The invention relates to an engine cooling system on an agricultural vehicle, more specifically the invention relates to a fan shroud of the cooling system on the vehicle.

Agricultural vehicles, such as agricultural tractors require a number of radiators in order to cool working media, such as a water cooler for the engine, a transmission oil cooler, a hydraulic oil cooler, an intercooler and possibly a condenser for an air- conditioning system. It is common practice to arrange the radiators in series one after the other under the vehicle bonnet so that air from a fan positioned at the front of the vehicle drives air through the radiators. Radiators in this arrangement may result in a high resistance to air flow which can necessitate a larger fan, or can interrupt the air flow resulting in the radiator overheating.

To concentrate the flow of air from the fan to the first radiator, that is the first radiator downstream of the fan, the fan is usually provided with a fan shroud which projects in a direction towards the radiators. The fan shroud typically borders the circumference of the fan and extends a short distance parallel or substantially parallel to the longitudinal axis of the vehicle. With this arrangement, the fan shroud can be ineffective since there is a gap between the fan shroud and the radiator.

Moreover, in order to conduct maintenance or cleaning of the area between the fan shroud and the radiator of such cooling arrangements, the whole bonnet hood must firstly be removed or lifted which can be inconvenient as not all parts of the bonnet may be moveable. Secondly the fan shroud must be removed.

It is an object of the present invention to provide an engine cooling system which is effective and which is easily accessible. It is a further object of the invention to provide an improved fan shroud on an agricultural vehicle engine cooling system.

According to the invention there is provided an agricultural vehicle having a cooling system comprising a fan, said cooling system housed in a bonnet of the vehicle, wherein said bonnet when closed forms a part of a fan shroud of the fan for directing air in a direction parallel or substantially parallel to the longitudinal axis of the vehicle.

With this arrangement, part of the fan shroud extends up to a first radiator and thus can guide the air directly to the first radiator without the need for extra parts.

Preferably, a side panel of the bonnet forms a part of the fan shroud. More preferably, the side panel is partly or fully detachable from the bonnet. The side panel may be pivotally attached to the bonnet. In this way, the fan and area between the fan and radiator is easily accessible without the need for removing or lifting the whole bonnet.

Preferably, the bonnet and/or side panel is provided with sealing means to prevent loss of air to the atmosphere. In this regard, as much air as possible is driven from the fan to the first radiator.

Preferably, the bonnet is provided with two opposing side panels. The cooling system can thus be accessed from either, or both sides of the bonnet. More preferably, the fan is provided with an extended fan shroud which is

connectable to the side panel of the bonnet to form part of the fan shroud. When closed, the side panel of the bonnet assist in guiding the air from the fan towards the rear of the vehicle.

Preferably still, a complete fan shroud which extends from the fan to a first radiator comprises the bonnet, a mounting plate which extends from under the fan to a first radiator and a fan shroud part which extends from an upper part of the fan to the radiator. The bonnet preferably comprises side panels which form a complete fan shroud with the mounting plate and the fan shroud part.

In this way, when the bonnet is closed the mounting plate, side panels of the bonnet and an upper part of the fan shroud are all connected so that all the air from the fan is directed to the first radiator.

The invention will now be described, by way of example only, with reference to the following drawings in which:

Figure 1 is a side view of an agricultural tractor with the bonnet closed,

Figure 1 a is a perspective view of the bonnet of figure 1 ,

Figure 1 b is a side view of the bonnet of figure 1 a with a hood of the bonnet raised in which a cooling arrangement in accordance with the invention is shown,

Figure 2 is a side view of a front part of the tractor bonnet of figure 1 b, and

Figures 3 and 4 are perspective views of the cooling arrangement of figure 2 in which the bonnet panels and chassis are removed, and

Figure 5 shows a cross section along line X-X of figure 4 which shows the cooling arrangement, and

Figure 6 shows a detailed view of the front of the vehicle of figure 4.

Figure 1 is a side view of an agricultural tractor 1 having a front bonnet 2 which houses an engine and a cooling arrangement (not seen) in accordance with the invention. The bonnet 2 extends from a driver's cab 1 a to the front of the tractor. A grill or mesh 3 is positioned at the front of the bonnet through which air passes and enters the cooling arrangement shown in figures 2, 3 and 4. The tractor has a longitudinal axis extending along the length of the tractor passing through the mid points of a front and rear axle positioned transverse to the longitudinal axis. The arrow indicates the forward direction of travel.

