Patent Publication Number: US-6334460-B1

Title: Pressure regulator baffle seat with radial flow paths

Description:
FIELD OF THE INVENTION 
     This invention relates to a baffle seat for a pressure regulator for automotive fuel systems, and more particularly to a baffle seat having a geometry which reduces the noise associated with high fuel flow rates through the baffle seat. 
     BACKGROUND OF THE INVENTION 
     Most modern automotive fuel systems utilize fuel injectors to deliver fuel to the engine cylinders for combustion. The fuel injectors are mounted on a fuel rail to which fuel is supplied by a pump. The pressure at which the fuel is supplied to the fuel rail must be metered to ensure the proper operation of the fuel injectors. Metering is carried out using pressure regulators which control the pressure of the fuel in the system at all engine r.p.m. levels. 
     Known pressure regulators, as shown in FIG. 5, employ a spring biased valve seat with a longitudinal flow passage. A detailed view of a known valve seat is shown in FIG.  6 . The valve seat is biased to a closed position to prevent the flow of fuel through the pressure regulator at low fuel pressures. As fuel pressure builds in the system, the pressure against the valve seat overcomes the biasing force of the spring, allowing fuel to flow through the valve seat, thereby controlling the fuel pressure in the system. 
     Fuel flow rate, measured in liters per hour, through known pressure regulators tends to be low at high engine speed; measured in revolutions per minute, as large quantities of fuel are consumed in the combustion process. And at low engine speeds, less fuel is consumed in combustion and flow rates through the pressure regulators are high. These high fuel flow rates through known pressure regulator valve seats produce unacceptably high noise levels. A valve seat is needed that maintains flow noise within acceptable levels, even at high fuel flow rates. 
     SUMMARY OF THE INVENTION 
     The present invention provides a flow-through pressure regulator which maintains a substantially constant noise output from low fuel flow rates to high fuel flow rates. The flow-through pressure regulator includes a housing having an inlet and an outlet offset along a longitudinal axis. The housing is separated by a divider into a first chamber and a second chamber. The divider has a passage that communicates the first chamber with the second chamber. The passage includes a first section extending along the longitudinal axis and a second section extending transverse to the longitudinal axis. A closure member permits or inhibits flow through the passage. 
     The divider can include a baffle seat that is suspended by the divider in the housing and provides the passage. The baffle seat has a first seat portion and a second seat portion disposed along the longitudinal axis on opposite sides of the divider such that the first seat portion is disposed the first chamber and the second seat portion is disposed in the second chamber. The first section of the passage extends along the longitudinal axis through the first portion and into the second portion of the seat. The second section of the passage extends transverse to the longitudinal axis in the second portion of the seat. 
     The baffle seat can comprise a first surface disposed in the first chamber, a second surface disposed in the second chamber, and a side surface disposed between the first surface and the second surface. The first section of the passage communicates with the first surface and the second section communicates with the side surface. The first section has a first wall extending from the first surface of the seat to an end wall within the second portion of the seat, and the second section has a second wall extending from the first wall to the side surface. The second wall extends from the first wall to diametrically opposed locations on the side surface, and intersects the first wall proximate the end wall. 
     In a preferred embodiment, the divider is a diaphragm, and a first biasing element is located in the second chamber. The closure member includes a ball disposed in a retainer. The housing includes a first cup-shaped member and a second cup-shaped member. In a preferred embodiment, the flow-through pressure regulator of the present invention has a sound rating in Sones that remains substantially constant from a low fuel flow rate to a high fuel flow rate. 
     The present invention also provides a low noise baffle seat for a flow-through regulator. The baffle seat has an exit geometry which reduces output noise levels at high fuel flow rates. The baffle seat includes a first seat portion having a first surface disposed about a central axis, a second seat portion having a second surface offset from the first surface along the central axis, a side surface disposed between the first surface and the second surface and a passage extending from the first surface through the first portion and the second portion to the side surface. The passage has a first section and a second section. The first section of the passage extends along the central axis in both the first portion and the second portion of the baffle seat. The second section of the passage extends transverse to the longitudinal axis in the second portion of the baffle seat. The first section communicates with the first surface and the second section communicates with the side surface. 
     The present invention also provides a method of stabilizing noise generation in a flow-through regulator. The flow-through regulator includes a housing with an inlet and an outlet offset along a longitudinal axis, a divider separating the housing into a first chamber and a second chamber, a passage through the divider that provides communication between the first chamber and the second chamber, and a closure member that permits or inhibits flow through the passage. The method is achieved by providing the passage with a first section extending along the longitudinal axis and a second section extending transverse to the longitudinal axis, and communicating the first section with the first chamber and the second section with the second chamber. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The accompanying drawings, which are incorporated herein and constitute part of this specification, illustrate presently preferred embodiments of the invention and, together with the general description given above and the detailed description given below, serve to explain features of the invention. 
     FIG. 1 illustrates a flow-through regulator according to the present invention. 
