A flexible automated machining unit and method for combined turning and milling production.

Abstract

A flexible automated machining unit and method for mixed turning and milling production line, relating to the fields of machining automation and intelligent manufacturing, includes a first roughing CNC lathe and a second roughing CNC lathe, a first finishing CNC lathe and a second finishing CNC lathe, arranged back-to-back. The first roughing CNC lathe and the first finishing CNC lathe, as well as the second roughing CNC lathe and the second finishing CNC lathe, are arranged side-by-side. A CNC milling machine is located on the side of the first finishing CNC lathe and the second finishing CNC lathe away from the first roughing CNC lathe and the second roughing CNC lathe, forming a U-shaped layout. A six-axis articulated robot is positioned in the middle of the U-shaped layout, and a stepped material carriage is positioned at the opening of the U-shaped layout. This overcomes the problems of poor quality consistency, low production efficiency, and insufficient production balance in existing production models.

Description

Technical Field

[0001] This invention relates to a flexible automated machining unit and method for milling and turning, belonging to the field of mechanical processing automation and intelligent manufacturing technology. Background Technology

[0002] A gas generator is a device that produces combustion gas at a certain pressure and temperature as the working fluid for a turbine. End caps, as an important component of the main structure of a gas generator, are characterized by high material strength, numerous structural features, and complex manufacturing processes. Typical end caps include four types: upper and lower end caps, front and rear end caps, etc. Figure 1 As shown, all four parts are made of the same high-strength steel 30CrMnSi and have similar structural features, generally being multi-groove, multi-hole rotating bodies, but their structural dimensions and tolerance requirements differ. They also have similar manufacturing processes, typically requiring rough turning, finish turning, milling, drilling, and threading. In conventional production, four types of parts are machined one by one using CNC machine tools according to the production process. Each process is highly dependent on manual operation; clamping, alignment, tool setting, and disassembly of parts in a single process, as well as the transfer between processes, all require manual operation, resulting in low production efficiency and high production costs. When the number of parts reaches a certain level (ranging from tens to hundreds), the consistency of machining quality, production capacity, and delivery cycle become the main bottlenecks.

[0003] This invention provides a flexible automated machining unit with a milling and turning line, which simultaneously produces multiple types of end caps by using a milling and turning line and automation. While ensuring product quality consistency, it achieves high-quality, high-efficiency and balanced production of multiple types of end caps, and enables rapid changeover of parts with similar specifications. Summary of the Invention

[0004] The technical problem solved by this application is to overcome the shortcomings of the prior art and provide a flexible automated machining unit and method for milling and turning production lines, which overcomes the problems of poor quality consistency, low production efficiency and insufficient production balance in the existing production mode.

[0005] Furthermore, it enables fully automated processing of parts such as upper and lower heads, and front and rear heads. All machining processes, from rough turning, finish turning, milling, drilling, and threading, are completed within the automated unit, from raw material to finished product. This breaks the traditional one-to-one strong matching relationship between humans and equipment, allowing one person to operate an entire automated processing unit, improving processing efficiency and quality stability. Based on this, rapid changeover of parts with similar specifications can be achieved.

[0006] The technical solution provided in this application is as follows:

[0007] A flexible automated machining unit for combined turning and milling production includes a first roughing CNC lathe, a second roughing CNC lathe, a first finishing CNC lathe, a second finishing CNC lathe, a CNC milling machine, a six-axis articulated robot, a stepped material carriage, a workpiece buffer rack, and a control system.

[0008] The first roughing CNC lathe and the second roughing CNC lathe are arranged back-to-back, the first finishing CNC lathe and the second finishing CNC lathe are arranged back-to-back, and the first roughing CNC lathe and the first finishing CNC lathe are arranged side by side, the second roughing CNC lathe and the second finishing CNC lathe are arranged side by side, and the CNC milling machine is located on the side of the first finishing CNC lathe and the second finishing CNC lathe away from the first roughing CNC lathe and the second roughing CNC lathe, so that the first roughing CNC lathe, the second roughing CNC lathe, the first finishing CNC lathe, the second finishing CNC lathe and the CNC milling machine form a U-shaped layout;

[0009] A six-axis articulated robot is positioned in the middle of the U-shaped layout, while a stepped material cart is positioned at the opening of the U-shaped layout.

[0010] The workpiece buffer rack is used to hold materials, including finish-turned blanks and rough-turned blanks. A six-axis articulated robot is used for the movement, loading, and unloading of materials between the first rough-turning CNC lathe, the second rough-turning CNC lathe, the first finish-turning CNC lathe, the second finish-turning CNC lathe, a CNC milling machine, a stepped material carriage, and the workpiece buffer rack. The first and second rough-turning CNC lathes are used to rough-machine the end faces, outer contours, and inner cavity contours of the rough-turned blanks to obtain rough-turned parts. After heat treatment, the rough-turned parts are used to obtain finish-turned blanks. The first and second finish-turning CNC lathes perform precise-dimensional finish-machined end faces, outer contours, and inner cavity contours on the finish-turned blanks to obtain finish-turned parts. The CNC milling machine then performs finish milling on the finish-turned parts to obtain the finished product. The control system is used to control the six-axis articulated robot to move materials within the U-shaped layout for processing.

[0011] The six-axis articulated robot is connected to the ground via a seventh-axis moving guide rail, which drives the six-axis articulated robot to move back and forth along the direction from the stepped material cart to the CNC milling machine.

[0012] The stepped material car includes a roughing stepped material car and a finishing stepped material car. The roughing stepped material car and the finishing stepped material car are arranged side by side at the opening of the U-shaped layout. The roughing stepped material car is used to place the roughing blanks of the upper end and the lower end, or the roughing blanks of the front end and the rear end. The finishing stepped material car is used to place the finishing blanks of the upper end and the lower end, or the finishing blanks of the front end and the rear end.

