SU838495A1 - Method of testing articles for accelerating action - Google Patents

Description

The invention relates to testing equipment and is intended for dynamic testing, for example, navigation instruments that determine the motion parameters of various objects.

Known centrifugal stands containing a rotating platform, a carriage moving in the radial direction along the guides mounted on the platform, a counterweight connected to the carriage, and a drive for moving the carriage [1].

Stands are also known, containing a rotating platform, radial guides mounted on it, a balancing device, connected with it and mounted on · guides with the possibility of reciprocating movement of the carriage for installing the test products, an element for connecting the carriage with a balancing device and a carriage drive [2] .

The disadvantage of these stands is the large required power for the movement of the carriages, depending on the speed of the radial movement of the carriages and on the magnitude of the centrifugal forces acting on the carriages and balancing devices, which limits the possibility of obtaining high intensities of the change in acceleration.

The closest in technical essence and the achieved effect is the method, which consists in the fact that the carriage with the test piece mounted on it, placed on the centrifuge platform, is rotated, the latter is moved, moved at a constant speed, braked and the centrifugal force acting during the movement is balanced onto the carriage with the test article, by means of a composite counterweight associated with it, the individual masses of which are sequentially separated from the counterweight.

The engine power necessary for the radial movement of the device and the counterweight without taking into account the friction forces and aerodynamic drag, given that the radial movement mechanism is ideal, can be determined from the equation of motion of the machine unit in the differential Form

Assuming that the engine power is Ν ^ = Μ ^ · 4 ', we determine the amount of power necessary to obtain the unit of intensity of change in the rooting UU _n , i.e. -SE-;

W 838495 4 intensities of the change in acceleration) is equal to w UP / ₅ For acceleration or braking of the system in the radial direction in the 0.1 m section, the acceleration will be p = 46 m / s ² . In this case, the specific power is ¹⁰ i ^ ^{m +} < ^{= 0 '46} (^)

Those. the engine must be at least four times more powerful than necessary for the implementation of the operating test mode.

The purpose of the invention is to reduce the power of the drive radial movement of the carriage.

The goal is achieved

the fact that the acceleration of the carriage when it moves from the axis of rotation is carried out by an additional mass, add ₄ , - the mass of the device and the counterweight;

p p ^ - the installation radius of the device “ ⁵ and the counterweight;

- platform rotation speed;

p 'mda - the first transfer functions of the device and the counterweight;

H ’is the angle of rotation of the shaft of the radial displacement engine;

W is the intensity of the change in acceleration.

Moreover, we have n {y = -P'-const; rn-p = m _h Ru,; p ₄₀

P = -Pu

Then formula (l) takes the form

51?

(t + gpc) y-yp ¹ ) ³ [L-npDj ² (2)

Let the mass of the carriage with the device be t = 10 kg, which is transported to the carriage at the moment of acceleration start, and be separated from it at the moment of acceleration end; braking is carried out by attaching another additional mass to the counterweight at the time of braking; while the additional masses are associated with the mass of the entire counterweight relations.

The value of this ratio can be found as follows. Suppose that in the initial position, when the carriage with the device is at a minimum radius p = p _Ж1 - _п , an additional mass is attached to it, the magnitude of which is such that the resultant of centrifugal forces acting on the carriage, the counterweight and the mass of hl, provides the system with constant acceleration p. At the point p = p ^, the mass is separated from the carriage, while the acceleration ends. Moreover, (n ^ + nr + rnjj) ρ = (m, + m) pSl ² '-m y, (Lp) SI? (3) the maximum mass of the counterweight for the connection length of the device and the counterweight L = l, 3 m is σι ^ = 22.5 kg; speed 51 = 57.5 ^ 0; radial displacement velocity p = 3 m / s; rotational speed of the shaft of the radial displacement engine * * = 300 ^ / 0; the maximum value of the function of the position of the device _a = 0.9 m; the first transfer function is π '= ρ / ψ = 0.01 (m). Then, in the area of uniform motion, specific power (power per unit

Here, is the mass of the counterweight at the end of the acceleration section (i.e., its minimum mass).

Expressing mass from here, we see that it is a function of moving p and

-πι = ^ (ρ) (4)

To confine a constant weight to transform the expression _h t (p) based on the condition that the space ft -Pmin) = T (5)

Phhh

In this case, we find the constant additional ₅ mass at once: p ^m 4 ^_t r ^Ω N J „rpin ^r 'where H = p, -r _t - _m is the length

Considering that there exist forces acting on the carriage and proceeding about I _m -m _r -m, (6) i of the acceleration section, that at the point p - pj the centrifugal

838495 6 gu 4, which at one end is rigidly connected to the carriage 5 and has a stop 6 at the other end; additional weights 7 and 8 are planted on the bar.

