JP2007032374A - Fuel delivery pipe - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To absorb pulsation sounds generated on a low frequency side in the communicating tube of a fuel delivery pipe, to reduce radiative noises generated on a high frequency side, and reduce both the vibration and noises of vehicle component members. <P>SOLUTION: In this fuel delivery pipe provided with the communicating tube 1 having a fuel passage 26 in its inside and provided with an absorbing surface on its wall surface, a fuel introducing pipe 2 connected to the communicating tube 1, and a socket 4 with one end connected to the communicating tube 1 so as to be communicated with the fuel passage 26 and the other end connected to the rear end of an injection nozzle, a recessed part and/or projecting part is formed in a longitudinal direction on the absorbing surface of the communicating tube 1, and cross-sectional shapes in a perpendicular direction to the tube axial of the communicating tube 1 are made different in two or more portions of the communicating tube 1. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a fuel for supplying fuel fed from a fuel pressurizing pump of an electronic fuel injection type automobile engine via a fuel injector (injection nozzle) that directly injects the fuel into each intake passage or cylinder of the engine. It relates to a delivery pipe, and aims to reduce pressure pulsation and radiation noise caused by fuel injection. Further, the present invention relates to a cross-sectional structure of a fuel delivery pipe having a fuel passage and an external structure of the fuel delivery pipe or a mechanism for reducing pressure pulsation and radiation noise of the fuel delivery pipe.

  2. Description of the Related Art Conventionally, there is known a fuel delivery pipe that is provided with a plurality of injection nozzles and supplies fuel such as gasoline to a plurality of cylinders of an engine. This fuel delivery pipe injects fuel introduced from a fuel tank sequentially into a plurality of intake pipes or cylinders of an engine from a plurality of injection nozzles, mixes this fuel with air, and burns this mixture. The engine output is generated.

  This fuel delivery pipe is for injecting the fuel supplied from the fuel tank through the underfloor pipe to the intake pipe or cylinder of the engine from the injection nozzle as described above. The supplied fuel is the fuel delivery pipe. There is a return type fuel delivery pipe having a circuit for returning the excess fuel to the fuel tank by a pressure regulator when it is supplied excessively. Unlike the return type fuel delivery pipe, there is a returnless type fuel delivery pipe that does not have a circuit for returning the supplied fuel to the fuel tank.

  The system that returns the fuel supplied to the fuel delivery pipe back to the fuel tank has the advantage that the amount of fuel in the fuel delivery pipe can always be kept constant, so that pressure pulsation associated with fuel injection is less likely to occur. have. However, the fuel supplied to the fuel delivery pipe located close to the high-temperature engine cylinder becomes hot, and the temperature of gasoline in the fuel tank rises by returning this high-temperature excess fuel to the fuel tank. To do. This temperature rise is undesirable because gasoline vaporizes and adversely affects the environment, so a returnless fuel delivery pipe that does not return this excess fuel to the fuel tank has been proposed.

  This returnless type fuel delivery pipe has a large pressure fluctuation of the fuel in the fuel delivery pipe because there is no piping for returning excess fuel to the fuel tank when injection from the injection nozzle to the intake pipe or cylinder is performed. As a result, a large pressure wave is generated, and the occurrence of pressure pulsation is larger than that of the return type fuel delivery pipe.

  In the prior art, when the inside of the fuel delivery pipe is depressurized by the fuel injection from the engine intake pipe or the injection nozzle to the cylinder, the pressure wave generated by the sudden depressurization and the stop of the fuel injection is generated. The pressure pulsation is generated inside the fuel delivery pipe. This pressure pulsation is propagated from the fuel delivery pipe and the connecting pipe connected to the fuel delivery pipe to the fuel tank side, then reversed and returned from the pressure regulating valve in the fuel tank, and then the fuel delivery pipe is connected via the connecting pipe. Is propagated. The fuel delivery pipe is provided with a plurality of injection nozzles, and the plurality of injection nozzles sequentially inject fuel to generate pressure pulsation.

As a result, the underfloor piping is propagated as noise into the vehicle through a clip that holds the underfloor pipe under the floor, and this noise makes the driver and the passenger uncomfortable.
Conventionally, as a method of suppressing such harmful effects caused by pressure pulsation, a pulsation damper containing a rubber diaphragm is placed in a returnless type fuel delivery pipe, and the generated pressure pulsation energy is absorbed by this pulsation damper. If the underfloor pipe located under the floor from the fuel delivery pipe to the fuel tank side is fixed to the underfloor via a vibration absorbing clip, it will occur in the fuel delivery pipe or underfloor pipe to the tank. Absorbing vibration is done. These methods are relatively effective and have the effect of suppressing the adverse effects caused by the occurrence of pressure pulsation.

