JP7561092B2 - Metal element for slide fastener, and method for manufacturing metal element for slide fastener - Google Patents

Description

The present invention relates to a metal element for a slide fastener and a method for manufacturing the same.

One example of a method for manufacturing a metal element for a slide fastener is known, which includes a press process for forming irregularities, in which a metal plate is plastically deformed in the thickness direction to form the interlocking convex and concave portions of the interlocking head of the metal element, and a punching press process for punching out the metal element to be the product from the metal plate after the press process for forming irregularities (Patent Document 1).

According to the manufacturing method disclosed in Patent Document 1, the hole in the die used in the punching press process is chamfered to a radius of 0.01 to 1.0 mm at its entrance, and the back side is formed parallel to the entrance in the depth direction. The gap between the punch and the die is set to 0.1 to 10 μm.

According to the manufacturing method disclosed in Patent Document 1, sheared surfaces and fractured surfaces are always formed on the left and right legs of the punched metal element. More specifically, the entire outer surfaces of the meshing head and the left and right legs of the metal element are formed by sheared surfaces and fractured surfaces, with the proportion of sheared surfaces to the total area being 80% or more, and the proportion of fractured surfaces to the total area being less than the remaining 20%. And because the surface roughness of the fractured surfaces is higher than that of the sheared surfaces, the appearance of the metal element is improved by increasing the proportion of sheared surfaces to the total area.

Figure 8 shows a metal element equivalent to that disclosed in Patent Document 1. This figure is a copy of an image captured by irradiating the left side surface of the metal element 1a with light obliquely from above to below. In this figure, the outer surface of the left leg 3a and the left side surface of the interlocking head 2a are shown as the left side surface of the metal element 1a. In the image, the side surface of the metal element is formed of dark black and white parts. The dark black parts are shear surfaces, and the white parts are fracture surfaces. In this figure, the dark black parts (shear surfaces 4a) are represented by parallel, evenly spaced thin lines, and the white parts (fracture surfaces 5a) are represented by white (note that this color coding only applies to the side surface of the metal element 1a, and the white color of the parts other than the outer surface of the metal element 1a does not represent the fracture surfaces 5a). As can be seen from this figure, the shear surfaces 4a occupied most of the outer surface of the left leg 3a (excluding the right edge), and the fracture surfaces 5a occupied the remaining small part (right edge) of the outer surface of the left leg 3a.

JP 2005-237532 A

The present invention was created in consideration of the above situation, and its purpose is to further improve the appearance of the outer surface of the metal element.

The metal element for a slide fastener of the present invention comprises an interlocking head and left and right leg portions. The left and right leg portions each comprise left and right leg body portions extending in two directions from the interlocking head portion, and left and right clamping portions extending in directions approaching each other from the tips of the left and right leg body portions. In addition, the left and right leg body portions have a portion on their outer surfaces that has only a shear surface over a certain width range and does not have a fracture surface.

The range of a certain width is, for example, as follows: 1) and 2).
1) The range of a certain width is the range corresponding to the core of the tape that is sandwiched between the left and right leg bodies.
2) The range of a certain width refers to the entire outer surface of the left and right leg bodies.

In addition, the portion having only a shear surface and no fracture surface may be only the outer surface of the leg body or may not be only the outer surface of the leg body.
That is, the outer surface of the engaging head also has a portion that has only a shear surface and does not have a fracture surface.

The manufacturing method of the metal element for slide fastener of the present invention is premised on comprising a press process for forming the unevenness, which plastically deforms the metal plate in the thickness direction to form the interlocking convex portion and interlocking concave portion of the interlocking head of the metal element, and a press process for punching out the metal element to be the product from the metal plate after the press process for forming the unevenness. The press process for punching forms the outer shape of the interlocking head of the metal element, while forming the outer shape of the left and right legs, which include left and right leg bodies extending in two directions from the interlocking head and left and right clamping portions extending in directions approaching each other from the tips of the left and right leg bodies.

In addition, in the manufacturing method of the metal element for a slide fastener of the present invention, the die used in the press processing for punching is characterized in that the entrance of the hole in the die and the area of a certain width of the part corresponding to the outer surface of the left and right leg bodies is an inclined portion with an inclined surface, and the inclined surface is inclined in the direction of the depth of the hole in such a way that the width of the hole narrows toward the back of the hole.

