Overhaul device for disassembly and assembly of exhaust valve of reciprocating compressor

Abstract

The utility model relates to an overhauling device for dismounting and mounting an exhaust valve of a reciprocating compressor, which comprises a base and a connecting rod of which the upper end is used for being connected with the exhaust valve, and is characterized by further comprising a base and a movable seat which is restrained on the base and can horizontally move relative to the base, the middle of the base is supported on the stand column and can rotate up and down relative to the stand column through a first pin shaft, and the middle of the connecting rod is hinged to one end of the base through a second pin shaft and can rotate left and right relative to the base. When the exhaust valve is used, the base and the connecting rod can be driven to move to required positions by the aid of horizontal movement of the movable seat, the connecting rod can be driven to rotate in a labor-saving manner by the aid of the lever principle that the middle of the base is hinged to the stand column and the middle of the connecting rod is hinged to the base, and the exhaust valve can be easily mounted and dismounted. Therefore, the connecting rod can be conveniently moved and rotated without hoisting equipment, so that the connecting rod can be quickly lifted, and the exhaust valve can be assembled and disassembled in a more labor-saving manner.

Description

Technical Field

[0001] The utility model relates to the technical field of an overhaul device, in particular to an overhaul device mainly used for disassembling and assembling an exhaust valve of a reciprocating compressor. Background Art

[0002] Reciprocating compressors are used in different technical fields, especially in the production equipment in the field of petroleum refining. The reciprocating compressors in the production equipment often use large reciprocating compressors, which are the core key equipment in the whole production equipment. The stability and efficiency of their operation are extremely important for the whole production equipment and even the production of the whole company. Due to the structural characteristics of the connection and operation of the parts of this type of large reciprocating compressor and the characteristics of the production process, there will always be periodic failures in operation and need to be inspected and repaired. In addition to the planned overhaul, preventive and minor repairs are also common. The disassembly and assembly of the air valves in this type of large reciprocating compressor is an important operation in the maintenance, and the air valves (intake valves and exhaust valves) in this type of large reciprocating compressor are characterized by large number, large size and heavy weight, and the exhaust valves are often installed in a 90° downward or 45° downward manner. Since the exhaust valve is installed in a small and low environment, the subsequent maintenance space is very limited, and sometimes only one person can operate it independently. Therefore, this relatively bulky exhaust valve brings great inconvenience to the maintenance work, especially the exhaust valve installed at the bottom of the cylinder body. Even if multiple people cooperate, they are unable to use their strength. The process is repetitive and painful, and there is also the risk of injury to personnel due to the exhaust valve falling.

[0003] For this purpose, people have designed a maintenance device for disassembling and assembling the exhaust valve, such as the "Large Reciprocating Compressor Valve Disassembly and Assembly Tool" with Chinese Patent Authorization Announcement No. CN203485141U, which includes a bracket, a handle arranged at the left end of the bracket, and an angle adjustment disk arranged at the right end of the bracket. A lifting ring is arranged between the handle and the angle adjustment disk on the bracket. The lower end of the angle adjustment rod is connected to the angle adjustment disk and the bracket by a connecting pin. The upper end of the angle adjustment rod is provided with a valve lifting rod, and the upper end of the valve lifting rod is provided with a valve installation head. When in use, first adjust the installation angle on the angle adjustment disk, fix the angle adjustment rod in the positioning pin hole of the angle adjustment disk with a connecting pin, lift the disassembly and assembly tool with a lifting device through the lifting ring, and adjust the position of the valve lifting rod by rotating the nut at the lower end of the valve lifting rod. The operator can operate the disassembly and assembly of the valve by holding the handle. The above-mentioned disassembly and assembly tool has the advantages of easy use, labor saving, and high efficiency when disassembling the valve.

[0004] However, the above-mentioned disassembly and assembly tools are only applicable to occasions with lifting equipment, and the adjustment of the valve lifting rod still requires manual rotation (threaded connection) for operation. Therefore, the use occasions of such disassembly and assembly tools are limited, and the disassembly and assembly efficiency needs to be further improved. Utility Model Content

[0005] The technical problem to be solved by the utility model is to provide a maintenance device for disassembling and assembling an exhaust valve of a reciprocating compressor, which is more convenient for disassembling and assembling, in view of the current status of the prior art.

