Printer shaft with heat dissipation structure

Abstract

The invention relates to the technical field of printer shafts, in particular to a printer shaft with a heat dissipation structure, which comprises a shaft body, connecting columns are fixed at two ends of the shaft body, a ventilation mechanism is arranged in the shaft body, cooling mechanisms are mounted at two ends of the ventilation mechanism, and blowing mechanisms are mounted on the outer sides of the cooling mechanisms. The printer shaft cooling device has the beneficial effects that the heat dissipation and cooling speed of the printer shaft can be increased, and the temperature of the printer shaft is greatly reduced and continuously kept; in the cooling mechanism, a liquid inlet pipe, a liquid outlet pipe, a booster pump, a cooling liquid tank and a miniature water cooler are combined and connected to form a cooling liquid recycling closed loop, the shaft body can be directly cooled through a cooling cylinder, and blown air is cooled through an air cooling pipe to indirectly cool the shaft body; the cooling range and amplitude of the shaft body are large, and the heat dissipation effect of the printer shaft is good.

Description

Technical Field

[0001] The present invention relates to the technical field of printer shafts, and in particular to a printer shaft with a heat dissipation structure. Background Art

[0002] A printer is one of the output devices of a computer. There are three indicators to measure the quality of a printer: print resolution, print speed and noise. There are many types of printers. According to whether the printing element hits the paper, they are divided into impact printers and non-impact printers. According to the structure of printed characters, they are divided into full-width character printers and dot matrix character printers. According to the way a line of characters is formed on paper, they are divided into serial printers and line printers. The printer shaft is mainly used to connect the nozzle part so that the nozzle part can slide on the shaft.

[0003] Printers are mainly used to print computer processing results on related media. They can be divided into laser printers, inkjet printers, impact printers and other types. According to the technology used, they are divided into cylindrical, spherical, inkjet, thermal, laser, electrostatic, magnetic, light-emitting diode and other printers. Printers are devices that print computer calculation results or intermediate results on paper in the form of numbers, letters, symbols and graphics that can be recognized by humans in a prescribed format. Printers are developing towards light, thin, short, small, low power consumption, high speed and intelligence.

[0004] At present, when a printer works for a long time, the printer shaft is easily overheated. Therefore, a printer shaft with a heat dissipation structure is proposed.

[0005] For example, the prior art Chinese patent publication number "CN212267033U" provides a printer shaft with heat dissipation function, including a shell, an outer wall of the shell is provided with a heat dissipation mechanism, an outer surface of one side of the shell is provided with a shaft core and a lubrication mechanism, and the shaft core is located on one side of the lubrication mechanism.

[0006] The device is connected by fixing bolts through the heat dissipation mechanism on one side of the printer shaft housing. The copper core in the heat dissipation mechanism can absorb heat, and the heat absorption sleeve can dissipate the heat through the heat dissipation holes. The copper core and the heat absorption sleeve are connected by expansion bolts to prevent excessive temperature from affecting the printing quality and preventing temperature from damaging components. Further, through the lubrication mechanism on one side of the shaft core, the lubricating oil can be transferred to the shaft core through the lubricating oil groove to prevent long-term work from causing internal drying and affecting work. The anti-slip coating can prevent falling off after high-speed rotation, bringing better use prospects.

[0007] The existing printer shaft with a heat dissipation structure, when in use, only achieves the purpose of heat dissipation by blowing air on the surface or inside of the printer shaft. However, the heat dissipation of the printer shaft is slow, the temperature reduction range is small, and the temperature of the printer shaft surface cannot be quickly reduced and maintained, which affects the quality of subsequent printing. Summary of the invention

[0008] The purpose of the present invention is to solve the shortcomings of the prior art that the printer shaft dissipates heat slowly, the temperature reduction is small, the temperature of the printer shaft surface cannot be quickly reduced and maintained, and the quality of subsequent printing is affected. A printer shaft with a heat dissipation structure is proposed.

