Switchable exhaust system

Abstract

Switchable exhaust system comprising a first exhaust pipe, a second exhaust pipe, and a valve mechanism comprising: a valve member which allows a flow of exhaust gases through the first exhaust pipe in a first position, largely closes the first exhaust pipe in a second position, and is pulled firmly against a valve seat in a third position; a first rod translatable in its longitudinal direction; a first spring which urges the first rod away from the valve seat; a first stop member which limits translation of the first rod away from the valve seat; first coupling means which couple the valve member and the first rod for relative rotation, wherein the rotation axis extends perpendicularly of the longitudinal direction of the first rod; a second stop member which prevents further rotation of the valve member when the second position is reached from the first position; a drive shaft which extends parallel to said rotation axis; a second rod which is connected with a first outer end to the drive shaft and extends from the drive shaft; a third stop member which is connected to the drive shaft and limits rotation of the drive shaft in each of the two rotation directions; a second spring which engages with a first outer end on second coupling means mounted on the valve member and engages with a second outer end on a second outer end of the second rod, and pulls the valve member firmly against the valve seat in the third position. The valve mechanism has been found to be robust and reliable. The exhaust system produces considerably less noise in a quieter mode than a known system of this kind.

Description

FIELD OF THE INVENTION

[0001] The invention relates to a switchable exhaust system, particularly a switchable exhaust system for a recreational craft, more particularly for a speedboat.BACKGROUND OF THE INVENTION

[0002] A switchable exhaust system for a recreational craft, particularly for a speedboat, is known. It is therein possible to switch between a first exhaust pipe debouching above water with a louder, sporty exhaust noise and a second exhaust pipe debouching below water with a quieter, calm exhaust noise. Switching from the first exhaust pipe to the second exhaust pipe or switching from a louder mode to a quieter mode takes place by means of a butterfly valve comprising a disc which in a first rotation position allows a flow of exhaust gases through the first exhaust pipe and in a second rotation position largely closes the first exhaust pipe. This is not a full seal, since the (metal) disc generally does not connect fully to the inner side of the wall of the relevant (metal) pipe and because a clearance of about 1 mm is in any case maintained to accommodate thermal expansion of the disc when the engine and the exhaust system heat up. This means that the known switchable exhaust system still produces a relatively great deal of noise in the quieter mode, and is thus for instance unable to meet a prevailing stricter noise standard, for instance as laid down in the “Directive 2013 / 53 / EU on recreational craft and personal watercraft” in force as of 1 Jan. 2017.

[0003] The present invention now provides a switchable exhaust system comprising an improved valve mechanism, wherein the volume of the exhaust noise in the quieter mode is considerably lower than in a known system of this kind, and which additionally has a number of other advantages.SUMMARY OF THE INVENTION

[0004] The invention provides a switchable exhaust system according to claim 1.

[0005] It has been found that the valve mechanism is robust, reliable, low-maintenance and not very susceptible to failure, and can be produced at a favourable cost price. In the third position the valve member is pulled firmly against the valve seat by means of the second spring. The first exhaust pipe is thus closed optimally. The exhaust system thus produces considerably less noise in the quieter mode than a known system of this kind, and so is for instance able. to meet a prevailing stricter noise standard, for instance as laid down in the “Directive 2013 / 53 / EU on recreational craft and personal watercraft”.BRIEF DESCRIPTION OF THE DRAWINGS

[0006] The invention is further elucidated hereinbelow on the basis of a non-limitative exemplary embodiment. Shown more or less schematically in the drawings:

[0007] FIG. 1 is a section of a switchable exhaust system according to the invention;

[0008] FIG. 2 is the valve mechanism with the valve member in a first position, in which it allows a flow of exhaust gases through the first exhaust pipe;

[0009] FIG. 3 is the valve mechanism with the valve member in a second position, rotated relative to the first position, in which it largely closes the first exhaust pipe; and

[0010] FIG. 4 is the valve mechanism with the valve member in a third position, translated relative to the second position, in which it is pulled firmly against the valve seat and closes the first exhaust pipe optimally.FURTHER ELUCIDATION AND EXEMPLARY EMBODIMENTS

[0011] In the context of the invention ‘parallel’ and ‘perpendicularly’ are in each case understood to mean respectively ‘at least substantially parallel’ and ‘at least substantially perpendicularly’.

[0012] The switchable exhaust system (1) according to the invention shown in the figures comprises a first exhaust pipe (2) comprising a first outlet mouth (3) and a second exhaust pipe (4) comprising a second outlet mouth (5). In a situation of use the first outlet mouth (3) and the second outlet mouth (5) are located respectively above and below the water. The exhaust system (1) also comprises a valve mechanism (6) comprising a disc-shaped valve member (7) and a valve seat (11).

