Air inlet device of two-stroke heavy oil engine

Abstract

The invention provides an air inlet device of a two-stroke heavy oil engine, and belongs to the field of engine air inlet system design. In order to solve the problems that an existing multi-cylinder two-stroke heavy oil engine is large in number of throttle valves, large in control difficulty and low in air inlet efficiency, the device is formed by sequentially connecting an air filter, the throttle valves, an air inlet pipe, a reed valve upper seat, a reed valve, a reed valve mounting seat and a reed valve lower seat, the air inlet pipe comprises a pressure stabilizing cavity and an air inlet manifold, and the reed valve is a one-way valve. When an engine sucks air, the reed valve is opened, and fresh air enters the air cylinder through the pressure stabilizing cavity of the air inlet pipe, the air inlet manifold and the reed valve after being filtered and regulated by the throttle valve; when the gas inlet is closed, the reed valve prevents gas backflow, and the pressure stabilizing cavity can reduce gas inlet pressure wave reflection so as to reduce resistance. According to the device, the number of throttle valves is reduced, the air inlet stability and the air inlet efficiency are improved, the scavenging efficiency and the control efficiency of an engine controller are improved, and the device is suitable for performance optimization of the two-stroke heavy oil engine.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of engine intake system design, more particularly, relates to a two-stroke heavy oil engine intake device. BACKGROUND

[0002] At present, the development system of aviation heavy oil piston engine in China is not perfect, and there are fewer mature products. In the field of aviation heavy oil engine, there is a strong dependence on imported products. Most of the existing heavy oil engines in China are based on vehicle engines, and such modified products generally have the defects of large weight and volume, low power-to-weight ratio, and obvious vibration, which are difficult to meet the performance requirements of the main engine for the power system.

[0003] In the performance improvement of two-stroke engines, the improvement of intake efficiency is one of the key links, which can significantly improve the engine performance and increase the power-to-weight ratio of aviation piston engines. The existing two-stroke engine intake method is piston natural aspiration. To ensure sufficient fresh air supply, the intake port is usually connected to the atmosphere through a throttle valve and an air filter. However, for multi-cylinder engines, this method undoubtedly increases the number of throttle valves and greatly increases the difficulty of throttle opening control. At the same time, due to the periodic opening and closing characteristics of the intake port, the natural aspiration process is prone to reduce the intake efficiency, which restricts the further improvement of engine performance.

[0004] To solve the problems of throttle control difficulty and low intake efficiency of multi-cylinder two-stroke heavy oil engines, the present application designs a new type of intake system device based on the principle of intake pressure stabilization. SUMMARY

[0005] To solve the above technical problems, the present application provides a two-stroke heavy oil engine intake device to solve the above problems.

[0006] A two-stroke heavy oil engine intake device, comprising a throttle valve, an intake pipe, a reed valve upper seat, a reed valve, a reed valve mounting seat, a reed valve lower seat, an engine cylinder body and an air filter;

[0007] The air filter is connected to the air inlet of the throttle valve, the outlet of the throttle valve is connected to the inlet of the intake pipe, and the outlet of the intake pipe is connected to the reed valve upper seat;

[0008] The reed valve mounting seat, the reed valve, and the reed valve upper seat are connected to the reed valve lower seat by long bolts, and the main body of the reed valve is located inside the reed valve mounting seat;

[0009] The reed valve lower seat is connected to the intake port of the engine cylinder body;

[0010] The intake pipe comprises a pressure stabilization chamber and an intake manifold, one end of the intake manifold is in communication with the pressure stabilization chamber, the other end is connected to the reed valve upper seat, and the pressure stabilization chamber is connected to the outlet of the throttle valve.

[0011] The reed valve is a one-way valve, and the reed valve is opened when the engine inhales, and fresh air enters the engine cylinder body in sequence through the air filter, the throttle valve, the intake pipe, the upper seat of the reed valve, the reed valve and the lower seat of the reed valve.

[0012] During the closing process of the engine intake port, the reed valve is closed to prevent gas from flowing back to the intake pipe.

