A high-efficiency milling method for an aluminum alloy impeller

Abstract

The application provides a high-efficiency milling method for an aluminum alloy impeller, which comprises the following steps: firstly, slotting the impeller by using a taper ball end mill; secondly, side milling rough machining the impeller by using a side blade of the taper ball end mill; thirdly, semi-finishing and finishing machining the blade by using the side blade of the taper ball end mill; and finally, machining the fillet angle and the flow channel of the blade, so that the machining efficiency of the aluminum alloy impeller is greatly improved.

Description

TECHNICAL FIELD

[0001] The application relates to a compressor impeller machining method, in particular to a high-efficiency milling machining method for an aluminum alloy impeller. BACKGROUND

[0002] At present, in the field of new energy, the field of automobile turbochargers, the field of aerospace engines and the field of industrial compressors, the quantity of compressor impellers is increasing with the increasing market demand. The whole machining impeller has good size precision, good surface roughness, high compression efficiency, long service life and easy maintenance, so more and more compressor impellers use the whole machining impeller technology. However, due to the complex structure of the whole impeller, the twisted blades also lead to difficult machining. The rough machining process is the longest process in the compressor impeller machining process. The commonly used rough machining methods mainly include 1, using a cycloid milling machine for rough machining; or 2, using a large-diameter milling cutter for rough machining. Although the rough machining of the cycloid milling machine and the large-diameter milling cutter can improve the overall machining efficiency of the impeller to a certain extent, it still cannot meet the high demand for the overall machining efficiency of the impeller. SUMMARY

[0003] In view of the problem that the existing compressor impeller machining method cannot meet the demand for the overall machining efficiency of the impeller by using the rough machining method of the cycloid milling machine or the large-diameter milling cutter, the application provides a high-efficiency milling machining method for an aluminum alloy impeller, which greatly improves the machining efficiency of the compressor impeller.

[0004] The technical scheme is as follows: a high-efficiency milling machining method for an aluminum alloy impeller, characterized by comprising the following steps: S1, slotting, using a tapered ball nose milling cutter to perform full tool machining on the impeller in a layered slotting machining mode, and reserving a margin of 0.1mm to 1mm on the side and bottom surfaces of the impeller blade after slotting;

[0005] S2, side blade rough milling, using the side blade of the tapered ball nose milling cutter to perform side blade machining on the impeller, the side blade machining adopts a mode of large cutting depth and small cutting width, and a wavy cutting track is used to perform machining starting from the middle position of the impeller after slotting, and a margin of 0.1mm to 1mm is reserved on the impeller blade after the side blade rough milling;

[0006] S3, semi-fine milling of the blade profile, using the side blade of the tapered ball nose milling cutter to perform side milling machining on the impeller, the side milling machining adopts a mode of large cutting depth of the side blade of the tapered ball nose milling cutter, and a margin of 0.05mm to 0.4mm is reserved on the impeller blade after the semi-fine milling of the blade profile;

[0007] S4, the profile of the impeller is precisely milled by using the side edge of the taper ball end mill, and the side edge of the taper ball end mill is processed and formed in one pass around the profile of the impeller;

[0008] S5, the fillet of the root of the impeller blade is processed by using the taper ball end mill, and the diameter of the ball head part of the taper ball end mill is equal to the diameter of the fillet of the root of the impeller blade;

[0009] S6, the flow channel of the impeller blade is precisely milled by using the taper ball end mill, and the precisely milled flow channel is processed by using a back-shaped cutting track from the middle position of the flow channel of the impeller blade.

[0010] Further features are that in S1, the diameter of the impeller is 6mm to 600mm, the taper ball end mill comprises a ball head part, a side edge part and a shank part, the diameter of the taper ball end mill is smaller than the minimum space distance between the adjacent two blades of the impeller, and the length of the side edge part of the taper ball end mill is greater than the width of the blade of the impeller;

[0011] In S1, the depth of each slot of the taper ball end mill is 3mm to 25mm, the linear speed of the taper ball end mill is 10m per minute to 200m per minute, and the feed per tooth is 0.03mm to 0.1mm;

[0012] In S2, the cutter depth of the taper ball end mill is 30mm, the linear speed of the cutting is 100m per minute to 200m per minute, and the cutting width per tooth is 0.1 times the diameter of the side edge part of the taper ball end mill;

[0013] In S4, the taper ball end mill is prone to chatter when machining to the leading edge corner position of the blade of the impeller, so the taper ball end mill is used to perform plunge milling to the leading edge position of the blade of the impeller, and then the side edge of the taper ball end mill is used to precisely mill the surface of the blade of the impeller.

