FI63177B - HYDRAULISK SLAGANORDNING - Google Patents

Description

-: ~ Ί rftl .... KU RELEASE PUBLICATION / 7 λ π π [Β] (11) utläggninosskrift 63177 C (45) Patent granted 10 05 1003 Patent aeddelat ^ (51) Kv.ik.3 / int.a3 b 25 D 9/14 l (21) PtMnttihaktinu · —NtMameknlni 751837 (22) HikamitpUvi - An * 6knlnpdt | 19.06.75 (23) Alkuptlvi —Gikl | h «t * di (19.06.75 (41) Tullut) ulklMk * l - Bllvlt off« ntli | 28.06. j6

National Board of Patents and Registration / 44) Date of Nihtiviluiptnon | · kuL | uikaiwn. -

Patent and registration authorities AntiMun utltgd odi utLskrifUn publicarad 31.01.83 (32) (33) (31) Pyydetty atuolkaui — Bagird prlorttat 27-12.7 ^

Federal Republic of Germany-Förbundsrepubliken Tyskland (DE) P 2U6l633.9 (71) Ing. Gunter Kleimn Spezialunternehmen fur Bohrtechnik, 596 Olpe /

Wenkhausen, Federal Republic of Germany-Förbundsrepubliken Tyskland (DE) (72) Gunter Klemm, Olpe, Federal Republic of Germany-Förbundsrepubliken Tyskland (DE) (7 * 0 Leitzinger Oy (51 *) Hydraulic hammer - Hydraulisk slaganordning

The invention relates to a hydraulic percussion device with a working piston moving in a working cylinder and moving guide parts in a steering cylinder, the guide part having a guide surface influenced by the pressure of the control channel with a dilution which, in all piston positions, is in the region of the return channel, the guide channel being divided into two branches opening into the working cylinder.

In known percussion devices of this type (DT-OS 2 029 404), a control channel runs from the working cylinder to the steering cylinder. The working piston has a piston part fitted to the diameter of the working cylinder, one side of which is constantly at full pressure and the other side of which is unpressurized. Depending on the impact position of the piston part, the control channel is connected to either a high pressure or a non-pressurized part. Since the thicker piston part must have a certain minimum height in order to achieve the required seal in the cylinder-blade space, the turning of the guide part by means of the guide channel can only take place after the piston part has passed the guide channel opening at its full height. Short strokes with high strokes are not achievable with known percussion devices due to forced deaths between pivot controls.

63177

In another known hydraulic percussion device (CH-PS 534 567), which operates on several guide channels, one of the guide channels leads to the working cylinder after the comb-like branching. The individual branch lines can be closed one after the other by pushing the spindle forwards, so that the rearmost pivot point of the hammer piston and thus also the impact power can be adjusted. The branch lines have, if the closing spindle is not taken into account, then they have a similar function and their function is only to give a choice. The second control channel leading to the second control surface of the guide part is usually unbranched.

It is further known (DT-PS 551 138) to design the guide part of the pneumatic percussion tool into a slender, the end faces and the interior of which are constantly under high pressure. The guide sleeve is provided with an annular collar placed in the ring space of the steering cylinder, which is connected to the working cylinder via a guide channel. The control channel acts to turn the steering piston to another end position. The turning to the second end position takes place during the return stroke of the working piston by means of the compressed air of the working piston, which affects the second guide surface of the steering piston. The prerequisite for the functionality of this device is that the pressure medium is compressible.

Practice shows that known islands of known hydraulic percussion tools typically have a stroke rate of 700 strokes / min. and up to 3500 - 4000 strokes / min. This is because the reversal of the steering piston, which must take place before the working piston has reached its respective end position, occurs on the one hand too late and on the other hand too slowly. The reason for the delayed turning is that the thicker piston part which closes the guide channel as it passes is too long and the reason for the slowness is that the massively constructed guide pistons, if they have to be dimensioned for short periods to pass large flow rates, are too slow.

The object of the invention is to provide a hydraulic impact device of the type mentioned in the introduction, which is capable of working at high impact rates. To solve this problem, it is proposed according to the invention that in all positions of the working piston at least one guide channel branch is closed by the piston part, and that the first branch is connected to the return channel when opened by the piston part, that, when opened by the piston part with the working piston in the upper position, it communicates with the pressure channel.