The range of a certain width is, for example, as follows: 3) and 4).
3) The range of a certain width is the range corresponding to the core of the tape that is sandwiched between the left and right leg bodies.
4) The range of a certain width refers to the entire outer surface of the left and right leg bodies.

Moreover, the portion having only a shear surface and no fracture surface may be formed only on the outer surface of the leg body or not.
That is, the die used in the press working for punching is provided with an inclined portion also at the entrance portion of the die hole and at the portion corresponding to the outer surface of the engagement head.

The details of the inclined surface are not important, but it is preferable that it be as follows.
That is, the inclined surface is inclined at an angle θ with respect to the depth direction of the hole so as to satisfy the following relational expression 1, where 0°<θ≦30°.
More preferably, Relation 1 is as follows:
Relational expression 1 satisfies 10°≦θ≦28°.

The metal element for slide fasteners of the present invention does not have fracture surfaces over a certain width on the outer surfaces of the left and right leg bodies, but only has shear surfaces, so the appearance of the metal element is improved compared to metal elements that have fracture surfaces on the outer surfaces.

In addition, the manufacturing method of the metal element for slide fasteners of the present invention forms an inclined portion with an inclined surface at the entrance of the die hole, and the inclined surface is inclined relative to the depth direction of the hole such that the width of the hole narrows toward the back of the hole. Therefore, during the press processing for punching, a certain width range of the outer surfaces of the left and right leg bodies is formed in a state where it is pressed against the inclined surface during the period when it passes through the inclined surface. As a result, only shear surfaces are formed within a certain width range of the outer surfaces of the left and right leg bodies within the thickness range of the metal element without fracture (without the formation of torn marks), and the appearance of the outer surfaces of the left and right leg bodies is improved compared to a manufacturing method using press processing that simply punches out the metal element from a metal plate.

FIG. 1 is a perspective view showing a metal element for a slide fastener according to a first embodiment of the present invention. 1A and 1B are drawings showing the metal element in a comparative manner with the left and right legs in an open and closed state. FIG. 4 is a left side view of the metal element. FIG. 2 is a plan view showing a slide fastener in which a metal element is used. 2 is a plan view showing a method for manufacturing a metal element for a slide fastener according to the first embodiment of the present invention. FIG. 6 is a cross-sectional view taken along line VI-VI of FIG. 5. 7 is a cross-sectional view taken along line VII-VII of FIG. 5. FIG. 1 is a left side view showing an example of a conventional metal element for a slide fastener.

As shown in FIG. 4, the metal elements 1 for the slide fastener are fixed at intervals to the opposing side edges of a pair of tapes 9. As a result, a large number of metal elements 1 are lined up in a row along the longitudinal direction of the opposing side edges of each tape 9. This row of a large number of metal elements 1 is called an element row. By moving a slider (not shown) in one direction along the pair of opposing element rows, the metal elements 1 of the opposing element rows interlock with each other to close the pair of tapes 9, and by moving the slider in the opposite direction, the metal elements 1 of the opposing element rows are released from the interlocking with each other to open the pair of tapes 9.

As shown in Figures 1 and 2, the metal element 1 of the first embodiment of the present invention is composed of an interlocking head 2 that interlocks with another metal element 1, and a pair of legs 3 that are attached in a state in which they sandwich the side edges of the tape 9 and extend in two directions from the interlocking head 2. The metal element 1 is made of, for example, an aluminum alloy.

Here, the directions required for explaining the metallic element 1 are defined as follows, with reference to FIG.
The "left-right direction" refers to the direction in which the pair of legs 3 are separated, and is the left-right direction in Fig. 2. The left-right direction coincides with the thickness direction of the tape 9.
The "upward direction" refers to the direction of the interlocking head 2 relative to the pair of legs 3, and is the upward direction in FIG.
The "downward direction" refers to the direction of the pair of legs 3 relative to the interlocking head 2, and is the downward direction in Fig. 2. The up-down direction coincides with the width direction of the tape 9.
The "front-rear direction" is a direction perpendicular to the left-right direction and the up-down direction, and perpendicular to the plane of the paper in Fig. 2. The "front-rear direction" is also the thickness direction of the metal element 1.

