JPH1186717A - Bimetal fixing structure of circuit breaker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain more stable electricalal contact and reliability of a caulking part with respect to expansion and curving of a bimetal due to overcurrent and continuous power supply and obtain a fixing structure, in which turning or movement of the bimetal is prevented, even if only one caulking part is provided. SOLUTION: In a structure in which one end of a bimetal for overcurrent tripping is superposed on a power supply conductor 12, is engaged by employing a rivet 13 penetrating caulking holes 11a and 12a bored at that superposed part and done so as to supply power to the bimetal 11 via this caulking part, female screw machining is applied to the caulking holes 11a and 12a to prevent looseness of axial caulking of the rivet 13.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bimetal fixing structure used as an overcurrent trip device in a relatively small circuit breaker such as a circuit breaker for wiring.

[0002]

2. Description of the Related Art FIGS. 5 and 6 show a conventional bimetal fixing structure in an overcurrent tripping device for a circuit breaker. FIG. 5 is a perspective view showing the entire structure, and FIG. It is sectional drawing which follows C. In the figure, 1 is a bimetal for tripping overcurrent (hereinafter referred to as bimetal), 1b is a high expansion side, and 1c is a low expansion side. Reference numeral 2 denotes an energizing conductor (hereinafter, referred to as a conductor) for energizing the bimetal 1, and is, for example, a component integrally formed with a terminal fitting (not shown) for connecting to a distribution line. Reference numeral 3 denotes a rivet which is swaged through swaging holes 1a and 2a formed in the bimetal 1 and the conductor 2. As shown in FIG. 5, the crimped portion has the bimetal 1 and the conductor 2 superposed at two places fixed by crimping. Electric power is supplied to the bimetal 1 through the overlapped portion.

In such a conventional bimetal fixing structure of a circuit breaker, the bimetal 1 is prevented from rotating by fixing the bimetal 1 at two places.
An energization path is formed so that a current flows through the bimetal 1 via the conductor 2. When an overcurrent flows through the current path, the bimetal 1 is heated and bent toward the low expansion side, and a trip device (not shown) is operated to perform a trip operation of the circuit breaker.

[0004]

In the above-described conventional bimetal fixing structure, as shown in FIG. 6, the contact between the bimetal 1 and the rivet 3 inside the caulking holes 1a and 2a of the conductor 2 is caused by buckling. Is hardly seen except for. Therefore, since the bimetal 1 expands and bends due to the overcurrent and continuous energization, stress is applied to the caulked portion, and the caulked portion of the rivet 3 is loosened in the axial direction, resulting in poor electrical contact. In addition, if the caulking is incomplete, the tripping characteristics may change due to rotation or movement of the bimetal 1, so that it is necessary to fix by soldering or caulking at a plurality of locations, and the number of parts is reduced. There was also a problem that it became more expensive.

The present invention has been made in order to solve the above-mentioned problems, and the rivet 3 can be appropriately brought into contact with the rivet 3 even inside the caulking holes 1a and 2a of the bimetal 1 and the conductor 2 to make the rivet 3 The bimetal 1 is completely fixed by preventing loosening in the axial direction. With this fixing structure, more stable electrical contact and reliability of the swaged portion can be obtained with respect to the expansion and bending of the bimetal 1 due to overcurrent and continuous energization. It is intended to obtain an effect such as prevention of rotation or movement.

[0006]

A bimetal fixing structure for a circuit breaker according to the present invention is characterized in that one end of an overcurrent tripping bimetal is overlapped on a current-carrying conductor, and a caulking machine is formed in the overlapped portion. A crimping method using a rivet that penetrates the hole, and an electric current applied to the bimetal through the crimping portion, wherein the crimping hole is subjected to internal thread processing to ensure contact between the crimping hole and the rivet. It is.

Further, a portion in which one end of an overcurrent trip bimetal is overlapped on a current-carrying conductor is caulked with one rivet.

Further, a protrusion is provided on one of the overlapping portions of the conducting conductor and the overcurrent tripping bimetal, and a positioning hole formed so as to fit the protrusion is provided on the other to prevent rotation. .

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiment 1 FIG. 1 and 2 show a bimetal fixing structure of a circuit breaker according to a first embodiment of the present invention. FIG. 1 is a perspective view, and FIG. 2 is a sectional view taken along line AA of FIG. is there. In the figure, 11 is a bimetal for tripping overcurrent (hereinafter referred to as bimetal), 11b is a high expansion side, and 11c is a low expansion side. Reference numeral 12 denotes a current-carrying conductor (hereinafter, referred to as a conductor) for supplying current to the bimetal 11, and is a component integrally formed with, for example, a terminal fitting (not shown) for connecting to a distribution line. Reference numeral 13 denotes a rivet for fixing the bimetal 11 to the conductor 12, and a caulking hole 11 formed in a portion where the bimetal 11 and the conductor 12 overlap.
a and 12a. The rivet 11 is made of a soft copper material.

