JPH0882399A - Light beam safety device self-check device - Google Patents

Abstract

(57) [Abstract] [Purpose] A self-check system for a light beam safety device that is related to a light beam safety device for a press machine, and in particular can control the light beam safety device using a microcomputer and at the same time check the operation of the entire system. I will provide a. [Structure] A pseudo light-shielding signal is output to a switch circuit for connecting and disconnecting a drive signal of a press machine, the light beam safety device, or a light shielding detection circuit, and a light shielding detection signal is input from the light beam safety device or the light shielding detection circuit. A high-level signal, which is one of a microcomputer, the light-shielding detection signal, and an effective / ineffective switching signal of the light beam type safety device output from the microcomputer, is input, and an opening / closing signal thereof is output to the switch circuit. Check that the check system is normal on the microcomputer.
And an RS flip-flop circuit that outputs an abnormality identification signal.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light beam safety device for a press, and more particularly to a self-check device for confirming the operation of the entire device, not a part thereof.

[0002]

2. Description of the Related Art A light beam type safety device is used in a press machine or the like for ensuring safety. This ray-type safety device projects multiple rays into the dangerous area, and when these rays are blocked by a part of the human body, etc., it outputs a sudden stop signal, and this signal causes the slide etc. of the press machine to It is designed to be stopped. By the way, in the above-mentioned light beam type safety device, if an abnormality occurs in a light emitting element that projects a light beam, a light receiving element that receives this light beam, or peripheral circuits thereof, the safety device cannot function. In view of the above situation, a device for detecting an abnormality in a light-emitting element or a light-receiving element (Japanese Patent Application No. 52-80212 / invention “fault detection device for light beam safety device”) and a light-emitting element have been conventionally used. A device for detecting an abnormality in a light receiving element or a light receiving element and also checking these peripheral circuits and the like (Japanese Patent Application No. 4-20362).
・ The title of the invention, "self-check device for light beam safety device of press machine", etc., has been devised. Next, Japanese Patent Application No. 4-
A brief description of the 20362 will be given with reference to FIG. 2. A plurality of light emitting elements and light receiving elements are arranged to face each other through a predetermined dangerous area, and the light emitting elements project onto the light receiving element through the dangerous area. A self-check device 32 of the light beam safety device 31 of the press machine, which is designed to generate a sudden stop signal to a predetermined device when the interruption of two or more light beams is detected based on the output of the light receiving element. In the above, the operation of the light emitting element and the light receiving element is checked by setting the light beams in a pseudo optical axis abnormal state one by one while the press machine is in operation.
Further, even while the press machine is on standby, each of the light beams is artificially made into an abnormal optical axis state to check the operation of the light emitting element and the light receiving element, and at the same time, a pseudo drive signal is applied to the sudden stop circuit 35. The operation of the sudden stop circuit 35 is checked.

[0003]

However, the above-described conventional self-check device for the light beam safety device is excellent in that the operation check can be performed while the press machine is in operation. This is a check of a part of the apparatus, and the operation of the sudden stop circuit 35 is checked when two or more of the plurality of light beam axes are simultaneously shielded from the timer circuit 47 that drives the sudden stop circuit 35 and its periphery. There was a problem that it was not the whole check.

Focusing on the above-mentioned conventional problems, the present invention makes it easy to confirm the operation of the entire self-check device of the light beam safety device by utilizing the standby state of the press machine, and it is possible to improve the reliability. The purpose of the present invention is to provide a self-check device for light beam safety devices.

[0005]

In order to achieve the above object, in the first aspect of the invention, a plurality of light emitting elements and light receiving elements are arranged to face each other through a predetermined danger area, and the danger area is separated from the light emitting element. When a cutoff of two or more light rays projected onto the light receiving element via the light receiving element is detected based on the output of the light receiving element, a sudden stop signal is output to the driving device of the press machine. By sequentially inputting a safety device and a pseudo signal for causing a ray axis blocking state for each of the plurality of ray axes to the ray type safety device in sequence, a light blocking state is artificially generated for each ray axis. When it is confirmed that the light beam safety device has normally operated in the pseudo light-shielded state for all the light beam axes, a press machine equipped with a self-check circuit that outputs a self-check completion signal for all axes is used. In addition, two or more of the plurality of light beam axes are simultaneously shielded by being driven by the standby self-check start circuit for checking the entire device during press standby and the output signal of the standby self-check start circuit. After confirming that the optical axis abnormality and light blocking state generation circuit that artificially creates a state, the sudden stop circuit, the timer circuit for driving the sudden stop circuit, and the device operate normally, turn on the sudden stop circuit. It is configured by a sudden stop reset circuit for setting a reset state.

