JPH0530880Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) This invention is a detection device that detects failures and abnormalities in electric circuits in friction press machines, and can be used by connecting to conventional press machines that are not equipped with a detection device. .

(Prior art) The electric circuits in today's friction press machines detect when electrical parts such as relays and limit switches break down or are damaged, and either stop the machine suddenly or prevent it from restarting, or issue an alarm. Structural standards require that equipment be equipped with a failure detection device (safety device) that alerts workers.

However, the electrical circuits of conventional friction press machines based on the old standards do not incorporate any of the above-mentioned detection devices, so if the clutch, brake control relay, or limit switch of the press malfunctions, it can immediately lead to an accident. It has a problem that is said to be extremely dangerous.

However, in order to improve the electrical circuits of conventional presses based on those old standards to meet today's standards, it would cost a considerable amount of money and the presses would have to be stopped for two to three days to install these devices. It has a defect that makes it necessary.

(Problems to be Solved by the Invention) In view of the conventional circumstances as described above, the present invention aims to provide a failure detection device that can be easily installed in a conventional press without stopping the operation of the press for several days. be.

(Means for Solving the Problems) The technical means of the present invention for solving the above problems makes it possible to electrically connect a separately configured detection circuit without changing the main electric circuit in a conventional press machine. It has a fault detection circuit made up of multiple relays, a ready-to-operate indicator light that turns off before top dead center and turns on when the machine stops in place if there is no abnormality, and a cam that rotates when the press operates. and a detection means consisting of a limit switch disposed around the cam, and an on/off switch that connects the detection circuit to the electric circuit of the press machine.

(Function) The failure detection device configured as described above disconnects and connects the on/off switch of the detection device to the emergency stop circuit in the electric circuit of the press machine, and further prevents restart in the electric circuit of the press machine. The b contacts of the clutch and brake relays are connected in series to the emergency stop circuit relay of this detection device, and each of the above in this device is connected to the restart prevention relay, clutch, and brake relay circuits in the conventional electric circuit. Connect the monitoring relays of the relays in parallel, and connect the contact on the side that is not used to disable the rise of the limit switch for one safety stroke of the conventional machine to the monitoring relay of the limit switch in this device, and By connecting the wires using the common line of the circuit and turning on the off/on switch, the conventional electric circuit can be energized through this detection device and the press can be operated, which can prevent failures of the clutch, relay that controls the brake, and limit switch. becomes detectable. In addition, when the on/off switch is set to ``off'', operation is possible using the conventional electric circuit, and in particular, when an abnormality in the electric circuit is detected with the on/off switch set to ``on'', clutch operation cannot be performed through this detection device. Since this cannot be done, we use the inching of the conventional circuit and
It is designed for continuous operation.

(Example) Hereinafter, an example of the present invention will be described based on the drawings.

Fig. 1 shows a failure detection device for a press machine equipped with a combination type clutch and a brake. Relay 2X for monitoring relay 2R,
Detection circuit auxiliary relay 3X, electrical circuit B emergency stop circuit connection and restart prevention relay 1R, clutch, brake relay 2R malfunction detection relay 4X, electrical circuit B emergency stop circuit connection and detection circuit relay Relay 5X for detecting malfunction of
6X, operation preparation relay 7X, limit switch LS-1 monitoring relay 8X for preventing restart of electric circuit B, limit switch LS-5 for safety single stroke
A failure detection circuit A consisting of each relay of the monitoring relay 9X, an operation ready indicator C connected to the circuit of this detection circuit A, and a crankshaft
A rotating cam D attached to D' and a limit switch LS-3 disposed around the cam D that turns ON and OFF as the cam D rotates to confirm that it has stopped at a fixed position and to detect faulty relay and limit switch operation.
It consists of a detection means consisting of LS-4, and an on/off switch E of the present detection device which disconnects the emergency stop circuit of electric circuit B and connects between the emergency stop circuit.

FIG. 2 shows a failure detection device for a press machine equipped with an electric circuit B' in which a separate clutch and a relay for controlling each brake are separately provided.
X is added to the circuit shown in the previous embodiment, and the same members as shown in the previous embodiment are given the same reference numerals and explanations will be omitted.

