JP2016001528A - Thermal tripping device in circuit breaker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermal tripping device in a circuit breaker which can adjust a breaking time to a desired time according to the magnitude of flowing current while keeping the amount of curvature of a bend member equivalent during rating current conduction.SOLUTION: The thermal tripping device comprises a bend member 12 one end of which is provided on a heater 11 provided on a current path in the circuit breaker, and the other end of which is able to extend toward a trip bar 4 by heat generation of the heater 11 due to overcurrent. The bend member 12 includes: a plurality of thermal deformation parts 120 formed by pasting two or more metal plates having different thermal expansion coefficients from each other in the thickness direction of the metal plates; and at least one heat-transferable joining part 121 for joining the plurality of thermal deformation parts 120. One of the plurality of thermal deformation parts 120 is a first thermal deformation part 120a directly heated by the heater 11. The thermal deformation parts 120 excluding the first thermal deformation part 120a are second thermal deformation parts 120b heated by the heated first thermal deformation part 120a via the joining part 121.

Description

  The present invention relates to a thermal trip device for an indirectly heated circuit breaker that uses a curved bimetal to block current.

  The bimetal whose base end is fixed to the heater provided in the current path is heated and bent by the heat generated by the heater due to the overcurrent flowing in the current path when the overcurrent (for example, short-circuit current) is energized. 2. Description of the Related Art Generally, a thermal trip device for a circuit breaker that cuts off a current when a free end contacts a trip bar of an opening / closing mechanism is known.

  Here, since the bimetal is composed of a single member, it takes time for the heat generated by the heater to be transferred to the tip side of the bimetal during overcurrent energization. This causes a time delay in the thermal tripping operation.

  Therefore, in order to prevent a time delay in the thermal tripping operation during overcurrent energization, the heat of the circuit breaker using a short bimetal and an extension plate attached to the end of the bimetal as a curved member. A dynamic tripping device has been proposed (see, for example, Patent Document 1).

  In the thermal trip device disclosed in Patent Document 1, one end of the extension plate is attached to the bimetal, and the free end that is the other end of the extension plate is bent along with the bending deformation of the bimetal heated by the heat generated by the heater. It is configured to displace and contact the trip bar.

  In the thermal trip device of a circuit breaker, when the rated current is applied, the current flowing in the circuit is not interrupted, and the current flowing in the circuit exceeds the rated current (when a large current is applied). It is required to cut off the current flowing in the circuit within a predetermined time for each current value. In addition, since the curved member needs to be arranged at a position where the curved curved member does not contact the trip bar when the rated current is applied, the bending amount of the curved member when the rated current is applied is the same regardless of the current value. It is required to be.

  Here, in the thermal tripping device for a circuit breaker disclosed in Patent Document 1, the circuit breaking time is reduced for each current value by adjusting the length of the bimetal and the extension plate constituting the bending member. It is possible to adjust.

JP 2010-218765 A

However, the prior art has the following problems.
In the bending member shown by patent document 1, since it is necessary to adjust the length of a bending member for every electric current value, the length of the bending member adjusted for every electric current value will differ. When the length of the bending member is changed, the amount of bending of the bending member when the rated current is applied also changes. Therefore, there is a problem that the cutoff time cannot be adjusted for each flowing current value while keeping the bending amount of the bending member equal when the rated current is applied.

  The present invention has been made in order to solve the above-described problems, and the cut-off time is set to a desired time according to the magnitude of the flowing current while keeping the bending amount of the bending member when the rated current is applied to be equal. It is an object of the present invention to obtain a thermal trip device for a circuit breaker that can be adjusted to the above.

  A thermal trip device for a circuit breaker according to the present invention is a thermal trip device for a circuit breaker that opens a switching mechanism by contacting a trip bar of the switching mechanism. Heater provided in the current path and one end are provided in the heater, heated by the heat transmitted from one end heated by the heat generated by the heater due to overcurrent, and the other end displaced toward the trip bar A plurality of heat-deformed portions formed by bonding two or more metal plates, each having a different thermal expansion coefficient, in the thickness direction of the metal plate; Each of the plurality of thermally deformable portions, and one of the plurality of thermally deformable portions is provided in the heater and directly heated from the heater. A first thermal deformation portion, Thermal deformation portion excluding the first thermal deformation portion of the deformation portion of the number is a second thermal deformation portion which is heated through the joint portion from the first heat deformation portion which is heated.

