A processing method for an outer hanging piece of a combustion chamber shell

Abstract

The present application is a kind of processing technology method of combustion chamber shell outer hanging piece, belonging to the field of precision machining technology. The process method adopts full-automatic processing mode, uses turning and milling combined processing technology method to replace the traditional mechanical processing technology of outer hanging piece. The consistency of mechanical processing size tolerance of combustion chamber shell outer hanging piece is guaranteed, the symmetry and perpendicularity of thread hole are guaranteed, and the qualified rate of outer hanging piece reaches 100% after welding, heat treatment and tap cleaning of the processed outer hanging piece and combustion chamber shell. It is a kind of fast and efficient outer hanging piece processing technology method. The problems of long mechanical processing procedure, low processing efficiency and difficult to guarantee processing precision of existing outer hanging piece are solved.

Description

Technical Field

[0001] The present invention belongs to the technical field of precision machining, and in particular relates to a method for machining a combustion chamber shell external component. Background Art

[0002] External plug-ins are primarily used in military solid rocket motors. They are welded to the outer wall of the combustion chamber casing and are used to mount components such as cable covers. The external plug-in has threaded holes that allow screw connections to be made to install components such as cable covers.

[0003] External components are typically made of metal, typically 20CrMnTi, 30CrMnSiA, or D406A. They are often small, rectangular blocks with high precision requirements. Their overall dimensions are no larger than 20mm x 20mm, with a tolerance of approximately 0.10mm. They are 3mm to 8mm thick, with a tolerance of 0 to 0.05mm. They feature a centrally located threaded hole, ranging from M3mm to M8mm. The threaded hole has a 7H precision, and its symmetry with the external component is no greater than 0.1mm, and its perpendicularity to the end face is no greater than 0.05mm. These geometric tolerances are difficult to maintain during machining. Figure 1 This is a schematic diagram of an external component of an engine combustion chamber casing. The required dimensional tolerance of this external component is 0.10mm.

[0004] The external parts must first be machined, then welded to the combustion chamber shell. After being processed together with the combustion chamber shell, they must undergo annealing, quenching, and tempering heat treatment processes, and then the threads must be cleaned with corresponding thread taps to meet the thread accuracy requirements.

[0005] The existing external parts machining method has a lengthy process and the machining accuracy is difficult to guarantee. The raw materials are generally φ180mm~φ200mm bars, which need to be formed through processes such as turning, grinding, wire cutting, CNC milling, and clamping. The machining process is as follows Figure 2 As shown. This process has the following main defects:

[0006] 1. Grinding and wire cutting processes are time-consuming and labor-intensive. Bench work is manual work, and the number of external parts to be processed is large, so the labor intensity is high.

[0007] 2. Each process has many turnover times, occupies a lot of equipment resources, and has low processing efficiency.

[0008] 3. The processing process of plug-in parts is complicated and lengthy, which is not suitable for batch production.

[0009] 4. Low production efficiency. The processing of the plug-in requires 5 steps and 5 clampings to complete the processing of the entire workpiece. Each product takes 20 minutes, which seriously restricts production.

[0010] 5. The processing accuracy is difficult to guarantee, and the processing quality consistency is poor. It is easy to have poor symmetry of the threaded holes and the perpendicularity between the threaded holes and the end faces does not meet the requirements. There will be deviations in the position accuracy of the threaded holes after welding and heat treatment. In addition, since the external parts are deformed after welding and heat treatment, when the thread accuracy of the external parts is processed according to the 7H precision required by the drawings, the threaded hole accuracy will often be out of tolerance after the tap cleaning process due to deformation. This will result in the screws being unable to be assembled due to the out-of-tolerance position accuracy of the threaded holes when assembling the cable protection cover, or the thread strength is reduced due to the out-of-tolerance threaded hole accuracy. In severe cases, the entire combustion chamber shell will be scrapped, causing great waste and poor economic efficiency. Summary of the Invention

[0011] Technical problem to be solved: In order to avoid the shortcomings of the existing technology, the present invention provides a combustion chamber shell external plug-in processing method, which adopts automated processing technology to replace the traditional processing technology, and solves the problems of lengthy machining procedures, low machining efficiency and difficulty in ensuring machining accuracy of existing external plug-in parts.

