WO2015173390A1 - Piston machine having a connecting-rod shank having a plurality of parts and connecting rod having such a connecting-rod shank - Google Patents

Abstract

The invention relates to a piston machine, comprising a crankshaft (15) and at least one connecting rod (17) supported on the crankshaft (15), wherein the connecting rod (17) has a small and a large connecting-rod bearing eye and wherein the connecting rod (17) has a connecting-rod shank (17.1). A compression piston (13), preferably a combustion-chamber piston, is supported by the connecting rod (17) by means of an eccentric (5) and can be adjusted by the connecting rod by means of an adjusting mechanism. The adjusting mechanism is supported by means of at least one supporting piston that can be displaced in a supporting cylinder (26) of the connecting rod (17), wherein the connecting-rod shank (17.1) comprises the supporting cylinder (26). At least one supporting-cylinder component (10), in particular designed as a sleeve, is attached to and/or in the connecting-rod shank (17.1), in which supporting-cylinder component the at least one supporting cylinder (26) is formed.

Description

 Piston engine with a connecting rod shaft with several parts and

Connecting rod with such a connecting rod shank

The present patent application claims the priority of German patent application 10 2014 007 050.6 of 15 May 2014, the content of which is hereby incorporated by reference into the subject matter of the present patent application.

The present invention relates to a variable compression stroke piston machine, also called "variable compression rate", abbreviated VCR piston engine, as well as a method for changing the compression stroke in a reciprocating engine. The piston engine is preferably an internal combustion engine, in particular a road vehicle, and therefore preferably has at least two cylinders with respective adjustment mechanism. At least one connecting rod of the piston engine has a connecting rod shaft with several parts. The need to be able to use piston engines optimally optimized in different areas, resulting in that among other things, the piston stroke should be changeable. As a result, the piston stroke can be varied to suit every application and the required operating state of the piston engine. If, therefore, the piston engine is used in operation in different areas, for example load areas, this can also be accommodated by adjusting the stroke and thus the resulting compaction.

In the prior art, there are a variety of different solutions for changing the compression of a piston engine during operation. Thus, DE-A-10 2007 040 699 discloses a magnetic solution. However, the invention is rather based on a piston engine, as disclosed in DE-A-10 2005 055 199. The contents of this document are I referred to the beginning of the disclosure of the invention, as from the publication of the fundamental structure of the piston engine and a possible union usable, special len connecting rod as well as the principle Verstel l method emerges.

Furthermore, it is known that the resulting in a VCR piston engine moments abut ^¬ zen by means of a support mechanism on an oil pad, which is held in Stützzyl Indians. It has been found out that these supporting cylinders are completely inexpensively manufactured on the connecting rod shaft, unfortunately, quite inexpensively. In addition, the Stützzyl represent inthe cozy one additional moving mass, which is uner ^¬ wishes for the kinematics of Kurbelwel le and connecting rods. The training of the Stützzyl indians in the connecting rod leads to manufacturing technology ing ing disadvantages, for example, to a high weight of the connecting rod due to the required M eanest Wandd icke to comply with forging and manufacturing tolerances, but also in a Feinbearbeitu ng the Zyl indian surface, for example By honing, which was difficult due to the Ausgestal ^¬ tion of Stützzyl inder as introduced into the connecting rod blind hole bore. The object of the present invention is to provide a piston machine with a connecting rod which is simpler to manufacture and with which improved performance can be achieved with a change in the compression ratio of a piston machine. The object is achieved by means of a piston engine with the features of claim 1. An ^¬ . Further advantageous embodiments and further developments emerge from the additional claims, ie the solutions which are each for themselves independent but also combined with the other solutions result in special solutions. In addition, one or more features of the present claims may be interchangeable by one or more features of other claims, the description, as well as the figures. The present The following claims form a first approach to the description of the invention without, however, limiting the invention itself.

In the most general form, the invention can be characterized in that the at least one support cylinder or at least one of the support cylinders of the adjustment mechanism of the connecting rod is formed in a support cylinder component which is mounted after its manufacture on the connecting rod or on the connecting rod shaft. This support cylinder component can have any desired outer contour, with the extent that the configuration of the outer contour is practically limited insofar as the connecting rod with the support cylinder component has to be accommodated in the cylinder crankcase. The support cylinder component may have one or more support cylinders. The cross-sectional area of the or a support cylinder can take any shape and in particular round, preferably circular or oval, elliptical or the like. be executed.

The advantage of the connecting rod achieved with the approach according to the invention is of a production engineering nature. It is much simpler and thus more cost-effective to design the support cylinder or, more precisely, the cylindrical cavity of the support cylinder in a component which is produced separately and thus separately from the connecting rod. It has been found that the formation of support cylinders directly in the connecting rod shaft is associated with considerable design and assembly and manufacturing technical effort. Much simpler contrast, it is to form the support cylinder separately from the connecting rod, then to mount the corresponding support cylinder component then on or in the connecting rod, preferably in a (partial) recess of the connecting rod or the connecting rod. It is particularly advantageous if a tube or a tube or a sleeve is used as the support cylinder component. Unless described in the following in connection with a sleeve individual features and advantages of the invention, these are not limited to the formation of a support cylinder component as a sleeve, but also apply generally to other embodiments of support cylinder components. The separate training of support cylinder and connecting rod also makes it possible to use a different material for the support cylinder than for the connecting rod. Thus, there is the advantage that a substantially lighter weight material can be used for the support cylinder component, as is the case for the connecting rod. Examples of lightweight materials are aluminum, an aluminum alloy, fiber composite materials, especially carbon fibers. The mechanical connection of support cylinder component and connecting rod is non-positively, positively and / or frictionally engaged. In order to achieve such mechanical connections of two components, there are numerous variants of joining techniques in the prior art which can also be used in the present invention.

According to a special embodiment of the invention, a piston engine with variable compression stroke is proposed with this, comprising - a crankshaft,

 at least one connecting rod rotatably mounted on the crankshaft, the connecting rod having a small and a large eye, and the connecting rod having a connecting rod shank,

 a compression piston arranged on the connecting rod, preferably a combustion chamber piston, which by means of an adjusting element, in particular

Eccentric and an adjustment system, preferably a Verstellgestänges, is eccentrically adjustable, wherein the adjustment system is supported by at least one support piston, which is movable in a support cylinder of the connecting rod shaft,

- Wherein the connecting rod shaft is formed in several parts with a base body, wherein the support cylinder is formed as a sleeve made separately from the connecting rod and connected to the base body.