Next, we will explain the state in which the above-mentioned failure detection device is connected to the electric circuit B or B' of the press machine.
First, disconnect the emergency stop circuit in electric circuit B or B', and during this time, connect the terminals of the on/off switch E,
Connect the b contacts of restart prevention relay 1R, clutch, and brake relay 2R in electric circuit B to connect the emergency stop circuit in the detection circuit and malfunction of restart prevention relay 1R, clutch, and brake relay 2R. Connect between the terminals in the circuit of detection relay 4X. In the case of the electric circuit B' having a separate brake relay 3R, the b contact of the brake relay 3R is connected between the circuits of the detection relay 4X as described above. Furthermore, electric circuit B
Connect monitoring relays 1X and 2X in parallel to the restart prevention relay 1R, clutch, and brake relay 2R circuits through terminals.
In the case of electric circuit B' where brake relay 3R is separately provided, brake relay 3R is installed separately.
The monitoring relays 10X of R are connected in parallel through terminals. In addition, the contact on the side that is not used to disable the rise of the limit switch LS-5 for one stroke of safety in the electric circuit B or B' is connected to the monitoring relay 9X in the detection circuit by a terminal, and the detection circuit is Connect to the terminal using the common line of circuit B or B'.

In addition, the above-mentioned on/off switch E is connected to the electric circuit B or
This can also be done using the operation mode selector switch and relay in B'.

In that case, connect a relay for one stroke and a safety relay for one stroke in parallel instead of (ON) in the OFF/ON switch E in the circuit shown in Figures 1 to 3, and use relay for inching instead of (OFF). By connecting the relay and the interlocking relay in parallel, it can be turned off in conjunction with the operation mode selection switch of electric circuit B or B' installed on the press side.
It is possible to perform “input”.

Next, the operation of the failure detection device connected as described above will be explained.

[1] When energized When the press is stopped at the fixed position, the electric circuit B or
Turn on the operation mode selector switch (not shown) installed in B', and turn on the operation preparation button F of this device.
When the operation preparation relay 7X is turned on, the emergency stop circuit connection and detection circuit relay malfunction detection relay 6X is turned on, and the detection circuit auxiliary relay 3 is turned on.
Connection of X and emergency stop circuit, relay 1R for restart prevention, relay 4X for detecting malfunction of clutch and brake relay 2R are turned ON, and electric circuit B
Or B' restart prevention relay 1R and limit switch LS-5 monitoring relay 9 for safety one stroke.
When X is turned on, the operation ready indicator light C lights up and operation preparation is completed.

[2] Press operation When the operation button G of electric circuit B or B' is turned ON, the clutch and brake relay 2R are turned ON, and the monitoring relay 8X of the restart prevention limit switch LS-1 is turned ON, and the clutch is engaged. .
Also, the monitoring relay 2X of the clutch and brake relay 2R is turned on, and the restart prevention relay 1R is turned on.
The monitoring relay 1X is turned on, and the limit switch is activated to confirm that it has stopped at the fixed position and to detect malfunction of the relay.
LS-3, limit switch for checking relay operation
LS-4 respectively operate, and relay 5X for connecting the emergency stop circuit and detecting malfunction of the detection circuit relay
The detection circuit auxiliary relay 3X, the restart prevention relay 1R and clutch, the malfunction detection relay 4X of the brake relay 2R, and the malfunction detection relay 6X are turned OFF, and the limit switch for disabling the rise of one safe stroke is turned OFF. LS-5 operates and limit switch LS-5 monitoring relay 9X turns OFF.
becomes. Also, limit switch LS for restart prevention.
-1 is activated, the restart prevention relay 1R and its monitoring relay 1X are turned OFF, and at the same time as the fixed position stop limit switch LS-2 is activated, the monitoring relay 8X of the restart prevention limit switch LS-1 is activated. The circuit is held, and the clutch and brake relay 2R are turned OFF, and the clutch is turned OFF.
The clutch, brake relay 2R, and limit switch LS-2 monitoring relay 2X for fixed position stop are turned OFF, and malfunction detection relay 6X is turned ON, confirming fixed position stop and relay operation. While the fault detection limit switch LS-3 returns to normal, the operation ready indicator light C turns off (same state as when the emergency stop button is pressed). Furthermore, to reset the limit switch LS-3, the detection relay 5X is turned OFF, the detection circuit auxiliary relay 3X and the detection relay 4X are turned ON, the restart prevention relay 1R is turned ON, and the operation preparation indicator light C is turned on.
lights up and the device is ready to restart.

