EP3569774B1 - Excavating machine comprising a steering tube that enables the rotation of the chassis - Google Patents

Description

Background of the invention

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

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

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

Certain excavation machines, and in particular clamshells, have a frame, the lower end of which carries an asymmetric excavation device. In the case of buckets, 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 buckets are in the closed position. The asymmetry of the clams causes an unwanted vertical deflection of the excavator. To compensate for this phenomenon, it is known practice to make the excavation device pivot by half a turn around a vertical axis, preferably between each excavation step.

For certain machines, such as for example in the case of mechanically actuated skips, this pivoting is generally carried out manually. In other excavating machines, a motor is provided for pivoting the frame carrying the excavating device.

For example, US 7,685,749 describes a hydraulically actuated clamshell comprising a rotating joint which distributes 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 rotate around a vertical axis. This rotating joint can be motorized.

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

A drawback of the rotary joint is its rapid wear, which risks causing hydraulic oil to leak, which is liable to mix with the drilling mud and pollute the soil.

Purpose and summary of the invention

An object of the invention is to provide an excavating machine comprising a simplified mechanism allowing the rotation of the excavating device around a longitudinal axis.

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

It is therefore understood that the pivoting of the frame around the longitudinal axis, preferably a vertical axis, is carried out when the frame is in the coupled position thanks to the rotation of the movable part of the guide tube. In the coupled position, the frame is guided in rotation by the movable part of the guide tube, thanks to which it is possible to control the rotation of the frame.

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

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

The fact that the chassis coupling member is coaxial with the longitudinal axis of the guide tube makes it possible to make the coupling system more robust than that described in EP 0 872 596 .

Another advantage of the invention is that it also makes it possible to guide the excavation device during its introduction into the trench, in order to avoid a deviation of the path of the excavation device. It is in fact understood that the user of such a machine most often seeks to construct a trench which is vertical over its entire height. Controlling the trajectory is therefore an important aspect of an excavation operation, especially when the chassis is mounted in a pendulum at the end of the 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 carried out when the frame is in the decoupled or partially decoupled position. Even more preferably, the transition to the decoupled position is carried out when the excavating device enters the trench or at the very least is introduced between guide walls arranged at the entrance to the trench.

According to a 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 clamshell.

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

Preferably, the frame is suspended from the mast by means of at least one lifting cable, and the movement of the lifting cable allows the frame to pass between its coupled position and its decoupled position.

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

Advantageously, the excavating machine according to the invention further comprises a motor means fixed to the guide tube to drive the movable part of the guide tube in rotation with respect to the fixed part, and the movable part 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 part 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 by form cooperation with the movable part of the guide tube, while in the uncoupled position, the bar is located in outside the movable part of the guide tube. This mechanism, which is particularly simple to manufacture, makes it possible to carry out the coupling operation without external intervention other than the longitudinal displacement of the frame (for example by the displacement of the lifting cable).

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

To further improve the coupling / decoupling operation, the coupling member is fixed to the frame by means of a universal joint. An advantage of the gimbal is to 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 clamshell. According to the invention, the excavating device comprises two buckets mounted to pivot relative to the frame, the buckets being actuated by means of an actuation mechanism arranged in the frame.

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 the closed position when the actuating cable is pulled in order to raise it vertically towards the upper end of the mast. Conversely, the clamshell buckets are brought into the open position when the actuating cable is released.

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

Preferably, the coupling member is provided with a cable guide to keep the actuating cable away from the walls of the coupling member, in order to prevent 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 using an excavating machine according to the invention, a method in which:

• the frame is lowered so as to bring the excavating device into contact with the ground;
• the excavation device is actuated in order to carry out the excavation of a trench in the ground, the frame then being in the uncoupled position;
• the frame is raised so as to bring the frame into the coupled position;
• the movable part of the guide tube is rotated by half a turn so as to cause the frame to pivot by half a turn;
• the pivoted frame is lowered into the trench in order to continue the excavation of the trench.

