JPH04401Y2 - - Google Patents

Description

[Detailed description of the invention] Industrial application field This invention is an emergency system in which a power line that supplies power from an AC power source to driven equipment such as NC machine tools and robots is provided on a separate line from this power line. The present invention relates to a power supply cutoff control device that cuts off power supply via a relay by operating a stop switch.

BACKGROUND TECHNOLOGY When an abnormal condition occurs in a controlled device such as an NC machine tool or a robot, such as hand overtravel or hand breakage, it is necessary to immediately stop power supply to the controlled device. In such cases, it is recommended to extend the power line that supplies power to the controlled equipment to a location close to the operator, insert an emergency stop switch directly into this power line, and cut off the power supply by turning off the switch. This is desirable in order to ensure a high level of However, since the power supply line for the controlled equipment is an AC line, it is necessary to extend it to the operator's side as described above.
It mixes with lines and reduces reliability.

For this reason, conventionally, for example, as shown in Figure 2,
A series circuit consisting of a driving DC power source 4, an emergency stop switch 5, and an emergency stop detection relay 6 is inserted into a line 3 separate from the power line 2 of the AC power source 1, and incorporated into a portable operating unit for the operator, etc. A make contact 6m of an emergency stop detection relay 6 is connected to the power line 2, and AC power is supplied to the controlled device 7 via the make contact 6m. Emergency stop switch 5
is normally in an on state, but is turned off when an emergency situation occurs, and the power supply line 2 is cut off by breaking the make contact.

By the way, since the make contact 6m is inserted into the AC power line and is turned on and off relatively often, it often gets welded and remains in the on state. If the make contact 6m is welded, it becomes impossible to cut off the power line 2 in an emergency, as is clear from the configuration shown in FIG. 2a.

Therefore, in order to prevent such malfunctions due to welding, a structure such as that seen in Japanese Patent Application No. 89388/1983 has been proposed. As shown in Figure 3b, this is the emergency stop detection relay 6 on another line 3.
The auxiliary relay 10 is connected in parallel with the AC power supply 1, and the series circuit of the welding detection relay 11 and the break contact 6b of the emergency stop detection relay 6 is connected in parallel with the AC power supply 1 as shown in FIG. line 2,
A monitoring line 14 separate from the separate line 3 is provided,
The break contact 10b of the auxiliary relay 10 and the break contact 11b of the welding detection relay 11 are connected in series to this monitoring line 14, and when both contacts 10b and 11b are turned on by the controller 12, a monitoring signal 12a is sent to the controlled device 13. Switch 13 inside
It controls the That is, when the emergency stop switch 5 is turned off in an emergency, if the emergency stop detection relay 6 operates normally, its make contact 6m
is closed, and the power line 2 is cut off. On the other hand, if the make contact 6m of the emergency stop detection relay 6 remains on due to welding, its break contact 6b also remains off, and the welding detection relay 11 remains off and its break contact 11
b remains on. In addition, auxiliary relay 10
is turned off by turning off the emergency stop switch 5, and its break contact 10b is turned on, so the controller 12 turns off the switch 13 in response to the supervisory signal 12a. Therefore, even if the make contact 6m remains closed, power supply to the controlled device 7 is stopped.

However, as shown in Figure 3, the controller 1
2 detects welding of the emergency stop detection relay 6, and the controller 12 turns off the switch 13 to stop the power supply in an emergency.Since the controller 12 is interposed in between, the emergency stop switch 5 is turned on. There is a non-negligible lag time between when the power supply actually stops, and
Furthermore, if the controller 12 malfunctions, the power supply cannot be stopped, resulting in reliability problems.

Problems to be Solved by the Invention The present invention is an improvement over such conventional problems, and its purpose is to be able to quickly cut off the power line 2 when the emergency stop switch 5 is turned off;
Another object of the present invention is to provide a highly reliable power supply cutoff control device.

Means for Solving the Problems In order to solve the above problems, the present invention provides an emergency stop switch in which the power line that supplies power from the AC power source to the driven equipment is provided on a separate line from the power line. In a power supply cutoff control device that is configured to cut off power via a relay by operation, a parallel circuit of an emergency stop detection relay and an auxiliary relay is connected in series with the drive DC power source of the separate line, and a parallel circuit with the emergency stop switch. The make contact of the emergency stop detection relay is connected in series to the power supply line, and the make contact and the AC
A welding detection relay and a break contact of the auxiliary relay are connected in parallel to a power source, and the welding auxiliary is connected between one end of a series circuit of the welding detection relay and the break contact of the auxiliary relay and the driven device. Connect the break contacts of the relay.

Operation When the emergency stop switch is turned off, if the emergency stop detection relay is normal, the make contact of the emergency stop detection relay inserted in series with the power supply line is turned off and the power supply line is immediately cut off. Also, when the emergency stop detection relay is welded, its make contact remains on, but since the auxiliary relay is turned off, its break contact is turned on, and the welding detection relay 1
1 turns on. As a result, welding detection relay 11
The break contact is turned off and the power line 2 is immediately cut off.

Embodiment FIG. 1 is an electrical circuit diagram of an embodiment of the present invention.
Figure a shows a power line system, Figure b shows a separate line system built into, for example, a portable operating unit, and Figure c shows a monitoring line system.

