阅读说明：本技术 一种叶轮的高速铣粗加工方法 (High-speed rough milling method for impeller ) 是由 刘振 仝周进 韩威 陆德峰 于 2020-07-02 设计创作，主要内容包括：本发明公开了一种叶轮的高速铣粗加工方法,包括以下步骤：模型分析-刀具选择-编程模型设计-程序轨迹规划-参数收集调整；该方法通过设计一种全新的锥度铣刀配合现有的CAM软件中的高速摆线铣,可以使叶轮的空间狭窄区域使用高速摆线铣进行加工,解决了现有使用球头铣刀分层加工产生的大量刀具消耗及加工时间,也解决了普通铣刀进行摆线加工无法进入狭窄区域的难题。(The invention discloses a high-speed rough milling method for an impeller, which comprises the following steps: model analysis, tool selection, programming model design, program trajectory planning and parameter collection and adjustment; the method can enable the space narrow region of the impeller to be processed by using the high-speed cycloid milling machine by designing a brand-new taper milling cutter to be matched with the high-speed cycloid milling machine in the existing CAM software, solves the problems that a large amount of cutter consumption and processing time are generated by using the existing ball-end milling cutter for layered processing, and also solves the problem that the cycloid processing of the common milling cutter cannot enter the narrow region.)

1. A high-speed rough milling machining method for an impeller is characterized by comprising the following steps:

step 1: and (3) analyzing a model: analyzing an impeller model to determine the diameter size, the type and the number of the blades of the impeller, measuring the minimum distance and the maximum opening distance between the two blades, measuring the maximum height of the blades, and dividing a rough machining slotting region of the impeller into a wide region and a narrow region by determining parameters of the characteristics of the impeller;

step 2: selecting a cutter: selecting cutting tools of different diameters by dividing a rough machining grooving area;

and step 3: designing a programming model: after the tool is selected, reasonable programming design needs to be carried out on the processing program track, and when rough machining is carried out, the processing mode of layered milling cannot be used, and fixed-axis or form cycloid milling or high-speed milling needs to be compiled;

and 4, step 4: planning a program track: during rough machining, an auxiliary curve is required to be drawn to split a machining area, and rough machining program track planning is realized;

and 5: parameter collection and adjustment: and performing trial cutting test on the optimized machining program, and adjusting parameters according to the vibration amplitude fed back by the machine tool so as to achieve the purpose of stable cutting.

2. The high-speed rough milling machining method for the impeller according to claim 1, characterized in that: in the step 1, the rough machining slotting region of the impeller is reasonably divided into the following rules: the region which can be processed and has the mounting overhang length of the cutter less than 4 times of the diameter of the cutter is a wide region; the region outside the wide region is a narrow region, and a tool having an overhang length of less than 4 times the diameter is selectively attached to each region.

3. The high-speed rough milling machining method for the impeller according to claim 1, characterized in that: and 2, using a fillet milling cutter for a wide area and using a taper fillet milling cutter for a narrow area.

4. The high-speed rough milling machining method for the impeller according to claim 1, characterized in that: in the step 4, when programming, the fixed axis cycloid MILLING of the NX software cannot directly program the model of the impeller, and some auxiliary curved surfaces are needed to be divided into regions, and a cycloid MILLING rough machining command ADAPTIVE _ MILLING used in the NX software can directly select parts and blanks, and directly generate a machining program after inputting cutting parameters.

5. The high-speed rough milling machining method for the impeller according to claim 1, characterized in that: in the step 5, according to different working states of each five-axis machining device, different main shaft power, linear shaft power and rotating shaft power of each five-axis machining device, different tool shank size of the main shaft and different holding rigidity of the impeller, dynamic adjustment of cutting parameters is needed, the cutting parameters are recommended parameters, information such as machine tool vibration is collected during trial cutting machining of the machine tool, adjustment and solidification are carried out, and stable machining parameters are formed.

Technical Field

The invention relates to the technical field of impeller blade disc machining, in particular to a high-speed rough milling machining method for an impeller.

Background

In the fields of turbomachinery and aerospace, centrifugal impellers and blisks of compressors are increasingly popularized, the industry is developing the cost and efficiency of propelling the compressors, and how to rapidly produce high-quality products is a technical problem worth deep thinking by the personnel in the industry; at present, various machining schemes of the centrifugal impeller exist, such as a ball end milling cutter layering rough machining technology, a plunge milling machining technology, an electrolytic machining technology and the like; however, the existing technical scheme can not process narrow areas, and the cutter consumption is large, and the working efficiency is low.

Disclosure of Invention

The invention aims to provide a high-speed rough milling method for an impeller, which aims to solve the technical problems that a narrow area cannot be machined and the cutter consumption is large and the working efficiency is low in the prior art.

