A temperature detection device for a thermistor

Abstract

This invention relates to the field of thermistor temperature measurement technology, specifically to a thermistor temperature measurement and detection device, comprising a substrate and a handheld component. A resistor to be measured is mounted on the outer wall of the substrate. An inner cylinder is fixedly connected to the end of the handheld component. A top magnetic block is fixedly connected inside the inner cylinder. A probe switching mechanism is provided inside the inner cylinder. The probe switching mechanism includes a rotating rod rotatably connected inside the inner cylinder. A gear is fixedly connected to the outer wall of the rotating rod. A push rod is slidably connected to the inner cylinder. A rack is provided at the end of the push rod. By setting a linkage structure between a cleaning component with a cleaning brush and a swing arm, when the operator presses down on the handheld component, the swing arm can simultaneously drive the two cleaning components to move to both sides. The cleaning brush directly cleans the surface of the resistor to be measured, eliminating the need for additional manual cleaning and effectively avoiding the obstruction of heat conduction by dust residue, thus laying a precise foundation for subsequent temperature measurement.

Description

Technical Field

[0001] This invention relates to the field of thermistor temperature measurement technology, specifically to a temperature detection device for thermistors. Background Technology

[0002] Thermistors, as temperature-sensitive semiconductor components, are widely used in temperature detection applications in electronic devices, industrial control, medical devices, and other fields.

[0003] Existing thermistor temperature probes have poor adaptability and insufficient temperature scenario adaptation. Most existing devices use a single-structure probe, which cannot be freely switched according to the surface temperature of the thermistor. For example, in high-temperature environments, when the thermistor itself has a high heating power, using a large contact area probe alone can easily absorb a large amount of heat through thermal conduction, generating a thermal load effect that causes the local temperature drop of the thermistor, leading to inaccurate temperature measurement. In low-temperature or normal-temperature environments, using a small contact area probe will result in uneven contact with the thermistor, easily generating local temperature differences, interfering with the original temperature field, and failing to accurately reflect the actual working temperature, thus affecting the temperature measurement accuracy. At the same time, after long-term use, the surface of the thermistor is prone to dust and impurities. Most existing temperature measurement devices do not have an automatic cleaning mechanism, requiring manual cleaning before thermistor temperature measurement. This is not only cumbersome, but if the cleaning is not thorough, residual impurities will hinder heat conduction, leading to deviations in subsequent temperature measurement results. Summary of the Invention

[0004] The purpose of this invention is to provide a temperature detection device for a thermistor, thereby solving the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a temperature measuring device for a thermistor, comprising a substrate and a handheld component. A resistor to be measured is mounted on the outer wall of the substrate. An inner cylinder is fixedly connected to the end of the handheld component. A top magnetic block is fixedly connected inside the inner cylinder. A probe switching mechanism is provided inside the inner cylinder. The probe switching mechanism includes a rotating rod rotatably connected inside the inner cylinder. A gear is fixedly connected to the outer wall of the rotating rod. A push rod is slidably connected to the inner cylinder. A rack is provided at the end of the push rod. The rack and gear are meshed. A horizontal plate is fixedly connected to the end of the rotating rod. A protrusion is fixedly connected to the outer wall of the horizontal plate. A conical temperature measuring probe and a circular temperature measuring probe are slidably connected to both sides of the horizontal plate, respectively.

[0006] Preferably, a first spring is sleeved on the outer wall of the conical temperature probe, and a first magnetic block is fixedly connected to the end of the conical temperature probe. The magnetic poles of the first magnetic block are the same as the magnetic poles of the top magnetic block. A second spring is sleeved on the outer wall of the circular temperature probe, and a second magnetic block is fixedly connected to the end of the circular temperature probe. The magnetic poles of the second magnetic block are the same as the magnetic poles of the top magnetic block.

[0007] Preferably, a base plate is fixedly connected to the inside of the inner cylinder, a scraper is fixedly connected to the base plate, and a probe cleaning mechanism is provided on the base plate.