[0012] The technical solution of the present invention is: a method for processing a combustion chamber shell external component, comprising the following steps:

[0013] Step 1: Prepare blanking: Take a bar with a diameter not exceeding φ30mm and cut it into blanks with a length of 800mm to 1000mm;

[0014] Step 2, automatic loading: the blanks cut in step 1 are delivered to the CNC machine tool through the automatic loading device;

[0015] The automatic loading device includes: a storage mechanism, a propulsion mechanism, and a guide tube; the storage mechanism is used to store the blanks discharged in step 1, and a first rotating mechanism is provided at the bottom of the storage mechanism for transferring the blanks into the propulsion mechanism; the propulsion mechanism is located below the storage mechanism and is used to push the blanks horizontally into the guide tube and to push them to the hydraulic chuck servo device of the CNC machine tool; the guide tube connects the propulsion mechanism and the hydraulic chuck servo device of the CNC machine tool and is used for guiding the blanks during the pushing process;

[0016] Step 3: Automatic processing: Using a turning and milling composite processing method, a single external component is clamped and processed into shape in one step;

[0017] Step 3.1: The hydraulic chuck of the CNC machine tool clamps a blank conveyed by the guide tube in step 2;

[0018] Step 3.2, turning the outer end face of the blank; turning the outer circle of the blank, with the axial turning length being the first length; turning the threaded bottom hole, with the axial turning length also being the first length; turning the countersink at the outer end of the threaded bottom hole to the drawing size; the first length being greater than the thickness of the external component;

[0019] Step 3.3, turning a relief groove in the threaded bottom hole processed in step 3.2, wherein the distance between the outer wall of the relief groove and the outer end surface of the processed blank is the thickness dimension of the external component;

[0020] Step 3.4: Turn the internal thread in the thread bottom hole where the undercut groove was machined in step 3.3. The thread accuracy is 2 levels higher than the accuracy required by the external component thread hole drawing.

[0021] Step 3.5: After the internal thread processing in step 3.4 is completed, a clearance groove is turned on the outer circle of the turned blank. The clearance groove is used to cut the processed external component from the blank. The distance between the outer wall of the clearance groove and the outer end face of the processed blank is the thickness of the external component. After completing step 3.5, a rough blank of the external component is obtained;

[0022] Step 3.6: Mill the rough shape of the external plug-in to make its shape meet the requirements of the external plug-in drawing;

[0023] After step 3.7 and step 3.6 are completed, the outer part is cut off at the recess by a cutting knife to obtain a finished product;

[0024] Step 4: Automatic blanking: The finished plug-in obtained in step 3.7 is transferred into the finished product box through the automatic blanking mechanism;

[0025] Step 5: Repeat steps 3 and 4 until one blank is processed, automatically load the blank to the CNC machine tool through step 2, and repeat steps 3 and 4 to process another blank; repeat steps 2 and 4 until the blanks in the storage mechanism are processed.

[0026] A further technical solution of the present invention is that: the hydraulic chuck is provided with an automatic blank advancing device for advancing the blank after blanking of an external part is completed.

[0027] A further technical solution of the present invention is: a maximum of 15 blanks can be placed in the storage mechanism at a time; the first rotating mechanism at the bottom of the storage mechanism is provided with a shifting tooth, and the rotating mechanism is driven to rotate by the first motor, driving the shifting tooth to drop a blank from the discharge port at the bottom of the storage mechanism into the propulsion mechanism.

[0028] A further technical solution of the present invention is: the propulsion mechanism includes a pneumatic propulsion device and a push rod; the pneumatic propulsion device is driven to move up and down by a second motor, and the blanking area of ​​the pneumatic propulsion device is provided with two workstations, one is a waiting position and the other is a working position; the waiting position is located below the discharge port of the storage mechanism and is used to receive the blank; the working position is horizontally aligned with the guide tube, and when the blanking area is in the working position, the blank is pushed into the guide tube by the pneumatic propulsion of an external pneumatic system; the push rod is located directly below the working position of the blanking area, and the push rod is driven to move up and down by a third motor; when the blanking area returns to its waiting position, the push rod moves up to the working position of the blanking area, and one end of the push rod is pushed by the external pneumatic system to push the blank in the guide tube into the hydraulic chuck servo device of the CNC machine tool.

