Spinning device for melt-blowing non-woven fabric

Abstract

The utility model discloses a spinning device for melt-blowing non-woven fabrics, which comprises a spinning device body, auxiliary cooling components are arranged on the right side of an upper driven roller and the right side of a conveying belt, and a first industrial air cooler works to blow cold air with a preset temperature to a first air inlet pipe. Then cold air sequentially passes through a first air inlet pipe, an air guide pipe and a plurality of air nozzles to be sprayed out towards the lower left part, so that silk fibers passing through the conveying belt are subjected to air cooling again, and the situation that the silk fibers with residual heat are adhered to the conveying belt and are not easily scraped off and stripped by a subsequent scraping knife is avoided; a second industrial air cooler works to blow cold air with the preset temperature to a second air inlet pipe, then the cold air enters an air passing cavity through a first hollow supporting shaft to cool an upper driven rotating roller, and the cooled upper driven rotating roller adsorbs part of heat in a passing conveying belt; therefore, auxiliary cooling is carried out on the conveying belt.

Description

Technical Field

[0001] This utility model relates to the field of meltblown nonwoven fabric spinning technology, specifically a spinning device for meltblown nonwoven fabric. Background Technology

[0002] Meltblown nonwoven fabric is a type of nonwoven fabric that is directly formed into a web through a meltblown process. Its main raw material is polypropylene. In the production and processing of meltblown nonwoven fabric, molten polypropylene material is fed into a spinneret through a feeder for spinning and cooling to form meltblown nonwoven fabric.

[0003] In the use of existing spinnerets, a conveying structure is required to transport the cooled meltblown nonwoven fabric. However, the conveying structure used in existing spinnerets does not have the ability to assist in cooling and cannot cool down the residual heat of the fibers on the conveyor belt. As a result, the fibers with residual heat tend to stick to the conveyor belt and are not easy to peel off, which makes them impractical. Utility Model Content

[0004] The purpose of this invention is to provide a spinneret for meltblown nonwoven fabrics to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, this utility model provides the following technical solution:

[0006] A spinning device for meltblown nonwoven fabric includes a spinning device body, a spinning plate, a conveyor belt, a servo motor, a driving roller, an upper driven roller, a lower driven roller, a base plate, and side support plates. Four sets of side support plates are fixedly connected to the upper surface of the base plate. A servo motor is mounted on the side of each side support plate. The drive end of the servo motor is connected to the driving roller. An upper driven roller is mounted to the right of the driving roller, and a lower driven roller is mounted below the upper driven roller. The driving roller and the upper driven roller... A conveyor belt is provided between the rotating roller and the lower driven rotating roller. A spinneret body is provided above the conveyor belt, and a spinneret plate is provided on the lower end face of the spinneret body. An auxiliary cooling component is provided on the right side of both the upper driven rotating roller and the conveyor belt. The auxiliary cooling component is used to provide auxiliary cooling for the meltblown nonwoven fabric on the upper driven rotating roller and the conveyor belt, respectively. A delivery component is provided below the conveyor belt. The delivery component is used to convey the meltblown nonwoven fabric that falls from the conveyor belt to the next process.

[0007] Preferably, the auxiliary cooling component includes an air duct, a nozzle, a first air inlet pipe, a first industrial air cooler, and a support rod. The support rod is fixedly connected to the upper side of the right end face of the side support plate, the air duct is fixedly connected to the right end of the support rod, a plurality of nozzles are fixedly connected to the annular side of the air duct, the first air inlet pipe is connected to the rear end inlet of the air duct, and the first industrial air cooler is installed at the lower end inlet of the first air inlet pipe.

[0008] Preferably, an air passage cavity is formed inside the upper driven roller, and a plurality of first blocking plates are fixedly connected inside the air passage cavity. A second blocking plate is fixedly connected between each of the plurality of first blocking plates, and the second blocking plates and the first blocking plates are arranged alternately. A first hollow support shaft is provided at the rear end of the upper driven roller, and a second hollow support shaft is provided at the front end of the upper driven roller.

[0009] Preferably, both the first hollow support shaft and the second hollow support shaft are provided with limit rings on their annular sides, and both the first hollow support shaft and the second hollow support shaft are fitted with shaft sealing rings. A second air inlet pipe is inserted into the rear end of the first hollow support shaft, and a second industrial air cooler is installed at the rear inlet of the second air inlet pipe.

