CN115178782A - Design method of universal milling cutter structure for machining of screw compressor rotor profile - Google Patents

Abstract

The invention relates to the technical field of rotor profile processing, in particular to a design method for a general milling cutter structure for screw compressor rotor profile processing, which can improve the versatility of milling cutters, reduce production costs, and determine the diameter of milling cutters according to machine tool interference conditions , and then calculate the edge profile of the blade according to the rotor end face profile, lead and cutter diameter, and then determine the maximum turning diameter d2 of the back of the blade according to the blade profile, blade thickness, and clearance angle, and take the overlapping area of all blade edge profiles As the reference contour a of the cutter body design, offset the reference contour a inward until the cutter body rotation diameter is 1~2 mm smaller than the maximum rotation diameter d2 of the back of the insert, and the cutter body rotation generatrix b is obtained. The width of a kind is used as the common width c of the blade design.

Description

A design method of general milling cutter structure for screw compressor rotor profile machining

technical field

The invention relates to the technical field of rotor profile processing, in particular to a design method for a general milling cutter structure for screw compressor rotor profile processing.

Background technique

The finishing of the screw compressor rotor profile is completed with a custom-made milling cutter, which is generally composed of a cutter body, a blade, a wedge, a left pressure plate, a right pressure plate and a variety of fastening screws. The shape of the curved contour of the insert and the cutter body is determined by the rotor profile, so it is usually necessary to design a corresponding forming milling cutter for each rotor profile. The manufacturing cost of a pair of yin-yang rotor forming milling cutters ranges from tens of thousands to hundreds of thousands of yuan. If the rotor processing frequency of this type of line is low, designing a milling cutter for it alone will inevitably increase the production cost.

SUMMARY OF THE INVENTION

In order to solve the problems of poor versatility and high production cost of existing milling cutters, the present invention provides a design method for a general milling cutter structure for screw compressor rotor profile machining, which can improve the versatility of milling cutters and reduce production costs.

The technical scheme is as follows: a design method for a general milling cutter structure for screw compressor rotor profile processing, the cutter diameter is determined according to the interference of the machine tool, and then the blade edge of the blade is calculated according to the rotor end face profile, lead and milling cutter diameter. profile, and then determine the maximum turning diameter d2 of the back of the blade according to the profile of the blade, the thickness of the blade, and the clearance angle, which is characterized in that it includes the following steps:

(1) Put the blade edge profiles calculated according to different rotor end face profiles in the same coordinate system, take the overlapping area of all blade edge profiles as the reference profile a for the design of the cutter body, and offset the reference profile a inwards. Set the turning diameter of the cutter body to be 1~2 mm smaller than the maximum turning diameter d2 on the back of the blade, to obtain the turning generatrix b of the cutter body, and take the width of the one with the widest edge profile of all the blades as the common width c of the blade design;

(2) The contour and width of the cutter body and the wedge should be designed according to the rotary generatrix b and the common width c. After the contour of the blade edge is determined, when the width is smaller than the common width c, the width should be extended to the common width c, and the extended part should be recessed. avoid;

(3) Add a shim on the back of the blade. The width of the shim is the same as the common width c. Offset the contour of the blade edge inward to obtain the contour of the shim surface. The maximum turning diameter d1 of the shim should be 1 smaller than the maximum turning diameter d2 on the back of the blade. ~2mm;

(4) The design of the left and right pressure plates and each fastening screw remains unchanged. When processing rotors with different profiles, just install the corresponding type of blade and shim.

After adopting the present invention, the blade profile of the blade is determined by the rotor profile and cannot be used universally, but other parts such as the cutter body can be designed and used for universal use. When machining rotors with different profile lines, only the blade and the corresponding shim need to be replaced. Effectively reduce production costs.

