Safety switch

Abstract

To prevent an operator from being disturbed.SOLUTION: A safety switch (100) includes a switch body (104) including an electromagnet (130), and an actuator (104) attracted to the electromagnet (130). The switch body (104) has a drive control unit and a safety control unit for controlling the safety switch (100), and the drive control unit and the safety control unit are surrounded by a housing (Hg). The housing (Hg) is disposed on a back side of the electromagnet (130) of the switch body (102), and the housing (Hg) forms a housing portion (132) that houses the drive control portion and the safety control portion.SELECTED DRAWING: Figure 8

Description

[Technical Field]

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

[0002] In the environment where the equipment is operating, if the human body can freely come into contact with the equipment, there is a risk that the equipment may cause harm to the human body. In the environment where the equipment is operating, in order to prevent harm to the human body from the operating equipment, in other words, to achieve a safe state, the equipment is enclosed by protective fences and partition panels. The operating area in which the equipment operates is partitioned. One method for achieving a safe state by partitioning the operating area is to partition the operating area with fixed parts such as protective fences to prevent human bodies from entering the operating area, i.e., to isolate the operating area from areas where human bodies are present. Another method is to construct a partitioning system that partitions the operating area and can restrict the operation of equipment. In a partitioning system, the operating area is partitioned with fixed parts such as protective fences, and then a partition is created in which an opening and a movable part that opens and closes the opening are installed in part of the partition to allow workers to access the operating area, i.e., a partition that allows workers to enter the operating area. In the partitioning system, a control system is constructed to monitor the movable part and, based on the monitoring results, control the equipment operating in the operating area to prevent harm to humans. In such a partitioning system, a safety switch that monitors the opening and closing of the movable part is installed in the area of ​​the opening where the movable part is installed.

[0003] The safety switch consists of a switch body located on the fixed part of the compartment and an actuator located on the door that constitutes the movable part of the compartment. The safety switch functions to maintain the operating area in a safe state by detecting and outputting a signal when the door, which is a movable part, is opened. The entire compartment system controls the devices within the operating area in accordance with the output from the safety switch to ensure that they do not pose a risk to humans. By configuring the system to, for example, stop the devices within the operating area or slow down their operating speed in accordance with the output from the safety switch, safety measures are taken for the environment in which the devices operate.

[0004] Patent Document 1 discloses a safety switch with a lock pin mechanism as one type of safety switch. The safety switch with a lock pin mechanism has an actuator bolt installed in a compartment fixing portion and a switch body installed in the door, with a lock pin attached to the switch body. The actuator bolt and the switch body are positioned relative to each other when the door is closed. In the lock pin mechanism, the lock pin mechanically engages with the actuator bolt, thereby forming 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 that can detect when the safety switch with a lock pin mechanism is in a locked state, and outputs an output indicating that the switch is not in the locked state at least when the switch is not in the locked state. By closing the door and locking the lock pin mechanism, the open / close door in the closed state is fixed in a state integrated with the compartment fixing portion. Conversely, by disengaging the lock pin from the actuator bolt, the 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 the switch body including the electromagnet is installed on a fixed part of the compartment, such as a safety fence. The door is locked when the electromagnet is driven and attracts the actuator magnetized member. The safety switch is equipped with a display unit that displays the safety status of the operating area.

[0006] The safety switch with an electromagnetic locking mechanism in Patent Document 2 has a locking lever that the worker operates to prevent the worker 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 worker 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 the area is safe as long as the "door closed" signal is 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 consisting 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, 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, causing the monitoring sensor to generate a door signal including a first status signal indicating "the door is open" or a second status signal indicating "the door is closed." [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Japanese Patent Application Publication No. 2019-183541 [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 that use safety switches, the safety switches are installed near openings through which people enter and exit for work or other purposes. For this reason, the safety switches can be a nuisance to workers. For example, placing the safety switch on a fixed section outside the work area has the advantage that the display of the safety switch can be easily seen by workers outside the work area. However, the safety switch protrudes from the fixed section regardless of the position of the door, which can be a nuisance to workers. Conversely, placing the safety switch inside the work area eliminates the problem of reduced workability due to the safety switch protruding from the fixed section, but reduces workability when the door is opened. More specifically, when the safety switch is placed inside the work area, the switch main body needs to be located near the actuator installed on the door when the door, which is a movable part of the compartment, is closed. For this reason, the switch main body is positioned so as to occupy the area that functions as the door opening when the door is open. 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 the safety switch may get in the way when the movable part is opened, i.e., when performing work through the door opening. Furthermore, if the safety switch is located inside the operating area, because the safety switch is located in the opening area, for example, if the area of ​​the opening of the opening door 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] SUMMARY OF THE INVENTION An object of the present invention is to provide a safety switch with an electromagnetic locking mechanism that can prevent the switch from interfering with an operator. [Means for solving the problem]

[0011] The above technical problems are basically solved by the present invention as follows: A safety switch comprising: an actuator having a magnetized member on which an attracted surface is formed; and a switch body having an attracting surface corresponding to the attracted surface, The switch body includes: a detection unit that detects whether the actuator is within a predetermined range relative to the switch body; an electromagnet having the attraction surface formed on the front side; one or more control boards that apply a locking current to the electromagnet so that the attracting surface and the attracted surface are attracted to each other; a housing provided on a rear side of the electromagnet and accommodating the one or more control boards; The one or more control boards include: receiving a lock signal for causing the lock current to flow; outputting a safety signal based on the detection by the detection unit; the suction surface constitutes the front surface of the switch body; This is achieved by providing a safety switch characterized in that in a first state in which the attracting surface and the attracted surface of the magnetized member are in contact, the total length of the magnetized member and the switch body in a direction perpendicular to the attracting surface is greater than the dimension of the housing in any direction parallel to the attracting surface.

