CONDUIT SYSTEM AND A METHOD OF ASSEMBLING A CONDUIT SYSTEM

Abstract

The invention relates to a conduit system comprising a first conduit (2) having a first engagement portion (3), and a second conduit (12) having a second engagement portion (13), wherein the first conduit (2) and the second conduit (12) are adapted to be connected to each other by means of the first and second engagement portions (3, 13). The first and second engagement portions (3, 13) comprises a first and second slide surface (4, 14), respectively. Said slide surfaces (4,14) extend radially outwards and has an inclination of 20-90 to a respective longitudinal axis (A) of the respective engagement portions. Said conduit system (1) further comprises spring means (20) arranged to urge one of the first and second slide surfaces (4, 14) towards the other one of said first and second slide surfaces (4, 14). The present invention also relates to a vehicle being provided with such a conduit system and to a method of assembling a conduit system for a vehicle.

Claims

1. A conduit system for conveying a high temperature fluid, such as an exhaust gas from an engine, said conduit system comprises a first conduit having a first engagement portion, and a second conduit having a second engagement portion, wherein the first conduit and the second conduit are adapted to be connected to each other by means of the first and second engagement portions, characterized in that the first engagement portion comprises a first slide surface, said first slide surface extending radially outwards from a longitudinal axis of the first conduit at the first engagement portion of the first conduit and has an inclination of 20-90 to said longitudinal axis, wherein the second engagement portion comprises a second slide surface, said second slide surface extending radially outwards from a longitudinal axis of the second conduit at the second engagement portion of the second conduit and has an inclination of 20-90 to said longitudinal axis, and wherein said conduit system further comprises spring means arranged to urge one of the first and second slide surfaces towards the other one of said first and second slide surfaces, such that the first and second slide surfaces form at least a part of a sealing to prevent fluid from escaping the conduit system.

2. A conduit system according to claim 1, wherein the difference in inclination between the first and second slide surfaces is less than 5.

3. A conduit system according to claim 1, wherein said first conduit is of a rigid character and said second conduit is of a flexible character.

4. A conduit system according to claim 1, wherein at least one of said first and second slide surfaces have a curved shape.

5. A conduit system according to claim 1, wherein said spring means is one of a Belleville washer, wave washer, bellow washer or a coil spring.

6. A conduit system according to claim 1, wherein a first sealing member is provided between said first and said second slide surfaces.

7. A conduit system according to claim 6, wherein said first sealing member is a low friction gasket, such as a graphite gasket.

8. A conduit system according to claim 1, wherein said conduit system further comprises a second sealing member.

9. A conduit system according to claim 1, wherein said conduit system further comprises a locking means for locking the spring means in a biased configuration in which it urges one of the first and second slide surfaces towards the other one of said first and second slide surfaces.

10. A conduit system according to claim 9, wherein said locking means is a circlip.

11. A conduit system according to claim 1, wherein said conduit system further comprises a flow guide member provided at least partly in the first and second engagement portions of the first and second conduits, respectively.

12. The conduit system according to claim 1, wherein the conduit system resides within a vehicle.

13. A method of assembling a conduit system comprising a first conduit having a first engagement portion, wherein the first engagement portion comprises a first slide surface, said first slide surface extending radially outwards from a longitudinal axis of the first conduit at the first engagement portion of the first conduit and has an inclination of 20-90 to said longitudinal axis, said method being characterized by the steps of: providing a second conduit having a second engagement portion, wherein the second engagement portion comprises a second slide surface, said second slide surface extending radially outwards from a longitudinal axis of the second conduit at the second engagement portion of the second conduit and has an inclination of 20-90 to said longitudinal axis; arranging one of the first and second slide surfaces such that it is directed towards the other one of said first and second slide surfaces; and arranging spring means such that they urge one of the first and second slide surfaces towards the other one of said first and second slide surfaces.

14. A method according to claim 13, said method further comprises providing a first sealing member between said first and second slide surfaces.

15. A method according to claim 13, said method further comprises providing a locking means for holding said spring means in a biased condition, in which biased condition said spring means urges one of said first and second slide surfaces towards the other one of said first and second slide surfaces.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0059] With reference to the appended drawings, below follows a more detailed description of embodiments of the invention cited as examples.

[0060] In the drawings:

[0061] FIG. 1 is a side view of a truck being provided with a conduit system according to the first aspect of the present invention;

[0062] FIG. 2 is an exploded side view of a conduit system according to the first aspect of the present invention;

[0063] FIG. 3a is a sectioned view of the joint between the first and second conduits in an aligned position;

[0064] FIG. 3b is a sectioned view of the joint between the first and second conduits in a tilted position;

[0065] FIG. 4 is a perspective view of the assembled conduit system with a portion of it cut away; and

[0066] FIG. 5 is a perspective view of another embodiment of the assembled conduit system with a portion of it cut away.

