Patent Application
20220388817
The invention relates to a self-erecting crane, and more particularly to a self-erecting crane with a foldable jib.
A crane, known for example from document EP 0 733 584 A1, comprises a mast, generally a foldable mast or a telescopic mast, supporting a foldable jib comprising jib elements articulated together. Such a self-erecting crane is configurable between a transport configuration in which the mast and the jib are joined or folded together or side-by-side, and at least one work configuration in which the mast and the jib are deployed.
In the work configuration, the mast is substantially vertical (that is to say, extending in a direction parallel to the Earth's gravity force) and the jib is substantially horizontal. It could be considered to have a work configuration in which the mast is substantially vertical and the jib is inclined with respect to the horizontal, in other words the jib is raised with respect to the horizontal, such a work configuration being called a raised configuration; the inclination of the jib allowing setting the load closer or further away and thus avoiding at the same time mounting the crane too high. In the work configuration(s), with the jib horizontal or the jib raised, the crane is then suited to for lift and move loads.
In the transport configuration, the mast and the jib are folded against each other, horizontally, so as to occupy a reduced volume and be more easily transportable on the road.
Such a self-erecting crane comprises a motor-driven folding/unfolding system which is coupled to the mast and to the jib to act on the mast and on the jib in order to perform configuration change operations implementing kinematics of folding and unfolding the jib. The unfolding, also called deployment, corresponds to a mounting of the crane, that is to say the switch from the transport configuration into the work configuration. The folding corresponds to a dismantling of the crane, that is to say the switch from the work configuration into the transport configuration.
Conventionally, either a driver acts on the motor-driven folding/unfolding system to fold or unfold the crane, or a control/command system drives the motor-driven folding/unfolding system in automated folding or unfolding sequences, without any control being operated, with the exception of a visual control by the driver who ensures that the movements of the mast elements and of the jib elements are consistent. However, incorrect movement of any of these elements, for example due to a mechanical blockage which locks the movement, can lead to damage to the crane, or even to its complete immobilization while repairing or replacing it.
Also, the invention suggests implementing an automated control of the configuration change operations, for example in order to stop the operation in progress and/or to alert the driver.
Thus, the invention proposes a self-erecting crane comprising a mast supporting a jib, said jib being a foldable jib comprising jib elements articulated together, said self-erecting crane being configurable between a transport configuration in which the mast and the jib are joined together or side-by-side, and at least one work configuration in which the mast and the jib are deployed, said self-erecting crane comprising a motor-driven folding/unfolding system which is coupled to the mast and to the jib to act on said mast and on said jib in order to perform configuration change operations implementing kinematics of folding and unfolding the jib, and comprising a control/command system connected to the motor-driven folding/unfolding system to drive it and control the configuration change operations.
The self-erecting crane includes one or several inclinometer(s) mounted on one or several jib element(s) for measuring actual inclinations of said jib element or said several jib elements with respect to a reference axis.
The control/command system is configured to drive the motor-driven folding/unfolding system and to control the configuration change operations according to the actual inclinations of said jib element or of said several jib elements during kinematics of folding and unfolding the jib.
Thus, the inclinometer(s) allow(s) monitoring in real time the inclination of a jib element, or the inclinations of several jib elements, which allows controlling in real time the consistency of the movements of this jib element or of these jib elements during the kinematics of folding and unfolding the jib. In this way, the control/command system, connected to the inclinometer(s), can control the inclination of this jib element or the inclinations of these jib elements in different configurations (in particular intermediate or transient configurations) and thus validate these configurations (based on a modeling of the kinematics of folding and unfolding the jib) and also control and validate the movement of this jib element or the movements of these jib elements between two configurations (for example between the transport configuration and an intermediate configuration, or between two intermediate configurations, or between an intermediate configuration and the work configuration).
It should be noted that the motor-driven folding/unfolding system can comprise one or several actuator(s), and for example at least one cylinder-type actuator which is coupled to the mast to raise and lower it and at least one winch-type actuator (also called retaining winch) which comprises a drum on which a cable coupled to the jib to fold/unfold the jib is wound.
