An automatic assembly device and precise control method for a multi-section thin-walled cylindrical shell

Abstract

The present invention provides an automatic assembly device for a multi-segment ultra-high-strength steel thin-walled cylindrical shell. The tensioning mechanism is fixedly connected to the tooling shaft, and each tensioning mechanism is connected to an adjusting rod. The tooling shaft rotates under the drive of a rotary servo mechanism. The adjusting rod drives the tensioning flap under the drive of a tightening servo mechanism. The reference flange is fixed at one end of the tooling shaft, and the pushing flange is installed at the other end of the tooling shaft and can move axially. The shell is installed between the pushing flange and the reference flange. The elastic mechanism is restricted between the adjusting nut and the pushing flange. The nut clamping mechanism clamps the adjusting nut under the external drive, and the adjusting nut is threadedly connected to the tooling shaft. The butt joint gap measuring mechanism unit is arranged axially along the tooling shaft at each weld position of the shell, or moves to each weld position of the shell. The weldment length measuring mechanism unit measures the change amount of the position of the shell end face. The present invention can realize the automatic pre-welding assembly and precise control of thin-walled structure shells with different diameters.

Description

Technical Field

[0001] The present invention belongs to the technical field of automation equipment, and particularly relates to an automatic assembly device and a precise control method for the pre-welding of a multi-segment ultra-high-strength steel thin-walled cylindrical shell of a solid rocket motor. Background Art

[0002] As one of the key components providing power for a solid rocket motor, the combustion chamber shell uses ultra-high-strength steels such as T250 and D406A for the shell material to meet the requirements of high-strength performance indicators. It is designed as a multi-segment thin-walled cylindrical structure and then formed by vacuum electron beam welding. This welding process method requires high assembly precision requirements such as butt misalignment and gap before welding of the shell and high assembly consistency. Currently, the commonly used assembly method mainly uses the inner support positioning assembly method of the combustion chamber shell welding tooling fixture. The operator manually assists in adjusting the butt misalignment and gap before welding of the combustion chamber shell, and manually inspects the pre-welding assembly quality after assembly. Due to the process requirements such as the material characteristics and structural design of the shell, it is very difficult for the operator to precisely control the adjustment during the assembly process to ensure that the technical accuracy and assembly consistency requirements of the butt misalignment gap are met. During the existing manual assembly process, if the assembly force is small, it will result in the butt misalignment gap not meeting the technical accuracy requirements during the adjustment, affecting the forming quality of the shell weld; if the assembly force is large, it will cause damage to the shell material, and after vacuum electron beam welding forming, weld crack defects will occur, resulting in the failure of the shell structure. In addition, due to the heavy weight of the shell and the tooling, it is not easy for a single person to perform manual assembly, and means such as a crane must be used, resulting in low assembly efficiency.

[0003] The invention patent application "An integral tensioning tooling for multi-segment thin-walled shells" with the application number CN202111238331.5 discloses an assembly method for a thin-walled shell using butt joint flap inner support positioning, but it can only be assembled manually and does not involve how to achieve automatic precise control of flap inner support positioning.

[0004] The utility model patent application "A thin-walled butt joint circumferential seam vacuum electron beam welding tooling" with the application number CN201320619667.0 requires the operator to manually lift the heavy welding shell and the tooling fixture, repeatedly adjust the positioning, and the artificial inspection error affects the result, which not only increases the labor intensity, but also greatly restricts the pre-welding assembly efficiency, and it is not easy to ensure the consistency of the assembly quality.

[0005] The invention patent application "A coordinated positioning device for automatic butt joint assembly of large thin-walled cylindrical components" with the publication number CN104759876A realizes coordinated positioning through an external adjustment method of the track type. However, the external adjustment device is too large in volume. If it is adjusted inside the furnace cavity of the vacuum electron beam welding furnace, it not only occupies the effective furnace cavity volume but also occupies the effective welding time.

[0006] The invention patent application "Six-Degree-of-Freedom Positioning and Posture Adjustment Equipment for Automatic Assembly of Large-Scale Cylindrical Thin-Walled Components" with the publication number CN104229158A uses a six-degree-of-freedom external adjustment positioning method to achieve coordinated positioning. There is also a problem that the volume of the external adjustment device is too large, which not only occupies the effective furnace cavity volume but also occupies the effective welding time. Summary of the Invention

[0007] In order to overcome the deficiencies of the prior art, the present invention provides an automatic assembly device for multi-segment ultra-high-strength steel thin-walled cylindrical shells, which can realize the automatic pre-welding assembly and precise control of thin-walled structure shells with different diameter sizes, solve the problem of poor consistency in pre-welding assembly quality, thereby eliminating potential quality hazards in welds, and achieving the purpose of improving the assembly and inspection efficiency and reducing the labor intensity of operators.

[0008] The technical solution adopted by the present invention to solve its technical problems is: an automatic assembly device for multi-segment ultra-high-strength steel thin-walled cylindrical shells, including a pipe seam adjustment mechanism, a weldment length measurement mechanism, a butt joint gap measurement mechanism, and a welding positioning tooling fixture.

