Safety switch

Abstract

To secure visibility of a display part even when a switch body of a safety switch is arranged within a working area.SOLUTION: A safety switch (100) includes a switch body (102) including an electromagnet (130), and an actuator (104) to be attracted by the electromagnet (130). The switch body (102) has a front end face constructed by an attracting surface (130a) of the electromagnet (130). On a back face side of the electromagnet (130), a display part (142) is provided. The display part (142) displays a state of the safety switch (100).SELECTED DRAWING: Figure 5

Description

[Technical field]

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

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

[0003] The safety switch is composed of a switch body arranged in the fixed part of the compartment, and an actuator arranged in the opening and closing door that constitutes the movable part of the compartment. The safety switch detects and outputs when the door, which is a movable part, is opened, as a function for maintaining the operating area in a safe state, and the entire compartment system controls the devices in the operating area in accordance with the output from the safety switch so that they do not cause harm to the human body. For example, by configuring the system to stop the devices in the operating area or slow down the operating speed of the devices in accordance with the output from the safety switch, safety measures are taken for the environment in which the devices are operating.

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

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

[0006] The switch body disclosed in Patent Document 2 has an overall shape that is long in the direction of a first axis perpendicular to the normal of the adhesive surface. The display unit is disposed at a position spaced apart from the adhesive surface in the first axial direction. The surface on which the adhesive surface exists is called the "front surface," the opposite surface is called the "rear surface," and the two surfaces continuous with each side edge of the front surface and each side edge of the rear surface are called the "side surfaces." In the overall shape of the switch body, the adhesive surface is disposed at one end of the front surface. The display units are disposed at positions spaced apart from the adhesive surface in the first axial direction and on the two side surfaces. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] JP 2019-183541 A [Patent Document 2] Special Publication No. 2016-510382 Summary of the Invention [Problem to be solved by the invention]

[0008] As described above, in safety measures using a safety switch, the safety switch is installed near an opening through which a human body mainly enters and exits for work or other purposes. For this reason, the safety switch is an obstacle to workers. For example, when the safety switch is arranged on a partition fixing part outside the working area, there is an advantage that the display part of the safety switch can be easily confirmed by a worker outside the working area, but the safety switch protrudes from the partition fixing part to the outside regardless of the position of the opening and closing door, which is an obstacle to workers. Conversely, when the safety switch is arranged inside the working area, the reduction in workability caused by the safety switch protruding from the partition fixing part to the outside is eliminated, but when the workability is to be maintained when the opening and closing door is opened, it becomes difficult to confirm the display part of the safety switch. More specifically, when the safety switch is arranged inside the working area, when the opening and closing door as a movable part of the compartment is closed, the switch main body needs to be arranged near the actuator arranged on the opening and closing door. For this reason, the switch main body is arranged at a position that occupies an area that functions as an opening when the opening and closing door is opened. For this reason, the safety switch including the switch main body narrows the area of ​​the opening in which the movable part is arranged, and therefore the safety switch may get in the way when the movable part is opened, i.e., when performing work through the opening in which the movable part is installed. However, if the safety switch is arranged in a position that cannot be seen from the opening in order to facilitate work through the opening, visibility is reduced. Furthermore, if an attempt is made to maintain workability by reducing the amount of protrusion from the inner edge of the opening, the safety switch is hidden by the frame of the opening door, and visibility is reduced. Therefore, when the safety switch is arranged inside the operating area, it is difficult to achieve both workability when the opening door is opened and ease of checking the display part of the safety switch.

[0009] An object of the present invention is to provide a safety switch with an electromagnetic lock mechanism that can ensure visibility of a display unit even if the switch body of the safety switch is disposed inside the operating area. [Means for solving the problem]

[0010] The above technical problem is solved by the present invention. A safety switch in which a magnetized member having an attracted surface is disposed so as to be movable relative to a switch body, a detection unit that detects whether a relative position of the actuator is within a predetermined range with respect to the switch body; an electromagnet having an attracting surface formed on a front side thereof corresponding to an attracting surface of the actuator; a lock input unit that receives a lock instruction to lock the relative movement of the actuator; a drive control unit that drives the electromagnet so that an attraction surface of the electromagnet and an attracted surface of the actuator are attracted to each other based on the lock instruction received by the lock input unit; a safety control unit that generates a safety signal based on the detection by the detection unit; a display control unit that generates status information based on a detection result by the detection unit; This can be achieved by providing a safety switch including a display unit that is arranged laterally behind the electromagnet and displays the status information generated by the display control unit.

[0011] In the safety switch of the present invention, typically, the switch body is installed inside the operating area and fixed to the compartment fixing part so that the attraction surface faces the movable part. In the safety switch of the present invention, the display unit is disposed on the side surface on the rear side of the electromagnet that constitutes the front surface, so that the operator can easily check the display unit when looking into the operating area from the outside.

[0012] The effects and other objects of the present invention will become apparent from the following detailed description of preferred embodiments of the present invention. [Brief description of the drawings]

[0013] [Figure 1] FIG. 2 is a front view of a safety fence and a safety door equipped with a safety switch according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a cross-sectional view taken along line II-II in FIG. [Diagram 3]1 is a diagram for explaining a box-shaped device to which the present invention can be applied. [Figure 4] FIG. 2 is a perspective view of an actuator which is one element of the safety switch of the embodiment. [Diagram 5] 4 is a perspective view of a switch body, which is another element of the safety switch of the embodiment, as viewed obliquely from the front and obliquely from above. FIG. [Figure 6] 6 is a perspective view of the switch body shown in FIG. 5, as viewed obliquely from the front and from obliquely below. [Figure 7] FIG. 6 is a front view of the switch body shown in FIG. 5. [Figure 8] FIG. 6 is a side view of the switch body shown in FIG. 5. [Figure 9] 5 is a cross-sectional view of the switch body shown in FIG. 4. [Figure 10] 5 is a perspective view of the switch body shown in FIG. 4 with a housing removed. FIG. [Figure 11] 5 is a diagram illustrating the electromagnet of the switch body illustrated in FIG. 4 separated from the housing. [Figure 12] 1 is a perspective view of the installed safety switch as seen from inside the operating area, and shows the safety switch as seen obliquely from above. FIG. [Figure 13] 13 is a perspective view of the safety switch shown in FIG. 12 as viewed obliquely from below. [Figure 14] This is a view of the switch body arranged inside the operating area as viewed from outside the door. [Figure 15] 11A and 11B are diagrams for explaining the effects of the arrangement of the display unit of the safety switch according to the embodiment. [Figure 16] FIG. 4 is a diagram for explaining an example of an installation position of a display unit. [Figure 17] 13A and 13B are diagrams for explaining other examples of the installation position of the display unit. [Figure 18] FIG. 4 is a cross-sectional explanatory view of a display portion of the safety switch according to the embodiment. [Figure 19] FIG. 4 is a block diagram for explaining an electrical configuration of a switch body included in the embodiment. [Figure 20]FIG. 20 is a block diagram of a first MCU shown in FIG. 19. [Figure 21] FIG. 20 is a block diagram of the second MCU shown in FIG. 19. [Figure 22] 10 is a table for explaining a display mode of a display unit. [Figure 23] 5A to 5C are schematic diagrams for explaining the operation of the safety switch of the embodiment. [Figure 24] 11 is a flowchart illustrating a specific example of control by the first MCU. [Diagram 25] 10A and 10B are diagrams for explaining a method for determining whether or not an iron piece is in close contact with an electromagnet. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS EXAMPLES

[0014] A preferred embodiment of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is an explanatory diagram of an opening / closing door and a protective fence in which a safety switch with an electromagnetic lock mechanism of the embodiment is installed as a partition system 1. FIG. 2 is a cross-sectional view taken along line II-II in FIG. 1. In the figure, reference symbol PF indicates a protective fence, and reference symbol PD indicates an opening / closing door. FIG. 1 is an explanatory diagram of the partition system 1 as seen from outside the operating area S partitioned by the partition system 1. The partition system 1 is composed of a protective fence PF as a fixed part of the partition, a door PD constituting a movable part that can move relative to the fixed part of the partition, and a safety switch 100. The partition system 1 maintains the operating area S in a safe state by restricting the operation of the device inside the operating area S based on the safety-related output output by the safety switch 100. In this embodiment, the safety switch 100 is disposed within the operating area S. The protective fence PF constitutes a fixed part of the partition system 1 that partitions the operating area S in which the device operates. The opening in which the door PD constituting the movable part relative to the fixed part of the partition is installed is formed by a door opening frame 2. 1, a plurality of hinges 4 spaced apart vertically are provided on one side of the door PD constituting the movable part, and the door PD is attached to a vertical frame part 2a of a door opening frame 2 via the plurality of hinges 4. In other words, the door PD is a single-leaf door.

