WO2018006904A1

WO2018006904A1 - Arrangement for transferring a pressure medium

Info

Publication number: WO2018006904A1
Application number: PCT/DE2017/100552
Authority: WO
Inventors: Andreas Nendel; Markus Popp
Original assignee: Schaeffler Technologies AG & Co. KG
Priority date: 2016-07-08
Filing date: 2017-06-30
Publication date: 2018-01-11
Also published as: DE102016212466A1

Abstract

In an arrangement for transferring a pressure medium between a crankshaft (36) and a connecting-rod bearing housing (5), mounted on a crank pin (37) of a crankshaft (36), of a connecting rod (1) of a reciprocating piston internal combustion engine, which connecting rod (1) is assigned to a cylinder unit, the pressure medium transfers at a control pressure out of at least one pressure medium inflow (49) which is provided in the crankshaft (36) into at least one pressure medium outflow (57) which is provided in the connecting-rod bearing housing (5). The pressure medium is fed to at least one control chamber of a hydraulically controlled directional valve (26), which directional valve (26) interacts with a device for changing the compression ratio of the cylinder unit which is arranged in the connecting rod (1). In order to improve the load-bearing capability of the connecting-rod bearing and the hydraulic actuation of the directional valve, the at least one pressure medium inflow (49) is to be configured in at least one of the two circularly annular surfaces (48) which extend radially from the crank pin (37) in at least one of the crank webs (46) of the crankshaft (36), wherein the at least one pressure medium outflow (57) is arranged in at least one of the two circularly annular end surfaces of the connecting-rod bearing housing (5), and wherein, during a revolution of the crank pin (37), the respective pressure medium inflow (49) communicates at least in phases with the pressure medium outflow (57) which is assigned to it.

Description

Name of the invention

Arrangement for transmitting a pressure medium

description

Field of the invention

The invention relates to an arrangement for transmitting a pressure medium between a crankshaft and a connecting rod bearing housing mounted on a crank pin of the crank shaft of a Hubkol- benbrennkraftmaschine, wherein the pressure means with a control pressure from at least one provided in the crankshaft pressure medium inlet into at least one in the connecting rod bearing housing provided pressure medium drainage and at least one control chamber of a hydraulically controlled directional control valve is supplied, which directional control valve with a device for changing the compression ratio of the cylinder unit, which is arranged in the connecting rod cooperates.

Furthermore, the invention also relates to a connecting rod for a Hubkolbenbrennkraftmaschi- ne with adjustable compression ratio, the effective length for adjusting the compression ratio is adjustable at least two stages, with at least one hydraulic actuating device, the at least one arranged in a piston rod end of the connecting rod eccentric body, at least two with a Hydraulic fluid acted upon pressure chambers of support cylinders, in each of which a control piston is displaceably guided, and at least two piston rods which each connect an actuating piston with the eccentric body, wherein the actuating device via a directional control valve adjustable and hydraulically lockable in their adjustment positions. State of the art

With the compression ratio of a reciprocating internal combustion engine ε the ratio of the volume of the entire cylinder chamber to the volume of the compression chamber is designated. By increasing the compression ratio can the efficiency of the reciprocating internal combustion engine can be increased, resulting in a total of a reduction in fuel consumption results in the same power of the reciprocating internal combustion engine. However, it must be taken into account that in the case of spark-ignition internal combustion engines with increased compression in full-load operation, their tendency to knock increases.

The knocking is an uncontrolled self-ignition of the fuel-air mixture. On the other hand, in the partial load operation in which the charge is lower, the compression ratio may be increased to improve the corresponding partial load efficiency without the aforementioned knocking occurring. As a result, it is expedient to operate the reciprocating internal combustion engine in part-load operation with a relatively high compression ratio and in full load operation with a reduced compression ratio compared to this.

A change in the compression ratio is also particularly advantageous for supercharged reciprocating internal combustion engines with spark ignition, as these overall in terms of charging a low compression ratio is given, to improve the thermodynamic efficiency in unfavorable areas of a corresponding engine map, the compression is to be increased. In addition, it is possible to change the compression ratio generally depending on other operating parameters of the reciprocating internal combustion engine, such as. of driving conditions of the motor vehicle, operating points of the internal combustion engine, signals of a knock sensor, exhaust gas values, etc.