[0009] The described pipe seam adjustment mechanism includes an automatic tensioning adjustment mechanism unit and a pipe seam gap automatic adjustment mechanism unit;

[0010] The automatic tensioning adjustment mechanism unit includes a rotary servo mechanism, a tooling shaft, a tightening servo mechanism, a plurality of adjustment rods, and a plurality of tensioning mechanisms; the tensioning mechanisms are coaxially fixed on the tooling shaft, corresponding to each section of the shell in position. Each tensioning mechanism is respectively connected to an adjustment rod, and can drive the tensioning petals by the adjustment rod to tension the shell; the tooling shaft rotates under the drive of the rotary servo mechanism; the adjustment rods rotate under the drive of the tightening servo mechanism;

[0011] The pipe seam gap automatic adjustment mechanism unit includes a nut clamping mechanism, an adjusting nut, an elastic mechanism, a pushing flange, and a reference flange; the reference flange is axially fixed at one end of the tooling shaft, the pushing flange is coaxially installed at the other end of the tooling shaft and can move axially along the tooling shaft. The shell is installed between the pushing flange and the reference flange; the elastic mechanism is restricted between the adjusting nut and the pushing flange; the nut clamping mechanism can be clamped or loosened by an external drive to clamp or loosen the adjusting nut; the adjusting nut is threadedly connected to the tooling shaft;

[0012] The butt joint gap measurement mechanism unit is arranged axially along the tooling shaft at each weld position of the shell, or moves axially along the tooling shaft to each weld position of the shell under the action of a linear drive mechanism;

[0013] The weldment length measurement mechanism unit measures the change amount of the position of the end face of the shell near the pushing flange.

[0014] The described tightening servo mechanism is provided with an output shaft capable of moving along a guide rail parallel to the tooling axis; one end of the adjusting rod is connected to each tensioning mechanism through a rack and pinion mechanism, and the other end is close to the tightening servo mechanism and distributed within the same circumference; when the tooling axis rotates driven by the rotary servo mechanism, the end faces of the adjusting rods move along the circumference; the output shaft of the tightening servo mechanism moves along the guide rail into the circumference, connects with a certain adjusting rod and drives the adjusting rod.

[0015] The described tensioning mechanism adopts a mechanical chuck or a hydraulic chuck.

[0016] The nut clamping mechanism is driven by a cylinder or a motor.

[0017] The described elastic mechanism adopts a spring or an elastic telescopic material.

[0018] The described docking gap measurement mechanism unit adopts a 3D camera, an infrared camera, a contact displacement sensor or a laser displacement sensor.

[0019] The described weldment length measurement mechanism unit adopts a contact displacement sensor or a laser displacement sensor.

[0020] The described linear drive mechanism adopts a guide rail driven by a cylinder or a lead screw mechanism driven by a motor.

[0021] The present invention also provides an accurate control method for the above device, including the following steps:

[0022] 1) Load the thin-walled shell to be welded into the welding positioning tooling fixture;

[0023] 2) Preset the reference values of the pre-welding technical index requirements, including the rotation angle of the rotary servo and the rotation angle of the tightening servo;

[0024] 3) Start the automatic tensioning adjustment mechanism. The rotary servo mechanism drives the tooling axis to drive the adjusting rod to rotate. After the tightening servo mechanism is connected to the adjusting rod, it rotates according to the preset angle value. The adjusting rod drives the tensioning mechanism to tension the shell; then the tightening servo mechanism disengages from the adjusting rod, and the tightening servo mechanism and the rotary servo drive the tooling axis to return to zero position, and the adjustment of the misalignment height difference of the gap is completed; start the pipe gap automatic adjustment mechanism, the nut clamping mechanism clamps the adjusting nut, the rotary servo mechanism drives the tooling axis to rotate a preset angle, the adjusting nut squeezes the elastic mechanism, and the gap width between the shells is compressed; after completion, the nut clamping mechanism disengages from the adjusting nut, and the rotary servo mechanism returns to zero, and the adjustment of the gap width is completed;

[0025] 4) The rotary servo mechanism drives the tooling axis to rotate one circle, and the docking gap measurement mechanism continuously feeds back the measured values of the gap and misalignment height difference of the thin-walled shell to be welded, and compares them with the set reference values;

[0026] 5) The welding part length measurement mechanism real - time feeds back the total length measurement value of the thin - walled shell to be welded, and compares it with the reference value;

[0027] 6) According to the comparison value of the measured value of the height difference of the gap misalignment of the thin - walled shell, calculate the angle that needs to be adjusted based on the change amount of the height difference value of the gap for each fixed - value rotation angle of the tightening servo mechanism, and start the automatic tensioning adjustment mechanism; Similarly, according to the comparison value of the gap width of the thin - walled shell, calculate the angle that needs to be adjusted based on the change amount of the width value of the pipe seam gap for each fixed - value rotation angle of the rotation servo mechanism, and start the gap automatic adjustment mechanism; Similarly, the fine - tuning of the difference in the length - direction comparison is adjusted to be consistent with the adjustment of the gap width measurement value; until each actual assembly measurement value is within the reference value error range required by the technical indicators;

[0028] 7) The control system automatically records the final assembly value that meets the technical indicator requirements and saves it to the database;

[0029] 8) Synchronously transfer the assembled thin - walled shell and the welding positioning tooling fixture to the welding station to complete this assembly and inspection process.

