• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
  • 法律状态
  • 优先权
    • 专利摘要:
    The invention relates to a length-adjustable connecting rod (1) for a piston engine, the connecting rod (1) having a first connecting rod eye (7) for receiving a piston pin and a second connecting rod eye (4) for receiving a crankshaft pin, the distance between the piston pin and the crankshaft journal is adjustable in the longitudinal direction (A) of the connecting rod (1) by means of a hydraulic control device (21) with a hydraulic control valve (34). The hydraulic control device (21) has a control cylinder (36), a control slide (35) which is displaceably guided in the control cylinder (36) and can be pressurized and at least one drain valve (41, 42) which can be actuated by the control slide (35). The hydraulic control valve (34) has a drainage channel (32) which is between a first (38 ') and a second control pressure chamber (38) which are delimited by a first (46') and a second control pressure surface (46) of the control spool (35) , opens into the control cylinder (36) and is in fluid communication with the at least one drain valve (41, 42). The invention also relates to the use of such a length-adjustable connecting rod (1) with a hydraulic control device (21) in a piston engine and a corresponding piston engine.
    公开号:AT521269A4
    申请号:T50869/2018
    申请日:2018-10-08
    公开日:2019-12-15
    发明作者:Heller Malte；Kai Arens Dr；Riba Zóltan；Bodensteiner Martin；Latz Steffen
    申请人:Avl List Gmbh；Iwis Motorsysteme Gmbh & Co Kg；
    IPC主号:
    专利说明:

    Summary
    The invention relates to a length-adjustable connecting rod (1) for a piston engine, the connecting rod (1) having a first connecting rod eye (7) for receiving a piston pin and a second connecting rod eye (4) for receiving a crankshaft pin, the distance between the piston pin and the crankshaft journal is adjustable in the longitudinal direction (A) of the connecting rod (1) by means of a hydraulic control device (21) with a hydraulic control valve (34). The hydraulic control device (21) has a control cylinder (36), a control slide (35) which is displaceably guided in the control cylinder (36) and can be pressurized and at least one drain valve (41, 42) which can be actuated by the control slide (35). The hydraulic control valve (34) has a drainage channel (32) which is between a first (38 ') and a second control pressure chamber (38) which are delimited by a first (46') and a second control pressure surface (46) of the control spool (35) , opens into the control cylinder (36) and is in fluid communication with the at least one drain valve (41, 42). The invention also relates to the use of such a length-adjustable connecting rod (1) with a hydraulic control device (21) in a piston engine and a corresponding piston engine.
    Fig. 1/26
    PP32168AT
    AVL List GmbH, iwis motorsysteme GmbH & Co. KG
    Hydraulic control valve for a length-adjustable connecting rod with two control pressure chambers
    The present invention relates to a length-adjustable connecting rod for a piston engine, the connecting rod having a first connecting rod eye for receiving a piston pin and a second connecting rod eye for receiving a crankshaft pin, the distance between the piston pin and the crankshaft pin in the longitudinal direction of the connecting rod using a hydraulic control device with hydraulic Control valve is adjustable, and wherein the hydraulic control valve has a control cylinder and a slidably guided in the control cylinder, pressurizable, control slide and at least one drain valve. The invention further relates to the use of such a length-adjustable connecting rod and a piston engine with a length-adjustable connecting rod.
    In the case of internal combustion engines with reciprocating pistons, efforts are being made to change the compression ratio during operation and to adapt it to the particular operating state of the engine in order to improve the thermal efficiency of the internal combustion engine. As the compression ratio increases, the thermal efficiency increases, but too high a compression ratio can lead to unintentional auto-ignition of the piston engine. Such an early combustion of the fuel not only leads to unsteady running and the so-called knocking of the engine, but can also lead to component damage to the engine. In the partial load range, the risk of auto-ignition is lower, so that a higher compression ratio is possible.
    There are different solutions for realizing a variable compression ratio (VCR), with which the position of the crank pin of the crankshaft or the piston pin of the reciprocating piston is changed or the effective length of the connecting rod is varied. There are solutions for continuous and discontinuous adjustment of the components. A continuous length adjustment of the distance between the piston pin and the crankshaft journal enables the compression ratio to be adjusted smoothly to the respective operating point and thus an optimal efficiency of the internal combustion engine. In contrast, discontinuous adjustment of the connecting rod length with just a few steps results in structural and operational advantages and still enables a significant improvement in efficiency compared to a conventional piston engine, as well as corresponding savings in consumption and pollutant emissions.
    / 26
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    EP 1 426 584 A1 describes a discontinuous adjustment of the compression ratio for a piston engine, in which an eccentric connected to the piston pin of the reciprocating piston enables the compression ratio to be adjusted, the eccentric being fixed in the respective end positions of the swivel range by means of a mechanical locking device. In contrast, DE 10 2005 055 199 A1 discloses a length-adjustable connecting rod with which different compression ratios can be achieved, the eccentric being fixed in its position by two cylinder-piston units and the hydraulic pressure difference of the supplied engine oil.
    WO 2013/092364 A1 shows a length-adjustable connecting rod with connecting rod parts which can be telescopically pushed into one another, one connecting rod part having an adjusting piston and the second connecting rod part having a cylinder in which the adjusting piston is arranged to be longitudinally movable. This cylinder-piston unit is supplied with engine oil via a hydraulic control device with an oil pressure-dependent control valve in order to adjust the length of the connecting rod.