Among other things, devices are known from the prior art, which make an adjustment of the distance between a crank pin of a crankshaft and a piston pin. These are different devices, namely those with which the position of the piston relative to the connecting rod is variable, or those that make a change in position of the connecting rod relative to the crankshaft. In this case, the connecting rod is connected to the piston via an adjustable eccentric provided on the connecting rod eye, in which a piston pin bearing and a piston pin are arranged. The corresponding eccentric is adjusted by the engine forces occurring in the cylinder unit between the connecting rod on the one hand and the piston pin or the crank pin on the other hand, ie mass and load forces. In the working cycle of the cylinder unit, the acting forces change continuously. It is expedient to connect the eccentric with two actuating pistons, which act on this to its rotation and hydraulic locking tabs. Thus, the rotational movement supported by the actuating piston and a provision of the eccentric, which can occur due to the force transmitted to the eccentric with different directions of force forces can be avoided. The respective function of the adjusting piston is adjustable by a directional control valve which is actuated hydraulically or mechanically and, in the case of a hydraulic actuation, is supplied with pressure medium from a connecting rod bearing via a fluid line.

An arrangement for transferring pressure medium between a crankshaft and a connecting rod bearing housing mounted on a crank pin of the crankshaft for a device for changing a compression ratio of a Hubkolbenbrenn- engine and provided with the device connecting rod of the type described in the preamble of each of claims 1 and 10 are known from DE 10th 2013 1 1 1 616 A1 known. Thereafter, an eccentric arranged in a connecting rod eye of a connecting rod is provided with an eccentric piston pin bore, wherein the eccentric device has diametrically extending tabs on which act on eccentric rods piston. Guide cylinders, which receive these pistons, are supplied with hydraulic fluid from a connecting rod bearing via oil feed lines, in each of which a non-return valve is arranged.

In addition to the respective oil feed line, an oil return line is connected to each of the two guide cylinder, which leads to a fluid-operated via a fluid line switching valve. In the two switching positions, the switching valve should vent one of the two oil return lines into the fluid line acted upon by the engine oil pressure. As a pressure medium, the lubricating oil of the internal combustion engine is used, which via a radially extending Olaustrittsbohrung of the crank pin of the crankshaft and a circumferentially extending groove portion of a bearing is guided in the aforementioned oil supply lines and the fluid line.

Furthermore, from DE 29 20 076 A1 an oil supply of a provided in its lower bearing shell with a oil supply bag connecting rod bearing known. In this case, from a main bearing via a running within a crank arm of a crankshaft fresh oil passage, a lubricating oil supply into an annular channel formed in a front end portion of a connecting rod bearing housing and by a radius between a crank pin and the crank arm and by a flat surface of the crank pin to the interior of the crankcase is closed.

DISCLOSURE OF THE INVENTION It is an object of the present invention to improve the carrying capacity of the connecting rod bearing and the hydraulic control of the directional control valve.

This object is achieved by the features of the respective characterizing part of the independent claims 1 and 10. Advantageous embodiments are set forth in the claims dependent thereon, which in themselves or in various combinations with each other may constitute an aspect of the invention.

Thereafter, in an arrangement for transmitting a pressure medium between a crankshaft and a connecting rod bearing housing mounted on a crank pin of the crank shaft of a piston engine of a reciprocating internal combustion engine, the pressure medium with a control pressure from at least one provided in the crankshaft Druckmittelzufluss in at least one provided in the connecting rod bearing housing pressure medium outflow above. Under the connecting rod bearing housing is the section of the connecting rod, which encloses the crank pin of the crankshaft to form a Pleuellagerauges. The pressure medium is supplied to at least one control chamber of a hydraulically controlled directional valve, which cooperates with a device for changing the compression ratio of the cylinder unit, which is arranged in the connecting rod. Under pressure medium inflow is at Reciprocating internal combustion engines usually understood a lubricating oil supply channel, by means of which pressurized lubricating oil is led to a point of consumption, in which it serves for lubricating a bearing or for the hydraulic control or actuation of hydraulic components.

According to the invention, the at least one pressure medium inflow in at least one of the two annular surfaces which, radially extending from the crank pin, is formed in at least one of the crank webs of the crankshaft. The cooperating with this at least one pressure medium outlet is arranged in at least one of the two annular end faces of the connecting rod bearing housing, so that during a revolution of the crank pin communicates the respective Druckmittelzufluss at least in phases with this associated pressure medium drain. The pressure medium supply of the adjusting device thus takes place in a region of the crank mechanism, which does not serve for the storage of the connecting rod bearing eye on the Kur- pin. It is therefore not necessary to provide grooves, collecting pockets and / or bores in a plain bearing or oil feed pocket disposed in the connecting rod bearing eye or additional bores in the outer circumferential surface of the crank pin, which would considerably reduce the bearing capacity. It is essential that the lubricating oil serving as hydraulic fluid passes by means of the pressure medium transmission according to the invention from the respective crank arm into the connecting rod bearing housing, wherein it flows parallel to the longitudinal center axis of the connecting rod bearing eye. Therefore, the pressure medium transmission between the crank pin and the connecting rod bearing housing is completely separated from the storage and therefore does not affect them. To prevent pressure pulsations in the hydraulic control and adjustment system, the pressure medium inflow can be arranged in the crank arm such that it is connected exclusively to the pressure fluid outflow of the connecting rod housing within a phase in which the crank pin is in the area of a bottom dead center.

