Multi-surface numerical control machining process for joint and cylindrical parts

Abstract

The present application relates to the technical field of numerical control processing, especially to the technical field of numerical control processing of aircraft joint parts and cylindrical parts. A kind of multi-surface numerical control processing technology of joint parts and cylindrical parts includes the following steps: step one, making part bottom plane positioning hole;Step two, fix the positioning clamping device on the machine tool rotary worktable;Step three, joint parts and cylindrical parts rough machining preparation;Step four, joint parts and cylindrical parts rough machining;Step five, machine tool rotation accuracy automatic detection and compensation;Step six, re-determine the processing datum of the part;Step seven, joint parts and cylindrical parts finishing;Step eight, finishing of the double-ear precision groove of the part;Step nine, finishing of the double-ear precision hole of the part;Step ten, fitter cuts off process boss and polishes it.The present application has the following advantages:1, ensures the part processing precision, processing efficiency and processing stability;2, simplifies the process scheme of part processing.

Description

Technical Field

[0001] This invention relates to the field of CNC machining technology, and in particular to the CNC machining of aircraft connector parts and cylindrical parts. Background Technology

[0002] Aircraft connectors and cylindrical parts are characterized by their variety, complex structure, high precision requirements, and diverse materials. These parts typically incorporate precision lugs, holes, and deep grooves, and their machining features are distributed across multiple machining surfaces, necessitating multi-faceted machining. Therefore, traditional machining methods are complex in terms of process design, requiring multiple changes in clamping methods to fully machine all features on the part. This inevitably leads to low machining efficiency, some dimensions failing to meet design precision requirements, and even part scrap. The applicant filed a utility model patent application on March 29, 2022 (application number: 202220695469.1, utility model name: a multi-faceted machining clamping device for cylindrical parts), but did not describe the process involved in machining connectors and cylindrical parts. Summary of the Invention

[0003] The purpose of this invention is to provide a multi-faceted CNC machining process for joint-type and cylindrical parts to solve problems such as low efficiency and complex process schemes during machining.

[0004] To achieve the above objectives, the present invention adopts the following technical solution: a multi-face CNC machining process for joint-type and cylindrical parts, comprising the following steps.

[0005] Step 1: Make positioning holes on the bottom plane of the part;

[0006] Step 2: Fix the positioning and clamping device on the machine tool's rotary table, and position the part through the positioning holes of the positioning and clamping device and the positioning holes on the bottom plane of the part;

[0007] Step 3: Preparation before rough machining of joint and cylindrical parts: After the parts are clamped and positioned, use the positioning holes and base plane on the positioning clamping device base as the machining reference; mill the reference holes and reference surfaces of the parts as the verification references in the subsequent parts machining process.

[0008] Step 4: Rough machining of joint and cylindrical parts: Using the machining datum in Step 3, rough machining of the parts is performed. During rough machining, a milling method with small depth of cut and fast feed is used. After rough machining, the parts are left with a material allowance, which is used as the material removal amount during finishing.

[0009] Step 5: Automatic detection and compensation of machine tool rotation accuracy: An automatic detection and compensation program for machine tool rotation error is adopted, which uses probes to detect and compensate for machine tool rotation error;

[0010] Step 6: After automatically detecting and compensating for the machine tool's rotational accuracy, the machining datum of the part is redefined;

[0011] Step 7: Finishing of joint and cylindrical parts: Use the machining datum described in Step 4 as the finishing machining datum. First, leave a margin for semi-finishing, and then finish the parts in place. During the machining process, use climb milling and milling with large depth of cut and small allowance.

[0012] Step 8: Finishing the precision grooves of the double ears of the part: Before finishing the precision grooves of the ears, perform semi-finishing on the side of the precision grooves of the ears by using climb milling full cutting to finish the ear grooves in place;

[0013] Step 9: Finishing the precision holes of the two ears on the part: Use a one-time boring operation to machine the two precision holes to the desired depth, with the machining speed matching the tool retraction speed;

[0014] Step 10: The fitter cuts off the process boss and polishes it.