    Another telescopically length-adjustable connecting rod is described in WO 2015/055582 A2, the adjusting piston provided in the first connecting rod part dividing the cylinder into two pressure chambers, which are supplied with engine oil by a hydraulic control device. The two pressure chambers of this cylinder-piston unit are supplied with engine oil via check valves, engine oil being only under pressure in one pressure chamber. If the length-adjustable connecting rod is in the long position, there is no engine oil in the upper pressure chamber, whereas the lower pressure chamber is completely filled with engine oil. During operation, the connecting rod is subjected to alternating tensile and compressive loads due to the gas and mass forces. In the long position of the connecting rod, a tensile force is absorbed by the mechanical contact with the upper stop of the adjusting piston. This does not change the connecting rod length. An acting pressure force is transferred via the piston surface to the lower pressure chamber filled with engine oil. Since the check valve of this chamber prevents the return of the engine oil, the pressure of the engine oil increases so that the connecting rod is hydraulically locked in this direction. The connecting rod length does not change here either. In the short position of the length-adjustable connecting rod, the conditions in the cylinder-piston unit are reversed. The lower pressure chamber is empty, while the upper pressure chamber is filled with engine oil. Accordingly, a tensile force causes an increase in pressure in the upper chamber and a hydraulic locking of the length-adjustable connecting rod, while a compressive force is absorbed by the mechanical stop of the adjusting piston.
    / 26
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    AVL List GmbH, iwis motorsysteme GmbH & Co. KG
    The connecting rod length of this length-adjustable connecting rod can be adjusted in two stages by emptying one of the two pressure chambers, one of the two check valves in the inlet channel being bridged by a corresponding return channel. Engine oil flows through these return channels between the pressure chamber and the supply of engine oil, as a result of which the respective check valve loses its effect. The two return channels are opened and closed by an oil pressure-dependent control valve of the hydraulic control device, with exactly one return channel always being open and the other being closed. The actuator for switching the two return channels is controlled hydraulically by the supply pressure of the engine oil, the supply of engine oil being provided via corresponding hydraulic medium channels in the connecting rod and the bearing of the crankshaft pin in the second connecting rod eye. The outlet valve assigned to the respective return channel is opened or closed by the actuator, the outlet valve usually being reset automatically, for example by means of a return spring. The active adjustment of the connecting rod length is then carried out by deliberately emptying the pressure chamber filled with engine oil using the mass and gas forces acting on the connecting rod, whereby the other pressure chamber is supplied with engine oil and hydraulically blocked via the associated check valve.
    During operation, the connecting rod is constantly subjected to tensile and pressure loads, so that in the pressure chambers and the associated hydraulic lines up to the drain valve of the control valve, a swelling hydraulic medium pressure of over 300 bar is created. Furthermore, the function of the hydraulic control device for switching the two return channels requires not only small tolerances for the different components and highly effective seals to delimit the different pressure ranges, but also a secure supply and drainage of the pressure chambers with the pressurized engine oil via the control valve and corresponding hydraulic medium channels in the Connecting rod. This generally results in very high demands on the connecting rod components, including the components of the hydraulic control device, but also on the design and operation of the hydraulic control valve.
    It is therefore the object of the present invention to provide an improved construction and function of a generic length-adjustable connecting rod.
    / 26
    PP32168AT
    AVL List GmbH, iwis motorsysteme GmbH & Co. KG
    This object is achieved according to the invention in that the control slide has two control pressure areas that can be exposed to the hydraulic control pressure, the first control pressure area delimiting a first control pressure chamber in the control cylinder and the second control pressure area delimiting a second control pressure chamber in the control cylinder, and wherein the hydraulic control valve has a drainage channel that communicates with the at least one drain valve is in fluid communication and opens into the control cylinder between the first control pressure chamber and the second control pressure chamber. This structure of the hydraulic control valve enables, in addition to a simple structure, also a safe function and also better control of the hydraulic medium outflow, for example through an application-related dimensioning of the drainage channel. Via the drainage channel opening relatively centrally into the control cylinder, or the branching of the drainage channel from the control cylinder between the first and second control pressure chambers, in addition to the discharge of the hydraulic medium flowing out of an assigned pressure chamber of the length-adjustable connecting rod, drainage of the hydraulic medium from the low-pressure chamber also allows escaping hydraulic fluid from the first or second control pressure chamber when the control slide moves in the control cylinder. As a result, the requirements for the tolerances of the components of the hydraulic control valve and the sealing of the control slide with respect to the control cylinder can be kept low. For a structurally simple construction of the control spool, the control pressure surfaces, i.e. the effective surfaces of the control slide acted upon by the hydraulic control pressure are formed at the front ends of the control slide. Furthermore, the individual drainage channel provided in the middle between the first and second control pressure chambers makes it possible to dispense with further drainage channels for the control pressure chambers, reset mechanisms and associated drain valves of the hydraulic control valve.
    In an expedient embodiment, at least two drain valves which can be actuated by the control slide can be provided, the at least two drain valves being in fluid communication with the one drainage channel in order to discharge the hydraulic medium flowing out of the associated pressure chamber of the length-adjustable connecting rod. Since both drain valves are each coupled to the one drainage channel, there are no interactions between the outflow of the hydraulic medium from the respective pressure chambers and the supply of the pressure chambers with hydraulic medium, which in particular prevents the supply pressure from fluctuating. The provision of at least two drain valves which can be actuated by the hydraulically operated control slide enables a simple construction of the / 26
    PP32168AT
    AVL List GmbH, iwis motorsysteme GmbH & Co. KG hydraulic control valve and a smaller number of bores in the length-adjustable connecting rod to form the necessary oil supply and control pressure channels. The two drain valves can advantageously be actuated alternately by the control slide. This enables the hydraulic control device to function reliably with alternating filling of the assigned pressure chambers and the safe positioning of the connecting rod in the set length position.
