JPH09167546A - Key operation type safety switch - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify a locking mechanism of an operation key by locking the operation key in the insertion position in a switch operation state by inserting of the operation key, and making a locking plate retreat to an unlocking position by the operation of an electromagnetic solenoid based on an unlocking instruction. SOLUTION: In the waiting state in which an operation key 4 is drawn out, an operation cam 5 pushes down an operation rod 3 to make a contact 2 off A reset lever 8 is in the retreating position. In this state, when the operation key 4 is inserted into a key insertion head 12, the operation cam 5 is rotated counterclockwise. The operation rod 3 moves in the arrow direction to turn the contact on, and the operation rod 3 is bound so as not to move. When the operation key 4 is unlocked and drawn out, an electromagnetic solenoid is excited and operated. A reset lever 8 goes down, and pushes rightward a lock plate 6 along an inclined cam surface 8a. As a result, the operation key 4 is unlocked.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a key-operated safety switch which is operated by inserting an operation key from the outside and pulling it out to open and close a contact.

[0002]

2. Description of the Related Art The above-mentioned key-operated safety switch is interlocked with, for example, an operation switch of a machine tool or a door locking device of a high-voltage switchboard, and a dedicated operation key (card It is used as a man-machine interface of a safety system that prevents the operation of the machine or the operation of opening the door unless the key is inserted into the switch.

As such a key-operated safety switch, a contact mechanism is provided in a switch case, an operation cam which is rotated in response to an external operation key insertion and removal operation, and a rotation of the operation cam. Then, a structure in which a switch main body including an operation rod for opening and closing the contact mechanism is incorporated is commercially available. On the other hand, in the above-mentioned key-operated safety switch, if the operation key inserted in the switch can be freely taken out by another person, security remains uncertain in terms of security. Therefore, the lock mechanism of the operation key is combined with the switch body, and the operation key inserted in the switch is automatically locked so that it cannot be removed freely, and this state is set unless an unlock command is given externally. It is configured to hold, and either the electromagnetic solenoid or the cylinder lock is selected as the reset (lock release) means of the lock mechanism and combined with the switch body, and the lock is released by the operation of the reset means. A key-operated safety switch having a structure in which the operation key can be pulled out freely is disclosed in Japanese Patent Application No. 6-18 filed by the same applicant as the present invention.
It has already been proposed as No. 6959.

[0004]

In the key operation switch in which the lock lock of the operation key and the reset means for releasing the lock are combined in the switch body as described above, the lock lock of the operation key is taken from the viewpoint of manufacturing cost. It is desirable to configure the means with a mechanism that is as simple as possible. In addition, in order to make the switch applicable to various applications, it is the user's request that the reset means of the switch be equipped with not only an electromagnetic solenoid but also a cylinder lock if necessary, so that Therefore, there is a need to support both electromagnetic solenoids and cylinder locks. In addition, when an electromagnetic solenoid is adopted as the reset means, it is necessary to be able to manually release the lock when the reset operation cannot be performed by energization due to, for example, a power failure or solenoid failure.

Further, in order to enhance the safety in terms of security, it is necessary that the operation cam cannot be turned to the switch operating position even when something other than a dedicated operation key such as a driver is inserted. In this respect, in the conventional configuration proposed above, the operation key locking mechanism is complicated and the product cost is high. In addition, an electromagnetic solenoid and a cylinder lock are used as resetting means, and a cylinder lock as an option is added later. Is difficult. Furthermore, with the conventional configuration, it is possible to turn the operation cam to the switch operating position without inserting the dedicated operation key by inserting, for example, a driver into the key insertion hole, which causes the switch to malfunction. Security concerns remain.

The present invention has been made in view of the above points, and an object thereof is to simplify the locking mechanism of the operation key in response to the above-mentioned demand and to use an electromagnetic solenoid or a cylinder lock as reset means of the locking mechanism. It is to provide a key-operated safety switch that can be easily handled by any of them and has further enhanced safety in terms of security.

[0007]

In order to achieve the above object, according to the present invention, a contact mechanism and a key which rotates in response to an operation key being inserted or pulled out from the outside are provided in a switch case. A key operation type incorporating an operation cam with an engaging claw, a switch body including an operation rod that opens and closes the contact mechanism according to the rotation of the operation cam, and a locking means that locks the operation key in the insertion position. In the safety switch, 1) the locking means is laterally engaged with the stepped groove portion of the operating rod to lock the operating rod in that position, and the locking plate is directed to the locking position. It consists of a biasing spring that presses it, a reset lever arranged opposite to the lock plate, and an electromagnetic solenoid with a plunger for releasing the lock that is connected to the reset lever. The lock plate locks the operation key to the insertion position via the operation rod and the operation cam, and the lock plate is retracted to the lock release position via the reset lever by the operation of the electromagnetic solenoid based on the lock release command. Configure.

