Irrigation apparatus

Abstract

An irrigation apparatus is described, comprising: - a mobile sprinkler device (40) for irrigating plots of ground or green spaces, connected to an irrigation water supply pipe (60), - a hose reel drum (50), around which the irrigation water pipe (60) is wound, - an electric motor (70) adapted to rotate the drum (50) in order to rewind the pipe once unwound with the sprinkler device (40) arranged in a position of interest (A), - a control unit (90) adapted to drive the electric motor, wherein said control unit (90) comprises data processing means (91) and a memory (92) where a firmware (95) is in- stalled and running, said control unit being adapted to keep the speed (Vel) for rewinding the pipe on the drum constant by setting a driving voltage (V) of the electric motor (70) having a decreasing trend from the initial instant (A) of pipe rewinding to the final instant (E) with the pipe completely rewound.

Description

[0001] IRRIGATION APPARATUS

[0002] The present invention concerns an irrigation apparatus, in particular an apparatus for irrigating green spaces, still more in particular a drum-type irrigation apparatus.

[0003] PRIOR ART

[0004] It is known in the state of the art to use irrigation systems for green spaces comprising self-propelled drums. The aforesaid systems generally comprise a mobile sprinkler to rainfall-like irrigate large I medium plots of ground; in particular, but not exclusively, the sprinkler is of the long range and high flow rate type, commonly used in agriculture to rainfall-like irrigate medium and large areas.

[0005] The sprinkler is connected to one end of a long water supply pipe, the opposite end of which is in turn connected to a hose reel drum, around which the pipe itself is wound; the drum is connected to a water source by means of a pump adapted to put the water itself under pressure.

[0006] The apparatus also comprises a hydraulic turbine driven by the irrigation water (on one part of which it is crossed), adapted to provide energy for the rotation of the drum; the aforesaid energy, through a mechanical gear transmission system interposed between the turbine and the drum, produces the rotation of the drum which in turn produces the winding of the pipe.

[0007] The sprinkler is carried by a sprinkler trolley (with wheels or slide-like) that rests on the ground and is pulled in translation on the ground, along the area to be irrigated; after the sprinkler has been placed in the desired position, normally with a totally or partially unwound pipe, the same sprinkler is pulled by the supply pipe that is simultaneously wound, with slow rotation, around the drum, on which it forms a large coil.

[0008] To perform a uniform irrigation (same amount of water per unit area) it is necessary that the rotation speed of the drum, while winding the pipe, can be varied in an adjustable way, since:

[0009] - while the pipe is being wound on the drum, the pipe is wound on layers of coil that increase in diameter;

[0010] - in the same irrigation step it may be necessary to vary the speed of advancement of the sprinkler on the ground; this typically occurs when the surface of ground to be irrigated borders a driveway, or has an irregular geometric shape, and in such cases it is necessary to vary the angle / direction of the sprinkler jet and consequently it is necessary to vary the speed of advancement of the sprinkler.

[0011] Therefore, a need felt in the sector is to allow a control of the rewinding speed of the pipe so that the rewinding speed of the pipe is almost constant throughout the path as the friction of the pipe on the ground is reduced during rewinding, thereby increasing the speed.

[0012] An object of the present invention is to meet these and other needs of the prior art, within the framework of a simple, rational and low cost solution.

[0013] Such object is achieved by the features of the invention reported in the independent claim. The dependent claims outline preferred and / or particularly advantageous aspects of the invention.

[0014] DISCLOSURE OF THE IN ENTION

[0015] The invention, particularly, makes available an irrigation apparatus comprising:

[0016] - a mobile sprinkler device for irrigating plots of ground or green spaces, connected to an irrigation water supply pipe,

[0017] - a hose reel drum, around which the irrigation water supply pipe is wound,

[0018] - an electric motor adapted to rotate the drum in order to rewind the pipe once unwound with the sprinkler device arranged in a position of interest,

[0019] - a control unit adapted to drive the electric motor, characterized in that said control unit comprises data processing means and a memory where a firmware is installed and running, said control unit being adapted to keep the speed for rewinding the pipe on the drum constant by setting a driving voltage of the electric motor having a decreasing trend from the initial instant of pipe rewinding to the final instant with the pipe completely rewound.

[0020] In this way, simply by acting on the driving voltage of the motor, a uniform irrigation of the ground or green space is obtained.

[0021] Preferably the apparatus comprises a sensor of the current absorbed by the electric motor, said control unit being configured to detect in successive periods of time, while the pipe is being rewound on the drum, the increase or decrease in speed based on the value of current detected by said sensor and to correct the driving voltage of the electric motor as a function of said value of current detected by the sensor to keep the speed for rewinding the pipe on the drum constant. In this way, with the irrigation apparatus of the present invention it is not necessary to have a speed sensor for measuring the winding speed of the pipe but only by means of the values detected by the current sensor it is possible to intervene on the driving of the electric motor to obtain a constant winding speed of the pipe.

