CN114289808B - Electric spark machining method for special-shaped air film holes of turbine blades - Google Patents
Electric spark machining method for special-shaped air film holes of turbine blades Download PDFInfo
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- CN114289808B CN114289808B CN202210085510.8A CN202210085510A CN114289808B CN 114289808 B CN114289808 B CN 114289808B CN 202210085510 A CN202210085510 A CN 202210085510A CN 114289808 B CN114289808 B CN 114289808B
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- 238000003754 machining Methods 0.000 title claims abstract description 65
- 238000000034 method Methods 0.000 title claims abstract description 40
- 238000010892 electric spark Methods 0.000 title claims abstract description 30
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 claims abstract description 63
- 229910052802 copper Inorganic materials 0.000 claims abstract description 63
- 239000010949 copper Substances 0.000 claims abstract description 63
- 230000008569 process Effects 0.000 claims description 15
- 238000005530 etching Methods 0.000 claims description 6
- 239000008367 deionised water Substances 0.000 claims description 5
- 229910021641 deionized water Inorganic materials 0.000 claims description 5
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 5
- 239000012530 fluid Substances 0.000 claims description 4
- 230000007246 mechanism Effects 0.000 claims description 4
- 238000003672 processing method Methods 0.000 claims description 4
- 239000012224 working solution Substances 0.000 claims description 4
- 230000000149 penetrating effect Effects 0.000 claims description 3
- 230000000750 progressive effect Effects 0.000 claims description 3
- 239000000463 material Substances 0.000 description 5
- 239000000243 solution Substances 0.000 description 3
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 2
- 238000011010 flushing procedure Methods 0.000 description 2
- 238000003801 milling Methods 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 239000012720 thermal barrier coating Substances 0.000 description 2
- 239000000956 alloy Substances 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 238000005452 bending Methods 0.000 description 1
- 229910017052 cobalt Inorganic materials 0.000 description 1
- 239000010941 cobalt Substances 0.000 description 1
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 238000005553 drilling Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000017525 heat dissipation Effects 0.000 description 1
- 230000001788 irregular Effects 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 229910052759 nickel Inorganic materials 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
- 230000003746 surface roughness Effects 0.000 description 1
Abstract
According to the electric spark machining method for the special-shaped air film holes of the turbine blade, the numerical control electric spark small hole machine is used for carrying out distributed electric spark machining on the air film holes on the turbine blade, and the numerical control electric spark small hole machine is used for carrying out electric discharge machining by adopting the thin copper pipe electrode wire.
Description
Technical Field
The invention belongs to the technical field of electric spark machining of special-shaped holes, and particularly relates to an electric spark machining method of a turbine blade special-shaped air film hole.
Background
The performance of aeroengines and gas turbines is primarily dependent on the material properties of the guide blades and turbine blades, the surface thermal barrier coating and the film coverage of the film holes. Wherein the shape of the profiled film holes is changed to increase the pre-turbine temperature by about 40% weight. Therefore, the shape of the air film hole of the blade is changed from a round hole to a round hole and a special-shaped outlet, and the surface of the blade is better covered. The hot end blade material is nickel base, cobalt base and the like, and the micropore and the special-shaped hole cannot be machined. With the rise of the temperature before the turbine, the requirements on materials and thermal barrier coatings are improved, the heat dissipation requirement of the special-shaped air film hole is improved, and the requirements on special-shaped shapes and positions are comprehensively improved.
At present, a common domestic machining method is that firstly, an electric spark small hole machine is used for machining holes, and then an electric spark forming machine is used for machining dustpan holes. Two kinds of equipment are clamped and checked twice, and repeated alignment is difficult. The electric spark forms the electrode, and the electrode loss is generated in the processing process. Secondly, a laser processing method is used, P seconds of laser processing is high in efficiency, but a remelting layer is thicker, and holes are irregular; the femtosecond laser processing has low efficiency and high cost; two laser devices are needed for laser processing, one laser device is used for laser drilling, the other laser device is used for processing special-shaped, the similar devices are clamped twice, and a precise zero point positioning tool is needed.
Therefore, it is necessary to design an electric spark machining method for the special-shaped air film holes of the turbine blade to solve the technical problems.
It should be noted that the foregoing description of the background art is only for the purpose of providing a clear and complete description of the technical solution of the present invention and is presented for the convenience of understanding by those skilled in the art. The above-described solutions are not considered to be known to the person skilled in the art simply because they are set forth in the background of the invention section.
Disclosure of Invention
In order to overcome the defects in the prior art, the invention aims to provide an electric spark machining method for a special-shaped air film hole of a turbine blade.
