A device and method for tightening bolts between compressor discs with large disc diameter ratio

Abstract

The present invention belongs to the field of aerospace manufacturing technology, and specifically discloses a bolt tightening device and method for large-disc-diameter ratio compressor discs, comprising: a hoisting platform, on which an adjustment platform is provided; a supply part, capable of storing multiple nuts; a driving part, which is provided on the adjustment platform; a mounting arm, with a mounting joint and a transmission joint at both ends respectively, and the transmission joint is connected to the driving end; a steering knuckle is also provided on the mounting arm, and the steering knuckle is used to adjust the straight-line distance between the mounting joint and the transmission joint; an identification control module is used to identify the discharge end and the bolt; it has the following advantages: it can realize precise tightening of bolts with small size, large disc-diameter ratio and long distance, breaking through the range limitation of the operating space of the conventional L-shaped tightening arm, and is suitable for the blind cavity structure of the aircraft engine rotor disc shaft in which the ratio of the diameter of the position distribution circle of the bolt to be tightened to the diameter of the narrowest disc core inner hole is greater than 3, thereby improving the application range and assembly level of the aircraft engine rotor automatic tightening device.

Description

Technical Field

[0001] The present invention relates to the field of aerospace manufacturing technology, and in particular to a device and method for tightening bolts between compressor discs with a large disc-to-diameter ratio. Background Art

[0002] The connections between rotor disks of large bypass ratio aircraft engines are made by using array flange bolts, such as Figure 1 The figure shows a cross-sectional view of a large-disc-to-cavity ratio compressor. The bolts are located relatively far from the compressor's centerline, but relatively close to the compressor's surrounding walls. Due to the limited internal space of the aircraft engine rotor, this creates an inaccessible and invisible blind cavity assembly environment, making assembly of the nuts that mate with the bolts difficult.

[0003] The assembly process of aircraft engines is complex and requires high precision. However, the actual assembly process is full of human factors, and non-standard and uncontrolled situations often occur. Problems such as incorrect or missed assembly are difficult to completely eliminate, leaving major hidden dangers. Due to the lack of systematic automation and specialized tightening equipment and other feasibility reasons, the actual tightening process of aircraft engine bolt groups cannot be achieved by simultaneously loading axial loads on multiple bolts. Instead, the axial load can only be loaded on each bolt in the bolt group one by one in a certain sequence. In the actual tightening process, the tightening torque and angle of the bolt connection are greatly affected by factors such as mechanical transmission and temperature, and cannot form a strict correspondence with the theoretical angle and torque. The tightening torque fluctuation phenomenon affects the preload of the array bolts, thereby affecting the assembly accuracy and assembly connection stiffness, and ultimately affecting the assembly performance of the aircraft engine.

[0004] The current method for tightening nut connections in aircraft engines typically relies on manually inserting the nut into the disc cavity for installation, followed by a bow wrench for force limiting. However, this closed blind cavity structure has poor accessibility, making it difficult to insert the cap and accurately position the wrench during the force limiting process, resulting in assembly quality that fails to meet process requirements.

[0005] The current tightening method generally uses an L-shaped wrench to tighten the inter-disc bolts. However, when tightening large-diameter blind cavity bolts, the inner diameter of the inter-disc limits the length of the L-shaped wrench, which in turn prevents the L-shaped tightening arm from reaching above the diameter circle of the bolt. Furthermore, tightening large-diameter engine rotor inter-disc bolts requires the use of specialized tooling to ensure proper installation and tightening of the bolts. However, errors can still occur during the use of tooling, such as insufficient tooling accuracy and low levels of automated control. These errors can result in under-tightening or over-tightening of the bolts, thereby affecting the performance and life of the entire engine.

[0006] Therefore, a device and method for tightening bolts between disks of a large disk-to-diameter ratio compressor are proposed to solve the above-mentioned problems. Summary of the Invention

[0007] The present invention aims to provide a device and method for tightening bolts between disks of a large disk-to-diameter ratio compressor, so as to solve or improve at least one of the above-mentioned technical problems.

[0008] In view of this, a first aspect of the present invention is to provide a bolt tightening device for a large-disc-to-diameter ratio compressor.

[0009] A second aspect of the present invention is to provide a method for tightening bolts between disks of a compressor with a large disk-to-diameter ratio.

[0010] A first aspect of the present invention provides a bolt tightening device for a large-disc-diameter ratio compressor disk, comprising: a hoisting platform, which can be moved in a lifting manner in the cavity of the compressor by an external hoisting machine, and an adjustment platform is rotatably provided on the hoisting platform; a supply part, which can store a plurality of nuts, and the supply part is provided with a discharge end, and the discharge end passes through the adjustment platform from top to bottom, and a loading plane is provided at the bottom of the adjustment platform, and the port of the discharge end is located in the loading plane; a driving part, the adjustment platform has an axis, and the driving part is eccentrically arranged on the adjustment platform, and the driving part is provided with a driving end, and the driving end protrudes downward. From the loading plane; the mounting arm, with a mounting joint and a transmission joint at both ends respectively, the mounting joint is used to load the nuts dropped from the discharge end on the loading plane, and install the nuts on the bolts in the cavity of the compressor, the transmission joint is connected to the driving end to drive the mounting joint to move between the discharge end and multiple bolts, and drive the mounting joint to rotate; the mounting arm is also provided with a steering knuckle, and is located between the mounting joint and the transmission joint, the steering knuckle is used to adjust the straight-line distance between the mounting joint and the transmission joint; an identification control module is used to identify the discharge end and the bolts, and to operate the driving part and the supply part, and the identification control module is provided on the mounting arm.

[0011] The present invention provides a bolt tightening device for large-disc-diameter ratio compressor discs, which is suitable for high-efficiency, low-vibration domestic large-disc-diameter aircraft engine rotors, and provides technical support for the future automated assembly of domestic aircraft engines.

[0012] In addition, the technical solution provided by the embodiment of the present invention may also have the following additional technical features:

[0013] In any of the above technical solutions, the line connecting the mounting knuckle and the steering knuckle and the line connecting the transmission knuckle and the steering knuckle have an angle, and the angle changes with the straight-line distance; and / or the lifting platform is provided with a plurality of lifting rings along the circumference of the axis, and each of the lifting rings is respectively connected to the rope of the external lifting machine; and / or the part of the driving part other than the driving end and the supply part are all located on the side of the loading plane away from the mounting arm.

[0014] In this technical solution, when the linear distance between the mounting section and the transmission section changes, the included angle also changes. This allows the mounting arm to bend and deform, enabling it to adapt to bolt points in the compressor cavity that are not directly accessible, thereby improving installation capabilities in complex environments.

[0015] By connecting ropes individually through multiple lifting rings, the lifting platform can be tilted at different angles by different extension amounts, so that the installation section can be installed at different tilt angles, allowing for more bolt fixing angles in the compressor cavity layout, leaving space for the overall mechanical design;

[0016] By locating all parts of the driving part except the driving end and the supply part on the side of the loading plane away from the mounting arm, the center of gravity of the device can be located on the side of the loading plane away from the mounting arm. During the repeated bending and adjustment of the mounting arm, the interference with the overall lifting posture of the device can be reduced, thereby ensuring the smooth docking of the mounting section and the bolt.

[0017] In any of the above technical solutions, the mounting arm further includes: a first arm body and a second arm body connected through the steering knuckle; the mounting knuckle is mounted on the end of the second arm body away from the steering knuckle; and the transmission knuckle is mounted on the end of the first arm body away from the steering knuckle.

[0018] In this technical solution, the mounting arm is designed as a two-section first arm and second arm structure, which can bend like an arm under the action of the steering knuckle, and can be adjusted to adapt to the position of bolts closer to the discharge end and farther away, thereby increasing the lateral travel of the installation to accommodate compressors with a large disk-to-diameter ratio.

