Electric assistance system for rail lorry for transporting materials

Abstract

An electric assistance system (10) for equipping a rail lorry (1) for transporting material on rails, the lorry (1) comprising a platform (2) mounted on rail wheels (3) and a push bar (4) configured so that, when a pushing force is exerted by a user on the push bar (4), the lorry (1) moves, the electric assistance system (10) comprising an electric battery (11), an electric traction motor (12) powered by the battery (11), a drive shaft (13) configured to be driven in rotation by the motor (12) and equipped with a drive element (14) configured to drive in rotation one of said wheels (3) when mounted on the lorry (1), a control system (15) for the motor (12), configured to, when the electric assistance system (10) is mounted on the lorry (1), control the power delivered by the motor (12) according to the pushing force of the user acting on the push bar (4),such that when the thrust force is zero or less than a predetermined threshold value, the motor (12) is at rest, and when the thrust force is non-zero and greater than or equal to a predetermined threshold value, the motor (12) drives the drive shaft (13) with power delivered proportional to a speed and / or acceleration controlled by the user. Abstract figure: Figure 1,

Description

Title of the invention: Electric assistance system for a railway lorry for transporting equipment technical field

[0001] This disclosure falls within the field of railway lorries. In particular, it relates to an electric assistance system for a railway lorry for transporting materials, a railway lorry for transporting materials equipped with such an electric assistance system, and a method for driving such a lorry. Prior art

[0002] In the context of handling equipment, for example thermal and / or electric tools, consumables, necessary for carrying out work on railway construction sites, foot crew members use light handling trolleys called "lorry" for transporting the equipment.

[0003] A lorry is a cart comprising a platform mounted on railway wheels that is used to move heavy or bulky loads on railway tracks. It is relatively light in itself, for example about 40 kg empty, but allows the transport of heavy loads, such as a payload of 750 kg for example, with loads going up to 1,000 kg.

[0004] The lorries thus make it possible to transport equipment and tools between access points to railway rights-of-way and work areas. They are powered by human force over several hundred meters, or even a few kilometers for work sites furthest from garage locations and road access.

[0005] The arduous nature of this task is understandable. In particular, the physical effort required can be significant during pushing and intermittent stops, depending on the load being transported and the track topography, with gradients reaching 3.5% to 4%. Furthermore, there is a risk of injury when pushing the lorry to start with heavy loads. Consequently, musculoskeletal disorders can develop among operators performing this daily task.

[0006] There is therefore a need to improve ergonomics and working conditions in this area. Summary

[0007] This disclosure improves the situation.

[0008] An electric assistance system is proposed for equipping a railway lorry for transporting material on rails, the lorry comprising a platform mounted on railway wheels and a push bar configured so that, when a pushing force is applied is exerted by a user on the push bar, the lorry moves, the electric assistance system comprising: a. an electric battery, b. an electric traction motor powered by the battery, c. a drive shaft configured to be rotated by the motor and equipped with a drive element configured to rotate one of said wheels when mounted on the lorry, d. a motor control system, configured to, when the electric assistance system is mounted on the lorry, control the power delivered by the motor according to the pushing force of the user acting on the push bar, such that when the pushing force is zero or less than a predetermined threshold value, the motor is stopped and when the pushing force is non-zero and greater than or equal to the predetermined threshold value, the motor drives the motor shaft with a power delivered proportional to a speed and / or acceleration controlled by the user.

[0009] Thus, the electric assistance system is not intended to make the lorry self-propelled, but simply to assist the user when pushing the lorry. The electric assistance system does not allow for remote control of the lorry. The integration of the electric assistance system on the lorry aims to provide motor torque to the wheel, supplementing the torque transmitted by the human push.

[0010] By "pushing force", we mean a torque transmitted by the human push of the user, which can be measured directly or through a speed of the lorry.

[0011] The predetermined threshold value can be a threshold speed of movement of the lorry. It can be between 0.5 m / s and 2 m / s, for example being equal to 1 m / s.

[0012] The features described in the following paragraphs may optionally be implemented independently of each other or in combination with each other:

[0013] When the lorry has a mechanical parking brake, independent of the push bar, the engine control system can be configured to prevent the engine from driving the drive shaft when the lorry's mechanical parking brake is engaged. Thus, the electric assist system is slaved to the mechanical parking brake, such that when the mechanical parking brake is engaged, the electric assist system is inactive. When the mechanical parking brake is disengaged, the engine control system can then operate as described above to control the power delivered by the engine. The electric assist system may include a brake sensor, configured to detect whether the mechanical parking brake is engaged or not and to send information on the engagement status of the mechanical parking brake. The control system can be configured to receive information about the activation status of the mechanical parking brake from the brake sensor and to control the engine based on such information.

