EP3569774A1 - Excavating machine comprising a steering tube that enables the rotation of the chassis - Google Patents

Abstract

The invention relates to an excavation machine (10) for making trenches in the ground comprising: • a lifting device provided with a mast having an upper end; • a guide tube (30) mounted at the upper end of said mast and extending along a longitudinal axis (A) directed towards the ground, the guide tube (30) comprising a fixed part (32) which is fixed to the mast as well as a movable part (34) which is rotatable relative to the fixed part around the longitudinal axis, the movable part of the guide tube having a coupling device (38); • a chassis (16), suspended from the mast, the lower part of the chassis carrying a device excavation (20) while the upper part comprises a coupling member (40) coaxial with the longitudinal axis, the chassis being able to be moved along said longitudinal axis between: o a coupled position in which the coupling member (40) is coupled in rotation with the coupling device (38) of the movable part of the guide tube to allow the chassis to pivot about the longitudinal axis, ando a decoupled position in which the coupling member (40) is decoupled from the coupling device (38) of the movable part of the tube guide.

Description

Background of the invention

The present invention relates to the field of soil excavation tools, and more particularly, but not exclusively, excavation machines type grab.

Clams, also called buckets, are generally used to make walls in the ground, for example molded or prefabricated walls. They can also be used to make sealing screens or bars.

Clamshells traditionally comprise a frame which are articulated two buckets, also called "pockets", arranged symmetrically with respect to a vertical plane. Each bucket conventionally consists of two side walls that extend on either side of a concave geometry back, so as to form a kind of trough. The buckets can be swiveled by pivoting arms, actuated by jacks or cables, to open and close the clamshell. The buckets are provided with teeth.

Some excavating machines, and particularly clamshell buckets, have a chassis whose lower end carries an asymmetrical excavation device. In the case of skips, this asymmetry is due to the fact that the buckets do not have the same number of teeth. This particular configuration is imposed by the fact that the teeth must overlap when the cups are in the closed position. The asymmetry of the grabs causes an undesired vertical deflection of the digging device. To compensate for this phenomenon, it is known to rotate the excavation device by half a turn about a vertical axis, preferably between each excavation step.

For some machines, as for example in the case of mechanically actuated skips, this pivoting is usually done manually. In other excavating machines, there is provided a motor for pivoting the frame carrying the excavating device.

For example, US 7,685,749 discloses a hydraulically actuated clamshell having a rotating joint for distributing the hydraulic oil in the bucket. In this type of configuration, the upper part of the rotary joint is fixed in order to keep the alignment of the hydraulic hoses with a circular distribution chamber, while the lower part is free to turn around a vertical axis. This rotary joint can be motorized.

In EP 0 872 596 , the rotary joint is mounted between the lower end of a telescopic tube and the upper end of the frame.

A disadvantage of the rotary joint is its rapid wear that may lead to leakage of hydraulic oils, which are likely to mix with the drilling mud and pollute the soil.

Object and summary of the invention

An object of the invention is to provide an excavating machine having a simplified mechanism for rotating the excavating device about a longitudinal axis.

To do this, the invention relates to an excavation machine for producing trenches in the ground according to claim 1.

It is thus understood that the pivoting of the frame about the longitudinal axis, preferably a vertical axis, is achieved when the frame is in the coupled position by virtue of the rotation of the movable portion of the guide tube. In the coupled position, the frame is guided in rotation by the movable portion of the guide tube, whereby it is possible to control the rotation of the frame.

Thus, according to the invention, the coupling device of the movable portion rotates about the longitudinal axis of the guide tube so as to rotate the guide member, and therefore the frame, about this longitudinal axis.

The coupling device and the coupling member may advantageously have a mechanically simple structure, for example a square section bar and a square section tube.

The fact that the coupling member of the frame is coaxial with the longitudinal axis of the guide tube makes the coupling system more robust than that described in FIG. EP 0 872 596 .

Another advantage of the invention is that it also guides the excavating device during its introduction into the trench, and to avoid a deviation of the path of the excavating device. It is clear that the user of such a machine most often seeks to build a trench that is vertical over its entire height. The control of the trajectory is therefore an important aspect of an excavation operation, especially when the chassis is mounted pendulously at the end of cables. The invention provides a simple and effective solution to this problem.

Preferably, the guide tube is connected to the mast by means of an upper gimbal.

