JP2017199473A - Plug structure and leakage detection circuit breaker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to easily distinguish a state of a grounding plug in a plug having a pole number switching function.SOLUTION: In a plug 10, when the grounding plug 27 protrudes, a switching plate 27b of the grounding plug 27 and a locking plate 45 prevent a movement of the grounding plug 27 to an accommodated position. Further, a pole number display section 22 is provided for displaying in different display modes when the grounding plug 27 is in the restricted state by the locking plate 45 and when it is in the restriction released state by the locking plate 45.SELECTED DRAWING: Figure 10

Description

  The present invention relates to a plug structure having a pole number switching function configured to be able to switch the number of poles according to the form of an outlet, and a leakage detection breaker.

  In recent years, three-pole plugs (3P plugs) provided with a grounding electrode and three-pole outlets (3P outlets) corresponding to three-pole plugs are increasing in plugs and outlets of load devices and the like from the viewpoint of improving safety. . Patent Document 1 discloses a 2P3P combined plug that can be used as a 2 pole plug (2P plug) for a 2 pole outlet (2P outlet) and can be used as a 3 pole plug for a 3 pole outlet.

  Specifically, the plug disclosed in Patent Document 1 includes a holding portion and an outer peripheral portion that can rotate with respect to the holding portion, and the ground plug protrudes / accommodates according to the rotational position of the outer peripheral portion with respect to the holding portion. A blocking means for blocking the ground plug at the protruding position from being accommodated in the holding portion is provided.

  In recent years, there is a need to configure the plug-connection type leakage detection breaker installed between the outlet and the load device plug so that the number of poles can be switched according to the form of the outlet.

JP 2013-45634 A

  By the way, when using a plug with the number of poles switching function as a three-pole plug, if the ground plug is not sufficiently locked at the protruding position, the ground plug will be used as the blade holder of the outlet when plugged into the three-pole outlet. It may not fit properly and may cause poor ground contact. Therefore, it is important that the ground plug is locked in a protruding state.

  In the plug of Patent Document 1, when the main body cover is biased to a predetermined position (first position) by the mainspring spring, and the rotation position of the main body cover with respect to the plug main body is the predetermined position, the ground pin is connected to the plug main body. Constructed to prevent containment.

  However, due to friction between the plug main body and the main body cover, the main body cover may not rotate to a predetermined position with respect to the plug main body, and in this case, accommodation of the ground pin in the plug main body is not prevented. If the user (operator) inserts the plug into the three-pole outlet in such a state, the above-mentioned ground contact failure occurs. In order to avoid such a state, for example, before inserting the plug into the three-pole outlet, in each case, visually confirm and apply a force in the accommodation direction to the ground plug to check whether the ground plug is locked. There is a need.

  In view of the above points, an object of the present invention is to make it possible to easily determine the state of a ground plug in a plug having a pole number switching function.

  The plug structure according to the present invention comprises a movement restricting means for restricting the movement of the ground plug to the accommodation position when the ground plug protrudes, and a movement restriction releasing means for releasing the restriction of the ground plug by the movement restricting means. Provided. Further, the display means for displaying in different display modes when the movement restriction means restricts the movement of the ground plug to the accommodation position at the protruding position and when the restriction of the earth plug is released by the movement restriction release means. Was provided. Thereby, the restricted state in which the movement of the ground plug to the accommodation position is restricted can be easily determined.

  That is, the plug structure according to the first aspect of the present invention is supported by the plug main body so as to be slidable between a protruding position protruding from the plug main body and an accommodation position accommodated in the plug main body. An earth plug urged toward the earth, a movement restricting means for restricting movement of the earth plug to the accommodation position when the earth plug is in the projecting position, and the operation force from outside the plug body. A movement restriction releasing means for releasing the movement restriction of the ground plug by the restriction means and allowing the movement of the ground plug to the accommodation position; and when the earth plug is in a restricted state by the movement restriction means. Display means for displaying in a different display mode from the state in which the restriction is released by the means.

  Note that “supported by the plug body” includes not only the case of being directly supported by the plug body but also the case of being indirectly supported by the plug body via another member.

  According to this mode, since the display mode of the display unit is different between when the ground plug is in the controlled state and when the ground plug is in the unregulated state in which the restriction by the movement restricting unit is released, the user can change the display mode. It is possible to easily determine whether it is in a restricted state or a restricted state simply by visual observation, and work and labor such as pushing in the ground plug are unnecessary.

  Further, the display means may display the same display mode regardless of the position of the ground plug in the restriction release state.

  According to this aspect, in the restriction release state, the display means displays the same display aspect regardless of the position of the ground plug. In other words, in the restriction release state, even if the ground plug is in the protruding position, display is performed in a display mode indicating the restriction release state. Thereby, display with higher safety can be realized.

  Further, the plug body has a flat plate-like rear wall portion on which the ground plug is disposed, and a cover wall portion that covers and opens a space on the front side of the rear wall portion, and the display means includes the cover It may be provided on the wall.

