A key bar type inflatable shaft maintenance device and an inflatable shaft maintenance method

Abstract

The present application relates to the technical field of air inflation shaft maintenance, in particular to a key strip type air inflation shaft maintenance device and method, comprising a workbench and a clamping assembly, the clamping assembly comprises a clamping support and a plurality of clamping strips installed along the circumference of the clamping support, the plurality of clamping strips form a clamping cavity capable of accommodating the air inflation shaft, each clamping strip is provided with a plurality of clamping units, the clamping units are used to lock the key strip when it protrudes from the surface of the air inflation shaft, and the clamping strips are linked with a cavity diameter adjusting structure for synchronously controlling the radial movement of all clamping strips. The present application has the beneficial effects of providing a key strip type air inflation shaft maintenance device and method, improving the efficiency and quality of air inflation shaft maintenance operation, and reducing the labor intensity and skill dependence of workers.

Description

Technical Field

[0001] This invention relates to the field of air shaft repair equipment technology, specifically to a key-bar type air shaft repair device and air shaft repair method. Background Technology

[0002] An air shaft, widely used in industries such as printing, packaging, papermaking, and textiles for fixing and transmitting roll materials, typically consists of a shaft, an air bladder, a key bar, and an elastic element that keeps the key bar in a normally contracted state. In operation, compressed air is injected into the air bladder, causing it to expand and push the key bar outwards, thus clamping the roll material fitted onto the shaft. When the air is released, the elastic element causes the key bar to retract to the shaft surface, facilitating the unloading of the roll material.

[0003] Chinese patent CN112936197B discloses a repair device for an air shaft, which includes a worktable, a first locking member, and a second locking member. The worktable is provided with a first base and a second base. A hydraulic cylinder is provided on the first base. The first locking member is coaxially disposed at the end of the piston rod of the hydraulic cylinder. The first locking member includes a first groove and a first locking head. The second locking member is coaxially disposed at the inflation end of the air shaft. The second locking member includes a second groove and a second locking head. A clamp for locking the first locking head and the second locking head is provided on the worktable. A first abutment is vertically disposed on the second base. The first abutment has an opening through which the air shaft passes. An annular groove is coaxially disposed at the end of the air shaft away from its inflation end. The opening of the annular groove extends out of the opening in the direction away from the first base and locks a second abutment for abutting against the first abutment. The second abutment has an arc-shaped groove that locks against the annular groove. This application facilitates the pulling out of the inflatable end; however, existing air shafts typically connect the key bar to a specialized elastic element, enabling the key bar to automatically retract into the shaft body. This results in the key bar retracting and jamming the air bladder after deflation during maintenance, making it difficult to remove the air bladder directly. (See attached...) Figure 1 As shown, the repair method for this problem usually involves first temporarily inflating the original airbag to make the key bar pop outwards. Then, a temporary fixing tool, such as an Allen wrench, is inserted into the maintenance hole on the air shaft key bar to fix the key bar in the extended position, preventing it from retracting during the removal of the airbag. Finally, the airbag is deflated and removed. This method requires limiting the key bar one by one, and the locking tool must be removed one by one after the repair is completed, making the operation cumbersome and time-consuming. Summary of the Invention

[0004] The present invention aims to provide a key bar type air shaft repair device and air shaft repair method, which is used to conveniently and quickly fix the key bar during the air shaft repair process and prevent it from retracting and hindering the repair work.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A key-bar type air shaft repair device includes a worktable. The worktable is sequentially equipped with a fixed shaft assembly for fixing one end of the air shaft, a clamping assembly for synchronously locking the keybar, a support assembly for supporting the other end of the air shaft, and an induction heating assembly for heating the shaft head position of the air shaft. The clamping assembly includes a clamping bracket fixed to the worktable and several clamping bars evenly distributed circumferentially along the clamping bracket. The clamping bars enclose a clamping cavity capable of accommodating the air shaft. Each clamping bar has several clamping units. Each clamping unit has a clamping portion for locking the keybar on the side facing the clamping cavity. A key alignment structure is linked between the clamping units on each clamping bar to adjust the position of the clamping units along the length of the clamping bar. Both ends of the clamping bar are linked with a cavity diameter adjustment structure to synchronously control the movement of all clamping bars along the radial direction of the clamping cavity.

[0006] The above technical solution utilizes circumferentially distributed clamping bars and their clamping units to form an integrated locking mechanism. When the air shaft inflates and extends the keybars, the device can lock all keybars simultaneously and at once through its clamping units, completely replacing the cumbersome process of using multiple additional clamps (such as Allen wrenches, custom pins, etc.) to temporarily fix each keybar individually in existing technologies. The cavity diameter adjustment structure allows the diameter of the clamping cavity to be adaptively adjusted according to the shaft dimensions of different air shaft specifications, improving the device's versatility. The fixed shaft assembly and support assembly provide excellent air shaft fixing conditions, while the induction heating assembly facilitates quick disassembly of the interference-fit shaft head. This device transforms the originally discrete, operator-experience-dependent temporary fixing operation into a centralized, standardized, and repeatable mechanical clamping process, shortening the keybar locking time before maintenance, reducing operational complexity, and quickly and conveniently facilitating the removal of internal components such as airbags.

