The main key component of the horizontal boring and milling machine is the headstock, which is installed on the side of the column. There are also a few manufacturers adopting the thermal symmetry structure of the double column, and the spindle box is placed in the middle of the column. The biggest feature of this structure is rigidity, balance and heat dissipation. It provides a reliable guarantee for high-speed operation of the spindle head. However, the double-column structure is not easy to maintain, which is the reason why there are not many manufacturers in use today. The headstock movement is mostly driven by the motor-driven ball screw. It is the spindle drive core transmission device. It is mostly supported by a static pressure bearing and driven by a servo motor to drive the ball screw. As the spindle speed is getting higher and higher, the spindle heats up quickly. Many manufacturers have adopted oil mist cooling instead of oil cooling to more effectively control the spindle temperature and ensure its accuracy.
The main shaft system has two structural types, one is the traditional mast telescopic structure, which has the characteristics of deep hole and high power cutting; the other is the modern high speed electric spindle structure, which has high speed, fast running speed and high efficiency. The advantages of high precision.
High-speed electric spindles are used more and more on horizontal boring and milling machines. In addition to the spindle speed and accuracy, the internal structure of the spindle box is simplified, and the manufacturing cycle is shortened. In particular, high-speed cutting can be performed. Larger than 10000r/min. The disadvantage is that power is limited and its manufacturing cost is high, especially deep hole processing. The mast telescopic structure has a limited speed, but the precision is not as good as that of the electric spindle. However, it can be used for deep hole machining, and has high power, can be processed at full load, and has high efficiency, which is unmatched by the electric spindle. Therefore, the two structures coexist and the process performance is different, but it provides users with more choices.
A replaceable spindle system has been developed, which has the dual-purpose function of the machine. The user can choose to use according to different processing objects, that is, the electric spindle and the mast can be replaced with each other. This structure takes into account the shortcomings of the two structures and greatly reduces the cost. It is a major innovation in today's horizontal boring and milling machines. The advantages of the electric spindle are high-speed cutting and rapid feed, which greatly improves the accuracy and efficiency of the machine.
The horizontal boring and milling machine runs at a higher speed, the rapid moving speed reaches 25~30m/min, and the maximum speed of the mast is 6000r/min. The horizontal machining center has a higher speed, fast moving up to 50m/min, acceleration of 5m/s2, positional accuracy of 0.008-0.01mm, and repeat positioning accuracy of 0.004~0.005mm.