[0013] Preferably, the intake manifold is provided in multiple, and the axes of the intake manifolds are equal in length, the cross section of the intake manifold is circular, the inner diameter is 40 mm, the wall thickness is 2 mm, and the axis length is 125 mm, and the cross section of the stable pressure cavity is circular, the diameter is 65 mm, and the length L is 230 mm.

[0014] Preferably, the throttle valve is an electronic throttle valve.

[0015] The inner diameter of the inlet of the intake pipe is 57 mm, the wall thickness is 2 mm, the intake port length is 40 mm, and the inlet diameter of the intake pipe is greater than the outlet diameter of the throttle valve.

[0016] Preferably, the reed valve mounting seat, the reed valve, and the upper seat of the reed valve are connected to the lower seat of the reed valve through four long bolts.

[0017] Preferably, when the engine inhales, the engine cylinder body intake port is opened, a negative pressure is formed in the cylinder, the reed valve is opened, fresh air is filtered through the air filter, the air volume is adjusted through the throttle valve, and then the fresh air enters the cylinder in sequence through the intake pipe, the upper seat of the reed valve, the reed valve and the lower seat of the reed valve.

[0018] When the engine works, a high pressure is formed in the cylinder, the exhaust port is opened, the exhaust gas is discharged, then a negative pressure is formed in the cylinder again, and the cycle works.

[0019] Compared with the prior art, the present application has the following beneficial effects:

[0020] 1. Significantly improve the intake efficiency: the present application sets the intake pipe with a stable pressure cavity, effectively solves the problem of intake obstruction caused by pressure wave reflection in the traditional two-stroke engine intake process. The traditional intake pipe without a stable pressure cavity will produce strong pressure wave reflection when the intake port is closed, increasing the intake resistance; while the stable pressure cavity (circular cross section, diameter φ65mm, length L=230mm) of the present application can accommodate the reflected pressure wave and reduce its intensity, greatly reducing the intake obstruction. At the same time, the inlet diameter of the intake pipe (φ57mm) is greater than the outlet diameter of the throttle valve, which follows the principle of fluid flow to avoid throttling, further reducing the natural intake resistance. The above design works together to significantly improve the intake efficiency, providing more sufficient fresh air for engine combustion, which helps to improve the engine power and power-to-weight ratio.

[0021] 2、 effectively improve the scavenging efficiency: the reed valve as a one-way valve plays a key role in the engine working cycle: when the engine inhales, the reed valve opens with the negative pressure in the cylinder, ensuring that fresh air enters smoothly; during the overlap of the intake and exhaust ports or the closing of the intake port, the air in the box is compressed to form positive pressure, and the reed valve will block the backflow of gas to the intake pipe, preventing fresh air from mixing with exhaust gas or being lost. This one-way cutoff function ensures the effective use of fresh air during the scavenging process, reduces the scavenging loss, significantly improves the scavenging efficiency, and optimizes the combustion effect.

[0022] 3、 improve the control efficiency of the engine controller: traditional multi-cylinder two-stroke engines require an independent throttle valve for each cylinder, resulting in a large number of throttle valves and complex opening degree control, increasing the burden of the engine controller. The invention uses a single throttle valve (electronic throttle valve) to control the overall intake volume, and the air is distributed to each cylinder through the intake manifold of the intake pipe, significantly reducing the number of throttle valves. This design simplifies the throttle opening degree control logic, reduces the controller's operation and control difficulty, makes the intake volume adjustment more accurate and the response more rapid, and significantly improves the control efficiency of the engine controller. BRIEF DESCRIPTION OF DRAWINGS

[0023] Fig. 1 is the intake system assembly diagram in the invention;

[0024] Fig. 2 is the reed valve installation diagram in the invention;

[0025] Fig. 3 is the intake pipe structure diagram in the invention.

