Underground excavation construction device for municipal engineering main tunnel

Abstract

The invention discloses an underground excavation construction device for a municipal engineering main tunnel, and relates to the technical field of underground excavation construction. Comprising a crawler base, a device seat is fixedly connected to the top of the crawler base, a sliding table is installed on the left side of the top of the device seat through a lifting machine, and a drilling mechanism and a pipe feeding and cleaning mechanism are arranged in two device grooves correspondingly; the rotating rod is driven by a driving motor on the left side surface of the first driving block, construction congestion caused by alternate entering and exiting of multiple devices in the small-section main tunnel can be effectively avoided, continuous advancing of the construction procedure is guaranteed, rock residues and soil generated during drilling are guided out of the hole along the spiral track of the flow guide piece, drill jamming or hole collapse caused by accumulation of the rock residues in the hole is avoided, and the construction efficiency is improved. The cleaning of the hole wall is synchronously completed in the pipe shed pushing process, so that the bonding strength of grout, the pipe shed and surrounding rock is improved during subsequent grouting, and the stability of a supporting structure is remarkably enhanced.

Description

Technical Field

[0001] This invention relates to the field of tunneling technology, specifically to a tunneling device for main tunnels in municipal engineering projects. Background Technology

[0002] The term "mineral tunneling equipment" refers to a series of specialized devices used in the construction of underground linear engineering projects such as municipal tunnels, underground utility tunnels, and subway tunnels. These devices allow for excavation, slag removal, and support operations underground without requiring extensive surface excavation. The core function of these devices is to minimize the impact on surface traffic, surrounding buildings, and pipelines. They are adaptable to complex urban underground environments. In mineral tunneling construction, for unstable geological conditions such as soft soil, fractured surrounding rock, and water-rich strata, grouting is required to solidify the surrounding rock in front of the tunnel face to prevent collapse during excavation.

[0003] However, existing equipment requires first using a horizontal auger to excavate the required cavern in the soil layer, inserting a special pipe roof into the cavern before grouting to form a rigid support frame, providing safety protection for subsequent excavation. The entire process involves moving the drilling equipment, drilling, removing the drilling equipment, and installing the grouting pipe. Single-hole operations require multiple moves of equipment, and the time intervals between processes affect construction efficiency. At the same time, rock cuttings and dust generated during drilling adhere to the borehole wall and are difficult to clean, causing the grout to mix with these impurities and solidify first, preventing it from penetrating into the surrounding rock fissures and weakening the reinforcement effect.

[0004] To address the aforementioned issues, there is an urgent need for innovative designs based on existing underground excavation equipment. Summary of the Invention

[0005] The purpose of this invention is to provide a tunnel excavation device for municipal engineering, which solves the problems mentioned in the background art, such as the time interval between processes affecting construction efficiency and the difficulty in cleaning rock cuttings and dust generated during the drilling process from adhering to the borehole wall. The technical solution of this invention addresses the problem that the existing technical solutions are too simplistic and provides a solution that is significantly different from the existing technology.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a tunnel excavation device for municipal engineering, comprising a tracked vehicle base, a device seat fixedly connected to the top of the tracked vehicle base, a sliding platform installed on the top left side of the device seat via a lift, a work platform horizontally installed on the top of the sliding platform via a sliding module, a device slot opened on the top of the work platform, the device slot having two sets, and a drilling mechanism and a pipe delivery and cleaning mechanism respectively arranged in the two sets of device slots;

[0007] The drilling mechanism includes a first lead screw rotatably connected to a device slot on the left side of the top of the workbench. A first drive block is sleeved on the surface of the first lead screw. A rotating rod is rotatably connected to the right side surface of the first drive block. The rotating rod is driven by a drive motor on the left side surface of the first drive block. A diamond drill bit is fixedly connected to the end of the rotating rod away from the first drive block. A guide plate is provided on the surface of the rotating rod.

