EP1996798B1 - Hydraulic circuit, in particular for camshaft adjuster, and corresponding control element - Google Patents

Description

The invention relates to a motor vehicle-hydraulic circuit, in particular with a camshaft adjuster, and corresponding controls.

In hydraulic circuits of motor vehicles, hydraulic pistons are used to change the position of a connected mechanical element, such as a camshaft. One type of hydraulic piston may be a rotary motor-type rotary piston or radial piston, also known as a hydraulic motor, which can rotationally change its position within a certain angular range.

The piston moves within a housing, the piston forms hydraulic chambers on both sides, which are changed in opposite directions. This means that when a hydraulic chamber increases due to a change in position of the hydraulic piston, the corresponding chamber opposite the piston is reduced to a corresponding extent, and vice versa. As is known, the hydraulic chambers are of a similar design, so that the volumetric growth of one hydraulic chamber contributes to the same volume reduction of the corresponding other chamber. In this case, changes in volume are equivalent in amount or even identical.

A very important hydraulic motor vehicle circuit is the camshaft adjusting circuit starting in the engine sump, which adjusts the relative position of the camshaft relative to a driving shaft, such as, for example, the crankshaft or a further camshaft, via corresponding valves and a pivoting motor-type camshaft adjuster. The adjustments are made towards an earlier or later time with respect to the rotational angle of the driving shaft or with respect to the position of the piston. Such a system, unlike, for example, closed systems with a single hydraulic circuit, as known motor vehicle transmissions are constructed, is considered to be an open system operating with variable volumes of oil because there are multiple hydraulic circuits in the engine sump starting in the internal combustion engine.

Other known hydraulic circuits in the motor vehicle may be, for example, transmission controls which are either supplied to the central, with engine oil Hang hydraulic circuit or an independent, self-contained hydraulic circuit.

Particularly in the case of multiple hydraulic loads due to a threaded hydraulic system, automobile manufacturers demand the least possible load, the hydraulic pump that must supply all consumers. As a result, the parasitic loads on the internal combustion engine are lowered, which in turn contributes to the increase in efficiency.

Numerous embodiments, such as the oversupply of hydraulic consumers can be reduced, is the US 2005/0072397 A1 removable, which primarily attaches to the flow rates of the hydraulic circuit. According to one aspect of the invention described therein, speed-dependent flow rates of a mechanically coupled directly to the internal combustion engine oil pump are reduced in volume by additional funding or storage facilities.

Another important requirement of internal combustion engine manufacturers is the desire to be able to install the fastest possible camshaft adjusters in the internal combustion engine.
In general, the adjustment of the camshaft adjuster is increased by correspondingly large oil flow rates. Many motor vehicle manufacturers require adjusters with adjustment speeds of 100 ° / sec. In the literature you will often find adjusters, the adjustment speed are given with a single extreme value. But important is the adjustment speed over all speeds of the internal combustion engine, which should be as constant or linear. Thus, partially punctual adjustment speeds of more than 200 ° / sec are described which, on closer examination, have a purely singular character in relation to the rotational speed. Looking more closely at the data, it can be seen that these figures often refer to high speeds with low oil temperatures. By installing a larger oil pump while you get a fast camshaft adjuster, but the efficiency and the efficiency of the internal combustion engine decreases.

From the publication EP 0 388 244 A1 a system is known which is completely closed with two antiparallel connections via a valve, the relative position of a driven shaft by oil compensation of a total of constant oil volume from a chamber to the second chamber adjusted to a driving shaft. The teaching of the publication, for example, in the main claim and the Figures 3 and 7 is to be considered rather theoretically, because well-known leak occur in the camshaft hydraulic circuit.

In the literature, in particular in the article "A camschaft torque acutated vane style VCT phaser" by the authors Frank Smith and Roger Simpson, reprinted as SAE article 2005-01-0764, for example, it is proposed to relieve the pump of the hydraulic circuit thereby, that the pump only compensates for leakages of the adjuster, while there is a normally closed, hydraulic compensation system between the two counter-rotating chambers of the adjuster. The adjustment speeds presented in the diagrams suggest that the presented system works only with correspondingly large amounts of oil in the hydraulic circuit of the phaser. In classic engines of small vehicles, especially in Western Europe and Japan, the system described is likely to find little application, because such engines are also to operate with significantly lower Befüllmengen (often less than 5 liters of engine oil). A patent belonging to the same category can be found in the US 5,657,725 to be beheld.

The use of the introduced from the camshaft on the camshaft adjuster torque for adjusting the camshaft adjuster to an early position is from the DE 101 58 530 A1 and the DE 10 2005 023 056 A1 known. While the DE 101 58 530 A1 wants to use the technology to get into the early position more quickly, when the engine drops from a hot run phase in a low speed range, wants the DE 10 2005 023 056 A1 especially in the event of a supply pump failure, ensure that the camshaft is turned into a position in which it is possible to continue operation in the early position. For this purpose uses the DE 101 58 530 A1 a check valve with a pressure compensation valve in the camshaft adjuster itself, while the DE 10 2005 023 056 A1 want to arrange several check valves around the pump around.

The DE 602 07 308 T2 proposes to use a valve which distinguishes between two states, namely between a high speed range in which an oil pressure actuated camshaft adjustment takes place, and a low speed range in which a camshaft torque actuated camshaft adjustment takes place. The changeover switch switches between the two states depending on the operation.

As can be seen, the prior art teaches the use of camshaft torques for certain operations and modes of operation. The hydraulic circuits have been designed accordingly for the task.

To improve the adjustment speed is out of the DE 102 05 415 A1 or her US Family Capital US Pat. No. 6,941,912 B2 It is known, based on Applicant's in-house developments, to interconnect a group of valves, in particular four piston-operated valves, to release a bypass line through which hydraulic fluid can be transferred from one chamber to the other variable-rate increase chamber. Otherwise, it is an open system, which is supplied from a feed pump. It can be seen from one of the exemplary embodiments that a bypass arrangement can be realized by means of the nested piston arrangement of the hydraulic separator. According to this embodiment, the bypass arrangement is separated from the switch disconnected independently arranged with a multi-piston forming valve group in the rear wall of the camshaft adjuster.

