Novel double-plate type thermal protector

Abstract

The utility model discloses a novel double-sheet type thermal protector, which comprises a bottom plate assembly, a static contact, a movable contact, a bimetallic strip, a connecting sheet and a shell, the shell is arranged on the bottom plate assembly to form a closed accommodating cavity, and the static contact, the movable contact, the bimetallic strip and the connecting sheet are all arranged in the accommodating cavity. The static contact is arranged at the top end of a first binding post of the bottom plate assembly, a front protruding area protruding downwards is arranged at the front end of the bimetallic strip, a rear protruding area protruding downwards is arranged at the rear end of the bimetallic strip, and the movable contact is arranged on the bottom face of the front protruding area of the bimetallic strip. One end of the connecting piece is connected to the top face of the rear protruding area of the bimetallic strip, the other end of the connecting piece is connected to the top of the shell, and the movable contact and the static contact are correspondingly arranged. According to the utility model, through optimizing the structural design of the bimetallic strip, the damage of electric arc to the bimetallic strip is reduced, the service life of the thermal protector is prolonged, and the thermal protector has high practical value.

Description

Technical Field

[0001] This utility model relates to the field of thermal protectors, specifically a novel dual-plate thermal protector. Background Technology

[0002] A dual-chip thermal protector is a protective device used to prevent equipment from overheating. It is widely used in household appliances, industrial equipment, and electronic equipment. Its core function is to automatically cut off the circuit when the temperature exceeds a set value, thereby preventing equipment damage or fire.

[0003] The working principle of a bimetallic strip is based on the characteristics of a bimetallic strip. The bimetallic strip is composed of two metals with different coefficients of thermal expansion. When the temperature changes, the two metals expand at different rates, causing the strip to bend, which in turn triggers a switch to disconnect the circuit.

[0004] However, in practical applications, bimetallic thermal protectors, as high-power thermal protectors, face a significant problem: in high-power equipment, due to the large operating current, arcing is easily generated when the circuit is disconnected. The high temperature and impact force generated by the arc directly act on the bimetallic strip, causing material damage. This damage further exacerbates the ablation and poor contact of the bimetallic strip, ultimately leading to premature failure of the protector during use, thus affecting its reliability and service life. Utility Model Content

[0005] To address the aforementioned technical problems, this utility model proposes a novel dual-plate thermal protector. By optimizing the structural design of the bimetallic strip, the damage caused by electric arc to the bimetallic strip is effectively reduced, thereby extending the service life of the thermal protector and demonstrating high practical value.

[0006] The main technical solution adopted in this utility model is as follows:

[0007] A novel dual-plate thermal protector includes a base plate assembly, a stationary contact, a moving contact, a bimetallic strip, a connecting piece, and a housing. The housing is mounted on the base plate assembly, forming a closed receiving cavity. The stationary contact, moving contact, bimetallic strip, and connecting piece are all disposed within the receiving cavity. The stationary contact is located at the top of the first terminal of the base plate assembly. The front end of the bimetallic strip has a downwardly protruding front protrusion area, and the rear end of the bimetallic strip has a downwardly protruding rear protrusion area. The moving contact is located on the bottom surface of the front protrusion area of ​​the bimetallic strip. One end of the connecting piece is connected to the top surface of the rear protrusion area of ​​the bimetallic strip, and the other end is connected to the top of the housing. The moving contact is correspondingly positioned to the stationary contact.

[0008] Preferably, the base plate assembly includes a base plate, two glass bodies, two ceramic plates, a first terminal, a second terminal, and a resistance heating plate. The base plate has two glass bodies, and the two ceramic plates are disposed on the upper surface of the base plate and are respectively located above the two glass bodies. The top ends of the first terminal and the second terminal pass through the glass bodies and ceramic plates respectively and are located in the receiving cavity. One end of the resistance heating plate is connected to the top end of the second terminal, and the other end of the resistance heating plate is fixedly connected to the base plate.

[0009] Preferably, the cavity is filled with an inert gas.

[0010] Preferably, the protrusion depths of the front protrusion area and the rear protrusion area are the same.

[0011] Preferably, the protrusion depth of the front protrusion area and the rear protrusion area is 0.6±0.1mm.

