A method of removing braze and base material from a vane inner cavity of a guider

Abstract

A processing method for removing filler metal and base material in the inner cavity of a vane of a guider, according to the shape of the vane, the vane adhesion fault area is divided into five small areas, numbered as fault 1 area to fault 5 area respectively; wherein the fault 1 area is at the position of the split joint of the trailing edge of the vane tip; the fault 2 area is at the position of the transition area of the vane tip fillet and the inner cavity of the vane; the fault 3 area is the cold gas cavity area of the vane; the fault 4 area is the back side area of the vane; the fault 5 area is the side area of the vane basin; and the electrodes are designed for the above five areas respectively, and the electrodes are numbered, and the designed electrodes are used to remove the excess base material and filler metal by electric spark processing. In the present application, the fault area division method is used, and the processing electrodes are designed for each fault area respectively, and the designed electrodes are used to remove the excess base material and filler metal by electric spark processing, so that the quality problem of the filler metal sticking the guide vane and the vane during the brazing process of the guide vane is solved.

Description

Technical Field

[0001] This invention relates to the field of aero-engine manufacturing technology, and in particular to a processing method for removing brazing filler metal and substrate from the inner cavity of a guide vane. Background Technology

[0002] In the manufacturing of low-pressure turbine guide vanes for aero-engines, due to the high brazing temperature and long brazing time, and the good flow properties of the molten brazing filler metal, a defective situation easily occurs where the brazing filler metal adheres to the guide vanes assembled inside the blade cavity and the blade itself. This prevents the cool air from reaching the blade body during operation, thus failing to generate a cooling effect, and the blade is easily burned through. Therefore, if this problem occurs, the part is scrapped directly, resulting in serious economic losses. To salvage the low-pressure turbine guide vane that is brazed to the blade cavity, it is necessary to remove the brazed guide vane and part of the base material, and then re-braze it. Summary of the Invention

[0003] The main objective of this invention is to provide a processing method for removing the brazing filler metal and substrate from the inner cavity of the guide vane, thereby solving the aforementioned technical problems.

[0004] To achieve the above objectives, this invention proposes a processing method for removing the brazing filler metal and substrate from the inner cavity of a guide vane. Based on the vane shape, the adhesion fault area is decomposed into five smaller areas, numbered Fault Area 1 to Fault Area 5 respectively; wherein:

[0005] Fault area 1 is located at the slit at the tip and trailing edge of the blade;

[0006] Fault area 2 is located at the transition zone between the blade tip radius and the blade inner cavity;

[0007] Fault zone 3 is the blade cooling chamber area;

[0008] Fault zone 4 is the area on the back side of the blade;

[0009] Fault zone 5 is the area on the blade's leaf base side;

[0010] Electrodes were designed and processed for the five regions mentioned above, and the electrodes were numbered. The designed electrodes were then used to remove excess substrate and solder through electrical discharge machining.

[0011] Preferably, when designing and processing the electrode, a discharge gap of 1.0 mm is left on the electrode.

[0012] Preferably, the EDM process for fault zone 2 is divided into two steps: roughing and finishing. Therefore, two electrodes are designed for fault zone 2, including a roughing electrode and a finishing electrode. First, the roughing electrode is used to remove most of the brazing filler metal and guide plate mixture from fault zone 2. Then, the finishing electrode is used to finish fault zone 2, with each step being 5mm deep.

[0013] Preferably, when performing electrical discharge machining on fault zone 1, it is required that the flow column inside the blade and the transverse rib of the blade cooling chamber are not damaged.

[0014] Preferably, when processing fault zone 4, the transverse ribs of the cooling air cavity on the back side of the blade are processed to eliminate the brazing filler metal in fault zone 4.

[0015] Preferably, when processing fault zone 5, the transverse ribs of the cooling air cavity on the blade blade basin side are processed to eliminate the brazing filler metal in fault zone 5.

[0016] Preferably, the parameters for electrical discharge machining are: discharge intensity 5A; breakdown voltage 200V; pulse width 80μs; ​​pulse interval 25μs.

[0017] Preferably, after the electrical discharge machining is completed, it is observed that the adhesion area of ​​the blade has been completely cleared. If the adhesion area has been completely cleared, the oxide layer on the blade surface needs to be polished before the guide vanes can be assembled.

[0018] Preferably, during the electrical discharge machining process using the same electrode, the same electrode is clamped only once and the corresponding fault area is machined.

[0019] Preferably, during the electrical discharge machining process, after each electrode change, it is necessary to check whether the guide parts are in their original positions.

