Method of dynamic damping and dynamic damper

FIELD: machine building.

SUBSTANCE: tuning to required damping frequency is performed. Dynamic rigidity or transfer factor dip is experimentally determined at first breadboard specimen. Then on increasing damper slit width, tuning frequency is increased along with increasing damping. Thereafter, tuning frequency is decreased by decreasing damper slit width. Aforesaid reduction is performed by increasing the number of slit pairs. Proposed device comprises interconnected pendulums pivoted to protected object. Each pendulum comprises weight suspended to aforesaid object. One object is located above the points of attachment of its suspension to the object, the others being located below aforesaid points. Tight cylindrical barrel is covered with cap and filled with hydraulic fluid. Movable modular hollow piston is arranged inside aforesaid cylindrical barrel fixed between two cylindrical springs. There is a system of channels inside aforesaid piston. It consists of top and bottom covers and uneven number of round plates. Aforesaid slits are formed by flat round rings arranged between aforesaid covers and plates. Former and latter comprise central bores, while even plates have peripheral orifices arranged nearby inner cylindrical surfaces of round rings.

EFFECT: higher efficiency.

2 cl, 3 dwg

 

The invention relates to a device for damping oscillations of construction projects, primarily high-rise type buildings high-rise frame poles, television and radio towers, chimneys and ventilation ducts, masts, etc.

The closest technical solution to the stated object is a dynamic vibration damper on the as of the USSR №920143, E04B 1/98, 1979, containing interconnected links pendulums, pivotally connected to the protected object, each of which has a weight attached to the object of the suspension, and at least one mass is located above the points of attachment of its suspension to the object, and the rest below the attachment points of their suspensions, with at least one weight connected to the protected object through the damping device.

A disadvantage of the known construction is that the damper works reliably and has a simple performance at frequencies up to about 0,41-1but at lower frequencies the length of the pendulum and the amplitude of their fluctuations are so large that it leads to considerable difficulties in the implementation of the design of the absorber and its use. In addition, in the known damper is insufficient damping ability of the oscillations of the pendulum.

The technical result - improving the efficiency of dynamic damping C is by increasing the dampening of the vibration damper.

This is achieved by a method of dynamic damping, namely, that perform the tuning to the desired frequency, damping, on the first model sample experimentally receive a failure in the dynamic stiffness or gain at a certain frequency, and then increase the frequency with increase in damping due to the increase of the width of the slits of the damper, the increase in the frequency perform proportional to the square of the width of the slit, and then lower the tuning frequency by reducing the thickness of the slits of the quencher, thus lowering the frequency of exercise is proportional to the square of the width of the slit, and lowering the tuning frequency is produced by increasing the number of pairs of slits, thus lowering the frequency perform proportional to the square of the number of pairs of slits.

This is achieved by the fact that in the dynamic vibration damper containing interconnected links pendulums, pivotally connected to the protected object, each of which has a weight attached to the object of the suspension, and at least one mass is located above the points of attachment of its suspension to the object, and the rest below the attachment points of their suspensions, with at least one weight connected to the protected object through the damping device contains a hermetically sealed cylindrical housing-glass, ukryty cover and filled with a liquid, and inside of a glass is movable prefabricated hollow piston mounted between two cylindrical springs, which their other ends rest against the first spring in the bottom of a glass, and the second spring in the cover-glass, while inside the piston Assembly is a system of channels through which the liquid is transferred from the upper cavity to the lower cavity when the piston up and out of the lower cavity to the upper cavity when the piston down while over the inside of the piston is flat on the cracks from the center to the periphery and from the periphery to the center, and the piston is assembled the screws of the two covers: one for the top and bottom and an odd number of round plates, and slits are formed flat round rings of rectangular cross section, defined between the caps and plates, while the entire composition forms a number of pairs of slits, and the upper and lower cover and the odd plate contains a Central hole, and even plates contain the maximum number of peripheral holes with a diameter of 2-3 mm, close to the inner cylindrical surfaces of the round rings.

1 shows a frontal section of the proposed dynamic vibration damper, figure 2, 3 - circuit damping device.

The way dynamic damping is carried out as the way.

On the first model sample experimentally receive a failure in the dynamic stiffness or gain at a certain frequency, and then increase the frequency with increase in damping due to the increase of the width of the slits of the damper, the increase in the frequency perform proportional to the square of the width of the slit, and then lower the tuning frequency by reducing the thickness of the slits of the quencher, thus lowering the frequency of exercise is proportional to the square of the width of the slit, and lowering the tuning frequency is produced by increasing the number of pairs of slits, with the downconverter perform proportional to the square of the number of pairs of slits.

The dynamic vibration damper comprises a cylindrical housing-glass 1, the cover 2, tightening the bolts 3 and nuts 4, the gasket 5, tube 6 with o-ring, screws 7 housing-Cup 1 to the base 17. Inside of a glass 1 is precast hollow piston 8. The piston 8 is sandwiched between the springs 9 and 10, rests in the cover 2 and the bottom of the Cup 1. The piston 8, in turn, consists of upper and lower covers 11, the plate pack of 12 from the peripheral holes of the plate pack 13 with a Central hole. Cover 11 and plate 13 are interleaved with the plates 12. Between all caps and plates installed ring of rectangular cross-section 14. The external diameter of the rings 14 coincides with the wew is indoor the diameter of the Cup 1. The peripheral openings in the plates 12 are evenly spaced around the inner diameter of the ring 14 (see figure 2) Diameter of holes of the order of 2-3 mm, distance between holes about 2 mm Assembly of the piston 8 tighten the screws 15 and nuts 16.

