JP2826996B2 - Shear punch - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tool for shear-joining an overlapped upper metal sheet and a lower metal sheet, and more particularly to a tool for shear-joining disposed on the lower metal sheet side. Further, the present invention relates to a shearing punch arranged and used on the upper metal sheet side.

[0002]

2. Description of the Related Art A general shearing tool and a shearing process will be described with reference to FIGS.

As shown in FIG. 10, a shearing punch 3 is arranged on the upper metal sheet 1 side, and a lower die is arranged on the lower metal sheet 2 side. The shearing punch 3 has a tip blade 3a at its tip. The lower mold has a blade holder 4 and a pair of cutting blades 5 and 6 arranged on both sides of an anvil portion 4 a of the blade holder 4. The portions 1a and 2a to be sheared by the shearing punch 3 are received from below by the anvil portion 4a of the blade holder 4. Each of the cutting blades 5, 6 has a cutting edge 5a, 6a at the upper inner edge.

As shown in FIGS. 11 and 12, the sheared portion 1a of the upper metal sheet 1 enters into the notch of the lower metal sheet 2, and thereby the surface direction of the two superposed metal sheets. Misalignment is prevented. Further, as apparent from FIG. 12, the sheared portions 1a and 2a are compressed by the tip blade 3a of the shearing punch 3 and the anvil portion 4a of the blade holder 4 to have a shape expanded in the width direction. Has become. Since the sheared portions 1a and 2a are located on the back surface side of the lower metal thin plate 2, these portions do not fall out of the holes formed by shearing. Thus, 2
The displacement of the metal sheets 1 and 2 in the thickness direction is prevented.

FIG. 13 shows a shear bonding step.
In the state shown in FIG. 13A, the shearing punch 3 comes into contact with the upper surface of the upper metal sheet 1 and the pair of lower mold blades 5, 6
Are in contact with the back surface of the lower metal sheet 2. In this state, the anvil part 4a of the blade holder and the lower metal sheet 2
Is formed between them.

In the state shown in FIG. 13B, the tip blade 3a of the shearing punch 3 and a pair of cutting blades 5,
A part of the two metal sheets 1 and 2 is sheared by the cutting edge 6. The sheared portion is received from below by the anvil portion 4a of the blade holder.

In the state shown in FIG. 13C, the sheared portion is compressed by the tip blade 3a of the shearing punch and the anvil portion 4a of the blade holder, and as a result, has a shape enlarged in the width direction. . The pair of cutting blades 5 and 6 are slightly moved in the width direction to allow the sheared portion to expand in the width direction.

FIG. 14 and FIG. 15 show a lower die for shear bonding which has been conventionally used. The illustrated lower die 7 for shear bonding includes a blade holder 8, a pair of cutting blades 9 and 10 located on both sides of an anvil portion 8 a of the blade holder 8, and a spring 13. Each of the cutting blades 9 and 10 is provided so as to be rotatable about axes 11 and 12. The spring 13 urges the pair of cutting blades 9 and 10 so as to contact the anvil portion 8a.

[0009]

In a shearing process as shown in FIG. 13B, a pair of cutting blades 9,
10 must be stationary. Then, FIG.
In the compression step as shown in (c), the pair of cutting blades 9 and 10 slightly rotate outward about the shafts 11 and 12 to expand the sheared portion in the width direction. Allow.

In the lower die 7 for shear bonding shown in FIGS. 14 and 15, a pair of cutting blades 9, 1
0 is urged by the spring 13 so as to contact the anvil portion 8a. Both side walls of the upper portion of the anvil portion 8a extend in parallel with the shear direction. Therefore, FIG.
At the time of the shearing process shown in FIG. 3B, there is a possibility that the pair of cutting blades 9 and 10 slightly rotate outward. If such rotation of the cutting blades 9 and 10 occurs during shearing, reliable shearing may not be realized.

Further, in the compression step as shown in FIG. 13 (c), the pair of cutting blades 9, 10 must be moved outward by expanding the shape of the sheared portion itself. However, since the upper ends of the cutting blades 9 and 10 are in contact with the lower metal sheet, the smooth movement of the cutting blades 9 and 10 is restricted, and consequently the sheared portion smoothly expands in the width direction. May not be done.

Cutting edges 9a, 10a are formed at the upper inner edges of the pair of cutting blades 9, 10, respectively. If the cutting edges 9a, 10a become worn,
The cutting blades 9, 10 must be replaced with new ones. A pair of cutting blades 9, 10
Are attached to the blade holder 8 via shafts 11 and 12, respectively, so that the cutting blade 9,
Prior to replacing 10, shafts 11 and 12 must first be removed. Removal of such a shaft is complicated.

