Thermo-sensitive block for thermal fuse and thermal fuse

Abstract

The utility model provides a thermosensitive block for a thermal fuse and the thermal fuse. In one aspect, a heat sensitive block for a thermal fuse is described, the heat sensitive block configured for thermal deformation at a predetermined temperature to shut off a circuit of the thermal fuse. The thermosensitive block comprises a first thermosensitive material layer, a second thermosensitive material layer and a metal material layer arranged between the first thermosensitive material layer and the second thermosensitive material layer. The thermosensitive block for the thermal fuse has high heat conduction speed and response sensitivity, so that the thermal fuse provided with the thermosensitive block has high thermal response speed, the safety performance of an electric appliance is improved, and the service life of the electric appliance is prolonged.

Description

Technical Field

[0001] This utility model relates to the field of thermal fuses, and particularly to a thermistor block for a thermal fuse and a thermal fuse including such a thermistor block. Background Technology

[0002] A thermal fuse (TCO) is a non-resettable, one-time over-temperature protection device. It is primarily used to protect electrical equipment from damage caused by abnormally high temperatures. When the temperature exceeds its rated operating temperature, the internal connection of the thermal fuse melts, thus cutting off the circuit and preventing safety accidents such as fires and equipment damage caused by overheating. Thermal fuses are also used in personal appliances such as hair dryers, hair straighteners, clothes dryers, ovens, and irons. When the appliance experiences an abnormal temperature rise due to a malfunction (such as a stalled motor or a short circuit in the heating element), the thermal fuse senses the temperature change. When its rated operating temperature is reached, the thermistor inside the thermal fuse deforms due to heat, breaking the circuit and cutting off the power to the appliance. As a critical over-temperature protection element, the performance of the thermistor is crucial for the thermal fuse's rapid response and effective protection. Traditional thermistors have certain limitations in terms of heat conduction speed and response sensitivity, which makes thermal fuses with such thermistors have a slow thermal response speed. When such thermal fuses reach their rated operating temperature, the thermal response time is too long, for example, it will cut off the circuit after about 25 seconds. However, 25 seconds is too long for human and electrical appliances, which cannot guarantee the safety of electrical appliances or people, and thus may cause potential safety problems or damage to electrical appliances. Utility Model Content

[0003] To address the aforementioned problems, one objective of one or more embodiments of this utility model is to provide a thermistor block for a thermal fuse that can improve the thermal response speed of the thermal fuse.

[0004] Another object of one or more embodiments of this utility model is to provide a thermal fuse including the above-described thermistor block.

[0005] According to one aspect of the present invention, a thermistor block for a thermal fuse is provided, the thermistor block being configured to undergo thermal deformation at a predetermined temperature to cut off the circuit of the thermal fuse, wherein the thermistor block includes a first thermistor material layer, a second thermistor material layer, and a metal material layer disposed between the first thermistor material layer and the second thermistor material layer.

[0006] Preferably, the metal material layer is a copper sheet.

[0007] Preferably, the thermal block is cylindrical or truncated conical in shape.

[0008] Preferably, the first thermosensitive material layer and the metal material layer form a first cylindrical portion, the second thermosensitive material layer forms a second cylindrical portion, and the diameter of the first cylindrical portion is smaller than the diameter of the second cylindrical portion.

[0009] Preferably, the center of the thermosensitive block has a through hole that penetrates the first thermosensitive material layer, the metal material layer, and the second thermosensitive material layer.

[0010] Preferably, the lower part of the thermal block has a groove to form at least two legs.

[0011] According to another aspect of the present invention, a thermistor block for a thermal fuse is provided, the thermistor block being made of a thermistor material and configured to undergo thermal deformation at a predetermined temperature to cut off the circuit of the thermal fuse, wherein the thermistor block is cylindrical and the lower part of the thermistor block has a groove to form at least two legs.

[0012] Preferably, the thermal block has a through hole at its center.

