Two-stroke internal combustion engine

Abstract

The invention relates to a two-stroke internal combustion engine, which transfers the power of a plurality of reciprocating pistons to a central shaft by means of a swash plate and allows a variable adjustment of the displacement and a variable change of the compression ratio. Such a two-stroke internal combustion engine can be used in the automotive industry, in shipping, in aviation and in the energy supply sector. Furthermore, a two-stroke internal combustion engine can be used in the case of operating modes that require particularly low noise, for example in military technology. The problem addressed by the invention is to develop the adjustment possibilities and control possibilities of the swash plate in order to achieve an optimum effectiveness of the two-stroke motor, to reduce the design complexity and the associated material costs and to achieve a low-noise operating mode. The solution to the problem is that the tiltable swash plate holder, which is connected to the swash plate, is connected to a drive shaft via a mechanical adjustment assembly, which achieves a stepless change of the tilt angle of the swash plate, and that a control device for controlling the tilt angle is assigned to the swash plate holder.

Description

Technical Field

[0001] This invention relates to a two-stroke internal combustion engine that transmits power from a plurality of reciprocating pistons to a central shaft via a swashplate, and enables variable adjustment of engine displacement and compression ratio. Applications of this two-stroke internal combustion engine include the automotive, maritime, aerospace, and power industries. Furthermore, it is used in applications where low-noise operation is particularly critical (e.g., in military technology). Background Technology

[0002] According to EP2 423 484A1, swashplate engines are known in the prior art, in which a swashplate connected to a drive shaft is driven by piston rods of at least two pistons. The pistons are arranged radially around the drive shaft. The combustion chamber of the cylinder is connected to a pre-compression chamber via a flow passage. This operating position is always employed when the piston moves from its top dead center to its bottom dead center. However, a disadvantage of this swashplate engine is that the tilt angle of the swashplate cannot be adjusted for optimal efficiency.

[0003] In addition, DE 10 2012 217 045 B3 also describes a two-stroke swashplate engine, including:

[0004] The package includes a housing, a drive shaft with a swashplate connected thereto, at least one cylinder having at least one combustion chamber, and at least one piston arranged in the respective cylinder and reciprocating substantially parallel to the output shaft within the cylinder.

[0005] A piston rod, used to transmit the driving force generated in the combustion chamber from the piston to the swashplate.

[0006] The piston is designed as a hollow piston, and its outer surface is defined by at least a portion of the combustion chamber, and its inner surface is defined by at least a portion of the intake chamber. The cylinder includes at least one temporary inlet in the region of the intake chamber.

[0007] A flow passage connects the intake chamber and the combustion chamber, at least temporarily. Furthermore, the present invention relates to a method for operating a two-stroke swashplate engine. This two-stroke swashplate engine also does not allow for adjustment of the swashplate tilt angle, which is necessary to achieve optimal efficiency.

[0008] US 40 77 269 describes a reciprocating piston engine with variable engine displacement and / or variable compression ratio. This solution is applicable to any engine or machine comprising a drive shaft or output shaft and one or more cylinders arranged substantially parallel to that drive shaft. The piston in the cylinder is thus connected to the drive shaft, such that the reciprocating motion of the piston is converted into the rotational motion of the drive shaft, and vice versa. The engine can be an internal combustion engine powered by fuels such as gasoline, diesel, natural gas, butane, propane, or other combustible fuels. Alternatively, it can be an external combustion engine, such as a Stirling engine. It can also be a pump or compressor, in which the piston is driven by the drive shaft. Although this swashplate engine is a solution where the swashplate tilt angle can be adjusted, the cylinder of the motor is rigidly connected to the housing and therefore cannot perform rotational movement. Furthermore, the described solution is a four-stroke engine requiring a complex valve mechanism. Under conditions requiring significantly less than its full power potential, such as in motor vehicles traveling at constant speeds on flat, smooth highways, the optimal, less complex adjustment of this engine is possible only to a very limited extent.

