JPS6152498A - Safety device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (1) Technical Field of the Invention The present invention relates to machine tools such as press machines, and particularly to a safety device that provides a large number of light beams in a certain area for safety purposes.

(2) Prior art In order to prevent danger, press equipment generally uses light emitting elements and light receiving elements to provide a large number of light beams between the press driving area and the worker's work area, and there is an object that blocks the light beams during press operation. A safety device is provided to stop the press operation.

Normally, this device is controlled by electronic circuits, but there are times when conveyors, etc., block certain light beams at regular intervals during the press operation process, and in such cases, safety devices are installed to prevent the press operation from stopping. A bypass circuit is provided to prevent the detection operation.

(3) Problems with the Prior Art Even when an object that blocks a light beam blocks only a specific light beam, in the past, not only the specific light beam was bypassed, but all the light beams were bypassed.

Therefore, safety cannot be maintained due to one worker's carelessness, and in order to prevent this, the circuit operation of the bypass circuit itself must be stopped using another device, which is very inefficient. Ta.

(4) Purpose of the Invention In view of the above-mentioned conventional drawbacks, the present invention makes it possible to bypass each luminous flux individually, and for this purpose, the key switch provided in the bypass circuit must be turned off once. The object of the present invention is to provide a safety device that makes it possible to operate a press device more safely by turning it on from the start.

(5) Structure of the Invention The above object is achieved by 1. According to the present invention, there is provided a main stage for creating a plurality of light beams, a detecting means for detecting an abnormality by transmitting or blocking the light beams, and a means for detecting an abnormality by transmitting or blocking the light beams. a bypass means for determining the character to be correct even when a character is written; a memory means for storing a bypass position specified by the luminous flux; a switching means for storing the bypass position in the memory means; and a switching means for periodically controlling the operation of the bypass means. This is achieved by providing a safety device characterized in that it has synchronization blocking means.

(6) Embodiments of the Invention Below, one embodiment of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 2 is a block diagram showing a schematic configuration of the press safety device.

In the figure, light projecting section 1. The light-receiving section 2 is attached to face the main body of the press machine, and the light emitting elements arranged in a row in the light-emitting section 1 emit light to the light-receiving elements similarly arranged in a row in the light-receiving section 2. .

The light rays between each light emitting element and the light receiving element constitute a large number of light beams. A control current is input from the control circuit 3 to each light emitting element of the light projecting section 1, and a signal indicating whether each light receiving element has received light is output from the light receiving section 2 to the control circuit 3.

Further, a certain signal is input from the control circuit 3 to the bypass circuit 4, and according to this signal, the bypass circuit 4 specifies the luminous flux to be canceled (bypassed) among the above-mentioned luminous fluxes, and sends the signal to the control circuit 3. Output.

The control circuit 3 constantly monitors the signal input from the light receiving section 2 according to the signal instructed by the bypass circuit 4, and when the control circuit 3 determines that it is dangerous,
A stop signal is output from the control circuit 3 to the press emergency stop device 5.

FIG. 1 shows a detailed block diagram of the bypass circuit 4 used in the press safety device as described above.

In the figure, signals indicating each of the above-mentioned luminous fluxes are sequentially input from the control circuit 3 to the input control unit 7, and the input control unit 7 displays whether each light receiving element has received light according to the input signal. A signal is output to the light reception display section 8, and a signal indicating each luminous flux is output to the data selector 12.

The memory 9 is stored by the bypass position setting section 10.

Data on the light flux to be bypassed is stored in advance.

The memory 9 outputs a signal indicating the light flux to be bypassed to the bypass position display section 11 based on the bypass position signal input from the bypass position setting section 10, stores the bypass position signal, and outputs the bypass position signal to the data selector 12. .

The data selector 12 multiplexes the bypass position signal based on the signal input from the input control section 7 described above and outputs it to the comparator 13 . The number of light beams to be bypassed is set in advance in the comparator 13 by the bypass number setting section 14, and the output of the comparator 13 is set by the key control section 15.
Enter.

A synchronization signal is input to the key control section 15 from a synchronization signal generation section 17 via a key switch section 16 .

The key control section 15 outputs a bypass signal indicating that bypass is in progress to the bypass display section 18 according to the signals input from the comparator 13 and the key switch section 16, and also outputs the same signal to the memory 9 and the output control section 19g. do. The output control section 19 uses the signal input from the data selector 12 and the signal input from the key control section 15.

A signal instructing the bypass position and a signal prohibiting bypass are output to the control circuit 3.

Here, the key control section 15. A specific circuit configuration of the key switch unit 16° synchronization signal generating unit 17 is shown in FIG. The synchronization signal generating section 17 provides a manual switch or the like in the rotating section of the press device and outputs a synchronizing signal to the key switch section 16 in synchronization with the rotation period of the one rotation section. The key switch section 16 is
It is a switch that can be operated from the outside and is operated by a person different from the person who normally sets the bypass position. Key switch part 1G
In this case, when the key switch 16a is on, a synchronization signal is output, and when it is off, an off signal for the key switch section 16 is output. This output signal is input to one input terminal of an AND gate 20 of the output control section 15 via an inverter 22, and is also input to a reset terminal of a reset set flip-flop circuit (hereinafter referred to as a flip-flop) 21.

