WO2006036485A1

WO2006036485A1 - Spring and cable assembly for noise attenuation valve

Info

Publication number: WO2006036485A1
Application number: PCT/US2005/031853
Authority: WO
Inventors: Joseph Callahan; Ivan Arbuckle; Kwin Abram
Original assignee: Arvin Technologies, Inc.
Priority date: 2004-09-22
Filing date: 2005-09-08
Publication date: 2006-04-06

Abstract

A preload mechanism (50) for a noise attenuation valve assembly takes up slack and clearance between valve components to reduce operational noises. The noise attenuation valve assembly includes a shaft (16) having first (20) and second (24) shaft ends, a flapper valve body (18) supported by the shaft (16), and an actuator (27) that drives the shaft (16) to rotate the flapper valve body (18) within an exhaust (14) component to attenuate noise. The preload mechanism includes a spring (56) and cable assembly having a first cable (52) connected to the first shaft end (20), a second cable (54) connected to the second shaft end (24), and a spring member (56) that is coupled to the first (52) and second (54) cables. The spring member (56) is biased to pull the first (52) and second (54) cables toward each other, which exerts a preload force on the shaft (16) to take up clearance and slack.

Description

SPRING AND CABLE ASSEMBLY FOR NOISE ATTENUATION VALVE

RELATED APPLICATIONS

The application claims priority to U.S. Provisional Application No. 60/612,082, which was filed on September 22, 2004.

BACKGROUND OF THE INVENTION

Noise attenuation valves are often used in vehicle exhaust systems to reduce noise generated during vehicle operation. In one example, a noise attenuation valve is incorporated into a muffler to reduce noise generated by a vehicle engine.

Traditionally, the noise attenuation valve includes a flapper valve mounted on a shaft that pivots the flapper valve within an inlet tube formed within the muffler. The inlet tube defines an open passage through which exhaust gases flow. The flapper valve has a disc shaped body that rotates within the inlet tube to vary exhaust gas flow area. The shaft is coupled to a solenoid with a linkage assembly. A controller controls the solenoid to rotate the shaft via the linkage assembly. As the shaft rotates, the flapper valve varies the exhaust gas flow area as needed to attenuate noise.

One disadvantage with this traditional configuration is that components in the noise attenuation valve and solenoid generate operational noise. For example, movement of the linkage assembly and rotation of the shaft can generate noises due to slack and clearance between the components.

Thus, it is desirable to provide a noise attenuation valve that reduces operational noises.

SUMMARY OF THE INVENTION

A noise attenuation valve assembly includes a preload mechanism that takes up slack and clearance between valve components to reduce operational noises. The preload mechanism includes a spring and cable assembly having a first cable connected to one end of the noise attenuation valve assembly, a second cable connected to an opposite end of the noise attenuation valve assembly, and a spring member that is coupled to the first and second cables. The spring member is biased to pull the first and second cables toward each other, which exerts a preload force on the noise attenuation valve assembly to take up clearance and slack.

The noise attenuation valve assembly includes a shaft having first and second shaft ends, a flapper valve body supported by the shaft, and an actuator that drives the shaft to rotate the flapper valve within an exhaust component to attenuate noise. The first cable is operably coupled to the first shaft end and the second cable is operably coupled to the second shaft end. In one example configuration, and the second cable is directly attached to the second shaft end. In another example configuration, the second cable is attached to a linkage assembly that couples the second shaft end to the actuator. In either configuration, the slack and/or clearance between the various components is taken up by the preload force exerted by the spring and the first and second cables, which results in reduced operational noises.

These and other features of the present invention can be best understood from the following specification and drawings, the following of which is a brief description.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a front end view of an exhaust component with a noise attenuation valve assembly and preload mechanism incorporating the subject invention.

Figure 2 is a schematic view of the noise attenuation valve assembly of Figure 1 with a control system.

Figure 3 is a schematic view of one embodiment of an attachment interface for the preload mechanism.

Figure 4 is a schematic view of another embodiment of an attachment interface for the preload mechanism. Figure 5 is a schematic view of another embodiment of an attachment interface for the preload mechanism.

Figure 6 is a schematic view showing one end of the preload mechanism attached to a linkage assembly.

Figure 7 is a schematic view showing both ends of the preload mechanism attached being attached to a shaft in the noise attenuation valve assembly. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

As shown in Figure 1, a muffler 10 includes a datum plate 12 that supports an inlet tube 14 that receives exhaust gases. A noise attenuation valve assembly includes a shaft 16 and a flapper valve 18 that is fixed to the shaft 16. The shaft 16 has a first shaft end 20 supported in a first bushing 22 and a second shaft end 24 supported in a second bushing 26 (Figure 2). The first 20 and second 24 shaft ends extend along an axis Al (Figure 2). The shaft 16 rotates within the first 22 and second 26 bushings about the axis Al to move the flapper valve 18 within the inlet tube 14 to vary exhaust gas flow area.