[0009] Furthermore, US 3,151,528 discloses a swashplate engine comprising a combination of a rotatably mounted cylinder housing and a plurality of cylinder bores extending parallel to the central axis of the component and arranged in a circular pattern. The engine also includes a piston assembly slidably disposed in each cylinder bore for reciprocating motion. The swashplate assembly is attached to a power take-off shaft coaxially and rotatably mounted relative to the housing, and the reciprocating piston assembly is operably connected to the shaft. As a result of this reciprocating motion, an angular force component is converted into an angular force component applied to the shaft, rotating the shaft in a particular direction and causing the housing to rotate in the opposite direction. Each cylinder bore is connected to a liquid fuel source by means of fluid inlet and outlet conduits within the housing element. Rotatably mounted valves coaxially engaged with the shaft sequentially open and close the corresponding fluid flow connections between the conduits and the cylinder bores. A first and second balancing device, connected to the shaft and having centers of mass eccentric relative to the shaft's axis of rotation, are used. The first balancing device is axially spaced relative to the second balancing device, and the centers of mass of the first and second balancing devices are positioned such that they are radially opposite to the center of mass of the swashplate assembly. This solution balances the forces causing vibration. This involves balancing three forces acting in three different directions. First, this involves the axial force generated by the reciprocating motion of the associated piston; second, this involves the centrifugal force applied to the eccentric mass of the swashplate element; and third, this involves the force generated by the inertia of the reciprocating piston. By compensating for the resulting vibrations, the operating characteristics of the vehicle (especially a torpedo) are improved. However, these measures do not necessarily improve the efficiency of the swashplate engine.

[0010] In vehicle internal combustion engines for gasoline and diesel processes, characterized by variable stroke and near-constant compression, a movable main shaft is used, as disclosed in DE 30 43 251 A1, where the swashplate is axially displaced by means of a hydraulic piston. The angular position of the swashplate is changed via a pushrod, thereby altering the piston's stroke and compression ratio. While this solution reduces technical complexity, it only improves engine efficiency to a limited extent.

[0011] Furthermore, according to publication AT 507 824 A1, an internal combustion engine with a swing-mounted deflector is known, comprising at least three pistons, each guided in a cylinder and engaged with the swing-mounted deflector via an articulated piston rod. A gear ring is arranged on the piston-facing side of the swing-mounted deflector, meshing with a gear ring fixed to the engine housing. The proposed solution aims to improve and simplify the support of the high-pressure deflector on the engine housing. Similarly, the transmission of force from the piston to the deflector via the piston rod will be optimized. Therefore, a bearing surface is arranged on the piston-opposite side of the swing-mounted deflector, via which the deflector is supported on the engine housing or on a counter-running surface fixed to the engine housing. Compared to the prior art, this solution also fails to achieve a significant improvement in efficiency.

[0012] The improved internal combustion engine with variable stroke and constant compression ratio proposed in DE 11 2018 001 177 T5 describes an internal combustion engine capable of continuously variable engine displacement. For this purpose, several pistons arranged in the cylinder are connected to a swashplate. The crankshaft, housed in the crankcase, includes an upper journal and a lower journal, each journal arranged at a predetermined angle to the axis. A first sliding ball engages with the upper journal, and a second sliding ball engages with the lower journal. A bracket assembly for accommodating the sliding balls includes an actuation cylinder. Within the actuation cylinder is a translationally movable actuation piston assembly connected to the crankshaft between the upper and lower journals. A support assembly with the actuation cylinder and sliding balls rotates with the crankshaft as a control assembly. In doing so, the bracket assembly slides on the journal and is controlled, for example, by a hydraulic circuit. However, the disadvantage of this solution is its complex and technically demanding design. Furthermore, the potential for improving efficiency is limited by the given internal movement space within an internal combustion engine. Summary of the Invention

[0013] Therefore, the object of the present invention is to expand the adjustment and control options of the swashplate to achieve optimal efficiency in two-stroke engines, while also reducing design complexity and material requirements, and achieving quieter operation.

[0014] This task is solved by a solution based on the technical features described in claim 1 of the patent. Further advantageous developments of the two-stroke internal combustion engine are described by the features of claims 2 to 10 of the patent.

[0015] The design of the two-stroke internal combustion engine includes a tiltable swashplate retainer connected to the swashplate, the swashplate retainer being connected to the drive shaft via a mechanical adjustment assembly that enables stepless adjustment of the swashplate tilt angle, and wherein a control device for controlling the tilt angle is associated with the swashplate retainer.

