JP2003293888A - Fuel injection device and diesel engine comprising the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel injection device which shortens a starting time of the diesel engine, and improves the failure in combustion caused by the shortage of the injection pressure in starting, and also to provide a diesel engine comprising the same. <P>SOLUTION: In a fuel injection device 100 comprises: a fuel injection valve 7 mounted on the diesel engine D/E for injecting the fuel into the diesel engine D/E; a common rail 10 for guiding the fuel to the fuel injection valve 7; a fuel delivering means 6 for delivering the fuel from the fuel tank 1 to the common rail 10; and a control means 11 for controlling the fuel injection valve 7. The fuel delivering means 6 is driven by getting the power from a driving source 14 excluding the diesel engine D/E. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel injection device for injecting fuel into a combustion chamber from a fuel injection valve of a direct injection type diesel engine and a diesel engine equipped with the fuel injection device.

[0002]

2. Description of the Related Art A so-called common rail fuel injection device includes a fuel injection valve for injecting fuel, a common rail for guiding fuel to the fuel injection valve, and a fuel pump (fuel delivery means) for delivering fuel from a fuel tank to the common rail. And a control means for controlling the fuel injection valve as main elements.

In such a fuel injection device, the fuel pump for increasing the fuel pressure in the common rail is driven by the driving force of the diesel engine itself equipped with the fuel injection device. That is, the fuel pump is a machined type that is driven by the rotation of the crankshaft of a diesel engine, and the fuel pump is also driven when the diesel engine starts driving.

[0004]

However, in a diesel engine equipped with such a common rail fuel injection device, the crankshaft must be rotated many times in order to increase the pressure in the common rail to a predetermined value or more, There was a problem that the startup time would be very long. Such a long start-up time leads to an increase in air consumption in a diesel engine started by compressed air, for example. In addition, there is a problem that fuel is injected into the cylinder while the injection pressure at the start of injection is insufficient, resulting in poor combustion.

The present invention has been made in view of the above circumstances, and a fuel injection device capable of shortening the starting time of a diesel engine and improving combustion failure due to insufficient injection pressure at the time of starting, An object is to provide a diesel engine equipped with the fuel injection device.

[0006]

In order to solve the above-mentioned problems, the fuel injection device of the present invention and the diesel engine equipped with the fuel injection device adopt the following means. That is, according to the fuel injection device of the first aspect, a fuel injection valve that is attached to a diesel engine and injects fuel into the diesel engine, a common rail that guides fuel to the fuel injection valve, and a fuel tank from the fuel tank are provided. In a fuel injection device including fuel delivery means for delivering fuel to a common rail and control means for controlling the fuel injection valve, the fuel delivery means is driven by power from a drive source other than the diesel engine. It is characterized by

In this fuel injection device, the power for driving the fuel delivery means is obtained from a drive source other than the diesel engine to which the fuel injection valve is attached. That is, even if the diesel engine is in a stopped state, the fuel delivery means is driven by another drive source, and the pressure in the common rail is raised in advance before the diesel engine is started.

According to the fuel injection device of the second aspect,
In the fuel injection device according to claim 1, a drive source of the fuel delivery means is an air motor.

In this fuel injection device, the fuel delivery means is driven by, for example, an air motor which is driven by the pressurized air which is pre-stored in the air tank.

According to the fuel injection device of the third aspect,
The fuel injection device according to claim 1, wherein the drive source of the fuel delivery means is an electric motor.

In this fuel injection device, the fuel delivery means is driven by an electric motor driven by electric energy.

According to the fuel injection device of the fourth aspect,
A fuel injection valve attached to a diesel engine for injecting fuel into the diesel engine, a common rail for guiding fuel to the fuel injection valve, a fuel delivery means for delivering fuel from a fuel tank to the common rail, and the fuel injection valve In the fuel injection device, the fuel delivery means obtains motive power from the diesel engine and is driven by a drive source other than the diesel engine. And a second fuel delivery means that is driven.

In this fuel injection device, the driving force of the first fuel delivery means is obtained by driving the diesel engine, and the driving force of the second fuel delivery means is obtained by a drive source other than this diesel engine. It will be. That is,
Even when the diesel engine is stopped, the second fuel delivery means is driven by another drive source, and the pressure in the common rail is raised before starting the diesel engine.

According to the fuel injection device of the fifth aspect,
The fuel injection device according to claim 4 is characterized in that a drive source of the second fuel delivery means is an air motor.

In this fuel injection device, the second fuel delivery means is driven by, for example, an air motor which is driven by pressurized air whose pressure is previously accumulated in the air tank.

According to the fuel injection device of the sixth aspect,
The fuel injection device according to claim 4, wherein the drive source of the second fuel delivery means is an electric motor.

In this fuel injection device, the second fuel delivery means is driven by an electric motor driven by electric energy.

