Patent Publication Number: US-7219658-B2

Title: Fuel feed apparatus having pump and stay

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
   This application is based on and incorporates herein by reference Japanese Patent Application No. 2004-291195 filed on Oct. 4, 2004. 
   FIELD OF THE INVENTION 
   The present invention relates to a fuel feed apparatus that supplies fuel in a fuel tank to the outside of the fuel tank. 
   BACKGROUND OF THE INVENTION 
   Conventionally, a fuel feed apparatus has a fuel pump that is accommodated in a fuel tank. The fuel feed apparatus includes a flange that covers an opening of the fuel tank. The fuel pump is supported by the flange via a stay. The stay has an axial end that is press-inserted into a hole formed in the flange, for example. 
   A fuel feed apparatus disclosed in U.S. Pat. No. 5,992,394 (JP-A-11-101166) includes a sub-tank that accommodates a fuel pump. A stay connects the sub-tank with the flange. In this structure, the sub-tank is pressed onto a bottom wall of a fuel tank, so that the sub-tank is not apt to be twisted with respect to the flange. Therefore, force applied to the stay in the circumferential direction thereof becomes small. 
   However, when a pump is suspended from a flange into a fuel tank, or when force pressing a sub-tank onto a bottom wall of a fuel tank is small, the flange may be twisted with respect to the fuel pump in a fuel feed apparatus. Specifically, a stay connecting the flange with the sub-tank is substantially circular in cross section, and the flange has a circular hole, into which the stay is press-inserted. Accordingly, when the flange is twisted relative to the fuel pump, the stay circumferentially is rotated in the hole of the flange. 
   It is conceived to provide an additional component such as a pin or a ring to restrict rotation of the stay. However, when an additional component is provided, the number of components and manpower for assembling the fuel feed apparatus increases. 
   SUMMARY OF THE INVENTION 
   In view of the foregoing and other problems, it is an object of the present invention to produce a fuel feed apparatus, in which a stay is restricted from circumferentially rotating, without increasing a number of components and manpower for assembling the fuel feed apparatus. 
   According to one aspect of the present invention, a fuel feed apparatus includes a flange, a fuel pump, and at least one stay. The flange covers an opening of a fuel tank. The fuel pump is accommodated in the fuel tank. The fuel pump pumps fuel in the fuel tank to an outside of the fuel tank. The at least one stay has a first end, which connects with the flange. The at least one stay has a second end. The at least one stay supports the fuel pump in the fuel tank on the side of the second end. The flange has a hole portion on a side of the fuel pump. The hole portion of the flange receives the first end of the at least one stay. The first end of the at least one stay is located on an opposite side of the fuel pump. The first end received in the hole portion has a rotation restricting portion that restricts the at least one stay from rotating in a circumferential direction of the at least one stay. 
   The rotation restricting portion has a cross section, which is perpendicular to an axis of the at least one stay. The cross section of the rotation restricting portion is in a noncircular shape. The hole portion has a cross section that is substantially similar to the cross section of the rotation restricting portion. The cross section of the rotation restricting portion may be in a substantially oblong shape that has two sides, which are substantially in parallel with each other. The cross section of the rotation restricting portion may be in a substantially D-shape that is formed of an arc and a substantially straight line. Alternatively, the cross section of the rotation restricting portion may be in a substantially rectangular shape that is formed of two pairs of two sides, which are opposed to each other. In this case, the two sides, which are opposed to each other, are substantially in parallel with each other. 
