JPH01103298A - Edge pressure controller for puncher - Google Patents

Abstract

PURPOSE: To alway perform a good punching operation by arranging a number of thickness variable elements whose thicknesses are controlled in response to the cutting edge pressures detected by a pressure sensor so that the cutting edge pressures of respective parts can have proper values, in a good top-to- bottom correspondence. CONSTITUTION: Proper cutting edge pressures at respective positions are set in a computer, and respective set values and measured values detected by a pressure detecting sensor 32 are compared to each other. When a measured value is larger than a set value at a certain position, or when the cutting edge pressure is higher, a cutting edge pressure control device generates a command for voltage drop in response to the difference between the set value and the measured value to lower output voltage of a variable power supply through a D/A converter 40, and to thin the thickness of a thickness variable element 33 at this position by an amount equivalent to the voltage drop. When the thickness of the thickness variable element 33 becomes thinner, the cutting edge pressure at the time of the next punching will be reduced and paper sheets 20 can be excellently punched by a cutting edge 11 constantly.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a device for controlling the blade pressure of a cutting blade in a machine that punches out a sheet material such as paper into a desired shape.

[Prior art and its problems]

For example, when punching paper into the expanded shape of a paper box in order to make a paper box, a punching machine as shown in Figure 8 is usually used. The blade 11 is supported by a wooden cutting blade support panel 12. The cutting blade 11 penetrates the cutting blade support panel 12 in the thickness direction and is attached so that its back surface is exposed on the back surface of the cutting blade support panel 12. Cutting blade support panel 1
2 is held in the chase 15 by the tightening plate 13 and the push screw 14, and in this state is attached to the upper window atS of the press device via the unevenness removing plate 16 and the restraining plate 17.

Further, reference numeral 21 denotes a hard metal face plate on which the paper 20 is placed, and this face plate 21 is attached to a lower surface plate 23 of the press device via a face plate rib 22 made of metal or hard resin.

Note that 24 is a gripper bar for gripping the paper 20, and 25 is a rubber member for extracting the punched paper from the cutting blade 11.

This type of punching machine has a cutting machine 20 mounted on a hard face plate 21.
Since punching is performed by pressing the cutting blade 11 on the
If the cutting edge of the cutting blade 11 is not adjusted so that it bites into the paper 20 evenly over the entire circumference, there will be parts that can be cut and parts that cannot be cut (unevenness in the degree of cutting), and complete punching will not be possible. .

For this reason, with this type of punching machine, it is necessary to perform an operation called "unevenness removal" before starting the punching operation. This work is done to adjust the sharpness of the cutting blade to be even across all parts, and is carried out as follows.

First, make a trial cut, check the cutting condition all around, and if there are parts that are not cut enough, - Chase 1
5. Remove the cutting blade support panel 12 from the upper surface plate 18, paste paper or cellophane tape, etc. on the unevenness removing plate 16 at the positions corresponding to the areas where the cutting condition is poor (this is called patchwork), and then re-assemble. Cutting blade support panel 1
2 to the upper surface plate 18 and make a trial cut.If a piece of tape or cellophane tape, etc. is interposed between the unevenness removing temporary 16 and the restraining temporary 17 as described above, the cutting edge will be cut by the thickness during punching. Since it is pressed strongly, the cutting quality of that part is improved. If some parts still cannot be cut sufficiently even after this trial cutting, make adjustments again using patchwork.

After performing such unevenness removal work, the actual punching work begins, but this work is done manually, which not only takes time and money, but also requires considerable skill. There is.

In addition, even if you begin the punching process after removing unevenness, if the number of punches increases, the cutting may become uneven in the middle, and in that case, you will have to stop the machine and remove the unevenness. It disappears.

Therefore, there is a problem that the operating rate of the machine decreases.

[Means for solving problems and their effects]

SUMMARY OF THE INVENTION In view of the problems of the prior art as described above, an object of the present invention is to provide a blade pressure control device for a punching machine that can omit the work of removing unevenness.