[0006] The utility model solves the above technical problems by adopting the following technical solution: a maintenance device for disassembling and assembling the exhaust valve of a reciprocating compressor, comprising a base and a connecting rod at the upper end for connecting the exhaust valve, characterized in that it also comprises a base and a movable seat constrained on the base and capable of horizontally moving relative to the base, a column standing upright on the movable seat, the middle part of the base is supported on the column and can rotate up and down relative to the column through a first pin shaft, the middle part of the connecting rod is hinged at one end of the base through a second pin shaft and can rotate left and right relative to the base,

[0007] In order to allow the base to move up and down conveniently relative to the column, further, the column is provided with a connecting sleeve that can move up and down and rotate circumferentially relative to the column, and a positioning piece that can fix the connecting sleeve on the column is provided, and the middle part of the base is hinged to the connecting sleeve through the first pin shaft.

[0008] In the above-mentioned improved scheme, preferably, a plurality of first positioning holes radially penetrating therethrough are arranged at intervals from bottom to top on the column, a first positioning pin located below the connecting sleeve is inserted into the first positioning hole, and the first positioning pin and the first positioning hole form the positioning member.

[0009] In the above improved scheme, it is further improved that the base includes a first base and a second base connected to each other, the first base includes two relatively spaced arc-shaped arms for the connection sleeve to sit on and two connecting arms respectively connected between the opposite ends of the two arc-shaped arms, the second base is designed to be a U-shaped seat that is through from top to bottom and the mouth is facing away from the connecting arms, and the front and rear side walls of the U-shaped seat are correspondingly provided with second shaft holes for the second pin to be inserted. The two arc-shaped arms are preferably designed to be arc-shaped that bulges downward to make it easier to apply force.

[0010] In order to facilitate the position adjustment according to exhaust valves of different specifications, further, the two arc-shaped arms are respectively provided with a plurality of first axial holes which are arranged in sequence and correspond to each other along their respective length directions, and the first pin shaft is inserted in the corresponding first axial hole.

[0011] In order to prevent the connecting rod from tipping over too much, a groove with its mouth facing downward is opened on the wall surface of the U-shaped seat adjacent to the connecting arm, and corresponding limiting holes for inserting limiting pins are opened adjacent to the groove on the front and rear side walls.

[0012] In the above scheme, the connecting rod is provided with a plurality of second positioning holes which penetrate radially from bottom to top, and a second positioning pin which is used to abut against the valve cover on the exhaust valve is inserted into the second positioning hole, so as to conveniently adjust the height of the connecting rod relative to the base.

[0013] In order to realize the flexible movement of the movable seat, it is better that the four corners of the bottom of the movable seat are provided with movable wheels, and the base is provided with tracks for the corresponding side movable wheels to roll.

[0014] When necessary, the upper end of the connecting rod is also detachably connected to a receiving plate for connecting the air valve cover, and the receiving plate is provided with two mounting long holes corresponding to the bolts on the air valve cover.

[0015] In order to make it easier to hold and apply force, a vertical rod is provided at the other end of the base, a first handle is provided on the vertical rod, and a second handle is fixed to the lower end of the connecting rod.

[0016] Compared with the prior art, the utility model adds a movable seat with a column that can move horizontally relative to the base, and the middle part of the base is rotatably supported on the column, and the middle part of the connecting rod is hinged at one end of the base. In this way, the horizontal movement of the movable seat can be used to drive the base and the connecting rod to move to the desired position. At the same time, with the help of the lever principle that the base rotates up and down relative to the column and the connecting rod rotates left and right relative to one end of the base, the connecting rod can be driven to rotate effortlessly, and then the exhaust valve can be easily installed and disassembled. Therefore, the utility model does not require lifting equipment, can easily realize the movement of the connecting rod, and can allow the connecting rod to rotate accordingly, so that the connecting rod can be quickly raised and lowered and the exhaust valve can be installed and disassembled more effortlessly. Therefore, the utility model is more convenient to assemble and disassemble, and has a wider range of application occasions. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a three-dimensional schematic diagram of an embodiment of the utility model;

[0018] Figure 2 for Figure 1 Schematic diagram of the three-dimensional decomposition of

[0019] Figure 3 for Figure 1 Schematic diagram of another direction (the base is removed from the column);

[0020] Figure 4 This is a schematic diagram of the structure after a support plate is installed on the connecting rod of the utility model embodiment;

[0021] Figure 5 for Figure 4 Bottom view of the middle receiving plate (without the mounting bolts);

[0022] Figure 6It is a schematic diagram of the structure after the connecting rod in the embodiment of the utility model is connected with the exhaust valve. DETAILED DESCRIPTION

[0023] The present invention will be described in further detail below in conjunction with the accompanying drawings.

