EP2112277B1 - Earthmoving vehicle and loading bucket for such an earthmoving vehicle - Google Patents

Description

TECHNICAL AREA

The present invention relates to the field of public works. More specifically, it relates to an earthmoving machine such as a loader-excavator, as well as a loading bucket for such an earthmoving machine.

PRIOR TECHNIQUES

There are several types of construction machinery, among which there are conventional loaders and excavators. The loaders have the function of picking up materials at ground level, so that they can then be dumped at a different place, for example in a bucket or on a pile. A conventional loader comprises a self-propelled frame and a front loading bucket, supported by one or more rigid arms and articulated to this self-propelled frame.

An excavator is used to dig into the ground. It conventionally comprises an articulated arm for maneuvering a toothed tool designed to be driven into the ground and dismember it.

An excavator can be designed so that it can also be used as a loader. It is then a loader-excavator whose articulated arm can be equipped, with the choice, of a digging tool or a bucket of loading. Such a bucket is loaded by being pushed on the ground, forwards, in the material to be picked up. The thrust then exerted on the loading bucket to advance it results from a displacement of the loader-excavator itself and it is transmitted by the articulated arm which, therefore, can be subjected to multiple efforts. In particular, this articulated arm can be biased when the pushed bucket encounters a resistance near only one of its two lateral ends. While it can therefore be subjected to very high value twists, the articulated arm must have a reasonable mass, especially in order to be able to easily maneuver a digging tool. The problem resulting from the fact that the articulated arm can be subjected to high torsion is even more acute when the articulated arm is offset laterally, insofar as this results in an increase in the lever arm of the left or right side of the bucket. loading, relative to the hinge area of this bucket on the articulated arm.

In the document FR-2 119,625 , it is described a earthmover having a member on which an arm carrying a shovel can bear. The thrust caused by an advance of the earthmoving machine is first transmitted from the frame to the arm, before reaching the shovel itself. This arm is therefore urged during shoving on the shovel, more or less depending on whether the direction of the reaction or attachment force of the shovel in the ground passes far or not from the arm support zone on the element of transmission. In addition, the articulation between the shovel and the arm is traversed by all the thrusts exerted on the shovel and is therefore very exposed.

The document US 4,464,093 describes a machine according to the preamble of claim 1

SUMMARY THE INVENTION

The invention is at least intended to improve the ability of an earthmoving machine to exert a thrust on a loading bucket fitted to this machine.

According to the invention, this object is achieved by means of an earthmover, comprising a chassis carried by a rolling assembly, as well as an articulated arm for supporting and operating a tool such as a loading bucket. This earthmoving machine also comprises at least one support device for a loading bucket in a low pickup position. Through this support device, the chassis is able to exert a thrust on the loading bucket in a direction of movement of the earthmover, when the articulated arm holds the bucket in the low position of pickup.

When the bucket is on the support device, it is able to perform a recovery of effort so as to relieve the articulated arm, and a joint between the arm and the bucket. In particular, thanks to the invention, an earthmoving machine can be designed so as to be able to exert many strong thrusts on a bucket, without that ensues a malfunction or premature wear of the support arm of this bucket.

The loading bucket is a tool that can be mounted on the articulated arm via a tool holder and that is part of a work head articulated to this arm. It will be noted that the invention has the advantage of being compatible with proven and effective architectures for coupling the working head to the actuating actuator of this working head around its tilting axis.

Advantageously, this machine comprises a second support device through which the frame can exert a thrust on a loading bucket, in said direction of movement, when the articulated arm holds this bucket in the low position of pickup, the one and the other support device being offset horizontally from one another.

Advantageously, the one and the other support device are positioned in such a way that, when it holds the bucket in the lower pickup position, the articulated arm is located between these two support devices so that be that little or no stress in torsion when loading the bucket by moving the bucket on the ground.

Advantageously, the earth-moving machine is more precisely a loader-excavator which comprises a reversible coupling tool holder of a tool at a distal end of said articulated arm, that is to say at the furthest end of the chassis, and of which this articulated arm comprises a succession of several tilting segments in substantially vertical planes.

