Engine guided scavenging intake and exhaust valve

Abstract

The utility model provides a kind of engine guiding scavenging type intake valve and exhaust valve, solved the problem that traditional overhead valve type engine intake valve is difficult to efficiently clean exhaust gas under two-stroke working mode to extend into cylinder inner cavity, technical scheme is: including being arranged in engine overhead valve mechanism intake valve body or exhaust valve body, intake valve stem has the gas guide pipe of being packaged with support and moving with intake valve stem, gas guide pipe is close to intake valve head, and front end outlet is left between the gas guide pipe front end and intake valve head;There is the gas guide pipe of being packaged with support and moving with exhaust valve stem, gas guide pipe is close to exhaust valve head, and front end outlet is left between the gas guide pipe front end and exhaust valve head.It is through to intake guiding scavenging, guiding exhaust gas, improve combustion efficiency and emission performance, greatly improve the scavenging efficiency, and further improve engine working efficiency.

Description

Technical Field

[0001] This utility model relates to the field of internal combustion engine technology, and in particular to an engine-guided scavenging intake valve and exhaust valve, which are applicable to the valve train mechanism of an overhead valve type two-stroke engine. Background Technology

[0002] Internal combustion engines have a history of over 150 years since their practical application. Based on their working cycle, they are mainly divided into two-stroke engines and four-stroke engines. Traditional two-stroke engines use side-mounted valves for intake and exhaust, with one revolution of the crankshaft completing one power stroke. The piston completes the four processes of intake, compression, power, and exhaust through two strokes. The exhaust gas is pushed out by a fresh air-fuel mixture. Due to limitations in its structure, valve train, and scavenging process, there is a lot of residual exhaust gas, and unburned oil is discharged with the exhaust, resulting in low combustion efficiency, poor emissions, severe exhaust pollution, and high fuel consumption. The intake valve is a crucial component of the engine's valve train. Four-stroke engines typically use an overhead valve train, including a valve assembly and valve train located in the cylinder block and cylinder head. The valve assembly includes intake and exhaust valves. The intake valve mainly consists of the valve stem and valve head, while the valve train mainly includes a cam mechanism and valve springs for driving the valve extension and retraction. A four-stroke engine operates by rotating the crankshaft twice to complete one power stroke. The piston completes the four processes of intake, compression, power, and exhaust through four strokes. While it addresses exhaust emissions through separate lubrication, its operating method has significant drawbacks. The crankshaft needs to rotate twice to complete one power stroke, and the valve train must coordinate with the crankshaft to complete all four processes. This results in substantial stroke losses and unnecessary mechanical wear, consuming additional energy and time, leading to fuel waste and mechanical damage. Furthermore, the long power stroke cycle results in a large engine size and increased manufacturing costs. Therefore, there is an urgent need to develop new engine structures and valve designs to solve these technical problems.

[0003] Patent document CN107420195B discloses a two-stroke engine based on a four-stroke engine structure. Its improved valve train structure features a longitudinally positioned intake manifold and a streamlined intake valve head. The valve seat ring within the intake manifold has a narrow throat, and the intake valve head seals the area below the valve seat ring. During operation, the transmission ratio between the crankshaft and the intake / exhaust camshafts is 1:1. Each reciprocating motion of the piston within the cylinder drives the crankshaft-connecting rod mechanism to rotate one revolution, which in turn drives the intake and exhaust valves to open once each via the camshaft transmission mechanism, forming a two-stroke working cycle. When the intake valve opens, the exhaust valve also opens. Fresh gas enters the cylinder combustion chamber through the gap between the narrow throat of the intake manifold and the intake valve head. The streamlined surface of the intake valve head guides the airflow to complete the scavenging process, increasing the effect of expelling exhaust gases after combustion in the cylinder. The intake valve remains within the intake manifold at all times. Compared to traditional disc-shaped valve heads, it improves the airflow guidance effect. However, its intake valve head is still located at the intake manifold opening. Moreover, due to the narrow throat of the intake manifold, it greatly hinders the entry of fresh gas, reduces the gas flow, and severely limits the guiding gas function. In particular, it cannot extend into the piston cylinder and deeper areas to guide gas and scavenge exhaust gases. Therefore, this intake valve cannot efficiently scavenge exhaust gases simultaneously during the intake process after extending into the cylinder cavity, and cannot further improve combustion efficiency and emission performance. Utility Model Content

[0004] The purpose of this invention is to provide an engine-guided scavenging intake valve, which solves the problem that traditional overhead valves in engines are difficult to efficiently scavenge exhaust gases when they extend into the cylinder cavity during a two-stroke operation. By guiding the intake air to scavenge the exhaust gases, it improves combustion efficiency and emission performance.

