An automatic production line for thin-walled pipe fittings for engines and a production method thereof

Abstract

The application provides an automatic production line for thin-walled pipe fittings for engines and a production method thereof, and the automatic production line comprises a linear truss, a mechanical hand is arranged on the linear truss to walk, a feeding station, a chamfering and fine turning frame station, a guide hole and fine boring hole station, an inner hole detection station, a transfer bin, a fine turning shape station, an outer diameter detection station, a thread and stop opening turning station, an inner diameter detection and laser coding station are sequentially arranged on one side of the linear truss along the conveying direction of the thin-walled pipe fittings, corresponding machine tools are arranged on each station, and the machine tools are vertically placed with the linear truss. The automatic production line realizes the automatic production of the thin-walled pipe fittings, and simultaneously solves the problem that the inner and outer shape surfaces of the thin-walled pipe fittings are prone to deformation.

Description

Technical Field

[0001] This invention relates to the field of thin-walled tube processing technology, and in particular to an automated production line and production method for thin-walled tubes for engines. Background Technology

[0002] The engine, a crucial component providing power to rockets, is a thin-walled tubular part made of 30CrMnSiA material. It is 1m in length, requires high dimensional accuracy, has a small diameter, and a wall thickness of 1.50mm after machining. The machining of the outer shape and the tendency for deformation during internal boring of this thin-walled tubular part are common challenges in the industry. For many years, the company has used a mandrel method for machining the outer and inner shapes of thin-walled tubular parts. Internal boring is performed using specialized boring equipment, with manual removal of the cutting tools to achieve a scratch-free process. However, this method suffers from long machining steps, and the machining of the outer shape and inner hole remains a bottleneck in the entire production process. Furthermore, automating the production of thin-walled tubular parts is an urgent problem to be solved. Summary of the Invention

[0003] This invention proposes an automated production line and production method for thin-walled tubes used in engines, which realizes the automated production of thin-walled tubes and solves the problem of easy deformation of the inner and outer surfaces of thin-walled tubes during processing.

[0004] The technical solution of the present invention is implemented as follows: An automated production line for thin-walled tubes for engines includes a linear truss, on which a traveling robot arm is mounted. Along the conveying direction of the thin-walled tubes, one side of the linear truss is sequentially provided with a feeding station, a chamfering and precision turning station, a guide hole turning and precision boring station, an inner hole inspection station, a transfer hopper, a precision turning station, an outer diameter inspection station, a thread turning and stop station, and an inner diameter inspection and laser marking station. Each station is equipped with a corresponding machine tool, which is placed perpendicular to the linear truss.

[0005] Furthermore, a first machine tool is set up on the chamfering and precision turning station. Both the main spindle and the secondary spindle of the first machine tool are equipped with end face inner support fixtures. Tapered positioning sleeves are set on the outer side of the end face inner support fixtures. The tapered positioning sleeves are equipped with tapered surfaces that cooperate with the end chamfer of the thin-walled tube.

[0006] Furthermore, a third machine tool is set up at the precision turning station. The third machine tool is equipped with a spindle with a spindle inner support fixture and a secondary spindle with a secondary spindle inner support fixture. Both the spindle inner support fixture and the secondary spindle inner support fixture are equipped with media filling channels.

[0007] Furthermore, the guide hole turning and precision boring station is equipped with several second machine tools. The spindle of the second machine tool is equipped with a spindle fixture, and the counterspindle is equipped with an overhanging boring bar. The overhanging end of the boring bar is equipped with a coaxial boring tool body. A movable servo clamp is set on the second machine tool between the spindle fixture and the boring tool body. The straightness of the boring tool body, servo clamp, and spindle fixture is ≤0.02mm. The second machine tool between the spindle fixture and the boring tool body is also equipped with a cutting tool for turning the guide hole.

[0008] Furthermore, the boring bar has an inverted conical inner hole along the axial direction. The smaller end of the inverted conical inner hole is close to the secondary shaft, and a shock-absorbing liner is provided on the inner wall of the inverted conical inner hole.

[0009] Furthermore, the front end of the boring bar is provided with three guide blocks along the circumference, the circular runout of the three guide blocks is ≤0.01mm, and the boring bar is provided with a cutting tip between two guide blocks. The cutting tip is opposite to another guide block, and the circumferential height of the cutting tip is 0.02mm higher than the opposite guide block.