[0014] The electric assistance system may include an electrical box housing the control system and possibly the battery.

[0015] The electric assistance system may include a speed sensor configured to measure the speed of the lorry. The speed sensor may be housed within the electric motor. The speed sensor may be configured to detect a torque corresponding to a pushing force exerted on the push bar. The control system may be configured to receive information, for example at regular intervals or upon polling, from the speed sensor and to control the motor power based on such information.

[0016] The electrical box may be designed to be mounted on a railing mounted on the platform, near the push bar of the lorry. It may include means for attaching it to the railing and for connecting it to the rest of the electric assistance system, in particular to the traction motor.

[0017] The control system may include a programmable logic controller (PLC), a motor control drive, and / or a DC / DC converter. The PLC is preferably programmed to control the power delivered by the motor according to the thrust force.

[0018] The drive element includes, for example, a flanged drive roller configured to drive the railway wheel by friction.

[0019] The battery can have a useful energy capacity of between 750 Wh and 3000 Wh. The battery is advantageously removable and rechargeable via mains power.

[0020] The traction motor is, for example, a motor with a power rating between 100W and 300W.

[0021] In one example, the electric assistance system includes a second electric traction motor and a second drive shaft driven in rotation by the second motor and equipped with a second drive element configured to drive in rotation another of said wheels when mounted on the lorry.

[0022] In the latter case, the electric assistance system may comprise two blocks, namely a first block comprising the traction motor and the drive shaft equipped with the drive element for driving a first railway wheel, and a second block comprising the second traction motor and the second drive shaft equipped with the second drive element for driving a second railway wheel. The control system is advantageously common to both blocks.

[0023] Still in this latter case, each of the two motors can be a traction motor with a power of, for example, 150W, 200W or 250W.

[0024] According to another aspect, in combination with the above, a rail-mounted material transport lorry is proposed, comprising: a. a platform mounted on railway wheels, b. a push bar configured so that, when a pushing force is exerted by a user on the push bar, the lorry moves, and c. an electric assistance system as defined above, mounted on the lorry such that the drive element rotates one of the railway wheels when the drive shaft that carries it is rotated and such that the motor control system controls the power delivered by the motor according to the pushing force of the user acting on the push bar, such that when the pushing force is zero or less than a predetermined threshold value, the motor is stopped and when the pushing force is non-zero and greater than or equal to the predetermined threshold value, the motor drives the drive shaft with a power delivered proportional to a speed and / or acceleration controlled by the user.

[0025] Thanks to the lorry equipped with the electric assistance system, it is possible to move loads faster and with less physical effort, which increases productivity and reduces downtime.

[0026] In addition, the presence of the electric assistance system on the lorry, because it reduces the need for intense physical effort, helps to reduce the risks of injury and accidents to operators caused by the handling of heavy loads.

[0027] Furthermore, by reducing the physical load on operators, the lorry equipped with the electric assistance system helps to improve working conditions and reduce fatigue, which can also have a positive impact on safety and quality of work.

[0028] Moreover, the presence of the electric assistance system on the lorry makes handling tasks accessible to a greater number of operators, including those who may have physical limitations or difficulties handling heavy loads.

[0029] The lorry thus equipped remains a handling tool powered by the user, who is responsible for starting and stopping it. The lorry is neither self-propelled nor remote-controlled. If the operator does not move the lorry forward by pushing it, then the electric assistance system does not activate. However, as soon as the operator generates movement of the lorry, the electric assistance system activates upon reaching a predetermined threshold value, which is, for example, a lorry speed. Reaching a predetermined speed threshold value triggers the electric assistance provided by the electric assistance system. It should be noted that the push bar acts as a brake. passive, such that it prevents the lorry from moving forward unless it is activated. Thus, if no action is taken on the push bar, the lorry does not move forward and is even slowed down. If a pushing action is taken on the push bar, then the lorry can move forward.

[0030] Railway wheels are adapted to run on railway track rails.

[0031] Of course, the lorry only moves if the pushing force exerted by the user is sufficient. Furthermore, the lorry advantageously includes a mechanical parking brake. In this case, the lorry only moves if the mechanical parking brake is disengaged. If the brake is engaged, then the lorry cannot be moved.

[0032] The traction motor can be mounted on the lorry so as to be integrated into the centerline of a rail on which the lorry is intended to run. When there are two traction motors, each traction motor can be mounted on the lorry so as to be integrated into the centerline of a rail on which the lorry is intended to run.