Preferably, the operation of excavating the trench is performed when the frame is in the decoupled or partially decoupled position. Still more preferably, the transition to the decoupled position is performed at the moment when the excavating device enters the trench or at least is introduced between guide walls disposed at the entrance of the trench.

According to one variant, the mobile part is a telescopic tube, which makes it possible, for example, to facilitate the emptying of the buckets above a truck when the excavating machine is a grab bucket.

Preferably, the coupling device of the movable portion of the guide tube is also coaxial with the longitudinal axis so that the coupling member of the frame and the coupling device of the movable portion of the guide tube are coaxial.

Preferably, the frame is suspended from the mast by means of at least one lift cable, and the displacement of the lift cable makes it possible to pass the chassis between its coupled position and its decoupled position.

Advantageously, the lift cable is fixed to the coupling member and extends inside the guide tube. In other words, the guide tube surrounds the lift cable. As a result, the presence of the guide tube according to the invention does not affect the movement of the lifting cable, nor the excavation operations.

Advantageously, the excavating machine according to the invention further comprises a motor means fixed to the guide tube for rotating the movable portion of the guide tube relative to the fixed part, and the movable portion of the guide tube is arranged. below the fixed part of the guide tube.

Preferably, but not necessarily, the motor means is attached to the fixed portion of the guide tube. The motor means is for example an electric motor.

According to a preferred embodiment, the coupling member is a bar which, in the coupled position, engages in shape cooperation with the movable portion of the guide tube, whereas in the decoupled position, the bar is in position. outside the moving part of the guide tube. This mechanism, particularly simple to manufacture, allows the coupling operation without external intervention other than the longitudinal movement of the frame (for example by moving the lift cable).

To improve the coupling operation, the lower end of the movable portion advantageously has a divergent flared shape to facilitate the engagement of the bar in the movable portion of the guide tube.

To further improve the coupling / decoupling operation, the coupling member is fixed to the frame by means of a gimbal. An interest of the gimbal and compensate for any offset between the axis of the coupling device and the axis of the coupling member.

In the preferred embodiment, but not exclusively, the excavating machine is a grab bucket. According to the invention, the excavation device comprises two buckets pivotally mounted with respect to the chassis, the buckets being actuated by means of an actuating mechanism arranged in the chassis.

According to the invention, the actuating mechanism is actuated by an actuating cable which extends inside the coupling member.

Preferably, the buckets of the clamshell are brought into closed position when pulling on the actuating cable to raise it vertically towards the upper end of the mast. Conversely, the clamshell buckets are brought into the open position when the actuation cable is released.

This actuation cable extends in the longitudinal direction of the guide tube being substantially parallel to the lift cable. As a result, the actuating cable and the lifting cable both extend inside the guide tube. Preferably, only the actuating cable extends inside the coupling member of the frame.

Preferably, the coupling member is provided with a cable guide for holding the actuating cable away from the walls of the coupling member, in order to avoid wear of the actuating cable.

• on descend le châssis de manière à amener le dispositif d'excavation en contact avec le sol ;
• on actionne le dispositif d'excavation afin de réaliser l'excavation d'une tranchée dans le sol, le châssis étant alors en position découplée ;
• on remonte le châssis de façon à amener le châssis en position couplée ;
• on fait pivoter la partie mobile du tube de guidage d'un demi-tour de manière à faire pivoter le châssis d'un demi-tour ;
• on descend le châssis pivoté dans la tranchée afin de poursuivre l'excavation de la tranchée.

The present invention also relates to a method of excavating soil with the aid of an excavating machine according to the invention, in which process:

• the chassis is lowered so as to bring the excavation device into contact with the ground;
• the excavation device is actuated in order to excavate a trench in the ground, the frame then being in the decoupled position;
• the chassis is raised to bring the chassis into the coupled position;
• the movable portion of the guide tube is rotated half a turn so as to rotate the frame one half turn;
• the frame is lowered into the trench to continue digging the trench.

When the excavating machine is a clamshell, a bucket emptying step is carried out after raising the frame in the coupled position.

Advantageously, the frame is brought into the coupled position when the excavating device leaves the trench, and is brought into the uncoupled position when the excavation device enters the trench. An interest is to control the trajectory of excavation devices when entering the trench and when leaving the trench.

