阅读说明：本技术 一种数控铣加工航空异形零件快速构建基准的方法 (Method for quickly establishing datum for aviation special-shaped part machined through numerical control milling ) 是由 于强 杜威 孟庆国 王洋 杨喆 单彬 董晓萍 刘新裕 于 2021-07-24 设计创作，主要内容包括：本发明提出一种数控铣加工航空异形零件快速构建基准的方法,属于航空零部件机械加工领域。本发明中所述的基准体是按照零件加工需求,基于三维建模软件自行构建并加工的,精度高,且不受毛坯料外形或精度的影响；本发明用于加工异形零件,不需做辅助工装夹具,实现快速、准确、易操作,从而提高产品质量和生产效率,适用于各类数控铣床,各种尺寸的异形零件,应用广泛。(The invention provides a method for quickly establishing a benchmark of an aviation special-shaped part machined by a numerical control milling machine, and belongs to the field of aviation part machining. The reference body is automatically constructed and processed based on three-dimensional modeling software according to the part processing requirements, has high precision and is not influenced by the appearance or precision of a blank material; the special-shaped part machining tool is used for machining special-shaped parts, does not need to be used as an auxiliary tool fixture, and is quick, accurate and easy to operate, so that the product quality and the production efficiency are improved, and the special-shaped part machining tool is suitable for various numerical control milling machines and special-shaped parts with various sizes and is wide in application.)

1. A method for quickly constructing a benchmark by machining aviation special-shaped parts through numerical control milling is characterized by comprising the following steps:

step 1: clamping and fixing the workpiece blank material by using a vice;

step 2: reference point for determining machining reference

Measuring the outer contour of a workpiece blank by using a measuring system of a numerical control milling machine, determining a central point as a datum point, setting coordinates as processing original points (0,0), and establishing a processing coordinate system;

and step 3: creating a datum plane

In UG three-dimensional modeling software, a datum plane is created by taking the datum point as a center; the side of the reference surface is parallel to X, Y coordinate axis, a minimum hexahedron capable of containing the workpiece is drawn by a containing block tool, the length, width and height of the minimum hexahedron are measured as a, b and c respectively, the side length L1 of the reference surface is greater than or equal to the value of a, and the width L2 of the reference surface is greater than or equal to the value of b;

and 4, step 4: construction of a reference body

In UG three-dimensional modeling software, a reference body is constructed by taking a reference surface as a reference; wherein, the edge of the reference surface is taken as the sizing edge of the reference body, the stretching tool is used for stretching along the Z-axis direction, the stretching starting point is 10mm away from the lowest surface of the Z-direction processing shape in the view of the direction, and the stretching starting point is 10mm downward;

and 5: processing the reference body and part of the workpiece, and processing the rest part of the workpiece by taking the reference body as a reference;

step 6: and clamping the plane of the machined part of the workpiece, which can be used as a clamping reference, so as to complete the machining of the part and remove the reference body.

2. The method according to claim 1, wherein the specific steps of the step 5 comprise:

step 5.1: when the first clamping is carried out, firstly, a blank is taken as a reference to mill a reference body, namely four surfaces and a top surface in the direction of X, Y coordinate axes, wherein each surface of the reference body is a fine reference surface, the roughness is not lower than Ra1.6 mu m, and the size precision is not lower than that of a workpiece; then milling the shape of the workpiece in the positive direction of the Z axis;

step 5.2: during the second clamping, the workpiece is inverted, a part of two fine reference surfaces parallel to the Z axis on the machined reference body is clamped, the machining original point is aligned, and the partial shape of the workpiece in the Z axis positive direction is milled;

the height of the precise reference surface of the clamping part is more than or equal to 5mm, the height of the precise reference surface of the exposed part is more than or equal to 5mm, the exposed part of each reference surface of the reference body parallel to the Z-axis direction is found by using a dial indicator, the machining origin (0,0) is determined by 1/2 of the distance of each surface, and a machining coordinate system is established at the surface position of the blank material;

step 5.3: clamping a part of two fine reference surfaces which are perpendicular to the Z-axis direction on the machined reference body during third clamping, aligning a machining original point by using the reference body, and milling the partial shape of the workpiece in the Z-axis positive direction; wherein, the method for aligning the processing origin is the same as the step 5.2;

if the machined part of the workpiece has a fine reference surface, preferentially selecting a surface on the clamped workpiece;

if the part machining can be finished by clamping for the third time, directly performing the step 6; if the clamping and processing times need to be increased, the processing method is carried out according to the content of the step 5.3, and only the clamping direction needs to be changed.