[0033] The traction motor may include a reducer chosen such that the reduction ratio is a function of the diameter of the drive element, in particular the roller, and of the contact surface on the wheel, in particular on the wheel tread.

[0034] According to another aspect, in combination with the above, a method for driving a lorry as defined above is proposed, comprising: a. to exert, by a user, a pushing force on the push bar, b. capture the thrust force, and compare this thrust force to the threshold value predetermined, c. if the thrust force is greater than or equal to the predetermined threshold value, drive the drive shaft with the traction motor so as to cause said one of the wheels to rotate, d. to link the drive speed of said one of the wheels to the speed and / or acceleration controlled by the user.

[0035] We thus have a method of electrically assisting a lorry which helps the user pushing the lorry in his effort, so as to significantly reduce the latter.

[0036] The pushing force can be captured by a speed sensor configured to measure the speed of movement of the lorry.

[0037] Steps c and d can be implemented, based on the measurements taken by the speed sensor, by the motor control system. Indeed, the latter is configured to control the power delivered by the motor according to the user's pushing force acting on the push bar, such that when the pushing force is zero or less than a predetermined threshold value, the motor is stopped, and when the pushing force is non-zero and greater than or equal to the predetermined threshold value, the motor drives the motor shaft with a Power output is proportional to a speed and / or acceleration controlled by the user. The control system includes, in particular, a programmable logic controller (PLC), a motor control drive, and / or a DC / DC converter. The PLC is preferably programmed to control the power output of the motor based on the thrust applied, preferably as described above.

[0038] The method may include a preliminary step in which the user deactivates the lorry's mechanical parking brake. Information on the activation status of the mechanical parking brake may be sent to the control system by a brake sensor. The control system may be configured to prevent the engine from running when the mechanical parking brake is activated. Brief description of the drawings

[0039] Other features, details and advantages will become apparent upon reading the detailed description below, and upon analysis of the accompanying drawings, on which:

[0040] [Fig. 1] shows schematically and in perspective an example of a lorry.

[0041] [Fig. 2] is another schematic and perspective view of the lorry of [Fig. 1].

[0042] [Fig.3] shows partially, schematically and in perspective an example of an electric assistance system to equip a railway lorry.

[0043] [Fig.4] is a partial schematic and perspective side view of an example of lorry equipped with the electric assistance system of the [Fig.3].

[0044] [Fig.5] is a schematic and partial perspective view from below of an example lorry equipped with the electric assistance system of the [Fig.3].

[0045] [Fig.6] is a schematic and partial perspective view of an example of a sensor brake that can be fitted to the lorry.

[0046] [Fig.7] is a schematic and perspective view of another example of a lorry.

[0047] [Fig.8] is a block diagram illustrating an example of a method for driving a lorry. Description of the implementation methods

[0048] In the various figures, the same reference numerals designate identical or similar elements. For the sake of brevity, only the elements that are useful for understanding the described embodiment are shown in the figures and are described in detail below.

[0049] In the following description, when reference is made to absolute position qualifiers, such as the terms "front", "back", "top", "bottom", "left", "right", etc., or relative position qualifiers, such as the terms "above", "below", "superior", "lower", etc., or to orientation qualifiers, such as "horizontal", "vertical", etc., reference is made, unless otherwise specified, to the orientation of the figures or the lorry in its normal position of use.

[0050] Reference is now made to Figures 1 and 2, which depict a rail-mounted material transport trolley, also known as a rail-mounted material transport trolley. The trolley has a platform mounted on rail wheels, adapted for travel on rails. In this example, there are four wheels, arranged approximately under the four corners of the rectangular platform. The platform allows for the placement of the material to be transported. The trolley is configured to be pushed by a user on foot to travel on the rails.

[0051] The lorry 1 also includes a push bar 4, which can also be called a lever. The user stands facing the push bar 4, next to the lorry 1. The push bar 4 is configured so that when a pushing force is exerted by a user on the push bar 4, the lorry 1 moves. Indeed, as can be seen in [Fig. 2], the lorry 1 has a mechanical parking brake 5 that acts to constantly brake the wheels 3. To activate the mechanical parking brake 5, the operator, for example, brings a release bar 4a of the mechanical parking brake 5 into contact with the push bar 4. The wheels 3 are then free to rotate, and the lorry 1 can move forward, independently of the electric assistance system that will be described below.The push bar 4 is positioned next to a handrail 6 mounted on the platform 2 and rising to a human height so that it can be easily held by a user, or forms all or part of the handrail 6 as in the illustrated example.

