JP2001047148A - Method for controlling stripper of punch press and controller therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To adjust the pressurizing force of a stripper to a proper value by preliminarily setting the pressurizing force value of the stripper and clamping a work with the stripper and the metallic mold of a lower die and then by changing over the control of the stripper from position control to pressure control. SOLUTION: The positions of a punch shaft piston 1, a stripper shaft piston 10 and a lower die shaft piston 19 are detected with a punch shaft position detector 5, a stripper shaft position detector 14 and a lower die shaft position detector 21 and their data are inputted to a controller 29. When a sheet 26 is clamped with the stripper 32 and the metallic mold 33 of the lower die, the control of the stripper shaft 54 is changed over from the position control to the pressure control. The oil pressure in a stripper shaft pressurizing chamber 17 is detected with a pressure detector 11 on the stripper shaft pressurizing side. A pressure command is outputted to a stripper shaft servo valve 13 by the controller 29 so that the difference between the detected value and the set value becomes zero. Whether or not the detected value is larger than the threshold value is judged with the controller 29 and, when the detected value is larger than the threshold value, the generation of abnormality is informed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a punch press stripper control method and control apparatus.

[0002]

2. Description of the Related Art Some punch presses for punching and forming a sheet material between an upper die and a lower die have a stripper for pressing the plate material from the upper surface during processing. FIG. 7 shows an example of the configuration of a punch press having a stripper, and the prior art will be described with reference to FIG. The punch press includes a press unit 51, a control device 29, a mold magazine 27 device (hereinafter, referred to as a magazine 27), an automatic mold changing device (hereinafter, referred to as a magazine change device).
ATC 28) and a table device (hereinafter referred to as an XY table 30). The press unit 51 is a device that punches a hole in a metal plate (hereinafter, referred to as a plate 26) as a work, or forms a groove or a depression based on a command signal from the control device 29.

[0003] The press section 51 includes a punch shaft 52, a die shaft 5
3 and a stripper shaft 54. Each shaft has a punch shaft cylinder 6, a die shaft cylinder 22, and a stripper shaft cylinder 15 as hydraulic actuators.
The pressing force of the punch shaft 52 is generated independently by the punch shaft piston 1, the pressing force of the die shaft 53 is generated by the lower die shaft piston 19, and the pressing force of the stripper shaft 54 is generated by the stripper shaft piston 10. The center of the stripper shaft piston 10 in the longitudinal direction is hollow, and the tip of the punch shaft piston 1 is inserted into this hollow portion.
A punch die 31 is detachably fitted on the lower surface of the punch shaft piston 1, a lower die mold 33 is placed on the upper surface of the lower die piston 19, and a stripper 32 is detachably fitted on the lower surface of the stripper shaft piston 10. In addition, a pass line Ph, which is the transport height position of the plate 26, is set between the lower surface of the stripper 32 and the upper surface of the lower die 33. The control device 29 issues a command to change the amount of temporal expansion and contraction of the punch shaft piston 1, the stripper shaft piston 10 and the die shaft piston 19 of the press unit 51 and the positioning of the XY table based on work conditions and the like set in advance by the operator. A command is calculated, and the calculated change command and positioning command are output to the press unit 51 and the XY table 30, respectively. The XY table 30 has two axes of freedom in the XY directions in a horizontal plane.
6 is placed, and one end of the plate 26 is also clamped for movement and positioning. When a certain portion of the plate 26 is processed by the press unit 51, the XY table 30 positions the next processing position of the plate 26 at the processing axis position of the press unit 51.

In the punch press described above, the plate 26 is supported from below by the lower die 33, and in the case of the downward forming process in which the punch die 31 is lowered, first, the stripper 32 is lowered. Then, the lower surface of the stripper is positioned at a position where it comes into contact with the upper surface of the plate 26. Next, the lower die 33 is raised to position the upper surface of the lower die 33 (hereinafter, referred to as the cutting edge of the lower die 33) at a position where it comes into contact with the lower surface of the plate 26. After that, the control of the stripper shaft 54 is switched from the position control to the pressure control. After switching to the pressure control, the punch die 31 is lowered, and a predetermined molding is performed on the plate 26 sandwiched between the punch die 31 and the lower die die 33. After molding, stripper 3
2 is returned from pressure control to position control, and the lower die 3
3 is lowered to separate from the plate. Next, the punch die 31
And finally the stripper 32 is raised to complete the molding.

