WO2006103722A1

WO2006103722A1 - Circuit breaker and thermal trip

Info

Publication number: WO2006103722A1
Application number: PCT/JP2005/005562
Authority: WO
Inventors: Masatoshi Murai; Kouji Kawamura; Satoru Naito
Original assignee: Mitsubishi Denki Kabushiki Kaisha
Priority date: 2005-03-25
Filing date: 2005-03-25
Publication date: 2006-10-05
Also published as: JPWO2006103722A1; JP4399498B2; EP1863057A4; EP1863057A1; CN101147224B; EP1863057B1; CN101147224A

Abstract

A thermal trip comprises a bimetal (2) having one acting end (21) and the other cantilevered fixed end (22) secured to a heater (1) serving as a fixed terminal. The acting end (21) of the bimetal (2) bends as the bimetal is heated when the heater (1) is electrified. The thermal trip is characterized in that a temperature measuring member (7) is coupled integrally with the secured portion (221) of the bimetal (2) secured to the heater (1) and exposed from the bimetal (2) and the heater (1) so that the temperature measuring member (7) can touch a contact temperature sensor (8).

Description

Circuit breaker and thermal trip device

Technical field

[0001] In the present invention, the fixed end portion of the bimetal whose one end portion is an operating end portion and the other end portion is a fixed end portion is fixed to the fixed terminal in a cantilever manner, and is heated by overcurrent flowing through the fixed terminal. A circuit breaker having a thermal trip device that causes the operation end to trip the circuit breaker main body due to the curved bimetal, and a heater serving as a fixed terminal, one end of which is an operation end The fixed end of the bimetal, the other end of which is a fixed end, is fixed to the heater in a cantilever manner, and when the heater is overheated by energization, the operating end of the bimetal is bent. The present invention relates to a dynamic tripping device.

Background art

A thermal trip device is a device that detects, for example, an overcurrent in a circuit breaker and trips the main circuit of the circuit breaker body, and is a tripping feature when the overcurrent flows. The range of properties is defined by standards such as JIS (Japanese Industrial Standard), which is a Japanese industrial standard, and products must satisfy that range. However, in a thermal tripping device, variations in tripping characteristics are unavoidable due to product variations and material variations in the components. Therefore, a structure for adjusting the tripping characteristics is usually incorporated, and the characteristics are adjusted for inspection.

[0003] In order to adjust and inspect the trip characteristic, it is necessary to accurately measure the characteristic value. Thermal trip devices often measure the trip characteristics by measuring the time (trip time) and bimetal displacement until the energization start force is tripped by applying a predetermined current. On the other hand, since the curvature coefficient of bimetal is known, the amount of bimetal displacement can be obtained by measuring the bimetal temperature. Therefore, the trip characteristic can be grasped by measuring the bimetal temperature.

[0004] When measuring the nometal temperature, there is a view that a non-contact measurement method is desirable because the measurement does not affect the bimetal bending amount. The reason for this is that when measuring with a contact-type thermometer, an external force load is applied to the bimetal via a probe. As a result, stagnation occurs in the bimetal and changes the I release characteristics.

[0005] In the non-contact temperature measurement method, a radiation thermometer incorporating an infrared absorption element is generally used. Non-contact temperature measurement in a conventional thermal tripping device of a circuit breaker heats the bimetal so that the bimetal temperature can be measured with a non-contact thermometer, as seen in Patent Document 1, for example. The heater is equipped with a measurement window, and the temperature of the bimetal is measured with a radiation thermometer from the direction perpendicular to the bimetal surface through the window.

[0006] Patent Document 1: US Pat. No. 5,317,471 specification and drawings

Disclosure of the invention

Problems to be solved by the invention

[0007] A non-contact temperature measurement method using a non-contact thermometer is desirable, but there is a way of thinking, but since the bimetal surface is usually a metallic glossy surface, contact temperature measurement using a contact thermometer is recommended. There is a problem that accurate temperature measurement is difficult compared to the regular method. In addition, in the earth leakage breaker incorporating the earth leakage detection circuit and the circuit breaker downsized, there are few gaps around the bimetal, so there are many shields and the direction perpendicular to the bimetal surface by the non-contact thermometer. It is often difficult to measure the bimetal surface temperature from the outside.