   Therefore, the at least one stay is restricted from rotating by the rotation restricting portion, even when circumferential force acts onto the at least one stay. Thus, the at least one stay can be restricted from circumferentially rotating without providing an additional component. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The above and other objects, features and advantages of the present invention will become more apparent from the following detailed description made with reference to the accompanying drawings. In the drawings: 
       FIG. 1  is a side view showing a fuel feed apparatus according to a first embodiment of the present invention; 
       FIG. 2A  is a partially cross sectional side view showing a press-inserted portion of the fuel feed apparatus, and  FIG. 2B  is a partially cross sectional bottom view taken along the line IIB—IIB in  FIG. 2A , according to the first embodiment; 
       FIG. 3  is a top view showing the fuel feed apparatus according to the first embodiment; 
       FIG. 4  is a partially cross sectional side view showing the press-inserted portion and a stay of the fuel feed apparatus, according to the first embodiment; 
       FIG. 5A  is a partially cross sectional bottom view taken along the line VA—VA in  FIG. 4 , and  FIG. 5B  is a partially cross sectional top view taken along the line VB—VB in  FIG. 4 , according to the first embodiment; 
       FIG. 6A  is a partially cross sectional bottom view showing a press-inserted portion of a fuel feed apparatus, and  FIG. 6B  is a partially cross sectional top view showing a tip end of a stay, according to a second embodiment of the present invention; 
       FIG. 7A  is a partially cross sectional bottom view showing a press-inserted portion of a fuel feed apparatus, and  FIG. 7B  is a partially cross sectional top view showing a tip end of a stay, according to a third embodiment of the present invention; 
       FIG. 8  is a side view showing a tip end of a stay of a fuel feed apparatus, according to a fourth embodiment of the present invention; and 
       FIG. 9A  is a top view showing a tip end of a stay of a fuel feed apparatus, and  FIG. 9B  is a side view showing the tip end of the stay, according to a fifth embodiment of the present invention. 
   

   DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
   (First Embodiment) 
   As shown in  FIG. 1 , a fuel feed apparatus  10  has a flange  11 , which is formed in a circular disc-shape. The flange  11  is mounted to an upper wall of the fuel tank  1 , so that the flange  11  covers an opening  2  formed in the fuel tank  1 . Components of the fuel feed apparatus excluding the flange  11  is accommodated in the fuel tank  1 . The flange  11  includes a discharge pipe  12  and an electric connector  13 . 
   The components of the fuel feed apparatus  10  accommodated in the fuel tank  1  include a fuel pump  20 , a fuel filter  21 , a pressure regulator  22 , and a suction filter  23 . The fuel pump  20  is directly accommodated in the fuel tank  1 . The fuel pump  20  draws fuel in the fuel tank  1 . The fuel pump  20  accommodates a motor (not shown). The fuel pump  20  is energized, and the motor rotates an impeller (rotating member, not shown), so that suction force is generated to draw fuel in the fuel tank  1 . Fuel discharged from the fuel pump  20  passes through the fuel filter  21 . The fuel passing through the fuel filter  21  is controlled in pressure through the pressure regulator  22 , subsequently the fuel is introduced to the outside of the fuel tank  1  though a bellows pipe  24  and a discharge pipe  12 . The electric connector  13  connects with the fuel pump  20  via a lead wire  14 . 
   The fuel filter  21  is arranged on the radially outer side of the fuel pump  20 . The fuel filter  21  circumferentially covers the fuel pump  20 . A suction filter  23  is provided on the suction side of the fuel pump  20 . The suction filter  23  removes relatively large debris contained in fuel drawn into the fuel pump  20 . The fuel filter  21  removes relatively small debris contained in fuel discharged from the fuel pump  20 . A bracket  25  supports the fuel pump  20  from the lower side in  FIG. 2 . 
   The fuel filter may not be provided on the discharge side of the fuel pump  20 . For example, when filtering performance of the suction filter  23  is improved to be capable of removing relatively small debris, the fuel filter  21  may be reduced. 
   The fuel feed apparatus  10  includes a case  30  that accommodates the fuel pump  20  and the fuel filter  21 . The case  30  includes substantially cylindrical connecting portions  31  that respectively protrude outwardly from the case  30  in the radial direction of the case  30 . 
   As shown in  FIG. 3 , two of the connecting portions  31  are provided to the case  30  at two locations. An imaginary straight line, which connects the two connecting portions  31  is out of the center of the case  30 , so that the connecting portions  31  are arranged at locations that are eccentric with respect to the case  30 . As referred to  FIG. 1 , each connecting portion  31  has a hole portion  32  that axially penetrates the connecting portion  31 . 
