JP3315511B2 - Control method of punch press machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for controlling a punch press having a punch and a die for punching a work, and a stripper for holding the work when the punch is raised.

[0002]

2. Description of the Related Art Conventionally, in a punch press machine such as a turret punch press, a work on a die is punched by a punch and a die while a work on the die is pressed by a stripper descending with the punch. Has become.

Incidentally, in such a punch press machine, the punch stroke is controlled in accordance with a punching load, sheet thickness information and the like in order to reduce punch noise and shorten processing time. Various proposals have been made as shown in the following. Patent Document 1: Japanese Patent Laid-Open Publication No. 1-148499 In order to automatically generate a low-vibration, low-noise, and high-efficiency machining stroke pattern from a punching load calculated from a material, a thickness, and a punching circumference of a workpiece and thickness information. Press machine stroke control method. SUMMARY OF THE INVENTION A control method of a hydraulic press driving device of a punch press machine for controlling a press with a minimum necessary stroke based on information of a plate thickness and a shear angle to increase productivity. SUMMARY OF THE INVENTION A predetermined item is calculated from a plate thickness and a material, and the calculation result is transferred to a digital servo controller. The controller issues a drive command according to a punch program generated from the data to a punch drive actuator. Punch press control device to output.

[0004]

However, the structures disclosed in the above publications do not have a structure in which the pressure control and the stroke control of the stripper can be performed only by controlling the stroke of the punch. The problem of indentation generated on the work surface by the stripper cannot be solved.In addition, if the stripper is integrated with the punch via a disc spring, the reduction of punch noise is limited, There is a problem that there is a limit in shortening the processing time because the punch is vertically moved in conjunction with the vertical movement of the punch.

Further, in the above-mentioned publications, the vertical movement of the ram connected to the punch is controlled by the hydraulic pressure from a single hydraulic source regardless of the magnitude of the punching load. There is also a problem that efficient machining cannot be performed because a hydraulic source is required.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and a punch capable of performing low-noise machining, achieving high productivity, and having no indentation of a stripper on a work surface. An object of the present invention is to provide a method for controlling a press machine. Another object of the present invention is to provide a method for controlling a punch press that can perform highly efficient processing.

[0007]

In order to achieve the above object, a method for controlling a punch press according to the present invention is directed to a punch having a punch and a die for punching a work, and a stripper for holding the work when the punch is raised. In the press machine, work thickness and material information,
Punching load information of the punch calculated from material information,
From the preset processing speed mode information, the pressure of the stripper and the stroke pattern of the stripper and the punch are respectively calculated, and the stripper and the punch are controlled based on the calculation result. Things.

Here, it is preferable that the processing speed mode can be set to any one of a low speed mode, a normal mode and a high speed mode. In this case, it is preferable that the stripper be held at a position at a minute distance from the workpiece in the high-speed mode during processing, and that the stripper be in contact with the workpiece in the low-speed mode and the normal mode during processing.

In the present invention, there is further provided a prefill valve for switching the hydraulic pressure supplied to the cylinder chamber of the punch driving cylinder to be supplied from the tank when the punch is operated at a low load and at a high speed. It is preferable to control the valve so that the switching operation is performed when the punching load of the punch is equal to or more than the specified value, and the switching operation is not performed when the punching load is less than the specified value.

In this case, when the prefill valve is switched, or when the processing speed mode is in the low speed mode even when the prefill valve is not switched, the punch stroke pattern is determined by changing the punch position with respect to time by a broken line. It is good to set it so that it changes in the shape.
Further, when the prefill valve is not switched and the processing speed mode is the normal mode or the high-speed mode, the punch stroke pattern is preferably set so that the punch position with respect to time changes in a sine wave shape. .

In the present invention, a punch driving cylinder,
Preferably, hydraulic pressure is supplied to the stripper driving cylinder and the spool of the prefill valve via respective hydraulic servo valves, and these hydraulic servo valves are controlled by signals from respective servo amplifiers.

