JP3342194B2 - Fuel distribution pipe - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel distribution pipe for distributing fuel pumped from a fuel tank to a fuel injection valve provided in each cylinder of an engine, particularly an automobile engine.

[0002]

2. Description of the Related Art Pipes used for fuel system piping of automobiles are:
Special consideration must be given to safety because high-pressure fuel flows inside.In particular, the fuel distribution pipe that distributes fuel to each fuel injection valve receives engine heat and transmits engine vibration. Therefore, high reliability in strength was required more than in other parts, and it was often made of aluminum die-casting or steel pipe. However, when the fuel distribution pipe is made of metal such as aluminum die-cast or steel pipe as described above, the heat transfer is good and the fuel is easy to receive heat, and the radiation of the operating noise of the fuel injection valve is large, and And there is a problem that the man-hour for assembly is large. Therefore, various proposals have been made to improve these problems, and for example, there is one described in Japanese Patent Application Laid-Open No. 60-108561. In the fuel distribution pipe of the publication, a supply common passage and a return common passage are formed of resin, and when they are formed, electric wiring for connecting between the centralized connector and each injection valve is embedded. According to the device of the above publication, the heat reception of the fuel is reduced, and the radiation of the operating noise of the fuel injection valve is reduced,
In addition, it is possible to greatly reduce the man-hours for processing and assembly.

[0003]

However, in the apparatus disclosed in Japanese Patent Application Laid-Open No. 60-108561, the electric wiring connecting between the centralized connector and each injection valve is formed by a cross section of the pipe wall around the common supply passage. Because the parts are concentrated in a part of the inside, there is unevenness in strength, the parts with weak strength are greatly bent and cracks are generated there, which grow and expand due to vibration, etc. Is concerned about fuel leaks. The present invention has been made in view of the above problems, and has as its object to provide a fuel distribution pipe made of resin in which electric wiring is embedded so that there is no unevenness in strength.

[0004]

According to a first aspect of the present invention, there is provided a resin passage having a common passage extending in a longitudinal direction, and a distribution passage for distributing fuel from the common passage to each fuel injection valve. In the fuel distribution pipe formed by molding, electric wiring to each fuel injection valve is formed along the common passage on both sides of a cross-sectional main axis having a minimum cross-sectional modulus in a cross section perpendicular to the common passage axis. A fuel distribution pipe made of resin is provided.

[0005]

According to the fuel distribution pipe made of resin according to the first aspect, the electric wiring is disposed by embedding molding on both sides of the cross-section main shaft having the minimum cross-section modulus in a cross section perpendicular to the common passage axis, so that the cross-section coefficient is increased. The bending strength is increased by setting the plane passing through the principal axis of the cross section having the minimum as the neutral plane.

[0006]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a side view showing a structure of a first embodiment according to claim 1 of the present invention, which is viewed from a direction perpendicular to a plane passing through a longitudinal axis of a fuel distribution pipe and a central axis of a fuel injection valve. It is the side view seen. The first embodiment is a fuel injection pipe for simultaneous injection for simultaneously injecting fuel to each cylinder of a four-cylinder engine arranged in series. In the drawing, 1 indicates the entire fuel distribution pipe formed integrally,
Reference numeral 2 denotes a fuel supply common passage provided in the fuel distribution pipe 1 and extending in the longitudinal direction. The fuel supplied from a fuel tank (not shown) under pressure is supplied by a common supply passage 2.
Flows into the fuel distribution pipe 1 from the left end of the cylinder, and passes through a cylinder-specific passage 4 provided inside the fuel injection valve mounting portion 3 for each cylinder.
Is supplied to the inside of the fuel injection valve 5 of each cylinder through
A required amount is ejected from a nozzle (not shown) provided at the end of the fuel tank. The surplus fuel is regulated by a regulator 5 provided at the right end and passes through a common passage 6 for returning fuel to a fuel tank. (Not shown).

