AT519140A1 - Length adjustable connecting rod with mechanical adjustment - Google Patents

Abstract

The invention relates to a connecting rod (100) for a reciprocating piston engine, in particular for a reciprocating internal combustion engine, comprising: - a length adjustment device (6) for adjusting an effective connecting rod length (L) of the connecting rod (100), - a hydraulically actuatable control device which can be switched between at least two switching positions (15) for controlling the length adjustment device (6), - an actuation device (25) mechanically switchable from outside the connecting rod (100) between a first and a second actuation position for switching the control device (15), wherein the actuation device (25) is connected to the control device (15) via at least one hydraulic actuating line (27, 28) is operatively connected. According to the invention, the actuating device (25) has at least one first actuating element (29) and a second actuating element (30). Depending on the actuation position of the actuation device (25), one of the two actuation elements (29, 30) projects farther from one surface of the connecting rod (100) than the other of the two actuation elements (29, 30).

Description

Length adjustable connecting rod with mechanical adjustment

The present invention relates to a length-adjustable connecting rod for a reciprocating engine, in particular for a reciprocating internal combustion engine, comprising a length adjustment device for adjusting an effective connecting rod length of the connecting rod, a hydraulically actuated and switchable between at least two switching positions control device for controlling the length adjustment device and a mechanically from outside the connecting rod between a first and a second actuating position switchable actuator for switching the control device, wherein the actuating device is operatively connected to the control device via at least one hydraulic actuating line.

Furthermore, the present invention relates to a reciprocating engine with at least one such connecting rod and a vehicle with an internal combustion engine of the aforementioned type.

The connecting rod of a reciprocating engine generally connects a crankshaft to a piston, wherein the connecting rod converts the linear motion of the power piston into the circular motion of the crankshaft (linearly oscillating axial motion) or conversely, a circular motion into a linear motion.

At a smaller connecting rod eye, the piston is preferably fastened with a piston pin and a connecting rod bearing is provided on a larger connecting rod eye, by means of which the connecting rod is fastened to the rotating crankshaft. Between the smaller connecting rod eye, which is located at a connecting rod, and the larger connecting rod eye, which is located on a connecting rod, while the conrod shaft is generally arranged.

Adjustable connecting rods are used in particular in reciprocating engines with variable compression ratio for adjusting the compression ratio. By adjusting the connecting rod length, the compression ratio can be changed because the top dead center of the piston movement is moved. Length-adjustable connecting rods are known in principle from the prior art, for example from WO 2015/055582 A2, AT 512 334 A1 or DE 10 2012 020 999 A1.

In particular, PCT / EP2016 / 064194 of the applicant relates to a length-adjustable connecting rod or a length-adjustable connecting rod for a reciprocating engine, with at least a first rod part and a second rod part, wherein the two rod parts by means of a length adjustment in the direction of a longitudinal axis of the connecting rod in particular telescopically and / or can be displaced into one another, wherein the length adjusting device can be charged with a hydraulic medium via at least one hydraulic channel and wherein the at least one hydraulic channel can be fluidly connected to at least one hydraulic medium supply channel by a control device.

Basically, with adjustable-length connecting rods, the task of how to actuate or control the length adjustment of the connecting rod from an actuating system of the reciprocating engine to the linearly oscillating moving connecting rod can be transferred.

The prior art has various approaches for mechanical transmission:

Document WO 2014/019684 A1 relates to a variable compression reciprocating internal combustion engine having a variable compression compressor of the reciprocating internal combustion engine, wherein the variable compression actuator is a variable length variable end piston engine having a variable length piston Compression height and / or a crankshaft with a variable crankshaft radius of the reciprocating internal combustion engine actuated and the actuating unit is arranged in a lower region of the reciprocating internal combustion engine, where it is mechanically switched, for example via a movable link unit.

The document DE 10 2005 055 199 A1 relates to a

Hubkolbenverbrennungskraftmaschine with at least one adjustable variable compression ratio in a reciprocating piston by means of an adjusting mechanism which comprises at least one arranged in a connecting rod eye or a Hublagerauge a connecting rod eccentric for changing an effective length of the connecting rod, a displacement of the eccentric, along which the eccentric means of a by a Movement of the connecting rod caused acting

Torque is movable and at least one variable resistor, which acts on an adjusting movement of the eccentric and causes at least a damped adjusting movement of the eccentric.

The document DE 197 03 948 C1 relates to a device for changing the compression of a reciprocating internal combustion engine with a crank shaft fixed in the motor housing, a connecting rod mounted on a crank of the crankshaft, a piston mounted on the connecting rod, fixed inside a motor housing and movable downward piston, and an eccentric sleeve, which is mounted with its cylindrical inner surface on the crank and with respect to the inner surface eccentric cylindrical outer surface on the connecting rod, so that by rotation of the sleeve relative to the connecting rod, the effective length of the connecting rod is changeable. At the connecting rod a locking member is mounted, which locks the sleeve in a first locking position when moving in one direction and locks the sleeve in a second locking position when moving in another direction, wherein the one locked rotational position of the sleeve about maximum and the other locked rotational position about corresponds to a minimum effective connecting rod length. The movement of the locking member is controlled by a arranged in the crankcase, mechanically actuated slide track.

A disadvantage of the solutions mentioned are on the one hand the complex devices for length adjustment, on the other hand, the error-prone mechanical actuation of the connecting rod, which means a high Justageaufwand in particular during assembly of the reciprocating engine.

It is therefore an object of the invention to provide an improved connecting rod for a reciprocating engine, the effective or effective connecting rod length can be easily adjusted mechanically. In particular, it is an object of the invention to provide an improved actuating mechanism for adjusting the effective connecting rod length. It is a further object of the invention to provide a correspondingly improved reciprocating engine or vehicle with such reciprocating engine.

This object is achieved by a connecting rod, a reciprocating piston engine with such a connecting rod and a vehicle according to the independent claims. advantageous

Embodiments of the invention are claimed in the dependent claims. The teaching of the claims is hereby made part of the description.

A first aspect of the invention relates to a connecting rod mentioned above, wherein the actuating device has at least one first actuating element and a second actuating element and depending on the operating position of the actuating device of one of the two actuating elements further protrudes from a surface of the connecting rod than the other of the two actuating elements.

A second aspect of the invention relates to a reciprocating engine with at least one length-adjustable connecting rod according to the first aspect of the invention.

A third aspect of the invention relates to a vehicle with a reciprocating engine, in particular with a reciprocating internal combustion engine, which is formed according to the second aspect of the invention.

A connecting rod in the sense of the invention is a connecting element which is conventionally provided in reciprocating engines and has an elongated design and which is arranged between piston and crankshaft and via which the piston is mechanically connected to the crankshaft.

A reciprocating piston engine according to the invention is a machine with which a linear lifting movement of a piston can be converted into a rotational movement of a shaft or, conversely, a rotational movement of a shaft into a linear lifting movement of a piston.

