JP2010003663A - Thermally actuated overload relay - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thermally actuated overload relay capable of reducing manufacturing cost, by reducing assembling manhours by simplifying a constitution for adjusting a setting current. <P>SOLUTION: A contour case 12 has a constitution having bimetal 26 deflecting by current-carrying of an overcurrent of a main circuit, a shifter 34 displaced in response to deflection of the bimetal, a release lever driven by displacement of the shifter, a contact point opening-closing mechanism 40 driven by the release lever 46 and opening-closing a contact point to the main circuit, a movable shaft 44 for holding the release lever, an adjusting mechanism 48 for adjusting the setting current by setting a movable position in the predetermined direction of the movable shaft by contacting with the movable shaft, and a support member 50 for linearly pressing and supporting the movable shaft in the predetermined direction so as to contact with the adjusting mechanism. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a thermal overload relay that operates a contact switching mechanism to shut off a main circuit when an overcurrent exceeding a settling current flows in a main circuit connected to a load.

This type of thermal overload relay heats the bimetal with the current of the main circuit connected to the load, and uses the bending deformation (curvature) that accompanies the temperature rise of the bimetal when the main circuit is overcurrent. It is comprised so that the electric current supply to may be interrupted | blocked.
As such a thermal overload relay, for example, those described in Patent Document 1 and Patent Document 2 below are known.

The thermal overload relay described in Patent Document 1 has a configuration as shown in FIG. This thermal overload relay includes an outer case 200 made of mold resin. The outer case 200 stores an actuator mechanism 202 and a contact opening / closing mechanism 206 that receives an operating force from the actuator mechanism 202 to operate the contact device 204.
The actuator mechanism 202 includes a heating element 208 and a main bimetal 210 to which heat generated by the heating element 208 is transmitted. The main bimetal 210 has a characteristic that the upper end is fixed to the outer case 200 and the amount of bending in a predetermined bending direction (the right side in FIG. 11) changes according to the temperature rise. The deformation force of the main bimetal 210 is transmitted as an operation force to the release lever 230 of the contact opening / closing mechanism 206 via the shifter 212 and the temperature compensation bimetal 214.

  The release lever 230 presses the reversal spring 216 from the right side by an operating force transmitted from the actuator mechanism 202 when a circuit abnormality occurs. The reversing spring 216 normally maintains a reset state in which the upper end is elastically deformed in an arc shape in the illustrated reset direction (left direction). However, the reversing spring 216 is operated by a snap action by being pressed from the right by the release lever 230 when an abnormality occurs, and is elastically deformed in an arc shape in the reversing direction (right direction) opposite to the reset direction. Inverted state.

The position of the release lever 230 in the left-right direction is adjusted by an adjustment dial 240 provided on the outer case 200 and an adjustment link 250 connected to the adjustment dial 240, and adjustment of the settling current is performed by this position adjustment.
The adjustment dial 240 has a cam portion (eccentric cam) 241 inserted inside the case and is arranged at the top of the outer case 200. The holding spring member 242 (wire spring formed by piano wire) arranged in the outer case 200 ) Is held rotatably.

  On the other hand, the adjustment link 250 is constituted by a seesaw-type link member extending in the vertical direction, and a fixed bearing portion 251 formed at the center thereof is pivotally supported on a support shaft 1 a provided in the outer case 200. ing. A cam contact 252 that functions as a cam follower is provided at the upper end of the adjustment link 250. The cam contact 252 is pressed from behind by a linear spring portion 243 formed integrally with the holding spring member 242 so as to contact the outer peripheral surface of the cam portion 241 of the adjustment dial 240.

And the release lever 230 mentioned above is pivotally supported by the movable shaft part 253 provided in the lower end of the adjustment link 250 so that rotation is possible.
The contact opening / closing mechanism 206 includes a slider 218 supported by the outer case 200 so as to be slidable in the left-right direction. The slider 218 has a slit portion 220 at one end (the right end in FIG. 8) along the sliding direction. The upper end portion of the reversing spring 216 is inserted into the slit portion 220. As a result, when the reversing spring 216 changes from the reset state to the reversing state when the slider 218 is in the illustrated first operating position, the slider 218 slides to the predetermined second operating position by the reversing force of the reversing spring 216.

  On the other hand, the contact device 204 includes a pair of contact springs 222 and 224 each having a movable contact disposed at the tip thereof, and a pair of fixed contacts disposed so as to face the movable contacts of the pair of contact springs 222 and 224, respectively. ing. The contact springs 222 and 224 can be bent and deformed between a closed position where the movable contact comes into contact with the fixed contact and an open position where the movable contact is separated. Here, one contact spring 222 constitutes a normally closed contact portion together with the fixed contact, and the other contact spring 224 constitutes a normally open contact portion together with the fixed contact.