In the present invention, therefore, an approach was sought to design a hydraulic system that offers a high and almost constant adjustment speed, as independent of the operating parameters of the hydraulic piston, at the same time offers a good control quality, a small burden on the oil pump of the internal combustion engine and also for small volume engines, eg. B. 1.3 or 1.8 liter machines, can be installed, which have fewer Gaswechselventilrückstellfedern than, for example, the V6 engine of the technical article described above.

The control quality is specified in camshaft adjusters, inter alia in angular degrees in which the camshaft adjuster shuttles, although a defined, constant position acc. Pressurization from the supply pump is desired. The deviation from the theoretically set position in angular degrees is then called control quality.

Furthermore, the inventors set themselves the task to be able to use the system to be designed even in fully variable valve trains, which, for example, in the patent applications WO 2004/088094 . WO 2004/088099 and US Pat. No. 6,814,036 respectively. EP 1 347 154 A2 be described in more detail.

A suitable valve can be taken from claim 1. Advantageous embodiments can be taken from the dependent claims.

In contrast to the use of a pure alternating torque, which comes for example from the gas exchange valve return springs and the camshaft in a camshaft adjuster, or by a pure external adjustment by means of pressurized hydraulic medium, a hydraulic system is proposed according to the invention, which can get along with both swelling and with pure alternating torques , Depending on the load and reaction of the driven and displaced shaft, such as the camshaft, alternately swelling moments and alternating moments occur. The motor control unit serving to control the hydraulic switch, for example the camshaft adjuster valve, is no longer dependent on constantly introduced alternating torques, but in one embodiment must actively activate only a single valve while the remainder of the hydraulic circuit is operated passively.

In this context, alternating moments are moments on the hydraulic piston, which both temporarily have a positive, variable component and a temporary negative component. By contrast, swelling moments are those moments which, although they change in magnitude, remain over a longer period of several milliseconds in the same sign range of the torque characteristic.

On the motor vehicle hydraulic circuit with a counter-rotating hydraulic piston with at least two hydraulic chambers acts an external moment, which acts either changing or swelling. The hydraulic circuit performs by different pressurization, which is removable from a hydraulic pump, the counter-rotating hydraulic chambers by a change in position. In addition to a hydraulic Weichenverstellung, preferably embodied by a valve which directs the pressurization of the hydraulic medium to the piston, the negative portion of the alternating torque is used to change the hydraulic piston in position. The swelling part of the moment will be by other means, such as check valves, hidden. The selective use of moments, in particular by the release via check valves, leads to a linearization of the adjustment speed on the speed of the engine, while the continued use of the smallest possible Hydraulikversoraung from a pump for adjusting the piston ensures the high Verstellaeschwindiakeit even with pure Schwellanteilen the moment ,

According to one embodiment, hydraulic connection paths from one chamber of one type to the working connection for the other chamber type are respectively provided. This results in a hydraulic circuit with a valve. The valve may pass the hydraulic pressure, which is derivable from the negative portion of the alternating torque on the one working port for one chamber type via at least one check valve, to the second working port of the other type of chamber. It can be done alternately. Incidentally, the pressurization of the pressurized port is forwarded to the second working port. The alternate passage of the hydraulic medium is carried out from both the one chamber and the other chamber to the corresponding counter-rotating chamber.

If the motor vehicle hydraulic circuit is constructed in the context of a camshaft adjuster, the motor vehicle hydraulic circuit is an engine oil-operated hydraulic circuit of an internal combustion engine whose hydraulic piston is a pivoting motor-type or helical camshaft adjuster into which the torques of at least one camshaft are introduced.

The size of the gas exchange valve springs and their number has an influence on the frequency and type of introduced moments from the camshaft to the camshaft adjuster. A manufacturer of camshaft adjusters is asked to offer camshaft adjusters for internal combustion engines, which should be as universally applicable. Often a car manufacturer wants to use one and the same camshaft adjuster for different engines of different series. The manufacturer of the phaser, however, may make specifications regarding the hydraulic circuit, so that it is possible to improve the behavior of the camshaft adjuster by selecting a suitable valve or a suitable valve assembly and a phaser together with the hydraulic interconnection.

und $$\mathrm{P}=\frac{F}{\iint \partial x*\partial y}$$

In the case of the use of swivel motor-like camshaft adjusters instead of forces, the torque fluctuations, the alternating torque and the swelling moment, which are introduced from the camshaft to the phaser, closer considered, so that in these cases instead of the force is spoken of the moment. According to current knowledge of every physicist or mechanical engineer can be determined from the moment M, the force F, and from the force F, the corresponding hydraulic pressure P can be derived, where r represents the radius of the pivot motor-like camshaft adjuster and x and y describe the surface. The formulas for this are: $$\mathrm{M}=\int F*\partial r$$

and $$\mathrm{P}=\frac{F}{\iint \partial x*\partial y}$$

The function of the check valves can be referred to as a bypass, which feed only the negative part of the alternating force before the switch again. According to one embodiment, a suitable place of re-injection of the P-port, the termdruckpeaufschlagte connection of the switch. The check valve or if there are a plurality of non-return valves, the check valves is then arranged so that only in the direction of the pressure side of the switch, a passage of the hydraulic pressure originating from the chambers of the piston, is made possible. Through the use of Rückschlaasventilen in the context of bypass construction, a technically elegant solution has been found, such as with the teaching that in the DE 10 2005 013 085 is described in more detail, reliable long-term functioning check valves with few components Cantridge valves can be constructed.

The divert activity in the automotive hydraulic circuit functions when the amount of pressure resulting from the alternating force exceeds the other pressure in one of the supply lines to the increasing chamber of the piston and then releases the check valve provided for directional determination. The Rückschlaasventile may be arranged so that the two hydraulic chambers of the piston are indirectly connected. In this case, make a connection over the switch to get from one chamber to the other. Another variant is the direct connection, in which when opening the check valve, a direct hydraulic Connection is created from one hydraulic chamber to the other. Which of the two variants is to be selected depends on the respective framework conditions for the motor vehicle hydraulic circuit to be created. If the cylinder head, in which the switch is arranged, provides enough space to build multiple hydraulic lines, an alternative embodiment can be used to design an indirect connection via the hydraulic switch. Should it be desired to allow the fastest possible transhipment, if possible with little leakage, an immediate connection via the non-return valves from one chamber of the piston to the other chamber should be chosen.