In particular, the connecting rod shank can have at least two sleeves for two supporting cylinders which are connected to the basic body. The term sleeve here describes a tube or tube, which assumes the function of the support cylinder after the connection with the main body of the connecting rod shaft. The term tube or tube describes an elongated hollow body whose length is usually much larger than its diameter. The tube or tube is open in the axial direction, preferably at its two ends. But it can also be used a sleeve having a bottom. The floor can be closed, for example. The floor can also be provided with at least one passage opening, preferably an inlet and / or outlet opening. A further embodiment provides that at least one of the two end faces of a sleeve has a collar which extends inwardly and / or outwardly.

Due to the (preferred) embodiment of the support cylinder as a sleeve, which is mountable with the main body of the connecting rod shaft, the machining of a connecting rod in such a way that it has a support cylinder, can be simplified. For example, the use of a sleeve, the fine machining, such as honing, the cylinder surface can be simplified. For example, the fine machining can be carried out prior to the assembly of the sleeve on the connecting rod shaft, so that the fine machining does not have to take place in a blind hole, as would be the case if the support cylinder is formed directly integrated in the connecting rod shaft. Furthermore, the wall thickness of the support cylinder can be reduced by the use of a sleeve as a support cylinder, since no example tolerance-related wall thickness for forging and manufacturing tolerances must be kept as a one-piece connecting rod, whereby a lower weight is made possible. Instead, the required tolerances can already be taken into account in the manufacture of the sleeve for the or each support cylinder. Furthermore, due to the multi-part design of the connecting rod shaft according to the invention additional degrees of freedom with respect to the introduction of hydraulic holes in the connecting rod shaft, since the support cylinders are mounted only after the formation of the hydraulic holes on the connecting rod shank. As a result, the machining of the connecting rod can be simplified. Furthermore, it has been found that the sleeve can be provided as a prefabricated product with one or more ports or openings, for example in a side wall and / or in a collar or bottom. This makes it possible to ensure a supply and an outflow of, in particular, oil in the sleeve as a later support cylinder in the connecting rod. An embodiment of the invention, for example, provides that a conduit is attached to the sleeve, which is then connected, for example, with the connecting rod shank and a local connection, preferably after insertion of the sleeve in the connecting rod shank. In the piston engine, the support piston is supported in the support cylinder on a substantially incompressible medium. The medium is preferably a lubricant (such as oil), which is also used in the rest of the piston engine at ^¬ other place there. Preferably, the eccentric is arranged in the small connecting rod bearing eye, wherein the compression piston is mounted on the eccentric. The reciprocating engine may include one or more such connecting rods arranged on the crankshaft. In principle, an adjustment can take place as described in the above-mentioned DE-A-102005055 199 or also from DE-A-10 2012 014 917 or DE-A-10 2011 108 790, but in this respect also with respect to the adjustment and construction of the piston engine and the connecting rod together with the support cylinder and support ^¬ piston fully referenced in the context of the disclosure of this invention. The content of the three abovementioned publications is hereby incorporated by reference into the subject of the present application. While the support cylinder receives the medium on which the support piston is supported, the support piston divides the support cylinder cavity the contents of the support cylinder, for example, in a medium filled with the support space and in a displacement, in which the support piston moves when it to a Adjustment of the compression piston is to come. The adjustment is preferably not filled with the medium, but also embodiments are possible in which the adjustment is at least partially filled with the medium. The adjustment chamber is preferably filled with air. It is preferred that the support cylinder via a cohesive connection, in particular by welding, a non-positive connection, in particular by screwing, and / or by pressing with the connecting rod shaft is connectable.

The term cohesive connection here describes all compounds in which the connection partners are held together by atomic or molecular forces. These are non-detachable connections that can only be separated by destroying the connection means. The term welding describes a non-detachable joining of components using heat and / or pressure, with or without welding consumables. Other cohesive connections with which the support cylinder can be attached to the main body of the connecting rod shaft are soldering or gluing.

A frictional connection is created by the transmission of forces. These include e.g. Compressive forces or frictional forces. The cohesion of the non-positive connection is ensured by the force acting. Tensile forces can not be transmitted with non-positive connections, since both connection partners would break away from each other. Also screw connections are frictional connections in most cases, since the screws are tightened so tightly, at least are biased that hold the two connected parts by friction. Furthermore, can be created by a hot and / or cold treatment, a compound of sleeve and connecting rod.

Furthermore, the production of a connection of the / each support cylinder with the main body of the connecting rod shaft can be adapted to the particular manufacturing process used. In a preferred embodiment of the invention, the support cylinder of a different material than the connecting rod shaft can be produced. For example, the connecting rod shaft made of a metal, such. C70, microalloyed steels, sintered metals, tempering steels, titanium or cast iron. The sleeve is made for example of metal, carbon fiber, plastic, ceramic or a metal alloy. In this way, the choice of the material of the connecting rod shaft and the sleeve for the support cylinder of the piston engine of an internal combustion engine of a z. B. vehicle such as a road vehicle or a machine to be adapted. For example, the titanium connecting rod and the support cylinder may be made of a tempered steel to meet the requirements of the internal combustion engine piston engine.

Preferably, the support cylinder is made of aluminum. In this way, the weight can be reduced in the piston engine.

