JP2721634B2 - Contact block for safety switch device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a door for a room or a factory where industrial machines are installed or a protective door provided in a danger zone of the industrial machine itself. By automatically stopping the operation of the machine or preventing the machine from operating unless the doors and guard doors are completely closed, it is possible to prevent the human body from being involved in industrial machinery in advance. The present invention relates to a contact block of a switch unit in a safety switch device for preventing a problem.

[0002]

2. Description of the Related Art Conventionally, as a means for preventing the occurrence of an accident due to a third party erroneously turning on the power during a maintenance work on an industrial machine, for example, prior to the maintenance work on the industrial machine, Make sure that the operator removes all fuses of the bladed switch with fuse and puts them in the pocket before starting work, or locks with a key so that the maintenance worker cannot turn on the power after shutting off the power. I have.
However, in such a management method that relies on the worker's own consciousness, there is a risk that the worker may inadvertently forget and completely lose the effect.

[0003] Therefore, when a dangerous industrial machine is installed, which may be damaged by the human body being caught in it, the door of an entrance or exit of a room or a factory where the machine is installed or the industrial machine itself is installed. By installing a safety switch device that automatically detects the opening and closing of the protective door of a building and turns it on and off, it is prohibited to enter a hazardous area, and as long as there is a human body in a room or factory, an industrially installed The operation of the machine is prohibited or the machine is not operated unless the guard door is closed.

A safety switch device of this kind is generally shown in FIG.
As shown in FIG. 1, a switching actuator (2) mainly attached to a door (4) of a room, and a switch body unit attached such that the switching actuator (2) is inserted and withdrawn when the door (4) is opened and closed. (1)
And a solenoid unit (3) for unlocking which is attached to the side of the switch body unit (1).

The switch body unit (1) is composed of a switch section (1a) and a passive operation section (1b) which is operated by inserting and removing a switching actuator (2) to switch the switch section (1a). For example, the mounting piece (3a) of the solenoid unit (3) is screwed and mounted. Two insertion holes (1c) and (1d) are formed in the cover of the passive operation section (1b) to select and insert the switching actuator (2) in any of two orthogonal directions. In addition, the switching actuator (2) has two types and three operating pressing surfaces (2
a) and (2b) are formed, while a driving cam-shaped plate (not shown) and a regulating cam-shaped plate (not shown) are pressed in the passive operating portion (1b). Surface (2a),
It is stationary at a rotational phase difference substantially matching the step of (2b). Therefore, the passive operation unit (1b) is not operated unless both the cam-shaped plates are rotated while maintaining the initial rotational phase difference by the two pressing surfaces (2a) and (2b) of the switching actuator (2) to be inserted. Has become. That is, even if a member other than the switching actuator (2) is inserted, the rotation of each cam-shaped plate is prevented, and the switching operation of the switch section (1a) is not performed.

When the door (4) is closed, the switching actuator (2) inserted into the switch body unit (1) rotates the respective cam-shaped plates of the passive operating portion (1b) forward, thereby operating the operating rod. The body (not shown) is linearly moved rearward, and a contact holder (to be described later) of the switch unit (1a) moves integrally with the operation rod and the switch unit (1b).
After that, the passive operating portion (1b) is mechanically locked by a lock mechanism so as to prevent the switching actuator (2) from moving in the removal direction.
Conversely, after the lock by the lock mechanism is released by the operation of the solenoid unit (3), the cam-like shape is formed by the switching actuator (2) which moves in the pulling-out direction from the switch body unit (1) when the door (4) opens. When the plate is rotated in the opposite direction, the contact holder is moved integrally via the operating rod body, and even if welding occurs between the contacts of the switch section (1b), the contact section is forcibly opened and the switch section (1b) is opened. Is switched to the original state.

Next, the configuration of the conventional switch section (1a) in the safety switch device will be described with reference to FIGS. 8 is a partially cut-away plan view of a contact block (5) inside the switch section (1a), FIG. 9 is a right side view of the entire switch section (1a), and FIG. FIG. 11 is a cut rear view of the same contact block (5) cut along the contact portion. In these figures, the switch section (1a) has a configuration in which a contact block (5) is provided inside a switch case (6) covered with a case lid (27) as shown in FIG. I have. As shown in FIG. 8, a pair of terminal plates (9) each having a normally closed fixed contact (8) are fitted to the contact block (5) on both left and right sides of the front end in the unit case (7). Terminal plates (11) each having a normally open fixed contact (10) are fitted to the left and right sides of the rear end. Then, as shown in FIG. 8, a groove-shaped recess (12) formed in the front-rear direction at the center of the unit case (7)
A contact holder (13) is movably inserted. The contact holder (13) is provided with a holding hole (14) at the center thereof. The holding hole (14) has a pair of normally-closed movable contacts (15) at both ends. A plate (16) and a normally open terminal plate (18) having a pair of normally open movable contacts (17) at both ends are inserted in a state of being opposed to each other, and both terminal plates (16), (18) Contact pressure spring (1)
9) are interposed to urge them in the direction away from each other. The normally closed fixed contact (8), the normally closed movable contact (15), and the normally closed terminal plate (16) constitute an auxiliary switch circuit that stops the operation of the industrial machine or the like when in the ON state. On the other hand, the normally open side fixed contact (10), the normally open side movable contact (17), and the normally open side terminal plate (18) constitute a safety switch circuit that enables the operation of industrial machines and the like in the ON state. I have.