[0014] After the above structure is adopted, the taper ball end mill is used to first groove the impeller, then the side edge of the taper ball end mill is used to side mill the blade, then the side edge of the taper ball end mill is used to semi-precisely mill and precisely mill the blade, and finally the fillet angle and the flow channel of the blade are machined, so that the machining efficiency of the aluminum alloy impeller is greatly improved. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 is a schematic structural view of the compressor impeller of the application;

[0016] Figure 2 is a schematic structural view of the layered slotting track simulation of the application;

[0017] Figure 3 This is a schematic diagram of the structure of the present invention, which uses the side cutting edge of a tapered ball end mill to side-mill impeller blades;

[0018] Figure 4 This is a schematic diagram of the simulated zigzag cutting trajectory of the present invention;

[0019] Figure 5 This is a schematic diagram of the tapered ball end mill of the present invention. Detailed Implementation

[0020] like Figure 1 The image shows the external structure of a common compressor impeller. The impeller is made of aluminum alloy and its diameter ranges from 6 mm to 600 mm.

[0021] The high-efficiency milling method for the compressor impeller includes the following steps:

[0022] S1. Grooving: Use a tapered ball end mill to perform full-cut machining on the impeller using a layered grooving method, such as... Figure 2 As shown, it simulates the groove region between the blades of an impeller. The baffles 1 on both sides represent the blades, and the longitudinally arranged solid lines 2 represent the trajectory of the tapered ball end mill during the grooving process, i.e., milling layer by layer along the depth direction at the corresponding position of the groove. Since a tapered ball end mill is used for grooving, different models of tapered ball end mills are selected for different models of compressor impellers. Because aluminum alloy has the characteristic of sticking to the cutter, it is very easy to generate built-up edge, so the tapered ball end mill needs to have good... For good chip removal, the depth of each groove should be between 3mm and 25mm, the grooving speed should be between 10m and 200m per minute, and the feed per tooth should be between 0.03mm and 0.1mm. The variation of cutting parameters mainly depends on the design of the tool diameter and taper. A small tool diameter and taper will result in poor tool rigidity, and a lower linear speed should be used. Conversely, a larger tool diameter and taper will result in good tool rigidity, and a higher linear speed can be used. After grooving, a margin of 0.1mm to 1mm should be reserved on the side and bottom surface of the impeller blades.

[0023] S2. After rough milling with the side cutter, the material in the middle of the impeller blades is removed, such as... Figure 3 The impeller blades are machined using the side cutting edge of a tapered ball end mill. Side milling employs a large depth of cut and small width of cut method. The depth of cut of the tapered ball end mill is 30mm, the cutting speed is between 100m / min and 200m / min, the width of cut per pass is 0.1 times the diameter of the tapered ball end mill, and the feed rate is between 0.08mm and 0.2mm per tooth. Figure 4As shown, it simulates the groove area between the blades of the impeller, 3 is the side edge rough milling processing track, when processing, the corresponding middle position 31 of the impeller blade after slotting to the edge position 32 stop, adopt the processing of back-shaped cutting track, avoid the empty walking of the cutter, while ensuring the direction of the milling, improve the efficiency of the walking, the impeller blade after the side edge rough milling processing reserves 0.1mm to 1mm of the margin;

[0024] S3, semi-finish milling blade shape, remove the residual margin of the blade surface after rough milling the blade shape of the impeller, ensure the uniformity of the margin of the blade shape surface, create conditions for subsequent finish milling blade shape, use the side edge of the taper ball end mill to process the impeller by side milling, the cutter cutting depth is 30mm, use the way of large cutting depth of the side edge, the impeller blade after semi-finish milling blade shape processing reserves 0.05mm to 0.4mm of the margin;

[0025] S4, finish milling blade shape, finish milling blade shape adopts side edge finish milling processing, uses the side edge of the taper ball end mill to form a contour around the blade shape, uses the side edge of the taper ball end mill to finish mill the impeller blade, the cutter cutting depth is 30mm, when finish milling, the taper ball end mill mills along the blade, when the taper ball end mill reaches the leading edge position 11 of the impeller blade, blade fluttering is easy to occur, at this time, adjustment and solution can be made by way one, reducing the cutting speed and feed rate, when adjustment of cutting speed and feed cannot be solved, way two is adopted, that is, the finish milling program needs to be adjusted, first, the leading edge position 11 of the impeller blade is inserted and finished in place, and then the side edge of the taper ball end mill is used to finish mill the surface of the impeller blade;

[0026] S5, finish milling round corner, using the taper ball end mill to process the round corner of the root of the impeller blade, the diameter of the ball head part of the taper ball end mill is equal to the diameter of the round corner of the root of the impeller blade, the contact surface of the round corner of the taper ball end mill and the round corner of the impeller blade is circular arc contact, the round corner contact surface of the taper ball end mill is larger, so the processing speed and feed rate need to be reduced to avoid surface processing vibration during round corner processing;

[0027] S6, finish milling flow channel, using the taper ball end mill to finish mill the flow channel of the impeller blade, finish milling flow channel from the middle position of the impeller blade into the flow channel uses the same back-shaped cutting track as in step S2 for processing, which also improves the processing efficiency, and the cutting method of one-way walking can also be used, although the processing time will increase when walking in one direction, the surface quality of the flow channel will be improved, because the one-way walking ensures consistent cutting direction and cutting force.

