What Is Gear Grinding?

Grinding, pronounced mó xu, is a mechanical method of removing material. Refers to the processing method of removing excess material on the workpiece with abrasives and tools. Grinding is one of the more widely used material removal methods.

Grinding

Utilizing high-speed rotation

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

(1) Grinding speed is very high, it can reach 30m 50m per second;

Grinding refers to

A grinding machine is a machine tool that uses a grinding tool to grind the surface of a workpiece.

Most of the grinding machines use high-speed rotating grinding wheels for grinding, and a few use oilstone, abrasive belts and other abrasive tools and free abrasives, such as

Grinders can process materials with higher hardness, such as hardened steel, cemented carbide, etc .; they can also process brittle materials, such as glass, granite. The grinding machine can perform high-precision and small surface roughness grinding, as well as high-efficiency grinding, such as powerful grinding.

With the increase in the number of high-precision, high-hardness mechanical parts, and the development of precision casting and precision forging processes, the performance, variety and output of grinding machines are constantly improving and increasing.

Grinding is widely used and is one of the main methods for precision machining of machine parts. However, due to the high rotation speed of the grinding wheel, the grinding wheel is relatively hard, brittle, and cannot withstand heavy impacts. Accidental improper operation will cause very serious consequences. Therefore, the safety and technical work of grinding processing is particularly important. Reliable safety protection devices must be adopted, and the operation must be focused and ensured. In addition, the fine sand and metal chips splashed on the workpiece of the grinding wheel during the grinding will hurt the workers' eyes. If workers inhale this dust in large quantities, it will be harmful to the body, and appropriate protective measures should also be taken. When grinding, you should pay attention to the following safety technical issues.

The grinder should have a special person responsible for maintenance and use, and regular maintenance to ensure that the machine tool is in good condition.

1. After the operation is completed, all parts of the machine, especially the sliding parts, should be wiped clean and oiled.

2.Clear

With abrasive and

Grinding wheel has the largest amount of grinding tools and the most widely used surface. It rotates at high speed during use. It can perform rough grinding, semi-precision grinding, slotting and cutting on metal, non-metal workpieces with various shapes such as outer circle, inner circle and flat surface. Wait.

There are many types of grinding wheels.

1. According to the abrasive used, it can be divided into ordinary abrasives (corundum, silicon carbide, etc.), natural abrasives, superhard abrasives (diamond, cubic boron nitride, etc.);

2. According to the shape, it can be divided into flat grinding wheel, beveled grinding wheel, cylindrical grinding wheel,

Grinding installation process

The first step is to check the safety and quality of the grinding wheel during installation. The method is to tap the side of the grinding wheel with a velvet hammer (pen can also be used), and the sound is clear.

(1) Location problem

Where is the grinder installed? This is the first thing we need to consider during the installation process. Only by selecting a reasonable and suitable position can we perform other tasks. It is forbidden to install the grinder in a place directly facing the nearby equipment and operators or people often pass by. Generally, larger workshops should set up a dedicated grinder room. If it is really impossible to set up a special wheel machine room due to the topography of the factory building, a protective baffle with a height of not less than 1.8m should be installed on the front of the grinder, and the baffle plate must be firm and effective.

(2) Balance problem

The imbalance of the grinding wheel is mainly caused by the inaccuracy of the manufacturing and installation of the grinding wheel, which makes the center of gravity of the grinding wheel not coincide with the rotation axis. The harm caused by the imbalance is mainly manifested in two aspects. On the one hand, when the grinding wheel rotates at high speed, it causes vibration and easily causes polygonal vibration marks on the workpiece surface; on the other hand, the imbalance accelerates the vibration of the spindle and the wear of the bearing, which is serious This can cause the wheel to rupture and even cause an accident. Therefore, it is required that the sand office building with a straight length of 200mm or more should be statically balanced after being installed with a chuck. After the dressing or dressing is found to be unbalanced, the static balancing should be repeated.

(3) Matching problem

The matching problem mainly refers to the installation and matching of the chuck and the grinding wheel. According to the standard requirements, the diameter of the grinding wheel chuck must not be less than 1/3 of the diameter of the office building where the sand is installed, and the corresponding regulations stipulate that the grinding wheel should be replaced with a new one when the diameter of the grinding wheel is worn to 10mm larger than the diameter of the chuck. In this way, there is a problem of matching the chuck with the grinding wheel. Otherwise, such a situation will occur. The "large horse drawn cart" causes waste of equipment and materials; the "small horse drawn cart" does not meet the safety requirements and is likely to cause personal accidents. Therefore, the reasonable matching of the chuck and the grinding wheel can save equipment and cut materials on the one hand, and meet the requirements for safe operation on the other. In addition, a cushion with a diameter greater than 2mm and a thickness of 1mm ~ 2mm should be installed between the grinding wheel and the chuck.

