JP2009193785A - Thermal overload relay - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve a linking structure of an adjustment dial and a release lever so that reliability is enhanced, by suppressing the effect of deformation of an outer case due to thermal expansion or swelling on operating characteristics, and so that reduction in the number of parts and space saving of the outer case are realized. <P>SOLUTION: In the thermal overload relay in which a linking assembly of a main bimetal 2, curved by receiving energizing heating of a main circuit current, a shifter 3 which is driven-shifted to curving of the main bimetal, a release lever 5 made to be confronted with a reverse spring 7 for driving of a contact switching mechanism 6 by being linked to the shifter, and an adjustment dial 11 to position the release lever according to setting of a setting current value is internally installed in the outer case 1, and in which the switching operation of the output contact is made to be carried out by acquiring the curving of the main bimetal 2 due to energization of overcurrent, the release lever 5 is directly link-connected and integrated to the adjustment dial 11 consisting of a slider 14 and a stationary spring 15; and the release lever 5 is positioned, in matching with the setting of the setting current value by the operation of the slider 14. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a thermal relay that is used in combination with an electromagnetic contactor, a circuit breaker for power distribution, and the like, and more particularly, a release lever that drives a reversing spring of a contact switching mechanism and a settling current. The present invention relates to a linkage structure with an adjustment dial for setting.

  First, the structure of a typical conventional example of the thermal overload relay described above is shown in FIG. 9 (see, for example, Patent Document 1). In the figure, 1 is an outer case made of mold resin, 2 is a main bimetal corresponding to each phase of the three-phase main circuit, 2a is a heater, and 3 is linked to the tip (free end) of the main bimetal 2 of each phase. Shifter 4 is a compensation bimetal (an ambient temperature compensation bimetal) combined with the release lever 5 with the upper end coupled to the release lever 5, and 6 is a contact opening / closing mechanism that opens and closes using the output of the release lever 5 as a trigger. It is. The contact opening / closing mechanism 6 includes a reversing spring 7 that performs a snap action by pressing the release lever 5, a slider 8 coupled to the tip of the reversing spring 7, and an output contact 9 (b contact) that responds to the movement of the slider 8. , 10 (a contact). Further, 11 is an adjustment dial for setting the set current, 12 is an adjustment link that links the cam portion 11a of the adjustment dial 11 and the release lever 5, and 13 is a reset button for manually returning the contact opening / closing mechanism 6.

  Here, the adjustment dial 11 is installed on the top of the outer case 1 by projecting a cylindrical cam portion (a circumscribed eccentric cam) 11a inward of the case. On the other hand, the adjustment link 12 is a seesaw type link extending in the vertical direction, and a bearing portion 12a formed at the center thereof is fitted to the main shaft 1a (the holder of the adjustment link 12) provided in the outer case 1. And pivotally supported. Further, a cam follower 12b is provided at the upper end of the adjustment link 12, and this cam follower 12b is brought into contact with the peripheral surface of the cam portion 11a. Further, a movable shaft 12c is provided at the lower end of the adjustment link 12, and one end of the release lever 5 is pivotally supported on the movable shaft 12c to link the adjustment link 12 and the release lever 5 so as to be rotatable. Yes.

  The release lever 5 linked to the adjustment link 12 has an output end 5a that stands up from its tip and opposes the operation end 7a of the reversing spring 7. The upper end of the compensation bimetal 4 described is fixedly coupled.

  With the above configuration, when the main bimetal 2 is bent by the heating of the heater 2a by energization of the main circuit, and the shifter 3 is displaced in the direction of the arrow A in conjunction with this, the bending of the main bimetal 2 is shifted to the shifter 3, It is transmitted to the release lever 5 through the compensation bimetal 4. As a result, the release lever 5 rotates counterclockwise (arrow B) with the movable shaft 12c of the adjustment link 12 as a fulcrum, and its output end 5a pushes the operation end 7a of the reversing spring 7. Here, when an overcurrent exceeding the set current value set by the adjustment dial 11 is applied to the main circuit and the main bimetal 2 is largely bent, the reversing spring 7 pressed by the output end portion 5a of the release lever 5 is snap actioned. By this reversing operation, the slider 8 of the contact opening / closing mechanism 6 moves in the direction of arrow C to switch the output contacts 9 and 10. Then, by this contact output signal, the magnetic contactor connected to the thermal relay is opened to interrupt the overcurrent of the main circuit. After disconnecting the main circuit (after the disconnection, the main bimetal 2 returns to normal temperature and returns to its original state), confirming the safety of the distribution circuit and pressing the reset button 13, the slider 8 moves to the left (arrow C). And the contacts 9 and 10 are restored, and the reversing spring 7 is forcibly reversed to the initial state to reset the thermal relay.

