Safety switch

Abstract

To suppress the disturbance of a worker.SOLUTION: A safety switch (100) includes a switch body (104) including an electromagnet (130), and an actuator (104) to be attracted to the electromagnet (130), the switch body (104) having a drive control part and a safety control part for controlling the safety switch (100), the drive control part and the safety control part being surrounded by a casing (Hg), the casing (Hg) being arranged on the back side of the electromagnet (130) of the switch body (102). By the casing (Hg), a storage part (132) is formed to store the drive control part and the safety control part.SELECTED DRAWING: Figure 8

Description

[Technical field]

[0001] The present invention relates to a safety switch. [Background technology]

[0002] In an environment in which an apparatus operates, if a human body can freely come into contact with the operating apparatus, there is a risk that the apparatus may cause harm to the human body. In an environment in which an apparatus operates, in order to prevent the operating apparatus from causing harm to the human body, in other words, to realize a safe state, the operating area in which the apparatus operates is partitioned by a protective fence or a partition panel. One method of realizing a safe state by partitioning the operating area is to partition the operating area with fixed parts such as a protective fence to prevent the human body from entering the operating area, that is, to isolate the operating area from an area in which the human body is present. Another method is to construct a partition system that partitions the operating area and can restrict the operation of the apparatus. In the partition system, the operating area is partitioned by fixed parts such as a protective fence, and then a partition is provided in which an opening and a movable part that opens and closes the opening are installed in a part of the partition so that a worker can access the operating area, that is, a partition that allows a worker to enter the operating area is provided. In the compartment system, a control system is constructed to monitor the moving parts and control the devices operating in the operating area according to the monitoring results so as not to cause harm to the human body. In such a compartment system, a safety switch that monitors the opening and closing of the moving parts is installed in the area of ​​the opening where the moving parts are installed.

[0003] The safety switch is composed of a switch body arranged in the fixed part of the compartment, and an actuator arranged in the opening and closing door that constitutes the movable part of the compartment. The safety switch detects and outputs when the door, which is a movable part, is opened, as a function for maintaining the operating area in a safe state, and the entire compartment system controls the devices in the operating area to a state where no harm is caused to the human body according to the output from the safety switch. By configuring the system to stop the devices in the operating area or slow down the operating speed of the devices according to the output from the safety switch, for example, safety measures are taken for the environment in which the devices are operating.

[0004] As a type of safety switch, a safety switch with a lock pin mechanism is disclosed in Patent Document 1. The safety switch with a lock pin mechanism has an actuator bolt installed in a fixed portion of the compartment and a switch body installed in the door, and a lock pin is provided in the switch body. The actuator bolt and the switch body are arranged in relative positions facing each other when the door is closed. In the lock pin mechanism, the lock pin mechanically engages with the actuator bolt to form a locked state in which the actuator bolt and the lock pin are physically integrated. The safety switch with a lock pin mechanism is provided with a detection mechanism so that the safety switch with a lock pin mechanism can detect that it is in a locked state, and outputs an indication that it is not in a locked state at least when it is not in a locked state. By closing the door and locking the lock pin mechanism, the open / close door in a closed state is fixed in a state integrated with the fixed portion of the compartment. Conversely, by disengaging the lock pin from the actuator bolt, an unlocked state is formed, and the door can be opened.

[0005] Patent Document 2 discloses a safety switch with an electromagnetic locking mechanism, which is another type of safety switch. That is, the safety switch with an electromagnetic locking mechanism has an electromagnet and an actuator magnetized member that is attracted to the electromagnet. The actuator magnetized member is installed on the door that constitutes the movable part, while a switch body including the electromagnet is installed on a fixed part of the compartment such as a safety fence. The door lock state is established by driving the electromagnet to cause it to attract the actuator magnetized member. The safety switch is equipped with a display unit. The display unit displays the safety state of the operating area.

[0006] The safety switch with an electromagnetic locking mechanism in Patent Document 2 has a locking lever that is operated by the operator to prevent the operator from mistaking the "door closed" signal for the operating area to be safe, i.e., that there is no one in the operating area, and restarting the machine. This locking lever allows the operator to confirm that the operating area is kept safe in some way before operating the locking lever, and from that point on, it can be determined that it is safe as long as the "door closed" signal is being output. Once the door is opened, it becomes unclear whether it is safe even if the "door closed" signal is output thereafter.

[0007] Patent Document 2 also discloses a module composed of a monitoring sensor and a monitoring actuator for monitoring the opening and closing of a door. The monitoring actuator is installed on the door that opens and closes, while the monitoring sensor is installed on a fixed part of the compartment. As the door, which is a movable part, opens and closes, the monitoring actuator moves away from or approaches the monitoring sensor, and the monitoring sensor generates a door signal including a first status signal indicating that "the door is open" or a second status signal indicating that "the door is closed." [Prior art documents] [Patent documents]

[0008] [Patent Document 1] JP 2019-183541 A [Patent Document 2] Special Publication No. 2016-510382 Summary of the Invention [Problem to be solved by the invention]

[0009] As described above, in safety measures using a safety switch, the safety switch is installed near an opening through which a human body mainly enters and exits for work or other purposes. For this reason, the safety switch is an obstacle to workers. For example, when the safety switch is arranged on a partition fixing part outside the working area, there is an advantage that the display part of the safety switch can be easily confirmed by a worker outside the working area, but the safety switch protrudes from the partition fixing part to the outside regardless of the position of the opening and closing door, which is an obstacle to workers. Conversely, when the safety switch is arranged inside the working area, the reduction in workability caused by the safety switch protruding from the partition fixing part to the outside is eliminated, but the workability when the opening and closing door is opened is reduced. More specifically, when the safety switch is arranged inside the working area, when the door as a movable part of the partition is closed, the switch main body needs to be arranged near the actuator arranged on the opening and closing door. For this reason, the switch main body is arranged at a position that occupies an area that functions as a door opening when the door is opened. For this reason, the safety switch including the switch main body narrows the area of ​​the door opening where the movable part is located, and so when the movable part is opened, i.e., when work is performed through the door opening, the safety switch may get in the way. Also, if the safety switch is located inside the operating area, and the safety switch is located in the opening area, for example, if the area of ​​the opening door that corresponds to the opening is made of a transparent or semi-transparent material, there is a risk that the switch main body may be difficult for the worker to see when looking into the operating area from outside.

[0010] An object of the present invention is to provide a safety switch with an electromagnetic locking mechanism that can reduce interference with an operator. [Means for solving the problem]

[0011] According to the present invention, the above technical problem is solved as follows: A safety switch in which an actuator having a magnetized member on which an attracted surface is formed is disposed so as to be movable relative to a switch body, a detection unit that detects whether the actuator is within a predetermined range with respect to the switch body; an electromagnet having an attracting surface formed on a front side thereof corresponding to an attracting surface of the actuator; a lock input portion for receiving a lock signal for locking the relative movement of the actuator; a drive control unit that drives the electromagnet so that the attracting surface and the attracted surface are attracted to each other based on the lock signal received by the lock input unit; a safety control unit that generates a safety signal based on the detection by the detection unit; This can be achieved by providing a safety switch including a housing that forms a housing portion for housing the drive control portion and the safety control portion on the rear side of the electromagnet.

[0012] According to the present invention, since the board housing portion is located on the opposite side of the electromagnet from the attraction surface, the presence of the switch body, which narrows the area of ​​the opening where the compartment movable part is installed, can be reduced. Also, the switch body looks small when viewed from outside the compartment, i.e., from the outside. In other words, since the board housing portion of the switch body located inside the operating area is located in a position where the attraction surface is away from the attraction surface when viewed from the outside, the switch body looks small when an operator looks into the operating area from the outside.

[0013] The effects and other objects of the present invention will become apparent from the following detailed description of preferred embodiments of the present invention. [Brief description of the drawings]

[0014] [Figure 1] 1 is a front view of a safety fence and an opening / closing door equipped with a safety switch according to an embodiment of the present invention. The safety switch is configured with an electromagnetic lock mechanism. [Diagram 2] FIG. 2 is a cross-sectional view taken along line II-II in FIG. [Diagram 3]1 is a diagram for explaining a box-shaped device to which the present invention can be applied. [Figure 4] FIG. 2 is a perspective view of an actuator which is one component of the safety switch of the embodiment. [Diagram 5] 1 is a perspective view of a switch body, which is another component of the safety switch of the embodiment, as viewed obliquely from the front and obliquely from above. FIG. [Figure 6] FIG. 6 is a front view of the switch body shown in FIG. 5. [Figure 7] FIG. 6 is a side view of the switch body shown in FIG. 5. [Figure 8] 6 is a longitudinal sectional view taken along the center line of the switch body shown in FIG. 5. [Figure 9] FIG. 6 is a diagram showing the switch main body shown in FIG. 5 with the housing removed. [Figure 10] 6 is an explanatory diagram showing the electromagnet and the housing of the switch body shown in FIG. 5 separated from each other and viewed obliquely from behind. [Figure 11] This is an oblique view of the door opening frame of the protective fence and the safety switch installed in the door frame of the opening and closing door, viewed from the outside of the opening and closing door. [Figure 12] 11A and 11B are diagrams for explaining the effects of the arrangement of the display unit of the safety switch according to the embodiment. [Figure 13] FIG. 4 is a block diagram for explaining an electrical configuration of a switch body included in the embodiment. [Figure 14] FIG. 14 is a functional block diagram of the first MCU shown in FIG. 13. [Figure 15] FIG. 14 is a functional block diagram of the second MCU shown in FIG. 13. [Figure 16] FIG. 11 is a diagram for specifically explaining a display mode of a display. [Figure 17] FIG. 4 is a diagram for explaining a preferable arrangement position of the display unit. [Figure 18] 10A and 10B are diagrams for explaining a method for determining whether or not an iron piece is in close contact with an electromagnet. [Figure 19] FIG. 2 is a vertical cross-sectional view of an actuator of the safety switch according to the embodiment. [Figure 20]20A and 20B are diagrams relating to a compression coil spring included in the actuator shown in FIG. 19, where (I) is a plan view, (II) is a side view of the compression coil spring in an unloaded state, and (III) is a side view of the compression coil spring in a crushed state by applying a compressive force. [Figure 21] FIG. 11 is a diagram for explaining the process of aligning the orientation of the attracting surface and the orientation of the attracted surface in the safety switch of the embodiment, in which (I) shows the standby state of the actuator when the door is open, (II) shows the state in which the attracted surface moves forward toward the attracting surface under the attractive force of the permanent magnet when the actuator approaches the electromagnet during the process of closing the door, and (III) shows the state in which the attracted surface is in close contact with the attracting surface under the attractive force of the permanent magnet. [Figure 22] FIG. 21 is a diagram for explaining the state changes of the actuator shown in FIG. 20, in which (I) is a diagram in which the attracted surface, i.e., the iron piece, is positioned in the retracted position, (II) is a diagram in which the iron piece is positioned in the advanced position, and (III) is a diagram in which the iron piece is in the advanced position and tilted to establish a parallel state with the attracting surface of the electromagnet. [Diagram 23] This figure is for explaining the technical significance of arranging the sensor side coil in a location where magnetic flux leakage is suppressed by providing a protrusion that protrudes radially outward from a part of the cylindrical outer surface of the yoke portion in a switch body included in an embodiment, and is a bottom view of the switch body as seen from the direction looking into the attraction surface. [Figure 24] A cross-sectional view of the sensor body taken along line XXIV-XXIV in Figure 23. / / Please explain the gap Gp in the same way as other dimensions. I don't understand what it means even if it is illustrated in figures other than Figure 24 (for example, Figures 5, 6, and 23). [Diagram 25] FIG. 13 is a diagram for explaining how, in a switch body of a comparative example, the sensor side coil is adversely affected by magnetic flux leaking from a cylindrical switch body having a circular attraction surface, and is a bottom view of the switch body of the comparative example as viewed from a direction looking into the attraction surface. [Figure 26] 26 is a cross-sectional view of a sensor main body of a comparative example taken along line XXVI-XXVI in FIG. 25. [Figure 27]1 is a schematic diagram showing an installation structure of a switch body to be installed in a door opening frame. FIG. [Figure 28] FIG. 28 is a schematic diagram corresponding to FIG. 27 and illustrating a first modified example of the installation structure of the switch body. [Figure 29] FIG. 28 is a schematic diagram corresponding to FIG. 27 and illustrating a second modified example of the installation structure of the switch body. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS EXAMPLES

