JPH11248094A - Control circuit for operation of machinery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an operation control circuit (safety circuit) for machinery whereby a high degree of safety is established. SOLUTION: A switch K11 is admitted to move to the On position interlocking with the On operation of a start switch P actuated by an operator etc., under the condition that a relay switch *K2 on a line E is in On condition and a solenoid coil B1 is fed with current. The switch K11 is attracted and held in the On position by a solenoid coil B2 on the condition that the switch K11 has moved to the On position interlocking with On operation of the start switch P. When the magnetic attracting force of the solenoid coil B2 goes out, the switch K11 is moved to the Off position. Thereby the machinery is started by the start switch, and emergency stop can be made with an emergency stop switch, and even if melting, deposition etc., occurs in electric contacts, the emergency stopping function can be maintained certainly, and further it is possible to hinder restarting in the case that the melting deposition etc., has occurred in the electric contacts of a safety circuit.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a machine operation control circuit (hereinafter, also referred to as a safety circuit) using an electric contact circuit.

[0002]

2. Description of the Related Art Conventionally, machinery (general machinery, industrial machinery,
This refers to any machinery that is started and stopped via electrical signals, such as transportation equipment and robots. Hereinafter, it is simply called a machine. ) Is activated, and when a failure or the like occurs in the machine (for example, an unsafe condition is satisfied), the machine operation control circuit (safety Circuit) has been proposed.

For example, ISO / TR12100-2 (E
N292-2) Safety of machinery = basic concept, design in general
Principles, Part 2: Technical Principles and Specifications, as described in Article 3.5｝
It is based on the safety principle and is called category 1 safety
There is a safety circuit included in the concept (Category 1 in Figure 6)
Column). This is a well-examined safety component
Operation as described in compulsory operation (positive
Mode) emergency stop switch DS and electromagnetic relay K
1 is provided. Then, when starting up,
Relay (electromagnetic coil) K1 energizes relay switch^*
K1 is magnetically attracted to turn it on and start from this state
Turn on the switch P to start the machine, while emergency stop
At times, the emergency stop switch DS is turned off,
When the magnetic relay K1 is de-energized, the relay switch ^*K1
It is turned off.

However, when the relay switch ^* K1 is contact-welded (contact welding may occur due to the generation of a spark when the switch is turned on), an emergency stop becomes impossible. However, there is a possibility that the machine will be started even if such an emergency stop function is impaired. That is, the category 1 does not have a function of checking the safety function, and the security is ensured by the reliability of each component.

[0005] Further, in order to achieve a level of safety that is one step higher than this, safety circuits included in a safety concept called category 2 have been proposed. This is configured to include a forced operation type emergency stop switch DS and electromagnetic relays K1 and K3, as shown in the category 2 column of FIG. That is, in the diagram shown in the column of category 2 (representing the normal initial state), when the start switch P is turned on, the electromagnetic relay K3 of the line B starts to be energized.
The relay switch on line A that works with this ^* K3 is O
FF → ON and the relay switch ^* K3 on line C (output line) is turned ON → OFF. Each of the relay switches ^* K3 is mechanically linked to each other, and any one of the relay switches ^*
When the ON / OFF state of K3 is switched, the ON / OFF state of all other relay switches ^* K3 is also switched.

Then, the electromagnetic relay (electromagnetic coil unit) K1
Since the energization of the relay switch is started, each of the relay switches ^* K1 (each of the relay switches ^* K1) is mechanically linked to each other, and any one of the relay switches ^* K1 unless the contacts are welded. ^{* When} K1 is switched ON / OFF, all other relay switches ^* K1 are also ON / O
ON / OFF of FF switching)
The state will be switched.

Specifically, a relay switch on line A
^* K1 is changed from OFF to ON, the relay switch on line B ^* K1 is changed from ON to OFF, and the relay switch on line C (output line) ^* K1 is changed from OFF to ON. And the relay switch on line B ^* K1
Is turned off, the electromagnetic relay K3 is de-energized, and the relay switch ^* K3 on the line A is turned ON → OFF.
At this time, the relay switch on line A ^* K1
Is ON, the energization of the electromagnetic relay K1 is continued,
Each relay switch ^* K1 will be self-held in said state.

The relay switch on line B ^* K1
Is turned off, and when the electromagnetic relay K3 is de-energized, the relay switch ^* K3 on the line C is turned from OFF to ON.
The relay switch that has already been turned on ^* K
In conjunction with 1, power supply to the machinery is started, and the machinery is started. At the time of an emergency stop, by turning off the emergency stop switch DS, the electromagnetic relay K1 is de-energized, and the relay switch on the line C is turned off.
^* K1 is forcibly turned off.

