JP3457369B2 - Safety switch - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an industrial machine which is mounted on a wall such as an entrance of a room where the industrial machine is installed, and the door of the entrance is opened. The present invention relates to a safety switch for stopping power supply to a device or the like and bringing a room into a safe state. 2. Description of the Related Art In a room where an industrial machine is installed, in a factory or in a danger zone of the industrial machine itself, a room or a room is provided for the purpose of preventing the occurrence of troubles such as an operator being caught in the machine and causing injury. When the doors of the danger zone are not completely closed, it is required to provide a system for locking the drive of the machine. For this reason, safety switches are provided at entrances and exits such as danger zones. [0003] In such a safety switch, the switch body is mounted on the wall around the entrance of the room, and when the door at the entrance is closed, the actuator fixed to the door enters the operation section of the switch body, whereby A switch with a structure in which the movable contact (movable piece) of the contact block switches. With such a switching operation, the circuit connection switches to the main circuit (power supply circuit for industrial machinery) side and the machine in the room operates. It is possible. However, according to this type of safety switch, even when the door is closed, the door may open due to a recoil at the time of closing, and the door may be closed due to the inclination of the door. The door may open under its own weight. Further, even if the door is normally closed, the door may be opened due to the vibration of the machine after the driving of the machine in the room is started, and in such a case, the following problem occurs. . That is, when a closed door is opened due to a recoil or its own weight at the time of closing, the power supply is immediately stopped after the machine becomes drivable, which adversely affects the electrical system of the machine. Problem. Further, when the door is opened due to the vibration of the machine, the machine is immediately stopped at that time, which causes a serious problem in operating efficiency and the like. In particular, when the industrial machine is automatically controlled in a predetermined sequence, the problem is remarkable. Although this type of safety switch is sometimes used as a substitute for a safety plug, the actuator may come off due to the weight of the chain even in this case.
The same problem occurs. The present invention has been made in view of such circumstances, and an object of the present invention is to provide a safety device having a structure in which an actuator cannot be disengaged by a reaction force at the time of closing a door or an action force of a machine vibration in a room. To provide a switch. [0009] To achieve the above-mentioned object, a configuration for achieving the above object is shown in Figs. 1 to 3 and 6 corresponding to an embodiment.
The present invention will be described with reference to FIG.
02 enters the operation unit 111 of the switch body 101, and the operation rod 7 of the switch unit 112 moves in accordance with the operation switch. Is composed of a pressing piece 121 at the tip and supporting pieces 122 and 123 supporting both ends thereof.
Are rotated in accordance with the entry of the actuator 102, and the plate cams 1 and 3 having the concave portions 1a and 3a formed on the outer peripheral surface thereof and into which the pressing pieces 121 of the actuator are fitted, and both ends of the cam shaft 4 A support frame 11 for supporting, groove cams 1c... 3c formed on the plate cams 1..
The guide holes 12, formed along the direction of movement of the operating rod 7, respectively, at portions facing the grooved cams 1c,.
12 are fitted into the holes 12 and the groove cams 1c,... 3c, both ends of which reach the outer sides of the support frames 11 and 11, and the pins 6 to which the ends of the operating rod 7 are connected.
And a stop member 8 located on at least one of both ends of the pin 6. The stop member 8 is a member formed with a ridge having two surfaces 8 a and 8 b inclined with respect to the direction in which the guide hole 12 extends, and the slope 8 a of the ridge is formed along a plane orthogonal to the pin 6. , 8b are displaceably disposed between a position intersecting with the guide hole 12 and a position not interfering with the hole 12, and are pressed toward the guide hole 12 by an elastic body (compression coil spring) 9. It is characterized by having. When the actuator 102 enters the operating section 111, the plate cams 1... 3 rotate, and the pin 6 is pushed out by the groove cams 1c.
