EP1951984A1

EP1951984A1 - Hammer drilling device with a pneumatic reversing gear

Info

Publication number: EP1951984A1
Application number: EP06724205A
Authority: EP
Inventors: Franz-Josef Püttmann; Gerhard Balve
Original assignee: Tracto Technik GmbH and Co KG
Current assignee: Tracto Technik GmbH and Co KG
Priority date: 2005-11-16
Filing date: 2006-04-10
Publication date: 2008-08-06
Also published as: WO2007057055A1; CN101310088A; US7874382B2; AU2006314836A1; CN101310088B; AU2006314836B2; US20080257609A1

Abstract

The invention relates to a hammer drilling device with a pneumatic reversing gear. Said device comprises a hammer piston (8) that is situated in a housing (1) and is displaced back and forth with the aid of air supplied via an air conduit (5), a control pipe (4, 36, 54) comprising at least one control opening (13), an outer pipe (15, 65) and a control sleeve (10, 60) that can be displaced by compressed air from a control chamber (16, 66). In said device, an essentially torsion-resistant air conduit (5) can be rotatably connected to a rotary valve (4, 40, 70) that supplies the control chamber with air or evacuates air from said chamber.

Description

"Rammbohrqerät with pneumatic reversal"

The invention relates to a ram boring machine with pneumatic reversal, in particular for trenchless production of earth boreholes and trenchless laying of pipes in the ground.

Such Rammbohrgeräte also serve to widen the earth drilling and destructive replacement of buried pipes; they have a reciprocating in a housing by means of compressed air and self-steering percussion piston, which transmits its kinetic energy in forward operation in a front dead center and in reverse operation in a rear dead center on the housing.

The switching from forward to reverse operation is done by means of a reversal, which causes a braking of the percussion piston in its front dead center substantially without transmission of kinetic energy to the housing by means of the working air and a rearward displacement of the rear dead center and ensures that the percussion piston its kinetic Energy there to the housing gives.

Such reversals are known in numerous versions, they use a compressed air on the one hand and often by means of a prestressed compression spring on the other hand axially displaceable on a sliding fixed in the device housing control tube displaceable control box for adjusting the two dead center. In this case, the reversals essentially follow two constructive development lines, which in principle differ from each other in that they use different sources for the origin of the control sleeve acting upon switching compressed air.

Thus, for example, in a reversal known from British Patent 1 540 344 or the corresponding US Pat. No. 4,708,211, the working air (compressed air) fed to the percussion piston via a compressed air hose and a non-rotatable and non-displaceable control tube is used for longitudinal displacement of a control sleeve

BESTATlGUNGSKGPiE Switching from forward to reverse. The switching from reverse to forward running is done in such a way that the supply of the device is interrupted with working air, so that the spring-loaded control sleeve can move from its rearward position to its forward position.

A known from the German Patent DE 39 09 567 C2 and the corresponding US Patent 5,148,878 known spring-pneumatic reversing uses reversing a reverse by means of the compressed air hose rotatably arranged in a guide sleeve spring-loaded control sleeve for reversing from forward to reverse a below Spring tensioned control box. It is the

Spring tension such that the control sleeve in its full application to the working air overcomes the spring bias and moves the control sleeve from its forward forward forward position to its rearward reverse position. To switch from reverse to forward running a reduction of the compression spring counteracting pressure of the working air is required, it is the

Compression spring allows to move the control sleeve to its front position. In both positions, the control sleeve is rotated under the influence of elastic means about its longitudinal axis and locked in the axial direction.

A disadvantage of this spring-pneumatic reversers is that they require a relatively high constructive or technical effort and that the use of working air from a single source both for the operation of the percussion piston and for reversing a shutdown of the working air and thus an interruption device operation requires or in the case of Druckverminde- tion during switching only a reduced device performance is available.

On the other hand, ram boring devices are also known which permit the switching of the control bushing independently of the working air, which use control air from a separate compressed air source for the axial adjustment of a spring-loaded control bush. Such a device describes the German patent DE 198 58 519 C2 or the corresponding US Pat. No. 6,371,220.

The invention is therefore directed to a Rammbohrgerät that requires a relatively small design effort for the reversal and in particular the

Avoidance of an additional control air source allowed.

The invention is based on the idea to control with the working air itself instead of an additional air source, regardless of how the specific implementation is done technically. To achieve this, the invention in claim 1 proposes a pneumatic reversal before, in which the control box is adjusted by means of a valve by means of working air.

