DE102012014917A1 - Reciprocating piston engine for motor vehicle, has pressure pulse generator provided between crankshaft and oil reservoir, such that pressure pulse generated by pulse generator is controlled over oil supply control of driving mechanism - Google Patents

Abstract

The engine has driving mechanism for driving adjusting device to adjust variable compression ratio of engine. An oil supply system (47) has oil connection (50) provided between oil reservoir (48) and pressure generator of driving mechanism, while oil connection (51) is provided between pressure generator and oil supply line of driving mechanism. A common switch is provided to actuate adjusting devices of engine. A pressure pulse generator (52) is provided between crankshaft (53) and reservoir, such that generated pressure pulse is controlled over oil supply control of driving mechanism. An independent claim is included for Method for controlling several respective driving mechanisms.

Description

• – zumindest einer Verstelleinrichtung unter Nutzung von Triebwerkskräften der Hubkolbenmaschine zum Verstellen eines einstellbar veränderbaren Verdichtungsverhältnisses aufweist,
• – einen Ansteuermechanismus zum Ansteuern der Verstelleinrichtung hat, wobei der Ansteuermechanismus ausschließlich an einem Pleuel oder Kolben angeordnet ist und mindestens ein bewegliches Element, eine einzige Ölzufuhr, mindestens ein veränderbares Volumen zum Befüllen und Entleeren von Öl und mindestens eine Ölleitung hat, und
• – ein Ölversorgungssystem hat, welches ein Ölreservoir, einen Druckerzeuger, eine Ölverbindung zwischen dem Ölreservoir und dem Druckerzeuger und eine Ölverbindung zwischen dem Druckerzeuger und der Ölzufuhr des Ansteuermechanismus aufweist.

The invention relates to a reciprocating engine, which:

• - Has at least one adjusting device using engine forces of the reciprocating engine for adjusting an adjustable variable compression ratio,
• - Has a drive mechanism for driving the adjusting device, wherein the drive mechanism is arranged exclusively on a connecting rod or piston and has at least one movable element, a single oil supply, at least one variable volume for filling and emptying of oil and at least one oil line, and
• - Has an oil supply system having an oil reservoir, a pressure generator, an oil connection between the oil reservoir and the pressure generator and an oil connection between the pressure generator and the oil supply of the drive mechanism.

Furthermore, a method for operating a reciprocating engine is proposed.

Hydraulic drive mechanisms for switching a variable compression ratio are prior art in reciprocating engines. Out US Pat. No. 7,434,548 B2 For example, a hydraulic drive mechanism for adjusting the compression ratio of a reciprocating engine, which is controlled by an oil pump and a switching valve. Depending on the compression ratio to be set, an increased oil pressure for the drive mechanism can be provided via the oil pump and the switching valve. Thus, during operation of the reciprocating engine at a low compression ratio, no increased oil pressure from the oil pump for the drive mechanism is provided. During operation of the reciprocating engine at a higher compression ratio of the oil pump, an increased oil pressure is provided.

The object of the present invention is to improve the hydraulic actuation of an adjustable variable compression ratio of a reciprocating engine.

This object is achieved with a reciprocating engine having the features of claim 1 and with a method having the features of claim 12. Further advantageous embodiments and features will become apparent from the respective dependent claims and the description below. In particular, one or more features of the independent and dependent claims may be supplemented and / or replaced by one or more features of the description. Also, one or more features of different embodiments of the invention may be linked to further embodiments of the invention.

It is proposed a reciprocating engine, which has at least one adjusting device using engine forces of the reciprocating engine for adjusting an adjustable variable compression ratio. Furthermore, a drive mechanism for controlling the adjusting device is provided, which is arranged exclusively on a connecting rod or piston and has at least one movable element. The drive mechanism comprises a single oil supply, at least one variable volume for filling and draining oil and at least one oil line. The reciprocating engine also includes an oil supply system having an oil reservoir and a pressure generator. The oil supply system has an oil connection between the oil reservoir and the pressure generator and an oil connection between the pressure generator and the oil supply of the drive mechanism. The respective drive mechanism of at least two, in particular of all respective adjusting devices of the reciprocating engine are simultaneously actuated by a common circuit or switch.

To switch less than all the drive mechanisms simultaneously, for example, is set up when a V or a W-motor or a boxer engine are used. Even with a possible cylinder deactivation, there is the possibility of splitting the effective connecting rod lengths to be changed. Preferably, however, all effective lengths are simultaneously actuated by the same common circuit or switch.

Preferably, the pressure generator is designed as a pressure pulse generator and interposed between the crankshaft and the oil reservoir. The drive mechanism is controlled via a pressure pulse generated by the pressure pulse generator via the oil supply of the drive mechanism.

Another embodiment provides a common switch, in particular in the form of a mechanically acting switch or circuit, which is arranged on the reciprocating engine. For example, a mechanical actuator can act on the respective individual control mechanism on each connecting rod simultaneously.

An adjustable variable compression ratio can be achieved in various ways. Thus, for example, a connecting rod with a variable effective length or a height-adjustable piston head can be provided for setting a variable compression ratio. Under an effective length of the connecting rod is the To understand the shortest possible distance between a horizontal line of symmetry of the piston pin of the piston to a horizontal line of symmetry of a crank pin of the crankshaft. To adjust the effective length of the connecting rod or to adjust the height of the piston head, an adjusting device is preferably provided with at least two parts, which are arranged on the connecting rod or on the piston.

According to one embodiment, it is provided that two parts are firmly connected to each other at a constant compression ratio, d. H. a connection between the two parts is effective. Here, a fixed connection means that it is able to transfer a force from one part to the other part. On the other hand, if the compression ratio changes, the two parts are not firmly connected, i. H. the connection is resolved or ineffective. The connection between the first and the second part is for example rotatable, for example in the form of a rotatable eccentric with a circular outer surface as the first part and a circular recording of the eccentric as a second part. The connection is non-destructive solvable. The connection comprises at least one connecting element, preferably a movable pin. Advantageously, the pin is slidably mounted on a guide element of the first part.

A further embodiment provides that the pin of the first part is in effective connection in contact with the second part, preferably positioned in a hole or in a recess of the second part. The operative connection has via the connecting element a contact between the first and second part for generating a contact force between the first and the second part during operation of the reciprocating piston engine. on. The contact force generated by the active connection has a sufficient counterforce to the existing gas and inertial forces during operation of the reciprocating engine to avoid a relative acceleration of the two parts to each other.

When the connection between the first and the second part is released, preferably the pin of the first part is not in contact with the second part. For example, the contact force which is no longer present due to the dissolved connection has no counterforce to the gas and mass forces present during operation of the reciprocating piston engine in order to avoid a relative acceleration of the two parts relative to one another. Due to the dissolved connection then the two parts are mutually movable. Due to the dissolved connection between the two parts of the adjusting device, the two parts of the adjusting device, in particular due to the existing gas and inertial forces in the operation of the reciprocating piston on a relative Bescheunigung each other. The relative movement of the two parts to each other, for example, causes a change in the effective length of the connecting rod and / or an adjustment of the height of the piston head relative to the piston, wherein the compression ratio of the reciprocating engine is changed.

To release the adjusting device, for example, the drive mechanism is provided. The size ratio between the length of a connecting rod of the reciprocating engine and a maximum length, width or height of the driving mechanism is in a range of five to one to ten to one, in another embodiment in a range of ten to one to fifty to one, in FIG another embodiment in a range of fifty to one to one hundred to one and in another embodiment in a range of one hundred to one to one thousand to one. The drive mechanism is preferably arranged on a connecting rod or piston. A control part of the drive mechanism is connected to a part of the adjusting device, preferably directly to the connecting element of the adjusting device, which connects the first part with the second part of the adjusting device. In another embodiment, the control part of the drive mechanism is connected to a hydraulic valve of the adjustment mechanism or controls a hydraulic valve via a mechanical connection.

The control part of the drive mechanism is preferably a rod, a shaft, a shaft with a thread, a shaft with a gear, a rod, a gear, a rack, a spring, a latching element and / or a lever. One embodiment provides a pushable rack driven by the drive mechanism which is in contact with a gear from a shaft. On the shaft, a lever is attached, which is in contact with a spring. The spring is mechanically connected to a connecting element, preferably a pin, of the adjusting device.

Furthermore, a movable element of the drive mechanism for driving the control part of the drive mechanism is provided. The movable element is controlled by the gas or mass forces of the reciprocating engine and / or by a hydraulic device. Furthermore, the drive mechanism preferably has only one oil line and only a single oil supply. The drive mechanism has no component or portion in common with the crankshaft. The oil supply of the drive mechanism is connected, for example via an oil line of the crankshaft with an oil circuit. Preferably, the Ansteuermechanismus on at least one variable volume for filling and emptying of oil. In a further development, the drive mechanism has several, via a connected to hydraulic channel, oil-containing volumes, wherein one or more volumes are variable. For example, the drive mechanism provides one or more movable components for connecting and disconnecting the volumes. The filling and emptying of the individual volumes is controlled, for example, by the interaction of the individual components. For this purpose, one or more volumes are indirectly or directly connected to the oil supply of the drive mechanism.

The oil supply of the drive mechanism is preferably connected to an oil supply system of the reciprocating engine. The oil supply system comprises an oil reservoir, which is connected via an oil line with a pressure generator. In addition, for example, in the oil supply system, an oil connection from the pressure generator via a crankshaft of the reciprocating engine for oil supply of the drive mechanism is provided.

It is proposed that the pressure generator is designed as a pressure pulse generator. The pressure pulses generated by the pressure pulse generator are limited in time to a range sufficient for switching, preferably of the order of ten to fifty cycles of the reciprocating engine. Preferably, the pressure pulse is maintained just until the switching is completed. For example, this may be completed by means of a single, two or fewer further pressure pulses. The duration and / or the amount of the pressure pulses are adapted to the geometry, preferably to the length of the oil lines and the size of the oil-containing volume in the drive mechanism. Preferably, the amounts of the pressure pulses reach a value of three to four bar above the engine oil pressure in the engine operation at the time of adjusting the compression ratio.

For example, a transmission of the pressure pulse from the pressure pulse generator via a crankshaft of the reciprocating engine to the oil supply of the drive mechanism is provided within an oil supply system.

According to one embodiment, the drive mechanism, which is located in the connecting rod or in the piston or arranged on the connecting rod or piston, controlled by a pressure pulse, wherein the pressure pulse is generated by the pressure pulse generator and passes from the pressure pulse generator via oil lines to the oil supply of the drive mechanism. By means of converting a pressure pulse or a chronological sequence of pressure pulses into one or more mechanical control signals for controlling the adjusting device, starting from a first compression ratio to a second, different from the first compression ratio of the reciprocating engine.

After adjustment of the compression ratio, generation of further pressure pulses or maintenance of such high pressure by the pressure generator to maintain the compression ratio is not necessary. In contrast to the prior art, the print pulse generator provides a sufficiently high, short term pressure pulse so that the pressure generator does not need to supply a higher pressure all the time during operation at a constant compression ratio. Rather, the pressure generator can keep a pressure level constant during the switching when a pressure generator to the separate pressure generator is provided.

In this case, in a first embodiment of the present invention, the oil lines of the oil supply system are separated from the lubricating oil supply system of the reciprocating piston engine. The control mechanism is controlled by means of at least one, possibly by means of a plurality of short successive pressure pulses with preferably the same or at least approximately the same pressure level. However, the pressure level of a pressure pulse is also variable according to a development.

By separating the oil supply system of the Anteuermechanismus from Schmielöverrsorgungssystems the reciprocating engine, according to an embodiment, an influence of the pressure fluctuations in the lubricating oil supply system to the pressure level of the control mechanism led to the pressure pulses at least reduced, preferably avoided.

The pressure generator of the oil supply system of the drive mechanism receives the oil from an oil reservoir. According to one embodiment, this oil reservoir is connected to the oil pan of the lubricating oil supply system of the reciprocating engine. If the drive mechanism is supplied with a different oil than, for example, the crankshaft bearings or other parts of the reciprocating piston engine, the oil reservoir according to another embodiment is separated from the lubricating oil supply system of the reciprocating engine.

Preferably, the drive mechanism is supplied with a different oil than the lubricating oil supply system of the reciprocating engine. For example, the oil supply oil of the drive mechanism has a higher purity, another composition of additives, or a higher viscosity at a temperature of 90 ° C than the oil of the lubricating oil supply system of the reciprocating engine.