Therefore, it is preferable to realize a thermal tripping device that does not affect the tripping characteristics even if a contact thermometer is used, and a circuit breaker using such a thermal tripping device.

[0009] The present invention has been made in view of the above circumstances, and is provided with a circuit breaker including a thermal trip device that does not affect trip characteristics even when a contact thermometer is used, and a thermal breaker. The purpose is to provide a dynamic trip device.

Means for solving the problem

[0010] In the circuit breaker according to the present invention, one end portion is an operating end portion and the other end portion is a fixed end portion. The fixed end portion of the bimetal is fixed to the fixed terminal in a cantilever manner, and the fixed terminal is In the circuit breaker having a thermal trip device in which the operation end performs a tripping operation of the circuit breaker body due to the curvature heated by the overcurrent flowing, the bimeter is connected to the fixed terminal. A temperature measuring member is attached to the fixed part with a contact temperature measuring device. The bimetal and the fixed terminal force are directly connected to each other so as to be exposed, and the contact-type temperature measuring device is brought into contact with the temperature measuring member without directly contacting the nanometal. Since the temperature of the bimetal can be measured, the temperature of the bimetal can be measured without affecting the trip characteristics.

[0011] In addition, the thermal tripping device according to the present invention provides a heater serving as a fixed terminal, and the fixed end of the bimetal whose one end is an operating end and the other end is a fixed end is cantilevered. In the thermal tripping device in which the operation end of the bimetal is bent when the heater is overheated by energization of the heater, a temperature measuring member is attached to the fixing portion of the bimetal to the heater. However, the bimetal and the heater force are also directly connected so that the contact-type temperature measuring device can be contacted, and the temperature is measured without bringing the contact-type temperature measuring device into direct contact with the bimetal. Since the temperature of the nanometal can be measured in contact with the measurement member, the temperature of the bimetal can be measured without affecting the tripping characteristics.

The invention's effect

[0012] In the present invention, the fixed end portion of the bimetal whose one end portion is an operating end portion and the other end portion is a fixed end portion is fixed to the fixed terminal in a cantilever manner, and is heated by overcurrent flowing through the fixed terminal. In the circuit breaker having a thermal trip device in which the operating end performs a tripping operation of the circuit breaker body due to the bent, the temperature measuring member is fixed to the fixing portion of the bimetal to the fixed terminal. However, it is directly connected to the bimetal and the fixed terminal so that the contact-type temperature measuring device can be contacted, so that the temperature can be measured without bringing the contact-type temperature measuring device into direct contact with the bimetal. The temperature of the nanometal can be measured by bringing it into contact with a measuring member, and therefore the temperature of the bimetal can be measured without affecting the tripping characteristics. Further, a contact-type temperature measurement method is adopted. Therefore, more accurate temperature measurement is possible than when a non-contact temperature measurement method using a non-contact thermometer is adopted.

[0013] According to the present invention, the fixed end of the bimetal whose one end is an operating end and the other end is a fixed end is fixed to the heater in a cantilever manner, Thermal tripping, where the working end of the bimetal bends when overheated by energizing In this apparatus, a temperature measuring member is directly coupled to the fixing portion of the bimetal to the heater so that the bimetal and the heater case are exposed so that a contact temperature measuring device can be contacted. Therefore, the temperature of the bimetal can be measured by bringing the contact-type temperature measuring device into contact with the temperature measuring member without directly contacting the bimetal, and thus the temperature of the bimetal can be measured without affecting the tripping characteristics. In addition, since a contact-type temperature measurement method is used, temperature measurement with higher accuracy is possible than when a non-contact temperature measurement method using a non-contact thermometer is used.

BEST MODE FOR CARRYING OUT THE INVENTION

[0014] Embodiment 1.