[0012]

According to the present invention, information on the thickness and the material of the work, information on the punching load of the punch calculated from the information on the thickness and the material, and the predetermined processing such as a low speed mode, a normal mode and a high speed mode. The pressure of the stripper and the stroke patterns of the stripper and the punch are calculated from the speed mode information, and the stripper and the punch are controlled based on the calculation results.
In this manner, the acceleration of the stripper at the time of punching the work can be limited to a predetermined value, thereby reducing noise at the time of punching,
By changing the pressure of the stripper, it is possible to prevent the formation of dents on the surface of the work, and to set the timing for the stripper to come in contact with and release from the work, and to perform processing without bringing the stripper into contact with the work. Setting makes it possible to improve productivity.

Here, when the machining speed mode is set to the high speed mode, the stripper is held at a position separated by a minute distance from the work during machining, and when the machining speed mode is set to the low speed mode and the normal mode, the stripper comes into contact with the work at the time of machining. Is done. As a result, the high-speed mode is selected when importance is placed on productivity, and the low-speed mode or the normal mode is selected when importance is placed on low noise over productivity.

In the present invention, a prefill valve is provided for switching the hydraulic pressure supplied to the cylinder chamber of the punch driving cylinder to be supplied from the tank when the punch is operated at a low load and at a high speed. When the punching load of the punch is equal to or greater than the specified value, the switching operation is controlled so as not to perform the switching operation when the punching load is less than the specified value. It is possible to perform good processing.

Most preferably, the stroke pattern of the punch is a pattern in which the speed is increased at the end of the punching process, that is, a pattern in which the punch position changes with time in a broken line. This broken line pattern is preferably applied in the low speed mode. The speed change at the inflection point of the broken line pattern does not pose any particular problem because the punch speed is low. In the high-speed mode, by changing the punch stroke pattern to a sine wave shape instead of a polygonal line shape, there is no inflection point (a polygonal portion of the polygonal line), and there is no rapid acceleration / deceleration. be able to.

[0016]

Next, a specific embodiment of a method for controlling a punch press according to the present invention will be described with reference to the drawings.

FIG. 1 is a front view of a punch press according to an embodiment of the present invention. As shown in the drawing, in the punch press of the present embodiment, a lower frame 1a having a lower portion integrated with a base and an upper frame 1b fixed to an upper portion of the lower frame 1a have a ring shape (O). ) Is provided. At a position slightly deviated to one side from the central portion of the punch frame 1 in the longitudinal direction, a machining center 2 is disposed with an axis set in the up-down direction. A moving table 3 is arranged inside the punch frame 1 so as to cross the punch frame 1. And
An XY carriage 4 is provided on one side of the moving table 3 so as to be movable in the X-axis direction (a direction perpendicular to the paper surface) and the Y-axis direction (the left-right direction in FIG. 1) along the upper surface of the lower frame 1a. A clamp 6 for gripping a plate-like work 5 is mounted on the XY carriage 4. In this way, the workpiece 5 to be processed is gripped by the clamp 6, positioned by the XY carriage 4 in the X-axis direction and the Y-axis direction, and automatically sent to the punching operation position of the processing center 2.

As shown in FIG. 2, the processing center 2 has a punch (upper die) 7 on the upper frame 1b side and a stripper (plate holder) 8 fitted on the outer shape of the punch 7.
A die (lower die) 9 is mounted on the lower frame 1a side so as to face the punch 7 and the stripper 8. These punch 7, stripper 8 and die 9
Is taken out from a mold magazine (not shown) which is arranged in the set state with the axis parallel to the punch frame 1,
It is transferred to the processing center 2 and replaced. The punch 7, stripper 8 and die 9 form the processing center 2
The punch 7 is moved up and down by the operation of the servo cylinder 10 for driving the punch.
Is moved up and down independently of the punch 7 by the operation of the stripper driving servo cylinder 11.

The punch driving servo cylinder 10 is provided with a piston 10a for moving the punch 7 up and down. The piston 10a causes the inside of the cylinder from above to be a first chamber 10b, a second chamber 10c and a third chamber 10d. It is divided into three rooms. The hydraulic pressure discharged from the hydraulic pressure source P is supplied to the first chamber 10b through the electromagnetically operated servo valve for punch 12 and the prefill valve 13, and the hydraulic pressure source is supplied to the second chamber 10c and the third chamber 10d. The hydraulic pressure is supplied from P via the servo valve 12 for punch.

