JP3312943B2 - 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 using a hydraulic cylinder as a press drive.

[0002]

2. Description of the Related Art Conventionally, in a punch press using a hydraulic cylinder as a press driving device, a method for controlling the position of the hydraulic cylinder is as follows. A method of controlling using a servo valve that can be controlled, speed control and position control of a hydraulic cylinder can not be performed, using a switching valve that simply changes the direction of fluid or closes the flow of fluid There is a way to control.

However, in the above method, the position control of the hydraulic cylinder can be stopped accurately such that the position of the hydraulic cylinder is 0.1 mm or less. Although it is not necessary to include the time element that led to the punch command timing, the servo valve is expensive, the control is complicated, and since it is a precision valve, there is a problem that the cost for managing the hydraulic oil increases.

[0004] In the above method, the control of the hydraulic oil is easy and the cost is low, but the variation in the stop position of the hydraulic cylinder is large. This means that the distance from the stop position of the hydraulic cylinder to the contact of the upper mold with the workpiece has a large variation, and the timing of the punch command sent before the completion of the positioning of the workpiece has the largest distance. The timing must assume a short case, and at the above timing, when stopping at a position where the distance is long, a loss time occurs between completion of positioning of the workpiece and contact of the upper mold. There is a point.

[0005]

SUMMARY OF THE INVENTION In view of the above-mentioned prior art, the present invention uses a switching valve of the type described above and absorbs the variation in the stop position, which is a drawback of the switching valve, so that a loss time during punch press processing is reduced. It is an object of the present invention to provide a method capable of controlling a punch press without using the same.

[0006]

SUMMARY OF THE INVENTION The present invention has been made for the purpose of solving the above-mentioned problems, and comprises a mold holding device for mounting one or more pairs of upper and lower dies. A positioning device that positions a workpiece with respect to a desired pair of the upper mold and the lower mold, and a hydraulic cylinder that presses the upper mold in a vertical direction in order to press the workpiece. A press drive device provided with a switching valve for performing reciprocating operation and stop of the hydraulic cylinder, sends a punch command to the press drive device before completion of positioning of the workpiece, and lowers the upper mold. After performing press working on the work material by interaction with the lower mold, the hydraulic cylinder is stopped at a position where there is no problem in moving the work material to the next processing position and positioning. Upper die for punch press machine After pressing and press working the work material, the hydraulic cylinder is stopped for each punching process until the work cylinder is stopped at a position where it does not hinder the movement of the work material to the next processing position. The press position is detected at a timing including a time element derived from the relationship between the operating distance of the hydraulic cylinder and the speed of the hydraulic cylinder from the detected stop position to the contact of the upper mold with the workpiece from the detected stop position. A punch command is transmitted to the driving device.

[0007]

[Operation] In other words, the present invention detects the stop position of the hydraulic cylinder for each punching process, and calculates the operating distance of the hydraulic cylinder from this stopped position until the upper mold contacts the workpiece. The timing of a punch command including a time element derived from the relationship between the operating distance and the speed of the hydraulic cylinder is transmitted at each punching step, so that the occurrence of loss time is suppressed as much as possible. It worked efficiently.

[0008]

Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a longitudinal sectional front view showing a state of a press driving device when moving and positioning a workpiece of a punch press according to the present invention, FIG. 2 is a diagram showing a hydraulic circuit and a control block of a press driving unit, and FIG. FIG. 4 is a vertical sectional front view showing the state of the press driving device in contact with the workpiece, and FIG. 4 is an explanatory diagram showing the conventional punch command transmission timing and hydraulic cylinder operation.
FIG. 4 is an explanatory diagram showing a transmission timing of a punch command and an operation of a hydraulic cylinder in the present invention.

In FIGS. 1 and 2, reference numeral 1 denotes a main body frame of a punch press, which includes a hydraulic cylinder 2, a piston 2a disposed therein, and a ram 3 connected to the piston 2a and slidable in a vertical direction. And a press driving device constituted by a ram head 4 connected to the ram 3 is vertically moved to an upper mold 31.
It is mounted so as to press the punch assembly PA including.

Reference numeral 5 denotes a detecting device for detecting the stroke position of the ram 3. In this embodiment, a potentiometer is used, and a detecting direction of the ram 3 and a detecting rod 6 which is inserted into the detecting device 5 and which can be freely moved forward and backward. Are fixed to the hydraulic cylinder 2 so that the sliding directions are the same.

