EP1682753A1

EP1682753A1 - Protecting device

Info

Publication number: EP1682753A1
Application number: EP04793867A
Authority: EP
Inventors: Lennart Nygren
Original assignee: Volvo Lastvagnar AB
Current assignee: Volvo Truck Corp
Priority date: 2003-10-27
Filing date: 2004-10-27
Publication date: 2006-07-26
Also published as: SE0302836D0; SE0302836L; CN100445521C; SE525987C2; WO2005042935A1; BRPI0415907A; CN1846042A; US20060196560A1

Abstract

A protecting device for a reservoir (2) disposed on a vehicle (1) and intended to contain a medium. The device comprises a means (5) disposed inside the reservoir (2), in the form of at least one solid body, for deterring relative movement, given the presence of said medium in frozen form in the reservoir (2), between said frozen medium and the reservoir during transport of the vehicle (1).

Description

Protecting device

THE FIELD OF THE INVENTION

The present invention relates to a protecting device according to the preamble to patent claim 1, a reservoir according to patent claim 22 and a vehicle according to patent claim 23.

BACKGROUND OF THE INVENTION

In various types of vehicle, there are reservoirs for liquids used for different functions of the vehicle. In certain cases, these liquids and reservoirs are used at temperatures which are so low that the liquid passes wholly or partially into frozen form. The present invention can be utilized for various reservoirs for vehicle applications, but the following description will discuss specifically, for illuminating but non- limiting purposes, how the invention can be used together with a reservoir intended for urea. There is a need to store urea in a reservoir disposed in a vehicle so as to be able to provide urea for cleaning of exhaust gases deriving from an internal combustion engine of the vehicle.

One way of meeting the increasingly strict requirements for cleaning of exhaust gases deriving from internal combustion engines is to convert the exhaust gases into safe or less harmful gases by injecting urea into the exhaust gases. This can reduce, above all, the nitrogen oxides NO_x content, which can help to reduce the emissions of harmful substances into the environment. To this end, there is a need, however, for a continuous supply of urea whilst the internal combustion engine is running, which means that a vehicle, such as, for example, a truck, which shall utilize the cleaning technology in question is equipped with a reservoir for urea. From the reservoir, urea can then be delivered for cleaning of the exhaust gases .

There are problems, however, associated with the use of urea. In cold weather, for example, urea can freeze in the reservoir. If urea freezes in the reservoir, it can mean, in turn, that the reservoir or other equipment disposed inside the reservoir, such as, for example, warming members for warming the urea, is damaged by the frozen matter through collision with the latter and/or through abrasion between the frozen matter and the reservoir and/or equipment disposed inside the reservoir. The problem is especially marked when the frozen matter re-thaws, since, as the frozen matter melts, loose lumps or blocks of frozen matter can be formed/released in the reservoir. Since the matter very often thaws from and into the matter, a large lump of frozen material ends up moving around in the reservoir when the matter thaws.

OBJECT OF THE INVENTION AMD SUMMARY OF THE INVENTION

One object of the invention is to provide a protecting device for reservoirs in vehicle applications, which device, in the use of a reservoir containing a medium in frozen form, is capable of deterring against damage to the reservoir or to equipment disposed inside the reservoir.

This object is achieved by means of a device according to patent claim 1. The fact that the device comprises a means disposed inside the reservoir, in the form of at least one solid body, for deterring relative movement, given the presence of said medium in frozen form in the reservoir, between said frozen medium and the reservoir during transport of the vehicle, means that damage to the reservoir, arising from the effect of frozen matter, can be considerably reduced. Further advantageous embodiments and other advantages of the invention derive from the following description and dependent patent claims .

BRIEF DESCRIPTION OF THE DRAWINGS

There follows below a more detailed description of exemplified embodiments of the invention with reference to the appended drawings, in which

fig. 1 is a perspective view illustrating a mechanism for cleaning exhaust gases deriving from an internal combustion engine by the admixture of a medium, which mechanism includes a device according to the invention for protecting a reservoir containing said medium,

fig. 2a illustrates a protecting means according to the invention which has grid sections,

fig. 2b illustrates a variant of a protecting means according to the invention which has a three- dimensional grid,

fig. 3a illustrates a further variant of a protecting means according to the invention which has a hollow structure,

fig. 3b illustrates a variant of the protecting means according to the invention in fig. 3a,

fig. 4 illustrates a further variant of a protecting means according to the invention having elongated elements,

fig. 5 illustrates a further variant of a protecting means according to the invention in the form of a resilient layer disposed on the inner side of the reservoir, and fig. 6 illustrates a further variant of a protecting means according to the invention in the form of a counter-stay disposed inside the reservoir.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION

Figure 1 illustrates in perspective view a mechanism for cleaning exhaust gases from an internal combustion engine (not shown) of a vehicle 1 by the admixture of a medium. A reservoir 2 for said medium, such as, for example, urea, is disposed on the vehicle so as to deliver said medium to a combined muffler and catalyzer 3 connected to the internal combustion engine. The reservoir 2, which expediently is fastened to the chassis 1 of an engine-driven vehicle, can also be provided with a member 4 for warming said first medium present in the reservoir. Such a warming member 4 can be used to thaw matter which has frozen in the reservoir 2. It should be pointed out that the reservoir 2 may, of course, be placed on a vehicle unit which does not have an engine. Where the protecting device according to the invention is utilized in connection with exhaust-gas cleaning, the reservoir 2 is disposed, however, on an engine-driven vehicle or on a vehicle unit which is linked with another vehicle unit provided with an engine.

The medium which is added for cleaning of the exhaust gases can have differing chemical composition. Said medium can be urea, for example, or a solution consisting of or containing urea (CO[NH₂]₂+H₂0) . Urea can be used to reduce the presence of nitrogen oxides NO_x in the exhaust gases deriving from the internal combustion engine of the vehicle.

The protecting device according to the invention comprises a means 5 disposed inside the reservoir 2, in the form of at least one solid body, for deterring relative movement, given the presence of said medium in frozen form in the reservoir 2, between said frozen medium and the reservoir 2 during transport of the vehicle 1.

In the embodiments illustrated in figures 2a, 2b, 3a, 3b and 4, said means 5 has at least one position 6, preferably a plurality of positions 6, for the freezing of said medium to said at least one position or to the positions 6. Said means 5, hereinafter referred to as the protecting means 5, can be, for example, a network or a grid 7 onto which said medium can freeze. In this way, freezing and/or thawing of the urea can be controlled, at the same time as the reservoir 2 can be protected against the effect of frozen matter in the reservoir 2. As a result of said medium being frozen to the protecting means 5, the frozen matter is deterred from colliding with the walls of the reservoir, which might otherwise occur owing to frozen matter in lump form swishing around in the non-frozen liquid in the reservoir 2 during displacement of the reservoir 2. When frozen matter in the reservoir 2 thaws, the protecting means 5 will probably also be able to cause this thawing to occur without sizeable loose lumps or blocks of frozen matter being released and adversely affecting the reservoir 2.

Figure 2a shows an embodiment in which a plurality of grid sections 7a, 7b, 7c, 7d are utilized to protect the reservoir. For the sake of clarity, every second grid section is illustrated diagrammatically with dash- dot lines. Depending on various conditions, such as, for example, the volume, shape, etc. of the reservoir 2, one or more grid sections 7a, 7b, 7c, 7d of different size and shape can be disposed within the volume of the reservoir 2 in order to create the protecting means 5. For example, a plurality of grid sections can be disposed essentially parallel to one another and at a mutual distance apart to produce the protecting means 5. The protecting means 5 can therefore be formed by means of one or more two- dimensional grids, but it can also be an integrated, three-dimensional grid or network structure 8 as illustrated in figure 2b. By two-dimensional and three- dimensional is here meant that the grid 7 has the openings disposed in one and the same plane 7b and disposed in at least two different planes 8, respectively. The reservoir 2 can be of any chosen shape and size and the protecting means 5 configured accordingly. The outer contour of the protecting means 5 can be matched to the inner limit surface of the reservoir so that the protecting means, even though it is disposed loose inside the reservoir, is essentially detained in its position by the walls of the reservoir. Alternatively, the protecting means 5 can be fastened in the reservoir 2 in order, in respect of at least one position, to fix the protecting means 5 in relation to the reservoir 2.

The protecting means 5 is advantageously configured such that and made of such a material having a flexibility such that, when the protecting means 5 is subjected to load as a result of the inertia of the matter frozen to the protecting means and the movement of the vehicle, the protecting means 5 can move in relation to the reservoir by flexing of the protecting means. In certain cases, the protecting means 5 can be made of a material with relatively high elasticity, and/or dimensioned, to allow this flexing in relation to the reservoir. The movement of one or more lumps which are frozen to the protecting means can thereby be gently and sensitively dampened, whilst unwelcome collisions between these lumps and the walls of the reservoir are prevented, or at least deterred, or only occur at a lower speed than would be the case without said protecting means . In figures 3a and 3b, variants of a protecting means 5 are illustrated. The protecting means 5 is a porous three-dimensional body 9, which has a large quantity of cavities 10 of the same or varying size. The cavities 10, which account for at least 50%, preferably more than 80%, and in most cases over 90%, mean that the protecting means 5, despite essentially filling the whole of the reservoir 2, see figure 3a, still does not occupy too great a volume of the reservoir, so that space remains for intended said medium. Such a structure 9 with cavities 10 or pores has an appearance similar to that exhibited by a sponge material. This protecting means 5, too, can have the characteristics which are described above for the network and grid constructions. In figure 3b, a member 4 for warming said medium in the reservoir 2 is also present, disposed in the lower part of the reservoir 2. In this case, a larger cavity, offering space for the warming member 4, can be disposed in the protecting means, or the extent of the protecting means 5 can be limited, as illustrated in figure 3b, to that part of the reservoir 2 which is without the warming member 4.