The prefill valve 13 has a structure in which a spool 13b is provided in a valve body 13a integrated with the servo cylinder 10 for driving the punch. The spool 13 b is moved from the spool control servo valve 14 to the valve body 1.
Operated by pilot pressure supplied to pilot chambers 13c and 13d provided at both ends of 3a, the servo chamber 12 for punching and the first chamber 10b of the servo cylinder 10 for punch driving are connected, or the first chamber is driven. 10b communicates with the tank 15. Here, atmospheric pressure is introduced into the tank 15 from a pipe 15a.

On the other hand, a piston 11 for vertically moving the stripper 8 is provided on the servo cylinder 11 for driving the stripper.
The interior of the cylinder is partitioned into an upper chamber 11b and a lower chamber 11c by the piston 11a. The hydraulic pressure discharged from the hydraulic pressure source P is supplied to the upper chamber 11b and the lower chamber 11c by a high-pressure reducing valve 16, a low-pressure reducing valve 17, an electromagnetically operated switching valve 18, a check valve 19 and an electromagnetically operated servo for a stripper. It is supplied via a valve 20. In FIG. 2, the reference numeral 21 denotes an accumulator.

The punch servo valve 12, the spool control servo valve 14, the stripper servo valve 2
0 and the switching valve 18 are operated by a control signal from the controller unit 22. In order to calculate this control signal, the controller unit 22 receives program data from the automatic programming system (CAD, CAM) 23 and press mode setting data set by a selection switch on the operation panel 24 as a data input unit (not shown). ). Here, the data input from the automatic programming system 23 is the shape of the used mold (perimeter, shear angle,
Clearance), punching load, work plate thickness, and material data. The data set by the operation panel 24 is data for selecting the press mode from among the low speed mode, the normal mode, and the high speed mode. .

The controller unit 22 includes a central processing unit (CPU) 22a for executing a predetermined program, a read-only memory (ROM) 22b for storing the program, and various tables, and workings required for executing the program. Writable memory (RA
M) 22c, and axis control circuits 25a, 25b, 25c and a servo amplifier 26 for controlling the punch servo valve 12, the spool control servo valve 14, and the stripper servo valve 20, respectively.
a, 26b, 26c.

Next, each of the high / low pressure switching control of the stripper 8, the axis control of the stripper 8, the axis control of the punch 7, and the switching control of the prefill valve 13 will be described.

(1) High / low pressure switching control of the stripper 8 Based on each input data of the material of the work, the cutting circumference and the plate thickness inputted from the automatic programming system 23,
The controller section 22 selects the pressure and sets the switching valve 1
8 outputs a selection signal for switching between high and low pressures of the hydraulic pressure supplied to the stripper servo valve 20. Switching valve 1
8 is operated, the high-pressure reducing valve 16 or the low-pressure reducing valve 1
7 is selected. In this way, the stripper pressure is set according to the material of the work, and it is possible to obtain a product with excellent appearance quality without indentation.

(2) Axis control of the stripper 8 (stroke pattern, stroke position control) The die shape (perimeter, shear angle, clearance) input from the automatic programming system 23, punching load,
The controller unit 22 selects a mold in the mold magazine based on each input data of the work thickness and material, and calculates the stroke position of the punch 7 in consideration of the punch height of the selected mold. Then, the controller unit 22 selects a stroke pattern (whether or not to contact the workpiece during punching) of the stripper 8 by a press mode selection signal (low-speed processing, normal processing, high-speed processing) input from the operation panel 24. Then, the stroke position of the stripper 8 is calculated and a command value is output to the axis control circuit 25a. Then, the axis control circuit 25a operates the stripper servo valve 20 via the servo amplifier 26a. Thus, stripper 8
Is set independently of the punch position, and the acceleration of the stripper is limited to a predetermined value, so that it is possible to reduce the processing time and noise.

