JP2000158392A - Punching method of linear motion press - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce vibration at breakthrough time generated often in a press machine, and to reduce thrust-in amount of a slide. SOLUTION: A slide driving source is stopped once in the middle of punching a workpiece, punching is completed by frame energy accumulated in a press frame at the once stopping time, and afterwards, a slide is lowered by actuating the slide driving source. Or the slide driving source is stopped once in the middle of punching the workpiece, and afterwards, the slide is lowered again by raising the slide by a prescribed microscopic distance by actuating the slide driving source.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for punching a direct-acting press, and more particularly to a method for punching a direct-acting press having a large effect of reducing press vibration and noise during punching.

[0002]

2. Description of the Related Art Conventionally, in order to increase the productivity of press working, a crank type press machine having a high slide moving speed has been used. However, direct-acting presses have recently been used in many fields for the purpose of improving the quality of various products and improving the working environment. The direct-acting press can perform the forming process with a slide motion suitable for the shape of the workpiece and the forming purpose by variously controlling the position and speed of the slide. When forming is performed by a direct-acting press, the slide is generally subjected to position servo control using a slide drive unit such as an electric servomotor or a hydraulic cylinder. By performing the position servo control of the slide in this manner, the slide is moved up and down according to a required motion curve of the forming process.

[0003]

In a conventional crank press machine, when punching is performed at a high slide speed, breakthrough occurs after punching. Due to this breakthrough, the slide and the upper die attached to the lower surface of the slide move rapidly downward, so that the amount of the upper die punching into the lower die is large, and the life of the die is shortened, and The service life of the press has been reduced.
Further, the recoil after the plunging causes the upper punch to jump upward, resulting in vibration and noise. As a result, there is a problem that the working environment is deteriorated. In addition, the occurrence rate of defective products increases, and punched scum adheres to the lower surface of the upper die, and the swarf rises due to the vibration caused by breakthrough. Increase the incidence of

The present invention has been made in view of the above-mentioned problems, and can reduce vibration and noise at the time of breakthrough which often occur in the case of a crank type press machine, and can reduce the amount of slide plunge. It is an object of the present invention to provide a method for punching a direct-acting press.

[0005]

In order to achieve the above object, an invention according to claim 1 is a punching method for a direct-acting press in which a slide moves linearly to punch a workpiece. In the method of temporarily stopping the slide drive source during the punching of the workpiece, completing the punching by the energy stored in the press frame during the temporary stop, and then operating the slide drive source to lower the slide I have.

According to the first aspect of the present invention, when the slide is lowered during the punching process, the frame of the press body is distorted due to the reaction force of the load applied to the work (for example, a C-shaped frame whose side frame is C-shaped in side view). Where C
This corresponds to the opening phenomenon of the mold frame), and this distortion is stored as energy in the frame. Then, once the slide drive is stopped at a predetermined slide position, the accumulated frame energy is released to the work, so that the remaining plate thickness of the work being punched is punched. At this time, the slide drive stop position is set so that the accumulated frame energy is substantially equal to the energy required to punch out the remaining plate thickness of the work. Therefore, punching can be performed with the slide drive stopped, and only the energy required for punching is released.
After the punching is completed, the slide descending amount (so-called plunging amount) and the frame vibration become extremely small. Also, when the slide drive source is stopped once and then the slide is lowered again, the vibration of the frame is very small, so the fluctuation of the clearance between the scrap and the lower punch hole is small, For this reason, the punch of the upper die lowers while pushing the scrap into the punch hole of the lower die (that is, the scrap rubs the inner surface of the punch hole). Therefore, when the slide rises from the lower limit position, it is less likely that the scrap is attached to the slide and jumps out of the punch hole, so that the occurrence of the scrap can be reduced, and the surface of the workpiece is not damaged. It is possible to reduce the occurrence of defective products with sticks. As a result, the life of the die and the press machine can be prolonged, and vibration and noise during punching can be reduced to improve the surrounding environment and reduce the occurrence of defective products.

