JP2011165492A - Thermal overload relay - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thermal overload relay capable of stabilizing operation characteristics of a pushing shifter, a pull shifter, and a differential lever on the occurrence of an overload current or occurrence of phase interruption and transmitting bending displacement of a bimetal efficiently to a contact mechanism. <P>SOLUTION: Slits for shifter sliding 10a, 15a, 16a are formed in a housing space partition 10 and bimetal partitions 15, 16, and the pushing shifter 7 and the pull shifter 8 are inserted into these slits for shifter sliding. Guiding long holes 22, 23, 30, 31 which extend in straight line shape along the bending displacement direction X are formed respectively in the pushing shifter and the pull shifter. Engaging protrusions 24, 25, 32, 33 which are engaged with the inner wall in major axis direction of guiding long holes 22, 23, 30, 31 are formed on the slit face of the slits for shifter sliding 15a, 16a of the bimetal partitions. These guiding long holes and engaging protrusions are used as a shifter displacement guide to displace the pushing shifter and the pull shifter. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a thermal overload relay that performs overcurrent protection and phase loss protection for an electric motor or the like.

For example, the apparatus of Patent Document 1 is known as a thermal overload relay that is used together with a circuit breaker for wiring, an electromagnetic contactor, and the like and performs overcurrent protection and phase loss protection for an electric motor or the like.
The thermal overload relay of Patent Document 1 includes a heater composed of a plurality of bimetals arranged in a line in the case with the curved displacement directions coincided with each other at the time of temperature rise, and a heater element wound around each bimetal, A differential shifter mechanism, a contact mechanism that opens and closes a contact, and a contact opening and closing mechanism that opens and closes the contact mechanism in conjunction with the differential shifter mechanism are housed.
The differential shifter mechanism includes a flat plate-like push shifter and pull shifter that follow the bimetal bending displacement, and a differential lever that engages with the push shifter and pull shifter and interlocks the contact opening / closing mechanism.

The push shifter has a surface direction extending in a direction perpendicular to the direction in which the bimetal extends, and engages with one surface of the bending displacement direction of each bimetal, and is arranged so as to be displaced substantially along the bending displacement direction. Has been. The pull shifter is disposed in the same plane as the push shifter (the thickness direction is disposed in the same plane as the push shifter) and engages with the other surface of the plurality of bimetals in the bending displacement direction. It is possible to displace substantially along.
The heater is housed in a first housing space provided in the case, and the contact opening / closing mechanism is housed in a second housing space provided in the case adjacent to the first housing space, and a push shifter of the differential shifter mechanism, The pulling shifter and the differential lever are housed in a position straddling the first and second housing spaces, and the differential lever directly interlocks the contact opening / closing mechanism.

  When an overload current flows through the main circuit, the thermal overload relay with the above configuration is displaced by the displacement of the push shifter due to the bending displacement of multiple bimetals due to the heat generated by the heater element, and thereby the differential lever is displaced. The pull shifter is displaced together with the push shifter and the differential lever. When the differential lever is displaced, the contact opening / closing mechanism interlocks to switch the contact of the contact mechanism. In addition, when a phase failure occurs, the bimetal that does not bend and bend in the phase where the phase failure occurs pulls to restrict the shift of the shifter, and the push shifter is displaced in the same manner as when an overload current flows. In this way, the difference between the displacement amounts of the push shifter and the pull shifter causes the differential lever to be greatly displaced, and the contact opening / closing mechanism is linked earlier than when the overload current flows, and the contact of the contact mechanism is switched. .

Japanese Patent Publication No.59-21134

By the way, the push shifter and the pull shifter are arranged so that the thickness direction is on the same plane, but the direction in which the push shifter and the pull shifter are orthogonal to the direction along the bending displacement direction of the bimetal on the plane is bimetal. And the displacement is not regulated (hereinafter, the direction orthogonal to the direction along the bending displacement direction is referred to as a non-regulated direction). In other words, the push shifter and the pull shifter are supported by the non-regulated direction peripheral edge only in contact with the inner wall of the case, so the backlash in the non-regulated direction is large and the bimetal is bent and deformed and pressed. The shifter and the pull shifter may be displaced in a non-regulating direction. Therefore, there is a problem that when the overload current is generated and the phase loss occurs, the displacement amount of the push shifter and the pull shifter in the bending displacement direction becomes small, and the operation characteristics of the differential shifter mechanism are not stable.
Therefore, the present invention stabilizes the operating characteristics of the differential shifter mechanism (push shifter, pulling shifter and differential lever) when an overload current occurs or when a phase loss occurs, and makes the bimetal bending displacement an efficient contact mechanism. It is intended to provide a thermal overload relay that can transmit.