[0024] like Figures 1 to 3 As shown, the maintenance device is used for disassembling and assembling the exhaust valve in the reciprocating compressor, and it includes a base 1, a movable seat 2, a column 3, a base 4 and a connecting rod 5 for connecting the exhaust valve at the upper end, wherein the base 1 is designed as a square frame structure, and it includes two long frames 11 and two transverse frames 12, wherein the two long frames 11 are made of channel steel, and the mouths are laterally facing outward to form a track extending along the length direction, and the opposite surfaces of the two long frames are provided with a guide long hole 14 connected to the track 13, so as to reduce the weight of the entire base 1, and at the same time facilitate the installation of the movable seat 2 described below. The two transverse frames 12 are respectively fixed between the corresponding ends of the two long frames 11, and one of the transverse frames 12 is designed to be detachably connected to the long frames (bolted in the figure) to facilitate the installation of the movable seat 2 described below. Handles 15 are also provided on the two transverse frames 12 to facilitate transportation and holding.

[0025] The movable seat 2 is constrained on the base 1 and can move horizontally relative to the base 1. There are many ways for the movable seat 2 to slide, such as sliding on the base 1 in the form of a slide rail and a slider. In combination with the structure of the base 1, specifically, the movable seat 2 is provided with axles 21 at the four corners, and each axle is installed with a moving wheel 22 after passing through the long guide hole 14 on the base 1. The moving wheel 22 on the same side can slide in the corresponding side track of the base 1. In this way, the movable seat 2 can move freely along the track of the base 1 with the help of the four moving wheels 22. After installation, one of the horizontal frames is used to close the ends of the long guide hole 14 and the track 13 to prevent the movable seat 2 from leaving the base 1.

[0026] The above-mentioned column 3 is fixed upright on the movable seat 2. The column can be configured with multiple columns of different lengths. The column of appropriate length is selected and fixed on the movable seat 2 according to the needs. There are also multiple fixing methods. It is more convenient to design the column 3 into a tubular body with a screw hole at least at one end. The upper surface of the movable seat 2 is fixed with a first stud 23, and the lower end of the column 3 is fixed to the first stud 23 of the movable seat 2 by threaded connection. The column 3 is also sleeved with a connecting sleeve 6 that can move up and down and rotate circumferentially relative to the column, and a positioning member that can position the connecting sleeve 6 on the column 3 is also provided. In the figure, a plurality of first positioning holes 31 that penetrate radially are arranged from bottom to top at intervals on the column 3. The first positioning pin a1 located below the connecting sleeve 6 is inserted in the first positioning hole 31. The first positioning pin a1 and the first positioning hole 31 form the positioning member. In this way, the connecting sleeve 6 can be moved up and down or / and rotated circumferentially as needed, and the position of the connecting sleeve 6 relative to the movable seat 2 can be changed.

[0027] The above-mentioned base 4 is supported on the above-mentioned column 3. In order to allow the base 4 to rotate circumferentially and move up and down relative to the column 3, the middle part of the base 4 is hinged on the above-mentioned connecting sleeve 6 through the first pin shaft b1. Since the connecting sleeve 6 can rotate circumferentially relative to the column 3 and can move up and down by pulling out the first positioning pin a1, the base 4 can be connected to the connecting sleeve 6 through the first pin shaft b1 and can also rotate up and down and circumferentially relative to the column 3. In this way, the height of the base can be adjusted according to the height of cylinders of different specifications.

[0028] Furthermore, in order to ensure the smooth rotation of the base 4, the above-mentioned connecting rod 5 needs to be installed. In this embodiment, the base 4 includes a first base 41 and a second base 42. The first and second bases can be made into a split structure and connected into one by screws or welding. The first base 41 includes two relatively spaced arc arms 411 and two connecting arms 412 respectively connected between the opposite ends of the two arc arms. The two arc arms protrude downward, and the column 3 and the connecting sleeve 6 are located between the two arc arms 411. In order to facilitate the adjustment of the relative position of the column 3 and the two arc arms 411 in the horizontal direction, the two arc arms 411 are respectively provided with a plurality of first axial holes c1 which are arranged in sequence along their respective length directions and correspond to each other one by one. The above-mentioned first pin shaft b1 is inserted in the corresponding first axial hole c1. The second base 42 is located at the right end of the first base 41. It is designed to be a U-shaped base that penetrates from top to bottom and has its mouth facing away from the connecting arm. The front and rear side walls of the U-shaped base are correspondingly provided with second shaft holes c2 for inserting the second pin shaft b2.

