Machining process method for outer hanging piece of combustion chamber shell

Abstract

The invention discloses a machining process method for an external hanging piece of a combustion chamber shell, and belongs to the technical field of precision machining. According to the process method, a full-automatic machining mode is adopted, and a turning and milling combined machining process method is used for replacing a traditional external hanging piece machining process. The consistency of machining dimensional tolerance of the outer hanging piece of the combustion chamber shell is guaranteed, the symmetry degree and perpendicularity of a threaded hole are guaranteed, after the machined outer hanging piece and the combustion chamber shell are subjected to welding, heat treatment and threaded hole cleaning through a screw tap, the qualification rate of the outer hanging piece reaches 100%, and the outer hanging piece machining process method is rapid and efficient. The problems that existing external hanging piece machining procedures are tedious, machining efficiency is low, and machining precision is difficult to guarantee are solved.

Description

Technical Field

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

[0002] External parts are mainly used in military solid rocket engines. They are welded to the outer wall of the combustion chamber shell and are used to install cable protection covers and other components on the outer wall of the shell. There are threaded holes on the external parts, and the cable protection covers and other components can be installed through screw connections.

[0003] External parts are generally made of metal materials, usually 20CrMnTi, 30CrMnSiA or D406A, etc., and are mostly rectangular blocks with small sizes and high precision requirements. Its outer dimensions are no more than 20mm×20mm, and the outer dimension tolerance is about 0.10mm; the thickness is 3mm~8mm, and the thickness dimension tolerance is about 0~0.05mm; there is a threaded hole at the center, and the threaded hole specifications are M3mm~M8mm; the threaded hole accuracy is 7H, the threaded hole is no more than 0.1mm symmetry to the external part, and the verticality to the end face is no more than 0.05mm, and the shape and position tolerance is not easy to guarantee during processing. Figure 1 This is a schematic diagram of an engine combustion chamber casing external plug-in, which requires a dimensional tolerance of 0.10 mm.

[0004] The external parts must first be machined, then welded to the combustion chamber shell. After being annealed, quenched and tempered together with the combustion chamber shell, the threads are 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 general raw material is φ180mm~φ200mm bar material, which needs 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. The process flow mainly has the following defects:

[0006] 1. Grinding and wire cutting processes are time-consuming and labor-intensive, and clamp work is manual work. The number of external parts to be processed is large, and 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 external parts requires 5 processes 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 exceed the tolerance after the tap cleaning process due to deformation. This leads to the inability to assemble the screws due to the excessive position accuracy of the threaded holes when assembling the cable protection cover, or the thread strength is reduced due to the excessive threaded hole accuracy. In severe cases, the entire combustion chamber shell is scrapped, causing great waste and poor economy. Summary of the invention

[0011] Technical problem to be solved: In order to avoid the shortcomings of the prior art, 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 mechanical processing procedures, low processing efficiency and difficulty in ensuring processing accuracy of existing external plug-in parts.

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

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

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

[0015] The automatic loading device comprises: 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 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 pushing;

[0016] Step 3: Automatic processing: using a combined lathe and milling process, a single external part is clamped and processed 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, the axial turning length is the first length; turning the threaded bottom hole, the axial turning length is also the first length; turning the countersink of the outer end of the threaded bottom hole to the drawing size; the first length is greater than the thickness of the external component;

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

[0020] Step 3.4, turning the internal thread in the thread bottom hole where the back cut groove is processed 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 blank after turning, and the clearance groove is used to cut off the processed external part from the blank. The distance between the outer wall of the clearance groove and the outer end surface of the processed blank is the thickness dimension of the external part. After step 3.5 is completed, a rough blank of the external part is obtained;

[0022] Step 3.6, milling the rough shape of the external plug-in so that its shape meets the requirements of the external plug-in drawing;

[0023] After step 3.7 and step 3.6 are completed, the outer plug-in is cut off at the clearance groove 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, repeating steps 3 and 4 until one blank is processed, automatically loading the blank to the CNC machine tool through step 2, and then repeating steps 3 and 4 to process another blank; repeating 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 component 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 one time; the first rotating mechanism at the bottom of the storage mechanism is provided with shifting teeth, and the rotating mechanism is driven to rotate by the first motor, driving the shifting teeth 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 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 an 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 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 is 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, which controls the operation of the second rotating mechanism and the crawler conveyor through the control system.