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In the percussion device according to the invention, it is possible for the first branch to connect the control channel to the return channel f when the thicker piston part has first closed the connection to the pressure channel · This boundary case can crosslink if the height of the thicker piston part is so high that both branches are simultaneously sealed. If the piston performs a small movement from this position, the second branch opens and connects to the corresponding pressure channel or return channel, so that the corresponding pressure support is transferred to the control part via the control channel. The thicker piston part can then, depending on the distance at which the branches of the guide channel open into the working cylinder, even have a considerable length, so that the designer can freely do so when choosing a geometric dimension.

The control of the stroke rate or the adjustment of the lower pivot of the working piston can be achieved by means of a suitable structure of the invention such that the first branch consists of several branch channels which open in succession into the working cylinder for the piston movement part and can be closed without closing the control channel. Each first branch channel, which is not closed by the plug or the like, determines, within the limits of the piston rod, the time by which the guide channel must be connected to the return channel via the annular groove so that the guide flange decreases and the direction of movement of the guide sleeve changes. In this way, it is possible, for example, to close the outermost branch channel, causing the next branch channel to operate, which causes the working piston to change direction later during its downward movement, which means a lower stroke rate and an increase in the power of single strokes.

The change in the direction of movement of the working piston in the upper turntable el should expediently take place through a sudden abrupt change in the direction of inclination, but as a continuous decrease in the speed of the piston. In the expedient structure of the invention, this takes place in such a way that the second branch consists of a plurality of branch channels which successively open into the working cylinder and increase the cross-sectional area of the guide channel as the impact of the working piston increases. Thus, as the initial length increases, the working piston always gives the free reference pedal of the second branch, which becomes larger, when the branch channels of the second branch are completely closed. Thus, the pressure in the control channel can rise slowly, leading to a steady and non-impulsive change in the direction of movement of the control cylinder. If necessary, chokes can be placed in the branch channels of the second branch, which can be adjustable.

631 77 4

In a preferred structure of the invention, the guide part is constructed as a hollow guide sleeve, which is constantly under high pressure from the inside and from the parts of its embarrassing forehead numbers and which is provided with an annular collar, the second boundary of which forms an interface. The guide sleeve, with low ground clearance, is able to pass through large volumes. The low mass deflection is due to the fact that the wall thicknesses of the guide sleeve only need to be made large enough to withstand the pressures encountered · The guide sleeve can be drilled with a cylindrical hole in the usual way. It is essentially hollow and includes a return spring in any case. The guide sleeve is hydraulically or spring-loaded prestressed in the direction of its end position. Due to the heavy 1-call on the only guide surface, it can be moved to its second end position against prestressing. In this case, only one control channel is required for control.

In a suitable structure of the invention, the effective guide surface together with the smaller end face of the guide sleeve is larger than the large end face, whereby the front surface of the ring collar delimits the ring space connected to the return channel. The control sleeve is then adjusted exclusively hydraulically »so that it is not necessary to use any mechanical return elements. The guide sleeve has an advantage over different large forehead surfaces affected by the same pressure. The pressure in the ohmic channel alone determines whether this front stroke position is maintained or whether the guide sleeve moves to the opposite end position.

The bias can also be provided by a spring which acts in the direction of closing of the line coming from the working cylinder of the guide sleeve against the return channel, this channel being connected to the bead channel via the guide sleeve. In this case, no unpressurized ring space is required in the control cylinder, but the pressures acting on the control sleeve from the different channels can cancel each other out in the second operating mode.

Practice has shown that with the inventive stroke it is possible to achieve about 6000 strokes per million. Of course, due to the adjustability of the upper and lower pivot points of said working piston, lower stroke rates can always be achieved.

In hammer drills where the flushing channel passes through a drill rod connected to the anvil, a flushing tube attached to the working cylinder is suitably guided through the longitudinal bore of the working piston, whereby there is air space between the longitudinal bore wall and the flushing tube.

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The air space takes care of the pressure equalization during the reciprocating movement of the piston. In this way, air cushions are avoided and a constant flow of air inside the piston provides even cooling. With the help of the leaking oil, a fine spray mist enters the air in the working cylinder, which takes care of the additional lubrication of all parts. Even in the absence of a flushing tube, a piston with a longitudinal bore can be used to prevent the effect of shock-absorbing and power-reducing air mattresses.

In a further development of the invention, a percussion tool in which a diaphragm-equipped hydropneumatic double-chamber pressure accumulator is connected to the pressure channel has the guarantee that the channel to the pressure accumulator includes a pressure-connected shut-off valve which closes this channel if the pressure in the pressure channel falls below the limit .

