JPH05223038A - Fuel feeding device for internal combustion engine - Google Patents

Abstract

PURPOSE:To improve the starting property by feeding the sufficient pressurized air to a fuel injection valve immediately after an engine is started, and stably feed the pressurized air to the fuel injection valve after the engine is started. CONSTITUTION:The discharge side pipe 21 of an air pump 2 is communicated with an accumulating container 6 for preventing the occurrence of a pressure pulsation via a branch pipe provided with an electromagnetic opening/closing valve 31, and is communicated with an air gallery 8 via a communicating pipe 23. The opening/closing valve 31 is switched based on the on-signal of an ignition switch 42 and the engine rotating speed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improved fuel supply system for an internal combustion engine.

[0002]

2. Description of the Related Art For the purpose of improving fuel economy and exhaust gas purification performance, fuel atomization and atomization are promoted to stabilize combustibility. For example, there is one as shown in FIG. 5 (see Japanese Patent Laid-Open No. 63-106357). In the figure,
The air-assisted fuel injection valve 1 injects a fuel injection valve 1a that intermittently injects fuel, a mixing portion 1b that mixes fuel and atomizing air, and injects a fuel-air mixed fluid immediately above an intake valve opening. And an extension part 1c for On the other hand, the air pump 2 sucks in air from the upstream side of a throttle valve (not shown) and compresses and pressurizes it. Then, the pressurized air is regulated to a predetermined pressure by the regulator 7 and stored in the pressure accumulating container 6 in order to prevent the occurrence of pressure pulsation, and the air assist 8 is supplied from the air gallery 8 according to the control signal of the control unit 3. It is supplied to the fuel injection valve 1.

The fuel atomized by the assist air is directly above the intake valve 9 located in the combustion chamber 11 through the extension 1c which communicates the air assist fuel injection valve 1 with the intake valve opening 10. Is supplied to. The pressurized air not only contributes to atomization of the fuel, but also assists the transportation of the fuel in the extension portion 1c and improves the responsiveness related to the transportation of the fuel.

[0004]

However, in such a conventional fuel supply device for an internal combustion engine for supplying assist air, the air pressurized by the air pump 2 is first stored in the pressure accumulating container 6, Since it is configured to be supplied to the air-assisted fuel injection valve 1 via the pressure accumulating container 6, the volume of the piping system on the downstream side of the air pump 2 in which the pressure accumulating container 6 has a large specific gravity becomes large.
Therefore, immediately after driving of the air pump 2 such as when the engine is started, the air pressure is not sufficiently high, and even if the air pump 2 pressurizes, the air gallery 8 is affected by the volume of the pressure accumulating container 6. Therefore, the air pressure in the air does not rise easily (see FIG. 4), and the air pressure of the assist air does not rise easily. As a result, not only is it difficult to atomize the fuel, but also the responsiveness related to the transportation of the fuel in the extension portion 1c is reduced, and the delay in the transportation of the fuel is significantly increased, and there is a problem that the starting time is long.

The present invention has been made by paying attention to such a conventional problem, and by providing a structure in which sufficient pressurized air is supplied to the air assist fuel injection valve immediately after the engine is started, An object of the present invention is to provide a fuel supply device for an internal combustion engine, which has improved startability.

[0006]

Therefore, the present invention is based on FIG.
As shown in FIG. 2, an air pump A for pressurizing air, a pressure accumulator B for storing the pressurized air pressurized by the air pump A, and a fuel injection valve for intermittently injecting the pressurized air with fuel are provided. In a fuel supply device for an internal combustion engine, which includes an air-assisted fuel injection valve C that is introduced downstream to atomize the fuel, a startup state detection means D that detects the startup state of the engine.
And if it is detected that the engine is starting,
The supply of the pressurized air from the air pump A to the pressure accumulating container B is stopped and the pressurized air is controlled to be supplied to the air assist fuel injection valve C, while the air pump A is supplied when the engine is not in the starting state. From the pressure accumulating container B and the air assist fuel injection valve C to supply pressurized air.

[0007]

According to the above construction, when it is detected that the engine is in the starting state, the supply control means stops the supply of the pressurized air from the air pump to the pressure accumulating container, and at the same time, the supply of the pressurized air is stopped. The compressed air is controlled so as to be supplied to the air assist fuel injection valve.

[0008]

Embodiments of the present invention will be described below with reference to FIGS. The same components as those of FIG. 5 described in the conventional example are designated by the same reference numerals and the description thereof will be omitted.

In this embodiment, the discharge side pipe 21 of the air pump 2 communicates with the pressure accumulating container 6 for preventing the occurrence of pressure pulsation via the branch pipe 22, and the communication pipe 23.
It communicates with the air gallery 8 via. An electromagnetic opening / closing valve 31 is provided in the branch pipe 22. An electromagnetic regulator 35 is provided in the communication pipe 23 to regulate the pressure supplied to the air gallery 8 to a predetermined pressure.

Here, as shown in FIG. 3, in the air-assisted fuel injection valve 1, the flow rate of the air introduced from the air gallery 8 is adjusted by the needle valve type adjustment valve, and the air-assisted fuel injection is performed. It reaches the mixing portion 1b in the main body of the valve 1, is jetted from a large number of injection holes provided in the fuel passage wall, and is mixed with fuel. Then, while passing through the extension portion 1c, the fuel and the assist air are sufficiently mixed,
Atomization of fuel is achieved.