[0010] Preferably, the feeding assembly includes a driving pulley, a transmission belt, a driven pulley, a follower roller, a feeding belt, a support frame, and an auxiliary roller. The driving pulley is located at the front end of the lower driven roller, and the driven pulley is located below the driving pulley. A transmission belt connects the driven pulley and the driving pulley. The follower roller is connected to the rear end of the driven pulley. A support frame is fixedly connected to the right side of the upper surface of the base plate. An auxiliary roller is installed inside the support frame, and a feeding belt is provided between the auxiliary roller and the follower roller.

[0011] Preferably, a support block is fixedly connected to the right end face of the side support plate, a scraper is installed on the right end face of the support block, and the left end face of the scraper is attached to the right end face of the conveyor belt. The front-to-back length of the scraper is greater than the front-to-back width of the conveyor belt.

[0012] Preferably, a connecting pipe is inserted into the front end of the second hollow support shaft, a positioning support rod is fixedly connected to the lower side of the annular side of the connecting pipe, and an exhaust hose is connected to the front end of the connecting pipe.

[0013] Compared with the prior art, the beneficial effects of this utility model are:

[0014] 1. By operating the first industrial air cooler, cold air at a preset temperature is blown into the first air inlet pipe. The cold air then passes through the first air inlet pipe, the air guide pipe and multiple nozzles and is sprayed out to the lower left. This cools the fibers passing on the conveyor belt again, preventing the fibers with residual heat from sticking to the conveyor belt and being difficult to be scraped off by the subsequent scraping knife.

[0015] 2. By operating the second industrial air cooler, cold air at a preset temperature is blown into the second air inlet pipe. The cold air then passes through the first hollow support shaft and enters the air passage cavity to cool the upper driven roller. The cooled upper driven roller absorbs some of the heat inside the conveyor belt, thereby assisting in cooling the conveyor belt. Furthermore, multiple first and second baffles, which are staggered and fixedly connected inside the air passage cavity, can extend the path of the cold air in the air passage cavity so that the passing cold air can better cool the upper driven roller.

[0016] 3. By setting up a driving pulley, a driven pulley, and a transmission pulley, the rotating lower driven roller can drive the follower roller to rotate together. The rotating follower roller will drive the feed belt to perform a conveying action, so that the feed belt can transport the filaments scraped off by the scraper to the next process for processing. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the main structure of this utility model;

[0018] Figure 2 This is a structural diagram of the auxiliary cooling component and the delivery component in this utility model;

[0019] Figure 3 This is a structural diagram of the upper driven roller in this utility model;

[0020] Figure 4 This is a cross-sectional view of the upper driven roller in this utility model;

[0021] Figure 5 for Figure 2 A magnified view of A in the middle.

[0022] In the diagram: 1. Spinneret body; 2. Spinneret plate; 3. Conveyor belt; 4. Servo motor; 5. Driven roller; 6. Upper driven roller; 7. Lower driven roller; 81. Second hollow support shaft; 82. Connecting pipe; 83. Exhaust hose; 84. Positioning support rod; 85. Air guide pipe; 86. Air nozzle; 87. First air inlet pipe; 88. First industrial air cooler; 89. Second industrial air cooler; 811. Second air inlet pipe; 81 2. Limiting ring; 813. Shaft sealing ring; 814. First hollow support shaft; 815. First blocking plate; 816. Second blocking plate; 817. Air passage cavity; 818. Support rod; 91. Drive pulley; 92. Transmission belt; 93. Driven pulley; 94. Follower roller; 95. Feeding belt; 96. Support frame; 97. Auxiliary roller; 10. Base plate; 11. Side support plate; 111. Support block; 112. Scraper. Detailed Implementation

[0023] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0024] Please see Figures 1-5 This utility model provides a technical solution:

[0025] Example 1:

[0026] A spinning device for meltblown nonwoven fabric includes a spinning device body 1, a spinning plate 2, a conveyor belt 3, a servo motor 4, a driving roller 5, an upper driven roller 6, a lower driven roller 7, a base plate 10, and side support plates 11. Four sets of side support plates 11 are fixedly connected to the upper surface of the base plate 10. The base plate 10 is fixed to a designated position on the floor of the processing workshop by external expansion bolts. The side support plates 11 are connected to the base plate 10 by welding. The base plate 10 can support the side support plates 11, the support frame 96, and the spinning device body 1 respectively. A servo motor 4 is installed on the side of the side support plate 11. The servo motor 4 is connected to an external servo controller via a wire. A drive roller 5 is connected to the drive end of the servo motor 4. An upper driven roller 6 is installed to the right of the drive roller 5, and a lower driven roller 7 is installed below the upper driven roller 6. All three rollers—drive roller 5, upper driven roller 6, and lower driven roller 7—are rotatable. A conveyor belt 3 is installed between the drive roller 5, the upper driven roller 6, and the lower driven roller 7. The conveyor belt 3 is made of high-temperature resistant material. When the servo motor 4 is working, it can drive the drive roller 5 to rotate at a preset speed, causing the drive roller 5 to drive the conveyor belt 3 to perform a conveying action. The conveying direction of the conveyor belt 3 is... Figure 1 As shown in the diagram, during this process, the conveyor belt 3 will drive the upper driven roller 6 and the lower driven roller 7 to rotate, thereby ensuring the conveying stability of the conveyor belt 3.

[0027] A spinneret body 1 is installed above the conveyor belt 3. A spinneret plate 2 is installed on the lower end face of the spinneret body 1. Air coolers (not shown in the figure) are installed on both sides of the spinneret plate 2. When the spinneret body 1 is working, it can spin the molten polypropylene material that has entered into it downward through the spinneret plate 2. At the same time, the air cooler will quickly cool down the spun fibers to form meltblown nonwoven fabric. Since the detailed internal structure and working principle of the spinneret body 1, the spinneret plate 2 and the air cooler are relatively mature technologies in the prior art, they will not be described in detail here. An auxiliary cooling component is installed on the right side of the upper driven roller 6 and the conveyor belt 3. The auxiliary cooling component is used to assist in cooling the meltblown nonwoven fabric on the upper driven roller 6 and the conveyor belt 3 respectively, so as to avoid the heat accumulation of the conveyor belt 3 during use and affect the subsequent peeling of the meltblown fabric by the scraper 112. A delivery component is installed below the conveyor belt 3. The delivery component is used to transport the meltblown nonwoven fabric that falls from the conveyor belt 3 to the next process.

[0028] A support block 111 is fixedly connected to the right end face of the side support plate 11. The support block 111 is connected to the side support plate 11 by welding. The support block 111 can support the scraper 112. The scraper 112 is installed on the right end face of the support block 111, and the left end face of the scraper 112 is attached to the right end face of the conveyor belt 3. The front and rear length of the scraper 112 is greater than the front and rear width of the conveyor belt 3. The scraper 112, whose left end face is attached to the right end face of the conveyor belt 3, can scrape off the passing meltblown cloth, so that the meltblown cloth falls down onto the delivery belt 95 and is transported to the next process. The scraper 112 is a separately detachable structure, so that the scraper 112 can be replaced by the staff later.

[0029] The auxiliary cooling assembly includes an air duct 85, nozzles 86, a first air inlet pipe 87, a first industrial air cooler 88, and a support rod 818. The support rod 818 is fixedly connected to the upper right side of the side support plate 11. The support rod 818 is welded to both the side support plate 11 and the air duct 85. The support rod 818 supports and fixes the air duct 85. The air duct 85 is fixedly connected to the right end of the support rod 818. The front end of the air duct 85 is sealed, allowing it to distribute cool air to multiple nozzles 86. Multiple nozzles 86 are fixedly connected to the annular side of the air duct 85, and all nozzles 86 are tilted downwards. Multiple inclined nozzles 86 can exhaust cold air to the lower left to further cool the meltblown fabric. The inlet of the air duct 85 is connected to the first air inlet pipe 87. The first air inlet pipe 87 can guide the cold air delivered by the first industrial air cooler 88 into the air duct 85. The first industrial air cooler 88 is installed at the lower inlet of the first air inlet pipe 87. The first industrial air cooler 88 is electrically connected to an external control cabinet through wires. When the first industrial air cooler 88 is working, it can blow cold air into the first air inlet pipe 87. Since the detailed internal structure and working principle of the first industrial air cooler 88 are relatively mature technologies in the existing technology, they will not be described in detail here.