According to the second aspect of the invention, a plurality of light emitting elements and light receiving elements are arranged facing each other through a predetermined dangerous area, and two or more light emitting elements are projected onto the light receiving element through the dangerous area. When the interruption of the light beam is detected on the basis of the output of the light receiving element, a light safety device of the press machine configured to generate a sudden stop signal to the drive device of the press machine, and each of the plurality of light beam axes. By sequentially inputting a dummy signal for generating a light beam axis cutoff state one by one to the light beam safety device, a light blocking state is artificially generated for each light beam axis, and the light beam safety device is operated against the pseudo light blocking state. After confirming that all the optical axes have operated normally, in a press machine equipped with a self-check circuit that outputs a self-check completion signal for all axes, the entire machine is checked while the press is waiting. A self-check start circuit during standby for driving, a light-shielding and optical axis abnormal state generation circuit that is driven by the output signal of the self-check start circuit during standby to artificially create an abnormal state of the optical axis, and a sudden stop circuit, The timer circuit for driving the sudden stop circuit and the sudden stop reset circuit for putting the sudden stop circuit into a reset state after confirming that the device operates normally are configured.

[0007]

According to the structure of the first aspect of the invention, the light-shielding and optical axis abnormal state generating circuit is driven by the output signal of the self-check start circuit during standby of the press machine so that the light-shielding and optical-axis abnormal state generating circuit operates on the plurality of light-beam axes. When two or more of them are artificially made to be shielded from light at the same time, the light beam safety device outputs a light-shielding detection signal and is applied to the sudden stop circuit. You can check whether is working properly.

Further, according to the configuration of the second invention, the light-shielding and optical-axis abnormal state generating circuit driven by the output signal of the self-check start circuit during standby while the press is in standby, When the abnormal state of is artificially created, the self-check circuit does not output the all-axis self-check completion signal, so the timer circuit is not reset and a time-up signal is output and applied to the sudden stop circuit. It is possible to confirm whether the device operates normally by operating the sudden stop circuit.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a self-check device for a light beam safety device of a press according to the present invention will be described in detail below with reference to the drawings.

FIG. 1 shows an embodiment of the present invention in which a light beam type safety device 1 has a plurality of light emitting elements and light receiving elements facing each other through a predetermined danger area, and the light emitting element is connected to the danger area. When the interruption of two or more light rays projected onto the light receiving element via the light receiving element is detected based on the output of the light receiving element, the light blocking detection signal QST is output. The light-shielding detection signal QST is input to the sudden stop circuit 5 via the OR gate 4 in the press controller 3, whereby the press machine is suddenly stopped. In this case, the light beam safety device 1 treats the light-shielding state due to a part of the actual body and the pseudo-light-shielding state by the self-check while the press is in operation and on standby as described below in the same manner. However, when there are two or more light shields of a plurality of ray axes, the light shield detection signal QST
Is output.

The self-check circuit 2 performs a self-check of the light beam safety device 1 when a self-check start signal LA is input from the press controller 3 via the AND gate 10. By sequentially inputting a pseudo signal that causes an abnormal state of the optical axis to each of the plurality of optical axes to the optical safety device, the abnormal state of the optical axis is pseudo-generated for each optical axis, and the pseudo state is generated. When it is confirmed that the light beam safety device has normally operated with respect to the abnormal state of all the light beams for all the light beam axes, the all-axis self-check completion signal LZ is output. However, the all-axis self-check completion signal LZ is not output when it is confirmed that the single optical axis does not operate normally in the pseudo optical axis abnormal state.

