阅读说明：本技术 一种薄壁零件内孔精密加工方法 (Precision machining method for inner hole of thin-wall part ) 是由 朱鑫波 姚素娴 李伟 张帆 吴清雨 于 2019-08-27 设计创作，主要内容包括：本发明一种薄壁零件内孔精密加工方法,属于薄壁零件高精加工技术领域。本发明通过精研零件定位端面,依靠转接小吸盘间接实现零件装夹校正,并通过进给量、刀具修磨次数、磨削余量以及走刀路线等加工参数的合理选择搭配完成薄壁零件内孔精密加工。该发明方法通过对薄壁零件变形的本质进行深入理论分析,并以各变形因素入手,依此设计了独特的定位面研磨方法、装夹方式以及切削模型,极大地减少了薄壁零件内孔加工过程中所产生的变形,零件内孔圆柱度可控制在0.005mm以内,有效的解决了薄壁零件高精加工的难题。(The invention discloses a precision machining method for an inner hole of a thin-wall part, and belongs to the technical field of high-precision machining of thin-wall parts. According to the invention, the part positioning end face is finely ground, the part clamping correction is indirectly realized by virtue of the small switching sucker, and the precision machining of the inner hole of the thin-wall part is completed by reasonably selecting and matching machining parameters such as the feeding amount, the tool grinding times, the grinding allowance, the feed route and the like. According to the method, the deformation nature of the thin-wall part is deeply theoretically analyzed, and a unique positioning surface grinding method, a clamping mode and a cutting model are designed based on various deformation factors, so that the deformation generated in the process of machining the inner hole of the thin-wall part is greatly reduced, the cylindricity of the inner hole of the part can be controlled within 0.005mm, and the problem of high-precision machining of the thin-wall part is effectively solved.)

1. A precision machining method for an inner hole of a thin-wall part is characterized by comprising the following steps:

1) positioning end face of the fine grinding part (3):

① pressing the part (3) by hand to push the end face until the end face is completely ground;

② covering the part (3) with a sleeve larger than the outer diameter of the part (3) to drive the part (3) to finish the positioning end face (not allowing to apply axial pressure);

2) placing the part (3) on the switching small sucker (2) in a free state, and opening the small sucker (2) to tightly suck the part (3) by magnetic force;

3) adsorbing the small sucker (2) on the large sucker (1) of the numerical control grinding machine, and correcting the inner hole of the part (3) by knocking the small sucker (2) to ensure that the center jump of the inner hole of the part (3) is not more than 0.003 mm;

4) grinding is carried out according to the following processing parameters:

① the cutting depth of the grinding wheel (4) is less than or equal to 0.002 mm;

② grinding wheel (4) feed route is axial insertion type, and the outside of the part (3) is fed;

③ the inner hole of the part (3) has a removal margin less than or equal to 0.02 mm;

5) after grinding is finished, the magnetic force of the small sucker (2) is closed, and the part (3) is gently taken down.

2. The precision machining method for the inner hole of the thin-walled part is characterized in that the flatness of the positioning surface of the thin-walled part is larger than 0.003 mm.

3. The precision machining method for the inner hole of the thin-walled part is characterized in that the linear speed of a grinding wheel is not less than 20m/s during machining of the thin-walled part.

4. The precision machining method for the inner hole of the thin-wall part is characterized in that the inner hole center runout of the part (3) is not more than 0.003 mm.

5. The precision machining method for the inner hole of the thin-walled part is characterized in that the feed speed of the grinding wheel (4) is not more than 150 m/s.

6. The precision machining method for the inner hole of the thin-walled part is characterized in that the linear speed of the part (3) is not less than 0.5 m/s.

7. The precision machining method for the inner hole of the thin-wall part is characterized in that the grinding frequency of the grinding wheel (4) is more than 1 every time 0.01 allowance is removed from the inner hole of the part (3).

8. The precision machining method for the inner hole of the thin-wall part is characterized in that the cylindricity of the inner hole of the part (3) before machining is less than 0.01.

Technical Field

The invention discloses a precision machining method for an inner hole of a thin-wall part, and belongs to the technical field of high-precision machining of thin-wall parts.

Background

At present, the precision machining of the inner hole of the thin-wall part is generally to press the part by hand to push and grind a positioning end face, then directly adsorb the positioning face of the part by using a precision numerical control grinder, knock the part to align the center of the inner hole, then grind the inner hole of the part by using general cutting parameters and a conventional radial feed route, and commonly obtain the grinding allowance of more than 0.05mm in the whole cutting process. Firstly, because the part belongs to the thin wall spare, directly press the part with the hand and can lead to the part terminal surface to produce little the deformation, the terminal surface grinds the back, loosens the part, and part location terminal surface is little to be out of shape and kick-backs, and the part plane degree is general not high to lead to the part to adsorb back location terminal surface deformation, when taking off the part after the grinding, location terminal surface deformation kick-backs, thereby leads to the hole precision to descend. Secondly, directly strike part correction part hole, can make the part produce the slip deformation, when the grinding was accomplished and is taken off the part, this deformation resilience, part hole precision descends. In addition, the radial feed path of the grinding wheel can enable the grinding wheel to directly generate a radial extrusion force on the hole wall in the feeding process, unreasonable processing parameters directly increase the cutting resistance in the cutting process of the grinding wheel, and the radial stress of parts is overlarge to generate cutting deformation. Finally, the more the inner hole removal allowance is, the more serious the inner hole internal stress balance is broken, the larger the part stress deformation is, and the higher the removal allowance above 0.05mm is. In conclusion, the superposition of all the factors finally results in that the machining precision of the inner hole of the thin-wall part is always low and the machining stability is poor.