Brief description of the drawings

• la figure 1 représente un exemple d'une machine d'excavation selon l'invention, à savoir une benne preneuse ;
• la figure 2 est une vue partielle, de côté, d'un premier mode de réalisation d'une machine d'excavation selon l'invention, à savoir une benne preneuse mécanique, dans laquelle le châssis est en position couplé ;
• la figure 3 illustre le début de la descente du châssis de la benne preneuse de la figure 2 , le dispositif d'excavation étant pris entre deux murets guide pendant que le châssis est amené vers sa position découplée ;
• la figure 4 illustre la poursuite de la descente du dispositif d'excavation dans la tranchée, le châssis étant alors en position découplée ;
• la figure 5 illustre la remontée du châssis et son passage en position couplée ;
• la figure 6 illustre le pivotement du châssis de 180° autour d'un axe vertical, les godets du dispositif d'excavation étant en position fermée ;
• la figure 7 illustre le début de la descente du châssis vers la tranchée, le châssis étant encore en position couplée ; et
• la figure 8 illustre l'étape d'ouverture des godets du dispositif d'excavation de la benne preneuse de la figure 2 .

The invention will be better understood on reading the following description of two embodiments of the invention given as non-limiting examples, with reference to the appended drawings, in which:

• the figure 1 represents an example of an excavating machine according to the invention, namely a grab bucket;
• the figure 2 is a partial view, from the side, of a first embodiment of an excavating machine according to the invention, namely a mechanical grab, in which the frame is in the coupled position;
• the figure 3 illustrates the beginning of the descent of the chassis of the clamshell of the figure 2 , the excavating device being caught between two guide walls while the chassis is brought to its decoupled position;
• the figure 4 illustrates the continued descent of the excavation device in the trench, the frame then being in the decoupled position;
• the figure 5 illustrates the raising of the chassis and its passage in coupled position;
• the figure 6 illustrates the pivoting of the frame 180 ° about a vertical axis, the buckets of the excavating device being in the closed position;
• the figure 7 illustrates the beginning of the descent of the frame towards the trench, the frame being still in coupled position; and
• the figure 8 illustrates the bucket opening step of the bucket excavation device of the figure 2 .

Detailed description of the invention

On the figure 1 , An excavating machine 10 is shown according to the present invention. In the present case, the excavating machine is a clamshell 10 which comprises a hoist, in this case a crawler carrier 12, equipped with a mast 14 at the upper end of which is suspended a frame 16, by means of one or more levitation cables 18. The frame comprises an upper part 16a and a lower part 16b which carry an excavating device 20. In this example, the excavation device consists of two buckets 22 mounted pivotally relative to the frame 16, the buckets 22 being actuated by an actuating mechanism 24 disposed in the frame 16. In a manner known otherwise, the buckets 22 can be in the closed position as shown in FIG. figure 1 or in the open position in which the two buckets are distant from each other. As we see on the figure 1 , the frame and the lift cable 18 extend in a substantially vertical direction.

According to the invention, the excavating machine 10 further comprises a guide tube 30 which is mounted at the upper end 14a of the mast and which extends along a longitudinal axis A directed towards the ground. As we see on the figure 1 This longitudinal axis is substantially vertical in this example.

This guide tube comprises a fixed part 32 which is fixed to the mast and more exactly to the upper end of the mast, and a mobile part 34 in the form of a tube which is rotatable, with respect to the fixed part, around the longitudinal axis A. In this example, the excavating machine 10 further comprises a motor means 36 which is fixed to the guide tube for rotating the movable portion 34 of the guide tube 30 relative to the fixed part 32. Preferably, the movable portion 34 of the guide tube 30 is disposed below the fixed portion 32 of the guide tube 30. In this example, the drive means is disposed between the fixed portion 32 and the movable portion 34 of the guide tube 30.

According to the invention, the mobile part 34 of the guide tube 30 comprises a coupling device 38 which is situated in this example at the lower end of the mobile part 34.

As we see on the Figures 2 to 8 , The lower end of the movable portion 34 is open and has a divergent flared shape. In this example, the coupling device 38 of the guide tube 34 is constituted by the lower end 34a of the movable portion of the guide tube. Preferably, the section of the lower portion 34a of the movable portion of the guide tube has a square section.

Referring now to figures 2 and 6 it is noted that the upper portion 16a of the frame comprises a bar-shaped coupling member 40 which extends vertically from the upper end of the frame. According to the invention, the coupling member 40 is coaxial with the longitudinal axis A. It is added that the frame is provided for pivoting about the axis of the coupling member 40, that is to say around of the longitudinal axis A. In this example, the cross section of the coupling member is square. Advantageously, the dimensions of the section of the coupling member 40 correspond substantially to the dimensions of the section of the coupling device 38, or are slightly smaller, so that the coupling member 40 can be introduced into the moving part. of the guide tube 34 via the coupling device 38, that is to say via the opening in the lower end of the movable portion of the guide tube.