The invention is based in particular on the recognition that an actuation of a length-adjustable connecting rod should preferably take place mechanically, since thereby a fail-safe, reproducible actuation is ensured which, on the one hand, withstands the high forces occurring during the movement of a connecting rod and, on the other hand, the relatively high temperatures, which for example occur in a combustion engine as a reciprocating engine. The invention is based in particular on the approach to control the control of the control device via two, in particular redundant, actuators.

This is particularly advantageous since in this way the mechanical transmission of the control command to the connecting rod, which is made more difficult by the high rotational speeds of the crankshaft and the ambient conditions in the engine block, can be improved.

The connecting rod according to the invention is preferably designed such that not only the effective or effective connecting rod length is adjustable, that is, the distance between a rotation axis in the small connecting rod and a rotation axis in the large connecting rod, but also the absolute length of the connecting rod. About the mechanical actuation of the actuators from outside the connecting rod, in particular by an actuator of the reciprocating engine, thus a switching of the control device is effected. This switching of the control device is in turn used to control the length adjustment device accordingly to adjust the effective connecting rod length accordingly.

Embodiments of the invention will now be described. The features of the individual embodiments can be combined with each other, unless this is expressly excluded.

In a variant of the invention, the first actuating element and the second actuating element protrude from the surface of a bearing cap of the connecting rod. This is particularly advantageous since, in this way, depending on the switching state, the operating element to be actuated to change the switching state is exposed. As a result, a mechanical actuation from outside the connecting rod, for example by an actuator device in the region of the crankcase, is possible. In addition, in this way, a mechanical actuation of the actuators in a movement phase of the connecting rod can take place when the axial velocity component, i. a velocity component in an at least substantially vertical direction, low, in particular at least substantially substantially zero, is.

In this case, the first actuating element and the second actuating element are each mounted displaceably in the axial direction, wherein preferably the axial direction of the first and the second actuating element is parallel to a longitudinal center plane of the connecting rod and / or parallel to a Pleuellängsachse. In this case, the first axial direction of the first actuating element and the second axial direction of the second actuating element extend parallel to a longitudinal center plane of the connecting rod and / or parallel to a connecting rod longitudinal axis. A longitudinal median plane of the connecting rod is understood to mean a plane which contains the longitudinal axis of the spinal rod and is normal to a - if used in accordance with its intended purpose -

Crankshaft axis extends. Conveniently, the actuators are individually stored in the connecting rod. Their axial direction is advantageously parallel, ie the first axial direction and the second axial direction are parallel. As a result, a simple operation is possible and the extension of the connecting rod in a direction along the crankshaft axis is minimized. Also, an actuator of the actuators can be designed to save space, that it is not the crankshaft or its weight elements in the way when used properly the connecting rod.

In a variant of the invention, the first actuating element is movably or movably mounted in a first actuating element recess arranged in the connecting rod between a first and a second end position, and the second actuating element is arranged in a second one arranged in the connecting rod

Betätigungselementausnehmung movably or movably mounted between a first and a second end position, wherein preferably the actuating elements in the first end position protrude farther from a surface of the connecting rod than in the second end position.

This is particularly advantageous since in this way the already existing movement of the connecting rod in the axial direction can be used to move the two actuating elements in the direction of at least one, in particular stationary, arranged inside the engine block actuator element which acts on at least one of the two actuating elements , This is particularly advantageous because it avoids in this way that two components (actuating element and actuator) that move rapidly in a three-dimensional space must meet at a certain point in time at a certain position. In the present case, the actuator can be positioned in an advantageous manner and then it can be waited until the connecting rod passes on its trajectory the next time the actuator.

Preferably, the actuating elements protrude in the installed position down in the manner of the connecting rod or the bearing cap, so that during the lifting movement during a power stroke, the connecting rod can be passed to a fixedly arranged in the crankcase actuator element, such that by means of the actuator mechanically an axial Displacement of at least one of the actuators is effected, preferably from a first

End position in a second end position or vice versa. Preferably, the axial displacement of at least one of the actuating elements can also be divided over a plurality of strokes of the connecting rod.

In a variant of the invention, in the first actuation position of the actuation device, the first actuation element is in a first end position and the second actuation element in a second end position and in the second actuation position of the actuation device the first actuation element in a second end position and the second actuation element in a first end position ,

In a further variant of the invention, the first actuation recess and the second actuation recess are flow-connected to one another via a connection channel or flow-connected, wherein preferably the connection channel is flow-connected to a first hydraulic medium supply line. As a result, hydraulic medium can be supplied to the actuating device, for example, from the connecting rod bearing of the large connecting rod via grooves formed there, which are connected via the crankshaft and corresponding recesses to the oil or lubrication system of the reciprocating piston engine. In this case engine oil is used as the hydraulic medium, but other media can also be used. Conveniently, the first actuating recess and the second actuating recess via a respective hydraulic actuating line to the control device flow-connected or flow-connected. In this case, advantageously, the control device via the first and / or the second actuating element with at least a first hydraulic medium supply line is connected. In a variant of the invention, the control device via the first and / or the second actuating element with at least one drainage channel is flow-connected. It is thereby possible to supply the control device with hydraulic medium via the actuating device or to drain the hydraulic medium from the control device, in particular into the crank space surrounding the connecting rod when used as intended.

Advantageously, the first actuating element has a first drainage channel and / or the second actuating element has a second drainage channel, wherein the first / second drainage channel is preferably designed to derive hydraulic medium from a first / second actuating line into a crank chamber surrounding the connecting rod when used as intended , By forming the drainage channels in the actuators a simplified and faster production is possible because fewer holes must be performed in the connecting rod for the function of the invention.

According to a variant of the invention, in a first end position of the first / second actuating element, a fluid connection between a first hydraulic medium supply line and the control device, in particular between the first hydraulic medium supply line and a first / second actuation line assigned to the first / second actuation element, is released and in a second end position of the first the first / second actuating element is a fluid connection between a first hydraulic medium supply line and the control device, in particular between the first hydraulic medium supply line and a first / second actuating element associated with the first / second actuating line blocked.

In a further variant, in a first end position of the first / second actuating element, a fluid connection between the control device and at least one drainage channel, in particular between a first / second actuating line assigned to the first / second actuating element and a first / second drainage channel, is blocked and in a second end position of the second first / second actuating element, a fluid connection between the control device and at least one drainage channel, in particular between a first / second actuating element associated first / second actuating line and a first / second drainage channel, released.

This makes it possible to achieve a filling and draining of the control device with hydraulic medium in a simple manner by mechanical adjustment of the actuators. For a further simplification of the function, the first actuating element and the second actuating element are operatively connected to one another via a coupling element, wherein preferably the coupling element is disposed within the connecting rod, particularly preferably within a bearing cap of the connecting rod. It is advantageous if by means of the coupling element on the movement of one of the actuating elements in a first end position, the other of the actuating elements can be brought into a different from a first end position second end position, and vice versa.

