FI62480C - SLAGANORDNING - Google Patents

Description

”“ ^ ”'. 1 Γβ1 ANNOUNCEMENT

^ ÄTä ® i11) UTLÄGG NI NGSSKRIFT 6 2 4 8> 0 (45) Patent .τ ..:. ΡPii t ^ ^ (S1) Ky.lk?/Int.a.3 B 25 D 9/14 SUOMI-FINLAND <*) PKunttihakumu · ~ PutantamMuilnf 731657 (22) Hakwnltpilvt - AiMdfcnlngvd ·· Ot.o6.75 (23) Alkupilvt — Glklfhacadag 0t.06.75 (41) Tullut lulkhulul - Blhrtt offantltg 12.12.75 PM « «Government (44¾ ΝΜΜ§νΐωρβηβΛ μ month / month)

Patani och ragistarstyralsan 'AmMcm utla «d« ch uti. * K rtfu * »pubUeuratf 30.09.82 (32) (33) (31) Pyr ^ utty« tuolkMM — Buglrd prlorluc H. 06.7t

Federal Republic of Germany-Förbundsrepubliken Tyskland (DE) P 2t28236.8 (71) Fa. Ing. Gunter Klemm Spezialunternehmen fur Bohrtechnik, 596 Olpe /

Wenkhausen, Federal Republic of Germany-Förbundsrepubliken Tyskland (DE) (72) Gunter Klemm, Olpe, Federal Republic of Germany-Förbundsrepubliken Tyskland (DE) (7t) Leitzinger Oy (5t) Impact device - Slaganordning

The invention relates to an impact device having a working piston movable in the working cylinder by a pressure medium and a substantially hollow guide sleeve movable in the steering cylinder, both different large end faces of which are continuously pressurized. the line from the working cylinder alternately to the pressurized line and essentially unpressurized to the return line.

In a known impact device of this type (DT patent publication 551 138), which is intended for use in compressed air, both end surfaces of the guide sleeve are always under full operating pressure. Since the second end surface is larger than the opposite end surface, the guide sleeve receives a continuously acting prestress towards its second end position. In order to perform the steering movement, two guide surfaces are provided, which are directed in opposite directions and have different sizes. The second guide surface is affected by the pressure due to the air piston 2 62480 compressing air during its return stroke, while the pressure supply to the opposite guide surface becomes closed by the working piston. such pivot control of the guide sleeve by compressing the pressure medium during the return stroke of the working piston is only available with pneumatic percussion devices.

Another known percussion device (DE 443 644) uses a hollow guide sleeve which is actuated by forcibly moved rods. Control with a pressure medium is not provided.

Impact devices using a full-length control piston (DE patent 1,243,118, DE patent 2,029,404 and CH patent 534,567) are generally not useful when higher flow rates have to be switched with short reversing switching times because the flow channels are narrow. complicated and because the steering piston has a large mass. If the flow channels are enlarged, then a larger piston diameter must be selected for the massive control piston. In this case, the mass of the piston increases and the inertia of the control piston increases at the same time.

The object of the invention is to make the guide sleeve in an impact device of the type mentioned at the beginning even simpler and lighter, so that the number of strokes can be increased.

To achieve this object, the impact device according to the invention is characterized in that the larger end surface of the guide sleeve of the hydraulically driven impact device is oriented in the opposite direction to the ring collar guide surface and is at most equal to the single operating guide surface and the smaller end surface combined, and the ring piston is known to be continuously pressurized. .

The impact device according to the invention has, in addition to the end surfaces which are constantly under full pressure, the guide sleeve has only a single guide surface on which the swivel control functions for both directions of movement are provided by the pressure of the guide wire. The guide sleeve 62480 is thus only affected by a single guide pressure which acts on a single guide surface. The guide sleeve has a bias in the direction of the smaller end surface. This hydraulic preload is counteracted by the pressure on the control surface. Its size alone determines whether the guide sleeve remains in the second end position or is moved to the second end position.

The impact device according to the invention is relatively simple in construction and has improved operating properties compared to known impact devices. In particular, it has a high stroke rate and correspondingly high flow rates. The percussion device according to the invention achieves e.g. 6000 strokes / min. blow figures. The wall thickness of the guide sleeve must thus be made so large that it can withstand the pressures that occur. The guide sleeve can be drilled cylindrically. It is essentially hollow and includes a return spring in any case.