Move along 2. In response, the operating rod 7 moves forward and the connection contact of the switch unit 112 is switched. Further, the pressing piece 121 at the tip of the actuator 102 which has entered the operating section 111 is locked by the concave portions 1a..3a of the plate cams 1 ... 3 (FIG. 2B). Here, pin 6
Move along the guide hole 12, the end of the pin 6 pushes the slope 8a of the ridge of the stop member 8, and the stop member 8 is displaced in a direction away from the guide hole 12 [FIG. )
When the pin 6 further moves and its end exceeds the top of the crest of the stop member 8, the stop member 8 is returned by the elastic force of the elastic body 9 and the pin is set on the other slope 8b of the crest. 6 is restricted [FIG. 4 (b)]. This restricts the rotation of the plate cams 1... 3, and prevents the rotation of the plate cams 1... 3, that is, the retraction of the operation rod 7 unless the actuator 102 is pulled out by a force that overcomes the elastic force of the elastic body 9. . Embodiments of the present invention will be described below with reference to the drawings. First, the schematic structure of the safety switch will be described with reference to FIG. The safety switch of this example is a switch electrically connected to an industrial machine installed in a room, and is mainly composed of a switch body 101 and an actuator 102. The switch main body 101 is fixed to the peripheral wall surface of the doorway of the room. Further, the actuator 102 is fixed to the door 103, and is located at a position facing the insertion hole 101a of the switch main body, and enters the operation section 111 of the switch main body 101 when the door 103 is closed. When the actuator 102 enters, the connection contacts of a contact block (not shown) built in the switch unit 112 are switched (B contact → A contact), and the machine in the room becomes drivable. On the other hand, when the actuator 102 comes out of the operation unit 111 due to the opening of the door 103, the B contact is restored and the power supply to the machine is turned off. The actuator 102 includes an operation unit 1
An insertion portion into the housing 11 is constituted by a pressing piece 121 at a distal end and a pair of supporting pieces 122 and 123 supporting both ends thereof.
The distal end surfaces of the pressing pieces 121 are pressing surfaces (for operation) 121a and 121b in which convex portions and concave portions are formed by step portions. The switch main body 101 has an insertion hole 101b on the upper surface side of the main body in addition to the insertion hole 101a, and any one of the insertion holes 101a or 101b is provided depending on the situation of the installation place. You can choose. Next, the mechanism of the operation unit according to the embodiment of the present invention will be described below with reference to FIGS. 1 is a horizontal sectional view of the operation unit 111, and FIG. 2 is a central vertical sectional view thereof. FIG. 3 is a sectional view taken along the line AA of FIG. First, the operation unit 111 is provided with a plate cam 1 located at the center and a pair of left and right plate cams 2 and 3 arranged on both sides thereof. Each of these plate cams 1,
Reference numerals 2 and 3 are rotatably supported on the camshaft 4 independently of each other. Both ends of the camshaft 4 are supported by the support frame 1 respectively.