Reference numeral 7 denotes a sensor head mounted on the distal end of the detection rod 6, which is urged by a spring 8 and has a dog 9.
Is in contact with Reference numeral 10 denotes a guide rod, which is guided by the hydraulic cylinder 2 and serves to prevent rotation of the ram 3 and to transmit the vertical movement of the ram 3 to the dog 9. A connecting block 11 connects the ram 3 and the guide rod 10 and is fixed to the ram and also connected to the guide rod 10.

Reference numeral 12 denotes a punch turret on which a pair or a plurality of pairs of punch assemblies PA are mounted, and which is rotatably supported by a bearing device (not shown) arranged on the main body frame. The punch assembly PA is inserted into the punch turret 12, and the guide post 14
And the spring guided by this guide post 14
It is lifted up by the tool lifter 15 and the tool lifter 13, and the upper limit is regulated.

Reference numeral 16 denotes a die turret, which is a punch assembly.
A die 17 as a lower mold paired with the PA is arranged, and is rotatably supported by a bearing device (not shown) arranged on the main body frame 1. Thus, a punch press machine is constituted.
In the drawing, W is a workpiece which is positioned between the punch assembly PA and the die 17 by a positioning device (not shown) and subjected to punching.

FIG. 2 is a hydraulic circuit diagram and a control block diagram for explaining a press drive section for driving the punch press machine. The hydraulic circuit 18 includes an upper chamber A and a lower chamber A of the hydraulic pump OP and the hydraulic cylinder 2. An electromagnetic switching valve 19 is connected to the chamber B via pipes PL ₁ and PL ₂ .

A control unit 20 controls the positioning of the workpiece W, the selection and positioning of the die mounted on the punch turret 12, and the control of an electromagnetic switching valve 19 for reciprocating and stopping the hydraulic cylinder 2. The punch assembly PA comes into contact with the workpiece W based on the plate thickness Wt of the workpiece W input to the NC data input unit 21 and the intermediate stop position detection data 22 of the ram 3 during punching. The operating distance of the hydraulic cylinder 2 is calculated, and a punch command including a time element derived from the relationship between the calculated value and the speed of the hydraulic cylinder 2 is sent to the electromagnetic switching valve 19 for control.

The speed Vz of the hydraulic cylinder 2 is controlled in advance by a control unit.
One or a plurality of settings are made in 20. The speed at which the hydraulic cylinder 2 is operated may be input through the data input unit 21 or may be automatically set by the control unit 20.

Reference numeral 23 denotes a flow rate switching valve, and the speed of the hydraulic cylinder 2
It is attached when a plurality of Vz are set, and is controlled by a command from the control unit 20 so that the speed Vz of the hydraulic cylinder 2 becomes the commanded speed.

FIG. 3 shows a state in which the punch assembly PA is in contact with the workpiece W, and the ram head 4 is mounted on the workpiece W of FIG.
From the state at the time of positioning a distance Z ₁ is moving downward. Therefore, since not may spend time positioning of the workpiece W until this state, the operation delay and constant lag amount and the moving time of the moving distance Z _1, such as a relay of the solenoid switching valve 19 If the punch command is sent before the positioning is completed, there is almost no loss time, and the operation is continuous.

[0019] Therefore, when the stop position the hydraulic cylinder 2 varies in the state of FIG. 1, since the moving distance Z ₁ is variable, the moving distance from the speed Vz of the moving distance Z ₁ and the hydraulic cylinder 2
Lead time required for the movement of Z _1, this time element and by adding a constant lag components such operation delay and the relay of the solenoid switching valve 19, is controlled to deliver a punch command before completion position, Continuous press working with little loss time can be performed.

FIG. 4 is a diagram for explaining the conventional punch command transmission timing and the operation of the hydraulic cylinder 2.
The operation delay and constant lag time, such as a relay of the solenoid switching valve 19, T ₁ is travel time derived from the speed Vz moving distance Z ₁ and the hydraulic cylinder 2, Z ₂ is the hydraulic cylinder 2 above from Z ₁ The distance traveled until the punch assembly PA comes into contact with the workpiece W when stopped, and P is the travel distance of the punch assembly PA between the workpiece W
L is a line for explaining the positioning operation of the workpiece W.

