WO2020113252A1

WO2020113252A1 - System and method for adjusting an effective length of a connecting rod by supplying lubricant

Info

Publication number: WO2020113252A1
Application number: PCT/AT2019/060413
Authority: WO
Inventors: Martin Rath
Original assignee: Avl List Gmbh
Priority date: 2018-12-04
Filing date: 2019-12-04
Publication date: 2020-06-11
Also published as: CN113383153A; DE112019006024A5; AT521887A1; AT521887B1

Abstract

The invention relates to a system (100) and a method (110) for adjusting an effective length of a length-adjustable connecting rod (1) for an internal combustion engine, as well as an internal combustion engine comprising a length-adjustable connecting rod (1) and a system (100) of this type. The connecting rod (1) has at least one first connecting part (4) and a second connecting part (5), which can be shifted in the direction of a longitudinal axis (1a) of the connecting parts (4, 5) and/or inside one another by means of a length adjustment device (16). Also provided is a lubricant supply assembly (101) via which at least one crankshaft bearing (K) and/or crankpin bearing (3c) of the internal combustion engine can be supplied with a lubricant, as well as a hydraulic supply line (13) via which the length adjustment device (16) can be supplied with the lubricant being used as hydraulic medium. A supply device (37) is also provided, which can be fluidically connected on the output side with both the lubricant supply assembly (101) and the hydraulic supply line (13), and which is designed to withdraw the lubricant out of a lubricant reservoir (38) on the input side and to selectively direct a first portion of the withdrawn lubricant into the lubricant supply assembly (101) to lubricate the at least one crankshaft bearing (K) and/or crankpin bearing (3c) and direct a second portion of the lubricant into the hydraulic supply line (13) to shift the two connecting parts (4, 5) relative to and/or inside one another.

Description

System and method for adjusting an effective length of a

Connecting rod by means of lubricant supply

The present invention relates to a system and a method for setting an effective length of a length-adjustable connecting rod for an internal combustion engine, in particular a reciprocating piston engine, and an internal combustion engine with a length-adjustable connecting rod and such a system.

In order to optimize internal combustion engines with regard to emissions and consumption, variants with a variable compression ratio are increasingly being examined. By changing the compression of an internal combustion engine, full load can be operated with a lower compression ratio, partial load and starting with an increased ratio. Consumption is improved in the part-load range, the compression pressure is increased with the increased compression ratio at the start and the peak pressure is reduced with a reduced ratio at high power, and knocking is prevented.

In this context, document AT 511 803 B1, for example, discloses a connecting rod that can be displaced in length for an internal combustion engine with two connecting rod parts that can be telescopically pushed into one another, a high-pressure chamber spanning between the first and the second connecting rod parts, into which a first oil channel opens.

It is an object of the invention to provide an improved system and method for setting an effective length of a length-adjustable connecting rod and a corresponding internal combustion engine. It is a particular object of the invention to simplify the hydraulic actuation of a length adjustment device.

This object is achieved by a system and a method for setting an effective length of a length-adjustable connecting rod for an internal combustion engine, in particular a reciprocating piston engine, and an internal combustion engine with a length-adjustable connecting rod and such a system. A first aspect of the invention relates to a system for setting an effective length of a length-adjustable connecting rod for an internal combustion engine, in particular a reciprocating piston engine, the connecting rod having at least a first connecting rod part and a second connecting rod part. The two connecting rod parts can preferably be displaced in and out of one another, in particular telescopically, by means of a length adjustment device, in particular hydraulically actuated, in the direction of a longitudinal axis of the connecting rod parts. In this case, a lubricant supply arrangement is preferably provided, via which at least one crankshaft bearing and / or crankpin bearing of the internal combustion engine can be supplied with a lubricant, and a hydraulic feed line, via which the length adjustment device can be supplied with the lubricant used as hydraulic medium. In addition, a supply device can be provided, which can be flow-connected on the output side both to the lubricant supply arrangement and to the hydraulic supply line. The supply device is preferably set up to remove the lubricant on the input side from a lubricant reservoir and to selectively guide a first portion of the removed lubricant for lubricating the at least one crankshaft bearing and / or crankpin bearing into the lubricant supply arrangement and a second portion of the lubricant into the hydraulic feed line for shifting the to lead both connecting rod parts and / or into each other. The lubricant can be engine oil, for example.

Preferably, the second connecting rod part, which in particular has a large connecting rod eye for connection to a crankshaft, and the first connecting rod part, which in particular has a small connecting rod eye for connection to a piston, thereby form a first hydraulic chamber which is in a first, in particular long, switching position of the Connecting rod is maximally (ie completely) filled with a hydraulic medium, and a second hydraulic chamber which is maximally (ie completely) filled with the hydraulic medium in a second, in particular short, switching position. The first hydraulic chamber and the second hydraulic chamber can preferably be selectively loaded with the hydraulic medium via the hydraulic feed line. The supply device is in particular set up to feed the hydraulic medium into the hydraulic feed line Transfer the connecting rod from the first switching position to the second switching position and / or to maintain the second switching position.

An effective length of a length-adjustable connecting rod in the sense of the invention is in particular the distance between an axis of rotational symmetry of a small connecting rod eye for connection to a piston and an axis of rotation symmetry of a large connecting rod eye for connection to a crankshaft.

