EP2375014B1 - Camshaft phaser comprising a hydraulic valve - Google Patents

Description

The invention relates to a Schwenkmotornockenwellenversteller with a hydraulic valve according to the preamble of claim 1.

The DE 10 2006 012 733 B4 and the DE 10 2006 012 775 B4 already relate to a Schwenkmotornockenwellenversteller with a hydraulic valve, which has two working ports. These two working ports each have axially adjacent to each other a standard opening and an opening for utilizing pressure peaks due to camshaft alternating torques. To adjust the camshaft, a hydraulic pressure can be conducted from a supply connection to the work connection to be loaded, while the work connection to be relieved is guided to a tank connection. The hydraulic valve is designed as a 4/3-way valve in cartridge design. In the sleeve check valves are used on the inside, which are designed as band-shaped rings. By means of these check valves camshaft alternating torques are used to adjust the camshaft adjuster particularly fast or with a relatively low oil pressure can. The check valves cover the openings for the use of pressure peaks due to camshaft alternating torques.

The object of the invention is to provide a simple to be controlled with little effort Schwenkmotornockenwellenversteller.

This object is achieved with the features of claim 1.

According to one advantage of the invention, the camshaft alternating torques for fast phasing of the camshaft can be used in the invention Schwenkmotornockenwellenversteller. Moreover, due to the use of camshaft alternating torques, it is advantageously possible to enable adjustment with a relatively low oil pressure. A thus possible small dimensions of the oil pump improves the efficiency of the internal combustion engine. The saved volume flow of hydraulic fluid is different Consumers, such as a hydraulic valve lift adjustment available.

Pivot camshaft phasors have also recently been applied to the combustion engines with fewer cylinders to reduce fuel consumption, increase performance, and reduce exhaust emissions. The smaller the number of cylinders, the greater the fluctuations of the Nockwellenwechselmomente. With the use of the highly fluctuating camshaft alternating torques for phase adjustment, however, there is a high need for coordination of the control of the hydraulic valve. According to a further advantage of the invention, the hydraulic valve is proportional to a first switching position adjustable in which the effect of check valves for the use of camshaft alternating torques is bypassed. Due to the proportional controllability of the control process between use of the camshaft alternating torques and circumvention of this use is continuously controlled. Thus, the hydraulic valve is additionally adjustable in favor of a higher control quality in a switching position to bypass the use of camshaft alternating torque.

In the dependent claims a structurally particularly simple implementation of such a hydraulic valve is claimed. Opposite in the DE 10 2006 012 733 B4 and the DE 10 2006 012 775 B4 shown hydraulic valve results in a relatively small additional cost for two additional ribs on the piston, which is negligible, for example, in a plastic piston or other injection-molded piston. The distance between the ribs relative to the corresponding annular webs or inner ring grooves within the bushing must be precisely defined, since the overlapping of these ribs with the annular webs of the bushing determines the flow cross sections.

In a particularly advantageous manner, it is thus possible to produce such a hydraulic valve according to the invention with many identical parts, which originate from hydraulic valves without bypassing the use of the camshaft alternating moment or even entirely without the use of a camshaft alternating moment. There is also a high common parts potential with hydraulic valves with center locking. Such a common part strategy with change of the piston is, for example, in the unpublished DE 10 2009 022 869.1-13 shown.

Further advantages of the invention will become apparent from the other claims, the description and the drawings.

The invention is explained in more detail with reference to an embodiment.

• Fig. 1 in einem Schaltzeichen ein proportional ansteuerbares und in fünf hauptsächliche Schaltstellungen betätigbares Hydraulikventil,
• Fig. 2 eine konstruktive Umsetzung des Hydraulikventils gemäß Fig. 1 in einer Schaltstellung,
• Fig. 3 das Hydraulikventil gemäß Fig. 2 in einer anderen Schaltstellung,
• Fig. 4 das Hydraulikventil gemäß Fig. 2 in einer anderen Schaltstellung,
• Fig. 5 das Hydraulikventil gemäß Fig. 2 in einer anderen Schaltstellung und
• Fig. 6 das Hydraulikventil gemäß Fig. 2 in einer anderen Schaltstellung,

