JP3217775B2 - Fuel delivery pipe - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a fuel delivery pipe, and more particularly, to a fuel delivery pipe that effectively reduces fuel pulsation.

[0002]

2. Description of the Related Art In a fuel supply system of an automobile engine, a pump pumps fuel through a fuel supply pipe to an injector, and the injector injects an appropriate amount of fuel into an intake manifold of the engine. In this type of fuel supply system, it is known as a drawback that every time the injector opens and closes, a fuel pulsation phenomenon appears remarkably in the piping. The vibration caused by the pulsation of the fuel causes a problem that the vibration is transmitted as noise from under the floor of the vehicle body through the fuel pipe. Therefore, various improvements for reducing fuel pulsation have been proposed.

For example, it is most widely adopted that a damper for reducing pulsation is incorporated in a fuel pipe and the pulsation is attenuated by the damper.

Attempts have also been made to provide a damper inside a fuel delivery pipe for distributing and supplying fuel to an injector. A prior art of this kind is disclosed in US Pat. No. 5,617,827. It has been known.

[0005]

However, in a conventional delivery pipe having a built-in damper, a structure for fixing the gas-filled damper to the delivery pipe main body and a seal structure for the damper are required. There is a problem that increases.

For example, in the aforementioned US Pat. No. 5,617,
In No. 827, the damper body incorporated in the delivery pipe has a sealed structure in which two pieces are joined, and a seal structure over the entire outer peripheral portion of the joined portion is required to ensure the airtightness of the damper body. If brazing is used to fix the damper having the sealed structure to the delivery pipe, the gas inside expands when the damper is heated, and the pressure deforms the damper. Therefore, in the above-mentioned US Pat. No. 5,617,827, a special support mounting structure is required to fix the damper to the delivery pipe main body, and there is a disadvantage that the configuration becomes complicated and the cost increases.

Accordingly, an object of the present invention is to solve the above-mentioned problems of the prior art and to provide a highly reliable damper in a delivery pipe without using a special mounting support structure for a member functioning as a damper. Another object of the present invention is to provide a fuel delivery pipe capable of reducing the number of parts and effectively absorbing a pulsation.

[0008]

According to a first aspect of the present invention, there is provided a fuel delivery pipe for supplying fuel, which is fed from a fuel supply system through a fuel supply pipe, to an injector. In the main body case, a damper member made of a metal tube having a flat circular cross section in which both ends are hermetically sealed and gas is sealed inside is housed, and both ends of the damper member are brazed to the main body. It is characterized by being fixed to a case.

According to a third aspect of the present invention, there is provided a fuel delivery pipe for supplying a fuel supplied from a fuel supply system through a fuel supply pipe to an injector, wherein both ends of the delivery pipe are sealed with blind plugs in a main body case. A damper member comprising a bellows-shaped tube in which gas is sealed is accommodated so as to be able to expand and contract in the axial direction. Characterized by having a narrow portion narrower than the outside diameter in the longitudinal direction.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of a fuel delivery pipe according to the present invention will be described below with reference to the accompanying drawings. First Embodiment FIG. 1 is a sectional view showing a first embodiment of a fuel delivery pipe according to the present invention. 10 is a delivery pipe, 11 is a fuel pipe, and these constitute a fuel supply device of a returnless system. Fuel in a fuel tank (not shown) is discharged from a pump and is fed to a delivery pipe 10 through a fuel pipe 11.

In this embodiment, the main body case of the delivery pipe 10 is formed of a rectangular cross-section pipe formed by joining a metal lower case 12 and an upper case 13 by brazing. The lower end of the fuel pipe 11 is connected to the upper case 13, and brackets 14a and 14b for mounting are integrally provided.
A required number of fuel supply ports are formed at the bottom of the lower case 14, and an injector mounting part 15 for mounting an injector (not shown) is inserted into the fuel supply port.

FIG. 2 shows the damper member 20 housed in the main body case of the delivery pipe 10. The damper member 20 is basically made of an elastic metal material such as iron, stainless steel or an alloy thereof, which is relatively easy to process, and a rigid thin tube is used as the tube itself. It is. For these tubes, conventional thin metal tubes used in a fuel supply system or an exhaust system of an automobile can be diverted.

As shown in FIG. 2, one end 21 of the damper member 20 is caulked and crushed into a plate shape, and then sealed by welding. This damper member 20
The other end portion 22 is not deformed while the cross-sectional shape is circular, and a sealing screw mounting member 23 having a female screw portion 23a is mounted thereon, and screwed to the female screw portion 23a as shown in FIG. A hermetic seal is provided by attaching a sealing screw 29, and a gas such as air is sealed inside.

The pressure receiving portion 5 of the damper member 20 except for both end portions 21 and 22 is compression-processed so that the cross section becomes a flat circle.
5 substantially functions as a damper. In the damper member 20, after confirming that there is no gas leakage by performing an airtight inspection on the crushed end portion,
The sealing screw 29 is hermetically sealed to ensure sealing reliability.