[0005]

However, the above conventional punch press has the following problems. The pressure applied to the plate 26 during the pressure control of the stripper 32 is not independently set, but is controlled so as to be a predetermined ratio (for example, 15%) of the withstand pressure, which is the pressure at which the mold used is broken. It is automatically calculated by the device 29 and set. However, the withstand pressure as the mold data is a value set in the control device for protecting the mold before the operation, and the force of the punch mold 31 and the lower die mold 33 is smaller than the force corresponding to the set withstand pressure. When the size becomes too large, the overload detection function is activated to prevent the mold from being damaged. As described above, since the pressing force of the stripper 32 on the plate 26 is determined by the die used, when the pressing force of the stripper 32 is too strong, an impression remains on the plate surface, and when the pressing force of the stripper 32 is too weak, the plate is left. During molding, it is likely to shift in the horizontal direction, and it may be difficult to obtain sufficient molding accuracy.

When sufficient forming accuracy cannot be obtained because the plate 26 is displaced in the horizontal direction due to a small pressing force of the stripper, the forming accuracy is improved by increasing the withstand pressure data set so that no imprint remains. . However, since the actual withstand pressure of the cutting edge is smaller than the set withstand pressure data, the die may be damaged before the overload detection function is activated when an overload is applied for some reason. When the withstand pressure to be set is reduced, the pressing force is reduced. However, since the set withstand pressure data is smaller than the actual withstand pressure of the cutting edge, the force output from the punch die 31 and the lower die die 33 is reduced. There is a problem in that the overload detection function is activated before the set withstand pressure of the cutting edge is reached, and the machine is frequently stopped.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to provide a punch press stripper control method and a control apparatus which can appropriately set the stripper pressure.

[0008]

In order to achieve the above object, a first aspect of the present invention is to provide a method in which a stripper presses a workpiece from an upper surface and moves up and down between a punch die and a lower die. In a punch press stripper control method of controlling a stripper pressing force at the time of forming, a stripper pressing force value is set in advance, and at the time of actual forming processing, the work is moved to the lower surface of the stripper and the lower die or lower. After sandwiching between the upper surface of the ejector plate mounted on the die and the die, the control of the stripper is switched from the position control to the pressure control, and during this pressure control, the actual pressure value of the stripper is maintained at the set stripper pressure value. And

According to the first invention, at the time of forming a work,
Position the lower surface of the stripper at the position where it abuts on the upper surface of the work, and then raise the lower die or the ejector plate attached to the lower die, and the upper surface of the lower die or the ejector plate is Position it at the contact position. When the control of the stripper shaft is switched from the position control to the pressure control in a state where the work is held between the stripper and the lower die or the ejector plate, the actual applied pressure value of the stripper is different from the withstand pressure of the die in advance. Is set to the stripper pressure value set in (1). Since the stripper pressure value can be set separately from the withstand pressure of the mold, the stripper pressure value can be set finely in consideration of the work thickness, material, processing shape, processing method, and the like. Thus, the work can be clamped by an appropriate stripper pressing force, so that a stripper control method of a punch press with excellent processing quality, which does not cause the work to be displaced in the horizontal direction and does not leave a pressure mark on the work. be able to. Also, the stripper pressure value, which was previously set as a value dependent on the withstand pressure at which the mold is damaged, can be set independently and independently, so that one of the molds can now be set independently. The pressure allows accurate overload detection and prevents the mold from being damaged before overload is detected, and the machine from frequently stopping due to the overload detection function frequently detecting overload.

According to a second aspect based on the first aspect, during the pressure control of the stripper, the actual pressure value is compared with a predetermined threshold value corresponding to the set stripper pressure value, and the actual pressure value is larger than the threshold value. When this happens, a method of notifying the occurrence of an abnormality is adopted.