It is preferred that the support cylinder and the support piston form a targeted leakage path. In particular, the targeted leakage path can preferably be provided for the medium on which the support piston is supported in the support cylinder. It has been found that by means of the leakage path and its targeted setting, for example, it can be prevented that the support piston continues to dive over time, thereby resulting in an unintentional adjustment of the eccentricity. Another advantage may be, for example, that a venting is provided by means of the targeted leakage path. If, for example, foam, air bubbles or another compressible medium accumulate in the supporting medium, the targeted leakage path can be used to flow past in a gap between the support cylinder and the support piston. Preferably, the leakage path is only temporarily free. For example, the temporary release may be accompanied by a movement of the support piston. According to one embodiment of the invention, the leakage path is during a movement tion of the support piston in a first direction as well as in the opposite second direction respectively at least partially released. This may for example be the case during the entire movement or even during only a part of the movement. The leakage path can, for example, be continuously released at the same time. But it can also be partially or gradually, ie gradually released. There is also the possibility that the leakage path is subject to a certain arbitrariness with respect to its course between support piston and support cylinder. For example, it may depend on the movement in which way the leakage path occurs. The definition of the leakage path is in this case in particular by the geometry of the support cylinder, the support piston whose relative movement to each other in the axial and radial direction. A further embodiment, however, provides for the definition of the leakage path by means of a predetermined, fixed path along which the medium must flow. Also, both embodiments can be combined with respect to the leakage path. Thus, different areas between the support piston and the support cylinder can each define the leakage path differently. The above-described features of the leakage path are not limited to the realization of a support cylinder on a connecting rod according to the invention and are insofar independent and applicable to all conrod constructions with support cylinder and piston. A further embodiment of the invention, which can be used together as well as independently of the other described embodiments, provides a piston machine in which the support piston is provided without a separate sealing element between the support piston and support cylinder and moves without sealing element along the support cylinder.

An advantage of using a support piston without a sealing element is, for example, a minimization of the friction between the support piston and the support cylinder. This For example, is advantageous in terms of switching times, especially at low speeds, especially in the direction of "high compression", ie high compression ratio, since only small moment of inertia, caused by the back and forth movement of the compression piston, act on the Adjusting system is instructed without a supporting motive force for the adjustment of the compression bolt.

A preferred design of the defined leakage path is for example as follows:

For a gap leakage of an eccentric annular gap, the following mathematical relationship is assumed:

with dm - nittil. Diameter of the D ichtrteie, h - gap height, l - long dr sealing point, n ~ dyn. Viskösit _r e = eccentricity.

A diameter difference between the support piston and the support cylinder is sized so that the leakage remains very low, but it can not come to a jamming of the piston. The movement of the support piston will change the leakage path. By a suitable design of the fit between support piston and support cylinder manages to be able to do without a separate sealant between support piston and support cylinder.

According to one embodiment, it is provided that a collapse of the Stützzylin- ders by 1% to 2% or more based on the total travel, which is equal to the stroke of the support mechanism, can be accepted. It has been found, for example, that a collapse of approximately 0.3 mm with a support piston stroke of approximately 30 mm does not lead to such a falsification of the adjustment. Position of the compression piston leads, which finally ends in permanent repetition in a complete malposition of the compression piston.

Preference is given to a diameter difference between the support piston and Stützzylin- this, for example, on the gas force side about 0, 1% to 0.2% based on the nominal diameter of the support cylinder. The gas-power side is in this case the one which, as a result of the combustion and expansion in the case of a combustion engine, acts as a pressure force on the compression piston and thus on the support piston as an adjusting force. For example, for a diameter of 14 mm, a diametrical clearance of about 0.025 mm is provided.

According to one embodiment of the invention, it is provided, for example, that support piston and support cylinder are selectively paired by means of a classification. The classification may, for example, be accompanied by an accurate surface measurement and contour determination that allows to establish those cylinder / piston pairs that actually complies with the corresponding diameter difference along the travel of the support piston. The support cylinder surface must be suitable for the shape and surface of a sealing concept, which is preferably honed, finely-spun or ground. Laser surface processing is also possible.

A further development provides that a larger clearance is accepted for a cylinder / piston support unit on the mass force side, since here usually a lower oil pressure level is present. By "mass force side" is meant that support unit that absorbs forces resulting from mass moments of inertia of the forward and backward moving compression piston. It is further proposed a piston engine, wherein the connecting rod has a first and a second support piston, which have a different diameter in relation to each other, wherein the first Support piston has a smaller diameter and between the first support piston and the first support cylinder associated therewith, a first gap is present, which is greater than that between the second support piston and the second support cylinder associated therewith.

Such an arrangement may preferably be adapted to the difference in magnitude of the moments acting on the mass-flow side and the gas-side, in particular on the pressures acting thereby. Preferably, the smaller diameter is located on the side at which lower pressures act.

According to a further embodiment of the invention it is provided that in the main body of the connecting rod shaft, a first sleeve and a second sleeve are arranged on ^¬ and each form a support cylinder of the adjustment, wherein the first sleeve has a different inner diameter than the second sleeve. A further embodiment provides that a first sleeve and a second sleeve are arranged in the main body of the connecting rod shaft and each ^¬ Weil form a support cylinder of the adjustment, wherein the first sleeve ei ^¬ nen other outer diameter than the second sleeve. A further embodiment provides that the first sleeve has a different inner diameter than the second sleeve, but an outer diameter of the first sleeve coincides with an outer diameter of the second sleeve.

The combustion peak pressure and the mass forces in the crank mechanism (kinematic system, in particular from crankshaft, connecting rod and possibly flywheel) are reflected by the geometric conditions such as eccentricity, lever length, force application angle of the support rods, support piston diameter in the support cylinder pressures again. On the gas-side support cylinder oil pressures of 300 bar and more can act (eg over 400 bar). A preferred embodiment provides for the use of a defined leakage path without a sealing element between the support piston and the support cylinder, wherein pressures of over 400 bar can occur in the support cylinder. The support piston height is in the above relationship to the design comparatively only a linear. Therefore, it is of less value than the diametrical game. Nevertheless, the support piston height should be as large as possible, with a height between about 0.8 to 1.5 times the piston diameter has proven to be advantageous.

A further embodiment of the invention provides that at least the support piston and / or the sleeve can be coated on its inner circumference, for example with graphite, in order to be able to minimize the play between the support piston and the support cylinder by means of lubrication. Preferably, a piston engine is proposed, in which the support piston has a coating on its circumference, preferably an inlet coating, by means of which the support piston must first be stuffed under pressure into the support cylinder and which wears down during operation, thereby creating a gap between the piston Support piston and the support cylinder to provide, and / or preferably a protective coating, which has a higher abrasion resistance than the actual material of the support piston and / or the sleeve.