It is supported by 1,11. The camshafts 4 are fitted with torsion coil springs 5 between the support frame 11 and the plate cams 1. 3, and the plate cams 1. A rotational force is applied to the support frames 11, 11 in a direction opposite to the rotational direction of the cam (the direction of the arrow in FIG. 2B). Of the three cams, the central plate cam 1 is a cam corresponding to the pressing surface 121a of the concave portion of the actuator 102 shown in FIG. The cams 2 and 3 each have an actuator 102
Are cams corresponding to the pressing surfaces 121b of the convex portions of the cam. Since the plate cams 2 and 3 have the same shape, the reference numerals of the respective portions of the plate cam 2 are omitted below. Insert holes (for actuators) 101a and 10
1b, corresponding to rectangular recesses 1a, 3a and 1b,
3b are formed, and groove cams 1c and 3c are formed to extend to a position at an angle of about 90 ° on the opposite side of the concave portion with respect to the camshaft 4 therebetween. A cam follower pin 6 is inserted into each of the groove cams 1c and 3c. Both ends of this pin 6
Guide holes 12 provided in the support frames 11
12, and project to the outside of the side of the support frame 11 through the holes 11. Here, the guide holes 12, 12 are holes for regulating the moving direction of the cam follower pin 6, and are formed along a plane passing through the center of the cam shaft 4 and parallel to the longitudinal direction of the switch body 101. ing. An end of an operation rod 7 is connected to the cam follower pin 6, and the operation rod 7 moves forward and backward with the movement of the pin 6. The operating rod 7 is a rod for switching the connection contact of the switch unit 112. At both ends of the cam follower pin 6, stop members 8, 8 are provided, respectively, and this structure is a remarkable feature of the embodiment of the present invention. As shown in FIG. 3, each stop member 8 is a member formed with a crest having two surfaces 8 a and 8 b inclined with respect to the direction in which the guide hole 12 extends, and a guide groove provided in the support frame 11. It is arranged along 13 and is displaceable in a direction orthogonal to the guide hole 12, and is pressed toward the guide hole 12 by the compression coil spring 9. The displacement of each stop member 8 toward the guide hole 12, that is, the movement of the stop member 8 on the ascending side is restricted by the fact that the peak portion contacts the cam follower pin 6, and the stop member 8 is moved by the elasticity of the compression coil spring 9. When pressed downward against the force, the peak can be displaced to a position where it does not interfere with the guide hole 12. In this embodiment, three plate cams 1... 3 are provided because the plate cams 1... 3 are pressed by the uneven pressing surfaces 121 a and 121 b of the actuator 102, respectively. The cam follower pin 6 can be moved along each of the groove cams 1c and 3c only when they rotate in synchronization with each other. The operation plates other than the dedicated actuator 102 are inserted into the insertion holes 101a and 101b. This is a configuration for preventing the operation unit 111 from operating even if the operation unit 111 is inserted. Next, the operation of the embodiment of the present invention will be described with reference to FIG. 4 and FIGS. 1 to 3 and FIG. First, the actuator 102 enters the inside of the operation unit 111 through the insertion hole 101a, and the pressing surface 121 at the tip thereof.
When the a and 121b come into contact with the respective plate cams 1 and 3 (FIG. 2 (a)), the cam follower pin 6 is moved as shown in FIG.
The guide hole 12 is located at the end on the camshaft 4 side, and is in contact with the slope 8 a of the stopper member 8 on the camshaft 4 side. Next, when the actuator 102 further enters, the plate cams 1 and 3 rotate in response to this, and the cam follower pins 6 are pushed forward by the groove cams 1c and 3c by this rotation, and are moved along the guide holes 12. Move and
In response, the operating rod 7 moves forward. In the course of the movement of the cam follower pin 6, this pin 6
The slope 8a of the mountain of the stop member 8 is pressed,
As shown in FIG. 4A, the stop member 8 is displaced in a direction away from the guide hole 12 (downward). Thereafter, when the actuator 102 further enters and the cam follower pin 6 moves, the pin 6 passes over the top of the crest of the stopper member 8 and comes into contact with the other slope 8b, and the cam follower pin 6 further moves. When it is moved, the connection contact of the switch section 112 is switched, and the pressing piece 121 of the actuator 102 is
a, 3a and locked [FIG. 2 (b)]. Then, the cam follower pin 6 is
At the time when it is located at the other end of 2, as shown in FIG.
The cam follower pin 6 is fixed to the other slope 8 b of the stop member 8.
Movement is regulated. Thereby, the actuator 10
Even if a force acts on the actuator 2 in the disengagement direction, the actuator 102 is prevented from disengaging as long as the acting force does not overcome the elastic force of the compression coil spring 9 and displaces the stop member 8. Therefore, by appropriately selecting the elastic force of the compression coil spring 9, if the force acting on the door 103 is a reaction force at the time of closing the door or a force of about the vibration of the industrial machine inside the room, the actuator The operation unit 111 can be provided with a simple lock function such that the detachment of the 102 can be prevented. However, the simple lock function is provided to the door 10 by the workers.