When the slider 218 moves from the first operation position to the second operation position, the contact springs 222 and 224 are bent and deformed to displace the movable contacts from one of the closed position and the open position to the other. Thereby, in the contact device 204, the output of the contact signal from the normally closed contact portion is stopped, and the normally open contact portion starts outputting the contact signal. The contact signal from the normally open contact portion is output to a current control device such as an electromagnetic circuit breaker, and this current control device cuts off the current supply from the power source to the load through the circuit.
The contact opening / closing mechanism 206 returns the slider 218 to the first operating position when the reset button 232 is pressed while the slider 218 is in the second operating position. The slider 218 pressurizes the reversing spring 216 that has been reversed and returns it to the reset state. In conjunction with this, the contact springs 222 and 224 are restored to their original normally closed state and normally opened state, respectively.

In the structure of the thermal overload relay shown in FIG. 11, a wire spring is used as a pressurizing means for bringing the cam contact 252 provided at the upper end of the adjustment link 250 into contact with the cam portion 241 of the adjustment dial 240. The linear spring portion 243 of the spring member 242 is used. However, as a pressurizing means for the cam contact 252, a pressing spring (compression coil spring) is interposed between the adjustment link and the outer case that are pivotally supported in the outer case with the lower end of the link as a fixed shaft fulcrum. A configuration in which the tip of the adjustment link is pressed against the cam surface of the adjustment dial with this compression coil spring is also known (for example, see Patent Document 2).
Japanese Patent Laying-Open No. 2005-116370 (FIGS. 1 to 3) Japanese Patent Laid-Open No. 2-86024 (FIG. 4)

  However, in the conventional examples described in Patent Document 1 and Patent Document 2, an adjustment link is provided between the release lever and the adjustment dial in order to adjust the settling current by moving the support position of the release lever. There is a need. In addition, a structure is adopted in which a pressing spring member, which is an independent component, is combined with the adjustment link, and the adjustment link is pressed against the cam portion of the adjustment dial by the spring member.

In the conventional example having such a configuration, there is an unsolved problem that the configuration for adjusting the settling current is complicated, the number of parts is increased, the number of assembly steps is increased, and the manufacturing cost is increased.
Therefore, the present invention has been made paying attention to the unsolved problems of the above-described conventional example, and can simplify the configuration for adjusting the settling current, thereby reducing assembly man-hours and manufacturing costs. The object is to provide a thermal overload relay.

In order to achieve the above object, in the thermal overload relay according to the present invention, a bimetal that is bent by energization of an overcurrent of a main circuit, a shifter that is displaced according to the bending of the bimetal, and the shifter A release lever that is driven by the displacement, a contact opening / closing mechanism that is driven by the release lever to open and close a contact with the main circuit, a movable shaft that holds the release lever, and a movable shaft that is in contact with the movable shaft. An adjustment mechanism that adjusts the settling current by setting a movable position in a predetermined direction, and a support member that linearly presses and supports the movable shaft in the predetermined direction so as to contact the adjustment mechanism. It has a configuration.
Here, as the support member, a compression spring, a tension spring, or a link mechanism that presses and supports the movable shaft toward the adjustment mechanism can be applied.

  According to the present invention, the movable shaft holding the release lever is directly brought into contact with the adjustment mechanism, thereby adjusting the position of the movable shaft and adjusting the settling current. There is no need for a body spring member, the adjustment mechanism of the settling current can be simplified, and the effects of reducing the number of assembling steps and the production cost can be obtained.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a cross-sectional view showing a main part of a thermal overload relay showing a first embodiment of the present invention.
As shown in FIG. 1, the thermal overload relay 10 includes an outer case 12 made of mold resin that constitutes an outer portion of the apparatus. The outer case 12 is formed in a casing shape having an open front side, and a partition plate 14 extending rightward from the left side wall is formed at an intermediate position in the vertical direction.

In the outer case 12, the actuator mechanism 20 is stored below the partition plate 14, and the contact opening / closing mechanism 40 is stored above the partition plate 14.
In the actuator mechanism 20, for example, three bimetal units 22 are arranged on the left and right sides with a predetermined interval. The bimetal units 22 are separated from each other by a partition wall 24 extending upward from the bottom plate 12 a of the outer case 12. Each bimetal unit 22 is fixed to a main bimetal 26 that is formed in an elongated plate shape that extends with an inclination of, for example, about 5 degrees in the counter direction with respect to the vertical direction, and a base end portion at the bottom of the main bimetal 26. And a metal connection plate 28. Here, the three bimetal units 22 are each connected to the outer case 12 via a connecting plate 28. Thereby, the main bimetal 26 is supported in a cantilever state so that the upper end thereof is a free end.

