IMPROVED SELF-PROPELLED STREET WASHER

Abstract

 A self-propelled street washer (1) comprising: a chassis (10), which accommodates and supports a driving cab (20) with a driving position and preferably also a passenger position; a front axle comprising a pair of front wheels (32); a rear axle comprising a pair of rear wheels (42); at least one electric traction motor; at least one tank (3a, 3b, 3c) containing a washing liquid; at least one washing bar (4) for supplying the washing liquid under pressure to a street surface, a sidewalk or a general transit/walking surface; a pumping system (50) to pump the washing liquid from the tank (3a, 3b, 3c) to the washing bar (4); an electric power source (B) which powers both the pumping system (50) and the at least one electric traction motor; and preferably a washing gun.

Description

Field of application

[0001] The present invention relates to a self-propelled street washer, i.e. a vehicle driven by an on-board operator and provided with means which direct high-pressure water onto a street surface, a sidewalk or onto a general transit/walking surface.

[0002] The above-said self-propelled street washer finds thus a useful application in the field of cleaning and sanitizing urban areas, but it can be used also in industrial, trading or tourist areas, in general any place where the periodical cleaning of a relatively wide transit/walking surface is required.

Prior art

[0003] The self-propelled street washers are substantially vehicles provided with a washing bar, usually positioned in the machine front part, which has a series of nozzles for supplying water under pressure.

[0004] Those machines are normally used to clean streets and large areas, since they allow the work performed by a single operator to be made more efficient and rewarding. The washing bar allows in fact water (or other washing fluid) to be supplied under a very high pressure directly at the roadbed level, performing in a fast and effective way a hydraulic sweeping action leading the street waste at the side of the streetway, wherein it is generally collected in sewers or in other suitable draining structures.

[0005] By nature, those machines require a storage tank of the water used for washing, generally large-sized and located within a rear box portion with respect to the driving cab. A hydraulically-operated pump withdraws low-pressure water from the storage tank and it sends high-pressure water to the washing bar.

[0006] The capacious storage tanks generally determine a high fully-loaded mass of the street washer, which is put into motion by means of a diesel-powered heat traction motor having a relatively high power.

[0007] Street washers thus emit, during the operation thereof, polluting gases in the atmosphere, so concurring in increasing the degree of pollution of the areas where they are used.

[0008] Those machines further concur in increasing acoustic pollution. In fact, they continuously emit irritating high-intensity sounds and noises, mainly linked to the heat traction motor.

[0009] The above-said drawbacks are all the more important since street washers, by their nature of service vehicles, must necessarily be used also in critical urban areas generally closed to vehicle traffic, for example by virtue of the population density thereof and/or of the particular historical-architectural value thereof. In some cases the paradoxical situation thus occurs whereby the administration, which on the one hand must preserve the air quality and/or silence of determined areas barring access to vehicles, is obliged on the other hand to disregard its own rules to allow places to be cleaned.

[0010] From the above it results the need to manufacture urban vehicles, and particularly street washers reducing to a minimum air emissions and acoustic noise.

[0011] The street washers known in the field are however also provided with a series of hydraulic systems ensuring the operation of some of the machine systems.

[0012] In particular, besides the washing water pump, the street washer has a transmission system generally of the hydrostatic type and a hydraulic power steering system.

[0013] Those systems have further disadvantages of the street washer, linked in particular to the hydraulic system maintenance costs and times. The power steering system, moreover, makes the driver position not much comfortable both for potential oil losses from the ducts and for the high heat radiated by the pipes containing the hydraulic oil.

[0014] The technical problem underlying the present invention is to devise a self-propelled street washer which solves at least some of the above-said problems, and which ensures in particular a reduction with respect to the prior art in the polluting emissions while keeping the reliability and versatility of use of the machines known to date.

Summary of the invention

[0015] The solution idea underlying the present invention is to implement a street washer wherein all the machine functions are electrically powered, including the traction and the washing liquid pump, while keeping a high vehicle stability and the loading capacity thereof.

[0016] Based on that solution idea the above-said technical problem is solved by a self-propelled street washer comprising:

a chassis, which accommodates and supports a driving cab with a driving position and preferably also a passenger position;

a front axle comprising a pair of front wheels;

a rear axle comprising a pair of rear wheels;

at least one electric traction motor;

at least one tank containing a washing liquid;

at least one washing bar comprising a plurality of nozzles for supplying the washing liquid under pressure to a street surface, a sidewalk or a general transit/walking surface;

a pumping system which intercepts a fluid communication between the at least one tank and the washing bar;

wherein the pumping system and the at least one electric traction motor are both powered by an electric power source which can also provide the electric power supply of further functions of the self-propelled street washer.

