JP2001050118A - Fuel injector incorporating fuel reformer in internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently convert fuel into reformed gas which is then fed into each of engine cylinders upon a start. SOLUTION: Reforming catalyst 15 is packed in a cylindrical heater 13 which is connected to the front end of a fuel injector 11 for each cylinder provided in an intake manifold 1 so as to surround jet spray from a jet hole 11a, and spherical, particulates 16 made of copper, aluminum or the like which is excellent in heat conductivity are packed in the upstream side thereof. Further, a washer member 12 made of a material which is excellent in heat-insulation is provided between the front end of the fuel injector 11 and the cylindrical heater 13. Further, a cylindrical member 10 which is excellent in heat-insulation is provided so as to surround the outer periphery of the cylindrical heater 13. A valve 17 is provided for controlling the supply of reformed gas fed into the engine.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an internal combustion engine capable of reforming fuel (hydrocarbon fuel represented by gasoline or alcohol fuel) into hydrogen, carbon monoxide or the like by the heat of a heater and supplying the reformed fuel to an engine. The present invention relates to a fuel injection valve with a fuel reforming device for an engine.

[0002]

2. Description of the Related Art Conventionally, in an internal combustion engine equipped with a fuel reformer for reforming fuel into hydrogen, carbon monoxide, etc., when starting the catalyst below a temperature at which the catalyst can be reformed, liquid fuel is directly supplied. The catalyst is supplied and operated until the temperature of the catalyst can be reformed. When the temperature of the catalyst rises, the catalyst is switched to the reformed gas.

[0003] However, such an internal combustion engine has a problem that HC is increased and fuel consumption is deteriorated because fuel is directly supplied at the time of starting. As a starting device for such an internal combustion engine, for example, Japanese Utility Model Laid-Open No. 58-356
No. 62 describes a technique.

[0004] In order to perform a stable start even at a low temperature where fuel atomization is poor, a reforming catalyst having a heater built in a part of a collector (collecting portion) of an intake manifold is incorporated. An electromagnetic valve for supplying fuel to the reforming catalyst is provided, and the fuel is converted into reformed gas by the reforming catalyst heated by the heater. Then, after a certain period of time is delayed until the reformed gas is generated, the starter motor is started, and the air sucked from the passage bypassing the throttle valve is guided to the reformed gas generation section, thereby causing the reformed gas to flow through the air. At the same time, the air is distributed to each cylinder from the sub intake passage for each cylinder.

[0005]

However, even if such a conventional starting device is used, part of the collector of the intake manifold is filled with the reforming catalyst, so that the heat of the heater escapes to the intake manifold and the reforming operation is performed. It takes a long time to reach a qualitative temperature, the power consumption of the heater increases, and the battery life is significantly shortened.

Further, although the reformed gas is distributed and supplied to each cylinder together with the air, the fuel passes between the cylinders because the mounting position of the fuel supply solenoid valve is located at one central portion of the collector of the intake manifold. The catalyst loading of the part differs,
A difference occurs in the V ratio (fuel amount / catalyst amount), the composition of the distributed reformed gas is not stabilized, and the engine becomes unstable.

Further, since air is led to the reforming catalyst,
When fuel is supplied from the solenoid valve to the place where the catalyst temperature has been increased by the heater, an oxidation reaction occurs in parallel with the reforming reaction, and the catalyst temperature rises rapidly. Temperature fluctuations also increase.

On the other hand, the reformed gas supplied to the engine has a problem in that the oxidation reaction causes an increase in carbon dioxide, so that the combustion deteriorates and the engine becomes unstable. Then, an object of the present invention is to solve the conventional problem by providing a fuel injection valve with a fuel reformer.

[0009]

Therefore, in the invention according to the first aspect, a cylindrical heater is provided so as to surround the spray from the injection hole following the tip of a fuel injection valve provided for each cylinder. And a fuel injection valve with a fuel reformer for an internal combustion engine, wherein the heater is filled with a reforming catalyst.

[0010] The invention according to claim 2 is characterized in that a substantially spherical good heat conductive material is filled in the heater upstream of the reforming catalyst. The invention according to claim 3 is characterized in that a well-insulated washer member is provided between the tip of the fuel injection valve and the cylindrical heater.

The invention according to claim 4 is characterized in that a well-insulated cylindrical member surrounding the outer periphery of the cylindrical heater is provided. The invention according to claim 5 is characterized in that the fuel injection valve and the cylindrical heater are inserted and integrated into a cylindrical member having good heat insulation.

The invention according to claim 6 is characterized in that a valve for controlling the supply of reformed gas to the engine is provided downstream of the cylindrical heater.

[0013]

According to the first aspect of the present invention, a cylindrical heater is provided in connection with the tip of the fuel injection valve provided for each cylinder, and a reforming catalyst is filled therein. The heater can raise the reforming catalyst to the set temperature in a short time, convert the injected fuel into reformed gas efficiently at the time of starting or the like, and improve the distribution of the reformed gas to each cylinder. In addition, since it can be operated with the reformed gas from the start, there is no fuel wall flow and there is no need to increase the amount at the start,
It is possible to achieve a reduction in the amount of emissions and an improvement in fuel efficiency.

