An externally compressed single cycle work engine

Abstract

This invention discloses an externally mounted, single-cycle internal combustion engine, belonging to the field of internal combustion engine power technology. This invention pioneers a thermodynamic cycle structure combining external supercharging and accumulating pressure, significantly shortened intake strokes, and single crankshaft cycle power generation. It completely eliminates the traditional in-cylinder intake and compression strokes, relying on an external supercharging system to establish combustion pressure. The high-pressure mixture only needs to be injected into the combustion chamber, significantly reducing the crankshaft angle required for intake. Within one crankshaft rotation, the intake, ignition, and exhaust processes are fully distributed, achieving one effective power stroke per crankshaft rotation. Based on a four-stroke independent valve structure, it achieves two-stroke level power density, overcoming the technical shortcomings of low four-stroke power frequency and poor two-stroke emissions, reducing engine mechanical losses, and adapting to various external supercharging structures. It possesses high innovation and industrial application value.

Description

1. Technical Field

[0001] This invention belongs to the field of reciprocating piston internal combustion engine power technology, specifically involving a novel internal combustion engine thermodynamic cycle structure that eliminates the in-cylinder compression stroke, adopts external integral supercharging and accumulating pressure, significantly shortens the intake space, and completes power output in a single crankshaft rotation. It is applicable to power devices such as automobiles, motorcycles, unmanned aerial vehicles, marine power, construction machinery, and generator sets. 2. Background Technology

[0002] The mainstream mature thermodynamic cycles of existing reciprocating internal combustion engines are divided into four-stroke cycles and two-stroke cycles, and there is an inherent structural contradiction between the two.

[0003] Traditional four-stroke engines require one crankshaft rotation to complete the intake and compression strokes, and a total of two crankshaft rotations to complete one power stroke. During the intake phase, gas is drawn in using the piston stroke, and the gas needs to fill the entire cylinder volume formed by the piston's movement. The intake process occupies a large crankshaft angle, so it is impossible to arrange the entire working process within a single crankshaft rotation angle, resulting in low power density, high mechanical losses, and slow power response. The compression process relies on piston mechanical extrusion, and friction losses account for a high proportion of the overall engine losses, resulting in a clear upper limit on power density and thermal efficiency.

[0004] Traditional two-stroke engines can achieve power output per revolution, but most of them use a cylinder scavenging port structure, with the intake and exhaust processes overlapping. This generally results in defects such as residual exhaust gas, mixture escape, unstable combustion, severe carbon buildup, poor emission performance, and short overall engine life. If one were to directly attempt to achieve power output per revolution on a four-stroke valve engine, it would be difficult to rationally allocate the various processes due to the excessively large intake angle required by conventional methods.

[0005] Existing turbocharged internal combustion engines, regardless of whether they are single-stage superchargers, turbochargers, or multi-stage tandem superchargers, use the supercharger only as an intake auxiliary mechanism. The engine still retains the piston compression stroke inside the cylinder, and intake air still needs to fill the entire cylinder stroke volume. It has not broken away from the traditional four-stroke cycle framework and cannot fundamentally overcome the efficiency and power frequency bottlenecks of traditional internal combustion engines. In summary, existing internal combustion engines have long faced technical challenges: four-stroke valve structures struggle to achieve power output per revolution; two-stroke engines, which can achieve power output per revolution, have poor scavenging quality; and various supercharging methods only optimize intake pressure and cannot shorten the crankshaft angle required for intake. Currently, there is a lack of a solution based on a four-stroke valve arrangement that can achieve stable, clean, and efficient power output per revolution of the crankshaft under conditions of no in-cylinder compression, no scavenging overlap, and no exhaust gas residue. 3. Summary of the Invention

[0006] 3.1 Purpose of the Invention

[0007] In view of the shortcomings of existing technologies, such as low power frequency, large in-cylinder compression loss, impure air exchange, large crankshaft angle occupation by conventional intake, and the inability of turbocharging to change the cycle nature, this invention provides an externally compressed single-cycle power internal combustion engine.