[0019] By installing the mounting section at the end of the second arm away from the steering knuckle, the distance that the mounting section can reach outward can be further increased, and interference between the second arm and the internal structure of the compressor when the mounting section is connected to the bolt position can be reduced.

[0020] By installing the transmission joint at the end of the first arm body away from the steering knuckle, most of the structures of the first arm body and the second arm body are placed between the installation joint and the transmission joint, ensuring that the overall arm length of the installation arm is maximized.

[0021] In any of the above technical solutions, the first arm body and the second arm body are both hollow, and a plurality of transmission wheels arranged in a linear shape and connected to each other are respectively arranged inside, and the steering knuckle is provided with a steering wheel connected to the transmission wheels of the first arm body and the second arm body respectively; the mounting joint is fixedly connected to the transmission wheel of the second arm body; and the transmission joint is rotatably connected to the transmission wheel of the first arm body.

[0022] In this technical solution, force transmission between the first arm and the second arm is achieved through a plurality of transmission wheels arranged linearly and interconnected to drive the installation section at the far end to rotate. The steering wheel is connected to the transmission wheel, so that the first arm and the second arm can transmit force internally while rotating relative to each other, so that the rotating installation section can be fine-tuned according to the position of the bolt under the control of the identification control module, and can be screwed and fixed after docking.

[0023] In any of the above technical solutions, the driving end includes a first driving shaft and a second driving shaft, the first driving shaft is provided with a hollow portion along the axial direction, and the second driving shaft is coaxially arranged in the hollow portion; the first driving shaft is fixedly connected to the transmission joint to drive the mounting arm to rotate circumferentially along the axis; the second driving shaft passes through the transmission joint and is fixedly connected to the transmission wheel to drive the mounting joint to rotate through the transmission wheel and the steering wheel; and the mounting arm also includes a steering assembly, the steering assembly is installed on the first arm body, and the output shaft of the steering assembly is connected to one end of the second arm body close to the transmission joint to drive the second arm body to rotate circumferentially with the steering knuckle as the center.

[0024] In this technical solution, the hollow portion allows the first drive shaft and the second drive shaft to be mutually sleeved, so as to rotate and longitudinally move the same mounting wall, and control the rotation of the mounting section on the mounting arm;

[0025] The first drive shaft is fixedly connected to the transmission joint, and the rotation of the first drive shaft directly drives the transmission joint to rotate, and further drives the entire mounting arm to rotate, so that the mounting joint rotates circumferentially around the transmission joint with the mounting arm as a radius;

[0026] The second drive shaft passes through the transmission joint and is fixedly connected to the transmission wheel, which can transmit the rotational driving force to the transmission wheel corresponding to the transmission joint, and transmits the power in turn through the transmission wheel on the transmission joint and other transmission wheels, and finally drives the installation joint to rotate;

[0027] By installing the steering assembly on the first arm body and connecting the output shaft of the steering assembly to the end of the second arm body close to the transmission joint, the steering assembly drives the second arm body to rotate around the steering knuckle as the origin with its own radius when the first arm body does not change its position, so that the first arm body and the second arm body can rotate autonomously relative to each other to achieve autonomous bending and expansion of the mounting arm.

[0028] In any of the above technical solutions, the steering assembly includes: a motor, which is arranged on the first arm; a linkage rod, whose ends are respectively connected to the output end and the output shaft of the motor to transmit the power generated by the motor to the output shaft, and drive the output shaft to move circumferentially with the steering knuckle as the center; wherein a round waist hole is provided at the connection between the linkage rod and the output shaft, and the round waist hole is slidably connected to the side wall of the output shaft; and / or the axis of the linkage rod is perpendicular to and intersects with the output end of the motor and the axis of the output shaft.

[0029] In this technical solution, the power of the steering assembly is generated by the motor, and the generated power is transmitted to the output shaft through the linkage rod, and further drives the second arm to rotate;

[0030] Since the output shaft of the motor is not collinear with the axis of the steering knuckle, a rounded hole is provided at the connection between the linkage rod and the output shaft to adapt to and offset the deviation displacement generated when the linkage rod drives the steering knuckle to rotate, thereby reducing interference between the structures.

[0031] The axes of the linkage rods are perpendicular to and intersect with the output end of the motor and the axis of the output shaft, so that the overall structure is Z-shaped. When the linkage rods swing, they can approach the surface of the mounting arm and the swing direction is parallel to the mounting arm, thereby reducing the outward protrusion of the linkage rods during transmission and reducing interference and collision with the internal structure of the compressor.

[0032] In any of the above technical solutions, the adjustment platform is used to drive the installation arm connected to the driving part to move circumferentially with the axis as the center, so as to screw nuts on the circumferentially distributed bolts in the compressor cavity in sequence; the steering assembly is used to cooperate with the adjustment platform and the first drive shaft, so that the installation joint can move circumferentially with the steering knuckle and / or the axis and / or the installation joint as the center close to the bolt, or the installation joint can move circumferentially with the steering knuckle and / or the installation joint as the center close to the discharge end; the driving part is used to drive the first drive shaft and / or the second drive shaft to rotate, and / or drive the first drive shaft and the second drive shaft to move synchronously along the axial direction.

[0033] In this technical solution, a mounting arm connected to the drive unit is rotatably mounted on the hoisting platform to move circumferentially around the axis, thereby enabling a plurality of bolts distributed circumferentially within the compressor to be docked and installed at one time. The mounting arm is responsible for the circumferential movement of the plurality of bolts during the fixing process.

[0034] The adjusting table can drive the installation joint to move in the circumferential direction of the first circle. The first drive shaft drives the transmission joint to rotate, so that the installation joint on the installation arm can make a circular motion in the middle section with the transmission joint as the center. The steering assembly drives the second arm body to rotate, so that the installation joint on the second arm body can make a circumferential motion with the steering knuckle as the center. The three circumferential motions can be carried out simultaneously without interfering with the rotation of the installation joint, so as to achieve greater flexibility.

[0035] When the installation section returns to the discharge end to reload the nut, the second drive shaft and the steering device can be used as nodes to rotate and call back;

[0036] The driving portion can rotate the first driving shaft and the second driving shaft in the same direction or in opposite directions, can also drive one of them to rotate, and can also drive the first driving shaft and the second driving shaft to move along the axial direction.

[0037] In any of the above technical solutions, the driving part includes: a coupling, which is rotatably connected to the second driving shaft and fixedly connected to the outer wall of the first driving shaft; a tightening gun, which is fixed on the coupling, and the rotating shaft of the tightening gun is connected to the second driving shaft; a cam module, which is installed on the adjustment table, and the output end of the cam module is rotatably connected to the outside of the first driving shaft to drive the first driving shaft to move along the axial direction; a motor module, which is installed on the adjustment table, and the output end of the motor module is slidably connected to the outside of the first driving shaft to drive the first driving shaft to rotate.

[0038] In this technical solution, the coupling is used to fix the first drive shaft and the second drive shaft in the axial direction while being able to rotate relative to each other, and on the other hand, it can fix the tightening gun to ensure the driving rotation of the second drive shaft;

[0039] The cam module moves longitudinally through the built-in cam to drive the longitudinal movement of the first drive shaft and the second drive shaft, and enables the mounting section to drive the nut to connect with the bolt upward;

[0040] The motor power input of the motor module can drive the first drive shaft to rotate and further drive the entire mounting arm to rotate around the transmission joint.

