JPH08261101A - Fuel pressure pulsation damping device - Google Patents

Abstract

PURPOSE: To eliminate the reduction in reliability to be caused by assembly, and to prevent the spatial disadvantage from being caused. CONSTITUTION: A first pipe 16 that is extended to the inside of a housing 12 and communicated with the connecting port 13 is connected to the nipple 14 that forms one end of the housing 12 of a fuel delivery pipe 11. A second pipe 17 is provided to the first pipe 16 through a boot 19 having a bellows 19a. A first fuel passage 23 is constituted by the interior of the first pipe 16, the interior of the boot 19, and the interior of the second pipe 17, and a second fuel passage 24 is constituted by the inside of the housing 12 and also by the outside space of the first pipe 16, the boot 19, and the second pipe 17. The pressure pulsation is chiefly damped by the boot 19. Since the mechanism for damping the pressure pulsation is provided inside the housing 12, the mechanism is integrated with the fuel delivery pipe 11, so that the reduction in reliability of the performance that would be caused by assembling another parts can be eliminated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel delivery pipe for use in an engine having a plurality of fuel injection valves and for distributing fuel to each fuel injection valve, and more specifically, to a fuel delivery pipe that may occur during fuel injection. The present invention relates to a fuel pressure pulsation damping device for damping fuel pressure pulsations.

[0002]

2. Description of the Related Art Conventionally, as one of fuel supply mechanisms for a multi-cylinder engine, there is one in which a plurality of fuel injection valves are arranged in an intake passage and fuel is injected from each fuel injection valve to a corresponding cylinder. . In this mechanism, a fuel delivery pipe is usually used to distribute the fuel from the fuel pump to each fuel injection valve. For example, as shown in FIG. 6, a fuel passage (not shown) is provided through the housing 52 of the fuel delivery pipe 51, and a socket portion 54 for mounting the fuel injection valve 53 is provided at a plurality of locations along the passage. Has been formed. Then, during operation of the engine to which the fuel delivery pipe 51 is attached, the fuel from the fuel pump is introduced into the fuel passage from one end of the housing 52 and flows through the passage. During this passage, the fuel is injected into each fuel injection valve 5
It is divided into three parts and is injected into each cylinder of the engine from here. Excess fuel is discharged from the other end of the housing 52 and returned to the fuel tank via the return pipe 55.

In such a conventional technique, a pressure regulator 56 for keeping the fuel pressure substantially constant is provided downstream of the fuel delivery pipe 51.
Further, a pulsation damper 57 for damping the fuel pressure pulsation is provided on the upstream side of the fuel delivery pipe 51. That is, the pulsation damper 57
As shown in FIG. 7, the moving body 58 and the diaphragm 5 are
9, a spring 60, a cap 61 and the like.
Then, the pulsation damper 57 causes the diaphragm 59 and the movable body 5 to move when the fuel pressure maintained by the pressure regulator 56 is pulsated by the fuel injection from the fuel injection valve 53.
The vibration of 8 plays a role of attenuating the pulsation.

[0004]

However, in the above prior art, the pulsation damper 57 is provided separately from the fuel delivery pipe 51, so that the pressure pulsation is damped. For this reason, the reliability of the performance due to the mutual assembly is not always reliable.

Further, since the pulsation damper 57 has to be provided so as to project outward from the housing 52 of the fuel delivery pipe 51, a significant space disadvantage is brought about. As a result, for example, another member cannot be installed at the installation location of the pulsation damper 57.

The present invention has been made to solve the above problems, and an object thereof is to provide a device for attenuating fuel pressure pulsation, which is integrated with a fuel delivery pipe so as to improve reliability by assembly. SUMMARY OF THE INVENTION It is an object of the present invention to provide a fuel pressure pulsation damping device capable of eliminating the decrease in fuel pressure and preventing a space disadvantage.

[0007]

In order to achieve the above object, in the invention according to claim 1, the fuel is introduced into the housing through the introduction port, and the same fuel is injected into the plurality of fuel injection valves. A fuel delivery pipe having a fuel passage for distributing the fuel into the housing, and a housing of the fuel delivery pipe, extending from the introduction port in a direction opposite to the introduction port, and introducing the fuel introduced from the introduction port to itself. A fuel pressure pulsation damping device comprising a pipe for passing through the inside and guiding to the fuel passage, and a flexible member provided in the middle of the pipe and deformable according to pressure fluctuations inside and outside the pipe. It is a summary.