   Each stay  40  is formed in a bar shape. The stay  40  is formed of metal such as stainless steel and aluminum, or is formed of a non-metallic material such as resin. The stay  40  connects with the flange  11  and the case  30 . The fuel pump  20  accommodated in the case  30  is supported by the flange  11  via two of the stays  40 , so that the fuel pump  20  is suspended from the flange  11  into the fuel tank  1  via the stays  40 . Each stay  40  has one end (first end) that is press-inserted into a press-inserted portion  15  of the flange  11 . The stay  40  has the other end (second end) on the opposite side of the flange  11 . The other end of the stay  40  extends into the fuel tank  1 , so that the other end of the stay  40  is inserted into the hole portion  32  of the connecting portion  31 . 
   As referred to  FIG. 1 , the connecting portion  31  has two axial ends, to which rings  33  are respectively provided. Each ring  33  is formed of an elastic material such as oil-proof rubber. The ring  33  is formed in a substantially cylindrical shape, into which the stay  40  is inserted. The stay  40  has a washer  34  on the axial end thereof on the side opposite to the flange  11 . The stay  40  is inserted into the connecting portion  31 , and is attached with the ring  33 . The stay  40  is attached with the washer  34  on the axial end thereof, so that the stay  40  is supported by the case  30  that accommodates the fuel pump  20 . 
   The fuel feed apparatus  10  includes a sender gauge  60  that detects a liquid level of fuel in the fuel tank  1 . The sender gauge  60  is accommodated in the fuel tank  1  together with the fuel pump  20 . The sender gauge  60  is supported by the stay  40 . The sender gauge  60  includes a body  61 , a detecting portion  62 , an arm  63 , and a float  64 . The body  61  includes arm portions  65 ,  64  that respectively extend to the outer side. The ends of the arm portions  65 ,  64  respectively engage with the stays  40 . 
   The detecting portion  62  is arranged in the body  61 , such that the detecting portion  62  rotatably supports the arm  63 . The detecting portion  62  has a circuit pattern (not shown) that makes contact with the arm  63 . The float  64  is provided to the end of the arm  63  on the opposite side of the detecting portion  62 . The float  64  floats in fuel received in the fuel tank  1 . The float  64  vertically moves corresponding to the liquid level of fuel in the fuel tank  1 , so that the arm  63  rotates around the detecting portion  62 . Thus, a condition of contact between the arm  63  and the detecting portion  62  changes, so that the liquid level of fuel is detected. 
   Multiple pipes  26  respectively cover the outer peripheries of the stays  40 . The pipes  26  are respectively provided among the connecting portions  31  of the case  30 , the arm portions  65 ,  66  of the body  61 , and the flange  11 . Each pipe  26  serves as a spacer that restricts the distances among the connecting portion  31 , the body  61 , and the flange  11 . 
   Next, the connecting portion between the flange  11  and each stay  40  is described in detail. As shown in  FIGS. 2A ,  2 B, the flange  11  has the press-inserted portion  15  that protrudes to the side of the fuel pump  20 . That is, the press-inserted portion  15  protrudes to the side of the inside of the fuel tank  1 . 
   As show in  FIGS. 4 ,  5 A, and  5 B, the press-inserted portion  15  is formed in a substantially cylindrical shape that has a hole portion  16 , into which each stay  40  is press-inserted. The stay  40  has a tip end  41  and a rotation restricting portion  42  on the side of the flange  11 . The tip end  41  and the rotation restricting portion  42  protrude from a column portion  43  to the side of the flange  11 . The column portion  43  has a substantially constant outer diameter thereof, and constructs a large part of the stay  40 . The tip end  41  of the stay  40  is formed in a stepwise shape, so that the end  41  introduces the stay  40  into the hole portion  16 . 
   The rotation restricting portion  42  is arranged between the column portion  43  and the tip end  41 . The tip end  41 , the rotation restricting portion  42 , and the column portion  43  are integrally formed to construct the stay  40 . 
   As referred to  FIG. 5B , the rotation restricting portion  42  has the cross section perpendicular to the axis of the rotation restricting portion  42 . The cross section of the rotation restricting portion  42  is in a noncircular shape. Specifically, the axial cross section of the rotation restricting portion  42  is in a substantially oblong shape or a substantially oval shape. More specifically, the rotation restricting portion  42  has two flat faces  42   a  on both radially outer side thereof. The two flat faces  42   a  are substantially in parallel with each other. The rotation restricting portion  42  has two arc-shaped faces  42   b  that connects the two flat faces  42   a.    