[0034] A further technical solution of the present invention is as follows: the bar material comprises 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 processing method of the combustion chamber shell external plug-in provided by the present invention has high processing accuracy and good consistency of 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 processing size tolerance of the external plug-in 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%, which ensures 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 with lengthy procedures, many control points, cumbersome process, poor processing quality consistency, and difficult to ensure processing accuracy.

[0037] The method of the present invention has high production efficiency. Taking a single blank with a length of 1000 mm and a thickness of 3.5 mm as an example, through the processing method of the present invention, a single blank can be continuously and uninterruptedly processed into at least 100 external parts. According to the automatic loading device, 15 blanks are fully loaded at a time, and each external part takes 5 minutes to process, and each blank takes 500 minutes. A single full loading can be processed continuously for 125 hours, a total of 5.2 days, that is, a single loading can be processed continuously for 24 hours for 5.2 days, and 1,500 external parts can be processed. If the existing process method is used, it takes 20.8 days to process 1,500 external parts. After the improvement of this method, it 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 hole during mechanical processing of the external part, adopts the principle of deformation tolerance, ensures the final accuracy requirements of the threaded hole after the external part is welded and heat treated, eliminates the quality risks of the external part in the state of the combustion chamber shell, and eliminates the quality risks of the threaded hole from the process method, and has good processability. And by changing the thread processing direction of the traditional processing method, by threading from one end of the countersink of the threaded hole, compared with the existing method of tapping from the back of the countersink, the final accuracy of the threaded hole is significantly improved. Through process verification, the thread tapping starts from the non-counterbore surface, and the final product qualification rate is only about 70%. By threading from the countersink end through the method of the present invention, the thread accuracy level is improved by two levels, which ensures that the subsequent external part has a 100% final 7H precision quality qualification rate.

[0039] The method of the 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 accuracy 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 work by fitters 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 has a high level of automation. Through the automatic feeding device, automatic processing method and automatic unloading mechanism, the whole process is automated, the labor intensity of the operator is reduced, and the influence of human factors on product quality is also avoided. Through the automation of the entire production process, unmanned feeding and unloading of the plug-in within the 12-hour feeding cycle can be achieved. The improvement of the level of production automation can effectively improve product consistency and production efficiency, break through the bottleneck of quality instability, and reduce the discreteness 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 It is the process flow chart of the existing plug-in processing;

[0043] Figure 3 This is a process flow chart of the external parts processing of the present invention;

[0044] Figure 4 It is a schematic diagram of turning the outer circle, thread bottom hole and countersink in the 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 This is a schematic diagram of a threaded hole in an embodiment of the present invention;

[0047] Figure 7 This is a 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] Fig. 9 This is a schematic diagram of a finished plug-in product in an embodiment of the present invention;

[0050] Fig.10 It is a structural schematic diagram of an automatic feeding device in an embodiment of the present invention;

[0051] Fig.11It is a structural schematic diagram of the automatic blanking mechanism in an embodiment of the present invention;

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

[0053] Explanation of the accompanying reference numerals: 1. Blank, 11. Outer end face, 12. Outer circle, 13. Threaded bottom hole, 131. Threaded hole, 14. Countersunk hole, 15. Back-off groove, 16. Make way 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 be used 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 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 referred device or element 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 long processing steps, low processing accuracy, poor quality consistency, and low threaded hole accuracy after welding. In this embodiment, an automated processing method is used, and the specific process flow is as follows: Figure 3 As shown, the conventional process of existing external parts is replaced, the processing efficiency is improved, and the processing accuracy is guaranteed. 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 is tested to reach 100%, 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 state, 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-milling compound processing unit CK-46.

[0059] Step 1, material preparation: select a bar with a diameter of φ18 mm for material cutting, cut the bar to form a blank 1 with a length of 800 mm, and cut 15 bars in total. The bar can be a solid bar or a hollow tube. When a hollow tube is selected, its hollow diameter should be smaller than the diameter of the threaded bottom hole of the external part to be processed. In this embodiment, a solid bar with a diameter of φ18 mm is selected.