In a further development of the invention, the effective guide surface together with the smaller end surface is larger than the larger end surface and the front surface of the ring collar limits the ring space associated with the return line. The guide sleeve is then moved exclusively hydraulically, so that no mechanical return means need be used. The guide sleeve has, due to two differently sized end faces affected by the same pressure, a privileged position. The pressure in the control line determines whether this priority position is maintained or whether the control sleeve goes to the opposite end position.

Alternatively, the guide sleeve may also be biased by a spring in the direction in which it closes the line coming from the working cylinder relative to the return line, whereby the line coming from the working cylinder communicates with the pressure line via the guide sleeve.

4,62480

An additional problem solved by the present invention occurs in the adjustment of the turning point of the working cylinder. In a known percussion device (CH patent publication 534,567), the control line leads out of the working cylinder in the form of a plurality of branch lines which converge close to the working cylinder. The branch wires, which are stepped in the axial direction, can be closed with guide slides. By releasing the various branch lines, the upper pivot point of the working piston can be determined with each stroke, determining the position of the piston where the pressure fluid enters the control piston from the cylinder without an unclosed branch line and forcing it to the position causing the downward movement of the working piston. Determining the upper pivot point of the working piston and thus the stroke of the piston is necessary in order to convert the best available impact energy. In the known percussion device, a reversal of the direction of the steering piston is initiated in an impulsive manner when the lower annular surface of the piston reaches the first unsealed branch line. A sudden reversal of the steering piston also results in a reversal of pressure to the impact. This is braked in the form of an impact, which produces corresponding reaction forces in the working cylinder and in the housing of the impactor. As a result, all parts are subjected to high stress at the end of the return stroke. According to the invention, there is provided an impact tool in which the return stroke of the piston is adjustable, but its final position is not impulsive, but it reaches the final position as its speed continuously decreases. This is due to the fact that at least one free cross-sectional free-adjusting choke element is arranged in the control line.

By fitting the throttle member to the control line, it is achieved that the direction of the control piston is not changed impulsively, but evenly when the working piston releases the opening of the control line. Due to the throttling point, the high pressure inside the working cylinder does not transfer to the control piston in an impulsive manner, but is slowly affected first. Therefore, the control piston moves with a certain deceleration, as a result of which the working piston is also braked correspondingly slowly until it finally forms a full back pressure when completing the reversal. Due to the fact that the effect of the throttle member is adjustable, the deceleration at which the reversal takes place can be easily changed after the ring edge of the piston has passed the guide wire.

In a preferred embodiment of the invention, the control line, as is known, has a plurality of branch lines extending from and connected to the working cylinder of the piston guide and that an adjustable choke member is arranged in the plurality of branch lines.

62480

During the return stroke of the working piston, more branch lines are released, so it becomes effective. In this way, the throttling effect gradually decreases and the pressure adjusting the steering piston increases correspondingly until the reversal is completed.

The choke members in the branch lines can be staggered in thickness and can taper towards the return position of the piston. In the return stroke, the ring edge of the piston first comes to the most constricted branch line so that the reversing force acting on the guide sleeve first increases very slowly. As you pass the next branch line, the reversing force increases more and more, etc. With this stepped damping, a calm and continuous reversal is achieved. By adjusting the throttle members, the end position of the piston can be adjusted very easily. Threaded pins or the like can be used as choke members, which are very well suited for adjustment purposes.

In drilling hammers in which the flushing line passes through the drill rod associated with the anvil, it is expedient that a flushing tube attached to the working cylinder is passed through the longitudinal bore of the working piston and that there is an air space between the longitudinal bore wall and the flushing tube. The air space takes care of the pressure equalization during the reciprocating movement of the piston. This avoids the painepatoutumat and continuous air movement inside the piston ensures uniform cooling. The leakage oil is achieved thanks to the working cylinder into the air fine vihmoitussumu that keeps the lubrication of all parts of the concerns. If there is no purge tube, a piston with longitudinal bore can be used to avoid the shock absorbing and energy absorbing effect of the airbags.

According to a further development of the invention, in an impact tool in which a diaphragm-containing hydropneumatic two-chamber pressure accumulator is connected to the pressure line, it is expedient to arrange the line to the pressure accumulator including a pressure-dependent shut-off valve which closes the line when the pressure in the line falls below the limit value. above normal operating pressure. However, it is known to adapt the throttle valve to the pressure line (German.

kuul.julk. 2,024,501), but in this known device the function of the throttle valve is to reduce the inlet flow of the liquid and thus the stroke rate when the pressure decreases. In contrast, the shut-off valve used according to the invention is not functional at all during normal use.

