WO2009142555A1

WO2009142555A1 - Ventilating system for ventilating an engine space in vehicle, a vehicle comprising the ventilating system and a work machine comprising the ventilating system

Info

Publication number: WO2009142555A1
Application number: PCT/SE2008/000351
Authority: WO
Inventors: Per GJÖRNBERG; Mats Visti
Original assignee: Volvo Construction Equipment Ab
Priority date: 2008-05-23
Filing date: 2008-05-23
Publication date: 2009-11-26

Abstract

The present invention relates to a ventilating system for ventilating an engine space in a vehicle (1), the system comprising an enclosure (10) with walls (11), which encloses the engine space (18), at least one inlet (20) for entrance of air into the engine space (18), at least one outlet (23) for exit of air from the engine space (18) and a fan (16) being positioned outside the enclosure (10) and in fluid communication with the outlet (23) for providing a ventilating air flow (27) in the engine space (18) from said at least one inlet (20) to said at least one outlet (23) when the fan (16) is operated

Description

Ventilating system for ventilating an engine space in vehicle, a vehicle comprising the ventilating system and a work machine comprising the ventilating system

TECHNICAL FIELD

The present invention relates to a ventilating system for ventilating an engine space in a vehicle. The invention is further directed to a vehicle comprising the engine space. The invention is particularly directed to a work machine comprising the engine space.

The invention will below be described for a work machine in the form of a wheel loader. This should however be regarded as a non-limiting example, wherein the invention may be realized in other types of work machines, such as in an articulated hauler and in vehicles like a truck. Further terms frequently used for work machines are "earth-moving machinery", "off-road work machines", "construction equipment" and "forest machines".

A wheel loader is used for many different applications, such as in connection with road or tunnel building, sand pits, mines, forestry and similar environments. Especially, the wheel loader may be operated in dusty environments such as with carbon, chips, corn or grain, feedstuff etc where dust enters the engine space. For safety reasons, it is important to ventilate the engine space properly.

BACKGROUND ART

Noise has been a problem for vehicles for a long time. Due to this reason, noise standards for reduced external noise emissions have been implemented. In order to fulfil these requirements, manufacturers have to isolate noise emitters such as the combustion engine. Among other solutions, this is solved by insulating the engine enclosing. The enclosure is normally noise insulated by creating an encapsulated enclosing. This is made by introducing encapsulating walls and noise absorbing sheets. The walls are positioned to cover at least some of the openings in the enclosing, which earlier exposed the engine space to the surrounding. Covering these openings effectively reduced external noise emissions from the engine space enclosed by the enclosure, in which space the engine is positioned.

A radiator and a fan have traditionally been positioned in the engine space, wherein an air stream flows from the fan to the radiator. This stream then passes through the engine space and through the openings in the enclosing into the surrounding. Through these openings of the compartment enclosing, noise also escapes. Since an air stream carries noise from the engine space, the air passing through the open areas increases the noise emissions.

Implementing an insulated enclosing results in that the cooling fan and the radiator has been moved out from the engine space. This results in an improved cooling effect by the radiator, since the heat from the engine is no longer exposed to the radiator. Moreover, the air stream generated by the fan and used for the heat exchange of the radiator, no longer passes through the engine space. This results in that the engine is not exposed to the heated air stream.

With the encapsulated engine space, the noise emissions are significantly reduced. However, exhaust emission standards contributes to an increased engine space temperature, due to an increased combustion temperature and exhaust temperature. Extra catalysts may also be needed, which further increases the space temperature.

Due to the enclosed engine space, dust pushed into the engine space when the wheel loader is operated in a dusty environment, such as dust from carbon, chips or grain, stays in the space. The dust could explode when ignited by heat or sparks. It may also block or reduce the lifetime of components in the engine space. Moreover, fuel vapour caused by fuel leakage is kept in the enclosed engine space. This vapour may cause dangerous incidents such as explosions when ignited by heat in the space.

Consequently, the enclosing of the engine space and the removal of the air stream from the cooling fan, creates a number of disadvantages such as safety problems, reduced lifetime of components such as the generator, electric components, fuel tubes, hydraulic tubes and plastic parts in the space.

In order to deal with these disadvantages, it is desired to improve ventilation of the engine space in order to remove some of the dust and vapour and decrease the temperature in the space.

There are several ways to increase ventilation of the engine space. One common solution is to use an ejector function placed in the exhaust pipe. The speed of the exhausts creates an ejector effect which ventilates the engine space. However, ventilation effect is very low and normally only gives effect when the engine is operated with maximum speed.

