Handling machine

Abstract

The invention relates to a handling machine (1) comprising: a chassis (2); a boom (3), a tool (5) or a tool-carrying frame (4) which is pivotally mounted on a front end of the boom (3); at least one tipping cylinder (25) which has a defined stroke between a first and a second tipping position, capable of causing a pivoting of the tool (5) or the tool frame (4) relative to the boom (3) and at least one compensation cylinder (30, 31) which is pivotally mounted on the boom (3) about a sixth axis (N) and on the front connecting rod (17) about a seventh axis (M) in such a way that during an upward movement of the boom (3) towards the extreme raised position, the compensation cylinder (30, 31) moves towards a first compensation position so that the tool (5) or the tool frame (4) pivots towards an extreme tipping position.

Description

Technical field

[0001] The invention relates to the field of handling machines comprising a pivotally mounted boom and a tool, such as a bucket for example, which is mounted articulated on the boom. Technological background

[0002] In the state of the art, handling machines are known in which the boom is pivotally mounted on the chassis by means of a deformable parallelogram type articulation device, i.e. comprising two connecting rods which are each pivotally mounted, on the one hand, on the chassis and, on the other hand, on the boom. The machines also comprise a lifting cylinder which is pivotally mounted, on the one hand, on the chassis and, on the other hand, on the boom and which thus makes it possible to move the boom between an extreme lowered position and an extreme raised position. Furthermore, a tool or a tool-carrying frame intended to receive a tool is pivotally mounted on one end of the boom and a dump cylinder makes it possible to pivot said tool or tool-carrying frame relative to the boom.Such articulation means are particularly advantageous in that the deformable parallelogram articulation device is such as to prevent, or at least limit, the longitudinal displacement of the center of gravity of the machine when the boom pivots. The risks of the machine tipping over are thus limited.

[0003] It is also known to equip handling machines of the aforementioned type with a compensation device which makes it possible to vary the stroke of the dump cylinder as a function of variations in the stroke of the lifting cylinder so as to maintain constant or substantially constant the inclination of the tool relative to the ground, when moving the boom between the extreme lowered position and the extreme raised position. These compensation devices comprise one or more compensation valves which are controlled as a function of the stroke of the lifting cylinder. A handling machine with a compensation device is for example known from document US 11 142 885 B2.

[0004] These handling machines are not fully satisfactory.

[0005] In particular, with a compensation device of the aforementioned type, the reliability of the compensation is variable since the operation of the compensation valve depends on the viscosity of the oil used and this varies according to the duration and conditions of use (in particular outside temperature). Summary

[0006] An idea underlying the invention consists of proposing a handling machine which does not have the aforementioned drawbacks, i.e. equipped with compensation means which make it possible to reliably maintain the inclination of the tool relative to the chassis, constant or substantially constant, during the movement of the boom.

[0007] According to a first aspect, the invention proposes a handling machine comprising: a chassis; and a boom which is mounted articulated on the chassis of the machine between an extreme lowered position and an extreme raised position by means of an articulation device comprising a front connecting rod and a rear connecting rod, the rear connecting rod being pivotally mounted on the chassis about a first axis and on the boom about a second axis, the front connecting rod being pivotally mounted on the boom about a third axis and on the chassis about a fourth axis, the first axis, the second axis, the third axis and the fourth axis being parallel to each other, a tool or a tool-holder frame which is intended to receive a tool, said tool or tool-holder frame being pivotally mounted on a front end of the boom about a fifth axis parallel to the first, second, third and fourth axes,said tool or tool-carrying frame thus being able to pivot in a first direction directed towards an extreme dumping position or in a second direction directed from the extreme dumping position towards an extreme digging position; at least one dumping cylinder which has a defined stroke between a first and a second dumping position, said at least one dumping cylinder being, on the one hand, associated with the boom and, on the other hand, associated, directly or indirectly by means of a rocker arm and a dumping connecting rod for example,to the tool or tool frame such that a movement of the dump cylinder towards the first dump position causes the tool or tool frame to pivot in the second direction and a movement of the dump cylinder towards the second dump position causes the tool or tool frame to pivot in the first direction; at least one compensation cylinder which has a defined stroke between a first and a second compensation position,said compensation cylinder being hydraulically connected to the dump cylinder so that a movement of said compensation cylinder towards the first compensation position causes a movement of the dump cylinder towards the second dump position and that a movement of said compensation cylinder towards the second compensation position causes a movement of the dump cylinder towards the first dump position; the compensation cylinder being pivotally mounted on the boom about a sixth axis and on the front connecting rod about a seventh axis in such a way that during an upward movement of the boom towards the extreme raised position, the compensation cylinder moves towards the first compensation position so that the tool or the tool holder frame pivots in the first direction and that during a downward movement of the boom towards the extreme lowered position,the compensation cylinder moves in the direction of the second compensation position so that the tool or tool frame pivots in the second direction.