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS OF THE INVENTION

[0067] The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which exemplary embodiments of the invention are shown. The invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided for thoroughness and completeness, and fully convey the scope of the invention to the skilled addressee. Like reference characters refer to like elements throughout the description.

[0068] FIG. 1 schematically illustrates a truck 100, on which a conduit system 1 according to the present invention may be used.

[0069] The present invention, in both the illustrated embodiments as well as other non-illustrated embodiments falling within the scope of the appended claims, is suitable to use for conduits having outside diameters within a wide range. It is for example to use it for conduits having outside diameters of 25.4 mm to 254 mm. In applications for heavy-duty vehicles, it is common that the conduits have outside diameters within a range of 76.2 to 127 mm. The thickness of the walls of the pipes are commonly within a range of 1 to 6 mm. The conduits may for example be ERW steel pipes, DOM steel pipes, extruded aluminium pipes, cast pipes, aluminium silicon coated steel pipes, stainless steel pipes or other metal conduits of ferrous alloys.

[0070] FIGS. 2, 3a, 3b and 4 illustrate an embodiment of the conduit system 1 for conveying a high temperature fluid, such as an exhaust gas from an engine, of the present invention in greater detail. The conduit system 1 comprises a first conduit 2 of rigid character. The first conduit has a first engagement portion 3. The conduit system 1 also comprises a second conduit 12 of flexible character. The second conduit has a second engagement portion 13. The first conduit 2 and the second conduit 12 are adapted to be connected to each other by means of the first and second engagement portions 3, 13.

[0071] The first engagement portion 3 comprises a first slide surface 4, which extends radially outwards from a longitudinal axis A of the first conduit 2 at the first engagement portion 3 The radially outwards extending slide surface has an inclination of 20-90 to said longitudinal axis A. In the illustrated embodiment, the inclination is approximately 50-60. Likewise, the second engagement portion 13 comprises a second slide surface 14. Also 20 the second slide surface extends radially outwards from a longitudinal axis B of the second conduit 12 at the second engagement portion 13. The inclination for the second slide surface is also in the range of 20-90 to the corresponding longitudinal axis B. In the illustrated embodiment, the inclination is approximately 50-60. As the first and second slide surfaces are intended to slide in relation to each other, it is suitable to have at least approximately the same inclination of them. Therefore, the difference in inclination between the first and second slide surfaces 4, 14 is less than 5.

[0072] The first engagement portion 3 also comprises an axial extension portion 5 and a flange 6. The axial extension portion 5 is connected to the outermost end 7 of the first slide surface 4. The extension of the axial extension portion 5 is substantially parallel with the longitudinal axis A of the first conduit 2. The flange 6 is connected to an end 9 of the axial extension portion 5 that is furthest away from the first slide surface 4. The flange 6 has a substantially radial extension in relation to the first conduit 2 and is directed from the axial extension portion 7 inwards, i.e. towards the longitudinal axis A of the first conduit 2. The second engagement portion 13 also comprises an axial extension portion 15. The axial extension portion is connected to the innermost end 18 of the second slide surface 14. When the conduit system 1 is assembled, the extension portions 5, 15 of the respective first and second engagement portions 3, 13 overlap each other, as is clearly seen in e.g. FIGS. 3a, 3b and 4.

[0073] As can be best seen in FIGS. 3a and 3b, the first and second slide surfaces 4, 14 have in this embodiment a curved shape and as they are rotationally symmetrical, they each define a spherical segment. Alternatively, they may each define a rotational symmetrical ovoid segment. When a slide surface is curved, the angle of inclination of it should be measured as the angle of the chord extending between the innermost 8, 18 and outermost end 7, 17 of the respective slide surface 4, 14.

[0074] The conduit system 1 further comprises spring means 20 arranged to urge one of the first and second slide surfaces 4, 14 towards the other one of said first and second slide surfaces 4, 14. The spring means 20 are provided between the axial extension portion 5 of the first engagement portion 3 and the axial extension portion 15 of the second conduit 12. In the illustrated embodiment, it is the second slide surface 14 that is urged towards the first slide surface 4 by the spring means 20. By this arrangement, the first and second slide surfaces 4, 14 form at least a part of a sealing to prevent fluid from escaping the 20 conduit system 1.