[0010] A method for producing thin-walled tubular components for engines includes the following steps:

[0011] (1) The robot moves along the linear truss to transport the pipe blank from the loading station to the chamfering and precision turning station, and performs end processing, chamfering and turning on the station in sequence;

[0012] (2) After the frame processing is completed, the robot will transport the pipe blank to the guide hole and fine boring station in sequence to process the guide hole and inner hole, transport it to the inner hole inspection station for inner hole inspection, and temporarily store it in the transfer silo.

[0013] (3) The robot will send the pipe blanks in the transfer bin to the precision turning station for processing the pipe shape, transport them to the outer diameter detection station for size detection, and transport them to the threading and stop station for processing the end face, inner and outer chamfers, inner stop and threads to obtain thin-walled pipes.

[0014] (4) Finally, the thin-walled pipe is transported to the inner diameter detection and laser marking station by a robotic arm.

[0015] Further, in step (1), at the chamfering and precision machining station, the inner hole of the pipe blank is double-supported by two end face inner support clamps, and then the first machine tool processes the end face and chamfer of the pipe blank; after the chamfering is completed, the two end face inner support clamps loosen the pipe blank, and then the sub-spindle of the first machine tool continues to move forward, so that the tapered positioning sleeves of the main spindle and the sub-spindle press against the chamfer of the pipe blank, and then the first machine tool performs precision machining of the pipe blank at the station.

[0016] Furthermore, in step (3), at the precision machining station, the two ends of the pipe blank are positioned by the main spindle inner support fixture and the secondary spindle inner support fixture, and then the damping medium is filled into the pipe blank through the medium filling channel. If the damping medium leaks during the processing, the processing is paused for 3-4 seconds, the damping medium is replenished, and then the processing continues.

[0017] Furthermore, the inner diameter of the guide hole is 0.03 mm larger than the outer diameter of the boring bar body.

[0018] The beneficial effects of this invention are:

[0019] This invention enables the completion of chamfering and mounting within the same process through an internal support and double-top positioning method, reducing the deformation of the workpiece caused by the machine tool's internal support and avoiding affecting the positioning and cutting of the next process. For the internal and external machining of thin-walled pipes, an internal support mechanism with a filling medium is used for vibration reduction, which can realize the internal and external machining of different types of pipes. Through the cooperation of linear trusses and robotic arms, the workpiece is transferred between various workstations, realizing the automated machining of thin-walled pipes.

[0020] The present invention allows the entire production line to perform workpiece positioning, hole machining, shape machining, and thread machining at both ends of the workpiece without the use of customized machine tools. All machine tools can be ordinary CNC machine tools, which can save the production cycle of customized machine tools, make the entire production line quick to implement, and reduce equipment costs.

[0021] The production line of this invention can be used for the production of tubular parts with a large length-to-diameter ratio (e.g., 15:1) and a wall thickness difference of ≤0.10mm. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a schematic diagram of the automated production line of the present invention;

[0024] Figure 2 This is a schematic diagram of the end face internal support fixture;

[0025] Figure 3 This is a schematic diagram of the tapered positioning sleeve.

[0026] Figure 4 A schematic diagram of the main spindle internal support fixture and the secondary spindle internal support fixture;

[0027] Figure 5This is a schematic diagram of the third machine tool;

[0028] Figure 6 This is a schematic diagram of the boring bar structure;

[0029] Figure 7 This is a schematic diagram of the boring bar body.

[0030] Linear truss 1, robot arm 2, loading station 3, chamfering and precision turning station 4, guide hole turning and precision boring station 5, second machine tool 6, inner hole inspection station 7, transfer hopper 8, precision turning station 9, outer diameter inspection station 10, thread turning and stop station 11, inner diameter inspection and laser marking station 12, first machine tool 13, moving tie rod 14, tapered mandrel 15, inner support expansion sleeve 16, tapered positioning sleeve 17, third machine tool 18, main spindle inner support fixture 19, secondary spindle inner support fixture 20, medium filling channel 21, cutting tool 22, main spindle fixture 23, boring bar 24, inverted conical inner hole 25, shock-absorbing liner 26, boring tool body 27, servo clamp 28, guide block 29, cutting tool tip 30. Detailed Implementation