Therefore, the present invention provides a punching machine in which a cutting blade supported in a punching shape by a cutting blade support panel is pressed against a sheet material such as paper set on a hard face plate, and the sheet material is punched into a desired shape. In order to be able to control the sharpness of each part of the cutting blade to be approximately uniform, a punch is provided at least at a position corresponding to the cutting blade on the back side of the cutting blade support panel, the back side of the face plate, or both. A large number of pressure sensors that detect the blade pressure applied to the cutting edge and variable thickness elements that can control the thickness of the blade from the outside are arranged vertically in correspondence with each other, and the blade pressure detected by each pressure sensor is The present invention is characterized in that the thickness of the corresponding variable thickness element is controlled in accordance with the pressure so that the blade pressure of each part becomes an appropriate value.

When the blade pressure applied to the cutting edge during punching is low, the cutting quality tends to deteriorate, and when it is high, the cutting quality improves, but the cutting blade tends to wear more severely. In other words, there is an appropriate blade pressure to keep the cutting tool ◆ in good condition.

Therefore, the present invention detects the blade pressure at each part of the cutting blade, and when the blade pressure is not appropriate, the blade pressure is adjusted by controlling the thickness of a variable thickness element placed at a position corresponding to the pressure sensor. This allows adjustment to an appropriate value. In other words, the present invention automatically performs conventional patchwork using variable thickness elements.

Although it is preferable to use a piezoelectric element or a magnetostrictive element as the variable thickness element, it is also conceivable to use other elements such as those whose thickness is adjusted by a combination of a small motor and a screw.

〔Example〕

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

1 and 2 show one embodiment of the invention.

This device includes a cutting blade support panel 12 as shown in FIG.
An element array plate 31 is provided on the back side of the upper surface plate 18, that is, on the lower surface of the upper surface plate 18. This element array plate 31 has a large number of holes opening on the lower surface arranged vertically and horizontally, and a pressure sensor 32 and a variable thickness element 33 are housed in a stacked state in each hole. The pressure sensor 32 converts pressure into an electrical signal, and typically uses a piezoelectric element. Further, as the variable thickness element 33, a piezoelectric element whose dimensions (thickness) changes depending on the applied voltage is used here. The rest of the configuration in FIG. 1 is the same as the conventional example in FIG. 8, except that the unevenness removing plate 16
One or both of the and restraint +Ii, 17 can be omitted.

FIG. 2 is a block diagram of a circuit that controls the variable thickness element 33 according to the pressure detected by the pressure sensor 32. 34
3 is a peak hold circuit corresponding to each pressure sensor 32;
5 is a multiplexer that sequentially reads out the values of the peak hold circuit 34; 36 is an amplifier; 37 is an A/D converter; 38 is a computer; 39 is a top dead center detector on the lower surface plate 23;
0 is a D/A converter, and 41 is a variable power supply that changes the voltage applied to the variable thickness element 33.

The computer 38 performs processing as shown in FIG.

First, when the control system starts, the first step clears all the peak hold circuits 34.Then, the presence or absence of a signal from the top dead center detector 39 is checked, and the second step moves the lower surface plate 23 to the top dead center. Decide whether or not it has arrived. If the top dead center is not reached, repeat the second step. Lower surface plate 2
3 reaches the top dead center is the moment of punching, and at this time the blade pressure applied to the cutting blade 11 is at its maximum. Therefore, when the lower surface plate 23 reaches the top dead center, the peak hold circuit 34 stores the maximum value of the blade pressure of each part. computer 3
When 8 determines that the lower surface plate 23 has reached the top dead center, it operates the multiplexer 35 in the next third step, and sequentially transmits the blade pressure values Dn stored in each peak hold circuit 34 to the amplifiers 36 and A. /D converter 37.

The appropriate blade pressure Cn for each position is set in advance in the computer 38, and in the next fourth step, the set value Cn is set.
and the measured value Dn. When the measured value is larger than the set value at a certain position, that is, when the blade pressure is high, the fifth
step, issues a voltage drop command according to the difference, and
Lowering the output voltage of the variable power supply 41 through the A converter 40,
The thickness of the variable thickness element-33 at that position is reduced by that amount (
As the thickness of the variable thickness element 33 becomes thinner,
The blade pressure will decrease during the next punching. Furthermore, when the measured value is smaller than the set value at a certain position, that is, when the blade pressure is low, in the sixth step, a voltage increase command is issued according to the difference, and the variable power supply 41 is sent through the D/A converter 40.
The output voltage is increased, and the thickness of the variable element 33 at that position is increased by that amount. As the thickness of the variable thickness element 33 increases, the blade pressure increases accordingly during the next punching. The sixth step is also executed when the measured value and the set value are the same, but since the difference is 0, the output voltage of the variable power supply 41 does not change.When the process of 0 or more is completed, the process returns to the first step and prepares for the next punching. .