As shown in FIG. 1, the length of the damper member 20 is set to be substantially the same as the length of the delivery pipe 10, whereby both ends of the damper member 20 are brazed. With this, it can be fixed directly to the main body case. In this embodiment, as shown in FIG. 3, one end of the lower case 12 has a sealing screw mounting member 2 at a position in contact with an edge of the upper case 13.
3 is formed. Therefore, the damper member 20 can be inserted from the hole 24 after the lower case 12 and the upper case 13 are assembled. Further, as shown in FIG. 4, on the opposite side, the edge of the upper case 13 and the inner side surface of the lower case 12
6 are formed. Therefore, when the damper member 20 is inserted, the damper member 2
Since the end 21 crushed into a 0-plate shape just comes into contact with the screw mounting member 23 for sealing, the positioning and temporary attachment of the damper member 20 can be performed simultaneously with the insertion. Becomes Brazing can be performed immediately in the state of the temporary brazing. This brazing may be performed on a portion indicated by reference numeral 28 in FIGS. Thereby, the lower case 12, the upper case 13, and the damper member 20 can be brazed at a time.

Next, the operation and effect of the fuel delivery pipe of the first embodiment configured as described above will be described. When fuel discharged from a pump (not shown) flows through the fuel pipe 11 and is introduced into the delivery pipe 10, the fuel is distributed from the delivery pipe 10 to an injector (not shown) attached to the injector mounting portion 15. You. The opening and closing operation of each injector is controlled by a control unit (not shown) at a timing according to the operating state of the engine. That is, when the injector is opened, fuel is ejected from the injector while the injector is open, and when the injector is closed, fuel injection is shut off. In this fuel supply device, a returnless system in which a return pipe for returning fuel to the tank is not provided is employed. Therefore, by repeating the opening and closing operation of the injector, the fuel in the fuel pipe 11 and the delivery pipe 10 is supplied with a pressure lower. Pulsation will occur.

The pressure fluctuation caused by the pulsation of the fuel acts on the damper member 20 built in the delivery pipe 10 and deforms the damper member 20 in which gas is sealed. In this damper member 20, both ends 21, 2
2 has rigidity, but since the pressure receiving portion 25 has a flattened cross section, the pressure receiving area which directly receives the pressure fluctuation can be widened, and can expand and contract in the short axis direction in which the pressure acts. The structure is easy to deform. Therefore,
The pulsation can be effectively absorbed by the deformation of the damper member 20.

The damper member 20 not only excels in the pulsation absorbing function, but also exhibits the following advantages when brazed to the delivery pipe 10.
That is, since the damper member 20 is a seamless pipe, no seal is required. Further, at the time of brazing, since the damper member 20 can be formed without being sealed with the sealing screw 29, even if the gas inside is heated by the heat of the brazing, it is discharged from the open end of the damper and deformed due to expansion of the gas. There is no. After the brazing is completed, the airtightness of the damper member 20 is ensured by plugging the sealing screw mounting member 23 with the sealing screw 29.

Second Embodiment FIG. 5 is a longitudinal sectional view showing a second embodiment of the fuel delivery pipe according to the present invention. The fuel delivery pipe 30 includes a damper member 32 using a bellows-shaped tube.

In FIG. 5, the main body case 33 of the delivery pipe 30 is a metal case having an integral structure in this embodiment. One end of the main body case 33 has a cover 3
4 and closed at the other end by a pipe joint 35.
Is inserted through an O-ring, and the pipe joint 35 is fixedly held to the main body case 33 by a holding plate 38. The pipe joint 35 has a male connection portion 36 which is bent outward and extends. A fuel pipe 37 connected to a pump (not shown) is connected to the male connection portion 36. A required number of fuel supply ports are formed in the main body case 33, and an injector mounting portion 39 for mounting an injector (not shown) is inserted into the fuel supply port.

As shown in FIG. 6, such a main body case 33 has an integral structure of an accommodating portion 40 having a substantially circular cross section and a portion 41 having a rectangular cross section. The storage section 40 having a substantially circular cross section has an inner diameter set slightly larger than the outer diameter of the damper member 32 so that the bellows-shaped damper member 32 is stored and a fuel passage is formed together with the rectangular cross section 41. Has become. The accommodation section 40 and the rectangular cross section 41 are connected via a narrow portion 46 smaller than the outer diameter of the damper member 32. The narrow portion 46 extends in the length direction of the main body case 33.

FIG. 7 is a perspective view showing a bellows-shaped damper member 32, and FIG. 8 is a longitudinal sectional view of the damper member 32. The damper member 32 is sealed by mounting blind plugs 44 on both ends of a bellows-shaped tube 42 made of resin, and a gas is sealed inside. As the blind plug 44, as shown in FIG. 9, an existing plug in which the fitting portion 45 has a plurality of steps in a bamboo shoot shape is preferable. According to such a blind plug 44, when the blind plug 44 is mounted on the tube 42, welding, welding, adhesion, or the like is not required, and high reliability and airtightness can be ensured only by press-fitting. This damper member 32 is made using a mold, but in order to combine a required number of short molds corresponding to the bellows portion and the straight pipe portion in a length direction so as to have a required length to form an entire mold,
Damper members 32 of different lengths can be easily manufactured. Therefore, even when the design is changed to a delivery pipe having a case main body 33 having a different length, a flexible response is possible without newly manufacturing a mold or the like.