[0005] The technical solution adopted by this utility model is as follows: the engine guide scavenging intake valve includes an intake valve body disposed in the intake channel of the top-mounted valve distribution mechanism of the engine. The intake valve body includes an intake valve stem with an intake valve head. The key technical point is that the intake valve stem has an air guide tube that moves with the intake valve stem through a bracket. The air guide tube is close to the intake valve head, and a front air outlet is left between the front end of the air guide tube and the intake valve head.

[0006] The support for the air duct is a connecting rod or connecting rib plate located between the inner wall of the air duct and the intake valve rod in the middle of the air duct.

[0007] The support for the air duct includes a front support and a rear support respectively disposed at the two ends of the air duct. The front support is a connecting rod or connecting rib between the air outlet at the front end of the air duct and the air intake valve stem or the air intake valve head; the rear support is a connecting rod or connecting rib between the rear end of the air duct and the air intake valve stem.

[0008] The air outlet at the front end of the air duct is set as an angled port facing away from the exhaust valve.

[0009] The air duct wall is provided with multiple air outlets.

[0010] The support for the air duct is a connecting rib, and the upper and lower edges of the connecting rib are concave curved surfaces.

[0011] The engine exhaust valve includes an exhaust valve body disposed in the exhaust passage of the top-mounted valve train of the engine. The exhaust valve body includes an exhaust valve stem with an exhaust valve head. The key technical point is that the exhaust valve stem has an air guide pipe that moves with the exhaust valve stem via a bracket. The air guide pipe is close to the exhaust valve head, and a front air outlet is left between the front end of the air guide pipe and the exhaust valve head.

[0012] The support for the air duct is a connecting rod or connecting rib plate installed between the inner wall of the air duct and the exhaust valve rod in the middle of the air duct.

[0013] The support for the air duct includes a front support and a rear support respectively disposed at the two ends of the air duct. The front support is a connecting rod or connecting rib between the front end of the air duct and the exhaust valve stem or the exhaust valve head; the rear support is a connecting rod or connecting rib between the rear end of the air duct and the exhaust valve stem.

[0014] The support for the air duct is a connecting rib, and the upper and lower edges of the connecting rib are concave curved surfaces.

[0015] The advantages and beneficial effects of this utility model are as follows: Because this engine-guided scavenging intake valve uses a guide pipe that moves with the intake valve stem within the fixed assembly of the intake valve stem, and an outlet is left between the front end of the guide pipe and the intake valve head, when used in the valve train mechanism of an overhead valve, the intake valve head can be pushed into the cylinder cavity by increasing the length of the intake cam lobe of the valve train mechanism. The intake cam can control the guide pipe's extension into the guide area formed within the engine cylinder cavity. Therefore, the guide pipe can guide fresh air entering the cylinder into the guide area, achieving deep scavenging of the exhaust gas after combustion within the cylinder, opening the exhaust valve, and fully scavenging the exhaust gas. This avoids the problem of traditional intake valves only scavenging exhaust gas at the valve opening and having low scavenging efficiency. The problem is that because the exhaust valve of this engine uses a guide pipe that moves with the exhaust valve stem in the exhaust valve stem fixing assembly, and there is a front port between the front end of the guide pipe and the exhaust valve head, when used in the valve train of an engine with overhead valves, the length of the exhaust cam lobe can be increased by using the valve train to push the exhaust valve head into the cylinder cavity. The exhaust cam can control the exhaust valve guide pipe to extend into the guide area formed by the extension into the engine cylinder cavity, guiding the exhaust gas in the engine cylinder to be discharged and drawn into the guide pipe. This achieves deep intake of exhaust gas into the engine combustion chamber and near the top of the engine piston, thoroughly scavenging the exhaust gas. By guiding the exhaust gas to scaveng, combustion efficiency and emission performance are improved, greatly improving scavenging efficiency, and thus improving engine working efficiency. Attached Figure Description

[0016] The present invention will be further described below with reference to the accompanying drawings.

[0017] Figure 1 This is a schematic diagram of the first intake valve structure according to Embodiment 1 of this utility model;

[0018] Figure 2 yes Figure 1 A schematic diagram of the longitudinal sectional view of the structure;

[0019] Figure 3 This is a schematic diagram of the second intake valve structure according to Embodiment 1 of this utility model;

[0020] Figure 4 This is a schematic diagram of the third intake valve structure in Embodiment 1 of this utility model;

[0021] Figure 5 This is a schematic diagram of the fourth intake valve structure in Embodiment 1 of this utility model;

[0022] Figure 6 This is a schematic diagram of the fifth intake valve structure according to Embodiment 1 of this utility model;

[0023] Figure 7This is a schematic diagram of the sixth intake valve structure according to Embodiment 1 of this utility model;

