Helicopter rotor system shimmy damper aluminum alloy complex cylinder part machining method

Abstract

The invention belongs to the field of machining, and relates to a machining method for aluminum alloy complex cylinder parts of a shimmy damper of a helicopter rotor system. The method comprises the steps that the machining allowance of a forging blank is distributed, an alignment datum is transferred to a standard foundation plate of the alignment datum from the forging blank, and the forging blank is clamped on the standard foundation plate provided with the alignment datum; the alignment reference is machined, and the machined alignment reference becomes the positioning reference of rough machining; roughly machining a central inner hole of the forging blank according to the rough machining positioning reference; clamping and roughly machining the mandrel by adopting a special mandrel, roughly machining a fork opening of the workpiece blank, and forming a positioning hole; the roughly-machined forging blank positioning hole, the roughly-machined positioning reference and a special lathe tool are installed in a matched mode, and a center inner hole is finely machined; and a special mandrel is adopted for clamping and finish machining of the mandrel, a fork opening of the forge piece blank is subjected to finish machining, and drilling is conducted.

Description

Technical Field

[0001] The invention belongs to the field of mechanical processing and relates to a method for processing aluminum alloy complex cylinder parts of a helicopter rotor system damper. Background Art

[0002] The shimmy damper is a key component in the helicopter rotor system. It can provide sufficient rigidity and damping for the shimmy motion of the helicopter blades to suppress the ground and air resonance of the helicopter, thereby improving the stability of the helicopter. The outer cylinder of the shimmy damper is a complex cylinder part with an aluminum alloy forging as the blank, and is the most important component of the shimmy damper. The existing processing method for this type of parts uses manual work such as turning, milling, and fittering. During the processing process, it is necessary to repeatedly switch between the above types of work, resulting in a long processing cycle and unstable processing quality. Summary of the invention

[0003] Purpose of the invention: To propose a method for machining aluminum alloy complex cylinder parts with centralized process, stability and high efficiency.

[0004] Technical Solution

[0005] A method for processing aluminum alloy complex cylinder parts of a helicopter rotor system damper is provided, comprising:

[0006] For the machining allowance distribution of the forging blank, the alignment reference is transferred from the forging blank to the standard base plate of the alignment reference, and the forging blank is clamped on the standard base plate equipped with the alignment reference;

[0007] Process the alignment datum so that the alignment datum after processing becomes the positioning datum for rough processing;

[0008] Rough-machine the center inner hole of the forging blank according to the positioning reference of rough machining;

[0009] Adopt special mandrel clamping and rough machining mandrel, rough machining the fork and positioning hole of the blank;

[0010] Install the rough-machined forging blank positioning hole and the rough-machined positioning reference with the special lathe tooling, and finish the center inner hole;

[0011] Special mandrel clamping and finishing mandrel are used to finish the fork and drilling of forging blanks.

[0012] Furthermore, the method further comprises:

[0013] Threaded holes, honing, dimension inspection, fluorescent flaw detection, anodizing.

[0014] Further, for the machining allowance distribution of the forging blank, the alignment reference is transferred from the forging blank to the standard base plate of the alignment reference, and the forging blank is clamped on the standard base plate equipped with the alignment reference, including:

[0015] Use laser scanning or visual recognition to check the machining allowance of the forging blank to ensure that the minimum radial machining allowance is not less than 0.2mm; then clamp the forging blank on a standard base plate equipped with an alignment datum, and use laser scanning again to determine the positional relationship between the forging blank and the alignment datum.

[0016] Further, the processing and alignment of the benchmark includes:

[0017] The machining and alignment are carried out according to the positional relationship between the forging blank and the alignment datum, and the positioning datum for rough machining is produced.

[0018] Further, according to the positioning reference of rough machining, the center inner hole of the forging blank is rough machined, including:

[0019] Rough machined parts center hole size d0 +0.03 Dimensional accuracy, roughness R a 3.2, Process the end face of the hole, ensure that the end face is perpendicular to the axis of the center hole to 0.005mm, and leave a processing allowance of 1mm at each place after processing;

[0020] At the same time, the processing of the axial positioning plane is completed.