[0007] The above technical solution can be further configured as follows: the clamping bar is provided with an elongated clamping groove for installing the clamping unit along its length direction, the inner wall of the clamping groove is provided with a guide groove along its length direction, and the side of the clamping unit is provided with a guide bar accordingly. The key alignment structure includes a key pitch adjustment unit for adjusting the distance between adjacent clamping units and a drive rod for driving the key pitch adjustment unit. The clamping bar has adjustment holes at both ends, and the two drive rods are threaded to the adjustment holes at both ends of the clamping bar. Both ends of the key pitch adjustment unit are hinged with linkage components, and the end of the linkage component away from the key pitch adjustment unit is rotatably connected to the end of the drive rod near the key pitch adjustment unit.

[0008] The end of the drive rod away from the key pitch adjustment unit is provided with a wing nut for driving the drive rod to rotate.

[0009] The above technical solution utilizes the cooperation of the elongated clamping groove, guide groove, and guide bar to provide a precise linear movement track for the clamping unit, ensuring smooth and unbiased movement during adjustment. The key alignment structure achieves synchronous adjustment of the spacing between all clamping units on the same clamping bar through mechanical linkage. The working principle of this technical solution is as follows: When the wing nut at one end is tightened, the drive rod rotates. Due to the threaded connection between the drive rod and the adjustment hole at the end of the clamping bar, the drive rod generates axial displacement during rotation. This axial displacement of the drive rod pushes or pulls the key pitch adjustment unit through the linkage, which in turn drives all the clamping units connected to it to move synchronously along the clamping groove. This positions the clamping unit at one end at the outermost key bar of a certain column, using this as a positioning reference. The drive rod on the other side is then adjusted to adjust the spacing between the clamping units, ensuring that the center distance between the clamping units on the same clamping bar matches the center distance of the key bars on the air shaft. Using this technical solution, the operator does not need to manually check the position of each clamping unit one by one. Simply rotating the drive rod can quickly match the spacing of the entire row of clamping units to the actual distribution pitch of the key strip on the air shaft to be repaired, thus improving alignment efficiency.

[0010] The above technical solution can be further configured as follows: the cavity diameter adjustment structure includes a guide disk detachably fixed to the clamping bracket and an adjustment disk coaxially arranged with the guide disk. The guide disk has a plurality of radially arranged guide waist holes distributed along the circumference. The adjustment disk has a plurality of spirally diverging cavity diameter adjustment waist holes evenly distributed along the circumference corresponding to the guide waist holes. The side of the adjustment disk is provided with a toggle part that can drive the adjustment disk to rotate. The end of the drive rod away from the key pitch adjustment unit passes through the cavity diameter adjustment waist hole and the guide waist hole in sequence.

[0011] Using the above technical solution, the cavity diameter adjustment structure employs a mechanical amplification principle with dual-disc cooperation, achieving synchronous radial movement of multiple clamping bars controlled by a single operating point. The guide disc is fixed, and its radial guide holes provide a constraint trajectory for the radial sliding of each drive rod. The adjustment disc is rotatable, and its cavity diameter adjustment holes are spirally diverging, with each hole considered as a variable-diameter curved slide. When the adjustment disc is rotated via the actuating part, the spiral cavity diameter adjustment holes will circumferentially offset relative to the fixed radial guide holes, forcing the drive rods passing between them to generate radial displacement along the radial guide holes. Since the ends of all drive rods pass through the corresponding spiral holes in the same manner, the single rotational motion of the adjustment disc is synchronously converted into radial linear motion of all drive rod ends, thereby driving all clamping bars to perform synchronous, equidistant radial opening and closing through the drive rods. This structure ensures that the clamping cavities remain concentric circles during adjustment, enabling rapid and accurate adaptation to air shafts of different diameters, and the adjustment process is smooth and easy to control.

[0012] The above technical solution can be further configured as follows: the key pitch adjustment unit includes several scissor base units, each scissor base unit is composed of two long connecting rods that are cross-hinged in the middle, the end hinge points of adjacent scissor base units are connected in series, the end hinge point of the previous scissor base unit is hinged to the beginning hinge point of the next scissor base unit to form a continuous scissor structure, the outer ends of the two outermost scissor base units are respectively hinged to four short connecting rods, and the outer ends of the two short connecting rods at each end are hinged to each other; each clamping unit is provided with a mounting groove for mounting the key pitch adjustment unit, the mounting groove is provided with a pin hole, a pin is installed in the pin hole, and the middle hinge point of each scissor base unit is hinged to a pin.

[0013] Using the above technical solution, the key pitch adjustment unit employs a scissor-type linkage mechanism, transforming the axial displacement provided by the drive rod into variations in the spacing of multiple clamping units. Its working principle is as follows: The drive rod pushes or pulls the outermost short connecting rod through a linkage component. The opening and closing motion of the short connecting rod is transmitted to the end of the scissor base unit hinged to it, forcing the middle hinge point of the scissor base unit (i.e., the point fixedly connected to the clamping unit) to displace. Since all scissor base units are connected in series through their end hinge points, and their middle hinge points are respectively fixed to each clamping unit, the movement of one scissor base unit is continuously transmitted to the entire linkage system, driving all clamping units to move synchronously, achieving precise and linear adjustment of the clamping unit spacing. Simultaneously, all connections are hinged, resulting in low friction between moving parts, smooth adjustment, and low wear.