[0015] A preferred embodiment of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is an explanatory diagram of an opening / closing door and a protective fence in which a safety switch with an electromagnetic lock mechanism of the embodiment is installed as a partition system 1. FIG. 2 is a cross-sectional view taken along line II-II in FIG. 1. In the figure, reference symbol PF indicates a protective fence, and reference symbol PD indicates an opening / closing door. FIG. 1 is an explanatory diagram of the partition system 1 as seen from outside the operating area S partitioned by the partition system 1. The partition system 1 is composed of a protective fence PF as a fixed part of the partition, a door PD constituting a movable part movable relative to the fixed part of the partition, and a safety switch 100. The partition system 1 maintains the operating area S in a safe state by restricting the operation of the device inside the operating area S based on the safety-related output output by the safety switch 100. In this embodiment, the safety switch 100 is disposed within the operating area S. The protective fence PF constitutes a fixed part of the partition system 1 that partitions the operating area S in which the device operates. The opening in which the door PD constituting the movable part relative to the fixed part of the partition is installed is formed by a door opening frame 2. 1, a plurality of hinges 4 spaced apart vertically are provided on one side of the door PD constituting the movable part, and the door PD is attached to a vertical frame part 2a of a door opening frame 2 via the plurality of hinges 4. In other words, the door PD is a single-leaf door.

[0016] 1 and 2, the door PD is composed of a door frame 6 and a transparent board 8 surrounded by the door frame 6. The door PD has the above-mentioned hinge 4 attached to one side and a door operating unit 10 attached to the other side (FIG. 1). By operating the door operating unit 10, a door latch (not shown) that engages with and disengages from the door opening frame 2 is released, allowing the door PD to be opened.

[0017] FIG. 2 shows the state in which the door PD is closed, and the door frame 6 constituting the door PD is in contact with the door stopper 110 and positioned. In FIG. 2, the operating area S partitioned by the safety fence PF and the opening and closing door PD is an area located to the right of the safety fence PF and the door PD on the paper surface of FIG. 2. The safety switch 100 is disposed on the operating area S side in relation to the door PD in the closed state. When the door PD is closed, the safety switch 100 is disposed so as to be located on the operating area S side with respect to the door PD, so that the safety switch 100 is disposed inside the operating area S. Referring to FIG. 2, the safety switch 100 is constituted by a switch body 102 and an actuator 104. The switch body 102 is fixed to the surface of the upper horizontal frame part 2b of the door opening frame 2 on the operating area S side via a first bracket 106. The switch body 102 is provided with an electromagnet 130 having an attraction surface 130a. When the door PD is closed, the switch body 102 is installed in the door opening frame so that the suction surface 130a faces the door PD, in other words, faces the outside of the operating area S. Note that, in Fig. 2, arrows X, Y, and Z indicating three mutually orthogonal directions are illustrated, which correspond to the arrangement posture of the safety switch 100 as described later.

[0018] As will be described later with reference to Figures 7 and the like, the switch body 102 of the safety switch 100 of the embodiment includes an electromagnet 130 (Figure 8) and a board accommodating portion 132, and the boards Cb(1) and Cb(2) (Figures 8 and 9) are accommodated in the board accommodating portion 132.

[0019] On the other hand, the actuator 104 is disposed on the surface of the door frame 6 on the operating area S side, and specifically, is fixed to the upper frame portion 6a of the door frame 6 via a second bracket 108 (FIG. 2). The door opening frame 2 and the door frame 6 both have a closed rectangular cross section, which is a well-known structure, but as a modified example, they may have a U-shaped or L-shaped cross section.

[0020] The door PD is related to the opening and closing door described in Patent Document 2. On the other hand, Fig. 3 shows a box-shaped device 500 that houses a work system. In Fig. 3, three devices 500 are arranged side by side. A double-door opening and closing door 506 as an example of a door PD is attached to the box 502 of each device 500 so that an operator can manually access a device 504 installed therein. In relation to the opening and closing door 506, a safety switch 100 can be installed in the box-shaped device 500.

[0021] Hereinafter, an embodiment of the present invention will be described based on an embodiment applied to the door PD disclosed in FIG. 1 and FIG. 2 as a typical example. FIG. 4 is a substantial front view of the actuator 104 included in the safety switch 100, and is a diagram for explaining the front shape of the actuator 104. The actuator 104 is mainly composed of an iron piece 120 which is a magnetized member, and includes a plastic molded part 122, an actuator communication unit 124, and a mounting bracket 126. The iron piece 120 is circular when viewed from the front, and has an attracting surface 130a and an attracting surface 120a on the front. The diameter of the iron piece 120 is indicated by reference symbol D1. The iron piece 120 is attached to the plastic molded part 122. The periphery of the iron piece 120 is covered with the plastic molded part 122, and the actuator communication unit 124 is arranged in a manner covered and hidden by the plastic molded part 122. The mounting bracket 126 is provided on the opposite side of the iron piece 120 with respect to the plastic molded product 122, and has a shape extending left and right on the paper surface of FIG. 4. The mounting bracket 126 has a pair of mounting holes through which screws for fastening the mounting bracket are inserted, in a portion visible from the front of the actuator 104. The pair of mounting brackets 126 are fastened to the second bracket 108, and the actuator 104 is fixed to the door PD via the second bracket 108 (FIG. 2). With the door PD in a closed state, the relative positional relationship between the actuator 104 and the switch body 102 is such that the actuator 104 is located on the surface of the door frame 6 on the operating area S side. That is, the actuator 104 is installed on the door frame 6 so that the attracted surface 120a of the iron piece 120 faces the operating area S when the door PD is in a closed state. On the other hand, the switch body 102 is located inside the operating area S. In this embodiment, the actuator 104 is fixed to the door PD via the second bracket 108, but the mounting bracket 126 may be directly fastened to the door frame 6 and the actuator 104 may be fixed to the door PD.

[0022] An example of the arrangement when the actuator 104 is fixed to the door PD will be specifically described based on the example of the arrangement shown in FIG. 2. The actuator 104 is fixed to the upper frame portion 6a of the door frame 6 as described above. In this embodiment, the pair of mounting brackets 126 of the actuator 104 are fixed so that the mounting holes are aligned in the horizontal direction, that is, in the longitudinal direction of the upper frame portion 6a. In this installation example, reference symbol Ha in FIG. 4 indicates the height of the iron piece 120 that is circular when viewed from the front and is included in the actuator 104. In the installation example shown in FIG. 2, the actuator 104 is fixed to the door frame 6 in a state where the direction of the height Ha is aligned with the direction of the width Wdf of the upper frame 6a. The height Ha of the actuator 104 is equal to or smaller than the average width Wdf of the door frame 6 with a rectangular cross section (FIG. 2). The actuator 104 installed on the door frame 6 may have a part protruding to the inside of the door frame 6, that is, to the portion of the transparent board 8, but it is preferable that this protrusion amount be as small as possible. This can reduce the interference caused by the actuator 104 during work.

[0023] In the safety switch 100 of this embodiment, the electromagnet 130 of the switch body 102 and the iron piece 120 of the actuator 104 function as an electromagnetic locking mechanism. As described above, the electromagnetic locking mechanism of the safety switch has historically been developed following the technical idea of ​​the lock pin mechanism. The design concept of the safety switch 100 with electromagnetic locking mechanism of the embodiment will be described. In general terms, when considering the role of the safety switch, the original requirement of maintaining a safe environment in the operating area where the operating device is placed is realized by the function of detecting the opening and closing of the door, and the role required of the door lock function is to keep the device operating in the operating area. Therefore, it can be said that the door lock function is sufficient if it can keep the device operating in the operating area. In other words, the basic requirement of the door lock function of the safety switch is to prevent the opening and closing door from being inadvertently opened while the device is operating. This is because if the opening and closing door is inadvertently opened, the operation of the device in the operating area is restricted by the function of the safety switch for maintaining the operating area in a safe environment. In other words, the essential role of the door lock function required of a safety switch is to prevent the operation of the equipment in the operating area S (Figure 2) or box 502 (Figure 3) from being interrupted by the inadvertent opening of the door PD, 506.