It should also be noted that the inclinometer(s) allow monitoring in real time the inclination of a jib element, or the inclinations of several jib elements, which also allows knowing the inclination of the mast in certain configurations in which the jib is folded against the mast. Indeed, at the start of the unfolding, whether in the transport configuration and in one or several intermediate configuration(s) which follow the transport configuration, the jib is folded against the mast, so that one or several inclinometer(s) can be used to monitor the inclination of the mast. Thus, the inclinometer(s) allow(s) controlling the inclination of other parts of the crane, such as the mast, in certain configurations.
According to one feature, the crane comprises at least two inclinometers mounted on two respective jib elements to measure the actual inclinations of said two jib elements with respect to the reference axis.
The use of at least two inclinometers allows monitoring at least two jib elements, thereby refining the monitoring of the kinematics of folding and unfolding the jib.
According to one variant, the crane comprises three inclinometers mounted on three respective jib elements to measure the actual inclinations of these three jib elements with respect to the reference axis.
According to one possibility, the jib elements comprise at least one first jib element, forming a jib foot, which is articulated on the mast, and a second jib element articulated on the first jib element, and wherein a first inclinometer is mounted on one of the first jib element and of the second jib element.
It is indeed advantageous to monitor the inclination of at least one of this first jib element and of the second jib element, because their positions mean that their movements are essential for understanding the kinematics of folding and unfolding the jib.
According to another possibility, a second inclinometer is mounted on the other one of the first jib element and of the second jib element.
In a particular embodiment, the jib occupies successive intermediate configurations between the transport configuration and the work configuration, and vice versa, during the kinematics of folding and unfolding the jib, and the control/command system is configured to control the configuration change operations as a function of the actual inclinations of the jib element or of several jib elements in several intermediate configurations, for example in all intermediate configurations, or between successive intermediate configurations.
The folding and unfolding of the jib generally takes place in the form of decompositions of transient movements, with successive transient movements which define intermediate configurations between each transient movement. Controlling all or part of these intermediate configurations allows efficient monitoring of the kinematics of folding and unfolding the jib. It should therefore be noted that an intermediate configuration is a static configuration (and not a dynamic configuration) which is the result of a previous transient movement (or a previous displacement) of at least one mast element or jib element, and which precedes a posterior transient movement (or a posterior displacement) of at least one other mast element or jib element.
Advantageously, the crane comprises a memory storing theoretical inclinations of the jib element or of the several jib elements with respect to the reference axis, and the control/command system is connected to said memory and is configured to control the configuration change operations by comparing the theoretical inclinations with the actual inclinations during the kinematics of folding and unfolding the jib.
These theoretical inclinations thus define a modeling of the kinematics of folding and unfolding the jib, which will allow effectively checking the consistency of the transient movements and the positions of the jib elements in the intermediate configurations, and thus validate these intermediate configurations as well as the consistency of the transient movements during the displacements between two intermediate configurations.
In a particular embodiment, the memory stores theoretical inclinations of the jib element or of the several jib elements in several intermediate configurations, for example in all intermediate configurations, and the control/command system is configured to control the configuration change operations by comparing the theoretical inclinations with the actual inclinations in the several intermediate configurations during the kinematics of folding and unfolding the jib.
According to one possibility, the memory stores theoretical inclinations of the jib element or of the several jib elements in the transport configuration and in the work configuration, and the control/command system is configured to control the configuration change operations also comparing the theoretical inclinations with the actual inclinations in the transport configuration and in the work configuration during the kinematics of folding and unfolding the jib.
Advantageously, the control/command system is configured to authorize the switch from a current configuration into a posterior configuration, such as for example from a current intermediate configuration to a posterior intermediate configuration, on condition that the actual inclination of the jib element or the actual inclinations of the several jib elements in the current configuration correspond to the theoretical inclination of the jib element or the theoretical inclinations of the several jib elements in the current configuration.
In other words, during the configuration change operations, which move elements from one configuration to another configuration until reaching the transport configuration or the work configuration, the control/command system allows switching from one configuration (current configuration) into another configuration (posterior configuration) only on the condition that the actual inclination(s) correspond(s) to the corresponding inclination(s) in the current configuration. As long as the condition is not met, it is not possible to continue the configuration change beyond the current configuration.
In the context of the invention, a current configuration can be the transport configuration, the work configuration or any of the intermediate configurations. Similarly, a posterior configuration can be the transport configuration, the work configuration, or any of the intermediate configurations.