[0075] A first sealing member 21, in the form of a low-friction graphite gasket, is provided between said first and said second slide surfaces 4, 14. Hence, in this embodiment, the slide surfaces are not in contact with each other. The first sealing member 21 is held in a constant position in relation to the second slide surface 14 and is arranged to be slideable in relation to the first slide surface 4. In the illustrated embodiment, the first sealing member 21 is held in a constant position in relation to the second slide surface 14 by means of the shape of the second slide surface 14. As can be seen in the figures, the first slide surface has a holding portion or cradle in which the first sealing member 21 is provided. It is however also conceivable to hold the sealing member in a constant position to the second slide surface 14 by other means as well. For example, it may be welded or glued to the first slide surface 14. The purpose of the first sealing member 21 is both to seal the joint, but also to provide a means for simplifying both the rotational movement and the tiltable movement of the second conduit in relation to the first conduit.

[0076] The conduit system 1 further comprises a second sealing member 22. The second sealing member 22 is provided on the opposite side of said spring means 20 as the first sealing member 21. Also the second sealing member 22 is a low-friction graphite gasket. The purpose of the second sealing member 22 is both to seal the joint, but also to provide a means for simplifying the rotational movement of the second conduit in relation to the first conduit.

[0077] A locking means 23 for locking the spring means 20 in a biased configuration in which it urges one of the first and second slide surfaces 4, 14 towards the other one of said first and second slide surfaces 4, 14 is also provided. In the illustrated embodiment, the locking means 23 is a circlip, i.e. a semi-flexible ring with open ends, that can be snapped into place around the flange 6.

[0078] Between the spring means 20 and the second sealing member 22, a first flat washer 25 is provided. Between the second sealing member 22 and the locking means 23, a second 26 and third 27 flat washers are provided. The purpose of the flat washers 25, 26 and 27 are to assist in obtaining a good distribution of the spring force and to provide a flat mating surface for the second sealing member 22. Even though flat washers are illustrated as suitable for obtaining these functions, it is of course possible to use other means for achieving this.

[0079] The conduit system 1 also comprises a flow guide member, e.g. a deflector 24, provided at least partly in the first and second engagement portions 3, 13 of the first and second conduits 2, 12, respectively. Hence, the flow guide member 24 is provided in the joint between the first and second conduits 2, 12. It is in the form of a short pipe with open ends of sheet metal. It has an outer diameter being substantially the same as the inner diameter of the first conduit. Hence, gases flowing from the first conduit will enter the flow guide member 24 and be directed through it and into the second conduit. The risk of fluid leakage through the joint is thereby reduced.

[0080] As can be best seen in FIGS. 3a and 3b, the first and second slide surfaces 4, 14 have in this embodiment a curved shape and the second slide surface 14, by means of the first sealing member 21, can slide along the first slide surface 4 even if they are not in direct contact with each other. In FIG. 3a, the first and second conduits are aligned with each other and the second slide surface 14 is thereby centrally positioned in relation to the first slide surface 4. In FIG. 3b, the second conduit 12 is tilted a few degrees in relation to the first conduit 2. The part of the second slide surface 14 positioned in the upper portion of the drawing has slid downwards against the first slide surface 4 and is now close to the innermost end 8 of that portion of the first slide surface 4. Hence, it has moved closer to the axis A of the first conduit 2. Likewise, at the bottom of the drawing, the portion of the second slide surface 14 has also slid downwards and is now closer to the outermost end 7 of that portion of the first slide surface 4. In fact, the outermost end 17 of the second slide surface 14 is in contact with the outermost end 7 of the first slide surface. Hence, the first slide surface has moved further away from the axis A of the first conduit 2. As can also be seen in FIG. 3b, the upper portion of the second conduit 12 is now abutting the flow guide member 24. Hence, the flow guide member 24 stops the first conduit from moving too far when the conduits are tilted in relation to each other. By using the flow guide member 24 as a stop, less forces have to be taken up by the spring means 20.

[0081] The first and second conduits can also rotate in relation to each other. The ovoid shaped segment, such as a spherical shaped segment, of the first and second slide surfaces allow this rotation without imparting a rotating movement to the second conduit. In other words, when the first conduit rotates, the first sealing member 21, and thereby the second slide 14 and second conduit 12, are still and slides on the first slide surface 4. If it instead was the second conduit that was rotated, the first sealing member 21 would also slide on the first slide surface, leaving the first conduit in its previous position.

