Working machine comprising an electrical energy storage unit and two chargers for recharging it

Abstract

The invention relates to a working machine (1) comprising a power supply system (20), the power supply system (20) comprising an electrical energy storage unit (29), two input sockets (31, 32), and two chargers (41, 42) for recharging the electrical energy storage unit (29) from the input sockets (31, 32). The input sockets (31, 32) are respectively intended to be connected to a single-phase power supply network (400) and to a voltage source, in particular a generator (74; 740) of an on-board generator set (70). A control unit (50) is configured to, in response to a detection of the powered state of the first charger (41) and to a concomitant detection of the powered state of the second charger (42), deactivate at least one of the first charger (41) and the second charger (42). Figure for abstract: Fig. 2

Description

Title of the invention: Working machine comprising an electrical energy storage unit and two chargers for recharging it Technical field

[0001] The invention relates to the field of work machines and more particularly concerns electric work machines, that is to say those which are equipped with an electrical energy storage unit to supply energy to the work machine.

[0002] The invention relates more particularly to electric working machines comprising a propulsion structure for enabling the movement of the working machine and a load handling apparatus and in which the electrical energy storage unit is configured to supply energy to the propulsion structure and to the load handling apparatus. Technological background

[0003] Work machines of the aforementioned type are known in the state of the art which are further equipped with an on-board charger for recharging the electrical energy storage unit.

[0004] In practice, the on-board charger may be powered by an on-board generator of the machine, and the electrical energy storage unit comprises a battery, for example of the lead-acid type. The battery should be protected from damage which could be caused by incorrect recharging. Summary

[0005] One idea underlying the invention is to provide a working machine offering flexibility of use from the point of view of recharging the electrical energy storage unit. Another idea underlying the invention is to protect the electrical energy storage unit against damage.

[0006] According to one embodiment, the invention provides a working machine comprising - a chassis; - a propulsion structure in contact with the ground to allow movement of the work machine; - a load handling device mounted mobile relative to the chassis; and - an electrical power system for supplying electrical energy to the propulsion structure and the load handling apparatus, wherein the electrical power system comprises: - an electrical energy storage unit; - a first input socket intended to be connected to a single-phase electrical supply network, and a first charger configured to recharge the electrical energy storage unit from the first input socket; - a second input socket intended to be connected to a voltage source, and a second charger configured to recharge the electrical energy storage unit from the second input socket; and - a control unit; wherein the control unit is connected to the first charger and the second charger, and the control unit is configured to detect a powered state of the first charger and the second charger, wherein the control unit is configured to, in response to a detection of the powered state of the first charger and a concomitant detection of the powered state of the second charger, deactivate at least one of the first charger and the second charger.

[0007] Thanks to these features, an operator of the work machine can recharge the electrical energy storage unit by connecting it to the single-phase electrical supply network and by connecting it to another voltage source, which offers flexibility of use that is very appreciable from the operator's point of view. Furthermore, the deactivation of at least one of the first charger and the second charger prevents simultaneous operation of these which could increase the risk of damage to the electrical energy storage unit.

[0008] According to embodiments, such a working machine may comprise one or more of the following characteristics.

[0009] According to one embodiment, the electrical energy storage unit comprises a lead-acid battery. Preventing simultaneous operation of the first charger and the second charger is particularly preferable in this case, because although lead-acid type batteries are economically and industrially attractive due to their low cost, they are susceptible to premature degradation by incorrect recharging that would result from such simultaneous operation. Nevertheless, the electrical energy storage unit can be implemented in other ways. In particular, according to another embodiment, the electrical energy storage unit comprises a lithium-ion battery.

[0010] The detection of the powered state of the first charger and the second charger by the control unit can be implemented in a large number of ways. According to one embodiment, the first charger comprises a first sensor configured to detect the powered state of the first charger, the second charger comprises a second sensor configured to detect the powered state of the second charger, and the control unit is connected to the first sensor and the second sensor. For example, the first sensor is a current sensor capable of detecting the powered state of the first charger by measuring an electrical current through or at the output of the first charger, and the second sensor is a current sensor capable of detecting the powered state of the second charger by measuring an electrical current through or at the output of the second charger. According to another embodiment, the first charger comprises a first control device connected to the control unit and configured to signal to the control unit the powered state of the first charger, and the second charger comprises a second control device connected to the control unit and configured to signal to the control unit the powered state of the second charger.

[0011] According to one embodiment, the work machine further comprises an on-board display device.

[0012] According to one embodiment, the working machine further comprises an on-board generator set, the on-board generator set comprising a generator forming said voltage source and an output connected to the generator, the output being connected or intended to be connected to the second input socket.

[0013] Thus, the operator of the work machine can recharge the electrical energy storage unit using the on-board generator set, even in the absence of any electrical supply network, which further increases the flexibility of use of the work machine.

[0014] According to one embodiment, the control unit is configured to, in response to detecting the powered state of the first charger and concomitantly detecting the powered state of the second charger, deactivate the second charger.

[0015] In other words, when the first charger and the second charger are powered simultaneously, only the recharging of the electrical energy storage unit by the first charger, and therefore by the single-phase electrical supply network, is permitted by the control unit.

[0016] According to one embodiment, the on-board generator set further comprises a control module connected to the control unit, the control module being configured to signal an operating state of the generator to the control unit, and the control unit is further configured to command the control module to deactivate the generator in response to detection of a deactivation condition.

[0017] Thus, the control unit can deactivate the generator of the on-board generator set when necessary to limit the risk of damage to the electrical energy storage unit or other risk.

