JP5085779B1 - How to open a through hole in leather - Google Patents

Abstract

A through hole is made in a leather without causing a laceration.
A piercing rod 10 includes a flat tip surface 11 and an outer surface 12 surrounding an edge of the tip surface 11. The tip surface 11 is set perpendicular to the pressing direction P1 of the punching bar 10 against the leather L. The outer side surface 12 is set to have an angle with respect to the front end surface 11 vertical or an acute angle than vertical. The method of making a through-hole in the leather L with the punching rod 10 includes the first procedure of spreading the leather L in a flat shape so that the surface L1 side is exposed, and the tip surface 11 of the punching rod 10 on the surface L1 of the leather L. In a state where it is parallel to the surface, the drilling rod 10 is pushed perpendicularly to the front surface L1 of the leather L, and the second step of forming the depressed hole L3 on the front surface L1 side of the leather L and the back surface L2 of the leather L are removed. And a third procedure for processing the depressed hole L3 into a through hole.
[Selection] Figure 12

Description

The present invention relates to a method of drilling through-holes in the skin leather. Specifically, by pressing the leather which is spread flat, it relates to a method to open more leather through hole drilling rods that can pierce this leather.

  Conventionally, when mass-producing leather products, it has been widely practiced to cut and process the raw material leather with a punching die. Here, when it is necessary to open a through-hole in a leather product, it is generally performed that a hole-piercing rod with a sharp tip is pressed against the leather and inserted (see, for example, Patent Document 1).

JP 2006-000155 A

However, the above-described conventional technique has a problem that a fine laceration occurs at the edge of the through-hole formed in the leather and the appearance of the leather product is deteriorated. In addition, since the laceration causes stress concentration in the leather product, there is a problem that the durability of the leather product is greatly reduced.
The present invention has been devised to solve the above problems. That is, the problem to be solved by the present invention is to provide a method of making a through hole in leather without causing a laceration, and a drilling rod for realizing this method.

In order to solve the above problems, the leather cutting die of the present invention takes the following means.
First, the first invention is a punching rod capable of making a hole in the leather by pressing it against the leather that is spread in a flat shape so as to abut on the flat plate . This perforated bar has a tip surface that forms the entire tip that is pressed against the leather in a flat shape, and an outer periphery that is formed adjacent to the edge of the entire circumference of the tip surface. And a side surface. The tip surface is set so as to be perpendicular to the direction in which the perforated bar is pressed against the leather , and the leather is sandwiched between the flat plate so that it can be crushed without being inserted. It is configured . The outer surface is set such that the angle of the outer surface with respect to the tip surface is vertical or acute.
The present inventor said that when the hole is made in the leather, the tear at the edge of the hole is caused by the leather fibers being pushed and spread by the punching bar when the punching bar is pressed against the leather. This is the headline and the present invention. That is, according to the present invention, the means for solving the above-mentioned problem is to prevent the fibers of the leather from being spread when the perforated bar is pressed against the leather.
According to the first aspect of the present invention, the hole punching bar is pressed against the leather, and the hole is cut by cutting on the side where the leather is pressed. For this reason, the leather fibers are not spread out by the outer diameter of the drilling rod at the edge of the hole. Thereby, a hole can be opened without causing a laceration in the leather, and the appearance and durability of the leather product can be improved.

Next, according to a second aspect of the present invention, in the first aspect described above, the perforating rod is formed in a cylindrical shape, and the bottom surface on one side of the column is formed to be the tip surface of the perforating rod. Is.
According to the second aspect of the present invention, the perforated bar is formed in a simple and strong shape such as a cylindrical shape. As a result, it is possible to make a hole having a smaller diameter than conventional ones by making the hole-piercing bar thinner than before. In addition, it is possible to reduce the manufacturing cost of the drilling rod by reducing the labor for processing the drilling rod.