In figure 4, the protecting means 5 has a plurality of elongated elements 11 fastened in the upper end of the reservoir 2. One or more such elongated elements, such as, for example, rods 12 of different length and cross section, can be used for said medium to freeze to these rods. Preferably, the rods 12 are designed to extend into the reservoir 2 from an opening 13 in the reservoir 2 and, expediently, the rods 12 are suspended from a component 14 which is detachably disposed in the reservoir. The component 14 can be configured so that the opening 13 can be closed and opened by means of the component 14. This component 14 can be configured and have a flexibility such that the protecting means 5 can move in relation to the reservoir 2 by flexing of the suspension component 14 when the protecting means 5 is subjected to load as a result of transport of the vehicle. The component 14 preferably has an elasticity which is higher than that of the material of the protecting means 5, in this case the rods, so as to allow certain flexing, and thus movement, of the rods in relation to the reservoir 2. The movement of one or more lumps which are frozen to the protecting means 5 can thereby be dampened in the manner which is described above. Alternatively, or in combination with a flexible component 14 of this kind, the rods 12 per se can be configured and made of a material which allows the rods themselves to be able to spring, i.e. bend, to the point where the movement of the rods, and therefore the movement of matter frozen to the rods, will be able to be dampened and unwelcome collisions between frozen matter and the walls of the reservoir will be able to be avoided during transport of the vehicle. Although, in the illustrated embodiment, the opening for the elongated elements 11 is disposed in the upper part of the reservoir 2 , it could be disposed elsewhere in the reservoir. The protecting means in the form of elongated elements could also be arranged without special opening in the reservoir, by the fastening of rods, for example, on the inner side of the walls of the reservoir.

For all the above-described embodiments, the protecting means can be designed to deter displacement of said frozen medium from a first part-volume 19 of the reservoir 2 to a second part-volume 20 of the reservoir 2, see especially figures 3a and 3b. In particular, the protecting medium 5 can be designed to deter displacement of said frozen medium from a first part- volume 19 of the reservoir to a second part-volume 20 of the reservoir, which second part-volume contains a further member 4 disposed inside the reservoir 2. Such a member can be designed, for example, to warm said medium in the reservoir 2. Figure 5 shows a further embodiment of the protecting means 5 according to the invention in the form of a resilient layer 15 disposed along at least a part of the inner limit face 16 of the reservoir 2. Such a layer 15 expediently has a higher flexibility than the material in the walls 17 of the reservoir so as to act as a shock absorber between frozen matter present in the reservoir 2 and the bearing walls 17 of the reservoir. The resilient layer can be made, for example, of rubber or the like. Such a protecting means 5, apart from acting as a shock absorber, can also prevent abrasion on the walls of the reservoir. In addition, the thickness and deformability of the layer 15 can be matched to the expansion which said medium suffers in the reservoir as it freezes, so that, at least at a certain level of filling of said medium in the reservoir, the expansion upon freezing is wholly or partially compensated by the elastic deformation of the layer. The layer can hence help to hold the frozen matter still through pressurization of the frozen matter by the compressed layer.

Figure 6 illustrates a variant of a protecting means 5, which is based on the fact that one or more counter- stays 18 are disposed inside the reservoir 2 in order essentially to detain said frozen medium in a certain part or certain parts of the reservoir. Preferably, one or more such counter-stays 18 is/are disposed close to a wall 17 of the reservoir 2. It is also possible, as illustrated, to form the counter-stays 18 by a special configuration of the walls 17 of the reservoir. In such a case, said at least one solid body, i.e. the protecting means 5, is constituted by at least one component which, at the same time, constitutes part of a wall 17 of the reservoir 2. Whether said at least one counter-stay 18 is created by the configuration of a wall 17 of the reservoir 2 or by the placement of separate apparatus inside the reservoir, the counter- stay (s) 18 is/are designed to deter displacement of said frozen medium from a first part-volume 19b of the reservoir to a second part-volume 20b of the reservoir 2 and thereby essentially detain said frozen medium in a certain part of the reservoir, for example in the lower or upper part of the reservoir 2.