[0018] According to one embodiment, the control unit is configured to detect in as a deactivation condition that the operating state of the generator transitioned from an off state to a running state while an energized state of the first charger was detected and / or to detect as a deactivation condition that the energized state of the first charger occurred while an on state of the generator was detected.

[0019] According to one embodiment, the on-board generator set further comprises an additional single-phase output. The additional single-phase output allows the operator of the work machine to supply electricity to an electrical appliance, even in the absence of any electrical supply network.

[0020] According to one embodiment, the control unit is further configured to detect as a deactivation condition that a powered state of the first charger and a powered state of the additional single-phase output are detected concomitantly.

[0021] This makes it possible to prevent the electrical energy storage unit from being recharged by the additional single-phase output, in particular if the additional single-phase output delivers too little power compared to the optimal power for recharging the electrical energy storage unit, thus leading to the latter taking too long to recharge. This is particularly preferable in the case where the electrical energy storage unit comprises one or more lead-acid type batteries. Indeed, lead-acid type batteries cannot generally be recharged for too long a period, for example for more than approximately 12 hours.

[0022] The detection of the powered state of the additional single-phase output by the control unit can be carried out in various ways. According to one embodiment, the additional single-phase output comprises an additional sensor configured to detect a powered state of the additional single-phase output. According to one embodiment in this case, the control module of the on-board generator set is connected to the additional sensor and is configured to detect and report the powered state of the additional output to the control unit. According to another embodiment in this case, the control unit is connected directly to the additional sensor.

[0023] According to one embodiment, the control unit is further configured to deactivate the first charger and / or the second charger in response to the deactivation condition.

[0024] According to one embodiment, the control unit is further configured to send an activation signal of the on-board generator set to the control module in response to the detection of an activation condition.

[0025] According to one embodiment, the power supply system further comprises a user interface device connected to the control unit, the control unit control being configured to receive a user action signal from the user interface device.

[0026] According to one embodiment, the control unit is further configured to detect the user action signal as the activation condition.

[0027] According to one embodiment, the electrical power supply system further comprises a device for evaluating the state of charge configured to determine a value V representative of the state of charge of the electrical energy storage unit.

[0028] According to one embodiment, the control unit is further configured to, in response to detecting the user action signal as the activation condition: - compare the value V to a first threshold Vi and to a second threshold V2, where Vi < V2; - deactivate the second charger when the value V is lower than the first threshold Vi; and / or - deactivate the first charger and optionally the second charger when the value V is higher than the second threshold V2.

[0029] According to one embodiment, the control unit is further configured to subsequently deactivate the second charger when the value V becomes greater than the second threshold V2.

[0030] According to one embodiment, the load handling apparatus comprises a working platform and a lifting mechanism for the working platform, the lifting mechanism being arranged on the chassis.

[0031] According to one embodiment, the electrical power supply system further comprises a third input socket connected to the additional single-phase output, the third input socket being intended to supply equipment of the work platform.

[0032] Thus, the operator of the work machine can supply electricity to equipment on the work platform, such as a power tool, even in the absence of any power supply network.

[0033] According to one embodiment, the user interface device is located on the work platform.

[0034] According to one embodiment, the second input socket is a three-phase input socket intended to be connected to a three-phase voltage source, and the second charger is a three-phase charger.

[0035] This provides additional flexibility of use to the operator, as he can use both a single-phase power supply network and a three-phase power supply network to carry out the recharging of the electrical energy storage unit.

[0036] According to one embodiment, the output of the on-board generator set connected or intended to be connected to the second input socket is a three-phase output.

[0037] According to one embodiment, the electrical power supply system comprises two second input sockets each intended to be connected to a single-phase voltage source, and two second chargers each configured to recharge the electrical energy storage unit from a said second input socket.

[0038] According to one embodiment, the on-board generator set comprises two single-phase outputs, each of the two outputs being connected or intended to be connected to a said second input socket. Brief description of the figures

[0039] The invention will be better understood, and other aims, details, characteristics and advantages thereof will appear more clearly during the following description of several particular embodiments of the invention, given solely for illustrative and non-limiting purposes, with reference to the appended drawings.

[0040] [Fig-1] [Fig.l] is a perspective view of a working machine, of the type people lifting platform.

[0041] [Fig.2] [Fig.2] is a block diagram of the power supply system of the work machine.

[0042] [Fig.3] [Fig.3] is a functional block diagram of the working machine.

[0043] [Fig.4] [Fig.4] is a block diagram similar to [Fig.2], illustrating a case of use of the work machine.

[0044] [Fig.5] [Fig.5] is a block diagram analogous to [Fig.2], illustrating another use case of the working machine.

[0045] [Fig.6] [Fig.6] is a block diagram of the power supply system of the working machine according to an embodiment variant. Description of the embodiments

[0046] With reference to [Fig.l], a work machine 1 is described which, in the embodiment shown, is a lifting platform. Of course, the invention applies to other types of work machines, such as telescopic handlers, masted trucks, excavators, loaders, cranes or others.

[0047] The working machine 1 comprises a chassis 2 as well as a propulsion structure 3 in contact with the ground to allow the working machine 1 to move on the ground.

[0048] In the embodiment shown, the propulsion structure 3 comprises two axles 4, 5, a front axle and a rear axle, which are each mounted on the chassis 2 along a transverse axis and are each equipped with two wheels, one on the left and the other on the right. At least one of the two axles 4, 5 and, preferably, both are motors and are, for this purpose, coupled to an electric motor, not shown in [Fig.l], via a transmission device. In an alternative embodiment, the propulsion structure 3 comprises tracks.