As shown in Figure a, the power line system includes an AC power source 1, a power line 2 that transmits power from this to the controlled device 7, and a make contact 6 m of an emergency stop detection relay 6 inserted into the power line 2. and a series circuit consisting of the make contact 6m, the break contact 10b of the auxiliary relay 10 inserted in series with the AC power supply 1, and the welding detection relay 11, and the power supply between one end of this series circuit and the controlled device 7. Break contact 1 of welding detection relay 11 inserted into line 2
1b1.

In addition, the separate line 3 system has a starting DC power supply 4,
Emergency stop switch 5 inserted into another line 3
and a parallel circuit of an emergency stop detection relay 6 and an auxiliary relay 10 inserted in series with the emergency stop switch 5.

Furthermore, a break contact 11b2 of the welding detection relay 11 is inserted into the monitoring line 14 system, and when the controller 12 detects that the break contact 11b2 is turned off, it generates an alarm signal 12b indicating that welding has occurred, and as shown in the figure. Turn on lamps, etc. that do not work.

The operation of this embodiment will be explained below.

1 When the power supply is being performed normally When no emergency situation has occurred and the emergency stop switch 5 is on, the emergency stop detection relay 6 is on and its make contact 6m is on. .
Further, since the auxiliary relay 10 is also on, its break contact 10b is off, and since no current flows through the welding detection relay 11, its break contact 11b1 is on. Therefore, make contact 6
Since both m and break 11b1 are in the on state,
Power is supplied from an AC power source 1 to a controlled device 7 via a power line 2 . In this case, since the break contact 11b2 is on, the alarm signal 1
2b is not generated.

2 When there is no welding in an emergency If the emergency stop switch 5 is turned off in an emergency,
Emergency stop detection relay 6 turns off, and power line 2
is cut off, the power supply immediately stops.
At this time, the break contact 11b2 remains on, so the alarm signal 12b is not generated.

3 If there is welding in an emergency If the emergency stop switch 5 is turned off in an emergency,
Emergency stop detection relay 6 tries to turn off, but
Due to welding, the make contact 6m does not turn off and remains on. However, when the auxiliary relay 10 is turned off, its break contact 10b is turned on, and the make contact 6m welded to this break contact 10b
Current flows from the AC power supply 1 to the welding detection relay 11 through the break contacts 11b1, 11b.
2 turns off. By turning off the break contact 11b1, the power line 2 is cut off, and the power supply is immediately stopped. Furthermore, when the break contact 11b2 is turned off, the controller 12 issues an alarm signal 12.

As can be seen from the above explanation, welding detection relay 1
When welding is detected at 1, the break contact 11
Since the power line 2 is directly cut off by b1, the power supply can be stopped immediately after the emergency stop switch 5 is turned off. In addition, the welding detection relay 11 is turned on only when welding occurs.
Under normal conditions, it does not turn on or off, and the current that flows when the break contact 10b is on is a sufficiently smaller value than the current that flows through the power supply line 2. Therefore, compared to the emergency stop detection relay 6, the welding detection relay 1
1 and the auxiliary relay 10 are extremely unlikely to weld together, making it possible to improve the reliability of the circuit.

Effects of the Invention As explained above, according to the present invention, even if the emergency stop detection relay 6 is welded, the break contact 11b1 of the welding detection relay 11 immediately shuts off the power line 2 when the emergency stop switch 5 is turned off. and the power line 2 can be directly cut off by the relay without stopping the power supply via the controller 12 as in the conventional case.
The welding detection relay 11 turns on only when welding occurs, and does not turn on or off under normal conditions, so the possibility of welding is extremely small compared to the emergency stop detection relay 6, thereby increasing the reliability of operation. becomes possible.

[Brief explanation of the drawing]

Fig. 1 is an electrical circuit diagram of an embodiment of the present invention, in which Fig. 1a shows a power supply line system, Fig. 1b shows a separate line system built into, for example, a portable operating unit, and Fig. 1c shows a monitoring line system. 2 and 3 are electrical circuit diagrams of the conventional device. 1 is AC power, 2 is power line, 3 is another line,
4 is a DC power supply for driving, 5 is an emergency stop switch, 6
is the emergency stop detection relay, 6m is its make contact, 6b is its break contact, 7 is the controlled device,
10 is an auxiliary relay, 10b is its break contact,
11 is a welding detection relay, 11b is its break contact, 12 is a controller, 12b is an alarm signal,
14 is a monitoring line.

Claims (1)

[Scope of utility model registration request] In the power supply cutoff control device, a power supply line that supplies power from an AC power source to a driven device is cut off via a relay by operating an emergency stop switch provided on a line separate from the power supply line. A parallel circuit of an emergency stop detection relay and an auxiliary relay and a series circuit of the emergency stop switch are connected in series to the DC power supply for driving the line, and a make contact of the emergency stop detection relay is connected in series to the power supply line. and connect a welding detection relay and a break contact of the auxiliary relay in parallel to the make contact and the AC power source, and one end of a series circuit of the welding detection relay and the break contact of the auxiliary relay. A power supply cutoff control device characterized in that a break contact of the welding auxiliary relay is connected between the driven device and the welding auxiliary relay.