Safety switch

Abstract

To form the state that an attracted surface and an attracting surface closely overlap with each other by establishing close contact between the attracted surface and the attracting surface at a high level when an open / closed door is closed.SOLUTION: An electromagnetic lock type safety switch (100) includes an actuator (104) including a magnetized member (120) on which an attracted surface is formed corresponding to an attracting surface formed on an electromagnet (130) of a switch body (102), an actuator mounting part (126) for mounting the actuator on a movable portion (the open / closed door), and a moving mechanism for supporting the magnetized member (120) movably with respect to the actuator mounting part (126). By the moving mechanism, the position of the attracted surface of the magnetized member (120) relative to the actuator mounting part (126) is offset to the attracting surface of the switch body (102) when the actuator (104) is in a predetermined range from the switch body (102) than when the actuator is not in the predetermined range from the switch body.SELECTED DRAWING: Figure 19

Description

Technical Field

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

Background Art

[0002] In an environment where an apparatus operates, if a human body can freely contact the operating apparatus, the apparatus may cause harm to the human body. In an environment where an apparatus operates, in order to prevent the operating apparatus from harming the human body, in other words, to realize a safe state, an operation area where the apparatus operates is partitioned by protective fences or partition panels. One method for achieving a safe state by partitioning the operation area is to prevent the human body from entering the operation area by partitioning the operation area with a fixed part such as a protective fence, that is, a method of isolating the operation area from the area where the human body is present. Another method is to partition the operation area and construct a partition system capable of restricting the operation of the apparatus. In the partition system, while the operation area is partitioned by a fixed part such as a protective fence, an opening is provided in a part of the partition and a movable part for opening and closing the opening is installed to allow an operator to access the operation area, that is, the partition is formed to allow an operator to enter the operation area. In this partition system, a control system is constructed so as to monitor the movable part and control the apparatus operating in the operation area according to the monitoring result so as not to cause harm to the human body. In such a partition system, a safety switch for monitoring opening and closing of the movable part is installed in an area of the opening where the movable part is installed.

[0003] The safety switch is composed of a switch body disposed on a fixed part of the partition and an actuator disposed on an opening / closing door constituting the movable part of the partition. As a function for maintaining the operation area in a safe state, the safety switch detects and outputs that the door, which is the movable part, is opened. In the entire partition system, the apparatus in the operation area is controlled so as not to cause harm to the human body according to the output from the safety switch. For example, by adopting a system configuration that stops the apparatus in the operation area according to the output from the safety switch, safety measures for the environment where the apparatus operates can be implemented.

[0004] As a type of safety switch, a safety switch with a locking pin mechanism is disclosed in Patent Document 1. The safety switch with a locking pin mechanism has an actuator bolt installed on the compartment fixing part and a switch body installed on the door, with a locking pin provided on the switch body. The actuator bolt and the switch body are positioned relative to each other, facing each other when the door is closed. In the locking pin mechanism, a locked state is formed when the locking pin mechanically engages with the actuator bolt, causing the actuator bolt and the locking pin to become physically integrated. The safety switch with a locking pin mechanism is provided with a detection mechanism to detect when the safety switch with a locking pin mechanism is in the locked state, and outputs an output indicating that it is not in the locked state when it is not. By closing the door and locking the locking pin mechanism, the closed door is fixed in an integrated state with the compartment fixing part. Conversely, by disengaging the locking pin from the actuator bolt, an unlocked state is formed, and the door can be opened.

[0005] Patent Document 2 discloses another type of safety switch, a safety switch with an electromagnetic locking mechanism. Specifically, the safety switch with an electromagnetic locking mechanism comprises 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 the fixed part of the partition, such as a protective fence. The door lock state is formed when the electromagnet is driven and attracts the actuator magnetized member. The safety switch is equipped with a display unit. The display unit shows the safety status of the operating area.

[0006] Patent Document 2 also discloses a module comprising a monitoring sensor and a monitoring actuator for monitoring the opening and closing of a door. The monitoring actuator is installed on the opening and closing door, while the monitoring sensor is installed on a fixed 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 that includes a first state signal indicating "door is open" or a second state signal indicating "door is closed".

[0007] In a safety switch equipped with a door lock mechanism, the function for safely maintaining the operating area is to monitor the opening and closing of the door and output the monitoring results to a control device that can control the devices operating in the operating area. The door lock function contributes to maintaining the closed state of the door.

[0008] A safety switch equipped with an electromagnetic locking mechanism as a door locking mechanism requires that the electromagnet's suction surface and the actuator's surface be in close contact in order to exert sufficient suction force to maintain the closed position of the door. In other words, if there is a gap between the suction surface and the surface behaved, the designed suction force cannot be exerted. Therefore, even when the door is closed, if the suction surface and the surface behaved are not in close contact, for example, if the door's range of motion is restricted due to a door stopper or misalignment of the door after the safety switch is installed, and the surface behaved of the actuator placed on the door does not come into contact with the suction surface, the designed suction force may not be exerted.

[0009] Regarding a configuration for bringing an adsorption surface and a surface to be adsorbed into close contact, Patent Document 3 discloses a configuration in which an iron piece (corresponding element) is fixed to a base element via a connecting element, and a socket that can be expanded and contracted is provided between the connecting element and the base element. As the door closes, the iron piece collides with the electromagnet. At this time, the socket deforms and the iron piece is pushed in, so the impact of the iron piece colliding with the electromagnet is absorbed by the socket. With such a configuration, in order to bring the adsorption surface and the surface to be adsorbed into close contact, it becomes possible to position the safety switch such that the electromagnet and the actuator collide when the door is closed. In other words, Patent Document 3 discloses a configuration for bringing an adsorption surface and a surface to be adsorbed into close contact in which the surface to be adsorbed moves in a direction in which it is pushed in. [Prior art documents] [Patent Documents]

[0010] [Patent Document 1] Japanese Patent Publication No. 2019-183541 [Patent Document 2] Special Publication No. 2016-510382 [Patent Document 3] Special Publication No. 2005-528738 [Overview of the project] [Problems that the invention aims to solve]

[0011] As mentioned above, even a small gap, perhaps the size of a piece of paper, between the suction surface and the surface to be suctioned when the door is closed can prevent the electromagnetic force from being exerted as designed. For this reason, safety switches are used, for example, to stop the rotation of the closing door, to ensure that the suction surface and the surface to be suctioned make secure contact when the door is closed. Therefore, although some of the impact is absorbed by the deformable elements, the safety switch is subjected to the impact of the door rotating towards the closed position, requiring a robust and relatively large housing that can withstand this impact.

[0012] The object of the present invention is to provide a compact safety switch with an electromagnetic locking mechanism that can establish a high level of contact between the surface to be attracted and the attracting surface when the opening and closing door is closed, thereby forming a state in which the surface to be attracted and the attracting surface overlap without any gaps. [Means for solving the problem]

[0013] In response to the above technical problems, the present invention provides: A safety switch comprising a switch body positioned in a fixed partition portion of a partitioning system that demarcates an operating area in which the device operates, and an actuator installed in a movable portion that is movable relative to the fixed partition portion, wherein the actuator detects that it is within a predetermined range relative to the switch body, The actuator, A magnetized member having an adsorption surface that corresponds to the adsorption surface formed on the electromagnet provided on the switch body, An actuator mounting portion for attaching the actuator to the movable part, The device includes a moving mechanism that movably supports the magnetized member with respect to the actuator mounting portion such that the relative position of the surface of the magnetized member to be attracted with respect to the actuator mounting portion is offset toward the surface of the switch body when the actuator is within a predetermined range with respect to the switch body than when the actuator is not within a predetermined range with respect to the switch body. The actuator is equipped with a permanent magnet, Due to the attractive force of the permanent magnet, the magnetized member moves to a position where its relative position to the surface to be attracted is offset toward the surface to be attracted. The electromagnet attracts the magnetized member after the attracting surface and the surface to be attracted come into contact. , provides a safety switch.

[0014] According to the present invention, during the process of closing the opening and closing door, the actuator is offset towards the switch body. Therefore, if the opening and closing door can move to a position where the surface to be attracted can come into contact with the suction surface due to the offset of the actuator, the movement mechanism will create a state of close contact between the suction surface and the surface to be attracted. This makes it possible to establish a state of close contact between the surface to be attracted and the suction surface at a high level.