Embodiment 1 of the present invention will be described below with reference to FIGS. Fig. 1 is a side view showing a mechanism in a case of a circuit breaker having a thermal tripping device, Fig. 2 is an enlarged perspective view of the thermal tripping device of Fig. 1, and Fig. 3 is Fig. 1 Fig. 4 is a perspective view illustrating how to measure the bimetal temperature using a contact-type temperature measuring device, and Fig. 5 is a diagram showing the energization of the fixed terminal (ie, heater). It is an enlarged side view for demonstrating the bending | flexion operation | movement of a metal in the case. In FIG. 1 and FIG. 5, the same parts are denoted by the same reference numerals.

[0015] In FIG. 1, the operation when an overcurrent exceeding the rated current flows through the circuit breaker is as follows.

(1) When overcurrent flows through heater 1 or bimetal 2, the temperature of heater 1 or bimetal 2 rises.

(2) As the temperature of the bimetal 2 increases, the metal 2 is bent.

(3) The bending amount of bimetal 2 increases, and trip bar 3 is pressed.

(4) The mechanism unit 4 is activated and the main circuit 5 is instantaneously shut off (tripped).

[0016] The time from the start of overcurrent to the trip is defined by JIS standards and the like, and the product trip time must satisfy the range. However, the operating point of the trip mechanism, i.e., the position where the bimetal 2 pushes the trip bar 3, varies due to the accumulation of manufacturing variations such as machining errors of assembly parts, material characteristics variations, etc. of each part constituting the trip mechanism. It varies in the time (trip time) from the start of energization to the trip. Will occur. Therefore, in order to absorb such manufacturing variations, an adjustment mechanism 6 is provided at the tip of the bimetal 2 and the trip bar 3 to perform adjustment and inspection work in the assembly process.

Adjustment [0017] In inspection work, it is necessary to accurately measure the tripping characteristics of each workpiece. Usually, trip characteristics are often measured by measuring the trip time by applying a predetermined current value and measuring the amount of bimetal displacement during that time. However, the trip time and bimetal displacement are greatly affected by the workpiece temperature and measurement environment temperature at the start of energization. Measured values must be corrected! /.

[0018] On the other hand, since the force curve coefficient for which the bending amount (displacement amount) is determined by the temperature and the bending coefficient of the bimetal is known, the displacement amount can be obtained by measuring the bimetal temperature. Therefore, it is possible to measure the trip characteristics by measuring the bimetal temperature.

[0019] As described above, a non-contact type radiation thermometer is generally used to measure the bimetal temperature. This is because when a contact-type thermometer is used, the tripping characteristics change due to the stagnation of the metal due to the contact load of the measuring element, and accurate tripping characteristics cannot be measured.

[0020] A non-contact thermometer measures the temperature of an object by detecting the amount of infrared radiation energy radiated from the object. The amount of infrared radiation emitted from an object varies depending on the material and its surface condition, and the amount of infrared energy (emissivity) radiated differs even at the same temperature. For non-contact type thermometers, the temperature is calculated based on an ideal black body (theoretical object with 100% emissivity), and other objects must be corrected for the individual emissivity.

[0021] Since the emissivity is usually obtained experimentally, and it is difficult to obtain the emissivity of the measurement object in a short time, the emissivity cannot be obtained for each workpiece in the mass production process. Therefore, when the emissivity of bimetal varies, the variation becomes a variation in temperature measurement. Furthermore, since the bimetal surface is generally a metallic gloss surface, infrared rays emitted from the heat source of an object in the vicinity of the bimetal such as a heater are easily reflected on the bimetal surface. If the reflected light enters the radiation thermometer, a measurement error occurs. Therefore, in Embodiment 1 of the present invention, the temperature can be measured at a portion where the metal 2 is bent to push the trip bar 3, that is, at a location different from the operating end 21. This makes it possible to measure the temperature with a contact-type thermometer without affecting the amount of bending of the operating end 21 of the bimetal 2. Therefore, the temperature can be measured with higher accuracy and stability than with a conventional non-contact-type thermometer. .