According to the second invention, during the pressure control of the stripper, it is determined whether or not the actual pressure value of the stripper is larger than a predetermined threshold value corresponding to the pressure value of the stripper. When the actual applied pressure value is larger than the predetermined threshold value, a notification signal is output to the notification unit. As a result, it is possible to know the occurrence of abnormalities quickly, so that it is possible to know the occurrence of abnormalities quickly and prevent large quantities of defective moldings from occurring, as well as measures to prevent abnormalities. Can be done early.

According to a third aspect of the present invention, there is provided a punch die attached to a punch shaft piston movably provided in a vertical direction, a die shaft piston movably provided in the same direction as the punch die, and a punch die. In a predetermined sequence, a lower die mold oppositely attached and a stripper attached to a stripper shaft piston movably provided in the same direction as the punch mold and pressed from the upper surface of the workpiece during molding, A control command is output to the press shaft driving means for driving the press shafts of the punch shaft piston, the die shaft piston, and the stripper shaft piston to control the position of the press shaft, thereby forming a work between the punch die and the lower die. And a control device for controlling the actual pressure value of the stripper based on the pressure value from the stripper pressure detection means. The control device includes a stripper pressure value storage unit that presets and stores a predetermined stripper pressure value as a target pressure value of the stripper, and, during actual forming processing, stores the work on the lower surface of the stripper and the lower die metal. After sandwiching between the upper surface of the ejector plate mounted on the die or lower die, the control of the stripper is switched from position control to pressure control, and the deviation between the stripper pressure value and the actual stripper pressure value is calculated during this pressure control. And a pressure comparator for outputting a stripper pressure command corresponding to the calculated deviation value to the stripper shaft driving means.

According to the third aspect of the present invention, the control device has a stripper pressure value storage unit for presetting and storing the stripper pressure value separately from the withstand pressure of the mold, and stores the work in the stripper and the lower die metal. When the control method of the stripper is switched from the position control to the pressure control in a state where the stripper is sandwiched between the mold and the ejector plate, the pressure comparison unit performs the predetermined pressurization stored in the actual pressurization pressure value of the stripper and the stripper pressurization value storage unit. A deviation value between the pressure values is calculated, and a stripper pressure command corresponding to the calculated value is output to the stripper shaft driving means. Thus, the actual pressure value of the stripper is set to the stripper pressure value. As a result, the work can be clamped by an appropriate stripper pressing force, so that a stripper control device for a punch press with excellent processing quality that does not shift the work in the horizontal direction and does not leave a pressure mark on the work. Obtainable. Also, the stripper pressure, which was previously set as a value that depends on the withstand pressure at which the mold is damaged, can be set independently and independently, so that the withstand pressure of one of the molds can now be set independently. In addition, accurate overload detection can be performed, and the die does not break before the overload is detected, and the machine does not stop frequently because the overload detection function frequently detects the overload.

In a fourth aspect based on the third aspect, the control device compares the actual pressure value of the stripper with a predetermined threshold value corresponding to the set and stored stripper pressure value, and determines the actual pressure value of the stripper. Is greater than the threshold value, a pressure comparison unit that outputs a notification command, and a notification unit that issues a warning or warning display based on the notification command.

According to the fourth aspect of the present invention, the pressure comparing section of the control device compares the actual pressure value of the stripper with a predetermined threshold value corresponding to the set and stored stripper pressure value. When it is determined that the value is larger than the threshold value, the notification command is output to the notification unit, and the notification unit notifies by a warning or a warning display based on the notification command. As a result, it is possible to know the occurrence of abnormalities quickly, so that it is possible to know the occurrence of abnormalities quickly and prevent large quantities of defective moldings from occurring, as well as measures to prevent abnormalities. Can be done early.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a hardware configuration diagram of a punch press according to the present invention. The same elements as those in FIG. 7 will be described with the same reference numerals. The description of the overall configuration of the punch press and the layout of each axis of the press unit 51 described with reference to FIG. 7 is omitted here. Punch shaft pressurizing chamber 8
An electromagnetically operated punch shaft servo valve 4 for controlling pressure oil to the punch shaft pulling chamber 9 is disposed between the punch shaft cylinder 6 and a hydraulic source (not shown). Further, a stripper shaft servo valve 13 for controlling pressure oil to the stripper shaft pressurizing chamber 17 and the stripper shaft pulling up chamber 18 is provided between the stripper shaft cylinder 15 and a hydraulic pressure source. Further, a lower die axis servo valve 20 for controlling the pressure oil to the lower die axis pressurizing chamber 24 and the lower die axis lowering chamber 25 is arranged between the lower die axis cylinder 22 and the hydraulic pressure source. Each servo valve is an example of a driving unit for each axis. Further, the control device 29 outputs a punch axis servo valve command Cp, a stripper axis servo valve command Css, and a die axis servo valve command Cd for instructing the stroke or pressure of each axis to the servo valves of each axis. further,
The table positioning command Cxy is output from the control device 29 to a drive motor (not shown) of the XY table 30.

