JP2016017403A - Fuel supply system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fuel supply system for supplying fuel to an internal combustion engine 2 by a port injection valve 3, capable of taking measures to be able to provide a resonator 15 in a manifold 14.SOLUTION: In a fuel supply system 1, an open passage 6 is branched off from a main supply passage 5 to lead into a fuel tank 19, and an open valve 7 opens or closes the open passage 6. With this configuration, the open valve 7 is opened to open the open passage 6 while an internal combustion engine 2 is stopped, thereby making it possible to reduce a pressure of fuel remaining in the main supply passage 5 or a port injection valve 3 to be equal to an internal pressure of the fuel tank 19. Owing to this, it is possible to suppress leakage of the fuel from the port injection valve 3 and prevent backfire at a time of starting the internal combustion engine 2. It is, therefore, possible to avoid a situation in which a backfire-caused pressure reaches a resonator 15.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a fuel supply device that supplies fuel to an internal combustion engine.

  2. Description of the Related Art Conventionally, in a fuel supply apparatus, a port injection type that includes a port injection valve that injects fuel into an intake port to an internal combustion engine and supplies fuel to the intake port is well known. Also, a combination type that includes a port injection valve and an in-cylinder injection valve that injects fuel into a cylinder of an internal combustion engine and can supply fuel directly into the cylinder is known (for example, see Patent Document 1). .

  In an intake system of an internal combustion engine, a torque-up resonator is provided in an intake manifold (hereinafter abbreviated as a manifold) in order to increase the charging efficiency of intake air (hereinafter abbreviated as intake air) into the internal combustion engine. (For example, refer to Patent Document 2). Here, the torque-up resonator is a device that forms a resonance space that resonates with intake pulsation inside or outside the manifold to increase intake charging efficiency by Helmholtz's resonance principle, and is also expected as a measure to reduce intake noise. (Hereinafter, the torque-up resonator is abbreviated as a resonator).

By the way, in the fuel supply device adopting the port injection type or the combination type, for example, during a long-term internal combustion engine stop for several hours, the fuel leaked from the nozzle hole of the port injection valve forms an air-fuel mixture in the intake port, Backfire may occur due to ignition at the next start of the internal combustion engine. For this reason, the manifold is provided so as to withstand the pressure of the backfire.
However, when a resonator is provided in a resin-made manifold, the resonance space is provided as the following space, and thus the resistance of the resonator to the backfire is regarded as a problem.

That is, the resonance space is provided as a space that is airtightly partitioned inside the manifold or an external space that communicates with the inside of the manifold through a narrow communication path. For this reason, when a manifold or a resonator is provided using resin as a raw material, the resonator must be provided by welding of the resin, and there is a limit to improving the strength of the resonator. Furthermore, in a narrowly divided space such as a resonance space, a situation in which the pressure of the backfire exceeds 10 atm is assumed, and it is difficult to provide a resonator with a strength that can withstand such a high pressure.
As described above, when the fuel is supplied by the port injection type or the combined type fuel supply device, it is necessary to take some measures to provide the resonator in the manifold.

JP 2005-042620 A JP 2007-270687 A

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a resonator in a manifold even when fuel is supplied to an internal combustion engine by a port injection type or combined type fuel supply device. Measures are taken so that

  The fuel supply device of the first invention of the present application includes the following port injection valve, main supply path, open path, and open valve. First, the port injection valve injects fuel into the intake port to the internal combustion engine, and the main supply path is provided with a pump that sucks fuel from the fuel tank and pressurizes and discharges the fuel from the fuel tank. Direct fuel to the valve. The open path is branched from the main supply path and communicates with the fuel tank, and the open valve opens and closes the open path.

As a result, the pressure of the fuel remaining in the main supply passage and the port injection valve can be reduced to be equal to the pressure in the fuel tank by opening the release valve and opening the release passage while the internal combustion engine is stopped. . For this reason, it is possible to suppress fuel leakage from the port injection valve and to prevent backfire when starting the internal combustion engine.
Therefore, even when fuel is supplied to the internal combustion engine by the port injection type or combined type fuel supply device, the resonator can be provided in the manifold.

  A fuel supply device according to a second aspect of the invention that is dependent on the first aspect of the present application includes the following in-cylinder injection valve, in-cylinder inner supply path, and main on-off valve. First, the in-cylinder injection valve injects fuel into the cylinder of the internal combustion engine, and the in-cylinder supply path branches from the upstream side of the branch position of the open path in the main supply path to the in-cylinder injection valve. Guide the fuel. The main on-off valve is provided between the branch position of the open path and the branch position of the cylinder inner supply path in the main supply path, and opens and closes the main supply path.

