High-voltage reactive automatic compensation device

Abstract

The high-voltage reactive power automatic compensation device comprises an outer shell, a high-voltage reactive power automatic compensation unit is installed in the outer shell, and one side of the outer shell is connected with a heat dissipation and humidity regulation mechanism through a connection mechanism; the heat dissipation and humidity adjustment mechanism comprises a ventilation bin, an evaporator, a square frame and a condenser are sequentially installed in the ventilation bin from left to right, a capillary tube is connected between the evaporator and the condenser, a compressor is installed at the bottom end of the ventilation bin, and a plurality of transverse plates are arranged on the inner wall of the square frame at equal intervals. The high-voltage reactive automatic compensation device comprises a square frame, a plurality of transverse plates are arranged in the square frame, one side of the square frame and one side of each transverse plate are attached to one side of an evaporator, cooling fins are fixedly connected to the outer wall of the outer side of the square frame, and a flow guide mechanism is arranged at the bottom end of a ventilation bin. The internal temperature and humidity of the high-voltage reactive automatic compensation device are ensured to be normal, and the reliability of equipment is prevented from being reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of high - voltage reactive power automatic compensation devices, and particularly to a high - voltage reactive power automatic compensation device. Background Art

[0002] The high - voltage reactive power automatic compensation device is an important part of the power system. It can improve the utilization rate of equipment while meeting the requirements of the system for power quality. This device is usually applied to key places such as substations, and its main function is to accurately calculate the reactive power demand in the system according to the real - time monitored voltage and current data.

[0003] During the use process, abnormal temperature and humidity inside the high - voltage reactive power automatic compensation device will lead to problems such as reduced equipment performance, reduced reliability, and shortened service life. Generally, a heat - dissipation structure for regulating temperature is provided inside the high - voltage reactive power automatic compensation device, but a structure for regulating humidity is not provided. For high - voltage reactive power automatic compensation devices used outdoors and in high - humidity areas, abnormal humidity will directly lead to poor insulation and electric leakage, resulting in corrosion of the metal parts of the equipment. And due to the high voltage inside the high - voltage reactive power automatic compensation device, it may also lead to serious electric shock accidents. Summary of the Invention

[0004] The present invention discloses a high - voltage reactive power automatic compensation device, aiming to solve the technical problems that for high - voltage reactive power automatic compensation devices used outdoors and in high - humidity areas, abnormal humidity will directly lead to poor insulation and electric leakage, resulting in corrosion of the metal parts of the equipment. And due to the high voltage inside the high - voltage reactive power automatic compensation device, it may also lead to serious electric shock accidents.

[0005] To achieve the above object, the present invention adopts the following technical solutions: A high - voltage reactive power automatic compensation device includes a housing body. A high - voltage reactive power automatic compensation unit is installed inside the housing body, and one side of the housing body is connected with a heat - dissipation and humidity - regulation mechanism through a connection mechanism; The heat dissipation and humidity adjustment mechanism includes a ventilation chamber, in which an evaporator, a square frame and a condenser are sequentially installed from left to right. A capillary tube is connected between the evaporator and the condenser. A compressor is installed at the bottom end of the ventilation chamber. A plurality of cross plates are equidistantly arranged on the inner wall of the square frame, and one side of the square frame and the plurality of cross plates is attached to one side of the evaporator. Heat sinks are respectively fixedly connected to the outer side walls of the square frame. A temperature and humidity monitor is installed on one outer wall of the ventilation chamber, and a conical transition chamber is connected to the other inner wall of the ventilation chamber. A two-way guide fan is installed in the conical transition chamber, and one end of the conical transition chamber is connected to a second ventilation pipe through a connection mechanism. A plurality of heat dissipation fins are equidistantly arranged on the outer side of the second ventilation pipe, and the other end of the second ventilation pipe is connected to one inner wall of the outer casing through a connection mechanism. A diversion mechanism is arranged at the bottom end of the ventilation chamber.

[0006] A plurality of square notches are respectively penetrated through the inner walls on multiple sides of the ventilation chamber, and a plurality of heat sinks respectively pass through the square notches. The outer walls of the plurality of heat sinks are respectively connected to the inner walls of the square notches. A second filter screen is installed on one inner wall of the ventilation chamber, and the second filter screen is located inside the outer casing.

