Cylinder arrangement for an internal combustion engine with movable cylinder cover and slide valve arrangement

Abstract

Cylinder arrangement for an internal combustion engine with a cylinder housing (4) in which a working piston (8) is provided, wherein the cylinder housing (4) is closed at a first end by a cylinder cover (6) movable by means of a first drive device (20), the cylinder cover having a cover circumferential surface (16), such that a combustion chamber (10) is formed between the working piston (8) and the cylinder cover (6), wherein a slide arrangement (18), which can be actuated by a second drive device (44), is provided for opening and closing combustion air inlet openings (32) and exhaust gas outlet openings (34) arranged in the cylinder housing (4), wherein the cylinder cover (6) is movably arranged such that an overlap in the radial direction of the cover circumferential surface (16) with the combustion air inlet openings (32) and exhaust gas outlet openings (34) is possible, characterized in thatthat a circumferential edge of the cover circumferential surface (16) directed towards the combustion chamber (10) has a number of angled sections (72) corresponding to the combustion air inlet openings (32) and exhaust gas outlet openings (34).

Description

[0001] The invention relates to a cylinder arrangement for an internal combustion engine with a cylinder housing in which a working piston is provided, wherein the cylinder housing is closed at a first end by a cylinder cover movable by means of a first drive device and having a cover circumferential surface, such that a combustion chamber is formed between the working piston and the cylinder cover, wherein a slide arrangement, which can be actuated by a second drive device, is provided for opening and closing combustion air inlet openings and exhaust gas outlet openings arranged in the cylinder housing. Furthermore, the invention relates to an internal combustion engine with such a cylinder arrangement, wherein the cylinder cover is movably arranged such that an overlap in the radial direction of the cover circumferential surface with the combustion air inlet openings and exhaust gas outlet openings is possible.

[0002] Modern internal combustion engines feature various valve train arrangements, incorporating mechanisms that allow for adjustments to valve lift, timing, and phase of exhaust and intake valves, as well as changes to the compression ratio, depending on the current operating conditions. Due to the design of the conventional internal combustion engine with camshaft-driven poppet valves in a single cylinder configuration, a multitude of complex valve train adjustment devices are required to perform these adjustments.

[0003] Particularly with regard to a simple change in the compression ratio in the combustion chamber of a cylinder of an internal combustion engine, it is known to use cylinder arrangements with a so-called Burt-McCollum slide valve in the internal combustion engine; see, for example, US 1,248,801 A or DE 199 54 438 A1. A similar cylinder arrangement is also known from GB 2,432,398 A.

[0004] With conventional cylinder arrangements that have a camshaft drive in a fixed cylinder head, a simple and cost-effective change in the compression ratio in the cylinder's combustion chamber is not possible. In this context, it is known from the prior art (see US 1,360,366 A and DE 689 14 852 T2) to arrange a cylinder cover so that it is movable, allowing an overlap in the radial direction of the cover's circumferential surface with the combustion air inlet and exhaust outlet openings.

[0005] The object of the invention is therefore to further develop an internal combustion engine with slide valve control in a simple and cost-effective manner so that it is suitable for modern engine concepts.

[0006] This problem is solved by providing a circumferential edge of the cylinder head surface facing the combustion chamber with a number of angled sections corresponding to the combustion air intake and exhaust gas outlet openings. This makes it possible to easily change the timing and the cross-sectional areas of the combustion air intake and exhaust gas outlets by axially shifting the cylinder head, in addition to changing the compression ratio. In particular, the timing of the combustion air intake and exhaust gas outlet openings can be varied by simply rotating the cylinder head without necessarily having to change the compression ratio in the combustion chamber.

[0007] It is particularly advantageous if the slide valve assembly is designed as a cylinder tube moving within the cylinder housing, the movement of which consists of a vertical translational component and a rotational component. Slide valve openings are formed in the cylinder tube, corresponding to the respective combustion air inlet and exhaust gas outlet openings, with the cylinder head being movably guided within the cylinder tube. This provides a very compact cylinder assembly, and the sealing measures can be minimized by using a cylinder tube. Since the second drive mechanism has a drive element that is operatively connected to the cylinder tube via a ball joint, the vertical translational and rotational component movements can be implemented simply. Advantageously, the drive element can be designed as a drive gear.