[0049] Furthermore, the working machine 1 comprises a load handling apparatus 6. In [Fig.l], the load handling apparatus 6 comprises a lifting arm 7 pivotally mounted on the frame 2 of the working machine 1 about at least one horizontal axis. In the illustrated embodiment, the lifting arm 7 comprises several parts which are mounted articulated to each other. In other embodiments, the lifting arm 7 is telescopic and comprises at least two parts sliding one inside the other.

[0050] The load handling apparatus 6 comprises at least one jack 8 enabling the lifting arm 7 to pivot relative to the chassis 2. To do this, the jack 8 comprises a first end mounted articulated on the chassis 2 of the working machine 1 and a second end mounted articulated on the lifting arm 7. The lifting arm 7 is thus able to deploy from its folded, storage position, shown in [Fig.l].

[0051] Furthermore, the lifting arm 7 has a distal end which is equipped with an accessory 9 or a modular accessory holder capable of receiving accessories of several types. In the embodiment shown, the accessory 9 is a nacelle basket. However, in other embodiments, the accessory 9 is a work tool, such as a pair of forks, a bucket, a winch, a clamp or others.

[0052] With reference to [Fig.2], the working machine 1 comprises an electrical power supply system 20.

[0053] The electrical power supply system 20 comprises an electrical energy storage unit 29. In the embodiment shown, the electrical energy storage unit 29 supplies an electric motor 11 as well as a drive device 12 of the load handling apparatus 6. The electric motor 11, hereinafter referred to as the propulsion motor 11, belongs to the propulsion structure 3 and is intended to provide propulsion for the working machine 1. To this end, the propulsion motor 11 is coupled by a transmission device, not shown, to one of the two axles 4, 5 or to both. The transmission device may be a mechanical device or a hydraulic device.

[0054] The drive device 12 of the load handling apparatus 6 may be electric and include electric actuators. The drive device 12 may also be electrohydraulic and include a pump driven by an electric motor, one or more hydraulic actuators, such as the cylinder 8 for moving the lifting arm 7, hydraulic distributors, etc.

[0055] The power supply system 20 further comprises a first socket input 31, a second input jack 32, and a third input jack 33.

[0056] The first input socket 31 is intended to be connected to an electrical power supply network 400 (hereinafter referred to as “the sector 400”) delivering a single-phase alternating voltage.

[0057] The second input socket 32 ​​and the third input socket 33 are intended to be connected to a voltage source, here a generator 74 of an on-board generator set 70, described below, of the working machine 1.

[0058] The first input socket 31 is associated with a first charger 4L. The first charger 41 is configured to recharge the electrical energy storage unit 29 from the first input socket 31.

[0059] For this, the first charger 41 converts a voltage delivered to the terminals of the charger 41 into a voltage suitable for recharging the electrical energy storage unit 29. For example, the first charger 41 converts the single-phase alternating voltage delivered by the mains 400 into a direct voltage compatible with correct operation of the electrical energy storage unit 29. Of course, the first charger 41 is configured to be able to operate with one type of single-phase voltage delivered by the mains 400 (for example 230 volts and 50 hertz, typical voltage in Europe) or, alternatively, with several types of single-phase voltage (for example 230 volts and 50 hertz and 120 volts and 60 hertz, typical voltage in North America).

[0060] The DC voltage for recharging the electrical energy storage unit 29 is chosen depending on the construction of the electrical energy storage unit 29. For example, the electrical energy storage unit 29 comprises one or more batteries, for example of the lead-acid type or of the lithium-ion type. In an example where the electrical energy storage unit 29 comprises one or more batteries of the lead-acid type, this DC voltage is chosen to be between 2.0 volts and 2.3 volts across the lead-acid battery.

[0061] Similarly, the second input socket 32 ​​is associated with a second charger 42. Similarly to the first charger 41, the second charger 42 is configured to recharge the electrical energy storage unit 29 from the second input socket 32.

[0062] With reference to [Fig.3], the working machine 1 comprises a control unit 50.

[0063] As shown, the control unit 50 is connected to the first charger 41 and the second charger 42 so as to be able to activate and deactivate them. By "activate" is meant that the charger 41 (respectively 42) changes from a deactivated state in which the charger 41 (respectively 42) does not allow the transmission of electrical power through the charger 41 (respectively 42) to an activated state in which the charger 41 (respectively 42) allows the transmission of electrical power through the charger 41 (respectively 42). The term "deactivate" has the opposite meaning, i.e. the transition from the activated state to the deactivated state.

[0064] The activation and deactivation of the chargers 41, 42 controlled by the control unit 50 can be implemented in a large number of ways, for example by means of an electromechanical relay or by means of a contactor.

[0065] The activation and deactivation of the chargers 41, 42 is implemented such that it is not affected by the powered state thereof. By "powered state" is meant a state in which the charger 41 (respectively 42) is electrically connected to a voltage source via the input socket 31 (respectively 32), the voltage source delivering a voltage across the charger 41 (respectively 42) via the input socket 31 (respectively 32). In other words, when the control unit 50 deactivates the charger 41 (respectively 42), the charger 41 (respectively 42) does not allow the transmission of electrical power through the charger 41 (respectively 42) until the control unit 50 has again activated the charger 41 (respectively 42).

[0066] Furthermore, the control unit 50 is configured to detect the powered state of the chargers 41, 42.

[0067] The detection of the powered state of the chargers 41, 42 by the control unit 50 can be implemented in a large number of ways.

