CA1213803A

CA1213803A - Fuel injection system

Info

Publication number: CA1213803A
Application number: CA000452874A
Authority: CA
Inventors: Katsuhiko Kimura; Toshio Shioya
Original assignee: Honda Motor Co Ltd
Current assignee: Honda Motor Co Ltd
Priority date: 1983-04-27
Filing date: 1984-04-26
Publication date: 1986-11-12
Also published as: GB2138887A; GB8410838D0; DE3415780A1; GB2138887B

Abstract

ABSTRACT
A fuel injection system including a plurality of fuel injection valves connected to a fuel supply unit by means of a holding bracket with the combined fuel injection valve and fuel supply unit assembly being mounted on the intake manifold of an engine such that the nozzle end of the fuel injection valves are in communication with the manifold intake passages and cylinder intake ports. The fuel injection system further including a single elastic sealing ring for sealing the end of the fuel injection valves within the fuel supply unit, said sealing ring having a plurality of annular sealing projec-tions.

Description

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FUEL INJECTION SYSTEM

Field of Invention The present invention relates to a fuel injection system including a plurality of fuel injection valves the nozzle ends of which project into intake passages associated with the cylinders o a multi-cylinder engine and the intake ends of which are connected to a common fuel supply unit and fuel passage.

Background of Invention In conventional fuel injections systems of this type, each individual fuel injection valve is supported between a fuel supply unit and an intake manifold. The fuel injection valves are distinct units separate from both the fuel supply unit and intake manifolds, thus making the assembly or disassembly of the fuel injection system a troublesome opera-tion. Further, due to the fuel injection valves being distinct units when the fuel supply unit is disconnected from the intake manifold the fuel injection valves do not remain in a completely mounted state with respect to the fuel supply unit therefore making it difficult to conduct a pressure test of the fuel injection valves as mounted in the fuel supply unit. This has led to great inconvenience on the part of the automobile mechanic desiring to pressure test the system.

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F~lrther, the present invention relates to a fuel injection system in which apertures are formed in a side portion of a fuel supply unit having a central fuel passage so as to intersect said fuel passage. The fuel injection valves are connected to the fuel supply unit by means of a holding bracXet affixed to said fuel supply unit such that when the fuel injection valve is held by the holding bracket the intake end of the fuel injection valve fits within the aperture formed in the side portion of the fuel supply unit.
In prior mounting structures of this sort, nipple portions were provided on the side of the fuel supply unit and the intake ends of the fuel injection valves were inserted into the nipple portions after attaching an O-rinq and a seal ring to each of the intake ends. In such prior mounting struc-tures, however, it was necessary .hat the fuel injection valve and the nipple portion be exactly aligned with each other when inserting the former into the latter in order to prevent the 0-ring or the seal ring from being twisted or broken. Thus, prior mounting operations required considerable skill and were quite troublesome. Further, with the prior systems the mere insertion of the intake end of the fuel injection valve into the nipple portion did not prevent the fuel injection valve from becoming separated from the nipple portion, thereby ren~
dering it necessary to secure the fuel injection valve by loading or compressing the O-ring and the seal ring by means of a spring or other biasing means. Further, in such prior mounting structures it was necessary to provide at least two members, one beinq a seal ring for restricting lateral movement of the fuel injection valve and the other being an O-ring for preventing fuel leakage.

7/20g The present invention solves the above-mentioned technical problems inherent in the prior art.
According to this invention there is provided a fuel injection system for a multi-cylinder engine having an intake manifold with a fuel injection valve for each cylinder, com-prising; a fuel supply unit having insertion apertures for receiving each injection valve, a holding bracket for supporting each injection valve, an elastic sealing ring positioned in each said insertion aperture for sealing betwe~ said fuel injection valve and said fuel supply unit, said fue~ injection valves supported in place with respect to the fuel supply unit by means of the holding bracket, a vibration absorption member supporting each fuel injection valve on said holding bracket, means connecting said holdlng bracket to said fuel supply unit for mounting that combination with the injection valves to the engine as a unit.
Also according to the invention there is provided a fuel injection system for a multi-cylinder engine having an intake manifold with a fuel injection valve for each cylinder, comprising; a fuel supply unit having aper-tures for receiving each injection valve, a holding bracket having means for supporting each injection valve, and means for releasably con-necting said mounting bracket to said fuel supply unit with the injection valves in position for mounting to the engine as a unit.
Brief Description of Drawing _ 1. Figure 1 is a partial cross-sectional side view of the present invention as mounted on an automobile engine.