2) In the above paragraph 1), the operation cam is locked in the standby position in the switch case when the operation key is pulled out, and the operation cam is unlocked in response to the insertion of the operation key. The second locking means is provided with a slide type cam lock piece arranged on the side of the operation cam with the tip facing the key insertion hole, and the locking piece is locked at the locking position. It is composed of a spring for urging the lock piece and two sets of this lock piece are arranged on the left and right sides of the operation cam.

3) In the above item 1), a cover is provided on the switch case so as to cover the end surface of the electromagnetic solenoid on which the plunger protrudes, and a thin portion that can be pierced from the outside is formed in the surface area of the cover facing the plunger tip. 4) In 1) above, as a locking means for the operation key, a reset mechanism with a cylinder lock for driving and operating the plunger of the electromagnetic solenoid in the unlocking direction is additionally provided, and in this case, the reset mechanism with a cylinder lock is an independent case. The key operation type reset unit is incorporated into the switch unit, and the reset unit is attached to the switch case as an optional item.

In the above structure, when the operation key is not inserted into the switch body, the cam lock piece provided along with the operation cam locks the operation cam at the standby position. Therefore, even if you try to turn the operation key by inserting a driver other than the dedicated operation key into the key insertion hole, the switch will not operate unless you unlock the cam lock piece at the same time. ， The safety in terms of security is improved.

When a dedicated operation key (card type key) is inserted into the key insertion hole of the switch body, the operation key unlocks the lock of the cam lock piece and at the same time the operation cam rotates to the operating position. The contact opens and closes via the operating rod, and the lock plate engages with the operating rod to lock the rod in this position. Further, in the operation key, the engaging claw formed on the operation cam engages with the key at the insertion position. Therefore, the operation key once inserted into the switch body cannot be removed freely.

On the other hand, when the electric signal of the lock release command is given to the electromagnetic solenoid in the operating state of the switch or the cylinder lock of the reset unit additionally provided to the switch is turned, the plunger strokes in the unlocking direction, and A follower reset lever retracts the locking plate from the locking position to release the restraint on the operating rod. As a result, the operation key can be pulled out from the switch body. Then, when the operation key is removed, the operation cam and the operation rod return to their original positions, and the contact is restored. In an emergency situation where the electromagnetic solenoid does not operate due to a power failure, solenoid failure, etc., when only the electromagnetic solenoid is used as the reset means, the thin portion of the case cover facing the tip of the plunger is externally driven by a driver. By breaking through with a tool and pushing the plunger, the lock of the operating rod can be unlocked manually, the operating key can be pulled out, and the contact of the switch can be restored.

A key-operated reset unit incorporating a reset mechanism with a cylinder lock is an independent component,
By preparing this reset unit as an optional product, the function can be diversified by retrofitting the reset unit to the switch according to the application of the switch such as user's request.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. First, in FIGS. 1A and 1B, the switch case 1 is rotated in response to insertion and removal of a contact mechanism 2, an operation rod 3 connected to the contact mechanism 2, and an operation key 4 as a card type key. A switch body composed of a moving operation cam 5 and a lock mechanism for the operation key 4 are provided as a slide type lock plate 6 facing the axis of the operation lock 3, and a biasing force for pressing the lock plate 6 in the lock direction. Each component such as a spring 7, a reset lever 8 facing the other end of the lock plate 6, and an electromagnetic solenoid 10 for reset including a plunger 9 connected to the reset lever 8 is incorporated. In addition, 11 is a terminal block for wiring.

Although not shown, the contact mechanism 2 is biased by a spring in a direction in which the contacts are closed. Further, the operation cam 5 is provided with a box-shaped key insertion head 12 via a support shaft 5a.
The head 12 is provided with an insertion hole 12a for the operation key 4 on the front surface thereof. Further, as can be seen in FIG. 2, a protrusion 5b against which the tip of the operation key 4 abuts and a key locking claw 5c are formed in a bifurcated shape on the upper peripheral surface of the operation cam 5.
Further, a protruding cam portion 5d that abuts on the tip of the operation rod 3 is formed on the lower portion of the peripheral surface.

