JPH055566B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Field of Application) The present invention relates to a punch press, and particularly to a cylinder type punch press that can accurately detect stripping errors.

(Prior Art) Among punch presses such as turret punch presses, various so-called knock-type punch presses are known in which a workpiece is punched by pressing the upper end of the punch with the lower end of the ram. In this striking type punch press, a stripper spring is attached to the punch which is forced into a predetermined position by a lift spring.
The punch is stripped from the workpiece by the stored force of the stripper spring during the downward stroke of the ram.

However, due to wear of the tip of the punch, the force required for the strip increases abnormally, fatigue of the stripper spring causes a decrease in the accumulated effort, or breakage of the stripper spring causes the contact between the workpiece and the punch to deteriorate. Separation is not performed, and various so-called strip failures occur.

Conventionally, as a method for detecting this type of stripping error, for example, as shown in Japanese Patent Publication No. 57-39850, a DC power source is interposed between a die placed facing the punch and the ram. It is known to connect the In order to determine the detection position of a stripping error, a limit switch is provided that is turned on within a predetermined stroke range centered on the lowering end of the ram.

In the above configuration, when the punch pressed by the lower end of the ram comes into contact with the workpiece, energization is started.
This energization continues until the punching process is completed and the tip of the punch separates from the workpiece. Then, by taking the logical sum of this energization signal and the on-time of the limit switch, the logical sum signal is different between the normal state where no stripping error occurs and the abnormal state where a stripping error occurs, so that a stripping error can be detected. be.

(Problems to be Solved by the Invention) According to the method for detecting stripping errors in a punch press as described above, the stroke position of the ram is not detected point by point, and the limit switch is not configured to detect the detection position of a stripping error. Must be provided separately. For this reason, the detection position is fixed, and there is a problem in that accurate stripping errors cannot be detected when the thickness of the workpiece differs.

SUMMARY OF THE INVENTION An object of the present invention is to provide a punch press in which the stripping error detection position can be arbitrarily set according to the thickness of the plate without using a limit switch.

[Structure of the Invention] (Means for Solving the Problems) In view of the above problems, the present invention provides a lift spring that is biased to the upper limit position and a stripper spring that is pressed to the upper limit position after punching a plate material. a mold comprising a punch that is pulled out from a plate material by a pressurizer; a position detection unit that detects the vertical position of a ram that presses the punch; a main control unit that controls the stroke speed of the ram, and when the ram starts rising at high speed from the lowest position, after the ram temporarily separates from the punch near the lowest position, The apparatus further includes a stripping error detecting section which detects whether or not the punch and ram have come into contact with each other again and outputs a stripping error occurrence signal to the main control section when there is no re-contact signal.

(Example) Hereinafter, an example of the present invention will be described in detail based on the drawings.

In FIG. 2, a turret punch press machine 1 as a punch press machine has a frame 3, and inside and above the frame 3 there are an upper turret and a lower turret that rotate around a vertical axis (Z axis). They are arranged at predetermined intervals. A number of punches are attached to the upper turret at a plane (XY) position, and a number of dies are attached at a plane position of the lower turret facing the punches.

A cylinder device 5 equipped with a reciprocating ram is provided above the frame 3. The ram is disposed above the upper turret and presses a punch located below the ram toward the die. A Y-axis guide rail 7 is provided on the side surface of the frame 3. The Y-axis guide rail 7 is provided with a moving member guided in the Y-axis direction by a Y-axis servo motor, and a work table 9 equipped with a free bearing is fixed to the upper surface of the moving member.

A carriage 11 is provided at the Y-axis end of the work table 9 and is movable in the X-axis direction by an X-axis servo motor. The carriage 11 carries a plate material W placed on the work table 9.
A plate material clamping device is provided that grasps the plate material W and guides the plate material W within the XY plane.

The turret punch press machine 1 having such a configuration guides the carriage 11 in the XY plane by means of the NC device 13 attached to the frame 3, and also drives the cylinder device 5 appropriately to form the plate material W.
A predetermined punching process can be performed at a predetermined position.

FIG. 1 is a block diagram of a control system showing an overview of the NC device 13 and an overview of the cylinder device 5 and its hydraulic circuit.

In FIG. 1, the cylinder device 5 is a cylinder 5.
A piston 5B is provided inside A, and a ram 5C that is freely movable and extends downward in the vertical direction (Z-axis) is integrated into the piston 5B.

Below the ram 5C, a plurality of upper mold guides 17 are attached to the circumference of the upper turret 15,
Each upper mold 19 is provided on the upper mold guide 17, and a punch 19A is provided inside the upper mold 19.

A lower turret 21 is provided below the upper turret 15, and a plurality of dies 23 are provided on the circumference of the lower turret 21 at positions corresponding to the upper die 19.

A plate material W is placed on the die 23, and the plate material W
On the side, there is a plate material clamping device 2 for gripping the plate material W.
5 is provided.

In this embodiment, strip misses can be detected by the configuration shown in FIG.