    A preferred variant provides that the first control pressure area is smaller than the second control pressure area, the control pressure acting on the first control pressure area pressing the control slide along a control slide axis of the control slide into a first position and the control pressure acting on the second control pressure area pushing the control slide along the control slide axis presses into a second position, and wherein a return spring is provided which biases the spool along the spool axis in the direction of the first position. This construction makes it possible to provide two different switching positions in the hydraulic control device, and to provide an effective and fast-acting return mechanism for the same hydraulic control pressure via the bias of the return spring despite the different effective areas of the first and second control pressure areas. This increases the functional reliability of the hydraulic control device and at the same time the length-adjustable connecting rod. The control spool axis is to be understood as the central axis of the control spool in the axial direction and the control pressure surface is the surface of the control spool acted upon by the hydraulic control pressure, which generates a force which acts in the direction of the control spool axis, i.e. an effective effective area. The return spring used to pretension the control slide along the control slide axis in the direction of the first position can be easily adapted to different control pressures and arrangements of the control valve without having to change the entire construction of the hydraulic control device or even the length-adjustable connecting rod. The return spring can preferably be arranged radially to the control slide axis around the control slide, thereby reducing the installation space required for the control valve and at the same time also reducing the production outlay.
    A special embodiment provides that the drainage channel is connected to a non-pressurized drain channel in order to discharge the hydraulic medium flowing out of an associated pressure chamber of the length-adjustable connecting rod to the environment. In contrast to conventional length-adjustable connecting rods, for faster filling / 26
    PP32168AT
    AVL List GmbH, iwis motorsysteme GmbH & Co.KG of the pressure chambers, a drainage of the drain valves into the pressurized oil supply channel of the pressure chambers or the common control pressure lines, the provision of an unpressurized drain channel and its fluid connection to the drainage channel enables a complete drainage of the pressure chamber escaping hydraulic fluid to the environment. This enables continuous cooling or temperature control of the connecting rods with the engine oil of the piston engine to reduce the thermal load on the length-adjustable connecting rod, and in particular the components of the hydraulic control device, and to extend the operating times that can be achieved. Alternatively, the drainage channel can also be connected in a conventional manner to the oil supply channel in order to enable the pressure spaces to be filled as quickly as possible.
    In a further embodiment, the two drain valves are inclined to the spool axis, preferably perpendicular to the spool axis. This inclined arrangement of the drain valves allows a more compact design of the hydraulic control valve and thus overall smaller dimensions of the connecting rod with a corresponding reduction in mass. Furthermore, the inclined arrangement of the drain valves can minimize interfering influences on other components of the hydraulic control valve and negative influences of the inertia of the hydraulic medium in the hydraulic medium channels and the components of the hydraulic control device can be taken into account.
    For simple assembly of the hydraulic control valve and reliable functioning of the length-adjustable connecting rod, the control slide can have a switching contour, the two drain valves being able to be actuated alternately by means of the switching contour. In addition to a simple and alternate control of the drain valves, such a switching contour also enables a direct transmission of the axial movement of the control slide into a lifting movement of the drain valves. In this case, the switching contour can have circumferential depressions on the control slide, but also one-sided flats or projections in order to control the at least two drain valves in a coupled manner. For a simple and direct transmission of the movement of the control slide into a lifting movement of the valve bodies of the drain valves, the depressions or projections can be chamfered in order to enable slow opening and closing and a safe function of the drain valves.
    An embodiment of the length-adjustable connecting rod provides that two connecting rod parts are provided, the first connecting rod part the first connecting rod eye and the second connecting rod part / 26
    PP32168AT
    AVL List GmbH, iwis motorsysteme GmbH & Co. KG has the second connecting rod eye, and the first connecting rod part can be moved, preferably telescoped, relative to the second connecting rod part in the longitudinal direction of the connecting rod, in order to adjust the distance between the piston pin and the crankshaft journal. In contrast to connecting rods with eccentrics, two connecting rod parts that can be moved with respect to one another in the longitudinal direction of the connecting rod enable a stable construction and safe and permanent operation of the length-adjustable connecting rod. At least one cylinder-piston unit hydraulically connected to the hydraulic control device can be provided in order to move the first connecting rod part relative to the second connecting rod part, the first connecting rod part being connected to an adjusting piston of the cylinder-piston unit and the second connecting rod part being a cylinder bore the cylinder-piston unit. In addition to a very robust construction of the length-adjustable connecting rod, this also enables simple and inexpensive connecting rod parts, the adjusting piston of the first connecting rod part preferably being connected directly to the piston rod and the connecting rod head to the first connecting rod eye, and the second connecting rod part having a housing in which, in addition to the cylinder bore, also the hydraulic control device is provided.
    Furthermore, the invention relates to the use of a length-adjustable connecting rod with a hydraulic control valve in a piston engine, the hydraulic control valve of the control device having a control cylinder, a pressure-actuated control slide displaceably guided in the control cylinder and at least two drain valves, the control disc has two Control pressure areas which can be exposed to the hydraulic control pressure, the first control pressure area delimiting a first control pressure area and the second control pressure area delimiting a second control pressure area, and a drainage channel being provided which is in fluid communication with the at least two discharge valves and between the first control pressure area and the second control pressure area Control cylinder opens. The provision of two control pressure surfaces facilitates the safe functioning of the hydraulic control valve and, in addition to cost-effective manufacture and assembly of the control slide, also enables the longer adjustable connecting rod to be operated safely.
