Percussion apparatus with pressure regulating device

Abstract

To provide a percussion apparatus including a pressure regulating device having a biasing element which allows a user to easily set a prestress without a risk of environmental pollution of the percussion apparatus.SOLUTION: A percussion apparatus includes: a pressure regulating device (16) comprising a regulating cylinder (17); a connecting channel (23) opening into the regulating cylinder (17); a pressure regulating slider (18) mounted movable in translation within the regulating cylinder (17) and delimiting, with the regulating cylinder (17), a connecting passage (24) having a passage sectional area which varies according to a regulating position occupied by the pressure regulating slider (18); a biasing element (26) configured to exert a prestress on the pressure regulating slider (18); and a prestress setting device (27) configured to set a prestress exerted by the biasing element (26) on the pressure regulating slider (18).SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a striking device, and more particularly to a hydraulic striking device provided with a pressure regulating device.

Background Art

[0002] In a known manner, a striking device includes a main body defining a piston cylinder, a striking piston attached to be reciprocable within the piston cylinder and configured to strike a tool during each operating cycle of the striking device, a first control chamber defined by the striking piston and the piston cylinder and connected so as not to be separated from a high-pressure fluid supply circuit, a second control chamber defined by the striking piston and the piston cylinder and opposite to the first control chamber, a control distributor configured to alternately control the reciprocating motion along the striking motion and the return motion of the striking piston within the piston cylinder, the control distributor being configured to alternately connect the second control chamber to a high-pressure fluid supply circuit and a low-pressure return circuit, a pressure regulating device configured to adjust an operating pressure of the striking device, also called an inlet pressure or a supply pressure, to a predetermined value, and has

[0003] With such a pressure regulating device, it is possible to ensure that the striking piston strikes the tool at a predetermined collision speed, that is, with a predetermined collision energy, in each operating cycle of the striking device.

[0004] Such a pressure regulating device includes, for example, an adjustment cylinder defined by the main body, a connection passage connected to the control distributor and opening into the adjustment cylinder, the connection passage being configured such that the control distributor connects the connection passage to the second control chamber during the return motion of the striking piston, A pressure adjustment slider is mounted so as to be movable in the translational direction within an adjustment cylinder and configured to take on multiple adjustment positions that are offset from each other in the translational direction, wherein the pressure adjustment slider and the adjustment cylinder are configured to define a connecting passage whose cross-sectional area changes according to the adjustment position taken by the pressure adjustment slider, and this connecting passage is configured to fluidly connect a connecting passage to a low-pressure return circuit. A biasing element configured to apply prestress to a pressure adjustment slider and bias the pressure adjustment slider to one of the plurality of adjustment positions where the cross-sectional area of ​​the connecting passage is minimized, It is equipped with.

[0005] To make the performance of the striking device adjustable, it is known that the prestress exerted by the biasing element on the pressure adjustment slider is set using a shim washer introduced into the adjustment cylinder. By adding or removing the shim washer in this way, the predetermined value at which the operating pressure is adjusted can be changed, and consequently, the impact velocity of the striking piston can be changed. [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] However, adding or removing shim washers to set the aforementioned prestress requires removing the shut-off plug to access the adjustment cylinder, which in turn requires opening the hydraulic circuit. This results in a large amount of hydraulic oil being discharged, and depending on the environment in which this operation is performed, contamination may occur if this hydraulic oil is not sealed.

[0007] The present invention aims to improve upon this drawback.

[0008] Therefore, the fundamental technical problem of the present invention is to provide a striking device having a pressure adjustment device equipped with a biasing element that eliminates the risk of environmental pollution of the striking device and allows the user to easily set its prestress. [Means for solving the problem]