As the detectors, a punch shaft position detector 5, a stripper shaft position detector 14, and a lower die shaft position detector for detecting the positions of the punch shaft piston 1, the stripper shaft piston 10, and the lower die shaft piston 19, respectively. Vessel 21
Are provided near each piston. Also, the punch shaft piston position P detected by each position detector.
p, the stripper shaft piston position Ps, and the die shaft piston position Pu are input to the controller 29. Also, a stripper shaft pressure side pressure detector 11 and a stripper shaft upper pulling pressure detector 12 as stripper pressure detecting means for detecting the oil pressure of the stripper shaft pressurizing chamber 17 and the stripper shaft pulling up chamber 18 are provided in the respective chambers. Attached nearby.
Further, the stripper shaft pressing side pressure P1 and the stripper shaft pulling upper pressure P2 detected by each pressure detector are input to the control device 29.

FIG. 2 shows a control block diagram of the control device 29 of the punch press according to the present invention. The control device 29 includes a machining program 34, an operation pattern storage unit 41, a mold management information storage unit 35, a notification unit 59, and a control calculation unit 57. In the machining program 34, instructions for performing the machining as shown in FIG. 3 are described. In particular, machining material thickness information data relating to the thickness of the plate 26 to be machined according to the present invention, the punch shaft 52, the stripper Standby position information data regarding a position where the shaft 54 and the die shaft 53 stand by before machining;
An XY table positioning instruction and a press processing instruction are described. The machining program 34 is in NC language, P
Although it can be described in a programming language such as an LC language, an example in which the description is made by an NC instruction will be described below.

As shown in Table 1, a press operation pattern corresponding to the type of molding process of a die to be used is set and stored in the operation pattern storage section 41 in advance. That is,
The speed of each axis, the standby position, and the like are stored as a data group for each operation pattern number indicating the pattern content.

[Table 1]

In the die management information storage unit 35, data on the die to be used as shown in Table 2 is set and stored in advance. That is, a mold number is defined for the punch mold 31, the lower die mold 33, and the stripper 32 used in the set, and in addition to the physical specifications such as the shape and the diameter, predetermined molds using the mold are used. The press operation pattern corresponding to the type of the forming process is stored as a numerical value indicating the content of the operation pattern.
Further, a withstand pressure and a stripper pressure are set for each mold. For example, in a mold for forming a lower embossed shape of the mold T200, the mold withstand pressure is 15.00 Ton and the stripper pressure is 2.5 Ton. It is remembered. In addition,
The lower emboss shape is a molded shape that forms a convex circular depression below the plate 26. Further, various data to be stored in the mold management information storage unit 35 can be set on the setting screen shown in FIG.
0, the withstand pressure of the mold is reduced to a stripper pressure of 2.5 (to
The stripper pressure value is set according to n). The stripper pressure set separately from the withstand pressure of the mold is stored in a pressure storage unit 60 described later.

