Inflatable temperature sensor
By using the rigid connection between the central shaft and the base plate and the cooperation of the cam micro switch, the problem of inaccurate alarm accuracy of the expansion temperature sensor is solved, realizing high-precision and stable temperature alarm and multi-segment threshold setting, which can adapt to complex working conditions.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- FUZHOU INNOVATION ELECTRONICS SCIE & TECH
- Filing Date
- 2026-02-26
- Publication Date
- 2026-05-29
AI Technical Summary
The expansion-type temperature sensor has a gap between the sliding part and the dial, which leads to inaccurate alarm accuracy and the sliding part is prone to displacement.
The design employs a rotating fit between the central shaft and the base plate, along with a rigid connection to the fixed column. Combined with the design of a cam and a micro switch, it ensures precise alignment between the first pointer and the adjustment pointer. The alarm is triggered by the cam-triggered micro switch. The spring structure eliminates the influence of machining tolerances, and the hysteresis value of the micro switch is adjusted to adapt to different working conditions.
It improves alarm accuracy and stability, reduces production costs, and enables graded alarms with multiple temperature thresholds and the recording of historical highest temperatures, adapting to different working conditions.
Smart Images
Figure CN122108366A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the technical field of temperature sensors, and in particular to expansion-type temperature sensors. Background Technology
[0002] An expansion-type temperature sensor comprises a bulb, a capillary tube, and a Bourdon tube, whose internal cavities form a closed container filled with a working substance (such as nitrogen). The pressure of the working substance is transmitted through the capillary tube to the Bourdon tube, causing it to deform. The Bourdon tube is connected to a central shaft, and the deformation of the Bourdon tube causes the central shaft to rotate, thereby driving a pointer to indicate the measured temperature. A dial that works in conjunction with the pointer has a sliding temperature alarm mechanism. A trigger rod is connected to the central shaft. The trigger rod moves synchronously with the pointer; when the alarm temperature is reached, the trigger rod activates the temperature alarm mechanism, triggering the alarm.
[0003] Reference Figure 1 The temperature alarm mechanism 200 includes a sliding part 210, a pointer part 220, and a trigger part 230 that cooperates with a trigger rod 100. The sliding part 210 is inserted into the dial 30. The temperature alarm mechanism 200 slides arbitrarily around the dial 30 via the sliding part 210. When the pointer and the pointer part 220 point to the same temperature, the trigger rod 100 pushes the trigger part 230 to trigger the alarm. In actual use, there is a gap between the sliding part 210 and the dial 30, which can cause the sliding part 210 to deviate, resulting in a large error in alarm accuracy. Summary of the Invention
[0004] To address the aforementioned technical issues, this application provides an expansion-type temperature sensor.
[0005] This application provides an expansion-type temperature sensor, employing the following technical solution: Expansion-type temperature sensors include: The central axis has a Bourdon tube connected to its lower end and a first pointer connected to its upper end. The dial has a circumferentially distributed scale, the central shaft is rotatably mounted on the dial, and the first pointer points to the scale on the dial; A base plate is rotatably mounted on the central shaft. A fixing column is fixedly mounted on the base plate. An adjustment pointer is connected to the upper end of the fixing column and slides on the dial. A micro switch is mounted on the base plate, and the micro switch is electrically connected to a temperature alarm. A cam is fixedly mounted on the central shaft. When the first pointer and the adjustment pointer point to the same temperature, the cam rotates with the central shaft to activate the micro switch.