[0009] For this purpose, the striking device according to the present invention The main body defines the piston cylinder, A striking piston is displaceably mounted to reciprocate within a piston cylinder and configured to strike a tool during each operating cycle of the striking device, A first control chamber defined by a striking piston and a piston cylinder, the first control chamber being connected to a high-pressure fluid supply circuit in a manner that prevents separation, A second control chamber is defined by a striking piston and a piston cylinder, and is opposite (paired with) the first control chamber. A control distributor configured to control the reciprocating motion along the striking and return motion of a striking piston within a piston cylinder, wherein the control distributor is configured to alternately connect a second control chamber to a high-pressure fluid supply circuit and a low-pressure return circuit, A pressure regulating device configured to adjust the operating pressure of a striking device to a predetermined value, Equipped with, The pressure regulating device is For example, an adjustment cylinder provided on a support part defined by the main body or fixed to the main body, A connecting passage that opens into the adjustment cylinder and is configured to connect to a second control chamber during the return movement of the striking piston, A pressure adjustment slider is mounted within an adjustment cylinder so as to be able to move in the translational direction and is configured to take on multiple adjustment positions that are offset from each other in the translational direction, wherein the pressure adjustment slider and the adjustment cylinder are configured to define a connecting passage whose cross-sectional area changes according to the adjustment position taken by the pressure adjustment slider, and the connecting passage is configured to fluidly connect the connecting passage to a low-pressure return circuit. A biasing element configured to apply prestress to a pressure adjustment slider and bias the pressure adjustment slider to the adjustment position in which the cross-sectional area of ​​the passage is minimized among multiple adjustment positions, Equipped with, The pressure regulating device has a prestress setting device configured to set the prestress applied to the pressure regulating slider by a biasing element, and the prestress setting device is A closing plug configured to close the open end of the adjustment cylinder, for example, in a removable manner, An operating member positioned within an adjustment cylinder and configured to cooperate with a biasing element, the operating member being displaceable in a displacement direction substantially parallel to the translational direction, A setting member is mounted to an operating member so as to be rotatable around a rotation axis, comprising, for example, a generally cylindrical setting part that is accessible from outside the striking device and is configured to be rotationally driven by a user, and a drive part that is located inside an adjustment cylinder and is mechanically connected to the operating member, wherein the setting member has a passage opening configured such that a closing plug allows the setting part to be accessed from outside the striking device, Equipped with, The setting member and the operating member are configured such that rotation of the setting member in a first rotational direction around the rotation axis causes displacement of the operating member toward the pressure adjustment slider, increasing the prestress applied to the pressure adjustment slider by the biasing element, and rotation of the setting member in a second rotational direction opposite to the first rotational direction around the rotation axis causes displacement of the operating member toward the pressure adjustment slider, decreasing the prestress applied to the pressure adjustment slider by the biasing element. The pressure adjustment device has an indexing mechanism configured to set each of a plurality of angular index positions relative to the setting member, where the setting member takes a stable angular position relative to the operating member. It is characterized by the following:

[0010] By configuring the pressure adjustment device for the striking device according to the present invention in this way, the user can easily set the prestress applied by the biasing element by rotating the setting member from outside the striking device, that is, without opening the hydraulic circuit and therefore without risking contamination of the area around the striking device.

[0011] Further, the striking device may have one or more of the following features, either alone or in combination.

[0012] According to an embodiment of the present invention, a connection passage is connected to a control distributor, and the control distributor is configured to connect the connection passage to a second control chamber during the return movement of the striking piston.

[0013] According to an embodiment of the present invention, the biasing element has a first end configured to cooperate with the actuating member, for example, to abut against the actuating member, and a second end configured to cooperate with the pressure adjustment slider, for example, to abut against the pressure adjustment slider.

[0014] According to an embodiment of the present invention, the actuating member is slidably mounted in the displacement direction.

[0015] According to an embodiment of the present invention, the actuating member has a preferably annular seat against which the first end of the biasing element abuts.

[0016] According to an embodiment of the present invention, the biasing element is a compression spring, the first end of which abuts against the actuating member and the second end of which abuts against the pressure adjustment slider.

[0017] According to an embodiment of the present invention, the setting member has an annular stop surface configured such that the actuating member abuts thereon, and the annular stop surface is configured to limit the displacement movement of the actuating member in contrast to the pressure adjustment slider.

[0018] According to an embodiment of the present invention, the number of angular index positions is two to eight, preferably four to eight, for example, six.

[0019] According to an embodiment of the present invention, the passage opening has a first end opening into the adjustment cylinder and a second end opening outside the striking device.

[0020] According to an embodiment of the present invention, at least a part of the setting portion extends into the passage opening.

[0021] According to one embodiment of the present invention, the closing plug has a closing portion having an outer surface on which the second end of the passage opening is open. Advantageously, the setting portion is flush with the outer surface of the closing portion or recessed from the outer surface of the closing portion. However, according to one modification of the embodiment of the present invention, the setting portion may protrude from the outer surface.

[0022] According to one embodiment of the present invention, the passage opening extends coaxially with the axis of rotation.

[0023] According to one embodiment of the present invention, the locking plug is fastened to the main body, for example, by screw fastening, and is configured so as not to move relative to the main body.

[0024] According to one embodiment of the present invention, the indexing mechanism has a plurality of index recesses provided on one of the closing plug and the setting member and distributed around the rotation axis, and at least one index protrusion provided on the other of the closing plug and the setting member and configured to cooperate with one of the index recesses when the setting member takes on each angular index position.