[0020] Due to the adoption of the above technical solution, the beneficial effects of the present invention are as follows:

[0021] In this invention, the blade adhesion fault area is divided into five smaller areas by utilizing the fault area division method, and an electrode is designed and processed for each fault area. The designed electrode is then used to remove excess substrate and brazing filler metal by electrical discharge machining, which solves the quality problem of brazing filler metal sticking the guide plate to the blade during the brazing process of the guide blade. This method breaks through the technical blind spot that manual grinding cannot remove brazing adhesion in the narrow blade space. This method has strong promotion and application value. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0023] Figure 1 A schematic diagram of the brazing adhesion fault area of ​​the guide vane;

[0024] Figure 2 This is a schematic diagram of the corresponding zones for the electrodes;

[0025] Figure 3 Schematic diagram of guide and electrode clamping;

[0026] Figure 4 Three-view diagrams for electrode 0010-1# or 0010-2#;

[0027] Figure 5 Three-view diagram of electrode 0010-3#;

[0028] Figure 6 Three-view diagram of electrode 0010-4#;

[0029] Figure 7 Three-view drawing of electrode 0010-5#

[0030] Figure 8 The three-view diagram of electrode 0010-6#. Detailed Implementation

[0031] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0032] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0033] Combination Figure 1 A processing method for removing solder and substrate from the inner cavity of a guide vane, wherein, based on the vane shape, the vane adhesion fault area is decomposed into five smaller areas, numbered as fault area 1 to fault area 5 respectively; wherein:

[0034] Fault area 1 is located at the slit at the tip and trailing edge of the blade;

[0035] Fault area 2 is located at the transition zone between the blade tip radius and the blade inner cavity;

[0036] Fault zone 3 is the blade cooling chamber area;

[0037] Fault zone 4 is the area on the back side of the blade;

[0038] Fault zone 5 is the area on the blade's leaf base side;

[0039] Combination Figure 2 As shown, electrodes were designed and processed for the five areas mentioned above, with a 1.0 mm discharge gap between the electrodes. The electrodes were numbered, and excess substrate and solder were removed using electrical discharge machining (EDM) on the designed electrodes.

[0040] Combination Figure 3 As shown, considering that the blade neck is the narrowest part of the entire trailing edge slit, and that the blade vector changes with the blade shape, the part clamping is quite difficult. After measuring the part model and the actual object, the final clamping was carried out according to... Figure 3 The guide parts and electrodes are arranged as shown. Specifically, the guide parts are placed on the worktable, and an electrode holder is installed at the lower end of the machine tool spindle. The electrode is installed on the electrode holder through the end chuck, and the electrode is in a horizontal state to perform electrical discharge machining on the guide blades.

[0041] Combination Figures 4 to 8 As shown, in this embodiment, a total of six electrodes were designed, numbered 0010-1#, 0010-2#, 0010-3#, 0010-4#, 0010-5# and 0010-6# respectively.

[0042] Electrodes 0010-1# and 0010-2# are designed according to the shape of the transition zone between the blade tip radius and the blade inner cavity, i.e., according to the shape of fault zone 2. Electrodes 0010-1# and 0010-2# are similar in shape, differing only in the size of their profiles. Electrode 0010-1# is the roughing electrode, and electrode 0010-2# is the finishing electrode. Therefore, when machining fault zone 2, the 0010-1# roughing electrode is first used to remove most of the brazing filler metal and guide vane mixture from fault zone 2. Then, the 0010-2# finishing electrode is used to finish fault zone 2, with each finishing step being 5mm deep. After roughing and finishing with electrodes 0010-1# and 0010-2# respectively, the narrowest point between the blade trailing edge slit and the blade inner cavity can be penetrated, paving the way for subsequent machining of other fault areas.

[0043] Electrode 0010-3# is designed according to the blade tip and trailing edge slit shape and is used to process fault zone 1. When performing EDM on fault zone 1, it is required that the internal flow column and the transverse rib of the blade cooling chamber be avoided. The purpose of machining with electrode 0010-3# is to remove excess substrate, solder, and guide vane adhesion in fault zone 1 (i.e., the blade tip and trailing edge slit). During EDM, the machining feed direction is adjusted according to the blade vector.

[0044] Electrode 0010-4# is designed according to the shape of the blade's cooling chamber, but it does not have transverse ribs and is used for rough machining of fault zone 3. The purpose of machining electrode 0010-4# is to remove most of the solder and guide vane adhesion in fault zone 3 of the blade's cooling chamber. Machining fault zone 3 aims to increase the space, facilitating subsequent machining of the transverse ribs in the blade's cooling chamber.

[0045] Electrode 0010-5# is also designed according to the shape of the blade's cooling air cavity. Additionally, transverse ribs are provided on the blade back side of electrode 0010-5# for finishing fault zone 4, and for machining the transverse ribs of the cooling air cavity on the blade back side to eliminate brazing filler metal in fault zone 4. During machining, machining is performed according to the blade back direction vector.

