RU2734801C1 - Hammer - Google Patents

Abstract

FIELD: machine building.

SUBSTANCE: invention relates to machine building and can be used in construction for driving piles and driving wells, as well as for cleaning bins and cars. Hammer comprises housing accommodating air receiver connected with compressed air source, as well as armature and armature of electromagnet. Core is made in the form of shell from diamagnetic material, in which there are electric coils and powder from electrical steel. Anchor is made in the form of shell from diamagnetic material with powder from electrotechnical steel and with sealing elements on external surface. Anchor is installed with formation between its shell and shell core volume connected to receiver. Anchor moves in case until it contacts with core under action of magnetic force and in reverse direction before collision with impact plate under action of air pressure in receiver and own weight.

EFFECT: result is increased frequency of slaps.

1 cl, 2 dwg

Description

The proposed invention relates to the field of mechanical engineering and can be used as forging and pressing equipment, in construction for driving piles and driving wells, as well as pneumatic generators for cleaning bunkers and wagons.

Known steam-air hammer (Beletsky BF "Construction machines and equipment" Rostov-on-Don 2002, p. 216 Fig. 14.2a - prototype). The known device contains a massive cast-iron body 1 with guide grips 2, cover 3, piston 6 with a rod 7. Inside the cover there is a distribution device consisting of a rotary valve 5 and a rocker arm 4. After lifting the body 1 to a predetermined height, a rotary valve opens, which allows air leak into the atmosphere. As a result, the hammer body falls down under its own gravity and strikes.

This device is shown in FIG. 1 and taken as a prototype. It has a number of significant disadvantages:

- high energy consumption for compression and air consumption;

- low frequency of impacts.

The object of the proposed invention is to increase the frequency of impacts and reduce energy consumption.

The problem posed has a development in that the core and the armature of the electromagnet contain a shell of a diamagnetic material, and electric coils and powder made of electrical steel are installed in the shell of the core, and sealing devices are installed on the shell of the armature, and inside the powder is made of electrical steel.

FIG. 2 shows the proposed device, for example, for drilling large-diameter wells (frontal view). It contains a housing 1 made of a diamagnetic material, which is mounted on a shock plate 2. In the housing 1 there is a receiver 3, an opening 4, a core shell 5 and an armature shell 6. The core shell 5 contains electric coils 7 and powder 8 made of electrical steel. On the outer surface of the shell of the armature 6, sealing elements 9 are installed, and inside there is powder 8. The impact plate 2 is installed on the pipe 10, and holes 11 are used to discharge air into the atmosphere from the pipe 10 and housing 1.

The hammer works as follows. In the initial position, the shell of the armature 6 is installed in the lower part of the housing 1. Then air is pumped into the receiver 3, which, through hole 4, enters the volume between the shell of the armature 6 and the shell of the core 5, and the formed volume is equal to 10% of the volume of the receiver 3. After filling the internal volume to a specified minimum pressure, the compressed air source is disconnected from the receiver 3.

After filling the internal volume with compressed air, the force acts on the shell of the armature 6:

where P _min is the minimum air pressure in the receiver 3;

S ₁ - the area of the shell of the armature 6.

Then voltage is applied to the electric coils 7, which sum up the magnetic fluxes of all electric coils 7 and induce a magnetic force between the shells of the core 5 and the armature 6. The magnetic force acting on the shell of the armature 6, according to Maxwell's formula, will be equal to:

where B is the magnetic induction in the air gap between the shells of the core 5 and the armature 6;

μ ₀ - magnetic constant;

c - coefficient equal to the ratio of the area of the shell of the core 5 to the area of the shell of the armature 6.

Under the influence of the magnetic force according to the formula (2), the shell of the armature 6 begins to move towards the shell of the core 5, only when the current in the electric coil 7 after the transient process caused by the inductance of the coil 7 reaches a maximum value. Moreover, the upward movement occurs with an increase in magnetic force due to a decrease in the air gap between the powders 8 of the core 5 and the armature 6, as well as an increase in pressure in the receiver 3 due to a decrease in the volume between the shells of the rod 5 and the armature 6. After the contact of the shells of the armature 6 with the core 5, electrical the coils 7 are turned off, and the kinetic energy of the armature shell 6 is transferred to the core shell 5 and the air in the receiver 3 due to the pressure increase. After stopping the shell of the armature 6, it will begin its reverse movement to the impact plate 3 under the action of the force of the maximum air pressure in the receiver 3 and its own weight. At the moment of elastic collision of the armature shell 6 with the shock plate 2, the armature shell 6 transfers its kinetic energy to the shock plate 2 and the pipe 10. After the impact, the electric coils 7 are switched on and the process is repeated.

