Overload trigger

Abstract

The utility model relates to the technical field of power components, in particular to an overload trigger. According to the technical scheme, the temperature-sensitive bimetallic strip comprises a temperature-sensitive bimetallic strip body and a trigger pin, an overload deformation part is arranged in the middle of the temperature-sensitive bimetallic strip body, the trigger pin is arranged above the overload deformation part in the middle of the temperature-sensitive bimetallic strip body through an insulating layer in a stacked mode, and an open hole is formed in the position, corresponding to the overload deformation part, of the insulating layer. The beneficial effects are that when the circuit connected with the thermosensitive bimetallic strip is overloaded, the overload deformation part deforms due to overhigh temperature and contacts with the trigger pin, so that the overload current is led out through the trigger pin, the overload protection function is realized, and the overload protection function is realized after the circuit is recovered to be normal and the overload deformation part is recovered to be normal. The overload trigger can automatically recover to a normal conduction state, and cannot generate electric arc to damage the overload trigger when the protection is triggered and the normal conduction is recovered.

Description

Technical Field

[0001] The utility model relates to the technical field of power components, in particular to an overload trigger. Background Art

[0002] An overload trigger is a component used in power systems to detect overloads on lines and trigger protection actions when overloaded. In some circuit systems, the overload trigger is required to automatically restore the normal conduction state when the line returns to normal after the line overload triggers the protection action, without the need for manual restoration of conduction. The current overload triggers that can be automatically restored are of the on-off type, that is, when the line is overloaded, the circuit is disconnected by the deformation of the bimetallic strip, and when it returns to normal, the bimetallic strip returns to its original shape to restore the circuit conduction. The disadvantages of this type of overload trigger are that it is large in size and high in cost, and in the overload state, the line is directly disconnected by the deformation of the bimetallic strip, which will generate an arc that damages some components in the overload trigger, resulting in a short service life. Utility Model Content

[0003] The utility model aims to provide an overload trigger, in particular to provide an overload trigger which can automatically restore a normal conducting state and does not generate an arc during the triggering process.

[0004] To achieve the above-mentioned purpose, the utility model adopts the following technical scheme: an overload trigger, comprising a thermistor bimetal strip and a trigger pin, both ends of the thermistor bimetal strip are provided with connecting terminals for connecting the thermistor bimetal strip to the circuit, an overload deformation portion is provided in the middle of the thermistor bimetal strip, the trigger pin is stacked through an insulating layer and arranged above the overload deformation portion in the middle of the thermistor bimetal strip, and an opening is provided on the insulating layer at a position corresponding to the overload deformation portion.

[0005] Specifically, an insulating packaging part is arranged outside the thermistor bimetallic strip, the trigger pin and the insulating layer for packaging and fixing.

[0006] Specifically, the overload deformation portion is cut out from the middle of the thermosensitive bimetallic strip and is integrally connected to the thermosensitive bimetallic strip.

[0007] The beneficial effect of the utility model is that an overload deformation part is arranged in the middle position of the thermosensitive bimetallic strip, and a trigger pin is arranged on the thermosensitive bimetallic strip through an insulating layer. When an overload occurs in a circuit to which the thermosensitive bimetallic strip is connected, the overload deformation part will be deformed due to excessive temperature and contact the trigger pin, so that the overload current is conducted out through the trigger pin, thereby realizing the overload protection function. After the circuit returns to normal and the overload deformation part returns to normal, the normal conduction state can be automatically restored. At the same time, no arc will be generated to damage the overload trigger when the protection is triggered and the normal conduction is restored. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Attached Figure 1 This is a diagram of the overall structure of the overload trigger after assembly in the embodiment;

[0009] Attached Figure 2 For attachment Figure 1 A-A' section view;

[0010] Attached Figure 3 1 is a state diagram of the overload trigger split from top to bottom in the embodiment. DETAILED DESCRIPTION

[0011] Example 1, reference Figure 1-3 An overload trigger includes a thermal bimetallic strip 1 and a trigger pin 2. Both ends of the thermal bimetallic strip 1 are provided with connecting terminals for connecting the thermal bimetallic strip 1 to a circuit. An overload deformation portion 11 is provided in the middle of the thermal bimetallic strip 1. The trigger pin 2 is stacked and arranged above the overload deformation portion 11 in the middle of the thermal bimetallic strip 1 through an insulating layer 3. An opening 31 is provided on the insulating layer 3 at a position corresponding to the overload deformation portion 11.