[0015] 1 and 2, the door PD is composed of a door frame 6 and a transparent board 8 surrounded by the door frame 6. The door PD has the above-mentioned hinge 4 attached to one side and a door operating unit 10 attached to the other side (FIG. 1). By operating the door operating unit 10, a door latch (not shown) that engages with and disengages from the door opening frame 2 is released, allowing the door PD to be opened.

[0016] FIG. 2 shows the state in which the door PD is closed, and the door frame 6 constituting the door PD is in contact with the door stopper 110 and positioned. In FIG. 2, the operating area S partitioned by the safety fence PF and the opening and closing door PD is an area located to the right of the safety fence PF and the door PD on the paper surface of FIG. 2. The safety switch 100 is disposed on the operating area S side in relation to the door PD in the closed state. When the door PD is closed, the safety switch 100 is disposed so as to be located on the operating area S side with respect to the door PD, so that the safety switch 100 is disposed inside the operating area S. Referring to FIG. 2, the safety switch 100 is constituted by a switch body 102 and an actuator 104. The switch body 102 is fixed to the surface of the upper horizontal frame part 2b of the door opening frame 2 on the operating area S side via a first bracket 106. The switch body 102 is provided with an electromagnet 130 having an attraction surface 130a. When the door PD is closed, the switch body 102 is installed in the door opening frame so that the suction surface 130a faces the door PD, in other words, faces the outside of the operating area S. Note that, in Fig. 2, arrows X, Y, and Z indicating three mutually orthogonal directions are illustrated, which correspond to the arrangement posture of the safety switch 100 as described later.

[0017] The switch body 102 of the safety switch 100 of the embodiment includes an electromagnet 130 (FIG. 9) and a board accommodating portion 132, as will be described later with reference to FIG. 8 etc., and the board accommodating portion 132 accommodates boards Cb(1) and Cb(2) (FIGS. 9 and 10).

[0018] On the other hand, the actuator 104 is disposed on the surface of the door frame 6 on the operating area S side, and specifically, is fixed to the upper frame portion 6a of the door frame 6 via a second bracket 108 (FIG. 2). The door opening frame 2 and the door frame 6 both have a closed rectangular cross section, which is a well-known structure, but as a modified example, they may have a U-shaped or L-shaped cross section.

[0019] The door PD is related to the opening and closing door described in Patent Document 2. On the other hand, Fig. 3 shows a box-shaped device 500 that houses a work system. In Fig. 3, three devices 500 are arranged side by side. A double-door opening and closing door 506 as an example of a door PD is attached to the box 502 of each device 500 so that an operator can manually access a device 504 installed therein. In relation to the opening and closing door 506, a safety switch 100 can be installed in the box-shaped device 500.

[0020] Hereinafter, an embodiment of the present invention will be described based on an embodiment applied to the door PD disclosed in FIG. 1 and FIG. 2 as a typical example. FIG. 4 is a substantial front view of the actuator 104 included in the safety switch 100, and is a diagram for explaining the front shape of the actuator 104. The actuator 104 is mainly composed of an iron piece 120, which is a magnetized member, and includes a plastic molded part 122, an actuator communication unit 124, and a mounting bracket 126. The iron piece 120 is circular when viewed from the front, and has an attracting surface 120a on the front side that attracts an attracting surface 130a. 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 state of being covered and hidden by the plastic molded part 122. The mounting bracket 126 is provided on the opposite side of the iron piece 120 with respect to the plastic molded part 122, and has a shape extending to the left and right on the paper surface of FIG. 4. The mounting bracket 126 has a pair of mounting holes through which screws for fastening the mounting bracket are inserted, in a portion visible from the front of the actuator 104. The pair of mounting brackets 126 are fastened to the second bracket 108, and the actuator 104 is fixed to the door PD via the second bracket 108 (FIG. 2). With the door PD closed, the actuator 104 and the switch body 102 are positioned relative to each other such that the actuator 104 is located on the surface of the door frame 6 facing the operating area S. That is, the actuator 104 is installed on the door frame 6 so that the attracted surface 120a of the iron piece 120 faces the operating area S when the door PD is closed. On the other hand, the switch body 102 is located inside the operating area S. In this embodiment, the actuator 104 is fixed to the door PD via the second bracket 108, but the mounting bracket 126 may be directly fastened to the door frame 6, and the actuator 104 may be fixed to the door PD.

[0021] An example of the arrangement when the actuator 104 is fixed to the door PD will be specifically described based on the example of the arrangement shown in FIG. 2. The actuator 104 is fixed to the upper frame portion 6a of the door frame 6 as described above. In this embodiment, the pair of mounting brackets 126 of the actuator 104 are fixed so that the mounting holes are aligned in the horizontal direction, that is, in the longitudinal direction of the upper frame portion 6a. In this installation example, reference symbol Ha in FIG. 4 indicates the height of the iron piece 120 that is circular when viewed from the front and is included in the actuator 104. In the installation example shown in FIG. 2, the actuator 104 is fixed to the door frame 6 in a state where the direction of the height Ha is aligned with the direction of the width Wdf of the upper frame 6a. The height Ha of the actuator 104 is equal to or smaller than the average width Wdf of the door frame 6 with a rectangular cross section (FIG. 2). The actuator 104 installed on the door frame 6 may have a part protruding to the inside of the door frame 6, that is, to the portion of the transparent board 8, but it is preferable that this protrusion amount be as small as possible. This can reduce the interference caused by the actuator 104 during work.

[0022] In the safety switch 100 of this embodiment, the electromagnet 130 of the switch body 102 and the iron piece 120 of the actuator 104 function as an electromagnetic locking mechanism. As described above, the electromagnetic locking mechanism of the safety switch has historically been developed following the technical idea of ​​the lock pin mechanism. The design concept of the safety switch 100 with electromagnetic locking mechanism of the embodiment will be described. In general terms, when considering the role of the safety switch, the original requirement of maintaining a safe environment in the operating area where the operating device is placed is realized by the function of detecting the opening and closing of the door, and the role required of the door lock function is to keep the device operating in the operating area. Therefore, it can be said that the door lock function is sufficient if it can keep the device operating in the operating area. In other words, the basic requirement of the door lock function of the safety switch is to prevent the opening and closing door from being inadvertently opened while the device is operating. This is because if the opening and closing door is inadvertently opened, the operation of the device in the operating area is restricted by the function of the safety switch for maintaining the operating area in a safe environment. In other words, the essential role of the door lock function required of a safety switch is to prevent the operation of the equipment in the operating area S (Figure 2) or box 502 (Figure 3) from being interrupted by the inadvertent opening of the door PD, 506.

[0023] Conventionally, the door lock function of the safety switch is designed to contribute to maintaining the operating area in a safe environment. For this reason, the electromagnetic lock mechanism also uses an electromagnet with a strong magnetic force that prevents the door from being opened even with a relatively strong operating force. However, from the viewpoint that the role of the door lock function is not to maintain a safe environment but to keep the device operating, the magnetic force of the electromagnet used in the safety switch with an electromagnetic lock mechanism may be the same as that of the conventional one, but may be weaker than that. When an operator performs an operation to open the door PD, the operating force required to open the door PD is at least required to ask the operator, "You are now operating to open the door PD. Is this as you intend?" Inadvertent opening of the door can be prevented. If a certain operating force that can confirm the operator's intention to open the door PD is required by the electromagnet, inadvertent opening of the door PD can be prevented without requiring any more operating force.