[0030] The beneficial effects of the present invention are as follows:

[0031] (1) Through the automatic assembly method of multi - section thin - walled cylindrical shells, the manual experience is transformed into precise process control;

[0032] a) Through the automatic tensioning adjustment mechanism unit, realize the automated precise adjustment of the controllable inner support positioning of the expanding petals, and solve the problem that the original manual tensioning assembly method depends on manual experience and technical proficiency and cannot achieve the positioning accuracy of the expanding petals;

[0033] b) Through the pipe seam gap automatic adjustment mechanism unit, realize the online automatic adjustment of the controllable pipe seam gap of multi - section thin - walled shells, and solve the problem that the original manual tightening of nuts cannot quantify the tightening accuracy;

[0034] c) Through the on - line automatic measurement device, feed back the values of the inner support positioning of the expanding petals and the pipe seam gap of multi - section thin - walled shells to the control system. The control system compares the feedback values with the technical indicator values, and then converts the difference between the two into a transmission ratio parameter and transmits it to the automatic tensioning adjustment mechanism unit and the pipe seam gap automatic adjustment mechanism unit for adjustment respectively until the error value is within a reasonable range; avoid measurement errors caused by humans, improve the assembly inspection accuracy and the consistency of the pre - welding assembly quality of the shell, and effectively reduce the quality problems caused by the dimensional measurement errors of humans.

[0035] (2) Form standardized process flows with different parameters, and improve the assembly qualification rate and quality consistency of various thin - walled cylindrical shells;

[0036] The original manual assembly relied on the personal experience of the operators, making it prone to quality problems:

[0037] a) Due to different personnel, the assembly quality of the same type of housing is inconsistent, which is likely to cause potential product quality hazards;

[0038] b) Due to inconsistent operators and different ways of using tooling fixtures, it is easy to cause damage to the tooling fixtures;

[0039] c) Different manual assembly techniques are likely to result in unqualified assembly or even quality problems such as damage to the housing;

[0040] d) When switching production of products, due to different materials and assembly dimensions of different types of products, it is easy to have assembly quality problems with the products;

[0041] The automatic assembly device and precise control method realized by the present invention quantitatively analyze and control the original uncontrollable factors of manual operation, reduce the damage to tooling fixtures and housing products, and improve the assembly qualification rate and consistency; at the same time, for the materials and external dimensions of different thin-walled cylindrical housings, through on-line adjustment and control, different standardized process flows can be formed, which are applicable to different types of housing products, and the invention is applied to specific process practices to replace manual assembly and solve the pre-welding assembly quality problems.

[0042] (3) Achieve miniaturized and automated assembly to improve assembly efficiency;

[0043] The present invention is compactly designed. The automatic tensioning adjustment mechanism unit, the pipe gap automatic adjustment mechanism unit, and the on-line automatic measurement device share a set of rotary servo mechanisms. The structure size is close to that of the existing thin-walled cylindrical housing, and it can realize internal adjustment of the housing. Compared with the external adjustment device, the volume and weight are greatly reduced; at the same time, it replaces manual work, simplifies the cumbersome manual assembly and inspection procedures, greatly reduces the labor intensity of operators and inspectors, avoids operation time errors caused by different manual proficiency levels, and improves the assembly and inspection efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 is a schematic structural diagram of the present invention;

[0045] Figure 2 is a schematic structural diagram of the tensioning adjustment mechanism unit;

[0046] Figure 3 is a schematic structural diagram of the pipe gap adjustment mechanism unit;

[0047] Figure 4 is a schematic structural diagram of the on-line measurement mechanism;

[0048] Figure 5 is a schematic structural diagram of a combustion chamber housing of a certain engine;

[0049] Figure 6 It is the overall diagram of the application example;

[0050] In the figure, 1 - pipe seam adjustment mechanism, 2 - weldment length measurement mechanism, 3 - butt joint gap measurement mechanism, 4 - welding positioning tooling fixture, 5 - control system, 6 - electrical cabinet, 7 - assembly and adjustment frame (platform), 8 - thin-walled shell, 9 - rotary servo mechanism, 10 - tooling shaft, 11 - tightening servo mechanism, 12 - adjustment rod (left), 13 - adjustment rod (right), 14 - tensioning mechanism (left), 15 - tensioning mechanism (right), 16 - nut clamping mechanism, 17 - adjusting nut, 18 - elastic mechanism, 19 - pushing flange, 20 - reference flange, 21 - butt joint gap measurement mechanism unit, 22 - weldment length measurement mechanism unit, 23 - workbench surface, 24 - linear drive mechanism, 25 - front connecting piece, 26 - cylinder body, 27 - rear connecting piece, 28 - combustion chamber shell of a certain engine, 29 - the present invention. Specific embodiments

[0051] The present invention will be further described below in conjunction with the accompanying drawings and embodiments. The present invention includes but is not limited to the following embodiments.