[0015] Preferably, in step four, the process parameters for rough machining of joint-type and cylindrical parts are as follows:

[0016] Machine tool used: Five-axis CNC machine tool;

[0017] Cutting tools used: Coated indexable end mills;

[0018] Processing parameters: cutting depth 0.8~1mm; cutting width 10~14mm; allowance for parts 3mm;

[0019] Machine tool speed: 300rpm~400rpm;

[0020] Cutting speed: 800~1000mm / min.

[0021] Preferably, a φ32mm indexable end mill with a coating is used.

[0022] Preferably, in step seven, the process parameters for the semi-finishing of joint-type and cylindrical parts are as follows:

[0023] Machine tool used: Five-axis CNC machine tool;

[0024] Cutting tools used: Coated solid carbide end mills;

[0025] Processing parameters: cutting depth 3~10mm; cutting width 8~10mm; allowance for parts 0.3~1mm;

[0026] Machine tool speed: 1000rpm~1500rpm;

[0027] Cutting speed: 600~1000mm / min.

[0028] Preferably, in step seven, the process parameters for the finishing of joint-type and cylindrical parts are as follows:

[0029] Machine tool used: Five-axis CNC machine tool;

[0030] Cutting tools used: Coated solid carbide end mills;

[0031] Processing parameters: Cutting depth 5~10mm; Cutting width 8~10mm;

[0032] Machine tool speed: 1500rpm~2000rpm;

[0033] Cutting speed: 800~1000mm / min.

[0034] Preferably, in step seven, a φ20mm coated solid carbide end mill is used.

[0035] Preferably, in step nine, the process parameters for precision hole machining of joint-type and cylindrical parts are as follows:

[0036] Machine tool used: Five-axis CNC machine tool;

[0037] Cutting tool used: Adjustable coated boring bar;

[0038] Machining parameters: Cutting depth = Hole depth;

[0039] Machine tool speed: 1500rpm~2000rpm;

[0040] Cutting speed: 100~200mm / min.

[0041] Preferably, the machine tool used is a horizontal five-axis CNC machine tool with a rotary table, and the rotary table can rotate 360º.

[0042] Preferably, in steps three and seven, when processing the part, the part is divided into two parts, A and B, along the height direction, and processed separately.

[0043] Preferably, in step two, the positioning and clamping device includes a base, a movable pad, a central tie rod, and a clamping cover plate; the bottom of the base is installed on the machine tool rotary table, and the top is provided with a base positioning hole for positioning the movable pad, a movable pad clamping hole for clamping the movable pad, and a part pull-back clamping hole for fastening joint-type and cylindrical parts; the bottom of the central tie rod is installed on the top of the base, and the top is a free end, with joint-type and cylindrical parts nested on the central tie rod; the clamping cover plate presses on the upper part of the joint-type and cylindrical parts.

[0044] Compared with the prior art, the present invention has the following advantages:

[0045] 1. It ensures the machining accuracy, efficiency, and stability of joint and cylindrical parts;

[0046] 2. The process plan for parts machining has been simplified. Attached Figure Description

[0047] Figure 1 This is a schematic diagram of the positioning and clamping device and the structure of the part before positioning and clamping in an embodiment of the present invention (including the machine tool rotary table).

[0048] Figure 2 This is a schematic diagram of the positioning and clamping device and the structure of the part after positioning and clamping in an embodiment of the present invention (including the machine tool rotary table).

[0049] Figure 1-2 In the diagram, 1-Precision clamping groove for device base; 2-Device base; 3-Modible pad; 4-Positioning hole for device base; 5-Modible pad clamping hole; 6-Part reverse pull clamping hole; 7-Central tie rod; 8-Pressure cover plate; 9-Fastening screw; 10-Joint type and cylindrical part; 11-Part reference hole; 12-Part reference surface; 13-Machine tool rotary table; 14-Process boss. Detailed Implementation

[0050] The following is in conjunction with the appendix Figure 1-2 The present invention is further described in detail as follows: A multi-faceted CNC machining process for joint-type and cylindrical parts is provided. A horizontal five-axis CNC machine tool with a rotary table (the rotary table can rotate 360º) is used to perform roughing and finishing of the entire part. Finally, the fitter cuts off the support column at the bottom of the part. The part is clamped and positioned in one go to complete the CNC machining of joint-type and cylindrical parts.