Furthermore, the third invention includes a tip surface formed in a flat shape, and the outer surface formed so as to surround the edge of the entire circumference of the tip surface is perpendicular or perpendicular to the tip surface. This is a method in which a perforated bar formed so as to form an acute angle is pressed against leather spread out in a flat shape, and a through hole is formed in the leather with the perforated bar. In this method, the first step of spreading the leather in a flat shape so that the surface side of the leather is exposed, and the punched bar is attached to the leather with the tip end surface of the punched bar parallel to the surface of the leather. A second step of forming a recessed hole on the surface side of the leather by pushing it perpendicularly to the surface of the leather, and a third step of processing the recessed hole into a through hole by removing the back surface of the leather. Yes.
Leather fibers are crushed to form a high-strength compressed layer. For this reason, when the flat tip end surface of the perforated bar is applied to the leather and pushed in, the leather is crushed by the front end surface of the perforated bar to form a compression layer. Thereby, it becomes difficult to make a through-hole by inserting the punching rod into the leather.
According to the third aspect of the present invention, the holed bar is pushed vertically into the leather and the leather is locally crushed to form a depressed hole, and then the leather opposite to the depressed hole is formed with the holed bar. Remove the compressed layer. Thereby, a through-hole can be opened in the leather without spreading the leather fibers. Here, by forming the depression hole on the front side of the leather, the leather to be removed can be positioned on the back side, and deterioration of the appearance of the leather product can be reduced.

Furthermore, the fourth invention, in the first procedure of the third invention described above, spreads the leather on a flat plate having a restoring force in a flat shape so that the back side of the leather contacts the flat plate, In the third procedure, the leather is pulled away from the flat plate and the back surface of the leather is removed.
According to the fourth aspect of the present invention, in the first procedure, it is easy to spread the leather in a flat shape along the flat plate. In the second procedure, the leather pushed by the punching rod is supported by the flat plate. can do. For this reason, the workability | operativity at the time of opening a through-hole in leather improves. Here, even if the flat plate is deformed by being pushed from the perforating rod in the second procedure, it can return to its original state by its restoring force. For this reason, the same flat plate can be used repeatedly and the cost at the time of opening a through-hole in leather can be reduced.

1 is a side view of a punching die to which an embodiment of a punching rod according to the present invention is applied and a schematic diagram showing a method of using the punching die. It is a top view showing leather immediately after being cut by the above punching die. It is the III-III sectional view taken on the line of FIG. It is a perspective view showing the use condition of the cut leather. It is a perspective view which shows the structure by the side of the blade edge | tip of the said cutting die. It is a perspective view showing the structure on the opposite side to the blade edge | tip of the said cutting die. It is the VII-VII sectional view taken on the line of FIG. It is a perspective view showing the hole punch of the said embodiment. It is sectional drawing showing the process of making a through-hole in leather with the punching rod of the said embodiment, and represents the 1st procedure of this invention. It is sectional drawing showing the process of making a through-hole in leather with the drilling rod of the said embodiment, and represents the procedure between the 1st procedure of this invention, and a 2nd procedure. It is sectional drawing showing the process of making a through-hole in leather with the punching rod of the said embodiment, and represents the 2nd procedure of this invention. It is the elements on larger scale of FIG. It is sectional drawing showing the process of making a through-hole in leather with the punching rod of the said embodiment, and represents the 3rd procedure of this invention.

EMBODIMENT OF THE INVENTION Below, the form for implementing this invention is demonstrated using drawing.
First, the structure of the punching rod 10 according to one embodiment will be described with reference to FIGS. 1 to 13. As shown in FIGS. 1 to 6, the punching rod 10 is integrally attached to the punching die D (see FIGS. 5 and 6). When the punch 10 is pressed against the leather L which is flattened to cut the leather L into a leather product L5 (see FIGS. 2 to 4) (see FIG. 1), It is used for opening a depression hole L3 in the leather product L5 (see FIGS. 2 and 3). In the present embodiment, as shown in FIG. 4, the leather product L5 is a part of the shift knob S, and the recessed hole L3 is processed into a through-hole L4 so that the leather product L5 is replaced with another shift knob S. Used to sew the leather part S1.

