JPH10202596A - Metal mold and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To attain repairing which requires only replacing a divided piece and metal mold cost reduction by forming a plurality of divided pieces formed with groove parts at their jointed parts, out of adjacent divided pieces jointed to each other and formed side by side. SOLUTION: This device is constituted of divided pieces 1, 2 which are made of metal such as cemented carbide and divided into a plurality of pieces, and a square type frame body 3 made of metal such as cemented carbide. The divided piece 1 involves a plurality of groove parts 1e, and inclined end surfaces 1f at both end parts of it. The divided piece 2 positioned between divided pieces 1 involves a plurality of grooved parts 2e formed vertically at a surface to be the joining part 2d of its both side parts, and inclined end surfaces 2f at both end parts of it. The divided pieces 1, 2 are fitted by being pressured in the square type frame body 3 in such a condition as their joining parts 1d, 2d and 2d, 2d are joined to each other and formed side by side, so that a lower metal mold K is formed. In this metal mold K, the groove parts 1e, 2e of adjacent divided pieces 1, 2 become in such a condition as to face each other, so as to form punch fitting holes.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a die suitable for use in a device having fine punch holes, for example, in the manufacture of a chip resistor or the like for an electric component, and a method of manufacturing the die.

[0002]

2. Description of the Related Art Prior to describing a conventional mold, a structure of a chip resistor as an electric component and a method of manufacturing the chip resistor will be described with reference to FIGS. First, generally, as shown in FIG. 16, a chip resistor 50 is provided with a plurality of cutouts 52 on both sides of a ceramic substrate 51 to form protrusions 53 serving as terminals. . A resistor 54 is provided on the entire upper surface of the substrate 51, and a terminal 55 made of silver or the like is provided on the protrusion 53, thereby forming a chip resistor 50.

The chip resistor 50 is used for forming an electric circuit by soldering the terminal 55 to a circuit wiring board (not shown). Further, in recent years, there has been a demand for integration of electric circuits, and there has been a strong demand for miniaturization. For this reason, for example, in FIG.
The dimensions of the width B of the protrusion, the width C of the cut portion, and the length D of the cut portion are 1, 6: 0, 8: 0, 24: 0, 1
8, but the size is further reduced.

A method of manufacturing the above-described chip resistor will be described. First, as shown in FIG. 17, a soft ceramic plate portion 60 called a green sheet is prepared. In the meantime, a hole 61 for forming the cutout 52 of the chip resistor 50 is formed by punching using a die. Next, the hole 61
After sintering the plate-shaped portion 60 provided with the slab to form the hard plate-shaped portion 60, as shown in FIG. 18, a resistor 54 is formed on the entire surface of the plate by coating or the like. Next, as shown in FIG. 18, silver is applied along the holes 61 arranged in parallel to form terminals 55.

After that, as shown in FIG. 18, the plate-shaped portion 60 is divided at a horizontal line E connecting the centers of the holes 61, and then the plate-shaped portion 60 is divided at a vertical line F, as shown in FIG. Hundreds of chip resistors 50 are manufactured at a time.
That is, as shown in FIG. 19, the center of the hole 61 and the adjacent substrate 51 are cut by the division between the horizontal line E and the vertical line F, and the chip resistors 50 which are individually separated are manufactured. .

A conventional die used for forming a hole in a plate-like portion in the process of manufacturing such a chip resistor will be described with reference to FIGS. 12 is a sectional view of a main part of a conventional punching device, FIG. 13 is a plan view showing a part of a conventional lower die, and FIG. 14 is an explanatory view showing a conventional die manufacturing method. Is a partial cross-sectional view of a lower mold in a manufacturing process, FIG. 15B is a plan view of a part thereof, FIG. 15 is an explanatory view showing a conventional method of manufacturing a mold, and FIG. FIG. 3B is a partial cross-sectional view of a mold, and FIG.

The configuration of a conventional mold is shown in FIG.
2. As shown in FIG. 13, a lower mold 30 composed of a single rectangular block made of metal has a mouth-shaped base 31 provided around the lower part thereof and a lower part excluding the base 31. The punching escape portion 32 is provided, and a plurality of punch fitting holes 34 penetrating the escape portion 32 from above in the upper surface plate 33 where the escape portion 32 is located. This punch fitting hole 34
Has a rectangular shape, and is for forming a hole 61 of the plate-shaped portion 60. The die 30 has thousands of holes 34 for punch fitting.