  According to this invention, the bending member of the thermal tripping device of the circuit breaker is configured with a plurality of heat deformation portions and at least one connection portion connecting each of the plurality of heat deformation portions. In addition, one of the plurality of thermal deformation portions is a first thermal deformation portion that is in direct contact with the heater, and the other thermal deformation portion is a second thermal deformation portion that is not in direct contact with the heater. Thereby, all the thermal deformation parts are involved in the bending amount of the bending member at the rated current, and only the first thermal deformation part is involved in the overcurrent energization. Therefore, the thermal breakage of the circuit breaker that can adjust the breaking time to a desired time according to the application while keeping the bending amount of the bending member when the rated current is energized to be equal. A removal device can be obtained.

It is sectional drawing of the circuit breaker provided with the thermal trip apparatus in Embodiment 1 of this invention. It is a block diagram which shows the thermal trip apparatus of FIG. It is a block diagram which shows the example of the bending member which varied the length of the 1st bimetal of FIG. 1, a 2nd bimetal, and a connection part. It is a figure which shows the relationship between the electric current value with respect to the rated current at the time of using the bending member of FIG. 3, and electric current interruption time. It is a block diagram which shows the thermal trip apparatus in Embodiment 2 of this invention. It is a block diagram which shows an example of the thermal trip apparatus in Embodiment 3 of this invention. It is a block diagram which shows an example of the thermal trip apparatus in Embodiment 3 of this invention. It is a block diagram which shows an example of the thermal trip apparatus in Embodiment 3 of this invention. It is a block diagram which shows an example of the thermal trip apparatus in Embodiment 4 of this invention. It is a block diagram which shows an example of the thermal trip apparatus in Embodiment 4 of this invention.

Embodiment 1 FIG.
FIG. 1 is a cross-sectional view of a circuit breaker provided with a thermal trip device according to Embodiment 1 of the present invention. As shown in FIG. 1, the circuit breaker includes a stator 1, a mover 2 disposed at a distance from the stator 1, and an opening / closing mechanism 3 that interrupts current by rotating the mover 2. The trip bar 4 provided in the opening / closing mechanism 3 and the thermal trip device 10 for operating the opening / closing mechanism 3 are housed in the case 5.

  The stator 1 is provided with a stationary contact 1a. The movable contact 2 is provided with a movable contact 2a so as to face the fixed contact 1a. The movable contact 2a comes into contact with the fixed contact 1a when the movable member 2 is rotated by the opening / closing mechanism 3. When the movable contact 2a and the fixed contact 1a are in contact with each other, the current is flowing in the circuit. FIG. 1 shows a state in which the movable contact 2a is separated from the fixed contact 1a, that is, an interrupted state in which the current is interrupted.

  The opening / closing mechanism 3 has a handle 3a and a movable arm 3b. Since the opening / closing mechanism 3 is not a main part of the present invention, a detailed illustration thereof is omitted, but for example, a configuration in which a link mechanism and a spring are combined. When the handle 3a is rotated in the direction of the arrow A in FIG. 1, the movable arm 3b is rotated, and accordingly, the movable contact 2a comes into contact with the fixed contact 1a and enters an energized state.

  FIG. 2 is a block diagram showing the thermal tripping device 10 of FIG. As shown in FIG. 2, the thermal tripping device 10 has a heater 11 and one end (fixed end) provided on the heater 11, and the other end (free end) can be displaced toward the trip bar 4. And a bending member 12. The opening / closing mechanism 3 is opened when the trip bar 4 is pushed by the other end of the bending member 12, and interrupts the current in the circuit.

  For the heater 11, a member having a larger electric resistance than the wiring used in the circuit is used. Here, when an overcurrent (a large current, for example, a short-circuit current) flows through the heater 11, the heater 11 generates heat due to Joule heat. The heat generated by the heater 11 is transmitted to the bending member 12.

  One end of the bending member 12 is attached to the heater 11 by a fastener 13 (for example, a rivet or a screw). Thereby, the bending member 12 can be easily fixed to the heater 11.

  Further, the bending member 12 includes a plurality of thermal deformation portions 120 and a connecting portion 121 that connects the plurality of thermal deformation portions 120. However, one of the thermal deformation portions 120 is attached to the heater 11 by the fastener 13. In this example, two thermal deformation portions 120 are provided, and one connecting portion 121 is provided.

  Each of the thermally deformable portions 120 includes two (or two or more) metal plates having different linear expansion coefficients from each other in the thickness direction of the metal plate (the thickness direction of the thermally deformable portion 120, and an arrow B in FIG. Bimetal (or trimetal) bonded in the direction) is used. Of the two metal plates constituting the bimetal, for example, a copper alloy obtained by combining nickel, chromium, and zinc with copper, or an alloy steel is used for the metal plate on the high expansion side. Of the two metal plates constituting the bimetal, alloy steel having a lower linear expansion coefficient than the metal plate on the high expansion side is used for the metal plate on the low expansion side.