Further, in the invention described in claim 2, in the fuel pressure pulsation damping device according to claim 1, the gist is that the flexible member has at least a bellows portion.

Further, the invention according to claim 3 is, in the fuel pressure pulsation damping device according to claim 1 or 2, characterized in that the flexible member is made of a rubber film.

In addition, in the invention according to claim 4, in the fuel pressure pulsation damping device according to any one of claims 1 to 3, at least the periphery of the flexible member is reinforced to reinforce the flexible member. The gist is that a means is provided.

In addition, in the invention described in claim 5, in the fuel pressure pulsation damping device described in any one of claims 1 to 4, a plurality of the flexible members are provided in the middle of the pipe. It is a summary.

[0012]

According to the first aspect of the invention, the fuel is introduced into the fuel passage from the introduction port through the inside of the pipe with the fuel injection valve attached to the housing of the fuel delivery pipe. Is distributed to each fuel injection valve in the process of flowing. Here, with the fuel injection from the fuel injection valve,
Alternatively, pulsation may occur in the fuel pressure with the introduction of fuel from the fuel pump or the like into the fuel passage.

However, according to the present invention, a flexible member which can be deformed according to pressure fluctuations inside and outside the pipe is provided in the middle of the pipe. Therefore, when pressure pulsation occurs, the flexible member is deformed, and the wave generated by the pressure pulsation can be attenuated by this deformation.

Further, since the flexible member constituting the mechanism for damping the pressure pulsation is provided in the housing of the fuel delivery pipe, the pulsation damper must be provided outside. In contrast, the mechanism for damping the pressure pulsation can be integrated with the fuel delivery pipe. Furthermore, this mechanism
It does not protrude outside the housing of the fuel delivery pipe.

According to the invention described in claim 2, in addition to the function of the invention described in claim 1, the flexible member includes:
Since at least the bellows portion is included, the bellows portion can be easily deformed. For this reason, the above operation becomes more reliable.

Further, according to the invention of claim 3,
In addition to the effect of the invention described in claim 1 or 2, since the flexible member is made of a rubber film, it can be easily deformed by following the pressure pulsation. For this reason, the above operation becomes more reliable.

In addition, according to the invention of claim 4,
In addition to the actions of the invention described in claims 1 to 3, the flexible member can be reinforced by the reinforcing means at least around the flexible member. Therefore, even when the flexible member is repeatedly deformed, or even when the flexible member is subjected to a relatively large pressure fluctuation, the strength of the flexible member is ensured and the flexible member is Not easily damaged.

Further, according to the invention of claim 5,
In addition to the effect of the invention described in claims 1 to 4, a plurality of the flexible members are provided in the middle of the pipe. Therefore, when the frequency of the pressure pulsation wave is different,
Attenuation of wave energy can be achieved according to the different frequencies.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the fuel pressure pulsation damping device of the present invention will be described below with reference to FIGS.

As shown in FIGS. 1 and 2, in this embodiment, the fuel pressure pulsation damping device is mainly constituted by the fuel delivery pipe 11. The housing 12 of the fuel delivery pipe 11 is formed in a long shape by a fiber reinforced resin (for example, a composite material made of polyamide resin and glass fiber) having excellent heat resistance and high rigidity. At one end of the housing 12 (the left end in the figure), there is a connection port 13 as an inlet for connecting a fuel pipe, and a nipple 14 made of the same material as the housing 12 has an O-ring 15 in between. While being fitted, it is heat-sealed to the housing 12. The other end (the right end in the figure) is simply a wall. That is, as the fuel delivery pipe 11 in this embodiment, what is called a returnless type is adopted. However, the return pipe may be separately connected to return the surplus fuel to the fuel pump.

The nipple 14 has its connection port 1
A first metal pipe 16 extending inside the housing 12 is connected so as to communicate with the housing 3. further,
A second pipe 17, which is also made of metal, is fixed in the housing 12 via a support piece 18 in a state of being separated from the first pipe 16 by a predetermined distance. These first
The pipe 16 and the second pipe 17 constitute a pipe according to the present invention.

In the middle of this pipe, that is,
A boot 19 that constitutes a flexible member is provided so as to connect the first pipe 16 and the second pipe 17. The boot 19 is made of a rubber film having gasoline resistance and heat resistance, and has a bellows portion 19a at the center thereof. Further, both ends of the boot 19 are fixed by crimping with clamps 21A and 21B. Further, on the outer periphery of the bellows portion 19a of the boot 19, along the valley of the bellows portion 19a, the bellows portion 1 is formed.
A coil spring 22 is provided as a reinforcing means for reinforcing 9a. The interior of the first pipe 16, the interior of the boot 19 and the interior of the second pipe 17 form a first fuel passage 23.

