Speaking of burrs, let's first understand what burrs are. Burr refers to the extremely fine microscopic metal particles formed on the machined surface of the workpiece. They are chips or tiny metal particles formed in metal casting, grinding, cutting, milling and other similar cutting processes.

Different machining methods will produce different burrs. According to different processing methods, burrs can be roughly divided into:

1. Casting burr: excess material generated at the joint of the mold or at the root of the gate. The size of burr is generally expressed in millimeters.

2. Forging burr: Due to the plastic deformation of the forging material, it is produced at the joint of the metal mold. Electric welding and gas welding burr: electric welding burr is the burr that the filler at the weld protrudes from the surface of the part; Gas welding burr is the slag that overflows from the incision when cutting off the gas.

3. Stamping burr: During stamping, there is a gap between the punch on the die and the lower die, or there is a gap between the tools, resulting in burr due to die wear. The shape of stamping burr varies according to the material, thickness, gap between upper and lower dies and the shape of stamping parts.

4. Cutting burr: Machining methods such as turning, milling, planing, grinding, drilling and reaming will also produce burr. Burrs produced by various machining methods have different shapes under different tools and process parameters. Plastic molding burr: the burr produced at the joint of plastic mold, just like casting burr.

Because of the gap at the joint between molds, burrs are produced, and the perfect combination between molds is not yet achieved, so it is difficult to completely avoid burrs. However, with the development of metal materials in the direction of high hardness, high strength and high toughness, the whole components in mechanical products are more and more complex and diverse, and it is more and more difficult to deburr. With the development of science and technology, the performance of our products is improving iteratively, and the requirements for product quality are becoming more and more strict, so it is more and more important to remove the burr of the workpiece.

The appearance of burr not only affects the appearance of products, greatly reduces the quality standard of metal workpieces, but also affects the assembly, service performance and service life of products. Therefore, in the process of machining, we should try to choose good tools to prevent burrs, such as the milling cutter produced by Fulandi, which has a good finish and can effectively avoid burrs.

In order to remove burrs, besides choosing good tools to avoid them, a second deburring operation is usually needed. Three deburring and edge finishing of precision parts may account for 30% of the cost of finished parts. In addition, the secondary finishing operation is difficult to be automated, so burr really becomes a very difficult problem.

The traditional manual deburring operation is difficult to meet the requirements of the above development, and various mechanized and automatic deburring new technologies and processes have emerged. Next, Fulan will bring you the following deburring methods:

1, deburring of stamping die

Burr removal is achieved by making a die with a punch. Deburring of stamping die requires a certain manufacturing cost of rough die and fine die, and plastic die may be made, and the module may need to be replaced for a long time. It is suitable for products with simple parting surface, and the efficiency and effect of deburring are better than that of manual method.

2. Grinding and deburring

Grinding deburring is a method of deburring by vibration, sandblasting and rolling, which is also widely used by enterprises at present. The problem of grinding deburring is that sometimes it is not very clean, and it may need subsequent manual treatment or other ways to deburr. This method is suitable for small batch products.

3, high temperature deburring

High temperature deburring is also called thermal deburring and thermal explosion deburring. This is a method that a certain reactive gas is introduced into the equipment furnace, and then the gas explodes instantly under the action of a certain medium and condition, and the energy generated by the explosion is used for dissolution and deburring. The equipment required by this method is expensive, usually reaching more than one million yuan, and the requirements for operation technology are also very high. Burr removal efficiency is low, and it will also cause side effects such as rust and deformation. Thermal explosion deburring is mainly used in some high-precision parts, such as automotive aerospace and other precision parts.

4. Freezing and deburring

This is a method to quickly embrittle burrs by sudden drop of temperature, and then to remove burrs by spraying projectiles. Freezing deburring is suitable for products with small burr wall thickness and small workpiece. The price of the whole set of equipment is not low, about 200,000 to 300,000.

5, chemical deburring

Chemical deburring method is a process of automatic and selective deburring of parts made of metal materials by using electrochemical reaction principle. Suitable for those internal burrs that are difficult to remove, especially for removing small burrs on products such as pump body and valve body.

6, engraving machine deburring

It is not very expensive to remove the burr on the workpiece with engraving machine, usually only tens of thousands of RMB, which is suitable for removing the burr with simple spatial structure and simple position.

7, electrolytic deburring

Method of removing burrs from metal parts by electrolysis. Fix the tool cathode (usually brass) near the burr part of the workpiece, leaving a certain gap between them. During machining, the tool cathode is connected to the negative pole of DC power supply, and the workpiece is connected to the positive pole of DC power supply. Let the low-voltage electrolyte flow between the workpiece and the cathode. After the DC power supply is turned on, the burr will be dissolved and removed by the anode and taken away by the electrolyte.

Advantages: it is used to remove burrs in hidden parts or parts with complex shapes, with high efficiency, and the time is generally only a few seconds to dozens of seconds. Suitable for deburring and chamfering gears, connecting rods, valve bodies and crankshaft oil circuits.

Disadvantages: the parts are also electrolyzed near the burr, and the surface will lose its original luster and even affect the dimensional accuracy. Electrolyte is corrosive, so it needs to be cleaned and rustproof after deburring.

