GB2560343A

GB2560343A - Exhaust valve apparatus

Info

Publication number: GB2560343A
Application number: GB1703699.7A
Authority: GB
Inventors: Christopher Robert Petley Dean
Original assignee: Jaguar Land Rover Ltd
Current assignee: Jaguar Land Rover Ltd
Priority date: 2017-03-08
Filing date: 2017-03-08
Publication date: 2018-09-12
Also published as: GB201703699D0

Abstract

An exhaust valve assembly 2 for controlling exhaust gas flow from an internal combustion engine 3 includes a pivotally mounted valve body 7 which is movable between an open position and a closed position. A valve control mechanism 12 controls the valve body and has a biasing means 13 for biasing the valve body towards the closed position. The valve control mechanism has a protective housing 20 for protecting the biasing means. The protective housing may partially or completely enclose the biasing means, and may comprise a substantially sealed chamber. The housing may have first and second parts, which may translate or rotate relative to each other. The housing may comprise a resiliently deformable cover attached to couplings at first and second ends of the biasing means. The biasing means may be a torsion spring or a tension spring. A vehicle (4, fig 1) comprises an exhaust system (1) having the exhaust valve assembly.

Description

(54) Title of the Invention: Exhaust valve apparatus Abstract Title: Exhaust valve apparatus (57) An exhaust valve assembly 2 for controlling exhaust gas flow from an internal combustion engine 3 includes a pivotally mounted valve body 7 which is movable between an open position and a closed position. A valve control mechanism 12 controls the valve body and has a biasing means 13 for biasing the valve body towards the closed position. The valve control mechanism has a protective housing 20 for protecting the biasing means. The protective housing may partially or completely enclose the biasing means, and may comprise a substantially sealed chamber. The housing may have first and second parts, which may translate or rotate relative to each other. The housing may comprise a resiliently deformable cover attached to couplings at first and second ends of the biasing means. The biasing means may be a torsion spring or a tension spring. A vehicle (4, fig 1) comprises an exhaust system (1) having the exhaust valve assembly.

At least one drawing originally filed was informal and the print reproduced here is taken from a later filed formal copy.

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FIG. 2

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FIG. 3

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EXHAUST VALVE APPARATUS

TECHNICAL FIELD

The present disclosure relates to an exhaust valve apparatus. In particular, but not exclusively, the present disclosure relates to exhaust valve assembly for controlling exhaust gas flow. The present disclosure also relates to an exhaust system and a vehicle.

BACKGROUND

It is known to provide a passive exhaust valve in an exhaust system of a vehicle, such as an automobile, for the purpose of attenuating undesirable noise produced in the exhaust system. The exhaust valve comprises a valve body which locates in an exhaust conduit for conveying exhaust gases from an internal combustion engine. The valve body is biased to a closed position by a spring element. The flow of exhaust gas through the exhaust conduit displaces the valve body to an open position against the closing force applied by the spring element. In prior art exhaust valves, the spring element is mounted to the outside of the exhaust conduit in an exposed position to facilitate maintenance and servicing, as required.

It has been determined that the prior art exhaust valves may be subject to jamming in certain scenarios. The valve body may be jammed in an open position and fail to close the exhaust conduit; or may be jammed in a closed or partially closed position in which the flow of exhaust gases through the exhaust conduit is prevented or restricted. If the valve body is jammed in a closed position, the restriction in the exhaust system may result in damage to the internal combustion engine. This has been identified as a particular problem in vehicles that are driven off-road or on un-metalled roads or trails since the operating conditions may be particularly harsh or extreme. The exhaust system may be subjected to a variety of adverse conditions, including: mud, water, stones, gravel, etc. These conditions may damage the exhaust valve and potentially result in the valve body becoming jammed.

At least in certain embodiments, the present invention seeks to overcome or ameliorate at least some of the problems associated with the prior art systems.

SUMMARY OF THE INVENTION

Aspects of the present invention relate to an exhaust valve assembly; to an exhaust system; and to a vehicle as claimed in the appended claims.

According to a further aspect of the present invention there is provided an exhaust valve assembly for controlling exhaust gas flow from an internal combustion engine, the exhaust valve assembly comprising:

a pivotally mounted valve body, the valve body being movable between an open position and a closed position; and a valve control mechanism for controlling the valve body, the valve control mechanism comprising biasing means for biasing the valve body towards the closed position;

wherein the valve control mechanism comprises a protective housing for protecting the biasing means. The biasing means is provided in the protective housing. In use, the protective housing protects the biasing means and helps reduce the possibility of the valve body being jammed. By way of example, the protective housing may help to reduce or prevent the build of mud, debris, stones and the like proximal to the biasing means. At least in certain embodiments the reliability of the exhaust valve assembly may be improved.