[0013] According to another aspect of the present invention, a thermistor block for a thermal fuse is provided, the thermistor block being made of a thermistor material and configured to undergo thermal deformation at a predetermined temperature to cut off the circuit of the thermal fuse, wherein the thermistor block is truncated conical in shape.

[0014] Preferably, the thermal block has a through hole at its center.

[0015] According to another aspect of the present invention, a thermistor block for a thermal fuse is provided, the thermistor block being made of a thermistor material and configured to undergo thermal deformation at a predetermined temperature to cut off the circuit of the thermal fuse, wherein the thermistor block includes a first cylindrical portion and a second cylindrical portion, and the diameter of the first cylindrical portion is smaller than the diameter of the second cylindrical portion.

[0016] Preferably, the bottom of the first cylindrical portion is located at the center of the upper surface of the second cylindrical portion.

[0017] According to another aspect of the present invention, a thermal fuse is provided, wherein the thermal fuse includes a thermistor block for a thermal fuse as described in any of the above aspects.

[0018] According to the technical solution of this utility model, the thermistor block is configured to include a first thermistor material layer, a second thermistor material layer, and a metal material layer located between the two; or the thermistor block is configured as a cylinder with at least two legs; or the thermistor block is configured as a truncated cone; or the thermistor block is configured as having two cylindrical parts with different diameters. These specially structured thermistors have high thermal conductivity and response sensitivity, allowing them to soften or melt more quickly and deform thermally when the ambient temperature of the thermal fuse rises to a predetermined temperature (the rated operating temperature of the thermal fuse), thereby rapidly cutting off the circuit of the thermal fuse. Therefore, thermal fuses equipped with the thermistors of this utility model have a faster thermal response speed, thus improving the safety performance of electrical appliances and preventing damage to electrical appliances due to overheating, thereby extending the service life of the electrical appliances. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of a thermal fuse equipped with a thermal block according to this utility model before operation;

[0020] Figure 2 This is a schematic diagram of a thermal fuse equipped with a thermal block according to this utility model after operation;

[0021] Figure 3a This is a perspective view of the thermal block according to the first embodiment of the present invention;

[0022] Figure 3b This is a cross-sectional view of the thermal block according to the first embodiment of the present invention;

[0023] Figure 4a This is a top perspective view of the thermal block according to the second embodiment of the present invention;

[0024] Figure 4b This is a bottom perspective view of the thermal block according to the second embodiment of the present invention;

[0025] Figure 5 This is a perspective view of a thermal block according to the third embodiment of the present invention; and

[0026] Figure 6 This is a perspective view of the thermal block according to the fourth embodiment of the present invention. Detailed Implementation

[0027] The following description, in conjunction with the accompanying drawings, will depict a thermistor block according to the present invention and a thermal fuse incorporating the thermistor block according to the present invention.

[0028] Although the terms first, second, third, etc., may be used herein to describe various elements, components, regions, layers, and / or segments, these elements, components, regions, layers, and / or segments should not be limited by these terms. These terms may be used only to distinguish one element, component, region, layer, or segment from another region, layer, or segment. Unless the context clearly indicates otherwise, terms such as “first,” “second,” and other numerical terms used herein do not imply order or sequence. Therefore, the first element, component, region, layer, or segment discussed below may be referred to as a second element, component, region, layer, or segment without departing from the teachings of the exemplary embodiments.

[0029] The following is based on Figure 1 and Figure 2 This describes the structure and basic working principle of the thermal fuse 1. Among them, Figure 1 This is a schematic diagram of the thermal fuse 1 equipped with the thermal block 10 according to this utility model before operation, and Figure 2 This is a schematic diagram of a thermal fuse 1 with the thermal block 10 according to this utility model installed after operation.