In contrast, according to DE 10 2013 1 1 1 616 A1 a pressure medium transfer is provided, in which the pressure medium radially emerging from an oil outlet transverse bore of the crank pin is fed to a circumferentially extending collection pocket of the plain bearing designed as a plain bearing. As already explained, Such radial pressure medium transmission adversely affects the bearing capacity of the connecting rod bearing. This can only be realized in that, as provided according to the publication, pressure medium is supplied via the radial Olaustrittsbohrung the collection bag or a collecting groove of the sliding bearing, or a recess in the outer circumferential surface of the crank pin is provided which communicates with a Ölsammelboh- tion in plain bearings , In both cases, however, the carrying capacity of the connecting rod bearing is adversely affected.

From DE 2 920 076 A1, although a pressure medium supply via the running in the crank pin fresh oil passage is provided, which supplies the pressure fluid to the connecting rod bearing housing from the front side. In this case, however, the width of the connecting rod bearing is reduced, so that within a free-lasting region of the connecting rod bearing eye, a circumferential annular channel can be provided. This is formed with a radial depth in Pleuellagerauge and from this extends an oil supply in the axial direction in a lower bearing shell to an oil supply bag, which is also provided in this bearing shell. There are thus differences in the type of pressure medium supply and in the exclusive use of this pressure medium for lubrication of the connecting rod bearing according to the prior art. In a further embodiment of the invention, the Druckmittelzufluss should be formed as concentric with the crank pin outlet groove extending over a portion of the annular surface, and it should be designed as the discharge groove in the axial direction of the crank pin opposite the pressure fluid drain, formed in the connecting rod bearing housing fluid bore. The lateral surface of the respective crank pin usually merges into a radius, which is adjoined by a machined surface of the crank arm, which has an annular outer contour. Within this annular surface to extend concentric to the crank pin outlet groove. This is a fluid bore of the bearing mounted on the crank pin connecting rod bearing housing opposite, wherein said outlet groove form the pressure fluid inlet and the fluid bore the pressure fluid drain.

During one revolution of the crank pin in the connecting rod bearing housing thus the outlet groove is in phases with the fluid bore in connection. The phased Pressure medium transfer is important in reducing pressure pulsations, which can lead to faulty operations of the directional control valve, as these can be reduced to a minimum. Depending on the crank radius of the crank mechanism and the crankpin diameter, pressure changes may occur in the fluid bore, which may amount to Δρ = 5.4 (-0.7 to +4.7 bar) depending on the speed of the reciprocating internal combustion engine.

Due to the particular position of the outlet groove to the position of the fluid bore prevents the positive and negative pressure peaks of the oscillatory varied control pressure, which are particularly in the high speed range in a wide pressure fluctuation range, are transmitted to the control chamber of the directional control valve. In movement phases of the crank pin and thus of the connecting rod, in which high acceleration forces act on the pressure medium in the oil guide of the crank webs and in the fluid channel, the pressure medium transfer should be interrupted.

It is further provided that in the fluid bore, a spool of the preferably designed as a 3 / 2- or 4/2 way valve directional control valve is arranged and that the spool is received by a pressed-in a first receiving bore of the connecting rod bearing housing valve housing. The fluid bore can thus be formed as a valve receiving bore which receives a valve housing of the directional control valve. This valve receiving bore is formed as a through hole, which preferably extends in a stepped manner and parallel to the longitudinal central axis of the connecting rod bearing within the connecting rod bearing housing. In the valve housing also radially extending return bores, which are connected to the return lines, arranged, and further located in the valve housing radially extending discharge holes through which the outflow of the adjusting pressure medium directly to the connecting rod bearing or this indirectly via the oil supply lines also the connecting rod bearing is supplied , The spool is supported in the valve housing via a valve spring and is acted upon at its side facing away from the valve spring end face with the fluid pressure from the pressure medium transfer. When using a 3/2 way valve, a discharge channel is provided, while in the 4/2 way valve the diverted pressure medium can be fed to two different outflow channels. In addition, a sliding seal can be provided between the pressure medium inflow and the pressure medium outflow. By means of the sliding seal leaks in the area of the pressure medium transfer are to be avoided. This seal may optionally enclose the fluid bore or the exit groove.

