Rotary impact hydraulic drill provided with a shank having a connecting spline

Abstract

The rotary impact hydraulic drill (2) includes a body (3), a shank (13) having a female coupling spline and a male coupling spline, a striking piston (5) configured to strike the shank, a rotary drive device (18) configured to rotationally drive the shank, and a front abutment surface (23) configured to abut against the shank (13). The shank (13) includes an annular bearing flange (24) provided on the outer surface of the shank (13) and having an annular bearing surface configured to abut against the front abutment surface (23). The female and male coupling splines provided on the shank (13) each extend from the annular bearing flange (24) toward the striking piston (5).

Description

[Technical field]

[0001] The present invention relates to a rotary impact hydraulic drill, in particular for use in drilling installations. [Background technology]

[0002] The drilling installation comprises, in a known manner, a rotary percussion hydraulic drill slidably mounted on a slider and driving one or more drill bars, the end of which carries a tool called a cutting edge that comes into contact with the rock. The purpose of such a drill is generally to drill more or less deep holes so that explosives can be placed therein. The drill is therefore the main element of the drilling installation, which, on the one hand, provides a rotational and percussion setting through the drill bar to the cutting edge so as to penetrate the rock, and, on the other hand, supplies the injection fluid so as to extract the fragments from the drilled hole.

[0003] The rotary impact hydraulic drill, more particularly, comprises, on the one hand, a striking device having a striking piston driven by one or more hydraulic fluid flows coming from a main hydraulic supply circuit and configured to strike a shank coupled to the drill bur in each operating cycle of the drill, and, on the other hand, a rotary drive device configured to rotate the shank and the drill bur and provided with a hydraulic rotary motor. Summary of the Invention [Problem to be solved by the invention]

[0004] The rotary drive device in particular comprises a coupling member including male and female coupling splines arranged around the shank and rotatably coupled to female and male coupling splines, respectively, on the outer surface of the shank, the male and female coupling splines extending substantially parallel to the elongated axis of the shank and angularly offset from one another relative to the elongated axis of the shank.

[0005] When the cutting edge becomes jammed against rock, the rotary impact hydraulic drill is retracted until the front end of the male coupling spline on the shank abuts against a front abutment surface on a front abutment member fixed to the body of the rotary impact hydraulic drill.

[0006] Next, in an attempt to unlock the tool, the rotary drive and / or the striking device can be actuated to rotary drive the shank and / or impact the shank with the striking piston.

[0007] Such actuation of the rotary drive and / or striking device induces rotational friction against the front abutment surface of the male coupling spline on the shank and / or axial impact against the front abutment surface of the male coupling spline on the shank.

[0008] However, such repeated axial impacts and rotational friction are likely to cause rapid wear of the male coupling splines on the shank, necessitating frequent replacement of the shank, and furthermore, such wear of the male coupling splines generates chips that can stick between different moving parts of the rotary impact hydraulic drill and thus damage the rotary impact hydraulic drill.

[0009] The present invention aims to remedy all or part of these drawbacks.

[0010] The technical problem underlying the present invention is therefore to provide a rotary impact hydraulic drill which is compact, yet simple in construction, economical and reliable. [Means for solving the problem]

[0011] To this end, the invention relates to a rotary impact hydraulic drill, comprising a body, a shank intended to be coupled to at least one drill bur equipped with a tool, a striking piston slidably mounted inside the body along a striking axis and configured to strike the shank, a rotary drive configured to drive the shank in rotation about an axis of rotation substantially coinciding with the striking axis, and a front abutment surface fixed relative to the body, the shank comprising a coupling part with female and male coupling splines angularly offset from one another relative to an extension axis of the shank, the rotary drive comprising a coupling member arranged around the shank, the coupling member comprising male and female coupling splines rotatably coupled to the female and male coupling splines of the shank, respectively, the front abutment surface being annular and extending around the shank, the shank being adapted to drive the shank in rotation about an axis of rotation substantially coinciding with the striking axis, the shank includes an annular bearing flange having an annular bearing surface provided on an outer surface of the shank and configured to abut the front abutment surface so as to limit a forward displacement stroke of the shank, the shank including an annular bearing flange having an annular bearing surface provided on an outer surface of the shank and configured to abut the front abutment surface, the female and male coupling splines on the shank each extend from the annular bearing flange in the direction of the striking piston, each female coupling spline on the shank includes a bottom surface and a connection surface connecting each bottom surface to the annular bearing flange and extending forward away from the extension axis of the shank, the connection surface of each female coupling spline on the shank being at least partially formed by a curved concave surface extending substantially in the extension direction of each female coupling spline and having a radius of curvature smaller than a radial height of each male coupling spline on the shank.