Advantageously, the tilting segments of the articulated arm comprise a distal segment and several other tilting segments, each of which is movable between first and second end-of-travel positions such that, when each of these several other tilting segments is immobilized in its first end position stroke, the low bucket loading position is reached by only tilting the distal segment around a proximal end of this distal segment.

Advantageously, the machine comprises a joint between a distal end of the articulated arm and the bucket carried by this articulated arm, the support device defining a substantially horizontal alignment axis with which the axis of said articulation substantially coincides, when the articulated arm holds the bucket in said lower pickup position, and around which the bucket tilts while resting on the support device when the axis of the joint and the alignment axis coincide.

Advantageously, the support device comprises a bearing surface of the bucket in its low collector position, this bearing surface having a concavity which has a constant radius of curvature and centered on said alignment axis.

Advantageously, the support device comprises a guide slot pierced in the bearing surface.

Advantageously, the support device comprises a scraping transverse blade movable between a low scraping position and a high position in which the bucket can come into abutment against the support device by placing itself in its low collection position, said surface bearing at a front face of the transverse scraping blade.

Advantageously, the support device comprises a support shoe and a hinge whose axis of rotation forms said alignment axis and through which the shoe is hinged so as to tilt about this axis of rotation.

Advantageously, said shoe is constituted by the foot of a stabilizer and is movable between a low support position of a portion of the earthmover and a high position in which the bucket can come into abutment against this shoe by placing itself in its low pickup position.

Advantageously, the earthmoving machine comprises a loading bucket that carries said articulated arm, this articulated arm being able to bring the bucket into a position where the bucket is resting on the support device and which is said low position pickup.

The invention also relates to a loading bucket for a earthmoving machine. This bucket comprises at least one pusher for receiving a thrust from the rear and transmission of this thrust generally in a direction of movement corresponding to the advance of the bucket forward for a pickup.

Advantageously, the pusher comprises a rear rolling device on a bearing surface of the earthmoving machine.

Advantageously, the rear rolling device comprises two rollers which have respective substantially horizontal axes of rotation and which are angularly offset from one another about a substantially horizontal axis of tilting of the bucket.

BRIEF DESCRIPTION OF THE DRAWINGS

• la figure 1 est une vue en perspective d'une chargeuse-excavatrice selon un premier mode de réalisation de l'invention ;
• les figures 2 et 3 sont des élévations latérales et schématiques analogues, qui représentent la même chargeuse-excavatrice que la figure 1 et qui en illustrent un fonctionnement en montrant deux positions possibles d'un godet de chargement de cette chargeuse-excavatrice ;
• la figure 4 est une vue en perspective de la portion avant d'une chargeuse-excavatrice selon un deuxième mode de réalisation de l'invention ;
• la figure 5 est une élévation latérale de la chargeuse-excavatrice partiellement représentée à la figure 4 ; et
• la figure 6 est une élévation latérale qui représente partiellement la même chargeuse-excavatrice que la figure 4, mais dans une configuration différente de celle de la figure 5. et qui montre comment un godet de cette chargeuse-excavatrice.

The invention will be better understood on reading the description which follows, given by way of nonlimiting example and with reference to the appended drawings, among which:

• the figure 1 is a perspective view of a loader-excavator according to a first embodiment of the invention;
• the figures 2 and 3 are similar lateral and schematic elevations, which represent the same loader-excavator as the figure 1 and which illustrate an operation by showing two possible positions of a loading bucket of this loader-excavator;
• the figure 4 is a perspective view of the front portion of a loader-excavator according to a second embodiment of the invention;
• the figure 5 is a side elevation of the loader-excavator partially represented in the figure 4 ; and
• the figure 6 is a side elevation that partially represents the same loader-excavator as the figure 4 but in a configuration different from that of the figure 5 . and who shows how a bucket of this loader-excavator.

POSSIBLE WAYS OF REALIZING THE INVENTION

On the figure 1 is shown a first embodiment of a self-propelled excavator-loader 1 according to the invention. This excavator-loader 1 comprises a chassis 2 supported by four driving wheels 3. This chassis 2 is equipped with a mobile turret 4, which is mounted so as to be pivotable about a vertical axis and which carries a driving cabin 5 and an articulated arm 6 for supporting and operating a tool.

