RU1821343C - Method of combination machining shafts - Google Patents

Abstract

SUMMARY OF THE INVENTION: Before processing, the static deflection of the shaft is measured and during processing, a deforming element, for example a roller, is continuously mixed in the direction of the static deflection of the shaft by the amount of this deflection, while the displacement gradually increases to the point of maximum deflection of the shaft, and then decreases. Roller displacement is carried out by kinematically related to its radial movement and rotation in a plane perpendicular to the center line of the machine around an axis that does not coincide with the geometrical axis of the roller. During processing, the roller is additionally continuously rotated by an angle equal to the angle between the center line of the machine and the tangent to the curved axis of the shaft. The rotation of the roller is carried out in a plane parallel to the plane of the static deflection of the shaft, in the direction of alignment of the projections of the axes of the roller and the shaft on this plane. 4 s.p. f-ly. 3 ill.

Description

The invention relates to mechanical engineering and can be used in the paper industry for turning lengthy shafts of various materials.

The aim of the invention is to improve the quality of the machined surface and increase accuracy when machining shafts having a static deflection, the direction of which is maintained during processing.

Fig. T shows a schematic diagram of the processing of the proposed method; Fig. 2 - loading of the shaft and deflection of its axis under the action of its own mass and axial forces; in Fig. 3 - a shaft with a cutter and a roller, a side view in Fig. 1.

The processing according to the proposed method is carried out as follows.

Before processing, the static deflection of the shaft is measured along its length and the cross section is found in which it is maximal. The maximum deflection of the shaft fmax usually lies at half the length of the shaft (figure 2). Then the parts (shaft) 1 are rotated at a speed V, and the combined tool consisting of a cutting element, for example, a cup cutter 2 and a deforming element, for example, a roller 3, mounted in relation to the cutter 2 on the other side relative to the axis 4 of part 1 and at the beginning of processing at the level of the center line 5 of the machine, the feed S is reported. Cutter 2 is installed at an inclinometer and with offset N. The cutter removes an allowance of depth t and the deforming element 3 has the ability to independently control the deformation force Rd. Since the axis 4 of the part and the line of the centers 5 of the machine do not coincide (figure 2), due to the presence

from th

C)

N

with

static deflection fi of the part, then in the process of processing the roller 3, i.e., its axis b, is continuously shifted in the direction of the static deflection of the shaft 1 (in plane 02) (FIG. 3) by the value of this deflection fi. That is, the movement of the deforming (rolling) roller 3 occurs in a plane perpendicular to the feed plane at a speed Sb (Fig. 3). The displacement h of the roller 3 is equal to the static deflection fi of the shaft 1. In this case, to the point Oz of the maximum deflection equal to f max, the displacement of the roller during processing smoothly increases from zero to fmax (normal to x 1/2), and then the displacement smoothly decrease from fmax to zero. Fig. 3 shows the positions of the deforming roll. Ika 3: C- start and end position: roller axis; Cg-position of the axis of the roller /, corresponding to the maximum deflection of the shaft; Ci is an intermediate position. The amount of displacement h. fi of the roller 3 during processing can be determined not only by measuring the value of the static deflection before processing, but theoretically by the following formula:

h fi

 t

where q.

the fact that at each moment of time the axis b of the roller 3 is always at the level of the axis 4 of the shaft 1, which leads to a constant force in the direction of the axis of the op-amp;

The displacement of the deforming roller 3 in the direction of the static deflection of the part 1 can be done by turning it in a plane perpendicular to the line of centers 5 of the flock (in the plane of the drawing of FIG. 3)

around an axis that does not coincide with the geometric axis 6 of the deforming roller 3. The axis of rotation can coincide: with point 0 lying on the line of the centers of the machine 5 (Fig, 3); with Od, lying at the level of the center line of the machine; with point Og lying on the level

lowest point Oz axis of the part; with the point Oz, coinciding with the point of maximum deflection of the axis 4 of the shaft; with any other point, for example, 04. In this case, the rotation of the roller is carried out at the angles a, a, a (x3 x from zero to maximal value of them on the shaft processing length equal to x 0.5 I, and then from the maximum Values are up to 0. In this case, the transverse (radial) movement with the speed of Snori, kinene, is informed to the roller 3, as well as to the related corollary

turning, at a length of x 0.51 in one direction,

and then the opposite. For example, when

turning around an axis passing through KyOi-. we have (fig.Z).

h Room obi roller; D.

- ;: I lane of the shaft; .; V.f-.; G, - .. (: -: V; -v:; l .--; V7ivv;: -: v 4 ;; -. -; ..; x - distance from the shaft end to the current 35th position roller 3; - ..; .V.,..: C, V;; E.- stiffness ;; shaft, .. -: -,. .- v; ...:.;. ..-,: ;: For x 1/2 we have.: .. ..

fmax

384EI

(2)

where E is the modulus of elasticity (for steel E. (2.0-2.1); 10J, kg cm2; i & & $: vx:, - ..:.; Shmo | lö; 1g HBP1D11i / dl shaft. 4 45 .- :. f., - / -; the magnitude of the shift of the flicker can be determined by the equation of the curved axis of the shaft, ntr y axial force

.i in Tisi Nusdidas :; . }. ..

fifty

h;

 v ftX ---- fmax Sin - | - .. (3)

where fmax -. the maximum value of static- ckpro prrbyba; .. shaft; - / :, i, -:;,:,: ....