  Hereinafter, of the two thermally deformable portions 120, the thermally deformable portion 120 that is in contact with the heater 11 and is fixed to the heater 11 by the fastener 13 is referred to as a first bimetal (first thermally deformable portion) 120 a, and the connecting portion 121. The thermally deformable portion 120 connected to the first bimetal 120a through the first will be referred to as a second bimetal (second thermally deformable portion) 120b.

  A metal plate that can conduct heat (for example, a Cu plate or an Al plate known as a metal plate having high thermal conductivity) is used for the connecting portion 121. In the first embodiment, the first bimetal 120a, the second bimetal 120b, and the connecting portion 121 are configured as a single plate. That is, the connecting part 121 connects the first bimetal 120a and the second bimetal 120b so that the surfaces of the metal plates constituting the first bimetal 120a and the second bimetal 120b are on the same plane. doing.

  A method of connecting the first bimetal 120a, the second bimetal 120b, and the connecting portion 121 is a method of connecting the individually manufactured first bimetal 120a, the second bimetal 120b, and the connecting portion 121 by brazing or soldering. Can be considered.

  In addition, in the manufacturing method of the bending member 12 comprised in plate shape, after manufacturing the 1st bimetal 120a and the 2nd bimetal 120b integrally, it cuts into the position which fits the connection part 121, and connects the connection part 121. A method of fitting is also conceivable. At this time, a part of the first bimetal 120a and the second bimetal 120b remains connected. In addition, there is also a method for manufacturing the bending member 12 in which a plurality of metal plates having different linear expansion coefficients are partially attached to one metal plate to form portions corresponding to the first bimetal 120a and the second bimetal 120b. Conceivable.

  The bending member 12 of the indirectly heated thermal trip device 10 is not directly energized, but receives heat generated by the heater 11 so that heat is transmitted in the order of the first bimetal 120a, the connecting portion 121, and the second bimetal 120b. The temperature of the entire bending member 12 rises. Along with this, the first bimetal 120a and the second bimetal 120b bend (bend) to the metal plate side on the low expansion side (that is, the metal plate side having a small linear expansion coefficient). The connecting portion 121 is also bent by bending the first bimetal 120a and the second bimetal 120b.

  Here, the first bimetal 120a and the second bimetal 120b need to bend toward the trip bar 4 side. Therefore, although not shown, both the first bimetal 120a and the second bimetal 120b are located closer to the trip bar 4 than the metal plate on the high expansion side in the direction of arrow B in FIG. Is arranged.

  Further, the bending member 12 does not push the trip bar 4 when the rated current flows, and the bending member 12 reliably pushes the trip bar 4 when the overcurrent flows. It is necessary to install in such a position. That is, it is necessary to design the bending amount of the bending member 12 to be smaller than the initial distance between the bending member 12 and the trip bar 4 when the rated current is supplied without interrupting the current. Further, the bending amount of the bending member 12 is the bending member 12 at the time of the limit current energization that is the limit current that always cuts off the current (at the time of overcurrent energization, for example, 125% with respect to the rated current). And the trip bar 4 must be designed to be larger than the initial distance.

  The amount of bimetal bending can be calculated by the following equation (1). Where D is the bimetal bending amount [mm], K is the bending coefficient [1 / K], ΔT is the rising temperature [K], L beam length [mm], and t is the thickness [mm]. is there.

  According to the above equation (1), the amount of bending of the bimetal is proportional to the bending coefficient determined from each metal constituting the bimetal and the first power of the rising temperature of the bimetal and the square of the length of the beam, It is inversely proportional to the first power. Here, since the allowable temperature of the heater 11 is determined by the material, it is possible to assume a case where the rising temperature of the heater 11 is constant by making the shape and resistance of the heater 11 the same. Thereby, the rising temperature of the bimetal can be determined from the thermal conductivity, heat capacity (specific heat / density) and shape of the bimetal.

  In the circuit breaker, the bending member 12 is required to interrupt the current flowing in the circuit within a preset time for each current value of the flowing current when overcurrent is applied. Here, the preset time is preset according to the design, and is set so that the cutoff time of the circuit becomes shorter as the current value becomes higher. For example, the circuit is cut off in a shorter time when the overcurrent is 200% of the rated current than when the overcurrent is 125% of the rated current.

  That is, in the thermal trip device 10, when an overcurrent exceeding the rated current flows in the circuit, the bending amount of the bending member 12 is set to change the circuit interruption time according to the magnitude of the flowing current. It is required to adjust. Hereinafter, as a specific example, the bending member is configured such that an overcurrent of 125% is a first current with respect to a rated current that is a limit current that always cuts off the current, and an overcurrent of 1000% with respect to the rated current is a second current. The adjustment of the 12 bending amount will be described.

  When the first current is supplied, the required current interruption time is longer than when the second current is supplied. Thereby, there is sufficient time until the heat generated in the heater 11 is transmitted to the entire bending member 12.

