New skills for machining high-precision bearing holes

Source: Bearing network time: 2013-01-11

/*250*250 was created on 2017/12/25*/ var cpro_id = 'u3171089';

The problem with many indexable insert bits is that they overlap the cutting edges of the two inserts to produce the correct cutting diameter; so even if the drill has two flutes; the function of the insert is to form a single-edged but asymmetrical cut. Blade. This depiction is inherently unbalanced. Thus, indexable drill bits must slow the feed rate and reduce the feed rate as they enter the cutting; forcing users to trade off between economy and productivity.
Another difficulty in the unbalanced cutting process is the accuracy of the bearing bore. Typically; the intermediate insert of the indexable drill bit is cut first; this can cause large radial cutting forces; simply causing the drill rod to deflect. Once the drill bit violates the middle It can't machine high precision holes.
Because of these reasons; indexable drills are generally limited to the roughing of the hole. When the public service of the hole needs to be less than 0. 012 ~ 0. 016 inches; it is necessary to add a processing process after the indexable drill bit.
Several tool manufacturers have now looked again at indexable insert bits; seeking to overcome the inherently unbalanced cutting forces in their depictions. One of the developments in these product lines is Sandvik Coromant (Fair). Lawn, New Jersey) introduced CoroDrill 880. According to Professor Bruce Carter Sandvik product analysis; this indexable drill depicts avoid the problems generated by unbalanced cutting force; thereby improving the quality and productivity of the hole; adhere together The blade has the economics of four available cutting edges. The key to this is the concept that the company calls "step-by-step skills." This phrase depicts the cutting edge on the blade "gradually" entering the workpiece; I heard that it can be greatly reduced and æ›©The radial cutting force associated with the conventional indexable drill bit. This concept touches two different viewpoint blades and different cutting characteristics. The intermediate blade has a significant irregular cutting edge shape; the outer edge blade Contacted a light trimming blade type.
In the first step of entering the workpiece; the outer corner of the intermediate blade touches the workpiece. This causes the drill bit to start with a relatively low radial force; the deflection of the drill pipe is minimized. In the second step; the outer corner of the outer edge blade touches Workpiece. This balances the force generated by the intermediate blade. In the third step, the final step; the middle blade is left with some cutting ends.
Mr. Carter said; by dividing the cutting process into three relatively small steps; the cutting force is reduced to less than half of the cutting force produced by those typical blade drills; and the balance of the cutting forces causes the drill pipe at the entrance to be biased. The skew is virtually eliminated. The combination of balanced drilling process, low radial cutting force and minimized skew has the following advantages:
â—† higher precision holes.
â—† The feed rate is improved to 100%; it depends on the workpiece data.
â—† more determined when drilling deep hole diameter of four or more times.
â—† eliminates the possibility of subsequent machining required hole; depends on the accuracy required.
Another advantage mentioned is that the depiction gives the outer edge insert four fully available cutting edges. If the feed is higher than 0.005ipr; some indexable drills with square inserts will lose the fourth cutting edge. However, there is a step-by-step skill; the shape of the intermediate blade that is different from the others can still guarantee the fourth cutting edge when the feed rate is up to 0.013ipr.
In the end, Mr. Carter pointed out that the wiper blade technique used on the outer edge of the blade produces excellent surface roughness; this new depiction is even higher with the feed rate. In the experiment; the feed is zero. At 004ipr, the surface roughness can reach 20 microinches (equal to one millionth of an inch), and the surface roughness can reach 80 to 120 microinches when the feed rate is as high.

Recommend to friends comments close window

Bearing related knowledge

Skill analysis: characteristics and use of spindle bearing oil
SKF bearing production process
Work after NSK bearing equipment view work analysis of the bearing process of the bearing ring processing speed (2)

This article links to http://
Please indicate China Bearing Network http://

Previous:Analysis of the appearance of rolling bearings View next: How to identify the agricultural machinery bearing code rules

Ungrouped

kaiping aida sanitary ware technology co.,ltd , https://www.kpaidafaucets-jm.com