    In a further aspect, the invention relates to a piston engine with at least one engine cylinder, a reciprocating piston moving in the engine cylinder and at least one adjustable compression ratio in the engine cylinder, and with a length-adjustable connecting rod connected to the reciprocating piston according to the previously described embodiments. All reciprocating pistons of the piston engine are preferred with a / 26
    PP32168AT
    AVL List GmbH, iwis motorsysteme GmbH & Co. KG equipped such length-adjustable connecting rod and the control device of the length-adjustable connecting rod is connected to the engine oil hydraulics of the piston engine. The fuel saving of such a piston engine can be considerable if the compression ratio is set accordingly depending on the respective operating state. In addition to the number of bores and machining steps for the manufacture of the length-adjustable connecting rod, the provision of a centrally located drainage channel also reduces the risk of malfunctions. Accordingly, not only are the manufacturing costs reduced, but the operating times of the length-adjustable connecting rod are also increased.
    A non-limiting embodiment of the invention is explained in more detail below with reference to drawings. Show it:
    1 is a schematic view of a partially cut-out connecting rod according to the invention,
    Fig. 2 is a schematic view of the length-adjustable connecting rod from Fig. 1 in another switching position, and
    Fig. 3 is a schematic view of the length-adjustable connecting rod from Fig. 1 with a schematic representation of the hydraulic control device.
    The length-adjustable connecting rod 1 shown in the schematic view in FIG. 1 comprises two connecting rod parts 2, 3 that can be moved telescopically to one another. The lower connecting rod part 2, which is arranged at the bottom in the illustration of the length-adjustable connecting rod 1 in FIG. 1, has a large connecting rod eye 4, with which the length-adjustable connecting rod 1 is mounted on the crankshaft (not shown) of the piston engine. For this purpose, a bearing shell 5 is further arranged on the lower connecting rod part 2, which together with the lower region of the lower connecting rod 2, which is also designed like a bearing shell, forms the large connecting rod eye 4. The bearing shell 5 and the lower connecting rod part 2 are connected to one another by means of connecting rod screws (shown schematically as dashed lines). The upper connecting rod part 3 has a connecting rod head 6 with a small connecting rod eye 7, which receives the piston pin (not shown) of a reciprocating piston in the piston engine. The connecting rod head 6 is connected to the piston rod 8 and, via the piston rod 8, to the adjusting piston 9 of the adjusting device of the length-adjustable connecting rod 1, which is designed here as a cylinder-piston unit 10. The connecting rod head 6 is usually screwed or welded to the piston rod 8, while the adjusting piston 9 and the piston rod 8 can then be formed in one piece. This enables before / 26
    PP32168AT
    AVL List GmbH, iwis motorsysteme GmbH & Co. KG an assembly of the upper connecting rod part 3, the cylinder cover 15 of the cylinder-piston unit and the rod seal 16 on the piston rod 8 and the piston seals 17, 18 on the adjusting piston 9 can be arranged easily and without damage.
    The upper connecting rod part 3 is telescopically guided in the lower connecting rod part 2 via the adjusting piston 9 in order to adjust the distance between the piston pin of the reciprocating piston accommodated in the small connecting rod eye 7 and the crankshaft of the piston engine accommodated in the large connecting rod eye 4, so as to adjust the compression ratio of the piston engine to adapt to the respective operating state. This makes it possible to operate the piston engine in the partial load range with a higher compression ratio than under the full load range, thus increasing the efficiency of the engine. In the housing 11 of the lower connecting rod part 2, a cylinder 12 is formed in the upper region, which is introduced as a cylinder bore or cylinder sleeve into the housing 11 of the lower connecting rod part 2. In the cylinder 12, the adjusting piston 9 of the upper connecting rod part 3 is arranged to be movable in the longitudinal direction A of the connecting rod 1 in order to form the cylinder-piston unit 10 together with the cylinder 12 and the cylinder cover 15. The adjusting piston 9 is shown in FIG. 1 in a central position, in which the adjusting piston 9 divides the cylinder 12 into two pressure chambers 13 and 14. The piston rod 8 extends from the adjusting piston 9 through the upper pressure chamber 14 and the cylinder cover 15, which delimits the housing 11 and the cylinder 12 upwards. A rod seal 16 is provided on the cylinder cover 15, which surrounds the piston rod 8 and seals the upper pressure chamber 14 from the surroundings. The two piston seals 17, 18 arranged on the adjusting piston 9 seal the adjusting piston 9 from the cylinder 12 and thus also the pressure chambers 13, 14 from one another. The underside 19 of the cylinder cover 15 forms an upper stop, against which the adjusting piston 9 rests in the upper position, the long position of the length-adjustable connecting rod 1, while in the lower position (short position) of the length-adjustable connecting rod 1, the adjusting piston 9 on the Cylinder base 20 trained lower stop abuts.
    The hydraulic control device 21 for supplying the adjustment device formed by the cylinder-piston unit 10 is explained in more detail below with reference to the hydraulic circuit shown in FIG. 3. The two pressure chambers 13, 14 are each connected to the engine oil circuit of the piston engine via separate hydraulic medium lines 22, 23 and separate check valves 24, 25 and a common oil supply channel 26 which opens into the large connecting rod eye 4. If the length-adjustable connecting rod 1 is in the long position, there is no engine oil in the upper pressure chamber 14, while the lower / 26
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    AVL List GmbH, iwis motorsysteme GmbH & Co. KG
    Pressure chamber 13, however, is completely filled with engine oil. During operation, the connecting rod 1 is alternately subjected to tension and pressure due to the mass and gas forces. In the long position, the tensile force is absorbed by the mechanical contact of the adjusting piston 9 with the underside 19 of the cylinder cover 15. The length of the connecting rod 1 does not change. An acting pressure force is transmitted via the piston surface to the lower pressure chamber 13 filled with engine oil. Since the check valve 25 assigned to the lower pressure chamber 13 prevents the engine oil from flowing out, the pressure of the engine oil rises sharply and prevents a change in the connecting rod length. As a result, the length-adjustable connecting rod 1 is hydraulically locked in this direction of movement. In the short position of the length-adjustable connecting rod 1, the situation reverses. The lower pressure chamber 13 is completely empty and a pressure force is absorbed by the mechanical stop of the adjusting piston 9 on the cylinder base 20, while the upper pressure chamber 14 is filled with engine oil, so that a pulling force on the length-adjustable connecting rod 1 causes a pressure increase in the upper pressure chamber 14 and so that hydraulic locking causes.