[0023] In the heating of the nometal 2, it is difficult to uniformly heat the entire bimetal 2, and therefore a temperature distribution exists in the bimetal 2. That is, the fixed end 22 of the bimetal whose one end is the operating end 21 and the other end is the fixed end 22 is fixed to the fixed terminal (that is, the heater) 1 in a cantilevered manner. The temperature of the operating end 21 is slightly lower than the temperature of the fixed end 22 fixed to the terminal (ie, heater) 1. However, since the relationship between the temperature distribution in the metal 2 and the bending amount of the operating end 21 of the bimetal 2 is obtained in advance depending on the material and size of the bimetal 2, the temperature of the fixed end 22 is measured. In addition, the desired amount of bending of the operating end 21 of the bimetal 2 at that temperature can be obtained. Conversely, the standard temperature of the fixed end 22 when the working end 21 of the bimetal 2 has the desired amount of bending (that is, when the amount of bending causes the circuit breaker to trip) should be obtained. Can do. In other words, when the working end 21 of the bimetal 2 has the desired amount of bending (that is, when the amount of bending that causes the circuit breaker to trip is reached, or when the circuit breaker trips) If the measured temperature at the end 22 is the same as the standard temperature, it can be said that the tripping characteristic of the thermal tripping device is a predetermined tripping characteristic.

[0024] Therefore, in the first embodiment of the present invention, by adding a part having a temperature equivalent to the temperature of the fixed end part 22 of the nanometal 2, that is, the temperature measuring member 7, this added temperature measuring part is added. Instead of directly measuring the temperature of the fixed end 22 of the bimetal 2 with a contact thermometer, the temperature of the fixed end 22 of the bimetal 2 can be measured. In other words, as shown in FIG. 4, the temperature of the bimetal 2 is indirectly measured by measuring the temperature of the temperature measuring member 7 by bringing the probe 81 of the contact thermometer 8 into contact with the temperature measuring member 7. Can be measured.

The temperature measuring member 7 is connected to the fixing portion 221 of the bimetal 2 to the fixed terminal (ie, heater) 1 as shown in FIGS. 2 to 4. Contact type In order to be able to contact the measuring element 81 of the temperature measuring device 8, it is directly coupled integrally with the bimetal 2 and the fixed terminal (ie, heater) 1 so as to be exposed. That is, as shown in the drawing, the entire area of the temperature measuring member 7 is larger than the area of the portion of the temperature measuring member 7 facing the fixed terminal (ie, heater) 1.

[0026] In addition, it exists between the bimetal 2 and the fixed terminal (ie, heater) 1 and is firmly fixed to the fixed terminal (ie, heater) 1 together with the metal 2 by caulking stops 9 at a plurality of locations. I am doing. That is, the fixed end portion 22 of the bimetal 2, the temperature measuring member 7 and the fixed terminal (ie, heater) 1 are intimately joined together by the caulking stopper 9, and a good coupled state is maintained even thermally. It is supposed to be.

[0027] The tripping characteristic is inspected by the thermal tripping device shown in FIGS. 2 to 5 alone, or the thermal tripping device is incorporated in the circuit breaker as shown in FIG. In this case, when a current corresponding to a predetermined overcurrent is applied to the fixed terminal (ie, heater) 1, the operating end 21 of the bimetal 2 is at one point as shown in FIG. The temperature measuring member 7 bends like a chain line in the same direction as the operating end 21 of the bimetal 2.

[0028] The temperature measuring member 7 is made of the same material as the bimetal 2 (that is, when the bimetal 2 is a bonding material of iron and copper, the temperature measuring member 7 is also iron and copper). The temperature measuring member 7 is shorter than the length of the bimetal 2, and the operating end 21 and the temperature measuring member 7 of the bimetal 2 are Even if it bends like a chain line, the amount of bending of the temperature measuring member 7 is smaller than the amount of bending of the operating end 21 of the bimetal 2, so the tip of the temperature measuring member 7 and the operating end of the bimetal 2 There is a slight gap g between the part 21 and the part 21. Therefore, the temperature measuring member 7 does not come into contact with and press against the operating end 21 of the bimetal 2 due to its bending, and adversely affects the bending amount of the operating end 21 of the bimetal 2. There is no.