However, it is a matter of placing a throttle valve in the pressure line before the pressure reserve is known (DT-OS 2 024 501), although in a known device the throttle valve has the function of reducing the liquid supply flow and thus the stroke rate when the pressure drops. In contrast, the shut-off valve used in the device according to the invention is not in operation at all during normal use. Only if the hydraulic pressure supply to the pump is interrupted when the unit is stopped will the shut-off valve close and thus prevent the accumulator from discharging too quickly. Sudden discharges of the accumulator are dangerous because the membranes in the accumulator strike with great force against the walls of the pressure vessel and the outlet and, as practice has shown, they often break in such connections. By means of the shut-off valve, it is achieved that the pressure in the pressure accumulator after closing the supply channel is mainly maintained and slowly released due to leaks. In this case, the film is not in danger.

The shut-off valve may consist of a spring-loaded sleeve with end faces of different sizes, which in the open position is completely in the pressure channel and the shut-off position separates the pressure channel coming from the side as well as the pressure channel coming from the side to the pressure accumulator.

The invention will now be described with reference to the drawings of two structural examples.

Figure 1 shows a schematic view of a percussion tool according to the invention in longitudinal section.

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Figure 2 shows a second guide sleeve and associated second cylinder structure in an impact tool that otherwise corresponds to the tool shown in Figure 1.

The working cylinder 10 is arranged to move the working piston 11 in the longitudinal direction. It periodically strikes the anvil 12, which may, for example, be tied to a drill rod.

A hydraulic medium at a pump pressure of approximately 80 bar * is fed to the device via the supply channel 13. It is accessed through the shut-off valve 14 to the pressure channel 15 · The pressure channel 15 is continuously connected to the lower chamber 16 of the cylinder 20, so that the hydraulic pressure continuously acts on the small annular surface 17 in the working cylinder 11 and tends to push it upwards.

The upper chamber 18 of the cylinder is connected via a line 19 to the control valve 20. This connects the line 19 alternately to the pressure line 15 and the return line 21. The upper chamber 18 is limited to the large ring surface 22 of the working piston. When full pressure acts on both the lower ring surface 17 and the upper ring surface 22, forcing the working piston down. Instead, when the pressure means acts only on the smaller ring surface 17 and the channel 19 is connected to the non-pressurized return channel 21, the working piston performs its return slide, during which it moves upwards.

The control valve 20, which in the construction example according to Fig. 1 consists of a spring-loaded guide sleeve 55 *, takes place via a guide channel 24, the pressure of which acts on the guide plate 58 of the ring collar 56. The guide channel 24 branches into the first three branch channels 65, 66, 67 and four second branch hubs 25, 26, 27 and 28, each of which opens into an annular groove in the working cylinder.

In the region of the annular groove associated with the branch channel, the working piston 11 has a lower thick mfinnäne 62, the diameter of which is adapted to the diameter of the cylinder. The piston part 62 is able to close the branch channels with their associated ring tongs tightly. It is bounded by a ring surface 17 at the bottom and a ring surface 61 at the top. A wide ring groove 69 * terminates in the ring surface 61 and above it there is another thick piston part 64 having the same diameter as the piston nose 62.

7 63177 From the area of the piston ring groove 69 a return channel 52 leads from the pole to the cylinder. below the branch pipe 65-67, then the branch channel 65-67 in question is connected to the return channel 52 via the annular groove 69, whereby the control channel 24 becomes palette-free.

The purpose of the plugs 68, which can be inserted into the branch passages 65-67 to selectively close them, is to determine the respective piston position in which the guide channel 24 is de-palmated as described for the first time during the piston start, so that the control gravity 58 of the guide sleeve ceases to act.