[0012] According to the present invention, since the circuit 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 appears small when viewed from outside the compartment, i.e., from the outside. That is, since the circuit board housing portion of the switch body, which is 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 appears 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 explanation 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 locking mechanism. [Figure 2] FIG. 2 is a cross-sectional view taken along line II-II in FIG. [Figure 3] 1 is a diagram illustrating 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. [Figure 5] 10 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] FIG. 6 is a longitudinal cross-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, as viewed obliquely from behind. [Figure 11] This is an oblique view of the safety switch installed in the door opening frame of the protective fence and the door frame of the opening and closing door, viewed from the outside of the opening and closing door. [Figure 12] 10A and 10B are diagrams for explaining the effects of the arrangement of the display unit of the safety switch according to the embodiment. [Figure 13] FIG. 2 is a block diagram for explaining the 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. 10 is a diagram for specifically explaining the display mode of the display. [Figure 17] FIG. 10 is a diagram for explaining a preferred 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 longitudinal sectional view of the 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 due to the application of a compressive force. [Figure 21] 10A and 10B are diagrams 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, where (I) shows the standby state of the actuator when the door is open, (II) shows the state in which the attracted surface advances 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] 20A and 20B are diagrams 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. [Figure 23] This figure is a bottom view of the switch body as seen from the direction of looking at the attraction surface, and is intended to explain 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 on part of the cylindrical outer surface of the yoke portion in the switch body included in the embodiment. [Figure 24] This is 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 the 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). [Figure 25]FIG. 10 is a diagram for explaining that 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 seen 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 diagram showing a schematic representation of the installation structure of a switch body installed in a door opening frame. [Figure 28] FIG. 28 is a schematic diagram corresponding to FIG. 27 for explaining a first modified example of the installation structure of the switch body. [Figure 29] FIG. 28 is a schematic diagram corresponding to FIG. 27 for explaining a second modified example of the installation structure of the switch body. DETAILED DESCRIPTION OF THE INVENTION [Example]

[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 a compartment system 1, which includes an opening / closing door and a protective fence equipped with a safety switch with an electromagnetic locking mechanism according to an embodiment of the present invention. FIG. 2 is a cross-sectional view taken along line II-II in FIG. 1. In the figure, reference character PF denotes a protective fence, and reference character PD denotes an opening / closing door. FIG. 1 is an explanatory diagram of the compartment system 1 as viewed from outside the operating area S defined by the compartment system 1. The compartment system 1 comprises a protective fence PF as a fixed compartment part, a door PD constituting a movable part that is movable relative to the fixed compartment part, and a safety switch 100. The compartment system 1 maintains the operating area S in a safe state by restricting the operation of devices within the operating area S based on a safety-related output output from 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 compartment part of the compartment system 1 that defines the operating area S where the devices operate. An opening in which the door PD constituting a movable part relative to the fixed compartment part 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 that constitutes the movable part, and the door PD is attached to the vertical frame portion 2a of the door opening frame 2 via the plurality of hinges 4. In other words, the door PD is a single-wing 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 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 door PD in a closed state, with the door frame 6 constituting the door PD in contact with and positioned against the door stopper 110. In FIG. 2, the operating area S, defined by the safety fence PF and the opening / closing door PD, is the area located to the right of the safety fence PF and the door PD on the page of FIG. 2. The safety switch 100 is disposed on the operating area S side relative to the door PD in a closed state. By disposing the safety switch 100 so that it is located on the operating area S side relative to the door PD when the door PD is closed, the safety switch 100 is disposed within the operating area S. Referring to FIG. 2, the safety switch 100 is comprised of a switch main body 102 and an actuator 104. The switch main body 102 is fixed to the surface of the upper horizontal frame portion 2b of the door opening frame 2 on the operating area S side via a first bracket 106. The switch main body 102 includes 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 Fig. 2 shows arrows X, Y, and Z indicating three mutually orthogonal directions, which correspond to the arrangement posture of the safety switch 100, as will be described later.

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

[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 modification, they may have a U-shaped or L-shaped cross section.

[0020] The door PD relates to the opening and closing door described in Patent Document 2. Meanwhile, 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, which is 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] An embodiment of the present invention will be described below based on a typical example in which the present invention is applied to the door PD disclosed in FIGS. 1 and 2. FIG. 4 is a substantial front view of the actuator 104 included in the safety switch 100, illustrating the front shape of the actuator 104. The actuator 104 is mainly composed of an iron piece 120, which is a magnetizable member, and includes a plastic molded part 122, an actuator communication unit 124, and a mounting bracket 126. The iron piece 120 is circular in front view and has an attracting surface 130a and an attracting surface 120a on its front side. 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 that is 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 plane 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). When the door PD is closed, the relative positional relationship between the actuator 104 and the switch main body 102 is such that the actuator 104 is located on the surface of the door frame 6 facing the operating area S. That is, when the door PD is closed, 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. On the other hand, the switch main 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 of the actuator 104 to the door PD will be described in detail based on the arrangement example shown in FIG. 2. As described above, the actuator 104 is fixed to the upper frame portion 6a of the door frame 6. In this embodiment, the pair of mounting brackets 126 of the actuator 104 are fixed so that the mounting holes are aligned horizontally, i.e., 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, which is circular in front view and included in the actuator 104. In the installation example shown in FIG. 2, the actuator 104 is fixed to the door frame 6 with the direction of the height Ha aligned with 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 rectangular cross-section door frame 6 (FIG. 2). When installed on the door frame 6, a portion of the actuator 104 may protrude into the interior of the door frame 6, i.e., into the transparent board 8, but it is desirable for this protrusion to be as small as possible. This reduces the interference caused by the presence of 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 mentioned above, electromagnetic locking mechanisms for safety switches have historically been developed based on the technical concept of lock pin mechanisms. The design concept of the safety switch 100 with an electromagnetic locking mechanism of this embodiment will now be described. Generally speaking, the role of a safety switch is to maintain a safe environment in the operating area where the operating devices are located. This is achieved by detecting whether the door is open or closed. The role of the door locking function is to continue operating the devices in the operating area. Therefore, it can be said that the door locking function is sufficient if it can continue operating the devices in the operating area. In other words, the basic requirement for the door locking function of a safety switch is to prevent the inadvertent opening of the door while the device is operating. This is because if the door is inadvertently opened, the safety switch's function of maintaining a safe environment in the operating area restricts the operation of the devices in the operating area. 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 locking function of a safety switch has been designed to contribute to maintaining a safe operating environment. For this reason, electromagnetic locking mechanisms have employed electromagnets with a magnetic force strong enough to prevent the door from opening even with a relatively strong operating force. However, considering that the role of the door locking function is to keep the device operating rather than maintaining a safe environment, the magnetic force of the electromagnet employed in a safety switch with an electromagnetic locking mechanism may be the same as conventional electromagnets, or it may be weaker. When an operator attempts to open the door PD, the operating force required to open the door PD must be at least strong enough to prompt the operator to ask, "Are you opening the door PD as intended?" This can prevent the door from being opened accidentally. If the electromagnet requires a certain operating force to confirm the operator's intention to open the door PD, the door PD can be prevented from being opened accidentally without requiring a greater operating force.