  According to this configuration, since the display means is provided on the covering wall portion, even when the user inserts the plug having the present plug structure into the outlet or when the plug is inserted into the outlet, the display means displays. I can confirm.

  The plug body has a display window, the display means has a different display color area, is movable in the plug body by the operating force, and the display color is passed from the outside of the plug body through the display window. The display panel may be arranged so that the region can be seen, and the display color visible through the display window may be changed by the movement of the display board by the operation force.

  According to this configuration, there is no need to provide a special circuit, sensor, or the like for the display on the display means.

  The display means may be configured to make the display mode in the transition state from the restricted state to the unrestricted state different from the display mode in the restricted state and the restricted state.

  According to this configuration, the display state of the transition state from the restriction state to the restriction release state is different from the restriction state and the restriction release state, so that the state of the ground plug can be determined in more detail.

  Furthermore, a leakage detection breaker according to a second aspect of the present invention includes an insertion plug having the plug structure, an outlet portion that is electrically connected to the insertion plug and receives a connection of a load device plug, and the insertion plug. And a leakage detection unit that detects a leakage between the outlet unit and a connection between the plug and the outlet unit when the leakage detection unit detects at least one of an overcurrent and a leakage. And a connection blocking part.

  According to this configuration, similarly to the first aspect, the user can easily determine whether it is in a restricted state or a restricted state simply by visually observing the display form, and there is no need for work and labor such as pushing in the ground plug. It becomes.

  According to the present invention, since the display means for changing the display mode according to the state of the ground plug is provided, the state of the ground plug can be easily determined.

It is the perspective view which looked at the plug which concerns on embodiment from the diagonally left upper side. It is the perspective view which looked at the pole number switching structure from the diagonal upper side ahead. It is the III-III sectional view taken on the line of FIG. It is the perspective view which looked at the pole number switching structure from the back diagonally upper side. It is a figure for demonstrating the accommodation operation | movement and protrusion operation | movement of a ground plug. It is a figure for demonstrating the accommodation operation | movement and protrusion operation | movement of a ground plug. It is a figure for demonstrating the accommodation operation | movement and protrusion operation | movement of a ground plug. It is a figure for demonstrating the accommodation operation | movement and protrusion operation | movement of a ground plug. It is a figure for demonstrating the change of the display means which concerns on the insertion to the 3 pole outlet of a plug. It is a figure for demonstrating the change of the display means which concerns on insertion of the plug to the 2 pole outlet. It is a figure for demonstrating the change of the display means which concerns on the mistaken insertion of the plug to the 3 pole outlet.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The following description of the preferred embodiments is merely exemplary in nature and is not intended to limit the invention, its scope of application, or its application.

<Outline of plug>
FIG. 1 shows a plug 10 according to this embodiment. Although not shown, the plug 10 is a leakage detection breaker that is arranged between an outlet installed at a construction site or a building and a load device and electrically connects the two. The plug 10 instantaneously detects this when a leakage occurs in the load device, and cuts off the supply of commercial power to the load device. The plug 10 has a feature that it can be used without an adapter both when the outlet is a three-pole outlet with a ground plug insertion hole and when the outlet is a two-pole outlet without a ground plug insertion hole.

  Hereinafter, in the state where the plug 10 is inserted into the outlet, the front side is referred to as “front” and the side facing the outlet is referred to as “rear”. Further, in the plug plug protruding from the rear wall of the plug body 20 described later, the side from which the electrode plug protrudes is referred to as “upper”, and the side from which the ground plug protrudes is referred to as “lower”. Define left and right based on direction.

  The plug 10 includes a cylindrical plug body 20 having a size (for example, 110 × 50 × 55 mm) that a user (operator) can hold with one hand, and the number of poles switching structure 40 and leakage protection are provided in the plug body 20. The part 50 is accommodated. The plug body 20 can be separated forward and backward at the center portion in the front-rear direction, and FIG. 1 shows a state where the plug body 20 is separated forward and backward. The plug body 20 includes a front cover 20a constituting the front half and a rear cover 20b constituting the rear half. The front cover 20a has a bottomed box shape that opens to the rear side, and the rear cover 20b has a bottomed box shape that opens to the front side. Further, an engagement claw 20c is provided at the left end of the front cover 20a, and an engagement recess 20d that can be engaged with the engagement claw 20c is provided at the rear cover 20b at a position corresponding to the engagement claw 20c. It has been. Then, the engaging claw portion 20c of the front cover 20a and the engaging concave portion 20d of the rear cover 20b are engaged with each other with the openings of the covers 20a and 20b abutting each other. As a result, the covers 20a and 20b are integrally assembled to form the plug body 20, and a closed space is formed therein. After the assembly, the front cover 20a and the rear cover 20b are screwed and fixed at four corners on the rear surface side of the rear cover 20b by tapping screws (not shown). Hereinafter, the plug body 20 simply refers to the plug body after the screwing and fixing. That is, the plug body 20 after screwing and fixing is a front wall portion formed of the bottom wall of the front cover 20a, a rear wall portion disposed on the rear side of the front wall portion and formed of the bottom wall of the rear cover 20b, It consists of surrounding walls of both the front cover 20a and the rear cover 20b, and has four side walls that connect the front wall and the rear wall. The said side wall part is comprised by the up-and-down and right-and-left wall part. The covering wall part is composed of a front wall part and four side wall parts.