  In order to achieve the above object, a thermal overload relay according to the present invention includes a first storage space and a second storage space that are provided adjacent to each other with a storage space partition wall in the case, and a temperature rise. A plurality of bimetals arranged in a row in the first storage space in such a manner that the bending displacement direction at the time coincides with the second storage space, and provided in the first storage space in parallel with the storage space partition wall A plurality of bimetal partition walls that individually store the plurality of bimetals, a contact opening / closing mechanism that is disposed in the second storage space and performs an opening / closing operation of the contact mechanism, and is disposed so that the thickness direction is on the same plane, A flat push shifter and pull shifter that engage with the free ends of the plurality of bimetals and extend over the first storage space and the second storage space, and the push shifter and the pull shifter The second of A differential lever engaged with a portion located in the storage space, and when the push shifter and the pull shifter are displaced by the bending displacement of the plurality of bimetals and the differential lever is driven, In the thermal overload relay in which the displacement is directly transmitted to the transmission member of the contact opening / closing mechanism, a shifter displacement guide portion for supporting the push shifter and the pull shifter so as to be linearly displaced is provided. This is a thermal overload relay characterized by

  According to the present invention, the displacement of the push shifter and the pull shifter other than the direction along the bending displacement direction is regulated by the shifter displacement guide portion, and the operation characteristics of the push shifter, the pull shifter, and the differential lever can be stabilized. It becomes possible to efficiently transmit the bending displacement of the bimetal when an overload current is generated or when a phase failure occurs to the contact mechanism.

  According to a second aspect of the present invention, in the thermal overload relay according to the first aspect, a shifter sliding slit is formed in each of the storage space partition wall and the plurality of bimetal partition walls, and the shifter sliding The push shifter and the pull shifter are inserted into the slit, and the shifter displacement guide portion is formed in each of the push shifter and the pull shifter and extends in a straight line along the curved displacement direction. It is formed on the slit surface of the slit for sliding the shifter formed in the guide long hole and the plurality of bimetal partition walls, and engages and enters the inner wall in the long axis direction of the guide long hole of the push shifter and the pull shifter. An engaging protrusion, and the push shifter and the inner surface of the engaging protrusion and the inner wall in the long axis direction of the guide elongated hole slide while sliding. Can shifter has to be displaced.

  According to this invention, as the shifter displacement guide portion, the guide elongated holes formed in each of the push shifter and the pull shifter and the engagement protrusions formed on the slit surfaces of the shifter sliding slits of the plurality of bimetal partition walls slide relative to each other. As a result, when the overload current is generated or when the phase loss occurs, the push shifter and the pull shifter are rotated and the displacement amount in the bending displacement direction is reliably reduced.

  According to a third aspect of the present invention, in the thermal overload relay according to the first aspect, a shifter sliding slit is formed in each of the storage space partition wall and the plurality of bimetal partition walls, and the shifter sliding The push shifter and the pull shifter are inserted into the slit, and the shifter displacement guide portion is formed in each of the push shifter and the pull shifter and extends in a straight line along the bending displacement direction. Formed on the slit surface of the shifter sliding slit formed on the bimetal partition wall that is the farthest apart from the elongated hole, the slit for sliding the storage space formed on the partition wall and the storage space partition wall, and An engagement protrusion that engages and enters the inner wall in the long axis direction of the guide elongated hole of the shifter and the pulling shifter, and The push shifter and the pull shifter is so displaced peripheral surface and the long axis direction of the inner wall of the guide slot of the projection while sliding.