[0041] In any of the above technical solutions, the second drive shaft has a center point located on the loading plane where it passes through the loading plane, and the center point, the discharge end, and the midpoint of the loading plane are not collinear; and the position of the discharge end on the loading plane is designed according to the following rules:

[0042]

[0043] Among them, R1 is the radius of the adjustment table, and the center of the circle is R xThe center point of the discharge end is determined on a circle with a radius of 1.50 mm. x is the x-coordinate of the x-axis mounting joint in any direction with the center of the adjustment table as the coordinate origin. y is the y-coordinate of the mounting joint perpendicular to the x-axis with the center of the adjustment table as the coordinate origin. θ1 is the rotation angle of the adjustment table. θ2 is the rotation angle of the second drive shaft. θ3 is the angle between the first and second arms. L1 is the centerline length of the first arm. L2 is the centerline length of the second arm. L0 is the plane distance from the second drive shaft to the center of the adjustment table. The position of the discharge end does not exceed the diameter of the adjustment table in radial position based on the position of the mounting arm, ensuring that no mechanical interference will occur if the nut is hoisted during supply.

[0044] In this technical solution, to improve operational efficiency, enhance precision during repeated nut installation, and reduce nut installation time, the mounting arm's space is designed to meet safety limits. A mechanical latch is incorporated between the first and second arms, ensuring precise positioning of the mounting arm during nut delivery. Once the mounting arm is deployed to position one, the motor drives the mounting arm coupling, driving the inner arm to deploy.

[0045] The present invention provides a tightening method of a tightening device based on any one of the technical solutions in the first aspect, comprising the following steps: S1, starting a driving part to drive the rotation and longitudinal movement of the installation joint and the transmission joint, at this time rotating the steering knuckle so that the installation joint and the transmission joint are close to each other and are below the loading plane, and the installation joint longitudinally corresponds to the discharge end; S2, the supply part selects any one of a plurality of stored nuts to fall out through the discharge end and fall into the installation joint; S3, by rotating the transmission joint, the installation arm is rotated to a certain angle, the steering knuckle is reversed so that the installation joint and the transmission joint are away from each other and the installation arm is unfolded, so that the installation joint with the nut is close to the bottom of the bolt to be fixed; S4, the identification control module identifies the position of the bolt to be tightened, and completes the longitudinal correspondence between the nut and the bolt; S5, the installation joint drives the nut to rotate, and under the drive of the rotating joint, they jointly lean upward against the bolt until the threaded connection is completed; S6, reset the installation joint so that it is located below the discharge end and returns to S2.

[0046] The present invention provides a method for tightening bolts between disks of a large disk-to-diameter ratio compressor. Since the tightening method is implemented by the tightening device described in any one of the first aspects, the tightening method includes all the beneficial effects of the tightening device, which will not be repeated here.

[0047] Compared with the prior art, the present invention has the following beneficial effects:

[0048] The device of the present invention is a fully automatic nut tightening device for blind cavity nut connection of high-pressure rotor with large disk cavity ratio. The series of actions and functions including identification of the position of the bolt to be tightened, reaching the next bolt to be tightened, expansion and contraction of the installation arm, lifting and lowering of the installation arm when the nut is screwed in, screwing of the nut, application of pre-tightening force and filling of the nut are fully automated according to the tightening process. It has the characteristics of high degree of automation and high tightening precision, reduces the skill requirements and labor intensity of workers, avoids errors introduced by manual operation, and ensures the consistency of internal nut tightening.

[0049] During the entire tightening process, the identification control module of the device of the present invention is difficult to mark the tightened and untightened bolts due to the lack of feature differences between the internal space of the rotor disk and the bolts. Therefore, in actual production, workers perform positioning based on visual inspection and experience, which is difficult and prone to incorrect tightening or missed tightening. After tightening the circumferential bolts of the rotor, the device of the present invention will adjust the motor to calculate the current position of the device according to the tightening strategy of the cross-cross method, and record the tightening status of the annular array bolts in real time through the upper computer software and mark them. In addition, the camera of the visual control module transmits the image of the tightening sleeve to the upper computer in real time to automatically mark the tightening sequence and tightening status of the remaining bolts, and visualizes the marking results. The image of the tightening sleeve is transmitted to the external operation and monitoring panel in real time, and monitors whether there is missed tightening, wrong tightening, or nut falling, and controls the device to perform corresponding operations. This overcomes the difficulties of traditional manual tightening in that the field of view inside the high-pressure compressor disc cavity is inaccessible and the tightening status is obtained by touch.

[0050] The device of the present invention does not rely on an engine in which the position of the bolt to be tightened inside the compressor blind cavity has a certain relationship with the position of the bolt hole on the compressor external flange. During implementation, since the cross-cross method requires selecting the first bolt to be tightened among the circumferential bolts, the structural characteristics of the rotor blind cavity that do not correspond to the inside and outside make it impossible for the operator to intuitively observe the distribution of the bolt positions on the rotor disk. Therefore, the tightening equipment needs to perform initial positioning of the bolt positions. The device of the present invention identifies the center line of the bolt through deep learning and sends the identification information to the control system to realize automatic identification of the first bolt position during the nut tightening process.

[0051] The device of the present invention adopts a tightening strategy such as a cross method and a triangle method according to the needs of the tightening process to flexibly adjust the relevant mechanisms and control programs of the device of the present invention. The present invention can modify the automation process of the device through the host computer, including automatic adjustment of the tightening sequence, tightening process and parameters, and device action sequence to achieve nut recognition, screwing, and pre-tightening force loading;

[0052] Additional aspects and advantages of embodiments according to the present invention will become apparent in the following description or may be learned through practice of embodiments according to the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments with reference to the following drawings, in which:

[0054] Figure 1 It is a structural schematic diagram of the aircraft engine compressor of the present invention;

[0055] Figure 2 It is a structural schematic diagram of the present invention;

[0056] Figure 3 Schematic diagram of the supply part and its connection structure of the present invention;

[0057] Figure 4 It is a schematic diagram of the mounting arm and its connection structure of the present invention;

[0058] Figure 5 This is a schematic diagram of the position adjustment motor and its connection according to the present invention;

[0059] Figure 6 is a schematic diagram of the deployment of the mounting arm of the present invention;

[0060] Figure 7 A schematic diagram of the bending of the mounting arm of the present invention;

[0061] Figure 8 It is a schematic diagram of the cross-sectional structure of the supply part of the present invention.

[0062] in, Figure 1-8 The corresponding relationship between the reference numerals and component names is as follows:

[0063] 1 Lifting platform, 101 Adjusting platform, 1011 Positioning motor, 2 Supply unit, 201 Storage cover, 202 Seasoning ring, 203 Adjusting motor, 204 Blanking pipe, 205 Blanking nozzle, 3 Driving unit, 301 First driving shaft, 302 Second driving shaft, 303 Coupling, 304 Tightening gun, 305 Cam module, 3051 Transmission plate, 306 Motor module, 4 Mounting arm, 401 Mounting joint, 402 Transmission joint, 403 Steering knuckle, 404 Second arm body, 405 First arm body, 406 Transmission wheel, 407 Steering wheel, 408 Steering assembly, 4081 Motor, 4082 Linkage rod, 4083 Round waist hole, 4084 Output shaft, 5 Identification control module, 6 Bolts. DETAILED DESCRIPTION

[0064] In order to more clearly understand the above-mentioned objects, features and advantages of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that, in the absence of conflict, the embodiments of the present application and the features therein can be combined with each other.

[0065] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the scope of protection of the present invention is not limited to the specific embodiments disclosed below.

[0066] See also Figure 1-8 The following describes some embodiments of the present invention, including a device and method for tightening bolts between disks of a compressor with a large disk-to-diameter ratio.

