High-sensitivity miniature overheat protector

Abstract

The utility model belongs to the technical field of overheat protectors, and particularly relates to a high-sensitivity miniature overheat protector. Comprising a protective shell, a bottom plate is arranged at the bottom end of the inner side of the protective shell, a connecting plate is arranged above the bottom plate, a fixing plate is fixedly arranged at one end of the connecting plate, a first movable contact piece is fixedly arranged at one end of the fixing plate, and fixing springs are arranged on the two sides of the first movable contact piece. One end of the fixed spring is fixedly connected with the fixed plate, and the front and rear side wall surfaces of the first movable contact piece are fixedly provided with connecting columns. According to the utility model, through the arrangement of the metal sheet, the metal sheet can be turned over upwards through heating so as to abut against the first movable contact piece, the first movable contact piece is turned over upwards under stress, and the fixing spring pulls the first movable contact piece which is turned over upwards in the process that the first movable contact piece is turned over upwards under stress, so that the turning speed of the first movable contact piece can be accelerated; therefore, the sensitivity of power failure of the overheat protector due to heating is improved.

Description

Technical Field

[0001] This utility model relates to the field of overheat protector technology, specifically a highly sensitive miniature overheat protector. Background Art

[0002] During operation, electrical circuits may overheat due to short circuits, excessive loads, or other reasons. Failure to disconnect the power in time can lead to circuit burnout or even fire. To ensure circuit safety, an overheat protector is installed. The overheat protector's power-off protection function is primarily achieved through the interaction of its internal temperature-sensitive deformation element and moving contact. Specifically, two metal sheets of different materials are bonded together to form the temperature-sensitive deformation element. Different metals have different coefficients of thermal expansion, so when heated, the upper and lower metal sheets expand differently, causing the entire element to deform. This deformation pushes the moving contact, breaking the circuit. After the heat dissipates, the element returns to its original shape, and the moving contact resets, reconnecting the circuit. It can be seen that the overheat protector's function heavily relies on the effect of the deformed temperature-sensitive element on the moving contact. If the deformation is slow or insufficient, the power-off protection function will be compromised.

[0003] For example, a highly sensitive miniature overheat protector with application number 202211645209.4 provides a support point for the deformed temperature-sensitive deformation element by setting a convex surface on the base, restricting the downward movement of the temperature-sensitive deformation element, and enabling the edge of the temperature-sensitive deformation element to provide a greater pushing force to the moving contact, thereby improving the sensitivity of the overheat protector; at the same time, after the temperature-sensitive deformation element pushes the moving contact to move, the support point prevents the moving contact from retracting by abutting against the temperature-sensitive deformation element, and the temperature-sensitive deformation element then abutting against the moving contact, thereby ensuring the reliability of the overheat power-off protection function.

[0004] It has the following disadvantages:

[0005] When the overheat protector disconnects power, it does so by bending and deforming the temperature-sensitive deformation element due to heat, thereby lifting the moving contact and separating the moving contact from the stationary contact on the first base plate. Since the deformation of the temperature-sensitive deformation element occurs gradually when heated, the overheat protector needs to complete the bending deformation of the temperature-sensitive deformation element before disconnecting power when the temperature exceeds the predetermined protection temperature. This results in low power-off sensitivity of the overheat protector when the temperature exceeds the predetermined protection temperature.

[0006] Therefore, we propose a highly sensitive miniature overheat protector to solve the above problems. Utility Model Content

[0007] (a) Technical problems to be solved

[0008] In view of the shortcomings of the prior art, this utility model provides a highly sensitive miniature overheat protector, which solves the problems mentioned in the background art.

[0009] (2) Technical solution

[0010] In order to achieve the above-mentioned purpose, the present invention specifically adopts the following technical solutions:

[0011] A highly sensitive miniature overheat protector includes a protective shell, a base plate at the bottom inner side of the protective shell, a connecting plate above the base plate, a fixing plate fixedly mounted at one end of the connecting plate, a first movable contact fixedly mounted at one end of the fixing plate, fixing springs on both sides of the first movable contact, one end of the fixing springs being fixedly connected to the fixing plate, connecting posts fixedly mounted on the front and rear side walls of the first movable contact, the ends of the two fixing springs away from the fixing plate passing through the connecting posts, and a limiting ring sleeved on the ends of the fixing springs passing through the connecting posts, and a metal sheet fixedly mounted on the upper surface of the base plate, the metal sheet being located below one end of the first movable contact.

[0012] Furthermore, a stationary contact block is fixedly provided on the upper end surface of the base plate, the stationary contact block is located on one side of the metal sheet, a pad is provided on the upper end surface of the connecting plate, and a second moving contact piece is provided on the upper end surface of the pad.

