JPH0615369A - Press brake - Google Patents

Abstract

PURPOSE:To prevent products from lowering in yield and to improve work efficiency by informing a worker that a bending angle is varied, through the change in pressure by which a punch and a die are actuated at the time of the bending of a sheet material, and detecting abnormality before the bending angle is extremely varied. CONSTITUTION:A pressurizing force to actuate on a ram, which is measured by a pressure sensor at the time of the bending of the sheet material, and a normal pressurizing force at the final processing position of the ram are compared by a comparator part 29 ; whether or not the pressurizing force measured by the pressure sensor 29 is a normal value is confirmed by a confirming part 35 for an abnormal pressurizing force; the worker is informed of the pressurizing force being abnormal by an alarm display part 37 ; and a check for processing conditions is required. Also, if the pressurizing force is not an abnormal value, bending is continued for the sheet material.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a press brake for bending a plate material, and more particularly to an alarm display function for warning an operator to make a correction when the bending angle of the plate material is abnormal.

[0002]

2. Description of the Related Art Conventionally, a press brake for bending a plate material always balances a long ram against a fixed table when the long ram facing the fixed table is brought close to the work. It is necessary to move it while keeping it at. Further, the confirmation work as to whether or not the ram is moving in equilibrium is performed by the operator examining the angle of the bent product.

For this reason, if the confirmation work is neglected, the press brake may produce a large amount of defective products whose bending angle is changed.

Therefore, as a means for keeping the bending angle of the plate material constant without lowering the working efficiency, the position of the ram is corrected by controlling the oil temperature change of the hydraulic mechanism that governs the operation of the long ram.

[0005]

However, in the case where the position correction of the final machining position of the ram is not appropriate, even if the bending angle of the plate material is largely deviated, unless the operator investigates the bending angle of the product, It is not possible to know the deviation of the bending angle. Also, since the press brake does not display an alarm until the pressure limit of the mold is reached, a large number of defective products are produced.

Therefore, in order to solve the above-mentioned problems, the present invention is provided with a detection means for detecting an abnormality in the bending angle of the product without the operator having to investigate the bending angle of the product, and the bending means detects the bending angle. When an angle is detected to be abnormal, it is an object of the present invention to request the operator to notify the abnormality and make an appropriate correction to reduce the yield of products and improve work efficiency.

[0007]

In order to achieve this object, the present invention moves either the upper die or the lower die and is sandwiched between the upper die and the lower die. In a press brake that bends a plate material, pressure measurement to measure the pressing force at the final processing position of the ram that is integrally provided with either the upper die or the lower die and is driven at a predetermined speed during bending Means, a comparing section for comparing the pressure force measured by the pressure measuring means with the regular pressure force at the final processing position of the ram, and the pressure force measured by the pressure measuring means is the allowable pressure force. An abnormal pressing force confirmation unit for confirming that the pressing force is out of the range of values and an alarm display unit for notifying the operator that the pressing force is abnormal and requesting a check of the processing conditions are provided.

[0008]

According to the above construction, the pressure applied to the ram measured by the pressure measuring means at the time of bending the plate material and the normal pressure applied at the final processing position of the ram are compared by the comparison unit,
The abnormal pressure confirmation section confirms whether the pressure measured by the pressure measuring means is an abnormal value or not, and requests the operator to check that the pressure is abnormal and the processing conditions on the alarm display. . If the pressing force is not an abnormal value, the press brake continues bending the plate material.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments according to the present invention will be described below with reference to FIGS.
It will be explained based on.

FIG. 1 is a side view of a press brake 1 according to the present invention. The press brake 1 is provided with a die 5 as a lower die below the frame 3, and a punch 7 as an upper die on the upper side facing the die 5 and a punch holder 9 for holding the punch 7, and a punch holder 9 for holding the punch 7. It is provided via a pressure sensor 11 which is a pressure measuring means housed inside. The punch 7 is integrally connected to a ram 15 which is driven up and down by a cylinder 13. Above the ram 15, the servo valve 1 which supplies the pressure oil to the cylinder 13 by giving an appropriate throttle to the pressure oil supplied from the pump (not shown).
7 is provided. A control box 19 is provided above the frame 3, and a control device 21 that controls the operation of the press brake 1 is provided in the control box 19.

