阅读说明：本技术 一种叶片上不规则型面的数控磨削方法 (Numerical control grinding method for irregular profile on blade ) 是由 梁忠效 卢鹏 田小康 杨林 孟少轩 王伟涛 庞杰 邓沛 于 2021-06-30 设计创作，主要内容包括：本发明提供一种叶片上不规则型面的数控磨削方法,将所述不规则型面分成若干个加工表面,针对每个加工表面分别建立控制磨削路径的磨削程序,对每个加工表面按照相应的磨削程序分别进行数控磨削。本发明待加工不规则型面多个加工表面组合而成,针对每个加工表面分别独立建立控制磨削路径的磨削程序,对每个加工表面分别进行磨削,避免传统的编程方式导致的磨削路径在边角处集中,使整个阻尼台型面单位面积所受的磨削强度统一,避免因重复磨削导致阻尼台原有的几何属性被破坏。(The invention provides a numerical control grinding method for an irregular profile on a blade, which is characterized in that the irregular profile is divided into a plurality of processing surfaces, a grinding program for controlling a grinding path is respectively established for each processing surface, and each processing surface is respectively subjected to numerical control grinding according to the corresponding grinding program. The invention is formed by combining a plurality of processing surfaces of the irregular profile to be processed, and a grinding program for controlling a grinding path is respectively and independently established for each processing surface to grind each processing surface, thereby avoiding the concentration of the grinding path at the edge caused by the traditional programming mode, unifying the grinding strength of the profile unit area of the whole damping platform, and avoiding the damage of the original geometric attribute of the damping platform caused by repeated grinding.)

1. A numerical control grinding method for an irregular profile on a blade is characterized in that the irregular profile is divided into a plurality of processing surfaces, a grinding program for controlling a grinding path is respectively established for each processing surface, and numerical control grinding is respectively carried out on each processing surface according to the corresponding grinding program.

2. The method for numerically controlled grinding of irregular profiles on blades according to claim 1, characterized in that the establishment of the grinding program is in particular: and establishing a mathematical model according to the machined surface, wherein a parameter curve in the mathematical model is consistent with the edge trend of the machined surface, and generating a grinding program according to the mathematical model.

3. The method of claim 1, wherein the irregular profile is a damping table profile or a platform profile.

4. The method of claim 1, wherein the angle between the axis of rotation of the grinding head of the machine tool and the Z axis of the machine tool is 60 °.

5. The numerical control grinding method for the irregular profiles on the blades as claimed in claim 4, wherein the grinding head of the machine tool comprises a support rod (1), the support rod (1) comprises a connecting section and a grinding section, the grinding section of the support rod (1) and the connecting section are arranged at an included angle, the grinding section of the support rod (1) is provided with a contact wheel (4) through a contact wheel shaft (5), the contact wheel shaft (5) is perpendicular to the grinding section of the support rod (1), and the connecting section and the grinding section of the contact wheel shaft (5) and the support rod (1) are coplanar; wherein, the included angle between the connecting sections of the contact wheel shaft (5) and the support rod (1) is 60 degrees; an abrasive belt (10) is arranged on the contact wheel (4).

6. The numerical control grinding method for the irregular profiles on the blades as claimed in claim 5, wherein a guide wheel shaft (3) is installed at the connecting section of the supporting rod (1), the guide wheel shaft (3) is perpendicular to the plane where the connecting section of the supporting rod (1) and the grinding section are located, and guide wheels (2) are installed at two ends of the guide wheel shaft (3) respectively; one end of the abrasive belt (10) is arranged on the contact wheel (4) after passing through the guide wheel (2).

7. Method for the numerically controlled grinding of irregular profiles on blades according to claim 6, characterised in that the two guide wheels (2) are symmetrical with respect to the connecting section of the supporting bar (1).

8. The method for numerically controlled grinding of irregular profiles on blades according to claim 6, characterized in that the connecting section of the support bar (1) is fitted with a guide hub (3) through a guide hub (6).

9. The machine tool grinding head is characterized by comprising a supporting rod (1), wherein the supporting rod (1) comprises a connecting section and a grinding section, the grinding section of the supporting rod (1) and the connecting section form an included angle, the grinding section of the supporting rod (1) is provided with a contact wheel (4) through a contact wheel shaft (5), the contact wheel shaft (5) is perpendicular to the grinding section of the supporting rod (1), and the connecting section and the grinding section of the contact wheel shaft (5) and the supporting rod (1) are coplanar; wherein, the included angle between the connecting sections of the contact wheel shaft (5) and the stay bar (1) is 60 degrees; an abrasive belt (10) is arranged on the contact wheel (4).