[0025] According to one embodiment of the present invention, the indexing mechanism has a plurality of indexing protrusions distributed around a rotation axis.

[0026] According to one embodiment of the present invention, at least one index protrusion is formed by an index ball provided on a closing plug or setting member and mounted inside a receiving cavity defined inward by a spherical portion.

[0027] According to one embodiment of the present invention, the setting member is displaceable by translational motion in a direction substantially parallel to the displacement direction with respect to the closing plug, and the biasing element is configured to hold the setting member in contact with the closing plug. Therefore, the force applied to the setting member by the biasing element and the effect of the cam between the closing plug and the setting member prevent adjustment defects caused by vibrations generated in the striking device.

[0028] According to one embodiment of the present invention, the closing plug constitutes a cam, and the setting member constitutes a cam follower.

[0029] According to one embodiment of the present invention, the setting member has a support portion, such as a support flange, which is located between the setting portion and the drive portion in the axial direction and is configured to abut against the closing plug.

[0030] According to one embodiment of the present invention, the closing plug is generally cylindrical and has an internal guide surface configured to guide the setting member in rotational and translational movements.

[0031] According to one embodiment of the present invention, the support portion has an annular stopping surface.

[0032] According to one embodiment of the present invention, the shut-off plug has a tubular fastening portion fixed within the adjustment cylinder, and the operating member is mounted within the fastening portion so as to be displaceable, for example, slidable.

[0033] According to one embodiment of the present invention, the operating member has a first spline extending in the direction of displacement, and the closing plug has a second spline extending in the direction of displacement and configured to cooperate with the first spline provided on the operating member, and the first spline and the second spline are configured to guide the operating member in translational motion in the direction of displacement.

[0034] According to one embodiment of the present invention, the second spline is provided on the inner surface of the fastening member.

[0035] According to one embodiment of the present invention, the locking plug comprises a plug body and, for example, an annular internal insert disposed within the plug body and fixed to the plug body, the internal insert being interposed between the plug body and the setting member, and an index recess or at least one index protrusion being provided on the internal insert.

[0036] According to one embodiment of the present invention, the internal insert is interposed between the plug body and the support portion.

[0037] According to one embodiment of the present invention, the drive unit has a screw drive rod extending substantially parallel to the direction of displacement, and the actuator has an axial screw hole configured to cooperate with the screw drive rod.

[0038] According to one embodiment of the present invention, a pressure adjustment slider, a setting member, and an operating member are arranged substantially coaxially.

[0039] According to one embodiment of the present invention, a pressure regulating slider has an annular groove that is fluidly connected to a connecting passage so as not to be separated, and the annular groove has an annular edge configured to form at least a portion of the connecting passage.

[0040] According to one embodiment of the present invention, the pressure regulating device comprises a first regulating chamber defined by a pressure regulating slider and an regulating cylinder and fluidically connected to a high-pressure fluid supply circuit in such a way as not to be separated, and a second regulating chamber defined by a pressure regulating slider and an regulating cylinder and fluidically connected to a low-pressure return circuit in such a way as not to be separated, and the connecting passage is configured to fluidly connect the connecting passage to the second regulating chamber.

[0041] According to one embodiment of the present invention, a biasing element and an operating member are arranged in a second adjustment chamber.

[0042] According to one embodiment of the present invention, the second adjustment chamber is opposite (paired with) the first adjustment chamber.

[0043] According to one embodiment of the present invention, the first surface of the pressure adjustment slider is located in the first adjustment chamber, and the second surface of the pressure adjustment slider, opposite to the first surface, is located in the second adjustment chamber.

[0044] According to one embodiment of the present invention, the prestress setting device includes, for example, setting marks provided on a fixed reading section provided on the main body or a closing plug, each of which corresponds to a setting mark corresponding to each angular index position (and therefore to each prestress value applied to the pressure adjustment slider by the biasing element), and reading marks associated with the setting marks and provided on the setting section.

[0045] According to one embodiment of the present invention, the pressure adjustment device has a setting member, for example, a stop element, such as an annular stop element, which is fixed to a drive unit and configured to limit the displacement movement of an operating member toward a pressure adjustment slider.

[0046] According to one embodiment of the present invention, the closing plug has an annular internal groove extending around a setting portion, and a seal disposed within the annular internal groove and configured to cooperate with the setting portion. The seal may be provided with, for example, an annular sealing lip configured to cooperate with the setting portion.

[0047] According to one embodiment of the present invention, the shut-off plug and the operating member form an annular housing that receives the first end of the biasing element.