[0030] like Figure 1 and Figure 2 As shown, the thermal fuse 1 includes a metal housing 11, a first lead element 12, a second lead element 13, a first spring element 14, a second spring element 15, a movable conductor 16, and a thermistor block 10. The first lead element 12 and the second lead element 13 are respectively fixedly connected to two opposite ends of the metal housing 11. The first lead element 12 extends into the interior of the metal housing 11 from an opening at one end of the metal housing 11 and passes through an insulating sleeve 17 inside the metal housing 11 to insulate it from the metal housing 11. A first electrode 18 is formed at the end of the first lead element 12 that extends into the metal housing 11. A protective insulating sleeve 19 is provided at the external outlet of the first lead element 12, and the protective insulating sleeve 19 is fixedly connected to the metal housing 11 by a sealing resin 20. The second lead element 13 is fixedly connected (e.g., riveted) to the other end of the metal housing 11, using the inner wall surface of the metal housing 11 itself as the second electrode. The thermal block 10 is disposed inside the metal housing 11 near the second lead element 13, and the second spring element 15 is disposed between the thermal block 10 and the movable conductor 16 on both sides between the push plates 21 and 22.

[0031] The first spring element 14 and the second spring element 15, at room temperature, are as follows: Figure 1As shown, the second spring element 15 resists the elastic force of the first spring element 14, pushing the push plate 21 and then the movable conductor 16, thus making the movable conductor 16 in close contact with the first electrode 18. At this time, the circuit between the first electrode 18 and the second electrode of the thermal fuse 1 is in a conductive state. When the temperature rises abnormally and reaches the predetermined temperature (the rated operating temperature of the thermal fuse), such as Figure 2 As shown, the thermistor 10 undergoes thermal deformation by softening or melting at a predetermined temperature. At this time, the pushing force of the first spring element 14 causes the movable conductor 16 to move. Simultaneously, the second spring element 15 pushes the push plate 22 to the right, and the spring force of the second spring element 15 decreases, causing the first spring element 14 to push the movable conductor 16 against the second electrode formed by the inner wall of the metal casing 11. This movement of the movable conductor 16 separates it from the first electrode 18, thus breaking the circuit between the first electrode 18 and the second electrode of the thermal fuse 1.

[0032] As a critical overheat protection element, the performance of the thermistor in a thermal fuse is crucial for its rapid response and effective protection. Traditional thermistors have limitations in heat conduction speed and response sensitivity, resulting in a slower thermal response speed in thermal fuses, which can lead to potential safety issues or damage to electrical appliances. To improve the thermal response speed of thermal fuses, the inventors of this application have designed thermistors with the following structures. Those skilled in the art should understand that... Figure 1 and Figure 2 The thermal fuse 1 shown is only one example of a thermal fuse, and the thermal blocks of several structures described below in this application can be used for any type of thermal fuse known in the related art.

[0033] In the following text, we will combine Figure 3a and Figure 3b The thermal block 10 according to the first embodiment of the present invention will be described. Figure 3a This is a perspective view of the thermal block 10 according to the first embodiment of the present invention, and Figure 3b This is a cross-sectional view of the thermal block 10 according to the first embodiment of the present invention.

[0034] like Figure 3a and Figure 3b As shown, the thermal block 10 for a thermal fuse according to the first embodiment of the present invention may include: a first thermal material layer 101, a second thermal material layer 102, and a metal material layer 103 disposed between the first thermal material layer 101 and the second thermal material layer 102.

[0035] According to the first embodiment of this utility model, the thermistor block 10 for a thermal fuse has a unique three-layer structure. The thermistor block 10 includes a first thermistor material layer 101, a second thermistor material layer 102, and a metal material layer 103 disposed between the two thermistor material layers. The metal material layer 103 has excellent thermal conductivity, which accelerates the transfer of heat between the two thermistor material layers, making the overall temperature sensing of the thermistor block 10 more rapid and uniform. Therefore, the thermistor block 10 has a high heat conduction speed and response sensitivity. When the ambient temperature of the thermal fuse rises and reaches a predetermined temperature (the rated operating temperature of the thermal fuse), heat is rapidly conducted through the metal material layer 103 to the first thermistor material layer 101 and the second thermistor material layer 102, causing the first and second thermistor material layers 101 and 102 to soften or melt more quickly, resulting in thermal deformation and thus rapidly cutting off the circuit of the thermal fuse. Therefore, the thermal fuse equipped with the thermal block 10 of this utility model has a faster thermal response speed, thereby improving the safety performance of electrical appliances and preventing electrical appliances from being damaged due to overheating, thus extending the service life of electrical appliances.