[0013] The upper surface of the stepped material cart is set with multiple steps of increasing height, and the upper surface of each step is set with storage positions for storing materials.

[0014] Five workpiece buffer racks are provided: one workpiece buffer rack is arranged on the side of the first roughing CNC lathe facing the second roughing CNC lathe, one workpiece buffer rack is arranged on the side of the second roughing CNC lathe facing the first roughing CNC lathe, one workpiece buffer rack is arranged on the side of the first finishing CNC lathe facing the second finishing CNC lathe, one workpiece buffer rack is arranged on the side of the second finishing CNC lathe facing the first finishing CNC lathe, and one workpiece buffer rack is arranged on the side of the CNC milling machine facing the six-axis articulated robot; each workpiece buffer rack has two buffer stations and one column.

[0015] The first roughing CNC lathe, the second roughing CNC lathe, the first finishing CNC lathe, and the second finishing CNC lathe are equipped with automatic opening and closing doors on their rear sides for transferring and exchanging materials from the rear. The CNC milling machine has an automatic opening and closing door on the side facing the six-axis articulated robot for transferring and exchanging materials from the side.

[0016] For the precision-machined blanks of the upper and lower heads, the large end of the precision-machined blank of the upper head has an internal thread, and the large end of the precision-machined blank of the lower head has an external thread. In the first precision-machined CNC lathe and the second precision-machined CNC lathe, one is equipped with an external clamping fixture, and the other is equipped with an internal support fixture.

[0017] For the precision-machined blanks of the front and rear heads, the large and small ends of the precision-machined blanks of the front head have internal threads, and the large end of the precision-machined blanks of the rear head has internal threads and the outer surface of the small end has a convex ring. Both the first precision-machined CNC lathe and the second precision-machined CNC lathe are equipped with external clamping fixtures.

[0018] A flexible automated machining method for milling-turning integrated production line, using any of the aforementioned flexible automated machining units for milling-turning integrated production line, includes:

[0019] S1: The six-axis articulated robot moves the roughing blank from the roughing step car to the first roughing CNC lathe or the second roughing CNC lathe for roughing to obtain the roughing part. The six-axis articulated robot then moves the roughing part to the roughing step car.

[0020] S2: The six-axis articulated robot moves the precision-machined blank from the precision-machined stepped material car to the first precision-machined CNC lathe and / or the second precision-machined CNC lathe for precision machining to obtain the precision-machined part. Then, the six-axis articulated robot moves the precision-machined part to a CNC milling machine for precision milling to obtain the product. The six-axis articulated robot moves the product back to the precision-machined stepped material car.

[0021] Step S1 includes: a six-axis articulated robot transporting the rough-turned blank from the rough-turned stepped material car to the buffer station of the workpiece buffer rack; the six-axis articulated robot then loading the rough-turned blank from the buffer station of the workpiece buffer rack into a machining station of the first rough-turned CNC lathe or the second rough-turned CNC lathe, machining the end face and outer contour to obtain an intermediate rough-turned part; the six-axis articulated robot moving the intermediate rough-turned part to the column of the workpiece buffer rack for flipping; the six-axis articulated robot then loading the flipped intermediate rough-turned part into another machining station of the first rough-turned CNC lathe or the second rough-turned CNC lathe, machining the end face and inner cavity contour to obtain a rough-turned part; the six-axis articulated robot transporting the rough-turned part to the buffer station of the workpiece buffer rack; and finally, transporting the rough-turned part back to the rough-turned stepped material car.

[0022] If the upper and lower end caps are precision-machined blanks, in step S2, the precision-machined blank of the upper end cap is loaded into a precision-machined CNC lathe with an internal support fixture. The precision-machined CNC lathe is either a first precision-machined CNC lathe or a second precision-machined CNC lathe. The end face and outer contour with precise dimensions are machined to obtain an intermediate precision-machined part. A six-axis articulated robot transports the intermediate precision-machined part to the column of the workpiece buffer rack for flipping. The six-axis articulated robot then loads the flipped intermediate precision-machined part into a precision-machined CNC lathe with an external clamping fixture. The end face, inner cavity contour and internal thread with precise dimensions are machined to obtain a precision-machined part. A CNC milling machine performs precision milling on the precision-machined part to obtain the product.

[0023] The lower end cap blank is transported to the column of the workpiece buffer rack for flipping. The six-axis articulated robot then loads the flipped intermediate precision-machined part into a precision-machined CNC lathe with an external clamping fixture. The end face and inner cavity contour with precise dimensions are machined to obtain the intermediate precision-machined part. The six-axis articulated robot then transports the intermediate precision-machined part to the column of the workpiece buffer rack for flipping. The six-axis articulated robot then loads the flipped intermediate precision-machined part into a precision-machined CNC lathe with an internal support fixture. The outer contour and external threads with precise dimensions are machined to obtain the precision-machined part. The CNC milling machine performs precision milling on the precision-machined part to obtain the product.

[0024] If the front end and rear end are precision-machined blanks, in step S2, the precision-machined blank of the front end is loaded into a precision-machined CNC lathe with an external clamping fixture, and the end face, outer contour, inner cavity contour and internal thread of the large end position with precise dimensions are machined. After the six-axis articulated robot flips the precision-machined blank of the front end, it is fed into the same precision-machined CNC lathe to machine the end face, outer contour, inner cavity contour and internal thread of the small end position with precise dimensions to obtain the precision-machined part. The CNC milling machine performs precision milling on the precision-machined part to obtain the product.

