Motorized spindle and pull rod mechanism thereof

Abstract

The invention discloses a pull rod mechanism of a motorized spindle and the motorized spindle. The pull rod mechanism comprises a shaft core, a pull rod, a spring gland and a spring component, whereinan axial penetrated inner hole is formed in the shaft core; the pull rod has an upper end and a lower end which are opposite, a bulge is arranged on the peripheral surface, adjacent to the upper end,of the pull rod, and the lower end and the bulge of the pull rod are positioned in the inner hole of the shaft core; the spring gland is fixed in the inner hole of the shaft core, is sleeved on the pull rod, and is positioned between the lower end and the bulge of the pull rod; the spring component is contained in the inner hole of the shaft core and comprises at least one left-handed disc springs type cylindrical spiral spring and at least one right-handed disc springs type cylindrical spiral spring, and the left-handed disc springs type cylindrical spiral spring and the right-handed disc springs type cylindrical spiral spring are sleeved on the pull rod; and the two ends of the spring component are respectively butted against the bulge of the pull rod and the spring gland. The pull rodmechanism has a precise dynamic balance structure and can effectively prolong the service life.

Description

technical field [0001] The invention relates to the technical field of electric spindles of machine tools, in particular to a pull rod mechanism of an electric spindle and an electric spindle using the pull rod mechanism. Background technique [0002] With the demand for economic development and technological take-off, more and more new technologies are emerging, and the machining industry is also emerging, especially the technological innovation of the leading spindle industry is very obvious. With the aerospace (aluminum alloy, titanium alloy), automobile, precision mold (graphite electrode, copper electrode), heavy industry (large casting, steel), 3C (aluminum alloy, plastic) and other industries, the processing efficiency, processing cost and processing Accuracy requirements, the focus of spindle processing is developing in the direction of finishing, fast speed, and high surface accuracy. [0003] Among them, the pull rod mechanism, as the core part of the high-speed e...

AI Technical Summary

Problems solved by technology

High-frequency tool change operations directly lead to overloading of elastic elements, which eventually leads to shortened service life and failure

[0007] (2) Insufficient rigidity

Disadvantages of disc springs are: in order to obtain sufficient restoring force, disc springs need to be stacked in multiple groups, and the elastic element used as a pull rod mechanism will cause: 1) increased friction and reduced restoring force of the elastic element; 2) in the electric spindle When the illegal operation of acceleration and deceleration with high acceleration without clamping the tool holder is performed, these illegal operations will cause the disc spring to rotate relative to the outer diameter of the draw bar. Balance position changes

The disadvantages of cylindrical coil springs are: large compression ratio and relatively short life. Therefore, under the same restoring force, the stroke required is longer than that of disc springs. The elastic element used as a pull rod mechanism will eventually lead to too long pull rod length

[0011] In summary, eccentric sticking and increased friction may occur in the working process of the existing elastic elements, resulting in loss of the elastic element’s restoring force, and insufficient clamping force of the electric spindle to clamp the tool handle or collet, which eventually leads to the loss of the electric spindle’s broaching Insufficient rigidity of the system

[0012] (3) Affect dynamic balance

[0013] 1) The deformation of the elastic element under the high-speed centrifugal force causes the center of mass to shift; 2) The ordinary cylindrical coil spring has a rotating force opposite to the helical direction when it is compressed, and the inner diameter and outer diameter become larger at the same time when it is compressed, which affects the balance accuracy of the electric spindle

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