JP7820111B2 - Padlock-compatible emergency stop switch and safety control system equipped with same - Google Patents

Description

The present invention relates to a padlock-compatible emergency stop switch and a safety control system equipped with the same, and to improvements to its structure.

Generally, an emergency stop switch has a push button that can be pressed by an operator, and contacts that are made and broken when the push button is pressed (see Figure 1 of JP 2001-35302 A). When the emergency stop switch is pressed, the contacts switch from an ON state to an OFF state, interrupting the device's electrical circuit and bringing the device to an emergency stop.

In order to prevent a third party from inadvertently resetting the push button after it has been pressed, emergency stop switches such as this one equipped with a padlock, as shown in Japanese Patent Application Laid-Open No. 2006-49176, have been proposed, i.e., padlock-compatible emergency stop switches.

As shown in Figures 2 and 8 of JP 2006-49176 A, the padlock-compatible emergency stop switch described therein includes a push button (13) that can be pressed and rotated, a flange (3) disposed around the push button, and a contact portion (2) that is turned ON/OFF by operating the push button (13) (see paragraphs [0025] to [0027] of the same publication). Two through-hole lock holes (13e) are formed on the side of the push button (13) (see paragraph [0033] of the same publication). Meanwhile, four lock holes (31a) are formed in the side plate (31) of the flange (3) (see paragraph [0034] of the same publication). Before the push button (13) is pressed, these through-hole lock holes (13e) and lock holes (31a) do not overlap with each other, as shown in Figure 7 (see paragraph [0035] of the same publication).

Next, when the push button (13) is pressed, the contact portion (2) enters the OFF state. Immediately thereafter, the push button (13) is released from rotation restriction and begins to rotate. At the end of rotation, as shown in FIG. 11, all of the through-hole lock holes (13e) of the push button (13) are aligned with the lock holes (31a) of the flange (3) (see paragraph [0039] of the same publication). From this state, as shown in FIG. 12, the hasp (41) of the padlock (4) is inserted through the lock holes (31a) of the flange (3) into the through-hole lock holes (13e) of the push button (13), and then protrudes through the other lock hole (31a) of the flange (3) to lock, completing the lockout (see paragraph [0040] of the same publication).

In the padlock-compatible emergency stop switch described above, after the through-hole lock hole (13e) of the push button (13) is aligned with the lock hole (31a) of the flange (3), whether or not to lock the through-hole lock hole (13e) and lock hole (31a) by inserting the hasp (41) of the padlock (4) into them is left to the discretion of the operator. Even if operators are given thorough safety training, there is a risk that they may forget to lock the padlock.

Furthermore, with conventional padlock-compatible emergency stop switches, some types require the operator to further operate the push button to align the padlock insertion holes after pressing the push button to initiate an emergency stop. With these types of emergency stop switches, the risk of the push button being inadvertently reset after an emergency stop differs depending on whether the push button is only pressed to initiate an emergency stop or whether the push button is then further operated to align the padlock insertion holes in order to insert a padlock. In the former case, the push button is only pressed, so there is a high risk of the push button being inadvertently reset. However, in the latter case, the push button is further operated after being pressed, so two actions (i.e., two operations) are required to reset the push button, reducing the risk of the push button being inadvertently reset.

The present invention was made in consideration of these conventional circumstances, and the problem that the present invention aims to solve is to improve safety in a padlock-compatible emergency stop switch by preventing the padlock from being forgotten to be engaged. Another object of the present invention is to provide a padlock-compatible emergency stop switch that can improve safety by reducing the risk of the emergency stop state being inadvertently reset. Furthermore, the present invention aims to provide a safety control system that is equipped with such a padlock-compatible emergency stop switch and can monitor whether the padlock is attached.

The padlock-compatible emergency stop switch according to the first aspect of the present invention has at least two insertion holes for inserting padlocks, emergency stop contacts that can be opened by operating a push button, and a detection means that is made up of a circuit different from the emergency stop contacts and detects that the insertion holes are aligned and that a padlock can be inserted . The detection by the detection means is performed by detecting from the position of the push button that, after the emergency stop contacts are turned off by operating the push button, further operation of the push button has transitioned to a state where a padlock can be inserted .

According to the first aspect of the present invention, the detection means, which is a circuit different from the emergency stop contacts, detects that at least two insertion holes for inserting padlocks are aligned and that a padlock can be inserted. At this time, the detection means detects that each insertion hole is aligned and that a padlock can be inserted , so it is possible to monitor whether each insertion hole is aligned, thereby reducing the risk of the emergency stop state being inadvertently reset and improving safety.

The padlock-compatible emergency stop switch according to the second aspect of the present invention comprises a push button having a first insertion hole for inserting a padlock, a housing that slidably supports the push button and has a second insertion hole for inserting the padlock, emergency stop contacts that can be opened by operating the push button, and detection means that consists of a circuit different from the emergency stop contacts and detects that the first and second insertion holes are aligned and a state in which a padlock can be inserted . The detection by the detection means is performed by detecting, from the position of the push button, that the state in which a padlock can be inserted is entered by further operation of the push button after the emergency stop contacts have been turned off by operating the push button.

According to the second aspect of the present invention, when the push button is operated, the first insertion hole for inserting a padlock on the push button side and the second insertion hole for inserting a padlock on the housing side are aligned, and the fact that a padlock can be inserted is detected by a detection means consisting of a circuit different from the emergency stop contact. At this time , the detection means detects that the first and second insertion holes are aligned and a padlock can be inserted, so it is possible to monitor whether the first and second insertion holes are aligned, thereby reducing the risk of the emergency stop state being inadvertently reset and improving safety.

In the present invention, the operation of the push button is a push operation in which the push button is depressed or a turn operation in which the push button is rotated.

The safety control system of the present invention is equipped with the padlock-compatible emergency stop switch described above, and after an emergency stop is initiated by the emergency stop switch, entry into the danger zone in which the machine to be stopped is installed is permitted based on detection by the detection means.

According to the present invention, after an emergency stop, the vehicle is only allowed to enter the danger zone once it has been detected by the detection means, thereby improving safety.

As described above, the present invention can prevent forgetting to lock the padlock and reduce the risk of the emergency stop state being inadvertently reset, thereby improving safety.

