A method for positioning a radial reference of an intermediate casing of an aeroengine based on a blank

Abstract

A kind of based on blank's aero-engine intermediate casing radial reference positioning method, based on blank feature, by mathematical modeling, the actual coordinates of two reference holes are taken as known quantity, the actual coordinate value of radial reference is obtained;When part alignment, let part one pin hole be in X axis positive direction, according to part structure, then another pin hole must be in second quadrant, then the actual coordinates of two pin holes can be automatically measured by machine tool online measurement function, the actual coordinate value of radial reference is obtained by using global variable function to call two reference hole coordinates, and finally the automatic positioning of radial reference is completed;In processing, the radial reference of part is determined by aligning the rotary circle.The advantages of the present application are: the problem of unable to process due to special part structure is solved.It can be applied to all parts processing with one-face-two-pin method to determine reference, instead of traditional mechanical alignment method, so that the reference positioning and processing of this type of blank are no longer limited by special fixtures.

Description

Technical Field

[0001] This invention relates to the field of workpiece positioning, and in particular to a radial reference positioning method for an aero-engine intermediate casing based on a blank. Background Technology

[0002] The datum for the intermediate casing in the research and development process is determined by the "one-face, two-pin" structure of the cast blank. Before machining, the blank has no rotational circle for aligning the radial datum. The existing positioning solution for this type of part in China involves designing a special fixture, aligning the pin hole of the part with the pin of the fixture, and using the aligning band of the fixture to determine the radial datum. However, due to the part's weight of approximately 80 kg, the limited space at the pin hole, and the small diameter of the pin hole, specifically… The structure at the clamp pin cannot support the weight of the part, rendering the clamp unusable. Consequently, the radial reference of the part cannot be determined, and part machining cannot begin. Summary of the Invention

[0003] The purpose of this invention is to address the shortcomings of existing technologies by developing a machining technology that effectively positions the radial reference of a research and development intermediate casing based on blank characteristics without the need for special fixtures. This solves the problem that the part cannot be machined because the radial reference cannot be positioned. Specifically, this invention provides a method for positioning the radial reference of an aero-engine intermediate casing based on a blank.

[0004] This invention provides a radial reference positioning method for an aero-engine intermediate casing based on a blank, characterized in that: before machining the intermediate casing parts, the blank has no rotational circle for aligning the radial reference; the parts are heavy, approximately 80 kg; the space at the pin hole is narrow; and the pin hole diameter is small.

[0005] The two reference holes are located 272 mm from the theoretical radial reference, and the angle between the line connecting the two reference holes and the radial reference is 135°.

[0006] (1) In order to determine the actual position of the radial reference, based on the blank features, the actual coordinates of the two reference holes are taken as known quantities through mathematical modeling, and the actual coordinate values ​​of the radial reference are obtained through calculation.

[0007] (2) In order to determine the approximate position of the reference hole of the part so that the positioning technology can be effectively implemented in production, by arranging the process, when the part is aligned, one pin hole of the part is located in the positive direction of the X axis. According to the part structure, the other pin hole must be located in the second quadrant. The actual coordinates of the two pin holes can be automatically measured by the online measurement function of the machine tool. Then, the coordinates of the two reference holes are called by the global variable function in the program. The actual coordinate value of the radial reference is obtained by automatically calculating the formula obtained by the above theoretical calculation, and finally the automatic positioning of the radial reference is completed.

[0008] (3) In the machining process, the actual coordinate value of the radial reference is used as the center of the circle. The Siemens G03 command is used to theoretically rotate the part into shape. The radial reference of the part can be determined by aligning the rotation circle in subsequent machining. That is, the digital positioning of the radial reference is realized, replacing the reference conversion fixture.

[0009] Step 1: Perform theoretical calculations based on the characteristics of the raw material to obtain mathematical formulas;

[0010] Step 2: When arranging the process, it is required to roughly locate the reference hole in the angular direction of the blank in the positive direction of the X-axis;

[0011] Step 3: Use the online measurement function to automatically measure the actual coordinates of the two pin holes, and call them using global variables to automatically obtain the radial reference coordinates through the formula in Step 1;

[0012] Step 4: Using Siemens G03 commands, with the radial reference coordinate as the center, machine the slewing circle into shape;

[0013] Step 5: In subsequent machining, the radial reference can be determined by directly aligning the rotation circle.

[0014] Explanation of the mathematical modeling process:

[0015] Define the radial reference as point A, and define the two pin holes as points B and C respectively. That is: given triangle AB=AC=272, ∠A=135, and the coordinates of points B and C are (x1, y1) and (x2, y2) respectively, find the coordinates of point A.

[0016] Calculation process:

[0017] The coordinates of the midpoint M are

[0018] slope of BC

[0019] Since AM is perpendicular to BC, the slope of AM is...