An operating rod body (2) of a passive operating portion (1b) linearly moved in the front-rear direction in conjunction with the insertion / removal of the switching actuator (2) at the front end of the contact holder (13).
0) An inverted L-shaped hook-shaped engaging portion (22) is engaged with the connecting engaging portion (21) at the rear end from above and connected so as to move integrally with the operating rod body (20). Has been established. Further, the upper opening of the unit case (7) is covered with a unit cover (23) and is held by the unit cover (23) without removing the contact holder (13). 9 and the return spring (2) shown in FIG.
In 4), the contact holder (13) is urged forward, and the normally closed movable contact (15) is pressed against the normally closed fixed contact (8). The terminal plates (9) and (11) are connected to terminal screws (2).
5) By being wired in (26), it is inserted and connected to a power supply circuit of an industrial machine or the like to be operated and controlled.

[0009]

By the way, in the above safety switch device, the door (4) is closed and the switching actuator (2) is inserted into the switch body unit (1) for passive operation. Each cam-shaped plate of the body (1b) is rotated forward, and in conjunction therewith, the operating rod body (20)
Is linearly moved backward, and this operation rod body (2
The contact holder (13) is moved backward integrally with the operation rod body (20) by the engagement part (22) being fitted to the coupling engagement part (21) of (0). The normally closed movable contact (15) is associated with the rearward movement of the operating rod body (20).
Is released from the normally closed fixed contact (8), and the auxiliary switch circuit is turned off. Subsequently, the normally open movable contact (17) comes into contact with the normally open fixed contact (10) to turn on the safety switch circuit. By being in the state, the internal industrial machine and the like become operable. Immediately thereafter, each cam-shaped plate of the passive operating body (1b) is locked by the lock mechanism. That is, in the contact block (5) of the switch section (1a),
Since the normally open movable contact (17) needs to be maintained in a reliable switching state in which the normally open movable contact (17) is pressed against the normally open fixed contact (10) with a predetermined contact pressure by the urging force of the contact pressure spring (19). (19) is compressed and the normally open movable contact (1
When the contact holder (13) moves to a state where the contact holder (7) comes into pressure contact with the normally-open fixed contact (10), the lock mechanism operates to lock each cam-shaped plate, thereby causing the switching actuator (2) to operate. The operation rod body (20), that is, the contact holder (13) is prevented from moving forward in the removal direction, and the switching state by a predetermined contact pressure is maintained.

As described above, the auxiliary switch circuit is turned off in the switch section (1a) and the safety switch circuit is turned on in the switch section (1a). It is configured to operate according to the procedure of locking by a mechanism. However, when closing the door (4), the operation of closing the door (4) may be stopped when the auxiliary switch circuit is turned off and the safety switch circuit is turned on. That is, since the door (4) is not completely closed, the operation of closing the door (4) may be stopped in a state where the passive operating body (1b) is not locked by the operation of the lock mechanism in the passive operating body (1b). Thereafter, when the safety switch circuit is turned on, the internal industrial machine or the like becomes operable, and the unlocked door (4) is slightly opened due to vibration or the like caused by the operation of the industrial machine or the like. There is. As a result, the safety switch circuit is turned off and the operation of the industrial machine or the like stops, so there is no problem in safety.However, it is extremely inconvenient in operation that the industrial machine or the like that has started once stops for no reason. . In particular, a serious problem occurs when automatic control is performed according to a certain sequence.

SUMMARY OF THE INVENTION It is a technical object of the present invention to provide a contact block of a safety switch device having a structure capable of switching a contact immediately after a lock is applied in a passive operation section. is there.