  Although not shown, the leakage protection unit 50 includes a leakage detection unit that detects leakage, and a connection blocking unit that blocks connection between the input and output of the plug when the leakage detection unit detects overcurrent / leakage. . Conventional configurations can be applied to the configurations of the leakage protection unit and the connection blocking unit, and detailed description thereof is omitted here.

  On the rear wall portion of the plug main body 20, an insertion plug 25 composed of two electrode plugs 29, 29 and a ground plug 27 projects from a position near the upper end. A crimp terminal 26 having a function of a ground terminal of the plug 10 is provided at the lower left corner of the same rear wall. The plug 10 is configured to electrically connect the outlet and the load device by inserting the plug 25 into the outlet and inserting the plug of the load device into the three-pole outlet portions 31 and 31 described later.

  On the front wall portion of the plug main body 20, push-type ON buttons 23 and test buttons 24 are arranged in the order of description from the top at intermediate positions in the vertical and horizontal directions. The ON button 23 is a switch that turns on the supply of commercial power to a load device (sets the connected state). The test button 24 turns off the supply of commercial power to the load device in order to check whether the plug 10 operates normally (that is, whether the supply of commercial power to the load device is interrupted when a leakage occurs). It is a switch to be set to (blocking state).

  In addition, on the front wall portion of the plug body 20, a single insertion port 31 (corresponding to a three-pole plug) for inserting a plug of a load device or the like is provided below the test button 24. Although not shown, one similar insertion port is also provided at the center of the lower wall portion which is a part of the side wall portion of the plug body 20. In the lower part of the plug main body 20, a common blade receiving bracket 32 to which a power plug and a grounding plug of a load device or the like inserted from both the insertion ports 31 is fitted is provided.

  On the front wall of the plug body 20, the power supply display unit 21 is provided at a position near the left end above the ON button 23, and the pole number display unit 22 is provided at a position near the right end so as to be at the same height. ing.

  The power display unit 21 is composed of, for example, an LED. When it is detected that the ON button 23 has been pushed and inserted into the outlet, it is possible to energize between the outlet and the load device via the plug 10. Lights when the camera is in a bad state. Thereby, the user who uses the plug 10 can grasp that the commercial power and the load device are normally conducted. On the other hand, the power source display unit 21 is turned off when the plug 10 is in a non-energized state, for example, when an interruption operation is performed by the leakage protection unit 50 that detects overcurrent or leakage. As a result, the user can grasp that an overcurrent or a leakage has occurred, or that the test has been performed normally.

  After the overcurrent or leakage occurs, and after the confirmation of the operation of the plug 10 by the test button 24 is completed, the plug 10 can be used again as a leakage detection breaker by pressing the ON button 23 again. Become.

  The pole number display part 22 represents the state of the number of poles of the plug 25, and a pole number display window 22a formed through the front wall of the plug body 20 and a plug on the rear side of the pole number display window 22a. It consists of a color display section 46a, which will be described later, arranged in the main body 20. In other words, the pole number display unit 22 is configured so that the display color of the color display unit 46a can be seen through the pole number display window 22a.

  In the left wall portion of the plug body 20, a circular recess 28 a having a peripheral wall portion having an arcuate cross section is formed at a position near the upper end. A rectangular button insertion hole 28b is formed so as to penetrate the left side wall portion from the bottom to the front end of the recess 28a. A push-type release button 41 as an operation means is movably inserted into the button insertion hole 28b. The release button 41 has a rod portion 41c extending in the right direction, and prevents the plug body 20 from coming off at a position (hereinafter also referred to as a button reference position) where a tip end (left end portion) projects out of the plug body 20. Has been. The release button 41 is always urged in the protruding direction by a release button spring 42 (see FIG. 2) around the rod portion 41c. That is, the release button 41 is configured to be pushed into the plug body 20 when an operating force is applied, and to return to the protruding position when the operating force is released.

-Configuration of pole number switching structure-
Next, the pole number switching structure will be described in detail with reference to FIGS.

  The ground plug 27 is provided at a position corresponding to the ground pole of the three-pole outlet. The ground plug 27 includes a round bar-shaped ground plug body 27 a that is slidably supported between a protruding position protruding from the plug body 20 and a housing position accommodated in the plug body 20. The base end portion (front end portion) of the ground plug main body 27a is folded back so as to extend outward in the radial direction of the ground plug main body 27a and then extend toward the distal end side (rear side) of the ground plug main body 27a. An L-shaped switching plate 27b serving as a locking portion is integrally projected. Although not shown, a circular plug insertion hole slightly larger than the outer diameter of the ground plug body 27a is formed through the rear wall portion of the plug body 20 so as to penetrate therethrough. An earth plug main body 27a is inserted into the plug insertion hole with the tip portion directed outward from the plug main body 20. Thus, the ground plug 27 is prevented from being detached from the rear wall portion of the plug body 20 by the switching plate 27b.