Disclosure of Invention

The purpose of the invention is as follows: aiming at the problems in the prior art, the invention provides a method for precisely machining an inner hole of a thin-wall part, which solves the problems of large machining deformation, unstable machining quality and low precision of the inner hole of the prior thin-wall part by a special set of fine grinding method, clamping method, axial insertion type feed line, machining parameter optimization and other measures.

The technical scheme of the invention is as follows:

in order to achieve the purpose, the technical scheme of the invention is that the method for precisely machining the inner hole of the magnetic thin-wall part comprises the following steps:

1) finely grinding the positioning end face of the part 3:

① pressing the part 3 on the grinding platform by hand to grind the end face until the end face is ground completely;

② covering the part 3 with a sleeve 5 having an outer diameter larger than that of the part 3 to laterally drive the part 3 to finish the positioning end face (not allowing axial pressure to be applied);

2) placing the part 3 on the small switching sucker 2 in a free state, and opening the small switching sucker 2 to tightly suck the part 3 by magnetic force;

3) adsorbing the switching small sucker 2 on the large magnetic sucker 1 of the numerically-controlled grinding machine, and correcting the center of an inner hole of a part 3 on the center of the main shaft by knocking the switching small sucker 2;

4) grinding is carried out according to the following processing parameters:

① the cutting depth of the grinding wheel 4 is less than or equal to 0.002 mm;

② grinding wheel 4 feed path, axial insertion (part 3 outside feed);

③ the inner hole of part 3 has a removal margin less than or equal to 0.02 mm;

5) after the grinding is finished, the magnetic force of the small sucker 2 is closed, and the part 3 is gently taken down.

The flatness of the positioning surface of the thin-wall part is greater than 0.003 mm.

The linear speed of the grinding wheel is not less than 20m/s when the thin-wall part is processed.

The runout of the center of the inner hole of the part 3 is not more than 0.003 mm.

The feed speed of the grinding wheel 4 is not more than 150 m/s.

The linear speed of the part 3 is not less than 0.5 m/s.

And the grinding frequency of the grinding wheel 4 is more than 1 when the allowance of 0.01 of the inner hole of the part 3 is removed.

The cylindricity of the inner hole of the part 3 is less than 0.01 before machining.

The invention has the beneficial effects that: the precision machining method for the inner hole of the thin-wall part starts from three aspects of clamping deformation, cutting deformation and internal stress deformation generated in the machining process of the thin-wall part, and performs full-flow fine control on the whole machining process of the part from macroscopic and microscopic angles, so that the machining deformation of the inner hole of the thin-wall part is reduced powerfully, the cylindricity of the inner hole of the part is generally below 0.005mm, the machining is stable, and the problem of high-precision machining of the thin-wall part is solved effectively.

Description of the drawings:

FIG. 1 is a schematic view of the clamping process of the present invention

FIG. 2 is a schematic view of the positioning end face of the lapping part of the present invention

FIG. 3 is a schematic view of the grinding wheel feed of the present invention wherein: 1-numerically controlled grinder magnetic large sucker, 2-switching small sucker, 3-part, 4-grinding wheel, 5-sleeve and 6-grinding wheel feed path

FIG. 4 is a schematic view of the processing of example 1 of the present invention

Detailed Description

The present invention will be described in further detail with reference to the following embodiments.

In order to achieve the purpose, the technical scheme of the invention is that the method for precisely machining the inner hole of the magnetic thin-wall part comprises the following steps:

1) finely grinding the positioning end face of the part 3:

① pressing the part 3 on the grinding platform by hand to grind the end face until the end face is ground completely;

② covering the part 3 with a sleeve 5 with an outer diameter larger than that of the part 3 to drive the part 3 to finish the positioning end face (not allowing axial pressure to be applied) and ensuring that the flatness of the positioning face of the part is not more than 0.003 mm;

2) placing the part 3 on the small switching sucker 2 in a free state, and opening the small switching sucker 2 to tightly suck the part 3 by magnetic force;

3) adsorbing the small switching sucker 2 on the large magnetic sucker 1 of the numerically-controlled grinding machine, and correcting the center offset of the inner hole of the part 3 by knocking the small switching sucker 2 to be not more than 0.003 mm;

4) grinding is carried out according to the following processing parameters:

① the cutting depth of the grinding wheel 4 is less than or equal to 0.002 mm;

② grinding wheel 4 feed path axial insert part 3 outside feed);

③ the inner hole of part 3 has a removal margin less than or equal to 0.02 mm;

④ the feed speed of grinding wheel 4 is not more than 150 m/s;

⑤ the linear velocity of the outer edge of the grinding wheel 4 is not less than 20 m/s;

⑥ linear velocity of inner hole of part 3 is not less than 0.5 m/s;

⑦, the grinding frequency of the grinding wheel 4 is more than 1 when the allowance of 0.01 of the inner hole of the part 3 is removed;

5) after the grinding is finished, the magnetic force of the switching small sucker 2 is closed, and the part 3 is gently taken down.

The cylindricity of the inner hole of the part 3 is less than 0.01mm before processing.