[0052] The present invention provides an automatic assembly device for multi-segment ultra-high-strength steel thin-walled cylindrical shells, mainly including a pipe seam adjustment mechanism, a weldment length measurement mechanism, a butt joint gap measurement mechanism, a welding positioning tooling fixture, a control system, an electrical cabinet, and an assembly and adjustment frame (platform).

[0053] The present invention includes a pipe seam adjustment mechanism, a weldment length measurement mechanism, a butt joint gap measurement mechanism, and a welding positioning tooling fixture.

[0054] The described pipe seam adjustment mechanism includes an automatic tensioning adjustment mechanism unit and a pipe seam gap automatic adjustment mechanism unit;

[0055] The automatic tensioning adjustment mechanism unit includes a rotary servo mechanism, a tooling shaft, a tightening servo mechanism, a plurality of adjustment rods, and a plurality of tensioning mechanisms; the tensioning mechanisms are coaxially and fixedly connected to the tooling shaft, corresponding to each section of the shell in position, each tensioning mechanism is respectively connected to an adjustment rod, and can drive the tensioning petals by the adjustment rod to tension the shell; the tooling shaft rotates under the drive of the rotary servo mechanism; the adjustment rod rotates under the drive of the tightening servo mechanism;

[0056] The described pipe gap automatic adjustment mechanism unit includes a nut clamping mechanism, an adjusting nut, an elastic mechanism, a pushing flange, a reference flange, and a rotary servo mechanism shared with the automatic tensioning adjustment mechanism; the axial position of the reference flange is fixed at one end of the tooling shaft, the pushing flange is coaxially installed at the other end of the tooling shaft and can move axially along the tooling shaft, and the shell is installed between the pushing flange and the reference flange; the elastic mechanism is restricted between the adjusting nut and the pushing flange; the nut wrench mechanism can clamp or loosen the adjusting nut under the drive of an external cylinder; the tooling shaft and the pushing flange and reference flange on the tooling rotate under the drive of the rotary servo mechanism, and can rotate forward or backward; since the adjusting nut is installed on the thread of the tooling shaft, when the nut is in a clamped state and the tooling shaft rotates but the axial position of the tooling shaft does not move, it is equivalent to jamming the nut so that it cannot rotate and can only move axially, squeezing or releasing the elastic mechanism. The elastic mechanism axially squeezes the distance between the pushing flange and the reference flange, and reverse rotation releases the squeezing length of the elastic mechanism, increasing the distance between the pushing flange and the reference flange. The width of the gap and the value of the total length of the thin-walled shell are adjusted by the pipe gap automatic adjustment mechanism unit.

[0057] The described butt joint gap measuring mechanism unit is arranged axially along the tooling shaft at each weld position of the shell, or can move axially along the tooling shaft to each weld position of the shell under the action of a linear drive mechanism; the butt joint gap measuring mechanism unit can measure the misalignment height difference and gap width value of the gap.

[0058] The described tightening servo mechanism can move linearly parallel to the tooling shaft under the drive of an external cylinder or motor; one end of the adjusting rod is connected to the tensioning mechanism through a gear-rack mechanism, and the other end is circumferentially distributed on the same side of the tooling shaft; when the tooling shaft rotates under the drive of the rotary servo mechanism, each adjusting rod can move to the output shaft position of the tightening servo mechanism at different angles respectively; the tightening servo mechanism moves forward and connects with the adjusting rod. The connecting mechanism here can be an internal hexagonal socket type insertion or a pneumatic claw clamping connection, and vice versa, it loosens the connection and moves backward; the tightening servo mechanism drives the connected adjusting rod to rotate, and the adjusting rod drives the tensioning mechanism to adjust through the gear-rack mechanism. The height difference of the gap of the thin-walled shell is adjusted by the automatic tensioning adjustment mechanism.

[0059] The described weldment length measuring mechanism unit is fixed on the workbench surface and can measure the change amount of the position of the side reference surface of the thin-walled shell on the side where the pushing flange is located. The detection in the length direction is supplementary measurement data for the gap width value.

[0060] The described tensioning mechanism adopts a mechanical chuck or a hydraulic chuck.

[0061] The described nut clamping mechanism is driven by a cylinder or a motor.

[0062] The elastic mechanism described above uses a spring or an elastic telescopic material.

[0063] The butt joint gap measurement mechanism unit described above directly measures using a 3D camera, an infrared camera, a contact displacement sensor, or a laser displacement sensor.