[0008] Advantageously, the first drive device comprises a screw drive. The drive can be mechanical, hydraulic, pneumatic and / or electrical.

[0009] It has proven advantageous to assign six pairs of combustion air inlet and exhaust gas outlet openings to six slide valve openings. Of course, this only describes one specific embodiment. The number, size, and geometry of the combustion air inlet and exhaust gas outlet openings depend, for example, on the bore-to-stroke ratio, the compression ratio, the combustion chamber shape, the height of a fire bridge, the control cross-section, and the control angle, etc. Furthermore, a larger or smaller number of pairs is also possible. It is also conceivable to provide a different number of combustion air inlet and exhaust gas outlet openings. For maximum control cross-sections with regard to performance and fuel consumption, openings arranged in pairs are used.Furthermore, a further variation of valve timing and valve cross-sections is made possible by the provision of first and second throttle elements in the intake and exhaust channels of the combustion air intake openings and exhaust gas outlet openings.

[0010] The problem is also solved by an internal combustion engine with a number of such cylinder arrangements. Here, the second drive unit can have a drive element designed as a drive gear, which is operatively connected to the cylinder tube via a ball joint, with the drive gear being connected to a crankshaft via an output gear. Advantageously, the drive gear is designed as an actuator that enables phase adjustment between the crankshaft and the valve assembly. However, the actuator can also be designed as a chain or belt pulley. The cylinder arrangements describe a boxer engine particularly advantageously, since the spacing of the cylinder arrangements is primarily defined by the crankshaft. However, any design / number of cylinders is also conceivable.

[0011] The invention is explained in more detail below with reference to a drawing, which shows: Fig. 1 a partially cutaway view of a cylinder arrangement according to the invention, Fig. 2 the cylinder arrangement from Fig. 1 without a cylinder housing, Fig. 3 a detailed view of an embodiment of a cylinder cover of the cylinder arrangement Fig. 1, Fig. 4a, Fig. 4b 4c Sectional views of the cylinder arrangement from Fig. 1 at the level of the section line IV - IV, and Fig. 5a, Fig. 5b 5c Sectional views of the cylinder arrangement from Fig. 1 at the level of the intersection line V - V.

[0012] Fig. Figure 1 shows a partially cutaway view of a cylinder arrangement 2 according to the invention. This cylinder arrangement 2 is particularly suitable for use in a so-called boxer engine (not shown), since large web widths are present between the cylinder assemblies 2. The cylinder arrangement 2 according to the invention has a cylinder housing 4, which is closed at a first end by a cylinder cover 6. Furthermore, a working piston 8 is provided in a known manner, such that a combustion chamber 10 is formed between the working piston 8 and the cylinder cover 6. A connecting rod 12 is connected to the working piston 8 in a known manner and is operatively connected to a crankshaft 14.

[0013] The cylinder cover 6 has a circumferential surface 16 that connects to a slide arrangement 18 of the cylinder housing 4, which is designed as a cylinder tube, and enables axial movement of the cylinder cover 6. For this purpose, a first drive device 20 is provided, of which in the present embodiment only a threaded drive 22 is shown. This drive is designed as a worm gear and has a thread 24, such that a rotational movement of a worm 26 causes a rotational movement of a worm wheel 28, so that the cylinder cover 6 is moved axially via the thread 24. With a cylinder cover 6 designed in this way, a change in the compression ratio is easily possible, since the combustion chamber 10 can be enlarged or reduced depending on certain operating conditions.

