Machining method for throat plugging pin holes between high-pressure turbine prewhirl nozzle blades

Abstract

The invention discloses a method for machining a throat plugging pin hole between pre-swirl nozzle blades of a high-pressure turbine. The method comprises the following steps: aligning the center of a part; measuring the point coordinates of the highest points of the two trailing edges of the two adjacent blades on the same cross section; calculating a machining axial reference; calculating the deflection angles of the highest points of the two trailing edges relative to the Y axis of the part center; calculating a machining angular reference; relevant dimension parameters and a spiral hole milling mode are used as feature elements to be programmed into a machining program; and a machining program is started until machining of the plug pin hole is completed. According to the method, the machining benchmark of each throat plug pin hole can be accurately determined, then the machining position of each throat plug pin hole is determined, the problems of repeated testing and adjustment machining caused by large blade casting fluctuation and large blade profile position difference are solved, one-time accurate positioning machining of each throat plug pin hole can be achieved, and the machining efficiency is improved. The problems of dependence on experience of operators, high processing risk and high out-of-tolerance risk are avoided, a spiral hole milling mode is adopted to replace a traditional drilling-chambering-reaming mode, and the processing efficiency of the plug pin hole is greatly improved.

Description

Technical Field

[0001] The invention belongs to the technical field of manufacturing parts of aviation engines, and in particular relates to a method for machining throat plugging pin holes between blades of a high-pressure turbine pre-swirl nozzle. Background Art

[0002] Taking a certain type of aircraft engine as an example, the flow channel position of its high-pressure turbine pre-swirl nozzle includes 60 blades. When checking the air flow in the throat between the blades, if the flow is greater than the upper limit of the required value, it is necessary to process a plugging pin hole at the throat position between two adjacent blades. By welding a plugging pin in the plugging pin hole, the throat can be blocked, thereby adjusting the flow.

[0003] However, when processing the plugging pin hole, the trailing edge of the blade is required to be used as the reference, and it is not allowed to penetrate the blade, and the processing positions of the two adjacent blades must be fully exposed to light. Because there is a large fluctuation between the actual casting position of the 60 blades and the theoretical design position, and the deviation degree of the actual casting position of the blade from the theoretical design position is also inconsistent and irregular.

[0004] At present, the traditional method of processing plugging pin holes is usually: first roughly align the positions of the trailing edges of two adjacent blades, then perform bottom hole processing of the plugging pin holes, then visually observe the degree of deviation of the bottom hole, and then expand the bottom hole through repeated tests and adjustment of the processing position until the processing of the plugging pin holes is completed.

[0005] However, the traditional pin hole processing method has the disadvantages of low processing efficiency, high reliance on operator experience, high processing risk and high risk of out-of-tolerance. Summary of the invention

[0006] In view of the problems existing in the prior art, the present invention provides a method for processing throat plugging pin holes between blades of a high-pressure turbine pre-swirl nozzle, which can accurately determine the processing datum of each throat plugging pin hole, and then determine its processing position, avoiding the problems of repeated trials and adjustments in processing caused by large casting fluctuations and large differences in blade shape positions of 60 blades, and can achieve one-time precise positioning processing of each throat plugging pin hole, avoiding the problems of relying on operator experience, high processing risks, and high risks of out-of-tolerance. The spiral milling method replaces the traditional drilling-expansion-reaming method, which greatly improves the processing efficiency of the plugging pin holes. Taking the processing of 12 plugging pin holes as an example, the processing time is reduced from about 31 hours to about 18 hours, and the processing efficiency is improved by about 41%. At the same time, the processing qualification rate can be improved to 100%.