[0064] The weldment length measurement mechanism unit described above uses a contact displacement sensor or a laser displacement sensor.

[0065] The linear drive mechanism described above can be a guide rail driven by a cylinder or a lead screw mechanism driven by a motor.

[0066] The present invention also provides an accurate control method for the above device, including the following steps:

[0067] 1) Load the thin-walled shell to be welded into the welding positioning tooling fixture, and place the whole on the bracket of the workbench surface. Connect the rotary servo mechanism and the tooling shaft through the coupling of the transmission mechanism. The transmission mechanism can be a synchronous belt or a sprocket chain mechanism. At the same time, all mechanisms return to the initial position and zero.

[0068] 2) Open the operation panel of the control system, and preset the reference values required by the pre-welding technical indicators, including the rotation angle of the rotary servo and the rotation angle of the tightening servo. For example, rotate 720 degrees forward or 360 degrees backward, etc. The adjustment sequence and adjustment positions of the rotary servo mechanism and the tightening servo mechanism have been pre-set in the program. At the same time, the reference change values of the thin-walled shell adjusted by the pipe joint gap automatic adjustment mechanism and the automatic tensioning adjustment mechanism have been obtained through process experiments in advance (the change amount of the width value of the pipe joint gap when the rotary servo rotates a fixed value angle, the change amount of the position and intersection angle of the adjusting rod when the rotary servo rotates a fixed value angle, the change amount of the height difference value of the gap when the tightening servo rotates a fixed value angle, the change amount of the height difference value of the length when the rotary servo rotates a fixed value).

[0069] 3) Start the automatic operation button. The control system preferentially starts the automatic tensioning adjustment mechanism. The rotary servo mechanism drives the tooling shaft to drive the adjusting rod to rotate. The tightening servo mechanism moves forward to connect with the adjusting rod. The tightening servo rotates according to the preset angle value. The adjusting rod drives the tensioning mechanism to tension the thin-walled shell through the gear-rack mechanism. After completion, the tightening servo mechanism moves backward to disengage from the adjusting rod. The tightening servo mechanism and the rotary servo drive the position of the tooling shaft to zero, and the adjustment of the misalignment height difference of the gap is completed. The control system starts the pipe joint gap automatic adjustment mechanism. The nut clamping mechanism can clamp the adjusting nut under the drive of an external cylinder. The rotary servo mechanism drives the tooling shaft to rotate a preset angle. The adjusting nut squeezes the elastic mechanism to achieve compression, and the corresponding gap width between the thin-walled shells is compressed. After completion, the nut clamping mechanism withdraws from the position where it clamps the adjusting nut, and the rotary servo mechanism returns to zero, and the adjustment of the gap width is completed;

[0070] 4) The rotary servo mechanism drives the tooling shaft to rotate one circle. The butt joint seam measuring mechanism real-time feeds back the measured values of the seam width and the misalignment height difference of the thin-walled shell to be welded, and compares them with the set technical requirement values.

[0071] 5) The weldment length measuring mechanism real-time feeds back the measured value of the total length of the thin-walled shell to be welded, and compares it with the set technical requirement values.

[0072] 6) The control system calculates the angle to be adjusted according to the measured value comparison of the misalignment height difference of the thin-walled shell's seam, based on the width change reference value (the change amount of the height difference value of the seam for each fixed-angle rotation of the tightening servo), and starts the automatic tensioning adjustment mechanism, finally driving the tightening servo device to fine-tune and then measure. Similarly, the control system calculates the angle to be adjusted according to the measured value comparison of the seam width of the thin-walled shell, based on the misalignment height difference change reference value (the change amount of the width value of the pipe seam for each fixed-angle rotation of the rotary servo), and starts the gap automatic adjustment mechanism, finally driving the rotary servo device to fine-tune and then measure. Similarly, the control system fine-tunes the difference comparison in the length direction to be consistent with the adjustment of the seam width measurement value. If the above parameters are within the set technical requirement values, the corresponding adjustment mechanism is not started. Finally, the actual assembly measurement value is within the reference value error range required by the technical indicators.

[0073] 7) The control system automatically records the final assembly measurement values that meet the technical indicator requirements and saves them to the database.

[0074] 8) Remove the assembled thin-walled shell and the welding positioning tooling fixture to complete this assembly and inspection process.

[0075] The innovation points of the present invention are mainly reflected in:

[0076] (1) Through the pipe seam adjustment mechanism composed of the automatic tensioning adjustment mechanism unit and the pipe seam gap automatic adjustment mechanism unit, the control system converts the initial process parameters into the motion parameters of the pipe seam adjustment mechanism, realizing the precise adjustment of the assembly misalignment and gap size of the butt joint seam before welding of the thin-walled cylindrical shell.