According to a second aspect of the present invention, there is provided a punching method for a direct-acting press in which a slide linearly moves to punch a workpiece, wherein a slide drive source is temporarily stopped during punching of the workpiece. The punching is completed by the energy stored in the press frame during the temporary stop, and then the slide drive source is operated to raise the slide a predetermined minute distance, and then lower the slide again.

According to the second aspect of the present invention, when the slide drive is stopped during the slide descending of the punching process, the frame energy accumulated in the frame is released to the work due to the reaction force of the slide load. The remaining sheet thickness of the workpiece being punched is punched. Therefore, vibration and noise at the time of punching can be reduced. Then, after this, when the slide is going to move sharply further below the punching position due to the breakthrough at the time of the completion of punching, the slide drive is operated to raise the slide by a predetermined minute amount, and then lower again. Therefore, the amount of plunging of the slide after the breakthrough can be reliably reduced. Also, when the slide drive source is once stopped, the slide is raised by a predetermined minute amount, and then lowered again, since the vibration of the frame is very small, the clearance between the scrap and the lower punch hole is reduced. Of the upper die is lowered so as to push the scrap into the punch holes of the lower die. Therefore, when the slide rises from the lower limit position, it is less likely that the scrap is attached to the slide and jumps out of the punch hole, and the occurrence of the scrap can be reduced, and the surface of the workpiece is not damaged. It is possible to reduce the occurrence of defective products with sticks. As a result, the mold life can be further extended, and the surrounding environment can be improved and the occurrence of defective products can be reduced.

According to a third aspect of the present invention, in the punching method for a direct-acting press according to the first or second aspect, the magnitude of the vibration at the time of the past punching process is determined for each punching process in actual operation. Based on the data, when the next stop position of the slide drive source is set, the set position is moved upward by a predetermined distance, and if the current vibration is smaller than the time of the previous punching, the position is moved upward by a predetermined distance from the current time. The method is set such that if the current vibration becomes larger than the time of the previous punching process, the previous position is set.

According to the third aspect of the present invention, the temporary stop position of the slide drive source is set so as to reduce this vibration by referring to vibration data at the time of past punching. That is, when setting the temporary stop position of the slide drive source, if the current vibration is smaller than the previous punching, the slide driving source is further set to a predetermined distance above, and if the current vibration is larger than the previous punching, the previous vibration is set. Position (lower position). This makes it possible to automatically determine the optimal stop position, that is, the slide drive source with low vibration, and stop it at that position while performing the punching work in actual operation. The operating rate can be improved, and vibration and noise at the time of punching can be extremely reduced.

The invention described in claim 4 is the first or second invention.
In the punching method of the direct-acting press described above, the temporary stop position of the slide drive source is experimentally set to an optimum position based on data of the magnitude of vibration at the time of punching by trial hitting.

According to the fourth aspect of the present invention, the temporary stop position of the slide drive source is set so as to reduce the vibration by referring to the data of the magnitude of the vibration at the time of punching by trial hitting. That is, the temporary stop position of the slide drive source is set to move upward by a predetermined distance from the lower limit position, and the magnitude of vibration at each punching is measured. Based on the data of the magnitude of the vibration, the slide position when the vibration is the smallest is set as the slide drive source temporary stop position. This makes it possible to experimentally determine the optimal, that is, the slide drive source temporary stop position that minimizes the vibration, so that the vibration and noise at the time of punching due to the temporary stop of the slide drive source can be greatly reduced.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a method for punching a direct-acting press according to the present invention will be described below in detail with reference to the drawings. FIG. 1 is a side view of a main part of a hydraulic press as a preferred example of a direct acting press according to the present embodiment. In FIG. 1, a frame (hereinafter, referred to as a C frame) 7 having a C-shape in a side view is disposed on the left and right side surfaces of the main body of the direct-acting press 1. The bolster 3 is arranged below the C frame 7. A slide 2 is disposed at an upper portion of the C frame 7 and at a position facing the bolster 3 so as to be vertically movable. As an example of a means for driving the slide 2, A hydraulic cylinder 4 is provided. The hydraulic cylinder 4 is mounted on a manifold block 14 together with a servo valve (hereinafter, referred to as a servo valve) 13 capable of variably controlling the speed, a solenoid valve 21 for the pilot hydraulic pressure of the servo valve 13, and the like. It has an integrated structure in which piping connecting the spaces is eliminated by the manifold block 14.

