Patent Application
20230339087
This application claims priority under 35 U.S.C. ยง 119 to the following French Patent Application No. FR 22/03645, filed on Apr. 20, 2022, the entire contents of which are incorporated herein by reference thereto.
The present disclosure relates to a percussion apparatus, and more particularly to a percussion hydraulic apparatus, provided with a pressure regulating device.
A percussion apparatus includes in a known manner:
Such a pressure regulating device makes it possible to ensure, at each operating cycle of the percussion apparatus, an impact of the striking piston on the tool with a predetermined impact speed, that is to say a predetermined impact energy.
Such a pressure regulating device may for example comprise:
In order to be able to adjust the performance of the percussion apparatus, it is known to set the prestress exerted by the biasing element on the pressure regulating slide using shim washers introduced into the regulating cylinder. The addition or removal of such shim washers makes it possible to modify the predetermined value at which the operating pressure is regulated, and therefore to modify the impact speed of the striking piston.
However, the addition or removal of shim washer(s) in order to carry out the aforementioned prestress setting requires the removal of a blanking plug to access the regulating cylinder and therefore the opening of a hydraulic circuit leaving escaping a large quantity of hydraulic oil, which, depending on the environment in which this operation is carried out, may cause pollution if this hydraulic oil is not contained.
The present disclosure aims to remedy this drawback.
The technical problem at the basis of the present disclosure therefore consists in providing a percussion apparatus equipped with a pressure regulating device provided with a biasing element whose prestress may be easily set by a user without risk of pollution of the environment of the percussion apparatus.
To this end, the present disclosure concerns a percussion apparatus, including:
the setting member and the actuating member being configured such that a rotation of the setting member about the axis of rotation and in a first direction of rotation causes a displacement of the actuating member towards the pressure regulating slide so as to increase the prestress applied by the biasing element on the pressure regulating slide and such that a rotation of the setting member about the axis of rotation and in a second direction of rotation, opposite to the first direction of rotation, causes a displacement of the actuating member away from the pressure regulating slide so as to reduce the prestress applied by the biasing element on the pressure regulating slide,
and in that the pressure regulating device includes an indexing mechanism configured to define, for the setting member, a plurality of angular indexing positions in each of which the setting member occupies, relative to the actuating member, a respective angular position which is stable.
Such a configuration of the pressure regulating device of the percussion apparatus according to the present disclosure allows a user to easily set the prestress exerted by the biasing element by rotating the setting member from the outside of the percussion apparatus, that is to say without opening a hydraulic circuit and therefore without risk of pollution of the environment of the percussion apparatus.
The percussion apparatus may also have one or more of the following characteristics, taken alone or in combination.
According to one embodiment of the present disclosure, the connecting channel is connected to the control distributor, and the control distributor is configured to connect the connecting channel to the second control chamber during the return stroke of the striking piston.
According to one embodiment of the present disclosure, the biasing element includes a first end portion configured to cooperate with, and for example to bear against, the actuating member, and a second end portion configured to cooperate with, and for example to bear against, the pressure regulating slide.
According to one embodiment of the present disclosure, the actuating member is slidably mounted in the direction of displacement.
According to one embodiment of the present disclosure, the actuating member includes a seat, preferably annular, against which the first end portion of the biasing element bears.
According to one embodiment of the present disclosure, the biasing element is a compression spring, the first end portion of which bears against the actuating member and the second end portion of which bears against the pressure regulating slide.
According to one embodiment of the present disclosure, the setting member includes an annular abutment surface against which the actuating member is configured to come into abutment, the annular abutment surface being configured to limit the displacement stroke of the actuating member as opposed to the pressure regulating slide.
According to one embodiment of the present disclosure, the number of angular indexing positions is between two and eight, advantageously between four and eight, and is for example equal to six.
According to one embodiment of the present disclosure, the passage opening includes a first end opening into the regulating cylinder and a second end opening out of the percussion apparatus.
According to one embodiment of the present disclosure, the setting part extends at least partly into the passage opening.
According to one embodiment of the present disclosure, the blanking plug includes a blanking part provided with an external surface into which the second end of the passage opening opens. Advantageously, the setting part is flush with or is set back from the external surface of the blanking part. However, according to one variant embodiment of the present disclosure, the setting part could protrude from said external surface.
According to one embodiment of the present disclosure, the passage opening extends coaxially with the axis of rotation.
According to one embodiment of the present disclosure, the blanking plug is fastened to the body, for example by screwing, and is configured to be immobile relative to the body.