The protective housing may be configured partially or completely to enclose the biasing means. The protective housing may comprise a chamber in which the biasing means is located. At least in certain embodiments the chamber may be at least substantially sealed. The protective housing may be watertight to prevent the ingress of water.

The protective housing may be permanently mounted in place. Alternatively, the protective housing may be removable to facilitate servicing and/or maintenance of the biasing means.

The protective housing may comprise at least one split line to facilitate servicing and/or removal. The protective housing may comprise first and second housing parts. The first and second housing parts may be joined along said at least one split line. The first and second housing parts may be formed from an alloy or a metal. For example, the first and second housing parts may be formed of stainless steel. Alternatively, the first and second housing parts may be formed from a plastics material, for example injection moulded from a plastics material.

The first and second housing parts may have first and second surfaces adapted to cooperate with each other to seal the protective housing. A seal, such as an O-ring, or a gasket may be provided between said first and second housing parts to form said seal.

The first and second housing parts may be permanently or releasably fastened to each other. One or more mechanical fastener may be provided to fasten the first and second housing parts to each other. Alternatively, the first and second housing parts may be welded or bonded together. If the first and second housing parts are moulded from a plastics material, a plastic weld may be used to join them together. Alternatively, or in addition, the first and second housing parts may comprise interlocking features or clips arranged to engage with each other when the protective housing is assembled. In a further alternative, the first and second housing parts may be crimped together.

At least one of said first and second housing parts may be movably mounted. For example, at least one of said first and second housing parts may translate and/or rotate relative to the other of the first and second housing parts. The first housing part may be coupled to a first end of the biasing means; and/or the second housing part may be coupled to a second end of the biasing means. The first and second housing parts may be movable relative to each other. The first housing part may comprise a first coupling for coupling to a first end of the biasing means. The second housing part may comprise a second coupling for coupling to a second end of the biasing means. The first and second couplings may be configured to transmit torsional forces. The first and second couplings may be formed integrally with the first and second housing parts.

The first and second housing parts may be fixedly connected to each other. The protective housing may be fixedly mounted. The protective housing may form a chamber in which the biasing means is mounted. The chamber may be sized to accommodate changes in the longitudinal and/or transverse dimension of the biasing means. Thus, at least in certain embodiments, the protective housing may be configured so as not to impinge or hinder the operation of the biasing means.

In a further alternative, the protective housing may comprise a resiliently deformable cover provided around said biasing means. The exhaust valve assembly may comprise a first coupling coupled to a first end of the biasing means, and a second coupling coupled to a second end of the biasing means. The resiliently deformable cover may be attached to said first and second couplings. The first and second couplings may be arranged to transmit torque. The protective housing may comprise a tubular member.

The biasing means may be in the form of apparatus for biasing the valve body towards the closed position. The biasing means may comprise spring biasing means. The spring biasing means may provide passive control of the valve body. The opening and closing of the valve body may be controlled by the properties of the spring biasing means. The spring biasing means may, for example, comprise a spring element. The biasing means may comprise a torsion spring or a tension spring.

According to a further aspect of the present invention there is provided an exhaust system comprising at least one exhaust valve assembly as described herein.

According to a further aspect of the present invention there is provided a vehicle comprising an exhaust system as described herein.

Within the scope of this application it is expressly intended that the various aspects, embodiments, examples and alternatives set out in the preceding paragraphs, in the claims and/or in the following description and drawings, and in particular the individual features thereof, may be taken independently or in any combination. That is, all embodiments and/or features of any embodiment can be combined in any way and/or combination, unless such features are incompatible. The applicant reserves the right to change any originally filed claim or file any new claim accordingly, including the right to amend any originally filed claim to depend from and/or incorporate any feature of any other claim although not originally claimed in that manner.