  When the setting value of the settling current is changed by turning the adjustment dial 11, the adjustment link 12 linked to the cam portion 11a of the adjustment dial 11 moves the movable shaft 12c on the lower end side in the left-right direction with the main shaft 1a as a fulcrum. As is well known, the relative position between the output end 5a of the release lever 5 and the operating end 7a of the reversing spring 7 is displaced by this movement and the operating point of the thermal relay is changed.

In the conventional example of FIG. 9, the seesaw type adjustment link 12 is used. However, as a separate adjustment lever, the lower end of the lever is pivotally supported on the outer case, and the upper end is used as the cam portion of the adjustment dial. A thermal relay is also known that employs a structure in which a release lever is link-coupled to an intermediate position of the lever after contact (see, for example, Patent Document 2).
Japanese Patent Laying-Open No. 2005-116370 (FIG. 4) Japanese Utility Model Publication No. 53-95168 (FIG. 1)

  In the above-described conventional thermal overload relay, the cam 11a of the adjustment dial 11 for setting the settling current value and the release lever 5 are linked by a separate adjustment link 12 and set by the adjustment dial 11. The operating point of the release lever 5 is positioned according to the settling current value.

  For this purpose, the outer case 1 needs to secure a space for arranging the adjustment link 12, and the main shaft 1 a that pivotally supports the adjustment link 12 on the outer case 1. The assembly structure of the thermal relay is complicated and increased in size, such as requiring a cam follower 12b to be linked and an adjusting mechanism thereof.

  Further, if the pivoting portion of the adjustment link 12 is worn or rattled due to the use environment of the thermal relay, the output end portion 5a of the release lever 5 linked to the movable shaft 12c is also displaced from the set position, and the reversing spring 7 and As a result, the operating characteristics of the thermal overload relay (the switching operation point of the output contact with respect to the set current value set by the adjustment dial 11) fluctuate.

  The present invention has been made in view of the above points, and its purpose is to suppress the influence on the operating characteristics due to the use environment of the thermal relay, and to reduce the number of parts and to save the space of the outer case. It is an object of the present invention to provide a thermal overload relay having an improved linkage structure between an adjustment dial and a release lever.

In order to achieve the above object, according to the present invention, a main bimetal that is bent by energization and heating of a main circuit current, a shifter that is displaced by the bending of the main bimetal, and a contact opening and closing linked to the shifter. A linkage assembly of a release lever facing the mechanism reversal spring and an adjustment dial that positions the release lever according to the setting of the settling current value is installed inside the outer case, and the main bimetal is energized by overcurrent. In the thermal overload relay that captures the curvature of the open and close the output contact,
The release lever is directly linked to the adjustment dial, and the adjustment dial is positioned and fixed to the outer case in accordance with the settling current set value.

In the present invention, the adjustment dial and the mounting structure thereof can be configured in a specific manner as described below.
(1) The adjustment dial linked to the release lever is composed of a slider whose top portion is fitted in a slide groove formed in the outer case and is movably guided and supported, and the slider is fixed by a fixing means. The release lever is positioned in a fixed position corresponding to the current value (claim 2).
(2) The adjustment dial linked to the release lever is composed of a disk whose outer peripheral part protrudes outward from the outer case and is pivotally supported, and the disk is fixed to the desired set current value. The release lever is positioned while being fixed at a set position corresponding to the above (claim 3).
(3) Here, as a means for fixing the slider of the above item (1), a fixing screw is provided to be screwed to the top of the slider and fastened to the outer case, and the slider is set to the set current value setting position via the fixing screw. It fixes (Claim 4). Alternatively, it is fixed to the outer case via a notch-type latch mechanism comprising a combination of an uneven tooth row formed along the slide groove of the outer case and an engagement spring that is attached to the slider and meshes with the tooth row. Item 5).
(4) On the other hand, as a fixing means for the disk of the above item (2), a fixing screw serving as a supporting shaft for fixing the disk to the outer case by screwing it to the outer case or the disk itself by aligning the position with the center of the disk. (Claim 6). Alternatively, a notch-type latch mechanism comprising a combination of an uneven tooth row formed on the plate surface along the rotating direction of the disk and an engagement spring that is attached to the outer case side and meshes with the tooth row, The disk is fixed to the outer case via the latch mechanism (Claim 7).