3. The method according to claim 1 or 2, wherein in the step 3, if the workpiece needs to increase the clamping direction, the edge line of the reference surface is increased; when the side lines are added, two side lines symmetrical to the center need to be added at the same time.

Technical Field

The invention belongs to the field of machining of aviation parts and particularly relates to a method for quickly establishing a machining reference in a numerical control milling process of an aviation special-shaped part.

Background

In the field of aeronautical manufacturing, repair, there are a large number of irregularly shaped profiled parts. In the machining process of the parts, as no reference exists, machining personnel always need to face the problems of difficult clamping and alignment. According to a conventional machining method, the parts are machined through rough reference clamping and positioning, the size precision cannot be guaranteed, the product percent of pass is influenced, and certain quality risks exist. The method has the advantages that the clamping and alignment are assisted by manufacturing the tool clamp in the machining process of some special-shaped parts, so that the workload of designers is increased, the working efficiency is reduced, and the production period is prolonged; moreover, the product size error may be increased due to the fitting error of the workpiece and the tool.

Disclosure of Invention

In order to overcome the defects of the prior art, the invention aims to provide a method for quickly constructing a process reference for machining aviation special-shaped parts by numerical control milling, which is quick, accurate and easy to operate, so that the product quality and the production efficiency are improved.

The technical scheme of the invention is as follows:

a method for quickly constructing a benchmark by machining aviation special-shaped parts through numerical control milling comprises the following steps:

step 1: and clamping and fixing the workpiece blank by using a vice.

Step 2: reference point for determining machining reference

Measuring the outer contour of the workpiece blank by using a measuring system of the numerical control milling machine, determining a central point as a datum point, setting coordinates as a processing origin (0,0), and establishing a processing coordinate system.

And step 3: creating a datum plane

In UG three-dimensional modeling software, a datum plane is created by taking a datum point as a center. The side of the reference surface is parallel to (X, Y) coordinate axis, the minimum hexahedron capable of containing the workpiece is drawn by using a 'containing block' tool, the length, width and height of the minimum hexahedron are measured as a, b and c respectively, the side length L1 of the reference surface is greater than or equal to a value, and the width L2 of the reference surface is greater than or equal to b value.

If the workpiece needs to increase the clamping direction, the side line of the reference surface can be increased. When the side lines are added, two side lines symmetrical to the center need to be added at the same time.

And 4, step 4: construction of a reference body

In UG three-dimensional modeling software, a reference body is constructed by taking a reference surface as a reference. Wherein, the side of the reference surface is taken as the sizing side of the reference body, the stretching is carried out along the Z-axis direction by a stretching tool, the stretching starting point is about 10mm away from the lowest surface of the Z-direction processing shape in the view of the direction, the stretching is carried out downwards, and the height is about 10 mm.

And 5: and processing the reference body and part of the workpiece, and processing the rest part of the workpiece by taking the reference body as a reference. The method comprises the following specific steps:

step 5.1: when the first clamping is carried out, firstly, a reference body is milled by taking the blank as a reference (namely four surfaces and the top surface in the direction of X, Y coordinate axes are milled), wherein each surface of the reference body is a fine reference surface, the roughness is not lower than Ra1.6 mu m, and the dimensional accuracy is not lower than that of a workpiece. And then milling the shape of the workpiece in the positive Z-axis direction.

Step 5.2: and during the second clamping, the workpiece is inverted, a part of two fine reference surfaces parallel to the Z axis on the machined reference body is clamped, the machining original point is aligned, and the partial shape of the workpiece on the Z axis positive direction is milled.

The height of the precise reference surface of the clamping part is more than or equal to 5mm, the height of the precise reference surface of the exposed part is more than or equal to 5mm, the exposed part of each reference surface of the reference body in the direction parallel to the Z axis is found by using a dial indicator, the machining origin (0,0) is determined according to 1/2 of the distance of each surface, and a machining coordinate system is established at the surface position of the blank.

Step 5.3: and during third clamping, clamping a part of two fine reference surfaces which are perpendicular to the Z-axis direction on the machined reference body, aligning the machining original point by using the reference body, and milling out the partial shape of the workpiece on the Z-axis positive direction. Wherein the method for aligning the origin is the same as the step 5.2.