A longitudinal axis of the connecting rod parts in the sense of the invention is in particular a longitudinal axis of the length-adjustable connecting rod.

The invention is based in particular on the approach of dispensing lubricants from a general lubricant reservoir, e.g. by means of a pump, and then, in particular selectively, to a lubricating supply arrangement for lubricating at least one crankshaft and / or crankpin bearing and / or into a hydraulic supply line for displacing two connecting rod parts of a length-adjustable connecting rod. For this purpose, a supply device is provided, which is preferably set up to transfer the removed lubricant between the lubricant supply arrangement, e.g. a main oil gallery, and the hydraulic supply line. The supply device can e.g. be designed as a flow divider or have such a flow divider and / or be set up to regulate the amount of the lubricant fed into the lubricant supply arrangement and into the hydraulic feed line, preferably individually or independently of one another. The supply device can in particular be set up to regulate, in particular to increase or decrease, the flow of the lubricant in or into the hydraulic feed line in such a way that a pressure increase or pressure drop necessary for changing between the first switching position and the second switching position is realized .

The invention thus makes it possible to integrate a length adjustment device which can be actuated hydraulically by means of lubricating oil into the lubricant supply of an internal combustion engine. The fact that the quantity of lubricant which has been removed, for example pumped out of the lubricant reservoir, is divided between the lubricant supply arrangement and the hydraulic feed line the number of components required to supply the length adjustment device with lubricant used as hydraulic medium can be advantageously reduced. The supply device makes it possible, in particular, to provide only a single pump, for example the conventional motor oil pump, for pumping the lubricant from the lubricant reservoir both into the lubricant supply arrangement and into the hydraulic feed line. An (electrical) auxiliary pump, which is provided in conventional systems for regulating the pressure in the hydraulic feed line for actuating the length adjustment device, can thus be dispensed with. This not only reduces the space requirement of the system, but also increases the efficiency of the internal combustion engine equipped with the system, since the friction generated by the additional pump is eliminated. Last but not least, this can also reduce the costs of such a system.

Overall, the invention allows an improved system and method for setting the effective length of a length-adjustable connecting rod as well as a corresponding internal combustion engine to be specified. In particular, the invention can improve, in particular simplify, an integration of a length adjustment device, in particular a hydraulically actuated length adjustment device, into the lubricant supply of an internal combustion engine.

Preferred embodiments of the invention and their developments are described below, each of which, as far as this is not expressly excluded, can be combined with one another as desired and with the aspects of the invention described below.

In a preferred embodiment, the supply device has a pump which is set up to remove the lubricant from the lubricant reservoir and, in particular the second portion of the lubricant, with an outlet pressure, in particular for displacing the two rod parts towards and / or into one another act upon. In this case, the pump can in particular be set up to increase or decrease the delivery quantity of the lubricant from the lubricant reservoir for moving the two rod parts towards and / or into one another. In other words, the pump is preferably set up to regulate the delivery rate for actuating the length adjustment device. This allows the to operate the Length adjustment device necessary (output) pressure, in particular the pressure level in the hydraulic supply line, can be set in a simple manner.

The pump, e.g. a conventional motor oil pump, as is usually provided in vehicles with an internal combustion engine, can preferably be controlled, for example by means of an engine control unit (ECU), in order to set the pressure level required to actuate the length adjustment device.

In a further preferred embodiment, the pump has a first pump arrangement, which can be flow-connected, in particular on the output side, to the lubricant supply arrangement, a second pump arrangement, which can be flow-connected, in particular on the output side, to the hydraulic feed line, and a common drive for driving the first and second pump arrangement . Each of the two pump arrangements can preferably be controlled individually, for example by means of an engine control unit. In this way, two outputs of the supply device which can be regulated separately with respect to the proportions of the lubricant fed into the lubricant supply arrangement or hydraulic supply line can be formed, e.g. without additional space for another drive. The lubricant removed from the lubricant reservoir, in particular its pressure in the lubricant supply arrangement or hydraulic feed line, can thereby be metered particularly precisely and independently of the division into the lubricant supply arrangement or hydraulic feed line.

The first and second pump arrangements can, for example, have rotors arranged eccentrically to a stator of a rotary vane pump or vane pump. The rotary vane pump or vane pump is preferably designed in such a way that the eccentricity of the rotor of the first pump arrangement and the rotor of the second pump arrangement can be set separately, so that two different volume flows can be realized on the output sides of the two pump arrangements.

In a further preferred embodiment, the supply device has a divider arrangement, in particular arranged downstream of the pump, which is set up to control the flow of the outlet pressure To regulate and / or regulate lubricant in the lubricant supply arrangement and / or the flow of the hydraulic medium into the hydraulic feed line for displacing the two rod parts, in particular actively, for example depending on the outlet pressure. The divider arrangement can in particular set the ratio between the flow into the lubricant supply arrangement and the flow into the hydraulic feed line. In other words, the divider arrangement can divide the lubricant removed from the lubricant reservoir, for example pumped by means of the pump and charged with the outlet pressure, into the first part and the second part, for example in order to regulate the pressure levels in the lubricant supply arrangement or the hydraulic feed line. The division of the lubricant between the lubricant supply arrangement and the hydraulic feed line can thus take place particularly efficiently.

