WO2018019514A1 - Connecting rod for an internal combustion engine having variable compression - Google Patents

Abstract

The invention relates to a connecting rod (10) for an internal combustion engine having variable compression, comprising a connecting rod body (12), a connecting rod shaft (16) that has a connecting rod end (18) and is moveably guided in a longitudinal direction (L) of the connecting rod body (12), a connecting rod cover (14) and an eccentric adjustment device (20) for adjusting an effective connecting rod length (60). The eccentric adjustment device (20) is arranged in the connecting rod body (12) and has an eccentric (21) cooperating with at least one lever (24, 25). An adjustment path of the eccentric adjustment device (20) can be adjusted by means of a shifting valve (32), wherein the eccentric (4) can swivel about the rotational axis thereof, and wherein the at least one lever (24, 25) is swivelably connected to the connecting rod shaft (16).

Description

 Connecting rod for a variable compression internal combustion engine

Technical area

The invention relates to a connecting rod for an internal combustion engine with variable compression, in particular a motor vehicle, with an eccentric adjusting device for adjusting an effective connecting rod length, and an internal combustion engine with variable compression with a connecting rod.

State of the art

In internal combustion engines, a high compression ratio has a positive effect on the efficiency of the internal combustion engine. Under compression ratio is generally understood the ratio of the entire cylinder space before compression to the remaining cylinder space after compression. However, in internal combustion engines with spark ignition, in particular gasoline engines, which have a fixed compression ratio, the compression ratio may only be selected so high that a so-called "knocking" of the internal combustion engine is avoided during full load operation low cylinder filling, the compression ratio with higher values are selected without a "knocking" would occur. The important part load range of an internal combustion engine can be improved if the compression ratio is variably adjustable. To adjust the compression ratio, for example systems with variable connecting rod length are known, which operate with the aid of hydraulic switching valves an eccentric adjusting device of a connecting rod. A generic connecting rod is known for example from WO 2013/092364, which discloses a length-adjustable connecting rod for a reciprocating engine, in particular an internal combustion engine, with at least a first and a second rod part, which two rod parts telescopically zoom in and / or into each other. The second rod part forms a guide cylinder and the first rod part a longitudinally displaceable in the guide cylinder piston member. Between the first and the second rod part a high-pressure chamber is spanned, in which at least one first oil passage opens, in which at least one valve designed as a control valve is arranged, the actuator by a return spring in a first position and by oil pressure against the force of the return spring in a second position is displaced.

In contrast, WO 2010/108582 A1 discloses a connecting rod, in which an actuating device is arranged in the upper connecting rod eye. The actuator may also be placed on a central rod of the connecting rod and form the first connecting rod as the first connecting rod. The lower connecting rod eye is formed with the center rod of the connecting rod as a second connecting rod element. The connecting rod eye is the part of the connecting rod in which the piston pin is mounted. The actuating device comprises an eccentric, which carries the piston pin and is pivotally mounted in the upper connecting rod eye. The actuating device also comprises an actuating element, which can cause a pivoting of the eccentric about the central axis of the upper connecting rod eye. The piston pin is arranged eccentrically on the eccentric, and a pivoting of the eccentric about the central axis of the upper connecting rod causes a displacement of the piston pin along a circular path about this axis. The actuating element is designed as a swivel motor.

Disclosure of the invention

An object of the invention is to provide an improved connecting rod for a variable compression internal combustion engine with a robust and reliable adjustment mechanism having low space requirements.

Another object is to provide an internal combustion engine with such a connecting rod. The above objects are achieved according to one aspect of the invention with the features of the independent claims.

Favorable embodiments and advantages of the invention will become apparent from the others

Claims, the description and the drawing.

It is proposed a connecting rod for an internal combustion engine with variable compression, which comprises a Pleuelkörper, a displaceably guided in a longitudinal direction of the connecting rod connecting rod with a connecting rod, a connecting rod cover, and an eccentric adjusting device for adjusting an effective connecting rod length. The eccentric adjusting device is arranged in the connecting rod body and has an eccentric cooperating with at least one lever. An adjustment of the eccentric adjusting device is adjustable by means of a switching valve, wherein the eccentric is pivotable about its axis of rotation, and wherein the at least one lever is pivotally connected to the connecting rod.

