Two-stroke internal combustion engine

Abstract

The invention relates to a two-stroke internal combustion engine, which transfers, by means of swash plates, the power of a plurality of reciprocating pistons to a central shaft and permits a variable adjustment of the displacement and a variable change to the compression ratio. This two-stroke internal combustion engine can be used in the fields of the automotive industry, seafaring, aviation and power energy supply. Furthermore, the two-stroke internal combustion engine can be used where a particularly low-noise mode of operation (e.g. military technology) is required. The problem addressed by the invention consists in developing the adjustment possibilities and control possibilities of the swash plate in order to achieve optimum effectiveness of the two-stroke motor, to reduce the design complexity and associated material costs and achieve a low-noise mode of operation. The problem is solved in that a tiltable swash plate holder, connected to the swash plate, is connected to the drive shaft via a mechanical adjustment assembly which effects a stepless change in the angle of incidence of the swash plate, and that a control device, used to control the angle of incidence, is allocated to the swash plate holder.

Description

[0001] Two-stroke internal combustion engine. The invention relates to a two-stroke internal combustion engine that transmits the power of several reciprocating pistons to a central shaft by means of swash plates, enabling variable displacement adjustment and variable compression ratio changes. The application areas of this two-stroke internal combustion engine are in the automotive, marine, aviation, and power generation industries. Furthermore, the two-stroke internal combustion engine is used where low-noise operation is particularly required (e.g., military technology). EP 2423484 A1 discloses a swash plate engine in which a swash plate connected to the drive shaft is driven by piston rods of at least two pistons. The pistons are arranged radially around the drive shaft. The combustion chambers of the cylinders are connected to a pre-compression chamber via transfer channels.This working position is always assumed when the piston moves from its top dead center to its bottom dead center. However, the disadvantage of this swashplate engine is that the angle of attack of the swashplate cannot be adjusted to achieve optimal efficiency.Furthermore, DE 102012217045 B3 also describes a two-stroke swash plate engine with a housing, a drive shaft with a swash plate connected thereto, at least one cylinder, wherein the cylinder has at least one combustion chamber, and with at least one piston which is arranged in the respective cylinder and moves reciprocally therein essentially parallel to the output shaft, a piston rod for transmitting the drive force generated in the combustion chamber from the piston to the swash plate, wherein the piston is designed as a hollow piston, and the piston delimits the combustion chamber at least in sections with its outer side and delimits the intake chamber at least in sections with its inner side, and in the region of the intake chamber the cylinder has at least one temporary inlet, and an overflow channel which at least temporarily connects the intake chamber and the combustion chamber.Furthermore, the invention relates to a method for operating a two-stroke swashplate engine. Adjusting the angle of attack of the swashplate, which is necessary to achieve optimal efficiency, is also not possible with this two-stroke swashplate engine. US 4077269 describes a reciprocating piston engine with variable displacement and / or variable compression ratio. This solution is applicable to any engine or machine having a drive or output shaft and one or more cylinders arranged substantially parallel to the drive shaft. The pistons in the cylinder are connected to the drive shaft in such a way that a reciprocating movement of the piston is translated into a rotary movement with the drive shaft and vice versa. The engine can be an internal combustion engine powered by a fuel such as gasoline, diesel, natural gas, butane, propane, or another combustible fuel.In addition, it can be an external combustion engine such as a Stirling engine. It can also be a pump or a compressor where the pistons are driven by the drive shaft. Although this swashplate engine represents a solution in which the angle of attack of the swashplate can be adjusted, the engine cylinders are rigidly connected to the housing and therefore cannot exert any rotational movement. Furthermore, the described solution is a four-stroke engine, which requires a complex valve train. Optimal, less complex adjustment of the engine under conditions that require significantly less than its full power potential, such as a motor vehicle traveling at a constant speed on a flat, smooth highway, is only possible to a very limited extent with this engine.Also known from US 3,151,528 is a swashplate engine consisting of a combination of a rotatably mounted cylinder housing with a plurality of cylinder bores extending parallel to the central axis of the component and arranged in a circle. Furthermore, the engine has piston means slidably arranged in each cylinder bore for reciprocating movement. A swashplate device is attached to the shaft via a power take-off shaft, which is mounted coaxially and rotatably with respect to the housing, to which the reciprocating piston device is operatively connected. Due to the reciprocating movement, the conversion into an angular force