BRIEF DESCRIPTION OF THE DRAWINGS

One or more embodiments of the present invention will now be described, by way of example only, with reference to the accompanying figures, in which:

Figure 1 shows a schematic representation of a vehicle having an exhaust system and an exhaust valve assembly in accordance with an embodiment of the present invention;

Figure 2 is a perspective view of the exhaust valve assembly shown in Figure 1; Figure 3 shows an end elevation of the exhaust valve assembly shown in Figure 2; Figure 4 shows an end elevation of a variant of the exhaust valve assembly shown in Figure 2; and

Figure 5 shows a perspective view of an exhaust valve assembly according to a further embodiment of the present invention.

DETAILED DESCRIPTION

An exhaust system 1 comprising an exhaust valve assembly 2 in accordance with an embodiment of the present invention will now be described with reference to the accompanying figures. The exhaust system 1 is arranged to convey exhaust gases from an internal combustion engine 3 provided in a vehicle 4, as illustrated in Figure 1. In the present embodiment, the vehicle 4 is an off-road vehicle suitable for driving off-road.

As shown in Figure 2, the exhaust system 1 comprises a conduit 5 defining an exhaust gas flow path F. The exhaust valve assembly 2 comprises a valve body 7 operable to block at least a substantial portion of the conduit 5. As described herein, the valve body 7 is pivotally mounted in the conduit 5 and is arranged to provide passive control of the exhaust gas flowrate along the exhaust gas flow path F. The valve body 7 is pivotable between an open position and a closed position. The valve body 7 is shown in the closed position in Figure 2. In the closed position, the valve body 7 extends across the conduit 5 and the flow of exhaust gas through the conduit 5 is at least substantially prevented. In the open position, the valve body 7 is displaced such that the flow of exhaust gas through the conduit 5 is not restricted. In the present embodiment the valve body 7 is fastened to a rotatable shaft 8 extending across the conduit 5. The shaft 8 is supported by first and second bushings 9-1, 9-2 and is rotatable about a rotational axis Y1 (shown in Figure 3) extending substantially parallel to a diameter of the conduit 5. The first and second bushings 9-1, 9-2 are disposed in respective first and second support members 10-1, 10-2 mounted to the conduit 5. In the present embodiment the first and second support members 10-1, 10-2 have a rectangular section. The first bushing 9-1 comprises a first bore 11-1 for receiving a first end 8A of the shaft 8; and the second bushing 9-2 comprises a second bore 11-2 for receiving a second end 8B of the shaft 8. The first and second bushings 9-1, 9-2 are configured to form a sealed connection with the shaft 8.

The first end 8A of the shaft 8 extends through said first bore 11-1 and is arranged to cooperate with a valve control mechanism 12 configured to control the opening and closing of the valve body 7. The valve control mechanism 12 is fixedly mounted to the first support member 10-1. The valve control mechanism 12 comprises biasing means for biasing the valve body 7 towards the closed position. In the present embodiment the biasing means comprises a torsion spring 13 having a first end 13A and a second end 13B. The valve body 7 is displaced from said closed position by the flow of exhaust gas through the conduit 5. Thus, the valve control mechanism 12 is a passive mechanism in the present embodiment. The valve control mechanism 12 comprises a first coupling 14 and a second coupling 15 for mounting the torsion spring 13. The first coupling 14 is fixedly mounted to the first support member 10-1 to inhibit rotation of the first coupling 14 about the rotational axis Y1. A first keyed connection may be formed between the first coupling 14 and the first support member 10-1 to prevent rotation of the first coupling 14 relative to the first support member 10-1. The second coupling 15 is fixedly mounted to the shaft 8 such that the second coupling 15 rotates with the shaft 8. A second keyed connection may be formed between the second coupling 15 and the shaft 8 to prevent rotation of the second coupling 15 relative to the shaft

8. A fastener (not shown), such as a locking pin or clip, is provided on the shaft 8 to mount the second coupling 15.

As shown in Figures 2 and 3, the torsion spring 13 comprises a helical spring mounted between said first and second couplings 14, 15. The torsion spring 13 is arranged to transmit a torsional force (torque) between said first and second couplings 14, 15. The first and second couplings 14, 15 are arranged to seat the first and second ends 13A, 13B of the torsion spring 13. The first end 13A of the torsion spring 13 is connected to the first coupling 14; and the second end 13B of the torsion spring 13 is connected to the second coupling 15. The first end 13A of the torsion spring 13 comprises a first projection 16 which is located in a first aperture 17 formed in the first coupling 14 to transmit torque. The second end 13B of the torsion spring 13 comprises a second projection 18 which is located in a second locating aperture 19 formed in the second coupling 15 to transmit torque. The rotation of the shaft 8 rotates the second coupling 15 and applies a torque to the second end 13B of the torsion spring 13. The first end 13A of the torsion spring 13 is prevented from rotating by the first coupling 14. The torsion spring 13 applies a restoring force to the second coupling 15 which is transmitted to the shaft 8 in order to bias the valve body 7 towards the closed position.

