WO2017207671A1

WO2017207671A1 - Length-adjustable connecting rod, device for setting a compression ratio and internal combustion engine

Info

Publication number: WO2017207671A1
Application number: PCT/EP2017/063231
Authority: WO
Inventors: Andreas Krobath; Juergen PICHLER
Original assignee: Avl List Gmbh
Priority date: 2016-05-31
Filing date: 2017-05-31
Publication date: 2017-12-07
Also published as: WO2017205889A1

Abstract

The present invention relates to a length-adjustable connecting rod, to a device for setting a compression ratio and to an internal combustion engine. A length-adjustable connecting rod with a small connecting-rod eye and a large connecting-rod eye preferably has a switching device. The switching device is preferably designed to control the length of the connecting rod, in particular hydraulically. In addition, the connecting rod preferably has an adjustment device which is actuable, in particular mechanically, from outside the connecting rod, has a rotatably mounted adjustment unit and is designed to mechanically switch, in particular to actuate, the switching device by rotation of the adjustment unit.

Description

Length adjustable connecting rod, device for adjusting a

Compression ratio and internal combustion engine

The present invention relates to a length-adjustable connecting rod, a device for adjusting a compression ratio with such a connecting rod and an internal combustion engine with such a device.

To make vehicles, especially motor vehicles, more efficient and / or efficient, known from the prior art internal combustion engines with adjustable compression ratio. In this case, the positions of the upper and lower dead points of a cyclically up and down moving piston in a cylinder of the internal combustion engine is varied by the length of a connecting rod is changed accordingly. As a result, the cylinder volume can be adjusted variably. An internal combustion engine can thus be operated at full load with a low compression ratio and at partial load or during startup with an increased compression ratio, so that peak pressures can be reduced under full load, reduced fuel consumption at partial load or the compression pressure can be increased at startup.

To control the connecting rod length hydraulic systems are provided in some connecting rods, which move against each other displaceable parts of the connecting rod and / or can fix in a desired position. Usually, two hydraulic chambers are provided for this purpose, each of which can be charged with a hydraulic medium.

US 2013 0 247 879 A1 relates to an internal combustion engine with one or more connecting rods, each having an end piece for coupling to a crankshaft. An eccentric coupler couples the tail to a crankpin and has a rotary valve which projects into a receiving chamber. As a result, the receiving chamber is divided into several sections, so that filling a first Section with a liquid and dissipating the liquid from a second section rotates the rotary valve and thus the eccentric coupler in a first direction. A compression ratio regulator may be controlled to open a drainage channel of the first section so that oil from the first section may be delivered to the opposite or second section.

It is an object of the invention to provide an improved length-adjustable connecting rod, in particular a control mechanism for adjusting a connecting rod length to save space and / or reliably.

This object is achieved by a length-adjustable connecting rod, a device for adjusting a compression ratio and an internal combustion engine according to the independent claims. Advantageous embodiments of the invention are the subject of the dependent claims.

A first aspect of the invention relates to a, in particular hydraulically, length-adjustable connecting rod, in particular for an internal combustion engine, with a small connecting rod eye and a large connecting rod eye, which preferably has a switching device. The switching device is preferably adapted to control the length of the connecting rod, in particular hydraulically. In addition, the connecting rod preferably has an actuating device which can be actuated from outside the connecting rod, in particular mechanically, which has a rotatably mounted actuating unit and is set up to mechanically switch, in particular actuate, the switching device by rotating the actuating unit.

A second aspect of the invention relates to a device for adjusting a compression ratio in an internal combustion engine, in particular reciprocating piston engine, which preferably has a, in particular hydraulically, length-adjustable connecting rod according to the first aspect of the invention. In addition, the device preferably has an actuating device which is set up to actuate the setting unit, in particular mechanically, in particular to turn it. A third aspect of the invention relates to an internal combustion engine, in particular reciprocating engine, having a device for adjusting a compression ratio according to the second aspect of the invention.

A fourth aspect of the invention relates to a vehicle, in particular a motor vehicle, which has an internal combustion engine according to the third aspect of the invention.

The invention is particularly based on the approach, a switching device, which is preferably adapted to, in particular hydraulic, setting a length of a length-adjustable connecting rod, by means of a twisting, in particular by means of pivoting or a deflection, a rotatably mounted adjusting unit, which is part of an adjusting device to switch mechanically, in particular to operate. The rotation is preferably caused by an au outside the connecting rod caused mechanical actuation of the actuator

Due to the fact that the setting unit is rotatable, in particular pivotable or deflectable, the actuation of the switching device can be carried out, in particular reliably, carried out or executed. Preferably, one or more switching states of the switching device, which is preferably set up to control a flow of a hydraulic medium, reliably be mechanically activated or switched without the spatial position of the actuator relative to the switching device, the connecting rod or a connecting rod eye of the connecting rod at the activation or circuit changes. In particular, can be avoided by the rotatable bearings of the adjusting device that is necessary for activation or switching of the switching device additional space for movement of the adjusting device. In other words, the adjusting device may remain substantially congruent in the movement necessary for activating or switching the switching device.