[0082] When the conduit system 1 should be assembled, the components are provided to each other in the order illustrated in FIG. 2. Hence, as a first step a first conduit 2 having a first engagement portion 3 comprising a first slide surface 4 extending radially outwards from a longitudinal axis A of the first conduit 2 at the first engagement portion 3 of the first conduit 2 and having an inclination of 20-90 to said longitudinal axis A is provided. Thereafter, as a second step, a second conduit 12 having a second engagement portion 13 comprising a second slide surface 14 extending radially outwards from a longitudinal axis B of the second conduit 12 at the second engagement portion and having an inclination of 20-90 to said longitudinal axis B is provided. As the third step one of the first and second slide surfaces 4, 14 is arranged such that it is directed towards the other one of said first and slide surfaces 4, 14. As a fourth step, spring means 20 are arranged to urge one of first and second slide surfaces 4, 14 towards the other one of said first and second slide surfaces. The method may further comprise providing a first sealing member 21 between said first and second slide surfaces 4, 14 and providing a locking means 23 for holding said spring means 20 in a biased condition, in which biased condition said spring means 20 urges one of said first and second slide surfaces 4, 14 towards the other one of said first and second slide surfaces 4, 14. The method may also comprise the provision of a second sealing member 22 and at least one flat washer 25, 26, 27.

[0083] A fixing tool 30 comprising a first and second part 30a, 30b may be used for assembling the conduit system 1. The first part 30a of the fixing tool 30 comprises a holding portion 31 and three elongate and threaded rods 32 (of which two is shown in the drawings). The holding portion 31 comprises a centrally arranged large hole, dimensioned so that the holding portion 31 can be arranged to circumscribe the first conduit 2, while at the same time not be able to pass by the radially extending first slide surface 4. The second part 30b comprises three holes 34 (of which two is shown in the drawings) dimensioned to be 15 able to receive a respective one of the elongate rods 32. The second part 30b also comprises a centrally arranged large hole, dimensioned so that the second part 30b can be arranged to circumscribe the second conduit 12, while at the same time not be able to pass by the radially extending second slide surface 14. The fixing tool also comprises three wing nuts 33 (of which two is shown in the drawings) dimensioned to threadedly engage the elongate rods 32.

[0084] In order to assemble the conduit system, the first part 30a is provided on the first conduit and the second part 30b is provided on the second conduit, and all components that is to be included in the assembly are provided in the correct order between the first and second parts 30a, 30b of the fixing tool. This is clearly illustrated in FIG. 2. The elongated rods 32 are thereafter inserted into the holes of the second part 30b and the wing nuts 33 are threadedly engaged with the rods 32. By tightening the wing nuts 33, the spring means 20 are compressed and the first and second slide surfaces 4, 14 are brought towards each other. When the compression of the spring means is large enough, the locking means 23 is attached to the flange 6 and thereby locks all components to each other in the desired axial relationship. Once that has been done, the wing nuts 33 may be unthreded from the rods 32 and the fixing tool can be removed. Hence, the fixing tool is not positioned at the conduit system 1 when the conduit system is in use. FIG. 4 illustrates the assembled conduit system when the fixing tool 30 has been removed. A specific fixing tool has been described above. It is however conceivable to use many other fixing tools for compressing the spring means 20 and providing for locking it in a biased configuration in which it urges the first and second slide surfaces 4, 14 towards each other.

[0085] It is to be understood that the present invention is not limited to the embodiment described above and illustrated in FIGS. 2-4; rather, the skilled person will recognize that many changes and modifications may be made within the scope of the appended claims.

[0086] For example, in the illustrated embodiment, said spring means 20 is a Belleville washer. It is however also conceivable to use other types of spring means, such as a wave washer, a coil spring or a bellow spring. Furthermore, the locking means 23 have been illustrated as a circlip. Many other alternatives are however possible, such as e.g. rivets, bolts or welds. Also, the first and second sealing members 21, 22 have been illustrated as graphite gaskets. It is however also conceivable with any other type of low-friction sealing members, such as low-friction material coated bearings or low-friction metal gaskets.

[0087] Another embodiment of the present invention is illustrated in FIG. 5. This embodiment has many features in common with the first embodiment illustrated above, and similar features, functions and advantages will not be elaborated upon again. Instead, the main difference between the embodiment of FIG. 5 and the embodiment of FIGS. 2-4, is that this embodiment has fewer components. As can be seen in FIG. 5, the first and second slide surfaces 4, 14 abut each other and are intended to slide against each other without the use of a first sealing member. Therefore, in this embodiment, the second slide surface 14 is a straight or ovoid, such as spherical, segment having a similar or the same inclination as the first slide surface 4. Also, the spring means 20 are in direct contact with the flange 6 and held in its biased condition by this contact. Therefore, the second sealing member, the flat washers and the locking means that are described for the first embodiment, are not necessary in this embodiment. Furthermore, the flow guide member 24 is also not used in this embodiment.

[0088] This embodiment may be assembled by means of the same fixing tool 32 as described above for the first embodiment, and by the provision of the different components in the correct order as described above for the first embodiment.

[0089] It is to be understood that the present invention is also not limited to the embodiment described above and illustrated in FIG. 5; rather, the skilled person will recognize that many changes and modifications may be made within the scope of the appended claims.