Positive and negative temperature coefficient thermistor and bimetallic combination integrated protector

Abstract

The present invention relates to a positive and negative temperature coefficient thermistor and a bimetallic combination integrated protector, comprising a shell, the interior of the shell is a rectangular cavity with one side open, the rectangular cavity of the shell contains an upper terminal assembly and a lower terminal assembly, the upper terminal assembly is located above the lower terminal assembly; the upper terminal assembly is connected to the inner top wall of the rectangular cavity, the lower terminal assembly is connected to the inner bottom wall of the rectangular cavity, a fixing seat is provided between the upper terminal assembly and the lower terminal assembly, and the fixing seat is formed by injection molding. The integrated design of the bimetallic temperature sensing element and the thermistor chip facilitates installation, reduces installation complexity, and reduces installation labor costs.

Description

Technical Field

[0001] The invention belongs to the field of protectors, in particular to an integrated protector combining a positive and negative temperature coefficient thermistor with a bimetal. Background Art

[0002] In some electronic products such as new energy, medical equipment, smart home appliances, heating appliances, etc., overheat protection is used to provide power-off protection for products when overheating or overcurrent occurs. The current design has more significant drawbacks, specifically: in the existing technology, either a positive temperature coefficient, platinum resistance or negative temperature coefficient NTC temperature control is used alone - the induction temperature corresponds to the change in resistance, or a bimetallic temperature control switch is used alone - the deformation corresponds to the temperature, or the above are used separately and two are installed, resulting in complex installation and high cost, and different installation positions lead to different ambient temperatures and large temperature differences between the two, which leads to deviations in the timing of the two taking effect; the structure of the existing device is too complicated, such as the metal sheet and the sealing part are mostly fixed by bolts, and there is a problem of gradual failure due to mechanical fatigue of the bolts, resulting in the product being unable to be temperature calibrated before the shell is encapsulated, so the qualified rate of the finished product is low, the production efficiency is low, and the accuracy is poor. Therefore, a positive and negative temperature coefficient thermistor and a bimetallic combination integrated protector are proposed. Summary of the invention

[0003] The purpose of this section is to summarize some aspects of embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the specification abstract and the invention title of this application to avoid blurring the purpose of this section, the specification abstract and the invention title, and such simplifications or omissions cannot be used to limit the scope of the present invention.

[0004] In view of the following technical problems in the prior art: in the prior art, either a positive temperature coefficient, a platinum resistor or a negative temperature coefficient NTC temperature control is used alone - the resistance change corresponds to the induced temperature, or a bimetallic temperature control switch is used alone - the deformation corresponds to the temperature, or the above are used separately and two are installed, resulting in complex installation and high cost, and different installation positions lead to different ambient temperatures and large temperature sensing differences between the two, which leads to deviations in the timing of the two taking effect; the structure of the existing device is too complicated, for example, the metal sheet and the sealing part are mostly fixed by bolts, and there is a problem of gradual failure due to mechanical fatigue of the bolts, resulting in the product being unable to be temperature calibrated before being packaged in the shell, so the qualified rate of the finished product is low, the production efficiency is low, and the precision is poor.

[0005] In order to solve the above technical problems, the present invention provides the following technical solutions: a positive and negative temperature coefficient thermistor and a bimetallic combined integrated protector, comprising a shell, the interior of the shell is a rectangular cavity with one side open, an upper terminal assembly and a lower terminal assembly are accommodated inside the rectangular cavity of the shell, and the upper terminal assembly is located above the lower terminal assembly;

[0006] The upper terminal assembly is connected to the inner top wall of the rectangular cavity, the lower terminal assembly is connected to the inner bottom wall of the rectangular cavity, and a fixing seat is arranged between the upper terminal assembly and the lower terminal assembly, and the fixing seat is formed by injection molding;

[0007] The upper terminal assembly includes a moving contact, a bimetallic element and a temperature calibration sheet. The inner top wall of the rectangular cavity is face-to-face and abutted against the upper side of the temperature calibration sheet. The lower side of the temperature calibration sheet is provided with a bimetallic element, which is made of two metal sheets with different thermal expansion coefficients. The moving contact is provided on the lower side of the bimetallic element away from the end of the temperature calibration sheet.