The connecting rod according to the invention has the advantage that it allows the adjustment of the effective connecting rod length in a very compact design. In this case, the distance between the center axis of a lifting bearing eye arranged in the connecting rod (large connecting rod eye as the first joint) to the central axis of a small connecting-rod eye, which constitutes the second joint, and which forms a receptacle for a piston pin is referred to as the effective connecting-rod length. The connecting rod according to the invention allows the adjustment via a third joint in Pleuelkörper, which is connected to a telescopic rod, the connecting rod. The small connecting rod eye is arranged in the connecting rod, which is displaceable in the form of an extendable telescopic rod in the longitudinal direction of the connecting rod. Thus, the effective Pleuellänge can be changed by moving the connecting rod relative to the Pleuelkörper with the Bublagerauge. The displacement of the connecting rod takes place here by means of an eccentric adjusting device with an eccentric, which is connected via at least one lever to the connecting rod, so that an adjustment of the eccentric leads to a longitudinal displacement of the connecting rod. Preferably, the connecting rod can be connected via two levers with the eccentric, which are arranged on both flat sides of the connecting rod, so as to ensure a symmetrical introduction of force between the connecting rod and eccentric. The levers may be connected to the connecting rod by means of a bolt guided in a bore. By introducing a torque on the eccentric can be changed so the effective connecting rod length. The eccentric adjusting device can be hydraulically actuated, for example, wherein the hydraulic fluid can be controlled via a switching valve.

The connecting rod has the advantage that the interfaces to an internal combustion engine are maintained, so that a conventional connecting rod for variable compression can be exchanged for the connecting rod according to the invention. The connecting rod body is easy to manufacture, since no complicated to be machined hydraulic support chambers are provided. The connecting rod assembly has a low total weight and consists of few individual components and assembly steps. Thus, the connecting rod is well suited for mass production. The use of non-cranked levers facilitates the production and is also advantageously feasible in favorable serial production, for example by laser cutting. Drilling, which could weaken the structure of the connecting rod, accounts for the most part.

According to an advantageous embodiment, the eccentric adjusting device may comprise a pivoting motor which has a rotor mounted in a stator. At least one first support chamber and at least one second support chamber are formed between at least one rotor blade of the rotor and at least one stator blade, wherein a volume of the first support chamber and a volume of the second support chamber can be changed by an adjustment of rotor against stator complementary to each other.

The connecting rod can thus have a swivel motor in combination with an eccentric adjusting device for adjusting the effective connecting rod length. The use of a hydraulic swing motor, as used for example in camshaft adjusters, in conjunction with an eccentric bore in the rotor of the swing motor favors a very compact design of a length-adjustable connecting rod. The sealing of the support chambers of the slewing motor, which are usually operated with a hydraulic fluid under sometimes very high pressures, for example, over 1000 bar, thereby posing a design challenge. The swing motor itself can be arranged directly in the connecting rod body.

The swivel motor may advantageously have a rotor with at least one rotor blade and a stator with at least one stator wing. The rotor can be rotated on a common axis against the stator, so that the rotor blade against the Stator wing is twisted. Thus, at least one first support chamber and a second support chamber are formed between the rotor wing and the stator wing, the volume of which is variable continuously and complementarily with respect to one another when the rotor rotates against the stator. As the volume of the first support chamber increases, the volume of the second support chamber decreases, and vice versa. Advantageously, four support chambers can be provided in the swivel motor, which are each separated alternately by two rotor blades and two stator blades. The rotor has an eccentric bore, which represents the eccentric and serves as a receptacle for a piston pin. The stator can be used with the rotor disposed therein in the Pleuelkörper and be arranged against rotation in the Pleuelkörper. The stator may further comprise two outer circumferential grooves, each having two inlet bores to the support chambers and ensure the connection between the support chambers and the inlet and outlet lines to a hydraulic supply port. The rotor is rotatably mounted in the stator. The introduction of a torque on the rotor can be done so conveniently via the piston pin, which is arranged in the eccentric bore of the rotor. By introducing the torque via the connecting rod and the lever to the rotor, the rotor can be adjusted via external mass forces and gas forces, thus changing the effective connecting rod length. By the hydraulic oil in the support chambers of the slewing motor, the torque can be supported.

