SU1284718A1 - Boring mandrel - Google Patents

Abstract

The invention relates to metal cutting and can be used for machining holes. In order to increase the vibration resistance of the system due to the dissipation of the oscillation energy, the mandrel is equipped with an additional dynamic vibration damper consisting of balls 10 placed in an opening 8 made in the body of the cutting head. Vibration dampers 9 and 10 differ in number and diameter and are also balancers of the housing 1 and the head 2. The tool is mounted on the cutting head 2 with a threaded shank, while the cutting head 2 is installed in the eccentric threaded hole of the housing 1, which allows the cutting head to rotate and adjust its axial and radial departures. The measurement of the adjustment value is carried out on a scale 14 with a variable division price. 1 il. (L

Description

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The invention relates to machining, metal cutting and can be used for machining holes.

The aim of the invention is to increase the vibration resistance of the system by dissipating the oscillation energy of the process system between the two vibration absorbers.

The drawing shows a boring bar.

The mandrel consists of a housing 1 with an installation cone and a cutting head 2 containing a combined Drill 3 and a boring countersink 4. The eccentric threaded hole is made in the mandrel body 1, and an eccentric threaded rod on the holder of the cutting head 2, and the Eccentricity e-hole and the stem are the same . To fasten the cutting head 2 with the body 1, flats 5 are provided on the holder, and for fixing the screwed position - fixed screws 6. From the end of the eccentric surface of the body 1 and the cutting head 2 holders are pro-drilled in the axial direction of the hole 7 with a larger diameter and a smaller i depth in housing 1 and. holes 8 less diameter and greater depth in the upper head 2. In these holes: hardened balls are installed from steel 9 of larger diameter and ball 10 of smaller diameter, respectively. -The holes are closed with threaded plugs. Hardened balls with compacted structure due to heat treatment are shock absorbers of shock effect of both the body and the cutting head. Because of the difference in the diameters of the balls and their number in the housing 1 and in the real head 2, there is a difference between the weights, which makes it possible to

f5

20

25

thirty

35

40

3. In the state of the threaded tails of the drill 3 is fixed 13, as a result of the turning of the cutting head 2, the centering e is conducted and, therefore, the radius of departure can vary from 0 to 2, the eccentre value is determined and, therefore, radially provided a scale of 14 with a division of the periphery 1 and an elastic pointer 15, n onto the threaded rod of the holding head. The elastic pointer is constantly in contact with w when changing the eccentricity by rotating the turning heads of the desired position, the elastic 15 is fixed by means of vi. The change in the radius of the boring 4 is made by changing baking in the direction due to the rotation of the head 2 on the thread. When holding the cutting head 2, the countersink 4 is axially changed by the spacing of the joint without changing the radially offset. The elastic pointer 15 can be screwed along the thread of the holding head 2 in the opposite direction.

Boring bar in a working manner.

If the value of ektet is zero, i.e. when the cutter head 2 coincides and in solid material, drill the hole and then bore it. When changing

risit up to 2e, t

reliable dissipation of the oscillation energy .. turning the cutting head 2

the technological system and the avoidance of hitting the resonance frequency of oscillations when the position of the cutting head 2 changes in the radial and axial directions. On the side of the end of the holder of the cutting head 2 coaxially with the cone of the body 1, in the screwed position, a left-handed thread is cut for unscrewing the right-hand drill bit. 3, for which it is made on the threaded shank 11. Ways 12. At the end of the cutting head 2 there is a neck, on which the boring countersink 4 is mounted, and is fixed on it when screwing the combi

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the largest radius 4 occurs in the radial direction of the next bore drill 3 passes into the preliminary hole. Since the top of head 2 can be changed and the direction of unscrewing e of start 1, this provides the possibility of processing steps in solid material, it is possible to simultaneously drill holes, producing outreach dimensions in radial axial directions.