As shown in FIG. 5 to FIG. 7, the punching die D includes a frame plate portion D <b> 1 (see FIG. 7) formed in a flat plate shape, and a blade portion for cutting a plurality of perforated bars 10 and leather L. D2 and a pedestal portion D3 (see FIG. 7) for separating the blade edge D4 of the blade portion D2 from the contact surface D5 of the punching die D are attached. Thereby, arrangement | positioning of each drilling rod 10 and the blade part D2 becomes easy. Furthermore, it is possible to repeatedly produce the leather product L5 having the same shape by fixing the relative positions of the perforating bars 10 and the blade part D2.
As shown in FIGS. 5 to 7, the frame plate portion D1 is formed in a flat plate shape (see FIG. 7) corresponding to the shape of the leather product L5, and a blade portion D2 is attached to the entire periphery of the edge portion. (See FIGS. 5 and 6). Thereby, it is easy to imagine the arrangement of the leather product L5 cut by the blade portion D2, and the leather product L5 can be efficiently produced from the leather L. The frame plate portion D1 is set to be perpendicular to the pressing direction P1 (see FIG. 1) of the punching die D.

As shown in FIGS. 5 to 7, the blade D2 is formed by bending a rectangular metal plate so as to surround the entire periphery of the edge of the frame plate D1 (see FIGS. 5 and 6). It is the structure which formed the blade edge | tip (refer FIG. 7) D4 of a single blade along the long side of the side (lower side seeing in FIG. 7). Here, the “single-edged cutting edge” refers to a cutting edge formed at the edge of the plate material along the extended surface of the plate surface on one side.
As shown in FIG. 7, the blade portion D2 surrounds the frame plate portion D1 in a state where the plate surface on the blade edge D4 side is in contact with the edge portion of the frame plate portion D1 perpendicularly. As shown in FIGS. 1 and 12, the blade portion D2 has a plate surface on the blade edge D4 side that is parallel to the pressing direction P1 of the punching die D (see FIG. 12), and the blade edge D4 is It arrange | positions so that it may be located on the plane perpendicular | vertical to the pressing direction P1 (refer FIG. 1).
By each said structure, the blade part D2 can cut the leather L with a uniform force. Further, when the blade part D2 cuts the leather L, the external leather L on the side separated as the leather product L5 is not subjected to an external force so that scratches or wrinkles given to the leather product L5 by the cutting process Damage can be reduced.

As shown in FIGS. 5 to 7, the pedestal portion D3 is made of an elastic material such as rubber (see FIG. 7) from the plate surface of the frame plate portion D1 to the cutting edge D4 side of the blade portion D2 (as viewed in FIG. 7). Side). As shown in FIG. 9, the pedestal portion D3 is formed on the other member when the die D comes into contact with another member (for example, the leather L shown in FIG. 9) from the blade portion D2 side (the lower side in the drawing). The blade D2 comes into contact with the contact surface D5 before the blade tip D4. Thereby, the cutting edge D4 of the blade part D2 can be separated so as not to come into contact with other members, and the safety of the punching die D can be improved.
Further, as shown in FIGS. 10 to 12, the pedestal portion D3 is compressed by the pressing force in the pressing direction P1 by the pressing device P, and the cutting edge D4 of the blade portion D2 is pressed in the pressing direction P1 side (in FIG. 11). It is designed to protrude downward (seeing below). Thereby, the cutting die D can be set in the press device P in a state in which the cutting edge D4 of the blade portion D2 is separated, and the leather L can be cut without having to remove the pedestal portion D3.

Here, the pedestal portion D3 is disposed so as to be separated from the perforating rod 10 and the blade portion D2, as shown in FIGS. Accordingly, as shown in FIG. 11, the punching rod 10 and the blade portion D2 are not pressed against the pedestal portion D3 when the pedestal portion D3 is compressed and the leather L is cut. Can be suppressed.
Further, the contact surface D5 of the pedestal D3 is set to be perpendicular to the pressing direction P1 (see FIG. 1) of the punching die D as shown in FIGS. Thereby, the pressing force of the pressing direction P1 by the press apparatus P can be uniformly transmitted to the blade edge D4 of the blade portion D2.

