EP3307960B1 - Hydraulic percussion device - Google Patents

Description

TECHNICAL AREA

The present invention relates to the field of public works machinery. It relates to a percussion hydraulic apparatus type "breaker" or the like.

PRIOR ART

As described on Figures 1 and 2 of the state of the art, hydraulic percussion devices 100 called "breakers" generally consist of a body containing a striking cell 140 and a casing 150 which allows on the one hand, to protect the cell striking 140 abrasive rocks and secondly, mechanically maintain the assembly to hang on one end of an arm 12 of a carrier vehicle 11, for example a hydraulic shovel. The striking cell 140 comprises a striking piston 180 movable in a chamber so as to strike a tool 19 held in alignment with a lower end of the striking piston 180.

The movements of the striking piston 180 are controlled by two annular chambers 370, 380 antagonists fed alternately with fluid under pressure. The striking cell 140 also comprises a compression chamber 220, containing a compressible gas, disposed above the striking piston 180. When the apparatus 100 is actuated, a first phase consists in moving the striking piston 180 in the chamber compression 220 by applying a pressure in the lower annular chamber 380, thereby compressing the gas in the compression chamber 220. A second phase is to cancel the effect of the pressure in the lower annular chamber 380, feeding the same pressure the upper annular chamber 370. The force then applied to the striking piston 180 depends on the surface difference between the annular chambers 370, 380 and this surface difference is small. In a third phase, the compressible gas relaxes and violently moves the striking piston 180 downwardly impacting the tool 19 with sufficient force to break a rock.

Thus, the pressure of the gas in the compression chamber 220 is very important. To contain this pressure, an upper end of the striking cell 140 is closed by a cover 240 fixed in the amounts of the striking cell 140 by a series of screws 310. This series of screws 310 arranged annularly is necessary to maintain a seal of the compression chamber 220.

However, this solution is particularly complex to implement because of these high pressures on the cover 240. Thus, the thickness of the amounts of the striking cell 140 must be oversized to accommodate the series of screws 310. The screws 310 must be selected with great length and quality. The number of screws 310 required negatively impacts the weight of the hydraulic percussion apparatus 100 as well as the mounting time of the apparatus.

In addition, the arm 12 of the carrier machine 11 is movable so as to move the tool 19 against a surface S to destroy. To do this, the striking cell 140 is mounted in a casing 150 which is itself fixed on the arm 12 by a fixing plate 160 forming a U. The fixing plate 160 may be arranged on the side of the casing 150 or on a cover 200 of the housing 150 as illustrated on the Figure 2 . The force of the arm 12 of the carrier machine 11 is transmitted to the tool 19 via means 260 bearing on the tool 19 fixed in the striking cell 140.

When the hydraulic percussion apparatus 100 strikes a surface S to be destroyed, it transmits a compression wave F on this surface S in the direction of movement of the tool 19. This wave F can induce a reflected shock wave R in the direction opposite to the wave F generated by the striking piston 180. This reflected shock wave R is transmitted to the entire striking cell 140 by the support means 260 of the tool 19. To avoid transmitting this wave of resulting shock R on the arm 12 of the carrier 11, the striking cell 140 is mounted in the casing 150 between two suspensions upper 280 and lower 281. The movements of the striking cell 140 relative to the housing 150 are guided by 290 guide means disposed along the housing 150.

This solution also has a disadvantage related to the upper 280 and lower 281 suspensions. These elastic assemblies must withstand the heat, oils and greases, the thrust forces of the carrier vehicle 11 and the forces induced by the reflected wave R. These are wear parts with high costs and whose service lives remain low. In addition, very often, it is necessary to provide a wedging to obtain a predetermined pre-compression of the upper suspension 280 to maintain the closure plate 200 closing the casing 150.

The document US5,285,858 discloses a striking cell mounted on an arm of a carrier vehicle via a damper. The damper includes an upper plate secured with the arm of the machine, a lower plate and a rubber member disposed between the two plates to absorb shocks from the striking cell. To do this, the impacts of the impact cell are transmitted to the lower plate by means of a stop element displaceable in translation in a groove of the lower plate and a groove formed on the upper part of the cell. hit. The stop element makes it possible to put a distance between the impact cell and the lower plate and thus transmit only the most important shocks to the carrier vehicle.