[0013] The valve member (7) can rotate from a first position, see FIG. 2, in which it allows a flow of exhaust gases through the first exhaust pipe (2), to a second position, see FIG. 3, in which it largely closes the first exhaust pipe (2), and can translate from the second position to a third position, see FIG. 4, in which it is pulled firmly against the valve seat (11). The valve mechanism (6) also comprises a first rod (13) translatable in its longitudinal direction and guide means (16) which guide the translation of the first rod (13). The valve mechanism (6) also comprises a first spring (19) which urges the first rod (13) away from the valve seat (11) in a translation direction. The first spring (19) engages here with a first outer end (20) on a first outer end (14) of the first rod (13) and with a second outer end (21) remote from the first outer end (20) on a first side (17) of the guide means (16). The valve mechanism (6) also comprises a first stop member (22) which impedes further translation of the first rod (13) away from the valve seat (11) when a given extreme translation position of the first rod (13) is reached. The first stop member (22) is here connected to a second outer end (15) remote from the first outer end (14) of the first rod (13) and strikes against a second side (18) remote from the first side (17) of the guide means (16) when the given extreme translation position of the first rod (13) is reached, see FIGS. 1 and 2.

[0014] The valve mechanism (6) also comprises first coupling means (23) which are mounted on a first side (8) of the valve member (7) and which couple the valve member (7) and the first rod (13) for relative rotation about a first rotation axis (10), wherein a first rotation axis (10) extends perpendicularly of the longitudinal direction of the first rod (13), and also a second stop member (24) which prevents further rotation of the valve member (7) when the second position is reached from the first position, see FIGS. 2 and 3. The second stop member (24). here an adjusting bolt, is here fastened to the first rod (13), this at the second outer end (15) thereof, and is adjustable in a direction parallel to the longitudinal direction of the first rod (13) such that the rotation position of the valve member (7) is adjustable in the second position. This can achieve that the valve member (7) connects optimally to the valve seat (11) in the third position, see FIG. 4.

[0015] The valve mechanism (6) also comprises a drive shaft (25) rotatable about a second rotation axis (26), which second rotation axis (26) extends parallel to the first rotation axis (10). The valve mechanism (6) also comprises a second rod (27) which is connected with a first outer end (28) to the drive shaft (25) and extends, here perpendicularly, from the drive shaft (25), and a third stop member (30) which is also connected to the drive shaft (25) and limits rotation of the drive shaft (25) in each of the two rotation directions to an extreme rotation position of the drive shaft (25). The third stop member (30) comprises here a third rod which is connected with a first outer end (31) to the drive shaft (25) and extends, here perpendicularly, from the drive shaft (25), and which strikes with a second outer end (32) remote from the first outer end (31) against the inner wall of the first exhaust pipe (3) in each of the two rotation directions of the drive shaft (25) when the extreme rotation position of the drive shaft (25) is reached, see FIGS. 2 and 4.

[0016] The valve mechanism (6) also comprises a second spring (33) which engages with a first outer end (34) on second coupling means (36) mounted on a second side (9) remote from the first side (8) of the valve member (7) and which engages with a second outer end (35) on a second outer end (29) remote from the first outer end (28) of the second rod (27). The second spring (33) pulls the valve member (7) firmly against the valve seat (11) in the third position, see FIG. 4. An optimal closure of the first exhaust pipe (2) thus takes place. The valve seat (11) is here formed by a heat-resistant rubber gasket (12) which also serves as closure of a flange connection.

[0017] The valve mechanism (6) here also comprises a fourth stop member (37), here mounted on the guide means (16) which guide the translation of the first rod (13), which prevents further rotation of the valve member (7) when the first position is reached from the second position, see FIGS. 2 and 3. The valve member (7) is here in the first position pressed against the fourth stop member (37) by the second spring (33). This prevents the valve member (7) from ‘rattling’ and / or ‘flapping’ against the guide means (16) in the first position.

[0018] The drive shaft (25) is here driven by means of an electric motor (not shown) whereby the whole valve mechanism (6) can thus be driven and controlled, and the valve member (7) can be rotated and translated as desired between the three positions shown in the figures.REFERENCE SYMBOLS USED1. switchable exhaust pipe

[0020] 2. first exhaust pipe

[0021] 3. first outlet mouth (of 2; above water)

[0022] 4. second exhaust pipe

[0023] 5. second outlet mouth (of 4; under water)

[0024] 6. valve mechanism

[0025] 7. disc-shaped valve member

[0026] 8. first side of 7

[0027] 9. second side of 7

[0028] 10. first rotation axis (of 7)

[0029] 11. valve seat

[0030] 12. heat-resistant rubber gasket

[0031] 13. translatable first rod

[0032] 14. first outer end of 13

[0033] 15. second outer end of 13

[0034] 16. guide means (for guiding 13)