[0028] Further, the taper ball end mill used in each of the above steps is the same, such as Figure 5As shown, the taper ball end mill 4 includes a ball head part 41, a side blade part 42 and a shank part 43, when selecting the taper ball end mill before machining, the diameter of the taper ball end mill should be selected to be smaller than the minimum space distance between two adjacent blades of the impeller, and the length of the side blade part of the taper ball end mill should be greater than the width of the impeller blade.

[0029] Specifically, when a R2*5 degree taper ball end mill with a shank length of 10mm and 2 blades is selected.

[0030] When grooving, the cutting line speed of the taper ball end mill is 100 meters per minute, which is converted into the spindle speed of the five-axis linkage machine tool according to the formula VC=π*d*S / 1000, S=VC*1000 / (π*d)=100*1000 / 3.14 / 4=7961, the speed is S=7961, the feed per tooth is 0.03, the feed F=477, and the cutter depth is 10mm;

[0031] When side blade rough milling, the cutting speed of the taper ball end mill is 100 meters per minute, which is converted into the spindle speed of the machine tool according to the formula S=VC*1000 / (π*d)=100*1000 / 3.14 / 4=7961, the speed is S=7961, the feed per tooth is 0.1, the feed F=1592, and the cutter depth is 30mm;

[0032] When semi-finishing the blade profile and finishing the blade profile, the cutting speed of the taper ball end mill is 50 meters per minute, which is converted into the spindle speed of the machine tool according to the formula S=VC*1000 / (π*d)=50*1000 / 3.14 / 4=3980, the speed is S=3980, the feed per tooth is 0.05, the feed F=796, and the cutter depth is 30mm. When finishing the blade profile, the cutting speed and the feed are reduced, that is, the speed S=3980 and the feed F=796 are reduced, for example, by 0.2 times, which is 3980-3980*0.2=3184 and 796-796*0.2=636. As a result, the speed S=3184 and the feed F=636.

[0033] The cutting parameters for finishing the runner are the same as those for side blade rough milling.

[0034] The above is only a preferred specific embodiment of the present application, but the protection scope of the present application is not limited thereto. Any changes or replacements within the technical scope disclosed by the present application can be easily thought of by those skilled in the art, which should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A high efficiency milling method of an aluminum alloy impeller, characterized by, It comprises the following steps: S1, slotting, using a tapered ball end mill to adopt layered slotting processing mode for full tool machining of the impeller, and reserving 0.1mm to 1mm margin on the side and bottom surface of the impeller blade after slotting; The tapered ball end mill includes a ball head part, a side edge part and a tool shank part, the diameter of the tapered ball end mill is smaller than the minimum space distance between the adjacent two blades of the impeller, and the length of the side edge part of the tapered ball end mill is greater than the width of the impeller blade; S2, side edge rough milling, using the side edge of the tapered ball end mill to process the side edge of the impeller, the side edge processing adopts a large cutting depth and a small cutting width, and the middle position of the impeller after slotting is processed using a hui-zi-shaped cutting track, and the impeller blade reserves 0.05mm to 2mm margin after the side edge rough milling processing; S3, semi-finish milling of blade type, using the side edge of the tapered ball end mill to process the side milling of the impeller, the side milling processing adopts a large cutting depth using the side edge of the tapered ball end mill, and the impeller blade reserves 0.05mm to 0.4mm margin after the semi-finish milling of blade type processing; S4, finish milling of blade type, using the side edge of the tapered ball end mill to process the finish milling of the impeller, and the side edge of the tapered ball end mill processes around the blade type contour of the impeller and forms a one-cut shape; In order to solve the problem that the tapered ball end mill shakes when machining to the leading edge corner position of the impeller blade, the tapered ball end mill first performs plunge milling finish machining on the leading edge position of the impeller blade during machining, and then uses the side edge of the tapered ball end mill to finish mill the surface of the impeller blade after finish machining is in place; S5, finish milling of round corner, using the tapered ball end mill to process the round corner of the root of the impeller blade, and the diameter of the ball head part of the tapered ball end mill is equal to the diameter of the round corner of the root of the impeller blade; S6, finish milling of flow channel, using the tapered ball end mill to finish mill the flow channel of the impeller blade, and the finish milling of flow channel starts from the middle position of the flow channel of the impeller blade and processes using a hui-zi-shaped cutting track.

2. A high efficiency milling method of an aluminum alloy impeller according to claim 1, characterized in that: In S1, the diameter of the impeller is 6mm to 600mm.

3. A method of high efficiency milling of an aluminum alloy impeller according to claim 2, characterized in that: In S1, the slotting depth of each tapered ball end mill is 3mm to 25mm, the linear speed of the tapered ball end mill is 10m to 200m per minute, and the feed per tooth is 0.03mm to 0.1mm.

4. The method of claim 1, wherein: In S2, the cutter depth of the tapered ball end mill is 30mm, the cutting linear speed is 100m to 200m per minute, and the cutting width of each tapered ball end mill is 0.1 times the diameter of the side edge part of the tapered ball end mill.

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