JP2001336694A - Interlock device for safety fence door - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an interlock device for a safety fence door capable of preventing wrong-operation by a third person. SOLUTION: This interlock device for a safety fence door is characterized by having a handle provided in the safety rack door, a lock mechanism locking a position of the handle when the safety rack door is placed in an opened or closed condition, an unlock mechanism unlocking the lock, a door opening detection means detecting the opened condition of the safety fence door, a door closing detection means detecting the closed condition of the safety fence door, and an electric circuit outputting a signal making operation capable to a machine tool or the like only when a detected signal of the door closing detection means is turned on and a detected signal of the door opening detection means is turned off.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a safety device for restricting opening and closing of a door used for a safety fence for preventing a machine tool or the like from entering a dangerous area.

[0002]

2. Description of the Related Art Conventionally, a safety plug system has been adopted as an interlock device used for a door of a safety fence or the like. Representative examples are shown in FIGS.

In FIG. 5, reference numeral 3 denotes a press machine, and 2 denotes a leveler feeder for supplying a material to the press machine. A safety fence 4 is provided in the danger area of the leveler feeder 2. The safety fence 4 is provided with a safety fence door 5 so that the safety fence 4 can enter a danger area for maintenance and adjustment. The safety fence door 5 is provided with an interlock device 1 for the safety fence door that regulates the operation of the leveler feeder 2 and the press machine 3 according to the open / close state of the safety fence door 5.

FIG. 6 is a detailed view of a main part of the interlock device 1 of the conventional safety fence door 5. The receptacle 52 is provided on the safety fence 4 side. Contact point 52 of receptacle 52
a and 52b are connected to the interlock circuit of the leveler feeder 2. Interlocks 52a, 52b
Can be released by short-circuiting. On the other hand, plug 53
Are connected to the safety fence door 5 by a chain 54. The length of the chain 54 is set to a length that regulates the opening and closing of the safety fence door 5 so that a human cannot enter.

When operating the leveler feeder 2, the plug 53 is inserted into the receptacle 52. Then, the contacts 52a and 52b are short-circuited and the interlock is released. (FIG. 6 (A))

On the other hand, when entering the danger area for maintenance and adjustment of the leveler feeder 2, the plug 53 is pulled out (FIG. 6).
(B)), the safety fence door 5 is opened. Then, the contacts 52a,
The electrical connection of 52b is released, and the leveler feeder 2 cannot be operated by the interlock circuit.

[0007]

However, in the conventional safety plug type interlock device, a conductor is connected to a contact of a receptacle, and a machine tool or the like can be operated with a short circuit and a door openable and closable. Intentional remodeling can be facilitated. Also, even if the modification has not been performed, an accident such as operation of a machine by inserting a plug into a receptacle and not operating the machine may occur, without a third party noticing that a person has entered the dangerous area.

[0008] Therefore, an object of the present invention is to ensure the safety of a person who has entered a dangerous area by making it impossible to easily modify the apparatus and preventing an erroneous operation by a third party. An object of the present invention is to provide a safety fence door interlock device.

[0009]

According to a first aspect of the present invention, there is provided an interlocking device for a safety fence door provided on a safety fence for preventing a machine tool or the like from entering a danger zone. The open / closed state of the safety fence door is maintained by locking the handle that operates and counteracts when the safety fence door is opened and closed and the handle position when the safety fence door is open or closed. Locking mechanism,
A lock release mechanism for releasing the lock, a door open detection means for detecting an open state of the safety fence door, a door close detection means for detecting a closed state of the safety fence door, and a detection signal of the door close detection means Is ON, and outputs a signal operable to a machine tool or the like only when the detection signal of the door open detection means is OFF, and the detection signal of the door close detection means is OFF or the door open detection means And an electric circuit for outputting a signal indicating that the operation cannot be performed to a machine tool or the like when the detection signal is ON.

