You must know the 6 cool tricks for cutting fluids!
January 13, 2022
Most of the southern regions will gradually enter into hot weather. However, in the eyes of machine-processing people, what you need to face all the year round is the same "hot" cutting fluid. How to use cutting fluid reasonably and control temperature is a necessary skill. Let's take a look at the 6 major ways to cool the cutting fluid at high temperatures. Under this condition, the pressure method is usually used to force the cutting fluid into the cutting area, so as to take away the heat generated by the tool, workpiece, and chips due to friction and deformation. Continuous application of cutting fluid is better than intermittent application of cutting fluid. Intermittent application of cutting fluid will generate thermal cycles, which can lead to cracks and chipping of hard and brittle tool materials (such as cemented carbide tools). Intermittent use of cutting fluid will not only shorten the tool life, but also make the working surface rough and uneven.
1. Manual refueling method for cooling fluid Solid or paste lubricants can be applied or dripped onto the tool or workpiece with a brush or brush (mainly when tapping and die sleeve threads). Recently, a portable liquid feeder has been developed, which atomizes the lubricant through pressurization and sprays it on the tool and the workpiece. On a machine tool without a cooling system, if the number of drilling or tapping is not large, manual oiling is an effective method. When two different processes are to be completed on the same machine tool, manual oil can be used in conjunction with the overflow cooling system on the machine tool. 2. Cutting fluid cooling and overflow method The most common method of using cutting fluid is the overflow method. The cutting fluid is pumped into the pipeline with a low-pressure pump, and flows out of the nozzle through the valve, which is installed near the cutting area. After the cutting fluid flows through the cutting area, it flows to different parts of the machine tool, and then is collected in the oil collecting pan, and then flows back to the cutting fluid tank from the oil collecting pan for recycling. Therefore, the cutting fluid tank should have enough volume to allow time for the cutting fluid to cool down and allow fine chips and abrasive particles to settle. Depending on the type of processing, the volume of the cutting fluid tank is about 20-200L, and individual processing is larger, such as deep hole drilling and powerful grinding, etc., the cutting fluid tank can reach 500-1000L or more. A coarse filter should be installed in the oil collecting pan to prevent large cuts from entering the cutting fluid tank, and a fine filter should be installed at the oil suction port of the pump. For grinding, grinding, deep hole drilling, deep hole boring and other machine tools, due to the high surface quality of the processed workpieces, finer grinding debris, grinding wheel particles and cutting particles must be removed. For example, gun drilling deep hole processing requires 10um. The filter paper is filtered. The use of filtering equipment can avoid excessive contaminants or excessive metal particles in the cutting fluid, which helps to keep the cutting fluid clean and prolong the life cycle of the cutting fluid. Modern automated machine tools are generally equipped with cutting fluid filtration, separation, and purification devices. With the overflow method, the cutting fluid can continuously flow to the cutting area and flush away the chips. The flow of the cutting fluid must be larger to make the tool and the workpiece submerged by the cutting fluid. 3. Cutting fluid cooling and high pressure method For some processing, such as deep hole drilling and sleeve hole drilling, high-pressure (pressure 0.69-13.79MPa) cutting fluid system is commonly used to supply oil. Deep hole drilling uses a single-edged drill, which is similar to boring, except that there is a channel for cutting fluid inside the drill. Hole drilling is a method of drilling a cylindrical hole in the workpiece but leaving a solid cylinder. When the tool enters the workpiece, the drilled solid cylinder passes through the hollow cylindrical tool head, and the pressure pump is used to send the cutting fluid around the tool, forcing the chips to flow out from the center of the tool. The cutting fluid used for sleeve drilling must have good extreme pressure and sintering resistance. The viscosity should be very low to flow freely around the tool. It should also have good oiliness to reduce the gap between the tool and the workpiece, and between the tool and the chips. Coefficient of friction. The main problem of deep hole drilling is how to maintain sufficient cutting fluid flow in the cutting area. One way is to use drill chip flutes as the passage of the cutting fluid. The pressure of the cutting fluid is 0.35-0.69MPa. The rotating sealing sleeve flows into the drill bit and then directly enters the cutting area. The cutting fluid flowing out of the hole helps to remove the chips. In deep hole drilling, the use of oil hole drilling is a big improvement compared with the overflow method, and the life and productivity of the drill bit have been greatly improved. The high-pressure method helps the cutting fluid reach the cutting area, and is sometimes used on other machine tools. Grinding makes the high-pressure nozzle beneficial to the cleaning of the grinding wheel. 4. Cutting fluid cooling spray method The cutting fluid can be sprayed on the tool and the workpiece in the form of airborne oil mist. The cutting fluid passes through a small nozzle and uses compressed air with a pressure of 0.069-0.552MPa to disperse the cutting fluid into small droplets and spray it into the cutting area. In this case, water-based cutting fluid is better than oil-based cutting fluid, because the oil mist of oil-based cutting fluid pollutes the environment, which is harmful to health, and it is easy to integrate larger oil droplets. The spray method is most suitable for machining with high cutting speed and low cutting area (such as end milling). Use cutting fluid with good cooling performance. Small droplets can quickly evaporate and remove the heat when they come in contact with hot tools, workpieces or chips. Spray cooling does not need splash plate, oil collecting pan and oil return pipe, only small spherical shape is used, and the workpiece is dry, even if there is a little oil, it is easy to wipe dry. 5. Cooling liquid cooling method for cutting fluid There are many types of cooling liquid cooling methods, such as nitrogen, argon, carbon dioxide and other gases can be compressed into liquid and placed in a steel cylinder. Freon gas can be compressed into a liquid by mechanical devices and released during use. It passes through a regulating valve and is directly injected into the cutting area by a nozzle. , Relying on gasification to absorb heat to cool tools, workpieces and chips. This method has a very good cooling effect and is suitable for cutting difficult-to-machine materials such as stainless steel, heat-resistant steel, and high-strength alloy steel, and can greatly improve tool durability. 6. Centralized supply system of cutting fluid For large and medium-sized mechanical processing plants, where possible, a centralized circulation system should be considered to supply cutting fluid to multiple machine tools, but each machine tool must use the same cutting fluid. Several grinders can handle the wear debris with a coupled conveying system. Concentrated processing of fine chips and wear debris wetted by cutting fluid can reduce manpower processing and improve working conditions.