  In the plug main body 20 on the front side of the plug insertion hole, a display cylinder 43 is provided as a movement restriction release means. The display cylinder 43 has a display cylinder main body 43a as a cylindrical rotating body extending in the front direction in the plug main body 20 on the front side of the plug insertion hole. The display cylinder main body 43a is supported by the plug main body 20 so as to be rotatable around the center thereof. The inner diameter of the display cylinder main body 43a is slightly larger than the outer diameter of the ground plug main body 27a. , Communicated with the plug insertion hole.

  The ground plug main body 27a is inserted into the display tube main body 43a from the opening on the rear end side. Is slid between the housing position where it is immersed in the display cylinder main body 43a. When the ground plug main body 27 a is immersed to the storage position, the ground plug 27 is positioned at the storage position where the ground plug 27 is stored in the plug main body 20.

  Further, the display tube main body 43a is formed with a cutout portion 43b in which a part of the wall portion is cut out in a rectangular shape from the rear end to the middle in the length direction of the display tube main body 43a. . The width of the cutout portion 43b, which is the length along the circumferential direction of the display cylinder main body 43a, is formed slightly larger than the lateral width of the switching plate 27b. The switching plate 27b is arranged in a state where a part of the switching plate 27b protrudes toward the outside of the display tube main body 43a. Thereby, the switching plate 27b integrated with the ground plug body 27a moves while being guided by the notch 43b in the notch 43b.

  Further, the display cylinder main body 43a is disposed in the plug main body 20 so as to be rotatable and so that the front end faces the rear surface of the front plate of the plug main body 20 in a close state. A coil spring 44 as an earth plug biasing means is inserted into the display cylinder main body 43a from the front side of a center hole 48c formed in a base portion 48a of a transmission plate 48 described later. The coil spring 44 is contracted between the front wall portion of the plug main body 20 and the base end portion of the ground plug main body 27a, and urges the ground plug main body 27a from the housing position toward the protruding position. Yes.

  A lock plate 45 is disposed inside the plug main body 20, and the lock plate 45 is fixed to the plug main body 20 by, for example, a tapping screw 45c. The lock plate 45 is switched when the ground plug 27 sufficiently protrudes outward from the plug body 20 and moves to the protruding position so that it can be inserted into a three-pole outlet (hereinafter also referred to as a three-pole lock state). It arrange | positions at the accommodation direction side of the board 27b. 2 to 4 show the three-pole locked state of the pole number switching structure 40.

  Specifically, the lock plate 45 includes a base portion 45a extending along the vertical direction, and a mounting portion 45b extending to the right and continuing to the rear end portion of the base portion 45a. The mounting portion 45b is a tapping screw 45c. Thus, the plug body 20 is fixed. A restricting portion 45e extending horizontally in the front-rear direction is continuous with the lower end portion of the base portion 45a. At the rear end of the restricting portion 45e, a locked portion 45f is formed as movement restricting means. The locked portion 45f is disposed so as to face the front side of the switching plate 27b of the ground plug 27 and interfere with the switching plate 27b when the ground plug 27 moves to the protruding position. In this interference state, the movement of the ground plug 27 in the accommodation direction is restricted, and it can be used stably as a three-pole plug. Further, the front portion of the restricting portion 45e is continuous with a spring support portion 45d extending in the left direction.

  In the present embodiment, “interference” is a concept including that the object is prevented from moving by directly or indirectly engaging the object. Specifically, for example, the switching plate 27b and the lock plate 45 are brought into contact with each other, and the switching plate 27b and the lock plate 45 are in close proximity to each other and indirectly locked therebetween. It is a concept that includes both. The “locking operation” in which the movement of the earth plug in the accommodation direction is restricted by returning from the state of the two-pole plug inserted into the two-pole outlet to the three-pole plug will be described later in “Projection action of the earth plug”. This will be described in detail.

  Further, the restricting portion 45e of the lock plate 45 has a right end surface extending from the right end of the locked portion 45f toward the right front side, that is, inclined at a predetermined angle with respect to the protruding direction of the ground plug 27. An inclined surface 45g is formed. By the inclined surface 45g, when the ground plug 27 moves from the projecting position to the accommodation position, the display cylinder main body 43a is rotated together with the switching plate 27b in sliding contact with the switching plate 27b.

  In addition, a transmission plate 48 is integrally provided at the front end portion of the display cylinder main body 43a. The transmission plate 48 includes a disc-shaped base portion 48a that is concentrically fixed to the display cylinder main body 43a, and a protruding portion 48b that protrudes radially outward from a part of the outer peripheral portion of the base portion 48a. On one side in the width direction of the projecting portion 48b, a rectangular plate-shaped transmission portion 48d extending in parallel with a plane passing through the rotation center of the display tube main body 43a is integrally projected. The transmission portion 48d is disposed so as to face the tip of the rod portion 41c of the release button 41. Then, the release button 41 is pushed against the urging force of the release button spring 42 to push the transmission portion 43 c at the tip of the rod portion 41 c, thereby rotating the transmission plate 48 and integrating with the transmission plate 48. The display cylinder main body 43a is rotated around the center. That is, when the release button 41 is pushed toward the right side, the transmission plate 48 rotates in the turning direction (clockwise direction) integrally with the display cylinder main body 43a according to the pushing amount of the release button 41. To do.