[0024] Conventionally, the door lock function of the safety switch is designed to contribute to maintaining the operating area in a safe environment. For this reason, the electromagnetic lock mechanism also uses an electromagnet with a strong magnetic force that prevents the door from being opened even with a relatively strong operating force. However, from the viewpoint that the role of the door lock function is not to maintain a safe environment but to keep the device operating, the magnetic force of the electromagnet used in the safety switch with an electromagnetic lock mechanism may be the same as that of the conventional one, but may be weaker than that. When an operator performs an operation to open the door PD, the operating force required to open the door PD is at least required to ask the operator, "You are now operating to open the door PD. Is this as you intend?" Inadvertent opening of the door can be prevented. If a certain operating force that can confirm the operator's intention to open the door PD is required by the electromagnet, inadvertent opening of the door PD can be prevented without requiring any more operating force.

[0025] Therefore, optionally, the magnetic force of the electromagnet 130 may be made weaker than in the past. For example, in the case where the door PD has an operating part such as a doorknob, the door latch is released when an operating force for rotating the doorknob is applied to the doorknob, but the electromagnet 130 is used with a magnetic force at least stronger than the operating force for releasing the door latch. This can deter the worker from opening the door PD, and can prevent the door PD from being opened unintentionally. Also, it can be avoided that the operation of the device is unexpectedly interrupted due to the door PD being opened unintentionally.

[0026] 5, the switch body 102 has a screw hole 130c as a mounting portion for fixing the switch body 102 to the door opening frame 2, which is a fixed portion of the compartment system 1. More specifically, the electromagnet 130 has a protruding portion 130b that protrudes from the center of the attraction surface 130a in a direction toward the outside, and the screw hole 130c is provided in the protruding portion 130b. In the arrangement example shown in FIG. 2, the switch body 102 is fixed to the upper horizontal frame portion 2b of the door opening frame 2 via the first bracket 106 having an L-shaped cross section (FIG. 2). In the arrangement example shown in FIG. 2, the protruding portion 130b is located protruding from the upper portion of the electromagnet 130, and the flat top surface of the protruding portion 130b constitutes a mounting surface, and the screw hole 130c is provided in the mounting surface. This mounting surface may be formed on the side surface of the electromagnet 130.

[0027] For example, in FIG. 5, arrows X, Y, and Z are shown indicating three mutually orthogonal directions. The directions indicated by the arrows X, Y, and Z correspond to the arrangement posture of the safety switch 100, and the directions indicated by the arrows X, Y, and Z are called the X-axis direction, the Y-axis direction, and the Z-axis direction, respectively. The Y-axis direction indicates the normal direction of the attraction surface 130a of the electromagnet 130. The Z-axis direction indicates the direction perpendicular to the Y-axis direction, parallel to the attraction surface 130a, and in which the protrusion 130b protrudes from the center of the attraction surface 130a. The X-axis direction indicates the direction parallel to the attraction surface 130a and perpendicular to the Z-axis. As shown in FIG. 2, the safety switch 100 of this embodiment is arranged so that the attraction surface 130a faces the door PD in the closed state, so that the normal direction of the door PD in the closed state coincides with the Y-axis direction. Moreover, the safety switch 100 of this embodiment is disposed so that the direction in which the protrusion 130b protrudes from the center of the suction surface 130a is perpendicular to the extension direction of the upper frame portion 6a of the door PD in the closed state and the extension direction of the upper horizontal frame portion 2b of the door opening frame 2. For this reason, in this embodiment, the extension direction of the upper frame portion 6a and the extension direction of the upper horizontal frame portion 2b coincide with the X-axis direction, and the direction toward the operating area S side with respect to the door PD, i.e., the depth direction of the operating area S, coincides with the Y-axis direction. In the following description, in the Y-axis direction, the direction from the door PD in the closed state toward the suction surface 130a may be called "rear" and the opposite direction may be called "forward," and in the Z-axis direction, the direction from the suction surface 130a toward the protrusion 130b may be called "upward," and the opposite direction may be called "downward."

[0028] 5 to 10 are diagrams relating to the switch body 102. FIG. 5 is a perspective view of the switch body 102. FIG. 6 is a front view. FIG. 7 is a side view. As can be seen most clearly from FIG. 7, the switch body 102 has a generally cylindrical shape extending in the Y-axis direction. The switch body 102 has an electromagnet 130 including an attraction surface 130a that constitutes one end face on the front side in the Y-axis direction. The attraction surface 130a constitutes the main part of the front end face of the switch body 102. Specifically, one end face of the switch body 102 is constituted by the attraction surface 130a. As described above, the attraction surface 130a faces the door PD when the door PD is closed.

[0029] As shown in FIG. 5, the switch body 102 includes a housing Hg including a board housing portion 132 for housing a board, and a display unit 142 for displaying a safety-related output output from the safety switch 100 based on the detection result of the actuator 104. A connection portion is formed on the back side of the electromagnet 130, that is, on the opposite side of the attraction surface 130a in the Y-axis direction, and the electromagnet 130 and the housing Hg are connected by the connection portion. The board housing portion 132 is located on the opposite side of the attraction surface 130a of the electromagnet 130 in the Y-axis direction. In other words, the board housing portion 132 is located behind the electromagnet 130 or on the rear side of the electromagnet 130. For this reason, the dimensions of the entire switch body 102 in the X-axis direction and the Z-axis direction are unlikely to be large compared to the dimensions of the electromagnet 130 in the X-axis direction and the Z-axis direction. In addition, the display unit 142 is located on the opposite side of the attraction surface 130a of the electromagnet 130 in the Y-axis direction in the housing Hg. The switch body 102 has a shape in which the dimension in the Y-axis direction is larger than both the dimension in the X-axis direction and the dimension in the Z-axis direction. Therefore, when viewed from the front, the area that the switch body 102 occupies in the opening formed in the door opening frame 2 tends to be smaller than other switch bodies that require a similar capacity.

[0030] FIG. 6 is a front view of the switch body 102 as viewed from the front. The normal direction to the paper surface of FIG. 6 is parallel to the Y-axis direction. As described above, the board accommodating portion 132 is located behind the electromagnet 130. Therefore, when the switch body 102 is viewed from the front, as can be seen from FIG. 6, most of the housing Hg having the board accommodating portion 132 is hidden by the electromagnet 130. Therefore, the increase in the area occupied by the switch body 102 as viewed from the front due to the provision of the housing Hg is suppressed. In this embodiment, the ratio of the area occupied by the housing Hg to the area occupied by the attraction surface 130a as viewed from the front is small.

[0031] As shown in FIG. 6, the area occupied by the housing Hg when viewed from the front is larger on the side where the screw hole 130c is provided with respect to the center of the adsorption surface 130a than on the side opposite to the side where the screw hole 130c is provided with respect to the center of the adsorption surface 130a. In other words, most of the housing Hg is located above the center of the adsorption surface 130a when viewed from the front. When the switch body 102 is fixed by the screw hole 130c, a dead space is generated between the maximum dimension part in the X-axis direction of the adsorption surface 130a and the door opening frame 2 to which the switch body 102 is attached. By utilizing the dead space as the area where the housing Hg is provided, the workability through the door opening frame 2 is not likely to decrease. Therefore, by configuring the housing Hg so that the area occupied by the housing Hg when viewed from the front is larger on the side where the screw hole 130c is provided with respect to the center of the adsorption surface 130a, the workability through the door opening frame 2 in which the switch body 102 is arranged is ensured.

[0032] FIG. 7 is a side view of the switch body 102. The switch body 102 has the board accommodating portion 132 on the opposite side to the adsorption surface 130a with respect to the electromagnet 130 (FIG. 8). As described above, reference symbol Hg indicates the housing of the board accommodating portion 132. The connector connecting portion 144 is provided on the side of the board accommodating portion 132 opposite to the side where the adsorption surface 130a is located in the Y-axis direction, i.e., on the rear end surface 134 (FIGS. 7 and 8). The rear end surface 134 is also the end surface of the switch body 102 opposite to the side where the adsorption surface 130a is located. The connector connecting portion 144 extends in a direction away from the adsorption surface 130 along the Y-axis direction. By providing the connector connecting portion 144 on the end surface 134 of the board accommodating portion 132, it is not necessary to position the cable connected to the connector connecting portion 144 around the switch body 102. In addition, since the connector connecting portion 144 is disposed on the rear end surface 134 of the board accommodating portion 132, at least a portion of the cable connected to the connector connecting portion 144 near the connector connecting portion 144 is located behind the switch body 102. This reduces the risk that the visibility of the display unit 142 from the front will be reduced by the cable. In addition, by routing the cable connected to the connector connecting portion 144 behind the switch body 102 or above where the screw holes 130c are located, it is possible to route the cable so that it is not located near the opening formed by the door opening frame 2, and therefore the ease of work through the door opening frame 2 is unlikely to be reduced.

[0033] Fig. 8 is a vertical cross-sectional view of the switch body 102 cut along the Z-axis direction. Fig. 9 is a diagram for explaining the arrangement of two boards Cb(1) and Cb(2) arranged in the board housing portion 132. Fig. 9 is a perspective view of the switch body 102 seen obliquely from the front with the housing Hg removed to expose the housing portion 132. Fig. 10 is an exploded perspective view of the electromagnet 130 and the housing Hg, and is a view of the switch body 102 seen from the rear.

[0034] 9, although not particularly limited thereto, a part of the yoke portion Yk (FIG. 24) of the electromagnet 130 described later is formed in a raised shape, and the raised shape portion constitutes the protruding portion 130b. In the arrangement example shown in FIG. 2, the protruding portion 130b is attached so as to be located on the top, but it is also possible to attach the switch body 102 so that the mounting portion 103b is located to the side.

[0035] As can be seen from Figures 5 and 8, the protrusion 130b has two screw holes 130c spaced apart in the front-to-back, i.e., Y-axis direction, and is fixed to the first bracket 106, which has an L-shaped cross section, using screws Sc that screw into the two screw holes 130c (Figure 2).

