CN112008102B

CN112008102B - Boring method for elliptical hole of bushing

Info

Publication number: CN112008102B
Application number: CN202010687949.9A
Authority: CN
Inventors: 陈云; 符垚慧梅; 龚清洪; 夏士伟; 邓乙凡; 王元军; 方雨舟; 张超
Original assignee: Chengdu Aircraft Industrial Group Co Ltd
Current assignee: Chengdu Aircraft Industrial Group Co Ltd
Priority date: 2020-07-16
Filing date: 2020-07-16
Publication date: 2022-06-14
Anticipated expiration: 2040-07-16
Also published as: CN112008102A

Abstract

The invention discloses a boring method of an elliptical hole of a bushing, which is characterized in that a machining coordinate system is established by taking the center of the elliptical hole of the bushing as an original point, and a boring cutter conducts multiple equidistant offset machining along the forward direction or the reverse direction of a machining direction from the original point. According to the invention, the tool-connecting steps on the inner wall of the elliptical hole can be effectively reduced through continuous equidistant offset boring, the processing quality is improved, and the tool-back risk of a long boring tool is avoided when a deep hole is processed. When the boring machine is used for boring the elliptical hole, the uniform deviation of each cutter is determined by a numerical control program, the boring machine is accurate and controllable, and the operation of workers and machining errors caused by the operation can be effectively reduced.

Description

Boring method for elliptical hole of bushing

Technical Field

The invention belongs to the technical field of machining, and particularly relates to a boring method of an elliptical hole of a bushing.

Background

In the machining process of parts, in order to meet the requirements of assembly and use, the bushing is generally required to prepare an elliptical hole with high precision. Boring when the two sides of the major axis of the elliptical hole are respectively offset to the maximum value by using a boring cutter, and leaving a larger cutter connecting step at the hole wall cutter connecting position to influence the surface quality of the part; because some lining materials (such as 30 CrMnSiA) have higher special performance and rigidity and are difficult to cut, the traditional processing method is that a boring cutter is vertically offset to directly bore an elliptical hole to the final size once, the cutting amount is large, the cutting force is large, the cutter is likely to break teeth, the surface of a part is scratched, and the stability and the safety of the processing process are reduced; when a deep hole is machined, the working length of a boring cutter is large, the rigidity is insufficient, cutter back-off can occur, and the final machining size precision of a part is influenced; based on this, a boring method of an elliptical hole of a bushing is provided for improving the machining precision and stability of the bushing.

Disclosure of Invention

The invention discloses a boring method of an elliptical hole of a bushing, aiming at solving the problems, the boring method enables the machining process to be more stable, and can effectively avoid cutter tooth breakage caused by large cutting allowance and excessive cutting force. Aiming at deep hole machining, by adjusting the offset of each cutter, the cutter back-off condition caused by the fact that the working length of the boring cutter is large and the rigidity of the cutter is insufficient can be effectively avoided, and the machining precision of parts is guaranteed.

The invention is mainly realized by the following technical scheme: a machining coordinate system is established by taking the center of the elliptical hole of the bushing as an original point, and a boring cutter conducts multiple equidistant offset machining in the forward direction or the reverse direction of the machining direction from the original point until a machining end point stops.

In order to better implement the invention, further, the boring cutter performs equidistant offset boring according to 0.2 mm.

In order to better realize the invention, a machining coordinate system is further established by taking the center of the elliptical hole of the short bushing as an origin, and the boring cutter respectively performs circle center upward equidistant shift for a plurality of times and circle center downward equidistant shift for a plurality of times along the Y direction of the machining coordinate system until end points at two ends of the major axis of the elliptical hole are machined.

In order to better implement the invention, further, the total offsets of the circle center which is equidistantly shifted upwards and the circle center which is equidistantly shifted downwards are respectively 1mm, and the circle center is equidistantly shifted upwards for 5 times and the circle center is equidistantly shifted downwards for 5 times.

In order to better implement the invention, furthermore, when the long bushing is machined, the working length L of the boring cutter is greater than the length H of the bushing.

The invention has the beneficial effects that:

(1) according to the invention, the tool-connecting steps on the inner wall of the elliptical hole can be effectively reduced through continuous equidistant offset boring, the processing quality is improved, and the tool-back risk of a long boring tool is avoided when a deep hole is processed. When the boring machine is used for boring the elliptical hole, the uniform deviation of each cutter is determined by a numerical control program, the boring machine is accurate and controllable, and the operation of workers and machining errors caused by the operation can be effectively reduced.

(2) The offset of each tool is uniform and controllable, the size of the tool receiving step of the hole wall can be controlled by adjusting the offset, and the surface quality of the hole wall of the elliptical hole is improved, the offset of each tool is controlled aiming at materials which are difficult to machine (such as 30 CrMnSiA), so that the machining process is more stable, and the tool tooth breakage caused by large cutting allowance and overlarge cutting force can be effectively avoided; aiming at deep hole machining, the offset of each cutter is adjusted, the cutter back-off condition caused by the fact that the working length of the boring cutter is large and the rigidity of the cutter is insufficient can be effectively avoided, and the machining precision of parts is guaranteed.