[0035] 17. first side of 16

[0036] 18. second side of 16

[0037] 19. first spring

[0038] 20. first outer end of 19

[0039] 21. second outer end of 19

[0040] 22. first stop member (for limiting translation of 13)

[0041] 23. first coupling means (for rotatably coupling 7 and 13)

[0042] 24. second (adjustable) stop member (for limiting rotation of 7; adjusting bolt)

[0043] 25. drive shaft

[0044] 26. second rotation axis (of 25)

[0045] 27. second rod

[0046] 28. first outer end of 27

[0047] 29. second outer end of 27

[0048] 30. third stop member (for limiting rotation of 25; third rod)

[0049] 31. first outer end of 30

[0050] 32. second outer end of 30

[0051] 33. second spring

[0052] 34. first outer end of 33

[0053] 35. second outer end of 33

[0054] 36. second coupling means (for coupling 33 and 7)

[0055] 37. fourth stop member (for limiting rotation of 7)

[0056] 38. exhaust gasses emitted by engine

Claims

1. Switchable exhaust system (1), particularly a switchable exhaust system for a recreational craft, more particularly for a speedboat, comprising a first exhaust pipe (2). a second exhaust pipe (4) and a valve mechanism (6) comprising a disc-shaped valve member (7) and a valve seat (11), which valve member (7) can rotate from a first position in which it allows a flow of exhaust gases through the first exhaust pipe (2) to a second position in which it largely closes the first exhaust pipe (2), and can translate from the second position to a third position in which it is pulled firmly against the valve seat (11), for which purpose the valve mechanism (6) also comprises:a first rod (13) translatable in its longitudinal direction;guide means (16) which guide the translation of the first rod (13);a first spring (19) which urges the first rod (13) away from the valve seat (11) in a translation direction;a first stop member (22) which impedes further translation of the first rod (13) away from the valve seat (11) when a given extreme translation position of the first rod (13) is reached;first coupling means (23) which are mounted on a first side (8) of the valve member (7) and which couple the valve member (7) and the first rod (13) for relative rotation about a first rotation axis (10), wherein the first rotation axis (10) extends perpendicularly of the longitudinal direction of the first rod (13);a second stop member (24) which prevents further rotation of the valve member (7) when the second position is reached from the first position;a drive shaft (25) rotatable about a second rotation axis (26), which second rotation axis (26) extends parallel to the first rotation axis (10);a second rod (27) which is connected with a first outer end (28) to the drive shaft (25) and extends from the drive shaft (25);a third stop member (30) which is connected to the drive shaft (25) and limits rotation of the drive shaft (25) in each of the two rotation directions to an extreme rotation position of the drive shaft (25);a second spring (33) which engages with a first outer end (34) on second coupling means (36) mounted on a second side (9) remote from the first side (8) of the valve member (7) and which engages with a second outer end (35) on a second outer end (29) remote from the first outer end (28) of the second rod (27), and which pulls the valve member (7) firmly against the valve seat (11) in the third position.

2. Exhaust system (1) according to claim 1, characterized in that the first spring (19) engages with a first outer end (20) on a first outer end (14) of the first rod (13) and engages with a second outer end (21) remote from the first outer end (20) on a first side (17) of the guide means (16).

3. Exhaust system (1) according to claim 2, characterized in that the first stop member (22) is connected to a second outer end (15) remote from the first outer end (14) of the first rod (13) and strikes against a second side (18) remote from the first side (17) of the guide means (16) when the given extreme translation position of the first rod (13) is reached.

4. Exhaust system (1) according to any one of the claims 1-3, characterized in that the second stop member (24) is fastened to the first rod (13) and is adjustable in a direction parallel to the longitudinal direction of the first rod (13), such that the rotation position of the valve member (7) is adjustable in the second position of the valve member (7).

5. Exhaust system (1) according to any one of the claims 1-4, characterized in that the third stop member (30) comprises a third rod which is connected with a first outer end (31) to the drive shaft (25) and extends from the drive shaft (25), and which strikes with a second outer end (32) remote from the first outer end (31) against the inner wall of the first exhaust pipe (3) in each of the two rotation directions of the drive shaft (25) when the extreme rotation position of the drive shaft (25) is reached.

6. Exhaust system (1) according to any one of the claims 1-5, characterized in that the valve mechanism (6) also comprises a fourth stop member (37) which prevents further rotation of the valve member (7) when the first position is reached from the second position.

7. Exhaust system (1) according to claim 6, characterized in that the valve member (7) is in the first position pressed against the fourth stop member (37) by the second spring (33).

8. Exhaust system (1) according to any one of the claims 1-7, characterized in that the valve seat (11) comprises a heat-resistant rubber gasket (12).

9. Exhaust system (1) according to any one of the claims 1-8, characterized in that the exhaust system (1) also comprises an electric motor for driving the drive shaft (25).

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