Further, the metal mounting base 35 has a concave portion 36 and a hole 37, and the mold 30 is placed in the concave portion 36.
The mold 30 is attached. On the movable table 38 located above the mold 30, thousands of punches 39 are fixed corresponding to the punch fitting holes 34, and the punch fitting holes 3 are fixed.
4 can be inserted and removed. Further, a stopper plate 40 movable together with the movable base 38 is provided between the movable base 38 and the mold 30, and the punch 39 penetrates the stopper plate 40 and faces the mold 30. I have.

[0009] In forming the hole 61 of the plate-shaped portion 60, first, the soft plate-shaped portion 60 is placed on the upper surface of the mold 30. Next, the movable table 38 and the stopper plate 40 are moved downward, the punch 39 is pierced into the plate-shaped portion 60, and the stopper plate 40 is brought into contact with the plate-shaped portion 60, and the movable table 38 is further moved. It moves downward to fit the punch 39 into the punch fitting hole 34 of the mold 30. Then, a hole 61 is punched and formed in the plate-shaped portion 60, and a cutout portion generated when the hole is punched falls through the escape portion 32 and the hole 37. Next, the movable table 38 and the stopper plate 40 are moved upward, the punch 39 is pulled out from the fitting hole 34, and after returning to the initial state, the plate-shaped portion 60 is taken out from the mold 30, and a punching process is performed. Is completed.

Next, a method of manufacturing the mold 30 will be described with reference to FIG.
4. Referring to FIG. 15, first, FIG.
As shown in FIG.
A single metal block 41 is formed. Next, FIG.
As shown in FIG. 4A, the wire 42 of the electric discharge machine is moved up and down, and a circular hole 43 is formed one by one in the upper plate 33 of the metal block 41 by electric discharge machining using the tip of the wire 42. The hole 43 is a rectangular punch fitting hole 3.
The hole 43 is formed in a portion corresponding to the center portion of the hole 4, and as shown in FIG. Next, the metal block 41 in which the hole 43 has been drilled.
As shown in FIG. 15 (A), this is attached to another electric discharge machine, and a wire 44 for electric discharge machining is inserted into the hole 43 and set. The wire 44 is a rectangular mold corresponding to the hole 34 for punch fitting. Move along the contour of the wire 44 and perform electric discharge machining on the side of the wire 44 to form one desired punch fitting hole 34. Next, this wire 44 is inserted into another hole 43 to form the punch fitting holes 34 in the same manner as described above. In this manner, the punch fitting holes 34 are individually formed, as shown in FIG. The hole 30 is formed, and the mold 30 is manufactured.

The smallest wire currently used on the market for electric discharge machining has a diameter of 0 or 15 mm and cannot be used for drilling holes smaller than this.
The chip resistors are increasingly required to be miniaturized, and the conventional mold 30 has become unable to cope with them.

[0012]

In the conventional mold 30, a large number of punch fitting holes 34 are provided in a single rectangular metal block. The mold 30 will produce a bad chip resistor, and this mold 30 will be replaced with a new one. However, since the mold 30 is extremely expensive, there is a problem that the manufacturing cost of the mold 30 and the chip resistor increases. In addition, the manufacture of the mold 30 requires two processes, one for forming a hole 43 and one for forming a hole 34 by an electric discharge machine. In addition, since each machining process is an electric discharge machining, it takes several days for the machining. However, there is a problem that the productivity is low and the cost is high. In addition, since it is an electric discharge machining, a hole having a diameter of 0 or 15 mm or less cannot be formed, and there is a problem that it is impossible to cope with a smaller size.