[0022] Preferably said memory comprises a database containing data coming from a plurality of samplings made on the irrigation apparatus during the various steps of rewinding the pipe on the drum, said data comprising at least the values of current absorbed by the electric motor with corresponding values of voltage applied to the electric motor and corresponding pipe winding speed, said data being grouped into tables per single pipe with given length and diameter and said control unit being configured to set the driving voltage of the electric motor as a function of the comparison between the current absorbed by the electric motor and the data of current values present in the database.

[0023] Preferably, said control unit in each of said time periods is configured to detect, by means of said sensor, the current absorption by the electric motor, to scroll through the tables entered in the database to retrieve the table in which said current value is present, which corresponds to a value of winding speed of the pipe and a value of voltage applied to the electric motor, to calculate based on the aforesaid values a corrective factor to be added to or subtracted from the voltage currently applied to the electric motor so as to obtain the correct driving voltage to keep the speed for rewinding the pipe on the drum constant.

[0024] Preferably, said database contains data coming from a plurality of samplings made on the irrigation apparatus during the various steps of rewinding the pipe on the drum in various types of grounds and with various climatic conditions, said data being grouped into groups of tables per single pipe with given length and diameter, said control unit being configured to identify the type of ground in which the pipe is unwound from the current absorption value detected by means of said current sensor.

[0025] In this way, the correction to be imparted on the driving voltage of the motor is even more precise because the different types of friction of the pipe on the ground where the pipe is unwound are considered.

[0026] Preferably said control unit comprises a user interface from which a user can set the desired speed for rewinding the pipe on the drum.

[0027] Preferably, the irrigation apparatus comprises a frame comprising a front part from which the pipe is unwound, two side walls and a rear part opposite the front part, said rear part of the frame comprising said control unit and a compartment to accommodate at least one battery for powering the electric motor and the control unit.

[0028] In this way, the battery is arranged in a position of the irrigation apparatus that is more user-friendly.

[0029] Preferably said rear part has a bar-like shape and is transverse to the side parts of the frame and arranged at a height from the bottom greater than or equal to the height from the bottom of the rotation shaft of the drum.

[0030] In this way, the control unit is arranged in a position of the irrigation apparatus that is even more user-friendly.

[0031] Preferably the apparatus comprises closing means for making inactive the entire irrigation apparatus arranged in the rear part of the frame.

[0032] In this way, all the controls of the irrigation apparatus are arranged all close and in the same part of the frame for a greater user-friendliness.

[0033] Preferably said electric motor is arranged in a side part of the frame in a position between the rear part of the frame and a vertical plane passing through the axis of the rotation shaft of the drum.

[0034] In this way, the entire electrical part of the irrigation apparatus is arranged on the rear part of the frame or near it so as to be easily accessible by the user in the event of failures of some components or maintenance.

[0035] BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Further features and advantages of the invention will be more apparent after reading the following description provided by way of a non-limiting example, with the aid of the accompanying drawings.

[0037] FIG. 1 is a perspective view of an irrigation apparatus according to an embodiment of the present invention.

[0038] FIG. 2 is a top view of the irrigation apparatus of figure 1 .

[0039] FIG. 3 is a side view of the irrigation apparatus of figure 1 .

[0040] FIG. 4 is the other side view of the irrigation apparatus of figure 1 .

[0041] FIG. 5 is a rear view of the irrigation apparatus of figure 1 .

[0042] FIG. 6 is a cross-sectional view according to line VI-VI of the irrigation apparatus of figure 1.

[0043] FIG. 7 is a schematic side view of the irrigation apparatus of figure 1 . FIG. 8 is a schematic rear view of the irrigation apparatus of figure 1 with lowered rear part of the frame.

[0044] FIG. 9 is a more detailed view of the drum of the irrigation apparatus of figure 1 .

[0045] FIG. 10 is a front view of the drum of figure 9.

[0046] FIG. 11 is a cross-sectional view according to line XI-XI of the drum of figure 10.

[0047] Figures 12 and 13 are detailed views of the battery compartment with battery inserted (figure 12) and extracted (Figure 13).

[0048] Figure 14 is a cross-sectional view according to line XIV-XIV of the irrigation apparatus of figure 7.

[0049] Figure 15 is a schematic view of the control unit of the irrigation apparatus of figure 1 .

[0050] Figure 16 is a graph of the trend of the voltage V applied to the electric motor as a function of the number of layers of turns of the pipe of the irrigation apparatus of figure 1 .

[0051] Figure 17 shows various working steps of the irrigation apparatus of figure 1.

[0052] BEST MODE TO IMPLEMENT THE INVENTION

[0053] With particular reference to these figures, an irrigation apparatus, in particular for green spaces, has been indicated globally with 10.

[0054] The irrigation apparatus 10 comprises a frame 1 which is a box-shaped support structure. The frame 1 comprises a front part 11 , two side walls 12, 13 and a rear part 14.

[0055] The side parts 12, 13 of the frame 1 each carry a wheel 20 for transporting the irrigation apparatus 1 ; in particular the wheels are connected to the lower ends of the side parts 12, 13.

[0056] The rear part 14 and the front part 11 connect rear and front side parts 12, 13 respectively so that the side parts 12, 13 face each other. Preferably the front 11 and rear 12 parts are transverse to the side parts 12, 13.

