JP4068255B2 - Fuel delivery pipe - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a fuel delivery pipe for supplying fuel supplied from a fuel pressurizing pump of an electronic fuel injection type automobile engine to each intake passage or each cylinder of the engine via a fuel injector (injection nozzle). In particular, the present invention relates to a structure of a connecting portion between a communication pipe having a fuel passage and a fuel introduction pipe.
[0002]
[Prior art]
Fuel delivery pipes are widely used in electronic fuel injection systems for gasoline engines. After fuel is sent from a communication pipe having a fuel passage to a fuel injector through a plurality of cylindrical sockets, the fuel delivery pipe is moved to the fuel tank side. There are a type having a return path for returning and a type having no return path (returnless). Recently, the type that does not have a return passage has been increasing due to cost reduction. Along with this, fuel delivery pipes and related products have been generated by reflected waves and pulsation pressure caused by the reciprocating movement of the fuel pump (plunger pump) and the spool of the injector. There has been a problem that parts vibrate and generate strange noises.
[0003]
Japanese Patent Laid-Open No. 11-2164 “Fuel Delivery” pays attention to this problem and manufactures the delivery body with a sheet metal press so that the pulsation resonance rotational speed of the fuel piping system is equal to or lower than the idle rotational speed. It is proposed to set the amount to a certain range. However, many types of fuel delivery pipes are made using a steel pipe having a circular or square cross section, and there are many problems in adopting the above method due to engine specifications, strength, and cost.
Japanese Examined Patent Publication No. 3-62904 “Fuel Rail for Internal Combustion Engine” uses a diaphragm to divide the inside of the communication pipe into a socket side and a pipe wall side in order to prevent the noise of the injector wrap, and pulsates due to the flexibility of the diaphragm And the residual reaction of the injector is absorbed. However, the arrangement of the flexible diaphragm in the longitudinal direction of the communication pipe requires a sealing member, which complicates the structure and restricts the overall shape, thus supporting a wide variety of engine specifications. There is a disadvantage that it can not.
[0004]
[Problems to be solved by the invention]
An object of the present invention is to provide a fuel delivery pipe structure capable of suppressing vibration caused by a reflected wave or pulsation pressure of fuel.
Another object of the present invention is to reduce the speaker effect of the fuel delivery pipe and prevent the generation of abnormal noise.
[0005]
[Means for Solving the Problems]
The aforementioned object of the present invention is achieved by adopting a structure that reduces the reflected wave and pulsation pressure of the fuel in the fuel delivery pipe. This structure is realized by several patterns. In the present invention, the object could be achieved by the following five patterns and combinations thereof.
[0006]
(A) A damping pipe in which the inner end of the fuel introduction pipe projects long inward in the axial direction of the communication pipe and has a free end, and the cylindrical part is elastically deformable. (B) A cantilever in which the inner end portion of the fuel introduction pipe projects long inward in the axial direction of the communication pipe and has a free end. A cylindrical portion of the beam is formed, and a through slit is formed around the cylindrical portion along the circumferential direction. This through slit reduces the pulsation pressure of the fuel. (C) Fuel introduction pipe A cylindrical portion of a cantilever beam having a free end projecting inward in the axial direction of the communicating pipe and having a free end is formed, and a through slit along the axial direction is formed around the cylindrical portion. This through slit reduces fuel pulsation pressure The cylindrical portion of the cantilever to form with long projecting and free end inside the inner end of which is in earthenware pots (D) Fuel inlet tube toward the axial direction of the communicating pipe, around the cylindrical portion A through slit that intersects the circumferential direction and the axial direction is formed, and this through slit reduces the pulsation pressure of the fuel. (E) The inner end of the fuel introduction pipe faces in the axial direction of the communication pipe. A cylindrical portion of a cantilever beam that protrudes long inside and has a free end is formed, and a metallic loose portion is attached to the tubular portion, and this loose portion reduces fuel pulsation pressure. [0007]
[Action]
By adopting such a structure, even in a fuel delivery pipe having a communication pipe made of steel pipe, it is possible to prevent the vibration caused by the inherent resonance frequency and damping capacity of the communication pipe and the generation of abnormal noise due to the speaker effect. There was found. The length and thickness of the elastically deformable damping pipe, the width, length, and number of through slits, or the length and thickness of the loose parts should be such that they do not cause resonance, especially when idling the engine. Can be determined by experiment.