According to the first aspect of the present invention, the safety fence door is provided with a handle that operates and reacts when opened and closed, and the handle is locked when the door is open or closed. At this time, the open or closed state of the safety fence door is maintained. Further, a lock release mechanism is provided. Therefore, when a maintenance worker such as a machine tool enters the danger area and performs work, by maintaining the lock release mechanism by the maintenance worker himself, an accident due to erroneous operation by a third party can be prevented. .

On the other hand, the safety fence door is provided with door open detection means for detecting the open state of the safety fence door, and door close detection means for detecting the closed state of the safety fence door. Only when the detection signal is ON and the detection signal of the door open detecting means is OFF, the machine tool or the like can be operated. Further, when the detection signal of the door closing detecting means is OFF or the detection signal of the door opening detecting means is ON, the machine tool or the like cannot be operated. That is, the open / closed state of the safety fence door is detected by the double detection means, and particularly, the open state of the door is locked and held. As a result, the safety of the maintenance worker who has entered the dangerous area can be ensured, modification can be prevented, and safety against equipment failure can be improved.

According to a second aspect of the present invention, the electric circuit includes a door opening / closing confirmation / restart prevention storage circuit, and the door opening / closing confirmation / restart prevention circuit is configured such that the detection signal of the door closing detection means is OFF.
And when the detection signal of the door open detection means is ON, the set state is established, and the detection signal of the door close detection means is ON.
The safety fence door interlock device according to claim 1, wherein when the state is switched from "OFF" to "OFF", the state is reset by a rising differentiation circuit.

According to the second aspect of the present invention, the electric circuit is provided with a door open / close confirmation / restart prevention storage circuit. The door open / close confirmation / restart prevention storage circuit stores the detection signal of the door close detection means from ON to O
When switched to FF, it is reset by the rising differentiation circuit. The detection signal of the door closing detection means is O
When the FF is set and the detection signal of the door open detection means is ON, the set state is set.

Here, if the detection signal of the door-close detection means is OFF and the detection signal of the door-open detection means is OFF due to intentional modification or the like, the safety fence door can be opened. I do. (At this time, the handle is not locked.) At that time, when the worker enters the danger area and the third person closes the safety fence door, that is, when the detection signal of the door close detection means is ON, the door is closed. When the detection signal of the opening detection means is OFF, the machine tool or the like becomes operable.

However, when the door open / close confirmation / restart prevention storage circuit is provided, the above situation can be prevented. That is, when the detection signal of the door close detection means switches from ON to OFF, the door open / close confirmation / restart prevention storage circuit stores
It goes into the reset state. Here, even if the safety fence door is closed and the detection signal of the door close detection means is turned on and the detection signal of the door open detection means is turned off, the door open / close confirmation / restart prevention storage circuit holds the reset state. And operation becomes impossible.

Here, as long as the door close detecting means is turned off and the detection signal of the door open detecting means is not turned on,
The door open / close confirmation / restart prevention storage circuit does not enter the set state. In the set state, the handle is locked, and a third party cannot close the safety fence door.

Therefore, according to the invention of claim 2, in addition to the effect of the invention of claim 1, it is possible to provide a more reliable interlock device for a safety fence door.

According to a third aspect of the present invention, the door opening detecting means and the door closing detecting means have a limit switch which reacts by operation / reaction of the handle. It is a fence door interlock device.

According to the third aspect of the present invention, the door open / close detection mechanism is provided with a limit switch that responds to the operation of the handle when the safety fence door is opened and closed. Thereby, claim 1
Or, in addition to the effect of the second aspect, it is possible to provide an interlock device for a safety fence door that can be manufactured at lower cost.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIGS. 1A and 1B show a first embodiment of the present invention. This figure is a detailed view of a main part of the safety fence door. In addition, this device is an interlock device 1 shown in FIG.
It is provided in the same part as. Therefore, the description according to FIG. 5 is omitted.