[0051] A multi-face CNC machining process for joint-type and cylindrical parts includes the following specific steps:

[0052] Step 1: Make positioning holes on the bottom plane of the part. The specific manufacturing process is drilling → reaming → boring, to achieve an accuracy of H9 or above, and ensure that the perpendicularity of the bottom plane to the central axis of the joint or cylinder is ≤0.05mm.

[0053] Step 2: Fix the positioning and clamping device on the machine tool rotary table 13, and clamp the precision slot 1 (with a positioning pin that mates with the machine tool rotary table) on the device base. Use the positioning pin to position the positioning and clamping device, ensuring that the straightness of the two positioning holes on the upper surface of the positioning and clamping device is ≤0.05mm. Then, position the part through the positioning holes of the clamping device;

[0054] As a preferred embodiment of this example, Figure 1-2 As shown, the clamping method of this positioning and clamping device is as follows:

[0055] (1) Install the connector-type and cylindrical parts 10 on the movable pad 3 (the movable pad 3 is fixed on the device base 2). The positioning hole 4 of the device base and the positioning hole at the bottom of the connector-type and cylindrical parts 10 are positioned by pins to ensure that the connector-type and cylindrical parts 10 are positioned on the movable pad 3.

[0056] (2) Insert the screw in reverse into the reverse clamping hole 6 of the part, and screw the screw into the clamping thread hole at the bottom of the joint type or cylindrical part 10 to ensure that the bottom of the joint type or cylindrical part 10 is attached and fixed on the positioning clamping device.

[0057] (3) The central tie rod 7 is fastened to the device base 2 by threads. Then, the joint type and cylindrical part 10 are inserted into the central tie rod 7 along the central deep hole. The clamping cover plate 8 presses down on the upper part of the joint type and cylindrical part 10. The fastening screw 9 is used to press the joint type and cylindrical part 10 tightly, thereby completing the clamping of the parts.

[0058] (4) The size of the positioning hole 4 of the base of the disposable clamping device is fixed. The size of the joint type and cylindrical part 10 suitable for the size of the device is made with a matching positioning hole on the bottom plane. The clamping device can then be used to process the part, thus realizing that a set of clamping devices can meet the clamping requirements of various joint type and cylindrical parts.

[0059] Step 3: Rough machining of joint and cylindrical parts: After the parts are clamped and positioned, use the positioning hole 4 of the device base and the base plane as machining datums; first, mill the part datum hole 11 and the part datum surface 12 as verification datums in the subsequent part machining process. To ensure the rigidity of the parts during machining, such as... Figure 2 As shown, the part is divided into two parts, A and B, along its height for machining. A coated indexable milling cutter is used for roughing. First, the upper part is rough-machined, leaving a 3mm allowance for material removal during finishing. During roughing, a shallow depth of cut and rapid feed rate should be used to prevent excessive cutting forces that could cause vibration in the part during machining.

[0060] Step 4: Use the machining datum and milling method from Step 3. Perform rough machining on part B of the part. This separate machining ensures the stability of the part during the machining process. Leave a 3mm allowance for the rough machining of the lower part of the part as the material removal amount during finishing. Since the overall stability of the part is better after rough machining of the lower part, the milling parameters of the part can be appropriately increased.

[0061] Step 5, Automatic detection and compensation of machine tool rotation accuracy: The developed automatic detection and compensation program for machine tool rotation error is used to detect and compensate for machine tool rotation error using a probe, thereby eliminating machining error caused by machine tool rotation error;

[0062] Step 6: After automatic detection and compensation of machine tool rotation accuracy, the machining datum of the part is redefined; the machining datum of the part is redefined by using a probe to measure the datum hole 11 and the datum surface 12 of the part to ensure the precision of the part's finishing.