The adjusting unit can during rotation transmit a moment to the switching device, in particular to a valve or a component of a valve of the switching device, which preferably causes the switching device to change the flow of the hydraulic medium through the connecting rod or Hydraulikkänale the connecting rod. Preferably, the moment may cause the switching device to generate a first hydraulic likkammer the connecting rod with the hydraulic medium to charge and a second hydraulic chamber of the connecting rod to empty or vice versa, or to pressurize the hydraulic medium in the first hydraulic chamber with a pressure which is higher than the pressure of the hydraulic medium in the second hydraulic chamber or vice versa. Thereby, the length of the connecting rod can be controlled reliably and a compression ratio in an internal combustion engine with such a connecting rod can be reliably adjusted.

Overall, the invention enables an improved length-adjustable connecting rod, in particular a reliable and / or space-saving operation of a switching device for controlling the connecting rod length.

Preferably, the actuating unit is arranged along a contour of the connecting rod, so that protruding or protruding beyond the contour of the connecting rod also during actuation of the actuating unit, in particular during rotation or pivoting or deflection of the actuator, avoided or at least reduced , Advantageously, the adjusting unit can be arranged along the contour in such a way that only little space is required.

In an advantageous embodiment, the connecting rod further comprises a hydraulically operated length adjustment, which is adapted to adjust the length of the connecting rod. Preferably, the switching device is thereby configured to control a flow of a hydraulic medium for operating the length adjustment device. For this purpose, the switching device may have, for example, one or more valves which can be opened or closed by means of mechanical actuation by the actuating unit. As a result, the length of the connecting rod can be reliably adjusted.

In a further advantageous embodiment, the actuating unit on an annular slide, which is rotatably mounted around the large connecting rod eye of the connecting rod around and is adapted to transmit a recorded from au ßerhalb the connecting rod switching pulse to the switching device. Preferably, the annular slide is semicircular or annular and coaxial with the large connecting rod eye. orderly. Particularly preferably, the annular slide has an inner diameter which substantially corresponds to the diameter of the large connecting-rod eye.

As a result, the setting unit or the annular slide can be adapted to the contour of the connecting rod and takes up only little space.

Preferably, the actuator or the slide ring is acted upon actuation with a moment from au ßerhalb the connecting rod and thereby rotated, in particular pivoted or deflected. As a result of the rotation, the setting unit or the annular slide transmits the torque, preferably substantially unimpeded, to the switching device or devices which, by means of the transmitted torque, can adjust the length of the connecting rod or control the flow of the hydraulic medium. As a result, the switching device can be reliably switched, in particular actuated, or the length of the connecting rod can be reliably adjusted.

In a further advantageous embodiment, the annular slide has a first half-ring-shaped ring element, in a variant, a first half-ring-shaped ring element and a second half-ring-shaped ring element. Preferably, the adjusting device further comprises two along the connecting rod, in particular along a Pleuellängsachse, slidably mounted adjusting elements. In a variant in which a first half-ring-shaped ring element is arranged to be movable about the half of the large connecting rod facing the small connecting rod eye, piston-side ends of the adjusting elements facing the small connecting rod eye cooperate with the ends of the first half-ring-shaped ring element facing away from the small connecting rod eye.

In the variant with the first half-ring-shaped ring element and the second half-ring-shaped ring element engage piston-side ends of the adjusting elements in each case between the first and second ring element.

As a result, an up or down movement of the adjusting elements along the connecting rod, in particular along the connecting rod longitudinal axis, reliably cause a rotation of the annular slide. In particular, a torque applied from outside the connecting rod to at least one of the adjusting elements, in particular a pulse, can be reliably transmitted to the switching device, in particular by being converted into a torque of the annular slide. Preferably, the first and second ring element are formed as a common part. As a result, the first and second ring element are acceleration neutral to each other.

The arrangement described above allows the actuating pulse reliably from a region of the large connecting rod facing away from the small connecting rod eye, in particular from a region of the crankshaft, into a region of the large connecting rod eye facing the small connecting rod eye, in particular in a region between the small and large connecting rod eye, to transfer or direct. In this case, the components of the adjusting device can be arranged space-saving and / or operated, i. be moved.

In a further advantageous embodiment, the switching device has at least one check valve for regulating the flow of the hydraulic medium. Preferably, the at least one check valve is arranged or arranged to prevent emptying of one or more hydraulic chambers of the connecting rod, in particular the length adjustment, in a closed state and / or to allow in an open state. Preferably, the adjusting device is designed to transfer the at least one check valve from the closed state to the open state and vice versa, or to keep it in the closed state and / or the opened state. As a result, the flow of the hydraulic medium in the connecting rod, in particular through hydraulic channels, in particular into or out of hydraulic chambers, can be reliably controlled.