[0057] The rear part 14 carries an arm 30 that allows the movement of the irrigation apparatus 10 by a user while the front part 11 comprises soil rest means 11 1 that allow the irrigation apparatus 10 to rest on the soil once arranged in an area of interest.

[0058] Preferably the front part 11 of the frame 1 comprises a support 112 for an irrigation device 40, preferably a rainfall-like irrigation device, of the irrigation apparatus 10.

[0059] The irrigation device 40 is connected to a pipe 60 adapted to carry water for the irrigation of the green spaces by means of the device 40; preferably the irrigation device is provided with means 113, for moving it on the ground, for example, a wheel or a pair of wheels or a slide.

[0060] Closing means 115, for example key locking means, are provided to make the entire irrigation apparatus 10 inactive; the aforesaid closing means are arranged in the rear part 14 of the frame 1.

[0061] The frame 1 carries a hose reel drum 50 better visible in figures 9-11 ; the drum 50 comprises a shaft 51 supported by the side parts 12, 13 of the frame 1. In particular, the side parts 12, 13 are both provided with a hole 100 in which a shaft 51 of the drum 50 is arranged; the shaft is arranged in the holes 100 so that it can rotate.

[0062] The shaft 51 is held in the holes 100 by means of supports 101 comprising bushes 102, preferably in stainless steel, in which the ends 510 of the shaft 51 are fitted. Preferably, a sealing ring 103 arranged between the end 510 of the shaft 51 and the bushing 102 and other sealing elements 104 are provided.

[0063] The drum 50 comprises two wheel-shaped side walls 53, preferably equal in size, opposite to each other and parallel to each other, and a perforated cylinder 54 arranged between them; the walls 53 are integral with the shaft 51 . The perforated cylinder 54, around which the pipe 60 is wound, has a diameter smaller than the wheel-shaped walls 53. The axis P passing through the shaft 51 represents the axis of symmetry for both the walls 53 and the perforated cylinder 54; the part of the walls 53 protruding outwards with respect to the perforated cylinder 54 allows the pipe 60 wound on the drum 50 to remain on the perforated cylinder 54, i.e. it contains the pipe 60 on the perforated cylinder 54.

[0064] Preferably, a bearing 105 arranged on the shaft 51 between each wall 53 and the respective side part 12, 13 of the frame is also provided.

[0065] Preferably one of the walls 53 is provided with a perforated rack or toothed wheel 55 fixed to the wall 53, for example by means of screws.

[0066] Preferably the shaft 51 of the drum 50 is partially hollow inside and is connected with an end part 61 of the pipe 60; preferably the end part 61 of the pipe 60 is connected with the portion 520 of the shaft 51 that is adjacent to the wall 53 which is in turn adjacent to the side part 13 of the frame 1 .

[0067] Preferably the end 510 of the shaft 51 that is arranged in the hole 100 of the side part 13 is solid while the end 510 of the shaft 51 that is arranged in the hole 100 of the side part 12 is hollow and is connectable to an external water supply source, preferably by means of a pump adapted to put the water itself under pressure. In this way the water deriving from the external source travels through the hollow part of the shaft 51 , the portion 520 of connection with the pipe 60 and the entire pipe 60 before reaching the sprinkler device 40.

[0068] The frame 1 , preferably the side part 12 of the frame 1 , comprises a support 120 for an electric motor 70, preferably in direct current and preferably a gear motor, adapted to move the drum 50, as better visible in figure 6 and in its detail. Preferably, a pinion 121 is provided integral with the electric motor 70 and adapted to move the perforated rack 55 with which it is coupled; in this way the electric motor transmits the rotation movement to the drum 50 to wind the pipe 60. The side part 12 of the frame 1 is preferably provided with a cover or casing 56 for the perforated rack 55, for the pinion 121 and for the electric motor 70.

[0069] There is also provided a splined shaft 45 arranged in the front part 11 of the frame 1 and adapted to arrange the pipe 60, when wound on the drum 50, in adjacent turns over the entire width of the perforated cylinder 54 and on several layers, for example up to 5 layers of adjacent turns. The splined shaft 45 is moved by the same electric motor through a connection between a toothed wheel 46 integral with the splined shaft, a toothed wheel 47 integral with the drum 50, in particular integral with the end 510 of the shaft 51 which is located in the side part 13 of the frame 1 , and a chain 48 for the transmission of the motion coupled to the toothed wheels 46 and 47, as better visible in figure 7. A cover or casing 57 of the chain 48 and of the two toothed wheels 46 and 47 is provided.

[0070] The electric motor 70 is arranged so as to be adjacent to the rear part 14 of the frame 1 , in particular near the control unit 90; in particular the electric motor 70 is arranged between the rear part 14 of the frame 1 and a vertical plane P1 passing through the axis P of the shaft 51. In this way, the entire electrical part of the irrigation apparatus 10 is arranged on the rear part 14 of the frame 1 or near it so as to be easily accessible by the user in the event of failures of some components or maintenance. Preferably, the electric motor 70 is arranged at a height from the bottom greater than or equal to the height from the bottom of the rotation shaft 51 of the drum 50; in this case, the electric motor 70 is more usable in the event of failures of some components or maintenance.