  As a result, in the combined fuel supply device, when the internal combustion engine is stopped, the main on-off valve is closed and the open valve is opened, so that the pressure of the fuel remaining in the port injection valve is changed to the pressure in the fuel tank. The pressure of the fuel remaining in the in-cylinder injection valve can be maintained at a high pressure while keeping it even. For this reason, by performing the fuel injection at the time of starting the internal combustion engine by the in-cylinder injection valve, the internal combustion engine can be started smoothly and the generation of PM at the time of starting the internal combustion engine can be suppressed.

According to a third invention subordinate to the second invention of the present application, the in-cylinder injection valve is a porous type that injects fuel into the cylinder from a plurality of injection holes.
Thereby, generation | occurrence | production of PM at the time of internal combustion engine start-up can further be suppressed.

A fuel supply device according to a fourth aspect of the present invention, which is dependent on the second and third aspects of the present application, includes control means for controlling a port injection valve, an open valve, an in-cylinder injection valve, and a main on-off valve. The control means closes the main open / close valve and opens the open valve while the internal combustion engine is stopped, and opens the main open / close valve after the start of the internal combustion engine. After that.
Thereby, during operation of the internal combustion engine, it is possible to prevent the fuel from returning to the fuel tank through the open path, and to reliably guide the fuel to the port injection valve.

It is a block diagram of a fuel supply apparatus. It is explanatory drawing which shows switching of single injection of a port injection valve, both injection of a port injection valve and a cylinder injection valve, and single injection of a cylinder injection valve. It is a time chart which shows operation | movement of the fuel supply apparatus in the start and stop of an internal combustion engine.

  The fuel supply device of the embodiment will be described based on the following examples. In addition, an Example discloses a specific example, and it cannot be overemphasized that this invention is not limited to an Example.

[Configuration of Example]
The structure of the fuel supply apparatus 1 of an Example is demonstrated using drawing.
The fuel supply device 1 is a device that supplies fuel to the internal combustion engine 2 and includes a port injection valve 3, an in-cylinder injection valve 4, a main supply path 5, an open path 6, an open valve 7, and an in-cylinder inner supply path that will be described below. 8. A main opening / closing valve 9 and a control means 10 are provided (see FIG. 1).
The port injection valve 3 is mounted on the intake port 12 to the internal combustion engine 2 to inject fuel into the intake port 12, and the in-cylinder injection valve 4 is mounted on the cylinder head of the internal combustion engine 2 to inject fuel into the cylinder 13. Spray.

Both the port injection valve 3 and the in-cylinder injection valve 4 are an electromagnetic actuator that uses a nozzle for injecting fuel and a magnetic force generated by energizing the coil as a driving force for opening the nozzle. Have In both cases, fuel injection is started or stopped by energization control of the actuator.
As described above, the fuel supply device 1 is a combined type that can supply fuel to the intake port 12 and can also supply fuel directly into the cylinder 13, and supplies gasoline as fuel to the internal combustion engine 2. To do.

Here, regarding the mode of fuel injection, the proper use of the single injection of the port injection valve 3, the single injection of the in-cylinder injection valve 4, and the both injections of the port injection valve 3 and the in-cylinder injection valve 4 is, for example, as shown in FIG. As shown in FIG. 2, the speed is determined according to the rotational speed and load of the internal combustion engine 2 (for example, the intake amount per rotation of the internal combustion engine 2). For example, when the load increases when the internal combustion engine 2 is operated with the rotation speed kept constant, the fuel injection mode is sequentially the single injection of the port injection valve 3 → the port injection valve 3 and the in-cylinder injection valve. 4 and the single injection of the in-cylinder injection valve 4 are switched.
The in-cylinder injection valve 4 is a porous type that injects fuel into the cylinder 13 from a plurality of injection holes.

  Further, in the intake system of the internal combustion engine 2, a resonator 15 is provided in the manifold 14 in order to increase the charging efficiency of intake air into the internal combustion engine 2. The manifold 14 is made of resin and is fastened to the cylinder head, and the resonator 15 forms a resonance space 16 that resonates with intake pulsation, and enhances the intake charging efficiency by the Helmholtz resonance principle.

  In addition, the resonance space 16 is formed, for example, as a space that is hermetically partitioned in the surge tank 17 and is provided by vibration welding of resin. The resonator 15 can also reduce intake noise by resonating with intake pulsation. The resonance space 16 can also be provided as a space outside the manifold 14. In this case, the resonance space 16 communicates with, for example, the surge tank 17 through a narrow communication path.