[0029] A further technical solution of the present invention is that the pushing displacement of the push rod on the blank can be adjusted according to blanks of different lengths.

[0030] A further technical solution of the present invention is: a displacement sensor is provided in the guide tube near one end of the hydraulic chuck, which is used to sense the displacement of the blank being processed; the displacement sensor is electrically connected to the control system of the CNC machine tool, and the control system receives the signal of the displacement sensor to determine whether the next blank should be delivered to the CNC machine tool by the automatic loading device.

[0031] A further technical solution of the present invention is: the automatic blanking mechanism includes a material receiving device and a crawler conveyor device, the material receiving device is located directly below the workpiece processed by the CNC machine tool, and is used to receive the finished plug-in parts cut off and blanked in step 3.7 and transfer them to the crawler conveyor device; the crawler conveyor device is located on one side of the material receiving device, and is used to convey the finished plug-in parts into the finished product box through the crawler belt.

[0032] A further technical solution of the present invention is: the material receiving device includes a second rotating mechanism and a material receiving tray, the material receiving tray is located directly below the workpiece processed by the CNC machine tool, and is used to receive the finished external parts that have been processed; the material receiving tray is fixedly connected to the second rotating mechanism, and the material receiving tray is driven to flip by the second rotating mechanism, so as to deliver the finished external parts to the crawler of the crawler conveyor device; the second rotating mechanism is driven to rotate by a fourth motor.

[0033] A further technical solution of the present invention is: gravity sensors are provided on the receiving tray and the crawler belt to sense whether there are finished plug-in parts. The sensors are electrically connected to the control system of the CNC machine tool to transmit the sensing signal to the control system, and the second rotating mechanism and the crawler conveyor device are controlled by the control system.

[0034] A further technical solution of the present invention is as follows: the bar material includes a solid bar material and a hollow tube material, and the hollow diameter of the hollow tube material is smaller than the diameter of the threaded bottom hole of the external component to be processed.

[0035] Beneficial effects

[0036] The beneficial effects of the present invention are as follows: the present invention provides a method for processing the external plug-in of the combustion chamber shell, which has high processing precision and good consistency in the quality of the processed products. By adopting a fully automatic processing method and using a turning and milling composite processing method, the consistency of the external plug-in processing dimensional tolerance is guaranteed, so that the position accuracy such as the symmetry and verticality of the threaded hole is guaranteed. After the processed external plug-in and the combustion chamber shell are welded and heat treated, and the threaded hole is cleaned with a tap, the qualified rate of the external plug-in reaches 100%, ensuring the installation of the protective cover. It is a fast and efficient external plug-in processing method. This process method solves the problems of the existing external plug-in processing method, such as lengthy procedures, many control points, cumbersome process, poor processing quality consistency, and difficulty in ensuring processing precision.

[0037] The method of the present invention has high production efficiency. Taking a single blank with a length of 1000mm and a thickness of 3.5mm as an example, the processing method of the present invention can continuously and uninterruptedly process at least 100 external parts from a single blank. According to the automatic loading device, 15 blanks are fully loaded at a time. The processing time of each external part is 5 minutes, and each blank takes 500 minutes. A single full loading can continuously process for 125 hours, a total of 5.2 days. That is, a single loading can continuously process for 24 hours without interruption for 5.2 days, processing 1500 external parts. If the existing process method is used, it takes 20.8 days to process 1500 external parts. After the improvement of this method, the time is shortened from 20.8 days to 5.2 days, and the production efficiency is improved by more than 300%.