[0025] Therefore, optionally, the magnetic force of the electromagnet 130 may be made weaker than conventionally. For example, if the door PD has an operating part such as a doorknob, the door latch is released when an operating force for turning the doorknob is applied to the doorknob, but the electromagnet 130 has a magnetic force at least stronger than the operating force required to release the door latch. This can deter workers from opening the door PD and prevent accidental opening of the door PD. This can also prevent unexpected interruptions to the operation of the device that may occur due to accidental opening of the door PD.

[0026] Referring to FIG. 5, the switch body 102 has a screw hole 130c as an attachment 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 protrusion 130b that protrudes outward from the center of the attraction surface 130a, and the screw hole 130c is provided in the protrusion 130b. Explaining 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 a first bracket 106 having an L-shaped cross section (FIG. 2). Explaining the arrangement example of FIG. 2, the protrusion 130b is positioned to protrude from the upper part of the electromagnet 130, and the flat top surface of the protrusion 130b forms a mounting surface, and the screw hole 130c is provided in the mounting surface. This mounting surface may also be formed on the side surface of the electromagnet 130.

[0027] For example, FIG. 5 illustrates arrows X, Y, and Z indicating three mutually orthogonal directions. The directions indicated by the arrows X, Y, and Z correspond to the positioning orientation of the safety switch 100, and are referred to as the X-axis direction, the Y-axis direction, and the Z-axis direction, respectively. The Y-axis direction indicates the normal direction of the attracting surface 130a of the electromagnet 130. The Z-axis direction indicates the direction perpendicular to the Y-axis direction, parallel to the attracting surface 130a, and in which the protrusion 130b protrudes relative to the center of the attracting surface 130a. The X-axis direction indicates the direction parallel to the attracting surface 130a and perpendicular to the Z-axis. As shown in FIG. 2, the safety switch 100 of this embodiment is positioned so that the attracting surface 130a faces the door PD in the closed state, and therefore the normal direction of the door PD in the closed state coincides with the Y-axis direction. Furthermore, the safety switch 100 of this embodiment is disposed so that the direction in which the protrusion 130b protrudes relative to the center of the attraction 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. Therefore, in this embodiment, the extension directions of the upper frame portion 6a and the upper horizontal frame portion 2b coincide with the X-axis direction, and the direction toward the operating region S with respect to the door PD, i.e., the depth direction of the operating region S, coincides with the Y-axis direction. Note that in the following description, the direction from the door PD in the closed state toward the attraction surface 130a in the Y-axis direction may be referred to as "rear" and the opposite direction as "forward," and the direction from the attraction surface 130a toward the protrusion 130b in the Z-axis direction may be referred to as "upward" and the opposite direction as "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 in 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 forms one end face on the front side in the Y-axis direction. The attraction surface 130a forms the main part of the front end face of the switch body 102. Specifically, one end face of the switch body 102 is formed 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 accommodating portion 132 for accommodating a board, and a display unit 142 that displays a signal corresponding to 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, i.e., on the opposite side of the attracting surface 130a in the Y-axis direction, and this connection portion connects the electromagnet 130 to the housing Hg. The board accommodating portion 132 is located on the opposite side of the attracting surface 130a of the electromagnet 130 in the Y-axis direction. In other words, the board accommodating portion 132 is located behind or on the back side of the electromagnet 130. Therefore, the dimensions of the entire switch body 102 in the X-axis direction and the Z-axis direction are unlikely to be larger than the dimensions of the electromagnet 130 in the X-axis direction and the Z-axis direction. The display unit 142 is located on the opposite side of the housing Hg from the attracting surface 130a of the electromagnet 130 in the Y-axis direction. 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, compared to other switch bodies that require a similar capacity, the area that the switch body 102 occupies in the opening formed in the door opening frame 2 tends to be smaller when viewed from the front.

[0030] FIG. 6 is a front view of the switch body 102 as viewed from the front. The normal to the plane 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, when viewed from the front, the ratio of the area occupied by the housing Hg to the area occupied by the attraction surface 130a is small.

[0031] As shown in FIG. 6 , when viewed from the front, the area occupied by the housing Hg is larger on the side of the center of the suction surface 130a where the screw holes 130c are provided than on the side of the center of the suction surface 130a where the screw holes 130c are provided. In other words, when viewed from the front, most of the housing Hg is located above the center of the suction surface 130a. When the switch main body 102 is fixed using the screw holes 130c, a dead space is generated between the largest dimension of the suction surface 130a in the X-axis direction and the door opening frame 2 to which the switch main body 102 is attached. By utilizing this dead space as an area to provide the housing Hg, workability through the door opening frame 2 is less likely to be reduced. Therefore, by configuring the housing Hg so that the area occupied by the housing Hg in the front view is larger on the side of the center of the suction surface 130a where the screw holes 130c are provided, workability through the door opening frame 2 in which the switch main body 102 is located is ensured.

[0032] FIG. 7 is a side view of the switch body 102. The switch body 102 has a board accommodating portion 132 on the opposite side of the electromagnet 130 from the attracting surface 130a (FIG. 8). As described above, reference symbol Hg denotes the housing of the board accommodating portion 132. A connector coupling portion 144 is provided on the rear end face 134 of the board accommodating portion 132, on the side opposite to the attracting surface 130a in the Y-axis direction (FIG. 7 and FIG. 8). The rear end face 134 is also the end face of the switch body 102 opposite to the attracting surface 130a. The connector coupling portion 144 extends in the Y-axis direction away from the attracting surface 130. By providing the connector coupling portion 144 on the end face 134 of the board accommodating portion 132, it is not necessary to arrange the cable connected to the connector coupling portion 144 around the switch body 102. Furthermore, because the connector coupling portion 144 is disposed on the rear end surface 134 of the circuit board accommodating portion 132, at least the portion of the cable connected to the connector coupling portion 144 near the connector coupling portion 144 is located behind the switch main body 102. This reduces the risk that the cable will reduce visibility of the display unit 142 from the front. Furthermore, by routing the cable connected to the connector coupling portion 144 behind the switch main 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 working through the door opening frame 2 is less likely to be reduced.

[0033] Fig. 8 is a vertical cross-sectional view of the switch body 102 cut along the Z-axis. 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, by forming a part of the yoke portion Yk (FIG. 24) of the electromagnet 130, which will be described later, into a raised shape, the protrusion 130b is configured by this raised shape. In the arrangement example shown in FIG. 2, the protrusion 130b is attached so as to be positioned on top, but it is also possible to attach the switch main body 102 so that the attachment portion 103b is positioned 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 thread into these two screw holes 130c (Figure 2).