    The connecting rod length of the length-adjustable connecting rod 1 shown here can be adjusted in two stages by emptying one of the two pressure chambers 13, 14 and filling the other pressure chambers 13, 14 with engine oil. For this purpose, one of the check valves 24, 25 is bridged by the hydraulic control device 21, so that the engine oil can flow out of the previously filled pressure chamber 13, 14. The respective check valve 24, 25 loses its effect. For this purpose, the hydraulic control device 21 comprises a control valve 34, which is shown here as a 3/2-way valve 27, the two switchable connections 30 of which are each connected via a throttle 28, 29 to one of the hydraulic medium lines 22, 23 and also to one of the pressure chambers 13, 14 are connected. The 3/2-way valve 27 is actuated by the pressure of the engine oil, which is supplied to the 3/2-way valve 27 via a control pressure line 31 connected to the oil supply channel 26. The engine oil supplied via the control pressure line 31 presses within the 3/2-way valve 27 onto a second control pressure surface 46 in order to change the switching positions of the connections 30. The 3/2-way valve 27 is reset by a combined action of a return spring 39 and the pressurized engine oil which is supplied via a control pressure line 31 'and acts on a first control pressure surface 46'. The two switchable connections 30 of the 3/2-way valve 27 are connected via a single, common drainage channel 32 to an overpressure-free drainage channel 33, which delivers the engine oil discharged from the pressure chambers 13, 14 directly to the surroundings of the length-adjustable connecting rod 1. 3/26
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    Preferred position of the 3/2-way valve 27, the upper pressure chamber 14 is open. To fill the respective other pressure chamber 14, 13, new engine oil is supplied via the large connecting rod eye 4, the oil supply channel 26 and the associated check valve 24, 25. Alternatively, the drainage channel 32 can also be connected to the oil supply channel 26, so that engine oil which has been removed is again available for filling the other pressure chamber 13, 14.
    In the 3/2-way valve 27, one of the switchable connections 30 is opened, so that the associated pressure chamber 13, 14 is emptied, while the other connection 30 is closed. In the event of a change in the switching position of the 3/2-way valve 27, by the application of a higher control pressure via the control pressure line 31 or by a reset with a decreasing control pressure, i.e. A combination of the effect of the reduced control pressure on the first control pressure surface 46 ′ and the pretensioning of the return spring 39 closes the previously opened port 30 and opens the previously closed port 30. As a result, the high-pressure engine oil flows from the previously filled pressure chamber 13, 14 via the respective hydraulic medium line 22, 23 and the associated throttle 28, 29 through the opened connection 30 of the 3/2-way valve 27 and the drainage channel 32 and the drainage channel 33 to the environment. At the same time, the mass and gas forces acting in a piston engine during the lifting movement of the connecting rod 1 create a suction effect in the previously empty pressure chamber 14, 13, through which the associated check valve 24, 25 opens, so that the previously empty pressure chamber 14, 13 fills with engine oil. With increasing emptying of the previously filled pressure chamber 14, 13 via the opened connection 30, engine oil is increasingly supplied to the other pressure chamber 14, 13, as a result of which the length of the connecting rod 1 changes. Depending on the design of the length-adjustable connecting rod 1 and the hydraulic control device 21 and the operating state of the piston engine, several strokes of the connecting rod 1 may be required until the pressure chamber 14, 13 blocked by the hydraulic control device 21 is completely filled with engine oil and the other open pressure chamber 13, 14 is completely emptied and the desired change in length of the connecting rod 1 is achieved.
    The hydraulic control device 21 shown in FIG. 1 has a hydraulic control valve 34 designed as a slide valve with a control cylinder 36 and a cylindrical control slide 35 arranged displaceably in the control cylinder 36.
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    1 and 2, the axis of movement of the control slide 35 is shown to run essentially normal to the longitudinal direction A of the connecting rod 1 and normal to the longitudinal axis of the crankshaft (not shown). Accordingly, the control slide 35 moves in a plane that runs through the longitudinal direction A of the connecting rod 1 and normal to the longitudinal axis of the crankshaft, that is to say essentially lies in the leaf plane of FIGS. 1 and 2. It is pointed out that different directions of movement of the control slide 35 are also possible, e.g. in the plane described, but at an oblique angle to the longitudinal axis A of the connecting rod, in a direction parallel to the longitudinal axis of the crankshaft or obliquely to the longitudinal axis A of the connecting rod 1. For reasons of clarity, these directions are in the figures not shown.
    The control slide 35 has two control pistons 37, 37 'each arranged on the end face, which together with the control cylinder 36 form control pressure spaces 38, 38' arranged on the side of the control slide 35. The control pressure spaces 38, 38 'are each supplied by a control pressure line 31, 31' from the oil supply channel 26 with hydraulic fluid under control pressure. A switching contour 40 for opening and closing the drain valves 41, 42 is formed between the two control pistons 37, 37 'arranged on the end face, which are sealed or guided with only a small leakage gap with respect to the control cylinder 36. In the transition area to the control pistons 37, 37 ', the switching contour is chamfered in order to lift the respective valve body 43 out of the valve seat 44 of the first and second drain valve 41, 42 evenly and with as little effort as possible and to open the respective drain valve 41, 42. To the switching contour 40 of the control spool 35 around the return spring 39 is further arranged, which is supported on a step in the control cylinder 36 and presses the control spool 35 together with the control pressure of the hydraulic medium prevailing in the first control pressure chamber 38 'in the direction of the second control pressure chamber 38, around that open first drain valve 41 after second drain valve 42 closes. Between the control contour 40 of the control spool 35 and the control cylinder 36, a low-pressure chamber 45 is formed, which is connected to the drainage channel 32 and a pressureless discharge channel 33 in order to release hydraulic fluid flowing out of the lower pressure chamber 13 via the opened second discharge valve 42 to the surroundings of the length-adjustable connecting rod 1 to dissipate. Alternatively, the drainage channel 32 can also be connected to the oil supply channel 26 in order to provide the outflowing engine oil directly for filling the upper pressure chamber 14.