[0015] The functions and effects of the present invention and other objects will become apparent from the following detailed description of preferred embodiments of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] [Figure 1] It is a front view of a protective wall and an opening / closing door provided with the safety switch of the embodiment. [Figure 2] It is a cross-sectional view cut along the line II-II in Fig. 1. [Figure 3] It is a diagram for explaining a box-type device to which the safety switch of the present invention can be applied. [Figure 4] It is a perspective view of an actuator included in the safety switch of the embodiment. [Figure 5] It is a perspective view of a switch body included in the safety switch of the embodiment, viewed from diagonally forward and diagonally upward. [Figure 6] It is a front view of the switch body illustrated in Fig. 5. [Figure 7] It is a side view of the switch body illustrated in Fig. 5. [Figure 8] It is a longitudinal cross-sectional view of the switch body illustrated in Fig. 5. [Figure 9] It is a diagram illustrating the switch body in a state where a housing is removed from the switch body illustrated in Fig. 4. [Figure 10] It is a diagram for explaining the functions and effects related to the arrangement position of a display unit included in the safety switch of the embodiment. [Figure 11] It is a diagram for explaining an overlapping state between an attraction surface of an electromagnet and an attracted surface of an actuator. [Figure 12] It is a block diagram for explaining an electrical configuration of a switch body included in the embodiment. [Figure 13] It is a functional block diagram of a first MCU illustrated in Fig. 12. [Figure 14] It is a functional block diagram of a second MCU illustrated in Fig. 12. [Figure 15] It is a list for explaining display modes of a display unit. [Figure 16] This diagram illustrates a method for determining whether or not the adsorption surface and the surface to be adsorbed are in close contact. [Figure 17] This is a longitudinal cross-sectional view of the actuator included in the embodiment. [Figure 18] Figure 17 is a diagram illustrating the operation of the compression coil spring included in the actuator shown in the figure, where (I) is a plan view of the compression coil spring, (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 when a load is applied. [Figure 19] The diagrams illustrate the process of aligning the orientation of the attracting surface with the orientation of the surface to be attracted in the safety switch of the embodiment. (I) shows the standby state of the actuator when the door is open. (II) shows the state in which the surface to be attracted moves forward towards the attracting surface under the attractive force of the permanent magnet when the actuator approaches the electromagnet during the door closing process. (III) shows the state in which the surface to be attracted is in close contact with the attracting surface under the attractive force of the permanent magnet. [Figure 20] These are longitudinal cross-sectional views of the actuator included in the embodiment, where (I) shows the standby state, (II) shows the state in which the surface to be attracted has advanced to its maximum extent by the forward movement mechanism, and (III) shows the state in which the orientation of the surface to be attracted has changed by the oscillation mechanism. [Figure 21] This flowchart explains how the electromagnet's power supply remains OFF during the process of the orientation of the surface to be attracted to aligning with the orientation of the magnet, and how the electromagnet's power supply is turned ON after the surface to be attracted to the magnet is in close contact with the magnet, using this as one of the conditions. [Figure 22] This is a diagram illustrating the configuration of a first modified example of the present invention. [Figure 23] This is a diagram illustrating the configuration of a second modified example of the present invention. [Figure 24] This is a diagram illustrating the configuration of a third modified example of the present invention. [Figure 25] This is a diagram illustrating the configuration of a fourth modified example of the present invention. [Modes for carrying out the invention] [Examples]

[0017] A preferred embodiment of the present invention will be described below based on the attached drawings. Figure 1 is an explanatory diagram of an opening / closing door and a protective fence, which are part of the partition system 1 and are equipped with the safety switch of the embodiment, i.e., a safety switch with an electromagnetic locking mechanism. Figure 2 is a cross-sectional view taken along the line II-II in Figure 1. In the figure, reference numeral PF indicates the protective fence and reference numeral PD indicates the opening / closing door. Figure 1 is an explanatory diagram of the partition system 1 as seen from outside the working area S partitioned by the partition system 1. The partition system 1 consists of a protective fence PF as a fixed partition part, a door PD which constitutes a movable part that can move relative to the fixed partition part, and a safety switch 100. The partition system 1 maintains the working area S in a safe state by restricting the operation of devices inside the working area S based on the safety-related output output by the safety switch 100. In this embodiment, the safety switch 100 is located inside the working area S. The protective fence PF constitutes the fixed partition part of the partition system 1 that partitions the working area S in which the devices operate. The opening into which the door PD, which constitutes the movable part relative to the fixed partition part, is installed is formed by a door opening frame 2. Referring to Figure 1, one side of the door PD, which constitutes the movable part, is provided with a plurality of hinges 4 spaced apart vertically, and these hinges 4 are attached to the vertical frame portion 2a of the door opening frame 2. In other words, the door PD is a single-leaf door.

[0018] Referring to Figures 1 and 2, the door PD consists of a door frame 6 and a transparent board 8 surrounded by the door frame 6. A hinge 4 is attached to one side of the door PD, and a door operating part 10 is attached to the other side (Figure 1). By operating the door operating part 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.

[0019] Figure 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 Figure 2, the operating area S, demarcated by the protective fence PF and the opening / closing door PD, is the area located to the right of the protective fence PF and the door PD on the plane of Figure 2. The safety switch 100 is positioned on the operating area S side relative to the closed door PD. By positioning the safety switch 100 on the operating area S side relative to the door PD when the door PD is closed, the safety switch 100 is positioned inside the operating area S. Referring to Figure 2, the safety switch 100 consists of a switch body 102 and an actuator 104. The switch body 102 is positioned inside the operating area S. Specifically, the switch 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 body 102 includes an electromagnet 130 having a suction 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, or in other words, faces outward from the operating area S. Figure 2 shows three arrows X, Y, and Z indicating mutually orthogonal directions, which correspond to the positioning of the safety switch 100, as will be described later.

[0020] The switch body 102 of the safety switch 100 in this embodiment includes an electromagnet 130 (Figure 8) and a substrate housing 132, as will be explained later with reference to Figure 7 and the like. The substrate housing 132 houses substrates Cb(1) and Cb(2) (Figures 8 and 9).

[0021] On the other hand, the actuator 104 is positioned on the side of the door frame 6 that faces the operating area S, and is specifically fixed to the upper frame portion 6a of the door frame 6 via the second bracket 108 (Figure 2). Both the door opening frame 2 and the door frame 6 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.

[0022] The door PD relates to the opening and closing door described in Patent Document 2. On the other hand, Figure 3 shows a box-shaped device 500 that houses a work system. In Figure 3, three devices 500 are arranged side by side. Each device 500's box 502 is fitted with a double-hinged opening and closing door 506, which is an example of a door PD, so that an operator can manually access the device 504 installed inside. In relation to the opening and closing door 506, a safety switch 100 can be installed on the box-shaped device 500.

[0023] Hereinafter, an embodiment of the present invention will be described based on an example applied to the door PD disclosed in Figures 1 and 2, as a typical example. Figure 4 is a substantial front view of the actuator 104 included in the safety switch 100, and is a diagram for illustrating the front shape of the actuator 104. The actuator 104 is mainly composed of an iron piece 120 which is a magnetizing member, and includes a plastic molded product 122, an actuator communication unit 124, and a mounting bracket 126 as an actuator mounting part. The iron piece 120 is circular in front view and has an adsorption surface 130a and an adsorption surface 120a on its front side. The diameter of the iron piece 120 is indicated by reference numeral D1. The iron piece 120 is attached to the plastic molded product 122. The periphery of the iron piece 120 is covered by the plastic molded product 122, and the actuator communication unit 124 is arranged in a manner that is concealed by this plastic molded product 122. The mounting bracket 126 is provided on the plastic molded product 122 on the side opposite to the iron piece 120 and has a shape that extends left and right on the plane of Figure 4. The mounting bracket 126 is provided with a pair of mounting holes through which screws for fastening the mounting bracket are inserted in the part visible from the front of the actuator 104. This pair of mounting brackets 126 is fastened to the second bracket 108, and the actuator 104 is fixed to the door PD via the second bracket 108 (Figure 2). When the door PD is closed, the relative positional relationship between the actuator 104 and the switch body 102 is such that the actuator 104 is located on the side of the door frame 6 that faces the operating area S. That is, when the door PD is closed, the actuator 104 is installed on the door frame 6 such that the suction surface 120a of the iron piece 120 faces the operating area S. 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 it is also possible to have a configuration in which the mounting bracket 126 is directly fastened to the door frame 6 and the actuator 104 is fixed to the door PD.