This makes it possible to change by actuating only one actuating element and the other actuator in its position and thus act on the switching position of the control device. This increases the transmission reliability of the mechanical actuation and thus makes a contribution to the smooth, low-emission and functionally reliable operation of the reciprocating engine. The coupling element can be embodied, for example, as a coupling element pivotably mounted in the connecting rod or else outside the connecting rod, in particular as a rocker switch, which is connected in each case movably to the actuating elements. Conveniently, the control device has an actuating piston, which is arranged axially displaceably between a first switching position and a second switching position in a control chamber, wherein the control chamber with at least one actuating line is flow-connected or flow-connected. In a further variant, the control chamber of the control device is designed as a double-acting control chamber, wherein the control chamber of the control device via a first actuating line and a second actuating line with the actuating device operatively connected or operatively connected, wherein the control piston the control chamber into a first control pressure chamber and a second The control pressure chamber divides, wherein the first control pressure chamber with the first actuating line is flow-connected or flow-connected and the second control pressure chamber with the second actuating line is fluidly connected or flow-connected.

In this advantageous embodiment can be dispensed with a return spring for the actuating piston, since the actuating piston is moved or moved by a pressure difference in the first control pressure space between the first control pressure chamber and the second control pressure chamber in the control device, that is between the first shift position and the second shift position is axially displaced. In this way, it is possible to dispense in particular with a change in the pressure of the hydraulic medium. The pressure of the hydraulic medium can always remain constant and is either in the one, the first control pressure chamber or in the second control pressure chamber. This is particularly advantageous if the hydraulic medium is also used for lubrication of the connecting rod bearing.

The adjusting piston is preferably displaceable in this embodiment in the longitudinal center plane of the connecting rod. If the control device is designed as in PCT / EP2016 / 064193, then lift valves are preferably arranged such that lift axes of the valve bodies are aligned parallel to the crankshaft axis. As a result, these are decoupled from vertical and centrifugal acceleration, which occur in the connecting rod. As a result, relatively low spring return forces for the valve body are sufficient to keep the globe valves closed. This leads to a good response of the control device. Further preferably, the control chamber is designed as a control cylinder.

In principle, the actuating piston can be oriented arbitrarily and some of the possible orientations are shown in PCT / EP2016 / 064193.

In a further advantageous embodiment of the connecting rod, the control device and the actuating device are arranged on opposite sides of the large connecting rod eye. As a result, the available space in the connecting rod is used particularly effectively. Furthermore, an increase in weight on one side of the connecting rod is compensated by additional elements of the control device on the other side of the connecting rod by additional elements of the actuator, so that an imbalance of the connecting rod can be reduced.

In a further advantageous embodiment of the connecting rod, the control device in the connecting rod shaft, in particular in a first connecting rod shaft portion, preferably closer to the larger connecting rod than the smaller connecting rod, arranged.

The length adjustment device can be designed in various ways. Preferably, however, the length adjustment device is designed in such a way that one of the two connecting rod shaft sections is formed as a guide body in a connecting rod shaft section consisting of two connecting rod shaft sections and the other shaft section has a piston element displaceable in the guide body, in particular between a first end side of the piston element and the guide body a first working space and between the second end face of the piston member and the guide body, a second working space is spanned, wherein in the first working space, a first hydraulic channel opens and opens into the second working space, a second hydraulic channel, which come from the control device. With such a connecting rod shaft can be realized in a particularly simple manner, a length-adjustable connecting rod, in particular a hydraulically length-adjustable connecting rod. The two connecting rod shaft sections in this case form in particular the hydraulic cylinder.

For length-adjustable position of such a connecting rod according to the invention, the control device, a preferably pressurized hydraulic medium can be supplied, in particular via a hydraulic medium supply line. One of the two hydraulic channels, which are each connected to one of the two working chambers, can be fluidly connected to the hydraulic medium supply channel via the control device.

In a further advantageous embodiment, the control device has a, in particular hydraulically actuated, actuating piston. Conveniently, the length adjustment device thus has at least one hydraulic cylinder or cylinder space, at least one piston and a first hydraulic working space and a second hydraulic working space, wherein in a first switching state of the control device, a hydraulic fluid return from the second working space is blocked and the first working space is drained and in a second switching state of the second working space is drained and a hydraulic fluid return is blocked from the first working space.

A hydraulic fluid return within the meaning of the invention is a reduction of a hydraulic medium, in particular oil, in a working space.

Drainage in the sense of the invention means that a hydraulic medium return, that is a reduction of the hydraulic medium in a working space, is made possible. The draining takes place in particular by forces or pressures which act on the connecting rod from outside the connecting rod, for example by the ignition process in an internal combustion engine, or which are initiated by a movement of the piston due to the crankshaft movement, for example centrifugal forces at top dead center.

In a variant of the invention, the connecting rod has a second hydraulic medium supply line which can be connected to the first working chamber and the second working chamber, wherein the connecting rod, in particular the control device, is designed such that in a first switching state of the control device the first working chamber via the second Hydraulic medium supply line with hydraulic medium can be filled and in a second switching state of the control device, the second working space.

In a further advantageous embodiment of the connecting rod, the first working space and the second working space are in each case flow-connected via a check valve, in particular permanently, to the second hydraulic medium supply line. In this embodiment, the work spaces can in principle be constantly filled with the hydraulic medium, wherein the connecting rod length is controlled by the drainage.

The first and second hydraulic medium supply lines are in this case preferably flow-connected to a connecting rod bearing seat on a crankshaft, so that the hydraulic medium used there for lubrication flows into the hydraulic medium supply lines. The working spaces here are in particular high-pressure chambers, which can be closed in the context of technical tolerances hydraulic medium tight, even at high pressures of more than 1200 bar.

Depending on which of the two working spaces the higher pressure is applied, e.g. by filling with hydraulic medium, or which is drained of the two working spaces, the two shaft portions of the connecting rod are telescopically apart or pushed together by the movement of the crankshaft and external forces, so that the effective or effective connecting rod length increases or decreases.

The foregoing features and advantages with respect to the first aspect of the invention apply equally to the second and third aspects of the invention.

Accordingly, the object of the invention is also achieved by a reciprocating engine, in particular reciprocating internal combustion engine, with at least one connecting rod described above. In this case, the actuating device can be switched between the first and the second actuating position by means of an actuator device arranged fixedly in the crankshaft housing. Conveniently, an actuator device is provided for each inventive connecting rod.

The actuator device, in particular in the crankshaft housing, preferably has a slotted guide, in particular an adjustable slotted guide, a camshaft, in particular a camshaft with rams, at least one fluid spray nozzle, a gas nozzle, a magnet, in particular an electromagnet, floating in oil basins and / or molds, in particular, waveforms which extend at least substantially parallel to the crankshaft axis, on.