[0008] Preferably, the pipe-feeding cleaning mechanism includes a second lead screw rotatably connected to a device slot on the right side of the top of the workbench. A second drive block is sleeved on the surface of the second lead screw. A sleeve is rotatably connected to the right side of the second drive block. An active bevel gear is rotatably connected inside the cavity of the second drive block. A first driven bevel gear is provided on both sides of the tooth surface of the active bevel gear. The end of the first driven bevel gear away from the tooth surface is rotatably connected to the inner wall of the cavity of the second drive block. A second driven bevel gear is provided to the right side of the active bevel gear. A drive rod is fixedly connected to the right surface of the active bevel gear. The drive rod extends through the second driven bevel gear into the inside of the sleeve and is fixedly connected to a third lead screw. A push plate is sleeved on the surface of the third lead screw inside the sleeve. A cleaning component is installed on the outer surface of the sleeve.

[0009] Preferably, the cleaning assembly includes limiting plates fixedly connected to both sides of the groove on the surface of the sleeve. A cleaning plate is slidably limited inside the limiting plates. A cleaning brush is fixedly connected to the top surface of the cleaning plate. An abutment plate is provided below the cleaning plate. The abutment plate is vertically limited and slidable inside the limiting plates. A spring is fixedly connected to the top of the abutment plate. The other end of the spring is fixedly connected to the bottom of the cleaning plate. An airbag is installed at the bottom of the abutment plate. An air pump is installed in the cavity at the left end of the sleeve. The air pump is connected to the airbag through a hose.

[0010] Preferably, the guide vane is spirally arranged along the surface of the rotating rod, and an acoustic wave detector is installed on the right side surface of the slide table.

[0011] Preferably, the tooth surfaces on both sides of the driving bevel gear mesh with the tooth surfaces of the first driven bevel gear, the tooth surfaces of the first driven bevel gear mesh with the tooth surfaces on both sides of the second driven bevel gear, the end of the second driven bevel gear away from the tooth surface is fixedly connected to the end surface of the sleeve located in the cavity of the second drive block, and the driving bevel gear is driven by a drive motor installed on the left side of the second drive block.

[0012] Preferably, the first lead screw and the second lead screw are driven by drive motors installed on the right side of the workbench, and the first lead screw and the second lead screw are threadedly connected to the first drive block and the second drive block, respectively.

[0013] Preferably, the push plate is threadedly connected to the third lead screw, and a tube shed is placed on the right side surface of the push plate inside the sleeve.

[0014] Preferably, the limiting plate is evenly arranged in six groups on the outer surface of the sleeve, and an air outlet is opened on the left side surface of the sleeve corresponding to the position of the air pump.

[0015] Compared with the prior art, the beneficial effects of the present invention are:

[0016] 1. This invention is equipped with a tracked vehicle base, a device seat, a slide, a work platform, and a sliding module. The lateral movement of the work platform is achieved through the sliding module on the top of the work platform, enabling rapid switching between the drilling mechanism and the pipe delivery and cleaning mechanism. Unlike traditional split equipment, there is no need to repeatedly withdraw the drilling machine and then hoist the pipe delivery equipment to the hole position. This completely eliminates the cumbersome process of equipment relocation and alignment, effectively avoiding construction congestion caused by multiple pieces of equipment alternating in and out of a small cross-section tunnel, and ensuring the continuous progress of the construction process.

[0017] 2. This invention is equipped with a first lead screw, a first drive block, a rotating rod, a diamond drill bit, and a guide vane. By driving the first drive block to feed along the axial direction of the device groove, the drive motor on the left side of the first drive block is started, which drives the rotating rod and the diamond drill bit to rotate at high speed and contact the working face to start drilling. During the drilling process, the spiral guide vane on the surface of the rotating rod rotates synchronously with the rotating rod, and guides the rock cuttings and soil generated during drilling out of the hole along the spiral trajectory of the guide vane, so as to avoid the accumulation of rock cuttings in the hole, which may cause the drill to get stuck or the hole to collapse.