[0024] Therefore, optionally, the magnetic force of the electromagnet 130 may be made weaker than in the past. For example, in the case where the door PD has an operating part such as a doorknob, the door latch is released when an operating force for rotating the doorknob is applied to the doorknob, but the electromagnet 130 is used with a magnetic force at least stronger than the operating force for releasing the door latch. This can deter the worker from opening the door PD, and can prevent the door PD from being opened unintentionally. Also, it can be avoided that the operation of the device is unexpectedly interrupted due to the door PD being opened unintentionally.

[0025] Referring to FIG. 5, the switch body 102 includes an electromagnet 130. The electromagnet 130 is disposed so that its attracting surface 130a and side surface are exposed. The switch body 102 has a screw hole 130c as a mounting portion for fixing the switch body 102 to the door opening frame 2, which is a fixed portion of the compartment system 1. More specifically, the electromagnet 130 has a protruding portion 130b on its side surface that protrudes in a direction from the center of the attracting surface 130a toward the outside, and the screw hole 130c is provided in the protruding portion 130b. In terms of the arrangement example shown in FIG. 2, the switch body 102 is fixed to the upper horizontal frame portion 2b of the door opening frame 2 via the first bracket 106 having an L-shaped cross section (FIG. 2). In terms of the arrangement example shown in FIG. 2, the protruding portion 130b is positioned protruding from the upper portion of the electromagnet 130, and the flat top surface of the protruding portion 130b constitutes a mounting surface, and the screw hole 130c is provided in the mounting surface. This mounting surface may be formed on the side of the electromagnet 130 .

[0026] For example, in FIG. 5, arrows X, Y, and Z are shown indicating three mutually orthogonal directions. The directions indicated by the arrows X, Y, and Z correspond to the arrangement posture of the safety switch 100, and the directions indicated by the arrows X, Y, and Z are called the X-axis direction, the Y-axis direction, and the Z-axis direction, respectively. The Y-axis direction indicates the normal direction of the attraction surface 130a of the electromagnet 130. The Z-axis direction indicates the direction perpendicular to the Y-axis direction, parallel to the attraction surface 130a, and in which the protrusion 130b protrudes from the center of the attraction surface 130a. The X-axis direction indicates the direction parallel to the attraction surface 130a and perpendicular to the Z-axis. As shown in FIG. 2, the safety switch 100 of this embodiment is arranged so that the attraction surface 130a faces the door PD in the closed state, so that the normal direction of the door PD in the closed state coincides with the Y-axis direction. Moreover, the safety switch 100 of this embodiment is disposed so that the direction in which the protrusion 130b protrudes from the center of the suction surface 130a is perpendicular to the extension direction of the upper frame portion 6a of the door PD in the closed state and the extension direction of the upper horizontal frame portion 2b of the door opening frame 2. For this reason, in this embodiment, the extension direction of the upper frame portion 6a and the extension direction of the upper horizontal frame portion 2b coincide with the X-axis direction, and the direction toward the operating area S side with respect to the door PD, i.e., the depth direction of the operating area S, coincides with the Y-axis direction. In the following description, in the Y-axis direction, the direction from the door PD in the closed state toward the suction surface 130a may be called "rear" and the opposite direction may be called "forward," and in the Z-axis direction, the direction from the suction surface 130a toward the protrusion 130b may be called "upward," and the opposite direction may be called "downward."

[0027] 5 to 11 are diagrams relating to the switch body 102. FIG. 5 is a perspective view of the switch body 102 as viewed obliquely from the front and above. FIG. 6 is a view of the switch body 102 as viewed obliquely from below. FIG. 7 is a front view. FIG. 8 is a side view. As can be clearly seen from FIGS. 5, 6, and 8, the switch body 102 has a generally cylindrical shape extending in the Y-axis direction (the normal direction of the attraction surface 130a). The switch body 102 has an electromagnet 130 including an attraction surface 130a that constitutes one end surface on the front side in the Y-axis direction, and the length L (FIG. 5) from the attraction surface 130a to the other end surface is longer than the diameter of the attraction surface 130a.

[0028] The attraction surface 130a constitutes one end surface, i.e., the main portion of the front end surface, of the switch body 102. To explain this in more detail with reference to Figures 5 to 8, when a housing Hg is provided around the electromagnet 130, the attraction surface 102 protrudes beyond an end surface 132c of the housing Hg, and this attraction surface 102 constitutes the front end surface of the switch body 102. As described above, when the door PD is closed, the attraction surface 130a faces the actuator 104 of the door PD.

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

[0030] As shown in FIG. 6, the display unit 142 is provided in the switch body 102 at a position where it is easily visible from the bottom opposite to the top where the mounting hole 130c is provided. More specifically, the switch body 102 has an approximately cylindrical outer shape with the normal direction of the attraction surface 130a as an axis due to the electromagnet 130 and the housing Hg. When the switch body 102 is considered to be approximately cylindrical, the display unit 142 is provided so as to include a portion on the circumferential surface opposite to the portion where the mounting hole 130 is provided. As a result, even if the display unit 142 is disposed inside the operating area S, it is located at a position where it is easily visible from outside the operating area S. In addition, the outer surface of the display unit 142 has a shape in which a portion below the outer surface of the normal line of the outer surface is inclined downward toward the front. In this embodiment, the switch body 102 has an approximately cylindrical outer shape, but the electromagnet 130 and the housing Hg may have an approximately prismatic outer shape. In this case, the switch body 102 is provided with a display unit 142 on a side surface of the substantially rectangular column shape.

[0031] FIG. 7 is a front view of the switch body 102 as viewed from the front. The normal direction of the paper surface of FIG. 7 is parallel to the Y-axis direction. As described above, the board housing portion 132 is located behind the electromagnet 130. Therefore, when the switch body 102 is viewed from the front, most of the housing Hg having the board housing portion 132 is hidden by the electromagnet 130 as shown in FIG. 7. Therefore, the increase in the area occupied by the switch body 102 as viewed from the front due to the provision of the housing Hg is suppressed. In this embodiment, the ratio of the area occupied by the housing Hg to the area occupied by the attraction surface 130a as viewed from the front is small. Also, as described later, in this embodiment, the actuator 104 is designed so that the diameter D1 (FIGS. 4 and 23) of the iron piece 120 provided thereon is larger than the diameter D2 (FIG. 23) of the attraction surface 130a. Therefore, when the electromagnet 130 attracts the iron piece 120, most of the switch body 102 is hidden by the actuator 104 as viewed from the front.

[0032] As shown in FIG. 7, the area occupied by the housing Hg when viewed from the front is larger on the side where the screw hole 130c is provided with respect to the center of the adsorption surface 130a than on the side opposite to the side where the screw hole 130c is provided with respect to the center of the adsorption surface 130a. In other words, most of the housing Hg is located above the center of the adsorption surface 130a when viewed from the front. When the switch body 102 is fixed by the screw hole 130c, a dead space is generated between the maximum dimension part of the adsorption surface 130a in the X-axis direction and the door opening frame 2 to which the switch body 102 is attached. By utilizing the dead space as the area where the housing Hg is provided, the workability through the door opening frame 2 is not likely to decrease. Therefore, by configuring the housing Hg so that the area occupied by the housing Hg when viewed from the front is larger on the side where the screw hole 130c is provided with respect to the center of the adsorption surface 130a, the workability through the door opening frame 2 in which the switch body 102 is arranged is ensured.