However, the stop member does not absorb shock because absorption is achieved by the rubber member.

The invention aims to find a solution for installing a striking cell 140 in a housing 150 without having to use a complex and expensive suspension.

SUMMARY OF THE INVENTION

The present invention aims to solve this technical problem using a suspension made by a movable closing piston in a chamber containing a compressible fluid.

• un carter comportant une plaque de fermeture,
• une cellule de frappe montée dans le carter comportant un piston de frappe mobile en translation, et
• un amortisseur reliant la cellule de frappe et la plaque de fermeture de manière à transmettre les efforts de déplacement appliqués sur le carter à la cellule de frappe, l'amortisseur comportant :
• un corps solidaire de la cellule de frappe en regard de la plaque de fermeture,
• une chambre ménagée à l'intérieur du corps, et
• un piston de fermeture mobile dans la chambre apte à venir en appui sur la plaque de fermeture pour obturer la chambre,
• la chambre étant destinée à contenir un fluide compressible apte à amortir les déplacements de la cellule de frappe par rapport au carter.

For this purpose, the invention relates to a hydraulic percussion apparatus intended to be installed on a carrier vehicle, the apparatus comprising:

• a housing having a closure plate,
• a striking cell mounted in the casing comprising a movable plunger in translation, and
• a shock absorber connecting the striking cell and the closure plate so as to transmit the displacement forces applied on the casing to the impact cell, the damper comprising:
• a body secured to the striking cell opposite the closing plate,
• a chamber formed inside the body, and
• a closing piston movable in the chamber adapted to bear on the closure plate to close the chamber,
• the chamber being intended to contain a compressible fluid capable of damping the movements of the striking cell with respect to the housing.

The invention thus makes it possible to reproduce more simply the role of the cover and suspensions of the prior art by a movable closing piston in a chamber containing a compressible fluid. The impact cell can thus be lightened compared to the devices of the prior art by decreasing the thickness of the amounts of the impact cell and removing the screws and the cover. The damping of the movements of the striking cell relative to the housing and the housing relative to the impact cell is also improved which allows to remove the lower suspension.

The apparatus according to the invention can be integrated in various configurations.

According to a first embodiment, at least a portion of the striking piston is intended to penetrate into the chamber so that, when the chamber contains a compressible fluid, the displacement of the striking piston inside the chamber is suitable for compressing the compressible fluid and decompressing the compressible fluid is able to move the striking piston. Thus, the damper also serves as an actuator for the striking piston. This embodiment makes it possible to eliminate the closure lid of the impact cell and thus to simplify and lighten the apparatus.

According to a second embodiment, the striking cell is connected to a pressure accumulator comprising a hydraulic circuit and a pneumatic circuit separated by a deformable membrane, the chamber is in pneumatic communication with the pneumatic circuit of the pressure accumulator so that that the pressure contained in the hydraulic circuit is transmitted to the chamber through this membrane. In this case, the damper also acts as a pressure accumulator, to withstand the water hammers or the strong pressure variations generated by the impact cell. This embodiment also makes it possible to remove the closure lid of the impact cell and thus to simplify and lighten the apparatus.

According to a third embodiment, the striking cell being closed by a cover, the body comprising the chamber is mounted on said cover.

In this embodiment, the damper is hydraulically independent of the displacement members of the striking piston. This embodiment makes it possible to limit the pressures experienced by the cover of the actuating chamber.

• un corps, destiné à assurer l'étanchéité de la chambre, et,
• une tête, destinée à assurer le maintien du piston de fermeture contre la plaque de fermeture. Avantageusement, le corps du piston de fermeture comporte une rainure contenant un joint d'étanchéité adapté au diamètre de la chambre et à une pression attendue dans la chambre. Ce mode de réalisation permet de garantir l'étanchéité de la chambre de l'amortisseur.

According to one embodiment, the closing piston comprises:

• a body, intended to seal the chamber, and,
• a head, intended to ensure the maintenance of the closing piston against the closure plate. Advantageously, the body of the closing piston comprises a groove containing a seal adapted to the diameter of the chamber and to an expected pressure in the chamber. This embodiment makes it possible to guarantee the tightness of the damper chamber.

Advantageously, in practice the chamber is intended to contain nitrogen in gaseous form. This embodiment makes it possible to respond effectively to the compression and expansion stresses of the compressible fluid.