[0018] 3. This invention comprises a second lead screw, a second drive block, a casing, a driving bevel gear, a first driven bevel gear, a second driven bevel gear, a third lead screw, a push plate, and a cleaning assembly. The driving bevel gear rotates, causing the first driven bevel gear to rotate, which in turn drives the second driven bevel gear. Simultaneously, the driving bevel gear rotates the drive rod and the third lead screw on its right side, causing the push plate to move axially along the inside of the casing. This pushes the pre-placed pipe roof into the borehole at a uniform speed, preventing rock debris from falling onto the pipe roof surface and clogging the grouting hole, thus preventing support failure. Simultaneously, the second driven bevel gear drives the casing to rotate synchronously, causing the cleaning assembly to clean the borehole wall. The hardness of the surrounding rock is detected by an acoustic wave detector, which adjusts the cleaning force of the cleaning assembly to avoid damaging the borehole wall, causing the borehole to sag or even collapse. Ultimately, the borehole wall is cleaned simultaneously during the pipe roof pushing process, avoiding secondary pollution caused by the traditional method of cleaning before pipe delivery. This improves the bonding strength between the grout and the pipe roof and surrounding rock during subsequent grouting, significantly enhancing the stability of the support structure. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0020] Figure 2 This is a side sectional view of the overall structure of the present invention;

[0021] Figure 3 This is a top sectional view of the overall structure of the present invention;

[0022] Figure 4 This is a schematic cross-sectional view of the second driving block and sleeve structure of the present invention;

[0023] Figure 5 This is an enlarged schematic diagram of the second driving block structure of the present invention;

[0024] Figure 6 For the present invention Figure 5 Enlarged schematic diagram of the structure at point A in the middle;

[0025] Figure 7 This is a front view cross-sectional diagram of the sleeve structure of the present invention.

[0026] In the diagram: 1. Tracked vehicle base; 2. Device seat; 3. Slide table; 4. Worktable; 5. Device slot; 61. First lead screw; 62. First drive block; 63. Rotating rod; 64. Diamond drill bit; 65. Guide vane; 71. Second lead screw; 72. Second drive block; 73. Sleeve; 74. Driving bevel gear; 75. First driven bevel gear; 76. Second driven bevel gear; 77. Third lead screw; 78. Push plate; 791. Limit plate; 792. Cleaning plate; 793. Cleaning brush; 794. Contact plate; 795. Airbag; 976. Air pump; 8. Acoustic wave detector; 9. Pipe shed. Detailed Implementation

[0027] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] Please see Figures 1-7 The present invention provides a technical solution: a tunnel excavation device for municipal engineering, including a tracked vehicle base 1, a device seat 2 fixedly connected to the top of the tracked vehicle base 1, a slide 3 installed on the top left side of the device seat 2 via a lift, an acoustic detector 8 installed on the right side surface of the slide 3, a work platform 4 horizontally installed on the top of the slide 3 via a sliding module, a device slot 5 opened on the top of the work platform 4, two sets of device slots 5, and a drilling mechanism and a pipe delivery and cleaning mechanism respectively installed in the two sets of device slots 5;

[0029] The operator controls the tracked vehicle base 1 to move to the designated construction area on the tunnel face, completes the rough positioning of the equipment, starts the elevator on the top of the device base 2, adjusts the height of the slide 3 so that the vertical elevation of the work platform 4 is consistent with the design hole position, starts the sliding module on the top of the slide 3, drives the work platform 4 to move laterally, so that the axis of the left drilling mechanism coincides with the axis of the design hole position.

[0030] The drilling mechanism includes a first lead screw 61 rotatably connected to the device slot 5 on the left side of the top of the workbench 4. A first drive block 62 is sleeved on the surface of the first lead screw 61. A rotating rod 63 is rotatably connected to the right side surface of the first drive block 62. The rotating rod 63 is driven by a drive motor on the left side surface of the first drive block 62. A diamond drill bit 64 is fixedly connected to the end of the rotating rod 63 away from the first drive block 62. A guide plate 65 is provided on the surface of the rotating rod 63. A push plate 78 is threadedly connected to a third lead screw 77. A tube shed 9 is placed inside the sleeve 73 on the right side surface of the push plate 78. The guide plate 65 is spirally arranged along the surface of the rotating rod 63.

[0031] Start the drive motor on the left side of the first drive block 62 to drive the rotating rod 63 to rotate. The rotation of the rotating rod 63 drives the diamond drill bit 64 to rotate at high speed and contact the working face to start drilling. During the drilling process, the spiral guide plate 65 on the surface of the rotating rod 63 rotates synchronously with the rotating rod 63, and discharges the rock cuttings and soil generated during drilling out of the hole along the spiral trajectory of the guide plate 65, so as to avoid the rock cuttings accumulating in the hole.