A flow of the lubricant in the sense of the invention is in particular an amount of the lubricant flowing per unit of time through a section of the lubricant supply arrangement or hydraulic feed line. An increase in the flow into the hydraulic supply line preferably corresponds to an increase in the outlet pressure.

The divider arrangement can preferably be controlled, for example by an engine control unit, in order to regulate the flow of the lubricant, in particular into the lubricant supply arrangement and / or the hydraulic feed line.

The divider arrangement can, for example, be set up to control the flow of the lubricant into the lubricant supply arrangement in such a way that a sufficient amount of lubricant is provided in the crankshaft bearings and / or crankpin bearings. The divider arrangement can in particular ensure that the flow into the lubricant supply arrangement remains constant regardless of the outlet pressure.

Alternatively or additionally, the divider arrangement can be set up to control the flow of the lubricant into the hydraulic feed line in such a way that when the outlet pressure increases, a larger proportion of the lubricant into the hydraulic feed line and a smaller part when the outlet pressure decreases Proportion of the lubricant is fed into the hydraulic supply line. As a result, the length adjustment device can be operated reliably.

In a further preferred embodiment, the divider arrangement has a first flow valve assigned to the lubricant supply arrangement and a second flow valve assigned to the hydraulic feed line. The flow valves can be designed in particular as throttle valves, orifice valves and / or the like. As a result, the flow rate of the lubricant in the

Lubricant supply arrangement or hydraulic supply line can be reliably controlled. E.g. can in this way the pressure of the lubricant in the

Lubricant supply arrangement can be reduced to a desired or predetermined pressure level by throttling the outlet pressure by means of the first flow valve, while an increase in pressure is made possible in the hydraulic feed line, in particular by appropriate configuration of the second flow valve.

In a further preferred embodiment, the hydraulic feed line has at least one feed channel, wherein preferably at least one crankshaft bearing and at least one crankpin bearing are fluidly connected through the feed channel. The hydraulic feed line preferably has at least one feed channel, which runs in the crankshaft from the at least one crankshaft bearing to a crankpin bearing, where the length adjustment device can be actuated by means of the lubricant used as the hydraulic medium, which may be pressurized.

In a further preferred embodiment, the hydraulic feed line for supplying the length adjustment device with the at least one crankshaft bearing is connected to the flow. Lubrication of the at least one crankshaft bearing and / or the crankpin bearing via a feed on the at least one crankshaft bearing is particularly easy to achieve mechanically.

In a further preferred embodiment, both the hydraulic feed line and the lubricant supply arrangement are fluidly connected to the at least one crankshaft bearing, preferably via an inlet opening of the crankshaft bearing. The at least one crankshaft bearing preferably has an inlet opening through which the lubricant provided by the lubricant supply arrangement and hydraulic feed line enters the crankshaft bearing. The at least one crankshaft bearing is thus supplied with lubricant via two feeds, namely both via the lubricant supply arrangement and via the hydraulic feed line. An advantage of such an embodiment is that by introducing lubricant by means of a lubricant supply arrangement and hydraulic feed line to a lubrication point, namely the crankshaft bearing, a change in the pressure level of the lubricant can be effected in a particularly simple manner in order to actuate the length adjustment device.

The lubricant supply arrangement preferably has at least one non-return valve, which is set up, in particular arranged in such a way, to discharge the lubricant directed via the hydraulic feed line into the at least one crankshaft bearing into the

Prevent lubricant supply arrangement. A pressure drop in the hydraulic feed line or in the crank pin bearing, which makes reliable actuation of the length adjustment device impossible or at least difficult, can be avoided by the at least one check valve.

In a further preferred embodiment, the lubricant supply arrangement is fluidly connected to a first group of crankshaft bearings. The hydraulic feed line for loading the length adjustment device is preferably fluidly connected to a second group of crankshaft bearings, the first group not containing a crankshaft bearing of the second group and the supply device being set up to also supply the second group of crankshaft bearings via the lubricant supply arrangement in addition to the first group of crankshaft bearings lubricate the hydraulic supply line with the lubricant. This simplifies the construction of the lubricant supply arrangement, since oil supply lines to the second group of crankshaft bearings can be saved.

The supply device is preferably set up to feed a portion of the lubricant removed from the lubricant reservoir into the hydraulic feed line, regardless of the switching state of the connecting rod to ensure the lubrication of the second group of crankshaft bearings.

A second aspect of the invention relates to a method for adjusting an effective length of a length-adjustable connecting rod for a

Internal combustion engine, in particular reciprocating piston engine, wherein the connecting rod has at least a first connecting rod part and a second connecting rod part. The two connecting rod parts are preferably by means of a length adjustment device, in particular hydraulically actuated, in the direction of a longitudinal axis of the

Connecting rod parts, particularly telescopically, can be moved towards and / or into one another. Within the scope of the method, a lubricant is preferably removed from a lubricant reservoir by means of a supply device, the supply device on the output side having both

Lubricant supply arrangement, via which at least one crankshaft bearing and / or crankpin bearing of the internal combustion engine can be charged with a lubricant, and also with a hydraulic feed line, via which the

Length adjustment device can be loaded with the lubricant used as the hydraulic medium, is flow-connectable. A first part of the taken

Lubricant for lubricating the at least one crankshaft bearing and / or crankpin bearing can be directed into the lubricant supply arrangement, and a second portion of the removed lubricant for moving the two connecting rod parts towards and / or into one another can be directed into the hydraulic feed line.

