AIR GUIDE IN VEHICLE ENGINE BAY

Abstract

An air guide is disclosed for a bonnet-covered engine bay of a goods vehicles, in particular agricultural tractors, where under the bonnet are located a combustion engine (1), components under high thermal load and low thermal load, and a fan which generates an air flow which is directed through air guide ducts past the combustion engine into the open. As the air flow from the fan heats up greatly on the combustion engine, there is a risk of a deterioration in the functioning of heat-sensitive components exposed to the air flow. To eliminate this risk, on both sides of the combustion engine (1) in the area of the components (4, 5, 6, 7) under high thermal load, between the combustion engine (1) and a side part (3) of the bonnet in a plane lying substantially parallel to the side part of the bonnet or combustion engine (1), is arranged an air guide element (11) which divides the air flow from the fan into an air flow (12) between the engine and the guide element (11) over the components (4, 5, 6, 7) under high thermal load and at least one air flow (13,14) between the guide element (11) and the side part (3) of the bonnet over the components (8, 9) under low thermal load.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

One embodiment of the invention is described by way of example only with reference to the accompanying drawings in which:

FIG. 1 shows the left-hand side in relation to the travel direction of a bonnet-covered engine bay of an agricultural tractor,

FIG. 2 shows a side view of the engine bay according to FIG. 1 without bonnet,

FIG. 3 is a perspective view of the engine bay according to FIG. 2, and

FIG. 4 is a view of the engine bay in the direction of the arrow 10 in FIG. 1.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Although the air guide according to the invention shown in the figures is arranged on the left-hand side of the engine bay viewed in the direction of travel and described accordingly, the invention is implemented similarly also on the right-hand side of the bonnet.

The drawings show a combustion engine 1 having a crankcase 2. The combustion engine 1 is surrounded by a bonnet of which however in FIG. 1 only the left-hand side part 3 is shown. This is made from a plastics materials with low thermal resistance and at the level of the engine 1 has a number of horizontal slots 3a.

Inside the engine bay formed by the bonnet are located components under high thermal load such as the exhaust turbocharger 4, the supply pipe 5 to the silencer 6 and the exhaust gas recycler 7. Furthermore, also arranged there are components under low thermal load close to the engine, such as the starter 8 and an electronics box 9.

A fan, not shown, that is arranged on the left in front of the engine 1 in FIGS. 1 and 2, generates an air flow directed in the direction of the arrow 10 which splits in front of the engine 1 into an air flow guided to the left and one guided to the right between the engine 1 and the side part 3 of the bonnet.

In order to make optimum use of the air flow on the left-hand side of the engine 1 to cool the components below the bonnet, between the engine 1 and the side part 3, a special air guide element 11 is provided. This guide is approximately parallel to the side part 3 of the bonnet and acts as a shield being made from a material with poor heat conductance but good heat resistance. This guide element allows the construction of several air guide ducts.

A first air guide duct 12 is formed close to the engine between the air guide element 11 and the engine 1 and guides the air flowing through it with cooling effect over the components 4, 5, 6, 7 under high thermal load and then, still greatly heated, downward into the open. A second 13 and a third 14 air guide duct remote from the engine are created between the air guide element 11 and the side part 3 of the bonnet. The second air guide duct 13 guides an air flow to a chamber 15, which houses the electronics box 9 or other electronic components under low thermal load, and then into the open. Since before entering the second air guide duct 13, this air flow has no opportunity to become heated from the components under high thermal load, and after entering the air guide duct 13 is insulated by the air guide element 11 from the components under high thermal load, the electronics box 9 and also the side part 3 are cooled effectively with relatively cold air.

The third air guide duct 14 guides an air flow, the temperature of which is relatively low like that of the air flowing through the second air guide duct 13, to the starter 8 where part of this air flow escapes through the slots 3a in the side part 3. The slots 3a are dimensioned here such that sufficient air is supplied to the starter 8 and the adjacent area of the side part 3 to cool both components sufficiently. As the two air guide ducts 13, 14 have very different pressure losses, they are separated from each other by a wall 16. This ensures that both the electronics box 9 and the starter 8 are exposed to an adequate air flow.

LEGEND

• • 1 Combustion engine
  • 2 Crankcase
  • 3 Side part (of bonnet)
  • 3 a Slots
  • 4 Exhaust turbocharger
  • 5 Supply pipe to silencer
  • 6 Silencer
  • 7 Exhaust gas recycling
  • 8 Starter
  • 9 E-box
  • 10 Arrow
  • 11 Air guide element
  • 12 Air guide duct on engine side
  • 13 Air guide duct on bonnet side for E-box
  • 14 Air guide duct on bonnet side for starter
  • 15 Housing for E-box
  • 16 Wall

Claims

1. An air guide for a bonnet-covered engine bay of a goods vehicles, in particular agricultural tractors, where under the bonnet are located a combustion engine, components under high thermal load and low thermal load, and a fan which generates an air flow which is guided through air ducts past the combustion engine into the open, wherein on both sides of the combustion engine in the area of the components under high thermal load, between the combustion engine and a side part of the bonnet, in a plane lying substantially parallel to the side part of the bonnet or the combustion engine is arranged an air guide element which divides the air flow from the fan into an air flow between the engine and guide element over the components under high thermal load and at least one air flow between the guide element and the side part of the bonnet over components under low thermal load.

2. An air guide according to claim 1, in which the air guide element forms two air guide ducts on the bonnet of the air guide element, a first air guide duct which supplies an air flow to a first component under low thermal load close to the engine and which opens downwards into the open in a rear section of the engine bay, and a second air guide duct which takes an air flow to cool a second component close to the engine and under low thermal load and which opens in the rear section of the engine bay into the open.

3. An air guide according to claim 1 in which that the air guide element is a heat-resistant shield panel.

4. An air guide according to claim 1 in which that the air flow close to the engine is directed downwards into the open in the rear section of the engine.