[0012] Preferably, both the front protrusion area and the rear protrusion area are formed by stamping from top to bottom.

[0013] Preferably, it also includes a welding tab, which is welded to the upper and lower surfaces of the rear protrusion area of ​​the bimetallic sheet in conjunction with the connecting tab.

[0014] Beneficial Effects: This utility model provides a novel dual-plate thermal protector. By employing a stamping process, rearwardly protruding areas are designed in the front and rear connection regions of the bimetallic strip. The moving contact and connecting piece are welded to these protruding areas, thereby increasing the distance between the bimetallic strip and the contact points of the moving and stationary contacts (i.e., the arc generation location). This design effectively reduces the impact and ablation experienced by the bimetallic strip during arc generation, significantly improving the service life of the protector. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the overall structure of Example 1;

[0016] Figure 2 This is a schematic diagram of the bimetallic sheet in Example 1;

[0017] Figure 3 This is a schematic diagram illustrating the working principle of Example 1;

[0018] In the figure: base plate assembly 1, base plate 1-1, glass body 1-2, ceramic sheet 1-3, first terminal 1-4, second terminal 1-5, resistance heating plate 1-6, stationary contact 2, moving contact 3, bimetallic sheet 4, front protrusion area 4-1, rear protrusion area 4-2, connecting piece 5, housing 6, receiving cavity 7, welding piece 8. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. The description of the specific embodiments below is merely exemplary and should be understood as being used only to explain the present utility model, and not in any way to limit the present utility model or its application or usage.

[0020] It should be noted that when an element is said to be "fixed to" another element, it can be directly on the other element or there may be an intervening element. When an element is said to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. Conversely, when an element is said to be "directly on" another element, there is no intervening element. Conversely, when an element is said to be "directly" connected to another element, there is no intervening element. The terms "vertical," "horizontal," "left," "right," and similar expressions used in this document are for illustrative purposes only.

[0021] In the description of this utility model, it should be understood that the terms "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. Example 1

[0022] like Figure 1-2 As shown, a novel dual-plate thermal protector includes a base plate assembly 1, a stationary contact 2, a moving contact 3, a bimetallic strip 4, a connecting piece 5, and a housing 6. The housing 6 is mounted on the base plate assembly 1, forming a closed receiving cavity 7. The stationary contact 2, the moving contact 3, the bimetallic strip 4, and the connecting piece 5 are all disposed within the receiving cavity 7. The stationary contact 2 is located at the top of the first terminal 1-4 of the base plate assembly 1. The front end of the bimetallic strip 4 has a downwardly protruding front protrusion area 4-1, and the rear end of the bimetallic strip 4 has a downwardly protruding rear protrusion area 4-2. The moving contact 3 is located on the bottom surface of the front protrusion area 4-1 of the bimetallic strip 4. One end of the connecting piece 5 is connected to the top surface of the rear protrusion area 4-2 of the bimetallic strip 4, and the other end is connected to the top of the housing 6. The moving contact 3 is correspondingly disposed to the stationary contact 2.

[0023] like Figure 1As shown, the base plate assembly 1 includes a base plate 1-1, two glass bodies 1-2, two ceramic plates 1-3, a first terminal 1-4, a second terminal 1-5, and a resistance heating plate 1-6. The base plate 1-1 is provided with two glass bodies 1-2, and the two ceramic plates 1-3 are disposed on the upper surface of the base plate 1-1 and are respectively located above the two glass bodies 1-2. The top ends of the first terminal 1-4 and the second terminal 1-5 pass through the glass body 1-2 and the ceramic plate 1-3 respectively and are located in the receiving cavity 7. One end of the resistance heating plate 1-6 is connected to the top end of the second terminal 1-5, and the other end of the resistance heating plate 1-6 is fixedly connected to the base plate 1-1.

[0024] In this embodiment 1, the cavity 7 is filled with inert gas.

[0025] In this embodiment 1, the protrusion depth of the front protrusion area 4-1 and the rear protrusion area 4-2 is the same, generally 0.6±0.1mm.

[0026] In this embodiment 1, both the front protrusion area 4-1 and the rear protrusion area 4-2 are formed by stamping from top to bottom.