According to an advantageous embodiment of the eccentric can be arranged in the rotor of the rotary motor and actuated by the rotor. The eccentric may conveniently be formed as an eccentrically arranged bore in the rotor, so that upon rotation of the rotor about its axis, the eccentric bore is rotated and arranged in the bore receptacle for the at least one lever in this way is eccentrically moved about the axis of the rotor ,

Due to the feasibility of larger swivel angle of the rotor of the swing motor compared to conventional conrod designs for variable compression can be chosen for the same adjustment length of the connecting rod a small eccentricity in the rotor, thereby keeping the maximum occurring pressures in the support chambers low. The swivel angle can be determined by the eccentricity of the bolt in the eccentric of the rotor. The large number of degrees of freedom, such as swivel angle, eccentricity, rotor diameter, number of vanes, to adapt the connecting rod to the internal combustion engine allows more detailed individual adjustments compared to conventional systems. By using the swivel motor for the eccentric adjusting device support piston and eccentric lever can be avoided in the connecting rod, since the support chambers are arranged in the pivot motor as a separate unit. The levers for adjusting the connecting rod are moved substantially in the longitudinal direction of the connecting rod, so that the entire connecting rod occupies a very compact space.

Another conceivable variant for the connecting rod is to replace the swivel motor system by an eccentric and intercept the eccentric torque via a further pair of levers in a linear movement. The linear movement allows the use of a double acting support piston or two separate support pistons. The necessary piston guide can be accommodated in the connecting rod body. The advantage lies in the additional use of an eccentric, which conducts most of the load in the Pleuelkörper and only supports the adjusting torque of the eccentric via a hydraulic fluid column. This results in much lower pressures in the support chambers.

According to an advantageous embodiment, at least one hydraulic fluid line for supplying hydraulic fluid into the first support chamber of the swing motor and at least one hydraulic fluid line for supplying hydraulic fluid into the second support chamber of the swing motor may be provided in the connecting rod body. The hydraulic fluid lines can be arranged space-saving in the connecting rod body, so as to guide the hydraulic fluid between the switching valve and the support chambers of the slewing motor. As a result, the rotor can be advantageously controlled in order to support the mass forces and gas forces which act on the eccentric adjusting device and thus to carry out the length adjustment of the connecting rod. Due to the low required number of hydraulic fluid lines can make a production of the connecting rod low.

According to an advantageous embodiment, the at least one rotor blade can be fastened to the rotor. The rotor can comprise several individual parts. For example, in a built rotor, the rotor blades may be screwed or pressed. Such a rotor can be manufactured inexpensively. It is also conceivable to provide the stator as a built stator with several individual parts. According to an advantageous embodiment, the first and / or the second support chamber may be sealed against each other by at least one sealing strip arranged on a running surface of the rotor and / or a running surface of the stator. In the running surfaces of the rotor blades arranged sealing strips seal the support chambers from each other. The sealing strips can also be biased by spring element. In the stator sealing strips are also arranged, which ensure a further sealing of the support chambers against each other in a component-related relative movement of the rotor.

According to an advantageous embodiment, the first and / or the second support chamber may be sealed against an environment by at least one sealing element arranged at least partially on an outer circumference of the rotor and / or an inner circumference of the stator. The sealing of the support chambers of the slewing motor against each other and against the environment is advantageously carried out via an annular seal, which is made possible by the structural design of the stator and rotor, which are inserted into one another via a round outer contour. The total length of the rotor is favorably greater than the length of the centrally arranged rotor blades in order to realize a sealing distance for the swivel motor. In order to produce an additional sealing effect, an annular sealing element, for example in the form of piston rings, is placed in each of the outwardly extending sealing sections. In order to achieve optimum sealing of the support chambers, in the case of piston rings, spherical sealing surfaces and an overlapping annular joint are advantageous to the outside. In this case, a contact force on the spherical outer shape of the prestressed piston rings is exerted on the stator. An additional sealing contact force can be exerted both axially and radially on the piston ring via the hydraulic pressure. In principle, the use of different types of piston rings and other annular sealing elements is possible.