According to said structure, the following effect is acquired.
(1) The adjustment link in the conventional structure is omitted, the release lever is linked directly to the adjustment dial, and the release lever is positioned directly from the adjustment dial, reducing the number of parts compared to the conventional structure. , Space saving of the outer case can be achieved. Further, by omitting the adjustment lever that holds the shaft in the outer case, the influence of the adjustment link caused by the deformation of the outer case on the operating characteristics is eliminated, thereby improving the reliability of the product.
(2) Also, the adjustment dial is composed of a slider or disk, and this adjustment dial is fixed to the outer case via a fixing screw or notch type latch mechanism to determine the position of the release lever and hold it. Thus, the setting current value can be easily set and changed manually, and the adjustment dial can be prevented from being displaced from the set position.

  If the adjustment dial is composed of a slider, and the slider is guided and supported along the slide groove formed in the outer case in accordance with the operating direction of the release lever, the setting operation of the settling current performed by the adjustment dial can be performed. In addition, it is advantageous that the release lever can be accurately positioned.

  Hereinafter, embodiments of the present invention will be described based on the examples shown in FIGS. 1 is a diagram illustrating the configuration and operation of the main part according to the first embodiment of the present invention, FIG. 2 is an external view of a linkage assembly of an adjustment dial and a release lever in FIG. 1, and FIGS. In the drawings, the members corresponding to those in FIG. 9 are given the same reference numerals, and the description thereof will be omitted.

  1 is an assembly configuration diagram of the main part of a thermal overload relay corresponding to claims 1, 2 and 4 of the present invention, FIG. 2 is a perspective view of a linkage assembly of an adjustment dial and a release lever in FIG. FIGS. 3A and 3B are structural diagrams in which the adjustment dial is fixed to the outer case in accordance with the set current setting value. First, in FIG. 1, the outer case 1 includes a main bimetal 2, a shifter 3, a compensation bimetal 4, a release lever 5, a contact opening / closing mechanism 6 including a reversing spring 7, and an adjustment dial 11 shown in FIG. However, the linkage structure of the release lever 5 and the adjustment dial 11 is configured as follows.

  That is, in the illustrated embodiment, the adjustment link 12 in the conventional structure of FIG. 9 is omitted, and one end of the release lever 5 is directly linked to the adjustment dial 11. Here, the adjustment dial 11 is a slider 14 whose top is fitted in a slide groove 1b formed in the outer case 1 and is movably guided and supported. The release lever 5 is linked to the lower portion via a movable shaft 16 and linked. ing. The slide groove 1b is formed in parallel with the operation direction of the release lever 5. Further, the movable shaft 16 may be integrally formed with the slider 14 (made of mold resin).

  Further, a fixing screw (decorative screw) 15 that also serves as an adjustment handle is screwed on the convex step portion 14a formed on the top of the slider 14, and the outer case as shown in FIGS. 3 (a) and 3 (b). The fixing screw 15 screwed from outside 1 is tightened to fasten the slider 14 to the outer case 1 at a desired settling current setting position. Note that the diameter of the screw head of the fixing screw 15 is set larger than the groove width of the slide groove 1b, and the outer case 1 is sandwiched between the slider 14 and the fixing screw 15 by tightening the screw.

  In order to set and change the setting current value of the thermal relay in the assembly structure of the adjustment dial 11 described above, the slider 14 is slid to the position of the desired setting current value in accordance with the scale of the adjustment dial with the fixing screw 15 loosened. At this position, the fixing screw 15 is tightened and fixed. As a result, the release lever 5 linked to the slider 14 is positioned and held at a position corresponding to the settling current value.