In a variant of the invention, the actuator device has a first actuator element and a second actuator element, wherein the first actuating element can be actuated with the first actuator element and the second actuating element can be actuated with the second actuator element.

An actuator element has, in a variant of the invention, a cam which is rotatable about a rotation axis extending preferably parallel to the crankshaft. In this case, the actuating element can be actuated directly with the cam or via an intermediate element arranged between the cam and the actuating element, which is preferably designed as a cup tappet.

In a further variant of the invention, the actuator element is designed as a switching ramp movable in a direction normal to the crankshaft axis, wherein preferably the switching ramp along its longitudinal extent in the direction of the connecting rod has continuously decreasing thickness, particularly preferably the furthest from the crankshaft axis range on thickest executed. Conveniently, two actuator elements designed as switching ramps are provided. As a result, by moving a first shift ramp in the direction of the crankshaft axis, the thicker region of the shift ramp can interact with the first actuation element and thus move it into its end position. By simultaneously moving a second switching ramp in the opposite direction, the second actuator can go to the complementary end position.

Advantageously, at least one end of the first and / or second actuating element-in particular the end pointing away from the small connecting-rod eye-is designed as a control surface. Preferably, this may be as

Wedge surface be shaped. In this way, a simple displacement with the stationary actuator device can be realized, wherein the displacement is effected by sliding of the actuator on the wedge surface. For this purpose, it is advantageous if wedge angle, contact pressure, etc. are matched to one another.

These and other features and advantages will become apparent from the claims and from the description also from the drawings, wherein the individual features may be implemented alone or in each case in the form of sub-combinations in an embodiment of the invention and an advantageous as well as for can represent protectable design for which protection is also claimed, if it is technically feasible.

The invention will be explained in more detail below with reference to non-limiting exemplary embodiments, which are illustrated in the figures. In it show at least partially schematically:

Fig. 1 is a perspective oblique view of a connecting rod according to the invention;

Fig. 2 is a plan view of the connecting rod of Fig. 1;

Fig. 3 is a partial perspective sectional view of the connecting rod of Figure 1 along the line E-E in Fig. 2.

Fig. 4 is a view of the detail Z of Fig. 3;

5 shows a partially transparent view of the bearing cover area of the connecting rod according to the invention;

6 shows a front view of a connecting rod according to the invention with a first variant of an actuator device;

Fig. 7 is a partial sectional view taken along the line C-C in Fig. 6;

Fig. 8 is a partial sectional view taken along the line D-D in Fig. 6;

9 is a front view of a connecting rod according to the invention with a second

Variant of an actuator device;

10 is a partial side view of the second variant of

Actuator device according to line V-V in Fig. 9;

11 shows a front view of a connecting rod according to the invention with a third variant of an actuator device;

FIG. 12 shows a view of the arrangement of FIG. 11 from below along line B-B in FIG. 11; FIG.

13 shows a hydraulic circuit diagram of an embodiment of a connecting rod according to the invention in a first actuation position; and

14 is a hydraulic circuit diagram of the connecting rod according to the invention of the embodiment of FIG. 13 in a second operating position.

Fig. 1 shows a perspective view of a connecting rod 100 according to the invention. The connecting rod 100 has a small connecting rod 1 for connecting the connecting rod 100 with a piston of the reciprocating engine and a large connecting rod 2 for connecting the connecting rod 100 with the crank pin of a crankshaft of the reciprocating engine, wherein the large connecting rod 2 has a removable connecting rod bearing cap 26 which is screwed via connecting rod 5 with the connecting rod shank.

The small connecting rod eye 1 is part of an upper, first Pleuelschaftabschnitts 3 and the large eye 2 is part of a lower, second Pleuelschaftabschnitts 4. The first Pleuelschaftabschnitt 3 is opposite the second Pleuelschaftabschnitt 4 between an extended position and an inserted position by an adjustment range (AL) in the direction of a longitudinal axis 100a of the connecting rod 100 adjustable, wherein the first Pleuelschaftabschnitt 3 and the second Pleuelschaftabschnitt 4 in particular telescopically into one another and are pushed apart, so that an effective connecting rod length L is adjustable. The effective connecting rod length L is defined by a distance of a rotation axis in the small connecting rod eye 1 to a rotation axis in the larger connecting rod eye 2.

The change in the effective connecting rod length L is effected by means of a length adjustment device 6, as can be seen by way of example and schematically in FIGS. 13 and 14.

The upper first connecting rod shaft portion 3 forms a piston 8 of a double-acting hydraulic cylinder and the lower second connecting rod shaft portion 4 the cylinder chamber 7, wherein a bottom 8a of the piston 8, i. a large connecting rod eye 2 facing side, a first effective surface of the piston 8 and an upwardly oriented top 8b in the form of an annular surface together with the upper first connecting rod shaft portion 3, a second effective surface.

The first operative surface of the upper first connecting rod shaft portion 3 forms with the lower part of the guide cylinder of the lower second Pleuelschaftabschnitts 4 a first hydraulic working space 9 and the second active surface of the upper first Pleuelschaftabschnitts 3 together with the upper part of the guide cylinder or cylinder chamber 7 of the lower second Pleuelschaftabschnitts 4 and a used at the upper end in the guide cylinder of the lower second Pleuelschaftabschnitts 4, unspecified here stop element a second hydraulic working space 10th

The active surfaces on the upper connecting rod shaft section 3 form pressure application surfaces for a hydraulic medium conducted into the working chambers 9 and 10, in which case the engine oil used for lubrication of the reciprocating internal combustion engine is used as hydraulic medium. A first hydraulic channel 11 opens into the first working space 9 and a second hydraulic channel 12 opens into the second working space 10.

If the lower, first working space 9 is filled with hydraulic medium and a return from the first working space 9 is blocked and the upper, second working space 10 is drained, the connecting rod shaft portions 3 and 4 are pushed apart and the effective connecting rod length L increases. If, in contrast, the lower, first working space 9 is drained and the upper, second working space 10 is filled with hydraulic medium and a return from the second working space 10 is blocked, the connecting rod shaft sections 3 and 4 are pushed into one another and the effective connecting rod length L decreases. In direct connection with the connecting rod length L, the compression ratio of the corresponding cylinder also changes.

The oil supply of the first and second hydraulic channels 11,12 via a second hydraulic medium supply line 13, which is connected via a Ölversorgungsnut 14 with the connecting rod bearing of the large connecting rod 2 fluidkommunzierend.