(3) Axis control of the punch 7 (stroke pattern, stroke position control) Based on a punching load calculated from each input data from the automatic programming system 23 and a press mode selection signal input from the operation panel 24. , The controller unit 22
An axis control circuit is selected by selecting whether the stroke pattern of the punch 7 is a polygonal line pattern or a sine waveform pattern, which will be described later, and calculating the stroke position of the punch 7 from the data of the work thickness, material, and die shear angle. The command value is output to 25b. Then, the axis control circuit 25b is connected to the servo amplifier 2
The punch servo valve 12 is operated via 6b.

(4) Switching control of the prefill valve 13 Whether or not to perform the switching operation of the prefill valve 13 is selected based on the punching load calculated from each input data from the automatic programming system 23. Is
The switching timing is determined from the inflection point of the broken line pattern of the stroke pattern of the punch 7, and a command value is output to the axis control circuit 25c. Then, the axis control circuit 25c operates the spool control servo valve 14 via the servo amplifier 26c.

In the prefill valve 13, when the punch 7 is operated at a low load and at a high speed, the spool 13b is at the position shown in FIG. 3 and the tank 15 and the first chamber 10b are communicated. A large amount of oil in 15 flows into first chamber 10b, and piston 10a is lowered at high speed. On the other hand, when operating the punch 7 with a high load, the spool 13b is switched to the position shown in FIG.
The workpiece 5 is punched by being lowered with a large force by the hydraulic pressure supplied into the second chamber 10c and the second chamber 10b. By controlling the switching of the pre-fill valve 13 in this manner, the punch 7 can be switched to the low-load high-speed mode or the high-load low-speed mode at appropriate times, and efficient machining can be performed.

Next, the operation modes of the punch 7 and the stripper 8 in this embodiment will be described with reference to FIGS. In these figures, (a) and (b)
(C) shows a punch 7 and a stripper 8 according to the passage of time.
(D) also shows the respective positions of the punch 7 and the stripper 8 over time along with the pattern of the prefill valve 13 in a diagram.

(1) Low speed mode (FIG. 5) In the low speed mode, first, the stripper 8 is lowered from the standby point b at the speed V1, and simultaneously, the punch 7 is moved from the standby point a above the standby point b to the speed V2 ( > V1), it is lowered to the standby point c below the standby point b. Next, the punch 7 waits at the standby point c until the stripper 8 comes into contact with the workpiece 5, and after the stripper 8 comes into contact with the workpiece 5, the punch 7 reaches the point e at the speed V1, and then the point g (the lowest point). Until then, punching by the punch 7 is performed while being lowered at the speed V2. After the punching, the punch 7 is raised from the point g to the standby point a at the speed V2, and immediately after the punch 7 is separated from the work 5, the stripper 8 is raised at the speed V2 to the standby point b. In this low-speed mode, the punch 7 and the stripper 8 are both brought into contact with the work 5 at a low speed (V1), so that breakthrough noise can be reduced and indentations on the surface of the work 5 due to the pressing force of the stripper 8 Can be kept small. Also, the stripper 8 comes into contact with the work 5 immediately before the punch 7 comes into contact with the work 5, and the stripper 8 comes off from the work 5 immediately after the punch 7 comes off from the work 5. The processing time can be shortened as compared with the integral type, and the productivity can be improved.
In FIG. 5, reference numeral 27 indicates a punching waste.

(2) Normal Mode (FIG. 6) When the punching load is small, as shown in FIG. 6A, before the punching by the punch 7, the stripper 8 is set to the standby point b as in the low-speed mode. Is lowered at a speed V1 to a position where it comes into contact with the work 5, and after punching, it is raised at a speed V1 to a standby point b. On the other hand, the punch 7 draws a sine waveform from the standby point a and descends to the lowest point g, and then is raised to return to the standby point a to perform punching. When the punching load is large, as shown in FIG. 6B, the punching is performed in the same pattern as in the low-speed mode.