[0036] Preferably, the metal material layer 103 is a copper sheet. Copper sheets have excellent thermal conductivity, which allows heat to be transferred to the two thermistor material layers more quickly, thereby improving the thermal response speed of the thermal fuse. Alternatively, it is conceivable that the metal material layer 103 can also be made of other metal sheets with good thermal conductivity, such as aluminum sheets, iron sheets, etc.

[0037] Preferably, at least one of the first thermistor layer 101 and the second thermistor layer 102 is coated with a thermally conductive silicone grease material known in the prior art. Adding thermally conductive silicone grease material to the first thermistor layer 101 and the second thermistor layer 102 can further improve the heat conduction efficiency within the two thermistor layers and with the surrounding environment, reduce thermal resistance, and ensure that heat can be sensed by the two thermistor layers in a timely manner, thereby further improving the thermal response speed of the thermal fuse.

[0038] Preferably, such as Figure 1 As shown, each of the first thermistor layer 101, the second thermistor layer 102, and the metal layer 103 has a circular cross-section with equal diameters, making the thermistor block 10 cylindrical overall. The circular cross-section of each layer and the overall cylindrical shape of the thermistor block 10 facilitate its installation and use in thermal fuses, while also ensuring good structural stability and uniform heat conduction. However, it is also conceivable that the cross-section of each layer of the thermistor block 10 could be designed as elliptical, rectangular, pentagonal, or hexagonal, making the thermistor block 10 cylindrical overall, to match the different internal installation spaces of various thermal fuses.

[0039] For a thermistor block 10 comprising a first thermistor layer 101, a second thermistor layer 102, and a metal layer 103, the raw materials for the first and second thermistor layers 101 and 102 are first prepared, using processes such as powder metallurgy and pressing / sintering to form the thermistor materials into a disc shape. Then, a metal layer (such as a copper sheet) 103 is placed between the two thermistor layers and bonded tightly together using methods such as adhesion. If thermally conductive silicone grease is added, it can be uniformly mixed into the thermistor powder during the preparation of the thermistor layers before molding. Finally, the assembled three-layer structure is processed into a cylindrical shape, and dimensional accuracy and surface flatness are ensured through processes such as cutting and polishing.

[0040] Next, we will combine Figure 4a and Figure 4b The thermal block 10a according to the second embodiment of the present invention will be described. Figure 4a This is a top perspective view of the thermal block 10a according to the second embodiment of the present invention, and Figure 4b This is a bottom perspective view of the thermal block 10a according to the second embodiment of the present invention.

[0041] like Figure 4a and Figure 4b As shown, the thermal block 10a according to the second embodiment of the present invention is cylindrical, and the lower part of the thermal block 10a has a groove to form at least two legs 130.

[0042] In the second embodiment of the present invention, the thermistor block 10a is cylindrical and has a groove at the bottom to form at least two legs. This leg structure reduces the contact area between the bottom of the thermistor block 10a and the housing of the thermal fuse, increasing heat convection efficiency to some extent. Furthermore, while maintaining a certain strength, it reduces the overall weight, allowing for a more sensitive response to temperature changes. Therefore, the thermistor block 10a has a high thermal conductivity and response sensitivity. Thus, when the ambient temperature of the thermal fuse rises and reaches a predetermined temperature (the rated operating temperature of the thermal fuse), the thermistor block 10a can soften or melt more quickly, causing thermal deformation and rapidly cutting off the circuit of the thermal fuse. Therefore, the thermal fuse equipped with the thermistor block 10a of the present invention has a faster thermal response speed, thereby improving the safety performance of electrical appliances and preventing damage due to overheating, thus extending the service life of the electrical appliances.