[0071] Preferably the electric motor 70 is powered by at least one battery 80 arranged in a compartment 85 of the frame 1 of the irrigation apparatus 10 and better visible in figures 8, 12-14; the compartment 85 is preferably closed by a door 800. Preferably the compartment 85 is arranged in the rear part 14 of the frame 1 of the irrigation apparatus 10; in this way the battery 80 is easily accessible for replacement thereof in the event of recharging or failure.

[0072] The at least one battery 80 is small in size and has a nominal power comprised between 90 and 300 Watts; the battery 80 is of the type normally used in benchtop power tools. Preferably the battery is of the LiHD lithium-ion type.

[0073] The compartment 85 comprises at least one support 84 for each battery 80; the support has a cavity 86 in the bottom, preferably of the rectangular type, such as to couple with the battery 80. In particular, the cavity 86 comprises side recesses 861 that engage with respective side projections 801 of the battery 80, as better visible in figure 14.

[0074] The battery 80 is coupled with the support 84 so as to be easily removable therefrom.

[0075] The support 84 comprises electrical contacts 841 which, when the battery 80 is inserted into the compartment 85 on the support 84, are in contact with the electrical contacts 802 of the battery 80.

[0076] The battery 80 is easily rechargeable once extracted from the support 84 of the compartment 85.

[0077] The battery 80 is of the interchangeable type.

[0078] A control unit 90 is provided, preferably arranged in the rear part 14 of the frame 1 , for driving the electric motor 70. The control unit 90 is also powered by the same electrical power source as the electric motor 70.

[0079] The control unit 90 comprises a user interface 900 comprising a display 901 and a keypad 902 to impart the user commands, as better visible in figure 15; preferably the user interface 900 is closed by a door 910.

[0080] Preferably, the control unit 90 is arranged near, in particular adjacent to, the compartment 85 of containment of the at least one battery 80; in this way, in the event that the control unit 90 signals the state of low charge of the battery, the user can immediately extract the battery 80 for replacement and / or recharging. In fact, the arrangement of the compartment 85 to accommodate the at least one battery 80 in the rear part 14 of the frame 1 adjacent to the user interface 900 of the control unit 90, facilitates the replacement of the discharged battery by the user after the user interface of the control unit 90 has signalled discharged battery.

[0081] The proximity of the closing means 115 to the user interface 900 of the control unit 90 allows to have all the user’s commands close so as to facilitate the user to use them.

[0082] The rear part 14 of the frame 1 has the conformation of a partially hollow bar, transverse to the side parts 12 and 13 of the frame 1 and arranged at a height from the bottom greater than the shaft 51 or equal to the shaft 51 of the drum 50. In this way, it is easier for the user to access both the control unit 90 and the compartment 85 of the at least one battery 80.

[0083] Preferably, the rear part 14 of the frame 1 , or at least the portion 98 of the rear part 14 that comprises the compartment 85 adapted to house the at least one battery 80 and the control unit 90, is arranged at a height from the bottom greater than the height from the bottom of the shaft 51 of the drum 50 with the means 111 arranged resting on the soil or ground. In particular, the rear part 14 of the frame 1 , or at least the portion 98 of the rear part 14 that comprises the compartment 85 adapted to house the at least one battery 80 and the control unit 90 and which is normally closed by a cover 99 that can be opened by a user, is arranged at a height H2 from the bottom S greater than the height H3 from the bottom S of the shaft 51 of the drum 50 by a given value H1 , for example 30 cm, with the means 111 arranged resting on the soil or ground; preferably, the value H1 indicates the difference between the height from the bottom H2 of the initial part of portion 98, which substantially coincides with the initial part of the cover 99, and the height H3 from the bottom of the shaft 51. This is to make access to both the control unit 90 and the compartment 85 easier for the user for maintenance purposes, but above all to make access to the user interface 900 much easier.

[0084] In particular, the compartment 85 and the control unit 90 are arranged substantially at the same height in the rear part 14 of the frame 1 .

[0085] The control unit 90 comprises a data processing unit 91 , for example a microprocessor, which exchanges data with a memory 92 where a firmware 95 for driving the electric motor 70 is installed and is running.

[0086] There is the user interface 900 that exchanges data with the control unit 90; in particular, the interface 900 allows the user to impart commands to the control unit 90 that drives the electric motor 70 for winding the pipe 60 once the pipe 60 has been completely or partially unwound so that the irrigation device 40 is arranged in the desired position The interface 900 comprises the display 901 and the keyboard 902 on which the user can act to impart commands to the control unit 90; however, it is also possible that the display is of the touch type so that the keyboard 902 is no longer necessary.

[0087] To ensure that the distribution of water is uniform over the entire surface, it is necessary that the linear rewinding speed of the pipe 60 is almost constant throughout the path.

[0088] In fact, there may be substantial variations depending on the following conditions: -during rewinding, the friction of the pipe on the ground is progressively reduced as the length of the pipe 60 stretched on the ground is reduced, consequently reducing the load on the electric motor 70.