  The main supply path 5 is provided with an electric pump 20 that sucks fuel from the fuel tank 19 and pressurizes and discharges the fuel, and guides the fuel from the fuel tank 19 to the port injection valve 3. Here, the fuel tank 19 is opened to an atmospheric pressure atmosphere via a canister (not shown). The electric pump 20 has a well-known structure that is energized and controlled by a command from the control means 10, and sucks and discharges fuel from the fuel tank 19. The fuel tank 19 incorporates a regulator 21 that regulates the pressure of the fuel discharged from the electric pump 20, and is provided downstream of the electric pump 20 in the main supply path 5.

The open path 6 branches from the main supply path 5 and communicates with the fuel tank 19, and the open valve 7 opens and closes the main supply path 5 with respect to the fuel tank 19 by opening and closing the open path 6. .
The open valve 7 has an electromagnetic actuator that uses a magnetic force generated by energizing the coil as a driving force for opening the valve, for example, and opens and closes the open path 6 by controlling energization of the actuator. .

  The cylinder inner supply path 8 branches from the upstream side of the branch position A of the open path 6 in the main supply path 5 and guides the fuel to the cylinder injection valve 4. The cylinder inner supply path 8 is provided with a mechanical pump 22 driven by the internal combustion engine 2. The mechanical pump 22 discharges the fuel discharged from the electric pump 20 at a higher pressure and discharges the fuel from the cylinder injection valve 4. To supply.

The main on-off valve 9 is provided between the branch position A of the open path 6 and the branch position B of the cylinder inner supply path 8 in the main supply path 5 and opens and closes the main supply path 5.
The main on-off valve 9 has, for example, an electromagnetic actuator that uses a magnetic force generated by energizing the coil as a driving force for opening the valve, and the main supply path 5 is controlled by energizing control of the actuator. Open and close.

  The control means 10 is, for example, an electronic control unit (ECU: hereinafter referred to as the ECU 10) that controls the operation of the internal combustion engine 2 mounted on a vehicle. The ECU 10 also has a CPU having a control function and an arithmetic function, a storage device such as a ROM and a RAM, an input device that receives input of signals detected by various sensors, and a signal for controlling energization of various devices. It is a known structure having an output device for outputting. That is, the ECU 10 performs control arithmetic processing using signals detected by various sensors, and based on the results, the port injection valve 3, the in-cylinder injection valve 4, the release valve 7, the main on-off valve 9, and the electric pump 20 Etc. are energized and controlled.

The ECU 10 has a stop mode that is executed when the internal combustion engine 2 is stopped and a start mode that is executed when the internal combustion engine 2 is started.
First, in the stop mode, as shown at time te in FIG. 3, when the ignition switch is turned off, the main on-off valve 9 is closed and the open valve 7 is opened. That is, by executing the stop mode, the ECU 10 closes the main opening / closing valve 9 and opens the opening valve 7 while the internal combustion engine 2 is stopped.

  Further, as shown at time ts in FIG. 3, the start mode is such that the open valve 7 is closed when the ignition switch is turned on, the internal combustion engine 2 is started by the single injection of the in-cylinder injection valve 4, and then the main on-off valve 9 is opened. That is, the ECU 10 opens the main opening / closing valve 9 after closing the opening valve 7 by executing the start mode.

[Effects of Example 1]
The fuel supply device 1 according to the first embodiment includes the following main supply path 5, open path 6, and open valve 7. First, the main supply path 5 is provided with an electric pump 20 that sucks fuel from the fuel tank 19 and pressurizes and discharges the fuel, and guides the fuel from the fuel tank 19 to the port injection valve 3. The open path 6 branches from the main supply path 5 and communicates with the fuel tank 19, and the open valve 7 opens and closes the open path 6.

Thus, the pressure of the fuel remaining in the main supply path 5 and the port injection valve 3 is made equal to the pressure in the fuel tank 19 by opening the release valve 7 and opening the release path 6 while the internal combustion engine 2 is stopped. Can be lowered. For this reason, leakage of fuel from the port injection valve 3 can be suppressed, and backfire when starting the internal combustion engine 2 can be prevented.
Therefore, it is possible to avoid a situation in which the pressure due to the backfire is applied to the resonator 15 provided in the manifold 14.