If the machined part of the workpiece has a fine reference surface, the surface on the workpiece is preferably clamped.

If the part machining can be finished by clamping for the third time, directly performing the step 6; if the clamping and processing times need to be increased, the processing method is carried out according to the content of the step 5.3, and only the clamping direction needs to be changed.

Step 6: and clamping the plane of the machined part of the workpiece, which can be used as a clamping reference, so as to complete the machining of the part and remove the reference body.

The numerical control milling machine at least should be equipped with a measuring system and a dial indicator.

The invention has the beneficial effects that:

(1) the datum body is automatically constructed and machined based on three-dimensional modeling software according to the part machining requirements, the precision is high, and the influence of the appearance or the precision of a blank material is avoided.

(2) The invention is used for processing the special-shaped parts without an auxiliary tool clamp.

(3) The invention is suitable for various numerical control milling machines and special-shaped parts with various sizes, and has wide application.

Drawings

FIG. 1 is a flow chart of the method of the present invention.

Detailed Description

The following examples and drawings are included to further illustrate the embodiments of the present invention and are not intended to limit the invention thereto.

As shown in fig. 1, a method for quickly constructing a reference for machining an aviation special-shaped part by using a numerical control milling machine comprises the following steps:

step 1: and clamping and fixing the workpiece blank by using a vice.

Step 2: reference point for determining machining reference

Measuring the outer contour of the workpiece blank by using a measuring system of the numerical control milling machine, determining a central point as a datum point, setting coordinates as a processing origin (0,0), and establishing a processing coordinate system.

And step 3: creating a datum plane

In UG three-dimensional modeling software, a datum plane is created by taking a datum point as a center. The side of the reference surface is parallel to (X, Y) coordinate axis, the minimum hexahedron capable of containing the workpiece is drawn by using a 'containing block' tool, the length, width and height of the minimum hexahedron are measured as a, b and c respectively, the side length L1 of the reference surface is greater than or equal to a value, and the width L2 of the reference surface is greater than or equal to b value.

If the workpiece needs to increase the clamping direction, the side line of the reference surface can be increased. When the side lines are added, two side lines symmetrical to the center need to be added at the same time.

And 4, step 4: construction of a reference body

In UG three-dimensional modeling software, a reference body is constructed by taking a reference surface as a reference. Wherein, the side of the reference surface is taken as the sizing side of the reference body, the stretching is carried out along the Z-axis direction by a stretching tool, the stretching starting point is 10mm away from the lowest surface of the Z-direction processing shape in the view of the direction, and the stretching is carried out downwards by 10 mm.

And 5: and processing the reference body and part of the workpiece, and processing the rest part of the workpiece by taking the reference body as a reference. The method comprises the following specific steps:

step 5.1: when the first clamping is carried out, firstly, a reference body is milled by taking the blank as a reference (namely four surfaces and the top surface in the direction of X, Y coordinate axes are milled), wherein each surface of the reference body is a fine reference surface, the roughness is not lower than Ra1.6 mu m, and the dimensional accuracy is not lower than that of a workpiece. And then milling the shape of the workpiece in the positive Z-axis direction.

Step 5.2: and during the second clamping, the workpiece is inverted, a part of two fine reference surfaces parallel to the Z axis on the machined reference body is clamped, the machining original point is aligned, and the partial shape of the workpiece on the Z axis positive direction is milled.

The height of the precise reference surface of the clamping part is more than or equal to 5mm, the height of the precise reference surface of the exposed part is more than or equal to 5mm, the exposed part of each reference surface of the reference body in the direction parallel to the Z axis is found by using a dial indicator, the machining origin (0,0) is determined according to 1/2 of the distance of each surface, and a machining coordinate system is established at the surface position of the blank.

Step 5.3: and during third clamping, clamping a part of two fine reference surfaces which are perpendicular to the Z-axis direction on the machined reference body, aligning the machining original point by using the reference body, and milling out the partial shape of the workpiece on the Z-axis positive direction. Wherein the method for aligning the origin is the same as the step 5.2.

If the machined part of the workpiece has a fine reference surface, the surface on the workpiece is preferably clamped.

If the part machining can be finished by clamping for the third time, directly performing the step 6; if the clamping and processing times need to be increased, the processing method is carried out according to the content of the step 5.3, and only the clamping direction needs to be changed.

Step 6: and clamping the plane of the machined part of the workpiece, which can be used as a clamping reference, so as to complete the machining of the part and remove the reference body.