1 is a schematic vertical cross-sectional view of a padlock-compatible emergency stop switch according to a first embodiment of the present invention; 3A to 3C are diagrams for explaining the operation procedure of the emergency stop switch (FIG. 1) in chronological order. 3A to 3C are diagrams for explaining the operation procedure of the emergency stop switch (FIG. 1) in chronological order. 3A to 3C are diagrams for explaining the operation procedure of the emergency stop switch (FIG. 1) in chronological order. 10A is a schematic longitudinal sectional view of a padlock-compatible emergency stop switch according to a second embodiment of the present invention, and FIG. 10B is a transverse sectional view taken along line BB thereof. 5A and 5B are diagrams for explaining the operation procedure of the emergency stop switch (FIGS. 5A and 5B) in chronological order. 5A and 5B are diagrams for explaining the operation procedure of the emergency stop switch (FIGS. 5A and 5B) in chronological order. 5A and 5B are diagrams for explaining the operation procedure of the emergency stop switch (FIGS. 5A and 5B) in chronological order. FIG. 10 is a schematic vertical cross-sectional view of a padlock-compatible emergency stop switch according to a third embodiment of the present invention. 10A to 10C are diagrams for explaining the operation procedure of the emergency stop switch (FIG. 9) in chronological order. 10A to 10C are diagrams for explaining the operation procedure of the emergency stop switch (FIG. 9) in chronological order. FIG. 10 is an overall perspective view showing a specific structure of the emergency stop switch (FIG. 9). FIG. 13 is an exploded view of the emergency stop switch (FIG. 12). This shows the state after the padlock is attached to the emergency stop switch (FIG. 12). FIG. 13 is a vertical cross-sectional view of the emergency stop switch (FIG. 12) taken along line XV-XV. FIG. 10 is a schematic vertical cross-sectional view of a padlock-compatible emergency stop switch according to a fourth embodiment of the present invention. 17A to 17C are diagrams for explaining the operation procedure of the emergency stop switch (FIG. 16) in chronological order. 17A to 17C are diagrams for explaining the operation procedure of the emergency stop switch (FIG. 16) in chronological order. 17A to 17C are diagrams for explaining the operation procedure of the emergency stop switch (FIG. 16) in chronological order. 17A to 17C are diagrams for explaining the operation procedure of the emergency stop switch (FIG. 16) in chronological order. FIG. 10 is a schematic vertical cross-sectional view of a padlock-compatible emergency stop switch according to a fifth embodiment of the present invention. FIG. 10 is a schematic vertical cross-sectional view of a padlock-compatible emergency stop switch according to a sixth embodiment of the present invention. 23A to 23C are diagrams for explaining the operation procedure of the emergency stop switch (FIG. 22) in chronological order. 23A to 23C are diagrams for explaining the operation procedure of the emergency stop switch (FIG. 22) in chronological order. FIG. 13 is a schematic vertical cross-sectional view of a padlock-compatible emergency stop switch according to a seventh embodiment of the present invention. 26A to 26C are diagrams for explaining the operation procedure of the emergency stop switch (FIG. 25) in chronological order. 26A to 26C are diagrams for explaining the operation procedure of the emergency stop switch (FIG. 25) in chronological order. FIG. 13 is a schematic vertical cross-sectional view of a padlock-compatible emergency stop switch according to an eighth embodiment of the present invention. 29A to 29C are diagrams for explaining the operation procedure of the emergency stop switch (FIG. 28) in chronological order. 29A to 29C are diagrams for explaining the operation procedure of the emergency stop switch (FIG. 28) in chronological order. FIG. 13 is a schematic vertical cross-sectional view of a padlock-compatible emergency stop switch according to a ninth embodiment of the present invention. FIG. 19 is a schematic vertical cross-sectional view of a padlock-compatible emergency stop switch according to a tenth embodiment of the present invention. 33 is a diagram for explaining the operation procedure of the emergency stop switch (FIG. 32). FIG. FIG. 19 is a schematic vertical cross-sectional view of a padlock-compatible emergency stop switch according to an eleventh embodiment of the present invention. 1 is a schematic block diagram of a safety control system employing a padlock-compatible emergency stop switch according to the present invention.

Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.
[First Example]
1 to 4 are diagrams illustrating a padlock-compatible emergency stop switch according to a first embodiment of the present invention. Fig. 1 shows a schematic vertical cross-sectional configuration of the emergency stop switch, and Figs. 2 to 4 show the operation procedure of the emergency stop switch in Fig. 1 in chronological order. The emergency stop switch is installed, for example, near the boundary (e.g., at an entrance/exit) between a dangerous area where a machine is installed and a safety area outside of it in a factory (the same applies to the second to tenth embodiments below). For ease of explanation, in each figure, the left-right direction of the figure is referred to as the x-direction, the direction perpendicular to the plane of the figure is referred to as the y-direction, and the up-down direction of the figure is referred to as the z-direction. In other words, if the x- and y-directions are horizontal, the z-direction is vertical.

As shown in Figure 1, the padlock-compatible emergency stop switch 1 of this embodiment includes a push button 2 and a case (housing) 3 that slidably supports the push button 2 and houses a portion of it.

The push button 2 has an operating unit 20 with an operating surface 20a on the front side that the operator presses to operate it, and a shaft 21 that is connected to the back side of the operating unit 20 and extends in the x direction (axial direction). The shaft 21 has a single through-hole (first insertion hole) 21a that extends in the z direction and opens onto the outer periphery of the shaft 21. As described below, the through-hole 21a is a hole for inserting a padlock.

The case 3 has a cylindrical portion 30 that supports the shaft portion 21 of the push button 2 so that it can slide in the x direction (axial direction). The cylindrical portion 30 is formed with through holes (second insertion holes) 30a and 30b extending in the z direction. As will be described later, the through holes 30a and 30b are holes for inserting padlocks. The center line 30a- _c of the through hole 30a and the center line 30b- _c of the through hole 30b extend on the same straight line, and the through holes 30a and 30b are positioned opposite each other when viewed from the z direction and are aligned in the z direction. Furthermore, as shown in FIG. 1 , the center lines 30a- _c and 30b _-c are offset, i.e., misaligned, by a predetermined amount in the x direction with respect to the center line 21a- _c of the through hole 21a of the shaft portion 21 of the push button 2 when the push button 2 is in its initial position before being pressed.

In this example, the cylindrical portion 30 has two opposing through holes (i.e., one set) 30a, 30b, but two or more sets (i.e., four or more) of these through holes may be provided. Furthermore, it is sufficient that at least one through hole on the cylindrical portion 30 side can be aligned with the through hole 21a on the push button 2 side (i.e., at least two in the entire emergency stop switch). For example, if through hole 30a is used as the through hole on the cylindrical portion 30 side, a notch having a spatial area larger than the inner diameter of through hole 30b may be provided in the cylindrical portion 30 at a position opposite through hole 30a instead of the other through hole 30b.

The case 3 has a mounting portion 31 for mounting to a panel P of, for example, a machine control panel (not shown). A threaded portion (not shown) is formed on the outer periphery of the mounting portion 31, and the mounting portion 31 is inserted into a mounting hole Pa formed through the panel P and fastened to the panel P by a lock nut (not shown) that screws onto the threaded portion on the outer periphery of the mounting portion 31 from the back side of the panel P.

A circuit C1 having a fixed contact 32 and a circuit (detection means) C2 having a fixed contact 33 are provided inside the mounting portion 31. For ease of illustration, elements other than the fixed contacts 32 and 33 are not shown in the circuits C1 and C2 (the same applies to the second through tenth embodiments described below). Meanwhile, an extension portion 22 extending in the x-direction from the rear surface of the shaft portion 21 of the push button 2 is connected to the rear surface of the shaft portion 21. A movable contact 23 is attached to the tip of the extension portion 22, and the movable contact 23 moves together with the push button 2 via the extension portion 22 and shaft portion 21.

The operating procedure of the emergency stop switch 1 will be described with reference to FIGS. 1 to 4. FIG.
First, before the push button 2 is operated, i.e., before an emergency stop is performed, the operating surface 20a of the operating portion 20 of the push button 2 is located in the initial position (solid line position) as shown in Fig. 1. At this time, the through-hole 21a of the shaft 21 of the push button 2 is not aligned in the z direction with the through-holes 30a, 30b of the cylindrical portion 30 of the case 3, but is offset. Also, the movable contact 23 is in contact with the fixed contact 32 of the circuit C1, and the circuit C1 is in the ON state. Meanwhile, the circuit C2 is in the OFF state. At this time, an operation permission signal is output to the machine in the danger zone, the machine is in operation, and the operator is not permitted to enter the danger zone.