Alternatively or additionally, the switching device can also have at least one slide valve for regulating the flow of the hydraulic medium. Analogous to the above embodiment, the actuator may be configured to actuate the at least one spool valve, i. to control the opening and closing of the valve.

In a further advantageous embodiment, the at least one check valve is designed as a ball valve. Preferably, the adjusting device is adapted to lift a ball of the at least one ball valve from a valve seat of the at least one ball valve by rotating the actuator or release the valve seat by rotating the actuator. Preferably, the adjusting device or the switching device to one or more valve pins, which are preferably at least partially arranged in each case a hydraulic channel. Particularly preferred the valve pin or pins moved by interaction with the actuator in the manner, in particular axially displaced that the ball can be lifted from the valve seat against a pressure of the hydraulic medium and / or against a spring tension of a locking spring and the valve seat is released. As a result, the at least one check valve can be reliably actuated, ie opened or closed, and the inflow and outflow of hydraulic medium can be controlled from one or more or into one or more hydraulic chambers.

In a further advantageous embodiment, the setting unit has a ramp which is set up for actuating the switching device, in particular a valve of the switching device. Preferably, the ramp is adapted to interact with at least one valve pin of the actuating device or the switching device. In particular, while an end of the valve pin is guided over the ramp in such a way that the valve pin moves, in particular axially displaced, and thereby actuate at least one valve, in particular check valve, the switching device. By the ramp, a rotational movement, in particular pivoting movement of the adjusting unit can be easily and reliably, in particular space-saving, converted into a translational movement for actuating the switching device.

In a further advantageous embodiment, the connecting rod has a locking device, which is adapted to fix the adjusting device in a setting state. This allows the operation of the switching device over a predetermined period. In particular, at least one valve of the switching device can thereby be opened or kept open at least until the hydraulic medium has drained from a hydraulic chamber. Thus, a reliable adjustment of the length of the connecting rod is made possible.

In a further advantageous embodiment, the adjusting device, in particular the setting unit and / or at least one of the adjusting elements, at least one locking recess. Preferably, the locking device further comprises at least one clampable locking pin. The at least one locking recess is preferably arranged such, in particular on the setting unit and / or on at least one of the adjusting elements, that the locking pin engages in a locking state in the locking recess. Preferably, the locking pin is made of spring steel wire and arranged so that it can engage in a transverse to a longitudinal axis of the adjusting elements arranged groove. Alternatively or additionally, the locking pin is clamped with a spring element and arranged such that it can engage with one end in the at least one, preferably blind hole-like, Arretierungsausnehmung.

As a result, the adjusting device, in particular the setting unit and / or at least one of the adjusting elements, even during the cyclical movement along a trajectory of the connecting rod during operation of an internal combustion engine allow reliable operation of the switching device, in particular over a predetermined period.

In an advantageous embodiment of the device for setting a compression ratio, the actuating device is designed as a rocker switch with at least one rocking axis. In this case, the actuating device preferably has a rocker head with two active surfaces which can be coupled to the actuating device such that tilting of the rocker head causes the actuating unit to rotate. The rocker head is preferably designed such that in each case one adjusting elements of the adjusting device can interact with one of the two active surfaces.

Preferably, the actuating device is arranged in such a manner that the adjusting means of the connecting rod connected to a crankshaft of the internal combustion engine interact with at least one of the two active surfaces during cyclical movement along a trajectory during operation of the internal combustion engine at a predetermined point of the trajectory, in particular one by the actuating device can accommodate mediated actuation pulse can.

Preferably, a corresponding switching state of the switching device is activated by a predetermined tilt position of the rocker head. In other words, various switching states of the switching device can be switched by tilting the rocker head.

The aforementioned embodiments and arrangements of the actuating device enable a reliable actuation of the actuating device of the connecting rod, in particular the transmission of an actuating pulse to the actuating device. In a further advantageous embodiment of the rocker head sits on the rocking axis rotationally fixed or is rotatably mounted on the rocking axis. Preferably, the rocker head can be tilted by means of an actuator, which is connected to the rocking axis or the rocker head via a rocker lever. This allows a precise tilting of the rocker head and thus reliable operation of the adjusting device.

In a further advantageous embodiment, the actuating device is designed as a switching platform with at least two actuating elements. Preferably, each actuating element has an active surface, which can be moved in a direction perpendicular to the eccentric axis by means of an eccentric element which is seated on an eccentric axis. Preferably, a plurality of, in particular two, eccentric axes are mechanically connected to one another in such a manner that in each case two actuating elements for actuating an actuating device can be moved in opposite directions or can only move in opposite directions. This ensures that only one of the actuating elements with the adjusting device, in particular an actuating element, can interact.

The features and advantages described in relation to the first aspect of the invention and its advantageous embodiment apply, where technically reasonable, also for the second, third and fourth aspects of the invention and its advantageous embodiment and vice versa.