[0033] FIG. 8 is a side view of the switch body 102. The switch body 102 has a board accommodating portion 132 on the opposite side to the adsorption surface 130a with respect to the electromagnet 130 (FIG. 9). Reference symbol Hg indicates a housing of the board accommodating portion 132. A connector coupling portion 144 is provided on the side of the board accommodating portion 132 opposite to the position of the adsorption surface 130a in the Y-axis direction, i.e., on the rear end surface 134 (FIGS. 8 and 9). The rear end surface 134 is also the end surface of the switch body 102 opposite to the position of the adsorption surface 130a. The connector coupling portion 144 extends in a direction away from the adsorption surface 130 along the Y-axis direction. By providing the connector coupling portion 144 on the end surface 134 of the board accommodating portion 132, it is not necessary to position the cable connected to the connector coupling portion 144 around the switch body 102. In addition, because the connector connecting portion 144 is disposed on the end surface 134 of the board accommodating portion 132, at least a portion of the cable connected to the connector connecting portion 144 near the connector connecting portion 144 is located behind the switch body 102. This reduces the risk that the visibility of the display unit 142 from the front will be reduced by the cable. In addition, by routing the cable connected to the connector connecting portion 144 behind the switch body 102 or above where the screw holes 130c are located, it is possible to route the cable so that it is not located near the opening formed by the door opening frame 2, and therefore the operability of work through the door opening frame 2 is less likely to be reduced.

[0034] Fig. 9 is a vertical cross-sectional view of the switch body 102 cut along the Z-axis. Fig. 10 is a diagram for explaining the arrangement of two boards Cb(1) and Cb(2) arranged in the board accommodating section 132. Here, Fig. 10 is a diagram in which the housing Hg has been removed to expose the inside of the board accommodating section 132. Fig. 11 is an exploded perspective view of the electromagnet 130 and the housing Hg.

[0035] 10, the protrusion 130b is preferably formed by forming a part of the yoke portion of the electromagnet 130 into a raised shape, although this is not particularly limited. In the arrangement example shown in FIG. 2, the protrusion 130b is attached so as to be located on the top, but it is also possible to attach the switch body 102 so that the attachment portion 103b is located to the side.

[0036] As can be seen from Figures 5 and 9, the protrusion 130b protruding in the Z-axis direction has two mounting holes 130c as mounting parts spaced apart in the front-to-back, i.e., Y-axis direction, and is fixed to the first bracket 106, which has an L-shaped cross section, using screws Sc that screw into the two mounting holes 130c (Figure 2).

[0037] 9 and 10, the substrate accommodating section 132 accommodates a first substrate Cb(1) and a second substrate Cb(2), which are disposed perpendicular to each other. Specifically, the first substrate Cb(1) is disposed with its plate surface aligned along the Y-axis direction, and the second substrate Cb(2) is disposed with its plate surface aligned along the Z-axis direction. The second substrate Cb(2) is disposed at the rear end of the first substrate Cb(1) in the state shown in FIG. 9, preferably so as to hang down from the first substrate Cb(1).

[0038] As described above, the switch body 102 has at least the display unit 142 (FIGS. 2, 5, and 8) that displays a display corresponding to a safety-related output output by the switch body 102. The display unit 142 is provided at a position that is visible from the opposite side of the mounting surface of the switch body 102 where the screw hole 130c serving as a mounting portion is located. In other words, the display unit 142 is provided at a position that is visible from the side where the mounting surface formed by the top surface of the protrusion 130b does not exist. When the switch body 102 is fixed to the door opening frame 2, the screw hole 130c is arranged and fixed so as to face outward from the opening formed in the door opening frame 2. Therefore, the surface opposite to the mounting surface where the screw hole 130c is provided is arranged so as to face the inside of the opening. In the example of FIG. 2, since the switch body 102 is fixed to the upper side horizontal frame portion 2b of the door opening frame 2, the direction from the opening to the outside is upward. And, since the inside of the opening of the upper side horizontal frame portion 2b is downward, the surface on which the display unit 142 is provided faces downward. In this embodiment, the switch body 102 is fixed to the upper horizontal frame portion 2b of the door opening frame 2 that forms the opening, but when the switch body 102 is fixed to the frame portion of the door opening frame 2 opposite to the side where the hinge 4 is provided (the frame portion on the right side of the paper in FIG. 1), the display unit 142 is located on the left side of the paper in FIG. 1. By providing the display unit 142 on the opposite side to the screw hole 130c in this way, the display unit 142 faces the opposite side of the frame portion of the door opening frame 2 to which the switch body 102 is attached, that is, the inside of the opening. When the operating area S is looked into from the outside of the door PD having the transparent board 8, the transparent board 8 is located inside the opening, so that the switch body is visible from the inside of the opening. Therefore, by positioning the display unit 142 inside the opening when fixed to the door opening frame 2, the visibility of the display unit 142 is improved.

[0039] The second board Cb(2) is connected to the connector coupling portion 144, and a plurality of indicator lights 150 (FIG. 9), specifically a plurality of LED elements, of different colors are mounted on the front of the lower portion of this second board Cb(2). The plurality of indicator lights (LED elements) 150 constitute the light source of the display unit 142. In the overall shape of the switch body 102, the display unit 142, which is arranged on a surface that is visible, has a function of displaying the operating state of the switch body 102 in identifiable colors, as is well known.

[0040] A modified example of the arrangement position of the mounting part will be described with reference to Fig. 18. The mounting hole 130c as the mounting part described with reference to Fig. 5 and the like forms a mounting surface on a surface in the Z-axis direction, but as can be seen from Fig. 18, a mounting surface 130c-2 may be formed on a surface in the X-axis direction. The mounting surfaces 130c-2 are preferably formed on two surfaces of the switch body 102 that face each other in the X-axis direction. Even in this modified example, the display unit 142 is provided on a surface other than the mounting surface 130c-2, that is, on the lower surface in the illustrated example, so that the display unit 142 can be seen from below.

[0041] 9, in the substrate housing portion 132, a limited illumination space Ls is formed by a first substrate Cb(1) whose plate surface extends along the front-rear, i.e., Y-axis direction, and a second substrate Cb(2) whose plate surface extends along the Z-axis direction. Then, light from the LEDs 150 mounted on the second substrate Cb(2) is emitted toward this limited illumination space Ls, thereby performing display on the display portion 142. Of course, the LEDs 150 constituting the light source may be provided on the first substrate Cb(1).

[0042] The lighting state of the display unit 142 can be seen from outside the protection door PD through the transparent board 8 (FIG. 2) of the protection door PD. This point will be described with reference to FIGS. 12 to 17. FIGS. 12 and 13 are views of the protection door PD as seen from the operating area S side. FIG. 14 is a view of the protection door PD as seen from the outside looking into the operating area S. When the switch main body 102 is disposed inside the operating area S, the visibility of the display unit 142 when the switch main body 102 is viewed from the outside through the door PD will be described with reference to FIG. 15. FIG. 15 is a schematic diagram created to explain the visibility of the display unit 142 when the display unit 142 is viewed from the outside of the door PD. In the drawings, reference symbol Ey denotes the operator's eyes.

[0043] As shown in Fig. 12, the first bracket 106 has a portion with a low dimension in the Z-axis direction. This allows a cable to be routed through the portion with a low dimension in the Z-axis direction even in an environment where a ceiling surface is located directly above the first bracket 106. Also, as shown in Fig. 13, the attracted surface 120a of the actuator 104 is configured to be one size larger than the attracting surface 130a of the electromagnet 130. For this reason, if the display unit 142 is provided near the attracting surface 120a in the axial direction of the attracting surface 120a, there is a risk that the actuator 104 will obstruct visibility of the display unit 142.

