DE2825732A1 - COMPRESSED AIR IMPACT DEVICE - Google Patents

Description

Institut Gornogo DeIa Sibirskogo Otdelenia Akademii Nauk SSSR

Novosibirsk, USSR

Pneumatic impact device

The invention relates to a pneumatic impact device that z. B. for drilling holes in compacted soil, for driving pipes, of ground electrodes in the Ground as well as for driving in wooden or steel sheet piles.

It is a compressed air operated impact device z. B, known for hammer drilling holes in the ground (US-PS 3 727 701), which has a cylindrical hollow body in which a stepped impact head with a cavity in the Shaft part and an opening is arranged. A compressed air distributor is attached to a nut closing off the cavity attached, which is designed as a stepped nozzle, is rigidly attached to the nut by its shaft part. the The large front step of the nozzle is built into the cavity of the impact head.

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When compressed air is supplied, the impact head moves back and forth and strikes in its front Position on the hollow body, whereby the device is driven into the ground. The compressed air is constantly the fed to the rear working chamber, which is formed by the walls of the impact head and nozzle. For the return stroke of the With the impact head, compressed air flows into a reverse gear chamber through the opening in the impact head. Since that to the reverse gear chamber directed end face of the impact head larger than the end face directed towards the rear working chamber is, the impact head runs in the direction of the nut in its starting position.

Often after a standstill of the driving device downhole recommissioning is not carried out and pulling this device is an outcrop of the borehole is required, which is not always permissible. These deficiencies are particularly due to the imperfection of the Due to the air distributor against shock loads, hollow body deformation and pitting of the impact head is very sensitive in the hollow body.

Pneumatic impact devices are also known (US Pat. No. 3,410,354; DE-PS 1 634 579) which have a cylindrical hollow body with overhung impact head, a step valve, a flange, a tubular damper and have a mother. In these devices, the axial channel and radial channels located in the shaft part are supported Executed impact head against the inner walls of the hollow body via two projections and forms through its front part together with the walls of the hollow body, the chamber for supplying compressed air from the main line through the channels mentioned. The slide is an in the shaft part of the hollow body

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Orderly two-stage sleeve, which sits with its larger stage in the axial channel of the impact head and which the compressed air source connects with the radial channels, which are periodically closed by the slide when the impact head moves.

The sleeve is connected with its smaller step by the tubular damper with the flange, which is through a Nut is rigidly attached to the shaft part of the hollow body and has exhaust openings.

This design of the air distributor is complicated. Of the Slide often causes jamming of the impact head, but the damper is not reliable in impact mechanisms and not sufficiently durable, which means that the slide valve is often destroyed.

In another pneumatic impact device (SU Inventor's Certificate 496 350), the open end face is a cylindrical one Hollow body closed by a nut which has channels which open into its cylindrical inner surface. In the hollow body, a stepped impact head is overhung, which through its front part together with the walls of the hollow body forms the reverse gear chamber. The impact head has an axial channel and one connected to it Radial channel for supplying compressed air from the main line into the reverse gear chamber. On the surface of the large diameter step Longitudinal ducts are provided to the exhaust from the reverse gear chamber. The hollow body has a recess in the front part and an exhaust opening.

• The inner surface of the nut and the stepped impact head form a rear working chamber. The inner surface of the Hollow body, the face of the nut and the face

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the large step of the impact head form an annular space that is in communication with the outside air.

The disadvantage of this type of construction is the limited possibilities for increasing the blow performance, since the The face of the impact head is only partially used when it is passed.

The object of the invention is to provide a pneumatic impact device without creating the disadvantages mentioned, that is a higher impact performance, a more reliable air distribution and a greater strength of the hollow body against deformation and clamping, and in which the compressed air acts on the entire impact head face.

This task is performed with a pneumatic impact device a cylindrical hollow body closed on one side, in its open end face a threaded plug with flow channels sits, with a step-like impact head with longitudinal channels mounted overhung in the hollow body, its widened front part, together with the walls of the hollow body, a return chamber periodically acted upon by compressed air limited, with longitudinal channels on the surface of the widened front part of the impact head and with one of the outer surface of the narrower rear impact head part, the inner surface of the hollow body, the end faces of the nut of the front head part limited annulus, which is periodically in contact with the outside air, solved by the fact that * at least one radial opening is arranged on the section of the rear impact head part which cooperates with the nut is through which compressed air flows through the longitudinal channel into the nut of the annular space during the forward movement of the impact head.