  According to the present invention, as the shifter displacement guide portion, the guide long hole formed in each of the push shifter and the pull shifter, the shifter sliding slit formed in the storage space partition wall, and the bimetal partition farthest from the storage space partition wall A bimetal partition wall that is spaced apart from the slit surface of the storage space partition wall and the storage space partition wall so that the engagement protrusions formed on the slit surface of the slit for sliding the shifter formed on the wall slide with each other By using this slit surface, the pitch for supporting the push shifter and the pull shifter is set longer than in the invention of claim 2, and the push shifter and the pull shifter are further displaced linearly. Can do.

  According to the thermal overload relay according to the present invention, the displacement of the push shifter and the pull shifter other than the direction along the bending displacement direction is regulated by the shifter displacement guide portion, and when an overload current is generated or an open phase is generated. Since the push shifter and pull shifter rotate and the displacement in the bending displacement direction is reduced, the operating characteristics of the push shifter, pull shifter and differential lever can be stabilized, and overload current is generated. It is possible to efficiently transmit the bending displacement of the bimetal at the time of occurrence of phase failure or phase failure to the contact mechanism.

It is a perspective view which shows the internal structure of the thermal overload relay which concerns on this invention. It is the figure which showed the push shifter and pulling shifter of 1st Embodiment which concern on this invention, and the structure which supports these from the attachment side. It is the figure which showed from the attachment side the structure which supports the push shifter and pulling shifter of 2nd Embodiment which concern on this invention, and these. It is AA arrow sectional drawing of FIG.

DESCRIPTION OF EMBODIMENTS Hereinafter, modes for carrying out the present invention (hereinafter referred to as embodiments) will be described in detail with reference to the drawings.
The thermal overload relay 1 shown in FIG. 1 controls a three-phase AC main circuit, opens and closes contacts when an overload current is generated and when a phase loss occurs, and an electromagnetic contactor, etc. Is a device for operating the circuit breaking means.
As shown in FIG. 1, the thermal overload relay 1 of this embodiment includes a heater 3, a differential shifter mechanism 4, a contact mechanism 5, and a contact opening / closing mechanism 6 in a case 2. The shifter mechanism 4 includes a flat push shifter 7, a pull shifter 8, and a differential lever 9.

The case 2 is, for example, a resin injection molded product, and a contact mechanism 5 is accommodated in an upper portion of the case 2 in FIG.
The contact mechanism 5 opens and closes a contact during overload protection or phase loss protection, and is connected to a circuit breaker such as an electromagnetic contactor (not shown).
The case 2 is provided with a partition wall 10 that partitions the internal space between the contact mechanism 5 and the lower mounting plate 2a in FIG. 1 into the left and right spaces in FIG. 1, and the right space in FIG. A storage space 11 is provided, and a space on the left side in FIG. 1 is a second storage space 12. A slit 10a is formed in the partition wall 10 in the vicinity of the mounting plate 2a.

The first storage space 11 stores the heater 3, and the second storage space 12 stores the contact opening / closing mechanism 6.
The heater 3 is provided corresponding to each phase of three-phase alternating currents R, S, and T, and is composed of three bimetals that are strip-shaped members in which a pair of metal plates having different thermal expansion coefficients are joined in layers. 12R, 12S, and 12T and heater elements 13R, 13S, and 13T that are resistance wires wound around the bimetals 12R, 12S, and 12T, respectively, and when heated to the heater elements 13R, 13S, and 13T, the bimetal 12R, 12S, and 12T are curvedly displaced.

  In the first storage space 11, in order to store the three bimetals 12R, 12S, and 12T individually in the left-right direction in FIG. 1, two bimetal partition walls 15 that extend in the vertical direction in FIG. , 16 are formed, and slits 15a, 16a are formed in the vicinity of the mounting plate 2a of these bimetal partition walls 15, 16. The bimetals 12R, 12S, and 12T are arranged substantially in parallel and at equal intervals in a space between the bimetal partition walls 15 and 16, the partition wall 10, and the side wall of the case 2, and one end portion (the upper end portion in FIG. 1). Is fixed to the case 2 via the support bracket 17, and the other free end (the lower end in FIG. 1) is engaged with the push shifter 7 and the pull shifter 8 of the differential shifter mechanism 4. .