[0007] By providing the heat dissipation and humidity adjustment mechanism, during the operation of the high-voltage reactive power automatic compensation unit, the temperature and humidity inside the outer casing are monitored in real time through the temperature and humidity monitor, and the compressor and the two-way guide fan are controlled. When the monitored humidity is high, the two-way guide fan can be adjusted to exhaust air outwards, which can simultaneously achieve the effects of heat dissipation and dehumidification; if the monitored humidity is normal but the temperature is high, then control the two-way guide fan to draw air inwards, which can achieve the effect of efficient heat dissipation. Under this structure, heat dissipation and dehumidification can be synchronously achieved according to environmental changes, ensuring the normal temperature and humidity inside the high-voltage reactive power automatic compensation device and avoiding the reduction of equipment reliability.

[0008] In a preferred solution, the connection mechanism includes a limit sleeve and a first ventilation pipe, and the first ventilation pipe is fixedly connected to one inner wall of the outer casing. Card one is respectively fixedly connected to the outer walls of the same end of the conical transition chamber and the first ventilation pipe, and card two is fixedly connected to both ends of the second ventilation pipe.

[0009] The limit sleeve is simultaneously sleeved outside the corresponding card one and card two, and a circular through groove is penetrated through the central position of the limit sleeve. One end of the conical transition chamber, both ends of the second ventilation pipe, and one end of the first ventilation pipe can all pass through the circular through groove.

[0010] An extension groove is simultaneously penetrated through the limit sleeve, and the extension groove is located on both sides of the circular through groove. Card one and card two can both pass through the extension groove, and sealing sheets are attached to both ends of the second ventilation pipe.

[0011] A mounting bracket is fixedly connected to the middle section of the first ventilation pipe, and a slot is provided on the inner wall of the top end of the mounting bracket. A filter screen bracket is inserted into the slot, and a first filter screen is supported inside the filter screen bracket.

[0012] By providing a connection mechanism, the connection mechanism facilitates the disassembly of the second ventilation pipe. Thus, when the current ambient temperature and humidity are appropriate, the second ventilation pipe can be removed, and only the two-way guide fan is started to exhaust air outward. Then, air can enter through the first ventilation pipe and be exhausted by the two-way guide fan, enabling the internal air to circulate and ensuring normal heat dissipation. During this process, the compressor is not started, which can save costs.

[0013] In a preferred solution, the diversion mechanism includes a support housing, and the support housing is connected to the bottom end of the ventilation chamber. A partition is fixedly connected to both the inner wall of the bottom end of the support housing and the outer wall of the bottom end of the ventilation chamber. A plurality of through holes are provided through the bottom end of the support housing, and the plurality of through holes are located on one side of the partition, while the compressor is located on the other side of the partition.

[0014] A circular sleeve is respectively inserted into each of the through holes. A plurality of first through grooves are equidistantly provided through the circumferential wall of the circular sleeve, and a cotton strip is stuffed into the circular sleeve. A rubber sleeve is wrapped around the outer wall of the circular sleeve.

[0015] By providing a diversion mechanism, during the moisture absorption process, the moisture in the air condenses into water droplets after contacting the evaporator and then falls downward along the trend until it remains in the support housing. The remaining water can pass through the first through grooves to contact the cotton strip, and under the adsorption and guidance of the cotton strip, it is drained downward and discharged from the bottom end of the cotton strip. With this structure, while ensuring that there is no water residue inside the support housing, it can also prevent the intake of air from the through hole position during the ventilation process from affecting the air extraction effect inside the outer housing.