The valve can be designed technically arbitrary and is in its simplest form as a closable hole in the head tube. The valve (in the following rotary valve) is inventively connected to a torsionally rigid hose for the working air; Preferably, it can supply the control chamber of the control box with working air in its end position for the reverse rotation and vent after rotation through, for example, 90 ° in the end position for forward rotation of the control chamber. The rotary valve allows in this way an axial displacement of the control sleeve under the influence of the working air. For the provision of the tax box but also a preloaded spring can be used.

The rotary valve can consist of a rotatably mounted control tube or part of the control tube with a radial branch bore and a longitudinal channel. In this case, the radial branch bore in the one end position of the control tube or control tube part can be in operative connection with a working air opening of the control chamber while the control tube is turned back into the other end position and the radial bore is closed and the control chamber is connected to the longitudinal channel for venting can be. Alternatively, the venting can be done for example via the relaxation space of the percussion piston.

Between the rear end of the control tube and a connecting sleeve for the working air hose can be located under the pressure of the working air, for example, several of the locking of the control tube in the two end

Parts existing pressure chamber are located in the preferably a compression spring is arranged, which replaces the working air in the event of a business interruption or a non-pressurized state and thus maintains the lock. In order to create a permanent rotational connection between the control tube and the connecting sleeve, the connecting sleeve of the pressure chamber can engage the front side of the claw in the control tube.

To lock the control tube in its two end positions, a housing-fixed counter sleeve with saddle-shaped depressions and elevations in their end face and under the influence of the pressure of the working air in the pressure chamber and / or the pressure spring arranged therein with a pin which communicates with the head tube , collaborate. The pin can also be provided on the housing side and the depressions control tube side.

In the rotary valve control according to the invention, however, the control tube can also be arranged rotatably and non-displaceably in the device housing. In one case, the

Control chamber of the spring loaded tax box then from one in the rear part of the housing arranged on the control tube tubular rotary valve via a radial branch bore for working air and a radial passage in a control disc supplied with working air or vented in its other end position with closed radial passage via an axially parallel bore.

The rotary valve may consist of a metallic disc and a lining of a permanently elastic material, which has the two aforementioned channels.

An advantage of this control is that the spring-loaded control sleeve by a mere rotation - in the simplest case of the head tube - with a within the

Device branched partial flow of the working air is moved from its flow position to its return position.

In another preferred embodiment, the axial displacement of the control sleeve under the influence of the working air without spring, i. to realize in both directions. For this purpose, the control box can be designed so that the control box is moved under the pressure of the working air in the one functional position (for example, by acting on the end face of the control sleeve drive air in the position for reverse rotation), while the connection of working air via another channel the control box moves back to the other functional position. This can be achieved by the switchable working air acts on a structurally relatively larger effective area of the control box. As a result, overcomes the control box by means of the supplied working air, the lower force acting in the opposite direction, which emanates from the supplied from the opposite side working air pressure. In this embodiment, the rotary valve as an independent unit or as part of the control tube allow a connection of the working air via an arbitrarily equipped closable opening, so that this working air counteracts the effective direction of the impact piston side air supply. Thus, the working air acting on the end surface of the control sleeve can lead to a rearward displacement of the control sleeve, while the control sleeve is moved back to the flow position with a connection of working air through the closable opening.

According to the invention, an axial displacement of the hose during reversal can be largely avoided. This allows the reversal of the invention also for large hose diameters or long hose lengths, i. to use at high hose weight, without this being hindered by the Umsteuern.

The invention will be explained with reference to exemplary embodiments illustrated in the drawing of the details. In the drawing show: 1 shows the overall view of a Rammbohrgeräts, in which the control tube serves as a rotary valve, in an axial longitudinal section,

2 a / 2 b show an enlarged view of the device (control bush side 2 a, rearward end 2 b) with the spring-loaded control bushing and a rear locking in the preliminary position,

3 is a vertical section along the line IH-III in Fig. 2,

Fig. 4a / 4b a Fig. 2 corresponding representation, but with the head tube and the control sleeve in its return position,

5 is a representation corresponding to FIG. 3, but along the line V-V in FIG. 4 with the control tube and the control sleeve in their return positions, FIG.

