JPS5819918B2 - Kousakukino Anzensouchi - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a safety device for machine tools such as press machines, and includes a large number of light emitters and light receivers that can cover the monitored range of the machine tool, and switches each light emitter in sequence. Along with emitting light,
Each light-receiving section is also switched accordingly, so that when a worker accidentally inserts his or her hand into the monitored area, it immediately detects that the corresponding light-receiving section has no output, and the machine tool is automatically activated. It is designed to automatically and reliably stop.

An embodiment of the present invention will be described below with reference to the drawings.

In the drawing, 1a to 1n are a large number of light projecting parts, 2 is an oscillator for each of these light projecting parts 1a to 1nK, and 3 is this oscillator 2.
□ is a time division circuit on the light projecting side, that is, a multiplexer, for sequentially switching and inputting the output of the light into each of the light projecting sections 1a to 1n to emit light.

Reference numeral 4 denotes a timing circuit on the emitter side that performs switching of the time division circuit 3 on the emitter side, and reference numeral 5 denotes a timing failure detection circuit.When a failure occurs, the output of the detection circuit 5 controls the operation of the time divider circuit 3 on the emitter side. It is something that makes it stop.

Reference numerals 6a to 6n denote a large number of light receivers that respectively receive light from the respective light projectors 1a to 1n, and 7 denotes a time division circuit on the light receiving side, that is, a multiplexer, which sequentially switches the signals obtained from each of the light receivers 6a to 6n. , 8 is a light receiving side timing circuit which performs switching of the light receiving side time division circuit 7 in synchronization with switching of the light emitting side.

9 is an amplifier circuit for amplifying the output of the light-receiving side time division circuit 7;
Reference numeral 0 designates a fast-cutting circuit that sequentially cuts the outputs quickly so as not to interfere with each other, and 11 indicates a time-division recovery circuit that sequentially returns the output of the quick-cutting circuit 10 to the state before time division based on the output of the light-receiving side timing circuit 8. It is a multiplexer.

12 is an amplifier failure detection circuit, and 13 is a light receiving side timing failure detection circuit, each of which short-circuits the output side of the time division recovery circuit 11 with their respective outputs.

Reference numerals 14a to 14n refer to a large number of memories, such as capacitor memories, which sequentially store each output of the time-division recovery circuit 11. Reference numeral 15 uses, for example, an AND gate to issue a stop signal when the output of any one of the memory IJs 14a to 14n disappears. This is a danger detection circuit.

The fast-actuation circuit 10 is configured to pulse only the leading and trailing edge portions of each positive oscillation signal among the oscillation signals supplied from the amplifier 9, for example.

Thus, the output of the oscillator 2 is sequentially switched and inputted to each of the light projecting sections 1a to 1n via the light projecting side time division circuit 3 which is switched by the light projecting side timing circuit 4, and the light projecting sections 1a to 1n are sequentially caused to emit light. It will be done.

The light from the light emitting sections 1a to 1n, which are switched to emit light sequentially, is sequentially received by the light receiving sections 6a to 6n, and the oscillation signal obtained from this is amplified via the light receiving side time division circuit 7, which is switched by the light receiving side timing circuit 8. The signals are sequentially applied to the circuit 9 and amplified, and of the amplified output, the leading and trailing edge portions of each positive oscillation signal are converted into pulses by the fast cutting circuit 10 and supplied to the time division recovery circuit 11.

That is, by quickly cutting off the output of each light receiving section at the trailing edge of each positive oscillation signal and supplying it to the time division recovery circuit 11, the residual output of the immediately preceding light receiving section becomes the pseudo output of the subsequent light receiving section. So-called channel crosstalk will no longer occur.

The output of the fast-cutting circuit 10 is sequentially returned to the state before time division by the time division return circuit 11 based on the pulse output for selecting the aforementioned leading edge and trailing edge partial pulses generated from the light receiving side timing circuit 8. Memo IJ 14 a~14n
The data is stored in the storage area and then added to the danger detection circuit 15.

Now, if the light from each of the light emitters 1a to 1n is unobstructed and sequentially enters each of the light receivers 6a to 6n, an input signal is added to each memo IJ14a to 14n in response to this, and each Since an output is generated, a stop signal is not issued when the AND condition of the danger detection circuit 15 is satisfied, and, for example, the press machine is not stopped.

If a worker accidentally inserts his or her hand into the cutter section of the press (within the monitored area), the light between the light emitter and light receiver at this location
For example, the light between the light projecting section 1b and the light receiving section 6b is blocked, and a signal cannot be obtained from the light receiving section 6b, and correspondingly, no signal is applied to the memory 14b.

Note the results! Since the output of J14b disappears, as soon as it disappears, the hazard detection circuit 15 AND condition is not satisfied, and a stop signal is issued, and the press is thereby stopped, thereby ensuring the safety of the workers.

Note that it is natural to provide a timing circuit for timing the light emitting side and the light receiving side, but this may be provided separately or in common.

As described above, according to the present invention, a large number of light emitters and light receivers are provided to cover the monitored range of a machine tool, and each light emitter is sequentially switched to emit light, and each light receiver is also switched accordingly. When a worker accidentally inserts his/her hand or other object into the monitored range, it immediately detects that the corresponding light-receiving section has no output, and thereby automatically and reliably stops the machine tool. In addition, the input of each light emitter and the output of each light receiver are processed in a time-sharing manner.
The circuit configuration can be easily miniaturized.

Furthermore, if a failure detection circuit is provided in the main part of each circuit, an extremely reliable safety device can be provided.

[Brief explanation of drawings]

The drawing is a block diagram showing the configuration of an embodiment of the device of the present invention. 1a to 1n... Light emitter, 2... Oscillator, 3... Light emitter side time division circuit, 6a to 6n...
... Light receiving section, T ... Light receiving side time division circuit, 10
...Fast cut circuit, 11... Time, division return circuit, 14a to 14n... Memory, 15...
...Danger detection circuit.

Claims (1)

[Claims] 1 A large number of light projectors, an oscillator common to these light projectors, a time division circuit on the light projecting side for sequentially switching and inputting the output of this oscillator to each light projecting section to emit light, and each light projecting section a large number of light receiving sections that each receive light from different sources, and a time division circuit on the light receiving side that sequentially switches and outputs the signals obtained from each of the light receiving sections.
A quick-cut circuit that sequentially cuts off the outputs of the light-receiving side time-division circuits quickly so as not to interfere with each other, a time-division recovery circuit that sequentially returns the outputs of the quick-cut circuit to the state before time-division, and each output of this time-division recovery circuit. A machine tool safety device consisting of a large number of memories that store information in sequence and a danger detection circuit that issues a stop signal when the output from each memory is exhausted.