To control the filling of the working spaces 9, 10 with hydraulic medium and for draining the working spaces 9, 10 and thus for controlling the adjustment of the effective connecting rod length L, the connecting rod 100 has a control device 15, wherein the control device 15 in this embodiment of a connecting rod 100 according to the invention lower, second connecting rod shaft portion 4 is arranged. The control device 15 is designed in principle like a control device described in PCT / EP2016 / 064193, which is referred to for further, not described here details of the control device 15. In principle, the invention can also be implemented with differently designed control devices.

The control device 15 has a first lift valve 16 arranged in the flow path between the second hydraulic medium feed line 13 and the first hydraulic passage 11 or the first work space 9 and having a first valve space in which a first valve body pretensioned by a first valve spring is pressed against a first valve seat , wherein in the first valve chamber, the first hydraulic channel 11 opens.

Furthermore, the control device 15 has a second lift valve 17 arranged in the flow path between the second hydraulic medium supply line 13 and the second hydraulic passage 12 or the second work space 10, with a second valve space in which a second valve body biased by a second valve spring is pressed against a second valve seat is, wherein the second hydraulic passage 12 opens into the second valve chamber. The first and second valve body of the two globe valves 16, 17 are formed in the illustrated embodiment by balls, but can also be designed differently.

Furthermore, in this inventive connecting rod 100, the control device 15 has a in the longitudinal center plane α of the connecting rod 100 and normal to the longitudinal axis 100a of the connecting rod 100 between a first, shown in FIG. 13 switching position and a second, shown in Fig. 14 switching position in a two-sided acting Control chamber 18 axially displaceable actuating piston 19, which has extending in the axial direction, rod-like ends and which extends between the first lift valve 16 and the second lift valve 17. The longitudinal center plane α is shown in FIG. 8, but coincides, for example, in FIG. 6 with the plane of the page.

The actuating piston 19 is designed such that in the first switching position according to FIG. 14, its end facing the first lift valve 16 lifts off the valve body of the first lift valve 16 from the valve seat and thus the flow path between the first working chamber 9 via the first hydraulic channel 11 to the second hydraulic medium supply line 13 releases, so that the first working space 9 is drained, while the second valve body of the second lift valve 17 facing the end of the actuating piston 19 is spaced from the valve body of the second lift valve 17, so that the valve body rests against the valve seat and a return from the second working space 10 in the second hydraulic medium supply line 13 is locked.

Thus acts during the lifting movement of the connecting rod 100, i. During a power stroke, a mass force on the connecting rod 100, which pulls the second upper Pleuelschaftabschnitt 3 up, hydraulic fluid is sucked through the actually closed second lift valve 17 by the first valve body by the suction force generated in the second working space 10 against the restoring force of the first Valve spring is raised.

As a result, the upper, second working chamber 10 fills with hydraulic medium via the second hydraulic channel 12, while hydraulic medium is forced out of the lower first working chamber 9 into the first hydraulic channel 11 and is discharged into the second hydraulic medium supply line 13 via the first lifting valve 16 opened by means of the control piston 19. The connecting rod 100 is thereby longer. It may take several strokes to reach the maximum effective connecting rod length.

Accordingly, the actuating piston 19 causes in a second switching position shown in FIG. 13 lifting the valve body of the second lift valve 17 from the valve seat, so that the second working space 10 is drained, while the valve body of the first lift valve 16 abuts the valve seat, so that a return from the first working space 9 is locked.

Thus acts during the lifting movement of the connecting rod 100, i. During a power stroke, a mass force on the connecting rod 100, which presses the second upper Pleuelschaftabschnitt 3 down, hydraulic fluid is sucked through the actually closed first lift valve 16 by the valve body raised by the suction force generated in the first working space 9 against the restoring force of the valve spring becomes. As a result, the lower, first working chamber 9 fills with hydraulic medium via the first hydraulic channel 11, while hydraulic medium is forced out of the upper second working chamber 10 into the second hydraulic channel 12 and is discharged into the second hydraulic medium supply line 13 via the second lifting valve 17 opened by means of the control piston 19. The connecting rod 100 is thereby shorter. It may well take several strokes to reach the minimum, effective end length. For a faster filling of the working chambers 9, 10, the control device 15 in this embodiment of the connecting rod 100 additionally via a bypass check valve 20, 21 directly to one of the working chambers 9, 10 and the second hydraulic medium supply line 13 connected bypass hydraulic lines 22, 23 wherein a bypass check valve 20 is disposed in the flow path between the second hydraulic medium supply line 13 and the first working space 9, and a bypass check valve 21 is located in the flow path between the second hydraulic medium supply line 13 and the second working space 10.

In order to avoid pressure waves in the hydraulic length adjustment system, which on the one hand can lead to an unwanted length adjustment and on the other hand can adversely affect the entire hydraulic circuit of the reciprocating internal combustion engine or even cause damage, additional throttles 24 are arranged in the flow path in some hydraulic channels.

For switching the control means 15 from the first switching state to the second switching state and vice versa, i. for moving the adjusting piston 19 from the first switching position to the second switching position and vice versa, the connecting rod 100 according to the invention a mechanical actuator 25, which in this connecting rod 100 according to the invention via a first hydraulic actuating line 27 and a second hydraulic actuating line 18 with the actuating piston 19 of Control device 15 is operatively connected.

For this purpose, the actuating piston 19 divides the control chamber 18, in which the adjusting piston 19 is arranged axially displaceable, in a first control pressure chamber 18a and a second control pressure chamber 18b, wherein in this inventive connecting rod 100, the first control pressure chamber 18a with the first Actuating line 27 is connected fluidkommunizierend and the second control pressure chamber 18 b with the second actuating line 28th

By generating a pressure difference on the actuating piston 19, in particular a pressure difference between the first control pressure chamber 18a and the second control pressure chamber 18b, the actuating piston 19 can be moved from the first switching position to the second switching position.

The actuating device 25 has for this purpose a first actuating element 29 and a second actuating element 30, wherein the first actuating element 29 in a connecting rod 100, or more precisely in the illustrated embodiment in the connecting rod bearing cover 26 arranged first Betätigungselementausnehmung 31 and the second actuating element 30 in a second Betätigungselementausnehmung 32 is arranged. The actuating recesses 31, 32 are fluidly connected to one another via a connecting channel 33, wherein the connecting channel 33 is further connected to a first hydraulic medium supply line 34.

The first hydraulic medium supply line 34 is fluidkommunzierend via an oil supply groove 14 with the connecting rod bearing of the large connecting rod 2, wherein in the first hydraulic medium supply line 34, a supply check valve 37 is provided to

To reduce pressure pulses from the oil system or to prevent a return of the hydraulic medium from the connecting rod 100 in the oil system.