[0013] Furthermore, a movable contact block is fixedly provided on the lower end face of the second movable contact piece, and the positions of the movable contact block and the stationary contact block correspond to each other. A pressure plate is provided on the upper end face of the second movable contact piece.

[0014] Furthermore, the moving contact block and the stationary contact block are in contact with each other, a base is provided on the upper end surface of the base plate, and a connecting block is fixedly provided on the lower end surface of the base.

[0015] Furthermore, limiting protrusions are fixedly provided on the front and rear side walls of the base plate, and two limiting grooves are opened on the lower end face of the base, and the two limiting grooves on the lower end face of the base are engaged with the two limiting protrusions on the base plate.

[0016] Furthermore, the base, pad, second movable contact piece, and pressure plate are all provided with connection holes, and the multiple connection holes are arranged in a straight line.

[0017] Furthermore, the cross-sections of the first movable contact piece and the metal piece are both arc-shaped, and the size of the limiting groove is adapted to the size of the limiting protrusion.

[0018] (3) Beneficial effects

[0019] Compared with the prior art, this utility model provides a highly sensitive miniature overheat protector with the following advantages:

[0020] In this invention, the metal sheet can be heated and flipped upwards to contact the first movable contact. The first movable contact is then forced to flip upwards, and during this upward flipping process, a fixed spring pulls on the first movable contact, which accelerates the flipping speed of the first movable contact and thus improves the sensitivity of the overheat protector to cut off power when heated. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the overall structure of this utility model;

[0022] Figure 2 This is the first exploded view of the base plate and the second movable contact piece of this utility model;

[0023] Figure 3 This is the second exploded view of the base plate and the second movable contact piece of this utility model;

[0024] Figure 4 This is a perspective view of the connection between the first movable contact piece and the fixed plate of this utility model;

[0025] Figure 5 This is a disassembled view of the base plate and the base of this utility model.

[0026] In the diagram: 1. Protective shell; 2. Base plate; 3. Connecting plate; 4. Fixing plate; 5. First moving contact piece; 6. Fixing spring; 7. Connecting column; 8. Limiting ring; 9. Metal sheet; 10. Stationary contact block; 11. Pad plate; 12. Second moving contact piece; 13. Moving contact block; 14. Pressure plate; 15. Base; 16. Connecting block; 17. Limiting protrusion; 18. Limiting groove. Detailed Implementation

[0027] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0028] Example

[0029] like Figure 1-5As shown in the figure, a highly sensitive miniature overheat protector according to one embodiment of the present invention includes a protective shell 1, a base plate 2 provided at the bottom inner side of the protective shell 1, a connecting plate 3 provided above the base plate 2, a fixing plate 4 fixedly provided at one end of the connecting plate 3, a first movable contact piece 5 fixedly provided at one end of the fixing plate 4, fixing springs 6 provided on both sides of the first movable contact piece 5, one end of the fixing springs 6 being fixedly connected to the fixing plate 4, connecting posts 7 fixedly provided on the front and rear side walls of the first movable contact piece 5, the ends of the two fixing springs 6 away from the fixing plate 4 passing through the connecting posts 7, and a limiting ring 8 sleeved on the end of the fixing springs 6 passing through the connecting posts 7, and a metal sheet 9 fixedly provided on the upper surface of the base plate 2, the metal sheet 9 being located below one end of the first movable contact piece 5.

[0030] The metal plate 9 can be heated and flipped upwards to contact the first movable contact 5. The first movable contact 5 is then forced to flip upwards. During the upward flipping process, the fixing spring 6 pulls the first movable contact 5, which can speed up the flipping speed of the first movable contact 5 and thus improve the sensitivity of the overheat protector to cut off power when heated.

[0031] A stationary contact block 10 is fixedly disposed on the upper end surface of the base plate 2. The stationary contact block 10 is located on one side of the metal sheet 9. A pad 11 is disposed on the upper end surface of the connecting plate 3. A second movable contact piece 12 is disposed on the upper end surface of the pad 11. A movable contact block 13 is fixedly disposed on the lower end surface of the second movable contact piece 12. The movable contact block 13 and the stationary contact block 10 are positioned corresponding to each other. A pressure plate 14 is disposed on the upper end surface of the second movable contact piece 12.

[0032] The arrangement of the moving contact 13 and the stationary contact 10 enables the electrical equipment protected by the overheat protector to be powered on normally.

[0033] The moving contact 13 is in contact with the stationary contact 10. A base 15 is provided on the upper surface of the base plate 2, and a connecting block 16 is fixedly provided on the lower surface of the base 15. Limiting protrusions 17 are fixedly provided on the front and rear side walls of the base plate 2. Two limiting grooves 18 are provided on the lower surface of the base 15, and the two limiting grooves 18 on the lower surface of the base 15 are engaged with the two limiting protrusions 17 on the base plate 2. Connecting holes are provided on the base 15, the pad 11, the second moving contact piece 12, and the pressure plate 14, and the multiple connecting holes are arranged in a straight line. The cross-sections of the first moving contact piece 5 and the metal piece 9 are both arc-shaped, and the size of the limiting groove 18 is adapted to the size of the limiting protrusion 17.