In the drawing show:

• Fig. 1 in a circuit diagram a proportionally controllable and operable in five major switch positions hydraulic valve,
• Fig. 2 a constructive implementation of the hydraulic valve according to Fig. 1 in a switching position,
• Fig. 3 the hydraulic valve according to Fig. 2 in another switch position,
• Fig. 4 the hydraulic valve according to Fig. 2 in another switch position,
• Fig. 5 the hydraulic valve according to Fig. 2 in another switch position and
• Fig. 6 the hydraulic valve according to Fig. 2 in another switch position,

Fig. 1 shows in a circuit diagram a by means of an electromagnet 17 against a spring force of a spring 21 operable hydraulic valve 3, which is controlled proportionally. With this hydraulic valve 3 a Schwenkmotornockenwellenversteller 4 is pivotable. With such a Schwenkmotornockenwellenversteller 4, the angular position between the crankshaft and the camshaft is changed during operation of an internal combustion engine. By turning the camshaft, the opening and closing times of the gas exchange valves are shifted so that the internal combustion engine brings its optimal performance at the respective speed. The Schwenkmotornockenwellenversteller 4 allows a continuous adjustment of the camshaft relative to the crankshaft.

From the hydraulic valve 3, a first consumer port A and a second consumer port B go to the Schwenkmotornockenwellenversteller 4 from. The hydraulic valve 3 has four ports and five shift positions and can thus also be referred to as a 4/5-way valve with a locking middle position 7. In order to pivot the Schwenkmotornockenwellenversteller 4 now in the first direction of rotation 1, the hydraulic valve 3 is in one of the two switching positions 16, 19, which are represented by the two switch box behind the locking center position 7. In the drawing Fig. 1 the hydraulic valve is in the switch position 19 of the switch box at the very rear. In this case, pressure chambers 6 associated with this direction of rotation 1 are acted upon by the first consumer port A by a pressure which comes from a supply port P. On the other hand, the pressure chambers 5 assigned to the second - ie opposite - direction of rotation 2 are relieved to the second consumer connection B. The second consumer port B is guided to a tank 20 via a tank connection T.

Conversely, analogous applies. That To pivot the Schwenkmotornockenwellenversteller 4 in the second direction of rotation 2, the hydraulic valve 3 is in one of the two switching positions 18, 15, which are represented by the two switch box before the locking center position 7. In these switching positions 18, 15, the pressure chambers 5 associated with this direction of rotation 2 are acted upon by the second consumer port B with a pressure which comes from the supply port P. On the other hand, those of the first - i. opposite to the direction of rotation 1 associated pressure chambers 6 to the first load port A out relieved. The first consumer port A is guided to the tank 20 via the tank port T.

In the said locking middle position 7 all four ports A, B, P, T are blocked. In the two of these locking middle position 7 adjacent switching positions 15, 16, the adjustment of the camshaft without using the camshaft alternating moments.

For this purpose, in the switching position 15 of the supply port P is guided to the second load port B, whereas the first supply port A on the tank connection T is guided. A bypass via a check valve is not provided in this switching position 15.

In the switching position 16 of the supply port P is guided to the first consumer port A, whereas the second supply port B is guided to the tank port T. A bypass via a check valve is not provided in this switching position 15.

In the two outermost switching positions 18, 19 of the hydraulic valve 3, the adjustment of the camshaft takes place with use of the camshaft alternating torques. For this purpose, an outermost switching position 18 similar to the immediately adjacent switching position 15 is executed. In addition, however, a volume flow from the hydraulic fluid coming from a check valve RSV-A assigned to the first supply connection A is made available to the supply connection P. By contrast, the other outermost switching position 19 is similar to the immediately adjacent switching position 16 executed. In addition, however, a volume flow of hydraulic fluid coming from a check valve RSV-B assigned to the second supply connection B is made available to the supply connection P.

This additional volume flow from the load connection A or B to be relieved is fed into the volume flow coming from an oil pump 12 at the supply connection P. The supply port P leads via a pump check valve RSV-P to the oil pump 12, which applies the pressure for adjusting the Schwenkmotornockenwellenverstellers 4. This pump check valve RSV-P blocks the pressures in the hydraulic valve 3 so that peak pressures coming from the load connection A or B to be relieved can be made available to a larger proportion of the adjustment assistance than is the case with an open oil pump line 14a, 14b would.