The main bimetal 26 is covered with a cylindrical insulating sleeve 30 on its outer peripheral side, and a coil-shaped heating element 32 is spirally wound through the insulating sleeve 30. The heating element 32 has a tip fixed to the vicinity of the tip of the main bimetal 26 and is electrically connected to the main bimetal 26.
The thermal overload relay 10 is arranged in a main circuit (not shown) including a load such as a motor driven by a three-phase alternating current and a power source for supplying the three-phase alternating current to the load. The main bimetal 26 and the heating element 32 are interposed in three (R-phase, S-phase, and T-phase) power lines through which a three-phase alternating current flows. Thus, the three heating elements 32 generate heat corresponding to the current flowing through the circuit (three power lines), respectively, and transmit this generated heat to the three main bimetals 26.

  On the other hand, when the main bimetal 26 is heated by the generated heat transmitted from the heating element 32, the main bimetal 26 undergoes bending deformation in which the free end side is displaced leftward (arrow B direction) from the linear state, and the amount of bending (bending amount). Changes continuously as the temperature increases. The change in shape of the main bimetal 26 is reversible. When the amount of heat transferred from the heating element 32 decreases and the temperature decreases, the amount of bending of the main bimetal 26 decreases, and the main bimetal 26 is cooled to near room temperature. Then, the initial shape is restored.

A shifter 34 is engaged with the tips of the three main bimetals 26. The shifter 34 is slidably supported by the upper end of the partition wall 24 and is slid leftward from the state shown in FIG. 1 as the amount of bending of the main bimetal 26 increases.
A movable shaft 44 is connected to the shifter 34 via a plate-shaped temperature compensation bimetal 42, and a release lever 46 is held on the movable shaft 44. Here, the temperature compensating bimetal 42 is engaged with an engaging long hole 36 formed in the shifter 34 and extending in the left-right direction.

The movable shaft 44 is in contact with the adjustment dial 48 rotatably held on the upper surface plate 12b of the outer case 12 from the left side, that is, from the contact opening mechanism 40 side as viewed in FIG.
The adjustment dial 48 includes a large-diameter disk portion 48a formed in order from the upper side to the lower side, an engagement disk portion 48b having a smaller diameter than the large-diameter disk portion 48a, an eccentric cam portion 48c, and a pivot shaft 48d. I have. The lower surface of the large-diameter disk portion 48a is engaged with the upper surface of the upper surface plate 12b of the outer case 12, and the engagement disk portion 48b is engaged with an engagement hole 12c formed in the upper surface plate 12b. Further, the pivot 48d extends through a support piece 12e extending in the left direction formed in the right side plate 12d of the outer case 12, and a stopper washer 48e is mounted on an end protruding downward from the support piece 12e. .

  Further, as shown in an enlarged view in FIG. 2, the movable shaft 44 includes a mounting plate portion 44a extending in the vertical direction to which the temperature compensating bimetal 42 and the release lever 46 are mounted, and a right side from the upper side of the mounting plate portion 44a. And a projecting engagement portion 44c having a projecting cylindrical surface 44b formed at the projecting tip. Here, the temperature compensating bimetal 42 is attached to the attachment plate portion 44a so as to extend downward at the center of the lower surface thereof, and the release lever 46 is attached so as to extend obliquely to the lower left. Further, the protruding cylindrical surface 44b of the protruding engagement portion 44c is formed in a cylindrical surface centered on the longitudinal axis passing through one point on the extension line L1 passing through the center of the temperature compensation bimetal 42 in the left-right direction. On the other hand, an engaging groove 48f is formed in the circumferential direction on the cam surface of the eccentric cam portion 48c of the adjustment dial 48.

  The projecting cylindrical surface 44 b of the projecting engagement portion 44 c of the movable shaft 44 is engaged with the engagement groove 48 f formed in the eccentric cam portion 48 c of the adjustment dial 48. In the engaged state of the protruding cylindrical surface 44b and the engaging groove 48f, a support is provided between the left end surface of the mounting plate portion 44a and the support piece 12f formed by extending downward on the upper surface plate 12b of the outer case 12. A compression coil spring 50 as a member is provided. The compression coil spring 50 supports the movable shaft 44 while pressing the movable shaft 44 toward the eccentric cam portion 48 c of the adjustment dial 48. For this reason, the projecting cylindrical surface 44b of the projecting engagement portion 44c is engaged with the engagement groove 48f formed in the eccentric cam portion 48c of the adjustment dial 48 while the movable shaft 44 is supported by the compression coil spring 50. Therefore, it is supported without moving up and down.

