Tightening and unscrewing equipment and method for blind cavity nut

Abstract

The invention relates to the technical field of nut disassembly and assembly, and discloses blind cavity nut tightening and loosening equipment which comprises a frame and a supporting plate, an outer shaft is installed at the bottom of the frame, an offset head is arranged at the tail end of the outer shaft, and a swing mechanism is arranged on one side of the frame; a tightening gun is installed on the supporting plate, the output end of the tightening gun is connected with an inner shaft, and the inner shaft is movably arranged in the outer shaft in a penetrating mode. The nut is pre-tightened by the inner shaft through torque transmission, and the nut is tightened by the outer shaft in a manner of combining angles and torques, so that the tightening precision of the nut and the consistency and stability of tightening torques of different nuts are improved; the invention further discloses a screwing and unscrewing method of the blind cavity nut, the screwing efficiency of the nut can be greatly improved through the method, and it is ensured that the screwing torque meets the screwing torque precision requirement.

Description

Technical Field

[0001] The invention relates to the technical field of nut disassembly and assembly, and in particular to a device and method for tightening and loosening a blind cavity nut. Background Art

[0002] The tightening process of the nut is directly related to the reliability and safety of the connection, especially in situations where the assembly space is small, the tightening process is complicated, and high tightening precision is required, such as in blind cavities such as engine shaft cavities, where the operation of disassembling and assembling the nut is relatively cumbersome; currently, the tightening and loosening of the nut in the blind cavity is mostly done manually using a wrench, but in the case of a small internal space, it is not only difficult to effectively tighten the nut, the operation is inconvenient, and it is easy to cause bumps and damage to the inside of the blind cavity.

[0003] In order to solve the above problems, a Chinese patent with application number CN2022115221957 discloses a device for disassembling and assembling connecting nuts in the shaft cavity of an aircraft engine, which is suitable for tightening and loosening nuts in a smaller assembly space. The device is connected to an offset head through a tightening gun, and a gear-type sleeve at the end of the offset head tightens and loosens the nut; however, the tightening accuracy of the device is low, and often fails to meet the accuracy requirements of the thread tightening torque on aviation equipment (generally ±5%, or even ±3%); if the tightening torque is less than the required torque lower limit, it is easy to cause relative slippage of the connected parts when subjected to force; if the tightening torque is greater than the required torque upper limit, it is easy to cause plastic deformation and excessive stretching of the bolt. Both situations will cause failure of the threaded connection.

[0004] The reasons why the tightening torque of the above device does not meet the tightening torque accuracy requirements are: (1) The gear manufacturing accuracy, tooth side clearance, elastic deformation, etc. of the gear set inside the offset head will affect the final transmitted torque; and the tightening gun and the offset head are connected by a longer shaft, which will introduce additional torsional deformation when subjected to force, affecting the stability of the torque output; (2) Gear meshing friction, friction between gears and bearings, friction between bolts and nuts, and friction between connected parts and nuts will convert energy into heat energy, resulting in deviations in the actual transmitted torque; (3) The tightening process does not adopt the torque + angle control method, and the control system does not establish a mathematical model for torque error compensation.

[0005] Based on this, we propose a blind cavity nut tightening and loosening device and method, which is suitable for occasions with narrow assembly space, complex tightening process (such as tightening, loosening, and re-tightening), and high tightening accuracy. Summary of the invention

[0006] The purpose of the present invention is to overcome the deficiencies in the prior art and provide a device and method for tightening and loosening blind cavity nuts, which uses a swing tightening method combined with a torque plus angle method to tighten the nuts, eliminate the source of errors, and improve the tightening accuracy of the nuts and the consistency and stability of the tightening torques of different nuts.

[0007] In order to achieve the above object, the technical solution adopted by the present invention is: In a first aspect, a device for tightening and loosening blind cavity nuts is provided, comprising a frame and a support plate that can be raised and lowered relative to the frame, an outer shaft is installed at the bottom of the frame, an offset head that can be flipped relative to the outer shaft is provided at the end of the outer shaft, and a swing mechanism for driving the outer shaft to swing horizontally is provided on one side of the frame; the offset head comprises a box body connected to the outer shaft, a sleeve gear and a driving gear for driving the sleeve gear to rotate are installed inside the box body, and one end of the driving gear and the sleeve gear both extend to the outside of the box body; a tightening gun is installed on the support plate, and the output end of the tightening gun is connected to an inner shaft for driving the driving gear to rotate, and the inner shaft is movably inserted into the outer shaft.

[0008] Optionally, a lifting plate, a sliding plate, a rotating plate and a fixed plate are sequentially arranged below the frame; a rotating mechanism for driving the rotating plate to rotate is arranged on the fixed plate, a translation mechanism for driving the sliding plate to move in a horizontal direction is arranged on the rotating plate, and a lifting mechanism for driving the lifting plate to move along the axial direction of the outer shaft is arranged on the sliding plate; the frame is mounted on the lifting plate, and the outer shaft passes through the lifting plate, the sliding plate, the rotating plate and the fixed plate in sequence.

[0009] Optionally, the frame includes a base plate connected to the swing mechanism, a gantry is fixedly mounted on the base plate, and the support plate is located on the inner side of the gantry.

