JPH07299528A - Method and device for inspecting die of punch press - Google Patents

Abstract

PURPOSE:To prevent the generation of a defective product by quantitatively inspecting the degree of the wear of the die of a punch press without removing the die. CONSTITUTION:When an upper die 5 is driven toward a material W to be worked by the hammer 7 of a punch press, a strain generated on the hammer 7 is detected by a strain sensor 10, and a strain generation time is measured by a strain generation time measuring means 15. The measured strain generation time is compared with a reference time to be determined by this upper die 5 and the material W to be worked by a judging means 17. When the measured strain generation time is larger than the reference time, the effect that this die reaches its use limit is displayed on the display device 18.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a die inspecting method and die inspecting apparatus for a punch press machine in which a die is punched by punching a die on a workpiece.

[0002]

2. Description of the Related Art In a punch press machine for continuously punching a work material such as a metal plate by driving a die, it is necessary to monitor the deterioration state of the die, which directly affects the quality of a processed product. . For this reason, conventionally, the mold is regularly removed from the press, or the worker examines the worn condition or crushed condition of the mold by using the finished condition of the processed product as a guide, and determines the wear condition according to the worn condition. Therefore, the die is subjected to polishing treatment, replacement treatment, and the like.

[0003]

However, in the method of inspecting the mold by actually seeing the finish of the mold or the processed product as described above, the method of inspecting the mold is not enough for the mold to be worn. Even if you do not remove it from the press machine,
There is an inconvenience that the wear state cannot be known. In particular, in a press machine having a large number of molds, it is necessary to spend a lot of time on such unnecessary removal work.

Further, in the method of checking the wear state of the mold by using the finish of the processed product as a guide, it should be noticed that the wear of the mold is advanced unless defects such as burrs and chips actually occur in the processed product. In many cases, this increases the possibility of producing a large number of defective products.

Further, since the periodical inspection of the mold and the inspection of the finish of the processed product are made by visual inspection of the operator,
There is a problem in that the judgment result varies greatly depending on the operator and stable mold management cannot be performed.

An object of the present invention is to solve this problem and to provide a die inspection method and a die inspection apparatus for a punch press machine capable of quantitatively knowing the wear state of the die. There is.

[0007]

In order to solve the above problems, a method of inspecting a die of a punch press machine according to the present invention is a die inspection method of a punch press machine in which a die is punched by punching a die into a work material. In the method, the generation time of strain that occurs when the mold is driven into a workpiece is measured, and the wear state of the mold is determined according to the length of the strain generation time.

The die inspection device for a punch press machine according to the present invention is a die inspection device for a punch press machine, in which a die is punched by punching a die on a workpiece by a hammer. , The strain of the hammer that occurs when the die is driven into the workpiece by the hammer is detected, and the strain sensor that outputs a signal corresponding to the strain, and the strain signal output from the strain sensor, And a strain time measuring means for measuring the generation time of the mold, and the wear state of the mold and the like can be determined by the length of the strain time measured by the strain time measuring means.

[0009]

The present invention has been made based on the experimental results that the strain generation time generated when a die is driven into a workpiece increases with the progress of wear of the die.

In the die inspection method of the present invention, the wear state of the die is known by measuring the strain time. Further, in the mold inspection apparatus of the present invention, by the strain sensor attached to the hammer for driving the mold into the work material, the strain during punching is detected, and the detected strain occurrence time is the strain time. It is measured by a measuring means.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing the configuration of a punch press machine equipped with the mold inspection apparatus of the present invention.

The frame 1 of this punch press is provided with a die support 2 for supporting a plurality of sets of dies so that any one of a plurality of types of dies can be sequentially selected and used. Has been. The mold support 2 is composed of a fan-plate-shaped upper substrate 3 and a lower substrate 4 which are vertically arranged with a gap between each other and whose center portions are connected to each other. And is supported so that it can rotate in a horizontal state.

A plurality of types of upper molds 5 are attached to the upper surface edge of the upper substrate 3 at predetermined intervals, and the upper surface of the lower substrate 4 is positioned immediately below each upper mold 5 of the upper substrate 3. A lower die 6 forming a pair with each upper die 5 is attached so as to do so.

When the upper die 5 receives a force from above, the upper die 5 descends toward the lower die 6 forming a pair, and when the force from above disappears, the original height is increased by the force of a spring (not shown) or the like. It is configured to return to the position.

The hammer 7 for driving the upper die 5 is
The upper die 5 is arranged above a predetermined position (which is a reference position) on the rotation path of the upper mold 5. The hammer 7 receives the force of the flywheel, hydraulic pressure, etc., and descends at high speed to drive the upper die 5 located immediately below it from above.

The plate-shaped workpiece W is supported substantially horizontally by a support table 8 which is movable in the XY directions on a horizontal plane. The support table 8 moves the workpiece W within the gap between the upper substrate 3 and the lower substrate 4, and sequentially positions the planned punching position to a reference position, that is, a position directly below the hammer 7.