[3] When an error occurs (3-1) Restart prevention limit switch LS-
Malfunction of 1 (burned out when contact A is ON) When restart prevention limit switch LS-1 is burned, restart prevention relay 1R and its monitoring relay 1X are turned on, and limit switch LS-2 for fixed position stop is turned on. When it operates, the clutch and brake relay 2R are turned OFF, the clutch is turned OFF, and the press stops at the fixed position. In addition, the monitoring relay 2X of the clutch and brake relay 2R is turned OFF by the operation of the fixed position stop limit switch LS-2.
, detection relay 6X turns on, and restart prevention limit switch LS-1 monitoring relay 8X turns on.
is turned OFF, and the limit switch LS-3 is used to confirm that it has stopped at a fixed position and to detect malfunction of the relay.
is restored and malfunction detection relay 5X turns on.
However, the detection circuit auxiliary relay 3X and malfunction detection relay 4X are turned OFF, making it impossible to restart.

Furthermore, if the restart prevention limit switch LS-1 burns out while the push button is kept pressed in the ON state,
Restart prevention relay 1R and its monitoring relay 1X are turned on, and limit switch LS for stopping in place is turned on.
-2 operates and clutch, brake relay 2R
and its monitoring relay 2X turns ON, limit switch LS-3 for confirming fixed position stop and detecting relay malfunction returns, and detection relay 5X turns on.
and 6X turns on. When the detection relay 6X is turned on, the press suddenly stops and overruns the fixed position. In addition, relay 1 is turned on by turning on detection relay 6X.
R, 1X, 2R, 2X are turned OFF, detection relay 5X is also turned OFF, detection circuit auxiliary relay 3X and detection relay 4X are turned ON, and limit switch LS is turned OFF.
-3 is activated, and detection relays 6X, 3X, and 4X are activated.
However, even if the push button is turned off, restart prevention relay 1R is turned on, and detection relays 6X and 3X are turned on.
It becomes OFF and cannot be restarted. Furthermore, when the restart prevention relay 1R is turned on, the emergency stop circuit detection relay 4X is turned on (held by the limit switch LS-4), and the detection circuit auxiliary relay 3X is also turned on.

(3-2) Limit switch LS for restart prevention
-1 malfunction (A contact OFF state) In this case, operation is impossible (3-3) Limit switch LS for stopping at fixed position
-2 malfunction (burned when the A contact is ON) When limit switch LS-2 for fixed position stop is seized, the clutch, brake relay 2R and its monitoring relay 2X are turned ON, which confirms fixed position stop and Limit switch LS-3 for detecting malfunction of the relay returns to normal state, and detection relays 5X and 6X turn ON. When the detection relay 6X is turned on, the press suddenly stops and overruns the fixed position. or,
Relays 2R and 2X turn on when detection relay 6X turns on.
turns OFF, detection relay 5X also turns OFF, detection circuit auxiliary relay 3X, detection relay 4X, and restart prevention relay 1R turn ON, limit switch LS-3 operates, and detection relay 6X, 3X turns OFF.
is turned off, while detection relay 4X is turned on, restart prevention relay 1R is turned off, detection relays 3X and 4X are turned on, and detection relay 6 is turned on.
X becomes OFF and cannot be restarted.

(3-4) Limit switch LS for fixed position stop
-2 malfunction (Contact A is OFF) In this case, inching operation (3-5) Malfunction of limit switch LS-5 for disabling the rise of safety 1 process (burned with A contact ON) When the push button is turned ON While the clutch, brake relay 2R, and monitoring relay 2X are ON,
Monitoring relay 9X of limit switch LS-5
OFF, the clutch is engaged, but the monitoring relay 1X of the restart prevention relay 1R is turned OFF, and the limit switch LS-3, which is used to confirm that it has stopped in place and to detect malfunction of the relay, operates, and the detection relays 6X and 3X are activated. It turns OFF, the press suddenly stops, and the detection relay 4X turns ON. Furthermore, when detection relays 6X and 3X are turned OFF, restart prevention relay 1R, its monitoring relay 1X, clutch, brake relay 2R, and its monitoring relay 2X are turned OFF, and detection relays 3X and 4X are turned ON.
On the other hand, the detection relay 6X turns OFF, making it impossible to restart.