[0016] To facilitate the use of standard components, the mechanical adjustment assembly for the stepless variation of the swashplate's tilt angle is designed as a joint. This constant-speed joint is effectively used to achieve optimal power transmission, high operational stability, and noise reduction.

[0017] By combining in-cylinder ventilation within the cylinder head during the stroke, the (passively) generated heat energy is advantageously dissipated.

[0018] The design of the swashplate engine has proven to be vibration-damping because the stroke cylinders are arranged in a cylinder block that is securely connected to the drive shaft.

[0019] To achieve a material-saving design for the mechanical components, the joints are designed as constant-velocity joints.

[0020] In order to achieve a simple and effective controllable design for the two-stroke internal combustion engine, the control device for controlling the tilt angle of the swashplate is designed as an electro-hydraulic control device.

[0021] By connecting the swashplate retainer to an eccentric portion that provides a coarse adjustment range for the tilt angle, operating in parallel with the mechanical adjustment assembly, the adaptability of the two-stroke internal combustion engine to different fuels or lower-quality fuels is effectively enhanced. After the coarse adjustment is achieved by adjusting the eccentric portion, fine adjustment is then performed within the adjustment range provided by the coarse adjustment using the mechanical adjustment assembly.

[0022] According to the present invention, a significant expansion of possible adjustability is achieved through only the combination of the operating modes of the mechanical adjustment component and the eccentric part, up to the point of reaching optimal efficiency.

[0023] When the control device used to control the tilt angle of the swashplate is designed as an electromechanical control device, the most precise efficiency optimization is advantageously achieved. Attached Figure Description

[0024] The invention will now be explained in more detail with reference to implementation examples. The accompanying drawings, included in the specification, illustrate:

[0025] Figure 1 A schematic cross-sectional view of the internal structure of a swashplate engine.

[0026] Figure 2 Schematic side view of the engine.

[0027] Figure 3 Schematic diagram of section EE

[0028] Figure 4 A schematic front view of the engine, and

[0029] Figure 5 : A schematic diagram of an engine in the form of a longitudinal cross-section. Detailed Implementation

[0030] Figure 1 A cross-sectional view of the internal structure of a two-stroke swashplate engine is shown. Within a cooling housing 1, a drive shaft 2 is connected to a cylinder block 10 via ball bearings 9 and is also connected to the engine's cooling housing 1. The engine's stroke cylinders 4 are arranged in a circular pattern around the drive shaft 2 within the cylinder block 10. Above the cooling housing 1 is a mounting point for a control device 11, which is used for stepless control of the swashplate's tilt angle. The swashplate's tilt angle is adjusted by means of a hydraulic cylinder 13. The drive shaft 2 is connected to a swashplate retainer 12 via a constant-speed joint 8. The tilt angle is controlled via the control device 11 connected to the hydraulic cylinder 13. The control device 11 can be designed as an electromechanical, electrohydraulic, or electronic control device 24 and is used to adjust the swashplate's tilt angle within the maximum possible adjustment range allowed by the design. The actuator of the control device is a lever system or an electro-hydraulic lifting system connected to the hydraulic cylinder 13. The swashplate 3 is held by the swashplate retainer 12. Power is transmitted to the drive shaft 2 via the constant-speed joint 8.

[0031] from Figure 2 The diagram shows a schematic side view of the engine. It illustrates the connection between the tiltable swashplate retainer 12 and the swashplate 3, which is connected to the drive shaft 2 via a hinge joint. This hinge joint allows for continuous / stepless adjustment of the swashplate 3's tilt angle. As the tilt angle changes steplessly, the engine displacement in the cylinder chamber changes accordingly, resulting in a significant change in the compression ratio. The piston of this cylinder is connected to the swashplate 3 via its corresponding piston rod. Controlled adjustment of the swashplate 3's tilt angle allows the engine to operate in a manner adapted to power requirements. A constant compression / working volume ratio can be established by moving the intake slot 18 and the outlet slot 19. While a higher engine output is achieved through a constant compression / working volume ratio, efficiency is reduced. An inconsistent compression / working volume ratio does slightly reduce power output. However, this results in higher efficiency.