  Further, on the other side in the width direction of the protruding portion 48b of the transmission plate 48, an arc plate-shaped display plate 46 extending around the rotation center of the display tube main body 43a is integrally formed at one end portion in the circumferential direction. . The display plate 46 is disposed so as to correspond to the pole number display window 22a of the plug body 20. A white sheet 46b extending from an end (one end) located on the transmission portion 48d side in the circumferential direction to the intermediate position on the front surface (surface on the pole number display window 22a side) of the display plate 46, and the other end from the intermediate position A sheet-like color display portion 46a composed of a green sheet 46c extending up to is attached. In each figure, the white sheet 46b is indicated by a diagonal line rising to the right, and the green sheet 46c is indicated by a diagonal line rising to the left. In the present embodiment, the color display unit 46a is configured by two-color sheets, that is, the white sheet 46b and the green sheet 46c, but may be three or more colors, and each sheet is white. Different colors other than green may be used.

  In the present embodiment, when the release button 41 is not pressed, the display cylinder main body 43a, the transmission plate 48, and the display plate 46 are urged by a rotation urging force of an automatic lock spring 47 described later. In this state, green is displayed on the pole number display section 22 (the green sheet 46c is visible from the pole number display window 22a). Further, in the process of rotating the display cylinder main body 43a, the transmission plate 48, and the display plate 46 from the non-rotation state when the release button 41 is pushed, the pole number display unit 22 gradually reduces the green area while white. When the display cylinder main body 43a, the transmission plate 48, and the display plate 46 are rotated to the maximum angle by being pushed to the unlocking position described later, white is displayed on the pole number display unit 22 (poles). The white sheet 46b can be seen from the number display window 22a).

  An automatic lock spring 47 is wound around the outer periphery between the base end portion of the display cylinder main body 43a and the base portion 48a of the transmission plate 48 as a return urging means comprising a torsion coil spring. One end of the automatic lock spring 47 is engaged with the transmission plate 48 of the display cylinder 43, and the other end is engaged with the spring support portion 45 h of the lock plate 45. The automatic lock spring 47 biases the display cylinder 43 in a direction to return to the three-pole locked state, in other words, in a return direction (counterclockwise direction in FIG. 3) opposite to the rotation direction.

  The pole number switching structure 40 includes a switching plate 27b of the ground plug 27, a release button 41, a release button spring 42, a display tube 43, a ground expansion spring 44, and a lock plate 45.

  The guide means includes an inclined surface 45g of the lock plate 45, a display cylinder 43 and an automatic lock spring 47, and guides the switching plate 27b in the protruding direction along the inclined surface 45g of the lock plate 45.

<Plug pole number switching operation>
Next, the pole number switching operation of the plug 10 will be described in detail with reference to FIGS.

-Ground plug accommodation operation-
FIG. 5 shows a case where the release button 41 is in the button reference position and the ground plug 27 is in the protruding position, that is, the plug is in the three-pole locked state. As shown in FIG. 5B, when the ground plug 27 is in the protruding position, the switching plate 27b and the locked portion 45f of the lock plate 45 interfere with each other so that the ground plug 27 moves in the accommodation direction. Be regulated.

  In this interference state, for example, even if a force in the housing direction is applied to the ground plug 27 due to a reaction force from the blade receiving bracket of the outlet against the insertion of the ground plug 27 into the three-pole outlet, the front plate of the switching plate 27b is locked. Since the locked portion 45f of the plate 45 is abutted and locked, the protruding state of the ground plug 27 is maintained. That is, FIG. 5 shows a three-pole plug state (three-pole lock state) in which the plug 10 corresponds to a three-pole outlet. At this time, the green color of the green sheet 46 c on the display plate 46 is displayed on the pole number display unit 22 of the plug body 20.

  Hereinafter, the accommodating operation of the ground plug 27 will be described in detail. That is, the operation of switching the number of poles from the three-pole locked state to the two-pole plug and the operation of inserting into the two-pole outlet will be described.

  First, the number of poles of the plug 10 is switched from the three-pole locked state to the two-pole plug by the user. Specifically, the release button 41 is pushed by the user holding the plug body 20 against the urging force of the release button spring 42 and the rotation urging force of the automatic lock spring 47 from the three-pole locked state of FIG. Is done. Then, the transmission portion 48d of the transmission plate 48 is pushed and moved by the rod portion 41c of the release button 41, and the display cylinder main body 43a integrated with the display plate 46 and the transmission plate 48 is rotated in the clockwise direction (FIG. 5A). Rotate in the direction of rotation). Along with this rotation, the notch 43b of the display tube main body 43a also moves in the rotation direction, so that the switching plate 27b is also pushed by the display tube main body 43a and moves in the rotation direction. Here, since the lock plate 45 is fixed to the plug body 20 and does not follow and rotate, the relative position in the rotation direction between the switching plate 27b and the locked portion 45f of the lock plate 45 (viewed from the accommodation direction). The position of each other changes. Although not shown in the figure, in the pole number display unit 22, while the green region gradually decreases, the white region due to the white sheet 46 b on the display plate 46 gradually increases.

