Heat protector structure capable of enhancing firmness

Abstract

The utility model relates to a heat protector structure capable of enhancing firmness, which comprises a surface cover, an insulating base, a movable contact piece, a fixed contact piece, a bimetallic strip, a first terminal and a second terminal, the surface cover and the insulating base are buckled and fixed, the movable contact piece is clamped between the surface cover and the insulating base, and the fixed contact piece is clamped between the surface cover and the insulating base. The ultrasonic switch is characterized in that a third ultrasonic groove and a third ultrasonic bulge which are buckled and fixed with each other are arranged between the surface cover and the insulating base beside the movable contact piece. Therefore, through the technical means of adding the welding area between the surface cover and the insulating base beside the movable contact piece, the influence of high-frequency jumping of the movable contact piece on the welding area in an ultrasonic packaging link is counteracted, and the firmness of ultrasonic welding between the surface cover and the insulating base is ensured, so that the positioning of the movable contact piece on the heat protection device is more stable, and the reliability of the heat protection device is improved. And a heat protector product with stable and reliable quality is provided for customers.

Description

Technical Field

[0001] The utility model relates to the technical field of thermal protection, in particular to a thermal protector capable of enhancing firmness. Background Art

[0002] In 2021, the applicant applied to the State Intellectual Property Office of China for a utility model patent scheme with application number 202121066211.7 and the name "An assembly structure of a micro thermal protector". In this technical scheme, the thermal protector includes an insulating base, an insulating surface cover, a fixed contact piece, and a moving contact piece. The moving contact piece is positioned between the insulating base and the insulating surface cover, and the insulating base and the insulating surface cover are bonded together by ultrasonic welding. In order to strengthen the firmness of the positioning of the moving contact piece, a positioning protrusion is provided at one end of the insulating base, and the moving contact piece is sleeved on the positioning protrusion. The top surface of the positioning protrusion and the insulating surface cover are also bonded together by ultrasonic welding.

[0003] Although the above technical solution solves the problem of how to position and install the moving contact piece between the insulating base and the insulating cover, there are still some problems and shortcomings in the actual production process, which are reflected as follows:

[0004] Since the volume of the thermal protector is very small, slightly smaller than the fingernail of the human pinky finger, the moving contact piece cannot be fixed inside the thermal protector by conventional rivets, screws and other technologies. The moving contact piece can only be clamped between the face cover and the insulating base, and then the face cover and the insulating base are tightly connected together, so as to clamp and position the moving contact piece between the face cover and the insulating base. For miniature products such as thermal protectors, ultrasonic welding is commonly used in industry to tightly connect the face cover and the insulating base. The high-frequency vibration of the ultrasonic wave will cause local high temperature between the contact surfaces of the two plastics, so that the plastic in the welding area will melt. The melted plastic will solidify and form after cooling, thus forming a tight bond. In the above technical scheme, because the moving contact piece is movably nested on the insulating base, and the moving contact piece is relatively small, during the ultrasonic welding process, the high-frequency vibration of the ultrasonic wave will drive the moving contact piece to also have high-frequency vibration. During the cooling and solidification of the welding area, the moving contact piece is still vibrating due to inertia, and the welding area has not yet completely solidified. In addition, the welding area between the cover and the insulating base is very small, and the welding strength of the welding area is relatively small. Therefore, the vibration of the moving contact piece will easily cause cracks in the welding area, which will result in the failure to form a tight bond between the cover and the insulating base, and the failure to firmly position the moving contact piece, resulting in substandard product quality and a high rate of defective products. Since the moving contact piece cannot be firmly positioned between the cover and the insulating base, the moving contact piece is prone to loosening during the use of the thermal protector, which increases the probability of false operation, and cannot protect the circuit in a timely and accurate manner, making it impossible to ensure the safety of electricity use.

[0005] Therefore, in view of the aforementioned deficiencies of the existing thermal protector, the applicant believes that it is necessary to further improve the existing solution to enhance the stability of the installation and positioning of the moving contact piece, thereby improving the safety and service life of the thermal protector. Utility Model Content

[0006] The purpose of the utility model is to solve the above-mentioned problems and shortcomings, and to provide a thermal protector structure with enhanced firmness. By means of a technical means of adding a welding area between a surface cover located beside the moving contact piece and an insulating base, the influence of the high-frequency vibration of the moving contact piece on the welding area in the ultrasonic packaging link is offset, and the firmness of the ultrasonic welding between the surface cover and the insulating base is ensured, thereby making the positioning of the moving contact piece on the thermal protector more stable, and providing customers with thermal protector products with stable quality and reliability.

