SU1333747A1 - Reversible pneumatic percussive device - Google Patents

Description

The invention relates to construction equipment and is intended for percussion devices used, for example, for punching a well in the ground during trenchless laying of underground utilities. . . A pneumatic reversing device is known, comprising a cylindrical body, a drummer with a window and a cavity in the tail section, into a distributor with a thread and a nut with channels.

A disadvantage of this device is inconvenience in operation and the duration of the process of switching from one mode of operation of the device to another. In order to avoid spontaneous switching, the machines from one mode of operation to another increase the number of revolutions necessary for reversing (in serial machines 10-14 revolutions).

For reversing it is necessary to turn off the compressed air supply, disconnect the air supply hoses and rotate the hose to ensure that the nozzle is rotated 10-14 turns, which is not always possible with long wells. All this leads to an increase in the duration of the switching process from one mode of operation to another.

The closest in technical essence is a pneumatic reversing percussion device comprising a body, a hammer with a window, and a cavity in the tail time.

TI, which forms with the front working chamber, a stepped nozzle fixed in the rear part of the body, forming with the drummer a rear working chamber having a protrusion that interacts with the body lugs, and a shock absorber with channels.

The disadvantages of this device are the low durability of the striker and the casing, which are weakened respectively by the longitudinal groove and height, the productivity is low, since it is necessary to reduce the impact energy so that the voltage in the attenuated impactor does not become acceptable, unreliable operation of the device, possibly jamming a projectile with a protrusion, the entrance w 1m into the groove of the projectile due, for example, to the penetration of the ground between the groove and the protrusion.

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The purpose of the invention is to increase the impact energy and reliability of operation — in a pneumatic reversing percussion device comprising a housing, a drummer with a window and a cavity in the tail section, forming a front working chamber with the housing, a step nozzle attached to the rear section of the housing. forming a back working chamber with a drummer, having a protrusion, interacts; with lugs of the body, and a shock absorber with channels, the impactor cavity and the nozzle are located eccentrically relative to the longitudinal axis of the device, with a large step of the nozzle made with a slot.

The front part of the impactor is made eccentrically relative to the longitudinal axis of the device, and the masses of the parts of the impactor, located symmetrically relative to the longitudinal axis of the device, are equal to each other.

In addition, between the front end of the striker and the cavity is made of a flat face, and the masses of the parts of the striker, located symmetrically relative to the longitudinal axis of the device, are equal to each other.

FIG. 1 shows a device, a longitudinal section i in FIG. 2, a device with an eccentric front part of the striker; FIG. 3 is a section A-A in FIG. 2; in fig. 4 is a section BB in FIG. 2; Fig, 5 is a section b-B in Fig.2; figure 6 - the device with flat, placed in the middle part of the drummer; in fig. 7 is a cross-section of the FIG. 6; in fig. 8 - device with assiyetrichny air distribution edges of the nozzle.

The pneumatic reversing device consists of a body 1, a drummer 2 with a window 3 and a cavity 4 in the tail section. In the cavity 4 of the striker 2 is placed the pipe 5, which has two stages. In a step with a larger diameter of the nozzle 5, a slot 6 is made, which is located below the longitudinal axis of its symmetry. The nozzle 5 is rotatable around its longitudinal axis of symmetry, fixed, in the tail part of the housing 1 and its larger diameter step is installed in the tail cavity 4 of the striker 2, which is made offset from the longitudinal axis of the device (eccentricity e is shown in Fig. 1).

The housing 1 together with the drummer 2 forms the chamber 7 of the reverse stroke of the drummer 2. Together with the socket 5, the drummer 2 forms the chamber 8 of the forward stroke of the drummer 2. Together the housing 1, the drummer 2 and the socket 5 form the exhaust chamber 9. The socket 5 is fastened to housing 1 by means of a shock absorber 10 having channels 11 for exhausting compressed air from chamber 9 to the atmosphere. The shock absorber 10 has stops 12, - interacting with the protrusion 13 of the nozzle 5, limiting the rotation of the nozzle 5 (Fig. 3).

In the drummer 2, the front part 14 can be made eccentrically relative to the longitudinal axis of the device (FIG. 2), or the flat face 15 (FIG. 6) is located in the middle part of the drummer 2, with the masses of the parts of the drummer located symmetrically relative to the longitudinal axis of the device equal to each other.

The nozzle 5 is made with a slot 6 with the distance between the ends 16 and 17 of the nozzle 5 (Fig. 2) determining the moment of admission of compressed air from chamber 8 to chamber 7 and exhaust of compressed air from chamber 7 to chamber 9 when operating in pr mode. The device’s travel may be equal (FIG. 8) or large (FIGS. 1, 2 and 6) the distance between the ends 18 and 19 of the nozzle 5 determining the moment of intake of compressed air and its exhaust from chamber 7 in the operating mode of the device on the reverse go. .

YcTpofic.TBo works as follows.