The interlocking head 2 comprises a head body 21 and an interlocking protrusion 22 and an interlocking recess 23 that are relatively uneven on both the front and rear sides of the head body 21. That is, the interlocking head 2 comprises an interlocking protrusion 22 that protrudes on both the front and rear sides of the head body 21 and an interlocking recess 23 that is recessed on both the front and rear sides of the head body 21 (see FIG. 3). Note that, in this embodiment, a metal element 1 having an interlocking protrusion 22 and an interlocking recess 23 on both the front and rear sides of the head body 21 is described, but the present invention can also be applied to a type of metal element having only an interlocking recess on one front or rear side of the head body 21 and only an interlocking protrusion on the other side.

The lower part of the head body 21 is a joint 25 where the left and right legs 3 are joined, and the upper side of the joint 25 is a flat plate portion 26 which extends upward and is recessed in a step shape from both the front and rear sides of the joint 25.
The joint 25 is U-shaped with an opening toward the top on both the front and rear sides. The front and rear sides of the metal element 1 (both sides in the thickness direction of the metal element 1) at the joint 25 and the left and right legs 3 are parallel planes. More specifically, the front surface of the joint 25 and the front surfaces of the left and right legs 3 are flush with each other, that is, they are located on the same plane, and the rear surface of the joint 25 and the rear surfaces of the left and right legs 3 are also flush with each other and are parallel to the front surfaces of the joint 25 and the left and right legs 3.
The central portion of both the front and rear sides of the flat plate portion 26 is a portion from which the interlocking protrusion 22 protrudes. The front and rear sides of the flat plate portion 26 below the interlocking protrusion 22 (on the leg portion 3 side) are recessed in a stepped shape from the interlocking protrusion 22 and the joint portion 25. As a result, an interlocking recess 23 surrounded by the interlocking protrusion 22 and the joint portion 25 is formed on both the front and rear sides of the flat plate portion 26 (head body 21).

The left and right legs 3 each include left and right leg bodies 31 extending in two directions from the interlocking head 2, and left and right clamping portions 32 extending from the tips (lower ends) of the left and right leg bodies 31 in directions approaching each other.
2A shows the state before the metal element 1 is attached to the tape 9. In this state, the left and right leg bodies 31 are formed in such a shape that the left and right distance between them increases as they go downward.
2(B) shows the state in which the metal element 1 is attached to the tape 9. The side edge of the tape 9 facing the other tape 9 (not shown) is formed to be thicker than the opposite side. This thick part is called the core part 9a. On the other hand, the thinner part located adjacent to the core part 9a is called the tape main body part 9b. In other words, the tape 9 comprises the tape main body part 9b and the core part 9a adjacent to one end in the width direction of the tape main body part 9b.
When attached to the tape 9, the left and right leg bodies 31 are formed so that most of their outer surfaces are substantially parallel to the vertical direction, and the core 9a is housed inside. The left and right clamping parts 32 clamp the tape body 9b and support the core 9a so that it does not slip out.
2(B), the metal element 1 has its opposing surfaces in the vertical direction (upper and lower surfaces) approximately parallel to the thickness direction of the tape 9, and its opposing surfaces in the left-right direction (outer surfaces) approximately parallel to the width direction of the tape 9. In addition, the metal element 1 has corners C1 where the upper surface intersects with the left and right outer surfaces as smoothly continuous curved surfaces C1 that bulge in an arc, and corners C2 where the lower surface intersects with the left and right outer surfaces as smoothly continuous curved surfaces C2 that also bulge in an arc.

The above-mentioned metal element 1 has a certain width range (hereinafter referred to as the "full shear surface range") consisting only of the shear surface 4 on the outer surface of the left and right leg main bodies 31. The metal element 1 also has shear surfaces 4 and fracture surfaces 5 on the outer surface other than the full shear surface range. Several examples of providing the full shear surface range on the outer surface of the metal element 1 will be explained below using Figure 2 (B). As a premise, the state in which the metal element 1 is attached to the tape 9, that is, the state in Figure 2 (B), is used as the reference.

In this standard state, a first example of the entire shear surface range of the metal element 1 targets the outer surfaces of the left and right leg bodies 31, and is as follows. In the standard state, the left and right clamping parts 32 of the metal element 1 are formed with a pair of parallel, planar clamping surfaces 32a that clamp the tape body 9b of the tape 9 in its thickness direction. An imaginary line L1 is drawn in the thickness direction of the tape 9 from the end point of the clamping surface 32a closest to the core 9a. This imaginary line L1 is the first boundary line L1 that separates the entire shear surface range of the left and right leg bodies 31 from the remaining parts.