When the excavating machine is a clamshell, a bucket emptying step is carried out after having reassembled 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 decoupled position when the excavating device enters the trench. One interest is to control the trajectory of the excavation devices when entering the trench and when exiting 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 by way of non-limiting examples, with reference to the appended drawings, in which:

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

Detailed description of the invention

On the figure 1 , there is shown an excavating machine 10 according to the present invention. In this case, the excavation machine is a clamshell 10 which comprises a lifting device, in this case a track carrier 12, equipped with a mast 14 at the upper end of which a frame 16 is suspended , by means of one or more lifting cables 18. The frame comprises an upper part 16a and a lower part 16b which carry an excavating device 20. In this example, the excavating device consists of two buckets 22 mounted to pivot relative to the frame 16, the buckets 22 being actuated by means of an actuating mechanism 24 arranged in the frame 16. In a manner known elsewhere, the buckets 22 may be in the closed position as shown in FIG. figure 1 or in the open position in which the two buckets are moved away from each other. As can be seen on the figure 1 , the frame and the lifting 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 seen 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, as well as a movable part 34 in the form of a tube which is rotatable, relative to the fixed part, around the pole. 'longitudinal axis A. In this example, the excavating machine 10 further comprises a motor means 36 which is fixed to the guide tube to drive the movable part 34 of the guide tube 30 in rotation with respect to the fixed part 32. Preferably, the movable part 34 of the guide tube 30 is arranged below the fixed part 32 of the guide tube 30. In this example, the motor means is placed between the fixed part 32 and the movable part 34 of the guide tube. 30.

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

As seen on figures 2 to 8 , the lower end of the movable part 34 is open and has a divergent flared shape. In this example, the coupling device 38 of the guide tube 34 is formed by the lower end 34a of the movable part of the guide tube. Preferably, the section of the lower part 34a of the movable part of the guide tube has a square section.

Referring now to figures 2 and 6 , it will be noted that the upper part 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 designed to pivot around 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 else are slightly smaller, so that the coupling member 40 can be inserted into the movable part. of the guide tube 34 via the coupling device 38, that is to say via the opening made in the lower end of the movable part 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 will therefore be understood that the association of the coupling member 40 and of 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 elsewhere, the vertical movement of the frame 16 is effected by the movement of the lifting 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 part 34 of the guide tube 30 in order to allow the frame to pivot around the frame. 'longitudinal axis A through the rotation of the movable part of the guide tube 30. In this case, the rotation of the movable part 34 of the guide tube 30 is achieved by the motor means 36, which in this example consists of an electric motor.

It will be understood that the coupling produced between the coupling member 40 and the coupling device 38 is obtained by virtue of the shape cooperation between the square section of the coupling member 40 and the square section of the coupling device 38. Of course. , other shapes of section 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 an uncoupled position in which the coupling member 40 is decoupled from the coupling device 38 of the movable part 34 of the guide tube 30. In the decoupled position, the coupling member 40 is located outside the movable part 34 of the guide tube 30 as can be seen in particular on the figure 4 .

It is understood that the movement of the lift cable 18 allows the frame 16 to pass between its coupled position and its uncoupled position. With the help of the figures, it can be understood that the passage from the coupled position to the decoupled position is made by lowering the frame, therefore by releasing the lift cable 18, while the passage between the decoupled position and the coupled position is made. going up the chassis, that is to say by pulling on the lifting cable 18. As can be seen in particular on the figure 2 , the lift cable 18 is fixed to the upper end 40a of the coupling member 40. In addition, the lift cable 18 extends inside the guide tube 30. It is added that the motor means 36 also has an axial recess allowing the passage of the cable and in particular of the lifting cable 18. In the coupled position, the frame 16 is therefore able to be pivoted about the longitudinal axis A. More precisely, the frame 16 has a non-orientation. rotated in which the frame 16 has not rotated about its longitudinal axis A, and a pivoted position in which the frame has rotated 180 ° around the longitudinal axis A by virtue of the rotation of the movable part 34 of the tube guidance 30. Using the figures 2 to 8 , we will now describe an example of the soil excavation method carried out using the excavation machine according to the invention. In a first step, we bring the frame above the area where we want to make a trench. In this example, the ground is first 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 excavating 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 towards its decoupled position while the excavating device is introduced between the guide walls 50 which flank the buckets 22.

In other words, it is ensured that the vertical trajectory of the chassis 16 is controlled as soon as the latter is still guided by the guide tube 30 when the excavating device 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 part 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 the ground, the buckets are actuated in order to carry out the excavation of a trench in the ground. At this time, the frame is in the uncoupled position.