[0024] Figure 8 This is a schematic diagram of the structure of an embodiment of the present invention installed in an overhead valve engine;

[0025] Figure 9 This is a structural schematic diagram of the second working state of Embodiment 1 of this utility model;

[0026] Figure 10 This is a structural schematic diagram of the third working state of Embodiment 1 of this utility model;

[0027] Figure 11 This is a structural schematic diagram of the fourth working state of Embodiment 1 of this utility model;

[0028] Figure 12 This is a structural schematic diagram of the fifth working state of Embodiment 1 of this utility model;

[0029] Figure 13 This is a schematic diagram of the fifth intake valve working state structure in Embodiment 1 of this utility model;

[0030] Figure 14 This is a schematic diagram of the gas distribution phase in Embodiment 1 of this utility model;

[0031] Figure 15 This is a schematic diagram of the first intake valve structure in Embodiment 2 of this utility model;

[0032] Figure 16 yes Figure 15 A schematic diagram of the longitudinal sectional view of the structure;

[0033] Figure 17 This is a schematic diagram of the second intake valve structure according to Embodiment 2 of this utility model;

[0034] Figure 18 This is a schematic diagram of the third intake valve structure in Embodiment 2 of this utility model;

[0035] Figure 19 This is a schematic diagram of the fourth intake valve structure in Embodiment 2 of this utility model;

[0036] Figure 20 This is a schematic diagram of the structure of the present invention installed on the engine according to Embodiment 2;

[0037] Figure 21 This is a structural schematic diagram of the second working state of Embodiment 2 of this utility model;

[0038] Figure 22 This is a structural schematic diagram of the second embodiment of the present invention in its working state three.

[0039] Figure 23 This is a structural schematic diagram of the second embodiment of this utility model in its working state four.

[0040] Figure 24 This is a structural schematic diagram of the working state five of Embodiment 2 of this utility model;

[0041] Figure 25 This is a schematic diagram of the gas distribution phase during the operation of Embodiment 2 of this utility model.

[0042] The numbers in the diagram are explained as follows: 1. Cylinder head, 2. Intake passage, 3. Intake valve, 4. Cylinder block, 5. Piston, 6. Crankshaft, 7. Crankcase, 8. Intake valve cam, 9. Intake valve spring, 10. Exhaust valve cam, 11. Exhaust valve spring, 12. Exhaust valve, 13. Exhaust port, 14. Fuel injector, 15. Air guide area, 16. Exhaust passage, 17. Straight section exhaust port, 21. Straight section intake port, 31. Intake valve stem, 32. Air guide pipe, 33. Intake valve head, 34. Front exhaust port, 35. Rear port, 36. Bracket, 37. Exhaust port, 81. Protrusion, 101. Exhaust valve cam protrusion, 121. Exhaust valve stem, 122. Exhaust valve head, 123. Front port. Detailed Implementation