The pressure generator, which is designed as a pressure pulse generator generates, for example, for driving the drive mechanism, a pressure pulse which is preferably three to four bar above the average over a working cycle oil pressure of the reciprocating engine at the respective operating point and about as long as the driving mechanism for triggering the adjustment for Switching from a first compression ratio to a second compression ratio of the reciprocating engine required. The pressure pulse generator according to an embodiment comprises at least one oil storage cylinder with a piston, wherein the oil storage cylinder can store at least the amount of oil required for a switching operation, a valve and a means for driving the piston to build up within the piston an oil pressure sufficient to drive the drive mechanism , The anti-theft agent may be an oil pump, an electric motor, a charged spring or a pneumatic switching unit.

In a preferred embodiment, the oil supply system of the drive mechanism is connected to a lubricating oil supply system of the reciprocating engine, wherein the lubricating oil supply system comprises at least one check valve in an oil line between a crankshaft bearing and an engine oil pump.

The connection of the oil supply system of the drive mechanism with the lubricating oil supply system of the reciprocating engine has a particular effect on a simpler design of the crankshaft. The crankshaft preferably has no additional oil lines for the oil supply system of the drive mechanism in addition to the oil supply lines of the lubricating oil supply system.

It is arranged according to an embodiment, at least one check valve in an oil line between the pressure pulse generator and the engine oil pump of the oil lubrication circuit. Preferably, a check valve is arranged in all oil lines between the pressure pulse generator and the engine oil pump.

In a further preferred embodiment it is provided that the drive mechanism has at least one movable element. The movable element has a first position and a second position. The first position is associated with a first compression ratio and the second position with a second, different from the first compression ratio compression ratio. A toggling of the element is controlled by successive rectified pressure pulses generated by the pressure pulse generator.

Preferably, in the first and in the second position of the movable element, a movement of the element is blocked by a lock. The locking is effected for example via a second movable element. The second movable element causes a locking of the first movable element in a holding position and releases a movement of the first movable element in a release position. A movement of the second movable element is effected in one embodiment via a pressure pulse. The pressure pulse passes through the single oil supply in the drive mechanism to the second movable member and pushes the second movable member from the holding position to the release position. Preferably, the second member biases a spring as it moves from the hold position to the release position. When the movement of the first movable member is released, a control edge of the first member prevents movement of the second member from the release position to the holding position and the spring is cocked. When the first element reaches the first or second position, the control edge of the first element releases a movement of the second element from the release position to the stop position. The movement of the second element from the second position to the first position is driven by a force acting on the second element from the tensioned spring. When the second element reaches the first position, the movement of the first element is arrested.

In a further embodiment, a locking mechanism and a release mechanism of the first element is effected via an interaction of a plurality of elements of the drive mechanism. For example, these elements spring elements, lever elements, and / or oil chambers, which are arranged in, before or after the Ansteuermechanismus be. In this case, at least one movement of an element of the drive mechanism is controlled via a pressure pulse. An oil chamber disposed in, before or after the drive mechanism causes a redirection of a pressure pulse to an element. An oil chamber may also have a retarding effect. The size of an oil chamber is one to ten cubic millimeters in one embodiment, ten to fifty cubic millimeters in another embodiment, and fifty to one hundred cubic millimeters in another embodiment. The spring elements in one embodiment have a spring stiffness of one Newton per centimeter to ten Newton per centimeter, in another embodiment a spring stiffness of ten Newton per centimeter to fifty Newton per centimeter, in one embodiment a spring stiffness of fifty Newton per centimeter to one hundred Newton per cent Centimeters and in another embodiment a spring stiffness of one hundred Newton per centimeter to five hundred Newton per centimeter on.

For example, the spring elements can be stretched over movable elements, for example lifting elements. The lever elements in one embodiment have a size of one to five millimeters, in another embodiment, a size of five to ten millimeters and in another embodiment, a size of ten to twenty millimeters. The lever elements have in one embodiment a transmission lever of one to five, in another embodiment, a transmission lever of five to ten and in another embodiment, a transmission lever ten to one hundred. In the springs, a mechanical energy can be stored, which at a later date, preferably a few power strokes of the reciprocating engine after tensioning the spring, can be dispensed again.

Preferably, a flywheel, which is driven by the oscillating movement of the connecting rod or the piston, within the Ansteuermechanismus application. Via a flywheel mass construction in conjunction with spring or holding elements, which are controlled depending on the relative position of the connecting rod to the piston pin, a storage of mechanical energy is enabled within the Ansteuermechanismus which causes, for example, a reinforcing mechanism within the Ansteuermechanismus. The amplification mechanism is controllable via a pressure pulse or is controlled over a certain predefined time sequence of pressure pulses. On the storage of mechanical energy within the drive mechanism, it is also preferable to use generators and electric motors.

The drive mechanism preferably has a single oil supply. This oil supply connects the drive mechanism to the pressure pulse generator. In contrast to a hydraulic actuation mechanism having two separate oil feeders for toggling, the feature of using only a single oil pipe is advantageous in that it greatly facilitates the construction of the oil supply to the drive mechanism.

In a further embodiment, a control mechanism upstream of the chamber is present, which is connected via a plurality of oil lines to the drive mechanism. In a development, a plurality of interconnected, the Ansteuermechanismus upstream chambers are provided. In this case, between an upstream chamber and the pressure pulse generator there exists at least a portion connecting the chamber to the pressure pulse generator via only a single oil conduit, i. H. the chamber has only a single oil supply. This oil supply is necessary for a hydraulic connection between the chamber and the pressure pulse generator.

An upstream chamber is preferably also arranged on the connecting rod or piston. An upstream chamber has, according to one embodiment, no component or section in common with the crankshaft. The oil supply of an upstream chamber is connected via an oil line to the crankshaft. A chamber upstream of the drive mechanism preferably delays the actuation of the drive mechanism via the pressure pulse generator.

In a further embodiment, a delay mechanism for delaying the switching of the adjusting mechanism is provided in a chamber upstream of the drive mechanism. The retarding mechanism includes, for example, a spring and / or a valve. It is constructed via a valve and a spring in an upstream chamber within an oil volume, a pressure which controls the drive mechanism from a preferably adjustable pressure level. The switching is delayed until the adjustable pressure level within the chamber is reached. The spring is designed to store mechanical energy. There is provided a transmission of the mechanical energy of a pressure pulse on the spring. In addition, for example, a pressure pulse controlled trigger mechanism for releasing the mechanical energy of the spring is provided.

The drive mechanism is controlled according to the above embodiment via the released mechanical energy of the spring. The released mechanical energy of the spring is higher according to an embodiment, preferably three to ten times higher than the mechanical energy of a pressure pulse. As a result, the necessary power of the pressure pulse generator for switching the compression ratio can be reduced. Charging the spring with mechanical energy causes a delay with a delay time. The delay time is given by the duration from the first sent pressure pulse to the triggering of the spring. In a further embodiment, a delay mechanism can also be arranged within the drive mechanism. In a further embodiment, a downstream delay mechanism is arranged on the drive mechanism.

The drive mechanism has at least one movable element. At least one movable element takes at least two different relative to the connecting rod or piston Positions, wherein to a first position, a first compression ratio of the reciprocating engine and a second position, a second compression ratio is assigned. The position of the movable element affects the flow of oil in the drive mechanism, which is triggered by a pressure pulse. The flow of the oil in the drive mechanism causes a pressure distribution in the drive mechanism. Depending on the position of the movable element causes a pressure pulse, a first pressure distribution of the oil in the drive mechanism corresponding to the first position of the element or a second pressure distribution of the oil corresponding to the second position of the element. The flow and the pressure distribution of the oil in the drive mechanism are preferably influenced by additional mechanical elements such as springs, balls or lever mechanisms. Similarly, multiple movable elements may affect the flow in the drive mechanism as well as the pressure distribution. If there are several movable elements in the drive mechanism, preferably the movement of one element influences the movement of another. Above all, a triggering of a chain reaction of movements, which are triggered by a pressure pulse, is possible with several moving elements.

Preferably, an influencing of the pressure distribution of the oil is provided by a geometrically variable oil space in the drive mechanism. It is provided depending on the position of the walls of the oil space certain inflow of oil in the oil chamber. Preferably, the geometric position of the volume is coupled to the position of a movable element.

For example, an alternating pressure distribution of the oil is provided by means of an alternating position of the movable element or a changing position of the walls of the oil space. A switching back and forth of the movable element is controlled in this way, for example, via a plurality of successive, the drive mechanism reaching rectified pressure pulses.

In one embodiment, a first displacement of the movable member in a direction from a first position to a second position is controlled by a single pressure pulse. In particular, during the first adjustment before the controlling pressure pulse, the element can assume a rest position between the first and the second position as well as the first position. Furthermore, the element can assume a rest position between the first and the second position and the second position, in particular during the first adjustment after the controlling pressure pulse.

Upon reaching the second position, a second displacement of the movable member in a direction from the second position toward the first position is controlled by a single pressure pulse. The element can occupy a rest position between the second and the first position and the second position, in particular during the second adjustment before the controlling pressure pulse. Furthermore, the element can assume a position between the second and the first position and the first position, in particular during the second adjustment after the controlling pressure pulse. A direction reversal of the pressure pulse-controlled movement of the movable element is effected by reaching the movable element of the first and the second position.

In another embodiment, switching of the movable member from a first to a second position is controlled by a single pressure pulse and subsequent switching of the same movable member from the second to the first position by a subsequent single pressure pulse.

In a further development, switching of a movable element from a first to a second position is controlled by a plurality of pressure pulses and subsequent switching of the same movable element from the second to the first position by a plurality of pressure pulses.

The number of necessary pressure pulses for switching a movable element is the switching pressure pulse number. In the following (Section 1), it is assumed that the drive mechanism does not cause switching of the adjustment mechanism of the VCR system even at a pressure pulse However, for example, in an upstream delay chamber, a certain level of pressure could first be built up by a plurality of successive pressure pulses which would not be reached by a single pressure pulse Could this be useful for FEV in one application? End of the question) (Start Section 1: for another at five to ten, for another at fifty to one hundred and for another at five hundred to one thousand.

The switching pressure pulse number is, for example, the design and number of delay elements, such as oil chambers or spring and lever elements, which are in, before, or after Driving mechanism are arranged determined. End Section 1) In another embodiment, the reciprocating engine is designed such that the pressure pulse generator of the reciprocating engine has a stepped piston and the stepped piston is hydraulically connected to an engine oil pump of the reciprocating engine. The stepped piston is designed with different sized piston diameters and thus represents a pressure booster. It is a the stepped piston before or downstream compensating element, preferably a pressure regulator, a pressure relief valve or a compensating volume provided. The compensation element is provided to compensate for the pressure fluctuations, which results from the operating pressure level of the engine oil pump, for example at different speeds. Such a pressure regulator comprises at least one pressure relief valve and an oil removal line preferably leading to the oil reservoir. Furthermore, the pressure regulator preferably also includes a pressure sensor and a control unit connected thereto, which regulates the pressure between the pressure pulse generator and the control mechanism via valves connected thereto.

In a further embodiment, the stepped piston is designed in several stages. The individual stages of the stepped piston can be switched independently of each other. By selecting a number of the switched stages, pressure pulses with different amounts can be generated. About the different strong pressure pulses of the pressure pulse generator, a variable control of the drive mechanism is provided with rectified, optionally different strong pressure pulses. This is particularly advantageous in connection with the use of valves in the control mechanism, which switch through from a defined pressure. With such valves and a multi-stage stepped piston, for example, an adjusting device for setting optionally a plurality of different compression ratios can be variably controlled. Adjustment of a selected compression ratio is controlled by a magnitude of the pressure pulse reaching the drive mechanism. Preferably, the strength of the pressure pulse generated by the pressure pulse generator is directly dependent on the number of switched stages of the stepped piston. The more stages of the stepped piston are switched, the higher the intensity of the pressure pulse. The difference of the value of the pressure generated by the pressure pulse generator at the time of adjusting the compression ratio from the value of the pressure generated at an output of the engine oil pump in the engine operation at the time of adjusting the compression ratio is the pressure pulse difference.

In one embodiment, the pressure pulse difference, which is generated by the stepped piston in the operation of the first stage, a value of three to four bar.

In this embodiment, the pressure pulse difference, which is generated by the stepped piston in the operation of the second stage, a value of four to eight bar.

In a further embodiment, the pressure pulse difference, which is generated by the stepped piston in the operation of the first stage, a value of four to eight bar. In this embodiment, the pressure pulse difference, which is generated by the stepped piston in the operation of the second stage, a value of eight to twenty bar on.

In a preferred embodiment, the reciprocating engine on four different compression ratios. The fourth compression ratio is higher than the third, the third higher than the second and the second higher than the first.