[0021] Now, when the movement distance of the hydraulic cylinder 2 is Z _1, a punch command, T from completion of positioning of the workpiece W +
If sent at the timing of T ₁ minute before, loss time without, but operation is lead to continuous, if the hydraulic cylinder 2 is stopped above the Z _1, the moving distance of the hydraulic cylinder 2 is Z ₂ So, in the same way as above,
When delivered in T + T ₁ minute before the timing, the punch assembly PA is the time to contact with the workpiece W, the moving distance becomes longer by T ₄ than in Z _1, it is the T ₄ as added time occurs.

If the above-mentioned prior art is controlled according to the present invention, the following is achieved. That is, FIG. 5 shows the operation of the transmission timing and the hydraulic cylinder 2 of the punch command in accordance with the present invention, the T ₁ as a variable T _11, T _12, commensurate with the stop position Z ₁ and Z ₂ of the hydraulic cylinder 2 If a punch command is sent before the positioning is completed during the time of T + T ₁₁ and T + T ₁₂ , the operation can be continuously performed without any loss time.

Therefore, in a punch press machine which presses the upper die by the action of the hydraulic cylinder, the stop position of the hydraulic cylinder stopped after the end of one punching step is detected for each punching step, and the workpiece is processed. The punch command to be sent to the next processing position before the completion of positioning is determined by adding a time constant derived from the relationship between the operating distance and the speed of the hydraulic cylinder to the delay constant of an electromagnetic switching valve, a relay, etc. By sending the hydraulic cylinder every punching process, the variation in the stop position of the hydraulic cylinder is absorbed, and continuous punch press processing without loss time can be performed.

[0024]

The present invention is as described above. According to the method of the present invention, the management of hydraulic oil is easy and the cost is low, and a simple and inexpensive switching valve such as an electromagnetic switching valve is used. Even if it is used, efficient punch press processing that minimizes the loss time during processing becomes possible.

[Brief description of the drawings]

FIG. 1 is a vertical sectional front view showing a state of a press drive device when a workpiece is moved and positioned in a punch press machine according to the present invention.

FIG. 2 is a diagram showing a hydraulic circuit and a control block of a press drive unit.

FIG. 3 is a vertical sectional front view showing a state of the press driving device in a state where an upper mold is in contact with a workpiece;

FIG. 4 is an explanatory diagram showing a conventional punch command transmission timing and an operation of a hydraulic cylinder.

FIG. 5 is an explanatory diagram showing a punch command transmission timing and an operation of a hydraulic cylinder according to the present invention.

[Explanation of symbols]

 Reference Signs List 1 body frame of punch press machine 2 hydraulic cylinder 2a piston 3 ram PA punch assembly 5 ram stroke position detection device 12 punch turret 16 die turret 17 die (lower die) 18 hydraulic circuit 19 solenoid switching valve 20 control unit 21 data input unit 22 Ram stop position detection data 23 Flow switching valve

Continuation of the front page (56) References JP-A-5-131297 (JP, A) JP-A-1-266997 (JP, A) JP-A-4-270100 (JP, A) JP-A-4-84699 (JP) , A) JP-A-3-189023 (JP, A) JP-A-2-255299 (JP, A) JP-A-63-66521 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB Name) B21D 28/00 B21D 28/20 B21D 28/24 B21D 28/36 B30B 15/16

Claims (1)

(57) [Claims] 1. A mold holding device for mounting one or more pairs of upper and lower dies, and a positioning device for positioning a workpiece with respect to a desired pair of the upper and lower dies. ,
A press drive device comprising a hydraulic cylinder for vertically pressing the upper mold in order to press the workpiece and a switching valve for performing reciprocating operation and stopping of the hydraulic cylinder; Before the positioning of the workpiece is completed, a punch command is sent to the press drive device, and the upper die is lowered to perform press working on the workpiece by interaction with the lower die. In a punch press machine in which the hydraulic cylinder is stopped at a position where it does not hinder movement and positioning at the processing position, after the upper die is pressed and the workpiece is pressed, the workpiece is The stop position of the hydraulic cylinder is detected every punching process until the hydraulic cylinder is stopped at a position where there is no problem in moving and positioning to the next processing position, and the upper die is covered from the detected stop position. Until it comes into contact with the processed material At a timing including a time element derived from the relationship between the operating distance of the pressure cylinder and the speed of the hydraulic cylinder, a punch command is issued to the press driving device so that the upper die reaches the workpiece when positioning of the workpiece is completed. A continuous punch press process that does not cause a loss time due to variations in the stop positions of the hydraulic cylinders in each punching process.