[0014] The above technical solution can be further configured as follows: the induction heating assembly includes a frequency converter, an induction coil, and a coil base. The coil base is detachably mounted on one end of the workbench. The coil base includes a coil base and a rotating component rotatably connected to the coil base. The induction coil is mounted on the rotating component and can rotate with the rotating component. A rotation limiting structure is provided between the rotating component and the coil base. The frequency converter is mounted on the workbench and the induction coil is electrically connected to the frequency converter. The rotation limiting structure includes a limiting groove provided on the coil base and a limiting protrusion provided on the rotating component corresponding to the limiting groove. A limiting spring is provided between the rotating component and the coil base. The limiting spring provides a preload force to push the limiting protrusion towards the limiting groove. One end of the limiting spring abuts against the rotating component, and the other end of the limiting spring abuts against the coil base.

[0015] The above technical solution utilizes the principle of electromagnetic induction to generate eddy currents at the end of the bushing, causing it to heat up and expand. This is a non-contact internal heat source heating method, offering high thermal efficiency and uniform heating. The heat is concentrated on the area where the shaft head needs to be disassembled, minimizing thermal impact on other parts of the shaft (such as the air bladder). This avoids problems such as uneven heat distribution and easy blackening of the workpiece surface that can occur with traditional methods like flame heating. The rotatable design of the coil holder allows the induction coil to be folded and stored when heating is not needed, without affecting the installation, disassembly, and maintenance of the air shaft. The rotation limiting structure, through the cooperation of a limiting groove and a limiting protrusion, and the preload provided by a limiting spring, ensures that the limiting protrusion is stably locked in a limiting groove. This achieves self-locking of the rotating part in both the working and stored states, preventing coil displacement due to vibration or other factors during heating and improving heating stability.

[0016] The above technical solution can be further configured as follows: the fixed-axis assembly includes a fixed-axis seat mounted on the worktable and a fixed-axis chuck fixedly mounted on the fixed-axis seat. The fixed-axis chuck includes a chuck body and an end cap detachably fixed to one end of the chuck body. The chuck body has a central through hole, and a receiving cavity is formed between the end cap and the chuck body. The inner wall of the receiving cavity is circumferentially distributed with several radial guide grooves. Each radial guide groove is equipped with a fixed-axis claw. A wire spool is rotatably mounted in the receiving cavity. The side of the wire spool away from the end cap has an integrally formed first annular boss. The chuck body has a second annular boss corresponding to the first annular boss. A ring-shaped boss is rotatably fitted onto the outside of a second ring-shaped boss. A spiral guide strip is provided on the side of the spool facing the end cover. An arc-shaped guide groove is provided on the end of the fixed-axis claw facing the spool corresponding to the spiral guide strip. When the spool is rotated, the fixed-axis claw can move synchronously radially along the radial guide groove. The chuck body has a mounting hole that communicates with the receiving cavity in the radial direction. A bevel gear is rotatably mounted in the mounting hole through a rolling bearing. An interface groove is provided on the end of the bevel gear facing the outside of the chuck body. A face tooth that meshes with the bevel gear is provided on the end of the spool facing the first ring-shaped boss. A chuck wrench is detachably mounted on the interface groove. Rotating the chuck wrench can drive the bevel gear to rotate.

[0017] Using the above technical solution, the fixed-axis assembly provides a stable, reliable, and automatically centering clamping solution for the air shaft during maintenance. Multiple fixed-axis jaws slide within the radial guide grooves of the receiving cavity, their radial movement driven by the helical guide strip on the end face of the screw spool. When the external chuck wrench is inserted into the interface groove of the bevel gear and rotated, the bevel gear drives the teeth on the end face of the screw spool, causing the screw spool to rotate. As the screw spool rotates, the helical guide strip on its end face acts on the arc-shaped guide groove at the bottom of the fixed-axis jaws, converting the rotational motion of the screw spool into synchronous, equidistant linear motion of all the fixed-axis jaws along the radial guide grooves, thereby achieving clamping or releasing. The sleeve engagement of the first and second annular bosses provides rotational support for the screw spool and ensures that its rotational axis coincides with the central axis of the chuck, achieving high-precision centering clamping. The end cover encloses the transmission components, providing dust protection. This assembly achieves multi-point synchronous clamping through pure mechanical linkage, resulting in high clamping force, good centering, and effortless operation.

[0018] The above technical solution can be further configured as follows: a fixed-axis moving structure is provided between the fixed-axis seat and the worktable. The fixed-axis moving structure includes a moving groove provided on the worktable for installing the fixed-axis seat. Moving guide grooves are provided on both sides of the moving groove. Moving guide strips are provided on both sides of the fixed-axis seat corresponding to the moving guide grooves. A moving screw is provided on the fixed-axis seat. One end of the moving screw is rotatably connected to the end side wall of the moving groove through a bearing. A rotating handle is fixedly connected to the end of the moving screw away from the worktable. Turning the rotating handle can drive the moving screw to rotate.

[0019] By adopting the above technical solution, the fixed-axis moving structure endows the fixed-axis assembly with the ability to adjust its position along the axial direction of the air shaft, improving the device's adaptability to air shafts of different lengths. The moving groove and the moving guide bar form a precise long linear guide pair, ensuring smooth, wobbly movement of the fixed-axis seat with high directional accuracy. The moving screw, as the core of the transmission, converts the rotational motion input by the handle into precise linear displacement of the fixed-axis seat along the moving groove. The screw drive has a self-locking characteristic; once adjusted to the correct position, the position of the fixed-axis seat will not shift due to the weight of the air shaft or the reaction force of the operation during subsequent maintenance, ensuring stable clamping. This structure optimizes the operation process when clamping air shafts of different lengths: the air shaft can be inserted into the clamping cavity first, and then the axial position of the entire fixed-axis assembly (including the fixed-axis chuck) can be adjusted by turning the handle, so that the fixed-axis chuck is accurately aligned with the suitable clamping part on the air shaft, and then locked, improving the device's versatility and ease of operation.