The arrangement direction of the bimetals 12R, 12S, and 12T is the left-right direction in FIG. 1 that substantially matches the thickness direction thereof, and the bending displacement direction of the bimetals 12R, 12S, and 12T coincides with the arrangement direction.
The push shifter 7 and the pull shifter 8 of the differential shifter mechanism 4 are slidably disposed in the slits 15a and 16a provided in the bimetal partition walls 15 and 16 and the slit 10a provided in the partition wall 10 so as to be slidable. The differential shifter mechanism 4 straddles the first storage space 11 and the second storage space 12 by engaging the four differential levers 9 with the push shifter 7 and the pull shifter 8 positioned in the second storage space 12. It is housed in the case 2 along the mounting plate 2a while being bent.

The contact opening / closing mechanism 6 is a transmission mechanism that opens and closes the contact of the contact mechanism 5 in conjunction with the differential shifter mechanism 4, and includes a compensation bimetal 6 a that is directly pressed by the differential lever 9 of the differential shifter mechanism 4. ing.
FIG. 2 shows a push shifter 7, a pull shifter 8 and a differential lever 9 constituting the differential shifter mechanism 4 according to the first embodiment of the present invention. In FIG. 2, a rectangular space surrounded by a broken line is a first storage space 11, and a rectangular space surrounded by a one-dot chain line is a second storage space 12.

  The push shifter 7 and the pull shifter 8 of this embodiment are arranged so that the surface direction extends in a direction orthogonal to the extending direction of the bimetals 12R, 12S, and 12T of each phase, and the thickness direction is the same plane. It is a plate-like member. Further, the arrow X direction and the arrow Y direction in FIG. 2 are directions extending on the same plane where the push shifter 7 and the pull shifter 8 are arranged, and the arrow X direction indicates that the bimetals 12R, 12S, and 12T of each phase are Direction of bending displacement (hereinafter referred to as bending displacement direction X).

  The push shifter 7 is arranged to extend from the first storage space 11 to the second storage space 12, and has a belt-like portion 18 that slides on the slits 15 a and 16 a of the bimetal partition walls 15 and 16 and the slit 10 a of the partition wall 10. The arm portions 19R, 19S, and 19T formed from the side edge portions of the belt-shaped portion 18 are formed on the arm portions 19R, 19S, and 19T, and the bimetals 12R, 12S, and 12T of each phase are heated. The contact portions 20R, 20S, and 20T that are pressed when bent and displaced, and the arm portion 19T that is provided on the compensation bimetal 6a side of the contact opening / closing mechanism 6 and that protrudes in the bending displacement direction X This is a member provided with a portion 21.

  In addition, two guide long holes 22 and 23 are formed in the belt-like portion 18 at portions that slide on the slits 15 a and 16 a of the bimetal partition walls 15 and 16. These guide elongated holes 22 and 23 are elongated holes extending linearly along the bending displacement direction X. And the engagement protrusions 24 and 25 which protrude from the slit surface of the slits 15a and 16a formed in the bimetal partition walls 15 and 16 enter into these two guide long holes 22 and 23, respectively. The engagement protrusions 24 and 25 are arranged so that the peripheral surfaces of the engagement protrusions 24 and 25 are slidable on the inner walls of the guide long holes 22 and 23 in the long axis direction. It is formed in a cylindrical shape having an outer diameter dimension substantially the same as the width in the direction.

  The pull shifter 8 extends from the first storage space 11 to the second storage space 12, and is arranged in a strip-like portion 26 that slides in the slits 15a, 16a and the slit 10a, and a side edge portion of the strip-like portion 26. Abutting portions 28R, 28S that abut against the opposite sides of the three arm portions 27R, 27S, 27T formed by protruding from the direction of bending and displacement of the bimetals 12R, 12S, 12T of each phase by heating. , 28T and a pin insertion hole 29 formed in a portion of the belt-like portion 26 located in the second storage space 12.

  In the belt-like portion 26, two guide long holes 30 and 31 are formed at portions that slide in the slits 15a and 16a. These guide elongated holes 30 and 31 are elongated holes extending linearly along the bending displacement direction X. And the engagement protrusions 32 and 33 which protrude from the slit surface of the slits 15a and 16a have entered into these two guide long holes 30 and 31, respectively. The engagement protrusions 32 and 33 are arranged so that the peripheral surfaces of the engagement protrusions 32 and 33 are slidable on the inner walls of the guide long holes 30 and 31 in the long axis direction. It is formed in a cylindrical shape having an outer diameter dimension substantially the same as the width in the direction.

