JPH0724960B2 - Press machine - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a press device equipped with a shavings detecting device.

Conventional technology Conventionally, the position of the stripper is detected by the position sensor to detect the scraps in the press machine. The shortest distance from the position sensor when the upper die set reaches the bottom dead center. Was picked up, and the press drive power was turned off if there was an abnormality by comparison with the distance sampled before that. A conventional press die device in a state of reaching a bottom dead center position is shown in FIGS. 3, 4, and 5.

FIG. 3 shows a press die device that performs hole punching in a normal state. A position sensor 1 is fixed on the upper surface of the die plate 13 so as to face the stripper 23. Further, the die plate 13 is fixed to the lower die set 17 by a known method, and each of them is provided with a predetermined hole so that the punching punch 14 penetrates and the scraps fall. Punch punch
A punch plate 12 and an upper die set 19 which fixes the punch plate 12 by a known method are fixed. The stripper 23 is fitted in a stepped hole provided in the upper die set 19 and is hung by a hanging bolt 18 having a head shape capable of moving up and down for a predetermined period, and the work 15 is moved downward. It is pressed downward by a stripper spring 16 having a sufficient load to press and fix it. When the upper die set 19 reaches the bottom dead center, the work 15 is pressed as shown in FIG. The stripper spring 16 is compressed so as to escape upward. FIG. 4 is a diagram showing a state where the stripper 23 is tilted at the bottom dead center when the residue 21 is present. A plurality of position sensors 1 are normally arranged at diagonal positions of the die plate 13, and the shortest distance from the stripper 23 in FIG. 4 in the scraping state to the shortest distance to the stripper 23 in the normal state in FIG. By comparing
It is designed to detect abnormalities.

FIG. 5 is a view in which the punch 14 is changed to the bending punch 22 as compared with FIG. 3, and the die plate 13 is changed into a hole shape for bending the work 15. In addition, when performing bending work, the stripper spring 16 alone is sufficient because the lateral displacement stress of the work piece 15 is large compared to the punching work and the pressing force is required to accurately output the bending angle. First, the bottom plate 20 is attached and fixed to the upper surface of the stripper 23, so that the punch plate 12 directly presses the stripper 23 through the bottom plate 20 at the bottom dead center.

Problems to be Solved by the Invention However, in the conventional device, even if the residue 21 is present, the residue 21 is forcibly crushed and the shortest distance between the position sensor 1 and the stripper 23 does not change from the normal state, as shown in FIG.
There was a problem that it could not be detected.

Means for Solving the Problems In order to solve the above problems, in a press device having a punch residue detecting device of the present invention, the movement of the stripper is detected by a position sensor, and the extracted signal waveform is predetermined. A circuit for comparing with the reference waveform is provided, and the press operation is stopped when there is an abnormality in the comparison result.

Effect The present invention, by the above-described configuration, detects the position of the stripper at the bottom dead center in the related art, but can detect the abnormal operation of the stripper until reaching the bottom dead center, so that the stripper at the bottom dead center It is possible to detect even if there is no difference in the distance from the position sensor due to bottoming and smashing of shavings, and it is possible to detect shavings even in bending.

Examples Examples of the present invention will be described below. FIG. 1 is a block diagram of a processing circuit after extracting a signal from the position sensor 1 of the present invention and a diagram showing a processing waveform in the middle thereof. In FIG. 1, 2 is an amplifier for amplifying the signal taken out by the position sensor 1, 3 is a filter circuit for separating the amplified signal from noise, and 4 is a converter for converting the separated signal from analog to digital. It is an A / D conversion circuit. Reference numeral 5 is a first memory circuit that stores start data of a constant level. The start data of a constant level means that the distance between the stripper 23 and the position sensor 1 is the thickness of the workpiece 15 and the dust.
This is the signal level output from the position sensor 1 when the size is slightly larger than the size obtained by adding the thickness of 21, and can be artificially adjusted. The start data is continuously output to the start pulse generating circuit 6. The start pulse generation circuit 6 compares the signal from the A / D conversion circuit 4 with the data input from the first memory circuit 5, and generates a start pulse when the two have the same level. Of course, the signal input from the A / D conversion circuit 4 may generate the same level output at the rising and falling edges of the waveform, but a circuit for selecting and comparing the signal level at the rising edge is incorporated. Needless to say

The read comparison timing pulse generation circuit 7 generates a fixed amount of timing pulses at predetermined time intervals corresponding to the input from the start pulse generation circuit 6. The predetermined time interval is a minute time interval that can be compared sufficiently when A / D converting signal waveforms for comparison, and the time interval can be arbitrarily adjusted with respect to the waveform cycle. . Also, the amount of the timing pulse can be arbitrarily adjusted according to the cycle of the waveform. The second memory 8 corresponds to the timing pulse input from the read comparison timing pulse generation circuit 7 at a predetermined time interval, and stores the signal input from the A / D conversion circuit 4 at that time interval. Or, with a memory function that can calculate and average a signal of a predetermined number of shots and store it,
It has a read function of outputting the data stored in synchronization with the input from the read comparison timing pulse generation circuit 7 to the data comparison circuit 9, and both these functions are selectively switched by switching means (not shown). . Data comparison circuit 9
Then, the signal input from the A / D conversion circuit 4 and the data input from the second memory circuit 8 which are input in synchronization are compared, and the result is output to the power supply control circuit 10. Then, when there is a difference in the compared results, that is, when scrap scraping is detected, an output signal for turning off the drive power source is output to the press device 11.

Next, the operation of the structure will be described, but the position and the mounting method of the position sensor 1 of the press die device are the same as the conventional one.

First, several shot sample shots are performed to store the reference waveform. Then, the signal waveform taken out by the position sensor 1 is amplified by the amplifier circuit 2 and the noise is removed by the filter circuit 3. Next, the signal waveform is digitized by the A / D conversion circuit 4 and then input to the start pulse generation circuit 6. Therefore, when a signal having the same level as that of the first memory circuit 5 is input, a start pulse is generated and input to the read comparison timing pulse generation circuit 7. The read comparison timing pulse generation circuit 7 generates a timing pulse in response to the start pulse, and A / A is adjusted according to the time interval.
A signal is stored in the second memory circuit 8 from the D conversion circuit 4. This stored data can be calculated by first sampling an arbitrary number of shots and calculating the average value, and by storing the average value, or by storing the signals during mass production while calculating them at once. In the latter case, the accuracy of the stored data will increase, but when scraping is performed, that data will also be included in the reference waveform data.
Alternatively, it is necessary to provide a circuit that does not store the abnormal waveform at the time of scraping. Second as above
The reference waveform data shown in FIG. 2a stored in the memory circuit 8 of FIG. 2 is synchronized with the timing pulse from the read comparison timing pulse generation circuit 7, and at least the data stored up to the previous shot is used as the reference waveform in the data comparison circuit. Output to 9.

Next, the operation during mass production will be described. The signal that has passed through the A / D conversion circuit 4 through the same circuit as described above is divided into three signals.
One is the same path as when the reference waveform is stored after reaching the start pulse generating circuit 6. The other is the second
It enters into the memory circuit 8 of, but this is used only when the method of storing the signal at the time of mass production while calculating it at a time,
This circuit is closed in the method of sampling and storing the reference waveform in the first few shots. The remaining one is directly input to the data comparison circuit 9. In the data comparison circuit 9, the reference waveform data (FIG. 2a) from the second memory circuit 8 input in synchronization with the data comparison circuit 9 and the mass production shown in FIG. 2b or c from the A / D conversion circuit 4 are input. The waveform signals are compared, and the result is output to the power supply control circuit 10, but if there is a difference, the power supply control circuit 10 causes the pressing device 11 to
A signal to turn off the drive power is output. 2B shows a waveform at the time of normal operation, and c shows a waveform at the time of abnormal operation such as scraping.

By the above operation, when there is scrap scraping, an abnormality can be detected and the press device can be stopped. Whereas the conventional stripper 23 detects the position at the bottom dead center where it is most lowered, the stripper until reaching the bottom dead center in the present invention.
By detecting the moving state of 23, whether the moving process is normal or not, it is intended to detect an abnormal operation of the stripper 23, so that the stripper 23 is at the most lowered bottom dead center. According to the conventional configuration for detecting only the position, as shown in FIG. 5, when the dust is crushed, the difference from the normal position becomes very small, which makes it difficult to detect the position. According to the configuration of the present invention, even when the residue is crushed, it can be easily detected in the process because the movement state of the stripper 23 is different from the normal state.

That is, the stripper 23 comes into contact with the dust just before the dust is crushed, and the stripper 23 is lowered while crushing the dust sequentially from that state. Thus, the stripper 23 is tilted. Therefore, even if the scraps are crushed and the scraps are present or not and the state of the final stage is the same as shown in FIG. 5, the movement state of the stripper 23 in that process is different. is there.

As described above, according to the present invention, a circuit for detecting the movement of the stripper by the position sensor and comparing the extracted signal waveform with a predetermined reference waveform is provided. Since it is possible to detect the abnormal operation of the stripper up to the point, the stripper is bottomed at the bottom dead center, the scrap is crushed, and the abnormality can be detected even if there is no difference in the distance from the position sensor, and bending Even in the case of the above, it is possible to detect the scraps.

[Brief description of drawings]

FIG. 1 is a block diagram of a signal processing circuit in an embodiment of the pressing apparatus of the present invention, and a, b, and c of FIG. 2 are a reference waveform processed by the present invention, a normal waveform taken out during mass production, and an abnormality. FIG. 3 to FIG. 5 are diagrams showing waveforms at the time, and FIG. 3 to FIG. 5 are transverse cross-sectional views of the conventional press die device in a state of reaching the bottom dead center position. 1 ... Position sensor, 2 ... Amplification circuit, 3 ... Filter circuit, 4 ... A / D conversion circuit, 5 ... Memory circuit, 6 ...
Start pulse generation circuit, 7 ... Read comparison timing pulse generation circuit, 8 ... Memory circuit, 9 ... Data comparison circuit, 10 ... Power control circuit, 12 ... Punch plate, 13 ... Die plate, 15 ... Work, 20 …… bottom plate, 23 …… stripper.

Claims (1)

[Claims] 1. A position sensor for sequentially generating a detection signal according to a height position of the stripper when the stripper moves, a first memory means capable of setting a reference value adjustable, a detection output of the position sensor and the A start pulse generator that sequentially compares the reference value and generates a start pulse when the two match, and a timing pulse that generates a timing pulse at a predetermined interval in synchronization with the generation of the start pulse. Generating means, second memory means capable of storing a value obtained by sequentially sampling the detection output by the timing pulse as a reference waveform, and sequentially reading the stored reference waveform by the timing pulse; The output and the previous detection output read from the second memory means are sequentially compared and both are output. When having the different press apparatus characterized by stopping the operation of the stripper.