WO2002014561A1

WO2002014561A1 - Engine silencer for controlling back pressure and gas leakage

Info

Publication number: WO2002014561A1
Application number: PCT/CN2000/000243
Authority: WO
Inventors: Jefferson Liu
Original assignee: Jefferson Liu
Priority date: 2000-08-18
Filing date: 2000-08-18
Publication date: 2002-02-21
Also published as: GB2383091A; CN1454286A; GB0303498D0; AU2000265542A1

Abstract

The present invention relates to an engine silencer for controlling back pressure and gas leakage. The silencer includes an outer tube, an inner tube coaxial through the outer tube, plates with holes disposed at the space between the inner and outer tubes, and convergent tubes spaced located in the inner tube to accelerate the gases into the inner tube and assistant the exhaust valve of the engine. Between opening of exhaust valve and dead of bottom of the piston, the silencer has a high back pressure to resistance the leakage of the gases expanding in the cylinder.

Description

Muffler for priming with enhanced back pressure and leakage

The present invention relates to a muffler for an engine that enhances back pressure and leakage, and in particular cooperates with the timing operation of the engine's valve to generate a large amount of back pressure in the time before the piston reaches the bottom dead center after the exhaust valve is opened to resist exhaust A large amount of gas leaks after the gas valve is opened, so that the engine's expansion stroke can fully operate. And when the piston enters the exhaust stroke, its internal resistance is reduced to achieve a sufficient exhaust, but also has the purpose of better muffler for engine muffler. Background technique

Existing gasoline stroke cycle engines include four strokes: intake, compression, expansion, and exhaust. As shown in the schematic diagram of the valve timing shown in Figure 3, in the existing engine design, the exhaust valve needs to be opened before the engine piston reaches the bottom dead center (as shown in the clockwise stroke from A to B in Figure 3). Exhaust (as shown in point D in Figure 3), but the efficiency of the engine is reduced due to the large amount of gas leaking after the exhaust valve is opened. In addition, in the traditional design, when the piston enters the exhaust stroke, the resistance is large, and the exhaust effect is poor. Disclosure of invention

The purpose of the present invention is to provide a muffler for an engine that enhances back pressure and leakage, and makes it cooperate with the engine's valve to operate at a regular time, and generates a large number of times before the piston reaches the bottom dead center after the exhaust valve is opened. Pressure to resist the exhaust of a large amount of gas after the exhaust valve is opened, so that the engine's expansion stroke can fully operate, and when the piston enters the exhaust stroke, its internal resistance is reduced to achieve the effect of full exhaust; and it has a better silence Role, and the structure is more streamlined.

The present invention is designed to improve the shortcomings of low engine efficiency and poor exhaust effect due to the large amount of gas leakage after the exhaust valve is opened in the existing engine design. It includes an outer tube, an inner tube is axially penetrated in the outer tube, the inner tube wall has a plurality of small holes, the inner tube has a plurality of shrinkable tubes spaced apart at an appropriate distance, the inner wall of the outer tube and the outer wall of the inner tube There are multiple partitions in between, and there are multiple small holes on the partitions, which are used to make the exhaust gas flow from one end of the inner tube through the shrink tubes to accelerate the airflow, and cooperate with the engine's valve timing operation, and After the door is opened, a large amount of back pressure is generated in the time before the piston reaches the bottom dead center, which prevents a large amount of gas from leaking after the exhaust valve is opened, so that the engine expansion stroke can fully operate. And when the piston enters the exhaust stroke, a special design based on the principle of hydromechanical venturi shrinking is adopted. Because the exhaust gas passes through the venturi shrinking tube, the exhaust speed is accelerated, which is called "enhanced leakage" to make the exhaust The gas has a suction effect due to acceleration, which can exhaust the burned gas in the engine in a short time, reduce its internal resistance, and achieve the goal of not only sufficient exhaust but also better noise reduction. of. The tube of the drawings is to be explained

FIG. 1 is a sectional view of a three-dimensional structure of a muffler of the present invention;

2 is a schematic diagram of an exhaust condition of an inner pipe in a muffler of the present invention;

Fig. 3 is a schematic diagram of a valve timing of the muffler of the present invention. The best way to implement the invention

Fig. 1 is a sectional view showing a three-dimensional structure of a muffler for an engine for enhancing back pressure and leakage of the present invention. The structure for forming the muffler 1 is provided with an inner tube 12 axially penetrated in an outer tube 11, and the inner wall of the outer tube 11 and the outer wall of the inner tube 12 are closed; the inner tube There are a plurality of small holes 120 on the wall of 12 and there are a plurality of shrinkable tubes spaced at an appropriate distance inside the inner tube 12 (the embodiment of the present invention includes a first shrinkable tube 121 and a second shrinkable tube which are sequentially arranged 122 and third shrink tube 123]. The shrink tube is generally a dimensional shape similar to a nozzle structure, and the cross-sectional area of the first shrink tube 121 is larger than the second shrink tube 122, and the second shrink tube 122 is larger than The third shrinking tube 123 can accelerate the exhaust gas after passing through the shrinking tubes in order; there are multiple partitions 111 between the inner wall of the outer tube 11 and the outer wall of the inner tube 12, and the partition 111 has multiple small holes 1110 : The first partition 112, the second partition 113, and the third partition 114 are separated from each other by two partitions 111. One end of the inner tube 12 is connected to the exhaust port of the engine.

