JPH0686038B2 - Press machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to a press machine.

(Prior Art) In a conventional hydraulic press machine, for example, its stroke can be arbitrarily controlled, and the ram is controlled to a high speed up to the work upper surface, a low speed until the punching is completed, and then a high-speed turning back. To do.

These operation patterns are appropriately set on the basis of empirical rules according to conditions such as the work material, plate thickness, and punching shape.

(Problems to be Solved by the Invention) However, in the conventional press machine as described above, the operation pattern is appropriately designed based on an empirical rule, and the operation is performed according to the designed operation pattern. It was only possible to infer the point, and it was not possible to perform appropriate control according to the actual break point.

Moreover, since the conventional press machine is configured to operate according to the set operation pattern, it cannot recognize the abnormal state,
If an error such as blank shot, double shot, die difference, etc. occurs,
There were problems such as continuous operation, continuous production of defective products, and damage to the machine.

Therefore, the present invention can detect a break point and perform appropriate control based on the detected break point, detect an abnormality in punching sound, and output an alarm immediately when an abnormal state occurs. The purpose is to provide.

[Structure of the Invention] (Means for Solving the Problems) In view of the conventional problems as described above, the present invention provides a ram that is moved up and down by the operation of a cylinder device controlled by a hydraulic unit, and is pushed down by the ram. And a microphone for detecting the punching sound of the work by the punch and the die, and a press machine comprising a die for punching the work in cooperation with the punch, and the input from the microphone. The signal level of the punching sound is compared with the reference level, and the speed change signal for detecting the breaking point of the work and increasing the operating speed of the cylinder device under the condition of signal level> reference level is used as the hydraulic unit. The ram speed switching discriminating section for outputting to the ram speed switching discriminating section, the punching sound inputted from the microphone and the reference waveform stored in the reference waveform storage section. And alarm determination unit which compare to determine an abnormality is made and a alarm display unit for displaying an abnormal state is judged by the alarm determination unit.

(Operation) In the press machine of the present invention, a microphone for detecting punching sound is provided, the break point is detected by the sound pressure level detected by the microphone, and the subsequent punching speed is increased based on this break point. To optimize the subsequent control.

Further, by comparing the waveform of the punching sound detected by the microphone with the reference waveform, abnormalities such as blank shot, double shot, die difference, etc. are detected and an alarm is output.

(Example) Hereinafter, the Example of this invention is described.

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

In the illustrated turret punch press, an upper turret 1 and a lower turret 2 are rotatably supported, and a pair of punches 3 and dies 4 attached to arbitrary stations of both turrets 1 and 2 are moved to a punch position by rotating a motor M. The work W is moved, and the head of the punch 3 is pushed down by a ram (striker) 5 located above it, so that the work W interposed between the turrets 1 and 2 is punched.

One end of the work W is gripped by the clamp device 6 and can be moved to any position on the plane coordinates.

In addition, a cylinder device 7 is provided to drive the ram 5 up and down.
Is provided and the device 7 is controlled by a hydraulic unit 8 having a servo valve (electromagnetic proportional valve) SOL.

A microphone 9 for detecting punching sound (sound) is provided near the cylinder device 7.

FIG. 2 is an explanatory diagram showing a circuit configuration of the hydraulic unit 8.

As shown in the figure, the hydraulic circuit is general and the oil tank 10
Oil is assembled by the hydraulic pump P and supplied to the solenoid proportional valve SOL via the check valve CV and the filter F, and the cylinder 7 is controlled at high speed by the high speed operation of the solenoid proportional valve.

As shown in FIG. 3, the punching sound processing device arranged between the microphone 9 and the hydraulic unit 8 includes a punching sound input unit 11, a ram speed switching control unit 12, and a reference waveform storage unit.
Alarm discrimination unit 14 connected to 13 and alarm display unit 15
And a stop control unit 16.

The punching sound input unit 11 receives the analog signal of the punching sound from the microphone 9, amplifies it appropriately, and outputs it to the ram speed switching judging unit 12. In addition, this waveform is converted into a digital signal and output to the alarm determination unit 14.

Therefore, the punching sound input unit 11 to the ram speed switching determination unit 12
The analog signal Aw output to is propagated instantaneously,
The digital signal Dw output to the alarm determination unit 14 is rarely delayed by the signal conversion time.

The ram speed switching discriminating unit 12 compares the input punching sound signal level L with a reference level Lo, detects a breaking point under the condition of L ≧ Lo, and outputs a speed shift signal S to the hydraulic unit 8. It is a thing.

That is, as shown in FIG. 4, when the ram 5 is operated by the pattern 17, the punching sound pattern 18 changes as shown in the drawing, and the punching sound Aw suddenly changes at the time Tc. Therefore, the breaking point Pc can be detected by comparing this variation with the reference level Lo.

Therefore, as shown in FIG. 5, the ram speed switching discriminating unit 12 outputs the speed switching command S at this time Tc, and after the break point Pc, converts the punching speed from V ₂ to V ₃ and promptly. The punching process is completed and the processing efficiency is improved.

On the other hand, the alarm discrimination unit 14 shown in FIG. ₃ inputs the waveform signals Dw ₁ , Dw ₂ and Dw ₃ as shown in FIGS. 6 to 8 obtained by converting the punching sound into a digital signal, This is compared with a reference waveform Dwo as shown in FIG. 9 to detect a press abnormality.

