GB2045183A - Silencing and cooling vehicle engines - Google Patents

Abstract

A construction equipment motor vehicle, such as dump truck, tractor shovel or motor grader, has a cooling system for the engine 1 which includes a radiator 2 and a mixed flow fan 3. The fan 3 is located in a compartment 6 separated from the engine compartment, so that the air drawn through the radiator by the fan can be discharged directly to the atmosphere rather than through the engine compartment. This arrangement, together with the fact that the fan is a mixed flow fan (itself quieter than an axial or radial fan of corresponding throughput), enables a reduction in noise from the vehicle to be achieved. The air discharge from the fan compartment 6 is upwards, and the exhaust fumes from the pipe 12 are diluted in this flow. <IMAGE>

Description

SPECIFICATION Construction equipment motor vehicle This invention relates to construction equipment motor vehicles.

The invention provides a construction equipment motor vehicle which includes an engine, a radiator and a mixed flow fan for cooling the radiator, the engine and the fan being located in separate compartments which are arranged so that air drawn through the radiator by the fan is discharged from that compartment directly to the atmosphere.

Because the air that has passed through the radiator is discharged from the fan compartment directly to the atmosphere, rather than through the engine compartment as hitherto, a much smaller vent area is necessary for the engine compartment, and this enables a reduction in noise from the vehicle to be achieved. In addition a mixed flow fan, that is, a fan giving an output that has axial and radial components, itself is quieter than the conventional axial flow fan of corresponding throughput.

Advantageously, the fan compartment is so constructed and arranged that the air discharge vents are in the upper surface of the compartment giving an upward discharge. The exhaust system may terminate in the fan compartment, so that the noxious exhaust gases are filuted by the radiator cooling air.

In one arrangement, the engine compartment and the fan compartment may be arranged adjacent each other, and they may be separated by a common wall.

The wall and the plane of the radiator may be perpendicular to the centre-line of the vehicle, and the air inlet to the fan compartment may also be perpendicular to the centre-line of the vehicle, and may be at an end of the vehicle.

In another arrangement, which is applicable to a dump truck, the engine compartment may be located between the wheels in the usual way, but the fan compartment may be located at a level above the top of the engine compartment. This then aliows the fuel tank to be located forward of the engine, where the radiator was usually located. The cab may be mounted on one side of the vehicle and the fan compartment on the other.

The mixed flow fan may be driven buy a hydraulic motor: the motor may be driven by a pump driven by the engine. The speed of the motor may be dependent both on the coolant temperature and on the engine speed.

The invention is applicable to tractor shovels, dump trucks and motor graders, scrapers, dozers, road rollers and excavators.

The invention will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a schematic view of a tractor shovel; Figure 2 is a schematic view of the engine cooling system of the vehicle; Figure 3 is a schematic view of the hydraulic circuit for driving the fan; Figure 4 is a schematic side view of a dump truck in accordance with the invention; Figure 5 is a front view of the dump truck; Figure 6 is a sectional view of a part of the side of the dump truck; and Figure 7 is a schematic view of a part of the side of a motor grader in accordance with the invention.

Referring to Figures 1 to 3 of the accompanfying drawings, a tractor shovel has a rear-mounted engine and cooling system for the engine.

The cooling system for the engine 1 comprises an upright radiator 2, and a mixed flow cooling fan 3 driven by a hydraulic motor 4. An oil cooler 5 for the main hydraulic system of the tractor shovel is also mounted on the rear of the radiator 2. The fan 3 is located in a compartment 6 which is separate from the engine compartment 1, and is defined by the radiator itself, an end wall 7 parallel to and spaced apart from the radiator and two side walls 8 which join the ends of the end wall 7 to the respective ends of the radiator 2. The compartment 6 has a member 9 closing the bottom (one or more drain holes may however be provided) and the top is covered by an open-mesh grille 8a.

Air is drawn into the compartment 6 through a grille 10 at the rear end of the vehicle, and it passes through the radiator 2 and through the fan 3 in the direction of the arrows A. The fanf 3 is a mixed flow fan, that is, an approximately axial intake flow is converted to an outlet flow having both radial and axial components. Such a fan is quieter than the conventional axial flow fan. A duct or cowl 11 leads from the portion of the radiator through which air can pass to a circular rim positioned just inside the outside rim of the fan 3.

Air is discharged from the fan compartment in an upward diretion, directly into the atmosphere, and does not pass over the engine of the vehicle as hitherto. This makes it possible to reduce the area of, or to dispense with, vents in the engine compart ment, and this enables the noise generated by the vehicles to be substantially reduced. In the present case, there are no vents in the top or sides of the engine compartment, or in the end wall 7, although the bottom of the engine compartment may be open.

It should be mentioned that if desired, a small bleed hole would be provided in the end wall 7, to increase the airflow over the engine 1, but ot so great as to significantly reduce the air discharge through the grille 8a. Even if a bleed hole as such is not provided, there may well be, in any case, a minute leakage of air into the engine compartment: in other words, it is not necessary for the fan compartment to be airtight for the improvement in noise reduction to be achieved.