  Next, with respect to the fixing means of the slider 14, applied examples in which a part of the structure shown in FIG. 3 is changed are shown in FIGS. In FIG. 4B, the outer case 1 is depicted as being divided along the slide groove 1 b in order to facilitate understanding of the fixing structure of the slider 14. In this embodiment, the top portion 14 a of the slider 14 has an H-shaped cross section and is fitted into a slide groove 1 b formed in the outer case 1, and the tip of the fixing screw 15 screwed into the top portion 14 a is inserted into the outer case 1. The slider 14 is fixed to a desired position by pressing against the plate surface. Further, in order to fit the top portion 14a having the H-shaped section of the slider 14 into the slide groove 1b of the outer case 1, an insertion groove portion 1b-1 having an increased groove width is formed at the end of the slide groove 1b.

  Next, as an application example of the first embodiment, an embodiment corresponding to claim 5 of the present invention is shown in FIGS. In this embodiment, a notch type latch mechanism is provided instead of the fixing screw 15 shown in the first embodiment, and the slider 14 of the adjustment dial 11 is fixed to a desired settling current setting position by this latch mechanism. .

  That is, in this embodiment, the top portion of the slider 14 is formed with an H-shaped top portion 14a similar to that shown in FIG. 4 and is fitted to the slide groove 1b of the outer case 1 so as to be guided and supported. Here, an uneven notch tooth row 1c is formed in the slide groove 1b along the longitudinal direction, and an inverted V-shaped engagement made of a leaf spring is formed on the slider 14 so as to face the notch tooth row 1c. A spring 17 is attached, and the convex end of the engagement spring member 17 is fitted into the concave portion of the notch tooth row 1c, and the adjustment dial 11 is positioned and held at the selected set current value setting position. Reference numeral 14 c denotes a handle formed on the top of the slider 14. With the configuration of this embodiment, the adjustment dial 11 can be adjusted by sliding the handle 14c without using a fixing screw.

  Next, an embodiment corresponding to claims 3 and 6 of the present invention is shown in FIGS. 6 (a), 6 (b), and 7. FIG. In this embodiment, the adjustment dial 11 is supported by the outer case 1 and is constituted by a disk 18 provided so as to be rotatable from the outside of the case, and the release lever 5 is linked to the disk 18 to link the settling current value. Are set and positioned.

  That is, the outer case 1 is formed with a slit-like window hole (square hole) 1d at the position where the adjustment dial is attached and a bearing portion 1e at the center of the window hole 1d, and a disk 18 is formed in the window hole 1d. After being inserted, a fixing screw 19 also serving as a spindle screwed into the bearing portion 1 e is passed through the center hole 18 a of the disk 17 and is rotatably supported. The release lever 5 is linked to a movable shaft 16 formed at the lower peripheral edge of the disk 18 (inside the outer case 1).

  Further, in the structure shown in FIG. 6, the large-diameter shaft portion 19a and the small-diameter shaft portion 19b are formed on the shaft of the fixing screw 19 also used as the support shaft, and in the structure shown in FIG. The disk 18 is screwed into a female screw formed on the inner peripheral surface of the bearing portion 1 e of the outer case 1, and the disk 18 is pivotally supported by passing the small-diameter shaft portion 19 b through the central shaft hole 18 a of the disk 18. When the fixing screw 19 is tightened in this configuration, the end face of the large-diameter shaft portion 19a is pressed against the disk 18 as shown in FIG. 6B to fix the adjustment dial at this position. In the structure shown in FIG. 7, a screw (male screw) is formed on the small-diameter shaft portion 19b of the fixing screw 19, and is screwed into a screw hole formed in the bearing portion 1e to fasten and fix the disk 18 of the adjustment dial. Yes.

  In order to set and change the settling current value in the above assembly structure, the disk 17 is turned to the position of the desired settling current value in accordance with the scale of the adjustment dial while the fixing screw 19 serving as the support shaft is loosened. Then, the fixing screw 19 is fastened and fixed. As a result, the release lever 5 linked to the disk 18 is positioned and held at a position corresponding to the settling current value.

  Next, FIG. 8 shows an embodiment corresponding to claim 7 of the present invention as an application example of the third embodiment. That is, in this embodiment, as a means for fixing the disk 18, a notch type latch mechanism is employed instead of a fixing screw so that the disk 18 of the adjustment dial is fixed at a set current setting position.

