JPH0435575Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a fuel supply device for a fuel injection type engine, and more particularly to a measure for preventing a rise in temperature of fuel in a fuel passage supplying fuel to a fuel injection valve.

(Prior Art) Generally, in an engine that uses a fuel injection valve to supply fuel, the fuel injection valve and the fuel pump are connected through a fuel passage, and the fuel pump supplies the fuel from the fuel tank to the fuel injection valve. It is configured to forcefully feed fuel through the passage and inject it from the injection valve into the intake passage (for example, see Japanese Patent Laid-Open No. 58-20923).

Incidentally, in this type of engine fuel supply system, a part of the fuel passage is constituted by a so-called delivery pipe, and the fuel that is pressure-fed from the fuel pump to the pipe is further delivered from the pipe to each fuel injection valve. It is beginning to be distributed to In this case, it has conventionally been customary for the delivery pipe to be directly attached to the connecting portion at the rear end of the fuel injection valve or to the upper central portion of the engine.

(Problem to be solved by the invention) However, with the above-described conventional configuration, the temperature of the fuel in the delivery pipe rises due to the influence of the heat released from the engine and the ambient temperature in the engine room. As a result, bubbles (vapor) are generated in the fuel system, and together with the bubbles, a portion of the fuel in the fuel passage is pushed out from the injection valve into the intake passage, making it easy to cause the so-called percolation phenomenon. It is. Such problems are particularly likely to occur in the summer when the outside temperature is high, but when percolation as described above occurs, the amount of fuel injection becomes inconsistent, resulting in problems such as engine malfunction and poor startability. .

The present invention addresses the above-mentioned problems regarding engine fuel supply systems, and by partially improving the layout of the fuel passages that supply fuel to the fuel injection valves, it is possible to reduce the temperature of the fuel in the passages. The purpose is to prevent the occurrence of percolation in this manner.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides an engine having a fuel injection valve that injects fuel into the intake passage. It is characterized in that it is provided in the vicinity of the injected fuel adhesion part of the intake passage, that is, in the vicinity of the intake passage part or the surrounding area thereof to which the fuel injected from the injection valve adheres.

(Function) According to the above configuration, since a part of the fuel passage that supplies fuel to the fuel injection valve is provided in close proximity to the injected fuel adhering part of the intake passage, the injected fuel adhering to the injected fuel adhering part When vaporizes in the intake passage,
A portion of the fuel passage is cooled by the heat of vaporization, and as a result, the fuel temperature within the passage is reduced. Thereby, it is possible to effectively prevent the occurrence of percolation in the fuel system, and in turn, it is possible to prevent problems such as engine malfunction and poor startability.

(Example) Hereinafter, an example of the present invention will be described based on the drawings.

FIG. 1 shows a first embodiment in which a fuel supply device according to the present invention is applied to a rotary piston engine 1. As shown in the figure, in the engine 1, a housing 2 having a cocoon-shaped inner circumferential surface is provided. A substantially triangular rotor 3 is provided for planetary rotational movement,
The interior of the housing 2 is defined by the rotor 3 into a plurality of working chambers. An intake port 4 formed in the housing 2 and an intake pipe 5 connected thereto are provided as means for supplying intake air or mixture to the working chamber 2a which is in the intake stroke in the illustrated state. An intake passage 6 is formed by.

Furthermore, in this embodiment, the intake pipe 5 forming the intake passage 6 has a first portion 5 ₁ on the upstream side.
It is composed of three parts: a second part ₅₂ on the downstream side, and a _{third part 53 disposed} between these parts. A fuel injection valve 7 for injecting a predetermined amount of fuel into the intake passage 6 is installed in the intake passage 6, and a throttle valve 8 is provided in the third portion ₅₃ on the downstream side thereof. In this case, at the rear end of the fuel injection valve 7, one end 9a of a fuel passage 9 is provided which supplies fuel fed under pressure from a fuel pump (not shown) to the injection valve 7.
is connected, and in this state, the injection valve 7 is attached to the first part 51 in an inclined manner from above toward the intake downstream side, and the nozzle part 7a at the tip thereof is attached to the first part ₅₁ so as to face the The third portion located above 5 ₃
The fuel a is injected toward the pipe wall portion 5a at.

As a feature of the present invention, the fuel passage 9 that supplies fuel to the fuel injection valve 7 has a delivery pipe 9b that constitutes a part thereof and distributes fuel to the injection valve 7 as a fuel adhering portion of the intake passage 6. It is arranged in the axial direction of the rotor 3 (direction perpendicular to the plane of the paper) in close proximity to the tube wall portion 5a. That is,
A fuel injection valve 7 is provided in the third portion ₅₃ of the intake pipe 5.
The side to which the injected fuel a from the pipe adheres (pipe wall portion 5a side)
The delivery pipe 9b is inserted into the delivery pipe mounting portion _53a . In this case, the pipe 9b and the tube wall portion 5a are located close to each other so that heat can be efficiently conducted between them.