[0017] The self-propelled street washer can further comprise a washing gun to allow the operator to perform a manual washing action of the transit/walking surface.

[0018] Preferably the pumping system comprises a pump driving electric motor powered by the electric power source and a pump coupled to the pump driving electric motor which draws the washing liquid from the at least one tank and conveys it towards the nozzles of the washing bar or towards the washing gun.

[0019] The electric power source is preferably embodied by a rechargeable battery pack.

[0020] The recharge of the battery pack can occur through an external battery charger or - preferably - through a motor-generator unit comprised it too in the street washer, comprising a heat engine, for example a petrol one, coupled to a current generator, provided in case with an inverter, to recharge the electric power source.

[0021] The current generator is preferably an asynchronous three-phase one.

[0022] This second hybrid-powered option has a considerable advantage with respect to the first one, since it allows a greater operating autonomy to be provided even in the presence of a limited-size battery pack, to the benefit of the capacity of the washing liquid tank (or tanks). And thus, even in the presence of work requirements - distance travelled and extension of the area to be cleaned - which could have not been realistically ensured by a totally-electrically-powered machine, the hybrid-powered machine can be used by the encharged administration with a considerable improvement on the environmental impact.

[0023] The hybrid-powered option is preferably of the plug-in type, i.e. it allows the battery group to be recharged both through the heat motor-generator unit, and by using an external electric power source, for example a suitable 220 Vac recharge column.

[0024] Preferably, the battery group is automatically recharged by the heat motor-generator unit, arranged to start automatically when the battery reaches a lower charge threshold (for example: 30%) and to shut down when the battery reaches an upper charge threshold lower than the full charge level (for example: 90%).

[0025] At the end of the shift, it is thus possible to recharge the battery by connecting the machine to the recharge column so as to reach 100% of total charge (full charge).

[0026] That expedient allows the use of the heat motor-generator unit to be optimized, avoiding energy-expensive recharge operations close to reaching 100% of battery charge.

[0027] In the presence of the motor-generator unit, the electric power source can provide a control board BMS; that BMS control board being configured to determine the ignition of the motor-generator unit when the electric power source is in a low charge state.

[0028] Due to that expedient, the recharge of the battery pack is automated avoiding the activation and deactivation of the motor-generator unit to be assigned to the operator. The two opposite risks of excessive use of the heat engine - which is activated only and exclusively in case of need - and of malfunctions linked to the complete or anyway excessive discharge of the battery pack are thus avoided.

[0029] It must be noted that the BMS control board, assisted in case by an external control electronics, can implement even sophisticated charge/discharge logics, for example taking into account external factors such as the estimated consumption and the actual transit in an environmentally sensitive area.

[0030] Preferably, besides the main rechargeable battery pack the street washer also comprises an additional battery, recharged it too during the motor-generator operation, with a lower voltage and with a heat engine ignition function.

[0031] Indicatively, the main battery pack can provide a 48V voltage, the additional battery a 12V voltage.

[0032] Preferably all the machine systems are electrically powered by the 48V battery pack, including the on-board uses characterized by relatively low electric consumptions, such as for example the computer interfaces and the services inside the driving cab, which a 24V current through suitable 48V-24V converters is provided to.

[0033] The main battery pack, besides ensuring the traction and the operation of the pumping group, can also power other system uses, such as for example an electric steering system of the vehicle.

[0034] Preferably the electric power source, i.e. the rechargeable battery pack, is located on the chassis in a barycentral or sub-barycentral position with respect to the self-propelled street washer.

[0035] That sub-barycentral position allows in particular an advantageous distribution of the fixed masses on the vehicle, ensuring in particular a low barycenter - with subsequent driving stability - even in void loaded conditions.

[0036] In the presence of the motor-generator unit, it is preferably located in a compartment delimited by at least one heat exchange wall between said compartment and the exterior of said self-propelled street washer, said heat exchange wall being a portion of a covering panelling of the self-propelled street washer.

[0037] Preferably, the motor-generator is located in a rear-upper position of the vehicle, so as to be enclosed on four sides by the panellings (upper, rear and side) which define the van. A ventilation grid is located on one or more of those panellings adjacent to the compartment, preferably on the upper one.