[0060] Step 2, automatic loading: The blank 1 unloaded in step 1 is conveyed to the CNC machine tool by the automatic loading device 2. Fig.10 As shown, the automatic loading device 2 includes: a storage mechanism 21, a propulsion mechanism 22 and a guide tube 23. The storage mechanism 21 is used to store the blank 1 discharged in step 1, and a first rotating mechanism 211 is provided at the bottom of the storage mechanism 21 for transferring the blank 1 into the propulsion mechanism 22. The propulsion mechanism 22 is located below the storage mechanism 21, and is used to push the blank 1 horizontally into the guide tube 23 and push it to the hydraulic chuck 3 servo device of the machine tool. The guide tube 23 is a hollow tube, which connects the propulsion mechanism 22 and the hydraulic chuck 3 servo device of the CNC machine tool, and plays a guiding role in the pushing process of the blank 1.

[0061] For details, see Fig.10 The storage mechanism 21 stores the 15 blanks 1 discharged in step 1 in the storage mechanism 21 by manual loading. The required 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 to rotate by the first motor, 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, and 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. The pneumatic propulsion device is driven by the second motor and can move up and down in the propulsion mechanism 22, so that the blanking area 221 forms two stations, one is a waiting position and the other is 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 horizontally pushed into the guide tube 23 through the pneumatic propulsion of the external pneumatic system 24. The waiting position of the push rod 222 is located directly below the working position of the blanking area 221, and the push rod 222 is driven by the third motor to move up and down. 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, so as 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 blanks 1 of different lengths.

[0063] Step 3: Automatic processing: Using a turning and milling composite processing method, a single external component is clamped and processed 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 procedure settings.

[0065] Step 3.2, see 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, consider the reserved processing amount for subsequent milling, and consider the reserved processing amount for subsequent cutting when turning the axial length. Then turn the threaded bottom hole 13, and the axial turning length of the threaded bottom hole 13 is 10mm. Finally, turn the countersink 14 at the outer end of the threaded bottom hole 13, the diameter of the countersink 14 is φ6mm, and the turning depth is

[0066] Step 3.3, see Figure 5In this step, a back-cut groove 15 is machined in the threaded bottom hole 13 processed in step 3.2. The size of the back-cut groove 15 is 3mm×φ5mm, that is, the width of the back-cut groove 15 is 3mm and the major diameter is φ5mm. Ensure that the distance from the inner side wall of the back-cut groove 15 to the outer end face is 6.5mm.

[0067] Step 3.4, see 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, and the thread accuracy grade is 5H, so as 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 is completed, a clearance groove 16 is machined on the outer circle of the blank 1 that has been turned to φ17mm. The size of the clearance groove 16 is 3mm×φ8mm, that is, the groove width of the clearance groove 16 is 3mm, and the minimum diameter size is φ8mm. The clearance groove 16 has the same width as the retreat groove 15 and is coplanar. The outer wall of the clearance groove 16 is 3.5mm away from the outer end face at this time. The clearance groove 16 is used to cut off the subsequent processed external parts from here to separate them from the blank 1. After step 3.5 is completed, a rough blank of the external parts 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 shape in step 3.6 is completed, a cutting tool is used to cut off at the clearance groove 16 to obtain Fig. 9 The finished product 4 of the external part is shown.

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

[0072] See also Fig.11 In this embodiment, an automatic blanking mechanism 5 is provided, which 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 product 4 processed in step 3.7. The receiving tray 53 is fixedly connected to the second rotating mechanism 52, and the receiving tray 53 is driven to flip by the second rotating mechanism 52, so as to deliver the finished plug-in product 4 in the receiving tray 53 to the crawler of the crawler conveyor 51. The second rotating mechanism 52 is driven to rotate by the fourth motor. The crawler conveyor 51 is located on one side of the second rotating mechanism 52, and is used to automatically deliver the finished plug-in product 4 to the finished product box 54 through 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 step 3-step 4 until one blank 1 is processed. In this embodiment, the hydraulic chuck 3 is provided with a blank automatic propulsion device, which is used to propel the blank 1 after one external component is processed and blanked. After one external component finished product 4 is processed and blanked, the machine tool control system controls the hydraulic chuck 3 to release the blank 1, and controls the automatic propulsion device to propel the blank 1 forward a processing distance. After it is in place, the hydraulic chuck 3 continues to clamp the blank 1 to process the next external component. In this embodiment, one blank 1 can process 110 external component finished products 4.