[0008] Thus, the use of the aforementioned compensation cylinder does not have the disadvantages of the aforementioned compensation valve, in particular in that the reliability of the compensation which is ensured by the compensation cylinder no longer depends on the viscosity of the oil used. In addition, the arrangement of said compensation cylinder which acts between the front connecting rod and the boom is particularly compact and allows said compensation cylinder to be positioned in a configuration allowing it to ensure a substantially constant position of the tool or the tool-carrying frame relative to the chassis during movement of the boom, for at least one inclination of the tool or the tool-carrying frame relative to the chassis.

[0009] According to embodiments, such a handling machine may have one or more of the following characteristics.

[0010] According to one embodiment, the compensation cylinder is arranged to extend during a movement towards the second compensation position and to retract during a movement towards the first compensation position. Thus, the compensation cylinder is arranged to exert an assistance force participating with the lifting cylinder in the movement of the boom towards the extreme raised position. This makes it possible to restrict the dimensioning of the lifting cylinder and consequently its size, its cost and the flow rate of hydraulic fluid to be provided to actuate it.

[0011] According to one embodiment, the dump cylinder is arranged to extend during a movement towards the second dump position and to retract during a movement towards the first dump position.

[0012] According to one embodiment, the boom comprises two lifting arms extending on either side of a longitudinal axis of the machine, the front connecting rod being arranged between the two lifting arms and being mounted articulated on each of the two lifting arms around the third axis. This contributes in particular to the compactness of the machine.

[0013] According to one embodiment, the machine comprises two compensation cylinders which are positioned on either side of the front connecting rod and which are respectively pivotally mounted on one and the other of the two lifting arms around the sixth axis and are pivotally mounted on the front connecting rod around the seventh axis, each of the two compensation cylinders being hydraulically connected to said tipping cylinder. This arrangement allows the compensation cylinders to exert forces on the boom and the front connecting rod which are balanced relative to the median plane of the machine without however harming the compactness of the machine.

[0014] According to one embodiment, the dump cylinder comprises a first chamber and a second chamber which are separated from each other by a piston which is integral with a rod of the dump cylinder, said rod of the dump cylinder passing through the second chamber; the compensation cylinder comprising a first chamber and a second chamber which are separated from each other by a piston which is integral with a rod of said compensation cylinder, said rod of said compensation cylinder passing through the second chamber of said compensation cylinder, the first chamber and the second chamber of the dump cylinder being hydraulically connected respectively to the first chamber and to the second chamber of the dump cylinder.

[0015] According to one embodiment, the tipping cylinder and the compensation cylinder are arranged so that, from a determined position of the tool-carrying frame or the tool when the boom is in the extreme lowered position, the angular movement Δα1 of the tool-carrying frame or the tool relative to the boom around the fifth axis during a movement of the boom from the extreme lowered position to the extreme raised position is between -Δα2-x and -Δα2+x; with: Δα2: the angular movement of the boom relative to the chassis during a movement of the boom from the extreme lowered position to the extreme raised position; and x = 20°.

[0016] According to one embodiment, the predetermined position of the tool frame or the tool when the boom is in the extreme lowered position is the extreme digging position. This makes it possible to ensure that the inclination of the tool relative to the chassis is maintained substantially constantly for the digging positions of the tool, i.e. those which are most critical to prevent material from escaping from the tool during movement of the boom.

[0017] According to one embodiment, the dumping cylinder is pivotally mounted on a balance beam and on the boom, a dumping connecting rod being pivotally mounted on the balance beam and on the tool-carrying frame or the tool.

[0018] According to one embodiment, the tipping cylinder is pivotally mounted on fixing ears each projecting upwards from a cross member connecting two lifting arms of the boom.

[0019] According to one embodiment, the boom comprises two lifting arms extending on either side of a longitudinal axis of the machine.

[0020] According to one embodiment, the frame comprises a projecting portion which projects upwardly between the two lifting arms, said projecting portion projecting beyond the two lifting arms when the boom is in the extreme lowered position.

[0021] According to one embodiment, the projecting portion comprises two uprights arranged between the two lifting arms respectively on either side of the longitudinal plane of the machine, the front connecting rod being pivotally mounted around the fourth axis between said uprights.

[0022] According to one embodiment, the chassis comprises two side members which extend longitudinally on either side of the longitudinal plane, between the two lifting arms, the side members being connected to each other by cross members, the two uprights of the projecting portion being respectively formed in one and the other of the two side members.

[0023] According to one embodiment, the front connecting rod comprises a bent portion which has an upwardly oriented concavity so that a front portion of the front connecting rod, located in front of said bent portion, is located between the two uprights of the projecting portion when the boom is in the extreme lowered position.

[0024] According to one embodiment, the machine does not have a cabin intended to accommodate a driver, which makes the machine particularly compact.

[0025] According to one embodiment, the first, second, third and fourth axes are positioned so that, during a movement of the boom between the extreme lowered position and the extreme raised position, the fifth axis moves horizontally over a distance h and vertically over a distance v with h less than 15% of v, preferably less than 10% of v, for example of the order of 7% of v. This makes it possible to significantly limit the risks of the machine tipping over since the center of gravity of the machine moves little in the longitudinal direction of the machine during movements of the boom.

[0026] According to one embodiment, the machine comprises a lifting cylinder which comprises a first end pivotally mounted on the boom and a second end pivotally mounted on the chassis.