[0008] This invention abandons the piston-cylinder compression mode and pioneers an external pressurization and accumulation system + significantly shortened intake process + independent power thermodynamic cycle per cycle. Utilizing the characteristics of externally pre-pressurized high-pressure mixture that only needs to fill the combustion chamber space and significantly shortens intake time, it arranges a complete working process within a single crankshaft rotation while retaining the independent intake and exhaust valve structure of a four-stroke engine. It takes into account the advantages of clean air exchange and stable combustion of a four-stroke engine, while achieving high-frequency power at the level of a two-stroke engine, overcoming the inherent shortcomings of traditional internal combustion engines.

[0009] 3.2 Core Technology Solution

[0010] An externally compressed single-cycle internal combustion engine includes a turbocharger, cylinder block, piston, connecting rod, crankshaft, intake valve, exhaust valve, valve drive mechanism, ignition mechanism, and fuel injection mechanism. Its key feature is the inclusion of an external supercharging and accumulating system, independently located outside the cylinder, used to pre-compress and stabilize the intake air, ensuring the air-fuel mixture entering the cylinder directly reaches the rated pressure required for combustion. The engine completely eliminates the piston's downward intake stroke and upward in-cylinder compression stroke, with the piston not bearing the gas compression load. The high-pressure mixture only needs to fill the combustion chamber volume, not the entire cylinder volume corresponding to the piston stroke, resulting in an intake volume that is one-tenth that of traditional engines, significantly reducing the crankshaft angle required for the intake process. Through valve cam profile design or electronic control strategies, the opening and closing times of the intake and exhaust valves are precisely controlled, compressing the intake and exhaust processes within 180 degrees of crankshaft rotation. Each 360° crankshaft rotation completes one independent and complete power stroke. The specific working sequence is as follows:

[0011] S1, Isolation Exhaust Stage: The piston moves upward from the bottom dead center to expel exhaust gas. At the end of the exhaust stroke, before reaching the top dead center, the exhaust valve is closed in advance at a preset crankshaft angle position to completely isolate the exhaust gas in the cylinder and prevent exhaust gas residue and backflow.

[0012] S2, Closed High-Pressure Intake Stage: After the exhaust valve is completely closed, the intake valve is opened, and a stable high-pressure pure air-fuel mixture is input by the external pressurization and accumulation system; the high-pressure mixture quickly fills the combustion chamber area, the intake valve is closed, and a completely closed, pressure-stable homogeneous high-pressure combustion chamber is formed inside the cylinder.

[0013] S3, Fixed-point combustion power stage: When the crankshaft reaches the top dead center position, the ignition mechanism precisely ignites, and the high-pressure homogeneous mixture instantly and fully combusts and expands, pushing the piston downward to do power;

[0014] S4, Cycle Reset Stage: When the piston moves down to the end of its stroke, it opens the exhaust valve again and enters the next cycle of isolated exhaust circulation; thus, the crankshaft completes one pure, sealed, high-pressure, and independent combustion power stroke for each full rotation.

[0015] The external supercharging and accumulator system can be any supercharging device capable of achieving intake pre-compression and pressure stabilization, including but not limited to: single-stage mechanical superchargers, single-stage turbochargers, multi-stage tandem supercharging systems combining mechanical and turbochargers, and electronically controlled superchargers. This cycle structure is adaptable to various external supercharging methods and is not limited by the supercharging structure itself in terms of cycle logic.

[0016] Furthermore, a pressure-stabilizing accumulator chamber is set in the high-pressure intake pipeline to ensure consistent intake pressure each time, thus guaranteeing consistent cyclic operating conditions. Although existing technologies disclose external supercharging devices and valve timing adjustment mechanisms, they do not disclose the complete set of strongly constrained timing logic of this application. Conventional engine intake air needs to fill the entire cylinder stroke volume, occupying a large crankshaft angle, making it difficult to complete all processes within a single cycle; conventional externally supercharged engines still use traditional stroke logic, still requiring the crankshaft to move upward to drive the piston to compress the air-fuel mixture. The core of this invention utilizes the characteristic that the externally pre-compressed air-fuel mixture only fills the combustion chamber and the intake angle is greatly shortened, strictly limiting the sequence of processes: exhaust termination → closing the exhaust valve → opening the intake valve → closing the intake valve before top dead center. The entire timing sequence is mutually coordinated and inseparable. Only by executing this timing sequence can we achieve no scavenging, no exhaust gas mixing, and stable power output per cycle while retaining the independent valve structure of the four-stroke and eliminating in-cylinder compression; this combination brings a comprehensive technical effect that balances high-frequency power output and pure combustion, which cannot be expected by simply adding up existing technologies.