[0025] The rear end blank is loaded into a precision CNC lathe with an external clamping fixture. The large end face, outer contour, inner cavity contour, and internal thread are machined with precise dimensions. The six-axis articulated robot flips the front end blank and feeds it into the same precision CNC lathe to machine the small end face, outer contour, and inner cavity contour with precise dimensions, thus obtaining the precision-machined part. The CNC milling machine then performs precision milling on the precision-machined part to obtain the product.

[0026] In summary, this application includes at least the following beneficial technical effects:

[0027] It can achieve automated and efficient processing of upper and lower end caps, front and rear end caps. By analyzing production data, the flexible automated machining unit with milling and turning lines improves the processing efficiency of upper and lower end caps by 2.6 times and reduces processing costs by 55%, and improves the processing efficiency of front and rear end caps by 2.3 times and reduces production costs by 47%. In addition, the number of operators has been reduced from 5 in conventional processing methods to 1, freeing up human resources and significantly reducing labor costs. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of a typical head-type part, where a is the upper head (outer envelope size Φ166mm×78.5mm); b is the lower head (outer envelope size Φ100mm×80mm); c is the front head (outer envelope size Φ124mm×80mm); and d is the rear head (outer envelope size Φ124mm×91mm).

[0029] Figure 2 This is a layout diagram of a flexible automated machining unit that integrates turning and milling.

[0030] Figure 3 This is a schematic diagram of a robot end effector.

[0031] Figure 4 This is a schematic diagram of a stepped material cart.

[0032] Figure 5 This is the rough machining path for the upper and lower heads.

[0033] Figure 6 This refers to the rough machining of the upper end cap.

[0034] Figure 7 This pertains to the rough machining of the lower end cap.

[0035] Figure 8 This describes the finishing path for the upper and lower end caps.

[0036] Figure 9 This refers to the finishing process of the upper end cap.

[0037] Figure 10 This pertains to the finishing of the lower end cap.

[0038] Figure 11 This describes the rough machining path for the front and rear end caps.

[0039] Figure 12 This refers to the rough machining of the upper end cap.

[0040] Figure 13 This pertains to the rough machining of the lower end cap.

[0041] Figure 14 This describes the finishing path for the front and rear end caps.

[0042] Figure 15 This refers to the finishing process of the front end cap.

[0043] Figure 16 This pertains to the finishing process of the post-cap.

[0044] Explanation of icon numbers:

[0045] 1- First roughing CNC lathe (OP10), used for roughing; 2- Second roughing CNC lathe (OP20), used for roughing; 3- First finishing CNC lathe (OP30), used for finishing; 4- Second finishing CNC lathe (OP40), used for finishing; 5- CNC milling machine OP50, used for milling and drilling; 6- Six-axis articulated robot, used for automatic transfer of blanks and workpieces; 7- Roughing step-type material car, used for storing roughing blanks / semi-finished products; 8- Finishing step-type material car, used for storing roughing blanks / semi-finished products; 9- Workpiece buffer rack, used for temporary storage or flipping of workpieces, where ○ is the workpiece buffer position and ● is the workpiece flipping position; 10- Main control cabinet).

[0046] 01-Claw A; 02-Claw copper pad; 03-Workpiece; 04-Claw B. Detailed Implementation

[0047] The invention will be further explained below with reference to the processing of the upper and lower end caps as an example in conjunction with the accompanying drawings.

[0048] This application discloses a flexible automated machining unit that integrates turning and milling, such as... Figure 1 As shown, it is used for machining the upper head, front head, rear head, and right head, as follows. Figure 2 As shown, the flexible automated machining unit includes: a first roughing CNC lathe 1 (OP10), a second roughing CNC lathe 2 (OP20), a first finishing CNC lathe 3 (OP30), a second finishing CNC lathe 4 (OP40), a CNC milling machine 5 (OP50), a six-axis articulated robot 6, a stepped material carriage, five workpiece buffer racks 9, a control system, and supporting safety protection systems and accessories. The control system is integrated into the main control cabinet 10.

[0049] Two roughing CNC lathes (first roughing CNC lathe 1 (OP10) and second roughing CNC lathe 2 (OP20)) are arranged back-to-back, and two finishing CNC lathes (first finishing CNC lathe 3 (OP30) and second finishing CNC lathe 4 (OP40)) are arranged back-to-back. The first roughing CNC lathe 1 and the first finishing CNC lathe 3 are arranged side by side, the second roughing CNC lathe 2 and the second finishing CNC lathe 4 are arranged side by side, and a CNC milling machine 5 is set on the side of the two finishing CNC lathes away from the roughing CNC lathes. The first roughing CNC lathe 1 (OP10), the second roughing CNC lathe 2 (OP20), the first finishing CNC lathe 3 (OP30), the second finishing CNC lathe 4 (OP40), and one CNC milling machine 5 form a "U-shaped" process layout, which together constitutes the processing subsystem of the flexible automated machining unit with mixed turning and milling. Its structure is compact and facilitates the transfer of blanks and workpieces between processes.

[0050] A six-axis articulated robot 6 is positioned in the middle of a U-shaped layout consisting of five machine tools, with stepped material carts positioned at the opening of the "U" unit. The six-axis articulated robot 6 is used for workpiece transfer between the stepped material carts and the machine tools, as well as between the machine tools. The stepped material carts include a roughing stepped material cart 7 and a finishing stepped material cart 8, which are arranged side-by-side at the opening of the "U" unit for loading and unloading materials within the unit, and for exchanging raw materials, semi-finished products, and finished products inside and outside the unit.

[0051] The six-axis articulated robot 6 is a six-axis articulated industrial robot with an additional seventh-axis moving guide rail. The six-axis robot 6 is connected to the ground via this seventh-axis moving guide rail, which drives the robot 6 to move back and forth along the direction from the stepped material cart to the CNC milling machine 5, achieving overall translation within the unit and expanding the robot's material handling range. The robot's end effector adopts a dual-jaw design, with jaws A01 and B04 for gripping workpiece 03, capable of gripping diameters of Φ100mm~Φ140mm and Φ130mm~Φ170mm respectively, adapting to gripping two different diameter end cap parts. The inner side of the robot's end effector jaws is equipped with softer brass material jaw pads 02 to prevent damage to the surface of the finished workpiece. Figure 3 As shown.

