Design method of screw compressor rotor profile processing universal milling cutter structure

Abstract

The application relates to the technical field of rotor profile processing, in particular to a design method of a general milling cutter structure for screw compressor rotor profile processing, which can improve the universality of the milling cutter, reduce the production cost, determine the milling cutter diameter according to the machine tool interference, then calculate the blade edge profile according to the rotor end face profile, the lead and the milling cutter diameter, determine the maximum back surface rotary diameter d2 of the blade according to the blade edge profile, the blade thickness and the relief angle, take the overlapping area of all blade edge profiles as the reference profile a of the cutter body design, offset the reference profile a inward by 1-2 millimeters smaller than the maximum back surface rotary diameter d2 of the blade back surface, obtain the cutter body rotary generatrix b, and take the width of the widest one of all blade edge profiles as the common width c of the blade design.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of rotor profile processing, in particular to a design method of a universal milling cutter structure for screw compressor rotor profile processing. BACKGROUND

[0002] The finishing of the rotor profile of a screw compressor is completed by using a custom-shaped milling cutter, and the special-shaped milling cutter is generally composed of a cutter body, a cutter blade, a wedge block, a left pressing plate, a right pressing plate and various fastening screws. The curved surface profile shape of the cutter blade and the cutter body is determined by the rotor profile, so that a corresponding special-shaped milling cutter usually needs to be designed for each rotor profile. The manufacturing cost of a pair of male and female rotor special-shaped milling cutters is different, and is several ten thousand yuan to one hundred thousand yuan. If the rotor of the profile has a low processing frequency, the design of the milling cutter for the rotor of the profile will inevitably increase the production cost. SUMMARY

[0003] In order to solve the problems of poor universality and high production cost of the milling cutter, the application provides a design method of a universal milling cutter structure for screw compressor rotor profile processing, which can improve the universality of the milling cutter and reduce the production cost.

[0004] The technical scheme is as follows: a design method of a universal milling cutter structure for screw compressor rotor profile processing, the diameter of the milling cutter is determined according to the interference of the machine tool, then the blade profile of the cutter blade is calculated according to the rotor end face profile, the lead and the diameter of the milling cutter, the maximum back surface rotating diameter d2 of the cutter blade is determined according to the blade profile, the thickness of the cutter blade and the relief angle, and the method comprises the following steps:

[0005] (1) the blade profiles of the cutter blades calculated according to different rotor end face profiles are placed in the same coordinate system, the overlapping area of all the blade profiles is taken as the reference profile a of the cutter body design, the reference profile a is inwardly offset to the cutter body rotating diameter which is 1-2 millimeters smaller than the maximum back surface rotating diameter d2 of the cutter blade, the cutter body rotating generatrix b is obtained, and the width of the widest one of all the blade profiles is taken as the common width c of the cutter blade design;

[0006] (2) the profiles and widths of the cutter body and the wedge block need to be designed according to the rotating generatrix b and the common width c, when the width of the blade profile is less than the common width c after the blade profile is determined, the width should be extended to the common width c, and the extended part is recessed for avoidance;

[0007] (3) a cutter pad is added to the back surface of the cutter blade, the width of the cutter pad is consistent with the common width c, the blade profile is inwardly offset to obtain the cutter pad curved surface profile, and the maximum rotating diameter d1 of the cutter pad should be 1-2 millimeters smaller than the maximum back surface rotating diameter d2 of the cutter blade;

[0008] (4) the left and right pressing plates and the various fastening screws are designed to remain unchanged, when the rotor of different profiles is processed, the corresponding type of cutter blade and cutter pad can be installed.

[0009] With this invention, the blade profile is determined by the rotor profile and cannot be universally applied, but other parts such as the blade body can be designed to be universal. When machining rotors with different profiles, only the blade and the corresponding blade pad need to be replaced, which effectively reduces production costs. Attached Figure Description

[0010] Figure 1 This is a schematic diagram of the outline design of the blade body of the present invention;

[0011] Figure 2 This is a schematic diagram of the diameter of rotation;

[0012] Figure 3 for Figure 2 Enlarged view of point E in the middle;

[0013] Figure 4 A schematic diagram of the large blade assembly;

[0014] Figure 5 for Figure 4 Sectional view along the AA direction;

[0015] Figure 6 A schematic diagram of the blade assembly;