[0052] The lorry 1 also includes an electric assistance system 10, more clearly visible in Figures 3 to 5. The electric assistance system 10 is configured to equip the lorry 1. The electric assistance system 10 comprises an electric battery 11, an electric traction motor 12 powered by the battery 11, and a drive shaft 13 rotated by the motor. The battery, for example, has a useful energy capacity of 750 Wh, and is removable and rechargeable. In other examples, the battery may have a useful energy capacity greater than 750 Wh, within a range of values ​​from 750 Wh to 3000 Wh, for example, 1500 Wh. The electric traction motor 12 is, for example, a traction motor with a power rating of 200 W.

[0053] The electric assistance system 10 further comprises a drive element 14 carried and driven in rotation by the drive shaft 13. The drive element 14 is configured to drive one of the wheels 3 in rotation when it is itself driven in rotation by the drive shaft 13. In this case, the drive element 14 comprises a roller and is configured to drive the wheel 3 in rotation by friction, as more clearly shown in [Fig. 5]. To achieve this, the roller is mounted on a rotation axis perpendicular to the track axis and parallel to the rotation axis of the wheel 3. A shaft parallel to the rotation axis of the roller is driven in rotation by the motor. This shaft is connected to the rotation axis of the roller by a chain, as shown, such that the The rotational movement of the shaft is transmitted to the rotational axis of the roller. Other types of motor, shaft and drive element assemblies can be considered, being functionally responsible for driving the rotation of the railway wheel 3.

[0054] The electric assistance system 10 further includes a control system 15 for controlling the motor 12. The control system 15 is configured so that, when the electric assistance system 10 is mounted on the lorry 1, it regulates the power delivered by the motor 12 according to the pushing force exerted by the user on the push bar 4, such that when the pushing force is zero or less than a predetermined threshold value, the motor 12 is stopped, and when the pushing force is non-zero and greater than or equal to a predetermined threshold value, the motor 12 drives the motor shaft 13 with power delivered proportional to a speed and / or acceleration controlled by the user. The control system 15 may, for this purpose, include a programmable logic controller (PLC), a motor control drive, and a DC / DC converter.

[0055] The electric assistance system 10 comprises, as shown in Figures 1 and 2, an electrical box 16 housing the control system 15 and, in this example, the battery, as well as a speed measurement sensor, not shown in the figure for the sake of clarity. In this example, the electrical box 16 is mounted on a second handrail 17 located next to handrail 6, but it could be mounted on handrail 6 without exceeding the scope of this illustration.

[0056] In the example illustrated in Figures 3 to 5, the traction motor 12 is mounted on the lorry 1 so as to be integrated into the axis of the rail on which the lorry 1 is intended to travel. In other words, the assembly comprising the motor 12, the drive shaft 13 and the drive element 14 extends longitudinally along the axis of the rail on which the lorry 1 travels.

[0057] In the illustrated example, the motor 12 includes a reducer chosen such that the reduction ratio is a function of the diameter of the drive element 14, in particular the roller, and of the contact surface on the wheel 3, in particular on the wheel's rolling surface.

[0058] Figure 6 shows an example of a brake sensor 18 attached to the mechanical parking brake 5 and configured to detect an activation state of the mechanical parking brake 5 and to transmit the information, in the form of an electrical signal, to the control system 15. The control system 15 is configured to inhibit the operation of the engine when the mechanical parking brake 5 is activated and to allow the engine to operate when the mechanical parking brake 5 is deactivated.

[0059] In an example illustrated in [Fig. 7], the electric assistance system 10 may include a second motor, which may be similar to the motor 12 previouslyThe electric assist system 10 advantageously includes a second drive shaft rotated by the second motor and comprising a second drive element configured to rotate another of the wheels 3 when mounted on the lorry 1. The electric assist system 10 can then equip, i.e., rotate, the wheels 3 that run on two different rails of the track and are located on the side of the push bar 4, i.e., at the rear of the lorry 1 when it is traveling on the rails, being pushed by a user, as in the illustrated example. In this case, each of the two motors is, for example, a traction motor with a power rating of 250W. The other two wheels 3 are then not equipped with the electric assist system 10.However, it could be envisaged that each of the wheels 3 of the lorry 1 be equipped with a part of the electric assistance system, with as many motors, drive shafts, and drive elements. Figure 8 shows various stages of an example of a lorry 1 drive method. The method includes a preliminary step 19 consisting of deactivating the lorry's mechanical parking brake, if present. The brake sensor can then send information to the control system 15 about the activation state, in this case "deactivated," of the mechanical parking brake, so that the motor can be started and controlled by the control system 15. When the lorry is stopped at the end of the journey, the user can then activate the mechanical parking brake, particularly for safety reasons.