[0020] The above technical solution can be further configured as follows: the support component includes a V-shaped support block, a support base for mounting the V-shaped support block, a lifting screw with one end threadedly connected to the V-shaped support block, and a lifting motor for driving the lifting screw to rotate. The support base is provided with a support guide groove, and the V-shaped support block is slidably mounted in the support guide groove. The bottom of the support base is provided with a screw hole, and the lifting screw passes through the screw hole. The end of the lifting screw away from the V-shaped support block is connected to the output shaft of the lifting motor. The output shaft of the lifting motor drives the lifting screw to rotate, thereby driving the V-shaped support block to move up and down in the support guide groove.

[0021] Using the above technical solution, the support assembly and the fixed-axis assembly work together to achieve horizontal positioning and stable support of the air shaft. The V-shaped support block naturally adapts to the cylindrical shaft, providing two-point contact and a certain degree of self-centering, while also offering better contact stress distribution. The support guide groove strictly constrains the V-shaped support block to only perform linear motion in the vertical direction, ensuring the accuracy of the lifting trajectory. The combination of the lifting screw and the lifting motor enables electric automated adjustment of the support height. The working principle of this technical solution is as follows: When the lifting motor starts, its output shaft directly drives the lifting screw to rotate. Since the V-shaped support block is connected to the lifting screw via threads, and its horizontal rotational freedom is restricted by the support guide groove, the rotational motion of the lifting screw is converted into the vertical lifting motion of the V-shaped support block along the guide groove. By controlling the forward and reverse rotation of the motor, the height of the V-shaped support block can be precisely and quickly adjusted, thereby adjusting the air shaft placed between it and the fixed-axis chuck to a horizontal state. Automated adjustment is more convenient and faster than manual adjustment, improving the efficiency of maintenance operations.

[0022] A method for repairing an air shaft, using the aforementioned key-bar type air shaft repair device, includes the following steps: S1: Adjust the operating cavity diameter according to the shaft diameter of the air shaft to be repaired, so that the clamping bar slides radially synchronously, and adjust the clamping cavity to the size that can accommodate the air shaft.

[0023] S2: Pass the air shaft to be repaired through the clamping cavity, fix one end of it through the fixed shaft assembly, and support the other end through the support assembly.

[0024] S3: Adjust the key alignment structure so that each clamping unit of each assembly clamping unit is aligned with the key bar position on the air expansion shaft in the axial direction.

[0025] S4: Inflate the air shaft to make the key bar extend out of the surface, operate the cavity diameter adjustment structure to shrink the clamping cavity shaft diameter, so that each clamping unit is aligned with the key bar position on the air shaft in the radial direction.

[0026] S5: Release the fixed shaft assembly from fixing the air shaft, rotate the air shaft so that the clamping part of each clamping unit is inserted into the corresponding hole on the key bar and re-fix the air shaft.

[0027] S6: Activate the induction heating component to heat the air shaft head to the preset temperature, remove the shaft head and air bladder, and then proceed with subsequent maintenance operations.

[0028] S7: After the repair is completed, heat and install the air bag and shaft head. After the air shaft head cools down and the shaft head is tightly connected to the air shaft body, release the fixation of the air shaft, inflate the air bag and rotate the air shaft in the opposite direction to make the key strip disengage from the clamping part, expand the clamping cavity size, take out the repaired air shaft, and complete the repair.

[0029] By adopting the above technical solution, all functions of the aforementioned device are integrated in an orderly manner to form a standardized operating procedure. Steps S1, S2, S3, and S4 respectively solve the problems of shaft diameter adaptation, shaft fixing, axial clamping pre-alignment, and radial clamping pre-alignment. Step S5 completes the synchronous clamping of all key bars. Step S6 uses an induction heating component to heat the shaft end for a period of time or at a certain set temperature, causing the shaft end to expand due to heat, making the disassembly of the interference fit shaft head easier. Step S7 completes the reset and shaft removal process after maintenance. This method shortens the time required for a single maintenance, improves labor efficiency, and reduces labor intensity. It should be noted that the initial clamping unit position and the set key spacing after shaft removal do not need to be adjusted. Directly installing the same type of air-expanded shaft and performing the remaining steps and maintenance work can further reduce the time required for batch maintenance and improve batch maintenance efficiency. It should be added that the front end of the clamping part is provided with rounded corners. When there is a slight alignment error between the clamping part and the maintenance hole, the hemispherical guide head formed by the rounded corners can automatically correct the clamping part to eliminate the slight alignment error and reduce the alignment accuracy requirements between the clamping part and the maintenance hole.

[0030] The present invention has at least the following beneficial effects: Through the synergistic action of the clamping assembly and the cavity diameter adjustment structure, the keybars of the air shaft can be quickly and synchronously locked, replacing the tedious operation of fixing each keybar individually in the traditional method, thus improving maintenance efficiency. Together with the fixed shaft assembly, induction heating assembly and support assembly, an integrated maintenance system is formed, which reduces the reliance on the operator's skills, reduces labor intensity, and enhances the adaptability of the device to air shafts of different specifications and the consistency of maintenance quality.