Selection of mold (rotation control of mold support 2),
The control unit 9 performs positioning of the workpiece W to be punched at the reference position (movement control of the support table 8) and drive control of the hammer 7.

The control unit 9 drives the support table 8 to position the planned punching position of the workpiece W at the reference position, and the metal mold to be used at the planned punching position is directly below the hammer 7. The operation of rotating the die support 2 and then driving the hammer 7 is controlled according to a predetermined machining program so that each part is continuously controlled to perform punching on the workpiece W. .

The rotary drive mechanism of the die support 2, the descending mechanism of the hammer 7 and the moving mechanism of the support table 8 are well known in the art and will not be described in detail here.

On the other hand, a strain sensor 10 is fixed to the side surface of the hammer 7. The strain sensor 10 outputs a signal according to the magnitude of strain (mainly strain along the descending direction) generated in the hammer 7 during punching, and in particular, the strain gauge ratio (sensitivity of strain gauge) is large. A small and lightweight one is used.

Here, the relationship between the movement of the hammer 7 and the upper die 5 during punching and the signal output from the strain sensor 10 will be described with reference to FIG. As shown in FIG. 2A, after the hammer 7 starts descending, the upper die 5
Until the upper die 5 is pressed from above and comes into contact with the workpiece W, the output of the strain sensor 10 hardly changes, and the upper die 5 comes into contact with the workpiece W, From the time T0 when the work W begins to descend while shearing to the time T1 when the shearing is almost completed, the strain sensor 1
The output of 0 increases and the output of the strain sensor 10 decreases to the original state at T2 when the tip of the upper die 5 completely penetrates the workpiece W after the shearing is completed. The output of the strain sensor 10 hardly changes until the hammer 7 rises and the upper die 5 rises accordingly and returns to the original height position.

The inventor of the present invention has found that even when the material and thickness of the workpiece W or the diameter of the die itself are different, the strain generation time in the hammer 7 during punching depends on the degree of wear of the die. It can be obtained experimentally that the length is correspondingly longer.

The results of the experiment are shown below. In this experiment, as shown in FIG. 3, a hammer 7 of a punch press machine is used.
The strain sensor 10 is attached to, and the output of the strain sensor 10 is amplified by the amplifier 11 and then input to the data recorder 12 and the oscilloscope 13 so that the output of the strain sensor 10 during punching can be recorded and observed. Two types of dies (φ20, φ,
The workpieces having different thicknesses and materials were punched 25 times continuously by φ10), and the strain generation time of the output signal of the strain sensor 10 obtained at that time was measured on average.

The measured strain generation time is not only the total strain generation time Ta from the rising to the falling of the output waveform T0 to T2 of the output waveform shown in FIG. 2, but also the output waveform of the strain sensor 10. Was also measured at a half-value strain occurrence time Tb of ½ or more of the peak value, and an arrival time Tc from when the waveform rises to ½ of the peak value to when it reaches the peak value.

The measurement results obtained in this manner are shown in Tables 1 to 3 below for each material of the material to be processed.

[Table 1]

[Table 2]

[Table 3]

Further, FIG. 4 shows the output waveforms of the strain sensor 10 when the wear degree of the φ20 die of Table 1 is small, medium and large (note that in Tables 1 to 3,
For the φ10 mold, only the strain generation time is shown for those with low and medium wear.

As shown by the measurement results in Tables 1 to 3 and FIG. 4, even when the type and thickness of the work material or the diameter of the mold are different, the degree of wear of the mold is small. It can also be seen that the strain generation time when the degree of wear of the mold is large with respect to the strain generation time is long for Ta, Tb, and Tc, and this tendency is monotonically increasing.
Further, in this experiment, it was not possible to clearly obtain the dependence of the magnitude (peak value) of the output of the strain sensor 10 on the degree of wear of the mold.

In view of this, in this embodiment, the strain generation time of each die in a state where the degree of wear is small is measured for each workpiece in advance, and the measurement result serves as a criterion for determining the use limit of the die. Each reference time is obtained and stored, and it is determined whether or not the strain generation time measured from the output signal of the strain sensor 10 during operation exceeds the reference time.

That is, in this embodiment, as shown in FIG. 1, the strain generation time measuring means 15 for receiving the output signal of the strain sensor 10 and measuring the strain generation time, and for each die and the workpiece in advance. Reference time storage means 16 for storing reference time for each material and strain generation time measurement means 15
Strain occurrence time measured by the reference time storage means 16
Determination means 17 for determining whether or not the mold has reached the usage limit by comparing the reference time stored in
There is provided a display unit 18 for displaying the mold which has been determined by the determination unit 17 to have reached the usage limit.

