Patent Publication Number: US-2004055645-A1

Title: Flow-through pressure regulator including a housing with a press-fit closure member assembly

Description:
FIELD OF THE INVENTION  
       [0001] A fuel pressure regulator relieves over-pressure in a fuel supply line between a fuel tank and an internal combustion engine. In particular, the fuel pressure regulator is responsible for supplying fuel, at or below a selected pressure, to a fuel injector of the internal combustion engine.  
       BACKGROUND OF THE INVENTION  
       [0002] 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 that control the pressure of the fuel in the system at all engine r.p.m. levels.  
       [0003] A known flow-through pressure regulator includes a separate closure member assembly that is staked to a housing. An example of such a known flow-through pressure regulator is shown in FIG. 4. In particular, a separate closure member assembly  10  is staked to a housing  20 . The closure member assembly  10  includes a machined ball pocket  12 , a spring  14 , a ball  16 , and a ball retainer  18 .  
       [0004] It is believed that such a known flow-through pressure regulators suffer from a number of disadvantages including a manufacturing process that requires additional assembly operations as well as tooling to perform the staking. For example, in the known flow-through pressure regulator, the ball pocket is machined during a separate manufacturing step.  
       [0005] Thus, it is believed that there is a need to provide a flow-through pressure regulator that overcomes the disadvantages of the known flow-through pressure regulator.  
       SUMMARY OF THE INVENTION  
       [0006] The present invention provides a flow-through pressure regulator including a divider that separates first and second chambers, a closure member, a housing, and a shell. The divider includes a passage that extends along an axis and provides fluid communication between the first and second chambers. The closure member moves relative to the divider between first and second configurations. The first configuration substantially prevents fluid communication through the passage, and the second configuration permits fluid communication through the passage. The housing includes first and second housing parts. The first housing part includes a fluid flow inlet and defines the first chamber, and the second housing part includes a fluid flow outlet and defines the second chamber. The shell defines a pocket that receives the closure member. And the shell is displaced along the longitudinal axis relative to the first housing part so as to be press fitted with respect to the first housing portion.  
       [0007] The present invention also provides a method of manufacturing a flow-through pressure regulator. The flow-through pressure regulator includes a closure member that cooperates with a divider to prevent a flow of fluid through the flow-through pressure regulator in a first configuration, and to permit the flow of fluid through the flow-through pressure regulator in a second configuration. The method includes forming a first housing part that defines a fluid flow inlet, forming a shell that defines a pocket adapted to receive a majority of the closure member, coupling the shell and first housing part, forming a second housing part that defines a fluid flow outlet, and coupling the first and second housing parts. The coupling the shell and first housing part includes press fitting the shell with respect to the first housing part, and the coupling the first and second housing parts sandwiches the divider between the first and second housing parts. 
     
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
     [0008] 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.  
     [0009]FIG. 1 is a cross-section view of a flow-through pressure regulator according to a preferred embodiment that includes a closure member assembly that is integrated with a housing.  
     [0010]FIG. 2 is a cross-section views of a homogeneous shell for the flow-through pressure regulator shown in FIG. 1.  
     [0011]FIG. 3 is a group of detail views of a housing part for the flow-through pressure regulator shown in FIG. 1.  
     [0012]FIG. 4 is a partial cross-section view of a known flow-through pressure regulator including a separate closure member assembly that is staked to a housing assembly. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
     [0013]FIG. 1 shows a preferred embodiment of a flow-through pressure regulator  100 , including a closure member assembly that is integrated with a housing, according to the present invention. The flow-through pressure regulator  100  includes a housing  200  defining an interior volume  400 . The interior volume  400  of the housing  200  is separated by a divider  300  into a first chamber  410  and a second chamber  420 . The divider  300  includes a passage  302  that provides fluid communication between the first and second chambers  410 , 420 . A closure member  500  prevents or permits flow-through the passage  302 .  
     [0014] The housing  200  has a fluid flow inlet  202  and a fluid flow outlet  204  spaced along a longitudinal axis A. The housing  200  can include a first housing part  220  and a second housing part  230  that are secured together to form the housing  200  that defines the interior volume  400 . Preferably, the manner of securing includes crimping an annular flange  222  of the first housing portion  220  with an annular flange  232  of the second housing portion  230 . Of course, other fastening techniques such as welding, soldering, adhering, etc. may also be used to fasten the first and second housing portions  220 , 230 . The first housing portion  220  is shaped, preferably out of metal, in a single manufacturing operation, e.g., stamping. Of course, other materials and techniques may be used, including molding with a plastic material.  
     [0015] The fluid flow inlet  202  of the housing  200  is preferably located in the first housing portion  220 , and the fluid flow outlet  204  of the housing  200  is preferably located in the second housing portion  230 . The fluid flow inlet  202  can be a set of apertures (two apertures  202 A, 202 B are shown) penetrating the first housing portion  220 . The fluid flow outlet  204  can be a port penetrating the second housing portion  230 .  