According to an advantageous embodiment, the stator may have on an outer circumference at least two circumferential grooves for supplying the first and the second support chamber with hydraulic fluid. The stator may thus have at least two outer circumferential grooves, each having two inlet bores to the support chambers and ensure the connection between the support chambers and the inlet and outlet lines to a hydraulic supply port. In this way, the swivel motor can be conveniently supplied with hydraulic fluid. According to an advantageous embodiment, at least one check valve can be provided in the hydraulic fluid line between the first support chamber and a supply connection and / or at least one check valve in the hydraulic fluid line between the second support chamber and the supply connection. In this way it can be prevented that hydraulic fluid from the support chambers unintentionally flows into the supply port and lose the support chambers to hydraulic pressure.

According to an advantageous embodiment, the switching valve and the check valves may be arranged in the connecting rod cover. A particularly space-saving arrangement provides for the inclusion of reversing valve and check valves in the connecting rod cover. Hydraulic tests of the components are so easy to perform on the connecting rod cover. In addition, defective components can be easily replaced by replacing the connecting rod cap. In addition, the production of the connecting rod body is advantageously simplified in this way and there is no Ölversorgungsnut in the upper part of the large Pleuellagerauges necessary, whereby the bearing shell is less loaded due to the larger area.

According to an advantageous embodiment, a groove for supplying the changeover valve with hydraulic fluid from the supply connection may be provided on a circumference of a Hublagerauges arranged at least partially in the connecting rod cover at least in the region of the connecting rod cover. The groove can ensure a reliable supply of the changeover valve and thus the swivel motor with hydraulic fluid. The fact that the groove is arranged only at the lower part of the circumference of the lifting eye, the bearing capacity of the bearing in the Bublagerauge is affected as little as possible.

According to an advantageous embodiment, at least one stop for limiting an axial movement of the connecting rod may be provided in the Pleuelkörper. The use of defined stops in both directions of the adjustment of the connecting rod prevents accidental striking of the rotor blades on the stator and thus provides a protective mechanism for the swing motor system. The use of the defined attacks also allows relief of the eccentric adjusting device at maximum loads occurring and thus prevents the occurrence of high pressure surges in the support chambers, since the forces can be absorbed by the connecting rod body. In this way, an undesirable compression due to the compressibility of the hydraulic fluid can be avoided. According to an advantageous embodiment, the eccentric adjusting device can be driven by inertial forces and gas forces of an internal combustion engine. Mass forces and gas forces are used for the actual adjustment of the eccentric adjusting device to a change in the effective connecting rod length. In this way, the adjustment can be conveniently achieved with the least possible expenditure of energy. About the eccentric adjusting device, which may preferably have the swivel motor, the inertial forces and gas forces are supported in order to achieve a defined mode of operation with a specific connecting rod length. In addition, the higher mass of the eccentric adjusting device allows easier adjustment at lower speeds and a larger pivoting range.

According to an advantageous embodiment, the lever may be connected to the connecting rod via at least one rotatable pin and / or with the eccentric via at least one rotatable pin. The introduction of a torque on the rotor can be done so conveniently over the bolt, which is arranged in the eccentric bore of the rotor. By introducing the torque onto the rotor, the rotor can be adjusted via external mass forces and gas forces, thus changing the effective connecting rod length. By hydraulic pressure in the support chambers of the swing motor, the torque can be supported.

Furthermore, an internal combustion engine with variable compression is proposed with a connecting rod according to the invention.

Brief description of the drawings

Further advantages emerge from the following description of the drawing. In the drawings, an embodiment of the invention is shown schematically. The drawings, the description and the claims contain numerous features in combination. The person skilled in the art will expediently also consider the features individually and combine them into meaningful further combinations. They show by way of example:

Figure 1 shows a connecting rod according to the invention in a slightly tilted plan view and partially longitudinal sectional view in a position for low compression.

Figure 2 shows the connecting rod of Figure 1 in a slightly tilted plan view and partially longitudinally sectioned view in a position for high compression.

3 shows the connecting rod from FIG. 1 in a side view for defining sectional planes;

4 to 6 different sections of the connecting rod in a position for low compression;

4 shows a first longitudinal section through the connecting rod of Figure 1 in the position for low compression along the line A-A in Fig. 3 ..;

5 shows a second longitudinal section through the connecting rod of Figure 1 in the position for low compression along the line C-C in Fig. 3 ..;

FIG. 6 shows a third longitudinal section through the connecting rod of FIG. 1 in a position for low compression along the line D-D in FIG. 3; FIG.