[0021] Further, the special mandrel clamping includes: a center positioning mandrel, a clamping mechanism, a heightened base, and an axial positioning device;

[0022] The center positioning mandrel is a rough machining mandrel or a fine machining mandrel; the center positioning mandrel is installed on the heightened base, the forging blank is sleeved on the center positioning mandrel through its own rough machining center hole, and the clamping mechanism presses the lower end surface of the forging blank on the heightened base; the axial positioning device is installed on the heightened base, and cooperates with the rough machining positioning reference to realize axial positioning;

[0023] Adopt special mandrel clamping and rough machining mandrel, rough machining workpiece blank fork, set positioning hole, including:

[0024] The fork shape is rough-machined using a special spindle clamp suitable for a five-axis CNC milling machine, leaving a 1mm machining allowance after rough machining; positioning holes are made at the radial holes of the forging blank, and the positioning holes must ensure dimensional accuracy H9 and roughness R a 1.6.

[0025] Furthermore, the specially made lathe tooling includes: a transfer plate, a counterweight, a clamping mechanism, a clamping body, a positioning pin, a center height adjustment mechanism, and a directional pin;

[0026] One end of the clamp body is connected to the CNC lathe spindle interface through an adapter plate, and a counterweight is also installed; a center height adjustment mechanism is arranged on the upper end surface of the other end of the clamp body, and a positioning pin and a directional pin are arranged on the center height adjustment mechanism. The forging blank is horizontally placed on the center height adjustment mechanism, and the positioning pin and the directional pin are both positioned in cooperation with the rough-machined positioning holes; a clamping mechanism is installed on the clamp body, and is used to clamp the forging blank on the center height adjustment mechanism;

[0027] The rough-machined forging blank positioning hole and the rough-machined positioning reference are installed with the special lathe tooling to fine-machine the center inner hole, including:

[0028] Using a special lathe tooling, the part is clamped on the spindle of the CNC lathe, and the center hole of the part is finely machined to a size of D0. +0.03 , after finishing, leave 0.05mm honing allowance to ensure the roughness R a 16.

[0029] Furthermore, a special mandrel is used for clamping and finishing the mandrel to finish the fork and drilling of the forged blank, including:

[0030] Use a special mandrel clamp suitable for a five-axis CNC milling machine to complete the fine machining of the fork mouth contour and bushing hole in one positioning: When machining the bushing installation hole at the fork mouth, the machining should be completed from one side of the fork mouth in one time. The center positioning mandrel and the center hole size D +0.03 0.03~0.05mm;

[0031] At the same time, before drilling hydraulic holes in various places, it is necessary to complete the fine processing of the hole positioning surface first, then use the center drill to make the guide hole, and finally use a special carbide step drill to complete the processing of the step hole and the hole chamfer in one go.

[0032] Beneficial effects:

[0033] Aiming at the processing process of complex cylindrical parts of aluminum alloy, the present invention innovatively proposes to use a five-axis CNC machine tool to complete the rough processing of the center positioning hole and the axial positioning plane in one clamping, which greatly improves the dimensional accuracy and shape and position accuracy of the positioning reference and enhances the reliability of positioning; innovatively proposes a spindle tool suitable for CNC lathes, which can realize the processing of all structural dimensions of the center hole of the part by using the same positioning reference, and ensure the dimensional accuracy and coaxiality requirements; innovatively proposes a spindle suitable for a five-axis CNC milling machine, which can complete the processing of the fork contour, bushing mounting holes and various hydraulic holes in one clamping, and effectively ensure the shape and position tolerance requirements of the parts; innovatively proposes to use a special carbide step drill to complete the processing of the step hole and the chamfer of the hole mouth in one time, which greatly reduces the number of tools in the hole processing process and improves the concentricity of the step hole; through the above technical scheme, the part processing process is basically all CNC-controlled, and the number of processing turnovers is greatly reduced, the processing efficiency is significantly improved, and high-quality and efficient processing of complex cylindrical parts of aluminum alloy is achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a flow chart of the present invention.

[0035] Figure 2 It is a schematic diagram of the structure of the special spindle of the five-axis CNC milling machine.

[0036] Figure 3 This is a schematic diagram of the structure of the lathe spindle tooling. DETAILED DESCRIPTION

[0037] The present invention provides a method for processing aluminum alloy complex cylinder parts, such as Figure 1 As shown, including:

[0038] Step 1: Allocate the remaining amount.

[0039] Step 2: Prepare the rough machining positioning reference.

[0040] Step 3: Rough machining of the center inner hole.

[0041] Step 4: Rough process the fork mouth and make the positioning hole.

[0042] Step 5: Finish the center inner hole.

[0043] Step 6: Finish the fork and drill holes.

[0044] Step 7: Make threaded holes.

[0045] Step 8: Honing.

[0046] Step 9: Size detection.