The relay switch on line C ^* K3
Is turned off, and the relay switch on line C ^* K
Since 1 is turned from OFF to ON, the relay switch on the line C ^* The relay switch that operates at the time of an emergency stop ^* because sparks are prevented from being generated at K1 and welding of the contacts is suppressed ^.
The function maintenance performance of K1 is enhanced. However,
Even with the safety relay according to Category 2 having the above configuration,
For example, when any one of the relay switches ^* K1 on the lines A to C is turned on at the time of start-up or the like, there is a fear that sparks may fly and that contact welding may occur. When the contact welding or the like occurs in any of the relay switch ^* K1 in a state where the relay switch ^* K1 on line C becomes ON, even if OFF the emergency stop switch DS, the relay on line C Since neither of the switches ^* K1 and ^* K3 can be turned off, there is a possibility that an emergency stop cannot be performed.
For this reason, the operation of the machinery cannot be stopped unless the main power supply (system power supply) is turned off, and the machine is started as soon as the main power is turned on without restarting the start switch P when restarting. There is a fear that he will do it.

In order to compensate for such a disadvantage of category 2, a safety circuit which is included in the category 3 safety concept with further enhanced safety has been proposed. This one is
As shown in the column of category 3 in FIG. 6, the function of the emergency stop switch of the forced operation type and the function of the electromagnetic relay K1 are doubled. That is, in the diagram shown in the column of category 3 (representing the normal initial state), the start switch P
Is turned on, the energization of the electromagnetic relay K3 of the line B is started.
^* K3 is turned from OFF to ON, and the relay switch on line C (output line) ^* K3 is turned from ON to OFF. In addition,
Each relay switch ^* K3 has the same configuration as described above,
They are mechanically linked to each other.

Then, an electromagnetic relay (electromagnetic coil unit) K
1, since power supply to K2 is started, each relay switch ^* K1, ^* K2 (each relay switch ^*
K1 has the same configuration as described above, and is mechanically linked to each other. Each relay switch ^* K2 has the same configuration. ) Is switched between ON and OFF states.

More specifically, a relay switch on line A
^* K1 is changed from OFF to ON, the relay switch on line B ^* K1 is changed from ON to OFF, and the relay switch on line C (output line) ^* K1 is changed from OFF to ON. Similarly, a relay switch on line D ^* K2
Is changed from OFF to ON, and the relay switch on line B ^*
K2 is turned ON → OFF, and the relay switch ^* K2 on line C (output line) is turned OFF → ON.

Then, a relay switch ^* K on the line B
When 1 or ^* K2 is turned off, the electromagnetic relay (electromagnetic coil unit) K3 is de-energized, and each relay switch ^* K3 on the lines A and D is turned from ON to OFF. Relay switch ^* K1, ^* K2 is ON
Therefore, energization of the electromagnetic relays K1 and K2 is continued,
Each of the relay switches ^* K1, ^* K2 is self-maintained in the above state.

The relay switch on line B^*K1
Or^*When K2 is turned off, the electromagnetic relay K3 is turned off.
When de-energized, the relay switch on line C^*K3 is
A relay that has been turned ON from OFF to ON and is already ON
switch^*K1,^*Combined with K2, power supply to the machine is opened
Is started and the machine is started. Ma
At the time of emergency stop, the emergency stop switch DS1 or D
By turning off S2, the electromagnetic relay K1 or K2 is turned off.
Relay switch on line C as non-energized ^*K1 or
Is to forcibly turn off K2.

Further, at the time of restarting, if one of the relay switches ^* K1 and ^* K2 on the line C is in the ON state and the contacts are welded, etc., the relay switch ^* K1 or ^* on the line B Since K2 is OFF,
Even if the start switch P is turned on, the electromagnetic relay K3 is not energized, so that the electromagnetic relay corresponding to the relay switch in which contact welding or the like does not occur is not energized.
Since the relay switch on the line C on the side where no contact welding or the like has occurred is not turned on, it is possible to create a safe state in which starting the machine is not permitted.

That is, as long as the relay switch ^* K1 and the relay switch ^* K2 are not welded together, the emergency stop function, that is, safety is ensured. In addition, turn off the relay switch ^* K3 on line C.
The relay switches on line C ^* K1, ^* K
2 is switched from OFF to ON, so that the occurrence of sparks at the relay switches ^* K1 and ^* K2 on the line C and the occurrence of contact welding and the like are suppressed, the functions of the relay switches ^* K1 and ^* K2 that operate during an emergency stop The maintenance performance has been enhanced.