[0016] As can be seen from the above, a high-voltage reactive power automatic compensation device includes a housing body. Inside the housing body, a high-voltage reactive power automatic compensation unit is installed, and one side of the housing body is connected to a heat dissipation and humidity regulation mechanism through a connection mechanism; the heat dissipation and humidity regulation mechanism includes a ventilation chamber, and a diversion mechanism is arranged at the bottom end of the ventilation chamber. Inside the ventilation chamber, an evaporator, a square frame, and a condenser are installed in sequence from left to right. A capillary tube is connected between the evaporator and the condenser. A compressor is installed at the bottom end of the ventilation chamber. A plurality of horizontal plates are equidistantly arranged on the inner wall of the square frame, and one side of the square frame and the plurality of horizontal plates is attached to one side of the evaporator. Heat dissipation fins are respectively fixedly connected to the outer side wall of the square frame. A temperature and humidity monitor is installed on one outer wall of the ventilation chamber, and a conical transition chamber is connected to the other inner wall of the ventilation chamber. A two-way guide fan is installed in the conical transition chamber, and one end of the conical transition chamber is connected to the inner wall of one side of the housing body through a connection mechanism by a second ventilation pipe. A plurality of heat dissipation fins are equidistantly arranged on the outer side of the second ventilation pipe, and the other end of the second ventilation pipe is connected to the inner wall of one side of the housing body through a connection mechanism. A diversion mechanism is arranged at the bottom end of the ventilation chamber. The high-voltage reactive power automatic compensation device provided by the present invention has the technical effect of being able to synchronously achieve heat dissipation and dehumidification according to environmental changes, ensuring the normal temperature and humidity inside the high-voltage reactive power automatic compensation device, and avoiding the reduction of equipment reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 FIG. is a schematic diagram of the overall external structure of the high-voltage reactive power automatic compensation device proposed by the present invention.

[0018] Figure 2 FIG. is a schematic diagram of the internal structure of the high-voltage reactive power automatic compensation device proposed by the present invention.

[0019] Figure 3 FIG. is a schematic diagram of the disassembled heat dissipation and humidity regulation structure of the high-voltage reactive power automatic compensation device proposed by the present invention.

[0020] Figure 4 FIG. is a schematic diagram of a partial structure of the diversion mechanism of the high-voltage reactive power automatic compensation device proposed by the present invention.

[0021] Figure 5 FIG. is a schematic diagram of the disassembled connection mechanism of the high-voltage reactive power automatic compensation device proposed by the present invention.

[0022] In the figure: 1. Outer shell; 2. Connecting mechanism; 3. Heat dissipation and humidity regulation mechanism; 4. Flow guiding mechanism; 201. Card 1; 202. Limiting sleeve; 203. Extension groove; 204. Circular through groove; 205. Card 2; 206. Mounting frame; 207. Slot; 208. Vent pipe 1; 209. Filter screen support; 210. Filter screen 1; 301. Filter screen 2; 302. Ventilation chamber; 303. Heat dissipation fins; 304. Vent pipe 2; 305. Square notch; 306. Conical transition chamber; 307. Bidirectional guide fan; 308. Compressor; 309. Condenser; 310. Capillary tube; 311. Evaporator; 312. Heat sink; 313. Horizontal plate; 314. Square frame; 315. Temperature and humidity monitor; 401. Partition board; 402. Circular sleeve; 403. Support shell; 404. Rubber sleeve; 405. Through groove 1; 406. Cotton strip. Detailed implementation mode

[0023] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments.

[0024] A high-voltage reactive power automatic compensation device disclosed by the present invention is mainly applied to the scenarios where high-voltage reactive power automatic compensation devices are used.

[0025] Refer to Figures 1-3 , a high-voltage reactive power automatic compensation device, including an outer shell 1, a high-voltage reactive power automatic compensation unit is installed inside the outer shell 1, and a heat dissipation and humidity regulation mechanism 3 is connected to one side of the outer shell 1 through a connecting mechanism 2.

[0026] Among them, the heat dissipation and humidity regulation mechanism 3 includes a ventilation chamber 302. An evaporator 311, a square frame 314, and a condenser 309 are installed in the ventilation chamber 302 in sequence from left to right. A capillary tube 310 is connected between the evaporator 311 and the condenser 309. A compressor 308 is installed at the bottom end of the ventilation chamber 302. A plurality of horizontal plates 313 are equidistantly arranged on the inner wall of the square frame 314, and one side of the square frame 314 and the plurality of horizontal plates 313 is attached to one side of the evaporator 311; heat sinks 312 are respectively fixedly connected to the outer side wall of the square frame 314. A temperature and humidity monitor 315 is installed on one side outer wall of the ventilation chamber 302, and a conical transition chamber 306 is connected to the other inner wall of the ventilation chamber 302. A bidirectional guide fan 307 is installed in the conical transition chamber 306, and one end of the conical transition chamber 306 is connected to a vent pipe 2 304 through a connecting mechanism 2. A plurality of heat dissipation fins 303 are equidistantly arranged on the outer side of the vent pipe 2 304, and the other end of the vent pipe 2 304 is connected to one side inner wall of the outer shell 1 through a connecting mechanism 2.