6 62480

Only when the supply of hydraulic pressure from the pump when the device is disconnected is switched off does the shut-off valve close, thus preventing the pressure accumulator from being released too quickly. Sudden releases of the pressure accumulator are dangerous because the membranes contained in the pressure accumulators are struck with high force against the wall and the outlet of the pressure vessel, whereby, as practice has shown, they usually break. The shut-off valve ensures that the pressure in the pressure accumulator after disconnecting the supply line is initially maintained and slowly decreases due to leakage currents. This will not break the film.

The shut-off valve is formed by a spring-loaded sleeve with different sized end faces, which in the open position is open to the pressure line in the pressure line and in the closed position separates the side pressure line from the side line to the pressure accumulator. removal of the cord.

The invention is explained in more detail below with reference to the drawings of two application examples.

Figure 1 schematically shows a longitudinal section of an impact tool according to the invention.

Fig. 2 shows another embodiment of a guide sleeve and an associated cylinder in an impact tool, which otherwise corresponds to the impact tool according to Fig. 1. .

A longitudinally displaceable working piston 11 is arranged in the working cylinder 10. It strikes the anvil 12 intermittently, which may, for example, be connected to the drill arm.

Through the supply line 13, a pressure medium is introduced into the device, which is under a pressure of about 80 bar under the action of the pump. The pressure medium passes through the shut-off valve 14 to the pressure line 15. The pressure line 15 is continuously connected to the lower chamber 16 of the cylinder 10 so that the hydraulic pressure always acts on the small ring surface 17 of the working piston 11 and tends to force the working piston upwards.

The upper chamber 18 of the cylinder is connected to the control valve 20 via a line 19. This connects line 19 alternately to pressure line 62480 and return line 21. The upper chamber 18 is bounded by the large annular surface 22 of the working piston. Thus, when full pressure acts on both the lower annular surface 17 and the upper annular surface 22, the working piston extends downwards. In contrast, when the pressure medium acts only on the smaller ring surface 17 and the line 19 is connected to the unpressurized return line 21, the working piston performs its return stroke as it moves upwards.

The control valve 20, which in the embodiment according to Fig. 1 is formed by a spring-loaded valve sleeve 23, is controlled by a control line 24 which is comb-like in several branch lines and which communicates with the lower chamber 16 via each branch line 25, 26, 27, 28. The guide line 24 terminates in the guide sleeve 23 and although its pressure always acts on the return side of the collar 56 of the guide sleeve 23. The collar 56 forms at its front surface the end face 57 of the guide sleeve. The inner extent of the guide sleeve is completely non-fading except for the support for the springs. The rear face 30, together with the back surface of the collar 56, is exactly as large as the front face 57.

At the rear end of the guide sleeve 23 there is a wide annular groove 29 which can connect to each other the bores which are offset in the longitudinal direction of the wires 19 and 21. At the second end position shown in the drawing, the connection to the return line 21 is closed by a guide sleeve, while the bore is released into the line and thus communicates with the through guide sleeve and the pressure line 15.

To explain the use of the impact tool, let's start with the position shown in the parts drawing, where the guide sleeve 23 connects the line 19 to the pressure line 15 and closes the return line 21. Since full pressure affects both the upper large ring surface and the lower smaller ring surface 17, the piston 11 moves rapidly downwards. In this case, it separates the successive branch lines 25, 26, 27 and 28 from the lower chamber 16 under full pressure. Since the control line 24 is finally separated from the pressure supply, the pressure therein ceases, reducing the force acting on the return side of the guide sleeve 23 collar 56. Under the pressure of the force acting on the larger end face 57, the control piston 23 will move upwards. In this case, the guide piston initially rests completely on the seat 32 with its lower end face, whereby the pressure in the pressure line 15 may possibly be only partially effective. However, cuffs 33 are provided on the front surface 57 into which the pressure medium can penetrate. In addition, the guide sleeve 23 is acted upon by an upwardly directed spring 34 fixed to the housing by a holder 35. The sole purpose of this spring is to facilitate the lifting of the guide sleeve from its seat, thus ensuring that full fluid pressure can act on the lower end surface 57. the guide sleeve. In contrast, the spring 31 is more compressed until the upper end face 30 rests on the housing. Then the flow of liquid through the guide sleeve 23 is thus interrupted, while the line 19 communicates with the return line 21 via the annular groove 29. Thus, the upper chamber 18 is depressurized so that the working piston 11 can again be forced upwards. In this case, the lower annular surface 17 first releases the lower branch line 28, into which a choke member in the form of a relatively thick choke pin 36 is fitted. Thereafter, the effective cross-section of the branch line 28 is only very small. However, a small amount of fluid flows into the guide line 24 so that initially a very slow pressure acts again on the return side of the collar 25, 56.