[0089] -during rewinding, the pipe 60 will form turns that will wind the element 54 until at least a first layer of turns is obtained. Preferably, the pipe 60 will form several layers of turns forming a coil of the pipe 60 on the drum 50; the coil of the pipe 60 will have an increasingly greater diameter as the length of the pipe 60 on the ground decreases, so that at the same angular speed of the motor 70 the linear speed of the pipe on the ground increases with increasing rewinding diameter;

[0090] -the friction of the pipe 60 on the ground also varies as a function of the conditions of the ground itself (for example, the friction is greater if the ground is wet).

[0091] Typically the load of the electric motor 70 is higher if the pipe 60 is completely stretched, while it will tend to reduce as the pipe 60 is rewound.

[0092] The control unit 90 in accordance with the invention is configured to drive the electric motor 70 so that the rewinding speed Vel of the pipe 60 is constant.

[0093] A constant speed Vel is considered to be a speed that is maintained in the order of small variations on a constant value or an expected value, for example a speed that varies by ±1 Om / h on a constant value, preferably a speed that varies by ±5m / h on a constant value; that is, if a speed of 80m / h is desired, a speed comprised between 70m / h and 90m / h is considered constant speed, i.e. a speed of 80m / h ±10m / h, preferably a speed comprised between 75m / h and 85m / h is considered constant speed, i.e. a speed of 80m / h ±5m / h. This is because the irrigation apparatus 10, not being equipped with a speed sensor, loses accuracy compared to the irrigation apparatus equipped with a speed sensor.

[0094] In particular, in order for the rewinding speed Vel of the pipe 60 to be constant, the control unit 90 commands the electric motor 70 with a driving voltage V that decreases, preferably substantially linearly, with the increase in the number of turns of the coil of the pipe 60 being formed on the drum 50 (in particular with the increase in the number of layers of turns, no. of turns of the coil of the pipe 60 being formed on the drum 50), as visible from the graph in figure 16, that is, with a decreasing trend from the initial instant of pipe rewinding to the final instant with the pipe completely rewound.

[0095] The driving voltage V is linked to the current absorption I of the electric motor 70 and the load of the same electric motor; since the load of the electric motor 70 is higher if the pipe 60 is completely stretched while it will tend to reduce as the pipe 60 is rewound, the control unit 90 will vary the driving voltage V to keep the rewinding speed Vel of the pipe 60 constant.

[0096] The firmware 95 of the control unit 90 must perform the operation of applying the driving voltage V to the electric motor 70 in order to rewind the pipe 60 at the desired speed Vel, to detect in successive periods of time T, for example of 1 minute, the increase or decrease in speed that is generated with respect to the desired speed Vel, to correct the driving voltage V so as to return the speed to the value of the desired speed Vel.

[0097] In this way, the rewinding speed of the pipe 60 is kept stable as a function of the various conditions in which the machine is operating on the supply voltage V of the electric motor 70.

[0098] Said correction is made without the need for speed measurements coming from a sensor measuring the rewinding speed of the pipe but by detection of a current sensor 96, preferably a current transducer 96, adapted to detect the current absorption of the electric motor 70. Preferably, the current transducer 96 belongs to the control unit 90, more preferably to a control board of the control unit.

[0099] The memory 92 of the control unit 90 comprises a database 94 where tables Tb are stored and divided by a given length and a given diameter of the pipe 60, containing data relating to various values of pipe winding speed as a function of the length of the pipe 60 and preferably as a function of the friction values of the pipe 60 on the various grounds, wet, dusty, uneven etc.

[0100] Said data derive from samplings previously made on the field in the various steps of winding the pipe 60 on the drum 50. The samplings are made by driving the electric motor 70 with the nominal voltage coming from the electric source, for example from the battery 80.

[0101] Preferably, said samplings were also made considering the various steps of winding the pipe 60 on the drum 50 on grounds of different type.

[0102] The samplings were also made with different types of pipes 60, i.e. with pipes 60 of different length and diameter. The sampling data were divided into groups of tables relating to a given pipe 60, that is, a pipe 60 with a given length and a given diameter.

[0103] The voltage values that must be provided to the electric motor 70 are obtained from the samplings made on the field so that the winding speed Vel of the pipe 60 is kept constant. When the irrigation apparatus 10 is used, through the aforesaid samplings, the firmware 95 of the control unit 90 is able to correct the voltage applied to the electric motor 70 to keep the winding speed of the pipe 60 constant. The more data the various Tb tables contain, the more accurate the apparatus will be and the speed Vel will be close to the constant value or expected value.

[0104] For example, if a ground produces a greater friction, because it has rained and is therefore wet, compared to the ground in dry conditions, the current absorbed will increase because the electric motor 70 will struggle more.

[0105] As the absorbed current increases, there will be a lowering of the voltage at the ends of the motor 70, and therefore a decrease in speed Vel.

[0106] The control unit 90 notices this difference by detecting that the current absorbed by the motor 70 is greater than usual and will therefore generate a correction in such a way as to return the voltage at the ends of the motor to the expected value.

[0107] Once the voltage has been returned to the expected value, the speed Vel, which had dropped due to the greater resistance on wet ground, will also be returned to the desired value. This results in a not completely accurate speed control given the absence of a speed sensor but a satisfactory control for the applications in which the irrigation apparatus 10 is employed.