    / 26
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    AVL List GmbH, iwis motorsysteme GmbH & Co. KG
    In the position of the hydraulic control valve 34 shown in FIG. 1, a high hydraulic control pressure which acts on the second control pressure surface 46 of the second control piston 37 is present in the control pressure chamber 38 via the oil supply channel 26 and the control pressure line 31. The force acting on the second control pressure surface 46 from the hydraulic medium in the second control pressure space 38 is greater than the sum of the force of the hydraulic medium under high control pressure acting on the first control pressure surface 46 'of the first control piston 37' in the first control pressure space 38 ' Return spring 39 on the control slide 35 biasing force. Therefore, the second control piston 37 presses the valve body 43 of the second drain valve 42 out of its valve seat 44. Through this opened second drain valve 42, the hydraulic medium flows from the lower pressure chamber 13 via the hydraulic medium line 23 into the drain valve 42 and from there via the low pressure chamber 45, the drainage channel 32 and the pressureless drain channel 33 directly into the vicinity of the length-adjustable connecting rod 1. At the same time, the first drain valve 41 is closed, so that the upper pressure chamber 14 is hydraulically locked and the motor oil flowing into the upper pressure chamber 14 via the oil supply channel 26 and the check valve 24 Adjusting piston 9 of the cylinder-piston unit 10 presses in the direction of the cylinder base 20 until the short position of the length-adjustable connecting rod 1 is reached. As shown in FIG. 3, the connections 30, 30 'of the hydraulic medium lines 22, 23 on the drain valves 41, 42 can be throttled in order to prevent the engine oil from flowing out of the pressure chambers 13, 14 too quickly and in an uncontrolled manner.
    2 shows a second switching position of the hydraulic control valve 34 at a low hydraulic control pressure. The decreasing control pressure in the first control pressure chamber 38 ′ presses the control slide 35 together with the pretension of the return spring 39 in the direction of the second control pressure chamber 38. The movement of the control slide 35 at the chamfered transition to the first control piston 37 ′ pushes the valve body 43 of the first drain valve 41 out pressed its valve seat 44 and the first drain valve 41 is opened. The second drain valve 42 closes beforehand since the drain valve 42 is brought out of contact with the second control piston 37. The first drain valve 41 and the second drain valve 42 are arranged radially to the spool 35, preferably perpendicular to the spool axis. Via the opened first drain valve 41, hydraulic fluid flows from the upper pressure chamber 14 via the hydraulic medium line 22 into the drain valve 41 and from there via the low pressure chamber 45, the drainage channel 32 and the pressureless drain channel 33 directly into the vicinity of the length-adjustable connecting rod 1 at the same time the other, lower pressure chamber 13 via the oil supply channel 26, the check valve 25/26
    PP32168AT
    AVL List GmbH, iwis motorsysteme GmbH & Co. KG and the hydraulic medium line 23 with engine oil until the lower pressure chamber 13 is completely filled with engine oil and the length-adjustable connecting rod 1 is in the long position.
    / 26
    PP32168AT
    AVL List GmbH, iwis motorsysteme GmbH & Co. KG
    List of reference symbols length-adjustable connecting rod lower connecting rod part upper connecting rod part
    connecting rod
    bearing shell
    small end
    connecting rod
    piston rod
    adjusting piston
    Cylinder-piston unit
    casing
    cylinder
    pressure chamber
    pressure chamber
    cylinder cover
    rod seal
    piston seal
    piston seal
    bottom
    Cylinder bottom hydraulic control device
    Hydraulic medium line
    Hydraulic medium line
    check valve
    Check valve / 26
    PP32168AT
    AVL List GmbH, iwis motorsysteme GmbH & Co. KG
    Oil supply channel
    3/2-way valve
    throttle
    throttle
    connections
    Control pressure line
    drainage channel
    spillway
    spool valve
    spool
    control cylinder
    spool
    Control pressure chamber
    Return spring
    switching contour
    drain valve
    drain valve
    valve body
    Valve seat low pressure chamber control pressure area
    Longitudinal direction / 26
    PP32168AT
    AVL List GmbH, iwis motorsysteme GmbH & Co. KG
    权利要求:
    Claims (10)
    [1]
    Expectations
    1. Length-adjustable connecting rod (1) for a piston engine, the connecting rod (1) having a first connecting rod eye (7) for receiving a piston pin and a second connecting rod eye (4) for receiving a crankshaft pin, the distance between the piston pin and the crankshaft pin in The longitudinal direction (A) of the connecting rod (1) can be adjusted by means of a control device (21) with a hydraulic control valve (34) and the hydraulic control valve (34) is a control cylinder (36), which is displaceably guided in the control cylinder (36) and has a hydraulic control pressure Actuated control slide (35) and at least one drain valve (41, 42) actuable by the control slide (35), characterized in that the control slide (35) has two control pressure surfaces (46, 46 ') which can be exposed to the hydraulic control pressure, the first control pressure surface ( 46 ') a first control pressure chamber (38') in the control cylinder (36) and the second control pressure surface (4 6) delimits a second control pressure chamber (38) in the control cylinder (36), and wherein the hydraulic control valve (34) has a drainage channel (32) which is in fluid communication with the at least one drain valve (41, 42) and between the first control pressure chamber ( 38 ') and the second control pressure chamber (38) opens into the control cylinder (36).