[0036] 8 and 9, the substrate accommodating section 132 accommodates the first substrate Cb(1) and the second substrate Cb(2), which are disposed perpendicular to each other. Specifically, the first substrate Cb(1) is disposed with its plate surface aligned along the Y-axis direction, and the second substrate Cb(2) is disposed with its plate surface aligned along the Z-axis direction. The second substrate Cb(2) is disposed at the rear end of the first substrate Cb(1) in the state shown in FIG. 8, preferably in a state where it hangs down from the first substrate Cb(1).

[0037] As described above, the switch body 102 has at least the display unit 142 (FIGS. 2, 5, and 7) that displays a safety-related output output by the switch body 102. The display unit 142 is provided at a position that is visible from the opposite side of the surface of the switch body 102 where the screw hole 130c serving as the mounting portion is located. In other words, the display unit 142 is provided at a position that is visible from the side where the mounting surface formed by the top surface of the protrusion 130b does not exist. When the switch body 102 is fixed to the door opening frame 2, the screw hole 130c is arranged and fixed so as to face outward from the opening formed in the door opening frame 2. Therefore, the surface opposite to the surface where the screw hole 130c is provided is arranged so as to face the inside of the opening. In the example of FIG. 2, since the switch body 102 is fixed to the upper side horizontal frame portion 2b of the door opening frame 2, the direction from the opening to the outside is upward. And, since the inside of the opening of the upper side horizontal frame portion 2b is downward, the surface on which the display unit 142 is provided faces downward. In this embodiment, the switch body 102 is fixed to the upper horizontal frame portion 2b of the door opening frame 2 that forms the opening, but when the switch body 102 is fixed to the frame portion of the door opening frame 2 opposite to the side where the hinge 4 is provided (the frame portion on the right side of the paper in FIG. 1), the display unit 142 is located on the left side of the paper in FIG. 1. By providing the display unit 142 on the opposite side to the screw hole 130c in this way, the display unit 142 faces the opposite side of the frame portion of the door opening frame 2 to which the switch body 102 is attached, that is, the inside of the opening. When the operating area S is looked into from the outside of the door PD having the transparent board 8, the transparent board 8 is located inside the opening, so that the switch body 102 is visible from the inside of the opening. Therefore, by positioning the display unit 142 inside the opening when fixed to the door opening frame 2, the visibility of the display unit 142 is improved.

[0038] The second board Cb(2) is connected to the connector connection portion 144, and a plurality of indicator lights 150 (FIG. 8), specifically a plurality of LED elements, of different colors are mounted on the front lower portion of this second board Cb(2). The plurality of indicator lights (LED elements) 150 constitute the light source of the display unit 142. As is well known, the display unit 142, which is disposed on a surface that allows the switch body 102 installed in the operating area S to be viewed from the outside, has a function of displaying the operating state of the switch body 102 in identifiable colors.

[0039] 8, in the substrate housing portion 132, a limited illumination space Ls is formed by a first substrate Cb(1) whose plate surface extends along the front-rear, i.e., Y-axis direction, and a second substrate Cb(2) whose plate surface extends along the Z-axis direction. Then, light from the LEDs 150 mounted on the second substrate Cb(2) is emitted toward this limited illumination space Ls, and as a result, the light is displayed through a light-transmitting material that constitutes a part of the display portion 142 and also constitutes a part of the housing Hg of the substrate housing portion 132. Of course, the LEDs 150 that constitute the light source may be provided on the first substrate Cb(1).

[0040] The visibility of the display unit 142 through the door PD will be described with reference to Fig. 11 and Fig. 12. Fig. 11 is a view of the switch main body 102 seen from outside through the door PD. Fig. 12 is a schematic diagram created to explain the visibility of the display unit 142. In the figure, reference symbol Ey denotes the eye of the operator.

[0041] In FIG. 12, reference numeral 142-1 denotes a display unit located proximal to the adsorption surface 130a of the switch body 102. That is, the distance D-1 in the Y-axis direction between the adsorption surface 130a and the display unit 142-1 is relatively small. Reference numeral 142-2 denotes a display unit located distal to the adsorption surface 130e. The distance D-2 in the Y-axis direction between the adsorption surface 130a and the display unit 142-2 is relatively large. As can be seen from FIG. 12, although the display unit 142 is optional, it is understood that the visibility of the display unit 142 when viewed from the outside through the door PD is better when the display unit 142 is located distal to the adsorption surface 130a rather than proximal to the adsorption surface 130a. Preferably, the display unit 142 is located rearward of the intermediate line Imd that is half the length of the total length L (FIG. 5) in the Y-axis direction of the switch body 102. In other words, it is preferable to place the display unit 142 at a position farther away from the adsorption surface 130a in the Y-axis direction than the intermediate line Imd.

[0042] As can be seen from FIG. 7, the outer surface of the display unit 142 has a curved cross-sectional shape and extends to the middle part in the Z-axis direction on both sides of the switch body 102. This allows the display unit 142 to be viewed from three sides excluding the mounting surface. The display unit 142 also has a shape that is tapered toward the adsorption surface 130a in the Y-axis direction. In other words, the display unit 142 has a surface that is inclined toward the front, which is outside the operating area S on the door PD. By making the display unit 142 have a shape that is tapered toward the adsorption surface 130a, the display unit 142 becomes easier for the worker to see.

[0043] The housing Hg of the substrate accommodating portion 132 is made of a plastic molded product. A part of the housing Hg extends in the direction of the attraction surface 130a and has a shape that surrounds a part of the protruding portion 130b of the electromagnet 130. The housing Hg has a flat top surface that is substantially at the same height as the top surface of the protruding portion 130b (FIG. 5).

[0044] A control circuit that generates a drive signal for the electromagnet 130, a power supply circuit, a communication circuit with the actuator 104, and the like are mounted on the main body Cb (main body) of the first substrate Cb(1). On the other hand, an indicator light control circuit and the like are mounted on the second substrate Cb(2).

[0045] 9, in the substrate accommodating portion 132, the first substrate Cb(1) whose plate surface extends along the Y-axis direction has a pair of elongated substrate extensions Cb(1ex) extending in the Y-axis direction from a main body Cb (main body) located in the substrate accommodating portion 132 and mounting a control circuit and the like to the vicinity of the adsorption surface 130a. The pair of substrate extensions Cb(1ex) are located on both sides of the protrusion 130b in the X-axis direction. By positioning the pair of substrate extensions Cb(1ex) on both sides of the protrusion 130b, it is possible to prevent the presence of the substrate extensions Cb(1ex) from increasing the height dimension of the switch body 102 in the Z-axis direction. In addition, the substrate extensions Cb(1ex) are located at a position where a part of them overlaps with the electromagnet 130 when viewed in the Z-axis direction. Therefore, it is possible to reduce the increase in the dimensions of the switch body 102 in the Z-axis direction and the X-axis direction due to the presence of the substrate extensions Cb(1ex).

[0046] In the pair of board extensions Cb(1ex), a sensor side coil (antenna coil) 152 is mounted on the tip of one of the board extensions Cb(1ex) (FIG. 9). The sensor side coil 152 constitutes a detection unit that detects that the actuator 104 is within a predetermined range relative to the switch body 102. By mounting the sensor side coil 152 on the tip of one of the board extensions Cb(1ex), the sensor side coil 152 can be positioned close to the adsorption surface 130a in the Y-axis direction. As a result, the detection ability of the sensor side coil 152 can be improved. As is well known, the sensor side coil 152 is disposed in correspondence with the actuator communication unit 124 of the actuator 104 described above. At this time, in order for the sensor side coil 152 to detect the actuator communication unit 124, the sensor side coil 152 is covered with a housing Hg made of plastic rather than metal. For this reason, in the switch body 102, a part of the housing Hg exists on the surface facing the actuator 102 in addition to the adsorption surface 130a. In this embodiment, as described above, by disposing a part of the housing Hg in a dead space, it is possible to maintain the accessibility through the door opening frame 2 in which the switch main body 102 is disposed.

[0047] For example, in the process of closing the door PD, the iron piece 120 of the actuator 104 approaches the attracting surface 130a of the switch body 102 in conjunction with the closing operation of the door PD, as shown in FIG. 17, and then the iron piece 120 overlaps with the attracting surface 130a of the switch body 102. The iron piece 120 (attached surface 120a) is designed to have a diameter D1 (FIG. 4) larger than the diameter D2 of the attracting surface 130a. Based on the state in which the iron piece 120 overlaps with the switch body 102 in the normal state, that is, the normal state in which the center O1 of the iron piece 120 and the center O2 of the attracting surface 130a are aligned, the diameter D1 of the iron piece 120 is set relative to the diameter D2 of the attracting surface 130a so that the outer edge of the attracting surface 130a is located within the attracted surface 120a of the iron piece 120. As a result, even if the switch body 102 and / or the actuator 104 undergo a permissible relative displacement, the switch body 102 can fix the actuator 104 with a predetermined adsorptive force.

[0048] When the door PD is closed, that is, when the sensor side coil 152 detects the actuator communication unit, a safety-related output is output to a control device (e.g., a PLC) that controls devices installed in the operating area S (FIG. 2). An RFID detection circuit (not shown) associated with the sensor side coil 152 is mounted on the board extension Cb(1ex) of the first board Cb(1), and the electromagnet 130 is controlled based on a signal from the sensor side coil (antenna coil) 152.

[0049] 13 is a block diagram for explaining the electrical configuration of the switch main body 102. The control circuit 200 of the switch main body 102 includes a first MCU 202 and a second MCU 204. The first MCU 202 and the second MCU 204 monitor each other by communicating with each other.