[0052] To achieve automated loading and unloading of products, the machine tools were modified by adding automatic opening and closing doors to the back of the CNC lathes and the sides of the CNC milling machines. The automatic opening and closing doors are driven by cylinders controlled by a PLC. Specifically, the machine tools (including two roughing CNC lathes and two finishing CNC lathes) have an operation panel on the front and an automatic opening and closing door on the back for transferring and exchanging workpieces from the back. One CNC milling machine has an automatic opening and closing door on its left side for transferring and exchanging workpieces from the side. The two roughing CNC lathes use 10-position rotary turrets according to machining requirements; the two finishing CNC lathes use 12-position rotary turrets according to machining requirements. Based on the product machining dimensions, all four CNC lathes use 10-inch three-jaw chucks. To ensure installation accuracy, auxiliary positioning blocks are installed on the turrets. Two pneumatic three-jaw chucks are installed on the CNC milling machine's worktable for product clamping.

[0053] like Figure 4 As shown, the roughing-carrying stepped material cart 7 and the finishing-carrying stepped material cart 8 adopt a 6-level × 4-row stepped design, which can effectively avoid interference when the robot grasps materials. Based on the product processing cycle calculation results, the material cart storage positions are designed as "12+12", that is, 12 upper heads and 12 lower heads or 12 front heads and 12 rear heads, which can meet the needs of continuous full-set processing for one day. That is, both the roughing-carrying stepped material cart 7 and the finishing-carrying stepped material cart 8 include a car body, the upper surface of which is stepped, and each step's upper surface is equipped with a storage position.

[0054] like Figure 2 As shown, five workpiece buffer racks 9 are arranged in a hierarchical manner at the automatic opening and closing doors on the back or side of the machine tool. The workpiece buffer racks 9 are used for temporary storage or flipping of workpieces; specifically, one workpiece buffer rack 9 is arranged on the side of the first roughing CNC lathe 1 facing the second roughing CNC lathe 2, one workpiece buffer rack 9 is arranged on the side of the second roughing CNC lathe 2 facing the first roughing CNC lathe 1, one workpiece buffer rack 9 is arranged on the side of the first finishing CNC lathe 3 facing the second finishing CNC lathe 4, one workpiece buffer rack 9 is arranged on the side of the second finishing CNC lathe 4 facing the first finishing CNC lathe 3, and one workpiece buffer rack 9 is arranged on the side of the CNC milling machine 5 facing the six-axis robot 6. Each workpiece buffer rack has two buffer stations and one column. Each CNC lathe workpiece buffer rack has two buffer stations, one for storing blanks to be processed and the other for storing semi-finished products processed by the machine tool. The workpiece buffer rack has a 500mm high column for the articulated robot to flip parts. The workpiece buffer rack of the CNC milling machine is equipped with a tilting column for storing finished end cap parts.

[0055] The unit control system uses Siemens PLCs and is integrated into the control cabinet. It is equipped with an HMI touchscreen for viewing equipment operating status and enabling human-machine interaction.

[0056] The unit's protective fence is equipped with a safety gate that is linked to an emergency stop signal. When the gate is opened, the unit immediately stops operating.

[0057] Operation flow of the flexible automated machining unit with milling and turning lines:

[0058] (1) During the production preparation stage, the two stepped material carts are filled with raw material blanks and heat-treated semi-finished blanks respectively, and pushed into the unit. The position of the stepped material carts is fixed by the ground positioning mechanism. The tools in the CNC lathe and CNC milling machine are configured, the automatic machining program is run, and the robot is called to load materials.

[0059] (2) Start the robot running program. The robot loads materials for the CNC lathe one by one according to the machine tool calling order and places a material reserve at the workpiece buffer rack.

[0060] (3) After the current workstation in the CNC lathe is finished, the robot grabs the material and flips the part in the workpiece buffer rack, and then sends it back to the machine tool for processing.

[0061] (4) After the two roughing machines have finished processing, the robot picks up the material and puts it back into the material car. At this time, the roughing machine sends a call signal, and the robot responds to the call signal again, loads the material into the machine, and replenishes the material in the workpiece buffer rack. The semi-finished product after roughing will be sent to heat treatment. After returning, it can be loaded into the finishing car as a blank to be processed.

[0062] (5) After the two precision lathes have completed the machining, the robot picks up the material and feeds it into the CNC milling machine for precision milling.

[0063] (6) After precision milling is completed, the robot picks up the material and sends it back to the material cart;

[0064] (7) The process is repeated in the above cycle until all the blanks in the material cart are processed. The processing is fully automatic and requires no manual operation.

[0065] The OP10 machine tool performs rough turning of the lower end cap, the OP20 machine tool performs rough turning of the upper end cap, the OP30 and OP40 each perform one station of the upper and lower end caps and then cross over to perform another station, and the OP50 performs finish milling of the upper and lower end caps. The robot completes the product transfer between each station.

[0066] In the appendix Figure 4 and 5 The material carts shown are used to hold the blanks for the upper and lower end caps. In the roughing step-type material cart 7, the upper three layers (section B) hold the upper end cap blanks, and the lower three layers (section A) hold the lower end cap blanks. In the finishing step-type material cart 8, the upper three layers (section D) hold the heat-treated finishing blanks for the upper end caps, and the lower three layers (section C) hold the heat-treated finishing blanks for the lower end caps. The material carts are pushed into the unit and secured in position with pins. The safety door is then closed. The step-type design effectively avoids interference issues when the robotic arm is holding the parts.