In a preferred embodiment, the generation of a pressure pulse by the stepped piston in the operation of the first stage and a reciprocation of an element of the drive mechanism, the reciprocating controlled from the first to the second compression ratio or from the third to the fourth compression ratio , In this embodiment, by generating a pressure pulse by the stepped piston in the second stage operation and by switching an element of the driving mechanism back and forth, the reciprocating is controlled from the first to the third compression ratio or from the second to the fourth compression ratio.

In one embodiment, the pressure pulse generator is designed as a pneumatic-hydraulic unit, which has an air compressor, a compressed air tank and an oil storage cylinder with an air chamber, wherein the oil storage cylinder is preferably designed as a pressure booster with different sized piston diameters. Preferably, the ratio of the piston diameter of the pressure booster is in a range of two to four, in another embodiment in a range of four to ten. With a pressure pulse generator with a pneumatic-hydraulic unit, for example, a pressure build-up in the oil storage cylinder can be built up to a value of four bar within 0.5 seconds and faster. In this case, a pressure pulse generator with a pneumatic-hydraulic unit allow a pressure build-up in the oil storage cylinder for driving the drive mechanism with a pressure pulse faster than a pressure pulse generator, which no having pneumatic-hydraulic unit for pressure build-up.

According to one embodiment, a constant pressure is maintained in the compressed air tank via the air compressor, which is required for the activation of the control mechanism during the entire operation of the reciprocating piston engine. If the drive mechanism is to be activated, an electrically operated 3/2-way valve preferably switches the air pressure of the compressed air reservoir to the air chamber of the oil storage cylinder. In an advantageous embodiment, the pressure in the air chamber is amplified by piston diameter of different size of the oil storage cylinder, d. H. the piston diameter of the air chamber of the oil storage cylinder is preferably larger than the piston diameter of the oil chamber of the oil storage cylinder. Due to this pressure increase, the air compressor can be dimensioned lower, for example. In an advantageous embodiment, the electrical 3/2-way valve switches the air pressure of the compressed air tank to the air chamber for approximately 0.5 seconds. Preferably, the Ansteuermechanismus triggers during this period and the approximately double volume of oil flows through the main bearings of the crankshaft. The oil amount for switching from a first compression ratio to a second is preferably 350-400 ml for a four-cylinder in-cylinder engine. After the switching of the driving mechanism, the 3/2-way valve disconnects the air tank to the air chamber of the oil storage cylinder and opens the connection of Air chamber to the environment. As a result, the oil storage cylinder can be filled with oil again. Preferably, a return spring accelerates a piston of the oil storage cylinder, so that in the oil storage cylinder, a negative pressure is built up and the oil storage cylinder is refilled. Refilling the oil storage cylinder with oil takes about one second. During the filling process, the oil pump of the reciprocating engine controls the increased Ölbedart.

In a preferred embodiment, the air compressor is not operated during the entire operation of the reciprocating engine. Instead, the air compressor is operated in response to a probability of changing a compression ratio. It can be calculated, for example, via a control unit, the probability of changing a compression ratio. This takes place, for example, via an evaluation of a measurement of current data of the reciprocating piston engine and via an evaluation of data stored in a memory about a driving behavior of a driver. If the probability calculated in this way is higher than a comparison value dependent on a selected operating strategy of the reciprocating piston engine, the power of the air compressor can be increased so that the pressure in the compressed air reservoir increases. If the required pressure in the compressed air tank is reached and a switching of the compression ratio is desired according to the measured current data of the reciprocating engine, the electrical 3/2-way valve can be operated so that the connection of the compressed air tank is made to the air chamber of the oil storage cylinder and switching the Compression ratio is done.

According to a further embodiment of the invention, the air compressor is driven by an electric motor, a belt and / or wheel drive of the reciprocating engine. Between the external drive of the air compressor, d. H. an electric motor, a belt and / or Rädertrieb, and the drive shaft of the air compressor is preferably interposed a clutch which is controlled by a control device and via a control signal causes a non-slip connection between the external drive of the air compressor and the drive shaft of the air compressor. In another embodiment, a centrifugal-controlled transmission between the belt drive for driving the air compressor and the drive shaft of the air compressor is provided.

Another embodiment provides an air compressor connected to an air brake system. The pressure built up within the air brake system, for example, represents a first compression stage. The air compressor itself represents a second compression stage. This, for example, the performance of the pressure pulse generator is increased or it can be used a smaller compressed air tank. According to one embodiment, the air compressor sucks the compressed air of the compressed air brake system and compresses this air to a higher pressure level than that of the compressed air brake system.

According to a further embodiment, the compressed air brake system comprises a vacuum system. In this case, the negative pressure generated by this system via a vacuum reservoir and a piston integrated therein, which applies a force to a piston of the oil storage cylinder or a piston within the compressed air tank, bring a supporting force in the system of the pressure pulse generator.

In a further embodiment, the air compressor of the pressure pulse generator is omitted in the event that the compressor of the compressed air brake system supplies a sufficiently high operating pressure for the pressure pulse generator. The air compressor may also be omitted if the compressor of an air suspension provides a sufficiently high operating pressure for the pressure pulse generator. For the last three mentioned embodiments, a control of the connection between the air brake system and the pressure pulse generator by means of an electrically actuated valve is provided.

A further embodiment provides that the oil storage cylinder has a rolling diaphragm for sealing the air chamber from an oil chamber of the oil storage cylinder. The rolling membrane is preferably designed as a hat or roll-fold membrane. By way of example, an internal lubrication within the rolling diaphragm is realized via a mixing composition of the rolling diaphragm adapted to the maximum operating pressure of the pressure pulse generator. Furthermore, an insert reinforcement of metal or plastic is preferably provided for the rolling diaphragm.

According to a further embodiment of the invention, a filling valve is provided in a line from an engine oil pump to the pressure pulse generator for filling the oil storage cylinder.

The filling valve for filling the oil storage cylinder can be actuated for example via a control device a few seconds after the triggering of the drive mechanism. But it is also a purely mechanical control for refilling the oil storage cylinder possible. For example, the filling valve is designed as a check valve in the oil line from the pressure pulse generator to the engine oil pump and blocks the flow direction from the pressure pulse generator to the engine oil pump, d. H. if there is a higher pressure in the oil storage cylinder than in the oil-connecting line between the engine oil pump and the oil storage cylinder. If a lower pressure prevails in the oil storage cylinder after the activation of the drive mechanism than in the oil-connecting line between the engine oil pump and the oil storage cylinder, because the oil storage cylinder is pushed back via a return spring, opens the check valve, so that the oil storage cylinder is filled with oil again.

According to a further embodiment, the reciprocating engine is designed such that a drive mechanism of a single connecting rod or piston of the reciprocating engine is hydraulically connected via at least one valve and an oil connection to the pressure pulse generator. A drive mechanism of a single connecting rod of the reciprocating engine is hydraulically controlled via a single valve.

A separate actuation of a control mechanism of a single connecting rod or piston by means of a pressure pulse is made possible via a separate control of a single connecting rod with a valve associated with the connecting rod. Through the separate operation of the drive mechanism, a separate control of the compression ratio of a single cylinder is realized. An adjustment of a compression ratio of the reciprocating engine via the adjustment of the compression ratios of the individual cylinders. In one embodiment, all cylinders are set to a nearly similar compression ratio during operation of the reciprocating engine. In a further embodiment, the compression ratios of the individual cylinders are set differently. The respective compression ratios of the individual cylinders can be adjusted by actuating the valve assigned to the connecting rod or piston of a cylinder.

In a preferred embodiment, an adjustment of the compression ratios of all cylinders is provided for adjusting the compression ratio of the reciprocating engine. For adjusting the compression ratio of the reciprocating engine, the drive mechanism of each cylinder is controlled by means of a pressure pulse.

In another embodiment, for the adjustment of the compression ratio of the reciprocating engine a sepatates adjustment, d. H. an adjustment of the compression ratio of a single cylinder or two or three cylinders provided. The separate adjustment allows operation of the reciprocating engine with different compression ratios of the individual cylinders. Furthermore, the separate adjustment after a faulty switching of a single driving mechanism of a cylinder enables a corrective driving of the malfunctioning driving mechanism of the cylinder. In this case, for example, a singular switching of a pressure pulse by a single valve which controls the passage of the pressure pulse to the faulty drive mechanism of the cylinder may be provided. Further, in a corrective driving of a malfunctioning driving mechanism of a cylinder may be provided locking of the valves, which are arranged between the pressure pulse generator and the non-malfunctioning cylinders. It is possible to subsequently change the compression ratio of the malfunctioning cylinder.

Advantageously, when filled, the oil storage cylinder stores an amount of oil that is greater than the amount needed to drive the drive mechanism of each cylinder of the reciprocating engine. For example, there is provided a corrective re-driving of a drive mechanism of a failed cylinder without refilling the oil storage cylinder. In a further embodiment, however, a storable in the oil storage cylinder amount of oil is provided, which allows the compression ratios of all cylinders of the Reciprocating reciprocating machine at least once. This may be useful, above all, in the case of very short-term acceleration processes of a motor vehicle, in which the compression ratio is switched back and forth within a few seconds and the short time interval does not allow a renewed refilling of the oil storage cylinder.

According to a wide embodiment, it is provided that each connecting rod of the reciprocating engine is hydraulically controllable via a respective individual oil storage cylinder. According to this embodiment, a faster driving of the individual cylinders is possible because the individual oil storage cylinders are made smaller than a single central oil storage cylinder with a larger oil storage volume and a concomitant greater inertia of the stored oil as well as the larger piston of the central oil storage cylinder.

According to a further embodiment, the individual oil storage cylinders are each connected via a compressed air line via an electrically operable valve with the compressed air tank. A valve in an oil line between the oil storage cylinder and the drive mechanism can then be omitted, for example.

According to a further embodiment, the individual oil storage cylinders are connected via a common compressed air line via an electrically actuated valve with the compressed air tank. A valve between the oil storage cylinder and the oil line via the crankshaft to the drive mechanism is then required, if the drive mechanism of each individual cylinder is to be controlled separately.

• a) Erzeugen eines Druckimpulses durch ein Druckimpulsgenerator, der hierfür Öl aus einem Ölreservoir nutzt,
• b) Weiterleitung des Druckimpulses vorzugsweise über eine Kurbelwelle der Hubkolbenmaschine zu einer Ölzufuhr des Ansteuermechanismus,
• c) Initialisierung einer Bewegung eines beweglichen Elementes des Ansteuermechanismus durch den Druckimpuls,
• d) Verändern des Verdichtungsverhältnisses der Hubkolbenmaschine durch die Bewegung oder eine veränderte Stellung des Elementes und Triebwerkskräfte der Hubkolbenmaschine.

According to a further aspect of the invention, which may also be followed independently of the above idea, a method for controlling a drive mechanism is proposed, which changes a compression ratio in a reciprocating piston engine with the following steps:

• a) generating a pressure pulse by a pressure pulse generator using oil from an oil reservoir for this purpose,
• b) forwarding the pressure pulse, preferably via a crankshaft of the reciprocating piston engine, to an oil supply of the activation mechanism,
• c) initialization of a movement of a movable element of the drive mechanism by the pressure pulse,
• d) changing the compression ratio of the reciprocating engine by the movement or a changed position of the element and engine forces of the reciprocating engine.

The steps are preferably carried out in succession, in particular directly one after the other, in the stated order. However, they can also be executed at least partially in a different order or simultaneously. In particular, the proposed method can also be performed together with a reciprocating piston proposed above. For example, one or more features of the reciprocating engine for the process can be used specifically as well as vice versa.

The method steps and / or methods described below can be carried out in a wide variety of different order and, above all, in combination with each of the other method steps or methods disclosed in this application. Preferably, in step a) of the method, the pressure pulse generator is supplied with an oil. This happens, for example, via a pump, which pumps the oil from an oil reservoir to the oil storage cylinder of the pressure pulse generator. The oil reservoir is for example either the oil pan of the lubricating oil supply system of the reciprocating engine itself or a separate oil tank. The pump may be the engine oil pump itself or a separate pump. Preferably, the oil is pumped from the oil pan of the lubricating oil supply system via the engine oil pump to the oil storage reservoir of the pressure pulse generator. An electrically operable valve arranged between the engine oil pump and the oil storage tank is controlled by a control unit so that the desired pressure is achieved in the oil storage tank. The pressure pulse is generated in the oil-filled oil storage cylinder via a piston surface, which is accelerated. The piston surface is preferably part of a stepped piston, which causes a pressure increase of an oil chamber of the oil storage cylinder relative to a pressure source external to the pressure source. The external pressure source is preferably the oil transported by the engine oil pump to the pressure pulse generator or another medium, ie a gas or a liquid which has an exergy. A further embodiment provides that the exergy of the medium is determined, for example, via a control unit. For example, a parameter characterizing the state of the medium, for example a temperature or a pressure, is determined via a sensor and transmitted to the control unit. In the control unit, the size is processed in a data processing step with comparison data, preferably compared. The comparison data can be stored in the control unit or be an input signal of the control unit. During the data processing step, the exergy of the medium and the maximum producible pressure pulse of the pressure pulse generator can be determined. It can be the exergy of the medium before or within the Oil storage cylinder can be determined. The control unit can control the acceleration of the piston surface as a function of the determined exergy of the medium before and / or within the oil storage cylinder. Preferably, the strength of the pressure pulse is controlled by the controller.

