SU603576A1 - Percussive-action pneumatic machine - Google Patents

Description

one

The invention relates to a device of percussion impact machines with a nickel, for example, a reciprocating working body, used in the construction and industry as technological equipment.

A device of pneumatic percussion machines is known, the air distribution system of which is discharged using flat valves l.

Closest to the technical essence of the present invention is a pneumatic percussion machine, comprising a body, a barrel with a hammer in it, forming a rear and front working chambers, a coaxial socket for the working tool and an air-distributor with a distribution cover 2.

In these machines, the valves practically throughout the working m-iKna are in the state of launching compressed air into one of the working chambers and the access of compressed air to each of the working chambers occurs only after it is connected to

the atmosphere. Thus, the valve air distribution works without cutoffs of the compressed air supply, i.e. without forcibly stopping the supply of air at a given point of the trajectory of the striker before the chamber communicates with the atmosphere. Duty-free cycles are characterized by an increased consumption of compressed air and a higher level of aerodynamic noise. The cutoffs of the compressed air supply at predetermined times allow more flexible formation of the law of pressure change in each of the working chambers, which, as is well known, largely determines the vibration-force parameters, ceteris paribus.

In addition, uncontrolled leakage of compressed air through the gaps, in some cases, disrupts the normal operation of the machine (especially when operating at elevated pressures of compressed air) and impairs its efficiency.

In order to reduce the consumption of compressed air, as well as noise and vibration, the air distribution device is made in the form of three elastic membranes, arranged in series so that they form, with an internal angle of the barrel, between the distribution cover and the half-diaphragm supply chamber communicated with the main between the first and second diaphragms — a drainage chamber in communication with the atmosphere; between the second and third diaphragms; a control chamber connected to the channel with the rear working chamber; between the third membrane and an additional barrel bottom (retaining chamber in communication with the main, the cross-sectional area of the control chamber is larger than the cross-sectional area of the feed chamber. To increase reliability, pushers transmitting the axial forces occurring on the membranes are placed between the diaphragms. The drawing shows machine, longitudinal section. The machine includes a housing 1, a barrel 2 containing a feeder 3, located in front of the trigger valve 4 with channels 5 and w, a current 6, together a longitudinal feed channel Al 7 through the radial hole 8 with the front (starter) chamber 9. The air distribution device, made in the form of three elastic wounds 1О, 11, 12, is arranged so that the axes form with the inner surface of the barrel 13 respectively between the distribution cover 14 and membrane 1O feeding chamber 15 connected to the main by channels 7 and 16, between membranes 10 and 11 - a drainage chamber 17 with a pusher 18 placed in it, between membranes 11 and 12 - a control chamber 19 with a pusher 20 located in it, connected channel 21 with ass The working chamber 22, between the membrane 12 and the bottom of the barrel 23, is an additional (retaining) chamber 24. In the end wall of the rear working chambers 22 a power hole 25 is made, in the side wall of the barrel 2 there are exhaust holes 26, in the front part of the working cylinder of the barrel 2, the channels 27 are connected to the opening 8. The machine also contains a drummer 28, which is once mixed in the working cylinder of the barrel 2. In the housing 1 there is a chamber 29, which is permanently connected through the opening 30 to the highway. A working tool 31 is located in the front part of the housing 1, and a window 32 on the side surface of the barrel 2, which is combined with the exhaust ports 26. The machine operates in a spedmed mode. In the initial position, the barrel 2, the striker 28 is in the extreme forward position, while the rod 6 of the triggering spool 4 is sunk into the barrel 2. In the recessed position, the spool 4 through channel 5, hole 8, channels 27 communicates the triggering chamber 9, with supply channel 7, and through it, the camera 29 and the hole ZOR with the highway. Under the pressure of compressed air acting in the launch chamber of chamber 9, the striker 28 reverses in the launch phase. After the drummer 28 blocks the exhaust hole 26 with its rear edge, the rear working chamber 22 begins to compress free air and the pressure increases, and through the hole 33 the channel 21 compressed air is supplied to the control chamber 19. With the further progress of the hammer 28, the pressure in the rear the working chamber 22 rises and is transmitted through the opening 25 to the membrane 1O. Thereafter, the striker 28 with its front edge will open the aperture.33 and communicate the control chamber 19 through the aperture 26 and the window 32: with the atmosphere. After the pressure in the control chamber 19 is comparable with the atmospheric pressure, the membrane 10 is affected by pressures of compressed air from the side of the annular supply chamber 15 communicating through the channel 16 to the supply channel 7 and the orifice 25 from the rear working chamber 22. The cross-sectional dimensions of the supply chamber 15, the additional (supporting) chamber 24 and the aperture 25 are chosen such that the pressure forces acting backwards (in the direction of the feeder 3 of the barrel 2) exceed the force acting Forward. Under the action of the resultant of the indicated forces, the membrane 10 bends and communicates the annular supply chamber 15 with an opening 25, opening access of compressed air to the rear working chamber 22. Under the action of a pressure force, the impactor 28 starts forward movement. After the drummer 28 opens the opening 33 with its rear edge and informs the control chamber 19 with the rear working chamber 22 through the channel 21, the resultant pressure force formed in the control chamber 19, the retaining chamber 24, the supply chamber 15 will act on the membrane 10 , and in the rear working chamber 22. Since the cross section of the chamber 19 substantially exceeds the cross section of the hole 25, the resultant pressure forces are equal to Bnejjea (towards the working

tool. Under the action of this force, the membrane 1O blocks the connection of compressed air from the supply chamber 15 to the opening 25, thereby making a preliminary cut-off. Further, the switch is repeated. It is possible to design when a valve located between the membrane 1O and the supply chamber 1 is used as the air distribution element.

Claims (3)

Elastic membranes make it possible to eliminate yTaqjcH in functional chambers, which substantially increases the reliability of the operation of the machines, as well as to ensure low inertia of the air distribution. Placing separator pushers between the membranes ensures minimal deformation of the membranes and also prevents their gluing in some cases. Invention Formula 1. A pneumatic percussion machine, comprising a body, a barrel with a hammer in it, forming a rear and front working chambers, a socket for the working tool coaxial with it, and an air-distributing device, with a distribution cover, in order to reduce the flow of compressed air as well as noise and vibration, the air distribution device is made in the form of three elastic membranes, sequentially arranged so that they form with the inner surface of the barrel, respectively waiting for the distribution cover and the first membrane supply chamber connected to the main between the first and second diaphragm - drainage chamber in communication with the atmosphere, between the second and third diaphragm - control chamber communicated with the channel from the rear working chamber between the third membrane and the bottom of the trunk - additional (retaining) camera communicated with the highway. 2. A machine in accordance with claim 1, wherein the cross-sectional area of the control chamber is larger than the cross-sectional area of the feed chamber. 3. Machine on PP. 1 and 2, characterized in that, in order to increase the reliability of operation, between the membranes of pa. The pushers are placed, transmitting axial forces arising on the membranes. Sources of information taken into account in the examination: 1. Author's certificate No. 276855, cl. In 25D 17/24, 1969. 2. Sudnishnikov B.V. and Esik N.N. The air diffuser of pneumatic impact machines of the Siberian Branch of the Academy of Sciences of the USSR Novosibirsk, 1965. p. 7