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

[0037] As described above, the switch body 102 has at least a display unit 142 (FIGS. 2, 5, and 7) that displays information corresponding to the safety-related output output by the switch body 102. The display unit 142 is provided in a position that is visible from the side of the switch body 102 opposite to the side on which the screw holes 130c serving as mounting portions are located. In other words, the display unit 142 is provided in a position that is visible from the side on which the mounting surface formed by the top surfaces of the protrusions 130b is not present. When the switch body 102 is fixed to the door opening frame 2, the screw holes 130c are positioned so that they face outward from the opening formed in the door opening frame 2. Therefore, the side opposite to the side on which the screw holes 130c are provided faces inward of the opening. In the example of FIG. 2, the switch body 102 is fixed to the upper horizontal frame portion 2b of the door opening frame 2, so that the direction from the opening toward the outside is upward. Furthermore, since the inside of the opening of the upper horizontal frame portion 2b faces downward, the side 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. However, if the switch body 102 is fixed to the frame portion of the door opening frame 2 opposite the side where the hinge 4 is provided (the frame portion on the right side in FIG. 1 ), the display unit 142 is located on the left side of FIG. 1 . By providing the display unit 142 on the side opposite the screw hole 130c, the display unit 142 faces the side of the door opening frame 2 opposite the frame portion to which the switch body 102 is attached, i.e., the inside of the opening. When looking into the operating area S from the outside of the door PD having the transparent board 8, the transparent board 8 is located inside the opening, so the switch body 102 can be seen from inside 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 coupling portion 144, and this second board Cb(2) has a plurality of indicator lights 150 (FIG. 8) of different colors, specifically a plurality of LED elements, mounted on the front of the lower portion. The plurality of indicator lights (LED elements) 150 constitute the light source of the display unit 142. The display unit 142, which is disposed on a surface that allows the switch body 102 installed in the operating area S to be seen from the outside, has the well-known function of displaying the operating state of the switch body 102 in distinguishable colors.

[0039] 8, in the substrate accommodating section 132, a limited illumination space Ls is formed by a first substrate Cb(1) whose plate surface extends in the front-to-rear direction, i.e., along the Y axis, and a second substrate Cb(2) whose plate surface extends along the Z axis. Light from LEDs 150 mounted on the second substrate Cb(2) is emitted toward this limited illumination space Ls, and as a result, is displayed through a light-transmitting material that constitutes part of the display unit 142 and part of the housing Hg of the substrate accommodating section 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 Figs. 11 and 12. Fig. 11 is a view of the switch main body 102 viewed 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 operator's eye.

[0041] In FIG. 12, reference numeral 142-1 denotes a display unit located proximal to the adhesive surface 130a of the switch body 102. That is, the distance D-1 in the Y-axis direction between the adhesive surface 130a and the display unit 142-1 is relatively small. Reference numeral 142-2 denotes a display unit located distal to the adhesive surface 130e. The distance D-2 in the Y-axis direction between the adhesive 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 can be seen that arranging it distal to the adhesive surface 130a rather than proximal to it improves visibility when viewing the display unit 142 from outside through the door PD. Preferably, the display unit 142 is located rearward of a midline Imd that is half the length of the overall length L (FIG. 5) of the switch body 102 in the Y-axis direction. That is, it is preferable to place the display unit 142 at a position farther away from the suction 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 of both sides of the switch body 102 in the Z-axis direction. 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 in the Y-axis direction toward the attraction surface 130a. In other words, the display unit 142 has a surface that is inclined toward the front, which is outside the operating area S of the door PD. By tapering the display unit 142 toward the attraction surface 130a, the display unit 142 is easier for the operator to see.

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

[0044] The main body Cb (main body) of the first substrate Cb(1) is equipped with a control circuit that generates a drive signal for the electromagnet 130, a power supply circuit, a communication circuit with the actuator 104, etc. On the other hand, the second substrate Cb(2) is equipped with an indicator light control circuit, etc.

[0045] Referring to FIG. 9 , in the board accommodating portion 132, the first board Cb(1), whose plate surface extends along the Y-axis, has a pair of elongated board extensions Cb(1ex) extending in the Y-axis direction from a main body Cb (main body) located in the board accommodating portion 132 and equipped with a control circuit and the like, to the vicinity of the attraction surface 130a. The pair of board extensions Cb(1ex) are located on both sides of the protrusion 130b in the X-axis direction. By positioning the pair of board extensions Cb(1ex) on both sides of the protrusion 130b, it is possible to prevent the presence of the board extensions Cb(1ex) from increasing the height dimension of the switch main body 102 in the Z-axis direction. Furthermore, a portion of the board extensions Cb(1ex) is positioned so as to overlap with the electromagnet 130 when viewed in the Z-axis direction. Therefore, the presence of the board extensions Cb(1ex) can reduce increases in the dimensions of the switch main body 102 in the Z-axis direction and the X-axis direction.

[0046] Of the pair of circuit board extensions Cb(1ex), one of the circuit board extensions Cb(1ex) has a sensor side coil (antenna coil) 152 mounted on its tip (FIG. 9). The sensor side coil 152 constitutes a detector that detects whether 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 circuit board extensions Cb(1ex), the sensor side coil 152 can be positioned close to the attraction surface 130a in the Y-axis direction. As a result, the detection capability of the sensor side coil 152 can be improved. As is well known, the sensor side coil 152 is positioned corresponding to the actuator communication unit 124 of the actuator 104. In this case, to enable 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. Therefore, a portion of the housing Hg is present on the surface of the switch body 102 facing the actuator 102, in addition to the attraction surface 130a. In this embodiment, as described above, by arranging a part of the housing Hg in the dead space, it is possible to maintain workability through the door opening frame 2 in which the switch main body 102 is arranged.

[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 movement of the door PD, as shown in FIG. 17, and then the iron piece 120 overlaps the attracting surface 130a of the switch body 102. The diameter D1 (FIG. 4) of the iron piece 120 (attached surface 120a) is designed to be larger than the diameter D2 of the attracting surface 130a. Based on the state in which the iron piece 120 is properly overlapped on the switch body 102, that is, the proper 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 attracting surface 130a of the iron piece 120. As a result, even if the switch body 102 and / or the actuator 104 undergo an allowable relative displacement, the switch body 102 can fix the actuator 104 with a predetermined attraction force.

