Military Defense
Teflon Polytetrafluoroethylene (PTFE) can be machined through compression or extrusion molding，it also can be made into an aqueous dispersion for coating, impregnation, or fiber. PTFE is widely used as a high and low temperature resistant, corrosion resistant material, insulating material, anti-sticking coating, etc. in the industries of atomic energy, aerospace, electronic, electrical, chemical, machinery, instrument, construction, textile, food, etc.
Polytetrafluoroethylene also called Teflon\PTFE\PTFE board\F4, etc. Generally known as “non-stick coating” or “easy clean wok material” 。Teflon is a synthetic polymer material that uses fluorine to replace all hydrogen atoms in polyethylene. This material Resistant to acid, alkali, and various organic solvents，which is almost insoluble in all solvents. At the same time, PTFE is resistant to high temperatures and because of its low coefficient of friction, it can be used for lubrication, besides it is also an ideal coating for easy cleaning wok and water pipe inner layer.
Example . Internal gear sleeve
skills requirement
1.Material: 40Cr steel. 2.Heat treatment: quenching and tempering 235HBW.
1.Part drawing analysis
1) The material of the parts is 40Cr steel.
2) Based on the center line of the inner hole of ϕ180H7, the coaxiality tolerance of ϕ165H7 inner hole, ϕ220h8 outer circle and ϕ200h9 outer circle to ϕ180H7 inner hole is ϕ0.02mm.
2.Process analysis
1) The tooth part of the inner gear sleeve is in the middle part, which is difficult to process.
2) The ϕ180H7 inner hole and the ϕ165H7 inner hole require high dimensional accuracy and high surface quality. When grinding, choose a suitable grinding wheel and a reasonable cutting amount.
Machining process of inner gear sleeve (unit: mm)
| Part Name | Blank species | Material | Production type |
|---|---|---|---|
| Inner gear sleeve | Forging | 40Cr steel | Small batch |
| Process | Work step | Process content | Equipment | Tools, measuring tools, auxiliary tools |
|---|---|---|---|---|
| 10 | Forging: The forging is a hollow cylinder with an inner diameter of ϕ100 | |||
| 20 | Rough turning | Horizontal lathe | ||
| 1 | Use a self-centering chuck to clamp one end of the outer circle of the blank, align, clamp, and turn the end face to be flat | 45° elbow turning tool | ||
| 2 | Boring each inner hole to ϕ145 | Boring tool | ||
| 3 | Turn each outer circle to ϕ225 | 90° external turning tool | ||
| 30 | Heat treatment: tempering 235HBW | Box furnace | ||
| 40 | Fine turning | CNC lathe | ||
| 1 | Use a self-centering chuck to clamp the outer circle that has been turned, aligning, clamping, and turning the end face to make it smooth | 35° turning tool | ||
| 2 | Turning ϕ220h8 outer circle, leaving grinding allowance 0. 30 | 35° turning tool | ||
| 3 | Turning ϕ180H7 inner hole, leaving grinding allowance 0.40 | 35° turning tool | ||
| 4 | Turning 10 × ϕ182 grooves, surface roughness Ra3. 2μm | Grooving knife | ||
| 5 | Turning ϕ150. 36H12 inner hole, surface roughness Ra3. 2μm | 35° turning tool | ||
| 6 | Turning inside and outside circles, chamfering is completed | 35° turning tool | ||
| 7 | Drilling and tapping 2 × M12, threaded holes are completed | Thread tap M12 | ||
| 8 | Turn around. Use a self-centering chuck clamp ϕ220h8 outer circle, aligning, clamping, turning left end surface leaving a grinding amount 0. 10 | 35° turning tool | ||
| 9 | Turning ϕ200h9 outer circle, leaving grinding allowance 0. 30 | 35° turning tool | ||
| 10 | Turning ϕ168 inner hole, surface roughness Ra3. 2μm | 35° turning tool | ||
| 11 | Turning ϕ165H7 inner hole, leaving grinding allowance 0.40 | 35° turning tool | ||
| 12 | Turning inside and outside circles, chamfering is completed | 35° turning tool | ||
| 50 | The left end surface is flat ground, surface roughness Ra3. 2μm | Surface Grinder | ||
| 60 | Grind the outer circle | Cylindrical grinder | ||
| 1 | The nut and compression mandrel is aligned according to the outer circle of ϕ220h8, and the outer circle of ϕ220h8 is ground, and the surface roughness is Ra0. 8μm | |||
| 2 | Grinding ϕ200h9 outer circle, surface roughness Ra1. 6μm | |||
| 3 | Grinding size 35, left surface finished | |||
| 70 | Grind the inner hole | Internal grinder | ||
| 1 | Use the self-centering chuck to clamp the outer circle of ϕ220h8, and align the left end ϕ220h8 outer circle and size 35 on the left to 0.01, and grind the inner hole of ϕ165H7, surface roughness Ra0. 8μm | |||
| 2 | Turn around. Use the self-centering chuck to clamp the outer circle of ϕ200h9, align the outer circle of ϕ200h9 0.01, grind the inner hole of ϕ180H7, and surface roughness Ra0. 8μm | |||
| 80 | Gear shaping: align according to the outer circle of ϕ200h9, press the right end face with a pressure plate,gear shaping completed | Gear shaper | M5 gear shaper | |
| 90 | Inspection: ϕ180H7 inner hole, ϕ165H7 inner hole size and coaxiality of the two holes | Inspection station | ||
| 100 | Oiling, packaging, warehousing | Warehouse |