Hybrid and electric propulsion harvesting machine

Abstract

A self-propelled harvesting machine comprises a front harvesting unit (1) for harvesting raw agricultural products from the ground, such as tomatoes or peppers with corresponding leaves, lifting means (2) for the raw agricultural products collected by the front harvesting unit (1), at least one electrical operating unit receiving the raw agricultural products at the input and configured to separate a processed agricultural product, such as tomatoes or peppers, from agricultural waste, for example with corresponding plant parts and leaves, unloading means (6) for unloading the agricultural waste onto the ground, at least one mechanical operating unit (3) traction means (7), a power unit (5) configured to operate said mechanical and low voltage operating units and said traction wheels (7) and comprising an electric battery pack (B) an inverter unit (9) for converting AC / DC current into high voltage, a voltage converter device (13) powered by said batteries (B), in which said power unit (5) comprises a high voltage electric motor (HV-EM) electrically connected, via said AC / DC electrical conversion inverter unit (9), to said batteries (B), and via said voltage converter device (13) to said electrical operating unit (4), and mechanically to said mechanical operating unit (3) and to said traction means (7) and wherein the power unit (5) is arranged on the opposite longitudinal side of the vehicle with respect to the front collection unit, preferably behind the low voltage operating unit.

Description

[0001] “HYBRID AND ELECTRIC PROPULSION HARVESTING MACHINE” DESCRIPTION Filed of invention

[0002] The invention refers to the sector of self-propelled agricultural vehicles, specifically harvesting machines, such as tomatoes or peppers harvesting machines, configured to perform at least the cutting and picking step.

[0003] For example, machines of this type include "field opener" harvesters designed to cut from the ground, collect, and place the plants back on harvesting lines, and harvesters that, in addition to harvesting the plants from the ground, also sort the product, such as tomatoes or peppers. The invention can also be extended to other types of harvesting machines for vegetables, potatoes, and beets.

[0004] State of the art

[0005] Currently, self-propelled harvesting machines are known, comprising a frame to which a system for harvesting and displacing plants is attached. This system includes a cutting device for cutting plants from the ground, a lifting device for the cut plants, and an unloading device for unloading the cut plants back onto the ground and arranging them in a desired position, for example, in front of or to the side of the frame, according to harvesting lines determined by the vehicle's progress across the field.

[0006] EP3949716A1 , filed by the same applicant, describes a field opener of this type. It is also known that in recent years, phenomena associated with the consequences of climate change are posing ever-increasing challenges to all industries. In particular, one of the sectors that contributes most to global pollution is agriculture, and for this reason, even in the agricultural sector, increasingly stringent regulations are introduced regarding pollutant emissions, which risk compromising the normal functionality and operation of agricultural vehicles currently in use.

[0007] At the same time, there is an increasingly pressing need for increasingly efficient and performance-optimized agricultural vehicles capable of increasing productivity, especially given the rapidly growing world population, while addressing the need to address fossil fuel dependence. Preliminary studies on the canning production chain (dedicated to the industrial processing of tomatoes and peppers) show that large processors have long been committed to reducing their companies' CFP, with the harvesting phase an important component of the production chain. There has therefore been considerable interest in embracing a technology that strengthens the emission reduction plan and makes the industrial processing of tomatoes and peppers even more sustainable.

[0008] This requirement, however, is hampered by operators' need for vehicles that can perform the operations for which they were designed as reliably as possible, thus limiting their operating costs.

[0009] For this reason, agricultural machinery is currently often equipped with high- powered internal combustion engines to seamlessly perform even the most demanding work cycles.

[0010] However, while this extra power is useful in certain circumstances, in most cases the average load required of the engine is far lower than that corresponding to nominal operating conditions. This results in a loss of efficiency for the entire system, resulting in higher fuel consumption (and therefore operating costs).

[0011] The current state of the art therefore provides the need for harvesting machines capable of reducing the environmental impact of harvesting operations while ensuring the varying power levels required for the various processing phases.

[0012] Regarding the state of the art in reducing fuel consumption and electrifying large agricultural equipment and vehicles:

[0013] Hybrid and electric architectures for agricultural machinery. The process of electrifying agricultural machinery began with some concepts a few years ago, but progress was initially slow, with only sporadic projects. In recent years, the use of exhaust gas aftertreatment systems has been the most widely adopted solution for reducing polluting emissions per unit of work. However, more stringent emission limits have led to larger treatment systems, making vehicle integration difficult. Therefore, in recent years, alternative solutions have been explored to address emissions more effectively while optimizing onboard space. Hybrid electric technologies have emerged as a promising option in this regard. Over the past decade, the agricultural sector has been one of the most conservative and skeptical sectors when it comes to adopting new technologies. However, the advantages of electrifying traditional powertrains, the robustness of emerging technologies, and increasingly stringent emissions regulations are now pushing these industries to introduce new solutions. In large harvesting machines, in addition to the machine handling function which requires high power due to the overall weight of the machine, very different functions are required, starting from the collection of the product on the ground to the movement of the product on the machine using conveyor belts and in the sorting, up to the transport of the selected product into the final containers.

[0014] Scope of the invention

[0015] Given the limitations of the state of the art, a first scope of the present invention is to provide a harvesting machine equipped with an engine optimised to meet the average power requirements of the vehicle, combined with the action of a second engine, to accommodate power peaks during the most demanding phases of the work cycle.

[0016] Brief description of the invention

[0017] These objectives have been achieved by developing a hybrid / electric harvesting machine according to one of the attached claims. This includes a power unit for traction and for operating the machine's operating functions. The power unit comprises a high-voltage electric motor, controlled to power the traction and one or more machine functions, such as harvesting or lifting, at high voltage, and one or more low-voltage electric motors connected to respective devices at low voltage. In a preferred embodiment, the high-voltage electric motor is also coupled to a combustion engine, and two motors are arranged in parallel at the input of a gearbox that drives the traction and operating functions of the machine. With the solution adopted, a first advantage is that the power unit can effectively modulate energy use, supplying only the power required for traction and harvesting functions during the various phases of machine operation.

[0018] A second advantage of the invention is the reduction in emissions achieved compared to traditional solutions.

[0019] Another advantage is the possibility of coupling the electric motor with a relatively small internal combustion engine, easily and without substantial structural modifications, while still guaranteeing overload capacity comparable to traditional vehicles with large internal combustion engines.

[0020] Another advantage is the flexibility and modularity of the solution for further versions of the machine, for example, through partial or total electrification of onboard utilities and devices.

[0021] Another advantage is that the vehicle maintains the positioning of the main components essentially unchanged from a vehicle with an internal combustion engine.

[0022] Another advantage is the machine's architecture, as the powertrain compartment contains all the on-board energy generation and storage components, as well as the energy transformation at different voltage levels, as well as the possible transformation of energy from electric to motive to hydraulic. The hydraulic distributor will allow the functions of the different branches of the hydraulic system to be performed, while the lower-voltage electrical part will allow the on-board wiring of various product selection and sorting functions in areas of the machine where personnel may be present.

[0023] List of drawings

[0024] These and other advantages will be better understood by anyone skilled in the art from the following description and the accompanying drawings, given as non-limiting examples, wherein:

[0025] - Fig. 1 schematically shows a first embodiment of the harvesting machine of the invention;

[0026] - Figs. 2a-c show a three-quarter, rear, and side view, respectively, of a harvesting machine according to the diagram in Fig. 1 ;

[0027] - Fig. 3 shows a detail of the drive unit of the harvesting machine of Fig. 1 ;

[0028] - Fig. 4 schematically shows a second embodiment of the harvesting machine of the invention;

[0029] - Fig. 5 shows a detail of the drive unit of the harvesting machine of the invention according to the diagram in Fig. 3.

[0030] Detailed description

[0031] With reference to the attached drawings, preferred embodiments of a self- propelled harvesting machine according to the invention are described, preferably a machine with hydraulically powered wheels 7 driven by a hydrostatic unit 10.

[0032] With reference to Fig. 1 , the machine is equipped with front harvesting means 1 for harvesting plants and / or agricultural products, such as tomatoes or peppers, from the ground.