[0013]

As a first means for solving the above-mentioned problems, there is provided a plurality of metal divided pieces provided with a joining portion on a side portion, and a combination of adjacent divided pieces is provided. The plurality of divided pieces are arranged side by side so that the parts are joined to each other, and at least one of the adjacent divided pieces is provided with a groove portion located at the mating portion, and the groove portion has a punch fitting hole. . Further, as a second solving means, opposing grooves located at the mating portion are provided in both of the adjacent divided pieces, and a punch fitting hole is formed in the groove. As a third solution, the plurality of divided pieces are arranged side by side in a metal mouth frame. As a fourth solution, the frame body and the divided piece are configured to have the same height. Further, as a fifth solution, an inclined surface is provided on the inner surface of the side plate facing the frame so that the opening gradually increases from the upper end to the lower end, and the divided piece corresponding to the inclined surface is provided. Are provided with inclined end surfaces at both ends thereof, and the inclined end surfaces are brought into contact with the inclined surfaces of the side plates. As a sixth solution, a stepped portion is provided on the inner surface of the side plate facing the frame, and a stepped portion is provided at both ends of the divided piece. The step portion of the side plate and the step portion of the split piece were configured to contact each other. As a seventh solution, the split piece includes an upper surface plate portion, and a leg portion provided integrally with the upper surface plate portion in a longitudinal direction at a lower center in a short direction of the upper surface plate portion, The longitudinal side portion of the upper plate portion was used as a mating portion, and the lower cutout portion was formed as a relief hole for punching. As an eighth solution, a side wall extending downward from the mating portion of the upper surface plate portion is provided at a position other than the groove provided in the divided piece, and the side walls of adjacent divided pieces are joined to each other. The configuration was adopted.

[0014] As a ninth solution, a groove is formed by grinding at a portion which becomes a joining portion of the side portions of the plurality of divided pieces, and the joining portions of adjacent divided pieces are joined to each other. As described above, a method for manufacturing a mold having a plurality of divided pieces is provided. Further, as a tenth solution, there is provided a mold manufacturing method in which a groove is formed by grinding in a portion to be a joining portion of an adjacent divided piece, and the adjacent divided pieces are joined so that the groove faces each other. did. Further, as an eleventh solution, the width of the groove is reduced to 0, 1 by grinding.
A method for manufacturing a mold for performing machining of 5-0, 07 mm was adopted. Further, as a twelfth solution, there is provided a method for manufacturing a metal mold, wherein a plurality of divided pieces are housed in a metal die frame.

[0015]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a die according to an embodiment of the present invention; FIG. Sectional view, FIG. 2
3 is a plan view of the mold of the present invention, FIG. 3 is a partial cross-sectional view taken along line YY of FIG. 2, FIG. 4 is a cross-sectional view taken along line ZZ of FIG. 2, and FIG. FIG. 6 is an explanatory view of a divided piece according to the mold of the present invention, and FIG. 7 is a perspective view of a part of the divided piece according to the mold of the present invention.

As shown in FIGS. 1 to 7, the structure of the mold K in the present invention is divided into a plurality of divided pieces 1 and 2 made of a metal such as a cemented carbide, and And a mouth-shaped frame 3 made of metal. In particular, as shown in FIG. 5, the split pieces 1 located on both sides are aligned with a leg 1c formed by providing a longitudinal cutout 1b at the lower portion of the upper surface plate 1a and a side portion. A plurality of groove portions 1 provided in a vertical line from the upper portion to the notch portion 1b at intervals along the mating portion 1d at a portion to be a portion 1d.
e, and an inclined end face 1f that becomes wider at both ends from the upper surface plate 1a to the leg 1c.

Further, a split piece 2 located between the split pieces 1
The notch 2b provided on both sides of the lower part of the upper surface plate 2a in the longitudinal direction, and the notch 2b allows the upper surface plate 1a to extend in the longitudinal direction at the lower center in the short direction of the upper surface plate 1a.
a, and a mating portion 2 on both sides.
d, at intervals along the mating portion 2d,
A plurality of grooves 2e provided in a vertical stripe from the upper part to the notch 2b, and the upper end plate 2a and the leg 2
c, which has an inclined end face 2f that becomes wider as going to c.