  When the release button 41 is further pushed by the user, as shown in FIG. 6 (b), the switching plate 27b is such that the left end of the switching plate 27b is inclined with the locked portion 45f (locked portion surface) of the lock plate 45. Move to the boundary with the surface 45g. In the state of FIG. 6, the switching plate 27b is not locked by the locked portion 45f. As a result, when a force in the direction toward the accommodation position is applied to the ground plug 27, the switching plate 27b gradually rotates along the inclined surface 45g against the biasing force of the coil spring 44 together with the ground plug 27. While moving in the accommodation direction. That is, in the state of FIG. 6, the interference of the ground plug 27 by the lock plate 45 is released, and the movement of the ground plug to the accommodation position is permitted. Hereinafter, for convenience of explanation, the position of each component in FIG. 6 may be referred to as an unlock position, and the state of FIG. 6 may be referred to as an unlock state. At this time, as shown in FIG. 6A, the pole number display unit 22 displays white.

  After the state shown in FIG. 6, the user performs an operation of inserting the plug 10 into the outlet. Since the two-pole outlet does not have a ground pole, the tip of the ground plug 27 is pressed against the surface of the outlet cover by the above insertion operation, and receives a pressing force from the outlet cover in the accommodation direction. In response to the pressing force in the housing direction, the ground plug 27 moves in the housing direction, and the amount of protrusion to the outside of the plug body 20 gradually decreases. Note that the operation of the release button 41 may be canceled once the ground plug 27 is once accommodated in the display cylinder main body 43a. Even when the operation is released, the movement of the ground plug 27 in the accommodation direction can be continued by continuing the insertion operation into the two-pole outlet.

  FIG. 7 shows a state of the pole number switching structure 40 while the plug 10 is being inserted into a two-pole outlet (in the middle of connection). As shown in FIG. 7B, the ground plug 27 is accommodated in the plug body 20 (in the display cylinder body 43a) up to an intermediate position of the ground plug body 27a.

  FIG. 8 shows a state of the pole number switching structure 40 when the plug 10 is completely connected to the two-pole outlet, that is, when the ground plug 27 is in the accommodation position. As shown in FIG. 8B, the ground plug 27 is accommodated in the plug main body 20 (in the display cylinder main body 43a) over substantially the entire axial direction of the ground plug main body 27a. At this time, the rear end of the ground plug 27 remains in contact with the outlet cover. That is, the accommodation position is a concept including a state where the ground plug 27 is not completely accommodated in the plug body 20. In addition, as shown to Fig.7 (a) and FIG.8 (a), on the pole number display part 22, white is continuously displayed from the display state of FIG.

-Projection action of the ground plug-
Next, the number of poles switching operation from the state in which the plug 10 is inserted into the two-pole outlet to the return to the three-pole locked state will be described in detail. In the above-described return operation, the operation of the release button 41 is unnecessary, and in the following description, it is assumed that the release button 41 is not pressed.

  When the plug 10 is moved in the direction of removal from the two-pole outlet (forward direction), the switching plate 27b is connected to the lock plate 45 mainly by the component of the rotational biasing force of the automatic lock spring 47 in addition to the biasing force of the ground expansion spring 44. It moves in the protruding direction while rotating along the inclined surface 45g, and the ground plug 27 gradually protrudes out of the plug body 20 while rotating in the same manner. Specifically, since the inclined surface 45g of the lock plate 45 is inclined with respect to the return direction, the ground plug 27 has a component force in the return direction and a protrusion direction in the rotation direction of the automatic lock spring 47. A component force is given. The switching plate 27b is pressed against the inclined surface 45g by the component force in the return direction. Further, the switching plate 27b is pushed in the projecting direction by the component force in the projecting direction, and the movement of the earth plug 27 in the projecting direction is supported. By the movement of the switching plate 27b, the notch 43b of the display cylinder main body 43a is also rotated in the return direction.

  Then, when the switching plate 27b reaches the boundary (lock release position) between the inclined surface 45g of the lock plate 45 and the locked portion 45f, the switching plate 27b rotates in the return direction, as shown in FIG. Automatically returns to the pole lock state.

<Insert operation of the plug into the outlet>
9 to 11 are diagrams showing the state of the release button 41, the position of the ground plug 27, and the display state of the pole number display unit 22 related to the operation of inserting the plug 10 into the outlet. Specifically, FIG. 9 is an example of a three-pole outlet, and FIG. 10 is an example of a two-pole outlet. Further, FIG. 11 shows, as a comparative form, an insertion operation when the plug is inserted into a three-pole outlet in an unlocked state. Note that a state before connection in which the user has not operated the release button 41 is defined as an initial state. That is, in the initial state, the plug 10 is in a locked state.