. G: -; dl called a .; :: ;; :: lg -. ; . ;; .-. v Thus, the playful movement

 the roller in the process and in the; a; the right Static deflection of the part leads

(4)

where P1 01C,

a fi is determined, for example, by the formula (1):

: Sncm Sn

RH -Ri VRl + ff -NG, - r x / Sn -.

(VRi -Mf-Rj),

(5)

where S is the feed roller; .

n is the shaft speed;

fi- current value of the static deflection of the shaft .; -. .; ..: .. V. Since the part retains its static deflection during processing, and the axis 6 of the roller is parallel to the axis 5 of the lines of the Center of the machine and the tangent axis of the shaft 4 makes a certain angle with the line of centers of the machine 5, the axis of the roller and the axis of the part are crossed straight, the angle / between which varies from the maximum value to zero, which is received at the point of maximum deflection of the part. This means that during processing the spot contact of the deformation roller with the part changes, which leads to a change in the specific pressure between them and the mutual deepening. With self-oscillations of the shaft along the OZ axis, this leads to an inhomogeneous quality of the machined surface along the shaft axis. To eliminate this drawback, the axis 6 of the roller 3 is continuously rotated smoothly by an angle equal to the angle between the center line of the machine and the curved axis of the shaft, determined from the ratio:

(6)

where q G / f,

In this case, to the point of maximum deflection of part 1, the angle / Si gradually decreases from the maximum value to zero, and then increase from zero to the maximum value determined from the ratio

fa

GL 24EI

(7)

Moreover, the rotation of the roller 3 is carried out in the XOZ plane of the static deflection of the shaft in the direction of alignment of its axis 6 and the axis of the shaft 4. The angle can be determined, taken from the expression (3). Then we have

fir

f L fmax T COS-g (8)

and Dpah we get at x O

P

Dpah fmax

T

. (9)

where Dpah - The maximum value of the angle of rotation of the roller ;. .

I is the length of the shaft;

fmax - the maximum value of the static deflection of the shaft.

An example implementation of the method,

The shaft is machined with a diameter of D 700 mm and a shaft length of I 8600 mm. Processing mode; feed S 1.0 mm / rev; cutting depth t 0.6 mm; shaft rotation speed n 160 rpm. Shaft weight G 17000 kg; Apri 0.391.10 kg / cm2. Rd Ru 100kg. The diameter of the roller dp is -100 mm. Before processing, we measure the static deflection of the shaft along the length of the treatment and the maximum static deflection fmax 3.0 mm. At the beginning of the processing, the roller axis is set at the level of the center line of the machine. When processing the shaft, the axis of the roller is shifted by the amount of static deflection. To ensure a constant value of the contact of the roller with the part and the force Rp, the roller is smoothly rotated through an angle D. The displacement value h and ft. calculated according to dependences (1.3) and (6.8), for some values of x are given in table 5.

As a result of processing, we obtain: roughness of the processed surface Ra 1.0 mm, accuracy in diameter over the entire length of 0.02 mm. When processing without roller

0 we have Ra 3.0 μm, accuracy 0.15 mm

 (we have barrel-shaped).

The roller in the feed direction can be installed after the cutter, dB cutter or

on the cutting surface.

5 The method provides a reduction in vibration of the shaft in the direction of the axis of the OS, i.e. in the direction radial to the part. This improves the quality of the treated surface by 3 times. Thanks for the video

0 is always at the level of the Axis of the part; we have its constant pressure on the part. This ensures a constant difference in radial forces from the cutter and the roller, which determines the receipt of parts with improved accuracy. Processing accuracy

increases by 5-10 times. The method is simple to implement and allows its use in the processing of long products.

thirty

Claims (5)

1. A method of combined processing of shafts with cutting and deforming elements, in which the shaft is fixed in the center of the machine, the cutter and the deforming element are set on different sides relative to the axis of the shaft and inform them of the feed movement, characterized in that, in order to improve the quality of the machined surface and improve accuracy when processing shafts with a static deflection, the direction of which is maintained during processing, the static deflection of the shaft is preliminarily measured, and during processing, the deforming element is continuously displaced in the direction of the static deflection of the shaft by the value of this deflection, while up to deflection of the displacement shaft gradually increase and then decrease. 2. The method of claim 1, wherein the displacement of the deforming element is carried out by radial movement and rotation in a plane perpendicular to the center line of the machine around an axis offset from the geometric axis deforming element. 3. The method according to p. 1, with the effect of the fact that during processing the deforming element is additionally continuously rotated turn by an angle equal to the angle between the center line of the machine and the curved axis of the shaft, while to the point of maximum deflection of the axis of the shaft, the angle is smoothly reduced from the maximum value to zero, and then increase from-zero to the maximum value determined from the ratio  l, -.; ;: v ... . . . . ..   T - :: where / msx is the maximum angle of rotation of the deforming element; I-shaft length; . . Phys. 1 0 fmax - the maximum value of the static deflection of the shaft, the rotation of the deforming element is carried out in a plane parallel to the plane of the static deflection of the shaft in the direction of alignment of its axis with the axis of the shaft. 4. The method according to claims 143. that a cup tool is used as a cutter. 5. The method according to claims 1 to 3, characterized in that a roller is used as a deforming element. Figure 1 H Fm.5