JPH03271559A - Fuel distributing pipe - Google Patents

Abstract

PURPOSE:To eliminate necessity for a conventional fuel filter by housing a tube unit filter element in a tube unit housing of a distributing fuel pipe, which supplies fuel to a plurality of fuel injection valves, and arranging a vortex generating unit in an opening of a fuel introducing side end part of this element. CONSTITUTION:A fuel supply device 1 is constituted by mounting an injector 6 and a pulsation damper 7 on a delivery pipe 10, which is a distributing fuel pipe, and further communication-connecting a fuel pump 4 and a pressure regulator 8. this delivery pipe 10 is formed in almost a cylindrical body by a housing 11, on both ends of which flange parts 11a, 11b are formed, to house a filter subassembly 20 in hollow parts 11c, 11d, 11e formed in stepped shape, and this assembly 20 is supported through supporting members 23, 24 by connecting supporting plates 12, 13 by a bolt to the flange parts 11a, 11b of the housing 11. The supporting member 24 is formed by providing a pillar unit 24c of triangular section which functions as a vortex generating unit relating to a flow of fuel.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to fuel distribution conduits for use in fuel-injected internal combustion engines.

[Prior Art] A fuel supply system for a fuel injection type internal combustion engine is generally configured such that fuel in a fuel tank is supplied by a fuel pump to a plurality of fuel injection valves via a fuel filter and a fuel distribution conduit. has been done. For example, as shown in FIG. 7, fuel in the fuel tank 3 is introduced into a fuel distribution pipe or delivery pipe 10p, and a fuel injection valve or injector 6 provided for each cylinder of the internal combustion engine 2 (in FIG. (only one of which is shown) and the cold start injector 6a.

Fuel is injected into the intake pipe 9 from the injector 6.6a, and the amount of fuel injection is controlled based on the injection time. Therefore, even if the injection time is the same, the fuel injection amount will be different when the fuel pressure is high and low.

Therefore, the pressure of the fuel supplied to the injector 6.6a is controlled by a pressure regulating valve, that is, a pressure regulator, so that the pressure of the fuel supplied to the injector 6.6a becomes a constant pressure difference with respect to the pressure in the intake pipe 9 where the fuel is injected.
The fuel is returned to the fuel tank 3 via a return pipe. Furthermore, when the injector 6 injects fuel into each cylinder in turn, the fuel pressure within the delivery vibrator 10p fluctuates, and the pressure decreases and increases repeatedly with each injection, resulting in pressure pulsations, which results in an appropriate injection amount. Control becomes difficult. For this purpose, a pulsation damper 7 is provided.

Regarding the fuel distribution in the fuel co-feeding device 1p, a top feed system in which fuel is supplied from the axial end of the injector 6 as shown in FIG. 7 is popular. On the other hand, recently, a side feed system has been adopted in which fuel is supplied from the side of the fuel injection valve, such as the fuel supply conduit described in Japanese Patent Application Laid-Open No. 59-34473.
According to this method, the heated fuel injection valve can be cooled by the supplied fuel.

[Problems to be Solved by the Invention] In any of the above fuel supply systems, the fuel filter 5 is arranged as shown in FIG. There is. That is, although strict filtration standards are required for the fuel supplied to the injector 6, the fuel filter 5 that satisfies the filtration standards is provided downstream of the fuel pump 4 and upstream of the delivery vibe 10p. .

However, this fuel filter 5 filters not only the fuel supplied from the fuel tank 3 to the injector 6 via the delivery vibe 10p, but also the fuel that flows back from the delivery vibe 10p to the fuel tank 3 via the pressure regulator 8. Therefore, the required filtration area becomes large, and the size of the device cannot be avoided. Further, as shown in FIG. 7, the fuel filter 5 is separate from other devices and is located in the engine compartment of the vehicle.
(not shown), installation space must be secured. In addition, the above-mentioned Japanese Patent Application Laid-Open No. 1983-
In Japanese Patent No. 34473, a filter member is provided around the fuel injection valve, but this is similar to the filter member provided at the inlet port of a top-feed type fuel injection valve.
It prevents objects that may be mixed in between the fuel filter and the fuel injection valve from entering, and has a smaller filtration area, which is different from the fuel filter 5 shown in FIG. 7.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a fuel distribution conduit that is used in a fuel supply system for a fuel injection type internal combustion engine and also functions effectively as a fuel filter.

[Means for Solving the Problem] In order to achieve the above object, the present invention provides a fuel distribution conduit that supplies fuel from a fuel tank to a plurality of fuel injection valves.
A cylindrical housing, a cylindrical filter element housed in a hollow part of the housing, and both axial ends of the filter element supported in the housing in a liquid-tight manner, and an outer wall surface of the filter element and the inside of the housing. The housing includes a support member that forms a fuel chamber between the housing and the fuel chamber, and a vortex generator disposed in an opening at an end on the fuel introduction side of both axial ends of the filter element. A communication hole is formed that communicates with the chamber and supplies the fuel to the fuel injection valve.