• eine hydraulische, eine mechanische, eine mechanisch-hydraulische Kombination, eine elektrische, eine magnetische oder eine elektro-magnetische Kombination. Hydraulische Vorspannungen werden gewählt, wenn mit mehr Hydraulikmengen gearbeitet werden kann. Mechanische Vorspannungen werden in der Regel einmal eingestellt, sie sind danach nicht weiter zu kalibrieren. Elektrische und magnetische Vorspannungen können gut auf das Kraftfahrzeussteuergerät der Verbrennungskraftmaschine geleitet werden. Hierdurch wird eine Software-mäßige Beeinflussung ermöglicht.

The hydraulic switch is preloaded. Suitable solutions for generating the bias voltage may be:

• a hydraulic, a mechanical, a mechanical-hydraulic combination, an electrical, a magnetic or an electromagnetic combination. Hydraulic preloads are selected if more hydraulic power can be used. Mechanical preloads are usually set once, then they should not be further calibrated. Electrical and magnetic biases can be well directed to the motor vehicle control unit of the internal combustion engine. This allows a software-influenced influence.

According to an embodiment of the present invention, one of the check valves is arranged in a blocking direction so that a connection can be established from the hydraulic-pressure input side of the hydraulic switch to an output side of the hydraulic switch. The output side of the hydraulic switch is according to this embodiment with one of the hydraulic chambers of the piston in connection. The proposed embodiment is a fairly compact variant. It impresses with its simplicity and simplicity.

According to another embodiment, the directional choice of the hydraulic piston can be adjusted by a hydraulically controlled valve. In the context of hydraulic speeds, a hydraulically very stable system results from its feedback looping.

According to a further advantageous development, a hydraulically controlled valve serves to pressurize one of the hydraulic chambers to the other Hydraulic chamber to connect. Here, too, the hydraulic dependencies ensure stabilization of the hydraulic circuit.

With the unpublished knowledge from the DE 10 2005 013 085 A1 It is possible to create an integrated component which connects the non-return valves with the hydraulic diverter through built-in belts.

Even further to integrate is the entire arrangement, when the valve and the camshaft adjuster are combined to form a camshaft adjuster with central valves. The central valve is arranged either in the axial center of the camshaft adjuster or as an axial extension of the camshaft adjuster. The central valve or assembly includes a pressure reducing valve, a check valve or a two-way valve. With the disclosure of this invention, it is possible for an automotive technician or hydraulician to select the appropriate components to selectively implement the invention with, for example, a pressure reducing valve and three check valves in the phaser.

After a favorable development of the hydraulic circuit may comprise a partial hydraulic circuit, which is composed of three hydraulically controlled valves. The three valves take on the task alternately obstruct two supply lines and two return lines or switch freely.

The hydraulic circuit can be designed so that the essential component is a valve. It is then a valve for a motor vehicle hydraulic circuit. The valve is intended, in particular in the case of a pivoting motor-type camshaft adjuster, to pass through the torque fluctuations, which can occur both as alternating moments and as swelling moments, with the hydraulic pressure which is transmitted from the pressure source, which is transmitted to the pressurized connection of the valve. A typical cam phaser valve may be a four port valve. A connection is the connection that is switched directly or indirectly to the permanent pressure sources. It is the P port. Another connection is the tank connection, which usually leads into the engine sump. Working connections, which lead to the chambers of the hydraulic piston, are alternately switched through or interrupted depending on the switching position of a hydraulic piston within the valve. Without torque fluctuations that leads Valve the hydraulic pressure temporarily in one of the chambers of the swing motor, in the hydraulic circuit creates another hydraulic pressure, which comes from the negative portion of the alternating torque. The hydraulic pressure resulting from the negative portion of the alternating torque is always at least via a check valve ausleitbar. The discharged pressure is passed on to the second working connection. The described condition is a more unusual condition because most of the time the pressurization from the pressurized port of the hydraulic diverter or valve is passed to the appropriate service port. There is a wider use of pressures within the hydraulic circuit beyond the steady-state pressure. The bypass line resulting from the check valve takes advantage of the negative moment, while the standard adjustment is ensured by the selected standard position of the hydraulic piston. In addition to an advantageous energetic use of additional pressure resources, the feedback quality and even the adjustment speed are evened out or improved by this feedback.

In particular, for passing the negative portion of the alternating torque two check valves are used. The check valves are arranged to prevent hydraulic fluid flow from the pressurized port of the valve on the working port when the pressure resulting from the amount of the negative portion of the alternating torque, calculated by the above formulas, is absolutely greater than the pressure of the pressurized port. The valves work as a directional drainage, so to speak. With this approach, valves with two switching states apply as check valves according to the invention, if they are to realize the same function. Instead of a particularly advantageous band, technically subordinate solutions can also be chosen without falling outside the scope of equivalence or the meaning of the term check valve.

A suitable measure is to bias the valve in particular with a spring and build the entire valve as a cartridge valve. The cartridge valve is called a camshaft cartridge valve for a phaser. Particularly suitable are check valves that represent a kickback strap. The band is shaped into a ring. The self-holding of the band, the valves open in one direction and close in the other direction. The entire cartridge valve thus forms an integrated component with non-return valves. All cross connections within the cartridge valve are realized by transverse bores and recesses in the sleeve and in the piston.

The hydraulic piston can assume two or three switching positions. Actually, there are physically switching conditions. The valve is designed as a directional control valve. In the first position, which results from a bias, but does not require active control of the piston, there is an open position. It is a parallel connection. A parallel connection is understood to mean that the pressurized connection P leads to the first working connection A. The second working connection leads to the tank connection. If there is a connection from the P port to the second port B, and a connection from the first working port A to the tank port T, it is spoken of a cross-connected open position. The open position in parallel connection and the open position in cross-connection represent two of the two or three existing. The third position, may be a broken or closed position. It can be arranged on the piston so that the interrupted position is between the first and the second open position. Of course, valves can be used which have more than three positions along their piston.

According to one embodiment, the first check valve is arranged so that pressure peaks of the first working port are passed through the check valve. Meanwhile, the second check valve is arranged so that pressure peaks of the second working port can be passed through this check valve. A third check valve is designed as a pump protection valve. To protect the pump one or two check valves in the reverse direction, so to speak contrary, introduced into the valve. Thus, only one of the two paired check valves can open. The valve can be installed in the cylinder head of the internal combustion engine or in the camshaft adjuster itself.

Contrary to known bypass implementations in which nested piston arrangements are to be constructed, in the present case a bypass line is routed via the switch or a separate valve. This implementation reduces the component cost considerably and ensures easy to implement piston assembly within the valve. Without realizing a slide in a slide, as already explored in other in-house solutions, is a system has been created that can be passively addressed. The system works without external influence, whereby the system can also be realized in such a way that, as desired, an external influence, e.g. B. via a separate control valve, is possible. The absolute amount of pressure peaks resulting from the force or the moment has no influence on the concrete controllability. The fact increases the control quality. Also, the pressure differences in the system of subordinate importance. For the purposes of this invention, as a check valve in addition to the previously disclosed, any other suitable arrangement understood that has the result of a directional influence.

The present invention can be better understood with reference to the embodiments described in more detail below, but to which the invention is not limited. This shows
FIG. 1 a torque characteristic, starting from which the inventors to the embodiments of the FIGS. 2 to 6 a hydraulic circuit have arrived, and
FIG. 7 shows a common camshaft adjuster with axial extension of the central axis for receiving a partial hydraulic circuit, and
the FIGS. 8a to 8c represent a possible valve with check bands in three different positions,
the FIGS. 9 to 12 disclose further suitable embodiments for a hydraulic switch according to the invention, and
FIG. 13 represents a measurement or computational protocol of various inventive, here disclosed systems, compared to a classical, known system.

As in FIG. 1 can be seen, fluctuate the moments, which, as shown for example stylized, can be measured on the camshaft adjuster. Time is plotted on the X-axis, in this example 40 ms. On the Y-axis the moment is plotted in orders of magnitude in Nm. It can be seen that the moment is not constant, but changes almost permanently, due to vibration behavior, position of the camshaft, ignition timing of the internal combustion engine, opening points of the gas exchange valves, among others. The total moment M is composed of a negative portion of mouth and a positive portion of M +. In an internal combustion engine, the conditions also occur that there is only one swelling moment, then there is no change of sign. Thus, in the case of a threshold torque, only the (M +) or (M-) characteristic is measured at the phaser. During operation In the internal combustion engine, both phases of a swelling moment (only M + or only M-) occur as phases of an alternating torque M, in which both negative and sometimes positive components can occur. As long as the stage remains in the swelling state, the moment (or the force) can not be used to improve the control quality. However, with a change of sign of the moment now the opposite moment can be used successfully. It is therefore desirable to have a circuit that can use the opposite moment as effectively as possible without actively influencing itself, so that the pressure 250 can be discharged therefrom.

In the FIGS. 2 to 6 different embodiments of the invention are disclosed,
where it depends on the concrete conditions in the design of the motor vehicle hydraulic circuit, in particular the camshaft hydraulic circuit, which can be applied to the illustrated hydraulic plans. Similar components or components with similar functions are in all embodiments of FIGS. 2 to 6 have been listed with the same reference numerals. For readability reasons, not all similar parts are named individually in each embodiment, but for a better understanding reference is made to similar embodiments.

In the embodiment according to FIG. 2 is a motor vehicle hydraulic circuit 1 with a hydraulic piston 3, which may be a camshaft adjuster 100, shown. A camshaft adjuster 100 has at least two chambers A and B. As a rule, these chambers occur several times alternately. Two supply lines 28, 30 extend from the secondary side of the hydraulic switch 10 to the camshaft adjuster. The lines can be selected arbitrarily short or long, it depends on whether the hydraulic switch 10 is located far away at another location in the internal combustion engine, or whether the switch 10 and the camshaft adjuster 100 are integrated into one component. On the primary side, the hydraulic switch 10, which is spring-biased by the spring 32, and is electrically adjustable via the electrically controlled plunger 64, a pressurized port P and a tank port T, which leads into the motor sump 7. At the pressure port P, the pressure supply line 34 leads. On the secondary side of the hydraulic switch 10 at the working ports A1, B1, a first and second return line 16, 18 are connected, for example, by means of branch lines or cross-drilled lines. The first check line has a first return valve 12, the second check line 18 has a second check valve 14. The check valves lead to the pressure supply line 34. The first check line 16 acts on the first working port A1, the second check line 18 acts on the second working port B1. In the pressure supply line 34, a summation point is present, on which lead both the check valves 12, 14 and a pump protection valve. The pump protection valve 44 and the check valves 12, 14 are arranged with respect to the node unlocking. On the supplying side to the pump protection valve 44, a further pressure supply line 36 is provided, which is in communication with the hydraulic pump 5. In the present example, a 4/3-way valve 60 has been selected, which has an opening position in Kneuzverschaltung 50, a blocking position 52 and an open position in parallel connection 54. Without energization of the electrically controlled plunger 64, the spring 32 presses the hydraulic piston of the valve 10 in the open position in parallel connection 54. Alternatively, a first other position, depending on the design of the valve can be selected. If the pump 5 operates properly, the pump protection valve 44 opens in the hydraulic oil-free state and hydraulic medium flows out of the motor sump or oil pan 7 via the valve 10 into the first hydraulic chamber A, which increases and thereby reduces the second hydraulic chamber B. When the electrically controlled plunger 64 adjusts the hydraulic piston of the valve 10 and the open position is cross-connected 50, the hydraulic medium from the chamber A via the working port A1 to the tank port T is discharged, while new hydraulic medium, conveyed by the hydraulic pump 5, in the second Hydraulic chamber B is initiated. The hydraulic chamber B thereby increases, while the hydraulic chamber A is correspondingly reduced in size. Experienced the camshaft adjuster in addition to the normal adjustment a torque or force, and amplifies this introduction the adjustment, the respective check valve 12, 14 is opened. By an increasing pressure in the pressure node locks the pump protection valve 44 while the check valve 12 or the check valve 14 is opened by the introduction of force. Due to the hydraulic routes there is no instantaneous but almost immediate alternation between the types of valves.

A further embodiment of a hydraulic circuit according to the invention is in FIG. 3 to see. In this embodiment, a valve 10 has been selected as a hydraulic switch, but which is directly via a pressure supply line 36 to the hydraulic pump 5 in conjunction, while another port of the valve 10, a 4/3-way valve 60 is on the motor sump 7 leads. The 4/3-way valve 60 has a first state, the open position in parallel connection 54, which is occupied by a spring bias of the biasing spring 32 in the de-energized or low-energized state of the electrically controlled plunger 64, a blocking position 52 and an open position 50 in cross-connection. On the secondary side, the valve is guided on non-return valves 44, 46, which operate as pump protection valves, on one side and on hydraulically controlled tappet connections 66 of a further valve, which is a 4/2-way valve 62 with two positions. The throttle 38, 40 are supply chokes. The connection through the supply chokes 38, 40 from the valve 10 via distribution lines 70, 72. The pump protection valves 46, 47 have together with check valves 12, 14 to a P port of the 4/2 Directional valve 62. The four ports of the valve 62 are the P port for the pressure supply, the T port for the tank, a first working port A1 and a second working port B1. The working ports A1, B1 lead via supply lines 28, 30 to the hydraulic chambers A, B of the hydraulic piston 3 and the camshaft adjuster 100, which are mechanically fixedly connected to the camshaft 102. The hydraulic chambers A, B are also connected to non-return lines 16, 18, in which the non-return valves 12, 14 are installed opposite to each other. Leckagesrosseln 42 in the supply lines point to the trough in the motor sump 7. The hydraulic circuit 1 thus includes four check valves in addition to a 4/3-way valve 60 and a 4/2-way valve 62, the 4/3-way valve is mechanically biased and electrically adjustable and the 4/2-way valve 62 has a plunger 66 hydraulically clamped on both sides. About the switch 10 and its three positions 50, 52, 54, the position of the camshaft adjuster is selected. If the selected early or late position of the camshaft with respect to the crankshaft or another camshaft is set, the valve remains in the blocking position 52. The hydraulic circuit beyond the supply throttles 38, 40 is decoupled from the hydraulic pump 5. The pump protection valves 44, 46 remain in the locked state. By integrating the camshaft adjuster with the subhydraulic circuit beyond the supply throttles 38, 40, almost no leaks via the leakage throttles 42 occur due to the blocking of the pump protection valves. When an input of an external torque of the camshaft 102 to the camshaft adjuster 100 occurs, one of the two check valves 12, 14 opens and provides for a reverse transfer of the hydraulic fluid from one chamber to the other chamber. About the 4/2-way valve 62 and the set by the hydraulic bias ram position results in a possible hydraulic unloading one of the two chambers A, B.

The FIGS. 4 and 5 show two quite similar, inventive embodiments of a hydraulic circuit 1 with a camshaft adjuster 100, which is shown as a hydraulic piston 3. The hydraulic circuit 1 in the FIG. 4 schematically shows a hydraulic circuit for a hydraulic piston 3 and a camshaft adjuster 100, which moves the camshaft 102 in a relative phase. The camshaft adjuster 100 has a plurality of opposing chambers A and B, which can be hydraulically loaded to different pressure levels via the supply line 28 for the hydraulic chamber B and the supply line 30 for the hydraulic chamber A to a hydraulic medium to the camshaft 102 in an early or a To adjust late position. A supply line for a plurality of hydraulic chambers A, B reduces the leaks and thus the pressure losses in the system of the hydraulic circuit 1. From the output-side terminals A1 and B1 in the supply lines 28, 30 have check lines 16, 18, in the check valves 12, 14 are installed in the reverse direction to allow a passive, automatic transfer from a chamber to the corresponding counter chamber. The hydraulic switch 10 is a biased with a spring 32 4/2-valve that can take a changing position between an open position in Kreuzverschaltung 50 in the idle state and an open position in parallel connection 54. The plunger of the valve is actuated hydraulically via a pressure reducing valve 22 or a similarly acting second pressure reducing valve 24. The rotary unions in the example after FIG. 4 are represented by the supply chokes 38, 40 which are arranged between the pressure generator, the hydraulic pump 5, and pressure reducing valve 24 on one side and the switch with the connected supply lines 16, 18, 28, 30 and the camshaft adjuster 100. Reflows of the system are at the pressure reducing valve 24 (embodiment of the FIG. 4 ) or pressure reducing valve 22 (embodiment of the FIG. 5 ), returned to the leaks 42 and the hydraulic switch 10 in the trough 7 of the tank of the engine sump. The pressure reducing valve 24 may be biased by a spring 33. The check valve 44 protects the pump 5. Especially the embodiment according to FIG. 4 integrated components such as the hydraulic switch 10, the 4/2-valve, and numerous check valves 12, 14, 44 in the camshaft adjuster, preferably on the camshaft remote side.