[0008] A cover is provided on the side of the shell, and the cover and one side of the shell form a cavity with one end open. A temperature sensing chip is provided on the inner side of the cover, and a wire a and a wire b are connected to the temperature sensing chip. The wire a, the temperature sensing chip and the wire b are wrapped in epoxy glue, and the epoxy glue is located on the inner side of the cover;

[0009] A temperature calibration sheet deformation groove is provided at the bottom of one end of the temperature calibration sheet, the temperature calibration sheet deformation groove is a V-shaped groove, the depth of the temperature calibration sheet deformation groove is one fifth of the thickness of the temperature calibration sheet, the other end of the temperature calibration sheet is recessed downward to form an upper terminal connection convex ball point, the shape of the upper terminal connection convex ball point is hemispherical, and the upper terminal connection convex ball point is inserted into the bimetallic element;

[0010] The lower terminal assembly includes a stationary contact, and the movable contact is movably abutted against the stationary contact.

[0011] As a preferred technical solution for the integrated protector of the positive and negative temperature coefficient thermistor and the bimetal combination, the upper terminal assembly includes an upper terminal, the temperature calibration sheet is provided with an upper terminal at one end away from the bimetal element, the upper side of the upper terminal is inserted into the upper terminal connection convex point, and the bottom of the upper terminal is provided with a wire welding positioning claw;

[0012] As a preferred technical solution for the integrated protector of the positive and negative temperature coefficient thermistor and the bimetal combination, the lower terminal assembly includes a lower terminal, one end of which is provided with a wire welding positioning claw;

[0013] The wire welding positioning claw is connected to another wire.

[0014] The wire welding positioning claw is used for externally connecting the wire to connect the wire to the lower terminal assembly.

[0015] As a preferred technical solution for the positive and negative temperature coefficient thermistor and bimetallic combined integrated protector, a fixing seat connecting ring is installed in the middle of the upper side of the lower terminal, and a square groove is opened in the middle of the lower terminal, and the square groove cooperates with the fixing seat connecting ring;

[0016] The cast fixing seat extends into the square groove, and the fixing seat connecting ring is wrapped by the fixing seat, so that the lower terminal is fixedly connected with the inside of the shell.

[0017] As a preferred technical solution for the integrated protector of the positive and negative temperature coefficient thermistor and the bimetallic element, a wire is welded on the wire welding positioning claw, a temperature calibration plate bracket is provided at one end of the temperature calibration plate, and the lower side of the temperature calibration plate bracket is fixedly connected to the upper side of the bimetallic element;

[0018] The temperature calibration piece bracket strengthens the connection between the temperature calibration piece and the bimetallic element.

[0019] As a preferred technical solution for the integrated protector of the positive and negative temperature coefficient thermistor and the bimetal combination, a sealant is inserted into the opening of the rectangular cavity, the sealant seals the only opening of the rectangular cavity, and the sealant wraps the wire welding positioning claw;

[0020] The only opening of the rectangular cavity is sealed with a sealant.

[0021] As a preferred technical solution for the integrated protector of the positive and negative temperature coefficient thermistor and the bimetal combination, four connection bumps are provided on one side of the lower terminal, and the connection bumps are fixedly connected to the inner top wall of the rectangular cavity.

[0022] The beneficial effects of the positive and negative temperature coefficient thermistor and bimetallic integrated protector of the present invention are as follows:

[0023] The integrated design of bimetallic temperature sensing element and thermistor chip facilitates installation, reduces installation complexity, and reduces installation labor costs;

[0024] The temperature of the platinum resistor is detected in real time through the temperature sensing chip. Because the positive and negative temperature coefficient thermistor and the bimetallic combination integrated protector are at the same ambient temperature, the deviation between the results is very small. By using both at the same time, the fault tolerance of the device is increased.