[0008] Preferably, the probe cleaning mechanism includes a liquid storage tank fixedly connected to the base plate. A sliding groove is provided on the side wall of the liquid storage tank. A pressing member is slidably connected inside the sliding groove. A connecting column is fixedly connected to the outer side wall of the pressing member. A pressure plate is fixedly connected to the end of the connecting column away from the pressing member. A connecting rod is rotatably connected to the side of the pressing member away from the connecting column.

[0009] Preferably, a slide rail is provided on the base plate, an absorbent sponge is slidably connected inside the slide rail, a pressure spring is fixedly connected to the outer wall of the absorbent sponge, the end of the pressure spring away from the absorbent sponge is in contact with the inner wall of the slide rail, the outer wall of the absorbent sponge is rotatably connected to the other end of the connecting rod, a conduit is slidably connected through the inside of the liquid storage tank, an inlet hole is provided on the conduit, and the end of the conduit away from the inlet hole is connected to the absorbent sponge.

[0010] Preferably, a shield is fixedly connected to the outer side wall of the handheld component, and two sets of swing arms are rotatably connected to the shield. A cleaning component is rotatably connected to each of the two sets of swing arms, and a resistance pretreatment mechanism is provided on the cleaning component.

[0011] Preferably, the resistance pretreatment mechanism includes a cleaning brush fixedly connected to a cleaning component, a plurality of rollers fixedly connected to the outer side wall of the cleaning component, an inner groove opened inside one of the two cleaning components, a trigger magnetic block slidably connected inside the inner groove, two support frames fixedly connected to the outer side wall of one of the two cleaning components, and a telescopic rod fixedly connected to each of the two support frames, with the end of the telescopic rod away from the support frame fixedly connected to the trigger magnetic block.

[0012] Preferably, a magnetic plate is fixedly connected to the side wall of the push rod, the magnetic plate slides through to the outside of the shield, and a pressing spring is fixedly connected to the outer side wall of the push rod, the other end of the pressing spring being in contact with the inner cylinder.

[0013] Preferably, the side wall of the shield is provided with a flip door, and the inner cylinder is provided with a flip opening.

[0014] Compared with the prior art, the beneficial effects of the present invention are:

[0015] 1. Through the setting of the probe switching mechanism, the probe can be automatically switched according to the surface temperature of the resistor under test. When the surface temperature of the resistor under test is low or at room temperature, the circular probe makes contact with the resistor under test. Its large contact area can be evenly attached to the resistor under test, reducing local temperature differences and avoiding interference with the original temperature field. When the surface temperature of the resistor under test is high, the temperature sensor controls the telescopic rod to trigger the magnetic attraction transmission, driving the rotating rod to rotate 180° to switch to the conical probe. The small contact area can greatly reduce heat absorption according to Fourier's law of heat conduction, avoid the "heat load effect", and ensure the authenticity of the temperature measurement results under different temperature scenarios.

[0016] 2. By setting up a linkage structure between the cleaning component with a cleaning brush and the swing arm, when the operator presses down on the handpiece, the swing arm can simultaneously drive the two cleaning components to move to both sides. The cleaning brush directly cleans the surface of the resistor to be tested, eliminating the need for additional manual cleaning and effectively avoiding the obstruction of heat conduction by dust residue, thus laying an accurate foundation for subsequent temperature measurement. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of the present invention. Figure 1 ;

[0018] Figure 2 This is a schematic diagram of the external structure of the present invention;

[0019] Figure 3 This is a schematic diagram of the cleaning component structure of the present invention. Figure 1 ;

[0020] Figure 4 This is a schematic diagram of the cleaning component structure of the present invention. Figure 2 ;

[0021] Figure 5 This is a schematic diagram of the internal structure of the inner cylinder of the present invention. Figure 1 ;

[0022] Figure 6 This is a schematic diagram of the internal structure of the inner cylinder of the present invention. Figure 2 ;

[0023] Figure 7 for Figure 6 Enlarged view of A in the middle;

[0024] Figure 8 This is a schematic diagram of the overall structure of the inner cylinder of the present invention;

[0025] Figure 9 This is a schematic diagram of the bottom structure of the present invention;

[0026] Figure 10 This is a schematic diagram of the planar structure of the present invention. Figure 1 ;

[0027] Figure 11 This is a schematic diagram of the planar structure of the present invention. Figure 2 .

