Patent Publication Number: US-7909021-B2

Title: Fuel damper fixing clip

Description:
This application claims priority under 35 U.S.C. §119 to Japanese Patent Application No. 2007-211822, filed on Aug. 15, 2007, which is incorporated by reference herein in its entirety. 
     FIELD OF THE INVENTION 
     The present invention relates generally to a fuel damper fixing clip for fixing a diaphragm type fuel damper to a cup portion which opens in communication with a fuel pipe in an internal combustion engine. 
     BACKGROUND OF THE INVENTION 
     A related art clip is formed from a sheet member in a U-shape, as a clip for fixing the base end of a fuel injection valve to a fuel pipe in an internal combustion engine. In this arrangement, after the clip is attached to the fuel injection valve, they are mounted on a fuel pipe together. 
     However, while the related art clip is used to fix the base end of the fuel injection valve to the fuel pipe, the distal end of the fuel injection valve is fixed to an intake manifold (or cylinder head). Thus, the clip for fixing the fuel injection valve to the fuel pipe is not required to have so much holding force. Accordingly, the clip is formed in the U-shape and arranged so that it can be easily removed. 
     In contrast, in a clip for fixing a fuel damper to a fuel pipe, the fuel damper is fixed only to the fuel pipe and is not fixed to any other portion. Thus, the clip must securely fix the fuel damper so that it does not fall off. 
     From the above point of view, since the related art U-shaped clip does not have sufficient holding force, there is a possibility that the clip is loosened (deformed) and falls off when an excessively large force is applied thereto. Thus, the clip cannot be applied to the fuel damper fixing clip. 
     In view of the above circumstances, an object of the present invention is to provide a fuel damper fixing clip which can easily fix a fuel damper and will not fall off. 
     SUMMARY OF THE INVENTION 
     In an embodiment, the invention provides a fuel damper fixing clip for fixing both a collar portion around the outer periphery of an open end of a cup portion and a collar portion around the outer periphery of an intermediate portion of a diaphragm type fuel damper in a state such that a head portion of the fuel damper is engaged in the cup portion. The cup portion is in communication with a fuel pipe for supplying fuel to an internal combustion engine. The collar portion of the cup portion is joined to the collar portion of the fuel damper. The fuel damper fixing clip includes a clip main body formed from a sheet member having a plurality of flat portions, and formed in a generally square cylindrical shape. The clip main body surrounds portions of the outer peripheries of the cup portion and the fuel damper and deforms in a tightening direction. The clip main body includes two ends overlapped on an outside and an inside surface thereof. Slits are disposed in the plurality of flat portions of the clip main body, and the collar portions of the cup portion and the fuel damper are disposed therein and locked in a diameter-reduced state of the clip main body in which the clip main body is tightened. A receiving hole is formed in one of the ends of the clip main body. A claw portion is disposed on the other end of the clip main body obliquely projecting in a direction opposite to the tightening direction. The claw portion is disposed in the receiving hole in the diameter-reduced state in which the clip main body is tightened, and locks the clip main body in the diameter-reduced state in which the collar portions are fixed. 
     In another embodiment, the invention provides a method of fixing both a collar portion around the outer periphery of an open end of a cup portion and a collar portion around the outer periphery of an intermediate portion of a diaphragm type fuel damper in a state such that a head portion of the fuel damper is engaged in the cup portion and the collar portion of the cup portion is joined to the collar portion of the fuel damper. The cup portion is in communication with a fuel pipe for supplying fuel to an internal combustion engine. The method includes providing a fuel damper fixing clip having a clip main body formed from a sheet member having a plurality of flat portions and formed in a generally square cylindrical shape, slits disposed in the plurality of flat portions of the clip main body, a receiving hole formed in one end of the clip main body, and a claw portion disposed on another end of the clip main body obliquely projecting in a direction opposite to a tightening direction. The method further includes surrounding portions of the outer peripheries of the cup portion and the fuel damper with the clip main body, disposing the collar portions of the cup portion and the fuel damper in the slits, overlapping the two ends of the clip main body on an outside and an inside surface thereof, deforming the clip main body in a tightening direction in a diameter-reduced state, disposing the claw portion in the receiving hole in the diameter-reduced state in which the clip main body is tightened, and locking the clip main body in the diameter-reduced state in which the collar portions are fixed. 