[0038] The method of the present invention improves the accuracy level of the threaded holes during mechanical processing of the external parts, adopts the principle of deformation tolerance, and ensures the final accuracy requirements of the threaded holes after the external parts are welded and heat treated, eliminating the quality risks of the external parts in the combustion chamber shell state. The quality risks of the threaded holes are eliminated from the process method, and the processability is good. In addition, by changing the thread processing direction of the traditional processing method, the thread is turned from one end of the countersink of the threaded hole, which significantly improves the final accuracy of the threaded hole compared to the existing method of tapping from the back of the countersink. According to process verification, the final product qualification rate is only about 70% when the thread tapping starts from the non-counterbore surface. By turning the thread from the countersink end through the method of the present invention, the thread accuracy level is improved by two levels, which ensures a 100% qualification rate of the subsequent external parts for the final 7H precision quality.

[0039] The method of the present invention has low energy consumption. For a single external component, the method can be clamped and positioned once, and the process characteristics of turning, milling, drilling, tapping and chamfering can be completed through turning and milling composite processing, thereby avoiding errors caused by repeated clamping and positioning, ensuring product precision and quality consistency, and reducing equipment resource occupation, eliminating processes such as grinding and wire cutting that are energy-intensive and highly polluting, and eliminating processes such as manual benchwork that are labor-intensive and have poor quality consistency, thereby realizing green processing, reducing processing costs, and reducing equipment energy consumption.

[0040] The method of the present invention boasts a high level of automation. Through an automatic loading device, automated processing methods, and automated unloading mechanisms, it achieves full process automation, reducing operator labor intensity while also avoiding the impact of human factors on product quality. Automating the entire production process allows for unmanned loading and unloading of external components within a 12-hour feeding cycle. This increased level of production automation can effectively improve product consistency and production efficiency, overcome bottlenecks in quality instability, and reduce the dispersion of product structure and performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 This is a schematic diagram of the external parts of a combustion chamber casing of an engine;

[0042] Figure 2 This is the process flow chart for the existing plug-in processing;

[0043] Figure 3 This is a flowchart of the processing process of the external plug-in according to the present invention;

[0044] Figure 4 Schematic diagram of turning the outer circle, threaded bottom hole and countersink in an embodiment of the present invention;

[0045] Figure 5 This is a schematic diagram of a car backing groove in an embodiment of the present invention;

[0046] Figure 6 Schematic diagram of threaded holes in an embodiment of the present invention;

[0047] Figure 7 Schematic diagram of a vehicle retreat groove in an embodiment of the present invention;

[0048] Figure 8 This is a schematic diagram of the milling shape in an embodiment of the present invention;

[0049] Figure 9 This is a schematic diagram of a completed plug-in product according to an embodiment of the present invention;

[0050] Figure 10 This is a schematic structural diagram of an automatic loading device in an embodiment of the present invention;

[0051] Figure 11This is a structural diagram of an automatic blanking mechanism in an embodiment of the present invention;

[0052] Figure 12 A solid diagram of an external component processed according to an embodiment of the present invention installed on an engine combustion chamber casing.

[0053] Explanation of the accompanying symbols: 1. Blank, 11. Outer end face, 12. Outer circle, 13. Threaded bottom hole, 131. Threaded hole, 14. Countersunk hole, 15. Back-off groove, 16. Makeshift groove, 2. Automatic loading device, 21. Storage mechanism, 211. First rotating mechanism, 22. Propelling mechanism, 221. Blanking area of ​​pneumatic propulsion device, 222. Pushing rod, 23. Guide tube, 24. External pneumatic system, 3. Hydraulic chuck, 4. Finished external component, 5. Automatic blanking mechanism, 51. Crawler conveyor, 52. Second rotating mechanism, 53. Receiving tray, 54. Finished product box. DETAILED DESCRIPTION

[0054] The embodiments described below with reference to the accompanying drawings are exemplary and are intended to explain the present invention, but should not be construed as limiting the present invention.

[0055] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0056] This embodiment proposes a combustion chamber shell plug-in processing method, which is mainly used to solve the defects of the existing plug-in processing process, such as lengthy process steps, low processing precision, poor quality consistency, and low precision of threaded holes after welding. In this embodiment, an automated processing method is used, and the specific process flow is as follows: Figure 3 As shown, it replaces the traditional process of existing external parts, improves processing efficiency, and ensures processing accuracy. By welding the external parts processed by the present invention to the combustion chamber shell, after subsequent process treatment, the qualified rate of the external parts reaches 100% after testing, which fully meets the production requirements.