[0108] For example, if one wants a constant pipe 60 winding speed Vel of 80m / h and the voltage on the electric motor 70 is 10 Volts, at the beginning of the pipe 60 winding, when the load seen from the electric motor is greater, the voltage of 10 volts does not allow to obtain a speed of 80m / h. For this reason, the firmware 95 is triggered correcting the value of voltage to be applied to the electric motor 70. The correction is made based on the tables stored in the database 95 for that given pipe and based on the current I absorbed by the electric motor 70 that is detected by the current transducer 96; from the data on the samplings present in the database 94, the firmware 95 is able to calculate that the correct voltage to be applied to the electric motor 70 to obtain a constant pipe winding speed Vel= 80m / h at the initial instant of pipe 60 winding is 14.41109 Volts; therefore the firmware will correct the value of the voltage applied to the electric motor by adding a corrective coefficient or corrective or compensation factor Vcor= 4.41109 Volts.

[0109] Preferably the corrective or compensation factor Vcor can be higher or lower than the value of 4.41109 Volts depending on the type of ground on which the pipe 60 is unwound; in this case the database 95 comprises groups of tables for the given pipe in which the values of voltage to be applied to the electric motor differ based on the type of ground. The firmware is able to understand, based on the current value I absorbed by the electric motor 70, what the load seen from the electric motor 70 is and therefore in what type of ground the pipe 60 is unwound, correcting the voltage value to be applied to the electric motor 70 at the beginning of the winding operation of the pipe 60.

[0110] The correction is made every successive time period T for as long as necessary to wind the pipe 60 on the drum 50.

[0111] Therefore, at each time period T, for example of 1 minute, the current absorption I by the electric motor 70 is observed; the firmware of the control unit 90, based on the tables Tb of the samplings on the field that have been entered into the database and in which there is match between the current Ic absorbed by the electric motor, the voltage Vc on the motor and the winding speed of the pipe Vreal, identifies the speed Vreal corresponding to that precise current absorption, compares the aforesaid speed Vreal with the desired speed Vel and calculates the correction coefficient Vcor for the voltage to be applied to the electric motor 70 so that the speed of the apparatus is returned to the set speed Vel. This takes place for the successive periods of time T until complete winding of the pipe 60.

[0112] For example, a sampling table Tb stored in the database 95 for a pipe with a diameter of 0.042 metres and a length equal to 130 metres and with various real speeds Vreal close to the speed Vel= 80m / h is as follows: Where: no. of turns is the number of layers of turns

[0113] R is the radius of each layer of turns that is measured from the centre of rotation of the drum to the centre of the pipe

[0114] Wmot is the angular speed of the motor expressed in rpm

[0115] Vc is the applied voltage that decreases as the pipe 60 is rewound

[0116] Ic is the current absorbed by the electric motor

[0117] Vreal is the winding speed of the pipe of the irrigation apparatus without compensation, that is, when the control unit does not drive the electric motor

[0118] After applying the corrective coefficients to the driving voltage V of the electric motor 70, a constant pipe winding speed Vel=80 m / h is obtained with the following voltage values that can be enclosed in the following table:

[0119] Where: no. of turns is the number of layers of turns

[0120] R is the radius of each layer of turns that is measured from the centre of rotation of the drum to the centre of the pipe

[0121] Wmot is the angular speed of the motor expressed in rpm

[0122] V is the applied voltage that decreases as the pipe 60 is rewound

[0123] AV is the difference with respect to the previous voltage

[0124] The operation of the irrigation apparatus 10 is as follows.

[0125] The user, after arranging the irrigation apparatus 10 in a desired area, disengages the electric motor 70, in particular disengages the pinion 121 from the coupling with the rack 55, and, with the aid of the slide 113, unwinds the pipe 60 wound on the drum 50, in particular on the perforated cylinder 52, until the irrigation device 40 is arranged in the position of interest on the ground or green space, as per step A of figure 17.

[0126] The user then connects the pinion 121 with the rack 55 and then acts on the interface 900, in particular on the keyboard 902, to set the desired value of pipe rewinding speed Vel. In particular, the user can increase the pipe rewinding speed Vel up to a maximum speed or decrease it up to a minimum speed by acting on the buttons 902. The user connects the pipe 60 with an external water supply so as to introduce water, preferably under pressure, into the pipe 60.

[0127] Preferably it is also possible to select the length of the pipe 60 and the diameter of the pipe 60.

[0128] The firmware 95 of the control unit 90 will scroll through the tables of the database 94 to retrieve the table in which the pipe winding speed Vreal is located at the initial instant of pipe 60 rewinding. This speed Vreal corresponds to a voltage V applied to the electric motor 70 and a current I absorbed by the electric motor 70. The firmware 95 based on these values and the initial load values processes a corrective voltage coefficient Vcor to be added or subtracted from the voltage applied to the electric motor 70 to obtain the desired pipe winding speed Vel.