The safety fence 4 and the safety fence door 5 are provided with safety door switches 6 and 7, respectively. Further, a handle 8 is provided on the safety fence door 5 so as to be movable in the left-right direction in the figure. The handle 8 is provided with pin portions 8a and 8b. On the other hand, the safety door switches 6, 7 are provided with lock mechanisms 9, 10, respectively. The lock mechanisms 9 and 10 have lock holes 11 and 12, respectively, and can be fitted with the pins 8a and 8b.

The distance between the safety door switches 6 and 7 is such that the pin portions 8a and (8b) are locked by the lock holes 11 and (1).
When fitted with 2), the other pin portions 8b, (8a)
The lock holes 12 and (11) are provided so that they are not fitted to each other, and one of the pin portions 8a and 8b always fits into the lock holes 11 and 12.

Further, the pin portions 8a and 8b are
1 and 12, the mechanical lock mechanisms 9, 10
As a result, the pin portions 8a and 8b are automatically locked. The safety door switches 6 and 7 are provided with lock release mechanisms 13 and 14 for releasing this lock, respectively.
The lock of the handle 8 by the lock mechanisms 9 and 10 is performed by inserting a key (not shown) into the lock release mechanisms 13 and 14.
It is released only by rotating to UNLOCK side. Here, the key is best carried by a maintenance worker.

In addition, the safety door switch 6 is provided with a limit switch 15 which is a door close detecting means, and the safety door switch 7 is provided with a limit switch 16 which is a door open detecting means. Each limit switch 15,
16 outputs an ON signal when the pins 8a and 8b are fitted into the lock holes 11 and 12, respectively. Limit switch 1
FIG. 2 shows an electric circuit diagram of the present apparatus including the contact points 5 and 16 and the restart prevention means 23.

In FIG. 2, a of the limit switch 15
The contact 15a and the contact b of the limit switch 16 are connected in series, and are connected to a machine restart confirmation circuit 27 via an interlock circuit 26 and an AND circuit 17. On the other hand, the b contact 15b of the limit switch 15 and the a contact of the limit switch 16 are connected in series and connected to the set contact 24a of the door open / close confirmation / restart prevention storage circuit 24.

When a current flows through the set contact 24a, the set flag (1) 24c is raised, and the electrical connection to the machine restart confirmation circuit 27 via the AND circuit 17 is established. In addition, the b contact 15
A rising differential circuit 23a is connected between the b and a contacts 16b, and is connected to a reset contact 24b of the door confirmation / restart prevention storage circuit 24. When a current flows through the reset contact 24b, a reset flag (0) 24d is set.

Next, the operation of the present apparatus will be described. FIG.
(A) shows a state in which the safety fence door 5 is closed. Handle 8
Are locked by a mechanical lock mechanism 9 provided on the safety door switch 6, so that the safety fence door 5
Cannot be opened. Also, since the pin 8a is fitted in the lock hole 11, the limit switch 15
Outputs an ON signal assuming that the safety fence door 5 is in the closed state.

On the other hand, in the safety door switch 7 on the side of the safety fence door 5, since the pin portion 8b is not fitted in the lock hole portion 12, the limit switch 16 outputs an OFF signal. Then, as shown in FIG. 2, the output of the limit switch 15 as the door-closed detecting means is ON and the output of the limit switch 16 as the door-opened detecting means is OFF. It becomes possible.

In the case of intrusion into the safety fence 4 for maintenance work of the machine or the like, after stopping the machine, a key (not shown) is inserted into the lock release mechanism 10 to switch to the UNLOCK side. Then, the lock of the lock mechanism 9 is released. Then, the handle 8 is moved, and the pin 8b is fitted into the lock hole 12. (FIG. 1 (B))

When the pin 8b is fitted into the lock hole 12, the handle 8 (pin 8) is locked by the lock mechanism 10.
b) is locked. Further, when the pin 8b is fitted into the lock hole 12, the output of the limit switch 16 switches from OFF to ON. At this time,
Since the pin 8a and the lock hole 11 are not fitted, the output of the limit switch 15 switches from ON to OFF.

