Cylinder bore a boring roll forming process
I produced the Dong Fang Hong 75 Dozer blade cylinder, length 760mm, diameter 75mm. Required surface roughness of Ra = 0.2μm.. For such a deep hole, put into production over the years,Roll forming machine and are based on rough drawing, fine drawing, honing working procedure process. Rough drawing, the machine speed 28r/min, take the knife a small amount of low productivity, encountered rough is not normal, it is time-consuming and labor, but also easy to beat knife, tool wear fast, low life, honing a large margin. Surface roughness is not easy to achieve product requirements. Honing a need for more than 1h, the workers labor intensive, but also difficult to ensure product quality.

With the growing production bulldozers, tanks Hole became urgent problem. Domestic and foreign counterparts by learning advanced techniques and methods, decided to roll with a boring process to replace the original pull hinge honing process, but sometimes there rolling head and parts Jisi phenomenon. Processing methods in the analysis, based on improved processing program, made a breakthrough success of a boring roll forming, through the measured surface roughness Ra ≤ 0.1μm, cylindrical form is not greater than 0.01mm. Solve the cylinder bore machining of the key issues. Processing of a cylinder hole, the original of each required to 3h, now reduced to just 25min, and easy to operate, to reduce the labor intensity.

2, equipment and tooling used

Cylinder bore a boring roll processing equipment used in the new technology is 3mC630 lathe, motor power 10KW, this conversion of the fuel tank hole boring machine rolling machine, rigid and coaxial transmission dedicated deep hole machine tool than poor. Cooling and chip removal tool is a problem, for which designed a special fixture. Chip cooling and the oil system as shown in Figure 1. Clamp one end of the rigid connection with the spindle, a rigid connection with the spindle put on Roll forming two rectangular holes dug for iron and the cooling oil discharged from the hole, into the set of litter containers, filtration and cooling oil flow back again within the recycling tank. Clamp the other end is fixed to the machine axis guide surface, the workpiece mounted in the fixture, the use of tanks on the cylindrical chamfer (3 × 45 °) and positioning the workpiece face. Toggle back to resell to the workpiece rotation, using cylinder workpiece.

As the piece is longer, boring rolling device processing, we must move forward knife, large pallet boxes used machine tools for mobile, fixed to putting on a large pallet boxes, putting thin and long, in the processing by the cutting force and putting squeeze a lot of pressure, the fixture is equipped with a guide sleeve. With randomly oriented set of bed and workpiece spindle rotation, ensuring boring rolling device and putting coaxial with the workpiece, while the supporting role played putt. Rolling in boring into the work piece before the first hand, guided by sets of fixtures to ensure concentric tool and workpiece.

As the workpiece and fixture as a closed body, tool and workpiece exposed to the rolling device with a lot of heat, iron deformation also produced a lot of heat, these calories are concentrated in the tank can not be distributed out of the hole, cut off the iron debris can not be discharged so that the tool and the rolling device very easy to damage. To solve the problem, design a set specifically for cooling and chip removal of the oil system. Selected 5.5KW motor, pump flow 125L/min, from one end of fixture and high-pressure diesel injection mixture of molybdenum disulfide oil, through the guide sleeve into the workpiece, the cooling device and tool roll, never use high pressure oil to iron processing hole away from the other end into the fixture box set of chips. Back the knife, the large delay in the installation of a 1.1KW board motor, belt drive with a fast return big pallet knife. After such transformation on the machine, proven oil tanks can guarantee the processing precision.