6 is an enlarged view of the rear end of the ram boring machine according to FIGS. 2 to 5,

7 is a longitudinal section along the line VII-VII in Fig. 6,

8 shows a cross section along the line VIII-VIII in Fig. 6,

9a / 9b show another rotary slide control (control bushing side 9a, rear end 9b) with a rotary valve arranged in the rear part of the device housing in its position for forward movement,

10 is a plan view of a control disk of the rotation control of FIG. 12,

FIG. 11 shows the rotary valve control according to FIG. 9 in its return position, FIG.

Fig. 12 shows a further rotary valve control with a in the rear part of the

Device housing arranged rotary valve in its position for the

Reverse.

Fig. 13 shows a further rotary valve control with a in the rear part of the

Device housing arranged rotary valve in its position for the reverse and with a control box without spring loading,

FIG. 14 shows the rotary valve control according to FIG. 13 in its position for forward running, FIG. FIG. 15 is an enlarged view of the front end of the rotary valve controller of FIG. 13; FIG.

Fig. 16 is an enlarged view of the rear end of the rotary valve control of Fig.13 and

Fig. 17, the rotary valve control of FIG. 13 in its position for forward rotation and representation of the ventilation paths.

The Rammbohrgerät consists of FIG. 1 of a housing 1, in the interior of a stop ring 2 is arranged with axially parallel exhaust air ducts 3. In the housing 1, a control tube 4 is mounted non-displaceable, which is supplied via a torsionally rigid tube 5 with working air. The front end of the control tube 4 protrudes into a chamber 7 provided with control openings 6 of a percussion piston eighth

There is an axially displaceable control sleeve 10, which is slidably mounted on the larger diameter portion 11 of the control tube 4 between the head tube 4 and the jacket 9 of the percussion piston chamber 7. At the front end of the control tube 4 or the larger diameter control tube part 11 is an outer collar 12, which covers the front end surface of the control sleeve 10 and flush with the control sleeve 10 (Fig. 2a). Furthermore, in the larger diameter front part 11 of the control tube 4 control openings 13 are arranged, which are covered during the forward operation of the ram boring, as shown in FIGS. 2, 3, of the control sleeve 10. In the rear part of the control sleeve 10 is an inner collar 14, with which the control sleeve 10 is guided on an outer tube 15 surrounding the control tube 4. Between the inner collar 14 and the back of the larger diameter control tube part 11 is a control chamber 16 into which a connecting channel 17 opens. The connecting channel 17 is radially inwardly offset to a longitudinal channel 18 at. The channel 18 consists of a longitudinal groove 19 in the wall of the head tube 4, which is covered to the outside by the outer tube 15.

The control sleeve 10 is supported via a prestressed return spring 20 in the region of the rear end of the outer tube 15 and is in its forward position (Fig. 2, 3) with its inner collar 14 on the back 16 of the larger diameter control tube part 11 and in its return position (Fig 4, 5) with its rear end 21 in front of a stop shoulder 22 of the outer tube 15th

The control tube 4 has a branch opening 23, which is closed by the wall of the outer tube 15 during forward movement (FIGS. 2, 3) (FIG Control chamber 16 via the longitudinal channel 18 connected to the atmosphere, that is vented (Fig. 2).

In the operating position for the reverse (Figure 4, 5), the branch opening 23 of the control tube 4 is after a 90 ° rotation over the front radially outwardly offset part of the connecting channel 17 in connection with the control chamber 16 (Fig the longitudinal channel 18 is closed by a shoulder 24 of the control tube in conjunction with the outer tube 15 (Fig. 5). The consequence of this is that the control sleeve 12 moves backwards from its forward position (FIGS. 2, 3) against the pressure of the prestressed spring 20 into its position for reverse (FIGS. 4, 5).

A change in the working direction of the ram boring machine is therefore possible by means of a simple quarter turn of the function of a rotary valve taking over control tube in one or the other direction.

In order to lock the control tube 4 in each of the two operating positions, located between the rear end of the control tube 4 and a ferrule 25 for the working air hose 5 is a two-part pressure chamber 26 in which a compression spring 27 is arranged. Both the rear end of the head tube 4 and the front end of the ferrule 25 is in a tubular extension

28 of the outer tube 15 is arranged. The front side of this extension is provided with saddle-shaped depressions, which cooperate with complementary elevations 30 of a counter sleeve 32 held by means of a union nut 31. The union nut is screwed to the free end of the housing extension so that they the connection sleeve 25 under the influence of the working air in the pressure chamber 26 and the

Compression spring 27 or in the pressureless state of the device alone under the action of the compression spring 27 in the counter sleeve 32 can move axially slightly out of the device housing.