As shown in FIGS. 7 and 8, the punching rod 10 is formed in a cylindrical shape (see FIG. 8) from metal and is perpendicular to the plate surface of the frame plate portion D1 (that is, the pressing direction of the punching die D). It is inserted (in a direction along P1) (see FIG. 7). In other words, the punching rod 10 is formed in a simple and high-strength shape such as a cylindrical shape.
With the above configuration, the hole punching bar 10 can be made thinner than before, and a hole having a smaller diameter than that of the conventional one can be made in the leather L. In addition, it is possible to reduce the labor for processing the drilling rod 10 and reduce the manufacturing cost of the drilling rod 10.

The perforating rod 10 is configured such that the bottom surface on one side (the lower side in FIG. 7) of the cylinder is the tip surface 11 and the side surface around the tip surface 11 of the column is the outer surface 12. In other words, the outer surface 12 around the tip surface 11 of the punching bar 10 is set perpendicular to the tip surface 11.
With the above configuration, by pressing the punching bar 10 perpendicularly to the leather L, the depression L3 is opened in the leather product L5 while preventing the outer diameter of the punching bar 10 from spreading the fibers of the leather L. Will be able to. For this reason, it is possible to improve the appearance and durability of the leather product L5 by opening the depression L3 without causing a tear in the leather product L5.

Here, a method of forming the through hole L4 in the leather product L5 by pressing the punching die D to which the above-described punching rod 10 is attached to the leather L spread in a flat shape to cut the leather product L5. explain.
In the method of this embodiment, as shown in FIGS. 9 to 13, in order to form the through hole L4 by cutting the leather L into the leather product L5, the above-mentioned punching die D and punching die D are A pressing device P that presses in the pressing direction, a flat plate B that becomes a base of the leather L when the pressing device P is pressed, and a leather machine G (see FIG. 13) that can process the leather product L5. Is used.
In the present embodiment, the leather L to be cut is natural leather, and the thickness t1 (see FIG. 9) is in the range of 1.1 mm to 1.3 mm. Further, the thickness t3 (see FIG. 13) of the leather product L5 after the leathering process is set in a range of 1.0 mm to 1.1 mm.

  When cutting the leather L, first, the leather L is spread on the flat plate B in a planar shape as shown by a solid line in FIG. At this time, the leather L is spread so that the back surface L2 side (the lower side in the drawing) is in contact with the flat plate B and the front surface L1 side (the upper side in the drawing) is exposed upward. By spreading the leather L so as to contact the flat plate B, it becomes easy to spread the leather L in a flat shape. Here, the above procedure corresponds to the “first procedure” in the present invention.

Next, as shown by phantom lines in FIG. 9, the cutting die D is placed on the surface L1 of the leather L spread in a flat shape with the cutting edge D4 facing down, and the arrangement of the cutting die D is adjusted. . Here, since the pedestal part D3 of the punching die D is separated so that the cutting edge D4 of the blade part D2 does not come into contact with the leather L, the operator (not shown) does not damage the surface L1 of the leather L. The arrangement of D can be adjusted.
Here, the contact surface D5 of the frame plate portion D1 and the pedestal portion D3 is perpendicular to the pressing direction P1 (see FIG. 10) of the punching die D, as shown in FIGS. Is set. Further, the hole punching rod 10 is inserted in a direction along the pressing direction P1. For this reason, the front end surface 11 of the hole punching bar 10 is disposed so as to be parallel to the surface L1 of the leather L.

Then, as shown in FIG. 10, the pressing device P is brought into contact with the punching die D from above, and the pressing force is applied to the punching die D in the pressing direction P1. At this time, the pedestal portion D3 of the punching die D is compressed by the pressing force of the pressing device P, and the cutting edge D4 of the blade portion D2 protrudes toward the pressing direction P1 side (the lower side in the drawing) of the pedestal portion D3 to surface the leather L. Assigned to L1.
Here, as shown in FIGS. 7 and 10, the cutting edge D4 of the blade portion D2 and the distal end surface 11 of the drilling rod 10 are in the pressing direction P1 side (in FIG. 10) as viewed from the frame plate portion D1. The amount of protrusion to the lower side is set to be equal. For this reason, when the cutting edge D4 of the blade portion D2 is applied to the surface L1 of the leather L by the press device P, the punching bar 10 is applied to the surface L1 of the leather L perpendicularly.