A process of bending the plate material by the press brake 1 having the above structure will be described with reference to FIG. In step 301, the operator inputs data such as the type of plate material to be bent, the plate thickness and the bending length, and performs initial setting. When the initial setting is completed, a bending work command is issued (step 303), and the press brake 1 performs bending (step 305). In step 307, simultaneously with the bending process, the force generated by the bending process is measured by the pressure sensor 11 sandwiched between the punch 7 and the ram 15 (hereinafter referred to as a measured value). In step 309, arithmetic processing is performed to find the difference between the measured value and the set value that is the normal cylinder 13 pressure at the target position of the ram 15, and this is taken as the deviation. In step 311, the deviation is compared with the allowable value of the set value. If the deviation is larger than the allowable value, the process proceeds to step 313, and the operation of the press brake 1 is stopped, and an alarm display requesting correction of the processing conditions is displayed. If the deviation is within the allowable value, the bending process is continued. In step 315, it is determined whether or not all the bending processings of the plate material to be processed have been completed. If the bending processings of all the plate materials have not been completed, steps 305 and thereafter are repeated, and if completed. The bending process of the plate material ends.

As shown in FIG. 3, the pressure sensor 11 is provided between the punch 7 and the ram 15. Pressure sensor 11
Is a piezoelectric element that converts a force generated during bending of a plate material into an electric signal. That is, the ram 15 is moved to the vicinity of a predetermined bending end position (a downward direction in FIG. 3) while sandwiching a plate material (not shown) between the punch 7 and the die 5 and the plate material is sandwiched. When the ram 15 is stopped, a force is applied to the piezoelectric element, which converts the force into an electric signal.

The control device 21 of the press brake 1 will be described below with reference to FIG.

The control device 21 has a measurement value input section 23 for inputting the measurement value from the pressure sensor 11 to the control device 21 via an A / D converter (not shown). The measured value input unit 23 is a measured value storage unit 25 that temporarily stores measured values.
Connected with. The measured value storage unit 25 and a reference pressure for the operator to set a regular cylinder pressure at the target position of the ram 15 in consideration of the plate material processing conditions (for example, plate material type, plate thickness, bending length, etc.). The setting unit 27 is connected to the comparison unit 29 that compares the deviation with the allowable value of the set value.

In the measured value storage unit 25, when the cylinder pressure at the target position is a normal cylinder pressure, the ram 15 stops at a predetermined position without any correction and a highly accurate folding is performed. Bending is performed.

The comparison unit 29 converts the deviation signal into the moving speed of the ram 15 when the measured value is within the allowable value, and the measured value is not within the allowable value. In this case, it is connected to the abnormal pressing force confirmation unit 35 for confirming the abnormal signal. The abnormal pressing force confirmation unit 35 is connected to an alarm display unit 37 for notifying the operator that the correction is not appropriate.

The deviation signal conversion unit 31 is connected to the ram speed control unit 41 together with the ram speed setting unit 39 for setting the moving speed of the ram 15 whose target position is the final processing position of the ram 15 for bending the plate material at a regular angle. Has been done.

The ram speed control unit 41 reads the speed control signal of the ram 15 detected by the pressure sensor 11 according to the current position of the ram 15 from the ram speed setting unit 39,
The valve opening / closing of the servo valve 17 is controlled via the servo valve drive unit 43.

The reference pressure setting unit 27, the alarm display unit 37, and the ram speed setting unit 39 are connected to a display control unit 45 for the operator to input various conditions.

As described above, the pressure sensor 11 detects that the bending angle of the plate material has changed, and notifies the operator of the change, thereby reducing the product yield and improving the work efficiency without producing a large amount of defective products. be able to.

The present invention is not limited to the above-described embodiments, but the present invention can be implemented in modes other than the above-mentioned embodiments.

[0022]

As described above, according to the present invention, the pressure acting on the ram when the plate material is bent is measured,
It detects that the bending angle has changed, notifies the operator with an alarm display, and requests appropriate correction.

Therefore, since it is possible to detect the abnormality before the bending angle of the plate material changes extremely, it is possible to reduce the product yield and improve the work efficiency.

[Brief description of drawings]

FIG. 1 is a side view showing a press brake of the present invention.

FIG. 2 is an explanatory view showing the mounting of the pressure sensor used in FIG.

FIG. 3 is a block diagram of a control device of the present invention.

FIG. 4 is a flowchart of a bending process according to the present invention.

[Explanation of symbols]

 1 Press Brake 5 Die (Lower Die) 7 Punch (Upper Die) 11 Pressure Sensor (Pressure Measuring Means) 15 Ram 29 Comparison Section 35 Abnormal Pressurization Confirmation Section 37 Alarm Display Section

Claims (1)

[Claims] 1. In a press brake for bending a plate material sandwiched between the upper mold and the lower mold by moving either the upper mold or the lower mold, the upper mold at the time of bending, Pressure measuring means for integrally measuring the pressing force at the final processing position of the ram which is integrally provided with one of the lower molds and is driven at a predetermined speed, and the pressing force and the ram measured by the pressure measuring means. Comparing section for comparing the regular pressing force at the final processing position with, and an abnormal pressing force checking section for confirming that the pressing force measured by the pressure measuring means is outside the range of the allowable value of the regular pressing force. And a alarm display section that informs the operator that the pressing force is abnormal and requests a check of the processing conditions, and a press brake.