[0057] This embodiment uses processing Figure 1 Taking the external plug-in shown as an example, the processing method of the present invention is described. Figure 1 The material of the external parts shown is: D406A, annealed, hardness: HRC18~22, dimensions: Thickness 3.5mm, countersunk hole φ6mm, threaded hole M4-7H, threaded hole depth 3mm, side wall transition radius 4-R2, top surface and side wall transition radius 4-R1.

[0058] The processing method includes the following steps: the CNC machine tool selects the turning and milling compound processing unit CK-46.

[0059] Step 1: Prepare the blanks: Select a φ18mm diameter bar stock and cut it into 800mm long blanks (1), cutting a total of 15 bars. The bar stock can be solid or hollow. When choosing hollow tubing, its hollow diameter should be smaller than the diameter of the threaded bottom hole of the external component to be machined. In this example, a φ18mm solid bar stock is selected.

[0060] Step 2, automatic loading: The blank 1 cut in step 1 is delivered to the CNC machine tool through the automatic loading device 2. Figure 10 As shown, the automatic loading device 2 comprises a storage mechanism 21, a propulsion mechanism 22, and a guide tube 23. The storage mechanism 21 is used to store the blanks 1 removed in step 1. A first rotating mechanism 211 is located at the bottom of the storage mechanism 21 to push the blanks 1 into the propulsion mechanism 22. The propulsion mechanism 22, located below the storage mechanism 21, is used to push the blanks 1 horizontally into the guide tube 23 and onto the hydraulic chuck 3 servo mechanism of the machine tool. The guide tube 23 is a hollow tube that connects the propulsion mechanism 22 to the hydraulic chuck 3 servo mechanism of the CNC machine tool, guiding the pushing process of the blanks 1.

[0061] For details, see Figure 10 The storage mechanism 21 is manually loaded, and the 15 blanks 1 discharged in step 1 are stored in the storage mechanism 21. A desired number of blanks 1 can also be placed according to production needs, with a maximum of 15 blanks. The first rotating mechanism 211 at the bottom of the storage mechanism 21 is provided with a shifting tooth, which is fixedly connected to the first rotating mechanism 211. The rotating mechanism 211 is driven by the first motor to rotate, thereby driving the shifting tooth to shift a blank 1 from the discharge port at the bottom of the storage mechanism 21 into the pushing mechanism 22.

[0062] The top of the propulsion mechanism 22 is connected to the discharge port at the bottom of the storage mechanism 21. The propulsion mechanism 22 includes a pneumatic propulsion device and a push rod 222. The pneumatic propulsion device is used to push the blank 1 horizontally into the guide tube 23. Driven by a second motor, the pneumatic propulsion device can be moved up and down within the propulsion mechanism 22, forming two workstations in the blanking area 221 of the pneumatic propulsion device: a waiting position and a working position. The waiting position of the blanking area 221 of the pneumatic propulsion device is located directly below the discharge port of the storage mechanism 21 and is used to receive the blank 1. The working position of the blanking area 221 of the pneumatic propulsion device is horizontally aligned with the guide tube 23. When the blanking area 221 is in the working position, the blank 1 is pushed horizontally into the guide tube 23 through pneumatic propulsion from an external pneumatic system 24. The waiting position of the push rod 222 is located directly below the working position of the blanking area 221. The push rod 222 is driven up and down by a third motor. When the blanking area 221 returns to its waiting position, the push rod 222 moves up to the working position of the blanking area 221, that is, the working position of the push rod 222. The left end of the push rod 222 is pushed by the external pneumatic system 24 to push the blank 1 in the guide tube 23 into the hydraulic chuck servo device of the CNC machine tool. The external pneumatic system 24 can provide pneumatic thrust for the pneumatic propulsion device and the push rod 222, and the external pneumatic system 24 is controlled by the control system of the CNC machine tool. A track is provided at the working position of the blanking area 221 inside the propulsion mechanism 22 to facilitate the horizontal propulsion of the pneumatic propulsion device along the track. At the same time, the propulsion of the push rod 222 is controlled by the external pneumatic system 24, and its propulsion displacement of the blank 1 can be adjusted according to the different lengths of the blank 1.

