FI123187B - Rock-breaker impactor, method for controlling impactor - Google Patents

Abstract

The invention relates to a percussion device of a rock breaking device, a method for controlling the percussion device and a rock drilling unit. The percussion device (11) comprises a percussion piston (33), the work cycle of which is controlled by means of a control valve (40, 77). During the movement of the percussion piston, a pressure pulse is generated by closing a pressure connection (Y1, Y2) from at least one impulse space (44, 45) surrounding the percussion piston. The pressure pulse is used to change the position of the valve from one extreme position to an other. The impulse space is an annular space defined in a radial direction by the percussion piston and the frame (25).The frame is further provided with at least one impulse channel (58, 59) for transmitting a pressure pulse to the pressure surface of the control valve.

Description

Rock-breaker impactor, method for controlling impactor

Background of the Invention

The invention relates to a pressure-medium rock-breaking device for impacting rock which can deliver shock pulses to a rock-breaking tool. The impactor comprises a percussion piston which is pressurized to act on its working pressure surfaces, whereby the percussion piston reciprocates in the direction of impact and in the return direction. The impact piston cycle is controlled by a control valve having positions for controlling the pressure medium to act on and away from the working pressure surfaces of the piston. The control valve operation is controlled by the use of a pressure pulse formed as the percussion piston moves in accordance with its cycle.

The invention further relates to a method for controlling the rotation cycle of a hydraulic piston impact piston.

The field of the invention is more fully described in the preambles of the independent claims of the application.

Rock-breakers have a piston that reciprocates and strikes a tool or spacer on the front of the piston. Hydraulic impactors typically have a control valve that directs pressurized fluid flows to and from the working pressure surfaces of the piston, thereby controlling the reciprocating movement of the piston, i.e. the cycle. The position of the control valve is changed relative to the position of the percussion piston by introducing pressure fluid through the control pressure channels to the working pressure surfaces of the valve. The shoulders in the percussion piston displace the pressure medium flow needed to move the valve. It has been found that a large amount of pressure fluid is required to control the control valve momentarily and that leakage currents over the piston shoulders

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£ are high. Due to these factors, the efficiency of conventional impactors is inadequate.

BRIEF DESCRIPTION OF THE INVENTION The object of the present invention is to provide a novel

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30, and a method for controlling its cycle.

O) The impact device according to the invention is characterized in that the impulse is delimited by the impact piston and the body when viewed in the radial direction of the impact piston; and that the first pressure connection comprises at least one impulse channel in the body.

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The method according to the invention is characterized in that a pressure pulse is generated in an annular impulse space delimited radially by the piston and the body; and transmitting a pressure pulse from the impulse state in the impulse channel in the body to the control valve located at a distance 5 from the impulse state.

The idea is that the stroke of the percussion piston is controlled by a pressure-controlled control valve whose position is changed at least in one of its extreme positions by applying a pressure pulse to the pressure surface of the valve, thereby giving the valve an initial impulse to change. The pressure pulse is formed in an impulse state, from which the piston 10 closes the pressure connection during its movement, thereby forming a closed pressure state. The impulse space is an annular space defined by the piston and the body of the impactor when viewed in the radial direction. The body has at least one im pulse channel for supplying a pressure pulse to the valve.

One advantage of the disclosed solution is that it allows a simple and robust structure to identify the position of the piston. The resulting pressure pulse is used to initiate a change in the position of the control valve. It is no longer necessary to control the high-pressure fluid volumes by means of the piston shoulders to move the control valve. Further, the efficiency can be improved by reducing leakage flows. The percussion piston edge or hel-20 puncture is a significant single leak in conventional impact devices. The proposed solution enables the formation of sufficiently long sealing surfaces and the reduction of leaks.

The idea of one embodiment is that the control valve is separate from the impulse state.

The idea of one embodiment is that at least in the stroke direction of the stroke piston there is an impulse state in which the position of the stroke piston in the stroke direction is recognized by means of a pressure pulse formed. In the impulse impulse direction,

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The pressure pulse generated in the blade gives the control valve an initial thrust towards the v position which causes the piston to move in the reverse direction.

The idea of one embodiment is that the position of the percussion piston is detected by the pressure pulses generated in both directions of movement, i.e., the stroke direction and the return direction, in the impulse states. In this case, the impact device comprises a first impulse valve in the impact direction and a second impulse chamber in the reverse direction. The pressure pulses generated in the impulse modes 00 35 give the control valve an initial impulse at both its extreme positions.

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The idea of one embodiment is that the percussion piston comprises a single impulse shoulder having impulse edges in the direction of impact and return.

The idea of one embodiment is that the percussion piston comprises 5 impulse blades spaced axially apart. The first impulse shoulder has an impulse edge towards the direction of impact and the second impulse shoulder has an impulse edge towards the reverse direction.

The idea of one embodiment is that the control valve is a sleeve-like piece that surrounds the percussion piston. The sleeve-like control-10 valve is further located in the impactor at an axial distance from the impulse spaces.

The idea of one embodiment is that the control valve is a spool valve comprising a mechanical pressure-controlled control slide. The spool valve control slide is located separately from the impact piston and impulse mode.