[0032] In one embodiment of the present invention, the pipe-feeding cleaning mechanism includes a second lead screw 71 rotatably connected to a device groove 5 on the right side of the top of the workbench 4. A second driving block 72 is sleeved on the surface of the second lead screw 71. A sleeve 73 is rotatably connected to the right side of the second driving block 72. A driving bevel gear 74 is rotatably connected inside the cavity of the second driving block 72. A first driven bevel gear 75 is provided on both sides of the tooth surface of the driving bevel gear 74. The end of the first driven bevel gear 75 away from the tooth surface is rotatably connected to the inner wall of the cavity inside the second driving block 72. A second driven bevel gear 76 is provided to the right side of the driving bevel gear 74. A driving rod is fixedly connected to the right surface of the driving bevel gear 74. The driving rod passes through the second driven bevel gear 76 and extends into the sleeve 73, and is fixedly connected to a third... The third lead screw 77 has a push plate 78 installed inside the sleeve 73. The tooth surfaces on both sides of the driving bevel gear 74 mesh with the tooth surfaces of the first driven bevel gear 75. The tooth surfaces of the first driven bevel gear 75 mesh with the tooth surfaces on both sides of the second driven bevel gear 76. The end of the second driven bevel gear 76 away from the tooth surface is fixedly connected to the end surface of the sleeve 73 located in the cavity of the second drive block 72. The driving bevel gear 74 is driven by a drive motor installed on the left side of the second drive block 72. The first lead screw 61 and the second lead screw 71 are driven by drive motors installed on the right side of the workbench 4. The first lead screw 61 and the second lead screw 71 are threadedly connected to the first drive block 62 and the second drive block 72, respectively. A cleaning component is installed on the outer surface of the sleeve 73.

[0033] Start the drive motor corresponding to the second lead screw 71 to drive the second drive block 72 to feed axially, and drive the sleeve 73 into the hole. Then start the drive motor on the left side of the second drive block 72 to drive the active bevel gear 74 to rotate. The rotation of the active bevel gear 74 drives the first driven bevel gears 75 on both sides to rotate. The rotation of the first driven bevel gears 75 drives the second driven bevel gear 76 to rotate. At the same time, the rotation of the active bevel gear 74 drives the drive rod on its right side to rotate. The rotation of the drive rod drives the third lead screw 77 to rotate. The third lead screw 77 drives the push plate 78 to move axially along the inside of the sleeve 73, thereby pushing the tube shed 9, which is pre-placed in the sleeve 73, into the channel at a uniform speed. At the same time, the second drive block 72 retracts synchronously to ensure that the tube shed 9 is smoothly inserted into the channel.

[0034] In one embodiment of the present invention, the cleaning component includes a limiting plate 791 fixedly connected to both sides of the groove on the surface of the sleeve 73. A cleaning plate 792 is slidably limited inside the limiting plate 791. A cleaning brush 793 is fixedly connected to the top surface of the cleaning plate 792. An abutment plate 794 is provided below the cleaning plate 792. The abutment plate 794 is vertically limited and slidable inside the limiting plate 791. A spring is fixedly connected to the top of the abutment plate 794. The other end of the spring is fixedly connected to the bottom of the cleaning plate 792. An airbag 795 is installed at the bottom of the abutment plate 794. An air pump 976 is installed in the cavity at the left end of the sleeve 73. The air pump 976 is connected to the airbag 795 through a hose. Six sets of limiting plates 791 are evenly arranged circumferentially on the outer surface of the sleeve 73. An air outlet is opened on the left side surface of the sleeve 73 corresponding to the position of the air pump 976.

[0035] An air pump 976 inflates an airbag 795 at the bottom of the contact plate 794 via a hose. After the airbag 795 inflates, it pushes the contact plate 794 upward. The contact plate 794 compresses the spring at its top. The elastic force generated by the spring pushes the cleaning plate 792 to slide outward along the inner groove of the limiting plate 791 until the cleaning brush 793 at the top of the cleaning plate 792 is tightly attached to the inner wall of the channel. The inflation amount of the airbag 795 is controlled according to the hardness parameter of the surrounding rock to control the force of the cleaning brush 793 in contact with the inner wall of the channel, so as to avoid damaging the hole wall.