   As referred to  FIG. 5A , the hole portion  16  of the flange  11  has the cross section that is in a substantially similar figure with respect to the axial cross section of the stay  40 . That is, the cross section of the hole portion  16  is analogous to the axial cross section of the stay  40 , i.e., the cross section of the hole portion  16  is geometrically similar to the axial cross section of the stay  40 . 
   That is, the hole portion  16  of the flange  11  has the axial cross section that is in a noncircular shape such as an oblong shape and an oval shape. The flange  11  has the inner wall, which defines the hole portion  16 . The inner wall of the flange  11  includes two flat faces  16   a  on both radially outer side thereof. The two flat faces  16   a  are substantially in parallel with each other. The inner wall of the flange  11  has two arc-shaped faces  16   b  that connects the two flat faces  16   a . In a structure, in which the stay  40  is press-inserted into the press-inserted portion  15 , the axial cross sectional area of the hole portion  16  of the flange  11  is substantially equal to or less than the axial cross sectional area of the rotation restricting portion  42  of the stay  40 . 
   In a structure, in which the stay  40  is loosely inserted into the press-inserted portion  15 , the axial cross sectional area of the hole portion  16  of the flange  11  may be greater than the axial cross sectional area of the rotation restricting portion  42  of the stay  40  such that the rotation restricting portion  42  of the stay  40  do not rotate in the press-inserted portion  15 . 
   When the stay  40  is press-inserted into the hole portion  16 , each flat face  42   a  of the rotation restricting portion  42  tightly makes contact with each flat face  16   a  of the hole portion  16 . Thus, the stay  40  is press-inserted into the hole portion  16 . That is, the flat face  42   a  of the rotation restricting portion  42  and the flat face  16   a  of the hole portion  16  serve press-insertion faces. The arc-shaped face  42   b  of the rotation restricting portion  42  and the arc-shaped face  16   b  of the hole portion  16  do not exert influence to the press-insertion. The stay  40  is press-inserted into the press-inserted portion  15 , so that the stay  40  connects to the flange  11 . 
   The stay  40  is press-inserted into the flange  11 , so that the flat face  42   a  of the rotation restricting portion  42  tightly makes contact with the flat face  16   a  of the hole portion  16 , after the press-insertion. The rotation restricting portion  42  and the hole portion  16  respectively have cross sections that are in noncircular shapes. Therefore, even force is applied to the stay  40  to rotate the stay  40  in the circumferential direction, the stay  40  is restricted from rotating with respect to the flange  11  by the contact between the flat face  42   a  of the rotation restricting portion  42  and the flat face  16   a  of the hole portion  16 . 
   In this first embodiment, as referred to  FIG. 3 , the imaginary straight line, which connects the connecting portions  31  of the case  30  therebetween, departs from the center of the case  30  that accommodates the fuel pump  20 . Therefore, an imaginary straight line that connects the two stays  40  is away from the center of the case  30 , which accommodates the fuel pump  20 , and the center of the flange  11 . Thus, the two stays are arranged eccentrically with respect to the fuel pump  20  and the flange  11 . Here,  FIG. 3  is a schematic view for briefly explaining the structure, in which the stays  40  are eccentrically arranged relative to the case  30 . Components of the fuel feed apparatus  10  such as the discharge pipe  12 , the electric connecter  13 , and the sender gauge  60  are not depicted in  FIG. 3 . The shape of components of the fuel feed apparatus  10  are simplified in  FIG. 3 , and details of the fuel feed apparatus  10  are not specifically depicted in  FIG. 3 . 
   The two stays  40  are arranged eccentrically with respect to the fuel pump  20  and the flange  11 , so that torsion arising between the flange  11  and the case  30 , which accommodates the fuel pump  20 , are allowed in a predetermined range. Therefore, even when the flange  11  is twisted with respect to the case  30 , the twist is absorbed by eccentricity among the stays  40 , the flange  11  and the case  30 . As a result, even when the flange  11  is twisted with respect to the case  30 , the rotative force applied to the end of the stays  40  on the side of the flange  11  becomes small. Therefore, the stays  40  can be restricted from rotating in the circumferential direction thereof. 