[0031] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0032] like Figure 1 As shown, an automated production line for thin-walled tubular components for engines includes a linear truss 1. A traveling robot arm 2 is mounted on the linear truss 1. Along the conveying direction of the thin-walled tubular components, a series of stations are arranged on one side of the linear truss 1: a loading station 3, a chamfering and precision turning station 4, a guide hole turning and precision boring station 5, an inner hole inspection station 7, a transfer hopper 8, a precision turning station 9, an outer diameter inspection station 10, a thread turning and stop station 11, and an inner diameter inspection and laser marking station 12. Each station is equipped with a corresponding machine tool, all of which are ordinary CNC lathes. The machine tools are placed perpendicular to the linear truss 1 at a 90° angle, with the headstock close to the linear truss 1 and the tailstock away from it. The machine tools have a rear-mounted chip removal mechanism. The robot arm 2 performs the functions of transferring, processing, and inspecting workpieces between different processes.

[0033] like Figure 1-3As shown, a first machine tool 13 is set on the chamfering and precision turning station 4. Both the main spindle and the auxiliary spindle of the first machine tool 13 are equipped with end face inner support fixtures. The end face inner support fixture includes a movable pull rod 14, a fixed tapered mandrel 15 and an inner support expansion sleeve 16. The movable pull rod 14 passes axially through the tapered mandrel 15 and is connected to the inner support expansion sleeve 16. The inner support expansion sleeve 16 is fitted on the outside of the free end of the tapered mandrel 15. A tapered positioning sleeve 17 is also fixed on the outside of the tapered mandrel 15. The tapered positioning sleeve 17 is located on the rear side of the inner support expansion sleeve 16. The tapered positioning sleeve 17 is provided with a tapered surface that matches the end chamfer of the thin-walled tube. When the end face inner support clamp needs to position the inner hole of the pipe blank, the moving pull rod 14 moves backward, driving the inner support expansion sleeve 16 to move towards the tapered mandrel 15, thereby causing the inner support expansion sleeve 16 to expand and thus position the inner hole of the pipe blank; when it is necessary to loosen the inner hole of the pipe blank, the moving pull rod 14 moves forward, and the inner support expansion sleeve 16 loosens the inner hole.

[0034] like Figure 1 and 4 As shown, a third machine tool 18 is provided on the precision machining station 9. The main spindle of the third machine tool 18 is provided with a main spindle inner support fixture 19, and the secondary spindle is provided with a secondary spindle inner support fixture 20. Both the main spindle inner support fixture 19 and the secondary spindle inner support fixture 20 are provided with a medium filling channel 21.

[0035] like Figure 1 and 5 As shown in Figure 7, multiple second machine tools 6 are arranged in parallel on the guide hole and precision boring station 5. A spindle clamp 23 is provided on the spindle of the second machine tool 6. The spindle clamp 23 is a circular clamp. An extended boring bar 24 is fixed on the sub-spindle. An inverted conical inner hole 25 is provided axially inside the boring bar 24. The smaller end of the inverted conical inner hole 25 is close to the sub-spindle. A shock-absorbing liner 26 is provided on the inner wall of the inverted conical inner hole 25. A boring bar body 27 with a coaxial axis is fixed on the boring bar 24. A movable servo clamp 28 is provided on the second machine tool 6 between the spindle clamp 23 and the boring bar body 27. The straightness of the boring bar body 27, the servo clamp 28 and the spindle clamp 23 is ≤0.02mm. The second machine tool 6 between the spindle fixture 23 and the boring tool body 27 is also equipped with a tool 22 for turning the guide hole. That is, the second machine tool 6 can be used to complete the machining of the guide hole and the fine boring hole, which is beneficial to improving the machining efficiency of the pipe blank.

[0036] The front end of the boring bar 27 is provided with three guide blocks 29 along the circumference. All guide blocks 29 are made of cemented carbide. The circular runout of the three guide blocks 29 is ≤0.01mm. A cutting tip 30 is fixed on the boring bar 27 between two guide blocks 29. The cutting tip 30 is opposite to another guide block 29. The circumferential height of the cutting tip 30 is 0.02mm higher than that of the opposite guide block 29.