  The fuel supply device 1 also includes the following cylinder inner supply path 8 and a main on-off valve 9. First, the cylinder inner supply path 8 branches from the upstream side of the branch position of the open path 6 in the main supply path 5 to guide the fuel to the cylinder injection valve 4. The main on-off valve 9 is provided between the branch position A of the open path 6 and the branch position B of the cylinder inner supply path 8 in the main supply path 5 to open and close the main supply path 5.

Thus, while the internal combustion engine 2 is stopped, the main on-off valve 9 is closed and the release valve 7 is opened, so that the fuel pressure remaining in the port injection valve 3 is kept equal to the pressure in the fuel tank 19. However, the pressure of the fuel remaining in the in-cylinder injection valve 4 can be kept high. For this reason, by performing the fuel injection at the start of the internal combustion engine 2 by the in-cylinder injection valve 4, the internal combustion engine 2 can be started smoothly and the generation of PM at the start of the internal combustion engine 2 is suppressed. be able to.
The in-cylinder injection valve 4 is a porous type that injects fuel into the cylinder 13 from a plurality of injection holes, and therefore can further suppress the generation of PM when the internal combustion engine 2 is started.

Further, the ECU 10 closes the main opening / closing valve 9 and opens the opening valve 7 while the internal combustion engine 2 is stopped, and opens the opening of the main opening / closing valve 9 after starting the internal combustion engine 2. After the valve 7 is closed.
Thereby, during operation of the internal combustion engine 2, fuel can be prevented from returning to the fuel tank 19 through the open path 6, and the fuel can be reliably guided to the port injection valve 3.

[Modification]
The mode of the fuel supply device 1 is not limited to the embodiment, and various modifications can be considered. For example, the fuel supply device 1 of the embodiment is a combined type that includes both the port injection valve 3 and the in-cylinder injection valve 4, but the open path 6 is connected to the port injection type fuel supply device 1 that includes only the port injection valve 3. Alternatively, an open valve 7 may be provided.

Further, according to the fuel supply device 1 of the embodiment, the opening valve 7 is closed when the ignition switch is turned on. However, the closing of the opening valve 7 may be preceded by the opening of the main on-off valve 9, There is no particular limitation as long as the injection by the first port injection valve 3 is executed after the start of the internal combustion engine 2.
When the fuel supply device 1 is a port injection type, it is preferable to close the open valve 7 when the ignition switch is turned on from the viewpoint of avoiding the return of fuel through the open path 6. Further, when the fuel supply device 1 is a port injection type, the main on-off valve 9 may not be provided.

DESCRIPTION OF SYMBOLS 1 Fuel supply apparatus 2 Internal combustion engine 3 Port injection valve 5 Main supply path 6 Open path 7 Open valve 12 Intake port 19 Fuel tank 20 Pump

Claims (5)

A port injection valve (3) for injecting fuel into the intake port (12) to the internal combustion engine (2);
A pump (20) for sucking fuel from the fuel tank (19) and pressurizing and discharging the fuel (19); a main supply path (5) for guiding the fuel from the fuel tank (19) to the port injection valve (3);
An open path (6) branched from the main supply path (5) and leading into the fuel tank (19);
A fuel supply device (1) comprising an open valve (7) for opening and closing the open passage (6). The fuel supply device (1) according to claim 1,
An in-cylinder injection valve (4) for injecting fuel into a cylinder (13) of the internal combustion engine (2);
A cylinder inner supply path (8) that branches from the upstream side of the branch position of the open path (6) in the main supply path (5) and guides fuel to the cylinder injection valve (4);
The main supply path (5) is provided between the branch position (A) of the open path (6) and the branch position (B) of the cylinder inner supply path (8), and the main supply path (5) A fuel supply device (1) comprising a main on-off valve (9) that opens and closes. The fuel supply device (1) according to claim 2,
The in-cylinder injection valve (4) is a porous type that injects fuel from a plurality of injection holes into the cylinder (13). The fuel supply device (1) according to claim 2 or claim 3,
Control means (10) for controlling the port injection valve (3), the release valve (7), the in-cylinder injection valve (4), and the main on-off valve (9),
This control means (10)
While the internal combustion engine (2) is stopped, the main on-off valve (9) is closed and the open valve (7) is opened,
The fuel supply device (1) characterized in that after the start of the internal combustion engine (2), the main on-off valve (9) is opened after the open valve (7) is closed. In the fuel supply device (1) according to any one of claims 1 to 4,
The intake manifold (14) fastened to the internal combustion engine (2) is made of resin.
The intake manifold (14) is provided with a torque up resonator (15) that resonates with the pulsation of the intake air sucked into the internal combustion engine (2).

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