JPH0560037A - Combustion characteristic evaluating device for liquid fuel oil and supply of fuel oil thereof - Google Patents

Abstract

PURPOSE:To compare different softs of test samples of fuel oil in predetermined conditions in a short time, and reduce consumption of reference oil and the test samples of fuel oil by disposing fuel oil injectors close to a suction valve of an engine main body for plural fuel oil supply systems respectively. CONSTITUTION:For evaluating combustion characteristics of each fuel oil, an engine main body 2 is rotated as predetermined by an AC dynamometer 1, a fuel oil injection timing and an injector 12 for injecting the fuel oil are determined by a controller 6 based on an output of a crank angle detector 7, and the fuel oil is injected from the selected injector 12 into a suction pipe 17 close to a suction valve so that combustion characteristics are measured. The injector 12 for injecting the fuel is changed at a predetermined cycle, and a pressure action in a combustion chamber at the time is detected by a pressure detector 8 to be taken into a fuel analyzer 21. At least one of plural fuel supply systems 5 is used as a reference fuel oil system, and the measurement of combustion characteristics of the reference oil is interposed among those of respective fuel oil samples.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a combustion characteristic evaluation device for measuring the combustion characteristics of a liquid fuel oil in a spark ignition engine in a laboratory in order to evaluate the combustibility of the liquid fuel oil. TECHNICAL FIELD The present invention relates to a liquid fuel oil combustion characteristic evaluation apparatus having an improved method and a fuel oil supply method thereof.

[0002]

2. Description of the Related Art In order to improve the output of a spark ignition engine, it is important to improve the thermal efficiency by making the heat cycle as close as possible to the Otto cycle based on constant volume combustion by ignition at the compression top dead center.

At present, actual combustion requires a period of about 40 to 60 ° in crank angle, and it is necessary to shorten the combustion period while preventing knocking and NOx generation, that is, to increase the combustion speed. It is desired as a measure to improve the output or thermal efficiency. In order to design fuel oil aiming at improvement of thermal efficiency, it is necessary to understand the relationship between the combustion characteristics of fuel oil and the fuel oil properties. For that purpose, the combustion characteristics of the liquid fuel oil are measured with an internal combustion engine kept under a certain constant operating condition, and such measurement is performed for a plurality of types of liquid fuel oil, and the combustion characteristics of the standard fuel oil are It is also necessary to make comparisons.

[0004]

However, when the combustion characteristics of a plurality of fuel oils are compared and examined using the internal combustion engine, it is necessary to keep the operating conditions of the internal combustion engine constant. It is not easy to keep the conditions constant, and the operating conditions often change when the test fuel oil is changed, so there is a problem in comparative examination of fuel oil.

In order to solve such a problem, there is adopted a method of correcting the operation change by using the standard fuel oil and sandwiching the test of the standard fuel oil between the tests of the respective test fuel oils.
However, in the case of this test method, it is necessary to replace the test fuel oil with the standard fuel oil in the fuel oil supply system from the fuel oil injector to the fuel oil tank for each evaluation operation of the test fuel oil. Therefore, there is also a method of switching the fuel oil in front of the fuel oil supply pump by having multiple fuel oil tanks and fuel oil switching valves, but it is attached to the fuel oil ingenta, the fuel oil supply pipe and the inner wall of the fuel oil pump. There is a problem that it is difficult to replace the used fuel oil, and a large amount of time and a large amount of standard fuel oil and test fuel oil are required. For example, in the conventional combustion characteristic evaluation method, every time a combustion test of one type of test fuel oil or standard fuel oil is performed, the fuel oil supply system is purged, and after the fuel oil is completely replaced, the equivalence ratio is changed. It takes about 20 minutes to stabilize the engine by combining [equivalent ratio = {actual fuel air ratio} / {theoretical fuel air ratio (stoichiometric ratio)}] It takes about 1 minute. In addition, as a method that can measure and evaluate in a short time, like a CFR engine for octane number measurement, it has a special carburetor, multiple fuel oil tanks and a fuel oil switching valve. There is also a method of switching the fuel oil, but when measuring the pressure behavior in the combustion chamber as one method of evaluating combustion characteristics, it is necessary to perform highly accurate equivalence ratio control, and it is difficult to perform highly accurate equivalence ratio control by a carburetor. Therefore, it is not suitable for the above measurement. For these reasons, it is desired to develop a combustion characteristic evaluation technique capable of comparatively examining various test fuel oils in a short time under a constant condition and consuming less standard fuel oil and test fuel oil.