[0027] During the operation of the high-voltage reactive power automatic compensation unit, the temperature and humidity monitor 315 monitors the temperature and humidity inside the outer casing 1 in real time, and controls the compressor 308 and the two-way guide fan 307. When the monitored humidity is high, the two-way guide fan 307 can be adjusted to exhaust air outward. The air contacts the evaporator 311 and condenses into water droplets on the surface of the evaporator 311, and then is heated by the condenser 309 and returns to the inside of the outer casing 1 again through the second ventilation pipe 304. When passing through the second ventilation pipe 304, it is cooled by multiple heat dissipation fins 303. When entering the inside of the outer casing 1, it can achieve a heat dissipation effect synchronously. And because the entire outer casing 1 is a relatively sealed space and the air circulation is controlled inside, it can prevent the continuous entry of external air from affecting the internal humidity change; if the monitored humidity is normal but the temperature is high, then control the two-way guide fan 307 to draw air inward. The gas inside the outer casing 1 enters the ventilation chamber 302 through the second ventilation pipe 304, heats up when passing through the condenser 309, and cools down when passing through multiple cross plates 313 under the condition of multiple heat dissipation fins 312 and the cross plates 313 being driven to cool down by contacting the evaporator 311, and further cools down when passing through the cross plates 313, so that cold air can continuously enter the outer casing 1 to achieve an efficient heat dissipation effect. Under this structure, heat dissipation and dehumidification can be achieved synchronously according to environmental changes, ensuring the normal temperature and humidity inside the high-voltage reactive power compensation device and preventing the reduction of equipment reliability.

[0028] Refer to Figure 3 In a preferred embodiment, a plurality of square notches 305 are respectively penetrated through the inner walls on multiple sides of the ventilation chamber 302, and a plurality of heat dissipation fins 312 respectively pass through the square notches 305, and the outer walls of the plurality of heat dissipation fins 312 are respectively connected to the inner walls of the square notches 305. A second filter screen 301 is installed on one inner wall of the ventilation chamber 302, and the second filter screen 301 is located inside the outer casing 1.

[0029] Refer to Figure 5 In a preferred embodiment, the connection mechanism 2 includes a limit sleeve 202 and a first ventilation pipe 208, and the first ventilation pipe 208 is fixedly connected to one inner wall of the outer casing 1. A first card 201 is respectively fixedly connected to the outer walls of the same ends of the conical transition chamber 306 and the first ventilation pipe 208, and a second card 205 is respectively fixedly connected to both ends of the second ventilation pipe 304.

[0030] Refer to Figure 5 In a preferred embodiment, the limit sleeve 202 is simultaneously sleeved outside the corresponding first card 201 and second card 205, and a circular through groove 204 is penetrated through the central position of the limit sleeve 202. One end of the conical transition chamber 306, both ends of the second ventilation pipe 304, and one end of the first ventilation pipe 208 can all pass through the circular through groove 204.

[0031] Refer to Figure 5, in a preferred embodiment, an extension groove 203 is simultaneously formed through the limiting sleeve 202, and the extension groove 203 is located on both sides of the circular through groove 204. Both the first card 201 and the second card 205 can pass through the extension groove 203, and sealing sheets are attached to both ends of the second ventilation pipe 304.

[0032] Refer to Figure 5 , in a preferred embodiment, a mounting bracket 206 is fixedly connected to the middle section of the first ventilation pipe 208, and a slot 207 is provided on the inner wall of the top end of the mounting bracket 206. A filter screen bracket 209 is inserted into the slot 207, and a first filter screen 210 is supported inside the filter screen bracket 209; in the connection mechanism 2, the first card 201 and the second card 205 enter the limiting sleeve 202 from the extension groove 203, the sealing sheet is attached to one end of the conical transition chamber 306 and the first ventilation pipe 208, and then the limiting sleeve 202 is rotated, so that the conical transition chamber 306 and the first ventilation pipe 208 can be respectively connected to the second ventilation pipe 304. The installation is simple and the disassembly of the second ventilation pipe 304 is convenient; thus, if the current environmental temperature and humidity are appropriate, the second ventilation pipe 304 can be removed, and only the two-way guide fan 307 is started to exhaust air outward, so that air can enter from the first ventilation pipe 208 and the two-way guide fan 307 can exhaust air, enabling the internal air to circulate and ensuring normal heat dissipation. During this process, the compressor 308 is not started, which can save costs. Under the action of the first filter screen 210, the air inlet can be filtered to prevent dust from entering, and the first filter screen 210 is connected by insertion, which also facilitates the cleaning of the first filter screen 210.