component occurs, which is exerted on the shaft to rotate the shaft in a specific direction and thereby cause the housing to rotate in the opposite direction.Through the use of fluid supply and outlet lines within the housing element, each of the cylinder bores is connected to a liquid fuel source. A rotatably mounted valve, coaxially engaged with the shaft, sequentially opens and closes the respective fluid flow connection between the lines and the cylinder bores. Via first and second balancing means connected to the shaft and having centers of mass eccentric to the shaft's rotational axis, the first balancing means being axially spaced from the second balancing means, the centers of mass of the first and second balancing means are aligned so that they are diametrically opposed to the center of mass of the swashplate assembly. This solution balances the forces that cause vibrations.This involves balancing three forces acting in three different directions. First, this concerns an axially directed force generated by the reciprocating movement of the connected pistons; second, a centrifugal force exerted on the eccentric mass of the swashplate element; and third, a force generated by the inertia of the reciprocating pistons. By balancing the resulting vibrations, the operating characteristics of the vehicle, particularly of a torpedo, are improved. However, an increase in the efficiency of the swashplate engine cannot be achieved with these measures. In the vehicle internal combustion engine for gasoline and diesel processes with variable stroke and approximately constant compression with a movable main shaft, disclosed in the document DE 3043251 A1, the swashplate is axially displaced by means of a hydraulic piston.The angular position of the swash plate is changed via thrust levers, and thus the piston stroke and compression. Although this solution reduces the technical complexity, the engine's efficiency is only slightly increased. Also known, according to the document AT 507824 A1, is an internal combustion engine with a wobbling-mounted deflector body. This engine has at least three pistons, each guided in cylinders, which act on a wobbling-mounted deflector body via articulated piston rods. On the side of the wobbling-mounted deflector body facing towards the piston, a gear ring is arranged which meshes with a gear ring fixed to the engine housing. The solution presented is intended to improve and simplify the support of the deflector body, which is under high pressure, on the engine housing. Likewise, the force introduction from the pistons via the piston rods into the deflector body is to be optimized.For this purpose, a bearing surface is arranged on the side of the wobble-mounted deflecting body facing away from the piston, via which the deflecting body is supported on the engine housing or on a counter-running surface fixed to the engine housing. Even with this solution, a significant increase in efficiency compared to the prior art cannot be achieved. The improved internal combustion engine with variable stroke and constant compression ratio presented in the document DE 112018001177 T5 describes an internal combustion engine that enables continuously adjustable displacement. For this purpose, several pistons arranged in a cylinder block are connected to a nutator. The crankshaft, housed in a crankcase, contains an upper and a lower journal, each arranged at a predetermined angle to the axis. A first sliding ball engages the upper journal and a second sliding ball engages the lower journal.A support assembly for the sliding balls contains an actuating cylinder. Within the actuating cylinder is a translationally displaceable actuating piston assembly, which is connected to the crankshaft between the upper and lower journals. The support assembly, including the actuating cylinder and the sliding balls, rotate together with the crankshaft as a control assembly. The support assembly slides onto the journal and is controlled, for example, by a hydraulic circuit. A disadvantage of this solution, however, is its complicated and technically complex design. Furthermore, any increase in efficiency is limited by the given internal movement space within the internal combustion engine.The object of the invention is therefore to expand the adjustment and control options of the swash plate in order to achieve optimal efficiency of the two-stroke engine, while also reducing the structural complexity and the required material expenditure, as well as achieving quieter operation. This object is achieved by the solution according to the descriptive technical features of patent claim 1. Advantageous developments of the two-stroke internal combustion engine are described by the features of patent claims 2 to 10.The design of the two-stroke internal combustion engine comprises a tiltable swashplate holder connected to the swashplate, which is connected to the drive shaft via a mechanical adjustment assembly that enables a continuous change in the swashplate's angle of attack. A control device for controlling the angle of attack is assigned to the swashplate holder. To facilitate the use of standard assemblies, the mechanical adjustment assembly that enables a continuous change in the swashplate's angle of attack is designed as a joint. A constant velocity ball joint is efficiently used to achieve optimal power transmission, high running stability, and noise reduction. The dissipation of negatively occurring heat energy is advantageously achieved by incorporating cylinder ventilation into the lifting cylinders within the