In an advantageous embodiment, the control/command system is configured to detect a folding/unfolding non-compliance if an actual inclination of the jib element or of one of the several jib elements, called non-compliant jib element, does not correspond to the theoretical inclination of said non-compliant jib element during the kinematics of folding and unfolding the jib.
According to one feature, the control/command system is configured to detect folding/unfolding non-compliance if the actual inclination of the non-compliant jib element does not correspond to the theoretical inclination of said non-compliant jib element in at least one of the intermediate configurations.
According to another feature, the control/command system is configured to stop the motor-driven folding/unfolding system in response to a detection of a folding/unfolding non-compliance.
According to one variant, the crane comprises an alarm system capable of emitting an alarm signal and connected to the control/command system, said control/command system being configured to command the emission of the alarm signal by the alarm system in response to a detection of a folding/unfolding non-compliance.
The invention also relates to a control method for controlling configuration change operations of a self-erecting crane comprising a mast supporting a jib, said jib being a foldable jib comprising jib elements articulated together, the configuration change operations implementing kinematics of folding and unfolding the jib and causing said self-erecting crane to switch from a transport configuration in which the mast and the jib are joined together or side-by-side, into a work configuration in which the mast and the jib are deployed, or vice versa.
The control method implements the following steps:
In a particular embodiment, theoretical inclinations of the jib element or of the several jib elements with respect to the reference axis are stored in a memory, and the control of the configuration change operations comprises a comparison of the theoretical inclinations with the actual inclinations during the kinematics of folding and unfolding the jib.
According to one possibility, a folding/unfolding non-compliance is detected if an actual inclination of the jib element or of one of the several jib elements, called non-compliant jib element, does not correspond to the theoretical inclination of said non-compliant jib element during the kinematics of folding and unfolding the jib.
According to another possibility, the jib occupies successive intermediate configurations between the transport configuration and the work configuration, and vice versa, during the kinematics of folding and unfolding the jib, and the folding/unfolding non-compliance is detected if the actual inclination of the non-compliant jib element does not correspond to the theoretical inclination of said non-compliant jib element in at least one of the intermediate configurations.
According to one feature, the configuration change operation is stopped in response to a detection of a folding/unfolding non-compliance.
According to another feature, an alarm signal is emitted in response to a detection of a folding/unfolding non-compliance.
Other features and advantages of the present invention will appear on reading the detailed description hereinafter, of a non-limiting example of implementation, made with reference to the appended figures in which:
Referring to
The crane 1 is configurable between:
In the rest of the description, only the work configuration with the horizontal jib is described.
It should be noted that, in the context of a jib 3 with three jib elements 31, 32, 33, it is possible to have an intermediate work configuration CWI (shown in
The crane 1 is thus equipped with a motor-driven folding/unfolding system 4 which is coupled to the mast 2 and to the jib 3 to act on the mast 2 and on the jib 3 to fold and unfold the crane 1 and thus make it switch from the work configuration into the transport configuration, and vice versa. In other words, this motor-driven folding/unfolding system 4 allows performing configuration change operations implementing kinematics of folding and unfolding the jib 3, and where necessary of deploying and retracting the mast 2.
This motor-driven folding/unfolding system may comprise, in the example illustrated in
The crane 1 further comprises a control/command system 5 connected to the motor-driven folding/unfolding system 4, and more specifically to the electric motors 41, 44, to drive it and control the configuration change operations. Thus, an operator can command the configuration change operations by means of a driving interface (not illustrated), such as for example a wired or wireless manual command, which is connected to the control/command system 5.
According to the invention, the crane 1 comprises at least one inclinometer mounted on one of the jib elements 32, 32, 33 to measure actual inclinations of this jib element with respect to a reference axis, such as a horizontal axis or a vertical axis. In the illustrated example, the crane 1 comprises two inclinometers, namely a first inclinometer 61 and a second inclinometer 62, mounted on the first jib element 31 and on the second jib element 32 respectively, to measure the actual inclinations of this first jib element 31 and of this second jib element 32 respectively.
Referring to
Each of the two inclinometers 61, 62 can be an inclinometer with absolute angular measurement with respect to the vertical or to the horizontal, depending on the model. The inclinometers 61, 62 may be sensors of reduced size which are directly mounted in a protected location of the structure of each jib element 31, 32.
