Two-grade buffering and stopping mechanism of free piston

Abstract

The invention provides a two-grade buffering and stopping mechanism of a free piston. The free piston is composed of a rear end cover, a wearing-resisting ring, a piston body, a retainer ring, a sealing ring and a front end cover; acceleration-phase resistance reduction, decelerating-phase resistance increasing and sealing functions of the piston can be realized; the whole body of the piston is of a concave cavity structure; the two-grade buffering and stopping mechanism is composed of a buffering cushion, a supporting ring, a sleeve and a base and is of a convex through structure. In order to realize soft landing requirements of the piston, an annular pneumatic buffering cavity is formed by the sleeve, the base and an inner wall of a compression pipe; when the piston enters, primary buffering can be realized and most of kinetic energy of the piston is absorbed; the buffering cushion forms secondary buffering and the residual kinetic energy of the piston is absorbed through elastic deformation or plastic deformation of a material, so that the soft landing of the piston is realized. According to the two-grade buffering and stopping mechanism provided by the invention, the disadvantages of the type of equipment at present in the world that the elastic buffering cushion is easy to damage, the impact load in equipment is relatively great, the capability of absorbing the kinetic energy of the piston by the buffering piston is limited are overcome.

Description

technical field [0001] The invention relates to the technical field of drive for high-enthalpy shock wave wind tunnels, in particular to the design of a free piston and a buffer stop mechanism in the free piston drive technology. Background technique [0002] The free-piston shock tunnel is a high-enthalpy shock wind tunnel using free-piston drive technology. This type of wind tunnel drives the free piston to isentropically compresses single-atom driving gas through a heavy-piston compressor, and drives the shock tube to run after reaching a high temperature and high pressure state. , after the test gas stagnates at the end of the shock tube, it expands and accelerates through the nozzle to achieve the purpose of high-speed and high-enthalpy flow simulation. [0003] combine figure 1 Describe the movement process of the piston: at the initial moment, the piston starts to accelerate from rest under the action of the pressure difference between the upstream and downstream (up...

AI Technical Summary

Problems solved by technology

[0006] The purpose of the present invention is to overcome the shortcomings of the elastic buffer pads in the current international free piston shock wave tunnel equipment, which are easily damaged, have a large impact load on the equipment, and have limited absorption of piston kinetic energy by the buffer pads.

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