10. The machine tool grinding head according to claim 9, wherein the connecting section of the support rod (1) is provided with a guide wheel shaft (3), the guide wheel shaft (3) is perpendicular to the connecting section of the support rod (1), the guide wheel shaft (3) is perpendicular to the plane where the connecting section of the support rod (1) and the grinding section are located, and two ends of the guide wheel shaft (3) are respectively provided with a guide wheel (2); one end of the abrasive belt (10) is arranged on the contact wheel (4) after passing through the guide wheel (2).

Technical Field

The invention belongs to the field of blade processing, and relates to a refined numerical control grinding method for an irregular profile on a blade.

Background

As for the parts such as the blade, the blade profile grinding and air inlet and outlet edge grinding technology is basically mature at present. The blade is subjected to large-scale application by grinding and polishing of numerical control equipment instead of traditional manual polishing, and the problems of unstable quality, high labor intensity of workers and the like of the traditional polishing process are solved.

However, due to the restrictions of the equipment operation mechanism and the driving processing of the profile, the irregular profiles such as the edge plate and the damping table are still the blind areas of the numerical control grinding technology, the damping table surface has a small overall area and an irregular shape due to its special structure, the damping table surface is often divided into a plurality of independent surfaces, for example, the damping table is often transited by the switching R between two surfaces connected with each other, and the overall profile is easy to damage the switching R during grinding, so that the geometric properties of the profile are changed (as shown in fig. 2).

Therefore, the grinding of the profile of the edge plate and the damping table still needs to be carried out by adopting the traditional manual polishing mode, the labor intensity of workers is high, and the grinding quality cannot be guaranteed.

Therefore, it is urgently needed to develop a numerical control grinding method suitable for the irregular profile of the blade so as to reduce the labor intensity of workers and improve the grinding quality.

Disclosure of Invention

Aiming at the problems in the prior art, the invention provides a numerical control grinding method for an irregular profile on a blade, which reduces the labor intensity of workers and improves the grinding quality.

The invention is realized by the following technical scheme:

a numerical control grinding method for an irregular profile on a blade divides the irregular profile into a plurality of processing surfaces, respectively establishes a grinding program for controlling a grinding path for each processing surface, and respectively carries out numerical control grinding on each processing surface according to the corresponding grinding program.

Preferably, the grinding procedure is established by: and establishing a mathematical model according to the machined surface, wherein a parameter curve in the mathematical model is consistent with the edge trend of the machined surface, and generating a grinding program according to the mathematical model.

Preferably, the irregular profile is a damping platform profile or a platform profile.

Preferably, the included angle between the rotation axis of the grinding head of the machine tool and the Z axis of the machine tool adopted by the numerical control grinding is 60 degrees.

Furthermore, the machine tool grinding head comprises a supporting rod, the supporting rod comprises a connecting section and a grinding section, the grinding section and the connecting section of the supporting rod are arranged at an included angle, the grinding section of the supporting rod is provided with a contact wheel through a contact wheel shaft, the contact wheel shaft is perpendicular to the grinding section of the supporting rod, and the contact wheel shaft is coplanar with the connecting section and the grinding section of the supporting rod; wherein, the included angle between the connecting sections of the contact wheel shaft and the support rod is 60 degrees; the contact wheel is provided with an abrasive belt.

Furthermore, a guide wheel shaft is arranged at the connecting section of the supporting rod, the guide wheel shaft is vertical to the plane where the connecting section of the supporting rod and the grinding section are located, and two ends of the guide wheel shaft are respectively provided with a guide wheel; one end of the abrasive belt is arranged on the contact wheel after passing through the guide wheel.

Further, the two guide wheels are symmetrical about the connecting section of the support rod.

Furthermore, the connecting section of the support rod is provided with a guide wheel shaft through a guide wheel shaft sleeve.

A machine tool grinding head comprises a supporting rod, wherein the supporting rod comprises a connecting section and a grinding section, the grinding section and the connecting section of the supporting rod are arranged at an included angle, a contact wheel is mounted on the grinding section of the supporting rod through a contact wheel shaft, the contact wheel shaft is perpendicular to the grinding section of the supporting rod, and the contact wheel shaft is coplanar with the connecting section and the grinding section of the supporting rod; wherein, the included angle between the connecting sections of the contact wheel shaft and the support rod is 60 degrees; the contact wheel is provided with an abrasive belt.

Preferably, the connecting section of the supporting rod is provided with a guide wheel shaft, the guide wheel shaft is vertical to the connecting section of the supporting rod and vertical to the plane of the connecting section of the supporting rod and the plane of the grinding section, and two ends of the guide wheel shaft are respectively provided with a guide wheel; one end of the abrasive belt is arranged on the contact wheel after passing through the guide wheel.