[0012] The presence of such an annular bearing flange in front of the female and male coupling splines on the shank makes it possible to avoid contact between the front abutment surface and the male coupling splines on the shank, thus maintaining the integrity of the shank.

[0013] Furthermore, the presence of an annular bearing surface on the annular bearing flange ensures a relatively large contact surface between the front abutment surface and the annular bearing flange and therefore a better distribution of the impact and / or friction forces exerted by the shank against the front abutment surface.

[0014] The specific configuration of the rotary impact hydraulic drill according to the present invention therefore makes it possible to provide a substantially increased service life for the shank and significantly reduce the periods of immobilization of the drill for replacing the shank and the risk of damage to the drill which may affect the safety of the user.

[0015] Furthermore, if the male coupling splines on the shank extend directly from the annular bearing flange, the axial length of the shank is not affected by the presence of the annular bearing flange, which makes it possible to obtain a compact rotary impact hydraulic drill. The fact that each female coupling spline on the shank comprises a connection surface formed at least in part by a curved concave surface having a small radius of curvature makes it possible to further reduce the axial length of the shank and therefore to further improve the compactness of the rotary impact hydraulic drill.

[0016] The specific configuration of the connection surface of each female coupling spline provided on the shank also makes it possible to avoid the presence of sharp angles which may induce high stresses on the shank during operation of the drill and thus induce rupture of the shank.

[0017] The rotary impact hydraulic drill may also have one or more of the following features, either alone or in combination:

[0018] According to one embodiment of the invention, the female and male coupling splines on the shank extend substantially parallel to the axis of extension of the shank.

[0019] According to one embodiment of the invention, the connection surface of each of the female coupling splines on the shank is entirely defined by a respective curved concave surface.

[0020] According to an embodiment of the invention, the annular bearing flange has a maximum outer diameter equal to or greater than the outer diameter of the connection part. Such a configuration of the connection part makes it possible to reduce the cross section of the shank at the connection part and thereby the cross section of the connection member while maintaining a large protective surface. These arrangements therefore make it possible to reduce the footprint of the rotary impact hydraulic drill according to the invention.

[0021] According to one embodiment of the invention, the front end of each female spline on the shank is located on the annular bearing flange. According to a variant of the invention, the front end of each female spline on the shank may be adjacent to the annular bearing flange.

[0022] According to one embodiment of the invention, a forward end of each male coupling spline on the shank abuts the annular bearing flange.

[0023] According to one embodiment of the invention, each of the male coupling splines on the shank includes an upper surface extending from the annular bearing flange.

[0024] According to one embodiment of the invention, for each male coupling spline on the shank, the radial distance between the extension axis of the shank and the upper surface of the male coupling spline is substantially constant along the male coupling spline.

[0025] According to an embodiment of the invention, the radius of curvature of each of the curved concave surfaces is smaller than 15 mm, for example smaller than 10 mm. Such a value of the radius of curvature of the curved concave surface of each female coupling spline provided on the shank makes it possible to reduce the length of the connection between the bearing flange and the different coupling splines provided on the shank, and thus the length of the shank. These arrangements therefore make it possible to improve the compactness of the rotary impact hydraulic drill according to the invention.

[0026] According to an embodiment of the invention, the connection surface of each female coupling spline on the shank includes an inclined surface inclined with respect to the extension axis of the shank and extending in the direction of the front abutment surface, advantageously extending in the direction of the front end of the shank in the extension of the curved concave surface.

[0027] According to one embodiment of the invention, the annular bearing flange includes an outer circumferential surface that is generally cylindrical.

[0028] According to one embodiment of the invention, the forward end of each of the female coupling splines on the shank opens onto the outer surface of the annular bearing flange.