[0027] According to one embodiment, the front connecting rod comprises a bent portion which has an upwardly oriented concavity so that a front portion of the front connecting rod, located in front of said bent portion, is located between the two uprights of the projecting portion when the boom is in the extreme lowered position. This contributes to the compactness and aesthetics of the machine.

[0028] According to one embodiment, the machine comprises two anti-friction pads which are respectively fixed on a lateral face of one and the other of the uprights so as to be positioned between said upright and one of the lifting arms when the boom is in the extreme lowered position. Thus, the anti-friction pads make it possible to limit the friction likely to occur between the boom and the projecting portion of the chassis, in the event of transverse bending of the boom.

[0029] According to one embodiment, the machine further comprises a body fixed to the chassis, said body having a central recess in which the boom is housed in the extreme lowered position.

[0030] According to one embodiment, the machine comprises a front axle and a rear axle, which are each mounted on the chassis along a transverse axis and are each equipped with two wheels, the machine further comprising an electric motor which is coupled to at least one of the front and rear axles via a transmission device.

[0031] According to one embodiment, the machine comprises an electrical energy storage device comprising one or more batteries and connected to the electric motor, said electrical energy storage device being arranged in a housing space of the bodywork, positioned behind the rear axle. This makes it possible to form a counterweight intended to compensate for the load carried by the tool. Brief description of the figures

[0032] The invention will be better understood, and other objects, details, characteristics and advantages thereof will appear more clearly during the following description of several particular embodiments of the invention, given solely for illustrative and non-limiting purposes, with reference to the accompanying drawings. [ fig.1 ] There Figure 1is a front right perspective view of a handling machine, according to one embodiment, in which the boom is shown in the transport position and equipped with a bucket. fig.2 ] There Figure 2 is a perspective view similar to that of the Figure 1 in which the arrow is shown in the transport position and without tools. fig.3 ] There Figure 3 is a side view of the handling machine in which the boom is shown in an extreme lowered position and equipped with a bucket. fig.4 ] There Figure 4 is a top view of the handling machine. fig.5 ] There Figure 5is a partial right side view of the handling machine with the boom in an intermediate position between the extreme raised position and the extreme lowered position and equipped with a bucket and in which only the chassis, the boom, its articulation device as well as the lifting, dumping and compensation cylinders are shown. fig.6 ] There Figure 6 is a partial right side view of the handling machine with the boom in the extreme raised position and in which only the chassis, the boom, its articulation device as well as the lifting, tipping and compensation cylinders are shown. fig.7 ] There Figure 7 is a partial front left perspective view of the handling machine with the boom in an extreme raised position and in which only the chassis, the boom, its articulation device as well as the lifting, tipping and compensation cylinders are shown. fig.8 ] There figure 8 is a schematic representation of the hydraulic control circuit. Description of the embodiments

[0033] By convention, the "longitudinal" direction of the handling machine corresponds to the front-rear orientation. Furthermore, the "transverse" direction is oriented perpendicular to the longitudinal direction. The terms "rear" and "front" correspond respectively to the abbreviations AR and AV indicated in the figures and are used to define the relative position of one element with respect to another in the longitudinal direction. The terms "front" and "rear" are adopted here in relation to the tool loading direction, i.e. the tool is positioned at the front of the machine. This definition does not prefigure the preferred direction of movement of the machine, which can therefore occur either forwards or backwards.

[0034] In reference to the figures 1 to 7, a handling machine 1 is described according to one embodiment. The machine 1 comprises a chassis 2, visible in the figures 5 to 7 , and an arrow 3 which is mounted articulated on the chassis 2 by an articulation device described below. In the embodiment shown, a tool-carrying frame 4, intended to receive a tool 5, is mounted articulated at the end of the arrow 3. By tool, we mean, for example, forks or a bucket, such as a simple bucket, a silage bucket, a distributor bucket or others. In another embodiment not shown, the machine 1 does not have a tool-carrying frame 4 and the tool 5 is mounted articulated permanently, that is to say in an irremovable manner, at the end of the arrow 3.

[0035] The chassis 2 is movable. To this end, in the embodiment shown, the machine 1 comprises two axles, a front axle 6 and a rear axle 7, which are each mounted on the chassis 2 along a transverse axis and are each equipped with two wheels, one on the left and the other on the right. At least one and preferably both the front 6 and rear 7 axles are steering axles, i.e. are equipped with means for varying the orientation of the wheels relative to the longitudinal direction of the machine 1.

[0036] Machine 1 has a body 8, visible on the figures 1 to 4 , which rests on the chassis 2 and is fixed to it. The body 8 has housing spaces for receiving equipment of the machine 1.

[0037] The machine 1 comprises at least one electric motor, not shown, which is fixed to the chassis 2 and which is coupled to at least one of the front 6 or rear 7 axles, or to both, by means of a mechanical or hydraulic transmission device. The machine 1 also comprises an electrical energy storage device, not visible, which comprises one or more batteries and which is connected to the electric motor in order to supply it with electrical energy. Advantageously, the electrical energy storage device is arranged in a housing space 9, shown for example in the Figure 1 , which is arranged at the rear of the bodywork 8, behind the rear axle 7. Taking this arrangement into account, the bodywork 8 has a height which decreases from the rear to the front.