However, even in the safety circuit according to Category 3 having the above configuration, when any one of the relay switches ^* K1 and ^* K2 of the lines A to D is turned on at the time of starting, for example, a spark is generated. There is a risk of flying, which may lead to contact welding. When both the relay switches ^* K1 and ^* K2 on the line C are turned on, there is a fear that both the relay switches ^* K1 and ^* K2 on any of the lines may be contact-welded. In such a case, even if the emergency stop switches DS1 and DS2 are turned off, the relay switches ^* K1, ^* K2, and ^* K3 on the line C cannot be turned off, so that the emergency stop cannot be performed. Cannot be avoided reliably. Then, it is said that the operation of the machinery cannot be stopped unless the main power is turned off, and that the machinery is started as soon as the main power is turned on without restarting the start switch P at the time of restart. It was impossible to avoid fears.

The present invention has been made in view of the above-mentioned conventional circumstances, and when a malfunction or the like occurs in machinery (when unsafe conditions are satisfied, etc.), contact welding or the like has occurred at the electrical contact. In addition, it is necessary to ensure that the operation of machinery can be stopped in an emergency, and that the machinery cannot be started until such a state where contact welding occurs is released (repair, etc.), thereby achieving a high level of safety. It is an object of the present invention to provide a machine operation control circuit (safety circuit) capable of achieving the following.

[0019]

According to the first aspect of the present invention, there is provided an operation control circuit for a machine, comprising an output line connected to the machine, the switch K11 being interlocked with a start switch P. ON / OF by electromagnetic relay K2
Relay switch in initial OFF state switched to F ^* K
2 and a line C connected in series with an initial ON-state relay switch ^* K3 that is turned ON / OFF by an electromagnetic relay K3, and a line connected to an emergency stop switch. The relay switch ^* K1 in the initial OFF state and the relay switch ^* K3 in the initial OFF state which are switched OFF are connected in parallel, and are connected to the line A connected to the electromagnetic relay K1 and the electromagnetic coil B2 and the emergency stop switch. A line D connected to the electromagnetic relay K2 while connecting the relay switch ^* K2 in the initial OFF state and the relay switch ^* K3 in the initial OFF state in parallel. a relay switch ^* K1 in the oN state, the relay switch ^* K2 of initial oN state, the in series connected, against the electromagnetic relay K3 And line B that is, initial ON
State relay switch ^* K2 is connected, electromagnetic coil B
1 connected to a line E, and each relay switch
^* K1 are mechanically linked to each other, by energizing and non-energization switching of the electromagnetic relay K1, when any one of relay switches ^* K1 is ON-OFF switching, all the other relay switch ^* K1 is ON, Each relay switch ^* K2 is mechanically linked to each other, and one of the relay switches ^* K2 is turned ON / OFF by switching the energization / de-energization of the electromagnetic relay K2.
When the switch is switched, all the other relay switches ^* K2 are switched ON / OFF, and the respective relay switches ^* K3 are mechanically linked to each other to form an electromagnetic relay K3.
When any one of the relay switches ^* K3 is turned ON / OFF by the energized / deenergized switching of all of the above, all the other relay switches ^* K3 are turned ON / OFF, and the machinery is started. Sometimes the line E
Under the condition that the upper relay switch ^* K2 is ON and the electromagnetic coil B1 is energized, the switch K11 is interlocked with the ON operation of the start switch P by the driver or the like.
Is configured to be permitted to move from the OFF position to the ON position, and the electromagnetic coil B2 is moved on the condition that the electromagnetic coil B2 moves to the ON position in conjunction with the ON operation of the start switch P by the driver or the like.
The switch K11 is allowed to be attracted and held at the ON position by the magnetic attraction force of the electromagnetic coil B.
The switch K11 is turned off by the disappearance of the magnetic attraction force of No. 2.
It is configured to be moved to a position.

With this configuration, the machine is started by the start switch, and when a trouble or the like occurs in the machine (for example, when an unsafe condition is satisfied), the operation of the machine is stopped by the emergency stop switch. The emergency stop function can be reliably maintained even if the contacts can be stopped and the electrical contacts (switches, etc.) in the safety circuit are welded, and the contacts are welded to the electrical contacts in the safety circuit. When such a situation occurs (for example, when repair or the like has not been performed), it is possible to reliably prevent restart.

Therefore, according to the present invention, it is possible to provide a safety circuit capable of achieving a category 4 safety concept that exceeds the conventional category 3 safety concept. That is, the safety circuit according to the present invention does not ensure the safety in expectation that the relay switch ^* K1 and the relay switch ^* K2 do not simultaneously perform the contact welding and the like as in category 3, but the contact welding and the like occur. By using the switch K11 in which the fear has been completely eliminated, even if other electric contacts (each switch) are welded at the same time, it is possible to ensure the safety without fail, and thereby to be more aggressive. A high level of safety can be achieved.