2. Figure 2 is an elevated partial cross-sectional view of the invention as mounted on a four-cylinder engine.

3. Figure 3 is a side view of the fuel supply unit.

4. Figure 4 is a partial cross-sectional side view of a fuel injection valve mounted within the fuel supply unit.

5. Figure 5 is a partial bottom view of -the holding bracket mounted on the fuel supply unit.

6. Figure 6 is a side cross-sectional view of -the holding bracket.

7. Figure 7 is a cross-sectional side view of the present invention.

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8. Figure 8 is a cross-sectional side view of on Eorm of an elastic sealing ring.

9. Figure 9 is a side view of the intake end of the fuel injection valve.

10. Figure 10 is a top view of the intake end of the fuel injection valve.

Detailed Description of the Invention The overall arrangement of the present invention is shown in Figures 1 and 2. Figure 1 shows a single fuel injec-tion valve V1 connected to a fuel supply unit 5 with the combined fuel injection valve and fuel supply unit mounted on the intake manifold Mi such that the valve nozzle 36 is in communication with the intake passage 3 of the manifold Mi and the engine intake port 2. Figure 2 shows the invention as utilized on a four-cylinder engine. Four fuel injection valves V1 ~ V4 are connected to the fuel supply unit 5. The entire assembly is then mounted on the intake manifolds of the engine E as shown in Figure 1.
The invention will now be described in detail as shown in Figures 4-9. A solenoid-operated fuel injection valve V3 is shown in Figures 4 and 7. The valve V3 has a central body section Va and an upper intake section and a lower nozzle section. The upper intake section of the valve consists of a short cylindrical section 19, a circular flange 20 and a larger diameter cylindrical section 39 as shown in Figure 7.
The upper intake section of the fuel injection valve V3 is mounted within the fuel supply unit 5 as shown in Figures 4 and 7. The upper end of the valve is inserted within an insertion ~2~ 3 aperture 17 which is connected to the first fuel passage 8 by means of a communication passage 18.
The fuel supply unit 5 is shown in detail in Figure 2. The unit is comprised of an elongated body 6 having a first Euel passage 8 and a second fuel passage 9. The first fuel passage 8 runs the length of the body 6, while the second fuel passage 9 terminates at an intermediate point on the body.
The two passages are connected together by means of a fuel body cap 7 which is mounted on one end of the body 6 as shown in Figures 2 and 3. The cap 7 has hollow center section which allows for fuel to flow from passage 8 to passage 9. A
coupling joint 1Q is affixed to the opposite end of the body 6 and connects the fuel supply unit 5 to a fuel source. Although not shown, a fuel pressure regulating valve is connected to the second fuel passage 9 at the intermediate point through an aperture 37 whereby the fuel pressure in passageways 8 and 9 remains constant. As shown in Figure 2 a plurality of fuel injection valves V1 - V4, corresponding in number to the number of cylinders of the engine, are connected to the fuel supply unit 5 at the mounting portions M1 - M4 and are in comrnunication with the first fuel passage 8 by means of communication passages 18. Each injection valve has a wiring connector portion 15 for electrically oper~ting the valves.
The fuel injection valve is held in place with respect to the fuel supply unit by means of a holding bracket 24 which is connected to the fuel supply unit 5. The holding bracket 24 has a support arm 38 which extends downward from the fuel supply unit 5 and a cylindrical holding member H3 which extends outward from the bottom of the support arm as shown in Yigures 4 and 7. The fuel injection valve fits within the holding member H3 as shown. A circular radial flange 26 8~9~