     FIG. 2 illustrates the baffle seat of the flow-through regulator shown in FIG.  1 . 
     FIG. 3 illustrates a detailed view of the baffle seat of the present invention and a closure member. 
     FIG. 4 is a graph illustrating the relationship between noise and flow rate. 
     FIG. 5 illustrates a prior art pressure regulator. 
     FIG. 6 illustrates a detailed view of a prior art valve seat. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     FIG. 1 illustrates a flow-through pressure regulator  10  according to the present invention. The flow-through pressure regulator  10  includes a housing  20 . The housing  20  is separated by a divider  30  into a first chamber  40  and a second chamber  50 . The divider  30  has a passage  60  that communicates the first chamber  40  with the second chamber  50 . A closure member  70  permits or inhibits flow through the passage  60 . A filter  80  is disposed in the flow path of the housing  20 . The housing  20 , has an inlet  202  and an outlet  204  offset along a longitudinal axis A. The housing  20  can include a first cup-shaped member  206  and a second cup-shaped member  208  that are crimped together to form a unitary housing  20  with a hollow interior  211 . Although the unitary housing is formed by two joined members, it is to be understood that the unitary housing could be formed with multiple members integrated together or, alternatively, a monolithic member. The inlet  202  of the housing  20  is located in the first cup-shaped member  206 , and the outlet  204  of the housing  20  is located in the second cup-shaped member  208 . The inlet  202  can be a plurality of apertures  210  located in the first cup-shaped member  206 . The outlet  204  can be a port  212  disposed in the second cup-shaped member  208 . 
     The first cup-shaped member  206  can include a first base  214 , a first lateral wall  218  extending in a first direction along the longitudinal axis A from the first base  214 , and a first flange  220  extending from the first lateral wall  218  in a direction substantially transverse to the longitudinal axis A. The second cup-shaped member  208  can include a second base  222 , a second lateral wall  224  extending in a second direction along the longitudinal axis A from the second base  222 , and a second flange  226  extending from the second lateral wall  224  in a direction substantially transverse to the longitudinal axis A. A divider  30 , which can be a diaphragm  300 , is secured between the first flange  220  and the second flange  226  to separate the first chamber  40  and the second chamber  50 . The first flange  220  can be rolled over the circumferential edge of the second flange  226  and can be crimped to the second flange  226  to form the unitary housing  20 . 
     A first biasing element  90  which is preferably a spring, is located in the second chamber  50 . The first biasing element  90  engages a locator  228  on the base  222  of the second cup-shaped member  208  and biases the diaphragm  300  toward the base  214  of the first-cup shaped member  206 . The first biasing element  90  biases the diaphragm  300  of the regulator  10  at a predetermined force, which relates to the pressure desired for the regulator  10 . The base  222  of the second cup-shaped member  208  has a dimpled center portion that provides the outlet port  212  in addition to the locator  228 . The first end of the spring  90  is secured on the locator  228 , while a second end of the spring  90  can be supported by a retainer  302 , which is secured to a baffle seat  304  mounted in a central aperture  306  in the diaphragm  300 . 
     FIG. 2 shows a preferred embodiment of the baffle seat  304 . The baffle seat  304  is suspended by the divider  30  in the housing  20  (FIG. 1) to provide the passage  60 , having a first section  602  and a second section  604 . The baffle seat  304  has a first seat portion  304 A and a second seat portion  304 B disposed along the longitudinal axis A. The first seat portion  304 A is disposed in the first chamber  40  and the second seat portion  304 B is disposed in the second chamber  50  (FIG.  1 ). The first section  602  of the passage  60  extends along the longitudinal axis A in both the first portion  304 A and the second portion  304 B of the baffle seat  304 . The second section  604  of the passage  60  extends transverse to the longitudinal axis A in the second portion  304 B of the baffle seat  304 . 
     The baffle seat  304  preferably has a first surface  308  disposed in the first chamber  40  (FIG.  1 ), a second surface  310  disposed in the second chamber  50  (FIG.  1 ), and a side surface  312  extending between the first surface  308  and the second surface  310 . The first section  602  of the passage  60  communicates with the first surface  308  and the second section  604  of the passage  60  communicates with the side surface  312 . The first section  602  has a first wall  606  extending from the first surface  308  to an end wall  314  within the second portion  304 B, and the second section  604  has a second wall  608  extending from the first wall  606  to the side surface  312 . The second wall  608  can extend in opposite directions from the first wall  606  to locations on the side surface  312 , and intersects the first wall  606  proximate the end wall  314 . Of course, the second wall  608  can extend in a single radial direction from the first wall  606 . 
     It should be noted that the baffle seat  304  of the present invention can be manufactured as a monolithic valve seat or, alternatively, as separate components that can be assembled. The baffle seat  304  can be used to retrofit existing valve seats having only a longitudinal flow path. For example, the separate components can comprise a cap providing an end wall  314  and a second section  604  of the passage  60 . 