[0129] After a period of time T has elapsed, for example of 1 minute, from the initial instant the firmware 95 of the control unit 90 will read the current value I absorbed by the electric motor by means of the current transducer 96. Once said current value I is detected, the firmware will scroll through the tables relating to the sampling data to retrieve the table in which there is said current value Ic equal to the absorbed current value I to which a winding speed Vreal of the pipe 60 and a voltage Vc applied to the electric motor correspond. Based on these values of current Ic, speed Vreal and voltage Vc, the firmware 95 will determine the load on the electric motor 70 and calculate the corrective coefficient Vcor to be added to or subtracted from the voltage V currently applied to the electric motor 70 in order to obtain a pipe rewinding speed equal to the set speed Vel.

[0130] After another period of time T has elapsed, always of 1 minute, the firmware 95 of the control unit 90 will read the current value I absorbed by the electric motor by means of the current transducer 96. Once said current value I is detected, the firmware will scroll through the tables Tb relating to the sampling data to retrieve the table in which there is said current value Ic equal to the absorbed current value I to which a winding speed Vreal of the pipe 60 and a voltage Vc applied to the electric motor correspond. Based on these values of current Ic, speed Vreal and voltage Vc, the firmware 95 will determine the load on the electric motor 70 and calculate the corrective coefficient Vcor to be added to or subtracted from the voltage V currently applied to the electric motor 70 in order to obtain that the pipe rewinding speed is equal to the set speed Vel.

[0131] After a further period of time T has elapsed, always of 1 minute, the firmware 95 of the control unit 90 will read the current value I absorbed by the electric motor by means of the current transducer 96. Once said current value I is detected, the firmware 95 will scroll through the tables Tb relating to the sampling data to retrieve the table in which there is said current value Ic equal to the absorbed current value I to which a winding speed Vreal of the pipe 60 and a voltage Vc applied to the electric motor correspond. Based on these values of current Ic, speed Vreal and voltage Vc, the firmware 95 will determine the load on the electric motor 70 and calculate the corrective coefficient Vcor to be added to or subtracted from the voltage V currently applied to the electric motor 70 in order to obtain that the pipe rewinding speed is equal to the set speed Vel.

[0132] While the irrigation apparatus 10 moves from step A as completely unwound pipe 60 to step E as completely wound pipe and the splined shaft 45 arranges the pipe 60 in layers of turns superimposed on the drum 50, the firmware 95 of the control unit 90 in a succession of time periods T1 , T2...Tn, preferably all equal to the time period T, will read the current value I absorbed by the electric motor by means of the current transducer 96. Once said current value I is detected, the firmware 95 will scroll through the tables Tb relating to the sampling data to retrieve the table in which there is said current value Ic equal to the absorbed current value I to which a winding speed Vreal of the pipe 60 and a voltage Vc applied to the electric motor correspond. Based on these values of current Ic, speed Vreal and voltage Vc, the firmware 95 will determine the corrective coefficient Vcor to be added to or subtracted from the voltage currently applied to the electric motor 70 in order to obtain that the pipe rewinding speed is equal to the set speed Vel. The driving voltage V will have a decreasing trend from the initial instant of pipe rewinding, corresponding to step A of figure 17, to the final instant with completely rewound pipe, corresponding to step E of figure 17.

[0133] In the event that the values of the current absorbed by the electric motor 70 are entered in the tables of the database 94, in cases where the ground is wet, dusty, uneven, etc., from the value of the current I absorbed by the electric motor 70, the firmware is able to understand the condition of the ground and therefore the type of friction undergone by the pipe 60.

[0134] When the irrigation apparatus 10 is in step E, i.e. with the pipe 60 completely wound on the drum 50, a sensor 65, i.e. a proximity sensor, will signal the condition of completely wound pipe and command the consequent stop of the electric motor 70.

[0135] Keeping the rewinding speed of the pipe 60 constant allows uniform irrigation of the ground or green space.

[0136] In accordance with a variant of the embodiment of the invention, the irrigation apparatus 10 may comprise at least a first and a second battery 80. In this case, the firmware 95 of the control unit 90 is configured to allow the power supply of the electric motor 70 only from the first battery 80 and then from the second battery 80 when the first battery 80 is discharged; in this way the user can extract the discharged battery 80 and replace it with a charged one or can charge it after extracting it.

[0137] As shown in Figure 17, the apparatus 10 automatically rewinds the pipe 60 from phase A to phase E.

[0138] The apparatus 10 is preferably of the self-propelled or self-propelled drum type.

[0139] The invention thus conceived is susceptible to many modifications and variants, all falling within the same inventive concept.

[0140] Moreover, all details can be replaced by other technically equivalent elements.

[0141] In practice, the materials used, as well as the contingent shapes and sizes, may be whatever according to the requirements without for this reason departing from the scope of protection of the following claims.

Claims

CLAIMS1. Irrigation apparatus with drum comprising:- a mobile sprinkler device (40) for irrigating plots of ground or green spaces, connected to an irrigation water supply pipe (60),- a hose reel drum (50), around which the irrigation water supplypipe (60) is wound,- an electric motor (70) adapted to rotate the drum (50) in order to rewind the pipe once unwound with the sprinkler device (40) arranged in a position of interest (A),- a control unit (90) adapted to drive the electric motor, characterized in that said control unit (90) comprises data processing means (91 ) and a memory (92) where a firmware (95) is installed and running, said control unit being adapted to keep the speed (Vel) for rewinding the pipe on the drum constant by setting a driving voltage (V) of the electric motor (70) having a decreasing trend from the initial instant (A) of pipe rewinding to the final instant (E) with the pipe completely rewound.