A lower die 5 is mounted on the upper surface of the bolster 3, and an upper die 6 is mounted on the lower surface of the slide 2, and a workpiece 10 is carried into a predetermined position on the upper surface of the lower die 5. It has become so. Then, as the slide 2 moves up and down, the workpiece 10 is punched between the lower die 5 and the upper die 6.

In the vicinity of the opening of the C frame 7,
An auxiliary frame 8 having substantially the same shape as the opening is provided. The lower end of this auxiliary frame 8 is moved by a pin 8a so that it can be displaced only in the vertical direction.
It is attached to the side of the frame 7. Further, between the upper end of the auxiliary frame 8 and the rear side of the slide 2, a slide position detection sensor 11 composed of, for example, a linear type linear sensor is mounted.

The slide position detecting sensor 11 has a sensor rod 11a whose axis is parallel to the moving direction of the slide 2 and is supported at the rear of the slide 2, and is inserted into the sensor rod 11a. The auxiliary frame 8
And a sensor head 11b attached to the upper end side. Then, as the slide 2 moves up and down, the sensor rod 11a moves up and down with respect to the sensor head 11b, whereby the position of the slide 2 is raised from the upper surface of the bolster 3 by the position detecting unit inside the sensor head 11b. It is to be detected as. The position signal of the slide 2 detected by the slide position detection sensor 11 is input to a controller 15 described later, and the controller 15 drives the hydraulic cylinder 4 based on the position signal to determine the position and speed of the slide 2. Control is performed so as to follow a predetermined motion curve.

A plurality of frame distortion sensors 12 are attached to the outer surface of the opening of the C frame 7 in close contact with each other, and the distortion signal is input to a controller 15.

FIG. 2 is an explanatory view of a slide motion by a punching method of a direct acting press according to the present invention. The slide 2 descends from the upper limit position U0 to a deceleration position U1 just before touching the surface of the workpiece 10 at a predetermined high descending speed. Next, it descends from the deceleration position U1 at a predetermined low descending speed, the lower surface of the upper die 6 touches the workpiece 10 on the upper surface of the lower die 5, and descends while punching the workpiece 10. Then, the slide drive source temporarily descends to the stop position P and stops for a predetermined time t0.

Thereafter, the press work is lowered to a preset lower limit position U2 at a predetermined speed to complete the press working. Then, from this lower limit position U2, a preset low speed ascending position U3
Up to the predetermined low speed, and
Until it stops at a predetermined high speed, stops for a predetermined time (including time 0), and completes one cycle of machining. In the actual forming operation, this one-cycle processing is repeatedly performed.

FIG. 3 is a block diagram showing a control configuration for realizing the punching method according to the present invention. This control configuration block diagram is a hardware configuration for controlling the slide 2 along the slide motion curve in FIG. 2 described above, and the components will be described. Slide position detection sensor 11
Detects the vertical position of the slide with respect to the bolster 3 as described above, and the detection signal is
5 is input.

The above-described frame distortion sensor 12 detects the value of distortion from the amount of vertical expansion of the C frame 7 due to the reaction force of the load generated during press working, and generates a distortion signal corresponding to the magnitude of the detected distortion. Is output to the controller 15. In advance,
In the corresponding press machine, the relationship between the load applied to the slide 2 and the value measured by the frame distortion sensor 12 due to this load is measured, and the relationship between the measured load applied to the slide 2 and this frame distortion (data table or (E.g., relational expressions) are stored in the memory 18 inside the controller 15. The distortion signal input to the controller 15 is converted into a load value applied to the slide 2 based on the relationship between the stored load and the frame distortion.