The protecting means 5 can be designed especially to deter displacement of said frozen medium from a first part-volume of the reservoir to a second part-volume of the reservoir, which second part-volume contains a further member disposed inside the reservoir in order to protect this member. In order to protect, for example, a warming member disposed inside the reservoir, it is possible, by means of the protecting means, essentially to detain frozen matter in a volume which does not comprise the warming member, but it might also be possible to utilize the protecting means to detain said frozen medium in the volume containing the further member in order instead to ensure that the matter frozen on this member does not adversely affect the member by moving, and hence pulling along the member and subjecting it to load.

It should be stressed that the invention is not limited to embodiments of the invention which are herein described, but is limited only by the following patent claims. Once the concept of the invention is known, a number of modifications within the scope of the invention will probably be evident to a person skilled in the art .

Claims

PATENT CLAIMS

1. A protecting device for a reservoir (2) disposed on a vehicle (1) and intended to contain a medium, characterized in that the device comprises a means (5) disposed inside the reservoir, in the form of at least one solid body, for deterring relative movement, given the presence of said medium in frozen form in the reservoir (2), between said frozen medium and the reservoir during transport of the vehicle (1) .

2. The protecting device as claimed in claim 1, characterized in that said means (5) has at least one position (6) for the freezing of said medium to said at least one position.

3. The protecting device as claimed in claim 1 or 2 , characterized in that said means (5) has a plurality of positions (6) for the freezing of said medium to these positions.

4. The protecting device as claimed in any preceding claim, characterized in that said means (5) comprises a grid (7, 8), network or the like.

5. The protecting device as claimed in any preceding claim, characterized in that said means (5) is a porous body (9) having a volume ratio V_h/V_tot greater than 0.5, in which V is equal to the combined volume of the cavities in the body and V_tot s the total volume constituting the sum of said cavities and the solid matter of the body.

6. The protecting device as claimed in any preceding claim, characterized in that said means (5) comprises at least one elongated element (11) .

7. The protecting device as claimed in any preceding claim, characterized in that said means (5) is designed to extend into the reservoir (2) from an opening (13) in the reservoir.

8. The protecting device as claimed in claim 7, characterized in that said means (5) is suspended in the reservoir (2) from a component (14) disposed in the opening (13) .

9. The protecting device as claimed in claim 8 , characterized in that the suspension component (14) is configured and has a flexibility such that said means (5) can move in relation to the reservoir (2) by flexing of the suspension component (14) when said means is subjected to load as a result of transport of the vehicle (1) .

10. The protecting device as claimed in claim 9, characterized in that the suspension component (14) has a high elasticity in relation to the material of said means (5) .

11. The protecting device as claimed in claim 7, characterized in that said opening (13) is disposed in the upper part of the reservoir (2) .

12. The protecting device as claimed in any preceding claim, characterized in that said means (5) is designed to deter displacement of said frozen medium from a first part-volume (19) of the reservoir (2) to a second part-volume (20) of the reservoir (2) .

13. The protecting device as claimed in claim 12, characterized in that said means (5) is designed to deter displacement of said frozen medium from a first part-volume (19) of the reservoir (2) to a second part-volume (20) of the reservoir (2) , which second part-volume (20) contains a further member (4) disposed inside the reservoir (2) .

14. The protecting device as claimed in claim 13, characterized in that said member (4) is designed to warm said medium in the reservoir (2) .

15. The protecting device as claimed in any one of claims 12-14, characterized in that the first part-volume (19) is situated above the second part-volume (20) .

16. The protecting device as claimed in any one of claims 12-15, characterized in that said means (5) comprises at least one counter-stay (18) .

17. The protecting device as claimed in claim 16, characterized in that said at least one counter- stay (18) is disposed close to a wall (17) of the reservoir (2) .

18. The protecting device as claimed in claim 17, characterized in that said at least one counter- stay (18) is created by the configuration of a wall (17) of the reservoir (2) .

19. The protecting device as claimed in claim 1, characterized in that said means (5) is a resilient layer (15) disposed along at least a part of the inner limit face (16) of the reservoir (2) .

20. The protecting device as claimed in any preceding claim, characterized in that said means (5) is configured and has a flexibility such that said means can move in relation to the reservoir (2) by flexing of said means (5) when said means is subjected to load as a result of transport of the vehicle (1) .

21. The protecting device as claimed in any preceding claim, characterized in that said means (5) is disposed in a reservoir (2) intended to provide a medium for cleaning of exhaust gases from an internal combustion engine.

22. A reservoir (2) which is provided with a protecting device as claimed in any one of patent claims 1-21.

23. A vehicle comprising a reservoir (2) as claimed in patent claim 22.