Tool use and maintenance of Scarifier cutter

Tools and practices

It seems simple, operational efficiency and the milling depth and speed of the advance. Large milling deep, full speed ahead seems to be most productive time, but in reality not the case. Because the milling depth increased, and forward speed is bound to decrease. A 2 million milling machine milling depth and forward speed as shown in Figure 3. In addition, the milling deep and large, forward speed is small, then the small size milling waste on the tool wear is also more serious, single-output also dropped the knife. Figure 4 represents the single-Segment of a particular model to production and milling of deep relationship. Can be seen, sometimes layered milling but more economical.

Tool Wear

Tools, in particular, Cutter, life is very low, in the process of breaking ground with the ground and waste generated intense friction, wear and tear quickly. Asphalt concrete pavement is a high consistency of asphalt binder, heated at high temperature minerals in materials with a variety of forced mixing, paving, rolling made. Asphalt concrete pavement material is mixed materials, energy spectrum analysis know-main component elements are silicon, calcium, aluminum, carbon, potassium, iron and other elements, in which content is more silicon and calcium. Posed by chemical substances are mainly quartz (silica), calcite (calcium carbonate, dolomite (calcium and magnesium) (carbon dioxide), kaolin (Hello, 2SiO, 2HO) and so on. A variety of materials structure and morphology and hardness shown in Table 1 .

Can be seen from Table 1, the road material contains a very high hardness of quartz, the hardness near the carbide. Figure 5 is a carbide tip (tungsten cobalt) wear scanning electron micrographs. A clear direction pits and scratches, and this is hard quartz particles on the alloy particles produced by wear and tear tip. Figure 6 is to use 45 steel knife handle made of wear and tear after the scanning electron micrographs, near the tip Department has significant scratches and furrows. This should be tungsten carbide alloy cutting tip assume their tasks, because of the shape of the tool, the installation location and poor working conditions, resulting in knife handle some direct contact with the pavement material, friction wear.

As the shank itself hardness lower than the tip, they are often the first to be abrasive. Through the above analysis we can see that a reasonable tool wear mainly occurred in the upper tip and the knife handle. In order to Blade wear uniform, knife cut into the ground, Blade tip path plane of the axis is not, there is a certain angle, prompting Cutter cut into the ground at the same time, knife block hole rotation, uniform wear and tear. Normal wear and tear process shown in Figure 7, such wear and tear conditions to maximize the extended tool life. But in the actual construction process, the cutter head often can not achieve the desired state of wear and tear, resulting in the following non-normal wear and tear, as shown in Figure 8.

Figure 6-45 steel shank worn scanning electron micrographs

Shank excessive wear and tear of road milling too soft materials or when the milling chamber stacker too prone to this situation. Tip hardness have enough surplus to connect tip of the knife handle part of the excessive wear and tear, if not immediately replaced, wear insufficient to support the knife handle was broken cutting tip, and then began to wear a knife block, causing greater damage to the machine. This occurs should immediately check the conveying belt speed, if there is no question I will replace the cutter head, the use of larger diameter at the bottom tip of the cutter head, the effective protection of knife handle.

Partial sharpening head in the milling process does not rotate, only on one side produces wear and tear, will result in eccentric wear. Causes partial wear more complex and may include: watering enough, leading to overheating tool; knife block excessive wear and tear; milling high levels of sticky asphalt material, the use of light Segment; small milling waste into the knife handle and spring up between the and so on. Eccentric wear of the cutter head is also needed to replace.

Crack tip suddenly encountered in the milling process of a hard object, such as steel, Manhole cover, large pieces of cement and so on, tip easy to crack. Cutter crack easily after the wear and tear should be replaced immediately.

From the above analysis we can see that to reduce tool wear, reduce downtime, improve economic efficiency, needs to be done: a reasonable selection of tools, the tool and engine power, milling pavement materials, milling depth and forward speed to match; adequate watering Segment temperature reduction, and efficient conveying systems to reduce the milling chamber reactor materials.

Replacement Tool

Tool replacement for two reasons. First of all, with the tip wear, tip diameter and larger, resulting in reduced cutting ability, which also reduces the machine's operating efficiency. Second, the worn tool tip led to a different cutting diameter, milling off the road is not flat, reducing the quality of the machine operation. Although the delay in the replacement of tools to make it in the worn state to continue its work, you can save the cost Cutter, but the blunt of the cutter head will reduce the pace of work and reduce milling yield. Therefore, the timely replacement of worn tool is beneficial to increase economic efficiency.

The replacement of a specific time is felt by the manipulator by the vibration of the machine and observation to determine the road surface after the milling tool wear. When they find the machine vibrations increase, milling after the roads are rugged, you need to stop checking Segment. Described above is not found in the normal wear and tear and normal wear blunt Segment Segment Segment extreme right), on the need for timely replacement. Note that replacement must use copper hammer typing, to prevent the alloy crack Cutter Knife Block Knife Block replacement need to mark lines to assess the wear and tear. When the flag when the line was finished grinding, you need to replace the knife block.