Subsequently, as shown in FIGS. 11 and 12, the pressing device P is operated to strongly press the punching die D in the pressing direction P1. At this time, the pedestal portion D3 of the punching die D is further compressed by the pressing force of the press device P, and the blade edge D4 of the blade portion D2 further protrudes in the pressing direction P1 side (lower side in the drawing) of the pedestal portion D3. For this reason, the leather L is cut into a shape corresponding to the frame plate part D1 of the punching die D and separated as a leather product L5.
The punching rod 10 is pushed perpendicularly to the surface L1 of the leather L by the pressing force of the pressing device P. For this reason, the front end face 11 of the punching bar 10 locally presses the leather L in a state parallel to the surface L1 of the leather L. Thereby, the punching bar 10 cuts the surface L1 of the leather L to form a depressed hole L3 on the surface L1 side (the upper side in the drawing) of the leather L. Here, the above procedure corresponds to the “second procedure” in the present invention.

By the way, the outer surface 12 around the tip surface 11 of the punching bar 10 is set perpendicular to the tip surface 11, so that the punching bar 10 does not spread the fibers of the leather L. Thereby, the depression L3 can be opened without causing a tear in the leather L, and the appearance and durability of the leather product L5 can be improved.
In addition, when forming the depression hole L3, the punching rod 10 crushes the fiber of the portion corresponding to the depression hole L3 of the leather L with the flat front end surface 11, and the back surface L2 of the leather L from FIG. Make it protrude downward. Thereby, the punching rod 10 forms the compression layer L6 on the back surface L2 side without inserting the leather L.

As shown in FIG. 3, the leather product L5 separated from the leather L by each procedure between the first procedure and the second procedure has a depression hole L3 at a position where the through hole L4 is to be formed. Is formed. The depressed hole L3 opens toward the surface L1 side (the upper side in the drawing) of the leather product L5. The compressed layer L6 described above is formed on the side opposite to the opening of the depression hole L3 (the lower side in the drawing).
The thickness t2 (see FIG. 13) of the compression layer L6 is determined by known physical quantities such as the arrangement and shape of each component of the punching die D, the pressing force of the pressing device P, and the thickness t1 of the leather L. . For this reason, the thickness t2 can be set to a predetermined thickness in advance by calculation or experiment. In the present embodiment, t2 is set in a range of 0.1 mm to 0.2 mm.

With the above configuration, the depressed layer L6 can be processed into the through hole L4 by removing the compressed layer L6 by a predetermined thickness along the surface opposite to the opening of the depressed hole L3 of the leather product L5. Here, the above procedure corresponds to the “third procedure” in the present invention.
Specifically, as shown in FIG. 13, the leather product L5 separated from the leather L is pulled away from the flat plate B, and the surface of the leather product L5 on the compression layer L6 side (the lower side in the drawing) is thickened by the leather machine G. A leathering process is performed to remove only t2. That is, the leather product L5 is subjected to a leathering process from a thickness t1 (1.1 mm to 1.3 mm in the present embodiment) to a thickness t2 (0.1 mm to 0.2 mm in the present embodiment) to obtain a thickness t3. (In this embodiment, it is processed to be 1.0 mm to 1.1 mm).
Here, the depressed hole L3 opens toward the surface L1 side (the upper side in the drawing) of the leather product L5. For this reason, the said compression layer L6 is located in the back surface L2 side (illustration lower side) of the leather product L5. Thereby, when processing the depression hole L3 into the through-hole L4, the part removed from the leather product L5 can be used as the back surface L2 of the leather product L5, and deterioration of the appearance of the leather product L5 can be reduced.

