JP3495384B2 - Safety switch device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to, for example, a door provided at a door of a room or a factory where an industrial machine is installed, or a protective door provided at a danger zone of the industrial machine itself. When the machine is opened, the operation of the internal machine is automatically stopped, or the machine is not operated unless the doors and protective doors are completely closed. The present invention relates to a safety switch device for preventing the occurrence of a failure in advance. 2. Description of the Related Art Conventionally, in Europe, for example, industrial machines have been used as means for preventing accidents caused by a third party accidentally turning on power during maintenance work on industrial machines. Prior to maintenance work, workers must remove all fuses from the bladed switch with fuses and place them in their pockets before starting work.In the United States, maintenance workers turn off the power and then turn on the power The key is locked so that it cannot be performed, and a management method for ensuring the safety of such maintenance work is legally required. However, in such a management method that relies on the awareness of the worker himself, there is a risk that the worker may inadvertently forget and lose the effect. [0003] In the case where a dangerous industrial machine is installed, which may be damaged by being caught in the human body, 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 and turns it on and off, it is necessary to prohibit access to hazardous areas, and to install industrial equipment as long as there is a human body in a room or factory. It is preferable that the operation of the machine is prohibited or the machine is not operated unless the guard door is closed. [0004] A conventional safety switch device used for such an application is such that when a door is closed, a switching actuator attached to the door is inserted into a switch main body and a switch portion is switched, so that an internal switch is switched. The power supply circuit to the installed industrial machine is closed and the industrial machine becomes operable, and the lock mechanism automatically locks the switching actuator so that it does not come out, that is, the door cannot be opened. Mechanically locked, and then the programmable controller circuit activates the solenoid by the detection signal of the stoppage of the industrial machine, releases the lock by the lock mechanism, and opens the door when the industrial machine is in the stopped safe state. It is configured to be openable. [0005] However, if a signal for exciting the solenoid is erroneously input due to a program error or some abnormality in the programmable controller, the industrial machine is not stopped. Regardless, the lock by the lock mechanism is released and the door can be opened. In general, when the lock is released by the lock mechanism, the openable state of the door is displayed to the outside by turning on an indicator light or the like. When the door is opened by the display, the switching actuator is disconnected. When the switch is turned off and the switch is switched, the power supply circuit to the industrial machine is cut off.However, the industrial machine continues to operate for a while with its own operating inertia without being stopped immediately. There is a problem that a very dangerous situation may occur when entering. SUMMARY OF THE INVENTION Accordingly, it is a technical object of the present invention to provide a safety switch device capable of surely stopping a machine when a lock by a lock mechanism is accidentally released. According to the present invention, as a technical means for achieving the above object, a safety switch device is constituted as follows. That is, the switching actuator includes a switching actuator attached to a movable member such as a door, and a main body portion fixedly inserted so that the switching actuator can be inserted and removed by opening and closing the door. A safety device comprising: a switch unit that is switched by an actuator; a lock mechanism that automatically and mechanically locks the inserted switching actuator so as to prevent removal thereof; and a solenoid that unlocks the lock state of the lock mechanism. In the switch device, the switch unit is provided with a main safety switch whose ON state is switched from a normally closed contact to a normally open contact by inserting the switching actuator, and interlocked with an exciting operation for unlocking the solenoid. Sub-safety switch and key for switching the ON state from normally closed contact to normally open contact A key switch that can be turned on from a normally closed contact to a normally open contact by being inserted into the main circuit for supplying power to the machine; and a normally open contact of the main safety switch and a normally closed contact of the sub safety switch. And the normally open contact of the key switch are connected in series, and the normally closed contact of the main safety switch, the normally open contact of the sub safety switch, and the normally closed contact of the key switch are connected to the drive control system circuit of the machine. The contacts are connected so as to close the circuit when all of the contacts are in the off state. When the door on which the switching actuator is mounted is open, the normally open contact of the main safety switch is off and the main circuit for supplying power to the machine is opened. The industrial machine is inoperable. The normally closed contact of the main safety switch is in the ON