  Therefore, the first bimetal 120a that is in contact with the heater 11 and corresponds to the fixed end portion of the bending member 12, and the second bimetal 120b that corresponds to the distal end portion that is the free end portion of the bending member 12 are heated. There is almost no difference. Therefore, the amount of bending of the entire bending member 12 is determined by the bending due to the temperature rise of the first bimetal 120a and the second bimetal 120b.

  On the other hand, when energizing the second current, the time until the current is cut off is set to be very short in order to protect the equipment on the load side where the amount of heat generation increases. In addition, when the second current is energized, the second current is also energized inside the circuit breaker, so that the temperature of the components of the circuit breaker energizing path including the heater 11 serving as the energizing path increases instantaneously. Accordingly, the temperature of the first bimetal 120a in contact with the heater 11 rises according to the thermal resistance and heat capacity of the used bimetal.

  However, it takes time for the temperature of the second bimetal 120b at the tip portion not in contact with the heater 11 to rise in temperature. Thereby, at the time of 2nd electric current energization, the bending amount of the whole bending member 12 is determined by the temperature rise of the 1st bimetal 120a.

  As described above, in addition to the first bimetal 120a, the bending amount of the second bimetal 120b that is not attached to the heater 11 is added to the bending amount of the entire bending member 12 under the condition of spending a long time before interruption when the first current is applied. Used. On the other hand, the amount of bending of the entire bending member 12 under the condition that the interruption time during the second current application is short is the amount of bending of the first bimetal 120a attached to the heater 11 that most affects the total amount of bending of the bending member 12. Is used.

  Accordingly, when the length of the first bimetal 120a is shortened and the length of the second bimetal 120b is lengthened, and when the length of the first bimetal 120a is lengthened and the length of the second bimetal 120b is shortened. Then, while the amount of bending of the entire bending member 12 at the time of the first current application is made the same, the amount of bending of the entire bending member 12 can be increased as the length of the first bimetal 120a is longer at the time of the second current application. it can.

  That is, by adjusting the lengths of the first bimetal 120a and the second bimetal 120b, the amount of bending of the entire bending member 12 and the circuit interruption time can be adjusted according to the magnitude of the current. In addition, the amount of bending of the entire bending member 12 can also be adjusted by adjusting the length of the connecting portion 121 that is bent by the bending of the first bimetal 120a and the second bimetal 120b.

  Here, the relationship between the bending amount of the bending member 12 and the circuit cut-off time due to the difference in the lengths of the first bimetal 120a, the second bimetal 120b, and the connecting portion 121 will be described with reference to FIGS. FIG. 3 is a configuration diagram illustrating an example of the bending member 12 in which the lengths of the first bimetal 120a, the second bimetal 120b, and the connecting portion 121 in FIG. FIG. 4 is a diagram showing the relationship between the current value and the current interruption time with respect to the rated current when the bending member 12 of FIG. 3 is used.

  In FIG. 3, the bending member 12 shows three examples (a) to (c). As shown in FIG. 3, the length of the first bimetal 120a is longer in (b) than in (a) and in (c) than in (b). Therefore, the influence of the amount of bending on the entire bending member 12 is greater in (c) than in (b) and (b) than in (a).

  For this reason, while setting the length of the 2nd bimetal 120b in a front-end | tip part so that (c) may become shorter than (b) and (b) rather than (a), the length of the connection part 121 which does not curve directly. This is set so that (b) is longer than (a) and (c) is longer than (b). Thus, by setting the lengths of the first bimetal 120a, the second bimetal 120b, and the connecting portion 121, as shown in the portion surrounded by C in FIG. The amount of bending can be made equal in (a) to (c).

  In addition, when an overcurrent with a short interruption time is applied as in the case of the second current energization, heat is hardly transmitted to the second bimetal 120b at the tip, and the temperature does not increase. The amount of bending of the entire bending member 12 is determined by 120a. That is, the amount of bending decreases in (a) than in (b) and (b) than in (c). Therefore, as shown in the part surrounded by D in FIG. 4, it is possible to delay the interruption time until the current is interrupted.

  Next, the operation of the thermal trip device 10 will be described. When an overcurrent exceeding the rated current flows in the energized state, the temperature of the heater 11 rises. The amount of heat generated by the heater 11 increases according to the square of the current and the first power of the resistance of the heater 11. That is, when the energization current in the circuit increases, the amount of heat generation increases with the square of the current value, the electrical resistance increases with the temperature rise of the heater 11 itself, and the temperature rise of the heater 11 increases.