[0048] When the door PD is closed, i.e., 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 transmitting circuit 206. The transmitting circuit 206 is connected to a sensor-side coil (antenna coil) 152. The sensor-side coil 152 is connected to a receiving circuit 208. The receiving 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 transmitting circuit 206, causing the sensor-side coil 152 to supply a wireless signal 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 wireless signals from the actuator communication unit 124 via the sensor-side coil 152 and the receiving 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 its 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 then 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 the distance d (FIG. 17) between the switch main 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 less than a threshold, i.e., whether the actuator 104 is within a predetermined range relative to the switch main 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 constitute a detection unit that detects whether the actuator 104 is within a predetermined range relative to the switch main body 102. Note that the strength of the wireless signal may be used directly to detect the position of the actuator 104 instead of the distance d. The demodulation unit 212a of the first MCU 202 and the demodulation unit 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 two conditions are met, 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, the determination result may be either whether both conditions are met, or whether at least one of the conditions is not met. Similarly, the safety determination circuit 214b of the second MCU 204 determines whether two conditions are met, 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 its own determination result and the determination result of the second MCU match, the safety determination circuit 214a of the first MCU 202 outputs a safety-related output determining that the actuator 104 identified as the predetermined actuator is within a predetermined range relative to the switch main body 102, i.e., that the door PD is closed. Similarly, when its own determination result 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 within a predetermined range relative to the switch main body 102, i.e., that the door PD is closed. Note that in this embodiment, as will be described later, the first MCU 202 and the second MCU 204 output safety-related outputs via OSSDs (Output Signal Switching Devices) when a condition related to a signal input via the input circuit 220 is also satisfied. However, the safety-related outputs may also 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 main 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 it is also possible to configure the safety judgment circuits 214a, 214b to only estimate the distance d, and output the judgment result of whether the distance d is equal to or less than a threshold value to the other safety judgment circuit without making a judgment regarding the identification of the actuator 104.

[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. Other devices capable of outputting a safety-related output are connected to the first safety input unit 222 and the second safety input unit 224. That is, 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 have one terminal for outputting a safety-related output of the other device connected to the first safety input unit 222, and another terminal for outputting a safety-related output of the other device 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, receives a lock signal for controlling the lock mechanism output from the external control device, and outputs the 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. Based on the lock signal input via the lock input unit 226, the second MCU 204 drives the electromagnet 130 to attract the electromagnet 130 to the iron piece 120 of the actuator 104. That is, the door PD is locked by magnetic force in accordance with the signal input via the lock input unit 226. Note that 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 other conditions are satisfied in addition to the signal input via the lock input unit 226 being an ON signal. For example, the determination of the safety determination circuits 214a and 214b described above may be the condition for driving the electromagnet 130. In this case, the electromagnet 130 is driven when it is determined that a predetermined actuator 104 is within a predetermined range relative to the switch body 102, thereby improving the reliability of maintaining the door PD 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 switching devices 230. The first MCU 202 and the second MCU 204 each generate a safety signal, with the first MCU 202 outputting a safety-related output as a safety signal via the first OSSD 230a, and the second MCU 204 outputting a safety-related output as a safety signal via the second OSSD 230b. 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 constitute the compartment system 1.

[0056] The first OSSD 230a and the second OSSD 230b are configured, for example, by PNP transistors. When the PNP transistor is turned ON, the output terminal is connected to the positive 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] An OSSD monitoring circuit 232 may be connected to each of the first OSSD 230a and the second OSSD 230b. 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, each of the first OSSD 230a and the second OSSD 230b periodically transitions its 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 while the ON signal is being output, 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 abnormal.

[0058] Note that if the OSSD monitoring circuit 232 cannot detect a very short OFF period and the ON signal continues, this may be due to, for example, a short circuit between the output terminal and the positive power supply. In this case, the safety determination circuits 214a and 214b output control signals to the first OSSD 230a and the second OSSD 230b, respectively, to cause them to output OFF signals. As a result, either the first OSSD 230a or the second OSSD 230b, whichever is operating normally, outputs an OFF signal. Note that 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 external devices to which the safety-related output is output do not react to the OFF transition.

[0059] The power supply circuit 240 is a DC-DC converter that receives DC +24V and 0V from an external source and generates DC voltages such as DC +10V, +5V, and +3.3V. The power supply circuit 240 supplies power to all circuits requiring power, such as the control circuit 200, the sensor-side coil 152, and the display unit 142. If the voltage supplied from the external power source or the voltage output from the power supply circuit 240 is outside a predetermined range, the control circuit 200 and other components may not operate normally. Therefore, the power supply monitoring circuit 242 determines whether the voltage supplied from the external power source is within a predetermined range and whether the voltage output from the power supply circuit 240 is within the predetermined range, and outputs the determination results to the first OSSD 230a and the second OSSD 230b. When the first OSSD 230a and the second OSSD 230b receive a determination result indicating that the power supply circuit 240 is not operating normally, they each turn off the safety-related output, regardless of the control signal output from the control circuit 200. When the first OSSD 230a and the second OSSD 230b receive a judgment result indicating that the power supply circuit 240 is operating normally, they each output a safety-related output depending on the 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 status 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 "Indicator Light" column in FIG. 16 indicates the light emission pattern of the display unit 142, which is controlled based on the display status signal supplied to the display control unit 252. The "Status" column is further divided into "OSSD," "Safety Input," "Lock Control Input," and "Actuator." The "OSSD" column indicates whether the safety-related output output to an external control device via the first OSSD 230a and the second OSSD 230b serving as the switching device 230 is ON or OFF. The "Safety Input," "Lock Control Input," and "Actuator" columns indicate the judgment items used to determine whether the safety-related output output via the switching device 230 should be ON or OFF. The "Safety Input" column indicates whether the safety-related output input via the first safety input unit 222 and the second safety input unit 224 is ON or OFF. The "Lock Control Input" column indicates whether the lock signal input from an external control device via the lock input unit 226 is ON or OFF. The column "Actuator" indicates whether or not 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 output via the switching device 230 is turned ON when the safety-related output input via the first safety input unit 222 and the second safety input unit 224 is ON, the lock signal input via the lock input unit 226 is ON, and the actuator 104 is detected. In this state, the display unit 142 illuminates green. When the actuator 104 is not detected, the safety-related output output via the switching device 230 is turned OFF, regardless of the safety-related output or lock signal input via the first safety input unit 222 and the second safety input unit 224, and the display unit 142 illuminates red. The safety switch 100 of this embodiment detects whether the actuator 104 is within a predetermined range relative to the switch body 102 in order to maintain a safe environment in the operation area S. When the actuator 104 is not detected, the door PD is not closed and the operation area S is not maintained as a safe environment. Therefore, the safety-related output output via the switching device 230 is turned 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 output via 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, compared to the detection of the actuator 104, it is difficult for an operator to grasp the state of the safety-related output and the lock signal input via the first safety input unit 222 and the second safety input unit 224. More specifically, whether the actuator 104 is detected has a certain correlation with whether the door PD is closed or not. Therefore, when the actuator 104 is not detected and the safety-related output output from the switch main body 102 via the switching device 230 is OFF, the operator can easily identify the cause. In contrast, with regard to the safety-related output and the lock signal input via the first safety input unit 222 and the second safety input unit 224, an operator can visually check whether the corresponding cables are connected, but it is difficult to visually grasp the state of the signals supplied via the cables. 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, because 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 turns ON, and the light-emitting pattern of the display unit 142 lights up green. In this case, the case in which the light-emitting pattern of the display unit 142 is "orange" or "flashing orange," as shown in FIG. 16 , does not exist.

