CN-117754368-B - Grinding and mortise processing method for fir milling cutter

CN117754368BCN 117754368 BCN117754368 BCN 117754368BCN-117754368-B

Abstract

The invention relates to a grinding method of a fir-type milling cutter, which comprises the steps of checking sharpness and diameter abrasion loss of the fir-type milling cutter, determining a grinding mode, grinding front corners of the fir-type milling cutter by using a grinding wheel, or grinding rear corners and front corners of the fir-type milling cutter by using a grinding wheel, and grinding rear corners and front corners of the fir-type milling cutter by using the grinding wheel. The invention also relates to a fir-tree type mortise processing method using the fir-tree type milling cutter, which comprises the steps of checking the milling cutter, determining a processing mode, and performing one-cutter forming processing or two-cutter forming processing. According to the polishing method, the regrinding times of the fir type milling cutter are increased, the service life of the fir type milling cutter is prolonged by 3-4 times, and the cost of the fir type milling cutter is reduced by 20%. The processing method of the invention ensures the processing precision of the fir-tree type mortises.

Inventors

WANG XIAOHONG
Qin chaoyang
WANG ZHENGBING
Yang Duoduo
ZHENG JUNJUN
WANG YANING
HUO HAIYAN
LIU YAJUAN
LI HENGBO
QI WENPING
WANG PANPAN
ZUO PINGYING

Assignees

西安陕鼓动力股份有限公司

Dates

Publication Date: 20260505
Application Date: 20240105

Claims (4)

1. The fir-type mortise processing method is characterized by comprising the following steps of: step 1, checking a milling cutter, and determining a coping mode: for the fir type milling cutter, checking the sharpness of the cutting edge of the milling cutter, and continuously using the milling cutter when the sharpness of the cutting edge meets the use requirement; When the milling is needed, checking the diameter abrasion loss of the fir-tree milling cutter at the tooth shape part, and determining the milling mode of the milling cutter according to the diameter abrasion loss, wherein the specific criteria are as follows: When the diameter abrasion loss is less than or equal to 0.2mm, the cutting edge is polished by adopting a rake angle polishing mode; when the diameter abrasion loss is more than 0.2mm, the cutting edge is polished by adopting a back angle and front angle polishing mode; Step 2, front angle grinding: grinding the front angle of the fir-type milling cutter by adopting a grinding wheel, wherein the grinding surface of the grinding wheel is parallel to the front cutter surfaces, grinding each front cutter surface one by one, and grinding the front cutter surfaces until the grinding amount is less than or equal to 0.2mm and the front angle cutting edge is qualified, and continuing to use the milling cutter; Step 3, grinding the rear angle and the front angle: Grinding the rear angle of the fir milling cutter by adopting a grinding wheel, wherein the grinding surface of the grinding wheel corresponds to the angle of the ground rear angle until the cutting edges of the two rear angles are qualified; Grinding the front angle of the fir-type milling cutter by adopting a grinding wheel until the front angle cutting edge is qualified; Finishing the grinding of the rear angle and the front angle, and continuously using the milling cutter; step 4, checking the milling cutter and determining the processing mode: The fir type mortises are processed by adopting a fir type milling cutter, the diameter abrasion loss of the milling cutter at the tooth form part is checked, and the mortises processing mode is determined according to the diameter abrasion loss, wherein the concrete criteria are as follows: when the diameter abrasion loss is smaller than 0.2mm, adopting a one-knife forming processing mode; when the diameter abrasion loss is more than or equal to 0.2mm, adopting a two-cutter forming processing mode; Step 5, one-knife forming processing: The center of the fir type milling cutter is overlapped with the center of the fir type mortises, and the fir type milling cutter is formed by one-step feeding; step 6, two-knife forming processing: the center of the fir type milling cutter is not coincident with the center of the fir type mortises, the center line of the fir type milling cutter is offset delta/2 relative to the center line of the fir type mortises, and delta is the grinding amount of the diameter of the cutter; The milling cutter is offset to the center of the mortise, and the milling cutter is fed back and forth, and the two times of feeding are respectively offset to the left once and the right once.
2. The method for processing the fir-tree type mortise according to claim 1, characterized in that the step 2, the rake angle grinding, further comprises repeating grinding and use for 5 times when the sharpness of the cutting edge does not meet the use requirement.
3. The method of claim 1, wherein the grinding wheel grinds the fir tree type milling cutter, including rough grinding and finish grinding.
4. The method for processing the fir tree-type mortise according to claim 1, characterized in that in the step 5, in the two-blade forming process, the abrasion loss of the diameter of the blade is greater than 0.2mm, the grinding loss of the diameter of the blade is δ=1 mm, and the whole tooth form of the blade is translated toward the center of the blade by 0.5mm.