Next, when the operator presses (pushes) the push button 2, the operating surface 20a of the operating section 20 of the push button 2 moves to the emergency stop position (dashed line position) as shown in Figure 2. The push button 2 is temporarily locked in this emergency stop position by a locking mechanism (not shown). At this time, the movable contact 23 moves away from the fixed contact 32 of circuit C1, turning circuit C1 off. Meanwhile, circuit C2 remains off. At this time, the operation permission signal to the machine in the danger zone is turned off, and the machine transitions to an emergency stop state. Furthermore, the through-hole 21a of the shaft 21 of the push button 2 is not aligned in the z direction with the through-holes 30a, 30b in the cylindrical section 30 of the case 3 and is offset, preventing the operator from entering the danger zone.

Next, when the operator further depresses (pushes) the push button 2, the operating surface 20a of the operating portion 20 of the push button 2 moves to the padlock insertion position (the position indicated by the two-dot chain line) as shown in FIG. 3 . The push button 2 is temporarily locked in this padlock insertion position by a locking mechanism (not shown). At this time, the center line 21a- _c of the through hole 21a in the shaft portion 21 of the push button 2 coincides with the center lines 30a _-c and 30b- _c of the through holes 30a and 30b in the cylindrical portion 30 of the case 3, and the through hole 21a is aligned in the z direction with the through holes 30a and 30b. At this time, the movable contact 23 also contacts the fixed contact 33 of the circuit C2, turning the circuit C2 on. This detects that the through holes 21a, 30a, and 30b are aligned in a straight line (i.e., a state in which a padlock can be inserted or is insertable, as described below). Meanwhile, circuit C1 remains in the OFF state. At this time, under the emergency stop state of the machine in the danger zone, circuit C2 detects that each of the through-holes 21a, 30a, 30b is aligned and ready to insert a padlock, thereby permitting the operator to enter the danger zone.

Next, as shown in Figure 4, when the padlock is in the insertable position (Figure 3), the shackle portion 100a of the padlock 100 is inserted into each of the through-holes 21a, 30a, and 30b to lock the lock. At this time, the through-holes 21a, 30a, and 30b are kept aligned in a straight line, so the shackle portion 100a of the padlock 100 can be smoothly inserted into each of the through-holes 21a, 30a, and 30b.

In the padlock insertion position, the push button 2 may not be locked; for example, the push button 2 may be biased toward the emergency stop position by a biasing means (not shown). In this case, the operator presses the push button 2 from the emergency stop position (Figure 2), holds the push button 2 by hand against the biasing force of the biasing means at the padlock insertion position (Figure 3), and aligns the through holes 21a, 30a, and 30b in a straight line, then inserts the shackle portion 100a of the padlock 100 into each of the through holes 21a, 30a, and 30b to lock the device. At this time, the shackle portion 100a of the padlock 100 is inserted into each of the through-holes 21a, 30a, and 30b, maintaining the alignment of the through-holes 21a, 30a, and 30b, so it can be said that circuit C2 detects that the shackle portion 100a of the padlock 100 is inserted. In this case, the two conditions are met: the machine in the hazardous area is in an emergency stop state, and the padlock 100 is attached, and the operator is permitted to enter the hazardous area.

In this way, according to the first embodiment, when the push button 2 is operated (pushed), the through-hole (first insertion hole) 21a for inserting a padlock on the push button 2 side and the through-holes (second insertion holes) 30a, 30b for inserting a padlock on the case 3 side are aligned, and the circuit C2 detects that the shackle portion 100a of the padlock 100 is ready to be inserted or that the shackle portion 100a of the padlock 100 is already inserted.

When circuit C2 detects that the shackle portion 100a of the padlock 100 is inserted into each through-hole 21a, 30a, 30b, it can detect the insertion of the padlock 100 into each through-hole 21a, 30a, 30b, making it possible to monitor whether the padlock 100 is attached, thereby preventing forgetting to lock the padlock 100 and improving safety. Furthermore, when circuit C2 detects that the insertion holes 21a, 30a, 30b are aligned and ready for the padlock 100 to be inserted, i.e., that the padlock 100 can be inserted, it can detect that the insertion holes 21a, 30a, 30b are aligned and ready for the padlock to be inserted, making it possible to monitor the alignment of the insertion holes 21a, 30a, 30b, thereby reducing the risk of the emergency stop state being inadvertently reset and improving safety.

Second Example
Figures 5 to 8 are diagrams illustrating a padlock-compatible emergency stop switch according to a second embodiment of the present invention. Figure 5(a) is a schematic vertical cross-sectional view of the emergency stop switch, Figure 5(b) is a schematic cross-sectional view taken along line B-B, and Figures 6 to 8 show the operating procedure of the emergency stop switch in Figure 5 in chronological order. In each figure, the same reference numerals as those in the first embodiment indicate the same or corresponding parts.

As shown in Figure 5(a), in the padlock-compatible emergency stop switch 1 of this embodiment, the through hole (first insertion hole) 21a for inserting a padlock formed in the shaft portion 21 of the push button 2 is composed of two through holes _21a1 and _21a2 that extend in a direction diagonally intersecting the z direction and are arranged parallel to each other, as shown in Figure 5(b).

5(b), the through holes (second insertion holes) 30a, 30b for inserting padlocks formed in the cylindrical portion 30 of the case 3 are composed of through holes 30a1, 30b1 arranged in a straight line in the z direction and through holes _30a2 , _30b2 similarly arranged in a straight line in the _z direction, and through holes _30a1 , _30b1 and through holes _30a2 , _30b2 are arranged parallel to each other. As shown in FIG. 5(a), in the initial position before the push button ₂ is pressed, each through hole 21a (i.e., _21a1 , _21a2 ) of the shaft portion 21 of the push button 2 is offset, i.e., misaligned, by a predetermined amount in the x direction relative to each through hole 30a, 30b (i.e., each through hole _30a1 , _30b1 , _30a2 , _30b2 ) of the cylindrical portion 30 of the case 3.

As shown in Figure 5(a), the emergency stop switch 1 is provided with a circuit C1 having a fixed contact 32, and as shown in Figure 5(b), it is provided with a circuit C2 having a movable contact 34 that can rotate in conjunction with the rotation of the shaft 21 of the push button 2, and a fixed contact 35 with which the movable contact 34 can come into contact.

The operating procedure of the emergency stop switch 1 will be described with reference to FIGS.
First, before the push button 2 is operated, i.e., before an emergency stop is performed, the operating surface 20a of the operating portion 20 of the push button 2 is located in the initial position (solid line position) as shown in FIG. 5A. At this time, the through-hole 21a (i.e., through-holes _21a1 and _21a2 ) of the shaft portion 21 of the push button 2 is not aligned in the z direction with the through-holes 30a and 30b (i.e., through-holes _30a1 , _30b1 , _30a2 , and _30b2 ) of the cylindrical portion 30 of the case 3, and is offset. Furthermore, the movable contact 23 is in contact with the fixed contact 32 of the circuit C1, and the circuit C1 is in the ON state. Meanwhile, the circuit C2 is in the OFF state (see FIG. 5B). At this time, an operation permission signal is output to the machine in the danger zone, the machine is in operation, and the operator is not permitted to enter the danger zone.

Next, when the operator presses (pushes) the push button 2, the operation surface 20a of the operation unit 20 of the push button 2 moves to the emergency stop position (position indicated by the dashed line) as shown in Figure 6(a). The push button 2 is temporarily locked in this emergency stop position by a locking mechanism (not shown). At this time, the movable contact 23 moves away from the fixed contact 32 of the circuit C1, and the circuit C1 enters the OFF state. Meanwhile, the circuit C2 remains in the OFF state (see Figure 6(b)). At this time, the operation permission signal for the machine in the danger zone is turned OFF, and the machine transitions to the emergency stop state. Furthermore, the center lines of the through holes 21a (i.e., through holes _21a1 , _21a2 ) in the shaft portion 21 of the push button 2 are positioned at the same x-direction position as the respective through holes 30a, 30b (i.e., through holes _30a1 , _30b1 , _30a2 , _30b2 ) in the cylindrical portion 30 of the case 3 (see Figure 1(a)), but are not aligned in the z-direction (see Figure 1(b)), remaining offset and preventing the operator from entering the danger zone.

