SU1399085A1 - Method of grinding radial concave surfaces - Google Patents

Abstract

The invention can be used to grind special surfaces mainly from hard-to-machine materials, in particular, roll streams of rolling mills. The aim of the invention is to improve the quality of the surface to be treated by reducing the cutting forces and unit loads on the wheel and the product, as well as improving the grinding performance by reducing idle longitudinal movements of the roll. The formation of the side walls of the radial surface 4 of the stream begins with the alignment of the top 3 of the circle and part 2, then first form one wall of the radial surface, and then the other by mutually perpendicular movements of the part and the circle, and the values of these displacements are chosen from the condition of equality of the central angle of the radial surface formed by a pair of displacements that form a step. 4 il. with (L

Description

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The invention relates to the field of grinding radius surfaces (e.g., grinding rolls of rolling mill rolls).

The purpose of the invention is to improve the accuracy and productivity of processing by reducing cutting forces and unit loads on the wheel and the product and reducing the number of edits of diamond wheels.

Fig. 1 shows a scheme for implementing the method (the position of the hone-field circle after the formation of the vertical); figure 2 is the same, the final position of the circle when processing the right half of the stream; fig.Z - the same, when processing the left half of the stream; figure 4 - sequence nap. The direction and the magnitude of the mutual displacements of the stick and the grinding wheel when performing the method (left) and the direction of movement of the grinding wheel (right).

The method is carried out as follows: 1 ohm.

Choose 1- / t pulley wheel 1, while taking into account the dependence of g R

(0.05 - |)

mm, JT corrected

circle radius g of the working surface. The circle is edited in order to eliminate the beating and obtain the correct geometrically exact radius of the circle.

Then, the rotation of the part is reported to the stream Hojmy) 2 and circle 1 in the pro-M of the opposite directions, then the top 3 and the circle 1 are aligned and the circle is moved in the direction perpendicular to the longitudinal axis of the roll to the top 3 of the roll stream with the formation of the top. After that, firstly, one wall of the radius surface is formed by the roll roll 2, and the second one is formed by alternating the relative stepped movements of the roll and the circle in two mutually perpendicular directions.

During the formation of each side wall paj HycHofi of the surface 4, the stream first rolls (retracts) the circle from the top of the stream in the direction perpendicular to the roll axis by the amount of LTP, and then the roll 2 is moved along its longitudinal axis 00 by the value & 5 brook Two such mutually perpendicular ph, gx displaceable form a step, and a chunkt, a bokpey on top

The creek, bounded by one step, forms a central angle.

Each longitudinal movement of the roll alternates with transverse movements of the circle, i.e. perform stepwise movements in mutually perpendicular directions from the top of the stream to its release 5,

The magnitude of the longitudinal displacements (working feeds) in each subsequent stage is reduced from 1 to d1, and the magnitude of the transverse displacements (elbows) is increased in inverse dependence on & in, before & t.

Thus, dt, crash. ... L1 „Dt ,, i.e. magnitudes

0

0

five

P-1) 1

mutually perpendicular longitudinal and transverse displacements are inversely related.

A series of longitudinal displacements with an equal number of transverse displacements (taps) form one of the side walls of the radius surface 5 of the stream. In order to form another wall of the radius surface, a roll or circle is first moved along the longitudinal axis of the roll by the value of Rr in the direction of the middle of the stream, then transversely moves in the direction of the top of the stream (perpendicular to the axis of the roll) by the value (Rr) -tn (Fig .four). Then form the second side wall of the radius surface of the stream similar to the formation of the first side wall, maintaining the sequence and magnitude of displacements, but the direction of the longitudinal displacements (working feeds) is reversed.

The beginning of the formation of the apex of the radial | surface of the part and the subsequent stepped fop fflrovanie first one and then the other side wall of the radius surface allows to fix the initial position of the grinding wheel and the part by aligning the top of the stream with the top of the circle.

Grinding each of the side walls of the radius of the part reduces cutting forces and the specific load on the wheel. This is especially important when grinding parts from hard-to-machine materials (for example, hard splices using diamond grinding wheels, when machining with increasing cutting forces and fiarpyioK, Foie defects on the radius surface can be formed

five

0

five

these parts and the grinding wheel and the form of chips, microcracks, pressure on the radial surface flew, as well as cutting out and digging on the surface of the circle).

The magnitude of the mutually perpendicular relative displacements of the part and the circle is selected from the condition of equality of the central angle of the radius surface formed by the pair of displacements, forming a 1x1x step and ensuring a radius surface that has the correct semicircle in cross section.

The magnitude of the longitudinal displacements (working feeds) alternating with the transverse displacements (taps) of the wheel and roll relative to each other of the rod is determined from the condition of obtaining the correct semi-circle when grinding the surface of the strand. LL of this alternating movement of the roll and the circle must occur,. and n; the case of a rho semi circle whose radius is equal to 1e (rr) mm. In our case, this trajectory is a stepped line and is gzameno perpendicular segments (figure 4). Each of the points of intersection of steps of a step lies on the arc of a semicircle whose radius is equal to (R-r) mm.

