CN115513005A

CN115513005A - Thin bimetallic strip thermal protector

Info

Publication number: CN115513005A
Application number: CN202211348331.5A
Authority: CN
Inventors: 陈华东; 陈烨; 章巨丰
Original assignee: ZHEJIANG FUFENG ELECTRICAL APPLIANCES CO LTD
Current assignee: ZHEJIANG FUFENG ELECTRICAL APPLIANCES CO LTD
Priority date: 2022-10-31
Filing date: 2022-10-31
Publication date: 2022-12-23

Abstract

The invention discloses a thin thermal protector, which relates to the technical field of temperature type thermal protectors and comprises a plastic shell and a thermal protector assembly connected with a lead in the shell, wherein the thermal protector assembly comprises an insulating seat, a movable contact spring and a bimetallic strip. The insulating seat is formed by combining the static contact and plastic through injection molding processing. One end of the movable contact piece is riveted with a movable contact, two clamping jaws respectively extend out of two sides of the other end of the movable contact piece, reinforcing ribs are arranged at the bending positions of the clamping jaws and used for fixing the movable contact piece on the insulating base, a terminal used for being connected with a wire extends out of the movable contact piece in the direction away from the movable contact, and one side of the movable contact piece, which is riveted with the movable contact, serves as an action arm, so that the clamping jaws used for fixing, the terminal used for connecting the wire and the action arm all come out of the same body material. Through the design, the thermal protector is thinned. The thin thermal protector has the advantages of small volume, simple structure, good consistency and convenience for realizing automatic production.

Description

Thin bimetallic strip thermal protector

Technical Field

The invention relates to the technical field of temperature type thermal protectors, in particular to a thin thermal protector with bimetallic strips.

Background

With the continuous development of social economy, the living standard of people is continuously improved, various types of household appliances are rapidly developed, the requirements of people on the quality and performance of products are continuously improved, the safety of the products is continuously emphasized, and the application of a thermal protector serving as a safety protection element is also more and more extensive. At present, household appliances are developing towards miniaturization and multi-functionalization, and therefore, as a protection element of the household appliances, the thermal protector also has a demand for miniaturization. Such as a thermal protector for a motor on an electric curtain and a thermal protector for a small lithium battery on an electric product. The above-mentioned applications all require the thermal protectors to have a small thickness and width. The thin thermal protector in the prior art has the defects of complex structure and high difficulty in automatic production, and cannot meet the requirement of high-speed development of household appliances.

For example, a conventional thin thermal protector, such as CN2256164Y, is composed of a housing, a fixing base, a static contact, a bimetal with a contact, a fixing piece, a lead and a sealing compound. During assembly, the static contact piece, the bimetallic strip with the contact and the fixing piece are respectively arranged in the clamping grooves on the fixing seat and then arranged in the inner cavity of the shell, the thermal protector assembly with the lead is fixed together through the shell, and finally, the glue is sealed to complete the assembly of the thermal protector. Above-mentioned structure and mounting process, assembly error is big, leads to the thermal protector uniformity poor, and the qualification rate is low, and because the technology restriction, automated production is not convenient for, leads to production efficiency lower.

For another example, CN208570463U, the thermal protector is composed of a housing, a bracket, a terminal block, a bimetal, a spring plate, a lead, and a sealing compound. The elastic sheet is riveted and fixed on the support through a riveting column on the support. The bimetallic strip is arranged between the support and the elastic sheet, and the support is fixed on the lug plate by a self-provided clamping jaw. The thickness of the support is increased on the basis of the thickness of the elastic sheet and the bimetallic strip, so that the requirement for thinning the thermal protector is difficult to realize.

Disclosure of Invention

The invention aims to overcome the problems that the bimetallic strip thin type thermal protector in the prior art is poor in consistency and difficult to automatically produce, and provides the ultrathin bimetallic strip thermal protector which is convenient for automatic production and has the characteristics of good temperature consistency, small installation volume, simple manufacturing process and the like.

In order to achieve the purpose, the invention adopts the following technical scheme:

a bimetallic strip thermal protector comprises a shell, wherein the shell is made of plastic, an insulating seat, a movable contact strip and a bimetallic strip are arranged in the shell, and the insulating seat is formed by combining a static contact strip and plastic through injection molding. The static contact is made of a silver-copper composite belt. The bimetallic strip is positioned between the movable contact spring and the insulating seat.

One side of the movable contact piece, which is riveted with the movable contact, is used as an action arm, two clamping claws extend out of two sides of the other end of the movable contact piece respectively, the clamping claws are used for fixing the movable contact piece on the insulating base, and a terminal used for being welded with a lead extends out of the movable contact piece away from the movable contact. Therefore, the clamping jaw fixed with the insulating seat on the movable contact, the terminal for the welding wire and the action arm riveted with the movable contact all are made of the same material. The movable contact spring material is a treatment-free copper alloy, the movable contact spring made of the material meets the requirements of electrical conductivity and good elasticity required by acting arms, and the jaws made of the same body material meet the requirements of strength and plastic deformation of the jaws fixed on the insulating base through the design of specific reinforcing ribs.