[0047] Step 10: Fluorescent flaw detection.

[0048] Step 11: anodization.

[0049] Step 1 is as follows: Use laser scanning or visual recognition to check the machining allowance of the forging blank to ensure that the minimum radial machining allowance is not less than 0.2mm; then clamp the part blank on a standard base plate equipped with an alignment datum, and use laser scanning again to determine the positional relationship between the part and the alignment datum. When clamping, ensure that the rough datum to be made is reachable in step 2.

[0050] Step 2 is specifically as follows: after machining and aligning according to the positional relationship between the part and the alignment datum determined in step 1, the rough machining positioning datum of the part is machined.

[0051] Step 3 is to rough-machine the center hole size d of the part. +0.03 0 dimensional accuracy, roughness Ra3.2, process the end face of the hole, ensure the end face is perpendicular to the center hole axis 0.005mm, and leave a processing allowance of 1mm at each place after processing. At the same time, complete the processing of the axial positioning plane.

[0052] Step 4 is as follows: Use a special mandrel clamp suitable for a five-axis CNC milling machine to perform rough machining on the fork shape, leaving a 1mm machining allowance after rough machining. Make a locating hole at the radial hole of the part, and the locating hole must ensure a dimensional accuracy of H9 and a roughness of Ra1.6. Leave a finishing allowance of 0.5mm at the locating hole. Special mandrels suitable for five-axis CNC milling machines such as Figure 2 , where 1 is the center positioning spindle, 2 is the clamping mechanism, 3 is the heightened base, and 4 is the axial positioning device. The size of the center positioning spindle 1 should be guaranteed to be consistent with the center hole size d +0.03 0 The matching clearance is 0.03-0.05mm. The outer dimensions of the heightened base 3 need to be determined according to the spindle size and the stroke of each axis of the processing equipment.

[0053] Step 5 is as follows: Use a special lathe tool to clamp the part on the spindle of the CNC lathe and perform fine machining on the center hole of the part to a machining size of D0. +0.03 After finishing, leave 0.05mm honing allowance to ensure the roughness Ra16. Special tooling such as Figure 3 As shown, 1' is the adapter plate, 2' is the counterweight block, 3' is the clamping mechanism, 4' is the clamp body, 5' is the positioning pin, 6' is the center height adjustment mechanism, and 7' is the directional pin. The mounting plate 1' needs to be designed according to the selected CNC lathe spindle interface form, the counterweight block 2' is used to adjust the center of gravity of the fixture, the positioning pin 5' and the directional pin 7' need to match the positioning holes in step 4, the dimensional accuracy is f6, the roughness is Ra0.8, the positioning hole is a cylindrical pin, and the directional pin is a diamond pin;

[0054] Step 6 is as follows: Use a special mandrel clamp suitable for a five-axis CNC milling machine to complete the fine machining of the fork mouth contour and bushing hole in one positioning. When machining the bushing installation hole at the fork mouth, the machining should be completed from one side of the fork mouth in one time. The special mandrel is consistent with the requirements of step 4. The center positioning mandrel 1 and the center hole size D +0.03 0 The clearance is 0.03~0.05mm. At the same time, before drilling hydraulic holes, the positioning surface of the hole mouth should be finely processed, and then the guide hole should be drilled with a center drill. Finally, a special carbide step drill is used to complete the processing of the step hole and the chamfer of the hole mouth in one step.

[0055] Step 7 is specifically as follows: use taps of corresponding specifications to complete the processing of threaded holes at various locations;

[0056] Step 8 is as follows: use honing and special honing oilstone to super-finish the center hole of the part, with the machining amount not exceeding 0.05mm and ensuring the roughness Ra0.32;

[0057] Step 9 is as follows: Use an internal micrometer to check the hole size at each location, and use a three-coordinate measuring instrument to check the coaxiality, verticality, parallelism and other geometric tolerances;

[0058] Step 10 is specifically as follows: using fluorescent flaw detection to detect micro cracks on the surface of the parts to ensure the fatigue performance requirements of the parts;

[0059] Step 11 specifically includes: performing chromic acid anodizing on the inner and outer surfaces of the parts to improve the corrosion resistance of the parts.