Comparator 1 is connected to the other input terminal of AND gate 20.
The output of AND gate 20 is input to the set terminal of flip-flop 21. The output of the flip-flop 21 is output as the output of the key control unit 15.
Bypass display section 18° memory 19. It is output to the output control section 19.

As described above, the bypass circuit 4, key control unit 15, etc.
For example, when one of the optical axes is bypassed and the control circuit 3 is used, the bypass position setting section 1o sends a bypass position signal to the flip-flop in the memory 9 corresponding to that beam. Input and memorize. At this time, it is necessary to input a bypass signal from the key control section 15 to the memory 9, and in particular, the memory 9 can store the above-mentioned bypass position signal only when the bypass signal rises from a low level to a high level. Therefore, the bypass position signal cannot be stored in the memory 9 unless the output of the flip-flop 21 is switched from low level to high level. In order to invert the output of the flip-flop 21 as described above, the comparator 13
If the output of the AND gate 20 is always held at a high level, both the key switch section 16 and the synchronization signal ordering section 17 are turned on, and one input terminal of the AND gate 20, which is at a high level, is connected to the input terminal of the AND gate 20 through the normal resistor 23. It is necessary to once set the reset terminal of the flip-flop 21 to a high level (ground level).

In other words, the key switch 16a must be turned off once, and the bypass position is stored in the memory 9 when the key switch 16a is turned on again. Therefore, the number of light beams to be bypassed to the memory 9 is changed from one to two to three to three.
... or when you want to remember to increase the luminous flux, or when specifying another luminous flux.

The new bypass position signal will not be stored in the memory 9 unless the key switch 16 is turned off and then turned on again.

When the bypass position is not stored in memory 9.

The output control unit 19 outputs a signal for prohibiting bypass to the control circuit 3, and the control circuit 3 operates one optical axis without bypassing all the optical axes.

Therefore, if such a key switch 16 can be operated only by the person in charge of the work, erroneous light beams will not be bypassed.

Furthermore, by periodically turning on and off the switch 17a in the synchronization signal generating section 17, bypass can be prohibited during times when bypass is not required during the press process, and safety can be improved by reducing the bypass time. can be improved.

Furthermore, the bypass position setting section 10 specifies the light beams to be bypassed in the memory 9, but when all the light beams are specified, a bypass prohibition signal is output from the output control section 19 to the control circuit 3 via the data selector, and the control circuit 3
performs its operation without bypassing any luminous flux.

Further, in the bypass number setting section 14, the output control section 19
It is also possible to set the maximum number of bypasses for which a bypass prohibition signal should be output. This is provided in consideration of safety, and by specifying the number of bypasses as n, n-1, etc. in the bypass number setting section 14 and inputting it to the comparator 13, the data selector 12 When the number of input bypasses matches the designated number of bypasses, a match signal is output to the key control section 15, and a bypass prohibition signal is output from the output control section 19 via the key control section 15.

Furthermore, according to this embodiment, the bypass display section 18 in which the 1-key switch section 16 and the synchronization signal generation section 17 are turned on displays a bypass display indicating that bypass is in progress, and the operator is asked to confirm this display. This allows the press equipment to operate more reliably.

The present invention is not limited to the above embodiments, and the manual switch of the synchronization signal generator 17 is turned on.

In addition to turning off the switch, the switch can also be similarly driven by inputting a signal having the same period as that of the rotating section using an oscillator or the like. Furthermore, although the key control section 15 is configured using a NAND gate 20, a flip-flop 21, etc.,
Of course, it can be configured using other gate circuits.

(7) Effects of the Invention As explained in detail above, according to the present invention, even if the bypass position signal is input by mistake when bypassing the light beam, the person in charge or the like inputs the key switch. This is especially effective in avoiding dangerous situations when a signal that bypasses all the light beams is input by mistake.

Further, by providing a simple key switch in the 1111i1 bypass circuit, a safer safety device can be realized.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a bypass circuit, FIG. 2 is a block diagram of a press safety device, and FIG. 3 is a circuit diagram of a key control unit, etc. 1...Light emitter, 2...Light receiver 33...Control circuit, 4...Bypass circuit,
5...Press emergency stop device. 7... Input control section, 8... Light reception display section. 9...Memory, 10...Bypass position setting section, 11...Bypass position display section. 12...Data selector, 13...Comparator, 14...Bypass number setting section. 15...Key control section, 16...Key switch section, 16a...Key switch. 17... Synchronization signal generation section, 17a... Switch, 18... Bypass display section. 19... Output control unit, 20... AND gate, 21... Reset set free knob flop circuit, 22... Inverter. 23...Resistance.

Claims (1)

[Claims] a light flux creating means for creating a plurality of light fluxes, and transmission of the light flux;
a detection means for detecting an abnormality by blocking; a bypass means for determining that the light beam is normal even if the light beam is transmitted or blocked; a memory means for storing a designated bypass position of the light beam; A safety device comprising: switching means for storing a position; and synchronization prevention means for periodically inhibiting operation of the bypass means.