In the proposed device, the impact energy significantly depends on the value of the saturation induction of the electrical powder 8 and the volume of air between the shells of the rod 5 and the armature 6 according to the ratios:

N = P⋅V = P⋅S ₁ ⋅L = s⋅V ² / μ ₀ ⋅S ₁ ⋅L [J]

where P is the maximum pressure in the receiver 3;

V is the maximum volume between the shells of the rod 5 and the armature 6;

c - coefficient equal to the ratio of the magnetic area of the shell of the core 5 to the area of the shell of the armature 6;

B - magnetic field induction in the air gap between the powders 8 in the shells of the core 5 and the armature 6;

μ ₀ - magnetic constant;

S ₁ - the area of the shell of the armature 6;

L is the distance between the shells of the core 5 and the armature 6. The speed of the device depends on the rise time of the current in the electric coil 7 in the transient process, which will be equal to:

where τ is the time constant of a circuit consisting of an inductance and a resistor;

R is the electrical resistance of the coil 7;

Δ is the maximum gap between the powders 8 of the armature 6 and the core 5;

w _K - the number of turns in the electric coil 7;

S ₂ - area of powder 8 in the core 5.

Thus, according to formula (3) in the proposed device, you can easily achieve speed due to the small number of turns of the electric coil 7 and its increased resistance.

According to calculations, when using powder 8 of electrical steel with a saturation induction of 2.18T, a particle size of 50-80 10 ^{-6 m} and a coefficient of C = 0.365, the proposed device contains:

- an anchor of an electromagnet 6 with a mass of 2100 kg, a receiver 3 with a volume of 1.9 m ³ ,

the maximum pressure in the receiver is 1.05 MPa and the minimum pressure is 0.945 MPa. The electrical power consumed by the device is 29410 W, the number of strokes per minute is 372 with an armature shell stroke of 6 0.065 m. The impact energy is 100 kJ with a diameter of 1420 mm, a length of 2500 mm and a mass of 10000 kg.

Similar parameters of the device of the prototype C-812 A are respectively equal:

- the hammer mass 8000 kg, impact energy of 100 kJ, the number of beats per minute 35-40 piston stroke of 1.37 meters, the compressed air flow 26 m ³ / min at a pressure of 1 MPa, electric power of 600 kW compressor, device dimensions × 4730 1070 × 1270 mm, weight 11000 kg.

Comparative analysis shows that the proposed device, using an electromagnet armature as the striking part of the hammer, has a high frequency of strikes and almost an order of magnitude less energy consumption. Also, the device, when used as a drilling rig, will not require drilling fluids and special high-pressure pumps to remove soil from the well during drilling, since the soil in the form of a core will be removed along with pipe 10. After replacing the pipe 10 filled with soil, the drilling process can continue.

Literature

1. G.V. Butkevich, V.G. Degtyar, A.G. Slivinskaya "Problem book on electrical devices" M. HIGH SCHOOL 1977 p. 111.

2. H. Kuhling "Handbook of Physics" M. MIR 1985, p. 112.

Claims (1)

A hammer containing a body and an impact plate, characterized in that it is equipped with an air receiver located in the body, connected to a compressed air source, a core and an electromagnet armature, while the core is made in the form of a shell of diamagnetic material, in which electric coils and powder are located electrical steel, and the armature is made in the form of a shell of diamagnetic material with powder of electrical steel and with sealing elements on the outer surface and is installed with the formation between its shell and the shell of the core of a volume connected to the receiver, and with the ability to move in the housing until contact with the core under the influence of a magnetic force and in the opposite direction until it hits the impact plate under the influence of air pressure in the receiver and its own weight.

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