Further features, advantages and possible applications of the invention will become apparent from the following description in conjunction with the figures, in which the same reference numerals for the same or corresponding elements of the invention are used throughout. At least partially schematically show:

Fig. 1 a shows a first preferred embodiment of an actuating device in a first position;

Fig. 1 b, the embodiment of Figure 1 a in a second position. 2 shows a second preferred embodiment of an adjusting device.

Fig. 3 shows a preferred embodiment of a switching device;

4a shows a first preferred embodiment of a locking device in three-dimensional representation;

4b, the locking device of Figure 4a in a plan view.

5a shows a second preferred embodiment of a locking device in three-dimensional representation;

FIG. 5b shows the locking device from FIG. 5a in a plan view; FIG.

Fig. 6 shows a preferred embodiment of a part of a length-adjustable

Connecting rod in an exploded view;

7 shows a first preferred embodiment of an actuating device in an exploded view;

Fig. 8 shows a preferred embodiment of a device for setting a compression ratio;

9 shows a second preferred embodiment of an actuating device;

10 shows a third preferred embodiment of an actuating device;

Fig. 1 1 to 13, an oil scheme for a hydraulically switched switching mechanism for the shift paddles shown in Figures 8 to 10 ..;

14 and 15, an electrical switching mechanism for the shift paddles according to FIGS. 8 to 10. Figures 1a and 1b show a first preferred embodiment of an adjusting device 20 of a length-adjustable connecting rod (not shown), which is adapted to switch a switching device 10 mechanically. The switching device 10 preferably has check valves 11, 11 ', which are designed to control the flow of hydraulic medium through hydraulic channels 12 of a length adjustment device 50. The hydraulic channels 12 can open into a first hydraulic chamber 4 and a second hydraulic chamber 5 of the length adjustment device 50, which can be formed by a hydraulic cylinder 6 of the connecting rod and a hydraulic piston 7 of the connecting rod, in particular a reciprocating piston acting on both sides.

In Figure 1 a, the switching device 10 is in a first switching state (state A), in which hydraulic medium from the second hydraulic chamber 5 via an operable by the switching device 20, open check valve 1 1 'can flow. The first hydraulic chamber 4 preferably via a supply channel 13 supplied, in particular pressurized, hydraulic medium can therefore cause a movement of the hydraulic piston 7 in a large connecting rod 3 of the connecting rod remote direction, indicated by the arrow 7 '. Accordingly, also connected to the hydraulic piston 7 small connecting rod eye (not shown) of the connecting rod is moved. If the hydraulic piston 7 abuts a first end face 6 'of the hydraulic cylinder 6 facing away from the large connecting rod eye 3, the connecting rod has its maximum length.

In Figure 1 b, the switching device 10 is in a second switching state (state B), in which hydraulic medium from the first hydraulic chamber 4 via an operable by the switching device 20, open check valve 1 1 'can flow. The second hydraulic chamber 5 preferably via the inflow channel 13 supplied, in particular pressurized, hydraulic medium can therefore cause a movement of the hydraulic piston 7 in the large connecting rod 3 of the connecting rod facing direction, indicated by the arrow 7 '. Accordingly, the small connecting rod eye connected to the hydraulic piston 7 is also moved. If the hydraulic piston 7 abuts against a second end face 6 "of the hydraulic cylinder 6 facing the large connecting rod eye 3, the connecting rod has its minimum length. To switch the switching device 10, in particular for the mechanical actuation of the valves 1 1 ', in particular for transferring the switching device 1 0 in the first or second switching state, the actuating device 20 has an actuating unit 21. This preferably has an annular slide 21 ', which is preferably formed substantially annular and with the large connecting rod 3 is preferably arranged coaxially (perpendicular to the plane of the figure) on. Furthermore, the adjusting unit 21 or the annular slide 21 'preferably has a ramp 22 arranged in the region of the switching device 10. The adjusting unit 21 is preferably rotatable along its circumferential direction, in particular pivotable or deflectable, arranged such that the ramp 22 can interact with one of a plurality of, in the example shown, two valve pins 14 for opening the check valves 1 1 '.

The actuating unit 21 is preferably configured to displace the valve pins 14 substantially perpendicular to the circumferential direction of the actuating unit 21 by means of the ramp 22. Preferably, the check valves 11, 11 'are designed as ball valves 15, so that a valve pin 14 can lift a ball 15' of a ball valve 15 from a valve seat 15 "of the ball valve 15. Thus, the hydraulic medium can flow through a discharge channel 16 between the ball 15 and the valve seat 15 "flow through.

To rotate the actuator 21, this is preferably connected to two actuators 23. Preferably, the two adjusting elements 23 engage substantially tangentially in the setting unit 21, so that a movement of the adjusting elements 23 along the arrows 23 'exerts a torque on the setting unit 21 and causes a rotation of the setting unit 21.