[0043] Preferably, in this embodiment, such as Figure 4a and Figure 4bAs shown, the thermistor 10a has a through hole 110 at its center. The through hole design reduces the weight of the thermistor 10a and changes its mass distribution and heat conduction path, allowing heat to be transferred more quickly within the thermistor 10a when heated, reducing thermal hysteresis, thereby further improving the heat conduction speed and response sensitivity of the thermistor 10a, and consequently improving the thermal response speed of the thermal fuse.

[0044] In this embodiment, if the thermal block 10a has a through hole 110 at its center, such as Figure 4a and Figure 4b As shown, two legs 130 can be formed by cutting two grooves 120 through the wall thickness of the thermal block 10a in the lower part of the thermal block 10a. However, it is conceivable that any number of legs can be formed by cutting different numbers of grooves through the wall thickness of the thermal block 10a in the lower part of the thermal block 10a, such as forming three legs by cutting three grooves, or forming four legs by cutting four grooves, etc.

[0045] Alternatively, it can be envisioned that, in the case where the thermal block 10a is a solid cylinder, i.e. without through holes, two legs can be formed by cutting a groove in the lower part of the thermal block 10a that runs radially through the lower part.

[0046] In the following text, we will combine Figure 5 and Figure 6 Thermistor block 10b according to the third embodiment of the present invention and thermistor block 10c according to the fourth embodiment of the present invention will be described. Among them, Figure 5 This is a perspective view of the thermal block 10b according to the third embodiment of the present invention, and Figure 6 This is a perspective view of the thermal block 10c according to the fourth embodiment of the present invention.

[0047] like Figure 5 As shown, the thermal block 10b according to the third embodiment of the present invention is in the shape of a truncated cone.

[0048] In the third embodiment of the present invention, the thermistor block 10b is truncated conical in shape, which reduces its weight while maintaining its compressive strength. The truncated conical shape of the thermistor block 10b, due to its special geometry, causes different degrees of thermal expansion in different parts during heat conduction from bottom to top, making it more prone to stress changes. Therefore, the thermistor block 10b has a high thermal conductivity and response sensitivity. Thus, when the ambient temperature of the thermal fuse rises to a predetermined temperature (the rated operating temperature of the thermal fuse), the thermistor block 10b can soften or melt more quickly, causing thermal deformation and rapidly cutting off the circuit of the thermal fuse. Therefore, the thermal fuse equipped with the thermistor block 10b of the present invention has a faster thermal response speed, thereby improving the safety performance of electrical appliances and preventing damage due to overheating, thus extending the service life of the electrical appliances.

[0049] Preferably, in this embodiment, such as Figure 5 As shown, the thermistor 10b has a through hole 140 at its center. The through hole design reduces the weight of the thermistor 10b and changes its mass distribution and heat conduction path, allowing heat to be transferred more quickly within the thermistor 10b when heated, reducing thermal hysteresis, thereby further improving the heat conduction speed and response sensitivity of the thermistor 10b, and consequently improving the thermal response speed of the thermal fuse.

[0050] like Figure 6 As shown, the thermal block 10c according to the fourth embodiment of the present invention includes a first cylindrical portion 150 and a second cylindrical portion 160, wherein the diameter of the first cylindrical portion 150 is smaller than the diameter of the second cylindrical portion 160. Preferably, in this embodiment, as... Figure 6 As shown, the bottom of the first cylindrical portion 150 is located at the center of the upper surface of the second cylindrical portion 160. That is to say, the thermal block 10c is generally inverted T-shaped.

