The present invention relates to a road sweeping machine of the type as recited in the preamble of the first claim.

In particular it relates to a road sweeping machine having a motor apparatus, a driving cab, a tipper bin and an intermediate compartment for the housing of said motor apparatus, provided with a catalytic reduction unit of the exhaust gas of the Euro VI type.

Similar devices are described in the patent applications US-A-4356589 and in FR- A-2912349.

As is known, road sweeping machines with a driving cab and tipper bin are widespread.

These sweeping machines are complex vehicles, which must not only ensure optimum cleaning operations and be compact in order to easily circulate in city spaces, but must also be able to tackle significant journeys to transfer the load to landfills or collection facilities outside the city.

Said journeys must be made rapidly and be reduced to a m inimum, ideally only at the end of a complete work cycle. As a result, these vehicles must also have - despite the compact size - a spacious tipper bin where the waste of several hours of work is accumulated.

Said needs require a powerful and efficient motor apparatus.

For this motor apparatus and the various elements that compose it, the lower portion of the road sweeping machine where the members that perform the cleaning operations are situated is not available, and the tipper bin is not available, because the volume of the same must not be reduced. Nor is it the best choice to have the motor apparatus in front of the driving cab, so as not to increase the size of the road sweeping machine in length, which must remain as compact as possible, and also not to reduce the visibility of the ground near the driver.

In this situation it is known of to provide an intermediate compartment between the driving cab and the waste collection tank for the motor apparatus.

The intermediate compartment may be relatively small in terms of thickness, in the longitudinal direction of the vehicle, because it uses - to house the motor apparatus - the entire width and height of the vehicle.

In practice, the intermediate compartment engages on average between 15 and 20 percent of the overall length of the vehicle.

!n said intermediate compartment in many cases a large tank for the water to be sprayed to prevent the raising of dust by the members performing cleaning is often placed.

The position of the intermediate compartment, encased between the driving cab and the tipper bin, requires specific technical solutions for certain members, in particular for the motor and the radiator required to disperse the heat absorbed by the cooling liquid of the engine.

The motor is housed in a transversal position to the forward drive direction of the vehicle and the radiator is placed on top of the intermediate compartment, in direct contact with the outside air.

The radiator must have very large dimensions and an efficient fan given that the road sweeping machine moves slowly and with many manoeuvres in the city, and thus without a significant flow of external air,

However, the intermediate compartment has a reduced and, desirably, as small a thickness as possible and therefore does not have space for a very large radiator, being a square shape on account of the presence of the fan.

In many cases the problem has been solved by subdividing said radiator into several portions or adjacent elements. By placing several radiators of a square shape side by side transversely to the forward drive direction of the vehicle, like a roof of the intermediate compartment, it is possible to obtain a generally adequate radiator apparatus.

However, if the machine is to be fitted with a particularly powerful motor, such as a diesel motor of a size similar or higher than 4000 cubic centimetres, it is seemingly impossible to contain the entire motor apparatus in the intermediate compartment without significantly increasing the thickness of the same.

A motor of such type may be needed for road sweeping machines with hydrostatic or hydraulic transmission, advantageous for an optimal control of the wheels, easy driving of the vehicle and the possibility of freely disposing of the ducts feeding the fluids, so as not to obstruct the cleaning members.

However, the hydrostatic transmission absorbs part of the power delivered by the motor and requires specific and additional members such as pumps and an oil tank to be placed in the intermediate compartment.

A high power motor is then needed to meet the increasing load capacity, the increasingly long journeys to landfills, and to fuel the increasingly efficient and complete cleaning members.

A large power output requires, according to Euro V! standards, a significant catalytic reduction unit including in terms of size, which in part must be positioned away from contact with the operator and staff and exposed to the air, to prevent dangerous overheating. It is thus necessary to also place the bulky elements of the catalytic reduction unit in the upper area of the intermediate compartment, where the radiant apparatus is already present.

The latter cannot be undersized, to leave room for the catalytic reduction unit, except by risking overheating of the engine, taking into account the fact that in traffic, road sweeping machines proceed slowly and with many manoeuvres, also actuating all the cleaning members and thus with the motor fully in action.

In this situation the technical task of the present invention is to devise a road sweeping machine able to occupy a limited space, while being equipped with all the members needed for satisfactory operation.

Within said technical task one important object of the invention to devise a road sweeping machine which comprises a motor apparatus which, while being endowed with great power can be contained in the transverse intermediate compartment of a road sweeping machine without increasing said intermediate compartment, and also maintaining exposed to the air both sufficient radiator members and a significant portion of the catalytic reduction unit provided for by Euro VI standards.