Preferably, the adjusting elements 23 are actuated from outside the connecting rod by means of an actuating device (not shown). The arrangement shown in FIGS. 1 a and 1 b makes it possible to transmit a switching pulse received by the adjusting elements 23, in particular around the large connecting rod eye 3, to the switching device 10, in particular a check valve 11. During the movement of the switching unit 21 during the switching process, ie during the rotation, this may remain substantially congruent, so that act in the operation of an internal combustion engine substantially constant mass nkräfte on the connecting rod. FIG. 2 shows a second preferred exemplary embodiment of an actuating device 20 with an actuating unit 21. The adjusting unit 21 is preferably arranged around a large connecting rod 3 of a (only partially shown) connecting rod 1 and formed as an annular slide 21 '. The annular slide 21 'has in particular a first semi-annular ring member 21 a and a second semi-annular ring member 21 b, which are preferably designed as identical parts and therefore are acceleration-neutral. Between the ends of the ring elements 21 a, 21 b preferably engage the a small connecting rod (not shown) of the connecting rod 1 facing ends 24 of actuators 23, so that a displacement of the adjusting elements 23 along a Pleuellängsachse X causes a rotation of the actuator 21.

In a variant of the invention, only a first half-ring-shaped annular element 21 a is provided, which is arranged around a small connecting rod eye facing half of the large connecting rod 3 movable, in particular rotatable. In this variant, the small connecting rod eye (not shown) of the connecting rod 1 facing ends 24 of the actuating elements 23 with remote from the small connecting rod 2 ends 210 a, 21 1 a of the first semi-annular ring member 21 a act together and cause a rotation of the actuator 21st This variant is indicated by the weaker line width of the second semi-annular ring element 21 b.

Preferably, the adjusting elements 23 are guided by housing sleeves 9 of the connecting rod 1, which extend substantially parallel to the Pleuellängsachse X.

Preferably, the first and second ring member 21 a, 21 b, in particular three, in each case in the circumferential direction of the adjusting unit 21 extending slots 25. By means of the slots 25 by cross-locking screws 26, the adjusting unit 21, in particular the first and second ring member 21 a, 21 b are rotatably mounted on the connecting rod 1.

FIG. 3 shows a preferred exemplary embodiment of a switching device 10 with a ball valve 15. Preferably, when the ball valve 15 is closed, a ball 15 'of the ball valve rests on a valve seat 15 "of the ball valve 15 and prevents the outflow of hydraulic fluid from a hydraulic chamber (not shown) through a drainage channel 16 in the direction of the arrow Ball 15 'secured by a securing spring 17 of the ball valve 15 on the valve seat 15 ".

The ball valve 15 can be opened by lifting the ball 15 from the valve seat 15 "in the direction of the discharge channel 16 by means of a valve pin 14. The valve pin 14 preferably has a pin sleeve 14 'for lifting the ball 15' from the valve seat 15" and a pin plate 14 ", which are braced against each other by means of a disc spring 18. Preferably, when the valve pin 14 is actuated by an actuating unit 21, the plate spring 18 dampens a portion of the loads acting on the valve pin 14, in particular on the pin sleeve 14 ', in particular in the direction of FIG Ball 15 'acting forces.

The actuation of the switching device 10, i. the movement of the valve pin 14 to open the ball valve 15 is preferably effected by the interaction of a ramp 22 of the actuator 21 with a collar 19 of the pin plate 14 "., the actuator unit 21 twists, ie the actuator unit 21 moves in a direction perpendicular to the plane of the figure , the collar 19 can be guided over the ramp 22 and the pin plate 14 "in the direction of the ball 15 'are moved. The plate spring 18 is preferably stiff enough to the pin sleeve 14 'and the contacted by the pin sleeve 14' ball 15 'against the of the hydraulic medium in the drain channel 16 and by the securing spring 17 on the ball 15' pressure exerted by the valve seat 15th "take off.

Figures 4a and 4b show a first preferred embodiment of a locking device 30, which is adapted for fixing an adjusting device 20. FIG. 4a shows a three-dimensional representation and FIG. 4b shows a top view.

The locking device 30 preferably has a braced with a spring means 32 locking pin 31. The locking pin 31 and the spring means 32 are arranged in a bore 33 of a connecting rod 1 partially shown. The drilling tion 33 is preferably closed with a locking screw 34, against which the locking pin 31 is supported.

As a result of the tensioning, the locking pin 31 can be pressed into a locking recess 27 of the setting unit 21, as a result of which the setting unit 21 can be fixed in a setting state which preferably corresponds to a switching state of a switching device, not shown. If a sufficiently high torque is applied to the setting unit 21, the locking pin 31 can be pushed out of the locking recess 27 against a spring force of the spring means 32 and the setting unit 21 can be transferred into another setting state.

FIGS. 5a and 5b show a second preferred exemplary embodiment of a locking device 30, which is set up to fix an adjusting device 20. Figure 5a shows a three-dimensional representation and Figure 5b is a plan view.

The locking device 30 preferably has a bracing locking pin 31, which is preferably arranged perpendicular to an actuating element 23 of an actuating device 20 and can engage in a locking recess 27 of the actuating element 23. The locking recess 27 is formed in particular as a groove which, like the locking pin 31, preferably runs perpendicular to a connecting rod longitudinal axis X.