The radiator is a high density water to all radiator, in order to provide the restriction appropriate to this type of fan. The side walls 8, in the interests of reducing noise transmitted to the outside of the vehicle from the fan, may be of the order of half an inch thick.

The upward flow of cooling air from the fan compartment is taken advantage of in diluting the exhaust gases from the vehicle. The exhaust pipe 12 is led up through the cmpartment. This has the dual advantage that noise transmitted to persons stand ing by the vehicle is reduced (since the exhaust noise as well as the cooling air output is vented upwardly), while at the same time the toxic exhaust gases are diluted.

Referring to Figure 3, the hydraulic motor 4 is driven by a pump 13 which is in turn driven by the vehicle engine. The speed of the motor is controlled by means of a valve 14 which is in turn controlled by a thermostatic valve 15 located on the header tank of the radiator. When the engine is cold, switching valve 14 is fully open, allowing vitually all the oil from the pump 13 to bypass the fan motor 4 and return to a reservoir 16 causing the fan to idle.

As the coolant temperature rises, a wax-filled element in a probe of the thermostatic valve 15 varies the pilot oil flow to the switching valve 14, which progressively closes, increasing the main oil flow to the motor and thus the fan speed. The speed is thus dependent on coolant temperature. When a predetermined maximum temperature is reached, the switching valve 14 is closed and the motor 4 operates at maximum speed, this maximum speed itself depending on the engine speed since the pump 13 is driven by the engine. There is an upper limiting speed for the fan, however, which is reached at a predetermined engine speed.

An advantage of the use of the hydraulic motor 4 is that the fan can be (as here) remote from the vehicle engine. If desired, the radiator and fan could be located at the opposite end of the vehicle. On the other hand, the fan could be directly driven by the engine if desired; this would of course necessitate a driving connection through the end wall 7.

The cooling system is self-contained and can be made as a separate module to facilitate assembly.

In the described embodiment, the motor 4 is located on the side of the fan 3 adjacent the radiator 2. if desired, however, it could be located on the other side of the fan 3.

The cooling system could also be employed in a motor grader, or a dump truck, or a road roller, or an excavator.

Referring to Figures 4to 6, a dump truck has a fan compartment similar to that described for the tractor shovel but located above the level of the vehicle engine, level with the vehicle cab 17, but on the other side of the vehicle. This fan compartment gives a substantially downward air discharge.

Referring to Figure 5, the radiator 18 of the truck is in three sections and the fan compartment is defined by the radiator itself, two side walls 19, an end wall 20. and a top wall 2'1 which extends along the length of the radiator beneath the header tank 22. There are three mixed flow fans 23, each of the same type as shown in Figure 3, two arranged behind the outer sections of the radiator at the top, and the other arranged behind the central section of the radiator beneath. Three fans are provided since the radiator has to dissipate heat from the engine, but also from a retarder fitted on the vehicle.

The engine is arranged between the wheels in the conventional manner. An air cleaner 24 is shown above the engine. However, since the radiatorofthe vehicle is not positioned in the customary place in front ofthe engine, a tank 25 for diesel fuel for the vehicle is located at the front instead. The tank serves to attenuate noise from the engine, and the engine is also closed in at the sides and top, with resultant noise reduction. As with the tractor shovel, the fact that the radiator cooling air does not pass over the vehicle engine enables the noise to be reduced. The fans are driven by the same hydraulic means as for the first embodiment.

Figure 7 shows a part of a motor grader The fan compartment is similar to that in the tractor shovel and dump truck described above. The fan compartment is located adjacent a compartment housing the vehicle engine 26. The fan compartment has a mixed flow fan 27 similar to that shown in Figure 2 and is defined by an end wall 28 having an air intake grille, side walls, a bottom wall 29 and another end wall 30 which is common to the engine compartment. A cowl 31 is provided between the radiator 32 and the fan 26. The top of the compartment has a grille 33.

The air discharge from the fan compartment is upwards, and the air does not pass through the engine compartment, consequently allowing this to be largely enclosed in the interests of noise reduction. As with the tractor shovel, the engine exhaust 33 is located in the compartment, thereby diluting the exhaust gases.

The fan is driven hydraulically in the same way as for the first embodiment.

Claims (6)

1. Aconstruction equipment motor vehicle which includes an engine, a radiator and a mixed flow fan for cooling the radiator, the engine and the fan being located in separate compartments which are arranged so that air drawn through the radiator by the fan is discharged from its compartment directly to the atmosphere.

2. Avehicle as claimed in claim 1, wherein the fan compartment is so constructed and arranged that the air discharge vents are in the upper surface of the compartment.

3. A vehicle as claimed in claim 2, wherein the exhaust system terminates in the fan compartment.

4. A vehicle as claimed in any one of claims 1 to 3, wherein the engine compartment and the fan compartment are arranged adjacent each other, and are separated by a common wall.

5. Avehicle as claimed in claim 4, wherein the wall and the plane of the radiator are perpendicular to the centre-line of the vehicle, and the air inlet to the fan compartment is also perpendicular to the centre-line of the vehicle, and is at an end of the vehicle.

6. A construction equipment vehicle substantiatly as hereinbefore described with reference to, and as shown in, the accompanying drawings.