(3-6) Malfunction of the limit switch LS-5 for disabling the rise of the first safety stroke (B contact remains in the ON state) In this case, the first safety stroke will move in the entire range.

(3-7) Malfunction of limit switch LS-3 for confirming the stop in the fixed position and detecting malfunction of the relay (burned out when the A contact is ON) Turn on the push button and stop in the fixed position after the above-mentioned intermediate stroke of the press operation When the limit switch LS-2 is operated, the clutch and brake relay 2R are activated.
OFF, the clutch turns OFF, and the press stops at the fixed position, while the limit switch LS for stopping at the fixed position
-2's monitoring relay 2X turns OFF, and accordingly, the malfunction detection relay 6X turns ON, and the limit switch LS-3, which is used to confirm stoppage at a fixed position and detect malfunction of the relay, seizes up and cannot be reset.

Further, due to seizure of limit switch LS-3, detection relay 5X is turned on, and detection circuit auxiliary relay 3X and detection relay 4X are turned off, making it impossible to restart.

(3-8) Malfunction of limit switch LS-3 for checking fixed position stop and detecting relay malfunction (B contact remains ON and does not operate) When the push button is turned on, clutch and brake relay 2R are turned on. While the clutch enters, the clutch,
Monitoring relay 2X of brake relay 2R is ON
and monitoring relay 1X for restart prevention relay 1R.
turns on and limit switch LS-3 malfunctions, and limit switch LS for checking relay operation
-4 works. And detection relays 5X, 6X
turns ON, the detection circuit auxiliary relay 3X and the detection relay 4X turn OFF, and the press suddenly stops.
Relays 1R, 1X, 2R, and 2X turn OFF, limit switch LS-4 returns, and detection relay 5X turns ON. Also, when detection relay 5X is turned on, detection circuit auxiliary relay 3X and detection relay 4X are turned on.
becomes OFF and cannot be restarted.

(3-9) Malfunction of limit switch LS-4 for checking relay operation (burned out when A contact is ON) When the push button is turned on and limit switch LS-4 burns out during the middle stroke of the press operation mentioned above, the detection Relay 5X turns OFF, and detection relay 6
X, detection circuit auxiliary relay 3X, detection relay 4X
Limit switch LS-1 to prevent restart when turned on
operates, while the limit switch LS for disabling the rise of one stroke is activated by turning off the detection relay 5X.
-5 is activated, and its monitoring relay 9X is OFF.
becomes. Furthermore, due to the operation of limit switch LS-1, restart prevention relay 1R and its monitoring relay 1X are turned OFF, and detection relay 6X and
The detection circuit auxiliary relay 3X turns OFF and the press suddenly stops and stops before the fixed position, while the detection relay 4X turns ON and the detection relay 6X turns OFF, making it impossible to restart.

(3-10) Malfunction of limit switch LS-4 for confirming relay operation (contact B remains ON and does not return) After turning on the push button and going through the intermediate steps of the press operation described above, limit switch LS-4 remains operating. When it burns out, detection relay 5X turns ON, detection relay 6X, detection circuit auxiliary relay 3X, and detection relay 4X turn OFF, and limit switch LS-5 for disabling the rise of one stroke of safety operates, and its monitoring relay turns OFF. 9X is turned OFF, and the restart prevention limit switch LS-1 operates. And the restart prevention relay 1R and its monitoring relay 1X are
OFF, limit switch LS for fixed position stop
-2 operates and clutch, brake relay 2R
The monitoring relay 2X turns OFF, the press stops at the fixed position, and the detection relay 6X turns ON.
However, limit switch LS-3 returns and turns on detection relay 5X (held by limit switch LS-4), and detection circuit auxiliary relay 3X and detection relay 4X turn off, making it impossible to restart.

(3-11) Restart prevention relay 1R burns out Even if the push button is turned on and the restart prevention limit switch LS-1 is operated after the above-mentioned mid-stroke of press operation, the restart prevention relay 1R remains in the ON state. In response, its monitoring relay 1X turns OFF, the limit switch LS-2 for stopping at the fixed position operates, and the clutch, brake relay 2R and its monitoring relay 2X turn OFF, leaving the press at its normal position. Stop at. Also, detection relay 6X is turned on, limit switch LS-3 is reset, detection relay 5X is turned off, detection circuit auxiliary relay 3X is turned on, and detection relay 4X is turned on.
becomes OFF and cannot be restarted.