To achieve the above and other related objects, the present invention provides the following technical solutions: the electric spark machining method for the special-shaped air film holes of the turbine blades adopts a numerical control electric spark small hole machine to carry out distributed electric spark machining on the air film holes on the turbine blades, the numerical control electric spark small hole machine adopts a thin copper pipe electrode wire to carry out electric spark machining, and the thin copper pipe electrode wire is controlled to move by a moving device; the processing method comprises the following steps:
Step 1: firstly, carrying out electric discharge machining on a cylindrical hole with a regular shape at the lower half part of the special-shaped air film hole by adopting a copper pipe electrode wire;
Step 2: then, the copper pipe electrode wire is adopted to process the irregular-shaped air film hole at the upper half part of the special-shaped air film hole, the processing mode is that the thin copper pipe electrode wire is driven by the moving device to perform electric discharge processing around the bottom of the air film hole from circle to circle, and then the electric discharge processing is performed in a progressive mode from circle to circle and upwards; and the real-time loss of the thin copper pipe electrode wire during the processing of the previous layer is determined before the processing of each layer.
Preferably, in the step 2, before processing each layer, the etching volume on the workpiece during processing the layer needs to be determined according to the original processing track of the special-shaped air film hole, and then the etching volume on the workpiece and the real-time loss generated during processing the previous layer of the thin copper pipe electrode wire are analyzed, so as to determine the actual electric discharge processing track of the thin copper pipe electrode wire.
Preferably, the actual electric discharge machining track of the thin copper pipe electrode wire comprises the actual cutting angle and the machining depth of the thin copper pipe electrode wire in the machining process, and the actual electric discharge machining track is controlled by a moving device.
Preferably, the thin copper pipe electrode wire is a hollow copper pipe, and a working fluid channel penetrating up and down is formed in the thin copper pipe electrode wire.
Preferably, the processing mode is a workpiece immersed processing mode or a workpiece flushing processing mode, and deionized water working solution is adopted in the processing process.
Preferably, the moving device is specifically a servo feeding device with a plurality of shafts, and the shafts of the servo feeding device are at least five shafts.
Preferably, the thin copper pipe electrode wire is required to be clamped and positioned by a copper pipe supporting mechanism in the electric discharge machining process.
Preferably, in the above processing, the pulse power supply parameter needs to be adjusted, so as to reduce the single pulse energy and increase the discharge frequency in unit time.
Preferably, in the above processing, all feeding shafts of the servo feeding device need to perform servo feeding and retracting according to the discharge gap state in the processing, and after one processing is completed, all feeding shafts need to be separated from the workpiece in time and return in the original path.
Preferably, in the processing process, the thin copper pipe electrode wire and the workpiece are required to rotate, and the electric brush is used for supplying power.
Due to the application of the technical scheme, compared with the prior art, the invention has the following advantages:
According to the electric spark machining method for the special-shaped air film holes of the turbine blade, a simple electric spark copper pipe electrode wire is utilized to replace a cutter, the cutter cannot machine the special-shaped holes in materials, the special-shaped air film holes in the high-temperature alloy blade are milled at a high speed according to machining tracks, the machining of the special-shaped air film holes of the whole turbine blade is completed only by one-time clamping, the machining efficiency is high, the actual machining tracks are determined again by analyzing the real-time loss of the electrode wire during machining, and therefore machining precision is effectively improved.
Drawings
FIG. 1 is a schematic view of a profiled film hole.
Fig. 2 is a schematic view of the processing of a fine copper tube wire electrode.
In the above figures, a workpiece 1, a thin copper pipe electrode wire 2 and a working fluid channel 3.
Detailed Description
Further advantages and effects of the present invention will become apparent to those skilled in the art from the disclosure of the present invention, which is described by the following specific examples.
Please refer to fig. 1-2. It should be noted that, in the description of the present invention, it should be noted that, directions or positional relationships indicated by terms such as "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., are directions or positional relationships based on those shown in the drawings, or directions or positional relationships in which the inventive product is conventionally put in use, are merely for convenience of describing the present invention and for simplifying the description, and are not indicative or implying that the apparatus or element to be referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be construed as limiting the present invention. Furthermore, the terms "first," "second," "third," and the like are used merely to distinguish between descriptions and should not be construed as indicating or implying relative importance. The terms "horizontal," "vertical," "overhang," and the like do not denote that the component is required to be absolutely horizontal or overhang, but may be slightly inclined. As "horizontal" merely means that its direction is more horizontal than "vertical", and does not mean that the structure must be perfectly horizontal, but may be slightly inclined.
In the description of the present invention, it should also be noted that, unless explicitly specified and limited otherwise, the terms "disposed," "mounted," "connected," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, integrally connected, mechanically connected, electrically connected, directly connected, indirectly connected through an intermediary, or communicating between two elements. The specific meaning of the above terms in the present invention will be understood in specific cases by those of ordinary skill in the art.