[0006] By adopting the above technical solution, before use, the base plate mounted on the central shaft is rotated, driving the fixed column and adjusting pointer to slide to the alarm temperature scale set on the dial, thus completing the alarm threshold setting. During operation, the change in the measured temperature causes the Bourdon tube to deform, driving the central shaft to rotate. The central shaft drives the first pointer to rotate synchronously to point to the corresponding temperature scale. When the first pointer and the adjusting pointer point to the same temperature, the cam fixed on the central shaft rotates with the central shaft to a specific position, activating the micro switch, which in turn triggers the temperature alarm connected to it to realize the alarm. Through the rotational cooperation between the base plate and the central shaft and the rigid connection of the fixed column, slight displacement of the adjusting pointer is avoided, improving the stability of the alarm threshold setting. The cam is fixedly connected to the central shaft, ensuring strict synchronization between the temperature indicated by the first pointer and the triggering action of the cam, greatly improving the alarm accuracy. The "temperature indication" and "alarm triggering" are integrated into the same central shaft transmission system, resulting in a compact structure and high transmission efficiency.
[0007] Optionally, the cam includes a connecting part and a trigger switch part. The connecting part is used to fix the cam to the central shaft. The trigger switch part is used to trigger the micro switch. The trigger switch part extends in a circumferential direction and has a fan-shaped structure. The starting end of the circumference of the fan-shaped structure is aligned with the first pointer. The angle between the circumferential travel of the fan-shaped structure and the dial scale range is equal. When the temperature pointed to by the first pointer is greater than the temperature pointed to by the adjustment pointer, the trigger switch part is kept in the state of triggering the micro switch.
[0008] By adopting the above technical solution, during installation, the cam is fixed to the central shaft through the connecting part, ensuring that the starting end of the circumference of the sector-shaped trigger switch is precisely aligned with the first pointer. After setting the alarm temperature, when the first pointer rotates with the central shaft to align with the adjustment pointer (reaching the set temperature), the sector-shaped trigger switch begins to contact and trigger the micro switch. If the temperature continues to rise, the first pointer continues to rotate, and the sector-shaped trigger switch rotates synchronously with the central shaft, always maintaining the trigger state of the micro switch. The structural design of the sector-shaped trigger switch increases the contact range with the triggering component, improves the stability of the trigger, and the angle between the trigger stroke and the dial scale range is matched, realizing a linear correspondence between temperature changes and triggering actions, further improving alarm accuracy. The design of continuous triggering after the temperature exceeds the set point ensures the continuity of the alarm under high temperature conditions and avoids erroneous operation of repeated alarm start and stop due to temperature fluctuations.
[0009] Optionally, a first spring is provided on the base plate. When the temperatures of the first pointer and the adjustment pointer are the same, the trigger switch presses the button of the micro switch through the first spring.
[0010] By adopting the above technical solution, when the first pointer and the adjustment pointer point to the same temperature, the fan-shaped trigger switch of the cam rotates to the position of the first spring and presses the first spring. After being subjected to force, the first spring undergoes elastic deformation, thereby pressing the button of the micro switch to realize the opening of the micro switch and alarm triggering. When the temperature drops, the cam rotates in the opposite direction with the central shaft, the pressure on the first spring disappears, the first spring resets under its own elastic action, and the micro switch button rebounds to close the alarm. The elastic buffering effect of the first spring avoids rigid impact between the cam and the micro switch button, reduces the mechanical wear of the micro switch, and extends the service life of the sensor. The deformation stroke of the spring can absorb some of the small errors of the cam rotation, improve the fault tolerance of the triggering action, and ensure the accuracy of the triggering timing. The spring structure is simple, easy to install, and does not require a complex transmission mechanism, reducing the assembly difficulty of the overall structure.
[0011] Optionally, a spring shaft is mounted on the base plate, and one end of the first spring is mounted on the spring shaft.
[0012] By adopting the above technical solution, the spring axis provides a fixed fulcrum for the first spring, ensuring the consistency of the spring deformation direction. During reset, the spring deforms in the opposite direction around the spring axis to return to the initial position.
[0013] Optionally, the first spring is integrally formed with a second spring, the connection between the second spring and the first spring is wound around the spring shaft, the first spring and the trigger switch part are in contact, the second spring and the button of the micro switch are in contact, and an adjusting member is provided between the second spring and the first spring to adjust the gap between the second spring and the first spring.