[0030] An air passage 817 is formed inside the upper driven roller 6. The air passage 817 facilitates the entry of cold air from inside the first hollow support shaft 814 into the upper driven roller 6 for cooling. Multiple first baffles 815 are fixedly connected inside the air passage 817, and second baffles 816 are fixedly connected between each of the multiple first baffles 815. The second baffles 816 and the first baffles 815 are arranged alternately. This alternate arrangement of the multiple first baffles 815 and second baffles 816 extends the path of the cold air through the air passage 817, allowing the passing cold air to better cool the upper driven roller 6. A first hollow support shaft is provided at the rear end of the upper driven roller 6. The support shaft 814 and the upper driven roller 6 are provided with a second hollow support shaft 81 at the front end. The first hollow support shaft 814 and the second hollow support shaft 81 are both inserted inside the side support plate 11. The first hollow support shaft 814 and the second hollow support shaft 81 are connected to the upper driven roller 6 by welding. The first hollow support shaft 814 and the second hollow support shaft 81 not only support the upper driven roller 6, but also facilitate the dissipation of external cold air through the interior of the upper driven roller 6. The upper driven roller 6 is made of aluminum alloy. The aluminum alloy upper driven roller 6 has better thermal conductivity, so as to conduct some of the heat of the conveyor belt 3.

[0031] Both the first hollow support shaft 814 and the second hollow support shaft 81 are provided with limiting rings 812 on their annular sides. The limiting rings 812 are integral with the first hollow support shaft 814 and the second hollow support shaft 81. The limiting rings 812 can limit the first hollow support shaft 814 and the second hollow support shaft 81 to prevent displacement of the first hollow support shaft 814 and the second hollow support shaft 81 during rotation. The first hollow support shaft 814 and the second hollow support shaft 81 are both fitted with shaft sealing rings 813. The shaft sealing rings 813 are matched with the connecting pipe 82 and the second air intake pipe 811, respectively. The shaft sealing rings 813 improve the sealing between the connecting pipe 82 and the second hollow support shaft 81, and between the second air intake pipe 811 and the first hollow support shaft 814.

[0032] A second air inlet pipe 811 is inserted into the rear end of the first hollow support shaft 814. The second air inlet pipe 811 can guide the cold air delivered by the second industrial air cooler 89 into the first hollow support shaft 814. The second industrial air cooler 89 is installed at the rear inlet of the second air inlet pipe 811. The second industrial air cooler 89 is electrically connected to an external control cabinet via wires. When the second industrial air cooler 89 is working, it can blow cold air into the second air inlet pipe 811. Since the detailed internal structure and working principle of the second industrial air cooler 89 are relatively mature technologies in the prior art, they will not be described in detail here. The front end of the second hollow support shaft 81... A connecting pipe 82 is inserted, which can guide the cold air in the first hollow support shaft 814 into the connecting pipe 82. A positioning support rod 84 is fixedly connected to the lower side of the annular side of the connecting pipe 82. The positioning support rod 84 is connected to the connecting pipe 82 and the side support plate 11 by welding. The positioning support rod 84 can support and fix the connecting pipe 82 to prevent the connecting pipe 82 from loosening and slipping during use. An exhaust hose 83 is connected to the front end of the connecting pipe 82. The outlet of the exhaust hose 83 is connected to the external workshop exhaust port. The exhaust hose 83 can exhaust the air discharged from the connecting pipe 82 to the outside. A hose clamp is installed on the annular side. Figure 3 (As shown in the drawing), the hose clamp can fix the exhaust hose 83 to the annular side of the connecting pipe 82 for connection and use.

[0033] Example 2:

[0034] Based on Embodiment 1, this embodiment sets up an active pulley 91, a driven pulley 93, and a transmission belt 92, so that the rotating lower driven roller 7 can drive the follower roller 94 to rotate together. The rotating follower roller 94 will drive the delivery belt 95 to perform a conveying action, so that the delivery belt 95 can convey the filaments scraped off by the scraper 112 to the next process for processing.