[0009] To achieve the above object, the present invention provides the following technical solutions: A printer shaft with a heat dissipation structure is designed, comprising a shaft body, connecting columns are fixed at both ends of the shaft body, a ventilation mechanism is arranged inside the shaft body, cooling mechanisms are installed at both ends of the ventilation mechanism, and a blower mechanism is installed outside the cooling mechanism; the ventilation mechanism comprises air guide holes and heat dissipation holes, the air guide holes are evenly arranged on the inner edge of the shaft body along the axial direction of the shaft body, the heat dissipation holes are evenly distributed on the surface of the shaft body and are connected with the air guide holes, and are used for ventilating and dissipating the heat inside the printer shaft; the cooling mechanism comprises a cooling cylinder, an air cooling pipe and a coolant circulation mechanism, the cooling cylinder is slidably sleeved on the surface of the connecting column, a silicone pad bonded to the outer end of the shaft is arranged on the inner side of the cooling cylinder, a connecting hole is opened on the surface of the silicone pad, and the cooling cylinder is provided with a cooling liquid circulation mechanism. The air cooling pipe runs through both ends of the cooling cylinder, and its inner end is connected to the connecting hole and the air guide hole, and the coolant circulation mechanism is connected to both sides of the cooling cylinder; the coolant circulation mechanism includes an inlet pipe, an outlet pipe, a coolant tank and a micro-water chiller, the top end of the inlet pipe is connected to one side of the cooling cylinder, and the bottom end is connected to the micro-water chiller, and the other side of the micro-water chiller is connected to one side of the coolant tank through a pipeline, the top end of the outlet pipe is connected to the other side of the cooling cylinder, and the bottom end is connected to a booster pump, and the other side of the booster pump is connected to the other side of the coolant tank through a pipeline; the air blowing mechanism includes a blower, an air guide cylinder and a filter cover, and is slidably sleeved on the surface of the connecting column for blowing air to dissipate heat for the printer shaft. Furthermore, the air guide tube is slidably sleeved on the surface of the connecting column, and a first blowing pipe is connected to the inner side thereof, and the outer end of the first blowing pipe is slidably inserted into the interior of the air cooling tube, and a second blowing pipe is connected to the outer side of the air guide tube, and the second blowing pipe is evenly distributed on the outer surface of the cooling tube and in contact with the cooling tube, and the filter cover is installed inside the air guide tube, and dust filtering holes are evenly opened on the surface thereof, a blower is connected to the side of the blower, and the blower pipe is inserted into the interior of the filter cover, and a blocking cover is threadedly connected to the outer side of the air guide tube, and the inner side of the blocking cover abuts against the rear end of the filter cover. Furthermore, the connecting column is a cylindrical structure, the air guide hole is horizontally arranged and connected to the connecting hole, the cooling cylinder is a cylindrical structure, and the air cooling pipe is a cylindrical structure and is horizontally arranged. Furthermore, the liquid inlet pipe and the liquid outlet pipe are both C-shaped structures and are both arranged, and the booster pump, the coolant tank and the micro chiller are all installed below the cooling cylinder. Furthermore, the air guide tube is a cylindrical structure, and the inner side thereof abuts against the outer side of the cooling tube, and the first blowing pipe is a cylindrical structure, and is horizontally arranged. Furthermore, the second blowing pipe is of L-shaped structure and is horizontally arranged, with its air outlet facing the surface of the shaft body, and the second blowing pipe and the first blowing pipe are both connected to the interior of the air guide tube.

[0010] Furthermore, the filter cover is a cylindrical structure, and a gap is set between the outer surface and the inner surface of the air guide tube, and the air inlets of the first blowing pipe and the second blowing pipe are both located on the outside of the filter cover. Furthermore, the blast pipe passes through the air guide tube, the blocking cover is a circular structure, and the side surface is an external thread structure, the rear end inner surface of the air guide tube is an internal thread structure, and is threadedly connected with the blocking cover.

[0011] The printer shaft with a heat dissipation structure proposed by the present invention has the following beneficial effects: 1. The present invention respectively opens air guide holes and heat dissipation holes inside and on the surface of the shaft body, and dissipates heat by blowing air through blower mechanisms arranged at both ends of the shaft body, and removes dust by filtering through a filter cover to keep clean air blowing toward the shaft body, and a cooling mechanism is installed between the blower mechanism and the outer end of the shaft body. Therefore, the surface of the shaft body can be directly cooled by the cooling mechanism, and the cooling mechanism cools the air blown out by the blower mechanism and then blows it toward the shaft body to indirectly cool the printer shaft. Therefore, the heat dissipation cooling speed of the printer shaft can be improved, so as to significantly reduce the temperature of the printer shaft and maintain it continuously.