According to one embodiment, the apparatus comprises a fastening element of the housing integral with the closure plate, the fixing element being intended to fix the housing on a carrier vehicle. Alternatively, the fixing element is positioned on the housing in a zone remote from the closure plate.

SUMMARY DESCRIPTION OF THE FIGURES

• Figure 1, état de la technique : une représentation schématique en perspectives d'un engin porteur équipé d'un appareil hydraulique à percussions;
• Figure 2, état de la technique : une représentation schématique en coupe de l'appareil hydraulique à percussions de la Figure 1 ;
• Figure 3 : une représentation schématique en coupe d'un appareil hydraulique à percussions selon un premier mode de réalisation de l'invention ;
• Figure 4 : une représentation schématique en coupe d'un appareil hydraulique à percussions selon un deuxième mode de réalisation de l'invention ;
• Figure 5 : une représentation schématique en perspective de l'appareil hydraulique à percussions de la Figure 4 ;
• Figure 6 : une représentation schématique en perspective d'une cellule de frappe selon le mode de réalisation de la Figure 4 ; et
• Figure 7 : une représentation schématique en coupe d'un appareil hydraulique à percussions selon un troisième mode de réalisation de l'invention.

The manner of carrying out the invention as well as the advantages which result therefrom, will emerge clearly from the following embodiment, given by way of indication but not limitation, in support of the appended figures in which the Figures 1 to 6 represent:

• Figure 1 state of the art: a schematic representation in perspective of a carrier equipped with a hydraulic percussion apparatus;
• Figure 2 , state of the art: a schematic representation in section of the hydraulic percussion apparatus of the Figure 1 ;
• Figure 3 : a schematic representation in section of a hydraulic percussion apparatus according to a first embodiment of the invention;
• Figure 4 : a schematic representation in section of a hydraulic percussion apparatus according to a second embodiment of the invention;
• Figure 5 : a schematic representation in perspective of the hydraulic percussion apparatus of the Figure 4 ;
• Figure 6 : a schematic representation in perspective of a striking cell according to the embodiment of the Figure 4 ; and
• Figure 7 : a schematic representation in section of a hydraulic percussion apparatus according to a third embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

In the description, the hydraulic percussion apparatus 10a, 10b, 10c is described assuming that it is positioned in its most common configuration, namely vertically, that is with the tool 19 vertically oriented at contact of a surface to be destroyed as illustrated on the Figure 1 .

The Figure 3 illustrates a hydraulic hydraulic percussion apparatus 10a having a casing 15 supporting a striking cell 14. The striking cell 14 has a substantially cylindrical or parallelepipedal shape closed by a cover 32. The striking cell 14 is mounted inside the casing 15 between a damper 28, guide means 29 and a stop 25. U 16 forming a mounting plate is arranged on the side of the housing 15 for fixing the case 15 on the arm 12 of a carrier 11. Alternatively , as described in Figures 4 to 7 the fixing plate 16 can be arranged on the upper part of the housing 15.

The housing 15 comprises a closure plate 20a fixed to the uprights surrounding the impact cell 14. The damper 28 is positioned between this closure plate 20a and the cover 32 of the impact cell 14. This damper 28 comprises a body 27 secured to the striking cell 14 facing the closure plate 20a. By integral is meant that the body 27 is attached directly or indirectly to the impact cell 14. A chamber 22 is formed inside the body 27 and a closing piston 30 is mounted to move in translation in the chamber 22. The body 27 and the chamber 22 are preferably cylindrical. The closing piston 30 is dimensioned to seal the chamber 22. For example, as shown in FIG. Figure 3 , the closing piston 30 may comprise a body 44 and a head 45 cylindrical. The diameter of the body 44 is adapted to the diameter of the chamber 22 so as to guaranteeing the sealing of the chamber 22. Preferably, the body 44 comprises a groove containing a seal 43 adapted to the diameter of the chamber 22.

The chamber 22 is intended to contain a compressible fluid, for example nitrogen in gaseous form. The head 45 of the closing piston 30 is pressed against the closure plate 20a when the chamber 22 is under pressure. The compressible fluid is intended to damp the movements of the striking cell 14 with respect to the housing 15, for example when a reflected shock wave is transmitted to the striking cell 14 by the tool 19. The compressible fluid can also dampen the displacement of the housing 15 relative to the impact cell 14 for example when a sudden movement of the tool 19 is controlled by the arm 12 of a carrier 11.