In this example, the section of the coupling member is identical over its entire length, although this is not essential.

It is therefore understood that the combination of the coupling member 40 and the coupling device 38 forms a mechanical coupling system in which the coupling member forms the male part while the coupling device 38 forms the female part. Without departing from the scope of the present invention, the male and female parts could be reversed.

In a manner known moreover, the vertical displacement of the frame 16 is operated thanks to the displacement of the lift cable 18.

According to the invention, the frame 16 has a coupled position in which the coupling member 40 is rotatably coupled with the coupling device 38 of the movable portion 34 of the guide tube 30 to allow the frame to pivot around the frame. longitudinal axis A through the rotation of the movable portion of the guide tube 30. In this case, the rotation of the movable portion 34 of the guide tube 30 is achieved by the motor means 36, which is in this example constituted by an electric motor.

It is understood that the coupling formed between the coupling member 40 and the coupling device 38 is obtained thanks to the shape cooperation between the square section of the coupling member 40 and the square section of the coupling device 38. Of course other section shapes or other types of coupling could be chosen without departing from the scope of the present invention.

Still according to the invention, the frame 16 also has a decoupled position in which the coupling member 40 is decoupled from the coupling device 38 of the movable portion 34 of the guide tube 30. In the decoupled position, the coupling member 40 lies outside the movable portion 34 of the guide tube 30 as can be seen in particular on the figure 4 .

It is understood that the displacement of the lift cable 18 allows the chassis 16 to pass between its coupled position and its decoupled position. With the aid of the figures, it is understood that the passage from the position coupled to the decoupled position is done by lowering the frame, thus releasing the lift cable 18, while the passage between the decoupled position and the coupled position is made going back up chassis, that is to say by pulling on the lift cable 18. As can be seen in particular on the figure 2 , the lifting cable 18 is fixed to the upper end 40a of the coupling member 40. In addition, the lifting cable 18 extends inside the guide tube 30. It is added that the motor means 36 further has an axial recess for the passage of cable and in particular the lift cable 18. In the coupled position, the frame 16 is adapted to be pivoted about the longitudinal axis A. More specifically, the frame 16 has a non-directional orientation. pivoted in which the frame 16 has not pivoted about its longitudinal axis A, and a pivoted position in which the frame has rotated 180 ° about the longitudinal axis A through the rotation of the movable portion 34 of the tube guidance 30. With the help of Figures 2 to 8 , Will now be described an example of soil excavation process carried out by using the excavating machine according to the invention. In a first step, the frame is brought over the area where it is desired to make a trench. In this example, the floor is previously equipped with guide walls 50 which define the thickness of the trench to be made. Once the frame is correctly positioned above the guide walls 50, the frame 16 is lowered so as to bring the excavation device 20 into contact with the ground. Advantageously, and as seen on the figure 3 , the frame 16 is brought from its coupled position of the figure 2 to its decoupled position while the excavating device is introduced between the guide walls 50 which flank the buckets 22.

In other words, it ensures control of the vertical path of the frame 16 when the latter is still guided by the guide tube 30 at the time the excavator begins to sink into the ground. On the figure 4 , the frame is shown in the decoupled position, that is to say that the bar 40 forming the coupling member has moved vertically relative to the movable portion of the guide tube which remains fixed so as to exit out of the movable part of the guide tube.

Conventionally, when the excavation device has penetrated into the ground, the buckets are actuated to perform the excavation of a trench in the ground. At this moment, the chassis is in decoupled position.

After closing the buckets 22, the frame 16 is raised so as to bring the chassis into the coupled position as shown on the figure 5 . In this position, the frame has a non-rotated orientation.

Then, the movable portion 34 of the guide tube 30 is pivoted by half a turn so as to rotate the frame one-half turn about the longitudinal axis A. Thus, as is understood in FIG. help from figure 6 , After emptying the contents of the cups, it descends the frame again (rotated 180 °) in the trench to continue the excavation of the trench, as has been shown in figure 7 . Again, the frame is brought to the decoupled position at the entrance of the excavation device in the trench during the descent of the frame. The operating principle of the invention being described, we will now be interested in two embodiments of the excavating machine 10 according to the invention.