[0024] A specific example of how the actuator 104 is fixed to the door PD will be described based on the arrangement example shown in Figure 2. As mentioned 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 in the lateral direction, that is, in the longitudinal direction of the upper frame portion 6a. In this installation example, the reference numeral Ha in Figure 4 indicates the height of the circular iron piece 120 included in the actuator 104 when viewed from the front. In the installation example in Figure 2, the actuator 104 is fixed to the door frame 6 with the direction of the height Ha aligned with the direction of the width Wdf of the upper frame 6a. The height Ha of the actuator 104 is equal to or less than the average width Wdf of the rectangular cross-section door frame 6 (Figure 2). A part of the actuator 104 installed on the door frame 6 may protrude to the inside of the door frame 6, that is, to the part of the transparent board 8, but it is desirable that this protrusion be as small as possible. This reduces the interference caused by the actuator 104 during the operation.

[0025] 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, the electromagnetic locking mechanism of a safety switch has historically been developed following the technical concept of the lock pin mechanism. The design concept of the safety switch 100 with an electromagnetic locking mechanism of this embodiment will now be explained. Generally speaking, when considering the role of a safety switch, the fundamental requirement of maintaining a safe environment in the operating area where the operating device is located is achieved 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 running in the operating area. Therefore, it can be said that the door lock function only needs to be able to keep the device running in the operating area. In other words, the basic requirement for the door lock function of a safety switch is to prevent the door from being opened unintentionally while the device is in operation. This is because if the door is opened unintentionally, the operation of the device in the operating area will be restricted by the function of the safety switch, which is to maintain a safe environment 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 device within the operating area S (Figure 2) or box 502 (Figure 3) from being interrupted by the unintentional opening of the doors PD, 506.

[0026] Traditionally, the door lock function of safety switches has been designed to contribute to maintaining a safe environment within the operating area. For this reason, electromagnetic locking mechanisms have employed electromagnets with a magnetic force strong enough to prevent the door from opening even with relatively strong operating force. However, if the role of the door lock function is to keep the device running rather than to maintain a safe environment, then the magnetic force of the electromagnet used in safety switches with electromagnetic locking mechanisms may be the same as before, or it may be weaker. When an operator opens the door PD, the operating force required to open the door PD should be such that it can at least prompt the operator to ask, "Are you opening the door PD now, or is this as you intended?" This prevents the door from opening unintentionally. If a certain operating force that can confirm the operator's intention is required to open the door PD is determined by the electromagnet, then unintentional opening of the door PD can be prevented without requiring any further operating force.

[0027] Therefore, although optional, the degree of magnetic force of the electromagnet 130 can be made weaker than conventional methods. For example, if the door PD is equipped with an operating part such as a doorknob, the door latch is released when an operating force is applied to the doorknob to rotate it, but the electromagnet 130 is used with a magnetic force at least stronger than the operating force required to release the door latch. This can deter the operator from opening the door PD and prevent accidental opening of the door PD. This also prevents unexpected interruptions in the operation of the device that occur due to the accidental opening of the door PD, 506.

[0028] Referring to Figure 5, the switch body 102 has screw holes 130c as mounting parts for fixing the switch body 102 to the door opening frame 2, which is a fixed part of the partitioning system 1. More specifically, the electromagnet 130 has a projection 130b that protrudes outward from the center of the suction surface 130a, and the screw holes 130c are provided in the projection 130b. As illustrated in the arrangement example in Figure 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 with an L-shaped cross-section (Figure 2). As illustrated in the arrangement example in Figure 2, the projection 130b is located protruding from the upper part of the electromagnet 130, and the flat top surface of the projection 130b constitutes a mounting surface, and the screw holes 130c are provided in the mounting surface. This mounting surface may be formed on the side surface of the electromagnet 130.

[0029] For example, Figure 5 shows arrows X, Y, and Z indicating three mutually orthogonal directions. The directions indicated by arrows X, Y, and Z all correspond to the orientation of the safety switch 100, and are called the X-axis direction, Y-axis direction, and Z-axis direction, respectively. The Y-axis direction indicates the normal direction of the suction surface 130a of the electromagnet 130. The Z-axis direction is perpendicular to the Y-axis direction and parallel to the suction surface 130a, and indicates the direction in which the protrusion 130b protrudes relative to the center of the suction surface 130a. The X-axis direction indicates the direction parallel to the suction surface 130a and perpendicular to the Z-axis. In this embodiment, as shown in Figure 2, the safety switch 100 is positioned so that the suction surface 130a faces the closed door PD, so the normal direction of the closed door PD coincides with the Y-axis direction. Furthermore, in this embodiment, the safety switch 100 is positioned such that the direction in which the protruding portion 130b protrudes relative to the center of the suction surface 130a is perpendicular to the extension direction of the upper frame portion 6a of the closed door PD 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 relative 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 toward the suction surface 130a from the closed door PD may be referred to as "rearward," and the opposite direction as "forward," and in the Z-axis direction, the direction toward the protruding portion 130b from the suction surface 130a may be referred to as "upward," and the opposite direction as "downward."

[0030] Figures 5 through 9 are diagrams relating to the switch body 102. Figure 5 is a perspective view of the switch body 102. Figure 6 is a front view. Figure 7 is a side view. As can be clearly seen from Figures 5 and 7, the switch body 102 has an overall shape that is roughly cylindrical and extends in the Y-axis direction (normal direction of the suction surface 130a). The switch body 102 has an electromagnet 130 which includes a suction surface 130a that constitutes one end face in the Y-axis direction. The length L from the suction surface 130a to the other end face is longer than the diameter of the suction surface 130a.

[0031] The suction surface 130a constitutes the main part of one end face of the switch body 102. Referring specifically to Figures 5 to 7, in the figures, reference numeral Hg indicates the housing of the substrate housing 132. When the electromagnet 130 has a housing Hg around it, the suction surface 130a protrudes beyond the end face Hg(a), which is part of the housing Hg and extends to the electromagnet 130, and this suction surface 130a constitutes one end face of the switch body 102. As mentioned above, when the door PD is closed, the suction surface 130a faces the surface 120a of the actuator 104 that is to be attracted.

[0032] As shown in Figure 5, the switch body 102 comprises a housing Hg including a substrate housing section 132 for housing a substrate, and a display section 142 that displays information corresponding to safety-related outputs output from the safety switch 100 based on the detection results of the actuator 104. The substrate housing section 132 is located on the opposite side of the magnetic attraction surface 130a of the electromagnet 130 in the Y-axis direction. In other words, the substrate housing section 132 is located behind the electromagnet 130. Therefore, the dimensions of the entire switch body 102 in the X-axis direction and the Z-axis direction are not likely to be larger than the dimensions of the electromagnet 130 in the X-axis direction and the Z-axis direction. Also, the display section 142 is located on the opposite side of the magnetic attraction surface 130a of the electromagnet 130 in the Y-axis direction, i.e., behind the electromagnet 130, within the housing Hg. The switch body 102 has a shape in which the dimensions in the Y-axis direction are larger than either the dimensions in the X-axis direction or the dimensions in the Z-axis direction. Therefore, compared to other switch bodies requiring similar capacity, the area it occupies in the opening formed in the door opening frame 2 when viewed from the front tends to be smaller.

[0033] Figure 6 is a front view of the switch body 102 as seen from the front. The plane normal direction of Figure 6 is parallel to the Y-axis direction. As described above, the substrate housing 132 is located behind the electromagnet 130. Therefore, when the switch body 102 is viewed from the front, as shown in Figure 6, most of the housing Hg having the substrate housing 132 is hidden by the electromagnet 130. Thus, the increase in the area occupied by the switch body 102 when 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 suction surface 130a is small.

[0034] As shown in Figure 6, when viewed from the front, the area occupied by the housing Hg is such that the area on the side of the suction surface 130a where the screw holes 130c are provided is larger than the area on the opposite side of the suction surface 130a where the screw holes 130c are provided. In other words, in a front view, most of the housing Hg is located above the center of the suction surface 130a. When the switch body 102 is fixed by the screw holes 130c, a dead space is created between the maximum dimension of the suction surface 130a in the X-axis direction and the door opening frame 2 to which the switch body 102 is attached. This dead space is utilized in the area where the housing Hg is provided, so that the workability through the door opening frame 2 is not reduced. Therefore, by configuring the housing Hg so that the area occupied by the housing Hg in a front view is larger on the side of the suction surface 130a where the screw holes 130c are provided, the workability through the door opening frame 2 to which the switch body 102 is located is ensured.