The present invention has been made in view of the circumstances as described above, and various test fuel oils can be comparatively studied in a short time under a constant condition, and the standard fuel oil and the test fuel oil can be compared. An object of the present invention is to provide a combustion characteristic evaluation device that requires less consumption and a fuel oil supply method therefor.

[0007]

To solve this problem, a liquid fuel oil combustion characteristic evaluation apparatus according to the present invention includes a plurality of fuels including a fuel oil injector, a fuel oil supply pipe, a fuel oil pump, and a fuel oil tank. Each of the fuel oil injectors of the oil supply system is arranged near the intake valve of the engine body.

Further, in the fuel oil supply method in the liquid fuel oil combustion characteristic evaluation apparatus of the present invention, at least one fuel oil supply system of the plurality of fuel oil supply systems is used for supplying standard fuel oil, and At least one of the fuel oil supply systems is used for supplying the test fuel oil, and the standard fuel oil and the test fuel oil are alternately supplied.

[0009]

The plurality of fuel oil supply systems handle different test fuel oils, and one fuel oil supply system handles the standard fuel oil.

When the internal combustion engine is rotated by a motor and the internal combustion engine is in a stable state, the test fuel oil is supplied from the fuel oil injector of one fuel oil supply system to the inside of the engine body through the intake system and burned to obtain combustion characteristics. taking measurement. After the measurement of one test fuel oil is completed, the fuel injector of another fuel oil supply system is switched to measure the combustion characteristics of another type of test fuel oil. Further, the fuel oil injector is switched between the combustion characteristics of various test fuel oils to measure the combustion characteristics of the standard fuel oil.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the present invention will be described below with reference to the drawings showing one embodiment.

In FIG. 1, reference numeral 1 is a combustion characteristic evaluation device. The combustion characteristic evaluation device 1 includes an engine body 2. An intake system 3 for supplying a fuel oil / air mixture to the engine body 2, an exhaust system 4 for discharging exhaust gas, a plurality of fuel oil supply systems 5 for supplying fuel oil into the intake system 3, a fuel oil Is provided with a fuel oil injection controller 6 for determining the injection timing of the fuel and for instructing the opening and closing of a fuel injector described later, a crank angle detector 7 for detecting the crank angle, and a pressure detector 8 for detecting the pressure in the combustion chamber. ..

A piston (not shown) in the engine body 2 is driven by an AC dynamometer 11. Each of the plurality of fuel oil supply systems 5 has a fuel oil injector 1.
2, a fuel oil supply pipe 13, a fuel oil pump 14, and a fuel oil tank 15 are provided. The number of the fuel oil supply system 5 is from several to about 10, preferably from 2 to 4.

As shown in FIGS. 2 and 3, the plurality of fuel oil injectors 12 are mounted so that fuel oil can be injected into the intake pipe 17 immediately before the intake valve 16 of the engine body 2. In order to make the injection conditions from the fuel oil injectors 12 the same, it is desirable that the relative positions of the fuel oil injectors 12 relative to the intake valve 16 be equal. Therefore, each fuel oil injector 12 is attached to a laterally movable frame (not shown) so that the fuel oil injector 12 can laterally move with the movement of the frame, and the fuel oil of the fuel oil supply system 5 to be used. Only the injector is brought to a constant fuel oil injection position, and the fuel oil is not ejected from the fuel oil injector deviated from the fuel oil injection position.

Alternatively, each fuel oil injector 12
Is attached to a rotatable manifold 18 so that it can be rotationally displaced as the manifold 18 rotates, so that only the fuel oil injector of the fuel oil supply system 5 to be used comes to a constant fuel oil injection position, The fuel oil is not ejected from the fuel oil injector that is deviated from the fuel oil injection position.

In the combustion characteristic evaluation device thus constructed, the operation for evaluating the combustion characteristic of the fuel oil is as follows.

First, the AC dynamometer 11 is used for the engine body 2
Motor to a constant rotation, then crank angle detector 7
The signal from is taken into the fuel oil injection controller 6, the fuel oil injection timing and the fuel oil injector for injecting the fuel oil are determined, and the signal is sent to the fuel oil injector 12. Only the selected fuel oil injector 12 injects fuel oil into the intake pipe 17, and the injected fuel oil becomes a mixture with air, is introduced into the engine body 2 through the intake valve 16, burns, and measures combustion characteristics. Is done.

