Fixture and processing method for improving the milling accuracy of blade profile of large fan rotor blades

Abstract

A fixture and processing method for improving the milling accuracy of blade profiles of large fan rotor blades include a cylinder and a bushing installed in the cylinder, an adjusting screw is installed at one end of the cylinder, and the bottom end of the adjusting screw is connected to one end of the bushing, and the radial position of the bushing is adjusted by rotating the adjusting screw, and the other end of the bushing is sleeved on the fixture disc of the fixture connection part, and the positioning block of the fixture connection part is installed with a fixture part by screws, and a pressure cover is installed at one end of the cylinder by screws, and the other end is connected to the machine tool connection tray by a transfer connection part. This technology uses two-end process tables for positioning, adopts a new blade processing sequence, and uses flexible floating fixtures for flexible clamping during the blade clamping process, which avoids processing deformation caused by weak rigidity of the blade structure, and relies on CNC programs and high-precision CNC processing equipment to ensure the geometric accuracy of blade body milling, so that the geometric accuracy of the blade body profile after processing meets the design requirements.

Description

Technical Field

[0001] The invention belongs to the technical field of aeroengines, and in particular relates to a fixture and a processing method for improving the milling accuracy of blade profiles of large fan rotor blades. Background Art

[0002] The blades of large fan rotors are long and weak in rigidity. There is a damping boss on the middle basin and the back side of the blade. Figure 1 As shown in the figure. The original milling process of the blade profile is from the small end blade profile to the transition between the blade profile and the tenon, that is, the small end of the blade profile is processed first, then the damping platform, then the large end blade body, and finally the transition between the blade profile and the tenon. Since the rigidity of the blade is gradually weakened during the processing, and the blade body is long and the blade profile is thin, it is easy to deform during the processing, which makes it difficult to ensure the geometric accuracy of the blade profile.

[0003] This technology uses a different processing sequence from the original blade processing sequence, that is, the damping table is processed first, then the blade small end, then the blade large end, and finally the blade and tenon transition. At the same time, the processing sequence from the damping table to the blade tip and the tenon side is adopted in the blade processing of the small end and the large end, respectively. The blade clamping rigidity is always maintained during the processing, and the floating flexible clamping is used at the blade tip to avoid clamping deformation, which ultimately reduces the milling deformation of the blade and ensures the geometric accuracy of the blade after milling. Summary of the invention

[0004] The purpose of the present invention is to provide a fixture and a processing method for improving the milling accuracy of large fan rotor blades. By adopting a new blade processing sequence and using a floating device for flexible clamping during the blade clamping process, the milling deformation of the blade is reduced, the milling geometric accuracy of the blade body surface is guaranteed, and the processing quality and pass rate of the blade are improved.

[0005] In order to achieve the above object, the present invention adopts the following technical solution:

[0006] A method for improving the milling processing accuracy of blade profiles of large fan rotor blades, using a fixture for improving the milling processing accuracy of blade profiles of large fan rotor blades, the fixture for improving the milling processing accuracy of blade profiles of large fan rotor blades comprising a cylinder and a bushing installed in the cylinder, an adjusting screw is installed at one end of the cylinder, and the bottom end of the adjusting screw is connected to one end of the bushing, and the radial position of the bushing is adjusted by rotating the adjusting screw, the other end of the bushing is sleeved on a clamp disc of a clamp connection part, a positioning block of the clamp connection part is installed with a clamp part by screws, a pressure cover is installed at one end of the cylinder by screws, and the other end is connected to a machine tool connection tray by a transfer connection part;

[0007] The clamp part includes a clamp positioning block, a raised portion at one end of the upper surface of the clamp positioning block is hingedly connected to one end of the clamp pressing block, a U-shaped groove is provided at the other end of the clamp pressing block, a stud is installed at the other end of the upper surface of the clamp positioning block, the top end of the stud cooperates with the U-shaped groove of the clamp pressing block and is fixed by a nut, and an adjustable clamp pressing block is installed on the lower surface of the clamp pressing block;

[0008] The adjustable clamp clamp block is composed of a V-shaped clamp block and a connecting column. The connecting column is installed on the top of the V-shaped clamp block. A blind hole for installing the connecting column is opened on the lower surface of the clamp clamp block. At the same time, an adjusting bolt vertically arranged with the blind hole is installed on the clamp clamp block. By loosening the adjusting bolt, the position of the V-shaped clamp block can be rotated in the circumferential direction. After adjustment, the position of the V-shaped clamp block is fixed by tightening the adjusting bolt.

[0009] The upper surface of the fixture positioning block is symmetrically provided with bosses for blade positioning;

[0010] The method for improving the milling accuracy of blade profiles of large fan rotor blades comprises the following steps:

[0011] Step 1: The blade is clamped on both ends of the process table for blade body surface milling

[0012] When clamping the blade, the process table at the blade tip adopts a flexible floating clamping method and is clamped by a flexible floating fixture. That is, during the clamping process, the clamping of the blade tip process table can be adjusted according to the actual position of the blade tip process table to avoid clamping stress.