[0029] When the temperature measuring member 7 is bent opposite to the one-dot chain line in FIG. 5, the operation end 21 of the bimetal 2 is pressed during the bending, and the bimetal 2 Since this will adversely affect the amount of bending of the operating end 21, the dashed line in FIG. On the other hand, it must be avoided to bend so as to bend.

[0030] Embodiment 2.

The second embodiment of the present invention will be described below with reference to FIGS. 6 is a perspective view showing the thermal tripping device, FIG. 7 is a side view showing the thermal tripping device, and FIG. 8 is for explaining the bimetal bending operation when the fixed terminal (ie, the heater) is energized. FIG.

In Embodiment 2 of the present invention, as shown in FIGS. 6 to 8, the temperature measuring member 7 is opposite to the working end 21 of the bimetal from the fixing portion 221 of the bimetal 2. This is an example of extending to the side!

In this case, the temperature measuring member 7 is formed by extending the bimetal 2 itself to the side opposite to the operating end 21. In other words, the temperature measuring member 7 is configured so that the contact temperature measuring device 8 can be brought into contact with the fixing portion 221 of the bimetal 2 to the fixed terminal (that is, the heater) 1. That is, it is directly coupled integrally to the state exposed from the heater 1, and extends from the fixed portion 221 of the bimetal 2 to the side opposite to the operating end 21 of the bimetal.

In the case of Embodiment 2 of the present invention, as shown in FIGS. 7 and 8, the tip of the probe 81 of the contact-type temperature measuring device 8 is brought into contact with the lower surface of the temperature measuring member 7 to By measuring the temperature of the measuring member 7, the temperature of the bimetal 2 is indirectly measured.

[0034] In the case of Embodiment 2 of the present invention, the temperature measuring member 7 is curved as indicated by a dashed-dotted line by applying a current corresponding to a predetermined overcurrent to the fixed terminal (that is, the heater) 1. Even so, a slight force gap G is generated between the tip of the temperature measuring member 7 and the fixed terminal (ie, heater) 1. Therefore, when the temperature measuring member 7 comes into contact with the fixed terminal (ie, heater) 1 due to its curvature, no force is applied to the fixed end 22 of the bimetal 2, and the operation of the bimetal 2 is performed. There is no adverse effect on the bending amount of the end 21.

[0035] Embodiment 3.

In Embodiment 3 of the present invention, as shown in FIG. 9, a probe having a diameter larger than the diameter of the probe 81 of the contact-type temperature measuring device 8 is inserted into the fixed terminal (ie, heater) 1. An insertion through hole 12a is provided, and the measurement element 81 is inserted into the measurement element insertion through hole 12a so as not to contact the fixed terminal (that is, the heater) 1, and the tip of the measurement element 81 is inserted into the warm temperature. By measuring the temperature of the temperature measuring member 7 in contact with the lower surface of the degree measuring member 7, the temperature of the bimeter 2 is indirectly measured. Even if configured in this manner, the same effects as those of the second embodiment of the present invention described above can be obtained.

In the third embodiment of the present invention, specifically, as shown in the figure, the internal terminal at the end opposite to the external terminal portion 11 having the connection hole 1 la in the circuit breaker. The part 12 is provided with the probe insertion through hole 12a.

[0037] Embodiment 4.

As shown in FIG. 10, the third embodiment of the present invention has a structure in which the internal terminal portion 12 extends long to the inside of the circuit breaker main body, and the internal portion of the circuit breaker main body from the measuring element insertion through hole 12a. Connected to the connection terminal (not shown) inside the circuit breaker body, provided with a connection hole 12b that connects to the connection terminal (not shown) inside the circuit breaker body. Can be easily performed.

Brief Description of Drawings

FIG. 1 is a side view showing a mechanism part in a case of a circuit breaker having a thermal tripping device, showing Embodiment 1 of the present invention.

2 is a diagram showing the first embodiment of the present invention, and is an enlarged perspective view showing the thermal tripping device of FIG. 1. FIG.

