CN213459577U

CN213459577U - Overcurrent thermal protector

Info

Publication number: CN213459577U
Application number: CN202022173150.6U
Authority: CN
Inventors: 徐良保; 沈冬明
Original assignee: Changshu Xin Duan Electric Co ltd
Current assignee: Changshu Xin Duan Electric Co ltd
Priority date: 2020-09-28
Filing date: 2020-09-28
Publication date: 2021-06-15
Anticipated expiration: 2030-09-28

Abstract

The application relates to an overcurrent thermal protector, including the outer utmost point of connecing of heating wire, transition connection spare, second, heating wire one end is connected with transition connection spare, and the heating wire other end is connected characterized by with the outer utmost point of connecing of second: the heating wire main body part is mapped on the middle part of the temperature sensing bimetallic strip. The electric heating wire is in a solenoid shape, the main body part of the electric heating wire is a solenoid part, a winding shaft of the electric heating wire is vertical or basically vertical to a connecting line between a moving contact and a lining nail on the temperature sensing bimetallic strip, and the solenoid part of the electric heating wire is arranged below the middle part of the temperature sensing bimetallic strip. The main body part of the electric heating wire is not mapped on the transition connecting piece and the second external electrode. The electric heating wire is a flat plate-shaped disc-shaped electric heating wire or a corrugated electric heating wire. The temperature sensing bimetallic strip has the advantages of reasonable design structure, high utilization rate of heating quantity of the heating wire, quick temperature sensing, excellent product performance, low cost and good safety.

Description

Overcurrent thermal protector

Technical Field

The present application relates to an overcurrent thermal protector, belonging to a component in the motor thermal protector, which is used for protecting overcurrent and overtemperature of a motor or other control circuit boards.

Background

At present, a motor is generally provided with a thermal protector which mainly plays the roles of overcurrent and overtemperature rise protection. When the motor is used, the thermal protector is tightly attached to the motor shell, when a large current flows through the motor, a heating element in the thermal protector instantly generates large heat to cause the bimetallic strip to bend and turn over, and the movable contact is disconnected, so that the protection effect of overload current is achieved; in addition, when the motor works for a long time due to some reason, the temperature of the motor shell is overhigh, and after heat generated by the heating element in the thermal protector is superposed, the bimetallic strip is heated, bent and overturned, the movable contact is disconnected, and the protection effect of overtemperature rise is achieved.

Chinese patent No. ZL200410098345.1 discloses an invention patent named "low current motor protector", which has the following main structure: the spiral electric heating wire is connected with the two separated metal shells by adopting spot welding, the metal bottom plate and the two separated metal shells are separated by using a high-temperature resistant insulating part, and after the parts are connected, a hot protector power-on loop is formed; specifically, the patent features include: the heater comprises a metal shell and a flange on the metal shell, wherein a first cover part and a second cover part which are separated from each other are arranged on the metal cover, at least one of the first cover part and the second cover part forms a circular arch structure, a heater is accommodated in the circular arch structure, and a gasket, namely a non-metal insulating part, is arranged between the metal shell and the metal cover. The above patent has the following disadvantages in practical use:

1. the solenoid-shaped electric heating wire in the prior art is parallel to the connecting line of the moving contact and the lining nail on the temperature sensing bimetal, and the length direction of the winding shaft of the electric wire is consistent with that of the temperature sensing bimetal. Because the turning and bending functions of the temperature sensing bimetallic strip are realized by the middle part of the temperature sensing bimetallic strip, the heating wire in the prior art only has the heating value of the middle part to act on the turning and bending of the temperature sensing bimetallic strip after heating, the heating values of the front part and the rear part of the rest heating wire have no effect on the turning and bending of the temperature sensing bimetallic strip, the conditions of low utilization rate of the heating value of the heating wire and waste of materials of the front part and the rear part of the heating wire exist, and the redundant heat is concentrated on the metal base, so that.

2. The spiral part (main heating part) of the solenoid-shaped electric heating wire is arranged in the groove of the metal shell and is arranged at the bottom of the metal shell, and the distance between the spiral part and the temperature sensing bimetallic strip is long, so that the temperature difference sensed by the temperature sensing bimetallic strip can be caused, the electric heating wire needs to generate more heating amount, the requirement on the electric heating wire is high, and the cost of the electric heating wire is increased.

Referring to fig. 1, which is a schematic structural diagram of patent ZL200410098345.1 in prior art 1, a temperature-sensing bimetal 2 is formed by punching at a middle part 2-1 of the temperature-sensing bimetal by using a forming punch, and the turning and bending functions of the temperature-sensing bimetal 2 after sensing temperature are realized by the middle part 2-1 of the temperature-sensing bimetal.