     According to the present invention, since the clip is wound and tightened from the entire periphery thereof and held by the slits, it can be securely fixed. Further, since the claw portion enters into the receiving hole in a diameter-reduced state in which the clip is wound and tightened and locks the return of the clip, the claw portion can be securely fixed. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are incorporated herein and constitute part of this specification, illustrate the 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  is a perspective view showing the state in which fuel dampers are attached to fuel pipes; 
         FIG. 2  is an exploded view showing an attachment structure for attaching the fuel damper to the fuel pipe; 
         FIG. 3  is an assembly view showing an attachment structure for attaching the fuel damper to the fuel pipe, before a winding and tightening operation is performed; 
         FIG. 4  an assembly view showing an attachment structure for attaching the fuel damper to the fuel pipe, after the winding and tightening operation is performed; 
         FIG. 5  is a perspective view of a clip; 
         FIGS. 6A and 6B  respectively show a schematic plan view and a schematic lateral sectional view of the clip in a diameter-enlarged state (open state) before it is subjected to the winding and tightening operation; 
         FIGS. 7A and 7B  respectively show a schematic plan view and a schematic lateral sectional view of the clip while it is being subjected to the winding and tightening operation; 
         FIGS. 8A and 8B  respectively show a schematic plan view and a schematic lateral sectional view of the clip in a diameter-reduced state (closed state) after it is subjected to the winding and tightening operation; and 
         FIG. 9  is a fragmentary view taken in the direction of arrow A in  FIG. 8A . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       FIG. 1  shows fuel pipes of an internal combustion engine in an embodiment of the present invention. The fuel pipes are employed in a V-type six-cylinder engine. The fuel pipes (fuel gallery)  1  are disposed at respective banks and communicate with each other through a fuel tube  2  and are connected to a fuel tube  4  from a fuel pump (not shown) through connectors  3 . 
     The base ends of each of three sets of fuel injection valves  5  are attached to a respective fuel pipe  1 , as is a fuel damper  10 . An assembly of the fuel pipes  1 , the fuel injection valves  5 , and the fuel dampers  10  is mounted on the engine, and the distal ends of the fuel injection valves  5  are attached to the intake manifolds of the engine. 
       FIGS. 2 to 4  show an attachment structure for attaching the fuel damper to the fuel pipe, wherein  FIG. 2  is an exploded view,  FIG. 3  is an assembly view before a winding and tightening operation is performed, and  FIG. 4  is an assembly view after the winding and tightening operation is performed.  FIG. 1  shows the state when the fuel pipes are mounted on the engine, whereas  FIGS. 2 to 4  show the state when the fuel dampers are attached to the fuel pipes, and thus the view of  FIG. 1  is upside down with respect to those of  FIGS. 2 to 4 . 
     Referring to  FIG. 2 , a cup portion  6  is exposed to an inside of the fuel pipe  1  so as to open in communication with the fuel pipe  1 . Although the cup portion  6  opens downward in the state that the fuel pipe  1  is mounted on the engine, the fuel damper  10  is attached to the cup portion  6  in the state that it opens upward. 
     An O ring  7  is attached around the inner periphery of the cup portion  6 . Further, a collar portion  8  is disposed around the outer periphery of the opening end of the cup portion  6 . The fuel damper  10  has an upper case  11 , a lower case  12  (a case located on an upper side when it is mounted on the engine is called the upper case, and a case located on a lower side when it is mounted on the engine is called the lower case), and a collar portion  13  around the outer periphery of an intermediate portion of the fuel damper  10  which acts as a joint portion of the upper case  11  and the lower case  12 . A fuel chamber  15  on the upper case  11  side and an air chamber  16  on the lower case  12  side are separated by a diaphragm  14 , a peripheral edge portion of which is clamped in the joint portion. A fuel introduction port  16  to the fuel chamber  15  is formed in the upper case  11 . A spring  17  is accommodated in the air chamber  16  of the lower case  12  to urge the diaphragm  14  to the fuel chamber  15  side. 
     When the pressure of the fuel introduced into the fuel chamber  15  is increased, the fuel damper  10  operates to suppress the variation of fuel pressure in such a manner that the diaphragm  14  is displaced to the air chamber  16  side, and increasing the volume of the fuel chamber  15 . 
     The upper case  11 , which is the head portion of the fuel damper  10 , is engaged in the cup portion  6  on the fuel pipe  1  side so that the collar portion  8  around the outer periphery of the opening end of the cup portion  6  is joined to the collar portion  13  around the outer periphery of the intermediate portion of the fuel damper  10  as shown in  FIG. 3 . A resin backup ring  18  is attached to the fuel damper  10  and abutted against the O ring  7 . 
     A fuel damper fixing clip (clip main body)  20  is used to fix the collar portion  8  on the cup portion  6  side to the collar portion  13  on the fuel damper  10  side in this state.  FIG. 3  shows the state that the clip  20  is set, and  FIG. 4  shows the state that the collar portions  8 ,  13  are fixed by the clip  20 . 