[0044] In FIG. 15, reference numeral 142-1 denotes a display unit located proximal to the adsorption surface 130a of the switch body 102. That is, the distance D-1 in the Y-axis direction between the adsorption surface 130a and the display unit 142-1 is relatively small. Reference numeral 142-2 denotes a display unit located distal to the adsorption surface 130e. The distance D-2 in the Y-axis direction between the adsorption surface 130a and the display unit 142-2 is relatively large. As can be understood from FIG. 15, the display unit 142 has better visibility when viewed from the outside through the door PD when it is located distal to the adsorption surface 130a rather than proximal to the adsorption surface 130a. In order to locate the display unit 142 distal to the adsorption surface 130a, the display unit 142 in this embodiment is located rearward of the intermediate line Imd including the intermediate line Imd having a length half the total length L of the switch body 102 in the Y-axis direction. In this way, at least a part of the display unit 142 is disposed behind the intermediate line Imd, thereby improving visibility from the front side of the switch body 102. In addition, in this embodiment, the display unit is provided at a position away from the attraction surface 130a in the Y-axis direction, and the side surface of the electromagnet 130 is exposed. With this configuration, it is possible to achieve both ease of visibility of the electromagnet 130, the position of which should be adjusted when fixing the switch body 102, and ease of visibility of the display unit 142 after the switch body 102 is fixed. Furthermore, in this embodiment, the display unit 142 is provided so that the front end of the display unit 142 is located behind the intermediate line Imd in the Y-axis direction, that is, so that the display unit 142 is separated from the attraction surface 130a by more than half the total length of the switch body 102 in the Y-axis direction. According to this, the display unit is located only behind the switch body 102, so that the degree of freedom when attaching the switch body 102 is improved.

[0045] 16 and 17 are diagrams for explaining modified arrangement positions of the display unit 142. The reference symbol "1 / 3Ln" shown in FIG. 16 indicates a first line that is 1 / 3 of the total length L of the switch body 102 from the suction surface 130a in the Y-axis direction. The display unit 142 may be arranged behind the first line 1 / 3Ln including the first line 1 / 3Ln of the switch body 102, that is, at a location away from the suction surface 130a from the first line 1 / 3Ln including the first line 1 / 3Ln. The reference symbol "2 / 3Ln" shown in FIG. 17 indicates a second line that is 2 / 3 of the total length L of the switch body 102 from the suction surface 130a in the Y-axis direction. The display unit 142 may be arranged behind the second line 1 / 3Ln including the second line 2 / 3Ln of the switch body 102. In this way, by arranging the display unit 142 so as to include a position away from the attraction surface 130a, visibility from the front side of the switch is improved. Also, by appropriately spacing the display unit 142 away from the attraction surface 130a in this way, the electromagnet 130 can be exposed. In particular, by arranging the display unit 142 behind the first line shown in FIG. 16, the side surface of the electromagnet 130 can be sufficiently exposed.

[0046] The outer surface of display unit 142 may be configured to have a flat cross-sectional shape in the Y-axis direction, but in this embodiment, it has a peripheral surface with a curved cross-sectional shape as can be seen from Fig. 18. Fig. 18 is a cross-sectional and schematic diagram of display unit 142.

[0047] As can be seen from FIG. 18, the display unit 142 extends continuously not only on the bottom surface but also on the left and right side surfaces in the state shown in FIG. 18. That is, the display unit 142 has a shape that extends continuously in the circumferential direction of the switch body 102. In this way, the display unit 142 of the switch body 102 has a shape that extends continuously from the surface opposite the mounting portion 130b in the Z-axis direction, that is, from the bottom surface in the illustrated example, to both side surfaces, and preferably extends to half of the side surface in the Z-axis direction. In the arrangement example of FIG. 2, when the switch body 102 located in the operating area S is viewed from the outside through the door PD, the display unit 142 can be viewed not only from below the switch body 102 but also from the side. In addition, even if the mounting posture of the switch body 102 in FIG. 1 is different, the display unit 130b can be easily viewed from the outside.

[0048] In order to improve visibility from the outside, as can be clearly seen from FIG. 8, the outer surface of the display unit 142 has a tapered shape that slopes downward toward the adsorption surface 130a in the Y-axis direction.

[0049] The housing Hg of the substrate accommodating portion 132 is made of a plastic molded product. A part of the housing Hg extends in the direction of the attraction surface 130a and has a shape that surrounds a part of the protruding portion 130b of the electromagnet 130. The housing Hg has a flat top surface that is substantially at the same height as the top surface of the protruding portion 130b (FIG. 5).

[0050] A control circuit that generates a drive signal for the electromagnet 130, a power supply circuit, a communication circuit with the actuator 104, and the like are mounted on the main body Cb (main body) of the first substrate Cb(1). On the other hand, an indicator light control circuit and the like are mounted on the second substrate Cb(2).

[0051] Referring to FIG. 10, in the substrate accommodating portion 132, the first substrate Cb(1) whose plate surface extends along the Y-axis direction has a pair of elongated substrate extensions Cb(1ex) extending in the Y-axis direction from a main body Cb (main body) located in the substrate accommodating portion 132 and mounting a control circuit and the like to the vicinity of the adsorption surface 130a. The pair of substrate extensions Cb(1ex) are located on both sides of the protrusion 130b in the X-axis direction. By positioning the pair of substrate extensions Cb(1ex) on both sides of the protrusion 130b, it is possible to prevent the presence of the substrate extensions Cb(1ex) from increasing the height dimension of the switch body 102 in the Z-axis direction. In addition, the substrate extensions Cb(1ex) are located at a position where a part of them overlaps with the electromagnet 130 when viewed in the Z-axis direction. Therefore, it is possible to reduce the increase in the dimension of the switch body 102 in the X-axis direction due to the presence of the substrate extensions Cb(1ex).

[0052] In the pair of board extensions Cb(1ex), a sensor side coil (antenna coil) 152 is mounted on the tip of one of the board extensions Cb(1ex) (FIG. 10). The sensor side coil 152 constitutes a detection unit that detects that the actuator 104 is within a predetermined range relative to the switch body 102. By mounting the sensor side coil 152 on the tip of one of the board extensions Cb(1ex), the sensor side coil 152 can be positioned close to the adsorption surface 130a in the Y-axis direction. As a result, the detection ability of the sensor side coil 152 can be improved. As is well known, the sensor side coil 152 is disposed in correspondence with the actuator communication unit 124 of the actuator 104 described above. At this time, in order for the sensor side coil 152 to detect the actuator communication unit 124, the sensor side coil 152 is covered with a housing Hg made of plastic rather than metal. For this reason, in the switch body, a part of the housing Hg exists on the surface facing the actuator 102 in addition to the adsorption surface 130a. In this embodiment, as described above, by disposing a part of the housing Hg in a dead space, workability through the door opening frame 2 in which the switch main body 102 is disposed is maintained.

[0053] For example, in the process of closing the door PD, the iron piece 120 of the actuator 104 approaches the attracting surface 130a of the switch body 102 in conjunction with the closing operation of the door PD, as shown in FIG. 23, and then the iron piece 120 overlaps with the attracting surface 130a of the switch body 102. The iron piece 120 (attached surface 120a) is designed to have a diameter D1 (FIG. 4) larger than the diameter D2 of the attracting surface 130a. Based on the state in which the iron piece 120 overlaps with the switch body 102 in the normal state, that is, the normal state in which the center O1 of the iron piece 120 and the center O2 of the attracting surface 130a are aligned, the diameter D1 of the iron piece 120 is set relative to the diameter D2 of the attracting surface 130a so that the outer edge of the attracting surface 130a is located within the attracted surface 120a of the iron piece 120. As a result, even if the switch body 102 and / or the actuator 104 undergo a permissible relative displacement, the switch body 102 can fix the actuator 104 with a predetermined adsorptive force.

[0054] When the door PD is closed, that is, when the sensor side coil 152 detects the actuator communication unit, a safety-related output is output to a control device (e.g., a PLC) that controls devices installed in the operating area S (FIG. 2). An RFID detection circuit (not shown) associated with the sensor side coil 152 is mounted on the board extension Cb(1ex) of the first board Cb(1), and the electromagnet 130 is controlled based on a signal from the sensor side coil (antenna coil) 152.

[0055] 19 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.