The contact opening / closing mechanism 40 outputs a contact signal for opening / closing a main circuit including an electromagnetic contactor interposed between the three-phase power supply source and the three-phase load. The contact opening / closing mechanism 40 includes a reversing spring 60 that is reversed by a release lever 46, a normally closed contact portion 62, a normally open contact portion 64 and a reversing spring 60, a slider that connects the normally closed contact portion 62 and the normally open contact portion 64. 66.
The reversing spring 60 has a lower end portion fixed to a thick plate-like support bracket 72 by caulking or the like, and the support bracket 72 is fixed to the outer case 12 with screws or the like. Accordingly, the reversing spring 60 is supported in a cantilever state by the outer case 12 via the support bracket 72 so that the upper end of the reversing spring 60 becomes a free end.

  As shown in FIG. 3, the reversal spring 60 has a rectangular leaf spring portion 74 that extends in the longitudinal direction. A pair of slit portions 76 extending in the longitudinal direction of the rectangular leaf spring portion 74 are formed in parallel at a predetermined interval. As a result, the reversing spring 60 is provided with a central leg 78 and a pair of outer legs 80. The center leg portion 78 is formed with a bent portion 82 in which two bent portions, each bent in a V shape by a press process or the like, are continuous at the central portion in the longitudinal direction. In the reversal spring 60, the bent portion 82 is formed in the central leg portion 78, so that the length along the longitudinal direction of the central leg portion 78 is shorter than the pair of outer leg portions 70. For this reason, in the reversal spring 60, the pair of outer leg portions 80 receive a compressive load along the longitudinal direction from the central leg portion 78.

  Each of the pair of outer legs 80 is formed in a plate shape that is elongated along the longitudinal direction of the reversing spring 60 and sufficiently thin along the thickness direction, and is seated by a compressive load transmitted from the center leg 78. It is elastically deformed so as to have a substantially arc shape in the bending direction (reverse direction or reset direction). At this time, the restoring force of the pair of elastically deformed outer legs 80 is transmitted to the center leg 78 as a reaction force. As a result, the center leg 78 is also elastically deformed so as to be substantially arc-shaped in the same direction as the pair of outer legs 80.

  Therefore, the reversing spring 60 is bent in the reset state curved to the opposite side to the release lever 46 side as shown by the solid line in FIG. 1 and the reversal curved to the release lever 46 side opposite to the reset state as shown in the dashed line. It can be deformed to any state. The bent portion 82 on the lower side of the reversing spring 60 in the reset state is an operation portion 84 that engages with the release lever 46.

The tip of the reversing spring 60 is engaged with a slider 66, and the slider 66 is elastically deformed by the reversing spring 60, and the reset position on the left side shown by the solid line in FIG. 1 and the reversing position on the right side shown in FIG. Is slid between.
The normally closed contact portion 62 has a movable contact spring 92 supported by a support bracket 90 whose lower end is fixed to the outer case 12, and a fixed contact 94 with which the movable contact spring 92 contacts. The movable contact spring 92 is engaged with the slider 66 at the upper end. When the slider 66 is at the reset position, the contact 96 formed on the movable contact spring 92 and the fixed contact 94 are in a normally closed state. .

  Further, the normally open contact portion 64 also has a movable contact spring 102 supported by a support bracket 100 whose lower end is fixed to the outer case 12, and a fixed contact 104 with which the movable contact spring 102 contacts. The movable contact spring 102 is engaged with the slider 66 at the upper end, and in a state where the slider 66 is at the reset position, the contact 106 formed on the movable contact spring 102 and the fixed contact 104 are in a normally open state. .

  A reset button 110 is provided for returning the slider 66 to the reset position shown by the solid line in FIG. 1 while the slider 66 is in the reverse rotation position shown by the one-dot chain line in FIG. As shown in FIG. 1, the reset button 110 is slidably held on the upper surface plate 12 b of the outer case 12. The reset button 110 is always biased upward by a return spring 112. Further, the reset button 110 has an inclined surface 114 inclined downward to the right at the lower end, and the inclined surface 114 is engaged with a reset hole 66a formed in the slider 66, whereby the slider 66 is moved from the reverse position to the reset position. Return to.

Next, the operation of the first embodiment will be described.
In the thermal overload relay 10, three-phase AC of a main circuit including a magnetic contactor interposed between a load such as a motor and a power supply for supplying a three-phase AC current to the load is individually supplied to the heating element 32. ing. For this reason, when the three-phase alternating current supplied to the load of the main circuit is in a normal state, the heat generating element 32 generates little heat and is close to room temperature, and the main bimetal 26 has a substantially straight state as shown in FIG. maintain.