[0035] Figure 7 is a side view of the switch body 102. The switch body 102 has a substrate housing portion 132 on the side opposite to the suction surface 130a with respect to the electromagnet 130 (Figure 8). Reference numeral Hg indicates the housing of the substrate housing portion 132. A connector connection portion 144 is provided on the rear end face 134 of the substrate housing portion 132, on the side opposite to where the suction surface 130a is located in the Y-axis direction (Figures 7 and 8). The rear end face 134 is also the end face of the switch body 102 opposite to where the suction surface 130a is located. The connector connection portion 144 extends in the direction away from the suction surface 130 along the Y-axis direction. By providing the connector connection portion 144 on the end face 134 of the substrate housing portion 132, it is not necessary to position the cable connected to the connector connection portion 144 around the switch body 102. Furthermore, since the connector connection portion 144 is located on the end face 134 of the circuit board housing portion 132, at least the portion of the cable connected to the connector connection portion 144 that is close to the connector connection portion 144 is located behind the switch body 102. Therefore, the risk of the cable reducing the visibility of the display portion 142 from the front is reduced. In addition, by routing the cable connected to the connector connection portion 144 behind the switch body 102, or by routing it upwards 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, thus reducing the workability of work performed through the door opening frame 2.

[0036] Figure 8 is a longitudinal cross-sectional view of the switch body 102 cut along the Z-axis. Figure 9 is a diagram illustrating the arrangement of the two circuit boards Cb(1) and Cb(2) located in the circuit board housing 132. Figure 9 is a perspective view of the switch body 102 from the front at an oblique angle, with the housing Hg removed and the housing 132 exposed. Figure 10 is an exploded perspective view of the electromagnet 130 and housing Hg, showing the switch body 102 from the rear.

[0037] Referring to Figure 9, although not particularly limited, the protrusion 130b is formed by raising a portion of the yoke section of the electromagnet 130. In the example arrangement shown in Figure 2, the protrusion 130b is mounted at the top, but it is also possible to mount the switch body 102 so that the mounting portion 103b is positioned to the side.

[0038] As can be seen in Figures 5 and 8, the mounting portion 130b protruding in the Z-axis direction has two screw holes 130c spaced apart in the Y-axis direction, and is fixed to the L-shaped first bracket 106 using screws Sc that are screwed into these two screw holes 130c (Figure 2).

[0039] Referring to Figures 8 and 9, the substrate housing section 132 houses a first substrate Cb(1) and a second substrate Cb(2), which are arranged orthogonally. Specifically, the first substrate Cb(1) is positioned with its surface aligned with the Y-axis, and the second substrate Cb(2) is positioned with its surface aligned with the Z-axis. The second substrate Cb(2) is positioned at the rear end of the first substrate Cb(1), preferably hanging down from the first substrate Cb(1) as shown in Figure 8.

[0040] As described above, the switch body 102 has at least a display unit 142 (Figures 2, 5, and 7) that displays information corresponding to the safety-related output output by the switch body 102. The display unit 142 is positioned so as to be visible from the opposite side of the switch body 102 from the side where the screw holes 130c, which serve as mounting parts, are located. In other words, it is positioned so as to be visible from the side where there is no mounting surface formed by the top surface of the protruding part 130b. When the switch body 102 is fixed to the door opening frame 2, the screw holes 130c are positioned and fixed so as to face outward from the opening formed in the door opening frame 2. For this reason, the side opposite to the side where the screw holes 130c are provided faces inward from the opening. In the example in Figure 2, the switch body 102 is fixed to the upper horizontal frame portion 2b of the door opening frame 2, so the direction outward from the opening is upward. And, in the upper horizontal frame portion 2b, the inside of the opening is downward, so 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 to the side where the hinge 4 is provided (the right-hand frame portion on the page of Figure 1), the display portion 142 will be located on the left side on the page of Figure 1. By providing the display portion 142 on the opposite side of the screw hole 130c in this way, the display portion 142 faces the side of the door opening frame 2 opposite to 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 on the inside of the opening, so the switch body will be visible from the inside of the opening. For this reason, by positioning the display portion 142 on the inside of the opening when it is fixed to the door opening frame 2, the visibility of the display portion 142 is improved.

[0041] As can be clearly seen in Figure 7, the display unit 142 has a shape that extends continuously in the circumferential direction of the switch body 102, and extends from the side opposite to the mounting portion 130b in the Z-axis direction to the middle portion in the Z-axis direction of the sides facing each other in the X-axis direction. As a result, an operator looking into the operating area S from the outside can see the display unit 142 not only from below but also from the side, as explained in the installation example in Figure 2. This visibility can be improved by having the display unit 142 have a curved cross-sectional shape, as disclosed in Figure 7, and by having the display unit 142 have a shape that extends continuously in the circumferential direction of the switch body 102. Furthermore, in order to improve visibility, as can be clearly seen in Figure 7, the outer surface of the display unit 142 has a shape that tapers toward the suction surface 130a in the Y-axis direction.

[0042] Referring to Figure 8, in the substrate housing section 132, a limited illumination space Ls is formed by a first substrate Cb(1) whose surface extends front to back, i.e., along the Y-axis, and a second substrate Cb(2) whose surface extends along the Z-axis. Light from the LED 150 mounted on the second substrate Cb(2) is emitted toward this limited illumination space Ls, and as a result, it is displayed through the light-transmitting material that constitutes part of the display section 142 and part of the housing Hg. Of course, the LED 150 that constitutes the light source may also be provided on the first substrate Cb(1).

[0043] As mentioned above, the switch body 102 is located inside the operating area S. The illumination status of the display unit 142 can be seen from the outside of the opening / closing door PD through the transparent board 8 (Figure 2) of the opening / closing door PD. The visibility of the display unit 142 when looking at the switch body 102 from the outside will be explained with reference to Figure 10. Figure 10 is a schematic diagram created to explain the visibility of the display unit 142. In the figure, the reference numeral Ey represents the operator's eye.

[0044] In Figure 10, reference numeral 142-1 indicates a display unit located near the suction surface 130a. That is, the distance D-1 in the Y-axis direction between the suction surface 130a and the display unit 142-1 is relatively small. Reference numeral 142-2 indicates a display unit located distal to the suction surface 130e. The distance D-2 in the Y-axis direction between the suction surface 130a and the display unit 142-2 is relatively large. As can be seen from Figure 10, the visibility of the display unit 142 when viewed from the outside through the opening / closing door PD is better when it is positioned distal to the suction surface 130a rather than proximal to it. Preferably, the display unit 142 is positioned behind the intermediate line Imd, which includes an intermediate line Imd that is half the length of the total length L (Figure 5) of the switch body 102 in the Y-axis direction.

[0045] The main body of the first circuit board Cb(1) is equipped with a control circuit for generating drive signals for the electromagnet 130, a power supply circuit, a communication circuit for the actuator 104, and the like. On the other hand, the second circuit board Cb(2) is equipped with an indicator light control circuit and the like.

[0046] Referring to Figure 9, in the substrate housing section 132, the first substrate Cb(1), whose surface extends along the Y-axis, has a pair of elongated left and right substrate extensions Cb(1ex) that extend along the Y-axis from the main body Cb (main body) located in the substrate housing section 132 and on which the control circuit etc. is mounted, to the vicinity of the suction 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 height dimension of the switch body 102 in the Z-axis direction from increasing due to the presence of the substrate extensions Cb(1ex). In addition, a part of the substrate extensions Cb(1ex) is positioned to overlap with the electromagnet 130 when viewed in the Z-axis direction. Therefore, the increase in the dimensions of the switch body 102 in the Z-axis and X-axis directions due to the presence of the substrate extensions Cb(1ex) can be reduced.

[0047] In a pair of substrate extensions Cb(1ex), a sensor-side coil (antenna coil) 152 is mounted at the tip of one of the substrate extensions Cb(1ex) (Figure 9). The sensor-side coil 152 constitutes a detection unit that detects whether the actuator 104 is within a predetermined range relative to the switch body 102. By mounting the sensor-side coil 152 at the tip of one of the substrate extensions Cb(1ex), the sensor-side coil 152 can be positioned closer to the suction surface 130a in the Y-axis direction. As a result, the detection capability of the sensor-side coil 152 can be increased. As is well known, this sensor-side coil 152 is positioned in correspondence with the actuator communication unit 124 of the actuator 104 described above. In this case, 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, not metal. For this reason, on the surface of the switch body facing the actuator 102, a part of the housing Hg exists in addition to the suction surface 130a. In this embodiment, as described above, by placing a portion of the housing Hg in a dead space, it is possible to maintain workability through the door opening frame 2 where the switch body 102 is located.