     It is sufficient for the clip  20  to cause the O ring  7  to function to prevent the fuel damper  10  from falling off from the cup portion  6 . Accordingly, it is sufficient for the clip  20  to regulate the amount of movement of the fuel damper  10  in an axial direction, and it is not necessary for the clip  20  to cause the fuel damper  10  not to move at all. Therefore, even if the fuel damper  10  rotates, no problem occurs in the performance thereof. However, to prevent the unnecessary rotation of the fuel damper  10 , the rotation thereof is regulated by a cutout  33  disposed on the main body of the clip  20  and a projection  9  disposed on the cup portion  6  (refer to  FIG. 2 , in which they are dislocated from each other 90°). 
     A structure of the fuel damper fixing clip  20  will be explained below in detail.  FIG. 5  is a perspective view of the clip.  FIGS. 6A and 6B  respectively are a schematic plan view and a schematic lateral sectional view of the clip in a diameter-enlarged state (open state) before it is subjected to a winding and tightening operation.  FIGS. 7A and 7B  respectively are a schematic plan view and a schematic lateral sectional view of the clip while it is being subjected to the winding and tightening operation.  FIGS. 8A and 8B  respectively are a schematic plan view and a schematic lateral sectional view of the clip in a diameter-reduced state (closed state) after it is subjected to the winding and tightening operation. The clip in any of the views is observed from a bottom surface side (from a lower side in the state that it is mounted on the engine).  FIG. 9  is a fragmentary view of  FIG. 8  when the clip is observed from arrow A. 
     The main body of the clip  20  is formed of a sheet member which is bent and formed in a generally square cylindrical shape so as to have a plurality of (at least three) flat portions  21 . With this configuration, the main body of the clip  20  covers the outer peripheries of the cup portion  6  and the fuel damper  10 , and can be deformed in a winding and tightening direction, and the surfaces thereof at both the ends (arc-shaped overlapping surfaces  22 ,  23 ) are overlapped on an inside and an outside. 
     Slits  24  are formed in the three flat portions  21  of the main body of the square cylindrical clip  20  so that the collar portions  8 ,  13  of the cup portion  6  and the fuel damper  10  may enter into the slits  24  and be locked in the diameter-reduced state of the clip  20  in which it is wound and tightened. Accordingly, the slits  24  are disposed at three positions in a peripheral direction. 
     The abutment sides of the slits  24  against which the collar portion  13  of the fuel damper  10  is abutted have bent surfaces  25  bent inward, and the collar portion  13  of the fuel damper  10  is abutted against the slits  24  at the bent surfaces  25 . A receiving hole  26  is formed in one of the arc-shaped overlapping surfaces  22  and  23  of the main body of the clip  20  (here, the outside overlapping surface  22 ). 
     A claw portion  27  is disposed on the other overlapping surface (here, the inside overlapping surface  23 ) so as to obliquely project in a direction opposite to the winding and tightening direction on the overlapping surface  22  side. The claw portion  27  enters into the receiving hole  26  in the diameter-reduced state of the clip  20  in which it is wound and tightened and locks (prevents) the clip  20  from returning in a direction opposite to the winding and tightening direction in the entered state. 
     Further, the main body of the clip  20  has a spring property, is arranged to shift to the diameter-reduced state (state in which the fuel damper  10  is fixed) by the elastically restoring force thereof, and is held in the diameter-enlarged state by attaching a lock pin RP before the fuel damper  10  is fixed (refer to  FIG. 5 ). Therefore, when the lock pin RP is removed, the main body of the clip  20  is shifted to the diameter-reduced state by the elastically restoring force thereof. Note that the lock pin RP locks the main body of the clip  20  in the diameter-enlarged state in such a manner that it is engaged with a groove on the outside overlapping surface  22  side and with a groove on the inside overlapping surface  23  side, and when the lock pin RP is removed by depressing a handle outward, it can release the main body of the clip  20  from a locked state. 
     Accordingly, the fuel damper  10  is engaged in the cup portion  6  on the fuel pipe  1  side, and the collar portion  8  of the cup portion  6  is joined to the collar portion  13  of the fuel damper  10 . In this state, the outer peripheries of the fuel damper  10  and the cup portion  6  are covered with the main body of the square cylindrical clip  20 , to which the lock pin RP is attached so that the main body is placed in the diameter-enlarged state (the state of  FIGS. 3 ,  6 A and  6 B). 
     The bent surfaces  25  of the slits  24  ride on the end surface of the lower case  12  of the fuel damper  10 , thereby positioning is performed in an axial direction. When the lock pin RP is removed from this state (diameter-enlarged state of  FIG. 6 ), the diameter of the main body of the clip  20  is reduced by the restoring force thereof, and the main body of the clip  20  is placed in the diameter-reduced state of  FIG. 8  through the process of  FIG. 7 , whereby the cup portion  6  and the fuel damper  10  are wound and tightened. 
