SU1235641A1 - Method of producing articles with closed cavity - Google Patents

Description

"

The invention relates to mechanical engineering technology and may find application in the foundry industry in the manufacture of, for example, spin ellipsoids.

The purpose of the invention is to obtain a working surface in the form of an ellipsoid of rotation.

FIG. 1 shows a device for carrying out the proposed method; in fig. 2 is a plot of forces acting in the plane of the semiaxes a and from the ellipsoid; FIG. 3 - diagram of the forces acting in the plane of the semiaxes Q and L of the ellipsoid; in fig. 4 - the product obtained according to the proposed method, a longitudinal section.

The method is carried out using a device consisting of a container 1 mounted on a shaft 2, an actuator 3 mounted on a swing frame 4 mounted on a shaft 5 secured by means of a spring 6 with a turntable frame 7 fixed on a shaft 8 connected by a spring 9 with the base 10 and necyn iM lever 11, which interacts with the driving profile cam 12, the actuators 3, the springs 6 and the unbalances 13 with the gears are made paired to balance the rotating units of the device. In necessary cases, the device is supplied with an electromagnetic device 14 for the induction of an electromagnetic field running upwards.

Fluid mass (molding mixture, liquid metal, molten glass mass, etc., depending on the purpose of the product) in a specified amount is loaded into container 1, which is driven into rotation at an angular velocity by means of actuator 3.

At the same time, the unbalances 13, receiving movement from the gear wheel 15 and the gear train 16, also perform a rotational movement, developing each centrifugal force. Since the unbalances on each side of the frame 4 are set in pairs and rotate in opposite directions in the same phase, the components of the centrifugal forces of the unbalances, directed along the line connecting their centers of rotation, mutually balance, and the directed perpendicular to it, harmonically varying

356412

with a circular frequency equal to the angular velocity of the respective rotation of the container (with the gear ratio from the gear wheel 15 to the shaft of the debalance equal to the barrel). The required phase shift of this resultant is realized by initially setting the unbalance in the desired position. Equivalent 1st centrifugal force of both

10 pairs of unbalances about the axis of the shaft 5 create a moment varying according to the same harmonic law. By virtue of this, turning the frame 4 with elastic connections in the form of a spring 6 performs forced rotational oscillations with the same circular frequency and phase shift. Simultaneously, the profile cam 12 is set in motion, interacting with which, lever 1 1

20 with a return spring 9 drives the shaft 8 with a pivoting frame 7. The particles of the fluid mass rotating with the container are subject to centrifugal forces proportional to the square of the angular velocity of the rotational motion around the axis and the distance that the particle is currently axis of rotation (radius of rotation). Centrifugal plots

The 30 forces acting on the particles of the fluid mass are shown in FIG. 2 and 3. When eliminating (or compensating) the effect on particles of gravity under the influence of forces, the distribution of which is still jj on the plots (Fig. 2 and 3), the free surface of the liquid (fluid mass) is the surface of the ellipsoid. This conclusion follows from the established fact that the direction

40 of the resultant force acting on the particle and the direction of the tangent to the surface of the ellipsoid (Fig. 2 and 3).

Consider the ellipses obtained 45 in the longitudinal sections of the ellipsoid. Mathematically, ellipses are described by the equations

50

x; y

where X, y, are the coordinates of the points of the ellipse, measured in the direction of the coordinates D: axes, 55 l, b, c are the elliptical semiaxes.

t cJ Z Then the modules of the derivatives ---,

Jx fJx respectively equal to the modulus tangen3

ca angle IC and angle Y, the slope of the tangent to the surface of the ellipse to this point are equal to

, m - V -

% Y:; 5, tg 1 - - 7

v 1 9G pt

V a & 7 7. a

Centrifugal forces acting

(g)

on a particle of fluid mass at the considered point are equal

G .х (iJ,); C - rr {) + uJ. );

C - tg (-J, v) (J)

where Gj, Su and centrifugal forces acting along the coordinate axes l, y and 2.

f - particle mass, uJ, ijJy. g is the angular velocity of rotation of the container around the x, y, and z axes.

Based on expressions (3) in the absence of gravity, the tangents to the slope of the tangent are determined by the expressions

, / v - - X

 - T --- G .--, g

X x

.

2 C.

uJ

-J.

(M

Equation of vfazheny (2) and (4),

X cjJy oJ

X with

H z

g a

.1

XtAjy - Z.