[0068] In the example shown, the charger 41 (respectively 42) comprises a current detection sensor (hereinafter referred to as "sensor") 51 (respectively 52). The sensor 51 (respectively 52) is a current sensor capable of detecting the powered state of the charger 41 (respectively 42) by measuring an electrical intensity through or at the output of the charger 41 (respectively 42). The control unit 50 is connected to the sensor 51 (respectively 52) so that the control unit 50 detects the powered state of the charger 41 (respectively 42) via the sensor 51 (respectively 52). The sensors 51, 52 can be implemented in a large number of ways, for example in the form of an electromagnetic induction sensor (current clamp) or a Hall effect current sensor.

[0069] Alternatively, the charger 41 (respectively 42) incorporates a control device connected to the control unit 50 and configured to signal to the control unit 50 the powered state of the charger 41 (respectively 42).

[0070] Furthermore, the electrical power supply system 20 comprises a state of charge evaluation device 59 which is configured to determine a value V representative of the state of charge of the electrical energy storage unit 29. The state of charge is a relative measure of the quantity of stored energy corresponding to the ratio between the charge of the electrical energy storage unit 29 at a certain moment and its total capacity, originally.

[0071] In the example shown, the state of charge evaluation device 59 is associated with the electrical energy storage unit 29 and the control unit 50 is connected to the state of charge evaluation device 59. Alternatively, the function of the state of charge evaluation device 59 can be implemented by the control unit 50 itself, or by one or more of the aforementioned control devices integrated into the chargers 41, 42.

[0072] The determination of the state of charge can be implemented in a large number of ways.

[0073] According to one embodiment, the state of charge evaluation device 59 comprises a voltage sensor which delivers a measurement of the voltage, in open circuit, at the terminals of the electrical energy storage unit 29. The voltage at the terminals of the electrical energy storage unit 29 varying according to its charge level, such a measurement of the voltage at the terminals of the electrical energy storage unit 29 makes it possible to estimate its state of charge.

[0074] According to another embodiment, the state of charge evaluation device 59 comprises a coulomb counter which measures the current during the charging or discharging of the energy storage unit and integrates it, which makes it possible to determine the quantity of charges injected or withdrawn from the electrical energy storage unit 29 and thus to quantify its state of charge.

[0075] Furthermore, the control unit 50 is connected to a control device 67 of the propulsion structure 3 and to a control device 68 of the load handling apparatus 6. The control device 67 is configured to deliver requests for actuation of the propulsion structure 3 received from a control member (such as an accelerator pedal for example) to a control module of the propulsion structure 3. The control device 68 is configured to deliver requests for actuation of the load handling apparatus 6 received from a control member (such as a joystick for example).

[0076] In the example shown, the control device 67 and the control device 68 are implemented in the form of an electronic control unit, programmable or not. Alternatively, the respective functions of the control device 67 and / or the control device 68 can be implemented by the control unit 50 itself.

[0077] The control unit 50 can be implemented in a large number of ways, for example in the form of an electronic control unit (ECU), programmable or not.

[0078] Still with reference to [Fig. 3], the control unit 50 can further be connected to a display device 99 on board the working machine 1.

[0079] The connections which have just been described between the control unit 50 on the one hand, and on the other hand the chargers 41, 42, the sensors 51, 52, the charge state evaluation device 59, the control devices 67, 68, and the display device 99, can be made in a large number of ways, for example by means of a data bus 1001.

[0080] As mentioned above, the working machine 1 comprises an on-board generator set 70 (hereinafter referred to as "the generator set 70"). With reference to [Fig. 2], the generator set 70 comprises a housing 71 delimiting an interior volume for receiving various elements described below of the generator set 70. In a manner not shown, the working machine 1 has, for example at its chassis 2, a location for receiving the housing 71, and for holding the housing 71 in place. The generator set 70 may be permanently located on the working machine 1 or removable.

[0081] Still with reference to [Fig.2], the generator set 70 comprises an electric generator 74 (hereinafter “the generator 74”) and a mechanical power source 75 for driving the generator 74. In one example, the mechanical power source 75 is an internal combustion engine supplied with fuel by a fuel tank, this fuel tank possibly or not being arranged in the housing 71. In the example shown, the generator 74 is a three-phase alternating voltage generator.

[0082] The generator set 70 further comprises a main output 72 and an additional output 73.

[0083] The main output 72 is configured to be connected to the second input socket 32. The main output 72 is intended to recharge the electrical energy storage unit 29 via the second input socket 32 ​​and the second charger 42 as described above. Thanks to the main output 72, the generator set 70 makes it possible to recharge the electrical energy storage unit 29 even in the absence of the mains 400, and thereby allows operation of the work machine 1 even in the absence of the mains 400. In the example shown, the main output 72 is a three-phase output and the second input socket 32 ​​is a three-phase input socket.

[0084] The additional output 73 is configured to be connected to the third input socket 33 of the electrical power supply system 20. The third input socket 33 is connected to an accessory socket 13, here arranged in the nacelle basket 9. Thanks to the additional output 73, the generator 70 makes it possible to supply electricity to an electrical appliance, for example an electric tool for an operator having to work in the nacelle basket 9, even in the absence of the mains 400. In the example shown, the additional output 73 is a single-phase output and the third input socket 33 is a single-phase input socket. In this case, the accessory socket 13 can deliver without conversion the single-phase alternating voltage supplied by the additional output 73 via the third input socket 33.

[0085] Referring now to [Fig.2] and [Fig.3], the generator set 70 comprises a control module 78 configured to detect a powered state of the main output 72 and the additional output 73.