     [0016] The divider  300 , which can include a diaphragm  320  and a seat  340 , is suspended in the housing  200 . Preferably, an outer perimeter  322  of the diaphragm  320  is sandwiched between the annular flanges  222 , 232  such that the divider  300  separates the interior volume  400  into the first and second chambers  410 , 420 . Preferably, the flange  222  is rolled over the circumferential edge of the flange  232  and then preferably crimped, as discussed above, so as to form the housing  200  and at the same time secure the diaphragm  320  with respect to the housing  200 .  
     [0017] A resilient calibrating element  600  biases the divider  300  against the closure member  500  at a predetermined force, which relates to the desired pressure at which the regulator  100  is to operate. The resilient calibrating element  600 , which is preferably a coil spring, may be located in the second chamber  420  by a locator  234  on the second housing portion  230 . The locator  234  may include a dimpled center portion that also provides the outlet  204 . The locator  234  positions a first end  610  of the resilient calibrating element  600 , while a second end  620  of the resilient calibrating element  600  is positioned with respect to the seat  340  by a seat retainer  342 . According to a preferred embodiment, the seat retainer  342  is secured to the seat  340  such that an inner perimeter  324  of the diaphragm  320  is sandwiched between the seat  340  and the seat retainer  342 .  
     [0018] The seat  340  is suspended in the housing  200  by the diaphragm  320  and provides the passage  302 . Preferably, the passage  302  extends along the longitudinal axis A between a first seat portion  344  and a second seat portion  346 . The first seat portion  344  is disposed in the first chamber  410  and the second seat portion  346  is disposed in the second chamber  420 . The first seat portion  342  provides a seating surface  348  that cooperates with the closure member  500 . In the manufacturing of the seat  340 , the seating surface  348  is finished to assure a smooth sealing surface for the closure member  500 .  
     [0019] Preferably, the closure member  500  includes a sphere  510  that is retained in a pocket  240  defined by a homogeneous shell  250 . The homogeneous shell  250  includes a first cylindrical portion  252 , a conical portion  254 , a second cylindrical portion  256 , an annular portion  260 , and a deformable portion  270 , all of which are preferably concentric about the longitudinal axis A. As it is used herein, the term “homogeneous” refers to a member that is formed completely from a single piece of material and therefore has material characteristics that are generally consistent throughout the entire member. As such, a homogeneous member according to the present invention incorporates a deformable portion that eliminates a separate retainer member that is necessary in a known flow-through pressure regulator to maintain the closure member within the pocket.  
     [0020] Referring additionally to FIG. 2, the annular portion  260  extends generally orthogonally with respect to the longitudinal axis A. An inner periphery  262  of the annular portion  260  is coupled to the first cylindrical portion  252 , which is coupled via the conical portion  254  to the second cylindrical portion  256 . The second cylindrical portion  256  and an endwall  258  occluding the second cylindrical portion  256  define a compartment that forms a portion of the pocket  240 . The conical portion  254  can support the sphere  510 , but does not prevent movement of the sphere  510 .  
     [0021] An outer periphery  264  of the annular portion  260  is coupled to the deformable portion  270 . Preferably, the deformable portion  270  is crimped or rolled-over a washer  530  of the closure member  500 . Thus, the washer  530  is captured between the deformable portion  270  and the annular portion  260 . The washer  530  has an inside diameter that is somewhat smaller than the diameter of the sphere ball  510  such that the sphere ball  510  cannot pass through the washer  530 . In turn, the crimped or rolled-over deformable portion  270  has an inside diameter that is less than an outside diameter of the washer  530  such that the washer  530  cannot pass through the deformable portion  270  of the shell  250 .  
     [0022] A resilient positioning element  540  biases the sphere  510  into engagement with the inside diameter of the washer  530 . Preferably, the resilient positioning element  540  is a coil spring that is received in the compartment defined by the second cylindrical portion  256  and the endwall  258 , and the inside diameter of the washer  530  includes a surface finish that provides smooth sliding contact with the sphere  510 .  
     [0023] Thus, the homogeneous shell  250  defines the pocket  240 , which receives the resilient positioning element  540 , the washer  530  and a majority of the sphere  510 . According to the present inventions, the shell  250  is displaced along the longitudinal axis A relative to the first housing part  220  so as to be press fitted with respect to the first housing portion  220 .  
     [0024] Referring additionally to FIG. 3, the first housing portion  220  includes a third cylindrical portion  224 , a fourth cylindrical portion  226  and an intermediate portion  228  coupling the third and fourth cylindrical portions  224 , 226 . Preferably, the third and fourth cylindrical portions  224 , 226 , as well as the intermediate portion  228 , are concentric about the longitudinal axis A. Preferably, the intermediate portion  228  is penetrated by the set of apertures  202 A, 202 B that define the fluid flow inlet  202  of the housing  200 . Preferably, the first cylindrical portion  252  is press fit with respect to the third cylindrical portion  224  so as to establish a fluid tight connection between the shell  250  and the first housing part  220 . The fourth cylindrical portion  226  may be press fitted into a mating socket (not shown) of a system for regulating fuel pressure.  