According to one embodiment of the present disclosure, the indexing mechanism includes several indexing recesses provided on one of the blanking plug and the setting member and distributed about the axis of rotation, and at least one indexing projection provided on the other of the blanking plug and the setting member and configured to cooperate with one of the indexing recesses when the setting member occupies a respective angular indexing position.
According to one embodiment of the present disclosure, the indexing mechanism includes several indexing projections distributed about the axis of rotation.
According to one embodiment of the present disclosure, the at least one indexing projection is formed by an indexing ball mounted within a receiving cavity which is provided on the blanking plug or the setting member and which is internally delimited by a spherical surface portion.
According to one embodiment of the present disclosure, the setting member is displaceable in translation relative to the blanking plug in a direction substantially parallel to the direction of displacement, the biasing element being configured to maintain the setting member in contact with the blanking plug. Thus, the force exerted by the biasing element on the setting member and the cam effect between the blanking plug and the setting member prevents any misadjustment due to the vibrations generated by the percussion apparatus.
According to one embodiment of the present disclosure, the blanking plug forms a cam and the setting member forms a cam follower.
According to one embodiment of the present disclosure, the setting member includes a bearing part, such as a bearing flange, which is located axially between the setting part and the drive part, and which is configured to bear against the blanking plug.
According to one embodiment of the present disclosure, the blanking plug includes an internal guide surface which is generally cylindrical, and which is configured to guide the setting member in rotation and in translation.
According to one embodiment of the present disclosure, the bearing part includes the annular abutment surface.
According to one embodiment of the present disclosure, the blanking plug includes a fastening part which is tubular, and which is fastened in the regulating cylinder, the actuating member being mounted displaceable, and for example slidably mounted, within the fastening part.
According to one embodiment of the present disclosure, the actuating member includes first splines extending in the direction of displacement, and the blanking plug includes second splines extending in the direction of displacement and configured to cooperate with the first splines provided on the actuating member, the first and second splines being configured to guide the actuating member in translation in the direction of displacement.
According to one embodiment of the present disclosure, the second splines are provided on an internal surface of the fastening part.
According to one embodiment of the present disclosure, the blanking plug includes a plug body and an internal, for example annular, insert which is disposed in the plug body and which is fixed relative to the plug body, the internal insert being interposed between the plug body and the setting member, and the indexing recesses or the at least one indexing projection being provided on the internal insert.
According to one embodiment of the present disclosure, the internal insert is interposed between the plug body and the bearing part.
According to one embodiment of the present disclosure, the drive part includes a threaded drive rod extending substantially parallel to the direction of displacement, and the actuating member includes a tapped axial bore configured to cooperate with the threaded drive rod.
According to one embodiment of the present disclosure, the pressure regulating slide, the setting member and the actuating member are disposed substantially coaxially.
According to one embodiment of the present disclosure, the pressure regulating slide includes an annular groove which is permanently fluidly connected to the connecting channel, the annular groove including an annular edge configured to define the connecting passage at least partially.
According to one embodiment of the present disclosure, the pressure regulating device includes a first regulating chamber which is delimited by the pressure regulating slide and the regulating cylinder and which is permanently fluidly connected to the high-pressure fluid supply circuit, and a second regulating chamber which is delimited by the pressure regulating slide and the regulating cylinder and which is permanently fluidly connected to the low-pressure return circuit, the connecting passage being configured to fluidly connect the connecting channel to the second regulating chamber.
According to one embodiment of the present disclosure, the biasing element and the actuating member are disposed in the second regulating chamber.
According to one embodiment of the present disclosure, the second regulating chamber is antagonist to the first regulating chamber.
According to one embodiment of the present disclosure, a first face of the pressure regulating slide is located in the first regulating chamber and a second face of the pressure regulating slide, opposite to the first face, is located in the second regulating chamber.
According to one embodiment of the present disclosure, the prestress setting device includes setting marks provided on a fixed reading area, for example provided on the body or the blanking plug, each setting mark corresponding to a respective angular indexing position (and therefore to a respective value of the prestress applied by the biasing element on the pressure regulating slide), and a reading mark associated with the setting marks and provided on the setting part.
According to one embodiment of the present disclosure, the pressure regulating device includes an abutment, for example annular, element fastened to the setting member, for example to the drive part, and configured to limit the displacement stroke of the actuating member towards the pressure regulating slide.
According to one embodiment of the present disclosure, the blanking plug includes an annular internal groove extending around the setting part, and a seal disposed in the annular internal groove and configured to cooperate with the setting part. The seal may for example be provided with an annular sealing lip configured to cooperate with the setting part.