[0010] Optionally, the swing mechanism includes a second telescopic component, a rocker arm, a rotating shaft and a bracket, the bracket is fixedly mounted on the lifting plate, one end of the rotating shaft is rotatably connected to the bracket, and the other end is fixedly connected to the base plate; the second telescopic component is connected to the lifting plate, the rocker arm is perpendicular to the rotating shaft, and one end of the rocker arm is rotatably connected to the output end of the second telescopic component, and the other end is fixedly connected to the rotating shaft.

[0011] Optionally, a ratchet assembly for limiting the one-way rotation of the sleeve gear is provided on the box body, and the ratchet assembly includes a ratchet and a shifting rod for reversing, the ratchet is connected to the sleeve gear, and one end of the shifting rod is connected to the reversing assembly.

[0012] Optionally, the reversing assembly includes a discharge motor and a spring arranged relatively on both sides of the frame, the output end of the discharge motor is connected to a roller, a first soft rope is wound around the roller, and the end of the first soft rope is connected to the left side of the lever; one end of the spring is connected to the frame, and the other end is connected to a second soft rope, and the end of the second soft rope is connected to the right side of the lever.

[0013] Optionally, the offset head is rotatably connected to the outer shaft via an adapter, a movable sleeve is provided on the sliding sleeve of the outer shaft, a connecting rod is rotatably installed on the movable sleeve, one end of the connecting rod is rotatably connected to the offset head, and a driving component for driving the movable sleeve to move axially is provided on the frame.

[0014] Optionally, the driving assembly includes a driving plate located below the frame, the frame is provided with a first telescopic assembly for driving the driving plate to move axially along the outer shaft, and the driving plate is fixedly connected to the movable sleeve via a pull rod.

[0015] In a second aspect, a method for tightening and loosening a blind cavity nut is provided, using the device for tightening and loosening a blind cavity nut according to the first aspect, comprising the following steps: S1, the frame moves downward so that the offset head at the end of the outer shaft enters the blind cavity; S2, the offset head enters the blind cavity and flips to a horizontal state, and then the support plate moves down so that the end of the inner shaft and the driving gear are matched and docked; S3, after the sleeve gear of the offset head is aligned with the nut to be tightened, the tightening gun drives the sleeve gear to rotate through the inner shaft to pre-tighten the nut; S4. After pre-tightening, the swing mechanism drives the outer shaft to swing, so that the offset head rotates around the axis of the nut to tighten the nut; S5. After the nut is tightened, the ratchet assembly changes direction, the tightening gun drives the sleeve gear to rotate in the opposite direction through the inner shaft, and the swing mechanism drives the offset head to swing in the opposite direction through the outer shaft to loosen the nut; S6. After the nut is loosened to the specified torque, the ratchet assembly changes direction again, drives the offset head to move through the inner shaft and the outer shaft, and tightens the nut again; S7. Repeat steps S3 to S6 in sequence to complete the installation of the remaining nuts in the blind cavity.

[0016] Optionally, the process of aligning the sleeve gear of the offset head with the nut to be tightened is achieved through the linkage cooperation between the rotating mechanism, the translation mechanism and the lifting mechanism.

[0017] Compared with the prior art, the present invention has the following beneficial effects: (1) In the present invention, the inner shaft is driven to rotate by the tightening gun, and the torque is used to drive the sleeve gear of the offset head to rotate, so as to pre-tighten the nut to be tightened. The outer shaft is driven to rotate by the swing mechanism to drive the offset head to swing as a whole, and the nut is tightened by combining the angle and torque, thereby improving the tightening accuracy of the nut and the consistency and stability of the tightening torque of different nuts. (2) In the present invention, the reversing of the ratchet assembly is achieved through the reversing assembly, ensuring that the device can smoothly tighten and loosen the nut, and the switching efficiency is high and the stability is good; (3) In the present invention, the frame can be raised and lowered, rotated and moved horizontally, thereby driving the offset head to quickly align with the nut to be tightened. The offset head can be flipped longitudinally and can penetrate into a narrow space to perform a complex tightening process; (4) In the disassembly and assembly method proposed in the present invention, the tightening gun drives the inner shaft to pre-tighten the nut through the offset head, and the swing mechanism drives the outer shaft to swing the offset head, thereby tightening the nut in a manner combining angle and torque, and then the two rotate in opposite directions to loosen the nut and finally tighten it again; this method can ensure that the tightening torque meets the tightening torque accuracy requirements, thereby improving the quality and efficiency of nut tightening. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 1 is a schematic structural diagram of a device for tightening and loosening a blind cavity nut according to an embodiment of the present invention; Figure 2 is a side structural schematic diagram of a device for tightening and loosening blind cavity nuts in an embodiment of the present invention; Figure 3 is a schematic structural diagram of a swing mechanism in an embodiment of the present invention; Figure 4 is a schematic diagram of the structure of the framework in an embodiment of the present invention; Figure 5 is a schematic structural diagram of an offset head in an embodiment of the present invention; Figure 6 is a schematic diagram of the internal structure of the offset head in an embodiment of the present invention; Figure 7 is a schematic diagram of the structure of a drive assembly in an embodiment of the present invention; Among them, 1, frame; 101, bottom plate; 102, gantry; 103, support plate; 2, tightening gun; 201, inner shaft; 3, outer shaft; 4. offset head; 401. box body; 402. driving gear; 403. sleeve gear; 404. transition gear; 405. ratchet assembly; 406. endoscope probe; 501, adapter; 502, connecting rod; 503, moving sleeve; 504, pull rod; 505, driving assembly; 551, first telescopic assembly; 552, driving plate; 553, first guide rod; 6. Swing mechanism; 601. Second telescopic assembly; 602. Swing rod; 603. Rotating shaft; 604. Bracket; 7. Fixed plate; 8. Rotating plate; 9. Sliding plate; 10. Lifting plate; 11. Engine workpiece simulation device; 12. First gear; 13. Second gear; 14. Third telescopic assembly; 15. Top plate; 16. Second guide rod; 17. Driving motor; 18. Screw rod; 19. Screw-on part; 20. Pulley assembly; 21. Winding motor; 22. Spring; 23. Winding roller. DETAILED DESCRIPTION