On the other hand, the lock plate 6 of the locking mechanism is a strip-shaped plate supported slidably in the left-right direction, and has a round hole 6a having a diameter larger than that of the operating rod 3 at the center of the plate surface (see FIG. 2).
Is opened, and the operation rod 3 penetrates through this round hole 6a. On the other hand, a stepped groove portion 3b (see FIG. 2) is formed in the axially intermediate portion of the operating rod 3 so that the lock plate 6 is inserted between the large diameter portions 3a.
Further, the reset lever 8 is formed with an inclined cam surface 7a (see FIG. 2) facing the tip of the lock plate 6, and is connected to the plunger 9 of the electromagnetic solenoid 10. In addition,
The tip of the plunger 9 projects from the switch case 1. In the illustrated embodiment, the projecting portion of the plunger 9 is covered with a cover 1a. Further, a micro switch 13 is provided facing the axis of the plunger 9 to detect the stroke operation of the plunger 9 by the electromagnetic solenoid 10.

Next, the opening / closing operation of the key-operated safety switch having the above-mentioned structure and the operation of locking / resetting the operation keys will be described with reference to FIG. First, in the standby state in which the operation key 4 is pulled out, as shown in FIG. 2A, the operation cam 5 pushes down the operation rod 3 to turn off the contact 2a.
Further, the lock plate 6 contacts the side surface of the large diameter portion 3a of the operation rod 3, and the reset lever 8 is in the retracted position. In this state, as shown in FIG. 2B, the operation key 4 is inserted into the key insertion head 12
(See FIG. 1), the tip of the operation key 4 pushes the projection 5b of the operation cam 5 to rotate the operation cam 5 counterclockwise. As a result, the operating rod 3 is driven by the spring bias along the cam surface in the direction of the arrow (upward) to switch the contact 2a to ON, and at the rising end position of the operating rod 3, the lock plate 6 acts on the bias spring 7. Pushed operation rod 3
The operation rod 3 is fitted into the stepped groove portion 3b of the
Constrain it from moving from this position. At the same time, the locking claw 5c of the operation cam 5 pivots into the square hole 4a of the operation key 4. Therefore, in this state, the operation key 4 is locked at the insertion position and cannot be freely removed.

On the other hand, when the operation key 4 is unlocked and pulled out, the electromagnetic solenoid 10 of FIG. 1 is energized and driven by energization by an electric signal of a lock release command. As a result, the plunger 9 strokes upward by the suction operation of the electromagnetic solenoid 10, and the reset lever 8 connected to the plunger 9 moves downward as shown in FIG. 2C, and moves along the inclined cam surface 8a. The lock plate 6 is pushed rightward against the biasing spring 7. As a result, the lock plate 6 comes out of the stepped groove portion 3b of the operation rod 3 to release the restraint of the rod, and at the same time, the lock of the operation key 4 is released so that the lock plate 6 can be freely pulled out. Then, when the operation key 4 is pulled out, the operation cam 5 rotates clockwise through the locking claw 5c in the pulling-out process, returns to the state of FIG. 2A again, and turns off the contact 2a. When the electromagnetic solenoid 10 is demagnetized after the return, the plunger 9 and the reset lever 8 also return to the standby position. In the embodiment shown in FIG. 1, the reset lever 8 is provided with a contact drive arm 8b, and at the same time, when the lock is released, the operation rod 3 is pushed downward via the arm 8b, and the contact 2a is pulled out before the operation key 4 is pulled out. Is forcibly turned off.

Next, FIGS. 3 and 4 show an embodiment in which a key operation type reset unit is combined with the switch having the above construction.
In FIG. 3, reference numeral 13 denotes a key-operated reset unit in which the cover 1a in FIG. 1 is removed and screwed and attached to the case 1. The reset unit 13 includes a cylinder lock 15 and a cylinder lock in a unit case 14. 1
5, a lever 16 connected to the rear portion is incorporated, and the tip of the plunger 9 protruding from the case 1 into the unit case 14 is in contact with the lever 16 at this mounting position. In addition, 17 is a dedicated key for turning the cylinder lock 15.

