Chatter-suppressing ruling method based on double-layer elastic support

Abstract

A cross-hinge spring is the preferred support for a ruling tool because of its excellent flexibility. However, there are high precision requirements for the tool installation, which make the installation and adjustments difficult. There also is poor robustness against interference, which readily results in tool chatter. These issues affect the quality of the grating. This paper proposes an elastic ruling tool carrier with a double-layer parallel-spring mechanism, establishes a torque model of the spring, and analyzes its force state. In a simulation, the spring deformation and frequency modes of the two ruling tool carriers are compared and the overhang length of the parallel-spring mechanism is optimized. In addition, the performance of the optimized ruling tool carrier is analyzed in a grating ruling experiment to verify the carrier’s effectiveness. The results show that compared to the cross-hinge elastic support, the deformation of the parallel-spring mechanism by a ruling force in the X direction is on the same order of magnitude. However, the deformation in the Y direction is reduced by a factor of 270, and the deformation in the Z direction is reduced by a factor of 32. The torque of the proposed tool carrier is slightly higher (12.8%) in the Z direction but lower by a factor of 2.5 in the X direction and by a factor of 60 in the Y direction. The overall stiffness of the proposed tool carrier is improved and the first-order frequency of the proposed structure is higher by a factor of 2.8. The proposed tool carrier thus better suppresses chatter, effectively reducing the effect of the ruling tool installation error on the grating quality. The flutter suppression ruling method can provide a technical basis for further research on high-precision grating ruling manufacturing technology.