According to the second aspect of the present invention, the line D
The relay switch in the initial OFF state^*K1 is connected in series
To be configured. With such a configuration, the line D
Upper relay switch^*Re-race after turning K3 ON
Itch^*K1,^*Since K2 is turned on, on line D
Relay switch ^*When turning on K3, sparks fly
The advantage is that the risk of welding can be reduced because it can be suppressed.
Yes, safety can be further improved.

According to the third aspect of the present invention, the electromagnetic coil provided in the electromagnetic relay K1 is configured to function also as the electromagnetic coil B1. With such a configuration,
While achieving the safety concept of Category 4, the configuration can be simplified and the cost can be reduced.

[0024]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a diagram showing a configuration of a safety circuit (operation control circuit of machinery) according to an embodiment of the present invention. FIG. 2 is a cross-sectional view showing an example in which the safety circuit according to FIG. 1 is embodied.

Hereinafter, the safety circuit 1 according to the present embodiment shown in FIG. 1 will be described with reference to FIG. As shown in FIG. 1 (representing a normal initial state), the safety circuit 1 according to the present embodiment includes, on a line C (output line), a switch K11
ON and OF by the electromagnetic relay (electromagnetic coil part) K2
Relay switch in initial OFF state switched to F ^* K
2 and ON / O by electromagnetic relay (electromagnetic coil part) K3
FF switched relay switch in initial ON state ^* K
3 are interposed. Note that MS connected to the line C (output line) indicates machinery.

Then, the emergency stop switches DS1, DS2
The line A connected to is connected to an initial OFF which is switched ON / OFF by an electromagnetic relay (electromagnetic coil unit) K1.
The relay switch ^* K1 in the state and the relay switch ^* K3 in the initial OFF state are interposed in parallel and connected to the electromagnetic relay (electromagnetic coil unit) K1 and the electromagnetic coil B2.
The switch K11 is connected to the electromagnetic coil B2 itself.
There is no magnetic attraction that can be moved from the F position to the ON position, and it is necessary to hold the switch K11 that has been moved to the ON position and is in contact with the surface of the electromagnetic coil B2 in conjunction with the ON operation of the start switch P. It is configured with a relatively small capacity so that only a magnetic attraction force is generated. Alternatively, the switch K11 is turned off so that the switch K11 does not move from the OFF position to the ON position when a magnetic attractive force is generated in the electromagnetic coil B2.
The F position may be configured to be kept away from the electromagnetic coil B2 with a predetermined amount of clearance.

That is, for example, as shown in FIG. 2, when a magnetic attractive force is generated in the electromagnetic coil B2, the attracting iron piece b2 is automatically attracted and the shaft C is moved downward without permission. To prevent the contact K11 from being turned ON, the adsorbed iron piece b2 has a predetermined amount of clearance.
It is also possible to extend the shaft C away from the electromagnetic coil B2.

The line D connected to the emergency stop switches DS1 and DS2 and parallel to the line A
FF state relay switch ^* K1 is interposed,
A relay switch ^* K2 in an initial OFF state and a relay switch ^* K3 in an initial OFF state are interposed in parallel and connected to an electromagnetic relay (electromagnetic coil unit) K2. And
Line B includes a start switch, a relay switch ^* K1 in an initial ON state, and a relay switch ^* K in an initial ON state.
2 are interposed and connected to an electromagnetic relay (electromagnetic coil unit) K3.

The line E has a reset state in the initial ON state.
Switch^*K2 is interposed and connected to the electromagnetic coil B1
I have. In addition, each said relay switch^*K1 is a mutual machine
Electromagnetically unless contact welding is performed.
Relay (electromagnetic coil) K1 allows any one relay
ー switch^*When K1 is switched ON / OFF,
All relay switches^*K1 also switches ON / OFF
It is configured to be. Other relay switch ^*K2,
^*K3 has the same configuration.

By the way, the start switch P and the switch K1
The relationship with 1 is such that if the start switch P is turned on if it is normal, the switch K11 is moved from the OFF position to the ON position in conjunction with this. Specifically, for example, the relay switch ^* K2 on the line E is ON
, The start switch P and the switch K11 are interlocked via the magnetic attraction of the electromagnetic coil B1 energized by the main power supply (system power supply). Switch ^* K2 is OF
If F, the electromagnetic coil B1 is not energized, and the start switch P and the switch K11 are not linked.

That is, for example, as shown in FIG. 2, if a magnetic attraction force is normally generated in the electromagnetic coil B1, when the start switch P is turned ON, B1, b
1, shafts C and b2 are moved downward, and K11 is turned on
It is supposed to be. If the relay switch ^* K2 on the line E is OFF, the electromagnetic coil B
1 does not generate a magnetic attraction force,
Even if the N operation is performed, only b1 is moved downward via the arm (B1, shafts C and b2 do not move), and K11 is never turned ON.