[0050] The first MCU 202 is connected to a transmission circuit 206. The transmission circuit 206 is connected to a sensor side coil (antenna coil) 152. The sensor side coil 152 is connected to a reception circuit 208. The reception circuit 208 is connected to both the first MCU 202 and the second MCU 204. The sensor side coil 152 is controlled to exchange wireless signals with a coil included in the actuator communication unit 124. The first MCU 202 drives the sensor side coil 152 via the transmission circuit 206 to supply a wireless signal from the sensor side coil 152 to the actuator communication unit 124. The actuator communication unit 124 has at least a coil and a circuit, and is arranged so that the coil is located in a portion covered by the plastic molded product 122 as shown in FIG. 4. The first MCU 202 and the second MCU 204 receive a wireless signal from the actuator communication unit 124 via the sensor side coil 152 and the reception circuit 208. The RFID 152 has the sensor side coil 152 and a response circuit. The actuator communication unit 124 may be a wireless tag (RF-ID tag). The response circuit operates using as a power source an induced current generated in the sensor side coil 152. The response circuit demodulates the wireless signal received by the sensor side coil 152 to acquire information, and further transmits a wireless signal (response signal) via the sensor side coil 152.

[0051] 14 and 15, the measurement unit 210a of the first MCU 202 and the measurement unit 210b of the second MCU 204 each measure the strength of a wireless signal received from the actuator communication unit 124 via the sensor side coil 152 and the receiving circuit 208, and estimate a distance d (FIG. 17) between the switch body 102 and the actuator 104 based on the strength of the wireless signal. The safety determination circuit 214a of the first MCU 202 and the safety determination circuit 214b of the second MCU 204 each determine whether the estimated distance d is equal to or smaller than a threshold, that is, whether the actuator 104 is within a predetermined range with respect to the switch body 102. In other words, at least the sensor side coil 152, the receiving circuit 208, and the first MCU 202 or the second MCU 204 realize a detection unit that detects that the actuator 104 is within a predetermined range with respect to the switch body 102. Note that the strength of the wireless signal may be used directly instead of the distance d to detect the position of the actuator 104. The demodulator 212a of the first MCU 202 and the demodulator 212b of the second MCU 204 each demodulate information carried by a wireless signal from the actuator communication unit 124 received via the sensor side coil 152 and the receiving circuit 208, and identify the actuator 104 based on this information. This information may include unique identification information.

[0052] The safety determination circuit 214a of the first MCU 202 determines whether or not two conditions are satisfied, that the estimated distance d is equal to or less than a threshold and that the actuator 104 is identified as a predetermined actuator, based on the measurement by the measurement unit 210a and the identification by the demodulation unit 212a, and transmits the determination result to the second MCU 204. More specifically, there are two types of determination results: that both conditions are satisfied, or that at least one of the conditions is not satisfied. Similarly, the safety determination circuit 214b of the second MCU 204 determines whether or not two conditions are satisfied, that the estimated distance d is equal to or less than a threshold and that the actuator 104 is identified as a predetermined actuator, based on the measurement by the measurement unit 210b and the identification by the demodulation unit 212b, and transmits the determination result to the first MCU 202. When the safety determination circuit 214a of the first MCU 202 and the determination result of the second MCU match, the safety determination circuit 214a outputs a safety-related output that determines that the actuator 104 identified as the predetermined actuator is in a predetermined range with respect to the switch body 102, that is, the door PD is in a closed state. Similarly, when the safety determination circuit 214b of the second MCU 204 and the determination result of the first MCU match, the safety determination circuit 214b of the second MCU 204 determines that the actuator 104 identified as the predetermined actuator is in a predetermined range with respect to the switch body 102, that is, the door PD is in a closed state. Note that in this embodiment, as described later, when a condition related to a signal input via the input circuit 220 is also satisfied, the first MCU 202 and the second MCU 204 output a safety-related output via an OSSD (Output Signal Switching Device), but the safety-related output may be output based on a wireless signal received via the receiving circuit 208 and the mutual determination results of the first MCU 202 and the second MCU 204.Furthermore, in this embodiment, the distance d between the switch body 102 and the actuator 104 is estimated and the actuator 104 is identified based on the wireless signal detected by the sensor side coil 152, but a configuration may also be adopted in which only the distance d is estimated and the safety judgment circuits 214a, 214b do not make a judgment regarding the identification of the actuator 104, but rather output the judgment result of whether the distance d is below a threshold value to the other safety judgment circuit.

[0053] 13, the input circuit 220 has a first safety input unit 222, a second safety input unit 224, and a lock input unit 226. The first safety input unit 222 and the second safety input unit 224 are connected to other devices capable of outputting a safety-related output. In other words, the first safety input unit 222 and the second safety input unit 224 are input circuits for daisy-chaining the switch main body 102 and the other devices. For example, the first safety input unit 222 and the second safety input unit 224 are connected such that one of the terminals for outputting a safety-related output of the other device is connected to the first safety input unit 222, and another of the terminals for outputting a safety-related output of the other device is connected to the second safety input unit 224.

[0054] The lock input unit 226 is connected to an external control device such as a safety PLC or a safety control device, and receives a lock signal for controlling a lock mechanism output from the external control device, and outputs an input signal to the second MCU 204. The second MCU 204 determines whether the signal input via the lock input unit 226 is an ON signal. The second MCU 204 can drive the electromagnet 130 based on the lock signal input via the lock input unit 226 to attract the electromagnet 130 to the iron piece 120 of the actuator 104. That is, the door PD is locked by a magnetic force in response to the signal input via the lock input unit 226. The second MCU 204 may drive the electromagnet 130 when the signal input via the lock input unit 226 is an ON signal, or may drive the electromagnet when it is determined that the signal input via the lock input unit 226 is an ON signal and other conditions are satisfied. For example, the above-mentioned determination by the safety determination circuits 214a, 214b may be set as a condition for driving the electromagnet 130. In this case, the electromagnet 130 is driven when it is determined that a predetermined actuator 104 is in a predetermined range with respect to the switch body 102, so that the door PD is more reliably maintained in a closed state by the lock signal output by the external control device.

[0055] The control circuit 200 includes a first OSSD 230a and a second OSSD 230b as the switching device 230. The first MCU 202 and the second MCU 204 each generate a safety signal, the first MCU 202 outputs a safety-related output as a safety signal via the first OSSD 230a, and the second MCU 204 outputs a safety-related output as a safety signal via the second OSSD 230b. Note that the external device to which the safety-related output is output via the first OSSD 230a and the second OSSD 230b and the external control device that outputs the lock signal input via the lock input unit 226 may be the same device or different devices, but both of them constitute the partition system 1.

[0056] The first OSSD 230a and the second OSSD 230b are, for example, configured with a PNP transistor. When the PNP transistor is turned ON, the output terminal is connected to the +side power supply, and an ON signal is output. On the other hand, when the PNP transistor is turned OFF, the output terminal is grounded via a pull-down resistor, and an OFF signal is output.

[0057] The first OSSD 230a and the second OSSD 230b may be connected to an OSSD monitoring circuit 232, respectively. The OSSD monitoring circuit 232 is connected to the first MCU 202 and the second MCU 204. The first MCU 202 monitors whether the second OSSD 230b is operating normally through the OSSD monitoring circuit 232. The second MCU 204 monitors whether the first OSSD 230a is operating normally through the OSSD monitoring circuit 232. For example, the first OSSD 230a and the second OSSD 230b each periodically transition their output signal to OFF for a very short time when outputting an ON signal. If the OSSD monitoring circuit 232 can detect an OFF state for a very short time during the output period of the ON signal, it determines that the OSSD is normal, and if it cannot detect an OFF state for a very short time, it determines that the OSSD is not normal.

[0058] In addition, a case where the OSSD monitoring circuit 232 cannot detect a very short OFF and an ON signal continues is caused, for example, by a short circuit between the output terminal and the positive power supply. In this case, the safety determination circuits 214a, 214b output control signals to the first OSSD 230a and the second OSSD 230b to output an OFF signal. As a result, the first OSSD 230a and the second OSSD 230b that operate normally output an OFF signal. In addition, the transition of the safety-related output to OFF for monitoring by the OSSD monitoring circuit 232 is set to a very short time so that the external device to which the safety-related output is output does not react to the OFF.

[0059] The power supply circuit 240 is a DC-DC converter that receives DC +24V and 0V from the outside and generates DC voltages such as DC +10V, +5V, and +3.3V. The power supply circuit 240 supplies power to all circuits that require power, such as the control circuit 200, the sensor side coil 152, and the display unit 142. However, if the supply voltage from the external power source or the voltage output from the power supply circuit 240 is not within a predetermined range, the control circuit 200 and the like may not operate normally. Therefore, the power supply monitoring circuit 242 judges whether the supply voltage from the external power source is within a predetermined range, and judges whether the voltage output from the power supply circuit 240 is within a predetermined range, and outputs the judgment results to the first OSSD 230a and the second OSSD 230b. When the judgment results indicating that the power supply circuit 240 is not operating normally are input, the first OSSD 230a and the second OSSD 230b each turn off the safety-related output without depending on the control signal output from the control circuit 200. When the first OSSD 230a and the second OSSD 230b receive a determination result indicating that the power supply circuit 240 is operating normally, they each output a safety-related output depending on a control signal output from the control circuit 200.

[0060] The control circuit 200 includes an indicator light control unit 252 that controls the display unit 142, and the indicator light control unit 252 included in the second MCU 204 supplies a display state signal corresponding to the safety-related output via at least the second OSSD 230b to the indicator light control unit 252. The relationship between the ON / OFF of the safety-related output and the determination results in the first MCU 202 and the second MCU 204 will be described with reference to Fig. 16.

[0061] The column "indicator lamp" in FIG. 16 indicates the light emission pattern of the display unit 142 controlled based on the display status signal supplied to the display control unit 252. The column "status" is subdivided into "OSSD", "safety input", "lock control input", and "actuator". The column "OSSD" indicates whether the safety-related output outputted to the external control device via the first OSSD 230a and the second OSSD 230b as the switching device 230 is ON or OFF. The columns "safety input", "lock control input", and "actuator" indicate the judgment items used when determining whether the safety-related output outputted via the switching device 230 is ON or OFF. The column "safety input" indicates whether the safety-related output inputted via the first safety input unit 222 and the second safety input unit 224 is ON or OFF. The column "lock control input" indicates whether the lock signal inputted from the external control device via the lock input unit 226 is ON or OFF. The column “Actuator” indicates whether an actuator 104, identified as a specified actuator based on a radio signal received via the sensor side coil 152 and the receiving circuit 208, has been detected to be within a specified range of the switch body 102.