That is, a series circuit consisting of a DC power source E and a relay R is connected between the ram 5C and the die 23. In the figure, numeral 20 is a stripper spring for stripping the punch 19A from the plate material W, 22 is a lift spring that urges the plate holder 24 upward, and 26 is an insulating material.

A rolling wheel is attached to the ram 5 on the lower surface of the cylinder 5A.
The movement of the ram 5C is detected by a pulse signal.
A pulse encoder 27 that detects the PS is attached so that the stroke position of the chim 5C can be detected.

The hydraulic circuit 29 includes a hydraulic pump OP and a servo valve 3 connected to the upper cylinder chamber and lower cylinder chamber of the cylinder 5A via piping OL ₁ and OL ₂ .
1. Piping OL ₁ has an output detector 3 that detects the oil pressure of piping OL ₁ using an electrical signal.
3 is provided.

The NC device 13 includes an NC data input section 35, a main control section 37, an XY-axis command section 39, and a Z-axis command section 4.
1, position detection section 43, and servo valve control section 45
, a machining speed pattern storage section 47 , and a stripping error detection section 48 .

The NC data input unit 35 is in offline or online communication with CAD and CAM, and receives NC data for controlling the turret punch press machine 1 from the CAD and CAM.
The data is provided to the main control unit 37.

A machining speed pattern storage section 47 connected to the main control section 37 stores various machining speed patterns corresponding to the material and thickness of the plate material W.

Further, the strip misdetection section 48 detects the relay R
The occurrence of stripping errors is monitored by inputting the stripping error detection signal from (see FIG. 3). Moreover, the detection position is automatically set according to the thickness of the plate material W.

The main control section 37 is operated by the operating system, receives NC data from the NC data input section 35, and mainly controls the position of the plate material W.
Drive control of the cylinder device 5 is performed. or,
The main control section 37 is connected to various sensors, limit switches, and other various actuators, and controls the turret punch press machine 1 in general.

The XY-axis command section 39 receives predetermined position control data from the main control section 37 and drives the X-axis and Y-axis servo motors, thereby positioning the plate material W within the XY plane. .

The Z-axis command unit 41 receives Z-axis command data from the main control unit 37 and sets the position Zn, which is for driving the servo valve.
Outputs speed Vn data.

The position detection section 43 integrates the pulse signal PS output from the pulse encoder 27 and detects the current position Z of the ram 5C. The pulse encoder 27 is of a type that detects pulse signals of two phases that differ by 1/4 of the displacement, and the position detection unit 43 can also know the moving direction of the ram 5C based on the pulse signals PS of these two layers. .

The servo section control section 45 receives position data Zn and speed data Vn from the Z-axis command section 41, and also receives the current position Z of the ram 5C from the position detection section 43. Based on these input values, the servo valve control section 45 controls the servo valve 31 to a predetermined position and to a predetermined opening degree.

The machining speed pattern storage section 47 stores machining speed patterns as shown in FIG. 4, for example.

In Figure 4, the horizontal axis is time, and the vertical axis is ram 5C.
A curve V, which is an example of a machining speed pattern, is shown. Ram position Z ₁ is ram 5
The ram 5C is machined by accelerating at an acceleration α ₁ from the ram position Z ₁ (point V ₁ ), which is the rising end position, and reaches the ram position Z ₂ at time T ₂ .
Reach V ₂ (approach section).

When the ram 5C reaches the point V ₂ , the acceleration α ₂ (α ₂ <
α ₁ ) and reaches point V ₃ at ram position Z ₃ at time T ₃ . That is, the point _V3 position is referred to as a contact point, and indicates the position where the lower surface of the upper die guide 17 abuts the upper surface of the plate material W placed on the die 23.

Then, before moving from point _V3 to point _V4 , the plate material W is punched with the punch 19A.

The punching process is performed up to point V ₄ , and the ram 5C from time T ₄ to time T ₇ is accelerated by acceleration α ₃ (α ₃ > α ₂ ) and moves up to the rising end position of ram position Z ₁ ( Point _V5 )
will be returned to.

In this way, the machining speed pattern storage unit 47 stores machining speed patterns corresponding to various materials of the plate material W and changes in the plate material.
By specifying the material and thickness of the plate material to be punched, a machining speed pattern suitable for the plate material W can be appropriately selected. This results in
It is possible to reduce vibration noise during punching.

Next, the stripping error detection operation will be explained.

FIG. 5 shows the stripping error detection signal detected by the stripping error detection section 48.

As understood from Figure A, the contact point where the tip of the punch 19A comes into contact with the plate W
At _V3 , the relay coil L shown in FIG. 3 is energized.
This energized state is maintained until the lowest position _Z4 of the ram 5C.