[Table 2]

Next, the control calculation section 57 will be described. The control calculation unit 57 includes a processing command unit 36, a stripper pressure value storage unit 60, a stroke calculation unit 64, a switching unit 67, a pressure comparison unit 65, a stroke comparison unit 66, a pressure processing unit 68, and a stroke processing unit 69. ing. The machining command unit 36 is configured to execute a mold designation command (NC) stored in the machining program 34.
(T code in language) is retrieved, and in the order of use, the mold information corresponding to the mold number written in the instruction is extracted from the mold management information storage unit 35, and the stroke calculation unit 64 The use mold order data as shown is created. Further, the work material thickness information data and the standby position information data described in the machining program 34 are also stored in the stroke calculation unit 6.
4 to be stored. The stripper pressure value storage unit 60 stores the stripper pressure value F of the target pressure value of the stripper set in the mold management information storage unit 35, and compares the stripper pressure value F with the pressure comparison unit 65. Output to

[Table 3]

When machining is started, the stroke calculation unit 64 reads a data group of the corresponding operation pattern number in the operation pattern storage unit 41 by referring to the operation pattern number data of the used mold sequence data shown in Table 3, and determines the operation pattern. Set. Further, based on the read work plate thickness information data and the standby position information data, the cutting edge position data Pc of each press shaft is calculated and output to the stroke comparison unit 66. In addition, based on the operation pattern and the calculated cutting edge position data Pc and the like, a switching command for switching the control of the stripper shaft from position control to pressure control and from pressure control to position control is output to the switching unit 67.

The pressure processing section 68 takes in the pressure P1 and the pull-up pressure P2 of the stripper shaft 54 on the pressing side, and calculates the equation "P
The actual pressure value Fsp of the stripper piston 10 calculated by “1 × A1−P2 × A2” is calculated and the pressure comparison unit 65 is calculated.
Output to A1 and A2 are the pressure receiving areas of the stripper shaft pressurizing chamber and the stripper shaft pulling chamber, respectively.

The stroke processing unit 69 takes in the punch shaft piston position Pp, the stripper shaft piston position Ps, and the die shaft piston position Pu, and outputs to the stroke comparison unit 66 actual stroke information Pa including stroke information of these three axes. .

The pressure comparator 65 calculates a deviation value between the input stripper pressure value F and the actual pressure value Fsp,
The pressure command Cf corresponding to the calculated deviation value is output to the switching unit 67. Further, it is determined whether the actual pressure value Fsp is larger than a threshold value (for example, 1.1 times the stripper pressure value F) corresponding to the stripper pressure value F, and it is determined that the actual pressure value Fsp is larger than the threshold value. In some cases, the notification command Ar is output to the notification unit 59. When the notification command Ar is input, the notification unit 59 notifies the user by sounding a buzzer or blinking a warning light.

The stroke comparing section 66 calculates a deviation value between the input actual stroke information Pa and the cutting edge position data Pc, and generates a punch axis servo valve command Cp and a die axis servo valve command Cd according to the calculated deviation value. Output to the punch axis servo valve 4 and the die axis servo valve 20, respectively. The stripper shaft position command Cs corresponding to the calculated deviation value is output to the switching unit 67.

The switching section 67 selects either the pressure command Cf or the stripper axis position command Cs as the stripper axis servo valve command Css according to the switching command from the stroke calculation section 64 and outputs the same to the stripper axis servo valve 13. .

The operation of the punch press having the above configuration will be described with reference to a working program example shown in FIG. For example, a mold number T200 for molding the lower emboss shown in Table 2
Is read, the ATC 28 takes out the lower embossing die from the magazine 27 and attaches it to the press unit 51. When the lower embossing die is attached to the press unit 51, data corresponding to the die number T200 of the die order data shown in Table 3 is transferred to the stroke calculation unit 64. At the same time, a data group corresponding to the operation pattern 11 of the mold number T200 shown in Table 3 (indicated by the operation pattern 11 in Table 2) is transferred from the operation pattern storage unit 41 to the stroke calculation unit 64. Next, before the machining is started, the machining command unit 36 supplies the stroke calculation unit 64 with the workpiece material thickness information data ((T1.
6)) and standby position information data ((P5.
0)) is transferred and stored. Based on the above data, the stroke position data P
When c is calculated, each axis of the press unit 51 positioned at the die changing position by the ATC 28 moves to its standby position. Then, for example, when the XY table 30 is moved and positioned by the moving processing command of “G00X150.Y300.” Shown in the processing program example of FIG. Is output, and each axis of the press section 51 operates according to the calculated operation pattern to process the plate 26. These series of processing controls are performed for each mold number command.