By doing so, the blade pressure at each part is adjusted to an appropriate value each time punching is performed, so that good punching can always be performed. Of course, the process shown in FIG. 3 does not have to be performed every time, and may be performed every few times by counting the number of punches.

FIG. 4 shows another embodiment of the present invention. This device has a face plate holder 22 on the back side of a face plate 21, in which a large number of holes opening on the upper surface are arranged vertically and horizontally, and a pressure sensor 32 and a thickness The variable elements 33 are stored in a stacked state. Even in this case, the same control as in the embodiment described above can be performed.

FIG. 5 shows still another embodiment of the present invention. In this device, a pressure sensor 32 is installed in a hole provided in a face plate support 22, and a pressure sensor 32 is installed in a hole provided in an element array plate 31 attached to an upper surface plate 18. A variable element 33 is installed. The pressure sensor 32 and the variable thickness element 33 are arranged to face each other on a one-to-one basis. In this way, the pressure sensor and the variable thickness element can be installed separately in the upper and lower parts.

In addition, in the above embodiment, the pressure sensor and the variable thickness element were arranged almost entirely on the back side of the cutting blade support panel, the back side of the face plate, or both, but the pressure sensor and the variable thickness element Of course, they may be arranged only at the position corresponding to the cutting edge.

Furthermore, although a piezoelectric element was used as the variable thickness element in the above embodiment, any variable thickness element may be used as long as the thickness of the variable element itself can be controlled from the outside.

For example, as shown in FIG. 6, a male screw 51 and a female screw 52 are screwed together, the female screw 52 is prevented from rotating, and the male screw 51 is rotated by a small motor 53 to move it up and down, or as shown in FIG. It is conceivable that a male screw 57 is screwed into a block 56 placed on an inclined table 55, and the male screw 57 is rotated by a small motor 58 to move the block 56 in the inclined direction and move it up and down. . In the case of Fig. 7, it is necessary to connect the motor shaft and the male screw with a universal bolt.

〔Effect of the invention〕

As explained above, according to the present invention, the blade pressure at each part of the cutting blade is detected, and if the blade pressure is not appropriate, the thickness of the variable thickness element is controlled to adjust the blade pressure to an appropriate value. Since it is adjustable, it is possible to always perform a good punching process without having to perform unevenness removal work like in the past, which has a great effect on improving the productivity of punching processes and reducing costs.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view of the punching machine part of a blade pressure control device according to an embodiment of the present invention, Fig. 2 is a block diagram of a circuit configuring the device, and Fig. 3 is a processing of a computer in the device. Flowchart showing the contents, FIGS. 4 and 5 are cross-sectional views showing other embodiments of the present invention, and FIGS. 6 and 7 are cross-sectional views showing examples of variable thickness elements used in the present invention, respectively. , FIG. 8 is a sectional view showing a conventional punching machine. 11~cutting blade, 12~cutting blade support panel, 18~lower surface plate,
20 - paper, 21 - face plate, 22 - face plate holder, 23 - lower surface plate, 31 - element array plate, 32 - pressure sensor, 33 - variable thickness element, 34 - peak hold circuit, 35 - multiplexer, 38 - Computer, 41 ~ variable power supply.

Claims (1)

[Claims] This is a blade pressure control device for a punching machine that presses a cutting blade supported in a punching shape by a cutting blade support panel against a sheet material such as paper set on a hard face plate to punch out the sheet material into a desired shape. A pressure sensor for detecting the blade pressure applied to the cutting blade during punching is provided on the back side of the cutting blade support panel, the back side of the face plate, or both, at least at a position corresponding to the cutting blade, and a pressure sensor that detects the blade pressure applied to the cutting blade during punching, and a pressure sensor that detects the thickness of the cutting blade from the outside. A large number of variable thickness elements that can control the thickness are arranged vertically in correspondence, and the blade pressure in each part is adjusted to an appropriate value according to the blade pressure detected by each pressure sensor. A blade pressure control device for a punching machine, characterized in that the thickness of a variable thickness element is controlled.