[0019] The present invention will now be further described in detail with reference to the accompanying drawings and embodiments. These drawings are simplified schematic diagrams that only illustrate the basic structure of the present invention in a schematic manner, and therefore only show the components related to the present invention. Embodiment 1

[0020] like Figure 1 and Figure 2 As shown, a device for tightening and loosening blind cavity nuts comprises a fixed plate 7, a rotating plate 8, a sliding plate 9 and a lifting plate 10 which are arranged in sequence from bottom to top, a frame 1 is installed on the lifting plate 10, a support plate 103 which can be lifted and lowered relative to the frame 1 is installed on the inner side of the frame 1, an outer shaft 3 is fixedly installed on the bottom of the frame 1, and an offset head 4 which can be flipped relative to the outer shaft 3 is arranged at the end of the outer shaft 3; a tightening gun 2 is fixedly installed on the support plate 103, the output end of the tightening gun 2 is connected to the inner shaft 201, and the inner shaft 201 is movably inserted into the outer shaft 3.

[0021] As mentioned above, the fixed plate 7 is provided with a rotating mechanism for driving the rotating plate 8 to rotate horizontally, the rotating plate 8 is provided with a translation mechanism for driving the sliding plate 9 to move in the horizontal direction, and the sliding plate 9 is provided with a lifting mechanism for driving the lifting plate 10 to move along the axial direction of the outer shaft 3, and the outer shaft 3 sequentially passes through the lifting plate 10, the sliding plate 9, the rotating plate 8 and the fixed plate 7. A swing mechanism 6 for driving the outer shaft 3 to swing horizontally is provided on one side of the frame 1, and the swing mechanism 6 is installed on the lifting plate 10, and can be lifted and translated synchronously with the frame 1.

[0022] Among them, the frame 1 can not only be lifted and lowered axially, rotated around the axial direction and moved horizontally synchronously with the lifting plate 10, but also can swing horizontally relative to the lifting plate 10 under the action of the swing mechanism 6, and the support plate 103 can be lifted and lowered relative to the frame 1 to drive the inner shaft 201 to dock with the offset head 4, and pre-tighten the nut through torque.

[0023] Specifically, an engine workpiece simulation device 11 is provided below the fixing plate 7, and includes an engine simulation part, bolts and nuts, and a static torque sensor, and is used to simulate the tightening and loosening of the bolts and nuts inside the engine blind cavity by the device.

[0024] First, the frame 1 moves downward, and the offset head 4 is driven by the outer shaft 3 to enter the blind cavity of the engine. Then, the offset head 4 is flipped from a state parallel to the outer shaft 3 to a horizontal state (perpendicular to the outer shaft 3). Then, the linkage between the rotating mechanism, the translation mechanism and the lifting mechanism is used to align the offset head 4 with the nut to be tightened, and then the nut tightening process is completed through the equipment.

[0025] During the installation process, the nut is first pre-tightened (using torque) using the tightening gun 2, the inner shaft 201 and the offset head 4, and then the nut is tightened (using a combination of angle and torque) through the swing mechanism 6, the outer shaft 3 and the offset head 4. After tightening, the inner shaft 201 and the outer shaft 3 cooperate with each other to loosen the nut, and finally the nut is tightened to complete the tightening installation of a nut.

[0026] In the process of removing the nut, the nut can be loosened first by the swing mechanism 6, the outer shaft 3 and the offset head 4, and then the nut can be removed from the bolt by the tightening gun 2, the inner shaft 201 and the offset head 4.

[0027] like Figure 5 and Figure 6 As shown, the offset head 4 includes a box body 401, a driving gear 402, a sleeve gear 403 and a plurality of transition gears 404. The driving gear 402 and the sleeve gear 403 are rotatably mounted at both ends of the box body 401, respectively, and a plurality of transition gears 404 are arranged between the two. The driving gear 402, the sleeve gear 403 and the transition gear 404 are meshed with each other and arranged in a straight line, that is, the torque of the driving gear 402 can be transmitted to the sleeve gear 403 through the transition gear 404, thereby realizing the rotation drive of the sleeve gear 403.