An embodiment of the forming method by the punch press according to the present invention described above with reference to FIGS. 1, 2, 3, 4 and Tables 1, 2, 3 will be described with reference to FIGS. FIG.
The temporal motion of each stroke of the punch shaft 52, the stripper shaft 54, and the die shaft 53 at the time of the lower embossing is shown, and the vertical axis represents the distance D, and the zero of the distance D is the position of the pass line Ph. In the following description, the time of the node of the motion is represented by a number with E added. FIG. 6 shows the relative positions of the punch die 31, the stripper 32 and the lower die 33 during lower embossing. Here, it is assumed that the lower die 33 integrated with an ejector plate 46 which is an auxiliary material for easily detaching the cutting edge of the lower die 33 from the work 26 after the molding is completed. In this case, it is assumed that the upper surface of the ejector plate 46 urged by the elastic body 50 matches the upper surface of the lower die 33 when the elastic body 50 has a free length. Depending on the thickness, material, molding shape, etc. of the plate 26, when the elastic body 50 has a free length, the upper surface of the ejector plate 46
In some cases, a lower die mold that does not match the upper surface of the lower die 3 may be used, or a lower die mold 33 that does not have the ejector plate 46 may be used.

When the servo valve of each axis of the press section 51 receives a command from the control device 29, the punch axis 52 and the stripper axis 54 come from above the plate 26, and the die axis 53 goes to the plate 26
The operation of approaching the plate 26 from below is started.
The punch shaft piston 1 positions the cutting edge (represented by Pt in the motion diagram) of the punch die 31 at the deceleration position Pd calculated based on the height dimension of the punch die and the thickness of the work material (E1). Here, the deceleration position Pd is a position that is above the upper surface of the plate 26 by a predetermined distance (for example, 2 mm). The stripper shaft piston 10 positions the lower surface (represented by St in the motion diagram) of the stripper at the upper surface position of the plate 26 calculated based on the stripper thickness and the workpiece thickness (E2). After the lower surface of the stripper is positioned on the upper surface of the plate 26, the lower die shaft piston 19 is moved to the lower die mold 33.
The cutting edge (represented by Dt in the motion diagram) is positioned at the lower surface position of the plate 26 as shown in FIG. 6A (E3).

After the plate 26 as shown in FIG. 6A is sandwiched between the lower surface of the stripper and the cutting edge of the lower die 33, the switching unit 67 controls the position of the stripper shaft 54 by position control. To pressure control. At the time of the pressure control, the pressure comparator 65 calculates a deviation value between 2.5 ton of the stripper pressure value F indicated as the stripper pressure in Table 3 and the actual pressure value Fsp, and the calculated deviation value becomes zero. Such a pressure command Cf is output from the control device 29 to the stripper shaft servo valve 13. Thus, the actual pressure value Fsp is set to the stripper pressure value F. At this time, the pressure comparing section 65 determines whether or not the actual pressure value Fsp is larger than a threshold value corresponding to the stripper pressure value F. When it is determined that the actual pressure value Fsp is larger than the threshold value corresponding to the stripper pressure value F, the pressure comparing section 65 outputs a notification command to the notification section 59. The notifying unit 59 gives a notification by sounding a buzzer or blinking a warning light.

When the stripper shaft 54 switches to the pressure control, the stripper pressure value F set in the die data is set.
The plate 26 is firmly held by the holding force according to the above, and thereafter, the cutting edge of the punch die 31 moves to the molding position and is positioned (E4 to E5). The forming position is the final position of the cutting edge when the forming is completed. The plate 26 is pressed into the lower die 33 while the cutting edge of the punch die 31 is moving to the forming position to form. FIG. 6B shows a state where the cutting edge of the punch die 31 has reached the forming position. After a lapse of molding time since the punch shaft piston 1 positions the cutting edge of the punch die 31 at the molding position, the switching unit 67 sets the stripper shaft 54
Is returned from pressure control to position control (E6). At this time, the molding is completed, and the position control is restarted from the position of the stripper shaft piston at the time of the end of the pressure control. After the molding is completed, the lower die 33 is lowered, and then the punch die 31 is raised. Then, the stripper 32 is raised and detached from the plate 26 to complete the forming process.