The proposed method is as follows.

Platform 1 rotates at a constant speed I. · For the initial take the position of the carriage on. The maximum force acts on the carriage 5 ((, since the additional mass 7 is pressed against the carriage under the action of centrifugal force. At the emphasis 6 is the weight, we express the mass of the carriage m through the mass of the counterweight

I b-P <

^{m = m} n -

Substituting (7) .integral, we find that of (7) into (6) and the required opening sootnoshesh ^'1 _and ........

where W mi n = p mi η 5ϊ5, W. ₍ = p, 51 ^g centripetal carriage accelerations at the beginning and end of the acceleration section.

the force F ^ acts, which is less than the force F ^ by an amount determined by mass 7, and which, therefore, will provide acceleration of the system with a given acceleration p. At the end of phase I of acceleration, the additional mass 20 7 is delayed by the stop 9.

When the system moves in section II, the sequential connection of the counterweight plates 3 ensures the equality of centrifugal forces and F ₂ .

On the border of sections II and III to

Similarly, we find the expression for the mass m ^ attached to the counterweight on the braking section ^ 2 ^AND -P hti _{г r} where m _h

- the mass of the counterweight at the end of the section of uniform movement (i.e. the maximum mass of the counterweight);

W ^ L-fo) "- ¹ ; centripetal accelerations of the counterweight at the beginning and end of the braking section.

Given that the minimum mass of the counterweight through the maximum is expressed as follows

I 1-P2 pf ^m ti ^m h L-pd 'Pi' (10) we rewrite the expression for the mass m ^ * Гь-рДр * М ^н Чшр)

The drawing schematically shows a device that implements the proposed method.

These numbers refer to the following sections of the movement (when moving carriages ^ki Rumi ^{"ftwd: 1} ~ acceleration plot;

II - section of uniform motion;

III - braking area. On the platform 1 of the centrifugal test bench, a counterweight is installed, consisting of a hollow body 2 and a package of plates 3, laid on the counterweight 35, an additional mass 8 is attached, resulting in F ^. becomes larger than E, therefore, braking occurs due to the difference in centrifugal forces. At the end of section 111, the system stops. When the system moves in the opposite direction, mass 7 performs the functions of an accelerating mass, and mass 8 acts as a braking mass.

Using the proposed method for testing products can significantly reduce the power of the drive radial displacement and, consequently, energy costs. At the same time, the use of unbalanced masses causes a decrease in the power of the radial displacement drive by more than 400 ^.

Claims (3)

