Хонинговальные головки

2.1 INTRODUCTION Grinding, in comparison to turning or milling, is often considered somewhat of a “black art” where wheel life and cycle times cannot be determined from standard tables and charts. Certainly precision grinding, being a finishing process with chip formation at submicron dimensions occurring by extru­sion created at cutting edges with extreme negative rake […]

3.2.1 Introduction In the case of grinding, the cutting process is the sum of singular microscopic cutting processes, whose temporal and local superposition leads to a macroscopic material removal. As a consequence, the cause-and-effect principle of grinding can only be described on the basis of the cutting behavior of the individual abrasive grains [Sawluk 1964]. […]

“Static” unbalance is the term employed for unbalance within a single plane. Balancing of static unbalance may be performed either at zero speed or at running speed. Wheels are initially balanced statically off the machine but more frequently balanced at a fixed running speed. A confusion of terms TABLE 4.3 Standard Fits for Wheel Bore […]

Forced vibrations can be eliminated in three ways. First is to eliminate the energy at its source. Wheels, motors, belts, and workpieces should all be balanced as should the three-phase power supply. Ultra-precision bearings and ball screws should be used and properly maintained in work and wheel spindles and slides. Second, the grinder should be […]

Since 1960, several other methods of growing diamond have been developed. In 1970, DuPont launched a polycrystalline material produced by the sudden heat and pressure of an explosive shock. The material was wurtzitic in nature and produced mainly at micron particle sizes suitable more for lapping and polishing than grinding or as a precursor for […]

Table 6.2 and Table 6.3 give values for typical form-holding capabilities and roughness as a function of grit size for standard precision-plated and postplated conditioned wheels. Roughness values will vary somewhat depending on workpiece hardness. The values indicated are those for grinding aerospace alloys in the hardness range 30 to 50 HrC using CBN abrasive. […]

7.1 INTRODUCTION Understanding the procedures and mechanisms of dressing grinding wheels is critical to obtaining optimum performance in grinding. The available dressing methods are numerous and confusing — even the basic terminology varies from one manual or paper to another. For the purposes of this discussion, the following terms will be used: • Truing: Creating […]

When dressing a conventional wheel, a similar break in period occurs but is generally too rapid to be observed, and the dress infeed amount is such that most or all of the layer affected by grinding is removed and a fresh surface layer is created each dress. This is not so for CBN where the […]

The statement that a process can be controlled “within an acceptable range” requires some definition. A recent study by Hitchiner and McSpadden (2005) investigated the process variability of various vitrified cubic boron nitride (CBN) processes as part of a larger program to develop improved wheel technology. They showed that under “ideal” conditions repeatability of wheel […]

3.3.1 Introduction The determination of the grinding wheel topography can be divided into static, kinematic, and dynamic methods [Bruecher 1996]: • Static methods—All abrasive grains on the surface of the grinding tool are considered. The kinematics of the grinding process is not taken into account. • Dynamic methods—In this process, the number of actual abrasive […]