[0086] The detection of the powered state of the main output 72 and the additional output 73 can be implemented in a large number of ways.

[0087] In the example shown, the generator set 70 comprises sensors 76, 77 similar to the sensors 51, 52 described above and the control module 78 is connected to the sensors 76, 77, so that the control module 78 detects a powered state of the main output 72 (respectively of the additional output 73) via the sensor 76 (respectively via the sensor 77). Like the sensors 51, 52, the sensors 76, 77 can be implemented in a large number of ways, for example in the form of an electromagnetic induction sensor (current clamp) or a Hall effect current sensor.

[0088] Alternatively, the main output 72 (respectively the additional output 73) integrates a control device connected to the control module 78 and configured to signal to the control module 78 the powered state of the main output 72 (respectively of the additional output 73).

[0089] Furthermore, the control module 78 is configured to control the operation of the generator 74, for example by controlling the operation of the thermal engine 75 via an engine control module 75P.

[0090] The control module 78 can be implemented in a large number of ways, for example in the form of an electronic control unit, programmable or not.

[0091] The connection just described between the control module 78 on the one hand, and on the other hand the sensors 76, 77 and the engine control module 75P, can be achieved in a large number of ways, for example by means of a data bus 1007.

[0092] As shown in [Fig. 3], a data connector 1050 is provided (for example on the working machine 1) to enable the data buses 1007 and 1001 to be connected to each other, and thereby to connect the control unit 50 and the control module 78 to each other. According to one embodiment, the data buses 1001, 1007 are each a CAN (Controller Area Network) data bus (registered trademark).

[0093] Thus, the control unit 50 and the control module 78 can communicate with each other via the data buses 1001 and 1007 connected to each other via the data connector 1050. More specifically, the control module 78 is configured to signal an operating state of the generator 74 to the control unit 50, and the control unit 50 is configured to control the control module 78 to deactivate the generator 74. Furthermore, the control module 78 is configured to signal to the control unit 50 a powered state of the main output 72 (respectively of the additional output 73).

[0094] As mentioned above, thanks to the second input socket 32 ​​and the second charger 42, an operator of the work machine 1 can recharge the electrical energy storage unit 29 using the generator set 70, even in the absence of the mains 400. Furthermore, thanks to the first input socket 31 and the first charger 41, the operator can recharge the electrical energy storage unit 29 using the mains voltage 400 when the latter is available. The work machine 1 therefore offers a flexibility of use which is very appreciable from the operator's point of view.

[0095] However, the presence of two chargers 41, 42 may lead the operator to attempt to accelerate the recharging of the electrical energy storage unit 29 by operating the two chargers 41, 42 simultaneously. Such simultaneous operation may increase the risk of damage to the electrical energy storage unit 29. For example, it may lead to an overvoltage of the electrical energy storage unit 29, which may cause damage to the electrical energy storage unit 29, or even a fire and / or an explosion of the lead-acid or lithium-ion type batteries. Furthermore, although lead-acid type batteries are advantageous from an economic and industrial point of view due to their low cost, they are likely to be degraded prematurely by incorrect recharging which would result from such simultaneous operation.

[0096] Various features of the power supply system 20 and / or the generator set 70 are described below, which aim to prevent simultaneous operation of the two chargers 41, 42 and thereby tend to reduce damage to the storage unit 29.

[0097] As mentioned above, the control unit 50 detects the powered state of the chargers 41, 42, and the control unit 50 is adapted to activate and deactivate the chargers 41, 42. Furthermore, the control unit 50 controls the activation and deactivation of the chargers 41, 42 according to the respective powered states of the chargers 41, 42. Generally, when the control unit 50 detects that the chargers 41, 42 are simultaneously in a powered state, the control unit 50 deactivates the first charger 41 and / or the second charger 42. Thus, simultaneous operation of the chargers 41, 42 is prevented. Furthermore, the control unit 50 can independently keep each of the chargers 41, 42 deactivated.

[0098] In [Fig.2], the reference Cl designates an electrical connection between the first input socket 31 and the mains 400, the reference C2 designates an electrical connection between the second input socket 32 ​​and the main output 72, and the reference C3 designates an electrical connection between the third input socket 33 and the additional output 73. In [Fig.3], the reference DA designates a data connection between the buses 1001, 1007 made by means of the connector 1050.

[0099] In the following description of the operating case of the working machine 1, it is assumed that the data connection DA is made, and that the mains 400 delivers the expected single-phase alternating voltage. On the other hand, the generator 74 can be in operation or stopped; the electrical energy storage unit 29 can be fully charged or not fully charged; and each of the electrical connections C1, C2, C3 can either be made or not be made.

[0100] Case A

[0101] The electrical connections C2 and C3 are made, the electrical connection C1 is not made, the chargers 41, 42 are activated, and the generator 74 is in operation.

[0102] Since the generator 74 is in operation and the electrical connection C2 is made, the control unit 50 detects by means of the second sensor 52 that the second charger 42 is in the powered state. When the operator makes the electrical connection C1, the control unit 50 detects that the first charger 41 changes from the unpowered state to the powered state, and therefore detects that the first charger 41 and the second 42 are in the powered state concomitantly. In response, the control unit 50 deactivates the second charger 42, but the control unit 50 does not deactivate the first charger 41, i.e. the control unit 50 keeps the first charger 4L activated. Thus, only the recharging of the electrical energy storage unit 29 by the first charger 41, and therefore by the mains 400, is permitted by the control unit 50.If the control unit 50 further detects that the generator 74 is in operation, the control unit 50 commands the control module 78 to deactivate the generator 74.