[0056] The first MCU 202 is connected to a transmission circuit 206. The transmission circuit 206 is connected to a sensor side coil (antenna coil) 152. The sensor side coil 152 is connected to a reception circuit 208. The reception circuit 208 is connected to both the first MCU 202 and the second MCU 204. The sensor side coil 152 is controlled to exchange wireless signals with a coil included in the actuator communication unit 124. The first MCU 202 drives the sensor side coil 152 via the transmission circuit 206 to supply a wireless signal from the sensor side coil 152 to the actuator communication unit 124. The actuator communication unit 124 has at least a coil and a circuit, and is arranged so that the coil is located in a portion covered by the plastic molded product 122 as shown in FIG. 4. The first MCU 202 and the second MCU 204 receive a wireless signal from the actuator communication unit 124 via the sensor side coil 152 and the reception circuit 208. The RFID 152 has the sensor side coil 152 and a response circuit. The actuator communication unit 124 may be a wireless tag (RF-ID tag). The response circuit operates using as a power source an induced current generated in the sensor side coil 152. The response circuit demodulates the wireless signal received by the sensor side coil 152 to acquire information, and further transmits a wireless signal (response signal) via the sensor side coil 152.

[0057] 20 and 21, the measurement unit 210a of the first MCU 202 and the measurement unit 210b of the second MCU 204 each measure the strength of a wireless signal received from the actuator communication unit 124 via the sensor side coil 152 and the receiving circuit 208, and estimate a distance d (FIG. 23) between the switch body 102 and the actuator 104 based on the strength of the wireless signal. The safety determination circuit 214a of the first MCU 202 and the safety determination circuit 214b of the second MCU 204 each determine whether the estimated distance d is equal to or smaller than a threshold, that is, whether the actuator 104 is within a predetermined range with respect to the switch body 102. In other words, a detection unit that detects that the actuator 104 is within a predetermined range with respect to the switch body 102 is realized by at least the sensor side coil 152, the receiving circuit 208, and the first MCU 202 or the second MCU 204. Note that the strength of the wireless signal may be used directly instead of the distance d to detect the position of the actuator 104. The demodulator 212a of the first MCU 202 and the demodulator 212b of the second MCU 204 each demodulate information carried by a wireless signal from the actuator communication unit 124 received via the sensor side coil 152 and the receiving circuit 208, and identify the actuator 104 based on this information. This information may include unique identification information.

[0058] The safety determination circuit 214a of the first MCU 202 determines whether or not two conditions are satisfied, that the estimated distance d is equal to or less than a threshold and that the actuator 104 is identified as a predetermined actuator, based on the measurement by the measurement unit 210a and the identification by the demodulation unit 212a, and transmits the determination result to the second MCU 204. More specifically, there are two types of determination results: that both conditions are satisfied, or that at least one of the conditions is not satisfied. Similarly, the safety determination circuit 214b of the second MCU 204 determines whether or not two conditions are satisfied, that the estimated distance d is equal to or less than a threshold and that the actuator 104 is identified as a predetermined actuator, based on the measurement by the measurement unit 210b and the identification by the demodulation unit 212b, and transmits the determination result to the first MCU 202. When the safety determination circuit 214a of the first MCU 202 and the determination result of the second MCU match, the safety determination circuit 214a outputs a safety-related output that determines that the actuator 104 identified as the predetermined actuator is in a predetermined range with respect to the switch body 102, that is, the door PD is in a closed state. Similarly, when the safety determination circuit 214b of the second MCU 204 and the determination result of the first MCU match, the safety determination circuit 214b of the second MCU 204 determines that the actuator 104 identified as the predetermined actuator is in a predetermined range with respect to the switch body 102, that is, the door PD is in a closed state. Note that in this embodiment, as described later, when a condition related to a signal input via the input circuit 220 is also satisfied, the first MCU 202 and the second MCU 204 output a safety-related output via an OSSD (Output Signal Switching Device), but the safety-related output may be output based on a wireless signal received via the receiving circuit 208 and the mutual determination results of the first MCU 202 and the second MCU 204.Furthermore, in this embodiment, the distance d between the switch body 102 and the actuator 104 is estimated and the actuator 104 is identified based on the wireless signal detected by the sensor side coil 152, but a configuration may also be adopted in which only the distance d is estimated and the safety judgment circuits 214a, 214b do not make a judgment regarding the identification of the actuator 104, but rather output the judgment result of whether the distance d is below a threshold value to the other safety judgment circuit.

[0059] 19 , the input circuit 220 has a first safety input unit 222, a second safety input unit 224, and a lock input unit 226. The first safety input unit 222 and the second safety input unit 224 are connected to other devices capable of outputting a safety-related output. 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 are connected such that one of the terminals for outputting a safety-related output of the other device is connected to the first safety input unit 222, and another of the terminals for outputting a safety-related output of the other device is connected to the second safety input unit 224.

[0060] The lock input unit 226 is connected to an external control device such as a safety PLC or a safety control device, and receives a lock signal for controlling a lock mechanism output from the external control device, and outputs an input signal to the second MCU 204. The second MCU 204 determines whether the signal input via the lock input unit 226 is an ON signal. The second MCU 204 can drive the electromagnet 130 based on the lock signal input via the lock input unit 226 to attract the electromagnet 130 to the iron piece 120 of the actuator 104. That is, the door PD is locked by a magnetic force in response to the signal input via the lock input unit 226. The second MCU 204 may drive the electromagnet 130 when the signal input via the lock input unit 226 is an ON signal, or may drive the electromagnet when it is determined that the signal input via the lock input unit 226 is an ON signal and other conditions are satisfied. For example, the above-mentioned determination by the safety determination circuits 214a, 214b may be set as a condition for driving the electromagnet 130. In this case, the electromagnet 130 is driven when it is determined that a predetermined actuator 104 is in a predetermined range with respect to the switch body 102, so that the door PD is more reliably maintained in a closed state by the lock signal output by the external control device.

[0061] The control circuit 200 includes a first OSSD 230a and a second OSSD 230b as the switching device 230. The first MCU 202 and the second MCU 204 each generate a safety signal, the first MCU 202 outputs a safety-related output as a safety signal via the first OSSD 230a, and the second MCU 204 outputs a safety-related output as a safety signal via the second OSSD 230b. Note that the external device to which the safety-related output is output via the first OSSD 230a and the second OSSD 230b and the external control device that outputs the lock signal input via the lock input unit 226 may be the same device or different devices, but both of them constitute the partition system 1.

[0062] The first OSSD 230a and the second OSSD 230b are, for example, configured with a PNP transistor. When the PNP transistor is turned ON, the output terminal is connected to the +side power supply, and an ON signal is output. On the other hand, when the PNP transistor is turned OFF, the output terminal is grounded via a pull-down resistor, and an OFF signal is output.

[0063] The first OSSD 230a and the second OSSD 230b may be connected to an OSSD monitoring circuit 232, respectively. The OSSD monitoring circuit 232 is connected to the first MCU 202 and the second MCU 204. The first MCU 202 monitors whether the second OSSD 230b is operating normally through the OSSD monitoring circuit 232. The second MCU 204 monitors whether the first OSSD 230a is operating normally through the OSSD monitoring circuit 232. For example, the first OSSD 230a and the second OSSD 230b each periodically transition their output signal to OFF for a very short time when outputting an ON signal. If the OSSD monitoring circuit 232 can detect an OFF state for a very short time during the output period of the ON signal, it determines that the OSSD is normal, and if it cannot detect an OFF state for a very short time, it determines that the OSSD is not normal.

[0064] In addition, a case where the OSSD monitoring circuit 232 cannot detect a very short OFF and an ON signal continues is caused, for example, by a short circuit between the output terminal and the positive power supply. In this case, the safety determination circuits 214a, 214b output control signals to the first OSSD 230a and the second OSSD 230b to output an OFF signal. As a result, the first OSSD 230a and the second OSSD 230b that operate normally output an OFF signal. In addition, the transition of the safety-related output to OFF for monitoring by the OSSD monitoring circuit 232 is set to a very short time so that the external device to which the safety-related output is output does not react to the OFF.