[0014] The cylinder tube 18 has slide openings 30 which correspond to combustion air inlet openings 32 and exhaust gas outlet openings 34 by means of a vertical translational and a rotational partial movement such that combustion air can be supplied to the combustion chamber 10 via inlet channels 36 and exhaust gas can be discharged via outlet channels 38 in a known manner. In the present embodiment, six pairs of combustion air inlet openings 32 and exhaust gas outlet openings 38 are assigned to six slide openings 30. As still under the Fig. As will be described in more detail in sections 4a to 4c and 5a to 5c, first throttle elements 40 and second throttle elements 42 are provided in the intake channels 36 and the exhaust channels 38, which serve to control the timing or control cross-sections.

[0015] The cylinder tube 18 is driven rotationally and translationally by a second drive unit 44. This second drive unit 44 comprises a drive element designed as a drive gear 46, which is connected to the cylinder tube 18 via an eccentrically mounted ball joint 48. The drive gear 46 is in turn operatively connected to a pinion 50 of the crankshaft 14. This second drive unit 44 design ensures that the opening and closing of the combustion air inlet openings 32 and exhaust gas outlet openings 34 can be synchronized with the crankshaft 14 in a known manner.

[0016] In the present embodiment, the drive gear 46 is also designed as a hydraulic actuator, which enables phase adjustment between the crankshaft 14 and the movement of the cylinder tube 18, and thus the opening and closing of the combustion air inlet openings 32 and exhaust gas outlet openings 38. The actuator 52 is specifically designed as a vane actuator, wherein a portion of the vanes 54 is connected to a shaft 56 leading to the ball joint 48, and the other portion of the vanes 58 is connected to the gear 46.

[0017] Fig. 2 shows the cylinder arrangement 2 according to the invention. Fig. 1 without the cylinder housing 4. The intake ports 36 are clearly visible, of which five are shown here. As described above, the first throttle element 40 is assigned to these intake ports 36. In this embodiment, this throttle element 40 has throttle openings 60, 62, 64 of different sizes, which enable a register-like opening and closing of the intake ports 36. Furthermore, the exhaust ports 38 are shown with second throttle elements 42, which also enable a register-like opening and closing of the exhaust ports 38.

[0018] Fig. Figure 3 shows a detailed view of a special embodiment of the cylinder cover 6. Fig. 1. For the sake of clarity, the cylinder tube 18 has been omitted in this illustration. Consequently, the combustion air inlet openings 32 and the exhaust gas outlet openings 34 are clearly visible. In this sectional view, three pairs of combustion air inlet openings 32 and exhaust gas outlet openings 34 are shown out of a total of six pairs. These openings 32 and 34 each have a straight control edge 66. This control edge, in conjunction with a lower edge 68 (see [reference to be added]), determines Fig. 1) The control processes “closing combustion air inlet openings” and “opening exhaust gas outlet openings” are carried out by the rotary and translational partial movements of the slide opening 30. This is achieved through a translational, axial movement of the cylinder cover 6, as described below. Fig. As described in Figure 1, in addition to reducing the size of the combustion chamber 10, the combustion air inlet openings 32 and exhaust gas outlet openings 34 can also be covered, thus enabling a variation of the valve timing. However, in order to be able to vary the valve timing independently of a change in the compression ratio, the present embodiment provides that the cylinder cover 6 has a circumferential edge 70 facing the combustion chamber 10, which has twelve angled segments 72. With a corresponding axial position of the cylinder cover 6, a rotation of the cylinder cover 6 allows partial covering of the valve timing edges 66, thereby enabling a variation of the valve timing. This simple rotation of the cylinder cover can be achieved by a suitable locking mechanism for the threaded drive 24, which is not shown.

[0019] As already indicated above, further variation of the timing and / or cross-sectional areas of the combustion air inlet openings 32 and the exhaust gas outlet openings 34 is possible by means of first and second throttle elements 40, 42. Fig. Figures 4a to 4c are sectional views of the cylinder arrangement 2 according to the invention. Fig. 1 at the level of section line IV-IV. They show the thoracic organ 40 in different positions. As already mentioned below. Fig. As explained in Figure 2, first throttle openings 60, 62, and 64 are provided, each of a different size. By rotating the first throttle element 40, these throttle openings 60, 62, and 64 can be aligned with corresponding combustion air inlet channels 36 such that a fluidic connection to the associated combustion air inlet opening 32 can be established. Thus, in Fig. 4a A position of the throttle element 40 is preset in which the openings 64 have been brought into a specific position such that exactly two inlet channels 36 are "open". By rotating the throttle element 40 to the left by means of a drive element (not shown), as in Fig. As shown in Figure 4b, four inlet channels 36 are opened. By further rotating the throttle element 40, the Fig. Position 4c has been reached in which all six inlet channels 36 are “open”.