Further, the air assist fuel injection valve 1, the air pump 2, the electromagnetic on-off valve 31, the electromagnetic regulator.
35 is controlled by the control unit 41 based on various input signals as described later, and the control unit 41
Constitutes the supply control means. Here, the input signal is an ignition on / off signal from the ignition switch 42, an engine speed N signal detected by a crank angle sensor 43 provided in a distributor or the like (not shown), and the ignition switch 42 and the crank. The angle sensor 43 constitutes a starting state detecting means.

Next, the operation of this one will be described with reference to FIG. When the ignition switch 42 is turned on when the engine is started, an ON signal is input from the ignition switch 42 to the control unit 41, and at the same time, an operation signal is output from the control unit 41 to the air pump 2 so that the air pump 2 operates. Start operation.

As a function of the present invention, if the engine speed N detected by the crank angle sensor 43 is lower than the reference speed Nc even when the ON signal is inputted from the ignition switch 42, the control unit 41
Determines that the engine is starting and outputs an ON signal to close the electromagnetic on-off valve 31 provided in the branch pipe 22. Therefore, the pressurized air supplied from the air pump 2 is not supplied to the pressure accumulating container 6, and the discharge side pipe 21 to the communication pipe 23
It is supplied only to the air gallery 8 via. That is, when the engine is started, the entire amount of the air pressurized by the air pump 2 is supplied only to the mixing section 1b of the air assist fuel injection valve 1. Therefore, as shown in FIG. 4, when the engine is started, the air pressure in the air gallery 8 rapidly rises, and sufficient pressurized air is supplied to the air assist fuel injection valve 1 to rapidly exhibit the effect as assist air. Therefore, the startability of the engine is significantly improved.

When the engine is started by a starter motor or the like (not shown) and the engine start is completed, and the engine speed N rises to become higher than the reference speed Nc, the control unit 41 uses an electromagnetic system. An off signal is output to open the on-off valve 31. As a result, the pressurized air supplied from the air pump 2 is also supplied to the air gallery 8 through the communication pipe 23, and at the same time, the discharge side piping
It is supplied to the pressure accumulating container 6 from 21 via a branch pipe 22.

In this state, for example, even when the pressurized air from the air pump 2 needs to have more pressure than the pressurized air at the time of sudden acceleration, the accumulator 6 having a large capacity.
As a result, a sufficient amount of pressurized air is supplied, and it is possible to suppress the pressure drop due to the rapid increase in the flow rate, thereby reducing the pressure pulsation of the pressurized air supplied to the air assist fuel injection valve 1. It becomes possible to do. Further, there is an effect that the stability of the supply of the pressurized air to the air-assisted fuel injection valve 1 is increased and the combustion is further stabilized.

In this embodiment, an electromagnetic regulator 35 is provided in the communication pipe 23, and the set pressure of the electromagnetic regulator 35 is controlled by the control unit 41 so that the pressure supplied to the air gallery 8 is set to a predetermined value. The pressure is regulated.

[0017]

As described above, according to the present invention, in a fuel supply system for an internal combustion engine including an air assist fuel injection valve for atomizing fuel, it is detected that the engine is in a starting state. In this case, the supply of the pressurized air from the air pump to the accumulator is stopped and the pressurized air is supplied only to the air assist fuel injection valve. Sufficient pressurized air will be supplied, improving the engine startability, and increasing the stability of the pressurized air supply to the air-assisted fuel injection valve after engine startup, resulting in stable combustion. There is an effect.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of the present invention.

FIG. 2 is a system configuration diagram showing an overall configuration of a fuel supply device for an internal combustion engine according to an embodiment of the present invention.

FIG. 3 is a vertical sectional view of an air-assisted fuel injection valve according to the above embodiment.

FIG. 4 is a time chart explaining the operation according to the embodiment.

FIG. 5 is a system configuration diagram showing the overall configuration of a conventional fuel supply device.

[Explanation of symbols]

 1 Air-assisted fuel injection valve 1a Fuel injection valve 1b Mixing part 2 Air pump 6 Accumulator container 8 Air gallery 21 Discharge side pipe 22 Branch pipe 31 Electromagnetic on-off valve 41 Control unit (supply control means) 42 Ignition switch (starting state detection means) ) 43 Crank angle sensor (starting state detection means)

Claims (1)

[Claims] 1. An air pump for pressurizing air, a pressure accumulating container for storing the pressurized air pressurized by the air pump, and a fuel injection valve for intermittently injecting the pressurized air into a fuel injection valve. In the fuel supply device for an internal combustion engine, which is provided with an air-assisted fuel injection valve for atomizing the fuel, a starting state detecting means for detecting the starting state of the engine, and it is detected that the engine is in the starting state. In this case, the supply of the pressurized air from the air pump to the pressure accumulator is stopped and the pressurized air is controlled to be supplied to the air assist fuel injection valve. From the pressure accumulator and the air-assisted fuel injection valve to supply pressurized air to the accumulator and the air-assisted fuel injection valve.