extends inward from the member H3 and abuts the body of the fuel injection valve V3. A vibration absorbing member 25 is fitted between the fuel injection valve V3 and the holding member H3 as shown in Figure 7 to lessen the amount oE vibra-tion transmitted from the engine E to the valve V3.
As shown in Figures 2 and 5 the holding bracket 24 is of an elongated configuration and is of approximately the same length as the fuel supply unit 5 and has a plurality of holding members H1 - H4 corresponding in number to the insertion apertures 17. As shown in Figures 2 and 5 the holding bracket 24 is mounted to the fuel supply unit 5 by means of connecting portions 27 extending from the bracket 24 which are connected to the fuel supply unit by means of mounting bolts 28.
Mounting portions M1 - M4 are provided on the fuel supply unit for receiving the upper intake section of the fuel injection valve. Sealing means are provided in each mounting portion for sealably connecting the injection valve to the supply unit and while an 0-ring and sleeve may be employed, a specially designed seal ring 23 is preferred to prevent the leakage of fuel. This is shown in Figures 7-9.
The elastic seal ring 23 is comprised of a cylindrical body portion 22, an upper inward flange portion 21 which projects radially inwards of one end of the body portion 22 and a lower flange portion 30 projecting radially inwards at the other end of the body portion 22. The upper inward flange 21 has a first annular sealing projection 31 projecting from its upper face, a second annular sealing projectîon 32 projecting from the outer peripheral face of the body 22, a third annular sea~ling projec-tion 33 projecting from the lower outer corner portion of the upper flange 21 and a fourth annular sealing projection 34 projecting from the inner corner of the upper flange 21.

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The intake section oE the fuel injection valve is shown in Figure 9 set within the insertion aperture 17 in the fuel supply unit 5 without the elastic sealing ring 23 in place.
The operation of the sealing ring 23 will now be discussed in conjunction with Figures 8 and 9. The natural axial thickness D1 of the upper inward flange 21 is slightly larger than the length L1 of the cylindrical section 19 and the radial width D2 of the flange 21 is slightly smaller than the distance L2 between the cylindrical section 19 and the in surface of the aperture 17. The relationship between D1, D2, L1 and L2 is such that the volume of the inward flange 21 occupies 82~ to 114% of the volume of ~he space defined by the upper face 17a of the aperture 17/ the side face of the aperture 17, the upper face of circular flange 20 and the outer face of cylinder section 19.
In the preferred embodiment the volume of inward flange 21 is approximately 97% of the volume of the area just described.
Figure 7 shows the sealing ring 23 in place about the intake section of the fuel injection valve mounted within the fuel supply unit 5. When inserting the fuel injection valve within the fuel supply unit, the elastic sealing ring 23 is first placed atop the valve such that the upper flange 21 of the sealing ring 23 rests atop the upper surface of the circular flange 20 and the lower flange 30 of the sealing ring 23 extends inward beneath the circular flange 20 with the upper surface of flang~ 30 being in contact with the lower surface of circular flange 20. The fuel injection valve within the elastic sealing ring 23 now in place is then inserted within the insertion aperture 17 until the upper face 35 of the cylindrical section 19 abuts the upper face of aperture 17. In this position the upper flange 21 is radially compressed such that the annular 3~