Further, the self-check circuit 2 simulates two or more light ray axes of the plurality of light ray axes of the light ray type safety device 1 when the light axis shielded state generation signal LB is inputted from the press controller 3. When the light-shielding device 1 is in a light-shielded state and is detected by the output of the light receiving element of the light-beam safety device 1, the light-beam safety device 1 outputs a light-blocking detection signal QST.

Further, when the optical axis abnormal state generation signal LC is input from the press controller 3, the self-check circuit 2 artificially sets one or more of the optical axes of the plural optical axes of the optical safety device 1. When an abnormal state is detected in the above condition and this is detected by the self-check by the self-check start signal LA, the all-axis self-check completion signal LZ is detected.
Is not output. The IN signal output from the self-check circuit 2 becomes "0" when the self-check start signal LA is input, and the self-check completion signal L for all axes is output.
This signal rises to "1" at the same time as the Z output.

The AND gate 6 is for judging the self-check activation condition during press standby. The restart prevention signal is off and the slide standby point signal indicating that the slide standby point is located is on. When various abnormalities do not occur and there is no jogging or one jogging process, the AND condition is satisfied and the standby self-check start circuit is activated.

The AND gate 8 is for determining the self-check starting condition during the press operation. The restart prevention signal is ON and various abnormalities have not occurred. When the valve is on, the AND condition is satisfied, and the operating self-check start circuit 9 is activated.

The standby self-check start circuit 7 controls the start of the self-check of the light beam type safety device when the press machine is not in operation, and when a start signal is input from the AND gate 6. The self-check start signal LA is output.

The operating self-check start circuit 9 controls the start of the self-check of the light beam safety device when the press is actually operating, and the AND gate 8
When a start signal is input from, the self-check start signal LA is output. During this operation, the self-check by the self-check start circuit 9 is repeatedly executed at a predetermined cycle unless an abnormality occurs.

The optical axis shading / abnormal state generation circuit 11 is driven by the output LA of the self-check start circuit 7 during standby, and first outputs the optical axis shading state generation signal LB and applies it to the input of the self-check circuit 2. When the optical axis light blocking state generation signal LB is input, the self-check circuit 2 sets two or more light beam axes of the plurality of light beam axes of the light beam safety device 1 in a pseudo light blocking state, When detected by the output of the light-receiving element of the light beam safety device 1, the light beam safety device 1 outputs a light-shielding detection signal QST, which is applied to the sudden stop circuit 5 via the OR gate 4 so that the sudden stop circuit 5 operates normally. Check if it works. When the confirmation of the operation of the sudden stop circuit 5 is completed, the sudden stop circuit 5 is reset by the sudden stop reset circuit 12.

When the operation check of the abrupt stop circuit 5 by the optical axis light shielding state generation signal LB is completed and the reset of the abrupt stop circuit 5 is confirmed, the optical axis light shielding and abnormal state generation circuit 11 is next operated. Stop the optical axis blocking state generation signal LB,
The optical axis abnormal state generation signal LC is output and applied to the input of the self-check circuit 2. At the same time, the optical axis abnormal state generation signal LC is applied to the set terminal of the timer circuit via the OR gate 13, and the timer 17 starts counting. When the optical axis light shielding state generation signal LC is input, the self-check circuit 2 sets one or more light ray axes of the plurality of light ray axes of the light ray safety device 1 into a pseudo abnormal state, and sets this to the self-state. When the self-check with the check start signal LA is detected, the self-check completion signal LZ for all axes is sent.
Is not output. All-axis self-check completion signal LZ
If is not output, the timer circuit 17 is not reset, so a time-up signal is output to drive the sudden stop circuit 5 to check whether it operates normally.

The operation preparation completion confirmation circuit 16 confirms that various conditions for starting the press machine are satisfied. However, the operation preparation completion confirmation circuit 16 must be in the ON state when the operation end signal output of the optical axis shading and abnormal state generation circuit 11 is not turned on (the check is completed at this time and the sudden stop state is released). Is not output.

The timer circuit 17 is for detecting an abnormality of the light beam axis of the light beam safety device 1, and starts self-timer operation by the self-check start signal LA, and self-checks all axes even if a preset predetermined time elapses. When the check completion signal LZ is not input, the time-up signal is output to operate the sudden stop circuit 5.