Description

Grinding and mortise processing method for fir milling cutter Technical Field The invention belongs to the technical field of turbine machining, and particularly relates to a method for grinding a fir milling cutter and machining a tongue and groove. Background The main shaft is a key part of the turbine expander, the moving blades are arranged on the main shaft through the blade root mortises of the main shaft, the functions of the moving blades can be realized, the processing quality of the blade root mortises of the main shaft is directly related to the dynamic balance of the rotor, and the performance and the service life of the whole unit are also related. The main shaft of the turbine expander is made of alloy steel, the blade root mortises of the main shaft are positioned on the outer circle of the hub, the mortises are fir type mortises which are uniformly distributed along the axial direction and the circumference of the main shaft, the processing of the blade root mortises of the main shaft is generally multistage, and the processing of the blade root mortises of the main shaft is finished on a planer type milling machine or special equipment. The processing of blade root tongue-and-groove not only needs to guarantee that tooth type dimensional accuracy satisfies the design drawing requirement, and tooth type surface roughness also requires very high, is Ra1.6, adopts fir type shaping milling cutter to process this kind of processing of fir type tongue-and-groove, and the tooth form accuracy of main shaft tongue-and-groove relies on shaping finish milling cutter's precision to guarantee. The regrinding method of the formed finish milling cutter not only ensures the dimensional accuracy and the surface roughness of the design drawing, but also improves the regrinding times of the formed finish milling cutter, reduces the cutter cost and has strong economical efficiency. Therefore, the combined regrinding process method of the fir type finish milling cutter is of great importance. Disclosure of Invention The invention provides a grinding and mortice processing method for a fir-tree type milling cutter, which aims to solve the problems of low regrinding frequency of the fir-tree type milling cutter and high processing cost of a blade root mortice of a main shaft of a turbine expander. The technical scheme adopted for solving the technical problems is as follows: a grinding method of a fir milling cutter comprises the following steps: Step 1, checking a milling cutter and determining a coping mode For the fir type milling cutter, the sharpness of the cutting edge of the milling cutter is checked, when the sharpness of the cutting edge meets the use requirement, the milling cutter is used continuously, and when the sharpness of the cutting edge does not meet the use requirement, the milling cutter needs to be polished. When the milling is needed, checking the diameter abrasion loss of the fir-tree milling cutter at the tooth shape part, and determining the milling mode of the milling cutter according to the diameter abrasion loss, wherein the specific criteria are as follows: when the diameter abrasion loss is less than or equal to 0.2mm, the cutting edge is polished by adopting a rake angle polishing mode. When the diameter abrasion loss is more than 0.2mm, the cutting edge is polished by adopting a back angle and front angle polishing mode. Step 2, front angle coping The front angle of the fir-type milling cutter is polished by adopting a grinding wheel, the grinding surface of the grinding wheel is parallel to the front cutter surfaces, each front cutter surface is polished one by one, the polishing amount is less than or equal to 0.2mm, and the milling cutter is continued to be used until the front angle cutting edge is qualified. Step 3, grinding the rear angle and the front angle Grinding the rear angle of the fir milling cutter by adopting a grinding wheel, wherein the grinding surface of the grinding wheel corresponds to the angle of the ground rear angle until the cutting edges of the two rear angles are qualified. Grinding the front angle of the fir-type milling cutter by adopting a grinding wheel until the front angle cutting edge is qualified. And finishing the grinding of the rear angle and the front angle, and continuously using the milling cutter. According to the method for grinding the fir-tree milling cutter, in the step 2, the front corner is grinded, and further the steps of repeatedly grinding and using can be repeated for 5 times when the sharpness of the cutting edge does not meet the use requirement. According to the grinding method for the fir-tree type milling cutter, the grinding wheel grinds the fir-tree type milling cutter, and the grinding method comprises rough grinding and fine grinding. A fir-type tongue-and-groove processing method uses a fir-type milling cutter, comprising the following steps: step 4, checking the milling cutter and determining the processing mode The