In order to achieve the aim, the invention provides a high-speed rough milling method for an impeller, which comprises the following steps:

step 1: and (3) analyzing a model: analyzing an impeller model to determine the diameter size, the type and the number of the blades of the impeller, measuring the minimum distance and the maximum opening distance between the two blades, measuring the maximum height of the blades, and dividing a rough machining slotting region of the impeller into a wide region and a narrow region by determining parameters of the characteristics of the impeller;

step 2: selecting a cutter: selecting cutting tools of different diameters by dividing a rough machining grooving area;

and step 3: designing a programming model: after the selection of the cutter is finished, the processing program track needs to be reasonably designed, and during rough processing, the processing mode of layered milling cannot be used, and cycloid milling or high-speed milling in a fixed-axis form needs to be compiled;

and 4, step 4: planning a program track: during rough machining, an auxiliary curve is required to be drawn to split a machining area, and rough machining program track planning is realized;

and 5: parameter collection and adjustment: and performing trial cutting test on the optimized machining program, and adjusting parameters according to the vibration amplitude fed back by the machine tool so as to achieve the purpose of stable cutting.

Further, the reasonable dividing rule of the rough machining grooved area of the impeller in the step 1 is as follows: the region which can be processed and has the mounting overhang length of the cutter less than 4 times of the diameter of the cutter is a wide region; the region outside the wide region is a narrow region, and a tool having an overhang length of less than 4 times the diameter is selectively attached to each region.

Further, in the step 2, a radius mill is used for a wide area, and a taper radius mill is used for a narrow area.

Further, in the step 4, when programming, the fixed axis cycloid MILLING of the NX software cannot directly use the model of the impeller to perform direct programming, and some auxiliary curved surfaces are needed to be made on the model to perform area division;

further, in the step 5, according to different working states of each five-axis machining device, different spindle powers, linear axis powers and rotating axis powers of each five-axis machining device, different tool shank sizes of the spindles and different holding rigidity of the impellers, dynamic adjustment of cutting parameters is needed, the cutting parameters should be recommended parameters, information such as machine tool vibration and the like is collected during trial cutting machining of the machine tool, adjustment and solidification are carried out, and stable machining parameters are formed.

Compared with the prior art, the invention has the following beneficial effects: according to the high-speed rough milling method for the impeller, the brand-new taper milling cutter is designed to be matched with the high-speed cycloid milling cutter in the existing CAM software, so that the space narrow area of the impeller can be processed by using the high-speed cycloid milling cutter, the problems that a large amount of cutters are consumed and the processing time is consumed due to the fact that existing ball head milling cutters are used for layered processing, and the problem that ordinary milling cutters cannot enter the narrow area when cycloid processing is conducted are solved.

Drawings

FIG. 1 is a schematic structural view of an impeller;

FIG. 2 is a schematic view of a free-form surface impeller;

FIG. 3 is a schematic view of a ruled surface impeller;

FIG. 4 is a sectional view of a rough machining area of the impeller of the present invention;

FIG. 5 is a schematic view of the broad area tool selection for rough machining of the impeller of the present invention;

FIG. 6 is a schematic view of the present invention showing the selection of a tool for rough machining of a narrow region of an impeller;

FIG. 7 is a drawing of a custom taper mill selected for use in a confined area according to the present invention;

FIG. 8 is a schematic diagram of an auxiliary body in the programming software of the present invention;

description of reference numerals: 1-main blade, 2-trailing edge, 3-splitter blade, 4-blade tip, 5-ruled surface parameter line, 6-leading edge, 7-runner surface, 8-blade back arc, 9-blade inner arc, 10-free curved surface blade arc and 11-ruled surface blade arc.

Detailed Description

The following further describes embodiments of the present invention with reference to the drawings. It should be noted that the description of the embodiments is provided to help understanding of the present invention, but the present invention is not limited thereto. In addition, the technical features involved in the embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

Referring to fig. 1 to 8, a high-speed rough milling method for an impeller according to a preferred embodiment of the present invention includes the following steps:

step 1: and (3) analyzing a model: analyzing an impeller model to determine the diameter size, the type and the number of the blades of the impeller, measuring the minimum distance and the maximum opening distance between the two blades, measuring the maximum height of the blades, and dividing a rough machining slotting region of the impeller into a wide region and a narrow region by determining parameters of the characteristics of the impeller; in the step 1, the rough machining slotting region of the impeller is reasonably divided into the following rules: the region which can be processed and has the mounting overhang length of the cutter less than 4 times of the diameter of the cutter is a wide region; the region outside the broad region is narrow region, the structure according to the impeller to selecting the cutter that installation overhang length is less than 4 times footpath in each region, need divide the whole runner machining region of impeller, regional division's purpose is in order to choose for use more suitable processing cutter, compare in the unified processing cutter who chooses for use a specification, divide the region and choose the cutter to reduce the consumption of cutter, when using great cutter, can increase cutting speed and cutting output, improved machining efficiency. The rough machining of the free-form surface and the rough machining of the ruled surface can be the same parameters and the same machining method, but the finish machining is different, the finish machining of the free-form surface must use a ball-end milling cutter to carry out point milling (divided into multiple layers of milling), the impeller structure of the ruled surface is relatively simple, the rough milling machining has smooth change of a cutter shaft track due to good consistency of the curvature direction of the curved surface, the finish machining can use a side edge of the milling cutter to carry out finish machining, and the machining efficiency is very high;