[0048] According to one embodiment of the present invention, the closing plug has an annular outer groove provided on and extending around the fastening portion, and an annular seal disposed within the annular outer groove and configured to cooperate with the body of the striking device. The annular seal can be, for example, an O-ring.

[0049] In any case, the present invention will be fully understood by the following description with reference to the attached schematic diagrams, which illustrate several embodiments of this striking device as non-limiting examples. [Brief explanation of the drawing]

[0050] [Figure 1] Figure 1 is a schematic longitudinal cross-sectional view of a hydraulic impact device according to the first embodiment of the present invention. [Figure 2]Figure 2 is an enlarged longitudinal cross-sectional view of the pressure adjustment device of the hydraulic impact device shown in Figure 1, and shows the pressure adjustment slider in the first adjustment position. [Figure 3] Figure 3 is an enlarged longitudinal cross-sectional view of the pressure adjustment device shown in Figure 2, with the pressure adjustment slider in the second adjustment position. [Figure 4] Figure 4 is an enlarged partial longitudinal cross-sectional view of the pressure regulating device of a hydraulic impact device according to a second embodiment of the present invention. [Figure 5] Figure 5 is a perspective view of the shut-off plug of the pressure regulator shown in Figure 4. [Figure 6] Figure 6 is a perspective view of the operating member and setting member of the pressure regulating device shown in Figure 4. [Figure 7] Figure 7 is an enlarged partial longitudinal cross-sectional view of the pressure adjustment device of a hydraulic impact device according to a third embodiment of the present invention. [Figure 8] Figure 8 is an enlarged partial longitudinal cross-sectional view of the pressure regulating device of a hydraulic impact device according to a fourth embodiment of the present invention. [Modes for carrying out the invention]

[0051] Figures 1 to 3 show a striking device 2 according to the first embodiment of the present invention.

[0052] The striking device 2 comprises a body 3 that defines a piston cylinder 4, and a stepped striking piston 5 that is slidably mounted within the piston cylinder 4 to reciprocate. The striking piston 5 is configured to strike the upper end of a tool 6, which is slidably mounted within a bore 7 provided coaxially with the piston cylinder 4 within the body 3, during each operating cycle of the striking device 2.

[0053] The striking piston 5 and piston cylinder 4 define an annular first control chamber 8 and a second control chamber 9 that is opposite to the first control chamber 8 and has a larger cross-section than the first control chamber 8. The second control chamber 9 can be positioned, for example, above the striking piston 5.

[0054] The striking device 2 further includes a control distributor 11 arranged to alternately control the reciprocating motion of the striking piston 5 within the piston cylinder 4 along the striking and return motions. The control distributor 11 is configured to fluidly alternately connect the second control chamber 9 to the high-pressure fluid supply circuit 12 during the striking motion of the striking piston 5 and to the low-pressure return circuit 13 during the return motion of the striking piston 5.

[0055] The first control chamber 8 is connected to the high-pressure fluid supply circuit 12 via a supply passage 14 so as to cause the striking piston 5 to perform a striking action at each position of the control distributor 11, and then to return to its original position. The supply passage 14 can, advantageously, be connected to a hydraulic accumulator 15.

[0056] The striking device 2 further includes a pressure adjusting device 16 configured to adjust the operating pressure of the striking device 2 to a predetermined value.

[0057] As shown in detail in Figure 2, the pressure adjustment device 16 comprises an adjustment cylinder 17 defined by the main body 3 and a pressure adjustment slider 18 mounted within the adjustment cylinder 17 so as to be able to move in the translational direction D. The pressure adjustment slider 18 is configured to take on multiple adjustment positions that are offset from each other in the translational direction D.

[0058] The pressure adjustment slider 18 and adjustment cylinder 17 define a first adjustment chamber 19, which is fluidically connected to the high-pressure fluid supply circuit 12 via a passage 21 that fluidly communicates with the first control chamber 8, and a second adjustment chamber 22, which is opposite the first adjustment chamber 19 and fluidly connected to the low-pressure return circuit 13, without separation. Advantageously, the first surface of the pressure adjustment slider 18 is located within the first adjustment chamber 19, and the second surface of the pressure adjustment slider 18, opposite to the first surface, is located within the second adjustment chamber 22.

[0059] Furthermore, the pressure regulating device 16 includes a connecting passage 23 having a first end that is fluidly connected to the control distributor 11 and a second end that opens to the regulating cylinder 17. More specifically, the control distributor 11 is configured to connect the connecting passage 23 to the second control chamber 9 during the return movement of the striking piston 5.