In the embodiment of FIG. 4 is the hydraulic switch 10 as a 4/2 valve, also referred to as 4/2-way valve, which is biased on one side by the biasing spring 32, shown. The two states of the 4/2-way valve 62 are the open position in parallel connection 54 and the open position in Kreuzverschaltung 50. The plunger of the valve 62 is a hydraulically controlled plunger 66. The P port opens into the oil pan 7 of the internal combustion engine. The two working ports A1 and B1, which lead via the two supply lines 28, 30 to the hydraulic chambers A, B of the hydraulic piston 3 are returned via the non-return lines 16, 18 with the two check valves 12, 14 to a hydraulic summation point of the pressure supply line 34, the to the P port of the 4/2-way valve 62 has. In the hydraulic circuit of the hydraulic circuit 1, a further check valve 44 can be seen, which is arranged as a pump protection valve camshaft adjuster side before the leakage throttle 42 and the supply throttle 38 in the pressure supply line 36. From the pressure supply line 36, a distribution line 70 leads to the pressure reducing valve 24, which is held biased by an adjustable biasing spring 33 in a rest position. Both the distribution line 70 and the pressure supply line 36 are supplied by the hydraulic pump 5. The pressure reducing valve 24 is arranged on the engine block side, hydraulically following in the direction of the hydraulically controlled plunger 66 acts a supply throttle 40 and a Leckagesrossel 42. The Leckagesrossel 42 also open into the oil pan 7. The hydraulic circuit 1 thus has four points at which oil in the Hydraulic trough 7 can disappear: the 4/2-way valve 62, behind the first supply throttle 38; behind the second supply throttle 40, in each case via the leakage throttle 42; on the Druckneduzierventil 24. The 4/2-way valve 62 has only two positions, it eliminates the blocking position 52. If a moment is introduced to the camshaft adjuster 100, so that the hydraulic chamber B and the hydraulic chambers B decrease, the excess hydraulic fluid on the Feed line 28, the check line 18, the check valve 14 introduced into the summation point of the pressure supply line 34. Approximately at the same time closes the pump protection valve 44, and thus disconnects the hydraulic pump 5 from. The pressure peak can not penetrate damaging to the hydraulic pump 5, but is directed via the 4/2-way valve 62 and the hydraulic switch 10, depending on the position of the hydraulically controlled plunger 66 either in the chamber A or back into the chamber B. Thus, the control quality can be adjusted via the setting of the pressure reducing valve.

From the FIG. 5 is a very similar hydraulic circuit 1 as after FIG. 4 can be seen, a difference, the pressure reducing valve 22 is the one-sided spring biased over the Biasing spring 32 is, and can be electrically adjusted, in which the electrically controlled plunger 64 is addressed. Again, the hydraulic circuit reacts similarly to the description FIG. 4 with the exception that a valve position can be selected electrically from the vehicle control unit or the engine control unit. For the remaining identical components of the hydraulic circuit 1 is to the description of the figures FIG. 4 directed.

FIG. 6 shows another hydraulic circuit 1 according to the invention, which can be arranged as integrated components in the camshaft adjuster 100 as similar to that in the construction example according to FIG. 7 is disclosed. On the basis of rotary unions, which are shown as supply reactors 38, 40 with their associated, but often unwanted, leakage throttles 42, to the oil pan 7, the skilled person will recognize that in the present embodiment FIG. 6 except for the hydraulic switch 10, all components are installed in the camshaft adjuster 100. Of the hydraulic switch 10, which is a 4/3-valve with a spring preload for the defined rest position intake by the spring 32, lead to the camshaft adjuster 100, two distribution lines 70, 72, which in the camshaft adjuster 100 in two control lines 74, 76 before divide the check valves 46, 47 and two weiteiführenden lines. The 4/3-valve has an open position in Kreuzverschaltung 50, an open position in parallel connection 54 and a blocking position 52, wherein in the rest position, the open position is taken in parallel connection. Due to the hydraulic coupling between the valves 26, an inflow direction from the pressure supply of the hydraulic pump 5 into one of the chambers A, B of the camshaft adjuster 100 is alternately opened, while the other valve allows a discharge direction to the trough 7. The pressure compensation valve 56 is hydraulically clamped on both sides, so that depending on the supply position of the switch 10 one of the two lines 16, 18, which are also part of the check lines, the pressure-supplied chamber A, B can switch. The check valves 13, 15 together with the pressure compensating valve 56 release at hydraulic pressure over the supply pressure in the lines to the chambers a hydraulic path to allow discharges under pressure or momentum pulses from the camshaft from the reducing chamber in the enlarging chamber. In the FIG. 7 a constructive variant of the hydraulic circuit 1 of a camshaft adjuster 100 according to the invention with a camshaft 102 is shown. In the direction opposite to the camshaft, there is an axial extension 20 The rotor 108 merges into a rotor bearing 114, which is designed with a smaller diameter than the rotor 108 with its wings 104 and the axial extension 20. In the rotor bearing 114 rotary unions are integrated, the are shown in the schematics as supply chokes 38. The openings of the rotary unions, the lagestarren rotor bearing 114, go into oil passages, which are the control lines 74, 76 and the supply lines 70, 72. Some supply lines and control lines turn away from the wings 104 and lead first into the axial extension 20. The axial extension 20 is cap-like designed as a cylindrical, circular construction section, the approximately centrally, preferably arranged in the center of gravity of the rotor 108, provides space to include such components as check valves 46, 47 and two-way valves 26. Gem. Hydraulic plan 1 of FIG. 6 Lines from the cap to the wings 104 and the chambers A, B. In some wings 104 check valve 13, 15 are arranged, the Umladestrecken from the chamber of the first type to the chambers of the second type of the camshaft adjuster 100 respectively, in particular together with the pressure compensation valve 56, release. In other wings 104 Veririegelungsöffnungen 106 can be arranged. A third type of wing has no other functions, it is designed massive. When the wings 104 strike against a side wall of the webs 110, the term "beating" being understood to mean that there is no actual contact due to a damping hydraulic chamber 116 and a dirt collecting area 118, one of the chambers, e.g. B. the chamber A, in its maximum extent. In the case of blade positions deviating from the maximum deflection, the hydraulic medium of one chamber type, for. B. chamber type B, in the chambers of the other type, for. B. chamber type A, via the associated check valve, z. B. check valve 15, are reloaded by the non-return valve yields the overpressure and thus clears the way, optionally via a pressure compensation valve 56, which may be, for example, in the axial extension 20, the deflected pulse from the camshaft 102 and its gas exchange check valves (not shown ) to use the energy in the hydraulic fluid to improve the control quality.