Another solution is to mount electric or hydraulic fans in the engine space, which ventilates the space either by pushing in air or suck out air. Disadvantages with such fans is that they require space, contributes to the noise emissions and requires extra components/cables (which may fail), which increases the costs.

US 6,523,520 proposes an engine space cooling system with a remotely positioned radiator and fan. It is directed to the problem that certain regions of the engine space (exhaust manifolds, turbochargers) become excessively hot. The problem is solved by using containments members, positioned on these particular, targeted regions. A conduit is placed in fluid communication with the containment member at one end. The conduit is placed in fuel communication with the fan with the other end. The rotation of the fan causes air to flow from the containment via the conduit into the surrounding. The benefit is that the regions are effectively cooled. However, the solution is not sufficient when creating a ventilation of the engine space.

SUMMARY OF THE INVENTION

The object of the present invention is therefore to create an improved ventilation system in a vehicle for ventilating an encapsulated engine space.

The object is solved by means of a ventilating system according to claim 1. Thus, it is solved by a ventilating system for ventilating an engine space in a vehicle, the system comprising an enclosure with walls, which encloses the engine space, at least one inlet for entrance of air from outside the engine space into the engine space, at least one outlet for exit of air from the engine space and a fan being positioned outside the enclosure and in fluid communication with the outlet for providing a ventilating air flow in the engine space from said at least one inlet to said at least one outlet when the fan is operated.

Thus, ambient air enters the inlet(s) during operation. More specifically, the enclosure is configured so that ambient air directly enters the engine space via the inlet(s). Further, in operation, the ventilation air passes an engine provided in the engine space on the way between the inlet(s) and the outlet(s).

One advantage with the present invention is that no extra electric components, such as a ventilating fan and cables, are needed. Moreover, the total heat durability of the vehicle is not affected by the present invention. The durability of the components of the vehicle can be increased.

Further, no special arrangement of containment members within the engine space is neither required nor preferred. Instead, presence of such containment members would obstruct the ventilating flow. Therefore, the enclosure is preferably designed such that the ventilating air flow is substantially unobstructed between the inlet(s) and regions for hot parts in the engine space and between said regions and the outlet(s). Thus, the enclosure is preferably free of any additional interior members, walls or similar that would obstruct the ventilating flow. The enclosure walls are preferably of the single wall-type.

A good ventilation effect is achieved as soon as the engine is started. Another advantage is that ventilation increases if the cooling need increases. The reason is that the speed of a cooling engine is dependent on the cooling need of the engine. Furthermore, if a radiator (which is normally provided in association with the fan) gets clogged, the pressure in a low pressure space between the fan and the radiator decreases, which results in that ventilation increases.

With the present invention, the engine space becomes cleaner, with less dust, dirt and fuel vapour remaining in the space, wherein the security of the vehicle is improved.

Using a common engine enclosing means that no special arrangements are needed in order to introduce the concept of the invention into a vehicle. The invention creates conditions for a ventilating air flow through substantially the whole engine space. Moreover, the exhaust ejector earlier used to provide a ventilating air flow can be removed.

According to a preferred embodiment, at least one inlet and at least one outlet are positioned on opposite sides of the engine space. Especially, the inlet and the outlet are positioned on diagonally opposite sides of the engine space. In this way, the ventilating air flows through at least a substantial part of the engine space and an efficient ventilation is thereby achieved.

According to a further preferred embodiment, the system comprises a plurality of inlets for providing a plurality of ventilating air flow paths through the engine space. In this way, a further improved ventilating effect is achieved. Preferably, at least one inlet is located in a lower part of the enclosure. More specifically, at least one inlet is located in an underside of the enclosure and/or in a side wall of the enclosure. The term "side wall" embraces not only lateral walls of the engine enclosure, but also a front and rear wall with regard to a position of the enclosure relative to a longitudinal direction of the vehicle.

According to a further preferred embodiment, at least one inlet is formed by an elongated opening between two adjacent sheets forming the enclosure walls. Further, at least one inlet may be formed by an opening defined between a wheel axle and an adjacent sheet forming the enclosure walls. Thus, no special arrangements need to be provided for entrance of air into the engine space. Instead, openings which are normally provided in the enclosure due to design and assemblying methods etc are used in the ventilating system.

According to a further preferred embodiment, at least one outlet is arranged in an upper part of the enclosure. Due to the fact that the inlets defined above are normally arranged in a lower part of the enclosure, a ventilating air flow through substantially the whole engine compartment may be achieved in this way. In addition, at least one outlet may be arranged in a lower part of the enclosure. Further, at least one outlet may be arranged in a side wall of the enclosure.