[0060] Furthermore, the pressure adjustment slider 18 and the adjustment cylinder 17 are configured to define a connecting passage 24 whose cross-sectional area changes depending on the adjustment position taken by the pressure adjustment slider 18. The connecting passage 24 is configured to fluidly connect the connecting passage 23 to the second adjustment chamber 22 and, therefore, to the low-pressure return circuit 13. The pressure adjustment slider 18 has an annular groove 25 on its outer surface, which is provided with an annular edge 25.1 configured to fluidly connect to the connecting passage 23 so as not to separate and to form at least a portion of the connecting passage 24.

[0061] The pressure regulating device 16 further includes a biasing element 26, such as a compression spring, located within the second regulating chamber 22 and configured to apply prestress to the pressure regulating slider 18 and bias the pressure regulating slider 18 to an adjustment position where the cross-sectional area of ​​the connecting passage 24 is minimized, for example, zero or substantially zero. Therefore, when no high-pressure fluid is supplied to the striking device 2, the biasing element 26 acts a force on the pressure regulating slider 18 to close the connecting passage 24. When high-pressure fluid is supplied to the striking device 2, the high-pressure fluid is supplied to the first regulating chamber 19 through the passage 21, and a force opposite to the force acted by the biasing element 26 acts on the pressure regulating slider 18. As soon as this force exceeds the prestress force acted by the biasing element 26, the pressure regulating slider 18 translates toward the biasing element 26, and the cross-sectional area of ​​the connecting passage 24 increases.

[0062] The pressure regulating device 16 further includes a prestress setting device 27 configured to set the prestress acting on the pressure regulating slider 18 by a biasing element 26.

[0063] As shown in more detail in Figure 2, the prestress setting device 27 has a closing plug 28 configured to close the open end of the adjustment cylinder 17. The closing plug 28 is configured to be tightened to the main body 3 and fixed to the main body 3. According to the embodiments shown in Figures 1 to 3, the closing plug 28 has a tubular fastening portion 28.1 which is screwed into and fastened into the adjustment cylinder 17, for example, and a closing portion 28.2 configured to close the open end of the adjustment cylinder 17.

[0064] The closing plug 28 may have, for example, an annular outer groove provided on the fastening portion 28.1 and extending around the fastening portion 28.1, and an annular seal 290 disposed in the annular outer groove and configured to cooperate with the body 3 of the striking device 2. The annular seal 290 can be, for example, an O-ring.

[0065] The prestress setting device 27 further includes an actuator 29 configured to cooperate with the biasing element 26. The actuator 29 is located within the second adjustment chamber 22 and is movable in a displacement direction parallel to the translational direction D. Advantageously, the actuator 29 forms a pusher configured to apply a pressing force to the biasing element 26.

[0066] Advantageously, the actuator 29 is connected to the locking plug 28 by a guideway connection (slide connection). In particular, the actuator 29 is slidably mounted in the direction of displacement within a fastening portion 28.1 of the locking plug 28. For this purpose, the actuator 29 has a first spline 31 extending in the direction of displacement on its outer surface, and the fastening portion 28.1 has a second spline 32 extending in the direction of displacement on its inner surface and configured to cooperate with the first spline 31 provided on the actuator 29. The first and second splines 31 and 32 are configured to guide the translational movement of the actuator 29 in the direction of displacement.

[0067] As shown in Figure 2, the biasing element 26 has a first end that abuts against a first annular seat 33 provided on the actuating member 29, and a second end that abuts against a second annular seat 34 provided on the pressure adjustment slider 18. More specifically, the biasing element 26 applies one axial force to the actuating member 29 and an opposite axial force to the pressure adjustment slider 18. Advantageously, the shut-off plug 28 and the actuating member 29 form an annular housing that receives the first end of the biasing element 26.

[0068] According to the embodiments shown in Figures 1 to 3, the actuator 29 has an annular support portion 29.1 configured to support the first end of the biasing element 26, and an annular actuator portion 29.2 extending radially from one end of the support portion 29.1 located on the side of the shut-off plug 28. Advantageously, the actuator portion 29.2 has a first annular seat 33 and is configured to compress the biasing element 26 when the actuator 29 moves toward the pressure adjustment slider 18.

[0069] Furthermore, the prestress setting device 27 has a setting member 35 connected to the closing plug 28 by a sliding rotational connection. Thus, the setting member 35 is rotatably mounted relative to the operating member 29 around the rotation axis A, and is also capable of translational displacement relative to the closing plug 28 in a direction substantially parallel to the displacement direction. Advantageously, the pressure adjustment slider 18, the setting member 35, and the operating member 29 are arranged coaxially.