The motion setting means 16 sets each position data and speed data for defining the above-mentioned slide motion, and includes an upper limit position U0 and a deceleration position U1.
, A slide drive source, a stop position P, a lower limit position U2, a low speed ascending position U3, a high speed descent speed, a low speed descent speed, a low speed ascent speed, a high speed ascent speed, and the like. .

These setting data are input to the controller 15. The motion setting means 16 may be constituted by a transceiver for inputting each set value data of the motion curve by communication or the like from another control device constituted by a host computer or the like. These set values are stored in a predetermined memory 18 in the controller 15 as motion data corresponding to each motion curve.
Is stored.

The controller 15 is mainly composed of a computer device such as a microcomputer, for example, and has a non-volatile readable / writable memory 18 having a predetermined capacity therein. The input setting data and a data table or a relational expression representing a relationship between the measured frame strain value and the load are stored in the memory 18. The controller 15 controls the slide position detection sensor 1 during the punching process.
1 and a distortion signal from the frame distortion sensor 12, perform predetermined processing described later, and perform a slide 2 with a slide motion according to the set data in the memory 18.
A speed command is output to a slide drive unit 19 described later so that the.

The slide driving means 19 drives the slide actuator 20 based on the speed command. The slide drive means 19 is constituted by the servo valve 13 when the slide actuator 20 is the hydraulic cylinder 4, and by a servo amplifier when the slide actuator 20 is an electric motor and a ball screw (not shown).

When the servo valve 13 is used as an example of the slide driving means 19, the flow rate and direction of the hydraulic oil discharged from a hydraulic pump (not shown) are controlled based on the speed command from the controller 15. Then, the expansion / contraction speed and direction of the hydraulic cylinder 4 are controlled to lower, raise, and stop the slide 2.

The display 17 displays each set value of motion data, press operation information, and the like based on a display command from the controller 15.
It can be configured by a combination of a graphic display such as L and a character display including an LED display element and the like.

FIG. 4 is a control flowchart example showing the punching method according to the first embodiment. A control processing procedure in the present embodiment will be described with reference to FIGS. Here, each processing step number is indicated by adding S, and the same applies to the subsequent flowcharts. First S
In step 1, motion data corresponding to the workpiece and the mold are set. Then, in step S2, before the automatic press operation, the slide drive source temporary stop position P and the reference peak distortion value H0 are initialized to predetermined values. I do. The slide drive source temporary stop position P is set as an initial value at which a breakthrough always occurs. For example, a position P1 near the lower limit position U2 is set as shown in FIG. The reference peak strain value H0 is a parameter for determining whether or not the press vibration at the time of breakthrough has become small, and a large value is set as an initial value.

Thereafter, in S3, the press operation is started,
Slide 2 based on the set motion data
Is automatically driven from the upper limit position U0 to the deceleration position U1. Thereby, the slide 2 descends from the upper limit position U0 at a predetermined high descending speed and reaches the deceleration position U1. Next, S
At 4, the controller 15 lowers the slide 2 from the deceleration position U1 to the slide drive source temporarily stopping position P at a predetermined low descent speed, and at the same time, collects distortion data from the frame distortion sensor 12. At this time, when the slide 2 touches the workpiece 10 and reaches the slide drive source once at the stop position P during the punching of the workpiece 10, the time t0 is reached in S5.
During this time, the drive of the slide drive means 19 is temporarily stopped. While the slide 2 is stopped, the frame strain energy accumulated in the frame is released to the workpiece 10 due to the reaction force of the slide load.

At S5, the slide 2 temporarily stopped for the time t0 is lowered at S6 at a predetermined speed to the lower limit position U2 by the slide driving means 19, and then the low-speed ascending position U3 is reached.
To the upper limit position U0, stop at a high speed, and complete one cycle machining.

In step S7, a peak distortion value H of the frame vibration at the time of breakthrough is determined from the frame distortion data collected during the current press working, and this peak distortion value H is compared with the reference peak distortion value H0. I do. Next, in S8,
It is determined whether the peak distortion value H is equal to or less than the reference peak distortion value H0,
If the peak distortion value H is equal to or less than the reference peak distortion value H0, the process proceeds to S9.
Then, the slide driving source temporary stop position P is reset to a position shifted upward by a predetermined minute distance ΔP (positive value) from the current set value. Here, it is assumed that the slide position data increases as going upward. Then S
In step 10, the reference peak distortion value H0 is calculated as the peak distortion value H obtained above.
Is set again, the process returns to S3, and thereafter the process is repeated.