The idea of one embodiment is that the percussion piston comprises two impulse blades axially spaced apart. The diameters of the impulse blades are different, so that the displacement volume of the impulse blades is different in the impact direction and in the reverse direction. This application makes it possible to influence the magnitude of the pressure pulse in different directions of movement of the piston. The idea of one embodiment is that the diameter of the first impulse shoulder on the direction of impact is smaller than that of the second impulse shoulder on the reverse side. In this case, the lower movement velocity of the piston in the return direction is compensated for by the greater pressure area compared to the direction of impact, where the velocity of the piston is higher. Thanks to this application, the magnitude of the pressure pulse can be substantially the same in both the impact direction and the reverse direction. This is important when o the force pulse generates a force in the control valve control slide

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^ to influence the country. The difference in velocity between the stroke piston stroke and the return stroke can be compensated by other means than by means of impulse blades or similar areas.

| The idea of one embodiment is that the percussion piston has a sleeve-shaped control valve adapted to move axially between the first control station and the second control station. The outer circumference of the sleeve-type control valve has control pressure surfaces acting in the direction of impact and return, which are influenced by the pressure of the pressure medium to determine the position of the control valve. Further, the impulse states are located axially 4 from the control valve. The impulse spaces are also closer to the impact surface at the front end of the percussion piston than the control valve. An alternative embodiment may be that the structure is otherwise similar, but the axial order of the control components is reversed such that the control valve 5 is positioned closer to the impact surface than the impulse states.

The idea of one embodiment is that the impulse passages are bores formed in the body of the impactor by means of which the impulse spaces are connected to the pressure surfaces of the control valve.

The idea of one embodiment is that the control valve is provided with a holding circuit adapted to direct the pressure medium to the control pressure surfaces of the control slide and to hold the control slide in the first end position and the second end position. The pressure pulse applied from the impulse modes through the impulse channels provides a momentary force to the guide slide, which suppresses the movement of the guide slide towards the opposite end position. The pressure pulse 15 thus generates a momentary force effect on the guide slide and pushes it into motion. When the initial impulse is given, the forces generated by the holding circuit execute the movement of the control slider to the end position, where the control slider will wait for the next pressure pulse and again the subsequent movement to the opposite end position. The control valve provided with the retaining circuit may comprise a sleeve-like control slide 20 around the percussion piston, or the control valve may be a spindle valve spaced apart from the percussion piston.

The idea of one embodiment is that the holding pressure is activated by the control valve by its shifting movement. The holding pressure and the resulting holding force are thus not directly activated by the impact piston.

The idea of one embodiment is that the control valve has at least one pressure surface on which the pressure of the pressure medium acting on it can be adjusted. This adjustment can be used to influence the movement speed of the control valve

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^ in the direction of movement of the piston reciprocating. By adjusting the pressure and the resulting velocity control, it is possible to influence the stroke length of the piston and thereby also the stroke frequency of the impactor.

| The idea of one embodiment is that the impactor comprises o) one or more actuator valves or actuator circuits for repositioning the stopping impact control valve to a predetermined position to initiate a new cycle of the impactor. The impact piston 00 35 can also be moved by a start valve to a predetermined position for start-up. After start-up, the impactor shall remain in operation as long as the pressure medium is not supplied to it.

The idea of one embodiment is that the body of the impactor comprises a body part which is removably attached to the body. Further, one of the two impulse spaces of the ai-5 is formed so as to be delimited by the percussion piston and said body. The body may be, for example, a kind of replaceable cartridge or the like.

BRIEF DESCRIPTION OF THE DRAWINGS

Some embodiments are explained in more detail in the accompanying drawings, in which Figure 1 is a schematic and side elevational view of a rock drilling device capable of utilizing the percussion devices disclosed in the application; Fig. 3 is a schematic and side elevational view of an excavator provided with a breaker which can utilize the impactors disclosed in the application; Figure 4 is a simplified view of the steps and features associated with the impactor control; Figure 5a is a schematic and sectional view of an embodiment of the impactor. in which the cycle is controlled by a sleeve-like control valve, Fig. 5b is an enlarged view of a portion of the control valve of Fig. 5a, Fig. 6 is a schematic and sectional view of the impactor bodyweight

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Fig. 7 is a schematic and cut-away view of an embodiment of an impactor having two impulse blades and 30 rotations of my work controlled by a sleeve-like control valve,

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Fig. 8 is a schematic and exploded view of a percussion device, S wherein the control valve is a spool valve spaced from the percussion piston; Fig. 9 is a schematic and exploded view of a percussion valve; Fig. 11 is a schematic and sectional view of a percussion device having a plurality of shoulders of different size to form pressure lines from impulse states; between the piston and the control valve, Figs. 13 and 14 show schematically and in sectional views portions of some of the impactors in which the piston closes the impulse chamber from the impulse chamber, resulting in 15 closed and pressurized, Figures 15 and 16 schematically illustrate the principle of dimensioning the pressure surfaces of a control valve, Fig. 17 schematically and cut away an embodiment of an auxiliary impact device in which the control unit controls, by pressure information, and FIG. 18 is a schematic and cut-away view of an embodiment of another abnormal impact device, wherein the control unit controls, based on pressure information, an electric control valve directing the pressure medium directly to the stroke operating state of the impact piston. It has been attempted to denote like parts with like reference numerals in the figures.

Detailed Description of Some Embodiments

Fig. 1 shows a rock drilling device 1 comprising a movable platform 2 with one or more drill booms 3 mounted thereon.

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The rock boom 3 is provided with a rock drilling unit 4 comprising a feed beam 5, a rock drill machine 6 fitted to the feed beam 5 and a feed device 7 for moving rock rock V drill 6 in the striking direction A and B in the rock drilling unit 4. 30 or drill holes for reinforcements, for example, in rock formations.

Fig. 2 shows a rock drilling unit 4 comprising a rock drill machine 6 with a drill bit 9 attached to the drill bit 8 with a drill bit 10 at its outermost end. The rock drill machine 6 comprises a percussion device 35 11 for delivering impact pulses to the drill bit 8 At the same time, the rock drill 6 is fed by means of a feeder 7 towards the rock, whereby the blade pieces in the drill 10 break the stone and form a drill hole 13. Typically, the rock drill 6 also comprises a rotary device 14 with a drill bit 8 and The tool 9 can be rotated about its longitudinal axis. The rock drill machine 6 comprises a frame 15, which may be attached to a carriage 16 arranged to support the feed beam 5. The rock drill body 15 may have a space in which the impact device 11 and its associated components are arranged.