sealing projections 31, 32, 33, 34 are each compressed into close contact with the surfaces opposi-te them. In this position fuel is prevented from flowing along the upper face of flange 21 by means of the first annular sealing projection 31 and is prevented from flowing along ~he bottom face of flange 21 by means of the third annular sealing projection 33. In the event either sealing projection 31 or 33 are inadequate to stop the flow of fuel, each is backed up by annular sealing projections 32 and 34, respectively. In addition to providiny for a seal-ing of the mounting of the fuel injection valve, the elastic seal ring 23 also acts as a restriction against lateral move-ment of the valve within the insertion aperture 17 and thereby keeps the cylinder 19 aligned with passage 18.
To check against the inadvertent omission of the elastic sealing ring 23 during the mounting procedure the cylindrical section 19 is equipped with a channel 40 cut in its upper face 35 as shown in Figure 10. Should the elastic sealing ring 23 be accidentally omitted, fuel will rèadily flow through the channel 40 and out the insertion aperture 17 and be easily detected.
Once each of the fuel injection valves V has been mounted within the fuel supply unit 5 and securely fastened to the supply units by means of the holding bracket 24 the entire assembly as shown in Figure 2 is then mounted on the engine. The nozzle ends 36 of the fuel injection valves are fitted with a circular sealing member 4 and inserted within an aperture 16 in the upper surfaces of the intake manifold Mi. The assembly is then bolted to the intake manifold by means of mounting bolts 13 which are inserted through apertures in support arms 11 which extend outward ~2~3~

from the fuel supply unit 5 and are threaded into corresponding mounting apertures in a support base 12 Eormed integrally with the intake manifold. An insulating material 14 may be inter-posed between the manifold and fuel supply unit as shown in Figure 1.
When finally mounted the nozzle end 36 of each of the fuel injection valves V is in communication with both the intake passage 3 of the intake manifold Mi and the intake port 2 of the engine E.
Having thus described my invention, numerous equiv-alents and alterations which do not depart from the invention will be obvious to those of ordinary skill in the art and is not intended to be limited to the embodiments described above, but is to be of the full scope of the appended claims.

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Claims

What is Claimed

1. A fuel injection system for a multi-cylinder engine having an intake manifold with a fuel injection valve for each cylinder, comprising; a fuel supply unit having insertion apertures for receiving each injection valve, a holding bracket for supporting each injection valve, an elastic sealing ring positioned in each said insertion aperture for sealing between said fuel injection valve and said fuel supply unit, said fuel injection valves supported in place with respect to the fuel supply unit by means of the holding bracket, a vibration absortion member supporting each fuel injection valve on said holding bracket; means connecting said holding bracket to said fuel supply unit for mounting that combination with the injection valves to the engine as a unit.

2. A fuel injection system for an engine as in Claim 1 wherein the end of the fuel injection valve mounted within the fuel supply unit has the configuration of two cylindrical sections connected by a circular flange which extends outward from the junction of the cylindrical portions, the circular flange being of a lesser diameter than the inser-tion aperture in the fuel supply unit.

3. A fuel injection system for an engine as in Claim 2 wherein the elastic sealing ring is of a circular configuration and has an upper and lower inwardly radial flange positioned on either side of said circular flange on the injection valve, said upper flange having a plurality of annular sealing projections.

4. A fuel injection system for an engine as in Claim 3 wherein the axial thickness in a natural state of the upper inward radial flange of the elastic sealing ring is of a slightly larger dimension than the length of the upper cylindrical section of said fuel injection valve, and the radial width of the upper inward flange is of a slightly lesser dimension than the distance between the outer peri-pheral surface of the upper cylindrical section and the inner peripheral surface of the insertion aperture in the fuel supply unit.

5. A fuel injection system for an engine as in Claim 2 wherein a channel is cut radially across the upper surface of the upper cylindrical section.

6. A fuel injection system for a multi-cylinder engine having an intake manifold with a fuel injection valve for each cylinder, comprising; a fuel supply unit having aper-tures for receiving each injection valve, a holding bracket having means for supporting each injection valve, and means for releasably connecting said mounting bracket to said fuel supply unit with the injection valves in position for mounting to the engine as a unit.

7. The fuel injection system of Claim 6 wherein a sealing means is provided in each said aperture in the fuel supply unit for sealably connecting each fuel injection valve to the said fuel supply unit.

8. The fuel injection system of Claim 7 wherein each fuel injection valve is provided with a cylindrical end portion and an outwardly extending flange therebelow for insertion into said aperture, and said sealing means comprises an elastic sealing ring position around said cylin-drical end portion and supported on said flange.

9. The fuel injection system of Claim 8 wherein said sealing ring includes a portion fitting over and con-necting the ring to said flange.