In the first embodiment of the Figure 3 , the striking piston 18 contained in the striking cell 14 is movable in an actuating chamber distinct from the chamber 22 of the damper 28. In the second embodiment of FIG. Figures 4 to 6 , the actuating chamber of the striking piston 18 and the chamber 22 of the damper 28 are formed by a single bore passing through the striking cell 14. The body 23 of the striking cell 14 coincides with the body 27 of the damper 28. from bottom to top, the body 23 of the impactor cell 14 contains a part of the tool 19, the striking piston 18 and a part of the closing piston 30. These two elements are movable in the chamber 22 and extend longitudinally along the same axis X.

The tool 19 has an upper end intended to receive shocks from the striking piston 18. The shock wave then propagates along the body of the tool 19 to a lower end intended to come into contact with the surface. S to destroy. The body of the tool 19 is preferably cylindrical with a flat in which two keys 17 are arranged. The keys 17 are connected to the striking cell 14 so as to limit the rotational and translational movements of the tool 19. The keys 17 also make it possible to hold the tool 19 in the striking cell 14 during the movements of the percussion hydraulic apparatus 10b and when the tool 19 is not in contact with a surface S to be destroyed. The arm 12 of a carrier machine 11 can also press the tool 19. To do this, the arm 12 moves the housing 15 thus causing a displacement of the striking cell 14. Means 26 of support on the tool 19 are also fixed in the body 23 of the striking cell 14 at a bevelled surface of the tool 19 so as to transmit the movements of the striking cell 14 to the tool 19.

The striking piston 18 is movable in the body 23 of the striking cell 14 by means of two annular chambers 37, 38 antagonists fed alternately with fluid under pressure. The two chambers 37, 38 are controlled by a hydraulic control device 41. The striking cell 14 also comprises a compression chamber, containing a compressible gas, disposed above the striking piston 18. The compression chamber is merged with the chamber 22 of the damper 18. The same compressible gas, for example nitrogen, is used to perform the function of the compression chamber and the function of the damper 18.

When the hydraulic percussion apparatus 10b is actuated, a first phase is to move the striking piston 18 in the chamber 22 by injecting a pressure into the lower annular chamber 38, thereby compressing the gas in the chamber 22. A second phase consists in canceling the effect of the pressure in the lower annular chamber 38, feeding at the same pressure the upper annular chamber 37, virtually no force is then applied to the striking piston 18 by the annular chambers 37, 38 . in a third phase, the compressible gas expands and moves violently the striking piston 18 downward impacting the tool 19 with sufficient force to break a rock.

The damper 28 comprises a body 27 coinciding with the body 23 of the striking cell 14 and a closing piston 30 movable in translation in the body 23. The closing piston 30 comprises a body 44 whose diameter is adapted to the diameter of the chamber 22. This body 44 is provided with an annular groove in which is inserted a seal 43 sealing the chamber 22. The closing piston 30 comprises a head 45 integral with the body 44. The head 45 is intended to come into contact with a closure plate 20b. The closing piston 30 thus makes it possible to effectively seal the chamber 22 and to block the striking cell 14 in the housing 15.

Preferably, the closing piston 30 is dimensioned such that, when the chamber 22 is under pressure, the pressure of the chamber 22 on the closing piston 30 is greater than the thrust force of the arm 12 of the carrier vehicle 11 on the closing plate irrespective of the position of the striking piston 18.

In the example of Figures 4 to 6 , the closing plate 20b is formed by the fixing plate 16 intended to fix the arm 12 of a carrier machine 11. The casing 15 comprises a fixing plate 21 intended to cooperate with the fixing plate 16 to fasten the apparatus Hydraulic percussion 10b on the arm 12 of a carrier 11. The attachment plate 21 of the housing 15 has a central recess in which the head 45 of the closing piston 30 penetrates to make contact with the fixing plate 16.