The space inside the housing 12 and outside the first pipe 16, the boot 19 and the second pipe 17 constitutes a second fuel passage 24. In the present embodiment, the second fuel passage 24 constitutes the fuel passage according to the present invention.

The fuel for operating the engine is
The fuel flows through a fuel pump, a fuel pipe (neither shown), and the connection port 13 into the first fuel passage 23. The fuel that has passed through the first fuel passage 23 is introduced into the second fuel passage 24 from the tip portion of the second pipe 17.

In the housing 12, in the middle of the second fuel passage 24, there are the same number as the number of cylinders of the engine (4 in the figure).
Socket portions 25 are formed so as to be separated from each other. Each socket portion 25 has a substantially cylindrical shape, and a fuel injection valve 26 is attached thereto. Each fuel injection valve 26
Is an electromagnetic valve that opens by energizing and injects fuel.

Next, the operation and effect of the fuel pressure pulsation device constructed as above will be described. The fuel pumped from the fuel pump is connected to the fuel pipe and connection port 13
Through the first fuel passage 23, and is introduced into the second fuel passage 24 from the tip portion of the second pipe 17. Then, the fuel is distributed to each fuel injection valve 26 while flowing through the second fuel passage 24. Here, the fuel injection valve 26
Pulsation may occur in the fuel pressure as fuel is injected from the fuel tank or fuel is introduced from the fuel pump or the like into the first fuel passage 23 or the like. However, in the present embodiment, the first fuel passage 2 is provided between the first pipe 16 and the second pipe 17.
A boot 19 that is deformable according to the pressure fluctuations of the third and second fuel passages 24 is provided. Therefore, when pressure pulsation occurs, the boot 19 is deformed, and the wave generated by the pressure pulsation can be attenuated by this deformation.

For example, when the fuel pressure pulsates due to the introduction of fuel from the fuel pump or the like into the first fuel passage 23, etc., and the pressure in the first fuel passage 23 increases momentarily. As shown in FIG. 3, the bellows portion 1 of the boot 19 is
9a expands. Due to this expansion, the wave generated by the pressure pulsation is attenuated and absorbed. On the other hand, when the fuel pressure pulsates due to the fuel injection from the fuel injection valve 26 and the pressure in the second fuel passage 24 increases momentarily,
As shown in FIG. 4, the bellows portion 19a of the boot 19 contracts. Then, due to this contraction, the wave generated by the pressure pulsation is attenuated and absorbed.

As described above, in this embodiment, the first and second pipes 1 provided in the fuel delivery pipe 11 are provided.
The pressure pulsation can be sufficiently damped by the 6, 17 and the boot 19 and the like. As a result, it is possible to avoid problems such as variations in fuel injection amount due to pressure pulsation. Further, since the mechanism for damping this pressure pulsation is provided inside the housing 12 of the fuel delivery pipe 11, unlike the prior art in which a pulsation damper had to be provided outside, a pressure pulsation damping mechanism. Can be integrated with the fuel delivery pipe 11. Therefore, in the present embodiment, it is possible to eliminate the deterioration in reliability of the performance caused by assembling each member separately.

Further, since this pressure pulsation damping mechanism does not project outside the housing 12 of the fuel delivery pipe 11, it is possible to prevent a space disadvantage. That is, it is possible to effectively utilize the space in the portion where the pulsation damper is conventionally provided.

In addition, in this embodiment, as the flexible member,
Boot 1 made of a rubber film and having a bellows portion 19a
It was decided to adopt 9. Therefore, the bellows portion 19a can be easily deformed according to the pressure pulsation, and the damping effect of the pressure pulsation can be made more reliable.

In addition, in this embodiment, the coil spring 22 is arranged on the outer periphery of the bellows portion 19a of the boot 19 along the valley of the bellows portion 19a.
Therefore, the boot 19 can be reinforced by the coil spring 22, and even when the boot 19 is repeatedly deformed due to pressure pulsation, or the boot 1
Even when 9 undergoes a relatively large pressure fluctuation, the strength of the boot 19 can be secured for a long period of time,
The occurrence of damage can be suppressed.