The dynamic vibration damper works as follows.

Hydraulic damper works as follows. The base 17 comes in an oscillatory motion. This movement makes the housing Cup 1 with a lid 2. Through the springs 9 and 10, the oscillating motion is transmitted to the piston 8, which makes this movement relative to the body of the Cup 1. Fill the internal cavity of the hydraulic damper fluid flows from the upper cavity with a spring 9 in the lower cavity with the spring 10 and back. The course is as follows. The piston 8 relative to the body of the Cup 1 is moving, for example, up. Through the Central hole in the top cover 11, the liquid comes in flat gap between the lid 11 and the plate 12 and spreads along the radii, leaking through the peripheral openings in the plate 12 into the next gap between plate 12 and plate 13 with a Central hole and then into the next gap between the plate 13 with a Central hole and a plate 12 with peripheral holes, and so on, until you get to the chamber with the spring 10 through the Central opening in the bottom cover 11. PR is introduced the liquid mass

where mCRis the reduced mass, And the area of the piston, R is the radius of the piston p is the density of the fluid, h is the slit width, rothe radii of the inner holes of the caps 11 and plate 13, n is the number of pairs of slits. From the formula (2) shows that decreasing h and roand the increase in n increases the mass. But the decrease in h and roleads to increased hydraulic resistance, and it is necessary to use a more accurate formula hydrodynamics, taking into account the viscosity and inertia of the working fluid. The minimum number of pairs of slits n=1.

Inside the rolling piston Assembly is a system of channels through which the liquid is transferred from the upper cavity to the lower cavity when the piston up and out of the lower cavity to the upper cavity when the piston down. Over the inside of the piston is flat on the cracks from the center to the periphery and from the periphery to the center. If the relative motion of the fluid momentum has been established, called the inertial effect of the transformer, and with the small mass enclosed in the piston fluid, multiplies the reduced mass of fluid moving relative to the housing. The value of the given mass is directly proportional to the number of pairs of slits, in which there is fluid flow, and inversely proportional to the thickness of the cracks. The course takes place in the first method, the if input from the Central hole in the partition and through a large number of small parallel holes at the outer radius in the next partition and Vice versa takes place from the periphery to the center. Therefore, the frequency settings

where C is the total stiffness of the spring, mg- the mass of the absorber, mtis the reduced mass inertia of the transformer.

If on the first model sample at n=1 experimentally obtained failure in dynamic rigidity or gain at a certain frequency, then increase the frequency with increase in damping due to the increase of the width of the slits. To increase the tuning frequency should increase the width of the slits. Increasing the frequency will be proportional to the square of the width of the slit. To lower the tuning frequency should decrease the thickness of the cracks. Lowering the frequency will be proportional to the square of the width of the slit. To lower the tuning frequency may increase the number of pairs of slits. Lowering the frequency will be proportional to the square of the number of pairs of slits. Reducing the width of the slits is possible up to a certain limit. When the width of the slot is less than one millimeter viscous resistance to flow of fluid will destroy the inertial effect.

The proposed device makes it possible, by expanding the range of the ratio of the moments of inertia of the pendulum significantly reduce the frequency of vibrations of the damper. When this is achieved considerable (1.2-1.4 times) the size of a damper, which is quite often, especially in high-rise structures, and eat great value.

1. The way dynamic damping, namely, that perform the tuning to the desired frequency, damping, characterized in that on the first model sample experimentally receive a failure in the dynamic stiffness or gain at a certain frequency, and then increase the frequency with increase in damping due to the increase of the width of the slits of the damper, the increase in the frequency perform proportional to the square of the width of the slit, and then lower the tuning frequency by reducing the thickness of the slits of the quencher, thus lowering the frequency of exercise is proportional to the square of the width of the slit, and lowering the tuning frequency is produced by increasing the number of pairs of slots, with decreasing frequency proportional to perform the square of the number of pairs of slits.

2. The dynamic vibration damper containing interconnected links pendulums, pivotally connected to the protected object, each of which has a weight attached to the object of the suspension, and at least one mass is located above the points of attachment of its suspension to the object, and the rest below the attachment points of their suspensions, with at least one weight connected to the protected object through the damping device, characterized in that it comprises a sealed cylindrical housing-glass, closed the second cover and is filled with liquid, and inside of a glass is movable prefabricated hollow piston mounted between two cylindrical springs, which their other ends rest against the first spring in the bottom of a glass, and the second spring in the cover-glass, while inside the piston Assembly is a system of channels through which the liquid is transferred from the upper cavity to the lower cavity when the piston up and out of the lower cavity to the upper cavity when the piston down while over the inside of the piston is flat on the cracks from the center to the periphery and from the periphery to the center, and the piston is assembled with screws two covers: one for the top and bottom and an odd number of round plates, and slits are formed flat round rings of rectangular cross section, defined between the caps and plates, while the entire composition forms a number of pairs of slits, and the upper and lower cover and the odd plate contains a Central hole, and even plates contain the maximum number of peripheral holes with a diameter of 2-3 mm, close to the inner cylindrical surfaces of the round rings.



 

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