Fig. 2 to Fig. 6 show a constructive embodiment of the hydraulic valve 3 in the five switching positions 18, 15, 7, 16, 19 according to Fig. 1 ,

Fig. 2 shows the hydraulic valve 3 in the first switching position 18, in which the electromagnet 17 according to Fig. 1 a hollow piston 22 of the hydraulic valve 3 does not move. The stroke of the piston 22 is thus at zero. The piston 22 is displaceable within a bushing 27 against the force of the spring designed as a helical compression spring 21. The electromagnet 17 facing the front end is closed to produce a contact surface for an actuating plunger of the electromagnet 17, whereas the other end face for the realization of the tank port T is open. The piston 22 has at its two ends outer webs 23, 24, which are guided relative to the bushing 27. The two outer webs 23, 24 are pierced by transverse bores 29, 30, so that from these transverse bores 29, 30 via the interior of the hollow piston 22 access to the tank port T is present.

Axially between the two outer webs 23, 24, two narrow ribs 31, 32 are provided, which rotate around the piston 22. These circumferential ribs 31, 32 correspond to two annular webs 33, 34 extending radially inwardly from the bush 27. In addition to these two annular webs 33, 34, two axially outer annular webs 35, 36 are provided. These four ring lands 33 to 26 are formed, since five inner ring grooves 37 to 41 are turned out of the socket. In this five Innenringnuten 37 to 41 five connection holes, which are drilled through the wall of the socket 27 open.

• eine dem zweiten Arbeitsanschluss B zugehörige Standardöffnung B1,
• eine dem zweiten Arbeitsanschluss B zugehörige Öffnung B2 zur Nutzung von Nockenwellenwechselmomenten,
• den Versorgungsanschluss P,
• eine dem ersten Arbeitsanschluss A zugehörige Standardöffnung A1 und
• eine dem ersten Arbeitsanschluss A zugehörige Öffnung A2 zur Nutzung von Nockenwellenwechselmomenten.

These five connection bores form axially successive sides of the electromagnet 17:

• a standard opening B1 associated with the second working connection B,
• a second working port B associated opening B2 for the use of camshaft alternating torques,
• the supply terminal P,
• a standard opening A1 and associated with the first working port A.
• a first working port A associated opening A2 for the use of camshaft alternating torques.

At the two working ports A, B thus two openings A1, A2 and B1, B2 are provided. Of these, the axially inner openings A2, B2 for provided a camshaft alternating torque use. In contrast to the axially outer openings A1, B1, which can be locked from the inside only with the outer webs 23, 24, the axially inner openings A2, B2 have the band-shaped check valves RSV-A, RSB-B. In each case one of the band-shaped check valves RSV-A and RSB-B is inserted into an inner annular groove 25 and 26 radially inside the axially inner openings A2 and B2 of the bush 27. With the check valves RSV-A, RSV-B it is according to the in the DE 10 2006 012 733 B4 described method possible to provide a hydraulic pressure in the pressure chambers to be relieved 5 and 6 due to camshaft alternating torques briefly above the level of hydraulic pressure in the hydraulic chambers to be loaded 6 and 5, in the region of the supply port P. From this supply connection P, this hydraulic pressure peak or this additional hydraulic fluid volume flow together with the hydraulic pressure applied by the oil pump 12 to the supply port P is then made available to the hydraulic chambers 6 and 5 to be loaded.

In addition, the band-shaped pump check valve RSV-P is still provided in an inner annular groove 28. This pump check valve RSV-P has basically the same structure as the two check valves RSV-A, RSV-B. However, this pump check valve RSV-P may have a different response force.