[0070] The setting member 35 has a setting section 36 that can be made overall cylindrical, for example, and is configured to be accessible from outside the striking device 2 and to be rotationally driven by the user. For this purpose, the closing section 28.2 has a passage opening 37 configured to allow the setting section 36 to be accessed from outside the striking device 2. The passage opening 37 advantageously includes a first end that extends coaxially with the rotation axis A and opens into the adjustment cylinder 17, and a second end that opens into the outer surface of the closing section 28.2. In the embodiments shown in Figures 1 to 3, at least a portion of the setting section 36 may extend within the passage opening 37 and be, for example, flush with the outer surface of the closing section 28.2 or set back from the outer surface of the closing section 28.2. However, in one modification of the embodiments of the present invention, the setting section 36 may protrude from the outer surface.

[0071] The setting member 35 further includes a drive unit 38 located within the second adjustment chamber 22 and mechanically connected to the operating member 29. The drive unit 38 is preferably connected to the operating member 29 by a helical connection. According to the embodiments shown in Figures 1 to 3, the drive unit 38 has a screw drive rod 39 extending coaxially with the rotation axis A, and the operating member 29 has an axial screw hole 41, which may extend, for example, along the entire length of the operating member 29 and be configured to cooperate with the screw drive rod 39. Advantageously, the biasing element 26 is configured to hold the setting member 35 in contact with the closing plug 28 by a helical connection between the operating member 29 and the setting member 35.

[0072] More specifically, the setting member 35 and the operating member 29 are configured such that rotation of the setting member 35 in a first rotational direction around the rotation axis A causes displacement of the operating member 29 toward the pressure adjustment slider 18 (and thus compression of the biasing element 26), increasing the prestress applied to the pressure adjustment slider 18 by the biasing element 26, and rotation of the setting member 35 in a second rotational direction opposite to the first rotational direction around the rotation axis A causes displacement of the setting member 29 toward the pressure adjustment slider 18 (and thus relaxation of the biasing element 26), decreasing the prestress applied to the pressure adjustment slider 18 by the biasing element 26.

[0073] In the embodiments shown in Figures 1 to 3, the setting member 35 has a support portion 42, such as a support flange, which is located axially between the setting portion 36 and the drive portion 38 and configured to abut against the closing plug 28. Advantageously, the support portion 42 includes an annular stop surface 43 into which the operating member 29 abuts. More specifically, the annular stop surface 43 is configured to restrict the displacement of the operating member 29 away from the pressure adjustment slider 18, i.e., the displacement of the operating member 29 toward the closing plug 28.

[0074] The pressure adjustment device 16 may have, in the second embodiment of the present invention shown in Figures 4 to 6, an annular stop element 44, for example, fixed to, for example, a drive unit 38 of the setting member 35 and configured to restrict the displacement movement of the operating member 29 toward the pressure adjustment slider 18. According to the embodiment shown in Figures 1 to 3, the drive unit 38 has a fastening screw hole 45 opening at one end of the drive unit 38 facing the pressure adjustment slider 18, and the stop element 44 is fastened to the setting member 35 by a press screw 46 cooperating with the fastening screw hole 45.

[0075] According to the embodiments shown in Figures 1 to 3, the shut-off plug 28 has an annular internal groove 47 extending around the setting portion 36 and a seal 48 disposed in the annular internal groove 47 and configured to cooperate with the setting portion 36. The seal 48 may be provided with, for example, an annular seal lip configured to cooperate with the setting portion 36.

[0076] Furthermore, the pressure regulating device 16 has an indexing mechanism 49 configured to set each of a plurality of angular indexing positions relative to the setting member 35, where the setting member 35 takes a stable angular position relative to the operating member 29. The number of angular indexing positions can be between two and eight, preferably between four and eight, for example, six.

[0077] According to the embodiments shown in Figures 1 to 3, the indexing mechanism 49 has a plurality of index recesses 51 provided on the closing portion 28.2 and distributed around the rotation axis A, and a plurality of index protrusions 52 provided on the support portion 42 and distributed around the rotation axis A. Each index protrusion 52 is configured to cooperate with the index recess 51 when the setting member 35 takes its respective angular index position. Therefore, the setting member 35 is connected to the closing plug 28 by a cam connection in which the closing plug 28 constitutes a cam and the setting member 35 constitutes a cam follower. Each index protrusion 52 may be integrated with the support portion 42 or attached to the support portion 42.

[0078] Furthermore, advantageously, the prestress setting device 27 is A fixed reading area, for example, setting marks (not shown) provided on the closing plug 28, with setting marks corresponding to each angular index position (and therefore each value of prestress applied to the pressure adjustment slider 18 by the biasing element 26), A reading mark (not shown) associated with a setting mark and provided on the setting unit 36, It may have.