[0017] 3.3 Beneficial Effects

[0018] 1: Achieving two-stroke power density using a four-stroke valve structure. With the help of an external cylinder pre-pressurization scheme, the high-pressure mixture only fills the combustion chamber, significantly shortening the crankshaft angle required for the intake process, allowing a complete working cycle to be arranged within a 360° range of the crankshaft. The crankshaft performs power once per revolution, eliminating the need for a two-stroke scavenging structure, and achieving two-stroke level power density with a four-stroke structure.

[0019] 2: Significantly reduces mechanical losses by eliminating the load of the piston compressing gas during upward movement, greatly reducing frictional losses caused by the piston's reciprocating motion, improving the overall mechanical efficiency, and demonstrating outstanding energy-saving advantages under high-load conditions.

[0020] 3: Inheriting the pure combustion advantages of four-stroke engines, it adopts independent intake and exhaust valves and pre-seal cylinder isolation technology at the exhaust end. There is no residual exhaust gas in the cylinder, no loss of mixed air scavenging, and stable combustion state, solving the defects of traditional two-stroke engines such as serious carbon deposits, poor emissions, and short life.

[0021] 4. Fast power response and high energy conversion efficiency: High-pressure mixture is directly supplied to the combustion chamber, eliminating the lag effect of in-cylinder compression stroke. Homogeneous mixture is burned at a fixed point, resulting in high thermal energy conversion efficiency and rapid transient power response, making it suitable for various power application scenarios.

[0022] 5. Compared with traditional four-stroke engines, it has a lower engine speed and a longer engine life under the same power requirements. 4. Description of the attached drawings

[0023] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0024] Figure 1 Example diagram of the structure

[0025] Figure 2 A diagram showing the process distribution for each revolution of the crankshaft.

[0026] In the diagram: 1. Crankshaft, 2. Connecting rod, 3. Cylinder block, 4. Piston, 5. Exhaust system, 6. Exhaust valve, 7. Valve drive mechanism, 8. Spark plug, 9. Intake valve, 10. High-pressure air accumulator, 11. Boost mechanism, 12. Air filter, 13. Fuel injection mechanism.

[0027] Figure 2 S1 is the exhaust area, S2 is the intake area, and S3 is the ignition and power area. 5. Detailed Implementation

[0028] An externally compressed single-cycle internal combustion engine includes a cylinder block (3), a piston (4), a connecting rod (3), a crankshaft (1), an intake valve (9), an exhaust valve (6), a valve drive mechanism (7), a spark plug (8), a fuel injection device (13), an intake system configured with an external supercharging accumulator system (11), and a pressure stabilizing accumulator chamber (10) installed in the high-pressure intake pipe.

[0029] The working cycle of the whole machine: After the piston (4) finishes its downward power stroke, it moves upward to open the exhaust valve (6) and discharge the combustion exhaust gas. At the end of the exhaust stroke, the valve drive mechanism controls the exhaust valve (6) to close completely to isolate the exhaust gas. Then the intake valve (9) is opened, and the high-pressure fresh mixture quickly fills the combustion chamber. The crankshaft (1) continues to move to the top dead center. Before reaching the top dead center, the crankshaft (1) sets a turning angle, closes the intake valve (9), and seals the cylinder. When the crankshaft (1) reaches the top dead center, the spark plug (8) ignites, and the high-pressure mixture expands to push the piston (4) downward to output power. When the piston (4) reaches the bottom dead center, the exhaust valve (6) opens and enters the exhaust process again. The crankshaft (1) rotates 360° to complete one round of exhaust, intake, ignition and power stroke, and continues to cycle.