[0012] 2. In the cooling mechanism of the present invention, a liquid inlet pipe, a liquid outlet pipe, a booster pump, a coolant tank and a micro chiller are arranged to form a closed loop for circulating the coolant. The shaft body can be directly cooled by a cooling cylinder, and the shaft body can be indirectly cooled by cooling the blown air through an air cooling pipe, so that the cooling range and amplitude of the shaft body are large, and the heat dissipation effect of the printer shaft is good. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a schematic diagram of the overall structure of the present invention; Figure 2 For the present invention Figure 1 A magnified image of point A; Figure 3 For the present invention Figure 1 Schematic diagram of ventilation mechanism; Figure 4 For the present invention Figure 1 Schematic diagram of a hair dryer; Figure 5 For the present invention Figure 1 Schematic diagram of a hair dryer; Figure 6 For the present invention Figure 1 Schematic diagram of the filter cover part; Figure 7 For the present invention Figure 1 Schematic diagram of cooling mechanism; Figure 8 For the present invention Figure 1 Schematic diagram of the cooling mechanism.

[0014] In the figure: 1. shaft; 2. heat dissipation hole; 3. cooling cylinder; 4. second blowing pipe; 5. air guide cylinder; 6. baffle; 7. connecting column; 8. coolant tank; 9. booster pump; 10. blower; 11. blower pipe; 12. liquid outlet pipe; 13. silicone pad; 14. air guide hole; 15. filter cover; 16. first blowing pipe; 17. dust filter hole; 18. connecting hole; 19. air cooling pipe; 20. micro chiller; 21. liquid inlet pipe. DETAILED DESCRIPTION The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0015] Example 1 See also Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 , Figure 7 and Figure 8 A printer shaft with a heat dissipation structure shown in the figure includes a shaft body 1, connecting columns 7 are fixed at both ends of the shaft body 1, a ventilation mechanism is arranged inside the shaft body 1, cooling mechanisms are installed at both ends of the ventilation mechanism, and a blowing mechanism is installed outside the cooling mechanism.

[0016] The ventilation mechanism includes air guide holes 14 and heat dissipation holes 2. The air guide holes 14 are evenly arranged on the inner edge of the shaft body 1 along the axial direction of the shaft body 1. The heat dissipation holes 2 are evenly distributed on the surface of the shaft body 1 and connected to the air guide holes 14, so as to ventilate and dissipate heat inside the printer shaft.

[0017] The cooling mechanism includes a cooling cylinder 3, an air cooling pipe 19 and a coolant circulation mechanism. The cooling cylinder 3 is slidably sleeved on the surface of the connecting column 7, and a silicone pad 13 bonded to the outer end of the shaft body 1 is provided on the inner side thereof. A connecting hole 18 is opened on the surface of the silicone pad 13. The air cooling pipe 19 passes through both ends of the cooling cylinder 3, and the inner end thereof is connected to the connecting hole 18 and the air guide hole 14. The coolant circulation mechanism is connected to both sides of the cooling cylinder 3.

[0018] The coolant circulation mechanism includes an inlet pipe 21, an outlet pipe 12, a coolant tank 8 and a micro chiller 20. The model of the micro chiller 20 is HS1500-LAS1-001A. The top end of the inlet pipe 21 is connected to one side of the cooling cylinder 3, and the bottom end thereof is connected to the micro chiller 20. The other side of the micro chiller 20 is connected to one side of the coolant tank 8 through a pipeline. The top end of the outlet pipe 12 is connected to the other side of the cooling cylinder 3, and the bottom end thereof is connected to a booster pump 9. The other side of the booster pump 9 is connected to the other side of the coolant tank 8 through a pipeline.