[0028] The components represented by each number in the attached diagram are listed below: 1. Base plate; 2. Resistor to be tested; 3. Shield; 4. Handheld component; 5. Swing arm; 6. Flip-up door; 7. Cleaning component; 8. Cleaning brush; 9. Support frame; 10. Telescopic rod; 11. Inner groove; 12. Trigger magnet; 13. Roller; 14. Magnetic plate; 15. Inner cylinder; 16. Push rod; 17. Pressing spring; 18. Rotating rod; 19. Top magnet; 20. Lowering component. ; 21. Rack; 22. Protrusion; 23. Gear; 24. Horizontal plate; 25. Conical temperature probe; 26. Circular temperature probe; 27. First spring; 28. First magnet; 29. ​​Second magnet; 30. Second spring; 31. Base plate; 32. Scraper; 33. Pressure spring; 34. Absorbent sponge; 35. Liquid storage tank; 36. Pressure plate; 37. Conduit; 38. Liquid inlet; 39. Connecting column; 40. Connecting rod. Detailed Implementation

[0029] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] Example 1: Refer to Figures 1-11 A temperature detection device for a thermistor includes a substrate 1 and a handheld component 4. A resistor 2 to be measured is mounted on the outer wall of the substrate 1. An inner cylinder 15 is fixedly connected to the end of the handheld component 4. A top magnetic block 19 is fixedly connected inside the inner cylinder 15. A probe switching mechanism is provided inside the inner cylinder 15. The probe switching mechanism includes a rotating rod 18 rotatably connected inside the inner cylinder 15. A gear 23 is fixedly connected to the outer wall of the rotating rod 18. A push rod 16 is slidably connected to the inner cylinder 15. A rack 21 is provided at the end of the push rod 16. The rack 21 and the gear 23 are meshed. A horizontal plate 24 is fixedly connected to the end of the rotating rod 18. A protrusion 22 is fixedly connected to the outer wall of the horizontal plate 24. A conical temperature probe 25 and a circular temperature probe 26 are slidably connected to both sides of the horizontal plate 24, respectively.

[0031] A first spring 27 is sleeved on the outer wall of the conical temperature probe 25, and a first magnetic block 28 is fixedly connected to the end of the conical temperature probe 25. The magnetic poles of the first magnetic block 28 are the same as the magnetic poles of the top magnetic block 19. A second spring 30 is sleeved on the outer wall of the circular temperature probe 26, and a second magnetic block 29 is fixedly connected to the end of the circular temperature probe 26. The magnetic poles of the second magnetic block 29 are the same as the magnetic poles of the top magnetic block 19.

[0032] The inner cylinder 15 is fixedly connected to a base plate 31, a scraper 32 is fixedly connected to the base plate 31, and a probe cleaning mechanism is provided on the base plate 31.

[0033] In this embodiment, when measuring the temperature of the resistor 2 under test, the operator can first align the two cleaning components 7 with the resistor 2 under test, and then press down the handheld component 4. During the pressing down of the handheld component 4, the two sets of swing arms 5 will flip to both sides, thereby pushing the two cleaning components 7 to move to both sides synchronously. When the cleaning components 7 move, the cleaning brush 8 attached to them will simultaneously clean the surface of the resistor 2 under test to avoid dust residue affecting the subsequent detection accuracy. At the same time, one of the two cleaning components 7 has a built-in detection sensor, which will detect the surface temperature of the resistor 2 under test in real time.

[0034] If the surface temperature of the resistor 2 under test is low or at room temperature at this time, continue to press down on the handheld part 4. When the swing arm 5 drives the cleaning part 7 to move completely to both sides of the shield 3, the circular temperature probe 26 will contact the surface of the resistor 2 under test and start measuring the temperature. The circular temperature probe 26 has a large contact area and can make uniform contact with the surface of the resistor 2 under test. This can reduce the local temperature difference between the probe and the resistor 2 under test, avoid interfering with the original temperature field of the resistor 2 under test, and thus more accurately reflect its actual working temperature.