[0060] The method then includes a step 20 consisting of a user exerting a pushing force on the push bar 4. Then the method includes step 21 consisting of capturing the pushing force, i.e. taking a speed measurement of the lorry 1, and comparing this pushing force to the predetermined threshold value, for example a speed of movement of the lorry 1 equal to 0.5 m / s.

[0061] If the thrust force is greater than or equal to the predetermined threshold value, in step 22, the drive shaft 13 is driven by the motor 12 so as to rotate a wheel 3 via the drive element 14. In step 23, the drive speed of the wheel 3 is controlled by the speed and / or acceleration controlled by the user. For this step 23, the control system 15 is used as described above.

[0062] It is of course possible to drive several wheels 3 and not just one, in which case the number of drive elements 14, but also of motors 12 and of motor shafts 13 will be equal to the number of driven wheels 3.

[0063] Finally, in a step 24, for example when the lorry 1 is brought to the objective point or step point, the user stops exerting a pushing effort on the push bar 4 so that the lorry 1 is automatically braked by the braking system 5, and the electric assistance system 10 is automatically interrupted.

Claims

Demands

1. Electric assistance system (10) for equipping a railway lorry (1) for transporting material on rails, the lorry (1) comprising a platform (2) mounted on railway wheels (3) and a push bar (4) configured so that, when a pushing force is exerted by a user on the push bar (4), the lorry (1) moves, the electric assistance system (10) comprising a. an electric battery (11), b. an electric traction motor (12) powered by the battery (11), c. a drive shaft (13) configured to be driven in rotation by the motor (12) and equipped with a drive element (14) configured to drive in rotation one of said wheels (3) when mounted on the lorry (1), d.a control system (15) of the motor (12), configured to, when the electric assistance system (10) is mounted on the lorry (1), control the power delivered by the motor (12) according to the pushing force of the user acting on the push bar (4), such that when the pushing force is zero or less than a predetermined threshold value, the motor (12) is stopped and when the pushing force is non-zero and greater than or equal to a predetermined threshold value, the motor (12) drives the motor shaft (13) with a power delivered proportional to a speed and / or acceleration controlled by the user.

2. Electric assistance system (10) according to claim 1, comprising an electrical box (16) housing the control system (15) and the battery (11), as well as a speed measurement sensor.

3. Electric assistance system (10) according to claim 1 or 2, wherein the control system (15) comprises a programmable logic controller, a motor control drive and a DC / DC converter.

4. Electric assistance system (10) according to any one of the preceding claims, wherein the drive element

5.

6. (14) includes a flanged drive roller configured to drive the railway wheel (3) by friction. Electric assistance system (10) according to any one of the preceding claims, comprising a second motor and a second drive shaft driven in rotation by the second motor and comprising a second drive element configured to drive in rotation another of said wheels (3) when mounted on the lorry (1). Rail lorry (1) for transporting equipment on rails, comprising: a. a platform (2) mounted on railway wheels (3), b. a push bar (4) configured so that, when a pushing force is exerted by a user on the push bar (4), the lorry (1) moves, c. an electric assistance system (10) according to any one of the preceding claims, mounted on the lorry (1) such that the drive element (14) drives one of the railway wheels (3) in rotation when the drive shaft (13) which carries it is driven in rotation and such that the control system (15) of the motor (12) controls the power delivered by the motor (12) according to the pushing force of the user acting on the push bar (4), such that when the pushing force is zero or less than a predetermined threshold value, the motor (12) is at rest and when the pushing force is non-zero and greater than or equal to the predetermined threshold value, the motor (12) drives the drive shaft (13) with a power delivered proportional to a speed and / or acceleration controlled by the user.

7. Lorry (1) according to the preceding claim, comprising a speed sensor configured to detect a thrust force exerted on the push bar (4).

8. Lorry (1) according to one of the two immediately preceding claims, wherein the traction motor (12) is mounted on the lorry (1) so as to be integrated into the centerline of a rail on which the lorry (1) is intended to run.

9. Lorry (1) according to any one of claims 6 to 8, wherein the motor (12) comprises a reducer selected such that the reduction ratio is a function of the diameter of the drive element, in particular the roller, and of the contact surface on the wheel, in particular on the wheel tread.

10. A method for driving a lorry (1) according to any one of claims 6 to 9, comprising: a. exert, by a user, a pushing force on the push bar (1), b. capture the thrust force and compare this thrust force to the predetermined threshold value, c. if the thrust force is greater than or equal to the predetermined threshold value, drive the drive shaft (13) by the traction motor (12) so as to drive said one of the wheels (3) in rotation, d. to link the drive speed of said one of the wheels (3) to the speed and / or acceleration controlled by the user.

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