The grinding seal preferably has a sealing element, which is displaceably guided in a valve housing of the directional control valve and resiliently supported relative thereto by means of a biasing spring, wherein the sealing element sealingly abuts the annular surface of the crank arm with a sealing surface facing away from the biasing spring. It is essential that due to the arrangement of this sealing element no leakage oil flows at the transition from the crank arm to the connecting rod bearing housing arise, which would otherwise make negative impact in the control of the directional control valve. In this case, the sealing element may be made of aluminum or of a plastic, for example PTFE. Since the sealing element is resiliently supported by the biasing spring on the valve housing, it can be tracked under the action of this biasing spring in case of wear.

According to a further embodiment of the invention, the concentric with the crank pin extending outlet groove in predetermined rotational angles of the crank pin with at least one formed in the annular end surface of the connecting rod bearing housing, concentrically extending inlet groove is connectable, wherein the inlet groove extends outside the region of the fluid bore. On the same radius as the fluid bore thus the aforementioned entrance groove is formed in the end face of the connecting rod bearing housing. The pressure medium supplied to this inlet groove is provided on the one hand for the lubrication of the connecting rod bearing and on the other hand it is to be supplied to the pressure chambers of support cylinders via oil supply lines running inside the connecting rod shaft.

Furthermore, radially spaced from the directional control valve, extending parallel to this, within a second receiving bore of a connecting rod stem of the connecting rod with an oil zulaufbohrungen an adjusting device of the device for varying the compression ratio of the cylinder unit, a valve module may be arranged, which receives a check valve for each of the oil inlet holes. The second receiving bore is provided at a relatively small distance from the directional control valve and into which the abovementioned valve module is inserted, which receives the two check valves assigned to the oil inlet bores. In this case, the two non-return valves can be used from one end face of the valve module, that is, arranged in different bores. But it is also possible to provide the valve module with a single through hole into which the two check valves are each inserted from one of the two end faces. In addition, it is also possible to make this valve module so that the check valves are arranged in radial bores of the valve housing.

Each of the cylinder units, running in a main bearing block of a crankcase of the reciprocating internal combustion engine, associated with a lubricant supply line and a signal pressure line, which open so separated from each other in the main bearing, that in the different rotational positions of a shaft journal via an inlet bore provided in this pressure medium from the lubricant supply line or the signal pressure line a leading inside the crank arm to the pressure medium inflow of the pressure medium transfer pressure medium channel is supplied. The lubricant supply line is acted upon with the normal lubricant pressure of the oil pump. The signal pressure line can, starting from a higher control pressure delivering pump via a designed as a 4/2-way valve switching valve acted upon with a control pressure or relieved of pressure from the level of normal lubricant pressure. In this case, the switching valve is preferably controlled electromagnetically and provided with a spring return. At the start of the reciprocating internal combustion engine, all the switching valves are in a preferred starting position, in which they are moved over the return spring and in which each of the cylinder units is operated with a high compression.

It can further branch off within the crank arm from the pressure medium channel, a lubricating oil passage which is connected to a radial oil outlet in the crank pin. The branching lubricating oil channel promotes a sufficient amount of lubricant in - L ü the radial oil outlet of the crank pin, so that the connecting rod bearing has an uninterrupted oil supply.

Finally, a connecting rod for a reciprocating internal combustion engine with adjustable compression ratio for adjusting the compression ratio in its effective length should be at least two stages adjustable. This is provided with at least one hydraulic adjusting device for adjusting its effective length, the at least one arranged in a piston rod end of the connecting rod eccentric body, at least two acted upon by a hydraulic fluid pressure chambers of support cylinders, in each of which a control piston is slidably guided, and at least two piston rods, each having an actuating piston connect to the eccentric body has. In this case, the adjusting device is adjustable via a directional control valve and hydraulically locked in their adjustment positions. As explained above, a pressure medium transmission is provided between a pressure medium inflow of a crankshaft and a pressure medium outflow of a connecting-rod bearing housing, which is embodied according to one of the above solutions.

The invention is not limited to the specified combination of the features of the independent claims 1 and 10 with the dependent claims. In addition, there are further possibilities of combining individual features, in particular if they result from the patent claims, the following description of the exemplary embodiments or directly from the figures. In addition, the reference of the claims to the figures by the use of reference numerals is not intended to limit the scope of the patent claims to the illustrated embodiments.