[0043] according to Figure 1-25 This utility model provides an engine valve that can be used as both an intake valve and an exhaust valve. Example 1 is shown below. Figure 1 and Figure 2 As shown, an engine-guided scavenging intake valve includes an intake valve stem 31 with an intake valve head 33. The intake valve stem 31 is equipped with a guide pipe 32 that moves with the intake valve stem 31 via a bracket 36. The guide pipe 32 is located near the intake valve head 33, and a front outlet 34 is provided between the front end of the guide pipe and the intake valve head. Figure 8As shown, the engine-guided scavenging intake valve is applied to the valve train of an overhead valve engine. The valve train includes an overhead valve intake valve train assembly and an exhaust valve train assembly mounted on the cylinder head 1 of the engine block. The intake valve train assembly includes an intake valve stem 31 with an intake valve head 33 mounted in the intake passage 2. An intake valve cam 8 and an intake valve spring 9 are connected to the rear of the intake valve stem to push the intake valve to open and close the intake port 13. The engine block assembly includes: The cylinder block 4, cylinder head 1, and crankcase 7, etc., have an overhead valve system. The cylinder head 1 is equipped with an intake valve 3 driven by an intake valve cam 8 and an intake valve spring 9. The intake valve has a straight intake hole 21 in front of it that connects the intake passage 2 and the intake port. The intake valve head 33 can block and open the intake port. The crankshaft 6 of the crankshaft connecting rod mechanism drives the camshaft and crankshaft to rotate synchronously through a timing gear, chain, or timing belt, and operates in a two-stroke working mode. The improvement of the engine-guided scavenging intake valve lies in the following: A guide pipe 32 is fixedly mounted on the front part of the intake valve stem 31 of the valve train via a bracket 36. The guide pipe is movably positioned within the straight section of the intake port 21 that connects the intake passage 2 and the intake inlet. The guide pipe can move with the intake valve stem. A clearance fit can be formed between the inner wall of the straight section of the intake port 21 and the guide pipe 32, which reduces the loss of fresh air through the gap between them and reduces or prevents contact between them, thus reducing the frictional resistance generated between the valve and the guide pipe due to the up-and-down movement of the valve. Figure 1 and Figure 2As shown, a disc-shaped intake valve head 33 is provided at the front end of the intake valve stem 31 of the intake valve. A certain distance is left between the front end of the air guide pipe and the intake valve head to form a front outlet 34. The rear end 35 of the air guide pipe is connected to the intake channel 2, so that the inner cavity of the air guide pipe forms a passage connecting the intake channel and the intake port. In order to enable the intake valve head to enter the cylinder body cavity, the intake cam 8 of the valve train can be provided with an intake cam protrusion 81 that pushes the front end of the air guide pipe 32 of the intake valve into the inner cavity of the cylinder body 4. The intake cam 8 of this valve train has a larger cam protrusion than conventional intake cams, and the exhaust valve 12 is a traditional exhaust valve stem with an exhaust valve head. The diameter of the intake cam 8 and the length of the intake valve stem are both larger than those of the exhaust cam. The intake valve spring 9 is thicker than the exhaust valve spring 11, which results in a longer stroke to push the intake valve stem and head. This allows the intake valve head to extend into the air guide area 15 between the upper part of the cylinder cavity and the center position or near the bottom dead center of the piston. The length of the intake cam protrusion and the depth of the intake valve head extending into the cylinder cavity can be matched by the intake cam protrusion. Therefore, the fresh air entering the cylinder can be guided into the air guide area by the air guide pipe, achieving the purpose of blowing exhaust gas deep into the engine cylinder. This is different from the traditional engine intake valve working method, which only makes the valve head disengage from the valve door to form an open state. The engine's intake passage is connected to the exhaust pipe of an external turbocharger or supercharger system (i.e., a Roots blower), or it can be connected to the exhaust pipes of both the turbocharger and supercharger systems. The purpose is to allow pressurized fresh air to enter the engine's combustion chamber through the intake valve's duct.

[0044] As a further improvement, such as Figure 2 As shown, the support 36 of the air duct 32 can be a connecting rod or connecting rib between the inner wall of the air duct and the intake valve stem 31 in the middle of the air duct, so that the air duct is stably connected to the intake valve stem. The connecting rib can be in the shape of a longitudinal thin sheet, which can reduce air resistance. The air duct and the support can be connected and fixed by welding to the intake valve stem or by an integral structure.

[0045] As a further improvement, such as Figure 3 As shown, the support 36 of the air duct 32 can be constructed by including a front support and a rear support respectively disposed at both ends of the air duct. The front support is a connecting rod or connecting rib near the air outlet 34 at the front end of the air duct and the intake valve stem 31, and the rear support is a connecting rod or connecting rib near the rear end 35 of the air duct and the intake valve stem 31. This structure can securely connect the air duct to the intake valve and reduce obstruction of the inner cavity of the air duct. Figure 4 As shown, the front bracket can also use a connecting rod or connecting rib plate near the air outlet at the front end of the air duct and the valve head to increase stability. The connecting rib plate can be in the shape of a longitudinal thin sheet, which can reduce air resistance.

[0046] As a further improvement, such as Figure 6 As shown, the support for the air duct is a connecting stiffener. The upper and lower edges of the connecting stiffener are concave curved surfaces. The connecting stiffener is located in the middle of the inner wall of the air duct. Two to five connecting stiffeners can be evenly distributed around the exhaust valve rod.

[0047] As a further improvement, such as Figure 5 As shown, the front outlet 34 of the air guide pipe 32 can be configured as an angled port facing away from the exhaust valve. The lower outlet of the air guide pipe is inclined to the direction of the intake valve head, so that when the fresh gas is ejected from the front outlet, it is directed towards the inner wall of the cylinder body away from the exhaust valve. This allows most of the gas entering the cylinder body to be sprayed towards the cylinder wall and the top of the piston. The gas rebounds from the inner wall of the cylinder body and the top of the piston to clean up the combusted exhaust gas, thus better removing the combusted exhaust gas from the cylinder body and increasing the efficiency of exhaust gas cleaning. To prevent the air guide pipe of the intake valve from changing the direction of air blowing due to rotation, the valve guide rod of the intake valve can be made into an ellipse, or an anti-rotation locating pin can be made on the valve guide rod and the air guide pipe of the valve, or the intake guide rod hole in the cylinder head can be used to limit and prevent rotation.

[0048] As a further improvement, such as Figure 7 As shown, multiple air outlets 37 can be provided on the wall of the air guide pipe 32, so that gas can be continuously injected and exhaust gas can be swept out as the air guide pipe extends into the cylinder body from the air inlet.