[0103] Preferably, the control unit 50 further activates a “machine off” operating mode in which the operation of the propulsion structure 3 and the load handling apparatus 6 are stopped. In one example, the control unit 50 activates a stop signal on the data bus 1001, and the control devices 67, 68 cease to issue actuation requests until the stop signal is deactivated. Thus, the safety of the working machine 1 is increased, since the operator is prevented from accidentally pulling out the electric cable making the electrical connection C1 when actuating the propulsion structure 3 or the load handling apparatus 6. The control unit 50 may further display on the display device 99 an indication that the “machine off” operating mode is activated.

[0104] Returning to [Fig. 3], the working machine 1 comprises a user interface device 69 connected to the control unit 50 via the bus 1001. The user interface device 69 is, for example, arranged in the nacelle basket 9.

[0105] The user interface device 69 is provided to allow the operator to control the starting of the generator 74. For this, in response to a user action (such as pressing a button or switching a switch of the user interface device 69), the user interface device 69 emits a user action signal. The control unit 50 is configured to receive the user action signal and to control the generator 74 and / or the charger 41 and / or the charger 42 in response to the user action signal.

[0106] Variant of case A

[0107] The electrical connections C1, C2 and C3 are made, the chargers 41, 42 are activated, and the generator 74 is not in operation.

[0108] Since the electrical connection C1 is made, the control unit 50 detects by means of the first sensor 51 that the first charger 41 is in the powered state. When the operator commands the start of the generator 74 by means of the user interface device 69, the control unit 50 receives the user action signal. In response, the control unit 50 commands the control module 78 to start the generator 74. Thus, the control unit 50 detects that the generator 74 is in operation. However, the control unit 50 further detects that the first charger 41 is in the powered state. In response, the control unit 50 commands the control module 78 to deactivate the generator 74 and keeps the first charger 41 activated.

[0109] Case B

[0110] The electrical connections C2 and C3 are made, the electrical connection C1 is not made, and the chargers 41, 42 are activated.

[0111] When the operator commands the generator 74 to start using the user interface device 69, the control unit 50 receives the user action signal. In response, the control unit 50 commands the control module 78 to start the generator 74. Thus, the operator can use the accessory socket 13 to supply electricity to a power tool as described above.

[0112] Furthermore, the control unit 50 compares the value V transmitted by the state of charge evaluation device 59 to a first threshold Vi and to a second threshold V2. The second threshold V2 is chosen to be lower than a value representing a state of charge of the electrical energy storage unit 29 lower than 100% of its total capacity. For example, V2 = 90% of said total capacity. The first threshold Vi is strictly lower than the second threshold V2, in other words Vi < V2.

[0113] If V > V2, then the storage unit of the electrical unit 29 is sufficiently charged and it is appropriate to prevent the recharging of the electrical energy storage unit 29 by the sector 400; consequently, the control unit 50 deactivates the first charger 41. Optionally, the control unit 50 can also deactivate the second charger 42, if it is desired that the generator 74 is not used to recharge the storage unit of the electrical unit 29 while the latter is already sufficiently charged.

[0114] If Vi < V < V2, then it is appropriate to allow the recharging of the electrical energy storage unit 29, by the generator 74 which has been started or by the sector 400; consequently, the control unit 50 keeps the second charger 42 and the first charger 41 activated. Optionally, the control unit 50 can subsequently deactivate the second charger 42 when V becomes such that V > V2, if it is desired that the generator 74 is not used to recharge the storage unit of the electrical unit 29 while the latter is already sufficiently charged.

[0115] If V < Vj, then it is appropriate that the generator 74 is not used to recharge the storage unit of the electrical unit 29 and that the storage unit of the electrical unit 29 can only be recharged by the mains 400; consequently, the control unit 50 deactivates the second charger 42 and keeps the first charger 41 activated. The control unit 50 can further display an alert on the display device 99. The alert displayed on the display device 99 can then indicate to the operator that the electrical energy storage unit 29 must be recharged

[0116] The value of Vj can be chosen according to various parameters, in particular according to characteristics of the electrical energy storage unit 29 and / or the intended use of the working machine 1. For example, Vi = 50% of the total capacity of the electrical energy storage unit 29.

[0117] The first threshold Vi and / or the second threshold V2 may be a fixed value stored in memory by the control unit 50. Alternatively, the first threshold Vi and / or the second threshold V2 may be recalculated periodically by the control unit 50 according to a defined program, for example as a function of the characteristics and / or an operating duration of the electrical energy storage unit 29.

[0118] As mentioned above, the main output 72 is a three-phase output and the second input socket 32 ​​is a three-phase input socket. This provides additional flexibility of use to the operator. Indeed, as shown in [Fig. 4], the operator can then make an electrical connection CT between the second charger 32 and an electrical supply network 401 delivering a three-phase alternating voltage (hereinafter referred to as "the three-phase mains 401") if the latter is available. However, it is appropriate that the electrical energy storage unit 29 cannot be recharged simultaneously by the mains 400 (not shown in [Fig. 4]) and by the three-phase mains 401.

[0119] CasC

[0120] The electrical connection C3 is made, the electrical connections C1 and C2 (not shown in [Fig.4]) are not made, and the chargers 41, 42 are activated.