The mouth-shaped frame 3 has side plates 3a, 3b,
3c, 3d, an opening 3e provided in the side plate, and an inclined surface 3 provided on the inner surfaces of the opposing side plates 3a and 3c such that the opening 3e gradually increases from the upper end to the lower end.
f. The split piece 1 is housed in the opening 3e of the frame 3 with its side portions abutting against the side plates 3b and 3d and its inclined end surface 1f abutting against the side plates 3a and 3c, respectively. ing. Further, the plurality of divided pieces 2 are positioned between the divided pieces 1 in the opening 3e of the frame 3, and the inclined end faces 2f thereof are
c, and the adjacent mating portions 2d are joined to each other, and the mating portion 2d of the split piece 1 and the adjacent split piece 2 is housed in a state of being joined to the mating portion 1d of the split piece 1.

That is, the divided pieces 1 and 2 are joined to each other at the joint 1d.
And 2d, and 2d and 2d are joined together and juxtaposed, and are press-fitted and attached to the frame 3 to form a lower mold K. Then, the mold K assembled in this way is, as shown in FIG.
The grooves 1e and 2e are opposed to each other to form a punch fitting hole 4, and as shown in FIG. 3, a notch 1 provided at a lower portion of the adjacent divided pieces 1 and 2.
b and 2b face each other to form a punching relief hole 5. Further, when assembled, the divided pieces 1 and 2 are accommodated in the frame 3 at the same height as the frame 3.

As shown in FIG. 1, the metal mounting base 6 has a concave portion 6a and a hole 6b, and the lower end portion of the frame 3 and the leg portions of the divided pieces 1, 2 are provided in the concave portion 6a. The mold K is mounted with the lower ends of 1c and 2c supported. Also,
The movable table 7 located above the mold K has the grooves 1e,
Thousands of punches 8 are fixed corresponding to the punch fitting holes 4 formed in 2e, and can be inserted into and removed from the punch fitting holes 4. Further, a stopper plate 9 movable with the movable base 7 is provided between the movable base 7 and the mold K, and the punch 8 penetrates the stopper plate 9 and faces the mold K. I have.

In forming the holes 61 of the plate-shaped portion 60, first, the soft plate-shaped portion 60 is placed on the upper surface of the mold K. Next, the movable table 7 and the stopper plate 9 are moved downward, the punch 8 is pierced into the plate-shaped portion 60, and the stopper plate 9 is brought into contact with the plate-shaped portion 60. It moves downward to fit the punch 8 into the punch fitting hole 4 of the mold K. Then, the hole 61 is formed in the plate-shaped portion 60.
Is formed by punching, and a cut-out portion generated when punching is dropped downward through the punching escape portion 5 and the hole 6b. Next, the movable base 7 and the stopper plate 9 are moved upward, the punch 8 is pulled out from the punch fitting hole 4 and returned to the initial state. After the plate-shaped portion 60 is taken out from the mold K, the hole is opened. Processing is complete.

Next, a method of manufacturing the mold K according to the present invention will be described. First, a metal piece divided into a plurality of pieces constituting one mold K and a frame of a mouth mold as shown in FIG. Make 3. Next, notches 1b and 2b as shown in FIG. 5 are formed in these metal pieces, and inclined end faces 1f and 2f are formed at both ends. Then, the metal piece is set in a grinding machine, and the surfaces to be the joining portions 1d and 2d are subjected to grinding with a grindstone to form desired groove portions 1e and 2e. Make 1 and 2. Next, such divided pieces 1 and 2 are combined with each other at the mating portions 1d and
A plurality of molds K are completed by arranging a plurality of them side by side so as to join 2d and pressing them into the frame 3. In the mold K thus manufactured, the punch fitting hole 4 is formed by the grooves 1e and 2e, and the punching escape portion 5 is formed by the notches 1b and 2b.

The width C of the groove 2e in FIG. 7 corresponds to the width C of the notch in FIG. 16, and since the groove 2e is formed by grinding with a grindstone, the width C is reduced in this grinding. Processing up to about 0,07 mm is possible. Therefore, it is possible to form a fine hole for punch fitting which cannot be realized by electric discharge machining, and the machining time can be shortened to about 1/3 as compared with electric discharge machining.