[0065] The power supply circuit 240 is a DC-DC converter that receives DC +24V and 0V from the outside and generates DC voltages such as DC +10V, +5V, and +3.3V. The power supply circuit 240 supplies power to all circuits that require power, such as the control circuit 200, the sensor side coil 152, and the display unit 142. However, if the supply voltage from the external power source or the voltage output from the power supply circuit 240 is not within a predetermined range, the control circuit 200 and the like may not operate normally. Therefore, the power supply monitoring circuit 242 judges whether the supply voltage from the external power source is within a predetermined range, and judges whether the voltage output from the power supply circuit 240 is within a predetermined range, and outputs the judgment results to the first OSSD 230a and the second OSSD 230b. When the judgment results indicating that the power supply circuit 240 is not operating normally are input, the first OSSD 230a and the second OSSD 230b each turn off the safety-related output without depending on the control signal output from the control circuit 200. When the first OSSD 230a and the second OSSD 230b receive a determination result indicating that the power supply circuit 240 is operating normally, they each output a safety-related output depending on the control signal output from the control circuit 200.

[0066] The control circuit 200 includes a display control unit 252 that controls the display unit 142, and the display control unit 252 included in the second MCU 204 generates status information according to at least the safety-related output via the second OSSD 230b, and supplies a display status signal corresponding to the status information to the display control unit 252. Since the safety-related output via the second OSSD 230b is based on at least a detection result of whether or not the actuator 104 is in a predetermined range with respect to the switch main body 102, it can be said that the display control unit 252 generates status information based on a detection result of whether or not the actuator 104 is in a predetermined range with respect to the switch main body 102. 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.

[0067] The column "indicator lamp" in FIG. 22 indicates the light emission pattern of the display unit 142 controlled based on the display status signal supplied to the display control unit 252, i.e., the status information generated by the display control unit 252. The column "status" is subdivided into "OSSD", "safety input", "lock control input", and "actuator". The column "OSSD" indicates whether the safety-related output outputted to the external control device via the first OSSD 230a and the second OSSD 230b as the switching device 230 is ON or OFF. The columns "safety input", "lock control input", and "actuator" indicate the judgment items used when determining whether the safety-related output outputted via the switching device 230 is ON or OFF. The column "safety input" indicates whether the safety-related output inputted via the first safety input unit 222 and the second safety input unit 224 is ON or OFF. The column "lock control input" indicates whether the lock signal inputted from the external control device via the lock input unit 226 is ON or OFF. The column “Actuator” indicates whether an actuator 104 identified as a specified actuator based on a radio signal received via the sensor side coil 152 and the receiving circuit 208 has been detected to be within a specified range of the switch body 102.

[0068] As shown in FIG. 22, in this embodiment, the safety-related output outputted through the switching device 230 is ON when the safety-related output inputted through the first safety input unit 222 and the second safety input unit 224 is ON, the lock signal inputted through the lock input unit 226 is ON, and the actuator 104 is detected. At this time, the light-emitting pattern of the display unit 142 is green. When the actuator 104 is not detected, the safety-related output outputted through the switching device 230 is OFF regardless of the safety-related output or the lock signal inputted through the first safety input unit 222 and the second safety input unit 224, and the light-emitting pattern of the display unit 142 is red. The safety switch 100 of this embodiment detects whether the actuator 104 is within a predetermined range with respect to the switch body 102 in order to maintain the operating area S in a safe environment. When the actuator 104 is not detected, the door PD is not in a closed state and the operating area S is not maintained as a safe environment, so the safety-related output outputted through the switching device 230 is OFF regardless of the input state of other signals.

[0069] The safety switch 100 of this embodiment determines whether to turn on or off the safety-related output outputted through the switching device 230 by referring to the input states of various signals in addition to the detection of the actuator 104. At this time, it is difficult for an operator to grasp the state of the safety-related output and the lock signal inputted through the first safety input unit 222 and the second safety input unit 224, compared to the detection of the actuator 104. More specifically, whether the actuator 104 is detected or not has a certain correlation with whether the door PD is in a closed state or not. Therefore, when the actuator 104 is not detected and the safety-related output outputted from the switch main body 102 through the switching device 230 is OFF, it is easy for an operator to identify the cause. In contrast, with regard to the safety-related output and the lock signal inputted through the first safety input unit 222 and the second safety input unit 224, although an operator can check from the outside whether the cables corresponding to these are connected or not, it is difficult for an operator to grasp from the outside what the signals supplied through the cables are. For this reason, in this embodiment, when the safety-related output output via the switching device 230 is OFF due to the input states of various signals, the illumination pattern of the display unit 142 is changed according to the input states of various signals, making it easier for the operator to identify the reason why the safety-related output output from the switch main body 102 via the switching device 230 is OFF.

[0070] In this embodiment, since another device capable of outputting a safety-related output is connected to the first safety input unit 222 and the second safety input unit 224, the safety-related output output by the switch main body 102 and the light-emitting pattern of the display unit 142 change depending on the "safety input" column in Fig. 22. However, if the other device is not connected, the safety-related output output by the switch main body 102 and the light-emitting pattern of the display unit 142 may be determined depending on the "lock control input" column and the "actuator" column. In this case, when the "lock control input" column is "ON" and the "actuator" column is "Detected", the safety-related output output by the switch main body 102 is ON and the light-emitting pattern of the display unit 142 is lit in green. In this case, there is no case in which the light-emitting pattern of the display unit 142 is "orange" or "flashing orange" as shown in Fig. 22.

[0071] Concerning the control of the display unit 142, the control executed by the first MCU 202 and the second MCU 204 will be described with reference to the flowchart shown in Fig. 24. In step S1, the sensor side coil 152 (Fig. 19) of the switch body 102 and the actuator communication unit 124 (Fig. 4) of the actuator 104 measure the distance d (Fig. 23) between the iron piece 120 and the electromagnet 130. In the next step S2, it is determined whether the measured distance d is within a predetermined range, and if Yes (within the predetermined distance range), an ID is obtained from the actuator communication unit 124 (S3).

[0072] In the next step S4, if it is confirmed that the acquired ID matches the recorded ID, the process proceeds to the next step S5, where it is determined whether the electromagnet 140 of the switch body 102 and the iron piece 120 of the actuator 104 are in close contact with each other.

[0073] 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. 19), and measure the distance d (FIG. 23) between the actuator 104 and the electromagnet 130 as described above. If the measured distance d is within a predetermined range, an ID is acquired from the actuator communication unit 124, and it is confirmed whether the acquired ID matches the recorded ID. After confirming that the ID matches the recorded ID, it is determined whether the electromagnet 130 and the iron piece 120 are in close contact with each other, and at this time, the first MCU 202 and the second MCU 204 determine whether the distance d2 between the attracting surface 130a and the attracted surface 120a is equal to or less than a threshold value by a means different from that for determining whether the distance d is within the predetermined range.

[0074] With reference to FIG. 25, the determination of whether the distance d2 is equal to or smaller than the threshold value will be specifically described. The second MCU 204 supplies an inspection current to the electromagnet 130 and monitors the current flowing through the electromagnet 130 at this time. (I) in FIG. 25 shows a rectangular wave of the inspection current. The value of this inspection 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 form the locked state of the safety switch 100. If a current with the same value as the locking current is adopted for inspection, the electromagnet 130 will attract the iron piece 120 with an attractive force sufficient to maintain the door PD in a closed state even if the lock signal is not ON, which will cause an obstacle to the operation of opening the door PD and reduce the operability of the worker. For this reason, the value of the inspection current can be set 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, thereby maintaining the operability of the worker.

[0075] Fig. 25(II) shows the monitoring current flowing through the electromagnet 130 in response to the inspection current of the rectangular wave in Fig. 25(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. 25(III) shows the monitoring current flowing through the electromagnet 130 in response to the inspection current of the rectangular wave in Fig. 25(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 25, 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.

