Abstract:
A reactive acoustic dampener includes a nested three chambered configuration and connecting tubes that may be fully integrated into the fuel rail of a fuel injection system.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims priority to U.S. provisional patent application Ser. No. 60/955,283, filed on Aug. 10, 2007, which is fully incorporated herein by reference. 
     
    
     FIELD 
       [0002]    This present disclosure relates generally to acoustic filters and more particularly, to multi-chambered acoustic filters configured with connecting tubes that are less costly to manufacture. 
       BACKGROUND 
       [0003]    Acoustic filters are used to dampen pulsation vibrations in fluid flow systems. It has been the practice (see, e.g., U.S. Pat. No. 2,993,559 to Everett) to provide an internal flow element within a vessel arranged to divide and recombine flowing fluids to offset and cancel pulsations. This has been accomplished by defining separate flow paths by means of bulkheads and connecting tubes. 
         [0004]    As is well known in the art, whenever fluids are pumped under high pressure, pulsating vibrations will undoubtedly occur. High intensity noise may also occur in systems that produce high frequency pulsations. In addition to noise and vibration, there exists a possibility that the vibrations will damage system piping or components. The potential damage necessitates incurring substantial maintenance and equipment replacement costs. Thus, there is a need for an fluid pulsation dampener that operates quietly and efficiently, and prevents component deterioration as described above. 
       SUMMARY 
       [0005]    The various embodiments and examples provided herein are generally directed to acoustic dampener systems. The disclosed embodiments generally describe a fluid pulsation dampener that substantially attenuates pulsations in a given frequency range. The disclosed embodiments permit acoustic dampeners to have smaller overall dimensions and may be economically produced and implemented. This is largely accomplished by the three-chamber structure described below, wherein there are few inner bulkheads and shorter connecting tubes. 
         [0006]    Moreover, the disclosed embodiments may be used as a fluid pulsation dampener for fuel injection systems. Typically, fuel injection systems generate modest amount of noise and vibration. By incorporating the disclosed pulsation dampener into the fuel rail of a fuel injection system, it may attenuate the fluid pulsations and vibrations generated by the fuel injectors of the internal combustion engine. 
         [0007]    These, as well as other objects, features and benefits will now become clear from a review of the following detailed description of illustrative embodiments and the accompanying figures. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS  
         [0008]    Aspects of the present invention are illustrated by way of example, and not by way of limitation, in the accompanying drawings wherein: 
           [0009]      FIG. 1  is a longitudinal cross-sectional view of the acoustic dampener, integrated in the Fuel Rail of a Fuel Injection System; 
           [0010]      FIG. 2  is a cross-sectional view of the connecting area of Chamber  1 , Chamber  2 , and Chamber  3  through the helical grooves machined in Plug  2  and Tube  2 ; and 
           [0011]      FIG. 3  is a cross-sectional view of connecting area of Chamber  1  and Chamber  2  through the helical groove machined in Plug  1 . 
       
    
    
     DETAILED DESCRIPTION  
       [0012]    The detailed description set forth below in connection with the appended figures is intended as a description of various embodiments of the invention disclosed herein and is not intended to represent the only embodiments in which the invention may be practiced. The detailed description includes specific details for providing a thorough understanding of the invention. It will be apparent to those skilled in the art, however, that the invention may be practiced without these specific details. 
         [0013]      FIG. 1  is a longitudinal cross-sectional view of an acoustic dampener. For purposes of this disclosure, acoustic dampener and pulsation dampener may be used interchangeably without straying from the spirit of the exemplary embodiment herein since both acoustic and pulsation dampeners have the ability to carry sound. In one exemplary embodiment, the acoustic dampener  100  is integrated into the fuel rail of a fuel injection system. The pulsation dampener  100  consists of Tube  1 , which is the fuel rail with attached injector sockets  102 . Tube  2  is lodged inside Tube  1  in a coaxial arrangement, defining an annular Chamber  1 , which is the pulsation inlet for the un-dampened pulsations generated by the injectors (not shown) in the injector sockets  102 . In the exemplary embodiment, the fluid inlet  104  designates the area where the fluid enters the dampener  100 , while pulsations inlet, i.e. Chamber  1 , designates the area where the pulsations enter the dampener  100 . The fluid inlet  104  and the pulsation inlet may or may not be identical in structure, depending on the pulsation&#39;s source location. 
         [0014]      FIG. 2  is a cross-sectional view of the connecting area of Chamber  1 , Chamber  2 , and Chamber  3  through the helical grooves  200  machined in Plug  2  and Tube  2 . Tube  3 , which is partially inserted in Tube  1 , provides the second support for Tube  2  inside Tube  1 . Plug  3 , inserted into the opposite end of Tube  3 , is the fluid inlet port  104  of the pulsation dampener  100 . Plug  3  also seals Chamber  3  inside Tube  3 . (See  FIG. 1 ). The three expansion chambers (Chamber  1 , Chamber  2  and Chamber  3 ) work in cooperative fashion so as to substantially cancel or eliminate unwanted noise that may arise from the acoustic or pulsation properties of fluid flow. 
         [0015]    In the disclosed embodiment, the un-dampened pulsations may enter either Chamber  1  or Chamber  2 , wherein one is placed inside the other. Chamber  3 , which can also be a partition of Chamber  1  or Chamber  2 , is the outlet for the dampened pulsations. The series of connecting tubes in the disclosed arrangement may allow fluid flow in and out of the chambers (Chamber  1 , Chamber  2 , and Chamber  3 ) or, alternatively, split and recombine the flow in a predefined sequence. 
         [0016]      FIG. 3  is a cross-sectional view of connecting area of Chamber  1  and Chamber  2  through the helical groove  200  machined in Plug  1 . Plug  1  seals the end of Tube  1  and Tube  2  and provides support for Tube  2  inside Tube  1 . The opposite end of Tube  2 , having a helical groove  200  on its outer surface, is inserted into Tube  3  and plugged by the Plug  2 . (See  FIG. 2 ). 
         [0017]    The connecting tubes (Tube  1 , Tube  2 , and Tube  3 ) of the exemplary embodiment are the helical grooves  200  machined on the outer surfaces of Plug  1  and Plug  2  and on the outer surface of the fluid inlet end of Tube  2  (See  FIGS. 2 and 3 ). Plug  1  connects Chamber  1  and Chamber  2  while Plug  2  connects Chamber  2  and Chamber  3 . Chamber  1  and Chamber  3  are connected by the helical groove  200  at the end of Tube  2 . In an exemplary embodiment, the connections between the tubes may be largely accomplished by friction fit between the helical groove  200  structure and the immediately surrounding tube. As one of ordinary skill in the art may appreciate, one may substitute an equivalent structure so as to bond the connecting tubes together without deviating from the scope of the disclosed embodiments. 
         [0018]    While the specification describes particular embodiments of the present invention, those of ordinary skill can devise variations of the present invention without departing from the inventive concept. Also, the previous description is provided to enable any person skilled in the art to practice the various embodiments described herein. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments. Thus, the claims are not intended to be limited to the embodiments shown herein, but is to be accorded the full scope consistent with the language of the claims, wherein reference to an element in the singular is not intended to mean “one and only one” unless specifically so stated, but rather “one or more.” All structural and functional equivalents to the elements of the various embodiments described throughout this disclosure that are known or later come to be known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed by the claims. Moreover, nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is explicitly recited in the claims. No claim element is to be construed under the provisions of 35 U.S.C. §112, sixth paragraph, unless the element is expressly recited using the phrase “means for” or, in the case of a method claim, the element is recited using the phrase “step for.”