 L

V5)

from where

i L19 (

b uJy -t-oJ ,, -V uJ

a J / a,. „

(6)

This result suggests that to obtain an ellipsoid, there should be no effect of gravity on the fluid mass, as well as the ratio of the sum of squares of angular velocities of the container around the semi-axes of the ellipsoid cross section to the sum of squares of the angular velocities of rotation around the longitudinal and one of the transverse axes The ratio of the square of the second of the transverse: semiaxes to the square of the longitudinal semiaxis of the ellipsoid.

The ellipsoid of rotation is obtained only when the angular velocities of rotation around the transverse semiaxes {c b and LJ-LJ) are equal.

356414

The choice of a specific rotational speed, temperature, mass, and other indicators of the technological regime depends on the physicochemical properties of the materials used (ferrous and non-ferrous metals, glass, molding materials, etc.). For example, when casting from metal alloys, known recommendations can be adopted for greater rotational speed of the container 10 and the rotational speed can be determined by the formula:

 5520 / -fp g

(7) where 5520 is a constant for all alloys,

t5 P is the density of the liquid metal, the internal radius of the casting. Example 1. It is required to make an elliptical cavity product with semi-axes about 10 cm, 20 8 8 cm, with b (ellipsoid of rotation) made of cast iron.

The specified amount of liquid iron is placed in a container suitable for. Under weightless conditions, the container is told to rotate around the 25th semi-axis a at a speed of 654 rpm, and around the semi-axes b and c - at a speed of 450 rpm. The velocities are calculated by forgulam (7) and (6).

After the product hardens, the rotation around all three semi-axes is stopped and the resulting product is removed from the container.

Example 2. Under the same conditions, it is required to make an ellipsoid c, semiaxes a 10 cm, 8 cm, c 7 cm. In this case, the speeds of rotation around the semi-axes are respectively 654 rpm, 493 rpm, 294 rpm . If a and b are given, then Q value c cannot be arbitrary, the smallest value c is determined from the expression

with,

ib / jq b

C8)

At c s, the rotation speed of the container around the smallest semi-axis is zero.

uJ Oh, (9)

For electrically conductive materials, the effect of gravity on the fluid mass can be compensated for by the action of an electromagnetic field traveling upward.

It is for these cases that an electromagnetic installation 16 is provided (Fig. 1).

However, the implementation of the method gives the most qualitative results.

in conditions of weightlessness on spacecraft and orbital stations, which can be used in the manufacture of ellipsoids of rotation for optical devices.

The rotation of the fluid mass container continues until it is completely cured. In a flat ellipsoid, the ratio of semiaxes corresponds to the ratio of the angular velocities with which the container was rotated around mutually perpendicular axes OX V7,

-

The product obtained (FIG. 4), after being separated into parts, can be used as a stand-alone product (for example, as light reflectors) or serve as a mold for making counter-pieces.

The implementation of the invention will expand the possibilities of manufacturing products with a closed cavity, for example, it will allow to obtain ellipsoids of rotation and triaxial ellipsoids that are used in optical technology.

/ 77ZU)

2

tui,

mxu) :,

FIG.

FIG.

Editor O. Bugir

Compiled by V.Verbitsky

Tehred O. Gortvay Proofreader M. Demchik

Order 3043/10

Circulation 757 Subscription

VNIIPI USSR State Committee

for inventions and discoveries 113035, Moscow, F - 35, Raushsk nab., 4/5

Production and printing company, Uzhgorod, Projecto st., 4

Claims (1)

METHOD FOR PRODUCING PRODUCTS WITH A CLOSED CAVITY by forming them from a fluid mass in a rotating container, characterized in that, in order to obtain a working surface in the form of an ellipsoid of revolution, the container with a fluid mass is rotated until it cures around three mutually perpendicular axes with angular speeds, determined at given ratios of the semi-axes of the ellipsoids by the formulas% _a ^{2 ;} g 's ² ' a ¹⁺ ^ ₇ * ' V T - St XT. where o is the semimajor axis of the ellipsoid, B is the mean semiaxis of the ellipsoid, c is the minor semiaxis of the ellipsoid, χ, ν z are the rotation axes coinciding with the semiaxes <l, b, c, respectively, uJ, ^s 0,>0,> 0 are the angular velocities of rotation of the container around the corresponding axes x , y and 2-. V 123