state, and the drive control system circuit of the machine is also opened. Next, when the door is closed, the normally open contact of the main safety switch is turned on and the solenoid is not energized, and the normally closed contact of the sub safety switch is turned on. The main circuit is closed and the industrial machine becomes operable, and the normally closed contact of the main safety switch and the normally opened contact of the sub safety switch are both off, and the drive control circuit of the machine is also closed. As a result, the machine becomes operable. If the solenoid is erroneously excited due to a program error of the programmable controller or some abnormality during the operation of the industrial machine, the auxiliary safety switch is linked with the exciting operation of the solenoid to change the normally closed contact to the normally open contact. When the normally closed contact is turned off, the main circuit for supplying power to the machine is opened, and when the normally open contact is turned on, the machine drive control circuit is also opened. Becomes inoperable, and the industrial machine is completely stopped by the time the door is opened. The same operation is performed when the solenoid is excited by the detection signal of the stoppage of the industrial machine. A preferred embodiment of the present invention will be described below in detail with reference to the drawings. 1 to 4 each show an electric circuit diagram in each state of one embodiment of the present invention, and the electric circuit diagrams are the gist of the present invention. In order to facilitate understanding of the present invention, first, The schematic configuration of the safety switch device of the present invention will be described with reference to FIGS. FIG. 5 is a plan view of the main body portion, and FIG. 6 is a perspective view of the mounted state. In these figures, the safety switch device of the present invention includes a solenoid unit (2) on both sides of the switch main unit (1). And a key unit (3) are attached to form a main body, and this main body is combined with a switching actuator (4). The switch body unit (1) includes a switch unit (1).
a) and, as shown in FIG. 6, a passive operation unit (1b) which is operated by inserting and removing a switching actuator (4) attached to the door (D) by opening and closing the door (D) to switch the switch unit (1a). In the cover of the passive operation unit (1b), an insertion hole (1) into which the switching actuator (4) is inserted when the door (D) is closed.
c) and (1d) are drilled. The switch body (1) is provided with two insertion holes (1c) and (1d), and can be attached so that the switching actuator (4) can be inserted by selecting one of two orthogonal directions. Things are shown. The main body is attached by screwing an attachment piece (2a) of the solenoid unit (2). A switching operation key (5) of an internal key switch is inserted into and removed from the key unit (3). Next, FIG. 7 shows a plan view of the switch body unit (1) with the lid removed, and the operation of the passive operation unit (1b) of the switch body unit (1) by the switching actuator (4). FIG. 8A showing the process in order.
(C) will be described. A switching actuator (34) attached to a movable body such as a door (D) separately from a main body portion fixed at a predetermined location has two types and three operating pushes with a predetermined step on the tip end surface. Planes (4a) and (4b);
An escape hole (4c) for a cam-like plate, which will be described later, and a return pressing surface (4d) formed by a hole edge surface of the escape hole (4c) are integrally formed. In FIG. 7, the passive operation unit (1b)
Has a support shaft (7) bridged between a pair of support bases (6).
In addition, a driving cam-shaped plate (8) and a pair of regulating cam-shaped plates (9) located on both sides of the driving cam-shaped plate (8) are overlapped with each other and individually rotatably penetrated. As shown in FIG. 8, each of the cam plates (8) and (9) has two notches of the same shape formed corresponding to the two insertion holes (1c) and (1d). The opposing pressure receiving portions (10) and (11) are formed on one of the opposed sides, and the return pressure receiving portions (12) and (13) are formed on the other side. Each of the cam-shaped plates (8) and (9) has a guide cam hole through which a single cam follower pin (14) is inserted, and the guide cam hole (1).
The locking holes (17) and (18) into which the cam follower pins (14) are engaged at the start ends of 5) and (16) are shown in FIGS.
As shown in (c), the guide cam holes (15) and (16) are formed so as to communicate with each other in a protruding state. Is established. A lock lever (21) is provided as a lock mechanism for automatically and mechanically locking the passive operating section (1b) in the switching state of the switch section (1a) when the switching actuator (4) is inserted. Are each cam-shaped plate (8),
Above (9), they are located in a state orthogonal to these and are movably arranged. That is, this lock lever (2
1) is provided on the base bar (22), which is located above and perpendicular to each of the cam-shaped plates (8) and (9), with the engaging step of each of the cam-shaped plates (8) and (9). A U-shaped engaging rod (23) that engages with (19) and (20) is integrally extended, and operating pieces (24) are respectively suspended from both ends of the base bar (22). It is located on both left and right sides of the passive operation unit (1b). The upper part of both ends of the lock lever (21) has a coil spring (25) from the front side.