Further, each of the cutting blades 9, 10
Since it is necessary to have a hole for receiving the shafts 11 and 12 therein, the thickness thereof must be increased to some extent in terms of strength. Furthermore, each cutting blade 9,
Since the portion 10 needs to have a portion pressed by the spring 13 in a region below the shafts 11 and 12, the length in the vertical direction is increased. From the viewpoint of material consumption efficiency, it is desirable that the size of the frequently replaced cutting blade be small.

Although not shown in FIG. 10, the shearing punch 3 generally has a bottomed cylindrical pad surrounding the tip blade 3a. Such a pad has a through slit in the bottom wall that allows the tip blade to pass. The pad remains in contact with the upper surface of the upper sheet metal while the tip blade moves down and shears.

In order to realize the above operation, the pad
It must be slidably held with respect to the punch body. Further, the pad must be prevented from falling down from the punch body. As an example for realizing this structure, it is conceivable to form an elongated hole extending up and down of the pad and provide a pin penetrating the elongated hole in the punch body. However, in the case of such a structure, the strength must be increased to some extent due to the provision of the elongated hole and the pin. Processing a long hole and attaching a pin are complicated.

An object of the present invention is to improve the structure for mounting the pad and the punch body. In particular,
An object of the present invention is to provide a structure in which a pad can be attached to a punch main body with a small number of parts and with a simple operation.

[0017]

A shearing punch according to the present invention includes a punch body, a pad, and a spring. The punch body has a tip blade for shearing at the tip. The pad has a bottomed cylindrical shape surrounding the tip blade of the punch main body, and has a through slit in the bottom wall for passing the tip blade. This pad is in contact with the upper surface of the upper thin metal sheet while the tip blade of the punch body moves downward and performs shearing. The spring always biases the pad downward.

The punch body has a large-diameter cylindrical portion having an outer diameter substantially equal to the inner diameter of the pad in a region located above the leading edge, and a large-diameter cylindrical portion located above the large-diameter cylindrical portion. And a small-diameter cylindrical portion having a small outer diameter. The upper portion of the pad is swaged in the diameter reducing direction to engage with the step between the large-diameter cylindrical portion and the small-diameter cylindrical portion, thereby preventing the pad from falling down.

In the above invention, the pad is engaged with the step of the punch body by caulking the upper portion thereof, whereby the pad is slidably held up and down along the punch body. At the time of this mounting, machining of a long hole and mounting of a pin are unnecessary, and the number of parts is small. Thus, a mounting structure with low manufacturing cost can be easily realized.

In a preferred embodiment, the punch body has a flange in a region located above the small-diameter column. The spring is located between the flange and the upper part of the pad. The upper portion of the pad reduced in diameter by caulking can relatively slide on the region where the small-diameter cylindrical portion is formed.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIGS. 1 to 4, a lower die for shear bonding according to an embodiment of the present invention will be described. The lower die 20 for shear bonding includes a blade holder 21, a pair of cutting blades 30 and 31, a spring 34, and a roll pin 35.

The blade holder 21 includes an anvil portion 22 for receiving a portion to be sheared by a shearing punch from below, upright wall surfaces 23 and 24 located on both sides of the anvil portion 22 and extending in the vertical direction. Walls 23, 24
Bottom walls 25, 26 extending outward from the bottom end of
And a through-hole 29 for receiving the roll pin 35.
Relief portions 27 and 28 are formed at the corners where the upright wall surfaces 23 and 24 intersect with the bottom wall surfaces 25 and 26 to avoid contact with the inner edges of the lower ends of the cutting blades 30 and 31.

As is apparent from FIG.
The distance between the pair of upright walls 23 and 24 located on both sides of the
It becomes narrower as it goes upward. The angle between the bottom wall surfaces 25 and 26 and the direction in which the shear force acts is an acute angle (90 ° -β).

A pair of cutting blades 30, 31
Are placed in contact with the upright walls 23, 24 and the bottom walls 25, 26 on both sides of the anvil portion 22 of the blade holder. The pair of cutting blades 30, 31 have exactly the same shape. Therefore, in order to avoid redundant description, details will be described for only one cutting blade.