[0026] In the figure, the correspondence between the component name and the figure number is as follows: 1, throttle valve; 2, intake pipe; 3, reed valve upper seat; 4, reed valve; 5, reed valve mounting seat; 6, reed valve lower seat; 7, engine cylinder block. DETAILED DESCRIPTION

[0027] The embodiments of the invention will be further described in detail below in combination with the drawings and examples. The following examples are used to illustrate the invention, but cannot be used to limit the scope of the invention.

[0028] Please refer to Figs. 1-3 , the invention provides a two-stroke heavy oil engine intake device, which includes a throttle valve 1, an intake pipe 2, a reed valve upper seat 3, a reed valve 4, a reed valve mounting seat 5, a reed valve lower seat 6, an engine cylinder block 7, and an air cleaner;

[0029] Among them, the overall installation connection relationship is:

[0030] The air inlet of the engine cylinder block 7 is connected with the leaf valve lower seat 6 by bolts; the leaf valve mounting seat 5, the leaf valve 4 and the leaf valve upper seat 3 are sequentially connected on the leaf valve lower seat 6 by four long bolts, wherein the main body of the leaf valve 4 is located inside the leaf valve mounting seat 5; the air inlet pipe 2 is connected with the leaf valve upper seat 3 by bolts; the electronic throttle valve 1 is connected with the air inlet pipe 2 by bolts, and the air inlet of the electronic throttle valve 1 is connected with an air cleaner to form a complete air inlet passage.

[0031] Working cycle process:

[0032] Suction stage: the air inlet of the engine cylinder block 7 is opened, and a negative pressure is formed in the cylinder, which causes the leaf valve 4 to open. Fresh air is filtered through an air cleaner first, then enters the electronic throttle valve 1, and then sequentially passes through the air inlet pipe 2, the leaf valve upper seat 3, the leaf valve 4 and the leaf valve lower seat 6, and finally fills the lower part of the engine cylinder block 7 and the box to form a positive pressure area; at this time, the combustion chamber in the upper part of the engine cylinder block 7 is a negative pressure area, and under the action of the pressure difference, fresh air enters the upper combustion chamber through the cylinder body scavenging port to participate in the subsequent compression and combustion work.

[0033] Work and exhaust stage: when the engine works, the combustion chamber in the upper part of the cylinder block becomes a high pressure area, and then the exhaust port of the cylinder block gradually opens, and the exhaust gas is discharged; after the exhaust process is completed, the combustion chamber in the upper part of the cylinder block becomes a negative pressure area again, and enters the next working cycle, and so on.

[0034] The main body of the air inlet pipe 2 is divided into a pressure stabilizing chamber and an air inlet manifold, one end of the air inlet manifold is communicated with the pressure stabilizing chamber, the other end is connected with the leaf valve upper seat 3, and the pressure stabilizing chamber is connected with the outlet of the electronic throttle valve 1.

[0035] The size of the air inlet pipe: according to the principle of fluid flow, in order to prevent throttling, the inlet diameter of the air inlet pipe 2 is greater than the outlet diameter of the electronic throttle valve 1. For an engine displacement of 1350cc, the outlet diameter of the electronic throttle valve 1 is φ44~φ57mm, so the inlet diameter of the air inlet pipe 2 is φ57mm, the wall thickness is 2mm, and the length of the air inlet is 40mm.

[0036] The size of the air inlet manifold: since the area of the air inlet of the cylinder block is 1560mm², the cross section of the air inlet manifold is circular, and the diameter φ≥22.2mm; considering that two cylinders may work at the same time, the inner diameter of the air inlet manifold is φ40mm, and the wall thickness is 2mm; at the same time, each air inlet manifold is designed according to the equal length principle, and the axial length is uniformly 125mm according to the actual installation requirement.

[0037] The size of the pressure stabilizing chamber: the cross section of the pressure stabilizing chamber is circular, the diameter φ=65mm, and the length L=230mm.