In a step b), for example, the pressure pulse generated in the pressure pulse generator can be conducted via an oil line and preferably a valve to the crankshaft of the reciprocating piston engine. The valve is designed as an electrically actuated valve or as a simple check valve. From there, the pressure pulse is further directed to an oil supply of the drive mechanism. In a step c), in one possible embodiment within the drive mechanism, the pressure pulse causes the movement of a movable element via an oil flow generated by the pressure pulse in a volume of the drive mechanism.

In a further step d), a movement of an accelerated element or a new position of the element achieved by a movement in a first embodiment triggers a mechanism directly via a mechanism. The mechanism can change the compression ratio of a cylinder via the engine power of the reciprocating engine.

In a second embodiment, movement of the element causes the formation of an oil flow which changes the pressure conditions within the drive mechanism and thus causes the movement of another element. The movement of such an accelerated element or a new position of this element achieved by the movement then triggers a mechanism via a mechanism, which changes the compression ratio of a cylinder via the engine forces of the reciprocating piston engine. In other embodiments, the interaction of a plurality of movable elements, such as springs, balls or lever elements, exploited with due to the movement of movable elements in different ways expressing oil flows to trigger a mechanism which the engine power of the reciprocating engine, the compression ratio of Cylinder changed.

• c.1) Verändern der Stellung des beweglichen Elementes des Ansteuermechanismus von einer ersten Stellung zu einer zweiten Stellung durch einen ersten Druckimpuls, sowie den zusätzlich nachfolgenden Schritten:
• e) Verändern der Stellung des beweglichen Elementes des Ansteuermechanismus von der zweiten Stellung unter Umkehrung des Stellweges bevorzugt zu der ersten Stellung über einen zweiten Druckimpuls,
• f) Änderung des Verdichtungsverhältnisses der Hubkolbenmaschine durch die veränderte Stellung des Elementes und die Triebwerkskräfte der Hubkolbenmaschine.

According to a development of the method, it is provided that the compression ratio is switched over the control mechanism only via a single oil supply with the following additional step in step c):

• c.1) changing the position of the movable element of the drive mechanism from a first position to a second position by a first pressure pulse, and the additional subsequent steps:
• e) changing the position of the movable element of the drive mechanism from the second position while reversing the travel preferably to the first position via a second pressure pulse,
• f) change of the compression ratio of the reciprocating engine by the changed position of the element and the engine power of the reciprocating engine.

According to one embodiment, it is provided that the pressure pulse for the activation of a single control mechanism in the connecting rod or piston for changing a compression ratio in a cylinder passes via an oil connection from one part of the crankshaft to another part of the crankshaft. The pressure pulse transporting oil occurs only at one point of the crankshaft. There is according to this embodiment in the crankshaft at least one oil-carrying portion, which must be passed by the oil flowing from the pressure pulse generator to the drive mechanism. Such a section is according to another embodiment in a connecting rod or in a piston of the reciprocating engine.

Achieved in a step c.1) or in a step e) a pressure pulse, the drive mechanism, an oil flow is formed, for example, in the drive mechanism, which changes the pressure on a surface of a movable element in the drive mechanism. In a first embodiment, an increase in pressure takes place on a surface of a movable element, which accelerates the element. In a second embodiment, a decrease in pressure takes place on a surface of a movable element which accelerates the element. In a further step f), the movement or the position occupied by the movement of the movable element triggers an adjustment of further elements in the drive mechanism or triggers a mechanism which changes the compression ratio in a cylinder via the engine forces of the reciprocating piston engine.

Preferably, a changed position of a first movable member is locked by means of a spring. In this case, the spring presses this first element on another second element, which has at least two mutually angled surfaces. The individual surfaces of this second element are preferably also rounded. In an advantageous embodiment, the first element has a surface which is partially complementary to the surface of the second element. Upon contact of the first element with the second element is formed by the contact of the mutually complementary surfaces of a lock, which inhibits the mobility of the first movable member or completely restricts. In a preferred embodiment, the second element is also movable. In a further embodiment, the second element is moved by the action of the pressure pulse reaching the drive mechanism. About the changed position of the locked movable member, the position or the geometry of the oil-absorbing volume of the drive mechanism is changed. The thus variable volume of the drive mechanism causes a pressure pulse reaching the drive mechanism or a plurality of pressure pulses successively reaching the drive mechanism to cause a change in oil flow in the drive mechanism relative to a pressure pulse previously reaching the drive mechanism. Thus, several different oil flows can be realized in the control mechanism via the emission of pressure pulses from the pressure pulse generator to the drive mechanism. These different oil flows cause different forces via different pressure distributions on movable and fixed elements of the drive mechanism. Preferably, the drive mechanism is configured such that a first oil flow causes a first movement of an element from a first position to a second position and a second oil flow causes a second movement of that element from the second position at least towards the first position. This assumes that the movable element is locked in a first position or in a second position or held by a pressure. The lock or the holder by the pressure dissolves, for example, as soon as a first or a second oil flow in the drive mechanism sets.

By means of the method described above, the emission of pressure pulses from the pressure pulse generator to the activation mechanism can cause the element to move back and forth. This reciprocal movement of an element triggers reciprocation of a mechanism mechanically connected to the drive mechanism, which changes the compression ratio in a cylinder over the engine forces of the reciprocating piston to one value to another.

• 0) Speicherung einer Ölmenge in dem Druckimpulsgenerator, welche bevorzugt zwei bis dreimal so groß ist wie die Ölmenge, welche für ein einfaches Umschalten aller Zylinder der Hubkolbenmaschine von einem ersten Verdichtungsverhältnis der Hubkolbenmaschine zu einem zweiten vom ersten verschiedenen Verdichtungsverhältnis der Hubkolbenmaschine benötigt wird, sowie den nachfolgenden Schritten nach dem Schritt d):
• g) Messung des Verdichtungsverhältnisses eines einzelnen Zylinders durch ein Steuergerät,
• h) Vergleich des gemessenen Verdichtungsverhältnisses in dem Zylinder gegenüber einem Sollverdichtungsverhältnis in diesem Zylinder,
• i) Wiederholung der Ansteuerung des Ansteuermechanismus zum Steuern des veränderbaren Verdichtungsverhältnisses in diesem Zylinder, falls die Abweichung des gemessenen Verdichtungsverhältnisses gegenüber dem Sollverdichtungsverhältnis außerhalb eines vordefinierten Toleranzbereiches liegt.

In another aspect, a method is proposed in which a drive mechanism of a single cylinder of a reciprocating engine is controlled independently of the drive mechanisms of the other cylinders of the reciprocating engine with the following additional step before step a):

• 0) storage of an amount of oil in the pressure pulse generator, which is preferably two to three times as large as the amount of oil which is required for a simple switching all cylinders of the reciprocating engine from a first compression ratio of the reciprocating engine to a second different from the first compression ratio of the reciprocating engine, and the subsequent steps after step d):
• g) measurement of the compression ratio of a single cylinder by a control unit,
• h) comparison of the measured compression ratio in the cylinder against a target compression ratio in this cylinder,
• i) Repetition of the control of the drive mechanism for controlling the variable compression ratio in this cylinder, if the deviation of the measured compression ratio from the target compression ratio is outside a predefined tolerance range.

The method steps described below can be carried out in addition to substituting the previously described steps.

In one step, a compression ratio of a single cylinder is determined by the control unit, preferably via a sensor connected to the control unit. In another correction step, the drive of the drive mechanism for controlling a variable compression ratio in this cylinder may be repeated. The correction step is performed if the deviation of the measured compression ratio from the target compression ratio is outside a predefined tolerance range.

According to this method, adjusting a compression ratio of a single cylinder via the separate driving of a single driving mechanism is realized independently of the driving mechanisms of the remaining cylinders within the reciprocating engine. Each individual control mechanism of a cylinder is assigned a single valve. Such a valve can be controlled via a control unit. Furthermore, stored in the pressure pulse generator is a storage oil amount which is two to three times as large as the amount of oil required for easy switching of all cylinders of the reciprocating engine from a first compression ratio of the reciprocating engine to a second different from the first compression ratio of the reciprocating engine. By storing a storage oil quantity in the oil storage cylinder, it is possible to control the activation mechanisms of the cylinders several times in succession without the oil storage cylinder having to be refilled. Thus, also a quick correction of the compression ratio in a cylinder is possible.

If a compression ratio, which deviates from a desired compression ratio by a value stored in a control unit, is measured in a cylinder, the activation mechanism in this cylinder is actuated via at least one pressure pulse by switching the valve through. The measured compression ratio deviating from the desired value is thereby corrected. The compression ratio of each individual cylinder is measured, for example, by means of measured thermodynamic variables, preferably in each outlet channel of each cylinder or also inside the cylinder. For example, a lambda value, a concentration of a gas in the exhaust gas or an in-cylinder pressure are measured for each cylinder. Subsequently, the respective measured values of the individual cylinders are compared with each other. The measured lambda values of the lambda probes of the individual cylinders are preferably compared. The comparison of the measured values, preferably the lambda values, and / or a further evaluation of the measured values, preferably the lambda values, with the aid of stored engine data assigns individual compression ratios to the individual cylinders.

In a further embodiment, a rapid switching back and forth of the compression ratio of all cylinders is possible, provided that the filled oil storage cylinder can store the required amount of oil. This quick toggling of all cylinders is especially desired for a low-speed ride on the highway followed by an overtaking operation with a strong acceleration and then quiet driving with low acceleration.

According to a further idea, a method is provided with which a thermodynamic variable, preferably an air quantity ratio, is measured in an exhaust system, preferably in an outlet channel of a cylinder. Depending on the measured value of the thermodynamic variable of a comparison value, the height and duration of the pressure pulse, which is generated by the pressure pulse generator, changed.

This method is useful in the application of the drive mechanism when the drive mechanism is mounted on the connecting rod or piston. Depending on the length of the oil connections in and before the reciprocating engine, different pressure losses of the pressure pulse result. By varying the height or the length of the pressure pulses generated by the pressure pulse generator, such a pressure loss can be compensated. The amount of the pressure pulse, which reaches the drive mechanism, can be approximately the same, for example, by means of this method, even with different design of the reciprocating engine, d. H. For example, differ by only about 0.5 bar depending on the design of the reciprocating engine. Furthermore, this method allows during normal operation of the reciprocating engine to adapt to the temperature and the viscosity of the oil, with which the drive mechanism is controlled. An adaptation to the occurring in the course of use of the reciprocating engine lowering the spring stiffness of the spring is possible with this method.

Another embodiment of the method provides for attaching small masses to the movable element. In this way, a design of the drive mechanism in the installed state take place.

According to a further embodiment of the method, it is provided that the pressure pulses are generated in a pneumatic-hydraulic manner in the pressure pulse generator. In this case, an oil storage cylinder with an oil chamber and a mechanically connected air chamber is provided. The oil pressure in the oil chamber is realized by an acceleration and thereby triggered movement of a piston, which is in direct communication with the oil chamber. The acceleration of the piston via a piston rod which connects the piston of the oil storage cylinder with a piston of a sealed from the oil storage cylinder by a rolling diaphragm air chamber. The piston of the air chamber is accelerated by a pressure increase in the air chamber. The pressure rise in the air chamber via the switching on of an air pressure, which prevails in a connected to the air chamber compressed air tank. The air pressure in the air pressure vessel is generated by a compressor, which is connected via a wheel or belt drive with the reciprocating engine or driven by an electric motor.

Further advantageous embodiments and developments will become apparent from the following figures. The following figures show an embodiment of a drive mechanism and several embodiments of a pressure pulse generator and an oil supply system of a drive mechanism. However, the details and features of the individual figures are not limited to this particular figure. Rather, one or more features may be linked to new features with one or more features from different figures as well as features resulting from the above description. In particular, the following statements do not serve as limitations of the respective scope, but explain individual features and their possible interaction with each other.