If the peak distortion value H is larger than the reference peak distortion value H0 in S8, the slide drive source temporarily stopped position P is shifted downward by a predetermined minute distance ΔP from the current set value in S11. (That is, the previous position), the process returns to S3, and the process is repeated thereafter.

As described above, since the slide drive is temporarily stopped at the slide drive source temporary stop position P, the frame distortion energy accumulated in the frame is released at the slide drive source temporary stop position P, thereby The remaining thickness of the workpiece 10 during the cutting is punched. At this time,
While the slide drive source temporary stop position P is near the lower end of the workpiece 10, the frame distortion energy is larger than the minimum energy necessary for punching the remaining plate thickness. The extra frame distortion energy will cause significant vibration and noise of the frame. Then, as shown in FIG. 5, the slide drive source temporary stop position P is updated each time the automatic operation is performed, and the frame vibration of the press converges to a small position. At this converged position, the accumulated frame strain energy is the minimum energy necessary to punch out the remaining thickness of the workpiece 10, so that
When the punching is completed, the extra frame energy is extremely small. Moreover, at this time, since the slide drive is stopped, the amount of slide plunge is smaller than in the past, and vibration and noise during breakthrough are reduced. Therefore, the life of the mold can be prolonged, and the environment for the press operation can be improved.

Next, a second embodiment of the present invention will be described with reference to FIGS. 6 and 7 showing a method of punching a direct-acting press according to the present invention. FIG. 6 is an explanatory diagram of the slide motion in the present embodiment, similarly to FIG. The same reference numerals are given to the same components as those of the respective parts of the slide motion described above with reference to FIG. 2, and description thereof will be omitted.
Further, only portions different from the motion in the first embodiment will be described below.

When the slide 2 temporarily drops to the slide drive source stop position P, it stops for a predetermined time t0, and thereafter,
The slide 2 is raised by a minute amount ΔQ at a predetermined speed to a preset raising position Q. Next, it descends at a predetermined speed to a preset lower limit position U2 at a predetermined speed to end the press working, rises from this lower limit position U2 via a predetermined low speed ascent position U3 to an upper limit position U0, and stops. After stopping for a predetermined time (including time 0), one cycle machining is completed.

Next, FIG. 7 is an example of a control flowchart showing a punching method according to the second embodiment, and a control processing procedure in the present embodiment will be described with reference to FIG. S21
Then, motion data corresponding to the workpiece and the mold are set, and then, in S22, before the automatic press operation, the slide drive source temporary stop position P and the reference peak distortion value H0 are initialized to predetermined values. . The slide drive source temporary stop position P is set as an initial value at which a breakthrough always occurs. For example, a position P1 near the lower limit position U2 is set as shown in FIG. The reference peak distortion value H0 is a parameter for determining whether or not press vibration at the time of occurrence of breakthrough has decreased, and a larger value is set as an initial value.

Thereafter, in S23, the press operation is started, and the slide actuator 20 is driven such that the slide 2 is automatically operated from the upper limit position U0 to the deceleration position U1 based on the set motion data.
Thereby, the slide 2 descends from the upper limit position U0 at a predetermined high descending speed and reaches the deceleration position U1. Next, in S24, the controller 15 moves the slide 2 to the deceleration position U1.
At the same time, the slide drive source is temporarily lowered to the stop position P at a predetermined low descent speed, and at the same time, distortion data is collected from the frame distortion sensor. At this time, the slide 2 touches the workpiece 10, and during the punching of the workpiece 10,
When the slide drive source once reaches the stop position P, the drive of the slide drive means 19 is temporarily stopped for a time t0 in S25. While the slide 2 is stopped, the frame distortion energy accumulated in the frame is released to the workpiece 10 due to the reaction force of the slide load.