[0063] Step 3: Automatic processing: Using a turning and milling composite processing method, a single external component is clamped and processed into shape in one step.

[0064] Step 3.1: The hydraulic chuck 3 of the CNC machine tool clamps a blank 1 conveyed by the guide tube 23 in step 2. After the clamping preparation is completed, the CNC machine tool starts processing according to the processing program settings.

[0065] Step 3.2, refer to Figure 4 In this step, the outer end face 11 of the blank 1 is first turned to ensure the flatness and surface finish requirements. Then the outer circle 12 of the blank 1 is turned to make the outer circle diameter φ17mm and the axial length of the turning is 10mm. When turning the outer circle, the processing amount reserved for subsequent milling is considered, and the processing amount reserved for the axial length of the turning is considered for subsequent cutting. Then the threaded bottom hole 13 is turned, and the axial turning length of the threaded bottom hole 13 is 10mm. Finally, the countersink 14 at the outer end of the threaded bottom hole 13 is turned. The diameter of the countersink 14 is φ6mm and the turning depth is φ6mm.

[0066] Step 3.3, see Figure 5In this step, a relief groove 15 is machined in the threaded bottom hole 13 machined in step 3.2. The dimensions of the relief groove 15 are 3mm x φ5mm, i.e., the width of the relief groove 15 is 3mm and the major diameter is φ5mm. The distance from the inner side wall of the relief groove 15 to the outer end face at this time is ensured to be 6.5mm.

[0067] Step 3.4, refer to Figure 6 In this step, after the undercut groove 15 is machined in step 3.3, an internal thread of M4 is turned in the thread bottom hole 13, with a thread accuracy grade of 5H, to form a thread hole 131 with a thread grade higher than 7H required by the drawing.

[0068] Step 3.5, see Figure 7 After step 3.4, a clearance groove 16 is machined on the outer diameter of the blank 1, which has been turned to φ17mm. The dimensions of the clearance groove 16 are 3mm x φ8mm, meaning the width of the clearance groove 16 is 3mm and the minimum diameter is φ8mm. The clearance groove 16 is the same width as the undercut 15 and is coplanar. The outer wall of the clearance groove 16 is 3.5mm away from the outer end face at this point. The clearance groove 16 is used to cut off the subsequently processed external component from the blank 1. After step 3.5, a rough blank of the external component is obtained.

[0069] Step 3.6, see Figure 8 , milling the rough shape of the external parts, including milling the sides and fillets, to ensure the size: 4-R1, 4-R2, 3.5mm.

[0070] Step 3.7, see Figure 8 After the milling of the outer shape in step 3.6, use a cutting tool to cut off the clearance groove 16 to obtain Figure 9 The finished product 4 of the external plug-in is shown.

[0071] Step 4: Automatic blanking: the finished plug-in product 4 obtained in step 3.7 is delivered to the finished product box 54 through the automatic blanking mechanism 5.

[0072] See Figure 11 In this embodiment, an automatic blanking mechanism 5 is provided. The automatic blanking mechanism 5 includes a second rotating mechanism 52, a receiving tray 53 and a crawler conveyor 51. The receiving tray 53 is located directly below the workpiece processed by the CNC machine tool and is used to receive the finished plug-in parts 4 processed in step 3.7. The receiving tray 53 is fixedly connected to the second rotating mechanism 52. The receiving tray 53 is driven by the second rotating mechanism 52 to flip over and is used to deliver the finished plug-in parts 4 in the receiving tray 53 to the crawler of the crawler conveyor 51. The second rotating mechanism 52 is driven to rotate by a fourth motor. The crawler conveyor 51 is located on one side of the second rotating mechanism 52 and is used to automatically transport the finished plug-in parts 4 to the finished product box 54 via the crawler. The crawler conveyor 51 is controlled by the control system of the CNC machine tool.