The sudden stop reset circuit 12 is a circuit for resetting the sudden stop state. It is connected to a sudden stop reset button (not shown), and the sudden stop state is not released unless the sudden stop reset circuit 12 is set.

The operation of the configuration shown in FIG. 1 will be described below.

First, a description will be given of the light beam safety device on standby of the press, the self-check circuit, and the self-check of the press controller.

When the various conditions input to the AND gate 6 are satisfied, the AND gate 6 activates the self-check start circuit 7 during standby. As a result, the self-check start signal LA is output from the self-check start circuit 7 during standby. This self-check start signal LA is sent to the self-check circuit 2 via the OR gate 10.
The self-check of the light beam safety device 1 is started by the self-check circuit 2. In addition,
The self-check start signal LA is a signal that remains on during the self-check period.

The self-check circuit 2 sequentially inputs a pseudo signal to the light beam safety device 1 to generate a light beam axis abnormal state, one for each of the plurality of light beam axes of the light beam safety device 1. A light blocking state is pseudo-generated for each light beam, and it is confirmed that the light beam safety device is normally operated with respect to the pseudo light blocking state, one for each light ray axis.

On the other hand, the self-check start signal LA
Is input to the optical axis shading and abnormal state generation circuit 11 to activate the optical axis shading and abnormal state generation circuit 11. As a result, the optical axis shading / abnormal state generation circuit 11 first outputs the optical axis shading state generation signal LB and applies it to the input of the self-check circuit 2. When the optical axis light blocking state generation signal LB is input, the self-check circuit 2 sets two or more light beam axes of the plurality of light beam axes of the light beam safety device 1 in a pseudo light blocking state, When detected by the output of the light-receiving element of the light beam safety device 1, the light beam safety device 1 outputs a light-shielding detection signal QST, which is applied to the sudden stop circuit 5 via the OR gate 4 so that the sudden stop circuit 5 operates normally. Check if it works. Further, the optical axis light shielding state generation signal LB is applied to the reset terminal of the sudden stop reset circuit 12 via the OR gate 19 to reset the sudden stop reset circuit 12 to the sudden stop state. At this time, since the press machine is on standby, the press machine is originally in a stopped state, and the sudden stop circuit 5 only performs an idle operation. When the confirmation of the operation of the sudden stop circuit 5 is completed, the sudden stop circuit 5 outputs a sudden stop reset signal. The sudden stop reset signal of the sudden stop circuit 5 is a pulse signal that is output only when a pseudo sudden stop is applied during the self-check during standby.

The sudden stop reset signal is applied to the optical axis shading / abnormal condition generation circuit 11, the optical axis shading / abnormal condition generation circuit 11 stops the optical axis shading state generation signal LB, and outputs the optical axis abnormal state generation signal LC. Output. At the same time, the sudden stop reset signal is also applied to the set terminal of the sudden stop reset circuit 12, and the sudden stop reset circuit 12 is set. The optical axis abnormal state generation signal LC is applied to the self-check circuit 2 and at the same time drives the timer circuit 17 via the OR gate 13, and the timer circuit 17 starts counting. When the optical axis abnormal state generation signal LC is input, the self-check circuit 2 makes one or more ray axes of the plurality of ray axes of the ray-type safety device 1 pseudo-abnormal state, and sets this as the self-state. When the self-check is detected by the check start signal LA, the all-axis self-check completion signal LZ is not output. If the all-axis self-check completion signal LZ is not output, the timer circuit 17 is not reset. Therefore, a time-up signal is output to drive the sudden stop circuit 5 to check whether it operates normally. In this case as well, the press machine is on standby, and therefore only idle operation is performed. In addition, because it is in a standby state, the sudden stop circuit 5 outputs the sudden stop reset signal to set the sudden stop reset circuit 12 to the set state as described above. At the same time, the sudden stop reset signal is also applied to the optical axis shading / abnormal state generating circuit 11 to stop the output of the optical axis shading state generating signal LC. At this time, at the same time, the optical axis shading and abnormal state generation circuit 11 outputs an operation end signal.