Fig. 3 shows an excavator 17 having a movable base 2 and a boom 3 provided with a breaker hammer 18. The breaker hammer 18 can be operated in mm. breaking boulders, rock, crust and the like. The breaker hammer 18 comprises a body 19 fitted with a percussion device 11 capable of delivering impact pulses to a tool 20 which, under the effect of the impact pulses, penetrates into the breakable material 12 and causes it to break.

The impactors shown in Figures 4 to 18 below, their various applications and combinations of applications can be used as impactors in rock drills and breakers such as those described above.

Figure 4 illustrates the steps associated with the impactor operation. The impactor is actuated by applying hydraulic pressure from the pump or a similar source of pressure along the pressure medium passages. The impactor may be provided with one or more starter valves for forcibly guiding the control valve to a predetermined position for actuating the impactor. The piston can also be moved to a predetermined position for starting. The pressure exerted on the working pressure surfaces of the percussion piston causes the percussion piston to make a reciprocating movement in accordance with its cycle. The control valve controls the supply of pressure fluid 25 to the pressure surfaces such that the movement of the percussion piston changes between the direction of impact and the return direction. The impulse edge in the impact piston closes the pressure connection from the impulse space around the piston, causing a sudden

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^ the increase in pressure, or pressure pulse, in the closing impulse state. This pressure pulse gives an initial impulse to the control valve changeover movement, i.e. the control valve is caused by the pressure pulse to change its position from one extreme position to another. | The impactor shall continue to operate as long as the pressure medium is applied to it.

Figures 5a and 5b show an embodiment of the impactor 11. The basic mechanical structure of the impact device 11 may be of the cartridge type. Such a 00 35 impact cartridge 24 may be arranged as a single assembled unit in a space formed in the body of a rock drill or breaker. However, when referring in this application to the percussion device 11, in addition to the percussion cartridge 24 shown in the figures, it also refers to a conventional structure consisting of a plurality of separate components and assembled into a percussion chamber in the rock breaker.

The body 25 of the impactor 11 may be a substantially tubular elongate body. At the end facing the direction of impact A, body 25 may have a first end sleeve 26 which may comprise one or more bearings 27 and one or more gaskets 28. Correspondingly, backward direction B end body 25 may have a second end sleeve 29 which may also comprise 10 bearings 30 and seals 31. Such end sleeves 26 and 29 are easy and quick to install and replace as needed. The portions between the seals 28, 31 and the bearings 27, 30 may communicate with leakage passages 32 to direct any leakage flows to the tank.

The impactor 11 comprises an elongated impact piston 33 having an impact surface 70 on the A side end of the impact 15, which strikes the drill bit or directly on the tool when the piston 33 makes a reciprocating movement in accordance with its rotation. The percussion piston 33 comprises portions 33a -33d of different diameters, the percussion piston 33 having working pressure surfaces 34a and 34b which can be subjected to pressure fluid pressure so that the percussion piston 33 moves in the desired direction of movement. The first working pressure surface 34a is in the first working pressure space 35, i.e. in the front state, which is continuously supplied with pressure fluid from the pressure conduit 36, whereby the stroke piston 33 is continuously subjected to a force during the cycle which tends to move the stroke piston 33 in the reverse direction B. The second working pressure surface 34b is in the second working pressure state 37, i.e. the so-called. in the rear space, which is connected to the stroke piston 33 for a stroke A to the pressure passage 38, and connected to the return passage B to the tank passage 39. The pressure fluid flow to and from the working pressure space 37 is controlled by the control valve 40;

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by means of an elongate sleeve-like piece disposed about the percussion piston 33 in the space formed in the body 25. When the control valve 40 30 moves in its stroke A to its left-hand or steer position, it g closes the pressure passage 38 and at the same time opens the tank passage 39. Similarly, when o) the control valve 40 moves from its left-hand control position back to the right the second working pressure surface 34b is dimensioned much larger than the first working pressure surface 34a, whereby the movements of the percussion piston 33 can be controlled simply by changing the pressure of the pressure acting in the second working pressure space 37. The position of the control valve 40 is changed relative to the position of the piston 33. Next, it will be discussed in more detail how the control valve 40 controls the cycle of the piston 33, i.e. the movement from the impact point to the rear pivot point and back.

The impact piston 33 has an impulse shoulder 41 on its outer periphery and the body 25 has a first shoulder 42 and a second shoulder 43. The shoulder 42 and 43 are located axially apart. The piston 33 and the body 25 delimit in the radial direction the annular impulse first impulse 44 and the reciprocal second impulse 45. The portion of the impulse spaces 10 44, 45 has a space 46 communicating with the pressure line 47.

The purpose of the impulse shoulder 41, the counter shoulder 42, 43 and the impulse spaces 44, 45 is to provide a pressure pulse when approaching the extreme position of the piston, which is used to change the position of the control valve 40 and consequently to change the movement direction of the piston 33.

15 The axial surfaces K1 and K2 of the impulse shoulder 41 define the impulse spaces 44, 45 in the axial direction as the piston 33 moves towards the impulse space. In Fig. 5a, the surface K1 reduces the volume of the impulse blade 44 as the piston 33 moves in the direction of impact A. The impulse blade 41 has an impact impulse edge S1 and a return impulse edge S2. When the impulse edge S1 arrives at the counter flange 42, it closes the pressure connection Y1 from the impulse state 44, after which the pressure medium can no longer move from the impulse state 44 to the intermediate state 46. The impulse state 44 becomes closed under pressure and a pressure pulse is formed. Similarly, during the return movement B, the second impulse edge S2 in the percussion piston 33 comes to the second counter-blade 43 and closes the pressure connection Y2, as a result of which the second impulse space 45 becomes a closed pressure state and a pressure pulse is formed.