Short description of the drawing

For further explanation of the invention reference is made to the drawings, in which several different embodiments are shown in simplified form. Show it: 1 shows a longitudinal section through a connecting rod, wherein the position of a piston pin bearing with respect to the connecting rod is variable via an eccentric lever cooperating with support cylinders,

2 shows a section through a main bearing block with a lubricant supply line and a signal pressure line,

Figure 3 shows a perspective view of a part of a crankshaft with a longitudinal section through a main bearing block, two crank webs and a

Crank pin, wherein a pressure medium channel passes through one of the crank webs,

Figure 4 shows a perspective view of a part of a crankshaft with a longitudinal section through a main bearing block, two crank webs and a

Crank pin, wherein a pressure medium channel extends through one of the crank webs and branches off from the pressure medium channel, a lubricating oil passage,

Figure 5 shows a section in the region of a transition from a crank arm in the

Crankpin and a partial view of a connecting rod,

7 shows a schematic view of a crankshaft with connecting rods for cylinder units I, II and III arranged on its crank pin, FIG.

8 shows a longitudinal section through a connecting rod arranged on a crank pin, the connecting rod bearing housing having on its front side both the directional valve and a concentrically running inlet groove for the pressure medium which can be supplied to the oil supply lines,

9 shows a hydraulic scheme according to the invention, which is connected to the pressure medium drainage of the pressure medium transmission and Figure 10 shows the hydraulic diagram whose connection to the pressure medium transfer and the different overlaps of the pressure medium outflow are shown with the pressure medium inflow.

Detailed description of the drawing

In FIG. 1, 1 denotes a connecting rod for a cylinder unit of a reciprocating internal combustion engine, which consists of a connecting rod upper part 3, partly designed as a connecting rod shank 2, and a connecting rod lower part 4. The connecting rod upper part 3 and the Pleuelunterteil 4 together form a connecting rod bearing housing 5 with a connecting rod bearing eye 5a, via which the connecting rod 1 can be mounted on a crank pin, not shown, a crankshaft. At its other end, the connecting rod upper part 3 is provided with a connecting rod eye 6 in which an eccentric body 7, a piston pin not shown in detail in FIG. 1, can be arranged in a piston pin bearing eccentrically extending within the eccentric body 7.

About the rotatably guided in the piston pin bearing 8 piston pin a likewise not shown working piston of a cylinder unit of Hubkolbenbrennkraft- machine is guided on the eccentric body 7, wherein a rotation of the eccentric body 7 in a direction to set a relatively low compression ratio and its rotation in the opposite direction to adjust a higher compression ratio leads. The eccentric body 7 is adjusted by the engine forces occurring in the cylinder unit between the connecting rod 1 on the one hand and the piston pin bearing 8 and the crank pin on the other hand, ie mass and gas forces. During the working process of the cylinder unit, the acting forces change continuously. With the Exzenterkörper 7 designed as a two-armed lever eccentric lever 9 is rotatably connected, the diametrically extending tabs 10 and 1 1, wherein these are respectively connected via piston rods 12 and 13 with single-acting actuator piston 14 and 15. The piston rods 12 and 13 are each pivotally connected via a bolt 16 with the tabs 10 and 1 1. The adjusting pistons 14 and 15 engage on the aforementioned components on the eccentric body 7 to this to allow a twist or support him in the respective position. Thus, by the adjusting pistons 14 and 15, the rotational movement of the eccentric body 7 is supported or its provision, which would be caused due to the force transmitted to the eccentric body 7 with different directions of force forces, can be avoided.

The adjusting pistons 14 and 15 together with cylinder bores 17 and 18, in which they are guided, support cylinders 19 and 20, each support cylinder 19 and 20 having a pressure chamber 21 and 22, respectively. The support cylinder 19 is, as the diameter can be seen, provided on the mass force side, while the support cylinder 20 of the gas force side support of the eccentric lever 9 is used. In the pressure chambers 21 and 22 may from the connecting rod bearing housing 5 serving as a hydraulic medium lubricating oil of the reciprocating internal combustion engine via oil supply lines 24 and 25 flow. The connecting rod bearing eye 5a adjacent a directional control valve 26 is arranged in the connecting rod bearing housing 5, whose longitudinal axis is parallel to a longitudinal central axis 23 of the connecting rod bearing eye 5a. Furthermore, located in the connecting rod shaft 2, a valve module 27 which receives two check valves 28 and 29, each of which is assigned to one of the oil supply lines 24 and 25. Of the check valves 28 and 29 lead portions 24a and 25a of the oil supply lines 24 and 25 to the connecting rod bearing eye 5a. In addition, from the oil feed line 24 in the region between the check valve 28 and the pressure chamber 21, an oil return line 30 branches off, which leads to the directional control valve 26. In the same way, a corresponding region of the oil feed line 25 is connected via an oil return line 31 to the directional control valve 26. For the purposes of the entire disclosure, bores or channels, which receive the pressure medium and conduct it, are to be understood as pipes.