[0031] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. Attached Figure Description

[0032] Figure 1 Schematic diagram of the keyway locking method for air shaft; Figure 2 This is a schematic diagram of the overall structure of Example 1; Figure 3 This is a schematic diagram of the overall structure of the clamping assembly in Example 1; Figure 4 Here are the structural diagram and sectional view of the clamping unit after assembly in Example 1; Figure 5 This is a schematic diagram of the induction heating component structure in Example 1; Figure 6 This is a cross-sectional view of the induction heating assembly in Example 1; Figure 7 This is a schematic diagram of the fixed-axis assembly structure in Example 1; Figure 8 This is a schematic diagram of the support component structure for Example 1; Figure 9 This is a schematic diagram showing the clamping part aligned but not clamped. Figure 10 This is a schematic diagram showing the clamping state of the key bar in the clamping section; Labeling notes: Workbench 1, Clamping assembly 2, Clamping bracket 21, Clamping bar 22, Clamping cavity 20, Clamping groove 221, Guide groove 222, Clamping unit 23, Guide bar 231, Clamping part 232, Mounting groove 233, Key alignment structure 24, Drive rod 241, Wing nut 242, Key pitch adjustment unit 243, Scissor lift base unit 2431, Long connecting rod 2432, Short connecting rod 2433, Adjusting hole 223, Linkage component 244, Cavity diameter adjustment structure 25, Guide plate 251, Guide waist hole 2511, Adjusting plate 252, Cavity diameter adjustment waist hole 2521, Actuating part 2522, Fixed axis assembly 3, Fixed axis seat 31, Moving guide bar 311, Fixed axis moving structure 32, Moving groove 321, Moving guide groove 322, Moving lead screw 323, Rotary... The components include: handle 324, fixed-axis chuck 33, chuck body 331, center through hole 3311, second annular boss 3312, mounting hole 3313, end cover 332, accommodating cavity 333, radial guide groove 334, fixed-axis claw 335, arc-shaped guide groove 3351, screw spool 336, first annular boss 3361, spiral guide bar 3362, face tooth 3363, bevel gear 337, interface groove 3371, induction heating assembly 4, frequency converter 41, coil seat 42, coil base 421, rotating component 422, induction coil 43, rotation limit structure 44, limit groove 441, limit protrusion 442, limit spring 443, support assembly 5, support seat 51, support guide groove 511, V-shaped support block 52, lifting screw 53, and lifting motor 54. Detailed Implementation

[0033] The technical solutions in the embodiments of the present invention will be clearly and completely described below. 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.

[0034] A keybar-type air shaft repair device includes a worktable 1, a clamping assembly 2, a fixed shaft assembly 3, an induction heating assembly 4, and a support assembly 5. The worktable 1 serves as the mounting base for the entire device, providing support for the other components. The clamping assembly 2, used to clamp the keybar and prevent its retraction, includes a clamping bracket 21 fixedly mounted on the worktable 1. Along the circumference of the clamping bracket 21, clamping bars 22, matching the number of columns of the air shaft keybar, are evenly distributed. All clamping bars 22 together form a clamping cavity 20 capable of accommodating the air shaft, the diameter of which is adjustable. Each clamping bar 22 has an elongated clamping groove 221 along its length, and the inner wall of the clamping groove 221 has a guide groove 222. Multiple clamping units 23, capable of sliding along the guide groove 222, are installed within the clamping groove 221. Each clamping unit 23 has a guide bar 231 on its side that mates with the guide groove 222. These clamping units 23 have clamping portions 232 on the side facing the clamping cavity 20 for locking the key bars on the air shaft. To ensure that all clamping units 23 on the same clamping bar 22 can precisely match the distribution position of the key bars on the air shaft, they are linked together by a key alignment structure 24. This key alignment structure 24 includes a drive rod 241, a wing nut 242, and a key pitch adjustment unit 243 composed of multiple scissor base units 2431 connected in series. Each scissor base unit 2431 is formed by two long connecting rods 2432 hinged at the middle. Each end of the long connecting rod 2432 of the key pitch adjustment unit 243 is connected to a short connecting rod 2433, and the ends of the two short connecting rods 2433 on the same side are hinged together. Each clamping unit 23 has a mounting groove 233, in which a scissor base unit 2431 is mounted via a pin, thereby connecting all clamping units 23 to the key pitch adjustment unit 243. There are two drive rods 241, which are threaded into the adjustment holes 223 at both ends of the clamping bar 22. One end of each drive rod 241 near the key pitch adjustment unit 243 is hinged to the outermost short connecting rod 2433 of the key alignment structure 24 via a linkage 244, and the other end passes through the cavity diameter adjustment structure 25 and is fitted with a wing nut 242. The wing nut 242 and the drive rod 241 can be selectively engaged or disengaged via a keyway. The drive rod 241 has a longer threaded section, a smooth section, and a shorter threaded section in sequence. The smooth section is provided with a keyway in which a flat key is installed, and the wing nut 242 is provided with a corresponding flat key. Regarding the groove, it is important to note that the length of the section of the smooth rod without the keyway is greater than the length of the wing nut 242 on the shaft. This is to prevent the short threaded section from obstructing the key and groove fit. The wing nut 242 is screwed in from the shorter threaded section, and after it is fully inserted into the smooth rod section, it is pushed to fit with the flat key. At this time, turning the wing nut 242 can drive the drive rod 241 to rotate and generate axial displacement, which in turn pushes or pulls the entire key pitch adjustment unit 243 through the linkage 244, so as to achieve synchronous and precise adjustment of the spacing of all clamping units 23.