[0019] The blower mechanism includes a blower 10, an air guide tube 5 and a filter cover 15, and is slidably sleeved on the surface of the connecting column 7 to blow air to dissipate heat from the printer shaft. An air guide hole 14 and a heat dissipation hole 2 are respectively provided inside and on the surface of the shaft body 1, and air is blown and dissipated through a blower mechanism provided at both ends of the shaft body 1, and dust is filtered and removed through a filter cover 15 to keep clean air blowing toward the shaft body 1, and a cooling mechanism is installed between the blower mechanism and the outer end of the shaft body 1, so that the surface of the shaft body 1 can be directly cooled by the cooling mechanism, and the cooling mechanism cools the air blown out by the blower mechanism and then blows it toward the shaft body 1 to indirectly cool the shaft body 1, thereby increasing the heat dissipation cooling speed of the printer shaft, achieving the goal of significantly reducing the temperature of the printer shaft and maintaining it continuously.

[0020] The connecting column 7 is a cylindrical structure, the air guide hole 14 is horizontally arranged and connected to the connecting hole 18, the cooling cylinder 3 is a cylindrical structure, and the air cooling pipe 19 is a cylindrical structure and is horizontally arranged. The liquid inlet pipe 21 and the liquid outlet pipe 12 are both C-shaped structures and are both arranged. The booster pump 9 , the coolant tank 8 and the micro chiller 20 are all installed below the cooling cylinder 3 . Example 2 See also Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 , Figure 7 and Figure 8 A printer shaft with a heat dissipation structure shown in the figure includes a shaft body 1, connecting columns 7 are fixed at both ends of the shaft body 1, a ventilation mechanism is arranged inside the shaft body 1, cooling mechanisms are installed at both ends of the ventilation mechanism, and a blowing mechanism is installed outside the cooling mechanism.

[0021] The ventilation mechanism includes air guide holes 14 and heat dissipation holes 2. The air guide holes 14 are evenly arranged on the inner edge of the shaft body 1 along the axial direction of the shaft body 1. The heat dissipation holes 2 are evenly distributed on the surface of the shaft body 1 and connected to the air guide holes 14, so as to ventilate and dissipate heat inside the printer shaft.

[0022] The cooling mechanism includes a cooling cylinder 3, an air cooling pipe 19 and a coolant circulation mechanism. The cooling cylinder 3 is slidably sleeved on the surface of the connecting column 7, and a silicone pad 13 bonded to the outer end of the shaft body 1 is provided on the inner side thereof. A connecting hole 18 is opened on the surface of the silicone pad 13. The air cooling pipe 19 passes through both ends of the cooling cylinder 3, and the inner end thereof is connected to the connecting hole 18 and the air guide hole 14. The coolant circulation mechanism is connected to both sides of the cooling cylinder 3.

[0023] The coolant circulation mechanism includes an inlet pipe 21, an outlet pipe 12, a coolant tank 8 and a micro chiller 20. The model of the micro chiller 20 is HS1500-LAS1-001A. The top end of the inlet pipe 21 is connected to one side of the cooling cylinder 3, and the bottom end thereof is connected to the micro chiller 20. The other side of the micro chiller 20 is connected to one side of the coolant tank 8 through a pipeline. The top end of the outlet pipe 12 is connected to the other side of the cooling cylinder 3, and the bottom end thereof is connected to a booster pump 9. The other side of the booster pump 9 is connected to the other side of the coolant tank 8 through a pipeline.

[0024] An air guide hole 14 and a heat dissipation hole 2 are respectively provided inside and on the surface of the shaft body 1, and air is blown and dissipated through a blower mechanism provided at both ends of the shaft body 1, and dust is filtered and removed through a filter cover 15 to keep clean air blowing toward the shaft body 1, and a cooling mechanism is installed between the blower mechanism and the outer end of the shaft body 1, so that the surface of the shaft body 1 can be directly cooled by the cooling mechanism, and the cooling mechanism cools the air blown out by the blower mechanism and then blows it toward the shaft body 1 to indirectly cool the shaft body 1, thereby increasing the heat dissipation cooling speed of the printer shaft, achieving the goal of significantly reducing the temperature of the printer shaft and maintaining it continuously.