   When the case  30 , which receives the fuel pump  20 , is suspended from the flange  11  via the stays  40  in the fuel feed apparatus  10  in this embodiment, torsion is apt to arise between the flange  11  and the case  30 . When torsion arises, force is applied to a base portion of the stays  40 , i.e., to the ends of the stays  40  on the side of the flange  11 . As a result, the stays  40  are respectively rotated in the circumferential direction thereof. By contrast, in this embodiment, each stay  40  has the rotation restricting portion  42  that restricts the stay  40  from rotating relative to the press-inserted portion  15  of the flange  11 . Therefore, the stays  40  are restricted from rotating by the rotation restricting portion  42 , even when circumferential force acts onto the stays  40 . Thus, the stays  40  can be restricted from rotating without using an additional member. 
   In this embodiment, the flat faces  42   a  and the flat faces  16   a  are formed in the rotation restricting portion  42  of each stay  40  and each hole portion  16  of the flange  11 . Therefore, press-insertion between the stay  40  and the flange  11  is maintained by a large force caused by contact between the flat faces  42   a  and the flat faces  16   a . Thus, the stay  40  can be steadily restricted from rotating in the circumferential direction thereof. That is, the stay  40  can be steadily restricted from rotating around the longitudinal axis of the stay  40 . 
   (Second and Third Embodiments) 
   In the second and third embodiments, the cross sectional shapes of the rotation restricting portions of the stays  40  and the hole portions of the flange  11  are different from those in the first embodiment. 
   In the second embodiment, as shown in  FIG. 6B , the rotation restricting portion  42  has the axial cross sectional shape that is in a substantially D-shape. Specifically, the rotation restricting portion  42  of the stay  40  has one flat face  42   c  and an arc face  42   d . The arc face  42   d  connects both end portions of the flat face  42   c . As shown in  FIG. 6A , the hole portion  16  of the flange  11  has the axial cross section that is a similar figure with respect to the axial cross section of the rotation restricting portion  42  of the stay  40 . Specifically the hole portion  16  of the flange  11  has one flat face  16   c  and an arc face  16   d . The arc face  16   d  connects both end portions of the flat face  16   c.    
   In the second embodiment, the rotation restricting portion  42  of the stay  40  and the hole portion  16  of the flange  11  respectively have one flat face  42   c  and one flat face  16   c . Therefore, press-insertion between the stay  40  and the flange  11  is maintained by a large force caused by contact between the flat face  42   c  and the flat face  16   c . Besides, the stay  40  is restricted from rotating by contact between the flat face  42   c  and the flat face  16   c . Thus, the stay  40  can be steadily restricted from rotating in the circumferential direction thereof. 
   In the third embodiment, as shown in  FIG. 7B , a rotation restricting portion  44  has the axial cross sectional shape that is in a substantially rectangular shape. Specifically, the rotation restricting portion  44  of the stay  40  has two pairs of flat faces  44   a . That is, the rotation restricting portion  44  has four flat faces  44   a . The flat faces, which are opposite to each other, are substantially parallel to each other. As shown in  FIG. 7A , a hole portion  17  of the flange  11  has the axial cross section that is a similar figure with respect to the axial cross section of the rotation restricting portion  44  of the stay  40 . Specifically the hole portion  17  of the flange  11  has four flat faces  17   a.    
   In the third embodiment, the rotation restricting portion  44  of the stay  40  and the hole portion  17  of the flange  11  respectively have the four flat faces  44   a  and the four flat faces  17   a . Therefore, press-insertion between the stay  40  and the flange  11  is maintained by a large force caused by contact between the four flat faces  44   a  and the four flat faces  17   a . Besides, the stay  40  is restricted from rotating by contact between the flat faces  44   a  and the flat faces  17   a . Thus, the stay  40  can be steadily restricted from rotating in the circumferential direction thereof. That is, in the above first to the third embodiments, the stay  40  can be steadily restricted from rotating around the longitudinal axis of the stay  40 . 
   As described in the above first to the third embodiments, a substantially oblong shape, a substantially D-shape, and a substantially rectangular shape are applied to the cross sectional shapes of the rotation restricting portions  42 ,  44  and the hole portions  16 ,  17  as examples. However, the axial cross sectional shapes are not limited to the above shapes. Any noncircular shapes such as a polygonal shape, a star-shape, and an oval shape may be applied to the cross sectional shapes of the rotation restricting portions  42 ,  44  and the hole portions  16 ,  17 . 