[0038] The boom 3 comprises two lifting arms 12, 13 which extend longitudinally, parallel to each other and which are arranged on either side of the median longitudinal plane of the machine 1. The two lifting arms 12, 13 are connected to each other by means of crosspieces 14, 15, 16, for example visible on the Figure 4 .

[0039] The boom 3 is mounted to move relative to the chassis 2 between an extreme lowered position, shown in the Figure 3 , and an extreme raised position, shown on the Figure 6 . The arrow 3 is thus able to take a plurality of positions between the two aforementioned extreme positions and in particular a transport position, shown in the Figures 1 and 2 in which the tool-carrying frame 4 is positioned at a sufficient distance from the ground so as not to reduce the ground clearance of the machine 1.

[0040] The boom 3 is mounted articulated on the chassis 2 by means of an articulation device comprising two connecting rods, namely a front connecting rod 17 and a rear connecting rod 18, notably visible on the figures 5 to 7. The rear connecting rod 18 is, on the one hand, pivotally mounted on the chassis 2 about an axis A and, on the other hand, pivotally mounted on the boom 3 about an axis B. The front connecting rod 17 is, on the one hand, pivotally mounted on the boom 3 about an axis D and, on the other hand, pivotally mounted on the chassis 2 about an axis C. The four geometric axes A, B, C and D are parallel to each other and oriented transversely. The axes A, B, C and D thus define the vertices of a deformable quadrilateral. The axes A, B, C and D are positioned so that when the front connecting rod 17 and the rear connecting rod 18 straighten, the boom 3 tilts and the front end of the boom 3 rises relative to its rear end. According to an advantageous embodiment, the axes A, B, C and D are further positioned so that the articulation axis G of the tool-carrying frame 4 relative to the boom 3 moves only very little horizontally during the movement of the boom 3.Thus, according to an advantageous embodiment, during the movement of the boom 3 between the extreme lowered position and the extreme raised position, the articulation axis G moves vertically by a distance v and horizontally by a distance h; with h less than 15% of v, preferably less than 10% of v and for example of the order of 7% of v.

[0041] In the embodiment shown, this kinematics of the arrow 3 is obtained in particular thanks to the position of the axis C on a projecting portion 11 of the chassis 2, that is to say at a height greater than that of the axis A.

[0042] As represented in particular on the figures 1, 2 And 4, the body 8 has a central recess 19 in which the lifting arms 12, 13 as well as the front connecting rod 17 and the rear connecting rod 18 are housed at least partially when the boom 3 is in the transport position. The lifting cylinder 24 as well as the compensation cylinders 30, 31, described below, are also housed in the central recess 19 when the boom 3 is in the transport position. Furthermore, the lifting arms 12, 13 have a general shape which substantially follows the profile of the upper surface of the body 8, when the boom 3 is in the transport position. In other words, in the transport position of the boom 3, the lifting arms 12, 13 are, from the rear to the front, inclined downwards.The lifting arms 12, 13 further comprise a bent portion 20 whose concavity is oriented towards the ground so that the front end of said lifting arms 12, 13 is positioned in front of the chassis 2 and the bodywork 8 of the machine 1, when the boom 3 is in the transport position or in the extreme lowered position.

[0043] According to the embodiment shown, the rear connecting rod 18 comprises two articulation flanges which respectively carry an articulation axis cooperating with one and the other of the two lifting arms 12, 13. Furthermore, the front connecting rod 17 is positioned between the two lifting arms 12, 13. The front connecting rod 17 therefore extends in the median longitudinal plane of the machine 1. Furthermore, the front connecting rod 17 is articulated on a projecting portion 11 of the chassis 2 which projects, between the two lifting arms 12, 13, upwards, beyond said lifting arms 12, 13 when the boom 3 is in the transport position or in the extreme lowered position.

[0044] As represented in particular on the Figure 7, the projecting portion 11 comprises two uprights 21, 22, parallel to each other, and arranged between the two lifting arms 12, 13, respectively on either side of the median longitudinal axis of the machine 1. In the embodiment shown, the uprights 21, 22 are formed in a single piece with the two longitudinal side members of the chassis 2 which are connected to each other by crosspieces, and extend on either side of the median longitudinal plane, between the two lifting arms 12, 13.

[0045] According to an advantageous embodiment, the projecting portion 11 also makes it possible to absorb the forces exerted on the boom 3 in a transverse direction and tending to cause it to bend, which makes it possible to limit the risks of the boom 3 becoming irreversibly deformed. Furthermore, in the embodiment shown, the projecting portion 11 comprises anti-friction pads 23, visible in particular on the figures 3, 4 And 6, which are each fixed on a lateral face of one of the uprights 21, 22 of the projecting portion 11. The anti-friction pads 23 are thus each positioned between one of the uprights 21, 22 and one of the lifting arms 12, 13 when the boom is in the transport position or in the extreme lowered position. The anti-friction pads 23 are made of a material having a low coefficient of friction, such as polyamide 6 for example. The anti-friction pads 23 are each spaced transversely from one of the lifting arms 12, 13 by a determined clearance so that one of said lifting arms 12, 13 only comes into contact with the corresponding anti-friction pad 23 when said lifting arm 12, 13 is subjected to a transverse force causing it to flex in the direction of said anti-friction pad 23.