(3-12) Seizing of relay 2R for clutch and brake Even if the push button is turned on and the limit switch LS-2 for stopping at the fixed position operates after the above-mentioned mid-stroke of press operation, the relay 2R for clutch and brake will not work.
The ON state is maintained, and the monitoring relay 2X turns OFF, and the detection relay 6
X turns ON, limit switch LS-3 operates, detection relay 5X turns OFF, the press stops at the fixed position, and detection circuit auxiliary relay 3
X turns ON, detection relay 4X turns OFF, and restarting becomes impossible.

(3-13) Malfunction of monitoring relay 1X of restart prevention relay 1R (a) A contact burnt out and cannot be recovered Turn on the push button, and after the above-mentioned mid-stroke of press operation, restart prevention limit switch LS-1 is activated. When activated, restart prevention relay 1R turns OFF, while its monitoring relay 1X remains ON, and limit switch LS-2 for fixed position stop operates, relay 2R for clutch and brake and its monitoring relay LS-2 operates. Relay 2X turns OFF and the press stops at the fixed position.

Also, when the monitoring relay 2X of the clutch and brake relay 2R is turned off, the detection relay 6X is turned on.
and limit switch LS-1 monitoring relay 8
X turns OFF, limit switch LS-3 operates, turning on detection relays 6X and 5X, and detection circuit auxiliary relay 3X and detection relay 4X turn OFF.
As a result, it becomes impossible to restart.

(b) Does not operate when the B contact is ON When the push button is turned ON, the clutch and brake 2R
is ON and the clutch is engaged, while the monitoring relay 2X of the clutch and brake relay 2R is ON, the monitoring relay 1X of the restart prevention relay 1R is not activated.
In the OFF state, limit switch LS-3 operates and detection relay 6X and detection circuit auxiliary relay 3 are activated.
X is turned OFF, the motor suddenly stops, the detection relay 4X is turned ON, and the detection circuit auxiliary relay 3X is turned ON.
Make it impossible to restart.

(3-14) Malfunction of monitoring relay 2X of clutch and brake relay 2R (a) A contact burnt out and cannot be recovered Turn on the push button, and after the above-mentioned intermediate stroke of the press operation, limit switch LS-2 for fixed position stop is activated. When activated, clutch and brake relay 2R
While the press is turned OFF and stops at the fixed position,
The monitoring relay 2X of the clutch and brake relay 2R remains ON, and the limit switch LS-
3 to turn on the detection relay 6X, and at the same time turn on the detection relay 5X, and accordingly the detection circuit auxiliary relay 3X and the detection relay 4X are turned on.
It becomes OFF and cannot be restarted.

(b) It does not work when the B contact is ON. When the push button is turned on, the clutch and brake relay 2R are turned on and the clutch is engaged, but the clutch and
Brake relay 2R monitoring relay 2X is
Maintain the OFF state, turn off the monitoring relay 1X of the restart prevention relay 1R, operate the limit switch LS-3, turn off the detection relay 6X and the detection circuit auxiliary relay 3X, and suddenly stop the detection relay 1R. Relay 4X turns on, turning on detection circuit auxiliary relay 3X, making restart impossible.

(3-15) Malfunction of detection circuit auxiliary relay 3X (a) Cannot recover from seizure due to contact A When the push button is turned on and the limit switch LS-4 operates after the above-mentioned intermediate stroke of press operation,
Detection relay 5X turns on, and detection relay 6X turns on.
On the other hand, the detection circuit auxiliary relay 3X and the detection relay 4X are in the ON state, and when the limit switch LS-4 returns, the detection relay 5X is turned on.
OFF, limit switch LS-5 operates,
Monitoring relay 9X of limit switch LS-5
Limit switch LS-1 to turn off and prevent restart
is activated, and the restart prevention relay 1R is activated accordingly.
And its monitoring relay 1X is turned OFF, and the press suddenly stops and stops in front of the fixed position. Further, when the relays 1R and 1X are turned off, the detection relay 4X and the detection circuit auxiliary relay 3X are turned on, and the detection relay 6X is turned off, making it impossible to restart.