Forward travel of the device. When compressed air is supplied to the chamber 8 of the forward stroke of the striker 2, the latter moves forward, striking in its front position a blow on the front of the housing 1 (the position is shown in Fig. 1). After passing through the window 3 of the striker 2 of the front end edge 16 (Fig. 2) of the pipe 5, the compressed air from the chamber 8 through the window 3 of the striker 2 enters the chamber 7 of the return stroke of the striker 2. Due to the fact that the area of the striker 2 from the side of the camera 7 more than the area of the striker 2 from the side of chamber 8, the striker 2 begins to move towards the tail section due to expansion of compressed air in chamber 7. After passing through the window 3 of the striker 2, the trailing edge 17

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(Fig. 2) of the pipe 5, the compressed air from the chamber 7 through the window 3 of the striker 2 enters the chamber 9 and from there through the channel 11 of the shock absorber 10 is released into the atmosphere. Due to the pressure of the compressed air in the chamber 8, the striker 2 moves forward and the cycle repeats.

Due to the fact that the cavity 4 of the striker 2 is displaced relative to the longitudinal axis of the striker, 2. (by the value of eccentricity e) and the nozzle 5 is installed in it, the striker 2 is fixed against rotation relative to the housing 1, therefore in the forward stroke mode the window 3 of the striker 2 only interacts with the edges 16 and 17 of the nozzle 5 located above the axis of symmetry of the nozzle 5 ..

In order to exclude the transfer of the component of the shock pulse arising due to the asymmetry of the ma- chine of the striker 2 with respect to its longitudinal axis, there are two options.

Balancing the mass of the striker 2 by performing: a) the front part 14 of the striker is eccentric relative to the longitudinal axis (Fig. 2) of the device; b) the flats 15 (Fig. 6), placed in the middle part of the drummer 2.

When using the options of FIG. 2 and 6, the mass distribution of the impactor 2 with respect to its longitudinal axis becomes symmetric, i.e. how eccentric the cavity 4 reduces the mass of the striker 2, which lies below its longitudinal axis, so much the lip 15 (eccentric surface 14) reduces its mass, which lies above its longitudinal axis. By virtue of this, a shock occurs on the axis of symmetry of the shock mass of the impactor 2. As a result, the impact does not produce a transverse component of the shock pulse.

When using the nozzle 5 with asymmetrical air distribution end edges (Fig. 1, 2, 6), during the forward running, the edges 16 and 17 interact with the window 3 of the impactor 2. Slot 6 (and therefore the end 18 of the nozzle 5) in the air distribution is not is involved.

Reverse the device.

To switch to reverse, you need to turn the nozzle 5 to 180. In this case, the end edges 18 and 19 of nozzle 5, which were located below the longitudinal axis, interact with the window 3 of the striker 2 (they will now occupy a position above the longitudinal axis of the nozzle 5). .

When compressed air is supplied to chamber 8, the striker 2 moves forward and after passing through the window 3 of the striker 2 of the end edge 18 of the nozzle 5, the compressed air through the slot 6 of the nozzle 5, the window 3 of the striker 2 enters the chamber 7, as the edge 18 of the nozzle 5 is located closer to the tail part of the housing 1, the compressed air inlet into the chamber 7 of the reverse stroke of the striker 2 occurs earlier than during the forward movement of the device. By virtue of this, the impactor 2 will stop by compressed air in the chamber, 7, earlier and yj3, apa on the front, part of housing 1 will not occur.

Under the action of compressed air, which is located in chamber 7, the drummer 2 moves backward until it hits the tail section of the housing 1. The stroke of the impactor 2 back will be longer due to the large volume of chamber 7 (there will be a more intense blockage of the impactor 2), shown in FIG. 1, 2, 6, or at the expense of a later exhaust (Fig. 8). After striking the tail of the hull 1, the drummer 2

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go ahead, as described above. The cycle is repeated.

When using the designs shown in FIG. 1, 2 and 6, in which the pipe 5 is made with an appropriately defined air distribution ends, i.e. the distance between the ends 16 and 17, which control the movement of the striker 2 during forward travel, is longer than the distance between the ends 18 and 19, and the control of the SD-1MI movement of the impactor 2 during reverse-travel, the length of the slit 6 is such; so that the time of intake of compressed air through the slot would ensure that chamber 8 is filled with compressed air to prevent impactor 2 from striking the front of housing 1.

However, in high-frequency devices, when the length of the larger step of the nozzle 5 is small, the use of such a construction is excluded (and sometimes not possible), since the required length of the notch 6 can be commensurate with the 5 length of the nozzle, so you can use the design shown in FIG. 8. This design allows the distance between the edges 18 and 19 to be lengthened. It should be noted that in this case the housing 1 must be lengthened.

The use of the invention will improve the impact energy and the reliability of the impact device.

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Claims (3)

1. PNEUMATIC REVERSE IMPACT DEVICE, comprising a housing, a firing pin with a window and 1 ^ ol |> t in the rear part, forming a front working chamber with a housing, a stepped pipe fixed in the rear part of the housing, forming a rear working chamber with a projection having a protrusion having a protrusion interacting with the stops of the body, and a shock absorber with channels, characterized in that, in order to increase the impact energy and reliability, the cavity of the hammer and the pipe are eccentric relative to the longitudinal axis of the device, and stage nozzle is formed with a slot. 2. The device pop. ^ characterized in that the front part of the striker is made eccentrically relative to the longitudinal axis of the device, and the mass-parts of the striker located symmetrically relative to the longitudinal axis of the device are equal to each other. 3. The device pop. 1 l of m and _- sistent in that between pe- ® Independent user end and the striker cavity formed Lyska, wherein the impactor mass parts, disposed symmetrically relative to the longitudinal axis of the device, are equal. SU. „, 1333747