The further embodiment variant for a hydraulic piston 3, in particular a camshaft adjuster 100 with a camshaft 102, acc. of the FIG. 6 The supply chokes 38, 40 and the leakage chokes 42 are above the hydraulic switch 10, in the present example a 4/3-way valve 60 is shown. Normally, the position of the camshaft phaser 100 is adjusted by the electrical driving of the electrically controlled plunger 64 of the 4/3-way valve 60 against the biasing force of the biasing spring 32. Depending on the selected position, opening position in Kreuzverschaltung 50, blocking position 52 and open position in parallel connection 54, the pressure on the hydraulic medium from the hydraulic pump 5 in the hydraulic chamber A or in the hydraulic chamber B of the camshaft adjuster 100 via one of the two hydraulically controlled
Two-way valves 26 are routed. The two two-way valves 26 are alternately on and are in the passage position. If a hydraulic passage takes place through the one two-way valve, then a hydraulic lock by the other hydraulic valve takes place at the same time. To adjust the position of the plunger serve the control lines 74, 76, which are each connected to a distribution line 70, 72. The control line 74, 76 are connected in front of the pump protection valves 46, 47 and behind the supply throttles 38, 40. The pressure compensation valve 56 is also a two-way valve whose piston is clamped by the control line 74, 76 on both sides. Depending on the pressure conditions in the control lines, a connection via either one return line 16 or the second return line 18 takes place. On the other side of the pressure compensation valve 56, two antiparallel-connected check valves 13, 15 are arranged, the pressure peaks from the hydraulic chambers A and B or multiply A and B of the camshaft adjuster 100 directed to reload into the respective other chamber. The three valves 26 and 56 are installed together with the check valves 46, 47, 13, 15 camshaft adjuster side. As a hydraulic switch, a common 4/3-way valve 60, which is familiar to any expert used. The control quality improvement takes place via the camshaft adjuster, in particular via the non-return valves 13, 15 and the associated hydraulic switches.

FIG. 7 shows a complete structural implementation of the camshaft adjuster side portion of the hydraulic circuit 1 of FIG. 6 , In the camshaft adjuster 100 is a rotor 108 can be seen, the axial center is cylindrically elongated to accommodate the hydraulic arrangement of the valves 26, 56, 46 and 47 can. The rotor 108 moves in a pivoting manner in its stator 112. Components are introduced in the blades 104 of the rotor 108. Two of the wings 104 have the check valves 13, 15. A third wing has a locking aperture 106 for a known locking pin, such as shown in FIG DE 10 2005 004 281 A1 (Hydraulic Ring GmbH) known. In the rotor 108 of the Camshaft adjuster 100, numerous channels are provided to install the check lines 16, 18, the control lines 74, 76 and the Venteilleitunaen 70, 72 in the rotor 108. The pump protection valves 46, 47, the two-way valves 26 and the pressure compensation valve 56 are arranged in the axial extension 20.

Instead of the arrangement of the check valves and the auxiliary valves in the camshaft adjuster 100 itself can be a large group of functionality in a valve 200 according to the FIG. 8a to FIG. 8c will be realized. The constructively illustrated valve of FIG. 8 a is similar to a schematic representation of FIG. 9 , The FIGS. 8a to 8c map the same valve with different plunger and piston positions in sectional drawings. The valve 200 comprises a magnetic part 218 and a hydraulic part 220. To realize an embodiment variant of the invention, a hydraulic part 220 has been adapted to a known magnetic part 218. The selectively hydraulically or electrically controlled plunger, here, for example, an electrically controlled plunger 64, moves the hydraulic piston 202 against the biasing spring 32. The biasing spring 32 is oil-filled, through which the oil flows to the trough 7 via the port T. The oil enters the The connections for the hydraulic chambers A, B have in each case two through openings A 1 and B 1. One of the existing openings in the sleeve A1, B1 is underlaid with a band-shaped check valve 204, 208. Due to the discharge edges on the hydraulic piston 202 alternately one of the openings is switched through. At the approximately centrally existing P-connection of the hydraulic part 220 of the valve 200, a filter 216 is arranged outside the sleeve 210, preferably permanently inserted, under which a further band-shaped ring 206 is placed, which also serves as a check valve like the two belts 204, 208 works. At a pressure spike across port A on the band-shaped ring 208, the check valve clears the path to the hydraulic piston 202, while the pump protection valve 404, consisting of the band-shaped ring 206, decouples the pressure source at the port P. The bands 204, 208, 206 are placed below the surface 212. Instead, depending on the position of the hydraulic piston 202, which is recessed along a substantial portion of its outer radius to form a continuous channel, the pressure peak can be reloaded from port A to port B. This very compact realization of a valve 200, schematically in FIG. 9 shown, shows an elegant realization of the ereindung in the form of a cartridge valve 214, the well-known Openings of cylinder heads of conventional internal combustion engines can be screwed.

The 4/3-way valve 62 of FIG. 9 can with reference to the FIGS. 2 to 6 in which similar parts have already been described, are easily understood by consideration, if any FIG. 8a to FIG. 8c is involved.

FIG. 10 discloses a 4/3-way valve 60 with the four ports P, T, A1 and B1. The three states, the open position in Kreuzverschaltung 50, the blocking position 52 and the open position in parallel connection 54. On one side, the valve is spring-biased by the biasing spring 32. The piston of the valve can be controlled by the electrically controlled
Tappet 64 are moved against the spring. With the knowledge of how non-return valves 12, 14 and pump protection valves 46, 47 can be realized by means of belts 204, 206, 208, a similar implementation as in FIG FIG. 8 due to the valve shown schematically in FIG FIG. 10 possible. Pump protection valves 46, 47 and the check valves 12, 14 have in opposite directions of flow. The check valves 12, 14 establish a connection between the terminals A 1 and B 1, when on the non-pressure-supplied side, but the pressure-relieved side T, a pressure peak occurs. The pump protection valves 46 or 47 close at that moment. The hydraulic source, for example in the form of the hydraulic pump 5, is decoupled and a compensation takes place between the chambers A and B of the camshaft adjuster 100 via one of the non-return valves 12, 14.

The 4/3-way valve 60 with the biasing spring 32 and the electrically controlled plunger 64 of the FIG. 11 is similar to the valve of the FIG. 10 , wherein the flow direction limiting unilaterally opening valves 12, 14 and 44 have been removed from the actual piston portion 202 and apply as the valve upstream. It will be appreciated that such a hydraulic piston 202 must provide more cross-links between the ports A1, B1, P and T. In the connection forming positions, the first and the third state, the P-terminal is led to at least two output-side terminals. Two further connections, a P and a T connection, are also routed to the other side of the valve or to the working connections A1, B1.