According to a seventh aspect of the diesel engine, the fuel injection apparatus according to any one of the first to sixth aspects, an engine body having a cylinder therein, and a piston reciprocating in the cylinder. And a connecting rod that connects the piston and the crankshaft.

In this diesel engine, the pressure in the common rail is raised in the stopped state.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of a fuel injection device according to the present invention will be described below with reference to FIG. FIG. 1 is a schematic configuration diagram of a fuel injection device, a so-called common rail fuel injection device. As shown in FIG. 1, the fuel injection device 100
Is a fuel tank 1, a fuel supply pump 2, a relief valve 3,
Check valve 4, fuel supply pipe 5, fuel pump (fuel delivery means;
(Second fuel delivery means) 6, fuel injection valve 7, communication pipe 8, fuel return pipe 9, common rail 10, control device 11
(Control means), the second communication pipe 12, the check valve 13, and the throttle valve 15 are configured as main elements.
In addition, the code | symbol D / E in the figure has shown the diesel engine.

The relief valve 3 releases pressure when the fuel supply pump 2 which is always operating supplies fuel at a pressure higher than a predetermined pressure, and returns the fuel from the fuel supply pipe 5 to the fuel tank 1. The check valve 4 shuts off the fuel supply pipe 5 when the plunger 6b of the fuel pump 6 moves up (discharging operation). The throttle valve 15 is for adjusting the amount of fuel sucked into the fuel pump 6.

The fuel pump 6 is a pump that sucks and pressurizes the fuel from the fuel tank 1 and sends it to the communication pipe 8 to supply it, and the communication pipe 8 is connected to the common rail 10. Therefore, the fuel discharged from the fuel pump 6 is supplied to the common rail 10. The fuel pump 6 includes a plunger chamber 6a connected to the fuel tank 1 via a fuel supply pipe 5, and a drive source (diesel engine D / E).
A driving source other than the crankshaft 14) and a plunger 6b which reciprocates vertically to pressurize the fuel in the plunger chamber 6a.

Further, the cam C is provided with a profile for lowering the plunger 6b at a constant speed during a certain period of the process of lowering the plunger 6b.
As a result, the suction volume per unit time of the fuel pump 6 during this period is constant.

The fuel injection valve 7 is a device for injecting fuel into a combustion chamber (not shown), and the second communication pipe 12 is a conduit for guiding the fuel in the common rail 10 to the fuel injection valve 7. The fuel return pipe 9 is a pipe for returning fuel from the fuel injection valve 7 to the fuel tank 1.

The control device 11 is a device for controlling each of the fuel injection valves 7, and controls the opening / closing of a solenoid valve provided in the fuel injection valve 7, for example. Throttle valve 1
5, the opening degree is controlled by the control device 11,
The fuel intake amount to the fuel pump 6 is adjusted and the common rail 1
The pressure in 0 is kept constant. The check valve 13 prevents the high-pressure fuel from flowing back from the common rail 10 to the fuel pump 6 side.

With this configuration, the fuel pump 6 is driven regardless of whether the crankshaft of the diesel engine D / E is rotating or not, so that the diesel engine D / E is in a stopped state. Also common rail 10
The internal pressure can be raised to a desired pressure. That is, since the predetermined fuel injection pressure can be obtained at the time of starting the diesel engine D / E, the time required for starting the diesel engine D / E can be shortened and the combustion state in each combustion chamber can be improved. And a good smoke color can be obtained.

Further, since the fuel pump 6 can be an external type, the maintainability of the fuel pump 6 itself can be improved.

Next, another embodiment of the fuel injection device according to the present invention will be described with reference to FIG. In FIG. 2, the same members as those in FIG. 1 are designated by the same reference numerals.

The difference between the embodiment of FIG. 2 and the embodiment of FIG. 1 is that the embodiment of FIG. 2 operates in conjunction with the crankshaft of a diesel engine D / E equipped with this fuel injection device 200. The point is that a driven fuel pump (first fuel delivery means) 16 is provided.

As shown in FIG. 2, the fuel pump 16 branched and connected from the middle of the fuel supply pipe 5 is a pump that sucks and pressurizes the fuel from the fuel tank 1 and sends it to the communicating pipe 18 to supply it. The communication pipe 18 is connected to the common rail 10. Therefore, the fuel discharged from the fuel pump 16 is supplied to the common rail 10. The fuel pump 16 includes a plunger chamber 16a connected to the fuel tank 1 through the fuel supply pipe 5, and a cam C that works with the crankshaft of the diesel engine D / E.
And a plunger 16b that reciprocates vertically to pressurize the fuel in the plunger chamber 16a.

Further, the cam C is provided with a profile for lowering the plunger 16b at a constant speed during a certain period in the process of lowering the plunger 16b. As a result, the suction volume per unit time of the fuel pump 16 in this period is constant.

The check valve 13 prevents the high-pressure fuel from flowing back from the common rail 10 to the fuel pump 16 side.