[0008]
The present invention is widely applied to a so-called top feed type fuel delivery pipe in which a socket protrudes from one side of a communication pipe and a so-called bottom flow type fuel delivery pipe in which a communication pipe connects the centers of sockets to each other. Is possible. Since it is not necessary to change the overall dimensions and the mounting dimensions of the fuel delivery pipe, compatibility with the conventional fuel delivery pipe can be maintained. Needless to say, the present invention is also applicable to a sheet metal fuel delivery pipe. Other features and advantages of the present invention will become apparent from the following description with reference to the embodiments of the accompanying drawings.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows the entire fuel delivery pipe (top feed type) 6 according to the present invention. A pipe 1 made of a steel pipe having a square cross section extends along the crankshaft direction and is connected to one end of the pipe 1. The fuel introduction pipe 2 is fixed by brazing or welding. Although the return pipe 3 for returning to the fuel tank can be provided at the other end of the communication pipe, the return pipe 3 is not provided in the returnless fuel delivery pipe.
[0010]
If the socket 4 for receiving the tip of the injection nozzle is a four-cylinder engine, four sockets 4 are attached to the bottom surface of the communication pipe 1 at a predetermined angle. Further, two thick and strong brackets 5 for attaching the fuel delivery pipe to the engine body are bridged across the communication pipe 1 in the lateral direction. The fuel flows in the direction of the arrow, and is injected from the socket 4 to each intake passage or each cylinder via a fuel indicator (not shown).
[0011]
FIG. 2 shows a first embodiment of the present invention, in which a fuel introduction pipe 10 is inserted and fixed to one end of the communication pipe 11. The inner end portion 10a of the fuel introduction pipe 10 forms a cylindrical portion that protrudes long inside the communication pipe, and this cylindrical portion is made of a damping pipe 12 that can be elastically deformed. In order to configure the damping pipe 12, the entire fuel introduction pipe 10 can be made of an elastically deformable material. However, only the damping pipe 12 is processed into a thin wall, or a thin pipe is joined. It can also be formed.
[0012]
FIG. 3 shows a second embodiment of the present invention, in which a fuel introduction pipe 20 is inserted and fixed to one end of the communication pipe 11. The inner end portion 20a of the fuel introduction pipe 20 forms a cylindrical portion that protrudes long inside the communication pipe, and a through slit 22 is formed around the cylindrical portion along the circumferential direction. The pulsation pressure of fuel is reduced. The cylindrical portion 20a can also be made of a damping pipe.
[0013]
FIG. 4 shows a third embodiment of the present invention, in which the inner end portion 30a of the fuel introduction pipe 30 forms a cylindrical portion that protrudes long inside the communication pipe, and an axial direction is formed around the cylindrical portion. A through slit 32 is formed along the through hole 32, and the through slit 32 reduces the pulsation pressure of the fuel. The cylindrical portion 30a can be made of a damping pipe.
[0014]
FIG. 5 shows a fourth embodiment of the present invention, in which the inner end portion 40a of the fuel introduction pipe 40 is formed with a cylindrical portion that protrudes long inside the communication pipe, and a circumference is formed around the cylindrical portion. A through slit 42 intersecting the direction and the axial direction is formed, and this through slit 42 reduces the pulsation pressure of the fuel. The cylindrical portion 40a can also be made of a damping pipe.
[0015]
FIG. 6 shows a fifth embodiment of the present invention, in which the inner end portion 50a of the fuel introduction pipe 50 is formed into a cylindrical portion that protrudes long inside the communication pipe, and the metallic portion is formed in the cylindrical portion. A portion 52 is provided, and this loose portion reduces the pulsation pressure of the fuel.