The control/command system 5 is connected to the two inclinometers 61, 62 and can thus drive the motor-driven folding/unfolding system 4 and control the configuration change operations according to the actual inclinations of the first jib element 31 and of the second jib element 32 during the kinematics of folding and unfolding the jib 3.
Referring to
In these three intermediate configurations CI1, CI2, CI3, the mast 2 and all of the jib elements 31, 32, 33 have the same inclination, so that each of the two inclinometers 61, 62 allows monitoring in real time the inclinations of the mast 2 and of the jib elements 31, 32, 33.
Afterwards, once the third intermediate configuration CI3 has been reached (when starting from the transport configuration CT towards the work configuration CW), are planned:
In the kinematics of
As regards the first phase of unfolding the jib 3, its successive intermediate configurations are:
In the kinematics of
In the kinematics of
The two inclinometers 61, 62 allow monitoring in real time the inclinations of the 25 three jib elements 31, 32, 33, insofar as the second jib element 32 and the third jib element 33 have the same relative inclination with respect to the first jib element 31 (according to the first opening angle A3).
Afterwards, once the seventh intermediate configuration CI7 or the eighth intermediate configuration CI8 has been reached (when starting from the transport 30 configuration CT in the direction of the work configuration CW), a second phase of unfolding the jib 3 is planned, in which the second jib element 32 is unfolded.
As regards the second phase of unfolding the jib 3, its successive intermediate configurations are:
This second opening angle A10 can be a mechanically fixed angle, to enable the unfolding of the third jib element 33 to be initiated.
The two inclinometers 61, 62 allow monitoring in real time the inclinations at least of the first jib element 31 and of the second jib element 32, or even also of the third jib element 33 considering that the second opening angle A10 is fixed or imposed mechanically in the intermediate configurations CI10 and CWI, so that its inclination is deduced from that of the second jib element 32. It is also possible to provide a third inclinometer on the third jib element 33 to monitor its inclination in real time.
Finally, once the intermediate work configuration CWI has been reached (when starting from the transport configuration CT in the direction of the work configuration CW), a third phase of unfolding the jib 3 is provided, in which the third jib element 33 is unfolded. As regards the third phase of unfolding the jib 3, a twelfth intermediate configuration CI12 is provided in which the first jib element 31 and the second jib element 32 are horizontal, and the third jib element 33 is moved away from the second jib element 32 at an inclination angle larger than or equal to 90 degrees, before reaching the work configuration CW in which the three jib elements 31, 32, 33 are all horizontal.
The control/command system 5 can thus be configured to control the configuration change operations according to the actual inclinations of the jib elements 31, 32 in all or part of the intermediate configurations or between successive intermediate configurations.
As shown in
The control/command system 5 is connected to this memory 50 and is configured to control the configuration change operations by comparing the theoretical inclinations with the actual inclinations during the kinematics of folding and unfolding the jib 3. Thus, the control/command system 5 can validate each intermediate configuration before continuing the kinematics of folding or unfolding, based on the actual inclinations measured by the inclinometers 61, 62.
In practice, the control/command system 5 is configured to authorize the switch from a current configuration into a posterior configuration, on the condition that the actual inclinations of the jib elements 31, 32 in the current configuration correspond to the respective theoretical inclinations of the jib elements 31, 32 in this current configuration.
Also, the control/command system 5 is configured to detect a folding/unfolding non-compliance if an actual inclination of one of the jib elements 31, 32, called non-compliant jib element, does not correspond to the theoretical inclination of this non-compliant jib element during the kinematics of folding and unfolding the jib 3. Thus, the control/command system 5 assesses that there is a folding/unfolding non-compliance if, in a current configuration, the actual inclinations of at least one of the jib elements 31, 32 does not correspond to the theoretical inclination of this jib element in this current configuration. In this case, and as previously described, the control/command system 5 does not authorize switch into the posterior configuration, and it stops the motor-driven folding/unfolding system 4 in response to the detection of such folding/unfolding non-compliance.
Thus, the control/command system 5 checks the consistency of the movements and of the position of the jib elements 31, 32 during the transient mounting phases (in other words in the intermediate configurations) and thus validates the intermediate configurations during these transient phases as well as the consistency of the movements during the displacements of the jib elements 31, 32 between two intermediate configurations.
| Number | Date | Country | Kind |
|---|---|---|---|
| 21/05978 | Jun 2021 | FR | national |