[0062] As shown in FIG. 16, in this embodiment, the safety-related output outputted through the switching device 230 is ON when the safety-related output inputted through the first safety input unit 222 and the second safety input unit 224 is ON, the lock signal inputted through the lock input unit 226 is ON, and the actuator 104 is detected. At this time, the light-emitting pattern of the display unit 142 is green. When the actuator 104 is not detected, the safety-related output outputted through the switching device 230 is OFF regardless of the safety-related output or the lock signal inputted through the first safety input unit 222 and the second safety input unit 224, and the light-emitting pattern of the display unit 142 is red. The safety switch 100 of this embodiment detects whether the actuator 104 is within a predetermined range with respect to the switch body 102 in order to maintain the operating area S in a safe environment. When the actuator 104 is not detected, the door PD is not in a closed state and the operating area S is not maintained as a safe environment, so the safety-related output outputted through the switching device 230 is OFF regardless of the input state of other signals.

[0063] The safety switch 100 of this embodiment determines whether to turn on or off the safety-related output outputted through the switching device 230 by referring to the input states of various signals in addition to the detection of the actuator 104. At this time, it is difficult for an operator to grasp the state of the safety-related output and the lock signal inputted through the first safety input unit 222 and the second safety input unit 224, compared to the detection of the actuator 104. More specifically, whether the actuator 104 is detected or not has a certain correlation with whether the door PD is in a closed state or not. Therefore, when the actuator 104 is not detected and the safety-related output outputted from the switch main body 102 through the switching device 230 is OFF, it is easy for an operator to identify the cause. In contrast, with regard to the safety-related output and the lock signal inputted through the first safety input unit 222 and the second safety input unit 224, although an operator can check from the outside whether the cables corresponding to these are connected or not, it is difficult for an operator to grasp from the outside what the signals supplied through the cables are. For this reason, in this embodiment, when the safety-related output output via the switching device 230 is OFF due to the input states of various signals, the illumination pattern of the display unit 142 is changed according to the input states of various signals, making it easier for the operator to identify the reason why the safety-related output output from the switch main body 102 via the switching device 230 is OFF.

[0064] In this embodiment, since another device capable of outputting a safety-related output is connected to the first safety input unit 222 and the second safety input unit 224, the safety-related output output by the switch main body 102 and the light-emitting pattern of the display unit 142 change depending on the "safety input" column in Fig. 16. However, if the other device is not connected, the safety-related output output by the switch main body 102 and the light-emitting pattern of the display unit 142 may be determined depending on the "lock control input" column and the "actuator" column. In this case, when the "lock control input" column is "ON" and the "actuator" column is "Detected", the safety-related output output by the switch main body 102 is ON and the light-emitting pattern of the display unit 142 is lit in green. In this case, there is no case in which the light-emitting pattern of the display unit 142 is "orange" or "flashing orange" as shown in Fig. 16.

[0065] As described above, the measurement unit 210a of the first MCU 202 and the measurement unit 210b of the second MCU 204 measure the wireless signal received from the actuator communication unit (RFID) 124 (FIG. 4) via the sensor side coil 152 (FIG. 9) to estimate the distance d between the actuator 104 and the switch body 102. In addition, if the distance d2 between the attraction surface 130a and the attracted surface 120a is equal to or less than the threshold value and the lock signal input via the lock input unit 226 is ON, the second MCU 204 drives the electromagnet 130 to attract the iron piece 120.

[0066] With reference to FIG. 18, the determination of whether the distance d2 is equal to or smaller than the threshold value will be specifically described. The second MCU 204 supplies a test current to the electromagnet 130 and monitors the current flowing through the electromagnet 130 at this time. (I) in FIG. 18 shows a rectangular wave of the test current. The value of this test current is smaller than the value of the lock current supplied to the electromagnet 130 to maintain the door PD in a closed state, i.e., to form the locked state of the safety switch 100. If a current with the same value as the lock current is used for the test, the electromagnet 130 will attract the iron piece 120 with an attractive force sufficient to maintain the door PD in a closed state even if the lock signal is not ON, which will cause an obstacle to the operation of opening the door PD and reduce the operability of the worker. For this reason, the value of the test current can be set to a value smaller than the value of the lock current, particularly to a weak value at which the electromagnet 130 exerts almost no attractive force, thereby maintaining the operability of the worker.

[0067] Fig. 18(II) shows the monitoring current flowing through the electromagnet 130 in response to the inspection current of the rectangular wave in Fig. 18(I) when the electromagnet 130 and the iron piece 120 are not in close contact with each other, i.e., when the distance d2 between the attracting surface 130a and the attracted surface 120a is greater than the threshold value. Fig. 18(III) shows the monitoring current flowing through the electromagnet 130 in response to the inspection current of the rectangular wave in Fig. 18(I) when the electromagnet 130 and the iron piece 120 are in close contact with each other, i.e., when the distance d2 between the attracting surface 130a and the attracted surface 120a is equal to or less than the threshold value. As can be seen by comparing (II) and (III) in Figure 18, when the electromagnet 130 and the iron piece 120 are in close contact with each other, that is, when the distance d2 between the attracting surface 130a and the attracted surface 120a is smaller than the threshold value, the inductance is larger than when the distance d2 is equal to or larger than the threshold value, and therefore the time from when the supply of the inspection current begins to when the value of the monitoring current reaches a constant value becomes longer.

[0068] When the time from when the supply of the inspection current is started until the value of the monitoring current reaches a certain value differs, the value of the current flowing through the electromagnet 130 at the timing when a certain time has elapsed since the supply of the inspection current is started differs. For comparison between (II) and (III) of FIG. 18, the timing when a certain time has elapsed since the supply of the inspection current to the electromagnet 130 is started is illustrated as the inspection confirmation timing. The value of the monitoring current flowing through the electromagnet 130 at the inspection confirmation timing in a state where the distance d2 between the attracting surface 130a and the attracted surface 120a is greater than the threshold is the first monitoring current value I1 shown in (II) of FIG. 18. The value of the monitoring current flowing through the electromagnet 130 at the inspection confirmation timing in a state where the distance d2 between the attracting surface 130a and the attracted surface 120a is equal to or smaller than the threshold is the second monitoring current value I2 shown in (III) of FIG. Comparing the first monitoring current value I1 and the second monitoring current value I2, the first monitoring current value I1 is larger. That is, a monitoring current that takes a short time from the time the inspection current is supplied until it reaches a certain value ((II) in FIG. 18), in other words, a monitoring current with high responsiveness, has a larger current value at the inspection confirmation timing, compared with a monitoring current with low responsiveness ((III) in FIG. 18). Therefore, by comparing the values ​​of the monitoring current at the inspection confirmation timing, it is possible to determine whether the responsiveness of the monitoring current flowing through the electromagnet 130 is high or low, the inductance associated with the responsiveness, and the distance d2 between the attracting surface 130a and the attracted surface 120a associated with the inductance. More specifically, a threshold current value is set at least between the first monitoring current value I1 and the second monitoring current value I2 so that the magnitude relationship between the distance d2 and the threshold value can be determined, and whether the distance d2 is greater than or equal to the threshold value is determined depending on whether the current value of the monitoring current at the inspection confirmation timing is greater than or equal to the threshold value.

[0069] FIG. 19 is a vertical cross-sectional view of the actuator 104 showing a preferred embodiment of the actuator 104. FIG. 19 shows the actuator 104 attached to the door PD in which the door frame 6 is attached in parallel to the door opening frame 2 to which the switch body 102 is attached in the manner of FIG. 2. Therefore, the normal direction of the door frame 6 (PD) coincides with the Y-axis direction as the normal direction of the attracting surface 130a of the electromagnet 139 provided in the switch body 102. Furthermore, the actuator 104 in FIG. 19 is in a state in which the normal direction of the attracted surface 120a of the iron piece 120 provided in the actuator 104 coincides with the Y-axis direction. The actuator 104 may have a structure in which the iron piece 120 is fixed to the mounting bracket 126, but the actuator 104 shown in FIG. 19 has the iron piece 120 movable with respect to the mounting bracket 126.

[0070] 19, the mounting bracket 126 described above constitutes a base member of the actuator 104. The mounting bracket 126 has a U-shaped cross section with flanges on both ends, and has a through hole 126a at the center of the flat top. The actuator 104 has a movable pin 320 inserted into the through hole 126a of the mounting bracket 126, and one end of the movable pin 320 is fixed to the iron piece 120. The iron piece 120 has a permanent magnet 120b that is circular when viewed from the front, at the center of its attracted surface 120a. The movable pin 320 inserted into the through hole 126a of the mounting bracket 126 can move in the axial direction of the movable pin 320 relative to the mounting bracket 126, and this configuration constitutes a mechanism for moving the attracted surface 120a relative to the mounting bracket 126.

[0071] The movable pin 320 has a pin head 320a located at the end on the mounting bracket 126 side. The movable pin 320 is inserted into a sleeve 322. The sleeve 322 has a length in the axial direction of the movable pin 320, and has one end flange 322a and the other end flange 322b that both extend radially outward and in the circumferential direction. The one end flange 322a and the other end flange 322b of the sleeve 322 are used to keep the position of the iron piece 120 constant relative to the movable pin 320, and the iron piece 120, the movable pin 320, and the sleeve 322 move relative to the mounting bracket 126.

[0072] The movable pin 320 and the sleeve 322 are movable in the axial direction of the movable pin 320 with the outer circumferential surface of the sleeve 322 guided by the through hole 126a. The sleeve 322 has a guide function for guiding the movement of the movable pin 320 in the axial direction. The movable pin 320 can also swing in the through hole 126a together with the sleeve 322. That is, the diameter of the sleeve 322 is smaller than the diameter of the through hole 126a, and the sleeve 322 is loosely fitted in the through hole 126a. With this configuration, a swing mechanism for swinging the attracted surface 120a is configured.

[0073] A compression coil spring 324 is provided between one end flange 322a of the sleeve 322 and the mounting metal fitting 126. The compression coil spring 324 constitutes a biasing means that biases the movable pin 320 and the attracted surface 120a in a direction approaching the door frame 6.

