SU1615081A1 - Method of moving cargo on platform - Google Patents

Abstract

The invention relates to construction, in particular, to methods for the movement of loads for which the effect of dynamic (shock) loads is permissible. The purpose of the invention is to reduce the cost of movement. The method of moving goods is carried out without the use of lifting means using a turntable 2, on which the load 1 is placed, by applying force to this platform to rotate the load in a vertical plane with subsequent lowering (falling) it onto the supporting surface 4. New in the proposed method is The fact that this lowering is carried out as a free fall with a turn around the edge of the turntable. After a fall, the load slides on the platform on the supporting surface due to the inertia of the rectilinear motion, and the angle to which the load is deflected to move depends on the coefficient of sliding friction between the platform and the supporting surface. 5 il.

Description

FIG.

The invention relates to the field of construction, in particular, to methods of moving loads for which the effect of dynamic (shock) loads is permissible.

The purpose of the invention is to reduce the cost of movement.

FIG. 1 shows a diagram of the movement of cargo mounted and fixed on a turntable; in fig. 2 is a diagram in a position prepared for the process of displacement (in a state of unstable equilibrium); in fig. 3 is a diagram in an intermediate position with a free fall with the rotation of the load around the lower edge of the platform; in fig. 4 - scheme

at the completion of the process of falling and, in conjunction where l / c-ta, with the supporting surface; in fig. 5 - the relationship between the friction coefficient frp and the angle a of rotation of the whole structure.

Movable load 1 is pre-installed on the turntable 2 20 with its support through the lower edge 3 of platform 2 on the supporting surface 4 and attached to it by any known method that prevents its displacement. The installation is carried out, for example, by lifting g with the help of jacks and leading platform 2 under load 1 or in any other way. After that, the tangent means 5 is converted by the rotation method around the lower edge 3 to platform 2 with a load 1 into sexual weight P and support reaction (edge 3) at point A — the force NI:

where m is the mass of the load;

g - free fall acceleration.

At the second stage (Fig. 3), the load 1 rotates around the edge 3 under the action of a force T, tangent to a circle with a center at point A and a radius, with

7 Psma; yV2 5-yVu or

N2 Pcosa.-Nu mgCGsa: -man, (1)

centrifugal force when moving in a circle; L 2 is the reaction of rod AB from the action of rib 3 at point A;

V / 2.

a „centrifugal acceleration, in

where KT is the instantaneous linear velocity, directed tangentially to the circle, coinciding in direction with the force T (conventionally not shown).

To determine the velocity V-, use the law of conservation of energy, i.e., that the change of potential energy is equal to the change of energy kinetic in absolute stable stability, when the 30 - th L RGP. ™

that when the load 1 is rotated until the lower surface of the turntable 2 is in contact with the supporting surface 4, this platform remains stationary relative to the surface 4, i.e. it is not a percentage of the weight of the load 1 and the edge 3 is located in the same vertical plane. Then the connection between pulling means 5 and platform 2 is disconnected and the load 1

on platform 2 gets the chance svo-,

bouncing with a turn around the reb-35 s, is applied to the supporting surface 4. pa 3 at an angle a before contact with the supports — Thus

surface 4, on which platform 2 is installed. At the same time, npvi is a sufficient angle of rotation of the load 1 under the action of inertia of a linear motion;

and AKchlii1 - (2) where - the initial potential

the inertia of irnmlineini d, pn energy,

performs horizontal displacement (skid- 0 U mgRcosa. - final potential) together with platform 2 on surface-energy;

4. After stopping the cargo, the operation is repeated until it is fully moved to the required distance. R,,, , ",,,.

unstable equilibrium O, then VfK - - is the initial energy.

potential

Example. Cargo 1 is represented by a body of mass m concentrated in the center of the body. The load 1 is incompressible, the DZP, BC rods are rigid and have no mass, and the projection of the rib 3 is located at point A. The contact of the load 1 through the platform 50 9 with the supporting surface 4 occurs when the triangle ABC rotates through an angle (t YOU (the angle between the bottom surface of the turntable 2 and the support surface 4).

When the load is rotated at the first stage (Fig 2), the load 1 is in the unstable equilibrium position (the upper position of the center of gravity) under the action of self-clamping (2) looks like this:

or

mgR-mgRcosa. (l-cosa),

then

(l-cosa)

(3)

After substitution

(3cosa-2) (4)

55 The horizontal component of the force N2 (N2sina) is trying to move platform 2, and the friction force of fTp.i N2Cosa, prevents it, therefore, exclude

the actual weight P and the support reaction (the edges at point A are the force NI:

where m is the mass of the load;

g - free fall acceleration.

 by this

 where l / c-ta

At the second stage (Fig. 3), the load 1 rotates around the edge 3 under the action of a force T, tangent to a circle with a center at point A and a radius, with

7 Psma; yV2 5-yVu or

N2 Pcosa.-Nu mgCGsa: -man, (1)

centrifugal force when moving in a circle; L 2 is the reaction of rod AB from the action of rib 3 at point A;

V / 2.

a „centrifugal acceleration, in

where KT is the instantaneous linear velocity, directed tangentially to the circle, coinciding in direction with the force T (conventionally not shown).