Drawings

FIG. 1 is an assembly view of a short bushing for a part;

FIG. 2 is a cross-sectional view taken along line A-A of FIG. 1;

FIG. 3 is a schematic structural view of the upper half of the bored elliptical hole;

FIG. 4 is a schematic structural diagram of the lower half of the bored elliptical hole;

FIG. 5 is a residual comparison of a conventional bore and a bore of the present invention;

FIG. 6 is an assembled view of the elongated bushing of the part;

FIG. 7 is a cross-sectional view taken along line A-A of FIG. 6;

FIG. 8 is a schematic view of the construction of a long bushing;

fig. 9 is a schematic structural diagram of a boring cutter back-off tool.

Wherein: 1-part, 2-short bush, 3-processing coordinate system, 8-boring cutter and 9-long bush.

Detailed Description

Example 1:

a boring method of an elliptical hole of a bushing is used for boring the elliptical hole of a short bushing 2, as shown in figures 1-2: and establishing a machining coordinate system 3 by taking the center of the elliptical hole of the short bushing 2 as an original point, wherein the center of the elliptical hole of the bushing is equidistantly shifted upwards for 5 times (total offset is 1 mm) and is equidistantly shifted downwards for 5 times (total offset is 1 mm) in the Y + direction and the Y-direction of the machining coordinate system 3 respectively. The centre of a circle of the initial hole is equidistantly shifted upwards for 5 times (total offset is 1 mm), the centre of a circle is equidistantly shifted downwards for 5 times (total offset is 1 mm), the offset of each boring hole is only 0.2mm, and the cutting allowance can be effectively reduced to protect the cutter and improve the machining precision.

As shown in fig. 3, in the process of boring the bushing elliptical hole with the accuracy requirement 4, the total upward offset 5 of the circle center is divided into five equal parts, the boring cutter 8 starts from the original point of the machining coordinate system 3, and bores five times by sequentially offsetting 0.2mm in the Y + direction until the end point of the elliptical hole major axis is machined, so that the boring effect of the total upward offset of 1mm is achieved.

As shown in fig. 4, the total downward offset of 1mm from the center of the circle is divided into five equal parts, and the boring tool 8 performs five boring operations by sequentially shifting 0.2mm in the Y-direction from the origin of the machining coordinate system 3 through the control of the numerical control program until the other end point of the major axis of the elliptical hole is machined, thereby achieving the cutting effect of the total downward offset of 1 mm.

The track of the boring cutter 8 is started from the original point of the processing coordinate system 3, the boring is continuously and equivalently carried out for 5 times in the Y + direction to achieve the original cutting effect of offsetting the total offset for one time by 1mm, and then the boring is continuously and equivalently carried out for 5 times in the opposite direction (Y-direction) from the original point of the processing coordinate system 3 to achieve the original cutting effect of offsetting the total offset for one time by 1mm, so that the cutter connecting steps on the inner wall of the elliptical hole can be effectively reduced, the processing quality is improved, and the cutter back-off risk of the long boring cutter 8 is avoided when the deep hole is processed.

As shown in fig. 5, fig. 5 (a) is an elliptical hole obtained by a conventional boring method, and fig. 5 (b) is an elliptical hole obtained by boring according to the present invention. Compared with the traditional bushing elliptical hole boring method, the method has the advantages that the total upward deviation of the circle center is 1mm, the total downward deviation of the circle center is 1mm, the total upward deviation of the circle center is evenly divided, the tool receiving residue on the inner wall of the elliptical hole is effectively reduced, and meanwhile, the processing stability of the material difficult to process is improved. When the boring machine is used for boring the elliptical hole, the uniform deviation of each cutter is determined by a numerical control program, the boring machine is accurate and controllable, and the operation of workers and machining errors caused by the operation can be effectively reduced.

As shown in fig. 6-9, when the long bush 9 is machined, the working length L of the boring cutter 8 is greater than the length H of the bush, and the center of the circle is equidistantly shifted upwards for 5 times (total offset 1 mm) and downwards for 5 times (total offset 1 mm), so that the cutter back-off condition caused by insufficient cutter rigidity (cutter back-off H1 is reduced or zero) is effectively avoided, and the dimensional accuracy of the part 1 is ensured.

The offset of each cutter is controlled aiming at difficult-to-machine materials (such as 30 CrMnSiA), so that the machining process is more stable, and the cutter tooth breakage caused by large cutting allowance and overlarge cutting force can be effectively avoided; aiming at deep hole machining, the offset of each cutter is adjusted, the cutter back-off condition caused by the fact that the working length of the boring cutter 8 is large and the rigidity of the cutter is insufficient can be effectively avoided, and the machining precision of the part 1 is guaranteed.

The above description is only a preferred embodiment of the present invention, and is not intended to limit the present invention in any way, and all simple modifications and equivalent variations of the above embodiments according to the technical spirit of the present invention are included in the scope of the present invention.

Claims

1. A boring method of an elliptical hole of a bushing is characterized in that a machining coordinate system is established by taking the center of the elliptical hole of the bushing as an original point, and a boring cutter conducts multiple equidistant offset machining in the forward direction or the reverse direction of a machining direction from the original point until a machining end point stops;

establishing a machining coordinate system by taking the center of the elliptical hole of the short bushing as an original point, and respectively carrying out upward equidistant offset on the circle center and downward equidistant offset on the circle center for a plurality of times by the boring cutter along the Y direction of the machining coordinate system until end points at two ends of the major axis of the elliptical hole are machined;

the total offset of the circle center which is equidistantly shifted upwards and the circle center which is equidistantly shifted downwards is respectively 1mm, and the circle center is equidistantly shifted upwards for 5 times and the circle center is equidistantly shifted downwards for 5 times;

when a long bush is machined, the working length L of the boring cutter is greater than the length H of the bush.