  That is, the disk 18 is pivotally supported by the bearing portion 1e of the outer case 1 via the support shaft 20, and further, the surface of the disk 18 is formed with an uneven notch groove array 18c along the circumferential direction. The outer case 1 is provided with an engagement spring 21 made of a leaf spring so as to face the notch groove row 18c, and the tip of the engagement spring 21 is fitted into the notch groove 18c so that the disk 18 of the adjustment dial is formed in a desired manner. Positioning and holding are performed at the set current value setting position.

  As a result, the adjustment dial can be adjusted without depending on the fastening screw as in the second embodiment (see FIG. 5).

Assembly diagram of thermal overload relay according to embodiment 1 of the present invention 1 is a perspective view of the assembly of the adjustment dial and release lever in FIG. 2A is an exploded perspective view, and FIG. 2B is a vertical cross-sectional view in a state of being fastened to an outer case. FIG. 4 is an explanatory view of an assembly structure of an application example corresponding to FIG. 3, (a) is an exploded perspective view, and (b) is a longitudinal sectional view. FIG. 4 is a structural diagram of an adjustment dial according to a second embodiment of the present invention, where (a) is a perspective view of an assembled state attached to an outer case, and (b) is an exploded perspective view showing the structure of a notch type latch mechanism in (a). FIG. 4 is an assembly structure diagram of an adjustment dial according to a third embodiment of the present invention, where (a) is an exploded perspective view and (b) is a longitudinal sectional view in an assembled state. FIG. 6 is a longitudinal sectional view of the assembled state showing the application example of FIG. The perspective view showing the assembly structure of the adjustment dial concerning Example 4 of this invention Configuration diagram of conventional example of thermal overload relay

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Outer case 1b Slide groove 1c Notch tooth row 2 Main bimetal 3 Shifter 4 Compensation bimetal 5 Release lever 6 Output contact opening / closing mechanism 7 Reversing spring 9, 10 Output contact 11 Adjustment dial 14 Slider 15 Fixing screw 16 Movable shaft 17 Engagement spring 18 Disk 18a Shaft hole 18b Notch tooth row 20 Fixing screw 21 also used as a support shaft Engaging spring

Claims (7)

A main bimetal that is bent by energization and heating of the main circuit current, a shifter that is displaced by the bending of the main bimetal, and a release lever that is linked to the shifter and faces the reversing spring for driving the contact opening and closing mechanism; A linkage assembly with an adjustment dial that positions the release lever according to the setting of the settling current value is installed in the outer case, and the thermal contact that opens and closes the output contact by capturing the curvature of the main bimetal due to overcurrent conduction In the type overload relay,
A thermal overload relay, wherein the release lever is directly linked to the adjustment dial, and the adjustment dial is fixed to the outer case in accordance with a set current setting value. 2. The thermal overload relay according to claim 1, wherein the adjustment dial linked to the release lever is a slider whose top is slidably guided and supported along a slide groove formed in the outer case, via a fixing means. The thermal overload relay is characterized in that the slider is fixed at a set current setting position. The thermal overload relay according to claim 1, wherein the adjustment dial linked to the release lever is a disk that is pivotally supported so that a part of its outer periphery protrudes outward from the outer case, and the fixing means is A thermal overload relay, wherein the disk is fixed at a set current setting position. 3. The thermal overload relay according to claim 2, wherein a fixing screw that is screwed to the top of the slider and fastened to the outer case is provided as means for fixing the slider. The thermal overload relay according to claim 2, wherein as the slider fixing means, an uneven tooth row formed along the slide groove of the outer case, and an engagement spring that is attached to the slider and meshes with the tooth row. A thermal overload relay characterized in that a notch type latch mechanism comprising a combination of the above is provided. 4. The thermal overload relay according to claim 3, wherein the disk is fixed to the outer case or the disk itself as a means for fixing the disk, and is fixed to the outer case by being screwed to the outer case or the disk itself. Thermal overload relay, characterized in that a fixing screw is provided. 4. The thermal overload relay according to claim 3, wherein as a means for fixing the disk, an uneven tooth row formed on the surface of the disk along a rotating direction and attached to the outer case side to mesh with the tooth row. A thermal overload relay, characterized in that a notch type latch mechanism comprising a combination with an engagement spring is provided.

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