5 The pressure pulse is transmitted from the first pulse state 44 to the first

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Correspondingly, the pressure pulse is transmitted from the second impulse space 45 through the second impulse channel 58 to the second control pressure surface 51 of the control valve 40. | By means of the impulse channels 58, 59, the pressure pulse is then actuated 51, 52. The pressure fluid flow in the impulse ducts 58, 59 is very small because they transmit only the pressure pulse and the initial excitation needed to change the position of the control valve 40. Not the total volume required by the movement of the control valve 40. The impulse channels 58, 59 may be bores made in the frame 25 or similar channels.

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In Fig. 5a, the control valve 40 is shifted backwards B to its extreme position where it is held by the forces acting on its control pressure surfaces until it receives an initial impulse from the first impulse passage 59 to change its position in the direction of stroke A. The pressure pulse 5 destabilizes the balance position of the control valve in the end position, after which the forces acting on its other control pressure surfaces can complete the change of the control valve position. The control valve 40 is influenced by its holding forces at its extreme positions, which ensure that the valve is continuously synchronized with the movements of the piston.

Fig. 5b is an enlarged view of a portion of the control valve 40 of Fig. 5a. The control pressure surface 51 is influenced by the pressure of the pressure line P as it communicates with the pressure line P via the pulse channel 58, impulse bar 45 and intermediate space 46. closed. Further, the tank channel 60 and the first holding channel 61 connected to the control circuit 15 of the control valve 40 are closed. The second holding channel 62 is open and its pressure acts on the holding surfaces 63 of the holding circuit and pushes the valve to the right. The right-acting retaining surface 63 of the valve 40 is thus subject to pressure, while the left-facing retaining surface 64 is depressurized. The valve 40 then remains in this position until its position is shaken by a pressure pulse from the second pulse channel 59, which acts on the control pressure surface 52. The valve 40 then receives a sudden force surge and moves slightly to the left with the pressure can complete the transfer of valve 40 to its left extreme position. When vent-25 brick 40 moves to the left, control pressure surfaces 63 engage tank tank 60. When valve 40 is in its left extreme position, pressure duct 38 is closed. The tank passage 39 is open, allowing pressure fluid to flow

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from the working pressure chamber 37 to the tank through the clearance 65 between the piston 33 and the pilot valve 40. The piston 33 begins its movement in the reverse direction B, and as it approaches its extreme position again, a second impulse space 45 forms a pressure | the pulse transmitted by the pulse channel 58 to the valve control pressure surface o) 51. The valve then moves under the effect of pressure in the reverse direction B, whereby the holding surface 64 engages the tank channel 39 and thereby closes the connection 6 to the control pressure surfaces 6. The pressure fluid acting on the channel 35 moves the valve 40 to its right extreme position.

Thus, the retaining circuit of the control valve 40 comprises at least retaining channels 61 and 62 and retaining surfaces 63 and 64. The retaining circuit holds the valve 40 in its extreme positions and, on the other hand, completes the displacement of the valve 40 after the valve has first been released. The impulse means are related only to the formation of this initial impulse.

Fig. 5b further illustrates a substitution pressure duct 66 which can be used to direct the pressurized fluid into an impulse state at the moment when the percussion piston reverses its movement direction and the pressure drops in the impulse state. The displacement pressure channel avoids the retardation of piston movement and cavitation in impulse-10 mode. Other applications disclosed in this application may also have substitution pressure ducts.

It should also be noted that the pressure ducts 38, 62, 66 and 61 may be affected by the normal impact pressure of the impactor 11.

The advantage of the embodiment according to Figures 5a and 5b is e.g. the fact that only a small amount of the pressurized fluid used to control the 15 control valves is introduced into the tank. This fact improves the impactor efficiency.

Fig. 6 shows an alternative construction for the fully hydraulically controlled impactor 11 shown in Figs. 5a and 5b. The control valve 40 is in its extreme right position where its control pressure surface 51 20 is pressurized from channel 67 and further through pulse channel 58, impulse space 45 When the pressure pulse formed in the first impulse space 44 is transmitted along the impulse passage 59 to the second control pressure surface 52, the valve 40 receives an initial movement to the left. Since the second control pressure surface 52 is dimensioned to be clearly larger in area than the en-25 first control pressure surface 51, the valve 40 moves further to the left. The pressure in the pressure channel 67 acts on the second control pressure surface 52 and moves the valve 5 to its extreme left. From pressure channel 67 to control pressure surface

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^ 52 the effective pressure holds the valve in this position until its position is again shaken by applying a new pressure pulse from the second pulse state 30 45. The pressure pulse acts on the first control pressure surface 51 and receives the valve | Iin 40 to move to the right. Then, the striking face A of the valve A is exposed to the pressure of the pressure duct 38 which, together with the force exerted on the pressure duct 67, exerts a movement of the valve 40 to the extreme position shown in the figure. For the control valve holding function ^ 35, the pressure surfaces may be dimensioned according to the principles set forth later in connection with Figs. 15 and 16.

