Preparation of the grinding wheel before use

1, grinding machine to have someone responsible for, regular checks to ensure the normal operation.

2, the replacement of the new wheel, the total power should be cut off, while the installation should be checked before the wheel piece of crack, if the naked eye is not easy to identify, can be a solid line to lift the wheel, and then a wood gently tap, sound. Metal sound is excellent, mute bad)

3, grinding wheel machine must have a solid appropriate wheel cover, bracket from the wheel shall not exceed 5mm or not use.

4, the installation of grinding wheel, the nut shall not be too loose, too tight, should be checked before using the nut loose.

5, after the wheel is installed, be sure to idle test 23 minutes to see whether the balance of its operation, the protection device is properly reliable, test operation should be arranged for two staff, one of them standing on the wheel side.Operating wheel, By another person in the power distribution cabinet immediately cut off the power supply. To prevent accidents.

6, where the user to wear protective goggles, not on the wheel, but should stand on the side. When using the grinder, do not wear gloves, prohibited the use of cotton and other materials wrapped around the tool for grinding.

7, the wheel should be checked before use is in good condition (should not have cracks, cracks or disability) wheel shaft is installed firmly and reliably. Grinding machine and shield between the debris, whether in line with safety requirements, to confirm no problem, then start the wheel.

Keep cool

Appropriate use of cooling fluid, can speed up the dressing speed and improve the efficiency of finishing. Experience dictates that a 3/8 inch diameter coolant can remove a significant amount of heat from the dresser and extend the life of the dresser. When the diamond dressing tool passes through the grinding wheel, install a coolant nozzle that fills the entire surface of the grinding wheel or continuously refills the coolant to the diamond dressing tool. Never allow the dressing tool to exit the coolant after the dresser has been brought into contact with the grinding wheel. Otherwise it will make the diamond dressing tool, in the cold, hot extreme temperature changes, cracks or rupture.

The use of filters for high-precision cooling of the filter, to avoid dirt or chips in the cooling fluid in the cycle. Contaminated coolant can quickly wear the wheel, increasing the number of wheel dressing. Dry grinding of the grinding wheel is only possible during dry grinding (only in this case the cooling of the diamond dressing tool can be interrupted). Turn off the coolant and allow the wheel to spin for a few minutes before going to work every day. This prevents the wheel from cracking.

Precautions for using of grinding wheel

Working Principle
1, start the wheel must be 4060 seconds after the stability of speed grinding, grinding tools should stand on the side of the wheel, not on the wheel to prevent grinding wheel broken broken flying out of wounding. Product Description
2, the same piece of grinding wheel, the prohibition of two people at the same time, not allowed in the grinding wheel side grinding, grinding, the operator should stand on the side of the wheel, do not stand in front of the wheel to prevent grinding wheel crack, Occurrence of accidents, while not allowed to wear gloves operation, prohibited around the reactor operation and in the grinding laugh and slapstick.

3, grinding the standing position should be in an angle with the wheel, and the contact pressure should be uniform, non-impact grinding wheel, so as not to fragment, the grinding wheel is limited to grinding tools, not grinding heavy materials or thin iron plate and soft materials Aluminum, copper, etc.) and wood products.
4, grinding edge, the operator should stand on the side of the wheel or inclined side position, do not stand on the front wheel, while the tool should be slightly higher than the wheel center position. Not too much force to prevent slippage injury hand.
5, the wheel is not allowed to touch the water, we should always keep dry to prevent water loss after the balance, an accident.
6, does not allow grinding wheel in the larger long objects, to prevent the shattered grinding wheel flying wounding.
7, not a single hand holding the workpiece for grinding, to prevent falling off in the protective cover card broken wheel.

Some skills of dressing wheel

 The sharpening process is a sharpening process that grinds the abrasive grains of a superhard abrasive wheel. In this process, the need to remove the abrasive between the binder and abrasive wheel abrasive, grinding with a strong performance of the abrasive wheel prominent bonding agent, the formation of sharp cutting edge. Sharp must also remove small material from the pores of the grinding wheel surface to prevent the grinding force from acting on the grinding wheel from increasing and the grinding force on the grinding wheel to increase, which will cause vibration and surface burn.

Without proper sharpening, even the best wheels can not achieve the high quality and dimensional uniformity of machined parts. In fact, when you invest in high-quality grinding wheel, in order to obtain high grinding performance, it is very good dressing it is very important.

Shaping can be said to be part of the wheel preparation work, it is with the ordinary grinding wheel repair at the same time. For the superhard abrasive wheel, two processes are carried out separately, the first wheel to shape. In the use of superabrasive grinding wheel grinding, shaping is the use of plastic tools or rollers, repair sharp often use a ceramic binder dressing rod, in the shaping is completed, the grinding wheel for sharpening treatment.

It is important to ensure that the spindle bearings are at a certain temperature (such as a normal grinding wheel condition) before the grinding wheel can be trimmed and trimmed. This avoids damage to the part geometry and non-normal wear of the grinding wheel and dressing tool. Care must be taken with dressing tools because they are generally made of hard, abrasion-resistant but brittle diamond material and are very sensitive to minor cracks and crushing due to minor impact, stress.