In the reference state shown in FIG. 2(B), an imaginary line L2 is drawn in the thickness direction of the tape 9 from the extreme edge in the width direction of the tape 9 in the space formed between the left and right legs 3. The imaginary line L2 is the second boundary line L2 that separates the entire shear surface range of the left and right leg bodies 31 from the rest of the area.

Therefore, the entire shear surface range of the left leg body 31 is the range S1 located on the left side of the left leg body 31 between the first left boundary line L1 and the second left boundary line L2. Similarly, the entire shear surface range of the right leg body 31 is the range S2 located on the right side of the right leg body 31 between the first right boundary line L1 and the second right boundary line L2. Thus, the first example of the entire shear surface range of the metal element 1 is the range S1, S2 between the first left and right boundary lines L1 and the second left and right boundary lines L2, which is the range S1, S2 corresponding to the core 9a of the tape 9 sandwiched between the left and right leg bodies 31.

2(B), a second example of the entire shear surface range of the metal element 1 is directed to the left and right leg bodies 31 and the joint 25 of the interlocking head 2, as follows. As described above, the front and rear faces of the U-shaped joint 25 that opens upward and the front and rear faces of the left and right legs 3 are formed flush with each other. Then, an imaginary line L3 is drawn in the thickness direction of the tape 9 from the end of each of the front and rear faces of this joint 25 that is farthest from the leg 3. This imaginary line L3 is the third boundary line L3 that separates the entire shear surface range of the metal element 1 from the other parts.
A second example of the entire shear surface range of the metal element 1 is the range S3, S4 between the left and right first boundary line L1 and the left and right third boundary line L3, which is in short a shape that connects the outer surface of the interlocking head 2 and the outer surfaces of the left and right leg bodies 31.

2(B), a third example of the total shear surface range of the metal element 1 targets the entire outer surface of the metal element 1, and is as follows. As described above, the top surface of the metal element 1 is approximately parallel to the thickness direction of the tape 9, and the upper left and right corners C1 are curved surfaces C1 that bulge in an arc shape. An imaginary line L4 is drawn from the uppermost point of this curved surface C1 in the thickness direction of the tape 9. This imaginary line L4 is the upper boundary line L4 that separates the total shear surface range of the metal element 1 from the remaining portion.
As described above, the lower surface of the metal element 1 is approximately parallel to the thickness direction of the tape 9, and the left and right corners C2 on the lower side are curved surfaces C2 that bulge in an arc shape. An imaginary line L0 is drawn from the lowest point of this curved surface C2 in the thickness direction of the tape 9. This imaginary line L0 is the lower limit boundary line L0 that separates the entire shear surface range of the metal element 1 from the other parts.
A third example of the total shear surface range of the metal element 1 is the ranges S5, S6 between the left and right upper boundary line L4 and the left and right lower boundary line L0, which is the entire left and right outer surface S5, S6 of the metal element 1, and more specifically, is a shape that is continuous with the entire outer surface of the left and right leg bodies 31 and the entire left and right outer surface of the coupling head 2. Incidentally, the entire outer surface of the left and right leg bodies 31 is the ranges S7, S8 between the left and right lower boundary line L0 and the second left and right boundary line L2.

The first to third examples of the full shear surface range indicated in the reference state shown in Figure 2 (B) above are examples of providing a full shear surface range, and the full shear surface range only needs to be provided over a certain width range on the outer surface of the leg body 31 at the very least, and over the entire surface in the thickness direction of the metal element 1. It is preferable to provide the full shear surface range over the entire outer surface that is visible to the user of the fastener product (clothing, bag, etc.) when the fastener is attached.

Incidentally, in Figures 1 and 3, the shear plane 4 is represented by parallel, evenly spaced thin lines in the same manner as in Figure 8. Note that Figure 1 shows the entire outer surface of the left and right leg bodies 31 and the entire outer surface of the joint 25 as the entire shear plane range, while Figure 3 shows the entire left and right outer surfaces of the metal element 1 as the entire shear plane range. In addition, the outer surfaces of the left and right leg bodies 31 are formed only by the shear plane 4 that is sheared in the penetrating direction (front-to-back direction) of the space formed between the left and right legs 3.