With this configuration, when the diesel engine D / E is started, the pressure in the common rail 10 is increased by the operation of the fuel pump 6 which is driven regardless of the rotation of the crankshaft of the diesel engine D / E. The pressure in the common rail 10 is increased to a desired pressure by the operation of the fuel pump 16 driven by the rotation of the crankshaft of the diesel engine D / E during the operation of the diesel engine D / E. Will be done. As a result, a predetermined fuel injection pressure can be obtained at the time of starting the diesel engine D / E, so that the time required for starting the diesel engine D / E can be shortened and the combustion state in each combustion chamber can be improved. And a good smoke color can be obtained.

Further, since the fuel pump 6 can be of the external type, the maintainability of the fuel pump 6 itself can be improved, and the existing fuel pump 6 having no such external fuel pump 6 is provided. Diesel engine D / E
In addition, the fuel pump 6 can be retrofitted.

The drive source 14 described above is advantageous if it is an air motor driven by pressurized air accumulated in an air tank, for example. Since the fuel pump 6 is driven by the air motor, the fuel pump 6 can be driven even if the power supply cannot be secured.

The drive source 14 described above is advantageous as long as it is an electric motor driven by electric energy.
Since the fuel pump 6 is driven by the electric motor, the fuel pump 6 can be driven even if pressurized air cannot be secured.

[0037]

The fuel injection device of the present invention and the diesel engine equipped with the fuel injection device have the following effects. According to the fuel injection device of the first aspect, even if the diesel engine is stopped, the fuel delivery means is driven by another drive source, and the pressure in the common rail is increased in advance before the diesel engine is started. As a result, the diesel engine startup time can be shortened, and the combustion state at startup can be improved. In addition, since the fuel pump can be of an external type, the maintainability of the fuel pump itself can be improved.

According to the fuel injection device of the second aspect, since the fuel delivery means is driven by the air motor, it is possible to drive the fuel pump even if the power supply cannot be secured. .

According to the fuel injection device of the third aspect, the fuel delivery means is driven by the electric motor, so that the fuel pump can be driven even if pressurized air cannot be secured. Produce an effect.

According to the fuel injection device of the fourth aspect, the second fuel delivery means is driven by another drive source even when the diesel engine is in a stopped state, and the second fuel delivery means is driven in the common rail before starting the diesel engine. Since the pressure is preliminarily raised, it is possible to shorten the starting time of the diesel engine and to obtain a good combustion state at the time of starting. Further, since the fuel pump can be of an external type, the maintainability of the fuel pump itself can be improved, and it is possible to retrofit an existing diesel engine that does not have such an external fuel pump. There is an effect that it can be attached.

According to the fuel injection device of the fifth aspect, since the second fuel delivery means is driven by the air motor, the fuel pump can be driven even if the power supply cannot be secured. Produce an effect.

According to the fuel injection device of the sixth aspect, since the second fuel delivery means is driven by the electric motor, the fuel pump can be driven even if pressurized air cannot be secured. There is an effect that can be.

According to the diesel engine of claim 7,
Since the pressure in the common rail is raised in the stopped state, it is possible to shorten the starting time of the diesel engine and to improve the combustion state at the start.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing an embodiment of a fuel injection device according to the present invention.

FIG. 2 is a schematic configuration diagram showing another embodiment of the fuel injection device according to the present invention.

[Explanation of symbols]

1 fuel tank 7 Fuel injection valve 6 Fuel pump (fuel delivery means; second fuel delivery means) 10 common rail 11 Control device (control means) 16 Fuel pump (first fuel delivery means) 100 fuel injection device 200 Fuel injector D / E diesel engine

Claims (7)

[Claims] 1. A fuel injection valve mounted on a diesel engine for injecting fuel into the diesel engine, a common rail for guiding fuel to the fuel injection valve, and a fuel delivery means for delivering fuel from a fuel tank to the common rail. And a control unit for controlling the fuel injection valve, wherein the fuel delivery unit is driven by power from a drive source other than the diesel engine. 2. The fuel injection device according to claim 1, wherein the drive source of the fuel delivery means is an air motor. 3. The fuel injection device according to claim 1, wherein the drive source of the fuel delivery means is an electric motor. 4. A fuel injection valve attached to a diesel engine for injecting fuel into the diesel engine, a common rail for guiding fuel to the fuel injection valve, and a fuel delivery means for delivering fuel from a fuel tank to the common rail. And a control means for controlling the fuel injection valve, wherein the fuel delivery means includes a first fuel delivery means driven by power from the diesel engine and a drive other than the diesel engine. And a second fuel delivery means that is driven by power from a power source. 5. The fuel injection device according to claim 4, wherein the drive source of the second fuel delivery means is an air motor. 6. The fuel injection device according to claim 4, wherein the drive source of the second fuel delivery means is an electric motor. 7. The fuel injection device according to claim 1, an engine body having a cylinder therein, a piston reciprocating in the cylinder, and the piston and a crankshaft connected to each other. A diesel engine, comprising: a connecting rod that: