Glow Plug and Combustion Control

Abstract

Regarding reducing the cooling loss of combustion at low load in a four-stroke direct injection engine with a compression ratio from 5 to 20, achieve the highest level with the current available technology. 【Solution means】 Use five elements including a piston with a minimized squash area, a variable swirl intake port, a single-port fuel injector, a glow plug with a recess at the tip, and an arbitrary compression ratio to form combustion above the recess under a weak swirl flow and a weak squash flow at low load, without contacting the combustion chamber wall. Aim for fewer failures while having an effect essentially greater than that of a variable cylinder system.

Description

Technical Field

[0001] The present invention relates to glow plugs and combustion control.

Background Art

[0002] Both glow engines and diesel engines have used glow plugs.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Non-Patent Documents

[0004]

Non-Patent Document 1

Non-Patent Document 2

Non-Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0005] Aiming to have a greater effect than the essentially variable cylinder system and fewer malfunctions. In conventional gasoline engines, homogeneous mixture combustion is achieved by fuel injection in the intake pipe. In the direct injection system, stratified mixture combustion and homogeneous mixture combustion are used appropriately. Also, even in the case of the direct injection system, an electronically controlled throttle valve is retained. Therefore, there is still room for improvement in pump losses. Furthermore, there is significant room for improvement in cooling losses at low loads, whether it is fuel injection in the intake pipe or the direct injection system. To solve this problem, after adopting the direct injection system, the issues are how to form the air-fuel mixture in the combustion chamber and how to ignite the air-fuel mixture. That is, the fuel injection form and the method of igniting the injected fuel also become problems. Also, in diesel engines, the injected fuel in the combustion chamber is made into a good air-fuel mixture state by a swirl flow and is made into uncontrolled combustion that generates countless ignition sources. Literally, it is also a problem that combustion control is not easy. Fundamentally, with the idea of a conventional diesel engine, for example, the combustion of a diesel engine in the sense of using light oil with a compression ratio of 12 has not been achieved. This is because it is premised on injecting fuel in a mist form into high-temperature air with a high compression ratio and burning it. The problems are that the engine noise is high, the engine weight is heavy, and the price is high in order to achieve a high compression ratio for air. Furthermore, in diesel engines, the generation of soot and nitrogen oxides increases when one is reduced and the other increases, which is also a problem.

Means for Solving the Problem

[0006] Use a glow plug with a recess at the tip. In a four-stroke direct injection engine with a compression ratio from 5 to 20, toward the recess of the glow plug with a recess at the tip according to claim 1, among the combustion obtained by the fuel injector injecting fuel within the range of top dead center of compression and its vicinity, make the combustion at low loads into a lump on the recess, and do not let it contact the combustion chamber wall, and adopt a method to reduce cooling losses at low loads.

[0007] As a means, to put it from the conclusion, combustion can be controlled. A glow plug having a recess at its tip is projected into the combustion chamber. In a four-stroke direct injection engine, the combustion at low load is made into a partial lump in the combustion chamber and is wrapped with air and the recess according to Claim 1. As the means, a method is adopted in which a single-port fuel injector injects fuel within the range of the top dead center of compression and its vicinity toward the recess according to Claim 1. That is, fuel injection is performed at the same timing as that of a diesel engine toward the recess so that the atomizing power and ignition power of the recess can be utilized. Further, by supporting the recess, it is possible to freely set the position of the recess in the combustion chamber. A single-port fuel injector, a variable swirl intake port, a piston with the smallest possible squish area in a piston engine, and a glow plug having a recess at its tip are used for both gasoline engines and diesel engines.

Effect of the Invention

[0008] In both gasoline engines and diesel engines, the high-density part of the injected fuel comes into contact with the depression, so misfiring does not occur and combustion control becomes easy. Under the condition of weakly stirring with the weak swirl flow of the variable swirl intake port and the weak squish flow of the piston at low load, the combustion can be wrapped by the depression of air and the glow plug, and the best reduction of cooling loss can be achieved with the current technology. For example, in a gasoline engine, the fuel consumption during urban driving of a passenger car can be reduced by half compared with the conventional in-cylinder fuel injection. Also, the fuel consumption during idling is extremely low, and the idling stop that burdens the battery can be eliminated. Furthermore, pump loss can also be reduced. At low load in both conventional diesel engines and gasoline engines, the combustion can be wrapped by the depression of air and the glow plug under the weak swirl flow of the variable swirl intake port and the weak squish flow of the piston. At medium load, the combustion by the injected fuel of a single-port fuel injector can be made to contact only a part of the combustion chamber wall under the medium swirl flow of the variable swirl intake port and the weak squish flow of the piston. In the combustion at high load, the combustion by the single-port fuel injector can be made to approach homogeneous mixture combustion under the strong swirl flow of the variable swirl intake port and the weak squish flow of the piston. Also, in the four-stroke direct injection engine adopting the present invention with a compression ratio of 10 or less, hydrogen and synthetic fuel can also be used.

[0009] When the present invention is adopted as an improvement for a diesel engine with a compression ratio of 20, the high-temperature air and the force of the depression complement each other, so combustion can occur even when the compression ratio is lowered. For example, in a diesel engine in the sense of using diesel oil (gas oil) with a compression ratio of 12, as an effect related to the depression of Claim 1, the compression ratio can be lowered, and combustion is carried out under weak, medium, and strong swirl flows and a weak squish flow made effective by a variable swirl intake port, so that the problems of the generation of soot and nitrogen oxides are solved all at once by complete combustion at a low temperature. The glow plug having a depression at its tip can also atomize the injected fuel. Instead of the uncontrolled combustion peculiar to conventional diesel engines, combustion can be wrapped and controlled by air and the depression even at low loads in a diesel engine in the sense of using gas oil with a low compression ratio. Furthermore, noise, the weight of the engine, and the price can be reduced due to the decrease in the compression ratio.

[0010] Alternatively, in addition to the high-temperature air with a high compression ratio of 20 in a conventional diesel engine, by using the force of the depression, Patent No. 7429859, and any one of weak, medium, and strong swirl flows and a weak squish flow, complete combustion of 100% unprocessed vegetable oil can be achieved. When vegetable oil is produced, it absorbs carbon dioxide by photosynthesis, so the generation of carbon dioxide can be substantially zero. Self-sufficiency in energy sources can also be achieved. At low loads, the ignition delay of the injected fuel is utilized to create a combustion mass that can be wrapped by air and the depression. Incidentally, the high-temperature air and the force of the depression complement each other in the work of fuel ignition.

[0011] Generally speaking, in the four-stroke direct injection engine according to the effect of the present invention, the compression ratio can be freely selected within the range from 5 to 20, and the combustion control becomes easy. When designing the engine, the compression ratio of the engine using the present invention can be freely selected. Therefore, the fuel to be used can be freely selected from hydrogen, synthetic fuel, ethanol, methanol, kerosene, light oil, heavy oil, and low-quality heavy oil. That is to say, the engine can be named not only by the compression ratio but also by the fuel used. Incidentally, the present invention exhibits the most advantageous effect of reducing cooling loss in large-displacement gasoline engines. Reducing gasoline consumption by half also contributes to reducing the environmental load. Eventually, due to the diversity of the fuel used, the boundaries between the slug engine, gasoline engine, diesel engine, and glow engine can be eliminated. Furthermore, in the intake stroke of the piston, a swirl flow with an arbitrary intensity can be generated in the variable swirl intake port for the swirl flow, and for the squish flow, the generation of the squish flow can be reduced by making the squish area of the piston as small as possible. Therefore, the combustion is under the influence of the state mainly based on the swirl flow of the variable swirl intake port where the control is easy. As described above, in the four-stroke direct injection engine with a compression ratio from 5 to 20, the combustion can be made into a partial lump in the combustion chamber at low load. At medium load, the combustion can be made to contact only a part of the inner wall of the combustion chamber. At high load, it can be made close to homogeneous mixture combustion.

Brief Description of the Drawings

[0012]

Figure 1

Figure 2

Modes for Carrying Out the Invention

[0013] In gasoline engines and diesel engines, as a conical combustion chamber obtained by digging out a flat cylinder head and a piston, the skish area that structurally occurs there is made as small as possible to generate a weak skish flow, and combustion is under the influence mainly of weak, medium, and strong swirl flows by a variable swirl intake port that is easy to control. In gasoline engines, the conical combustion chamber is made deep, and in diesel engines, it is made shallow. In both gasoline engines and diesel engines, at low loads, the variable swirl intake port is made to act weakly, and all the injected fuel from a single-orifice fuel injector is received in a depression under a weak skish flow. Then, the injected fuel is atomized, ignited, and made into a partial combustion mass in the combustion chamber, and is wrapped by the depression of air and the glow plug. Starting a conventional diesel engine in cold weather is difficult because it is hard to obtain high-temperature air, so the depression of the glow plug is used to assist atomization, ignition, and create a combustion mass, and the combustion is wrapped by air and the depression under a weak swirl flow and a weak skish flow. Even after warm-up, there is an ignition delay in the injected fuel, so a combustion mass is created at low loads and wrapped by air and the depression.

Embodiment

[0014] The combustion chambers of both diesel engines and gasoline engines are conical combustion chambers with a flat cylinder head and a piston dug out, and a small skish area is created around the combustion chamber, so the swirl flow and the skish flow are effective even at and around top dead center of compression.

Explanation of Signs

[0015] 1 Conical depression 2 Support part of the conical depression 3 Variable swirl intake port 4 Single-orifice fuel injector 5 Compressed air in the conical combustion chamber dug out by the piston 6 Electric wire 7 Combustion mass 8 Skish area made as small as possible

Claims

1. A combustion chamber with a partially double bottom obtained by protruding a glow plug having a conical recess with its tip at the center of the flat crown surface of the piston at top dead center into a conical combustion chamber formed by digging into the flat crown surface of the piston in a four-stroke direct injection engine, which receives all of the injected fuel during low load operation.

2. A combustion control method for a combustion chamber with a partially double bottom according to Claim 1 of a four-stroke direct injection engine, wherein a single-port fuel injector, assuming a weak squish flow in a squish area made as small as possible and variable swirl flows of weak, medium, and strong, injects fuel toward the conical recess according to Claim 1, and the combustion obtained thereby is wrapped by compressed air under a weak swirl flow and the conical recess during low load operation without contacting the inner wall of the conical combustion chamber, contacts only a part of the inner wall of the conical combustion chamber under a medium swirl flow during medium load operation, and approaches homogeneous mixture combustion under a strong swirl flow during high load operation.

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