The safety circuit 1 according to the present embodiment having the above-described configuration operates as follows. That is, when the start switch (for example, a push button switch) P is turned ON from the normal initial state, the switch K11 is turned ON (moved to the ON side) and the relay switches ^* K1, ^* K2 on the line B are operated. Is in the initial ON state, power is supplied to the electromagnetic relay (electromagnetic coil unit) K3.

When the electromagnetic relay K3 is energized, the line C
Relay switch on (output line) ^*K3 is ON → OF
F, while re-race on line A (and line D)
Itch^*Since K3 turns ON, the electromagnetic relay (electromagnetic coil
Power supply to K1 is permitted and the switch
Before holding K11 in the ON state by magnetic attraction
The energization of the electromagnetic coil B2 is also permitted.

Therefore, the electromagnetic relay (electromagnetic coil unit) K1
The ON / OFF state of each relay switch ^* K1 linked with the switch is switched, and the switch K11 is held in the ON state by the magnetic attraction of the electromagnetic coil B2. Specifically, a relay switch on line A ^* K1
Is changed from OFF to ON, and the relay switch on line D ^*
K1 is turned from OFF to ON.

At about the same time, since the relay switch ^* K3 on the line D has already been turned ON, energization to the electromagnetic relay (electromagnetic coil unit) K2 is started. Then, the ON / OFF state of each relay switch ^* K2 linked with the electromagnetic relay (electromagnetic coil unit) K2 is switched. Specifically, the relay switch ^* K2 on the line D is turned from OFF to ON, the relay switch ^* K2 on the line C (output line) is turned from OFF to ON, and the relay switch ^* K2 on the line B is turned from ON to OFF. Will be.

And a relay switch on line B^*K
1,^*K2 is turned off and the electromagnetic relay (electromagnetic coil)
K3 is de-energized, and each relay switch of line A and D
^*K3 is turned ON → OFF. At this time, lines A and D
Upper relay switch^*K1, ^*Is K2 already ON?
The power supply to the electromagnetic relays K1 and K2 is continued
switch^*K1,^*K2 is held in the same state as above
Will be.

The relay switch on line B ^* K2
Is turned off, and the electromagnetic relay K3 is de-energized, the relay switch ^* K3 on the line C is turned on, so that the switch K11 and the relay switch ^* K2 already held in the ON state are combined with MS (machinery ) Is started, and the machines are started. And
At emergency stop, emergency stop switch DS1 or DS2
Is turned off, the electromagnetic relay K1 or the electromagnetic relay K2 (electromagnetic coil B2) is de-energized, and the switch K11 or the relay switch ^* K2 of the line C is forcibly turned off.
Will be able to do that.

As described above, the basic safety that "the machine can be started by the start switch and the machine operation can be stopped by the emergency stop switch when a trouble or the like occurs in the machine (unsafe condition is satisfied, etc.)" Will be achieved. Next, a case where welding or the like occurs at the electric contact in the safety circuit 1 according to the present embodiment will be described.

In this embodiment, when starting up,
And a relay switch on line C ^*When K2 is OFF
Switch K11 of line C is turned on by manual operation
And the relay switch on line C^*K2
Is ON, the relay switch on line E^*K2 is O
This is an abnormal time when the switch K11 is turned on.
Is not turned on, the switch K11 is turned on.
Sparks do not fly when the switch K11
There is no possibility that contact welding or the like may occur.

When contact welding or the like occurs in relay switch ^* K2 (other contacts are assumed to be normal) In the safety circuit 1 according to the present embodiment, a line is connected to any one of the relay switches ^* K2 at the time of starting operation or the like. If the emergency stop switch DS1 is turned off, the electromagnetic coil B2 is de-energized even if contact welding or the like occurs while the relay switch on K ^* 2 is turned on. It can be turned off, and the emergency stop function can be surely maintained.

That is, the relay switch ^* K on the line C
When contact welding or the like occurs in a state where 2 is ON, since the relay switch ^* K2 on the line E is OFF, the energization to the electromagnetic coil B1 is stopped.
This is because, when the emergency stop switch DS1 is turned off and the electromagnetic coil B2 is de-energized, the switch K11 is not interlocked with the start switch P and moves to the OFF state without any restriction.

[0042] In addition, upon restart, if the contact welding or the like occurs in a state in which the relay switch ^* K2 on the line C is turned ON, because the relay switch ^* K2 on line E is in the OFF, electromagnetic Since the coil B1 is non-energized and the switch K11 and the start switch P are not interlocked, no matter how the start switch P is turned on, the switch K11
Is not turned on, so the relay switch ^* K2
When contact welding etc. has occurred while
A situation in which the machine is started can be reliably eliminated.

