RU2498883C1 - Method of making compressor blade - Google Patents

Abstract

FIELD: process engineering.SUBSTANCE: invention relates to machine building and may be used for producing gas turbine blades. Proposed method comprises milling of blade body at five-access NC machine. Translation and periodic feed are imparted to cutter to scan line in blade blank along blade blank axis in the form of parallelepiped to be turned relative to the cutter. Blank is clamped in appropriate appliance at the machine horizontal table vertically relative to said table. Cutter is brought to initial contact with blade surface for milling the blade butt and pre-milling of blade elements located in compressor wheel space in at least five passes with the help of cylindrical end and peripheral parts. Then, blank is located vertically relative to machine horizontal table to remove machining riser. Blank is cut to shape blade butt or butt with extra structural elements with the help of taper mill in at least one pass at cutter axis deviation from perpendicular to cutter feed direction and in the plane perpendicular thereto with the help of taper and cylindrical mill in at least two passes in milling the blade with extra structural elements.EFFECT: simple and fast production.4 cl, 1 tbl, 8 dwg

Description

The invention relates to the field of engineering, in particular the production of gas turbine engine blades.

The production of blades occupies a special place in aircraft engine manufacturing, which is caused by a number of factors, the main of which are:

complex geometric shape of the feather and shank of the blades; manufacturing accuracy; the need to use expensive specialized equipment; high complexity of manufacturing.

Increased requirements for manufacturing accuracy, the quality of the compressor blades have identified the need to improve production processes.

A known method of manufacturing compressor blades (RF Patent No. 2132266, class B23P 15/02; B21D 53/78, published 06/27/1999), in which, basing the blade blank directly on the pen, they process the surfaces of the technological bases on the shank, then installing and fixing the blade on the surface of the shank, the feather of the scapula is treated.

A disadvantage of the known method is the low productivity of manufacturing a compressor blade, which consists in the complexity of its manufacture due to the need to base the shank by pouring the pen with low-melting material, and a low-melting capsule is formed, which is then removed. The workpiece is obtained by stamping.

Known methods for processing compressor blades of turbojet engines (Monthly industrial magazine for professionals and managers "Metalworking and machine tools", April 2010, No. 4, p. 18, turning and milling "Features of the processing technology of compressor blades of turbojet engines"; December 2009, No. 12 , p. 18, “Features of the processing technology of compressor blades of turbojet engines”). The blades are machined on a five-axis CNC machine.

The disadvantages of this method are:

- the need to use as a blank stamping with a finished machined lock blades;

- the traditional horizontal position of the workpiece during processing, in which the workpiece is attached to the fixture in the locking part and is pressed by the stop from the end of the pen;

- the presence in the design of a device for fastening the workpiece of the rear pressing center causes the technological complexity of basing (installation) and fixing the workpieces of the compressor blades, a consequence of the structural and technological complexity of basing and fixing the workpiece of the compressor blades is a reduced accuracy of milling; difficulty in basing requires a large number of intermediate operations for basing and fastening the workpiece of the compressor blade during milling.

Known for the closest to the technological nature and the achieved result is a method of manufacturing a compressor blade (Patent No. 2225985, class B23Q 3/00 B23C 3/18; published June 10, 2008), including milling a pen on a multi-axis numerically controlled machine (CNC), with in which the rotating cutter is informed of the movement and periodic feeding of a line along the axis of the blade blank, which is rotated relative to the cutter, on the horizontal table of the machine there is a device for installing, fixing and milling compress GOVERNMENTAL blades, the blade blank is clamped in this device, then in accordance with the control program installed cutter is fed to the initial point of contact with the treated surface of the blade and perform cutting, milling is performed at this peripheral portion of the cutter.

A significant drawback of this method is the inability to fully implement the process, starting from the stage of processing the workpiece to the finished part, as well as the use of specially designed devices for installing (basing) and securing the workpieces clutter the space of the working area of the machine.

The technical result achieved in the claimed invention is the creation of a high-tech method that provides increased productivity for the manufacture of compressor blades on a five-axis CNC machine, by simplifying the technology and reducing the complexity of manufacturing.

In contrast to the traditional horizontal and inclined position of the compressor blade, a more technologically advanced vertical orientation of the compressor blade workpiece relative to the horizontal table of the machine is proposed, due to the use of the shape of the workpiece in the form of a parallelepiped, which greatly simplifies installation (basing), fastening and is achieved through the use of a simple clamp design fixtures. Milling of the compressor blades is carried out using a five-axis CNC machine, which significantly reduces the manufacturing time of the compressor blades, since the time of reconfiguration of the machine is eliminated.