The Betätigungselementausnehmungen 31, 32 are on the hydraulic

Actuator lines 27, 28 operatively connected to the control device 15. This makes it possible to pressurize the control pressure chambers 18a, 18b of the control device 15 with hydraulic medium from the first hydraulic medium supply line 34. For this purpose, hydraulic medium channels 35, 36 are provided in the actuating elements 30, wherein in the illustrated embodiment, the first hydraulic medium channel 35 of the first actuating element 29 is designed as a circumferential groove and the second hydraulic medium channel 36 of the second actuating element 30 is also designed as a circumferential groove - see, for example. Fig. 4 and Fig. 5, where in Fig. 3 with a dashed circle and "Z" marked area is shown in detail. The control device 15 is thus connected via the actuating elements 30, 31 with the first hydraulic medium supply line 34. The hydraulic medium channels 35, 36 may also be different, e.g. as bores.

In order to be able to depressurize the control device 15 in addition to being pressurized, the control device 15 can be connected via the actuating elements 29, 30 to drainage channels 38, 39, 40.

In the illustrated embodiment according to e.g. 4, the first actuation element 29 has a first drainage channel 38 which consists of a first drainage channel section 38a running in the axial direction and a second drainage channel section 38b extending in the radial direction adjoining it. The first drainage channel 38 opens at the intended use of the connecting rod 100 in a surrounding crankcase 200. In the same way a second drainage channel 39 is executed in the second actuator 30, which consists of a third, extending in the axial direction drainage channel section 39a and an adjoining fourth, in Radial direction extending drainage channel portion 39b and opens into the crank chamber 200.

In a variant shown only schematically in FIGS. 13 and 14, the drainage channels 38, 39 open into an overall drainage channel 40, in which a

Drainage check valve 41 is arranged to prevent suction of air into the connecting rod 100 and the oil system. In a real embodiment, the drainage channels 38, 39 could also be designed as annular grooves and the total drainage channel 40 is formed by a bore in the region of the bearing cap 26.

The respective fluid connections - ie between the control device 15 and the first hydraulic medium supply line 34 or to the drainage channels 38, 39 - can now be produced in the following way:

The actuating elements 29, 30 are arranged so that they protrude from a surface of the connecting rod 100 or from the surface of the connecting rod bearing cover 26. Depending on whether the actuating device 25 is in a first or a second actuating position, one of the actuating elements 29, 30 is further away from the surface of the connecting rod 100.

The actuators 29, 30 are slidably mounted in the Betätigungselementausnehmungen 31, 32 in the axial direction 31a, 32a between the first and second end positions. The first actuating element 29 is displaceable in a first axial direction 31a, the second actuating element 30 is displaceable in a second axial direction 32a. In the exemplary embodiment shown, the axial directions 31a, 32a are parallel to one another and substantially parallel to the connecting rod longitudinal axis 100a, wherein they can also be arranged in variants or additionally parallel to a longitudinal center plane α of the connecting rod.

In one of the end positions, a fluid connection between the first hydraulic medium supply line 34 and control device 15 is produced via the actuation elements 29, 30, in the other end position a fluid connection between control device 15 and drainage channel 38, 39.

In the exemplary embodiment shown, the first end position is defined by the fact that the control device 15 is fluid-connected to the first hydraulic medium supply line 34 via the actuating element 29, 30 located in this first end position or its hydraulic medium channel 35, 36. In the second end position, the control device 15 is drained and is therefore connected to the crank chamber 200 via the actuating element 29, 30 located in this second end position or its drainage channel 38, 39.

In the first end position, the actuating elements 29, 30 are further from the surface of the connecting rod 100 than in the second.

According to the invention, there is always an actuating element 29, 30 in the first end position and the respective other actuating element 29, 30 in the second end position. In this case, a first actuating position of the actuating device 25 is defined by the fact that the first actuating element 29 is in the first end position and the second actuating element 30 is in the second end position (see eg FIGS. 4, 5, 6, 8). Fig. 9, Fig. 13); in a second actuation position, the first actuator 29 is in the second end position and the second actuator 30 is in the first end position (see, e.g., Figures 3, 11, 14).

In order to secure or simplify the function of the actuating device 25, in the exemplary embodiment illustrated, the first actuating element 29 and the second actuating element 30 are operatively connected to one another via a coupling element 42. The coupling element 42 is designed as a pivotable about a coupling element axis 42a mounted in the connecting rod bearing cap 25 rocker switch. The coupling element axis 42a lies normal to the connecting rod longitudinal axis 100a. Conveniently, the masses of the actuating elements 29, 30 are the same, so that the masses moved around the coupling element axis 42a are the same. As a result, a compensation of the - in particular at high speeds increasing inertial forces due to the actuator 25 is achieved.

Active connection means in this case that by means of the coupling element 42 via the movement of an actuating element 29, 30 in a first end position, the other of the actuating elements 29,30 is simultaneously brought into the second end position different from the first end position, and vice versa. Thus, if the end position of an actuating element 29, 30 is actively changed, the coupling element 42 transmits the change also to the other actuating element 29, 30, without having to additionally set an action. The coupling element 42 has corresponding devices for operative connection with the actuating elements 29, 30 -for example, 4 and 5 recesses in the actuating elements 29, 30 are shown in Figs., In which the coupling element 42 engages.

In order to ensure additional functional reliability, in the embodiments according to FIG. 4 and FIG. 5 spring-loaded locking bolts 53 are provided which are mounted in the connecting rod bearing cover 26 or generally in the connecting rod 100 and cooperate with locking receptacles in the actuating elements 29, 30 - the locking bolts 53 engage in the respective end positions in the actuators 29, 30 and prevent them from moving from their positions.

In Fig. 5 it is shown that the actuating device 25 may also be designed as a separate component that is screwed from the bottom to the connecting rod bearing cap 26 and secured in some other way. See the screws 52. This significantly simplifies the production of the solution according to the invention.

The first actuating position will now be explained with reference to FIG. 13:

The first actuating element 29 is in the first end position. Therein, a fluid connection between the first hydraulic medium supply line 34 and the control chamber 18 of the control device 15, in particular the first control pressure chamber 18a, via the first actuating line 27 and the first hydraulic fluid passage 35 fluidly connected. The pressure from the oil system - engine oil is used here as a hydraulic medium - acts in the first control pressure chamber 18a on the actuating piston 19 and causes its movement to the left. This movement is assisted by the fact that the second actuating element 30 is in the second end position and the second control pressure chamber 18b is drained: between the control chamber 18, in particular the second control pressure chamber 18b, and the crank chamber 200, via the second actuating line 28th , the second drainage channel 39 in the second actuator 30 and the total drainage channel 40 made a fluid connection. Due to this pressure difference in the control chamber 18, the control device 15 is in the second switching position; the first working space 9 is drained, the second working space 10 is filled, the connecting rod 100 is shortened.

In the second operating position according to FIG. 14, the situation is exactly the opposite - as described above, the second working space 10 is drained, the first working space 9 fills up with hydraulic medium and the connecting rod 100 becomes long.