[0028] As described above, the box body 401 is composed of two upper and lower end covers connected together, and the gear is rotatably installed between the upper and lower end covers. The shaft end of the driving gear 402 and the sleeve end of the sleeve gear 403 both extend to the outside of the box body 401. When the offset head 4 is flipped to a horizontal state, the shaft end of the driving gear 402 protrudes from the top of the box body 401, and the sleeve end of the sleeve gear 403 protrudes from the bottom of the box body 401.

[0029] Among them, one end of the box body 401 close to the driving gear 402 is rotatably connected to the outer shaft 3. An endoscope probe 406 is also provided at the bottom of the box body 401. A display device is provided on the outside to assist the staff in observing the tightening condition in the blind cavity. The inner shaft 201 is used to drive the driving gear 402 to rotate.

[0030] An inner angle groove is formed at the shaft end of the driving gear 402, and the end of the inner shaft 201 is in a shape corresponding to the inner angle groove; after the support plate 103 moves downward, the end of the inner shaft 201 is embedded in the inner angle groove, thereby transmitting the torque of the tightening gun 2 to the driving gear 402 through the inner shaft 201, and then the driving gear 402 drives the sleeve gear 403 to rotate through the transition gear 404.

[0031] In addition, a ratchet assembly 405 is also provided on the top of the box body 401, and the ratchet assembly 405 is used to control the unidirectional rotation of the sleeve gear 403 to ensure that the torque and torque can be smoothly applied to the nut; and the ratchet assembly 405 can also achieve reversal through the reversing assembly, thereby facilitating the tightening and loosening of the nut (i.e. tightening and loosening).

[0032] like Figure 3 As shown, the frame 1 includes a bottom plate 101 connected to the swing mechanism 6, a gantry 102 is fixedly mounted on the bottom plate 101, and a support plate 103 is located on the inner side of the gantry 102. Both sides of the support plate 103 are slidably connected to the inner side of the gantry 102 through slide rails, an electric cylinder is mounted on the gantry 102, and the output end of the electric cylinder is fixedly connected to the support plate 103.

[0033] The swing mechanism 6 includes a second telescopic component 601, a rocker arm 602, a rotating shaft 603 and a bracket 604. The bracket 604 is fixedly installed on the lifting plate 10. One end of the rotating shaft 603 is rotatably connected to the bracket 604, and the other end is fixedly connected to the base plate 101. The second telescopic component 601 is connected to the lifting plate 10 through a support. The rocker arm 602 is perpendicular to the rotating shaft 603, and one end of the rocker arm 602 is rotatably connected to the output end of the second telescopic component 601, and the other end is fixedly connected to the rotating shaft 603.

[0034] The second telescopic component 601 can adopt an electric cylinder, and the telescopic output end thereof can drive the rotating shaft 603 to rotate around its own axis through the rocker rod 602, and the rotating shaft 603 is fixedly connected to the base plate 101, thereby realizing the swing of the frame 1, and the frame 1 then drives the outer shaft 3 to swing horizontally, so that the offset head 4 rotates horizontally around the axis of the sleeve gear 403, thereby ensuring that the tightening torque of the equipment meets the tightening torque accuracy requirements by combining torque and angle.

[0035] Among them, the bracket 604 adopts a gantry structure, the rotating shaft 603 and the outer shaft 3 are parallel to each other, the upper end of the rotating shaft 603 is rotatably connected to the bracket 604, the middle part can be connected to the bracket 604 through a bearing, etc., and the lower end is fixedly connected to the bottom plate 101 of the frame 1; that is, the frame 1 as a whole is connected to the lifting plate 10 through the rotating shaft 603 and the bracket 604, and the second telescopic component 601 drives the rotating shaft 603 to rotate around its own axis through the rocker 602, so that the frame 1 and the components thereon can swing horizontally around the axis of the rotating shaft 603, and at the same time drive the offset head 4 to swing around the axis of the sleeve gear 403 or the nut to be tightened, thereby completing the tightening or loosening operation of the nut on the bolt.

[0036] Working principle: First, all nuts to be tightened are installed on the bolts, the frame 1 moves downward, and the offset head 4 is driven by the outer shaft 3 to longitudinally enter the blind cavity of the engine, and then the offset head 4 is flipped to a horizontal state, and the position of the nut is observed through the endoscope probe 406, and then the sleeve end of the sleeve gear 403 on the offset head 4 is aligned with the nut to be tightened (that is, the sleeve is sleeved on the nut) by the linkage between the rotating mechanism, the translation mechanism and the lifting mechanism; First, the nut is pre-tightened by the tightening gun 2, the inner shaft 201 and the offset head 4, and then the nut is tightened by the swing mechanism 6, the outer shaft 3 and the offset head 4. After tightening, the inner shaft 201 and the outer shaft 3 cooperate with each other to loosen the nut, and finally the nut is tightened to complete the tightening installation of a nut; during the pre-tightening and tightening process, the nut moves downward along the axis of the bolt, and at this time, the lifting plate 10 also moves downward accordingly. Similarly, when loosening, the nut moves upward along the axis of the bolt, and the lifting plate 10 also moves upward in coordination; When removing the nut, first loosen the nut, and the nut will move upward along the axis of the bolt. At this time, the lifting plate 10 will also move upward accordingly until the nut is completely loosened to facilitate subsequent removal. Embodiment 2

[0037] like Figure 1 , Figure 2 , Figure 3 , Figure 4 and Figure 5 As shown, based on the first embodiment, the present invention further discloses the specific structures of the rotating mechanism, the translating mechanism and the lifting mechanism.