[0038] The self-propelled street washer can advantageously comprise a plurality of tanks arranged to contain the washing liquid, said tanks being separated from each other and displaced in distinct areas of the internal volume of the self-propelled street washer, not engaged by the encumbrances of said electric power source and of said motor-generator unit, if present.

[0039] The above-said segmentation of the tanks in several units advantageously allows a full occupation of the rear volumes of the vehicle without requiring conversely a complex and expensive manufacturing for those units. In essence, in fact, that expedient allows the volumes to be saturated with tanks of simple shapes - for example parallelepipeds made of six sheets welded to each other.

[0040] The plurality of tanks can comprise a first main tank located at least partially above the electric power source and a second main tank positioned behind the electric power source.

[0041] In the presence of the motor-generator unit, the compartment wherein it is contained can be delimited at the front by the first main tank and at the bottom by the second main tank. Thereby, the motor-generator unit is kept in the above-said accessible and easily ventilatable compartment and the battery pack in the above-said barycentral or sub-barycentral position.

[0042] The plurality of tanks can comprise an additional tank preferably integrated into the chassis of the self-propelled street washer.

[0043] The presence of said additional integrated tank allows a chassis to be arranged, which is common both to the street washer being the object of the present invention, and to sweepers of the known type - which only require a small tank of washing liquid. A manufacturer of both machines can thereby achieve considerable savings on manufacturing and storage costs.

[0044] The pumping system can be advantageously positioned above the additional tank, integrated into a rear bumper of the chassis, to be easily accessible for maintenance operations.

[0045] Further features and advantages will be more apparent from the following detailed description of a preferred, but not exclusive, embodiment of the present invention, with reference to the attached figures given by way of a non-limiting example.

Brief description of the drawings

[0046] 

Figure 1 shows a left side view of a preferred embodiment of the self-propelled street washer according to the present invention.

Figure 2 shows a rear view of the self-propelled street washer of figure 1.

Figure 3 shows a front view of the self-propelled street washer of figure 1.

Figure 4 shows a top view of the self-propelled street washer of figure 1.

Figure 5 shows a left side view of the self-propelled street washer of figure 1 wherein two potential positions of an arm of a rotating washing gun are represented.

Figure 6 shows a front view of the self-propelled street washer of figure 1 wherein two potential positions of an arm of a rotating washing gun are represented.

Figure 7 shows a top view of the self-propelled street washer of figure 1 wherein the path that a washing gun arm can cover and the spraying path of a machine washing bar are represented.

Figure 8 shows a detail of the washing bar of figure 7 sideways rotated to the right by 30°.

Figure 9 shows a right side view of the self-propelled street washer of figure 1 with the side and rear panellings removed wherein the components located inside the rear part of the machine can be seen.

Figure 10 shows a rear view of the self-propelled street washer of figure 9.

Figure 11 shows a left side view of the self-propelled street washer of figure 9.

Figure 12 shows a right side perspective view of the self-propelled street washer of figure 9.

Figure 13 shows a left side perspective view of the self-propelled street washer of figure 9.

Figure 14 shows a perspective view of the driving cab of the self-propelled street washer of figure 1.

Figure 15 shows a top perspective view of the interior of the driving cab of figure 14.

Detailed description

[0047] With reference to the attached figures, a preferred embodiment of the self-propelled street washer according to the present invention is generally identified with 1, adapted to wash streets, sidewalks or general transit/walking surfaces. The following description is done with non-limiting reference to the use in the context of that application.

[0048] That self-propelled street washer 1 is essentially composed of a base chassis 10 having a front portion 10a, above which a driving cab 20 is housed, and a rear portion 10b, above which an electric power source B is housed, a first and a second main storage tank 3a, 3b of the washing liquid and a motor-generator unit 6.

[0049] Possible position references used in the present description and comprising indications such as front or rear, below or above, or similar expressions, will always refer to the orientation of the chassis front and rear portions, corresponding to what is illustrated in figure 1.

[0050] In order to facilitate the understanding of the described preferred embodiment it must be noted that figures 1, 5, 11, 13 show the left side, figures 9 and 12 show the right side, figures 2 and 10 show the back and figure 3 shows the front of the self-propelled street washer 1.

[0051] In the described preferred embodiment, the above-said electric power source B is embodied by in a preferably 300Ah, 48Vdc lithium-ions battery pack (of the LiFeP04 type).