(b) B contact is ON and does not work When the push button is turned on, the clutch and brake relay 2R are turned on and the clutch is engaged, but the clutch and
Monitoring relay 2X of brake relay 2R is ON
Relay 1 for monitoring restart prevention relay 1R
X remains OFF and limit switch LS-
3 operates, turning off the detection relay 6X and the detection circuit auxiliary relay 3X, causing a sudden stop, and at the same time, the detection relay 4X turns on, making it impossible to restart.

(3-16) Malfunction of detection relay 4X (a) Cannot recover from seizure due to contact A When the push button is turned on and the limit switch LS-4 operates after the above-mentioned intermediate stroke of press operation,
Detection relay 5X turns ON, detection relay 6X and detection circuit auxiliary relay 3X turn OFF, while
Detection relay 4X maintains the ON state, and when limit switch LS-4 returns, detection relay 5X turns OFF and limit switch LS-4 returns.
5 operates, the monitoring relay 9X of the limit switch LS-5 turns OFF, the restart prevention limit switch LS-1 operates, and accordingly the restart prevention relay 1R and its monitoring relay 1X turn OFF.
The press turns OFF and suddenly stops before reaching its fixed position. Further, although the relays 1R and 1X are turned off, the detection relay 4X remains on, so the detection relay 6X is turned off and cannot be restarted.

(b) B contact does not operate in ON state In this case, it becomes impossible to drive.

(3-17) Malfunction of detection relay 5X (a) Seizure at contact A, unable to return When the push button is turned on and the limit switch LS-4 operates after the intermediate stroke of the press operation described above,
Detection relay 5X turns ON, detection relay 6X,
Detection circuit auxiliary relay 3X and detection relay 4X
OFF, limit switch LS-5 operates,
Monitoring relay 9X of limit switch LS-5
Limit switch LS-1 to turn off and prevent restart
is activated, and the restart prevention relay 1R is activated accordingly.
and its monitoring relay 1X is turned OFF, and the limit switch LS-2 for fixed position stop is activated.
The clutch and brake relay 2R are turned OFF and the press stops at the fixed position. Also, the operation of limit switch LS-2 turns off the monitoring relay 2X of the clutch and brake relay 2R.
Detection relay 6X turns on and limit switch LS
Even if -3 returns, since the detection relay 5X is in the ON state, the detection circuit auxiliary relay 3X and the detection relay 4X are turned OFF and cannot be restarted.

(b) Does not operate when the B contact is ON Even if the push button is turned ON and the limit switch LS-4 is activated after the above-mentioned intermediate steps of press operation, the detection relay 5X is in the OFF state, so the restart prevention limit switch LS-4 is activated. 1 operates, restart prevention relay 1R and its monitoring relay 1X are activated.
OFF, the detection relay 6X and the detection circuit auxiliary relay 3X are turned OFF, and the press suddenly stops and stops before the fixed position. Also, detection relay 4X is turned on by turning off restart prevention relay 1R and its monitoring relay 1X (held by limit switch LS-4).
However, the detection circuit auxiliary relay 3X turns ON, making it impossible to restart.

(3-18) Malfunction of detection relay 6X (a) Seizure at A contact, unable to return Turn on the push button, and after the above-mentioned mid-stroke of press operation, limit switch LS-4 operates and detection relay 5X turns on. Even if the detection relay 6X
Since it is in the ON state, the detection circuit auxiliary relay 3X and detection relay 4X turn OFF and suddenly stop. or,
Restart prevention relay 1R, its monitoring relay 1
X, clutch, brake relay 2R, its monitoring relay 2X, and limit switch LS-5 monitoring relay 9X are turned OFF, and detection relay 6 is turned OFF.
X turns ON, the detection circuit auxiliary relay 3X and the detection relay 4X turn OFF, making restart impossible, and the detection relay 5X turns ON.

(b) Does not operate when B contact is ON In this case, it becomes impossible to drive.

(3-19) Malfunction of operation preparation relay 7X In this case, it becomes impossible to drive.

(3-20) Malfunction of monitoring relay 8X of limit switch LS-1 (a) Cannot recover due to seizure at A contact In this case, operation cannot be prepared and operation becomes impossible.