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With this type of construction there is an increase in impact performance, since compressed air is applied to the entire cross-sectional area of the Impacts impact head.

To increase the operational reliability, it is useful in the wider front part of the impact head close to his in the back part of a ring recess into which the longitudinal channels of the front part to connect the return chamber open with the outside air.

It is also expedient to carry out an additional channel in the impact head, one end of which is in the cylindrical Surface of the front part and the other end of which opens into the face of the narrower rear part of the impact head, whereby openings in the rear part lead to the additional channel. This leads the exhaust air through the nut, whereby side openings in the hollow body are not required and the strength of the hollow body is increased. aside from that no protective housing needs to be used on the hollow body to protect the cavities against contamination.

The simplicity of the design is increased by the fact that the additional channels through a recess on the rear part are formed, which is covered on the outside by a fixed cylinder liner with openings.

In the following, exemplary embodiments of the invention are explained in more detail with reference to the drawing. Show it:

1 shows a longitudinal section of the pneumatic impact device;

FIG. 2 shows a section II-II in FIG. 1; FIG.

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Fig. 3 is a partial section of the shaft part of a device version in which the ring recess on the narrow step of the impact head is carried out at the outlet point of the radial opening;

Pig. U a longitudinal section of another compressed air impact device with an additional exhaust duct in the impact head;

5 shows a longitudinal section of another compressed air impact device with an additional channel in the form of a recess on the narrow step and a cylinder liner outside on this Step;

6 shows a section VI-VI in FIG. 5; FIG. 7 shows a section VII-VII in FIG. 5.

The pneumatic impact device according to FIGS. 1 and 2 contains a cylindrical hollow body 1 in which a step-like detached impact head 2 is housed. A nut 3 closes the open end face of the hollow body 1 and is connected to a main compressed air line 4. This main line 4 leads to the - not shown - compressed air source, z. B. to a ring main or a compressor.

The impact head 2 has two cylindrical steps coupled to one another, the diameter of which extends in the direction enlarge its front part. The impact head 2 limited with its wide front part together with the walls of the Hollow body 1 a return chamber 5 · The cylindrical surface of the narrower rear part of the impact head 2, the

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The face of the nut 3 and the face of the wider step of the hose head 2 form an annular space 6. The face the narrow impact head part 2 and the nut 3 delimit a rear working chamber 7, which is constantly connected to the main compressed air line 4 communicates.

In the side walls of the hollow body 1 exhaust air openings 8 are provided, which from the front end face of the Hollow body 1 are arranged at a distance that an exit of the exhaust air from the return chamber 5 in the rear End position of the impact head 2 guaranteed.

In the impact head 2, an axial channel 9 runs to a radial channel 10 for supplying compressed air from the rear working chamber 7 into the return chamber 5. The radial channel 10 opens into the cylindrical surface of the wide front part. A radial opening 11 is provided on the narrow rear part of the impact head 2. From the inside face of the nut 3 are longitudinal channels 12 which open into a recess 13.

As can be seen from Fig. 3, the recess 13 'can also be carried out on the stepped impact head, into which then the radial opening 11 'opens.

On the surface of the wider front part of the impact head 2, longitudinal channels 14 are provided, which open on the one hand into the return chamber 5 ' on the other hand into an annular groove 15 closer to the rear step of the impact head 2. The hollow body 1 has a recess 16 in its front part.

To secure the exhaust air through the front part of the impact device and to increase the strength of the hollow body 1 "is in the embodiment according to Fig. 4 in step-like

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gen impact head 2 "an additional bore channel 17 is carried out, one end in the cylindrical surface of the front stage and the other end opens into the cylindrical surface of the rear stage of the impact head 2 ". On the side of the rear chamber 7 ″, the additional channel 17 is closed by a screw plug 18. At the rear step of the impact head 2 ″ openings 19 and 20 are provided which are connected to the bore channel 17 stand. In the hollow body 1 ″ an annular groove 21 is made approximately in its central part. In the nut 3 ″ there is a Exhaust duct 22 running in the outer face of the nut 3 "and with its other end in its cylindrical Surface opens, which cooperates with the narrow rear step of the impact head 2 ".

