JPH05293547A - Device for bending knife - Google Patents

Abstract

PURPOSE:To bend a knife in advance at a prescribed angle with high accuracy, in a device for bending in a prescribed shape a sheet punching knife with which a prescribed shape is punched out on a paper sheet, etc., in a punching press work. CONSTITUTION:The part to be champed by compression in the bending dies 11, 12 by which the knife B is compressed from both sides are formed in a circular arcuate shape opposite to each other perpendicularly against the top surface of a surface plate 10. Then, the center position of each radius of curvature is such for example that the bending die 11 on a moving and driving side, rather than the bending die 12 on a fixed side, is shifted to the top side of the surface plate 10. Then, when the knife B is clamped by compression with a pair of bending dies 11, 12, a component force (Fy) in the direction pressing down toward the top side of the surface plate 10 is actuated on the knife B. Consequently, without regulating the upper surface of the blade 15 of the knife B, the bending work is performed downward in the state where the back surface 16 of the knife is put along the top side of the surface plate 10.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thin-walled sheet-forming knife (hereinafter referred to as a knife) used for punching a sheet of paper, plastic, cardboard or the like into a predetermined shape by punching press processing or for making a crease in the sheet. ) Is bent into this predetermined shape.

[0002]

2. Description of the Related Art For example, as shown in FIG. 3, a knife A of this type is thin (for example, a wall thickness of 0.4 to 1.0 mm), strip-shaped, has a cutting edge 1, and has a substantially rectangular cross section. It is formed in a shape. The knife A is used by being fitted and fixed in the knife fitting groove 3 which is formed through the wooden knife holder 2 continuously. The knife fitting groove 3 is previously formed in a predetermined shape (shape corresponding to a punching die) by a saw or laser processing. On the other hand, the knife A is placed with its back 6 side along a surface plate (not shown), and
Bending is performed by sandwiching the both sides of the knife A with a pair of bending dies, and a predetermined bent portion 5 is formed.

[0003]

However, in the conventional apparatus for bending the knife A as described above, when clamping is performed with a pair of bending dies from both side surfaces of the knife A, the operation at that time is performed. Since the knife A may be flipped up or tilted on the surface plate, in order to prevent such a situation, the knife A is regulated from the upper surface of the cutting edge 1 toward the surface plate. Measures are taken to do so. This ensures an accurate bending angle of the knife A with respect to the back portion 6. However, as described above, restricting the knife A from the upper surface of the cutting edge 1 with respect to the surface plate cannot be said to be in a preferable working state for this knife A. Therefore, the present invention was devised in view of the above circumstances, and the back portion of the knife is set along the surface plate without restricting the upper surface of the blade edge of the knife, and an accurate bending angle is obtained with respect to the back portion. Thus, it is an object of the present invention to provide a bending apparatus capable of processing the knife.

[0004]

In order to achieve the above-mentioned object, the main means adopted by the present invention is, as its gist, a long thin plate having a cutting edge portion on one end side in the longitudinal direction thereof. In the device for placing the back side of the knife along the surface plate and bending the knife by clamping it from both side surfaces of the knife with the pair of bending dies, Is formed in a substantially arc shape so as to face each other in the vertical direction with respect to the upper surface of the surface plate, and the center position of each radius of curvature is relatively displaced in the vertical direction. It is a knife bending device.

[0005]

Operation: For example, one bending die is set in a stationary state and the other bending die is set in an operable state, and the center position of the radius of curvature of the bending die on the operating side is set to be greater than the center position of the radius of curvature of the other bending die. When the knife is clamped by the bending die when relatively displaced downward (upper surface side of the surface plate), a component force (Fy) in the direction of pushing down on the surface plate acts on the knife (Fig. 1). By this,
Even if the upper surface of the cutting edge of the knife is not restricted, it is possible to perform bending while the back part of the knife is placed on the surface plate.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments embodying the present invention will be described below with reference to the accompanying drawings for the understanding of the present invention. The following embodiments are examples of embodying the present invention and are not of the nature to limit the technical scope of the present invention. Here, FIG. 1 is a side sectional view of an essential part of a bending apparatus according to an embodiment of the present invention, and FIG. 2 is a plan view of an essential part of the bending apparatus. In the bending apparatus according to this embodiment, as shown in FIGS. 1 and 2, a set of bending dies 1 is provided on the upper surface of the surface plate 10.
1, 12 are arranged opposite to each other. Bending die 12
Is attached to a base 13 fixed to the lower surface of the surface plate 10, and the bending die 11 is movable along the upper surface of the surface plate 10 in the arrow 14 direction. It is supported by the table 13. The bending die 11 is moved and driven by an actuator (not shown). The pressing portions of the bending dies 12 and 11 are formed in a concave shape or a convex shape so that they can be fitted to each other with the knife B sandwiched therebetween in a plan view. Further, in a side view, the upper surface of the surface plate 10 is formed in an arc shape so as to face each other in a direction perpendicular to the upper surface, and the center position of each radius of curvature thereof is the center position on the bending die 12 side. The center position of the bending die 11 side is relatively shifted downward toward the upper surface of the surface plate 10. In the bending apparatus configured as described above, in the space portion between the bending dies 11 and 12, the knife B to be bent has its cutting edge 15 directed upward, and its back portion 16 has the back surface of the platen 10. It is placed along the upper surface. When the bending die 11 is moved and driven by an actuator (not shown), the knife B is pinched by a pair of bending dies 11 and 12 from both side surfaces thereof. B is subjected to a predetermined bending process. In this case, the knife B has a component force (F
y) acts. As a result, even if the upper surface of the cutting edge 15 of the knife B is not regulated at all, the bending process can be performed under the state where the back portion 16 is along the upper surface of the surface plate 10.
Therefore, the knife B can be machined so as to form an accurate bending angle with respect to the back portion 16 without any damage to the tip portion of the cutting edge 15. In this case, the pinching operation by the bending dies 11 and 12 is repeated a plurality of times instead of bending the knife B to a predetermined angle in one operation so that higher processing accuracy can be obtained. A method of pinching is used.

[0007]

As described above, according to the present invention, the back side of a knife, which is a long thin plate and has a cutting edge at one end in the longitudinal direction, is placed along the surface plate, and In a device that bends the knife by pressing it with a pair of bending dies from both sides of the knife, the pressing parts of the pair of bending dies are mutually perpendicular to the upper surface of the surface plate. The knife bending device is characterized in that it is formed in a substantially arc shape facing each other and the center position of each radius of curvature is relatively displaced in the vertical direction.
Even if the upper surface of the cutting edge of the knife is not regulated at all, the knife can be machined so that the back portion is aligned with the surface plate and the bending angle is accurate with respect to the back portion.

[Brief description of drawings]

FIG. 1 is a side sectional view of a main part of a bending apparatus according to an embodiment of the present invention.

FIG. 2 is a plan view of a main part of the bending device.

FIG. 3 is a perspective view for explaining the background art of the present invention and showing a state before a knife is attached to the knife holder.

[Explanation of symbols]

10 ... Surface plate 11, 12 ... Bending die 13 ... Base 15 ... Blade edge 16 ... Back B ... Knife

Claims (1)

[Claims] 1. A long thin plate-shaped knife having a cutting edge on one end side in the longitudinal direction thereof is placed along the backside of the knife along a surface plate, and a pair of side surfaces of the knife is provided. In a device that presses with a bending die to bend this knife, the pressing portions of the pair of bending dies are formed in a substantially arc shape so as to face each other in the direction perpendicular to the upper surface of the surface plate. At the same time, the center position of each radius of curvature is relatively displaced with respect to the vertical direction, and a knife bending apparatus.