[0073] In order to save power consumption, this embodiment is provided with gravity sensors on the receiving tray 53 and the crawler belt to sense whether any external finished product 4 falls on it. The sensor is electrically connected to the control system of the CNC machine tool and transmits the sensing signal to the control system, which controls the operation of the second rotating mechanism 52 and the crawler conveyor through the control system.

[0074] Step 5: Repeat steps 3 and 4 until one blank 1 is processed. In this embodiment, the hydraulic chuck 3 is equipped with an automatic blank advancing device to advance the blank 1 after the blank is blanked. After a finished external component 4 is blanked, the machine tool control system controls the hydraulic chuck 3 to release the blank 1 and controls the automatic advancing device to advance the blank 1 a certain distance. Once in position, the hydraulic chuck 3 continues to clamp the blank 1 to proceed with the processing of the next external component. In this embodiment, one blank 1 can be processed into 110 finished external components 4.

[0075] After processing one blank 1, the CNC machine's control system controls the automatic loading mechanism 2 to automatically feed the blank to the machine, and then repeats steps 3 and 4 to process another blank 1. Specifically, a displacement sensor is located within the guide tube 23, near one end of the hydraulic chuck 3, to sense the displacement of the blank 1 being processed. This displacement sensor is electrically connected to the CNC machine's control system. When the sensor detects that a blank 1 is no longer within its detection range, the control system receives a signal from the sensor and controls the automatic loading mechanism 2 to deliver the next blank 1 to the machine. Steps 2 and 4 are repeated until all 15 blanks 1 in the storage mechanism 21 have been processed, and then the cycle continues.

[0076] It should be noted that the four drive motors in this embodiment are also controlled by the control system of the CNC machine tool.

[0077] See Figure 12 The external part processed by the processing method of this embodiment is welded to the combustion chamber cylinder by manual argon arc welding. The weld seam meets the requirements of QJ175-93 Grade II weld seam after magnetic particle inspection. After the D406A material is annealed, quenched and tempered, the M4-7H threaded hole of the external part is cleaned with an M4-6H tap and a thread plug gauge is used. Inspection, all passed.

[0078] Although the embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are illustrative and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention without departing from the principles and purpose of the present invention.

Claims

1. A method for processing a combustion chamber shell external component, characterized in that: The following steps are involved: Step 1: Prepare blanking: Take a bar with a diameter not exceeding φ30mm and cut it into blanks with a length of 800mm to 1000mm; Step 2, automatic loading: the blanks cut in step 1 are delivered to the CNC machine tool through the automatic loading device; The automatic loading device includes: a storage mechanism, a propulsion mechanism, and a guide tube; the storage mechanism is used to store the blanks discharged in step 1, and a first rotating mechanism is provided at the bottom of the storage mechanism for transferring the blanks into the propulsion mechanism; the propulsion mechanism is located below the storage mechanism and is used to push the blanks horizontally into the guide tube and to push them to the hydraulic chuck servo device of the CNC machine tool; the guide tube connects the propulsion mechanism and the hydraulic chuck servo device of the CNC machine tool and is used for guiding the blanks during the pushing process; Step 3: Automatic processing: Using a turning and milling composite processing method, a single external component is clamped and processed into shape in one step; Step 3.1: The hydraulic chuck of the CNC machine tool clamps a blank conveyed by the guide tube in step 2; Step 3.2, turning the outer end face of the blank; turning the outer circle of the blank, with the axial turning length being the first length; turning the threaded bottom hole, with the axial turning length also being the first length; turning the countersink at the outer end of the threaded bottom hole to the drawing size; the first length being greater than the thickness of the external component; Step 3.3, turning a relief groove in the threaded bottom hole processed in step 3.2, wherein the distance between the outer wall of the relief groove and the outer end surface of the blank processed in step 3.2 is the thickness dimension of the external component; Step 3.4: Turn the internal thread in the thread bottom hole where the undercut groove was machined in step 3.