[0033] Refer to Figure 3 and Figure 4 , in a preferred embodiment, a diversion mechanism 4 is provided at the bottom end of the ventilation chamber 302; the diversion mechanism 4 includes a support housing 403, and the support housing 403 is connected to the bottom end of the ventilation chamber 302. A partition 401 is fixedly connected to both the inner wall of the bottom end of the support housing 403 and the outer wall of the bottom end of the ventilation chamber 302. A plurality of through holes are formed through the bottom end of the support housing 403, and the plurality of through holes are located on one side of the partition 401, and the compressor 308 is located on the other side of the partition 401.

[0034] Refer to Figure 4, in a preferred embodiment, a circular sleeve 402 is inserted into each perforation respectively. A plurality of first through slots 405 are equidistantly and penetratingly arranged on the circumferential wall of the circular sleeve 402. A cotton strip 406 is stuffed into the circular sleeve 402, and a rubber sleeve 404 is wrapped around the outer wall of the circular sleeve 402. During the moisture absorption process, the moisture in the air contacts the evaporator 311 and condenses into water droplets, which then fall down along the trend. Until it remains in the support housing 403, and a partition 401 is established to prevent contact with the compressor 308. The remaining water can pass through the first through slots 405 to contact the cotton strip 406, and under the adsorption and guidance of the cotton strip 406, it is drained downward and discharged from the bottom end of the cotton strip 406. In this structure, while ensuring that there is no water residue inside the support housing 403, it can also prevent the intake of air from the perforation position during ventilation from affecting the air extraction effect inside the outer housing 1.

[0035] Working principle: During the operation of the high-voltage reactive power automatic compensation unit, the temperature and humidity inside the outer housing 1 are monitored in real time through the temperature and humidity monitor 315, and the compressor 308 and the two-way guide fan 307 are controlled. When the monitored humidity is high, the two-way guide fan 307 can be adjusted to extract air outward. The air contacts the evaporator 311 and condenses into water droplets on the surface of the evaporator 311, and then is heated by the condenser 309 and returns to the inside of the outer housing 1 again through the second ventilation pipe 304. When passing through the second ventilation pipe 304, it is cooled by a plurality of heat dissipation fins 303. When entering the inside of the outer housing 1, it can achieve a heat dissipation effect synchronously. And since the entire outer housing 1 is a relatively sealed space and the air circulation is controlled inside, it can prevent the continuous entry of external air from affecting the internal humidity change. If the monitored humidity is normal but the temperature is high, then the two-way guide fan 307 is controlled to extract air inward. The gas inside the outer housing 1 enters the ventilation chamber 302 through the second ventilation pipe 304, is heated when passing through the condenser 309, and is cooled when passing through a plurality of cross plates 313 under the condition of being cooled by a plurality of heat dissipation fins 312 and the cross plates 313 being driven to cool by contacting the evaporator 311. When passing through the cross plates 313, it is further cooled, so that cold air can continuously enter the outer housing 1 to achieve an efficient heat dissipation effect. In this structure, heat dissipation and dehumidification can be achieved synchronously according to environmental changes, ensuring the normal temperature and humidity inside the high-voltage reactive power automatic compensation device and preventing the reduction of equipment reliability.

[0036] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution of the present invention and its inventive concept, makes equivalent substitutions or changes, and should be covered by the protection scope of the present invention.