[0014] By adopting the above technical solution, during operation, the cam presses the first spring, and the first spring drives the second spring to deform synchronously through the adjusting component. Since the gap has been precisely adjusted, the second spring can accurately press the micro switch button. When the cam fully lifts the first spring, the second spring just reaches the stroke to trigger the micro switch, avoiding triggering delay or advance caused by tolerance. The adjusting component can eliminate the negative impact of spring processing tolerance, greatly improving the triggering accuracy and ensuring the consistency of the sensor in mass production. The precise calibration of the trigger stroke is achieved through gap adjustment, reducing the requirements for spring processing accuracy, thereby reducing production costs.
[0015] Optionally, the adjusting element is a set screw, which is threadedly connected to the second spring plate, and one end of the set screw contacts the first spring plate.
[0016] By adopting the above technical solution, during the assembly and calibration stage, the set screw is rotated to adjust the gap between the first and second spring plates. After adjustment to the appropriate position, the self-locking characteristic of the thread keeps the set screw in the current position, preventing the gap from changing during use. The thread adjustment method of the set screw can achieve fine adjustment of the gap with high adjustment accuracy. The set screw structure is simple, low cost, and convenient adjustment operation, which improves assembly and maintenance efficiency.
[0017] Optionally, a travel groove is provided on the base plate, and the spring shaft is slidably installed in the travel groove. By changing the position of the spring shaft in the travel groove, the hysteresis value triggered by the micro switch is adjusted.
[0018] By adopting the above technical solution, and based on actual working conditions (e.g., increasing the hysteresis value in high-temperature environments to avoid frequent alarms, and decreasing the hysteresis value in normal-temperature environments to improve sensitivity), the position of the sliding spring shaft within the stroke groove is determined as follows: The displacement difference between the action position (triggering on / off moment) and the reset position (releasing off / on moment) of the microswitch drive rod is called the differential stroke. Under the inherent differential stroke, the hysteresis value can be changed by manually sliding the spring shaft within the stroke groove. To increase the hysteresis value, the spring shaft is moved closer to the cam, so that the cam needs to rotate a larger angle to disengage from the first spring when rotating in the reverse direction, meaning the temperature needs to drop more to clear the alarm. To decrease the hysteresis value, the spring shaft is moved away from the cam. After adjustment, the spring shaft position is fixed, achieving adjustable trigger hysteresis value. This allows the sensor to adapt to different operating conditions, improving the product's versatility. The stroke groove design is simple, the spring shaft slides smoothly, and the adjustment operation is convenient, requiring no disassembly of the overall structure. Optionally, a second pointer is rotatably mounted on the central shaft. The second pointer is used to point to the highest temperature value. A protrusion is mounted on the first pointer. When the first pointer rotates, the protrusion drives the second pointer to rotate.
[0019] By adopting the above technical solution, during operation, the first pointer rotates with the central axis to indicate the real-time temperature. When the temperature rises, the protrusion on the first pointer pushes the second pointer to rotate synchronously, so that the second pointer always points to the current highest temperature. When the temperature drops, the first pointer rotates in the opposite direction, the protrusion disengages from the second pointer, and the second pointer remains at the highest temperature mark and no longer rotates. If it is necessary to reset the second pointer, it can be manually rotated to the initial position, realizing the function of recording the historical highest temperature, and providing data support for subsequent equipment operation condition analysis and temperature anomaly tracing.
[0020] Optionally, multiple cams are provided along the axial direction of the central axis, and at least one base plate is installed between two adjacent cams.
[0021] By adopting the above technical solution, multi-stage temperature threshold hierarchical alarm is achieved, which is adapted to the early warning and alarm requirements of different temperature levels under complex working conditions, improves the functional applicability of the sensor, and integrates multiple base plates on the central axis. The structure is compact and does not require increasing the overall size of the sensor, saving installation space. Each base plate works independently and does not interfere with each other, ensuring the accuracy and reliability of multi-stage alarms. The number of base plates can be increased or decreased according to needs, which has certain modular design advantages and can adapt to different alarm requirement scenarios.