[0077] The automatic tensioning and adjusting mechanism unit includes a rotary servo mechanism, a tooling shaft, a tightening servo mechanism, an adjusting rod (left), an adjusting rod (right), a tensioning mechanism (left), and a tensioning mechanism (right). The rotary servo mechanism drives the tooling shaft to rotate according to the initial process parameters input by the control system, rotates the adjusting rod (left) of the tensioning mechanism (left) on the tooling shaft to the corresponding position of the tightening servo mechanism, the tightening servo mechanism docks with the adjusting rod (left), and drives the tensioning mechanism (left) to tighten the left side wall of the thin-walled shell. Then, the rotary servo mechanism drives the tooling shaft to rotate, rotates the adjusting rod (right) of the tensioning mechanism (right) on the tooling shaft to the corresponding position of the tightening servo mechanism, the tightening servo mechanism docks with the adjusting rod (right), and drives the tensioning mechanism (right) to tighten the right side wall of the thin-walled shell. For multi-section thin-walled shells, multiple tensioning mechanisms, adjusting rods, and tightening servo mechanisms can be set. The tensioning mechanism is not limited to a pneumatic chuck or a hydraulic chuck.

[0078] The automatic pipe seam gap adjusting mechanism unit includes a rotary servo mechanism, a tooling shaft, a nut clamping mechanism, an adjusting nut, an elastic mechanism, a pushing flange, and a reference flange. The nut clamping mechanism clamps and holds the adjusting nut. The rotary servo mechanism drives the tooling shaft to rotate according to the initial process parameters input by the control system, and the elastic mechanism pushes the pushing flange towards the position of the reference flange, squeezing the gap between the multi-section thin-walled shells until the requirement is met. The nut clamping mechanism can be driven by a cylinder or a motor, and the elastic mechanism can be a spring or an elastic telescopic material, etc.

[0079] (2) An on-line automatic measuring device is adopted to dynamically monitor along the butt joints distributed on the shell during the 360° rotary motion of the thin-walled cylindrical shell, and collect and process the real-time data.

[0080] This mechanism includes: a butt joint gap measuring mechanism unit, a weldment length measuring mechanism unit, a workbench surface, a linear drive mechanism, and a rotary servo mechanism, a tooling shaft, a tensioning mechanism (left), and a tensioning mechanism (right) shared with the pipe seam adjusting mechanism.

[0081] The linear drive mechanism adjusts the butt joint gap measuring mechanism unit to the pipe joint position tightened by the tightening mechanism (left), and the weldment length measuring mechanism unit runs to the side reference position of the thin-walled shell; then, the rotary servo mechanism drives the tooling shaft to rotate according to the initial process parameters input by the control system. At the same time, the butt joint gap measuring mechanism unit measures the pipe joint size in real time and feeds it back to the control system, and the weldment length measuring mechanism unit measures the overall length size of the thin-walled shell in real time and feeds it back to the control system. After the full-circle measurement is completed, the linear drive mechanism adjusts the butt joint gap measuring mechanism unit to the pipe joint position tightened by the tightening mechanism (right), and the weldment length measuring mechanism unit runs to the side reference position of the thin-walled shell; then, the rotary servo mechanism drives the tooling shaft to rotate according to the initial process parameters input by the control system. At the same time, the butt joint gap measuring mechanism unit measures the pipe joint size in real time and feeds it back to the control system, and the weldment length measuring mechanism unit measures the overall length size of the thin-walled shell in real time and feeds it back to the control system. The butt joint gap measuring mechanism unit can directly measure with a 3D camera, an infrared camera, a contact displacement sensor, a laser displacement sensor, or measure through a torque sensor, an angle sensor, etc.; the weldment length measuring mechanism unit can be a contact displacement sensor, a laser displacement sensor, etc.; the linear drive mechanism can be driven by a cylinder or a servo motor, etc.; for multiple-segment thin-walled shells, multiple tightening mechanisms, butt joint gap measuring mechanism units, and weldment length measuring mechanism units can be set up.

[0082] Working principle: The control system drives the pipe joint adjustment mechanism to precisely adjust the welding positioning tooling fixture. Through the measurement data feedback of the weldment length measuring mechanism and the butt joint measuring mechanism, the optimal adjustment is realized, so that the assembly dimensions of the thin-walled shell meet the pre-welding technical index requirements. The electrical cabinet and the assembly and adjustment rack (platform) belong to the basic support auxiliary function units.