[0046] The front end of the front connecting rod 17 is housed in the space provided between the two uprights 21, 22. Furthermore, as shown in particular on the figures 7 and 8 , the front connecting rod 17 has a bent portion 39 whose concavity is oriented upwards. Thus, when the boom 3 is in the transport position or in the extreme lowered position, the front portion of the front connecting rod 17, that is to say that which is arranged in front of the bent portion 39 is also located between the two uprights 21, 22 of the projecting portion 11, which contributes to the compactness and aesthetics of the machine 1.

[0047] Machine 1 includes a lifting cylinder 24, particularly visible on the figures 5 to 7, allowing the boom 3 to be moved between the extreme lowered position and the extreme raised position. To do this, the lifting cylinder 24 has one end which is mounted articulated on the chassis 2 around a hinge axis E and another end which is mounted articulated on the boom 3 around a hinge axis F, the hinge axes E and F being parallel to A, B, C and D. Thus, when the lifting cylinder 24 deploys, it causes the boom 3 to move towards the extreme raised position. On the contrary, when the lifting cylinder 24 retracts, it causes the boom 3 to move towards the extreme lowered position.

[0048] The machine 1 comprises a tool-carrying frame 4 which is intended to be secured to a tool 5 and which is mounted articulated at the front end of the boom 3 around an axis G. The tool-carrying frame 4 is thus able to take a plurality of positions between two extreme positions, namely an extreme digging position and an extreme dumping position. A tipping cylinder 25 acts on the tool-carrying frame 4 via a rocker 26 so as to pivot said tool-carrying frame 4 (or the tool 5 if the latter is permanently mounted articulated on the boom 3) around the axis G, relative to the boom 3. The tipping cylinder 25 comprises a first end which is mounted articulated on the boom 3 around an axis H, parallel to the axes A, B, C and D.More particularly, in the embodiment shown, the first end of the tipping cylinder 25 is mounted articulated on two fixing ears 27, 28 which each project upwards from the crosspiece 15 connecting the two lifting arms 12, 13. The second end of the tipping cylinder 25 is mounted articulated on the rocker 26 around an axis I, parallel to H. As shown in particular on the . Figure 1 to 3, when the boom 3 is in the transport position or in the extreme lowered position, the fixing ears 27, 28 are located in front of the projecting portion 11, close to it. The fixing ears 27, 28 extend to a height lower than that of the projecting portion 11 when the boom 3 is in the transport position or below it. In other embodiments, the machine 1 may also comprise several, and in particular two, tipping cylinders 25. In this case, the tipping cylinders 25 are arranged parallel to each other and mounted articulated on the boom 3 and on the rocker 26 around the same geometric axes.

[0049] The two ends of the rocker arm 26 are respectively mounted articulated on the boom 3 around an axis J and on a tipping rod 29 around an axis K. Said tipping rod 29 is further mounted articulated around an axis L on the tool-carrying frame 4 so that the pivoting movement of the rocker arm 26 around the axis K causes the tool-carrying frame 4 to pivot around the axis G. The axes G, J, K and L are parallel to each other, as well as to the axes A, B, C and D and oriented transversely. The axes G, J, K and L thus define the vertices of a deformable quadrilateral.

[0050] In the configuration shown, when the dumping cylinder 25 deploys, it causes the tool-carrying frame 4 to pivot relative to the boom 3, around the axis G, in a first direction, i.e. in the direction of the extreme dumping position, whereas, on the contrary, when the dumping cylinder 25 retracts, it causes the tool-carrying frame 4 to pivot relative to the boom 3 in a second direction, i.e. in the direction of the extreme digging position.

[0051] Furthermore, the machine 1 comprises at least one compensation cylinder 30, 31 which is hydraulically connected to the tipping cylinder 25. In the embodiment shown, the machine comprises two compensation cylinders 30, 31, visible in particular on the Figure 7 , which are each hydraulically connected to the tipping cylinder 25.

[0052] As shown in the figure 8, the machine comprises a hydraulic control circuit which is configured to provide control of the lifting cylinder 24 and the dumping cylinder 25. The hydraulic circuit comprises in particular a reservoir 35, a pump 36 connected to the reservoir 35 as well as a flow-sharing distributor 37. The pump 36 is also supplied with electrical energy by the electrical energy storage device described above. The flow-sharing distributor 37 is configured to put the hydraulic fluid coming from the pump into communication with the lifting cylinder 24, with the dumping cylinder 25 or simultaneously with the lifting cylinder 24 and the dumping cylinder 25.