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The percussion device 11 shown in Fig. 7 comprises a control valve 40 having a basic construction and operation similar to that shown in Figs. 5a and 5b. Thus, the valve 40 has mm. traction circuit and associated ducts and pressure surfaces. The construction shown in Fig. 7 differs from that shown in the preceding Figures at least in that the run-5 co 25 is two-piece and comprises a first body part 25a and a second body part 25b between which a connecting surface 69 is provided. two impulse blades 41a and 41b axially spaced apart. The diameter D1 of the impulse shoulder 41a is smaller than the diameter D2 of the reverse impulse shoulder 41b. The velocity of the Is-10 piston 33 in the stroke direction A is clearly greater than the velocity in the return direction B. The return impulse shoulder 41b can be dimensioned larger than the impact impulse shoulder 41a so as to compensate for the differential pressure pulse due to speed differences. Namely, the magnitude of the pressure pulse is proportional to the velocity of the piston and the area displaced by the pressure fluid of the impulse blade. If the pressure pulses generated in different directions are not compensated by the displacement areas of different magnitudes, the differential magnitude of the pressure pulses can be taken into account in the design of the control pressure surfaces of the control valve 40. Further, the compensation can be treated by appropriate dimensioning of the play.

In the embodiment shown in Fig. 7, the first counter-blade 42 is in the first body 25a and the second counter-blade 43 is in the second body 25b. This design allows the axial distance of the counter-blades 42, 43 to be varied, thereby affecting the moment when the position of the piston 33 is detected and the position 25 of the control valve 40 is changed. For example, spacers 69 may be disposed between the body members 25a, 25b, or the body members may be interconnected by a threaded joint, whereby they may be rotated infinitely towards each other and away from one another. In response

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By influencing the distance between the blades 42, 43, the stroke length of the stroke piston 33 and thus the stroke rate and stroke rate can be influenced.

Each impulse shoulder 41a, 41b of Figure 7 is provided with an impulse on the inside S1, S2 and on the surface K1, K2. The principle of pressure pulse formation is thus similar to that described above.

Fig. 8 shows an impact device 11 having pulse means 41, S1, S2, K1, K2, 44, 45 similar to the preceding figures for generating pressure pulses based on the position of the piston 33. The embodiment shown in Fig. 8 differs in that the control valve is a spindle valve 77, which is physically spaced from the impact piston 33. The spindle valve 77 may comprise its own body 78 or be formed on the body of the impactor. The spindle valve 77 comprises a mechanical guide slide 79, which may be an elongated sleeve-like member as shown in the figure, or alternatively it may be a pin-like guide member 5. The guide slider 79 has control stations where it directs the pressure fluid from the pressure duct 80 along the duct 57 to the working pressure chamber 37 and respectively away from the tank duct 81. The outer periphery of the guide slider 79 has guide pressure surfaces 51, 52 which Further, there is a holding circuit in connection with the guide slide, which comprises 10 holding channels 61, 62 and pressure surfaces 63, 64.

The basic construction and operation of the impactor 11 shown in Figure 9 corresponds to that shown in Figure 6. However, the embodiment of Fig. 9 differs from that shown in Fig. 6 in that it comprises a starter valve 82 shown in Fig. 6 in a situation where the pressurized duct 83 is not supplied with a pressurized fluid. In this case, the actuator valve 82 is not influenced by the control pressure, but the spring 84 has moved the valve 82 to the left position b. When the impact device 11 is actuated again, pressure fluid 83 is supplied to the pressure duct 83 by the actuator Then, the action of the impactor 11 is initiated and the impact piston 33 begins to make a reciprocating movement according to its cycle, under the control of the control valve 40. The actuator valve 82 returns to its normal operating position a after the pressure in the pressure conduit 83 has increased and the pressure has been applied through the control conduit 86 to the actuator valve 82. The actuator valve 25 82 is intended to ensure control valve 40 moves to a controlled position. The 5 channel Ps shown in the figure is connected to the pressure channel 83 at start-up and at startup

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^ after connected to tank T.

v The control duct 86 of the start valve 82 may include a choke 87 for controlling the pressure level at which the start valve 82 moves to the drive | ground a. The throttle 87 may be adjustable or may have a fixed setting, o) The control valve 40 may have a triggering area for controlling the valve to a forward position when the impactor is actuated. This area can also be used to adjust the stroke length. When the impactor is actuated thereafter, the pressure in the actuation area comprising the actuating area is increased by retracting the control valve. This results in an increase in stroke length and a decrease in stroke rate.

The following Figures 10-14 are intended to show that the formation of a pressure pulse can be accomplished in different ways, even though the basic idea 5 is the same.

The embodiment shown in Fig. 10 is of the same basic design and construction as those shown in the previous embodiments. The difference, however, is that the counter-blades 42 'and 43' are not narrow shoulders in the axial direction. When the impulse blade 41 protrudes into the impulse impeller 44 in the stroke direction A or the impulse space 45 in the return direction B, a pressure pulse is generated which triggers a change in the position of the control valve 40. The impulse lock closes when the control valve 40 changes position.

Fig. 11 shows a percussion device 11 with actuator valve 82 having a plunger 33 comprising a plurality of shoulders 33a-33h and an impulse 15 blade 41. In this case, the impulse blade 41 does not comprise pulse edges S1, S2, but is located in shoulders 33d and 33e. The pulse edges S1 and S2 at the extreme positions of the percussion piston 33 close the pressure connections Y1 and Y2 to the channels 71 and 72 to form closed impulse spaces 44, 45. The pressure pulses are transmitted along the impulse channels 58, 59 to the control valve 40. It is also possible to use the spindle valve 77 shown in Figure 8.