Next, when the operator rotates (turns) the push button 2, as shown in Figure 7(a), the center line _21ac of the through hole 21a of the shaft 21 of the push button 2 coincides with the center lines 30ac and _30bc of the through holes 30a and _30b of the cylindrical portion 30 of the case 3, and the through hole 21a is aligned in the z direction with the through holes 30a and 30b. More specifically, as shown in Figure 7(b), the through hole _21a1 of the shaft 21 of the push button 2 is aligned in the z direction with the through holes _30a1 and _30b1 of the cylindrical portion 30 of the case 3, and the through hole _21a2 of the shaft 21 of the push button 2 is aligned in the z direction with the through holes _30a2 and _30b2 of the cylindrical portion 30 of the case 3.

When the push button 2 is rotated, the operating surface 20a of the operating portion 20 of the push button 2 is not pressed, so the position of the operating surface 20a in the x direction does not change. However, by rotating the push button 2, the through-hole 21a on the push button 2 aligns with the through-holes 30a and 30b on the case 3, making it possible to insert a padlock. Therefore, for the sake of convenience, the dashed-dotted line position in Figure 7(a) is shown as the padlock insertion position.

In this padlock insertion position, rotation of the push button 2 rotates the movable contact 34 in conjunction with the shaft 21, bringing it into contact with the fixed contact 35, turning on the circuit C2 (see FIG. 7B). This detects that the through-holes 21a, 30a, and 30b are aligned in a straight line (more specifically, the through-hole _21a1 is aligned with the through-holes _30a1 and _30b1 , and the through-hole _21a2 is aligned with the through-holes _30a2 and _30b2 ). This indicates that a padlock can be inserted or is ready to be inserted. Meanwhile, the circuit C1 remains off. In this state, even under an emergency stop condition of the machine in the hazardous area, the circuit C2 detects that the through-holes 21a, 30a, and 30b are aligned and ready for padlock insertion, allowing the operator to enter the hazardous area.

Next, as shown in Figure 8(a), the shackle portion 100a of the padlock 100 is inserted into each of the through holes 21a, 30a, 30b to lock the lock. At this time, the insertion of the shackle portion 100a is not limited to the through holes _21a2 , _30a2 , _30b2 as shown in Figure 8(b), but may also be the through holes _21a1 , _30a1 , _30b1 .

According to the second embodiment, when the push button 2 is operated (turned), the padlock insertion through-hole (first insertion hole) 21a on the push button 2 side and the padlock insertion through-holes (second insertion holes) 30a, 30b on the case 3 side are aligned, and the circuit C2 detects that the shackle portion 100a of the padlock 100 can be inserted, i.e., is in a state where it can be inserted or is insertable. This makes it possible to monitor the alignment of the insertion holes 21a, 30a, 30b, thereby reducing the risk of the emergency stop state being inadvertently reset and improving safety.

In this second embodiment, multiple circuits C2 having a rotatable movable contact 34 and a fixed contact 35 with which the movable contact 34 can come into contact may be provided. Generally, emergency stop switches are designed so that when resetting from an emergency stop state (i.e., restoring the operation permission signal to the machine), the push button is rotated in one direction to return it to its initial position. Therefore, depending on the rotation position of the push button 2, it may become upside down compared to the state shown in the figure (i.e., the movable contact 34 is in a diagonal position, i.e., a point-symmetrical position, to the position shown in the figure). In such cases, providing multiple circuits C2 makes it possible to detect the insertion of a padlock even when the push button 2 is upside down.

[Third Example]
Figures 9 to 15 are diagrams illustrating a padlock-compatible emergency stop switch according to a third embodiment of the present invention. Figure 9 is a schematic vertical cross-sectional view of the emergency stop switch, Figures 10 and 11 are time-series diagrams showing the operating procedures for the emergency stop switch, Figures 12 to 14 are overall perspective views showing the specific structure of the emergency stop switch of Figures 9 to 11, and Figure 15 is a vertical cross-sectional view taken along line XV-XV in Figure 12. In each figure, the same reference numerals as those in the first and second embodiments indicate the same or corresponding parts.

As shown in Figures 9, 12, 13, and 15, the emergency stop switch 1 of this third embodiment includes, in addition to the push button 2 and case 3, a roughly ring-shaped housing portion 5 arranged on the outer periphery of the cylindrical portion 30 of the case 3, and a ring-shaped detection portion (detection portion) 6 (only a portion of which is shown in Figure 9) supported on the housing portion 5 so that it can slide axially (in the x direction). The detection portion 6 is capable of adopting a retracted position in which it is retracted within the housing portion 5, and an extended position in which it extends and protrudes from the housing portion 5. A compression spring (not shown) may be arranged inside the housing portion 5 so that the detection portion 6 is constantly biased in the protruding direction.

As shown in FIG. 9, the housing 5 is provided with a circuit (detection means) C2 having a fixed contact 51. An extension 60 extending in the x direction from the rear surface of the detection unit 6 is connected to the rear surface of the detection unit 6. A movable contact 61 that can abut against the fixed contact 51 is attached to the tip of the extension 60, and the movable contact 61 moves with the push button 2 via the extension 60 and the detection unit 6. Meanwhile, as shown in FIG. 15, the housing 5 incorporates a microswitch 50. The microswitch 50 has an actuator 50a that can abut against the ring-shaped detection unit 6. When the ring-shaped detection unit 6 moves in the axial direction (x direction), the ring-shaped detection unit 6 abuts against the actuator 50a, exerting a pressing force, thereby turning on the internal contacts of the microswitch 50. The movable contact 61 and fixed contact 51 in FIG. 9 correspond to the internal contacts of the microswitch 50 in FIG. 15. While Figure 9 shows the contacts located on the upper side of the cylindrical portion 30, Figure 15 shows the microswitch 50 with the contacts located on the lower side of the cylindrical portion 30. As shown in Figure 9, the cylindrical portion 30 is attached to the panel P via a base portion 5A located at the axial end of the housing portion 5. Therefore, the housing portion 5 and the detection portion 6 are integral with the push button 2 and case 3 via the base portion 5A. Note that Figures 12 to 15 show a contact portion (contact block portion) C that incorporates the contacts of the emergency stop switch 1.

The operating procedure of the emergency stop switch 1 will be described with reference to FIGS.
First, before the push button 2 is operated, i.e., before an emergency stop is initiated, the operation surface 20a of the operation unit 20 of the push button 2 is located in the initial position (solid line position) as shown in FIG. 9 . At this time, the through-hole 21a of the shaft 21 of the push button 2 is not aligned in the z direction with the through-holes 30a, 30b of the cylindrical portion 30 of the case 3, but is offset. The movable contact 23 is in contact with the fixed contact 32 of the circuit C1, and the circuit C1 is in the ON state. Meanwhile, the circuit C2 is in the OFF state. At this time, the detection unit 6 is located in a shielding position, covering and shielding the through-holes 30a, 30b of the cylindrical portion 30 of the case 3 from the outer periphery (FIG. 9 shows only one of the through-holes 30a shielded). At this time, an operation permission signal is output to the machine in the danger zone, and the machine is in operation, prohibiting the operator from entering the danger zone.

