CN103692177A - Method for machining extension drill - Google Patents

Abstract

The invention discloses a method for machining an extension drill, belongs to the field of machining, and aims to solve the problem that the drill coaxiality cannot be met in the conventional process scheme. The method comprises the following steps: welding a straight shank twist bit together with a tool bar by adopting a welding sleeve, and turning the welding sleeve for welding an auxiliary component; grinding the blade excircle and taper shank of the extension drill; grinding a 118-degree taper lead angle and a back angle on a cutter grinding machine. According to the method, the standard straight shank twist bit is welded together with the tool bar, so that the milling stress and deformation of a drill groove are reduced; cutting parameters are optimized, so that the machining efficiency is increased to the maximum extent on the premise of ensuring the machining accuracy; a welding process scheme and the welding parameters are optimized, so that the extension drill has sufficient drill strength and qualified coaxiality and meets the use requirements.

Description

A kind of spreading drill bit processing method

Technical field

The present invention relates to a kind of spreading drill bit processing method, belong to field of machining.

Background technology

Spreading drill bit is the dedicated tool (as the axially extending bore of the axially extending bore of processing casing roller expansion shell, processing branch sleeve) of deep hole processing, for bit diameter, be less than or equal to the spreading drill bit of Φ 12mm, during processing and manufacturing, adopt welding pattern, head adopts the transformation of the way of standard parallel shank twist drill, and it is crooked that existing processing method easily makes spreading drill bit produce.

Summary of the invention

The object of the invention is cannot meet in order to solve existing process program the process requirements of spreading drill bit, for guaranteeing the processing and manufacturing precision of spreading drill bit, and then provide a kind of spreading drill bit processing method.

The particular content of spreading drill bit processing method is:

Step 1: this spreading drill bit is welded by standard parallel shank twist drill and knife bar, 60 ° of counter centers of grinding standard parallel shank twist drill, for postorder provides accurate positioning datum;

Step 2: turning weldering cover; Weldering cover is accessory when welded by standard parallel shank twist drill and knife bar; The staight shank cylindrical 0.2mm matched in clearance of weldering cover endoporus and standard parallel shank twist drill;

Step 3: turning knife bar; Left end knife bar cylindrical and weldering cover endoporus 0.2mm matched in clearance; Knife bar taper shank cylindrical stays grinding allowance 0.6-0.7mm, knife bar right-hand member drill centers; During turning, adopt 85 °～90 ° lathe tools to carry out machining; Cutting parameter is: rotating speed 900r/min, amount of feeding 0.15mm/r, cutting depth 0.5mm;

Step 4: at horizontal milling machine Milling Process weldering cover waist hole and knife bar tang;

Step 5: knife bar is heat-treated, knife bar is hardened to HRC35-45, and in alignment 0.2mm;

Step 6: 20 ° of inclined-planes of cutting on line lathe cutting processing standard 20 ° of inclined-planes of parallel shank twist drill shank and knife bar left end;

Step 7: 20 ° of inclined-planes of repair standard parallel shank twist drill and 20 ° of inclined-planes of knife bar, guarantee to fit tightly;

Step 8: standard parallel shank twist drill and knife bar is welded on coreless induction furnace equipment; During welding, solder flux is put into 20 ° of solder bond face places, 720～750 ℃ of welding temperatures, melt be full of after solder bond face completely until scolder, put back to stove tempering destressing, and 400 ℃ of temperatures are incubated 2 hours, and then air cooling is to normal temperature;

Step 9: car falls to weld accessory weldering cover;

Step 10: grinding spreading drill bit blade cylindrical and taper shank, guarantee in coaxial precision 0.02mm;

Step 11: in 118 ° of taper lead angles of cutter sharpener grinding and relief angle thereof;

Step 12: carve figure number, cutter is packed; Spreading drill bit completion of processing.

Described solder flux is the mixture of 105 copper sheets and sodium tetraborate.

Spreading drill bit is slender axles parts, and when processing and manufacturing, axiality is to be difficult to most guarantee, for guaranteeing the machining accuracy of this spreading drill bit, has optimized process program, adopts welding pattern.Owing to adopting standard straight shank drill and knife bar welding pattern, stress and the distortion of cut drill groove have been reduced; Preferably optimum cutting parameter, guaranteeing, under the prerequisite of machining accuracy, to improve to greatest extent working (machining) efficiency; Optimize welding procedure scheme and welding parameter, made this spreading drill bit there is enough cutter intensity and qualified axiality, met instructions for use.

Accompanying drawing explanation

Fig. 1 spreading drill bit outline drawing;

Fig. 2 spreading drill bit Welding Structure figure;

Fig. 3 welds cover outline drawing.