[0035] The feeding assembly includes a drive pulley 91, a transmission belt 92, a driven pulley 93, a follower roller 94, a feeding belt 95, a support frame 96, and an auxiliary roller 97. The drive pulley 91 is located at the front end of the lower driven roller 7, and the drive pulley 91 and the lower driven roller 7 are integrally formed. Below the drive pulley 91 is the driven pulley 93, which is also integrally formed with the follower roller 94. A transmission belt 92 connects the driven pulley 93 and the drive pulley 91. When the lower driven roller 7 rotates, it drives the drive pulley 91 to rotate as well. The drive pulley 91 then drives the driven pulley 93 to rotate via the transmission belt 92. The driven pulley 93, in turn, drives the follower roller 94 to rotate, which in turn drives the feeding belt 95 to rotate and perform the conveying action (the conveying direction of the feeding belt 95 is...). Figure 1 (Already drawn in the middle).

[0036] A follower roller 94 is connected to the rear end of the driven pulley 93. The follower roller 94 is a rotatable structure and can drive the delivery belt 95 to perform conveying motion. A support frame 96 is fixedly connected to the right side of the upper end face of the base plate 10. The support frame 96 can support and limit the auxiliary roller 97. The auxiliary roller 97 is installed inside the support frame 96. The auxiliary roller 97 is a rotatable structure and makes the delivery belt 95 more stable. The delivery belt 95 is set between the auxiliary roller 97 and the follower roller 94. An annular cover (shown in the figure) is installed on the lower side of the front end face of the side support plate 11. Follower rings (not shown in the figure) are set on the front side of the annular side of the lower driven roller 7 and the follower roller 94. The annular cover and the follower ring can limit the lower driven roller 7 and the follower roller 94 to prevent displacement during rotation.

[0037] Working Principle: During the operation of this device, the operator first starts the servo motor 4, which drives the conveyor belt 3 to perform a conveying action at a preset speed via the active roller 5. The conveyor belt 3 drives the upper driven roller 6 and the lower driven roller 7 to rotate together. Then, the spinneret body 1 is started, causing the molten polypropylene material inside to be spun downwards through the spinneret 2. The spun fibers are quickly cooled by the working air cooler and fall onto the conveyor belt 3, which then transports the fallen fibers to the right. At the same time, the first industrial air cooler 88 is started, blowing cold air into the first air inlet 87. The first air inlet 87 guides the cold air into the air guide 85. Finally, the cold air entering the air guide 85 is sprayed downwards and to the left by multiple nozzles 86 to further cool the passing fibers, preventing residual heat from sticking to the conveyor belt 3 and making them difficult to remove later. The scraping blade 112 continues to scrape and peel off the material; at the same time, the staff starts the second industrial air cooler 89, which blows cold air into the air passage chamber 817 through the second air inlet pipe 811 and the first hollow support shaft 814. The cold air passing through the air passage chamber 817 cools down the upper driven roller 6, which is made of aluminum alloy. The cooled upper driven roller 6, which is made of aluminum alloy, will absorb some of the heat inside the conveyor belt 3, thereby assisting in cooling down the conveyor belt 3. In this process, the multiple staggered first baffles 815 and second baffles 816 can extend the path of the cold air in the air passage chamber 817, so that the cold air can better cool down the upper driven roller 6. Finally, the air that has absorbed heat will be discharged to the outside through the second hollow support shaft 81, the connecting pipe 82 and the exhaust hose 83, so that the second industrial air cooler 89 can continuously assist in cooling down the upper driven roller 6.

[0038] While conveying the extruded fibers on the conveyor belt 3, it also drives the lower driven roller 7 to rotate. The lower driven roller 7 drives the drive pulley 91 to rotate, which in turn drives the driven pulley 93 to rotate together via the transmission belt 92. This causes the driven pulley 93 to drive the delivery belt 95 to perform a conveying action via the follower roller 94 (the conveying direction of the delivery belt 95 is shown in the figure). This allows the delivery belt 95 to convey the fibers scraped off by the scraper 112 to the next processing step.