[0052] The battery pack is advantageously rechargeable through the motor-generator unit 6. That motor-generator unit 6 is composed of a heat engine, preferably a petrol one, to whose flywheel an electric current generator connected to the battery pack is directly coupled.

[0053] Preferably the heat engine is embodied by a petrol engine of the KUBOTA brand, model WG972, three-cylinder, aspirated, 962cc, liquid-cooled, maximum power equal to 24,2 kW at 3600 rpm., maximum torque equal to 70Nm at 2000-2500 rpm. The unit operation speed is equal to 2500 rpm.

[0054] The current generator can be a direct current generator, for example 48V, 200A equal to 9,5 kVA at 2500 rpm. In a preferred embodiment, the use of an alternate current generator is however preferred, into which an inverter which rectifies the current for the battery pack power supply is integrated. Advantageously, the inverter can talk with a BMS control board of the battery pack to modulate the electric power supply according to the specific charge requirements.

[0055] The battery pack is thus associated to the above-said BMS control board for managing the charge and discharge. In particular, the BMS board determines the ignition of the heat engine of the motor-generator unit 6 when the battery pack charge falls below a determined threshold recharging the battery pack through the current generator. When the battery pack is fully charged, the BMS board interrupts the recharge turning the heat engine off.

[0056] Preferably the chassis 10 of the self-propelled street washer 1 is an unibody chassis manufactured starting from high-resistance steel sheets, preferably Domex 700.

[0057] Due to the use of the above-said material and of the particular shaping of the chassis 10, that chassis 10 defines such a high torsional rigidity structure, tested by the Applicant with FEM finite element analyses (Finite Element Method), as to ensure limited overall dimensions of the machine and to house at the same time high-capacity washing liquid tanks. The chassis 10 further has a very high legal useful capacity and such a structure as to ensure an optimum distribution of the weights, both empty and loaded, equally distributed on both front and rear axles, allowing a better stability and a higher capacity to climb over the slopes during the use of the machine (up to 35% in slope). Finally, the chassis 10 allows a very accentuated steering to be performed ensuring an extreme handling of use in narrow and tortuous streets of old towns.

[0058] The self-propelled street washer 1 also comprises a front steering axle 31 and a rear axle 41 integral with the rear portion 10b of the chassis 10 and associated to a pair of front wheels 32 and a pair of rear wheels 42 respectively. Preferably also the rear axle 41 is steering in an automatic way and in counterphase with respect to the front axle 31 thereby facilitating the handiness in restricted working contexts and optimizing curve washing performances.

[0059] The steering system is completely electric and thus with respect to the traditional hydraulic system of the prior art it allows breaks and oil losses to be avoided and the levels of travel safety to be increased due to the use of sensors coupled to a board which allows steering to be automatically adjusted as a function of the vehicle speed. The self-propelled street washer 1 can further include a SBW (steer by wire) system to automatically adjust the steering hardness in relation to the travel speed allowing a soft and precise steering in all circumstances.

[0060] Each wheel 32, 42 is preferably provided with steel rims with a flange with five holes and 5,00-10" keying which mount 6,50-10-12pr-size tires. Hydraulic shock absorbers paired to stiffened springs allow shocks and vibrations due to street unevennesses to be effectively deadened.

[0061] Behind the rear axle 41 a rear bumper 60 is fixed to the rear portion 10b of the chassis 10.

[0062] The two generally parallelepiped-shaped main tanks 3a, 3b are preferably made of stainless steel sheets (e.g. Aisi 304) welded to each other.

[0063] In the here-described preferred embodiment, the self-propelled street washer 1 further comprises an additional fiberglass tank 3c integrated into the rear bumper 60 (see for example figure 9) which a steel anti-trapping bar is inserted into.

[0064] The additional tank 3c together with the two main tanks 3a, 3b, 3c ensure a total capacity of at least 1600 litres. The tanks 3a, 3b, 3c are communicating between each other and refillable with washing liquid through a loading system, provided with a delivery filter and overpressure piping with discharge to the ground, through a hydrant-like quick coupling, of the UNI G45 type used in Italy or of the type used in other countries (France, Spain, Germany, etc.).

[0065] A pumping system 50 is positioned above the additional tank 3c, which comprises a pump driving electric motor 51 - preferably of the three-phase type with a 4 kW rating at 48Vac - powered by the electric source B and a pump 52 - preferably of the piston type which operates at a capacity of 30 lt/min at a pressure of 60 bars. The above-said pump 52 withdraws the washing liquid, for example water and a possible cleanser, from at least one of the tanks 3a, 3b, 3c and conveys the higher-pressure water towards a washing bar 4 located in front of the driving cab 20 and supported by an arm of the washing bar 4b connected below the front portion 10a of the chassis 10. The pumping system 50 further comprises a suction filter and a safety valve.