[0038] Effect: for the intake pipe 2 without the stable pressure chamber, when the air inlet is opened, fresh air can flow into the cylinder, but when the air inlet is closed, a certain pressure wave is reflected in the intake pipe 2, resulting in large intake resistance and low intake efficiency; while the intake pipe 2 with the stable pressure chamber, the reflected pressure wave enters the large volume stable pressure chamber, and the pressure is reduced, effectively reducing the intake resistance and improving the intake efficiency.

[0039] The reed valve 4 is a one-way valve, and its core function is to prevent gas backflow. When the engine inhales, the reed valve 4 is opened to ensure that the gas flows smoothly into the cylinder; when the engine air inlet is gradually closed, the air in the box is compressed, the pressure increases, and the gas flowing to the reed valve 4 is blocked, thereby preventing the gas from flowing back to the intake pipe 2, and ensuring the scavenging efficiency.

[0040] Embodiments of the present application are given for the purpose of illustration and description, and are not intended to be exhaustive or to limit the application to the form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art. Embodiments are chosen and described in order to best explain the principles of the application and its practical application, and to enable others skilled in the art to understand the application for various embodiments with various modifications as are suited to the particular use contemplated.

Claims

1. An intake device for a two-stroke heavy oil engine, characterized in that, Includes throttle body (1), intake manifold (2), upper reed valve seat (3), reed valve (4), reed valve mounting seat (5), lower reed valve seat (6), engine cylinder block (7) and air filter; The air filter is connected to the air inlet of the throttle valve (1), the outlet of the throttle valve (1) is connected to the inlet of the intake pipe (2), and the outlet of the intake pipe (2) is connected to the upper seat of the reed valve (3). The reed valve mounting seat (5), the reed valve (4), and the upper reed valve seat (3) are connected to the lower reed valve seat (6) by long bolts, and the main body of the reed valve (4) is located inside the reed valve mounting seat (5); The lower seat of the reed valve (6) is connected to the air inlet of the engine cylinder block (7); The intake pipe (2) includes a pressure regulating chamber and an intake manifold. One end of the intake manifold is connected to the pressure regulating chamber, and the other end is connected to the upper seat of the reed valve (3). The pressure regulating chamber is connected to the outlet of the throttle valve (1). The reed valve (4) is a one-way valve. When the engine draws in air, the reed valve (4) opens and fresh air enters the engine cylinder block (7) in sequence through the air filter, throttle valve (1), intake pipe (2), upper seat of reed valve (3), reed valve (4), and lower seat of reed valve (6). During the engine intake closure process, the reed valve (4) closes to prevent gas from flowing back into the intake pipe (2).

2. The apparatus according to claim 1, characterized in that, The intake manifold is configured as multiple units, and the axial length of each intake manifold is equal. The cross-section of the intake manifold is circular, with an inner diameter of φ40mm, a wall thickness of 2mm, and an axial length of 125mm.

3. The apparatus according to claim 1, characterized in that, The cross-section of the voltage stabilizing cavity is circular, with a diameter of φ65mm and a length of L=230mm.

4. The apparatus according to claim 1, characterized in that, The throttle valve (1) is an electronic throttle valve; The intake pipe (2) has an inlet inner diameter of φ57mm, a wall thickness of 2mm, an intake port length of 40mm, and an inlet diameter of the intake pipe (2) is greater than the outlet diameter of the throttle valve (1).

5. The apparatus according to claim 1, characterized in that, The reed valve mounting seat (5), reed valve (4), and reed valve upper seat (3) are connected to the reed valve lower seat (6) by four long bolts.

6. The apparatus according to claim 1, characterized in that, When the engine is drawing in air, the intake port of the engine cylinder block (7) is opened, a negative pressure is formed in the cylinder, the reed valve (4) is opened, and fresh air is filtered by the air filter and the air volume is regulated by the throttle valve (1). Then, it enters the cylinder in sequence through the intake pipe (2), the upper seat of the reed valve (3), the reed valve (4), and the lower seat of the reed valve (6). When the engine is working, high pressure is formed inside the cylinder, the exhaust port opens, and exhaust gas is discharged. Then, negative pressure is formed inside the cylinder again, and the cycle continues.

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