step 2: selecting a cutter: selecting cutting tools of different diameters by dividing a rough machining grooving area; referring to fig. 4, an area 1 and an area 2 may be respectively selected to be rough machined by using a large-diameter end mill or a taper mill, a standard end mill with specifications of D12\ D10\ D8\ D6 is generally adopted, an area 3 may be selected to be a small-diameter end mill, if the minimum area of the area is less than 6mm, and the blade height is greater than 35mm, the common end mill is not suitable for use, and abnormal damage of the tool is caused by too long overhang of the tool, in the present invention, a new tool selection scheme is proposed, which can perfectly avoid the disadvantage, as shown in fig. 7, the new taper mill is specially designed according to the size of each impeller, and the design characteristics are as follows: the diameter of the milling cutter is determined by the minimum distance between the blades (for example: the minimum distance between the blades is 8mm, then the design size of the taper milling cutter should be less than 8mm, and is optimally 5-6mm), the taper of the milling cutter is determined by the width of the blade close to the blade tip and the height of the blade (for example: the height of the blade is 45mm, the width of the blade is 16mm, then the design taper length of the taper milling cutter is 45-55mm, and the maximum diameter of the taper is 12mm), and the advantages of the brand-new cutter scheme are that: the narrowest region of the blade can be machined by using the working mode of the end mill, and the machining efficiency and the machining service life of the cutter are remarkably improved because the cutter is designed in a taper manner and has better rigidity;

and step 3: designing a programming model: after the selection of the cutter is finished, the processing program track needs to be reasonably designed, and during rough processing, the processing mode of layered milling cannot be used, and cycloid milling or high-speed milling in a fixed-axis form needs to be compiled; as shown in fig. 5 and 6, after the tool selection is completed, the machining program trajectory needs to be reasonably designed, and when the end mill and the taper mill are used for rough machining, the machining mode of the layered mill cannot be used, and a fixed-axis or linkage-type cycloid mill or high-speed mill needs to be programmed, because the impeller is usually made of stainless steel or titanium alloy, the material characteristics are as follows: the heat conductivity is poor, concentrates on the knife tip region easily, leads to the cutter premature failure, and according to this characteristic, the cycloid mills and uses the side sword to carry out high-speed processing, and the big depth of cut of side sword, the small cut is wide, and high speed can be fast let the cutting take away the heat, and the life of cutter is very long, and stainless steel and titanium alloy's high-speed cycloid rough machining's suggestion parameter is:

the linear velocity is 80 meters;

cutting depth 1 x D

Width of cut 0.1 × D

The end mill as in 12: 80 × 1000/3.14/12 ═ 2123, cut depth 12mm, cut width 1.2 mm;

and 4, step 4: planning a program track: during rough machining, an auxiliary curve is required to be drawn to split a machining area, and rough machining program track planning is realized; referring to fig. 8, according to different CAM software used, for example, fixed axis cycloid MILLING of NX software, when programming, the model of the impeller cannot be directly programmed, and some auxiliary curved surfaces are needed to be made on the model for area division, and a cycloid MILLING rough machining command ADAPTIVE _ MILLING used in the NX software can directly select parts and blanks, and directly generate a machining program after cutting parameters are input;

and 5: parameter collection and adjustment: trial cutting test is carried out on the optimized machining program, and parameters are adjusted according to the vibration amplitude fed back by the machine tool so as to achieve the purpose of stable cutting; the parameters are adjusted according to different working states of each five-axis machining device, different main shaft power, different linear shaft power and different rotating shaft power of each five-axis machining device, different tool shank sizes of the main shaft and different holding rigidity of the impeller, the cutting parameters need to be dynamically adjusted and should be recommended, and the information such as machine tool vibration and the like is collected during trial cutting machining of the machine tool, then the adjustment and the solidification are carried out to form stable machining parameters.

From the above description, it can be seen that the above-described embodiments of the present invention achieve the following technical effects: the method can enable the space narrow region of the impeller to be processed by using the high-speed cycloid milling machine by designing a brand-new taper milling cutter to be matched with the high-speed cycloid milling machine in the existing CAM software, solves the problems that a large amount of cutter consumption and processing time are generated by using the existing ball-end milling cutter for layered processing, and also solves the problem that the cycloid processing of the common milling cutter cannot enter the narrow region.

The embodiments of the present invention have been described in detail with reference to the accompanying drawings, but the present invention is not limited to the described embodiments. It will be apparent to those skilled in the art that various changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, and the scope of protection is still within the scope of the invention.