The strain generation time measuring means 15 may measure any of the times Ta, Tb, and Tc described above, and as shown in FIG. 2, an intermediate value between Ta and Tb, that is, a strain sensor. The output from 10 is 1 / of the peak value.
It is also possible to measure the time Td from when a predetermined threshold value Vr smaller than 2 is exceeded to when the threshold value Vr becomes less than or equal to this threshold value.

Regarding the method of measuring the strain generation time, whether or not the output of the strain sensor 10 is higher than a threshold value is compared by a comparator, a gate pulse is opened by the output pulse of the comparator, and a clock pulse is passed through the gate. Various methods, such as a method of counting the number of the signals, sampling the output signal of the strain sensor 10 and converting it into digital data, temporarily storing it in a memory, and then measuring the width (time) of the signal with a microprocessor. It is possible.

The reference time stored in the reference time storage means 16 in advance is, for example, the strain generation time measured by the same method as the strain generation time measuring means 15 when the wear of each mold is small. A value obtained by multiplying a predetermined coefficient (for example, 1.5) is used, or the strain generation time Tr when the degree of wear is small, and the difference between the strain generation time Tr and the strain generation time which is the limit of use. ΔT is stored as a set of reference time data, and by determining whether or not the result of subtracting Tr from the strain generation time measured from the output of the strain sensor during operation is greater than ΔT, the money is calculated. The usage limit of the mold may be determined. The reference time is set in advance for all combinations of a plurality of molds and the material and thickness of the workpiece W.

The determination means 17 provides information indicating the type of die to be driven by the hammer 7 and the type of work material to the control unit 9.
From the reference time storage means 16, the reference time determined by the combination of the die and the workpiece is read out and compared with the strain generation time measured by the strain generation time measuring means 15, and the strain generation time is the reference time. When greater,
The information of the mold is displayed on the display 18 as the mold that has reached the limit of use.

The measurement and determination of the strain generation time may be performed each time the die is driven by a hammer, or may be performed each time a die is punched a predetermined number of times. It may be performed every time a predetermined time elapses.

In the punch press machine having the die inspection device configured as described above, while the punching process for the workpiece W is continued under the control of the control unit 9, the frequently used die wears. And the time of occurrence of strain generated in the hammer 7 when driving the die becomes longer than the reference time determined by the type of the die and the work material,
The information of this mold is displayed on the display 18.

Therefore, by looking at this display, the worker can know the die which has reached the limit of use without performing unnecessary work of removing the die, and before a large number of defective products are generated. In addition, the mold can be subjected to polishing processing and replacement processing.

[0037]

Other Embodiments In this embodiment, the strain sensor 1
Although the strain generation time measured from the output of 0 was automatically judged during operation whether or not it reached the usage limit, the latest strain generation time measured for each mold is displayed as it is. Displayed on the display, or the measured strain occurrence time is stored in a memory that can be read once, and read out from the memory when necessary by a worker's switch operation, etc., and displayed on the display. It may be made to print on such as. Even in this case, the operator can quantitatively know the degree of wear of each mold from the displayed strain occurrence time, so that the mold that needs polishing or replacement can be accurately known. be able to.

Further, in the above-mentioned embodiment, the present invention is applied to the punch press machine for punching by selectively using a plurality of dies, but the punch press machine using only one die continuously. The present invention can be similarly applied to the above.

[0039]

As described above, the method and apparatus for inspecting a die of a punch press according to the present invention detect a strain generated when a die is driven into a work material, and measure the strain generation time. Since it is possible to inspect the degree of wear of the mold, it is possible to quantitatively know the wear state of the mold without removing the mold from the press and inspecting it or checking the occurrence of defective products. It is possible to perform stable mold management.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an embodiment of the present invention.

FIG. 2 is a diagram showing the relationship between the movement of the mold and the output of the strain sensor.

[Fig. 3] Schematic diagram of the strain generation time measurement experiment

FIG. 4 is a diagram showing changes in the output signal of the strain sensor with respect to the degree of wear of the mold.

[Explanation of symbols]

 2 Mold support 5 Upper mold 6 Lower mold 7 Hammer 8 Support table 9 Control unit 10 Strain sensor 15 Strain generation time measurement means 16 Reference time storage means 17 Judgment means 18 Indicator W Workpiece

Claims (2)

[Claims] 1. A method for inspecting a die of a punch press, which comprises punching a die into a work material, the method comprising: measuring a strain generation time when the die is driven into the work material. A method for inspecting a die of a punch press machine, which comprises determining the wear state of the die according to the length of the strain generation time. 2. A die inspecting apparatus for a punch press, which punches a die into a work material by hammering the die into a work material, the die inspection device being attached to the hammer and driving the die into the work material by the hammer. Detects the strain of the hammer that sometimes occurs, and receives a strain signal output from the strain sensor, and a strain sensor that outputs a signal corresponding to the strain,
A punch press characterized by comprising a strain time measuring means for measuring a strain generation time, wherein the wear state of the mold can be determined by the length of the strain time measured by the strain time measuring means. Machine mold inspection device.