On the other hand, the self-check circuit 2 is applied with the self-check signal LA and is performing self-check. However, since neither the optical axis shielded state generation signal LB nor the optical axis abnormal state generation signal LC has already been applied,
When it is confirmed that the check results are normally completed for all the ray axes, the self-check completion signal LZ is output, and at the same time, the IN signal rises to "1". The IN signal output from the self-check circuit 2 becomes "0" at the same time as the self-check start signal LA is input,
"1" when outputting all-axis self-check completion signal LZ
It is a signal to stand up.

A of the AND gate 14 is generated by the IN signal.
When the ND condition is satisfied, the self-check end signal output from the AND gate 14 is applied to the waiting self-check start circuit, and the waiting self-check ends.

On the other hand, the IN signal which is the output of the self-check circuit 2 and the optical axis shading / abnormal state generating circuit 11
By the operation end signal output from the
Since the ND condition is satisfied, the operation preparation completion confirmation circuit 16 inputs the signal "1" to the AND gate 20 when the various conditions for starting the press machine are satisfied by the output of the AND gate 15. Therefore, after this, when the operator presses the start button and inputs the start command, the clutch of the clutch brake 21 is engaged and the slide starts to operate.

During the self-check during the standby, if the self-check of the light beam axis of the light beam safety device is not normally completed, the IN signal does not rise, so that the operation ready state will not be reached and the press Cannot be started. In addition, even when the operations of the timer circuit 17 and the sudden stop circuit 5 are not normal, the optical axis blocking and abnormal state generation circuit 1
Since the operation end signal 1 is not output, the operation is not ready and the press cannot be started.

[0033]

As described above in detail, according to the present invention, in the self-checking device for the light beam safety device, all the parts including the light beam safety device, the self-check circuit, and the press controller are suddenly stopped. Since it is possible to perform a self-check on a place where it is difficult to perform a conventional self-check, such as a circuit, the reliability of the light beam safety device can be significantly improved.

[Brief description of drawings]

FIG. 1 is a diagram showing a control circuit of a self-check device of a light beam type safety device in an embodiment of the present invention.

FIG. 2 is a diagram showing a conventional technique.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Light safety device, 2 ... Self-check circuit, 3 ... Press controller, 4 ... OR gate, 5 ... Sudden stop circuit, 6 ... AND gate, 7 ...
..Self-check start circuit during standby, 8 ... AN
D gate, 9 ... Self-check start circuit during operation, 10 ... OR gate, 11 ... Optical axis shading and abnormal state generation circuit, 12 ... Sudden stop reset circuit, 13
... OR gates, 14, 15 ... AND gates, 1
6 ... Operation ready confirmation circuit 17 ... Timer circuit, 18 ... AND gate, 19
... OR gate, 20 ... AND gate, 21 ...
・ Clutch brake.

Claims (2)

[Claims] 1. A plurality of light emitting elements and light receiving elements are arranged to face each other through a predetermined dangerous area, and two or more light beams projected from the light emitting element to the light receiving element through the dangerous area are blocked. When is detected based on the output of the light receiving element, in the self-check device of the light beam safety device of the press machine, which is configured to generate a sudden stop signal to a predetermined device,
Simulates a state in which two or more of the light beam axes are simultaneously shielded by being driven by the output signal of the standby self-check start circuit for checking the device during press standby and the standby self-check start circuit. The optical axis abnormality and light-shielding state generation circuit that is created dynamically, the sudden stop circuit, the timer circuit for driving the sudden stop circuit, and the sudden stop circuit are reset after confirming that the device operates normally. A self-check device for a light beam type safety device, which comprises a sudden stop reset circuit for performing the operation. 2. A plurality of light emitting elements and light receiving elements are arranged to face each other through a predetermined dangerous area, and two or more light beams projected from the light emitting element to the light receiving element through the dangerous area are blocked. When is detected based on the output of the light receiving element, in the self-check device of the light beam safety device of the press machine, which is configured to generate a sudden stop signal to a predetermined device,
Standby self-check start circuit for checking the device during press standby, and light-shielding and optical axis abnormal state generation circuit that is driven by the output signal of the standby self-check start circuit to artificially create an abnormal state of the optical axis And a sudden stop circuit, a timer circuit for driving the sudden stop circuit, and a sudden stop reset circuit for putting the sudden stop circuit into a reset state after confirming that the device operates normally. Self-check device for light beam safety device.