[0053] The dump cylinder 25 is a double-acting cylinder. In other words, it has two variable-volume chambers, namely a first chamber 38, on the bottom side, and a second chamber 40, on the rod side, which are separated from each other by a piston 41 which is integral with the rod 42 of the dump cylinder 25 and is housed in the body of said dump cylinder 25. In addition, the first chamber 38 and the second chamber 40 comprise a respective supply orifice by which said first or second chamber 38, 40 is connected to a line 43, 44 of the hydraulic circuit. Thus, when the hydraulic pressure in the first chamber 38 is greater than that in the second chamber 40, the tipping cylinder 25 extends whereas, on the contrary, when the hydraulic pressure in the second chamber 40 is greater than that prevailing in the first chamber 38, the tipping cylinder 25 retracts.Furthermore, according to an advantageous embodiment, the line of the hydraulic circuit leading to the second chamber 40 is equipped with a balancing valve 45 making it possible to block the outlet of hydraulic fluid from the second chamber 40 when the pressure difference between the two lines 43, 44 connected to the dumping cylinder 25 is abnormal and exceeds a threshold. In such a case, the balancing valve 45 prohibits the uncontrolled extension of the dumping cylinder 25, which prevents the movement of the tool 5 towards its extreme dumping position.

[0054] The lifting cylinder 24 is also a double-acting cylinder and also has two variable-volume chambers, namely a first chamber 46, on the bottom side, and a second chamber 47, on the rod side, which are separated from each other by a piston 48 which is integral with the rod 49 of the lifting cylinder 24. The lifting cylinder 24 is also associated with a balancing valve 50. However, the balancing valve 50 is here associated with the line 51 leading to the first chamber 46. The balancing valve 50 aims to prevent uncontrolled retraction of the lifting cylinder 24, which prevents the movement of the boom 3 towards the extreme lowered position.

[0055] The compensation cylinders 30, 31 are also double-acting cylinders which each comprise two variable-volume chambers, namely a first chamber 52, on the bottom side, and a second chamber 53, on the rod side, separated from each other by a piston 54 connected to the rod 55 of said compensation cylinder 30, 31. The first chambers 52, 53 of the compensation cylinders 30, 31 are hydraulically connected to the first chamber 38 of the tipping cylinder 25 while the second chambers 53 of the compensation cylinders 30, 31 are hydraulically connected to the second chamber 40 of the tipping cylinder 25. Thus, the retraction of the compensation cylinders 30, 31 causes the tipping cylinder 25 to extend while, on the contrary, the extensions of the compensation cylinders 30, 31 causes the tipping cylinder 25 to retract.

[0056] Returning to the figures 5 to 7, it is observed that the compensation cylinders 30, 31 are each pivotally mounted, on the one hand, on the front connecting rod 17 around an axis M, and, on the other hand, on one of the lifting arms 12, 13 around an axis N, the axes N and M being parallel to the axes A, B, C and D. The two compensation cylinders 30, 31 are respectively arranged on either side of the front connecting rod 17 and between the two lifting arms 12, 13.

[0057] The axis N is positioned, relative to the axis D of articulation of the front connecting rod 17, downwards and backwards. Thus, when the boom 3 is moved from the extreme lowered direction towards the extreme raised position, the compensation cylinders 30, 31 retract whereas, on the contrary, when the boom 3 is moved from the extreme raised position towards the extreme lowered position, the compensation cylinders 30, 31 extend.

[0058] Thus, taking into account the above arrangement, when the boom 3 moves towards its extreme raised position, the compensation cylinders 30, 31 retract which causes the extension of the dump cylinder 25 and, consequently, the movement of the tool-carrying frame 4 towards the extreme dumping position. On the contrary, when the boom 3 moves towards the extreme lowered position, the compensation cylinders 30, 31 extend which causes the retraction of the dump cylinder 25 and, consequently, the movement of the tool-carrying frame 4 towards the extreme digging position.

[0059] Furthermore, according to an advantageous embodiment, the compensation cylinders 30, 31 as well as the tipping cylinder 25 are arranged so that, from a determined position of the tool-carrying frame 4 or of the tool 5 when the boom 3 is in the extreme lowered position, the angular displacement Δα1 of the tool-carrying frame 4 or of the tool 5 around the axis G relative to the boom 3 during a movement of the boom 3 from the extreme lowered position to the extreme raised position is between -Δα2-x and -Δα2+x; with: Δα2: the angular displacement of the boom 3 relative to the chassis 2 during a movement of the boom 3 from the extreme lowered position to the extreme raised position; x: a tolerance of 20.

[0060] According to an advantageous embodiment, the determined position of the tool-carrying frame 4 or of the tool 5 relative to the boom 3 is the extreme digging position.

[0061] Thus, such an arrangement is advantageous in that the compensation cylinders 30, 31 make it possible to pivot the tool-carrying frame 4 or the tool 5 around the axis G in order to compensate for the angular movement of the boom 3 relative to the chassis 2 during the movement of the boom 3 so that the relative inclination of the tool-carrying frame 4 or the tool 5 relative to the chassis 2 remains constant or substantially constant.