[0048] For example, in the process of closing the door PD, the iron piece 120 of the actuator 104 approaches the suction surface 130a of the switch body 102 in conjunction with the closing operation of the door PD, and then the iron piece 120 overlaps with the suction surface 130a of the switch body 102. The diameter D1 (Figure 4) of the iron piece 120 (suction surface 120a) is designed to be larger than the diameter D2 of the suction surface 130a. Based on the normal state in which the iron piece 120 overlaps with the switch body 102, that is, the normal state in which the center O1 of the iron piece 120 and the center O2 of the suction surface 130a are aligned, the diameter D1 of the iron piece 120 is set relative to the diameter D2 of the suction surface 130a so that the outer edge of the suction surface 130a is located within the suction surface 120a of the iron piece 120. As a result, even if the switch body 102 and / or actuator 104 undergo an acceptable relative displacement, the switch body 102 can fix the actuator 104 with a predetermined suction force.

[0049] When the door PD is closed, that is, when the sensor-side coil 152 detects the actuator communication unit 124, and other conditions are met, a safety-related output is output to a PLC, for example, which controls the device installed in the operating area S (Figure 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 the signal from the sensor-side coil (antenna coil) 152.

[0050] Figure 12 is a block diagram illustrating the electrical configuration of the switch body 102. The control circuit 200 of the switch 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.

[0051] The first MCU 202 is connected to the transmitting circuit 206. The transmitting circuit 206 is connected to the sensor-side coil (antenna coil) 152. The sensor-side coil 152 is connected to the receiving circuit 208. The receiving circuit 208 is connected to both the first MCU 202 and the second MCU 204. The first MCU 202 drives the sensor-side coil 152 via the transmitting 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 such that the coil is located in the part covered by the plastic molded product 122, as shown in Figure 4. The first MCU 202 and the second MCU 204 receive the wireless signal 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 the induced current generated in the sensor-side coil 152 as its power source. 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.

[0052] Referring to Figures 13 and 14, the measurement unit 210a of the first MCU 202 and the measurement unit 210b of the second MCU 204 measure the strength of the wireless signal received from the actuator communication unit 124 via the sensor-side coil 152 and the receiving circuit 208, respectively, and estimate the distance d 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 determine whether the estimated distance d is below a threshold, that is, whether the actuator 104 is within a predetermined range relative to the switch body 102. In other words, a detection unit that detects whether the actuator 104 is within a predetermined range relative 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. Alternatively, 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 the information carried by the wireless signal from the actuator communication unit 124, which is 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.

[0053] The safety determination circuit 214a of the first MCU 202 determines whether two conditions are met, based on the measurement by the measurement unit 210a and the identification by the demodulation unit 212a: that the estimated distance d is below a threshold, and that the actuator 104 is identified as a predetermined actuator. It then transmits the determination result to the second MCU 204. More specifically, the determination result can be either that both conditions are met, or that 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, based on the measurement by the measurement unit 210b and the identification by the demodulation unit 212b: that the estimated distance d is below a threshold, and that the actuator 104 is identified as a predetermined actuator. It then transmits the determination result to the first MCU 202. The safety determination circuit 214a of the first MCU 202 outputs a safety-related output when its own determination result matches the determination result of the second MCU, determining that the actuator 104, which is identified as a predetermined actuator, is within a predetermined range relative to the switch body 102, i.e., the door PD is closed. Similarly, the safety determination circuit 214b of the second MCU 204 determines that the actuator 104, which is identified as a predetermined actuator, is within a predetermined range relative to the switch body 102, i.e., the door PD is closed, when its own determination result matches the determination result of the first MCU. In this embodiment, as will be described later, the first MCU 202 and the second MCU 204 output safety-related outputs via OSSD (Output Signal Switching Device) when the conditions related to the signal input via the input circuit 220 are also met. However, safety-related outputs may also be output based on the 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. However, it is also possible that only the distance d is estimated, and the safety determination circuits 214a and 214b do not make a determination regarding the identification of the actuator 104, but instead output the determination result of whether the distance d is below a threshold to the other safety determination circuit.

[0054] Returning to Figure 12, the input circuit 220 has a first safety input section 222, a second safety input section 224, and a lock input section 226. Other devices capable of outputting safety-related outputs are connected to the first safety input section 222 and the second safety input section 224. In other words, the first safety input section 222 and the second safety input section 224 are input circuits for daisy-chaining the switch body 102 with other devices. For example, one terminal for outputting a safety-related output from the other device is connected to the first safety input section 222, and the other terminal for outputting a safety-related output from the same device is connected to the second safety input section 224.

[0055] The lock input unit 226 is connected to an external control device such as a safety PLC or safety control equipment, and receives a lock signal for controlling the lock mechanism output by 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. In other words, the door PD is locked by magnetic force in accordance with 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 it 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 met. 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 closed state of the door PD by the lock signal output by the external control device.

[0056] The control circuit 200 includes a first OSSD 230a and a second OSSD 230b as switching devices 230. The first MCU 202 outputs safety-related outputs via the first OSSD 230a, and the second MCU 204 outputs safety-related outputs via the second OSSD 230b. The external devices that output safety-related outputs 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 partition system 1.

[0057] The first OSSD230a and the second OSSD230b are composed of, for example, PNP type transistors. When the PNP type transistor is turned ON, the + side power supply is connected to the output terminal, so an ON signal is output. On the other hand, when the PNP type transistor is turned OFF, the output terminal is grounded via a pull-down resistor, so an OFF signal is output.

[0058] The first OSSD230a and the second OSSD230b may each be connected to an OSSD monitoring circuit 232. The OSSD monitoring circuit 232 is connected to the first MCU202 and the second MCU204. The first MCU202 monitors whether the operation of the second OSSD230b is normal through the OSSD monitoring circuit 232. The second MCU204 monitors whether the operation of the first OSSD230a is normal through the OSSD monitoring circuit 232. For example, when the first OSSD230a and the second OSSD230b output an ON signal, they each periodically transition the output signal to OFF for a very short time. If the OSSD monitoring circuit 232 can detect a very short OFF period during the ON signal output period, it determines that the OSSD is normal; if it cannot detect a very short OFF period, it determines that the OSSD is not normal.

[0059] If the OSSD monitoring circuit 232 fails to detect a minute-long OFF state and the ON signal continues, this is due, for example, to a short circuit between the output terminal and the + side 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 output an OFF signal. As a result, the first OSSD 230a and the second OSSD 230b that are functioning normally will output an OFF signal. The transition of safety-related outputs to OFF for monitoring purposes by the OSSD monitoring circuit 232 is set to a minute time so that external devices that output safety-related outputs do not react to the OFF state.

[0060] 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 that require power, such as the control circuit 200, the sensor coil 152, and the display unit 142. However, if the voltage supplied from the external power supply or the voltage output from the power supply circuit 240 is not within a predetermined range, the control circuit 200 and other components may not operate correctly. Therefore, the power supply monitoring circuit 242 determines whether the voltage supplied from the external power supply is within a predetermined range, and also determines whether the voltage output from the power supply circuit 240 is within a 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 correctly, they turn off safety-related outputs, regardless of the control signals output from the control circuit 200. When the first OSSD230a and the second OSSD230b receive a result indicating that the power supply circuit 240 is operating normally, they each output safety-related outputs depending on the control signals output from the control circuit 200.

[0061] The control circuit 200 includes an indicator light control unit 252 that controls the display unit 142, and the indicator light control unit 252 of 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. Referring to Figure 15, the relationship between the ON / OFF status of the safety-related output and the determination results in the first MCU 202 and the second MCU 204 will be explained.

[0062] The "Indicator Lights" column in Figure 15 shows 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 subdivided into "OSSD," "Safety Input," "Lock Control Input," and "Actuator." The "OSSD" column indicates whether the safety-related output, which is output to an external control device via the first OSSD 230a and second OSSD 230b as switching devices 230, is ON or OFF. The "Safety Input," "Lock Control Input," and "Actuator" columns each indicate the determination items used to decide whether to set the safety-related output output via the switching device 230 to ON or OFF. The "Safety Input" column indicates whether the safety-related output input via the first safety input unit 222 and 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 it has been detected that actuator 104, which is identified as a predetermined actuator based on a wireless signal received via the sensor-side coil 152 and the receiving circuit 208, is within a predetermined range relative to the switch body 102.

[0063] As shown in Figure 15, in this embodiment, the safety-related output output via the switching device 230 turns ON when the safety-related outputs input via the first safety input unit 222 and the second safety input unit 224 are ON, the lock signal input via the lock input unit 226 is ON, and the actuator 104 is detected. At this time, the illumination pattern of the display unit 142 is green. When the actuator 104 is not detected, regardless of the safety-related outputs and lock signals input via the first safety input unit 222 and the second safety input unit 224, the safety-related output output via the switching device 230 turns OFF, and the illumination pattern of the display unit 142 turns red. In this embodiment, the safety switch 100 detects whether the actuator 104 is within a predetermined range relative 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 regardless of the input state of other signals, the safety-related output output via the switching device 230 turns OFF.

[0064] In this embodiment, the safety switch 100, in addition to detecting the actuator 104, also refers to the input status of various signals to determine whether to turn on or off the safety-related output output via the switching device 230. At this time, compared to the detection of the actuator 104, it is difficult for the operator to grasp the status of the safety-related output and lock signal input via the first safety input unit 222 and the second safety input unit 224. More specifically, whether or not the actuator 104 is detected is related to whether or not the door PD is closed, so if the actuator 104 is not detected and the safety-related output output from the switch body 102 via the switching device 230 is OFF, the operator can easily identify the cause. In contrast, regarding the safety-related output and lock signal input via the first safety input unit 222 and the second safety input unit 224, the operator can visually confirm whether or not the corresponding cables are connected, but it is difficult to visually grasp the status of the signals supplied via those cables. Therefore, in this embodiment, when the safety-related output output via the switching device 230 is OFF due to the input state of various signals, the illumination pattern of the display unit 142 is changed according to the input state of various signals, making it easier for the operator to identify the reason why the safety-related output output from the switch body 102 via the switching device 230 is OFF.

[0065] In this embodiment, since other devices capable of outputting safety-related outputs are connected to the first safety input unit 222 and the second safety input unit 224, the safety-related outputs output by the switch body 102 and the illumination pattern of the display unit 142 change depending on the "Safety Input" column in Figure 15. However, if no such other devices are connected, the safety-related outputs output by the switch body 102 and the illumination pattern of the display unit 142 may be determined according to 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 outputs output by the switch body 102 are turned ON, and the illumination pattern of the display unit 142 becomes green. Also, in this case, there are no cases where the illumination pattern of the display unit 142 is "orange" or "orange flashing", as shown in Figure 15.

[0066] As described above, the distance d (Figure 11) from the switch body 102 to the actuator 104 is estimated based on the strength of the wireless signal. If the distance d is within a predetermined range, an ID is obtained from the actuator communication unit 124, and after confirming that the obtained ID matches a recorded ID, a determination is made as to whether the electromagnet 130 and the iron piece 120 are in close contact.

[0067] Referring to Figure 16, the determination of whether the distance d2 is below the threshold will be explained in detail. The second MCU 204 supplies a test current to the electromagnet 130 and monitors the current flowing through the electromagnet 130 at this time. Figure 16(I) shows the 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 closed state of the door PD, that is, to form the locked state of the safety switch 100. If the same value of current as the locking current were used for testing, the electromagnet 130 would attract the iron piece 120 with an attractive force sufficient to maintain the closed state of the door PD even if the lock signal is not ON, which would hinder the operation of opening the door PD and reduce the worker's work efficiency. For this reason, by setting the value of the test current to a value smaller than the locking current, in particular to a weak value such that the electromagnet 130 exerts almost no attractive force, the worker's work efficiency can be maintained.

[0068] Figure 16(II) shows the monitoring current flowing through the electromagnet 130, corresponding to the rectangular wave test current in Figure 16(I), when the electromagnet 130 and the iron piece 120 are not in close contact, i.e., the distance d2 between the adsorption surface 130a and the surface to be adsorbed 120a is greater than the threshold. Figure 16(III) shows the monitoring current flowing through the electromagnet 130, corresponding to the rectangular wave test current in Figure 16(I), when the electromagnet 130 and the iron piece 120 are in close contact, i.e., the distance d2 between the adsorption surface 130a and the surface to be adsorbed 120a is less than or equal to the threshold. As can be seen by comparing (II) and (III) in Figure 16, when the electromagnet 130 and the iron piece 120 are in close contact, that is, when the distance d2 between the adsorption surface 130a and the surface to be adsorbed 120a is less than the threshold, the inductance is greater than when the distance d2 is greater than or equal to the threshold. Therefore, the time from when the test current is started to be supplied until the value of the monitoring current reaches a certain value is longer.

[0069] If the time from the start of supplying the test current until the value of the monitoring current reaches a certain value differs, the value of the current flowing through the electromagnet 130 at the time after a certain period of time has elapsed from the start of supplying the test current will differ. For comparison, Figures 16(II) and (III) illustrate the time after a certain period of time has elapsed from the start of supplying the test current to the electromagnet 130 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 adsorption surface 130a and the surface to be adsorbed 120a is greater than the threshold is the first monitoring current value I1 shown in Figure 16(II). Also, the value of the monitoring current flowing through the electromagnet 130 at the inspection confirmation timing when the distance d2 between the adsorption surface 130a and the surface to be adsorbed 120a is less than or equal to the threshold is the second monitoring current value I2 shown in Figure 16(III). Comparing the first monitoring current value I1 and the second monitoring current value I2, the first monitoring current value I1 is larger. In other words, a monitoring current that takes a short time to reach a certain value from the time the test current is supplied (Figure 16 (II)), or in other words, a monitoring current with high responsiveness, will have a larger current value at the inspection confirmation timing compared with a monitoring current with low responsiveness (Figure 16 (III)). Therefore, by comparing the values ​​of the monitoring current at the inspection confirmation timing, it is possible to determine the responsiveness of the monitoring current flowing through the electromagnet 130, the magnitude of the inductance related to the responsiveness, and the length of the distance d2 between the adsorption surface 130a and the surface to be adsorbed 120a, which is related to the magnitude of the inductance. More specifically, a threshold value for the current is set at least between the first monitoring current value I1 and the second monitoring current value I2 so that the relationship between the distance d2 and the threshold can be determined, and it is determined whether the distance d2 is greater than or less than the threshold depending on whether the current value of the monitoring current at the inspection confirmation timing is greater than or less than the threshold.

[0070] Figure 17 is a longitudinal cross-sectional view of the actuator 104. Figure 17 shows the actuator 104 attached to a door PD, which is mounted parallel to the door opening frame 2 to which the switch body 102 is attached in the configuration of Figure 2, so as shown in Figure 2. Therefore, the normal direction of the door frame 6 (PD) coincides with the Y-axis direction, which is the normal direction of the attraction surface 130a of the electromagnet 139 of the switch body 102. Furthermore, in the actuator 104 of Figure 19, the normal direction of the attraction surface 120a of the iron piece 120 of the actuator 104 coincides with the Y-axis direction.

[0071] Referring to Figure 17, the aforementioned mounting bracket 126 constitutes the base member of the actuator 104. The mounting bracket 126 has a U-shaped cross-section with flanges at 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 at the center of its surface to be attracted 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, and this configuration constitutes a movement mechanism that moves the surface to be attracted 120a relative to the mounting bracket 126.

[0072] 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 the sleeve 322. The sleeve 322 has a length in the axial direction of the movable pin 320 and has a flange at one end 322a and a flange at the other end 322b, both extending radially outward and circumferentially. The flanges at the one end 322a and the other end 322b of the sleeve 322 are used to keep the position of the iron piece 120 constant relative to the movable pin 320, and the iron piece 120, the movable pin 320, and the sleeve 322 move relative to the mounting bracket 126.

[0073] The movable pin 320 and sleeve 322 are such that the outer surface of the sleeve 322 is guided by the through hole 126a, allowing the movable pin 320 to move in the axial direction. 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. That is, the diameter of the sleeve 322 is smaller than the diameter of the through hole 126a, and the sleeve 322 is loosely fitted into the through hole 126a. This configuration provides a swinging mechanism that swings the surface to be attracted 120a.

