JPH0117645Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a fuel injection system that mixes two types of fuel and injects and supplies the mixture to a compression ignition engine.

In recent years, air pollution caused by exhaust from automobile engines has become a social problem, and because petroleum resources are limited, various studies have been carried out for low-pollution combustion and low fuel consumption.

Also, for compression ignition engines, methods have been proposed in which alcohol is mixed with light oil and burned in order to achieve low-pollution combustion and low fuel consumption.

However, in order to maintain good combustion efficiency and proper operation in this type of engine, the ratio of alcohol to diesel oil must be changed depending on the operating conditions. In consideration of this, it has been difficult to increase the alcohol ratio as much as possible while changing the mixing ratio depending on the operating conditions of the engine to ensure proper operation of the engine.

The purpose of this invention was to change the mixing ratio of two types of fuel according to the operating conditions of a compression ignition engine, to ensure proper operation of the engine, and to reduce the consumption of petroleum-based fuels as a measure against the depletion of petroleum resources. The objective is to provide a fuel injection system that reduces fuel consumption.

To address these issues, the fuel injection system of this invention has a main fuel injection pump, an auxiliary fuel injection pump, and a main fuel injection nozzle connected to the delivery valve of the main fuel injection pump via a main fuel injection pipe. ,
an auxiliary fuel injection nozzle connected to a delivery valve of the auxiliary fuel injection pump via an auxiliary fuel injection pipe;
a main fuel control actuator that drives the control rack of its main fuel injection pump; an auxiliary fuel control actuator that drives the control rack of its auxiliary fuel injection pump; and, depending on engine speed, the main and auxiliary fuel controls. The structure includes a control unit that controls each output current to the actuator.

Hereinafter, preferred specific examples of the fuel injection system according to this invention will be described with reference to the drawings.

The figure shows a 6-cylinder compression ignition engine 25 for a truck.
10 schematically shows a specific example 10 of the fuel injection system of this invention applied to.

This fuel injection system 10 mixes auxiliary fuel alcohol with the main fuel light oil according to the rotation speed of the compression ignition engine 25, and
The main fuel injection pump 11 is configured to inject the mixed fuel into each of the cylinder chambers of the engine 25, and is equipped with six pot injection pumps corresponding to each cylinder of the engine 25. Auxiliary fuel injection pump 12 includes six pot injection pumps corresponding to each cylinder of engine 25
, six main fuel injection nozzles 13 arranged at the cylinder head of the engine 25 so as to inject fuel sent from the main fuel injection pump 11 into each cylinder, and also the auxiliary fuel injection pump. six auxiliary fuel injection nozzles 14 arranged in the cylinder heads to inject fuel delivered from the cylinders 12 into each of the cylinders;
a main fuel feed pump 19 that supplies main fuel to its main fuel injection pump 11; an auxiliary fuel feed pump 20 that supplies auxiliary fuel to its auxiliary fuel injection pump 12; It includes a fuel control actuator 17, an auxiliary fuel control actuator 18 for its auxiliary fuel injection pump 12, and a control unit for the main and auxiliary fuel control actuators 17,18.

The main and auxiliary fuel injection pumps 11, 12 each consist of six injection pumps configured in a row, and, like existing injection pumps, the lead injection pumps are controlled in response to movement of a control rack (not shown). A plunger (not shown) is rotated to change the relative position of the pump housing feed port and its lead, so that the effective stroke of the plunger is changed and the respective delivery valve (not shown).

The main and auxiliary fuel injection nozzles 13 and 14 are arranged in pairs at the cylinder head of the engine 25 to respectively correspond to the six cylinders of the engine 25, and each have six main and auxiliary fuel injection nozzles. It is connected via injection pipes 15, 16 to the delivery valves of its main and auxiliary fuel injection pumps 11, 12, respectively.

Main and auxiliary fuel feed pumps 19, 20
is the main fuel tank storing diesel oil (not shown)
and the fuel suction port 2 of its main fuel injection pump 11
6, and an auxiliary fuel pipe 29 that connects an auxiliary fuel tank (not shown) storing alcohol with the fuel suction port 27 of the auxiliary fuel injection pump 12, Moreover, those feed pumps 19,
20 is driven by its engine 25 and injects diesel oil and alcohol into its main and auxiliary fuel injection pumps 1.
1 and 12, respectively.

Main and auxiliary fuel control actuator 17,1
8 is the main and auxiliary fuel injection pump 1 mentioned above;
The control racks 1 and 12 are configured to be electrically driven.

That is, those actuators 17, 18
has an electromagnetic coil (not shown), one end of which is reciprocally disposed within the coil, and the other end of which controls the main and auxiliary fuel injection pumps 11, 12 via a control arm (not shown).・They each consist of a movable iron core (not shown) connected to the rack end.

Of course, the actuators 17, 18 are controlled by the main and auxiliary fuel injection pumps 11, 18 by signals from the control unit 21, which will be described later.
Their form can be arbitrary as long as they drive each of the 12 control racks,
For example, it is also possible to use as the actuators 17, 18 a servo motor, a pulse motor, or a combination of a hydraulic or pneumatic cylinder as the operating system and a solenoid valve as the control system.