  As the rising temperature of the heater 11 increases, the amount of heat transferred to the bending member 12 also increases. The first bimetal 120a and the second bimetal 120b bend toward the trip bar 4 as the temperature rise of the heater 11 increases. At this time, when the second bimetal 120b corresponding to the free end not directly fixed to the heater 11 presses the trip bar 4, the opening / closing mechanism 3 operates, and the movable contact 2a is separated from the fixed contact 1a. Thereby, the electric current in a circuit is interrupted | blocked.

  As described above, in the thermal trip device according to the first embodiment, the bending member is composed of a plurality of bimetals and connecting portions that connect the bimetals. In addition, among the plurality of bimetals, one bimetal is attached to the heater, and the other bimetals are not attached to the heater. With such a configuration, the amount of bending of the entire bending member during energization of the rated current and the overcurrent energization that can be spent for a long time before the circuit is cut off is determined using the amount of bending of all the bimetals. can do.

  Further, the bending amount of the entire bending member during overcurrent energization, which is a short time until the circuit is cut off, can be determined only by the bending amount of the first bimetal. Therefore, only by adjusting the length of the first bimetal, it is possible to adjust the current interruption time during overcurrent energization to a desired time according to the application. As a result, it is possible to obtain a curved member capable of adjusting the interruption time both during rated current application and overcurrent application. That is, the cut-off time can be adjusted to a desired time according to the magnitude of the flowing current while keeping the bending amount of the bending member when the rated current is energized to be equal. Therefore, a highly reliable circuit breaker can be obtained.

  In the thermal trip device for a circuit breaker disclosed in Patent Document 1, since the bimetal is short, the bending amount of the entire bending member is the bending amount of the bimetal formed of a single member. It will be greatly reduced. Thereby, the distance between the bending member and the trip bar is designed to be narrow. As a result, there has been a problem that it is not possible to tolerate variations in physical property values of components constituting the thermal trip device of the circuit breaker and variations in time taken to interrupt current generated due to processing / manufacturing errors. . Accordingly, there is a problem that it is difficult to adjust the distance between the bending member and the trip bar.

  On the other hand, since the bending amount of the bending member when the rated current is applied in the first embodiment is the sum of all the bendings of the plurality of bimetals, the bending amount of the entire bending member can be ensured. Therefore, although the bending amount of the bending member when the rated current is passed in the first embodiment is configured by a single member and is smaller than the bending amount of the bimetal, the bending amount of the bending member shown in Patent Document 1 It can be made larger. Thereby, adjustment of the distance of a bending member and a trip bar can be performed easily.

  In addition, in the thermal trip device for a circuit breaker disclosed in Patent Document 1, in order to increase the distance between the bending member and the trip bar, it is equivalent to the bending amount of the bimetal formed by a single member. When the bending member shown in Patent Document 1 tries to obtain the amount of bending, it is necessary to make the length of the bimetal and the extension plate longer than that shown in Patent Document 1. This affects the overall shape of the circuit breaker and restricts the structure.

  On the other hand, in the bending member of the first embodiment, the amount of bending of the entire bending member can be ensured, so that the distance between the bending member and the trip bar can be ensured. As a result, it is possible to prevent the length of the bending member from affecting the overall shape of the circuit breaker and eliminate the risk of restricting the structure. Furthermore, since it is not necessary to make the allowable temperature of the heater higher than in the past in order to increase the bending amount of the bending member, it is possible to prevent an increase in cost.

  Moreover, in order to make the bending amount of the bending member of the thermal tripping device of the circuit breaker disclosed in Patent Document 1 equal to the bending amount of the bimetal formed of a single member, the bimetal bends. It is also conceivable to increase the amount of bending during energization in the vicinity of the rated current by increasing the temperature as compared with the conventional case. However, in order to increase the temperature of the bimetal, it is necessary to increase the electrical resistance of the member that overheats the bimetal and to change it to a high allowable temperature. This leads to an increase in the cost of the thermal tripping device for the circuit breaker and a problem that it is necessary to pay attention to the surrounding environment in which the circuit breaker is used.

  On the other hand, in the bending member of this Embodiment 1, since a connection part is pinched | interposed between each bimetal, it can lead to cost reduction rather than the bending member comprised with the single bimetal.

  In the first embodiment, the same bimetal is used for the first bimetal 120a and the second bimetal 120b, but bimetals having different curvature characteristics or shapes may be used. For example, when the current interruption time is delayed during overcurrent energization, the bending characteristic of the first bimetal 120a is smaller than that of the second bimetal 120b. Or what increased the thickness of the 1st bimetal 120 rather than the 2nd bimetal 120b may be used. Thereby, the effect on the extension of the shut-off time can be increased as compared with the case of only the length of the bimetal.

  Further, the shape and material of the connecting portion 121 may be changed. For example, the current interruption time can be reduced by making the thickness of the connecting portion 121 smaller than that of the first embodiment or using a material having a lower thermal conductivity than that of the first embodiment for the connecting portion 121. Can be further delayed.

