CN102588105B - Negative pressure type engine and working cycle process thereof - Google Patents

Abstract

The invention discloses a negative pressure engine and its working cycle process. It is composed of a body, a cylinder, a cylinder head, a piston, a combustion system, a gas distribution mechanism and a crankshaft connecting rod mechanism. There are intake valves and exhaust valves on the top; the gap between the piston and the cylinder head when it is at the top dead center is enough to ensure that the piston does not touch the cylinder head, and the contact sealing surface of the intake valve, exhaust valve and the cylinder head is set on the cylinder. The top surface of the cover, the entire cylinder space when the piston is at the bottom dead center is used as the combustion chamber, and the fuel injector and spark plug of the combustion system are installed at the bottom dead center of the piston on the cylinder wall. In the present invention, under the condition of the same fuel consumption, as long as the cylinder diameter is appropriately increased, the power generated is much larger, the noise is reduced, and the fuel is saved. <!-- 2 -->

Description

Negative pressure engine and its working cycle process

technical field

This invention relates to engines.

Background technique

The engine is the power source of the car, and the engine is also widely used in various aspects such as transportation machinery, agricultural machinery, construction machinery and generator sets. There are many types of engines, among which two-stroke and four-stroke engines are the most common, belonging to reciprocating piston internal combustion engines. The internal combustion engine converts the heat energy generated by fuel combustion into mechanical energy by means of the state change of the working fluid. According to the type of fuel used, it is divided into three categories: gasoline engine, diesel engine and gas fuel engine. They all rely on the high temperature and high pressure generated by fuel combustion to perform work.

The main structure of the engine is composed of the body, cylinder, cylinder head, piston, combustion system, valve mechanism, crankshaft and connecting rod mechanism and other components.

The working principle of the two-stroke engine is that there are three holes on the cylinder block, namely the intake hole, the exhaust hole and the ventilation hole, and these three holes are respectively closed by the piston at a certain moment; its working cycle includes two strokes: 1. The first stroke: the piston moves upward from the bottom dead center, and the mixture gas entering the cylinder is compressed after the three air holes are closed at the same time; when the air intake hole is exposed, the combustible mixture flows into the crankcase; 2. The second stroke: piston compression When near the top dead center, the spark plug ignites the combustible mixture, and the expansion of the gas pushes the piston down to do work. At this time, the intake hole is closed, and the combustible mixture sealed in the crankcase is compressed; when the piston is close to the bottom dead center, the exhaust hole opens, and the exhaust gas rushes out; then the ventilation hole opens, and the pre-pressurized combustible mixture rushes in. Cylinder, expels exhaust gas, and carries out the ventilation process. The advantages of two-stroke engines are: 1. Two-stroke engines have no valves, which greatly simplifies their structure and reduces their weight; 2. Two-stroke engines ignite once per revolution, and they have double power per revolution 3. A two-stroke engine can run in any orientation, which is important on certain equipment such as a chainsaw. These advantages make the two-stroke engine more portable, easy, and the manufacturing cost is low, and the combination of lightness and double power makes it better than the four-stroke engine. However, the lubrication system of the two-stroke engine is insufficient, the components are worn out quickly, the fuel efficiency is not high, and the lubricating oil is burned, causing air pollution. These deficiencies mean that two-stroke engines can only be used where the motor is used infrequently and the "thrust-to-weight ratio" is important.

The working principle of the four-stroke engine is that the cylinder head is equipped with intake valves and exhaust valves, the contact sealing surface of the intake valves, exhaust valves and the cylinder head is the bottom surface of the cylinder head, and the fuel injector of the combustion system is installed on the cylinder head. Inject oil upward toward the bottom of the cylinder. Through the opening and closing of the intake and exhaust valves, the air is charged into the cylinder and the exhaust is exhausted outside the cylinder. The four-stroke gasoline engine completes a working cycle in the intake stroke, compression stroke, power stroke and exhaust stroke. During the intake stroke, the intake valve opens, the exhaust valve closes, the crankshaft rotates 180°, the piston moves from the top dead center to the bottom dead center driven by the crankshaft, and the mixture of air and gasoline is sucked in through the intake valve Cylinder, and further mixed in the cylinder to form a combustible mixture; during the compression stroke, the intake and exhaust valves are closed at the same time, the piston moves from the bottom dead center to the top dead center, the crankshaft rotates 180°, the pressure and temperature of the compressed gas in the cylinder During the power stroke, the intake valve and exhaust valve are closed, and the crankshaft rotates 180°. When the piston is close to the top dead center, the spark plug ignites the combustible mixture, and the combustion of the mixture releases a large amount of heat energy. High temperature and high pressure The gas pushes the piston to move from the top dead center to the bottom dead center, and outputs mechanical energy through the crank connecting rod mechanism; during the exhaust stroke, the exhaust valve opens, the intake valve remains closed, the piston moves from the bottom dead center to the top dead center, and the crankshaft Turning 180°, the exhaust gas after combustion is exhausted outside the cylinder due to the pressure difference inside and outside the cylinder and the displacement of the piston. Although the four-stroke engine overcomes the shortcoming of the two-stroke engine, it does not possess the advantages of the two-stroke engine.

Contents of the invention

In order to retain the advantages of lightness, simplicity and low manufacturing cost of the existing two-stroke engine, the present invention improves the four-stroke engine to provide a negative pressure engine.

In order to achieve the above object, the technical scheme adopted by the negative pressure engine of the present invention is; The cover is equipped with an intake valve and an exhaust valve; its characteristic is that the gap between the piston and the cylinder head when it is at the top dead center ensures that the piston does not touch the cylinder head, and the contact between the intake valve and the exhaust valve and the cylinder head The sealing surface is set on the top surface of the cylinder head, the entire cylinder space when the piston is at the bottom dead center is used as the combustion chamber, and the fuel injector and spark plug of the combustion system are installed at the bottom dead center of the piston on the cylinder wall.

Its working cycle process is: 1. The first process, when the piston starts to descend at the top dead center, the intake valve opens, the exhaust valve closes, the air filtered by the filter enters the combustion chamber, and when the piston descends to the bottom dead center , the intake valve is closed, the fuel injector is opened and the spark plug is ignited, the exhaust valve is opened at the moment of ignition, and then closed instantly; 2. In the second return stroke, the piston moves upward from the bottom dead center under the action of negative pressure. At the top dead center, the exhaust valve opens, the exhaust gas rushes out, and turns to the first process.

The working principle is that in the first process, the air filtered by the filter enters the combustion chamber. In the second return process, the fuel injection is mixed with the air and is first ignited by the spark plug. The combustion consumes part of the oxygen in the cylinder and expands the gas in the tank. At this time, the exhaust valve opens and closes instantly to remove the excess expansion gas in the tank, so that the pressure inside and outside the cylinder is equalized. After the exhaust valve is closed instantly, the cylinder is closed. Shrinking, so that the air pressure in the cylinder is lower than the outside atmospheric pressure (collectively referred to as negative pressure), so that the piston moves up to generate power.

The fuel in the engine of the present invention only plays an auxiliary role, not as a direct source of power. Compared with the traditional engine, the power generated by appropriately increasing the cylinder bore is much larger under the same fuel consumption. Because the fuel is only combusted instead of deflagrated, the noise is greatly reduced; because there is no compression stroke in the work, no energy is consumed, so fuel is also saved; because the intake valve and exhaust valve are located on the top surface of the cylinder head, there is no valve generation After falling in, the top cylinder phenomenon occurs.

Description of drawings

Fig. 1, Fig. 2 are the schematic diagrams of the principle of the embodiment of the present invention, in the figure only single-cylinder engine is taken as an example, wherein

Figure 1 is the situation when the piston is at the top dead center, and Figure 2 is the situation when the piston is at the bottom dead center.

Legend shows, 1-crankshaft connecting rod mechanism, 2-cylinder, 3-piston, 4-exhaust valve, 5-intake valve, 6-fuel injector and spark plug, 7-cylinder head, 8-combustion chamber.

detailed description

As shown in Figures 1 and 2, a negative pressure engine is composed of a body, a cylinder 2, a cylinder head 7, a piston 3, a combustion system, a gas distribution mechanism and a crankshaft connecting rod mechanism 1 and other components. The air mechanism is equipped with an intake valve 5 and an exhaust valve 4 on the cylinder head 2; wherein, the gap between the piston 3 and the cylinder head 7 when the piston 3 is at the top dead center can ensure that the piston 3 does not touch the cylinder head 7, generally not More than 2mm, that is, only a small free gap is set, the contact sealing surface of the intake valve 5 and exhaust valve 4 and the cylinder head 7 is set on the top surface of the cylinder head 7, and the entire cylinder space when the piston 3 is at the bottom dead center is used as the combustion chamber 8. The fuel injector and spark plug 6 of the combustion system are installed at the bottom dead center of the piston 3 on the cylinder wall;

Its working cycle process is: 1. The first process, when the piston 3 starts to descend at the top dead center, the intake valve 5 opens, the exhaust valve 4 closes, the air filtered by the filter enters the combustion chamber 8, and the piston 3 descends When reaching the bottom dead center, the intake valve 5 is closed, the fuel injector is opened and the spark plug 6 is ignited, the exhaust valve 4 is opened at the moment of ignition, and the exhaust valve 4 is closed at the moment; 2. The second return stroke: the piston 3 is in the Under the action of negative pressure, it moves upward from the bottom dead center, and when the piston 3 approaches the top dead center, the exhaust valve 4 opens, and the exhaust gas rushes out, turning into the first process.

Claims (2)

1. a negative pressure type engine, it is by body, cylinder, cylinder cover, piston, combustion system, valve actuating mechanism and bent axle even

Linkage parts form, and valve actuating mechanism is equipped with inlet valve and exhaust valve on cylinder cover；It is characterized in that, it is close with contacting of cylinder cover less than cylinder cover, inlet valve and exhaust valve that piston gap when top dead centre and between cylinder cover ensures that piston touches

Front cover is located at the end face of cylinder cover, and the piston whole cylinder space when lower dead center is as combustor, the atomizer of combustion system

It is arranged at the piston lower dead center of cylinder wall with spark plug.

2. the working cycle process of a negative pressure type engine as claimed in claim 1, it is characterised in that the first process, when

Piston is when top dead centre starts descending, and IO Intake Valve Opens, exhaust valve closing, filtered device filtered air enters combustor, lives

Plug is when coming downwards to lower dead center, IC Intake Valve Closes, and atomizer is opened and plug ignition, and the moment exhaust valve of igniting is opened therewith,

And moment closedown；Second backhaul, piston moves up from lower dead center under suction function, exhaust valve when the piston is near the top dead centre

Opening, waste gas is gone out, and proceeds to the first process.