[0029] According to one embodiment of the present invention, the front ends of the female coupling splines provided on the shank open onto the outer circumferential surface.

[0030] According to one embodiment of the invention, the outer circumferential surface extends in the direction of the striking piston in the continuation of the annular bearing surface.

[0031] According to one embodiment of the invention, the forward ends of the female coupling splines on the shank open into the annular bearing surface of the annular bearing flange.

[0032] According to one embodiment of the invention, the radial height of the annular bearing flange at the outlet of the front end of each of the female connecting splines on the shank is greater than 50% of the maximum radial height of the annular bearing flange, for example 60% or more or 70% or more.

[0033] According to one embodiment of the invention, each female coupling spline on the shank extends in a longitudinal direction and includes two substantially parallel sides.

[0034] According to one embodiment of the invention, the annular bearing surface extends in the direction of the striking piston at an angle to the striking axis, however, according to a variant of the invention, the annular bearing surface may be perpendicular to the striking axis.

[0035] According to one embodiment of the invention, the front abutment surface is provided on the body.

[0036] According to a further embodiment of the present invention, the rotary impact hydraulic drill comprises an annular abutment ring disposed on the body, the annular abutment ring being disposed about the shank and including the front abutment surface.

[0037] According to one embodiment of the invention, the coupling member comprises a peripheral toothing which is rotatably coupled, for example directly or indirectly, to an output shaft of a drive motor belonging to the rotary drive.

[0038] According to one embodiment of the invention, the coupling member is a coupling pinion.

[0039] According to one embodiment of the invention, the female coupling splines of the shank are evenly distributed around the extension axis.

[0040] According to one embodiment of the present invention, the male interlocking splines of the coupling member are evenly distributed around the extension axis of the shank.

[0041] According to one embodiment of the present invention, the shank comprises a first end provided with an end face facing the striking piston and intended to be struck by the striking piston, and a second end opposite the first end and intended to be coupled to at least one drill burr.

[0042] According to one embodiment of the invention, the coupling portion is formed by the first end of the shank.

[0043] According to one embodiment of the invention, the extension axis of the shank is parallel to the striking axis, for example coinciding with the striking axis.

[0044] According to an embodiment of the present invention, the rotary impact hydraulic drill comprises a main hydraulic supply circuit configured to control the reciprocating sliding of the striking piston along the striking axis.

[0045] According to an embodiment of the invention, the female and male splines on the shank extend to the rear end of the shank. According to a variant of the invention, the rear ends of the female and male splines on the shank are spaced apart from the rear end of the shank.

[0046] According to an embodiment of the invention, the female and male coupling splines on the shank each have an effective length of less than 100 mm.

[0047] According to an embodiment of the invention, the shank has a maximum diameter in front of the annular bearing flange of less than or equal to 61 mm, advantageously less than 46 mm.

[0048] According to an embodiment of the present invention, a bottom surface of each of the female coupling splines on the shank is substantially flat.

[0049] The invention will be better understood with the aid of the following description, with reference to the attached schematic drawing which shows, by way of non-limiting example, one embodiment of this rotary percussion hydraulic drill. [Brief description of the drawings]

[0050] [Figure 1] FIG. 1 is a schematic diagram of a vertical cross section of a rotary impact hydraulic drill according to a first embodiment of the present invention. [Diagram 2] FIG. 2 is a side view of a shank belonging to the rotary impact hydraulic drill of FIG. [Diagram 3] FIG. 3 is a cross-sectional view of the shank of FIG. [Figure 4] FIG. 4 is a partial view in longitudinal section of the shank of FIG. [Diagram 5] FIG. 5 is a partial view in vertical section of a shank of a rotary impact hydraulic drill according to a second embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0051] Figures 1 to 4 show a rotary impact hydraulic drill 2 intended for the penetration of blast holes.

[0052] The rotary impact hydraulic drill 2 comprises a body 3 configured to be slidably mounted on a slider.

[0053] The rotary percussion hydraulic drill 2 further comprises a percussion device 4 including a percussion piston 5 mounted so as to slide alternately in a piston cylinder 6 bounded by a body 3 and extending along a percussion axis A. The percussion piston 5 and the piston cylinder 6 bound a primary control chamber 7, which is annular, and a secondary control chamber 8, which has a cross section larger than that of the primary control chamber 7 and which is antagonistic to the primary control chamber 7.