As shown in Figure 3, the exhaust valve assembly 2 comprises a protective housing 20 for protecting the valve control mechanism 12. In use, the protective housing 20 functions as a guard to protect the valve control mechanism 12. The protective housing 20 may, for example, protect against the ingress of liquids, such as water or mud; and/or damage from loose objects, such as stones; and/or fixed obstacles, such as rocks and terrain features. In the present embodiment the protective housing 20 is fixedly mounted to the first support member 10-1. The protective housing 20 has a rigid construction and is configured to enclose the torsion spring 13, the first coupling 14 and the second coupling 15. The protective housing 20 comprises first and second housing parts 21, 22 which are joined together to form a hollow chamber 23 in which the control mechanism 12 is mounted. The hollow chamber 23 is sized so as not to impede operation of the valve control mechanism

12. In particular, the hollow chamber 23 is sized so as not to restrict the rotational movement of the shaft 8 or the second coupling 15.

The first and second housing parts 21, 22 are formed of metal, such as stainless steel. The first and second housing parts 21,22 have cooperating surfaces which align with each other when the protective housing 20 is assembled. In the present embodiment, the first and second housing parts 21, 22 are welded together to seal the protective housing 20. In use, the protective housing 20 prevents the ingress of debris and/or liquid into the valve control mechanism 12. The protective housing 20 helps to prevent debris collecting in the torsion spring 13. The protective housing 20 may maintain reliable operation of the valve control mechanism 12.

As described herein, the vehicle 4 is an off-road vehicle which may be driven in an off-road environment, for example on an un-metalled surface or off-rad. In these types of scenario, the exhaust system 1 is more likely to come into contact with rocks, stones and other debris. In extreme scenarios, the exhaust system 1 may be partially or completely immersed in water. The protective housing 20 is operative to protect the valve control mechanism 12 and to help reduce the likelihood of the valve body 7 being jammed in an open or closed position. The protective housing 20 can prevent the build-up of mud on the valve control mechanism 12 (so-called mud-packing), or obstruction of the valve control mechanism 12 by a stone or other debris (so-called stone-jamming); these scenarios may otherwise impinge on operation of the valve control mechanism 12 and inhibit the pivoting movement of the valve body 7.

In the arrangement shown in Figure 3, the first and second housing parts 21,22 are made of metal and welded together. It will be understood that the first and second housing parts 21, 22 may be formed of different materials. For example, the first and second housing parts 21, 22 may be moulded from a plastics material. Furthermore, different techniques may be used to join the first and second housing parts 21, 22. For example, one or more mechanical fastener may be used to join the first and second housing parts 21,22.

A variant of the protective housing 20 is illustrated in Figure 4. In this arrangement, the first and second housing parts 21, 22 are moulded from a plastics material and form a sealed protective housing 20. The seal may be formed by the interface between the first and second housing parts 21, 22. Alternatively, or in addition, a seal or gasket may be provided between the first and second housing parts 21, 22. The first and second housing parts 21, 22 are moulded as separate components which are then joined together. To facilitate assembly, the first and second housing parts 21, 22 comprise interlocking features, for example male and female features, which cooperate with each other to fasten the first and second housing parts 21, 22 together. It will be appreciated that the first and second parts 21, 22 could be moulded as a single component, for example joined to each other along a live hinge.

In a further variant, the protective housing 20 comprises first and second housing parts 21, 22 which are movable relative to each other to accommodate rotation of the shaft 8. The first housing part 21 may be fixedly mounted to the first support member 10-1. Alternatively, the first housing part 21 could be mounted to the first end 13A of the torsion spring 13. The second housing part 22 may be mounted to the shaft 8, for example by fastening an endwall of the second housing part 22 to the shaft 8. Alternatively, the second housing part 22 could be mounted to the second end 13B of the torsion spring 13. The first and second couplings 14, 15 may be incorporated into the first and second housing parts 21, 22 respectively. The first housing part 21 may comprise a first cylinder; and the second housing part 22 may comprise a second cylinder. The first and second cylinders may be arranged coaxially along the rotational axis Y1 of the shaft 8. The first and second cylinders are arranged concentrically such that at least a portion of one of the cylinders locates inside the other cylinder to form the protective housing 20. The first and second cylinders may be movable relative to each other to accommodate relative movement of the shaft 8. The first and second cylinders may, for example, form a telescopic joint. The resulting interface enables the first and second housing parts 21,22 to rotate relative to each other to permit rotation of the shaft 8. This interface may also allow the second housing part 22 to translate relative to the first housing part 21 to accommodate axial expansion/contraction of the torsion spring