    [2]
    2. Length-adjustable connecting rod (1) according to claim 1, characterized in that at least two drain valves (41, 42) which can be actuated by the control slide (35) are provided, the at least two drain valves (41, 42) being in fluid communication with the drainage channel (32) stand in order to discharge the hydraulic medium flowing out of an associated pressure chamber (13, 14) of the length-adjustable connecting rod (1), wherein preferably the two drain valves (41, 42) can be actuated alternately by the control slide (35).
    [3]
    3. Length-adjustable connecting rod (1) according to claim 1 or 2, characterized in that the first control pressure surface (46 ') is smaller than the second control pressure surface (46), the control pressure acting on the first control pressure surface (46') the control slide (35 ) along a control spool axis of the control spool (35) in a first position and the one acting on the second control pressure surface (46)
    18/26
    PP32168AT
    AVL List GmbH, iwis motorsysteme GmbH & Co. KG
    Control pressure presses the spool (35) along the spool axis into a second position, and a return spring (39) is provided which biases the spool (35) along the spool axis in the direction of the first position.
    [4]
    4. Length-adjustable connecting rod (1) according to one of claims 1 to 3, characterized in that the drainage channel (32) is connected to a non-pressurized drain channel (33) in order from an associated pressure chamber (13, 14) of the length-adjustable connecting rod (1 ) to release hydraulic fluid that flows out into the environment.
    [5]
    5. Length-adjustable connecting rod (1) according to one of claims 2 to 4, characterized in that the two drain valves (41,42) are arranged inclined to the spool axis, preferably perpendicular to the spool axis.
    [6]
    6. Length-adjustable connecting rod (1) according to one of claims 3 to 5, characterized in that the control slide (35) has a switching contour (40), wherein the two drain valves (41,42) can be actuated alternately by means of the switching contour (40).
    [7]
    7. Length-adjustable connecting rod (1) according to one of claims 1 to 6, characterized in that two connecting rod parts (2, 3) are provided, the first connecting rod part (3), the first connecting rod eye (7) and the second connecting rod part (2) has second connecting rod eye (4) and the first connecting rod part (3) for adjusting the distance between the piston pin and the crankshaft journal relative to the second connecting rod part (2) in the longitudinal direction (A) of the connecting rod (1) is movable, preferably telescopically.
    [8]
    8. Length-adjustable connecting rod (1) according to claim 7, characterized in that at least one with the hydraulic control device (21) hydraulically connected cylinder-piston unit (10) is provided to the first connecting rod part (3) relative to the second connecting rod part (2 ) to move, the first connecting rod part (3) being connected to an adjusting piston (9) of the cylinder-piston unit (10) and the second connecting rod part (2) having a cylinder bore (12) of the cylinder-piston unit (10) ,
    [9]
    9. Use of a length-adjustable connecting rod (1) with a hydraulic control valve (34) in a piston engine, the hydraulic control valve (34) of the control device (21) being a control cylinder (36), one in the control cylinder (36)
    19/26
    PP32168AT
    AVL List GmbH, iwis motorsysteme GmbH & Co. KG guided, pressurizable control spool (35), two control pressure chambers (38, 38 ') and at least two drain valves (41, 42), the control spool (35) has two the hydraulic control pressure removable control pressure surfaces (46, 46 '), the first control pressure surface (46') delimiting the first control pressure chamber (38 ') and the second control pressure surface (46) the second control pressure chamber (38), and a drainage channel (32) being provided is in fluid communication with the at least two drain valves (41, 42) and opens into the control cylinder (36) between the first control pressure chamber (38 ') and the second control pressure chamber (38).
    [10]
    10. Piston engine with at least one engine cylinder, a reciprocating piston moving in the engine cylinder and at least one adjustable compression ratio in the engine cylinder, and with a length-adjustable connecting rod (1) connected to the reciprocating piston according to one of claims 1 to 8.
    20/26
    PP32168AT
    AVL List GmbH iwis motorsysteme GmbH & Co. KG
    1.3

    21/26
    PP32168AT
    AVL List GmbH iwis motorsysteme GmbH & Co. KG
    2.3

    22/26
    PP32168AT
    AVL List GmbH iwis motorsysteme GmbH & Co. KG

    23/26
    PP32168AT
    AVL List GmbH, iwis motorsysteme GmbH & Co. KG
    Expectations
    1. Length-adjustable connecting rod (1) for a piston engine, the connecting rod (1) having a first connecting rod eye (7) for receiving a piston pin and a second connecting rod eye (4) for receiving a crankshaft pin, the distance between the piston pin and the crankshaft pin in The longitudinal direction (A) of the connecting rod (1) can be adjusted by means of a control device (21) with a hydraulic control valve (34) and the hydraulic control valve (34) is a control cylinder (36), which is displaceably guided in the control cylinder (36) and has a hydraulic control pressure Actuating control slide (35) and at least one drain valve (41, 42) which can be actuated by the control slide (35), the control slide (35) having two control pressure surfaces (46, 46 ') which can be exposed to the hydraulic control pressure, the first control pressure surface (46') a first control pressure chamber (38 ') in the control cylinder (36) and the second control pressure surface (46) a second control limited pressure space (38) in the control cylinder (36), and wherein the hydraulic control valve (34) has a drainage channel (32) which is in fluid communication with the at least one drain valve (41, 42) and between the first control pressure space (38 ') and the second control pressure chamber (38) opens into the control cylinder (36), characterized in that the first control pressure area (46 ') is smaller than the second control pressure area (46), the control pressure acting on the first control pressure area (46') controlling the spool ( 35) along a spool axis of the spool (35) in a first position and the control pressure acting on the second control pressure surface (46) presses the spool (35) along the spool axis into a second position, and a return spring (39) is provided biases the spool (35) along the spool axis toward the first position.