Show it:

1 an embodiment of an adjusting device for changing the compression ratio with a correspondingly shaped connecting rod,

2 a cross-sectional view of the connecting rod 1 along the section line II-II,

3 a sectional view of the connecting rod of 1 along section line III-III with an illustrative view of damping volumes,

4 a cross section of a drive mechanism, wherein the left half of a cross section of a drive mechanism in a first position and the right half shows a cross section of a drive mechanism in a second position,

5 1 is an exemplary schematic circuit diagram for a portion of an oil supply system of a drive mechanism from a pressure pulse generator to a connecting rod journal of a crankshaft;

6 3 is an exemplary schematic circuit diagram for a portion of an oil supply system of a drive mechanism from a pressure pulse generator to a connecting rod journal of a crankshaft with a check valve between the oil storage cylinder and the engine oil pump;

7 an exemplary schematic circuit diagram for a portion of an oil supply system of a drive mechanism from a pressure pulse generator to a connecting rod journal of a crankshaft with a check valve between the oil storage cylinder and the engine oil pump and a spring in the oil storage cylinder,

8th 1 is an exemplary schematic circuit diagram for a portion of an oil supply system of a drive mechanism from a pressure pulse generator to a connecting rod journal of a crankshaft with a check valve between the pressure pulse generator and the individual main bearings of the crankshaft;

9 1 is an exemplary schematic circuit diagram for a portion of an oil supply system of a drive mechanism from a pressure pulse generator to a connecting rod journal of a crankshaft, each with a check valve between the pressure pulse generator and the individual main bearings of the crankshaft;

10 1 is an exemplary schematic circuit diagram for a portion of an oil supply system of a drive mechanism from a pressure pulse generator to a connecting rod journal of a crankshaft without a valve between the pressure pulse generator and the individual main bearings of the crankshaft;

11 1 is an exemplary schematic circuit diagram for a portion of an oil supply system of a drive mechanism from a pressure pulse generator to a connecting rod journal of a crankshaft without a valve between the pressure pulse generator and the individual main bearings of the crankshaft and without an additional direct oil-carrying connection between the engine oil pump and the oil storage cylinder;

12 an exemplary schematic circuit diagram for an oil supply from a pressure pulse generator to a crankshaft with a stepped piston as a pressure pulse generator,

13 a connecting rod with a switching element arranged on the large connecting rod eye,

14 a hydraulic directional valve for the hydraulic control of a working space in a connecting rod,

15 Cam elements connected to a push rod,

16 an interaction of a switching element and a functional surface "return" and a functional surface "lead" in a side view,

17 an interaction of a servomotor and a cam member,

18 a cylinder crankcase with an oil pan top and an actuator unit,

19 cam plate elements connected to a connecting plate,

20 a top view of a cam unit with an oil pan shell,

21 a side view of an oil pan upper part with a servomotor and a connecting plate of a cam unit,

22 a servomotor with a Anlenkexzenter,

23 an interaction between a switching element and a functional surface,

24 a connection between a sump shell and a cam unit.

To carry out an adjustment of a compression ratio of a reciprocating engine is within the scope of this disclosure to the full content of DE 10 2005 055 199 A1 referred to the applicant. The following descriptions of the 1 to 3 contains contents of the prior art, which in the document DE 10 2005 055 199 A1 is disclosed.

1 shows an embodiment by means of which an adjustable change of a compression ratio is enabled in a reciprocating internal combustion engine. A connecting rod 17 has a large connecting rod eye 3 and a small connecting rod eye 2 on. In the small connecting rod eye 2 is again an eccentric 5 arranged, which is rotatably mounted. The eccentric 5 has a hole 18 for receiving a piston pin. On an outer surface facing the eccentric 5 a gearing 19 on. With this gearing 19 is the eccentric 5 with a lever system 20 connected, which acts as a support mechanism and preferably also as a backstop. The lever system 20 has a first lever 21 and a second lever 22 on. About the lever system 20 are the two levers 21 . 22 firmly coupled together. About the gearing 19 again, the levers 21 . 22 thus also rotatably with the eccentric 5 connected.

Out 1 is further evident that the lever system 20 is guided axially. Furthermore, the lever system 20 connecting joints 24 on. About the joints 24 are rods 25 hinged. In the connecting rod 17 in turn are support cylinder bores 26 arranged. In these are pistons 27 led at which the rods 25 are articulated. By this arrangement, a respective stroke of the two pistons is in direct relation to a twist angle of the eccentric 5 , The support cylinder bores 26 in the second connecting rod 27 are through check valves 28 to the large connecting rod eye 3 closed off, leaving a working space 29 is formed. The working space can thus serve as a damping volume as well as a support in the case of a backstop. In the big connecting rod eye 3 are connecting rod bearing shells 6 arranged. The connecting rod bearing shells 6 are with breakthroughs 7 Mistake. Because the cups 6 are provided with a circumferential groove, which is in connection with an oil supply through the crankshaft, is in the groove at any time to an oil pressure. This oil pressure is transmitted to the check valves at all times 28 , These open or are closed depending on the working space 29 present working pressure.

2 shows a longitudinal section through the connecting rod 17 along the section line II-II 1 , It is a first horizontal line of symmetry 9 a hole 10 shown for a piston pin. Furthermore, a second horizontal line of symmetry 11 a crankpin receiving space 12 shown. A shortest possible distance between the first line of symmetry 9 and the second line of symmetry 11 is the first effective length l _{eff1 of} the connecting rod 17 designated. Furthermore, a horizontal position line 13 the first line of symmetry 9 in 2 located. The first line of symmetry 9 is with the horizontal position line 13 congruent if the effective length of the connecting rod 17 l should be _eff2 . The first effective length l _{eff1 of} the connecting rod 17 is associated with a first compression ratio of a cylinder and / or the reciprocating engine. The second effective length l _{eff2 of} the connecting rod 17 is assigned a second compression ratio of a cylinder and / or the reciprocating engine. For adjusting the effective length of the connecting rod 17 has the connecting rod 17 several elements. In the upper area near the small connecting rod eye 2 has the connecting rod 17 a switching element 31 as a changeover valve and a drive mechanism 41 for driving the switching element 31 on. The switching element 31 is constructed as a 3/2-way valve. It's right across the connecting rod 17 slidably arranged. By means of a locking mechanism 32 can the switching element 31 be moved into a first detent position and a second detent position. In 2 is the switching element 31 shown in the first detent position. For this purpose, the switching element protrudes 31 at least on a surface of the second connecting rod 17 out. A snap in one of the two locking positions is in accordance with the locking mechanism shown here 32 via a spring-loaded ball 33 allows, in corresponding recesses of the switching element 31 intervenes. The switching element 31 is shown here in the form of a valve body. Preferably, such a recess is a circumferential groove in the switching element 31 , In the connecting rod 8th are different connection holes 34 arranged, which can have different functions. An activation or closing of these connection holes 34 takes place via switching of the switching element 31 , which with the connecting holes 34 is coupled. This way, when in the connecting rod 17 realized design via the 3/2-way valve allows the work spaces 29 each alternately, but not open at the same time. By inflow or outflow can thus be effected a damping. The connecting rod has an orifice plate in each case 34.1 in the connection holes 34 on, which results in a set resistance on the eccentric 5 acts.

3 shows a sectional view taken along the line through the section III-III in 1 shown connecting rod 17 , 3 shows next to a location of the workrooms 29 also the relative position of the connecting holes 34 , Between the connection holes 34 and the workspaces 29 are overpasses 35 arranged as cross connections.

The operation of the second connecting rod 17 for setting a different compression ratio is explained below using the example of a setting of a low compression ratio. If a low compression ratio is desired during engine operation, the 3/2-way valve will be in the in 2 shown position brought. In those engine phases where compressive forces on the connecting rod 17 loads, builds in the first workspace 29.1 a pressure on. A control edge 35 of the switching element 31 gives a drainage hole 36 free. This can be in the first workspace 29.1 be displaced oil. At the same time, fresh oil is added to the second working space 29.2 sucked. The eccentric 5 can thus move in the direction of the arrow 37 in 1 twist. An engine power reverses before the second piston 27.2 through a stopper 38 achieved formed mechanical stop, a dipping motion comes to a brief halt, until again a compressive force on the second connecting rod 17 overloaded. A twist of the eccentric 5 in the opposite direction is not possible because the first working space 29.1 is closed and the first piston 1.27 can not dive. Depending on the design of one or more hydraulic resistors and a size of the engine forces, therefore, a dipping process can extend over several working cycles. The hydraulic resistance is preferably formed by the connecting line or by a throttle located therein. An adjustment is preferably completed when the second piston 29.2 on the check valve 28 has arrived.

4 shows in the left half of the picture the right part of a drive mechanism 41 in 2 for triggering an adjusting device 40 , which changes the compression ratio in a cylinder via the engine forces of the reciprocating engine, wherein the Ansteuermechanis 41 via pressure pulses, which only a single oil supply 44 to the drive mechanism 41 arrive, is controlled.

The drive mechanism 41 includes a first movable element 43 , a second moving element 80 , a feather 81 a frame 82 , an oil supply 44 , an oil pipe 46 , a first variable volume 45 for filling and draining oil, an upper edge 84 , a lower edge 85 , a first recess 86 , a second recess 87 and a second variable volume 88 for filling and draining oil. The drive mechanism 41 is located with its frame 82 stationary on a connecting rod 42 the reciprocating engine. The first changeable volume 45 will be the first recess 86 enlarged when the first recess 86 is free. The second variable volume 88 becomes the second recess 87 enlarged when the second recess 87 is free.

The left half of 4 shows the first moving element 43 in the first position 58 , The first moving element 43 touches the switching element 31 which is in 2 is shown. The position of the switching element 31 in the left half of 4 corresponds to the illustrated first detent position of the switching element 31 in 2 ,

According to the description of 1 to 3 can by means of the locking mechanism 32 the switching element 31 be locked in a first and in a second detent position. The first detent position is according to the descriptions of 1 to 3 a first compression ratio and the second detent position associated with a second of the first different compression ratio of the reciprocating engine. About the coupling of the switching element 31 with the first moving element 43 of the drive mechanism 41 is the first position 58 of the first movable element 43 assigned a first compression ratio.

About the oil supply 44 a pressure pulse 54 in the oil line 46 , so on the second movable element 80 built up a pressure which the second element 80 to the right to the attachment point of the spring 81 emotional. This is the first element 43 no longer with respect to a movement in the direction of the upper edge 84 arrested and can be within the frame 82 to the upper edge 84 move. Because the first element 43 has an inertia, it is in the oscillating motion of the frame 82 , which is stationary relative to the connecting rod 42 or piston is, one to the frame 82 experience relative acceleration. The first element 43 consequently moves during a rotation of the crankshaft in the direction of the upper edge 84 of the frame 82 and hits the top edge 84 at. The first element 43 is with the switching element 31 the adjustment 40 connected. The upward movement of the element 43 towards the top edge 84 is with a movement of the switching element 31 coupled. Moves the first element 43 up to the stop on the upper edge 84 , so the switching element moves 31 in the direction of the arrow 91 , As soon as the first element 43 near the top edge 84 is the second element 80 from the spring 81 in the second recess 87 of the first element 43 pressed. This position is in the right half of 4 shown. The first element 43 is in this position by the spring 81 arrested, ie the first element 43 can not relative to the frame 82 be moved by the oscillating movement of the connecting rod or piston. This position corresponds to a second position 59 of the first movable element 43 , Is the first moving element 43 in the second position 59 so is the switching element 31 locked in the second detent position.

About the coupling of the switching element 31 with the first moving element 43 of the drive mechanism 41 is thus the second position 59 of the first movable element 43 associated with a second compression ratio.

Achieved a second pressure pulse 54 the in 4 shown part of the drive unit, so starting from the in the right half of the 4 shown second position 59 of the first movable element 43 this pressure pulse 54 through the second variable volume 88 for filling and draining oil to the second element 80 directed. This pressure pulse 54 causes a release of the locking of the second element 80 opposite the first element 43 ie the first element 43 can be within the frame 82 move. About the oscillating motion of the frame 82 the first element arrives 43 to the lower edge 85 and suggests there, see left half of the 4 , The downward movement of the first element 43 towards the lower edge 85 is with a movement of the switching element 31 coupled. The control edge 89 of the first element 43 , what a 2 is shown, in cooperation causes a downward movement of the first element 43 towards the lower edge 85 a sliding of the switching element 31 in the direction of the arrow 90 ,

As soon as the first element 43 near the bottom edge 85 is the second element 80 from the spring 81 in the second recess 87 of the first element 43 pressed. This is the first element 43 locked in this position, ie the first element 43 can not relative to the frame 82 be moved by the oscillating movement of the connecting rod or piston. This position corresponds to the first position 58 of the first movable element 43 ,

Is the first moving element? 43 in the first position 58 so is the switching element 31 locked in the first detent position. This first detent position of the switching element 31 is assigned a first compression ratio. About the coupling of the switching element 31 with the first moving element 43 of the drive mechanism 41 is thus the first position 58 of the first movable element 43 again assigned the first compression ratio.