(b) B contact is ON and does not operate When the push button is turned ON and the limit switch LS-4 is activated after the press operation is completed as described above, the detection relay 5X is turned ON, and the detection relay 6X is activated.
At the same time, the detection circuit auxiliary relay 3X and the detection relay 4X are turned OFF, making it impossible to restart.

(3-21) Malfunction of monitoring relay 9X of limit switch LS-5 (a) A contact burns out and cannot be recovered. Detection relay 6X, detection circuit auxiliary relay 3X and detection relay 4X are turned OFF and cannot be restarted ( b) B contact is ON and does not operate When the push button is turned on, the clutch, brake relay 2R, and its monitoring relay 2X are turned on, but the restart prevention relay 1R and monitoring relay 1X are not activated.
Since it is in the OFF state, the limit switch LS-3
operates to turn off the detection relay 6X and the detection circuit auxiliary relay 3X and suddenly stop, while the detection relay 4X maintains the ON state and turns on the detection circuit auxiliary relay 3X, making it impossible to restart.

[4] During overrun When the press is operated by turning on the push button and the press stops after passing the fixed position, detection relay 6X, detection circuit auxiliary relay 3X, detection relay 4X, restart prevention relay 1R, and limit switch are activated. LS-5
Monitoring relays 9X are turned ON. Then, the limit switch is activated by stopping the press from overrunning.
LS-3 operates, and detection relay 6X and detection circuit auxiliary relay 3X are turned OFF, while detection relay 4X is kept ON by limit switch LS-4. Furthermore, by turning off detection relay 6X and detection circuit auxiliary relay 3X, restart prevention relay 1R turns OFF, and detection circuit auxiliary relay 3X turns ON.
and cannot be restarted.

[5] At the time of emergency stop In this case, it is impossible to restart from that position, and the operation returns by turning the on/off switch to “off”, bringing it to the normal position, then turning it to “on”, and pressing the operation preparation button F. A reboot is possible.

[6] Switching the off/on switch When the off/on switch is turned on, inching, one stroke, and one safe stroke operation is possible, and when it is turned off, continuous operation is possible.

In the above operation explanation, the limit switch LS-4 constituting the detection means can be replaced with a timer T as shown in FIG. 3, and the same operation as described above can be performed.

FIG. 6 is a time chart showing the operation of limit switches LS-1 to LS-5.

(Effects of the Invention) Since the failure detection device of the present invention has the configuration as described in detail above, it is possible to easily connect and detect failures without particularly modifying the operating circuit of the press machine. That is, the emergency stop circuit of the operation circuit in the press machine is shut off every stroke by the detection circuit,
Energization can be controlled. If a failure occurs in the operation circuit of the press machine or the failure detection device connected to it, this will be detected and the emergency stop circuit will be cut off, causing the press to come to an emergency stop (sudden stop) and stop at a fixed position. Disables restart even if
Furthermore, it is possible to constantly check the performance of the brakes and at the same time monitor overruns to ensure safety.

[Brief explanation of drawings]

Fig. 1 is a circuit diagram showing one embodiment of the present failure detection device, Fig. 2 is a circuit diagram when a brake relay is separately provided, and Fig. 3 is a circuit diagram in which the limit switch LS-4 in Fig. 1 is used as a timer. The circuit diagram when replaced, Figure 4 is a side view showing the installation state of the cam and limit switches LS-3 and LS-4 that constitute the detection means, Figure 5 is a front view of the same, and Figure 6 is the limit switch LS-1. -A time chart showing the operation of LS-5. Fig. 7 is a perspective view of the failure detection device in a box. In the diagram, 1X to 10X...Relay, LS-3, LS
-4...Limit switch, A...Failure detection circuit, C...Ready for operation indicator light, D...Cam, E
...Off/on switch.

Claims (1)

[Scope of utility model registration request] A failure detection circuit made up of multiple relays, a ready-to-operate indicator light that turns off before top dead center and turns on when it stops in place if there is no abnormality, a cam that rotates due to press operation, and a cam around the cam. 1. A malfunction detection device for a press machine, characterized in that it comprises a detecting means consisting of a limit switch disposed therein, and an on/off switch that connects the detection circuit to an electric circuit of the press machine.