The maintenance and cutting method of water jet cutting machine

High pressure water jet cutting machine uses high pressure water jet and abrasive to cut metal materials at a very high speed.

 The quality of the cutting surface after the water cutting machine cuts the aluminum alloy plate is good, the surface finish can reach ra25, the positioning accuracy is ± 0.1mm, the repeated positioning accuracy is ± 0.50mm, the dimensional tolerance of the cutting straight line is ± 0.10mm, and the slope of the cut section is less than 0.1mm. The worktable of our water jet cutting machine is 2000 * 4000. The aluminum alloy plate processed by water jet cutting machine can meet the requirements of the above standards. The workpiece cut by water jet does not need to carry out subsequent processes such as grinding, trimming and processing and the cutting of plates with the same thickness and material is about half of that of laser and plasma cutting.

 The cutting accuracy of the laser cutting machine is good. After cutting the aluminum alloy plate, the quality of the cutting surface is good, the surface finish can reach ra25, the positioning accuracy is ± 0.10mm, the repeated positioning accuracy is ± 0.1mm, the dimensional tolerance of the cutting straight line is ± 0.30mm, and the slope of the cut section is less than 0.2mm. Within the range of laser cutting capacity, the laser cutting function can meet the cutting quality standard requirements of aluminum alloy car blanking. And the cutting speed of laser cutting machine is fast. However, a large number of burrs will be produced when the laser cutting machine cuts the aluminum alloy plate with a thickness of more than or equal to 4mm. Subsequent treatment of deburring is required.

 The quality of the cutting surface after plasma cutting machine cutting aluminum alloy plate is worse than that of laser and water cutting machine, and the surface finish should preferably reach ra25. The positioning accuracy is ± 0.05mm, the repeated positioning accuracy is ± 0.50mm, the dimension tolerance of the cutting straight line is ± 0.50mm, and the slope of the cut section is equal to the plate thickness xtg4 ° mm. Plasma cutting machine can not meet the requirements of cutting quality standard for aluminum alloy plate blanking, so it is necessary to add machining process and subsequent grinding and finishing process. Therefore, when cutting aluminum alloy workpiece by plasma cutting machine, 3-5mm machining allowance shall be reserved on one side according to the nominal size of the workpiece, which wastes certain raw materials. If the use function of the workpiece is not affected, the deburring workpiece cut by the plasma cutting machine can also be directly used for assembly welding.

There are two forming methods of aluminum alloy thick plate, one is bending forming, the other is die pressing. The equipment used for bending forming is a bending machine. According to different arc radii, different kinds of bending tires are installed on the bending machine to complete the bending forming. The equipment used for die forming is a press. Molds are made according to different shapes of parts and installed on the press to form. The advantages of the bending machine forming method are universal. A kind of bending tire can often complete the manufacture of a variety of parts. The cost of bending tire is generally one fifth to one tenth of that of the forming die. The pressing depth can be adjusted at any time during the bending forming of bending machine, which is convenient for mold test, convenient and labor-saving for the installation of bending tire. Disadvantages require high operation level and practical experience of workers, and can not complete the forming of complex parts. The advantage of die forming is that it can complete the forming of complex parts. The production efficiency is higher than that of bending machine, and the level of workers is lower. Disadvantages: long mold manufacturing cycle, high cost, difficult mold debugging, high requirements for the stability of mechanical properties of sheet metal, difficult installation, and only one mold can be used. In production, the appropriate forming method should be selected according to the specific situation. If the conditions permit, the bending machine shall be selected as far as possible to reduce the production cost and improve the flexibility of forming.

Abrasive waterejt cutting methods are used for hard materials such as metals, glass, minerals, concrete, glass composites, ceramics, aluminum or silicon oxide. In other words, abrasives are added where pure water cannot cut the material correctly. The abrasive is added to the water knife during the cutting process. In the cutting head, water, air and abrasive are mixed together and forced to pass through the focusing tube at high speed. The generated high-energy jet can be slightly corroded, that is, drilling and cutting, forming materials with large thickness and the highest density, such as metals, ceramics, rocks and even bulletproof glass.

Maintenance items of water jet cutter:

 1. Prepare safety stock parts to avoid lack of parts replacement

2. Correctly manage and use the right tools, and focus on the maintenance of water cutting machine

3. Protect the surface of all parts from damage. If there is scratch, grind it

4. Handle the water seal contact surface carefully, and replace it immediately in case of water leakage or damage


About the maintenance of water jet cutter, there are the following points

Step 1: observe the water flow from the gem nozzle. Open the water flow at low pressure for observation. The water flow should be symmetrical and its width depends on the type of nozzle used. The flow of ruby and sapphire nozzles is slightly wider; The water flow of diamond nozzle is narrower and more coherent. If the water flow begins to widen, it indicates that the nozzle is damaged and should be replaced immediately. Damaged nozzles (or misaligned pipes) can cause internal damage to the cutting head.

Step 2: regularly check the cutting head for signs of wear or damage (often caused by accidental contact with parts or fixtures). For example, accidental contact of the sand tube with the fixture can damage the nozzle nut and internal parts that keep the mixing tube aligned.

Step 3: inspect and replace the abrasive conveying system regularly. Ensure that no part of the sand conveying system below the bottom of the micro hopper is exposed to air. During this inspection, disconnect the sand conveying pipeline from the joint at the bottom of the micro hopper, manually open the jet and stick your thumb to one end of the sand conveying pipeline. You will feel that there is sufficient (but not excessive) vacuum, which may dent the tip of your thumb. Insufficient vacuum may indicate that the inlet of the cutting head is blocked or the sand conveying pipeline has cracks, which must be solved to give full play to the efficiency of the system.

 Check the system and keep it in operation, so as to make the operation of water jet cutter more effective and prolong the service life of its components