Claims

1. A method for processing aluminum alloy complex cylinder parts of a helicopter rotor system damper, characterized in that: include: For the machining allowance distribution of the forging blank, the alignment reference is transferred from the forging blank to the standard base plate of the alignment reference, and the forging blank is clamped on the standard base plate equipped with the alignment reference; Process the alignment datum so that the processed alignment datum becomes the positioning datum for rough processing; Rough-machine the center inner hole of the forging blank according to the positioning reference of rough machining; Adopt special mandrel clamping and rough machining mandrel, rough machining the fork and positioning hole of the blank; Install the rough-machined forging blank positioning hole and the rough-machined positioning reference with the special lathe tooling, and finish the center inner hole; Special mandrel clamping and finishing mandrel are used to finish the fork and drilling of forging blanks.

2. The processing method according to claim 1, characterized in that: The method further comprises: Threaded holes, honing, dimension inspection, fluorescent flaw detection, anodizing.

3. The processing method according to claim 1, characterized in that: For the machining allowance distribution of the forging blank, the alignment reference is transferred from the forging blank to the standard base plate of the alignment reference. The forging blank is clamped on the standard base plate equipped with the alignment reference, including: Use laser scanning or visual recognition to check the machining allowance of the forging blank to ensure that the minimum radial machining allowance is not less than 0.2mm; then clamp the forging blank on a standard base plate equipped with an alignment datum, and use laser scanning again to determine the positional relationship between the forging blank and the alignment datum.

4. The processing method according to claim 3, characterized in that: Machining alignment benchmark, including: The machining and alignment are carried out according to the positional relationship between the forging blank and the alignment datum, and the positioning datum for rough machining is produced.

5. The processing method according to claim 4, characterized in that: According to the positioning reference of rough machining, the center inner hole of the forging blank is rough machined, including: Rough machined parts center hole size d0 +0.03 Dimensional accuracy, roughness R a 3.2, Process the end face of the hole, ensure that the end face is perpendicular to the axis of the center hole to 0.005mm, and leave a processing allowance of 1mm at each place after processing; At the same time, the processing of the axial positioning plane is completed.

6. The processing method according to claim 5, characterized in that: Special mandrel clamping includes: center positioning mandrel, clamping mechanism, heightened base, axial positioning device; The center positioning mandrel is a rough machining mandrel or a fine machining mandrel; the center positioning mandrel is installed on the heightened base, the forging blank is sleeved on the center positioning mandrel through its own rough machining center hole, and the clamping mechanism presses the lower end surface of the forging blank on the heightened base; the axial positioning device is installed on the heightened base, and cooperates with the rough machining positioning reference to realize axial positioning; Adopt special mandrel clamping and rough machining mandrel, rough machining workpiece blank fork, set positioning hole, including: The fork shape is rough-machined using a special spindle clamp suitable for a five-axis CNC milling machine, leaving a 1mm machining allowance after rough machining; positioning holes are made at the radial holes of the forging blank, and the positioning holes must ensure dimensional accuracy H9 and roughness R a 1.

6.

7. The processing method according to claim 6, characterized in that: Special lathe tooling includes: transfer plate, counterweight, clamping mechanism, clamping body, locating pin, center height adjustment mechanism, and directional pin; One end of the clamp body is connected to the CNC lathe spindle interface through an adapter plate, and a counterweight is also installed; a center height adjustment mechanism is arranged on the upper end surface of the other end of the clamp body, and a positioning pin and a directional pin are arranged on the center height adjustment mechanism. The forging blank is horizontally placed on the center height adjustment mechanism, and the positioning pin and the directional pin are both positioned in cooperation with the rough-machined positioning holes; a clamping mechanism is installed on the clamp body, and is used to clamp the forging blank on the center height adjustment mechanism; The rough-machined forging blank positioning hole and the rough-machined positioning reference are installed in conjunction with the special lathe tooling to fine-machine the center inner hole, including: Using a special lathe tooling, the part is clamped on the spindle of the CNC lathe, and the center hole of the part is finely machined to a size of D0. +0.03 , after finishing, leave 0.05mm honing allowance to ensure the roughness R a 16.

8. The processing method according to claim 7, characterized in that: Use special mandrel clamping and finishing mandrel to finish the fork and drilling of forging blanks, including: Use a special mandrel clamp suitable for a five-axis CNC milling machine to complete the fine machining of the fork mouth contour and bushing hole in one positioning: When machining the bushing installation hole at the fork mouth, the machining should be completed from one side of the fork mouth in one time. The center positioning mandrel and the center hole size D +0.03 0.03~0.05mm; At the same time, before drilling hydraulic holes in various places, it is necessary to complete the fine processing of the hole positioning surface first, then use the center drill to make the guide hole, and finally use a special carbide step drill to complete the processing of the step hole and the hole chamfer in one go.

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