In FIG. 2, a main bearing block 32 is shown in section, wherein the latter has a bearing block upper part 33, which is designed jointly with a crankcase, not shown, and a bearing block lower part 34 which can be screwed thereto. The same arrangement is shown in a perspective partial view, also in section, in FIG. In the main bearing block 32, a shaft journal 35 of a crankshaft 36 is mounted relative to the crankcase, for which the main bearing block 32 receives a two-part sliding bearing 38, that is, two bearing shells 39 and 40. FIG. 2 also shows the arrangement of a working piston 79 of the reciprocating internal combustion engine. machine, which is connected via a piston pin 80 with the eccentric body 7, out.

As can be seen from FIG. 3, the crankshaft 36 also has a crank pin 37. The bearing shells 39 and 40 are provided with recesses 41 and 42, which emerge in detail from the figure 10 and are explained for this. These provide in phases a connection between a signal pressure line 43 and a lubricant supply line 44 on the one hand and a radial inlet bore 45 in the shaft journal 35 on the other hand. The inlet bore 45 is connected to a within a crank arm 46 of the crankshaft 37 extending pressure medium passage 47. In addition, at the other end of the crank pin 37, a further crank arm 46 '. The crank web 46 has an annular surface 48 on which the pressure medium channel 47 ends as a pressure medium inlet 49. This pressure medium inflow 49 is, as also apparent from the other figures, phased with a fluid bore 50 in connection, in which the directional control valve 26 mentioned in Figure 1 is arranged. Above this directional valve 26, as further shown in the figure 3, a valve module 52 is provided.

FIG. 4 relates to an exemplary embodiment of the invention, which is modified compared to the exemplary embodiment of FIG. 3, in that a lubricating oil channel 53 branches off from the pressure medium channel 47 and is connected to a radial oil outlet 54 in the crank pin 37. Via this radial oil outlet 54, a connecting rod bearing 55 shown in FIG. 3 is lubricated. From the figure 5 is due to a section through the crank arm 46 in the region of the transition into the crank pin shown that the Druckmittelzufluss 49 may be formed as a segmental recess 56, wherein in the illustration a position of the crank arm 46 is shown to the connecting rod bearing housing 5, in an overlap between this segment-like recess 56 and a fluid bore 50 formed as the pressure fluid drain 57 comes about. From this segment-like recess 56 may also emanate a not shown exit groove which extends over a portion of the annular surface 48 of the crank arm 46. Furthermore, the position of the valve module 52 within the connecting rod shaft 2 is apparent from this illustration. For this purpose is within the connecting rod 2 a likewise parallel to the longitudinal central axis 23 extending receiving bore 58 is provided.

FIG. 6 shows in a section the arrangement of the directional control valve 26 in the connecting rod bearing housing 5. The directional control valve 26 has a valve housing 59 and a control slide 60 guided longitudinally displaceably in said valve. In the valve housing 59, a longitudinally extending stepped bore 61 is formed, in which the spool 60 is displaceable under the pressure of the fluid bore 50 against a trained as a compression spring valve spring 62. Furthermore, the spool has a circumferential cam groove 63, via which, depending on the position of the spool 60, one of two return channels 64 and 65 is selectively connectable to a discharge channel 66.

In the illustration according to FIG. 6, the control slide 60 is displaced by the valve spring 62 into a position in which the return passage 64 is connected to the discharge passage 66. An increase in the control pressure in the fluid bore 50 causes the spool 60 is displaced against the force of the valve spring 62 in a position in which it connects the return passage 65 with the discharge channel 66. It is provided that the return channel 64 is connected to the oil return line 31, while the return channel 65 is to be connected to the oil return line 30. Between the oil return lines 30 and 31 and the return channels 65 and 64, a respective aperture 67 and 68 is provided. The entire directional control valve 26 is arranged in a receiving bore 69 of the connecting rod bearing housing 5. Furthermore, it is apparent from FIG. 6 that in the region of the pressure medium inflow in the valve housing 59, a sealing element 70 is arranged, which abuts with a sealing surface 71 on the annular surface 48 and is biased in the axial direction via a biasing spring 72.

FIG. 7 shows, on the basis of a hydraulic diagram, the pressure medium supply of a total of four main bearing blocks via which the crankshaft 36 is mounted, wherein only the shaft journals 35, 35 ', 35 "and 35"' of the crankshaft are shown. It is a reciprocating internal combustion engine with 3 cylinder units I, II, and III. About main bearing blocks, which are associated with shaft journals 35, 35 'and 35 ", by means of the pressure medium supply described above, the pressure medium in the Fluid bore 50 and are promoted in the oil supply lines 24 and 25 of the adjustment, in addition, the lubrication and cooling of the corresponding main bearing and connecting rod bearing is to be ensured. To promote the pressure medium and to change the pressure medium pressure, a variable displacement pump 73 is provided, which promotes the pressure medium to a trained as a 3/2 way valve switching valve 74 which is electromagnetically actuated and via a compression spring 75 assumes a switching position, in all cylinder units a high Compression ratio is set. In this position, the switching valve 74 is held by the compression spring 75 even after stopping the reciprocating internal combustion engine, ie in the de-energized state of the electromagnet, so that the subsequent starting process is also carried out with a high compression ratio.