A third aspect of the invention relates to an internal combustion engine, in particular a reciprocating piston engine, having a length-adjustable connecting rod which has at least a first connecting rod part and a second connecting rod part, the two connecting rod parts being adjusted in the direction of a longitudinal axis of the connecting rod parts, in particular telescopically, by means of a, in particular hydraulically operated, length adjustment device. are movable towards and / or into one another, and a system according to the first aspect of the invention.

Those related to the first aspect of the invention and its advantageous

Features and advantages described design apply, at least where technical sensible, also for the second and third aspects of the invention and its advantageous embodiment and vice versa.

The invention is explained in more detail below on the basis of non-limiting exemplary embodiments which are illustrated in the figures. In it at least partially show schematically:

Fig. 1 shows a preferred embodiment of an adjustable length

Connecting rod in a longitudinal section;

2a shows a preferred exemplary embodiment of a length adjustment device for a length-adjustable connecting rod in a first switching position;

Fig. 2b, the length adjustment device from Fig. 2a in a second

Switch position;

Fig. 3 shows an inventive system according to a first preferred

Execution;

Fig. 4 shows an inventive system according to a second preferred

Execution; and

Fig. 5 shows a preferred embodiment of an inventive

Procedure.

Figure 1 shows a length-adjustable connecting rod 1 for a reciprocating piston engine, for example an internal combustion engine, with a small connecting rod eye 2 for a piston pin bearing (not shown) and a large connecting rod eye 3 for a crank pin bearing (not shown) of an internal combustion engine. The rotational symmetry axes of the small and large connecting rod eyes 2, 3 are designated 2a and 3a. The longitudinal axis of the connecting rod 1 is 1 a, a normal to the rotational symmetry axes 2a and 3a of the small and large connecting rod eyes 2, 3 and including the longitudinal axis 1 a of the connecting rod 1 longitudinal center plane - the oscillating plane - the connecting rod 1 is designated by e.

The connecting rod 1 has an upper first connecting rod part 4 with the small connecting rod eye 2 and a lower second connecting rod part 5 with the large connecting rod eye 3 on. The first connecting rod part 4 is adjustable relative to the second connecting rod part 5 between a first switching position corresponding to an extended position and a second switching position shown in FIG. 1 corresponding to an inserted position by an adjustment range AL in the direction of the longitudinal axis 1 a of the connecting rod 1. In the upper first connecting rod part 4 there is an essentially cylindrical piston element 6, for example with one through a

Allen screw formed fastening screw 7 attached.

The piston element 6 is guided in an axially displaceable manner in a guide cylinder 8 of the lower second connecting rod part 5 of the connecting rod 1, with a first end face 6a of the piston element 6 facing the large connecting rod eye 3 and the second connecting rod part 5 in at least one position of the two connecting rod parts 4, 5 first hydraulic chamber 9 is opened. The piston element 6 designed as a stepped piston has a second one facing the small connecting rod eye 2

End face 6b, which borders a second hydraulic chamber 10, the cylindrical outer surface of which is formed by the guide cylinder 8 of the second connecting rod part 5. A stepped piston is generally understood to mean a piston — in the present case a “double-acting piston” - with active surfaces of different sizes, one of the active surfaces (here: the active surface oriented against the second hydraulic chamber 10) being designed as an annular surface and the other active surface as a circular surface is. Different pressure ratios can be achieved due to the different effective areas.

The first and second end faces 6a, 6b form pressure application surfaces for a hydraulic medium which is directed into the hydraulic chambers 9, 10 and is under pressure, for example engine oil or another lubricant.

A first oil channel 11 opens into the first hydraulic chamber 9 and a second oil channel 12 into the second hydraulic chamber 10, via which lubricant can be supplied / removed.

The oil supply to the first and second oil channels 11, 12 takes place via the hydraulic feed line 13, which originates from the connecting rod bearing 3b of the large connecting rod eye 3 and thus with the crank pin bearing (not shown) is connected to the flow and via connecting channels 14, 15 connected to the hydraulic supply line 13.

To control the pressures in the first and second hydraulic chambers 9, 10, a length adjustment device 16 is provided in the connecting rod 1, specifically in the lower second connecting rod part 5, which has a first valve 17 in the flow path between the first connecting channel 14 and the first oil channel 11 a first valve chamber 18, in which a first valve body 20, which is biased by a first valve spring 19, is pressed against a first valve seat 21. The first oil channel 11 opens into the first valve chamber 18. Furthermore, the length adjustment device 16 has a second valve 22 with a second valve chamber 23, in which a second valve body 25, which is biased by a second valve spring 24, is pressed against a second valve seat 26, the second oil channel 12 opening into the second valve chamber 23. Furthermore, the length adjustment device 16 has a connecting device 27 between the first valve 17 and the second valve 22 with at least one connecting element 28, which in the exemplary embodiments is formed by a connecting rod 29 arranged normal to the longitudinal axis 1a, in particular in a longitudinal center plane e of the connecting rod 1. The connecting element 28 is fixedly connected to a control piston 31 which is displaceable in a control cylinder 30. The control piston 31, which is spring-loaded by a return spring 32, borders a control chamber 33, into which a control line 34 connected to the hydraulic supply line 13 or the connecting channel 15 opens. The valve bodies 20 and 25 and the connecting device 27 are separate components. As a result, the connecting device 27 is spaced apart from the second valve body 25 in at least one first displacement position of the connecting element 28 shown in FIG. 2a and from the first valve body 20 in a second displacement position shown in FIG. 2b.