[0035] To accommodate air shafts of different diameters, the radial movement of all clamping bars 22 is synchronously controlled by a cavity diameter adjustment structure 25. This cavity diameter adjustment structure 25 includes a guide plate 251 detachably fixed to the clamping bracket 21, and an adjustment plate 252 coaxially arranged with the guide plate 251. The guide plate 251 has a plurality of radially extending guide holes 2511 distributed circumferentially. The adjustment plate 252 has the same number of spirally diverging cavity diameter adjustment holes 2521 circumferentially. The side of the adjustment plate 252 has a conveniently operated actuating part 2522. The end of the drive rod 241 of each clamping bar 22 passes sequentially through the corresponding cavity diameter adjustment hole 2521 and guide hole 2511. Its working principle is as follows: rotating the actuating part 2522 drives the adjusting plate 252 to rotate, and the spiral cavity diameter adjusting waist hole 2521 forces the passing drive rod 241 to move synchronously inward or outward along the radial guide waist hole 2511, thereby driving all clamping bars 22 to open and close synchronously in the radial direction, and quickly adjusting the diameter of the clamping cavity 20. The fixed axis assembly 3 is set on one side of the clamping assembly 2 and is used to fix one end of the air shaft. The assembly includes a fixed axis seat 31, which is mounted on the worktable 1 through a fixed axis moving structure 32. The fixed axis moving structure 32 includes a moving groove 321 opened on the worktable 1, and moving guide grooves 322 on both sides of the moving groove 321. Moving guide bars 311 are provided on both sides of the fixed axis seat 31 to cooperate with it, so that the fixed axis seat 31 can slide stably along the moving groove 321. A moving screw 323 is installed in the moving groove 321, one end of which is connected to the groove wall through a bearing, and the other end is fixedly connected to a rotating handle 324. Turning the handle 324 drives the movable lead screw 323 to rotate, thereby causing the fixed shaft seat 31 to move axially to accommodate air shafts of different lengths. A fixed shaft chuck 33 is fixedly mounted on the fixed shaft seat 31. The fixed shaft chuck 33 includes a chuck body 331 and an end cap 332 fixed to one end by bolts. The chuck body 331 has a central through hole 3311, which forms a receiving cavity 333 with the end cap 332. Multiple radial guide grooves 334 are evenly distributed circumferentially on the inner wall of the receiving cavity 333, and a fixed shaft claw 335 is slidably installed in each groove. A rotatable lead screw 336 is also installed in the receiving cavity 333. The spool 336 has an integral first annular boss 3361 on the side facing away from the end cover 332, and a corresponding second annular boss 3312 on the chuck body 331. The first annular boss 3361 is rotatably fitted onto the outside of the second annular boss 3312, providing rotational support for the spool 336. A spiral guide bar 3362 is provided on the side of the spool 336 facing the end cover 332, and an arc-shaped guide groove 3351 is provided at the corresponding end of the fixed-axis claw 335 to engage with it. A mounting hole 3313 is radially opened on the chuck body 331, through which a bevel gear 337 is mounted via a rolling bearing. The outer end of the bevel gear 337 has an interface groove 3371. The end face of the spool 336 facing the first annular boss 3361 has teeth 3363 that mesh with the bevel gear 337.Its working principle is as follows: the chuck wrench is inserted into the interface slot 3371 and rotated, which drives the bevel gear 337 to rotate, thereby driving the screw spool 336 to rotate. The spiral guide bar 3362 of the screw spool 336 acts on the arc-shaped guide groove 3351 of the fixed shaft jaw 335, converting the rotational motion into synchronous radial movement of all fixed shaft jaws 335 along the radial guide groove 334, thereby achieving clamping or releasing of the air shaft.

[0036] The induction heating assembly 4 is used to heat the end of the air shaft when disassembling the air shaft head. It includes a frequency converter power supply 41 mounted on the workbench 1, and an induction coil 43 mounted on one end of the workbench 1 via a coil holder 42. The coil holder 42 includes a coil base 421 and a rotating component 422 rotatably connected thereto. The induction coil 43 is mounted on the rotating component 422. A rotation limiting structure 44 is provided between the rotating component 422 and the coil base 421. This structure includes a limiting groove 441 on the coil base 421, a limiting protrusion 442 on the rotating component 422, and a limiting spring 443 providing preload. Figure 5 As shown, there are two limiting grooves 441, one located at the top working position and the other at the left storage position. The two ends of the limiting spring 443 abut against the rotating part 422 and the coil base 421 respectively, pressing the limiting protrusion 442 into the limiting groove 441 to achieve self-locking. When heating is required, the rotating part 422 is rotated to the working position so that the coil is coaxial with the air shaft for the air shaft to pass through; when not in use, it can be rotated and stored to avoid interfering with the assembly and disassembly of the air shaft.

