CN212365857U - Precision-enhanced thermal protector - Google Patents

Abstract

The utility model discloses a hot protector of precision reinforcing, it includes casing upper cover, bimetallic strip and electrically conductive bottom plate, bimetallic strip fixed set up in the casing upper cover, including heating element and cambered surface movable contact spring, the contour line of cambered surface movable contact spring is the long circle and has concave cambered surface, simultaneously still the shaping has two fretwork strip-shaped grooves on the cambered surface movable contact spring, fretwork strip-shaped groove sets up along the central line symmetry on the cambered surface movable contact spring length direction to have the cambered surface to the crooked of central line on the cambered surface movable contact spring length direction; one end of the bimetallic strip is fixed on the surface of the conductive bottom plate, and the other end of the cambered movable contact strip is a suspension end, is provided with a movable contact and keeps contact with a fixed contact arranged on the inner side of the upper cover of the shell under the critical temperature through the movable contact. The utility model discloses the temperature control precision is high, and the stable performance, and can effectively improve the breaking distance of moving, stationary contact.

Description

Precision-enhanced thermal protector

Technical Field

The utility model relates to a thermal protector among the electrical protection components and parts technical field, concretely relates to thermal protector of precision reinforcing.

Background

The thermal protector, also called a micro overheat protector, is a commonly used thermal protection element, and is mainly used for performing overheat/overcurrent protection on various motors, PCB circuit boards, electric heating products and related equipment which need to generate heat when a battery runs, and the stability and safety of the circuit and the related equipment in running can be directly influenced by the performance of the thermal protector.

Common thermal protector mainly comprises casing, moving plate subassembly and static piece among the prior art, its moving plate subassembly is as the work unit, for the bimetallic strip structure, at least one is the temperature sensitive elastic alloy material in its bimetallic strip structure, including an cambered surface sheetmetal in the bimetallic strip structure, this temperature sensitive cambered surface sheetmetal one end is fixed, and the other end hangs, and set up the moving contact at the end that hangs, behind circular telegram to critical temperature state, temperature sensitive elastic alloy material warp the bending, thereby make the bimetallic strip structure realize the power-off protection to consumer in moving contact position separation. However, the temperature-sensitive cambered metal sheet is usually an oblong or butterfly cambered metal sheet, the deformation range of the overhanging end of the cambered metal sheet with the structure is small, the fixed end of the cambered metal sheet is usually fixed by adopting a rivet, welding or screwing mode, and the deformation of the cambered metal sheet is not enough to separate a moving contact and a static contact when the temperature reaches the critical temperature after the cambered metal sheet is used for a period of time, so that the sensitivity is reduced.

Disclosure of Invention

The technical problem solved by the utility model is to provide a hot protector of precision reinforcing to solve the defect in the above-mentioned technical background.

The utility model provides a technical problem adopt following technical scheme to realize:

a precision-enhanced thermal protector comprises a shell upper cover, a bimetallic strip and a conductive base plate, wherein the shell upper cover is connected with a first external lead, the conductive base plate is connected with a second external lead, the bimetallic strip is fixedly arranged in the shell upper cover and comprises a heating piece attached to the upper surface of the conductive base plate and a cambered movable contact piece arranged on the surface of the heating piece, the contour line of the cambered movable contact piece is in a long circle shape and is provided with a concave cambered surface, two hollowed-out strip-shaped grooves are formed in the cambered movable contact piece, and the hollowed-out strip-shaped grooves are symmetrically arranged along the center line in the length direction of the cambered movable contact piece and are provided with cambered surfaces bent towards the upper center line in the length direction of the cambered movable contact piece; one end of the bimetallic strip is fixed on the surface of the conductive bottom plate, and the other end of the cambered movable contact strip is a suspension end, is provided with a movable contact and keeps contact with a fixed contact arranged on the inner side of the upper cover of the shell under the critical temperature through the movable contact.

As further limited, the shell upper cover and the conductive bottom plate are respectively connected with a wire pin, the wire pin is a hoop, a tooth groove is arranged on the inner side of the hoop, and the wire is arranged behind the wire pin and clamped with the hoop to enable the tooth groove to be embedded into the wire, so that the wire assembly is completed.

As a further limitation, the fixing manner of the bimetal at the fixed end and the surface of the conductive base plate is screw thread fixing or rivet punching fixing.

As a further limitation, the outer surface of the conductive base plate is wrapped with a layer of insulating material, the insulating material is a polyimide film or mica insulating paper, and a reserved opening is reserved in the insulating material at a position corresponding to the projection of the bimetallic strip.

As further limitation, the length of the hollow strip-shaped groove is 3/4-4/5 of the length of the cambered movable contact piece.