The first and second valve bodies 20, 25 of the first and second valves 17, 22 are preferably formed by balls.

The flow connections between the first supply channel 14 and the first oil channel 11 or between the second supply channel 15 and the second oil channel 12 are established by the valve bodies 20, 25 of the first and second valves 17, 22 opened or closed. The control piston 31, for example made of plastic, is actuated by an output pressure in the hydraulic feed line 13, for example by the oil pressure of the internal combustion engine.

If the oil pressure - for example under light load - is kept under a defined response pressure (for example 1.8 bar), the control piston 31 remains in its second position shown in FIG. 2b because the spring force of the return spring 32 is greater than the force the end face of the control piston 31 as a result of the oil pressure in the control line 34. In this case, the connecting rod 29, which is fixedly connected to the control piston 31, for example by a press fit, holds the valve body 25 for the connection to the second hydraulic chamber 10 via the second Oil channel 12 opened, while the first valve body 20 of the first valve 17 remains closed for the connection to the first hydraulic chamber 9 by the first valve spring 19.

During the stroke movement, a mass force acts on the connecting rod 1 in the area of the top dead center of the piston (not shown further), which pulls the first connecting rod part together with the piston 6 - viewed in FIGS. 1, 2a and 2b - and thus the small eye upwards. Oil is sucked in via the actually closed first valve 21, in that the first valve body 20 is raised against the restoring force of the first valve spring 19 by the suction effect created in the first hydraulic chamber 9; the lower first hydraulic chamber 9 fills with oil via the first oil channel 11, while oil from the upper second hydraulic chamber 10 is pressed into the second oil channel 12. The connecting rod 1 is longer. The oil flow in the oil channels 11, 12 is shown by arrows in Figure 2b.

When the oil pressure rises to a higher level with a higher engine load, the return spring 32 of the control piston 31 is compressed, the control piston 31 moving up to a left stop of the control cylinder 30.

In this position, the connecting rod 29 presses on the first valve body 20 of the first valve 17, which connects the lower first hydraulic chamber 9 to the oil supply channel 13. This allows the oil from the first hydraulic chamber 9 into the hydraulic feed line 13 and thus further into the Flow back oil supply system. Since the connecting rod 29 is lifted off the second valve body 25 and the second valve body is thus pressed onto the second valve seat 26 by the restoring force of the second valve spring 24, the second valve 22 is closed; with each ignition, the piston 6 is pressed down and oil is drawn into the second hydraulic chamber 10 by the suction effect in the second hydraulic chamber 10 via the actually closed second valve 22 through the second valve body 25, which lifts against the force of the second valve spring 24, until the second hydraulic chamber 10 also coexists Oil is filled. The flow of the oil is indicated by arrows in Figure 2a. In this position, the connecting rod 1 is shorter.

When the oil pressure in the oil or lubricant system is reduced again, the return spring 32 of the control piston 31 expands (FIG. 2 b) and the control piston 31 moves — as viewed in FIG. 2 b — to the right, the second valve 22 for the second hydraulic chamber 10 being opened and the first valve 17 for the first hydraulic chamber 9 is closed. The first hydraulic chamber 9 inflates again in the manner described by the mass forces acting on the second connecting rod part and the piston element 6 at the top dead center of the piston, and the connecting rod 1 becomes longer again.

FIG. 3 shows a system 100 according to the invention in accordance with a first preferred embodiment. A lubricant supply arrangement 101 is set up to supply crankshaft bearings K of a crankshaft 50 with a lubricant, for example oil, for example engine oil. For this purpose, the lubricant supply arrangement 101 has a main oil line 102, from which oil supply lines 102 a branch off to the crankshaft bearings K. The crankshaft bearings K each have an inlet opening, through which the lubricant supplied by the lubricant supply arrangement 101 and / or the hydraulic feed line 13 enters the crankshaft bearing K for lubrication. Crankpin bearings 3c of crankshaft 50 are flow-connected to crankshaft bearings K via feed channels 104 which run in crankshaft 50 and are shown as a broken line, so that crankpin bearings 3c can also be supplied with the lubricant. There is one on each of the crankpin bearings 3c of the crankshaft 50 lubricated with the oil length-adjustable connecting rod (see Figure 1) pivoted by means of a large connecting rod eye.

As explained in detail in connection with FIG. 1, the, in particular effective, length of the length-adjustable connecting rods can be actuated via the oil pressure in the crank pin bearings 3c, with the aid of which length-adjusting devices (see FIGS. 1, 2a and 2b) in the connecting rods and thus first and second hydraulic chambers can be selectively loaded with the oil in the connecting rods. For this purpose, a hydraulic feed line 13 is provided, which provides the lubricant with which the crankshaft bearings K and the crank pin bearings 3c are lubricated as a hydraulic medium at or at a pressure or pressure level necessary for actuating the length adjustment devices.