  However, pulsation dampers and vibration-absorbing clips are expensive, increasing the number of parts and increasing costs, and creating new problems in securing installation space. Therefore, as in the inventions described in Patent Documents 1 and 2, pressure pulsation can be absorbed in the fuel delivery pipe for the purpose of reducing pressure pulsation without using these pulsation dampers and vibration absorbing clips. Those having a pulsation absorbing function have been proposed.

That is, in the invention described in Patent Document 1, a flexible absorber surface is provided on the wall surface of the communication pipe, and a cross-sectional shape perpendicular to the pipe axis direction is a bellows shape. In addition, the invention described in Patent Document 2 includes an absorber surface on the wall surface of the communication tube, and a cross-sectional shape perpendicular to the tube axis direction is formed in a T shape, a dumbbell shape, or an inverted eye mask shape. . Moreover, the cross-sectional shape perpendicular to the tube axis direction of the communication pipes of Patent Documents 1 and 2 is the same from one end to the other end of the communication pipe. And it aims at absorbing the impact and pulsation by the distortion of the absorber surface of the communication pipe formed as described above, and reducing the generation of abnormal noise caused by the reflected wave by the injector and the vibration caused by the pulsation pressure. .
JP 2000-320423 A JP 2000-329031 A

  However, in the inventions described in Patent Documents 1 and 2, it is possible to absorb the pulsating sound generated on the low frequency side as described above, but it is difficult to reduce the radiation noise generated on the high frequency side. There was still a problem of noise, such as the generation of ticks.

  Accordingly, the present invention is intended to solve the above-described problems, and absorbs pulsation sound generated on the low frequency side in the communication pipe and enables reduction of radiated noise generated on the high frequency side so that vibrations of vehicle constituent members can be reduced. Both are intended to reduce noise and noise.

  In order to solve the above-mentioned problems, the present invention includes a communication pipe having a fuel passage inside and a wall surface having an absorber surface, a fuel introduction pipe connected to the communication pipe, and one end connected to the communication pipe. A fuel delivery pipe having a socket communicating with the fuel passage and having the other end connected to the rear end of the injection nozzle, wherein a recess and / or a protrusion is formed in the longitudinal direction on the absorber surface of the communication pipe, and the communication pipe The cross-sectional shape in the direction perpendicular to the tube axis is different at a plurality of locations of the communication tube.

  Further, the communication pipe may be obtained by dividing the wall surface in the vertical direction.

  Further, the communication pipe may be a pipe type having an integral structure.

  Further, the socket may be formed in a cylindrical straight shape from one end to the other end.

  The present invention is configured as described above, and is formed with a recess and / or a protrusion in the length direction of the flexible absorber surface formed in the communication pipe, and a sectional shape in a direction perpendicular to the tube axis of the communication pipe. Is made different at a plurality of locations of the communication pipe, so that the pulsation sound generated on the low frequency side in the communication pipe can be absorbed and the radiation noise generated on the high frequency side can be reduced. Therefore, by suppressing the transmission and propagation of the seating sound of the spool that reciprocates when the fuel injector is opened and closed, the noise is reduced without impairing the fuel pulsation absorption performance, and both the vibration and noise of the vehicle components are reduced. It can be reduced.

  A first embodiment of the present invention will be described with reference to FIGS. 1 to 13. Reference numeral (1) denotes a communication pipe, which has a substantially flat shape having Rs at corners. As shown in FIG. 3, the communication pipe (1) is divided into two parts in the vertical direction. The connection side of the fuel introduction pipe (2) is the upper body (3), and the connection side of the socket (4) is the lower body (5). Assembling these upper body (3) and lower body (5), the upper wall (6), bottom wall (7), both side walls (8) and both end walls (9) of the communication pipe (1) Forming a wall surface. Further, the upper wall (6) and the bottom wall (7) of the communication pipe (1) are formed as an absorber surface that can be deformed and deformed by receiving pressure generated with fuel injection from the injection nozzle. In the present embodiment, the communication pipe (1) is formed by being divided in the vertical direction as described above. However, in another different embodiment, it may be formed in a single-piece pipe type.

  The fuel delivery pipe of the first embodiment will be described in detail. The upper body (3) forming the communication pipe (1) constitutes the upper wall (6) of the communication pipe (1) as shown in FIG. The upper wall (6), a pair of upper side walls (10) and a pair of upper end walls (11) connected to each other with an R portion at the corner, and the overall shape is a flat, substantially rectangular parallelepiped. In addition, two upper side wall recesses (12) are formed on one upper side wall (10) of the upper body (3) so as to be recessed in an arc shape inward in the width direction of the upper body (3). Further, a substantially trapezoidal upper side wall bulging portion (13) protruding outward is formed on the other upper side wall (10).