   (Fourth and Fifth Embodiments) 
   In the fourth and fifth embodiments, the cross sectional shapes of the rotation restricting portions of the stays  40  and the hole portions of the flange  11  are different from those in the first to third embodiments. In the structures of the fourth and fifth embodiments, the axial cross sectional shapes of the hole portions of the flange  11  may be a circular shape similarly to a conventional structure. 
   As shown in  FIG. 8 , in the fourth embodiment, each stay  40  has a rotation restricting portion  45  that has protruding portions  451 . When the stay  40  is press-inserted into the press-inserted portion  15  of the flange  11 , the protruding portions  451  dig into the inner wall of the press-inserted portion  15  of the flange  11  that internally forms the hole portion, into which the stay  40  is press-inserted. The protruding portions  451  include multiple protrusions, which are in splinter (thorn) shapes, regularly or irregularly formed on the rotation restricting portion  45 , so that multiple protruding portions  451  are formed on the rotation restricting portion  45 . 
   In the fourth embodiment, the protruding portions  451  are formed on the rotation restricting portion  45 , so that the protruding portions  451  dig into the inner wall of the press-inserted portion  15  of the flange  11  when the stay  40  is press-inserted into the press-inserted portion  15  of the flange  11 . The touch area between the stay  40  and the flange  11  increases, so that friction is enhanced between the stay  40  and the flange  11 . Thereby, the stay  40  is restricted from moving in the circumferential direction thereof. Thus, the stay  40  can be restricted from circumferentially rotating. 
   As shown in  FIG. 9 , in the fifth embodiment, each stay  40  has a rotation restricting portion  46  that has protruding portions  461 . When the stay  40  is press-inserted into the press-inserted portion  15  of the flange  11 , the protruding portions  461  dig into the inner wall of the press-inserted portion  15  of the flange  11  that internally forms the hole portion, into which the stay  40  is press-inserted. The protruding portions  461  are formed on the rotation restricting portion  46  along the circumferential direction in a discontinuous manner. Thereby, the protruding portions  461  radially outwardly protrude from the rotation restricting portion  46 . The protruding portions  461  are formed on the rotation restricting portion  46  axially throughout the lengthwise direction of the rotation restricting portion  46 . 
   The protruding portions  461  may be partially formed on the rotation restricting portion  46  axially with respect to the lengthwise direction of the rotation restricting portion  46 . The protruding portions  461  may be formed on the rotation restricting portion  46  axially with respect to the lengthwise direction of the rotation restricting portion  46  in a discontinuous manner. 
   The protruding portions  461  are not limited to be formed on the rotation restricting portion  46  regularly in the circumferential direction thereof. The protruding portions  461  may be formed on the rotation restricting portion  46  irregularly in the circumferential direction thereof. 
   In the fifth embodiment, the protruding portions  461  are formed on the rotation restricting portion  46 , so that the protruding portions  461  dig into the inner wall of the press-inserted portion  15  of the flange  11  when the stay  40  is press-inserted into the press-inserted portion  15  of the flange  11 . Thus, the touch area between the stay  40  and the flange  11  increases, so that friction is enhanced between the stay  40  and the flange  11 . Thereby, the stay  40  is restricted from moving in the circumferential direction thereof. Thus, the stay  40  can be restricted from circumferentially rotating. In the above fourth and fifth embodiments, the stay  40  can be steadily restricted from rotating around the longitudinal axis of the stay  40 . 
   The shape and structure of the protruding portion are not limited to the above shape and structure. The protruding portion may have any shapes and structures, in which the protruding portion dig into the inner wall of the press-inserted portion of the flange when the stay is press-inserted into the press-inserted portion of the flange. 
   (Variation) 
   The above structures of the present invention may be applied to a fuel feed apparatus that includes a sub-tank having a bottom portion making contact with a bottom wall of a fuel tank. 
   The structures and methods of the above embodiments can be combined as appropriate. For example, the fourth and fifth embodiments can be combined to form a combined protruding portion on the rotation restricting portion of the stay. 
   Various modifications and alternations may be diversely made to the above embodiments without departing from the spirit of the present invention.