Another important object is to provide a road sweeping machine comprising a motor apparatus in which the various members are in a substantially optimal position for their operation.

A further no less important object of the invention is to provide a road sweeping machine comprising a motor apparatus in which the various members of said motor apparatus are easily accessible for servicing, replacements and checks. The technical purpose and specified aims are achieved by a road sweeping machine as claimed in the appended Claim 1 . Preferred embodiments are evident from the dependent claims.

The characteristics and advantages of the invention are clearly evident from the following detailed description of preferred embodiments thereof, with reference to the accompanying drawings, in which:

- Fig. 1 schematically shows a road sweeping machine having an intermediate compartment housing the motor of the road sweeping machine according to the invention;

- Fig. 2 shows said intermediate compartment in an isolated position, mounted on the vehicle chassis and with the internal support structure shown schematically;

- Fig. 3 shows the motor apparatus broken down into its basic components to be inserted inside the intermediate compartment;

- Fig. 4 shows, in a perspective view from above and from a lateral, anterior position to the road sweeping machine, how the components of the motor apparatus in Fig. 3 are made and arranged inside said intermediate compartment,

- Fig. 5 shows the motor apparatus in Fig. 4 in a perspective view from above and from a lateral rear position to the road sweeping machine; and

- Fig. 6 highlights some Euro VI elements of the motor apparatus.

With reference to the Drawings, reference numeral 1 globally denotes the motor apparatus according to the invention.

It is designed for a road sweeping machine 2 of the type having a chassis 3 having a main direction of extension in the forward drive direction 2a and supporting, in substantial alignment, a driving cab 4, a tipper bin 5, and a support structure 6 defining an intermediate compartment 7 placed between the driving cab 4 and the tipper bin 5. The members performing the cleaning operations, per se known, such as brushes, rollers, guides, activators and translatory bodies of the brushes, conveyors of the substances collected, suction and / or blower members, sprayers for spraying water, etc. are situated mostly under the chassis 3. Such members are schematically represented in Fig. 1 . Preferably under the chassis 3 the mechanical suction type cleaning members are placed, preferably comprising one or two lateral cup brushes, conveying the waste to a suction mouth or a vertical vane waste conveyor, located in a central position with respect to the transverse axis of the machine 2.

These bodies do not relate - at a structural level - to the present patent, with the exception of a large tank for water to be sprayed, which in many cases is inserted in said intermediate compartment 7, in combination with the motor apparatus 1 . In Figure 1 the driving cab 4 is shown with a very wide glass surface suitable for maximum visibility of the surrounding ground.

The tipper bin 5 is represented in the collection position, lowered onto the chassis 3, but the same can be lifted and tilted by appropriate pistons to permit the emptying by gravity of the collected waste.

The intermediate compartment 7 has a width and a height transverse to the forward drive direction 2a which are similar to those of the road sweeping machine 2 and a thickness, in the forward direction, less than said width and height.

By way of example, road sweeping machines are known of which have an overall length of about six metres, a width close to two metres and a height of about three metres above the ground, !n these machines the intermediate compartment 7 has a thickness, in the direction of the length of the vehicle 2, for example, between 15 and 20 percent of the length thereof. Desirably, the thickness is as reduced as possible, to keep the machine compact 2, facilitate its manoeuvres and in order to install a large tipper bin 5.

The intermediate compartment 7 is closed at least laterally by openable hatches or doors 7a and is substantially open above.

The doors 7a may be provided on both opposite sides of the intermediate compartment 7.

The motor apparatus 1 is inserted in the intermediate compartment 7, above the chassis 3, and is positioned and supported by the support structure 6.

!n the compartment 7 the motor apparatus 1 has a main motor 8 which is placed in a transverse position to the forward direction 2a and a radiant device or radiator 9 provided for the cooling liquid of the main motor 8, placed on the top, at least partially open, of the compartment 7, exposed to the outside air and in any case fitted with a wide fan 9a,

According to the invention, the motor apparatus 1 is highly complex, as shown in Figure s.

It includes - in addition to the main motor 8 and the radiant device 9 - a hydrostatic transmission fitted with specific pumps 10 driven by the main motor 8 and an oil tank 11 for the oil made to circulate, special filters for the entry of air into the motor, such as a pre-fiiter air cyclone 12a and a subsequent full air filter 12b, and a catalytic reduction unit 13 for the purification of flue gases, according to Euro VI standards.