Next, when the operator presses (pushes) the push button 2, the operating surface 20a of the operating section 20 of the push button 2 moves to the emergency stop position (dashed line position) as shown in Figure 10. The push button 2 is temporarily locked in this emergency stop position by a locking mechanism (not shown). At this time, the movable contact 23 moves away from the fixed contact 32 of circuit C1, turning circuit C1 off. Meanwhile, circuit C2 remains off. At this time, the operation permission signal to the machine in the danger zone is turned off, and the machine transitions to an emergency stop state. Also, at this time, the through-hole 21a of the shaft 21 of the push button 2 is aligned in the z direction with the through-holes 30a, 30b in the cylindrical section 30 of the case 3, but the detection unit 6 is still positioned in a shielding position that shields the through-holes 30a, 30b.

Next, as shown in FIG. 11, the operator presses the pressing surface 6a on the front side of the detector 6 with the shackle portion 100a of the padlock 100, moving the detector 6 to the open position where it opens the through-hole 30a of the cylindrical portion 30 of the case 3 without blocking it. From this state, the shackle portion 100a of the padlock 100 is inserted into the through-hole 30a, the through-hole 21a of the shaft portion 21 of the push button 2, and the through-hole 30b of the cylindrical portion 30 to lock the lock. At this time, the detector 6 is retracted within the housing portion 5 (see FIG. 14). As a result, the movable contact 61, which moves in conjunction with the detector 6, comes into contact with the fixed contact 51 of circuit C2, turning circuit C2 on. This detects that the shackle portion 100a of the padlock 100 has been inserted into each of the through-holes 21a, 30a, and 30b. In this case, the operator is permitted to enter the danger zone when two conditions are met: the machine in the danger zone is in an emergency stop state, and the padlock 100 is installed.

According to the third embodiment, when the push button 2 is operated (pushed), the padlock insertion through-hole (first insertion hole) 21a on the push button 2 is aligned with the padlock insertion through-holes (second insertion holes) 30a, 30b on the case 3, and it is possible to detect that the shackle portion 100a of the padlock 100 has been inserted into each of the through-holes 21a, 30a, 30b. This makes it possible to monitor whether the padlock 100 is attached, thereby preventing forgetting to lock the padlock 100 and improving safety. Note that in this third embodiment, the ring-shaped detector 6 may be divided circumferentially into multiple detectors 6, and each of the multiple detectors 6 may be provided with a microswitch 50 (Figure 15) to accommodate multiple padlocks.

[Fourth Example]
16 to 20 are diagrams illustrating a padlock-compatible emergency stop switch according to a fourth embodiment of the present invention. Fig. 16 is a schematic vertical cross-sectional view of the emergency stop switch, and Figs. 17 to 20 are diagrams showing the operation procedure of the emergency stop switch in chronological order. In each figure, the same reference numerals as those in the first to third embodiments indicate the same or corresponding parts.

In the third embodiment, the ring-shaped detector 6 is supported on the housing 5 so as to slide axially (in the x direction). However, in the emergency stop switch 1 of this fourth embodiment, the ring-shaped detector 6 has a stay 6A extending in the z direction, and the upper end of the stay 6A is rotatably attached to the housing 5 via a hinge 6p. This allows the detector 6 to be supported on the housing 5 so as to be able to swing freely. The detector 6 can be positioned in a retracted position retracted within the housing 5 and in an extended position extending from the housing 5. A compression spring (not shown) may be provided within the housing 5 so that the detector 6 is constantly biased toward the protruding side. The front side of the detector 6 is formed with a pressing surface 6a and an inclined surface 6b, which is located above (i.e., radially inward) the pressing surface 6a and extends at an angle relative to the pressing surface 6a.

The operating procedure of the emergency stop switch 1 will be described with reference to FIGS.
First, before the push button 2 is operated, i.e., before an emergency stop is performed, the operation surface 20a of the operation unit 20 of the push button 2 is located in the initial position (solid line position) as shown in FIG. 16 . At this time, the through-hole 21a of the shaft 21 of the push button 2 is not aligned in the z direction with the through-holes 30a, 30b of the cylindrical portion 30 of the case 3, but is offset. The movable contact 23 is in contact with the fixed contact 32 of the circuit C1, and the circuit C1 is in the ON state. Meanwhile, the circuit C2 is in the OFF state. At this time, the detection unit 6 is located in a shielding position, covering and shielding the through-hole 30b of the cylindrical portion 30 of the case 3 from its outer periphery. Furthermore, an operation permission signal is output to the machine in the danger zone, and the machine is in operation, prohibiting the operator from entering the danger zone.

Next, when the operator presses (pushes) the push button 2, the operating surface 20a of the operating section 20 of the push button 2 moves to the emergency stop position (dashed line position) as shown in Figure 17. The push button 2 is temporarily locked in this emergency stop position by a locking mechanism (not shown). At this time, the movable contact 23 moves away from the fixed contact 32 of circuit C1, turning circuit C1 off. Meanwhile, circuit C2 remains off. At this time, the operation permission signal to the machine in the danger zone is turned off, and the machine transitions to an emergency stop state. Also, at this time, the through-hole 21a of the shaft 21 of the push button 2 is aligned in the z direction with the respective through-holes 30a and 30b in the cylindrical section 30 of the case 3, but the detection unit 6 is still positioned in a shielding position that shields through-hole 30b.

Next, as shown in Figure 18, the operator inserts the shackle portion 100a of the padlock 100 into the through-hole 30a of the cylindrical portion 30 of the case 3. At this time, the tip of the shackle portion 100a passes through the through-hole 30b of the cylindrical portion 30 of the case 3 and abuts against the inclined surface 6b on the front side of the detection unit 6, exerting a pressing force on the inclined surface 6b. As a result, the detection unit 6 swings around the hinge 6p via the stay 6A, causing the detection unit 6 to retract into the housing portion 5 and move to the retracted position, as shown in Figure 19. At this time, the shackle portion 100a abuts against the pressing surface 6a of the detection unit 6. From this state, the padlock 100 is locked, as shown in Figure 20.

In the state shown in Figure 19, the movable contact 61, which moves in conjunction with the detector 6, comes into contact with the fixed contact 51 of circuit C2, turning circuit C2 on. This detects that the shackle portion 100a of the padlock 100 has been inserted into each of the through-holes 21a, 30a, and 30b. In this case, the operator is permitted to enter the danger zone because the two conditions are met: the machine in the danger zone is in an emergency stop state, and the padlock 100 is installed.

According to the fourth embodiment, when the push button 2 is operated (pushed), the padlock insertion through-hole (first insertion hole) 21a on the push button 2 side is aligned with the padlock insertion through-holes (second insertion holes) 30a, 30b on the case 3 side, and it is possible to detect that the shackle portion 100a of the padlock 100 has been inserted into each of the through-holes 21a, 30a, 30b. This makes it possible to monitor whether the padlock 100 is attached, thereby preventing forgetting to lock the padlock 100 and improving safety. Furthermore, in this fourth embodiment, the ring-shaped detection portion 6 is supported so that it can swing freely, allowing the ring-shaped detection portion 6 to be reliably pressed even when the padlock is tilted.

Fifth Example
21 is a diagram for explaining a padlock-compatible emergency stop switch according to a fifth embodiment of the present invention, showing a schematic vertical cross-sectional configuration of the emergency stop switch. In the figure, the same reference numerals as those in the third embodiment indicate the same or corresponding parts.

