JPH10192989A - Warning system of defective bending angle of article in metal plate bending device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a system which detects a defective bending angle of a work without requiring sampling inspection, etc., and which warns it to a person in charge in a metal plate bending machine of a press brake, etc. SOLUTION: A D-value of a prescribed bending article, and each output value where the regular final pressures pa, pb of up and down driving cylinders 3a, 3b of a moving table 2 attached with a die D are detected with each pressure sensor 4 in the working time are received and stored in an NC controller 5, when these values of each article are not reached to the regular values in the real bending time, the composition is made so that the worker is warned.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for detecting the occurrence of a product having an incorrect bending angle in a plate workpiece bending apparatus and alerting a worker in charge.

[0002]

2. Description of the Related Art For example, in the case of a press brake or the like as a typical example of a conventional plate material work bending apparatus, when the same product is repeatedly bent from a plurality of sheet metal work materials, a predetermined number of the products are required. A check was made by periodically measuring whether or not the bending angle of the product was correct by a punching inspection.

FIG. 4 shows a conceptual diagram of an example of a conventional press brake of this type.

In FIG. 4, 1 is a fixed upper table, 2 is a movable lower table, and P / D is an upper / lower table.
3 shows a punch / die as each bending mold mounted on the lower table 1/2. Reference numerals 3a and 3b denote a pair of hydraulic cylinders (rams) for lower table raising / lowering driving for bending the work material W by raising the lower table 2.

With the above-described configuration, conventionally, a bending angle measuring device for a product is provided on a press brake as described above, and this angle is periodically measured by a sampling inspection.
It was input to an NC (numerical control) device and displayed.

[0006]

However, in the above-mentioned periodic sampling inspection method, it is necessary to measure the bending angle of the product each time, and the work efficiency is poor. Had worsened.

Further, the angle measuring device is relatively expensive, and there is a problem in its measurement accuracy.

The present invention has been made in view of the above-described conventional aspects, and does not require a periodic sampling inspection as in the related art, but requires a bending angle caused by a change in the thickness of a work material, a change in tensile strength, and the like. An object of the present invention is to provide a means for alerting an operator of an abnormality (defectiveness) of a processed product that warns the operator by detecting the change in the ram pressure for the die pressurization.

[0009]

Therefore, according to the present invention, in a plate bending apparatus, a pressure detecting means for detecting a final bending driving pressure at a predetermined bending angle of a predetermined product, Storage means for storing a predetermined normal drive pressure value, pressure comparison means for comparing the final bending drive pressure value and the stored predetermined normal drive pressure value at the time of individual bending of the product, In the comparing means, the individual final bending drive pressure values are:
The object is achieved by providing a product bending angle defect warning system of a plate bending apparatus, comprising: an alarm unit for issuing a warning when the stored normal driving pressure value does not reach. What you want to do.

[0010]

According to the system of the present invention as described above, it is possible to automatically detect a bending defect and issue an alarm to a worker without requiring periodic sampling inspection / measurement as in the related art. Therefore, the workability and productivity can be improved.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on an embodiment.

[0012]

【Example】

(Structure) FIG. 1 is a schematic view (a) of an embodiment in which the present invention is applied to the press brake shown in FIG. 4, and the bending angle of the workpiece W is a predetermined value at the final stroke of the bending step. For example, an essential part enlarged schematic view (b) at 90 ° is shown.

In FIG. 1, the same (corresponding) components as those in FIG. 4 are denoted by the same reference numerals. Overlapping,
1/2 is a pair of upper / lower tables, and 3a / 3b is a pair of hydraulic cylinders (rams) for raising / lowering the lower table 2.

The feature of the embodiment of the present invention is that, as shown in FIG. 1 (a), each pressure sensor for detecting a respective bending working pressure pa, pb is provided in a cylinder chamber below a piston of each hydraulic cylinder. 4 to connect the respective output values to the press brake numerical control (NC) device.

In FIG. 1B, the dimension "D value"
Means the distance between the tip of the punch P and the bottom of the die D at the time of the final stroke of bending.

(Operation) The detection of a product bending defect and the alarm operation sequence of this embodiment prior to the start of production processing are performed at the time of "test bending" of the first workpiece W and "final bending" of the second and subsequent workpieces. FIG. 2 showing each flowchart at the time of ""
And FIG.

Here, the normal bending angle of the work W is 90
Assuming that the angle is 0 °, first, at the time of the trial bending of the workpiece in FIG. 2 (step S1), trial bending is performed in step S2, and the trial bending is repeated until the predetermined angle of 90 ° is obtained. D value which is the distance between punch P and die D when 90 ° is obtained (FIG. 1 (b))
And the respective output values pa and pb of the two pressure sensors 4 of the cylinders 3a and 3b at that time are input to the memory of the NC control device 5 and stored.

Next, at the time of the main bending of the work shown in FIG. 3 (step S4), when the lower table 2 is driven up in step S5, it is determined whether or not the D value has reached the predetermined value in step S6. And step S5 is repeated until a predetermined value is reached, and then step S7
Detects the pressure values pa and pb of both cylinders 3a and 3b.

Whether or not the sum of these pressure values (pa + pb) has reached the pressure value stored and stored in the NC unit 5 is compared in step S8.
The processing product is determined to be OK, and if it has not reached this, a predetermined alarm such as sound or light is issued in step 10 to operate to warn the operator.

(Other Embodiments) In the above embodiment, the case of the embodiment of the lower table movable press brake has been described. However, the present invention is not limited to this. Of course, there is no problem.

It is also clear that the number of table driving cylinders is not limited to the two shown in the figure.

[0022]

As described above, according to the present invention,
Incorrect bending angle of the work in the sheet metal bending machine
Since it is possible to detect and warn the worker without performing the measurement by the periodic sampling inspection as in the related art, the workability and productivity can be improved.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a configuration of a press brake according to an embodiment (a) and an enlarged schematic diagram of a main part (b).

FIG. 2 is an operation sequence flowchart at the time of work trial bending.

FIG. 3 is a flowchart of an operation sequence at the time of main bending of a work.

FIG. 4 is a conceptual diagram of an example of a conventional press brake.

[Explanation of symbols]

 1 Upper table (fixed type) 2 Lower table (movable type) 3a, 3b Hydraulic cylinder 4 Pressure sensor 5 NC controller D Die P Punch W Work (material / product)

Claims (1)

[Claims] 1. A pressure detecting means for detecting a final bending driving pressure at a predetermined bending angle of a predetermined product in a sheet bending apparatus, and a storage means for storing a predetermined normal driving pressure value at the predetermined bending angle. Pressure comparison means for comparing the final bending drive pressure value during the individual bending of the product with the stored predetermined normal drive pressure value; and in the comparison means, the individual final bending drive pressure value Alarm means for issuing a warning when the stored normal driving pressure value does not reach the stored normal driving pressure value.