The surface roughness (arithmetic mean roughness) Ra of the sheared surface 4 is 1.0a or less. The surface roughness (arithmetic mean roughness) Ra of the fractured surface 5 is greater than 1.0a. This value is rounded off to one decimal place for the unit a.

As shown in FIG. 5, the manufacturing method of the metal element 1 for a slide fastener of the first embodiment involves continuously manufacturing the metal element 1 of the first embodiment from the metal plate 7 by intermittently stopping the metal plate 7 at least twice while transporting it and pressing it during each of the two stopping periods. The letters A and B shown in FIG. 5 indicate the positions of each press processing on the transport path. The hatched areas in FIG. 5 are the processing areas in the press processing. The metal plate 7 is strip-shaped, and its thickness corresponds to the thickness of the joints 25 of the left and right legs 3 and the interlocking head 2.

The first press working shown in FIG. 5A uses a die (not shown) to plastically deform the metal plate 7 in its thickness direction to form the interlocking convex portion 22 and interlocking concave portion 23 of the interlocking head 2 of the metal element 1. In other words, the first press working is a press working for forming the concaves and convexes of the interlocking head 2.

The second press working shown in FIG. 5B is a punching press working for punching out the metal element 1 to be the product from the metal plate 7 after the press working for forming the unevenness. More specifically, the second press working punches out the hatched area inside the dashed line in the figure (the inner part of the outer shape of the metal element 1) of the metal plate 7, forming the outer shape of the metal element 1, that is, the outer shapes of the interlocking head 2 and the left and right legs 3, as shown in FIG. 5C. Then, as shown in FIG. 1, the shear surface 4 and the fracture surface 5 are formed on the parts of the outer surface of the left and right leg bodies 31 other than the entire shear surface range, but only the shear surface 4 is formed on the entire shear surface range of the left and right leg bodies 31 without the fracture surface 5 being formed.

Cross-sectional views of the punch 11 and die 12 used in the second press working are shown in Figures 6 and 7 (cross-sectional views taken along lines VI-VI and VII-VII in Figure 5). The punch 11 has a portion that punches (pushes) the metal sheet 7, which is formed with an outer shape that is slightly smaller than the outer shape that corresponds to both the left and right legs 3 and the joint 25 of the interlocking head 2 (the shape of the inner side h2 of the hole h in the die 12, which will be described later). The portion of the die 12 on which the metal sheet 7 is placed is formed with a width that allows the metal sheet 7 to be placed thereon in a sufficiently stable manner.

In this specification, the side of the hole h in the die 12 where the metal element 1 enters during punching is referred to as the entrance portion h1, and the back side of the hole h relative to the entrance portion h1 is referred to as the back side portion h2.

The innermost portion h2 is shaped to correspond to the outer shape of the metal element 1 and has a surface parallel to the depth direction.

The inlet portion h1 is formed with an outer shape slightly larger than the outer shape of the metal element 1. The inlet portion h1 of the hole h has a portion corresponding to the entire shear surface range of the left and right leg main bodies 31 as an "inclined portion having an inclined surface for forming only the shear surface" (hereinafter simply referred to as an inclined portion). The depth of the inclined surface of the inlet portion h1 is, for example, 0.20 to 0.30 mm. This value is rounded off to two decimal places in mm.
On the other hand, the portion of the entrance h1 of the hole h where the inclined portion is not formed is chamfered only to a radius of 0.01 to 1.0 mm (this value is rounded off to two decimal places in mm) as in the manufacturing method disclosed in the conventional technology Patent Document 1, or is chamfered to a radius smaller than that, and a smoothly continuous curved surface is formed in a shape that bulges in an arc by the chamfering. Also, the portion of the entrance h1 of the hole h where the inclined portion is not formed has a surface parallel to the depth direction on the far side of the chamfered curved surface.