[0020] The Fig. Figures 5a to 5c show the cylinder arrangement 2 according to the invention. Fig. 1 at the level of section line VI-VI. Here, a second throttle element 42 is arranged in each outlet channel 38, wherein these second throttle elements 42 are coupled to the first throttle element 40 such that a rotation in the maximum direction to the left opens all six outlet channels 38, as in Fig. Figure 5c shows that a maximum rotation of the throttling device 40° to the right shows the position shown in Figure 5c. Fig. 5a shows the position in which two outlet channels 38 are open. In the intermediate position, the Fig. The position shown in 5b with four open outlet channels 38 is reached.

Claims

[1] Cylinder arrangement for an internal combustion engine with a cylinder housing (4) in which a working piston (8) is provided, wherein the cylinder housing (4) is closed at a first end by a cylinder cover (6) movable by means of a first drive device (20), the cylinder cover having a cover circumferential surface (16), such that a combustion chamber (10) is formed between the working piston (8) and the cylinder cover (6), wherein a slide arrangement (18), which can be actuated by a second drive device (44), is provided for opening and closing combustion air inlet openings (32) and exhaust gas outlet openings (34) arranged in the cylinder housing (4), wherein the cylinder cover (6) is movably arranged such that an overlap in the radial direction of the cover circumferential surface (16) with the combustion air inlet openings (32) and exhaust gas outlet openings (34) is possible, characterized by, that a circumferential edge of the cover circumferential surface (16) directed towards the combustion chamber (10) has a number of angled sections (72) corresponding to the combustion air inlet openings (32) and exhaust gas outlet openings (34). [2] Cylinder arrangement according to claim 1, characterized by , that the slide arrangement (18) is designed as a cylinder tube moving in the cylinder housing (4), the movement of which consists of a vertical translational partial movement and a rotational partial movement, wherein slide openings (30) are formed in the cylinder tube (18) which correspond to the respective combustion air inlet openings (32) and exhaust gas outlet openings (34), wherein the cylinder cover (6) is movably guided in the cylinder tube (18). [3] Cylinder arrangement according to claim 2, characterized by , that the second drive device (44) has a drive element (46) which is operatively connected to the cylinder tube (18) via a ball joint (48). [4] Cylinder arrangement according to claim 3, characterized by , that the drive element (46) is designed as a drive gear. [5] Cylinder arrangement according to one of the preceding claims, characterized by , that the first drive device (20) has a screw drive (22). [6] Cylinder arrangement according to one of the preceding claims, characterized by , that six pairs of combustion air inlet openings (32) and exhaust gas outlet openings (34) are assigned to six slide openings (30). [7] Cylinder arrangement according to one of the preceding claims, characterized by , that first and second throttle elements (40, 42) are provided in the inlet and outlet channels (36, 38) of the combustion air inlet openings (32) and exhaust gas outlet openings (34). [8] Internal combustion engine with a number of cylinder arrangements (2) according to one of the preceding claims. [9] Internal combustion engine according to claim 8, characterized by, that the second drive device (44) has a drive element (46) which is designed as a drive gear and is operatively connected to the cylinder tube (18) via a ball joint (48), wherein the drive gear (46) is connected to a crankshaft (14) via an output gear (50). [10] Internal combustion engine according to claim 9, characterized by , that the drive gear (46) is designed as an actuator which enables phase adjustment between the crankshaft (14) and the slide arrangement (18). [11] Internal combustion engine according to any one of claims 8 to 10, characterized by , that the cylinder arrangements (2) describe a boxer engine.

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