Fixed cycle, preferably 10 cycles
The fuel oil injector that injects the fuel oil is switched every 1000 cycles, and the pressure behavior in the combustion chamber at that time is detected by the pressure detector 8 and taken into the combustion analysis device 21 for measurement. As the combustion analysis device 21, a commercially available one can be used, and as such a commercially available combustion analysis device, “C
B-467 "(manufactured by Ono Sokki Co., Ltd.) can be used.

Of the plurality of fuel oil supply systems 5, at least one fuel oil supply system is used as standard fuel oil to supply the standard fuel oil to the engine body 2, and the remaining fuel oil supply system is used as the test fuel oil. If the test fuel oil is used to supply the test fuel oil to the engine body 2, the combustion characteristic measurement of the standard fuel oil can be sandwiched between the combustion characteristic measurement of each test fuel oil.

As the fuel oil injector, various kinds of fuel oil can be used as long as they can atomize the fuel oil in an arbitrary amount by the fuel oil injection controller and inject it at an arbitrary time. The fuel oil injector may be arranged anywhere in the intake system, but is preferably arranged near the intake valve. Further, it is preferable for comparison of each fuel oil that the injector is arranged so that the injection angle is constant with respect to the valve.
In order to keep the injection angle constant, the fuel oil injector may be attached to a frame that can move horizontally and the injector used may move horizontally so that it is always in the same place, or the fuel oil injector can be rotated. It may be fixed to the manifold and rotated so that the injector to be used is always at the same place, or it may be fixed to the fixed manifold at two positions at the same angle with respect to the valve.

[0021]

According to the combustion characteristic evaluation apparatus of the present invention, 1
Since multiple fuel oil supply systems are provided for each engine body, the test fuel oil can be switched by simply switching the operating injector, not replacing the test fuel oil in the fuel oil supply system. There is no need for purging in the fuel oil supply system to completely replace the fuel oil before replacement attached to the inner wall of the oil supply system with the fuel oil after replacement, and since the fuel oil does not mix, Fuel oil can be replaced easily, quickly and reliably. Moreover, because the fuel oil can be changed in a short time, there are no changes in operating conditions due to changes in atmospheric pressure, temperature, humidity, cooling water temperature, lubricating oil temperature, etc. Since the combustion characteristics of fuel oil can be measured, there is no need to make a relative comparison with standard fuel oil.

However, it is possible to more accurately grasp the combustion characteristics of the test fuel oil by making a relative comparison with the standard fuel oil. Even in that case, one of the plurality of fuel oil supply systems can be used as the standard fuel. If it is used as a system for supplying oil, switching between standard fuel oil and test fuel oil can be performed easily, quickly and reliably.

Thus, according to the combustion characteristic evaluation apparatus of the present invention, the fuel oil can be easily, quickly and surely replaced without replacing the standard fuel oil in the fuel oil supply system for each evaluation of the test fuel oil, and the test is performed. Allows relative comparison of combustion characteristics of fuel oil and other test fuel oils.

[Brief description of drawings]

FIG. 1 is a structural explanatory view of a combustion characteristic evaluation device of the present invention.

FIG. 2 is a side view showing the arrangement of fuel oil injectors.

FIG. 3 is a front view showing the arrangement of fuel oil injectors.

[Explanation of symbols]

 1 Combustion Characteristic Evaluation Device 2 Engine Body 3 Intake System 4 Exhaust System 5 Fuel Oil Supply System 6 Fuel Oil Injection Controller 7 Crank Angle Detector 8 Pressure Detector 11 AC Dynamometer 12 Fuel Oil Injector 13 Fuel Oil Supply Pipe 14 Fuel oil pump 15 Fuel oil tank 16 Intake valve 17 Intake pipe 18 Manifold 21 Combustion analysis device

Claims (2)

[Claims] 1. The fuel oil injector of each of a plurality of fuel oil supply systems including a fuel oil injector, a fuel oil supply pipe, a fuel oil pump, and a fuel oil tank is arranged near an intake valve of an engine body. An apparatus for evaluating combustion characteristics of liquid fuel oil, characterized by: 2. At least one of the plurality of fuel oil supply systems is used for supplying standard fuel oil, and at least one other fuel oil supply system is used for supplying test fuel oil, and standard fuel oil is supplied. A fuel oil supply method in a liquid fuel oil combustion characteristic evaluation apparatus, characterized in that fuel oil and test fuel oil are supplied alternately.