Figure 7 is a detail view in longitudinal section through the connecting rod cover with details of the changeover valve and a check valve in the low compression position.

Fig. 8 is a detail view in a further longitudinal section through the connecting rod cover

 Details of the changeover valve and another check valve in the low compression position;

9 shows a longitudinal section through the pivot motor of the connecting rod arranged in the connecting rod body in the position for low compression;

10 to 12 different sections of the connecting rod in a position for high compression; FIG. 10 shows a first longitudinal section through the connecting rod from FIG. 1 in the position for high compression along the line AA in FIG. 3; FIG.

1 1 shows a second longitudinal section through the connecting rod of Figure 1 in the position for high compression along the line C-C in Fig. 3.

Fig. 12 is a third longitudinal section through the connecting rod of Fig. 1 in the position for high

 Compression along the line D-D in Fig. 3;

Fig. 13 is a detail view in longitudinal section through the connecting rod cover with details of the changeover valve and a check valve in the position for high compression;

Fig. 14 is a detail view in a further longitudinal section through the connecting rod cover with

 Details of the changeover valve and another check valve in the high compression position;

15 shows a longitudinal section through the pivot motor of the connecting rod arranged in the connecting rod body in the position for high compression; and

16 is an exploded view of the connecting rod of FIG. 1.

Embodiments of the invention

 In the figures, the same or similar components are numbered with the same reference numerals. The figures are merely examples and are not intended to be limiting.

FIG. 1 shows a connecting rod 10 according to the invention in plan view and partially in longitudinal section in a position for low compression. The connecting rod 10 comprises a connecting rod body 12, a connecting rod 16 displaceably guided in a longitudinal direction L of the connecting rod body 12 with a connecting rod eye 18, a connecting rod cover 14, and an eccentric adjusting device 20 for adjusting an effective connecting rod length 60. The connecting rod is partially in the interior of the connecting rod body 12 guided in the longitudinal direction L. The connecting rod cover 14 is screwed with the connecting rod 22 to the connecting rod 12 and forms together with this the Hublagerauge 38 as a large Connecting rod. The connecting rod body 12 is cut longitudinally in the illustration in FIG. 1 in the region of the lifting bearing eye 38. By moving the connecting rod 16 in the connecting rod body 12, the effective connecting rod length 60 (see FIG. 4), which is defined as the distance of the central axis of the lifting bearing eye 38 from the central axis of the small connecting rod eye 18 in the connecting rod 16, can be changed.

The eccentric adjusting device 20 is arranged in the connecting rod body 12 and has an eccentric 21 cooperating with the levers 24, 25. Lever 25 is not visible in the illustration in Figure 1, since it is arranged on the back of the connecting rod body 12. The eccentric adjusting device 20 can be driven by inertial forces and gas forces of an internal combustion engine, wherein an adjustment of the eccentric adjusting device 20 is hydraulically adjustable by means of a switching valve 32 by a position of the eccentric adjusting device 20 can be locked by the hydraulic fluid. The eccentric 21 itself is pivotable about its axis of rotation. The levers 24, 25 are pivotally connected to the connecting rod 16 via the bolt 31, so that via an adjustment of the eccentric 21, the connecting rod 16 are moved in their leadership in Pleuelkörper 12 and thus the effective connecting rod 60 can be changed.

In the connecting rod cover 14, the switching valve 32 and two check valves 64, 66 are arranged for controlling a hydraulic fluid flow.

In the illustration in Figure 1 in the position for low compression, the connecting rod 16 is maximally inserted into the connecting rod body 12, so that the connecting rod 16 is in the lower position and the effective connecting rod length 60 is minimal.

Figure 2 shows the connecting rod 10 of Figure 1 in plan view and partially longitudinally sectioned view in a position for high compression. In this position, the connecting rod 16 is maximally pushed out of the connecting rod body 12, so that the connecting rod 16 is in the upper position and the effective connecting rod length 60 is maximum.

In FIG. 3, sectional views of the sections shown in the following figures are defined in side view of the connecting rod 10 from FIG.