[0038] The rotating mechanism includes a connecting part, a first gear 12 and a second gear 13. The fixed plate 7 and the rotating plate 8 are rotatably connected through the connecting part. The first gear 12 is fixedly sleeved on the outer side of the connecting part. The second gear 13 is rotatably installed on the rotating plate 8 and is driven to rotate by a motor. The first gear 12 and the second gear 13 are meshed with each other, and the radial dimension of the first gear 12 is greater than the radial dimension of the second gear 13.

[0039] The connecting part is equivalent to a bearing, whose inner ring is fixedly connected to the rotating plate 8, the outer ring is fixedly connected to the fixed plate 7, and the first gear 12 is fixedly sleeved on the outer ring; when the motor drives the second gear 13 to rotate, based on the meshing action, the second gear 13 will drive the rotating plate 8 to rotate around the axis of the first gear 12, thereby facilitating the offset head 4 to align with the nuts at different positions on the circumferential side.

[0040] The translation mechanism includes a third telescopic component 14, which is fixedly mounted on the rotating plate 8, and the output end of the third telescopic component 14 is connected to the sliding plate 9. The sliding plate 9 is slidably connected to the rotating plate 8 through a guide rail slider, and the third telescopic component 14 can also use an electric cylinder. As its output end is extended and retracted, the sliding plate 9 moves horizontally synchronously along the guide rail.

[0041] The lifting mechanism includes a second guide rod 16, a drive motor 17, a screw rod 18 and a screw-on component 19. The screw-on component 19 is fixedly mounted on the lifting plate 10. One end of each of the second guide rods 16 is fixed on the sliding plate 9, and the other end is fixedly connected through the top plate 15. The drive motor 17 is fixedly mounted on the top plate 15. One end of the screw rod 18 is connected to the output end of the drive motor 17, and the other end is rotatably connected to the sliding plate 9. The screw rod 18 is screwed through the screw-on component 19.

[0042] Among them, the second guide rod 16, the screw rod 18 are parallel to the inner shaft 201 and the outer shaft 3, and the driving motor 17 drives the screw rod 18 to rotate. Based on the screw connection relationship, the screw-on component 19 can drive the lifting plate 10 to reciprocate along the axis of the screw rod 18, thereby realizing the lifting function. The screw-on component 19 here usually adopts a nut.

[0043] In order to ensure the stability of lifting, four second guide rods 16 are provided and distributed around the frame 1, and the second guide rods 16 are connected to the lifting plate 10 through linear bearings.

[0044] As mentioned above, the frame 1 is installed on the lifting plate 10. Through the coordinated action of the rotating mechanism, the translation mechanism and the lifting mechanism, it can not only realize the translation, rotation and lifting functions, but also achieve the purpose of quickly aligning the nut to be tightened. Moreover, under the action of the swing mechanism 6, the frame 1 can also drive the outer shaft 3 to rotate around the rotating shaft 603, so that the offset head 4 tightens the nut in a combination of torque and angle.

[0045] One end of the outer shaft 3 is fixedly connected to the base plate 101, and the other end passes through the lifting plate 10, the sliding plate 9, the rotating plate 8 and the fixed plate 7. In order to ensure that the outer shaft 3 can swing smoothly, avoidance holes are opened on the lifting plate 10, the sliding plate 9, the rotating plate 8 and the fixed plate 7. Embodiment 3

[0046] Based on the first embodiment, the present invention further discloses the related structures of the ratchet assembly 405 and the reversing assembly.

[0047] like Figure 5 and Figure 6 As shown, the ratchet assembly 405 includes a ratchet and a lever. The ratchet is connected to the sleeve gear 403 and is used to limit the one-way rotation of the sleeve gear 403 to facilitate tightening or loosening the nut; the lever is used to change the direction in which the sleeve gear 403 is allowed to rotate, and one end of the lever is connected to the reversing assembly.

[0048] As mentioned above, the direction of the ratchet can be changed by adjusting the position of the lever. Since this structure is a prior art and is equivalent to a ratchet wrench, it will not be described in detail here. The reversing assembly here is used to adjust the position of the lever, thereby controlling the direction of the ratchet, making it convenient for the offset head 4 to loosen or tighten the nut in the blind cavity.

[0049] One end of the lever is rotatably connected to the main body of the ratchet assembly 405, and the other end is relatively provided with two holes for connecting the reversing assembly; for example, when the end of the lever is rotated to the left, the positive rotation of the sleeve gear 403 can be prevented, so that the offset head 4 can tighten the nut; when the end of the lever is rotated to the right, the reverse rotation of the sleeve gear 403 can be prevented, so that the offset head 4 can loosen the nut.

[0050] like Figure 3 and Figure 4 As shown, the reversing assembly includes a winding discharge motor 21 and a spring 22, which are arranged on both sides of the frame 1 relatively to each other; the output end of the winding discharge motor 21 is connected to a winding roller 23, on which a first soft rope is wound, and the end of the first soft rope is connected to the hole on the left side of the lever; one end of the spring 22 is connected to the frame 1, and the other end is connected to a second soft rope, and the end of the second soft rope is connected to the hole on the right side of the lever.