[0079] To set the prestress applied to the pressure adjustment slider 18 by the biasing element 26, the user rotates the setting member 35 using a key suitable for insertion into, for example, a hexagonal marking provided on the setting unit 36, until the reading mark faces the setting mark corresponding to the desired prestress value. Since the operating member 29 is connected to the setting member 35 by a helical connection and to the closing plug 28 by a guideway connection, this rotation of the setting member 35 causes a translational motion of the operating member 29 relative to the closing plug 28 (towards the pressure adjustment slider 18 or the closing plug 18, depending on the direction of rotation). This translational motion of the operating member 29 allows the setting of the prestress applied to the pressure adjustment slider 18 by the biasing element 26.

[0080] Advantageously, each index recess 51 and / or each index protrusion 52 has a slope or curved surface to limit the torque required to overcome the resistance generated by the cam connection between the closing plug 28 and the setting member 35.

[0081] Figure 7 shows a striking device 2 according to a third embodiment of the present invention, which is fundamentally different from the embodiments shown in Figures 1 to 3, in that the locking plug 28 includes a plug body 281 and, for example, an annular internal insert 282 fixed to the plug body 281 and interposed between the plug body 281 and the support portion 42, and an index projection 52 is provided on the internal insert 282. Advantageously, the internal insert 282 is locked to the locking plug 28 by cooperating with the second spline 32.

[0082] Figure 8 shows a striking device 2 according to a fourth embodiment of the present invention, which is fundamentally different from the embodiments shown in Figures 1 to 3, in that each index protrusion 52 is formed by an index ball attached to each receiving cavity, which is provided on the setting member 35 and whose interior is defined by a spherical portion. By configuring the index mechanism 49 in this way, friction between the setting member 35 and the closing plug 28 is minimized, and consequently, wear on the setting member 35 and the closing plug 28 is minimized.

[0083] Naturally, the present invention is by no means limited to the embodiments described and illustrated merely as examples. In particular, modifications can be made without departing from the scope of protection of the present invention, either in terms of the configuration of various elements or by substitution with technical equivalents.

Claims

1. A striking device (2), a body (3) defining a piston cylinder (4); a striking piston (5) displaceably mounted for reciprocating movement within the piston cylinder (4) and configured to strike a tool (6) during each operating cycle of the striking device (2); a first control chamber (8) defined by the striking piston (5) and the piston cylinder (4), the first control chamber (8) being inseparably connected to a high-pressure fluid supply circuit (12); a second control chamber (9) defined by the striking piston (5) and the piston cylinder (4) and facing the first control chamber (8); a control distributor (11) configured to control the reciprocating movement of the striking piston (5) along a striking stroke and a return stroke within the piston cylinder (4), the control distributor (11) being configured to alternately connect the second control chamber (9) to the high-pressure fluid supply circuit (12) and to a low-pressure return circuit (13); a pressure adjusting device (16) configured to adjust the operating pressure of the impact device (2) to a predetermined value; Equipped with The pressure adjusting device (16) an adjusting cylinder (17); a connecting passage (23) opening into the adjusting cylinder (17) and adapted to be connected to the second control chamber (9) during the return movement of the striking piston (5); a pressure regulating slider (18) mounted within the adjusting cylinder (17) so as to be capable of translational movement in a translation direction (D) and configured to take a plurality of adjustment positions offset from one another in the translation direction (D), wherein the pressure regulating slider (18) and the adjusting cylinder (17) are configured to define a communication passage (24) whose cross-sectional area changes depending on the adjustment position taken by the pressure regulating slider (18), and the communication passage (24) is configured to fluidly connect the connecting passage (23) to the low-pressure return circuit (13); a biasing element (26) configured to apply prestress to the pressure adjusting slider (18) and bias the pressure adjusting slider (18) to an adjustment position where the cross-sectional area of ​​the communication passage (24) is minimized; Equipped with The pressure adjusting device (16) has a prestress setting device (27) configured to set a prestress applied to the pressure adjusting slider (18) by the biasing element (26), the prestress setting device (27) comprising: a closing plug (28) configured to close the open end of the adjusting cylinder (17); an actuating member (29) arranged in the adjusting cylinder (17) and adapted to cooperate with the biasing element (26), the actuating member (29) being displaceable in a displacement direction substantially parallel to the translation direction (D); a setting member (35) rotatably mounted around a rotation axis (A) relative to the actuating member (29), the setting member (35) comprising: a setting portion (36) accessible from outside the percussion device (2) and configured to be rotationally driven by a user; and a drive portion (38) disposed within the adjustment cylinder (17) and mechanically connected to the actuating member (29), the setting member (35) having a passage opening (37) configured so that the closing plug (28) makes the setting portion (36) accessible from outside the percussion device (2); Equipped with the setting member (35) and the actuating member (29) are configured such that a rotation of the setting member (35) about the rotation axis (A) in a first rotational direction causes a displacement of the actuating member (29) toward the pressure regulating slider (18) and increases the prestress applied by the biasing element (26) to the pressure regulating slider (18), and a rotation of the setting member (35) about the rotation axis (A) in a second rotational direction opposite to the first rotational direction causes a displacement of the actuating member (29) away from the pressure regulating slider (18) and decreases the prestress applied by the biasing element (26) to the pressure regulating slider (18), The pressure regulating device (16) has an indexing mechanism (49) configured to define a plurality of angular index positions for the setting member (35) at which the setting member (35) assumes a stable angular position relative to the actuating member (29). A striking device (2) characterized in that