[0022] In summary, this application includes at least one of the following beneficial effects: 1. By using the rotational engagement between the base plate and the central shaft and the rigid connection of the fixed column, slight displacement of the adjustment pointer is avoided, thus improving the stability of the alarm threshold setting; 2. The first and second springs, through the cooperation of the adjustment components, significantly improve the triggering accuracy, ensuring the consistency of the sensor in mass production. The precise calibration of the trigger stroke is achieved through gap adjustment, reducing the requirements for the processing accuracy of the springs and thus reducing production costs. Attached Figure Description
[0023] Figure 1 This is a structural diagram of the related technology; Figure 2 This is a schematic diagram of the overall structure of an embodiment of this application; Figure 3 This is a schematic diagram of the dial structure according to an embodiment of this application; Figure 4 This is a schematic diagram illustrating the contact between the cam and the first spring in an embodiment of this application; Figure 5 This is a schematic diagram of the structure of all the cams distributed along the central axis in the embodiments of this application; Figure 6 This is a schematic diagram of the overall structure of the micro switch on the base plate according to an embodiment of this application; Figure 7 This is a top view of the micro switch on the base plate according to an embodiment of this application; Figure 8 This is a schematic diagram showing the installation positions of the first and second pointers in an embodiment of this application.
[0024] Explanation of reference numerals in the attached drawings: 10, Bourdon tube; 20, central shaft; 21, first pointer; 211, protrusion; 22, cut surface; 23, bolt; 24, second pointer; 30, dial; 40, base plate; 41, fixing post; 42, adjusting pointer; 43, first spring; 44, spring shaft; 441, resistance ring; 45, second spring; 46, set screw; 47, stroke groove; 50, micro switch; 51, button; 60, cam; 61, connecting part; 62, trigger switch part; 63, clearance groove; 100, trigger rod; 200, temperature alarm mechanism; 210, sliding part; 220, pointer part; 230, trigger part. Detailed Implementation
[0025] The following is in conjunction with the appendix Figure 2 - Appendix Figure 8 This application will be described in further detail.
[0026] This application discloses an expansion-type temperature sensor. (Refer to...) Figure 2 The expansion-type temperature sensor includes a Bourdon tube 10, a central shaft 20, a dial 30, a base plate 40, a micro switch 50, and a cam 60. The central shaft 20 is rotatably mounted at the center of the dial 30, which has circumferentially distributed scales to provide a reference for temperature indication. The lower end of the central shaft 20 is fixedly connected to one end of the Bourdon tube 10 of the expansion-type temperature sensor, and can receive the deformation driving force of the Bourdon tube 10 caused by temperature changes. The upper end is fixedly connected to a first pointer 21, which can deflect synchronously with the rotation of the central shaft 20 and point to the corresponding scale on the dial 30, thereby realizing real-time temperature indication.
[0027] Reference Figure 2 and Figure 3 A base plate 40 is fitted onto a central shaft 20 and can rotate relative to the central shaft 20. An upwardly extending fixing post 41 is fixedly mounted on the base plate 40. An adjustment pointer 42 is connected to the upper end of the fixing post 41. The adjustment pointer 42 is located above the dial 30 and can slide circumferentially along the dial 30 as the base plate 40 rotates, thereby setting the alarm temperature threshold. A micro switch 50 is fixedly mounted on the upper or lower surface of the base plate 40 and is electrically connected to the temperature alarm, forming an alarm trigger circuit. The temperature alarm can be mounted on the base plate 40 or externally.