[0051] In the thermistor block 10c according to the fourth embodiment of the present invention, by forming two cylindrical portions with different diameters, the weight of the thermistor block 10c is reduced while maintaining its compressive strength. Furthermore, when the thermistor block 10c is heated, the difference in diameter between the first cylindrical portion 150 and the second cylindrical portion 160 results in different thermal expansion effects, thereby inducing changes in internal stress and accelerating the action response of the thermistor block 10c. Therefore, the thermistor block 10c has a high thermal conductivity and response sensitivity. Thus, when the ambient temperature of the thermal fuse rises and reaches the predetermined temperature (the rated operating temperature of the thermal fuse), the thermistor block 10c can soften or melt more quickly, causing thermal deformation and rapidly cutting off the circuit of the thermal fuse. Therefore, the thermal fuse equipped with the thermistor block 10c of the present invention has a faster thermal response speed, thereby improving the safety performance of electrical appliances and preventing damage to electrical appliances due to overheating, thus extending the service life of the electrical appliances.

[0052] In addition, thermally conductive silicone grease, a material known in the prior art, can be added to the thermistor block according to the second to fourth embodiments of this utility model to further optimize its thermal conductivity, enhance the thermistor block's sensitivity to temperature changes, and ensure that the thermal fuse protection mechanism can be quickly activated when the electrical equipment experiences abnormal heating, thereby further improving the thermal response speed of the thermal fuse.

[0053] Furthermore, the first thermosensitive material layer 101 and the second thermosensitive material layer 102, the thermosensitive block 10a, the thermosensitive block 10b, and the thermosensitive block 10c are made of thermosensitive materials known in the prior art, such as thermoplastic resins. The thermoplastic resin is preferably a polyolefin. Thermosensitive blocks using thermoplastic resins exhibit less deterioration in terms of particle softening, deformation, sublimation, and deliquescence, are less affected by environmental conditions, and have many advantages in manufacturing processes and post-manufacturing storage conditions, thus facilitating practical application.

[0054] Furthermore, those skilled in the art will understand that the various technical features of the embodiments described above can be combined in different ways to obtain various different embodiments. Accordingly, the various different embodiments obtained by combining the various technical features described above can achieve the sum of the technical effects brought about by the various technical features described above.

[0055] For example, the three-layer thermal block 10 according to the first embodiment of the present invention can be generally cylindrical or truncated conical. Alternatively, the thermal block 10 can be generally inverted T-shaped, i.e., having a first cylindrical portion and a second cylindrical portion with different diameters, the diameter of the first cylindrical portion being smaller than the diameter of the second cylindrical portion. The first thermal material layer 101 and the metal material layer 103 can form the first cylindrical portion, while the second thermal material layer 102 can form the second cylindrical portion. However, it is also conceivable that the first thermal material layer 101 can form the first cylindrical portion, while the metal material layer 103 and the second thermal material layer 102 can form the second cylindrical portion. Preferably, the thermal block 10 according to the first embodiment of the present invention can also have a through hole in the center, which penetrates the first thermal material layer 101, the metal material layer 103, and the second thermal material layer 102. Preferably, the thermal block 10 according to the first embodiment of the present invention may also have a groove in the lower part to form at least two legs, wherein the groove may be formed in a single second thermal material layer 102, or may be formed in both the metal material layer 103 and the second thermal material layer 102, or may be formed in all three of the first thermal material layer 101, the metal material layer 103 and the second thermal material layer 102.

[0056] For example, the thermal block 10c according to the fourth embodiment of the present invention may also have a through hole that penetrates the first cylindrical portion 150 and the second cylindrical portion 160. The thermal block 10b according to the third embodiment of the present invention and the thermal block 10c according to the fourth embodiment of the present invention may also have a groove in the lower part to form at least two legs.