[0029] The middle part of the connecting rod 5 is hinged to the second base 42 through the second pin shaft b2 and can rotate left and right relative to the second base 42. In order to allow the connecting rod 5 to have a larger activity space, a groove 421 with its mouth facing downward is opened on the wall surface of the second base 42 adjacent to the connecting arm 412. The front and rear side walls of the second base 42 are also correspondingly opened adjacent to the groove to allow the limiting pin 7 to be inserted. The limiting pin 7 can be used to abut against the rotating connecting rod 5 to prevent the connecting rod 5 from tipping over at an excessive angle.

[0030] Similarly, in order to facilitate the adjustment of the height of the connecting rod 5 relative to the base 4, a plurality of second positioning holes 51 are radially penetrated from bottom to top on the connecting rod 5. One of the plurality of second positioning holes (the second positioning hole at the lower part of the connecting rod 5) becomes a hinge hole in which the second pin shaft b2 is inserted, and two of the plurality of second positioning holes (the second positioning hole at the upper part of the connecting rod 5) is inserted with a second positioning pin a2, which is used to counteract the air valve cover on the exhaust valve described below.

[0031] The first positioning pin a1 and the second positioning pin a2 are preferably tapered pins to facilitate insertion and removal.

[0032] When disassembling the exhaust valve, the valve cover (not shown in the figure) needs to be disassembled first, so a receiving plate 8 is also configured, and the receiving plate 8 is disassembled and connected to the upper end of the connecting rod 5. Figure 4 and Figure 5 In the figure, a second stud 81 is provided in the middle of the receiving plate 8, and the connecting rod 5 is also designed as a tubular body, and the upper end is a screw structure, so that the second stud 81 can be threadedly connected to the upper end screw of the connecting rod 5, and at the same time, two long mounting holes 82 corresponding to the bolts on the air valve cover are opened on the receiving plate 8, and each long mounting hole is provided with a mounting bolt 83, which is used to penetrate into the screw hole of the air valve cover plate, and is used for anti-skid fixation of the air valve cover plate when it falls on the receiving plate 8 to prevent it from slipping, so as to remove it or install it.

[0033] In this embodiment, in order to facilitate the application of force, a vertical rod 43 is fixed to the left end of the above-mentioned first base 41, and a first handle 44 is provided on the vertical rod. A second handle 52 is fixed to the lower end of the connecting rod 5, so that the connecting rod 5 can be rotated when needed, and then the exhaust valve can be shaken conveniently after entering the valve hole, so that the exhaust valve can enter the valve hole seat during further lifting.

[0034] When the exhaust valve of a large reciprocating compressor needs to be inspected or replaced, the base 1 is placed at the corresponding position of the cylinder body where the exhaust valve needs to be disassembled and assembled, depending on whether the exhaust valve is 45° or 90° downward. The movable seat 2 can also be installed on the base 1 in advance and then placed at the corresponding position of the exhaust valve. Then, a column 3 of appropriate height is selected and threadedly connected to the first stud 23, and then a connecting sleeve 6 is installed on the column 3, and the connecting sleeve 6 is moved up or down to the required position, and then the first positioning pin a1 is inserted into the corresponding first positioning hole 31 of the column 3, so that the connecting sleeve 6 is fixed relative to the column 3 at the required height; then, according to the height of the exhaust valve and the valve cover to be repaired and the travel distance of sending the exhaust valve and the valve cover together into the cylinder body valve seat, the first shaft hole c1 at the appropriate position on the arc arm 41 is selected, and the first pin shaft b1 is inserted into the first shaft hole, so that the base is hinged to the connecting sleeve 6, so that the base can rotate up and down. When the first handle 44 is forced downward, the second base 42 is lifted; when the first handle 44 is forced upward, the second base 42 is lowered. Applying force horizontally to the first handle 44 allows the movable seat 2 to drive the column 3 and the base to move horizontally to a suitable position.