The control unit 21 has a rotation speed sensor 22 of its engine 25 and a load sensor 2 of the main and auxiliary fuel injection pumps 11, 12.
According to the signals from 3 and 24, the output currents to the above-mentioned main and auxiliary fuel control actuators 17 and 18 are respectively controlled according to a preset alcohol mixing ratio pattern for light oil (not shown), and the light oil is This device changes the mixing ratio of alcohol and alcohol, and consists of an input and output circuit, a memory circuit, an arithmetic circuit, a control circuit, and a power supply circuit.

Of course, these load sensors 23 and 24 are connected to the loads of the main and auxiliary fuel injection pumps 11 and 12,
That is, the amounts of light oil and alcohol sent from the injection pumps 11 and 12 to the main and auxiliary fuel injection nozzles 13 and 14 are detected, respectively, and feed back signals are sent to the control unit 21, respectively. 21 constantly appropriately controls the amount of light oil and alcohol supplied based on these signals and the signal from the rotation speed sensor 22 of the engine 25, and based on the alcohol mixing ratio pattern.

Next, to describe the operation of the fuel injection system 10 configured as described above, when the engine 25 is operating, the main and auxiliary fuel injection pumps 11, 12
The respective camshafts of are rotated by the engine 25, and the main and auxiliary fuel feed pumps 19, 20 are each driven by the engine 25, so that the feed pumps 1
9, 20 are compressed in these injection pumps 11, 12, respectively, and the gas oil and alcohol so compressed are further supplied to the main and auxiliary fuel injection nozzles 13, 14, respectively. engine 25 from the nozzle of
is injected into the cylinder chamber, where it mixes and burns.

The control unit 21 then receives the rotational speed of its engine 25 from the sensors 22, 23, 24 and the main and auxiliary fuel injection pumps 11,
12, the main and auxiliary fuel control actuators 17, 18 are controlled based on a pre-stored setting pattern of the alcohol mixing ratio with respect to light oil, and the injection pumps 11,
Since each of the control racks 12 is driven, the optimal mixture of fuel is injected into the cylinder chamber of the engine 25 at all times.

Such a mixed fuel injection operation is sequentially performed in each of the six injection pumps. In this way, the optimal mixture of fuel is injected into each of the six cylinders of the engine 25, so that the engine 25 generates a predetermined output, reduces the consumption of light oil, and reduces the amount of fuel in the exhaust gas. Reduces harmful ingredients and improves smoke and knock.

Also, if you compare it with the conventional injection pump that mixes diesel oil and alcohol and injects it,
The above-described fuel injection system 10 includes independent supply and injection systems for main and auxiliary fuel, which fuels are injected into the cylinders of its engine 25 under the control of a control unit 21, and Moreover, since each of the escape fuels from the main and auxiliary fuel injection pumps 11, 12 is returned to separate fuel reservoirs, the mixture ratio of the injected fuel is varied depending on the escape fuel. The fuel mixture ratio is always adjusted appropriately according to the operating conditions of the engine 25 without being changed.

According to this invention, it consists of main and auxiliary fuel injection pumps, main and auxiliary fuel injection nozzles for the injection pumps, main and auxiliary fuel control actuators for driving the control racks of the injection pumps, and a control unit. The control unit is configured to control these actuators based on a preset two-type fuel mixture ratio pattern depending on the engine speed, so it can control the two types of fuel mixture according to the engine operating conditions. The fuel mixture ratio can be changed,
Proper operation of the engine is ensured, and
The consumption of petroleum-based fuels is effectively reduced, countermeasures are taken to deplete petroleum resources, and low-pollution combustion becomes possible, harmful components in exhaust gas are reduced, and smoke and nozzle are improved, making it extremely practical. become.

[Brief explanation of the drawing]

The figure is a schematic diagram showing a specific example of the fuel injection system of this invention applied to a compression ignition engine for a truck. 10...Fuel injection system, 11...Main fuel injection pump, 12...Auxiliary fuel injection pump, 13...
...Main fuel injection nozzle, 14...Auxiliary fuel injection nozzle, 15...Main fuel injection pipe, 16...Auxiliary fuel injection pipe, 17...Main fuel control actuator, 18
... Auxiliary fuel control actuator, 21 ... Control unit, 22 ... Engine rotation speed sensor, 23, 24 ... Load sensor, 25 ... Engine.

Claims (1)

[Scope of claim for utility model registration] A main fuel injection pump, an auxiliary fuel injection pump, a main fuel injection nozzle connected to the delivery valve of the main fuel injection pump via a main fuel injection pipe, and its auxiliary fuel injection pump. An auxiliary fuel injection nozzle connected to a delivery valve of the fuel injection pump via an auxiliary fuel injection pipe, a main fuel control actuator that drives a control rack of the main fuel injection pump, and a control rack of the auxiliary fuel injection pump. A fuel injection system comprising: an auxiliary fuel control actuator for driving the rack; and a control unit for controlling the respective output currents to the main and auxiliary fuel control actuators depending on engine speed.