JPS58140944A - Device for tripping circuit breaker - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a circuit breaker tripping device that converts circuit current into heat and opens the circuit breaker by detecting a temperature rise due to the heat.

Conventionally, there has been a device of this type as shown in FIG. In the same figure, (1) is a fredle that constitutes a part of the trip mechanism that opens the circuit breaker. ■It is biased in the direction. (2) is a receiver rotatably supported by the pivot (3), one end of which is engaged with the fredle (1). (4) is the axis (5
), and the roller trigger (4) is provided with a roller (6) that engages with the receiver (2).

(7) is a latch fixed to the common release lever (8), the tip of which engages with the roller (IJ) (4).

The common trip lever (8) is rotatably mounted on a pivot (9). (10) is a heating resistor that is connected to a current-carrying part (not shown) and is heated in response to energization of the circuit breaker, and a circle is fixed to this heating resistor (10) and is heated from this. It is a bimetal that bends in the direction of the arrow (23), and has an adjustment screw (1) at its free end.
2) is installed.

Next, the operation in the above configuration will be explained.

Now, when an overcurrent continues to flow through the heating resistor (10) in Fig. 1, the bimetal 01) is heated by the heating resistor (10) and gradually bends in the direction of the arrow (23).
When it reaches a predetermined temperature, the tip of the adjusting screw (12) fully presses the common tripping lever (8) and rotates it in the direction of the arrow. As a result, the latch (7) and roller trigger (4)
), and the roller trigger (4) rotates about the pivot (5) in the direction of the arrow (support). In conjunction with this rotation, the receiver (2) rotates around the pivot (3) in the direction of the arrow (21), so the receiver (2) and the fredle (1) are disengaged and the fredle (1) ) moves rapidly in the direction of arrow (20) to trip the trip mechanism and open the circuit.

By the way, in the above configuration, the bimetal (11) is used and the bimetal (11) is bent to operate the tripping mechanism, but the displacement of the bimetal (11) necessary for this is In order to generate this force, it is necessary to raise the temperature of the heating resistor to around 200°C, which has the drawback of high power consumption.

In addition, since the Bimetal Co., Ltd. mentioned above gradually displaces in proportion to the temperature rise of the heating resistor (10), it is necessary to finely adjust the amount of displacement until the tripping device is activated, making assembly and adjustment unattended. It was a hindrance to

This invention was made to eliminate the above-mentioned conventional drawbacks, and by using a shape memory alloy, it is possible to perform the tripping operation of the trip mechanism with less power consumption, and it is possible to perform assembly adjustment. An object of the present invention is to provide a circuit breaker tripping device that can be easily automated.

An embodiment of the present invention will be described below with reference to the drawings. Note that the same or equivalent parts as in FIG. 1 are given the same reference numerals and their explanations will be omitted. In Fig. 2, a convex portion (8a) is formed on the negative side of the common release lever (8), and a hole (8b) bored in this convex portion (8a).
The lever is slidably inserted between the pull-out rods. The upper end of this tripping rod (I3) has a collar portion (13a) that presses the convex portion (8a) to rotate the common tripping lever (8).
), and a flange (13b) to which an overcurrent sensor (14) made of a shape memory alloy inserted between the heating resistor (10) and the heating resistor (10) is fixed is provided at the lower end.

The overcurrent sensor (14) is made of a shape memory alloy having a composition of, for example, Zu (27% by weight) - AI (8.7% by weight) - Cu (the balance), and has a wire rod with a diameter of 10 m and a wire diameter of 1 g. It is wound into a coil shape 8 to 4 times, and when heated to about 70° C., it rapidly contracts and displaces. The upper end of this overcurrent sensor circle is the tripping lever (13), and the lower end is the heating resistor (13).
10).

Next, the operation of the above configuration will be explained.

When an overcurrent continues to flow through the heating resistor (no) in FIG. 2, the temperature of the heating resistor (10) increases as shown in FIG. 8. Here, the vertical axis in FIG. 8 indicates temperature, and the horizontal axis indicates time, and the relationship with each circuit current value is expressed. At this time, when the heating resistor side reaches 100°C, the overcurrent sensor (1 (a)) made of shape memory alloy receives heat from the heating resistor (10) and rapidly displaces in the contraction direction (5). As a result, the tripping rod (13) moves downward and the collar (13a) pushes the protrusion (8a).This causes the common tripping lever (8) to pivot (9). Since it rotates around the center, the circuit breaker is tripped.

By the way, the overcurrent sensor (14) is connected to the heating resistor (1
0) reaches 100℃, the shape memory alloy of the tab suddenly displaces when the temperature reaches about 70℃, so the heating resistor α0) is heated to a high temperature of around 200℃ as in the conventional example. The circuit breaker tripping device can be operated with less power consumption.

In addition, since shape memory alloys move and have extremely large forces due to displacement, there is no need to make precise adjustments using the adjustment screw (12) as in the case of using bimetallic material as shown in Figure 1. It is easy to automate and save labor.

As explained above, according to the present invention, by using a shape memory alloy, it is possible to perform the tripping operation of the trip mechanism with less power consumption, and it is possible to easily automate assembly and adjustment. A circuit breaker tripping device can be provided.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram showing a conventional circuit breaker tripping device, FIG. 2 is a schematic configuration diagram showing a circuit breaker tripping device according to an embodiment of the present invention, and FIG. 8 is the same embodiment. FIG. 3 is a characteristic diagram showing a time-temperature relationship using various current values in the heating resistance as parameters. Shout...Heating resistance, (14)...Sensor. Note that the same reference numerals in the figures indicate the same or corresponding parts. Agent Makoto Kuzuno (1 other person) (7) Fig. 1 Fig. 2 Fig. 3 Fig. 1--→] Written amendment to procedure (spontaneous) 4518 Showa edition January 2nd, Name of invention Circuit cutoff Device tripping device 3, person making the amendment 5, “Detailed description of the invention” column of the specification to be amended. 6. Contents of the amendment (2)

Claims (1)

[Claims] (1) Equipped with a heating resistor that is heated by energizing the circuit breaker, and a sensor that is heated and displaced by the heating resistor, and that displacement operates a lip mechanism to open a circuit. , the above-mentioned sensor is a circuit breaker tripping device made of a shape memory alloy that is displaced when a predetermined temperature is reached.