[0054] The striking device 4 further comprises a control valve 9 arranged to alternately control the reciprocating movement of the striking piston 5 in the piston cylinder 6 following a striking stroke and a return stroke. The control valve 9 is arranged to place the secondary control chamber 8 in such a way that it alternately connects a high-pressure fluid supply duct 11, such as a high-pressure incompressible fluid supply duct, during the striking stroke of the striking piston 5, and a low-pressure fluid return duct 12, such as a low-pressure incompressible fluid return duct, during the return stroke of the striking piston 5. The primary control chamber 7 is advantageously continuously supplied with high-pressure fluid by a supply channel.

[0055] The high pressure fluid supply duct 11 and the low pressure fluid return duct 12 belong to a main hydraulic supply circuit in which the percussion device 4 is provided. The main hydraulic supply circuit may advantageously include a high pressure accumulator connected to the high pressure fluid supply duct 11.

[0056] The rotary impact hydraulic drill 2 also comprises a shank 13 intended to be coupled in a known manner to at least one drill bur (not shown) equipped with a tool. The shank 13 extends longitudinally along an extension axis advantageously coinciding with the striking axis A and comprises a first end 14.1 provided with an end face 15 facing the striking piston 5 and intended to strike the latter during each operating cycle of the rotary impact hydraulic drill 2, and a second end 14.2 opposite the first end 14.1 and intended to be coupled to at least one drill bur.

[0057] The shank 13 comprises a coupling formed, for example, by a first end 14.1 with female coupling splines 16 and male coupling splines 17 extending parallel to the extension axis of the shank 13 and angularly offset from one another relative to the extension axis of the shank 13. The female and male coupling splines 16, 17 are advantageously evenly distributed around the extension axis of the shank 13. Advantageously, each male coupling spline 17 is located between two adjacent female coupling splines 16.

[0058] Each of the female and male coupling splines 16, 17 includes a rear end oriented towards the striking piston 5 and a front end opposite the respective rear end. According to the embodiment shown in Figures 1 to 4, each of the female and male coupling splines 16, 17 extends to the rear end of the shank 13. However, according to one variant of the invention, the rear end of each of the female and male coupling splines 16, 17 may be remote from the rear end of the shank 13.

[0059] The rotary impact hydraulic drill 2 further comprises a rotary drive 18 configured to drive the shank 13 in rotation about a rotation axis substantially coinciding with the impact axis A.

[0060] The rotary drive 18 includes a coupling member 19, such as a tubular coupling pinion, disposed about the shank 13. The coupling member 19 includes male and female coupling splines that are rotatably coupled to the female and male coupling splines 16, 17, respectively, of the shank 13. The male and female coupling splines on the coupling member 19 are evenly distributed about the axis of extension of the shank 13.

[0061] Advantageously, the coupling member 19 comprises a peripheral toothing rotatably coupled to the output shaft of a drive motor 21, such as a hydraulic motor, which is hydraulically supplied by an external hydraulic supply circuit belonging to the rotary drive 18. The rotary drive 18 may, for example, comprise an intermediate pinion 22 coupled to the output shaft of the drive motor 21 on the one hand and to the peripheral toothing of the coupling member 19 on the other hand.

[0062] The rotary impact hydraulic drill 2 further comprises a front abutment surface 23 which is annular and extends around the shank 13. The front abutment surface 23 is arranged on the opposite side of the connecting member 19 from the striking piston 5. The front abutment surface 23 may be provided directly on the body 3 or on an annular abutment ring arranged on the body 3.

[0063] The shank 13 includes an annular bearing flange 24 provided on the outer surface of the shank 13. The annular bearing flange 24 includes an annular bearing surface 25 configured to abut against the front abutment surface 23 so as to limit the forward displacement stroke of the shank 13. Advantageously, the annular bearing surface 25 is inclined with respect to the striking axis A and flares in the direction of the joint of the shank 13.

[0064] 1 to 4, the annular bearing flange 24 further comprises an outer circumferential surface 26 which is substantially cylindrical and extends in the extension of the annular bearing surface 25 towards the rear end of the shank 13. The outer circumferential surface 26 advantageously has an outer diameter greater than or equal to the outer diameter of the connection part.