The cutting blade 30 has a recess 32 on its outer surface. Furthermore, cutting blade 3
0 is a vertically symmetric shape having cutting edges 30a, 30b at the inner edges of its upper and lower ends. Therefore, when one of the cutting edges 30a becomes unusable due to wear, the cutting blade 30 can be turned upside down and the other cutting edge 30b can be used. Thus, the life of one cutting blade can be greatly increased.

The spring 34 is connected to each of the cutting blades 3.
In order to hold the 0, 31 on the blade holder 21, the cutting blades 30, 31 are elastically pressed against the upright walls 23, 24 and the bottom walls 25, 26. Specifically, the spring 34 is provided with the U-shaped portion 3 protruding downward.
4a, and a fitting portion 34b that is connected to the tip of the U-shaped portion 34a and fits into the recesses 32, 33 of the respective cutting blades 30, 31. The roll pin 35
It is inserted into the through hole 29 of the blade holder 21 and abuts the inner bottom end of the U-shaped portion 34a of the spring. The presence of the roll pin 35 prevents the spring 34 from coming off upward.

In the state shown in FIG. 2, the pair of fitting portions 34b of the spring 34 always exerts an elastic force to reduce the interval. With this elastic force, the pair of cutting blades 30 and 31 are elastically pressed and held against the upright wall surfaces 23 and 24 and the bottom wall surfaces 25 and 26 of the blade holder 21. By increasing the distance between the pair of fitting portions 34b of the spring 34, the cutting blade 30,
When the elastic force acting on the blade 31 is released, the pair of cutting blades 30 and 31 can be removed from the blade holder 21. Such a cutting blade 3
The removal of 0, 31 is easy and their attachment is also easy.

As shown in FIG. 2, the upper ends of the cutting blades 30 and 31 project above the anvil portion 22 of the blade holder 21. The space formed between the protruding cutting blades 30, 31 is:
It is in the form of a divergent spread that spreads downward.

Next, a shearing punch employed as an embodiment of the present invention will be described with reference to FIGS. The shearing punch 40 includes a punch body 41 and a pad 46.
And a compression spring 50.

The punch main body 41 has a tip blade 42, a large-diameter cylindrical portion 43 located thereon, and a small-diameter cylindrical portion 44 located thereon and having an outer diameter smaller than that of the large-diameter cylindrical portion.
And a flange 45 in an area further above
And

The pad 46 has a bottomed cylindrical shape surrounding the tip blade 42 of the punch body 41, and has a through slit 48 in the bottom wall 47 through which the tip blade 42 passes. The pad 46 is in contact with the upper surface of the upper thin metal sheet while the tip blade 42 of the punch body moves downward and performs shearing. The compression spring 50 is disposed between the upper end of the pad 46 and the flange 45 of the punch body 41, and constantly urges the pad 46 downward.

The pad 46 must be slidably held on the punch body 41. The pad 46
Must be prevented from falling out of the punch body 41 downward. In the preferred embodiment of the present invention, caulking is performed to hold the pad 46 slidably on the punch body 41 without requiring any special parts for mounting the pad 46. Specifically, the upper portion of the pad 46 is swaged in the diameter reducing direction, so that the swaged portion 49 is engaged with the step between the large-diameter cylindrical portion 43 and the small-diameter cylindrical portion 44 of the punch body 41.
As is apparent from FIG. 7, the inner diameter of the pad 46 and the outer diameter of the large-diameter cylindrical portion 43 are approximately equal. Since the swaged portion of the pad 46 is smaller in diameter than the inner diameter of the pad 46, it does not fall down beyond the large-diameter cylindrical portion. The upper portion of the pad 46 reduced in diameter by caulking can relatively slide on the region where the small-diameter cylindrical portion 44 is formed.

FIG. 9 sequentially shows the steps of shear joining using the joining tool according to the present invention.

In the state shown in FIG. 9A, the tip blade 42 of the punch body 41 and the bottom surface of the pad 46 abut on the upper metal sheet 1, and the upper end surfaces of the pair of cutting blades 30, 31 are connected to the lower metal plate. It is in contact with the back surface of the thin plate 2.

FIG. 9B shows a state immediately after shearing. A part of the upper thin metal sheet 1 and the lower thin metal sheet 2 is partially sheared by the tip blade 42 of the punch body and the cutting edges 30a and 31a of the pair of cutting blades. The sheared portion is located in the space between the upper portions of the pair of cutting blades 30, 31 projecting above the anvil portion 22 of the blade holder. As is clear from the figure, a slight space is formed on both sides of the part where the shearing has been performed.
Therefore, as shown in FIG. 9C, when the sheared portion is compressed between the punch body 41 and the anvil portion 22, it can be smoothly expanded in the width direction.