5 shows an example of a schematic circuit diagram for a section of an oil supply system 47 a drive mechanism 41 from a pressure pulse generator 52 via an oil connection 51 to a connecting rod journal 104 a crankshaft 53 , The oil compound 51 includes a portion of an oil strand 57 between a crankshaft bearing 71 and an engine oil pump, a crankshaft bearing 71 and a hole 103 , The crankshaft 53 is in the crankshaft bearings 71 stored, from which oil over the holes 103 to the connecting rod journal 104 arrives. The driving mechanisms for varying the compression ratios in the individual cylinders are hydraulically with a connecting rod journal each 104 connected to a cylinder.

The pressure pulse generator 52 is over an oil connection 50 and an engine oil pump 72 with an oil reservoir 48 connected.

The engine oil pump 72 is preferably designed as a volume flow-controlled hydraulic pump, preferably a hydraulic pump with a fixed direction of rotation. A section of the oil connection 50 is through an oil distribution gallery 107 educated. From there, the oil flows in oil strands 57 to the crankshaft 53 and in an oil line 109 to the other consumers. The lubricating oil supply system 55 the reciprocating engine includes the oil reservoir 48 , the engine oil pump 72 , the oil distribution gallery 107 , the oil compound 50 and the oil strands 57 ,

The pressure pulse generator 52 includes a filling valve 69 , an air compressor 62 with an electric motor 66 , a compressed air tank 63 , an electrically operated valve 110 , an oil storage cylinder 64 , a manifold 114 and valves 115 , The air compressor 62 can be carried out in one or two stages and should deliver a pressure of about 10 bar.

Will now be a pressure pulse 116 for the drive mechanism 41 needed to adjust a compression ratio in a cylinder, switches an electrically operated valve 110 , preferably a 3/2-way valve, the pressure of the air pressure vessel 63 on the air chamber 65 of the oil storage cylinder 64 , The air chamber 65 is by means of the piston 111 from the oil chamber 112 , which is filled with engine oil and is under engine oil pressure prior to switching, disconnected. The piston 111 is located in the airside stop. A filling valve 69 in the pipe 113 is closed at the time of activation. The piston 111 pushes the oil into the manifold 114 and through the open valves 115 in the individual oil compounds 51 where the pressure in front of the crankshaft bearings 71 increases. A check valve 56 in the oil strand 57 prevents backflow into the oil connection 50 ,

The pressure pulse 116 takes about 0.5 seconds. This duration is to ensure that within this time an actuation of the control mechanisms 41 he follows. During this time, approximately twice the oil volume flow flows into a crankshaft bearing 71 a compared to the operation of the reciprocating engine when the valves 115 are not open and no pressure pulse 116 a drive mechanism 41 should reach. This twice as large oil flow comes preferably exclusively from the oil storage cylinder 64 , The amount of oil for one shift is approximately 350-400 ml for a four-cylinder in-line engine. After 0.5 seconds, the valves close 115 , The oil chamber 112 is then immediately refilled with oil by the filling valve 69 immediately opens. The valve 110 simultaneously empties the air chamber 65 , Refilling takes up to 1 second. During the filling process, the engine oil pump regulates 72 the increased oil demand.

6 shows an example of a schematic circuit diagram for a section of an oil supply system 247 a drive mechanism 41 from a pressure pulse generator 252 via an oil connection 251 to a connecting rod journal 204 a crankshaft 253 , This section of the oil supply system 247 has partly the same components as the oil supply system 47 which is in 5 is shown. By principle, the oil supply system works 247 analogous to the oil supply system 47 which is in 5 is shown. The reference numerals of the components associated with the in 5 correspond to components shown are compared to the reference numerals of in 5 pictured components by a value of 200 higher.

The end 5 resulting filling valve 69 of such oil supply system 47 is different in the 6 through a filling check valve 269 replaced. This embodiment allows a simpler construction of the oil supply of the pressure pulse generator 252 , Alternatively, the simple non-controlled check valve 269 be replaced by a controlled check valve.

7 shows an example of a schematic circuit diagram for a section of an oil supply system 347 a drive mechanism 41 from a pressure pulse generator 352 via an oil connection 351 to a connecting rod journal 304 a crankshaft 353 , This section of the oil supply system 347 has partly the same components as the oil supply system 247 which is in 6 is shown. By principle, the oil supply system works 347 analogous to the oil supply system 247 which is in 6 is shown. The reference numerals of the components associated with the in 6 correspond to components shown are compared to the reference numerals of in 6 depicted components by a value of 100 higher.

In contrast to that 6 resulting oil supply system 247 points the oil storage cylinder 364 according to 7 in addition a return spring 326 on. The return spring 326 can a faster and safer filling of the oil storage cylinder 364 after generating a pressure pulse 354 guarantee. The return spring 326 is preferably designed with a multi-stage spring stiffness to accelerate the piston 311 from the rest position for generating a pressure pulse 354 to facilitate.

8th shows an example of a schematic circuit diagram for a section of an oil supply system 447 a drive mechanism 41 from a pressure pulse generator 452 via an oil connection 451 to a connecting rod journal 404 a crankshaft 453 , This section of the oil supply system 447 has partly the same components as the oil supply system 47 which is in 5 is shown. By principle, the oil supply system works 447 analogous to the oil supply system 47 which is in 5 is shown. The reference numerals of the components associated with the in 5 correspond to components shown are compared to the reference numerals of in 5 pictured components by a value of 400 higher.

From 5 resulting valves 115 of such oil supply system 47 are different in the 8th by a pressure pulse check valve 415 replaced. This version is simpler than a four-valve version.

9 shows an example of a schematic circuit diagram for a section of an oil supply system 547 a drive mechanism 41 from a pressure pulse generator 552 via an oil connection 551 to a connecting rod journal 504 a crankshaft 553 , This section of the oil supply system 547 has partly the same components as the oil supply system 47 which is in 5 is shown. By principle, the oil supply system works 447 analogous to the oil supply system 47 which is in 5 is shown. The reference numerals of the components associated with the in 5 correspond to components shown are compared to the reference numerals of in 5 pictured components by a value of 500 higher.

From 5 resulting valves 115 of such oil supply system 47 are different in the 9 by a respective pressure pulse check valve 515 replaced. The pressure pulse check valves 515 may be in a noncontrolled or controlled manner. In the case of non-controlled execution, the independent drive is a single drive mechanism 41 a single cylinder is not possible. In the case that the pressure pulse check valves 515 in a controlled embodiment, it is possible a driving mechanism 41 a single cylinder to control separately, for example, a Misalignment of a cylinder when switching from one compression ratio to another to compensate. With the help of controlled pressure impulse check valves 515 where it is preferable to prevent the opening when driven, it is possible to switch from one compression ratio to another without driving the pressure pulse check valves 515 perform, which reduces the system inertia. Only if a malfunction of a cylinder is to be compensated when switching from one compression ratio to another, the valves are controlled, the cylinders are not malfunctioned. The remaining pressure pulse check valves 515 , which are not controlled, open and cause the associated cylinders to switch from one compression ratio to another, ie they compensate for the previous malfunction.

Misalignment is detected by indirectly determining the compression ratio of each individual cylinder and the compression ratio thus determined prior to generating a pressure pulse 516 versus the compression ratio after generating a pressure pulse 516 is compared. If the two compression ratios determined in this way are the same, there is a faulty circuit. The compression ratio can be determined as follows. Thermodynamic quantities are preferably measured in each outlet channel of each individual cylinder or also inside the cylinder. A lambda value, a concentration of a gas in the exhaust gas or an in-cylinder pressure is measured for each cylinder. Subsequently, the respective measured values of the individual cylinders are compared with each other. The measured lambda values of the lambda probes of the individual cylinders are preferably compared. The comparison of the measured values, preferably the lambda values, and / or a further evaluation of the measured values, preferably the lambda values, with the aid of stored engine data assigns individual compression ratios to the individual cylinders.

10 shows an example of a schematic circuit diagram for a section of an oil supply system 647 a drive mechanism 41 from a pressure pulse generator 652 via an oil connection 651 to a connecting rod journal 604 a crankshaft 653 , This section of the oil supply system 647 has partly the same components as the oil supply system 47 which is in 5 is shown. By principle, the oil supply system works 647 analogous to the oil supply system 47 which is in 5 is shown. The reference numerals of the components associated with the in 5 correspond to components shown are compared to the reference numerals of in 5 pictured components by a value of 600 higher.

From 5 resulting valves 115 of such oil supply system 47 are different in the one in the 10 shown oil supply system 647 not included. This version is simpler than a four-valve version 115 ,

11 shows an example of a schematic circuit diagram for a section of an oil supply system 747 a drive mechanism 41 from a pressure pulse generator 752 via an oil connection 751 to a connecting rod journal 704 a crankshaft 753 , This section of the oil supply system 747 has partly the same components as the oil supply system 647 which is in 10 is shown. By principle, the oil supply system works 747 analogous to the oil supply system 647 which is in 10 is shown. The reference numerals of the components associated with the in 10 correspond to components shown are compared to the reference numerals of in 10 depicted components by a value of 100 higher.

From 10 resulting oil line 613 and the filling valve 669 of such oil supply system 47 are different in the one in the 11 shown oil supply system 747 not included. The filling of the oil storage cylinder 764 after generating a pressure pulse 716 takes place via the oil strands 757 , the check valves 756 , the oil compound 751 and the manifold 714 ,

12 shows an example of a schematic circuit diagram for a section of an oil supply system 847 a drive mechanism 41 from a pressure pulse generator 852 via an oil connection 851 to a connecting rod journal 804 a crankshaft 853 , This section of the oil supply system 847 has partly the same components as the oil supply system 47 which is in 5 is shown. By principle, the oil supply system works 847 analogous to the oil supply system 47 which is in 5 is shown. The reference numerals of the components associated with the in 5 correspond to components shown are compared to the reference numerals of in 5 imaged components by a value of 800 higher.

From 5 resulting pneumatic generation of a pressure pulse 116 of such oil supply system 47 is different in the 12 by a hydraulic generation of the pressure pulse 816 with the help of a stepped piston 830 replaced. The pressure pulse generator 852 includes a valve 829 which is preferably electrical is operable, a stepped piston 830 , a manifold 814 and valves 815 ,

Will now be a pressure pulse 816 for the drive mechanism 841 needed to adjust a compression ratio in a cylinder, switches an electrically operated valve 829 the pressure of the engine oil pump 872 over the oil connection 850 on the stepped piston 830 , The stepped piston 830 has two pistons with different piston diameters, so that an amplification of the pressure, which of the engine oil pump 872 is generated.

The stepped piston 830 pushes the oil into the manifold 814 and through the open valves 815 in the individual oil compounds 851 where the pressure in front of the crankshaft bearings 871 increases. A check valve 856 in the oil strand 857 prevents a backflow into the oil distribution gallery 807 ,

The pressure pulse 816 takes about 0.5 seconds. This duration is to ensure that within this time an actuation of the control mechanisms 841 he follows. During this time, approximately twice the oil volume flow flows into a crankshaft bearing 871 a compared to the operation of the reciprocating engine when the valves 815 are not open and no pressure pulse 816 a drive mechanism 841 should reach. This twice as large oil flow is preferably exclusively from the stepped piston 830 , The amount of oil for one shift is approximately 350-400 ml for a four-cylinder in-line engine. After 0.5 seconds, the valves close 815 , The filling of the stepped piston 830 after generating a pressure pulse 816 takes place via the oil strand 857 , the check valves 856 , the oil compound 851 and the manifold 814 ,

13 shows a connecting rod 1000 in which a switching element 1001 at the big connecting rod eye 1002 is arranged. An adjusting device for adjusting an adjustable variable compression ratio is at the small connecting rod eye of the connecting rod 1000 arranged. This adjusting device is in 13 through a piston 1006 covered. In particular, the switching element 1001 in the connecting rod cap 1003 be integrated. Furthermore, a cam member 1004 for actuating the switching element 1001 be arranged below the crankshaft of the reciprocating engine. In particular, a cam disk element is provided for each connecting rod of a cylinder of the reciprocating piston engine. The individual cam elements of the respective cylinders are preferably a preassembled module 1005 summarized. This in 13 illustrated module 1005 is intended for a 6-cylinder in-line engine.