The locking pin 31 is preferably made of spring steel and deformable, in particular bendable formed. Acts on the actuator 23 is a sufficiently large force, for example, by a given outside of a connecting rod 1 shown actuating pulse, the locking pin 31 can be pushed out under tension from the locking pin 27, so that the actuator 23 along the Pleuellängsachse X move, especially in another setting state can be delivered.

Figure 6 shows a preferred embodiment of a portion of a length-adjustable connecting rod 1 with a switching device 10 and an adjusting device 20 in an exploded view. The part of the connecting rod 1 shown has a large connecting rod eye 3 on, which is formed by two by means of a bearing cap 1 'secured bearing shells 3', wherein the bearing cap 1 'can be connected by two connecting rod 8 with the connecting rod 1.

Preferably, the switching device 10, in particular two, actuatable by the actuator 20 check valves 1 1 'on. These are preferably arranged in a region of the Pleuelauges 3, which is the bearing cap 1 'opposite.

To actuate the switching device 10 and the check valves 1 1 ', the adjusting device 20 preferably has an actuating unit 21 with a first half-ring-shaped ring member 21 a and a second semi-annular ring member 21 b, which surround the large connecting rod 3 and thereby an actuating pulse, in particular from a region of the large Pleuelauges 3, which the check valves 1 1 'opposite, can be transferred to the check valves 1 1'.

The first ring member 21 a preferably has a ramp (not shown) for actuating the check valves 1 1 'and is mounted by means of a guide plate 26' rotatably mounted on the connecting rod 1. The second ring element 21 b preferably has three elongated holes 25 extending in the circumferential direction of the second ring element 21b, which can be penetrated by guide screws 26 for rotatable, in particular pivotable or deflectable, mounting of the second ring element 21b on the bearing cap 1 '.

Preferably, the adjusting device 20 has two adjusting elements 23, wherein in each case a bearing cover 1 'facing away from end 24 of the adjusting elements 23 between one end of the first ring member 21 a and one end of the second ring member 21 b is arranged. Thereby, a movement of the adjusting elements 23 along a Pleuellängsachse X in a movement of the actuator 21 along a circumferential direction of the actuator 21, i. in a rotation of the actuator 21, to be converted.

The bearing cap 1 'has a region of through bores for receiving the connecting rod bolts 8 preferably each having a housing sleeve 9, which is adapted to is to receive an actuator 23 and to guide along the Pleuellängsachse X slidably.

The connecting rod 1 preferably also has a locking device 30 for fixing the actuating device 20 in a setting state, in which, for example, an actuatable by the actuator 21 check valve 1 1 'remains open.

The length-adjustable connecting rod 1 also has a hydraulic piston (not shown), which is connected via a shaft (not shown) with a small connecting rod eye (not shown). The small connecting rod eye is arranged on a large connecting rod 3 opposite end of the connecting rod 1.

The hydraulic piston is displaceably arranged in a hydraulic cylinder 6, so that hydraulic piston and hydraulic cylinder 6 form a first and second hydraulic chamber (not shown) which can be charged with a hydraulic medium. By operating the switching device 10, the flow of the hydraulic medium into and out of the hydraulic chambers can be controlled in such a way that the hydraulic piston and thus the small connecting rod eye moves along the longitudinal axis Pleuellängsachse X, whereby the total length of the connecting rod 1 changes.

The arrangement of the components of the connecting rod 1 or its embodiment shown in FIG. 6 is advantageously suitable for applying an actuating pulse to the actuating device 20 in the region of the large connecting rod 3, in particular in the region of a side of the large connecting rod 3 remote from the small connecting rod eye. in particular on at least one of the adjusting elements 23, is transmitted to the in the region of the large connecting rod 3, in particular in the region of the small connecting rod facing side of the large connecting rod 3, arranged switching device 10 to transmit.

Figure 7 shows a first embodiment of an actuator 40 in an exploded view. The actuating device 40 is designed as a switching rocker 41 and preferably has a rocker head 42 which is tiltably mounted on a rocking axis 43. The rocker head 42 preferably has two active surfaces 44, which can be brought into engagement with an adjusting device, in particular two adjusting elements, of a length-adjustable connecting rod (not shown). Preferably, an actuating pulse is transmitted through one of the two active surfaces 44 on one of the two actuating elements, wherein the actuating pulse preferably depends on a tilted position of the rocker head 42 and is mediated.

The rocker head 42 can be spent by means of an actuator 45 in different tilt positions, each tilting position corresponds to a setting state of the adjusting device or a switching state of a switching device of the connecting rod (not shown) and thus a total length of the connecting rod. The actuator 45 is preferably connected to a rocker arm 46 of the rocker head 42.

The actuator 45 can preferably be controlled hydraulically, pneumatically, electrically or by means of negative pressure.