[0067] The machine tool executes the automatic processing main program, then starts executing the station cleaning subroutine, and then sends a signal to the PLC through the machine tool's custom M command to call the robot to unload the material.

[0068] The robot's automatic operation program is initiated, and the robot begins responding to call signals to load materials into the machine tool. First, it picks up the blank from the material cart and places it into the workpiece buffer rack, then loads it into the machine tool. After the buffer position is cleared, the robot automatically replenishes the material by picking up blanks from the material cart and placing them into the buffer position.

[0069] Inside the machine tool, auxiliary positioning blocks perform secondary positioning of the clamped blanks to ensure clamping accuracy. After the OP10 and OP20 machine tools complete processing at the first station, the robot grabs the material, flips the part on the workpiece buffer rack column, and feeds it back into the machine tool for processing. After processing, the robot picks up the material, places it in the workpiece buffer rack where semi-finished products are stored, and then puts it back into the material cart.

[0070] like Figure 5 As shown, the rough machining trajectory of the lower end cap is as follows: ① The robot transports the blank material from area A of the material cart to the OP10 buffer table; ② The robot loads the blank material on the buffer table into the machine tool chuck, ready to execute the machining program; ③ After the machining at station one is completed, the robot removes the material and places it on the tilting column; ④ The robot completes the material reversal through the tilting column and sends it into the machine tool for machining at station two; ⑤ After the machining at station two is completed, the robot removes the material and places it on the finished product (rough machining) buffer table; ⑥ The robot returns the finished product (rough machining) to its original position on the material cart.

[0071] Description of the rough machining trajectory for the upper head: ① The robot transports the blank material from area B of the material cart to the OP20 buffer table; ② The robot loads the blank material from the buffer table into the machine tool chuck, ready to execute the machining program; ③ After the machining at station one is completed, the robot removes the material and places it on the tilting column; ④ The robot completes the material reversal through the tilting column and sends it into the machine tool for machining at station two; ⑤ After the machining at station two is completed, the robot removes the material and places it on the finished product (rough machining) buffer table; ⑥ The robot returns the finished product (rough machining) to its original position on the material cart.

[0072] like Figure 6 As shown, the rough turning process of the upper head is as follows: ① The upper head is machined at station 1 of the OP20 machine tool, with the end face and outer contour machined, and the single-sided allowance is 2mm; ② When the robot takes out the part and flips it over, the machine tool (automatically) runs the cleaning fixture program; ③ After turning and clamping, the end face is machined, the bottom hole of the inner cavity is drilled, and the stepped hole of the inner cavity is machined, with the single-sided allowance controlled at 2mm.

[0073] like Figure 7As shown, the rough turning process of the lower head is as follows: ① The lower head is machined at station 1 of the OP10 machine tool, including turning the end face, turning the outer contour, drilling the internal cavity through hole, and turning the inner cavity contour, with a single-sided allowance of 2mm; ② When the robot arm takes out the part and flips it over, the machine tool (automatically) runs the cleaning fixture program; ③ After turning and clamping, the end face, the outer conical surface, and the end face conical hole are machined, with a single-sided allowance of 2mm.

[0074] like Figure 6 As shown, after completing the first station of machining on the OP30 and OP40 machine tools, the robot picks up the workpiece and places it on the flipping column of the workpiece buffer rack on the opposite machine tool, then switches machine tools to perform finish turning at another station. After machining, the robot picks up the workpiece, places it on the workpiece buffer rack, and then sends it to the milling machine for finish milling. The milling machine chuck uses the weight of the workpiece for positioning, eliminating the need for auxiliary positioning blocks. After machining, the robot picks up the workpiece, places it on the workpiece buffer rack, and then sends it back to the material cart.

[0075] The unit repeats the above process in a loop until all the blanks in the material cart have been processed.

[0076] like Figure 8 As shown, the finishing trajectory of the lower end cap is as follows: ① The robot transports the blank material from area C of the material cart to the OP30 buffer table; ② The robot loads the blank material from the buffer table into the machine tool chuck, ready to execute the machining program; ③ After the machining at station one is completed, the robot removes the material and places it on the OP40 machine tool tilting column; ④ The robot reverses the direction of the material by using the tilting column and sends it to the OP40 machine tool for machining at station two; ⑤ After the machining at station two is completed, the robot removes the material and places it on the finished product (finish turning) buffer table; ⑥ The robot loads the finished product (finish turning) into the OP50 machine tool chuck, ready to perform finish milling; ⑦ After finish milling is completed, the robot removes the finished product and places it on the buffer table; ⑧ The robot returns the finished product from the buffer table to its original position on the material cart.

[0077] Description of the finishing trajectory for the upper end cap: ① The robot transports the blank material from area D of the material cart to the OP40 buffer table; ② The robot loads the blank material from the buffer table into the machine tool chuck, ready to execute the machining program; ③ After the machining at station one is completed, the robot removes the material and places it on the OP30 machine tool tilting column; ④ The robot reverses the direction of the material via the tilting column and sends it to the OP30 machine tool for machining at station two; ⑤ After the machining at station two is completed, the robot removes the material and places it on the finished product (finish turning) buffer table; ⑥ The robot loads the finished product (finish turning) into the OP50 machine tool chuck, ready to execute the finishing milling at station one; ⑦ After the finishing milling at station one is completed, the robot removes the finished product and places it on the tilting column; ⑧ The robot reverses the direction of the material via the tilting column and sends it to the machine tool four-axis rotary table, ready to execute the finishing milling at station two; ⑨ After the finishing milling at station two is completed, the robot removes the finished product and places it on the buffer table; ⑩ The robot returns the finished product from the buffer table to its original position on the material cart.