The bellows-like damper member 32 is
In FIG. 5, the total length including the blind plugs 44 at both ends does not need to be so strict with respect to the length of the case main body 33.
It is enough to have enough play to expand and contract inside.

Next, the operation and effect of the second embodiment configured as described above will be described.

By repeating the opening and closing operation of the injector (not shown), the fuel pipe 37 and the delivery pipe 30
When pressure pulsation occurs in the fuel inside, the fluctuation of the pressure due to the pulsation acts on the damper member 32 built in the delivery pipe 30 and deforms the damper member 32 in which gas is sealed.

The damper member 32 according to the second embodiment
Because the bellows-shaped resin tube 42 is used as a main element, when the pressure fluctuates, it expands and contracts in the axial direction. The pulsation is effectively absorbed by the expansion and contraction in the axial direction. In addition, since the bellows-like configuration increases the pressure receiving area of the fluctuating pressure at a stroke, the pulsation absorbing performance can be greatly improved. In addition, since the damper member 32 is regulated by the narrow portion 46, even if pulsation occurs, the movement in the radial direction is suppressed, and the pulsation can be smoothly absorbed by expanding and contracting only in the axial direction.

FIG. 10 is a longitudinal sectional view showing another example of the second embodiment. In this embodiment, basically, all the members are made of a resin material, and the case body 50 is made of a resin. Also, the blind plug 4
4 are integrally formed, so that the number of parts and the assembly process can be rationalized. The damper member 32 itself is
It is the same as that of the embodiment of FIG. In this embodiment, since the damper member 32 is connected to the joint 51, a structure for preventing the movement of the damper is not particularly necessary. However, as shown in FIG. The movement may be prevented by making the diameter slightly larger than the diameter of the member 32 and forming a convex portion 52 extending in the axial direction on the inner surface.

[0028]

As is apparent from the above description, according to the present invention, a highly reliable damper can be provided to a delivery pipe without employing a special mounting support structure or a complicated sealing structure for a member functioning as a damper. The fuel delivery pipe can reduce the number of parts and effectively absorb the pulsation.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a fuel delivery pipe according to a first embodiment of the present invention.

FIG. 2 is a perspective view showing a damper member according to the first embodiment.

FIG. 3 is a sectional view showing a brazing structure of one end of the delivery pipe.

FIG. 4 is a sectional view showing a brazing structure of the other end of the delivery pipe.

FIG. 5 is a longitudinal sectional view showing a fuel delivery pipe according to a second embodiment of the present invention.

FIG. 6 is a sectional view showing an AA section in FIG. 5;

FIG. 7 is a perspective view showing a damper member according to a second embodiment.

FIG. 8 is a longitudinal sectional view of the damper member.

FIG. 9 is a side view showing a blind plug used for a damper member.

FIG. 10 is a longitudinal sectional view showing another example of the fuel delivery pipe according to the second embodiment of the present invention.

11 is a sectional view showing a section taken along line BB in FIG. 10;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Delivery pipe 11 Fuel pipe 12 Lower case 13 Upper case 15 Injector mounting part 20 Damper member 23 Blind plug 25 Pressure receiving part 30 Delivery pipe 32 Damper member 33 Main body case 35 Fitting 37 Fuel pipe 42 Bellows tube 44 Blind plug

Continuation of the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) F02M 55/00-55/02 F16L 55/04

Claims (3)

(57) [Claims] 1. A fuel delivery pipe for supplying a fuel which is fed from a fuel supply system through a fuel supply pipe to an injector, wherein both ends of the delivery pipe are hermetically sealed and a gas is sealed inside a main body case of the delivery pipe. A fuel delivery pipe containing a damper member formed of a metal tube having a flat circular cross section and fixing both ends of the damper member to the main body case by brazing. 2. The damper member has a plug mounting member on at least one end thereof to which a sealing plug can be mounted from the outside of the case. The plug is mounted after the damper member is brazed to the main body case. 2. The fuel delivery pipe according to claim 1, wherein the fuel delivery pipe is sealed. 3. A fuel delivery pipe for supplying fuel fed from a fuel supply system through a fuel supply pipe to an injector, wherein both ends of the delivery pipe are sealed by blind plugs in a main body case, and gas is sealed inside. A damper member formed of a bellows-shaped tube is housed so as to be able to expand and contract in the axial direction, and the main body case is smaller than an outer diameter of the housing portion that houses the damper member so as to be able to expand and contract in the axial direction. A fuel delivery pipe having a narrow portion in a length direction.