[0049] Working methods and principles: such as Figures 8 to 13 As shown, the power stroke, exhaust, intake, and compression processes of a two-stroke diesel engine using this intake valve are sequentially illustrated, along with its operating status at each stage. The engine used in this invention is a two-stroke engine, and its valve train differs from that of traditional engines. In a traditional four-stroke engine, the intake and exhaust valves open and close only once every two crankshaft revolutions. In contrast, the valve train of this engine opens and closes once for each crankshaft revolution. During operation, the intake valve employs the engine-guided scavenging type of the embodiment described in Example 1; the exhaust valve is a traditional exhaust valve stem with an exhaust valve head, without a guide pipe.

[0050] The work process includes the following steps: Figure 8In the initial working state, that is, at the beginning of the power stroke, both intake valve 3 and exhaust valve 12 are closed, piston 5 is close to the top dead center position, and the protrusions of intake valve cam 8 and exhaust valve cam 10 rotate away from the spring position; then the crankshaft drives the camshaft to rotate counterclockwise synchronously through the timing gear, chain or timing belt; during the cycle, this process is also the power stroke, pushing the piston to move downward from the top dead center, and intake valve cam 8, exhaust valve cam 10 and crankshaft 6 rotate counterclockwise.

[0051] like Figure 9 As shown, the exhaust valve cam 10 is set to push the exhaust valve spring 11 to open the exhaust valve 12 before the piston 5 moves to the bottom dead center, releasing the pressure in the combustion chamber. At this time, the intake valve remains closed, so that the exhaust gas after combustion can be discharged from the exhaust port 13.

[0052] like Figure 10 As shown, before the piston 5 continues to move to the bottom dead center, the intake valve cam 8 rotates to the open intake valve state. At this time, the intake valve has just opened and begins to send fresh air into the cylinder to carry out the intake process.

[0053] like Figure 11 As shown, the process of intake and exhaust occurs simultaneously. The piston continues to move to the bottom dead center and then gradually moves upward after passing the bottom dead center. During this process, the intake valve cam 8 pushes the intake valve head 33 into the cylinder cavity, so that the intake valve reaches the maximum opening depth. This allows the intake duct to extend into the cylinder, and the fresh air entering the cylinder can be guided into the air guide area 15 through the air guide pipe to achieve the purpose of sweeping exhaust gas deep into the cylinder. The pressurized fresh air is sent to the bottom of the cylinder and the combusted exhaust gas is discharged from the cylinder. After reaching the maximum depth, it retracts upward, so that the movement of the intake valve head does not interfere with or collide with the movement of the piston.

[0054] like Figure 12 As shown, this illustrates the compression process of the engine piston. After scavenging, exhaust valve 12 closes prematurely, and the intake valve 3 guide gradually retracts, closing the intake valve. Alternatively, the exhaust and intake valves can be closed simultaneously. This position coincides with the end of the piston's fresh air exchange, the closing position of both the intake and exhaust valves, and the start of the compression stroke. Piston 7 then continues to move upwards to continue the air compression process. The piston continues to move upwards until it reaches top dead center, completing the compression stroke.

[0055] like Figure 1As shown, once the engine reaches its initial operating position, the air-fuel mixture is ignited, pushing the piston to perform work. With the piston near top dead center, fuel injector 14 operates, injecting atomized diesel fuel into the combustion chamber. Alternatively, gasoline or other combustible gases can be injected into the engine cylinder after the intake and exhaust valves are closed. Adding a spark plug transforms it into a gasoline engine. Alternatively, the engine can burn natural gas or liquefied petroleum gas (LPG). After completing one working cycle, the engine enters the next power stroke.

[0056] like Figure 13 The diagram shown is a schematic of the fifth intake valve working state structure in Embodiment 1 of this utility model. The intake valve 3 uses the front outlet 34 of the air guide pipe 32 as an angled port. The front outlet of the air guide pipe extends into the air guide area between the upper part of the cylinder body cavity and near the bottom dead center of the piston for scavenging. The closer the front outlet of the air guide pipe is to the bottom dead center of the piston, the better the scavenging effect. The optimal position is to extend the front outlet of the air guide pipe into the air guide area between the bottom dead center of the piston and the center of the cylinder body cavity (making the air guide pipe close to the top of the piston). The air guide pipe wall is provided with multiple air outlets 37, so that when some fresh gas is ejected from the front outlet, it is directed towards the cylinder body wall away from the exhaust valve. The gas rebounds from the cylinder body wall to scavenge the exhaust gas, increasing the efficiency of exhaust gas scavenging.