8 (a) to 8 (c), the lower end of each operating piece (24) is pressed and urged from behind by a coil spring (26). The locking rod (23) is constantly urged to rotate, and is held in a movable state in a state where the locking rod (23) is in contact with the peripheral surface of each of the cam-shaped plates (8) and (9). Further, an operating rod (27) protruding from a solenoid unit (2) attached to a side portion of the switch body unit (1) is inserted through an insertion hole (not shown) of the switch body unit (1). It is in contact with the front side of the lower end portion of the operating piece (24). The operation of the above configuration will be briefly described. When the door (D) is opened and the switching actuator (4) is pulled out of the switch body unit (1), FIG.
As shown in (a), the driving cam-shaped plate (8) and the regulating cam-shaped plate (9) are provided with the respective operating pressure receiving portions (12), (1).
3) is stationary with a rotational phase difference substantially matching the step between the corresponding pressing surfaces (4a) and (4b) of the switching actuator (4), and the guide cam holes (15) and (16).
Are overlapped with each other so as to be able to guide the cam follower pin (14). Therefore, as long as the cam-shaped plates (8) and (9) are not rotated by the switching actuator (4) while maintaining the initial rotational phase difference, that is, if members other than the switching actuator (4) are inserted, the cam follower pins (14) is one of the locking holes (1
7) or (18), each cam-shaped plate (8),
The rotation of (9) is prevented, and the switching operation of the switch section (1a) is prevented. The cam-like plates (8) and (9) are rotated counterclockwise in FIGS. 8 (a) to 8 (c) by a switching actuator (4) inserted into the switch body unit (1). And the cam follower pin (14) is pushed rearward along the guide cam holes (15) and (16), and the guide portions (29) on both sides of the guide body (28).
8 (a) to 8 (c), and is moved in the direction of the arrow A in FIGS. 8 (a) to 8 (c) against the urging force of the return spring (30). When the cam follower pin (14) is moved to the position shown in FIG. 8 (b), a switch switching member (31) having the cam follower pin (14) fixed to the front end and a switch switching body (32) connected thereto are provided. Both move rearward (upward in FIG. 7), and the main safety switch (S1) of the switch section (1a) is switched from a normally closed contact to a normally open contact. At this time, the locking lever (23) of the lock lever (21) slidingly contacting the peripheral end surfaces of the cam-shaped plates (8), (9) by the rotational bias of the coil springs (25), (26). Engages with the engaging steps (19) and (20) as shown in FIG. 8 (b), and prevents the cam-like plates (8) and (9) from rotating clockwise in FIG. I do. Therefore, even if the switching actuator (4) attempts to move in the withdrawal direction, that is, attempts to open the door (D), the return pressing surface (4) of the switching actuator (4).
d) is brought into contact with each of the return pressure receiving portions (12) and (13) of each of the cam-shaped plates (8) and (9) in the rotation preventing state, and the main switch (S1) is switched to the normally open contact state. Locks automatically and mechanically. Next, when the solenoid of the solenoid unit (2) is sucked and driven by the detection signal of the stop of the machine, the operating rod (27) is operated in the direction of the arrow in FIG. Press the lock lever (21)
Is rotated counterclockwise to unlock, and the door (D)
Becomes openable. Next, FIGS. 1 to 4 will be described.
The secondary safety switch (S1) built in the switch section (1a) of the switch body unit (1) and the secondary safety switch composed of a microswitch that is switched in conjunction with the operation of the solenoid (33) of the solenoid unit (2). A switch (S2) and a key switch (S3) that can be switched by manual operation of the key (5) of the key unit (3) are provided. Port for programmable controller circuit (P
1) and (P2), a normally closed contact (b1) of the main safety switch (S1) and a normally open contact (a) of the sub safety switch (S2).