[0007] The technical solution of the utility model is achieved as follows: a heat protector structure with enhanced firmness, comprising a face cover, an insulating base, a moving contact piece, a fixed contact piece, a bimetallic strip, a first terminal and a second terminal, wherein the face cover is buckled and fixed with the insulating base, and the moving contact piece is sandwiched between the face cover and the insulating base, and is characterized in that a third ultrasonic groove and a third ultrasonic protrusion that are buckled and fixed with each other are also provided between the face cover and the insulating base located on the side of the moving contact piece.

[0008] Furthermore, the insulating base is provided with a clearance notch, and the insulating base at both sides of the clearance notch is also provided with a clamping protrusion, and the movable contact piece is provided with a clamping notch embedded with the clamping protrusion.

[0009] Furthermore, the third ultrasonic protrusion is arranged on the top surface of the clamping protrusion, and the third ultrasonic groove is correspondingly arranged on the bottom surface of the surface cover.

[0010] The beneficial effects of the utility model are as follows: the utility model increases the welding area between the surface cover and the insulating base because the third ultrasonic groove and the third ultrasonic protrusion that are interlocked and fixed are arranged between the surface cover and the insulating base on both sides of the clearance gap. In this way, in the process of ultrasonic welding and packaging the surface cover and the insulating base, the interference caused by the high-frequency beating of the moving contact piece will be distributed to multiple welding areas, thereby offsetting its negative impact, reducing the probability of cracks in the welding area, and ensuring that each welding area can be firmly welded together; the setting of multiple welding areas also enhances the tight connection strength between the surface cover and the insulating base, so that the moving contact piece is more firmly positioned between the surface cover and the insulating base. Therefore, the positioning of the moving contact piece on the thermal protector is more stable and not easy to deviate, ensuring that the thermal protector has stable and reliable temperature control quality, providing users with thermal protector products with higher safety performance and longer service life, and improving the reliability and credibility of manufacturers. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 This is an overall top view of the heat protector structure with enhanced firmness according to the utility model.

[0012] Figure 2 This is a schematic diagram of the internal structure of the heat protector structure with enhanced firmness according to the utility model.

[0013] Figure 3 The bottom view is of the movable contact piece of the thermal protector structure with enhanced firmness according to the utility model.

[0014] Figure 4 The utility model is a schematic diagram of the structure of the fixed contact piece of the thermal protector structure with enhanced firmness.

[0015] Figure 5 The utility model is a schematic diagram of the top view of the insulating base of the thermal protector structure with enhanced firmness.

[0016] Figure 6 The utility model is a schematic diagram of the bottom view of the insulating base of the thermal protector structure with enhanced firmness.

[0017] Figure 7 It is a cross-sectional view of the heat protector structure with enhanced firmness according to the utility model. Implementation

[0018] In order to enable those skilled in the art to better understand the technical solution of the present invention, the technical solution of the present invention is clearly and completely described below in conjunction with the accompanying drawings of the present invention.

[0019] like Figure 1 , Figure 2As shown, a heat protector structure with enhanced firmness of the utility model comprises a cover 1, an insulating base 2, a moving contact piece 3, a fixed contact piece 4, a bimetallic strip 5, a first terminal 6 and a second terminal 7. The cover 1 is fixedly engaged with the insulating base 2, and the moving contact piece 3 is sandwiched between the cover 1 and the insulating base 2. A first ultrasonic groove 18 and a first ultrasonic protrusion 28 that are engaged with each other are provided between the edges of the cover 1 and the insulating base 2. The first ultrasonic groove 18 and the first ultrasonic protrusion 28 melt under ultrasonic high-frequency vibration, and then cool and solidify into one body, thereby tightly combining the cover 1 and the insulating base 2. In order to achieve the purpose proposed by the utility model, a third ultrasonic groove 17 and a third ultrasonic protrusion 27 that are engaged with each other are also provided between the cover 1 and the insulating base 2 located on the side of the moving contact piece 3. In this way, in the process of ultrasonic welding packaging, the interference caused by the high-frequency beating of the moving contact piece 5 will be distributed to multiple welding areas, thereby offsetting its negative impact, avoiding cracks in the welding area, and ensuring the welding strength of the welding area; the setting of multiple welding areas also enhances the tight connection strength between the cover 1 and the insulating base 2, so that the moving contact piece 5 is more firmly positioned between the cover 1 and the insulating base 2. Therefore, the positioning of the moving contact piece 3 on the thermal protector is more stable and not prone to displacement, ensuring that the thermal protector has stable and reliable temperature control quality, providing users with thermal protector products with higher safety performance and longer service life, and improving the reliability and credibility of manufacturers.

