CN109352048B

CN109352048B - Spatial dead axle milling method for integral titanium alloy air compressing impeller

Info

Publication number: CN109352048B
Application number: CN201811516495.8A
Authority: CN
Inventors: 袁列军; 鲁建于; 吴�琳; 赵倩
Original assignee: Chongqing Jiangjin Shipbuilding Industry Co Ltd
Current assignee: Chongqing Jiangjin Shipbuilding Industry Co Ltd
Priority date: 2018-12-12
Filing date: 2018-12-12
Publication date: 2020-08-14
Anticipated expiration: 2038-12-12
Also published as: CN109352048A

Abstract

The invention discloses a space dead axle milling method of an integral titanium alloy compressed air impeller, which comprises the following steps: firstly, roughing an impeller, 1) modeling, determining a cavity structure between adjacent blades and modeling, 2) dividing an area, dividing an impeller blank into a plurality of areas, 3) directionally programming, firstly determining a cutter shaft direction suitable for milling a single area, then fixing the determined cutter shaft direction, programming a feed path suitable for the area in the direction, finally finishing blank milling simulation of the area and processing an actual program suitable for machine tool machining, repeating each area, and finishing the integral roughing of the impeller; step two, finely milling the blade; and step three, finely milling the flow channel.

Description

Spatial dead axle milling method for integral titanium alloy air compressing impeller

Technical Field

The invention belongs to the technical field of integral titanium alloy air compressing impellers, and relates to a space dead axle milling method of an integral titanium alloy air compressing impeller.

Background

In recent years, with the increasing demand of vapor compressor products, how to improve the production efficiency of the products becomes a problem which needs to be solved urgently at present.

The existing milling work of the integral titanium alloy compressed air impeller mainly comprises three steps of rough impeller opening, fine blade milling and fine runner milling, wherein five-axis linkage processing is adopted in the three steps, a cutter shaft continuously swings along with meridian lines or runner lines of the impeller during processing, and cutters with proper sizes are selected in different areas according to the space between adjacent blades so as to complete the integral milling of the impeller. The adoption of the method has the following defects: 1. the feeding parameters are low, in the existing five-axis linkage machining, a cutter shaft continuously swings in space along an impeller meridian or flow channel curve, in the swinging process, instantaneous allowance of a part to be removed constantly provides a space reverse acting force for a machine tool spindle, the larger the feeding parameters are, the larger the reverse acting force is, the allowable safety load of the machine tool spindle is limited, and therefore, in the machining process, the influence of the limitation of a machining mode is caused, particularly, the feeding parameters when an impeller is rough can not be effectively improved, and the production condition that the machining efficiency is low is caused; 2. the cutter cost is high, cutters used in five-axis linkage are affected by continuous reciprocating swing of a space cutter shaft, a bottom cutting edge of the cutter needs to pass through the center, and aiming at the point that the processed impeller is made of titanium alloy, the selected cutter meeting the requirements is an integral hard alloy milling cutter in the previous processing process, the price of the milling cutter is high, more and more cutters are consumed for completing impeller milling along with the increase of the wheel diameter of the integral titanium alloy impeller, and the cutter cost is high.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provides a space dead axle milling method of an integral titanium alloy compressor impeller.

The purpose of the invention is realized as follows: a space dead axle milling method of an integral titanium alloy compressor impeller is characterized by comprising the following steps:

step one, the impeller is opened to be thick,

1) modeling, determining and modeling the cavity structure between adjacent blades,

2) dividing the impeller blank into an upper layer and a lower layer according to the width and depth of the blade opening, dividing the upper layer and the lower layer into a plurality of areas by using the short shunting blades as boundaries, wherein the boundary between the area of the upper layer and the area of the lower layer corresponding to the area of the upper layer is a plane,

3) directional programming, wherein the cutter shaft direction is oriented by being vertical to an interface between the upper layer surface area and the lower layer surface area corresponding to the upper layer surface area, then the determined cutter shaft direction is fixed, a cutting path suitable for the area to be processed is programmed in the direction, finally, blank milling simulation of the area to be processed is completed, and an actual program suitable for machine tool processing is processed,

4) repeatedly performing directional programming on each area of the upper layer and the lower layer to finish the overall roughing of the impeller;

step two, finely milling the blade;

and step three, finely milling the flow channel.

Preferably, in the first step, the upper layer surface and the lower layer surface of the impeller blank are divided into two areas.

Preferably, in the first step, an indexable milling cutter is adopted when the impeller is roughly cut.

Due to the adoption of the technical scheme, the invention has the following beneficial effects: according to the space dead axle milling method of the integral titanium alloy compressed air impeller, the area of the complex curved surface entity allowance is divided, the allowance to be processed of the impeller is converted into simple and regular space-oriented plane processing, the limitation of five-axis linkage on production in the field of impeller roughing is fundamentally eliminated, and the production efficiency is effectively improved; furthermore, the space dead axle milling method of the integral titanium alloy compressed air impeller avoids using a cutter used by five-axis linkage, enlarges the selection range of the cutter and reduces the cutter cost.

