Brief introduction of deep hole drilling
According to the form of chip removal, deep hole drilling can be divided into external chip removal deep hole drilling (gun drilling) and internal chip removal deep hole drilling (BTA).
Brief introduction of gun drilling
Dezhou Drillstar Cutting Tool Co., Ltd. -- deep hole machine tool, Dezhou deep hole, deep hole cutter, copper sleeve, lathe, CNC lathe, heavy machine tool, casting, copper tile, casting, copper tile gun drilling method belongs to the external chip removal processing method. The cutting oil is supplied to the rotary joint at the end of the main shaft of the machine tool by the high-pressure pump group of the cooling system, and is supplied to the cutting edge of the cutter through the inner hole of the main shaft and the inner cavity of the cutter. The cutting edge is cooled and lubricated, and then the cutting oil with chips is discharged into the guide device through the gap between the V-groove of the tool and the machined hole wall. Before the cutter enters the workpiece, it depends on the guide sleeve to guide, and after the cutter enters the workpiece, it depends on the self guiding function to complete the deep hole drilling. This method is generally suitable for deep hole machining ≤ Φ 40mm.
BTA processing introduction
Dezhou Drillstar Cutting Tool Co., Ltd. -- deep hole machine tool, Dezhou deep hole, deep hole tool, copper sleeve, lathe, CNC lathe, heavy machine tool, casting, copper tile, casting, copper tile BTA belong to the internal chip removal processing mode. Cutting oil is supplied to the guide device by the high-pressure pump group of the cooling system, through the gap between the outer part of the tool and the processed hole wall, to the cutting edge of the tool, to the cutting edge Carry out cooling lubrication and discharge the cutting oil through the inner hole of the cutter and the inner hole of the main shaft of the machine. Before the cutter enters the workpiece, it depends on the guide sleeve to guide, and after the cutter enters the workpiece, it depends on the self guiding function to complete the deep hole drilling. This method is suitable for deep hole drilling, boring and nesting, but it is mainly used for deep hole machining with diameter > Φ 12mm due to the limitation of chip removal space in drill pipe inner hole.
Main features of deep hole machining
1. Compared with twist drill, it has very high efficiency; in general, the length diameter ratio is less than 200:1, and it can be drilled by one-time feeding, without tool withdrawal in the middle, it can obtain excellent dimensional accuracy, straightness, surface roughness, and it can process straight hole, inclined hole, cross hole, blind hole, reaming, etc.; the drilling process has higher requirements for machine tools, cutters, cutting fluid and related equipment.
2. If the deep hole addition is completed in a closed state, the cutting condition of the tool cannot be observed directly. Only by experience, can we judge whether the cutting process is normal by listening to the sound, looking at the chips, observing the load of the machine tool, the change of the cutting fluid pressure, and the vibration of the machine tool.
3. Cutting heat is not easy to emit. In general, 80% of the cutting heat is taken away by cutting in the process of cutting, while only 40% of the cutting heat is taken away by deep hole drilling. The cutting tool accounts for a large proportion of the cutting heat. It is easy to diffuse late and overheat, and the cutting edge temperature can reach 600 ℃. Effective forced cooling must be adopted.
4. Chips are not easy to discharge. Because the hole is too deep, the path of chip discharge is long, and it is easy to block, causing the bit to break. Therefore, it is necessary to control the length of chips in order to force chip removal.
5. The rigidity of tool system is poor. Due to the limitation of aperture size, large length diameter ratio of hole, thin and long drill pipe, poor rigidity, easy to generate vibration, easy to deviate drilling, so the support and guidance of tool system is very important, especially gun drilling machine tool.
6. Deep hole cutting tool self guiding. In the process of deep hole machining, the tool bar is thin and long, so there are guide blocks on the tool. During machining, the guide block contacts the machined surface, which has the function of supporting and self guiding the tool, so the deep hole machining can be completed.
Cooling medium has great influence on deep hole machining. In the process of deep hole machining, the guide block of the deep hole cutter is in direct contact with the machined surface of the hole. The cooling medium not only cools the machining area and washes away the chips, but also forms an extreme pressure oil mold to protect the guide block of the cutter and improve the service life and machining accuracy of the cutter. Therefore, the cooling medium generally contains extreme pressure additives and other components.
Main application fields of deep hole machining
At present, our company's deep hole drilling machine products cover mold, automobile, boiler, coal machine, nuclear power, engineering machinery, oil pump nozzle, hydraulic pressure, military industry (gun), aerospace, medical equipment, tube plate, textile machinery, paper-making machinery, steel (roll), feed machinery, crankshaft and other industries.