According to the above configuration, fuel discharged from a separately provided fuel pump (not shown) is first forced into the delivery pipe 9b through a predetermined passage portion (not shown) in the fuel passage 9, and then
The fuel is further distributed to the fuel injection valve 7, and then injected from the injection valve 7 into the intake passage 6 at a predetermined time,
It adheres to the pipe wall portion 5a of the third portion ₅₃ of the intake pipe 5.
Then, the fuel adhering to the wall portion 5a in this manner is sequentially vaporized and is supplied to the working chamber 2a of the engine 1 along with the intake air flow taken into the intake passage 6. In that case, when the fuel adhering to the pipe wall 5a vaporizes, the heat of vaporization cools the surrounding area of the wall 5a in the intake pipe 5;
In the above configuration, since the delivery pipe 9b is provided close to the pipe wall portion 5a that is cooled the most, the fuel distributed to the fuel injection valve 7 through the inside of the pipe 9b is also cooled at the same time. That will happen. Thereby, the temperature of the fuel in the fuel passage 9 can be lowered, and the occurrence of percolation can be prevented.

Further, according to the above configuration, the throttle valve 8 is disposed within the third portion ₅₃ constituting a part of the intake pipe 5.
is provided, and a delivery pipe 9 is attached to the delivery pipe attachment portion _53a formed in the third portion ₅₃ .
b is provided, the pipe 9b and the third portion ₅₃ are integrated, and the structure of this portion is simplified compared to the conventional one, and the rigidity of the peripheral portion is also improved. Furthermore, serviceability during engine disassembly and assembly is improved compared to the case where this type of mounting portion is disposed at the center of the upper surface of the engine.

In this embodiment, the delivery pipe 9b is arranged to face the injection port 7a of the fuel injection valve 7, but the position of the pipe 9b is not limited to this. The delivery pipe 9b is installed in close proximity to the third portion ₅₃ on the side where the fuel injection valve 7 is installed, that is, the side of the pipe wall 5b located opposite to the pipe wall 5, taking into consideration the piping between the pipes. It may also be a configuration.

On the other hand, FIG. 2 shows a second embodiment of the present invention, and in this embodiment, a _first and a second Two fuel injection valves 7 ₁ ′, 7 ₂ ′ are mounted to face each other, and a third portion 5 ₃ ′ on the downstream side of the first portion 5 ₁ ′ includes two fuel injection valves 7 1 ′, 7 ₂ ′. 7
A _first delivery pipe 9 1 b' for the first fuel injection valve 7 ₁ ' and a second delivery pipe 9 ₁ b' for the second fuel injection valve 7 2 ' respectively constitute a part of the fuel passage 9' that supplies fuel to the fuel injection valve 7 ₂ '. Pipes 9 _2b ′ are also provided facing each other.
In this case, while the fuel from the first fuel injection valve 7 ₁ ′ is injected toward the pipe wall portion 5 a ′ on the side where the second delivery pipe 9 ₂ b ′ is disposed, the second fuel injection valve 7 1 ′ is The fuel from the valve 7 ₂ ′ is injected toward the pipe wall 5 b ′ on the side where the first delivery pipe 9 ₁ b ′ is disposed, and the fuel adhering to each pipe wall 5 a ′, 5 b ′ is sequentially vaporized. The air is supplied into the engine 1' along with the intake air flow. In addition, the above-mentioned intake pipe 5
₁ ' is composed of the first to third parts ₅₁ ' to ₅₃ ', and the intake passage 6' is formed by these parts, which are the same as in the first embodiment. be.

Therefore, also in this case, each of the pipe wall portions 5
In the process of vaporizing the fuel adhering to a' and 5b', the fuel in each delivery pipe 9 ₁ b' and 9 2 b' is cooled by the heat of vaporization through each pipe wall part 5 a' and ₅ b'. Therefore, percolation caused by the rise in fuel temperature is effectively prevented, and the same effects as in the first embodiment can be obtained in other respects as well.

In each of the above embodiments, the intake pipes 5, 5'
are each composed of three parts, but it goes without saying that the present invention is not limited to such a structure.

(Effects of the invention) As described above, according to the engine fuel supply device according to the present invention, the fuel injected into the intake passage from the fuel injection valve adheres to the fuel adhesion part of the passage or the vicinity thereof. Since a part of the fuel passage is provided in the fuel passage, when the fuel adhering to the adhesion part vaporizes, the fuel temperature in the fuel passage can be lowered by the heat of vaporization, and as a result, the fuel temperature in the fuel passage can be lowered. Effects such as being able to prevent collation can be obtained.

[Brief explanation of drawings]

The drawings show the embodiments of the present invention.
FIG. 2 is a vertical cross-sectional view of the vicinity of the intake passage showing a fuel supply system for an engine according to the first embodiment, and FIG. 2 is a vertical cross-sectional view of the vicinity of the intake passage showing the fuel supply system for an engine according to the second embodiment. be. 1, 1'...Engine, 5a, 5a', 5b'...
Injected fuel adhesion part (pipe wall part), 6, 6'...Intake passage, 7, 7 ₁ ', 7 ₂ '...Fuel injection valve, 9, 9'...
...Fuel passage, 9b, 9 ₁ b', 9 ₂ b'... Part of the fuel passage (delivery pipe).

Claims (1)

[Scope of utility model registration request] An engine having a fuel injection valve that injects fuel into an intake passage, characterized in that a part of the fuel passage that supplies fuel to the fuel injection valve is provided close to a portion of the intake passage where the injected fuel is attached. fuel supply system for the engine.