Reference numeral 7 denotes a centralized connector, which is an external electric wire (FIG.
(Not shown).
Intensively receive electric signals to be transmitted to the injection valves of each cylinder.
In the first embodiment, the fuel is sorted.
Since injection is performed simultaneously for each cylinder, the supplied signal
There is only one type, and it is located inside the centralized connector 7.
Terminals are 8 for each positive and negative pole⁺And 8^-Sum of
There are only two poles. 9⁺And 9^-Is common for fuel supply
The longitudinally extending joints, one on each side of the passage,
The common lead 9⁺And 9^-And focus
Terminal 8 inside connector 7⁺And 8^-Means
Centralized lead wire 10⁺And 10^-Connected by
You. 1 provided inside the fuel injector mounting portion 3
1⁺And 11^-Is the middle terminal,
The common passage side end is connected to the distribution lead wire 12.⁺And 1
2^-By common lead wire 9⁺And 9^-Connected to
And the other end is connected to the lead wire 13 inside the fuel injection valve 5.
⁺And 13^-The electromagnetic coil inside the fuel injection valve 5
(Not shown). Therefore, concentrated
Terminal 8 on the positive side of connector 7⁺The electrical signal delivered to
10 ⁺, 9⁺, 12⁺, 11⁺, 13⁺Via fuel
When an electromagnetic coil (not shown) inside the injection valve 5 is reached,
13 after flowing inside the magnetic coil^-, 11^-, 12^-, 9
^-, 10^-Flows to ground via Please note that
The electric path on the + (plus) side is indicated by a thick solid line,
The electric path on the (minus) side is shown by a thin solid line.

FIG. 2 is a perspective view of the end on the side where the centralized connector 7 is attached. Similar to FIG. 1, the electric path on the + (plus) side is indicated by a thick solid line, and the electric path on the − (minus) side is indicated. The electrical paths are indicated by thin solid lines.

[0009] Figure 3 is a sectional view taken along the III -III surface of FIG. 1, joint leads 9 ⁺ and 9 ^- with showing the cross-sectional shape of itself, an easily understandable manner the position of the cross section be those with joint leads 9 ⁺ and 9 ^- has a rectangular cross section, the rectangular long side which is parallel to the axis 15 of the cross-section of the distributor pipe 1, the supply side of the fuel of the common passage 2 It can be seen that they are arranged on both outer sides. Here, considering the case where the common leads 9 ⁺ and 9 ^- are not arranged, the width h in the direction along the axis 15 is larger than the width b in the direction perpendicular to the axis 15, It is clear that the modulus is the smallest, the most flexible and weakest with respect to the shaft 15. Therefore, in order to increase the section modulus with respect to the shaft 15 to improve the strength of the distribution pipe 1 and to make it hard to bend, as shown in FIG. 3, the common lead wires 9 ⁺ are provided on both outer sides of the common passage 2 for fuel supply. and 9 ^- which is effective to place a.

[0010] Figure 4, Figure 3 co rectangular cross section on both outer sides of the common passage 2 in the same manner as the lead wires 9 ⁺ and 9 ^- in a cross-sectional view of those disposed viewed along III -III surface of FIG. 1 There is
The short side of the rectangular cross section is made parallel to the axis 15 of the cross section, the section modulus with respect to the axis 15 is further increased, the strength of the distribution pipe 1 is further improved, and the pipe 1 is harder to bend.

FIG. 5 is a side view showing the structure of the second embodiment of the present invention, and is a side view seen from a direction perpendicular to a plane passing through the longitudinal axis of the fuel distribution pipe and the central axis of the injection valve. FIG. The second embodiment is a fuel distribution pipe for independent injection in which fuel is independently injected into each cylinder of a four-cylinder engine arranged in series. Therefore, it is necessary to separately transmit an electric signal for control to the fuel injection valve for each cylinder, and the common connector 7 has one common pole 80 ^- and + (plus ) Side, 81 ⁺ , 82 ⁺ , 83 ⁺ , 84 ^+, and a total of five pole terminals are provided. Corresponding to these five pole terminals, a common passage 2 on the fuel supply side and the return side and 5 around 6
Lead wires 90 ⁻ , 91 ⁺ , 92 ⁺ , 93 ⁺ , 94 ⁺
Are arranged, and the five-pole terminals 80 ⁻ , 81+, 8
2 +, 83 +, 84 + and five lead wires ⁹⁰ - 9
1 ⁺ , 92 ⁺ , 93 ⁺ , and 94 ⁺ are five concentrated lead wires 100 ⁻ , 101 ⁺ , 102 ⁺ , 103 ⁺ ,
It is connected by 104 ^+.

