JPS6293687A - Apparatus for measuring press stop time - Google Patents

Abstract

PURPOSE:To remove the adverse effect of counteraction and vibration at the stop time of a slide, by cutting off the input of a clock pulse even if there is no signal input from an encoder for a definite time. CONSTITUTION:When a stop order is applied to a press machine, the counting of a clock pulse is started by counters 11a-11c. When a clutch brake is applied by the stop order, the moving speed of a slide gradually lowers and the cycle of the pulse signal generated from an encoder 3 gradually becomes long with the lowering in said moving speed. When it is detected that the moving speed of the slide is in a state immediately before stoppage in relation to the pulse signal of the encoder 3, the counting of the clock pulse is stopped. The stop time of the press machine is displayed on display devices 14a-14c on the basis of the count value and the cycle of the clock pulse.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a press stop time measuring device that measures the time from when a stop command is given to a press machine until the slide of the press machine stops. '' In the conventional device of this type, the command signal C/B (when C/B is at H level, current flows through the lunoid) which drives the solenoid current of the clutch brake in the press machine, as shown in Fig. 3(a) K, is used. From the point at which the clock pulse CP for measurement (FIG. 3(C)) reaches the L level, counting is started, and each signal output from the encoder generates a synchronized pulse signal corresponding to the moving speed of the slide of the Presumi I shield. By latching the counter at each rising edge of the pulse signal IN, the time 11, 1, ..., ...70 was measured (Fig. 3 (b)). Therefore, the final The time t until the last pulse signal is output from the encoder is displayed as the press stop time (Utility Model Publication No. 54-43420).

[Problems to be Solved by the Invention] However, the pulse signal (Fig. 3 (b)) output from the encoder on the broken line A is generated by the reaction and vibration when the slide stops. The measured value of the stop time varied greatly depending on the presence or absence of the uppulse signal, which caused problems with the reliability of the measured value.

[Means for solving problems]

In order to solve the above-mentioned problems, the present invention aims to terminate the input of clock pulses if there is no signal input from the encoder for a certain period of time, thereby eliminating the adverse effects of recoil and vibration when the slide stops. , an oscillator that oscillates clock pulses, and an encoder that outputs a pulse signal with a period corresponding to the moving speed of the slide of the press machine;
a detection means for detecting that a pulse signal has not been outputted from the encoder for a certain period of time; and a clock oscillated by the oscillator until detection by the detection means is performed after a stop command is given to the press machine. It consists of a counter that counts pulses and a display that displays the stop time of the press machine based on the count value of the color/return.

[Effect]

That is, when a stop command is given to the press machine, counting of clock pulses is started. When the clutch brake is applied in response to the above-mentioned stop command, the moving speed of the slide gradually decreases, and the period of the pulse signal generated from the encoder gradually becomes longer. Then, when it is detected in relation to the clock pulse signal of the encoder that the moving speed of the slide is in a state immediately before stopping, counting of the clock pulse is stopped. The stop time of the press machine is displayed on the display based on this count value and the period of the clock pulse. [Embodiment] The present invention will be described in detail below with reference to the accompanying drawings.

In Fig. 1, a command signal C/B (0
/B is at E level and the solenoid current flows) is inverted by inverter 1 and applied to AND circuit 2. This command signal 0/B is a signal that is at the E level when the clutch is on, and is at the L level when the clutch is off, as shown in the WJZ diagram (a).

A signal EN from an encoder 3 (FIG. 2(b)) is applied to the other input of the AND circuit 2.
is attached to the main shaft or rotary camshaft of a press machine, which rotates according to the moving speed of the slide, and generates a pulse signal every time these shafts rotate by a predetermined angle.

This signal substantially corresponds to the moving speed of the slide, and as shown in FIG. 2(b), when the signal 0/B is at level ■, it becomes a pulse with a predetermined period;
When B goes to L level, the period becomes gradually longer and stops occurring when the slide stops.

The AND circuit 2 takes the AND condition of the two human input signals and outputs it to the retrigger type monostable multivibrator 4. This monostable multi/<ibrator 4 is an AND circuit 2
It is triggered when the input signal from the H level falls from the H level to the L level, and the desk remains stable for a certain period of time T, and then the H level
It outputs a signal at level fk8, and when it reaches a stable state, it outputs a signal at L level. Note that this monostable multi-bi break 4 is of a re-trigger type that is triggered again when the input signal falls during the above-mentioned fixed time T. Moreover, the above-mentioned fixed time T is determined by the capacitor C and the resistor R. For example, when there is a slide with a rated speed of 300 rpm and sensing is performed using an encoder that divides one revolution into 360, and the press stop time measurement is to end when the speed of the slide becomes 1/20th, the fixed time T is Based on the pulse period at that time, it is sufficient to set T=1/90# 11.1 msec. The output signal QN of this monostable multivibrator 4 becomes K as shown in FIG. 2(e).