When the punching downward movement is completed and the ram 5C rises, the punch 19A returns to its original position due to the stored force of the strip spring 20, but the return speed is lower than that of the ram 5C.
It follows the ram 5C somewhat later than the rate of rise of the ram 5C, tracing a trajectory as shown by the dashed line (arrow A) in FIG. Therefore, the lower end of the ram and the upper end of the punch are separated from each other, and the energization is cut off (time T ₄ →T ₅ ).

Then, when the upper end of the punch comes into contact with the lower end of the ram again, energization is started again and connection is established up to the contact point (time T ₅ →T ₆ ).

When the tip of the punch separates from the plate material W, the electricity is completely cut off and the ram returns to its maximum limit (with time
T ₆ →T ₇ ).

The above is the stripping error detection signal in a normal state where no stripping error occurs.

Here, if a strip error occurs,
The punch 19A cannot escape from the plate material W, and the relay coil L is not energized again between time _T5 and _T6 , as shown in FIG. 5B.

As a result, a stripping error occurrence signal is output from the stripping error detection section 48 to the main control section 37. The main control unit 37 then controls the XY-axis command unit 39
A control command is output to stop the movement of the plate material W. At this time, the operator may be notified of the occurrence of a stripping error using a warning means such as a lamp, and the operation of the apparatus may be stopped.

In this manner, it is possible to detect whether or not a stripping error has occurred by detecting whether or not the lower end of the ram and the upper end of the punch separate during the upward movement of the ram 5C and come into contact with each other again.

On the other hand, when the plate thickness d of the plate material W changes, the acceleration α ₂ is changed to a desired value in accordance with the plate thickness d so that low-vibration and low-noise punching can be performed. At the same time, the stripping error detection position is automatically set according to the plate thickness d.

This makes it possible to detect stripping errors more accurately in accordance with the plate thickness d, compared to the fixed position detection of stripping errors using a limit switch as in the conventional example.

[Effects of the Invention] As can be understood from the above description of the embodiments, in short, the present invention is such that the lift spring 22 is biased to the upper limit position, and the stripper spring 20 is A mold comprising a punch 19A that is pulled out from the plate W by a ram, and a ram 5C that presses the punch 19A.
A main control unit 37 that controls the stroke speed of the ram 5C according to the thickness of the plate material W and the detected vertical position of the ram 5C, Said ram 5
When C starts rising at high speed from _the lowest position _Z4 , the punch 1
stripping error detection for detecting whether or not the punch 19A and the ram 5C are in contact again after the ram 5C is temporarily separated from the punch 9A, and outputting a stripping error occurrence signal to the main control section 37 when there is no re-contact signal; 48.

As is clear from the above configuration, in the present invention, when the ram 5C ascends and returns from the lowest position at high speed, when the punch 19A punches the plate material W and descends, the lower end of the punch 19A The above punch 1 is tightened into the punched hole.
After the punch 19A and the ram 5C are temporarily separated from each other because the punch 19A cannot follow the return of the lift member 9A, the punch 19 is pulled out from the plate material W by the stripper spring 20 and raised, and then the punch 19 is lifted by the action of the lift spring 22. As the punch 19 is raised, the action of both springs 20 and 22 causes the punch 19 to rise rapidly and catch up with the ram 5C. By detecting that the punch 19 has contacted the ram 5C again, it is detected whether or not a stripping error has occurred. It is something that exists.

Furthermore, the present invention is configured to detect the vertical position of the ram 5C and to control the stroke speed of the ram 5C in accordance with the vertical position.

Therefore, according to the present invention, the speed of the upward return of the ram 5C is not so great that it cannot keep up with the upward movement of the punch 19, and is small enough that the punch 19 and the ram 5C are always maintained in a state of contact. Rather, it is possible to control the lifting speed to an optimum level, improve work performance, and ensure stripping errors can be detected.

[Brief explanation of the drawing]

Fig. 1 is a configuration diagram of an embodiment to which the present invention is applied, Fig. 2 is a perspective view of a turret punch press of the embodiment, and Fig. 3 is an explanatory diagram showing the configuration of stripping error detection in the embodiment. FIG. 4 and FIG. 5 are explanatory diagrams showing the operation of the same embodiment. 5C... Ram, 19A... Punch, 23... Die, 37... Main control section, 48... Stripping error detection section, E... DC power supply, R... Relay.

Claims (1)

[Claims] 1. A mold comprising a punch 19A that is urged to the upper limit position by a lift spring 22 and is pulled out from the plate material W by a stripper spring 20 after punching the plate material W, and a die for punching the punch 19A. a position detection unit 43 that detects the vertical position of the pressing ram 5C, and a main control unit 37 that controls the stroke speed of the ram 5C according to the thickness of the plate material W and the detected vertical position of the ram 5C.
When the ram 5C starts rising at high speed from the lowest position _Z4 , the lowest position _Z4
From the punch 19A to the ram 5C in the vicinity
After they are temporarily separated, the punch 19A and the ram 5
A punch press characterized in that it is equipped with a stripping error detecting section 48 which detects whether or not C has touched again and outputs a stripping error occurrence signal to the main control section 37 when there is no re-contact signal.