In the switch position 18 according to Fig. 2 the two middle ribs 31, 32 are axially spaced from the two annular ribs 33, 34, so that hydraulic fluid can pass through the gaps therebetween. Likewise, hydraulic fluid can pass through the gap between the foremost outer web 23 and the corresponding annular web 35 on the bushing 27. On the other hand, the other outer web 24 blocks the rearmost inner annular groove 41 or the standard opening A1 associated with the first working port A. For this purpose, the outer web 24 and the rearmost annular web 36 overlap over a large sealing length. Thus, in this switching position 18, hydraulic fluid can pass from the supply port P via the pump check valve RSV-P to the standard port B1 associated with the second working port B. The other two check valves RSV-A and RSV-B block the openings A2 and B2 against pressures from the supply port P and from the the second working port B associated standard opening B1. By contrast, short-term peak pressures due to the camshaft alternating torques from the first working port A associated opening A2 through its check valve RSV-A.

The first working port A is guided or relieved via its standard opening A1 and the transverse bore 30 to the tank port T.

Fig. 3 shows the piston 22 at a stroke of a = 0.4 mm. In this case, the hydraulic valve 3 is in the switching position 15. Compared to the switching position 18, the rear rib 32 covers the corresponding annular land 34 so far that a flow through the very narrow gap is possible only with increased flow resistance. In addition, since the very slightly biased check valve RSV-A has a flow resistance, it is the short-term peak pressures due to camshaft alternating torques not possible to get from the first working port A to the second working port B.

The first working port A is guided or relieved via its standard opening A1 and the transverse bore 30 to the tank port T.

Fig. 4 shows the piston 22 at a stroke of b = 1.55 mm. In this case, the hydraulic valve 3 is in the locking center position 7. The supply port P is closed by the two ribs 31, 32. For this purpose, the ribs 31, 31 cover the corresponding annular webs 33, 34 in a correspondingly large extent. The two working connections A, B are blocked against the tank drain T. For this purpose, in the blocking middle position 7, both transverse bores 29, 30 are located axially outside the axially outer inner annular grooves 37, 41.

Fig. 5 shows the piston 22 at a stroke of c = 2.7 mm. Here, the hydraulic valve 3 is in the switching position 16. In this case, coming from the supply port P hydraulic fluid through the gap between the rear rib 32 and the corresponding ring land 34 to the standard opening A1 of the first working port A pass. In contrast, the front rib 31 covers the corresponding annular web 33 so far that a flow through the very narrow Gap is only possible with increased flow resistance. In addition, since the very slightly biased check valve RSV-B has a flow resistance, it is the short-term peak pressures due to camshaft alternating torques not possible to get from the second working port B to the first working port A.

The second working port B is guided or relieved via its standard opening B1 and the transverse bore 29 to the tank port T.

Fig. 6 shows the piston 22 at a stroke of d = 3.1 mm. In this switching position 19, the two middle ribs 31, 32 axially spaced from the two annular ridges 33, 34, so that hydraulic fluid can pass through the gaps between them. Likewise, hydraulic fluid can pass through the gap between the rearmost outer web 24 and the corresponding annular web 36. On the other hand, the other outer web 23 blocks the foremost inner annular groove 37 and the standard opening B1 of the second working port B for this purpose. The outer web 23 and the foremost annular web 35 overlap over a large sealing length. In this way, in this switching position 19 hydraulic fluid can reach from the supply connection P via the pump check valve RSV-P to the standard opening A1 of the first working connection A. In contrast, the other two check valves RSV-A and RSV-B block the openings A2 and B2 against pressures from the supply port P and from the standard opening B1 of the second working port B. On the other hand, short-term peak pressures due to the camshaft alternating torques from the opening B2 of the second working port B by the Check valve RSV-B let through.

The second working port B is guided or relieved via its standard opening B1 and the transverse bore 29 to the tank port T.

In the illustrated embodiment, the standard opening A1 or B1 and the opening A2 or B2 are summarized for use of camshaft alternating moments only outside the bushing 27 to the working port A and B respectively. In alternative embodiments, it is also possible to use the standard opening A1 or B1 and the opening A2 or B2 for the use of camshaft alternating torques already merge within the socket 27. For this purpose, for example, an annular groove can be incorporated radially outside into the socket.