Therefore, as shown in FIG. 1, the shifter 34 maintains the right position, so that the temperature compensation bimetal 42 is maintained in a state of extending substantially in the vertical direction. Therefore, the movable shaft 44 also maintains the normal position shown in FIG. 1, and the release lever 46 is in contact with the bending portion 82 of the reversing spring 60. The reversing spring 60 is in the reset state shown by the solid line in FIG. ing.
In the reset state of the reversing spring 60, the slider 66 is in the reset position shown by the solid line in FIG. 1, so that the contact 96 of the movable contact spring 92 of the normally closed contact portion 62 is pressed against the fixed contact 94 to maintain the normally closed state. To do. At this time, in the normally open contact portion 64, the movable contact spring 102 is bent to the left side by the slider 66, and the contact 106 is dissociated from the fixed contact 104 to maintain the normally open state.

In this normal state, when setting the settling current for reversing the reversing spring 60, for example, the state where the protruding cylindrical surface 44b of the movable shaft 44 is in contact with the minimum diameter position of the eccentric cam portion 48c shown in FIG. It will be explained as being.
First, a scale position (not shown) formed on the upper surface of the adjustment dial 48 is set to a desired position. Accordingly, the eccentric cam portion 48c rotates and the diameter of the eccentric cam portion 48c increases, so that the position of the movable shaft 44 is linearly displaced in the left direction against the compression coil spring 50. At this time, since the release lever 46 supported by the movable shaft 44 is in contact with the operation portion 84 of the reversing spring 60, the movable shaft 44 is in contact with the eccentric cam portion 48c and is the central axis of the protruding cylindrical surface 44b. It rotates counterclockwise around the center. For this reason, the lower end of the temperature compensation bimetal 42 moves to the right in the engagement elongated hole 36 of the shifter 34, and the reversal operation point of the reversal spring 60 according to the amount of deflection of the main bimetal 26 is changed. At this time, the projecting cylindrical surface 44b of the movable shaft is engaged with the engagement groove 48f formed in the eccentric cam portion 48c of the adjustment dial 48 as shown in FIG. Displacement can be reliably prevented.

If an abnormality occurs in the load or the like from the state where the main circuit is normal and the three-phase alternating current flowing through the main circuit becomes an overcurrent state, the three-phase alternating current is transferred to the heating element 32 of the thermal overload relay 10. Since these are individually supplied, these heating elements 32 are in a heat generating state.
For this reason, when the temperature of the main bimetal 26 rises, the upper end side of the main bimetal 26 is curved leftward from the state of FIG. In response to this, the shifter 34 moves to the left, and the lower end of the temperature compensation bimetal 42 is moved to the left. At this time, since the projecting cylindrical surface 44b of the projecting engagement portion 44c of the movable shaft 44 is engaged with the engagement groove 48f of the eccentric cam portion 48c of the adjustment dial 48, the movable shaft 44 rotates in the clockwise direction. Is done.

By the clockwise rotation of the movable shaft 44, the release lever 46 is also rotated clockwise, and the bending portion 82 of the reversing spring 60 is pressed to the left by the release lever 46.
In this way, when the bent portion 82 of the reversing spring 60 is pressed to the left, the outer leg 80 of the reversing spring 60 gradually begins to bend in the clockwise direction. Change.
As described above, when the reversing spring 60 is in the reversing state, the slider 66 slides to the right accordingly. As the slider 66 slides to the right, the movable contact spring 92 of the normally closed contact portion 62 bends counterclockwise, so that the contact 96 is disengaged from the fixed contact 94.

On the other hand, in the normally open contact portion 64, the movable contact spring 102 returns to the linear state from the counterclockwise bending state by sliding the slider 66 to the right, and the contact 106 comes into contact with the fixed contact 104. It becomes a closed state.
For this reason, a contact signal is supplied to the electromagnetic contactor constituting the main circuit, the electromagnetic contactor is controlled to be opened, and the supply of the three-phase alternating current to the load is interrupted.

As described above, the supply of the three-phase alternating current to the load is interrupted, and the supply of the three-phase alternating current to the heating element 32 of the thermal overload relay 10 is also stopped. Stopped. For this reason, the temperature of the main bimetal 26 falls, the amount of bending of the main bimetal 26 decreases, and it returns to the linear state shown in FIG. In response to this, the shifter 34 also returns to the right steady position.
At this time, the slider 66 has the left end of the reset hole 66a opposed to the left end side of the inclined surface 114 of the reset button 110 from above, as shown by the one-dot chain line in FIG.