Each parallel circuit of 2) and the normally closed contact (b3) of the key switch (S3) is connected. A normally open contact (a1) of the main safety switch (S1) and a normally closed contact (b2) of the sub safety switch (S2) are provided between the main circuit ports (P3) and (P4) for controlling energization of the machine. ) And key switch (S
The normally open contact (a3) of 3) is connected in series. A solenoid (33) is connected between the solenoid power ports (P5) and (P6). The signal between the ports (P1) and (P2) for the programmable controller circuit is inverted by the inverter (34). Next, the operation of the embodiment will be described. When the door (D) is opened and the switching actuator (4) is pulled out of the switch body unit (1), as shown in FIG. The normally closed contact (b1) of the main safety switch (S1) is on, the solenoid (33) is engaged in a non-excited state, and the normally closed contact (b2) of the sub safety switch (S2) is on. In the same figure, the key (5) is removed from the key unit (3) and the normally closed contact (b3) of the key switch (S3) is turned on.
Therefore, since the normally open contact (a1) of the main safety switch (S1) or the normally open contact (a3) of the key switch (S3) is off, the main circuit port (P
Since the interval between 3) and (P4) is open, the power supply circuit to the machine is cut off, and the machine is in an inoperable state.
In addition, the port for the programmable controller circuit (P
1) and (P2), the main safety switch (S
The closed state by the normally closed contact (b1) of 1) or the normally closed contact (b3) of the key switch (S3) is changed by the inverter (34).
, And is open, and the control system of the machine is also shut off. This state does not change even if the key switch (S3) is switched by inserting and operating the key (5). If the door (D) is unintentionally closed by a third party while the operator is performing a maintenance service in the state of FIG. 4, for example, as shown in FIG. 3, the main safety switch ( S1) is switched from the normally closed contact (b1) to the normally open contact (a1), but since the key switch (S3) is not switched by the key (5), the key switch (S3) is turned off. The normally open contacts (a3) of the main circuit ports (P3), (P3)
4) The open state is maintained for a while to keep the machine inoperable. Therefore, if the key (5) is removed during the operation, the machine is operated unexpectedly only when the door (D) is closed, the door (D) is only locked in the closed state by the lock mechanism. Accident can be prevented beforehand. When the machine is operated, the key (5) is inserted into the key unit (3) from the state shown in FIG. 3 and operated, so that the key switch (S3) is normally closed as shown in FIG. The on state is switched from (b3) to the normally open contact (a3), the main circuit ports (P3) and (P4) are closed, and the machine becomes operable, and the programmable controller circuit port (P1), During the period (P2), the open state is reversed by the inverter (34) to be in the closed state, and the control system of the machine is also in a operable state. At this time, the door (D) is locked in the closed state by the above-mentioned lock mechanism, and safety can be reliably maintained. When the solenoid (33) is energized due to a program error of the programmable controller or some abnormality in the operation continuation state of the machine, the door (D) can be immediately opened.
As shown in (2), the normally closed contact (b2) of the sub safety switch (S2) is turned off by the excitation operation of the solenoid (33), and the port between the main circuit ports (P3) and (P4) is opened, and the machine is connected to the machine. Power supply circuit is shut off and the machine stops after continuing to operate by inertia. At the same time, the normally open contact (a2) of the auxiliary safety switch (S2) is turned on, and the ports (P1), (P
During the period 2), the closed state is inverted by the inverter (34) to be opened, and the control system of the machine is also shut off. Therefore, the state in which the door (D) can be opened is confirmed by an indicator light or the like, and when the door (D) is opened, the machine is completely stopped and the safety can be reliably maintained. The same operation as described above is performed when the solenoid (33) is excited in a normal state by the detection signal of the stop of the machine. FIG. 9 is an electric circuit diagram showing electric wiring when the key unit (3) is omitted. In FIG. 9, the same components as those in FIGS. 1 to 4 are denoted by the same reference numerals. Also in this embodiment, when the door (D) is open, the port between the main circuit ports (P3) and (P4) is opened and the machine cannot be operated, and the door (D) is closed. When the solenoid (33) is erroneously excited due to a programming error of the programmable controller or some abnormality while the machine is operating, the sub-safety switch (S2) is switched, thereby turning on the main circuit. Port (P3) and (P4) are opened to shut off the power supply circuit to the machine, and the programmable controller circuit port (P1) and (P2) are opened to shut off the machine control system. Is done. As described above, according to the safety switch device of the present invention, the main