[0035] Under the push of the swing arm 5, the two cleaning components 7 move and clean the surface of the resistor 2 to be tested. At the same time, the temperature sensor inside one of the two cleaning components 7 will detect the surface of the resistor 2 to be tested. If the surface temperature of the resistor 2 to be tested is high, exceeding 130 degrees, the temperature sensor will control the telescopic rod 10 to extend, allowing the trigger magnet 12 to protrude from the inner groove 11 (this is existing technology and will not be elaborated further). As the handheld component 4 continues to press down, after the two swing arms 5 have driven the cleaning components 7 to move completely to both sides of the shield 3, the trigger magnet 12 exposed in the inner groove 11 will move to the side of the magnetic plate 14. Since the magnetic poles of the trigger magnet 12 and the magnetic plate 14 are opposite, when the two are close to each other, a large magnetic attraction force will be generated. The adsorption push rod 16 overcomes the elastic force of the pressing spring 17 and moves towards the magnetic plate 14. Because the rack 21 and the gear 23 are meshed. When the push rod 16 moves, it drives the rack 21 to move synchronously, which in turn drives the rotating rod 18 to rotate 180 degrees counterclockwise through the gear 23. After the rotating rod 18 rotates, the conical temperature probe 25 will replace the circular temperature probe 26 and move to the position directly below the top magnetic block 19. At this time, a repulsive magnetic force will be generated between the top magnetic block 19 and the first magnetic block 28, pushing the conical temperature probe 25 to overcome the elastic force of the first spring 27 and move downward, extending out of the inner cylinder 15 to contact the surface of the resistor 2 under test for temperature measurement. In a high-temperature environment, the resistor 2 under test has a high heat generation power. If the probe contact area is too large, it will absorb a large amount of heat through heat conduction, resulting in a heat load effect that causes the local temperature of the resistor 2 under test to drop, ultimately causing inaccurate temperature measurement. However, the conical temperature probe 25 has a small contact area at its tip. According to Fourier's law of heat conduction, it can significantly reduce the heat absorbed from the resistor 2 under test, effectively improving the accuracy of temperature measurement.

[0036] Example 2: Refer to Figures 1-11 The probe cleaning mechanism includes a liquid storage tank 35 fixedly connected to the base plate 31. A sliding groove is provided on the side wall of the liquid storage tank 35. A pressing member 20 is slidably connected inside the sliding groove. A connecting column 39 is fixedly connected to the outer side wall of the pressing member 20. A pressure plate 36 is fixedly connected to the end of the connecting column 39 away from the pressing member 20. A connecting rod 40 is rotatably connected to the side of the pressing member 20 away from the connecting column 39.

[0037] A slide rail is provided on the base plate 31. An absorbent sponge 34 is slidably connected inside the slide rail. A pressure spring 33 is fixedly connected to the outer wall of the absorbent sponge 34. The end of the pressure spring 33 away from the absorbent sponge 34 contacts the inner wall of the slide rail. The outer wall of the absorbent sponge 34 is rotatably connected to the other end of the connecting rod 40. A conduit 37 is slidably connected through the inside of the liquid storage tank 35. An inlet hole 38 is provided on the conduit 37. The end of the conduit 37 away from the inlet hole 38 is connected to the absorbent sponge 34.

[0038] A shield 3 is fixedly connected to the outer wall of the handheld part 4. Two sets of swing arms 5 are rotatably connected to the shield 3. A cleaning part 7 is rotatably connected to each set of swing arms 5. A resistance pretreatment mechanism is provided on the cleaning part 7.

[0039] The resistance pretreatment mechanism includes a cleaning brush 8 fixedly connected to the cleaning component 7. Multiple rollers 13 are fixedly connected to the outer wall of the cleaning component 7. One of the two cleaning components 7 has an inner groove 11. A trigger magnet 12 is slidably connected inside the inner groove 11. Two support frames 9 are fixedly connected to the outer wall of one of the two cleaning components 7. A telescopic rod 10 is fixedly connected to each of the two support frames 9. The end of the telescopic rod 10 away from the support frame 9 is fixedly connected to the trigger magnet 12.