FIGS. 8 to 11 show another embodiment of the mold according to the present invention. Here, the same portions as those of the above embodiment are denoted by the same reference numerals, and the detailed description is omitted. FIG. 8 shows another embodiment of the split pieces 1 and 2 of the mold K of the present invention. The split piece 2 shown in FIG. 1 to FIG. It was done. In this case, in the joining unit 2d,
There is a groove 2e formed and a groove not formed, but at least one mating portion 2d has a groove 2e. FIG. 9 shows another embodiment of the split pieces 1 and 2 of the mold K of the present invention. In this embodiment, only one of the mating portions 1d and 2d of the split pieces 1 and 2 has the groove 1e and the groove 1e.
2e is formed so that the adjacent divided pieces 1 and 2 and the mating portions 1d and 2d of 2 and 2 are joined to each other to form the punch fitting hole 4.

FIG. 10 shows another embodiment of the divided pieces 1 and 2 of the mold K according to the present invention.
A relatively wide area between the grooves 2e provided in the upper surface plate 2a.
And a side wall 2g extending downward from the mating portion 2d. Although not shown here, it goes without saying that a side wall may be formed in the divided piece 1 in the same manner.
When the divided pieces 1 and 2 are joined to each other to join the joints 1d and 2d, the side walls are joined to each other, and the support of the divided pieces 1 and 2 arranged side by side is strengthened.

FIG. 11 shows another embodiment of the mold K of the present invention, in which stepped portions 1h and 2h having upper cutouts are provided at both ends of the divided pieces 1 and 2, and a frame 3 is provided. Side plates 3a, 3c
Is provided with a stepped portion 3g with a cutout at the bottom, and the stepped portions 1h and 2h of the divided pieces 1 and 2 are brought into contact with the stepped portion 3g of the frame 3 to attach the divided pieces 1 and 2 to the frame 3 It was done. Also,
Although not shown here, an elliptical, circular, or triangular punch fitting hole can be formed by variously changing the shape of the grooves 1e, 2e. Further, such a mold is naturally applicable not only to the manufacture of a chip resistor but also to an electric razor or the like.

[0027]

The mold according to the present invention comprises a plurality of divided pieces provided with grooves at the mating portions and arranged side by side by joining adjacent divided pieces. Even if one of the grooves serving as the fitting holes is broken, the repair can be performed simply by replacing the divided piece, and the repair is simple, and the die cost is low. Also, on both of the adjacent divided pieces,
Since the punch fitting holes are formed by forming the opposing grooves, the length of each groove can be reduced, and the workability and productivity are improved. Also, since the split piece was attached to the mouth frame, a mold can be formed simply by inserting the split piece into the frame,
Its fabrication is simple. Also, by making the frame and the split pieces the same height, when this is attached to the mounting base,
The support can be ensured, and the mold can be stably supported during the punching operation. In addition, since an inclined surface is provided on the side plate of the frame, and the inclined end surface of the divided piece is brought into contact with the inclined surface, the work of inserting the divided piece into the opening of the frame is facilitated, and the assemblability is improved. . In addition, since the step of the divided piece is brought into contact with the step of the frame, the divided piece does not come out of the frame, and its attachment can be surely performed. In addition, by providing the legs on the split pieces, the support of the split pieces on the mounting base can be ensured, and by providing the notches on the split pieces,
The cut-out portion can be used as a punching escape hole, and the punched-out portion can be smoothly discharged.
Further, when the adjacent divided pieces are joined, by providing the side walls to be joined to each other, it is possible to reliably support the divided pieces arranged in parallel. Further, since the groove of the divided piece is manufactured by grinding, the workability is good, the manufacturing time of the mold can be significantly reduced, and an inexpensive mold can be provided. Also,
Since the grooves formed by grinding are arranged opposite to each other on both of the adjacent divided pieces, the length of each groove can be reduced, the grinding can be facilitated, and the workability can be improved. Also, the width of the groove by grinding is set to 0, 15-0, 0
By setting the diameter to 7 mm, it becomes possible to machine a fine punch hole that cannot be machined by electric discharge machining. Furthermore, by inserting the divided pieces into the frame of the mouth mold, a mold having good assemblability can be provided.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part of a punching device according to the present invention.

FIG. 2 is a plan view of a mold according to the present invention.

FIG. 3 is a partial cross-sectional view taken along line YY of FIG. 2;

FIG. 4 is a sectional view taken along line ZZ in FIG. 2;

FIG. 5 is an exploded perspective view of the mold of the present invention.

FIG. 6 is an explanatory view of a divided piece according to the mold of the present invention.