14 shows a hydraulic directional valve 1010 for the hydraulic control of a working space, as it is for example in 1 as a workspace 29.1 respectively. 29.2 is executed. In particular, there is the hydraulic directional control valve 1010 a respective assigned to a working space drainage hole free. Such a drainage hole is for example in 2 as a drainage hole 36 shown. The hydraulic directional valve 1010 has at least 2 switching positions. In a patent application of the applicant FEV GmbH of the same filing date 30.07.2012 entitled "Hydraulic freewheel for variable engine parts are different ways of interconnecting a hydraulic directional valve described. In this application, reference is made in terms of a possible embodiment of the hydraulic circuit in the connecting rod as well as the design of the circuit in the connecting rod in its entirety in the context of the disclosure of this present application. In a specific embodiment, the directional control valve 1010 over the switching element 1011 controlled. It can by a movement of the switching element 1011 the directional valve 1010 be transferred to a specific switch position. Both a monostable and a bistable configuration is possible.

Further shows 14 an embodiment of a hydraulic directional control valve as a 3/2-way valve with a switching element 1011 , which in particular in the connecting rod bearing cap 1003 can be integrated. The 3/2-way valve function is characterized by the interaction of a first 2/2-way valve 1012 and a second 2/2-way valve 1013 realized. The 2/2-way valves 1012 and 1013 can be designed as seat valves, for example by a ball check valve, which can be pressed on a plunger. A first pestle 1014 is the first 2/2-way valve 1012 assigned. Furthermore, a second pestle 1015 the second 2/2-way valve 1013 assigned. The two pestles 1014 and 1015 are through the switching element 1011 controllable. The switching element can by means of a locking device 1016 be held in a certain switching position. The locking device 1016 can via a resilient pressure piece 1017 and one on the switching element 1011 reconditioned catch contour 1018 will be realized. So that the plungers do not inadvertently open the 2/2-way valve valves under the influence of inertial forces, the plungers are against the switching element by springs 1011 pressed.

In a specific embodiment, the actuation of the hydraulic directional control valve 1010 mechanically executed. In a further embodiment, the actuation of the hydraulic directional control valve 1010 hydraulically using oil pressure variations. In a different embodiment, the actuation of the hydraulic directional control valve 1010 executed using an oil jet. In this case, in particular an exchange of pulses between the oil jet and the hydraulic way valve 1010 , In a further embodiment, the actuation of the hydraulic directional control valve 1010 about a variation of one near the hydraulic directional control valve 1010 executed magnetic field.

In an embodiment in which the actuation of the hydraulic directional control valve 1010 is executed hydraulically, is the hydraulic directional control valve 1010 preferably connected to a hydraulic cylinder. A stroke of the hydraulic cylinder preferably acts on the hydraulic directional control valve 1010 , This hydraulic cylinder is referred to below as a hydraulic switch, since this affects the switching position of the directional control valve. In the simplest case, this hydraulic switch consists of a piston which acts against a spring force. The one effective surface of this piston is connected to a pressure oil line, which in turn is connected to the engine lubrication system. By varying the oil pressure, the switch position can be influenced. When pressure increases, the spring is compressed and when pressure is released, the spring relaxes again. The switch has thereby a monostable mode of operation, analogous to a button. In order to be able to permanently hold a certain switch state, the oil pressure must therefore also be raised or lowered permanently, ie the oil pressure must be varied statically.

In a two-stage operation of a variable engine component, such as a variable length effective connecting rod, the switch may be configured as follows: In a first embodiment, a valve is pressurized to a low pressure. In this case, a freewheeling direction of the eccentric is effected in the direction of a low compression ratio. In a second embodiment, a freewheeling direction of the eccentric can be effected in the direction of a high compression ratio.

Assuming that the pressure oil line is connected to the connecting rod bearing, the supply oil pressure at the main bearing and thus the pressure at the outlet of the oil pump must be varied to operate. The engine should usually be operated only in high load, low compression modes. The second variant has the advantage that the engine must be operated at high load with raised oil pressure. The associated higher oil pump drive power only leads to a slight increase in the total engine friction at high load and is to be preferred for efficiency considerations.

Another embodiment has a hydraulically dynamic switch. The dynamic hydraulic switch is designed to allow a bistable mode of operation. To change a switch position, the oil pressure needs to be raised or lowered only in time. Preferably, the switch responds to short-term pressure increases. One possible embodiment of a hydraulically dynamic switch is in 4 shown. In the event of a fault, however, it can happen that a switch does not switch. So not all cylinders of a motor have the same switch position. This problem can be solved by extending the described switch by a "reset function". This function provides that the switch automatically falls below an oil pressure threshold assumes a preset switching position regardless of the previously adopted switching position. This shift position deviations can be easily remedied due to faulty switching by the engine is switched off for a short time.

In the following an embodiment will be described, in which the operation of the Schaltelmentes 1011 is mechanically executed. In particular, the mechanical actuation takes place by means of cam elements as they are in 13 are shown.

15 shows a first cam member 1021 and a second cam member 1022 , which with a push rod 1020 are connected. The cam elements 1021 and 1022 are in particular using two guide rods 1023 guided. Each cam element preferably has two functional surfaces "leading" 1025 and two functional areas "return" 1026 on. The frontal tip of the switching element 1024 can in particular by the functional area "lead" 1025 be moved axially. An exemplary axial displacement of the switching element 1024 is with the arrow 1027 shown. With an axial displacement 1027 of the switching element 1024 has the switching element 1024 in relation to the cam member 1021 preferably at least one longitudinal displacement 1028 on. To shearing the Schaltementes 1024 to prevent a reverse rotation of the crankshaft, has the cam member 1021 the functional area "return" 1026 on. This area can be made steeper, since only low web speeds are to be expected.

In 16 is the interaction of a switching element 1030 and a functional area "return" 1031 and a function area "forerun" 1032 shown in the side view. The central axis of the switching element 1030 describes a trajectory 1033 whose shape depends on the position of the switching element on a connecting rod 1034 and the engine geometry is dependent. A cam element 1035 is opposite the bedplate 1036 axially by a certain amount procedure to take up the respective positions. The travel is for example about 4 mm. During the process of the cam member 1035 this is using the guide rods 1038 guided. With a push rod 1037 a rack is firmly connected.

17 shows an interaction of a servomotor 1040 and a cam member 1041 , The cam element 1041 is done by means of a pinion 1042 over a rack 1043 through the servomotor 1040 driven. The servomotor 1040 For example, it can be a 12V electric motor with a reduction gearbox. A preassembled operating unit 1044 , which at least the cam member 1041 , the pinion 1042 and the rack 1043 can be screwed from below against a bedplate of the reciprocating engine. 17 also shows guide rods 1045 for guiding the cam members during a displacement of the cam members.

18 shows a cylinder crankcase 1050 with an oil pan shell 1051 and an operating unit 1052 , The operating unit 1052 has at least one cam member 1053 on. In this embodiment, the mechanical actuator is 1052 in the oil pan shell 1051 integrated. The cylinder crankcase 1050 is preferably designed in the "short skirt" construction with Einzellagerkappen. To stiffen the entire structure is preferably a suitably rigid oil pan shell 1051 from below against the cylinder crankcase 1050 screwed. For a complete rotation of a crankshaft 1054 results for the central axis of a switching element 1055 a trajectory 1056 ,

19 shows with a connection plate 1060 connected cam elements 1061 , The individual cam elements 1061 are with the connection plate 1060 firmly connected, preferably welded, soldered or riveted. Both the connection plate 1060 as well as the individual cam elements 1061 can be manufactured inexpensively as stamped and bent sheet metal. Also possible would be a construction in which a complete cam unit 1062 is formed from only one piece of sheet metal and the cam elements 1061 in a single cam unit 1062 united. In particular, such a cam unit 1062 a jib 1063 and a recess 1064 for a path limitation.

20 shows a cam unit 1070 with an oil pan shell 1071 , At the oil pan shell 1071 is a steering shaft 1072 arranged. The cam unit 1070 is preferably in the oil pan shell 1071 guided. For this purpose, the oil pan shell 1071 in the transverse bulkhead corresponding guide surfaces. A holding plate 1074 prevents falling out of a guide surface. The holding plate 1074 Can be designed as a simple stamped and bent sheet metal part and is from below against the oil sump shell 1071 screwed. Furthermore, this plate still has a tab 1073 for mounting the connecting shaft 1072 on. Furthermore, on the oil pan top 1071 a servomotor 1075 arranged.

21 shows an oil pan top 1081 a servomotor 1080 , a connection plate 1082 the cam unit 1070 and a holding plate 1083 in a side view. The drive of the cam unit 1070 via the electric servomotor 1080 and one with the servomotor 1080 connected articulation shaft 1084 , The servomotor 1080 is preferably on the side of the sump upper part 1081 screwed.

22 shows a servomotor 1090 with a tilting eccentric 1091 , The drive of the cam unit 1070 via the electric servomotor 1090 , At the end of the connecting shaft 1092 is the tilting eccentric 1091 worked up or as an individual part with the connecting shaft 1092 connected. This tilting eccentric 1091 reach into the jug 1093 the cam unit 1070 and converts the rotational movement of the articulation shaft 1092 in a translational movement of the cam unit 1070 around.

As an alternative to an articulation by means of an eccentric, the conversion of the rotational movement into a translatory movement could also be realized by means of a pinion and a toothed rack. Another possibility of driving the cam unit would be an end-side drive by means of a linear actuator. Suitable drives are electric motors, preferably with a reduction gear, which are installed in other places on the engine, for example, as actuators for wastegate flaps on turbochargers, the swirl flaps and / or exhaust gas recirculation valves.

As an alternative to the electric motor, the lifting movement could also be generated directly by means of a magnetic actuator, for example by means of an actuator which is used in a similar form to electromagnetic valve trains. The Magnetaktuator would have the advantage of a very fast operation. Thus, it would be possible to complete the cam unit within one motor revolution or even faster.

Another possibility of driving the cam unit would be by means of a hydraulic or pneumatic actuator, preferably by means of a hydraulic or pneumatic linear cylinder. With the hydraulic drive, the necessary could be generated by the engine oil pump. With the pneumatic drive, the intake manifold vacuum could be used. However, this would only be available in the area of partial load. If you were to connect the pneumatic cylinder to a vacuum pump, the pneumatic energy would be available almost independently of the engine load. As another option, the boost pressure could be used for actuation.

23 shows an interaction between a switching element 1100 and a function area "forerun" 1101 , The cam unit should have a travel path which matches the axial travel of the switching element to be actuated. The entire axial travel of the switching element 1100 consists of a first portion of the through the functional area 1101 forcibly impressed and a second portion passing through the latching device 1016 is applied, together. In 23 is the orbit of the midpoint 1106 of the switching element 1100 located. The forced stroke 1102 should be at least as large that a ball of a latching mechanism as in example 14 as a locking mechanism 1016 is shown, the elevation between the valleys of a catch contour, as for example in 14 as a locking contour 1018 is shown, has overcome. This corresponds to at least half the total stroke of the switching element 1100 , It is safer when the forced stroke 1102 is larger, since it can happen that the Schaltlement not on the nominal point of view 1104 impinges on the functional area but afterwards. This occurs when the cam unit is not in its nominal operating position to the switching element due to unavoidable tolerances. The forced stroke 1102 should therefore be at least half the total stroke of the switching element 1100 plus an expected maximum cam tolerance margin 1105 correspond.

According to an exemplary embodiment, a total stroke of the switching element 1100 of 4 mm by the locking device 1016 be predetermined. A cam disc tolerance reserve can do this 1105 of 1 mm. Accordingly, the forced stroke should 1102 at least 3 mm. Such a design ensures that the switching element has been "pushed over" at least over the maximum of the elevation. The remaining distance of 1 mm is then applied by the spring-loaded ball.

In 23 is a first state 1108 of the switching element 1100 shown in which the switching element 1100 just the functional area 1101 leaves. At the next crankshaft revolution, the switching element has arrived in its final position. This has then between the dome 1103 of the switching element 1100 and the functional area 1101 a clearance of 1 mm, according to the exemplary embodiment. The in 23 marked distance 1107 between the upper dome 1103 of the switching element 1100 and the upper functional area 1109 should be calculated so that in the final state on both sides an equal distance 1107 established. This means a value of 2 mm for the exemplary embodiment. The necessary travel of the cam unit must thus the total stroke of the switching element 1100 correspond. In the event that the switching element before the nominal impact point 1104 impinges on the functional surface, the functional surface "backwards" is extended so far that the dome 1103 in the worst case, just hit the edge.