[0040] A magnetic plate 14 is fixedly connected to the side wall of the push rod 16. The magnetic plate 14 slides through to the outside of the shield 3. A pressing spring 17 is fixedly connected to the outer side wall of the push rod 16. The other end of the pressing spring 17 contacts the inner cylinder 15.

[0041] The side wall of the shield 3 is provided with a flip door 6, and the inner cylinder 15 is provided with a flip opening.

[0042] In this embodiment, since the base plate 31 is positioned on the rotation switching path between the conical temperature probe 25 and the circular temperature probe 26, when the rotating rod 18 rotates counterclockwise to switch between the two probes, the two probes will come into contact with the scraper 32 during the rotation process. The scraper 32 will then scrape and clean the contact surfaces of the two probes to prevent impurities from adhering and affecting the subsequent detection accuracy. At the same time, thanks to the design of the protrusion 22, when the conical temperature probe 25 rotates counterclockwise to replace the circular temperature probe 26, the protrusion 22 will rotate synchronously with the conical temperature probe 25. During the rotation, the contact slope of the protrusion 22 will first come into contact with the pressure plate 36 and press down on the pressure plate 36 during continuous movement. After the pressure plate 36 is pressed down, it will drive the pressing member 20 to move down through the connecting column 39. The pressing member 20 will then push the adsorption sponge 34 away from the liquid storage tank 35 through the connecting rod 40 until the adsorption sponge 34 reaches As the conical temperature probe 25 rotates, the movement of the adsorption sponge 34 causes the conduit 37 to move synchronously, allowing the liquid inlet 38 on the conduit 37 to enter the storage tank 35. After the liquid inlet 38 enters the storage tank 35, the UV-curable silver paste stored in the storage tank 35 flows into the conduit 37 through the liquid inlet 38, and is then transported to the adsorption sponge 34 and adsorbed by it. When the adsorption sponge 34 adsorbs the UV-curable silver paste, the conical temperature probe 25 rotates past the adsorption sponge 34 and coats its contact end with the UV-curable silver paste. This UV-curable silver paste can tightly fill the tiny gaps at the contact interface between the probe and the resistor under test 2, reducing the obstruction of heat conduction by air gaps. Even if the probe contact area is small, it can ensure that the temperature signal of the resistor under test 2 is smoothly transmitted to the probe, avoiding excessive thermal resistance, temperature measurement delay, or deviation caused by small contact area.

[0043] Regardless of whether a conical temperature probe 25 or a circular temperature probe 26 is used for temperature measurement, the shield 3 will cover the entire resistor 2 under test throughout the entire process, forming a closed area for the detection and isolating the influence of airflow and radiant heat, thereby further improving the accuracy of temperature detection.

[0044] Furthermore, the adsorption sponge 34 is normally located away from the rotation path of the circular temperature probe 26. Therefore, when the circular temperature probe 26 rotates counterclockwise to replace the conical temperature probe 25, it will not come into contact with the adsorption sponge 34. Additionally, regardless of whether the conical temperature probe 25 or the circular temperature probe 26 is directly below the top magnetic block 19, they will extend downwards and out of the inner cylinder 15 under the action of repulsive magnetic force. When rotating away from this position, they will retract to their original position under the elastic force of the first spring 27 or the second spring 30. It should also be noted that this technical solution… In this case, after the UV-curable silver paste is applied to the contact end of the conical temperature probe 25 by the absorbent sponge 34, the ultraviolet light inside the substrate 1 (not shown in the figure) will irradiate upwards, achieving drying in seconds. At the same time, although the entire base plate 31 is on the counterclockwise rotation path of the two probes, only the scraper 32 and the absorbent sponge 34 will contact the contact ends of the two probes, and will not interfere with the rotation switching of the two probes. When the UV-curable silver paste in the storage tank 35 is used up, the flip door 6 and the flip opening can be opened one after the other to replenish the liquid through the liquid filling port on the storage tank 35.

[0045] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus.