Therefore, referring to FIG. 2, since the output signal of the limit switch 15 which is the door close detecting means is OFF and the output signal of the limit switch 16 which is the door open detecting means is ON, the electrical connection is made. The machine will be shut down and the machine will be inoperable.

When the safety fence door 5 is opened, the handle 8 is locked with the safety fence door 5 open, so that the safety fence door 5 can be operated by a third party even though the worker is in the danger area. There is no possibility that the machine will be operated by closing the lock and releasing the interlock.

Further, the handle 8 is deliberately modified or the like.
When the safety door switches 6 and 7 are provided so that the lock is not locked, the safety fence door 5 can be opened without locking the handle 8 and the danger zone can be entered. In this case, the restart prevention means 23 of FIG. 2 functions.

In order to open the safety fence door 5 in the closed state, the handle 8 is unlocked, and the pin 8a is
Is out of the state, the detection signal of the limit switch 15 becomes O
Switch from N to OFF, b contact 15 conducts, door opening / closing confirmation restart prevention storage circuit 2 by rising differential 25
The reset flag (0) 24d of No. 4 is set.

At this time, since the pin portions 8a and 8b are not fitted into any of the lock holes 11 and 12, the handle 8 is not locked. Therefore, it is possible to enter the dangerous area.

Next, the handle 8 is moved to the safety door switch 6 again, the pin 8a is fitted into the lock hole 11, and the handle 8 is locked. At this time, the limit switch 15 is ON and the limit switch 16 is OFF
However, when the reset flag (0) 24d is set by the AND circuit 17, the machine cannot be operated.

In order to operate the machine, it is necessary to perform a reset operation. The reset operation is performed as follows.
First, the handle 8 is unlocked. Then, the handle 8 is completely moved to the safety door switch 7 side,
The pin 8b is fitted into the lock hole 12.

At this time, the limit switch 15 is turned off.
Since the signal is detected and the limit switch 16 detects the ON signal, the set flag (1) is set. afterwards,
The lock of the handle 8 is released, the safety fence door 5 is closed, and the pin 8 a is fitted into the lock hole 11. The safety fence door 5 is closed, and the handle 8 is locked.

Then, at this time, the detection signal of the limit switch 15 is turned on, the detection signal of the limit switch 16 is turned off, and the set flag (1) 24c
Is standing, so that the machine can be operated.

That is, intentional remodeling or the like is performed, and the handle 8 is not locked by the safety door switch 7;
Assume that the safety fence door 5 can be opened (at an intermediate position of the handle 8). It is assumed that the worker has opened the safety fence door 5 at a position where the handle 8 is halfway, has entered the danger area, and has been working. At this time, even if the third party does not know that there is a worker in the danger area and closes the safety fence door, the machine cannot be operated. Then, the third person can make a soup that there is a possibility that the worker has entered the dangerous area.

Next, FIG. 3 shows a second embodiment. This figure is a detailed view of the main part of the interlock device provided in the same part as that of FIG. 5, as in the first embodiment. In the configuration of the present embodiment, a limit switch 19 is provided on the safety fence door 5 side as door opening detecting means, and a limit switch 20 is provided on the safety fence 4 side as door closing detecting means. The handle 21 is provided so as to be movable in the left-right direction in the drawing. The safety fence 4 is provided with a guide member 22 for guiding the operation of the handle 21.

The safety fence door 5 is further provided with a keyed handle lock cylinder 18. The handle lock cylinder 18 with the key is in the closed state of the safety fence door 5 (FIG. 3).
(A)) and the handle 2 in the open state (FIG. 3 (B)).
Position 1 can be locked. To release this lock, insert and release the key.

The distance between the limit switches 19 and 20 is set at a position where neither of them is turned ON or OFF. The electric circuit of this embodiment is similar to that of FIG. The operation, operation and effect of this embodiment having the above configuration are the same as those of the first embodiment.

FIG. 4 shows the first embodiment or the second embodiment.
FIG. 3 shows another electric circuit diagram instead of FIG. 2 in the case of the mechanical structure component shown in the embodiment. This circuit is publicly known, but can be applied to the mechanical structural parts shown in the first and second embodiments.