The locking of the control tube works in such a way that a pin 33 moves out of its at a rotation of the working air hose 5 with the ferrule 25 by 90 ° from a recess 29a of the counter sleeve 32 until the pin 33 from its position shown in Fig. 8 meets an exposed stop surface 34 and engages over the lying between the depressions 30 survey away in one of the stop surface 34 and the other operating position associated, not visible in the illustration of FIG. 7 depression 29b.

In the embodiment shown in FIGS. 9 to 11, a conventional control tube 36 is arranged rotationally and non-displaceably in the device housing 1. The control tube 36 is provided with a longitudinal channel 37, which opens directly into the control chamber 16 at 38. In the region of the rear end of the control tube 36 is a rotary valve 40 with a branch hole 39 is provided. The rotary valve 40, has a connecting sleeve 41 for the working air hose 5 and a control disk 42 with a permanently elastic coating 43. The control disk 42 is integrally connected to the connecting sleeve 41, and presses the lining 43 under the influence of the working air located in a pressure chamber 44 sealingly against the rear wall of the protective housing. 1

The longitudinal channel 37 continues with different cross-section and varying course on the interior of the unit up to a two-piece exhaust duct. This exhaust duct consists of an L-shaped recess 45 in the elastic pad 43 and an aligned in the slide position for the forward run exhaust hole 46 in the

Rear housing wall (Fig. 9b).

The exhaust air bore 46 shown in FIG. 9b is in reality arranged at an angle of rotation of 90 ° with respect to the mouth of the longitudinal channel 37 in front of the rear wall of the housing and is in the operating position for forward rotation via a groove 48 in the lining 43 (FIG. Fig. 10) with the longitudinal channel in connection.

Furthermore, one of the pad 43 of the control disk 42 penetrating working air duct 50 connects the branch bore 39 in the operating position for the reverse run with the rear, approximately U-shaped end of the longitudinal channel 37 (FIG.

11). Accordingly, the control chamber 16 is acted upon by the control tube 36 from working air and moves the control sleeve 10 from the operating position shown in Fig. 9 in its rear operating position shown in FIG. 11th

The embodiment of FIG. 12 differs from the embodiment of FIGS. 9 and 11 only in that the branch bore 39 is omitted and the control chamber 16 is supplied with working air from the pressure chamber 35. This is done via a control disk 42 and the pad 43 penetrating axially parallel bore 51 which is aligned in the rotary valve position for the reverse run with the open end of the longitudinal channel (Fig. 12).

The pressure causes in the embodiments of Figures 9 and 12, a friction-related fixation of the control disk in their respective position. In the operating position for the forward run, the control chamber 16 is vented, as shown in Fig. 9 for the other rotary valve variant.

In the embodiment of FIGS. 13 to 17, a rotary valve control is shown in which the control tube 54 is fixed against displacement and rotationally fixed in the device housing via an L-shaped bolt 74, while the rear region of the control tube has a rotary valve 70. A control sleeve 60 is on the front part of the head tube with its inner collar 60a on a slip ring 61 and on an outer collar 65a of the outer tube 65 surrounding the control tube 54 and slidable in both directions by means of working air. Between the inner collar 60a and an outer collar 65a is a control chamber 66, into which a longitudinal channel 68 opens. The channel 68 consists of a longitudinal groove 69 in the wall of the control tube 54, which is covered to the outside by the outer tube 65.

In the region of the rear end of the control tube 54, the rotary valve 70 is provided with a branch bore 79. The branch bore 79 is closed by the wall of the control tube 54 during reverse rotation (FIG. 13), while the control chamber 66 is connected to the atmosphere via the longitudinal channel 68 and a vent channel 69a with vent holes 69b, 69c, d. H. is vented.

For the operating position for the forward run (FIGS. 14, 15), the branch opening 79 of the rotary valve 70 is brought into contact with the control chamber 66 by means of a 90 ° rotation via the longitudinal channel 68 (FIG. 14).

The active surfaces within the control chamber 66, to which the operating air supplied via the longitudinal channel 68, are dimensioned in relation to the active surfaces on the end face 62 of the control sleeve 60 so that the prevailing in the control chamber 66 and in the region of the end face 62 same working air pressure leads to a displacement of the control sleeve 60 in the direction of the sliding ring 61 and thus in the operating position for the forward run. The control sleeve 60 abuts with its inner collar 60a (FIGS. 14, 15, 17) on the rear side 61a of the sliding ring 61, while it moves to the outer collar 65a of the outer tube 65 when switching to the return position (FIG.