13. A seal could optionally be provided to prevent the ingress of liquid. The seal could, for example be provided inside the protective housing 20 around the torsion spring 13; or outside the protective housing 20. The seal could, for example, comprise a flexible gaiter.

In a further variant, the protective housing 20 may comprise a resiliently deformable sleeve which extends around the torsion spring 13. The sleeve may be fastened at each end to the first and second couplings 14, 15. The sleeve is arranged to deform when the first and second couplings 14, 15 rotate relative to each other. The sleeve may comprise a flexible tubular cover provided around the torsion spring 13, for example.

The present invention has been described with reference to the torsion spring 13. It will be understood that other types of spring may be used to apply a biasing force to the valve body

7. A further embodiment of the present invention will now be described with reference to Figure 5. Like reference numerals are used for like components.

The valve body (not shown) is pivotally mounted in the conduit 5. In this embodiment the torsion spring 13 is replaced with a tension spring 25 having a first end 25A and a second end 25B. The first end 25A of the tension spring 25 is fixedly mounted to the conduit 5; and the second end 25B of the tension spring 25 is connected to the valve body 7, for example via a lever or crank (not shown). The tension spring 25 is arranged to bias the valve body 7 towards the closed position. In use, the tension spring 25 is extendible along a longitudinal axis X1. The protective housing 20 comprises first and second housing parts 21, 22 fixedly mounted to the conduit 5. The first and second housing parts define the hollow chamber 23 which is sized to accommodate the extension of the tension spring 25. The first and second housing parts 21, 22 cooperate with each other to form a seal to inhibit the ingress of liquid and/or debris.

It will be appreciated that various modifications may be made to the embodiment(s) described herein without departing from the scope of the appended claims.

Claims

CLAIMS:

1. An exhaust valve assembly for controlling exhaust gas flow from an internal combustion engine, the exhaust valve assembly comprising:

wherein the valve control mechanism comprises a protective housing for protecting the biasing means.

2. An exhaust valve assembly as claimed in claim 1, wherein the protective housing is configured to partially or completely enclose the biasing means.

3. An exhaust valve assembly as claimed in claim 2, wherein the protective housing comprises a chamber in which the biasing means is located, the chamber being at least substantially sealed.

4. An exhaust valve assembly as claimed in any one of claims 1, 2 or 3, wherein the protective housing comprises first and second housing parts.

5. An exhaust valve assembly as claimed in claim 4, wherein at least one of said first and second housing parts is movably mounted.

6. An exhaust valve assembly as claimed in claim 5, wherein at least one of said first and second housing parts translates and/or rotates relative to the other of the first and second housing parts.

7. An exhaust valve assembly as claimed in claim 4, wherein the first and second housing parts are fastened together.

8. An exhaust valve assembly as claimed in claim 7, wherein the protective housing is fixedly mounted.

9. An exhaust valve assembly as claimed in any one of claims 1, 2 or 3, wherein the protective housing comprises a resiliently deformable cover provided around said biasing means.

10. An exhaust valve assembly as claimed in claim 9 comprising a first coupling coupled to a first end of the biasing means, and a second coupling coupled to a second end of the biasing means; wherein the resiliently deformable cover is attached to said first and second couplings.

11. An exhaust valve assembly as claimed in claim 9 or claim 10, wherein the protective housing comprises a tubular member.

12. An exhaust valve assembly as claimed in any one of the preceding claims, wherein the biasing means comprises a torsion spring or a tension spring.

13. An exhaust system comprising at least one exhaust valve assembly as claimed in any one of the preceding claims.

14. A vehicle comprising an exhaust system as claimed in claim 13.

15. An exhaust valve assembly substantially as herein described with reference to the accompanying figures.

16. An exhaust system substantially as herein described with reference to the accompanying figures.

17. A vehicle substantially as herein described with reference to the accompanying figures.

Intellectual

Property

Office

Application No: GB1703699.7 Examiner: Rachel Smith