[0062] Furthermore, the stroke L1 of the tipping cylinder(s) 25 corresponding to said aforementioned angular movement Δα1 is equal to n 2 × L 2 × S 2 n 1 × S 1 ; with : n1: the number of tipping cylinders 25 greater than or equal to 1; S1: the application surface of the piston 41, on the side of the first chamber 38 of each tipping cylinder 25 (equal to the section of the first chamber 38); n2: the number of compensation cylinders 30, 31 greater than or equal to 1; S2: the application surface of the piston 54 on the side of the first chamber 52 of each compensation cylinder 30, 31 (equal to the section of the first chamber 52); and L2: the stroke of each compensation cylinder 30, 31 corresponding to the aforementioned angular displacement Δα2.

[0063] Furthermore, in order for the compensation to operate in an identical manner during the movement of the boom 3 towards the extreme lowered position and towards the extreme raised position, the ratio between the application surfaces S1 and S3 of the piston 41, respectively directed towards the first and second chambers 38, 40 of each dump cylinder 25 is equal to the ratio between the application surfaces S2 and S4 of the piston 54, respectively directed towards the first and second chambers 52, 53 of each compensation cylinder 30, 31, i.e. S 3 S 1 = S 4 S 2 ; with : S3: the application surface of the piston 41 on the side of the second chamber 40 of each tipping cylinder 25 (equal to the section of the first chamber 38 minus the section of the rod 42); and S4: the application surface of the piston 54 on the side of the second chamber 53 of each compensation cylinder 30, 31 (equal to the section of the first chamber 52 minus the section of the rod 55).

[0064] In another embodiment not illustrated, the articulation axes H, I, M and N of the tipping cylinders 25 and compensation cylinders 30, 31 are moved so that said tipping cylinders 25 and compensation cylinders 30, 31 have reversed directions of actuation, that is to say that: on the one hand, the dumping cylinder 25 is mounted articulated on the boom 3 and the rocker arm 26 so that an extension of the dumping cylinder 25 causes the tool 5 or the tool-carrying frame 4 to pivot towards the extreme digging position and a retraction of the dumping cylinder 25 causes the tool 5 or the tool-carrying frame 4 to pivot towards the extreme dumping position; and that on the other hand, the compensation cylinders 30, 31 are mounted articulated on the boom 3 and the front connecting rod 17 so that a movement of the boom 3 towards the extreme raised position causes an extension of the compensation cylinders 30, 31 and a movement of the boom towards the extreme lowered position causes a retraction of the compensation cylinders 30, 31.

[0065] It should be noted, however, that, compared to this embodiment, the embodiment shown is advantageous in that the compensation cylinders 30, 31 make it possible to exert an assistance force participating with the lifting cylinder 24 in the movement of the boom 3 in the direction of the extreme raised position.

[0066] Furthermore, in the embodiment shown, the machine 1 is autonomous, that is to say that it is capable of moving and carrying out handling operations in an automated manner, without the intervention of a driver. The machine 1 is therefore devoid of a cabin intended to accommodate a driver, which makes it particularly compact. Furthermore, as shown in particular on the figures 1 to 4, the machine 1 comprises at least one spatial detection sensor 10, that is to say a sensor generating signals which comprise information representative of the position of the objects located in the environment of the machine 1. The spatial detection sensor 10 is fixed on the projecting portion 11, preferably at its top. The spatial detection sensor 10 is chosen from cameras and in particular stereoscopic cameras, time-of-flight cameras, LIDARS, radars and ultrasonic sensors. In the embodiment shown, the spatial detection sensor 10 is a stereoscopic camera. The machine 1 may also comprise at least one other spatial position sensor, which is advantageously of a different type from the spatial detection sensor 10 described previously and making it possible to ensure redundancy of the information collected.Machine 1 may in particular include other spatial position sensors, such as LIDARS for example, at the front and rear of machine 1, for example under its chassis 2.

[0067] Although the invention has been described in connection with several particular embodiments, it is obvious that it is in no way limited thereto and that it includes all technical equivalents of the means described as well as their combinations if these fall within the scope of the invention, as defined by the claims.

[0068] The use of the verb "comprise", "comprise" or "include" and its conjugated forms does not exclude the presence of other elements or other steps than those set out in a claim.

[0069] In the claims, any reference sign in parentheses cannot be interpreted as a limitation of the claim.