As shown in Figure 2, the shaft 16 is driven by a control mechanism 25 to control the position of the flapper valve 18 within the inlet tube 14. The control mechanism 25 includes an actuator 27 and a linkage assembly 30 that couples the shaft 16 to the actuator 27. In the example shown, the actuator 27 is a solenoid 28. A controller 32 controls the solenoid 28 to rotate the shaft 16 via the linkage assembly 30. In one example, the controller 32 comprises an engine management system, which generates a control signal 38 to control actuation of the solenoid 28. The solenoid 28 rotates the shaft 16, which changes the position of the flapper valve 18 to vary the exhaust gas flow area as needed to attenuate noise.

The solenoid 28 is supported by a support tube 34 (Figure 1) that is attached to the datum plate 12. A linkage stop 36 limits the rotational actuation range of the solenoid 28 and linkage assembly 30. One example of the linkage assembly 30 and linkage stop 36 is described in co-pending application serial number , which is assigned to the assignee of the present invention and is incorporated herein by reference. While this linkage assembly 30 is preferred, other linkage assembly configurations could also be used to couple the solenoid 28 to the shaft 16. As shown in Figure 2, the solenoid 28 includes a plunger 40 that is coupled to the linkage assembly 30. The plunger 40 moves in a linear direction along an axis A2 to rotate the linkage assembly 30. The axis A2 is positioned transversely relative to axis Al defined by the shaft 16. The linkage stop 36 limits the rotational actuation range of the linkage assembly 30, however, the subject invention could also be used in a configuration that does not include a linkage stop 36. As discussed above, the linkage assembly 30 rotates the shaft 16 to control movement of the flapper valve 18 to attenuate noise. The operation of the controller 32, solenoid 28, and flapper valve 18 to control noise is known and will not be discussed in further detail.

The noise attenuation valve assembly includes a preload mechanism, shown generally at 50, that takes up slack and clearance between valve components to reduce operational noises. The preload mechanism 50 is a resilient mechanism that applies a preload to the shaft 16 to take up any clearance and/or slack that exist between various noise attenuation valve components. The preload mechanism 50 is operably coupled to the first shaft end 20 and the second shaft end 24.

As shown in Figures 1 and 2, the preload mechanism 50 includes a first cable 52, a second cable 54, and a spring 56 extending between the first 52 and second 54 cables. The spring 56 is resiliency biased to pull the first 52 and second 54 cables generally toward each other. In other words, the spring 56 pulls the first 52 and second 54 cables together to exert preload forces on both ends of the shaft 16.

The first cable 52 extends around a first guide member 58 supported on the datum plate 12 and the second cable 54 extends around a second guide member 60 supported on the datum plate 12. The first 58 and second 60 guide members assist with supporting and controlling loading paths of the first 52 and second 54 cables, however, the first 58 and second 60 guide members may not be required.

In the example shown, the first 58 and second 60 guide members comprise pins that extend outwardly from the datum plate 12. The first cable 52 extends about a portion of the outer periphery of the first guide member 58 and the second cable 54 extends about a portion of the outer periphery of the second guide member 60. The first 58 and second

60 guide members define the load paths for the first 52 and second 54 cables and assist in maintaining a tension force on the first 52 and second 54 cables. The first 52 and second 54 cables can be attached to the shaft 16 with various attachment interfaces. In one example attachment interface, the first 52 and second 54 cables can be attached to the shaft 16 with a looped connection 62 as shown in Figure 3.

Optionally, the first 52 and second 54 cables can be attached to the shaft 16 with a washer attachment 64 as shown in Figure 4. In one configuration, the second cable 54 is coupled to the linkage assembly 30 as shown in Figure 5. The linkage assembly 30 includes a lever 66 that is mounted at a first lever portion 66a to the shaft 16. The lever 66 includes a second lever portion 66b that is mounted to a clevis 68. The first 66a and second 66b lever portions are preferably at opposite ends of the lever 66. The second cable 54 is attached to the clevis 68 as shown at 70. The clevis 68 is coupled to an additional linkage member 72, which is coupled to the plunger 40 of the solenoid 28. This configuration is shown in greater detail in Figure 6. In the configuration shown in Figure 6, the first bushing 22 is located within a short hub 76 and the second bushing is located within a long hub 78. The preload mechanism 50 applies a first preload force (indicated generally at 80) to the first shaft end 20 at the first bushing 22, and a second preload force (indicated generally at 82) to a pin clevis joint at the second shaft end 24. In another configuration shown in Figure 7, the second cable 54 is attached to the second shaft end 24 adjacent to the linkage assembly 30. In this configuration the preload mechanism 50 applies a first preload force (indicated generally at 90) to the first shaft end 20 at the first bushing 22, and a second preload force (indicated generally at 92) to the second shaft end 24 at the second bushing 26. As described above, the first bushing 22 is located within the short hub 76 and the second bushing is located within the long hub 78.