[0057] Figure 14 The diagram shown illustrates the valve timing in use according to Embodiment 1 of this invention. The crankshaft, intake camshaft, and exhaust camshaft rotate counter-clockwise along the coordinate axis. 'a' represents the angular range of the exhaust camshaft from opening to closing, 'b' represents the angular range of the intake camshaft from opening to closing, 'c' represents the angular range of the piston crankshaft's power stroke, and 'd' represents the angular range of the piston crankshaft's compression stroke. The intake valve can open at a position of 28 to 35 degrees before the piston reaches bottom dead center, and the exhaust valve can open at a position of 30 to 60 degrees before the intake valve opens. The intake and exhaust valves can close simultaneously or with a delay. The angle range of the protrusions on the intake and exhaust valve cams can be adjusted, reducing the engine's intake and exhaust strokes.

[0058] This utility model's intake valve is mounted on the engine, and is particularly suitable for two-stroke engines. By guiding and scavenging the intake air, it can achieve one power stroke per crankshaft rotation. Therefore, it reduces manufacturing costs, increases engine power, and allows the engine to achieve power output comparable to large-displacement, multi-cylinder engines with a smaller displacement and number of cylinders. It also reduces engine fuel consumption and maintenance costs. It shrinks engine size and weight, lowering production and maintenance costs, while also reducing the size of the engine support frame. Because it eliminates separate intake and exhaust strokes, it is more fuel-efficient. It significantly reduces engine stroke losses, minimizing fuel consumption and mechanical wear caused by intake and compression strokes, resulting in higher thermal efficiency and greater energy saving and environmental friendliness. This utility model is particularly suitable for automotive engines with longer piston formations.

[0059] Example 2: An engine exhaust valve, such as Figure 15 and Figure 16 As shown, the exhaust valve 13 body of the engine exhaust valve has the same structure as the intake valve 3 in Embodiment 1. The exhaust valve stem 121 is fixedly fitted with an air guide pipe 32 by a bracket 36. The air guide pipe can move with the intake valve stem. The exhaust valve stem 121 of the exhaust valve 13 is provided with a disc-shaped exhaust valve head 122 at the front end. A certain distance is left between the front end of the air guide pipe and the exhaust valve head to form a front port 123.

[0060] The engine exhaust valve can be installed in the engine used in Embodiment 1, such as... Figure 20As shown, the engine's valve train includes an overhead valve exhaust valve train and an intake valve train, both mounted on the cylinder head 1 of the engine combustion chamber. The engine block assembly includes the engine combustion chamber 4, cylinder head 1, and crankcase 7. The crankshaft 6 of the crankshaft connecting rod mechanism drives the camshaft to rotate synchronously with the crankshaft via timing gears, chains, or timing belts, operating in a two-stroke mode. The valve train uses overhead valves. An exhaust valve 12, driven by an exhaust valve cam 10 and an exhaust valve spring 11, is located on the cylinder head 1. A straight exhaust port 17, connecting the exhaust passage 16 and the exhaust port 13, is located at the front of the exhaust valve. The exhaust valve head 122 can block and open the exhaust port 13. The guide pipe can move with the exhaust valve stem. A clearance fit can be formed between the inner wall of the straight exhaust port 17 and the guide pipe 32 to reduce or prevent contact between them, thus reducing frictional resistance between the valve and the guide pipe due to the up-and-down movement of the valve. The rear end of the air guide pipe is connected to the exhaust passage 16, so that the inner cavity of the air guide pipe forms a passage connecting the exhaust passage and the exhaust port. The exhaust cam 10 of the valve train may be provided with an exhaust cam protrusion 101 that pushes the front end of the air guide pipe 32 into the inner cavity of the engine cylinder block 4. The intake valve is a traditional intake valve stem with an intake valve head. The exhaust cam 10 of the exhaust valve 12 has a larger protrusion than the intake cam of a conventional intake valve. The diameter and length of the exhaust cam 10 are both greater than those of the intake cam. The exhaust valve spring 9 is thicker than the intake valve spring, resulting in a longer stroke to push the exhaust valve stem and head. This allows the exhaust valve head to extend into the upper part to the center of the engine combustion chamber or into the guide air area 15 near the bottom dead center of the piston. The length of the exhaust cam protrusion and the depth of the exhaust valve head extending into the engine combustion chamber can be matched by the exhaust cam protrusion. Therefore, the exhaust gas in the engine combustion chamber and near the top of the engine piston can be drawn in through the guide air pipe, fully scavenging the exhaust gas. This avoids the problem of low scavenging efficiency in traditional exhaust valves, which can only draw in and expel exhaust gas at the valve opening. This is different from the traditional exhaust valve operation method, which only allows the valve head to disengage from the valve opening to form an open state.