[0046] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A temperature measuring device for thermistor, comprising a base plate (1) and a hand-held piece (4), characterized in that, The outer side wall of the substrate (1) is provided with a resistance to be measured (2), the end of the handheld piece (4) is fixedly connected with an inner cylinder (15), the inner side of the inner cylinder (15) is fixedly connected with a top magnetic block (19), the inner side of the inner cylinder (15) is provided with a probe switching mechanism, the probe switching mechanism comprises a rotating rod (18) which is rotatably connected in the inner cylinder (15), the outer side wall of the rotating rod (18) is fixedly connected with a gear (23), the inner cylinder (15) is slidably connected with a push rod (16), the end of the push rod (16) is provided with a rack (21), the rack (21) and the gear (23) are in meshing arrangement, the end of the rotating rod (18) is fixedly connected with a horizontal plate (24), the outer side wall of the horizontal plate (24) is fixedly connected with a protruding block (22), the two sides of the horizontal plate (24) are slidably connected with a conical temperature measuring probe (25) and a circular temperature measuring probe (26) respectively; The outer side wall of the conical temperature measuring probe (25) is sleeved with a first spring (27), the end of the conical temperature measuring probe (25) is fixedly connected with a first magnetic block (28), the magnetic pole of the first magnetic block (28) is the same as that of the top magnetic block (19), the outer side wall of the circular temperature measuring probe (26) is sleeved with a second spring (30), the end of the circular temperature measuring probe (26) is fixedly connected with a second magnetic block (29), the magnetic pole of the second magnetic block (29) is the same as that of the top magnetic block (19); The inner side of the inner cylinder (15) is fixedly connected with a bottom plate (31), the bottom plate (31) is fixedly connected with a scraper (32), and the bottom plate (31) is provided with a probe cleaning mechanism; The probe cleaning mechanism comprises a liquid storage tank (35) fixedly connected to the bottom plate (31), a sliding groove is formed in the side wall of the liquid storage tank (35), a pressing piece (20) is slidably connected in the sliding groove, a connecting column (39) is fixedly connected to the outer side wall of the pressing piece (20), a pressing plate (36) is fixedly connected to the end of the connecting column (39) away from the pressing piece (20), and a connecting rod (40) is rotatably connected to the side of the pressing piece (20) away from the connecting column (39); A sliding rail is formed in the bottom plate (31), an adsorption sponge (34) is slidably connected in the sliding rail, a pressure spring (33) is fixedly connected to the outer side wall of the adsorption sponge (34), the end of the pressure spring (33) away from the adsorption sponge (34) is in contact with the inner wall of the sliding rail, the outer wall of the adsorption sponge (34) is rotatably connected to the other end of the connecting rod (40), a conduit (37) is slidably connected in the liquid storage tank (35), a liquid inlet hole (38) is formed in the conduit (37), and the end of the conduit (37) away from the liquid inlet hole (38) is in communication with the adsorption sponge (34); A magnetic plate (14) is fixedly connected to the side wall of the push rod (16), the magnetic plate (14) slidably penetrates to the outside of the shielding cover (3), a pressing spring (17) is fixedly connected to the outer side wall of the push rod (16), and the other end of the pressing spring (17) is in contact with the inner cylinder (15).

2. The temperature measuring device for thermistor according to claim 1, characterized in that: The outer side wall of the hand-held piece (4) is fixedly connected with a shielding cover (3), the shielding cover (3) is rotationally connected with two groups of swing arms (5), the swing arms (5) are rotationally connected with cleaning pieces (7), and the cleaning pieces (7) are provided with resistance pretreatment mechanisms.

3. The temperature measuring device for thermistor according to claim 2, characterized in that: The resistance pretreatment mechanism comprises a cleaning brush (8) fixedly connected to the cleaning piece (7), a plurality of rollers (13) fixedly connected to the outer side wall of the cleaning piece (7), an inner groove (11) formed in one of the two cleaning pieces (7), a trigger magnetic block (12) slidably connected to the inner groove (11), two support frames (9) fixedly connected to the outer side wall of one of the two cleaning pieces (7), and an extension rod (10) fixedly connected to the trigger magnetic block (12) and away from the support frame (9).

4. The temperature measuring device for thermistor according to claim 2, characterized in that: The side wall of the shielding cover (3) is provided with a turnover door (6), and the inner cylinder (15) is provided with a turnover opening.

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