An off-delay timer 28 is provided in the electric circuit shown in FIG. 4 for monitoring whether or not the output signal of the limit switch, which is a means for detecting the opening and closing of the door, is being switched within a predetermined time. If no current flows through the off-delay timer 28 for a certain period of time, the off-delay timer 17
The F signal is output, the contact 28a opens, and the interlock operates.

That is, the state in which the time during which both the limit switches of the door open and close detection means are ON or OFF continues for a predetermined time or more is due to the handle 8 being at an intermediate position or the interlock device being modified. The machine was not allowed to operate due to the possibility that it might be present. Therefore, the electric circuit shown in FIG. 4 can cope with intentional remodeling, equipment failure, and the like.

[0047]

According to the first aspect of the present invention, it is possible to prevent an accident caused by an erroneous operation by a third party,
It is possible to provide an interlock device for a safety fence door that can prevent modification and improve safety against equipment failure.

According to the second aspect of the present invention, in addition to the effects of the first aspect of the present invention, when a third party closes the safety fence door without knowing that the maintenance worker has entered the dangerous area. Even the machine can not run. According to the third aspect of the invention, in addition to the effects of the first and second aspects of the invention, it is possible to provide an interlock device for a safety fence door that can be manufactured at a lower cost.

[Brief description of the drawings]

FIG. 1 is a detailed view of a main part according to a first embodiment of the present invention.

FIG. 2 is an electric circuit diagram of the first embodiment of the present invention.

FIG. 3 is a detailed view of a main part of a second embodiment of the present invention.

FIG. 4 is an electric circuit diagram according to another embodiment.

FIG. 5 is an overall view of a conventional example and an embodiment of the present invention.

FIG. 6 is a detailed view of a main part of a conventional example.

[Explanation of symbols]

1 is an interlock device, 2 is a leveler feeder, 3 is a press machine, 4 is a safety fence, 5 is a safety fence door, 6, 7 is a forced opening mechanism, 8 is a handle, 8a and 8b are pins, 9, 10
Is a lock mechanism, 11 and 12 are lock holes, 13 and 14 are lock release mechanisms, 15 and 16 are limit switches, 17
Is an AND circuit, 18 is a handle lock cylinder, 19,
20 is a limit switch, 21 is a handle, 22 is a guide, 23 is a restart prevention means, 24 is a door open / close confirmation restart prevention storage circuit, 25 is a rising differential circuit, 26 is an interlock circuit, and 27 is a machine restart confirmation circuit. , 28 are off-delay timers, and 28a is a contact point.

Claims (3)

[Claims] 1. An interlocking device for a safety fence door provided on a safety fence for preventing a machine tool or the like from entering a danger zone. The safety fence door is provided with the safety fence door. A lock mechanism for holding the safety fence door open or closed by locking the handle position when the safety fence door is open or closed, and a lock for releasing the lock A release mechanism, a door open detecting means for detecting an open state of the safety fence door,
A door closing detecting means for detecting a closed state of the safety fence door, and a machine tool or the like can be operated only when a detection signal of the door closing detecting means is ON and a detection signal of the door opening detecting means is OFF. Is output, and the detection signal of the door close detection means is OFF or the detection signal of the door open detection means is ON.
An interlock device for a safety fence door, comprising: an electric circuit that outputs a signal indicating that the operation cannot be performed to a machine tool or the like in the case of (1). 2. The electric circuit includes a door opening / closing confirmation / restart prevention storage circuit, wherein the door opening / closing confirmation / restart prevention circuit is configured such that the detection signal of the door closing detection means is OFF and the door opening detection 2. The safety fence according to claim 1, wherein when the detection signal of the means is ON, the state is set, and when the detection signal of the door close detection means is switched from ON to OFF, the state is reset by a rising differential circuit. Door interlock device. 3. The door opening detecting means and the door closing detecting means have a limit switch which responds by operation / reaction of the handle.
The interlock device for the safety fence door as described.