3. The thread accuracy is 2 levels higher than the accuracy required by the external component thread hole drawing. After steps 3.5 and 3.4 are completed, a clearance groove is turned on the outer circumference of the blank after turning. The clearance groove is used to cut the processed external component from the blank. The distance between the outer wall of the clearance groove and the outer end surface of the blank after step 3.2 is the thickness of the external component. After step 3.5 is completed, a rough blank of the external component is obtained; Step 3.6: Mill the rough shape of the external plug-in to make its shape meet the requirements of the external plug-in drawing; After step 3.7 and step 3.6 are completed, the outer part is cut off at the recess by a cutting knife to obtain a finished product; Step 4: Automatic blanking: The finished plug-in obtained in step 3.7 is transferred into the finished product box through the automatic blanking mechanism; Step 5: Repeat steps 3 and 4 until one blank is processed, automatically load the blank to the CNC machine tool through step 2, and repeat steps 3 and 4 to process another blank; repeat steps 2 and 4 until the blanks in the storage mechanism are processed.

2. The method according to claim 1, wherein: The hydraulic chuck is provided with an automatic blank advancing device for advancing the blank after blanking of an external part is completed.

3. The method according to claim 1, wherein: The storage mechanism can hold up to 15 blanks at a time. The first rotating mechanism at the bottom of the storage mechanism is provided with shifting teeth, which are driven by the first motor to rotate the rotating mechanism, thereby driving the shifting teeth to drop a blank from the discharge port at the bottom of the storage mechanism into the propulsion mechanism.

4. The method according to claim 3, wherein: The propulsion mechanism includes a pneumatic propulsion device and a push rod; the pneumatic propulsion device is driven to move up and down by a second motor, and the blanking area of ​​the pneumatic propulsion device is provided with two workstations, one is a waiting position and the other is a working position; the waiting position is located directly below the discharge port of the storage mechanism and is used to receive the blank; the working position is horizontally aligned with the guide tube, and when the blanking area is in the working position, the blank is pushed into the guide tube by the pneumatic propulsion of an external pneumatic system; the push rod is located directly below the working position of the blanking area, and the push rod is driven to move up and down by a third motor; when the blanking area returns to its waiting position, the push rod moves up to the working position of the blanking area, and one end of the push rod is pushed by the external pneumatic system to push the blank in the guide tube into the hydraulic chuck servo device of the CNC machine tool.

5. The method according to claim 4, characterized in that: The pushing displacement of the push rod on the blank can be adjusted according to blanks of different lengths.

6. The method according to claim 1, wherein: A displacement sensor is provided in the guide tube near one end of the hydraulic chuck for sensing the displacement of the blank being processed; the displacement sensor is electrically connected to the control system of the CNC machine tool, and the control system receives the signal from the displacement sensor to determine whether the automatic loading device should deliver the next blank to the CNC machine tool.

7. The method according to claim 1, wherein: The automatic blanking mechanism includes a material receiving device and a crawler conveyor device. The material receiving device is located directly below the workpiece processed by the CNC machine tool, and is used to receive the finished external plug-in parts cut and blanked in step 3.7 and transfer them to the crawler conveyor device; the crawler conveyor device is located on one side of the material receiving device, and is used to convey the finished external plug-in parts into the finished product box through the crawler belt.

8. The method according to claim 7, wherein: The material receiving device includes a second rotating mechanism and a material receiving tray. The material receiving tray is located directly below the workpiece processed by the CNC machine tool and is used to receive the finished external parts. The material receiving tray is fixedly connected to the second rotating mechanism, and the material receiving tray is driven to flip by the second rotating mechanism to deliver the finished external parts to the crawler of the crawler conveyor device. The second rotating mechanism is driven to rotate by the fourth motor.

9. The method according to claim 8, characterized in that: The receiving tray and crawler belt are both provided with gravity sensors for sensing whether there are finished plug-in parts. The sensors are electrically connected to the control system of the CNC machine tool and transmit the sensing signal to the control system, which controls the movement of the second rotating mechanism and the crawler conveyor device through the control system.

10. The method according to claim 1, wherein: The bar stock includes a solid bar stock and a hollow tube stock, and the hollow diameter of the hollow tube stock is smaller than the diameter of the threaded bottom hole of the external component to be processed.

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