According to one embodiment of the present disclosure, the blanking plug and the actuating member define an annular housing in which the first end portion of the biasing element is received.
According to one embodiment of the present disclosure, the blanking plug includes an annular external groove provided on the fastening part and extending around the fastening part, and an annular seal disposed in the annular external groove and configured to cooperate with the body of the percussion apparatus. The annular seal may for example be an O-ring.
Anyway, the present disclosure will be well understood, using the following description with reference to the appended schematic drawings representing, as non-limiting examples, several embodiments of this percussion apparatus.
The percussion apparatus 2 includes a body 3 delimiting a piston cylinder 4, and a striking piston 5 which is stepped, and which is slidably mounted in a reciprocating manner inside the piston cylinder 4. During each operating cycle of the percussion apparatus 2, the striking piston 5 is configured to hit the upper end of a tool 6 slidably mounted inside a bore 7 provided in the body 3 coaxially with the piston cylinder 4.
The striking piston 5 and the piston cylinder 4 delimit a first control chamber 8 which is annular, and a second control chamber 9 which is antagonist to the first control chamber 8 and which has a larger cross section than that of the first control chamber 8. The second control chamber 9 may for example be disposed above the striking piston 5.
The percussion apparatus 2 further includes a control distributor 11 arranged to control a reciprocating movement of the striking piston 5 inside the piston cylinder 4 in a reciprocating manner along a striking stroke and a return stroke. The control distributor 11 is configured to fluidly connect the second control chamber 9 in a reciprocating manner with a high-pressure fluid supply circuit 12 during the striking stroke of the striking piston 5, and with a low-pressure return circuit 13 during the return stroke of the striking piston 5.
The first control chamber 8 is permanently connected to the high-pressure fluid supply circuit 12 by a supply channel 14, so that each position of the control distributor 11 causes the striking stroke of the striking piston 5, then the return stroke of the striking piston 5. The supply channel 14 may advantageously be connected to a hydraulic accumulator 15.
The percussion apparatus 2 further includes a pressure regulating device 16 configured to regulate an operating pressure of the percussion apparatus 2 to a predetermined value.
As shown more particularly in
The pressure regulating slide 18 and the regulating cylinder 17 delimit a first regulating chamber 19 which is permanently fluidly connected to the high-pressure fluid supply circuit 12 through a channel 21 fluidly connected to the first control chamber 8, and a second regulating chamber 22 which is antagonist to the first regulating chamber 19 and which is permanently fluidly connected to the low-pressure return circuit 13. Advantageously, a first face of the pressure regulating slide 18 is located in the first regulating chamber 19 and a second face of the pressure regulating slide 18, opposite to the first face, is located in the second regulating chamber 22.
The pressure regulating device 16 also includes a connecting channel 23 including a first end which is fluidly connected to the control distributor 11, and a second end which opens into the regulating cylinder 17. The control distributor 11 is more particularly configured to connect the connecting channel 23 to the second control chamber 9 during the return stroke of the striking piston 5.
The pressure regulating slide 18 and the regulating cylinder 17 are also configured to delimit a connecting passage 24 having a passage section which varies according to the regulating position occupied by the pressure regulating slide 18. The connecting passage 24 is configured to fluidly connect the connecting channel 23 to the second regulating chamber 22, and therefore to the low-pressure return circuit 13. Advantageously, the pressure regulating slide 18 includes, on its external surface, an annular groove 25 permanently fluidly connected to the connecting channel 23 and provided with an annular edge 25.1 configured to define the connecting passage 24 at least partially.
The pressure regulating device 16 further includes a biasing element 26, such as a compression spring, disposed in the second regulating chamber 22 and configured to exert a prestress on the pressure regulating slide 18 and to bias the pressure regulating slide 18 to a regulating position in which the passage section of the connecting passage 24 is minimal and for example zero or substantially zero. Thus, when the percussion apparatus 2 is not supplied with high-pressure fluid, the biasing element 26 exerts a force on the pressure regulating slide 18 intended to close the connecting passage 24. When the percussion apparatus 2 is supplied with high-pressure fluid, the first regulating chamber 19 is supplied with high-pressure fluid through the channel 21 and exerts, on the pressure regulating slide 18, a force opposite to that exerted by the biasing element 26. As soon as this force exceeds that of the prestress exerted by the biasing element 26, the pressure regulating slide 18 translates towards the biasing element 26, which increases the passage section of the connecting passage 24.
The pressure regulating device 16 further includes a prestress setting device 27 configured to set the prestress exerted by the biasing element 26 on the pressure regulating slide 18.