In the third embodiment, the cylindrical portion 30 of the case 3 is attached to the panel P via the base portion 5A of the housing portion 5 (see Figure 9), thereby providing an example in which the housing portion 5 and the detection portion 6 are integral with the push button 2 and case 3. However, in this fifth embodiment, as shown in Figure 21, the housing portion 5 does not have a base portion extending toward the cylindrical portion 30 of the case 3, and the housing portion 5 and the detection portion 6 are not integral with the push button 2 and case 3; in other words, they are provided as separate components.

The effects of the fifth embodiment are the same as those of the third embodiment. When the push button 2 is operated (pushed), the padlock insertion through-hole (first insertion hole) 21a on the push button 2 side is aligned with the padlock insertion through-holes (second insertion holes) 30a, 30b on the case 3 side. This allows the insertion of the shackle portion 100a of the padlock 100 into each of the through-holes 21a, 30a, 30b to be detected. This makes it possible to monitor whether the padlock 100 is installed, thereby preventing the padlock 100 from being forgotten to be locked and improving safety. Furthermore, the housing portion 5 can be retrofitted near an already installed emergency stop switch, allowing the insertion of a padlock to be detected without modifying the installed emergency stop switch.

Sixth Example
22 to 24 are diagrams illustrating a padlock-compatible emergency stop switch according to a sixth embodiment of the present invention. Fig. 22 is a schematic vertical cross-sectional view of the emergency stop switch, and Figs. 23 and 24 are diagrams showing the operation procedure of the emergency stop switch in chronological order. In each figure, the same reference numerals as those in the first to fifth embodiments indicate the same or corresponding parts.

In the emergency stop switch 1 according to the sixth embodiment, the circuit C2 has a proximity sensor 24 provided inside the shaft 21 of the push button 2. The proximity sensor 24 is used to detect when the metal shackle of a padlock is inserted into the through-hole 21a of the shaft 21, and is configured, for example, as an inductive proximity sensor or a capacitive proximity sensor. A transmissive or reflective photoelectric sensor may also be used in place of the proximity sensor 24. Figures 22 to 24 show a simplified version of the proximity sensor 24.

The operating procedure of the emergency stop switch 1 will be described with reference to FIGS. 22 to 24. FIG.
First, before the push button 2 is operated, i.e., before an emergency stop is performed, the operating surface 20a of the operating portion 20 of the push button 2 is located in the initial position (solid line position) as shown in Figure 22. At this time, the through-hole 21a of the shaft 21 of the push button 2 is not aligned in the z direction with the through-holes 30a, 30b of the cylindrical portion 30 of the case 3, but is offset. Also, the movable contact 23 is in contact with the fixed contact 32 of the circuit C1, and the circuit C1 is in the ON state. Meanwhile, the circuit C2 is in the OFF state. At this time, an operation permission signal is output to the machine in the danger zone, the machine is in operation, and the operator is not permitted to enter the danger zone.

Next, when the operator presses (pushes) the push button 2, the operating surface 20a of the operating section 20 of the push button 2 moves to the emergency stop position (dashed line position) as shown in Figure 23. The push button 2 is temporarily locked in this emergency stop position by a locking mechanism (not shown). At this time, the movable contact 23 moves away from the fixed contact 32 of circuit C1, and circuit C1 enters the OFF state. Meanwhile, circuit C2 remains in the OFF state. At this time, the operation permission signal to the machine in the danger zone is turned OFF, and the machine transitions to an emergency stop state. Also, at this time, the through-hole 21a of the shaft 21 of the push button 2 is aligned in the z direction with the respective through-holes 30a and 30b in the cylindrical section 30 of the case 3.

Next, as shown in Figure 24, the operator inserts the shackle portion 100a of the padlock 100 into each of the through-holes 21a, 30a, and 30b to lock the door. At this time, the proximity sensor 24 detects the shackle portion 100a of the padlock 100 and turns on, turning on circuit C2. This satisfies two conditions: the machine in the danger zone is in an emergency stop state, and the padlock 100 is attached. This allows the operator to enter the danger zone.

According to the sixth embodiment, when the push button 2 is operated (pushed), the through-hole (first insertion hole) 21a for inserting the padlock on the push button 2 is aligned with the through-holes (second insertion holes) 30a, 30b for inserting the padlock on the case 3, and it is possible to detect that the shackle portion 100a of the padlock 100 has been inserted into each of the through-holes 21a, 30a, 30b. This makes it possible to monitor whether the padlock 100 is attached, thereby preventing forgetting to lock the padlock 100 and improving safety.

[Seventh Example]
Figures 25 to 27 are diagrams for explaining a padlock-compatible emergency stop switch according to a seventh embodiment of the present invention. Figure 25 is a schematic vertical cross-sectional view of the emergency stop switch, and Figures 26 and 27 are diagrams showing the operation procedure of the emergency stop switch in chronological order. In each figure, the same reference numerals as those in the first to sixth embodiments indicate the same or corresponding parts.

The emergency stop switch 1 of this seventh embodiment differs from the sixth embodiment in that a microswitch 25 is provided instead of the proximity sensor 24 of the sixth embodiment. The microswitch 25 has a contact 25a in a recess 21b that communicates with the through-hole 21a of the shaft 21 of the push button 2, and the contact 25a is provided so that it can be inserted and removed from the through-hole 21a. The microswitch 25 is connected to the contact 25a.

The operating procedure of the emergency stop switch 1 will be described with reference to FIGS. 25 to 27. FIG.
First, before the push button 2 is operated, i.e., before an emergency stop is performed, the operating surface 20a of the operating unit 20 of the push button 2 is located in the initial position (solid line position) as shown in Figure 25. At this time, the through-hole 21a of the shaft 21 of the push button 2 is not aligned in the z direction with the through-holes 30a, 30b of the cylindrical portion 30 of the case 3, but is offset. The movable contact 23 is in contact with the fixed contact 32 of the circuit C1, and the circuit C1 is in the ON state. Meanwhile, the contactor 25a protrudes into the through-hole 21a of the shaft 21 of the push button 2, the microswitch 25 is in the OFF state, and the circuit C2 is in the OFF state. At this time, an operation permission signal is output to the machinery in the hazardous area, the machinery is in operation, and the operator is not permitted to enter the hazardous area.

Next, when the operator presses (pushes) the push button 2, the operating surface 20a of the operating section 20 of the push button 2 moves to the emergency stop position (dashed line position) as shown in Figure 26. The push button 2 is temporarily locked in this emergency stop position by a locking mechanism (not shown). At this time, the movable contact 23 moves away from the fixed contact 32 of circuit C1, and circuit C1 enters the OFF state. Meanwhile, circuit C2 remains in the OFF state. At this time, the operation permission signal to the machine in the danger zone is turned OFF, and the machine transitions to an emergency stop state. Also, at this time, the through-hole 21a of the shaft 21 of the push button 2 is aligned in the z direction with the respective through-holes 30a and 30b in the cylindrical section 30 of the case 3.

Next, as shown in Figure 27, the operator inserts the shackle portion 100a of the padlock 100 into each of the through-holes 21a, 30a, and 30b to lock the door. When the shackle portion 100a is inserted into the through-hole 21a, the shackle portion 100a causes the contact 25a of the microswitch 25 to sink into the recess 25b. This turns on the switch 25, and circuit C2 enters the on state. This satisfies two conditions: the machine in the hazardous area is in an emergency stop state, and the padlock 100 is installed. This allows the operator to enter the hazardous area.