     The collar portions  8 ,  13  of the cup portion  6  and the fuel damper  10  enter into the slits  24  of the flat portions  21  and regulate the movement of the collar portions  8 ,  13  in the axial direction to thereby fix both the collar portions  8 ,  13 . Further, since the collar portions  8 ,  13  are held at the three positions in the peripheral direction, they can be stably held. 
     Further, in the diameter-reduced state of  FIG. 8 , the claw portion  27  of the inside overlapping surface  23  enters into the receiving hole  26  of the outside overlapping surface  22 . Thus, when the inside overlapping surface  23  tends to move in a diameter-enlarged direction, the movement thereof is prevented by the claw portion  27  which is caught by the edge of the receiving hole  26 . Accordingly, the wound and tightened state is not released. 
     Therefore, the collar portions  8 ,  13  are wound and tightened around the entire peripheries thereof and held by the slits  24  so that they can be securely fixed. Further, since the claw portion  27  enters into the receiving hole  26  in the diameter-reduced state in which the clip  20  is wound and tightened and locks the return of the clip  20 , the clip  20  can be securely prevented from being falling off. 
     Further, the outside overlapping surface  22  is lifted by the claw portion  27  of the inside overlapping surface  23  while the clip  20  is being wound and tightened as shown in  FIG. 7 . Thus, since the outside overlapping surface  23  is lifted once and then fallen, the force in the winding and tightening direction can be dispersed, so that a brake can be applied to a closing force. This prevents, for example, the fuel damper  10  being damaged due to a closing force being abruptly applied. Accordingly, the collar portions  8 ,  13  can be smoothly fixed. 
     Further, since the abutment sides of the slits  24  against which the collar portion  13  of the fuel damper  10  is abutted have the bent surfaces  25  bent inward and the collar portion  13  of the fuel damper  10  is abutted against the slits  24  through the bent surfaces  25 , the following advantages can be obtained. 
     Although a fuel injection valve can be inserted after a clip is inserted thereinto, this method cannot be applied to the fuel damper. Accordingly, when the clip  20  cannot be fixed before it is wound and tightened, workability is deteriorated (it must be positioned so that it can be fixed at a correct position). Thus, the workability can be improved by positioning the clip  20  on the bent surfaces  25 . 
     Further, since the collar portions  8 ,  13  are received on the flat surfaces (bent surfaces  25 ), they can be prevented from being damaged even if a large assembly force is applied. Note that although plating (coating) is applied to the collar portion  13  of the fuel damper  10  and the collar portion  8  of the cup portion  6  which are received by the flat surfaces (bent surfaces  25 ), respectively, the plating of the collar portion  13  of the fuel damper  10  is more liable to be exfoliated because it is subjected to bending processing more often. Thus, there is also an advantage in that exfoliation of the plating can be prevented by receiving the collar portion  13  of the fuel damper  10  on the bent surfaces  25 . 
     Further, the attachment structure will be explained in detail. The bent surfaces  25  are located in the central portions of the slits  24  in the lengthwise direction thereof, and the portion  28 , in which the bent surfaces are not formed, faces the collar portion  13  of the fuel damper  10  at a position retracted from the bent surfaces  25  (refer to  FIG. 2 ). With this arrangement, the portion  28 , in which the bent surfaces are not formed, acts as a preliminary surface and can receive the collar portion  13  of the fuel damper  10  in the event that the bent surfaces  25  are bent by an abnormal pressure. Thus, a more safe structure can be obtained. 
     Further, a groove  29  is formed between the portion in which the bent surfaces  25  are formed and the portion  28  in which the bent surfaces are not formed. The groove  29  extends to a position further retracted from the portion  28  in which the bent surfaces are not formed (refer to  FIG. 2 ). Stress concentration can be prevented by the groove  29 . 
     Further, a flat portion  30  as a stopper is disposed at the root portion of the outside overlapping surface so as to face the projecting end of the inside overlapping surface  23  (refer to  FIGS. 8A and 8B ). With this arrangement, even if the projecting end of the inside overlapping surface  23  overruns when the clip  20  is wound and tightened, the projecting end is abutted against the flat portion  30  as the stopper so that a stopper function can be obtained. Accordingly, damage of the inside overlapping surface  23  due to the overrun can be prevented. 
     Further, a position confirmation cutout  31  is disposed in the outside overlapping surface  22 , and a reference range setting cutout  32  is disposed in the inside overlapping surface  23  (refer to  FIG. 9 ). They are used to perform alignment by confirming that the outside cutout  31  is positioned in the inside cutout  32  in the diameter-reduced state. That is, when the cutout  31  is observed from the outside, if the inside overlapping surface  23  cannot be observed from the cutout  31 , it is determined that assembly is normally performed. Therefore, the inside cutout  32  is set to a size within a normal range (allowable width). With this arrangement, quality of assembly can be simply checked. 
     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.