In the examples of Figs. 6 and 7, for the sake of convenience and to make the explanation easier to understand, an example is shown in which the entire inclined portion is an inclined surface, but in reality, it is not essential to make the entire surface an inclined surface, and it is desirable to have a curved surface that is smoothly continuous with the inclined surface by chamfering in a shape that bulges in an arc from the inclined surface. For example, almost the entire depth direction of the inlet portion h1 may be an inclined surface, and the corner of the inlet portion h1 with the back side portion h2 may be a curved surface that is smoothly continuous with the inclined surface by bulging in an arc from the inclined surface (for example, a curved surface formed by chamfering with a radius of 0.01 to 1.0 mm (this value is rounded off to the third decimal place in mm)), or the corner of the inlet portion h1 with the upper surface of the die 12 may be a curved surface that is smoothly continuous with the inclined surface by bulging in an arc from the inclined surface.

The inclined surface is inclined linearly as a whole with respect to the depth direction of the hole h. Furthermore, this inclination state is such that the width of the hole h narrows toward the back of the hole h. In other words, the inclined surface is inclined with respect to the depth direction of the hole h in a state in which the width of the hole narrows toward the back of the hole h. Furthermore, the inclined surface is inclined with respect to the depth direction of the hole h at an angle θ that satisfies the following relational expression 1. Note that the depth direction is the linear direction in which the punch 11 reciprocates.
Relational formula 1 is 0°<θ≦30°
More preferably, Relational Expression 1 is in the range of 10°≦θ≦28°, and even more preferably, Relational Expression 1 is in the range of 15°≦θ≦25°. (10°, 20°, 25°, 28°, and 30° are values rounded off to the first decimal place.)

Here, we will provide a supplementary explanation of the significance of the inclined surface. In the second press working described above, the metal element 1 is punched out so as to be torn off from the metal plate 7, and it is believed that the torn off portion becomes the fracture surface. In the present invention, by providing an inclined surface, the timing at which the metal element 1 is torn off from the metal plate 7 is delayed, and it is possible to make it to be torn off beyond the upper surface in the thickness direction of the metal element 1. As a result, no trace of the metal element 1 being torn off from the metal plate 7 remains in the thickness direction range, that is, it is possible to make a surface without a fracture surface. On the other hand, as explained in the conventional example, when the entrance portion h1 of the hole h of the die 12 is chamfered with a radius of 0.01 to 1.0 mm and the back side of the hole h is formed parallel to the chamfered portion in the depth direction, even if many parts can be made into shear surfaces, traces of the metal element 1 being torn off from the metal plate 7 remain in the thickness direction range of the metal element 1. Therefore, the inclined surface in the present invention needs to have a certain length within the thickness direction of the metal element 1 so that no traces of the metal element 1 being torn off from the metal plate 7 remain.

Furthermore, the gap T between the punch 11 and the die 12 at the rear side h2 of the hole h with respect to the inclined portion satisfies the following relational expression 2.
Relational formula 2 is 0.1 μm<T<10 μm

It is desirable to perform finishing processing such as barrel polishing or chemical polishing on the metal element 1 after the second pressing process. The metal element 1 of the first embodiment described above is after finishing processing.

The metal element 1 of the first embodiment manufactured by the manufacturing method of the metal element 1 for slide fastener of the first embodiment described above does not have fracture surfaces 5 on the entire shear surface range of the outer surfaces of the left and right leg bodies 31 and the outer surface of the interlocking head 2, so the appearance of the metal element 1 is improved compared to a metal element 1 that has fracture surfaces 5 on the outer surfaces. The wider the entire shear surface range, the better the appearance of the metal element 1.

In addition, in the manufacturing method of the metal element 1 for slide fasteners of the first embodiment described above, an inclined portion is formed at the entrance portion h1 of the hole h of the die 12, the inclined portion has an inclined surface, and the inclined surface is inclined in such a way that the width of the hole h narrows toward the back of the hole h. Therefore, in the press processing for punching, the outer surfaces of the left and right leg main bodies 31 are formed in a state where they are pressed against the inclined surface during the period when they pass through the inclined surface. As a result, the entire shear surface range of the outer surfaces of the left and right leg main bodies 31 is formed without breaking (without forming any torn marks) within the thickness range of the metal element, and only the shear surface 4 is formed, and the appearance of the outer surfaces of the left and right leg main bodies 31 is improved compared to the manufacturing method using the press processing that simply punches out the metal element from the metal plate. Moreover, the inclined surface is made to satisfy the relational expression 1, and the gap T at the back side portion h2 of the hole h with respect to the inclined surface among the gaps between the punch 11 and the die 12 used in the second press processing is made to satisfy the relational expression 2, so that the surface roughness of the shear surface 4 is desired.