Preferably, the coupling member 40 has a length of between 4 and 8 meters, preferably about 6 meters. This length may be different provided that it is sufficient for the coupling member 40 to be coupled again to the coupling device 38 when the buckets are at the entrance of the trench (for example at the level of guide webs arranged on both sides of the entrance to the trench). In addition, in the high position, the buckets must be able to empty into a construction dump truck.

According to the first embodiment of the invention, the excavating machine 10 consists of a mechanical type grab bucket. This is illustrated in particular on Figures 2 to 8 . In the first embodiment, the actuating mechanism 24 which is housed in the frame 16 is actuated by an actuating cable 60 which extends in a vertical direction parallel to the lift cable 18.

This actuating cable 60 also extends inside the guide tube 30. The actuating cable 60 further extends inside the coupling member 40 so as to be connected to the coupling mechanism. 24. The upper end of the coupling member 40 is further provided with a cable guide 62 for guiding the movement of the actuating cable 60 inside the coupling member 40. Cable guide 62 is for example provided with rotary rollers. Using the figure 8 it is understood that the release of the actuating cable 60 allows the opening of the buckets 22 while a traction operated on this cable actuating device 60 allows the closing of the buckets 22. This mechanism for actuating the buckets 22 with the aid of an actuating cable is known moreover.

Claims (10)

Excavating machine (10,100) for making trenches in the ground comprising: • a hoist (12) with a mast (14) having an upper end (14a); A guide tube (30) mounted at the upper end (14a) of said mast and extending along a longitudinal axis (A) directed towards the ground, the guide tube (30) having a fixed part (32) which is attached to the mast (14) and a movable portion (34) which is rotatable relative to the fixed portion about the longitudinal axis, the movable portion (34) of the guide tube (30) having a coupling device (38); characterized in that the excavating machine comprises: A chassis (16), suspended from the mast, having a lower part (16b) and an upper part (16a), the lower part of the chassis carrying an excavation device (20) while the upper part comprises a coupling member (40) coaxial with the longitudinal axis, the frame (16) being displaceable along said longitudinal axis (A) between: A coupled position in which the coupling member (40) is rotatably coupled with the coupling device (38) of the movable portion of the guide tube to allow pivoting of the frame about the longitudinal axis by virtue of the rotation of the movable portion of the guide tube, and A decoupled position in which the coupling member (40) is decoupled from the coupling device (38) of the movable portion of the guide tube, wherein the frame is suspended from the mast via at least one cable; lifting device (18), wherein the movement of the lift cable allows the frame to pass between its coupled position and its uncoupled position, wherein the excavating device (20) comprises two buckets (22) pivotally mounted relative to the frame, the buckets being actuated by means of an actuating mechanism (24,124) arranged in the frame, and in which the actuating mechanism (24) is actuated by an actuating cable (60) which extends inside the the coupling member (40). An excavating machine according to claim 1, wherein the lift cable (18) is attached to the coupling member (40) and extends inside the guide tube. Excavating machine according to claim 1 or 2, characterized in that it further comprises a motor means (36) fixed to the guide tube for rotating the movable portion of the guide tube relative to the fixed part, and in that the movable part (34) of the guide tube is arranged below the fixed part of the guide tube. Excavating machine according to any one of claims 1 to 3, wherein the coupling member (40) is a bar which, in the coupled position, engages in shape cooperation with the movable part (34) of the guide tube, while in the decoupled position, the bar is outside the movable portion of the guide tube. Excavating machine according to claim 4, wherein the lower end (34a) of the movable portion (34) has a divergent flared shape to facilitate the engagement of the bar in the movable portion of the guide tube. Excavating machine according to any one of claims 1 to 5, wherein the coupling member is fixed to the frame by means of a universal joint (41). Excavating machine according to any one of the preceding claims, wherein the coupling member is provided with a cable guide (62). Excavating machine according to any of the preceding claims, wherein the actuating cable (60) further extends within the guide tube (30). A method of excavating soil using an excavating machine according to any of claims 1 to 8, wherein • the chassis is lowered so as to bring the excavation device into contact with the ground; • the excavation device is actuated to perform the excavation of a trench in the ground, the frame then being in the decoupled position; • the chassis is raised to bring the chassis into the coupled position; Rotating the movable portion of the guide tube by half a turn so as to rotate the frame one half turn; • the frame is lowered into the trench to continue digging the trench. A method of excavating soil according to claim 9, wherein the frame is brought into the coupled position when the digging device exits the trench, and is brought to the decoupled position upon entry of the digging device into the trench .

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