Examples: as shown in fig. 1, in the electric spark machining method for the special-shaped gas film holes of the turbine blade, a numerical control electric spark small hole machine is adopted to carry out distributed electric spark machining on the gas film holes on the turbine blade, the numerical control electric spark small hole machine adopts a thin copper pipe electrode wire to carry out electric spark machining, a workpiece is connected with a positive electrode, the copper pipe electrode wire is connected with a negative electrode, and the thin copper pipe electrode wire is controlled to move by a moving device; the processing method comprises the following steps:
Step 1: firstly, carrying out electric discharge machining on a cylindrical hole with a regular shape at the lower half part of the special-shaped air film hole by adopting a copper pipe electrode wire;
Step 2: then, the copper pipe electrode wire is adopted to process the irregular-shaped air film hole at the upper half part of the special-shaped air film hole, the processing mode is that the thin copper pipe electrode wire is driven by the moving device to perform electric discharge processing around the bottom of the air film hole from circle to circle, and then the electric discharge processing is performed in a progressive mode from circle to circle and upwards; meanwhile, before each layer is processed, the real-time loss amount of the thin copper pipe electrode wire generated in the process of processing the previous layer is required to be determined; the etching volume on the workpiece is determined by the original machining track of the special-shaped air film hole, then the etching volume on the workpiece and the real-time loss amount generated by the thin copper pipe electrode wire in the previous layer machining process are analyzed, so that the actual electric discharge machining track of the thin copper pipe electrode wire is determined, the actual electric discharge machining track comprises the actual cutting angle and the machining depth of the thin copper pipe electrode wire in the machining process, and then the movement of the copper pipe electrode wire is controlled by a moving device in the machining process.
As shown in figure 2, the thin copper pipe electrode wire 2 is a hollow copper pipe, the inside of the thin copper pipe electrode wire is provided with a working fluid channel 3 penetrating through the upper part and the lower part, and the thin copper pipe electrode wire is a copper pipe electrode with the thickness of 0.2-0.8 mm.
The workpiece immersing type or workpiece flushing type processing mode is adopted, deionized water working solution is adopted in the processing process, the working solution is directly sprayed on the processing surface of the workpiece through a channel formed in the electrode wire, and the processing surface of the workpiece 1 is required to be completely immersed in the deionized water; and the center of the copper pipe is punched with 10MPa of high pressure liquid to assist chip removal.
The moving device can be a servo feeding device with a plurality of shafts, the shafts of the servo feeding device are at least five, and the motor wire is driven to move and feed through a plurality of shafts.
The thin copper pipe electrode wire is required to be clamped and positioned by a copper pipe supporting mechanism in the process of electric discharge machining; as the thin copper pipe electrode wire is only 0.2-0.8mm, the whole thin copper pipe electrode wire is thin and soft, a clamping mechanism is needed during processing, and the conditions of shaking, bending and the like of the thin copper pipe electrode wire are avoided, so that the processing precision is influenced.
In the machining process, pulse power parameters are required to be regulated, single pulse energy is reduced, the discharge frequency in unit time is increased, the pulse power is an important component part of electric spark small hole machining equipment, machining precision and machining surface quality are directly affected, in small hole machining, small pulse width and large peak current technologies are required to be researched, single pulse energy is reduced, the discharge frequency in unit time is increased, the remelting layer thickness and microcrack of machining materials are reduced, and machining precision is improved; the three-dimensional electric discharge machining process of the copper pipe electrode wire in the machining process has the following technical indexes:
(1) Minimum discharge milling electrode 0.2mm;
(2) Minimum milling aperture 0.25mm;
(3) The surface roughness Ra0.8um of electric discharge machining;
(4) The thickness of the remelting layer on the surface of the electric discharge machining is less than or equal to 0.02mm;
(5) The consistency of the processing size of the special-shaped holes is less than or equal to +/-0.05 mm;
(6) The processing depth-to-diameter ratio of the special-shaped holes is more than 30:1
In the machining process, all feeding shafts of the servo feeding device need to carry out servo feeding and rollback according to the discharge gap state in the machining process, and after one-time machining is finished, all the feeding shafts need to be separated from a workpiece in time and return in an original path; different from cutting processing, short circuit is unavoidable between copper pipe electrodes and workpieces in the processing process due to factors such as servo feeding speed and chip removal, and once the electrodes and the workpieces are subjected to short circuit processing, servo feeding and rollback are required to be carried out on all feeding shafts according to the state of a processing discharge gap, the electrodes must be separated from the workpieces in time, and XYZ interpolation original paths return to ensure the processing precision of the special-shaped hole patterns.
In the processing process, the thin copper pipe electrode wire and the workpiece are required to rotate, and the electric brush is used for supplying power; the electrode rotating main shaft is provided with an adjustable speed alternating current servo motor of 100-1500RPM; the ER collet chuck is used for clamping the main shaft, so that the copper pipe is ensured to concentrically rotate; the workpiece is clamped by adopting a zero tool, so that the guide vane can be machined at multiple angles.