Preferably, a convex point which is abutted with the bimetallic strip when the movable contact strip jumps is arranged at the middle position of the movable contact strip.

When the movable contact spring is used, the movable contact spring can be more smoothly bounced upwards through the salient points after the bimetallic strip is heated and bounced.

The insulating seat is formed by combining a static contact made of a silver-copper composite belt and plastic through injection molding, a silver layer covers the contact surface of one end of the static contact and the movable contact, a pin extends out of the other end of the static contact and is used for welding a lead, and a positioning column and a positioning groove are arranged on the upper portion of the side, close to the pin of the bonding wire, of the insulating seat, so that the bimetallic strip can be conveniently positioned and installed. Two clamping grooves are respectively formed on two sides of the lower part.

Preferably, the moving contact is a silver-copper composite contact.

Preferably, the wire is fixed to the housing by epoxy.

Preferably, the bimetallic strip is of a butterfly structure.

Drawings

The embodiments of the present invention will be further described with reference to the accompanying drawings, in which

Fig. 1 is a schematic structural view of the present invention.

Fig. 2 is an exploded view of the present invention with the housing removed.

Fig. 3 is an isometric view of the moving contact of the present invention.

Fig. 4 is an isometric view of the insulator base of the present invention.

Detailed Description

As shown in figure 1, the thin bimetallic strip thermal protector of the invention consists of a plastic shell (1), an insulating seat (2), a bimetallic strip (3), a movable contact (4), a static contact (5), a movable contact (6), a lead (7) and a sealant (8). The insulating seat is formed by combining the static contact and the plastic seat through injection molding processing. The static contact is a silver-copper composite strip, and a silver layer is coated at the contact position of the static contact and the movable contact on the movable contact. As shown in figure 3, one end of the movable contact piece is riveted with a movable contact, and two sides of the other end of the movable contact piece respectively extend out of two claws for fixing the movable contact piece on the insulating base. And a terminal used for being connected with a lead extends from the direction of the movable contact piece away from the movable contact, and one side of the movable contact piece riveted with the movable contact is used as an action arm. The clamping jaws for fixing the movable contact piece with the insulating seat, the terminals for welding the wires and the elastic arms riveted with the movable contact are made of the same body material, and the bimetallic strip is fixed between the insulating seat and the movable contact piece through the positioning columns and the positioning clamping grooves on the insulating seat in the figure 4. The bimetallic strip is pressed with a butterfly ring, and when the thermal protector reaches a set action temperature, the bimetallic strip overturns to bounce the action arm, so that a movable contact and a static contact on the movable contact are separated, and the overheating protection of an electric appliance is realized. The action arm of the movable contact spring, the clamping jaw for fixing the movable contact spring and the insulating seat and the terminal of the welding lead are made of the same body material. The design realizes the thinning of the thermal protector and meets the requirement of being convenient for automatic production.

Claims

1. An ultra-thin thermal protector, comprising: the device comprises a plastic shell (1), an insulating seat (2), a bimetallic strip (3), a movable contact strip (4), a static contact strip (5), a movable contact (6), a lead (7) and sealant (8). The silver-coated conducting wire is characterized in that the insulating seat (2), the bimetallic strip (3) and the movable contact strip (4) are fixed through clamping jaws of the movable contact strip, the bimetallic strip is located between the insulating seat and the movable contact strip, the movable contact strip and the movable contact (5) are fixedly riveted, and silver coatings are arranged at the corresponding contact positions of the static contact strip and the movable contact. The static contact piece and the movable contact piece are respectively connected with a lead-out wire (7), and the lead is fastened at the end part of the shell through the sealant (8).

2. The bimetallic thermal protector as in claim 1, wherein the insulator seat is formed by combining the static contact with plastic by injection molding. A positioning column and a positioning groove are arranged on the upper portion of one side, away from the static contact, of the insulating seat, and therefore installation of the bimetallic strip is facilitated. Two clamping grooves are respectively formed on two sides of the lower part, the static contact is made of silver-copper composite material.

3. The bimetallic strip thermal protector as claimed in claim 1, wherein a movable contact is riveted at one end of the movable contact piece, two clamping jaws respectively extend from two sides of one end of the movable contact piece away from the movable contact to fix the movable contact piece on the insulating base, reinforcing ribs are arranged at the bending positions of the clamping jaws and are formed by stamping through a die, a terminal for welding with a lead is extended from the direction of the movable contact piece away from the movable contact, and the clamping jaws extending from two sides of the movable contact piece, the lead terminal and an action arm riveted with the movable contact all extend from the same body. In order to meet the requirements of the scheme, the movable contact piece adopts a proper elastic conductive material to meet the requirement that the movable contact does not deform for a certain on-off frequency, and the requirements of the clamping jaw on the strength and the plastic deformation of the insulating seat are met through the specially designed reinforcing rib design.