A choke pin 37 is also arranged in the second branch line 27. The diameter of this is smaller than the diameter of the throttle pin 36 and therefore causes a slightly faster pressure rise in the control line 24. Finally, a choke pin 38 is likewise fitted to the third branch line 26. The cross section of the last branch line 25 is not reduced.

During the return stroke of the working piston 11, the increasing pressure in the control line 24 is accelerated the more the branch lines are connected to the pressurized chamber 16. The choke pins provide a delayed build-up of pressure in the control line 24. The pressure finally reaches a level sufficient to move the guide sleeve 23 to the shown position again, where the line 19 is connected to the pressure line 15 via the sleeve interior and disconnected from the return line 21. Due to slow pressure build-up in the control line 24 slowly ceases its downward movement so that the line 19 does not become impactfully pushed under pressure. As a result, the working piston 11 is slowly and continuously braked and does not strike the uncompressed hydraulic pad.

In principle, it would already be sufficient for the guide line 24 to have only 9 62480 one choke member, since this, too, could also develop a delayed pressure build-up at the collar of the guide sleeve 23. However, the staggered arrangement of several branch lines 25, 26, 27, 28 with different strong attenuations has proved to be very advantageous in practice in order to be able to precisely adjust the upper pivot point of the piston. The stronger the damping at the branch lines, the higher the upper pivot point of the piston. The adjustment is effected by adjusting the screw pins 36, 37, 38 which extend transversely into the branch lines 26 to 28 extending perpendicular to the control line 24.

Since the percussion tool shown is used for drilling rigs, a flushing tube 40 passing longitudinally between the working cylinder and the working piston is arranged, which is guided by sealing through the upper wall of the upper cylinder. The working piston 11 has a longitudinal bore 41 through which the flushing tube 40 passes. However, the longitudinal bore 41 is also in the form of a flushing tube so that there is an annular air space between the two. As the working piston reciprocates, air is continuously pumped through the working cylinder. This provides, firstly, cooling inside the working piston and, secondly, also lubrication at all points, since the continuously circulating air contains leaking oil in the form of spray mist. This oil comes to all points where friction can occur. Finally, pumping avoids the formation of air cushions that would consume impact energy.

In the percussion device shown, a hydropneumatic pressure accumulator 43 is connected to the supply line 13 in a known manner. This is formed by a chamber containing gas at high pressure and a second chamber which is in direct contact with the supply line or pressure line. The chambers are separated by a rubber diaphragm 44. The function of the pressure accumulator is to provide this fluid at times when only a small amount of pressure fluid is needed to adjust the piston, which pressure fluid is taken from the moving pressure fluid from the pump and during circulation times when the piston fluid demand is high. When using such a pressure accumulator, the pump power does not have to be dimensioned according to the required maximum value, but only corresponding to the average of the large and small liquid requirements.

One difficulty with such pressure accumulators is that when the pump is disconnected, i.e. when the supply line 13 is depressurized, a high pressure gas ejects the diaphragm 44 against the wall of the container 44, causing it to rupture. In practice, in fact, ruptures of the diaphragm almost always occur when the pressure pump is disconnected.

To overcome these difficulties, a shut-off valve 14 formed by a spring-loaded sleeve 45 is provided. At the lower end of the sleeve there is a collar 46, the return side of which communicates with the non-pressurized return line 21. The spring 47 which forces the guide sleeve downwards is dimensioned so that the pressure acting on the lower end face 48 usually forces the guide sleeve 45 upwards. The guide sleeve only lowers when the pressure in the pressure line has dropped below, for example, 70 bar and can no longer act against the spring 47. The normal pressure in the pressure accumulator 46 is 50 bar.