In order to prevent the lubricant introduced into the two crankshaft bearings K via the hydraulic supply line 13 from flowing into the oil supply lines 102a at the pressure required to actuate the length adjustment devices and thus the pressure in the crank pin bearings 3c to drop, the oil supply lines 102a contain the two Check valves 103 lead to crankshaft bearings K, which are also flow-connected to the hydraulic supply line 13.

It is also conceivable that the two oil supply lines 102a, in which the check valves 103 are arranged and which open into the two crankshaft bearings K, with which the hydraulic supply line 13 is connected in terms of flow, are dispensed with. In this case, the remaining oil supply lines 102a open into crankshaft bearings K of a first group and the hydraulic supply line 13 is fluidly connected to crankshaft bearings K of a second group, the two groups not having a common crankshaft bearing K. It should be ensured that not only lubricant used as hydraulic medium for actuating the length adjustment devices, but also for lubricating the crankshaft bearings K and crank pin bearings 3c is provided via the hydraulic feed line 13.

The lubricant or hydraulic medium can be removed by means of a supply device 37 from a lubricant reservoir 38, with which the supply device 37 can be fluidly connected on its input side. The lubricant reservoir 38 is preferably a conventional engine oil pan. The supply device 37 is also preferably set up to divide the lubricant removed from the lubricant reservoir 38 between the lubricant supply arrangement 101 and the hydraulic feed line 13, in that a first portion of the removed lubricant is fed into the lubricant supply arrangement 101, in particular into the main oil line 102, and in second portion of the removed lubricant is passed into the hydraulic supply line 13.

For this purpose, the supply device 37 preferably has a pump 35, which draws in the lubricant on the inlet side in the lubricant reservoir 38 and / or applies an outlet pressure to the outlet side. The lubricant pressure, in particular oil pressure, in the lubricant reservoir 38 essentially depends on the speed of the internal combustion engine or the crankshaft 50. The pump 35 can therefore in particular be set up to generate the outlet pressure independently of the lubricant or engine oil pressure present in the lubricant reservoir 38. In a preferred manner, the pump 35 is set up to apply an outlet pressure to the lubricant which is above the lubricant or engine oil pressure in the lubricant reservoir 38.

The supply device 37 also has a divider arrangement 39 which is set up to regulate the flow, in particular of the lubricant to which the outlet pressure is applied, into the lubricant supply arrangement 101 and / or the hydraulic feed line 13. As shown in FIG. 3, the divider arrangement 39 can each have a controllable flow valve 39a, 39b with which the delivery quantity of the lubricant introduced into the lubricant supply arrangement 101 or the hydraulic feed line 13 and thus also the pressure in the lubricant supply arrangement 101 or the hydraulic feed line 13 can be regulated. The flow valves 39a, 39b can be designed, for example, as throttle valves. However, it is also conceivable to provide orifice valves instead of the flow valves 39a, 39b. Alternatively, the divider arrangement 36 could also be designed as a gearwheel quantity divider.

The supply device 37 can preferably be controlled by a control device 36, for example an engine control unit (ECU), in particular by the first portion of the lubricant removed from the lubricant reservoir 38 in FIG to regulate the lubricant supply arrangement 101 and / or the second portion of the lubricant removed from the lubricant reservoir 38 into the hydraulic feed line 13. For example, if the speed of the internal combustion engine or crankshaft 50 increases and the lubricant pressure in the lubricant reservoir 38 increases, the pump output of the pump 35 can be reduced, for example, by a constant output pressure in the

Ensure lubricant supply arrangement 101 and / or the hydraulic supply line 13. On the other hand, if the pressure in the hydraulic supply line 13 for actuating the length adjustment device is to be increased, e.g. can be raised to or above a predetermined pressure level, e.g. the pump 35 for generating an increased outlet pressure, the first flow valve 39a for reducing the lubricant flow into the lubricant supply arrangement 101 and the first flow valve 39b for increasing the lubricant flow into the hydraulic feed line 13. In this way, the pressure in the

Lubricant supply arrangement 101 can be kept constant, although the pump 35 generates an increased outlet pressure for actuating the length adjustment devices.

The lubricant fed into the hydraulic supply line 13 can be stored in a pressure accumulator 40. A, in particular electrically controllable, 2/2-way valve 41 can, if necessary, establish or interrupt a flow connection between the pressure accumulator 40 and the hydraulic supply line 13. A hydraulic check valve 42 is set up to prevent a pressure drop in the hydraulic feed line 13, even if the supply device 37 does not feed any lubricant into the hydraulic feed line 13, in particular the pump 35 is not operated.

FIG. 4 shows a system 100 according to the invention in accordance with a second preferred embodiment, which differs from the embodiment shown in FIG. 3 in the configuration of the supply device 37. Here, the supply device 37 has a pump 35 with two pump arrangements 35a, 35b, a first pump arrangement 35a being assigned to the lubricant supply arrangement 101, in particular being flow-connectable on the output side thereof, and a second pump arrangement 35b is assigned to the hydraulic supply line 13, in particular can be flow-connected to it on the output side.

The pump 35 has a single, in particular electrical or mechanical, drive 35c which simultaneously drives the two pump arrangements 35a, 35b. The drive 35c is preferably arranged in a common housing 35d, in particular together with the two pump arrangements 35a, 35b.