[0012]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a method of inserting or removing a switching actuator attached to a door into or from a switch body unit.
The switch portion of the safety switch including a lock release unit for releasing a locked state applied to the passive operation portion when the operation rod body of the built-in passive operation portion moves and the switch portion is switched when the insertion of the actuator is completed. A contact block that is connected to the operating rod body and moves integrally therewith; a contact holder that movably holds the movable contact in a direction approaching and moving away from the fixed contact; and a contact holder provided in the contact holder. A locking projection having an inclined surface on a side opposite to the holder shaft, a reversing spring interposed between the contact holder and the holder shaft, and an inclined surface of the locking projection of the contact holder. And a locking spring disposed on the side of the locking member and pressing the locking member toward the contact holder. In the process of moving the holder shaft when the switching actuator is inserted,
From the point when the locking projection of the contact holder hits the locking member,
The reversing spring is compressed until the tip of the holder shaft on the moving direction side contacts the contact holder, and immediately after the passive operating portion is locked, the locking member moves over the inclined surface of the locking convex portion. It is characterized in that the contact holder is pushed by the restoring force of the reversing spring and the contact is switched at this point.

[0013]

When the door is closed, the switching actuator is inserted into the switch body unit, whereby each cam-shaped plate is rotated, and the operating rod is linearly moved rearward, and is integrated with the operating rod. The holder shaft is also moved backward. At this time, by setting the spring pressure of each of the reversing spring and the locking spring and the inclination of the locking projection, the locking projection comes into contact with this locking member, and then the tip end of the holder shaft in the moving direction side. Until the contact of the contact holder with the contact holder, the movement of the contact holder is prevented against the movement of the holder shaft, and the reversing spring interposed between the contact holder and the holder shaft is compressed.

Then, when each cam-shaped plate is rotated by a predetermined angle, each of the cam-shaped plates is mechanically locked by a lock mechanism, so that the operation rod body and the holder shaft are prevented from moving forward. . Immediately thereafter, the tip of the holder shaft in the moving direction abuts against the contact holder, the contact holder is forcibly moved slightly backward, and the locking member slides on the inclined surface and is pushed up onto the locking convex portion. Can be As a result, the contact holder is forcibly pushed backward by the restoring force of the compressed reversing spring, the normally-closed movable contact separates from the normally-closed fixed contact, the auxiliary switch circuit is turned off, and The open side movable contact is pressed against the normally open side fixed contact, and the safety switch circuit is turned on. Therefore, the safety switch circuit is
Next, after the unlocking unit is operated to release the locked state, the ON state is reliably maintained at a constant contact pressure until the switching actuator moves in the removal direction by the operation of opening the door.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a partially cut-away plan view of a contact block according to an embodiment of the present invention, FIG. 2 is a cut-away right side view in which a central portion thereof is cut, and FIG. 3 is each contact (8), (10), and (15). , (17) are cut right side views, respectively. In these figures,
8 to 10 are denoted by the same reference numerals and the description thereof will be omitted, and only different points will be described below. The cut rear view is the same as that in FIG.

A portion corresponding to the contact holder (13) in the existing contact block (5) is a holder shaft (2).
8) and a contact holder (29). The contact holder (29) is provided with an existing contact in a rear configuration in which the normally closed terminal plate (16) and the normally open terminal plate (18) are biased and held in a direction away from each other by a contact pressure spring (19). It is the same as the holder (13), and the front side portion has a cavity for inserting a reversing spring (38) to be described later, as shown in FIG. Guide slide portions (30) and (31) are respectively formed on the upper and lower portions on both sides, and a pair of left and right engagement pieces (32) are projected from the upper front end, respectively.
Correspondingly, the front end of the lower guide slide portion (31) rises upward to form an engagement step (33), and furthermore, a locking projection (3) having a rear end surface having an inclined surface at an appropriate position on the upper surface.
4) is integrally formed.

On the other hand, an engaging portion (35) which engages with the coupling engaging portion (21) of the operating rod body (20) is provided on a holder shaft (28) disposed in front of the contact holder (29). The slide piece (36) is integrally extended rearward from both left and right sides of the main body portion formed with ()). Each slide piece (36) is slidably held between the engagement piece (32) and the engagement step (33) of the contact holder (29).
Then, a pair of pull-back pieces (37) for forcibly opening in both vertical directions from the rear end portions of both slide pieces (36).
Are formed integrally with each other, and the respective return pieces (37) slide on the upper and lower guide slide portions (30) and (31). As shown in FIGS. 1 and 2, a reversing spring (38) for urging the contact holder (29) and the holder shaft (28) in a direction away from each other is provided between the contact holder (29) and the holder shaft (28). As shown in FIG. 4, each pull-back piece (37) comes into contact with the engagement piece (32) and the engagement step (33), and the holder shaft (28) is prevented from coming off from the contact holder (29).