According to the second aspect of the present invention, by filling a substantially spherical good heat conductive material into the upstream side of the reforming catalyst in the heater, heat from the heater is transmitted in a short time and injection fuel is shortened. It evaporates in time, the fuel vapor can be efficiently converted to the reformed gas by the reforming catalyst, and the reformed gas having a stable composition can be supplied to the engine.

According to the third aspect of the present invention, the heat of the heater is transferred to the fuel injection valve side by interposing a good heat insulating washer member between the tip of the fuel injection valve and the cylindrical heater. A reformed gas having a stable composition can be supplied to the engine without escaping.

According to the fourth aspect of the present invention, by providing the cylindrical member having good heat insulation surrounding the outer periphery of the cylindrical heater, the heat of the heater can be externally supplied, that is, the fuel injection valve mounting portion such as the intake manifold. The reformed gas having a stable composition can be supplied to the engine without being released to the engine.

According to the fifth aspect of the present invention, the heat of the heater can be released to the outside by inserting the fuel injection valve and the cylindrical heater into a cylindrical member having good heat insulation and integrating them. In addition to this, attachment to an intake manifold or the like becomes easy.

According to the sixth aspect of the present invention, a valve capable of stopping the supply of reformed gas to the engine is provided downstream of the cylindrical heater, thereby preventing fuel supply in an unreacted state. At the same time, it is possible to prevent an oxidation reaction due to backflow of air from an intake port or the like other than at a predetermined supply time such as at the time of starting.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a system diagram showing a fuel injection valve with a fuel reformer and its control system, and FIG. 2 is an enlarged view of the fuel injector with a fuel reformer in FIG.

A fuel injection valve 3 with a fuel reformer according to the present invention is mounted in a mounting hole 2 provided in a wall of a branch for each cylinder of an intake manifold 1 of an internal combustion engine. The reformed gas can be supplied to the intake port 5 on the head 4 side. 6 is an intake valve,
Reference numeral 7 denotes an ignition plug.

The fuel injection valve 3 with a fuel reforming device has a fuel injection valve 11 built into a cylindrical member 10 having good heat insulation such as ceramic, and a lower part through a washer member 12 having good heat insulation such as ceramic. By incorporating a cylindrical heater (for example, a ceramic heater) 13 on the side, a cylindrical heater 13 is provided so as to be connected to the tip of the fuel injection valve 11 and surround the spray from the injection hole 11a.

The cylindrical heater 13 is filled with a pellet-shaped reforming catalyst 15 after a wire mesh 14 is attached to the opening at the lower end, and the reforming catalyst 1 in the heater 13 is filled.
The upstream side is filled with a substantially spherical good heat conductive material 16 such as copper or aluminum.

The fuel injection valve 3 with the fuel reformer is provided with a valve 17 for controlling the supply of reformed gas to the engine downstream of the cylindrical heater 13. The valve 17 is a rotary valve that is arranged in a hole at the center of an aluminum valve housing 18 provided in connection with the distal end side of the cylindrical member 10, and is rotated by a rotation axis in a direction perpendicular to the paper surface. In the rotation position shown in FIG.
a is opened and closed by rotating 90 degrees from the rotation position shown in FIG.

The rotary shaft of the rotary valve 17 is common to all cylinders, and the rotary valve 17 of all cylinders can be opened and closed by one actuator (not shown). In addition, 21 is a power supply terminal to the electromagnetic coil of the fuel injection valve 11, 22 is a power supply terminal to the heater 13,
Reference numeral 23 denotes a catalyst temperature sensor facing the inside of the reforming catalyst 15, and reference numeral 24 denotes a reformed gas pressure sensor facing the inside of the reforming catalyst 15.

Here, when the ignition switch 32 connected to the battery 31 is turned on, the ignition relay 33 is closed, and at this time, the control circuit E
The heater drive signal is turned on in the CM (engine control module) 34 and the heater 13 is energized. As a result, the reforming catalyst 15 and the good thermal conductive material 16 are heated by the heater 13 and reach a temperature at which the reforming can be performed in a short time (about one second).

When the catalyst temperature detected by the catalyst temperature sensor 23 facing the reforming catalyst 15 reaches a predetermined reformable temperature (for example, 300 ° C.), a fuel pump driving signal and a fuel injection The valve drive signal turns ON,
The fuel pump relay 35 is closed, the fuel pump 36 is driven, and the fuel injection valve 11 is driven.
From 1 fuel is injected.

The injected fuel is converted into a vapor by contact with a substantially spherical good heat conductive material 16 such as copper or aluminum, and is converted by the reforming catalyst 15 into a reformed gas rich in hydrogen, carbon monoxide and the like. .

The reformed gas pressure detected by the reformed gas pressure sensor 24 facing the reforming catalyst 15 reaches a predetermined value, and the catalyst temperature detected by the catalyst temperature sensor 23 can be reformed. If the temperature is maintained above
The valve drive signal is turned on in M34, an actuator (not shown) is driven, and the rotary valve 17 is opened. Thereby, the reformed gas is supplied to the engine via the intake passage.