Referring to fig. 2, a moving contact 3 is welded at the tail end 2-3 of a temperature-sensing bimetallic strip 2, and the front end 2-2 of the temperature-sensing bimetallic strip is welded with a shell 1 through a lining nail 4; the coiling axis of the electric heating wire 6 is basically parallel to the connecting line a of the movable contact 3 and the lining nail 4. When the motor passes through a large current, the electric heating wire 6 generates heat, the heating wire heating value close to the middle part 2-1 of the temperature sensing bimetallic strip 2 can act on the overturning and bending of the temperature sensing bimetallic strip 2, the heating values of the front and the rear parts of the rest of the electric heating wires 6 have slow response to the overturning and bending of the temperature sensing bimetallic strip 2, the heating value of the electric heating wire 6 is wasted, and the corresponding electric heating wire material is also wasted.

Referring to fig. 3, a solenoid portion 6-1 (a main heating portion) of the solenoid-shaped heating wire 6 is installed in a groove of the metal case (8, 9) and is far away from the temperature sensing bimetal 2, so that the temperature sensing performance of the temperature sensing bimetal 2 is poor, the heating wire 6 needs to generate more heat, the requirement on the heating wire 6 is high, the safety is reduced, and the corresponding cost is increased.

Referring to fig. 4, fig. 5 are schematic diagrams of a thermal protector of prior art 2 (publication No. CN 207097767U); the heating wire 66 is wound around the axis substantially parallel to the line b connecting the movable contact 33 and the pin 44. When the motor passes a large current, the heating wire 66 generates heat, the heating wire 66 near the middle part 2-1 of the temperature sensing bimetal 2 generates heat to act on the overturning and bending of the temperature sensing bimetal 2, the heating values of the front and rear parts of the remaining heating wire 66 react slowly to the overturning and bending of the temperature sensing bimetal 2, the heating value of the heating wire 66 is wasted, and the corresponding heating wire material is also wasted.

The solenoid-shaped heating wire 66 the solenoid part 66-1 (the main heating part) is installed in the insulating base 88, and is far away from the temperature sensing bimetal 2, which causes the temperature difference sensed by the temperature sensing bimetal 2, the heating wire 66 needs to generate more heat, the requirement for the heating wire is high, the safety is reduced, and the corresponding cost is increased. The relationship of the disadvantages is substantially the same as described above.

Disclosure of Invention

The overcurrent thermal protector aims to overcome the defects in the prior art, has reasonable structural design, excellent product performance and low cost, fully utilizes the heat productivity of the heating wire, improves the performance of the product and saves the product cost.

The technical scheme adopted by the application for solving the technical problems is as follows: the utility model provides an overcurrent thermal protector, includes heating wire, transition connecting piece, the second external electrode, and heating wire one end is connected with transition connecting piece, and the heating wire other end is connected characterized by with the second external electrode: the heating wire main body (mainly heating) part is mapped (projected) at the middle part of the temperature sensing bimetallic strip and cannot be mapped to the two ends of the temperature sensing bimetallic strip, so that the heating wire main body part is mapped at the middle part of the temperature sensing bimetallic strip in a centralized manner, the heating amount is concentrated at the middle part of the temperature sensing bimetallic strip, the temperature sensing is fast, the required energy is less, the heat is less wasted on the two ends of the temperature sensing bimetallic strip, the transition connecting piece and the second external electrode, and the safety is improved.

Preferably, the heating wire described in the present application is in a solenoid shape, a main portion of the heating wire is a solenoid portion, a winding axis of the heating wire is perpendicular or substantially perpendicular to a connecting line between the moving contact and the lining nail on the temperature sensing bimetal, and the solenoid portion of the heating wire is located below a middle portion (working area) of the temperature sensing bimetal.

Preferably, the main body part of the heating wire is not mapped on the transition connecting piece and the second external electrode (the projections of the main body part of the heating wire on the upper and lower planes of the transition connecting piece and the upper and lower planes of the second external electrode are all outside the transition connecting piece and the second external electrode), the main body part of the heating wire is far away from the transition connecting piece and the second external electrode, the heat loss is less, the heat protector is not easy to generate heat, and the safety is good.

The heating wire described herein may also take other forms, such as a flat plate-like, disk-like heating wire or a corrugated heating wire, etc.

Compared with the prior art, the application has the following advantages and effects: the heating wire has the advantages of reasonable design structure, high utilization rate of heating value of the heating wire, quick temperature sensing of the temperature sensing bimetallic strip, excellent product performance, low cost and good safety.

Drawings

FIG. 1 is a schematic structural view of a temperature sensing bimetallic strip in a prior art motor thermal protector;

fig. 2 is a partial bottom view of prior art 1 (patent No. ZL 200410098345.1) with the first cover, the second cover, the stationary contact and the insulation liner removed for ease of illustration;

FIG. 3 is a schematic cross-sectional view of prior art 1;

FIG. 4 is a bottom view of prior art 2 (patent publication No. CN 207097767U);

FIG. 5 is a schematic cross-sectional view of prior art 2;

fig. 6 is an exploded view of the overcurrent thermal protector according to embodiment 1 of the present application;

FIG. 7 is a schematic view of a base assembly according to embodiment 1 of the present application;

FIG. 8 is a partial bottom view of example 1 of the present application with the transition piece, second external electrode, liner and insulation liner removed for ease of illustration;

FIG. 9 is a sectional view of the present application in example 1;

FIG. 10 is a schematic structural view of a base assembly according to embodiment 2 of the present application;

fig. 11 is a schematic structural diagram of a base assembly according to embodiment 3 of the present application.