As a further limitation, the hollowed-out strip-shaped groove is arranged at the position, corresponding to the width of the 1/5 cambered movable contact piece, of the outer contour line of the cambered movable contact piece, the width of the hollowed-out strip-shaped groove is variable, and the width of the hollowed-out strip-shaped groove is continuously increased from two ends to the middle.

And as a further limitation, the radian corresponding to the concave cambered surface of the part of the cambered movable contact piece corresponding to the outer sides of the two strip-shaped grooves is greater than the radian corresponding to the concave cambered surface of the part between the two strip-shaped grooves.

Has the advantages that: the utility model relates to a hot protector of precision reinforcing is through carrying out institutional advancement to cambered surface movable contact spring, make it have and have better temperature sensing performance than traditional butterfly or long circle cambered surface movable contact spring, make transshipping appear when the circuit, when faults such as short circuit, can the cambered surface movable contact spring can the temperature sensing sooner and produce deformation under the temperature sensing condition of the same piece that generates heat, simultaneously the cambered surface movable contact spring under this structural feature also has the deformation space bigger than traditional butterfly or long circle cambered surface movable contact spring, make to move, move when the separation that the stationary contact can be faster, the separation distance between the stationary contact is also bigger, make the formation of opening circuit more thoroughly.

Drawings

Fig. 1 is a schematic structural diagram of a preferred embodiment of the present invention.

Fig. 2 is a schematic structural view of the cambered movable contact piece in fig. 1.

Wherein: 1. a lead pin; 2. a housing upper cover; 3. a conductive chassis; 4. mica insulation paper; 5. reserving an opening in the mica insulating paper; 6. a stationary contact; 7. a movable contact; 8. a cambered surface movable contact piece; 9. a heat generating sheet; 10. riveting a rivet; 11. an outer buckling edge; 12. hollowing out the strip-shaped groove; 13. the reverse extension line of fretwork strip groove.

Detailed Description

In order to make the technical means, creation features, achievement purposes and functions of the present invention easy to understand and understand, the present invention is further explained by combining with the specific drawings.

Referring to fig. 1 and 2, in the present embodiment, the thermal protector includes a housing upper cover 2, a bimetal, and a conductive bottom plate 3, wherein the conductive bottom plate 3 is wrapped with a layer of mica insulation paper 4 during assembly, and outer fastening edges 11 are disposed on two sides of the housing upper cover 2, and after the conductive bottom plate 3 is wrapped with the mica insulation paper 4, the housing upper cover 2 seals the bimetal disposed on the surface of the conductive bottom plate 3 from the upper portion, and is fastened by the outer fastening edges 11 on two sides for position and structure fixing. Simultaneously, it has a wire pin 1 respectively to set up at casing upper cover 2 and electrically conductive bottom plate 3 same end, this wire pin 1 is a staple bolt structure, and be equipped with the tooth's socket in the hoop inboard of this staple bolt structure, first outside wire and second outside wire are inserting behind wire pin 1 that casing upper cover 2 is connected and the wire pin 1 that electrically conductive bottom plate 3 is connected respectively, press from both sides the staple bolt structure of tight wire pin 1 through dedicated anchor clamps, can make and accomplish the wire assembly in the tooth's socket embedding wire.

In this embodiment, electrically conductive bottom plate 3 is a metal material piece, its upper surface is provided with bimetallic strip, mica insulated paper 4 is provided with mica insulated paper at bimetallic strip position and reserves trompil 5, so that the piece 9 that generates heat that lies in the lower part among the bimetallic strip laminates in the upper surface of electrically conductive bottom plate 3, and generate heat piece 9 is the plane sheetmetal, laminate on the upper surface of electrically conductive bottom plate 3, be cambered surface movable contact 8 on piece 9 upper portion that generates heat, cambered surface movable contact 8 and generate heat piece 9 are the different metal material pieces of material, constitute bimetallic strip jointly, and encapsulate in casing upper cover 2 through the outer limit 11 of detaining of casing upper cover 2 both sides.

The structure of the cambered surface movable contact piece 8 is shown in fig. 2, the whole outline of the cambered surface movable contact piece 8 is in a long circle shape and is provided with a concave cambered surface, two hollowed-out strip-shaped grooves 12 are symmetrically arranged at the width positions of the cambered surface movable contact piece corresponding to the two side edges of the long circle-shaped outer contour line 1/5 on the inner side of the long circle-shaped inner side of the cambered surface movable contact piece 8, the two hollowed-out strip-shaped grooves 12 are symmetrical arc-shaped grooves, the length of the two hollowed-out strip-shaped grooves is 3/4 of the length of the cambered surface movable contact piece 8, the cambered surface of the hollowed-out strip-shaped grooves 12 faces the inner side of the cambered surface movable contact piece 8, the width of the whole slotted hole gradually increases from two sides to the middle, and meanwhile, the radian.