[0037] The support assembly 5 is located on the other side of the clamping assembly 2 and is used to support the other end of the air shaft. It includes a support base 51 with a vertical support guide groove 511. A V-shaped support block 52 is slidably mounted in the support guide groove 511. A lead screw hole is opened at the bottom of the support base 51, through which a lifting lead screw 53 passes and is threadedly connected to the V-shaped support block 52. The bottom end of the lifting lead screw 53 is connected to the output shaft of the lifting motor 54. When the lifting motor 54 is started, its output shaft drives the lifting lead screw 53 to rotate, thereby causing the V-shaped support block 52 to move up and down along the support guide groove 511 to adjust the air shaft to a horizontal state.

[0038] The working principle of this embodiment is as follows: First, based on the diameter of the air shaft to be repaired, rotate the actuating part 2522 of the cavity diameter adjustment structure 25 to rotate the adjustment plate 252, driving all clamping bars 22 to move radially synchronously, adjusting the clamping cavity 20 to the appropriate size. Next, pass one end of the air shaft through the center through hole 3311 of the fixed shaft chuck 33, the clamping cavity 20, and the induction coil 43 in sequence, and place the shaft on the V-shaped support block 52. Then, turn the rotating handle 324 to adjust the position of the fixed shaft seat 31, so that the fixed shaft chuck 33 is aligned with the appropriate clamping part of the air shaft. Then, use the chuck wrench to drive the bevel gear 337, so that the fixed shaft jaw 335 retracts to clamp the air shaft. Start the lifting motor 54 and adjust the height of the V-shaped support block 52 to make the air shaft horizontal. After that, turn the wing nuts 242 at both ends of the clamping bars 22, and adjust the spacing of each clamping unit 23 through the key spacing adjustment unit 243 to make it correspond one-to-one with the position of the key bar on the air shaft. After preparation, inflate the air shaft to extend the key bar, and rotate the actuating part 2522 in the reverse direction to close the clamping bar 22, aligning the clamping part 232 with the service hole of the key bar (e.g., Figure 9 (As shown), then slightly loosen the fixed shaft jaw 335, and gently rotate the air shaft so that the clamping part 232 of each clamping unit 23 is accurately inserted into the maintenance hole of the corresponding key bar (as shown). Figure 10 As shown in the diagram, it should be noted that, to facilitate the insertion of all clamping parts 232 into the maintenance holes in a single rotation, the front end of the clamping part 232 is rounded to reduce the alignment accuracy requirements between the clamping part 232 and the maintenance hole. Then, the fixed shaft jaw 335 is re-locked. At this point, all key bars are mechanically locked in the extended position. Subsequently, the frequency converter power supply 41 is activated for heating. Once the shaft end expands due to heat, the shaft head and air bladder can be easily removed for maintenance. After maintenance, the air bladder and shaft head are installed on the heated shaft end. After cooling, the locking mechanisms are released, and the air-expanded shaft can be removed to complete the maintenance.

[0039] The above-described embodiments are merely one implementation of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention.

Claims

1. A key-bar type air shaft repair device, comprising a worktable, characterized in that: The worktable is sequentially equipped with a fixed shaft assembly for fixing one end of the air shaft, a clamping assembly for synchronously locking the key bar, a support assembly for supporting the other end of the air shaft, and an induction heating assembly for heating the shaft head of the air shaft. The clamping assembly includes a clamping bracket fixed to the worktable and several clamping bars evenly distributed along the circumference of the clamping bracket. The several clamping bars enclose a clamping cavity that can accommodate the air shaft. Each clamping bar is provided with several clamping units. Each clamping unit has a clamping part for locking the key bar on the side facing the clamping cavity. The several clamping units on each clamping bar are linked together by a key that adjusts the position of the clamping unit in the length direction of the clamping bar. The alignment structure includes a cavity diameter adjustment structure at both ends of the clamping bar, which synchronously controls the movement of all clamping bars along the radial direction of the clamping cavity; the clamping bar has an elongated clamping groove along its length for mounting clamping units, and the inner wall of the clamping groove has a guide groove along its length, with guide bars correspondingly provided on the side of the clamping unit; the key alignment structure includes a key pitch adjustment unit for adjusting the distance between adjacent clamping units, and a drive rod for driving the key pitch adjustment unit; the clamping bar has adjustment holes at both ends, and the two drive rods are threadedly connected to the adjustment holes at both ends of the clamping bar; both ends of the key pitch adjustment unit are hinged with linkage components, and the linkage components... The end of the drive rod away from the key pitch adjustment unit is rotatably connected to the end of the drive rod near the key pitch adjustment unit; the end of the drive rod away from the key pitch adjustment unit is provided with a wing nut for driving the drive rod to rotate; the cavity diameter adjustment structure includes a guide plate detachably fixed to the clamping bracket and an adjustment plate coaxially arranged with the guide plate. The guide plate has several radially arranged guide holes distributed along the circumference, and the adjustment plate has several spirally diverging cavity diameter adjustment holes evenly distributed along the circumference corresponding to the guide holes. The side of the adjustment plate is provided with a toggle part that can drive the adjustment plate to rotate. The end of the drive rod away from the key pitch adjustment unit passes through the cavity diameter adjustment holes in sequence. The key pitch adjustment unit includes several scissor base units. Each scissor base unit consists of two long connecting rods that are hinged together at the middle. The end hinge points of adjacent scissor base units are connected in series. The end hinge point of the previous scissor base unit is hinged to the beginning hinge point of the next scissor base unit to form a continuous scissor structure. The outer ends of the two outermost scissor base units are respectively hinged to four short connecting rods. The outer ends of the two short connecting rods at each end are hinged to each other. Each clamping unit is provided with a mounting groove for mounting the key pitch adjustment unit. The mounting groove is provided with a pin hole. A pin is installed in the pin hole. The middle hinge point of each scissor base unit is hinged to a pin.