  In the first embodiment, the bending member 12 is composed of two bimetals 120 and one connecting portion 121. However, the present invention is not limited to this, and two or more bimetals 120 and bimetal 120 You may be comprised with the several connection part 121 matched with the number. Thereby, not only the rated current and the overcurrent but also the intermediate time between the rated current and the overcurrent can be adjusted more finely.

  Furthermore, in the first embodiment, the low expansion side metal plate and the high expansion side metal plate are attached to the bimetal. However, the present invention is not limited to this. For example, a metal plate having a linear expansion coefficient intermediate between the high expansion side and the low expansion side may be inserted between the low expansion side metal plate and the high expansion side metal plate, and the trimetal may be curved as a whole. In the case of a trimetal, the metal plate placed between them is preferably copper, which is known as a member having high thermal conductivity, but may be a copper alloy with nickel or zinc. By making the bimetal a trimetal, the thermal resistance of the bimetal is reduced and the temperature rise of the bimetal is promoted, so that the bending amount of the bending member 12 is increased.

Embodiment 2. FIG.
In the first embodiment, the example in which the bending member 12 is attached to the heater 11 by the fastener 13 has been described. In contrast, in the second embodiment, an example in which the bending member 12 is attached to the heater 11 by brazing or soldering will be described.

  FIG. 5 is a configuration diagram showing the thermal trip device 10 according to the second embodiment of the present invention. As shown in FIG. 5, the first bimetal 120a is attached to the heater 11 by brazing or soldering. For the solder or solder used at this time, a heat-transferable material (a material having high thermal conductivity) is used. Other configurations are the same as those of the first embodiment.

  As described above, in the thermal tripping device according to the second embodiment, the bending member and the heater are connected using a heat-transferable material. By providing such a configuration, it is possible to eliminate the need for a fastener, and the magnitude of the flowing current while maintaining the same bending amount of the bending member at the time of energizing the rated current as in the first embodiment. Accordingly, it is possible to obtain an effect that the blocking time can be adjusted to a desired time.

Embodiment 3 FIG.
In the first embodiment, the example in which the first bimetal 120a, the second bimetal 120b, and the connecting portion 121 are arranged on the same plane has been described. In contrast, in the third embodiment, an example in which at least one of the first bimetal 120a, the second bimetal 120b, and the connecting portion 121 is shifted from the same plane will be described.

  6-8 is a block diagram which shows an example of the thermal trip device 10 in Embodiment 3 of this invention. In the bending member 12 of FIG. 6, the first bimetal 120a and the second bimetal 120b provided in the heater 11 are arranged at a distance from each other, and the metal plates of the first bimetal 120a and the second bimetal 120b. Are attached on the same plane. That is, the first bimetal 120a and the second bimetal 120b are equidistant from the trip bar 4 in the thickness direction of the first bimetal 120a and the second bimetal 120b (the direction of arrow E in FIG. 6).

  Moreover, the connection part 121 is arrange | positioned in the position shifted | deviated from the same plane where the 1st bimetal 120a and the 2nd bimetal 120b are arrange | positioned. In this example, in the direction of arrow E, the connecting portion 121 is disposed closer to the trip bar 4 than the first bimetal 120a and the second bimetal 120b.

  The lower ends of the first bimetal 120a and the connecting portion 121 and the upper ends of the second bimetal 120b and the connecting portion 121 are fixed by the fasteners 13, respectively. Other configurations are the same as those of the first embodiment.

  Further, in the bending member 12 of FIG. 7, the second bimetal 120 b is more than the first bimetal 120 a provided in the heater 11 in the thickness direction of the first bimetal 120 a and the second bimetal 120 b (the arrow F direction in FIG. 7). It is arranged at a position close to the trip bar 4. That is, the attachment surfaces of the metal plates of the first bimetal 120a and the second bimetal 120b are arranged in parallel. Moreover, the connection part 121 is arrange | positioned between the 1st bimetal 120a and the 2nd bimetal 120b.

  At this time, the first bimetal 120a is attached to the lower end portion of the surface of the connecting portion 121 away from the trip bar 4 in the arrow F direction, and the upper end portion of the surface of the connecting portion 121 close to the trip bar 4 in the arrow F direction. The 2nd bimetal 120b is attached to. That is, when the first bimetal 120a and the second bimetal 120b are projected in the direction of the arrow F, the connecting part 121 prevents the first bimetal 120a and the second bimetal 120b from overlapping each other. Bimetal 120b is connected. Accordingly, the first bimetal 120a, the second bimetal 120b, and the connecting portion 121 are arranged in a staircase pattern.