[0067] The embodiment of the first aspect of the present invention provides a device for tightening bolts between disks of a large disk-diameter ratio compressor. In some embodiments of the present invention, such as Figure 2-8 As shown, a bolt tightening device for a compressor with a large disk diameter ratio is provided, the bolt tightening device for a compressor with a large disk diameter ratio comprises:

[0068] The hoisting platform 1 can be moved in the compressor cavity by an external hoisting machine, and the hoisting platform 1 is rotatably provided with an adjustment platform 101;

[0069] The supply part 2 is capable of storing a plurality of nuts. The supply part 2 is provided with a discharge end, which passes through the adjustment table 101 from top to bottom. The bottom of the adjustment table 101 is provided with a loading plane, and the port of the discharge end is located in the loading plane;

[0070] The driving part 3 and the adjustment platform 101 have an axis, and the driving part 3 is eccentrically arranged on the adjustment platform 101. The driving part 3 is provided with a driving end, and the driving end protrudes downward from the loading plane;

[0071] The mounting arm 4 has a mounting section 401 and a transmission section 402 at both ends. The mounting section 401 is used to load nuts dropped from the discharge end onto the loading plane and install the nuts on the bolts 6 in the compressor cavity. The transmission section 402 is connected to the driving end to drive the mounting section 401 to move between the discharge end and the plurality of bolts 6 and to drive the mounting section 401 to rotate. The mounting arm 4 is also provided with a steering knuckle 403 located between the mounting section 401 and the transmission section 402. The steering knuckle 403 is used to adjust the linear distance between the mounting section 401 and the transmission section 402.

[0072] The identification control module 5 is used to identify the discharge end and the bolt 6 and to control the driving part 3 and the supply part 2 . The identification control module 5 is set on the mounting arm 4 .

[0073] Furthermore, the hoisting platform is equipped with a positioning motor 1011, which drives the adjusting platform 101 to rotate around the axis through a worm gear structure.

[0074] The embodiment of the first aspect of the present invention proposes a bolt tightening device for large-disc-diameter ratio compressor discs. The device is suitable for an engine disc shaft blind cavity structure in which the ratio of the diameter D of the distribution circle of the bolt position to be tightened to the diameter d of the narrowest disc center inner hole is greater than 3. It breaks through the operating space limitation of conventional blind cavity tightening using an L-shaped tightening arm, and provides technical support for tightening blind cavity bolts in new large-disc-diameter high-pressure compressors.

[0075] Furthermore, the supply part 2 includes: a material storage cover 201, a seasoning ring 202, an adjustment motor 203, a material drop pipe 204 and a material drop nozzle 205;

[0076] A plurality of through holes for accommodating nuts are opened on the circumference of the storage cover 201. The upper surface of the seasoning ring 202 is rotatably connected to the storage cover 201, and a drop pipe 204 is installed through the upper surface of the seasoning ring 202. The upper surface of the drop pipe 204 is flush with the upper surface of the seasoning ring 202. The lower end of the drop pipe 204 is the discharge end of the supply part 2. The adjusting motor 203 is fixed on the inner wall of the seasoning ring 202, and an output gear is installed at the output end of the adjusting motor 203. The output gear engages with the input gear. The input gear is coaxially installed on the lower surface of the storage cover 201 to drive the storage cover 201 to rotate.

[0077] Furthermore, the supply part 2 also includes: a blanking nozzle 205, which is installed at the lower end of the blanking pipe 204, and is used to reduce the distance the nut flies after falling out to avoid falling off.

[0078] In some embodiments, a line connecting the mounting joint 401 and the steering knuckle 403 and a line connecting the transmission joint 402 and the steering knuckle 403 have an angle, and the angle changes with the straight-line distance; and / or

[0079] The hoisting platform 1 is provided with a plurality of hoisting rings along the circumference of the axis, and each hoisting ring is connected to a rope of an external hoisting machine; and / or

[0080] The portion of the driving portion 3 other than the driving end and the supply portion 2 are all located on the side of the loading plane facing away from the mounting arm 4 .

[0081] In this embodiment, when the linear distance between the mounting section 401 and the transmission section 402 changes, the included angle also changes. This allows the mounting arm 4 to bend and deform, enabling it to adapt to the inaccessible bolt 6 points in the compressor cavity, thereby improving installation capabilities in complex environments.

[0082] By connecting ropes individually through multiple lifting rings, the lifting platform 1 can be tilted at different angles by different extension amounts, so that the mounting section 401 can be installed at different tilt angles, allowing for more bolt 6 fixing angles in the compressor cavity layout, leaving space for the overall mechanical design;

[0083] By locating the driving part 3 except the driving end and the supply part 2 on the side of the loading plane away from the mounting arm 4, the center of gravity of the device can be located on the side of the loading plane away from the mounting arm 4. During the repeated bending and adjustment of the mounting arm 4, the interference with the overall lifting posture of the device can be reduced, thereby ensuring the smooth docking of the mounting section 401 and the bolt 6.

[0084] In some embodiments, the mounting arm 4 further includes: a first arm body 405 and a second arm body 404 connected via a steering knuckle 403;

[0085] The mounting joint 401 is mounted on one end of the second arm 404 away from the steering knuckle 403;

[0086] The transmission joint 402 is mounted on one end of the first arm 405 away from the steering knuckle 403 .

[0087] In this embodiment, the mounting arm 4 is designed as a two-section structure consisting of a first arm body 405 and a second arm body 404. It can bend like an arm under the action of the steering knuckle 403, and can be adjusted to accommodate the position of the bolt 6 closer to the discharge end and farther away. This increases the lateral travel of the installation to accommodate compressors with a large disk-to-diameter ratio.

[0088] By installing the mounting section 401 at the end of the second arm 404 away from the steering knuckle 403, the distance that the mounting section 401 can reach outward can be further increased, and the interference between the second arm 404 and the internal structure of the compressor when the mounting section 401 is connected to the bolt 6 can be reduced.

[0089] By installing the transmission joint 402 at the end of the first arm 405 away from the steering knuckle 403, most of the structures of the first arm 405 and the second arm 404 are placed between the installation joint 401 and the transmission joint 402, ensuring that the overall arm length of the installation arm 4 is maximized.

[0090] Furthermore, the mounting section 401 is a sleeve-like structure, and the interior is set to a 12-square structure according to the shape of the tightened nut. At the same time, in order to facilitate the supply of the nut, the internal 12-square structure is adaptively designed for chamfering. At the same time, the exterior of the mounting section 401 is a gear-like structure, and its gear module is the same as the module of the second arm body 404 and the first arm body 405 for gear transmission to transmit torque. At the same time, cylinders are designed at both ends of the exterior of the mounting section 401 for installing plastic bearings (self-lubricating) for circumferential support.

[0091] In some embodiments, the first arm 405 and the second arm 404 are both hollow, and are provided with a plurality of linearly arranged and interconnected transmission wheels 406 inside, and the steering knuckle 403 is provided with a steering wheel 407 connected to the transmission wheels 406 of the first arm 405 and the second arm 404 respectively.

[0092] The mounting section 401 is fixedly connected to the transmission wheel 406 of the second arm 404;

[0093] The transmission joint 402 is rotatably connected to the transmission wheel 406 of the first arm 405 .

[0094] In this embodiment, force transmission between the first arm 405 and the second arm 404 is achieved by a plurality of transmission wheels 406 arranged linearly and interconnected to drive the installation section 401 at the far end to rotate. The steering wheel 407 is connected to the transmission wheel 406, so that the first arm 405 and the second arm 404 can transmit force internally while rotating relative to each other, so that the rotating installation section 401 can be fine-tuned with respect to the position of the bolt 6 under the control of the identification control module 5, and can be screwed and fixed after docking is completed.

[0095] Specifically, the transmission wheel 406 and the steering wheel 407 are both gears and mesh with each other. The transmission wheel 406 meshing with the steering wheel 407 can not only mesh with it to transmit power, but also mesh and rotate around the steering wheel 407 during meshing, so that the second arm 404 rotates around the steering knuckle 403.

[0096] In some embodiments, the driving end includes a first driving shaft 301 and a second driving shaft 302 , wherein the first driving shaft 301 has a hollow portion along the axial direction, and the second driving shaft 302 is coaxially disposed in the hollow portion;

[0097] The first drive shaft 301 is fixedly connected to the transmission joint 402 to drive the mounting arm 4 to rotate circumferentially along the axis;

[0098] The second drive shaft 302 shown passes through the transmission joint 402 and is fixedly connected to the transmission wheel 406 to drive the installation joint 401 to rotate through the transmission wheel 406 and the steering wheel 407; and

[0099] The mounting arm 4 also includes a steering assembly 408, which is mounted on the first arm 405, and an output shaft 4084 of the steering assembly 408 is connected to one end of the second arm 404 close to the transmission joint 402 to drive the second arm 404 to rotate circumferentially around the steering joint 403.