According to a further preferred embodiment, at least one outlet forms a port. The term "port" is defined as a specially configured hole arrangement through the engine space wall for exit of the ventilating air. For example, such a port may comprise a circular hole and be provided through a sheet defining one of said engine space walls.

According to a further development of the last-mentioned embodiment, the system further comprising at least one conduit with a first end connected to the outlet port and a second end in fluid communication with the fan. Thus, the conduit ends at the enclosure wall. According to a further preferred embodiment, the system comprises a cooling package being positioned outside the enclosure, the package comprising said fan and a radiator with a low pressure space formed therebetween, wherein the fan is arranged to create, when operated, a pressure in the low pressure space which is lower than the pressure in the engine space. Preferably, the second end of the conduit is then in fluid communication with the low pressure space. Further, the radiator and the fan are arranged in a series relationship, wherein the radiator may be located closer to the enclosure than the fan. Alternatively, the fan is located closer to the enclosure than the radiator.

Further advantages will appear for the embodiments in the detailed description.

BRIEF DESCRIPTION OF DRAWINGS

In the following text the invention will be described in detail with reference to the attached drawings. These drawings are used for illustration only and do not in any way limit the scope of the invention:

Figure 1 shows a side view of a vehicle in form of a wheel loader in which the ventilation system according to the present invention can be implemented.

Figure 2 shows a schematic side view of the ventilation system according to a first embodiment of the present invention.

Figure 3 shows a schematic top view of the ventilation system according figure 2.

Figure 4 shows a schematic side view of the ventilation system according to a second embodiment of the present invention.

Figure 5 shows a perspective view of the vehicle according to figure 1 with the encasing being enclosed. Figure 6 shows a perspective view from the bottom of the vehicle according to figure 5.

Figure 7 shows a perspective view of the vehicle according to figure 5 with the encasing being partly opened.

Figure 8 shows a perspective view of the engine space and the ventilation system of the vehicle according to figure 5 and according to the first embodiment of the present invention.

Figure 9 shows a perspective view of the engine space and the ventilation system according to figure 8.

Figure 10 shows a perspective view of the engine space and the ventilation system of the vehicle according to figure 5 and according to the second embodiment of the present invention.

DETAILED DESCRIPTION

The invention will now be described in detail with reference to embodiments described in the detailed description and shown in the drawings. The embodiments of the invention with further developments described in the following are to be regarded only as examples and are in no way to limit the scope of the protection provided by the patent claims.

Figure 1 shows a vehicle 1 in the form of a wheel loader. The body of the working machine 1 comprises a front body section 2 and a rear body section 3. The rear body section 3 comprises a cab 4. The body sections 2,3 are connected to each other in such a way that they can pivot. The working machine 1 comprises equipment 9 for handling objects or material. The equipment 9 comprises a load-arm unit 6 and an implement 7 in the form of a bucket (or fork or log grapple) fitted on the load-arm unit. A first end of the load-arm unit 6 is pivotally connected to the front machine section 2. The implement 7 is connected to a second end of the load-arm unit 6. The rear body section 3 of the vehicle holds an engine 12, a transmission 13 and a hydraulic pump 14, see figure 2 - 10. It further holds a cooling package with a fan 16 and a radiator 17 and other components such as an electric generator 15. The vehicle comprises an enclosure 10 with walls 11 , which encloses an engine space 18 in which an engine and a plurality of components are positioned, a plurality of inlets 20 in the enclosure 10 providing a connection between the engine space 18 and the air 19 outside the enclosure.

The invention relates to a ventilation system, which comprises the cooling package 21 being positioned outside the enclosure 10. A low pressure space is formed between the fan 16 and the radiator 17 . When the fan is operated, it is arranged to create a pressure in the low pressure space 22 which is lower than the pressure in the engine space 18.

The ventilation system comprises at least one outlet port 23 being arranged in the enclosure wall 11 , see figure 2 - 4. The system further comprises at least one conduit 24 with a first end 25 that is in fluid communication with the engine space 18 via the outlet port 23 arranged in the enclosure wall 11 , a second end 26 of the conduit 24 being is fluid communication with the low pressure space 22. The conduit enables an air flow 27 from the plurality of inlets 20, via the engine space 18 and the outlet port 23 arranged in the enclosure wall 11 to the low pressure space 22 when the fan 16 is operated.