     [0025] Preferably, the first housing portion  220  and the shell  250  are formed out of metal in a single stamping operations. Of course, other materials and techniques may be used, including molding out of a plastic material.  
     [0026]FIGS. 2 and 3 show one set of preferred dimensions for the shell  250  and the first housing portion  220 , respectively.  
     [0027] One method of assembling the pressure regulator  100  is to 1) form, e.g., stamp, the first housing portion  220 , the shell  250  and the second housing portion  280 , 2) install the closure member  500  in the pocket  240  of the shell  250  (the sub-assembly of which is described in greater detail hereinafter), 3) press fit the shell  250  into the first chamber  410  of the first housing portion  220 , 4) install the resilient calibrating element  600  in the second chamber  420  of the second housing portion  230 , 5) assemble the divider  300 , and 6) assemble the first and second housing portions  220 , 230 , including sandwiching the outer perimeter  322  of the divider  300  between the first and second flanges  222 , 232 . According to the present invention, at least the shell  250  is formed from a single homogeneous member, e.g., a metal sheet.  
     [0028] Preferably, the closure member  500  is installed in the shell  250  by 1) installing the resilient positioning element  540  in the compartment defined by the second cylindrical portion  256  and the endwall  258 ; 2) installing the sphere  510  in the pocket  240 ; 3) installing the washer  530  over the sphere  510 ; and 4) crimping or rolling-over the deformable portion  270  so that the washer  530  is captured between the annular and deformable portions  260 , 270  of the shell  250 . Preferably, the washer  530  is captured loosely between the annular and deformable portions  260 , 270  such that it may float, e.g., is allowed a limited amount of longitudinal and radial motion with respect to the axis A. By virtue of being able to float, the washer  530  permits the sphere  510 , under the bias of the resilient positioning element  540 , to align with respect to the seating surface  348 .  
     [0029] Preferably, the divider  300  is assembled by installing the inner perimeter  324  of the diaphragm  320  on the seat  340 , so as to surround the passage  302 , and press fitting the seat retainer  342  onto the seat  340  so as to sealingly sandwich therebetween the inner perimeter  324 .  
     [0030] The resilient calibrating element  600  is installed in the second housing portion  230 . Preferably, the first end  610  of the resilient calibrating element  600  is positioned with respect to the locator  234  of the second housing portion  230 , and the second end  620  of the resilient calibrating element  600  is positioned with respect to the seat retainer  342 .  
     [0031] The first and second housing portions  220 , 230  are then matingly engaged. Preferably, the flange  222  of the first housing portion  220  is abutted against the flange  232  of the second housing portion  230 , and the flange  222  is crimped around the flange  232 . Of course, the flange  232  may alternatively be crimped around the flange  222 , or another coupling technique, e.g., welding or adhering, may be used to secure the first and second housing portions  220 , 230  with respect to one another.  
     [0032] The operation of the flow-through pressure regulator in a fuel system will now be described. The resilient calibrating element  600  acts through the seat retainer  342  to bias the divider  300  toward the closure member  500 . The resilient positioning element  540  biases the sphere  510  against the seating surface  348  of the seat  340 . In a first configuration, the sphere  510  is seated against surface  348  so as to prevent a flow of fuel through the pressure regulator  100 .  
     [0033] Fuel enters the regulator  100  through apertures  202 A, 202 B and exerts pressure on the divider  300 . When the force of the fuel pressure acting on the divider  300  is greater than the force exerted by the resilient calibrating element  600 , the diaphragm  320  flexes so as to allow the seat  340  to move along the longitudinal axis A, and the sphere  510  separates from the seating surface  348  of the seat  340 . This is a second configuration that permits the flow of fuel through inlet  202 , into the first chamber  410 , between the sphere  510  and the seat  340 , through the passage  302  into the second chamber  420 , and through the outlet  204 . Selection of the resilient calibrating element  600 , and more particularly the force exerted by the resilient calibrating element  600  on the divider  300 , determines the fuel pressure level at which pressure regulation, i.e., the transition between the first and second configurations, occurs in the pressure regulator  100 .  
     [0034] A closure member assembly that is assembled into a homogeneous shell, according to the present invention, allows the resilient positioning element, the sphere, and the washer to be captured without a separate retainer assembly for the closure member, and eliminates an additional piece and assembly step.  
     [0035] A shell that is press-fit into a housing, according to the present invention, eliminates the need to machine a ball pocket, as well as the staking operations that were necessary in known flow-through pressure regulators. Thus, the present invention simplifies the manufacture and provides a more cost-effective way of assembling a flow-through pressure regulator.  
     [0036] 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.