[0034] The pressure plate 14 is used to fasten the connecting plate 3, the pad 11, and the second movable contact piece 12 to the upper end face of the base 15. The connection hole facilitates fixing the pad 11, the second movable contact piece 12, and the pressure plate 14 to the base 15 with bolts. The first movable contact piece 5, whose cross-section is arc-shaped, has a downward pulling force through the fixing spring 6. This can prevent the first movable contact piece 5 from flipping directly due to the contact of the metal piece 9 when it is in a horizontal state, which could easily cause the overheat protector to be falsely triggered.

[0035] The working principle of this practical application is as follows:

[0036] When the temperature at the location of the overheat protector is below the predetermined temperature protection value, the bent portion of the second moving contact 12 bends downwards. At this time, the moving contact 13 on the second moving contact 12 contacts the stationary contact 10, and the electrical equipment protected by the overheat protector can be powered normally. When the temperature at the location of the overheat protector rises to the predetermined temperature protection value, the metal sheet 9 is heated and flips upwards. During the flipping process, the metal sheet 9 presses against one end of the first moving contact 5, and the first moving contact 5 deforms under force. When the first moving contact 5 flips... When the first movable contact 5 is aligned with the fixed spring 6, it continues to rotate under the force. Under the pull of the fixed spring 6, the first movable contact 5 quickly rotates upward and rests on the second movable contact 12. The first movable contact 5 resting on the second movable contact 12 lifts the second movable contact 12. The lifting of the second movable contact 12 will cause the movable contact block 13 on the second movable contact 12 to separate from the stationary contact block 10 on the base plate 2. At this time, the circuit is disconnected to protect the electrical equipment protected by the overheat protector from damage due to overheating.

[0037] Finally, it should be noted that the above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A highly sensitive miniature overheat protector, comprising a protective shell (1), characterized in that: The protective shell (1) has a bottom plate (2) at its inner bottom end. A connecting plate (3) is provided above the bottom plate (2). A fixing plate (4) is fixedly provided at one end of the connecting plate (3). A first movable contact piece (5) is fixedly provided at one end of the fixing plate (4). Fixing springs (6) are provided on both sides of the first movable contact piece (5). One end of the fixing spring (6) is fixedly connected to the fixing plate (4). Connecting posts (7) are fixedly provided on the front and rear side walls of the first movable contact piece (5). The ends of the two fixing springs (6) away from the fixing plate (4) pass through the connecting posts (7). A limiting ring (8) is sleeved on the end of the fixing spring (6) that passes through the connecting posts (7). A metal piece (9) is fixedly provided on the upper surface of the bottom plate (2). The metal piece (9) is located below one end of the first movable contact piece (5).

2. The high-sensitivity miniature overheat protector according to claim 1, characterized in that: A stationary contact block (10) is fixedly provided on the upper end surface of the base plate (2). The stationary contact block (10) is located on one side of the metal sheet (9). A pad (11) is provided on the upper end surface of the connecting plate (3). A second moving contact piece (12) is provided on the upper end surface of the pad (11).

3. A highly sensitive miniature overheat protector according to claim 2, characterized in that: A movable contact block (13) is fixedly provided on the lower end face of the second movable contact piece (12). The movable contact block (13) and the stationary contact block (10) are positioned in opposite directions. A pressure plate (14) is provided on the upper end face of the second movable contact piece (12).

4. A highly sensitive miniature overheat protector according to claim 3, characterized in that: The moving contact block (13) is in contact with the stationary contact block (10). The upper end surface of the base plate (2) is provided with a base (15), and the lower end surface of the base (15) is fixedly provided with a connecting block (16).

5. A highly sensitive miniature overheat protector according to claim 4, characterized in that: Limiting protrusions (17) are fixedly provided on the front and rear side walls of the base plate (2), and two limiting grooves (18) are opened on the lower end face of the base (15). The two limiting grooves (18) on the lower end face of the base (15) are engaged with the two limiting protrusions (17) on the base plate (2).

6. A highly sensitive miniature overheat protector according to claim 4, characterized in that: The base (15), pad (11), second movable contact piece (12), and pressure plate (14) are all provided with connection holes, and the multiple connection holes are arranged in a straight line.

7. A highly sensitive miniature overheat protector according to claim 5, characterized in that: The cross-sections of the first movable contact piece (5) and the metal piece (9) are both arc-shaped, and the size of the limiting groove (18) is adapted to the size of the limiting protrusion (17).

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