With such a structure, when the cylinder lock 15 is not inserted, the operation cam 16 is in contact with the tip of the plunger 9 in a horizontal posture as shown in FIG. 4 (a). From this state, when the key 17 is inserted into the cylinder lock 15 and rotated,
As shown in (b), the lever 16 rotates to push the plunger 9 downward. Therefore, when the key 17 is inserted and rotated in the cylinder lock 15 of the reset unit 13 in the locked state of the operation key 4 described with reference to FIG. 2B, the plunger 9 strokes similarly to the reset operation of the electromagnetic solenoid 10, The reset lever 8 retracts the lock plate 6 to the unlocked position to release the restraint of the operation rod 3. That is, the state shown in FIG.

As can be seen from the above description, the key operation type reset unit 13 described above is prepared as an optional item, and the reset unit 13 is used as a switch case depending on the use of the key operation type safety switch and the situation of use at the site. 1
If it is externally combined, the operation key 4 inserted in the switch can be unlocked from either the electromagnetic solenoid 10 or the reset unit 13. Moreover, since the plunger 9 of the electromagnetic solenoid 10 built into the switch from the beginning is used as it is for the reset operation, the cylinder lock reset mechanism built into the reset unit 13 can be handled with a simple structure.

Next, the configuration of an applied embodiment corresponding to claims 2 to 4 of the present invention will be described with reference to FIG. That is, FIG.
In the key insertion head 12 of the switch case incorporating the operation cam 5, the operation cam 5 serves as a second locking means for locking the operation cam 5 to the standby position without inserting the dedicated operation key. A slide type cam lock piece 18 having its tip facing the key insertion hole 12a and a biasing spring 19 for biasing the cam lock piece 18 to the locking position are additionally provided on both left and right sides of the center of the cam lock piece 12a. . The cam lock piece 18 has a convex portion 18a protruding from the lower end to the front surface of the operation cam 5, and a taper portion 18b obliquely cut toward the key insertion hole 12a is formed at the upper end portion.

With this construction, when the dedicated operation key is not inserted, the convex portion 18a of the cam lock piece 18 pushed up by the biasing spring 19 abuts the lower front surface of the operation cam 5 so that the operation cam 5 is in the standby position. It has a lock on it. Therefore, even if a driver or the like is inserted into the key insertion hole 12a and the operation cam 5 is pushed and rotated, unless the locks of the cam lock pieces 18 arranged on the left and right sides of the operation cam 5 are released at the same time,
It is not possible to operate the switch contact mechanism by turning counterclockwise. This ensures a high security function and prevents malfunction of the switch.

On the other hand, when the regular dedicated operation key (card type key) 4 described in FIG. 1 is inserted into the key insertion hole 12a,
The cam lock piece 18 is pushed down by being pushed by the tip of the operation key 4, the convex portion 18a is disengaged from the operation cam 5, and the lock is released. Then, when the operation key 4 is further pushed, the operation cam 5 rotates and the contact mechanism 2 operates as described in FIG. After resetting, press the operation key 5 to the key insertion head 1
When it is pulled out from 2, the cam lock piece 18 is returned to the locking position by the bias of the spring 19.

Next, as shown in FIG. 1, an application implementation corresponding to claim 5 of the present invention in which only the electromagnetic solenoid with a plunger 10 is equipped as a resetting means and a manual resetting is possible even in an emergency such as a power failure in a used state. An example is shown in FIG.
In this embodiment, a cover 1a made of a resin molded product is attached to the switch case 1 so as to cover the projecting end surface of the plunger 9, and a cylindrical portion 1b serving as a guide bearing at the tip of the plunger is provided on the top surface of the cylindrical portion 1b. A thin portion 1c is formed that has a thin wall thickness and can be easily pierced from the outside.

In such an arrangement, in an emergency when the lock of the operating rod 3 cannot be released even if a reset signal is given due to a power failure, a failure of the electromagnetic solenoid 10, or the like, a tool 20 such as a driver is used to remove the thin portion 1c. When the tip of the plunger 9 is pushed in after being pierced from the outside, the lock plate 6 (see FIG. 1) is retracted to the standby position via the reset lever 8 like the energizing operation of the electromagnetic solenoid 10, and the operating rod 3 is released. Then, the operation key can be pulled out.

[0027]

As described above, according to the structure of the present invention, the dedicated operation key inserted into the switch and the switch contact mechanism can be locked and unlocked by a simple locking mechanism. . Moreover, the reset operation to unlock the lock can be done by the electromagnetic solenoid built into the switch.
By externally attaching the key operation type reset unit that uses the cylinder lock prepared as an option to the switch case, the operation key can be unlocked from either the electromagnetic solenoid or the key operation type reset unit.
The usability for the user is improved accordingly.