When the abnormality of the load in the main circuit is resolved and the supply of the three-phase alternating current from the main circuit to the load is resumed, the reset button 110 is pressed downward against the return spring 112. Thereby, the inclined surface 114 of the reset button 110 is engaged with the left end of the reset hole 66 a of the slider 66, so that the slider 66 is slid leftward against the spring force of the reversing spring 60.
For this reason, when the tip of the reversing spring 60 is rotated counterclockwise and exceeds the dead point of the reversing spring 60, the reversing spring 60 is restored to the reset state shown by the solid line in FIG. To restore the reset position shown in the solid line.

At this time, in the normally closed contact portion 62, the movable contact spring 92 returns to a substantially linear state, and the contact 96 comes into contact with the fixed contact 94 to return to the normally closed state. At the same time, in the normally open contact portion 64, the movable contact spring 102 is rotated counterclockwise, so that the contact 106 is separated from the fixed contact 104 and returns to the normally open state.
As described above, according to the first embodiment, the deflection amount of the main bimetal 26 causes the movable shaft 44 to rotate via the temperature compensation bimetal 42, and the reversing spring 60 is rotated by the release lever 46 by the rotation of the movable shaft 44. Can be reversed.

  At this time, in the movable shaft 44, the protruding cylindrical surface 44 b formed in the protruding engaging portion 44 c is engaged with the engaging groove 48 f formed in the eccentric cam portion 48 c of the adjustment dial 48. Moreover, the back surface of the mounting plate portion 44 a of the movable shaft 44 is supported by a compression coil spring 50 disposed between the support piece 12 f formed on the upper surface plate 12 b of the outer case 12. For this reason, the movable shaft 44 is in a state in which the protruding cylindrical surface 44b is in contact with the engaging groove 48f of the eccentric cam portion 48c when the deflection amount of the main bimetal 26 is transmitted through the shifter 34 and the temperature compensation bimetal 42. Can be rotated. Therefore, when the movable shaft 44 is rotated, the movable shaft 44 is not shifted in the vertical direction, and the lever ratio of the release lever 46 is not changed by the movement of the movable shaft 44 in the vertical direction, so that the stable reversing operation is performed. Can be secured.

As a result, the movable shaft 44 can be reliably brought into contact with the eccentric cam portion 48 c of the adjustment dial 48 with a simple configuration in which the movable shaft 44 is simply pressed and held by the compression coil spring 50. Moreover, since a space portion can be provided below the adjustment dial 48, other components can be arranged in the space portion, and the efficiency of storing the components in the outer case 12 can be improved.
In the first embodiment, the case where the engaging groove 48f is formed in the eccentric cam portion 48c of the adjustment dial 48 has been described. However, the present invention is not limited to the above-described configuration, and a large downward force is not applied when the movable shaft 44 is rotated. Therefore, the directly engaging cylindrical surface 44b is omitted by omitting the engaging groove 48f. You may make it contact the eccentric cam part 48c.

Next, a second embodiment of the present invention will be described with reference to FIGS.
In the second embodiment, a tension coil spring is applied instead of the compression coil spring 50 to support the movable shaft 44.
That is, in the second embodiment, as shown in FIGS. 4 and 5, a pair of support pieces 120 projecting back and forth are disposed at the front and rear ends of the mounting plate portion 44 a of the movable shaft 44. A tension coil spring 122 having substantially the same spring load is disposed between the pair of support pieces 120 and the right side plate 12 d of the outer case 12.

  Thus, according to the second embodiment, the tension coil spring 122 is disposed between the pair of support pieces 120 formed on the mounting plate portion 44 a of the movable shaft 44 and the right side plate 12 d of the outer case 12. . For this reason, the movable coil 44 can be held by the tension coil spring 122 in a state in which the protruding cylindrical surface 44b is pressed against the eccentric cam portion 48c of the adjustment dial 48, which is the same as the first embodiment described above. Similar effects can be obtained.

Next, a third embodiment of the present invention will be described with reference to FIG.
In the third embodiment, the movable shaft is held by a link mechanism.
That is, in the third embodiment, as shown in FIG. 6, the link mechanism 130 that holds the movable shaft 44 is disposed on the lower surface of the support piece 12f in the first embodiment described above. The link mechanism 130 is disposed on the lower surface of the support piece 12f so as to be rotatable at a symmetrical position across a line L2 that is orthogonal to the support piece and passes through the central axis of the eccentric cam portion 48c of the adjustment dial 48. A pair of link members 132 is provided. Other link members 134 are rotatably connected to the other ends of the link members 132, and a support frame 136 that holds the movable shaft 44 rotatably is held at the free ends of the link members 134. A tension coil spring 138 is interposed between the pair of link members 132 to constitute a pantograph-like link mechanism.