[0066] The washing bar 4 is provided with front and side nozzles 4a wherefrom high-pressure water leaks for washing the street surface or sidewalks. Through suitable controls located in the driving cab 20, the operator to move the washing bar 4 up and down and incline it laterally to the right and to the left so as to direct the nozzles 4a in direction and near to the surface to be washed. To move the washing bar 4 a complete hydraulic system of 24Vdc solenoid valves can be used and connected to an electronic control unit in electric communication with the controls and a multifunction panel 35 located in the driving cab 20. The multifunction panel 35 and the functions thereof will be described in greater detail hereafter.

[0067] The washing bar 4 can be advantageously provided with a system of shock-resistant sensors. During the operation of the washing bar 4 the sensors emit ultrasonic or electromagnetic waves, which intercept the closest obstacle thereto and send the information to an electronic control unit connected to the electronic control unit which drives the moving system of the washing bar 4. In order to avoid breaks in case of accidental shocks the washing bar 4 can also be provided with a rubber shock-resistant mechanical system.

[0068] The additional tank 3c, the pumping system 50 and the components located above the rear portion 10b of the chassis 10 are covered with external sandwiched fiberglass panellings (fiberglass-soundproofing material-fiberglass) with a protective surface external GELCOAT layer, highly resistant to the corrosion caused by the brackish air. In particular, in figures 1-5 the right side 81, left side 82, rear 83 and upper 84 panellings are visible.

[0069] The small carpentry details are protected with a cataphoresis treatment. The painted details are treated according to these modes: degreasing and sandblasting, sealing of all the pre-existing joints, application of two coats of antioxidant catalyzed epoxy primer, sanding and following application of two coats of polyurethane enamel.

[0070] The self-propelled street washer 1 can advantageously comprise a washing gun arm 73 located above the upper panelling 84. That washing gun arm 73 is free to rotate around the fulcrum tracing an angle of 360°. A washing pipe 74 connected to a washing gun 75 runs along the washing gun arm 73, graspable by the operator OP when he is in the vicinity of the machine 1 outside the driving cab 20. On the upper panelling 84 there is moreover an automatic winding system 76 of the washing pipe 74, integral with the washing gun arm 73. The washing gun 75 can allow a double jet mode: pin power or directional fan jet.

[0071] The rotatable washing gun arm 73 and the winding system of the washing pipe 74 thus allow the operator to use the washing gun 75 to perform a manual washing of a surface around the self-propelled street washer 1.

[0072] The self-propelled street washer 1 provides an electric traction which is embodied by an electric traction motor, preferably a 48V 4,5 kW three-phase asynchronous alternate current one, connected to each of the two rear wheels 42. The transmission is electronically managed and intuitively controlled by the operator only through an accelerator pedal 24, a brake pedal 23 and a control lever of the travel direction.

[0073] The self-propelled street washer 1 is further provided with a braking system comprising a drum brake (preferably 200x40 Knott) on the front wheels 32 and laminar discs in oil bath on the rear wheels 42, double braking circuit with pedal control provided with an auxiliary braking system on each circuit. The breaking system further provides a parking brake of the electro-mechanical type at the electric traction motors of the rear wheels 42.

[0074] The self-propelled street washer 1 is preferably provided with an HAC (hill start assist control) electronic system, for the maximum ease and safety even in hill starts. Moreover, the transmission management electronics ensures the automatic breaking when the operator has the accelerator pedal 24 completely raised; in this condition, the self-propelled street washer 1 is still, the parking brakes are activated, to deactivate then automatically as soon as the operator presses the accelerator pedal 24.

[0075] Preferably all the machine systems are electrically powered by the 48V battery pack, including the on-board uses characterized by relatively low electric consumptions, as for example the computer interfaces and the services inside the driving cab, to which a 24V current is provided through suitable 48V-24V converters.

[0076] As it is evident from what is described above, all the systems of the self-propelled street washer 1 are totally electric. Particularly, the electric power source B powers the traction motors, the steering motors, the breaking system, and the pump driving motor 51 of the pumping system 50.