In any of the configurations, the first 52 and second 54 cables can be attached to the spring 56 by various attachment interfaces. In the examples shown, the spring 56 has hooks at each end that are received in loops on the first 52 and second 54 cables. Further, in each configuration, the spring 56 generates the first and second preload forces by pulling the first 52 and second 54 cables together. By exerting these preload forces, slack and/or clearance between the various components is taken up, which results in reduced operational noises.

It should be understood that while the preload mechanism for the noise attenuation valve assembly is shown in a muffler, the preload mechanism could also be used for noise attenuation valve assemblies in other types of exhaust components.

Although a preferred embodiment of this invention has been disclosed, a worker of ordinary skill in this art would recognize that certain modifications would come within the scope of this invention. For that reason, the following claims should be studied to determine the true scope and content of this invention.

Claims

CLAIMSWhat is claimed is:

1. A preload mechanism for a noise attenuation valve assembly comprising: a resilient member having a first portion operably coupled to a first end of the noise attenuation valve assembly and a second portion operably coupled to a second end of the noise attenuation valve assembly, said first portion and said second portion being resiliently biased to preload the noise attenuation valve assembly.

2. The preload mechanism according to claim 1 wherein said resilient member comprises a spring and cable assembly.

3. The preload mechanism according to claim 2 including a shaft supporting a valve between first and second shaft ends and wherein said first end of the noise attenuation valve assembly comprises said first shaft end and said second end of the noise attenuation valve assembly comprises said second shaft end.

4. The preload mechanism according to claim 3 wherein said spring and cable assembly includes a first cable having one end attached to said first shaft end and a second cable having one end attached to said second shaft end.

5. The preload mechanism according to claim 4 including a spring extending between said first and said second cables.

6. The preload mechanism according to claim 5 wherein said spring biases said first and second cables in a direction generally towards each other.

7. The preload mechanism according to claim 3 wherein said second shaft end is coupled to said second portion via a linkage assembly, and wherein said spring and cable assembly includes a first cable having one end attached to said first shaft end and a second cable having one end attached to said linkage assembly with a spring extending between said first and said second cables.

8. A preload mechanism for a noise attenuation valve assembly comprising: a shaft having a first shaft end and a second shaft end extending along an axis; a flapper valve body supported by said shaft for rotation about said axis; a resilient member having a first portion operably coupled to said first shaft end and a second portion operably coupled to said second shaft end, said first portion and said second portions being resiliently biased to pull said first and second portions generally towards each other.

9. The preload mechanism according to claim 8 wherein said resilient member comprises a spring and cable assembly having a first cable portion coupled to said first shaft end, a second cable portion coupled to said second shaft end, and a spring coupled between said first and second cable portions.

10. The preload mechanism according to claim 9 wherein said first cable portion is directly attached to said first shaft end with a first attachment interface and said second cable portion is directly attached to said second shaft end with a second attachment interface.

11. The preload mechanism according to claim 10 wherein at least one of said first and second attachment interfaces comprises at least one of a cable loop attachment and a washer attachment.

12. The preload mechanism according to claim 9 wherein said second shaft end is coupled to said second cable portion with a linkage assembly.

13. The preload mechanism according to claim 12 wherein said linkage assembly includes a lever that has a first lever portion fixed to said second shaft end and a second lever portion mounted to a clevis, said second cable portion being attached to said clevis.

14. The preload mechanism according to claim 8 including an actuator that drives said shaft to rotate said flapper valve body within a tube to vary exhaust flow area to attenuate noise.

15. A muffler assembly comprising: an outer shell; an inlet tube supported within said outer shell; a noise attenuation valve including a valve shaft and a flapper valve mounted on said valve shaft within said inlet tube, said valve shaft including a first shaft end supported within a first bushing and a second shaft end supported within a second bushing; a linkage assembly coupled to said second shaft end; an actuator coupled to said linkage assembly to selectively rotate said valve shaft; and a resilient mechanism operably coupled to said valve shaft to exert a preload force on said valve shaft.

16. The muffler assembly according to claim 15 wherein said resilient mechanism comprises a spring and cable assembly.

17. The muffler assembly according to claim 16 wherein said spring and cable assembly includes a first cable portion coupled to said first shaft end, a second cable portion coupled to said second shaft end, and a spring coupled between said first and second cable portions to bias said first and second cable portions in a direction generally towards each other.

18. The muffler assembly according to claim 17 wherein said actuator comprises a solenoid having a plunger movable in a linear direction along a first axis, said plunger moving said linkage assembly to rotate said valve shaft about a second axis that is transverse to said first axis.

19. The muffler assembly according to claim 17 including a datum plate mounted within said outer shell to support said inlet tube, said datum plate including a first guide member cooperating with said first cable portion to define a first load path for said first cable portion and a second guide member cooperating with said second cable portion to define a second load path for said second cable portion.

20. The muffler assembly according to claim 19 wherein said first and second guide members comprise first and second pins with said first cable portion extending about at least a portion of an outer circumference of said first pin and said second cable portion extending about at least a portion of an outer circumference of said second pin.