According to the seventh embodiment, when the push button 2 is operated (pushed), the through-hole (first insertion hole) 21a for inserting the padlock on the push button 2 is aligned with the through-holes (second insertion holes) 30a, 30b for inserting the padlock on the case 3, and it can be detected that the shackle portion 100a of the padlock 100 has been inserted into each of the through-holes 21a, 30a, 30b. This makes it possible to monitor whether the padlock 100 is attached, thereby preventing forgetting to lock the padlock 100 and improving safety.

Eighth Example
Figures 28 to 30 are diagrams for explaining a padlock-compatible emergency stop switch according to an eighth embodiment of the present invention. Figure 28 is a schematic vertical cross-sectional view of the emergency stop switch, and Figures 29 and 30 are diagrams showing the operation procedure of the emergency stop switch in chronological order. In each figure, the same reference numerals as those in the first to seventh embodiments indicate the same or corresponding parts.

In the emergency stop switch 1 according to the eighth embodiment, the circuit C2 includes a proximity sensor 52 installed inside the housing 5. The proximity sensor 52 detects the padlock body (i.e., the key mechanism) when the shackle of the padlock is inserted into each of the through-holes 21a, 30a, and 30b, and is configured, for example, as an inductive proximity sensor or a capacitive proximity sensor. Figures 28 through 30 show a simplified version of the proximity sensor 52. Note that a transmissive or reflective photoelectric sensor may be used instead of the proximity sensor 52, or a combination of an RFID (Radio Frequency Identification) tag and an antenna for detecting it may also be used. Furthermore, the proximity sensor 52 may detect both the key mechanism and the shackle, or may only detect the shackle. For example, the proximity sensor 52 may be built into the push button 2 to detect the insertion of the shackle into each of the through-holes 21a, 30a, and 30b. In this eighth embodiment, the cylindrical portion 30 of the case 3 is attached to the panel P via the base portion 5A of the housing portion 5, so that the housing portion 5 and proximity sensor 52 are integral with the push button 2 and case 3.

The operating procedure of the emergency stop switch 1 will be described with reference to FIGS. 28 to 30. FIG.
First, before the push button 2 is operated, i.e., before an emergency stop is performed, the operating surface 20a of the operating portion 20 of the push button 2 is located in the initial position (solid line position) as shown in Figure 28. At this time, the through-hole 21a of the shaft 21 of the push button 2 is not aligned in the z direction with the through-holes 30a, 30b of the cylindrical portion 30 of the case 3, but is offset. Also, the movable contact 23 is in contact with the fixed contact 32 of the circuit C1, and the circuit C1 is in the ON state. Meanwhile, the circuit C2 is in the OFF state. At this time, an operation permission signal is output to the machine in the danger zone, the machine is in operation, and the operator is not permitted to enter the danger zone.

Next, when the operator presses (pushes) the push button 2, the operating surface 20a of the operating section 20 of the push button 2 moves to the emergency stop position (dashed line position) as shown in Figure 29. The push button 2 is temporarily locked in this emergency stop position by a locking mechanism (not shown). At this time, the movable contact 23 moves away from the fixed contact 32 of circuit C1, and circuit C1 enters the OFF state. Meanwhile, circuit C2 remains in the OFF state. At this time, the operation permission signal to the machine in the danger zone is turned OFF, and the machine transitions to an emergency stop state. Also, at this time, the through-hole 21a of the shaft 21 of the push button 2 is aligned in the z direction with the respective through-holes 30a and 30b in the cylindrical section 30 of the case 3.

Next, as shown in Figure 30, the operator inserts the shackle portion 100a of the padlock 100 into each of the through-holes 21a, 30a, and 30b to lock the door. At this time, the proximity sensor 52 detects the main body 100A of the padlock 100 and turns on, turning on circuit C2. This satisfies two conditions: the machine in the danger zone is in an emergency stop state, and the padlock 100 is attached. This allows the operator to enter the danger zone.

According to the eighth embodiment, when the push button 2 is operated (pushed), the padlock insertion through-hole (first insertion hole) 21a on the push button 2 side is aligned with the padlock insertion through-holes (second insertion holes) 30a, 30b on the case 3 side, and the shackle portion 100a of the padlock 100 is inserted into each through-hole 21a, 30a, 30b, and it can be detected that the padlock 100 has been attached.This makes it possible to monitor whether the padlock 100 is attached, thereby preventing forgetting to lock the padlock 100 and improving safety.

Ninth Example
31 is a diagram for explaining a padlock-compatible emergency stop switch according to a ninth embodiment of the present invention, showing a schematic vertical cross-sectional configuration of the emergency stop switch. In the figure, the same reference numerals as those in the eighth embodiment indicate the same or corresponding parts.

In the eighth embodiment, the cylindrical portion 30 of the case 3 is attached to the panel P via the base portion 5A of the housing portion 5 (see Figure 28), thereby providing an example in which the housing portion 5 and proximity sensor 52 are integral with the push button 2 and case 3. However, in this ninth embodiment, as shown in Figure 31, the housing portion 5 does not have a base portion extending toward the cylindrical portion 30 of the case 3, and the housing portion 5 and proximity sensor 52 are not integral with the push button 2 and case 3; in other words, they are provided as separate components.

The effects of this ninth embodiment are the same as those of the eighth embodiment. When the push button 2 is operated (pushed), the padlock insertion through-hole (first insertion hole) 21a on the push button 2 side is aligned with the padlock insertion through-holes (second insertion holes) 30a, 30b on the case 3 side. When the shackle portion 100a of the padlock 100 is inserted into each through-hole 21a, 30a, 30b, the padlock body 100A can be detected. This makes it possible to monitor whether the padlock 100 is installed, thereby preventing the padlock 100 from being forgotten to be locked and improving safety. Furthermore, the housing portion 5 can be retrofitted near an already installed emergency stop switch, allowing the insertion of a padlock to be detected without modifying the installed emergency stop switch.

[Tenth Example]
32 and 33 are diagrams for explaining a padlock-compatible emergency stop switch according to a tenth embodiment of the present invention. Fig. 32 is a schematic vertical cross-sectional view of the emergency stop switch, and Fig. 33 is a diagram showing the operating procedure for the emergency stop switch. In each figure, the same reference numerals as those in the first to ninth embodiments indicate the same or corresponding parts.

As shown in Figure 32, the emergency stop switch 1 according to the tenth embodiment has a detection unit 6' supported on the housing unit 5 so that it can slide freely in the x direction. A movable contact 61 is attached to the back side of the detection unit 6', and the movable contact 61 is arranged to be able to abut against a fixed contact 51 of circuit C2. The cylindrical portion 30 of the case 3 is attached to the panel P via the base portion 5A of the housing unit 5, and the housing unit 5 and detection unit 6' are integral with the push button 2 and case 3.

The emergency stop switch 1 has a cover 7 for covering the push button 2. The cover 7 is supported on the cover body 8 via a hinge portion 70 so that it can be opened and closed. Note that the hinge portion 70 does not necessarily have to be provided, and the cover 7 may be detachably attached to the cover body 8. The cover 7 is provided with a bracket portion 7A having a through hole (third insertion hole) 7a for inserting a padlock. Meanwhile, the cover body 8 is provided with a bracket portion 8A having a through hole (fourth insertion hole) 8a for inserting a padlock. Each of the through holes 7a, 8a extends in the y direction. At least a portion of the through hole 8a is covered and shielded by the detection unit 6'.