[0077] The on-board services and the solenoid valves of the hydraulic moving system of the washing bar are also powered by the electric power source B through the interposition of suitable 48V-24V converters.

[0078] An additional 12V battery 90 is instead arranged to ignite the heat engine of the motor-generator 6.

[0079] The vehicle lighting is consistent with the regulations of the highway code, the reverse-motion warning horn is present.

[0080] The self-propelled street washer 1 can further be provided with an energy recovery system during deceleration and breaking. This allows the battery pack to be recharged also during the washing and/or transfer steps increasing the operating autonomy.

[0081] With reference to figures 9-13 the way the electric power source B, the main tanks 3a, 3b and the motor-generator unit 6 are arranged in the space delimited at the bottom by the rear portion 10b of the chassis 10, above by the upper panelling 84 and laterally by the side panellings 81, 82 will now be described.

[0082] As it can be noted for example from figure 11, the electric power source B, i.e. the battery pack, is located above the rear portion 10b of the chassis 10 between the front axle 31 and the rear axle 41 more offset towards the front axle 31.

[0083] The battery pack, which represents a component having a considerable mass, is located in the above-described position in order to distribute the weights so as to have a low barycenter near to the chassis 10 which ensures the vehicle stability with both void and full tanks 3a, 3b, 3c, both on the flat and uphill/downhill (up to at least 35% in slope).

[0084] The first main tank 3a rests on a bracket derived above the battery pack, while the second main tank 3b is located above the rear portion 10b of the chassis 10 and adjacent behind the battery pack.

[0085] The motor-generator unit 6 is positioned in a compartment 6a delimited at the front by the first main tank 3a, at the bottom by the second main tank 3b, above by the upper panelling 84, laterally by the right 81 and left 82 side panellings and behind by the rear panelling 83.

[0086] As it can be noted from figures 9-13, in the compartment 6a it is possible to let air in for the cooling of the motor-generator 6 though a ventilation grid 91 mounted on the upper panelling 84 directly above the motor-generator unit 6. Moreover, once the right side 81, left 82 and rear 83 panellings are removed, the motor-generator unit 6 is easily accessible for maintenance and/or replacement operations. Also the pumping system 50 is easily accessible once the rear panelling 83 is removed.

[0087] The main tanks 3a and 3b, besides delimiting the compartment 6a, have such a shape and size as to occupy most of the space delimited by the side 81, 82 and upper 84 panellings and not occupied by the battery pack and by the motor-generator unit 6, so as to maximize the capacity to contain the washing liquid for the same external size of the self-propelled street washer 1.

[0088] With reference to figures 14-17 the driving cab 20 and the components and controls positioned therewithin will now be described.

[0089] The driving cab 20, composed of a fiberglass unibody and of a high-resistance steel chassis, tight, soundproofed, delimited by front and side walls, of transparent material with openable windows, and by an upper sunroof, comprises an internal driving position 21, where the operator positions himself during the driving of the self-propelled street washer 1.

[0090] Preferably, the driving cab 20 is constrained to the front part 10a of the chassis 10 by means of bushes and supports of the visco-elastic type so as to insulate the driving position 21 from the vibrations coming from the outside.

[0091] The front and side walls are made of fiberglass and there is a sunroof, to the benefit of the operator comfort.

[0092] The driving position 21 comprises a driving seat 22, a steering wheel 71, the brake pedal 23 and the accelerator pedal 24.

[0093] The driving seat 22 is preferably of the adjustable anatomical type, complete with security belt, adjustable side arm-rests and "dead man's" sensor. The control panel of the washing bar 4 is preferably positioned on the right door.

[0094] In the driving cab 20 there is an openable glass inspection door 38 on the floor to view and control the washing means.

[0095] The control lever of the travel direction 26 is located on the right side of the steering wheel 71 and on the left side a multifunction selector 27 to operate turn indicators, lights, windshield wiper, windshield washer and warning horn.

[0096] On the dashboard, in front of the steering wheel 71, there are various lights and push buttons serving to drive the vehicle (side lights, low beams, turn indicators, hazard key, emergency push button which stops the active functions of the self-propelled street washer 1 in case of emergency, and parking brake push button, ...).

[0097] The insertion lock of the ignition key is positioned on the right side, below the steering wheel 71, with three potential positions: NEUTRAL - no live circuit and extractable key; BOARD ON - live circuits; PARKING - side lights on and extractable key.

[0098] Preferably, the driving position 21 also comprises a plug for the on-board diagnostics which allows the interface with the on-board electronics to verify the state of the electric systems of the self-propelled street washer 1.