The technical result is achieved by the fact that the method of manufacturing a compressor blade includes milling a pen on a five-coordinate numerically controlled machine tool (CNC), in which the rotating cutter is informed of the movement and periodic feeding of a line along the axis of the blade workpiece, which is rotated relative to the cutter, on a horizontal table of the machine place a device for installing, securing and milling compressor blades, clamp the blade blank in this device, then in accordance In accordance with the installed control program, the milling cutter is brought to the initial point of contact with the blade surface to be machined and milling is performed, while milling is performed by the peripheral part of the milling cutter.

New in the method is that the preform is preformed in the form of a parallelepiped, then the preform of the compressor blade is fixed vertically relative to the horizontal table of the five-axis CNC machine, for which the preform is installed in the fixture clamp, the blank of the blade is processed by milling to give the finished shape of the shank and preliminary milling of the blade elements located in the flow part of the compressor for at least five transitions using a cylindrical cutter, with fr The milling is carried out with the end and peripheral parts of the milling cutter, then the workpiece is base vertically relative to the horizontal table of the machine along the surface of the shank, the technological profit is removed, the workpiece is milled to give the finished form of a pen or feather with additional structural element (s) of the blade using conical milling cutter for at least one transition in case the blade feather is machined, while the milling axis is deviated from the normal to the workpiece in the direction plane odachi cutter and a plane perpendicular to it and using the cone and the cylindrical cutter with at least two transitions in case of the blade structure comprises a further (an) constructive (an) element (s).

The developed method allows milling compressor blades, the length of which is from 20 to 100 mm.

To facilitate basing the workpiece in the form of a parallelepiped can be made with a protrusion.

The design of the compressor blades may contain additional structural elements in the form of anti-vibration shelves or second shank.

The accompanying drawings show:

figure 1 - the design of the compressor blades with an additional structural element in the form of anti-vibration shelves;

figure 2 - the design of the compressor blades with an additional structural element in the form of an additional shank;

figure 3-diagram of the interaction of the cutter with the workpiece of the compressor blades with vertical fastening;

figure 4 - volumetric model of the workpiece of the compressor blades in the form of a parallelepiped with a protrusion;

5 is a three-dimensional model of the workpiece of the compressor blades in the device before processing;

6 is a three-dimensional model of the workpiece of the compressor blades in the device after milling the shank and pre-milling the pen;

7 is a three-dimensional model of the workpiece of the compressor blades after milling the shank and pre-milling the pen;

Fig - external view of the compressor blades manufactured by the proposed method.

The proposed method is implemented as follows.

Processing compressor blades (Fig.1, 2) is carried out on a five-coordinate CNC machine.

An electronic three-dimensional model of the blade, billet (figure 4) and tooling is being developed. A cutting and auxiliary tool is selected, a control program for the CNC machine tool is developed, and computer verification for the absence of collisions of the moving parts of the machine and the cutting tool with the tooling and the workpiece using special programs.

On the horizontal table 1 (figure 5) of the machine place the device 2 (figure 5) for installation (basing) and fixing the workpiece 3 (figure 4, 5) of the compressor blade.

For processing the workpiece 3 (figure 4) of the compressor blade in the form of a parallelepiped is fixed vertically relative to the horizontal table of the machine 1 (figure 5). For this, the workpiece 3 (Fig. 5) of the compressor blade is installed in the clamp 4 (Fig. 5) of the device 2 (Fig. 5), providing a normalized pressing force.

Then, in accordance with the developed control program, the cylindrical cutter is brought to the initial point of contact with the workpiece surface 3 and milling is carried out to give the finished shape of the shank 5 (Fig.6, 7), as well as preliminary milling of the blade elements (Fig.1, 2), located in the flow part of the compressor (feather blades 6 (1, 2) and flow surface 7 (1, 2) of the shank 5 (1, 2)). In this case, a cylindrical mill is used, milling is carried out by the end and peripheral part of the mill in at least five transitions.

The vertical position of the workpiece 3 of the compressor blade allows the milling of the shank 5 with the elements of the blade located in the flow part of the compressor 6, 7 (Fig.7), in one installation.

Then turn the workpiece 3, base on the machined surface of the shank 5, remove the technological profit 8 (Fig.7).