[0020] like Figure 2 , Figure 5 As shown, the insulating base 2 is provided with a clearance notch 23, and the insulating base 2 on both sides of the clearance notch 23 is also provided with a clamping protrusion 25, and the movable contact piece 3 is provided with a clamping notch 35 embedded with the clamping protrusion 25. Since the clamping notch 35 surrounds the clamping protrusion 25 from three directions, the mutual clamping force between the two is relatively large, so that the movable contact piece 3 can be clamped more tightly on the insulating base 2. The third ultrasonic protrusion 27 is arranged on the top surface of the clamping protrusion 25, and the third ultrasonic groove 17 is correspondingly arranged on the bottom surface of the cover 1. In this way, the clamping protrusion 25 and the cover 1 can be tightly combined together by ultrasonic welding, thereby enhancing the firmness of the positioning of the movable contact piece 3.

[0021] like Figure 2 , Figure 5 As shown, the third ultrasonic protrusion 27 is arranged on the inner side of the first ultrasonic protrusion 28, and the third ultrasonic groove 17 is arranged on the inner side of the first ultrasonic groove 18. This structure can make the appearance of the thermal protector simple and concise, except for the necessary wiring terminals exposed outside the thermal protector, other components are located inside the thermal protector. In this way, the thermal protector is not easy to hide impurities such as dust during the manufacturing, assembly and use process, nor is it easy to be disturbed by the outside world, which ensures the stability and accuracy of the thermal protector.

[0022] like Figure 2 As shown, the said clearance notch 23 is also provided with a buckle column 24, and the said moving contact piece 3 and the face cover 1 are respectively provided with a through hole 34 and a buckle groove 14 which cooperate with the buckle column 24. The moving contact piece 3 is fixed on the insulating base 2 by the nesting of the through hole 34 and the buckle column 24, and the cooperation of the buckle column 24 and the buckle groove 14 makes the insulating base 2 and the face cover 1 connected together. Therefore, a positioning place for the moving contact piece 3 is also formed here, and the positioning firmness of the moving contact piece 3 is further improved. A second ultrasonic protrusion 29 is provided on the top surface of the said buckle column 24, and a second ultrasonic groove 19 which is embedded with the second ultrasonic protrusion 29 is correspondingly provided in the said buckle groove 14. In this way, the buckle column 24 and the buckle groove 14 can also be tightly combined together by ultrasonic welding, thereby further enhancing the positioning firmness of the moving contact piece 3.

[0023] like Figure 2 , Figure 3 As shown, the insulating base 2 is provided with a mounting groove 21, a transition portion 38 is further provided between the movable contact piece 3 and the first terminal 6, and a limiting convex portion 33 is respectively provided on both sides of the transition portion 38, and the clamping notch 35 and the through hole 34 are respectively provided on the transition portion 38; and a bending portion 32 is further provided between the transition portion 38 and the first terminal 6. A movable contact point 36 is provided at the end of the movable contact piece 3, and a top convex column 37 is provided on the bottom surface of the movable contact piece 3 located inside the movable contact point 36. The transition portion 38 quickly and accurately positions the movable contact piece 5 on the insulating base 2 through the clamping notch 35, the through hole 34 and the limiting convex portion 33; at the same time, five action points are formed between the movable contact piece 3 and the insulating base 2, namely, the connection between the through hole 34 and the buckling column 24, the connection between the clamping notch 35 on both sides and the clamping convex portion 25, and the connection between the limiting convex portion 33 on both sides and the inner walls of the mounting groove 21, so that the movable contact piece 3 can be more firmly positioned on the insulating base 2. During the assembly process, since these five points of action work at the same time, the moving contact piece 3 can be connected to the insulating base 2 relatively quickly and firmly; in the ultrasonic welding packaging process, these five points of action can absorb a part of the high-frequency vibration energy of the ultrasonic wave, effectively reducing the intensity of the high-frequency beats of the moving contact piece 3, thereby offsetting the negative impact of the high-frequency beats of the moving contact piece 3 on the welding area, ensuring the firmness of the ultrasonic welding between the cover 1 and the insulating base 2, thereby making the positioning of the moving contact piece 3 on the thermal protector more stable.