For example, higher manufacturing tolerances can be planned for such an embodiment, since the enema coating can function as a sacrificial layer, thus bridging the clearance.

A further embodiment of the piston engine provides that the support piston is provided with a sealing element which allows a targeted leakage, preferably by means of a division in a joint area of the sealing element and an axial clearance between a height of the sealing element on the one hand and on the other hand, a groove height of a groove in which the sealing element is arranged. A sealing element, which can provide a targeted leakage, for example, provides a sealing ring made of plastic, which is diagonally divided at a joint, which is needed for installation. Through the angle of the push and the axial Game, ie sealing ring height to slot height, a leakage current can be adjusted by this form of defining the leakage path, for example for venting. A further embodiment of the invention provides that the support piston along its outer circumference has one or more at least partially circumferential grooves. Preferably, the support piston can be designed on the outside with small grooves. These provide an additional sealing effect, since the leakage current swirls here.

A further development, which may also be independent of other embodiments, provides a piston engine, in which the support piston is connected to an element of the Verstellgestänges means of a ball and socket connection. The connection between a support rod of the adjustment rod and the support piston is preferably designed as a ball-and-socket joint. This can be done in particular in the form of a Bischofsmützen contour. As a result, the effective sealing length is not interrupted by a bolt. One embodiment provides for this that the piston engine has a support piston with an inner contour which is spherical, on which a head of the ball-and-socket joint rests. The pan supports can be, for example friction-reducing ^¬ be coated.

To keep the Hertzian stresses as low as possible, the following is proposed for the ball-and-socket connection:

- The ball diameter should be as large as possible, i. the contact length of the line contact should be maximized;

 However, the support piston must not become so thin-walled that deformations lead to jamming;

the ratio of ball diameter to supporting piston diameter should preferably be in a range from 0.70 to 0.85. Furthermore, it is preferred if the frontal outer contour of the support piston has, which is crowned. The support piston contour can be performed crowned, whereby the clamping tendency is reduced in small games. A further embodiment provides that the piston engine has at least one support piston with a geometry that allows expansion of the support piston upon pressure application via the Verstellgestänge, wherein the gap distance between the inner surface of the support cylinder and an opposite outer surface of the support piston is reduced.

In conjunction with the ball head, an additional vent hole can be introduced into the piston, since the ball seat under pressure has a sealing effect. For this case, for example, it is provided that no air can be sucked in "backwards". This is preferably achieved by the fact that at the times in the working cycle of the piston engine, in which a tensile force acts on the support rods, in each case the medium pressure in the support cylinders is greater than the pressure in the crankcase.

Another embodiment provides a support piston with a continuous vent hole, one end of which opens into a region of a piston face of the support piston in a first side of the support cylinder and the other end opens into a second side of the support cylinder, wherein the first and the second side of the support cylinder separated from each other by the support piston.

Preferably, the piston engine is used in the form of an internal combustion engine, in particular a road vehicle, wherein the internal combustion engine has an adjustable stroke for compression change during operation using at least one adjustable by means of an eccentric combustion chamber piston, the adjustment by means of Verstellgestänges as a result of acting on the combustion chamber piston gas and / or ground forces is executable. It is preferred that the support piston has a coating on its circumference, preferably an enema coating, by means of which the support piston must first be introduced under pressure into the support cylinder and wears off during operation to form a gap between the support piston and the valve To provide Stützzyl inder, and / or preferably a protective coating, which has a higher abrasion resistance than the actual material of the Stützkol bens.

The proposed piston engine preferably has a configuration in which the connecting rod has a first and a second support piston, which are connected to each other via the Verstellgestänge and an eccentric which carries the combustion chamber or compression piston, wherein the first support piston with the Verstel lgestänge via a ball head Verbind union and the second Stützkol ben with the Verstel lgestänge connected via a bolt connection ung.

According to a further aspect of the invention, which is preferably executable by way of example in one of the above-proposed piston engines, a method for adjusting a compression of a piston engine by means of an adjustable piston stroke is proposed, wherein the adjustment of the piston stroke is utilized acting mass and / or gas forces acting on an adjusting linkage and a support piston arranged thereon, wherein the support piston moves in the in the Stützzyl inder- component formed Stützzyl Indian, wherein oil of the piston engine as a damping medium of the movement of the support piston in the Counteracts Stützzyl indians.

A further embodiment of the invention provides that at least one sleeve, preferably both sleeves, each forming a support cylinder, is exchangeable in the main body of the connecting rod shaft. A further embodiment provides that the or each sleeve is only partially embedded in the main body of the connecting rod shaft. Preferably, the sleeve is at least partially released on its outer circumference and not from the base body enclosed. One embodiment provides that the sleeve is completely enclosed at one end by the main body, but not at the other end. H ierbei may for example be provided that t he H ülse along a ^¬ ers th region completely d urch the base body Shift lossen is, however, not in a second region. An embodiment provides that the sleeve along at least part of the outer circumference D is umsch Lase by the body umsch. On the other hand, another embodiment provides that the sleeve protrudes from the main body in an axial section (over its entire circumference or a part thereof). Preferably, between see the support piston and the Stützzyl inder the oil can flow along a targeted leakage path.

A further embodiment of an idea of the invention relates to a method, which can preferably also be used together with the above method, for adjusting a compaction of a piston machine, preferably with a configuration of a piston described above, wherein the adjustment of the Piston strokes taking advantage of acting mass and / or gas forces acting on a Verstellgestänge and a support piston arranged thereon, the support piston moves in a Stützzyl inder, with oil of the piston engine as a damping medium movement of the Stützkol bens in the Stützzyl indians counteracts, wherein at a breakaway torque of 0.7 Nm or less, a friction between the support piston and Stützzyl overcome and an adjustment of the support piston support cylinder in the support cylinder.