  As shown in the column of “connection flow” in FIG. 9, in the insertion operation of the three-pole outlet, the user can operate the plug 10 without operating the release button 41 from the initial state to the completion of the connection to the three-pole outlet. Can be plugged into a three-pole outlet. Since the release button 41 is not operated, the ground plug 27 is locked at the protruding position from the initial state to the completion of connection, and green is continuously displayed on the pole number display unit 22 (FIGS. 9A to 9C). )reference). As shown in the “others” column of FIG. 9, when the release button 41 is pressed after the plug 10 is connected to the three-pole outlet and the ground plug is unlocked, the position of the ground plug is Even in the protruding state, white is displayed on the pole number display unit 22 (see FIG. 9D).

  As shown in FIG. 10, in the insertion operation of the two-pole outlet, when the user unlocks the ground plug by pressing the release button 41, the pole number display unit 22 displays white (see FIG. 10). 10 (b)). Thereafter, in the process of inserting the plug 10 into the two-pole outlet, the ground plug 27 gradually sinks into the plug main body 20 (display cylinder main body 43a) from the protruding position toward the accommodation position. At this time, the pole number display unit 22 continues to display white. Even if the user cancels the operation of the release button 41 after the connection is completed and the release button 41 returns to the button reference position, the display of the pole number display unit 22 remains white (see FIGS. 10C to 10D). ). In addition, even when the user cancels the operation of the release button 41 while the two-pole outlet is connected and the release button 41 returns to the button reference position, the user can continue the insertion operation. The display unit 22 continues to display white. On the other hand, when the user cancels the operation of the release button 41 in the middle of the connection to the two-pole outlet, stops the connection operation of the two-pole outlet, and releases the contact state between the ground plug 27 and the outlet, the plug 10 The three-pole lock state is automatically restored, and the pole number display unit 22 displays green.

  As shown in FIG. 11, when the unlock button 41 is pressed in the insertion operation of the three-pole outlet, when the ground plug 27 is in the unlocked state, white is displayed on the pole number display unit 22 (FIG. 11). (See (b)). When the ground plug 27 receives a reaction force from the blade receiving bracket of the outlet during connection to the two-pole outlet, the ground plug 27 moves to an intermediate position between the protruding position and the storage position, and is connected to the three-pole outlet. The same state continues after the connection is completed. After the connection is completed, even if the user releases the operation of the release button 41 and the release button 41 returns to the button reference position, white is continuously displayed on the pole number display unit 22. Thereby, even if a third party other than the user who performed the insertion operation looks at the plug 10 after the connection is completed, it can be easily determined that an erroneous operation has been performed.

  As described above, according to this embodiment, when the ground plug 27 is urged in the protruding direction by the ground expansion spring 44 and the ground plug 27 is moved to the protruding position, the lock plate 45 is disposed on the front side of the switching plate 27b. Thus, the switching plate 27b and the locked portion 45f interfere with each other, and the movement of the ground plug 27 to the accommodation position is restricted. That is, as long as the user does not operate the release button 41, the plug 10 is configured to be a three-pole plug. When the plug 10 is locked to the three-pole plug, green is displayed on the pole number display unit 22, while when the lock is released, green is displayed on the pole number display unit 22. Accordingly, the user can easily determine whether the plug is in the three-pole locked state or the unlocked state in which the three-pole lock is released.

  The display differs depending on whether the ground plug 27 is locked or unlocked regardless of whether the release button is operated or not, and whether the ground plug is electrically connected to the blade receptacle of the outlet. Therefore, a more secure display can be realized. Specifically, even in a state where movement of the ground plug in the accommodation direction is permitted (see, for example, the column (d) in FIG. 11), the ground plug may be electrically connected to the blade receptacle of the outlet. Such an unstable connection state should be avoided. In this embodiment, white is displayed on the pole number display unit 22 in such a state.

  More specifically, in the plug according to the embodiment, when the ground plug is in the projecting position, the ground plug is unlocked when an operation force is applied to the movement restriction releasing means. On the other hand, when the ground plug is in the protruding position, it is characterized in that it is configured to be locked when the operating force is released. In addition, the display means displays a locked state even when the ground plug is changed from the unlocked state to the locked state due to the release of the operating force. On the other hand, in the unlocked state, the pole number display unit 22 is configured to display white regardless of the position of the ground plug 27. Thereby, more reliable and safe display can be realized.

  Moreover, since the pole number display part 22 is provided in the front wall part of the plug main body 20, even when the user inserts the plug 10 into the outlet or when the plug 10 is inserted into the outlet, the pole number display part 22 Can be confirmed, and the locked state of the ground plug 27 can be easily grasped.

  Further, the pole number display unit 22 is a process in which the release cylinder 41 is pushed and the display cylinder main body 43a, the transmission plate 48, and the display plate 46 are rotated from the non-rotating state, that is, the unlocked state from the locked state of the ground plug. In the transition state, the pole number display unit 22 is configured to display two colors of green and white through the display window 22a. Thereby, it becomes possible to grasp whether the ground plug 27 is in the locked state or the transition state.