[0100] In this embodiment, the hollow portion allows the first drive shaft 301 and the second drive shaft 302 to be mutually nested, so as to rotate and longitudinally move the same mounting wall, and control the rotation of the mounting section 401 on the mounting arm 4;

[0101] The first drive shaft 301 is fixedly connected to the transmission section 402. The rotation of the first drive shaft 301 directly drives the transmission section 402 to rotate, and further drives the entire mounting arm 4 to rotate, so that the mounting section 401 rotates circumferentially around the transmission section 402 with the mounting arm 4 as the radius.

[0102] The second drive shaft 302 passes through the transmission section 402 and is fixedly connected to the transmission wheel 406. It can transmit the rotational driving force to the transmission wheel 406 corresponding to the transmission section 402, and then transmit the power in sequence through the transmission wheel 406 on the transmission section 402 and other transmission wheels 406, and finally drive the installation section 401 to rotate.

[0103] By installing the steering assembly 408 on the first arm body 405 and connecting the output shaft 4084 of the steering assembly 408 to the end of the second arm body 404 close to the transmission joint 402, the steering assembly 408 drives the second arm body 404 to rotate around the steering knuckle 403 as the origin with itself as the radius when the first arm body 405 does not change its position, so that the first arm body 405 and the second arm body 404 can rotate autonomously relative to each other, thereby realizing autonomous bending and unfolding of the mounting arm 4.

[0104] In some embodiments, the steering assembly 408 includes:

[0105] The motor 4081 is provided on the first arm 405;

[0106] The ends of the linkage rod 4082 are respectively connected to the output end of the motor 4081 and the output shaft 4084, so as to transmit the power generated by the motor 4081 to the output shaft 4084 and drive the output shaft 4084 to move circumferentially around the steering knuckle 403;

[0107] Among them, a round waist hole 4083 is opened at the connection between the linkage rod 4082 and the output shaft 4084, and the round waist hole 4083 is slidingly connected to the side wall of the output shaft 4084; and / or the axis of the linkage rod 4082 is perpendicular to and intersects with the output end of the motor 4081 and the axis of the output shaft 4084.

[0108] In this embodiment, the power of the steering assembly 408 is generated by the motor 4081, and the generated power is transmitted to the output shaft 4084 through the linkage rod 4082, and further drives the second arm 404 to rotate;

[0109] Since the output shaft 4084 of the motor 4081 is not colinear with the axis of the steering knuckle 403, a rounded hole 4083 is provided at the connection between the linkage rod 4082 and the output shaft 4084. This allows the linkage rod 4082 to adapt to and offset the deviation displacement generated when the steering knuckle 403 is driven to rotate, thereby reducing interference between the structures.

[0110] The axis of the linkage rod 4082 is perpendicular to and intersects with the output end of the motor 4081 and the axis of the output shaft 4084, so that the overall structure is Z-shaped. The linkage rod 4082 can be close to the surface of the mounting arm 4 when swinging and the swinging direction is parallel to the mounting arm 4, thereby reducing the outward protrusion of the linkage rod 4082 during transmission and reducing interference and collision with the internal structure of the compressor.

[0111] In some embodiments, the adjustment platform 101 is used to drive the mounting arm 4 connected to the driving part 3 to move circumferentially with the axis as the center, so as to sequentially screw nuts on the bolts 6 distributed circumferentially in the cavity of the compressor;

[0112] The steering assembly 408 is used to cooperate with the adjustment platform 101 and the first drive shaft 301, so that the mounting section 401 can move circumferentially with the steering knuckle 403 and / or the axis and / or the mounting section 401 as the center to approach the bolt 6, or the mounting section 401 can move circumferentially with the steering knuckle 403 and / or the mounting section 401 as the center to approach the discharge end;

[0113] The driving unit 3 is used to drive the first driving shaft 301 and / or the second driving shaft 302 to rotate, and / or drive the first driving shaft 301 and the second driving shaft 302 to move synchronously along the axial direction.

[0114] In this embodiment, the mounting arm 4 connected to the driving unit 3 is moved circumferentially with the axis as the center by means of a rotatable adjustment platform 101 mounted on the hoisting platform 1, so that multiple bolts 6 distributed circumferentially in the compressor can be docked and installed at one time. The adjustment platform 101 is responsible for the circumferential movement of the multiple bolts 6 during the fixing process.

[0115] The adjustment platform 101 can drive the installation joint 401 to perform a large circumferential movement in the first circle, and the first drive shaft 301 drives the transmission joint 402 to rotate, so that the installation joint 401 on the installation arm 4 performs a circular motion in the middle section with the transmission joint 402 as the center. The steering assembly 408 drives the second arm body 404 to rotate, so that the installation joint 401 on the second arm body 404 can perform a circumferential motion with the steering joint 403 as the center. The three circumferential motions can be performed simultaneously without interfering with the rotation of the installation joint 401, thereby achieving greater flexibility.

[0116] When the installation section 401 returns to the discharge end for re-loading of nuts, the second drive shaft 302 and the steering device can be used as nodes to rotate and call back with the steering section 403 and the transmission section 402 as nodes;

[0117] The driving unit 3 can rotate the first driving shaft 301 and the second driving shaft 302 in the same direction or in the opposite direction, can also drive one of them to rotate, and can also drive the first driving shaft 301 and the second driving shaft 302 to move along the axial direction.

[0118] In some embodiments, the driving unit 3 includes:

[0119] A coupling 303 is rotatably connected to the second drive shaft 302 and fixedly connected to the outer wall of the first drive shaft 301;

[0120] A tightening gun 304 is fixed on the coupling 303, and a rotating shaft of the tightening gun 304 is connected to the second driving shaft 302;

[0121] The cam module 305 is mounted on the adjustment platform 101. The output end of the cam module 305 is rotatably connected to the outside of the first drive shaft 301 to drive the first drive shaft 301 to move along the axial direction.

[0122] The motor module 306 is mounted on the adjustment platform 101 , and the output end of the motor module 306 is slidably connected to the outside of the first drive shaft 301 to drive the first drive shaft 301 to rotate.

[0123] In this embodiment, the coupling 303 is used to, on the one hand, fix the first drive shaft 301 and the second drive shaft 302 in the axial direction while being able to rotate relative to each other, and on the other hand, fix the tightening gun 304 to ensure the driving rotation of the second drive shaft 302;

[0124] The cam module 305 moves longitudinally through the built-in cam to drive the longitudinal movement of the first drive shaft 301 and the second drive shaft 302, and enables the mounting section 401 to drive the nut to connect with the bolt 6 upward;

[0125] The power input from the motor 4081 of the motor module 306 can drive the first drive shaft 301 to rotate and further drive the entire mounting arm 4 to rotate around the transmission joint 402 .

[0126] Specifically, the cam module 305 is provided with a longitudinally movable transmission plate 3051. When the cam rotates, the distance from the top to the center of the large cam is different, which drives the transmission plate 3051 to move longitudinally. The transmission plate 3051 is fixedly connected to the first drive shaft to drive the first drive shaft to move longitudinally.

[0127] Specifically, the tightening gun includes a gun body and a tightening gun controller. The tightening gun is an Atlas electric wrench. When the tool is in operation, its built-in gyroscope detects the operator's influence on the tightening process. The torque wrench has a large torque range, high angle accuracy, and adjustable speed. The tightening gun controller is a 6000 series controller. The controller is intuitive to operate and can be navigated using an interface. The operation process is simple and easy to understand. It can be connected to a computer via a network cable and can communicate with a torque calibrator via a network cable. The tightening gun module connects the tightening gun to the tightening gun controller using an STR cable, which can achieve functions such as high-precision control of torque, angle, and yield point, as well as angle monitoring, thereby outputting torque with high precision.