In a manner known per se, the articulated arm 6 comprises three tilting segments in substantially vertical planes, that is to say around substantially horizontal axes. These three segments are mounted following each other by being articulated between them. The first of these is referenced 7 and is classically called the arrow. It is connected to the turret 4 by a hinge 8, so as to tilt about a substantially horizontal axis X ₁ -X ' ₁ .

The other two segments of the articulated arm 6 are the counter-arrow, referenced 9, and the arm, referenced 10. The counter-arrow 9 is connected to the arrow 7 by a hinge 11, so as to be able to tilt relative to the arrow 7, about a substantially horizontal axis X ₂ -X ' ₂ .

Opposite the hinge 11, the counter-boom 9 carries the arm 10, which is connected to it by a hinge 12 so as to be able to tilt about an axis X ₃ -X ' ₃ substantially horizontal and which is the distal segment of the articulated arm 6.

The maneuvers of the boom 7 with respect to the turret 4, against the boom 9 with respect to this boom 7 and the arm 10 with respect to this against-boom 9 are the fact of hydraulic cylinders, which are arranged in a known manner and only one is visible and referenced 6A to the figure 1 .

The distal end of the arm 10 is provided with a tool holder 14, which is articulated to it by means of a hinge 15 and on which can be mounted reversibly several removable tools of different types. The arm 10 carries a cylinder 13 for operating the tool holder 14 around the substantially horizontal axis X ₄ -X ' ₄ of the articulation 15. The coupling device of the tool holder 14 to the cylinder 13 comprises two links articulated to one another, namely a first rod articulated to the arm 10 and a second link articulated to the tool holder 14. Thus, these two links, a portion of the arm 10 and at least a portion of the tool holder 14 together form a deformable parallelogram on which the cylinder 13 acts to manipulate the tool holder 14 and, more generally, the working head that together form this tool holder and a tool equipping it.

On the figure 1 , the tool held by the tool holder 14 is a loading bucket 16 horizontally elongated. Its back, facing back, carries two left and right rear pushers 17, which are laterally offset from one another and which project in a direction inclined towards the rear. The pushers 17 protrude towards the rear of the back of the bucket 16.

The excavator-loader 1 further comprises two left and right stabilizers 18, each of which is articulated to the frame 2 so that it can be operated by a jack 19 between two positions. One of these two positions is that of Figures 1 to 3 , on which each stabilizer 18 forms a support device for the bucket 16. In their other position, these stabilizers 18 are directed towards the ground, in a manner known per se, so as to be able to bear on this ground. Each stabilizer 18 comprises a leg 20 and a pivoting shoe 21, which is articulated at the distal end of this leg by means of a hinge 22 and which more precisely forms a foot of the stabilizer 18.

A tool other than the loading bucket 16 may be mounted on the tool holder 14. For example, it may be a digging bucket, narrower than the bucket 16 and mounted so that its back is generally rotated to the top. When such a not shown digging bucket equips the loader-excavator 1, the articulated arm 6 performs complex movements during which each of its segments 7, 9 and 10 tilts around its proximal end.

When its articulated arm 6 is provided with the loading bucket 7, the loader-excavator 1 is intended to function as a loader. In this case, the joints 8 and 11 are fixed, since only the arm 10 is maneuvered. In other words, the arrow 7 and the counter-arrow 9 form a fixed subset. The arrow 7 is then immobilized in one of its two extreme positions or end positions, in which she is in abutment. It is the same with the counter-arrow 9. As a result, the configuration of the fixed subassembly of the articulated arm 6 is easily reached by placing the arrow 7 and the counter-arrow 9 in abutment .

By tilting about the axis X ₃ -X ' ₃ , the arm 10 can move the loading bucket 16 between an upper discharge position and a lower pickup position, which is that of the Figures 1 to 3 and in which the pushers 17 are supported on the lower faces of the shoes 21 as long as the latter are in their high position.