[0016] Figure 7 for Figure 6 Cross-sectional view along the BB direction;

[0017] Figure 8 This is a schematic diagram of the blade body structure. Detailed Implementation

[0018] See Figures 4 to 8 As shown, the milling cutter includes a cutter body 1, on which a cutting tool mounting port 2 is provided. A wedge block 3, a cutting tool 4, and a cutting tool pad 5 are installed in the cutting tool mounting port 2. A left pressure plate 7 and a right pressure plate 8 are respectively provided on both sides of the cutting tool 4 and the cutting tool pad 5 and are fixed to the cutter body 1 by screws 6. The left pressure plate 7 and the right pressure plate 8 are used to ensure the consistency of the cutting tool pad 5 and the cutting tool 4 in the left and right directions in the cutting tool mounting port 2, and are pressed together by the wedge block 3.

[0019] See Figures 1 to 3 As shown, a design method for a universal milling cutter structure for machining the rotor profile of a screw compressor includes the following steps:

[0020] (1) According to the interference of machine tool, the milling cutter diameter is determined, then the blade profile is calculated according to the rotor end face profile, lead and milling cutter diameter, and then the maximum back surface rotation diameter d2 of the blade is determined according to the blade profile, blade thickness and back angle. The blade profile calculated according to different rotor end face profiles is placed in the same coordinate system, the overlapping area of all blade profiles is taken as the reference profile a of the cutter body design, the reference profile a is offset inward to the cutter body rotation diameter which is 1-2mm smaller than the maximum back surface rotation diameter d2 of the blade, and the cutter body rotation generatrix b is obtained, and the width of the widest blade profile is taken as the common width c of the blade design;

[0021] (2) The profiles and widths of the cutter body and wedge block need to be designed according to the rotation generatrix b and the common width c. When the width of the blade profile is less than the common width c, the width should be extended to the common width c, and the extended part should be recessed for avoidance;

[0022] (3) A tool pad is added to the back surface of the blade, the width of the tool pad is consistent with the common width c, the blade profile is offset inward to obtain the tool pad curved surface profile, and the maximum rotation diameter d1 of the tool pad should be 1-2mm smaller than the maximum rotation diameter d2 of the back surface of the blade;

[0023] (4) The left and right pressure plates and each fastening screw remain unchanged, and when machining different profile rotors, the corresponding type of blade and tool pad can be installed.

Claims

1. A design method of a screw compressor rotor profile processing universal milling cutter structure, the universal milling cutter structure comprising a cutter body and a cutter pad, the cutter body being provided with a blade mounting port, a wedge and a blade being mounted in the blade mounting port, left and right pressure plates being respectively provided on both sides of the blade and being fixed on the cutter body through screws, the blade being arranged between the cutter pad and the wedge, the wedge pressing the blade and the cutter pad tightly, the cutter body and the wedge being matched as universal parts, and the blade and the cutter pad being matched as special parts; a milling cutter diameter is determined according to a machine tool interference condition, then a blade edge profile is calculated according to a rotor end face profile, a lead and the milling cutter diameter, a maximum rotary diameter d2 of a back surface of the blade is determined according to the blade edge profile, a blade thickness and a relief angle, and the method is characterized in that, It includes the following steps: (1) Put the blade edge profile calculated according to different rotor end face type line in the same coordinate system, take the overlapping area of all blade edge profiles as the reference profile a of the cutter body design, offset the reference profile a inward to the cutter body revolution diameter which is 1~2mm smaller than the maximum revolution diameter d2 of the blade back surface, get the cutter body revolution generatrix b, take the width of the widest one of all blade edge profiles as the common width c of the blade design; (2) The profiles and widths of the cutter body and wedge block need to be designed according to the revolution generatrix b and the common width c, after the blade edge profile is determined, if its width is less than the common width c, the width should be extended to the common width c, and the extended part should be recessed for avoidance; (3) Increase the cutter pad on the blade back surface, the cutter pad width is consistent with the common width c, offset the blade edge profile inward to get the cutter pad curved surface profile, the maximum revolution diameter d1 of the cutter pad should be 1~2mm smaller than the maximum revolution diameter d2 of the blade back surface; (4) The left and right pressure plates and each fastening screw remain unchanged, when machining different profile rotors, install the corresponding type of blade and cutter pad.

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