[0078] During the precision machining of the upper and lower end caps, there are situations where machine tools need to be changed. Because the upper and lower end caps have internal and external thread structures respectively, and the threads cannot be directly clamped, two types of clamps, one external clamp and one internal support, are designed for the OP30 and OP40 machine tools respectively. By changing the workstation, the clamping damage to the thread features is avoided.

[0079] like Figure 10 As shown, the finishing process of the lower end cap is as follows: ① The lower end cap is first clamped on the OP30 machine tool using an external clamping method, and the large end face, sealing burrs, and inner cavity are machined to the required dimensions; ② The robot arm sends the part to the OP40 machine tool, where it is fixed using an internal support method, and the inner hole and threads are machined to the required dimensions; ③ After finishing turning, the part is sent to a milling machine for finishing milling, including milling squares, drilling, tapping, etc.

[0080] like Figure 9 As shown, the finishing process for the upper head is as follows: ① The upper head is first clamped on the OP40 machine tool with an internal support, and the small end face and outer contour are machined to the required dimensions; ② The robot arm sends the part to the OP30 machine tool, where it is fixed with an external clamp, and the internal cavity stepped hole, thread relief groove, thread, and sealing groove are machined to the required dimensions; ③ After finishing, the part is sent to a milling machine for finishing milling, including milling flat surfaces, milling square surfaces, drilling holes, and milling threads.

[0081] If a product change is required, such as to process a complete set of front and rear end caps, simply adjust the fixtures and cutting tools inside the machine tool accordingly, call the corresponding machining program and robot program, and replace the pallet in the material cart. The machining paths for the front and rear end caps are attached. Figure 11 As shown.

[0082] like Figure 11 As shown, the specific path is as follows: Description of the rough machining trajectory of the rear end cap: ① The robot transports the blank material from area A of the material cart to the OP10 buffer table; ② The robot loads the blank material on the buffer table into the machine tool chuck, ready to execute the machining program; ③ After the machining at station one is completed, the robot takes out the material and places it on the tilting column; ④ The robot completes the material reversal through the tilting column and sends it into the machine tool for machining at station two; ⑤ After the machining at station two is completed, the robot takes out the material and places it on the finished product (rough machining) buffer table; ⑥ The robot puts the finished product (rough machining) back to the original position of the material cart.

[0083] Description of the rough machining trajectory for the front end cap: ① The robot transports the blank material from area B of the material cart to the OP20 buffer table; ② The robot loads the blank material from the buffer table into the machine tool chuck, ready to execute the machining program; ③ After the machining at station one is completed, the robot removes the material and places it on the tilting column; ④ The robot completes the material reversal through the tilting column and sends it into the machine tool for machining at station two; ⑤ After the machining at station two is completed, the robot removes the material and places it on the finished product (rough machining) buffer table; ⑥ The robot returns the finished product (rough machining) to its original position on the material cart.

[0084] like Figure 13As shown, the rough turning process of the rear end cap is as follows: ① The rear end cap is machined at station 1 of the OP10 machine tool, with the end face, outer contour, and bottom hole drilled, with a single-sided allowance of 2mm; ② When the robot arm takes out the part and flips it over, the machine tool (automatically) runs the cleaning fixture program; ③ After turning the part over and clamping it at station 2 of the machine tool, the end face, outer contour, bottom hole drilled, inner cavity conical surface and stepped hole are machined, with a single-sided allowance of 2mm controlled.

[0085] like Figure 12 As shown, the rough turning process of the front end cap is as follows: ① The front end cap is machined at station 1 of the OP20 machine tool, with the end face, outer contour, and bottom hole drilled, with a single-sided allowance of 2mm; ② When the robot arm takes out the part and flips it over, the machine tool (automatically) runs the cleaning fixture program; ③ After turning the part over and clamping it at station 2 of the machine tool, the end face, outer contour, bottom hole drilled, and stepped hole drilled in the inner cavity are machined, with a single-sided allowance of 2mm controlled.

[0086] like Figure 14 As shown, the finishing trajectory of the rear end cap is as follows: ① The robot transports the raw material from area C of the material cart to the OP30 buffer table; ② The robot places the material on the buffer table onto the OP50 tilting column; ③ The robot reverses the material via the tilting column and sends it into the OP30 machine tool for processing at station one; ④ After processing at station one is completed, the robot removes the material and places it onto the machine tool's tilting column; ⑤ The robot reverses the material via the tilting column and sends it into the OP30 machine tool for processing at station two; ⑥ After processing at station two is completed, the robot removes the material and places it onto the finished product (finish turning) buffer table; ⑦ The robot loads the finished product (finish turning) into the OP50 machine tool chuck, ready for finish milling; ⑧ After finish milling is completed, the robot removes the finished product and places it onto the buffer table; ⑨ The robot returns the finished product from the buffer table to its original position on the material cart.

[0087] Description of the finishing trajectory for the front end cap: ① The robot transports the raw material from area D of the material cart to the OP40 buffer table; ② The robot feeds the material on the buffer table into the OP40 machine tool for processing at station one; ③ After processing at station one is completed, the robot removes the material and places it on the machine tool's tilting column; ④ The robot reverses the direction of the material via the tilting column and feeds it into the OP40 machine tool for processing at station two; ⑤ After processing at station two is completed, the robot removes the material and places it on the finished product (finish turning) buffer table; ⑥ The robot picks up the finished product and places it onto the OP40 tilting column; ⑦ The robot reverses the direction of the material via the tilting column and feeds it into the OP50 machine tool chuck, ready for finish milling; ⑧ After finish milling is completed, the robot removes the finished product and places it on the buffer table; ⑨ The robot returns the finished product on the buffer table to its original position on the material cart.