[0099] A passenger position is preferably mounted on the left side of the driving position 21.

[0100] The driving cab 20 is preferably provided with electric heating system, conditioned air, panorama windshield, single-pantograph-arm windshield wiper and electric windshield washing system, air suction system from the outside through a pollen/dust filter.

[0101] Two arms provided each with a door mirror are installed outside the driving cab 20.

[0102] A multifunction panel 35 is installed on the left of the steering wheel 71, by a swivelling and swinging support- preferably provided with keys and 7" LCD display - which represents the command and control unit of all the functions of the self-propelled street washer 1 and it has visual, audible and light controlling and warning indicators.

[0103] The multifunction panel 35 allows the operator to control and monitor all the functions and the equipment of the self-propelled street washer 1 both during the washing and during the transfer, to receive signalings of possible failures and breakdowns, and it is preferably connected by a CAN-BUS communication protocol to the vehicle electronics, i.e. to the electronic control units which drive the various systems of the self-propelled street washer 1.

[0104] Those control units control the whole machine operation, from the traction motors to the steering, from the driving electric motor of the pump 51 to the movement of the washing bar 4, the breaking system, comprising all operating functions. The statuses of the functions and the possible alarms thereof are then displayed on the display.

[0105] The multilingual display of the multifunction panel 35 transmits all the information and the operating parameters. In a suitable menu section the use and maintenance manuals in pdf. format can moreover be consulted.

[0106] An alternative embodiment of the self-propelled street washer 1 cannot provide the motor-generator unit 6 and the BMS control board, but it can use as an electric power source B a rechargeable battery pack by means of an external battery charger.

[0107] In the present alternative embodiment the battery pack can completely occupy the space above the rear portion 10b of the chassis 10 between the front axle 31 and the rear axle 41 and thus, in the absence of the motor-generator unit 6, the whole space above the battery pack can be occupied by the two main tanks 3a, 3b or by a single main tank.

[0108] In that case, the battery pack is preferably of the lead-acid PzS 48 Vdc TRACTION type, with a total capacity of 828 Ah, with a cell container of fertenated steel and complete with a kit for the centralized topping up. As an alternative it is possible to use a LiFe PO4 48 Vdc lithium battery, with a total capacity of 1000 Ah.

[0109] The battery charger can be instead of the electronic type, with 32A three-phase 380V power supply, at high frequency to optimize the charge and limit recharge times.

[0110] The self-propelled street washer according to the invention solves the technical problem and achieves several advantages.

[0111] Advantageously, the self-propelled street washer has an electric traction wherein at least one electric traction motor is powered da a battery pack. With respect to the heat-traction street washers of the prior art, the self-propelled street washer of the present invention allows both the gas pollution and the noise one, besides the traction motor maintenance costs, to be drastically reduced.

[0112] Advantageously, almost all the systems mounted on the self-propelled street washer, i.e. the transmission, the breaking system, the steering, and especially the pumping system, are of the electric type and thus electrically powered by the battery pack which powers the electric traction. Thereby, a drastic reduction in the use of hydraulic systems is obtained with a subsequent reduction in the associated maintenance costs.

[0113] The electric systems of the self-propelled street washer can be advantageously and effectively controlled by a centralized electronic system which makes use of a plurality of control units connected to each other by a CAN-BUS protocol.

[0114] Advantageously, the self-propelled street washer comprises a motor-generator unit to recharge the battery pack during the use of the machine. Thereby, the operator can use the self-propelled street washer without interruptions required to recharge the battery.

[0115] The battery pack charge is advantageously automatically managed by a BMS system which starts the heat engine of the motor-generator unit when the battery pack is almost discharged and shuts it down when the charge is completed. Not leaving the motor-generator unit ignition and shut-down to the discretion of the operator, it is possible to avoid the battery pack complete discharge or excessive charge.

[0116] Advantageously, the battery pack is positioned in a barycentral or sub-barycentral position above the chassis between the front axle and the rear axle. Thereby it is possible to distribute the masses so as to have a low barycentre which ensures the vehicle stability with both void and full tanks, both on the flat and uphill/downhill.

[0117] Advantageously, the motor-generator unit is positioned near to the upper panelling wherein a ventilation grid is mounted to ensure an adequate cooling of the motor-generator unit itself. In that position the motor-generator unit is moreover easily accessible to effect inspection, maintenance or replacement interventions.