[0013] Step 2: When milling the blade surface, the damping platform is processed first. Since both the small-end blade and the large-end blade have margins, the stability of the clamping can be guaranteed during the processing to avoid processing deformation.

[0014] Step 3: Milling the small end blade surface

[0015] The processing sequence is: processing from the damping platform to the blade tip. By using a flexible floating fixture, the stability of the clamping can be fully maintained during the processing to avoid processing deformation caused by weakening of the clamping rigidity.

[0016] Step 4: Milling the large blade surface

[0017] The processing sequence is: processing from the damping platform to the lateral blade profile and the tenon transition point. By using a flexible floating fixture, the stability of the clamping can be fully maintained during the processing to avoid processing deformation caused by weakening of the clamping rigidity;

[0018] Step 5: Finally, mill the joint between the blade and the tenon to complete the processing.

[0019] The technical effects of the present invention are:

[0020] This technology uses process tables at both ends for positioning. It adopts a new blade processing sequence and uses flexible floating fixtures for flexible clamping during the blade clamping process to avoid processing deformation caused by weak blade structure rigidity. The geometric accuracy of blade milling is guaranteed by CNC programs and high-precision CNC processing equipment, so that the geometric accuracy of the blade surface after processing meets the design requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 A partial cross-sectional schematic diagram of a fixture for improving the milling accuracy of blade profiles of large fan rotor blades according to the present invention;

[0022] Figure 2 A side view of a fixture for improving the milling accuracy of blade profiles of large fan rotor blades according to the present invention;

[0023] Figure 3 A schematic diagram of a fixture for improving the milling accuracy of blade profiles of large fan rotor blades according to the present invention;

[0024] Figure 4 A front view of the connecting portion of the clamp of the present invention;

[0025] Figure 5 A top view of the connecting portion of the clamp of the present invention;

[0026] Figure 6 A schematic diagram of the structure of a large fan rotor blade of the present invention;

[0027] Figure 7 Schematic diagram of the processing sequence of the small end blade of the present invention;

[0028] 1-machine tool connecting tray, 2-adapter connecting part, 3-cylinder, 4-bushing, 5-adjusting screw, 6-clamp clamping block, 7-clamp positioning block, 8-V-type clamping block, 9-connecting column, 10-adjusting bolt, 11-boss, 12-clamp disc, 13-positioning block, 14-pressure cover, 15-stud, 16-adjustable clamp clamping block, 17-clamp connecting part. DETAILED DESCRIPTION

[0029] The present invention is further described in detail below in conjunction with the accompanying drawings and embodiments.

[0030] like Figures 1 to 5As shown, a fixture for improving the milling accuracy of blade profiles of large fan rotor blades comprises a cylinder 3 and a bushing 4 installed in the cylinder 3, the inner diameter of the cylinder 3 is larger than the outer diameter of the bushing 4, an adjusting screw 5 is installed at one end of the cylinder 3, and the bottom end of the adjusting screw 5 is connected to one end of the bushing 4, and the radial position of the bushing 4 is adjusted by rotating the adjusting screw 5 to realize flexible floating clamping of the process table at the tip of the blade, the other end of the bushing 4 is sleeved on the clamp disk 12 of the clamp connection part 17, the positioning block 13 of the clamp connection part 17 is installed with a clamp part by screws, a pressure cover 14 is installed at one end of the cylinder 3 by screws, and the other end is connected to the machine tool connection tray 1 through the adapter connection part 2.

[0031] The clamp part includes a clamp positioning block 7, a raised part at one end of the upper surface of the clamp positioning block 7 is hingedly connected to one end of the clamp clamping block 6, a U-shaped groove is provided at the other end of the clamp clamping block 6, a stud 15 is installed at the other end of the upper surface of the clamp positioning block 7, the top end of the stud 15 cooperates with the U-shaped groove of the clamp clamping block 6 and is fixed by a nut, and an adjustable clamp clamping block 16 is installed on the lower surface of the clamp clamping block 6.

[0032] The adjustable clamp clamping block 16 is composed of a V-shaped clamping block 8 and a connecting column 9. The connecting column 9 is integrally formed on the top of the V-shaped clamping block 8. A blind hole for installing the connecting column 9 is opened on the lower surface of the clamp clamping block 6. At the same time, an adjusting bolt 10 vertically arranged with the blind hole is installed on the clamp clamping block 6. By loosening the adjusting bolt 10, the position of the V-shaped clamping block 8 can be rotated in the circumferential direction. After adjustment, the position of the V-shaped clamping block 8 is fixed by tightening the adjusting bolt 10.

[0033] The upper surface of the fixture positioning block 7 is symmetrically provided with bosses 11 for blade positioning.