[0051] The winding discharge motor 21 is fixed on the left side of the gantry 102, and a screw is fixedly installed on the right side of the gantry 102. The end of the screw is fixedly connected to the upper end of the spring 22, and the lower end of the spring 22 is fixedly connected to the second soft rope.

[0052] Specifically, the winding discharge motor 21 reels the first soft rope through the winding roller 23, and the first soft rope pulls the lever to swing to the left position, and the offset head 4 can rotate forward to tighten the nut; at the same time, the second soft rope on the right is pulled by hand, driving the spring 22 to extend and store elastic potential energy; after the winding discharge motor 21 unwinds the first soft rope through the winding roller 23, under the action of the elastic force of the spring 22, the lever swings to the right position again, and the offset head 4 can rotate in the opposite direction to loosen the nut.

[0053] Furthermore, in order to reduce the friction and wear between the soft rope and the equipment, a pulley assembly 20 is correspondingly arranged on the component along the path of the soft rope. The soft rope passes through the pulley of the pulley assembly 20, which can reduce friction and wear and play a guiding role; such as the pulley assembly 20 arranged on both sides of the gantry 102, and sensors for detecting the position of the soft rope are also arranged on both sides of the gantry 102 to ensure that the winding discharge motor 21 will not be over-reeled. Embodiment 4

[0054] like Figure 5 and Figure 7 As shown, based on the first embodiment, the present invention further discloses a structure for realizing the longitudinal flipping of the offset head 4 .

[0055] The offset head 4 is rotatably connected to the outer shaft 3 through an adapter 501. A movable sleeve 503 is slidably sleeved on the outer shaft 3. A connecting rod 502 is rotatably installed on the movable sleeve 503. One end of the connecting rod 502 is rotatably connected to the offset head 4, and a driving component 505 for driving the movable sleeve 503 to move axially is provided on the frame 1.

[0056] Among them, the upper end of the connecting rod 502 is rotatably connected to the lower end of the movable sleeve 503, and the lower end of the connecting rod 502 is rotatably connected to one end of the box body 401 close to the driving gear 402; the adapter 501 includes a sleeve body fixedly connected to the outer shaft 3, and the inner side of the sleeve body is rotatably connected to a rotating body through a pin shaft, and the pin shaft and the axis of the outer shaft 3 are perpendicular to each other, and the shaft end of the driving gear 402 passes through the rotating body.

[0057] When the movable sleeve 503 moves upward, the connecting rod 502 drives the offset head 4 to flip around the pin of the adapter 501 to a state parallel to the outer shaft 3. When the movable sleeve 503 moves downward, the connecting rod 502 drives the offset head 4 to flip to a horizontal state. At this time, the driving gear 402 is coaxial with the inner shaft 201.

[0058] The driving assembly 505 includes a first telescopic assembly 551, a driving plate 552 and a first guide rod 553; the first telescopic assembly 551 is fixedly installed on the base plate 101, the driving plate 552 is located below the base plate 101, the first guide rod 553 is slidably penetrated on the base plate 101, and a limit block is provided at the upper end of the first guide rod 553, and the lower end is fixedly connected to the driving plate 552, and the output end of the first telescopic assembly 551 passes through the base plate 101 and is fixedly connected to the driving plate 552.

[0059] Specifically, the first telescopic component 551 can drive the driving plate 552 to reciprocate along the axis of the first guide rod 553, and the driving plate 552 is fixedly connected to the movable sleeve 503 through the pull rod 504, that is, the movable sleeve 503 and the driving plate 552 can move synchronously under the drive of the first telescopic component 551.

[0060] Furthermore, the rear end of the driving plate 552 is connected to the first telescopic assembly 551 and the first guide rod 553, and the front end has a forked structure, which is sleeved on the outside of the outer shaft 3, and the pull rod 504 is fixed at the front end of the separated structure, so that the pull rod 504 and the outer shaft 3 are parallel to each other, ensuring the synchronization of the movement of the movable sleeve 503 and the driving plate 552.

[0061] In order to ensure that the moving sleeve 503 can slide smoothly along the outer shaft 3, two pull rods 504 are provided, which are relatively distributed on both sides of the outer shaft 3 to ensure that the force of the moving sleeve 503 is balanced.

[0062] In summary, the first telescopic component 551 can be an electric cylinder, and through the telescopic movement of its output end, the driving plate 552 and the pull rod 504 can drive the movable sleeve 503 to move axially along the outer shaft 3. Embodiment 5

[0063] On the basis of the first, second, third and fourth embodiments, the present invention further proposes a method for tightening and loosening a blind cavity nut, which can realize the tightening process of the nut in a narrow space.

[0064] A method for tightening and loosening blind cavity nuts comprises the following steps: firstly, all nuts are mounted on bolts inside the blind cavity of an engine, then an offset head 4 is inserted into the blind cavity, then the offset head 4 is flipped to a horizontal state, and then the sleeve gear 403 of the offset head 4 is aligned and sleeved on the nut to be tightened by utilizing the linkage cooperation among a rotating mechanism, a translation mechanism and a lifting mechanism; and then the nut is tightened onto the bolt by a process of pre-tightening, tightening, loosening and then tightening.