8 shows an embodiment of a device 100 for adjusting a compression ratio of an internal combustion engine with length-adjustable connecting rods 1 and an actuator 40 for actuating actuators 20 of the connecting rods 1 is shown. The actuating device 40 is designed as a switching rocker 41, which is arranged in the region of a crankshaft 52 of the internal combustion engine.

The crankshaft 52 preferably carries four length-adjustable connecting rods 1, which pivotably rest on crankpins (not shown) of the crankshaft 52. Upon rotation of the crankshaft 52, the connecting rods 1, in particular a large connecting rod eye 3 or a region on a side facing away from a small connecting rod 2 side of the large connecting rod eye 3, preferably a predetermined trajectory.

The switching rocker 41 is arranged on the crankshaft 52 in such a manner that actuating elements 23 of the adjusting devices 20 of the connecting rods 1 interact with active surfaces 44 of a rocker head 42 of the rocker 41 at one point of the predetermined trajectory. As a result, depending on the tilted position of the rocker heads 42, on the one point of the predetermined trajectory a switching pulse to the actuators 20 of the connecting rods 1 are transmitted or the actuators 20 are actuated from outside the connecting rod 1.

To set the tilting position of the rocker heads 42, these preferably sit rotationally fixed or secured against rotation on a rocking axis 43. The rocker axis 43 preferably has a rocker lever 46, which may be connected to an actuator 45 for setting the tilted position.

FIG. 9 shows a second exemplary embodiment of an actuating device 40 designed as a switching rocker 41. In this case, a tilting position of rocker heads 42 of the rocker 41, which are preferably mounted pivotable or tiltable on a rocker axis 43, are adjusted by actuators 45, which are connected opposite of active surfaces 44 of the rocker heads 42 with the rocker heads of 42.

By the embodiment shown in Figure 9, the rocker heads 42 can be spent independently in each case in a predetermined tilted position and thus the length of length-adjustable connecting rods on a crankshaft of an internal combustion engine can be adjusted individually.

FIG. 10 shows a third exemplary embodiment of an actuating device designed as a switching stage 53, which has in each case two actuating elements 47 for actuating an adjusting device of a length-adjustable connecting rod. Preferably, each of the actuating elements 47 has an active surface 44 for interaction with in each case one actuating element of the actuating device.

The actuating elements 47 are preferably movable in a direction perpendicular to eccentric axes 49 of the switching stage 53, in particular extendable, mounted. In order to be able to actuate an adjusting element of the adjusting device, the actuating elements 47 can preferably be arranged by means of eccentric elements 48 which are mounted in a rotationally fixed manner on the eccentric axes 49 and which each have an opposite side to the active surface 44 the actuators 47 interact, are moved from a retracted state to an extended state and vice versa.

The eccentric shafts 49 may be mechanically connected to each other, in particular via mutually engaged friction or gears 51st At least one of the friction or toothed wheels 51 can be connected to an actuator 45 in order to set the eccentric axes 49 in rotation and thus to control the movement or the retraction and / or extension of the actuating elements 47.

11 shows an oil scheme for a hydraulically switched switching mechanism for the rocker switch according to FIG. 9. The rocker switch is hydraulically connected via actuator pistons (multiple actuators).

(1) a Hauptölgallery, (2) a pressure accumulator, (3) a check valve, (4) a 4/3-way valve (electrically controlled), (5) a hydraulic Aktuatorkolben for the rocker (multiple actuators), ( 6) an oil pan and (7) a mechanically actuated VCR connecting rod.

FIG. 12 shows an oil scheme for a hydraulically switched shift mechanism for the shift paddles according to FIG. 8. The shift paddles are arranged on a common shaft. The adjustment is made by a hydraulic actuator (Einzelaktuator).

Notwithstanding Fig. 1 1 denotes (5) a hydraulic single actuator for the shift paddles, (6) the shift paddles, (7) a mechanically actuated VCR connecting rod and (8) an oil pan.

FIG. 13 shows an oil scheme for a hydraulically switched shift mechanism for the shift paddles according to FIG. 10. There are separate shift paddles per shift pin. The adjustment is made by a hydraulic actuator (Einzelaktuator).

The designations correspond to those from FIG. 12. Figure 14 shows an electrical switching mechanism for the shift paddles of FIG. 8. The shift paddles are arranged on a common shaft. The adjustment is made by an electric actuator (Einzelaktuator).

(1) an oil supply for the crankshaft / the VCR connecting rod, (2) an ECU (engine control unit), (3) an electric servomotor, (4) the shift paddles and (5) a mechanically actuated VCR connecting rod.

FIG. 15 shows an electrical switching mechanism for the shift paddles according to FIG. 10. There are separate shift paddles per shift pin. The adjustment is made by an electric actuator (Einzelaktuator). The designations correspond to those of FIG. 14.