It is assumed that when the user attempts to open 3, the operation force can be easily released. In the above embodiment, the stopper members 8 are arranged at both ends of the cam follower pin 6, but the stopper members 8 may be arranged only at one of the end portions. Thus, the same operational effects as those described above can be achieved. FIG. 5 is a central longitudinal sectional view showing the structure of another embodiment of the present invention. What is notable in this example is that the stopper member and the elastic body are integrally formed by bending the leaf spring. That is, the two surfaces 58a and 58b inclined with respect to the direction in which the guide hole 12 of the cam follower pin 6 extends.
And the elastic piece 59 and the fixed piece 60 connected to the ridge 58 are integrally formed by bending a leaf spring. The ridge 58 corresponding to the stop member is formed by bending of the elastic piece 59. It is configured to move in a direction approaching and separating from the guide hole 12 along a plane orthogonal to the camshaft 4. Also in this example, when the cam follower pin 6 moves along the guide hole 12 from the position shown in FIG. 5A, the slope 58a of the peak 58 is pushed downward and displaced downward. When the pin 6 reaches the other end of the guide hole 12 after the pin 6 has passed over the top, as shown in FIG.
The movement of the cam follower pin 6 is restricted by the other slope 58b of the cam 8. As described above, according to the safety switch of the present invention, the plate cam that rotates in accordance with the entry of the actuator into the operation unit, and the switch unit that rotates in accordance with the rotation of the plate cam. A cam follower pin that moves the operating rod is provided, and a stop member that restricts the movement of the pin when it is retracted with a predetermined elastic force is provided. With the action force, the actuator does not come off, and even if a safety switch is used as a substitute for a safety plug, the actuator does not come off due to the weight of a chain or the like. Inconveniences such as the supply being stopped can be solved.

[Brief description of the drawings] FIG. 1 is a horizontal sectional view showing the structure of an embodiment of the present invention. FIG. 2 is a central longitudinal sectional view of the embodiment. FIG. 3 is a sectional view taken along the line AA of FIG. 1; FIG. 4 is a diagram illustrating the operation of the embodiment of the present invention. FIG. 5 is a central longitudinal sectional view showing the structure of another embodiment of the present invention. FIG. 6 is a perspective view showing an example of a use state of the safety switch. [Explanation of symbols] 1,2,3 plate cam 1a, 3a recess 1c, 3c Groove cam 4 Camshaft 6 Cam follower pin 7 Operation rod 8 Stopping member 8a, 8b Mountain slope 9 Compression coil spring 11 Support frame 12 Guide groove 101 Switch body 111 Operation unit 112 Switch section 102 Actuator 121 pressing piece 122,123 Supporting piece 103 door

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) F16P 3/08 H01H 3/16

Claims (1)

(1) A switch body is mounted around a doorway of a room or the like in which an industrial machine is installed, and an actuator fixed to the door of the doorway opens and closes the door and operates the switch body. In the safety switch having a structure in which the connection rod is switched by moving the operation rod of the switch portion in response to the movement, the actuator has an insertion portion into the operation portion, which supports the pressing piece at the tip and both ends thereof. The operating portion is configured to rotate in response to the entry of the actuator, and to form a plate cam having a concave portion formed on an outer peripheral surface thereof into which a pressing piece of the actuator fits, and both ends of the cam shaft. A supporting frame to be supported, a groove cam formed on the plate cam, and a portion of the support frame opposed to the groove cam formed along the moving direction of the operation rod. And guide holes, are fitted in the holes and the grooved cam,
Both ends face the outside of the side of the support frame, respectively, and a pin to which the end of the operation rod is connected, and a stop member located on at least one side of both ends of the pin are provided, and the stop member is A member formed with a crest having two surfaces inclined with respect to the direction in which the guide hole extends, and a position where the slope of the crest intersects the guide hole along a plane orthogonal to the pins and A safety switch, which is disposed so as to be displaceable between a position not interfering with the hole and is pressed toward the guide hole by an elastic body.