The output signal QN of the monostable multivibrator 4 is applied to the D input of the D flip-flop 5, inverted by the 1-inverter 6, and applied to the D input of the D flip-flop 7. A command value gO/B is applied to the reset terminals R of the D flip-flops 5 and 7, respectively, and each is reset when the signal c 7 s IJ=g level. An AND circuit 8 which receives these D flip-flops 7' 5.7, the output Q of the terminal Q of the D flip-flop 5, and the output QB of the terminal Q of the D flip-flop 7, is connected to a plurality of H level states of the signal QN. If there are (there are two in the example of FIG. 2(e)), 2
The output Q at the terminal Q of the D flip-flop and the output QB at the terminal Q of the A and D flip-flops are respectively shown in FIG. 2(d).
And these AND conditions as shown in (e)?
The output QC of the AND circuit 8 is as shown in FIG. 2(f).

The output QC of the AND circuit 8 is applied to the AND circuit 9 and the input PO of the latch circuits 12a, 12b, 12c.
added to. The other input of the AND circuit 9 includes the oscillator 1
Clock pulse C1 for measurement from 0 (Fig. 2 [Co., Ltd.]))
are being added all the time. Therefore, the AND circuit 9 is
When the signal QC applied to one input becomes H level and becomes operable, a clock pulse c2 (FIG. 2(h)) is introduced to the clock input of the counter lla for only the operable period.

The counter 111 (!) has the signal C/B applied to the reset terminal R, and is reset to 0 when the signal C/B is at H level, and becomes capable of counting when it goes to L level. ”, 11b.

llC is a binary decimal counter, and when the count value of the counter 11a reaches 10 in decimal, it becomes 0, a carry signal is added to the counter 11b, and the counter llC
b counts this carry signal, and when the count value reaches 10 in decimal notation, it becomes 0, and the carry signal is sent to counter 11.
It is designed to be added to 0. That is, the counter
a indicates the value of the ones place of the count value corresponding to a decimal number, counter 11b indicates the value of the tens place of the count value, and counter 1ic indicates the value of the ioo place of the count value.

Each bit output of the counter 1lallbllIC is connected to a latch circuit 12' e 12 b+ 12 C
added to. The latch circuit 12al12b#12G is
When the signal QC applied to each manual PO is at H level, the input signal is directly input to the decoder/driver 13a.

13b and 13G, and when the signal QC goes to L level, the input signal at that time is protected and the held signal? Output to decoder O driver 13a#13b#13C.

The decoder drivers 13a, 13b, and 130 convert the input binary data into a decimal number,
Appropriate drive signals are output to display on the 7-segment type display 14'p14be14C, and the display 14a, 14
k) and 140, corresponding numbers are digitally displayed. Therefore, the clock pulse a of the oscillator 10
If the period of 1 is 21771 seconds, the display 14a114b
1140 is just that! The press stop time in the range of 0 to 999 #1 seconds will be displayed. In addition, the display on the displays 14a, 14b, and 14a will include the metastable period of the monostable multivibrator 4 (in the above example, T- It has an off-seraton of 11.1 msec], but there is no variation due to the presence or absence of recoil or vibration when the slide stops (This measured press stop time is extremely effective in discovering abnormalities in the press machine. .

Of course, since the offset time is already known, the offset time may be subtracted from the measured press stop time and displayed.

In addition, in this example, if the encoder signal does not fall within a certain period of time after the encoder signal falls, the measurement of the subsequent press stop time is aborted using the monostable multivibrator. For example, if the time from the fall or rise of a signal from an encoder is measured, and the encoder signal does not fall or rise during a certain period of time measurement,
Even if the measurement of the press stop time is discontinued, the cost will be increased if the press stop time measurement is discontinued when the slide of the press machine is decelerated to a predetermined speed immediately before the stop. But that's fine.

[Effects of the Invention] As explained above, according to the present invention, the influence of reaction, etc. when the press is stopped can be eliminated, and the press stop time can be accurately measured without large variations.

[Brief explanation of drawings]

Figure 2 is a block diagram showing one embodiment of the present invention, Figure 2 (
A) to (h) are timing charts showing the signals of each part in FIG. 1, and FIGS. 3(a) to (0) are timing charts used to explain the problems of the conventional technology, respectively. 3. Enco-II", 4- Monostable multivibrator, 5.7 ・D flip-flop, 10- Oscillator,
11a'#11bt110・-Kakunta, 12a$12
k) 1120...Latch circuit, 13al13kll1
3e-decoder driver, 14a #141) t14c
- Indicator. +-j',',,--:1

Claims (2)

[Claims] (1) An oscillator that oscillates clock pulses, an encoder that outputs a pulse signal with a period corresponding to the moving speed of the slide of the press machine, and a detection that detects that the pulse signal is not output for a certain period of time from the encoder. means, a counter for counting clock pulses oscillated from the oscillator until detection by the detection means after a stop command is given to the press machine, and stopping the press machine based on the counted value of the counter; A press stop time measuring device equipped with a time display. (2) The detection means is a re-trigger type that is triggered by the input of a pulse signal output from the encoder and outputs a signal with a pulse width corresponding to the certain time as a signal that enables the counter to operate. A press stop time measuring device according to claim (1), comprising a monostable multivibrator.