Even if contact welding or the like occurs while the relay switch ^* K2 on the line C is ON, the switch K11 is definitely OFF. Even if no operation is performed, it is possible to surely eliminate the fear that the machines will be activated as soon as the main power is turned on. Incidentally, in any of the relay switch ^* K2, the relay switch ^* K2 on the line C is O
If contact welding occurs in the state of FF, the output line is cut off and the machine will not start, so
Safety is ensured.

When contact welding or the like occurs on relay switch ^* K1 (other contacts are assumed to be normal) For example, when contact welding or the like occurs with each relay switch ^* K1 turned ON, an emergency stop is performed. Switch DS1
Is turned off, the electromagnetic coil B2 is de-energized.
The switch K11 can be reliably turned off, so that the emergency stop function can be reliably maintained.

Then, the relay switch ^* K on the line A
As described above, even if contact welding or the like occurs in the state in which the switch K11 is turned on and the electromagnetic coil B2 is energized from the beginning at the time of restart, the electromagnetic coil B2 is connected to the switch K11.
There is no magnetic attraction force for moving the switch from the OFF position to the ON position, and only the magnetic attraction force necessary to hold the switch K11 that moves to the ON position in conjunction with the ON operation of the start switch P is generated. It is possible to reliably eliminate the fear that the machines will be activated as soon as the power is turned on.

Also, the relay switch ^* K1 on the line A
Is turned on, contact welding or the like occurs. Even if the electromagnetic coil B2 is energized from the beginning at the time of restart, the relay switch ^* K1 on the line B is off, so the electromagnetic relay K3 extends Means that the electromagnetic relay K2 is de-energized and the relay switch ^* K2 on the line C remains OFF. Therefore, even if the switch K11 moves to the ON position in conjunction with the ON operation of the start switch P, It is possible to surely eliminate the fear of starting.

When contact welding or the like occurs when each relay switch ^* K1 is OFF, the electromagnetic relay K
Since no power is supplied to the electromagnetic coil 2 and the electromagnetic coil B2, the machine does not start, so that safety is ensured. Relay switch ^{* When} contact welding etc. occurs on K1 and ^* K2 (other contacts are assumed to be normal) During start-up operation, etc., relay switch on line C ^*
K2, each relay switch ^{* Even} if contact welding occurs while K1 is on, the emergency stop switch DS1 is turned off.
Then, since the electromagnetic coil B2 is always de-energized, the switch K is not likely to cause contact welding or the like after starting.
Since 11 is reliably turned off, the emergency stop function can be reliably maintained.

At the time of restart, the relay switch ^* K2 on the line C and the relay switch ^* K1 on the lines A and D
Even if contact welding or the like occurs while the switch is ON, since the relay switch ^* K2 on the line E is OFF, the electromagnetic coil B1 is not energized, and the switch K11 and the start switch P are linked. No matter how the start switch P is turned on, the switch K11 is not turned on (even if each relay switch ^* K1 is turned on, because the magnetic attraction of the electromagnetic coil B2 is small). That is, it is possible to reliably eliminate a situation in which the machine is started.

For example, if the relay switch ^* K2 on the line C and the relay switch ^* K1 on the lines A and D are O
Even if contact welding or the like has occurred in the state of N, the switch K11 is surely in the OFF state. It is possible to eliminate the fear that the program will be activated.

The relay switch on line C ^* K2
If the contact is welded while the switch is OFF, the output line is cut off and the machine will not start, regardless of the state of the relay switch ^* K1, so safety is ensured. You. Also relay switch ^* K3 on if the line C the relay switch ^* K3 to contact welding or the like has occurred in contact welding or the like in the ON state, do not participate in the emergency stop, there is no effect on the emergency stop function.

Upon restart, the relay switch on line C
^{* Even} if contact welding occurs while K3 is ON, relay switches on other lines ^* K3 are OFF, so relay switches on line C ^* K2 are O
Since it is not set to N, it is possible to reliably eliminate a situation in which the machine is started. Also, at the time of restarting, even if contact welding or the like occurs while the relay switch ^* K3 on the line C is turned off, the output line is cut off, and the situation that the machine is started is surely prevented. Can be eliminated.

At the time of restart, even if contact welding or the like occurs while the relay switch ^* K2 and the relay switch ^* K3 on the line C are turned on, the relay switch ^* K2 on the line E is turned off. The electromagnetic coil B
No. 1 is not energized and the switch K11 and the start switch P are not linked, so that no matter how the start switch P is turned on, the switch K11 is not turned on (each relay switch ^* K1 is turned on) ^. This is because the magnetic attraction of the electromagnetic coil B2 is small), so that a situation in which the machine is started without permission can be reliably eliminated.