A smooth, geometrically accurate BepxFiocTb roll roll is formed by the formation of mutually overlapping areas (grinding touch) when grinding. This is achieved on condition that the number of mutual displacements is correctly chosen (practically chosen in the range from 6 to 20). This dependence is determined from the condition that the more R

the stream and the smaller (r-r), the number of reciprocal movements and vice versa.

Example. For grinding, a cylindrical roller was taken, on the outer cylinder of which there was a closed radius stream with a concave surface. The height of the processed pv (must have a papHoi i of its radius K, i.e. R - 10 mm. Grinding with a special diamond cool with a radius convex noBepxHi gr on nickel galvanic Pskov ich lev diamond of 125/100 diameters. Circle size 250 H . Processing conducted on a grinding machine,

providing longitudinal and transverse micro-feeds.

Processing mode: 25 m / s,

shaft rpm

The speed of movement (working feed) of the circle in the direction perpendicular to the axis of the roll S is 0.3 mm / min. The number of movements of the roll and the circle taken n 10.

Calculate the magnitude of the longitudinal

move) 1st D 1 w.pka in each step from the condition of equality of the central angle oi. the radius of the surface of the stream, which is determined from the mathematical expression

1 (2К-1) Ы. D1,, about 2 (R-r) sin-COS -2

  90 90 o, de ---. --- 9 .

Putting in this expression R 10, g 8 and K, equal to the sequence number of the roll movement, we get:

°. Сoy4,5 ° 4 с о G 1 3,5 с о S 2 2, 5 .cos 31, 5 ° - .cos40,5 ° - 4 cos49,5 - cos58,5 cos67,5 cos7ft, 5

, 5 ros85,5

0.0785-0.9969 0.3130266 0.313; 4-0.0785-0.9724 0.3053336 0.305; 4-0.0785.0.9239 0.2931046 0.290; , - (), 0785-0.8526 0.267764 0.268; 0.0785-0.7604, 0.2387656 - 0.239; 4-0.0785-0.6494 0.2039116 0.204; 4-0.0785-0.5225 0.164065 0.164; 4-0.0785-0.3827 0.1201678 0.120; A.0.0785-0.2334 0.073287b 0.073;

0.0785-0.0785 0.024649 0.025,

Circle (); n, pig |) vally machine tools soil, 1 - mt rlbpttatt, with accuracy} AND - fi -cc 1 mic, therefore / -h (1--1 degrees D district-ks m--, lu 3- go

55

Since the velt of the transverse displacements (elbows) of the circle is in reverse: h1st1mg1sti from the value of the long displacement stick,

t-, l14 0,268 mm j

mg W, 0.290 mm;

t, ulj 0,305 MM;

m, 0 d1, 0.313 mm.

The rotation of the grinding wheel and the beam was carried out in the opposite direction: directions. Then the lg was moved in the direction perpendicular to the p-longitudinal axis of the roll, and the piping was removed from the top of the stream in one pass; . After that, the grinding wheel was retracted by the value of m 0.025 mm and the roll was moved along the longitudinal axis by the value of A1, 0.313 mm. During this movement, a section of the stream surface is formed, which is adjacent to the bridge.

Then pg produced a circle retraction by the value of m ,, 0.073 mm and another longitudinal roll offset by the value of А ,, 0.305 mm, during which jjoro the next section of the lateral surface of the stream was formed. Thus, a series of relative stepwise displacements of the roll and the circle in ;; two mutually perpendicular surfaces: the formation of a stream formed from 1 LOVE was made.

After the end of the formation of one IO.TTOWNS of the lateral surface of the stream, the roller of its longitudinal axis was moved with the change of nranrantgeni to the opposite one by the value of R-r 10-8 2 mm

13990856

Then the circle was moved to the top of the stream in the direction perpendicular to the longitudinal axis of the roll, by a value of (R-r) - m, 2 mm - 0.025 mm - - 1.976 mm and produced a longitudinal movement of the roll by the value L1, 0.313 mm.

After that, alternation of the circle outlets and longitudinal movements of the roll 11 was carried out in the same way as when forming the first lateral surface of the stream. Dimensions L1 and Lga are the same as in the processing of the first half of the stream. 15 The following results were obtained:

Roughness Ra 0,63 micron. Profile accuracy corresponds to drawing specification 20. Processing time 20 min.

Claims (1)

Invention Formula The method of grinding the radial concave surfaces of the parts, in which dt, etali and a circle with the radius of the working surface is smaller than the radius of the concave surface of the part, rotation and relative stepped are reported 30 displacements in d, in mutually perpendicular directions, which are related to the fact that, in order to improve the accuracy and productivity of processing, the relative displacements of the part Zy and the circle are made from the top of the radius surface alternately to both sides, and the values of mutually perpendicular displacements of the part and the circle in each step are selected from the condition of the central angles of the radius surface of the part formed by the pair of displacements forming the step.