[0074] A compression coil spring 324 is provided between the flange 322a at one end 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 suction surface 120a toward the door frame 6, i.e., toward the retraction direction.

[0075] Figure 18(I) is a plan view of the compression coil spring 324. Figure 18(II) is a side view of the compression coil spring 324 in an unloaded state. Figure 18(III) is a side view of the compression coil spring 324 in a compressed state under load. As can be seen from Figure 18(I), the compression coil spring 324 is composed of a trapezoidal spiral spring in side view, with a diameter that gradually decreases in the axial direction. This spiral-shaped compression coil spring 324 can become flat in side view when compressed. Therefore, the range of motion of the movable pin 320 when moving in the direction in which the compression coil spring 324 is compressed is widened.

[0076] In this embodiment, the state of the actuator 104 shown in Figure 17, that is, the state in which the iron piece 120 is moved toward the door frame 6 by the compression coil spring 324, in other words, toward the electromagnet 130, is defined as the standby state, and the position of the iron piece 120 in this state is defined as the standby position. Examples of variations of the compression coil spring 324 include disc springs and elastic materials such as rubber.

[0077] A cushioning member 326 is provided between the flange 322b at the other end of the sleeve 322 and the mounting bracket 126 and the iron piece 120 (Figure 17). As will be explained later, the impact when the iron piece 120 overlaps with the adsorption surface 130a of the electromagnet 130 based on the attractive force of the permanent magnet 120b is mitigated by the compression coil spring 324 and the cushioning material 326.

[0078] Figure 19 is a diagram illustrating the operation of actuator 104. Figure 19(I) shows actuator 104 in standby mode and corresponds to Figure 17. In Figure 19, actuator communication unit 124 indicates the position of the actuator coil included in actuator communication unit 124.

[0079] Figure 19(II) illustrates the process of the door PD closing from an open state, that is, the process of an operator closing the door PD, where the actuator 104 approaches the magnetic attraction surface 130a of the electromagnet 130 on the switch body 102 as the door PD closes. At this time, the electromagnet 130 is not driven. As shown in Figure 19(II), when the actuator 104 approaches the electromagnet 130, the attractive force of the permanent magnet 120b on the actuator 104 acts on the magnetic 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 away from the door frame 6, that is, towards the magnetic attraction surface 130a, together with the actuator housing 122. Therefore, for example, when the door PD is closed and the distance between the actuator 104 and the switch body 102 becomes within a certain range, the movable pin 320 and the iron piece 120 move along the Y-axis direction toward the suction surface 130a, together with the actuator housing 122. With this configuration, the relative position of the surface to be suctioned 120a with respect to the mounting bracket 126 is offset toward the suction surface 130a when the actuator 104 is within a predetermined range relative to the switch body 102, compared to when the actuator 104 is outside that range relative to the switch body 102. As a result, a state of close contact between the surface to be suctioned 120a and the suction surface 130a is easily achieved. Furthermore, with this configuration, the actuator communication unit 124 is offset toward the suction surface 130a along with the surface to be suctioned 120a with respect to the mounting bracket 126. In other words, regardless of the position of the surface to be attracted 120a on the actuator 104, the distance between the actuator communication unit 124 and the sensor-side coil 152 when the attraction surface 130a and the surface to be attracted 120a come into contact remains constant. Therefore, it is possible to determine whether the actuator 104 is within a predetermined range relative to the switch body without having to set a threshold that is compared with distance d according to the position of the surface to be attracted 120a on the actuator 104.

[0080] Figure 19(III) shows the state in which the surface to be attracted 120a and the attracting surface 130a are in close contact due to the attractive force of the permanent magnet 120b after going through the process in (II) above. In this state, the threshold for 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 below the threshold, that is, so that in this state 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 of Figure 19(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 surface to be attracted 120a and the attracting surface 130a are in close contact. When it is determined that the surface to be attracted 120a and the attracting surface 130a are in close contact, the second MCU 204 drives the electromagnet 130 to attract the iron piece 120 so that the door PD remains closed. In this embodiment, when the door PD is closed, the iron piece 120 moves toward the suction surface 130a due to the attractive force of the permanent magnet 320 of the actuator 104, causing the suction surface 130a and the surface to be attracted 120a to come into close contact. However, the movement of the iron piece 120 toward the suction surface 130a may be achieved by other means. For example, the iron piece 120 may move toward the suction surface 130a due to the inertia when the door PD is closed, i.e., 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 closed state of the door PD, and the iron piece 120 may move toward the suction surface 130a due to this attractive force.

[0081] Figure 20 is a cross-sectional view illustrating the state changes of the actuator 104. Figure 20(I) corresponds to Figure 19(I), and the actuator 104 is in a standby state. Figure 20(II) shows the state when the iron piece 120 of the actuator 104 has reached its maximum operating position, that is, when the movable pin 320 has reached its maximum stroke position, displaced in its axial direction, i.e., in the Y-axis direction. This state can be created by the attractive force of the permanent magnet 320. Figure 20(III) is a diagram illustrating that the iron piece 120 can swing so that the surface to be attracted 120a becomes parallel to the surface to be attracted 130a when the iron piece 120 and the attraction surface 130a overlap each other under the attractive force of the permanent magnet 320. The swinging of the movable pin 320, that is, the tilting of its axis Ax, establishes the parallel state between the surface to be attracted 120a and the attraction surface 130a.

[0082] As mentioned above, the actuator housing 122 surrounding the iron piece 120 is equipped with an actuator communication unit 124 (Figure 3). On the other hand, the switch body 102 is equipped with a sensor-side coil 152 (Figure 9). Based on the strength of the wireless signal received from the actuator communication unit 124 via the sensor-side coil 152, it is determined whether the actuator 104 is within a predetermined range relative to the switch body 102, that is, whether the distance d is below a threshold.

[0083] Figure 21 is a flowchart illustrating the power supply control of the electromagnet 130 by the second MCU 204 during the door PD closing process. When the door PD is open, no power is supplied to the electromagnet 130 (S1). As the door PD closes, that is, during the closing process, the actuator 104 approaches the switch body 102. In step S2, the actuator communication unit 124 and the sensor-side coil 152 determine whether the distance d between the surface to be attracted 120a and the attraction surface 130a is within a predetermined value. If it is determined in step S2 that the distance d is within a predetermined value, the process proceeds to step S3, where it is determined whether the distance d2 is below a threshold. If it is determined in step S3 that the distance d2 is below a threshold, the process proceeds to step S4. In step S4, power is supplied to the electromagnet 130, provided that other conditions are met. When the electromagnet 130 is driven, the actuator 104 is attracted to the electromagnet 130 by the electromagnetic force of the electromagnet 130, and the door PD becomes electromagnetically locked. In this embodiment, in step S1, power is controlled so that no power is supplied to the electromagnet 130, and in step S4, power is supplied to the electromagnet 130. However, any configuration that controls the electromagnet 130 to generate sufficient attractive force to maintain the closed state of the door PD according to the determination result in step S3 is acceptable. For example, in step S1, the electromagnet 130 may be driven to generate an attractive force smaller than the attractive force necessary to maintain the closed state of the door PD, and in step S4, the attractive force may be increased to a degree sufficient to maintain the closed state of the door PD.

[0084] The safety switch 100 and the system including it described above are examples of the present invention, but the present invention is not limited thereto and includes, for example, the modifications described below. Modifications will be described with reference to Figures 22 to 25.

[0085] In the first modified example 410 shown in Figure 22, the actuator l04 is fixed to the door frame 6 with a mounting fixture 412. The mounting fixture 412 has a guide surface Gf that guides the actuator 104 in the forward and backward direction, i.e., in the Y-axis direction. The actuator 104 is guided by the guide surface Gf inside the mounting fixture 412 and is displaceable in the Y-axis direction, allowing it to move forward towards the attraction surface 130a of the electromagnet 130. The actuator 104 is biased in the backward direction away from the electromagnet 130 by an elastic body 414 such as a coil spring. When the electromagnet 130 is powered off, the attractive force of the permanent magnet 120b located in the center of the iron piece 120 causes the actuator 104 to move forward in the Y-axis direction against the biasing force of the elastic body 414, and a state in which it is in close contact with the attraction surface 130a is formed under the attractive force of the permanent magnet 120b.