[0025] The upper and lower terminals are fixed by fixing seats instead of bolts, and the opening of the rectangular cavity is formed by sealing glue, which has better and more stable sealing performance, eliminates bolt fixing, and effectively avoids the problem of mechanical fatigue and gradual failure of bolts;

[0026] By using the temperature calibration sheet, the value of the current allowed to pass through the bimetallic element can be calibrated before packaging, which is specifically achieved by controlling the bending degree of the temperature calibration sheet. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative labor. Among them:

[0028] Figure 1 It is a cross-sectional structural schematic diagram of the front side of the present invention;

[0029] Figure 2 It is a schematic diagram of the cross-sectional structure of the present invention when viewed from above;

[0030] Figure 3 It is a structural schematic diagram of the upper terminal assembly of the present invention;

[0031] Figure 4 It is a schematic diagram of the structure of the temperature calibration sheet of the present invention;

[0032] Figure 5 It is a structural schematic diagram of the bimetallic element of the present invention;

[0033] Figure 6 The structure of the lower terminal assembly of the present invention is shown in FIG. Figure 1 ;

[0034] Figure 7 The structure of the lower terminal assembly of the present invention is shown in FIG. Figure 2 ;

[0035] Figure 8 It is a structural schematic diagram of the lower terminal of the present invention.

[0036] Figure numerals: 1. shell; 2. lower terminal; 3. static contact; 4. moving contact; 5. bimetallic element; 6. fixing seat; 7. temperature calibration plate; 8. temperature calibration plate deformation groove; 9. upper terminal connection convex ball point; 10. upper terminal; 11. sealant; 12. wire; 13. wire welding positioning claw; 14. connection convex point; 15. fixing seat connecting ring; 16. temperature calibration plate bracket; 17. cover; 18. epoxy glue; 19. wire a; 20. temperature sensing chip; 21. wire b. DETAILED DESCRIPTION

[0037] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the accompanying drawings.

[0038] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0039] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive with other embodiments.

[0040] Secondly, the present invention is described in detail with reference to the schematic diagram. When describing the embodiments of the present invention in detail, for the sake of convenience, the cross-sectional diagrams showing the device structure will not be partially enlarged according to the general scale, and the schematic diagrams are only examples, which should not limit the scope of protection of the present invention. In addition, in actual production, the three-dimensional dimensions of length, width and depth should be included.

[0041] like Figure 1-8 As shown, the present invention proposes a positive and negative temperature coefficient thermistor and a bimetallic combined integrated protector, comprising a housing 1, the interior of the housing 1 is a rectangular cavity with one side open, an upper terminal assembly and a lower terminal assembly are accommodated inside the rectangular cavity of the housing 1, and the upper terminal assembly is located above the lower terminal assembly;

[0042] The upper terminal assembly is connected to the inner top wall of the rectangular cavity, the lower terminal assembly is connected to the inner bottom wall of the rectangular cavity, and a fixing seat 6 is provided between the upper terminal assembly and the lower terminal assembly, and the fixing seat 6 is formed by injection molding;

[0043] The upper terminal assembly includes a moving contact 4, a bimetallic element 5 and a temperature calibration sheet 7. The inner top wall of the rectangular cavity is face-to-face and abutted against the upper side of the temperature calibration sheet 7. The bimetallic element 5 is arranged on the lower side of the temperature calibration sheet 7. The bimetallic element 5 is made of two metal sheets with different thermal expansion coefficients. The moving contact 4 is arranged on the lower side of the end of the bimetallic element 5 away from the temperature calibration sheet 7.