(3) High-speed mode (FIG. 7) When the punching load is small, as shown in FIG. 7A, before the punching by the punch 7, the stripper 8 is moved from the standby point b at the speed V2. It is lowered to the standby point c, and after punching,
The speed is raised to the standby point b at the speed V2. Meanwhile, punch 7
Is drawn from the standby point a to a lowermost point g with a sine waveform, and then raised to return to the standby point a to perform punching. In this case, the sine waveform substantially overlaps the descending straight line and the rising straight line of the stripper 8. When the punching load is large, as shown in FIG. 7B, the stripper 8 moves from the standby point b to the standby point c at the speed V2.
At the same time, the punch 7 is lowered from the standby point a to the standby point c at the speed V2. Next, stripper 8
While waiting at the standby point c, the punch 7 is lowered at the speed V1 until the point e and thereafter at the speed V2 until the point g, and the punching by the punch 7 is executed. After the punching, the punch 7 is raised from the point g to the standby point a at the speed V2, and the stripper 8 is raised at the speed V2 to the standby point b in a manner following the rise of the punch 7. In this high-speed mode, the stripper 8 is moved from the work 5 by a small distance (for example, 0.
The workpiece 5 is punched out while being held at a position separated by 5 mm), that is, at the standby point c, and the workpiece 5 is moved, so that the processing time can be further reduced. This high-speed mode is an effective operation mode when priority is given to improving productivity and minimizing indentations on the surface of the work 5 over noise reduction.

In this embodiment, the control of the punch 7 and the stripper 8 by the controller 22 is performed according to the flow shown in FIG. This flow will be described next.

S1: Data of plate thickness, material, die circumference and shear angle are read from a program input from the automatic programming system 23, and the speed mode (low speed mode, normal mode) of the selector switch of the operation panel 24 is read. , High-speed mode).

S2 to S9: These steps are steps for determining a punch stroke pattern.
First, a punching load is calculated (S2), and it is determined whether the calculated punching load is equal to or greater than a specified value (threshold) (S3).
When the punching load is equal to or more than the specified value, the prefill valve 13 is switched (S4), and the stroke pattern of the punch 7 is changed as shown in FIGS. 5, 6B and 7B. A line pattern is set (S5). On the other hand, when the punching load is less than the specified value, the prefill valve 13 is not switched (S6). In this case, it is determined whether the mode is the low speed mode (S7). (S8), and when the mode is not the low-speed mode, in other words, in the normal mode or the high-speed mode, the sine waveform pattern is set (S8).
9).

S10 to S19: These steps are steps for determining the stripper stroke pattern. First, it is determined whether the stripper pressure is high or low from a chart of the work material and the allowable surface pressure (S10). Then, it is determined whether or not the stripper pressure is a high pressure designation (S1).
1). If high pressure is specified, the stripper pressure is set to high pressure (S12), and then it is determined whether the press mode setting data is set to high speed mode (S1).
3) When the high-speed mode is set, a machining pattern that does not allow the stripper to contact the workpiece is selected (S1).
4) When the mode is not the high-speed mode, in other words, when the mode is the low-speed mode or the normal mode, a processing pattern for bringing the stripper into contact with the work is selected (S15). On the other hand, if the stripper pressure is not specified to be high, the stripper pressure is set to low (S16), and then it is determined whether the press mode setting data is set to high speed mode (S1).
7) When the high-speed mode is set, a machining pattern that does not allow the stripper to contact the work is selected (S1).
8) When the mode is not the high-speed mode, in other words, when the mode is the low-speed mode or the normal mode, a processing pattern for bringing the stripper into contact with the work is selected (S19).

S20 to S23: When the stroke pattern of the punch 7 and the stroke pattern of the stripper 8 are determined by the above-described steps, the operation speed of the punch 7 and the stripper 8 according to each speed mode is determined (S2).
0) Then, the operating positions of the punch 7 and the stripper 8 according to the thickness of the workpiece are determined (S21), and further, the control waveforms that take the mutual timing of the switching of the punch 7, the stripper 8 and the prefill valve 13 are provided. Is determined (S2
2) Execute the processing (S23).