[0025] The blowing mechanism includes a blower 10, an air guide tube 5 and a filter cover 15, and is slidably sleeved on the surface of the connecting column 7, and is used for blowing air to dissipate heat for the printer shaft; the air guide tube 5 is slidably sleeved on the surface of the connecting column 7, and is connected to a first blowing pipe 16 on its inner side, and the outer end of the first blowing pipe 16 is slidably inserted into the interior of the air cooling tube 19, and the outer side of the air guide tube 5 is connected to a second blowing pipe 4, and the second blowing pipe 4 is evenly distributed on the outer surface of the cooling tube 3 and is in contact with the cooling tube 3.

[0026] The filter cover 15 is installed inside the air guide tube 5, and dust filtering holes 17 are evenly opened on its surface. The side of the blower 10 is connected to a blower pipe 11, and the blower pipe 11 is inserted into the inside of the filter cover 15. The outer side of the air guide tube 5 is threadedly connected to a blocking cover 6, and the inner side of the blocking cover 6 abuts against the rear end of the filter cover 15. In the cooling mechanism, by arranging a liquid inlet pipe 21, a liquid outlet pipe 12, a booster pump 9, a coolant tank 8 and a micro chiller 20 to form a closed loop for circulating the coolant, the shaft body 1 can be directly cooled by the cooling cylinder 3, and the blown air can be cooled by the air cooling pipe 19 to indirectly cool the shaft body 1, so that the cooling range and amplitude of the shaft body 1 are large, and the heat dissipation effect of the printer shaft is good.

[0027] The air guide tube 5 is a cylindrical structure, and the inner side thereof abuts against the outer side of the cooling tube 3 . The first blowing pipe 16 is a cylindrical structure, and is horizontally arranged. The second blowing pipe 4 is of an L-shaped structure and is disposed horizontally, with its air outlet facing the surface of the shaft body 1 . The second blowing pipe 4 and the first blowing pipe 16 are both connected to the interior of the air guide tube 5 .

[0028] The filter cover 15 is a cylindrical structure, and a gap is set between the outer surface and the inner surface of the air guide tube 5 . The air inlets of the first blowing pipe 16 and the second blowing pipe 4 are both located on the outside of the filter cover 15 . The blast pipe 11 passes through the air guide tube 5 . The blocking cover 6 is a circular structure with an external thread structure on the side. The inner surface of the rear end of the air guide tube 5 is an internal thread structure and is threadedly connected with the blocking cover 6 .

[0029] Working method: air guide holes 14 and heat dissipation holes 2 are respectively provided inside and on the surface of the shaft body 1, and air is blown and dissipated through the air blower mechanisms arranged at both ends of the shaft body 1, and dust is filtered and removed through the filter cover 15 to keep clean air blowing toward the shaft body 1, and a cooling mechanism is installed between the air blower mechanism and the outer end of the shaft body 1, so that the surface of the shaft body 1 can be directly cooled by the cooling mechanism, and the cooling mechanism cools the air blown out by the air blower mechanism and then blows it toward the shaft body 1 to indirectly cool the shaft body 1, therefore, the heat dissipation cooling speed of the printer shaft can be increased, so as to significantly reduce the temperature of the printer shaft and maintain it continuously.