[0044] A cover 17 is provided on the side of the housing 1, and the cover 17 and one side of the housing 1 form a cavity with one end open. A temperature sensing chip 20 is provided on the inner side of the cover 17, and a wire a19 and a wire b21 are connected to the temperature sensing chip 20. The wire a19, the temperature sensing chip 20 and the wire b21 are wrapped in the inner side of the epoxy glue 18, and the epoxy glue 18 is located on the inner side of the cover 17;

[0045] A temperature calibration sheet deformation groove 8 is provided at the bottom of one end of the temperature calibration sheet 7. The temperature calibration sheet deformation groove 8 is a V-shaped groove. The depth of the temperature calibration sheet deformation groove 8 is one fifth of the thickness of the temperature calibration sheet 7. The other end of the temperature calibration sheet 7 is recessed downward to form an upper terminal connection convex ball point 9. The shape of the upper terminal connection convex ball point 9 is hemispherical. The upper terminal connection convex ball point 9 is inserted into the bimetallic element 5.

[0046] The lower terminal assembly includes a stationary contact 3 , and the movable contact 4 is movably abutted against the stationary contact 3 .

[0047] The upper terminal assembly includes an upper terminal 10. The upper terminal 10 is provided at one end of the temperature calibration sheet 7 away from the bimetallic element 5. The upper side of the upper terminal 10 is inserted into the upper terminal connection convex point 9. The bottom of the upper terminal 10 is provided with a wire welding positioning claw 13.

[0048] The wire welding positioning claw 13 is connected to a wire 12 .

[0049] The wire welding positioning claw 13 is used to externally connect the wire 12 so that the wire 12 is connected to the upper terminal assembly.

[0050] The lower terminal assembly comprises a lower terminal 2, one end of which is provided with a wire welding positioning claw 13;

[0051] A fixing seat connection ring 15 is installed in the middle of the upper side of the lower terminal 2, and a square groove is opened in the middle of the lower terminal 2, and the square groove matches with the fixing seat connection ring 15;

[0052] The cast fixing seat 6 extends into the square groove, and the fixing seat connecting ring 15 is wrapped by the fixing seat 6 , so that the lower terminal 2 is fixedly connected to the inside of the housing 1 .

[0053] As a preferred technical solution for the integrated protector of the positive and negative temperature coefficient thermistor and the bimetallic combination, a wire 12 is welded, and a temperature calibration piece bracket 16 is provided at one end of the temperature calibration piece 7, and the lower side of the temperature calibration piece bracket 16 is fixedly connected to the upper side of the bimetallic element 5;

[0054] The temperature calibration piece bracket 16 strengthens the connection between the temperature calibration piece 7 and the bimetallic element 5 .

[0055] The rectangular cavity opening is filled with a sealant 11, the sealant 11 closes the only opening of the rectangular cavity, and the sealant 11 wraps the wire welding positioning claw 13;

[0056] The only opening of the rectangular cavity is sealed with a sealant 11 .

[0057] Four connection bumps 14 are provided on one side of the lower terminal 2 , and the connection bumps 14 are fixedly connected to the inner top wall of the rectangular cavity.

[0058] The temperature calibration sheet 7 is bent and deformed at the temperature calibration sheet deformation groove 8 .

[0059] The model of the temperature sensing chip 20 is DS18B20;

[0060] Wire a19 inputs current and wire b21 outputs current. During the process, the platinum resistor releases heat. Wire a is connected to one of the wires 12, and the other wire 12 and wire b21 are connected to the circuit as connecting wires and become part of the live wire.

[0061] The temperature sensing chip 20 detects the temperature change of the platinum resistor and transmits the signal to the processing device, and the processing device controls the closing or opening of the circuit.

[0062] The specific implementation method is as follows: when a large current passes through the bimetallic element 5 in a short period of time, the resistance of the bimetallic element 5 causes the bimetallic element 5 to generate a large amount of heat. The heat causes the shape of the bimetallic element 5 to change, overcoming the obstruction of the temperature calibration sheet 7. During the process, one end of the bimetallic element 5 is lifted upward and controls the moving contact 4 to move away from the static contact 3, so that the circuit where the static contact 3 and the moving contact 4 are located is cut off, thereby stopping the circuit from operating, thereby protecting the entire circuit and the electrical appliances thereon.

[0063] It will be appreciated that in the development of any actual implementation, as in any engineering or design project, numerous implementation-specific decisions may be made. Such a development effort may be complex and time-consuming, but will be a routine task of design, fabrication, and production for those of ordinary skill having the benefit of this disclosure without undue experimentation.