The main advantage with the ventilation system according to the present invention is that no extra electric components, such as a ventilating fan and cables, are needed. Moreover, the total heat durability of the vehicle 1 is not affected by the present invention. The durability of the components of the vehicle can be increased. A good ventilation effect is achieved as soon as the engine 12 is started and it provides a ventilating air flow through the whole engine space 18. In order to create a ventilating flow through the engine space 18, a plurality of inlets 20 are preferably provided in the enclosure wall(s) 11. Such inlets may be located in the underside of the enclosure or on the side of the enclosure 10. This means that air flow is from different directions into the space, which will ensure that a major part of the engine space is exposed to the ventilating flow.

At least one of the inlets may consist in an opening between the enclosure walls 11. This means that the enclosure 10 by nature is not completely sealed. One reason is that the steel plates are not welded or mounted. Elongated, slot-like openings are therefore formed between the plates, which forms the inlets 20 into the engine space 18.

At least one outlet port 23 is arranged in the upper part of the enclosure 10. This gives the advantage that the air entering the engine space 18 from the inlets 20 in the underside and/or side of the enclosure 10 will flow through a substantial part of the engine space 18. This will ensure a proper ventilation. Moreover, since the air is heated and therefore rises, an outlet port arranged in the upper part will improve the ventilating flow 27.

At least one outlet port 23 may be arranged in the lower part of the enclosure 10, see figure 2. By making up with an addition port in the lower part of the enclosure, it is ensured that also this part of the engine space 18 is ventilated properly.

Outlet ports could be located wherever there is a need to ventilate a part of the engine space 18. For instance, by locating at least one outlet port in the vicinity of a component, the ventilation around this particular component is further improved, with the beneficial effect of improved cooling in that area.

Having different location of inlets means that the air flow 27 is directed via a plurality of paths, see figure 2, from the inlets 20 and through the engine space 18 to the outlet port 23 in the enclosure. Also, having different location of the outlet ports 23, means an increased number of paths through the engine space 18. As shown in figure 2 there can be a number of different paths for the ventilating air flow, which is beneficial for the ventilation of the engine space.

Figure 3 and 4 shows two different embodiments for the cooling package 21 in the ventilating system. Both figures illustrate the ventilating system in a top view. The embodiment of figure 3 is also illustrated in figure 2. In this embodiment, the fan 16 is located closer to the enclosure 10 than the radiator 17. In the alternative embodiment, see figure 4, the radiator 17 is located closer to the enclosure 10 than the fan 16. In both embodiments, the outlet ports 23 are arranged on the enclosure wall 11 facing the cooling package 21. In the second embodiment, the conduits 24 are guided around the radiator 17 to the low pressure space 22.

A vehicle comprising the ventilating system according to figure 2 - 4 will now be described with reference to figures 5 - 10. Figure 5 shows a perspective view of the vehicle according to figure 1 with the encasing being enclosed. Figure 6 shows a perspective view from the bottom of the vehicle according to figure 5. Both these figures intend to illustrate the inlets 20 into the engine space 18. The vehicle comprises the enclosure 10 with walls 11 , which encloses an engine space in which the engine 12 and a plurality of components 13,14,15 are positioned. The cooling package 21 is positioned outside the enclosure 10. The package comprises the fan 16 and the radiator (not shown) with a low pressure space (not shown) formed there between. When the fan is operated, the airflow 27 is generated.

The plurality of inlets 20 in the enclosure 10 provides a connection between the engine space 18 and the air 19 outside the enclosure. There are inlets in the bottom, around the wheel axle and in the back under the cab 4. When the flow is generated, the air flows 27 in through the plurality of inlets 20 into the engine space. The air for instance passes in through the inlets around the axle, see figure 6, into the engine space 18. This means that air flows in from different directions into the engine space 18. This will ensure that a major part of the engine space is exposed to the ventilating flow.

The fact that the vehicle comprises a plurality of inlets having different locations ensures an efficient ventilating flow through substantially the whole engine space 18. More specifically, a plurality of flow paths from a plurality of inlets ensures an efficient ventilation of the whole engine space, see figure 2,.

Figure 7 shows a perspective view of the vehicle according to figure 5 with the enclosure 10 being partly opened. Here it is shown how the air stream 27 flows from the plurality of inlets 20, via the engine space 18 and the outlet port 23 arranged in the enclosure wall 11 to the low pressure space 22, when the fan 16 is operated. A number of paths are shown in figure 7.

Figure 8 shows a perspective view of the engine space and the ventilation system of the vehicle according to figure 5 and according to the first embodiment of the present invention. Figure 9 shows a perspective view from the other side of the engine space with the ventilation system according to figure 8. As illustrated, the different paths of the air flows 27 ensure that different areas around the engine 12 are ventilated. With the . different air flows, areas around the components, such as the electric generator 15 and the transmission 13 are also ventilated.