Compared with the prior art, the invention has the following beneficial technical effects:

the invention is formed by combining a plurality of processing surfaces of the irregular profile to be processed, and a grinding program for controlling a grinding path is respectively and independently established for each processing surface to grind each processing surface, thereby avoiding the concentration of the grinding path at the edge caused by the traditional programming mode, unifying the grinding strength of the profile unit area of the whole damping platform, and avoiding the damage of the original geometric attribute of the damping platform caused by repeated grinding.

Further, the basic principle of establishing the grinding procedure is as follows: the mathematical model is re-established according to the characteristics of the processed surface, so that the parameter curve of the mathematical model is consistent with the edge trend of the processed surface, and the grinding route of the processing program generated based on the mathematical model is also along the edge direction of the processed surface. Thus, the original geometric parameters of the molded surface can be kept to the maximum extent by grinding.

Furthermore, the invention designs a brand new grinding head of the machine tool based on the original structure of the machine tool. The included angle between the rotation axis of the grinding head of the machine tool and the Z axis of the machine tool is designed to be 60 degrees, when the abrasive belt is used for grinding, the original vertical downward belt traveling direction of the abrasive belt is changed, the cross section of the contact wheel forms a 30-degree included angle with the Z axis of the main shaft, and a grinding head blind area which cannot be machined by the grinding head of the traditional machine tool can be machined. The double-grinding-head grinding machine can be suitable for grinding profiles with various angles by matching with a double-grinding-head structure of a machine tool. Therefore, the numerical control grinding processing can be carried out on the molded surfaces of the damping table, the edge plate and the like, and the problem that the grinding head has a blind area is solved.

The machine tool grinding head can process a grinding head blind area which cannot be processed by a traditional machine tool grinding head. The machine tool grinding head can be suitable for grinding profiles with various angles by matching with a double-grinding-head structure of a machine tool. Therefore, the numerical control grinding processing can be carried out on the molded surfaces of the damping table, the edge plate and the like, and the problem that the grinding head has a blind area is solved.

Drawings

FIG. 1 is a schematic view of a grinding head of a conventional machine tool;

FIG. 2 is a profile grinding path profile of a prior art method;

FIG. 3 is a profile grinding path profile in the method of the present invention;

FIG. 4 is a schematic view of a conventional grinding head and abrasive belt;

FIG. 5 is a structural diagram of a grinding head and a sanding belt of the machine tool according to the present invention; (a) is a side view; (b) is a front view;

FIG. 6 is a schematic diagram of the grinding of the novel grinding head;

in the figure: 1. a support bar; 2. a guide wheel; 3. a guide wheel shaft; 4. a contact wheel; 5. a contact axle; 6. a guide wheel shaft sleeve; 7. a damping table; 8. a flange plate; 9. a grinding head blind area; 10. an abrasive belt.

Detailed Description

The present invention will now be described in further detail with reference to specific examples, which are intended to be illustrative, but not limiting, of the invention.

Taking a certain machine first-stage rotor blade as an example, the grinding difficulty of the damping platform and the flange plate mainly comprises the following two points:

1. the damping table surface has the following characteristics due to the special structure: firstly, the damping table is small in integral area and irregular in shape, and the distribution of a grinding path can be directly influenced; secondly, the damping table surface is often subdivided into a plurality of separate surfaces, and when generating the program, the program must be adapted to the characteristics of each surface. For example, the damping table is often transited by a transition R between two surfaces connected with each other. The integral profile is susceptible to damage to these transitions R during grinding, causing changes in the geometry of the profile (see fig. 2).

2. The first-stage rotor blade adopts a universal fixing mode of clamping a blade root and tightly jacking a blade tip. This results in the normal vector of the edge plate, damping table profile being perpendicular to the machine spindle, whereas the device B-axis stroke is-45 to 45 degrees, so that conventional grinding wheels cannot touch both blade profiles. Therefore, if the processing of the edge plate of the blade and the molded surface at the damping platform is to be free from the traditional manual polishing processing mode, the existing equipment needs to be modified so as to be suitable for the clamping state of the existing parts.

