SU1321812A2 - Pneumatic hammer with throttling air control - Google Patents

Description

The invention relates to the mining industry, 13 particularly to pneumatic percussion machines for the destruction of rocks and frozen soils, and is an improvement to the invention by the authors. St. NO 1285147.

The aim of the invention is to improve the sanitary characteristics of the hammer due to smoother pressure control in the mutual assistance of working chambers.

FIG. 1 shows a pneumatic hammer, a partial longitudinal section; in fig. 2--5 are variants of a hollow cylindrical element with fragments and bottom of a jib moving relative to each other.

A pneumatic hammer with throttle air distribution consists of a body and a drummer 2 placed nominally in it, which separates the chambers of the working 3 and idle 4 strokes. The housing 1 on the side of the chamber 3 is provided with a non-movable cover 5 with throttle inlet channels 6 and 7. On the side of the camera 3, an accumulator chamber 8 is formed in the form of a hollow cylindrical eleiteite with a deaf movable cover 9 and a stationary bottom 10 with a bypass choke channel 11 permanently connected camera 8 and 3 between them. Air in the wall of the housing 1; -1.water n.1, its channels 12 and 13, permanently connected to the throttling inlet channels 6 and 7 and from the outlets 4 and 15 to the chambers 3 and 4, as well as the outlet Channel 16, periodically depending on the position of the striker 2, communicating chambers 3 and 4 with the graving chamber 17 and through channels 18 in the casing 19 with the atmosphere. The fixed edge 5 is tightly pressed to the end of Cornus 1 by the handle 20. Between the deep cover of the fixed cover 9 and the non-moving roll 5, a buffer chamber 21 with a spring 22 installed in it is formed. Between the cover 5, handle 20 and case I, an annular tip is formed chamber 23, connected device M. of trigger device of handle 20 with network of energy-source (compressed air) In the central channel

24 cases 1 with the opposite handle 20 of the side mounted working tool

25 with the possibility of cooperation with the drummer 2. The tool 25 relative to the body is fixed with an end spindle 26.

The varnants of separating a hollow cylindrical element into a blind cover 9 and an annular bottom 10 presuppose their implementation in the form of a cup or a disk with - guiding walls 27 and 28. The removal of movable covers in the form of a disk is shown in FIG. I for a blind cover 9 and in FIG. 2 for day 1.a 10. G1odvil on the cover 9 in the form of a glass is shown in FIG. 2-5, and the bottom 10 also in the form of a glass — in FIG. 1 and 3-5. With this dawn 10

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and. it has guide walls 2 /, and the cover 9 is deaf, with nanowire walls 28.

Pneumatic hammer with throttle ventilation is as follows.

When the trigger device of the handle 20 is turned on, compressed air flows from the network into the annular flow chamber 23, from which it continuously flows through the throttle inlet channels 6 and 7 in the lid 5 and further along the air inlet channels 12 and 13 and their terminals 14 and 15 in the central channel 24 enclosures 1 in controllable working hours 3 and idle 4 strokes, respectively.

Since (in the position in FIG. 1) the chamber 3 is connected through the outlet channel 16 to the exhaust chamber 17 and through the channels 18 in the housing 19 with the atmosphere, the air flowing from the network into the chamber 3 is extracted and the pressure is maintained in it similar in size to atmospheric. Provides the datapod, holding such pressure, that the flow area of the exhaust channel 6 is substantially less than the flow area of the exhaust channel 16.

The air flowing into the chamber 4 accumulates, the pressure in chamber 4 rises and under the action of the force impulse formed, the impactor 2 begins to move from the tool 25, making it idle. After the drummer 2 closes off the outlet channel 16, the chamber 3 with the atmo- sphere disintegrates and air starts to blow into the channel. A part of the air cut off in chamber 3 and air entering from the network through channels 6 and 12 begins to flow through the throttle bypass channel 11 of the movable cover 10 into the battery emulation chamber 8, in which the air pressure is slightly lower than camera 3.