cylinder head.The design of the swashplate engine reduces vibrations by arranging the lifting cylinders in a cylinder drum that is firmly connected to the drive shaft. To save material on the mechanical assemblies, the joint is designed as a constant velocity ball joint. To achieve a simple and efficient controllable design of the two-stroke internal combustion engine, the control device for controlling the swashplate angle of attack is designed as an electrohydraulic control. An increase in the adaptability of the two-stroke internal combustion engine to different fuels or lower-quality fuels is efficiently achieved by connecting the swashplate holder, acting parallel to the mechanical adjustment assembly, to an eccentric for coarse adjustment of the angle of attack adjustment range.After the coarse adjustment has been made by adjusting the eccentric, the fine adjustment is then carried out using the mechanical adjustment assembly within the adjustment range specified by the coarse adjustment. Only through the inventively created combination of the effects of the mechanical adjustment assembly and eccentric is a significant expansion of the possible adjustability until the optimum efficiency is achieved. The most precise optimization of the efficiency is advantageously achieved if the control device for controlling the angle of attack of the swash plate is designed as an electromechanical control. The invention will be explained in more detail below using an exemplary embodiment. The drawings included in the description show: Fig. 1: the schematic sectional view of the internal structure of the swash plate motor, Fig. 2: the schematic side view of the motor, Fig.3: the schematic view of the sectional view E - E, Fig. 4: the schematic front view of the engine, and Fig. 5: the schematic representation of the engine in the form of a longitudinal section. The illustration in Figure 1 shows a sectional view of the internal structure of the two-stroke wobble engine. Within the cooling housing 1, the drive shaft 2 is connected to the cylinder drum 10 via the ball bearing 9 with the cooling housing 1 of the engine. The cylinders 4 of the engine are arranged in a circle around the drive shaft 2 within the cylinder drum 10. Above the cooling housing 1 is the mounting location of the control device 11 for continuously controlling the angle of attack of the swash plate. The angle of attack of the swash plate is adjusted by means of the hydraulic cylinder 13. The drive shaft 2 is connected to the swash plate holder 12 via the constant velocity joint 8. The angle of attack is controlled via the control device 11 connected to the hydraulic cylinder 13.This control device 11 can be designed as an electromechanical, electrohydraulic, or electronic control device 24 and serves to adjust the swashplate's angle of attack within the maximum design adjustment range. A lever system connected to the hydraulic cylinder 13 or an electrically controllable lifting system serves as the control element. The swashplate 3 is held by the swashplate holder 12. Power is transmitted to the drive shaft 2 via the constant velocity joint 8. The schematic side view of the motor can be seen in the drawing in Figure 2. Shown is the connection of the tiltable swashplate holder 12 to the swashplate 3, which is connected to the drive shaft 2 via a joint. The integration of the joint enables the continuous change of the angle of attack of the swashplate 3.With the continuous change in the angle of attack, the displacement in the cylinder chambers changes, thereby causing a significant change in the compression ratio. The cylinder pistons are connected to the swash plate 3 by means of the respective piston rods. The controlled change in the angle of attack of the swash plate 3 enables engine operation adapted to the power requirements. By shifting the inlet and exhaust ports 18, 19, a constant compression / working ratio can be achieved. Although a constant compression / working chamber ratio results in higher engine power, efficiency decreases. By creating an unequal compression / working chamber ratio, power is reduced somewhat, but higher efficiency is achieved.Figure 3 shows the view of section EE marked in Figure 2 through the front compartment of the engine. It shows, among other things, the front view of the eccentric 14, which is used to preset the angle of attack adjustments to be achieved during engine operation. The two assemblies of the eccentric 14 arranged to the sides of the engine are connected to each other via the drive shaft 15. Different fuels used, which, for example, have different quality characteristics, are optimally incorporated into the control process by appropriate eccentric adjustment. By taking these differences into account during control, the desired optimal efficiency of the two-stroke engine can be achieved and enables S Park Controlled Compression Ignition (SPCCI). For this purpose, two eccentric assemblies are arranged on either side of the eccentric 14 via the drive shaft of the gear motor 16 of the eccentric 14.The eccentric 14 and the hydraulic cylinder 13 are controlled in parallel via a common control device. The front view of the engine shown in Figure 4 shows the arrangement of the geared motor 22 for fine adjustment and the partially shown arrangements of the exhaust slots 18 and the inlet slots 19. Furthermore, the figure shows the arrangements of an injection nozzle 20 and a spark plug 21. Figure 5 shows the arrangement of the combustion chambers 5 in addition to the engine components already described.