Further, with respect to the operation cam incorporated in the case main body, the operation cam is normally locked at the standby position, and when the dedicated operation key is inserted, the operation lock can be released to rotate the operation cam. By providing the second locking means thus configured, the switch cannot be operated by using a key other than the dedicated operation key, which prevents the switch from malfunctioning and improves the security function as the safety system.

Further, even in an emergency situation such as a power failure or solenoid failure in a use state where the resetting means is only the electromagnetic solenoid, the thin wall portion of the case cover facing the plunger tip of the electromagnetic solenoid is pierced to push the plunger. You can manually release the lock with.

[Brief description of the drawings]

1A and 1B are configuration diagrams of an embodiment of the present invention, FIG. 1A is a configuration sectional view of a key-operated safety switch, and FIG. 1B is an arrow view A of FIG.
-A sectional view

2A and 2B are operation explanatory diagrams of the switch having the configuration of FIG. 1, where FIG. 2A is a diagram showing a standby state, FIG. 2B is a diagram showing a locked state in which an operation key is inserted, and FIG. Figure

FIG. 3 is a sectional view showing the configuration of the switch of FIG. 1 combined with a key-operated reset unit.

4A and 4B are operation explanatory diagrams of the reset unit in FIG. 4, where FIG. 4A is a diagram showing a standby state and FIG. 4B is a diagram showing a reset operation state.

5A and 5B are configuration diagrams of a main part of an application example of the present invention in which a locking means of an operation cam is incorporated in a case body, FIG. 5A is a vertical side view of a key insertion head portion, and FIG.

FIG. 6 is a cross-sectional view of the configuration of the essential part showing an applied embodiment of the present invention that enables manual reset in an emergency.

[Explanation of symbols]

 1 Switch Case 1a Cover 1c Thin Part 2 Contact Mechanism 3 Operation Rod 3b Stepped Groove 4 Operation Key 5 Operation Cam 6 Lock Plate 7 Energizing Spring 8 Reset Lever 9 Plunger 10 Electromagnetic Solenoid 13 Key Operated Reset Unit 14 Unit Case 15 Cylinder Lock 16 Lever 17 Key 18 Cam lock piece 19 Energizing spring

Claims (7)

[Claims] 1. A contact mechanism, an operation cam with a key engagement claw that rotates in response to insertion and extraction of an operation key from the outside in a switch case, and following the rotation of the operation cam, In a key-operated safety switch incorporating a switch body composed of an operating rod for opening and closing a contact mechanism, and a locking means for locking an operation key in the insertion position, the locking means is located on the stepped groove portion of the operating rod. A slide type lock plate that engages from one side to lock the operating rod in that position, and a biasing spring that presses the lock plate toward the lock position,
It consists of a reset lever arranged opposite to the lock plate and an electromagnetic solenoid with a plunger for releasing the lock that is connected to the reset lever. The lock plate is operated via the operation rod and operation cam when the switch with the operation key is inserted. A key-operated safety switch characterized in that the key is locked at the insertion position, and the lock plate is retracted to the locking release position via the reset lever by the operation of the electromagnetic solenoid based on the locking release command. 2. The key-operated safety switch according to claim 1, wherein the operation cam is locked in a standby position in the switch case when the operation key is pulled out, and the operation cam is operated in response to insertion of the operation key. A key-operated safety switch comprising a second locking means for releasing the locking. 3. The key-operated safety switch according to claim 2, wherein the second locking means has a slide type cam lock piece having a tip end facing the key insertion hole and arranged on a side of the operation cam. A key-operated safety switch comprising a spring for urging the lock piece to a locking position. 4. The key-operated safety switch according to claim 3, wherein two sets of cam lock pieces are provided on the left and right sides of the operation cam with the operation cam interposed therebetween. 5. The key-operated safety switch according to claim 1, wherein a cover is provided on the switch case so as to cover the end surface of the electromagnetic solenoid on the side where the plunger protrudes, and the cover can be pierced from the outside in the area facing the plunger tip. Key-operated safety switch characterized by forming a thin section. 6. The key-operated safety switch according to claim 1, further comprising a lock mechanism with a cylinder lock for driving and operating a plunger of an electromagnetic solenoid in a lock release direction as a locking means of the operation key. Key-operated safety switch. 7. The key-operated safety switch according to claim 6, wherein a reset mechanism with a cylinder lock is incorporated in an independent case to form a key-operated reset unit, and the reset unit is attached to the switch case as an optional product. Key-operated safety switch characterized by