Fig. 12 shows a percussion device 11 in which the impact direction A has an annular impulse space 44 between the body 25 and the percussion piston 33. The impact piston has a first impulse shoulder 41a having an impulse edge S1 which closes the impulse bar 44. In the reverse direction B, there are different impulse means. A second im-25 pulse chamber 45 is formed in the annular space between the piston 33 and the sleeve-like control valve 40. The control valve 40 has an opposing shoulder 43 on the inner periphery and a second impulse shoulder 41b at the rear of the percussion piston 33,

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^ having an impulse edge S2 and a face K2. A pressure pulse formed in the second impulse space 45 directly affects the pressure surface 76 at the rear surface 30 of the control valve 40. There is a gap that is not visible between the portion 29 and the pressure surface 76. FIG. Figure 12 thus shows a combination of two different pulse generation principles. The pressure surfaces of the control valve 40 are dimensioned such that the control valve is influenced by the holding forces at its extreme positions, for example according to the principles shown in Figures 15 and 16 ^.

FIG. 13 shows, in a very simplified manner, two alternative ways of generating a pressure pulse. In the first alternative, the impulse shoulder 41 in the percussion piston 33 is provided with an impulse edge S1a which closes the pressure connection Y1a in the body 25. This creates a closed impulse space 44 and a pressure pulse which is transmitted along the impulse passage 59 to the control valve. In another alternative, the pressure connection Y1b is in the percussion piston 5 33. In this case, the impulse edge S1b is in connection with the channel or bore opening forming the pressure connection Y1b.

In the solution shown in Fig. 14, there is no impulse blade, but the impulse space 44 is limited axially by the face K1 of the impact piston portion 33c. Further, the impulse edge S1 is in the piston portion 33b. The Pai 10 pulse is formed when the piston 33 moves to the left in the pattern so that the pulse edge S1 bypasses the pressure connection Y1. In this case, the pressure medium can no longer pass from the pulse space 44 through this channel at pressures 75.

The principles shown in Figures 13 and 14 can be applied both in the impact direction A and in the return direction B.

Figures 15 and 16 show in more detail the principles of dimensioning the working pressure surfaces of the control valves 40 shown in Figures 6, 9, 11 and 12. As can be seen from the figures, the areas A1 and A2 of the control pressure surfaces 51 and 52 in the control valve 40 are dimensioned differently. Further, the areas A3, A4 20 and A5 of the pressure surfaces 68, 85 and 91 at the ends of the control valve 40 can be dimensioned differently.

The embodiment shown in Figures 15 and 16 relates to a solution in which a momentarily closed pressure state is formed during the stroke and return movement of the stroke piston and the pressure pulse generated therein is utilized to control the position of the control valve.

The operating principle of the control valve 40 shown in Figs. 15 and 16 differs e.g. 5a and 5b, since the valve 5 does not have separate pressure surfaces for generating the holding forces, but

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The control areas 51 and 52 and the pressure surfaces 68, v 85 and 91 at the ends of the valve are measured, which are dimensioned as described below. In the rear impact piston 30, the working pressure 37 varies during the cycle and this pressure variation is used | in the formation of the holding forces Fpjt0.

o) In Fig. 15, the control valve 40 is in a position where the rear working space 37 is connected to the tank pressure as the percussion piston is in reverse B movement. The control pressure surfaces 51 and 52 are affected by the impact pressure. The control pressure surface 00 35 nan 52 has a surface area A2 larger than the control pressure surface 51 surface 16 area A1. The control valve 40 is then actuated by a holding force Fpjt0 which holds the control valve 40 in the position shown in Figure 15.

Then, the magnitude of the holding force Fpjt0 acting on the control valve 40 can be calculated by the following formula: 5 f ', 0 = p (α, -α1) -γ · (α1-αι-α!) = Ρ aa, -t ^ (aa2-as), ΔΑι is the difference between the control pressure surfaces 51 and 52 and where ΔΑ2 is the difference between the surface areas A3 and A4 of the pressure surfaces 68 and 91 at the ends of the control valve 40.

Fig. 16 shows the position of the control valve 40 after the stroke piston has moved in a reversing direction B so close to the exchange position that the stroke piston in the stroke piston pushes into the impulse space 45 and causes a momentary pressure pulse. The pressure pulse is transmitted by the pulse channel 15 to the control pressure surface 51 of the control valve 40, whereby the control valve 40 is allowed to change its initial position, i.e. the valve receives a trigger from the pressure pulse. When the control valve 40 is in the position shown in Figure 16, the rear working space 37 is coupled to the pressure duct P, as a result of which the control valve 40 is subjected to a holding force Fpj0, which can be calculated as follows: P (A3 t) = P-OR (AA2- & Al) -or

To ensure that the holding forces Fpjt0 are always in the right direction, the areas can be determined as follows:

T

cvj Ml> - (Δ4 -As) ° where ΔΑι is the difference between the areas of the control pressure surfaces 51 and 52

V T

AA2> AA2 + j; A

i 30 where ΔΑ2 is the difference between the pressure areas at the ends of the control valve 40 in the rear working space 37.

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The advantage of the embodiment shown in Figures 15 and 16 is e.g. the fact that the design of the control valve can be remarkably simple. In addition, leakage from the control valve may be minor.

17

Further, Figures 17 and 18 of this application further show some impactors which differ from the solutions described above and defined in the independent claims. The idea is that at least one impulse state is provided with a pressure sensor for detecting a pressure pulse formed in the impulse state. The pressure information is transmitted from the sensor to the control unit which controls the control valve by means of the pressure information. The control valve may direct the pressure medium flow directly to and from at least one working pressure surface of the piston. Alternatively, the control unit controls, based on pressure information, at least one pre-control valve that controls the main control valve. The main control valve comprises a baffle to control the flow of pressure medium to and from one or more working pressure surfaces of the piston. The control unit can be equipped with a control strategy and its control parameters can be changed, which allows for a versatile control of the impactor.