Next, the fuel injection valve mounting portion 3 of each cylinder
Internal intermediate terminal 11^-And 11⁺And the five
Lead wire 90^-, 91⁺, 92⁺, 93⁺, 94⁺Within
Are connected. Each cylinder has a negative (-) side
Intermediate terminal 11^-Is the distribution lead wire 110^-Through
Then, the lead wire 90 on the-(minus) side^-Connected to
However, the intermediate terminal 11 on the + (plus) side⁺Is for each cylinder
The lead wire to be connected is different. For example, +
(Plus) side intermediate terminal 11⁺Is the lead for distribution
Line 111 ⁺Through the lead wire 91⁺And + of the second cylinder
(Plus) side intermediate terminal 11⁺Is the lead for distribution
Line 112 ⁺Through the lead wire 92⁺And the third cylinder +
(Plus) side intermediate terminal 11⁺Is the lead for distribution
Line 113 ⁺Through the lead wire 93⁺And + of the 4th cylinder
(Plus) side intermediate terminal 11⁺Is the lead for distribution
Line 114 ⁺Through the lead wire 94⁺Connected to

In the above configuration, the important thing is that
5 lead wires 90 ^-, 91 ^+, 92 ^+, 93 ^+, 94
⁺ Is the same length in the longitudinal direction. 5
This leads 90 ^-, 91 ^+, 92 ^+, 93 ^+, 94 ⁺
Are made to have the same length in the longitudinal direction, the configuration in the cross section is the same at any position in the longitudinal direction, and the strength in the longitudinal direction is uniform. FIG. 6 shows one cross section obtained in such a manner, and is viewed along the VI-VI plane in FIG.

FIG. 7 shows the structure of a fuel distribution pipe for independent injection according to the prior art.
Lead wire 13 on the-(minus) side of the fuel injection valve of each cylinder
^- for connection to - (minus) side of the intermediate terminal 11 ^- the dispensing of lead + lead extending in the longitudinal direction for delivering the (positive) terminal, i.e. 5,
6, the leads 191 ⁺ , 192 ⁺ , 193 ⁺ , and 19 ⁺ corresponding to the leads 91 ⁺ , 92 ⁺ , 93 ⁺ , and 94 ^+.
4 ⁺ it is terminated at the fuel injection valve for each cylinder, respectively. Therefore, the configuration in the cross section differs depending on the position in the longitudinal direction. For example, VIII-VIII and IX-I in FIG.
FIG. 8A is a cross-sectional view taken along each plane of X and XX.
Although shown in (B) and (C), they are not uniform as shown, indicating that the strength varies depending on the position in the longitudinal direction.

FIG. 9 is a sectional view showing the structure of a third embodiment of the present invention. Each lead wire is distributed around the common passage 2 on the fuel supply side and the common passage 6 on the return side. Rather, they are arranged in a concentrated manner outside the common passage 2 on the supply side. This is based on the assumption that the flame contact direction in which the flame strikes the fuel distribution pipe 1 when a fire occurs is the direction indicated by the arrow F. If the flame contact direction is different, the flame contact direction is changed. The lead wires are intensively arranged so as to face. Although not particularly shown in the side view, the length of each lead wire in the longitudinal direction is the same.

According to the third embodiment,
In addition to the effect of strength reinforcement, when a fire occurs, the temperature of the flame contact surface decreases due to the heat conduction of the lead wire made of metal material, and even if the resin is melted from the flame contact surface side The presence of metal lead wires reduces the area of flame contact with the resin, so if a fire should occur, increase the time it takes for the flame to reach the fuel itself. Is possible, and the burnout resistance is improved.