In the shearing step shown in FIG. 9B, a force is applied to the pair of cutting blades 30 and 31 from above to below. The force is received by the bottom wall surfaces 25 and 26 of the blade holder 21. As described above, since the bottom wall surfaces 25 and 26 and the direction in which the shear force acts are at an acute angle, the reaction force exerted from the bottom wall surfaces 25 and 26 causes the upper ends of the pair of cutting blades 30 and 31 to move together. It works to get closer. Therefore, at the time of shearing, the pair of cutting blades 30 and 31 are reliably prevented from spreading laterally.

As described above, one of the blade holders 21
Since the interval between the pair of upright wall surfaces 23 and 24 is made narrower as it goes upward, slight gaps are formed on both sides of the sheared portion, so that the expansion in the width direction by compression can be smoothly performed. Can be done. As shown in FIG. 9C, the pair of cutting blades 30 and 31 move slightly outward due to the widthwise enlargement of the sheared portion. This movement is performed against the elastic force of the spring 34. In FIG. 9, illustration of the spring 34 is omitted.

If one of the cutting blades 30, 31 becomes unusable due to wear, the cutting blades 30, 31 are turned upside down and the other cutting edge is used.

Although the embodiment of the present invention has been described with reference to FIGS. 1 to 9, the present invention is not limited to the illustrated embodiment. Various modifications and variations are possible within the equivalent scope of the present invention. Further, although the terms “up” and “down” are used as terms, they are merely used for specifying a certain direction for convenience, and are not limited to absolute vertical directions. Upside down the structure shown,
Alternatively, the shear punch and the lower die may be aligned in the horizontal direction.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of a lower die for shear bonding used as an embodiment of the present invention.

FIG. 2 is a front view of a lower die for shear bonding.

FIG. 3 is a front view of the blade holder.

FIG. 4 is a perspective view of a cutting blade.

FIG. 5 is an exploded perspective view of a shearing punch used as one embodiment of the present invention.

FIG. 6 is a front view of a shearing punch.

FIG. 7 is a sectional view of a shearing punch.

FIG. 8 is a view showing a process for attaching a pad to a punch holder by caulking.

FIG. 9 is a view sequentially showing a step of shear-joining using the shear-joining tool according to the present invention.

FIG. 10 is a perspective view showing a general shear joining tool.

FIG. 11 is a perspective view showing two metal thin plates joined by shearing.

FIG. 12 is a sectional view showing a thin metal plate joined by shearing.

FIG. 13 is a view sequentially showing a conventional shear joining process.

FIG. 14 is a front view showing a conventional lower die for shear bonding.

FIG. 15 is a cross-sectional view showing a conventional lower die for shear bonding.

[Explanation of symbols]

 Reference Signs List 20 Lower die for shear bonding 21 Blade holder 22 Anvil part 23, 24 Upright wall 25, 26 Bottom wall 30, 31 Cutting blade 34 Spring 40 Shear punch 41 Punch body 42 Tip blade 43 Large cylindrical part 44 Small cylindrical part 46 Pad 48 Through slit 49 Caulking part 50 Compression spring

Claims (2)

(57) [Claims] 1. An upper metal sheet and a lower metal sheet which are overlapped with each other and are used by being arranged on the upper metal sheet side in correspondence with a lower die for shear bonding arranged on the lower metal sheet side. A punch body having a tip blade for shearing at a tip thereof, and a bottomed cylindrical shape surrounding the tip blade of the punch body portion,
A pad having a through-slit on the bottom wall through which the tip blade passes, wherein the pad is in contact with the upper surface of the upper metal thin plate while the tip blade of the punch body moves downward and performs a shearing process; A spring that constantly biases the pad body downward, the punch body portion has a large-diameter cylindrical portion having an outer diameter substantially equal to the inner diameter of the pad in a region located above the tip blade, A small-diameter cylindrical portion located above the large-diameter cylindrical portion and having an outer diameter smaller than the large-diameter cylindrical portion, and the upper portion of the pad is caulked in the diameter-reducing direction to form the large-diameter cylindrical portion and Engage with the step with the small diameter cylindrical portion, thereby preventing the pad from falling down,
Shear punch. 2. The punch body has a flange in a region located above the small-diameter column, and the spring is arranged between the flange and an upper end of the pad. The shearing punch according to claim 1, wherein an upper portion of the pad reduced in diameter by the caulking is relatively slidable on a region where the small-diameter cylindrical portion is formed.