[0128] In any of the above technical solutions, the second drive shaft has a center point located on the loading plane where it passes through the loading plane, and the center point, the discharge end, and the midpoint of the loading plane are not collinear; and the position of the discharge end on the loading plane is designed according to the following rules:

[0129]

[0130] Wherein, R1 is the radius of the adjustment platform, and the center of the circle is the midpoint of the adjustment platform 101. x The center point position of the discharge end 205 is determined on the circumferential point of the radius, x is the x-coordinate value of the x-axis mounting node 401 with the midpoint of the adjusting platform 101 as the coordinate origin, y is the y-coordinate value of the mounting node 401 perpendicular to the x-axis with the midpoint of the adjusting platform 101 as the coordinate origin, θ1 is the rotation angle of the adjusting platform 101, θ2 is the rotation angle of the second drive shaft 302, θ3 is the angle between the first arm body 405 and the second arm body 405, L1 is the centerline length of the first arm body 405, L2 is the centerline length of the second arm body 404, and L0 is the plane distance between the second drive shaft 302 and the center of the adjusting platform 101. The position of the discharge end 205 will not exceed the diameter range of the adjustment platform 101 in the radial position according to the position of the mounting arm, ensuring that no mechanical interference will occur if the nut is hoisted during the supply. The diameter of the adjustment platform is set to R1. The outer arm of the mounting arm is extended by the motor to retract the outer arm. The circumferential worm gear angle and the rotation angle of the inner arm and the outer arm are solved through the plane degree of freedom posture conversion. The robot joint performs inverse calculation and solves the spatial posture of the nut during supply according to the operating space; and calculates R according to the set range. x The value range is used as the design position of the discharge end on the plane.

[0131] In this technical solution, to improve operational efficiency, enhance precision during repeated nut installation, and reduce nut installation time, the space within the mounting arm is designed to meet safety limits. A mechanical latch is designed between the first arm 405 and the second arm 404, ensuring precise positioning of the mounting arm during nut delivery. The mounting arm is deployed to position one, and the motor drives the mounting arm coupling to drive the inner arm to deploy.

[0132] Another embodiment of the first aspect of the present invention comprises:

[0133] The tightening mechanism is L-shaped as a whole, including a long arm formed by a deployable mounting arm and a first drive shaft and a second drive shaft for transmitting torque, which are connected vertically to each other. The deployable mounting arm is divided into an inner arm and an outer arm, wherein the inner arm and the outer arm are connected by a crank slider. The outer arm of the deployable mounting arm is provided with a tightening sleeve with a gear-shaped outer wall at the end of the connection end. The torque transmission shaft is installed with a tightening gun at the end of the connection end to control the input torque and the size of the rotation angle. Figure 7 As shown, the outer and inner arms of the deployable mounting arm include an input gear housed within a housing, a primary inner arm transmission gear, a secondary inner arm transmission gear, an inner arm output gear, an arm input gear, a primary outer arm transmission gear, a secondary outer arm transmission gear, and a tightening sleeve mounted at the front of the housing. The inner arm's input gear's inner race is fixedly attached to the underside of the torque transmission shaft. The inner arm's input gear, primary inner arm transmission gear, secondary inner arm transmission gear, and inner arm output gear mesh in sequence. The extension arm's input gear meshes with the inner arm's output gear. The outer arm's primary transmission gear, secondary outer arm transmission gear, and extension arm output gear mesh in sequence with the extension arm's input gear. The extension arm's output gear meshes with the gear-shaped outer wall of the tightening sleeve.

[0134] The L-shaped tightening mechanism of this embodiment has a two-section mounting arm, which is suitable for an engine disk shaft blind cavity structure in which the ratio of the diameter D of the distribution circle of the bolt positions to be tightened to the diameter d of the narrowest disk core inner hole is greater than 3.

[0135] In particular, the rotating disc placement plate is evenly distributed with multiple axial through-holes, each of which is provided with a groove for receiving a nut. When the deployable mounting arm is in the retracted position, the tightening sleeve is located directly below the nut supply position. In this embodiment, the rotating disc placement plate motor is started to rotate forward, driving the rotating disc placement plate to rotate, thereby driving the nut to rotate. When the nut reaches the hole of the automatic tightening sleeve, the rotating motor is suspended. At this time, the nut on the rotating disc placement plate falls into the conveying pipe until the nut passes through the pipe and reaches the receiving area of the extension arm. After the nut enters the conveying pipe through the tightening sleeve hole and is finally installed on the blade through the extension arm, the extension arm is then retracted, and the center of the nut sleeve received by the extension arm is aligned with the center of the conveying pipe, waiting for the next nut to be received.

[0136] Specifically, the protective sleeve is coaxial with the compressor disc cavity, and its outer diameter is configured to be slightly smaller than the diameter d of the narrowest disc core inner hole, thereby serving as the outer protective shell of the automatic tightening device for the blind cavity nut of the aircraft engine compressor rotor. Advantageously, an opening is provided on the sidewall of the lower end of the protective sleeve for the deployment or retraction of the deployable mounting arm. When the device is installed on the compressor, the deployable mounting arm can be extended from the opening of the protective sleeve to an extended position, or retracted to a retracted position, in which the deployable mounting arm is completely contained within the protective sleeve.

[0137] like Figure 6 As shown, the tightening device of this embodiment also includes an identification control module installed below the mounting arm and adjacent to the tightening sleeve, which is used for bolt positioning and visual monitoring. Preferably, the identification control module includes an LED light source for blind cavity illumination and a miniature camera for image acquisition and monitoring.

[0138] In this embodiment, the identification control module is mounted below the output gear, with its centerline of symmetry coinciding with the centerline of the mounting arm. The identification control module's LED light source and micro-camera are arranged vertically along the engine axis, coinciding with the centerline of symmetry of the mounting arm. The sum of the axial height of the rotor disk to be connected and the height of the mounting arm is less than the minimum inter-disc height of the compressor blind cavity. When the identification control module identifies the location of the bolt to be tightened, it controls the circumferential rotation mechanism to rotate a certain angle to align the tightening sleeve with the axis of the bolt to be tightened.

[0139] The second embodiment of the present invention provides a method for tightening bolts between disks of a large disk-diameter ratio compressor. In some embodiments of the present invention, such as Figure 1 As shown, a method for tightening bolts between compressor discs with a large disc diameter ratio is provided. The method for tightening bolts between compressor discs with a large disc diameter ratio comprises the following steps:

[0140] S1, start the driving part to drive the installation joint and the transmission joint to rotate and move longitudinally. At this time, rotate the steering knuckle so that the installation joint and the transmission joint are close to each other and are below the loading plane, and the installation joint is longitudinally corresponding to the discharge end;

[0141] S2, the supply unit selects any one of the multiple stored nuts and drops it out through the discharge end, and drops it into the installation section;

[0142] S3, by rotating the transmission joint, the mounting arm rotates to a certain angle, the steering knuckle is reversed to move the mounting joint and the transmission joint away from each other, and the mounting arm is unfolded, so that the mounting joint with the nut is close to the bottom of the bolt to be fixed;

[0143] S4, the recognition control module identifies the position of the bolt to be tightened and completes the longitudinal correspondence between the nut and the bolt;

[0144] S5, the installation section drives the nut to rotate, and driven by the rotating section, the nut and the nut are moved upwards to contact the bolt until the threaded connection is completed;

[0145] S6, reset the installation section so that it is located below the discharge end and return to S2.

[0146] The present invention provides a method for tightening bolts between disks of a large disk-to-diameter ratio compressor. Since the tightening method is implemented by the tightening device described in any one of the first aspects, the tightening method includes all the beneficial effects of the tightening device, which will not be repeated here.