From the switching valve 74, the signal pressure line 43 leads to the main bearing block of the shaft journal 35 and from this also branch off further signal pressure lines 76 and 77 leading to the shaft journals 35 'and 35 ". Incidentally, the variable displacement pump 73 is parallel to this valve arrangement via the lubricant supply line 44 With regard to the forwarding of the pressure medium from the respective main bearing block, reference is made to the explanations in connection with FIGS. 2 and 3 with respect to the forwarding of the pressure medium from the respective main bearing block.

FIG. 8 shows a longitudinal section through the connecting rod 1, wherein, as already described, the directional control valve 26 is arranged in the connecting rod housing 5 within the fluid bore 50 and the valve module 52 is located above the latter in the receiving bore 58. In this case, the two check valves 28 and 29 are arranged in parallel bores. Furthermore, it is apparent from the figure 8 that the connecting rod bearing housing 5 is provided at the end with a concentric inlet groove 78 through which the pressure medium, starting from the Druckmittelzufluss 49 both in the two oil feed lines 24 and 25 and for lubrication in the connecting rod bearing 45 is performed ,

Consistent with this, the corresponding hydraulic scheme for the adjusting device is shown in FIG. Consequently, via the pressure medium inlet 49, which is formed in the annular surface 48 of the crank arm 46, pressure means of Fluid bore 50 is supplied. This acts as a control line and acts on the spool 60 of the directional control valve 26 frontally against the force of the valve spring 62. Due to the rotation of the crank pin 37 of Druckmittelzufluss 49 reaches a position in which it communicates with the entrance groove 78. This is connected in phases with the two oil supply lines 24 and 25 or via the fluid channel 50 with the directional control valve 26. In the two oil return lines 30 and 31, the above-mentioned apertures 67 and 68 are arranged.

This hydraulic scheme is also part of Figure 10, from which for the aforementioned cylinder units I, II and III, the different positions of the inlet bores 45, 45 'and 45 "opposite the recesses 41 and 42 for the signal pressure and for the lubricating oil pressure are shown In this case, via the inlet bore 45 of the shaft journal 35 for the cylinder unit III pressure medium via the signal pressure line 43 and thus through the crank cheek 46 in the Druckmittelzu- flow 49 of the annular surface 48. The rest of this representation corresponds to that of FIG ,