Next, the operation and effect of the present embodiment will be described. When the mold data is stored in the mold management information storage unit 35, the stripper pressure is stored separately from the withstand pressure of the mold as shown in the setting screen of FIG. At the time of actual machining, the stripper pressure is transferred to and stored in the stripper pressure value storage unit 60 as a stripper pressure value F. When the plate is formed, the lower surface of the stripper 32 is positioned at a position in contact with the upper surface of the plate 26, and then the upper surface of the lower die is positioned at a position abutting on the lower surface of the plate 26. With the plate 26 held in this manner, the control of the stripper shaft 54 is switched from the position control to the pressure control, and the pressure of the stripper piston 10 is set to the stripper pressure value F. This pressure control is continued from when the molding of E3 in FIG. 5 is started until the molding of E6 is completed. Thus, since the stripper pressure value F can be set separately from the withstand pressure of the mold, the stripper pressure value F can be set finely according to the material of the plate, the processing shape, the processing method, and the like.
It is possible to obtain a punch press stripper control method and an apparatus thereof that are excellent in processing quality without causing the work to be displaced in the horizontal direction and leaving no imprint. In addition, the original overload detection function of the mold can protect the mold, and the mold can be damaged or frequently overloaded before the overload detection function detects overload as in the past. By detecting, a stripper control method and a control apparatus for a punch press that does not stop the machine frequently can be obtained. During the pressure control, the control device sets the actual pressure value Fs
It is determined whether or not p is larger than a predetermined threshold. When the actual applied pressure value Fsp is larger than the predetermined threshold value, a notification signal is output to the notification unit. As a result, it is possible to know the occurrence of abnormalities quickly, so that it is possible to know the occurrence of abnormalities quickly and prevent large quantities of defective moldings from occurring, as well as measures to prevent abnormalities. Can be done early.

As described above, according to the present invention, it is possible to separately set the stripper pressure value, which is the force relating to the impression of the plate and the displacement of the plate, and the mold withstand pressure of the force at which the mold is damaged. This allows the stripper pressure value to be set finely according to the material, processing shape, processing method, etc. of the plate, so that during pressure control, the workpiece does not shift in the horizontal direction and no pressure marks remain. Excellent punch press stripper control. In addition, the original overload detection function of the mold can protect the mold, and the mold can be damaged or frequently overloaded before the overload detection function detects overload as in the past. The detection enables punch press stripper control without frequent machine stoppages. During the pressure control of the stripper shaft, the actual pressing force is compared with a threshold value corresponding to the set pressing force value, and a notification signal is output to the notification unit when the actual pressing force is larger than the threshold value.
As a result, it is possible to know the occurrence of abnormalities quickly, so that it is possible to know the occurrence of abnormalities quickly and prevent large quantities of defective moldings from occurring, as well as measures to prevent abnormalities. Can be done early. In addition, since the stripper pressure can be set appropriately, frequent stoppages of the machine due to the overload detection function are eliminated, so that the interval between trial hits is shortened, and the setup time is shortened, thereby improving productivity. Further, since the withstand pressure of the mold can be set independently, the correct withstand pressure of the mold can always be set, so that the abnormality can be reliably and accurately detected. This allows
Since mold damage and machine damage can be prevented beforehand, machine maintenance time can be reduced and productivity can be improved. If the stripper pressure is set to zero and the zero is defined as position control on the setting screen when setting and storing in the mold information storage unit, the pressure of the pressure control of the stripper shaft is controlled by one variable. Therefore, it is possible to obtain a punch press stripper control method and a control device having a simple setting method since the size and position control of the punch press can be defined.

[Brief description of the drawings]

FIG. 1 is a hardware configuration diagram of a punch press according to the present invention.

FIG. 2 is a control block diagram of a control device.

FIG. 3 is an example of a machining program of a control device.

FIG. 4 is an explanatory diagram of a setting screen when setting mold data in a mold information management storage unit.

FIG. 5 is an explanatory diagram of a forming motion during lower embossing.

FIG. 6 is an explanatory diagram of relative positions of a punch axis, a stripper axis, and a die axis during lower embossing.