Preferably, the breakaway torque on the support piston during the first operation of the Kol benmaschine higher and builds up with prolonged N utzu ng the piston engine slowly from. In particular, a stiffness, for example, of a sealing element can decrease by an acting pressure in Stützzyl indians. At low speeds, such as 1000 rpm, the breakaway torque at top dead center (TDC) may be about 0.7 Nm. The invention further relates to a method for producing a connecting rod with a crankshaft for a piston engine described above, wherein the connecting rod has a small (piston bearing) and a large (stroke bearing) eye and a connecting rod shaft comprising at least the following steps:

- Providing a connecting rod shaft, wherein the connecting rod shaft comprises a base body;

 Providing at least one sleeve; and

 Connecting the sleeve to the main body. In this way, a connecting rod shank can be provided with at least one support cylinder consisting of several parts for a piston engine.

The connection can be made for example by mounting the at least one sleeve on the main body of the connecting rod shaft. , For example, the sleeve can be screwed. The mounting can be done manually as well as by machine

The embodiment of the invention with two support cylinders is effectively synonymous with an embodiment in which a support cylinder is provided with double-acting support piston. On both sides of the support piston form quasi two working spaces, which act as two support cylinders, each with a support piston. In that regard, it is also conceivable according to the invention that the support cylinder component comprises a support cylinder with a double-acting support piston.

Further advantageous embodiments and developments will become apparent from the following figures. The embodiments which emerge from the figures in each case serve to explain the invention, without wishing to restrict it. Rather, one or more embodiments can be combined with one another, as can one or more features from a figure or the above description with one or more features from an alternative embodiment. their figure or the above description are linked to further embodiments. Show it:

1 shows an embodiment of a connecting rod shaft by means of which an adjustable change of a compression ratio of a piston engine in a reciprocating internal combustion engine is made possible,

2 shows an embodiment of a support piston with a spherical head connection,

3 shows a further embodiment of a ball-and-socket joint,

4 shows an additional embodiment of a support cylinder, and FIG. 5 shows a last embodiment of an at least 2-stage VCR system based on the principle of a variable effective connecting rod length.

1 shows an embodiment by means of which an adjustable change of a compression ratio in a piston engine 1 in the form of a Hubkol- benverbrennungskraftmaschine with a 4 indicated housing he ^¬ is possible, wherein optionally at least one connecting rod 17 has a connecting rod 17.1, on / in the two support cylinders 26 in the form of sleeves 26.1, 26.2 are attached. The sleeves 26.1, 26.2 are pressed in this embodiment in the connecting rod shank 17.1. In this embodiment, the sleeves 26.1, 26.2 for the support cylinders are made of a different material than the connecting rod shaft 17.1; For example, the connecting rod 17.1 made of a cast steel and the sleeves 26.1, 26.2 of the support cylinder made of aluminum.

The connecting rod 17 has a large connecting rod bearing eye 3, via which the connecting rod 17 is mounted on the crankshaft 15, and a small connecting rod bearing eye 2, which carries the compression piston 13 via a pin 14. In the small connecting rod eye 2, in turn, an eccentric 5 is arranged, which is rotatably mounted. Of the Eccentric 5 has a bore 18 for receiving the piston pin 14. On its outer surface, the eccentric 5 has a toothing 19. About this toothing 19 of the eccentric 5 is positively connected to a lever system 20, which acts as a support mechanism and preferably also as a backstop. The lever system 20 has a pivot lever 16 which is positively connected to the teeth 19 of the eccentric 5 and the Ex ^¬ center 5 pivoted if necessary. The pivot lever 16 and the eccentric 5 form an adjusting element 11 for adjusting the compression piston 13. Kinematically, the adjusting element 11 has two levers 21, 22 which extend from the pivot point 9 of the adjusting element 11 and of which the lever 22 is longer than the one Lever 21. About its first lever 21 and the second lever 22, the pivot lever 16 is supported on a support unit 7, as will be described below. From Fig. 1 it can be seen further that the lever system 20 is axially guided. Furthermore, the lever system 20 connecting joints 24 between the pivot lever 16 and on the two levers 21, 22 on. About the connecting joints 24 (piston) rods 25.1 and 25.2 articulated. In the connecting rod 17 turn 17.1 support cylinder components 10 in the form of, for example, sleeves 26.1, 26.2 are arranged as a support cylinder 26 in the connecting rod shank. In the sleeves 26.1, 26.2 support piston 27 are guided, on each of which the rods 25.1, 25.2 are articulated. In a hervorgeru ^¬ by gas or inertial forces and allowed rotation of the eccentric 5, the two support piston 27.1, 27.2 in the respective support cylinders 26 (sleeves 26.1, 26.2) move. The support cylinders 26 in the connecting rod 17 have channels 28.1, 28.2, which each lead ^¬ Weil to a working space 29.1, 29.2 in the sleeves 26.1, 26.2 (support cylinder 26). At the big connecting rod bearing eye 3 connecting rod bearing shells 30 are angeord ^¬ net. Since the bearing shells 30 are provided with a circumferential groove, which is in communication with an oil supply via the crankshaft, is in the groove at any time to an oil pressure. Incidentally, the course of movement with a change in the compression ratio is more closely explained in the DE-A 10 2005 055 199, to which reference is hereby made and which therefore belongs to the subject of the present patent application.

The operation of the connecting rod 17 for setting a different compression ratio is explained below using the example of setting a low compression ratio. If a low compression ratio is desired during engine operation, a multi-way valve, for example, is brought into a position in which the two channels for the outflow of oil into the working space 29.1 and for the inflow of oil into the other working space 29.2 are released. In those engine phases in which, as a result of the combustion, gas pressure forces on the connecting rod 17 and moves in the direction of the crankshaft (ie downwards), the support piston 27.1 is pushed further into the sleeve 26.1, so that the oil in the first working space 29.1 is displaced into the channel 28.1. At the same time, the support piston 27.2 moves and sucks in the second working space 29.2 via the channel 28.2. The eccentric 5 can thus gradually in the direction of arrow 37 in FIG. 1 twist. This opposite displacement of the two support pistons 27.1, 27.2 is automatically terminated when the lifting movement of the connecting rod 17 reverses and the connecting rod moves back up. Now acts on the second support piston 27.2 a force that results from the inertia of the "accelerated" mass of the compression piston, the eccentric 5 and the lever system 20. Since the channel 28.2 is not released (the valve, not shown, is closed), the support piston 27.2 is supported on the oil volume in the working space 29.2. A rotation of the eccentric 5 in the opposite direction is not possible because the first working space 29.1 is closed and the first support piston 27.1 can not submerge.