Drawings

FIG. 1 is a schematic view of a prior art process;

FIG. 2 is a schematic of the process of the present invention;

FIG. 3 is a schematic representation of modeling in the present invention;

FIG. 4 is a schematic view of the demarcated regions of the present invention;

FIG. 5 is a schematic view of the width of the opening of the vane of the present invention.

Reference numerals

In the attached drawing, 1 is the upper layer of the impeller blank, 2 is the lower layer of the impeller blank, and 3 is the short shunting blade.

Detailed Description

Embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

Referring to fig. 1-5, an embodiment of a method for machining a space fixed-axis milling of an integral titanium alloy compressor impeller comprises the following steps:

step one, the impeller is opened to be thick,

1) modeling, namely determining a cavity structure between adjacent blades and modeling;

according to the consistency of the blades of the compressor impeller, the basic unit of the blank model to be processed is determined to be an open type cavity structure between adjacent blades, only the basic model unit shown in figure 3 needs to be created before processing, and after the subsequent operation of the unit is completed, the integral processing of the complete impeller can be realized through simple indexing rotation.

in this embodiment, the upper layer is divided into a region a and a region b, the lower layer is divided into a region c and a region d, one region corresponds to a machining tool, the larger the tool diameter is, the higher the milling efficiency is, and the maximum tool diameter allowed by one region is proportional to the width of the region, therefore, when dividing the region, the impeller blank is divided into the upper layer and the lower layer according to the width and depth of the blade opening, and then the region is preliminarily divided according to the width of the region, and from the blade opening width schematic diagram of fig. 5, the width of the region at the same position closer to the blade root is smaller, and comparing the positions corresponding to the four regions seen in fig. 4, the opening widths of the four regions are b, a, c and d in turn from large to small.

In fig. 4, the area a corresponds to the upper part of the blade opening, the whole area has a wide width, and a carbide insert cutter with a larger diameter can be used for milling the area, while the area c of the lower layer has a narrower width and a deeper depth because it is close to the blade root, and a cutter with a smaller diameter is required to be used in the processing, and the type of the cutter is preferably a carbide ball cutter.

As can be seen from the position of the middle shunting short blade in fig. 5, the shunting short blade suddenly reduces the width of the opening region of the blade by half, and the width has a cross-over change, so that when the position is taken as the boundary surface of each region in the upper layer and the lower layer, the obvious change caused by the sudden change of the structure of the cutter during the processing of a single region is effectively avoided, the consistency of the cutter path is ensured, and the problem that a plurality of blank cutters are caused to avoid the sudden change of the structure when the cutter is simulated is solved.

3) Directional programming, wherein the cutter shaft direction is oriented by an interface between an upper layer surface area and a lower layer surface area corresponding to the upper layer surface area, then a milling cutter determining the cutter shaft direction is fixed, a feed path suitable for the area to be processed is programmed, finally, blank milling simulation of the area to be processed is completed, and an actual program suitable for machine tool processing is processed,

the directional programming of the region a in fig. 4 is taken as an example for a brief explanation:

firstly, determining the cutter shaft direction of the area a to be processed, namely orientation, and orienting the cutter shaft direction perpendicular to the interface of the area a and the area c, so as to avoid the shielding of the upper edge of the blade in the cutter shaft direction on the root.

Generating a tool path, selecting an indexable milling cutter with a moderate diameter and machining parameters to complete the generation of the machining tool path of the region according to the specific width of the region a after orientation, wherein the generation region of the tool path is limited in the generation process of the tool path, and the tool path is limited in the region through the boundary line of the region during programming.

And (3) performing three-dimensional simulation and post-processing, performing necessary three-dimensional simulation on the machining of the area after the tool path is generated, bringing the tool and a machine tool spindle model into the simulation according to the entity size so as to simulate collision, performing necessary post-processing according to a machine tool system to be machined after the three-dimensional simulation is completed, and applying the program to production.

step two, finely milling the blade;

and step three, finely milling the flow channel.

Finally, it is noted that the above-mentioned preferred embodiments illustrate rather than limit the invention, and that, although the invention has been described in detail with reference to the above-mentioned preferred embodiments, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the scope of the invention as defined by the appended claims.

Claims

1. A space dead axle milling method of an integral titanium alloy compressor impeller is characterized by comprising the following steps:

step one, the impeller is opened to be thick,

step two, finely milling the blade;

and step three, finely milling the flow channel.

2. The method of claim 1 wherein in step one, the upper and lower faces of the wheel blank are each divided into two regions.

3. The method for milling the spatial fixed shaft of the integral titanium alloy compressor impeller according to claim 1, wherein in the first step, an indexable milling cutter is adopted when the impeller is rough.