2. The key-bar type air shaft repair device according to claim 1, characterized in that: The induction heating assembly includes a frequency converter, an induction coil, and a coil base. The coil base is detachably mounted on one end of the workbench. The coil base includes a coil base and a rotating component rotatably connected to the coil base. The induction coil is mounted on the rotating component and can rotate with the rotating component. A rotation limiting structure is provided between the rotating component and the coil base. The frequency converter is mounted on the workbench and the induction coil is electrically connected to the frequency converter. The rotation limiting structure includes a limiting groove on the coil base and a limiting protrusion on the rotating component corresponding to the limiting groove. A limiting spring is provided between the rotating component and the coil base. The limiting spring provides a preload force to push the limiting protrusion into the limiting groove. One end of the limiting spring abuts against the rotating component, and the other end of the limiting spring abuts against the coil base.

3. The key-bar type air shaft repair device according to claim 1, characterized in that: The fixed-axis assembly includes a fixed-axis seat mounted on a worktable and a fixed-axis chuck fixedly mounted on the fixed-axis seat. The fixed-axis chuck includes a chuck body and an end cap detachably fixed to one end of the chuck body. The chuck body has a central through hole, and a receiving cavity is formed between the end cap and the chuck body. The inner wall of the receiving cavity has several radially distributed guide grooves, and each radially guide groove is equipped with a fixed-axis claw. A wire spool is rotatably mounted in the receiving cavity. The wire spool has an integrally formed first annular boss on the side away from the end cap. The chuck body has a second annular boss corresponding to the first annular boss. The first annular boss is rotatable. The movable sleeve is located outside the second annular boss. The side of the spool facing the end cover is provided with a spiral guide strip. The fixed-axis claw is provided with an arc-shaped guide groove corresponding to the spiral guide strip at the end facing the spool. When the spool is rotated, the fixed-axis claw can move synchronously radially along the radial guide groove. The chuck body is provided with a mounting hole that communicates with the receiving cavity. A bevel gear is rotatably mounted in the mounting hole through a rolling bearing. The end of the bevel gear facing the outside of the chuck body is provided with an interface groove. The end of the spool facing the first annular boss is provided with face teeth that mesh with the bevel gear. A chuck wrench is detachably mounted in the interface groove. Rotating the chuck wrench can drive the bevel gear to rotate.

4. The key-bar type air shaft repair device according to claim 3, characterized in that: A fixed-axis moving structure is provided between the fixed-axis seat and the worktable. The fixed-axis moving structure includes a moving groove set on the worktable for installing the fixed-axis seat. Moving guide grooves are provided on both sides of the moving groove. Moving guide strips are provided on both sides of the fixed-axis seat corresponding to the moving guide grooves. A moving screw is passed through the fixed-axis seat. One end of the moving screw is rotatably connected to the end side wall of the moving groove through a bearing. A rotating handle is fixedly connected to the end of the moving screw away from the worktable. Turning the rotating handle can drive the moving screw to rotate.

5. A key-bar type air shaft repair device according to claim 1, characterized in that: The support assembly includes a V-shaped support block, a support base for mounting the V-shaped support block, a lifting screw with one end threadedly connected to the V-shaped support block, and a lifting motor for driving the lifting screw to rotate. The support base has a support guide groove, and the V-shaped support block is slidably mounted in the support guide groove. The bottom of the support base has a screw hole, and the lifting screw passes through the screw hole. The end of the lifting screw away from the V-shaped support block is connected to the output shaft of the lifting motor. The output shaft of the lifting motor drives the lifting screw to rotate, thereby driving the V-shaped support block to move up and down in the support guide groove.

6. A method for repairing an air shaft, using the key-bar type air shaft repair device according to any one of claims 1-5, comprising the following steps: S1: Adjust the operating cavity diameter according to the shaft diameter of the air shaft to be repaired, so that the clamping bar slides radially synchronously and adjusts the clamping cavity to the size that can accommodate the air shaft; S2: Pass the air shaft to be repaired through the clamping cavity, fix one end of it with the fixed shaft assembly, and support the other end with the support assembly; S3: Adjust the key alignment structure so that each clamping unit of each assembly clamping unit is aligned with the key bar on the air shaft in the axial direction. S4: Inflate the air shaft to make the key bar extend out of the surface, operate the cavity diameter adjustment structure to shrink the clamping cavity shaft diameter, so that each clamping unit is aligned with the key bar position on the air shaft in the radial direction; S5: Release the fixed shaft assembly from fixing the air shaft, rotate the air shaft so that the clamping part of each clamping unit is inserted into the corresponding hole on the key bar and re-fix the air shaft; S6: Activate the induction heating component to heat the air shaft head to the preset temperature, remove the shaft head and air bladder, and then perform subsequent maintenance operations; S7: After the repair is completed, heat and install the air bag and shaft head. After the air shaft head cools down and the shaft head is tightly connected to the air shaft body, release the fixation of the air shaft, inflate the air bag and rotate the air shaft in the opposite direction to make the key strip disengage from the clamping part, expand the clamping cavity size, take out the repaired air shaft, and complete the repair.

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