As shown in FIG. 2, a housing (40) is provided on the unit lid (39) for covering the contact block.
In the housing portion (40), a locking member (41) whose lower end is formed on a slope corresponding to the inclined surface of the locking projection (34) is vertically movable in the accommodation portion (40). The locking member (41) is housed and the locking spring (4) is
2), the locking member (41) is normally pressed against the upper surface of the contact holder (29) at a position near the rear of the locking projection (34), as shown in FIG. The reversing spring (38) has a higher spring pressure than the contact pressure spring (19) in order to obtain a predetermined contact pressure.

Next, the operation of the above embodiment will be described in detail with reference to FIGS. 5 and 6, each of (A) to (D) shows a schematic vertical cross section, and each of (a) to (d) respectively corresponds to (A) to (D).
FIG. 4 shows a schematic plan view of a contact portion in the state of FIG. First, the operation when the door (4) is closed will be described with reference to FIG. When the door (4) is open, that is, when the switching actuator (2) is not inserted into the switch body unit (1), the holder shaft (28) is at the lowest position as shown in FIG. At the front end, the normally closed movable contact (15) is pressed against the normally closed fixed contact (8) by the contact pressure spring (19) as shown in FIG. Have been.

Next, the door (4) is closed and the switching actuator (2) is inserted into the switch body unit (1), whereby the operating rod body (20) of the passive operating section (1a) is moved. When moved rearward, the holder shaft (28) is moved rearward integrally with the operation rod body (20) as shown in FIG. At this time, the contact holder (29) is determined by the relationship between the spring pressures of the reversing spring (38) and the locking spring (42) and the angle of the inclined surface of the locking projection (34).
Is set to be kept without moving. Accordingly, only the holder shaft (28) is moved backward while compressing the reversing spring (38). Then, as shown in FIG. 3B, the rear ends of the two slide pieces (36) of the holder shaft (28) are forcibly pushed from the time when the rear ends of the slide pieces (36) come into contact with the contact holder (29), so that the contact holder (29) is pressed. ) Begins to move backwards.

When the contact holder (29) is forcibly moved rearward, as shown in FIG.
The locking member (41) is provided along the slope of (4) by the locking spring (4).
2) is pushed up while compressing it, and when the contact holder (29) moves just before the locking member (41) rides on the upper surface of the locking projection (34) as shown in FIG. Then, the cam-shaped plate is locked by the lock mechanism in the passive operating portion (1b), so that the holder shaft (28) is prevented from returning forward.

Immediately thereafter, when the locking member (41) rides on the locking projection (34) as shown in FIG. 4D, the braking action on the contact holder (29) by the locking member (41). Is reduced, the contact holder (29) is pushed rearward by the restoring force of the reversing spring (38) that has been compressed, and the normally closed movable contact (15) as shown in FIG. Is released from the normally closed fixed contact (8) and the auxiliary switch circuit is turned off, and then the normally open movable contact (1) is turned off.
7) is pressed against the normally open fixed contact (10) by the urging force of the contact pressure spring (19) to turn on the safety switch circuit,
The internal industrial machines and the like become operable. in this way,
After the passive operating section (1a) is locked, the auxiliary switch circuit is turned off and the safety switch circuit is turned on by the compressed restoring force of the reversing spring (38).
The safety switch circuit operates until the switching actuator (2) starts moving in the withdrawal direction by the opening operation of the door (4) after the solenoid unit (3) is operated to release the locked state. The ON state is reliably maintained with a constant contact pressure by the contact pressure spring (19).

Next, the operation when the door (4) is opened will be described in detail with reference to FIG. FIG.
In the state where the door (4) shown in (a) is closed, the locked state is released by the operation of the solenoid unit (3), and when the door (4) starts to open, as shown in FIG. The shaft (28) is moved forward together with the operating rod body (20). The contact holder (29) has a locking projection (34) with a locking member (41) provided with a locking spring. The movement is prevented because of being pressed by the large urging force of (42).

The holder shaft (28) has its rear end withdrawal piece (37) and the upper and lower guide slides (3).
0) and (31), when the holder shaft (28) is moved to a position where it comes into contact with the locking piece (32) and the locking step (33) of the contact holder (29), the holder shaft (28) is moved. 2
9) is forcibly moved forward, and when the locking projection (34) slightly slides with respect to the locking member (41) as shown in FIG. Since the urging force on the normally-open side movable contact (17) due to is lost, the normally-open side movable contact (17) is not completely separated from the normally-open side fixed contact (10) as shown in FIG. Then, the safety switch circuit is turned off and the operation of the industrial machine or the like is disabled. The contact holder (29) is further moved forward, and as shown in FIG.
Immediately before reaching the slope of 4), the auxiliary switch circuit is turned on and the operation of the industrial machine or the like is disabled as shown in FIG. 4D, and the switching actuator (2) is connected to the switch body unit (1). 5 (A) at the time of exit from
It returns to the initial state shown in.

