The precision of boring is very high, the dimensional precision of fine boring can reach IT8~IT7, and the aperture can be controlled within 0.01mm precision.If it is fine boring, the machining precision can reach TT7-IT6, and the surface quality is good.For general boring, the surface roughness Ra is 1.6~0.8 m.Let’s see how the boring should be done.
Boring steps and precautions
Boring cutter installation
It is very important to install the boring tool working part, especially for the work adjustment using eccentric principle. After installing the boring tool, it must pay attention to observe the main blade plane of the boring tool, whether it is on the same level with the feed direction of the boring tool head?Install on the same level to ensure that several cutting edges are at normal machining angles.
Boring tool try boring
The boring tool shall adjust the allowance of 0.3-0.5mm according to the requirements of the manufacturing process, and the reaming and matching boring hole shall adjust the allowance of rough boring ≤0.5mm according to the allowance of the initial hole. The allowance of subsequent fine boring shall be guaranteed.
After the boring tool is installed and lent, it is necessary to test and verify whether the debugging of the boring tool meets the requirements of rough boring.
Boring requirements
Before boring and machining, carefully check whether the tooling, the positioning reference of the workpiece and each positioning element are stable and reliable.
What is the diameter of the initial hole to be machined with calipers?Calculate how much machining allowance is left?
Check whether the repeated positioning accuracy and dynamic balance accuracy of the equipment (spindle) meet the requirements of machining before boring.
The dynamic runout value of the gravity suspension of the boring bar must be checked in the process of horizontal adding the boring hole to reduce the influence of centrifugal shear vibration by modifying the cutting parameters reasonably.
According to the rough boring, semi-fine boring, fine boring steps to reasonably distribute the layer boring allowance, the rough boring allowance of about 0.5mm is appropriate;Fine boring, fine boring margin of about 0.15mm, to avoid the semi-fine boring margin caused by too much margin let the cutter affect the precision of fine boring margin adjustment.
Difficult to process materials, high precision boring (tolerance ≤0.02mm) can increase the fine boring processing steps, the boring margin is not less than 0.05mm to avoid the machining surface elastic cutter.
In the process of boring tool on the tool, must pay attention to avoid the boring tool working part (blade and knife block) and impact on the knife block, damage to the blade and knife block guide groove so that the boring tool adjustment value changes affect the aperture machining accuracy.
In the process of boring, pay attention to keep sufficient cooling, increase the lubrication effect of machining parts to reduce cutting force.
Chip removal is strictly carried out in each processing step to prevent chip participation in secondary cutting to affect the machining accuracy of aperture and surface quality.
During the boring process, check the abrasion degree of the cutter (blade) at any time, and replace it timely to ensure the machining quality of aperture;Fine boring step is prohibited to replace the blade to prevent errors;After each step of machining, strictly implement the process quality control requirements, carefully test the actual machining aperture and make a good record, so as to facilitate analysis, adjustment and improvement of boring machining.
Post time: Jan-21-2021