2. The impact device (2) according to claim 1, The indexing mechanism (49) includes a striking device (2) having a plurality of indexing recesses (51) provided on one of the closing plug (28) and the setting member (35) and distributed around the rotation axis (A), and at least one indexing protrusion (52) provided on the other of the closing plug (28) and the setting member (35) and configured to cooperate with one of the indexing recesses (51) when the setting member (35) assumes each angular index position.

3. The impact device (2) according to claim 1 or 2, The striking device (2) is configured such that the setting member (35) is displaceable in a translational movement relative to the closing plug (28) in a direction substantially parallel to the displacement direction, and the biasing element (26) is configured to hold the setting member (35) in contact with the closing plug (28).

4. The impact device (2) according to claim 3, The setting member (35) has a support portion (42) located axially between the setting portion (36) and the drive portion (38) and configured to abut against the closing plug (28).

5. The impact device (2) according to claim 1 or 2, The closing plug (28) has a tubular fastening part (28.1) fixed in the adjusting cylinder (17), and the actuating member (29) is displaceably mounted in the fastening part (28.1) of the striking device (2).

6. The impact device (2) according to claim 1 or 2, The actuating member (29) has a first spline (31) extending in the displacement direction, the closing plug (28) has a second spline (32) extending in the displacement direction and configured to cooperate with the first spline (31) provided on the actuating member (29), and the first spline (31) and the second spline (32) are configured to guide the translational movement of the actuating member (29) in the displacement direction.

7. The impact device (2) according to claim 1 or 2, The driving part (38) has a threaded driving rod (39) extending substantially parallel to the displacement direction, and the actuating member (29) has an axially threaded hole (41) configured to cooperate with the threaded driving rod (39).

8. The impact device (2) according to claim 1 or 2, The impact device (2) has the pressure adjusting slider (18), the setting member (35) and the actuating member (29) arranged substantially coaxially.

9. The impact device (2) according to claim 1 or 2, The pressure regulating slider (18) has an annular groove (25) that is fluidly connected to the connecting passage (23) in a non-separate manner, and the annular groove (25) has an annular edge (25.1) that is configured to form at least a part of the communicating passage (24).

10. The impact device (2) according to claim 1 or 2, The pressure regulating device (16) comprises a first regulating chamber (19) defined by the pressure regulating slider (18) and the regulating cylinder (17) and inseparably fluidly connected to the high-pressure fluid supply circuit (12), and a second regulating chamber (22) defined by the pressure regulating slider (18) and the regulating cylinder (17) and inseparably fluidly connected to the low-pressure return circuit (13), and the communication passage (24) is configured to fluidly connect the connecting passage (23) to the second regulating chamber (22).

11. The impact device (2) according to claim 1 or 2, The pressure regulating device (16) has a striking device (2) having a stop element (44) fixed to the setting member (35) and configured to limit the displacement movement of the actuating member (29) towards the pressure regulating slider (18).

12. The impact device (2) according to claim 1 or 2, The connecting passage (23) is connected to the control distributor (11), and the control distributor (11) is configured to connect the connecting passage (23) to the second control chamber (9) during the return movement of the striking piston (5).

13. The impact device (2) according to claim 1 or 2, The closing plug (28) has an annular internal groove (47) extending around the setting portion (36), and a seal (48) disposed within the annular internal groove (47) and configured to cooperate with the setting portion (36).

14. A percussion device (2) according to claim 13, The seal (48) has an annular sealing lip configured to cooperate with the setting portion (36).

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