The bimetallic strip is fixed on the right upper surface of the conductive bottom plate 3 by a riveting rivet 10 in a pressing way on the right side, the cambered movable contact 8 is provided with a concave cambered surface structure because of the concave cambered surface structure, the left side is a suspension end under the condition that the cambered movable contact is fixed on the right side, the movable contact 7 is arranged on the upper surface of the suspension end, the fixed contact 6 matched with the movable contact 7 is arranged on the inner side of the shell upper cover 2, the movable contact 7 and the fixed contact 6 are in a communicated state under the critical temperature of the thermal protector, therefore, the bimetallic strip combines the movable contact 7 and the fixed contact 6 to form a series circuit by the shell upper cover 2, the conductive bottom plate 3 and the heating strip 9 on the bimetallic strip, and when the temperature in the thermal protector is normal, the movable contact 7 and the fixed contact 6 are contacted together, and the circuit is conducted. When the temperature in the thermal protector is too high or the over-current on the heating piece 9 is too large, the cambered movable contact piece 8 bends inwards, so that the movable contact 7 and the fixed contact 6 are separated, and the circuit is powered off. When the temperature returns to the previous state, the heating sheet 9 returns to the previous temperature state again, so that the cambered movable contact sheet 8 is restored, the movable contact sheet 3 and the static contact sheet 2 are contacted together again, the circuit is conducted again, and the equipment overheating protection can be realized by the circulation of the process.

In this embodiment, this kind of structure of cambered surface movable contact spring 8 can make cambered surface movable contact spring 8 of fretwork strip groove reverse extension line 13 outside portion have independently and slightly be greater than the resilience force of cambered surface movable contact spring 8 of fretwork strip groove reverse extension line 13 inside portion, cambered surface movable contact spring 8 itself becomes two sets of heat reaction spring in other words, two sets of heat reaction spring independent action and influence each other, alone some take place thermal deformation can both make movable contact 7 and stationary contact 6 disconnection on the cambered surface movable contact spring 8, can effectively improve thermal sensitivity, and can be satisfying the interior of fretwork strip groove reverse extension line 13, when outer both sides all take place thermal deformation, effectively improve the disconnection interval between movable contact 7 and the stationary contact 6.

In another embodiment, the fixing mode of the bimetallic strip at the fixed end and the surface of the conductive base plate 3 can be replaced by punching and fixing the rivet through screwing and fixing threads, so that a more stable structural effect can be obtained, but a screwing process is additionally added; in addition, the mica insulation paper 4 may be replaced with a polyimide film.

The foregoing shows and describes the general principles, essential features, and advantages of the invention. It will be understood by those skilled in the art that these examples are for illustrative purposes only and are not intended to limit the scope of the present invention. Furthermore, it should be understood that various changes, modifications and/or alterations to the present invention may be made by those skilled in the art after reading the technical disclosure of the present invention, and all such equivalents may fall within the scope of the present invention as defined by the appended claims.

Claims (8)

1. A precision-enhanced thermal protector comprises a shell upper cover, a bimetallic strip and a conductive base plate, wherein the shell upper cover is connected with a first external lead, and the conductive base plate is connected with a second external lead; one end of the bimetallic strip is fixed on the surface of the conductive bottom plate, and the other end of the cambered movable contact strip is a suspension end, is provided with a movable contact and keeps contact with a fixed contact arranged on the inner side of the upper cover of the shell under the critical temperature through the movable contact.

2. The enhanced precision thermal protector according to claim 1, wherein the top cover of the housing and the bottom conductive plate are respectively connected with a wire connecting pin, the wire connecting pin is a hoop, and a spline is arranged inside the hoop, after the first/second external wires are inserted into the wire connecting pin, the hoop is clamped to embed the spline into the first/second external wires, thereby completing the wire assembly.

3. The enhanced accuracy thermal protector according to claim 1, wherein the bimetallic strip is fixed at the fixed end to the surface of the conductive base plate by screwing or riveting.

4. The enhanced accuracy thermal protector according to claim 1, wherein the conductive base plate is wrapped with a polyimide film or mica paper as an insulating material on its outer surface, and the insulating material has a predetermined opening at a position corresponding to the projection of the bimetal.

5. The thermal protector with the enhanced precision as claimed in claim 1, wherein the length of the hollowed-out strip-shaped groove is 3/4-4/5 of the length of the cambered moving contact piece.

6. The enhanced-precision thermal protector according to claim 1, wherein the hollowed-out strip-shaped groove is formed in a position, corresponding to 1/5 the width of the cambered movable contact piece, of the outer contour line of the cambered movable contact piece.

7. A thermal protector in accordance with claim 1, wherein the width of the hollow strip-shaped groove is variable and increases continuously from the ends to the middle.

8. A thermal protector according to claim 1 in which the curvature of the concave arc of the moving arc contact at the outer side of the two slots is greater than the curvature of the concave arc between the two slots.

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