The present invention is not limited to the above embodiment, but may be configured as follows, for example. (1) In the above embodiment, both ends of the boot 19 are clamped to the first and second pipes 16 and 17 by the clamps 21A and 21B.
Although it was fixed with the boot, as shown in FIG.
The 9 may be fixed by simple fitting. Alternatively, another fixing method may be adopted.

(2) In the above embodiment, the boot 19 is the first
Although it is configured to be provided only at one place between the second pipe 16 and the second pipe 17, it may be provided at a plurality of places. With such a configuration, when the frequency of the pressure pulsation wave is different, it is possible to reduce the energy of the wave according to the different frequency.

(3) In the above embodiment, the second pipe 17 is used.
Is extended to the end portion (right end portion in the drawing) of the second fuel passage 24, but it does not necessarily extend to that portion, and can be embodied in the case where it extends halfway.

(4) In the above embodiment, the coil spring 22 is used as the reinforcing means, but other reinforcing means (eg insert) may be used. Further, the reinforcing means may be omitted.

(5) In the above embodiment, the rubber boot 19 having the bellows portion 19a is adopted as the flexible member. However, if it is deformable according to the pressure fluctuation inside and outside the pipe, it is simply You may use a cylindrical thing. Also,
The material is not limited to rubber and may be made of resin, metal or the like.

(6) In the above embodiment, the housing 12,
The nipple 14 and the like are made of a resin material, and the first and second
Although the pipes 16 and 17 are made of metal, the material of each member is not limited at all, and may be made of, for example, a resin material or a metal material other than them.

(7) A so-called side feed type pipe may be used as the fuel delivery pipe.

[0039]

As described above in detail, according to the fuel pressure pulsation damping device of the present invention, not only the pressure pulsation can be efficiently damped, but also by integration with the fuel delivery pipe, This has an excellent effect that it is possible to prevent deterioration of reliability due to assembly and prevent a disadvantage in space.

In particular, according to the invention described in claims 2 and 3, the effect of damping the pressure pulsation can be made more reliable. Further, according to the invention described in claim 4, it is possible to suppress damage to the flexible member.

Further, according to the invention of claim 5,
When the frequencies of the pressure pulsation waves are different, it is possible to achieve attenuation according to the different frequencies.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional view showing a main part of a fuel pressure pulsation damping device.

FIG. 2 is a cross-sectional view showing a fuel delivery pipe and the like.

FIG. 3 is a partial cross-sectional view showing the operation of a fuel delivery pipe or the like.

FIG. 4 is a partial cross-sectional view showing the operation of a fuel delivery pipe or the like.

FIG. 5 is a partial cross-sectional view showing a fuel pressure pulsation damping device in another example.

FIG. 6 is a perspective view showing a fuel delivery pipe and the like in the prior art.

FIG. 7 is a sectional view showing a pulsation damper according to a conventional technique.

[Explanation of symbols]

11 ... Fuel delivery pipe, 12 ... Housing, 13 ...
Connection port as an inlet, 16 ... a first pipe forming a pipe, 17 ... a second pipe forming a pipe, 1
8 ... Fuel injection valve, 19 ... Boot as flexible member, 19
a ... Bellows portion, 22 ... Coil spring as reinforcing means, 24 ... Second fuel passage as fuel passage.

Claims (5)

[Claims] 1. An inlet (1) is provided in a housing (12).
3) A fuel delivery pipe (11) having a fuel passage (24) for introducing the fuel through the fuel passage and distributing the fuel to a plurality of fuel injection valves (18), and the fuel delivery pipe (11). Housing (12)
Inside, from the inlet (13) to the inlet (13)
A pipe (16, 17) extending in a direction opposite to that for guiding the fuel introduced from the introduction port (13) to the fuel passage (24) through the inside thereof. , 17), and a flexible member (19) provided in the middle of the pipe (16, 17) and capable of deforming according to pressure fluctuations inside and outside the pipe (16, 17). 2. The flexible member (19) has at least a bellows portion (19a).
The fuel pressure pulsation damping device according to. 3. The fuel pressure pulsation damping device according to claim 1, wherein the flexible member (19) is made of a rubber film. 4. The reinforcing means (22) for reinforcing the flexible member (19) is provided at least around the flexible member (19). The fuel pressure pulsation damping device according to. 5. The fuel pressure pulsation damping device according to claim 1, wherein a plurality of the flexible members (19) are provided in the middle of the pipes (16, 17).