Claims

1. A high-voltage reactive power automatic compensation device, comprising an outer shell (1), characterized in that: A high-voltage reactive power automatic compensation unit is installed inside the outer shell (1), and a heat dissipation and humidity regulating mechanism (3) is connected to one side of the outer shell (1) via a connecting mechanism (2); The heat dissipation and humidity control mechanism (3) comprises a ventilation chamber (302), wherein an evaporator (311), a square frame (314) and a condenser (309) are sequentially installed in the ventilation chamber (302) from left to right, and a capillary tube (310) is connected between the evaporator (311) and the condenser (309), a compressor (308) is installed at the bottom end of the ventilation chamber (302), a plurality of transverse plates (313) are equidistantly arranged on the inner wall of the square frame (314), and one side of the square frame (314) and the plurality of transverse plates (313) are attached to one side of the evaporator (311), and the outer wall of the square frame (314) is respectively fixedly connected with heat sinks ( 312), a temperature and humidity monitor (315) is installed on the outer wall of one side of the ventilation bin (302), and the inner wall of the other side of the ventilation bin (302) is connected to a conical transition bin (306), a two-way guide fan (307) is installed in the conical transition bin (306), and one end of the conical transition bin (306) is connected to a second ventilation pipe (304) through a connecting mechanism (2), a plurality of heat dissipation fins (303) are equidistantly arranged on the outer side of the second ventilation pipe (304), and the other end of the second ventilation pipe (304) is connected to the inner wall of one side of the outer shell (1) through a connecting mechanism (2), and a flow guide mechanism (4) is arranged at the bottom end of the ventilation bin (302).

2. A high-voltage reactive power automatic compensation device according to claim 1, characterized in that: Multiple square slots (305) are respectively provided through the inner walls on multiple sides of the ventilation bin (302), and multiple heat sinks (312) pass through the square slots (305), respectively; the outer walls of the multiple heat sinks (312) are respectively connected to the inner walls of the square slots (305), and a second filter (301) is installed on the inner wall of one side of the ventilation bin (302), and the second filter (301) is located inside the outer shell (1).

3. A high-voltage reactive power automatic compensation device according to claim 1, characterized in that: The connection mechanism (2) comprises a limiting sleeve (202) and a ventilation pipe (208), and the ventilation pipe (208) is fixedly connected to an inner wall of one side of the outer shell (1), and the outer walls of the same ends of the conical transition bin (306) and the ventilation pipe (208) are respectively fixedly connected to a card (201), and the two ends of the ventilation pipe (304) are respectively fixedly connected to a card (205).

4. A high-voltage reactive power automatic compensation device according to claim 3, characterized in that: The limiting sleeve (202) is simultaneously sleeved on the outside of card one (201) and card two (205) at corresponding positions, and a circular through groove (204) is provided at the center position of the limiting sleeve (202), and one end of the conical transition bin (306), both ends of the ventilation pipe two (304), and one end of the ventilation pipe one (208) can all pass through the circular through groove (204).

5. A high-voltage reactive power automatic compensation device according to claim 4, characterized in that: The limiting sleeve (202) is also provided with an extension groove (203) penetrating therethrough, and the extension groove (203) is located on both sides of the circular through groove (204), and both the card 1 (201) and the card 2 (205) can pass through the extension groove (203), and sealing sheets are attached to both ends of the ventilation pipe 2 (304).

6. A high-voltage reactive power automatic compensation device according to claim 5, characterized in that: The middle section of the ventilation pipe one (208) is fixedly connected to a mounting frame (206), and a slot (207) is provided on the inner wall of the top end of the mounting frame (206). A filter screen bracket (209) is inserted into the slot (207), and a filter screen one (210) is supported in the filter screen bracket (209).

7. A high-voltage reactive power automatic compensation device according to claim 1, characterized in that: The flow guide mechanism (4) comprises a support shell (403), and the support shell (403) is connected to the bottom end of the ventilation bin (302), the bottom inner wall of the support shell (403) and the bottom outer wall of the ventilation bin (302) are fixedly connected with a partition (401), and a plurality of through holes are provided through the bottom end of the support shell (403), the plurality of through holes are located on one side of the partition (401), and the compressor (308) is located on the other side of the partition (401).

8. A high-voltage reactive power automatic compensation device according to claim 7, characterized in that: A circular sleeve (402) is inserted into each of the through holes, a plurality of through grooves (405) are evenly spaced through the circumferential wall of the circular sleeve (402), a cotton strip (406) is inserted into the circular sleeve (402), and the outer wall of the circular sleeve (402) is wrapped with a rubber sleeve (404).

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