To determine the velocity V-, use the law of conservation of energy, i.e., that the change of potential energy is equal to the change of energy kinetic in the absolute L RGP. ™,

- L RGP. ™,

that when the load 1 is rotated until the lower surface of the turntable 2 is in contact with the supporting surface 4, this platform remains stationary relative to the surface 4, i.e. it is not pro,

It is applied to the supporting surface 4. Thus

finite potential energy;

 R,,, , ",,,.

initial energy

potential

life unstable equals

Life (2) looks like this:

or

mgR-mgRcosa. (l-cosa),

then

(l-cosa)

(3)

50

After substitution

(3cosa-2) (4)

55 The horizontal component of the force N2 (N2sina) is trying to move platform 2, and the friction force of fTp.i N2Cosa, prevents it, therefore, exclude

slippage, inequality must be observed (Dr is the coefficient of friction sliding between turntable 2 and bearing surface 4)

N2sinal.N2COsa | f or

i .e. a, arctg | v.

Therefore, with a.max arctg | p to prevent the platform 2 from slipping to the left in

2mg (l -cosa.) Sina + mgsinacosa h fng-2mg (-cosa) cosct- -mgsin-a .. Hence, after transformations, taking into account the equality sin a + cos a l, the expression

fsina {2-cosa.)

 2 (1-co5a) + sor

(7)

Thus, the specific coefficient of friction slip / tr between the reference

In the process of rotation of the load 1 around the edge of the plate-U surface 4 and platform 2, from expression 2 it is necessary to limit the possibility of such movement, for example, by placing an emphasis designed for force X Nzsina-Nzcosafrp.

In addition, as can be seen from expression (4), if 3cosa-2 0 or a arccos2 / 3, i.e. edge 3 is detached from surface 4, it is therefore considered that a.max.arccos2 / Z, i.e. . a "48 °.

At the third stage of the load 1, through the platform (7), you can determine the required angle by which the load 1 needs to be deflected, which corresponds to the angle between the supporting surface 4 and the AC generator of the platform 2 at the initial moment of movement.

Claims (1)

Invention Formula The method of moving the load on the platform, mu 2, is in contact with the surface 4 in a mode of 20, which consists of: a a „„ 90 ° - p. The load 1 is under the action of the following forces: - the force of its own weight fixed on it, resting on the supporting surface, is turned in a vertical plane by a lifting device and then lowering it on a supporting surface, characterized in that The MU is rotated around its edge resting on the supporting surface to the position in which the center of gravity of the load is located above the specified edge, after which the platform is removed from the interaction with the lifting device to freely rotate around the edge, and the load is set on the platform in accordance with the ratio sa cargo; (l-cosa) - centro for the purpose of making the displacement easier, the platform inertial force of motion; 7 / n 5Sa-- tangential force of inertia of motion; N3 is the support reaction at point C on the side of surface 4, which is transmitted to platform 1 through platform 2 (DAVA). Designing these forces on the axes A and U, get Rx N -sincL - {- Tcosa-frpj,; (5) / 1 / I-A / ucosa- | -7 swa-L h. The displacement is taken along the axis, since, and the condition of sliding of the load 1 on the platform 2 along the surface 4 is determined, and then N sina- t-Tcosa Ncf p (6) where L / s / tr / tr, from equality (5) receive NZ P-Micosa-f Tsmoc. After substituting the values of all forces receive 35 GAD about sina. (2-cosa 40   2 l-cosa) -fcoPcx where / tr is the coefficient of friction between the platform and the supporting surface; a is the angle between the bottom surface of the platform and the supporting surface at the location of the center of the load bar over the edge of the platform. 2mg (l -cosa.) Sina + mgsinacosa h fng-2mg (-cosa) cosct- -mgsin-a .. Hence, after transformations, taking into account the equality sin a + cos a l, the expression fsina {2-cosa.)  2 (1-co5a) + sor (7) surface 4 and platform 2, from In this case, it is possible to determine the required angle by which the load 1 should be deflected, which corresponds to the angle between the supporting surface 4 and the AC generator of the platform 2 at the initial moment of movement. A method of moving a load on a platform, which consists in that the platform with a weight fixed on it, resting on a supporting surface, is rotated in a vertical plane by a lifting device and then lowering it on a supporting surface, characterized in that in order to make movement easier, The MU is rotated around its edge resting on the supporting surface to the position in which the center of gravity of the load is located above the specified edge, after which the platform is removed from the interaction with the lifting device to freely rotate around the edge, and the load is set on the platform in accordance with the ratio  in order to make movement easier, GAD about sina. (2-cosa   2 l-cosa) -fcoPcx where / tr is the coefficient of friction between the platform and the supporting surface; a is the angle between the bottom surface of the platform and the supporting surface at the location of the center of the load bar over the edge of the platform. Figg c Schig. 30 40 50 60 70 80 90 оС Compiled by A. Mazilkin Tehred A. KravchukKorrektor M. Sharoshi Order aCr 649Subscription „ VNIIPI Gosuda..vei „oo. Committee., Isoar ™ GTT / G Production Atte- racy Department of Commerce. Pa tent., Uzhgorod, ul. Gagarik, 101 Editor N. Bobkov Order 3956 require FIG. five