Figure 1 a is a perspective view of the bonnet of figure 1 . The bonnet 2 comprises a hood 2a and two opposing side parts 2b. When the bonnet 2 is closed as shown in figures 1 and 1 a, the hood 2a has a fairly flat upper surface which extends in a generally horizontal manner from the cab. Towards the front of the vehicle, the upper surface of the hood 2a starts to slope downwards and has an almost vertical front part at the front of the tractor. The hood 2a has an overhang which extends a small vertical distance along each of the two long opposing side edges. Each side of the bonnet 2 is formed from a side part 2b and the overhang of hood 2a. The front part of the hood 2a and a part of the upper surface of the hood is provided with the grill or mesh 3. Figure 1 b is a side view of the bonnet 2 with the hood 2a in an open position. The hood 2a may be lifted to give access to the parts under it by pivoting it about a pivot axis located close to the cab 1 a. When the hood 2a is lifted, it moves away from the side parts 2b. The larger the tractor, the higher is the front of the hood when pivoted open. In the open position, the hood is often too high for person to reach and then apply the necessary force to pivot it down to close it. The bonnet hood may be provided with a retractable belt 18 which extends between a spring mounted roller and an attaching means. Either one of the roller or attaching means is positioned on the hood 2a with the other part, attaching means or roller being positioned on the tractor, for example the chassis. When the hood 2a is open the belt extends vertically from the hood 2a to the chassis. To close the hood, the driver simply pulls a mid portion of the belt towards him or her which causes the hood to pivot downwards. As the hood 2a is closed, the belt retracts in length by the roller rolling the belt under tension from the roller spring.

As shown in figure 6, the front of the hood is provided with a locking means 50 for securing the hood to a front part of the tractor in a closed position. Additionally, or alternatively for easy closure of the hood and to prevent damage to the hood, guidance means is provided comprising two rollers 52 and two tracks 53. In figure 6, the hood is provided with two rollers 52 either side of the locking means 50. Tracks 53 extend in a substantially upright manner from a front part of the tractor which enables the rollers 52 to roll between the tracks 53 and guide the locking means 50 to the front of the tractor for engagement as the hood is lowered.

Each side part 2b comprises moveable side panels 6a, 6b and 6c (in which a grill may be integrated). Side panels 6a are located towards the front of the tractor and extend approximately from a fan 5 to radiators 6 as shown in figure 3. If more than one radiator 6 is fitted, the radiators are usually mounted in a series becoming increasingly closer towards the engine. Panels 6b and 6c are located to the rear of the bonnet and cover the engine. Moveable side panels 6a and 6b are pivotally attached to each side part 2b so that they can be moved with respect to the side parts to give access to components of the cooling system and/or engine system under the bonnet. The pivoting means may comprise spring means. Alternatively, side panels 6a and 6b may be fully, or partly removable from the side parts 2b to give access.

The edges of the panels 6a and 6b or the edges of the side parts 2b into which panels 6a and 6b fit are provided with a sealing means such as a rubber tubing 14 (Fig. 2) to prevent the escape of air to the atmosphere.

If side panel 6a is removable, it is attached to side part 2b by clamps and hooks at the locations marked E in figures 1 a and 1 b. To enable the side panels 6a to be easily removed, a hand grip 17 can be provided on the side panels 6a which allows a person to easily get a grip of the panels.

Figure 2 is a side view of a front part of the bonnet 2 in which the side panel 6a has been omitted so that the cooling arrangement inside the bonnet can be seen. A mounting plate 4 is provided which extends from under the fan 5 which is positioned at the front of the tractor behind the grill 3 to under the radiator or radiators 6 which are positioned in front of the engine (not shown) with respect to the forward direction of travel of the tractor. The tractor is provided with two parallel frames 7 which form the chassis. The mounting plate 4 extends widthways across both frames 7 and is provided with a fan mounting surface 8 and radiator mounting surfaces 9. The side profile of the mounting plate 4 is that of a laterally extended Z in that the fan mounting surface 8 and radiator mounting surfaces 9 are generally horizontal and are connected by a sloping surface 13 such that the fan mounting surface is elevated with respect to the radiator mounting surfaces. Since the frames 7 are horizontal, a support element 10 fixes the front of the plate 4 under the fan mounting surface 8 to the frames 7. The support element 10 is affixed to the frames 7 by bolts. The radiator mounting surface 9 of the plate is secured directly to the frames 7 by bolt means. On the underside of the plate 4 at the area of the fan mounting surface 8, attachment means are provided for attaching a light or heater core thereto. In, or on the plate 4 at the area of the radiator mounting surface 9, bore holes and/or channels are provided for receiving pipes from the radiator or radiators 6 and/or delivering liquid to the radiator or radiators 6.

