JPH0788799A - Rotary punch unit - Google Patents

Abstract

PURPOSE:To surely discharge punching chips to the downward of a die hole by providing a protrusion in the point end of a punch. CONSTITUTION:In the case of punching a punched sheet material while meshing a rotating punch 1 and die 2, a protrusion 3 provided in a point end surface of the punch 1 makes action of pressing the punched sheet into the interior of a die hole prior to punching or from the halfway of punching. In this way, punching is advanced in a condition that tensile stress is generated in the punched sheet in its surface internal direction. In a side of generating a punching chip of the punched sheet material, by generating a slip in the point end surface of the punch 1 at each advancing shear, a sticking condition to an edge of the punch 1 is released, and further the punching chip, while formed into a tongue shape to provide a seesaw condition with the point end of the protrusion 3 serving as the supporting point, is tilted by placing the point end part of the chip downward and separated from both the edge of the punch and a surface of the die hole 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary punch unit mainly used for punching a binding hole or the like for filing a sheet material. More specifically, the present invention relates to a rotary punch unit that ensures the removal of punched chips below the die hole after punching.

[0002]

2. Description of the Related Art When filing a sheet material such as copied paper, it is necessary to punch a binding hole. Conventionally, as a method of punching the binding holes, a method of manually aligning the ends of a plurality of copied sheets and punching them with a punching machine (commonly called a punch or a manual punch) is widely used. However, the method of manually punching using a punching machine has the troublesomeness of manually aligning the edges of the paper and checking the punching position. There has been a demand for the device to be built in and punched almost simultaneously with copying. As this punching method, there is known a method of mechanically aligning the edges of sheets in a copying machine and punching and punching them with a vertically moving punch and a fixed die.

In the conventional punch described above, the axis of the die hole and the axis of the punch are arranged substantially in a straight line, and the punch moves linearly in the same direction as the axis of the die hole for punching (hereinafter referred to as reciprocation). Therefore, it is necessary to temporarily stop the transportation of the sheet material when punching. In order to further improve the efficiency of a copying machine or the like, it is desirable that the sheet material be perforated while being conveyed (during running). Therefore, the sheet material is supplied between the punch and the die which are driven to rotate synchronously with each other around the shafts respectively arranged on both sides of the sheet material to be punched and mesh with each other during the rotation to perform a predetermined punching. A rotary punch for performing is known. In these punches, it is important that the punched chips after punching are surely discharged from the pass line of the sheet material, the die hole, or the like. If punching scraps remain near the pass line or die hole of a copy machine, etc., the punching scraps are likely to be caught again in the meshing part of the punch and die, resulting in poor punching. Are likely to adhere to the vicinity of the sensor and deteriorate the function of the sensor or cause a malfunction.

In the case of the reciprocating punch unit described above, punching is performed by increasing the amount of the punch fitted in the die hole so that the tip of the punch reaches the flank of the die hole as shown in FIG. It is relatively easy to ensure that the waste is removed from the lower side of the die hole 4. However, if an attempt is made to increase the amount of insertion of the punch and the die in the rotary punch unit while the radius from the drive rotation axis is small, mutual interference between the flanks due to the edges easily occurs. In order to prevent this, a large clearance angle is required, which is disadvantageous in terms of edge life. Also, increasing the radius is one method, but there is a drawback in that the device is upsized. Therefore, the amount of insertion is generally unavoidable. Therefore, Japanese Patent Publication No. 4-68114
As disclosed in Japanese Patent Publication, when the die is pierced and returned to the original standby position, the die collides with the stopper to give vibration, and the punch scraps are shaken down to the bottom of the die hole to be removed or the die hole escapes. It is known to make the corner larger than the above-mentioned purpose of preventing interference.

[0005]

[Problems to be Solved by the Invention]
According to the method disclosed in Japanese Patent No. 8114, in which vibration is applied to a die to eliminate punching scraps, when the die returns to the standby position, the die collides with a stopper, so that the entire apparatus is overloaded and the accuracy is improved. The above problems are likely to occur, and there is a problem in that vibration and noise are generated. Further, even if the clearance angle is made larger than necessary so that the punching chips can easily come out of the die hole, the punching chips do not always drop below the die hole when the punching chips stick to the tip surface of the punch. In such a case, the punched chips may jump out from the upper surface of the die and enter the pass line surface of the sheet material. Of course, increasing the clearance angle is problematic because it helps prevent chipping of the edges of the punch and die and wear.

The present inventor has observed the behavior of punching chips in detail in order to solve the above-mentioned problems in the rotary punch unit. As a result, in this rotary punch unit, the punching chips are easily stuck to the tip of the punch and come out of the die hole to the pass line side together with the punch. The state immediately after the punching is completed is shown. After punching, the punch causes the trailing edge side a to penetrate deeper into the die hole than when the punching is completed. At this time, the punching waste has a seesaw shape, and the leading edge side portion is projected to the pass line side of the die 2. As a result, punching chips will fall off on the pass line side. The present invention relates to a rotary punch unit, which reliably prevents punching scraps from sticking to the punches and remaining in the die holes in the rotary punch unit, thereby preventing the scraps from entering the punched sheet material on the conveying path line side. The purpose is to provide a unit.