  The first bimetal 120a and the connecting portion 121, and the second bimetal 120b and the connecting portion 121 are attached by brazing or soldering, respectively. Other configurations are the same as those of the first embodiment.

  Moreover, the bending member 12 of FIG. 8 is a modification of FIG. The first bimetal 120a and the second bimetal 120b are attached to the entire surface of the connecting portion 121 away from the trip bar 4 in the direction of arrow G in FIG. 8 corresponding to the direction of arrow F in FIG. The second bimetal 120b is attached to the entire surface of the connecting portion 121 close to the trip bar 4 in the direction. That is, when the first bimetal 120a and the second bimetal 120b are projected in the direction of arrow G, the connecting portion 121 overlaps the first bimetal 120a so that at least a part of the projected region of the first bimetal 120a and the second bimetal 120b overlaps. And the second bimetal 120b.

  The first bimetal 120a, the second bimetal 120b, and the connecting portion 121 are all fixed by a single fastener 13. Other configurations are the same as those of the first embodiment.

  As described above, in the thermal trip device according to the third embodiment, at least one of the first bimetal, the second bimetal, and the connecting portion is arranged so as to be shifted from the same plane. By providing these configurations, the dimensions in the height direction of the case are the same as in the first embodiment, even when the first bimetal, the second bimetal, and the connecting portion cannot be arranged on the same plane. It is possible to obtain an effect that the cut-off time can be adjusted to a desired time according to the magnitude of the flowing current while keeping the bending amount of the bending member equal to when the rated current is supplied. In addition, the height direction of a case here is the up-down direction of FIGS.

  Further, since the position of the second bimetal of the bending member shown in FIG. 7 and FIG. 8 is closer to the trip bar than the position of the second bimetal of the bending member of FIG. The total amount of bending can be increased by the distance between the thickness of the first bimetal and the connecting portion.

  Furthermore, the bending member shown in FIG. 8 can fix two bimetals and one connecting portion with one fastener. Thereby, the increase in cost by the increase in a fastener can be suppressed.

Embodiment 4 FIG.
In the fourth embodiment, although not provided in the first embodiment, an example in which a heat capacity body in contact with the first bimetal 120a is provided in a fixed portion between the bending member 12 and the heater 11 will be described.

  9 and 10 are configuration diagrams showing an example of the thermal trip device 10 according to the fourth embodiment of the present invention. As shown in FIG. 9, the heat capacity body 20 is attached to the surface of the first bimetal 120 a close to the trip bar 4 in the thickness direction of the first bimetal 120 a and the second bimetal 120 b (the arrow H direction in FIG. 9). .

  The heat capacity body 20 is fixed integrally with the bending member 12 and the heater 11 by a rivet 13 that fixes the first bimetal 120 a and the heater 11. Therefore, the heat capacity body 20 and the first bimetal 120a are in contact with each other. Other configurations are the same as those of the first embodiment.

  As shown in FIG. 10, the heat capacity body 20 may be disposed between the first bimetal 120 a and the heater 11. That is, the heat capacity body 20 is attached to the surface of the first bimetal 120a away from the trip bar 4 in the thickness direction of the first bimetal 120a and the second bimetal 120b (the direction of arrow I in FIG. 10).

  The heat capacity body 20 is fixed integrally with the bending member 12 and the heater 11 by a rivet 13 that fixes the first bimetal 120 a and the heater 11. Therefore, the heat capacity body 20 and the first bimetal 120a are in contact with each other. Other configurations are the same as those of the first embodiment.

  The heat capacity body 20 shown in FIGS. 9 and 10 uses a member that can absorb heat transmitted to the bending member 12. In the fourth embodiment, for example, Cu (copper) or Al (aluminum), which is a metal that can conduct heat and is known as a metal having high thermal conductivity, is used for the heat capacity body 20. Thereby, compared with the heat resistance of the bending member 12 when the heat capacity body 20 is not provided, the heat capacity of the bending member 12 can be increased without significantly changing the heat resistance.

  In addition, when the overcurrent (first current) is supplied with a long interruption time, the entire bending member 12 has a temperature rise equivalent to that when the heat capacity body 20 is not used, and the bending amount of the entire bending member 12 and the interruption of the current are interrupted. Time does not change. Furthermore, at the time of overcurrent (second current) energization with a short interruption time, it is possible to suppress the temperature rise by using the heat capacity body 20 in contact with the first bimetal 120a that is the base of the bending member 12. Thereby, the bending amount of the bending member 12 can be made small, and the interruption | blocking time of an electric current can be delayed.

  When it is desired to greatly delay the current interruption time, it can be dealt with by increasing the size of the heat capacity body 20 to a size that does not cause a problem in the design.