The above embodiments are merely illustrative of the principles of the present invention and its effectiveness, and are not intended to limit the invention. Modifications and variations may be made to the above-described embodiments by those skilled in the art without departing from the spirit and scope of the invention. Accordingly, it is intended that all equivalent modifications and variations of the invention be covered by the claims, which are within the ordinary skill of the art, be within the spirit and scope of the present disclosure.
Claims (8)
1. The electric spark machining method for the special-shaped air film holes of the turbine blades is characterized by comprising the following steps of: carrying out distributed electric spark machining on the air film holes on the turbine blades by adopting a numerical control electric spark small hole machine, wherein the numerical control electric spark small hole machine adopts a thin copper pipe electrode wire for electric discharge machining, and the thin copper pipe electrode wire is controlled to move by a moving device; the processing method comprises the following steps:
Step 1: firstly, carrying out electric discharge machining on a cylindrical hole with a regular shape at the lower half part of the special-shaped air film hole by adopting a copper pipe electrode wire;
step 2: then, the copper pipe electrode wire is adopted to process the irregular-shaped air film hole at the upper half part of the special-shaped air film hole, the processing mode is that the thin copper pipe electrode wire is driven by the moving device to perform electric discharge processing around the bottom of the air film hole from circle to circle, and then the electric discharge processing is performed in a progressive mode from circle to circle and upwards; meanwhile, before each layer is processed, the real-time loss amount of the thin copper pipe electrode wire generated in the process of processing the previous layer is required to be determined; before processing each layer, determining the etching volume on a workpiece when the layer is processed according to the original processing track of the special-shaped air film hole, and then analyzing the etching volume on the workpiece and the real-time loss amount generated when the thin copper pipe electrode wire is processed on the previous layer so as to determine the actual electric discharge processing track of the thin copper pipe electrode wire;
The processing mode is that the workpiece is immersed, deionized water working solution is adopted in the processing process, and the processing surface of the workpiece is required to be completely immersed in the deionized water.
2. The method for electrosparking the special-shaped air film holes of the turbine blade according to claim 1, wherein the method comprises the following steps of: the actual electric discharge machining track of the thin copper pipe electrode wire comprises the actual cutting-in angle and the machining depth of the thin copper pipe electrode wire in the machining process, and the thin copper pipe electrode wire is controlled through a moving device.
3. The method for electrosparking the special-shaped air film holes of the turbine blade according to claim 1, wherein the method comprises the following steps of: the thin copper pipe electrode wire is a hollow copper pipe, and a working fluid channel penetrating up and down is formed in the thin copper pipe electrode wire.
4. The method for electrosparking the special-shaped air film holes of the turbine blade according to claim 1, wherein the method comprises the following steps of: the moving device is specifically a servo feeding device with a plurality of shafts, and the shafts of the servo feeding device are at least five shafts.
5. The method for electrosparking the special-shaped air film holes of the turbine blade according to claim 1, wherein the method comprises the following steps of: the thin copper pipe electrode wire is required to be clamped and positioned by using a copper pipe supporting mechanism in the electric discharge machining process.
6. The method for electrosparking the special-shaped air film holes of the turbine blade according to claim 1, wherein the method comprises the following steps of: in the processing process, the pulse power supply parameters are required to be adjusted, the single pulse energy is reduced, and the discharge frequency in unit time is increased.
7. The method for electrosparking the special-shaped air film holes of the turbine blade according to claim 4, wherein the method comprises the following steps of: in the machining process, all the feed shafts of the servo feeding device need to carry out servo feeding and rollback according to the discharge gap state in the machining process, and after one-time machining is completed, all the feed shafts need to be separated from the workpiece in time and return in an original way.
8. The method for electrosparking the special-shaped air film holes of the turbine blade according to claim 1, wherein the method comprises the following steps of: in the processing process, the thin copper pipe electrode wire and the workpiece are required to rotate, and the electric brush is used for supplying power.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210085510.8A CN114289808B (en) | 2022-01-25 | Electric spark machining method for special-shaped air film holes of turbine blades |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210085510.8A CN114289808B (en) | 2022-01-25 | Electric spark machining method for special-shaped air film holes of turbine blades |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN114289808A CN114289808A (en) | 2022-04-08 |
| CN114289808B true CN114289808B (en) | 2024-06-25 |
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Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102861956A (en) * | 2012-09-20 | 2013-01-09 | 清华大学 | Machining method of gravity-free smelting layer air membrane hole of aviation engine turbine blade |
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102861956A (en) * | 2012-09-20 | 2013-01-09 | 清华大学 | Machining method of gravity-free smelting layer air membrane hole of aviation engine turbine blade |
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