It should be noted that FIGS. 13 and 14 are schematic representations and that the arrangement of the total drainage channel 40 below the connecting rod 100 is made for reasons of clarity and does not mean that the total drainage channel 40 extends outside of the connecting rod 100. It should also be noted that by omitting the total drainage channel 40, an embodiment as shown in FIGS. 3, 4 and 5.

The change in the actuation position of the actuator 25 Change the end positions of the actuators 29, 30 - or only one actuator 29, 30, since the other actuator 29, 30 is moved over the coupling element 42 - can now easily implemented, low-error mechanical way to be implemented:

For this purpose, a stationary in the crankcase (not shown in the figures) arranged actuator 43, wherein in a reciprocating engine with a plurality of connecting rods 100 invention conveniently for each connecting rod 100 own actuator is provided - for reasons of clarity in the figures only ever a connecting rod each shown with an actuator device.

FIG. 3, FIG. 6, FIG. 7 and FIG. 8 show an exemplary embodiment of an actuator device 43 in the form of a camshaft, in which are cams on a rotation axis 44 extending parallel to a crankshaft axis 200a (indicated in FIGS. 6 and 8) 45, 46 are provided, which act as actuator elements and move the actuators 29, 30 in the axial direction. In FIG. 3, a first cam 45 has displaced the first actuating element 29 into the second end position, while via the coupling element 42 the second actuating element 30 is brought into the first end position. In FIG. 6 (or see also FIGS. 7 and 8), a second cam 46 has displaced the second actuating element 30 into the second end position, the first actuating element 29 is moved into the first end position. In this case, only one axis of rotation 44 is needed, which can be tuned with the Pleuelgeige that a wear-free and low-noise adjustment is possible.

Fig. 9 and Fig. 10 show a variant where two axes of rotation 44, 44 'are provided: Here, the actuator elements of cams 45, 46 and between cams 45, 46 and actuators 29, 30 arranged cup tappets 47, 48. The tappets 47 , 48 act as intermediate elements. The first actuating element 29 is thereby brought into the first end position by actuating the second actuating element 30 via second cams 46 and second cup tappets 48.

FIGS. 11 and 12 show a further variant in which the actuator elements are designed as switching ramps 49, 50 which can be moved, for example, via a toothed rack 51 in a direction of movement Y normal to a crankshaft axis 200a. The shift ramps 49, 50 have along their longitudinal extent a continuously decreasing in the direction of the connecting rod 100 and the crankshaft axis 200a thickness. The part farthest from the crankshaft axis 200a is the thickest. Thickness is here understood to mean the extension in a direction substantially parallel to the longitudinal axis of the connecting rod 100a.

Depending on which actuator 29, 30 is to be switched, the first 49 or the second switching ramp 50 can be moved counter to the direction of rotation of the connecting rod 100 in the direction of the crankshaft axis 200a and gets into the range of Pleuelgeige. The actuating element 29, 30 impinges on the less thick part of the ramp and the continuously increasing thickness leads to further rotation of the connecting rod 100 to a displacement of the actuating element 29, 30 from the first to the second end position.

Fig. 11 shows an embodiment where just the second actuator is in the first end position, but by further rotation of the connecting rod 100 is moved shortly in the second end position. By executing with ramps even more low-wear operation or adjustment of the connecting rod 100 according to the invention is possible.

1 small connecting rod eye 2 large connecting rod eye 3 second, upper Pleuelschaftabschnitt 4 first, lower Pleuelschaftabschnitt 5 connecting rod 6 length adjustment 7 cylinder chamber 8 piston 8a bottom (of the piston 8) 8b top (of the piston 8) 9 first hydraulic working space 10 second hydraulic working chamber 11 first hydraulic channel 12 second hydraulic channel 13 second hydraulic medium supply line 14 oil supply groove 15 control device 16 first lift valve 17 second lift valve 18 control chamber 18a first control pressure chamber 18b second control pressure chamber 19 control piston 20, 21 bypass check valve 22, 23 bypass hydraulic line 24 throttle 25 actuator 26 connecting rod bearing cover 27 first (hydraulic ) Actuation line 28 second (hydraulic) actuation line 29 first actuation element 30 second actuation element 31 first actuation element recess 32 second actuation element recess 31a first axial direction 32a second axia le direction 33 connection channel 34 first hydraulic medium supply line 35 first hydraulic medium channel 36 second hydraulic medium channel 37 supply line check valve 38 first drainage channel 38a first drainage channel section 38b second drainage channel section 39 second drainage channel 39a third drainage channel section 39b fourth drainage channel section 40 total drainage channel 41 drainage check valve 42 coupling element 42a coupling element axis 43 actuator device 44, 44 'rotation axis 45, 46 Cam 47, 48 Cup tappets 49, 50 Tactile ramp 51 Rack 52 Screw 53 Locking pin 100 Connecting rod 100a Connecting rod axis 200 Crank space 200a Crankshaft axis α Longitudinal plane (of connecting rod 100) Y Movement direction of shift ramps

Claims (25)