[0076] When the time from when the supply of the inspection current is started until the value of the monitoring current reaches a certain value differs, the value of the current flowing through the electromagnet 130 at the timing when a certain time has elapsed from when the supply of the inspection current is started differs. For comparison between (II) and (III) of FIG. 25, the timing when a certain time has elapsed from when the supply of the inspection current to the electromagnet 130 is started is illustrated as the inspection confirmation timing. The value of the monitoring current flowing through the electromagnet 130 at the inspection confirmation timing in a state where the distance d2 between the attracting surface 130a and the attracted surface 120a is greater than the threshold is the first monitoring current value I1 shown in (II) of FIG. Also, the value of the monitoring current flowing through the electromagnet 130 at the inspection confirmation timing in a state where the distance d2 between the attracting surface 130a and the attracted surface 120a is equal to or less than the threshold is the second monitoring current value I2 shown in (III) of FIG. Comparing the first monitoring current value I1 and the second monitoring current value I2, the first monitoring current value I1 is larger. That is, a monitoring current that takes a short time from the time the inspection current is supplied until it reaches a certain value ((II) in FIG. 25), in other words, a monitoring current with high responsiveness, has a larger current value at the inspection confirmation timing, compared with a monitoring current with low responsiveness ((III) in FIG. 25). Therefore, by comparing the values ​​of the monitoring current at the inspection confirmation timing, it is possible to determine whether the responsiveness of the monitoring current flowing through the electromagnet 130 is high or low, the magnitude of inductance associated with the high or low responsiveness, and the length of the distance d2 between the attracting surface 130a and the attracted surface 120a associated with the magnitude of inductance. More specifically, a threshold current value is set at least between the first monitoring current value I1 and the second monitoring current value I2 so that the magnitude relationship between the distance d2 and the threshold value can be determined, and whether the distance d2 is greater than or equal to the threshold value is determined depending on whether the current value of the monitoring current at the inspection confirmation timing is greater than or equal to the threshold value. That is, it is determined whether or not the attracting surface 130a of the electromagnet 130 and the attracted surface 120a of the iron piece 120 are in close contact with each other.

[0077] In step S5, when it is determined that the electromagnet 140 and the iron piece 120 are in close contact with each other, the process proceeds to step S6 to check whether the lock input is an ON signal or not, and if it is YES, that is, an ON signal, the process proceeds to step S7 to drive the electromagnet 140.

[0078] Step S8 is a step executed when the switch main body 102 of this embodiment is connected to another device capable of outputting a safety-related output. More specifically, this step is executed when a terminal to which the safety-related output of the other device is output is connected to the first safety input unit 222 and the second safety input unit 224. In this embodiment, as described above, the safety-related output output from the other device is input to the first safety input unit 222 and the second safety input unit 224, so in step S8, it is determined whether or not the safety-related output output from the other device is an ON signal. If YES, the safety-related output becomes an ON signal, and the display unit 142 is lit in green (S10). If NO in step S9, the safety-related output becomes an OFF signal, and the display unit 142 is lit in orange (S11). As described above, in this embodiment, the display unit 142 lights up in red when the actuator 104 is not normally detected, and lights up in green when the switch main body 102 sets the safety-related output to an ON signal. That is, when one safety switch 100 is used, the state of the safety switch 100 can be understood by the two colors, red and green. In contrast, when one safety switch 100 is used in combination with another device capable of outputting a safety-related output, the number of luminous colors of the display unit 142 increases, and the increased luminous color is assigned to a color indicating that the safety-related output from the safety switch 100 is an OFF signal because the safety-related output of the other device is not an ON signal. This makes it easier to identify the reason why the safety-related output from the safety switch 100 is an OFF signal when one safety switch 100 is used in combination with another device capable of outputting a safety-related output.

[0079] If the result is NO in step S6 described above, the process proceeds to step S12. The determination in step S12 is the same as that in step S8. If the result is YES in step S12, the safety output is turned OFF in step S13, and the display unit 142 flashes in green. If the result is NO in step S12, the safety output is turned OFF, and the display unit 142 flashes in orange (S14). In this way, by making the light emission pattern of the display unit 142 flash when the lock input is OFF, the driving state of the electromagnet 130 can be grasped in distinction from the state of the safety-related output of other devices. The control of the first MCU 202 has been described above, and the output to the display unit 142 is performed after the determination result of the first MCU 202 and the determination result of the second MCU 204 are collated. [Explanation of symbols]

[0080] PF Protective fence (fixed part of the compartment) PD Opening and closing door (moving part) S The operating area in which the device operates 100 Example of safety switch with electromagnetic lock mechanism 102 Switch body 104 Actuator 130 Electromagnet 130a Adsorption surface 142 Display unit of switch body

Claims

1. A safety switch in which an actuator having a magnetized member on which an attracting surface is formed is installed so as to be movable relative to a switch body, a detection unit that detects whether the actuator is within a predetermined range relative to the switch body; an electromagnet having an attracting surface formed on its front side corresponding to the attracting surface of the actuator; a lock input unit that receives a lock instruction to lock the relative movement of the actuator; a drive control unit that drives the electromagnet so that an attracting surface of the electromagnet and an attracted surface of the actuator are attracted to each other based on the lock instruction received by the lock input unit; a safety control unit that generates a safety signal based on the detection by the detection unit; a display control unit that generates status information based on a detection result by the detection unit; a display unit that is disposed laterally behind the electromagnet and that displays the status information generated by the display control unit.

2. A safety switch comprising: an actuator having a magnetized member on which an attracting surface is formed; and a switch body having an attracting surface corresponding to the attracting 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 supply a locking current to the electromagnet so that the attracting surface and the attracted surface are attracted to each other, and that generate state information based on the detection result by the detection unit; a housing provided on the rear side of the electromagnet and accommodating the one or more control boards; Equipped with The housing is provided with a display unit that displays the status information and is arranged laterally behind the electromagnet.

3. 3. The safety switch according to claim 1, wherein the display unit is disposed at a position spaced apart from the attraction surface in a direction normal to the attraction surface.

4. a housing connected to the electromagnet at a rear side thereof; an attracting surface of the electromagnet and at least a part of a side surface of the electromagnet are exposed; The safety switch according to claim 1 , wherein the electromagnet and the housing have a generally cylindrical outer shape.

5. a housing connected to the electromagnet at a rear side thereof; an attracting surface of the electromagnet and at least a part of a side surface of the electromagnet are exposed; The safety switch according to claim 1, wherein the housing and the electromagnet form a substantially rectangular pillar-shaped outer shape.

6. the detection unit has an antenna coil that exchanges wireless signals with an actuator coil provided in the actuator, 6. The safety switch according to claim 2, wherein the antenna coil is accommodated in the housing on the side of the electromagnet.

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

8. The safety switch according to claim 1 , wherein the display control unit generates the state information based on the detection result and a drive state of the electromagnet.

9. a mounting portion for fixing the switch body to an installation location; The safety switch according to claim 1 or 2, wherein at least a portion of the display portion is provided on a side opposite to the attachment portion in a circumference having an axis in a direction normal to the attraction surface.

10. the safety switch has an overall shape in which the length in the normal direction of the attraction surface is greater than the diameter of the attraction surface, 3. The safety switch according to claim 1, wherein the attraction surface constitutes one end surface of the safety switch in the normal direction.

11. 11. The safety switch according to claim 10, wherein the display unit is disposed at a position spaced apart from the attraction surface in a normal direction of the attraction surface by at least one-third of the total length of the switch body.

12. The safety switch according to claim 10, wherein the display unit is disposed at a position spaced apart from the attraction surface in a normal direction of the attraction surface by at least half of the overall length of the switch body.

13. The safety switch according to claim 1 or 2, wherein the outer surface of the display portion has a curved cross-sectional shape.

14. The safety switch according to claim 1 or 2, wherein the outer surface of the display portion has a shape that tapers toward the adsorption surface.

15. 15. The safety switch of claim 14, wherein the outer surface of the indicia has a curved cross-sectional shape.

16. A safety switch comprising: a switch body disposed in a fixed portion of a partition system that defines an operating area in which a device operates; and an actuator disposed in a movable portion that is movable relative to the fixed portion of the partition system, The switch body is a detection unit that detects whether the actuator is within a predetermined range relative to the switch body; an electromagnet having an attracting surface that attracts a magnetized member provided on the actuator; a display unit that displays a detection result by the detection unit and is provided at a position hidden by the actuator when viewed in the normal direction of the attraction surface, A safety switch characterized in that the display unit is arranged at a position, in a normal direction of the attraction surface, that is at least half the total length of the switch body in the normal direction from the attraction surface.

Images