As shown more particularly in
The blanking plug 28 may for example include an annular external groove provided on the fastening part 28.1 and extending around the fastening part 28.1, and an annular seal 290 disposed in the annular external groove and configured to cooperate with the body 3 of the percussion apparatus 2. The annular seal 290 may for example be an O-ring.
The prestress setting device 27 further includes an actuating member 29 configured to cooperate with the biasing element 26. The actuating member 29 is disposed in the second regulating chamber 22 and is displaceable in a direction of displacement parallel to the direction of translation D. Advantageously, the actuating member 29 forms a pusher configured to exert a pushing force on the biasing element 26.
Advantageously, the actuating member 29 is connected to the blanking plug 28 by a guideway connection. In particular, the actuating member 29 is slidably mounted within the fastening part 28.1 of the blanking plug 28 and in the direction of displacement. To this end, the actuating member 29 includes, on its external surface, first splines 31 extending in the direction of displacement, and the fastening part 28.1 includes, on its internal surface, second splines 32 extending in the direction of displacement and configured to cooperate with the first splines 31 provided on the actuating member 29. The first and second splines 31, 32 are configured to guide the actuating member 29 in translation in the direction of displacement.
As shown in
Advantageously, the blanking plug 28 and the actuating member 29 define an annular housing in which the first end portion of the biasing element 26 is received.
According to the embodiment represented in
The setting member 35 includes a setting part 36, which may for example be globally cylindrical, configured to be accessible from the outside of the percussion apparatus 2 and to be driven in rotation by a user. To this end, the blanking part 28.2 includes a passage opening 37 configured to make the setting part 36 accessible from the outside of the percussion apparatus 2. Advantageously, the passage opening 37 extends coaxially with the axis of rotation A and includes a first end opening into the regulating cylinder 17 and a second end opening into an external surface of the blanking part 28.2. According to the embodiment represented in
The setting member 35 further includes a drive part 38 disposed in the second regulating chamber 22, and mechanically connected to the actuating member 29. The drive part 38 is advantageously connected to the actuating member 29 by a helical connection. According to the embodiment represented in
The setting member 35 and the actuating member 29 are more particularly configured such that a rotation of the setting member 35 about the axis of rotation A and in a first direction of rotation causes a displacement of the actuating member 29 towards the pressure regulating slide 18 (and therefore a compression of the biasing element 26) so as to increase the prestress applied by the biasing element 26 on the pressure regulating slide 18, and in such a way that a rotation of the setting member 35 about the axis of rotation A and in a second direction of rotation, opposite to the first direction of rotation, causes a displacement of the setting member 29 away from the pressure regulating slide 18 (and therefore a relaxation of the biasing element 26) so as to reduce the prestress applied by the biasing element 26 on the pressure regulating slide 18.
According to the embodiment represented in
The pressure regulating device 16 may also include (according to a second embodiment of the present disclosure represented in
According to the embodiment represented in
The pressure regulating device 16 also includes an indexing mechanism 49 configured to define, for the setting member 35, a plurality of angular indexing positions in each of which the setting member 35 occupies, relative to the actuating member 29, a respective angular position which is stable. The number of angular indexing positions may be between two and eight, advantageously between four and eight, and is for example equal to six.
According to the embodiment represented in
Advantageously, the prestress setting device 27 may also include:
To set the prestress exerted by the biasing element 26 on the pressure regulating slide 18, a user rotates the setting member 35 with the aid of a suitable key inserted for example in a hexagon imprint provided on the setting part 36, until positioning the reading mark opposite the setting mark corresponding to the desired prestress value. Such a rotation of the setting member 35 causes a translation of the actuating member 29 relative to the blanking plug 28 (towards the pressure regulating slide 18 or the blanking plug 18 according to the direction of rotation), because the actuating member 29 is connected to the setting member 35 by a helical connection and is connected to the blanking plug 28 by a guideway connection. Such a translation of the actuating member 29 allows the setting of the prestress exerted by the biasing element 26 on the pressure regulating slide 18.
Advantageously, each indexing recess 51 and/or each indexing projection 52 include inclined or rounded surfaces so as to limit the torque required to overcome the resistance induced by the cam connection between the blanking plug 28 and the setting member 35.
Of course, the present disclosure is in no way limited to the embodiments described and illustrated which have been given only by way of examples. Modifications remain possible, in particular from the point of view of the constitution of the various elements or by substitution of technical equivalents, without departing from the field of protection of the present disclosure.
| Number | Date | Country | Kind |
|---|---|---|---|
| 22/03645 | Apr 2022 | FR | national |