In step S25, the slide 2 temporarily stopped during the time t0 is raised by a small amount ΔQ to a predetermined raising position Q set in advance by the slide driving means 19 in step S26. Then, in S27, the slide driving unit 19
After lowering the slide 2 to the lower limit position U2 at a predetermined speed, the slide 2 is raised to the low speed ascending position U3 at the low speed ascending speed, further raised to the upper limit position U0 at the high speed ascending speed and stopped, thereby completing one cycle machining. .

In step S28, a peak distortion value H of the frame vibration at the time of breakthrough is obtained from the frame distortion data collected during the current press working.
And the reference peak distortion value H0. Next, in S29,
It is determined whether the peak distortion value H is equal to or less than the reference peak distortion value H0,
If the peak distortion value H is equal to or less than the reference peak distortion value H0, the process proceeds to S30.
Then, the slide driving source temporary stop position P is reset to a position shifted upward by a predetermined minute distance ΔP (positive value) from the current set value. Here, it is assumed that the slide position data increases as going upward. Then S
At 31, the reference peak distortion value H0 is calculated as the peak distortion value H obtained above.
Is set again, the process returns to S23, and the process is repeated thereafter.

When the peak distortion value H is larger than the reference peak distortion value H0 in S29, the slide drive source temporarily stopped position P is set to a predetermined minute distance ΔP from the current set value in S32.
Is reset to a position shifted downward only (that is, the previous position), the process returns to S23, and the process is repeated thereafter.

As described above, since the slide drive is temporarily stopped at the slide drive source temporary stop position P, the frame distortion energy accumulated in the frame is released at the slide drive source temporary stop position P. The remaining thickness of the workpiece 10 during the cutting is punched. At this time,
While the slide drive source temporary stop position P is near the lower end of the workpiece 10, the frame distortion energy is larger than the minimum energy necessary for punching the remaining plate thickness. The extra frame distortion energy will cause significant vibration and noise of the frame. And like the previous embodiment,
As shown in FIG. 5, the slide drive source temporary stop position P is updated each time the automatic operation is performed, and the frame vibration of the press converges to a small position.

At the converged position, the accumulated frame strain energy is the minimum energy necessary for punching the remaining thickness of the workpiece 10, so that when the punching is completed, extra frame energy is generated. Is extremely small. Moreover, when the slide is going to move sharply further below the punching position due to the breakthrough at the time of the completion of the punching, the slide driving means 19 is operated to raise the slide 2 to the preset rising position Q. The slide descent (the amount of plunge) after breakthrough is greatly reduced, and vibration and noise during breakthrough are reduced. Therefore, the life of the mold can be prolonged, and the environment for the press operation can be improved.

In the above description of the first and second embodiments, the slide drive source is temporarily set at the stop position P by a small distance ΔP by automatic press operation. The method of setting the temporary stop position P is not limited to this. That is, for example, when punching is performed while collecting slide vibration data by trial hitting, the slide drive source is temporarily shifted from the stop position P by a predetermined minute distance to obtain an optimum position where the slide vibration is minimized. Alternatively, this optimum position may be set as the slide drive source temporary stop position P.

As an embodiment of the present invention, an example in which a hydraulic cylinder is used for a slide actuator of a direct acting press has been described. Usually, when hydraulic oil is used as a slide driving means of a press, the hydraulic oil is driven by pressure. Since the volume compression is large compared to steel and other mechanical structural materials,
Large breakthrough during punching. For this reason, about 50% of the pressurizing capacity of the hydraulic direct acting press is set as the maximum value of the punching load. However, according to the method of the punching process using the energy stored in the frame according to the present invention, the energy of the compressed hydraulic oil in the hydraulic cylinder can be released together with the energy stored in the frame and utilized for the punching process. In addition, the occurrence of vibration due to breakthrough is very small. In this way, the workpiece can be punched by applying a punching load up to the maximum pressing ability of the hydraulic direct acting press. Furthermore, loosening of the piping connection portion of the hydraulic linear motion press machine and the assembly portion of the hydraulic device due to vibration and impact does not occur, thereby reducing oil leakage, device failure, and the like.