claims 1. connecting rod (100) for a reciprocating engine, in particular for a reciprocating internal combustion engine, comprising: - a length adjustment device (6) for adjusting an effective connecting rod length (L) of the connecting rod (100), - a hydraulically actuated and switchable between at least two switching positions control device (15 ) for controlling the length adjustment device (6), an actuating device (25) mechanically switchable from outside the connecting rod (100) between a first and a second actuating position for switching the control device (15), wherein the actuating device (25) is connected to the control device (15 ) is operatively connected via at least one hydraulic actuating line (27, 28), wherein the actuating device (25) has at least one first actuating element (29) and a second actuating element (30) and, depending on the actuating position of the actuating device (25), one of the two actuating elements (29 , 30) far it protrudes from one surface of the connecting rod (100) than the other of the two actuating elements (29, 30). Second connecting rod (100) according to claim 1, characterized in that the first actuating element (29) and the second actuating element (30) from the surface of a bearing cap (26) of the connecting rod (100) protrude. 3. connecting rod (100) according to claim 1 or 2, characterized in that the first actuating element (29) and the second actuating element (30) each in the axial direction (31 a, 32 a) are displaceably mounted, wherein preferably the axial direction (31 a, 32a) of the first (29) and second actuating element (30) runs parallel to a longitudinal center plane (a) of the connecting rod (100) and / or parallel to a connecting rod longitudinal axis (100a). 4. connecting rod (100) according to one of claims 1 to 3, characterized in that the first actuating element (29) in a connecting rod (100) arranged first Betätigungselementausnehmung (31) between a first and a second end position is movable and the second actuating element (30) in a connecting rod (100) arranged second Betätigungselementausnehmung (32) between a first and a second end position is movable, wherein preferably the actuating elements (29, 30) in the first end position further from a surface of the connecting rod (100) protrude in the second end position. 5. connecting rod (100) according to one of claims 1 to 4, characterized in that in the first actuating position of the actuating device (25), the first actuating element (29) is in a first end position and the second actuating element (30) in a second end position and in that in the second actuation position of the actuation device (25) the first actuation element (29) is in a second end position and the second actuation element (30) is in a first end position. 6. Connecting rod (100) according to claim 4 or 5, characterized in that the first actuating recess (31) and the second actuating recess (32) are flow-connected to one another via a connecting channel (33) or flow-connected, wherein preferably the connecting channel (33) with a first hydraulic medium supply line (34) is fluidly connected. 7. connecting rod (100) according to one of claims 4 to 6, characterized in that the first actuating recess (31) and the second actuating recess (32) via a respective hydraulic actuating line (27, 28) with the control device (15) fluidly connected or flow-connected are. 8. connecting rod (100) according to one of claims 1 to 7, characterized in that the control device (15) via the first (29) and / or the second actuating element (30) with at least one first hydraulic medium supply line (34) is flow connected. 9. connecting rod (100) according to one of claims 1 to 8, characterized in that the control device (15) via the first (29) and / or the second actuating element (30) with at least one drainage channel (38, 39, 40) fluidly connected is. 10. connecting rod (100) according to one of claims 1 to 9, characterized in that the first actuating element (29) has a first drainage channel (38, 38 a, 38 b) and / or that the second actuating element (30) has a second drainage channel (39 , 39a, 39b), wherein the first / second drainage channel (38, 38a, 38b, 39, 39a, 39b) is preferably adapted to hydraulic medium from a first (27) / second actuating line (28) in a connecting rod (100 ) to dissipate crankcase (200) when used as intended. 11. connecting rod (100) according to one of claims 1 to 10, characterized in that in a first end position of the first (29) / second actuating element (30), a fluid connection between a first hydraulic medium supply line (34) and the control device (15), in particular between the first hydraulic medium supply line (34) and a first (27) / second actuation line (28) associated with the first (29) / second actuation element (30) is released and in a second end position of the first (29) / second actuation element (30) a fluid connection between a first hydraulic medium supply line (34) and the control device (15), in particular between the first hydraulic medium supply line (34) and the first (27) / second actuating element (30) associated first (27) / second operating line (28) blocked is. 12. connecting rod (100) according to one of claims 1 to 11, characterized in that in a first end position of the first (29) / second actuating element (30) has a fluid connection between the control device (15) and at least one drainage channel (38, 38a, 38b, 39, 39a, 39b, 40), in particular between a first (27) / second actuating element (30) associated with the first (27) / second actuating line (28) and a first (39) / second drainage channel (40) blocked and in a second end position of the first (29) / second actuating element (30), a fluid connection between the control device (15) and at least one drainage channel (38, 38a, 38b, 39, 39a, 39b, 40), in particular between one of the first (29) 29) / second actuator (30) associated first (27) / second actuating line (28) and a first (38) / second drainage channel (39) is released. 13. connecting rod (100) according to one of claims 1 to 12, characterized in that the first actuating element (29) and the second actuating element (30) via a coupling element (42) are operatively connected to each other, wherein preferably the coupling element (42) within the Conrod (100), particularly preferably within a bearing cap (26) of the connecting rod (100) is arranged. 14. connecting rod (100) according to claim 13, characterized in that by means of the coupling element (42) via the movement of one of the actuating elements (29, 30) in a first end position, the other of the actuating elements (29, 30) in one of a first end position different second end position can be brought, and vice versa. 15. connecting rod (100) according to one of claims 1 to 14, characterized in that the control device (15) has an actuating piston (19) which is arranged between a first switching position and a second switching position axially displaceable in a control chamber (18), wherein the control chamber (18) with at least one actuating line (27, 28) is fluidly connected or flow-connected. 16. Connecting rod (100) according to claim 15, characterized in that the control chamber (18) of the control device (15) is designed as a double-acting control chamber, wherein the control chamber (18) of the control device (15) via a first actuating line (27) and a second actuating line (28) with the actuating device (25) operatively connected or operatively connected, wherein the actuating piston (19) divides the control chamber (18) into a first control pressure chamber (18a) and a second control pressure chamber (18b), wherein the first control pressure space (18a) is flow-connected or flow-connectable to the first actuation line (27) and the second control pressure space (18b) is flow-connected to the second actuation line (28). 17. connecting rod (100) according to one of claims 1 to 16, characterized in that the length adjustment device (6) at least one cylinder chamber (7), at least one piston (8) and a first hydraulic working space (9) and a second hydraulic working space ( 10), wherein in a first switching state of the control device (15) a hydraulic medium return from the second working space (10) is locked and the first working space (9) is drained and in a second switching state of the second working space (10) is drained and a hydraulic fluid return from the first working space (9) is locked. 18. connecting rod (100) according to claim 17, characterized in that the connecting rod (100) has at least one second hydraulic medium supply line (13) which is connected to the first working space (9) and the second working space (10), wherein the connecting rod ( 100), in particular the control device (15) is designed such that in a first switching state of the control device (15) the second working space (10) via the second hydraulic medium supply line (13) can be filled with hydraulic medium and in a second switching state of the control device (15 ), the first working space (9) via the second hydraulic medium supply line (13) can be filled with hydraulic medium. 19. A reciprocating piston engine, in particular reciprocating internal combustion engine, with at least one connecting rod (100) according to one of claims 1 to 18. 20. A reciprocating engine according to claim 19, characterized in that the actuating device (25) by a stationary arranged in the crankcase actuator device (43) is switchable between the first and the second operating position. 21. A reciprocating piston engine according to claim 20, characterized in that the actuator device (43) has a first actuator element (45, 46, 47, 48, 49, 50) and a second actuator element (45, 46, 47, 48, 49, 50) wherein the first actuating element (29) with the first actuator element (45, 47, 49) is actuated and the second actuating element (30) with the second actuator element (46, 48, 50) is actuated. 22. A reciprocating piston engine according to claim 21, characterized in that the at least one actuator element (45, 46) at least one about a preferably parallel to the crankshaft axis (200a) extending axis of rotation (44, 44 ') rotatable cams (45, 46). 23. A reciprocating piston engine according to claim 22, characterized in that the actuating element (29, 30) directly with the cam (45, 46) or via an intermediate cam (45, 46) and actuating element (29, 30) arranged intermediate element (47, 48 ), which is preferably designed as a bucket tappet, can be actuated. 24. Reciprocating piston engine according to one of claims 19 to 21, characterized in that the actuator element (43) as in a direction normal to the crankshaft axis movable switching ramp (49, 50) is carried out, wherein preferably the switching ramp (49, 50) along its longitudinal extent a In the direction of the connecting rod towards continuously decreasing thickness, wherein particularly preferably of the crankshaft axis (200a) furthest removed area is made thickest. 25. Vehicle with a reciprocating piston engine, in particular with a reciprocating internal combustion engine, according to one of claims 19 to 24.