In order to mount the hydraulic percussion apparatus 10b, the tool 19, the striking piston 18 and the closing piston 30, are successively inserted into the body 23 of the striking cell 14. After the insertion of the 19, the keys 17 are inserted to constrain in rotation and in translation the movements of the tool 19. The striking piston 18 is moved in the body 23 in abutment against the tool 19, so that the chambers 37, 38 can control the movements of the striking piston 18. The closing piston 30 is then inserted into the body 23 above the striking piston 18. The fixing plate 21 of the housing 15 is fixed with the fixing plate 16 for fixing the arm 12 of a carrier vehicle 11. Finally, the gas is then introduced into the chamber 22 by means of a fluid inlet 33 moving the closing piston 30 against the fixing plate 16.

In the example of the Figure 7 , a hydraulic percussion apparatus 10c comprises an upper chamber 37 for controlling the striking piston 18 disposed above the striking piston 18 in a pressure accumulator 51. The pressure accumulator 51 comprises a pneumatic circuit 53 arranged above of the upper chamber 37. The pneumatic circuit 53 and the upper chamber 37 are connected by a deformable membrane 52 so that the pressure variations of the upper chamber 37 are absorbed by the pneumatic circuit 53 via the deformable member 52 . the damper 28 is disposed on the pressure accumulator 51 and the chamber 22 of the damper 28 is in pneumatic communication with the pneumatic circuit 53 the pressure accumulator 51 by means of a channel 54. Thus, the pressure variations of the upper chamber 37 are absorbed by both the pneumatic circuit 53 and the damper 28.

It follows from the above that the percussion hydraulic devices 10a, 10b, 10c according to the invention have multiple advantages, and in particular in terms of ease of assembly, compensation of manufacturing tolerances, and simplicity related to the elimination of additional suspension device.

Claims (9)

1. A hydraulic percussion device (10a, 10b, 10c) intended to be installed on a carrier machine (11), the device comprising:

   - a housing (15) comprising a closing plate (20a, 20b),

   - a power cell (14) mounted in the housing (15) comprising an impact piston (18) that is movable in translation, and

   - a damper (28) connecting the power cell (14) and the closing plate (20a, 20b) in such a way as to transmit the displacement forces applied on the housing (15) to the power cell (14),

   characterized in that the damper (28) comprises:

   - a body (27) rigidly connected to the power cell (14) opposite the closing plate (20a, 20b),

   - a chamber (22) provided inside the body (27), and

   - a closing piston (30) which is movable inside the chamber (22) and capable of abutting against the closing plate (20a, 20b) in order to seal the chamber (22),

   - the chamber (22) being intended to contain a compressible fluid for damping the movements of the power cell (14) in relation to the housing (15).
2. The device according to claim 1, characterized in that at least one portion of the impact piston (18) is intended to penetrate into the chamber (22) in such a way that, when the chamber (22) contains a compressible fluid, the displacement of the impact piston (18) inside the chamber (22) is capable of compressing the compressible fluid, and the decompression of the compressible fluid is capable of displacing the impact piston (18).
3. The device according to claim 1, characterized in that the power cell (14) is connected to a pressure accumulator (51) comprising a hydraulic circuit (37) and a pneumatic circuit (53) separated by a deformable membrane (52), the chamber (22) is in pneumatic communication with the pneumatic circuit (53) of the pressure accumulator (51) so that the pressure contained in the hydraulic circuit (37) is transmitted to the chamber (22) by means of the membrane (52).
4. The device according to claim 1, characterized in that, the power cell (14) being sealed by a cover (32), the body (27) comprising the chamber (22) is mounted on said cover (32).
5. The device according to any one of claims 1 to 4, characterized in that the closing piston (30) comprises:

   - a body (44), intended to ensure the sealing of the chamber (22), and,

   - a head (45), intended to ensure that the closing piston (30) is maintained against the closing plate (20).
6. The device according to claim 5, characterized in that the body (44) of the closing piston (30) comprises a groove containing a gasket (43) appropriate for the diameter of the chamber (22) and for an expected pressure in the chamber (22).
7. The device according to any one of claims 1 to 6, characterized in that the chamber (22) is intended to contain nitrogen in gaseous form.
8. The device according to any one of claims 1 to 7, characterized in that it comprises an element for rigidly attaching the housing (15) to the closing plate (20a, 20b), the attachment element being intended to attach the housing (15) to a carrier machine (11).
9. The device according to any one of claims 1 to 7, characterized in that it comprises an attachment element positioned on the housing (15) in an area away from the closing plate (20a, 20b), the attachment element being intended to attach the housing (15) to a carrier machine (11).

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