After the muffler for enhancing the back pressure and the leakage of the engine of the present invention is connected to the engine, when the engine starts to run, a small amount of gas previously discharged from the cylinder first fills the inside of the outer tube 11 of the muffler 1 to make it When a certain pressure is reached, and because of the continuous operation of the engine, the muffler 1 (ie, the exhaust pipe) of the present invention acts on the gas discharged from the engine cylinder according to the timing of the valve. Figure 2 shows the muffler of the present invention. When the exhaust valve is just opened (as shown in Figure 3: point D stroke), the exhaust gas 2 is transmitted to the inner pipe 12 of the muffler 1 and is subject to the constant pressure and A shrinking tube 121 produces a boosting effect, so that the back pressure (that is, the pressure returned to the cylinder) is greatly increased; when the piston continues to run from the bottom dead center (as shown in Figure 3: stroke at point B), it pushes A large amount of discharged gas enters the inner tube 12 again, so that the pressure in the first shrink tube 121 is further increased, so that the air flow through the first shrink tube 121 is accelerated (by the principle of Venturi shrink tube P1 * V1 two P2 * V2 ), So this accelerated airflow 2 acts to produce a boosting effect, and then accelerates the airflow passing through the second reduction tube 122, and this accelerated airflow acts on the third reduction tube 123. As a result of the acceleration of the airflow passing through the third reduction tube 123, the exhaust gas in the cylinder is rapidly Eliminate; from the piston approaching the top dead center (as shown in Figure 3: A stroke) to the exhaust valve closing (as shown in the figure) 3: C point stroke) During the process, the exhaust capacity is rapidly reduced. The gas flow velocity in the first shrink tube 121, the second shrink tube 122, and the third shrink tube 123 in the muffler 1 is relatively reduced. The closing of the valve causes the exhaust gas flow acting on the muffler 1 to be stopped momentarily. This shut-off phenomenon causes the pressure in the first shrink tube 121, the second shrink tube 122, and the third shrink tube 123 to drop sharply, and the exhaust air flow passing through the The first, second, and third shrinking tubes 121, 122. 12 generate pressure compensation after radial suction, so that the first region 112, the second region 113, and the third region 114 generate a pressure balancing effect and obtain a certain pressure value. This makes the muffler 1 have the above-mentioned effect on the next exhaust gas, so as to reach the bottom dead center of the piston just after the exhaust valve is opened (as shown in Fig. 3: point D) (as shown in Fig. 3: point B) ) Give full back pressure. When the piston enters the exhaust stroke (as shown in Figure 3: E point stroke), the internal resistance can be reduced to achieve a sufficient exhaust effect.

In addition, when the accelerated airflow passing through the second shrinking tube 122 travels, the radial pressure in the direction of the inner tube 12 in the second region 113 increases accordingly, so that the gas between the outer tube 11 and the inner tube 12 passes through the small hole 120. Being sucked into the inner tube 12, forcing the pressure in front of the second shrinking tube 122 to increase rapidly, and further accelerating the airflow after passing through the second shrinking tube 122. For the overall muffler, the airflow passes through the first, second and third regions 112, 113, 114, and the internal air pipe at 12 o'clock when the airflow in and out produces resonance cancellation effect, thereby achieving the muffler effect, and its structure is simpler than the traditional muffler. Industrial applicability

By cooperating with the timing operation of the engine's valve, the invention generates a large amount of back pressure in the time before the piston reaches the bottom dead center after the exhaust valve is opened. Operation, and reduce the internal resistance of the piston when it enters the exhaust stroke, which solves the shortcomings of gas leakage after the exhaust valve is opened in the existing engine design, which reduces the efficiency of the engine and the poor exhaust effect, with high work efficiency and savings Advantages of energy and reliability.

In addition, since the invention adopts a Venturi shrink tube and a cross-section increasing structure, the sound damping structure is simpler than the traditional muffler, and achieves a sufficient exhaust effect, and has the advantages of simple structure, smooth exhaust and stable work. It is especially suitable for engine systems with high requirements on work efficiency and high reliability.

Claims

Rights request

1. A muffler for an engine that enhances back pressure and leakage, characterized in that it includes an outer tube; an inner tube that axially passes through the outer tube; an inner wall at both ends of the outer tube and an outer wall of the inner tube The interior is closed, there are multiple small holes in the inner tube wall, and there are multiple shrink tubes at an appropriate distance inside the inner tube. The cross-sections of these shrink tubes are set from large to small in order according to the exhaust direction so that The exhaust gas has an acceleration effect when it is exhausted; a plurality of baffles are arranged between the inner wall of the outer pipe and the outer wall of the inner pipe, and the baffle has a plurality of small holes for the exhaust gas to pass from one end of the inner pipe to each Shrink the tube to accelerate the airflow and cooperate with the exhaust valve operation of the engine. After the exhaust valve is opened, a large amount of back pressure is generated in the time before the piston reaches the bottom dead center. The expansion stroke of the engine can be fully operated, and the internal resistance is reduced when the piston enters the exhaust stroke to achieve the effect of sufficient exhaust.