[0012] In this embodiment, the connection terminals provided at both ends of the thermistor bimetal strip 1 are used to connect the thermistor bimetal strip 1 to the circuit, and the trigger pin 2 is connected to the ground wire through a current limiting resistor. When an overload occurs in the circuit to which the thermistor bimetal strip 1 is connected, the current flowing through the thermistor bimetal strip 1 also increases, and the temperature rises. The overload deformation portion 11 provided in the middle of the thermistor bimetal strip 1 deforms and bends after the temperature rises, and contacts the trigger pin 2 through the opening 31 on the insulating layer 3. The circuit to which the thermistor bimetal strip 1 is connected can release current to the ground wire through the trigger pin 3 and the current limiting resistor connected thereto, thereby triggering the overload protection of the circuit. When the circuit returns to normal, the temperature of the thermistor bimetal strip 1 drops and the shape of the overload deformation portion 11 returns to normal, thereby disconnecting the overload deformation portion 11 from the trigger pin 2, thereby automatically restoring the normal conduction state. Specifically, in this embodiment, an insulating packaging portion 4 is provided outside the thermistor bimetal strip 1, the trigger pin 2 and the insulating layer 3 for packaging and fixing. In this embodiment, the insulating layer between the thermosensitive bimetallic strip 1 and the trigger pin can be an insulating gasket or directly sprayed on the thermosensitive bimetallic strip or the trigger pin using an insulating material spray paint. Similarly, the insulating packaging part can also be insulated and packaged by spraying with insulating spray paint. Of course, it can also be packaged by an insulating packaging shell. In the drawings of this embodiment, in order to more clearly show the connection relationship between the various components, the insulating packaging part adopts a packaging shell, and the insulating layer adopts an insulating gasket.

[0013] Specifically, the overload deformation portion 11 in the present embodiment is cut out from the middle of the thermosensitive bimetal 1 and is integrally connected to the thermosensitive bimetal 1. The overload deformation portion 11 is cut out from the middle of the thermosensitive bimetal 1, so that the width of the overload deformation portion 11 in the middle of the thermosensitive bimetal 1 is narrower and its resistance value is also larger. Therefore, when the line is overloaded, the temperature of the middle overload deformation portion 11 is more likely to rise quickly and trigger the overload protection, and it is convenient to process the thermosensitive bimetal 1 and the overload deformation portion 11, thereby reducing the processing cost.

[0014] Of course, the above are only preferred implementations of the present utility model, and are not intended to limit the scope of use of the present utility model. Therefore, any equivalent changes made to the principles of the present utility model should be included in the protection scope of the present utility model.

Claims

1. An overload trigger, characterized in that: It includes a thermistor bimetallic strip and a trigger pin. Both ends of the thermistor bimetallic strip are provided with connecting terminals for connecting the thermistor bimetallic strip to the circuit. An overload deformation part is provided in the middle of the thermistor bimetallic strip. The trigger pin is stacked and arranged above the overload deformation part in the middle of the thermistor bimetallic strip through an insulating layer. An opening is provided on the insulating layer at a position corresponding to the overload deformation part.

2. An overload trigger according to claim 1, characterized in that: An insulating packaging part is arranged outside the thermosensitive bimetallic strip, the trigger pin and the insulating layer for packaging and fixing.

3. An overload trigger according to claim 1, characterized in that: The overload deformation portion is cut out from the middle of the thermosensitive bimetallic strip and is integrally connected with the thermosensitive bimetallic strip.

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