On the other hand, the differential lever 9 is a plate-like member arranged along a direction Y orthogonal to the bending displacement direction X, a rotation pin 34 is formed on one end side, and a compensation bimetal of the contact opening / closing mechanism 6 on the other end side. A pressing portion 35 that contacts 6 a is formed, and a contact wall 9 a that contacts the pressing portion 21 of the push shifter 7 is formed between the rotating pin 34 and the pressing portion 35.
The differential lever 9 is connected to the pull shifter 8 so as to be rotatable about the rotation pin 34 by inserting the rotation pin 34 into the pin insertion hole 29 of the pull shifter 8.

Next, the operation of the differential shifter mechanism 4 of this embodiment will be described.
First, in a state where no phase failure occurs, the bimetals 12R, 12S, and 12T of each phase are heated substantially evenly by the heater elements 13R, 13S, and 13T through which the main circuit current flows. This heating causes bending displacement of the bimetals 12R, 12S, and 12T, and their free ends are displaced in the bending displacement direction X shown in FIG. As a result, the contact portions 20R, 20S, 20T of the push shifter 7 are pushed by the free ends of the bimetals 12R, 12S, 12T, and the push shifter 7 is displaced toward the compensating bimetal 6a. This displacement amount substantially coincides with the bending displacement amount of the bimetal 12R, 12S, 12T. At this time, the pull shifter 8 follows the push shifter 7 and is displaced toward the compensation bimetal 6a. As a result, the differential lever 9 also translates toward the compensation bimetal 6a.

  When an overload current is passed through the main circuit in a state where no phase loss has occurred, the temperatures of the bimetals 12R, 12S, and 12T are higher than those during normal use, and the bending displacement increases. As a result, the displacement amount of the push shifter 7, the pull shifter 8, and the differential lever 9 toward the compensation bimetal 6a increases, and the pressing portion 35 of the differential lever 9 presses the compensation bimetal 6a. The signal is transmitted to the contact mechanism 5 through the mechanism 6, and the contact is opened and closed to protect the circuit.

  Next, the operation when a phase failure occurs will be described. Here, as an example, a case where the R phase is lost will be described. When the R phase is lost, the corresponding bimetal 12R is not heated with respect to the other bimetals 12S and 12T and becomes a low temperature, so that no bending displacement occurs or even if a bending displacement occurs, the other bimetals 12S and 12T On the other hand, it becomes smaller. When the bending displacement amounts of the bimetals 12R, 12S, and 12T change for each phase in this way, the push shifter 7 is displaced toward the compensation bimetal 6a by the displacement amount of the bimetals 12S and 12T having the largest bending displacement, but the pulling shifter 8 Only the displacement amount of the bimetal 12R having the smallest bending displacement is displaced, and the displacement amount of the push shifter 7 and the pull shifter 8 is different. When such a differential occurs, the differential lever 9 rotates about the rotation pin 34 counterclockwise in FIG. Due to this rotation, the displacement amount of the pressing portion 35 of the differential lever 9 becomes larger than the displacement amount of the push shifter 7, and when a phase failure occurs, the contact opening / closing mechanism is earlier than when an overload current flows. 6 operates, and circuit protection works even when the current is relatively small as compared with the case where no phase loss occurs.

  Here, in the present embodiment, two elongated guide holes 22 and 23 extending linearly along the bending displacement direction X are formed in the belt-like portion 18 of the push shifter 7. When displacing to the compensation bimetal 6a side, the two guide elongated holes 22 and 23 continue to engage with the engagement protrusions 24 and 25 protruding from the slits 15a and 16a of the bimetal partition walls 15 and 16. The strip-like portion 26 of the pull shifter 8 is also formed with two guide slots 30 and 31 extending linearly along the bending displacement direction X, and the pull shifter 8 is displaced toward the compensation bimetal 6a. In doing so, the two guide slots 30 and 31 continue to engage with the engaging protrusions 32 and 33 protruding from the slits 15a and 16a of the bimetal partition walls 15 and 16, respectively.