[0027] In this embodiment 1, a solder pad 8 is also included. The solder pad 8 is welded to the upper and lower surfaces of the rear protrusion area 4-2 of the bimetallic strip 4 in conjunction with the connecting piece 5. By welding the bimetallic strip 4 between the two, the welding strength is improved, thereby ensuring the reliability of the device.

[0028] The working principle of this utility model:

[0029] When the current in the circuit is within the rated range, the bimetallic strip 4 remains flat, the contacts are closed, the circuit conducts normally, and the equipment operates normally. When the current in the circuit exceeds the set value (i.e., overload), the current passing through the bimetallic strip 4 generates heat due to its resistive characteristics, causing the bimetallic strip 4 to heat up, deform, bend, and flip. When the bimetallic strip 4 bends to a certain extent, the moving contact separates from the stationary contact, thereby cutting off the circuit, stopping the current flow, and protecting the equipment and circuit from damage. When the overload is eliminated, the bimetallic strip gradually cools down and returns to its original state, the moving contact 3 separates from the stationary contact 2 and closes again, and the circuit resumes normal operation, thus repeating the cycle.

[0030] When the bimetallic strip bounces and flips, an electric arc is generated at the contact point between the moving contact 3 and the stationary contact 2 at the moment of power switching. The high-temperature arc splashes onto the bimetallic strip 4, which can damage or even burn the strip, causing the jumping and protection functions of the strip to fail. Therefore, in this invention, the two ends of the bimetallic strip 4 are stamped to form downward convex areas. The connecting piece 5 and the moving contact 3 are respectively installed in the front convex area 4-1 and the rear convex area 4-2 of the bimetallic strip 4, which increases the distance h between the contact points of the bimetallic strip 4 and the moving and stationary contacts 2, thereby reducing the impact and ablation that the bimetallic strip suffers when the arc is generated.

[0031] After testing and verification, the thermal protector made with the bimetallic strip described in Example 1 has significantly reduced the failure rate due to damage to the bimetallic strip during use, effectively improving the service life of the protector.

[0032] It will be apparent to those skilled in the art that this invention is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or essential characteristics of this invention. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of this invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within this invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0033] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A new type of dual piece thermal protector characterized in that, The device includes a base plate assembly, a stationary contact, a moving contact, a bimetallic strip, a connecting piece, and a housing. The housing is disposed on the base plate assembly, forming a closed receiving cavity. The stationary contact, moving contact, bimetallic strip, and connecting piece are all disposed within the receiving cavity. The stationary contact is disposed at the top of the first terminal of the base plate assembly. The front end of the bimetallic strip has a downwardly protruding front protrusion area, and the rear end of the bimetallic strip has a downwardly protruding rear protrusion area. The moving contact is disposed on the bottom surface of the front protrusion area of ​​the bimetallic strip. One end of the connecting piece is connected to the top surface of the rear protrusion area of ​​the bimetallic strip, and the other end is connected to the top of the housing. The moving contact is disposed corresponding to the stationary contact.

2. The new double disc thermal protector according to claim 1, characterized in that, The base plate assembly includes a base plate, two glass bodies, two ceramic plates, a first terminal, a second terminal, and a resistance heating plate. The base plate has two glass bodies, and the two ceramic plates are disposed on the upper surface of the base plate and are respectively located above the two glass bodies. The tops of the first terminal and the second terminal pass through the glass bodies and ceramic plates respectively and are located in the receiving cavity. One end of the resistance heating plate is connected to the top of the second terminal, and the other end of the resistance heating plate is fixedly connected to the base plate.

3. The new type dual piece thermal protector according to claim 1, wherein, The cavity is filled with inert gas.

4. The new type dual piece thermal protector according to claim 1, wherein, The front and rear raised areas have the same height.

5. The new type dual piece thermal protector according to claim 1, wherein, The protrusion height of the front and rear protrusion areas is 0.6±0.1mm.

6. The new dual piece thermal protector of claim 1, wherein, Both the front and rear protruding areas are made by stamping bimetallic sheets from top to bottom.

7. The new type dual piece thermal protector according to claim 1, wherein, It also includes welding tabs, which are welded to the upper and lower surfaces of the rear protrusion area of ​​the bimetallic sheet in conjunction with the connecting tabs.

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