[0083] During the pre-welding automatic assembly adjustment, first place the pre-assembled thin-walled shell and the welding positioning tooling fixture on the assembly and adjustment rack (platform). Turn on the switch of the electrical cabinet. After the system starts, input the initial process parameters through the control system and start the operation. The pipe joint adjustment mechanism executes the command and drives the welding positioning tooling fixture to make the pre-welding assembly dimensions of the thin-walled shell approach the reference value; the control system continues to issue commands to drive the weldment length measuring mechanism and the butt joint gap measuring mechanism to measure the pre-welding assembly dimensions of the thin-walled shell, and feed the measurement data back to the control system. Compare and judge with the reference value and automatically adjust the process parameters until the error range requirement is met, and save the final data. Then this assembly process is completed, and the adjusted thin-walled shell and the welding positioning tooling fixture are taken out together and transferred to the welding process. The specific process is as follows:

[0084] 1) Load the thin-walled shell to be welded into the welding positioning tooling fixture and perform pre-fixing;

[0085] 2) Open the control system operation panel and preset the reference values required by the pre-welding technical specifications;

[0086] 3) Start the automatic operation button, and the pipe joint adjustment mechanism automatically adjusts the gap, height difference, and total length of the thin-walled shell to be welded;

[0087] 4) The butt joint measurement mechanism real-time feeds back the measured values of the gap and height difference of the thin-walled shell to be welded, and compares them with the reference values;

[0088] 5) The weldment length measurement mechanism real-time feeds back the measured value of the total length of the thin-walled shell to be welded, and compares it with the reference value;

[0089] 6) The control system makes real-time optimization adjustments according to the comparison values, so that the actual assembly value is within the reference value error range required by the technical specifications;

[0090] 7) The control system automatically records the final assembly value that meets the technical specification requirements and saves it to the database;

[0091] 8) Synchronously transfer the assembled thin-walled shell and the welding positioning tooling fixture to the welding station to complete the current assembly and inspection process.

[0092] Taking the combustion chamber shell of a certain engine as an example, the pre-welding automatic assembly inspection and verification are carried out. Figure 5 It is a schematic diagram of the structure of the combustion chamber shell of a certain engine. The shell material is thin-walled T250 ultra-high-strength steel with a wall thickness of 1.5 mm. The front connector, cylinder body, and rear connector are assembled and welded by vacuum electron beam welding method. The pre-welding misalignment is not more than 0.15 mm, the butt joint gap is not more than 0.05 mm, and the quality of the circumferential weld of the shell after welding meets the requirements of Grade I standard in QJ972-86 "General Technical Conditions for Fusion Welding of Ultra-High-Strength Steel".

[0093] The pre-welding automatic assembly process of the combustion chamber shell of a certain engine is as follows;

[0094] 1) Install the parts to be welded into the welding tooling fixture and pre-fix them on the assembly and adjustment platform;

[0095] 2) Open the control system operation panel and preset the reference values required by the pre-welding technical specifications (pre-welding misalignment is not more than 0.15 mm, butt joint gap is not more than 0.05 mm);

[0096] 3) Start the automatic operation button, and the pipe joint adjustment mechanism automatically adjusts the gap (not more than 0.05 mm), height difference (pre-welding misalignment is not more than 0.15 mm), and total length of the shell (1317 mm) of the parts to be welded;

[0097] 4) The butt joint seam measurement mechanism real - time feeds back the measured values of the seam and height difference of the thin - walled shell to be welded, and compares them with the reference values: Measure a set of gap values and height difference values on each of the left and right sides. Each set has 8 data. If any one of the gap data is greater than the reference value by 0.05 mm and the height difference is greater than the reference value by 0.15 mm, the system control panel displays "NG", and enters the control system comparison and adjustment step f;

[0098] 5) The weldment length measurement mechanism real - time feeds back the measured value of the total length of the thin - walled shell to be welded, and compares it with the reference value: Select 4 values for length measurement and compare them with the reference value of 1317 mm. If it is greater than 1317 mm, the system control panel displays "NG", and enters the control system comparison and adjustment step f;

[0099] 6) The control system makes real - time optimization adjustments according to the comparison values, so that the actual assembly value is within the reference value error range required by the technical specifications. The system control panel displays "OK", the adjustment step ends, and enters step g;

[0100] 7) The control system automatically records the final assembly value that meets the technical specification requirements and saves it to the database;

[0101] 8) Synchronously transfer the assembled thin - walled shell and the welding positioning tooling fixture to the welding station to complete this assembly and adjustment.