Connecting rod

'Bearing cap

small connecting rod eye

big connecting rod eye

first hydraulic chamber

second hydraulic chamber

hydraulic cylinders

'first face

"second front page

hydraulic pistons

'Direction of movement of the hydraulic piston

connecting rod

housing sleeves

0 switching device

1 check valve

1 'operable by the actuator check valve 2 hydraulic channels

3 inflow channel

4 valve pin

4 'pin sleeve

4 "pin plate

5 ball valve

5 'ball

5 "valve seat

6 drainage channel

7 securing spring

8 plate spring

9 fret

0 adjusting device

1 actuator 'Ring slide

a first ring element

Oa, 21 1 a ends of the first ring element b second ring element

ramp

actuators

End of the control elements

Long hole

locking screws

securing recess

locking device

locking pin

spring element

drilling

Screw

actuator

rocker

rocker head

rocking axis

effective area

actuator

rocker lever

actuator

eccentric

length adjustment

Friction or gear

crankshaft

switching stage

Pleuellängsachse

Claims

claims

Length-adjustable connecting rod (1), in particular for an internal combustion engine, with a small connecting rod eye (2) and a large connecting rod eye (3), comprising

- A switching device (10) which is adapted to control the length of the connecting rod (1); and

- One from outside of the connecting rod (1), in particular mechanically actuated adjusting device (20) which has a rotatably mounted adjusting unit (21) and is adapted to switch the switching device (10) by turning the adjusting unit (21) mechanically.

Connecting rod (1) according to claim 1, further comprising a hydraulically operable Längenverstelleinrichtung (50) which is adapted to adjust the length of the connecting rod (1), wherein the switching device (10) is adapted to a flow of a hydraulic medium for operating the length adjustment (50) to steer.

Connecting rod (1) according to one of the preceding claims, wherein the adjusting unit (21) has a ring slide (21 ') which is rotatably mounted around the large connecting rod eye (3) of the connecting rod (1) and adapted to a from outside ßerhalb Connecting rod (1) recorded switching pulse to the switching device (10) to transmit.

Connecting rod (1) according to claim 3, wherein the annular slide (21 ') has a first semi-annular ring element (21 a), which is preferably arranged around a small connecting rod eye (2) facing half of the large connecting rod eye (3), wherein the Setting device (20) further comprises two along the connecting rod (1) slidably mounted adjusting elements (23), the small connecting rod eye (2) facing ends with the small connecting rod (2) opposite ends of the first half-ring-shaped ring element (21 a) cooperate. Connecting rod (1) according to claim 3, wherein the annular slide (21 ') has a first half-ring-shaped ring element (21 a) and a second half-ring-shaped ring element (21 b) and the adjusting device (20) further comprises two along the connecting rod slidably mounted adjusting elements ( 23), whose small connecting rod eye (2) facing ends in each case between the first and second ring element (21 a, 21 b) engage.

Connecting rod (1) according to one of the preceding claims, wherein the switching device (10) has at least one check valve (1 1) for regulating the flow of the hydraulic medium.

Connecting rod (1) according to claim 6, wherein the at least one check valve (1 1) as a ball valve (15) and the adjusting device (20) is adapted to a ball (15 ') of the at least one ball valve (15) of a valve seat ( 15 ") of the at least one ball valve (15) by turning the actuator (21) lift or release the valve seat (15") by rotating the actuator (21).

Connecting rod (1) according to one of the preceding claims, wherein the adjusting unit (21) has a ramp (22) which is adapted to actuate the switching device (10).

Connecting rod (1) according to one of the preceding claims with a locking device (30) which is adapted to fix the adjusting device (20) in a setting state.

The connecting rod (1) according to claim 9, wherein the adjusting device (20) has at least one locking recess (27) and the locking device (30) at least one bracing locking pin (31), and wherein the at least one locking recess (27) is arranged such that the Locking pin (31) engages in a locking state in the locking recess (27).

Device (100) for adjusting a compression ratio in an internal combustion engine, in particular a reciprocating piston engine, comprising:

- a length-adjustable connecting rod (1) according to one of the preceding Claims; and

- An actuating device (40) which is adapted to actuate the actuating unit (20) mechanically, in particular to rotate.

12. Device (100) according to claim 1 1, wherein the actuating device (40) as 5 switching rocker (41) is formed and a rocker head (42) having two active surfaces (44), which in such a manner with the actuating device (20) can be coupled, a tilting of the rocker head (42) causes the adjusting unit (21) to rotate.

13. Device (100) according to claim 12, wherein the rocker head (42) is rotationally fixed on a rocking spindle (43) or rotatably supported and by means of an actuator (45), which with the rocking axis (43) or rocker head ( 42) via a rocker lever (46) is connected, can be tilted.

14. Device (100) according to claim 11, wherein the actuating device (40) is designed as a switching platform (53) with at least two actuating elements (47),

Wherein each actuating element has an active surface (44) which can be moved in a direction perpendicular to the eccentric axis (49) by means of an eccentric element (48) which is seated on an eccentric axis (49).

15. Internal combustion engine, in particular reciprocating engine, with a device (100) for setting a compression ratio according to one of An¬

20 claims 1 1 to 14.