    2. Length-adjustable connecting rod (1) according to claim 1, characterized in that at least two drain valves (41, 42) which can be actuated by the control slide (35) are provided, the at least two drain valves (41, 42) being in fluid communication with the drainage channel (32) stand in order to discharge the hydraulic medium flowing out of an associated pressure chamber (13, 14) of the length-adjustable connecting rod (1), wherein preferably the two drain valves (41, 42) can be actuated alternately by the control slide (35).
    24/26 ________________________________________ (LAST CLAIMS)
    PP32168AT
    AVL List GmbH, iwis motorsysteme GmbH & Co. KG
    3. Length-adjustable connecting rod (1) according to claim 1 or 2, characterized in that the drainage channel (32) is connected to a non-pressurized drain channel (33) to flow out of an associated pressure chamber (13, 14) of the length-adjustable connecting rod (1) Deliver hydraulic fluid to the environment.
    4. Length-adjustable connecting rod (1) according to claim 2 or 3, characterized in that the two drain valves (41,42) are arranged inclined to the spool axis, preferably perpendicular to the spool axis.
    5. Length-adjustable connecting rod (1) according to one of claims 2 to 4, characterized in that the control slide (35) has a switching contour (40), wherein the two drain valves (41,42) can be actuated alternately by means of the switching contour (40).
    6. Length-adjustable connecting rod (1) according to one of claims 1 to 5, characterized in that two connecting rod parts (2, 3) are provided, the first connecting rod part (3), the first connecting rod eye (7) and the second connecting rod part (2) has second connecting rod eye (4) and the first connecting rod part (3) for adjusting the distance between the piston pin and the crankshaft journal relative to the second connecting rod part (2) in the longitudinal direction (A) of the connecting rod (1) is movable, preferably telescopically.
    7. Length-adjustable connecting rod (1) according to claim 6, characterized in that at least one with the hydraulic control device (21) hydraulically connected cylinder-piston unit (10) is provided to the first connecting rod part (3) relative to the second connecting rod part (2 ) to move, the first connecting rod part (3) being connected to an adjusting piston (9) of the cylinder-piston unit (10) and the second connecting rod part (2) having a cylinder bore (12) of the cylinder-piston unit (10) ,
    8. Use of a length-adjustable connecting rod (1) with a hydraulic control valve (34) in a piston engine, the hydraulic control valve (34) of the control device (21) a control cylinder (36), one in the control cylinder (36) slidably guided with pressure has actable control slide (35), two control pressure chambers (38, 38 ') and at least two drain valves (41, 42), the control slide (35) has two control pressure surfaces (46, 46') which can be exposed to the hydraulic control pressure, whereby
    25/26 (LAST CLAIMS)
    PP32168AT
    AVL List GmbH, iwis motorsysteme GmbH & Co. KG the first control pressure area (46 ') delimits the first control pressure area (38') and the second control pressure area (46) delimits the second control pressure area (38), and a drainage channel (32) is provided is in fluid communication with the at least two drain valves (41, 42) and opens into the control cylinder (36) between the first control pressure chamber (38 ') and the second control pressure chamber (38), the first control pressure area (46') being smaller than the second control pressure area (46) and the control pressure acting on the first control pressure surface (46 ') presses the control spool (35) into a first position along a control spool axis of the control spool (35) and the control pressure acting on the second control pressure surface (46) pushes the control spool (35) presses along the spool axis into a second position, and a return spring (39) is provided which directs the spool (35) along the spool axis preloaded the first position.
    9. piston engine with at least one engine cylinder, a reciprocating piston moving in the engine cylinder and at least one adjustable compression ratio in the engine cylinder, and with a length-adjustable connecting rod (1) connected to the reciprocating piston according to one of claims 1 to 7.
    26/26 [LAST CLAIMS]
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    同族专利:
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    AT521269B1|2019-12-15|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    EP1426584A1|2002-11-27|2004-06-09|FEV Motorentechnik GmbH|Connecting rod for reciprocating piston machine with variable adjustable compression ratio|
    DE102005055199A1|2005-11-19|2007-05-24|Fev Motorentechnik Gmbh|Reciprocating internal combustion engine e.g. commercial vehicle diesel engine, has eccentric tappet moved along length of piston rod, where changeable resistor affects adjustment movement of tappet and effects adjustment movement of tappet|
    WO2013092364A1|2011-12-23|2013-06-27|Avl List Gmbh|Connecting rod for a reciprocating-piston engine|
    WO2015055582A2|2013-10-18|2015-04-23|Avl List Gmbh|Length-adjustable connecting rod|
    DE102017104391A1|2017-03-02|2018-09-06|Schaeffler Technologies AG & Co. KG|Switching device for controlling an adjusting device and connecting rod for a reciprocating internal combustion engine with such a switching device|
    CN112502829B|2020-02-24|2022-02-01|长城汽车股份有限公司|Method for assembling variable compression ratio driving structure|
    法律状态:
    优先权:
    申请号 | 申请日 | 专利标题
    ATA50869/2018A|AT521269B1|2018-10-08|2018-10-08|Hydraulic control valve for a length-adjustable connecting rod with two control pressure chambers|ATA50869/2018A| AT521269B1|2018-10-08|2018-10-08|Hydraulic control valve for a length-adjustable connecting rod with two control pressure chambers|
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