Two outlet ports 23 are arranged in the upper part of the enclosure 10. As mentioned in relation to figure 2, this gives the advantage that the air entering the engine space 18 from the inlets 20 in the underside and/or side of the enclosure 10, will flow through a large part of the engine space 18. Since the air is heated and therefore rises, an outlet port arranged in the upper part will improve the ventilating flow 27. A conduit 24 is also arranged in the lower part of the enclosure. With this additional outlet port in the lower part of the enclosure, it is ensured that also this part of the engine space 18 is ventilated properly. Outlet ports 23 are with advantage located wherever there is a need to ventilate a part of the engine space 18. As mentioned in relation to figure 2, by locating at least one outlet port in the vicinity of a component the ventilation around, the ventilation of the area around this particular component is further improved (with the beneficial effect of improved cooling in that area).

Figures 9 and 10 shows perspective views of the engine space and the ventilation system of the vehicle according to figure 5 (according to the first and second embodiments of the present invention). In figure 9, the first embodiment, the fan 16 is located closer to the enclosure than the radiator, (not shown). In the second embodiment, see figure 10, the radiator 17 is located closer to the enclosure 10 than the fan 16. In both embodiments, the outlet ports 23 are arranged on the enclosure wall 11 facing the cooling package. In the second embodiment, the conduits are guided around the radiator 17 to the low pressure space 22.

Claims

1. Ventilating system for ventilating an engine space in a vehicle (1), the system comprising an enclosure (10) with walls (11), which encloses the engine space (18), at least one inlet (20) for entrance of air from outside the engine space (18) into the engine space (18), at least one outlet (23) for exit of air from the engine space (18) and a fan (16) being positioned outside the enclosure (10) and in fluid communication with the outlet (23) for providing a ventilating air flow (27) in the engine space (18) from said at least one inlet (20) to said at least one outlet (23) when the fan (16) is operated.

2. A ventilating system according to claim 1 , wherein at least one inlet (20) and at least one outlet (23) are positioned on opposite sides of the engine space.

3. A ventilating system according to claim 1 or 2, wherein at least one inlet (20) and at least one outlet (23) are positioned on diagonally opposite sides of the engine space.

4. A ventilating system according to any preceding claim, wherein the system comprises a plurality of inlets (20) for providing a plurality of ventilating air flow paths through the engine space.

5. A ventilating system according to any preceding claim, wherein at least one inlet (20) is located in a lower part of the enclosure (10).

6. A ventilating system according to any preceding claim, wherein at least one inlet (20) is located in an underside of the enclosure (10).

7. A ventilating system according to any preceding claim, wherein at least one inlet (20) is located in a side wall of the enclosure (10).

8. A ventilating system according to any preceding claim, wherein at least one inlet (20) is formed by an elongated opening between two adjacent sheets forming the enclosure walls (11).

9. A ventilating system according to any preceding claim, wherein at least one inlet (20) is formed by an opening defined between a wheel axle and an adjacent sheet forming the enclosure walls (11).

10. A ventilating system according to any preceding claim, wherein at least one outlet (23) is arranged in an upper part of the enclosure (10).

11. A ventilating system according to any preceding claim, wherein at least one outlet (23) is arranged in a lower part of the enclosure (10).

12. A ventilating system according to any preceding claim, wherein at least one outlet (23) is arranged in a side wall of the enclosure (10).

13. A ventilating system according to any preceding claim, wherein at least one outlet (23) forms a port.

14. A ventilating system according to claim 13, wherein the system further comprising at least one conduit (24) with a first end (25) connected to the outlet port (23) and a second end (26) in fluid communication with the fan.

15. A ventilating system according to any preceding claim, wherein the system comprising a cooling package (21) being positioned outside the enclosure (10), the package (21) comprising said fan (16) and a radiator (17) with a low pressure space (22) formed therebetween, wherein the fan (16) is arranged to create, when operated, a pressure in the low pressure space (22) which is lower than the pressure in the engine space (18).

16. A ventilating system according to claim 14 and 15, wherein the second end (26) of the conduit (24) being in fluid communication with the low pressure space (22).

17. A ventilating system according to claim 15 or 16, wherein the radiator (17) is located closer to the enclosure (10) than the fan (16).

18. A ventilating system according to claim 15 or 16, wherein the fan (16) is located closer to the enclosure (10) than the radiator (17).

19.. A ventilating system according to any preceding claim wherein at least one inlet (20) and/or outlet (23) is located in the vicinity of a part in the engine space, which is particulary heated during operation.

20. A vehicle comprising the ventilating system according to any preceding claim.

21. A work machine comprising the ventilating system according to any one of claims 1-19.