[0061] As a further improvement, the engine exhaust valve can adopt the structural shape of the intake valve in Embodiment 1, such as... Figure 16 As shown, the support 36 of the air guide pipe 32 can be a connecting rod or connecting rib between the inner wall of the air guide pipe near both ends or in the middle and the exhaust valve stem 121, so that the air guide pipe is stably connected to the exhaust valve stem. The connecting rib can be in the shape of a longitudinal thin sheet, which can reduce air resistance. The air guide pipe and the support can be connected and fixed by welding to the exhaust valve stem or by an integral structure.

[0062] As a further improvement, such as Figure 17 and Figure 18As shown, the support 36 of the air duct 32 can be constructed by including a front support and a rear support respectively disposed at both ends of the air duct. The front support is a connecting rod or connecting rib near the front end 123 of the air duct and the exhaust valve stem 121, and the rear support is a connecting rod or connecting rib near the rear end of the air duct and the exhaust valve stem 121. This structure can securely connect the air duct to the exhaust valve and reduce obstruction of the air duct's internal passage. The connecting rib can be in the shape of a longitudinal thin sheet to reduce air resistance.

[0063] As a further improvement, such as Figure 19 As shown, the support for the air duct is a connecting stiffener. The upper and lower edges of the connecting stiffener are concave curved surfaces. The connecting stiffener is located in the middle of the inner wall of the air duct. Two to five connecting stiffeners can be evenly distributed around the exhaust valve rod.

[0064] Working methods and principles: such as Figures 20 to 24 As shown, the power stroke, exhaust, intake, and compression processes of a two-stroke diesel engine using this exhaust valve are sequentially illustrated, along with its operating status at each stage. This utility model engine is a two-stroke engine, and its valve train differs from that of traditional engines. In a traditional four-stroke engine, the exhaust valve and its opening and closing occur only once every two crankshaft revolutions. In contrast, this engine's valve train opens and closes once per crankshaft revolution. During operation, the exhaust valve uses the type described in Example 2; the intake valve is a traditional exhaust valve stem with an exhaust valve head, without a guide pipe.

[0065] The work process includes the following steps: Figure 20 In the initial working state, that is, at the beginning of the power stroke, the exhaust valve 12 and the intake valve 3 are both closed, the piston 5 is close to the top dead center position, and the convex parts of the exhaust valve cam 10 and the intake valve cam rotate away from the spring position; then the crankshaft drives the camshaft to rotate counterclockwise synchronously through the timing gear, chain or timing belt; during the cycle, this process is also the power stroke, which pushes the piston to move downward from the top dead center, and the exhaust valve cam 10, the intake valve cam 8 and the crankshaft 6 rotate counterclockwise.

[0066] like Figure 21 As shown, the exhaust valve cam 10 is set to push the exhaust valve spring 11 to open the exhaust valve 12 before the piston 5 moves to the bottom dead center, releasing the pressure in the combustion chamber. At this time, the intake valve remains closed, so that the exhaust gas in the upper part of the combustion chamber after combustion can be discharged from the exhaust port 13.

[0067] like Figure 22As shown, before the piston 5 continues to move to the bottom dead center, the intake valve cam rotates to the open intake valve state, and begins to send fresh air into the engine combustion chamber for the intake process; at this time, the exhaust valve cam 10 pushes the exhaust valve head 122 into the engine combustion chamber cavity, so that the exhaust valve reaches the maximum opening depth, and the exhaust duct extends into the engine combustion chamber of the cylinder block. It can use the duct to guide the exhaust gas from the middle of the combustion chamber to the piston top duct area 15 into the duct, and discharge the exhaust gas that has been burned at the bottom of the engine combustion chamber out of the cylinder body, so as to achieve the purpose of sweeping exhaust gas deep into the engine combustion chamber. After reaching the maximum depth, it retracts upward, so that the movement of the exhaust valve head does not interfere with or collide with the movement of the piston.

[0068] like Figure 23 As shown, after the piston continues to move to the bottom dead center, it gradually moves upward. During this process, the intake valve opens, and after scavenging is completed, the exhaust valve 12 closes prematurely, and the exhaust valve guide pipe 23 gradually retracts, closing the exhaust valve. Alternatively, the exhaust valve and exhaust valve can be set to close simultaneously; this position coincides with the end of the piston's fresh air exchange.

[0069] like Figure 24 The diagram shows the compression process of the engine piston, with the exhaust valve at its closed position, marking the beginning of the compression stroke. Piston 5 continues to move upwards to compress the air, reaching top dead center to complete the compression stroke.

[0070] like Figure 20 As shown, once the engine reaches its initial working position, the air-fuel mixture is ignited, pushing the piston to perform work. With the piston near top dead center, fuel injector 14 operates, injecting atomized diesel fuel into the combustion chamber. Alternatively, gasoline or other combustible gases can be injected into the engine cylinder after the exhaust valve is closed. Adding a spark plug transforms it into a gasoline engine. Alternatively, the engine can burn natural gas or liquefied petroleum gas (LPG). After completing one working cycle, the engine enters the next power stroke.