[0030] In the cooling mechanism, by arranging a liquid inlet pipe 21, a liquid outlet pipe 12, a booster pump 9, a coolant tank 8 and a micro chiller 20 to form a closed loop for circulating the coolant, the shaft body 1 can be directly cooled by the cooling cylinder 3, and the blown air can be cooled by the air cooling pipe 19 to indirectly cool the shaft body 1, so that the cooling range and amplitude of the shaft body 1 are large, and the heat dissipation effect of the printer shaft is good. The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A printer shaft with a heat dissipation structure, comprising a shaft body (1), characterized in that: Connecting columns (7) are fixed at both ends of the shaft body (1), a ventilation mechanism is provided inside the shaft body (1), cooling mechanisms are installed at both ends of the ventilation mechanism, and a blower mechanism is installed outside the cooling mechanism; The ventilation mechanism comprises air guide holes (14) and heat dissipation holes (2), wherein the air guide holes (14) are evenly arranged on the inner edge of the shaft body (1) along the axial direction of the shaft body (1), and the heat dissipation holes (2) are evenly distributed on the surface of the shaft body (1) and are connected to the air guide holes (14), so as to ventilate and dissipate heat inside the printer shaft; The cooling mechanism comprises a cooling cylinder (3), an air cooling pipe (19) and a coolant circulation mechanism. The cooling cylinder (3) is slidably sleeved on the surface of the connecting column (7), and a silicone pad (13) bonded to the outer end of the shaft body (1) is provided on the inner side thereof. A connecting hole (18) is provided on the surface of the silicone pad (13). The air cooling pipe (19) passes through both ends of the cooling cylinder (3), and an inner end thereof is connected to the connecting hole (18) and the air guide hole (14). The coolant circulation mechanism is connected to both sides of the cooling cylinder (3). The coolant circulation mechanism comprises a liquid inlet pipe (21), a liquid outlet pipe (12), a coolant tank (8) and a micro chiller (20); the top end of the liquid inlet pipe (21) is connected to one side of the cooling cylinder (3), the bottom end of the liquid inlet pipe (21) is communicated with the micro chiller (20), the other side of the micro chiller (20) is communicated with one side of the coolant tank (8) via a pipeline, the top end of the liquid outlet pipe (12) is connected to the other side of the cooling cylinder (3), the bottom end of the liquid outlet pipe (12) is connected to a booster pump (9), and the other side of the booster pump (9) is communicated with the other side of the coolant tank (8) via a pipeline; The air blowing mechanism comprises an air blower (10), an air guide tube (5) and a filter cover (15), and is slidably sleeved on the surface of the connecting column (7) for blowing air to dissipate heat from the printer shaft.

2. The printer shaft with a heat dissipation structure according to claim 1, characterized in that: The air guide tube (5) is slidably sleeved on the surface of the connecting column (7), and is connected to a first blowing pipe (16) on its inner side. The outer end of the first blowing pipe (16) is slidably inserted into the interior of the air cooling tube (19). The outer side of the air guide tube (5) is connected to a second blowing pipe (4). The second blowing pipe (4) is evenly distributed on the outer surface of the cooling tube (3) and is in contact with the cooling tube (3). The filter cover (15) is installed inside the air guide tube (5), and is evenly provided with dust filtering holes (17) on its surface. The side of the blower (10) is connected to a blast pipe (11), and the blast pipe (11) is inserted into the interior of the filter cover (15). The outer side of the air guide tube (5) is threadedly connected to a blocking cover (6), and the inner side of the blocking cover (6) abuts against the rear end of the filter cover (15).

3. The printer shaft with a heat dissipation structure according to claim 1, characterized in that: The connecting column (7) is a cylindrical structure, the air guide hole (14) is arranged horizontally and is connected to the connecting hole (18), the cooling cylinder (3) is a cylindrical structure, and the air cooling pipe (19) is a cylindrical structure and is arranged horizontally.

4. The printer shaft with a heat dissipation structure according to claim 1, characterized in that: The liquid inlet pipe (21) and the liquid outlet pipe (12) are both C-shaped structures and are both arranged, and the booster pump (9), the coolant tank (8) and the micro chiller (20) are all installed below the cooling cylinder (3).

5. The printer shaft with a heat dissipation structure according to claim 2, characterized in that: The air guide cylinder (5) is a cylindrical structure, and the inner side thereof abuts against the outer side of the cooling cylinder (3); the first blowing pipe (16) is a cylindrical structure, and is arranged horizontally.

6. The printer shaft with a heat dissipation structure according to claim 2, characterized in that: The second blowing pipe (4) is of an L-shaped structure and is arranged horizontally, with its air outlet facing the surface of the shaft body (1); the second blowing pipe (4) and the first blowing pipe (16) are both connected to the interior of the air guide tube (5).

7. The printer shaft with a heat dissipation structure according to claim 2, characterized in that: The filter cover (15) is a cylindrical structure, and a gap is provided between the outer surface and the inner surface of the air guide tube (5), and the air inlets of the first blowing pipe (16) and the second blowing pipe (4) are both located outside the filter cover (15).

8. The printer shaft with a heat dissipation structure according to claim 2, characterized in that: The blast pipe (11) passes through the air guide tube (5); the blocking cover (6) is of a circular structure and has an external thread structure on the side; the inner surface of the rear end of the air guide tube (5) is of an internal thread structure and is threadedly connected to the blocking cover (6).

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