[0088] like Figure 16As shown, the finishing process of the rear end cap is as follows: ① The rear end cap is machined at station one on the OP30 machine tool, including turning the large end face, turning the outer contour, turning the inner cavity stepped hole and conical surface, thread relief groove, thread, and sealing groove to the dimensions; ② After being flipped by the robot arm, it is machined at station two, turning the small end face, outer contour, center hole, and outer conical surface to the dimensions; ③ After finishing turning, it is sent to the milling machine for finishing milling, including milling the elongated hole, threaded bottom hole, chamfering, tapping, etc.

[0089] like Figure 15 As shown, the finishing process of the front end cap is as follows: ① The front end cap is machined at station one on the OP40 machine tool, including turning the large end face, turning the inner cavity stepped hole, thread relief groove, thread, and sealing groove to the dimensions; ② After being flipped by the robot arm, it is machined at station two, turning the small end face, outer contour, threaded bottom hole, thread, etc. to the dimensions; ③ After finishing turning, it is sent to the milling machine for finishing milling, including milling hexagons, drilling threaded bottom holes, chamfering, tapping, etc.

[0090] The present application has been described in detail above with reference to specific embodiments and exemplary examples; however, these descriptions should not be construed as limiting the present application. Those skilled in the art will understand that various equivalent substitutions, modifications, or improvements can be made to the technical solutions and implementation methods of the present application without departing from the spirit and scope of the present application, and all such modifications and improvements fall within the scope of the present application. The scope of protection of the present application is determined by the appended claims.

[0091] The contents not described in detail in this application specification are common knowledge to those skilled in the art.

Claims

1. A flexible automated machining unit for combined turning and milling production, characterized in that: It includes a first roughing CNC lathe (1), a second roughing CNC lathe (2), a first finishing CNC lathe (3), a second finishing CNC lathe (4), a CNC milling machine (5), a six-axis articulated robot (6), a stepped material car, a workpiece buffer rack (9), and a control system; The first roughing CNC lathe (1) and the second roughing CNC lathe (2) are arranged back to back, the first finishing CNC lathe (3) and the second finishing CNC lathe (4) are arranged back to back, and the first roughing CNC lathe (1) and the first finishing CNC lathe (3) are arranged side by side, the second roughing CNC lathe (2) and the second finishing CNC lathe (4) are arranged side by side, and the CNC milling machine (5) is located on the side of the first finishing CNC lathe (3) and the second finishing CNC lathe (4) away from the first roughing CNC lathe (1) and the second roughing CNC lathe (2), so that the first roughing CNC lathe (1), the second roughing CNC lathe (2), the first finishing CNC lathe (3), the second finishing CNC lathe (4) and the CNC milling machine (5) form a U-shaped layout; A six-axis articulated robot (6) is arranged in the middle of the U-shaped layout, and a stepped material cart is arranged at the opening of the U-shaped layout; The workpiece buffer rack is used to hold materials, including finish-turned blanks and rough-turned blanks; the six-axis articulated robot (6) is used for the movement, loading and unloading of materials between the first rough-turning CNC lathe (1), the second rough-turning CNC lathe (2), the first finish-turning CNC lathe (3), the second finish-turning CNC lathe (4), the CNC milling machine (5), the stepped material carriage and the workpiece buffer rack; the first rough-turning CNC lathe (1) and the second rough-turning CNC lathe (2) are used to rough-machine the end face, outer contour and inner cavity contour of the rough-turned blank to obtain the rough-turned part, and the rough-turned part is heat-treated to obtain the finish-turned blank; the first finish-turning CNC lathe (3) and the second finish-turning CNC lathe (4) perform precision-dimensional finish-machine the end face, outer contour and inner cavity contour of the finish-turned blank to obtain the finish-turned part, and the CNC milling machine (5) performs precision milling on the finish-turned part to obtain the product; the control system is used to control the six-axis articulated robot (6) to move the materials for processing within the U-shaped layout; The six-axis articulated robot (6) is connected to the ground via a seventh-axis moving guide rail, which is used to drive the six-axis articulated robot (6) to move back and forth along the direction from the stepped material cart to the CNC milling machine (5); The stepped material car includes a roughing stepped material car (7) and a finishing stepped material car (8). The roughing stepped material car (7) and the finishing stepped material car (8) are arranged side by side at the opening of the U-shaped layout. The roughing stepped material car (7) is used to place the roughing blanks of the upper and lower end caps, or the roughing blanks of the front and rear end caps. The finishing stepped material car (8) is used to place the finishing blanks of the upper and lower end caps, or the finishing blanks of the front and rear end caps. The upper surface of the stepped material cart is set with multiple steps of increasing height, and the upper surface of each step is set with storage positions for storing materials; Five workpiece buffer racks (9) are provided: one workpiece buffer rack (9) is arranged on the side of the first roughing CNC lathe (1) facing the second roughing CNC lathe (2), one workpiece buffer rack (9) is arranged on the side of the second roughing CNC lathe (2) facing the first roughing CNC lathe (1), one workpiece buffer rack (9) is arranged on the side of the first finishing CNC lathe (3) facing the second finishing CNC lathe (4), one workpiece buffer rack (9) is arranged on the side of the second finishing CNC lathe (4) facing the first finishing CNC lathe (3), and one workpiece buffer rack (9) is arranged on the side of the CNC milling machine (5) facing the six-axis articulated robot (6); each workpiece buffer rack has two buffer stations and one column; The first roughing CNC lathe (1), the second roughing CNC lathe (2), the first finishing CNC lathe (3), and the second finishing CNC lathe (4) are equipped with automatic opening and closing doors on their backs for transferring and exchanging materials from the back; the CNC milling machine (5) has an automatic opening and closing door on the side facing the six-axis articulated robot (6) for transferring and exchanging materials from the side. For the upper and lower head precision-machined blanks, the upper head precision-machined blank has an internal thread at the large end, and the lower head precision-machined blank has an external thread at the large end. In the first precision-machined CNC lathe (3) and the second precision-machined CNC lathe (4), one is equipped with an external clamping fixture, and the other is equipped with an internal support fixture. For the precision machining blanks of the front and rear heads, the large and small ends of the precision machining blank of the front head have internal threads, the large end of the precision machining blank of the rear head has internal threads, and the outer surface of the small end has a convex ring. Both the first precision machining CNC lathe (3) and the second precision machining CNC lathe (4) are equipped with external clamping fixtures.