[0039] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A spinneret for meltblown nonwoven fabric, comprising a spinneret body (1), a spinneret plate (2), a conveyor belt (3), a servo motor (4), a drive roller (5), an upper driven roller (6), a lower driven roller (7), a bottom plate (10), and a side support plate (11), characterized in that: Four sets of side support plates (11) are fixedly connected to the upper end face of the base plate (10). A servo motor (4) is installed on the side of the side support plate (11). The transmission end of the servo motor (4) is connected to an active roller (5). An upper driven roller (6) is installed to the right of the active roller (5). A lower driven roller (7) is installed below the upper driven roller (6). A conveyor belt (3) is provided between the active roller (5), the upper driven roller (6), and the lower driven roller (7). A spinneret body (1) is provided above the conveyor belt (3). A spinneret plate (2) is provided on the lower end face of the spinneret body (1). An auxiliary cooling component is provided on the right side of both the upper driven roller (6) and the conveyor belt (3). The auxiliary cooling component is used to provide auxiliary cooling for the meltblown nonwoven fabric on the upper driven roller (6) and the conveyor belt (3). A delivery component is provided below the conveyor belt (3). The delivery component is used to transport the meltblown nonwoven fabric that falls off the conveyor belt (3) to the next process.

2. The spinning device for meltblown nonwoven fabric according to claim 1, characterized in that: The auxiliary cooling component includes an air duct (85), a jet nozzle (86), a first air inlet pipe (87), a first industrial air cooler (88), and a support rod (818). The support rod (818) is fixedly connected to the upper side of the right end face of the side support plate (11). The air duct (85) is fixedly connected to the right end of the support rod (818). Multiple jet nozzles (86) are fixedly connected to the annular side of the air duct (85). The first air inlet pipe (87) is connected to the rear end inlet of the air duct (85). The first industrial air cooler (88) is installed at the lower end inlet of the first air inlet pipe (87).

3. The spinning device for meltblown nonwoven fabric according to claim 1, characterized in that: The upper driven roller (6) has an air passage cavity (817) inside. Multiple first blocking plates (815) are fixedly connected inside the air passage cavity (817). A second blocking plate (816) is fixedly connected between the multiple first blocking plates (815). The second blocking plates (816) and the first blocking plates (815) are arranged alternately. A first hollow support shaft (814) is provided at the rear end of the upper driven roller (6), and a second hollow support shaft (81) is provided at the front end of the upper driven roller (6).

4. A spinning device for meltblown nonwoven fabric according to claim 3, characterized in that: The first hollow support shaft (814) and the second hollow support shaft (81) are both provided with limit rings (812) on their annular sides. The first hollow support shaft (814) and the second hollow support shaft (81) are both fitted with shaft sealing rings (813). The rear end of the first hollow support shaft (814) is fitted with a second air inlet pipe (811). The rear end inlet of the second air inlet pipe (811) is fitted with a second industrial air cooler (89).

5. A spinning device for meltblown nonwoven fabric according to claim 1, characterized in that: The delivery assembly includes a drive pulley (91), a transmission belt (92), a driven pulley (93), a follower roller (94), a delivery belt (95), a support frame (96), and an auxiliary roller (97). The lower driven roller (7) has a drive pulley (91) at its front end and a driven pulley (93) below it. A transmission belt (92) connects the driven pulley (93) to the drive pulley (91). The follower roller (94) is connected to the rear end of the driven pulley (93). A support frame (96) is fixedly connected to the right side of the upper surface of the base plate (10). An auxiliary roller (97) is installed inside the support frame (96). A delivery belt (95) is provided between the auxiliary roller (97) and the follower roller (94).

6. A spinning device for meltblown nonwoven fabric according to claim 1, characterized in that: The right end face of the side support plate (11) is fixedly connected to a support block (111), and a scraper (112) is installed on the right end face of the support block (111). The left end face of the scraper (112) is attached to the right end face of the conveyor belt (3). The front and rear length of the scraper (112) is greater than the front and rear width of the conveyor belt (3).

7. A spinning device for meltblown nonwoven fabric according to claim 3, characterized in that: The second hollow support shaft (81) has a connecting pipe (82) inserted at its front end. The lower side of the annular side of the connecting pipe (82) is fixedly connected to a positioning support rod (84). The front end of the connecting pipe (82) is connected to an exhaust hose (83).

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