[0039]

As described above, according to the present invention, low noise processing can be performed and high productivity can be obtained.
In addition, the problem of the indentation of the stripper on the work surface can be solved, and the appearance quality can be improved. Further, in the present invention, when the punch is operated at a low load and at a high speed, a prefill valve for switching the hydraulic pressure supplied to the cylinder chamber of the punch driving cylinder to be supplied from the tank is provided. Alternatively, the mode can be appropriately switched to the high-load low-speed mode, and efficient processing can be performed. Further, by selecting the processing speed mode, it is possible to meet the needs of each of the case where importance is attached to productivity and the case where importance is attached to low noise.

[Brief description of the drawings]

FIG. 1 is a front view of a punch press according to an embodiment of the present invention.

FIG. 2 is a configuration diagram of a control system according to the present embodiment.

FIG. 3 is a diagram illustrating the operation of a prefill valve according to the present embodiment.

FIG. 4 is a diagram illustrating the operation of a prefill valve according to the present embodiment.

FIG. 5 is an explanatory diagram of an operation in a low-speed mode of the embodiment.

FIG. 6 is an explanatory diagram of an operation in a normal mode according to the present embodiment.

FIG. 7 is an explanatory diagram of an operation in a high-speed mode of the embodiment.

FIG. 8 is a flowchart showing a control flow of a punch and a stripper in the embodiment.

[Explanation of symbols]

 2 Machining center 5 Work 7 Punch 8 Stripper 9 Die 10 Punch drive servo cylinder 11 Stripper drive servo cylinder 12 Punch servo valve 13 Prefill valve 14 Spool control servo valve 15 Tank 16 High pressure reducing valve 17 Low pressure reducing valve 18 Switching Valve 20 Servo valve for stripper 22 Controller unit 23 Automatic programming system 24 Operation panel 25a, 25b, 25c Axis control circuit 26a, 26b, 26c Servo amplifier

──────────────────────────────────────────────────の Continuation of the front page (51) Int.Cl. ⁷ identification code FI B30B 15/16 B30B 15/16 D 15/22 15/22 B (58) Field surveyed (Int.Cl. ⁷ , DB name) B21D 28/00-28/02 B21D 28/24 B30B 15/00 B30B 15/16 B30B 15/22 B30B 15/28

Claims (7)

(57) [Claims] A punch and a die for punching a workpiece;
In a punch press machine provided with a stripper for holding a work when the punch is lifted, a work thickness and material information of the work, punching load information of the punch calculated from the work thickness and material information, and a preset processing Controlling the punching press machine based on speed mode information, calculating the pressure of the stripper and the stroke pattern of the stripper and the punch, and controlling the stripper and the punch based on the calculation result. Method. 2. The method according to claim 1, wherein the processing speed mode can be set to one of a low speed mode, a normal mode, and a high speed mode. 3. The stripper according to claim 2, wherein the stripper is held at a position separated from the workpiece by a small distance during the processing in the high-speed mode, and the stripper contacts the workpiece during the processing in the low-speed mode and the normal mode. Control method of punch press machine. 4. A prefill valve for switching the hydraulic pressure supplied to a cylinder chamber of a punch driving cylinder to be supplied from a tank when the punch is operated at a low load and at a high speed is provided. 4. The control method for a punch press according to claim 1, wherein the switching operation is performed when the punching load of the punch is equal to or more than a specified value, and the switching operation is not performed when the punching load is less than the specified value. 5. When the prefill valve is switched, or when the processing speed mode is the low speed mode even when the prefill valve is not switched, the stroke pattern of the punch is determined based on time. 5. The control method for a punch press according to claim 4, wherein the position is set to change in a polygonal line. 6. When the prefill valve is not switched, and the processing speed mode is a normal mode or a high speed mode, the punch stroke pattern is such that the punch position with respect to time changes in a sine wave shape. The control method for a punch press according to claim 4, wherein the control method is set to: 7. A hydraulic pressure is supplied to a punch driving cylinder, a stripper driving cylinder, and a spool of a prefill valve through respective hydraulic servo valves, and these hydraulic servo valves are controlled by signals from respective servo amplifiers. The method for controlling a punch press according to any one of claims 1 to 6.