The specific embodiment

The specific embodiment of the present invention is: step 1: 60 ° of counter centers of grinding standard parallel shank twist drill; This spreading drill bit is welded by standard parallel shank twist drill and knife bar, for guaranteeing the machining accuracy of postorder, needs 60 ° of counter centers of grinding, thinks that postorder provides accurate positioning datum;

Step 2: turning weldering cover; Weldering cover is accessory when welded by standard parallel shank twist drill and knife bar, runs off when preventing solder flux heating and melting; The staight shank cylindrical 0.2mm matched in clearance of weldering cover endoporus and parallel shank twist drill, in order to guarantee welding precision requirement;

Step 3: turning knife bar; Left end knife bar cylindrical and weldering cover endoporus 0.2mm matched in clearance, in order to guarantee welding precision requirement; Knife bar taper shank cylindrical stays grinding allowance 0.6-0.7mm, knife bar right-hand member drill centers; For reducing radial cutting drag, reducing axial bending distortion, during turning, adopt 85 °～90 ° lathe tools to carry out machining; Cutting parameter is: rotating speed 900r/min, amount of feeding 0.15mm/r, cutting depth 0.5mm;

Step 4: at horizontal milling machine Milling Process weldering cover waist hole and knife bar tang;

Step 5: knife bar is heat-treated, knife bar is hardened to HRC35-45, and in alignment 0.2mm;

Step 6: 20 ° of inclined-planes of cutting on line lathe cutting processing standard parallel shank twist drill shank and knife bar left end;

Step 7: 20 ° of inclined-planes of repair standard parallel shank twist drill and knife bar, guarantee to fit tightly;

Step 8: standard parallel shank twist drill and knife bar is welded on coreless induction furnace equipment; During welding, solder flux (mixture of 105 copper sheets and sodium tetraborate) is put into 20 ° of solder bond face places, 720～750 ℃ of welding temperatures, until scolder, melt be full of after solder bond face completely, put back to stove tempering destressing, 400 ℃ of temperatures, are incubated 2 hours, then air cooling, to normal temperature, completes welding sequence;

Step 9: car falls to weld accessory weldering cover;

Step 10: grinding spreading drill bit blade cylindrical and taper shank, guarantee in coaxial precision 0.02mm.

Step 11: in 118 ° of taper lead angles of cutter sharpener grinding and relief angle thereof;

Step 12: carve figure number, cutter is packed; Spreading drill bit completion of processing.

Claims (2)

1. a spreading drill bit processing method, is characterized in that the step of described processing method is:

Step 1: this spreading drill bit is welded by standard parallel shank twist drill and knife bar, 60 ° of counter centers of grinding standard parallel shank twist drill, for postorder provides accurate positioning datum;

Step 2: turning weldering cover; Weldering cover is accessory when welded by standard parallel shank twist drill and knife bar; The staight shank cylindrical 0.2mm matched in clearance of weldering cover endoporus and standard parallel shank twist drill;

Step 3: turning knife bar; Left end knife bar cylindrical and weldering cover endoporus 0.2mm matched in clearance; Knife bar taper shank cylindrical stays grinding allowance 0.6-0.7mm, knife bar right-hand member drill centers; During turning, adopt 85 °～90 ° lathe tools to carry out machining; Cutting parameter is: rotating speed 900r/min, amount of feeding 0.15mm/r, cutting depth 0.5mm;

Step 4: at horizontal milling machine Milling Process weldering cover waist hole and knife bar tang;

Step 5: knife bar is heat-treated, knife bar is hardened to HRC35-45, and in alignment 0.2mm;

Step 6: 20 ° of inclined-planes of cutting on line lathe cutting processing standard 20 ° of inclined-planes of parallel shank twist drill shank and knife bar left end;

Step 7: 20 ° of inclined-planes of repair standard parallel shank twist drill and 20 ° of inclined-planes of knife bar, guarantee to fit tightly;

Step 8: standard parallel shank twist drill and knife bar is welded on coreless induction furnace equipment; During welding, solder flux is put into 20 ° of solder bond face places, 720～750 ℃ of welding temperatures, melt be full of after solder bond face completely until scolder, put back to stove tempering destressing, and 400 ℃ of temperatures are incubated 2 hours, and then air cooling is to normal temperature;

Step 9: car falls to weld accessory weldering cover;

Step 10: grinding spreading drill bit blade cylindrical and taper shank, guarantee in coaxial precision 0.02mm;

Step 11: in 118 ° of taper lead angles of cutter sharpener grinding and relief angle thereof;

Step 12: spreading drill bit completion of processing.

2. a kind of spreading drill bit processing method according to claim 1, is characterized in that: described solder flux is the mixture of 105 copper sheets and sodium tetraborate.