[0065] Advantageously, each female and male coupling spline 16, 17 extends from the annular bearing flange 24 towards the rear end of the shank 13. According to the embodiment shown in Figures 1 to 4, the front end of each female coupling spline 16 is provided in the annular bearing flange 24 and opens out onto an outer surface of the annular bearing flange 24, for example onto an outer peripheral surface 26 thereof.

[0066] According to the embodiment shown in Figures 1 to 4, each female coupling spline 16 comprises a bottom surface 27 which is substantially planar and extends in the extension direction of said female coupling spline, and a connection surface 28 which connects each bottom surface 27 to the annular bearing flange 24 and extends forward away from the extension axis of the shank 13. According to the embodiment shown in Figures 1 to 4, the connection surface 28 of each female coupling spline 16 is entirely formed by a curved concave surface 28.1 which extends in the extension direction of each female coupling spline 16 and has a radius of curvature R which is smaller than the radial height Hr of each male coupling spline 17 provided on the shank 13. The radius of curvature R of each curved concave surface 28.1 is advantageously smaller than 15 mm, for example smaller than 10 mm.

[0067] Each female coupling spline 16 may, for example, have a rectangular cross-section and therefore may have two longitudinally extending and substantially parallel sides, however, each female coupling spline 16 may also have a generally V-shaped cross-section.

[0068] According to the embodiment shown in Figures 1-4, for each male coupling spline 17, the radial distance DR between the extension axis of the shank 13 and the upper surface 29 of said male coupling spline 17 is substantially constant along said male coupling spline.

[0069] When the cutting edge is jammed in rock, the rotary percussion hydraulic drill 2 is retracted until the annular bearing surface 25 of the annular bearing flange 24 abuts against the front abutment surface 23 .

[0070] Then, to unlock the cutting, the rotary drive 18 is activated to rotary drive the shank 13. The striking device 4 can also be activated simultaneously with the rotary drive 18 to also impact the shank 13 with the striking piston 5.

[0071] Such actuation of the rotary drive device 18 and possibly the impact device 4 induces rotational friction of the annular bearing surface 25 of the annular bearing flange 24 against the front abutment surface 23 of the annular bearing surface 25 and potential axial impact against the front abutment surface 23 of the annular bearing surface 25.

[0072] The presence of the annular bearing flange 24 in front of the female and male coupling splines 16, 17 provided on the shank 13 makes it possible to avoid contact between the front abutment surface 23 and the male coupling splines 17 provided on the shank 13, thus preserving the integrity of the shank 13. Furthermore, the fact that the annular bearing surface 25 is annular ensures a relatively large contact surface between the front abutment surface 23 and the annular bearing flange 24, and therefore a better distribution of the impact forces exerted by the shank 13 against the front abutment surface 23.

[0073] Therefore, the specific configuration of the rotary impact hydraulic drill 2 of the present invention makes it possible to give the shank 13 a significantly increased service life and significantly reduce the period of immobility of the rotary impact hydraulic drill 2 for replacing the shank 13, thereby reducing the risk of damage to the rotary impact hydraulic drill 2 by wear particles from the shank 13.

[0074] Furthermore, when the male coupling spline 17 provided on the shank 13 extends directly from the annular bearing flange 24, the axial length of the shank 13 is not affected by the presence of the annular bearing flange 24, making it possible to obtain a compact rotary impact hydraulic drill 2.

[0075] Figure 5 shows a shank 13 of a rotary impact hydraulic drill 2 according to a second embodiment of the present invention. The shank 13 differs substantially from the first embodiment shown in Figures 1 to 4 in that the front end of each female connecting spline 16 opens into an annular bearing surface 25 of an annular bearing flange 24. According to such an embodiment of the present invention, the radial height of the annular bearing flange 24 at the outlet of the front end of each female connecting spline 16 is greater than 50% of the maximum radial height of the annular bearing flange 24, for example 60% or more or 70% or more.

[0076] Needless to say, the invention is not limited to the sole embodiment of this rotary percussion hydraulic drill described above by way of example, but on the contrary covers all its variants.