Incidentally, since the amplitude shown in FIG. 6 is extremely small, it is discriminated that it is a blank hit. In the case shown in FIG. 7, since the attenuation 19 is generated in two stages as compared with the reference case 20, it is judged that two shots have been made. Since the amplitude A ₃ shown in FIG. 8 is too large as compared with the reference amplitude Ao, it is discriminated that, for example, molds having different clearances are used.

Thus, the alarm determination unit 14 detects these abnormalities, outputs an alarm display command to the alarm display unit 15, and
A stop command is output to the stop control unit 16.

As a result, the alarm display unit 15 displays an abnormal state such as blank driving, double-pressing, and die difference, and the stop control unit 16 makes an emergency stop on the machine.

Here, the waveform is processed by a digital signal, but the time delay associated with this is several ms to tens of ms, so it is a sufficiently short time compared to the time until the next press operation. It doesn't matter at all.

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

In the above-described embodiment, the punching speed thereafter is set to be high based on the detection of the break point Pc. However, in the case of the work W having a relatively small plate thickness, the punching end is determined by this ( For example, various appropriate controls can be performed such that the ram 5 is switched to the rising position after a minute time.

Further, in the above-described embodiment, an example is shown in which an error such as blanking, two-sheet punching, and die difference is detected and an alarm is output. However, it is possible to detect a workpiece difference or detect the life of the die due to secular change. It is possible to detect various abnormalities, such as

Further, although the sound wave (sound) is shown in the above-mentioned embodiment, the sound wave input to the microphone 9 may of course include a signal such as a vibration sound or a ringing sound. In addition, as another application, the obtained waveform can be stored and used for machine or die diagnosis work.

The present invention is not limited to the above-described embodiments, but can be carried out in appropriate modes by making appropriate design changes.

[Effects of the Invention] As will be understood from the above description of the embodiments, the present invention is, in short, the ram 5 that is vertically moved by the operation of the cylinder device 7 controlled by the hydraulic unit 8 and the ram 5 that pushes down the ram 5. A press machine comprising a punch 3 to be punched and a die 4 for punching a work W in cooperation with the punch 3, and a microphone for detecting punching sound of the work W by the punch 3 and the die 4. 9 and the signal level L of the punching sound input from the microphone 9 and the reference level Lo are compared, and the breaking point of the work W is detected under the condition that the signal level L> the reference level Lo and the cylinder device Ram speed switching discriminating section 12 for outputting a speed shift signal S for increasing the operating speed of 7 to the hydraulic unit 8, punching sound inputted from the microphone 9, and a reference An alarm discriminating unit 14 for discriminating an abnormality by comparing the reference waveform Dwo stored in the waveform storage unit 13 and an alarm display unit 15 for displaying the abnormal state discriminated by the alarm discriminating unit 14 are provided. It is a thing.

As is apparent from the above configuration, in the present invention, when the microphone 9 detects the punching sound and the ram speed switching determining unit 12 detects the break of the work W by the detection signal, the ram speed switching determining unit 12 Since the speed conversion signal S is output from the hydraulic unit 8 to increase the operation of the cylinder device 7, the working efficiency is further improved.

Further, in the present invention, the punching sound waveform detected by the microphone 9 and the reference waveform are compared in the alarm discrimination unit 14, the alarm is discriminated, and the discriminated abnormality is displayed on the alarm display unit 15. Therefore, by observing the display of the alarm display section 15, it is possible to know that the cause of the alarm is an abnormal state such as blank shot, double shot, die difference, etc. The processing can be performed quickly.

[Brief description 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 view of a hydraulic circuit thereof, FIG. 3 is a block diagram of a punching sound processing device, and FIG. Explanatory diagram of punching sound shown in time chart, FIG. 5 is an explanatory diagram showing an example of adaptive control based on a break point, FIG. 6 and FIG.
FIG. 8 and FIG. 8 are explanatory diagrams of blanking and double-sheet punching and punching sound waveforms for different dies, and FIG. 9 is an explanatory diagram of reference waveforms. 5 …… Ram 9 …… Microphone 11 …… Punching sound input section 12 …… Ram speed switching judgment section 14 …… Alarm judgment section Aw …… Punching sound analog signal Dwo …… Punching sound reference waveform Dw ₁ , Dw ₂ , Dw ₃ …… Actual punching sound waveform Pc …… Break point

Claims (1)

[Claims] 1. A ram (5) moved up and down by the operation of a cylinder device (7) controlled by a hydraulic unit (8).
And a punch (3) pushed down by the ram (5)
And a press machine comprising a die (4) for punching a work (W) in cooperation with the punch (3),
A microphone (9) for detecting the punching sound of the work (W) by the punch (3) and the die (4), and a signal level (L) of the punching sound input from the microphone (9) and a reference. Compare with the level (Lo), and under the condition that the signal level (L)> reference level (Lo), the work (W)
Of the ram speed switching discriminator (12) that outputs a speed conversion signal (S) for increasing the operating speed of the cylinder device (7) to the hydraulic unit (8) by detecting the breaking point of the An alarm discriminating unit (14) for discriminating an abnormality by comparing the punching sound inputted from 9) with the reference waveform (Dwo) stored in the reference waveform storage unit (13), and the alarm discriminating unit (14). ), And an alarm display section (15) for displaying an abnormal state determined by the press machine.