When the shoes 21 are in their high position, that is to say in their position of Figures 1 to 3 their respective pivot axes are aligned, i.e. coincide. They then form together an alignment axis X ₅ -X ' ₅ with which coincides the axis X ₄ -X' ₄ , that is to say the tilting axis of the bucket 16, when the latter is placed in its low pickup position. Thanks to this, the bucket 16 in its low collector position can tilt around the axis X ₄ -X ' ₄ while remaining in support against the shoes 21, which is illustrated by a comparison of figures 2 and 3 .

When the loader-excavator 1 is in its configuration of Figures 1 to 3 its bucket 16 can be filled by scraping on the ground. To do this, the loader-excavator 1 is moved forward in the direction of advance symbolized by the arrow A, so that the bucket 6 is driven forwards, on the ground, in the material to load. When this is done, the chassis 2 transmits its movement to the bucket 16 not only via the articulated arm 6. In fact, it also exerts a thrust via the stabilizers 18, which then form support devices for the 16. The pushers 17 receive this thrust and transmit it to the back of the bucket 16.

It follows from the above that the articulated arm 6 is not stressed during the pickup phase. In particular, it is not stressed in torsion, even if the cup 16 encounters resistance in the vicinity of one of its two lateral ends.

When filling is completed, the bucket 16 is lifted by the arm 10 which, to this end, swings upward in the direction indicated by arrow B _1, while the arrow 7 and the boom-against 9 remain immobile in relation to the turret 4.

To return the bucket 16 to its low pickup position, it is sufficient to tilt the arm 10 in the opposite direction B ₂ , until the pushers 17 abut the stabilizers 18. The action of bringing the bucket 6 in its low pickup position is extremely easy to control.

On the figure 4 is shown a loader-excavator 101 according to a second embodiment of the invention. In the following, this excavator-loader 101 is only described as distinguishing it from the excavator-loader 1. In addition, a reference used hereinafter to refer to a similar or equivalent portion of the loader-excavator 101 referenced to a portion of the loader excavator 1 is constructed by adding the reference 100 denoting that portion in the loader excavator 1. Thus are obtained including references of the articulated arm 106, boom 107, the joint 108, the counter-boom 109, the arm 110, the joints 111, 112 and 115 of the excavator-loader 101.

The frame 102 of the loader excavator 101 is supported by a rolling assembly that comprises two side tracks 103 instead of the four wheels 3. The chassis 102 is not provided with stabilizer. However, it is equipped with a scraping assembly which comprises a front blade 150 carried by a tilting support 151. This support 151 is articulated to the frame 102 so that the blade 150 can be operated by a cylinder 119 between a low position of scraping and a high position which is that of Figures 4 to 6 .

The front face 152 of the blade 150 forms a transversely elongate concavity. At this concavity, the front face 152 carries two plates 153, each of which is pierced with a generally vertical guide slot 154.

The rear end of each pusher 117 is provided with a rolling device which consists of two rollers 155 angularly offset from one another about the axis.

X ₄ -X ' ₄ tilting bucket 116, an angle noted α to the figure 6 . The front face of each plate 153 forms a running surface 156 for a pair of rollers 155, each of which has a substantially horizontal axis of rotation X ₆ -X ' ₆ . Like the front face 152, the running surfaces 156 form a concavity facing forward.

When the bucket 116 is in its low collector position, its two pushers 117 rest on the blades 150, via their rollers 155. The rolling surfaces 156 are cylindrical and centered on an alignment axis X ₅ -X ' ₅ with which the axis X ₄ -X' ₄ substantially coincides when the bucket 116 is in its low pickup position. Thanks to this, this bucket 116 can tilt around its pivot axis X ₄ -X ' ₄ while remaining in abutment against the plates 153, which is apparent from a comparison of figures 5 and 6 . In this, the rollers 155 roll on the surfaces 156 being guided by the cooperation of the longitudinal edges of the slots 154 with peripheral ribs 157, one team each roller 155.