Process the workpiece 3 (Fig.7) by milling to give the finished shape of the pen 6 or pen with additional structural elements of the scapula (Fig.1, 2). If the design of the blade consists of a feather 6 and a shank 5, then the feather 6 is processed using a conical cutter 9 (Fig.3) at least in one transition, while in accordance with the developed control program, the conical cutter 9 (Fig.3) is brought to the initial point of contact with the pen 6, and the axis of the cutter 10 (Fig.3) is deviated from the normal 11 (Fig.3) to the surface to be machined in the plane 12 (Fig.3) of the feed direction of the cutter 9 (Fig.3) and in the plane perpendicular to it 13 (FIG. 3). Then, the rotary milling cutter 9 (Fig. 3) reports the movement across the axis 14 (Fig. 3) of the pen 6 and the periodic feeding on line 15 (Fig. 3) along the axis 14 (Fig. 3) of the workpiece 3 (Fig. 3) of the blade, which rotate relative to the cutter 9 (figure 3).

If the design of the blade consists of a pen 6, a shank 5 and additional (s) structural (s) element (s) (Figs. 1, 2), the processing is carried out by a cone (as described above) and a cylindrical cutter in at least six transitions. Milling is carried out by the peripheral part of the cutter.

An example implementation of the method.

Processing of the compressor blade (without additional structural elements) was carried out at the milling 5-axis machining center Hermle C30U (Germany). A workpiece (material alloy EI787) in the form of a parallelepiped 15X35X48 with a protrusion 3X35X13 to facilitate basing. The workpiece is installed (based) in the fixture.

The stages of processing the workpiece are presented in table 1.

Table 1. Transition Content Time min Cutting tool one Pre-shank milling 5.5 Cylindrical mill 2 Shank sole milling 2.6 Cylindrical mill 3 Mowing bevels (“swallow”) of the shank finally 0.9 Cylindrical mill four Shank end milling 0.6 Cylindrical mill 5 Milling of a flowing part previously 19.7 Cylindrical mill 6 Half flow milling 5.65 Cylindrical mill 7 Removing technological profits at the end of the pen 5 Cylindrical mill 8 Half radius milling 3.2 Cone milling cutter 9 Milling the profile part finally 22.6 Cone milling cutter 10 Final milling radius mating 4.25 Cone milling cutter

The pre-milling time is 34.95 minutes.

The final milling time is 30.05 minutes.

The time for removing technological profits is 5 minutes.

The total machine time for processing one blade was 70 minutes.

After performing the final milling (Fig. 8), the roughness parameters of the flow part and the shank of the blade were measured. Analysis of the measurement results indicates that as a result of milling, the requirements of the design documentation for the accuracy of the profile and lock parts have been achieved. The roughness of the pen is Ra 0.34-0.64 μm, the roughness of the bevels of the shank Ra 0.37 μm.

The developed manufacturing method is simple and technological efficient. Technological tests have confirmed that:

- the method improves the dimensional accuracy and surface cleanliness of the treated compressor blade profile;

- allows you to significantly reduce the complexity of manufacturing a compressor blade by eliminating intermediate operations, including grinding the blade and subsequent manual fine-tuning, and thereby significantly reduce the amount of marriage during manufacture.

- the method allows for high-performance milling of the compressor blades with little time for installation (basing) and clamping the workpiece.

Claims (4)

1. A method of manufacturing compressor blades, including milling a feather of a blade on a five-coordinate numerically controlled machine (CNC), in which a rotating cutter is informed of movement and periodic feeding along a line along the axis of the blade blank, which is rotated relative to the cutter, the blade blank is clamped in a horizontal position the table of the machine, a device for installing, fixing and milling compressor blades, then, in accordance with the established control program, the cutter is brought to a similar point of contact with the blade surface to be machined and milling is carried out, characterized in that the preform is preformed in the form of a parallelepiped, which is fixed in the fixture clamp vertically relative to the horizontal table of the five-coordinate CNC machine, and milling is carried out to give the shank shape and preliminary milling of the blade elements, located in the flow part of the compressor, at least five transitions using a cylindrical cutter, with fr The milling is carried out with the end and peripheral parts of the milling cutter, then the workpiece is based vertically relative to the horizontal table of the machine along the surface of the shank, the technological profit is removed, the workpiece is machined with the pen or pen with additional structural elements of the blade using the conical milling cutter for at least one transition during processing a blade pen with a milling axis deviation from the normal to the work surface in the plane of the cutter feed direction and in the plane perpendicular to it and or using a conical and cylindrical milling cutter for at least two transitions when processing the blades with additional structural elements. 2. The method according to claim 1, characterized in that it is intended for the manufacture of compressor blades, the length of which is from 20 to 100 mm 3. The method according to claim 1, characterized in that the blank of the compressor blade is made with an additional protrusion. 4. The method according to claim 1, characterized in that the additional structural element of the blade is an anti-vibration shelf or a second shank.

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