At this time, at the same time, the starter motor drive signal is turned on in the ECM 34, and the starter relay 37,
38 is closed, the starter motor 39 is driven, and the engine is started.

In this way, by operating with the reformed gas from the start, there is no wall flow of fuel and no increase in the amount at the start is required.
Improved fuel economy can be achieved.

After the start-up or after some warm-up is completed, the supply of the reformed gas from the fuel injection valve 3 with the fuel reformer is stopped, and the reformed gas is supplied from the main reformer. To do.

For example, when the exhaust gas temperature of the engine reaches a certain value, a certain amount of fuel is supplied to a main reformer for reforming by the exhaust heat, and the fuel is reformed and the main fuel is reformed. When the pressure in the reformer rises and reaches a specified value, the gas valve provided on the collector of the intake manifold is opened to start supplying reformed gas to the engine,
Start continuous fuel supply to the main reformer.
At the same time, the fuel injection of the fuel injection valve 11 is stopped, the heater 13 is turned off, the rotary valve 17 is closed,
The supply of the reformed gas from the fuel injection valve 3 with the fuel reformer is stopped, and the operation is switched to the operation by the main reformer.

However, the fuel injection valve 3 with the present fuel reformer
Can be used other than during start-up and during warm-up, especially during transitions (sudden acceleration) when it is difficult to supply the amount of reformed gas required by the engine with only the main reformer. Can be used to supply reformed gas to As a result, stable operation can be performed in all regions.

As described above, the cylindrical heater 13 is provided in connection with the front end of the fuel injection valve 11 provided for each cylinder in the intake manifold 1, and the reforming catalyst 15 is filled in the heater 13. By means of 13, the reforming catalyst 15 can be raised to the set temperature in a short time, the injected fuel can be efficiently converted to the reformed gas, and the distribution of the reformed gas to each cylinder is also improved.

By filling a substantially spherical good heat conducting material 16 in the upstream side of the reforming catalyst 15 in the heater 13, heat from the heater 13 is transmitted in a short time, and the injected fuel evaporates in a short time. The fuel vapor can be efficiently converted into the reformed gas by the reforming catalyst 15, and the reformed gas having a stable composition can be supplied to the engine.

A well-insulated washer member 12 is provided between the tip of the fuel injection valve 11 and the cylindrical heater 13 so as to surround the outer periphery of the cylindrical heater 13. Is provided, the heat of the heater 13 does not escape to the fuel injection valve 11 and the intake manifold 1, and the reformed gas having a stable composition can be supplied to the engine.

A valve 17 for controlling the supply of reformed gas to the engine is provided downstream of the cylindrical heater 13.
By performing necessary control based on the catalyst temperature and the reformed gas pressure, fuel supply in an unreacted state can be prevented, and
An oxidation reaction due to backflow of air from an intake port or the like can be prevented at times other than the predetermined supply time.

[Brief description of the drawings]

FIG. 1 is a system diagram of a fuel injection valve with a fuel reformer and a control system thereof according to an embodiment of the present invention.

FIG. 2 is an enlarged view of a fuel injection valve with a fuel reformer in FIG. 1;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Intake manifold 3 Fuel injection valve with a fuel reforming device 10 Cylindrical member with good heat insulation 11 Fuel injection valve 11a Injection hole 12 Washer member with good heat insulation 13 Cylindrical heater 14 Wire mesh 15 Reforming catalyst 16 Good heat conductive material 17 Rotary Valve 17a Supply Hole 18 Valve Housing 21 Power Supply Terminal to Fuel Injection Valve 22 Power Supply Terminal to Heater 23 Catalyst Temperature Sensor 24 Reformed Gas Pressure Sensor

Claims (6)

[Claims] A cylindrical heater is provided so as to be connected to the tip of a fuel injection valve provided for each cylinder so as to surround a spray from an injection hole, and the heater is filled with a reforming catalyst. A fuel injection valve with a fuel reformer for an internal combustion engine. 2. A fuel injection valve with a fuel reforming device for an internal combustion engine according to claim 1, wherein an upstream side of said reforming catalyst in said heater is filled with a substantially spherical good heat conductive material. 3. The fuel for an internal combustion engine according to claim 1, wherein a well-insulated washer member is provided between a tip portion of the fuel injection valve and the cylindrical heater. Fuel injection valve with reformer. 4. A fuel reformer for an internal combustion engine according to claim 1, wherein a cylindrical member having good heat insulation surrounding the outer periphery of said cylindrical heater is provided. Fuel injection valve with device. 5. The fuel injection valve according to claim 1, wherein the fuel injection valve and the cylindrical heater are inserted into a cylindrical member having good heat insulation and integrated. A fuel injection valve with a fuel reformer for an internal combustion engine according to the above. 6. The valve according to claim 1, wherein a valve for controlling the supply of reformed gas to the engine is provided downstream of the cylindrical heater. A fuel injection valve with a fuel reformer for an internal combustion engine.