FIG. 7 shows the entire fuel delivery pipe (bottom flow type) 60 according to another embodiment of the present invention. A communication pipe 61 made of a steel pipe having a circular cross section extends along the crankshaft direction and a socket 64 is shown. The fuel introduction pipe 62 is fixed to one end of the communication pipe 61 by brazing or welding. This example represents a returnless fuel delivery pipe and no return pipe is provided. The fuel introduction pipe 62 can have any of the features described with reference to FIGS. That is, the present invention can be applied to both a top feed type and a bottom flow type fuel delivery pipe.
[0017]
【The invention's effect】
As described in detail above, according to the present invention, even in a fuel delivery pipe having a communication pipe made of a steel pipe, vibration caused by the inherent resonance frequency and damping capacity of the communication pipe, and abnormal noise due to the speaker effect Can be prevented, and its technical effect is extremely remarkable.
[Brief description of the drawings]
FIG. 1 is a perspective view showing an entire fuel delivery pipe according to the present invention.
FIG. 2 is a longitudinal sectional view of a fuel introduction pipe portion showing the first embodiment.
FIG. 3 is a longitudinal sectional view of a fuel introduction pipe portion showing another embodiment.
FIG. 4 is a longitudinal sectional view of a fuel introduction pipe portion showing another embodiment.
FIG. 5 is a longitudinal sectional view of a fuel introduction pipe portion showing another embodiment.
FIG. 6 is a longitudinal sectional view of a fuel introduction pipe portion showing another embodiment.
FIG. 7 is a perspective view showing the entire fuel delivery pipe according to another embodiment.
[Explanation of symbols]
1, 11, 61 Communication pipe 2, 10, 20, 30, 40, 50, 62 Fuel introduction pipe 3 Return pipe 4, 64 Socket 6, 60 Fuel delivery pipe 12 Damping pipe 10a, 20a, 30a, 40a, 50a Shaped parts 22, 32, 42 Through slit 52 Jagged part

Claims (3)

A metal communication pipe having a fuel passage extending in a straight line, a fuel introduction pipe fixed to one end of the communication pipe, and a part projecting across the communication pipe and partially communicating with the fuel passage In the fuel delivery pipe, the open end comprises a plurality of sockets for receiving the tip of the fuel injection nozzle,
An inner end portion of the fuel introduction pipe protrudes long in the axial direction of the communication pipe and forms a cylindrical portion of a cantilever having a free end. A fuel delivery pipe made and characterized in that this damping pipe reduces the pulsating pressure of the fuel. A metal communication pipe having a fuel passage extending in a straight line, a fuel introduction pipe fixed to one end of the communication pipe, and a part projecting across the communication pipe and partially communicating with the fuel passage In the fuel delivery pipe, the open end comprises a plurality of sockets for receiving the tip of the fuel injection nozzle,
An inner end portion of the fuel introduction pipe protrudes long in the axial direction of the communication pipe and forms a cylindrical portion of a cantilever having a free end, and a through slit is formed around the cylindrical portion. The through slit has a shape along the circumferential direction, a shape along the axial direction, or a shape that intersects the circumferential direction and the axial direction, and the through slit reduces the pulsation pressure of the fuel. Fuel delivery pipe characterized by A metal communication pipe having a fuel passage extending in a straight line, a fuel introduction pipe fixed to one end of the communication pipe, and a part projecting across the communication pipe and partially communicating with the fuel passage In the fuel delivery pipe, the open end comprises a plurality of sockets for receiving the tip of the fuel injection nozzle,
A cylindrical portion of a cantilever having an inner end portion of the fuel introduction pipe projecting long in the axial direction of the communication pipe and having a free end is formed, and a metal loose portion is attached to the cylindrical portion The fuel delivery pipe is characterized in that this loose portion reduces the pulsation pressure of the fuel.

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