2. Apparatus according to claim 1 , characterized in that it comprises a sensor (96) of the current absorbed by the electric motor (70), said control unit (90) being configured to detect in successive periods of time (T1 , T2...Tn), while the pipe is being rewound on the drum, the increase or decrease in speed based on the value of current detected by said sensor and to correct the driving voltage (V) of the electric motor as a function of said value of current detected by the sensor to keep the speed (Vel) for rewinding the pipe (60) on the drum (50) constant.

3. Apparatus according to claim 2, characterized in that said memory (92) comprises a database (94) containing data coming from a plurality of samplings made on the irrigation apparatus during the various steps (A,...E) of rewinding the pipe (60) on the drum (50), said data comprising at least the values of current (Ic) absorbed by the electric motor (70) with corresponding values of voltage (Vc) applied to the electric motor (70) and corresponding winding speed (Vreal) of the pipe (60), said data being grouped into tables (Tb) per single pipe (60) with given length and diameter and said control unit (90) being configured to set the driving voltage (V) of the electric motor (70) as a function of the comparison between the current (I) absorbed by the electric motor and the data of current values (Ic) present in the database.

4. Apparatus according to claims 2 and 3, characterized in that said control unit (90) ineach of said time periods (T1 , T2...Tn) is configured to detect, by means of said sensor (96), the current absorption (I) by the electric motor (70), to scroll through the tables (Tb) entered in the database (94) to retrieve the table in which said current value (Ic) is present, which corresponds to a value of winding speed (Vreal) of the pipe (60) and a value of voltage (Vc) applied to the electric motor (70), to calculate based on the aforesaid values a corrective factor (Vcor) to be added to or subtracted from the voltage currently applied to the electric motor (70) so as to obtain the correct driving voltage (V) to keep the speed (Vel) for rewinding the pipe on the drum constant.

5. Apparatus according to any one of claims 2 to 4, characterized in that said database (94) contains data coming from a plurality of samplings made on the irrigation apparatus during the various steps of rewinding the pipe (60) on the drum (50) in various types of grounds and with various climatic conditions, said data being grouped into groups of tables (Tb) per single pipe (60) with given length and diameter, said control unit (90) being configured to identify the type of ground in which the pipe is unwound from the current absorption value (I) detected by said current sensor (96).

6. Apparatus according to any one of the preceding claims, characterized in that said control unit (90) comprises a user interface (900) from which a user can set the desired rewinding speed (Vel) of the pipe (60) on the drum (50).

7. Irrigation apparatus according to claim 1 or 6, characterized in that it comprises a frame (1 ) comprising a front part (11 ) from which the pipe (60) is unwound, two side walls (12, 13) and a rear part (14) opposite the front part, said rear part (14) of the frame comprising said control unit (90) and a compartment (85) to accommodate at least one battery (80) for powering the electric motor (70) and the control unit (90).

8. Irrigation apparatus according to claim 7, characterized in that said rear part (14) has a bar-like shape and is transverse to the side parts of the frame and arranged at a height from the bottom greater than or equal to the height from the bottom of the rotation shaft (51 ) of the drum (50).

9. Irrigation apparatus according to claim 7 or 8, characterized in that it comprises closing means (115) for making inactive the entire irrigation apparatus (10) arranged in the rear part (14) of the frame (1 ).

10. Irrigation apparatus according to claim 7 or 8 or 9, characterized in that said electric motor (70) is arranged in a side part (13) of the frame at a position between the rear part(14) of the frame (1 ) and a vertical plane (P1 ) passing through the axis (P) of the rotation shaft (51 ) of the drum (50).

11. Irrigation apparatus according to claim 10, characterised in that said drum (50) comprises two walls (53) opposite each other and parallel to each other and integral with the rotation shaft (51 ) of the drum, one of said two walls being provided with a perforated rack or toothed wheel (55), said apparatus comprising a pinion (121 ) integral with the electric motor (70) for the movement of said perforated rack or toothed wheel (55).

12. Irrigation apparatus according to claim 7, characterised in that the front part (11 ) comprises ground rest means (111 ) of the irrigation apparatus, said rear part (14) being arranged at a height (H2) from the bottom (S) greater than the height (H3) from the bottom of the rotation shaft (51 ) of the drum (50) with said ground rest means arranged on the ground.

13. Irrigation apparatus according to claim 7, characterised in that said control unit (90) comprises a user interface (900) and is arranged in said rear part (14) of the frame near said compartment (85) to accommodate said at least one battery (80), the user interface (900) comprising a display (901 ) and a keypad (902) for entering user commands, or said display being of the touch type.

14. Irrigation apparatus according to any one of the preceding claims, characterised in that said irrigation device (40) is provided with means (113) for the movement thereof on the ground.

15. Irrigation apparatus according to any one of the preceding claims, characterised in that the apparatus (10) automatically rewinds the irrigation water supply pipe (60).

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