The second branch passages 25-28 are below the first branch passages and determine with which piston stroke the pressure of the bellows passage 15 continuously prevailing in the lower chamber 16 of the working cylinder enters the guide passage 24. If the working piston is lifted from its lowest position, the guide passage 24 is essentially depressurized. However, if the lower ring plane 17 enters the area of the lower branch channel 25, then the pressure fluid enters this branch channel and the control channel 24. At the same time, of course, it must be ensured that the first branch channels 65-67 are already closed by this time. The pressure rise in the guide tube 24 is initially relatively slow · The more the second branch passages 26, 27 and 28 begin to act as the piston stroke increases, the larger the cross-sectional area so that the rise of the guide hub 24 occurs progressively as a result of the gradual switching of the branch passages 25-28. during ascent, the guide sleeve 55 does not move in an impulsive manner to its (drawn) lower end position, but turns relatively carefully ·

The pressure in the guide channel 24 is applied to the guide surface 58 of the guide sleeve · The guide surface 58 forms the rear side of the collar 56 which in the construction example in Figure 1 reaches the lower end surface 57 · The diameter of the guide sleeve is constant throughout. The rear end face 30, together with the effective guide surface 58, is exactly equal to the front grip surface 57 ·

The guide sleeve 55 is provided at its rear with a wide annular groove 29, which can connect the bores 19 and 21 of the channel 19 and 21 displaced longitudinally relative to each other. At the second end station, as shown in the drawing, the connection to the return line 21 is closed by the guide sleeve, the bore channel 19 is open and is thus connected to the passage inner part of the guide sleeve and the pressure sleeve 15 to explain the use of the I / O tool from the position of the parts shown in the drawing. to the duct 15 and closes the connection to the return line 21, since the full pressure affects both the upper large ring surface 22 and also the lower small ring surface 17, the working piston 11 moves downwards. In this case, the piston part 62 at its lower annular surface 17 initially closes the branch passages 28, 27, 26 and 25 in succession to then open the first branch passages 65, 66 and 67, if they are not closed by the plug 68, the lower branch passage 25 and the upper branch passage 65. when opened, it will be connected to the non-pressurized ground return line 52, How is the force acting on the guide surface 58 of the guide sleeve reduced. As a result of the force exerted by the pressure on the larger front surface 57, the guide piston 55 protrudes against the spring 31, the guide piston then rests mainly against the seat 32 in its lower surface, so that the pressure of the flange 15 can only partially act, but grooves 33 are provided in the front surface 57. . In addition, the guide sleeve 55 is acted upon by an upwardly directed spring 34 which is secured to the housing by a holder 35. The purpose of this spring is only to facilitate the release of the guide sleeve from the seat 32 in order to ensure that full fluid pressure can be applied to the lower end face 57. As the movement continues, the spring 34 no longer touches the guide sleeve. The spring 31, on the other hand, is increasingly compressed until the upper gripping plate 30 presses against the housing, the fluid flow through the guide sleeve 55 must thus be cut off with the channel 19 through the annular groove 29 connected to the return channel 21, the upper chamber 18 thus depressurized. Its lower annular edge 17 then first opens the lowest branch channel 25. Through this, fluid flows from the bellows to the guide channel 24. The amount of liquid flowing increases as the second branch holes 26, 27, 28 continue to engage the channel as the piston stroke continues, the pressure in the control channel finally reaches it is sufficient to push the guide sleeve 55 back to the position shown in the drawing, where the channel 19 connects to the flange duct 15 via the inner part of the sleeve and is closed from the return channel 21. Due to the slow pressure increase in the guide channel 24 the guide sleeve rises softly during its return. As a result, the 9 63177 working piston 11 brakes slowly and evenly and does not strike the non-compressible Nest pad. The working piston 11 has an elongate bore 41 through which the flushing tube 40 passes. However, the elongate bore 41 is looser than the flushing tube, so that an annular air space is created between the two. As the working piston reciprocates, air is continuously pumped in the working cylinder through the plt hammer bore 41. This acts, firstly, as a coolant for the inside of the working piston and, secondly, also ensures the lubrication of the limescale spots, since the constantly circulating air contains leaking oil in the form of a spray mist. This oil is evenly exposed to limescale where abrasion can occur. Finally, the pumping function prevents the formation of air cushions that would absorb some of the impact power.

In the described percussion tool, the supply pattern 15 is connected in a known manner to a liquid air pressure accumulator 45. This consists of a chamber containing high-pressure gas and a second chamber directly connected to the supply or pressure channel. The two chambers are separated by a rubber membrane 44. The function of the pressure accumulator is to receive additional pressurized fluid from the pump at each movement time when only a small amount of pressurized fluid is required to move the piston and to supply this fluid to each actuator with high piston fluid demand. When using this type of pressure accumulator el the pump power has to be dimensioned according to the required maximum value, but only needs to correspond to the average between high and low liquid demand. One difficulty of this type of pressure accumulator is that when the supply line 15 is depressurized, the diaphragm 44 is under high pressure. the gas strikes the wall of the tank in an impact-like manner and then breaks. In practice, in fact, ruptures of the diaphragm almost always occur when the pressure pump is stopped. · To avoid this difficulty, the shut-off valve 14 is made in the shape of a spring-loaded sleeve 45. At the lower end of the sleeve there is a collar 46, the rear side of which is connected to the non-pressurized return channel 21. The spring 47, which pushes the guide sleeve downwards, is dimensioned so that the pressure acting on the lower end face 48 pushes the guide sleeve 45 normally upwards. to resist the force of the spring 47, the normal pressure of the pressure accumulator 43 is 50 bar,