8, ultrasonic deburring

The propagation of ultrasonic waves can also produce instantaneous high pressure, which can be used to remove burrs on parts. This method has high precision and is mainly used to remove some microscopic burrs that can only be observed through a microscope.

9, high pressure water jet deburring

Use the instantaneous impact of water to remove the burrs and flash after processing, and at the same time achieve the purpose of cleaning. It is divided into two types: workpiece moving type and nozzle moving type.

Movable workpiece-low cost, suitable for deburring and cleaning simple valve body. Its disadvantages are that the matching degree between the nozzle and the valve body is not ideal, and the deburring effect of the horizontal hole and inclined hole on the valve body is not good.

Nozzle movement-CNC control can effectively adjust the distance between the nozzle and the burr part of the valve body, and effectively correspond to the burr of the horizontal hole, inclined hole and blind hole on the valve body, but this equipment is expensive.

Advantages: good removal effect and high speed.

Disadvantages: Simple equipment is not ideal, and ideal equipment is not cheap.

10, deburring of electromechanical integration device

The mechatronics device comprehensively uses the latest research results of machinery and precision machinery, microelectronics and computers, automatic control and drive, sensors and information processing, artificial intelligence and other disciplines. Typical parts include aluminum hub, inverter housing, synchronizer housing, synchronizer gear hub, bearing cover, cylinder block, valve body, valve cover, output shaft, engine gear, etc.

Advantages: moderate cost, good effect, high precision and high efficiency.

Disadvantages: in the development stage, it has not reached the level of popularization, and it needs very accurate data support.

1 1, magnetic deburring

Using the unique magnetic field distribution, a strong and stable magnetic induction effect is produced, so that the magnetic steel needle and workpiece can be fully ground in all directions and angles, and burrs can be quickly removed.

Advantages: it has special effects on complex shapes, porous cracks, internal and external threads, etc.

Disadvantages: For products with magnetism, it is easy to destroy the magnetism of the products themselves, so use it with caution.

12, manual deburring

Manual deburring is also used by most small manufacturers at present. Most of them are small burrs, and the burr removal rate is not high, as long as there are no burrs.

Tools used for manual deburring used to be files, scrapers, sandpaper, etc. But now it is mainly an edge trimmer.

Advantages: flexible labor, and burr on different parts of the workpiece can be removed by changing different tools.

Disadvantages: the labor cost is expensive, the efficiency is low, and it is not easy to remove some cross holes and complex workpieces.

13, deburring with hand tools.

This is not much different from manual deburring, but the things used are different. Manual deburring, deburring with cold tools. Here are mainly some tools. For example, grinding machines, electric drills and other tools, together with milling cutters, drill bits, grinding heads and other materials, can also achieve deburring and chamfering. Most workpieces can be deburred by different tools.

Advantages: high flexibility, can adapt to the polishing of most workpiece environments.

Disadvantages: slow speed, easy to cause certain losses to the workpiece.

In addition, there are other deburring methods. Without relevant data, I won't list them one by one.

14, process deburring

Basic measures to avoid burr in process design

1), adopt reasonable machining methods: in the process of metal cutting, the size and shape of burrs produced by various machining methods are different, so in the process design, we should try to choose the machining method with smaller burrs. For example, when machining a plane, the effect of forward milling is better than that of reverse milling.

2) Reasonably arrange the processing sequence: when arranging the processing sequence of parts, try to arrange the process with large burrs in the front and the process with small burrs in the back, and use the processing of the next process to remove the burrs produced in the previous process. For example, it is more reasonable to change the general machining sequence of turning first and then milling into milling first and then turning.

3) Reasonable choice of walking direction: According to the angle effect of burr, when cutting metal, the outlet should be located at a larger angle to reduce the burr. At the same time, it should also be noted that the cutting edge is located in the part where burrs are easy to remove, so as to reduce the cost of deburring.

4) Reasonable selection of cutting parameters: In the process of cutting parts, all machining methods that produce large chips will produce large burrs. Because when large chips are produced, the cutting resistance increases, the cutting heat increases, the tool wear intensifies, the durability decreases, and the plastic deformation of the workpiece material intensifies, thus making the burr larger. Therefore, in the processing of parts, the burr is generally reduced by reducing the cutting depth and tool feed, especially the precision machining of parts.

5) Reasonable arrangement of heat treatment process: Reasonable arrangement of heat treatment process in different stages of the machining process can change the physical and mechanical properties of workpiece materials such as hardness and elongation, and reduce burrs generated in the machining process of parts. For example, in the production of batch parts, the machining of snap ring groove of shaft parts will produce more burrs if it is ground once with a forming grinding wheel after heat treatment.

6) Machining with accessories: In the process of cutting parts, various accessories can be used at the cutting edge of the parts, such as auxiliary brackets, mandrels or low-melting alloy fillers. It is used to improve the rigidity of the machined parts at the cutting edge and reduce the cutting deformation, thus reducing the generation of burrs at the cutting edge.

In the process of machining, burr is inevitable, so it is best to solve the burr problem from the process and avoid too much manual intervention. The use of Frandi high-gloss chamfering end mill can reduce the space for burr generation and effectively remove burr, which is also a very suitable method for burr removal.