2. A flexible automated machining method for combined turning and milling production, characterized in that: Processing using the flexible automated machining unit for milling and turning production as described in claim 1 includes: S1: The six-axis articulated robot (6) moves the roughing blank from the roughing step car (7) to the first roughing CNC lathe (1) or the second roughing CNC lathe (2) for roughing to obtain the roughing part. The six-axis articulated robot (6) moves the roughing part to the roughing step car (7). S2: The six-axis articulated robot (6) moves the precision-turned blank from the precision-turned stepped material cart (8) to the first precision-turned CNC lathe (3) and / or the second precision-turned CNC lathe (4) for precision machining to obtain precision-turned parts. Then, the six-axis articulated robot (6) moves the precision-turned parts to the CNC milling machine (5) for precision milling to obtain the product. The six-axis articulated robot (6) moves the product back to the precision-turned stepped material cart (8). Step S1 includes: a six-axis articulated robot (6) transports the roughing blank from the roughing step car (7) to the buffer station of the workpiece buffer rack (9); the six-axis articulated robot (6) then loads the roughing blank from the buffer station of the workpiece buffer rack (9) into a machining station of the first roughing CNC lathe (1) or the second roughing CNC lathe (2) to machine the end face and outer contour to obtain an intermediate roughing part; the six-axis articulated robot (6) moves the intermediate roughing part to the column of the workpiece buffer rack (9) for flipping; the six-axis articulated robot (6) then loads the flipped intermediate roughing part into another machining station of the first roughing CNC lathe (1) or the second roughing CNC lathe (2) to machine the end face and inner cavity contour to obtain a roughing part; the six-axis articulated robot (6) transports the roughing part to the buffer station of the workpiece buffer rack (9); and finally transports the roughing part back to the roughing step car (7). If the upper and lower end caps are precision-machined blanks, in step S2, the precision-machined blank of the upper end cap is loaded into a precision-machined CNC lathe with an internal support fixture. The precision-machined CNC lathe is either a first precision-machined CNC lathe (3) or a second precision-machined CNC lathe (4). The end face and outer contour of the precision-machined part are machined to obtain an intermediate precision-machined part. The six-axis articulated robot (6) transports the intermediate precision-machined part to the column of the workpiece buffer rack (9) for flipping. The six-axis articulated robot (6) then loads the flipped intermediate precision-machined part into a precision-machined CNC lathe with an external clamping fixture. The end face, inner cavity contour and internal thread of the precision-machined part are machined to obtain a precision-machined part. The CNC milling machine (5) performs precision milling on the precision-machined part to obtain the product. The lower end head precision-machined blank is transported to the column of the workpiece buffer rack (9) for flipping. The six-axis articulated robot (6) then loads the flipped intermediate precision-machined part into a precision-machined CNC lathe with an external clamping fixture, and processes the end face and inner cavity contour with precise dimensions to obtain the intermediate precision-machined part. The six-axis articulated robot (6) transports the intermediate precision-machined part to the column of the workpiece buffer rack (9) for flipping. The six-axis articulated robot (6) then loads the flipped intermediate precision-machined part into a precision-machined CNC lathe with an internal support fixture, and processes the outer contour and external thread with precise dimensions to obtain the precision-machined part. The CNC milling machine (5) performs precision milling on the precision-machined part to obtain the product. If the front end and rear end are precision-machined blanks, in step S2, the precision-machined blank of the front end is loaded into a precision-machined CNC lathe with an external clamping fixture, and the end face, outer contour, inner cavity contour and internal thread of the large end position with precise dimensions are machined. After the six-axis articulated robot (6) flips the precision-machined blank of the front end, it is fed into the same precision-machined CNC lathe to machine the end face, outer contour, inner cavity contour and internal thread of the small end position with precise dimensions, and the precision-machined part is obtained. The CNC milling machine (5) performs precision milling on the precision-machined part to obtain the product. The rear end blank is loaded into a precision CNC lathe with an external clamping fixture. The large end face, outer contour, inner cavity contour and internal thread of precise dimensions are machined. The six-axis articulated robot (6) flips the front end blank and feeds it into the same precision CNC lathe. The small end face, outer contour and inner cavity contour of precise dimensions are machined to obtain the precision machined part. The CNC milling machine (5) performs precision milling on the precision machined part to obtain the product. The machine tool executes the automatic processing main program, the machine tool starts to execute the station cleaning subroutine, and then sends a signal to the PLC through the machine tool's custom M command to call the robot to unload the material; The robot's automatic operation program is started, and the robot begins to respond to the call signal to load materials into the machine tool; first, it grabs the billet from the material cart to the workpiece buffer rack, and then loads it into the machine tool from the workpiece buffer rack; after the buffer position is cleared, the robot automatically replenishes materials by grabbing the billet from the material cart and placing it into the buffer position; Inside the machine tool, auxiliary positioning blocks are used to perform secondary positioning of the clamped blanks to ensure clamping accuracy. After the first roughing CNC lathe and the second roughing CNC lathe have finished processing at the first station, the robot grabs the material and flips the part on the workpiece buffer rack column before sending it back into the machine tool for processing. After processing, the robot picks up the material, places it in the workpiece buffer rack where semi-finished products are stored, and then puts it back into the material cart.

Images