Description of drawings

Fig. 1 is the outline design schematic diagram of the cutter body of the present invention;

Figure 2 is a schematic diagram of the diameter of rotation;

Fig. 3 is the enlarged schematic diagram at E in Fig. 2;

Fig. 4 is a schematic diagram of large blade assembly;

Fig. 5 is the sectional view along A-A in Fig. 4;

Fig. 6 is a schematic diagram of small blade assembly;

Fig. 7 is a sectional view along the direction B-B in Fig. 6;

Figure 8 is a schematic diagram of the structure of the cutter body.

Detailed ways

As shown in Fig. 4 to Fig. 8, the milling cutter includes a cutter body 1, a blade installation port 2 is provided on the cutter body 1, and a wedge block 3, a blade 4, a blade shim 5, a blade 4 and a shim are installed in the blade installation opening 2 5. The left and right pressure plates 7 and 8 fixed on the cutter body 1 by the screws 6 are respectively provided on both sides. Consistent and pressed through wedge 3.

As shown in Figures 1 to 3, a design method for a general milling cutter structure for screw compressor rotor profile machining, which includes the following steps:

(1) Determine the diameter of the milling cutter according to the interference of the machine tool, and then calculate the blade profile of the blade according to the rotor end face profile, lead and cutter diameter, and then determine the maximum turning diameter of the back of the blade according to the blade profile, blade thickness, and clearance angle. d2, place the blade edge contours calculated according to different rotor end face profiles in the same coordinate system, take the overlapping area of all blade edge contours as the reference contour a of the cutter body design, and offset the reference contour a inward Until the turning diameter of the cutter body is 1~2 mm smaller than the maximum turning diameter d2 on the back of the blade, the turning generatrix b of the cutter body is obtained.

(2) The contour and width of the cutter body and the wedge should be designed according to the rotary generatrix b and the common width c. After the contour of the blade edge is determined, when the width is smaller than the common width c, the width should be extended to the common width c, and the extended part should be recessed. avoid;

(3) Add a shim on the back of the blade. The width of the shim is the same as the common width c. Offset the contour of the blade edge inward to obtain the contour of the shim surface. The maximum turning diameter d1 of the shim should be 1 smaller than the maximum turning diameter d2 on the back of the blade. ~2mm;

(4) The design of the left and right pressure plates and each fastening screw remains unchanged. When processing rotors with different profiles, just install the corresponding type of blade and shim.

Claims (1)

1. A design method of a general milling cutter structure for machining a rotor profile of a screw compressor is characterized by comprising the following steps of determining the diameter of a milling cutter according to the interference condition of a machine tool, then calculating the edge profile of a blade according to the end face profile of the rotor, the lead and the diameter of the milling cutter, and then determining the maximum back surface rotation diameter d2 of the blade according to the edge profile, the thickness of the blade and the back angle, wherein the design method comprises the following steps:

(1) Placing blade edge profiles obtained by calculation according to different rotor end face profiles in the same coordinate system, taking the overlapped area of all the blade edge profiles as a reference profile a of cutter body design, inwards biasing the reference profile a until the rotation diameter of the cutter body is 1 to 2 millimeters smaller than the maximum rotation diameter d2 of the back of a blade to obtain a rotation bus b of the cutter body, and taking the width of the widest one of the blade edge profiles of all the blades as the common width c of the blade design;

(2) The profiles and the widths of the cutter body and the wedge block are designed according to a rotation bus b and a common width c, after the profile of the blade edge part of the blade is determined, the width of the blade edge part is extended to the common width c when the width of the blade edge part is smaller than the common width c, and the extended part is sunken and avoided;

(3) Adding a shim on the back of the blade, wherein the width of the shim is consistent with the public width c, and the edge profile of the blade is biased inwards to obtain a curved profile of the shim, and the maximum rotation diameter d1 of the shim is smaller than the maximum rotation diameter d2 of the back of the blade by 1-2 mm;

(4) The design of the left pressing plate, the right pressing plate and each fastening screw is kept unchanged, and when rotors with different molded lines are processed, the blades and the cutter pads with corresponding models are installed.

Images