[0037] A method for producing thin-walled tubular components for engines includes the following steps:

[0038] (1) The pipe blank is placed at the loading station 3, which is equipped with a reciprocating hopper. The robot arm 2 moves along the linear truss 1 to transport the pipe blank from the loading station 3 to the chamfering and precision turning station 4. At the chamfering and precision turning station 4, the inner hole of the pipe blank is double-supported by two end face inner support clamps. Then the first machine tool 13 processes the end face and chamfer of the pipe blank. After the chamfering is completed, the two end face inner support clamps release the pipe blank. Then the sub-spindle of the first machine tool 13 continues to move forward, so that the tapered positioning sleeves 17 of the main spindle and sub-spindle press against the chamfer of the pipe blank. Then the first machine tool 13 performs precision machining of the pipe blank. The workpiece is positioned by the tapered positioning sleeves 17 of the main spindle and sub-spindle. The machine tool then performs precision machining of the position, ensuring that the coaxiality of the positions processed at both ends is less than 0.05mm and that there is no deformation at both ends of the position.

[0039] (2) After the finishing stand is completed, the robot 2 transports the pipe blank to the guide hole and precision boring station 5. One end of the pipe blank is connected to the spindle fixture 23, and the other end is positioned by the servo clamp 28. First, the tool 22 is used to process the guide hole of the inner hole of the pipe blank. The length is customized. The inner diameter of the guide hole is 0.03mm larger than the size of the boring tool body 27. The spindle fixture 23 and the servo clamp 28 are coaxially positioned to ensure ≤0.02mm.

[0040] After the guide hole is machined, the inner hole is machined using the boring bar 24 and the boring body 27. After the inner hole is machined, the robot 2 transports the pipe blank to the inner hole inspection station 7 for inner hole inspection and temporarily stores it in the transfer silo 8.

[0041] (3) Robot 2 delivers the pipe blank from the transfer hopper 8 to the precision turning station 9 for pipe shape processing. At the precision turning station 9, the third machine tool 18 customizes the main spindle inner support fixture 19 and the secondary spindle inner support fixture 20 according to the boring process dimensions. Different proportions of inner support length are set according to the length of the part. After the thin-walled pipe is inner supported, there is no support in the middle part of the inner hole of the thin-walled pipe. During the processing, the cutting tool will vibrate. The medium filling channel 21 fills the pipe blank with liquid or gas and other damping media to prevent vibration and improve the product processing accuracy. If there is leakage of liquid or gas during the processing, it is permissible to pause for 3-4 seconds, replenish the liquid or gas and other damping media, and continue processing. The damping effect will be better. After the processing is completed, robot 2 transfers the product to the shape inspection station for dimension inspection. The cutting tool is compensated according to the inspection results in the production line.

[0042] After the outer shape is processed, the robotic arm 2 in the automated production line sends the pipe blank to the outer diameter inspection station 10 for inspection, and then transfers it to the threading and stop station 11. The threading process uses a general CNC lathe to process the threads at both ends of the thin-walled pipe. The first end of the pipe blank is clamped by the spindle, and the end of the pipe blank is positioned by the servo clamp. The pipe blank end face, inner and outer chamfers, inner stop, and threads are processed. After one end is processed, the robotic arm 2 grabs the pipe blank, turns it around and clamps it to realize the processing of the other end in the same step. After processing, the thin-walled pipe is obtained.

[0043] (4) Finally, the thin-walled pipe is transported to the inner diameter detection and laser marking station 12 by the robot arm 2. The laser marking station realizes the rotation marking of QR code and clear code. The detection station performs tool compensation on the cutting tool of the processing machine tool in a timely manner according to the detection results. The information in the production line is statistically analyzed by the MES system, and the operating status of each machine tool and the detection machine tool is monitored and the processing status is fed back in a timely manner.