The vortex generating body in the fuel distribution conduit may be a pillar formed integrally with or separately from a support member disposed at the fuel introduction side end of the filter element, and installed over the opening at the fuel introduction side end of the filter element. It has a body and can be formed into various cross-sectional shapes suitable for vortex generation.

The filter element in the fuel distribution conduit may have a gradient-type laminated filter structure in which a plurality of layers of paper, nonwoven fabric, ceramic, etc. are laminated so as to give a gradient in the pore size distribution, or a density gradient-type filter structure in which a resin material is used. It is recommended to form the

[Operation] A plurality of fuel injection valves are installed in the fuel distribution conduit provided with the above filter element and connected to the fuel tank. Thus, the fuel supplied from the fuel tank to the fuel distribution conduit flows into the cylindrical body of the filter element through the vortex generator, and a continuous vortex is formed within the fuel. This vortex collides with the inner wall of the filter element, and dust and the like adhering to the inner wall are peeled off. The fuel is filtered by the filter element while reaching the fuel chamber from the cylinder, and the filtered fuel is injected from the fuel injection valve and consumed.

On the other hand, the excess fuel is not filtered by the filter element and flows back into the fuel tank as it is together with the separated dust and the like. That is, only the fuel consumed via the fuel injection valve is filtered by the filter element in the fuel distribution conduit.

[Embodiments] Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

Figure 's1 shows a delivery pipe 10 as an embodiment of the fuel distribution conduit of the present invention, to which an injector 6 and a pulsation damper 7 are installed as shown in Figure 2.
Furthermore, it is connected to the fuel pump 4 and the pressure regulator 8 to constitute a fuel supply device 1. The delivery vibe 10 shown in FIG. 1 is a substantially cylindrical body made of metal such as aluminum or iron, and includes a housing 11 with flanges 11a and 11b formed at both ends. Note that the housing 11 is not limited to a cylindrical body, but can be formed in various cross-sectional shapes, and may be made of synthetic resin. The hollow part of the housing 11 is I
It is formed in a stepped shape as shown by lc, lid, and lie, and the side wall of the housing 11 has communicating holes 11f, 11g, 1 for mounting the fuel injection valve 6 shown in FIG. 2 in the radial direction.
lh is formed and opens into a medium-diameter hollow portion 11d.

The communication holes 11f and the like are formed according to the number of fuel injection valves 6 to be installed, and FIG. 1 shows a part of them as an example.

A filter subassembly 20 is accommodated in the hollow portions lie, lid, and 11e of the housing 11, and a filter element 21 extends in the axial direction. Then, the support plates 12 and 13 made of the same material as the housing 11 are attached to the flange portions 11a and 11a of the housing 11 by bolts (not shown) so as to be in close contact with both ends of the filter subassembly 20.
11b. Communication holes 12a and 13a are bored in the center of the support plates 12 and 13, respectively.
An inlet pipe 14 and an outlet pipe 15 having the same inner diameter are fixed by welding or brazing. A sealing material is applied between the support plates 12, 13 and the ends of the housing 11, or they are joined via a gasket, so that the ends of the hollow portions 11c and 11e are sealed. Additionally, a mounting flange 16 is provided on the body of the housing 11.
is provided and fixed to the main body of the internal combustion engine 2 with bolts or the like. Although only one mounting flange 16 is shown in FIG. 1, a plurality of mounting flanges may be provided if necessary.

As is clear from the perspective view of FIG. 3, the filter subassembly 20 includes a cylindrical filter element 21 housed in a holding frame 22, and supporting members 23, 24 fixed to both ends of the cylindrical filter element 21. The filter element 21 is a cylindrical body formed of a resin material into a density gradient type filter structure,
It is configured to have a density distribution from coarse to dense from the hollow portion 11c, lid, and tie toward the outer wall surface. As the resin material, polyacetal, polyamide, 66 nylon, polyv-pyrene, fluororesin, polyester, cellulose acetate, etc. are used.

According to the density gradient type filter element 21 formed of such a resin material, generation of separated long fibers and fine fibers can be prevented compared to the conventional filter element using natural fibers. Moreover, it can be formed into a small size and can be easily formed into a cylindrical shape. Note that the filter element 21 may have a gradient-type multilayer filter structure in which a plurality of layers of paper, nonwoven fabric, ceramic, or the like are stacked so that the pore size distribution has a gradient.