[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 attracting 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 described in detail. The second MCU 204 supplies a test current to the electromagnet 130 and monitors the current flowing through the electromagnet 130. (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 locking current supplied to the electromagnet 130 to maintain the door PD in a closed state, i.e., to establish the locked state of the safety switch 100. If a current with the same value as the locking current were used for the test, the electromagnet 130 would attract the iron piece 120 with an attractive force sufficient to maintain the door PD in a closed state even when the lock signal is not ON, which would hinder the operation of opening the door PD and reduce the worker's workability. For this reason, the worker's workability can be maintained by setting the value of the test current to a value smaller than the value of the locking current, particularly to a weak value at which the electromagnet 130 exerts almost no attractive force.

[0067] Fig. 18(II) shows the monitoring current flowing through the electromagnet 130 in response to the rectangular wave inspection current of 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 rectangular wave inspection current of 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] If the time from when the supply of the inspection current begins 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 began 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 began to the electromagnet 130 is illustrated as the inspection confirmation timing. The value of the monitoring current flowing through the electromagnet 130 at the inspection confirmation timing when 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 when the distance d2 between the attracting surface 130a and the attracted surface 120a is equal to or less than the threshold is the second monitoring current value I2 shown in (III) of FIG. 18. 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 than 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 the level of responsiveness of the monitoring current flowing through the electromagnet 130, the magnitude of inductance related to the level of responsiveness, and the length of the distance d2 between the attracting surface 130a and the attracted surface 120a, which is related to the magnitude of inductance. More specifically, a current threshold is set between at least 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 can be determined. Whether the distance d2 is greater than or equal to the threshold 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.

[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 a door PD in which the door frame 6 is attached parallel to the door opening frame 2 to which the switch body 102 is attached in the manner shown in FIG. 2. Therefore, the normal direction of the door frame 6 (PD) coincides with the Y-axis direction, which is the normal direction of the attracting surface 130a of the electromagnet 139 provided in the switch body 102. Furthermore, in the actuator 104 shown in FIG. 19, the normal direction of the attracting surface 120a of the iron piece 120 provided in the actuator 104 coincides with the Y-axis direction. Although the actuator 104 may have a structure in which the iron piece 120 is fixed relative to the mounting bracket 126, the iron piece 120 in the actuator 104 shown in FIG. 19 is movable relative to the mounting bracket 126.

[0070] Referring to Figure 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 a through-hole 126a in the center of its 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 in front view in the center of its attracted surface 120a. The movable pin 320 inserted into the through-hole 126a of the mounting bracket 126 is movable in the axial direction of the movable pin 320 relative to the mounting bracket 126. This configuration constitutes a mechanism that moves 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 another end flange 322b that both extend radially outward and circumferentially. 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, movable pin 320, and sleeve 322 move relative to the mounting bracket 126.

[0072] The movable pin 320 and sleeve 322 are movable in the axial direction of the movable pin 320, with the outer peripheral surface of the sleeve 322 guided by the through hole 126a. The sleeve 322 has a guide function that guides the axial movement of the movable pin 320. The movable pin 320 can also swing together with the sleeve 322 within the through hole 126a. In other words, the diameter of the sleeve 322 is smaller than the diameter of the through hole 126a, and the sleeve 322 is loosely fitted within the through hole 126a. This configuration forms a swing mechanism that swings the attracted surface 120a.

[0073] A compression coil spring 324 is provided between one end flange 322a of the sleeve 322 and the mounting bracket 126. The compression coil spring 324 constitutes a biasing means that biases the movable pin 320 and the attracted surface 120a in a direction toward 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 loaded and compressed state. As can be seen from FIG. 20(I), the compression coil spring 324 is a spiral spring with a trapezoidal shape in a side view, the diameter of which gradually decreases in the axial direction. This spiral-shaped compression coil spring 324 can assume a flat shape in a side view when compressed. Therefore, the range of movement of the movable pin 320 increases 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 compression coil spring 324 moves the iron piece 120 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 in Fig. 17. Note that examples of modified 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 explained later, the impact when the iron piece 120 overlaps with the attraction surface 130a of the electromagnet 130 due to the attractive force of the permanent magnet 120b is absorbed by the compression coil spring 324 and the cushion member 326.

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

[0078] FIG. 21 (II) illustrates a state in which the door PD is in the process of changing from an open state to a closed state, i.e., in the process in which an operator closes the door PD, and as a result the door PD is in the closed state, the actuator 104 approaches the attraction surface 130a of the electromagnet 130 provided in the switch main body 102. At this time, the electromagnet 130 is not driven. As shown in FIG. 21 (II), when the actuator 104 approaches the electromagnet 130, an attractive force of the permanent magnet 120b provided in the actuator 104 acts on the attraction surface 130a of the electromagnet 130. When this attractive force becomes greater than the spring force of the compression coil spring 324, the compression coil spring 324 begins to compress. Then, under the attractive 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, i.e., 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, along with the actuator housing 122, move in 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 described in (II). A 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, is equal to or less than the threshold value. That is, the actuator communication unit 124 determines that the actuator 104 is within a predetermined range relative to the switch body 102. In addition, in the state shown in 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 due to 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. However, the movement of the iron piece 120 toward the attracting surface 130a may be achieved by other means. For example, the iron piece 120 may move toward the attracting surface 130a due to inertia when the door PD is closed. Alternatively, the electromagnet 130 may be driven to generate an attractive force weaker than the attractive force required to maintain the door PD closed, and the iron piece 120 may move toward the attracting surface 130a due to the attractive force.