  According to the third embodiment, the movable shaft is constituted by the two link members 132 and 134 provided symmetrically on the support piece 12f, the support frame 236, and the tension coil spring 138 disposed between the link members 132. 44 support members are formed. For this reason, when the pair of link members 132 are attracted to each other by the tension coil spring 138, the movable shaft 44 can be pressed into contact with the eccentric cam portion 48c of the adjustment dial 48, and the first and second implementations described above. The same effect as the form can be obtained.

  In the third embodiment, the case where the link mechanism is configured using the four link members 132 and 134 is described. However, the present invention is not limited to this, and as shown in FIG. A link mechanism can also be applied. That is, the two link members 142 and 144 are pivotally connected at the center thereof to form an X shape. For example, the rear end of one link member 142 is pivotally supported by the support piece 12f, and the front end is engaged with a support frame 146 that rotatably supports the movable shaft 44. The other link member 144 has a rear end pivotally supported on the support frame 146 and a front end engaged with the support piece 12f. Then, by inserting a tension coil spring 148 between the link members 142 and 144, the movable shaft 44 is pressed and brought into contact with the eccentric cam portion 48c of the adjustment dial 48 via the support frame 146. Also in this case, the same effects as those of the third embodiment described above can be obtained.

Next, a fourth embodiment of the present invention will be described with reference to FIGS.
In the fourth embodiment, the positional relationship between the movable shaft 44 and the adjustment dial 48 in the first embodiment described above is changed in the left-right direction.
That is, in the fourth embodiment, as shown in FIGS. 8 and 9, the adjustment dial 48 is rotatably disposed near the right end of the slider 66 at the reverse position of the contact opening / closing mechanism 40. The movable shaft 44 is in contact with the eccentric cam portion 48c of the adjustment dial 48 from the side opposite to the contact opening / closing mechanism 40, that is, from the right side. As shown in FIG. 9, the movable shaft 44 has a configuration in which the movable shaft 44 of the first embodiment described above is reversed left and right. This is omitted in the detailed description. The movable shaft 44 is supported while being pressed by a compression coil spring 150 as a support member in a state in which the protruding cylindrical surface 44 b of the movable shaft 44 is engaged with the engagement groove 48 f of the adjustment dial 48. That is, the compression coil spring 150 is interposed between the right end surface of the mounting plate portion 44a on the back side of the projecting cylindrical portion 44b of the movable shaft 44 and the support piece 12g formed to extend downward on the upper surface plate 12b of the outer case 12. Is arranged. For this reason, the projecting cylindrical surface 44b of the projecting engagement portion 44c is engaged with the engagement groove 48f formed in the eccentric cam portion 48c of the adjustment dial 48 while the movable shaft 44 is supported by the compression coil spring 50. Therefore, it is supported without moving up and down.

  According to the fourth embodiment, the movable shaft 44 is now in contact with the maximum diameter portion of the eccentric cam portion 48g of the adjustment dial 48. In this state, as shown by the solid line in FIG. 9, the lower end of the temperature compensation bimetal 42 is engaged with the axial center of the engagement long hole 36 of the shifter 34. For this reason, when the main bimetal 26 is bent in the left direction due to heat generation, it is necessary to bend a relatively large amount until the right end of the engagement long hole 36 of the shifter 34 contacts the right edge of the temperature compensation bimetal 42. .

  In this state, when the adjustment dial 48 is rotated to the minimum diameter portion side of the eccentric cam portion 48c, the movable shaft 44 is pressed and supported by the compression coil spring 150 toward the eccentric cam portion 48c. In response to the rotation, the movable shaft 44 moves to the left toward the reversing spring 60. At this time, since the release lever 46 is in contact with the operating portion 84 of the reversing spring 60, the movable shaft 44 rotates about the central axis of the protruding cylindrical surface 44b. For this reason, the lower end of the temperature compensation bimetal 46 approaches the right end side of the engaging long hole 36 of the shifter 34.

Therefore, the right end of the engagement elongated hole 36 of the shifter 34 is engaged with the temperature compensation bimetal 42 in a state where the curvature of the main bimetal 26 is small, and the same effect as that of the first embodiment described above is obtained. be able to.
Also in the fourth embodiment, the supporting mechanism shown in FIGS. 4, 5, 6, and 7 described above can be applied in place of the compression coil spring 150.