[0064] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. Positive and negative temperature coefficient thermistor and bimetallic combination integrated protector, characterized by: It comprises a housing (1), the interior of the housing (1) being a rectangular cavity with one side open, the interior of the rectangular cavity of the housing (1) containing an upper terminal assembly and a lower terminal assembly, the upper terminal assembly being located above the lower terminal assembly; The upper terminal assembly is connected to the inner top wall of the rectangular cavity, the lower terminal assembly is connected to the inner bottom wall of the rectangular cavity, and a fixing seat (6) is provided between the upper terminal assembly and the lower terminal assembly; A cover shell (17) is arranged on the side of the outer shell (1), and the cover shell (17) and one side of the outer shell (1) enclose a cavity with one end open. A temperature sensing chip (20) is arranged on the inner side of the cover shell (17), and the temperature sensing chip (20) is attached to a platinum resistor. One end of the platinum resistor is connected to a wire a (19) and a wire b (21), and the wire a (19), the temperature sensing chip (20) and the wire b (21) are wrapped inside an epoxy adhesive (18).

2. The positive and negative temperature coefficient thermistor and bimetallic integrated protector according to claim 1, characterized in that: The upper terminal assembly comprises a temperature calibration sheet (7), a bimetallic element (5) is arranged on the lower side of the temperature calibration sheet (7), and a moving contact (4) is arranged on the lower side of the bimetallic element (5) away from one end of the temperature calibration sheet (7); A temperature calibration sheet deformation groove (8) is provided at the bottom of one end of the temperature calibration sheet (7); the temperature calibration sheet deformation groove (8) is a V-shaped groove; the depth of the temperature calibration sheet deformation groove (8) is one fifth of the thickness of the temperature calibration sheet (7); the other end of the temperature calibration sheet (7) is recessed downward to form an upper terminal connection convex ball point (9); the upper terminal connection convex ball point (9) is in the shape of a hemisphere; and the upper terminal connection convex ball point (9) is inserted into the bimetallic element (5); The lower terminal assembly comprises a static contact (3), and the movable contact (4) is movably abutted against the static contact (3); The upper terminal assembly comprises an upper terminal (10), an upper terminal (10) is arranged at one end of the temperature calibration sheet (7) away from the bimetallic element (5), an upper terminal connection convex ball point (9) is inserted into the upper side of the upper terminal (10), and a wire welding positioning claw (13) is arranged at the bottom of the upper terminal (10).

3. The positive and negative temperature coefficient thermistor and bimetallic integrated protector according to claim 2, characterized in that: The lower terminal assembly comprises a lower terminal (2), one end of which is provided with a wire welding positioning claw (13).

4. The positive and negative temperature coefficient thermistor and bimetallic integrated protector according to claim 3, characterized in that: A fixing seat connecting ring (15) is arranged in the middle of the upper side of the lower terminal (2), and a square groove is opened in the middle of the lower terminal (2), and the square groove matches with the fixing seat connecting ring (15).

5. The positive and negative temperature coefficient thermistor and bimetallic integrated protector according to claim 2 or 3, characterized in that: A wire (12) is welded to the wire welding positioning claw (13), a temperature calibration plate bracket (16) is provided at one end of the temperature calibration plate (7), and the lower side of the temperature calibration plate bracket (16) is fixedly connected to the upper side of the bimetallic element (5).

6. The positive and negative temperature coefficient thermistor and bimetallic integrated protector according to claim 5, characterized in that: The opening of the rectangular cavity is filled with sealant (11), the sealant (11) closes the only opening of the rectangular cavity, and the sealant (11) wraps the wire welding positioning claw (13).

7. The positive and negative temperature coefficient thermistor and bimetallic integrated protector according to claim 2, characterized in that: Four connection bumps (14) are provided on one side of the lower terminal (2), and the connection bumps (14) are fixedly connected to the inner top wall of the rectangular cavity.

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