Because the diamond shaper itself is a tool, need to remain very sharp. The use of a dull finishing tool to dress the wheel surface will make the wheel blunt. In order to maintain a high-quality and sharp diamond dressing tool, at regular intervals, the need for 1/8 turn to rotate a single point or with the tip of the trimming tool. The number of rotations can be determined according to the trimming situation, according to experience, at least once a day rotation. For chisel heads and forming dressing tools, they are usually rotated 180 ° before they are dull.

Most cylindrical grinding machines place the part and wheel on a horizontal line. The highest point of the outer circle of the part and the highest point of the outer circle of the grinding wheel are called the parts / grinding wheel contact point. The diamond dressing tool should dress the grinding wheel as close as possible to the part / grinding wheel contact point. It is even more important to dress the grinding wheel of the internal grinding machine with the diamond dressing tool near the highest point of the outer circle of the grinding wheel (ie the grinding wheel contact point).

Applications of Diamond Grinding Wheel

Since diamond abrasive with the characteristics (high hardness, high compressive strength, wear resistance), making it an ideal tool for diamond abrasive grinding hard and brittle materials and carbide in grinding, not only high efficiency, precision high and good roughness, abrasive consumption, long service life, but can also improve working conditions. Metal and non-metallic hard and brittle material is widely used in ordinary abrasive difficult to process low iron content, it is widely used in optical processing, sapphire, watches lenses, glasses, glass, precision ceramic, ferrite, automobile and motorcycle, beauty , aviation, military, cutting tool industry. Such as cemented carbide, alumina ceramic, optical glass, agate gem, semiconductor materials, stone and the like.


So far only ceramic bond diamond wheel can be trimmed on the machine. When using such a grinding wheel, worn too much and the feed rate is too low. Recently, however, there is a resin bonded grinding wheel groove, both with high material removal rate can be trimmed on the production equipment

The classification matrix matrix is a carrier wheel abrasive

The classification matrix matrix is a carrier wheel abrasive and binder, is coated abrasives with flexible leading factors, so as the matrix material must have the following properties:

(1) the matrix has a strong bonding ability on substrate to the "carrier" for the bond of post node agent. At the same time, to stick firmly depends on two factors, one is the sticky journal selection (performance), two is a surface active matrix itself to the size (i.e. fiber type), fabric texture, density matrix

(2) must have a certain flexibility

(3) extending base body must have a certain the strength and rate of smaller matrix in the application, to bear the tension load and alternating load, load shedding and load expansion rot and other force, must make the star strength can meet the needs of the application. The extension rate is a very important performance matrix, the extension of abrasive will kill Off, loss of ability for grinding, abrasive belt, stretching too much. More than grinding the adjustable range of abrasive belt cannot be used.

(4) the surface of the substrate must be almost the whole matrix coated abrasives.

Performance characteristics of the resin grinding wheel on the grinding wheel

(1) Abrasive material:

Cutting grinding wheel abrasive commonly have cut brown jade (A), corundum (wA), corundum (BA), silicon carbide (c), the most commonly used is corundum, corundum because of high hardness, toughness, particle Fengrui, applicability and the price is lower than other abrasive characteristics. Corundum smelting reduction in their adequacy and two points a sand sands, mainly in the chemical composition: Al2O3 content of a sand ≥94.5; Al2O3 content of two sand <94.5%; 85% in general left and right, and the Fe2O3 content of 4-5%; therefore two sand hardness lower than a sand, but the price is low; corundum applicable to all kinds of carbon steel and alloy steel processing in general; corundum higher hardness than corundum, brittle, grinding heat is small, because the price is high, the thermal deformation of the workpiece requires hours of use, there are mixed as abrasive materials for special processing; black corundum Al2O3 content of 70 ~ 85%, Fe203 content of 7 to 9% low hardness, poor cutting forces, but the price is cheap; black silicon carbide high hardness and brittleness good, sharp cutting edge, good self-sharpening performance, good thermal conductivity, there are advantages in processing non-ferrous metals, plastics, rubber and cast iron.

 

(2) abrasive particle size:

Common particle size: 22 # -80 #, fine granularity low cutting efficiency.

(3) Wheel hardness:

Common hardness: P, Q, R; N, S; wheel generally relatively rigid, in order to reduce wheel wear. The hardness of the binding agent how much molding density, firing temperature and firing time and other factors to control.

(4) binding agent:

Commonly used resin binders are: phenolic resin powder, liquid phenolic resin. Powdered phenolic resin technology is good, abrasive molding density slightly smaller number of larger organizations, the price is higher than the liquid phenolic resin; liquid phenolic resin low price, but the material is easy to mix and caking material is not easy to spread evenly, easy to cause localized abrasive hard.

(5) Organization:

Cutting grinding wheel should be slightly larger number of organizations, in order to improve cutting efficiency: too much will affect the strength and common organization No. 3 to No. 7.