[0074] FIG. 20(I) is a plan view of the compression coil spring 324. FIG. 20(II) is a side view of the compression coil spring 324 in an unloaded state. FIG. 20(III) is a side view of the compression coil spring 324 in a compressed state under load. As can be seen from FIG. 20(I), the compression coil spring 324 is composed of a spiral spring that is trapezoidal in side view and has a gradually decreasing diameter in the axial direction. This spiral-shaped compression coil spring 324 can become flat in side view in the compressed state. Therefore, the range of movement of the movable pin 320 is expanded in the direction in which the compression coil spring 324 is compressed.

[0075] In this embodiment, the state of the actuator 104 shown in Fig. 19, i.e., the state in which the iron piece 120 is moved by the compression coil spring 324 in a direction approaching the door frame 6, in other words, in a direction away from the electromagnet 130, is defined as a standby state, and the position of the iron piece 120 in this state is defined as a standby position. The standby position of the iron piece 120 corresponds to the position of the iron piece 120 represented by the two-dot chain line shown in Fig. 17. Note that examples of modified examples of the compression coil spring 324 include a disc spring, rubber, or other elastic body.

[0076] A cushion member 326 is disposed between the other end flange 322b of the sleeve 322 and the mounting bracket 126 and iron piece 120 (FIG. 19). As will be described later, the impact generated when the iron piece 120 overlaps with the attraction surface 130a of the electromagnet 130 based on the attractive force of the permanent magnet 120b is mitigated by the compression coil spring 324 and the cushion member 326.

[0077] 21 is a diagram for explaining the action of actuator 104. Fig. 21(I) shows actuator 104 in a standby state, and corresponds to Fig. 19.

[0078] FIG. 21 (II) illustrates a state in which the actuator 104 approaches the attraction surface 130a of the electromagnet 130 provided in the switch body 102 as the door PD is in the process of changing from an open state to a closed state, that is, in the process in which the operator closes the door PD. At this time, the electromagnet 130 is not driven. As shown in FIG. 21 (II), when the actuator 104 approaches the electromagnet 130, the attraction force of the permanent magnet 120b provided in the actuator 104 acts on the attraction surface 130a of the electromagnet 130. When this attraction force becomes larger than the spring force of the compression coil spring 324, the compression coil spring 324 starts to compress. Then, under the attraction force of the permanent magnet 120b, the movable pin 320 and the iron piece 120 move together with the actuator housing 122 in a direction away from the door frame 6, that is, in a direction approaching the attraction surface 130a. Therefore, for example, when the door PD is closed and the distance between the actuator 104 and the switch body 102 falls within a certain range, the movable pin 320 and the iron piece 120, together with the actuator housing 122, move along the Y-axis direction in a direction approaching the adsorption surface 130a.

[0079] FIG. 21 (III) shows a state in which the attracted surface 120a and the attracting surface 130a are in close contact with each other due to the attractive force of the permanent magnet 120b after the process of FIG. 21 (II). The threshold value for the distance d is set so that the distance d estimated based on the strength of the wireless signal received from the actuator communication unit 124 via the sensor-side coil 152 in this state is equal to or smaller than the threshold value, that is, so that the actuator communication unit 124 determines in this state that the actuator 104 is within a predetermined range relative to the switch body 102. In addition, in the state of FIG. 21 (III), the second MCU 204 supplies a detection current to the electromagnet 130 and monitors the current flowing through the electromagnet 130 to determine whether the attracted surface 120a and the attracting surface 130a are in close contact with each other. When it is determined that the attracted surface 120a and the attracting surface 130a are in close contact with each other, the second MCU 204 drives the electromagnet 130 to attract the iron piece 120 so as to maintain the door PD in a closed state. In this embodiment, when the door PD is closed, the iron piece 120 moves toward the attracting surface 130a by the attractive force of the permanent magnet 320 of the actuator 104, and the attracting surface 130a and the attracted surface 120a come into close contact with each other, but the movement of the iron piece 120 toward the attracting surface 130a may be realized by other means. For example, the iron piece 120 may move toward the attracting surface 130a by inertia when the door PD is closed. Alternatively, the electromagnet 130 may be driven to generate an attractive force weaker than the attractive force for maintaining the door PD closed, and the iron piece 120 may move toward the attracting surface 130a by the attractive force.

[0080] FIG. 22 is a cross-sectional view for explaining the state change of the actuator 104. FIG. 22(I) is a view corresponding to FIG. 19(I), and the actuator 104 is in a standby state. FIG. 22(II) shows a state when the iron piece 120 of the actuator 104 is in a maximum action position where it is fully advanced, that is, when the movable pin 320 is in a maximum stroke position where it is displaced in its axial direction, that is, in the Y-axis direction. This state can be created by the attraction force of the permanent magnet 320. FIG. 22(III) is a view for explaining that the iron piece 120 can be swung so that the attracted surface 120a is parallel to the attracting surface 130a when the iron piece 120 overlaps with the attracting surface 130a under the attraction force of the permanent magnet 320. The parallel state of the attracted surface 120a and the attracting surface 130a is established by the swing of the movable pin 320, that is, the tilting of its axis Ax.

[0081] As described above, the actuator communication unit 124 is disposed in the actuator housing 122 surrounding the periphery of the iron piece 120 (FIG. 3). On the other hand, the sensor side coil 152 is disposed in the switch body 102 (FIG. 9). Based on the strength of the wireless signal received from the actuator communication unit 124 via the sensor side coil 152, it is determined whether the actuator 104 is within a predetermined range relative to the switch body 102, i.e., whether the distance d is equal to or less than a threshold value.

[0082] However, when the electromagnet 130 and the sensor-side coil 152 are provided in a positional relationship close to each other in the switch body 102, the magnetic flux leaking from the electromagnet 130 to the surroundings may affect the strength of the wireless signal received from the actuator communication unit 124 via the sensor-side coil 152. In particular, in this embodiment, the diameter D1 of the attracted surface 120a is set to be larger than the diameter D2 of the attracting surface 130a. Therefore, when the attracting surface 130a and the attracted surface 120a are in contact with each other, the sensor-side coil 152 faces the coil provided in the actuator communication unit 124 in such a positional relationship that at least a part of the sensor-side coil 152 provided near the electromagnet 130 overlaps with the attracted surface 120a when viewed in the normal direction of the attracting surface 120a. For this reason, magnetic flux leakage that affects the strength of the wireless signal received via the sensor-side coil 152 is likely to occur. In order to reduce the effect of magnetic flux leakage on the wireless signal, the electromagnet of this embodiment has a configuration shown in FIG. 23. As is well known, the electromagnet 130 includes a core 140a and a cylindrical yoke portion Yk surrounding the core 140a. The core 140a and the yoke portion Yk may be made separately, but in this embodiment, the core 140a and the yoke portion Yk are made integrally. In addition, in this embodiment, the above-mentioned protruding portion 130b is configured as a part of the yoke portion Yk. That is, the yoke portion Yk has a shape in which a part of the circumferential direction protrudes radially outward. As a modified example, a mounting portion for mounting the switch body 102 may be provided on the switch body 102 in addition to the protruding portion 130b that protrudes a part of the yoke portion Yk radially outward.

[0083] The yoke portion Yk has a role of improving the attraction force through the magnetic flux from the electromagnet 130. FIG. 24 is a cross-sectional view taken along the line XXIII-XXIII in FIG. 23. The arrows 190 in FIG. 24 are drawn with dashed lines to indicate the magnetic flux leaking from the electromagnet 130. In FIG. 24, reference numeral 140a indicates a core. A magnet wire is wound around the core 140a. In FIG. 24, a void 140b is drawn between the core 140a and the yoke portion Yk located on its outer periphery, and as is well known, a magnet wire is located in the void 140b. The electromagnet 130 attracts the actuator 104, and thus a magnetic circuit is formed between the electromagnet 130 and the actuator 104. The magnetic flux in the magnetic circuit is indicated by arrows filled with black. The magnetic flux generated from the core 140a is generated approximately uniformly in the circumferential direction of the yoke portion Yk. It is also known that the magnetic flux passing through the yoke portion Yk leaks out of the yoke portion Yk when the density of the magnetic flux passing through is high. By providing the protruding portion 130b on a part of the yoke portion Yk, the cross-sectional area of ​​the part of the yoke portion Yk where the protruding portion 130b is provided in the circumferential direction is larger than that of the other parts in the circumferential direction. Therefore, the magnetic flux density of the part of the yoke portion Yk where the protruding portion 130b is provided in the circumferential direction is relatively low compared to the other parts, and this reduces magnetic flux leakage near the protruding portion 130b.

[0084] The sensor side coil (antenna coil) 152 is disposed near the protruding portion 130b. To specifically explain a preferred arrangement of the sensor side coil 152, with reference to Fig. 23, if the periphery of the suction surface 130a is divided into four regions by a first center line CL1 that passes through the center O2 of the suction surface 130a and the center line of the protruding portion 130b, and a second center line CL2 that passes through the center O2 and is perpendicular to the first center line CL1, in the illustrated example, the sensor side coil 152 is disposed in the first quadrant on one side of the protruding portion 130b. Of course, the sensor side coil 152 may be disposed in the second quadrant on the other side of the protruding portion 130b. Furthermore, the sensor side coil 152 is positioned so as to be located on the side of the adsorption surface 130a of a first tangent line TL1 that is perpendicular to the first center line CL1 and tangent to the top surface of the protrusion 130b, and also so as to be located on the side of the adsorption surface 130a of a second tangent line TL2 that is perpendicular to the second center line CL2 and tangent to the outer periphery of the adsorption surface 130a.

[0085] In order to explain the advantage of arranging the sensor side coil (antenna coil) 152 in the vicinity of the protruding protrusion 130b, an electromagnet 400 of a comparative example shown in Figs. 25 and 26 will be explained. Fig. 25 is a view of the electromagnet 400 of the comparative example seen from the side of the attraction surface 400a. The yoke portion Yk has the same thickness in the circumferential direction. Fig. 26 is a cross-sectional view taken along the line XXV-XXV of Fig. 25. In the figure, reference numeral 402 indicates a core. Referring to Fig. 26, the electromagnet 400 of the comparative example is caused to attract the actuator 410, so that a magnetic circuit is formed between the actuator 410 and the electromagnet 400. The magnetic flux in the magnetic circuit is indicated by an arrow filled with black. In the magnetic circuit of this configuration, magnetic flux leakage occurs around the yoke portion Yk. The magnetic flux leakage is indicated by an arrow 190 drawn with a dashed line.