The operating procedure of the emergency stop switch 1 will be described with reference to FIGS. 32 and 33. FIG.
First, before the push button 2 is operated, i.e., before an emergency stop is performed, the operation surface 20a of the operation unit 20 of the push button 2 is located in the initial position (solid line position) as shown in Figure 32. At this time, the movable contact 23 is in contact with the fixed contact 32 of the circuit C1, and the circuit C1 is in the ON state. Meanwhile, the circuit C2 is in the OFF state. The detection unit 6' is located in a shielding position where it covers at least a portion of the through-hole 8a of the bracket portion 8A. Also, at this time, an operation permission signal is output to the machine in the danger zone, the machine is in operation, and the operator is not permitted to enter the danger zone.

Next, when the operator presses (pushes) the push button 2, the operating surface 20a of the operating section 20 of the push button 2 moves to the emergency stop position (dashed line position) as shown in Figure 33 (at this point, the cover 7 has not yet been closed). The push button 2 is temporarily locked in this emergency stop position by a locking mechanism (not shown). At this time, the movable contact 23 moves away from the fixed contact 32 of circuit C1, turning circuit C1 off. As a result, the operation permission signal for the machine in the danger zone is turned off, and the machine transitions to an emergency stop state.

When the operator closes the cover 7 from this state, the bracket portion 7A of the cover 7 presses the pressing surface 6'a on the front side of the detection unit 6' during the closing operation of the cover 7. As shown in Figure 33, the detection unit 6' is retracted into the housing portion 5, moving it to an open position that opens the through-hole 8a, aligning the through-hole 7a of the cover 7 with the through-hole 8a of the cover body 8. At this time, the movable contact 61 comes into contact with the fixed contact 51, turning on circuit C2. This aligns the insertion holes 7a, 8a, detecting that a padlock is inserted or can be inserted, i.e., that the padlock is insertable. From this state, the shackle portion 100a of the padlock 100 is inserted into the through-holes 7a, 8a to lock the lock.

In this case, the operator is permitted to enter the danger zone when two conditions are met: the machine in the danger zone is in an emergency stop state, and the padlock 100 is ready to be inserted.

As described above, according to the tenth embodiment, when the cover 7 is closed, the padlock insertion through-hole (third insertion hole) 7a on the cover 7 side and the padlock insertion through-hole (fourth insertion hole) 8a on the cover body 8 side are aligned, and it can be detected that the shackle portion 100a of the padlock 100 is ready to be inserted. This makes it possible to monitor whether the insertion holes 7a, 8a are aligned, thereby reducing the risk of the emergency stop state being inadvertently reset and improving safety.

[Eleventh Example]
34 is a diagram for explaining a padlock-compatible emergency stop switch according to an eleventh embodiment of the present invention, showing an emergency stop switch with a cover similar to that of the tenth embodiment. In the figure, the same reference numerals as those of the first to tenth embodiments indicate the same or corresponding parts.

In the tenth embodiment, the push button 2 was maintained in the emergency stop position when the cover 7 was closed. However, in the emergency stop switch 1 of the eleventh embodiment, when the cover 7 is closed from a state in which the push button 2 is positioned in the emergency stop position (dashed line position), the cover 7 presses against the operating surface 20a of the operating portion 20 of the push button 2, moving the operating surface 20a to the padlock insertion position (dashed line position), and as a result, the through-hole 7a of the cover 7 is aligned with the through-hole 8a of the cover body 8.

At this time, the movable contact 23 comes into contact with the fixed contact 33 of circuit C2, turning circuit C2 on. This detects that the through holes 7a, 8a are aligned and a padlock can or may be inserted, i.e., a padlock can be inserted. Meanwhile, circuit C1 is in the off state. At this time, when the machine in the hazardous area is in an emergency stop state, circuit C2 detects that the through holes 7a, 8a are aligned and a padlock can be inserted, allowing entry into the hazardous area. Once the through holes 7a, 8a are aligned, the shackle portion 100a of the padlock 100 is inserted into each through hole 7a, 8a, and locking is performed.

[Safety Control System]
FIG. 35 shows an example of a safety control system including the above-described padlock-compatible emergency stop switch 1. As shown in the figure, the safety control system 200 includes a controller 201. An emergency stop signal from circuit C1 of the emergency stop switch 1 and a detection signal from circuit C2 of the emergency stop switch 1 are input to the input side of the controller 201. An AND circuit is provided inside the controller 201, and only when both the emergency stop signal and the detection signal are input does the output side of the controller 201 output a signal permitting entry into the dangerous area. This entry permit signal unlocks, for example, an interlock (safety switch) at an entrance/exit, allowing an operator to enter the dangerous area. In this way, this safety control system makes it possible to monitor whether the padlock insertion through-holes are aligned or whether a padlock 100 is attached to the emergency stop switch 1.

[Other Modifications]
The above-described embodiments should be considered in all respects as merely illustrative of the present invention, and not restrictive. Those skilled in the art will be able to devise various modifications and other embodiments incorporating the principles of the present invention without departing from the spirit and essential characteristics of the present invention, even if not explicitly described herein, in light of the above teachings. For example, while the above-described embodiments illustrate examples in which circuit C2 is configured with normally open contacts, it may instead be configured with normally closed contacts. Furthermore, the microswitch may be any other switch as long as it has a contact for detection.

[Other application examples]
In the above-described embodiment and each of the above-described modified examples, the field of manufacturing (i.e., factory automation (FA)) has been used as an example to explain the field to which the present invention is applicable, but the application of the present invention is not limited to this, and the present invention can also be applied to the fields of construction, civil engineering, catering, and food industries, as well as medical care and distribution.

The present invention is useful for padlock-compatible emergency stop switches and safety control systems equipped with such switches.

1: Padlock compatible emergency stop switch

2: Push button 21a: Through hole (first insertion hole)

3: Case (housing)
30a, 30b: through holes (second insertion holes)

6: Ring-shaped detector (detector)
6': Detection unit

7: Cover 7a: Through hole (third insertion hole)

8: Cover body 8a: Through hole (fourth insertion hole)

100: Padlock 100a: Shackle part

200: Safety control system

C2: Circuit (detection means)

Japanese Patent Application Laid-Open No. 2001-35302 (see FIG. 1) Japanese Patent Application Laid-Open No. 2006-49176 (see paragraphs [0025] to [0027], [0033] to [0035], [0039], and [0040] and Figures 2, 7, 8, 11, and 12)

Claims (4)

In padlock compatible emergency stop switches,
having at least two insertion holes for inserting padlocks;
It has an emergency stop contact that can be opened by operating a push button,
a detection means for detecting whether the insertion holes are aligned and the padlock can be inserted, the detection means being a separate circuit from the emergency stop contact;
The detection by the detection means
After the emergency stop contact is turned off by operating the push button, the padlock is moved to a state where it can be inserted by further operating the push button, and this is detected from the position of the push button.
A padlock compatible emergency stop switch. In padlock compatible emergency stop switches,
a push button having a first insertion hole for inserting a padlock;
a housing that slidably supports the push button and has a second insertion hole for inserting a padlock;
an emergency stop contact that can be opened by operating the push button;
a detection means for detecting whether the first and second insertion holes are aligned and a padlock can be inserted, the detection means being a separate circuit from the emergency stop contact;
The detection by the detection means
After the emergency stop contact is turned off by operating the push button, the padlock is moved to a state where it can be inserted by further operating the push button, and this is detected from the position of the push button.
A padlock compatible emergency stop switch. In claim 1 or 2,
The operation of the push button is a push operation of pressing the push button or a turn operation of rotating the push button.
A padlock compatible emergency stop switch. A padlock-compatible emergency stop switch according to any one of claims 1 to 3 is provided,
After an emergency stop is performed by the emergency stop switch, entry into the danger zone in which the machine to be stopped is installed is permitted based on the detection by the detection means.
A safety control system characterized by: