JPH02255300A - Press machine - Google Patents

Abstract

PURPOSE:To prevent the generation of blanking defective articles and the failure of the machine by detecting the abnormality of blanking sounds and emitting an alarm simultaneously therewith at the time of blanking parts with the press machine. CONSTITUTION:A work W, such as steel sheet, is blanked by freely rotatably and pivotally supporting an upper turret 1 and a lower turret 2, moving a pair of a punch 3 and die 4 mounted to both the turrets to a punching position by the revolution of a motor M and lowering a ram 5 by a hydraulic cylinder device 7 to push down the head part of the punch 3. A microphone 9 is installed near the cylinder 7 of this device to detect the blanking sounds of the work W by the punch 3. Idle blanking, blanking of two sheets, and the difference of dies are detected from these sounds and the abnormal state thereof is decided, by which the alarm is generated and the generation of the defective articles of the blanked articles and the damage of the press machine thereafter are prevented.

Description

[Detailed description of the invention] [Purpose of the invention] (Industrial application field) The present invention relates to a press machine.

(Prior art) In conventional press machines, such as hydraulic presses, the stroke can be controlled arbitrarily, and the ram can be controlled at high speed until it reaches the top of the workpiece, then at low speed until the punching is completed, and then returned at high speed, thereby controlling the pattern. do.

These operation patterns are appropriately set based on empirical rules and conditions such as the material and plate thickness of the workpiece and the punched shape.

(Problem to be Solved by the Invention) However, as mentioned above, in conventional press machines, the operation pattern is appropriately designed based on empirical rules, and the operation is performed according to the designed operation pattern. Therefore, it was only possible to estimate the so-called breaking point, and it was not possible to perform appropriate control according to the actual breaking point.

In addition, conventional press machines were configured to operate according to a set operation pattern, so abnormal conditions could not be recognized.
If an abnormality occurs such as blank punching, double punching, or incorrect molds, the machine may continue to operate, resulting in continued production of defective products or damage to the machine.

Therefore, the present invention provides a press machine that can detect a breaking point, perform appropriate control based on the detected breaking point, detect an abnormality in the punching table, and immediately output an alarm when an abnormal condition occurs. The purpose is to provide

[Structure of the Invention] (Means for Solving the Problems) A press machine of the present invention that solves the above problems is equipped with a microphone that detects the punching table, and compares the level of the detected punching sound with a reference level. A level comparing means for deforming the subsequent press operation when the level of the punching table exceeds a reference level is provided, and an abnormality detecting means is provided for comparing the detected waveform of the punching table with the reference waveform and detecting an abnormality. It is characterized by

(Function) The press machine of the present invention is provided with a microphone that detects the punching table, detects a breaking point based on the sound pressure level detected by the microphone, and increases the subsequent punching speed based on this breaking point. Optimize subsequent control, such as by

In addition, blank punching is performed by comparing the waveform of the punching table detected by the microphone with the reference waveform.

Detects abnormalities such as two sheets being struck or a difference in mold, and outputs an alarm.

(Example> Examples of the present invention will be explained below.

FIG. 1 shows a hydraulic turret punch press as a specific example of a press machine.

The illustrated turret punch press has an upper turret 1 and a lower turret 2 rotatably supported, and a pair of punches 3 and dies 4 attached to arbitrary stations of both turrets 1 and 2.
is moved to the punching position by the rotation of the motor M, and the head of the punch 3 is pushed down by the ram (striker) 5 located above, thereby punching the workpiece W interposed between the turrets 1 and 2. It is something.

l) One end of the n workpiece W is held by a clamp device 6 and can be moved to any position on the plane coordinates.

Also, a cylinder device 7 is provided to drive the ram 5 up and down.
is provided, and the device 7 is a servo valve (electromagnetic proportional valve) SQL
It is controlled by a hydraulic unit 8 equipped with.

A microphone 9 is provided near the cylinder device 7 to detect the punching table (sound).

FIG. 2 is an explanatory diagram showing the circuit configuration of the hydraulic unit 8. As shown in FIG.

As shown in the diagram, the hydraulic circuit is a general one, with oil tank 1
0 oil is assembled by a hydraulic pump P and supplied to an electromagnetic proportional valve 501- through a check valve CV and a filter F, and the cylinder 7 is controlled at high speed by high-speed operation of the electromagnetic proportional valve.

As shown in FIG. 3, the punching sound processing device disposed between the microphone 9 and the hydraulic unit 8 includes a punching sound input section 11, a ram speed switching control section 12, and a reference waveform storage section. 13, an alarm discriminator 14, an alarm display section 15, and a stop control section 16.

The punching sound input section 11 receives an analog signal from the punching table from the microphone 9, amplifies it as appropriate, and outputs it to the ram speed switching determination section 12.

Further, this waveform is converted into a digital signal and output to the alarm discrimination section 14.

Therefore, the analog signal ΔW output from the punching sound input section 11 to the ram speed switching determination section 12 is instantaneously propagated, but the digital signal D output to the alarm determination section 14
w is occasionally delayed by the signal conversion time.

The ram speed switching determination unit 12 compares the input signal level L of the punching table with a reference level Lo, and determines that L≧. The breaking point is detected under the following conditions, and the speed conversion signal S
This outputs the following.

That is, as shown in FIG.
When operated, the punching sound pattern 18 changes as shown in the figure, and the punching sound AW suddenly changes at time Tc.

Therefore, by comparing this variation with the reference level LO, the breaking point pc can be detected.

Therefore, the ram speed switching determination unit 12 outputs the speed switching command S at this time Tc, as shown in FIG.
After c, convert the punching speed from V2 to V3 and quickly punch I.
This is to end the auxiliary machining and improve machining efficiency.

On the other hand, the alarm discriminator 14 shown in FIG. 3 inputs waveform signals DW+, DW2, and D-3 as shown in FIGS. is compared with a reference waveform [)WO as shown in FIG. 9 to detect an abnormality in the press.

Incidentally, since the amplitude shown in FIG. 6 is extremely small, it can be determined that this is blank firing. In the case shown in FIG. 7, one attenuation occurs in two stages compared to the standard case 20, so it can be determined that the case is a two-piece structure. Since the amplitude A3 shown in FIG. 8 is too large compared to the reference amplitude Ao, it is determined that, for example, a mold with a different clearance is used.

In this way, the alarm discrimination unit 14 detects these abnormalities,
An alarm display command is output to the alarm display section 15, and a stop command is output to the stop control section 16.

As a result, the alarm display section 15 displays blank shots, double shots,
Displays abnormal conditions such as mold difference, and also stops F system feed 0 part 16
puts an emergency stop on the machine.

Here, the waveform is processed by a digital signal, but the time delay associated with this is on the order of several ms to tens of ms, which is sufficiently short compared to the time until the next press operation.
This time delay does not pose any problem.

As described above, in the press machine of this example, by automatically detecting the break point PC, the subsequent punching speed up to the punching end point can be increased to increase processing efficiency, and abnormal conditions can be automatically detected, Can output alarm and emergency stop.

In the above embodiment, the subsequent punching speed was increased based on the detection of the breaking point pc, but in the case of a workpiece W whose plate thickness is relatively small, the end of punching is determined by this, and (if necessary) Various appropriate controls can be carried out, such as switching the ram 5 to a rising position (for example, after a short period of time).

In addition, in the above embodiment, an example is shown in which abnormalities such as blank punching, double punching, and mold difference are detected and an alarm is output. Various abnormalities can be detected.

Further, in the above embodiment, the sound waves (sound 'n>) are shown, but it goes without saying that the sound waves input to the microphone 9 may include signals such as vibration sounds and resonant sounds. As an application, the obtained waveforms can be stored and used for diagnostic work on machines and molds.

The present invention is not limited to the above embodiments, but can be implemented in any appropriate manner by making appropriate design changes.

"Effects of the Invention" As described above, since the present invention is a press machine as described in the claims, it is possible to detect a breaking point and perform appropriate control based on the detected breaking point. It can also detect abnormalities during punching and output a striking alarm.

[Brief explanation of drawings]

Fig. 1 is a side view of a turret punch press as an example of a press machine embodying the present invention, Fig. 2 is an explanatory diagram of its hydraulic circuit, Fig. 3 is a block diagram of a punching sound processing device, and Fig. 4 is a side view of a turret punch press as an example of a press machine implementing the present invention. An explanatory diagram of the punching sound shown in a time chart, FIG. 5 is an explanatory diagram showing an example of adaptive control based on the breaking point, and FIGS. 6 and 7
The figure and FIG. 8 are explanatory diagrams of punching sound waveforms for blank punching, double punching, and different molds, and FIG. 9 is an explanatory diagram of FAFIP=waveform. 5... Ram 9... Microphone 11... Punching sound input section 12... Ram speed switching discrimination section 14... Alarm discrimination section, 611... Analog signal of punching table [)WO. ...Reference waveform of the punching table DW+, DW2, DW3...Waveform p of the actual punching table
c... Breaking point Agent Patent attorney Hidekazu Miyoshi Figure 2 Figure 1 Figure 3

Claims (4)

[Claims] (1) A microphone is provided to detect the punching sound, and a level comparison means is provided which compares the level of the detected punching sound with a reference level and changes the subsequent press operation when the level of the punching sound exceeds the reference level. A press machine, characterized in that it is equipped with abnormality detection means for detecting press abnormalities by comparing the waveform of the detected punching sound with a reference waveform. (2) The press machine according to claim 1, wherein in the subsequent modification of the press operation by the level comparison means, the punching speed subsequent to the breaking point is increased. (3) The press machine according to claim 1, wherein the abnormality detection means detects blank punching, double punching, and mold difference. (4) The press machine according to claim 1, wherein the level comparison is processed using an analog signal, and the waveform comparison is processed using a digital signal.