[0080] FIG. 22 is a cross-sectional view illustrating the state change of the actuator 104. (I) in FIG. 22 corresponds to (I) in FIG. 19, and shows the actuator 104 in a standby state. (II) in FIG. 22 illustrates the state when the iron piece 120 of the actuator 104 is in its maximum operating position, where it is fully advanced, i.e., when the movable pin 320 is displaced in its axial direction, i.e., the Y-axis direction, where it is in its maximum stroke position. This state can be achieved by the attractive force of the permanent magnet 320. (III) in FIG. 22 illustrates that when the iron piece 120 overlaps the attracting surface 130a under the attractive force of the permanent magnet 320, the iron piece 120 can swing so that the attracted surface 120a is parallel to the attracting surface 130a. The swing of the movable pin 320, i.e., the tilting of its axis Ax, establishes the parallel state between the attracted surface 120a and the attracting surface 130a.

[0081] As described above, the actuator communication unit 124 is disposed in the actuator housing 122 that surrounds the periphery of the iron piece 120 (FIG. 3). On the other hand, the sensor side coil 152 is disposed in the switch main 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 main 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 positioned close to each other in the switch body 102, magnetic flux leaking from the electromagnet 130 to the surrounding area 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 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, at least a portion of the sensor-side coil 152 provided near the electromagnet 130 overlaps the attracted surface 120a when viewed in the normal direction of the attracting surface 120a. The sensor-side coil 152 faces the coil provided in the actuator communication unit 124. This increases the likelihood of magnetic flux leakage, which affects the strength of the wireless signal received via the sensor-side coil 152. To reduce the effect of magnetic flux leakage on the wireless signal, the electromagnet of this embodiment has the 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. Although the core 140a and the yoke portion Yk may be formed separately, in this embodiment, the core 140a and the yoke portion Yk are formed integrally. Also, in this embodiment, the aforementioned protrusion 130b is formed as 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 main body 102 may be provided on the switch main body 102 in addition to the protrusion 130b, which is a part of the yoke portion Yk protruding radially outward.

[0083] The yoke portion Yk serves to improve the attractive force by transmitting magnetic flux emitted from the electromagnet 130. FIG. 24 is a cross-sectional view taken along line XXIII-XXIII in FIG. 23. The dashed arrows 190 in FIG. 24 indicate magnetic flux leaking from the electromagnet 130. In FIG. 24, reference numeral 140a denotes a core. A magnet wire is wound around the core 140a. In FIG. 24, a void 140b is depicted between the core 140a and the yoke portion Yk located on its outer periphery. As is well known, a magnet wire is located in the void 140b. The electromagnet 130 attracts the actuator 104, thereby forming a magnetic circuit between the electromagnet 130 and the actuator 104. The magnetic flux in the magnetic circuit is indicated by solid black arrows. 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 magnetic flux passing through the yoke portion Yk leaks outside the yoke portion Yk when the density of the passing magnetic flux is high. By providing the protrusion 130b on a portion of the yoke portion Yk, the cross-sectional area of ​​the yoke portion Yk where the protrusion 130b is provided in the circumferential direction is larger than that of the other portions in the circumferential direction. Therefore, the magnetic flux density of the yoke portion Yk where the protrusion 130b is provided in the circumferential direction is relatively lower than that of the other portions, thereby reducing magnetic flux leakage near the protrusion 130b.

[0084] The sensor side coil (antenna coil) 152 is disposed near the protrusion 130b. A preferred location for the sensor side coil 152 will be described in detail with reference to Fig. 23. If the periphery of the attracting surface 130a is divided into four regions by a first center line CL1 that passes through the center O2 of the attracting surface 130a and the center line of the protrusion 130b, and a second center line CL2 that passes through the center O2 and is perpendicular to the first center line CL1, then in the illustrated example, the sensor side coil 152 would be disposed in the first quadrant on one side of the protrusion 130b. Of course, the sensor side coil 152 may also be disposed in the second quadrant on the other side of the protrusion 130b. Furthermore, the sensor side coil 152 is positioned so that it is located closer to the adsorption surface 130a than 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 so that it is located closer to the adsorption surface 130a than 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] To explain the advantages of arranging the sensor-side coil (antenna coil) 152 near the protruding protrusion 130b, a comparative example electromagnet 400 shown in FIGS. 25 and 26 will be described. FIG. 25 is a view of the comparative example electromagnet 400 from the attracting surface 400a side. The yoke portion Yk has the same thickness in the circumferential direction. FIG. 26 is a cross-sectional view taken along line XXV-XXV in FIG. 25. In the figure, reference numeral 402 denotes a core. Referring to FIG. 26, by using the comparative example electromagnet 400 to attract the actuator 410, a magnetic circuit is formed between the actuator 410 and the electromagnet 400. The magnetic flux in the magnetic circuit is indicated by solid black arrows. In this magnetic circuit, magnetic flux leakage occurs around the yoke portion Yk. The magnetic flux leakage is indicated by dashed arrow 190.

[0086] When the sensor side coil (antenna coil) 152 is placed 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 that constitutes part of the yoke portion Yk is relatively thick, which makes it difficult for magnetic flux to leak near the protruding portion 130b. In this way, by arranging the sensor-side coil (antenna coil) 152 near the protruding portion 130b where magnetic flux is unlikely to leak (FIG. 23), the effect of magnetic flux leakage on the signal strength detected by the sensor-side coil (antenna coil) 152 can be reduced.

[0088] As described above, the protrusion 130b reduces the magnetic flux density at the portion where the protrusion 130b is provided. Generally, the magnetic attraction force of a magnet varies depending on the magnetic flux density at the surface that contacts the target. Therefore, the electromagnet 130 is shaped so that a gap Gp ( FIG. 24 ) is formed between the iron piece 120 and the protrusion 130b when the electromagnet 130 attracts the iron piece 120. The gap Gp allows the area of ​​the yoke portion Yk where the protrusion 130b is provided that contacts the iron piece 120 to be smaller than the cross-sectional area of ​​the portion where the protrusion 130b is located in the Y-axis direction. Thus, providing the protrusion 130b can suppress a decrease in the magnetic flux density at the portion that contacts the iron piece 120, thereby maintaining the magnetic attraction force of the electromagnet 130. In other words, the gap Gp effectively stabilizes attraction. The gap Gp can be formed by designing the relatively thick protrusion (protrusion 130b) so that it can be positioned at a position receding from the attraction surface 130a in the Y-axis direction (FIG. 24). Furthermore, 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 illustrating 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 then fixed to the first bracket 106 via this level adjustment member 350. FIG. 28 is a modification of FIG. 27, in which an intermediate metal plate 132a connected to the electromagnet 130 is interposed between the electromagnet 130 and the circuit board housing portion 132, and the switch body 102 is fixed to this intermediate metal plate 132a with screws. In this way, by providing an attachment portion for fixing the switch body 102 to the first bracket 106 forward of the housing Hg that forms the circuit board housing portion 132, 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 elongated in the front-to-rear direction, as shown in FIG. 28. FIG. 29 shows a modification of FIG. 27, in which at least the upper portion of the board accommodating portion 132 is formed of a metal housing 352, the switch body 102 is screwed to the metal housing 352 of the board accommodating portion 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 metal housing 352 that forms the board accommodating portion 132 and has an attachment portion improves the durability of the switch body 102 against impacts caused by the actuator 104 contacting the electromagnet. In the first modification shown in FIG. 28 and the second modification shown in FIG. 29, the board Cb may have a floating support structure or may be filled with resin.