LIST OF REFERENCE NUMBERS

1 connecting rod

2 connecting rod shaft

3 connecting rod upper part

4 connecting rod base

5 connecting rod bearing housing

5a connecting rod eye

6 connecting rod eye

7 eccentric body

8 piston pin bearings

9 eccentric lever

10 tab

1 1 tab

12 piston rod

13 piston rod

14 adjusting pistons

15 actuating pistons

16 bolts

17 cylinder bore

18 cylinder bore

19 support cylinders

20 support cylinders

21 pressure chamber

22 pressure chamber

23 longitudinal central axis of 5a

24 oil supply line

24a section of 24

25 oil supply line

25a section of 25

26 way valve

27 valve module

28 check valve

29 check valve 30 oil return line

31 oil return line

32 main bearing block

33 Lagerbockoberteil

34 Bearing base

35 shaft journals

35 'shaft journal

35 "shaft journal

35 "'shaft journal

36 crankshaft

37 crankpins

38 plain bearings

39 upper bearing shell

40 lower bearing shell

41 recess for signal pressure

42 recess for lubricating oil pressure

43 signal pressure line

44 Lubricating supply line

45 inlet hole

46 crank arm

46 'crank arm

47 pressure medium channel

48 annular surface

49 pressure medium inflow

50 fluid bore

52 valve module

53 lubricating oil channel

54 radial oil outlet

55 connecting rod bearings

56 segmental recess

57 Pressure fluid drain

58 receiving hole for 52

59 valve housing

60 control slide 61 stepped bore

62 valve spring

63 tax credit

64 return channel 65 return channel

66 outflow channel

67 aperture

68 aperture

69 receiving bore 70 sealing element

71 sealing surface

72 preload spring

73 variable pump

74 switching valve 75 compression spring

76 signal pressure line

77 signal pressure line

78 entrance groove

79 working piston 80 piston pin

Claims

claims

1 . Arrangement for transferring a pressure medium between a crankshaft (36) and a connecting rod bearing housing (5) mounted on a crank journal (37) of a connecting rod (1) of a reciprocating internal combustion engine assigned to a cylinder unit, wherein the pressure fluid comprises at least one control pressure one in the crankshaft (36) provided pressure medium inflow (49) in at least one in the connecting rod bearing housing (5) provided pressure fluid drain (57) and at least one control chamber of a hydraulically controlled directional control valve (26) is supplied, which directional control valve (26) with a device for changing the compression ratio of the cylinder unit, which is arranged in the connecting rod (1) cooperates, characterized in that the at least one pressure medium inflow (49) in at least one of the two annular surfaces (48) extending radially from the crank pin (37) ersteckend, in at least one of the crank webs (46) of the crankshaft (36 ), that the at least one pressure medium outflow (57) is arranged in at least one of the two annular end faces of the connecting rod bearing housing (5) and that during a rotation of the crank pin (37) the respective pressure medium inlet (49) at least in phases with the pressure medium discharge associated therewith ( 57) communicates.

2. Arrangement according to Patent Claim 1, characterized in that the pressure medium inflow (49) as concentric with the crank pin (37) extending outlet groove (56) is formed, which extends over a portion of the annular surface (48), and that the pressure medium outflow (57 ) as the discharge groove (56) in the axial direction of the crank pin (37) opposite, in the connecting rod bearing housing (5) formed fluid bore (50) is executed.

3. Arrangement according to claim 2, characterized in that in the fluid bore (50) a spool (60) of the preferably designed as a 3 / 2- or 4/2 way valve directional control valve (26) is arranged and that the spool (60) of one in a first receiving bore (69) of the connecting rod bearing housing (5) pressed-th valve housing (59) is received.

4. Arrangement according to Patent Claim 1, characterized in that a sliding seal is provided between the pressure medium inlet (49) and the pressure medium outlet (57).

5. Arrangement according to Patent Claim 4, characterized in that the seal has a sealing element (70) which is displaceably guided in a valve housing (59) of the directional control valve (26) and resiliently supported relative thereto by means of a biasing spring (72), and that Sealing element (70) with a biasing spring (72) facing away from the sealing surface (71) sealingly against the annular surface (48) of the crank arm (46).

6. Arrangement according to Patent Claim 2, characterized in that concentric with the crank pin (37) extending outlet groove (56) in predetermined rotational angles of the crank pin (37) with at least one in the annular end face (48) of the connecting rod bearing housing (5) formed concentrically Inlet groove (78) is connectable, wherein the inlet groove (78) extends outside the region of the fluid bore (50).

7. Arrangement according to claim 1, characterized in that radially spaced from the directional control valve (26), parallel to this, within a second receiving bore (58) of a connecting rod shaft (2) of the connecting rod (1) with a gene Ölzulaufleitun- (24 and 25 ) an adjusting device (19, 20) of the device for changing the compression ratio of the cylinder unit, a valve module (52) is arranged, which receives a check valve (28, 29) for each of the oil supply lines (24 and 25).

8. Arrangement according to claim 1, characterized in that, associated with each of the cylinder units, in a main bearing block (32) of a crankcase of the reciprocating internal combustion engine, a lubricant supply line (44) and a signal pressure line (43) extend, so separated from each other in the main bearing (39, 40) lead in that in the different rotational positions of a shaft journal (35) via an inlet bore provided in this pressure medium from the lubricant supply line (44) or the signal pressure line (43) within the crank cheek (46) leading to the pressure fluid inlet (49) of the pressure medium transfer pressure medium channel (47) is supplied.

9. Arrangement according to claim 8, characterized in that within the crank arm (46) from the pressure medium channel (47) branches off a lubricating oil passage (53) which is connected to a radial oil outlet (54) in the crank pin (37).

10. connecting rod (1) for a reciprocating internal combustion engine with adjustable compression ratio, the effective length for adjusting the compression ratio is at least two stages adjustable, with at least one hydraulic adjusting device, the at least one in a piston-side connecting rod eye (6) of the connecting rod (1) arranged eccentric body (7 ), at least two acted upon by a hydraulic fluid pressure chambers (21, 22) of support cylinders (19, 20), in each of which a control piston (14, 15) is displaceably guided, and at least two piston rods (12, 13), each having an actuating piston (14, 15) with the eccentric body (7) connect, wherein the adjusting device via a directional control valve (26) is adjustable and hydraulically lockable in their adjustment positions, characterized by a formation of an arrangement for transmitting a pressure medium between a crankshaft (36) and one on a crank pin (37) of the crankshaft (36) mounted P Leay bearing housing (5) of a cylinder unit associated with a connecting rod (1) according to one of the claims 1 to 9.