0

five

0

five

0

five

0

The drilled bit 3. In the screwed state of the threaded shank 11 of the drill 3 is fixed by the set screw 13. As a result of turning the thread of the cutting head 2, the eccentricity value e and, therefore, the radius of the countersink 4 can change from 0 to 2 e. To determine the magnitude of the eccentricity and, therefore, radial overhang, a scale 14 is provided with a variable division price at the periphery of the housing 1 and an elastic pointer 15 screwed onto the threaded rod of the cutting head. The elastic pointer 15 is constantly in contact with the scale 14 when the eccentricity is changed by turning the descending head 2. In the desired position, the elastic pointer 15 is fixed by means of a screw 16. The radial direction of the offset of the boring core 4 in the radial direction is accompanied by a change in baking in the axial direction due to turning the cutting head 2 on the thread. When the holder of the cutting head 2 is rotated by 360, the countersink 4 is inserted in the axial direction changes by the pitch of the threaded connection without changing the amount of outflow in the radial direction. In this case, the elastic pointer 15 can be screwed along the threads of the holder of the re-swiveling head 2 in the opposite direction.

Boring bar works as follows.

With a zero value of eccentricity, i.e. when the axes of the holder of the cutting head 2 and the housing 1 coincide, solid material is produced - a hole is drilled and a subsequent boring is made. When changing the eccentric value of 2e, t, e,

cutting head 2

on

at 360 °

0

five

there is the largest radius of countersink 4 in the radial direction. During the subsequent boring, the drill bit 3 freely passes into the previously made hole. Since the cutting head 2 can be changed in the axial direction by unscrewing it from the housing 1, this makes it possible to process the stepped holes in the solid material, i.e., it is possible to simultaneously drill and bore the holes, adjusting the outreach dimensions in the radial and axial directions. x

1284718

Vibration dampers made in the form of spherical bodies of increased density of various reduced masses, mounted in both eccentrically made elements of the mandrel, 5 operate according to the principle of percussion action. They produce vibration damping by dissipating energy at the points where two bodies collide, while ensuring the vibration resistance of the cutting process. The difference between the reduced masses of vibration damping elements creates conditions that exclude the occurrence of a resonant frequency of oscillations in the AIDS system.

The reduced masses of the vibration-damping 15 elements are chosen in proportion to the masses that determine the imbalance of the housing 1 and the cutting head 2 of the boring bar. Vibration absorbers: with different reduced masses of 20 percussive action, dissipating the energy of oscillations, do not allow the establishment of an equilibrium of damping and exciting forces and the occurrence of self-assembly of difficult-to-work materials, such as stainless steels and heat-resistant steels. The proposed mandrel can be used to form holes in a wide range of diameters on various machines, including aggregate ones. The adjustment of the cutting head in both the radial and axial directions is carried out in a wide range with high accuracy and differs simply by that.

Claims (1)

Invention Formula A boring mandrel containing a housing with a dynamically placed vibration damper, a balance bar and a cutting head mounted with the possibility of changing the radial overhang with respect to the axis of the housing, which, in order to increase the vibration resistance of the system, is equipped with an additional dynamic - --- - ..-., ipaizyna additional dynamically vibrating oscillations or self-oscillator-25 with a vibration damper installed in the rake. Improving the dynamic properties of the proposed mandrel through the use of vibration dampers allows the processing of parts of low rigidity with a use that is made in the body of the cutting head, and the vibration dampers are sets of balls that differ in number and diameter  , .Ии 1лч-л 4irjLv-jnji i j-i dl11ms1uim, iriche the tooling is also low — 30 sets of balls of smaller diameter and stiffness, especially when removing thin chips, get rid of vibrations. This is especially important when machining parts. a larger number is installed in the head, and a set of balls of larger diameter and a smaller number - in the body. 1284718 from difficult-to-work materials, for example, from stainless steels and heat-resistant steels. The proposed mandrel can be used to form holes in a wider range of diameters on various machines, including aggregate ones. The adjustment of the cutting head in both the radial and axial directions is carried out in a wide range with high accuracy and is distinguished by simplicity. Invention Formula The boring mandrel, comprising a housing with a dynamic vibration damper, a balance bar and a cutting head, installed with the possibility of changing the radial overhang with respect to the axis of the housing, characterized in that, in order to increase the vibration resistance of the system, it is equipped with an additional dynamic ipaizyna extra dynamically a vibration damper mounted in a hole, which is made in the body of the cutting head, and vibration dampers are sets of balls of different numbers and diameters, moreover , .Ии 1лч-л 4irjLv-jnji i j-i dl11ms1uim, iriche set of balls of smaller diameter and set of balls of smaller diameter and a larger number is installed in the head, and a set of balls of larger diameter and a smaller number - in the body. / / / 6 71ЧЕ U8 3 12