[0046] Electrode 0010-6# is designed according to the shape of the blade's blade base side and is used to process fault zone 5, while also machining the transverse ribs of the cooling air cavity on the blade's blade base side. During machining, it is performed according to the blade's blade base direction vector.

[0047] In this embodiment, the parameters for electrical discharge machining are: discharge intensity 5A; breakdown voltage 200V; pulse width 80μs; ​​pulse interval 25μs.

[0048] Throughout the entire electrical discharge machining (EDM) process, when using the same electrode, it is only clamped once to complete the machining of the corresponding fault area, avoiding errors caused by repeated clamping. After each electrode change, it is necessary to check whether the guide component is in its original position to prevent component movement during machining.

[0049] Since the transverse ribs of the blade cooling chamber are designed to guide the airflow evenly through the blade for cooling, the electrode machining depth must be strictly controlled and measured during the manufacturing process to avoid exceeding the design requirements and resulting in excessive cooling.

[0050] After the electrical discharge machining is completed, observe whether the adhesion area of ​​the blade has been completely cleared. If the adhesion area has been completely cleared, the oxide layer on the blade surface needs to be polished before the guide vanes can be assembled.

[0051] The above description is merely a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention's specification and drawings under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A processing method for removing brazing filler metal and substrate from the inner cavity of a guide vane, characterized in that, Based on the blade shape, the blade adhesion fault area is divided into five smaller areas, numbered from Fault Zone 1 to Fault Zone 5; among which: Fault area 1 is located at the slit at the tip and trailing edge of the blade; Fault area 2 is located at the transition zone between the blade tip radius and the blade inner cavity; Fault zone 3 is the blade cooling chamber area; Fault zone 4 is the area on the back side of the blade; Fault zone 5 is the area on the blade's leaf base side; Electrodes were designed and processed for the five regions mentioned above, and the electrodes were numbered. Excess substrate and solder were removed by electrical discharge machining using the designed electrodes. Two electrodes are designed for fault area 2, including a roughing electrode and a finishing electrode. The roughing electrode and the finishing electrode are similar in shape but different in size. When performing EDM on fault area 2, it is divided into two steps: roughing and finishing. First, the roughing electrode is used to remove most of the brazing filler metal and guide vane mixture in fault area 2. Then, the finishing electrode is used to finish fault area 2, with each step being 5mm deep. The goal is to penetrate the narrowest position between the blade trailing edge slit and the blade inner cavity, thus creating a path for subsequent machining of other fault areas. When performing electrical discharge machining on fault zone 1, it is required that the internal flow column and the transverse rib of the blade cooling chamber be not damaged. The machining feed direction should be adjusted according to the blade vector during electrical discharge machining. An electrode was designed for fault zone 3. This electrode does not have transverse ribs and is used for rough machining to remove most of the brazing filler metal and guide vane adhesion in the blade cooling chamber of fault zone 3, thereby expanding the space and facilitating subsequent machining of the transverse ribs of the blade cooling chamber. Electrodes were designed for fault zone 4. When machining fault zone 4, the transverse ribs of the cooling air cavity on the back side of the blade were machined to remove the brazing filler metal in fault zone 4, and the machining was carried out according to the blade back direction vector. Electrodes were designed for fault zone 5. When machining fault zone 5, the transverse ribs of the cooling air cavity on the blade blade basin side were machined to remove the brazing filler metal in fault zone 5, and the machining was carried out according to the blade blade basin direction vector. During the processing, the electrode processing depth is strictly controlled and measured to avoid exceeding the design requirements and causing excessive cooling.

2. The processing method for removing the brazing filler metal and substrate from the inner cavity of the guide vane as described in claim 1, characterized in that: When designing and processing the electrodes, a discharge gap of 1.0 mm is left on the electrodes.

3. The processing method for removing the brazing filler metal and substrate from the inner cavity of a guide vane as described in claim 1, characterized in that, The parameters for electrical discharge machining are: discharge intensity 5A; breakdown voltage 200V; pulse width 80μs; ​​pulse interval 25μs.

4. The processing method for removing the brazing filler metal and substrate from the inner cavity of the guide vane as described in claim 1, characterized in that: After the electrical discharge machining is completed, observe whether the adhesion area of ​​the blade has been completely cleared. If the adhesion area has been completely cleared, the oxide layer on the blade surface needs to be polished before the guide vanes can be assembled.

5. The processing method for removing the brazing filler metal and substrate from the inner cavity of a guide vane as described in claim 1, characterized in that: During electrical discharge machining using the same electrode, the same electrode is clamped only once and the corresponding fault area is machined.

6. The processing method for removing the brazing filler metal and substrate from the inner cavity of the guide vane as described in claim 1, characterized in that: During electrical discharge machining, after each electrode change, it is necessary to check whether the guide parts are in their original positions.

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