According to Fig. 5, to simplify the design and to reduce the friction between the surfaces of the narrow step of the ^{impact head 2 IIT} and the nut 3 ^flf, the additional channel 17 ^llf in the ^{impact head 2 tfl can be designed} as a recess on the narrow step _s with outside this recess 23 on the narrow step of the impact head 2 ^'11 a cylinder liner 24 is attached, which one with the radial opening 11' ^t! In the ^{impact head 2 MI} coinciding inlet opening 25 for the inlet of the compressed air into the annular space 6 '''and exhaust air openings 26 (Fig. 5, 7) and 27 which ^{open into the additional channel 17'"of the impact} head 2 1Tt and the exhaust air from the Reverse gear chamber 5 '''and ^{discharge from the annular space 6 1} ''.

The operation of the described pneumatic impact devices is as follows:

Compressed air is from the main line 4 (Fig. 1) in the

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The rear working chamber 7 is introduced and passes through the axial channel 9 and the radial channel 10 into the return chamber 5. As a result of the difference in the end faces of the two stages of the impact head 2, the impact head begins to move in the direction of the nut 3. During its movement, the radial channel 10 is closed by the inner surface of the hollow body 1 and its further movement occurs through expansion of the compressed air in the return chamber 5. At the end of the stroke of the impact head 2, its annular recess 15 coincides with the openings 8 in the side walls of the hollow body 1, whereby the return chamber 5 comes into connection with the opening 8 of the hollow body 1 through the longitudinal channel IM in the front head part. The compressed air flows out of the return chamber 5 through the longitudinal channel 14 and the opening 8 to the outside.

At the end of the stroke of the impact head 2, the radial opening 11 in the rear head part sweeps over the annular groove 13 in the nut 3. The compressed air flows out of the axial channel 9 through the radial opening 11, the annular groove 13 and the longitudinal channels 12 in the nut 3 in the annular space 6. Thus, compressed air acts on the entire end face of impact head 2. Under the action of the compressed air present in the rear working chamber 7 and in the annular space β the impact head 2 is braked and begins to move forward. At the target distance from the start of movement of the impact head 2 its radial opening 11 through the inner surface of the nut 3 and also the annular groove 13 in the nut 3 through the surface of the narrow rear head part is closed. The further movement of the impact head 2 takes place through the energy of the expanding air in the annular space 6 and the air pressure in the rear working chamber 7. At the end of the percussion stroke shown in Fig. 1, the percussion head 2 strikes against the front end wall of the hollow body 1. The impact head opens 2 the openings 8 in the side walls of the hollow body 1

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and the exhaust air flows out of the annular space 6 to the outside. The radial channel 10 in the impact head 2 opens into the recess 16 in the front part of the hollow body 1 and connects the return chamber 5 with the rear working chamber 7. The compressed air flows from the main line 4 into the rear working chamber 7 and through the axial channel 9 and radial channel 10 of the step-like Striking head ? into the retrieval chamber 5. In the further course, see the work cycle repeated.

The annular groove 13 in the nut 3 (Fig. D ₃ the annular groove (Fig. 5) in the rear partial head part and the annular groove 15 (Fig. 1) in the front wide head part are necessary so that when the impact head 2 and 2 ^{! 1f rotates} around the longitudinal axis of the compressed air inlet into the annular space 6 and 6 '''and the outflow of the exhaust air from the return chamber 5 and 5 ^{! Tt} to the outside are not interrupted.

In the embodiment according to FIG. H , the operation takes place in a similar manner with the exception that the compressed air outlet from the return chamber 5 "and from the annular space 6" takes place through the rear face of the device, the air through the additional duct 17 and the exhaust ducts 22 in the nut 2 ″ flows off.

In the position shown in FIG. K , the compressed air flows through the axial channel 9 "and the radial channel 10" of the impact head 2 "into the return chamber 5" Impact head 2 "and through the outlet channel 22 in the nut 3" in connection with the outside air.

The compressed air acts on the face of the narrower head part, which loads the rear working chamber 7 "

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borders, and at the same time on the face of the wider head part, which delimits the return chamber 5 ".