Aiming at the two difficulties of the damping table grinding, the invention aims at solving the two problems by the following contents:

1. aiming at the first difficult problem

The invention carries out thinning treatment and slicing grinding on a plurality of plane grinding schemes of the damping table. The grinding path of each small sheet body (namely each processing surface) of the damping table is optimized, and the grinding working principle of the numerical control equipment is that the equipment controls a rotating abrasive belt to act on a ground profile under certain pressure, so that the step pitch of the grinding path directly influences the removal amount. For the damping table which is a sheet body with an irregular shape, the grinding path is concentrated at the corners by adopting a traditional programming mode; in order to avoid uneven removal of the molded surface, the grinding paths must be finely distributed, so that the grinding strength of the molded surface of the whole damping table in unit area is uniform, and the original geometric attributes of the damping table are prevented from being damaged due to repeated grinding. When the software adopts the data model to generate the grinding program, the parameter curve is the important basis for controlling the distribution of the grinding path by the software. Therefore, a new mathematical model of the sheet can be created based on the original mathematical model, and the grinding path distribution of the machined surface can be specifically controlled by the parameter curve of the sheet in the mathematical model. The parameter curve of the sheet body is uniform, and the direction of the parameter curve is close to the switching R boundary of the part; and the parameter curve of the new combined surface after the combination of all the processing surfaces is optimized, so that the grinding path can better match the edge characteristic of the molded surface, and the influence of grinding on the original geometric attribute of the molded surface is avoided (as shown in figure 3).

Specifically, the irregular profile to be machined is formed by combining a plurality of machining surfaces, and a grinding program for controlling a grinding path is independently established for each machining surface. The basic principle for establishing the grinding program is as follows: the mathematical model is re-established according to the characteristics of the processed surface, so that the parameter curve of the mathematical model is consistent with the edge trend of the processed surface, and the grinding route of the processing program generated based on the mathematical model is also along the edge direction of the processed surface. Thus, the original geometric parameters of the molded surface can be kept to the maximum extent by grinding.

2. For the second difficult problem

As shown in figure 1, the traditional grinding head can only grind a profile with an included angle between a normal vector and a Z axis smaller than 45 degrees, so the problem of limitation of a machine tool grinding device is solved when the profile of a damping table and a flange plate is ground. As shown in fig. 4, the conventional general grinding head has the following limitations: 1. the rotation axis of the grinding head is perpendicular to the Z axis of the machine tool, so that the normal vector direction of the molded surface is parallel to the Z axis of the machine tool to grind. Considering the stroke interval of the B axis, the included angle between the normal vector and the Z axis can not be more than 45 degrees, and the grinding requirement can be met; 2. the effective working position of the grinding head is three millimeters away from the edge of the grinding head. Therefore, when the edge of the ground profile needs to be avoided, a grinding blind area is inevitably formed under the influence of the grinding head structure. Taking a certain machine primary rotor as an example, the most serious dead zone is 15 mm wide due to the influence of the structure of a workpiece.

In order to solve the problem, the invention designs a brand new grinding head of the machine tool based on the original structure of the machine tool. Firstly, the included angle between the rotation axis of the grinding head of the machine tool and the Z axis of the machine tool is designed to be M (M is preferably 60 degrees), and two guide wheels are designed above the grinding head to change the direction of the abrasive belt so as to adapt to the angle of a new grinding head.

The structure diagram is shown in fig. 5. Including bracing piece 1, bracing piece 1 includes interconnect's linkage segment and grinding section, and the grinding section and the linkage segment of bracing piece 1 are the contained angle setting, and contact wheel 4 is installed through contact shaft 5 to the grinding section of bracing piece 1, and contact shaft 5 is perpendicular and contact shaft 5 and bracing piece 1's linkage segment and grinding section coplanar with the grinding section of bracing piece 1. The included angle between the connecting sections of the contact wheel shaft 5 and the supporting rod 1 is M, and M is 60 degrees.

The connecting section of the supporting rod 1 is provided with a guide wheel shaft 3 through a guide wheel shaft sleeve 6, the guide wheel shaft 3 is perpendicular to the connecting section of the supporting rod 1, the guide wheel shaft 3 is perpendicular to the plane of the connecting section of the supporting rod 1 and the plane of the grinding section, two ends of the guide wheel shaft 3 are respectively provided with a guide wheel 2, and the two guide wheels 2 are symmetrical about the connecting section of the supporting rod 1.

When the novel machine tool grinding head works, the abrasive belt 10 changes the original vertical downward belt traveling direction through the guide wheel 2. The cross section of the contact wheel and the Z axis of the main shaft form an included angle of 30 degrees, and a grinding head dead zone 9 (shown in figure 6) which cannot be machined by a grinding head of a traditional machine tool can be machined. The machine tool grinding head can be suitable for grinding profiles with various angles by matching with a double-grinding-head structure of a machine tool. Therefore, the numerical control grinding processing can be carried out on the molded surfaces of the damping table, the edge plate and the like, and the problem that the grinding head has a blind area is solved.