The filter element 21 is housed and held in a holding frame 22 as shown in FIG. This holding frame 22 has a plurality of annular members connected in the axial direction by a plurality of columnar members,
It has a cylindrical structure as a whole, and the sides are shaped like a lattice. The thickness of the grid and the number of openings formed are
The holding frame 22 is set based on the pressure loss allowed for the fuel pressure request value in the fuel supply device 1 shown in FIG. Although it is made of a resin with excellent heat resistance and gasoline resistance such as polyacetal, it may also be made of a metal material such as stainless steel.

The support member 23 is made of a nonferrous metal with excellent heat resistance and gasoline resistance, and is formed into an annular shape, and its inner diameter is set so that the holding frame 22 is fitted therein.

Note that it may be formed of an elastomer or the like having excellent heat resistance and gasoline resistance. The outer diameter of the support member 23 is set to a value that allows it to be press-fitted or loosely fitted into the small-diameter hollow portion tic of the housing 11.

As shown in Figure 14ii4, the support member 24 is a dish-shaped member with an opening 24a in the center of the bottom divided into two via a column 24c, and is made of heat-resistant, gasoline-resistant material such as polyacetal, 66 nylon, or fluororesin. Made of resin with excellent properties. The cross-sectional shape of the column 24C is triangular as shown in FIG. 1, and the side surface of the column 24C is perpendicular to the fuel flow. The diameter of the opening 24a of the support member 24 is formed to approximately match the diameter of the opening of the filter element 21. In addition, the above-mentioned inlet pipe 14
The inner diameter of the outlet pipe 15 and the inner diameter of the communication holes 12a and 13a of the support plate 12.13 are set to be equal to the inner diameter of the filter element 21 and the gap between the passages. The inner diameter of the stepped portion 24b of the support member 24 is set such that the holding frame 22 is fitted therein. The outer diameter of the support member 24 is smaller than the inner diameter of the large diameter hollow part lie of the housing 11, and is set so that an annular space is formed between the hollow part lie and the support member 24.

The filter subassembly 20 is constructed by joining each component having the above configuration. That is, after the filter element 21 is housed in the holding frame 22, the holding frame 22 is fitted onto the supporting members 23, 24 and bonded with a gasoline-resistant adhesive such as epoxy resin. In addition, the support member 23.2
4 and the holding frame 22 are both made of resin, they can be integrated by thermal welding or ultrasonic welding.

Thus, the filter subassembly 20 includes a hollow portion 11c of the housing 11 to which the support plate 13 is joined in advance;
It is accommodated in the lid and lie. When the distal end surface of the filter subassembly 20 comes into contact with the support plate 13, the support member 23 is fitted into the small diameter hollow part 11C of the housing 11, and at the same time, the support member 24 is fitted into the large diameter hollow part 11e and the middle diameter part 11C. It comes into contact with the stepped part of the hollow part lid. Thereby, an annular fuel chamber 17 is formed between the hollow portion lid and the filter element 21. And support member 2
An O-ring 18 is accommodated in the annular space between the hollow part 4 and the hollow part lie. The O-ring 18 is made of nitrile rubber (NBR), fluororubber, or the like, which has excellent gasoline resistance, and is housed in the annular space to seal between the support member 24 and the housing 11. After that, the support plate 12 is joined to the flange portion 11b of the housing 11 with bolts (not shown), and the assembly of the delivery vibe 10 (
Complete.

The delivery vibe 10 having the above configuration is interposed between the fuel pump 4 and the pressure regulator 8, as shown in FIG. 2, to constitute the fuel supply device 1. In this embodiment, it is of course unnecessary to provide the fuel filter 5 shown in FIG. 7. Then, when the internal combustion engine 2 is started and the fuel pump 4 is driven, the fuel in the fuel tank 3 is delivered to the delivery vibe 1o. As a result, fuel flows into the hollow portion of the filter element 21 from the inlet pipe 14 via the support member 24 as shown by the arrow in FIG. At this time, the columnar body 24c functions as a vortex generator for the fuel flow. That is, column 2
An asymmetric stable vortex train is generated downstream of 4c. This vortex collides with the inner wall of the hollow portion of the filter element 21, and since the flow velocity of the fuel changes depending on the operating state of the internal combustion engine 2, dust and the like adhering to the inner wall are peeled off. Then, the fuel flows outward from the hollow portion of the filter element 21 and is supplied to each injector including the injector 6 through the communication holes if, fig, and llh.

Surplus fuel that is not injected from these injectors passes through the hollow part of the filter element 21 together with separated dust and the like, is sent out from the outlet pipe 15 to the pressure regulator 8, and then flows back into the fuel tank 3.