[0065] During pre-tightening, the inner shaft 201 moves downward to dock with the driving gear 402, and then the tightening gun 2 drives the inner shaft 201 to rotate, and the torque of the inner shaft 201 is transmitted to the sleeve gear 403 through the driving gear 402 and the transition gear 404, and the sleeve end of the sleeve gear 403 drives the nut to be pre-tightened to the set torque.

[0066] During the initial tightening, the second telescopic component 601 of the swing mechanism 6 drives the rotating shaft 603 to rotate through the rocker rod 602, and the rotating shaft 603 drives the outer shaft 3 to swing around the rotating shaft 603 through the base plate 101, thereby driving the offset head 4 to rotate around the axis of the nut to be tightened, and tightening the nut to the specified torque by combining torque and angle, ensuring that the tightening torque of the equipment meets the tightening torque accuracy requirements.

[0067] When loosening, first the ratchet assembly 405 is reversed to ensure that the offset head 4 and the sleeve gear 403 inside it can rotate in the opposite direction, then the tightening gun 2 drives the inner shaft 201 to rotate in the opposite direction, and the swing mechanism 6 drives the outer shaft 3 to swing in the opposite direction until the nut is loosened to the specified torque.

[0068] When tightening again, the ratchet assembly 405 changes direction again to ensure that the offset head 4 and the sleeve gear 403 inside it can rotate forward, and then the tightening gun 2 drives the inner shaft 201 to rotate forward, and the swing mechanism 6 drives the outer shaft 3 to swing forward until the nut is finally tightened to the required torque.

[0069] The tightening installation of a nut is completed through pre-tightening, initial tightening, loosening and then tightening, and then the remaining nuts are tightened in sequence according to the process requirements through the rotating mechanism, translation mechanism and lifting mechanism.

[0070] Before the offset head 4 enters the blind cavity of the engine, the offset head 4 and the outer shaft 3 are parallel to each other; the lifting mechanism drives the lifting plate 10 to move downward, and the frame 1 moves downward accordingly, so that the offset head 4 at the end of the outer shaft 3 enters the blind cavity.

[0071] After the offset head 4 enters the blind cavity, the first telescopic assembly 551 drives the movable sleeve 503 to move downward through the driving plate 552 and the pull rod 504, and the connecting rod 502 drives the offset head 4 to flip to a horizontal state. At this time, the offset head 4 and the outer shaft 3 are perpendicular to each other.

[0072] After the offset head 4 is in a horizontal state, the support plate 103 is driven downward by the electric cylinder until the end of the inner shaft 201 is mated with the inner angle groove of the shaft end of the driving gear 402. At this time, the tightening gun 2 can transmit the torque to the driving gear 402 through the inner shaft 201, and then the driving gear 402 drives the sleeve gear 403 to rotate.

[0073] Among them, the lifting mechanism can drive the frame 1 to move up and down through the lifting plate 10 and the bracket 604, the translation mechanism can drive the sliding plate 9 to move in the horizontal direction, and the rotating mechanism can drive the rotating plate 8 to rotate around the axis of the first gear 12. The first gear 12 is coaxial with the blind cavity of the engine, and the lifting plate 10, the sliding plate 9 and the rotating plate 8 are connected in sequence, so that the rotation, translation and lifting of the outer shaft 3 can be realized, and the offset head 4 is connected to the outer shaft 3, that is, the offset head 4 can be driven by the outer shaft 3 to align with different nuts in the blind cavity in sequence, and tighten them in sequence.

[0074] To sum up, the present invention proposes a blind cavity nut tightening and loosening device and method, which uses a swing tightening method and a tightening control strategy that combines torque and angle methods, which greatly eliminates most sources of errors, improves the tightening accuracy of the nut and the consistency and stability of the tightening torque of different nuts; it has great promotion value for occasions with narrow space, complex tightening process and high torque accuracy requirements.

[0075] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, 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 limiting the present invention. In addition, the terms "first", "second", and the like are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first", "second", and the like may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0076] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood by specific circumstances.

[0077] The above is based on the ideal embodiment of the present invention. Through the above description, relevant personnel can make various changes and modifications without departing from the technical concept of the present invention. The technical scope of the present invention is not limited to the content in the specification, and the technical scope must be determined according to the scope of the claims.

Claims

1. A blind cavity nut tightening and loosening device, characterized in that: It comprises a frame (1) and a support plate (103) capable of rising and falling relative to the frame (1); an outer shaft (3) is installed at the bottom of the frame (1); an offset head (4) capable of flipping relative to the outer shaft (3) is arranged at the end of the outer shaft (3); and a swing mechanism (6) for driving the outer shaft (3) to swing horizontally is arranged on one side of the frame (1); The offset head (4) comprises a box body (401) connected to the outer shaft (3), a sleeve gear (403) and a driving gear (402) for driving the sleeve gear (403) to rotate are installed inside the box body (401), and one end of the driving gear (402) and the sleeve gear (403) both extend to the outside of the box body (401); A tightening gun (2) is mounted on the support plate (103); an output end of the tightening gun (2) is connected to an inner shaft (201) for driving the driving gear (402) to rotate, and the inner shaft (201) is movably inserted into the outer shaft (3).