FIGS. 4 to 6 show different sections of the connecting rod 10 in a position for low compression. FIG. 4 shows a first longitudinal section through the connecting rod 10 from FIG. 1 in the position for low compression along the line AA in FIG. 3. The eccentric adjusting device 20 of the illustrated embodiment of a connecting rod 10 according to the invention comprises a pivoting motor 26, which has one in a stator 28 mounted rotor 27 has. Details about the pivoting motor 26 can be seen in FIG. The eccentric 21 is disposed in the rotor 27 of the swing motor 26 and actuated by the rotor 27.

In the connecting rod body 12, a hydraulic fluid passage 70 for supplying hydraulic fluid into the first support chamber 52 of the swing motor 26 and a hydraulic fluid passage 72 for supplying hydraulic fluid into the second support chamber 54 of the swing motor 26 are provided. The hydraulic fluid lines 70, 72 can be seen partially cut in FIGS. 5 and 6. In the hydraulic fluid passage 70 between the first support chamber 52 and a supply port, a check valve 64 is provided and in the hydraulic fluid passage 72 between the second support chamber 54 and the supply port, a check valve 66 is provided. The switching valve 32 and the check valves 64, 66 are arranged in the connecting rod cover 14 in the area between the connecting rod 22. On a circumference of the partially arranged in the connecting rod cap 14 Hublagerauges 38 a groove 68 is provided for supplying the switching valve 32 with hydraulic fluid from the supply port in the region of the connecting rod cover 14.

The connecting rod is connected via the rotatable pin 31 and the levers 24, 25 arranged thereon to the eccentric 21 via a further rotatable pin 30. In Figure 4, both bolts are shown in the lower position for low compression. In the Pleuelkörper 12 a designated lower stop 40 for limiting an axial movement of the connecting rod 16 is provided.

In Figure 5 and Figure 6 are further longitudinal sections through the connecting rod 10 of Figure 1 in the position for low compression along the line C-C, and along the line D-D shown in Figure 3. In the two sections, the hydraulic fluid lines 70 and 72 are partially cut to recognize.

FIG. 7 shows a detailed view in a longitudinal section through the connecting rod cover 14 with details of the reversing valve 32 and of a check valve 64 in the position for low Compression, while in Figure 8 is a detail view in a further longitudinal section through the connecting rod cover 14 with details of the changeover valve 32 and the other check valve 66 in the position for low compression is shown.

The switching valve 32 is shown with the slide 78, which is displaceable perpendicular to the plane and can be held in a position by means of a latchable, not shown, latching element. The locking element is pressed by the compression spring 44, which is shown partially cut against locking positions in the slide. In the slide flow holes are arranged, of which a flow hole 76 can be seen in Figure 8, which serve to distribute the hydraulic fluid to different hydraulic fluid lines.

In the low-compression position, the spool 78 is such that the hydraulic fluid passage 72, which is the so-called gas power passage, is directly connected to the supply port of the hydraulic fluid and the hydraulic fluid passage 70, which is the so-called mass passage, is closed. These hydraulic fluid lines 70, 72 are provided with a throttled bore, for example. As shown in FIG. 8, the flow of hydraulic fluid through the flow bore 76 is directed into the hydraulic fluid line 72. The two non-return valves 64, 66, which respectively connect the supply connection via a hydraulic fluid line 74 to the hydraulic fluid lines 70, 72, are seated obliquely to the through-bores 76, which can be designed as an inlet bore and drainage bore. The check valves 64, 66 are designed so that in a valve body 48, a ball 46 are pressed by means of a compression spring 44 in a valve seat 50. The check valves 64, 66 are switched so that hydraulic fluid can flow only from the supply port into the respective support chambers 52, 54 of the swing motor 26, but can not flow in the reverse direction.

FIG. 9 shows a longitudinal section through the pivot motor 26 of the connecting rod 10 arranged in the connecting rod body 12 in the position for low compression. The rotor 27 of the swivel motor 26 stands in such a way that the eccentric 21 with its bolt 30 in the lower position, so that the rotor blades 56 abut the stator vanes 58. Between the rotor vanes 56 of the rotor 27 and the stator vanes 58 of the stator 28, two first support chambers 52 and two second support chambers 54 are formed, wherein a volume of the first support chamber 52 and a volume of the second support chamber 54 by a Adjustment of rotor 27 against stator 28 complementary to each other are changeable. In the illustrated position of the rotor 27, the volume of the first support chambers 52 is maximally formed, while the volume of the second support chambers 54 is minimal, since the rotor vanes 56 abut on one side of the stator vanes 58. In the illustrated embodiment, the rotor 27 is formed integrally with the rotor vanes 56. Alternatively, the rotor blades 56 could be provided as screwed.