The present invention is not limited to the above-described embodiment, and can be modified as appropriate without departing from the spirit of the invention.

REFERENCE SIGNS LIST 1 Metal element 2 Interlocking head 21 Head body 22 Interlocking convex portion 23 Interlocking concave portion 25 Joint portion 26 Flat plate portion 3 Leg portion 31 Leg body 32 Clamping portion 32a Clamping surface 4 Shear surface 5 Fracture surface 7 Metal plate 9 Tape 9a Core portion 9b Tape body portion 11 Punch 12 Die C1, C2 Corner portion (curved surface)
h Hole h1 Entrance h2 Back side L0 Virtual line (Lower boundary line)
L1 Virtual line (first boundary line)
L2 Virtual line (second boundary line)
L3 Virtual line (third boundary line)
L4 Virtual line (upper boundary line)
T Gap S1, S2, S3, S4, S5, S6, S7, S8 Range θ Angle

Claims (10)

The toothed wheel has a head (2) and left and right legs (3),
The left and right leg portions (3) each include left and right leg body portions (31) extending in two directions from the engaging head portion (2), and left and right clamping portions (32) extending in directions approaching each other from the tip ends of the left and right leg body portions (31),
The left and right leg bodies (31) have, on their outer surfaces, portions that have only shear surfaces (4) over a certain width range and do not have fracture surfaces (5). The metal element (1) for a slide fastener according to claim 1, characterized in that the range of a certain width is a range (S1, S2) corresponding to the core (91) of the tape (9) sandwiched between the left and right leg bodies (31). The metal element (1) for a slide fastener according to claim 2, characterized in that the range of a certain width is the entire outer surface (S7, S8) of the left and right leg bodies (31). A metal element (1) for a slide fastener according to any one of claims 1 to 3, characterized in that the outer surface of the interlocking head (2) also has a portion that has only a shear surface (4) and does not have a fracture surface (5). a press working for forming projections and recesses, which plastically deforms the metal plate (7) in its thickness direction to form the interlocking convex portion (22) and the interlocking concave portion (23) of the interlocking head portion (2) of the metal element (1);
and a press working for punching out the metal element (1) to be a product from the metal plate (7) after the press working for forming the irregularities,
The punching press process forms the outer shape of the interlocking head portion (2) of the metal element (1) while forming the outer shape of the left and right leg portions (3) each having left and right leg body portions (31) extending in two directions from the interlocking head portion (2) and left and right clamping portions (32) extending in directions approaching each other from the tip portions of the left and right leg body portions (31);
The die (12) used in the press working for punching has an inlet (h1) of the hole (h) of the die (12) and a certain width range of a portion corresponding to the outer surface of the left and right leg main bodies (31) as an inclined portion having an inclined surface,
A manufacturing method for a metal element (1) for a slide fastener, characterized in that the inclined surface is inclined with respect to the depth direction of the hole (h) in a state in which the width of the hole (h) narrows toward the back of the hole (h). The manufacturing method for the metal element (1) for a slide fastener according to claim 5, characterized in that the range of the constant width corresponds to the core (91) of the tape (9) sandwiched between the left and right leg bodies (31). The method for manufacturing a metal element (1) for a slide fastener according to claim 5, characterized in that the range of a certain width is the entire outer surface of the left and right leg bodies (31). The method for manufacturing the metal element (1) for a slide fastener according to any one of claims 5 to 7, characterized in that the die (12) used in the press processing for punching has an inclined portion at the entrance portion (h1) of the hole (h) of the die (12) and at a portion corresponding to the outer surface of the interlocking head (2). The inclined surface is inclined at an angle θ with respect to the depth direction of the hole (h) that satisfies the following relational expression 1:
The method for manufacturing the metal element (1) for a slide fastener according to any one of claims 5 to 8, characterized in that the relational expression 1 satisfies 0°<θ≦30°. The inclined surface is inclined at an angle θ with respect to the depth direction of the hole (h) that satisfies the following relational expression 1:
The method for manufacturing the metal element (1) for a slide fastener according to any one of claims 5 to 8, characterized in that the relational expression 1 satisfies 10°≦θ≦28°.

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