[0036] Working principle: When using this municipal engineering tunnel excavation device, the operator first controls the tracked vehicle base 1 to move to the designated construction area on the tunnel face to complete the rough positioning of the equipment. Then, the lifting platform on top of the device base 2 is started, and the height of the slide 3 is adjusted so that the vertical elevation of the work platform 4 is consistent with the designed hole position. The sliding module on top of the slide 3 is then started to drive the work platform 4 to move laterally, so that the axis of the diamond drill bit 64 of the left drilling mechanism coincides with the axis of the designed hole position. Subsequently, the drive motor corresponding to the first lead screw 61 is started to drive the first drive block 62 to move axially along the device groove 5. Simultaneously, the drive motor on the left side of the first drive block 62 is started, driving the rotating rod 63 to rotate. The rotation of the rotating rod 63 drives the diamond drill bit 64 to rotate at high speed, contacting the working face to start drilling. During the drilling process, the spiral guide vane 65 on the surface of the rotating rod 63 rotates synchronously with the rotating rod 63, discharging the rock cuttings and soil generated during drilling out of the hole along the spiral trajectory of the guide vane 65, avoiding the accumulation of rock cuttings in the hole. When the drilling depth reaches the design requirements, the drive motor stops working, and the first drive block 62 drives the rotating rod 63 and the drill bit to retract to the initial position, and the drilling operation is completed.

[0037] The sliding module drives the worktable 4 to move laterally, precisely aligning the axis of the casing 73 of the right-side pipe-feeding cleaning mechanism with the axis of the newly drilled hole. Simultaneously, the drive motor corresponding to the second lead screw 71 is activated, driving the second drive block 72 to feed axially, bringing the casing 73 into the hole. At the same time, the acoustic detector 8 on the right side of the sliding table 3 scans the surrounding rock at the working face to obtain the rock hardness parameters. This allows the air pump 976 in the cavity at the left end of the casing 73 to inflate the airbag 795 at the bottom of the contact plate 794 through a hose. After the airbag 795 inflates, it pushes the contact plate 794 upwards, compressing the spring at its top. The spring force pushes the cleaning plate 792 outwards along the inner groove of the limiting plate 791 until the cleaning brush 793 at the top of the cleaning plate 792 is tightly attached to the inner wall of the hole. The inflation amount of the airbag 795 is controlled according to the rock hardness parameters to control the adhesion of the cleaning brush 793. The force applied to the inner wall of the borehole is adjusted to avoid damage to the borehole wall. Then, the drive motor on the left side of the second drive block 72 is activated, which drives the active bevel gear 74 to rotate. The rotation of the active bevel gear 74 drives the first driven bevel gears 75 on both sides to rotate. The rotation of the first driven bevel gears 75 drives the second driven bevel gear 76 to rotate. The second driven bevel gear 76 drives the casing 73 to rotate. The cleaning brush 793 on the periphery of the casing 73 rotates synchronously with the casing 73 to clean the rock debris and dust remaining on the borehole wall. At the same time, the rotation of the active bevel gear 74 drives the drive rod on its right side to rotate. The rotation of the drive rod drives the third lead screw 77 to rotate. The third lead screw 77 drives the push plate 78 to move axially along the inside of the casing 73, thereby pushing the pipe shed 9, which is pre-placed in the casing 73, into the borehole at a uniform speed. At the same time, the second drive block 72 retracts synchronously to ensure that the pipe shed 9 is smoothly inserted into the borehole. The drive motor stops working, and the pipe delivery and cleaning operations are completed simultaneously.