[0147] Another embodiment of the second aspect of the present invention, as Figure 6-7 Position 1: The installation section is concentric with the blanking nozzle to ensure accurate feeding of the nut; Position 2: The transmission section rotates, and the installation section and the second arm body do not interfere with the bolt; Position 3: The transmission section and the rotating section locate the bolt position, and the installation section is concentric with the bolt to be tightened; Specifically, the steps include:

[0148] Preliminary step: The adjustment table 101 is rotated by the adjustment motor 1011, and an angle sensor is installed on the adjustment table 101 to read the current rotation angle and set its Z axis to zero. The 360-degree circumference is indexed by the position of the bolt to be tightened, and the bolt connection status corresponding to the indexed angle is stored;

[0149] S1: Output torque calibration. The tightening gun in the tightening gun module can output a range of torque. Since the tightening torque output by the tightening gun must pass through gear transmission before being transmitted to the tightening sleeve, this will cause torque loss due to gear transmission losses. Therefore, torque calibration is required. Before tightening begins, the output torque and angle of rotation at the tightening sleeve are measured to obtain the functional relationship between input torque and output torque. The input torque can then be adaptively adjusted according to the required output torque. During actual tightening, the torque output is intelligently and accurately output based on the corresponding relationship between torque and angle of rotation.

[0150] S2: Identification control module calibration. The identification control module is powered on and the axis marking line on the tightening sleeve is marked in the captured image information. This position is automatically calibrated as the image centerline, that is, the axis of the tightening sleeve is the reference axis of the vision module. Due to installation position differences, it is not possible to precisely install the camera mounting base in the middle of the mounting arm. Therefore, the bolt position is calibrated before each use to determine the installation tilt angle deviation. By processing the image, the bolt position is accurately identified.

[0151] S3: The equipment is installed on the compressor, such as Figure 7As shown, the mounting arm is in the retracted position, and the circumferential grooves of the nut indexing turntable are filled with the nuts to be tightened. The device is hoisted directly above the compressor using a lifting ring. With manual assistance, it is slowly lowered until the attachment base and the rear flange of the rotor disc are in contact. The device is then secured to the compressor using hardened cylindrical pins and a locking assembly.

[0152] S4: Nut supply, e.g. Figure 7 As shown, the mounting arm is in the retracted position, with the tightening sleeve concentrically aligned with the nut automatic restraint tube. The nut plate rotation motor then drives the nut plate 21 to rotate and automatically align with the nut delivery tube. Nuts stored on the nut plate drop into the nut delivery tube via the nut plate stepper restraint plate. The tightening sleeve then begins to rotate frequently, rotating forward and reverse, tightening the self-locking nut and aligning it with the tightening sleeve in twelve directions. A camera mounted on the mounting arm automatically determines whether the nut has accurately entered the tightening sleeve.

[0153] S5: The mounting arm is unfolded to position 1, and the motor is driven to make the mounting arm coupling drive the inner arm to unfold the inner arm. The outer arm is unfolded by the mounting arm outer arm unfolding motor. The circumferential worm gear angle and the rotation angle of the inner and outer arms are solved by the plane degree of freedom posture conversion. The robot joints perform inverse operations and calculate the spatial posture of the unfolded position according to the operating space;

[0154] S6: The mounting arm is lowered to position 2. Based on the posture calculation results, the L-shaped tightening device is lowered by the cam lifting module so that the mounting arm does not mechanically interfere with the bolts to be tightened during its expansion.

[0155] S7: The mounting arm is unfolded to position three. The motor is driven to cause the mounting arm coupling to drive the inner arm to unfold the inner arm. The outer arm is unfolded by the mounting arm outer arm unfolding motor. The circumferential worm gear angle and the rotation angles of the inner and outer arms are solved through the plane degree of freedom posture conversion. The robot joint performs inverse calculations and solves the spatial posture of the unfolded position three according to the operating space. At this time, the tightening sleeve is located directly above the bolt to be tightened.

[0156] S8: Visual positioning of the mounting arm. Due to the mismatch between the inside and outside, the initial deployed position of the mounting arm is aligned with the bolt to be tightened. Therefore, a camera is used to initially locate the mounting arm. The camera uses a machine learning model to determine whether the tightening head is aligned with the bolt. If the alignment deviation exceeds the allowable deviation of the equipment operation, the deviation angle is calculated based on the image captured by the camera and converted into the rotational displacement of the circumferential rotation module, thus achieving automatic alignment.

[0157] The visual recognition module 5 records the working screen of the recording device, marks the bolt positions using label software, and imports it into the neural network model in the form of a dataset; the neural network model uses a fast-RCNN target recognition and detection network with MobileNet as the backbone to establish an association model between image information and centerline analog quantities, and imports it into the host computer for calculation, and then the host computer completes the automatic positioning of the first bolt by controlling the rotation of the positioning motor 1011.

[0158] S9: The mounting arm is raised and screwed into place. The mounting arm is raised using the cam lifting module. During the raising process, the matching of the tightening sleeve speed and the cam lifting module needs to be set. The speed setting is related to the pitch and satisfies a functional relationship. Then, using the power transmission system, the tightening gun module applies torque by tightening the spline shaft and transmits the torque through the gear transmission. The outer circle of the tightening sleeve is designed with a gear-like structure, so that the outer arm transmission gear meshes with the outer circle of the tightening sleeve to transmit the torque of the tightening sleeve. During the tightening process, the angle sensor reads the current angle of the adjustment table and confirms the corresponding indexing bolt status. The status of the indexing bolt is updated in real time based on the information returned by the tightening gun controller after the tightening task is completed. It is visualized in the form of opencv to complete the automatic solution of the current position of the device. The upper computer software records the tightening status of the circular array bolts in real time and marks them.

[0159] S10: The mounting arm is lowered to position three. After the screwing is completed, the mounting arm is lowered to position three by the cam lifting module.

[0160] S11: The mounting arm is retracted to position 2. The motor is driven to cause the mounting arm coupling to drive the inner arm to retract the inner arm. The outer arm is retracted by the mounting arm outer arm deployment motor. The circumferential worm gear angle and the rotation angles of the inner and outer arms are solved through the plane degree of freedom posture conversion. The robot joint performs inverse calculations and solves the spatial posture of the deployment position 2 according to the operation space, so that the mounting arm is now in position 2.

[0161] S12: The mounting arm is raised to position 1. According to the posture calculation result, the L-shaped tightening device is raised by the cam lifting module so that the mounting arm is now in position 2.

[0162] S13: The mounting arm is retracted to its original position, and the motor is driven to cause the mounting arm coupling to drive the inner arm to retract the inner arm. The outer arm is retracted by the mounting arm outer arm deployment motor. The circumferential worm gear angle and the rotation angles of the inner and outer arms are calculated through the plane degree of freedom posture conversion. The robot joint performs an inverse operation and solves the spatial posture of the deployment position according to the operation space, so that the mounting arm is now in the original position.

[0163] S14: The device rotates circumferentially to the next tightening position. The device is rotated by the circumferential rotation module 4, and then the angle of the device is monitored in real time by the angle sensor and closed-loop feedback is sent to the input system. The closed-loop control of the circumferential rotation of the device is formed according to the displacement control of the circumferential rotation module motor and the angle sensor, thereby realizing high-precision rotation control of the device.

[0164] S15: The nuts are screwed in and tightened, and steps S4 to S14 are repeated until all nuts are screwed in and tightened;

[0165] S16: Nut force limiting, repeating steps S5-S12, completing the torque limiting of all nuts according to the process requirements, i.e., the bolt tightening sequence and tightening torque;

[0166] S17: Circular inspection of the nut status: The device is rotated 360 degrees in a circumferential direction by the circumferential rotation module, and the bolt tightening status is identified by the camera installed on the mounting arm. If the nut tightening status is abnormal, steps S5 to S12 are repeated, and the abnormal nut is loosened and tightened again. Then, S17 is repeated to complete the subsequent steps of the tightening method.