[0024] like Figure 4As shown, the fixed contact piece 4 is connected to the second terminal 7 as a whole, a bending transition portion 43 is provided between the fixed contact piece 4 and the second terminal 7, and a fixed contact point 46 is provided on the inner end of the second terminal 7 located above the bending transition portion 43; recesses 412 embedded with the insulating base 2 are provided on both sides of the inner end of the second terminal 7, and a bite hole 411 engaged with the insulating base 2 is provided on the inner end of the second terminal 7. In this way, when the fixed contact piece 4 is placed in the mold for glue injection, the bite hole 411 and the recess 412 form an integrated structure with the insulating base 2, so that the embedded strength between the fixed contact piece 4 and the insulating base 2 is greater.

[0025] like Figure 4 , 5 As shown in FIGS. 6 and 7, the fixed contact piece 4 also has convex edges 451 formed by bending upwards on both sides, and the bottom surface of the insulating base 2 is also provided with a groove 210, and the fixed contact piece 4 is embedded in the groove 210 and the convex edges 451 on both sides are correspondingly embedded in the two sides of the bottom surface of the insulating base 2. The end of the fixed contact piece 4 is also provided with an embedded end portion 42 with a through hole 421, and the embedded end portion 42 is correspondingly embedded in the insulating base 2; a bent transition portion 43 is also provided between the embedded end portion 42 and the end of the fixed contact piece 4. In this way, the through hole 421 can also form an integrated structure with the insulating base 2 during the glue injection process, thereby increasing the embedded strength between the fixed contact piece 4 and the insulating base 2. The convex edges 451 on both sides of the fixed contact piece 4 are embedded in the bottom surface of the insulating base 2, and the bent transition portion 43 is also embedded in the insulating base 2, which increases the contact area between the fixed contact piece 4 and the insulating base 2, so that the fixed contact piece 4 is more fully wrapped inside the insulating base 2, so that the fixed contact piece 4 and the insulating base 2 are more tightly and firmly combined. In addition, since the fixed contact piece 4 is made of metal material, its mechanical strength is relatively large, and the integration of metal material can also enhance the mechanical strength of the insulating base 2.

[0026] like Figure 5 , 6 As shown in 7, due to the setting of the bending transition part 43, the bottom surface of the fixed contact piece 4 can be flush with the bottom surface of the insulating base 2, so that the fixed contact piece 4 located between the two bending transition parts 43 forms a concave cavity for installing the PTC chip 8, and the insulating base 2 is correspondingly provided with a set hole 211, so that the PTC chip 8 can contact the bimetallic strip 5. In this way, the fixed contact piece 4 is directly connected to the external circuit. Since the fixed contact piece 4 is metal, its heat transfer speed is faster, so it can transfer the temperature on the circuit to the PTC chip more quickly, so that the bimetallic strip 5 can act faster to lift the moving contact piece 3 and disconnect the circuit. In addition, since the fixed contact piece 4 is nested in the groove 210, the structure of the thermal protector is more compact and the overall size can be made thinner, so that the thermal protector of the utility model is more in line with the specification requirements of small and micro electrical appliances and has a wider range of applications.

[0027] like Figure 2 , Figure 5 , Figure 7 As shown, a fixed contact platform 26 is provided on the insulating base 2, a fixed contact 46 is fixed on the fixed contact platform 26, and the moving contact 36 and the fixed contact 46 are separated or contacted at the fixed contact platform 26. A clearance groove 11 is provided on the cover 1, and a mounting groove 21 is provided on the insulating base 2, so that there is enough space inside the thermal protector for the moving contact piece 3 and the bimetallic strip 5 to move, thereby ensuring the normal operation of the electric protector.

[0028] In order to facilitate the accurate positioning of the cover 1 and the insulating base 2 more quickly during the assembly process, as shown in FIG. Figure 2 As shown, positioning bosses 12 are respectively provided on both sides of one end of the bottom surface of the cover 1, and a positioning hole 22 is correspondingly provided on one end of the top surface of the insulating base 2. In this way, during assembly, the positioning bosses 12 are inserted into the positioning holes 22, and the cover 1 can be covered on the insulating base 2, which is convenient and quick, and the cover 1 can be covered on the insulating base 2 more accurately.