[0044] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An automated production line for thin-walled tubular components used in engines, characterized in that: It includes a linear truss, on which a traveling robot arm is installed. Along the conveying direction of the thin-walled tubes on one side of the linear truss, there are sequentially arranged a loading station, a chamfering and precision turning station, a guide hole turning and precision boring station, an inner hole inspection station, a transfer hopper, a precision turning station, an outer diameter inspection station, a thread turning and stop station, and an inner diameter inspection and laser marking station. Each station is equipped with a corresponding machine tool, which is placed perpendicular to the linear truss. The chamfering and precision turning station is equipped with a first machine tool, and the main spindle and the secondary spindle of the first machine tool are both equipped with end face inner support fixtures; The end-face internal support fixture includes a movable pull rod, a fixed tapered mandrel, and an internal support expansion sleeve. The movable pull rod passes axially through the tapered mandrel and is connected to the internal support expansion sleeve. The internal support expansion sleeve is fitted onto the outside of the free end of the tapered mandrel. A tapered positioning sleeve is also fixed to the outside of the tapered mandrel. The tapered positioning sleeve is located behind the internal support expansion sleeve. The tapered positioning sleeve is provided with a tapered surface that matches the end chamfer of the thin-walled pipe fitting. When the end-face internal support fixture needs to position the inner hole of the pipe fitting blank, the movable pull rod moves backward, driving the internal support expansion sleeve to move towards the tapered mandrel, thereby expanding the internal support expansion sleeve and positioning the inner hole of the pipe fitting blank. When it is necessary to loosen the inner hole of the pipe fitting blank, the movable pull rod moves forward, and the internal support expansion sleeve loosens the inner hole. The guide hole and precision boring station is equipped with several secondary machine tools. The spindle of the secondary machine tool is equipped with a spindle fixture, and the secondary spindle is equipped with an overhanging boring bar. The overhanging end of the boring bar is equipped with a coaxial boring body. The secondary machine tool between the spindle fixture and the boring body is equipped with a movable servo clamp. The straightness of the boring body, servo clamp and spindle fixture is ≤0.02mm. The second machine tool between the spindle fixture and the boring bar is also equipped with a tool for turning the guide hole; the front end of the boring bar is provided with three guide blocks along the circumference, the circular runout of the three guide blocks is ≤0.01mm, and the boring bar between two guide blocks is provided with a tool tip, which is opposite to another guide block, and the circumferential height of the tool tip is 0.02mm higher than the opposite guide block.

2. The automated production line according to claim 1, characterized in that: A third machine tool is set up at the precision turning station. The main spindle of the third machine tool is equipped with a spindle inner support fixture, and the secondary spindle is equipped with a secondary spindle inner support fixture. Both the main spindle inner support fixture and the secondary spindle inner support fixture are equipped with media filling channels.

3. The automated production line according to claim 1, characterized in that: The boring bar has an inverted conical inner hole along the axial direction. The smaller end of the inverted conical inner hole is close to the secondary shaft, and a shock-absorbing liner is provided on the inner wall of the inverted conical inner hole.

4. A method for producing thin-walled tubular components for engines, characterized in that, The automated production line according to any one of claims 1-3 includes the following steps: (1) The robot moves along the linear truss to transport the pipe blank from the loading station to the chamfering and precision turning station, and performs end processing, chamfering and turning on the station in sequence; (2) After the frame processing is completed, the robot will transport the pipe blank to the guide hole and fine boring station in sequence to process the guide hole and inner hole, transport it to the inner hole inspection station for inner hole inspection, and temporarily store it in the transfer silo. (3) The robot will send the pipe blanks in the transfer bin to the precision turning station for processing the pipe shape, transport them to the outer diameter detection station for size detection, and transport them to the threading and stop station for processing the end face, inner and outer chamfers, inner stop and threads to obtain thin-walled pipes. (4) Finally, the thin-walled pipe is transported to the inner diameter detection and laser marking station by a robotic arm.

5. The production method according to claim 4, characterized in that, In step (1), at the chamfering and finishing stand position, the inner hole of the pipe blank is double-supported by two end face inner support clamps, and then the first machine tool processes the end face and chamfer of the pipe blank; after the chamfering is completed, the two end face inner support clamps loosen the pipe blank, and then the sub-spindle of the first machine tool continues to move forward, so that the tapered positioning sleeves of the main spindle and sub-spindle press against the chamfer of the pipe blank, and then the first machine tool performs finishing on the stand position of the pipe blank.

6. The production method according to claim 4, characterized in that, In step (3), at the precision machining station, the two ends of the pipe blank are positioned by the main spindle inner support fixture and the secondary spindle inner support fixture. Then, the damping medium is filled into the pipe blank through the medium filling channel. If the damping medium leaks during the processing, the processing is paused for 3-4 seconds, the damping medium is replenished, and then the processing continues.

7. The production method according to claim 4, characterized in that, The inner diameter of the guide hole is 0.03 mm larger than the outer diameter of the boring bar.

Images