Views: 4 Author: Site Editor Publish Time: 2022-01-10 Origin: Site
As the old saying goes, "To do a good job, you must sharpen your tools." Today, he is given a broader meaning in modern manufacturing. In order to improve processing efficiency, it is very important to continuously optimize the "sharp tool" - CNC cutting tools. The following is a brief introduction to several ways to optimize props.
1. "Benefit" its material, change the cutting speed
Tool suppliers are constantly developing tools with longer service life and faster cutting speed to achieve higher feed rates and improve machining efficiency. To change the cutting speed, the key is to change the cutting material wood and surface coating.
At present, the choice of cutting tool material suppliers mainly focus on cemented carbide and part of CBN, and do not increase research and development efforts, launch new products.
1）Cemented carbide products:
The new material AC810P/AC820P has increased the cutting speed to V=350-390m/min on the SCM420 drive shaft and CVJ (ball cage) outer edge through technical innovations in base metal and layers. At the same time, with excellent collapse resistance, in the processing of SCM425 gear, can achieve 5mm cutting depth, feed up to 0.5mm/ REV, is the original material life 1.5~2.7 times. The AC810P material also breaks the original wet machining tradition and can be applied to dry machining without using cutting fluid. It improves the processing efficiency and service life while reducing the environmental load material design.
For the more difficult to process in the automotive parts of high hardness and quenching parts such as gear output shaft, clutch and other cast iron, powder metallurgy based cylinder and piston hole, valve seat ring and other products have higher requirements on life and accuracy. CBN tool in high speed, high efficiency, high precision performance absolutely give force!
For example, the processing speed of BN1000 material can reach V=200-300m/min when finishing the above-mentioned hardened steel parts. This is equivalent to the processing speed of cemented carbide materials for ordinary steel pieces. The BN2000 can increase the cutting depth to 0.3mm. In the milling of automobile abrading tools, BN700/BN7000 round edge milling blade with BRC cutter rod can achieve 150~400m/min and 200~800m/min ultra-high speed finishing when SKD hardened to HRC4 7~ 52 material and NAK pre-hardened steel HRC40~50 material respectively. The processing time is shortened 3~5 times, and the surface finish is excellent.
The linear speed can be directly increased from 500m/min to 2000m/min when machining the cast iron material of cylinder block (under the premise of tool structure permitting), making high-speed and efficient processing become worthy of the name.
In the machined valve seat, hard alloy is used for areas below Vc=100m/min.Cermets can also be processed, but when Vc=120m/min or more, the wear speed rapidly leads to the deterioration of surface roughness and the increase of burr. And CBN can be in the Vc=100-290m/min high-speed processing field has excellent surface roughness, high wear resistance, strong ability to suppress burrs and other characteristics, can be at ease in processing.
2. "Benefit" its clamping, to achieve high cutting speed and large feed.
The tool holder system is the connection between the machine tool spindle and the tool. It carries the precision and rigidity of the spindle and the rigidity of the tool holder itself. The dynamic balance type, clamping force and clamping precision are the necessary conditions to achieve high speed and high efficiency machining
1) High speed and high precision grip handle
For cutting tools with diameter of φ 20mm or less, especially small cutting tools with diameter of φ 0.25~12mm, high efficiency and high precision machining and excellent surface finish need to be achieved through high speed machining, which puts forward more stringent grade requirements on the grip accuracy and dynamic balance performance indicators. The runout accuracy of BIG's clamping port is 0.001mm, the runout accuracy of 4 times diameter is 0.003mm, and the accuracy of jacket is AA. The handle is processed by dynamic balance experiment, the highest speed can reach 40000r/min, and the standard configuration of center water, fully meet the requirements of high-speed and high-precision drilling, reaming and milling. The aluminum alloy cylinder was drilled with φ 8.5 (5D), and the processing parameters were n=7500r/min, F= 0.7mm/ Rev, f= 5250mm with NHGS diamond coated bit. The efficiency was 3~4 times higher than that of general processing. At the same time, the aperture accuracy is stable.
2) Re-cut strong grip handle
This kind of handle is mainly for φ 20~50mm large diameter cutting tools. Because this diameter range belongs to the rough machining category, it has higher requirements on the rigidity and clamping force of the shank. BIG's HMC Strong shank series features a unique slit mechanism, a thickened grip, good rigidity, and an ultra-high torque of 300Nm. Another BBT high speed double force holder series from BIG can meet the needs of high speed strong cutting with clamping accuracy between 0.005 and 0.01mm. In the case of BBT spindle matching can make the taper of the handle and flange face on both sides of the close match, the rigidity can be enhanced 3~4 times, to achieve strong efficiency cutting, and get good deep hole processing effect.
In the field of automobile processing, especially in the process of mass production, the precision of the tool, cutting speed and life directly affect the operation rate of the production line, processing rhythm, and even the final production efficiency. According to the survey, nearly 70% of users in China tool cost accounted for 2%~3% of the total production cost. Although the proportion is not very high, but the choice of reliable, applicable and efficient tool products, but can significantly reduce the total cost of production.