3 is a diagram showing the first embodiment of the present invention, and is an enlarged side view showing the thermal tripping device of FIG. 1. FIG.

FIG. 4 shows the first embodiment of the present invention, and is a perspective view for explaining how to measure the bimetal temperature with a contact-type temperature measuring device.

FIG. 5 shows the first embodiment of the present invention and is an enlarged side view for explaining the bimetal bending operation when the fixed terminal (ie, heater) is energized.

FIG. 6 is a view showing a second embodiment of the present invention, and is a perspective view showing a thermal tripping device. FIG. 7 is a view showing a second embodiment of the present invention, and is a thermal trip device. It is a side view showing FIG. 8 is a diagram showing the second embodiment of the present invention, and is an enlarged side view for explaining the bending operation of the bimetal when the fixed terminal (ie, the heater) is energized.

圆 9] A view showing the third embodiment of the present invention and a side view showing the thermal tripping device. 圆 10] A diagram showing the fourth embodiment of the present invention and showing the thermal tripping device. FIG.

Explanation of symbols

1 Fixed terminal (heater) 11 External terminal

11a Connection hole 12 Internal terminal

12a Contact insertion hole 12b Connection hole

2 Nymanore 21 Operating end

22 Fixed end 221 Fixed part

3 Trip bar 4 Mechanism

5 Main circuit 6 Adjustment mechanism

7 Temperature measuring member 8 Contact thermometer

81 Measuring element 9

g Gap G Gap.

Claims

The scope of the claims

[1] The bimetal whose one end is an operating end and whose other end is a fixed end is fixed to the fixed terminal in a cantilevered manner and is overheated by an overcurrent flowing through the fixed terminal In the circuit breaker having a thermal trip device in which the operation end performs a tripping operation of the circuit breaker body due to the curvature of the temperature measuring member is a contact type at the fixing portion of the bimetal to the fixed terminal. A circuit breaker characterized by being directly and integrally coupled to the bimetal and the fixed terminal cover so that a temperature measuring device can be contacted.

[2] In the circuit breaker according to claim 1, the temperature measuring member exists between the bimetal and the fixed terminal and is fixed to the fixed terminal together with the bimetal! A circuit breaker characterized by squealing.

[3] In the circuit breaker according to claim 1, the temperature measuring member extends from the fixing portion of the bimetal to the side opposite to the operation end portion of the bimetal. Characteristic circuit breaker.

[4] In the circuit breaker according to claim 1-13, the temperature measuring member is formed of the same bimetal as the bimetal, and the fixed terminal force is separated when overheated by an overcurrent flowing through the fixed terminal. A circuit breaker that is curved in a direction.

[5] The fixed end of the bimetal whose one end is an operating end and the other end is a fixed end is fixed to the heater in a cantilevered manner to the heater serving as a fixed terminal. In the thermal tripping device in which the operating end of the bimetal is curved when overheated by the temperature, the temperature measuring member can contact the contact-type temperature measuring device to the fixing portion of the bimetal to the heater. A thermal tripping device, wherein the bimetal and the heater force are also directly coupled together in an exposed state.

[6] The thermal tripping device according to claim 5, wherein the temperature measuring member exists between the bimeter and the heater and is fixed to the heater together with the bimetal. Thermal tripping device.

[7] The thermal tripping device according to claim 6, wherein an area of the temperature measuring member is larger than an area of the temperature measuring member facing the heater. Thermal trip device.

[8] The thermal tripping device according to claim 5, wherein the temperature measuring member extends to the side opposite to the operation end of the bimetal. A thermal trip device.

[9] The thermal tripping device according to claim 8, wherein the heater is provided with a probe insertion through-hole having a diameter larger than the diameter of the probe of the contact-type temperature measuring device. Thermal trip device.

[10] The thermal tripping device according to claim 5-9, wherein the temperature measuring member is formed of the same bimetal as the bimetal, and the heater is heated when energized to the heater. A thermal tripping device characterized by bending in a force-separating direction.