In the FIG. 12 Also, a 4/3-way valve 60 is shown, the check valves 12, 14 have not been positioned on the working port side, but are provided on the pressure supply side of the terminal P. Becomes FIG. 11 With FIG. 12 compared, it can be seen that the otherwise selected arrangement of the check valves, while maintaining the pump protection valve 44 at the P port, otherwise internal bridging over the edge selection of the hydraulic piston 202 of the valve 200 result. The valve shows, in each case viewed from the working ports A1, B1 ago, a double-connected connection to the ports P and T. Here, then, the open position in Kreuzverschaltung 50 and the open position in
Parallel connection 54 find in individual positions next to the blocking position 52. On the realization FIG. 11 the positions defined above are not so directly applicable.

The FIG. 13 represents the control deviation of a classic camshaft adjuster system (top characteristic curve) to the different systems according to the invention. The control deviation is noted on the y-axis. The engine speed is noted on the x-axis. There are various operating speeds of the internal combustion engine, namely about 750 rev / min, 1000 / min, 2000 rev / min and 4000 rev / min, mapped. Only at relatively high speeds does the deviation differ with respect to the camshaft to just 2 ° relative to 1 ° in the other cases. Without feedback via check valves in the reverse direction, the control deviation remains at values as high as 6 °, for example.

The presented teaching shows various embodiments, as can be constructed by means of conveniently placed check valves within a camshaft adjuster or a camshaft adjuster and some non-return lines a passively operating camshaft adjuster system, which stabilized by rapid transhipment, caused by introduced torques or induced external forces, the camshaft adjuster system as a whole. Only a small number of moving parts is needed. The absolute pressure values are subordinate. It is worked with relative pressure differences compared to the pressure supply. Due to the short ways, especially in an integration or partial integration in the camshaft adjuster, no additional significant amounts of oil are to be provided. The illustrated hydraulic circuits even out the Winkelverstellgeschwindigkeit the camshaft adjuster with the knowledge of the easy-to-implement check valve, the multiple in the hydraulic Soft is integrable. It has been designed a fault-tolerant, easy to build system that manages with less moving parts. Therefore, the invention can be applied to a valve and a suitable hydraulic circuit, in particular for camshaft adjuster of an internal combustion engine, in which a number of non-return valves or non-return valves functioning two-way valves are placed to provide a fast camshaft adjuster with high control performance.

LIST OF REFERENCE NUMBERS

reference numeral description 1 Motor vehicle hydraulic circuit 3 hydraulic pistons 5 hydraulic pump 7 Pan as a motor marsh 9 axial center 10 Point adjustment / valve 12 check valve 13 check valve 14 check valve 15 check valve 16 check line 18 check line 20 axial extension 22 Pressure reducing valve 24 Pressure reducing valve 26 Two-way valve 28 feed 30 supply line 32 biasing spring 33 Preloading spring, adjustable 34 Pressure supply line 36 Pressure supply line 38 supply throttle 40 supply throttle 42 leakage throttle 44 Pump Protection Valve 46 Pump protection valve, first 47 Pump protection valve, second 50 Opening position in cross connection 52 blocking position 54 Opening position in parallel connection 56 Pressure equalization valve 60 4/3-way valve 62 4/2-way valve 64 electrically controlled ram 66 hydraulically controlled ram 70 distribution line 72 distribution line 74 Control line, first 76 Control line, second 100 Phaser 102 camshaft 104 wing 106 locking opening 108 rotor 110 web 112 stator 114 rotor bearing 116 Damping hydraulic chamber 118 Dirt collection area 200 Valve 202 hydraulic pistons 204 band-shaped ring 206 band-shaped ring 208 band-shaped ring 210 shell 212 surface 214 cartridge valve 216 filter 218 magnetic valve 220 hydraulic part 224 outflow 226 cavity 250 hydraulic pressure 404 Pump Protection Valve FROM hydraulic chambers F / F + / F- external force P Input side / pressurized connection A1 / B1 Output side / work connection M + / M- torque fluctuations M + swelling moment T tank connection

Claims (6)

1. Valve (200) for a motor vehicle hydraulic circuit (1), in which moment fluctuations (M+, M-) in the form of either an alternating moment (M+, M-) or a pulsating moment (M+) occur, with a connection (P) to which pressure is applied, a tank connection (T), and at least two working connections (A1, B1), which can be connected alternately to the connection (P) to which pressure is applied by adjusting the hydraulic piston (202) of the valve (200),
   characterized in that
   the valve (200) passes on the hydraulic pressure (250), which can be diverted from the negative portion of the alternating moment (M-) on the one working connection (A1, B1) via at least one non-return valve (12, 14), to the second working connection (B1, A1), if otherwise the application of pressure to the connection (P) to which pressure is applied is passed on to the second working connection (B1, A1).
2. Valve (200) according to Claim 1, characterized in that
   the passing on of the negative portion of the alternating moment (M-) is implemented by means of non-return valves (12, 14), in particular two, the non-return valves (12, 14) preventing a hydraulic medium flow from the connection (P) to which pressure is applied to the appropriate working connection (A1, B1) if the pressure resulting from the absolute value of the negative portion of the alternating moment (M-) absolutely exceeds the pressure of the connection (P) to which pressure is applied.
3. Valve (200) according to one of the preceding claims,
   characterized in that
   the valve is a prestressed, in particular prestressed by a spring (32), cartridge valve (214), in particular a camshaft cartridge valve, the non-return valves (12, 14, 44, 46, 47) of which, in the form of band-shaped rings (204, 206, 208) below the surface (212) of the sleeve (210), form an integrated component.
4. Valve (200) according to one of the preceding claims,
   characterized in that
   the hydraulic piston (202), with two or three positions (50, 52, 54), is in the form of a directional valve, the first, unadjusted position of which is an open position in parallel connection (54), and a further, adjusted position is an open position in cross connection (50).
5. Valve (200) according to one of the preceding claims,
   characterized in that
   the first non-return valve (12) is arranged so that pressure peaks of the first working connection (A1) can be passed through, whereas the second non-return valve (14) is arranged so that pressure peaks of the second working connection (B1) can be passed through, and a third non-return valve (44, 46, 47) is in the form of a pump protection valve.
6. Valve (200) according to Claim 5, characterized in that
   as pump protection valves, two non-return valves (46, 47), which are oppositely blocking to the non-return valves (12, 14) of the non-return conduits (16, 18), are provided.

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