[0071] like Figure 25 The diagram shown illustrates the valve timing in use during embodiment two of this invention. The crankshaft, intake camshaft, and exhaust camshaft rotate counter-clockwise along the coordinate axis. 'a' represents the angular range of the exhaust camshaft from opening to closing, 'b' represents the angular range of the intake camshaft from opening to closing, 'c' represents the angular range of the piston crankshaft's power stroke, and 'd' represents the angular range of the piston crankshaft's compression stroke. The intake valve can open at a position 28 to 35 degrees before the piston reaches bottom dead center, and the exhaust valve can open at a position 30 to 60 degrees before the intake valve opens. The intake and exhaust valves can close simultaneously or with a delay. The angle range of the protrusions on the intake and exhaust valve cams can be adjusted, reducing the engine's intake and exhaust strokes.

[0072] This invention utilizes separate intake and exhaust valves on the engine, preventing simultaneous use. It is particularly suitable for two-stroke engines, guiding exhaust gas through scavenging to ensure power output once per crankshaft revolution. By using a scavenging pipe to guide exhaust gas from the cylinder into the intake pipe, it effectively draws in exhaust gas from the combustion chamber and near the piston top, thoroughly scavenging the exhaust. This reduces manufacturing costs, increases engine power, and allows the engine to achieve power output comparable to large-displacement, multi-cylinder engines with a smaller displacement and fewer cylinders. It also reduces fuel consumption and maintenance costs. The design reduces engine size and weight, lowering production and maintenance costs, while also reducing the size of the engine support frame. Eliminating separate intake and exhaust strokes further improves fuel efficiency. It significantly reduces engine stroke losses, minimizing fuel consumption and mechanical wear caused by intake and compression strokes, resulting in higher thermal efficiency and greater energy savings and environmental friendliness. This invention is especially suitable for automotive engines with longer piston formations.

[0073] In summary, the purpose of this utility model has been achieved.

Claims

1. An engine-guided scavenging intake valve, comprising an intake valve body disposed in the intake passage of an engine overhead valve train, the intake valve body including an intake valve stem with an intake valve head, characterized in that: The intake valve stem has an air guide tube that moves with the intake valve stem via a bracket. The air guide tube is close to the intake valve head, and a front air outlet is left between the front end of the air guide tube and the intake valve head.

2. The engine-guided scavenging intake valve according to claim 1, characterized in that: The support for the air duct is a connecting rod or connecting rib plate located between the inner wall of the air duct and the intake valve rod in the middle of the air duct.

3. The engine-guided scavenging intake valve according to claim 1, characterized in that: The support for the air duct includes a front support and a rear support respectively disposed at the two ends of the air duct. The front support is a connecting rod or connecting rib between the air outlet at the front end of the air duct and the air intake valve stem or the air intake valve head; the rear support is a connecting rod or connecting rib between the rear end of the air duct and the air intake valve stem.

4. The engine-guided scavenging intake valve according to claim 1, characterized in that: The air outlet at the front end of the air duct is set as an angled port facing away from the exhaust valve.

5. The engine-guided scavenging intake valve according to claim 1, characterized in that: The air duct wall is provided with multiple air outlets.

6. The engine-guided scavenging intake valve according to claim 1, characterized in that: The support for the air duct is a connecting rib, and the upper and lower edges of the connecting rib are concave curved surfaces.

7. An engine exhaust valve, comprising an exhaust valve body disposed in the exhaust passage of an engine overhead valve train, the exhaust valve body including an exhaust valve stem with an exhaust valve head, characterized in that: The exhaust valve stem has an air guide pipe that moves with the exhaust valve stem via a bracket set. The air guide pipe is close to the exhaust valve head, and a front air outlet is left between the front end of the air guide pipe and the exhaust valve head.

8. The engine exhaust valve according to claim 7, characterized in that: The support for the air duct is a connecting rod or connecting rib plate installed between the inner wall of the air duct and the exhaust valve rod in the middle of the air duct.

9. The engine exhaust valve according to claim 7, characterized in that: The support for the air duct includes a front support and a rear support respectively disposed at the two ends of the air duct. The front support is a connecting rod or connecting rib between the front end of the air duct and the exhaust valve stem or the exhaust valve head; the rear support is a connecting rod or connecting rib between the rear end of the air duct and the exhaust valve stem.

10. The engine exhaust valve according to claim 7, characterized in that: The support for the air duct is a connecting rib, and the upper and lower edges of the connecting rib are concave curved surfaces.

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