  Moreover, in the said 1st-4th embodiment, although the main bimetal 26 was placed vertically and the shifter 34 was arrange | positioned so that sliding to the left-right direction was carried out at the upper end, this invention has the said structure. It is not limited. That is, as schematically shown in FIG. 10, the main bimetal 26 is disposed horizontally in the front-rear direction, the shifter 34 is slidably engaged with the rear end side, and extends upwardly formed on the shifter 34. The temperature compensating bimetal 42 may be moved by the pressing piece 34a.

  Further, in the first to fourth embodiments, the case where the reversing spring 60 has the bent portion 82 in the central leg portion 78 has been described. However, the present invention is not limited to this, and a pair of outer sides are provided. You may make it form a bending process part in the leg part 80. FIG. Furthermore, as described in JP-A-2-86024, a central leg is formed by punching a rectangular thin leaf spring material, and a hole that is caulked and fixed to a support piece on one end side of both side legs is provided. By providing the holes on both side legs close to each other in the same plane and contracting in the width direction, a disc spring-like curved surface is formed on both side legs, and the tip of the other end of each side leg is set to the slider 66. The center leg portion may be configured as a reverse operation portion. In addition, a reversing spring having an arbitrary shape can be applied.

It is a block diagram which shows the 1st Embodiment of this invention. It is an enlarged view of the movable shaft periphery part in FIG. It is a perspective view which shows the inversion spring of FIG. It is an enlarged view similar to FIG. 2 which shows the 2nd Embodiment of this invention. It is the sectional view on the AA line of FIG. It is sectional drawing similar to FIG. 5 which shows the 3rd Embodiment of this invention. It is sectional drawing similar to FIG. 6 which shows the modification of 3rd Embodiment. It is sectional drawing similar to FIG. 1 which shows the 4th Embodiment of this invention. It is an enlarged view of the movable shaft periphery part in FIG. It is a schematic diagram which shows the other example of arrangement | positioning of the main bimetal. It is a block diagram which shows a prior art example.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Thermal overload relay, 12 ... Outer case, 20 ... Actuator mechanism, 22 ... Bimetal unit, 26 ... Main bimetal, 32 ... Heating element, 34 ... Shifter, 40 ... Contact switching mechanism, 42 ... Temperature adjustment bimetal, 44 ... movable shaft 44a ... mounting plate portion 44b ... projecting cylindrical surface 44c ... projecting engagement portion 46 ... release lever 48 ... adjusting dial 48c ... eccentric cam portion 50 ... compression coil spring 60 ... reverse Spring, 62 ... Normally closed contact portion, 64 ... Normally open contact portion, 66 ... Slider, 110 ... Reset button, 120 ... Supporting piece, 122 ... Tension coil spring, 130 ... Link mechanism, 132, 134 ... Link member, 136 ... Tension coil spring, 142, 144 ... link member, 146 ... support frame, 148 ... tension coil spring, 150 ... compression coil spring

Claims (8)

  A bimetal that is bent by energization of an overcurrent of the main circuit in the outer case, a shifter that is displaced according to the bending of the bimetal, a release lever that is driven by the displacement of the shifter, and the main circuit that is driven by the release lever A contact opening / closing mechanism that opens and closes a contact point with respect to, a movable shaft that holds the release lever, and an adjustment mechanism that adjusts a settling current by setting a movable position of the movable shaft in a predetermined direction by contacting the movable shaft; A thermal overload relay, comprising: a support member that linearly presses and supports the movable shaft in the predetermined direction so as to contact the adjusting mechanism.   2. The thermal overload relay according to claim 1, wherein the movable shaft is disposed so as to come into contact with the adjustment mechanism from the contact opening / closing mechanism side.   2. The thermal overload relay according to claim 1, wherein the movable shaft is disposed so as to contact the adjustment mechanism from a side opposite to the contact opening / closing mechanism.   The thermal overload relay according to any one of claims 1 to 3, wherein the support member is configured by a compression spring that supports the movable shaft by pressing it toward the adjustment mechanism. .   The thermal overload relay according to any one of claims 1 to 3, wherein the support member is configured by a tension spring that presses and supports the movable shaft toward the adjustment mechanism. .   The thermal overload relay according to any one of claims 1 to 3, wherein the support member is configured by a link mechanism that supports the movable shaft by pressing the movable shaft toward the adjustment mechanism. .   The thermal overload relay according to claim 6, wherein the link mechanism is a pantograph type link mechanism.   A contact surface of the movable shaft with the adjustment mechanism is formed on a protruding cylindrical surface, and the adjustment dial extends in a circumferential direction engaging with the protruding cylindrical surface at a position engaging with the protruding cylindrical surface of the movable shaft. The thermal overload relay according to any one of claims 1 to 7, wherein a combined recess is formed.

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