2. The blind cavity nut tightening and loosening device according to claim 1, characterized in that: A lifting plate (10), a sliding plate (9), a rotating plate (8) and a fixed plate (7) are sequentially arranged below the frame (1); The fixed plate (7) is provided with a rotating mechanism for driving the rotating plate (8) to rotate, the rotating plate (8) is provided with a translation mechanism for driving the sliding plate (9) to move in a horizontal direction, and the sliding plate (9) is provided with a lifting mechanism for driving the lifting plate (10) to move in an axial direction of the outer shaft (3); The frame (1) is mounted on the lifting plate (10), and the outer shaft (3) passes through the lifting plate (10), the sliding plate (9), the rotating plate (8), and the fixed plate (7) in sequence.

3. The blind cavity nut tightening and loosening device according to claim 2, characterized in that: The frame (1) comprises a bottom plate (101) connected to the swing mechanism (6), a gantry (102) is fixedly mounted on the bottom plate (101), and the support plate (103) is located on the inner side of the gantry (102).

4. The blind cavity nut tightening and loosening device according to claim 3, characterized in that: The swing mechanism (6) comprises a second telescopic component (601), a swing rod (602), a rotating shaft (603) and a bracket (604); the bracket (604) is fixedly mounted on the lifting plate (10); one end of the rotating shaft (603) is rotatably connected to the bracket (604), and the other end is fixedly connected to the bottom plate (101); The second telescopic assembly (601) is connected to the lifting plate (10), the swing rod (602) is perpendicular to the rotating shaft (603), and one end of the swing rod (602) is rotatably connected to the output end of the second telescopic assembly (601), and the other end is fixedly connected to the rotating shaft (603).

5. The blind cavity nut tightening and loosening device according to claim 1, characterized in that: The box body (401) is provided with a ratchet assembly (405) for limiting the one-way rotation of the sleeve gear (403), the ratchet assembly (405) comprising a ratchet and a shifting rod for reversing, the ratchet is connected to the sleeve gear (403), and one end of the shifting rod is connected to the reversing assembly.

6. The blind cavity nut tightening and loosening device according to claim 5, characterized in that: The reversing assembly comprises a winding discharge motor (21) and a spring (22) arranged on two sides of the frame (1) relative to each other, the output end of the winding discharge motor (21) being connected to a winding roller (23), a first soft rope being wound around the winding roller (23), and an end of the first soft rope being connected to the left side of the shifting rod; one end of the spring (22) being connected to the frame (1), and the other end being connected to a second soft rope, and an end of the second soft rope being connected to the right side of the shifting rod.

7. The blind cavity nut tightening and loosening device according to claim 1, characterized in that: The offset head (4) is rotatably connected to the outer shaft (3) via an adapter (501); a movable sleeve (503) is slidably sleeved on the outer shaft (3); a connecting rod (502) is rotatably mounted on the movable sleeve (503); one end of the connecting rod (502) is rotatably connected to the offset head (4); and a driving component (505) for driving the movable sleeve (503) to move axially is provided on the frame (1).

8. The blind cavity nut tightening and loosening device according to claim 7, characterized in that: The driving assembly (505) comprises a driving plate (552) located below the frame (1); a first telescopic assembly (551) for driving the driving plate (552) to move axially along the outer shaft (3) is provided on the frame (1); and the driving plate (552) is fixedly connected to the moving sleeve (503) via a pull rod (504).

9. A method for tightening and loosening a blind cavity nut, using the blind cavity nut tightening and loosening device according to any one of claims 1 to 8, characterized in that: The steps include: S1, the frame (1) moves downward so that the offset head (4) at the end of the outer shaft (3) enters the blind cavity; S2, the offset head (4) enters the blind cavity and flips to a horizontal state, and then the support plate (103) moves downward, so that the end of the inner shaft (201) is mated with the driving gear (402); S3, after the sleeve gear (403) of the offset head (4) is aligned with the nut to be tightened, the tightening gun (2) drives the sleeve gear (403) to rotate through the inner shaft (201) to pre-tighten the nut; S4, after pre-tightening, the swing mechanism (6) drives the outer shaft (3) to swing, so that the offset head (4) rotates around the axis of the nut, thereby tightening the nut; S5. After the nut is tightened, the ratchet assembly (405) changes direction, the tightening gun (2) drives the sleeve gear (403) to rotate in the opposite direction through the inner shaft (201), and the swing mechanism (6) drives the offset head (4) to swing in the opposite direction through the outer shaft (3), thereby loosening the nut; S6, after the nut is loosened to a specified torque, the ratchet assembly (405) is reversed again, driving the offset head (4) to move through the inner shaft (201) and the outer shaft (3), and tightening the nut again; S7. Repeat steps S3 to S6 in sequence to complete the installation of the remaining nuts in the blind cavity.

10. The method for tightening and loosening a blind cavity nut according to claim 9, characterized in that: The process of aligning the sleeve gear (403) of the offset head (4) with the nut to be screwed is achieved through the linkage cooperation between the rotating mechanism, the translation mechanism and the lifting mechanism.

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