[0063] Step 7: Finishing of joint and cylindrical parts: Use the machining datum described in Step 4 as the finishing datum. Use a coated solid carbide end mill for finishing. First, leave a 0.3~1mm allowance for semi-finishing to check if the dimensions of the part meet the requirements, and then finish the part in place. To ensure the rigidity of the part during machining, such as... Figure 2 As shown, the part is still divided into two parts, A and B, along its height for machining. During machining, climb milling with large depth of cut and small allowance should be used as much as possible.

[0064] Step 8: Finish machining of the precision grooves on the double ears of the part: such as Figure 1 As shown, the lower part of the connector and cylindrical parts has a pair of precision H9 double lug slots. Before finishing the lug slots, the sides of the lug slots need to be semi-finished (leaving a 0.3mm allowance for finishing) to ensure that the semi-finished lug slots meet the dimensional requirements. Then, the lug slots are finished by using climb milling full cutting.

[0065] Step 9: Finish machining of the precision holes for the double lugs on the part: such as Figure 1 As shown, the precision lug hole size of the connector-type and cylindrical parts is 39mm (accuracy H8) and the concentricity is 0.1mm. The precision holes of these two lugs are machined in a single boring operation, with the machining speed and retraction speed being consistent to ensure that the hole wall surface finish meets the requirements.

[0066] Step 10: The fitter cuts off the process boss 14 and polishes it.

[0067] As a preferred embodiment of this invention, the specific parameters are as follows:

[0068] 1) Rough machining of joint-type and cylindrical parts:

[0069] Machine tool used: Horizontal five-axis CNC machine tool with a rotary table (the rotary table can rotate 360 ​​degrees);

[0070] Cutting tools used: φ32mm indexable end mill with coating;

[0071] Processing parameters: cutting depth 0.8~1mm; cutting width 10~14mm; allowance for parts 3mm;

[0072] Machine tool speed: 300rpm~400rpm;

[0073] Cutting speed: 800~1000mm / min.

[0074] 2) Semi-finishing of joint and cylindrical parts:

[0075] Machine tool used: Horizontal five-axis CNC machine tool with a rotary table (the rotary table can rotate 360 ​​degrees);

[0076] Cutting tool used: φ20mm coated solid carbide end mill;

[0077] Processing parameters: cutting depth 3~10mm; cutting width 8~10mm; allowance for parts 0.3~1mm;

[0078] Machine tool speed: 1000rpm~1500rpm;

[0079] Cutting speed: 600~1000mm / min.

[0080] 3) Finishing of joint and cylindrical parts:

[0081] Machine tool used: Horizontal five-axis CNC machine tool with a rotary table (the rotary table can rotate 360 ​​degrees);

[0082] Cutting tool used: φ20mm coated solid carbide end mill;

[0083] Processing parameters: Cutting depth 5~10mm; Cutting width 8~10mm;

[0084] Machine tool speed: 1500rpm~2000rpm;

[0085] Cutting speed: 800~1000mm / min.

[0086] 4) Precision machining of holes in connectors and cylindrical parts:

[0087] Machine tool used: Horizontal five-axis CNC machine tool with a rotary table (the rotary table can rotate 360 ​​degrees);

[0088] Cutting tool used: Adjustable coated boring bar;

[0089] Machining parameters: Cutting depth = Hole depth;

[0090] Machine tool speed: 1500rpm~2000rpm;

[0091] Cutting speed: 100~200mm / min.

[0092] The above manufacturing process, when used for CNC machining of aircraft connectors and cylindrical parts, can effectively reduce the error caused by multiple clamping operations during the machining process, and ensure the machining accuracy, efficiency, and stability of connectors and cylindrical parts.

