SU1579766A1 - Compression-vacuum machine of percussive action - Google Patents

Abstract

This invention relates to compression-vacuum percussion machines. The purpose of the invention is to increase the efficiency in processing materials with different hardness. The mass M of the impactor is selected from the relation connecting the area F of the cross section of the impactor, the radius R of the crank and the specified frequency @ of the rotation of the crank. 5 il.

Description

The invention relates to percussion machines, namely, electric hammers and bostonomers, using an air cushion in percussion mechanisms.

The purpose of the invention is to increase the efficiency in processing materials with different hardness.

Figure 1 shows a percussion machine (the basic version with a stationary cylinder), a general view; figure 2 is the same, a variant with a stepped cylinder; on fig.Z - the same, option with the mobile cylinder; figure 4 is the same, option with a hollow cylinder brisk; figure 5 - the same, the version with a stationary cylinder and two-chamber scheme.

The machine includes a housing 1 housed in a housing 1, a rotational drive 2, a cylinder 3; a crank type conversion mechanism 4 with a crank 5 of radius g connecting the rotational drive with the piston 6.

Compensation holes 7 and 8 are located in the stationary cylinder 3. Between piston 6 and drummer 9 with mass m and area F, a working chamber 10 is formed, having an initial height H0. The working chamber 10 is filled with air at an initial pressure PO. In the lower part of the housing j there is a working tool 1 consisting of an intermediate element 12 and a working tip 13. In the lower part of the stationary cylinder 3 there are holes 14 and 15 for air release. In the machine, there are a nadporshnev cavity 16 and a cavity 17 under the hammer 9, communicating with each other. The mass m of the drummer 9 is selected from the rotational frequency of the crank 5, equal to and, the radius r of the crank 5 and the area F of the drummer, related by

WITH:

pi

V,

J3f j

mru

0.50 ... 0.65,

where / 3 is a constant coefficient equal to 0.10 f MPa and numerically equal to the initial air pressure P0 in the working chamber 10.

The parameters p, F, m, r and i) are known in percussion machines using an air cushion, are determined by the design of the machine and are indicated in the working documentation and in the passports of the machine. Rig parameters determine the size of the machine; the parameter w determines the size of the gearbox and is indicated on the machine label. In turn, the set of parameters m, r and w largely determines the shock power of the machine, as well as the drive power consumption; the set of parameters F, m, r, and co determines the stable starting characteristics of the rotary drive.

The parameters m, r, and F can be measured on an idle machine by conventional metrological means.

In the embodiment of the machine on a stepped stationary cylinder 3 (figure 2), the drive piston 6 is located in the cylinder of a larger diameter, and the hammer is in a cylinder of a smaller diameter, having an area F.

According to figure 3 in the machine with a movable cylinder placed drummer 9, and the movable cylinder is placed in a stationary cylinder 3.

Figure 4 presents a variant in which the hammer 9 is made in the form of a hollow cylinder. In the machine according to FIG. 5, the stationary cylinder 3 has a partition 18 dividing the crankcase space of the machine into two chambers: the overpiston cavity 16 and the cavity 17 under the impactor 9, communicating with each other through the holes 19.

The percussion machine works as follows.

When the rotational drive (not shown) is working, the rotation of the crank 5 is transformed through the conversion mechanism 4 into the reciprocating movement of the piston 6. When the piston 6 moves upwards from the position of the bottom dead center in the working chamber 10, filled

With air at an initial pressure P0, a discharge (vacuum) is formed. Under the action of pressure drop in the working chamber 10 and cavity 17, the drummer 9

0

five

0

five

0

five

0

five

0

five

detaches from the working tool 1 1 and moves after the piston 6. At the same time, through the side openings 7 and 8, air is drawn in from the crankcase of the hammer (not indicated).

Thus, the air losses from the working chamber 10 occurring during the previous cycle are compensated. The diameters of the lateral compensation holes 7 and 8 are chosen so that the speed of movement of the striker 9 does not change under vacuum in the working chamber 10.

When the piston 6 passes its upper dead center, the airbag in the working chamber is stretched, as the impactor 9 lags behind the speed of the piston 6. After the piston 6 passes through the top dead center, the impactor 9 moves by inertia towards the piston 6. and, at a certain point in time, the air pressure in the working chamber 10 becomes equal to the initial value T0.

When the striker 9 and the piston 6 approach each other, the air pressure in the working chamber 10 increases until the elastic force of the compressed air stops the impactor 9. When the air in the working chamber 10 is compressed, part of the air is forced out through the fit-holes of the impactor 9 and cylinder 3.

The piston 6 continues to move downward, and the hammer 9 changes the direction of movement. At the same time, the compressed air expands, jointly accelerating the striker 9. The latter strikes the working tool 11 consisting of successive intermediate element 12 and working tip 13, transfers the impact energy to the material being processed, bounces off the tail of intermediate element 12 at a certain speed, from the strength of the material being processed, and then picked up on a vacuum as the piston 5 moves.

The duty cycle of the machine is repeated.

Claims (1)

Invention Formula A compression-vacuum percussion machine, comprising a housing, a rotational drive housed therein, a cylinder with compensation holes, mounted in the cylinder and 515 the hammer and piston forming the working chamber with it, the crank type conversion mechanism connecting the rotational drive and the piston, and the working tool, so that, in order to increase the efficiency in processing materials with different hardness, the mass m of the impactor is chosen from the ratio --Ј -, - 0.50 ... O, 65, mr ш 2 five ten where / 3 is a constant coefficient equal to 0.10 MPa; F is the cross-sectional area of the impactor; g is the radius of the crank; LO is the predetermined rotational speed of the crank. Fig 2 fig.Z TI% 7 FIG. four Editor A. Shandor Compiled by G. Lukashevich Tehred M. Khodanich Proofreader M. Pojo Order 1983 Circulation 672 VNIIPI State Committee for Inventions and Discoveries at the State Committee for Science and Technology C (; CP 113035, Moscow, Zh-35, 4/5 Raushsk Nab. Production and Publishing Combine Patent, Uzhgorod, st. Gagarin, 101 FIG. five Subscription