<Other embodiments>
Although the embodiments of the present invention have been described above, various modifications can be made.

  For example, in the embodiment described above, the display color of the pole number display unit 22 is configured to be different based on the locked / unlocked state of the ground plug 27, but the present invention is not limited to this. For example, the display color may be varied based on whether the ground plug 27 is at the protruding position or at a position other than the protruding position. Specifically, in FIG. 6, it can be realized by moving the boundary between the white sheet 46b and the green sheet 46c in the color display unit 46a to the virtual line 46d. Thus, the timing at which the color display changes can be adjusted by moving the boundary between the white sheet 46b and the green sheet 46c.

  Moreover, although the example which provides the display sheet of 2 colors was shown in the said embodiment, 3 or more colors may be sufficient. For example, as shown in FIG. 8, when the plug 10 is completely connected to the two-pole outlet, a display color other than green and white may be displayed. For example, in FIG. 8, the other color sheet may be provided on the transmission unit 48d side from the white sheet 46b of the color display unit 46a, and the boundary between the white sheet 46b and the other color sheet may be provided at the position of the virtual line 46e.

  Moreover, the display of the pole number display part 22 is not limited to the display using the sheet-like color display part 46a, For example, you may use light emitting elements like LED. Further, the method of changing the display mode is not limited to the method of changing the color. For example, the display mode may be varied in the form of lighting and flashing.

  Moreover, although the pole number display part 22 shall be provided in the front wall part of the plug main body 20, in addition to or instead of the pole number display part 22 provided in the front wall part, the pole number display part 22 is provided. The plug body 20 may be provided on the four side walls of the plug body 20, and the same effect can be obtained.

  Further, the above embodiment shows an example of the lock structure and the lock release structure at the projecting position of the ground plug 27, and the configuration is not limited. That is, it is only necessary that the ground plug 27 is in an automatic lock state at the protruding position, and that the automatic lock can be released by applying a manipulation force by the user, and the same effect as in the above embodiment can be obtained. For example, the automatic lock of the ground plug 27 is released by the release button 41, but the automatic lock may be released by rotating a part of the plug body 20.

  Furthermore, in this embodiment, although the example of the earth-leakage detection circuit breaker was demonstrated as a plug, it is not limited to this. For example, the present invention can be applied to other plugs, and the state of the ground plug can be easily determined as in the present embodiment. For example, when the other plug is a plug having a flat plate-like rear wall portion provided with a ground plug and a cylindrical peripheral wall portion extending forward from the peripheral end of the rear wall portion, the display means is What is necessary is just to provide in a surrounding wall part.

  Since the present invention is configured so that the state of the earth plug can be easily discriminated, it can be applied to a plug having a pole number switching function for a wide range of uses including an earth leakage detection breaker and is extremely useful. is there.

10 Plug (plug structure, earth leakage breaker)
20 Plug body 22 Number of poles display (display means)
22a Pole number display window (display window)
27 Ground plug 43 Display tube (movement restriction release means)
45e Restriction part (movement restriction means)
46 Display board

Claims (6)

A ground plug that is supported by the plug body so as to be slidable between a projecting position projecting from the plug body and a housing position housed in the plug body, and biased toward the projecting position;
A movement restricting means for restricting movement of the ground plug when the ground plug is in the protruding position;
Movement restriction releasing means for releasing movement restriction of the ground plug by the movement restriction means by operating force from outside the plug body, and allowing movement of the earth plug to a storage position;
A plug structure comprising: display means for displaying in different display modes when the ground plug is in a restricted state by the movement restricting means and in a state of being released from restriction by the movement restricting means. The plug structure according to claim 1, wherein
The plug structure characterized in that the display means displays the same display mode regardless of the position of the ground plug in the restriction release state. The plug structure according to claim 1 or 2,
The plug body is a flat rear wall portion on which the ground plug is disposed,
A cover wall portion that covers and opens a space on the front side of the rear wall portion,
The plug structure characterized in that the display means is provided on the covering wall. The plug structure according to any one of claims 1 to 3,
The plug body has a display window,
The display means has a display plate having different display color areas, arranged so that the display color area can be seen through the display window from the outside of the plug body and movable by the operation force. The plug structure is configured such that the display color seen through the display window is changed by the movement of the display plate by the operation force. The plug structure according to claim 1, wherein
The plug structure is characterized in that the display means is configured so that a display mode in a transition state from the restricted state to the restricted state is different from a display state in the restricted state and the restricted state. An insertion plug including the ground plug of the plug structure according to any one of claims 1 to 5 and an electrode plug;
An outlet portion that is electrically connected to the plug and receives a connection of a load device plug;
An earth leakage detection unit for detecting an earth leakage between the plug and the outlet unit;
Leakage detection interruption characterized by comprising a connection interruption part for cutting off the connection between the plug and the outlet part when the leakage detection part detects at least one of overcurrent or electric leakage vessel.

Images