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

Then, the movable part 34 of the guide tube 30 is rotated by half a turn so as to cause the frame to pivot by a half turn around the longitudinal axis A. Thus, as understood in help from the figure 6 , after emptying the contents of the buckets, the frame is lowered again (rotated by 180 °) into the trench in order to continue excavating the trench, as shown in the figure figure 7 . Here again, the frame is brought into the decoupled position when the excavating device enters the trench during the lowering of the frame. The operating principle of the invention having been described, we will now look at 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 can be different, provided that it is sufficient for the coupling member 40 to be still coupled to the coupling device 38 when the buckets are at the level of the entrance to the trench (for example at the level of guide walls arranged on either side of the entrance to the trench). In addition, in the upper position, the buckets must be able to empty into a construction dump truck.

According to the first embodiment of the invention, the excavation machine 10 consists of a mechanical type clamshell. This is particularly illustrated on the 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 lifting 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 linked to the mechanism d. 'actuation 24. The upper end of the coupling member 40 is further provided with a cable guide 62 making it possible to guide the movement of the actuator cable 60 inside the coupling member 40. This cable guide 62 is for example provided with rotating 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 actuation 60 allows the closing of the buckets 22. This actuation mechanism of the buckets 22 by means of an actuating cable is known elsewhere.

Claims (10)

1. An excavating machine (10, 100) for making trenches in the ground including:

   • a hoisting engine (12) provided with a mast (14) having an upper end (14a);

   • a steering tube (30) mounted at the upper end (14a) of said mast and extending along the longitudinal axis (A) oriented toward the ground, the steering tube (30) including a stationary part (32) that is fastened to the mast (14) and a moving part (34) that rotates relative to the stationary part around the longitudinal axis, the moving part (34) of the steering 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 bearing an excavating device (20) while the upper part includes a coupling member (40) coaxial to the longitudinal axis, the chassis (16) being able to be moved along said longitudinal axis (A) between:

   ∘ a coupled position in which the coupling member (40) is coupled in rotation with the coupling device (38) of the moving part of the steering tube so as to allow the pivoting of the chassis around the longitudinal axis due to the rotation of the moving part of the steering tube, and

   ∘ an uncoupled position in which the coupling member (40) is uncoupled from the coupling device (38) of the moving part of the steering tube, wherein the chassis is suspended from the mast by means of at least one lifting cable (18), wherein the movement of the lifting cable makes it possible to transition the chassis between its coupled position and its uncoupled position, wherein the excavating device (20) includes two buckets (22) mounted pivoting relative to the chassis, the buckets being actuated by an actuating mechanism (24, 124) arranged in the chassis, and wherein the actuating mechanism (24) is actuated by an actuating cable (60) which extends inside the coupling member (40).
2. The excavating machine according to claim 1, wherein the lifting cable (18) is fastened to the coupling member (40) and extends inside the steering tube.
3. The excavating machine according to claim 1 or 2, characterized in that it further includes a motor means (36) fastened to the steering tube in order to rotate the moving part of the steering tube relative to the stationary part, and in that the moving part (34) of the steering tube is arranged below the stationary part of the steering tube.
4. The excavating machine according to any one of claims 1 to 3, wherein the coupling member (40) is a bar that, in the coupled position, engages by shape matching with the moving part (34) of the steering tube, while in the uncoupled position, the bar is located outside the moving part of the steering tube.
5. The excavating machine according to claim 4, wherein the lower end (34a) of the moving part (34) has a divergent flared shape to facilitate the engagement of the bar in the moving part of the steering tube.
6. The excavating machine according to any one of claims 1 to 5, wherein the coupling member is fastened to the chassis via a Cardan joint (41).
7. The excavating machine according to any one of the preceding claims, wherein the coupling member is provided with a cable guide (62).
8. The excavating machine according to any one of the preceding claims, wherein the actuating cable (60) further extends inside the steering tube (30).
9. A ground excavating method using an excavating machine according to any one of claims 1 to 8, in which method:

   • the chassis is lowered so as to bring the excavating device into contact with the ground;

   • the excavating device is actuated so as to excavate a trench in the ground, the chassis being in the uncoupled position;

   • the chassis is raised so as to bring the chassis into the coupled position;

   • the moving part of the steering tube is pivoted by a half-revolution so as to pivot the chassis by a half-revolution;

   • the chassis is lowered pivoted in the trench in order to continue excavating the trench.
10. The ground excavating method according to claim 9, wherein the chassis is brought into the coupled position when the excavating device leaves the trench, and is brought into the uncoupled position when the excavating device enters the trench.

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