Claims

1. Handling machine (1) comprising: - a chassis (2); and - a boom (3) which is mounted articulated on the chassis (2) of the machine (1) between a lowered extreme position and a raised extreme position by means of an articulation device comprising a front connecting rod (17) and a rear connecting rod (18), the rear connecting rod (18) being pivotingly mounted on the chassis (2) about a first axis (A) and on the boom (3) about a second axis (B), the front connecting rod (17) being pivotingly mounted on the boom (3) about a third axis (D) and on the chassis (2) about a fourth axis (C), the first axis (A), the second axis (B), the third axis (C) and the fourth axis (C) being parallel to one another, - a tool (5) or a tool-holder frame (4) which is intended to receive a tool (5), said tool (5) or tool-holder frame (4) being pivotingly mounted on a front end of the boom (3) about a fifth axis (G) parallel to the first, second, third and fourth axes (A, B, C, D), said tool (5) or tool-holder frame (4) thus being capable of pivoting along a first direction directed to a discharge extreme position or along a second direction directed to a breakout extreme position; - at least one tipping cylinder (25) which has a stroke defined between a first and a second tipping positions, said at least one tipping cylinder (25) being associated, on the one hand, with the boom (3) and, on the other hand, with the tool (5) or with the tool-holder frame (4), such that a movement of the tipping cylinder (25) to the first tipping position leads to a pivoting of the tool (5) or of the tool-holder frame (4) along the second direction and that a movement of the tipping cylinder (25) to the second tipping position leads to a pivoting of the tool (5) or of the tool-holder frame (4) along the first direction; characterised in that it comprises - at least one compensation cylinder (30, 31) which has a stroke defined between a first and a second compensation position, said compensation cylinder (30, 31) being hydraulically connected to the tipping cylinder (25), such that a movement of said compensation cylinder (30, 31) in the direction of the first compensation position leads to a movement of the tipping cylinder (25) in the direction of the second tipping position, and that a movement of said compensation cylinder (30, 31) in the direction of the second compensation position leads to a movement of the tipping cylinder (25) in the direction of the first tipping position; the compensation cylinder (30, 31) being pivotingly mounted on the boom (3) about a sixth axis (N) and on the front connecting rod (17) about a seventh axis (M), such that during a raising movement of the boom (3) in the direction of the raised extreme position, the compensation cylinder (30, 31) moves in the direction of the first compensation position, such that the tool (5) or the tool-holder frame (4) pivots along the first direction, and that during a lowering movement of the boom (3) in the direction of the lowered extreme position, the compensation cylinder (30, 31) moves in the direction of the second compensation position, such that the tool (5) or the tool-holder frame (4) pivots along the second direction.

2. Handling machine (1) according to claim 1, wherein the compensation cylinder (30, 31) is arranged to extend during a movement in the direction of the second compensation position and retract during a movement in the direction of the first compensation position.

3. Handling machine (1) according to claim 1 or 2, wherein the tipping cylinder (25) is arranged to extend during a movement in the direction of the second tipping position and retract during a movement in the direction of the first tipping position.

4. Handling machine (1) according to any one of claims 1 to 3, wherein the boom (3) comprises two lifting arms (12, 13) extending on either side of a longitudinal axis of the machine (1), the front connecting rod (17) being disposed between the two lifting arms (12, 13) and being mounted articulated on each of the two lifting arms (12, 13) about a third axis (D).

5. Handling machine (1) according to claim 4, comprising two compensation cylinders (30, 31) which are positioned on either side of the front connecting rod (17) and which are respectively pivotingly mounted on one and the other of the two lifting arms (12, 13) about a sixth axis (N) and are pivotingly mounted on the front connecting rod (17) about a seventh axis (M), each of the two compensation cylinders (30, 31) being hydraulically connected to said at least one tipping cylinder (25).

6. Handling machine (1) according to any one of claims 1 to 5, wherein the tipping cylinder (25) comprises a first chamber (38) and a second chamber (40) which are separated from one another by a piston (41) which is secured to a rod (42) of the tipping cylinder (25), said rod (42) of the tipping cylinder (25) passing through the second chamber (40); the compensation cylinder (30, 31) comprising a first chamber (52) and a second chamber (53), which are separated from one another by a piston (54) which is secured to a rod (55) of said compensation cylinder (30, 31), said rod (55) of said compensation cylinder (30, 31) passing through the second chamber (53) of said compensation cylinder (30, 31), the first chamber (38) and the second chamber (40) of the tipping cylinder (25) being hydraulically linked respectively to the first chamber (52) and to the second chamber (53) of the tipping cylinder (25).

7. Handling machine (1) according to any one of claims 1 to 6, wherein the tipping cylinder (25) and the compensation cylinder (30, 31) are arranged, such that, from a determined position of the tool-holder frame (4) or of the tool (5) when the boom (3) is in the lowered extreme position, the angular offset Δα1 of the tool-holder frame (4) or of the tool (5) with respect to the boom (3) about the fifth axis (G) during a movement of the boom (3) from the lowered extreme position to the raised extreme position is between -Δα2-x and -Δα2+x; with: Δα2: the angular offset of the boom (3) with respect to the chassis (2) during a movement of the boom (3) from the lowered extreme position to the raised extreme position; and X = 20°.

8. Handling machine (1) according to claim 7, wherein the predetermined position of the tool-holder frame (4) or of the tool (5) when the boom (3) is in the lowered extreme position is the breakout extreme position.

9. Handling machine (1) according to any one of claims 1 to 8, wherein the tipping cylinder (25) is pivotingly mounted on a balance wheel (26) and on the boom (3), and wherein a tipping connecting rod (29) is pivotingly mounted on the balance wheel (26) and on the tool-holder frame (4) or the tool (5).

10. Handling machine (1) according to any one of claims 1 to 9, wherein the boom (3) comprises two lifting arm (12, 13) extending on either side of a longitudinal axis of the machine (1), and wherein the chassis (2) comprises a projecting portion (11) which projects upwards between the two lifting arms (12, 13), said projecting portion (11) projecting beyond the two lifting arms (12, 13) when the boom (3) is in the lowered extreme position.

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