To ensure the lowest possible camshaft tolerance reserve 1105 to have to hold the cam unit should 1070 be aligned as precisely as possible to the connecting rod. For example, an underpass of the connecting rod can be realized. In another embodiment, an upper guide of the connecting rod is realized. For precise alignment of the connecting rod to the cam unit, an underpass of the connecting rod is provided in particular. Nevertheless, there remains a comparatively long tolerance chain, which is a minimally required cam disc tolerance reserve 1105 affected. In such a tolerance chain go above all the axial play of the connecting rod to the crankshaft, the axial play of the crankshaft for axial support, which can be arranged either in the upper or in the lower part of the crankcase, as well as the game, which results from the installation position sump upper part to crankcase, one. Preferably, the oil pan top is connected to the crankcase by pinning.

24 shows a connection between a cam unit 1110 and an oil pan shell 1111 , The path of the cam unit 1110 should be opposite the oil pan top 1111 have a Wegbegrenzung, preferably realized by a stop pin 1112 and a corresponding recess 1113 in the cam unit 1110 , 24 also shows a retaining plate 1114 as well as in 20 as a holding plate 1074 is shown.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• US 7434548 B2 [0003]
• DE 102005055199 A1 [0120, 0120]

Claims (15)

Reciprocating engine, which - at least one adjusting device ( 40 ) using engine forces of the reciprocating engine for adjusting an adjustable variable compression ratio, - a drive mechanism ( 41 ) for driving the adjusting device ( 40 ), wherein the drive mechanism ( 41 ) only on a connecting rod ( 42 ) or piston is arranged and at least one movable element ( 43 ), a single oil supply ( 44 ), at least one variable volume ( 45 ) for filling and emptying oil and at least one oil line ( 46 ) and - an oil supply system ( 47 ; 247 ; 347 ; 447 ; 547 ; 647 ; 747 ; 847 ), which has an oil reservoir ( 48 ; 248 ; 348 ; 448 ; 548 ; 648 ; 748 ; 848 ), a pressure generator, an oil connection ( 50 ; 250 ; 350 ; 450 ; 550 ; 650 ; 750 ; 850 ) between the oil reservoir ( 48 ; 248 ; 348 ; 448 ; 548 ; 648 ; 748 ; 848 ) and the pressure generator and an oil connection ( 51 ; 251 ; 351 ; 451 ; 551 ; 651 ; 751 ; 851 ) between the pressure generator and the oil supply ( 44 ) of the drive mechanism ( 41 ), characterized in that a common switch or circuit is provided which simultaneously actuates the respective activation mechanism of at least two, in particular of all the respective adjustment devices of the reciprocating piston engine, preferably the pressure generator as a pressure pulse generator ( 52 ; 252 ; 352 ; 452 ; 552 ; 652 ; 752 ; 852 ) and between the crankshaft ( 53 ; 253 ; 353 ; 453 ; 553 ; 653 ; 753 ; 853 ) and the oil reservoir ( 48 ; 248 ; 348 ; 448 ; 548 ; 648 ; 748 ; 848 ) is interposed and the drive mechanism ( 41 ) via a pressure pulse generator ( 52 ; 252 ; 352 ; 452 ; 552 ; 652 ; 752 ; 852 ) generated pressure pulse ( 54 ; 116 ; 216 ; 316 ; 416 ; 516 ; 616 ; 716 ; 816 ) via the oil supply ( 44 ) of the drive mechanism ( 41 ) is controlled. Reciprocating piston engine according to claim 1, characterized in that the oil supply system with a lubricating oil supply system ( 55 ; 255 ; 355 ; 455 ; 555 ; 655 ; 755 ; 855 ) is connected to the reciprocating engine, wherein the lubricating oil supply system ( 55 ; 255 ; 355 ; 455 ; 555 ; 655 ; 755 ; 855 ) at least one check valve ( 56 ; 256 ; 356 ; 456 ; 556 ; 656 ; 756 ; 856 ) in an oil line ( 57 ; 257 ; 357 ; 457 ; 557 ; 657 ; 757 ; 857 ) between a crankshaft bearing ( 71 ; 271 ; 371 ; 471 ; 571 ; 671 ; 771 ; 871 ) and an engine oil pump ( 72 ; 272 ; 372 ; 472 ; 572 ; 672 ; 772 ; 872 ) having. Reciprocating piston engine according to one of the preceding claims, characterized in that the drive mechanism ( 41 ) at least one movable element ( 43 ), which has a first position ( 58 ) and a second position ( 59 ), wherein the first position is associated with a first compression ratio and the second position is associated with a second different compression ratio from the first one and a switching back and forth of the element ( 43 ) by successive rectified by the pressure pulse generator ( 52 ; 252 ; 352 ; 452 ; 552 ; 652 ; 752 ; 852 ) generated pressure pulses ( 54 ; 116 ; 216 ; 316 ; 416 ; 516 ; 616 ; 716 ; 816 ) is controlled. Reciprocating piston engine according to one of the preceding claims, characterized in that the pressure pulse generator ( 52 ; 252 ; 352 ; 452 ; 552 ; 652 ; 752 ; 852 ) a stepped piston ( 60 ) and the stepped piston ( 60 ) to an engine oil pump ( 72 ; 272 ; 372 ; 472 ; 572 ; 672 ; 772 ; 872 ) of the reciprocating engine is hydraulically connected. Reciprocating piston engine according to one of the preceding claims, characterized in that the pressure pulse generator ( 52 ; 252 ; 352 ; 452 ; 552 ; 652 ; 752 ; 852 ) is designed as a pneumatic-hydraulic unit, which an air compressor ( 62 ; 262 ; 362 ; 462 ; 562 ; 662 ; 762 ), a compressed air tank ( 63 ; 263 ; 363 ; 463 ; 563 ; 663 ; 763 ) and an oil storage cylinder ( 64 ; 264 ; 364 ; 464 ; 564 ; 664 ; 764 ) with an air chamber ( 65 ; 265 ; 365 ; 465 ; 565 ; 665 ; 765 ), wherein the oil storage cylinder ( 64 ; 264 ; 364 ; 464 ; 564 ; 664 ; 764 ) is preferably designed as a pressure booster with different sized piston diameters. Reciprocating piston engine according to claim 5, characterized in that the air compressor ( 62 ; 262 ; 362 ; 462 ; 562 ; 662 ; 762 ) via an electric motor ( 66 ; 266 ; 366 ; 466 ; 566 ; 666 ; 766 ), a belt and / or wheel drive of the reciprocating engine is driven. Reciprocating piston engine according to claim 6 or 7, characterized in that the air compressor ( 62 ; 262 ; 362 ; 462 ; 562 ; 662 ; 762 ) with a compressed air brake system ( 67 ), wherein the built-up pressure within the compressed air brake system ( 67 ) represents a first compression stage, and the air compressor ( 62 ; 262 ; 362 ; 462 ; 562 ; 662 ; 762 ) is implemented as a second compression stage. Reciprocating piston engine according to one of claims 5 to 7, characterized in that the oil storage cylinder ( 64 ; 264 ; 364 ; 464 ; 564 ; 664 ; 764 ) a rolling diaphragm for sealing the air chamber ( 65 ; 265 ; 365 ; 465 ; 565 ; 665 ; 765 ) of an oil space of the oil storage cylinder ( 64 ; 264 ; 364 ; 464 ; 564 ; 664 ; 764 ) having. Reciprocating piston engine according to one of claims 5 to 8, characterized in that the reciprocating piston engine a filling valve ( 69 ; 469 ; 569 ; 669 ) for filling the oil storage cylinder ( 64 ; 264 ; 364 ; 464 ; 564 ; 664 ; 764 ) in an oil compound ( 50 ; 250 ; 350 ; 450 ; 550 ; 650 ; 750 ; 850 ) of one Engine oil pump ( 72 ; 272 ; 372 ; 472 ; 572 ; 672 ; 772 ; 872 ) to the pressure pulse generator ( 52 ; 252 ; 352 ; 452 ; 552 ; 652 ; 752 ; 852 ) having. Reciprocating piston engine according to one of the preceding claims, characterized in that a control mechanism ( 41 ) of a single connecting rod ( 42 ) or piston of the reciprocating engine via at least one valve ( 115 ; 215 ; 315 ; 815 ) and an oil compound ( 51 ; 251 ; 351 ; 451 ; 551 ; 651 ; 751 ; 851 ) with the pressure pulse generator ( 52 ; 252 ; 352 ; 452 ; 552 ; 652 ; 752 ; 852 ) is hydraulically connected and that a drive mechanism ( 41 ) of a single connecting rod ( 42 ) or piston of the reciprocating engine via a single valve ( 115 ; 215 ; 315 ; 815 ) is hydraulically controllable. Reciprocating piston engine according to claim 10, characterized in that each connecting rod of the reciprocating engine is hydraulically controllable via a respective individual oil storage cylinder. Method for controlling a plurality of a respective drive mechanism ( 41 ) of a connecting rod, which changes a compression ratio in a reciprocating piston engine, wherein the respective control mechanism of at least two, in particular of all respective adjusting the reciprocating engine are simultaneously actuated by a common circuit or switch, preferably with the following steps: a) generating a pressure pulse ( 54 ; 116 ; 216 ; 316 ; 416 ; 516 ; 616 ; 716 ; 816 ) by a pressure pulse generator ( 52 ; 252 ; 352 ; 452 ; 552 ; 652 ; 752 ; 852 ), the oil from an oil reservoir ( 48 ; 248 ; 348 ; 448 ; 548 ; 648 ; 748 ; 848 ) uses; b) Forwarding of the pressure pulse ( 54 ; 116 ; 216 ; 316 ; 416 ; 516 ; 616 ; 716 ; 816 ) preferably via a crankshaft ( 53 ; 253 ; 353 ; 453 ; 553 ; 653 ; 753 ; 853 ) of the reciprocating engine to an oil supply ( 44 ) of the drive mechanism ( 41 ); c) initialization of a movement of a movable element ( 43 ) of the drive mechanism ( 41 ) by the pressure pulse ( 54 ; 116 ; 216 ; 316 ; 416 ; 516 ; 616 ; 716 ; 816 ); d) changing the compression ratio of the reciprocating engine by the movement or a changed position of the element ( 43 ) and engine forces of the reciprocating engine. A method according to claim 12, characterized in that the compression ratio via the drive mechanism ( 41 ) only via a single oil supply ( 44 ) is switched with the following additional step in step c): c.1) changing the position of the movable element ( 43 ) of the drive mechanism ( 41 ) from a first position to a second position by a first pressure pulse ( 54 ; 116 ; 216 ; 316 ; 416 ; 516 ; 616 ; 716 ; 816 ); and the additional subsequent steps: e) changing the position of the movable element ( 43 ) of the drive mechanism ( 41 ) from the second position, reversing the travel preferably to the first position via a second pressure pulse ( 54 ; 116 ; 216 ; 316 ; 416 ; 516 ; 616 ; 716 ; 816 ); f) change of the compression ratio of the reciprocating engine by the changed position of the element ( 43 ) and the engine forces of the reciprocating engine. Method according to claim 12, characterized in that a drive mechanism ( 41 ) of a single cylinder of a reciprocating engine is controlled independently of the driving mechanisms of the other cylinders of the reciprocating engine with the following additional step before the step a): 0) storage of an amount of oil in the pressure pulse generator ( 52 ; 252 ; 352 ; 452 ; 552 ; 652 ; 752 ; 852 ), which is preferably two to three times as large as the amount of oil required for a simple switching of all the cylinders of the reciprocating engine from a first compression ratio of the reciprocating engine to a second of the first different compression ratio of the reciprocating engine; and subsequent steps after step d): g) measuring the compression ratio of a single cylinder by a controller; h) comparing the measured compression ratio in the cylinder against a target compression ratio in that cylinder; i) repetition of the activation of the activation mechanism ( 41 ) for controlling the variable compression ratio in that cylinder if the deviation of the measured compression ratio from the target compression ratio is outside a predefined tolerance range. Method according to one of claims 12 to 14, characterized in that in a exhaust system, preferably in an outlet channel of a cylinder, a thermodynamic variable, preferably an air ratio, is measured and depending on the measured value of the thermodynamic size of a comparison value, the height and duration of the Pressure pulse ( 54 ; 116 ; 216 ; 316 ; 416 ; 516 ; 616 ; 716 ; 816 ) generated by the pressure pulse generator ( 52 ; 252 ; 352 ; 452 ; 552 ; 652 ; 752 ; 852 ) is changed.

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