In the opening position of the guide sleeve 45, the supply line 13 is connected to the pressure accumulator 43 and the pressure line 15 via the interior of the guide sleeve. If the pressure in the pressure line 15 drops below 70 bar, then the guide sleeve lowers and separates the two said lines. The pressure prevailing in the pressure accumulator can now not be reduced in an impact-like manner, but only through the cavities 49 in the lower end face of the guide sleeve, i.e. very slowly. This results in a saving of the film 44.

The drawings also show seals 50 for sealing the working piston ends against the cylinder, as well as leakage lines 51 terminating in the return line 21, which, despite the seals at the piston ends, still drain the liquid. The leakage line 52 further leads to the center of the working cylinder, where the working piston is thinned to reduce friction.

Figure 2 shows another embodiment of the guide sleeve 23 ', which requires a slight change in the guide cylinder. The guide sleeve 23 'has a circumferential collar 56' having a diameter larger than the diameter of the continuously high pressure end surface 57. The front boundary of the collar 56 'is formed by an oblique surface 59. This limits the annular space of the guide cylinder connected via the line 60 to the return line 21.

In this guide sleeve, the steering takes place exclusively hydraulically, i.e. without spring forces or the like. The high pressure continuously acts on both the larger end face 57 and the opposite smaller end face 30. If the pressure in the guide line 24 is low, then the force acting on the end face 11 62480 57 wins and the guide sleeve 23 'protrudes upwards.

If the pressure in the guide line 24 rises, then the forces acting on the surfaces 30 and 58 exceed the force acting on the end face 57 and the guide sleeve moves downwards. It will be appreciated that the pressure acting from the guide wire 24 on the rear surface 58 of the collar 56 'is crucial for the particular position of the guide sleeve.

The end face 30 may also be provided with cavities to ensure that high pressure acts on the end face and the guide sleeve can rise from its end position.

Those parts which in the embodiment of Fig. 2 are unchanged with respect to the embodiment of Fig. 1 are denoted by the same reference numerals. They are no longer explained in detail in this section.

The advantage of the application example according to Figure 2 is that no springs of any kind are required to prestress or lift the guide sleeve. As a result, manufacturing is simple and wear is minimal. Each guide sleeve 23 and 23 'offers the advantage that the control movement is initiated via one line, namely the guide line 24.

This line has no branches and leads to only one point on the steering cylinder. With the exception of the rear collar surface 58, the surfaces of the piston of the steering cylinder are always pushed under the same pressure, which achieves a simple installation of the line and the number of guide wires introduced into the working cylinder is limited to one. Also, the guide sleeve itself is simply fabricable because it has only one through-bore that is rectilinear.

The front and rear surfaces of the guide sleeve collar may be beveled, as shown in the drawings. For the adjustment of the guide sleeve for the acting compressive forces, the dimensioning of these surfaces is of course not determined by the actual size of the inclined surfaces, but only by the radial surface components of the surfaces 58/59 and the projection of the surfaces in the axial direction. These are the impressive surfaces in each case.

Claims (6)

1. Impact device having a working piston movable in the working cylinder by means of a pressurized medium and a substantially hollow guide hollow movable in the steering cylinder, both of which have different large end surfaces continuously under the influence of pressure and in which the control hollow is a ring collar in the annular space for the steering cylinder, in which the steering line from the working cylinder opens, wherein the steering hollow joins the one coming from the working cylinder in turn with the pressure line and the substantially pressureless return line, characterized in that the larger end surface (57) of the steering hollow (23) for the hydraulically driven the impact device is oppositely directed in relation to the guide surface (58) of the ring collar (56) and is at most equal to the only operative guide surface (58) and the smaller end surface (30) together, and that the working surface (17) ring surface (17), as in and known to itself, are continuously under the influence of pressure. The impact device according to claim 1, characterized in that the effective guide surface (58) together with the smaller end surface (30) is larger than the larger end surface (57), and that the front surface (59) of the annular collar (56 ') defines it. the return line (21) connecting the ring compartment. The impact device according to claim 1, characterized in that the guide hole (23) is biased by a spring (31) in the closing direction of the line (19) coming from the working cylinder towards the return line (21), this line (19) through the guide hole (19). 23) mediation interferes with the pressure line (15); The impact device according to any of claims 1-3, characterized in that at least a controllable throttle member (36, 37, 38) is provided, which optionally varies the flow cross-section. The impact device according to claim 4, characterized in that in the control line, as is known per se, several, along the path of movement of the piston from the working cylinder (10), are present.