[0035] When the corresponding exhaust valve needs to be removed, first remove the circumferential fastening bolts on the valve cover of the cylinder body, remove the two bolts symmetrically (180°), then select the second positioning hole 51 at a suitable height on the connecting rod 5, insert the second pin shaft b2 into the second positioning hole 51 and the second shaft hole c2, so that the connecting rod 5 is hinged on the second base 42; then further insert the limit pin 7 into the limit hole of the second base 42 to limit the connecting rod 5 from tilting outwards on the second pin shaft b2. Then rotate the receiving plate 8, let the second stud on it screw into the screw hole at the upper end of the connecting rod 5, so that the receiving plate 8 is fixed to the upper end of the connecting rod 5, please refer to Figure 4 and Figure 5 . At this time, after removing two bolts symmetrically from the air valve cover plate, leave one nut and remove all the others. Adjust the movable seat, lift and press the first handle 44 to make corresponding movements on the installed receiving plate 8, slide the mounting bolts in the mounting long holes on the receiving plate 8, and insert them into the corresponding bolt holes of the air valve cover plate respectively, and then tighten the nuts on the mounting bolts to prevent the air valve cover plate from slipping on the receiving plate. After that, press down the first handle 44 to make the receiving plate 8 close to the air valve cover plate. Remove the last bolt on the air valve cover plate, pry off the air valve cover plate and let it fall onto the receiving plate 8. Lift the first handle 44 to make the receiving plate 8 hold the air valve cover plate away from the air valve hole, and then further move the air valve cover plate to a convenient position and then move it down through the first handle 44, the movable seat 2, the base and the connecting rod 5. When reinstalling the air valve cover plate, just reverse the sequence. During this process, the connecting rod 5 is rotated so that the connecting rod 5 can be pressed against the limiting pin 7 to prevent the connecting rod 5 from tilting outwards at an excessively large angle.

[0036] When the exhaust valve 100 and the valve cover 200 (the valve cover is pressed on the exhaust valve 100 by the step surface 201 thereon, and the exhaust valve 100 is pressed and fixed on the cylinder valve seat, the exhaust valve 100 is provided with a third stud 101, and the bottom of the valve cover 200 has a bayonet pin stuck on the step at the bottom of the cylinder valve hole) need to be removed from the cylinder valve hole, first let the connecting rod 5 slightly screw into the third stud 101 of the exhaust valve through the screw hole at its upper end, see Figure 6, then insert the second positioning pin a2 into the second positioning hole 51 of the connecting rod 5 adjacent to the bottom of the air valve cover, and continue to rotate the connecting rod 5 until the second positioning pin a2 abuts against the bottom of the air valve cover 200. At this time, the connecting rod 5, the exhaust valve 100 and the air valve cover 200 are fastened together. Push the first handle 44 downward or rotate it until the second axial hole c2 on the second base 42 is aligned with the second positioning hole 51 of the corresponding height on the connecting rod 5 installed on the exhaust valve, and then insert the second pin b2. At this time, the second base 42 and the connecting rod 5 are connected and installed. After that, pull out the pin stuck at the step of the cylinder body air valve hole at the bottom of the air valve cover 200. After the exhaust valve 100 and the air valve cover 200 fall from the air valve hole of the cylinder body, they are supported by the second positioning pin a2 and the second pin b2. Slowly lift the first handle 44 upwards to make the second base 42 rotate downward around the first pin b1. When the first handle is lifted upwards, the second pin b2 on the second base 42 will drive the connecting rod 5 on which the exhaust valve and the air valve cover are installed to move downwards. When the exhaust valve is about to escape from the air valve hole of the cylinder body, in order to prevent the connecting rod 5 from tipping over at a large angle in the second base 42, when the exhaust valve escapes from the air valve hole, slightly push, pull and shake the first handle, and then insert the limiting pin 7 into the limiting hole of the second base 42. Continue to lift the first handle 44 while slightly shaking until the exhaust valve completely escapes from the air valve hole of the cylinder body. Continue to pull the first handle 44 to make the movable seat 2 move backward in the track of the base 1 through the four moving wheels 22. Through a certain movement, the exhaust valve and the air valve cover are moved away from the cylinder body, and then the second pin b2 is pulled out, the connecting rod 5 is removed, and then the exhaust valve and the air valve cover are removed. The removal of a set of exhaust valves and air valve covers is completed. When the exhaust valve and the air valve cover are to be reinstalled, the exhaust valve, the air valve cover and the connecting rod 5 are fixed by reverse operation and then installed into the second base 42, and the second pin shaft b2 is inserted. Then the limit pin 7 is inserted into the limit hole, and the first handle 44 is pushed and shaken to align the exhaust valve with the cylinder air valve hole. After the exhaust valve is pushed into the orifice of the cylinder air valve hole during shaking, the limit pin 7 at the limit hole is pulled out to facilitate the exhaust valve to continue to be pushed into the exhaust valve and the air valve cover to enter the cylinder air valve hole after the first handle 44 is shaken and pressed downward. The angle change. When the air valve cover 200 is completely sent into the cylinder body air valve hole, due to the small circumferential clearance between the exhaust valve and the cylinder body air valve hole, another person is required to cooperate to slightly shake the second handle 52 at the bottom of the connecting rod 5, so that the exhaust valve is aligned with the cylinder body's air valve seat, and then the second handle 52 completes the final downward pressure to press the exhaust valve into the air valve seat, and then push the bayonet at the bottom of the air valve cover 200 into the step at the bottom of the cylinder body's air valve hole, and the exhaust valve and the air valve cover are fixed. Then pull out the second pin shaft b2 and unscrew the connecting rod 5. Then reinstall the exhaust valve cover plate as described above. In this way, a set of exhaust valves, air valve covers, and air valve cover plates are reinstalled.