When the drummer 2 opens the exhaust channel 15 out of chamber 4, the exhaust air begins to exhaust, with a relatively quick decrease in its pressure to a value close to atmospheric. When the striker 2 moves, the air pressure in chamber 3 and chamber 8 communicated with it increases, causing the lid 9 to move from bottom 10 and more intensively fill the volume of chamber 8. As a result of changing cover 9, spring 22 in buffer chamber 21 is compressed to a calibrated position and the cover 9, braking, stops. The increasing air pressure in chamber 3, but as the impactor 2 moves, the bottom of the 10nrn interferes with a slight increase in the air pressure in the chamber 8, both by compressing its volume and by flowing air from chamber 3. chambers 8 and 3, drummer 2 slows down its movement and stops B in its design position when

the air pressure in chamber 8 is greater than in chamber 3. Thus, the braking of the striker 2 and the bottom 10 is carried out simultaneously with a greater amount of air and a higher pressure in the chambers 3 and 8 as compared with a moving accumulator chamber of constant volume, which causes a greater acceleration of acceleration of the striker 2 in the initial period of its working stroke, which begins immediately after stopping the striker 2 in the calculated position. In addition, the reduced backpressure of the air from the chamber 3 at the end of idling causes a greater stroke of the striker 2 and, consequently, more of its potential energy, which is converted into kinetic energy during the working stroke and provides an additional increase in the hammer's impact power. Also, the smaller and smoothly changing at the end of the idle (and the beginning of the working) stroke of the striker 2, the air pressure in chamber 3 and the corresponding effect of the pressure force through the cover 9, the spring 22, the cover 5 and the handle 20 provides a smaller required pressing force on the hammer, which improves the sanitary conditions of its operation.

As the striker 2 accelerates as it moves, the volume of chamber 3 increases, however, the air pressure in it is kept close to constant. This is caused initially by moving the bottom 10 after the striker 2, and then the lid 9, pushing some of the air from chamber 8 through the throttle bypass channel 11 into chamber 3 while simultaneously flowing into it the network air through the throttle channel 12 and its outlet 14.

Thus, a change in the volume of chamber 8 by moving the cover 9 allows the air pressure in chamber 3 to be maintained at a larger portion of the stroke of the striker 2 than with an accumulator chamber with a constant volume. This also predetermines the delay in reducing the force applied to the hammer and improves the sanitary conditions of the hammer.

Due to the mobility of the cover 9, there is a somewhat higher pressure in the chamber 8, and hence its greater potential for providing a higher average air pressure along the path of the impactor 2. This provides a greater increment in the kinetic energy of the impactor 2 and an additional increase in the impact power of the hammer. Consequently, the mobility of the blind cover 9 and the changeability of the volume of the accumulation chamber 8 provides, during the working stroke of the striker 2, without increasing the air flow rate from the network, more efficient accumulation and use of air, i.e. The process is carried out with an increased efficiency of using the energy of the compressed air of the accumulation chamber 8.

five

When the striker 2 closes the outlet channel 16 in the chamber 4, the process of compressing the air cut off in the chamber 4 and the air flowing into it through the channel 13 and the throttle channel 7 from the chamber 23 is injected. From the moment the drummer opens the channel 16, the camera 3 communicates with the camera 17 and through channels 18 in compartment 19 with the atmosphere. The pressure in the chamber 3 is reduced to a value close to atmospheric, and in the chamber 8 it is slower and the full release of air due to its throttling into the chamber 3 through the throttle bypass channel 11 does not occur. A part of the air in the chamber 8 is used in the next operating cycle of the hammer, which helps reduce air flow directly from the network. Overcoming air backpressure from

0 of chamber 4, the striker 2 strikes the tool 24 and this process repeats with the only difference that in the next idle pulse, a fraction of the rebound momentum of the striker 2 from the tool 24 is included.

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Claims (1)

PNEUMATIC HAMMER WITH THROTTLE AIR DISTRIBUTION according to author. St. No. 1285147, characterized in that, in order to improve the sanitary-technical characteristics of the hammer due to more smooth pressure control in the chambers, the cover and the bottom of the cylindrical hollow element in the central channel are placed with the possibility of movement relative to each other. Fig / SU _H1) 1321812