EP3822416A1

EP3822416A1 - Construction machine provided with an improved working arm

Info

Publication number: EP3822416A1
Application number: EP20208267.3A
Authority: EP
Inventors: Sandro Mastroianni; Vito Martucci; Marilena Bellino
Original assignee: CNH Industrial Italia SpA
Current assignee: CNH Industrial Italia SpA
Priority date: 2019-11-18
Filing date: 2020-11-18
Publication date: 2021-05-19
Anticipated expiration: 2040-11-18
Also published as: EP3822416B1; IT201900021429A1

Abstract

Construction vehicle (1) provided with a body (2) carried by an undercarriage (3) configured to move on ground, and a working arm (4) carried by the body (2) and a working element (5) carried by the working arm (4), the working arm (4) comprising a plurality of booms (4a, 4b, 4c) hinged one with respect to the other via respective hinges (6, 7, 8, 9) between the working element (5) and the body (2), the construction vehicle (1) further comprising locking means (12) configured to lock at least two among the hinges (6, 7, 8, 9) thereby coupling together two among the booms (4a, 4b, 4c) or one among the booms (4a) and the body (2).

Description

TECHNICAL FIELD

The present invention concerns a construction machine, in particular an earth-moving machine such as an excavator provided with an articulated working arm.

BACKGROUND OF THE INVENTION

Earth-moving machines such as excavators are provided with a working arm that is hinged to vehicle's body at a first extremity and that is provided with a working element, e.g. a bucket, at its opposite extremity.
Such working arm may be a single arm or, more frequently, comprises a pair of booms hinged one to the other between the working element and the vehicle's body.
Such articulated working arm and the working element are actuated by substantially simple hydraulic circuits, e.g. via three cylinders and may reach a high digging depth. However, the working elements cannot be lifted up to reach high working heights.
Indeed, a different typology of vehicles is used in such conditions, called "demolition vehicles". Usually, such demolition vehicles cannot dig except thanks to very expensive modification to the arm design.
Therefore, the need is felt to provide a construction vehicle which can be used for both working operations, i.e. allowing high digging depth and at the same time allowing the work at high heights.
An aim of the present invention is to satisfy the above mentioned needs in an economic and optimized way.

SUMMARY OF THE INVENTION

The aforementioned aim is reached by a construction vehicle as claimed in the appended set of claims.

BRIEF DESCRIPTION OF DRAWINGS

For a better understanding of the present invention, a preferred embodiment is described in the following, by way of a non-limiting example, with reference to the attached drawings wherein:

Figure 1 is a schematic lateral view of a construction vehicle according to the present invention;
Figures 2A-2B are schematic lateral views of the construction vehicle according to the present invention in first operative conditions;
Figures 3A-3B are schematic lateral views of the construction vehicle according to the present invention in second operative conditions; and
Figures 4A and 4B are schematic section views through line IV-IV of figure 2A of a portion of the vehicle according to the present invention in two different operative conditions.

DETAILED DESCRIPTION OF THE INVENTION

Figure 1 discloses a construction vehicle 1, e.g. an excavator, comprising a body 2 carried in movable way by an undercarriage 3 movable with respect to the ground, e.g. thanks to a crawler belt.
Vehicle 1 further comprises a working arm 4 carried in movable manner by body 2 and provided with a working element 5, such as a bucket, at an extremity of the working arm 4 opposite to the connection with body 2.
According to an aspect of the invention, working arm 4 comprises three booms 4a, 4b, 4c, hinged one with respect to the other between the working element 5 and the body 2 of the vehicle 1.
In greater particular, a first boom 4a is hinged at a first extremity 4a' via a first hinge 6 to vehicle's body 2 and at a second extremity 4a" via a second hinge 7 to a first extremity 4b' of a second boom 4b. A second extremity 4b" of second boom 4b is then hinged via a third hinge 8 to a first extremity 4c' of a third boom 4c whose a second extremity 4c" is hinged via a fourth hinge 9 to the working element 5.
Each boom 4a, 4b, 4c can be operated thanks to a plurality of actuators, e.g. hydraulic cylinders. In particular, vehicle 1 comprises a first hydraulic cylinder 11a hinged between vehicle's body 2 and the firs extremity 4b' of the second boom, a second hydraulic cylinder 11b hinged between the first extremity 4b' of second boom 4b and the first extremity of third boom 4c and a third hydraulic cylinder 11c hinged between the first extremity of third boom 4c and the working element 5.
According to a further aspect of the invention, the vehicle comprises locking means 12 configured to selectively lock the first and the second hinges 6, 7, thereby selectively coupling together, respectively, first boom 4a to vehicle's body 2 and first boom 4a to second boom 4b.
In particular locking means 12 may be realized according to any typology of means configured to lock the rotation of two relative rotation elements.
Accordingly, locking means 12 may be alternatively manually actuated means, e.g. a pin to be inserted manually into a hole, or automatically actuated means, i.e. comprising an actuator (electro-mechanical, pneumatic or hydraulic) controller by a related control unit to selectively lock or unlock the two relative rotational elements.
Furthermore, locking means 12 may alternatively be integrated into the respective hinge 6, 7 or realized as separate elements with respect to this latter.
According to the embodiment of figures 4A- 4B, locking means 12 are mechanically manually operated locking means which are not integrated into the hinge 6 and comprising a pin 13 configured to be inserted into holes 14 realized in a protrusion carried by body 2 and a protrusion carried by first boom 4.
Such pin 13 is dimensioned to be inserted between such two set of holes 14 and it can be fixed axially into such position thanks to an axial locking element 15 such as a spline or a split pin, as shown. In such condition, the first boom 4 cannot move with respect to body 2, being locked by the coupling defined by pin 13 into holes 14.
The operation of the above described construction vehicle 1 is the following.
In a first operative condition, shown in figures 2A-2B, the first hinge 6 is locked while second hinge 7 is not locked. Accordingly, the first boom 4a has a preset fixed position with respect to vehicle's body 2 and the remaining booms 4b, 4c can be actuated independently so that they can reach a great working high (as shown in figure 2B).
In a second operative condition, shown in figures 3A-3B, the first hinge 6 is not locked while second hinge 7 is locked. Accordingly, the first and second booms 4a, 4b are locked together with respect to vehicle's body 2 and first cylinder 11a actuates the movement of both first and second booms 4a, 4b. In the meanwhile, third boom 4c can be actuated independently so that the vehicle can reach a high digging depth (See figure 3B).
In view of the above it is clear that the present invention is furthermore directed to a method for operating a construction vehicle 1 and that can be implemented into a control unit configured to control locking means 12 as described above when they are automatically actuated.
In such a case, the construction vehicle 1 may comprise sensors configured to detect the preset position of first boom 4a in order to proceed with the locking/unlocking of hinges 6, 7.
Such method comprises the phases of:

selecting a working mode of the construction vehicle 1; and
alternatively locking first and second hinges 6, 7 according to the selected working mode.

In view of the foregoing, the advantages of a construction vehicle 1 according to the invention are apparent.
Thanks to the presence of the three booms 4a, 4b, 4c and the two selectively locking hinges 6, 7 the proposed construction vehicle maintains the same, high, depth of excavation of a normal excavator while improves its performances in reaching great heights. Accordingly, the construction vehicle 1 is more versatile.
Furthermore, the control of the construction vehicle 1 via cylinders 11 is simpler both for its manufacturing both for the user which need to control only two cylinders in each working operation to move the booms (obviously the third cylinder is always present but it's voted for moving the working element 5).
Furthermore, compared to current demolition vehicles, the proposed construction vehicle has a less complex structure from both mechanical and hydraulic points of view, thereby allowing to reduce manufacturing time and costs.
It is clear that modifications can be made to the described construction vehicle 1 which do not extend beyond the scope of protection defined by the claims.
For example, it is clear that the proposed shapes and typology of booms 4 and vehicle 1 are merely indicatives and may vary according to the typology of construction vehicle.
Furthermore, locking means 12, hinges 6, 7, 8, 9 or actuators 11 may be of any typology provided that they have the same operation and scope as described in the preceding.

Claims

Construction vehicle (1) provided with a body (2) carried by an undercarriage (3) configured to move on ground, said construction vehicle (1) further comprising a working arm (4) carried by said body (2) and a working element (5) carried by said working arm (4) in a position opposite with respect to the coupling of said working arm (4) to said body (2), said working arm (4) comprising a plurality of booms (4a, 4b, 4c) hinged one with respect to the other via respective hinges (6, 7, 8, 9) between said working element (5) and said body (2), said construction vehicle (1) further comprising locking means (12) configured to lock at least two among said hinges (6, 7, 8, 9) thereby coupling together two among said booms (4a, 4b, 4c) or one among said booms (4a) and said body (2).
Construction vehicle according to claim 1, wherein said working arm (4) comprises a plurality of actuator cylinders (11a, 11b, 11c) configured to move said booms (4a, 4b, 4c) about the respective (6, 7, 8, 9).
Construction vehicle according to claim 1 or 2, wherein said working arm (4) comprises three booms (4a, 4b, 4c), a first boom (4a) being hinged via a first hinge (6) to said body (2), a second boom (4b) being hinged via a second hinge (7) to said first boom (4a) and via a third hinge (8) to a third boom (4c), this latter being further hinged via a fourth hinge (9) to said working element (5),
said construction vehicle (1) further comprising a first actuator cylinder (11a) between said second boom (4b) and said body (2), a second actuator cylinder (11b) between said second boom (4b) and said third boom (4c) and a third actuator cylinder (11c) between said third boom (4c) and said working element (5),
said construction vehicle (1) comprising locking means (12) configured to selectively lock said first boom (4a) to said body (2) and locking means (12) configured to lock said second boom (4b) to said first boom (4a).
Construction vehicle according to any of the preceding claims, wherein said locking means (12) are integrated into the respective hinge (6, 7, 8, 9).
Construction vehicle according to any of the preceding claims, wherein said locking means (12) are realized separated with respect to the respective hinge (6, 7, 8, 9).
Construction vehicle according to any of the preceding claims, wherein said locking means (12) are manually operated.
Construction vehicle according to any of the preceding claims, wherein said locking means (12) are automatically operated.
Construction vehicle according to claim 7, further comprising a control unit configured to control said locking means (12) on the base of preset configurations of said working arm (4).
Construction vehicle according to claim 8, further comprising sensor means configured to communicate with said control unit, which is configured to control the movement of said booms (4a, 4b, 4c) automatically in order to reach said preset configurations of said working arm (4).
Method for controlling a construction vehicle according to any of claims 7 to 9, comprising the phases of:
• selecting a working mode of the construction vehicle (1); and

• alternatively locking said hinges according to a selected preset configurations of said working arm (4).