[0057] The thermal fuse 1 of this invention may include any of the aforementioned thermistors. These specially structured thermistors have high thermal conductivity and response sensitivity, thereby significantly improving the thermal response speed of the thermal fuse. The inventors have found through experiments that, compared with existing thermal fuses, by using the thermistors of this invention, the thermal response speed of the thermal fuse can be increased by 24.5%-52.3%, and the thermal response time can be correspondingly reduced to 15-20 seconds. For example, the inventors have found through experiments that by using the thermistor 10 for the thermal fuse according to the first embodiment of this invention, the thermal response speed of the thermal fuse can be increased by 26.7%. The inventors have also found through experiments that by using the thermistor 10a according to the second embodiment of this invention, the thermal response time of the thermal fuse is reduced by 35.0%, from 25.2 seconds to 16.4 seconds. Moreover, the inventors discovered through experiments that the thermal fuse using the thermal block of this utility model can maintain current interruption and thermomechanical performance comparable to existing thermal fuses while improving its thermal response speed. It can pass current interruption and thermomechanical related tests according to current specifications and can pass aging tests.

[0058] Exemplary embodiments of the present invention have been described in detail herein; however, it should be understood that the present invention is not limited to the specific embodiments described and shown above. Various modifications and variations can be made to the present invention by those skilled in the art without departing from its spirit and scope. All such modifications and variations fall within the scope of the present invention. Moreover, all components described herein can be replaced by other technically equivalent components.

Claims

1. A heat-sensitive block for a thermal fuse, the heat-sensitive block configured to thermally deform at a predetermined temperature to thereby interrupt an electrical circuit of the thermal fuse, characterized in that, The thermosensitive block includes a first thermosensitive material layer, a second thermosensitive material layer, and a metal material layer disposed between the first thermosensitive material layer and the second thermosensitive material layer.

2. The heat-sensitive block for a thermal fuse according to claim 1, characterized in that, The metal material layer is a copper sheet.

3. The heat-sensitive block for a thermal fuse according to claim 1, characterized in that, The thermosensitive block is overall cylindrical or frustoconical.

4. The heat-sensitive block for a thermal fuse according to claim 1, characterized in that, The first thermosensitive material layer and the metal material layer form a first cylindrical portion, the second thermosensitive material layer forms a second cylindrical portion, and a diameter of the first cylindrical portion is smaller than a diameter of the second cylindrical portion.

5. The heat-sensitive block for a thermal fuse according to claim 3 or 4, characterized in that A center of the thermosensitive block has a through hole that penetrates the first thermosensitive material layer, the metal material layer, and the second thermosensitive material layer.

6. The heat-sensitive block for a thermal fuse according to claim 5, characterized in that A lower portion of the thermosensitive block has a recess to form at least two legs.

7. A heat-sensitive block for a thermal fuse, the heat-sensitive block being made of a heat-sensitive material and configured to thermally deform at a predetermined temperature to thereby interrupt an electrical circuit of the thermal fuse, characterized in that, The thermosensitive block is cylindrical, and a lower portion of the thermosensitive block has a recess to form at least two legs.

8. The heat-sensitive block for a thermal fuse according to claim 7, characterized in that A center of the thermosensitive block has a through hole.

9. A heat-sensitive block for a thermal fuse, the heat-sensitive block being made of a heat-sensitive material and configured to thermally deform at a predetermined temperature to thereby interrupt an electrical circuit of the thermal fuse, characterized in that, The thermosensitive block is frustoconical.

10. A heat-sensitive block for a thermal fuse according to claim 9, characterized in that A center of the thermosensitive block has a through hole.

11. A heat-sensitive block for a thermal fuse, the heat-sensitive block being made of a heat-sensitive material and configured to thermally deform at a predetermined temperature to thereby interrupt an electrical circuit of the thermal fuse, characterized in that, The thermosensitive block includes a first cylindrical portion and a second cylindrical portion, and a diameter of the first cylindrical portion is smaller than a diameter of the second cylindrical portion.

12. A heat-sensitive block for a thermal fuse according to claim 11, characterized in that A bottom of the first cylindrical portion is disposed at a central position of an upper surface of the second cylindrical portion.

13. A thermal fuse, characterized by The thermal fuse includes the thermosensitive block for a thermal fuse according to any one of claims 1 to 12.

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