Claims

1. A maintenance device for disassembling and assembling an exhaust valve of a reciprocating compressor, comprising a base (4) and a connecting rod (5) at the upper end for connecting the exhaust valve, characterized in that: It also includes a base (1) and a movable base (2) constrained on the base (1) and capable of horizontally moving relative to the base (1); a column (3) is erected on the movable base (2); the middle part of the base (4) is supported on the column (3) and can rotate up and down relative to the column (3) through a first pin shaft (b1); the middle part of the connecting rod (5) is hinged at one end of the base (4) through a second pin shaft (b2) and can rotate left and right relative to the base.

2. The maintenance device according to claim 1, characterized in that: The column (3) is provided with a connecting sleeve (6) which can move up and down and rotate circumferentially relative to the column (3), and is also provided with a positioning member which can fix the connecting sleeve (6) on the column (3). The middle part of the base (4) is hinged to the connecting sleeve (6) via the first pin shaft (b1).

3. The maintenance device according to claim 2, characterized in that: The column (3) is provided with a plurality of first positioning holes (31) radially penetrating therethrough at intervals from bottom to top, and a first positioning pin (a1) located below the connecting sleeve (6) is inserted into the first positioning hole (31), and the first positioning pin (a1) and the first positioning hole (31) form the positioning member.

4. The maintenance device according to claim 2, characterized in that: The base (4) includes a first base (41) and a second base (42) connected to each other. The first base (41) further includes two relatively spaced arc-shaped arms (411) for the connecting sleeve (6) to be seated, and two connecting arms (412) respectively connected between the opposite ends of the two arc-shaped arms. The second base (42) is designed to be a U-shaped seat that is through-through from top to bottom and with its mouth facing away from the connecting arms. The front and rear side walls of the U-shaped seat are correspondingly provided with second shaft holes (c2) for the second pin shaft (b2) to be inserted.

5. The maintenance device according to claim 4, characterized in that: The two arc-shaped arms (411) are respectively provided with a plurality of first axial holes (c1) which are arranged in sequence and spaced apart along their respective length directions and correspond to each other one by one, and the first pin shafts (b1) are inserted into the corresponding first axial holes (c1).

6. The maintenance device according to claim 4, characterized in that: A groove (421) with its mouth facing downward is formed on the wall surface of the U-shaped seat adjacent to the connecting arm, and correspondingly, a limiting hole (422) adjacent to the groove for inserting a limiting pin (7) is formed on the front and rear side walls.

7. The maintenance device according to any one of claims 1 to 6, characterized in that: The connecting rod (5) is provided with a plurality of second positioning holes (51) which penetrate radially from bottom to top at intervals, and a second positioning pin (a2) for abutting against a valve cover on the exhaust valve is inserted into the second positioning hole (51).

8. The maintenance device according to any one of claims 1 to 6, characterized in that: The four corners of the bottom of the movable seat (2) are provided with moving wheels (22), and the base (1) is provided with tracks (13) for the corresponding side moving wheels to roll.

9. The maintenance device according to any one of claims 1 to 6, characterized in that: The upper end of the connecting rod (5) is also detachably connected to a receiving plate (8) for connecting to the air valve cover, and the receiving plate (8) is provided with two mounting long holes (82) corresponding to the bolts on the air valve cover.

10. The maintenance device according to any one of claims 1 to 6, characterized in that: The other end of the base (4) is provided with a vertical rod (43), on which a first handle (44) is provided, and the lower end of the connecting rod (5) is fixed with a second handle (52).

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