The caulking holes 11a and 12a are provided at one location substantially at the center of the portion where the bimetal 11 and the conductor 12 are superimposed. Further, as shown in FIG. Female thread processing is applied. This female screw is formed by tapping. The shape of the screw thread may be a coarse thread, but may be a fine thread if the bimetal 11 is thin. However, it is not necessary to process the thread into an accurate thread, and a thread having a simple shape with unevenness may be used.

When the rivets 13 made of a soft copper material are passed through the caulking holes 11a and 12a which have been subjected to the female screw processing as described above, the rivets 1 are formed as shown in FIG.
Due to the deformation of 3, the rivet 13 is caulked in a state where the rivet 13 is fitted into the female threaded portions of the caulking holes 11a and 12a.

[0012] In the bimetal fixed structure configured as described above, the bimetal 11 and the conductor 12 are formed by caulking holes 1.
The rivet 13 is set into the female threaded portions 1a and 12a and firmly crimped. Therefore, even when the bimetal 11 expands and bends due to an overcurrent and a continuous current, a stable electric contact can be obtained without the loosening of the rivet 13 in the axial direction. In addition, since the above-described strong caulking has a detent function, even if only one caulking portion is provided, rotation or movement of the bimetal 11 is prevented.

Embodiment 2 FIG. 3 and 4 show a bimetal fixing structure of a circuit breaker according to a second embodiment of the present invention. FIG. 3 is a perspective view, and FIG. 4 is a line BB in FIG.
FIG. In the figure, 11d is a positioning hole formed in the bimetal 11, 12b is a projection protruding from the conductor 12, and is a positioning hole 11d of the bimetal 11.
It is inserted in.

According to the second embodiment, when assembling the conductor 12 and the bimetal 11, the positioning hole 11d is inserted into the projection 12b, so that the caulking hole 12a of the conductor 12 and the caulking hole 11a of the bimetal 11 are formed. And the rivet 13 can be easily inserted. Further, after the rivet 13 is swaged, the rotation of the conductor 12 and the bimetal 11 in the rotation direction is reliably prevented.
In the above embodiment, the positioning holes 1 are formed in the bimetal 11.
Although 1d is provided and the protrusions 12b are provided on the conductor 12, the conductor 12 may be provided with a positioning hole and the bimetal 11 may be provided with a protrusion.

[0015]

Since the present invention is configured as described above, it has the following effects.

Since the swaged holes are internally threaded to ensure the contact between the swaged holes and the rivet, the expansion and bending of the bimetal due to overcurrent and continuous energization, particularly, the loosening of the rivet in the axial direction. As a result, stable electrical contact and reliability are obtained.

Further, since the fixing portion (the caulking portion) of the bimetal can be reduced to one location, it can be manufactured at low cost.

Furthermore, a projection is provided on one of the overlapping portions of the conducting conductor and the overcurrent tripping bimetal, and a positioning hole formed so that the projection is fitted on the other is provided. And the rotation in the rotation direction is surely ensured.

[Brief description of the drawings]

FIG. 1 is a perspective view of a bimetal fixing structure of a circuit breaker according to Embodiment 1 of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a perspective view of a bimetal fixing structure of a circuit breaker according to a second embodiment of the present invention.

FIG. 4 is a sectional view taken along line BB of FIG. 3;

FIG. 5 is a perspective view showing a bimetal fixing structure of a conventional circuit breaker.

FIG. 6 is a sectional view taken along the line CC of FIG. 5;

[Explanation of symbols]

11 bimetal, 11a caulking hole, 11d positioning hole, 12 conducting conductor, 12a caulking hole, 12b
Projections, 13 rivets.

Claims (3)

[Claims] 1. An overcurrent tripping bimetal is overlapped with one end of a current-carrying conductor, and caulked with a rivet penetrating a caulking hole formed in the overlapped portion. A bimetal fixing structure for a circuit breaker, wherein a female screw is formed in the caulking hole, wherein the bimetal is electrically connected to the bimetal via the fixing member. 2. The bimetal fixing structure for a circuit breaker according to claim 1, wherein a portion where one end of the overcurrent tripping bimetal is overlapped on the current-carrying conductor is crimped with one rivet. 3. A projection is provided on one of the overlapping portions of the conducting conductor and the overcurrent tripping bimetal, and a positioning hole is formed on the other of the overlapping portion so that the projection is fitted. A bimetal fixing structure for a circuit breaker according to claim 1 or 2.