The first and the second support chamber 52, 54 are sealed by a arranged on a running surface 62 of the rotor 27 and a running surface 63 of the stator 28 sealing strip 36, 37 against each other. In addition, the first and the second support chamber 52, 54 are sealed by two arranged on an outer periphery 88 of the rotor 27 sealing elements 34 against an environment. Alternatively, it would also be possible to arrange the sealing elements 34 on an inner circumference 90 of the stator 28. The sealing elements 34 are not visible in the illustrated section.

The stator 28 has on an outer circumference 92 two circumferential grooves 84, 86 for supplying the first and the second support chamber 52, 54 with hydraulic fluid. The grooves 84, 86 are supplied with the hydraulic fluid from the hydraulic fluid lines 70, 72 and direct the hydraulic fluid into the first support chambers 52 via the hydraulic fluid lines 71 arranged in the stator vanes 58.

Figures 10 to 12 show various sections of the connecting rod 10 in a high compression position. In FIG. 10, in a first longitudinal section along the line AA in FIG. 3, the connecting rod 10 from FIG. 1 is shown in the position for high compression, while FIGS. 11 and 12 show the sections along the line CC in FIG Line DD in Figure 3 show. The eccentric 21 is pivoted to the rotor 27 of the swing motor 26 in its upper position, so that the connecting rod 16 is pushed into the upper position. The connecting rod 16 rests against a stop 42, not shown, at the upper end of the connecting rod body 12. The use of defined stops 40, 42 prevents unintentional striking of the rotor vanes 56 to the stator vanes 58 and thus represents a protective mechanism for the swivel motor system, since the swivel motor system is relieved by the power flow redirection. In Figures 1 1 and 12, the truncated hydraulic fluid lines 70, 72 can be seen. FIG. 13 shows a detailed view in a longitudinal section through the connecting rod cap 14 with details of the reversing valve 32 and the check valve 64 in the high compression position, while FIG. 14 shows a detailed view in a further longitudinal section through the connecting rod cap 14 with details of the reversing valve 32 and other check valve 66 in the high compression position shows. In the high compression position, the spool 78 of the switching valve 32 is so that the hydraulic fluid passage 70, which is the mass flow passage, is directly connected to the supply port of the hydraulic fluid and the hydraulic fluid passage 72, which is the gas power passage, is closed.

FIG. 15 shows a longitudinal section through the pivot motor 26 of the connecting rod 10 arranged in the connecting rod body 12 in the position for high compression. As can be seen, the rotor 27 is such that the pin 30 in the eccentric 21 is in its upper position. As a result, the connecting rod 16 is also pushed into the upper position via the levers 24, 25.

In Figure 16 is an exploded view of the connecting rod 10 of Figure 1 can be seen. The connecting rod body 12 has in the receptacle for the pivot motor 26 of the stator 28 and rotor 27 has a bore which is the opening of the hydraulic fluid line 72 through which the grooves 84, 86 of the stator 28 can be supplied with hydraulic fluid, which then further into the Support chambers 52, 54 is passed. Rotor 27 and stator 28 have the sealing strips 36, and 37 in their running surfaces 62, 63, while the rotor 27 via the arranged in the grooves 80, 82 sealing elements 34, for example in the form of O-rings, the support chambers 52, 54th seals against the environment. Bolts 30 in the eccentric 21 of the rotor 27 and in the connecting rod 16 are connected to each other via the levers 24, 25 so that a rotation of the eccentric 21 results in a displacement of the connecting rod 16 guided in the connecting rod 12 with the connecting rod 18 and vice versa. The connecting rod cap 14, in which the reversing valve 32 and the two check valves 64, 66 are arranged, is screwed to the Pleuelkörper 12 and forms with this the Hublagerauge 38. In the Hublagerauge 38 is in the region of the connecting rod cover 14, a groove 68 for supplying the changeover valve 32 arranged with hydraulic fluid from the supply port. The check valves 64, 66 are shown with valve body 48, ball 46 and compression spring 44.