FIG. 10 is a cross-sectional view showing the structure of a fourth embodiment of the present invention. Each lead wire extends in the flame contact direction similarly to the third embodiment shown in FIG. As shown, each lead wire is temporarily embedded in the holding member 20, and the holding member 20 is embedded in the fuel distribution pipe 1. This is due to the following reasons: when the lead wire is embedded in the resin fuel distribution pipe 1, the lead wire is long in the longitudinal direction. This is because, even if fixed, the central portion may be deformed by the resin molding pressure and short-circuiting between the lead wires or interference with the fuel passage may cause a security defect.

Accordingly, first, a holding member 20 made of an electrically insulating material is attached to each lead wire to make a plurality of lead wires into a sub-assembly. 1 is embedded at the time of resin molding. By doing so, the lead wire is not deformed by the molding pressure when the fuel distribution pipe is molded with the resin, and the above-mentioned problem is solved. In addition,
As a method of attaching the holding member 20 made of an electrically insulating material to each lead wire, a method of solidifying the periphery with a resin without applying a high pressure can be considered, and the resin is used as a resin for molding the main body of the fuel distribution pipe 1. If the rigidity is higher and the fire resistance is higher, the strength and burnout resistance are further improved as compared with the third embodiment.

[0019]

According to the first aspect of the present invention, there is provided a common passage extending in the longitudinal direction, and a distribution passage for distributing fuel from the common passage to each fuel injection valve, and is formed by resin molding. In the fuel distribution pipe, the electric wiring to each fuel injection valve is embedded along the common passage on both sides of the cross-sectional main axis where the cross-sectional coefficient is minimum in a cross section perpendicular to the common passage axis, so that the cross-sectional coefficient is minimum. The bending strength with the plane passing through the main axis of the cross section as a neutral plane is increased, and the occurrence of cracks and, consequently, the occurrence of fuel leakage are prevented.

[Brief description of the drawings]

FIG. 1 is a side view of a first embodiment of the present invention.

FIG. 2 is a perspective view of the first embodiment of the present invention.

FIG. 3 is a sectional view taken along the line III-III in FIG. 1;

FIG. 4 shows a modification of the first embodiment of the present invention in FIG.
It is sectional drawing seen along the III plane.

FIG. 5 is a side view of a second embodiment of the present invention.

6 is a sectional view taken along the plane VI-VI in FIG. 5;

FIG. 7 is a side view of a conventional fuel distribution pipe for independent injection.

8A is a sectional view taken along the plane VIII-VIII in FIG. (B) It is sectional drawing seen along the IX-IX plane of FIG. (C) It is sectional drawing seen along the XX plane of FIG.

FIG. 9 is a sectional view of a third embodiment of the present invention.

FIG. 10 is a sectional view of a fourth embodiment of the present invention.

[Explanation of symbols]

1 ... (for fuel supply) fuel distribution pipe 2 ... common passage 3 ... fuel injection valve mounting portion 5 ... fuel injection valves 6 ... (for fuel return) common path 7 ... concentrate connector 8 ⁺ 8 - ^... terminal 9 ⁺ , 9 ^- ... common lead wire 11 ^+, 11 ^- ... intermediate terminal 20 ... holding member (fourth embodiment) 90 ^-, 91 ^+, 92 ^+, 93 ^+, 94 ⁺ ... common lead

Continuation of front page (72) Inventor Takeomi Yamamoto 10 Hamadashita, Nakahata-cho, Nishio-shi, Aichi, Japan Otics Co., Ltd. (56) References JP-A-60-108561 (JP, A) U) (58) Fields surveyed (Int. Cl. ⁷ , DB name) F02M 55/02 340 F02M 51/06

Claims (1)

(57) [Claims] 1. A fuel distribution pipe comprising: a common passage extending in a longitudinal direction; and a distribution passage for distributing fuel from the common passage to each fuel injection valve. A resin distribution pipe made of resin, wherein electric wiring to the fuel passage is embedded along the common passage on both sides of a cross-sectional main axis having a minimum sectional modulus in a cross section perpendicular to the common passage axis.