[0038] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A tunnel excavation device for municipal engineering, comprising a tracked vehicle base (1), characterized in that: The tracked vehicle base (1) is fixedly connected to a device seat (2) on the top. A slide (3) is installed on the top left side of the device seat (2) via a lift. A work platform (4) is installed horizontally on the top of the slide (3) via a sliding module. A device slot (5) is opened on the top of the work platform (4). Two sets of device slots (5) are opened. A drilling mechanism and a pipe feeding and cleaning mechanism are respectively installed in the two sets of device slots (5). The drilling mechanism includes a first lead screw (61) rotatably connected in the device slot (5) on the top left of the worktable (4). A first drive block (62) is sleeved on the surface of the first lead screw (61). A rotating rod (63) is rotatably connected to the right surface of the first drive block (62). The rotating rod (63) is driven by a drive motor on the left surface of the first drive block (62). A diamond drill bit (64) is fixedly connected to one end of the rotating rod (63) away from the first drive block (62). A guide plate (65) is provided on the surface of the rotating rod (63).

2. The tunnel excavation device for municipal engineering main tunnels according to claim 1, characterized in that: The pipe-feeding cleaning mechanism includes a second lead screw (71) rotatably connected to a device slot (5) on the right side of the top of the workbench (4). A second drive block (72) is sleeved on the surface of the second lead screw (71). A sleeve (73) is rotatably connected to the right side of the second drive block (72). A drive bevel gear (74) is rotatably connected inside the cavity of the second drive block (72). A first driven bevel gear (75) is provided on both sides of the tooth surface of the drive bevel gear (74). The first driven bevel gear (75) is located away from the tooth surface of the first driven bevel gear (75). The end is rotatably connected to the inner wall of the cavity inside the second drive block (72). A second driven bevel gear (76) is provided on the right side of the active bevel gear (74). A drive rod is fixedly connected to the right surface of the active bevel gear (74). The drive rod extends through the second driven bevel gear (76) into the inside of the sleeve (73) and is fixedly connected to a third lead screw (77). A push plate (78) is sleeved on the surface of the third lead screw (77) inside the sleeve (73). A cleaning component is installed on the outer surface of the sleeve (73).

3. The tunnel excavation device for municipal engineering main tunnels according to claim 2, characterized in that: The cleaning assembly includes a limiting plate (791) fixedly connected to both sides of a groove on the surface of the sleeve (73). A cleaning plate (792) is slidably limited inside the limiting plate (791). A cleaning brush (793) is fixedly connected to the top surface of the cleaning plate (792). An abutment plate (794) is provided below the cleaning plate (792). The abutment plate (794) is vertically limited and slid inside the limiting plate (791). A spring is fixedly connected to the top of the abutment plate (794). The other end of the spring is fixedly connected to the bottom of the cleaning plate (792). An airbag (795) is installed at the bottom of the abutment plate (794). An air pump (976) is installed in the cavity at the left end of the sleeve (73). The air pump (976) is connected to the airbag (795) through a hose.

4. The tunnel excavation device for municipal engineering main tunnels according to claim 1, characterized in that: The guide vane (65) is spirally arranged along the surface of the rotating rod (63), and an acoustic wave detector (8) is installed on the right side surface of the slide (3).

5. The tunnel excavation device for municipal engineering main tunnels according to claim 2, characterized in that: The tooth surfaces on both sides of the driving bevel gear (74) mesh with the tooth surfaces of the first driven bevel gear (75), the tooth surfaces of the first driven bevel gear (75) mesh with the tooth surfaces on both sides of the second driven bevel gear (76), and the end of the second driven bevel gear (76) away from the tooth surface is fixedly connected to the end surface of the sleeve (73) located in the cavity of the second drive block (72). The driving bevel gear (74) is driven by a drive motor installed on the left side of the second drive block (72).

6. The tunnel excavation device for municipal engineering main tunnels according to claim 2, characterized in that: The first lead screw (61) and the second lead screw (71) are driven by drive motors installed on the right side of the workbench (4), and the first lead screw (61) and the second lead screw (71) are threadedly connected to the first drive block (62) and the second drive block (72), respectively.

7. The tunnel excavation device for municipal engineering main tunnels according to claim 2, characterized in that: The push plate (78) is threadedly connected to the third lead screw (77), and a tube shed (9) is placed inside the sleeve (73) on the right side surface of the push plate (78).

8. The tunnel excavation device for municipal engineering main tunnels according to claim 3, characterized in that: The limiting plate (791) is evenly arranged in six groups on the outer surface of the sleeve (73), and an air outlet is opened on the left side surface of the sleeve (73) corresponding to the position of the air pump (976).

Images