     At an end of the passage  60  opposite the end wall  314  is a seating surface  62  on which the closure member  70 , which can be a valve actuator ball  64 , seats. FIG. 3 shows the ball  64  seated on the valve surface  62 . This surface  62  begins at an inner edge of a pocket  66  which has its side walls  68  converging toward the axis A of the baffle seat  304 . This end of the baffle seat  304  opens into the first chamber  40  (FIG.  1 ). In the manufacturing of the baffle seat  304 , the seating surface  62  is finished to assure a smooth sealing surface for the ball  64 . 
     FIG. 3 shows that the closure member  70  can include a ball  64  disposed in a retainer  72 . The retainer  72  is located in the first chamber  40  (FIG.  1 ), and has a flat annulus  720  secured to a valve actuator housing  722 . The housing  722  can have an internal funnel  724  that includes a conical portion  726  confronting the flat annulus  720  and a cylindrical portion  728  occluded by an end wall  729 . The conical portion  726  of the funnel  724  can support the ball  64 . The cylindrical portion  728  of the funnel  724  supports a spring  74  that biases the ball  64  toward the divider  30  (FIG.  1 ). The conical portion  726  is sized so as to not interfere with the movement of the ball  64 . The ball  64  is retained by the flat annulus  720  on a ball surface opposite the spring  74 . The annulus  720  has a central aperture  720 A that is somewhat smaller than the diameter of the ball  64 . The aperture  720 A is finished to prevent a rough surface from contacting the ball  64 . At the wide end of the funnel  724  there is formed a pocket  76 . The annulus  720 , which is located above the major diameter of the ball or its horizontal axis, is located in the pocket  76  against the inside of the upper edge of the valve actuator housing  722 . The annulus  720  has an outside diameter which is smaller than the diameter of the pocket  76  of the housing  722  and can be retained against separation from the housing  722  by crimping of the upper edge  722 A of the valve actuator housing  722  over the annulus  720 . The annulus  720  is not held tightly in the pocket  76  at the end of the funnel  724 , but is free to move both axially and radially in the pocket  76 . 
     One method of assembling the fuel regulator  10  is by first securing the valve actuator housing  722  to the first cup-shaped member  206 . The small bias spring  74  is placed in the bore  728 . The ball  64  is then located in the conical portion  726  of the funnel  724  formed in the valve actuator housing  722 . Next, the annulus  720  is placed in the pocket  76  on the upper edge of the housing  722  and the edges  722 A of the housing  722  are crimped over to retain the annulus  720  in the pocket  76 . The baffle seat  304  is located and secured in the central aperture  306  of the diaphragm  300  between a flange  304 C of the baffle seat member  304  and the spring retainer  302 . This completed diaphragm is located on the upper flange surface  220  of the first cup-shaped member  206 . The bias spring  90  is positioned in the spring retainer  302  and the second cup-shaped member  208  is then placed over the spring  90  and located on the diaphragm  300 . The flange  220  of the first cup-shaped member  206  is crimped down to secure the second cup-shaped member  208 . The first and second cup-shaped members  206 , 208  and the diaphragm  300  form a unitary member. The pressure at which the fuel is maintained is determined by the spring force of the bias spring  90 . 
     The operation of the flow-through pressure regulator will now be described. The bias spring  90  acts through the retainer  302  to bias the divider  30  toward the base  214  of the first cup-shaped member  206 . The spring  74  functions to bias the ball  64  against the seating surface  62  in the baffle seat member  304 . When the ball  64  is seated against surface  62 , the baffle seat is in a closed position and no fuel can pass through the regulator. 
     Fuel enters the regulator  10  through apertures  210  and exerts pressure on the divider  30 . When the pressure of the fuel is greater than the force exerted by the large bias spring  90 , the diaphragm  300  moves in an axial direction and the ball  64  leaves the seating surface  62  of the baffle seat member  304 . Fuel can then flow through the regulator  10 . The fuel enters the first section  602  of the passage  60 , then passes into the second section  604 . In the second section  604 , the fuel is diverted transversely to the longitudinal axis A, and leaves the baffle seat  304  through the side surface  312 . Experimentation has shown that this exit geometry on the baffle seat provides a substantially constant noise output level from a low fuel flow rate to a high fuel flow rate. 
     As the fuel pressure is reduced, the force of the large bias spring  90  overcomes the fuel pressure and returns the baffle seat member  304  to seated engagement with the ball  64 , thus closing the passage  60  in the baffle seat member  304 . 
     As shown in FIG. 4, curve  102  shows that noise is generally consistent over a range of flow rates according to the present invention. In contrast, curve  104  shows that noise increases substantially as flow increases through conventional regulators. 
     While the invention has been disclosed with reference to certain preferred embodiments, numerous modifications, alterations, and changes to the described embodiments are possible without departing from the sphere and scope of the invention, as defined in the appended claims and their equivalents thereof. Accordingly, it is intended that the invention not be limited to the described embodiments, but that it have the full scope defined by the language of the following claims.