[0167] S18: Disassemble and assemble the equipment, remove the quenched cylindrical pin and locking assembly, lift and remove the device with manual assistance, use the equipment lifting ring to lift the equipment, and complete the compressor bolt assembly.

[0168] In the description of the present invention, it should be understood that the terms "longitudinal", "transverse", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0169] The embodiments described above are merely descriptions of preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Without departing from the spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by persons skilled in the art should fall within the scope of protection defined by the claims of the present invention.

Claims

1. A bolt tightening device for large-disc-diameter ratio compressor discs, characterized in that: include: A hoisting platform, which can be moved in a lifting manner within the cavity of the compressor by an external hoisting machine, and an adjustment platform is rotatably provided on the hoisting platform; A supply portion capable of storing a plurality of nuts, the supply portion being provided with a discharge end, the discharge end penetrating the adjustment table from top to bottom, a loading plane being provided at the bottom of the adjustment table, and a port of the discharge end being located within the loading plane; The driving portion, the adjustment platform has an axis, and the driving portion is eccentrically arranged on the adjustment platform, the driving portion is provided with a driving end, and the driving end protrudes downward from the loading plane; The mounting arm has a mounting section and a transmission section at both ends, the mounting section being used to load nuts dropped from the discharge end onto a loading plane and to mount the nuts on bolts in the compressor cavity, the transmission section being connected to the driving end to drive the mounting section to move between the discharge end and the plurality of bolts and to drive the mounting section to rotate; the mounting arm is further provided with a steering knuckle located between the mounting section and the transmission section, the steering knuckle being used to adjust the linear distance between the mounting section and the transmission section; an identification control module, for identifying the discharge end and the bolt, and controlling the driving part and the supply part, wherein the identification control module is provided on the mounting arm; The driving end includes a first driving shaft and a second driving shaft; The mounting arm comprises: a first arm body and a second arm body connected via the steering knuckle; The second drive shaft has a center point located on the loading plane where it passes through the loading plane, and the center point, the discharge end, and the midpoint of the loading plane are not collinear; and the position of the discharge end on the loading plane is designed according to the following rules: ； in, is the radius of the adjustment table, and the center of the circle is the midpoint of the adjustment table. The center point of the discharge end is determined on the circumference of the radius. x is the x-coordinate value of the x-axis installation section in any direction with the center point of the adjustment table as the coordinate origin. y is the y-coordinate value of the installation section in the direction perpendicular to the x-axis with the center point of the adjustment table as the coordinate origin. is the rotation angle of the adjustment table, is the rotation angle of the second drive shaft, is the angle between the first arm and the second arm, is the midline length of the first arm, is the midline length of the first arm, It is the plane distance between the second drive shaft and the center of the adjustment table.

2. The bolt tightening device for large-disc-diameter-ratio compressor discs according to claim 1, characterized in that: The line connecting the mounting knuckle and the steering knuckle and the line connecting the transmission knuckle and the steering knuckle have an angle, and the angle changes with the straight-line distance; and / or The hoisting platform is provided with a plurality of hoisting rings along the circumference of the axis, and each of the hoisting rings is connected to a rope of an external hoisting machine; and / or The portion of the driving portion other than the driving end and the supply portion are both located on a side of the loading plane facing away from the mounting arm.

3. The bolt tightening device for large-disc-diameter-ratio compressor discs according to claim 1, characterized in that: The mounting joint is mounted on an end of the second arm away from the steering knuckle; The transmission joint is installed at one end of the first arm body away from the steering knuckle.

4. The bolt tightening device for large-disc-diameter-ratio compressor discs according to claim 3 is characterized in that: The first arm and the second arm are both hollow, and are provided with a plurality of transmission wheels arranged linearly and connected to each other inside, and the steering knuckle is provided with a steering wheel connected to the transmission wheels of the first arm and the second arm respectively; The mounting section is fixedly connected to the transmission wheel of the second arm; The transmission joint is rotatably connected to the transmission wheel of the first arm body.

5. The bolt tightening device for large-disc-diameter-ratio compressor discs according to claim 4, characterized in that: The first drive shaft has a hollow portion along the axial direction, and the second drive shaft is coaxially arranged in the hollow portion; The first drive shaft is fixedly connected to the transmission joint to drive the mounting arm to rotate circumferentially along the axis; The second drive shaft shown passes through the transmission joint and is fixedly connected to the transmission wheel to drive the mounting joint to rotate through the transmission wheel and the steering wheel; as well as The mounting arm further includes a steering assembly, which is mounted on the first arm body, and the output shaft of the steering assembly is connected to one end of the second arm body close to the transmission joint to drive the second arm body to rotate circumferentially with the steering knuckle as the center.

6. The bolt tightening device for inter-disk of a compressor with a large disk-diameter ratio according to claim 5, characterized in that: The steering assembly comprises: A motor is provided on the first arm; A linkage rod, the ends of which are respectively connected to the output end of the motor and the output shaft, so as to transmit the power generated by the motor to the output shaft and drive the output shaft to move circumferentially with the steering knuckle as the center; A round hole is provided at the connection between the linkage rod and the output shaft, and the round hole is slidably connected to the side wall of the output shaft; and / or the axis of the linkage rod is perpendicular to and intersects with the output end of the motor and the axis of the output shaft.

7. The bolt tightening device for large-disc-diameter-ratio compressor discs according to claim 5, characterized in that: The adjustment platform is used to drive the installation arm connected to the driving part to move circumferentially with the axis as the center, so as to screw nuts on the bolts distributed circumferentially in the cavity of the compressor in sequence; The steering assembly is used to cooperate with the adjustment platform and the first drive shaft, so that the mounting joint can move circumferentially with the steering knuckle and / or the shaft center and / or the mounting joint as the center to approach the bolt, or the mounting joint can move circumferentially with the steering knuckle and / or the mounting joint as the center to approach the discharge end; The driving portion is used to drive the first driving shaft and / or the second driving shaft to rotate, and / or drive the first driving shaft and the second driving shaft to move synchronously along the axial direction.

8. The bolt tightening device for inter-disk of a compressor with a large disk-diameter ratio according to claim 5, characterized in that: The driving unit includes: a coupling, rotatably connected to the second drive shaft and fixedly connected to the outer wall of the first drive shaft; a tightening gun, fixed on the coupling, wherein the rotating shaft of the tightening gun is connected to the second drive shaft; A cam module is mounted on the adjustment table, wherein a transmission plate of the cam module is rotatably connected to the outside of the first drive shaft to drive the first drive shaft to move along the axial direction; The motor module is mounted on the adjustment platform, and the output end of the motor module is slidably connected to the outside of the first drive shaft to drive the first drive shaft to rotate.

9. A tightening method based on the tightening device according to any one of claims 1 to 8, characterized in that: The steps include: S1, start the driving part to drive the installation joint and the transmission joint to rotate and move longitudinally. At this time, rotate the steering knuckle so that the installation joint and the transmission joint are close to each other and are below the loading plane, and the installation joint is longitudinally corresponding to the discharge end; S2, the supply unit selects any one of the multiple stored nuts and drops it out through the discharge end, and drops it into the installation section; S3, by rotating the transmission joint, the mounting arm rotates to a certain angle, the steering knuckle is reversed to move the mounting joint and the transmission joint away from each other, and the mounting arm is unfolded, so that the mounting joint with the nut is close to the bottom of the bolt to be fixed; S4, the recognition control module identifies the position of the bolt to be tightened and completes the longitudinal correspondence between the nut and the bolt; S5, the installation section drives the nut to rotate, and driven by the rotating section, the nut and the nut are moved upwards to contact the bolt until the threaded connection is completed; S6, reset the installation section so that it is located below the discharge end and return to S2.

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