[0086] When a sensor side coil (antenna coil) 152 is arranged near the electromagnet 400 on the outer periphery of the electromagnet 400 of the comparative example, the sensor side coil (antenna coil) 152 is affected by the magnetic flux 190 leaking from the yoke portion Yk (Figure 26), and this leaked magnetic flux 190 affects the signal strength detected by the sensor side coil (antenna coil) 152.

[0087] 23 and 24 relating to this embodiment, the protruding portion 130b constituting a part of the yoke portion Yk is relatively thick, which makes it difficult for magnetic flux to leak near the protruding portion 130b. By arranging the sensor side coil (antenna coil) 152 near the protruding portion 130b where magnetic flux is unlikely to leak (FIG. 23), it is possible to reduce the effect of magnetic flux leakage on the signal strength detected by the sensor side coil (antenna coil) 152.

[0088] As described above, the protrusion 130b has the effect of reducing the magnetic flux density at the portion where the protrusion 130b is provided. In general, the magnetic attraction force of a magnet varies depending on the magnetic flux density of the surface that comes into contact with the object to be attracted. For this reason, the electromagnet 130 is shaped so that when the electromagnet 130 attracts the iron piece 120, a gap Gp (FIG. 24) is formed between the iron piece 120 and the protrusion 130b. Due to the gap Gp, the area of ​​the yoke portion Yk where the protrusion 130b is provided that contacts the iron piece 120 can be made smaller than the cross-sectional area of ​​the portion where the protrusion 130b is located in the Y-axis direction. Thus, by providing the protrusion 130b, it is possible to suppress the reduction in the magnetic flux density at the portion that contacts the iron piece 120, and therefore the magnetic attraction force of the electromagnet 130 can be maintained. In other words, the gap Gp can effectively stabilize the attraction. The gap Gp can be formed by designing the relatively thick protrusion (protrusion 130b) so that it can be positioned in a position retreated in the Y-axis direction from the attraction surface 130a (FIG. 24). In addition, in the electromagnet 130 of this embodiment, the gap Gp is ​​formed so that the yoke portion Yk basically has the same thickness in the circumferential direction, and therefore the magnetic flux density in the circumferential direction at the portion where the yoke portion Yk contacts the iron piece 120 is the same. This makes it possible to more stably attract the actuator 104 by the electromagnet 130.

[0089] 27 to 29 are diagrams for explaining an example of attaching the switch body 102 to the door opening frame 2. In the drawings, reference numeral 350 denotes a level adjustment member for adjusting the height level of the switch body 102. FIG. 27 shows an example in which the switch body 102 is fixed to the level adjustment member 350, and the switch body 102 is fixed to the first bracket 106 via the level adjustment member 350. FIG. 28 shows a modified example of FIG. 27, in which an intermediate metal plate 132a connected to the electromagnet 130 is interposed between the electromagnet 130 and the board housing portion 132, and the switch body 102 is fixed to the intermediate metal plate 132a with a screw. In this way, a mounting portion for fixing the switch body 102 to the first bracket 106 is provided in front of the housing Hg forming the board housing portion 132, so that the housing Hg is less susceptible to impact caused by the actuator 104 abutting against the electromagnet 130. Therefore, even if the housing Hg is made of a relatively inexpensive resin, the housing Hg can be made long in the front-rear direction as shown in FIG. 28. FIG. 29 shows a modification of FIG. 27, in which at least the upper part of the board accommodating section 132 is formed of a metal housing 352, the switch body 102 is screwed to the metal housing 352 of the board accommodating section 132, and the switch body 102 is fixed to the first bracket 106 via a level adjustment member 350. The metal housing 352 is connected to the electromagnet 130. In this modification, the durability of the switch body 102 is improved by providing the metal housing 352 that has an attachment portion and forms the board accommodating section 132 against the impact caused by the actuator 104 abutting against the electromagnet. In the first modification shown in FIG. 28 and the second modification shown in FIG. 29, the board Cb may adopt a floating support structure, or may be filled with resin.

[0090] 27, the safety switch 100 is described. The length dimension L of the switch body 102 in the Y-axis direction is larger than the diameter of the attraction surface 130a. In an electromagnet to which a certain current is applied, the strength of the attraction force of the electromagnet is proportional to the number of turns of the coil. Therefore, in order to realize a certain attraction force without increasing the diameter dimension of the attraction surface 130a, the electromagnet 130 of this embodiment has a certain length in the front-rear direction. If there is a limit to the length of the entire switch body 102 in the front-rear direction, i.e., in the Y-axis direction, it becomes more difficult to form a storage section behind the electromagnet 130 as the front-rear dimension of the electromagnet 130 becomes longer. According to a configuration in which the length dimension L of the switch body 102 in the Y-axis direction is larger than the diameter of the attraction surface 130a, a housing Hg in which a storage section is formed can be arranged behind the electromagnet 130, so that the area occupied by the switch body 102 in the opening can be reduced. Furthermore, in this embodiment, the total length L0 of the switch body 102 and the actuator 104 in the Y-axis direction is designed to be larger than the diameter of the attraction surface 130a. [Explanation of symbols]

[0091] PF Protective fence (fixed section) PD Opening and closing door (moving part) 2 Door opening frame S Working area surrounded by a protective fence 100 Example of safety switch with electromagnetic lock mechanism 102 Switch body 104 Actuator 120 Actuator iron piece (magnetic material) 120a Adsorption surface 124 Actuator communication unit (actuator coil) 130 Electromagnet 130a Adsorption surface 130b Mounting part 132 Substrate storage section Hg housing 140a Electromagnet Core Yk yoke part of electromagnet 142 Display section 144 Connector joint 152 Sensor side coil (antenna coil) Cb substrate Gp Gap

Claims

1. A safety switch in which an actuator having a magnetized member with a suction surface formed thereon is installed so as to be relatively movable with respect to a switch body, a detection unit that detects that the actuator is within a predetermined range with respect to the switch body, an electromagnet having a suction surface corresponding to the suction surface of the actuator formed on the front side, a lock input unit that receives a lock signal for locking the relative movement of the actuator, a drive control unit that drives the electromagnet so that the suction surface and the suction target surface are attracted based on the lock signal received by the lock input unit, a safety control unit that generates a safety signal based on the detection by the detection unit, a safety switch, comprising: a housing that forms a housing portion for housing the drive control unit and the safety control unit on the back side of the electromagnet.

2. A safety switch comprising an actuator having a magnetized member with a suction surface formed thereon and a switch body having a suction surface corresponding to the suction surface, wherein the switch body, a detection unit that detects that the actuator is within a predetermined range with respect to the switch body, an electromagnet having the suction surface formed on the front side, one or more control boards that pass a locking current through the electromagnet so that the suction surface and the suction target surface are attracted, a housing provided on the back side of the electromagnet for housing the one or more control boards, a connector connection portion provided on the housing, and comprising, wherein the one or more control boards, receive a lock signal for passing the locking current through the connector connection portion, generate a safety signal based on the detection by the detection unit, and output the safety signal through the connector connection portion, a safety switch.

3. The safety switch according to claim 1, comprising one or more control boards on which the drive control unit and the safety control unit are mounted.

4. The safety switch according to claim 1 or 2, wherein the electromagnet is connected to the housing on the back side.

5. The safety switch according to claim 1 or 2, wherein the housing further has a display unit indicating an operating state of the switch body.

6. The safety switch according to claim 5, wherein the switch body further comprises a mounting portion for mounting the switch body at an installation location. The display unit is provided at a position visible from the opposite side of the surface on which the mounting portion of the switch body is located, a safety switch

7. In the safety switch according to claim 1, A safety switch, wherein a connector connecting portion is provided on the back surface of the switch body.

8. In the safety switch according to claim 2, A safety switch, wherein the connector connecting portion is provided on the back surface of the housing.

9. In the safety switch according to claim 5, A safety switch, wherein the display unit is inclined forward.

10. In the safety switch according to claim 1 or 2, The adsorption surface of the electromagnet is smaller than the adsorbed surface of the actuator, The detection unit has an antenna coil that exchanges wireless signals with an actuator coil provided on the actuator, In a first state in which the adsorption surface of the electromagnet and the adsorbed surface of the actuator that contacts the adsorption surface face each other and the adsorption surface and the adsorbed surface contact each other, the antenna coil is provided at a position facing the actuator coil, a safety switch.

11. In the safety switch according to claim 10, The electromagnet is provided with a protrusion for reducing the influence on the antenna coil due to driving of the electromagnet in the vicinity of the position where the antenna coil is provided, a safety switch.

12. In the safety switch according to claim 10, A safety switch, wherein the protrusion and the adsorbed surface face each other through a gap in the first state.

13. In the safety switch according to claim 1, The drive control unit drives the electromagnet so that the adsorption surface and the adsorbed surface adsorb based on the detection result by the detection unit and the lock signal received by the lock input unit, a safety switch.

14. In the safety switch according to claim 2, The one or more control boards flow a current for locking to the electromagnet so that the adsorption surface and the adsorbed surface adsorb based on the detection result by the detection unit and the lock signal, a safety switch.

15. In the safety switch according to claim 1 or 2, A safety switch, wherein an attachment portion for attaching the switch body to an installation location is formed on the electromagnet.

16. In the safety switch according to claim 1 or 2, Comprising a metal member connected to the electromagnet, A safety switch, wherein a mounting portion for mounting the switch body at an installation location is formed on the metal member.

17. In the safety switch according to claim 1 or 2, the adsorption surface constitutes the front surface of the switch body, in a first state in which the magnetization member of the actuator that contacts the adsorption surface faces the adsorption surface and the adsorption surface and the adsorbed surface of the magnetization member are in contact, the total length of the magnetization member and the safety switch in a direction orthogonal to the adsorption surface is greater than the diameter of the adsorption surface. A safety switch characterized by this.

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