[0029] In addition, it should be noted that, for the convenience of description, the terminal is divided into a first terminal 6 and a second terminal 7 in the present application. In actual production and application, the functions of the two terminals are the same, both for connecting to an external circuit. The cover 1 and the insulating base 2 are tightly combined together by ultrasonic welding. The positions of the ultrasonic protrusions and the ultrasonic grooves can be set on the cover or the insulating base respectively according to actual conditions, and are not limited to the setting method in the embodiment of the present utility model.

Claims

1. A heat protector structure with enhanced firmness, comprising a cover (1), an insulating base (2), a movable contact piece (3), a fixed contact piece (4), a bimetallic strip (5), a first terminal (6) and a second terminal (7), wherein the cover (1) and the insulating base (2) are fastened and fixed, and the movable contact piece (3) is sandwiched between the cover (1) and the insulating base (2), and characterized in that: A third ultrasonic groove (17) and a third ultrasonic protrusion (27) which are fastened and fixed to each other are also provided between the surface cover (1) and the insulating base (2) located on the side of the movable contact piece (3).

2. The enhanced firmness heat protector structure according to claim 1, characterized in that: The insulating base (2) is provided with a clearance notch (23), and the insulating base (2) is provided with a clamping protrusion (25) on both sides of the clearance notch (23), and the movable contact piece (3) is provided with a clamping notch (35) embedded in the clamping protrusion (25).

3. The enhanced firmness heat protector structure according to claim 2, characterized in that: The third ultrasonic protrusion (27) is arranged on the top surface of the clamping protrusion (25), and the third ultrasonic groove (17) is correspondingly arranged on the bottom surface of the surface cover (1).

4. The enhanced firmness heat protector structure according to claim 2, characterized in that: A buckle-mounting column (24) is also provided on the clearance notch (23), and a through hole (34) and a buckle-mounting groove (14) which cooperate with the buckle-mounting column (24) are respectively provided on the movable contact piece (3) and the surface cover (1) in a relative manner.

5. The enhanced firmness heat protector structure according to claim 4, characterized in that: A second ultrasonic protrusion (29) is provided on the top surface of the buckle-mounting column (24), and a second ultrasonic groove (19) embedded in the second ultrasonic protrusion (29) is correspondingly provided in the buckle-mounting groove (14).

6. The enhanced firmness heat protector structure according to claim 1, characterized in that: A first ultrasonic groove (18) and a first ultrasonic protrusion (28) which are interlocked are also provided between the edges of the surface cover (1) and the insulating base (2); the third ultrasonic protrusion (27) is arranged on the inner side of the first ultrasonic protrusion (28), and the third ultrasonic groove (17) is arranged on the inner side of the first ultrasonic groove (18).

7. The enhanced firmness heat protector structure according to claim 4, characterized in that: A transition portion (38) is also provided between the movable contact piece (3) and the first terminal (6), and limiting protrusions (33) are respectively provided on both sides of the transition portion (38); the clamping notch (35) and the through hole (34) are respectively provided on the transition portion (38); and a bending portion (32) is also provided between the transition portion (38) and the first terminal (6).

8. The heat protector structure with enhanced firmness according to claim 1, characterized in that: The fixed contact piece (4) and the second terminal (7) are connected as a whole, a bent transition portion (43) is provided between the fixed contact piece (4) and the second terminal (7), and a fixed contact point (46) is provided on the inner end of the second terminal (7) above the bent transition portion (43); recesses (412) for engaging with the insulating base (2) are provided on both sides of the inner end of the second terminal (7), and an engaging hole (411) for engaging with the insulating base (2) is provided on the inner end of the second terminal (7).

9. The enhanced firmness heat protector structure according to claim 8, characterized in that: The fixed contact piece (4) also has convex edges (451) formed by integrally bending upwards on both sides, and the bottom surface of the insulating base (2) is also provided with a groove (210), the fixed contact piece (4) is embedded in the groove (210) and the convex edges (451) on both sides are correspondingly embedded in the two sides of the bottom surface of the insulating base (2).

10. The heat protector structure with enhanced firmness according to claim 9, characterized in that: The end of the fixed contact piece (4) is also provided with an embedding end (42) with a through hole (421), and the embedding end (42) is correspondingly embedded in the insulating base (2); and a bent transition portion (43) is also provided between the embedding end (42) and the end of the fixed contact piece (4).

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