At the next reversal of the connecting rod movement, the mass force "pulls" on the second support piston 27.2, so that oil again enters the working space 29.2. At the same time displaces the first support piston 27.1 oil from the working space

29.1. This stepwise opposing movement of the two support pistons 27.1, 27.2 leads to the extent possibly over several cycles of the piston engine Verdi tion of the eccentric from a Verd reh- Endstel ment, in which one of the two support piston 27 at the bottom of the associated Stützzyl inder

26 is located, while the other support piston from the bottom of "his" support cylinder is spaced, in the other Verd reh- Endstel ment, in which the situation with respect to the respectively occupied by the support piston position exactly opposite to the previously described.

For adjustment of the ung Dilute ichtungsverhältnisses from a (or the) small ^¬ ren value to a (or the) g rößeren value is ensured that only when ben on the Stützkol "pulled" is 27.2 (which, due to the mass inertia with the beginning of the suction of air into the combustion chamber is the case), an adjustment of the lever system 20 and thus a Verd re-tion of the eccentric against the arrow 37 of FIG. 1 takes place in the direction of the eccentric position shown there. Depending Ausleg ung one or more hyd Raul regard Wi resistors and a size of the engine forces, therefore, an immersion ^¬ process may extend over several working cycles. The hyd raul ische resistance is preferably formed by a connecting line or d by a throttle located therein. This embodiment of a method is only exemplary, as is the on ^¬ construction of the connecting rod, and not restrictive. The Stützkol ben used have a defined leakage path, the vergößert here in relation to the first support piston 27.1 vergöß in the form of a special seal design of a sealing element is here.

Fig. 2 shows an exemplary embodiment of a Stützkol bens 27 with a ball head connection 40, wherein in the support cylinder 26 and the Stützkol ben

27 is a vent hole 42 angeord net. Fig. 3 shows another exemplary embodiment of a Kugelkopfverbind 40 of a Stützzyl inder 26, wherein the support cylinder 26 has a bal-shaped end face ^¬ . Fig. 4 shows an embodiment of a Stützzyl inder 26, which has a contour ^¬ , which leads at pressure to Spaltvereng between support cylinder 26 and support piston 27 d urch expansion of the support piston. The contour on the front side with its preferably peripheral recess 44 makes it possible for the stiffness of the support piston 27 to be specifically weakened at the front end on the outer circumference so that the oil pressure leads to a small deformation of the support piston 27 and thus the play reduced, wherein the reduction d occurs depending on ig. Fig. 5 shows, in an exemplary embodiment, an at least 2-stage VCR system based on the principle of a variable connecting rod length. For this purpose, an eccentric for receiving the piston pin in the small Pleuellagerauge is pivotally mounted. The gas and mass forces acting on the piston lead to a torque acting on the eccentric. A Abstützmechana-, comprising a lever, two support rods and two Stützkol ben, is connected to the eccentric and transmits d this moment on two introduced in the connecting rod Stützzyl indians. The support cylinder pointing in the direction of eccentricity, d. H . the further spaced from the pivot point of the eccentric of the two support cylinders takes over the support of the resulting from the gas forces moments, the other support cylinder equivalent equivalent to the inertia forces. Hereinafter, the two sides of the connecting rod are called "GKS" (gas force side) and "M KS" (mass force side). Both Stützzyl indians can be filled with oil if necessary. A check valve associated with each support cylinder allows the intermittent supply of oil and prevents oil from flowing off and vice versa. For example, a 3/2-way switching valve can be opened either the G KS or the M KS. This combination of check valves and switching valves forms a hyd raul freewheel whose direction is selectable. In the case of the selected Stel development of a high compression ratio, also called "s_h igh", based on the eccentric mathematically positive acting moments based on the oil column of G KS. The mathematically negative moments originating from the inertial forces are in this position via a direct, metallic contact of the MBS support piston transferred to the connecting rod. In the position for a cu ^¬-engine compression ratio, abbreviated "ε_Ιονν" the circumstances are ver ^¬ exchanges. A positive side effect for the "ε_Ιονν" position is that the gas forces, which are usually higher in this position, are no longer supported on the oil column and thus the oil pressure in the support cylinder remains at a lower level. The adjustment system of such a support system is thus provided with a first and second support piston, the two support pistons having different connections to the respective support rod: the one support piston having a ball and socket connection has a smaller support piston diameter than the other support piston having a bolted connection , The lever transmits the torque resulting from the eccentricity, which can be due to the ever increasing combustion peak pressures of today's highly-charged gasoline engines at more than 300 Nm, on the support rods. The ratio formed by the relationship between eccentricity and lever length, for example, is approximately 1/10. In conjunction with the dependent of the respective ε-position force application angle between support rods and levers so supporting forces that can be quite up to lOkN arise. The preferred lever-side hinge type is a classic bolt. This is firmly connected with a structure designed as a fork at the upper end of the support rods and stored in the lever. The surface pressures occurring here, for example, up to 200 MPa. The hinge point to the support piston can also be designed as a bolt bearing. The other preferred embodiment provides a ball joint. On the one hand, this allows a smaller support diameter, which has two positive side effects for the MKS, whose forces are at a significantly lower level than on the GKS:

 The connecting rod becomes lighter as the structure around the support cylinder can be tightened accordingly.

 Due to the smallest possible MKS piston diameter results due to the oil pressure a small but steadily acting moment on the

Eccentric towards s_high. This has a favorable effect on the switching behavior at low engine speeds, since the senkräften resulting, necessary for the adjustment moments are correspondingly low. On the other hand, the omission of a bolt allows the utilization of the entire support piston height as a sealing length. This is advantageous in terms of dispensing with additional Dichtelemen- te, since the system tolerates a certain leakage - for example, affects at a lever ratio of about 1/10, a leakage-induced sinking of the support piston of eg 0.1 mm on the effective connecting rod length only about 10 m off, but if it is too large, the Verdich ^¬ tion ratio unintentionally "drift". Likewise, the sealing elements generate an additional frictional torque during an adjustment process. Thus, an adjustment can be initiated only if this moment is overcome. The sealing element may thus also comprise a sealing system consisting of an O-ring and an overlying rectangular ring made of a PTFE composite material. Its friction has, for example, a breakaway torque of the eccentric of 0.5 Nm to 0.8 Nm result. This low-appearing torque level is only slightly exceeded at low speeds for a circuit in the direction "s_high" because of the very low mass forces in these operating points. Since only a slight excess torque in turn is associated with losses in the switching speed, the above measures for these extreme operating points are therefore of great importance.