When contact welding or the like occurs on the start switch P Even if contact welding or the like occurs while the start switch P is ON during a start operation or the like, the relay switch ^* K2 Is ON, line E
Since the upper relay switch ^* K2 is turned off, the electromagnetic coil B1 is de-energized, and the emergency stop switch DS1 is turned off.
F, if the electromagnetic coil B2 is de-energized, the switch K1 is free to move due to the de-energization of the electromagnetic coil B1.
1 is reliably turned off (for example, B shown in FIG. 2)
Thus, the emergency stop function can be reliably maintained.

At the same time, the relay switch ^* K2 on the line C and the relay switch ^* K1 on the lines A and D are
Even if the contact is welded in the N state, the same result as described above is obtained.
At the same time, the relay switch ^* K2 on line C is
If contact welding occurs in the FF state, a relay switch
^* Regardless of the state of K1, the machine does not start, so safety is ensured.

At the time of restart, the start switch P is turned on.
Even if contact welding or the like has occurred in the state of, the switch K11 has been returned to the OFF position by the previous operation stop because the electromagnetic coil B1 was de-energized during the previous operation. Even if the coil B1 is energized,
The start switch P is in the ON position, and the switch K11 is OFF.
Since the switch is in the position, the switch K11 is not set to the ON position (see FIG. 2). That is, in FIG. 2, when the start switch P is in the ON position and the switch K11 is in the OFF position, the electromagnetic coil B1 is moved and cannot be attracted to the attracting iron piece b1 even if the power supply to the electromagnetic coil B1 is started. The magnetic attraction of the electromagnetic coil B1 is set.

Therefore, since the machine is not started without permission, safety is ensured. At the same time, the relay switch on line C ^* K2, each relay switch ^*
Even if the contact is welded while K1 is in the ON state, the same results. At the same time, a relay switch on line C ^* K2
If the contact is welded in the OFF state, the output line is cut off and the machine does not start, so that safety is ensured.

As described above, according to the machine operation control circuit (safety circuit) according to the present embodiment, the machine is started by the start switch, and when a trouble or the like occurs in the machine (for example, it is not safe). When conditions are met, etc.), the operation of the machine can be stopped by the emergency stop switch, and even if the electrical contacts (switches, etc.) in the safety circuit are welded, the emergency stop function is ensured. Can be maintained, and when contact welding or the like has occurred at the electrical contact in the safety circuit (when repair or the like has not been performed), it is possible to reliably prevent restart.

Therefore, it is possible to provide a safety circuit capable of achieving a category 4 safety concept that exceeds the conventional category 3 safety concept. That is, the safety circuit according to the present embodiment does not guarantee the safety in expectation that the relay switch ^* K1 and the relay switch ^* K2 do not simultaneously perform the contact welding and the like as in the category 3, but the contact welding and the like are not performed. Switch K1 completely eliminates the fear
By using 1, even other electrical contacts (each switch)
However, even if the contacts are welded at the same time, the safety can be reliably ensured, so that a higher level of safety can be more positively achieved.

Here, a series of operations (mainly at the time of normal startup) of the specific example shown in FIG. 2 will be briefly described. For other operations, refer to the contents described above. i) First, the driver (operator) turns on the start button P
Manipulate. As a result, the contact P is turned ON.

Ii) If there is no welding or the like on the relay switch ^* K2, the electromagnetic coil B1 is energized, and the attracted iron piece b1 is attracted to the electromagnetic coil B1. Meanwhile, relay switch ^* K2
If there is welding or the like, since the electromagnetic coil B1 is not energized, the attracted iron piece b1 is not attracted to the electromagnetic coil B1. That is, activation is waited until the contact welding of the relay switch ^* K2 is repaired.

Iii) When the attracting iron piece b1 is attracted to the electromagnetic coil B1, when the start button P moves downward, the shaft C also moves downward in conjunction with the movement. iv) Then, the switch K11 is turned ON via the one-sided member fixed to the shaft C. v) At the same time, the attracted iron piece b2 fixed to the shaft C comes into contact with the electromagnetic coil B2.

Vi) When the electromagnetic coil B2 is energized, the attracting iron piece b2 and thus the switch K11 are held by the electromagnetic attraction force. vii) After that, the relay switch ^* K2 on line C is turned on
(Therefore, no spark is generated at the switch K11), and then the relay switch ^* K3 on the line C is turned on ^.
As a result, power is supplied to the machinery.

The emergency stop switches DS1,
The DS2 may be a push button type operated by a driver or the like, or automatically turned off by a danger signal (a human detection signal, a door open switch signal input, etc.) from a safety monitoring system or the like. It may be. In the above embodiment, the emergency stop switch DS
1 and DS2 are connected in series, but the present invention is not limited to this, and they may be connected in parallel as shown in FIG.
Even when connected in parallel, the same operation and effect as described above can be obtained. Then, FIG. 1 (or FIG. 4 described later)
When the emergency stop switches DS1 and DS2 are connected in series as described above, one of the emergency stop switches can be omitted.