The pump 35 can be designed, for example, as a rotary vane pump or vane pump with two rotors. The two rotors are each part of one of the two pump arrangements 35a, 35b. The pump arrangements 35a, 35b also preferably have means for setting an eccentricity of the respective rotor with respect to a common drive axis and thus the flow or the delivery quantity of the lubricant conveyed by the respective pump arrangement 35a, 35b.

In order to increase or decrease the first portion of the lubricant removed from the lubricant reservoir 38, which is fed into the lubricant supply arrangement 101, the eccentricity of the rotor of the first pump arrangement 35a can be adjusted accordingly by means of the control device 36, for example. If, on the other hand, the second part of the

Lubricant reservoir 38 removed lubricant, which in the

Hydraulic supply line 13 is guided, increased or decreased, the eccentricity of the rotor of the second pump arrangement 35b can be adjusted accordingly by means of the control device 36. As a result, supply device 37 can provide two volume flows of the lubricant on the output side, in particular independently of one another, and in particular the pressure in the

Lubricant supply arrangement 101 and / or the pressure in the

Regulate hydraulic supply line 13.

FIG. 5 shows a preferred exemplary embodiment of a method 110 according to the invention for setting an effective length of a length-adjustable connecting rod for an internal combustion engine, the connecting rod having at least a first connecting rod part, a second connecting rod part and a length adjusting device Moving the first connecting rod part relative to the second connecting rod part, in that in a first switching state of the length adjusting device, a first hydraulic chamber formed by the first and second connecting rod parts can be filled with a hydraulic medium, and in a second switching state of the length adjusting device, a second hydraulic chamber formed by the first and second connecting rod parts can be filled with a hydraulic medium can be filled. When the first hydraulic chamber has filled to the maximum with hydraulic medium, for example due to mass forces acting on the connecting rod during the stroke, the connecting rod is in a first, long switching position. If, on the other hand, the second hydraulic chamber has filled to the maximum with hydraulic medium, for example due to mass forces acting on the connecting rod during the stroke, the connecting rod is in a second, short switching position.

In a process step S1, a lubricant, e.g. Oil, in particular engine oil, is removed from a lubricant reservoir, in particular an engine oil pan of a vehicle equipped with the internal combustion engine, by means of a supply device. For this purpose, the supply device can be flow-connected on the input side to the lubricant reservoir and preferably has a pump for conveying the lubricant. On the output side, the supply device is connected to a lubricant supply arrangement, via which at least one crankshaft bearing and / or crankpin bearing of the internal combustion engine can be fed with the lubricant. In addition, the supply device is also connected on the output side to a hydraulic feed line, via which the length adjustment device can be fed with the lubricant used as the hydraulic medium. The supply device preferably has separate outputs for connection to the lubricant supply arrangement or the hydraulic supply line.

In a further method step S2, a first portion of the removed lubricant is fed into the lubricant supply arrangement for lubricating the at least one crankshaft bearing and / or crankpin bearing. For this purpose, the supply device can have, for example, a divider arrangement, by means of which the first proportion of the lubricant can be set.

In a further method step S3, a second portion of the removed lubricant is used to move the two connecting rod parts towards and / or into one another, ie for actuating the length adjustment device, passed into the hydraulic feed line. The second portion of the lubricant can preferably also be set by means of the divider arrangement.

Even if the method steps S1, S2, S3 are shown in the form of a flow chart in the present FIG. 5, it is clear to the person skilled in the art that the method steps S1, S2, S3 are preferably carried out essentially simultaneously. In other words, the supply device conveys the lubricant from the lubricant reservoir directly into the lubricant supply arrangement and / or hydraulic feed line, in particular if the at least one crankshaft bearing and / or crankpin bearing is to be lubricated and / or the length adjustment device is to be actuated.

List of reference symbols length-adjustable connecting rod at the longitudinal axis of the connecting rod

small connecting rod eye

a Rotational symmetry axis of the small connecting rod eye large connecting rod eye

a rotational symmetry axis of the large connecting rod eye b connecting rod bearing

c Crank pin bearing

first rod part

second part of the pole

Piston element

a, 6b first, second end face

Mounting screw

Guide cylinder

first hydraulic chamber

0 second hydraulic chamber

1 first oil channel

2 second oil channel

3 hydraulic supply line

4, 15 connecting channels

6 length adjustment device

7 first valve

8 first valve chamber

9 first valve spring

0 first valve body

1 first valve seat

2 second valve

3 second valve chamber

4 second valve spring

5 second valve body

6 second valve seat

7 connecting device 8 connecting element 9 connecting rod

0 control cylinder

1 control piston

2 return spring

3 control room

4 control line 5 pump

5a, 35b first, second pump arrangement 5c drive

5d housing

6 control device

7 utilities

8 engine oil pan

9 divider arrangement

9a, 39b first, second flow valve

0 accumulator

1 2/2 way valve

2 hydraulic check valve

50 crankshaft

100 device

101 Lubricant supply arrangement

102 main oil pipe

102a oil supply

103 check valve

104 supply channels

1 10 procedure

S1 -S3 process steps

K crankshaft bearings e longitudinal median plane

AL adjustment range

Claims

1. system (100) for setting an effective length of a length-adjustable connecting rod (1) for an internal combustion engine, in particular reciprocating piston machine, the connecting rod (1) having at least a first connecting rod part (4) and a second connecting rod part (5) and the two connecting rod parts ( 4, 5) by means of a length adjustment device (16) in the direction of a longitudinal axis (1 a) of the connecting rod parts (4, 5), in particular telescopically, can be moved towards and / or into one another, comprising:

- a lubricant supply arrangement (101), via which at least one crankshaft bearing (K) and / or crankpin bearing (3c) of the internal combustion engine can be loaded with a lubricant;

-a hydraulic supply line (13), via which the

Length adjustment device (16) can be loaded with the lubricant used as the hydraulic medium;

- A supply device (37) which is flow-connectable on the output side both to the lubricant supply arrangement (101) and to the hydraulic feed line (13) and is designed to remove the lubricant from a lubricant reservoir (38) and selectively to lubricate a first portion of the removed lubricant of the at least one crankshaft bearing (K) and / or crankpin bearing (3c) into the lubricant supply arrangement (101) and a second portion of the removed lubricant into the hydraulic feed line (13) for moving the two connecting rod parts (4, 5) and / or to lead into each other.

2. System (100) according to claim 1, characterized in that the supply device (37) has a pump (35) which is set up to remove the lubricant removed from the lubricant reservoir (38), in particular the second portion of the lubricant, with a To apply outlet pressure.

3. System (100) according to claim 2, characterized in that the pump (35) has a first pump arrangement (35a) which is flow-connectable to the lubricant supply arrangement (101), a second pump arrangement (35b) which is connected to the hydraulic feed line (13) is flow-connectable, and has a common drive (35c) for driving the first and second pump arrangement (35a, 35b).

4. System (100) according to claim 2 or 3, characterized in that the supply device (37) has a divider arrangement (39) which is set up to allow the flow of the lubricant acted upon by the outlet pressure into the lubricant supply arrangement (101) and / or regulate the flow of the hydraulic medium into the hydraulic feed line (13) for moving the two rod parts towards and / or into one another.

5. System (101) according to claim 4, characterized in that the divider arrangement (39) has a lubricant supply arrangement (101) assigned first flow valve (39a) and a hydraulic feed line (13) assigned second flow valve (39b).

6. System (100) according to any one of the preceding claims, characterized in that the hydraulic feed line (13) has at least one feed channel (104), wherein the feed channel (104) preferably from the at least one crankshaft bearing (K) to at least one crankpin bearing (3c ) runs.

7. System (100) according to any one of the preceding claims, characterized in that the hydraulic feed line (13) for feeding the length adjustment device (16) with the at least one crankshaft bearing (K) is flow-connected.

8. System (100) according to claim 6 or 7, characterized in that at least one ball shaft bearing (K) has an inlet opening for the supply of lubricant into the supply channel (104), the inlet opening is connected to the flow both with the hydraulic feed line (13) and with the lubricant supply arrangement (101).

9. System (100) according to one of the preceding claims, characterized in that the lubricant supply arrangement (101) has at least one check valve (103), which is set up to discharge the hydraulic line (13) into the at least one crankshaft bearing ( K) to prevent lubricants from being directed into the lubricant supply arrangement (101).

10. System (100) according to one of claims 1 to 6, characterized in that the lubricant supply arrangement (101) with a first group of crankshaft bearings (K) is flow-connected and the hydraulic feed line (13) for loading the length adjustment device (16) with a second Group of crankshaft bearings (K) is connected to the flow, the first group not containing a crankshaft bearing (K) from the second group and the supply device (37) is set up to move alongside the first group of crankshaft bearings (K)

Lubricant supply arrangement (101) also to lubricate the second group of crankshaft bearings (K) via the hydraulic feed line (13) with the lubricant.

11. Method (110) for setting an effective length of a length-adjustable connecting rod (1) for an internal combustion engine, in particular a reciprocating piston machine, the connecting rod (1) having at least a first connecting rod part (4) and a second connecting rod part (5) and the two connecting rod parts ( 4, 5) by means of a length adjustment device (16) in the direction of a longitudinal axis (1 a) of the connecting rod parts (4, 5), in particular telescopically, can be moved towards and / or into one another, wherein

a lubricant is removed from a lubricant reservoir (38) by means of a supply device (37), the supply device (37) on the output side having both a lubricant supply arrangement (101), via which at least one Crankshaft bearing (K) and / or crankpin bearing (3c) of the internal combustion engine can be charged with a lubricant, as well as with a hydraulic feed line (13), via which the

Length adjustment device (16) can be charged with the lubricant used as the hydraulic medium, is flow-connectable,

a first portion of the removed lubricant for lubricating the at least one crankshaft bearing (K) and / or crankpin bearing (3c) is passed into the lubricant supply arrangement (101), and

- A second portion of the removed lubricant for moving the two connecting rod parts (4, 5) to and / or into each other in the

Hydraulic feed line (13) is passed.

12. Internal combustion engine, in particular reciprocating piston engine, with a length-adjustable connecting rod (1) which has at least a first connecting rod part (4) and a second connecting rod part (5), the two connecting rod parts (4, 5) by means of a length adjustment device (16) in the direction of one Longitudinal axis (1 a) of the connecting rod parts (4, 5), in particular telescopically, towards and / or into one another, and a system (100) according to one of claims 1 to 10.