[0086] Figure 23 shows a second modified example 420. In the second modified example 420, only the electromagnet 130 included in the switch body 102 can move forward in the Y-axis direction towards the permanent magnet 120b of the actuator 104 by the guide surface Gf. The electromagnet 130 is biased in the retraction direction by an elastic body 422 such as a coil spring. When the electromagnet 130 is powered off, the attractive force of the permanent magnet 120b causes the electromagnet 130 to move forward in the Y-axis direction against the biasing force of the elastic body 422, and under the attractive force of the permanent magnet 120b, a state is formed in which the surface to be attracted 120a and the attracting surface 130a are in close contact.

[0087] Figure 24 shows a third modification 430. In the third modification 430, a movable member 432 and an elastic body 434 such as a coil spring are disposed between the switch body 102 and the first bracket 106. The movable member 432 is displaceable in the Y-axis direction by a guide surface Gf. The switch body 102 is fixed to the movable member 432. When the movable member 432 is displaced in the Y-axis direction, the switch body 102 moves with it in the Y-axis direction, allowing it to move forward and approach the iron piece 120 of the actuator 104. The movable member 432 is biased in the retraction direction by an elastic body 442 such as a coil spring. With the electromagnet 130 powered off, the attractive force of the permanent magnet 120b of the iron piece 120 causes the electromagnet 130 to move forward together with the movable member 432 against the biasing force of the elastic body 434, and under the attractive force of the permanent magnet 120b, a state is formed in which the surface to be attracted 120a and the attracting surface 130a are in close contact.

[0088] In the fourth modified example 440 shown in Figure 25, the switch body 102 is movable relative to the first bracket 106. The switch body 102 is guided by the guide surface Gf and is displaceable in the Y-axis direction. The switch body 102 is biased in the retraction direction by an elastic body 442 such as a coil spring. When the electromagnet 130 is powered off, the attractive force of the permanent magnet 120b of the iron piece 120 causes the electromagnet 130 to move forward together with the movable member 432 against the biasing force of the elastic body 442, and a state is formed where the surface to be attracted 120a and the attracting surface 130a are in close contact under the attractive force of the permanent magnet 120b.

[0089] Furthermore, in the above modified examples 1 to 4, the object moving in the Y-axis direction may be held in a swingable manner. For example, in the first modified example 410, the actuator 104 that moves relative to the mounting device 412 may be held in a swingable manner relative to the mounting device 412.

[0090] In the above embodiments and modifications 1 to 4, only the switch body 102, actuator 104, and the member holding the switch body 102 or actuator 104 of the safety switch 100 are held to move in the Y-axis direction, but this is not limited to this. For example, the iron piece 120 may be held to move in the actuator 104 as in the above embodiment, and the electromagnet 130 may be held to move as in modification 2. [Explanation of Symbols]

[0091] 100 Examples of Safety Switches with Electromagnetic Locking Mechanisms 102 Switch console 104 Actuator 120 Actuator iron piece (magnetizing member) 120a Surface of actuator that is attracted 120b permanent magnet 126 Actuator mounting bracket (base component) 126a Through hole 130 Electromagnet 130a Electromagnet's attracting surface 300a Through hole in base member 320 movable pins 322 Sleeves 322a Sleeve one end flange 322b Sleeve other end flange 324 Compression coil spring 326 Cushioning material

Claims

1. A switch body is positioned in the partition fixing part of a partition system that demarcates the operating area in which the device operates, An actuator is installed on a movable part that is movable relative to the fixed part of the section, A safety switch comprising, for detecting that the actuator is within a predetermined range relative to the switch body, The actuator, A magnetized member having an adsorption surface that corresponds to the adsorption surface formed on the electromagnet provided on the switch body, An actuator mounting portion for attaching the actuator to the movable part, The system includes a moving mechanism that movably supports the magnetized member with respect to the actuator mounting portion such that the relative position of the surface of the magnetized member to be attracted with respect to the actuator mounting portion is offset toward the surface of the switch body when the actuator is within a predetermined range with respect to the switch body than when the actuator is not within a predetermined range with respect to the switch body, The actuator is equipped with a permanent magnet, Due to the attractive force of the permanent magnet, the magnetized member moves to a position where its relative position to the surface to be attracted is offset toward the surface to be attracted. The electromagnet is a safety switch that attracts the magnetized member after the attracting surface and the surface to be attracted come into contact.

2. In the safety switch according to claim 1, The actuator comprises an actuator coil corresponding to a detection unit provided on the switch body for detecting that the actuator is within a predetermined range relative to the switch body, A safety switch in which the moving mechanism movably supports the magnetizing member and the actuator coil with respect to the actuator mounting portion such that the relative position of the actuator coil with respect to the actuator mounting portion moves together with the relative position of the surface to be attracted with respect to the actuator mounting portion.

3. In the safety switch according to claim 1, A safety switch in which the permanent magnet is positioned at the center of the surface to be attracted.

4. In the safety switch according to claim 1, Due to the first attractive force of the electromagnet, the magnetized member moves to a position where its relative position to the surface to be attracted is offset toward the attractive surface. A safety switch in which, after the surface to be attracted and the attracting surface come into contact, the electromagnet attracts the magnetized member with a second attracting force stronger than the first attracting force.

5. In the safety switch according to claim 1, The actuator includes a rocking mechanism that rocks the magnetizing member relative to the actuator mounting portion, A safety switch in which, when the surface to be adsorbed is placed on the adsorption surface, the orientation of the surface to be adsorbed is aligned with the orientation of the adsorption surface by the oscillating mechanism.

6. In the safety switch according to claim 1, The moving mechanism is a safety switch that includes a guide portion for guiding the magnetized member toward the electromagnet.

7. In the safety switch according to claim 1, The aforementioned moving mechanism is The through hole provided in the actuator mounting portion, A safety switch comprising a movable pin, to which the magnetizing member is fixed at one end, inserted into the through hole, and movable axially relative to the through hole.

8. In the safety switch according to claim 1, The aforementioned moving mechanism is The through hole provided in the actuator mounting portion, A movable pin is provided, with the magnetizing member fixed to one end, inserted into the through hole, and movable in the axial direction relative to the through hole. The movable pin is inserted into a sleeve that moves in conjunction with the movement of the movable pin, A safety switch in which the movement of the magnetizing member toward the electromagnet is guided by the through-hole and the sleeve.

9. In the safety switch according to claim 1, The aforementioned moving mechanism is The through hole provided in the actuator mounting portion, A movable pin is provided, with the magnetizing member fixed to one end, inserted into the through hole, and movable in the axial direction relative to the through hole. The movable pin is inserted into a sleeve that is loosely fitted into the through hole and moves in conjunction with the movement of the movable pin, The aforementioned movable pin is pivotably supported relative to the actuator mounting portion, and is a safety switch.

10. In the safety switch according to claim 9, The actuator further comprises a biasing member that biases the magnetizing member in a direction that causes it to retract, thus providing a safety switch.

11. In the safety switch according to claim 10, The sleeve has one end flange extending in the radial direction, A safety switch in which the biasing member is positioned between the one-end flange and the actuator mounting portion.

12. In the safety switch according to claim 11, The sleeve has a flange on the opposite side of the flange at one end, A safety switch in which a cushioning member is placed between the other end flange and the actuator mounting portion.

13. In the safety switch according to claim 10, A safety switch in which the biasing member is a compression coil spring.

14. In the safety switch according to claim 13, The aforementioned compression coil spring is composed of a trapezoidal spiral spring in side view, with a diameter that gradually decreases in the axial direction, and becomes flat in side view when compressed, in a safety switch.

15. A switch body is positioned in a fixed partition portion of a partitioning system that defines the operating area in which the device operates, and an actuator is installed in a movable portion that is movable relative to the fixed partition portion. A safety switch comprising a actuator that detects when the actuator is within a predetermined range relative to the switch body, The switch body is provided with an electromagnet having an adsorption surface, A magnetized member provided in the actuator, which is attracted by the electromagnet and has an attracted surface that contacts the attracted surface, The actuator is provided with a moving mechanism that allows the magnetized member to move such that the relative position of the magnetized member to the surface to be attracted is offset toward the surface to be attracted of the switch body when the actuator is within a predetermined range relative to the switch body than when the actuator is not within a predetermined range relative to the switch body. The actuator is equipped with a permanent magnet, Due to the attractive force of the permanent magnet, the magnetized member moves to a position where its relative position to the surface to be attracted is offset toward the surface to be attracted. The electromagnet is a safety switch that attracts the magnetized member after the attracting surface and the surface to be attracted come into contact.

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