Even when an electric motor and a ball screw are used for the slide actuator of the direct-acting press, the punching with the maximum load of the direct-acting press can be performed by the punching method using the energy stored in the frame according to the present invention. Processing becomes possible, and the processing capability of the same press can be used to the maximum.

Further, as in the case of the conventional crank type press machine, the scrap of the workpiece due to the scrap lifting phenomenon that occurs after the punching of small parts at high speed operation damages the surface of the workpiece, or causes punching. Since punching can be performed in a state where breakage hardly occurs and breakthrough hardly occurs, it is possible to eliminate the problem of scrap removal.

In the method of temporarily stopping the slide drive source during the punching process according to the present invention and utilizing the strain energy accumulated in the press frame for the remaining punching, in order to increase the production speed, the punching is performed. Since the high-speed descent speed, the low-speed descent speed, and the high-speed descent speed other than the descent speed of the slide being processed are increased as much as possible and the stroke length of the slide can be reduced, the production speed is not significantly reduced.

[Brief description of the drawings]

FIG. 1 is a side view of a main part of a direct acting press according to the present invention.

FIG. 2 is an explanatory diagram of a slide motion of the punching method according to the first embodiment.

FIG. 3 shows a block diagram of a control configuration for realizing a punching method.

FIG. 4 shows an example of a control flowchart illustrating a punching method according to the first embodiment.

FIG. 5 is an explanatory diagram of a slide drive source temporarily stopped position.

FIG. 6 is an explanatory diagram of a slide motion in a punching method according to a second embodiment.

FIG. 7 shows an example of a control flowchart illustrating a punching method according to the second embodiment.

[Explanation of symbols]

1 ... linear press, 2 ... slide, 3 ... bolster, 4 ...
Hydraulic cylinder, 5 ... lower mold, 6 ... upper mold, 7 ... C frame,
8 ... Auxiliary frame, 8a ... Pin, 10 ... Workpiece, 11
... Slide position detection sensor, 11a ... Sensor rod, 1
1b: Sensor head, 12: Frame distortion sensor, 13:
Servo valve, 14: manifold block, 15: controller, 16: motion setting means, 17: display, 18
... memory, 19 ... slide drive means, 20 ... slide actuator, 21 ... solenoid valve for pilot hydraulic pressure.

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Hiroshi Shirahata 107 Oshiga Yoga, Suwa-shi, Nagano Taiyo Kogyo Co., Ltd. F-term (reference) 3C060 BA01 BE09 BG11 BG13

Claims (4)

[Claims] In a punching method of a direct-acting press in which a slide moves linearly to punch a workpiece, a slide driving source is temporarily stopped during punching of the workpiece, and the press frame is temporarily stopped. A punching method for a direct-acting press, characterized in that the punching is completed by the energy accumulated in the slide, and then the slide is driven by operating a slide drive source. 2. A punching method for a direct-acting press in which a slide moves linearly to punch a workpiece, wherein a slide drive source is temporarily stopped during punching of the workpiece, and the press frame is temporarily stopped. A punching method for a direct-acting press, characterized in that the punching is completed by the energy accumulated in the slide, the slide drive source is operated, the slide is raised by a predetermined minute distance, and then lowered again. 3. The punching method for a direct-acting press according to claim 1 or 2, wherein, for each punching operation in actual operation, a next-time punching operation is performed based on data of the magnitude of vibration in the past punching operation. When setting the temporary stop position of the slide drive source, move the set position upward by a predetermined distance, and if the current vibration becomes smaller than the time of the previous punching operation, set the position to be a predetermined distance above the current time. A punching method for a direct-acting press, characterized in that if the current vibration becomes larger than before, the previous position is set. 4. The punching method for a linear motion press according to claim 1, wherein the temporary stop position of the slide drive source is experimentally optimized based on data of vibration magnitude at the time of punching by trial hitting. A punching method for a direct-acting press, characterized in that it is set at a position.