[0028] Reference Figure 4 The cam 60 is fixedly mounted on the central shaft 20 by fasteners. When the first pointer 21 rotates with the central shaft 20 to the same temperature scale as the adjusting pointer 42, the cam 60 rotates synchronously with the central shaft 20 to the trigger position, thereby activating the micro switch 50 to trigger the temperature alarm.
[0029] Reference Figure 4 and Figure 5 To improve triggering stability and accuracy, the cam 60 specifically includes a connecting part 61 and a trigger switch part 62. The connecting part 61 is an annular structure sleeved on the central shaft 20. The central shaft 20 has a cut surface 22. The inner hole of the connecting part 61 fits with the cut surface 22. The fastener is a bolt 23. The bolt 23 is threadedly connected to the connecting part 61. One end of the bolt 23 is pressed against the cut surface 22, so that the cam 60 and the central shaft 20 are fixedly connected, ensuring that there is no relative rotation between the two. The trigger switch 62 extends in a circumferential direction and has a fan-shaped structure. The starting end of the circumference of the fan-shaped structure is precisely aligned with the pointing direction of the first pointer 21, and the circumferential travel of the fan-shaped structure is equal to the central angle corresponding to the scale range of the dial 30. This makes the rotational travel of the trigger switch 62 perfectly match the indicating travel of the first pointer 21. When the temperature pointed to by the first pointer 21 is greater than the temperature set by the adjusting pointer 42, the trigger switch 62 can maintain continuous contact with the trigger part 230, thereby keeping the micro switch 50 in a continuously triggered state. This ensures the continuity of the alarm in a high-temperature environment and avoids repeated alarm start-stop due to temperature fluctuations.
[0030] Reference Figure 4 and Figure 5 To achieve multi-stage temperature level alarm, multiple cams 60 are arranged along the axial direction of the central shaft 20. One or two base plates 40 are arranged between adjacent cams 60. Each base plate 40 is equipped with a fixed column 41 (of varying heights), an adjustment pointer 42, and a micro switch 50. Each base plate 40 can be independently rotated to set different alarm temperature thresholds. When the first pointer 21 rotates to the set temperature of each adjustment pointer 42 in sequence, the cam 60 triggers the micro switch 50 on the corresponding base plate 40 in sequence to achieve multi-stage level alarm. Moreover, each base plate 40 works independently without interfering with each other, and the structure is compact without increasing the overall volume.
[0031] Reference Figure 4 and Figure 6The base plate 40 is also provided with a first spring piece 43, which is mounted on the base plate 40 via a spring piece shaft 44. The spring piece shaft 44 is fixed to the base plate 40. One end of the first spring piece 43 is sleeved on the spring piece shaft 44 and can rotate around the spring piece shaft 44, so that the first spring piece 43 can undergo elastic deformation with the spring piece shaft 44 as the fulcrum. When the first pointer 21 and the adjusting pointer 42 point to the same temperature, the trigger switch part 62 of the cam 60 rotates to contact the free end of the first spring piece 43 and presses the first spring piece 43. After the first spring piece 43 is deformed by force, it presses the button 51 of the micro switch 50, realizing the opening of the micro switch 50. When the temperature drops, the cam 60 rotates in the opposite direction, and the first spring piece 43 resets under its own elastic action. The button 51 of the micro switch 50 rebounds and closes, completing the disconnection of the alarm circuit. The end of the first spring piece 43 that contacts the cam 60 is warped to facilitate the contact or separation of the first spring piece 43 and the cam 60.
[0032] Reference Figure 6 and Figure 7 To eliminate the influence of machining tolerances on triggering accuracy, a first spring 43 is connected to a second spring 45. The first spring 43 and the second spring 45 are integrally formed, and their connection is wound around the spring shaft 44, forming a double-spring linkage structure. The free end of the first spring 43 faces the cam 60 and can contact the trigger switch part 62, while the free end of the second spring 45 faces the button 51 of the micro switch 50 and contacts it accordingly. An adjusting element is provided between the second spring 45 and the first spring 43. A set screw 46 is used as the adjusting element. The set screw 46 is threadedly connected to the second spring 45, and one end of the set screw 46 passes through the second spring 45 and contacts the first spring 43. By rotating the set screw 46, the gap between the second spring 45 and the first spring 43 can be adjusted, and the machining tolerance is eliminated by the set screw 46.