Detailed Description

The present application will be described in further detail below with reference to the accompanying drawings by way of examples, which are illustrative of the present application and are not limited to the following examples.

Example 1:

referring to fig. 6, the overcurrent thermal protector of the present application includes a first external electrode 10, a temperature-sensing bimetal 20, a moving contact 30, a lining nail 40, an insulating paper 50, a heating wire 60, a stationary contact 70, a transition connector 80, and a second external electrode 90, where the first external electrode 10, the temperature-sensing bimetal 20, the moving contact 30, the transition connector 80, the heating wire 60, and the second external electrode 90 may be sequentially connected in series to form an electrical circuit, and may be disconnected when an overcurrent or an overheat occurs, thereby forming the overcurrent thermal protector of the present application.

Referring to fig. 7, one end of the heating wire 60 is connected to the transition connector 80, the other end of the heating wire 60 is connected to the second external electrode 90, and the stationary contact 70 is connected to the transition connector 80, thereby forming a base assembly 101 according to the present application.

Referring to fig. 8, the movable contact 30 is welded to the tail end 20-3 of the temperature-sensing bimetal 20, and the front end 20-2 of the temperature-sensing bimetal 20 is welded to the first external electrode 10 through the lining nail 40, thereby forming the housing assembly 102 of the present application. The connecting line C between the moving contact 30 and the lining pin 40 is substantially perpendicular to the winding axis of the heating wire 60, the solenoid portion 60-1 (the main heating portion) of the heating wire 60 is just below the middle portion (the working area) 20-1 of the temperature sensing bimetal 20, and the temperature sensing bimetal 20 can fully absorb the heating value of the heating wire 60. The heating wire 60 has a high utilization rate of heat generation, and the length (distance along the winding axis direction of the heating wire 60) of the solenoid part 60-1 of the heating wire 60 is relatively short, compared with the prior art, the heating wire has a high utilization rate, low cost and good safety.

Referring to fig. 6, 7 and 8, the base assembly 101, the housing assembly 102 and the insulating paper 50 of the embodiment of the present application are connected and assembled to form the overcurrent thermal protector of the present application. Therefore, the structure design of the temperature sensing bimetallic strip is reasonable, the heating wire is high in heat productivity utilization rate, the temperature sensing bimetallic strip senses the temperature quickly, the product performance is excellent, the cost is low, and the safety is good.

Referring to fig. 9, the solenoid portion 60-1 of the heating wire 60 is located between the transition connection member 80, the second external electrode 90 and the temperature sensing bimetal 20, and is close to the temperature sensing bimetal 20, when the heating wire 60 heats, the temperature sensing bimetal 20 can quickly sense the heat generated by the heating wire 20, and the temperature sensing bimetal 20 senses the temperature, so that the protector can quickly perform a protection function; in addition, since the solenoid portion 60-1 is not overlapped with the transition piece 80 and the second external pole 90 in the up-down direction or only overlapped with the edge portion, the distance between the solenoid portion 60-1 and the transition piece 80 and the second external pole 90 is far, so that heat is not easily concentrated on the transition piece 80 and the second external pole 90, and the safety of the embodiment of the present application is improved.

Compared with the prior art, the utility model, have following advantage and effect: the heating wire has the advantages of reasonable design structure, high utilization rate of heating value of the heating wire, excellent performance of the temperature sensing bimetallic strip temperature sensing block, low product cost and good safety.

Example 2:

referring to fig. 10, the heating wire 60a of the present embodiment is a plate-type heating wire, and the rest of the structure of the present embodiment is the same as or equivalent to that of embodiment 1, and will not be described again.

Example 3:

referring to fig. 11, the heating wire 60b of the present embodiment is a wire plate type, and the rest of the structure of the present embodiment is the same as or equivalent to that of embodiment 1, and will not be described again.

The above description is only illustrative of the structure of the present application; moreover, the names of the components of the present application may be different, and all equivalent or simple changes made according to the structure, characteristics and principles described in the present application are included in the protection scope of the present application.

Claims

1. The utility model provides an overcurrent thermal protector, includes heating wire, transition connecting piece, the second external electrode, and heating wire one end is connected with transition connecting piece, and the heating wire other end is connected characterized by with the second external electrode: the main heating part of the electric heating wire is mapped on the middle part of the temperature sensing bimetallic strip, the main heating part of the electric heating wire is not mapped on the transition connecting piece and the second external electrode, and the central shaft of the main heating part of the electric heating wire is vertical to the connecting line between the movable contact and the lining nail on the temperature sensing bimetallic strip.

2. An overcurrent thermal protector according to claim 1, wherein: the heating wire is in a solenoid shape, the main heating part of the heating wire is a solenoid part, and the solenoid part of the heating wire is arranged below the middle part of the temperature sensing bimetallic strip.

3. An overcurrent thermal protector according to claim 1, wherein: the electric heating wire is a flat plate-shaped disc-shaped electric heating wire.