In Figure 17, the impactor 11 is pre-controlled by an electrically controlled valve 15 21. The valve 21 is controlled by one or more control units 22 to which measurement data is transmitted from sensors 23a and 23b. The control unit 22 may be provided with a control strategy according to which it controls the action of the impactor taking into account the measurement information. Sensors can also be used to refer to other means of generating identification information, such as measuring devices, measuring elements, and sensors.

In the situation of Figure 17, the piston 33 is displaced in the striking direction A so that the impulse blade 41 is moved from the intermediate space 46 to the first counter blade 42. Then, the pulse edge S1 closes the pressure pulse Y1 to the first pulse 44, thereby producing a pressure pulse that can be identified by the pressure transducer 23a. Based on the measurement data of the pressure transducer 23a, the control unit 22 detects that the piston 33 has reached a predetermined position in the direction of impact A, on the basis of which it can issue a control command to the control line.

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17 along the electric pre-control valve 21 to change its position T so that the valve moves to the left of the position shown in Figure 17. Changing the position of the front control valve 21 causes the position of the control valve 40 | o) As the piston 33 moves in its retrograde direction B towards its extreme position, the pulse edge S2 closes the pressure connection Y2 to form a closed pressure space and a pressure pulse. The pressure pulse formed in the second impulse state 45 is detected by the second pressure sensor 23b, whereby it can be detected that the impact piston 33 has moved backwards B to a predetermined position. The control unit 22 18, in accordance with the measurement data and the control strategy assigned thereto, provides a control command along the control line 49 to the electrical pre-control valve 21 which changes its position to correspond to the situation shown in Figure 17.

The control valve 40 shown in Fig. 17 comprises an outer circumference of the Olak-5 50 and a first control pressure surface 51 and a second control pressure surface 52. The pressure acting on the control pressure surfaces 51, 52 can be varied by connecting the control pressure surfaces to either the pressure line P or the tank line T. In the situation of Fig. 17, the pilot control valve 21 is in position a, wherein the first control pressure surface 51 communicates with the pressure line P and the second control pressure surface 52 communicates with the tank line T, whereby the control valve 40 is moved backwards. When a pressure pulse is detected in the first impulse state 44, the control unit 22 moves the bias valve 21 to position b in the figure, whereby the second control pressure surface 52 engages with the pressure line 53 to the pressure line P and the first control pressure surface 51 from the position shown in the figure to the left with the result that the working pressure channel 38 closes and the tank channel 39 opens. Then, the pressure acting on the second working pressure surface 34b is reduced and the stroke-piston 33 reverses its direction of movement towards the return direction B. When the pressure pulse is detected from the second pulse state 45, the control valve 40 is moved back to its position shown in Fig. 17, controlled by the control unit 22 and the pre-control valve 21.

The impactor 11 shown in Figure 18 differs from the impactor of Figure 17 in that it has no sleeve-like control valve. In contrast, the control unit 22 is arranged to control the electric control valve 56, which in turn 5 is arranged to direct the pressurized fluid flows directly to the second operating pressure chamber.

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^ 37 thence along channel 57. In the situation illustrated in Figure 18, the control valve 56 is in a position where it directs the pressure fluid from the pressure line P at working pressures 37, whereby the piston 33 moves in the direction of impact A. When the impulse | the blade 41 aligns with the first counter blade 42, generates a weight pulse, which is recognized and upon which the control unit 22 gives a control command to change the position of the control valve 56. The control valve ^ 56 is then moved to the left in the figure, whereby it opens from the working pressure chamber 37 to the tank T. As a result, the piston 33 changes its direction of movement.

19

For ease of understanding, in the figures of this application, the channels associated with the tank are denoted by T. The channels in the pressure line are denoted by P.

For practical reasons, not all of the embodiments shown in the figures have been described in detail and in detail in the description of each figure, but the structures and operating principles shown in the various figures may be used to understand the embodiments shown in the other figures.

The front space 35 may also be a variable pressure mode, unlike the embodiments shown in the figures of this application. Thus, the control valve 40, 77 is adapted to control the supply of pressure fluid also to and from this space.

Further, the return end of the piston 33 may move, unlike the figures in this application, in a pressurized state, e.g.

The structure of the impactor 11 and the pressure medium channels leading thereto are illustrated in the figures of this application as a cartridge-like structure. Such an impact cartridge can be fitted into the space in the body of the rock drill or breaker hammer. Alternatively, the structure may be a conventional construct.

Many of the figures are denoted by H as a long edge or skirt, which is made possible by the construction of the invention. Due to such a long sealing surface, leaks between the percussion piston 33 and the body 25 can be minor. The efficiency of the impactor 11 is then good.

In this application, the term "trigger" is used to describe that the pressure pulse gives an initial impulse or initiates a change in the position of the control valve. The pressure pulse thus triggers the event-5 pattern, causing the control valve to move to a position that causes

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^ change of direction of movement of the piston.

The pressure pulse is a sudden, impulse-like pressure having a pressure greater than the base pressure and having a short duration. With such pressure | however, a pulse can bring about a change in the state of the state, even if I do not use another pressure and press the surfaces to make the change itself.

^ In some cases, the features disclosed in this application may be used as such, despite other features. On the other hand, the features disclosed in this application may be combined, if necessary, to form different combinations.

The drawings and the description related thereto are intended only to illustrate the idea of the invention. The details of the invention may vary within the scope of the claims.