[0033] Reference Figure 7 Meanwhile, a radially extending travel groove 47 is provided on the base plate 40, and the spring shaft 44 is slidably installed in the travel groove 47. A resistance ring 441 is fixedly installed on the spring shaft 44. The large friction between the resistance ring 441 and the base plate 40 can fix the spring shaft 44 to the base plate 40. When manually pushing the spring shaft 44, force is required to move the spring shaft 44.
[0034] The displacement difference between the actuating position (the instant of triggering on / off) and the reset position (the instant of releasing off / on) of the microswitch drive rod of the microswitch 50 is called the differential stroke. Under the inherent differential stroke, the hysteresis value of the temperature can be changed by manually sliding the position of the spring shaft 44 in the stroke groove 47. By changing the position of the spring shaft 44 in the stroke groove 47, the relative distance between the first spring 43 and the cam 60 can be adjusted, thereby adjusting the hysteresis value triggered by the microswitch 50, that is, the difference between the alarm trigger temperature and the alarm deactivation temperature. The sliding adjustment of the spring shaft 44, based on the inherent differential stroke, realizes the on-demand adjustment of the overall trigger hysteresis value, ultimately meeting the alarm sensitivity requirements under different operating conditions. For example, in a high-temperature environment, the hysteresis value can be increased to avoid frequent alarms by moving the spring shaft 44 closer to the cam 60; in a normal-temperature environment, the hysteresis value can be decreased to improve sensitivity by moving the spring shaft 44 away from the cam 60.
[0035] Reference Figure 8 To record the highest historical temperature, a second pointer 24 is rotatably mounted on the central shaft 20 or the watch cover. The rotation centers of the second pointer 24 and the first pointer 21 coincide. A protrusion 211 is integrally formed on the first pointer 21, which faces the second pointer 24. When the temperature rises, the first pointer 21 rotates with the central shaft 20, and the protrusion 211 pushes the second pointer 24 to rotate synchronously, so that the second pointer 24 always points to the current highest temperature scale. When the temperature drops, the first pointer 21 rotates in the opposite direction, the protrusion 211 disengages from the second pointer 24, and the second pointer 24 remains at the highest temperature scale. If a reset is required, the second pointer 24 can be manually moved to the initial position.
[0036] The implementation principle of the expansion-type temperature sensor in this application embodiment is as follows: Before use, rotate the base plate 40 according to the alarm requirements to drive the adjustment pointer 42 to slide to the corresponding scale on the dial 30 to complete the threshold setting. If the hysteresis value needs to be adjusted, the spring shaft 44 can be slid to a suitable position and fixed. If there is a machining tolerance, the spring gap can be adjusted by rotating the set screw 46. During operation, the change in the measured temperature causes the pressure of the working substance in the closed container to change, which is transmitted to the Bourdon tube 10 through the capillary tube to cause it to deform. The Bourdon tube 10 drives the central shaft 20 to rotate, causing the first pointer 21 to deflect to indicate the real-time temperature. At the same time, the cam 60 rotates synchronously with the central shaft 20. When the first pointer 21 is aligned with the adjustment pointer 42, the cam 60 triggers the micro switch 50 through the first spring 43, and the temperature alarm sounds. When the temperature continues to rise, the cam 60 remains in the triggered state. After the temperature drops, the first spring 43 and the second spring 45 reset and turn off the alarm. During the temperature rise process, the first pointer 21 pushes the second pointer 24 through the protrusion 211 to record the highest temperature. If it is a multi-base plate 40 structure, multi-stage temperature graded alarm can be realized. The overall structure effectively avoids the problem of adjusting component displacement in existing technologies through the precise connection and coordinated cooperation of various components, thus improving alarm accuracy and stability. It also has multi-functional adaptability such as hysteresis adjustment, maximum temperature recording, and multi-segment alarm, making it suitable for a wide range of scenarios.