[0033] In different embodiments of the invention, the operational functions of the harvesting means 1 may be of different types and be implemented by a mechanical functional unit 3 of a known type, for example comprising multiple hydraulic pumps Pi that power a series of hydraulic actuators HSi corresponding to the various utilities and mechanical devices present on board the vehicle.

[0034] For example, in the case of an "open field" harvesting machine, a device for cutting the plants, a device for lifting the cut plants 2, such as conveyor belts extending from the ground to the machine, and a device for moving the harvested plants, for example, to the side of the machine, will be provided.

[0035] In the case of harvesting machines designed to both collect and sort products, appropriate sensors will also be provided, such as color, weight, and size sensors, managed by an electronic unit to reject or store the selected products. According to the diagram in Figs. 1 and 4, the mechanical functional unit 3 is mechanically connected to a power unit 5 comprising a high-voltage main electric motor HV-EM powered by a battery pack B, which also provides power to the hydrostatic unit 10.

[0036] According to the invention, the batteries B power the main motor HV-EM via a high-voltage AC / DC conversion inverter unit 9 and also power a power converter device 13 configured to power one or more electrical functional units at a different voltage level, such as 48V, composed of on-board utilities such as product collection augers, replacing traditional hydraulic motors.

[0037] For example, the electrical functional unit 4 may include one or more electric motors, preferably low-voltage EMi, powered by corresponding inverter devices, preferably low-voltage LVIi, which are in turn powered by the voltage converter 13. The electric motors and inverters are selected based on the output voltage of the converter 13.

[0038] Preferably, the characteristics of the HV-EM motor are as follows: - Nominal torque (Nm) 260

[0039] - Nominal speed (rpm) 2200

[0040] - Nominal power (kW) 60

[0041] - Peak torque (max 1 min) 390

[0042] - Tmax De-Rating (°C) 80

[0043] - Maximum length (mm) 420

[0044] - Maximum width (mm) 400

[0045] - Cooling: Liquid (water-glycol)

[0046] Advantageously, with this solution, it is possible to use an electric motor with nominal characteristics similar to those of an internal combustion engine in a similar traditional vehicle and at the same time power the on-board consumers at the desired voltage level, for example, in low voltage.

[0047] Specifically, the example described uses low-voltage EMi electric motors characterized by:

[0048] - Nominal torque (Nm) 15

[0049] - Nominal speed (rpm) 2000

[0050] - Nominal power (kW) 3

[0051] - Maximum torque (Nm) 30

[0052] - Tmax De-Rating (°C) 80

[0053] - Cooling: Air

[0054] - Planetary gearbox

[0055] - Reduction ratio 1 :8

[0056] - Efficiency 0.94

[0057] Advantageously, the solution adopted, using high-speed motors combined with a speed reducer, replicates the same maximum operating conditions as traditional hydraulic motors while still ensuring an adequate level of compactness.

[0058] Still referring to the diagrams in Fig. 1 and 4, preferred embodiments may include: a first low-voltage electrical distribution unit (LV-PDU) powered by the converter 13 and connected to the low-voltage inverter devices (LV) and to additional low- voltage devices 15 such as on-board electrical sensors and actuators, and a second high-voltage electrical distribution unit (HV-PDU) connected to the batteries B, the inverter 9, and one or more high-voltage electrical devices 14. With reference to the diagram in Fig. 4, the power unit 5 also comprises an internal combustion engine (ICE) mechanically connected to a gearbox 8 in parallel with the electric motor HV-EM according to a parallel hybrid scheme for driving both the traction drive and the mechanical functional unit 3.

[0059] Advantageously, with this solution, the HV-EM electric motor, coordinated by a control unit, appropriately increases the mechanical power available at the crankshaft according to the operational needs of the moment. It is therefore possible to use a smaller internal combustion engine than that used on a similar traditional reference vehicle, reducing emissions while maintaining the same level of performance.

[0060] The invention offers several technical advantages specific to the harvesting machine sector, characterized both by mechanical power requirements for demanding tasks such as, in addition to traction, cutting and handling plants and products, and by low-voltage equipment such as sensors for recognizing and sorting products for storage or waste.