Claims (10)

1. Earthmoving vehicle, incorporating a chassis (2; 102) carried on a mobile assembly (3; 103), with an articulated arm (6; 106) for mounting and operating a tool such as a loading bucket (16; 116), at least one support system (18; 150, 151, 153) for a loading bucket (16; 116) in a low pickup position, characterized in that the support system (18; 150, 151, 153) by means of which the chassis (2; 102) is able to exert thrust upon the aforesaid loading bucket (16; 116) in a direction (A) of movement of the earthmoving vehicle, when the articulated arm (6; 106) holds the bucket (16; 116) in the low pickup position, and
   characterized in that it incorporates an articulation (15; 115) between one distal end of the articulated arm (6; 106) and the bucket (16; 116) carried by the said articulated arm, with the support system (18; 150, 151, 153) defining an essentially-horizontal alignment axis (X₅-X'₅), with which the axis (X₄-X'₄) of the said articulation (15; 115) essentially coincides, when the articulated arm (6; 106) holds the bucket (16; 116) in the said low pickup position, and around which the bucket (16; 116) tips while remaining bearing against the support system (18; 150, 151, 153) when the axis (X₄-X'₄) of the articulation (15; 115) and the alignment axis (X₅-X'₅) coincide.
2. Earthmoving vehicle in accordance with claim 1, characterized in that the support system (150, 151, 153) incorporates a bearing surface (156) for the bucket (116), in its low pickup position; this bearing surface (156) incorporates a concavity that has a radius of curvature that is constant and centered on the said alignment axis (X₅-X'₅).
3. Earthmoving vehicle in accordance with claim 2, characterized in that the support system (150, 151, 153) incorporates a guide slot (153) provided in the bearing surface (156).
4. Earthmoving vehicle in accordance with any one of claims 2 and 3, characterized in that the support system (150, 151, 153) incorporates a transversal scraper blade (150) that is movable between a low scraping position and a high position in which the bucket (116) can come to bear against the support system, while placing itself in its low pickup position, with the said bearing surface (156) being located level with a front face (152) of the transversal scraper blade (150).
5. Earthmoving vehicle in accordance with claim 1, characterized in that the support system (18) incorporates a bearing shoe (21) and an articulation (22) of which one rotation axis (X₅-X'₅) forms the said axis of alignment, and by which the shoe (21) is articulated in order to be able to tip around this rotation axis (X₅-X'₅).
6. Earthmoving vehicle in accordance with claim 5, characterized in that the said shoe is constituted by the foot (21) of a stabilizer (18), and is movable between one low position of supporting one part of the earthmoving vehicle and one high position in which the bucket (16) can come to bear against this shoe (21), while placing itself in its low pickup position.
7. Earthmoving vehicle in accordance with any one of the preceding claims, characterized in that it involves a loader/excavator that has a tool holder (14) for a reversible coupling of a tool (16; 116) to one distal end of the said articulated arm (6; 106), with the articulated arm incorporating a succession of multiple segments (7, 9, 10; 107, 109, 110) that tip in essentially-vertical planes.
8. Earthmoving vehicle in accordance with claim 7, characterized in that the tipping segments of the articulated arm (6; 106) incorporate a distal segment (10; 110) and multiple other tipping segments (7, 9; 107, 109), with each being movable between the first and second end-of-travel positions such that, when each of these multiple other tipping segments (7, 9; 107, 109) is immobilized in its first end-of-travel position, the low loading position of the bucket (16; 116) is attained with only a tipping (B₂) of the distal segment (10; 110) around one proximal end of this distal segment.
9. Earthmoving vehicle in accordance with any one of the preceding claims, characterized in that it incorporates a second support system (18; 150, 151, 153) by means of which the chassis (2; 102) can exert thrust on a loading bucket (16; 116), in the said direction of movement (A), when the articulated arm (6; 106) holds the said bucket in the said low pickup position, with both support systems (18; 150, 151, 153) being offset horizontally in relation to each other.
10. Earthmoving vehicle in accordance with any one of the preceding claims, characterized in that it incorporates a loading bucket (16; 116) carried by the said articulated arm (6; 105), with this articulated arm being able to bring the bucket (16; 116) into a position in which the bucket (16; 116) is bearing against the support system (18; 150, 151, 153), and which is the said low pickup position.

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