Claims

1. A multi-face CNC machining process for joint-type and cylindrical parts, characterized in that: It comprises the following steps, Step one, make the part bottom plane positioning hole; Step two, fix the positioning clamping device on the machine tool rotary workbench, and position the part through the positioning hole of the positioning clamping device and the part bottom plane positioning hole; Step three, joint type, cylinder type part rough machining preparation: after the part clamping and positioning is completed, take the positioning hole and the bottom plane of the positioning clamping device base as the machining reference; Mill the reference hole and reference surface of the part as the verification reference in the subsequent part machining process; Step four, joint type, cylinder type part rough machining: use the machining reference of step three to rough machine the part, and use small cutting depth and fast feed milling method in the rough machining process. After rough machining, the part has a margin as the material removal amount for finishing; Step five, machine tool rotation accuracy automatic detection and compensation: use the machine tool rotation error automatic detection and compensation program to detect and compensate the machine tool rotation error by using the probe; Step six, after using the machine tool rotation accuracy automatic detection and compensation, determine the machining reference of the part again; Step seven, joint type, cylinder type part finishing: use the machining reference described in step six as the finishing machining reference, first reserve a margin for semi-finishing, and then finish the part in place; Use the milling method of infeed milling, large cutting depth and small margin during machining; Step eight, finishing of the double ear precision groove of the part: before finishing the ear precision groove, semi-finish the side surface of the ear precision groove, and use the infeed milling method to finish the ear groove in place; Step nine, finishing of the double ear precision hole of the part: use one-time boring to finish the two precision holes in place, and the machining speed is consistent with the tool retracting speed; Step ten, cut off the process boss and polish it; In step two, the positioning clamping device comprises a base, movable pads, a center pull rod, and a pressing cover plate. The base is installed on the machine tool rotary workbench at the bottom, and the top is provided with base positioning holes for positioning movable pads, movable pad clamping holes for clamping movable pads, and part reverse pull clamping holes for fastening joint type and cylindrical parts. The center pull rod is installed at the bottom of the base, and the top is a free end, on which the joint type and cylindrical parts are nested. The pressing cover plate is pressed on the upper part of the joint type and cylindrical parts.

2. The multi-surface numerical control machining process for joint-like, cylindrical part according to claim 1, characterized in that: In step four, the process parameters for rough machining of joint type and cylindrical parts are as follows: Use machine tool: five-axis numerical control machine tool; Use tool: indexable coated milling cutter; Machining parameters: cutting depth 0.8~1mm; cutting width 10~14mm; part margin 3mm; Machine tool speed: 300rpm~400rpm; Cutting speed: 800~1000mm / min.

3. The CNC machining process for joint-type and cylindrical parts according to claim 2, characterized in that: The tool used is a φ32mm indexable coated milling cutter.

4. The multi-surface numerical control machining process for joint-like, cylindrical part according to claim 1, characterized in that: In step seven, the process parameters for semi-finishing of joint type and cylindrical parts are as follows: Use machine tool: five-axis numerical control machine tool; Use tool: coated solid carbide milling cutter; Machining parameters: cutting depth 3~10mm; cutting width 8~10mm; part margin 0.3~1mm; Machine tool speed: 1000rpm~1500rpm; Cutting speed: 600~1000mm / min.

5. The multi-surface numerical control machining process for joint-like, cylindrical part according to claim 1, characterized in that: In step seven, the process parameters for finishing joint type and cylindrical parts are: Machine tool used: five-axis CNC machine tool; Cutter used: coated solid carbide milling cutter; Processing parameters: cutting depth 5-10 mm; cutting width 8-10 mm; Machine tool speed: 1500 rpm-2000 rpm; Cutting speed: 800-1000 mm / min.

6. The multi-surface numerical control machining process of joint-like, cylindrical-like parts according to claim 4 or 5, characterized in that: In step seven, the cutter used is a φ20 mm coated solid carbide milling cutter.

7. The multi-surface numerical control machining process for joint-like, cylindrical part according to claim 1, characterized in that: In step nine, the process parameters for finishing precision holes of joint type and cylindrical parts are: Machine tool used: five-axis CNC machine tool; Cutter used: adjustable coated boring cutter; Processing parameters: cutting depth = hole depth; Machine tool speed: 1500 rpm-2000 rpm; Cutting speed: 100-200 mm / min.

8. The multi-surface numerical control machining process for joint-like, cylindrical part according to claim 1, characterized in that: The machine tool used is a horizontal five-axis CNC machine tool with a rotary table, and the rotary table can rotate 360º.

9. The multi-surface numerical control machining process for joint-like, cylindrical part according to claim 1, characterized in that: In steps three and seven, when processing the parts, the parts are divided into A and B in the height direction, and are processed separately.

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