Preferably, the main motor 8 is for example a modern diesei motor of large cubic capacity, 4000 cubic centimetres or more, of the type suitable for increasingly large loads, increasingly refined cleaning members, suitable to perform long and fast journeys to landfills, and also suitable for a hydrostatic transmission. The latter is advantageous for a full control of the wheels, for easy driving of the vehicle, for the possibility of freely disposing of the ducts which feed the fluids to the local control elements of the wheels, so as not to obstruct the cleaning members.

However the hydrostatic transmission absorbs part of the power supplied by the main motor 8, which for this reason too must be very powerful, for example over 100 kW.

Said main motor 8 requires a sizeable radiant device 9 exposed to the air, and a bulky cataiytic reduction unit 13 of the exhaust gas according to Euro VI standards, at least partly exposed to the air.

As for the cataiytic reduction unit 13, this comprises at least a first and a second cataiytic element 14, 15 powered directly by the motor and placed in a special box- shaped housing 16 next to the end portion of the exhaust pipe 17.

The catalytic reduction unit 13 then comprises a container 18 for an Aqueous Urea Solution [CO at 32.5%. Said solution is called AUS32 in technical terms and also AdBlue, the trademark of VDA (Verband der Automobilindustrie).

AUS32 is used in so-called Selective Cataiytic Reduction (SCR) to reduce emissions of nitrogen oxides of the exhaust gas of diesel motors.

The catalytic reduction unit 13 comprises a dispensing control unit 19 of the solution AUS32.

As shown schematically in figures 3 and 6, the dispensing control unit 19 injects the AUS32 solution between the first catalytic element 14 and the second cataiytic element 15.

The first cataiytic element 14 is of the passive regeneration type (CRT, Continuously Regenerating Trap) and includes a component 14a called DOC (Diesel Oxidation Catalyst), and a consecutive component 14b called DPF (Diesel Particulate Filter).

The second catalytic element 15 includes a component 15a called SCR (Selective Catalytic Reduction), and a consecutive component 15b called CUC (Clean Up Catalyst).

Overall, in the presence of a modern diesel motor which optimises combustion efficiency and reduces fuel consumption, the exhaust gases have little particulate and require mainly control of the nitrogen oxides. The exhaust gases enter the first catalytic element 14 rich in nitrogen oxides and, to a lesser extent, unburned hydrocarbons, carbon monoxide and particulate.

The latter in particular is treated in said first catalytic element 14.

Then, after introducing AUS32, the gases enter the second catalytic element 15 where the purification is aimed in particular at eliminating the nitrogen oxides.

Finally the gases leave the exhaust pipe 17 with no harmful components such as Water, Nitrogen, Carbon Dioxide.

Evidently, the bulkiest part of the catalytic reduction unit 13 and which must be exposed to the air for improved cooling is the box-shaped housing 16 containing the catalytic elements 14 and 15.

The raised position is also useful to have a short exhaust pipe 17 facing upwards. As regards the radiant device 9, the same is substantially flat and defines a main extension plane 9b, is substantially a rectangular shape and centrally engaged by the fan 9a.

As shown in figures 4 and 5, the radiant device 9 is placed alongside the box-like housing 16 of the catalytic reduction unit 13, on the top of the intermediate compartment 7. The dimension in thickness of the compartment 7 - in the forward drive direction 2a - is sufficient for the catalytic reduction unit 13, while the radiant device 9 requires dimensions well above said thickness of the compartment 7.

!n order to avoid enlarging the compartment 7, a single radiant element 9 extends in width to occupy ail the space left in width on the top of the compartment 7 - about slightly more than a metre - the radiant device 9 extends mainly downwards, inside the compartment 7.

In order to allow maximum aeration just the same, the upper side of the radiant device 9 is placed at the level of the top of the vehicle 2 and as rearmost as possible, while the extension plane 9b of said device, inside the compartment, is inclined.

Typically the extension plane 9b is inclined between 30° and 60° with respect to the forward direction 2a of the road sweeping machine.

In the drawings, the extension plane 9b is inclined by about 45° and the greatest inclinations are provided for when on the top of the intermediate compartment a smaller side of the radiant device 9 is placed horizontally and the larger sides extend downwards within the compartment 7.

As shown in figures 4 and 5, in the intermediate compartment 7 a water tank 20 is inserted, relatively thin in the direction of the length of the road sweeping machine 2, but with a large capacity since it extends greatly in width and height, like a wall adjacent to the tipper bin 5.