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Claims (15)

A rock-breaking device impact device, which is a pressure medium and is adapted to deliver impact pulses to a rock-breaking tool, and which impact device (11) comprises: 5 a body (25); an impact piston (33) adapted to move reciprocally in the impact direction (A) and in the return direction (B) in the axial direction when the pressure medium acts on its working pressure surfaces (34a, 34b); at least one pressure-controlled mechanical control valve (40, 77) having positions for guiding the pressure medium to act on and out of at least one working pressure surface (34b) of the piston (33), and the control valve having pressure surfaces is adapted to move between its extremities; At least one impulse valve (44, 45) which is an annular space around the cam (33); at least one surface (K1, K2) in the impact piston (33) defining an impulse space (44, 45) in the axial direction, reducing the volume of the impulse as said surface moves towards the impulse space; And wherein one of the impulse spaces (44, 45) has at least one first pressure connection (58, 59) on at least one pressure surface of the control valve; and at least one other pressure connection (Y1, Y2) of the impulse state (44, 45); at least one impulse edge (S1, S2) 25 in the percussion piston (33) for closing said second pressure connection (Y1, Y2), whereby the impulse space tulee becomes closed under pressure and a pressure pulse is formed; δ and wherein the pressure pulse acts via a first pressure connection ό on the control valve (40, 77) and gives it an initial momentum towards the adjoining extreme position; 30 characterized in that the impulses (44, 45) are delimited by the piston (33) and the body (25) is-σ> viewed in the radial direction; and tn that the first pressure connection comprises at least one pulse channel (58, 59) in the body (25). CVJ Impact device according to claim 1, characterized in that the control valve (40, 77) is located away from the impulse space (44, 45). Impact device according to Claim 1 or 2, characterized in that the impact device (11) comprises a first impulse valve (44) in the direction of impact (A) of the impact piston (33), the impulse being formed giving the control valve (40, 77) an initial impulse , which causes the piston to move backwards (B). Impact device according to one of the preceding claims, characterized in that the impact device (11) comprises a first impulse valve (44) in the impact direction (A) and a second impulse valve (45) in the reverse direction (B), wherein the impulse spaces (44) , 45) the resulting pressure pulses give the control valve (40, 77) an initial boost at both of its extreme positions. Impact device according to one of the preceding claims, characterized in that the body (25) comprises a body part which is removably attached! a body; and that the impulse (44, 45) has a boundary piston (33) and a body portion 20 in a mass state. Impact device according to any one of the preceding claims, characterized in that the control valve (40) is a sleeve-like body disposed about the impact piston (33) at an axial distance from the impulse chamber (44, 25 45). The impact device according to any one of claims 1 to 5, characterized in that the control valve is a spool valve (77) comprising a mechanical control slide (79); and 30 that the guide slide (79) is located separate from the percussion piston (33) and the impulse space (44, 45). No) The impact device according to any one of the preceding claims, characterized in that the action of the pressure pulse on the control valve (40, 77) ceases when the control valve reaches its new extreme position; and that the change of control valve actuation activates the holding force, regardless of the stroke of the piston, which holds the control valve at the new extreme position until the next change of moment. A method for controlling the impactor of a rock-breaking device if, in method 5, the pressure medium is controlled by at least one pressure (34a, 34b) in and out of the impact piston (33) via at least one pressure-controlled mechanical control valve (40, 77). cycle control; Moving the control valve (40, 77) between its extreme positions relative to the position of the impact piston (33); generating a pressure pulse during movement of the piston (33) by closing the pressure connection (Y1, Y2) from the at least one impulse space (44, 45) surrounding the piston by means of the piston (33); and 15, transmitting a pressure pulse from the impulse space (44, 45) to at least one pressure surface of the control valve (40, 77), ) and the body (25), and transmitting a pressure pulse from the pulse space (44, 45) in the pulse channel (58, 59) on the body (25) to the control valve (40, 77) located at a distance from the pulse space (44, 45). A method according to claim 9, characterized in that an impact device (11) is provided having impulse spaces (44, 45) in the impact direction (A) and in the return direction (B); and transmitting, from the impulse states (44, 45), the pressure pulses to the pressure surfaces of the control valve (40, v 77) to provide an initial impulse of changeover at each of the two extreme positions of the control valve. Method according to claim 9 or 10, characterized in that the closing of the impulse valve (44, 45) is released before the control valve (40, 77) reaches its new extreme position, whereby the effect of the pressure pulse on the control valve ceases ; activating a holding pressure to act on at least one pressure surface of the control valve, independent of the displacement of the control valve (40, 77) and independently of the stroke of the percussion piston; and holding the control valve at the new extreme position under holding pressure until the next instant of change. Method according to one of the preceding claims 9 to 11, characterized in that the control valve (40, 77) is continuously actuated by holding forces during the stroke of the impact piston, so that the control valve (40, 77) tends to maintain its position at both its extreme positions; transmitting a pressure pulse from the impulse space (44, 45) to the control valve (40, 77); allowing a pressure pulse to act on at least one pressure surface (51, 52) of the control valve (40, 77), wherein the control valve (40, 77) is momentarily actuated by a force which deflects the control valve (40, 77) from its extreme position; and completing the movement of the control valve (40, 77) under the influence of the holding forces. A method according to any one of claims 9 to 12, characterized in that 20 pressure is applied to the at least one pressure surface of the control valve (40, 77) to influence the movement velocity of the control valve in the control direction affecting reverse movement (B) of the piston (33); and adjusting the stroke length of the stroke piston (33) by influencing the movement speed of the control valve (40, 77) in the said manner. Method according to one of the preceding claims 9 to 13, characterized in that the control valve (40, 77) controls a higher velocity of the impact piston (33) v in the direction of impact (A) as compared to the return direction (B); and 30 are provided on the control valve (40, 77) for displacement due to pressure pulse the magnitude of the force independent of the difference in motion between the piston (33), o) A method according to any one of claims 9 to 14, characterized in that the control valve (40, 77) is forced-controlled by means of the actuator valve (82) to a predetermined end position to initiate a new cycle of the piston (33). .