By the way, in the second procedure described above, the pressing force that the leather L receives from the press device P through the punching die D is received by the elastic deformation of the flat plate B as shown in FIGS. It has become. Thereby, the pressing force that the leather L receives through the blade portion D2 of the punching die D and the punching rod 10 is supported by the flat plate B, and the certainty of the cutting processing of the leather L and the formation of the recessed hole L3 is improved. Can do.
As shown in FIGS. 9 to 12, the flat plate B is made of a synthetic resin having a restoring force. For this reason, even if the flat plate B is pushed and deformed by the punching rod 10 in the second procedure described above (see FIGS. 11 and 12), the flat plate B returns to the original state (see FIG. 9) by its restoring force. It has become. Thereby, the compressed layer L6 described above can be pushed back to the depressed hole L3 side (upper side as viewed in FIG. 11) of the leather L, and the compressed layer L6 can be easily removed in the third procedure described above. Moreover, in the method of forming the through hole L4 in the leather product L5 described above, the same flat plate B can be used repeatedly, and the cost for forming the through hole L4 in the leather L can be reduced.

The present invention is not limited to the appearance and configuration described in the above-described embodiment, and various modifications, additions, and deletions can be made without changing the gist of the present invention. For example, the following various forms can be implemented.
(1) The outer surface around the distal end surface of the drilling rod does not need to be a side surface of a cylinder. For example, the drilling rod can be formed in a truncated cone shape whose diameter increases toward the distal end side. That is, it is possible to set the outer surface around the tip surface of the punch bar so that the angle with respect to the tip surface is more acute than vertical. Even when this configuration is used, it is possible to make a hole in the leather while preventing the fiber of the leather from being spread by the outer diameter of the punching rod.
(2) In this embodiment, natural leather is used as the leather to be cut. However, even when this leather is artificial leather, the punching rod of the present invention exhibits the same function as in this embodiment.
(3) The shape of the punching die and the arrangement of each component of the punching die including the punching rod can be set as appropriate.
(4) In this embodiment, the means used for forming the through hole in the leather product can be appropriately determined. For example, in the third procedure, leathering can be performed using a leather knife instead of a leather cutter. Moreover, the back surface of leather can also be removed by grinding using a grinder.
(5) In the third procedure of the present embodiment, the removal amount of the back surface of the leather does not need to be equal to the thickness of the compression layer, and the back surface of the leather may be removed to be thicker than the thickness of the compression layer. Moreover, the removal amount of the back surface of leather can also be changed for every part of leather.
(6) The method of using the perforated bar is not limited to the method of forming the through hole in the leather by integrally attaching to the punching die, and for example, the recessed hole may only be formed in the leather by the perforated bar. Further, only the perforated rod can be used independently of the punching die.

DESCRIPTION OF SYMBOLS 10 Hole punch 11 Front end surface 12 Outer side surface B Flat plate D Die type D1 Frame plate part D2 Blade part D3 Base part D4 Blade edge D5 Abutting surface G Leather machine L Leather L1 Front surface L2 Back surface L3 Recessed hole L4 Through hole L5 Leather product L6 Compression layer P Press device P1 Pressing direction S Shift knob S1 Leather part t1 Thickness t2 Thickness t3 Thickness

Claims (2)

  It has a tip surface formed in a flat shape, and an outer surface formed so as to surround an edge of the entire circumference of the tip surface is formed so as to form an acute angle with respect to the tip surface or perpendicular to the tip surface. A method of pressing a punched rod against a leather spread in a flat shape and opening a through hole in the leather with the punched rod,
  A first step of spreading the leather in a flat shape so that the surface side of the leather is exposed;
  A second hole is formed by pressing the perforating bar perpendicularly to the surface of the leather with the tip end surface of the perforated bar parallel to the surface of the leather, thereby forming a recessed hole on the surface side of the leather. Procedure and
  A third step of removing the back surface of the leather and processing the depressed hole into a through hole, and a method of opening a through hole in the leather.   A method of opening a through hole in the leather according to claim 1,
  In the first step, the leather is spread on a flat plate having a restoring force so that the back side of the leather is in contact with the flat plate, and in the third step, the leather is pulled away from the flat plate. And removing the back surface of the leather, and forming a through hole in the leather.

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