As described above, the push shifter 7 is restricted from being displaced in the direction Y perpendicular to the bending displacement direction X (the bending displacement direction X) by the engagement of the guide slots 22 and 23 and the engagement protrusions 24 and 25. Other displacements are regulated). In addition, the displacement of the pull shifter 8 in the direction Y perpendicular to the bending displacement direction X is regulated by engaging the guide elongated holes 30 and 31 and the engaging protrusions 32 and 33 (other than the bending displacement direction X). Displacement is regulated). Accordingly, when the overload current is generated or when the phase loss occurs, the push shifter 7 and the pull shifter 8 are prevented from rotating and the displacement amount in the bending displacement direction X is reduced. The operating characteristics can be stabilized.
Therefore, the present embodiment can stabilize the operation characteristics of the differential shifter mechanism 4, so that the bending displacement of the bimetals 12R, 12S, and 12T when an overload current occurs or when a phase loss occurs can be efficiently performed. It is possible to provide a thermal overload relay 1 that can be transmitted to

Next, FIGS. 3 and 4 show a differential shifter mechanism 4 according to a second embodiment of the present invention. Note that the same components as those shown in FIG. 2 are denoted by the same reference numerals and description thereof is omitted.
The differential shifter mechanism 4 of this embodiment is composed of a push shifter 7 and a pull shifter 8 and a differential lever 36 having substantially the same shape as that shown in FIG. 2, and the push shifter 7 and the pull shifter 8 are The surface directions extend in the direction orthogonal to the extending direction of the bimetals 12R, 12S, and 12T of the respective phases, and are arranged on the same plane.

  The push shifter 7 of the present embodiment does not have the guide elongated hole 23 formed in the portion that slides on the slit 16a of the bimetal partition wall 16 of the belt-like portion 18 shown in FIG. 2, and instead, as shown in FIG. In addition, a guide slot 37 extending linearly along the bending displacement direction X is formed in a portion that slides on the slit 10 a of the partition wall 10. An engagement protrusion 38 protruding from the slit surface of the slit 10 a of the partition wall 10 enters the guide long hole 37, and the protrusion peripheral surface of the engagement protrusion 38 is in the long axis direction of the guide long hole 37. In order to be slidable on the inner wall, the guide elongated hole 37 is formed in a cylindrical shape having substantially the same outer diameter as the width in the minor axis direction.

  Further, the pull shifter 8 does not have the guide long hole 23 formed in the portion that slides on the slit 16a of the bimetal partition wall 16 of the strip-like portion 26 shown in FIG. 2, and instead, as shown in FIG. A guide elongated hole 39 extending linearly along the bending displacement direction X is formed in a portion that slides on the slit 10 a of the partition wall 10. An engagement protrusion 40 protruding from the slit surface of the slit 10 a of the partition wall 10 enters the guide long hole 39, and the protrusion peripheral surface of the engagement protrusion 40 has a long axis direction of the guide long hole 39. In order to be slidable on the inner wall, the guide elongated hole 39 is formed in a cylindrical shape having substantially the same outer diameter as the width in the minor axis direction.

  The differential lever 36 of the present embodiment is a member arranged along a direction Y orthogonal to the bending displacement direction X, and a pair of clamping plate portions 41 and 42 are formed on one end side (see FIG. 4). The pin 43 is formed so as to protrude from the holding plate 41, and a pressing portion 44 that contacts the compensation bimetal 6 a of the contact opening / closing mechanism 6 is formed on the other end side. A pair of the holding plate portions 41, 42 and the pressing portion 44 are formed. In between, the contact wall 45 with which the press part 21 of the push shifter 7 contacts is formed.

  The pair of sandwiching plate portions 41 and 42 is a member for sandwiching the front and back surfaces on one end side of the belt-like portion 26 of the pulling shifter 8 located in the second storage space. As shown in FIG. By inserting the rotating pin 43 into the pin insertion hole 29 of the pulling shifter 8 into the rotating pin 43 protruding from the differential lever 36, the differential lever 36 can be rotated around the rotating pin 43 as the rotation center. It is connected to.