(4) Protection issues

The protective cover is the most important protective device of the grinding machine, and its role is: when the grinding wheel is damaged during work, it can effectively cover the grinding wheel fragments to ensure the safety of personnel. The shape of the grinding wheel cover is round and square. The maximum opening angle is not allowed to exceed 90 °. The material of the cover is steel with a tensile strength of not less than 415N / mm2. When replacing a new grinding wheel, the installation of the protective cover must be firm and reliable, and the protective cover must not be dismantled or discarded.

The blocking screen is one of the main protective accessories of the grinding machine. The protective cover has an opening greater than or equal to 30 above the horizontal plane of the main shaft. This device must be installed. Its main function is to block flying during the grinding process to avoid injury. Operator. It is installed at the positive end of the protective cover, the width should be larger than the width of the protective cover of the grinding wheel, and it should be firmly fixed on the protective cover. In addition, the clearance between the peripheral surface of the grinding wheel and the baffle should be less than 6mm.

(5) Bracket problem

The bracket is one of the commonly used accessories of the grinder. According to the regulations, the grinder with a diameter of 150mm or more must be provided with an adjustable bracket. The distance between the grinding wheel and the bracket should be less than 1/2 of the smallest shape of the workpiece to be ground, but the maximum should not exceed 3mm.

(6) Grounding problem

Grinders use power lines, so the enclosure of the equipment must have good grounding protection. This is also one of the important factors prone to accidents.

Grinding process

(1) Side grinding problem

In the daily use of the grinding machine, we often find that some operators can grind the side of the grinding wheel at will regardless of the type of the grinding machine and the type of the grinding wheel. This is a violation of the safety operation regulations. behavior. According to the regulations, the grinding wheel with a circumferential surface as the working surface should not be used for grinding on the side. This type of grinding wheel has a large radial strength and a small axial strength. When the operator exerts too much force, it will cause the grinding wheel to break and even hurt people. This behavior should be prohibited during use.

(2) Positive operation problems

In daily use, many operators are always accustomed to operating against the grinding wheel, because the force can be used in this direction. In fact, this behavior is a particularly prohibited behavior in the operation of the grinding machine. According to the operating regulations, when using a grinding machine to grind a workpiece, the operator should stand on the side of the grinding wheel, and do not operate on the front of the grinding wheel, so as to prevent the grinding wheel from flying out or the grinding wheel breaking and hurting people when the grinding wheel fails.

(3) Problems with hard operation

During the use of the grinder, some operators, especially young operators, are trying to grind faster and use too much force, which is an extremely unsafe operation. The flat body of any grinding wheel has a certain strength. Doing so may cause the grinding wheel to break and even fly out and hurt people, which is also a behavior that should be prohibited.

(4) Common operational issues

In actual daily operations, there are also situations like this: Some people rush to work at the same time and rush to work, and two people share a grinder to operate at the same time. This is a serious illegal operation and should be strictly prohibited. When a grinding machine is not enough, you can use the method of adding a grinding machine. It is absolutely not allowed to share a grinding machine at the same time.

Grinding replacement process

(1) Wear problems

Any grinding wheel has its certain use and wear requirements. If the wear reaches a certain level, it must be replaced with a new one. It can not be used in order to save material, it is an extremely unsafe violation. Generally, when the grinding wheel wears to a diameter 10mm larger than the diameter of the chuck, it should be replaced with a new one.

(2) Validity issue

The new wheels obtained from the warehouse are not necessarily qualified wheels, and even new wheels purchased from manufacturers are not necessarily qualified wheels. Any grinding wheel has a certain expiration date. If it is used within the expiration date, it is a qualified grinding wheel; if it is used beyond the expiration date, it is not necessarily a qualified grinding wheel. The regulations stipulate that "the grinding wheel should be used within the validity period, and the resin and rubber bond grinding wheel must be subjected to a rotation test after storage for one year before it can be used".

(3) Texture issues

In the course of use, if a local crack is found on the grinding wheel, stop using it immediately and replace it with a new one, so as not to cause the accident of the grinding wheel injury.

Grinding other

(1) Environmental issues

Grinding machines should generally be equipped with special grinding machine rooms, and it is strictly prohibited to pile flammable and explosive items near the grinding machine room or the grinding machine to avoid fire or explosion accidents, and other parts or items should not be placed in the vicinity of the grinding machine.

(2) Management issues

The grinder should have a special person in charge. When anyone who is not in the unit wants to grind an object on the grinder, it needs the permission of the full-time person in charge and strictly observes the safety operation regulations. It is strictly forbidden for anyone to use the grinder without permission. In addition, the replacement of the grinding wheel should also be carried out by a special person. It is forbidden to replace or install the grinding wheel without permission.

(3) Closing problems

After the operator stops working, the car should be closed immediately. It is forbidden to idle the grinder without using or managing it. In addition, the medium and short wave turbines should be kept clean after use.