[0090] Referring to the schematic diagram of FIG. 27 , the safety switch 100 is described. The length L of the switch body 102 in the Y-axis direction is greater than the diameter of the attracting surface 130a. When a constant current is applied to an electromagnet, the strength of the attracting force of the electromagnet is proportional to the number of turns in the coil. Therefore, to achieve a constant attracting force without increasing the diameter of the attracting surface 130a, the electromagnet 130 in this embodiment has a constant length in the front-to-rear direction. If there is a limit to the length of the entire switch body 102 in the front-to-rear direction, i.e., in the Y-axis direction, it becomes more difficult to form a housing behind the electromagnet 130. By configuring the switch body 102 so that the length L in the Y-axis direction is greater than the diameter of the attracting surface 130a, a housing Hg with a housing can be placed behind the electromagnet 130, thereby reducing the area occupied by the switch body 102 in the opening. 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 (compartment fixed part) PD Opening and closing door (moving part) 2 Door opening frame S Operation area surrounded by a protective fence 100 Example of safety switch with electromagnetic locking mechanism 102 Switch body 104 Actuator 120 Actuator iron piece (magnetized member) 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 comprising: an actuator having a magnetized member on which an attracted surface is formed; and a switch body having an attracting surface corresponding to the attracted surface, The switch body includes: a detection unit that detects whether the actuator is within a predetermined range relative to the switch body; an electromagnet having the attraction surface formed on the front side; one or more control boards that apply a locking current to the electromagnet so that the attracting surface and the attracted surface are attracted to each other; a housing provided on the rear side of the electromagnet and accommodating the one or more control boards; Equipped with The one or more control boards include: receiving a lock signal for causing the lock current to flow; outputting a safety signal based on the detection by the detection unit; the suction surface constitutes the front surface of the switch body; A safety switch characterized in that, in a first state in which the attracting surface and the attracted surface of the magnetized member are in contact with each other, the total length of the magnetized member and the switch body in a direction perpendicular to the attracting surface is greater than the dimension of the housing in any direction parallel to the attracting surface.

2. 2. The safety switch according to claim 1, The electromagnet is connected to the housing on the rear side.

3. 2. The safety switch according to claim 1, The housing further includes a display unit that indicates the operating state of the switch body.

4. 4. The safety switch according to claim 3, The switch body further includes an attachment portion for attaching the switch body to an installation location, A safety switch, wherein the display unit is provided at a position visible from the opposite side of the surface of the switch body where the mounting unit is located.

5. 5. The safety switch according to claim 4, A safety switch in which the display portion tilts forward.

6. 2. The safety switch according to claim 1, an attracting surface of the electromagnet is smaller than an attracting surface of the actuator; the detection unit has an antenna coil that exchanges wireless signals with an actuator coil provided in the actuator, A safety switch, wherein the antenna coil is provided at a position opposite the actuator coil in the first state.

7. 7. The safety switch according to claim 6, A safety switch, wherein the electromagnet is provided with a protrusion in the vicinity of a position where the antenna coil is provided, for reducing the effect on the antenna coil caused by driving the electromagnet.

8. 8. The safety switch according to claim 7, In the first state, the protrusion and the attracted surface face each other with a gap therebetween.

9. 2. The safety switch according to claim 1, The one or more control boards are a safety switch that passes a locking current through the electromagnet so that the attracting surface and the attracted surface are attracted to each other based on the detection result by the detection unit and the locking signal.

10. 2. The safety switch according to claim 1, A safety switch, wherein the electromagnet is formed with a mounting portion for mounting the switch body to an installation location.

11. 2. The safety switch according to claim 1, a metal member connected to the electromagnet; A safety switch, wherein the metal member is formed with a mounting portion for mounting the switch body to an installation location.

12. 12. The safety switch according to claim 11, The metal member is disposed between the electromagnet and the housing.

13. 2. The safety switch according to claim 1, A safety switch characterized in that, in the first state, the total length of the magnetized member and the switch body in a direction perpendicular to the attraction surface is greater than the diameter of the attraction surface.

14. 2. The safety switch according to claim 1, The switch body further includes an attachment portion for attaching the switch body to an installation location, a mounting surface of the mounting portion perpendicular to the suction surface; A safety switch in which the detection unit is arranged between the mounting surface and a plane that is in contact with the farthest end of the electromagnet in the normal direction of the mounting surface, and is also arranged between a plane formed by the attraction surface of the electromagnet and a plane formed by the back surface of the electromagnet.

15. 4. The safety switch according to claim 3, The one or more control boards include: a first substrate on which a control circuit for passing a locking current to the electromagnet is disposed; a second substrate electrically connected to the first substrate and having a light source for the display unit disposed thereon; , safety switch.

16. 2. The safety switch according to claim 1, The one or more control boards include: a first substrate on which an antenna coil is arranged to exchange wireless signals with an actuator coil provided in the actuator; the second board electrically connected to the first board and electrically connected to a cable via the rear surface of the housing; , safety switch.

17. 2. The safety switch according to claim 1, The one or more control boards include: a first substrate perpendicular to a plane defined by the attracting surface of the electromagnet; a second substrate disposed parallel to a plane defined by the attracting surface of the electromagnet and electrically connected to the first substrate; , safety switch.

18. 18. The safety switch according to claim 17, an antenna coil is disposed on the first substrate, the antenna coil transmitting and receiving wireless signals to and from an actuator coil provided in the actuator; the second board is electrically connected to the first board and is also electrically connected to a cable via the rear surface of the housing; , safety switch.

Images