[0118] Advantageously, the self-propelled street washer comprises two main tanks of such a shape and size as to maximize the occupation of the space not occupied by the battery pack and by the motor-generator unit.

[0119] The self-propelled street washer can further comprise an additional tank integrated into the rear bumper so as to increase more the overall washing liquid loading capacity. The additional tank can further represent a support base for the pumping system which is thereby in an easily accessible position.

[0120] The self-propelled street washer can further not include a motor-generator unit, reducing almost to zero the environmental impact of the machine itself.

[0121] Obviously, in order to meet contingent and specific requirements, a skilled in the art will be allowed to bring several modifications and alternatives to the above-described invention, all however falling within the scope of protection of the invention as defined by the following claims.

Claims

1. Self-propelled street washer (1) comprising:

a chassis (10), which accommodates and supports a driving cab (20) with a driving position (21);

a front axle (31) comprising a pair of front wheels (32);

a rear axle (41) comprising a pair of rear wheels (42);

at least one electric traction motor;

at least one tank (3a, 3b, 3c) containing a washing liquid;

at least one washing bar (4) comprising a plurality of nozzles (4a) for supplying said washing liquid under pressure to a street surface, a sidewalk or a general transit/walking surface;

a pumping system (50) which intercepts a fluid communication between said at least one tank (3a, 3b, 3c) and said washing bar (4);

characterized in that said pumping system (50) and said at least one electric traction motor are both powered by an electric power source (B).

2. Self-propelled street washer (1) according to claim 1, wherein said pumping system (50) comprises a pump driving electric motor (51) powered by said electric power source (B) and a pump (52) kinematically coupled to said pump driving electric motor (51) adapted to withdraw the washing liquid from said at least one tank (3a, 3b, 3c) and convey it towards said nozzles (4a) of said washing bar (4).

3. Self-propelled street washer (1) according to claim 2, wherein said electric power source (B) is embodied by a rechargeable battery pack; said self-propelled street washer (1) further comprising a motor-generator unit (6) comprising in turn a heat engine coupled to a current generator adapted to recharge said electric power source (B).

4. Self-propelled street washer (1) according to claim 3, wherein said rechargeable battery pack is also rechargeable by using an electric power source outside the machine.

5. Self-propelled street washer (1) according to claim 4, wherein said motor-generator unit (6) is arranged to automatically start when the rechargeable battery pack reaches a lower charge threshold and to shut down when the rechargeable battery pack reaches an upper charge threshold, lower than a full charge level.

6. Self-propelled street washer (1) according to one of claims 3-5, wherein said electric power source (B) is located on the chassis (10) in a barycentral or sub-barycentral position with respect to said self-propelled street washer (1).

7. Self-propelled street washer (1) according to claim 6, wherein said motor-generator unit (6) is located in a compartment (6a) delimited by at least one heat exchange wall between said compartment (6a) and the exterior of said self-propelled street washer (1), said heat exchange wall being a portion of a covering panelling (81, 82, 83, 84) of the self-propelled street washer (1).

8. Self-propelled street washer (1) according to claim 7, wherein said self-propelled street washer (1) comprises a plurality of tanks (3a, 3b, 3c) arranged to contain the washing liquid, said tanks (3a, 3b, 3c) being separated from each other and displaced in distinct areas of the internal volume of the self-propelled street washer (1) not engaged by the encumbrances of the electric power source (B) and of the motor-generator unit (6).

9. Self-propelled street washer (1) according to claim 8, wherein said plurality of tanks (3a, 3b, 3c) comprises a first main tank (3a) located at least partially above said electric power source (B) and a second main tank (3b) positioned behind said electric power source (B), said compartment (6a) being delimited at the front by said first main tank (3a) and at the bottom by said second main tank (3b).

10. Self-propelled street washer (1) according to claim 8 or 9, wherein said plurality of tanks (3a, 3b, 3c) comprises an additional tank (3c); said additional tank (3c) being integrated into the chassis (10) of said self-propelled street washer (1).

11. Self-propelled street washer (1) according to claim 10, wherein said pumping system (50) is positioned above said additional tank (3c), integrated in turn into a rear bumper (60) of the chassis (10).

12. Self-propelled street washer (1) according to one of claims 3-11, wherein said electric power source (B) provides a BMS control board; said BMS control board being configured to determine the ignition of said motor-generator unit (6) when the electric power source (B) is in a low charge state in order to recharge said electric power source (B).

Drawing