The stator 28 is arranged against rotation in the connecting rod body 12 and preferably welded thereto. A stator cover is in the embodiment shown in one piece with the Connecting rod body 12 is provided. Likewise, it is conceivable to attach a separate stator cover to the connecting rod body 12.

Claims

claims 1 . Connecting rod (10) for a variable compression internal combustion engine, comprising  a connecting rod body (12),  a connecting rod (16) displaceably guided in a longitudinal direction (L) of the connecting-rod body (12) with a connecting-rod eye (18),  a connecting rod cover (14),  an eccentric adjusting device (20) for adjusting an effective connecting rod length (60),  wherein the eccentric adjusting device (20) in the Pleuelkörper (12) is arranged and with at least one lever (24, 25) cooperating eccentric (21) and a displacement of the eccentric adjusting device (20) by means of a switching valve (32) adjustable is, wherein the eccentric (21) is pivotable about its axis of rotation, and wherein the at least one lever (24, 25) with the connecting rod (16) is pivotally connected. 2. connecting rod according to claim 1, wherein the eccentric adjusting device (20) comprises a pivot motor (26) having a in a stator (28) mounted rotor (27), wherein between at least one rotor blade (56) of the rotor (27). and at least one stator vane (58) of the stator (28) is formed with at least a first support chamber (52) and at least a second support chamber (54), wherein a volume of the first support chamber (52) and a volume of the second support chamber (54) Adjustment of the rotor (27) against the stator (28) complementary to one another are variable. 3. Connecting rod according to claim 2, wherein the eccentric (21) in the rotor (27) of the pivot motor (26) and arranged by the rotor (27) is actuated. 4. connecting rod according to claim 2 or 3, wherein in the connecting rod body (12) at least one hydraulic fluid line (70) for supplying hydraulic fluid into the first support chamber (52) of the pivot motor (26) and at least one hydraulic fluid line (72) for supplying hydraulic fluid in the second support chamber (54) of the swing motor (26) are provided. 5. Connecting rod according to one of claims 2 to 4, wherein the at least one rotor blade (56) to the rotor (27) is fastened. 6. Connecting rod according to one of claims 2 to 5, wherein the first and / or the second support chamber (52, 54) by at least one on a running surface (62) of the rotor (27) and / or a running surface (63) of the stator (28) arranged sealing strip (36, 37) are sealed against each other. 7. Connecting rod according to one of claims 2 to 6, wherein the first and / or the second support chamber (52, 54) by at least one at least partially on an outer circumference (88) of the rotor (27) and / or an inner circumference (90) of the stator (28) arranged sealing element (34) are sealed against an environment. 8. Connecting rod according to one of claims 2 to 7, wherein the stator (28) on an outer circumference (92) has at least two circumferential grooves (84, 86) for supplying the first and the second support chamber (52, 54) with hydraulic fluid. 9. Connecting rod according to one of claims 2 to 8, wherein in the hydraulic fluid line (70) between the first support chamber (52) and a supply port at least one check valve (64) and / or in the hydraulic fluid line (72) between the second support chamber (54). and at least one check valve (66) is provided in the supply connection. 10. connecting rod according to claim 9, wherein the switching valve (32) and the check valves (64, 66) in the connecting rod cover (14) are arranged. 1 1. Connecting rod according to one of the preceding claims, wherein on a circumference of a at least partially in the connecting rod cover (14) arranged Hublagerauges (38) at least in the region of the connecting rod cover (14) has a groove (68) for supplying the changeover valve (32) with hydraulic fluid from the supply port is provided. 12. Connecting rod according to one of the preceding claims, wherein in the Pleuelkörper (12) at least one stop (40, 42) for limiting an axial movement of the connecting rod (16) is provided. 13. Connecting rod according to one of the preceding claims, wherein the eccentric adjusting device (20) via mass forces and gas forces of an internal combustion engine can be driven. 14. Connecting rod according to one of the preceding claims, wherein the lever (24, 25) with the connecting rod (16) via at least one rotatable pin (31) and / or with the eccentric (21) via at least one rotatable pin (30) is connected , 15. Connecting rod according to claim 1, wherein the eccentric adjusting device (20) has a further eccentric, wherein an eccentric moment is intercepted via a further lever pair in a linear movement. 16. Internal combustion engine with variable compression with a connecting rod (1) according to one of the preceding claims.