As a result of the difference between the two end faces, the impact head 2 "begins to move in the direction of the nut 3" to move. When it moves, the opening 19 sweeps over the annular groove 13 ″ in the nut 3 ″ and the longitudinal channel 1 * 1 ″ in the The front head part runs into the recess 21 of the hollow body 1 ″. The additional Channel 17. The compressed air flows from the return chamber 5 "through the longitudinal channel 14", the recess 21 of the hollow body 1 ", the additional channel 17 and the opening 20 in the impact head 2" and through the outlet channel 22 in the nut 3 " Outside.

At the same time, the radial opening of the impact head 2 "coincides with the annular groove 13" in the nut 3 "and the Compressed air flows from the rear working chamber 7 ″ through the axial channel 9 ″, the opening 11 ″ of the impact head 2 ″, the annular groove 13 "and through the inlet channel 12" of the nut 3 "into the annular space 6". Under the action of compressed air in the rear Working chamber 7 ″ and in the annular space 6 ″, the impact head 2 ″ is braked and begins until the impact is exerted to move forward against the hollow body 1 ".

At the end of the stroke of the impact head 2 ″, its opening 20 falls with the inlet opening of the channel 22 together, so that the compressed air from the annular space 6 "through the opening 19, the additional channel 17, the opening 20 in the impact head 2 "and through the outlet channel 22 in the nut 3" flows to the outside.

The compressed air is then fed to the return chamber 5 "and the work cycle is repeated.

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This design enables the use of a hollow body 1 "without side openings, which increases its strength is increased. In addition, a protective housing can be placed on the hollow body 1 ″ to protect the cavities of the impact head 2 ″ against No pollution, which increases operational reliability.

In the embodiment according to FIGS. 5 to 7, the operation is similar to that of FIG. 4. The outlet of the exhaust air from the annular space 6 '"to the outside takes place through the opening 26 in the socket 24, the additional channel 17"'between the walls of the impact head 2' ^f 'and the cylinder liner 24, through the opening 27 of the cylinder liner 24 and through the outlet channel 22'"in the nut 3 ^tTI . The outlet from the return chamber 5 '"to the outside takes place through the longitudinal channel 14" of the impact head 2'", the recess 21 in the hollow body 1"', the additional channel 17 "', the opening 26 in the cylinder liner 24 and through the outlet channel 22 "in mother 3"'.

The inlet of pressurized air into the annular space 6 '''is carried out from the rear working chamber ^{7! Tt} through the axial channel 9'"and the opening II ^{1 '1,} the inlet port 25 of the cylinder liner 24, the annular groove 13''and through the inlet channel 12 "'in mother 3'" ·

Such a design can simplify the design.

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-hS-

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Claims (3)

Expectations Compressed air impact device with a cylindrical hollow body closed on one side, in its open end face Threaded plug with flow channels sits, with a step-like impact head mounted overhung in the hollow body Longitudinal channels, the widened front part of which together with the walls of the hollow body are periodically filled with compressed air acted return chamber limited, with longitudinal channels on the surface of the widened front part of the impact head and with one of the outer surface of the narrower rear impact head part, the inner surface of the hollow body, the end faces of the nut of the front head part bounded annulus, which is periodically in connection with the outside air stands, characterized, that on the section of the rear impact head part cooperating with the nut (3) at least one radial opening (11) is arranged through which during the forward movement of the impact head (2) compressed air via the longitudinal channel (12) into the Nut (3) flows towards the annular space (6). 2. Compressed air impact device according to claim 1, characterized in that 530- (P 70.OO2-M-6I) -SdE 9098SÖ / Q485 that on the front part of the impact head (2) near its rear part an annular groove (15) is made over which the longitudinal channels (14) in the front head part periodically connect the return chamber (5) with the outside air. 3. Compressed air impact device according to claim 1 or 2, characterized in that that in the impact head (2) an additional channel (17) is carried out, one end of which into the cylindrical face of the front head part and the other end opens into the cylindrical surface of the rear head part, and that in the rear narrow head part openings (19, 20) are provided which are directed towards the additional channel (17) are. H. Compressed air whip device according to claim 3 _S, characterized in that that the additional channel (17 ' ¹ ') is formed by a recess (23) made on the rear head part, which is covered by a cylinder liner (24) with inlet and outlet openings (26, 27). 909850/0485