[0007] In order to achieve the above object, the present invention adopts the following technical solution: a method for machining a throat plugging hole between blades of a high-pressure turbine pre-swirl nozzle, comprising the following steps:

[0008] Step 1: Clamp the part onto the machine tool and complete the part center alignment;

[0009] Step 2: Use a machine tool probe to measure the coordinates of the two highest points of the trailing edges of two adjacent blades on the same section, mark the coordinates of the first highest point of the trailing edge as (X1, Y1, Z1), and mark the coordinates of the second highest point of the trailing edge as (X2, Y2, Z2);

[0010] Step 3: Calculate the machining axial reference, and record the machining axial reference as Z0. The calculation formula is:

[0011] Z0=(Z1+Z2) / 2

[0012] Wherein, Z1 is the Z-axis coordinate value of the highest point of the first trailing edge, and Z2 is the Z-axis coordinate value of the highest point of the second trailing edge;

[0013] Step 4: Calculate the deflection angles of the highest points of the two trailing edges relative to the Y axis where the center of the part is located. The deflection angle of the highest point of the first trailing edge is recorded as C1, and the deflection angle of the highest point of the second trailing edge is recorded as C2. The calculation formula is:

[0014] C1=-tan -1 (|Y1 / X1|)

[0015] C2=-tan -1 (∣Y2 / X2∣)

[0016] Wherein, X1 is the X-coordinate value of the highest point of the first trailing edge, Y1 is the Y-coordinate value of the highest point of the first trailing edge, X2 is the X-coordinate value of the highest point of the second trailing edge, and Y2 is the Y-coordinate value of the highest point of the first trailing edge;

[0017] Step 5: Calculate the processing angle reference, and record the processing angle reference as C0. The calculation formula is:

[0018] C0=(C1+C2) / 2

[0019] Where C1 is the deflection angle of the highest point of the first trailing edge, and C2 is the deflection angle of the highest point of the second trailing edge;

[0020] Step 6: Map the calculated machining axial reference Z0 and machining angular reference C0 to the machine tool machining coordinate system;

[0021] Step 7: The diameter of the plugging pin hole is recorded as φB, the process angle between the center of the plugging pin hole and the line connecting the highest points of the two trailing edges is recorded as A, the vertical distance between the center of the plugging pin hole and the line connecting the highest points of the two trailing edges is recorded as H, the distance from the bottom surface of the plugging pin hole to the center of the part is recorded as L1, and the distance from the highest point of the plugging pin hole to the center of the part is recorded as L2. The above-mentioned size parameters and spiral milling method are compiled into the processing program as feature elements;

[0022] Step 8: Start the processing program until the processing of the plugging pin hole is completed.

[0023] Beneficial effects of the present invention:

[0024] The method for processing throat plugging pin holes between blades of a high-pressure turbine pre-swirl nozzle of the present invention can accurately determine the processing benchmark of each throat plugging pin hole, and then determine its processing position, avoiding the problem of repeated trials and adjustments caused by large casting fluctuations of 60 blades and large differences in blade position, and can achieve one-time precise positioning processing of each throat plugging pin hole, avoiding the problems of relying on operator experience, high processing risks, and high risk of out-of-tolerance. The spiral milling method replaces the traditional drilling-expansion-reaming method, which greatly improves the processing efficiency of the plugging pin holes. Taking the processing of 12 plugging pin holes as an example, the processing time is reduced from about 31 hours to about 18 hours, and the processing efficiency is improved by about 41%. At the same time, the processing qualification rate can be improved to 100%. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a schematic diagram of the radial dimensions of the plugging pin hole;

[0026] Figure 2 for Figure 1 Middle II sectional view;

[0027] Figure 3 It is a schematic diagram of the blade axial position coordinates; DETAILED DESCRIPTION

[0028] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0029] A method for machining a throat plugging pin hole between blades of a high-pressure turbine pre-swirl nozzle comprises the following steps:

[0030] Step 1: Figures 1 to 3 The parts shown are clamped on the machine tool to complete the part center alignment;

[0031] Step 2: Use a machine tool probe to measure the coordinates of the two highest points of the trailing edges of two adjacent blades on the same section, mark the coordinates of the first highest point of the trailing edge as (X1, Y1, Z1), and mark the coordinates of the second highest point of the trailing edge as (X2, Y2, Z2);

[0032] Step 3: Calculate the machining axial reference, and record the machining axial reference as Z0. The calculation formula is:

[0033] Z0=(Z1+Z2) / 2

[0034] Wherein, Z1 is the Z-axis coordinate value of the highest point of the first trailing edge, and Z2 is the Z-axis coordinate value of the highest point of the second trailing edge;

[0035] Step 4: Calculate the deflection angles of the highest points of the two trailing edges relative to the Y axis where the center of the part is located. The deflection angle of the highest point of the first trailing edge is recorded as C1, and the deflection angle of the highest point of the second trailing edge is recorded as C2. The calculation formula is:

[0036] C1=-tan -1 (|Y1 / X1|)

[0037] C2=-tan -1 (∣Y2 / X2∣)

[0038] Wherein, X1 is the X-coordinate value of the highest point of the first trailing edge, Y1 is the Y-coordinate value of the highest point of the first trailing edge, X2 is the X-coordinate value of the highest point of the second trailing edge, and Y2 is the Y-coordinate value of the highest point of the first trailing edge;

[0039] Step 5: Calculate the processing angle reference, and record the processing angle reference as C0. The calculation formula is:

[0040] C0=(C1+C2) / 2

[0041] Where C1 is the deflection angle of the highest point of the first trailing edge, and C2 is the deflection angle of the highest point of the second trailing edge;

[0042] Step 6: Map the calculated machining axial reference Z0 and machining angular reference C0 to the machine tool machining coordinate system;

[0043] Step 7: The diameter of the plugging pin hole is recorded as φB, the process angle between the center of the plugging pin hole and the line connecting the highest points of the two trailing edges is recorded as A, the vertical distance between the center of the plugging pin hole and the line connecting the highest points of the two trailing edges is recorded as H, the distance from the bottom surface of the plugging pin hole to the center of the part is recorded as L1, and the distance from the highest point of the plugging pin hole to the center of the part is recorded as L2. The above-mentioned size parameters and spiral milling method are compiled into the processing program as feature elements;

[0044] Step 8: Start the processing program until the processing of the plugging pin hole is completed.

[0045] The solutions in the embodiments are not intended to limit the protection scope of the present invention. All equivalent implementations or changes that do not deviate from the present invention are included in the protection scope of the present invention.

Claims

1. A method for machining a throat plugging hole between blades of a high-pressure turbine pre-swirl nozzle, characterized in that: The steps include: Step 1: Clamp the part onto the machine tool and complete the part center alignment; Step 2: Use a machine tool probe to measure the coordinates of the two highest points of the trailing edges of two adjacent blades on the same section, mark the coordinates of the first highest point of the trailing edge as (X1, Y1, Z1), and mark the coordinates of the second highest point of the trailing edge as (X2, Y2, Z2); Step 3: Calculate the machining axial reference, and record the machining axial reference as Z0. The calculation formula is: Z0=(Z1+Z2) / 2 Wherein, Z1 is the Z-axis coordinate value of the highest point of the first trailing edge, and Z2 is the Z-axis coordinate value of the highest point of the second trailing edge; Step 4: Calculate the deflection angles of the highest points of the two trailing edges relative to the Y axis where the center of the part is located. The deflection angle of the highest point of the first trailing edge is recorded as C1, and the deflection angle of the highest point of the second trailing edge is recorded as C2. The calculation formula is: C1=-tan -1 (∣Y1 / X1∣) C2=-tan -1 (∣Y2 / X2∣) Wherein, X1 is the X-coordinate value of the highest point of the first trailing edge, Y1 is the Y-coordinate value of the highest point of the first trailing edge, X2 is the X-coordinate value of the highest point of the second trailing edge, and Y2 is the Y-coordinate value of the highest point of the first trailing edge; Step 5: Calculate the processing angle reference, and record the processing angle reference as C0. The calculation formula is: C0=(C1+C2) / 2 Where C1 is the deflection angle of the highest point of the first trailing edge, and C2 is the deflection angle of the highest point of the second trailing edge; Step 6: Map the calculated machining axial reference Z0 and machining angular reference C0 to the machine tool machining coordinate system; Step 7: The diameter of the plugging pin hole is recorded as φB, the process angle between the center of the plugging pin hole and the line connecting the highest points of the two trailing edges is recorded as A, the vertical distance between the center of the plugging pin hole and the line connecting the highest points of the two trailing edges is recorded as H, the distance from the bottom surface of the plugging pin hole to the center of the part is recorded as L1, and the distance from the highest point of the plugging pin hole to the center of the part is recorded as L2. The above-mentioned size parameters and spiral milling method are compiled into the processing program as feature elements; Step 8: Start the processing program until the processing of the plugging pin hole is completed.

Images