  Here, in order to insert the rotary pin 43 into the pin insertion hole 29, first, the position where the other clamping plate portion 42 does not contact the surface of the pull shifter 8, that is, the differential lever 36 in FIG. In this state, the rotary pin 43 is pulled and inserted into the pin insertion hole 29 of the shifter 8, and then the differential lever 36 is rotated approximately 180 ° clockwise around the rotary pin 43. Perform the action.

Next, the operation of the differential shifter mechanism 4 of this embodiment will be described.
If an overload current is passed through the main circuit in a state where no phase failure occurs, the temperatures of the bimetals 12R, 12S, and 12T rise higher than in normal use, and the bending displacement increases, and the push shifter 7 and the pull shifter 8 The amount of displacement of the differential lever 36 toward the compensation bimetal 6a increases, the pressing portion 44 of the differential lever 36 presses the compensation bimetal 6a, and this pressing force is transmitted to the contact mechanism 5 via the contact opening / closing mechanism 6. The contacts are opened and closed to protect the circuit.

  Further, when an open phase occurs (for example, when the R phase is lost), the push shifter 7 is displaced toward the compensating bimetal 6a by the displacement amount of the bimetals 12S and 12T having the largest bending displacement. The shifter 8 is displaced only by the displacement amount of the bimetal 12R having the smallest bending displacement, and there is a difference between the displacement amounts of the push shifter 7 and the pull shifter 8. Due to such a differential, the differential lever 36 rotates about the rotation pin 43 counterclockwise in FIG. Due to this rotation, the displacement amount of the pressing portion 44 of the differential lever 36 becomes larger than the displacement amount of the push shifter 7, and when a phase failure occurs, the contact opening / closing mechanism is earlier than when an overload current flows. 6 operates, and circuit protection works even when the current is relatively small as compared with the case where no phase loss occurs.

  Here, in this embodiment, in the strip-like portion 18 of the push shifter 7, two guide elongated holes having a longer distance from each other than the two guide elongated holes 22 and 23 shown in the first embodiment. 22 and 37 are formed, and when the push shifter 7 is displaced toward the compensating bimetal 6a, the two guide elongated holes 22 and 37 are engaged with the engaging protrusions 24 protruding from the slits 15a of the bimetal partition wall 15. The engagement with the engagement protrusion 38 protruding from the slit 10a of the partition wall 10 is continued.

  In addition, the strip-like portion 26 of the pull shifter 8 of the present embodiment also has two guide slots 30 that are longer in distance from each other than the two guide slots 30 and 31 shown in the first embodiment. When the pull shifter 8 is displaced to the compensation bimetal 6a side, the two guide slots 30 and 39 are provided with the engagement protrusion 32 protruding from the slit 15a of the bimetal partition wall 15 and the partition. It continues to engage with the engaging protrusion 40 protruding from the slit 10a of the wall 10.

  As described above, the push shifter 7 of this embodiment restricts displacement in the direction Y perpendicular to the bending displacement direction X by the guide elongated holes 22 and 37 and the engagement protrusions 24 and 38, as compared with the first embodiment. The regulation pitch for regulating (regulating the displacement other than the bending displacement direction X) is set longer, and the pull shifter 8 is also provided with the guide elongated holes 30, 39 and the engagement projections 32, compared with the first embodiment. Since the restriction pitch for restricting the displacement in the direction Y orthogonal to the bending displacement direction X by 40 is set long (displacement other than the bending displacement direction X), the displacement of the push shifter 7 and the pulling shifter 8 The direction is almost a linear direction along the bending displacement direction X.

Therefore, in this embodiment, when the overload current is generated or when the phase loss occurs, the displacement direction of the push shifter 7 and the pull shifter 8 is a linear direction along the bending displacement direction X. The characteristics can be further stabilized.
In addition, since the operation characteristics of the differential shifter mechanism 4 can be further stabilized in this embodiment, the bending displacement of the bimetals 12R, 12S, and 12T when an overload current is generated or when a phase loss occurs can be more efficiently contacted. A thermal overload relay 1 that can be transmitted to the mechanism 5 can be provided.