[0121] Since the connection C2 is not made, the main output 72 is not in the powered state. When the operator makes the electrical connection CT, the control unit 50 detects that the second charger 42 is changing from the unpowered state to the powered state, and detects that the main output 72 is still in the unpowered state. In response, the control unit 50 deactivates the first charger 41, but the control unit 50 does not deactivate the second charger 42, i.e., the control unit 50 keeps the second charger 42 activated. Thus, only the recharging of the electrical energy storage unit 29 by the second charger 42 is permitted by the control unit 50. If the control unit 50 further detects that the generator 74 is in operation, the control unit 50 commands the control module 78 to deactivate the generator 74.

[0122] Preferably, the control unit 50 further activates the “machine off” operating mode described above. Thus, the operator is prevented from accidentally tearing off the three-phase electrical cable making the electrical connection CT when actuating the propulsion structure 3 or the load handling apparatus 6. The control unit 50 can further display on the display device 99 an indication that the “machine off” operating mode is activated.

[0123] As mentioned above, the additional output 73 is a single-phase output and the third input socket 33 is a single-phase input socket, which allows the operator to supply electricity to a tool. However, it may be preferable to prevent the electrical energy storage unit 29 from being recharged by the additional output 73. This is particularly the case if the additional output 73 delivers too little power compared to the optimal power for recharging the electrical energy storage unit 29, thus leading to the latter taking too long to recharge. This is particularly preferable in the case where the electrical energy storage unit 29 comprises one or more lead-acid type batteries. Indeed, lead-acid type batteries generally cannot be recharged for too long a period, for example for more than approximately 12 hours.

[0124] CasD

[0125] The electrical connections C1 and C3 (not shown in [Fig.5]) are not made, the chargers 41, 42 are activated, and the generator 74 is in operation.

[0126] Since the electrical connection C1 is not made, the first charger 41 is not in the powered state. When, for the purpose of recharging the electrical energy storage unit 29, the operator makes an electrical connection CM between the output additional 73 and the first input jack 31, the control unit 50 detects that the first charger 41 transitions from the unpowered state to the powered state, and detects that the additional output 73 is in the powered state while the generator 74 is operating. In response, the control unit 50 commands the control module 78 to deactivate the generator 74; preferably, the control unit 50 commands the control module 78 to deactivate the generator 74 and deactivates the first charger 41. The control unit 50 may further display on the display device 99 an indication that the CM electrical connection is incorrect. Thus, the operator may be alerted that the CM electrical connection is incorrect and to undo the CM electrical connection.Even more preferably, the control unit 50 further deactivates the second charger 42 and / or further activates the "machine off" operating mode described above, and optionally displays on the display device 99 an indication that the "machine off" operating mode is activated.

[0127] CaseE

[0128] When the operator makes the CM electrical connection and then commands the generator 74 to start, the control unit 50 detects that the first charger 41 changes from the unpowered state to the powered state and that the additional output 73 changes from the unpowered state to the powered state. In response, the control unit 50 executes the same commands as in case D. Thus, the operator can be alerted that the CM electrical connection is incorrect and that he must undo the CM electrical connection.

[0129] In cases D and E described above, the control unit 50 detects the powered state of the additional output 73 by means of the sensor 77. Alternatively, the sensor 77 may be omitted. In this case, the control unit 50 commands the control module 78 to deactivate the generator 74 (and preferably deactivates the first charger 41, and more preferably still deactivates the second charger 42 and / or further activates the “machine off” operating mode described above) when the control unit 51 detects by means of the first sensor 51 that the first charger 41 changes from the unpowered state to the powered state.

[0130] So far, only operating cases where the DA data connection is performed have been described. However, the control unit 50 can prevent the simultaneous operation of the first charger 41 and the second charger 42 as described above even if the DA data connection is not performed.

[0131] In a variant, the sensor 76 and / or the sensor 77 may be connected directly to the control unit 50 (for example via the bus 1001) instead of being connected indirectly to the control unit 50 via the bus 1007 and the connector 1050. Furthermore, in this case, the sensor 76 may be connected in series with the second sensor 52. Thus, returning to case C described above with reference to [Fig.4], the control unit control 50 can detect by means of the sensor 76 that the main output 72 has not changed from the unpowered state to the powered state even if the data connection DA is not made.

[0132] [Fig. 6] represents the electrical power supply system 20 of an alternative embodiment of the working machine 1. In this figure, the elements identical to those described previously bear identical references and are not described again.

[0133] This embodiment differs from the previous one in that the three-phase main output 72 of the generator set 70 is replaced by two single-phase main outputs 72A, 72B. Correspondingly, the input socket 32, the charger 42, the sensor 52 and the sensor 76 are replaced respectively by two input sockets 32A, 32B, two chargers 42A, 42B, two sensors 52A, 52B, and two sensors 76A, 76B. The generator set 70 thus has three single-phase outputs: the main outputs 72A, 72B and the additional output 73. The main outputs 72A, 72B and the additional output 73 are powered by a single-phase alternating voltage generator 740.

[0134] The operation of the working machine 1 according to this embodiment variant is identical to what has been described previously, except that the simultaneous detection by the sensor 52 (respectively 76) is replaced by the simultaneous detection by the sensors 52A, 52B (respectively 76A, 76B), and that the deactivation of the charger 42 is replaced by the simultaneous deactivation of the chargers 42A, 42B. This operation is therefore not detailed again.

[0135] Example of sizing: - admissible input power of the first charger 41: 3 kW; - admissible power at the input of the second charger 42 (or at the input of the chargers 42A, 42B considered together): greater than or equal to 5 kW, in particular between 5 kW and 7 kW; - admissible power at the input of the third input socket 33: less than or equal to 1.5 kW.