In the open position of the guide sleeve 45, the supply line 13 is connected to the pressure accumulator 43 and the pressure line 15t through the inner part of the guide sleeve. 49 through, so very slowly. This protects the film 44.

The drawing also shows seals 50 which seal the ends of the working piston against the housing, as well as leakage channels 51 which open into the return channel 21 and which, in spite of the seals, drain away the oil adhering to the ends of the piston.

Figure 2 shows another design of the guide sleeve 55 ', which requires a slight change in the guide cylinder. The guide sleeve 55 'has a circumferential collar 56' having a larger diameter than a continuously high pressure front end surface 57. The front collar interface 56 'is formed by a sloping surface 59. This defines a guide cylinder annular space which communicates with the return line 21 via a channel 60. exclusively hydraulically, i.e. without spring forces or the like. The high pressure continuously acts both well on the larger end face 57 and on the opposite smaller end face 30. If the pressure in the guide channel is low, the force acting on the end face 57 overcomes and the guide sleeve 55 'protrudes upwards. If the pressure in the guide channel 24 rises, the pressures acting on the surfaces 30 and 58 exceed the force acting on the end face 57 - the guide sleeve slides downwards. It will be appreciated from this that the pressure acting on the rear surface 58 of the collar 56 'from the guide channel 24 is solely decisive with respect to the current position of the guide sleeve.

Grooves can also be made in the end face 30 to ensure that high pressure can act on the end face 30 and lift the guide sleeve up from its end position.

Each part which is unchanged in the solution model of Fig. 2 with respect to the corresponding parts of Fig. 1 is provided with the same reference numerals, which will not be described in more detail at this point.

The advantage of the solution model according to Figure 2 is that no springs of any kind are required to provide prestressing or to raise the guide sleeve. Manufacturing is therefore simpler and less abrasive. Both guide sleeves 55 and 55 'are advantageous in that the remote movement takes place only through a single channel, namely the guide channel 24. This channel has no branches and leads only at a single point inside the steering cylinder. With the exception of the rear collar surface 58, the piston heads of the guide sleeve are always under the same pressure, which results in a simple passage of the channels and the number of guide channels leading to the working cylinder is limited to one.

Also, the guide sleeve itself is simple to manufacture, as it has only one through-bore that is straightforward.

The front or rear collar surface of the guide sleeve may, as shown in the drawings, be chamfered. Understandably, when dimensioning these surfaces, the gravitational forces el. These are effective surfaces in each case.

Claims (3)

12,631 77 A hydraulic percussion device with a working piston (11) movable in a working cylinder and moving guide parts (55) in a steering cylinder, the guide part having a guide surface (58) influenced by a pressure of a guide channel (24) in communication with the pressure channel (15) and a substantially unpressurized return channel. (21), and wherein the working piston is provided with a thinner between two piston parts (62, 64) arranged in the diameter of the working cylinder, which in all piston positions is in the region of the return channel (21, 52), the guide channel (24) being divided into two working cylinders (10). branch (65-67; 25-28), characterized in that in all positions of the working piston (11) at least one branch of the guide channel is closed by the piston part (62), and that the first branch (65-67) is arranged so that after opening the piston part (62), with the working piston in the down position, communicates with the return channel (52) and that the second branch (25-28) is arranged so that when it is opened by the piston part (62) with the working piston (11) in the upper position, it communicates with the pressure channel (15). Impact device according to Claim 1, characterized in that the first branch consists of a plurality of branch channels (65 to 67) which open onto the piston path in succession into the working cylinder (10) and can be closed independently without blocking the guide channel (24). Impact device according to Claim 1 or 2, characterized in that the second arm consists of a plurality of arms (25 to 27) which open in succession into the working cylinder (10) and increase the cross-sectional area leading to the guide channel (24) as the working piston strikes.