The invention can be further alternatively rewrite by one of said following feature groups, in which the characteristic groups with- any are combined with each other and individual features of one Merkmalsgrup ^¬ pe with one or more features of one or more other groups of features and / or described one or more of the above- Embodiments can be combined. Comprising 1. piston engine

a crankshaft, at least one connecting rod 17 rotatably mounted on the crankshaft, wherein the connecting rod 17 has a small 2 and a large eye 3 and wherein the connecting rod 17 has a connecting rod shaft 17.1,

 a compression piston arranged on the connecting rod 17, preferably a combustion chamber piston, which is eccentrically adjustable by means of an eccentric 5 and an adjustment system, preferably an adjusting linkage, wherein the adjustment system by means of at least one movable in a support cylinder of the connecting rod 17 support piston 27, 27.1, 27.2 itself supported, wherein the connecting rod shaft 17.1 has the support cylinder,

characterized in that

 the connecting rod shaft 17.1 is formed in several parts with a base body, wherein the support cylinder is connected as a separate sleeve 26.1, 26.2 with the base body.

Piston engine according to item 1, wherein the support cylinder via a cohesive connection, in particular welding, a non-positive connection, in particular screwing, and / or is connected by compression with the connecting rod shaft 17.1.

Piston machine according to item 1 or 2, wherein the support cylinder is made of a different material than the connecting rod shaft 17.1.

Piston machine according to item 3, wherein the support cylinder is made of aluminum.

Piston machine according to one of the preceding figures, wherein the support cylinder and the support piston 27, 27.1, 27.2 form a targeted leakage path.

Piston machine according to paragraph 5, wherein the support piston 27, 27.1, 27.2 without a separate sealing element between support piston 27, 27.1, 27.2 and Support cylinder is provided and moves without sealing element along the support cylinder.

Piston machine according to item 5 or 6, wherein the support piston 27, 27.1, 27.2 is provided with a sealing element which allows a targeted leakage, preferably by means of a division in a joint region of the sealing element and an axial clearance between a height of the sealing element on the one hand and on the other hand, a groove height a groove in which the sealing element is arranged.

Piston machine according to one of the preceding figures, wherein a first sleeve 26.1 and a second sleeve 26.2 are arranged in the main body of the connecting rod shaft 17.1 and each form a support cylinder of the adjustment, wherein the first sleeve 26.1 has a different inner diameter than the second sleeve 26.2.

Piston engine according to one of the preceding figures, wherein a first sleeve 26.1 and a second sleeve 26.2 are arranged in the main body of the connecting rod shaft 17.1 and each form a support cylinder of the adjustment, wherein the first sleeve 26.1 has a different outer diameter than the second sleeve 26.2.

Piston machine according to one of the preceding figures, wherein at least one sleeve 26.1, 26.2 is arranged interchangeable in the main body of the connecting rod shaft 17.1.

Piston engine according to one of the preceding figures in the form of an internal combustion engine of a road vehicle, wherein the internal combustion engine has an adjustable stroke for compression change during operation using the at least one eccentrically adjustable combustion chamber piston, wherein at least one eccentric see adjustment by acting gas and / or inertial forces on the at least one Verstellgestänge executable. Piston engine according to one of the preceding figures, wherein the connecting rod 17 has a first 27.1 and a second support piston 27.2, which are connected to each other via the Verstellgestänge, wherein the first support piston 27.1 with the Verstellgestänge a ball-head connection and the second support piston 27.2 with the Verstellgestänge is connected via a bolt connection, wherein the relative to each other have a different diameter, wherein the first support piston 27.1 has a smaller diameter and between the first support piston 27.1 and the first support cylinder associated therewith 26.1, a first gap is present, which is greater than that between the second support piston 27.2 and the associated second support cylinder 26.2. Piston engine according to one of the preceding claims, characterized in that the support piston 27, 27.1, 27.2 on its circumference and / or the sleeve 26.1, 26.2 as a support cylinder on its inner circumference has a coating, preferably an inlet coating, by means of the support piston first under pressure in the support cylinder has to be stuffed into it and wears down during operation to thereby create a gap between the support piston 27, 27.1, 27.2 and the support cylinder, and / or preferably a protective coating which has a higher abrasion resistance than the actual material of the support piston 27th , 27.1, 27.2 and / or the sleeve 26.1, 26.2. Method for adjusting a compression of a piston engine preferably according to one of claims 5 to 13, by means of an eccentrically adjustable piston stroke, wherein the adjustment of the piston stroke takes place by utilizing effective mass and / or gas forces, which thereto on a Verstellgestänge and a support piston arranged thereon 27th , 27.1, 27.2 act, wherein the support piston 27, 27.1, 27.2 moves in a support cylinder formed by an inserted sleeve 26.1, 26.2, wherein counteracts in the support cylinder oil of the piston engine as a damping medium movement of the support piston 27, 27.1, 27.2.

15. A method for producing a crankshaft rotatably connectable connecting rod 17 for a piston engine preferably according to one of claims 1 to 13, wherein the connecting rod 17 has a small 2 and a large eye 3 and a connecting rod 17.1, comprising at least the following steps:

 Providing a connecting rod shaft 17.1, wherein the connecting rod shaft 17.1 comprises a base body;

 Providing at least one sleeve 26.1, 26.2; and

 Connecting the sleeve 26.1, 26.2 with the main body.