(54) A METHOD FOR SPITTING PRODUCTS TO ACCELERATE ACCELERATION which is consistently separated from the counterweight 3J, the engine power required for radial movement of the device and counterweight without considering the forces of friction and aerodynamic resistance, taking into account that the radial movement mechanism is ideal, can be determined from movements of the machine unit in the differential form d3 vf 2 Considering that the engine power M Мз-Ч determines the amount of power required to obtain the unit of intensity of change accelerated , Ie .) (p ii) .b (2П Sl where t, t is the mass of the device and against the weight; p p, is the installation radius and counterweight; Si. is the rotation speed of the platform; P (S), Pu, () - the first gear functions of the instrument and counter; H is the angle of rotation of the shaft of the motor of the radial displacement; W is the intensity of the acceleration change. At the same time, we have –const;; p - p; P –Pv ,. Then the formula (l) takes the form ., (...,). Vii-YP) 4V Let the weight of the carriage with the device be the maximum weight of the counterweight with the connection length of the device and the counterweight L, 3 m, 5 kg; speed fl 57 .S-fc; radial displacement velocity p-3 m / s; rotational speed of the radial displacement motor shaft 3001/0; the maximum value of the position function of the device is P (R) P, 0.9 m; first transfer function, 01 (m). Then, in the area of uniform motion, the power supply (power per unit of the intensity of change of acceleration) is equal to D to accelerate or decelerate the system in the radial direction over an area of 0.1 m, the acceleration will be p 46 m / s. In this case, the specific power is | 5 (t-τ,) 0.4b (,) Ie the engine must be at least four times more powerful than is necessary to carry out the operational test mode. The purpose of the invention is to reduce the power of the drive of the radial movement of the carriage. The goal is achieved by accelerating the carriage as it moves away from the axis of rotation with additional mass attached to the carriage at the moment when acceleration starts, and is separated from it at the moment when acceleration ends; braking is accomplished by adding another additional mass to the counterweight at the moment the braking begins; however, the additional masses are related to the mass of the entire counterbalance by ratios. The value of this ratio can be found as follows. Suppose that in the initial position, when the carriage with the device is at the minimum radius p, an additional mass p is attached to it, the value of which is such that the resultant centrifugal forces acting on the carriage, the counterweight and the mass rp, ensure the motion of the system with constant acceleration p. At the point p, the weight Шх is separated from the carriage, and the acceleration ends, with (t + t + 1T1) -p () (Lp) L (3) Here, gpu is the mass of the counterweight at the end of the acceleration portion (i.e. its mass is minimal). Expressing the mass m from here, we see that it is a function of the displacement p (, (I (4) In order to limit it to a certain mass of a constant value 5, we transform the expression for m (f), an outcome from the condition of equality of areas) Yyts) D) dp „PMiiiv. In this case, the constant additional mass t is found as follows: p t al4 g dp t g (6) RII, where H is p, the length of the section is accelerated Taking into account that at the point p p there must be equality of centrifugal forces acting on the carriage and counterweight, we express the mass of the carriage m through the mass of the counterweight W Substitute () in (6) and open it. integral, we find the desired relation H (b. G) where W m i p p m i n 51 W p, SJ is the centripetal acceleration of the carriage at the beginning and end of the acceleration section. Similarly, we find the expression for the mass m2 attached to the counterweight in the braking area - (AND (- € where Shu. Is the mass of the counterweight at the end of the uniform motion section (i.e., the maximum weight of the counterweight); W; :( L-I, ) Sg., (L-5,) ft- prices for the rapid acceleration of the counterbalance at the beginning and end of the braking section. Bearing in mind that the minimum mass of the counterweight through the maximum is expressed as follows: 1 - --PP - W - Rn W /. .- (i- | (-.-) - In the drawing a schematic representation of the device that implements the proposed method. Figures about the following areas of motion are indicated (when the PvnivifW carriages move, the acceleration section; II — steady motion section; III — braking section. On platform 1 of the centrifugal test bench, a counterweight is installed, consisting of a hollow body 2 and a pack of plates 3 placed on a piece / g 56 gu 4, which at one end is rigidly connected to the carriage 5 and has an abutment 6j on the other end of the bar, additional masses 7 and 8 are mounted on the rod. The proposed method is carried out as follows. Platform 1 rotates at a constant speed of 51-. For the initial position of the carriage is taken. On the carriage 5 is the maximum force F, since. additional mass 7 is pressed to the carriage by the action of centrifugal force. The stop 6 is influenced by the force F, which is less than the force F by an amount determined by the mass 7, and which, therefore, will provide acceleration of the system with a given acceleration p. At the end of the acceleration section I, the additional mass 7 is delayed by the stop 9. When the system moves on section II, the sequential connection of the plates 3 of the counterweight ensures equality of the centrifugal forces F and F2. At the boundary of sections II and III, an additional mass 8 is added to the counterweight, as a result of which F. becomes greater than F, therefore, braking occurs due to the difference in centrifugal forces. At the end of section 111, the system stops. When the system moves in the opposite direction, the mass 7 performs the functions of the accelerating mass, and the mass of 8 performs the functions of the braking mass. The use of the proposed method for testing products allows to significantly reduce the radial displacement drive power and, consequently, the energy costs. In this case, the use of unbalanced masses causes a reduction in the radial displacement drive power by more than 400%. Formula of the Invention A method for testing products for acceleration effects, which means that the carriage with the test article installed on it, placed on a centrifuge platform, rotates accelerated, moved at a constant speed, braked and in the process of moving balanced centrifugal force acting on the carriage with the test product by means of associated with it a counterweight, the individual masses of which are successively separated from the protivoschivayuschim. This is done by the fact that, in order to reduce the drive power of the radial movement of the carriage, acceleration of the carriage as it moves from the axis of rotation is carried out with additional mass attached to the carriage at the moment of start of acceleration, and braking is carried out by adding another additional mass to the counterweight at the time of the start of braking, while the additional masses are related to the mass of the counterbalance by ratios)) where r, P1, P1, are the accelerating, braking and full mass of the counterweight; L is the distance between the centers of mass of the carriage with the device and the protractor; the distance from the axis of rotation to the center of mass of the carriage with the device at the moment of the beginning and end of uniform motion; the continuity of the acceleration or deceleration section,, K., n .. n -1 centripetal accelerations at the moments of the beginning and end of the acceleration of the carriage and the turning of the carriage; the magnitude of the constant acceleration of the radial displacement in the acceleration or deceleration section. Sources of information, ntye taken into account in the examination 1. US patent number 3180131, 73-1, 1965. 2. Authors certificate of the USSR 36828, cl. G 01 M 7/00, 1967. 3. Authors certificate of the USSR 24094, cl. G 01 M 19/00, 1976 ootype).