Claims

1. An automatic assembly device for a multi-segment ultra-high-strength steel thin-walled cylindrical shell, comprising a pipe seam adjustment mechanism, a weldment length measurement mechanism, a butt joint gap measurement mechanism, and a welding positioning tooling fixture, characterized in that, The described pipe seam adjustment mechanism includes an automatic tensioning adjustment mechanism unit and a pipe seam clearance automatic adjustment mechanism unit; the automatic tensioning adjustment mechanism unit includes a rotary servo mechanism, a tooling shaft, a tightening servo mechanism, a plurality of adjusting rods and a plurality of tensioning mechanisms; the tensioning mechanisms are coaxially fixed on the tooling shaft, corresponding to each section of the housing, each tensioning mechanism is respectively connected to an adjusting rod, and the tensioning petals can be driven by the adjusting rod to tension the housing; the tooling shaft rotates under the drive of the rotary servo mechanism; the adjusting rod rotates under the drive of the tightening servo mechanism; the pipe seam clearance automatic adjustment mechanism unit includes a nut clamping mechanism, an adjusting nut, an elastic mechanism, a pushing flange and a reference flange; the reference flange is axially fixed at one end of the tooling shaft, the pushing flange is coaxially installed at the other end of the tooling shaft and can move axially along the tooling shaft, and the housing is installed between the pushing flange and the reference flange; the elastic mechanism is restricted between the adjusting nut and the pushing flange; the nut clamping mechanism can clamp or loosen the adjusting nut under the drive of the outside; the adjusting nut is threadedly connected to the tooling shaft; the butt joint gap measuring mechanism unit is arranged axially along the tooling shaft at each weld position of the housing, or moves axially along the tooling shaft to each weld position of the housing under the action of a linear drive mechanism; the weldment length measuring mechanism unit measures the change amount of the end face position of the housing near the pushing flange, and the nut clamping mechanism is driven by a cylinder or a motor; Among them, the precise control method of the device includes the following steps: 1) Load the thin-walled housing to be welded into the welding positioning fixture; 2) Preset the reference values of the pre-welding technical index requirements, including the rotation angle of the rotary servo and the rotation angle of the tightening servo; 3) Start the automatic tensioning adjustment mechanism. The rotary servo mechanism drives the tooling shaft to drive the adjusting rod to rotate. After the tightening servo mechanism is connected to the adjusting rod and rotates according to the preset angle value, the adjusting rod drives the tensioning mechanism to tension the housing; then the tightening servo mechanism disengages from the adjusting rod, and the tightening servo mechanism and the rotary servo drive the tooling shaft to return to zero position, and the adjustment of the misalignment height difference of the gap is completed; start the pipe seam clearance automatic adjustment mechanism, the nut clamping mechanism clamps the adjusting nut, the rotary servo mechanism drives the tooling shaft to rotate by a preset angle, the adjusting nut squeezes the elastic mechanism, and the gap width between the housings is compressed; after completion, the nut clamping mechanism disengages from the adjusting nut, and the rotary servo mechanism returns to zero, and the adjustment of the gap width is completed; 4) The rotary servo mechanism drives the tooling shaft to rotate one circle, and the butt joint gap measuring mechanism feeds back the measured values of the gap and misalignment height difference of the thin-walled housing to be welded in real time, and compares them with the set reference values; 5) The weldment length measuring mechanism feeds back the measured value of the total length of the thin-walled housing to be welded in real time, and compares it with the reference value; 6) Compare the measured values of the gap misalignment height difference of the thin-walled shell, calculate the angle to be adjusted based on the change amount of the height difference value of the gap for each fixed-angle rotation of the tightening servo mechanism, and start the automatic tensioning adjustment mechanism; similarly, based on the comparison value of the gap width of the thin-walled shell, calculate the angle to be adjusted according to the change amount of the width value of the pipe gap for each fixed-angle rotation of the rotation servo mechanism, and start the gap automatic adjustment mechanism; similarly, the fine adjustment of the difference in the length direction comparison is adjusted to be consistent with the adjustment of the gap width measurement value; until each actual assembly measurement value is within the reference value error range required by the technical indicators. 7) The control system automatically records the final assembly value that meets the technical indicator requirements and saves it to the database. 8) Synchronously transfer the assembled thin-walled shell and the welding positioning tooling fixture to the welding station to complete the current assembly and inspection process.

2. The automatic assembly device for a multi-segment ultra-high-strength steel thin-walled cylindrical shell according to claim 1, wherein The tightening servo mechanism is provided with an output shaft capable of moving along a guide rail parallel to the tooling shaft; one end of the adjustment rod is connected to each tensioning mechanism through a gear-rack mechanism, and the other end is close to the tightening servo mechanism and distributed within the same circumference; when the tooling shaft rotates driven by the rotation servo mechanism, the end faces of the adjustment rods move along the circumference; the output shaft of the tightening servo mechanism moves along the guide rail into the circumference, connects to a certain adjustment rod and drives the adjustment rod.

3. The automatic assembly device for a multi-section ultra-high strength steel thin-walled cylindrical shell according to claim 1, wherein, The tensioning mechanism adopts a mechanical chuck or a hydraulic chuck.

4. The automatic assembly device for a multi-segment ultra-high strength steel thin-walled cylindrical shell according to claim 1, characterized in that, The elastic mechanism adopts an elastic telescopic material.

5. The automatic assembly device for a multi-section ultra-high-strength steel thin-walled cylindrical shell according to claim 1, characterized in that, The docking gap measurement mechanism unit adopts a 3D camera, an infrared camera, a contact displacement sensor or a laser displacement sensor.

6. The automatic assembly device for a multi-section ultra-high-strength steel thin-walled cylindrical shell according to claim 1, characterized in that, The weldment length measurement mechanism unit adopts a contact displacement sensor or a laser displacement sensor.

7. The automatic assembly device for a multi-segment ultra-high strength steel thin-walled cylindrical shell according to claim 1, characterized in that, The linear drive mechanism adopts a guide rail driven by a cylinder or a lead screw mechanism driven by a motor.

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