In the above general and figure description are in addition to the aspect that the at least one support cylinder or if desired each support cylinder of the adjustment is formed as a sleeve with either bottom wall or without bottom wall, also described the aspects that with several support cylinders these different Innendurchmes ^{¬ can have} ser and that a deliberate leakage for the piston of a support cylinder is provided. Finally, it is then also described how the articulation of the piston rod can be done on the support piston, namely for example by a ball joint. It should be pointed out at this point that these various aspects belong to the invention or define an invention in any combination of individual aspects or even every aspect. In other words, each aspect forms an invention per se, wherein these individual aspects of the invention can be implemented in any combination. REFERENCE LIST Piston engine

small connecting rod eye

big connecting rod eye

eccentric

support unit

pivot point

Support cylinder component

Adjustment element for the compression piston. Compression piston

piston pin

crankshaft

pivoting lever

pleuel

connecting rod shaft

drilling

gearing

Lever system or adjustment mechanism first lever

second lever

connecting joints

rods

supporting cylinders

Sleeve as a support cylinder

Sleeve as a support cylinder

support piston

support piston

support piston

channel

channel

channel working space

 working space

 working space

 connecting rod

 arrow

 Ball head connection

vent hole

 Recess in the support piston

Claims

Piston engine with  a crankshaft (15),  at least one connecting rod (17) which can be moved by the crankshaft (15) and which has a connecting rod shaft (17.1),  one of the connecting rod (17) carried compression piston (13), preferably a combustion chamber piston which is adjustable by means of an eccentric (5) and an adjusting mechanism (20),  wherein the adjusting mechanism (20) has at least one support piston (27, 27.1, 27.2) movable in a support cylinder (26) of the connecting rod (17), which is arranged in a support cylinder (26) located in the connecting rod shaft (17.1),  characterized,  a support cylinder component (10) is attached and / or inserted on and / or in the connecting rod shaft (17.1), and  in that the at least one support cylinder (26) is formed in the support cylinder component (10). Piston engine according to claim 1, characterized in that the support cylinder component (10) via a material connection, in particular welding, soldering, gluing and / or by a non-positive connection, in particular screwing, riveting and / or by a frictional connection such. Compression with the connecting rod shaft (17.1) is connected. Piston engine according to claim 1 or 2, characterized in that the support cylinder component (10) has a different material than the connecting rod shank (17.1). 4. Piston engine according to claim 3, characterized in that the support cylinder component (10) comprises aluminum or carbon fiber. 5. Piston engine according to one of the preceding claims, characterized in that the at least one support cylinder component (10) in the connecting rod shaft (17.1) is arranged interchangeable. 6. Piston engine according to one of claims 1 to 5, characterized in that a second support cylinder (26) is provided with a support piston arranged in this (27.2) and that the second support cylinder (26) in a further support cylinder component or together with the other support cylinder (26) is formed in one and the same Stützzylinder- component. 7. Piston engine according to one of the preceding claims in the form of an internal combustion engine for a road vehicle, wherein the internal combustion engine has an adjustable stroke for compression change during operation using the at least one adjustable combustion chamber piston, wherein at least one adjustment means of the compression piston (13) on the at least a Verstellgestänge acting gas and / or inertial forces is executable. 8. Piston engine according to one of the preceding claims, characterized in that the connecting rod (17) has a first support cylinder (26) with a first support piston (27.1) and a second support cylinder (26) with a second support piston (27.2), wherein the two Supporting piston (27.1, 27.2) via a reciprocating piston adjusting element, in particular an eccentric (5) of the adjusting mechanism are coupled together. 9. Piston engine according to claim 7, characterized in that the first support piston (27.1) is connected to the Verstellgestänge a ball-head connection and the second support piston (27.2) with the Verstellgestänge via a bolt connection. 10. Piston engine according to claim 8 or 9, characterized in that the two support pistons (27.1, 27.2) in relation to each other have different diameters, wherein the first support piston (27.1) has a smaller diameter. 11. Piston engine according to one of claims 7 to 9, characterized in that between the first support piston (27.1) and the first support cylinder associated therewith (26), a first gap is present, which is greater than the gap between the second support piston (27.2) and the associated second support cylinder (26). 12. Piston engine according to one of the preceding claims, characterized in that the support piston (27, 27.1, 27.2) on its outer peripheral surface and / or the support cylinder (26) on its inner peripheral surface has a coating, preferably an inlet coating , by means of which the support piston (27, 27.1, 27.2) first under pressure in the support cylinder (26) has to be stuffed into and wears down during operation, thereby a gap between the support piston (27, 27.1, 27.2) and the support cylinder create, and / or a protective coating, which has a higher abrasion resistance than the actual material of the support piston (27, 27.1, 27.2) and / or the support cylinder component (10). 13. Piston engine according to one of claims 1 to 12, characterized in that the support cylinder component (10) has substantially the shape of a sleeve and / or a tube, if in the support cylinder component (10) has a single support cylinder (26). is trained. 14. Piston engine according to one of claims 1 to 13, characterized in that the cross-sectional area of the or each support cylinder (26) has round, circular, oval, substantially polygonal or another geometric shape. 15. Piston engine according to one of claims 1 to 14, characterized in that the outer contour of the support cylinder component (10) is arbitrary, in particular cylindrical. 16. Piston engine according to one of claims 1 to 15, characterized in that the adjusting mechanism (20) has two support pistons (27, 27.1, 27.2) which are each arranged in a different support cylinder (26) that a first sleeve (26.1) and a second sleeve (26.2) are inserted into the connecting rod shaft (17.1) and each form a support cylinder (26) and that the first sleeve (26.1) has a different inner diameter than the second sleeve (26.2) and / or has a different outer diameter than the second sleeve (26.2). 17. Piston engine according to one of the preceding claims, characterized in that between a support cylinder (26) and the support piston associated therewith (27, 27.1, 27.2), a targeted leakage path is formed. 18. Piston engine according to claim 17, characterized in that the support piston (27, 27.1, 27.2) is provided without a separate sealing element between the support piston (27, 27.1, 27.2) and support cylinder and without sealing element in the support cylinder (26) is arranged. 19. Piston engine according to claim 17, characterized in that the support piston (27, 27.1, 27.2) is provided with a sealing element, which allows a targeted leakage, preferably by means of a division in a joint region of the sealing element and an axial clearance between a height of the sealing element on the one hand and on the other hand, a groove height of a groove in which the sealing element is arranged.