[0030] The high-pressure mixture is pre-pressurized to the rated pressure required for combustion and power generation, without the need for piston (4) compression, and only fills the combustion chamber space. The intake angle required is much smaller than that of a traditional internal combustion engine, so that the intake and exhaust processes can be compressed within the working cycle of 180 degrees crankshaft rotation.

[0031] Example 1: The external supercharging and accumulator system uses a single mechanical supercharger.

[0032] Example 2: The external turbocharger accumulator system uses a single turbocharger.

[0033] Example 3: The external supercharging and accumulator system adopts a two-stage series arrangement of mechanical supercharger and turbocharger.

[0034] Example 4: The external supercharging and accumulator system uses an electric supercharger.

[0035] Preferred embodiment: The technology of the present invention can be combined with the applicant's previously submitted technology "A High Conversion Rate Angle Ignition Engine" to form the optimal embodiment.

[0036] The variable-length connecting rod mechanism disclosed in (a high-conversion-rate angle ignition engine) changes the fixed geometric connection between the piston and the crankshaft, so that the crankshaft forms an independent angular range of about 50° between the top dead center and the ignition angle. The exhaust process is completed during the piston's upward movement, and the high-pressure mixture intake process is completed using the aforementioned independent angular window. It is not necessary to compress the exhaust and intake processes within a 180° crankshaft angle, which effectively alleviates the pressure of the valve timing, improves the intake efficiency, and each power stroke is performed within the crankshaft's maximum lever arm range, forming an optimal combination of high power density and high mechanical conversion rate.

Claims

1. An externally compressed single-cycle internal combustion engine, comprising a cylinder block, piston, connecting rod, crankshaft, intake valve, exhaust valve, valve drive mechanism, ignition mechanism, fuel injection mechanism, and external supercharging and accumulating mechanism, characterized in that: An external supercharging and accumulating system is installed outside the cylinder to pre-compress and stabilize the air entering the cylinder, ensuring that the intake air directly reaches the working pressure required for combustion. The internal combustion engine completely eliminates the piston's upward compression stroke within the cylinder, and the piston does not bear the gas compression load. The high-pressure mixture only fills the combustion chamber volume, without needing to fill the cylinder volume corresponding to the piston stroke. The crankshaft angle required for intake is significantly shortened, and the intake and exhaust processes are distributed within a 180° crankshaft rotation. The internal combustion engine uses a single crankshaft revolution independent power cycle, and the working steps include: S1. During the upward exhaust process of the piston, the exhaust valve is closed in advance at the end of the exhaust stroke to isolate the exhaust gas in the cylinder. S2. After the exhaust valve is completely closed, the intake valve is opened, and a high-pressure pure air-fuel mixture is input into the cylinder through the external supercharging and accumulating system. During the crankshaft's movement to the piston's top dead center, the intake valve is closed in advance before the top dead center, so that the cylinder forms a sealed high-pressure chamber. S3. When the crankshaft reaches top dead center, the ignition mechanism ignites, and the high-pressure mixture explodes, pushing the piston downward to do work. S4. After the piston moves downwards to perform its power stroke, it opens the exhaust valve to expel the combustion exhaust gas, and the cycle repeats. This allows the internal combustion engine crankshaft to complete one independent, closed, and pure combustion power cycle for each full 360° rotation.

2. The externally compressed single-cycle internal combustion engine according to claim 1, characterized in that: Internal combustion engines do not have an in-cylinder gas compression process; the pressure required for combustion is entirely established by an external pressurization and accumulation system.

3. The externally compressed single-cycle internal combustion engine according to claim 1, characterized in that: Internal combustion engines have no piston-less downward intake process; the intake timing is between before top dead center and the end of exhaust. High-pressure injection is achieved by an external turbocharger.

4. The externally compressed single-cycle internal combustion engine according to claim 1, characterized in that: The external supercharging and accumulator system is any one of a single-stage mechanical supercharger, a single-stage turbocharger, or a multi-stage series supercharging device.

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