FIG. 7 is a perspective view of a part of a divided piece according to the mold of the present invention.

FIG. 8 is a plan view showing another embodiment of the divided piece according to the mold of the present invention.

FIG. 9 is a plan view showing another embodiment of the divided piece according to the mold of the present invention.

FIG. 10 is a partial perspective view showing another embodiment of the divided piece according to the mold of the present invention.

FIG. 11 is a sectional view of a main part showing another embodiment of the mold of the present invention.

FIG. 12 is a sectional view of a main part of a conventional punching device.

FIG. 13 is a plan view of a conventional mold.

FIG. 14 is an explanatory diagram for explaining a conventional method for manufacturing a mold.

FIG. 15 is an explanatory diagram for explaining a conventional method for manufacturing a mold.

FIG. 16 is a plan view of a chip resistor manufactured by a mold.

FIG. 17 is a plan view showing the method for manufacturing the chip resistor.

FIG. 18 is a plan view showing the method for manufacturing the chip resistor.

FIG. 19 is an explanatory view showing the method of manufacturing the chip resistor.

[Explanation of Signs] K Mold 1, 2 Split piece 1a, 2a Top plate 1b, 2b Cutout 1c, 2c Leg 1d, 2d Fitting 1e, 2e Groove 1f, 2f Inclined end face 2g Side wall 2h Step 3 Frame 3a Side plate 3b Side plate 3c Side plate 3d Side plate 3e Opening 3f Inclined surface 3g Step 4 Punch fitting hole 5 Relief hole for punching 6 Mounting stand 6a Depression 6b Hole 7 Movable table 8 Punch 9 Stopper plate

Claims (12)

[Claims] 1. A method according to claim 1, further comprising: a plurality of metal split pieces provided with a joining portion on a side portion, wherein the plurality of split pieces are juxtaposed so that joining portions of the adjacent split pieces are joined to each other; A mold, characterized in that at least one of the adjacent divided pieces is provided with a groove positioned at a mating portion, and the groove forms a punch fitting hole. 2. The die according to claim 1, wherein opposing grooves located at the mating portion are provided on both of the adjacent divided pieces, and the grooves form punch fitting holes. 3. The mold according to claim 1, wherein the plurality of divided pieces are arranged in a frame of a metal die. 4. The mold according to claim 3, wherein the frame and the divided pieces are formed at the same height. 5. An inner surface of an opposing side plate of the frame body is provided with an inclined surface such that an opening gradually increases from an upper end to a lower end, and at both ends of the divided piece corresponding to the inclined surface. The mold according to claim 3, wherein an inclined end surface is provided, and the inclined end surface is brought into contact with the inclined surface of the side plate. 6. A stepped portion which is notched downward is provided on an inner surface of a side plate facing the frame body, and a stepped portion which is notched upward is provided at both ends of the divided piece. The mold according to claim 3, wherein the portion and the step portion of the divided piece are brought into contact with each other. 7. The split piece includes an upper surface plate portion, and a leg portion provided at a lower central portion in a short direction of the upper surface plate portion and provided integrally with the upper surface plate portion in a longitudinal direction. 7. The method according to claim 1, wherein the longitudinal side portion is a mating portion, and the lower cutout portion is a punch-out relief hole. Mold. 8. A side wall extending downward from a mating portion of the upper surface plate portion is provided at a position other than the groove provided in the divided piece, and the side walls of adjacent divided pieces are joined to each other. The mold according to claim 7, wherein the mold is formed. 9. A plurality of divided pieces are formed by forming a groove by grinding in a portion which is to be a joining portion of the side portions of the plurality of divided pieces so that the joining portions of adjacent divided pieces are joined to each other. A method for manufacturing a mold, comprising: 10. The method according to claim 9, wherein a groove is formed by a grinding process at a place where the adjacent divided pieces are to be joined, and the adjacent divided pieces are joined so that the grooves face each other. Mold manufacturing method. 11. The width of the groove is set to 0 by grinding.
11. The method for manufacturing a mold according to claim 9, wherein machining of 15-0, 07 mm is performed. 12. The method for manufacturing a metal mold according to claim 9, wherein a plurality of divided pieces are housed in a metal die frame.