  Further, the upper wall (6) of the upper body (3) is provided with an upper groove (14) having a U-shaped cross section that is continuous in the axial direction from one end to the other end. As shown in FIG. 2, the width of the upper concave groove (14) is wide at the center and narrow at both ends, and the interval between the wide and narrow portions is tapered. I am letting. Further, an insertion port (15) for inserting the tip of the fuel introduction pipe (2) is provided at the center in the length direction of the upper concave groove (14) of the upper wall (6).

  Further, as shown in FIG. 3, the lower body (5) includes a bottom wall (7) constituting the bottom wall (7) of the communication pipe (1) and a pair of lower side walls connected to each other with an R portion at the corner. (16) and a pair of lower end walls (17), and circular communication ports (24) are opened in the bottom wall (7) at four desired positions in the axial direction. Further, a lower side wall recess (18) having a shape corresponding to the upper side wall recess (12) is formed in the lower side wall (16) at a position corresponding to the position where the upper side wall recess (12) of the upper body (3) is formed. In addition, the other lower side wall (16) has a shape corresponding to the upper side wall bulging part (13) at a position corresponding to the position where the upper side wall bulging part (13) of the upper body (3) is formed. A side wall bulging portion (20) is formed.

  Further, on one side of the bottom wall (7) of the lower body (5), a lower one-side protruding portion (21) having a constant width extending from one end to the other end in the axial direction is projected, and this bottom wall ( 7) On the other side opposite to the one side, a lower rectangular side projection (22) having a substantially rectangular shape elongated in the axial direction is provided in the axially central portion. Further, adjacent to the lower one-side protrusion (21) formed on the bottom wall (7) as described above, a rectangular downward concave groove (23) elongated in the axial direction is provided on both side walls (9) side. Each one is recessed. The lower one-side protrusion (21), the lower other-side protrusion (22), and the lower concave groove (23) are disposed at positions that do not contact the communication port (24) formed in the bottom wall (7). Has been.

  The pair of lower side walls (16) and the lower end wall (17) of the lower body (5) formed as described above are connected to the pair of upper side walls (10) and the upper end wall (11) of the upper body (3). The upper body and the lower body are assembled by inserting each inside, and in this state, the upper body (3) and the lower body (5) are continuously brazed in the circumferential direction, and the upper body ( 3) and the lower body (5) are fixed to each other to form a communication pipe (1). The pair of upper side walls (10) of the upper body (3) and the pair of lower side walls (16) of the lower body (5) constitute a pair of side walls (8) of the communication pipe (1). The pair of upper end walls (11) of the body (3) and the pair of lower end walls (17) of the lower body (5) constitute a pair of end walls (9) of the communication pipe (1).

  Further, as shown in FIG. 3, one side wall (8) of the communication pipe (1) is formed by an upper side wall recess (12) of the upper body (3) and a lower side wall recess (18) of the lower body (5). The side wall recess (25) is formed, and the other side wall (8) has an upper side wall bulging portion (13) of the upper body (3) and a lower side wall bulging portion (20) of the lower body (5). Thus, the side wall bulging portion (28) is formed. A space formed by the inner surface of the upper body (3) and the inner surface of the lower body (5) of the communication pipe (1) is used as a fuel passage (26) through which fuel passes.

 Then, by forming the communication pipe (1) as described above, the cross-sectional shape perpendicular to the tube axis direction of the communication pipe (1) has a plurality of locations in the communication pipe (1) as shown in FIGS. Each has a different shape. The upper groove (14) formed in the upper body (3) and the lower groove (23) formed in the lower body (5) constitute the upper groove (14) and the lower groove (23). A pair of upper groove side walls (30) and lower groove side walls (31) are connected to the upper groove opening (35) and the lower groove opening (36) from the upper groove bottom surface (33) and the lower groove bottom surface (34). It is inclined in a taper shape that is widened toward).

  In the communication pipe (1) formed as described above, the fuel introduction pipe (2) whose end portion is bent in an L shape is inserted into the insertion port (15) formed in the upper wall (6) of the communication pipe (1). By inserting the tip and fixing the contact portion between the communication pipe (1) and the insertion port (15) by brazing or the like, the fuel introduction pipe (2) is connected to the communication pipe (1) as shown in FIG. Connected. The fuel introduction pipe (2) is disposed above the upper concave groove (14) and along the upper concave groove (14).