[0002] Reference symbolCooling housingDrive shaftSwashplate Zylinder Brennraum Cylinder pistonPiston rodConstant velocity jointBall bearingCylinder drumControl deviceSwashplate holderHydraulic cylinder Exzenter Eccentric drive shaftGear motor drive shaftHalf-shaft elementExhaust slotInlet slotInjector ZündkerzeGear motor for fine adjustmentCompensation jointElectronic control device

Claims

Patent claims 1. Zweitakt-Verbrennungsmotor, der mittels zwischen Antriebswelle und Kolbenstangen angeordneter Taumelscheiben die Leistung mehrerer Hubkolben auf eine zentrale Welle überträgt, wobei die Taumelscheiben zur Steuerung des jeweiligen Hubraumes und des Verdichtungsverhältnisses dienen, dadurch gekennzeichnet, dass ein mit der Taumelscheibe (3) verbundener kippbarer Taumelscheibenhalter (12) über eine eine stufenlose Änderung des Anstellwinkels der Taumelscheibe (3) bewirkende mechanische Verstellbaugruppe mit der Antriebswelle (2) verbunden ist sowie dem Taumelscheibenhalter (12) eine zur Steuerung des Anstellwinkels dienende Steuereinrichtung (11) zugeordnet ist.

2. Zweitakt-Verbrennungsmotor nach Patentanspruch 1, dadurch gekennzeichnet, dass die zur The adjustment assembly used to continuously change the angle of attack of the swash plate (3) is designed as a joint (8).

3. Zweitakt-Verbrennungsmotor nach Patentanspruch 2, dadurch gekennzeichnet, dass das Joint (8) is designed as a constant velocity ball joint.

4. Zweitakt-Verbrennungsmotor nach Patentanspruch 1, dadurch gekennzeichnet, dass in den Hubzylindern (4) innerhalb des Zylinderkopfes mindestens eine Zylinderdurchlüftung is introduced.

5. Zweitakt-Verbrennungsmotor nach Patentanspruch 1, dadurch gekennzeichnet, dass die Lifting cylinders (4) are arranged in a cylinder drum (10) which is firmly connected to the drive shaft (2).

6. Zweitakt-Verbrennungsmotor nach Patentanspruch 1, dadurch gekennzeichnet, dass die Steuereinrichtung (11) zur Steuerung des Anstellwinkels als elektrohydraulische Steuerung is trained.

7. Zweitakt-Verbrennungsmotor nach Patentanspruch 1, dadurch gekennzeichnet, dass die Steuereinrichtung (11) zur Steuerung des Anstellwinkels als elektromechanische Steuerung (24) is trained.

8. Zweitakt-Verbrennungsmotor nach Patentanspruch 1, dadurch gekennzeichnet, dass der Taumelscheibenhalter (12) parallel wirkend zur mechanischen Verstellbaugruppe mit einem zur Grobeinstellung des Verstellbereiches des Anstellwinkels dienenden Exzenter (14) verbunden is.

9. Zweitakt-Verbrennungsmotor nach Patentanspruch 1, dadurch gekennzeichnet, dass der Eccentric (14) with eccentric assemblies arranged on both sides of a drive shaft (15) and connected to the swash plate holder (12).

10. Zweitakt-Verbrennungsmotor nach Patentanspruch 1, dadurch gekennzeichnet, dass die Steuereinrichtung (11) zur Steuerung des Anstellwinkels der mechanischen Verstellbaugruppe und parallel dazu den Exzenterbaugruppen nachgeordnet ist sowie die Steuereinrichtung (11) mit Sensoren verbunden ist, die die Art des zugeführten Brennstoffes und den jeweiligen Anstellwinkel der Taumelscheibe (3) erfassen.

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