  DESCRIPTION OF SYMBOLS 1 ... Thermal overload relay, 2 ... Case, 2a ... Mounting plate, 3 ... Heater, 4 ... Differential shifter mechanism, 5 ... Contact mechanism, 6 ... Contact switching mechanism, 6a ... Compensation bimetal (transmission member), 7 DESCRIPTION OF SYMBOLS ... Push shifter, 8 ... Pull shifter, 9 ... Differential lever, 9a ... Contact wall, 10 ... Partition wall (storage space partition wall), 10a ... Slit (shifter sliding slit), 11 ... First storage space, 12 ... 2nd storage space, 12R, 12S, 12T ... Bimetal, 13R, 13S, 13T ... Heater element, 15, 16 ... Bimetal partition wall, 15a, 16a ... Slit (shifter sliding slit), 17 ... Support bracket, 18 ... Push-shifter strips, 19R, 19S, 19T ... push-shifter arms, 20R, 20S, 20T ... push-shifter contact parts, 21 ... push-shifter press parts, 22, 23 ... push-shifter Guide long holes, 24, 25 ... engaging projections, 26 ... strip-like portions of the pull shifter, 27R, 27S, 27T ... arm portions of the pull shifter, 28R, 28S, 28T ... contact portions of the pull shifter, 29 ... pin insertion holes , 30 ... guide slot, 30, 31 ... guide slot in the pull shifter, 32, 33 ... engagement projection, 34 ... rotating pin, 35 ... pressing part of the pull shifter, 36 ... differential lever, 37 ... push shifter Guide slot 38, engagement projection 39, guide shift hole of pull shifter 40, engagement projection 41, 42 pinching plate portion 43 rotation pin 44 pressing portion 45 contact wall X ... curvature displacement direction, Y ... direction perpendicular to the curvature displacement direction

Claims (3)

The first storage space and the second storage space that are provided adjacent to each other with a storage space partition wall in the case are aligned with the second storage space so that the bending displacement direction at the time of temperature rise faces the second storage space. A plurality of bimetals arranged in a row in one storage space; a plurality of bimetal partition walls provided in the first storage space in parallel with the storage space partition wall; and storing the plurality of bimetals individually; The contact opening / closing mechanism disposed in the storage space and opening / closing operation of the contact mechanism is disposed so that the thickness direction is on the same plane, and is engaged with the free ends of the plurality of bimetals, and the first storage space and the A flat push shifter and a pull shifter extending while straddling the second storage space, and a differential lever engaged with a portion of the push shifter and the pull shifter located in the second storage space. Comprising When the push shifter and the pull shifter are displaced by the bending displacement of the bimetal and the differential lever is driven, the displacement of the differential lever is directly transmitted to the transmission member of the contact opening / closing mechanism. In overload relay,
A thermal overload relay comprising a shifter displacement guide portion for supporting the push shifter and the pull shifter so as to be displaced linearly. A shifter sliding slit is formed in each of the storage space partition wall and the plurality of bimetal partition walls, and the push shifter and the pull shifter are inserted into these shifter sliding slits,
As the shifter displacement guide portion, at least two guide slots formed in each of the push shifter and the pull shifter and extending linearly along the curved displacement direction,
An engagement protrusion formed on a slit surface of the shifter sliding slit formed on the plurality of bimetal partition walls, and engaging with and entering an inner wall in a long axis direction of the guide elongated hole of the push shifter and the pull shifter; Provided,
2. The thermal overload relay according to claim 1, wherein the push shifter and the pull shifter are displaced while the peripheral surface of the engagement protrusion and the inner wall in the long axis direction of the guide elongated hole slide. A shifter sliding slit is formed in each of the storage space partition wall and the plurality of bimetal partition walls, and the push shifter and the pull shifter are inserted into these shifter sliding slits,
As the shifter displacement guide portion, two guide elongated holes formed in each of the push shifter and the pull shifter and extending linearly along the curved displacement direction,
The shifter sliding slit formed in the storage space partition wall and the slit surface of the shifter sliding slit formed in the bimetal partition wall farthest from the storage space partition wall, the push shifter and the pull An engagement protrusion that engages and enters the inner wall in the long axis direction of the guide elongated hole of the shifter, and
2. The thermal overload relay according to claim 1, wherein the push shifter and the pull shifter are displaced while the peripheral surface of the engagement protrusion and the inner wall in the long axis direction of the guide elongated hole slide.

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