The water tank has recesses 20a counter-shaped to functional elements of said motor apparatus, in particular the container 18 of the aqueous urea solution and the respective dispensing control unit 19,

The recesses 20a are made at the base of the tank 20 and at a side edge thereof, near the door 7a, so as to be able to easily access the container 18, for filling with AUS32 or to replace the same.

Between the main motor 8, placed transversally to the forward drive direction 2a at the base of the intermediate compartment 7, and the box-shaped casing 16 containing the catalytic elements 14, 15, placed on the top of the compartment 7, the complete or main air filter 12b for feeding air to the motor is placed.

This filter is particularly bulky and is advantageously near the door 7a and the main motor 8.

The other filter, the pre-fiiter 12a, which constitutes the first air intake, is placed at the upper end of the intermediate compartment 7,

As show in figures 3, 4 and 5, the pumps 10 are integral with the main motor 8 and extend consecutively thereto under the radiant device 9, in a zone of the compartment 7 relatively free and permitting easy control of the pumps themselves and the relative connections.

The oil tank 1 1 , functionally connected to the pumps 10, is placed next to the water tank 20, on the side thereof closer to the pumps 10.

To avoid reducing the capacity of the water tank 20, the oil tank 1 1 has a narrow columnar extension.

Preferably, immediately below the main motor 8 and in a position immediately adjacent to the base of the intermediate compartment 7, a receptacle for the fuel 21 is also arranged.

The various elements described above, prepared and combined with each other in the intermediate compartment 7, are advantageously separated from each other. They are in fact supported individually and independently by said support structure 6 inside the compartment 7. This support structure 6 is made from a framework comprising a plurality of uprights, cross members and partitions 22, preferably metal, for supporting the motor apparatus 1.

The uprights, cross members and partitions 22 are joined to each other and integral with the chassis 3, for example, they are welded or connected by screw elements.

In detail, the main motor 8 and the pumps 10 are arranged consecutively to each other and transverse to the forward drive direction 2a in a lower housing 23 which extends for the entire width of the compartment 7, substantially immediately above the chassis 3,

At the level of the lower housing 23, laterally thereto, the recesses 20a made in the water tank 20 to house the container 18 of the aqueous urea solution and the dispensing control unit 19 of the solution are arranged.

This way the container 18 and the control unit 19 are immediately adjacent to the main motor 8 and above ail the container 18 is immediately accessible when the door 7a is opened.

The structure 6 thus forms a first and a second columnar housing 24, 25 arranged side by side and extending between the lower housing 23 and the top of the intermediate compartment 7.

The main air filter 12b, the box-shaped housing 16 of the catalytic reduction unit 13 and the radiant device 9 are placed separately from each other in said columnar housings.

In particular, the main air filter 12b and the box-shaped casing 16 are overlapped with each other and engage separate spaces of the first columnar housing 24, placed on the side of the recesses 20a. The radiant device 9 engages instead by itself the second columnar housing 25, so as to find ample space for its extension.

Behind the housings 23, 24, 25 - in the forward drive direction - the water tank 20 extends beside the oil tank 1 1 .

The latter do not, however, reach the top of the compartment 7, so as to leave it completely free for the box-shaped casing 16 and the radiant device 9,

The invention achieves the proposed objectives and permits important advantages.

!n fact, even in the presence of a limited space, even if in an optimal position for the needs of a road sweeping machine, and even in the presence of a motor apparatus which, given its high demands, has strongly accentuated dimensions, a compact structure and with the various members in optimal positions for their functional needs has been designed.

In particular, the catalytic reduction unit 13 and the radiant device 9, are optimally structured and positioned notwithstanding the magnitude of the latter, needed to avoid probable overheating of the main motor 8.

The main motor 8 is kept immediately above the chassis 3, so as to have maximum stability.

The main air filter is interposed, spacing them, between the main motor 8 and the box-shaped casing 16, preventing the latter from being fully struck by the heat of the main motor.

The oil tank 1 1 is in the same part of the compartment 7 where the pumps 10 are located, so as to facilitate all the connections.

The container 18 is then in a position where it can be refilled immediately, by opening the door 7a. The water tank 20 and the oil tank 1 1 thus create a sort of large and solid screen towards the tipper bin 5, making it possible to operate freely on the same, for example lifting or tilting it, without interfering with the motor apparatus 1 .

Ail the members may then be easily and individually extracted for inspection, servicing or replacement.

Variations may be made to the invention without departing from the scope of the inventive concept defined in the claims. Ail details may be replaced with equivalent elements and the materials, shapes and dimensions may be any within the scope of protection defined by the claims.