The result of a simple 90 ° rotation of the working air hose is therefore that the control sleeve 60 from its return position (Fig. 13) against the pressure of acting on the end face 62 of the control sleeve 60 working air forward to its forward position (FIG , 15, 17), while, after a rotation back of the working air hose by 90 ° due to the force acting on the end face 62 of the control sleeve 60 working air pressure, ie when the control chamber 66 is vented, moved back to the operating position for the reverse.

Thus, a reversal of the device is possible only by means of working air pressure and with the help of a simple quarter turn of the rotary valve in one or the other direction.

Claims

claims:

1. Rammbohrgerät with pneumatic reversing with a in a housing (1) by means of a working air line (5) supplied working air reciprocating blow piston (8), a control tube (4) with at least one control port (13), a Outer tube (15; 65), a control sleeve (10; 60) displaceable by compressed air actuation of a control chamber (16; 66), characterized in that a substantially torsionally rigid working air line (5) is rotatable with a rotary slide supplying or venting the control chamber with working air (4; 40; 70).

2. Rammbohrgerät according to claim 1, characterized in that the control tube (4) rotatably mounted and in the region of the control chamber (16) with a radial branch bore (23) and angularly offset with a channel (18) is provided, and in that of the control chamber with the branch hole and the longitudinal channel corresponding connection channel (17) goes off.

3. Rammbohrgerät according to claim 2, characterized in that between the rear end of the control tube (4) and a connecting sleeve (25) for the working air hose (5) is under pressure system pressure chamber (26).

4. Rammbohrgerät according to claim 3, characterized in that a compression spring (27) is arranged inside or outside the pressure chamber (26).

5. Rammbohrgerät according to any one of claims 1 to 4, characterized in that two parts of the pressure chamber (26) engage in a claw-like manner.

6. Rammbohrgerät according to one of claims 3 to 5, characterized by a with the rohrfömigen extension (28) of the outer tube connected counter sleeve

(32) with depressions (29 a, b) and a projection (30) for the engagement of a pin (33).

7. Rammbohrgerät according to claim 1, characterized in that the rotary slide (40) in the region of the rear end of the control tube (4) is arranged and acting on a one of the control chamber (16) outgoing longitudinal channel (37) on the control sleeve.

8. Rammbohrgerät according to claim 7, characterized in that the rotary slide (40) from a control disc (42) having a radial and a achsparalle- len channel (45) and via these channels, the pressure chamber (16) is exposed to the pressure of the working air or vented.

9. Rammbohrgerät according to claim 8, characterized in that the control disc (42) made of a metallic disc (42) with a permanently elastic

Covering (43) exists.

10. Rammbohrgerät according to one of claims 7 to 9, characterized in that a branch bore (39) and the radial channel (50) in one switching position of the rotary valve (40) with a to the longitudinal channel (37) and the control chamber (16 ) leading housing channel aligned, and that the radial channel in the other switching position connects the longitudinal channel with an exhaust hole (46).

11. Rammbohrgerät according to claim 1, characterized in that the control tube (36) rotatably and non-displaceably mounted in the device housing (1) and connected to a pressure chamber (44), of which in the one switching position of the rotary valve an axially parallel channel (51) leads to one of the control chamber (16) outgoing longitudinal channel (37).

12. Rammbohrgerät according to claim 11, characterized in that the longitudinal channel (37) is connected in the other switching position via an axially parallel bore (45) in a control disc (42) with an exhaust hole (46).

13. Rammbohrgerät according to any one of the preceding claims 1, 3 or 7 to 12, characterized in that the control chamber (66) and the end face (62) of the control sleeve (60) are dimensioned so that within the control chamber (66) prevailing working air pressure acting on the control sleeve with a greater longitudinal force than the acting in the opposite direction on the end face (62) working air pressure.

14. A method for moving a control sleeve of a ram boring machine, characterized by bringing in working air to a larger effective surface of a control sleeve, overcoming an oppositely acting on a smaller effective surface working air pressure and moving the control box by means of the pressure difference or reducing or switching off the working air supply to the larger

Effective area to move the tax box in the opposite direction.