SU1763747A1 - Vibration damper - Google Patents

Abstract

Vibration damper. Use: mechanical engineering, in particular, to damp oscillations of machine tool parts. SUMMARY OF THE INVENTION: A vibration damper mounted in an axial bore of a boring bar body comprises a cylindrical hollow insert fixed with a radial clearance mounted in the boring bar body. The discs are installed in the insert cavity. The cavity formed by the reversed surfaces of the housing of the boring bar, the cylindrical insert and the seal is filled with a working medium. 1 hp f-ly, 2 ill.

Description

The invention relates to the field of mechanical engineering and can be used to dampen vibrations of machine parts, in particular rotating shafts, and, when processing metals, to eliminate tool vibrations, such as boring bars with a bit.

A vibration damper is known that is inserted into an axial opening of the tool and is a set of disks separated by spacers and compressed axially with spring 1J. To increase the efficiency of shock damping on the discs, annular protrusions 2 are made in the middle part of the cylindrical surface. Vibration dampers suppress the transverse oscillations of the rotating tool. The capabilities of the vibration dampers depend on the radial clearance between the discs and the boring bar, therefore the disadvantage of the known constructions is the absence of a device regulating this gap. In addition, the effectiveness of shock damping oscillations is insufficient

shock elements are not used with high elastic properties.

1 shows a boring bar with a vibration damper placed in it: FIG. 2 shows a section A-A in FIG. L.

Boring bar 1 with cutter 2 is mounted on the spindle of the machine (Figures 1 and 2). The vibration damper is located in the axial hole of the boring bar 1 and consists of a set of disks 3 with annular projections A separated by gaskets 5. A cylindrical insert 6 is placed between the disks and the boring bar, which is attached to the thread or by means of a fit at the blind end of the hole, and with seals and 8 forms a closed cavity containing the working medium. The disks 3 are pressed against the gaskets 5 by means of a device consisting of a spring 9, a pusher 10, a nut 11 and a lock nut 12. A threaded cap 13 closes the opening for the vibration damper in the boring bar and iksiruets via locknut 14.

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The vibration absorber works as follows.

With radial oscillations of the boring bar 1, oscillations of the disks 3, which move towards the boring bar 1, are excited, hit the insert 6, which instantly transmits this action to the boring bar. The material of the insert b and protrusions 4 must have high elastic properties. Steel, flexible plastic like fiberglass, etc. can be used as such material. Selecting the material and dimensions of the protrusions 4, inserts 6, the gaps between the discs 3 and the insert 6, the masses of the discs 3, the pressing force against the spring 9 is debugged by a vibration damper to suppress vibrations of the boring bars.

Since the amplitudes of oscillations of the boring bar cross-sections are different, the masses of the disks 3 and the gaps must be different. Therefore, the insert 6 can be made with a stepped section, providing for each disc 3 its own gap. In addition, with several harmonics in the spectrum of forces acting on boring bar 1, each disk is adjusted to a certain oscillation frequency.

When debugging the assembled damper, the clearance necessary for optimal oncoming movement of the discs 3 and boring bar 1 with its radial oscillations is set using the cap 13 and lock nuts 14. Screw the cap 13, pressing onto the working medium B, under pressure of which the insert 6 is compressed and the radial clearance between the discs 3 and the insert 6 is reduced. The lock nut 14 fixes the position of the cover 13. To improve the deformability of the insert b, grooves or folds can be provided on it depending on the material of the insert 6.

Seals 7 and 8 allow the working medium B to be held at an increased pressure in the cavity bounded by the inner surface of the border 1, the outer surface of the insert b and seals 7 and 8.

The clamping device, placed in the nut 11, allows using the pusher 10 and the spring 9 to regulate the frictional forces at the ends of the discs and to debug the vibration damper. Lock nut 12 is designed to secure nut 11 in an optimal position.

The vibration damper can be debugged on a bench on which vibrations of boring bar 1 can be measured, or on the bore holes. The optimum gap and the position of the nut 11 corresponds to the minimum intensity of oscillation of the cutter 2 and the best quality of the waste surface.

The technical solution will allow to increase the operating efficiency of the vibration damper during micro oscillations.

Claims (2)

1. Vibration damper mounted in the axial bore of the boring bar body, consisting of a set of disks with annular projections, a pressure device and a cover, characterized in that. In order to increase the efficiency of micro-oscillations, it is provided with a cylindrical hollow insert, installed with a radial clearance and a boring bar fixed in the housing, seals mounted respectively at the ends of the cylindrical insert and the lid; the insert is made of an elastic material, and the cavity formed by the reversed surfaces of the boring bar body, the cylindrical insert and the seals is filled with a working medium. 2. The vibration damper according to claim 1, wherein the cavity of the cylindrical insert is stepped. iO Fig /