FIG. 7 is a schematic explanatory view of a punch press.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Punch axis piston, 2 ... Punch axis pressure side pressure detector, 3 ... Punch axis upper side pressure detector, 4 ... Punch axis servo valve, 5 ... Punch axis position detector, 6 ... Punch axis cylinder, 8 ... Punch Shaft pressurizing chamber, 9 ... Punch shaft pulling chamber, 10
... Stripper shaft piston, 11 ... Stripper shaft pressure side pressure detector, 12 ... Stripper shaft pulling upper pressure detector,
13: Stripper shaft servo valve, 14: Stripper shaft position detector, 15: Stripper shaft cylinder, 17: Stripper shaft pressurizing chamber, 18: Stripper shaft pulling upper chamber, 19: Lower die shaft piston, 20: Lower die shaft servo Valve, 21 ...
Lower die shaft position detector, 22 ... Lower die shaft cylinder, 24 ...
Lower die shaft pressurizing chamber, 25: Lower die shaft pulling upper chamber, 26: Plate, 2
7 mold magazine, 28 ATC, 29 control device, 3
0 ... XY table, 31 ... Punch die, 32 ... Stripper, 33 ... Lower die die, 34 ... Processing program, 35 ...
Die management information storage unit, 36 processing instruction unit, 41 operation pattern storage unit, 51 press unit, 52 punch shaft, 53
... Die axis, 54 ... Stripper axis, 57 ... Control operation unit, 6
0: stripper pressure value storage unit, 64: stroke calculation unit, 65: pressure comparison unit, 66: stroke comparison unit, 67
... Switching part, Ph ... Pass line, Pd ... Deceleration position, Fsp
... Stripper actual pressure value, F ... Stripper pressure value.

Claims (4)

[Claims] A stripper control of a punch press for holding a work from a top surface of a work with a stripper, forming a work between a punch die that moves up and down, and a lower die, and controlling a pressing force of the stripper at the time of forming. In the method, the stripper pressure is set in advance, and the workpiece is clamped between the lower surface of the stripper and the upper surface of the lower die or the ejector plate mounted on the lower die during actual forming, and then the stripper is controlled. A method for controlling a punch press stripper, characterized by switching from position control to pressure control, and maintaining the actual pressure value of the stripper at a set stripper pressure value during the pressure control. 2. The stripper control method for a punch press according to claim 1, wherein during the pressure control of the stripper, the actual pressure value is compared with a predetermined threshold value corresponding to the set stripper pressure value. A stripper control method for a punch press, wherein the occurrence of an abnormality is notified when it becomes larger than the above. 3. A punch die attached to a punch shaft piston movably provided up and down, and a die shaft piston movably provided in the same direction as the punch die, facing the punch die. A lower die mold attached, a stripper attached to a stripper shaft piston movably provided in the same direction as the punch mold, and a stripper pressed from the upper surface of the workpiece during molding, and a punch shaft piston in a predetermined sequence. A control command is output to the press shaft driving means for driving the press shafts of the die shaft piston and the stripper shaft piston, respectively, to control the position of the press shaft, and to form a work between the punch die and the lower die die. And a control device for controlling the actual pressure value of the stripper based on the pressure value from the stripper pressure detection means. The apparatus includes: a stripper pressure value storage unit that presets and stores a predetermined stripper pressure value as a target pressure value of the stripper; and, during actual molding, the workpiece is transferred to the lower surface of the stripper and the lower die or lower die. After being clamped by the upper surface of the ejector plate mounted on the die, the control of the stripper was switched from the position control to the pressure control, and the deviation value between the stripper pressure value and the stripper actual pressure value during this pressure control was calculated and calculated. A stripper control device for a punch press, comprising: a pressure comparison unit that outputs a stripper pressure command according to a deviation value to a stripper shaft driving unit. 4. The stripper control device for a punch press according to claim 3, wherein the control device compares the actual pressure value of the stripper with a predetermined threshold value corresponding to the set and stored stripper pressure value,
A punch press, comprising: a pressure comparison unit that outputs a notification command when it is determined that the actual applied pressure value of the stripper is greater than a threshold value; and a notification unit that outputs a warning or warning based on the notification command. Stripper control device.