[0061] In this context, thanks to the invention described above, it has been possible to reliably perform the operations for which harvesting machines were designed, limiting operating costs, while at the same time allowing the machine to seamlessly perform even the most demanding work cycles without resorting to oversizing the system.

[0062] The present invention has been described according to preferred embodiments, but equivalent variants may be conceived without departing from the scope of protection granted.

[0063] For example, the hydraulic fluid is biodegradable so that, in the event of leaks during field work, there is no contamination harmful to the crop.

[0064] Furthermore, the electric operating unit comprises, depending on the case, both a separation mechanism to obtain a processed agricultural product and a waste product, such as leaves, from the raw agricultural product collected by the front harvesting unit. This mechanism is, for example, a stirrer, preferably an eccentric one. The electric operating unit, alternatively or in combination, comprises one or more weight and / or color and / or size sensors and an electronic control unit receiving the sensor signals and programmed to identify the desired processed agricultural product based on the signals from the sensors and optical detectors. As illustrated in the figure, the power unit 5 is arranged behind, preferably behind, the electric operating unit 4 so as to allow maximum freedom in the layout of the agricultural product processing modules.

Claims

CLAIMS1 . Self-propelled harvesting machine, comprising a front harvesting unit (1 ) for harvesting raw agricultural products from the ground, such as tomatoes or peppers with corresponding plant parts and leaves, lifting means (2) for the raw agricultural products collected by the front harvesting unit (1 ), at least one electrical operating unit receiving the raw agricultural products at the input and configured to separate a processed agricultural product, such as tomatoes or peppers, from agricultural waste, such as leaves, unloading means (6) for unloading the agricultural waste on the ground, at least one mechanical operating unit (3) traction means (7), a power unit (5) configured to operate said mechanical and low voltage operating units and said traction wheels (7) and comprising an electric battery unit (B) an inverter unit (9) for converting alternating / continuous electrical current into high voltage, a voltage converter device (13) powered by said battery unit (B), characterized in that that said power unit (5) comprises a high voltage electric motor (HV-EM) electrically connected, via said inverter unit (9) for alternating / direct current conversion, to said battery unit (B), and via said voltage converter device (13) to said electric operating unit (4), and mechanically to said mechanical operating unit (3) and to said traction means (7) and wherein the power unit (5) is arranged on the opposite longitudinal part of the vehicle with respect to the front harvesting unit, preferably behind the low voltage operating unit.

2. Harvesting machine according to claim 1 , wherein said power unit (5) comprises an internal combustion engine (ICE) mechanically connected in parallel to the electric motor (HV-EM) to a gearbox unit (8) for operating the traction means (7) and the mechanical functional unit (3).

3. Harvesting machine according to one of the preceding claims, wherein said mechanical functional unit (3) comprises at least one hydraulically operated device (HSi) operated by a respective hydraulic pump (Pi) connected to the gearbox (8).

4. Harvesting machine according to one of the preceding claims, wherein said traction means comprise hydraulic or electric wheel motors (7) operated by a hydrostatic unit or one or more electric units (10).

5. Harvesting machine according to one of the preceding claims, wherein said electric functional unit (4) comprises at least one low voltage electric motor (EMi) connected to a respective low voltage inverter device (LVIi) powered by said high / low converter (13).

6. Harvesting machine according to claim 5, comprising a low voltage electrical distribution unit (LV PDU) powered by said voltage electrical conversion device (13) and connected to a plurality of said low voltage inverter devices (LVIi) and to one or more low voltage users (15) such as on-board electrical sensors and actuators.

7. Harvesting machine according to one of the preceding claims, comprising an electrical distribution unit (HV-PDU) connected at least to said batteries (B), to said AC / DC inverter (9) and to one or more high voltage electrical users (14).

8. Harvesting machine according to one of the preceding claims, wherein said harvesting unit (1 ) comprises means for cutting the plants from the ground.

9. Harvesting machine according to one of the preceding claims, wherein said lifting means (2) comprise conveyor belts spanning from said harvesting means to an on-board tank.

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