[0037] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.
Claims
1. An expansion-type temperature sensor, characterized in that, include: The central shaft (20) is connected to a Bourdon tube (10) at its lower end and to a first pointer (21) at its upper end. The dial (30) has a circumferentially distributed scale, the central shaft (20) is rotatably mounted on the dial (30), and the first pointer (21) points to the scale of the dial (30); The base plate (40) is rotatably mounted on the central shaft (20). A fixing column (41) is fixedly mounted on the base plate (40). An adjustment pointer (42) is connected to the upper end of the fixing column (41). The adjustment pointer (42) slides on the dial (30). A micro switch (50) is mounted on the base plate (40), and the micro switch (50) is electrically connected to a temperature alarm. The cam (60) is fixedly mounted on the central shaft (20). When the first pointer (21) and the adjustment pointer (42) point to the same temperature, the cam (60) rotates with the central shaft (20) to open the micro switch (50).
2. The expansion-type temperature sensor according to claim 1, characterized in that, The cam (60) includes a connecting part (61) and a trigger switch part (62). The connecting part (61) is used to fix the cam (60) to the central shaft (20). The trigger switch part (62) is used to trigger the micro switch (50). The trigger switch part (62) extends in the circumferential direction and has a fan-shaped structure. The starting end of the circumference of the fan-shaped structure is aligned with the first pointer (21). The angle between the circumferential travel of the fan-shaped structure and the scale range of the dial (30) is equal. When the temperature pointed to by the first pointer (21) is greater than the temperature pointed to by the adjustment pointer (42), the trigger switch part (62) is kept in the state of triggering the micro switch (50).
3. The expansion-type temperature sensor according to claim 2, characterized in that, The base plate (40) is provided with a first spring (43). When the temperature of the first pointer (21) and the adjustment pointer (42) are the same, the trigger switch (62) presses the button (51) of the micro switch (50) through the first spring (43).
4. The expansion-type temperature sensor according to claim 3, characterized in that, A spring shaft (44) is installed on the base plate (40), and one end of the first spring (43) is installed on the spring shaft (44).
5. The expansion-type temperature sensor according to claim 4, characterized in that, The first spring (43) is integrally formed with a second spring (45). The connection between the second spring (45) and the first spring (43) is wound around the spring shaft (44). The first spring (43) is in contact with the trigger switch (62). The second spring (45) is in contact with the button (51) of the micro switch (50). An adjusting member is provided between the second spring (45) and the first spring (43) to adjust the gap between the second spring (45) and the first spring (43).
6. The expansion-type temperature sensor according to claim 5, characterized in that, The adjusting component is a set screw (46), which is threadedly connected to the second spring (45), and one end of the set screw (46) is in contact with the first spring (43).
7. The expansion-type temperature sensor according to claim 4, characterized in that, The base plate (40) has a stroke groove (47), and the spring shaft (44) is slidably installed in the stroke groove (47). By changing the position of the spring shaft (44) in the stroke groove (47), the hysteresis value triggered by the micro switch (50) is adjusted.
8. The expansion-type temperature sensor according to claim 1, characterized in that, A second pointer (24) is rotatably mounted on the central shaft (20). The second pointer (24) is used to point to the highest temperature value. A protrusion (211) is mounted on the first pointer (21). When the first pointer (21) rotates, the protrusion (211) drives the second pointer (24) to rotate.
9. The expansion-type temperature sensor according to claim 1, characterized in that, Multiple cams (60) are provided along the axial direction of the central shaft (20), and at least one base plate (40) is installed between two adjacent cams (60).