots at the end of the test without causing burrs and causing problems such as shape collapse and peeling of the coating material.
B. When the punch 1 and the die 2 were brought close to each other without sandwiching a thin plate at the end of 100,000 shots, the clearance was 1.5 μm on one side, unchanged from that before operation.
C. The cutting edges 13 and 23 of the punch 1 and the die 2 had normal wear of about 2 μm from the edge. The edge shape was almost maintained and there was no chipping or chipping.
D. The tapered portion of the positioning guide 5 was not damaged. Further, the positioning guide 5 and the positioning hole 6 did not change in dimensions even after press-fitting 100,000 times.
E. The punch 1, die 2, positioning guide 5 and positioning hole 6 that were 20 ° C. immediately after the start of the test had almost no temperature change at the end of the test.

(Example 2)
The other conditions are the same as in Example 1, and the material of the punch 1 and the positioning guide 5 is alumina-30 mass% titanium carbide ceramic (thermal expansion coefficient 7.8 × 10 ⁻⁶ (K ⁻¹ )), the die 2 and The material of the positioning hole 6 was tungsten carbide-10 mass% cobalt cemented carbide (thermal expansion coefficient 5.8 × 10 ⁻⁶ (K ⁻¹ )).
At a room temperature of 20 ° C., the clearance between the die and the punch was 3 μm, and the clearance between the positioning guide and the positioning hole was 0 μm.

  When a test similar to that of Example 1 was performed in a room where temperature control was not performed, the die 1, punch 2, positioning guide 5, and positioning hole 6 were found to be punched at 30 ° C. in about 30 minutes after use. The temperature reached 50 ° C., and then remained almost unchanged.

  One hour after the start of the experiment, the clearance between the die 1 and the punch 2 narrowed to about 2.5 μm, and the clearance between the positioning guide 5 and the positioning hole 6 became about −0.5 μm, but the test was continued as it was. Neither the cemented carbide nor the ceramics were damaged or chipped.

As a result of the experiment, 100,000 shots could be performed satisfactorily without any problem as in Example 1. The amount of wear of the cutting edges 13 and 23 of the punch 1 and the die 2 was 1 μm for a punch using ceramics and about 2 μm for a die using a cemented carbide. There were no abnormalities such as burrs or chips on the thin plate, and there was no variation in quality, and punching was possible.

(Example 3)
As shown in FIG. 4, a die holder 8 is in contact with the die side through hard rubber 7 provided at four locations. Although not shown, the die holder 8 cannot be moved in the thickness direction of the thin plate but is held so as to be movable only in the direction of the thin plate surface.
On the punch side, a positioning guide integrated with the punch 1 and having a taper of 3 ° was used.

Using this die set, the punch 1 and the positioning guide 5 were deliberately moved down by 10 μm from the position where they were completely fitted, and the die side was positioned from where the positioning hole 6 hit the tapered portion of the positioning guide. It moved following the guide, and at the end of the taper, the punch and die, the positioning guide and the positioning hole overlapped accurately with an accuracy of 1 μm or less.

Schematic diagram of punching die provided with positioning guide and positioning hole of the present invention integrally with a punch and a die Two-sided view showing the measurement method of the linear part and tip part of the positioning guide Schematic diagram of the method of adjusting the position of the positioning guide and positioning hole by using a taper Die set in which die and positioning hole are movable only in the surface direction of W by using hard rubber Schematic diagram of a general punching die Example of using a guide post with a general punching die

Explanation of symbols

1 Punch 2 Die 5 Positioning Guide 6 Positioning Hole 7 Hard Rubber 8 Die Holder 9 Mold Body 10 Stripper 13 Cutting Edge (Punch Side)
23 Cutting edge (die side)
30 Chamfered portion 40 Guide post 41 Post 42 Post guide 51 Tapered portion 52 Straight portion 53 Guide post W Strip-shaped thin sheet C which is a punched material Clearance

Claims (10)

A die for punching and punching products from a strip-shaped sheet with a die and punch cutting edge.
Has a protruding positioning guide that is integral with the die or punch on either the die or punch,
The other has a positioning hole that fits with the positioning guide,
The positioning guide and the positioning hole have a function of fitting before the cutting blade portion cuts during the punching operation to align the position of the die and the punch,
The positioning guide and the positioning hole are set to zero clearance or minus clearance in which the contour shape of the positioning guide is set larger than 0 μm to 3 μm,
A punching die characterized in that a positioning guide is press-fitted into a positioning hole and punching is performed with a cutting edge after positioning. The punching die according to claim 1, wherein the clearance between the positioning guide and the positioning hole is set smaller than the clearance between the punch and the cutting edge portion of the die. At least one of the tip of the positioning guide and the positioning hole edge,
The punching device according to claim 1 or 2, wherein a taper portion or a chamfered portion provided for facilitating press-fitting is provided. In the tapered portion or chamfered portion of the positioning guide and the edge of the positioning hole, the tip portion that first contacts the positioning hole or positioning guide is 3 μm at least with respect to the straight portion that is not the tapered portion or chamfered portion in the positioning guide and positioning hole. The punching device according to claim 3, wherein the contour is small. The material of the positioning guide and positioning hole,
The material of the positioning guide has a larger or equivalent thermal expansion coefficient in the operating temperature range than the material that forms the positioning hole.
The punching die according to any one of claims 1 to 4, wherein the positioning can be maintained in a press-fitted state even when the temperature of the die rises during continuous punching. 6. The positioning guide and the positioning hole are different in material, and the thermal expansion coefficient of the positioning guide is in the range of ⁰ to 3.0 × 10 ⁻⁶ (K ⁻¹ ), which is larger than the positioning hole material. The punching die described in 1. The punch, die, and positioning guide and positioning hole provided integrally therewith are made of cemented carbide made of carbide with a metal bonding component of 0.5 to 30% by mass and the balance of 50, partially stabilized zirconia as the main component. % Of zirconia-based ceramics containing 10% by mass or more, alumina-carbide-based ceramics comprising 10-40% by mass of the carbide and the balance being alumina and a sintering aid, silicon nitride-based ceramics containing 70% by mass or more of silicon nitride as a main component, tool The punching die according to any one of claims 1 to 6, comprising at least one of steel. At least one mold body for fixing the die or punch is movable by 30 μm or less in the surface direction of the thin sheet by providing a mechanism capable of expanding and contracting between the mold body and the die or punch holder. The punching die according to any one of claims 1 to 7, further comprising a die or a punch that is movable in the surface direction of the thin sheet of the thin plate in accordance with the positioning by the hole. A mechanism that allows the mold body to move freely in the surface direction of the thin sheet 30 μm or less is between the holder supporting the punch or die and the mold body, rubber, resin, mild steel, pure copper, spring, hydraulic cylinder, damper, XY slider The punching die according to claim 8, wherein any one of the above is provided. An electricity storage device in which a strip-shaped thin sheet to be punched is coated with an electrode material or carbon containing a metal compound with a thickness of 10 to 200 μm on one or both sides of a current collector made of a metal foil with a thickness of 10 μm to 200 μm. The punching die according to any one of claims 1 to 9, wherein the punching die is a working electrode.

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