[0007]

Therefore, in the rotary punch unit of the present invention, a projection is provided on the tip surface of the punch so that the punched chips after punching do not stick to the punch and remain in the die hole. This is the feature of the present invention. That is, the rotary punch of the present invention is driven to rotate synchronously in the same direction around the respective axial centers arranged on both sides of the sheet material to be punched, and meshes during the rotation to punch and punch the sheet material to be punched. In the rotary punch unit for a sheet material, which comprises a die and a punch, the punch has a protrusion on its front surface, which is a rotary punch unit.

[0008]

In the rotary punch unit of the present invention, when punching a sheet while the rotating punch and the die mesh with each other, the projection provided on the tip end surface of the punch is used before the punching or during the punching process, the punched sheet is cut into the die hole. It works by pushing it toward the back. As a result, perforation progresses in the punched sheet in a state where tensile stress in the in-plane direction is generated. FIG. 3 is a diagram showing a situation of punching and punching according to the embodiment of the present invention. On the side of the punched sheet material, which becomes the punching waste, the sticking state to the edge of the punch is released by causing slip on the tip surface of the punch each time shearing proceeds, and
While becoming tongue-shaped, it becomes a see-saw shape with the tip of the projection 3 as a fulcrum, and is inclined with its tip portion facing downward, and is separated from both the edge of the punch and the hole surface of the die (A). At the final stage of punching, the punching progresses in a tensionless state, but the sticking action to the punch is extremely weak due to the fact that it is also in the seesaw state (B), and this portion is deeply penetrated at the trailing edge of the punch thereafter. As a result, the punched chips are separated from the flank of the die hole and fall off (C).

[0009]

EXAMPLE An example of the present invention will be described in detail below. FIG. 1 is a cross-sectional view taken along a plane perpendicular to the axis of a rotary shaft of one embodiment, and FIG. 2 is a cross-sectional view taken along a plane including the axis. The punch 1 is attached to one of the two rotary shafts 5 and 6 whose axes are parallel to each other.
The die 2 was attached to the other side. The nominal size of the punch 1 is 6 mm
Is. A hole having a diameter of 2 mm is machined in the center of the tip surface of the punch 1, and a pin 3 having a diameter of 2 mm is attached to the hole so that the protrusion amount from the tip surface of the punch is about 0.5 mm. did. The die 2 has a cup shape as a whole, and a die hole is formed in its edge portion. Both the punch and the die provide proper clearance angles to prevent interference, and gears (not shown) rotate synchronously. With the axes of the punch 1 and the die hole 4 in the left horizontal position in FIG. 1, the sheet is passed through the position shown in FIG. 1, and the two parallel shafts 5 and 6 are synchronized with the rotation direction shown in FIG. Rotate.

Eventually, the punch and the die 2 start to mesh with each other and start punching the sheet. As the punching further progresses, the pin 3 provided at the tip of the punch 1 comes into contact with the sheet, and the portion which becomes the punching waste is pushed into the inside of the die hole 4. Thereafter, as described with reference to FIG. 3, it was confirmed that the punched chips were reliably discharged below the die hole. The (punching scraps 7) pass through a cylindrical die as shown in FIG. 2 and are discharged to the outside of the unit. The above-mentioned perforation was confirmed by a continuous test. There was no malfunction and operation was good. In this embodiment, the pin 3 is attached in order to provide the projection at the tip of the punch, but it may be integrally formed with the punch. Further, although the shape is cylindrical in this time, it may be hemispherical or conical. The whole of the punch excluding the punching edge portion may be formed into a spherical shape or a conical shape.

[0011]

According to the present invention, in a rotary punch unit, punching chips can be reliably discharged below the die hole by a very simple means of providing a projection at the tip of the punch. The usefulness of the punching unit can be increased.

[Brief description of drawings]

FIG. 1 is a cross-sectional view perpendicular to the axis of an embodiment of the present invention.

FIG. 2 is a cross-sectional view of a plane including two axes according to an embodiment of the present invention.

FIG. 3 is a diagram for explaining punching and punching chip discharge of the present invention.

FIG. 4 is a diagram illustrating a situation in which a punching scrap in a conventional rotary punch unit falls off a sheet toward a pass line.

FIG. 5 is a diagram illustrating ejection of punching scraps by a reciprocating punch unit.

[Explanation of symbols]

1 punch, 2 dies, 3 pins, 4 die holes, 5 axis (punch side), 6 axis (die side), 7 punching scrap a punch trailing edge side b punch front edge side

Claims (1)

[Claims] 1. Synchronous rotation drive in the same direction about axes arranged on both sides of the sheet material to be punched,
In a rotary punch unit for a sheet material, which comprises a die and a punch which meshes with each other during the rotation to punch and punch the sheet material to be punched, the punch has a protrusion protruding on a front surface thereof. Punch unit.