[0136] Although the invention has been described in connection with several particular embodiments, it is quite obvious that it is in no way limited thereto and that it includes all the technical equivalents of the means described as well as their combinations if these fall within the scope of the invention.

[0137] The use of the verb “comprise”, “comprise” or “include” and its conjugated forms does not exclude the presence of other elements or other steps than those stated in a claim.

[0138] In the claims, any reference sign in parentheses cannot be interpreted as a limitation of the claim.

Claims

Claims

1. A working machine (1) comprising: - a chassis (2); - a propulsion structure (3) in contact with the ground to allow movement of the working machine (1); - a load handling apparatus (6) mounted movably relative to the chassis (2); and - an electrical power supply system (20) for supplying electrical energy to the propulsion structure (3) and to the load handling apparatus (6), wherein the electrical power supply system (20) comprises: - an electrical energy storage unit (29); - a first input socket (31) intended to be connected to a single-phase electrical power supply network (400), and a first charger (41) configured to recharge the electrical energy storage unit (29) from the first input socket (31); - a second input socket (32; 32A, 32B) intended to be connected to a voltage source, and a second charger (42;42A, 42B) configured to recharge the electrical energy storage unit (29) from the second input socket (32; 32A, 32B); and - a control unit (50); wherein the control unit (50) is connected to the first charger (41) and the second charger (42; 42A, 42B), and the control unit (50) is configured to detect a powered state of the first charger (41) and the second charger (42; 42A, 42B), wherein the control unit (50) is configured to, in response to a detection of the powered state of the first charger (41) and a concomitant detection of the powered state of the second charger (42; 42A, 42B), deactivate at least one of the first charger (41) and the second charger (42; 42A, 42B).;

2. A working machine (1) according to claim 1, further comprising an on-board generator set (70), the on-board generator set (70) comprising a generator (74; 740) forming said voltage source and an output (72; 72A, 72B) connected to the generator (74; 740), the output (72; 72A, 72B) being connected to the second input socket (32; 32A, 32B).

3. A working machine (1) according to claim 2, wherein the control unit (50) is configured to, in response to detecting the state powered from the first charger (41) and upon concomitant detection of the powered state of the second charger (42; 42A, 42B), deactivate the second charger (42; 42A, 42B).

4. A work machine (1) according to any one of claims 2 to 3, wherein the on-board generator set (70) further comprises a control module (78) connected to the control unit (50), the control module (78) being configured to signal an operating state of the generator (74; 740) to the control unit (50), and wherein the control unit (50) is further configured to command the control module (78) to deactivate the generator (74; 740) in response to detection of a deactivation condition.

5. The working machine (1) of claim 4, wherein the control unit (50) is configured to detect as a deactivation condition that the operating state of the generator (74; 740) has changed from an off state to an on state while a powered state of the first charger (41) was detected and / or to detect as a deactivation condition that the powered state of the first charger (41) has occurred while a running state of the generator (74; 740) was detected.

6. A working machine (1) according to any one of claims 4 to 5, wherein the on-board generator set (70) further comprises an additional single-phase output (73), and wherein the control unit (50) is further configured to detect as a deactivation condition that a powered state of the first charger (41) and a powered state of the additional single-phase output (73) are concomitantly detected.

7. A working machine (1) according to any one of claims 5 to 6, wherein the control unit (50) is further configured to deactivate the first charger (41) and / or the second charger (42) in response to the deactivation condition.

8. A working machine (1) according to any one of claims 4 to 7, wherein the control unit (50) is further configured to send an activation signal of the on-board generator set (70) to the control module (78) in response to the detection of an activation condition.

9. A working machine (1) according to claim 8, wherein the power supply system (20) further comprises a user interface device (69) connected to the control unit (50), the unit control unit (50) being configured to receive a user action signal from the user interface device (69), and wherein the control unit (50) is further configured to detect the user action signal as the activation condition.

10. Working machine (1) according to claim 9, wherein the electrical power system (20) further comprises a state of charge evaluation device (59) configured to determine a value V representative of the state of charge of the electrical energy storage unit (29), and the control unit (50) is further configured to, in response to the detection of the user action signal as the activation condition: - compare the value V to a first threshold Vi and a second threshold V2, where Vi < V2; - deactivate the second charger (42; 42A, 42B) when the value V is lower than the first threshold Vi; and / or - deactivate the first charger (41) and optionally the second charger (42; 42A, 42B) when the value V is higher than the second threshold V2.

11. A working machine (1) according to any one of claims 9 to 10 taken in combination with claim 6, wherein the load handling apparatus (6) comprises a working platform (9) and a lifting mechanism (7, 8) of the working platform (9), the lifting mechanism (7, 8) being arranged on the chassis, and the power supply system (20) further comprises a third input socket (33) connected to the additional single-phase output (73), the third input socket (33) being intended to power equipment of the working platform (9), and the user interface device (69) being located on the working platform (9).

12. A working machine (1) according to any one of claims 1 to 11, wherein the second input socket (32) is a three-phase input socket for connection to a three-phase voltage source, and the second charger (42) is a three-phase charger.

13. A working machine (1) according to claim 12 taken in combination with claim 2, wherein the output (72) of the generator set (70) is a three-phase output.

14. A working machine (1) according to any one of claims 1 to 11, wherein the power supply system (20) comprises two second input sockets (32A, 32B) each intended to be connected to a single-phase voltage source, and two second chargers (42A, 42B) each configured to recharge the electrical energy storage unit (29) from a said second input socket (32A, 32B).

15. A working machine (1) according to any one of claims 1 to 14, wherein the electrical energy storage unit (29) comprises a lead-acid battery.

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