  When it is necessary to delay the shut-off time, the heater 11 and the first bimetal 120a are provided between the heater 11 and the first bimetal 120a by providing the heat capacity body 20 having a lower thermal conductivity than Cu or Al. It is also possible to increase the thermal resistance between the two and reduce the temperature rise during rated energization.

  As described above, in the thermal tripping device according to the fourth embodiment, the heat capacity body in contact with the first bimetal provided in the heater is used. Moreover, the heat capacity of the bending member can be adjusted by changing the material and shape of the heat capacity body. By providing such a configuration, even when the same bending member is used, it is possible to obtain an effect that the cutoff time can be adjusted to a desired time according to the magnitude of the flowing current.

  In the fourth embodiment, the example in which the heat capacity body 20 is provided in the fixed portion between the heater 11 and the first bimetal 120a has been described. However, the heat capacity body 20 is not limited to the time when the first current is applied, but also the second current. It also greatly affects the shut-off time when energized. Therefore, when it is necessary to make it difficult to influence the interruption time when the second current is applied, not between the heater 11 and the first bimetal 120a, but between the first bimetal 120a and the connecting portion 121, or the connecting portion 121. By using a heat capacity body between the first bimetal 120b and the second bimetal 120b, it is possible to delay the interruption time when the first current is energized and increase the interruption time when the second current is energized.

  Moreover, although the metal which can be heat-transferred is used for the heat capacity body 20 of this Embodiment 4, it is not restricted to this. For example, a resin material such as PET (polyethylene terephthalate) or PP (polypropylene) may be used.

  Furthermore, although the example which provided one heat capacity body 20 was demonstrated in this Embodiment 4, it is not restricted to this, The heat capacity body 20 may be provided two or more (plural).

  In the fourth embodiment, the heat capacity body 20 is fixed by using the fastener 13 integrally with the heater 11 and the first bimetal 120a. However, the present invention is not limited to this. Alternatively, it may be fixed by soldering.

  Further, in the fourth embodiment, the bending member 12 has the single plate shape used in the first embodiment, but the present invention is not limited to this, and the bending shown in the third embodiment is performed. It may be applied to the member 12.

  3 Opening / Closing Mechanism, 4 Trip Bar, 10 Thermal Trip Device, 11 Heater, 12 Bending Member, 20 Heat Capacity, 120 Thermal Deformation Part, 120a First Bimetal (First Thermal Deformation Part), 120b Second Bimetal (Second Thermal deformation part), 121 connecting part.

Claims (8)

A thermal tripping device for a circuit breaker that performs an opening operation of the switching mechanism by contacting a trip bar of the switching mechanism,
The heater provided in the current path in the circuit breaker, and one end are provided in the heater, and are heated by the heat transmitted from the one end heated by the heat generated by the heater due to overcurrent. A curved member whose end is displaceable toward the trip bar;
The bending member includes a plurality of heat-deformed portions formed by bonding two or more metal plates each having a different coefficient of thermal expansion in the thickness direction of the metal plate, and a member capable of transferring heat. And at least one connecting part that connects each of the thermal deformation parts of
One of the plurality of heat-deformed portions is a first heat-deformed portion provided in the heater and directly heated from the heater,
Among the plurality of deformable portions, the heat deformable portion excluding the first heat deformable portion is a second heat deformable portion that is heated from the heated first heat deformable portion via the connecting portion. Movable trip device. The connecting portion connects each of the plurality of thermally deformable portions so that the surfaces of the plurality of thermally deformable portions bonded to the metal plate are on the same plane with respect to each of the plurality of thermally deformable portions. The thermal trip device for a circuit breaker according to claim 1. Each of the plurality of thermally deformable portions is arranged such that, when the plurality of thermally deformable portions are projected in the thickness direction, the connection regions of the thermally deformable portions adjacent to each other do not overlap or at least partially overlap. The circuit breaker according to claim 1, wherein each of the plurality of heat-deformed portions is connected so that surfaces of the metal plates bonded to each other are parallel to each other. Thermal tripping device for the vessel. The thermal trip device for a circuit breaker according to any one of claims 1 to 3, wherein the bending member is provided with a heat capacity body that absorbs heat transmitted to the bending member. The thermal trip device for a circuit breaker according to any one of claims 1 to 4, wherein the first thermal deformation section is fixed to the heater by a fastener. The thermal trip device for a circuit breaker according to any one of claims 1 to 4, wherein the first thermal deformation portion is fixed to the heater by brazing or soldering. The said 1st deformation | transformation part and the said 2nd deformation | transformation part are being fixed to the said connection part by the fastener at one place. Thermal attraction of the circuit breaker as described in any one of Claims 1-6. Removal device. The said 1st deformation | transformation part and the said 2nd deformation | transformation part are being fixed to the said connection part by solder | pewter or solder, The thermal trip apparatus of the circuit breaker as described in any one of Claims 1-6. .

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