Claims

1. Body (3) and a shank (13) intended to be coupled to at least one drill burr equipped with a tool; a striking piston (5) slidably mounted inside the body (3) along a striking axis (A) and configured to strike the shank (13); a rotational drive (18) configured to rotationally drive the shank (13) about an axis of rotation substantially coincident with the striking axis; a front abutment surface (23) fixed relative to the body; The shank (13) includes a coupling portion having a female coupling spline (16) and a male coupling spline (17) that are angularly offset from one another relative to an elongated axis of the shank (13); The rotary drive (19) includes a coupling member (19) disposed around the shank (13); the coupling member (19) includes male and female coupling splines rotatably coupled to the female and male coupling splines (16, 17) of the shank (13), The front abutment surface (23) is annular and extends around the shank (13); The shank (13) is configured to abut against the front abutment surface (23) to limit a forward displacement stroke of the shank (13). A rotary impact hydraulic drill (2), the shank (13) includes an annular bearing flange (24) provided on an outer surface of the shank (13) and having an annular bearing surface (25) configured to abut against the front abutment surface (23); The female and male coupling splines (16, 17) on the shank (13) each extend from the annular bearing flange (24) towards the striking piston (5); Each of the female coupling splines (16) on the shank (13) includes a bottom surface (27) and a connecting surface (28) connecting each of the bottom surfaces (27) to the annular bearing flange (24) and extending forwardly away from the axis of extension of the shank (13); the connecting surface (28) of each of the female coupling splines (16) on the shank (13) is at least partially formed by a curved concave surface (28.1) extending substantially in the extension direction of each of the female coupling splines and having a radius of curvature (R) smaller than the radial height (Hr) of each of the male coupling splines on the shank (13); A rotary impact hydraulic drill (2).

2. 2. The rotary impact hydraulic drill (2) of claim 1, wherein the annular bearing flange (24) has a maximum outer diameter equal to or greater than an outer diameter of the coupling portion.

3. 3. The rotary percussion hydraulic drill (2) according to claim 1 or 2, wherein a front end of each female coupling spline (16) provided on the shank (13) is provided on the annular bearing flange (24).

4. 4. The rotary impact hydraulic drill (2) of claim 1, wherein each of the male coupling splines (17) on the shank (13) includes an upper surface (29) extending from the annular bearing flange (24).

5. 5. The rotary impact hydraulic drill (2) according to claim 1, wherein the connecting surface (28) of each of the female coupling splines (16) provided on the shank (13) is entirely formed by each of the curved concave surfaces (28.1).

6. 6. The rotary impact hydraulic drill (2) according to claim 1, wherein each of the female and male coupling splines (16, 17) provided on the shank (13) extends to a rear end of the shank (13).

7. 7. The rotary percussion hydraulic drill (2) according to any one of claims 1 to 6, wherein the radius of curvature (R) of each of the curved concave surfaces (28.1) is less than 15 mm.

8. 8. The rotary percussion hydraulic drill (2) of any one of claims 1 to 7, wherein the annular bearing flange (24) includes an outer circumferential surface (26) that is generally cylindrical.

9. 9. The rotary impact hydraulic drill (2) according to claim 8, wherein a front end of each of the female coupling splines (16) provided on the shank (13) opens into the outer circumferential surface (26).

10. 9. The rotary impact hydraulic drill (2) according to any one of claims 1 to 8, wherein a front end of each of the female connecting splines (16) provided on the shank (13) opens into the annular bearing surface (25) of the annular bearing flange (24).

11. 11. The rotary impact hydraulic drill (2) according to claim 10, wherein the radial height of the annular bearing flange (24) at the outlet of the front end of each of the female connecting splines (16) provided on the shank (13) is greater than 50% of the maximum radial height of the annular bearing flange (24).

12. 12. The rotary percussion hydraulic drill (2) according to any one of the preceding claims, wherein the annular bearing surface (25) extends in the direction of the striking piston (5) at an angle to the striking axis.

13. 13. The rotary impact hydraulic drill (2) according to any one of claims 1 to 12, comprising an annular abutment ring disposed on the body (3), the annular abutment ring being disposed around the shank (13) and including the front abutment surface (23).

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