[0020] Length of BC

[0021] The length of AM

[0022] Since the slope k' of AM is known, then

[0023] Length of AN Length of MN

[0024] The coordinates of point A are:

[0025] Advantages of this invention:

[0026] The radial datum positioning method for intermediate casings of aero-engines based on blanks described in this invention allows for the positioning of the radial datum solely through CNC machining, eliminating the limitation of dedicated fixtures and solving the problem of machining limitations caused by the special structure of the parts. Furthermore, this positioning technology is universal and can be applied to the machining of all parts whose datum is determined by a "one-face, two-pin" method. It replaces traditional mechanical alignment methods, freeing the datum positioning and machining of this type of blank material from the constraints of dedicated fixtures. It has already been applied in production, saving on the cost of purchasing dedicated fixtures and providing a framework for datum positioning of similar parts in the future. Attached Figure Description

[0027] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments:

[0028] Figure 1 This is a schematic diagram of the part's structure;

[0029] Figure 2 This is a schematic diagram of the mathematical model. Detailed Implementation

[0030] This invention provides a radial reference positioning method for an aero-engine intermediate casing based on a blank, characterized in that: before machining the intermediate casing parts, the blank has no rotational circle for aligning the radial reference; the parts are heavy, approximately 80 kg; the space at the pin hole is narrow; and the pin hole diameter is small.

[0031] The two reference holes are located 272 mm from the theoretical radial reference, and the angle between the line connecting the two reference holes and the radial reference is 135°.

[0032] (1) In order to determine the actual position of the radial reference, based on the blank features, the actual coordinates of the two reference holes are taken as known quantities through mathematical modeling, and the actual coordinate values ​​of the radial reference are obtained through calculation.

[0033] (2) In order to determine the approximate position of the reference hole of the part so that the positioning technology can be effectively implemented in production, by arranging the process, when the part is aligned, one pin hole of the part is located in the positive direction of the X axis. According to the part structure, the other pin hole must be located in the second quadrant. The actual coordinates of the two pin holes can be automatically measured by the online measurement function of the machine tool. Then, the coordinates of the two reference holes are called by the global variable function in the program. The actual coordinate value of the radial reference is obtained by automatically calculating the formula obtained by the above theoretical calculation, and finally the automatic positioning of the radial reference is completed.

[0034] (3) In the machining process, the actual coordinate value of the radial reference is used as the center of the circle. The Siemens G03 command is used to theoretically rotate the part into shape. The radial reference of the part can be determined by aligning the rotation circle in subsequent machining. That is, the digital positioning of the radial reference is realized, replacing the reference conversion fixture.

[0035] Step 1: Perform theoretical calculations based on the characteristics of the raw material to obtain mathematical formulas;

[0036] Step 2: When arranging the process, it is required to roughly locate the reference hole in the angular direction of the blank in the positive direction of the X-axis;

[0037] Step 3: Use the online measurement function to automatically measure the actual coordinates of the two pin holes, and call them using global variables to automatically obtain the radial reference coordinates through the formula in Step 1;

[0038] Step 4: Using Siemens G03 commands, with the radial reference coordinate as the center, machine the slewing circle into shape;

[0039] Step 5: In subsequent machining, the radial reference can be determined by directly aligning the rotation circle.

[0040] Explanation of the mathematical modeling process:

[0041] Define the radial reference as point A, and define the two pin holes as points B and C respectively. That is: given triangle AB=AC=272, ∠A=135, and the coordinates of points B and C are (x1, y1) and (x2, y2) respectively, find the coordinates of point A.

[0042] Calculation process:

[0043] The coordinates of the midpoint M are

[0044] slope of BC

[0045] Since AM is perpendicular to BC, the slope of AM is...

[0046] Length of BC

[0047] The length of AM

[0048] Since the slope k' of AM is known, then

[0049] Length of AN Length of MN

[0050] The coordinates of point A are:

[0051] Matters not covered in this invention are common knowledge.

[0052] The above embodiments are only for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be construed as limiting the scope of protection of the present invention. All equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A radial reference positioning method for an aero-engine intermediate casing based on a blank, characterized in that: The two reference holes are located 272 mm from the theoretical radial reference, and the angle between the line connecting the two reference holes and the radial reference is 135°. (1) Determine the actual position of the radial reference. Based on the blank characteristics, through mathematical modeling, the actual coordinates of the two reference holes are taken as known quantities. After calculation, the actual coordinate values ​​of the radial reference are obtained. (2) When aligning the part, let one pin hole of the part be located in the positive direction of the X axis. According to the part structure, the other pin hole is located in the second quadrant. The actual coordinates of the two pin holes are automatically measured by the online measurement function of the machine tool. Then, the coordinates of the two reference holes are called by the global variable function in the program. Through the mathematical modeling in (1), the coordinates of the radial reference are calculated by the formula obtained by calculating the actual coordinates of the two reference holes. The actual coordinate value of the radial reference is obtained and the automatic positioning of the radial reference is finally completed. (3) During the machining process, the actual coordinate value of the radial reference in (2) is used as the center of the circle. The Siemens G03 command is used to machine the part into a rotary circle. The radial reference of the part can be determined by aligning the rotary circle in subsequent machining. Explanation of the mathematical modeling process: Define the radial reference as point A, and define the two pin holes as points B and C respectively. That is: given triangle AB=AC=272, ∠A=135, and the coordinates of points B and C are (x1, y1) and (x2, y2) respectively, find the coordinates of point A. Calculation process: The coordinates of the midpoint M are slope of BC Since AM is perpendicular to BC, the slope of AM is... Length of BC The length of AM Since the slope k' of AM is known, then Length of AN ; Length of MN The coordinates of point A are: .

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