Two air flows are indicated by arrows A and B. Air Arrow A shows an air flow for an air intake for the combustion of the engine and arrow B for cooling the radiators 6 and the engine. The fan 5 pushes air through the radiators 6 and the engine.

Figures 3 and 4 are perspective views of the cooling arrangement 1 1 in which the chassis and bonnet have been omitted. The difference between figure 3 and 4 is that in figure 4 an extended fan shroud 12 is shown. As shown in figures 3 and 4 fan 5 is mounted on mounting plate 4 so that it is tilted towards the radiators 6. Fan 5 is secured to the fan mounting surface 8 by fan attachment means extending through bores in the plate 4. Radiators 6 are attached in series to plate 4 by bolt means. The radiators 6 are in a spaced arrangement from the fan 5 with the fan mounting surface 8 at one end of the sloping surface 13 and the radiator mounting surfaces 9 at the other end.

The extended fan shroud is assembled from a number of parts bolted together.

Preferably, the extended shroud comprises at least three or four parts. In figure 4 the extended fan shroud 12 is shown having a lower part 12a which extends from the bottom half of a fan ring 12c in a forward direction with respect to the forward direction of travel of the tractor and an upper part 12b which extends rearwards from the upper half of the fan ring 12c towards the radiators 6 over plate 4. The upper part 12b is formed by two side parts 12d (only one is shown in figure 4) and a central part 12e. Side parts 12d may therefore be connected to either side of central part 12e to from an upper part 12b. Alternatively, central part 12e could itself comprise two half parts, each of which is connected to a side part 12e to form the upper part 12b.

A flange 15 is provided with sealing means 16. The flange 15 extends from a lower part of the fan shroud 12a diagonally along opposing sides of the upper part 12b and across parts 12b and 12d of upper part 12b. Preferably the bonnet 2 may be provided with sealing means 16. Sealing means 16 may, for example comprise rubber tubing.

In Figure 5 the cooling arrangement 1 1 is shown. The cooling arrangement shown comprises a fan 5 and radiators 6 in which the radiators are located downstream of the fan. It is envisaged that the fan 5 and the radiators 6 could be arranged the other way around so that the radiators are mounted upstream of the fan. In such an arrangement, the radiators are mounted in front of the fan with respect to the forward direction of travel.

When the bonnet 2 is closed and in contact with the sealing means 16 two air compartments are defined. A first air compartment C and a second air compartment D. First air compartment C is partially positioned above cooling fan 5, between the grill 3 of hood 2a and extended fan shroud 12.

Compartment C is a low pressure area. The dotted line in Figure 2 and 4 represents the grill 3 of the bonnet 2 when closed. With reference to figure 1 a in which the bonnet is closed, grill 3 is formed in the hood 2a so that it has a vertical, or generally vertical part 3a and a generally horizontal part 3b. Grill part 3b extends from grill part 3a towards the rear of the vehicle past fan 5.

Second air compartment D is positioned downstream of the fan 5 and as shown herein is located behind the radiators 6. Compartment D is a high pressure area and is enclosed by the hood 2a, the flange 15 and bonnet side panels 6b, 6c. Air which passes through the radiators 6 enters compartment D and then flows out to the atmosphere through a grill mounted in panel 6c, or through the frames 7.

By compartment it is meant a partially or fully enclosed area in which a surface which fully or partially encloses the area may, or may not be airtight.

When the bonnet 2 is closed and sealed, the panels 6a form an extension of the fan shroud between lower part 12a and upper part 12b so that air is channelled between the upper part 12b, side panels 6a and mounting plate 4 to the radiator 6. As a result, a complete fan shroud which extends from the fan to the radiator is formed from the upper part 12b, side panels 6a and plate 4. Thereby the mounting plate 4 guides air directly to the radiators 6.

When the bonnet 2 is closed and the sealing means 16 contacts the bonnet 2 (or flange) two air compartments C and D are defined.