As shown in FIG. 4, the relay switch ^* K1 on the line D can be omitted. However, if the relay switch is configured as shown in FIG. 1, the relay switch ^* K3 on the line D is turned ON, and then the relay switch ^* K1,
^{* Since} K2 is turned on, the relay switch on line D
^{* Since} sparks can be suppressed when K3 is turned on, there is an advantage that the fear of welding can be reduced, and safety can be further improved.

Further, in the above embodiment, the electromagnetic relay K1
Although the electromagnetic coil portion and the electromagnetic coil B2 have been described as being separate from each other, the electromagnetic coil portion of the electromagnetic relay K1 may be used (shared) {used (layout)} as the electromagnetic coil B2. .

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an operation control circuit (safety circuit) for machinery according to a first embodiment of the present invention.

FIG. 2 is a schematic diagram (cross-sectional view) showing a specific configuration example of a machine operation control circuit (safety circuit) in the embodiment.

FIG. 3 is a diagram showing another configuration example of an operation control circuit (safety circuit) for machinery (an example in which emergency stop switches are connected in parallel).

FIG. 4 is a diagram showing another configuration example of the operation control circuit (safety circuit) of the machinery (an example in which the relay switch ^* K1 on the line D is omitted).

FIG. 5 is a diagram showing another configuration example of the operation control circuit (safety circuit) of the machinery (an example in which the electromagnetic coil B2 is also used as the electromagnetic relay K1).

FIG. 6 is a diagram for explaining a conventional safety category.

[Explanation of symbols]

1 Machine operation control circuit (safety circuit) A to D line (electrical wiring) B1 Electromagnetic coil B2 Electromagnetic coil DS1, DS2 Emergency stop switch (door switch, etc.) K11 Switch K1 to K3 Electromagnetic relay (electromagnetic coil section) ^* K1 ~ ^* K3 Electromagnetic relay (relay switch part) MS Machinery P Start switch (start button)

Claims (3)

[Claims] 1. An output line connected to machinery,
An initial OFF which is turned ON / OFF by a switch K11 linked with the start switch P and an electromagnetic relay K2.
A line C connected in series with a relay switch ^* K2 in the initial state and a relay switch ^* K3 in the initial ON state which is turned ON / OFF by the electromagnetic relay K3, and a line connected to the emergency stop switch, Initial OFF that is switched ON / OFF by relay K1
While the relay switch ^* K1 in the initial state and the relay switch ^* K3 in the initial OFF state are connected in parallel, the electromagnetic relay K
1 and a line A connected to the electromagnetic coil B2, and a line connected to the emergency stop switch.
The line D connected to the electromagnetic relay K2, the start switch P, and the relay switch ^* K in the initial ON state are connected in parallel with the relay switch ^* K2 in the FF state and the relay switch ^* K3 in the initial OFF state.
1 and the relay switch ^* K2 in the initial ON state are connected in series, and the line B connected to the electromagnetic relay K3 and the line connected to the relay switch ^* K2 in the initial ON state and connected to the electromagnetic coil B1 And each of the relay switches ^* K1 is mechanically linked to each other. When one of the relay switches ^* K1 is turned on / off by switching the energization / de-energization of the electromagnetic relay K1, the other relay switches ^* K1 All relay switches ^* K1 is ON / OFF
Each of the relay switches ^* K2 is mechanically linked to each other, and when one of the relay switches ^* K2 is turned on / off by switching on / off of the electromagnetic relay K2, the other switches are turned off. All relay switches ^* K2 is ON / OFF
Each of the relay switches ^* K3 is mechanically linked to each other, and when one of the relay switches ^* K3 is turned on / off by switching the electromagnetic relay K3 between energized and de-energized, the other switches are switched. All relay switches ^* K3 is ON / OFF
Is a switching Configurations and when to start the machinery, the relay switches on the line E ^*
On condition that K2 is ON and the electromagnetic coil B1 is energized, the start switch P is turned ON by the driver or the like.
In conjunction with the operation, the switch K11 is turned on from the OFF position.
Position is permitted to move to the position.
The switch K11 is allowed to be attracted and held at the ON position by the magnetic attraction of the electromagnetic coil B2 on condition that the switch K11 is moved to the N position.
11. An operation control circuit for machinery, wherein 11 is configured to be moved to an OFF position. 2. The machine operation control circuit according to claim 1, wherein a relay switch ^* K1 in an initial OFF state is connected in series to said line D. 3. The machine operation control circuit according to claim 1, wherein the electromagnetic coil provided in the electromagnetic relay K1 is configured to function also as the electromagnetic coil B1.