[0025]

As described above, according to the contact block of the safety switch device of the present invention, when the door is closed, the contact holder is moved with respect to the holder shaft which moves integrally with the operation rod body of the passive operation unit. The locking projection is prevented from contacting the locking member urged by the locking spring having a large spring pressure, thereby preventing the reversing spring interposed between the contact holder and the holder shaft. Immediately after the passive operation unit is locked by the lock mechanism, the locking member is forcibly pushed up onto the locking protrusion, and the contact holder is pushed by the restoring force of the compressed reversing spring to switch the contacts. Therefore, if the door is not completely closed until the passive operation unit is locked by the operation of the lock mechanism, the internal industrial machine will not be in an operable state because the contact is not switched. The lock is subjected to after becoming a state to completely block the opening operation due to vibration or the like of the door,
Since the contacts are switched, the safety switch circuit consisting of the movable contact and the fixed contact moves the switching actuator in the removal direction by opening the door after the unlocking unit operates and releases the locked state. As long as the ON state is maintained with a certain contact pressure unless
It is possible to reliably prevent the inconvenience that the industrial machine or the like that has once started operation suddenly stops operating.

[Brief description of the drawings]

FIG. 1 is a partially cut plan view of an embodiment of the present invention.

FIG. 2 is a right side view of the same cut at the center.

FIG. 3 is a right side view of the same cut along a contact portion;

FIG. 4 is a schematic perspective view of a main part of the above.

FIG. 5 is an operation explanatory view of the embodiment shown in FIG. 1;

FIG. 6 is an operation explanatory view of the embodiment shown in FIG. 1;

FIG. 7 is a perspective view of a mounted state of the safety switch device to which the present invention is applied.

FIG. 8 is a partially cut plan view of a conventional contact block.

FIG. 9 is a cut-away right side view of the same, cut at the center of the entire switch unit.

FIG. 10 is a right side view of the same, cut along a contact portion.

FIG. 11 is a cutaway rear view of the same.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Switch body unit 1a Switch part 1b Passive operation part 2 Switching actuator 3 Solenoid unit (lock release unit) 4 Door 8 Normally closed fixed contact 10 Normally open fixed contact 15 Normally closed movable contact 18 Normally open movable contact Reference Signs List 20 operation rod body 28 holder shaft 29 contact holder 38 inversion spring 41 locking member 42 locking spring

 ──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-60-44926 (JP, A) JP-A-61-71515 (JP, A) JP-A-64-14834 (JP, A) JP-A-6-14834 52748 (JP, A) Japanese Utility Model 4-21037 (JP, U) Japanese Utility Model 4-52321 (JP, U) Japanese Utility Model 5-87759 (JP, U) Japanese Utility Model Utility Model 6-43986 (JP, U) US Patent 4,395,608 (US, A) US Patent 4,658,102 (US, A) US Patent 4,695,684 (US, A) US Patent 4,963,706 (US, A) European Patent Application Publication 117396 (EP, A) European Patent Application Publication 184033 (EP, A A) International Publication 90/8396 (WO, A)

Claims (1)

(57) [Claims] 1. A door insert or move the operating rod of the passive operation section built by dropping off the switch main unit attachment et al was switching actuator switch portion is switched to, the insertion end of the actuator in safety switch with lock release unit for releasing the locked state is subjected to the passive operation section, a contact block disposed in said switch portion, a holder that moves integrally coupled to the operating rod body a shaft, a contact holder for movably holding in a direction toward and away from the fixed contacts a variable dynamic contact, et al provided in the contact holder
And an inclined surface on the side opposite to the holder axis.
A locking protrusion One, sandwiched between the contact holder and the holder shaft
The inverted spring inserted and the inclined surface side of the locking projection of the contact holder
And a locking member provided on the contact holder.
A locking spring that presses the holder shaft during the insertion of the actuator.
In the moving process, the locking projection of the contact holder is a locking member.
From the point when the
The reversing spring is compressed before contacting the contact holder.
Immediately after the passive operating part is locked,
The material is located on the locking protrusion beyond the inclined surface of the locking protrusion.
At this point, the contact holder is restored by the restoring force of the reversing spring.
A contact block for a safety switch device, characterized in that a contact is switched by pressing a contact.