[0075] When a blank 1 is processed, the control system of the CNC machine tool controls the automatic feeding device 2 to automatically feed the blank to the CNC machine tool, and then repeats steps 3-4 to process another blank 1. Specifically, a displacement sensor is provided in the guide tube 23 near one end of the hydraulic chuck 3 to sense the displacement of the blank 1 being processed. The displacement sensor is electrically connected to the control system of the CNC machine tool. When the sensor detects that the blank 1 is not within the detection range, the control system receives the detection signal of the sensor and controls the automatic feeding device 2 to deliver the next blank 1 to the CNC machine tool. Repeat steps 2-4 until the 15 blanks 1 in the storage mechanism 21 are processed, and then the feeding cycle is repeated for further processing.

[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 also Fig.12 The external parts processed by the processing method of this embodiment are welded to the combustion chamber cylinder by manual argon arc welding. The welds meet the requirements of QJ175-93 II grade welds through magnetic particle inspection. After the D406A material is annealed, quenched, and tempered, the M4-7H threaded holes of the external parts are cleaned with an M4-6H tap and the thread plug gauge is used. Inspection, all passed.

[0078] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary 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 intent of the present invention.

Claims

1. A method for processing a combustion chamber housing external component, characterized in that: The following steps are involved: Step 1: Prepare the blank: take a bar with a diameter not exceeding φ30mm and cut it into a blank with a length of 800mm to 1000mm; Step 2, automatic loading: the blanks unloaded in step 1 are conveyed to the CNC machine tool through the automatic loading device; The automatic loading device comprises: 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 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 pushing; Step 3: Automatic processing: using a combined lathe and milling process, a single external part is clamped and processed 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, the axial turning length is the first length; turning the threaded bottom hole, the axial turning length is also the first length; turning the countersink of the outer end of the threaded bottom hole to the drawing size; the first length is greater than the thickness of the external component; Step 3.3, turning a back cutter groove in the thread bottom hole processed in step 3.2, wherein the distance between the outer wall of the back cutter groove and the outer end surface of the blank processed in step 3.2 is the thickness dimension of the external part; Step 3.4, turning the internal thread in the thread bottom hole where the back cut groove is processed in step 3.3, the thread accuracy is 2 levels higher than the accuracy required by the external component thread hole drawing; After step 3.5 and step 3.4 are completed, a clearance groove is turned on the outer circle of the blank after turning, and the clearance groove is used to cut off the processed external part from the blank. The distance between the outer wall of the clearance groove and the outer end surface of the blank after processing in step 3.2 is the thickness dimension of the external part. After step 3.5 is completed, a rough blank of the external part is obtained; Step 3.6, milling the rough shape of the external plug-in so that its shape meets the requirements of the external plug-in drawing; After step 3.7 and step 3.6 are completed, the outer plug-in is cut off at the clearance groove 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, repeating steps 3 and 4 until one blank is processed, automatically loading the blank to the CNC machine tool through step 2, and then repeating steps 3 and 4 to process another blank; repeating steps 2 and 4 until the blanks in the storage mechanism are processed.

2. The method according to claim 1, characterized in that: The hydraulic chuck is provided with an automatic blank advancing device, which is used to advance the blank after the blanking of an external part is completed.

3. The method according to claim 1, characterized in that: A maximum of 15 blanks can be placed in the storage mechanism at one time; a first rotating mechanism at the bottom of the storage mechanism is provided with shifting teeth, which are driven by a 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 pushing mechanism.

4. The method according to claim 3, characterized in that: 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 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 an 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, characterized in that: A displacement sensor is provided in the guide tube at one end near 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 of the displacement sensor to determine whether the automatic feeding device should deliver the next blank to the CNC machine tool.

7. The method according to claim 1, characterized in that: 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.

8. The method according to claim 7, characterized in that: 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 to transmit the sensing signal to the control system, which controls the operation of the second rotating mechanism and the crawler conveyor through the control system.

10. The method according to claim 1, characterized in that: 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 thread bottom hole of the external part to be processed.

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