[0034] like Figure 6 and Figure 7 As shown, a method for improving the milling accuracy of blade profiles of large fan rotor blades, using the fixture for improving the milling accuracy of blade profiles of large fan rotor blades, comprises the following steps:

[0035] Step 1: The blade is clamped on both ends of the process table for blade body surface milling

[0036] When the blade is clamped, the process table at the blade tip adopts a flexible floating clamping method, that is, the process table at the blade tip is positioned by the boss 11 on the fixture positioning block 7, and then the fixture clamping block 6 is turned over to cooperate with the stud 15 on the fixture positioning block 7, and the adjusting bolt 10 is loosened to rotate the position of the adjustable fixture clamping block 16 circumferentially, and finally the nut on the stud 15 is rotated to press the process table at the blade tip through the adjustable fixture clamping block 16, and at the same time, the radial position of the bushing 4 can be adjusted by loosening the adjusting screw 5, that is, the clamping of the blade tip process table during the clamping process can be adjusted according to the actual position of the blade tip process table to avoid clamping stress;

[0037] Step 2: When milling the blade surface, the damping platform is processed first. Since both the small-end blade and the large-end blade have margins, the stability of the clamping can be guaranteed during the processing to avoid processing deformation.

[0038] Step 3: Milling the small end blade surface

[0039] The processing sequence is: processing from the damping platform to the blade tip. By using the fixture, the stability of the clamping can be fully maintained during the processing to avoid processing deformation caused by weakening of the clamping rigidity.

[0040] Step 4: Milling the large blade surface

[0041] The processing sequence is: processing from the damping platform to the lateral blade profile and the tenon transition point. By using the fixture during the processing, the stability of the clamping can be fully maintained to avoid processing deformation due to weakening of the clamping rigidity;

[0042] Step 5: Finally, mill the joint between the blade and the tenon to complete the processing.

Claims

1. A method for improving the milling accuracy of blade profiles of large fan rotor blades, using a fixture for improving the milling accuracy of blade profiles of large fan rotor blades, characterized in that: The fixture for improving the milling processing accuracy of blade profiles of large fan rotor blades comprises a cylinder and a bushing installed in the cylinder, an adjusting screw is installed at one end of the cylinder, and the bottom end of the adjusting screw is connected to one end of the bushing, and the radial position of the bushing is adjusted by rotating the adjusting screw, and the other end of the bushing is sleeved on the fixture disc of the fixture connection part, and the positioning block of the fixture connection part is installed with a fixture part by screws, a gland is installed at one end of the cylinder by screws, and the other end is connected to the machine tool connection tray by a transfer connection part; The clamp part includes a clamp positioning block, a raised portion at one end of the upper surface of the clamp positioning block is hingedly connected to one end of the clamp pressing block, a U-shaped groove is provided at the other end of the clamp pressing block, a stud is installed at the other end of the upper surface of the clamp positioning block, the top end of the stud cooperates with the U-shaped groove of the clamp pressing block and is fixed by a nut, and an adjustable clamp pressing block is installed on the lower surface of the clamp pressing block; The adjustable clamp clamp block is composed of a V-shaped clamp block and a connecting column. The connecting column is installed on the top of the V-shaped clamp block. A blind hole for installing the connecting column is opened on the lower surface of the clamp clamp block. At the same time, an adjusting bolt vertically arranged with the blind hole is installed on the clamp clamp block. By loosening the adjusting bolt, the position of the V-shaped clamp block can be rotated in the circumferential direction. After adjustment, the position of the V-shaped clamp block is fixed by tightening the adjusting bolt. The upper surface of the fixture positioning block is symmetrically provided with bosses for blade positioning; The method for improving the milling accuracy of blade profiles of large fan rotor blades comprises the following steps: Step 1: The blade is clamped on both ends of the process table for blade body surface milling When clamping the blade, the process table at the blade tip adopts a flexible floating clamping method and is clamped by a flexible floating fixture. That is, during the clamping process, the clamping of the blade tip process table can be adjusted according to the actual position of the blade tip process table to avoid clamping stress. Step 2: When milling the blade surface, the damping platform is processed first. Since both the small-end blade and the large-end blade have margins, the stability of the clamping can be guaranteed during the processing to avoid processing deformation. Step 3: Milling the small end blade surface The processing sequence is: processing from the damping platform to the blade tip. By using a flexible floating fixture, the stability of the clamping can be fully maintained during the processing to avoid processing deformation caused by weakening of the clamping rigidity. Step 4: Milling the large blade surface The processing sequence is: processing from the damping platform to the lateral blade profile and the tenon transition point. By using a flexible floating fixture, the stability of the clamping can be fully maintained during the processing to avoid processing deformation caused by weakening of the clamping rigidity; Step 5: Finally, mill the joint between the blade and the tenon to complete the processing.

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