  By arranging the fuel introduction pipe (2) above the upper concave groove (14) in this way, the fuel introduction pipe (2) communicates with the upper wall (6) of the communication pipe (1) in a state where it is difficult to contact. Since it can arrange | position close to a pipe | tube (1), it becomes possible to improve the layout property of a fuel delivery pipe. Moreover, as shown in FIG. 1, the bracket (27) is each assembled | attached to the bottom wall (7) of a communicating pipe (1) in the formation position of a side wall recessed part (25).

  Further, the communication port (24) provided in the bottom wall (7) shown in FIG. 3 is formed in a cylindrical straight shape with the same inner and outer diameters from one end to the other as shown in FIG. Connected socket (4). Therefore, the elastic wave emitted from the injection nozzle (not shown) hardly collides / reflects on the wall surface around the fuel inlet (32) of the socket (4), and does not generate a standing wave. As it passes through the fuel inlet (32), it propagates to the wall surface of the absorber. Therefore, since the pulsation pressure is absorbed by the absorber wall surface, vibration and noise can be reduced, and noise in a high frequency range radiated from an injection nozzle (not shown) can be reduced.

  FIG. 13 shows the result of frequency analysis for measuring the sound pressure generated in the communication pipe (1) in the fuel delivery pipe formed as described above. In this frequency analysis, a microphone was installed at a position 500 mm above the upper wall in the center in the length direction and width direction of the upper wall (6) of the communication pipe (1). Further, as shown in FIG. 14 and FIG. 15, a communication pipe (50) that has been generally used conventionally, in which the cross-sectional shape is rectangular and goggles, and the same shape from one end to the other end, It measured similarly as the comparative example 1 and the comparative example 2 of a present Example.

  As a result, as shown in FIG. 13, in this embodiment, the peak positions indicated by the broken lines in FIG. 13 are higher than those in the other comparative examples 1 and 2 in the middle and high frequencies of the line graph in FIG. Overall it was low. That is, in this example, the peak position was lower in the middle region than in Comparative Example 1, and the peak position was lower in the higher region than in Comparative Example 2.

  From the above results, as described above, in the communication pipe (1) of the present embodiment, the pulsation pressure generated on the low frequency side and the high frequency side are generated as compared with the communication pipe (50) of Comparative Examples 1 and 2. It became clear that both radiated sound was reduced. Therefore, as described above, the upper groove (14), the lower groove (23), and the lower one-side protrusion (21) in the length direction of the upper wall (6) and the bottom wall (7) of the communication pipe (1). And forming the other side protrusion (22) and forming the communication pipe (1) so that the cross-sectional shape in the direction perpendicular to the tube axis of the communication pipe (1) is different at a plurality of locations of the communication pipe (1). This suppresses the transmission and propagation of the seating sound of the spool that reciprocates when the fuel injector is opened and closed, and does not show a markedly high peak in each frequency component as described above, thereby impairing the fuel pulsation absorption performance. Therefore, it is possible to reduce the noise and reduce the vibration and noise of the vehicle constituent members.

The perspective view seen from the bottom wall side of the fuel delivery pipe which shows the Example of this invention. The perspective view seen from the upper body side of the communicating pipe of Example 1. FIG. The perspective view seen from the lower body side of the communicating pipe of Example 1. FIG. The top view seen from the upper body side of the fuel delivery pipe of Example 1. FIG. AA line sectional view of Drawing 3. BB sectional drawing of FIG. CC sectional view taken on the line of FIG. The DD sectional view taken on the line of FIG. EE sectional view taken on the line of FIG. FIG. 4 is a sectional view taken along line FF in FIG. 3. The GG sectional view taken on the line of FIG. HH sectional view taken on the line of FIG. Line graph showing sound pressure in frequency analysis. Sectional drawing of the communicating pipe of the comparative example 1 which shows a prior art example. Sectional drawing of the communicating pipe of the comparative example 2 which shows a prior art example.

Explanation of symbols

1 communication pipe 2 fuel introduction pipe 4 socket 26 fuel passage

Claims (4)

  A communication pipe having a fuel passage inside and having an absorbent surface on the wall surface, a fuel introduction pipe connected to the communication pipe, one end connected to the communication pipe and communicating with the fuel passage, and the other end connected to the injection nozzle In a fuel delivery pipe having a socket connected to the rear end, a recess and / or a protrusion is formed in the longitudinal direction on the absorber surface of the communication pipe, and the cross-sectional shape in the direction perpendicular to the tube axis of the communication pipe is communicated. A fuel delivery pipe characterized in that it is different in a plurality of places of the pipe.   The fuel delivery pipe according to claim 1, wherein the communication pipe has a wall surface divided in the vertical direction.   2. The fuel delivery pipe according to claim 1, wherein the communication pipe is an integral structure pipe type. The fuel delivery pipe according to claim 1, wherein the socket is formed in a cylindrical straight shape from one end to the other end.

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