Abrasive belt grinding is an efficient and high-precision machining method for special-shaped curved parts. Special-shaped curved parts are generally difficult to grind, and the softness of abrasive belt can just adapt to the characteristics of this kind of parts. The contact wheel, pressure grinding plate (block) and contact lining belt of abrasive belt grinding can be replaced at will according to the curved surface shape of the parts, and can be well matched with the curved surface in the grinding process to obtain better molding effect. Abrasive belt grinding has low processing temperature and low roughness value, which can make the machined parts obtain good surface quality and overcome grinding burn.

Grinding belongs to finish machining in machining (machining is divided into rough machining, finish machining, heat treatment and other machining methods), with less machining volume and high precision. It is widely used in machinery manufacturing. When grinding carbon tool steel and carburized and hardened steel parts, a large number of regularly arranged cracks-grinding cracks often appear on the surface basically perpendicular to the grinding direction, which not only affects the appearance of parts, but also directly affects the quality of parts. Grinding refers to the processing method of removing excess materials from the workpiece with abrasives and abrasives. Grinding is one of the widely used cutting methods.

principle

Machining the surface of workpiece with grinding tools such as high-speed rotating grinding wheel. Grinding is used to process internal and external cylindrical surfaces, conical surfaces and planes of various workpieces, as well as special and complicated molding surfaces such as threads, gears and splines. Grinding Because of the high hardness of abrasive particles and the self-sharpening of abrasive tools, grinding can be used to process various materials, including hardened steel, high-strength alloy steel, cemented carbide, glass, ceramics and marble and other high-hardness metal and non-metal materials. Grinding speed refers to the linear speed of grinding wheel, which is generally 30~35 m/s, and when it exceeds 45 m/s, it is called high-speed grinding. Grinding is usually used for semi-finishing and finishing, and the accuracy can reach IT8~5 or even higher. General surface roughness is Ra 1.25~0. 16 micron, precision grinding is Ra0. 16~0.04 micron, ultra-precision grinding is Ra0.04~0.0 1 micron, and mirror grinding can reach Ra0. The specific power of grinding (or specific energy consumption, that is, the energy consumed by removing materials per unit volume of workpiece) is greater than that of general cutting, and the metal removal rate is less than that of general cutting. Therefore, before grinding, most of the machining allowance is usually removed by other cutting methods, leaving only the grinding allowance below 0.1~1mm. With the development of high-efficiency grinding technology such as slow feed grinding and high-speed grinding, parts can be directly ground from blanks. Grinding is also used for rough machining, such as grinding off the riser of castings, flash of forgings, ingot skins, etc.

Machining characteristics

Compared with other cutting methods such as turning, milling and planing, grinding has the following characteristics:

(1) The grinding speed is very high, reaching 30m ~ 50m per second, and the grinding temperature is high, reaching1000℃ ~1500℃; The duration of the grinding process is very short, only about one tenth of a second.

(2) The grinding accuracy is high and the surface roughness is small.

(3) Grinding can not only process soft materials, such as unhardened steel and cast iron, but also process hardened steel and hard materials that other tools cannot process, such as ceramics and cemented carbide.

(4) When grinding, the cutting depth is very small, and the metal layer that can be removed in one stroke is very thin.

(5) During grinding, a large number of tiny abrasive chips fly out from the grinding wheel, while a large number of metal chips splash out from the workpiece. Wear debris and metal debris will harm the operator's eyes, and not inhaling dust from the lungs will also be harmful to the body.

(6) The grinding wheel may break during grinding due to poor quality, improper storage, improper selection of specifications and models, eccentric installation or excessive feed speed, which may cause serious injuries to workers.

(7) When manual operations are carried out near the rotating grinding wheel, such as grinding tools, cleaning workpieces or incorrect grinding wheel calibration methods, workers' hands may come into contact with the grinding wheel or other moving parts of the grinding machine and be injured.

(8) The noise generated during grinding can reach above 1 10dB, which will affect health if noise reduction measures are not taken.