safety switch whose ON state is switched from the normally closed contact to the normally open contact by inserting the switching actuator, and the unlocking of the solenoid. A sub-safety switch that switches the ON state from a normally closed contact to a normally open contact in conjunction with the excitation operation for, and a key switch that switches the ON state from a normally closed contact to a normally open contact by inserting a key are provided. In addition, the normally open contact of the main safety switch, the normally closed contact of the sub safety switch, and the normally open contact of the key switch are connected in series to the main circuit for supplying power to the machine, and the drive control system circuit of the machine is connected. The circuit is closed when the normally closed contact of the main safety switch, the normally open contact of the auxiliary safety switch, and the normally closed contact of the key switch are all off. When the door to which the switching actuator is mounted is open, the industrial machine is inoperable and the control function of the drive control system circuit is shut off, and the door is closed. At this point, the existing safety function is obtained in which the industrial machine is in an operable state and is controlled by the drive control system circuit of the machine and is in an operable state. Also, if the solenoid is erroneously excited during the operation of the industrial machine, the industrial machine can be completely stopped by the time the industrial machine becomes inoperable and the door is opened, and the output of an abnormal signal, etc. Safety can be reliably maintained even in the event of an unexpected event. Further, since the opening and closing of the power supply main circuit and the drive control system circuit can be forcibly performed independently of the excitation operation due to, for example, a failure of the solenoid, safety can be further improved.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an electric circuit diagram of an operating state of a machine according to an embodiment of the present invention. FIG. 2 is an electric circuit diagram showing a state in which a solenoid is suction-driven during operation of the machine. FIG. 3 is an electric circuit diagram in a state where a door is closed and a key is removed from the door. FIG. 4 is an electric circuit diagram in a state where a door is opened and a key is removed. FIG. 5 is a plan view of a main body part according to the first embodiment; FIG. 6 is a perspective view of the same as in the first embodiment. FIG. 7 is a plan view of the switch main unit with the lid removed. 8 (a) to 8 (c) are right side views sequentially showing an operation process of a part of the switch body unit of the above. FIG. 9 is an electric circuit diagram of another embodiment of the present invention. [Description of Signs] 1 Switch body unit (switch body part) 1a Switch section 4 Switching actuator 21 Lock lever (lock mechanism) 33 Solenoid S1 Main safety switch a1 Normally open contact b1 of main safety switch Normally closed contact of main safety switch S2 Secondary safety switch a2 Normally open contact b2 of the secondary safety switch Normally closed contact of the secondary safety switch

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Masanori Nakayasu 1 Toyota Town, Toyota City, Aichi Prefecture Inside Toyota Motor Corporation (56) References JP-A-60-119880 (JP, A) JP-A-60-44926 JP-A-60-148974 (JP, A) JP-A-6-187877 (JP, A) JP-A-58-178778 (JP, A) JP-A-5-123937 (JP, A) JP-A-1-199704 (JP, A) JP-A-63-64449 (JP, A) JP-A-6-43986 (JP, U) JP-A-61-168080 (JP, U) JP-A-60-139996 (JP, A) JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01H 3/00-33/00 E05B 41/00-65/00 B23Q 11/00 F16P 3/00 F23B 29/00 E05F 15 / 00

Claims (1)

(57) [Claim 1] A switching actuator attached to a movable member such as a door, and a main body portion fixedly inserted so that the switching actuator is inserted / extracted by opening / closing a door or the like. A switch unit to be switched by the switching actuator to be inserted into and removed from the main body; a lock mechanism to automatically and mechanically lock the inserted switching actuator to prevent removal; A safety switch device including a solenoid for unlocking the lock state of the mechanism, wherein the switch unit includes a main safety switch that is turned on from a normally closed contact to a normally open contact by inserting the switching actuator; The ON state is switched from a normally closed contact to a normally open contact in conjunction with the excitation operation for unlocking the solenoid. And a key switch whose ON state is switched from a normally closed contact to a normally open contact by inserting a key, and a normally open contact of the main safety switch and a key switch for a main circuit for supplying power to a machine. The normally closed contact of the auxiliary safety switch and the normally open contact of the key switch are connected in series, and the normally closed contact of the main safety switch and the normally open contact of the sub safety switch are connected to the drive control system circuit of the machine. And a normally closed contact of the key switch is inserted and connected so that the circuit is closed when all of the contacts are in an off state.