[0032] Figure 3 The illustration shows the area passing through the front section of the engine. Figure 2 A view of section EE marked in the middle. It shows a front view of eccentric part 14, which is used to perform preset adjustments (to the tilt angle) to be achieved during engine operation. Two components of eccentric part 14, arranged on either side of the engine, are connected to each other via drive shaft 15. Different fuels, for example, with different quality characteristics, are optimally incorporated into the control process by means of corresponding eccentric adjustments. By taking these differences in control into account, the desired optimal efficiency of the two-stroke engine can be achieved, thereby enabling spark-controlled compression ignition (SPCCI). For this purpose, two eccentric components are arranged on either side of eccentric part 14 via the drive shaft of gear motor 16 of eccentric part 14. Eccentric part 14 and hydraulic cylinder 13 are controlled in parallel via a shared control device.

[0033] Figure 4 The front view of the engine shown illustrates the arrangement of the gear motor 22 for fine adjustment, as well as the partial arrangement of the outlet slot 18 and the intake slot 19. Furthermore, the figure shows the arrangement of the injection nozzle 20 and the spark plug 21.

[0034] Figure 5 The arrangement of combustion chamber 5, in addition to the engine components already described, is shown.

[0035] Reference Symbol List 1 Cooling housing 2 drive shafts 3. Sloping plate 4-stroke cylinder 5 Combustion Chamber 6-cylinder piston 7 Piston Rod 8 Constant speed joints 9 Ball bearings 10-cylinder block 11 Control equipment 12 Swashplate retainer 13 Hydraulic cylinders 14. Eccentric part 15. Drive shaft with eccentric part 16. Drive shaft of gear motor 17 Half-shaft components 18. Outlet slot 19. Intake slot 20 Injection Nozzles 21 Spark plugs 22 Gear motors for fine adjustment 23. Balance joints 24. Electronic control equipment.

Claims

1. A two-stroke internal combustion engine, wherein the two-stroke internal combustion engine transmits power from a plurality of reciprocating pistons to a central shaft by means of a swashplate arranged between a drive shaft and a piston rod, wherein the swashplate is used to control the corresponding engine displacement and compression ratio. Its features are, A tiltable swashplate retainer (12) is connected to the swashplate (3), and the swashplate retainer (12) is connected to the drive shaft (2) via a mechanical adjustment assembly that enables stepless adjustment of the tilt angle of the swashplate (3). The control device (11) for controlling the tilt angle is associated with the swashplate retainer (12).

2. The two-stroke internal combustion engine according to claim 1, characterized in that, The adjustment assembly for the stepless change of the tilt angle of the swashplate (3) is designed as a joint (8).

3. The two-stroke internal combustion engine according to claim 2, characterized in that, The joint (8) is designed as a constant velocity joint.

4. The two-stroke internal combustion engine according to claim 1, characterized in that, At least one cylinder vent is located in the stroke cylinder (4) inside the cylinder head.

5. The two-stroke internal combustion engine according to claim 1, characterized in that, The stroke cylinder (4) is arranged in the cylinder body (10), which is fixedly connected to the drive shaft (2).

6. The two-stroke internal combustion engine according to claim 1, characterized in that, The control device (11) used to control the tilt angle is designed as an electro-hydraulic control device.

7. The two-stroke internal combustion engine according to claim 1, characterized in that, The control device (11) used to control the tilt angle is designed as an electromechanical control device (24).

8. The two-stroke internal combustion engine according to claim 1, characterized in that, The swashplate retainer (12) is connected to the eccentric part (14) in a manner that operates in parallel with the mechanical adjustment assembly, the eccentric part (14) being used to coarsely adjust the range of the tilt angle.

9. The two-stroke internal combustion engine according to claim 1, characterized in that, The eccentric part (14) includes an eccentric assembly arranged on both sides of the drive shaft (15) and connected to the swashplate retainer (12).

10. The two-stroke internal combustion engine according to claim 1, characterized in that, The control device (11) for controlling the tilt angle is arranged downstream of the mechanical adjustment assembly, and is arranged parallel to the mechanical adjustment assembly downstream of the eccentric assembly. The control device (11) is connected to a sensor that detects the type of fuel supplied and the corresponding tilt angle of the swashplate (3).

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