Thus, the density gradient type filter structure of the fuel passing through the filter element 21 reliably captures dust and the like contained in the fuel, and the fuel is effectively filtered. Furthermore, since the inner wall of the hollow portion of the filter element 21 is constantly cleaned by the vortex as described above, good filtration efficiency is ensured. Note that if fuel filtration is required for parts such as the pressure regulator 8 disposed downstream of the delivery pipe 10, a filter member such as a wire mesh may be provided depending on the filtration standards required for each part. do it. Further, the fuel filtered by the filter element 21 is transferred to the injector 6 and the cold start injector 6a.
Only the amount of fuel that is supplied to the internal combustion engine 2 via the
It is about 1/10 to 1/10. Therefore, the required filtration area is reduced accordingly, and the filter element 21
Has excellent filtration performance due to its density gradient filter structure.
The filter element 21 is significantly smaller than the filter element of a conventional fuel filter. Furthermore, since the filter subassembly 20 can be easily taken out by removing the support plate 12, the clogging status of the filter element 21 can be visually checked and can be replaced as necessary.

FIG. 5 shows a support member 240 according to another embodiment of the present invention, in which a resin main body 241 and a metal vortex generator 24 are provided.
2 is fitted. The main body 241 is shown in Fig. 5 (B).
As shown in the figure, it is a cylindrical body with an annular step 241a formed in the center, and the vortex generator 24 is formed by press-fitting, caulking, etc. into the hollow part.
2 is fixed in contact with the annular stepped portion 241a.

The vortex generator 242 has two columns 242a and 2 with a triangular cross section.
42b intersect to form a cross shape, and is made of a metal material with excellent heat resistance and gasoline resistance.

On the other hand, the main body 241 is made of the same material as the support member 24 shown in FIG.

Note that the main body 241 may be made of metal and the vortex generator 242 may be made of resin. Thus, the support member 240 of this embodiment is arranged so that the fuel flows from the left to the right in FIG. .

Columns 24c, 242a, 2 in the above two embodiments
The cross-sectional shape of 42b is triangular, but as shown in FIGS. 6(A) and (B), it can have various cross-sectional shapes suitable for generating a vortex street. In FIG. 6, columns 243, 24
4 are arranged so that the fuel flow is from the left to the right in the figure.

Although the above-described embodiment relates to a fuel distribution conduit used in a top-feed type fuel supply device, it can be similarly applied to a fuel distribution conduit used in a side-feed type fuel supply device.

[Effects of the Invention] Since the present invention is configured as described above, it produces the effects described below.

That is, since the filter element is housed within the fuel distribution conduit, the conventional fuel filter becomes unnecessary, and the installation space and installation man-hours can be reduced. In addition, the filter element is configured to filter only the fuel consumed through the fuel injection valve, and since the required filtration area is small, the filter element can be made small, and therefore the fuel distribution The filter element can be accommodated without making the conduit particularly large. In particular, a vortex is formed in the fuel flowing into the filter element by the vortex generator provided at the axial end of the filter element, and this vortex constantly cleans the inner wall of the filter element, resulting in good filtration performance. Secured.

In addition, if the above filter element has a gradient-type laminated filter structure or a density-gradient filter structure made of a resin material, and the density distribution is coarse on the fuel introduction side and dense on the discharge side, it can handle dust of various sizes. can be captured effectively.

[Brief explanation of drawings]

FIG. 1 is a vertical sectional view of a fuel distribution conduit according to an embodiment of the present invention, FIG. 2 is an overall configuration diagram of a fuel supply device equipped with the fuel distribution conduit, and FIG. FIG. 4 is a perspective view of a support member used in the fuel distribution conduit; FIG. 5A is a perspective view of a support member according to another embodiment of the present invention; FIG. 5B is a perspective view of a filter subassembly; ) is a sectional view taken along the line B-B of FIG. 5(A), FIGS. 6(A) and 6(B) are sectional views of an embodiment of the columnar body constituting the vortex generator, and FIG. 7 is a sectional view of the conventional columnar body. 1 is an overall configuration diagram of a fuel supply device of FIG. 242a. 242b. 243゜244...Column

Claims (1)

[Claims] (1) In a fuel distribution conduit that supplies fuel from a fuel tank to a plurality of fuel injection valves, a cylindrical housing, a cylindrical filter element housed in a hollow part of the housing,
a support member that liquid-tightly supports both axial ends of the filter element in the housing and forms a fuel chamber between an outer wall surface of the filter element and an inner wall surface of the housing; and a support member that supports both axial ends of the filter element in a liquid-tight manner; a vortex generator disposed at an opening at an end on the fuel introduction side of the part, and a communication hole that communicates with the fuel chamber and supplies the fuel to the fuel injection valve is formed in the housing. Features a fuel distribution conduit.