In a further alternative embodiment, ball check valves may be used instead of band check valves. For example, it is also possible to use within the hydraulic valve ball check valves, as this example, the DE 10 2007 012 967 B4 shows. However, the ball check valves need not necessarily be installed in the socket of a cartridge valve. It is also possible, for example, to use the ball check valves in a rotor and run the piston as a central valve which is arranged coaxially and centrally within the rotor hub slidably.

Depending on the conditions of use of the valve, screens may also be provided in the direction of flow in front of one or more or even all ports, which protect the running surfaces between the piston and the bushing.

The hydraulic valve can also find application in a so-called central valve. The socket is not directly connected to the magnetic part. Instead, the hydraulic valve is centrally located in the rotor of the Schwenkmotornockenwellenverstellers so that the sleeve rotates together with the piston. The magnet, however, is rotationally fixed relative to the cylinder head arranged, so that a relative movement between the plunger of the magnetic member and the piston takes place.

The use of camshaft alternating torques does not have to be provided for both directions of rotation. It is also possible to dispense with one of the two axially outermost switching position 18 or 19. As a result, the camshaft alternating torques can then be used directly for faster adjustment only for the one direction of rotation.

In an alternative embodiment, a use of the camshaft alternating torques can be provided for both directions, but then to one of the two check valves RSV-A, RSV-B bypassing switch positions 15, 16 is omitted.

• 18, 15, 16 oder
• 15, 16, 19 oder
• 18, 15, 19 oder
• 18, 16, 19

vorzusehen.Any combinations of switch positions are possible. So it is possible, except the middle position 7 nor the switch positions

• 18, 15, 16 or
• 15, 16, 19 or
• 18, 15, 19 or
• 18, 16, 19

provided.

At the hydraulic valve can also be provided a further switching position in which both working ports A, B are relieved against the tank port T, so that a so-called center locking is made possible. In such a central locking a locking bolt is provided in the Schwenkmotornockenwellenversteller, which fixes the rotor in an angular position against the stator, which is not an end position. Such a central locking is for example in the DE 10 2004 039 800 B4 and the not pre-published DE 10 2009 022 869.1-13 shown.

The described embodiments are only exemplary embodiments. A combination of the described features for different embodiments is also possible. Further, in particular not described features of the device parts belonging to the invention are to be taken from the geometries of the device parts shown in the drawings.

LIST OF REFERENCE NUMBERS

1

direction of rotation

2

direction of rotation

3

hydraulic valve

4

Oscillating motor camshaft adjuster

5

pressure chamber

6

pressure chamber

7

Blocking center position

8th

Alternating torque return connection

9

Alternating torque return connection

10

Tank return

11

Return line

12

oil pump

13

Return line

14

a, b oil pump line

15

switch position

16

switch position

17

electromagnet

18

switch position

19

switch position

20

tank

21

feather

22

piston

23

outer web

24

outer web

25

inner annular

26

inner annular

27

Rifle

28

inner annular

29

cross holes

30

cross holes

31

rib

32

rib

33

ring land

34

ring land

35

ring land

36

ring land

37

inner annular

38

inner annular

39

inner annular

40

inner annular

41

inner annular

A

first work connection

A1

first standard opening

A2

first opening for the use of camshaft alternating torques

B

second work connection

B1

second standard opening

B2

second opening for the use of camshaft alternating torques

P

supply terminal

T

tank connection

Claims (6)

1. Oscillating-motor camshaft adjuster (4) having a hydraulic valve (3), the hydraulic valve having two working ports (A, B), which each have a standard opening (A1 and B1, respectively) axially adjacent to one another and an opening (A2 and B2, respectively) for utilising pressure peaks as a result of camshaft alternating torques, a hydraulic pressure being guidable from a supply port (P) to the working port (A and B, respectively) to be loaded, while the working port (B and A, respectively) to be relieved is led to a tank port (T), characterised in that a switching position (16 and 15, respectively) of the hydraulic valve (3) is proportionally controllable, in which position the pressure peaks of the working port (B and A, respectively) to be relieved are blocked relative to the working port (A and B, respectively) to be loaded.
2. Oscillating-motor camshaft adjuster having a hydraulic valve according to Claim 1, characterised in that, proceeding from a blocking centre position (7) of the hydraulic valve (3), initially the first switching position (16 and 15, respectively) and thereater a further switching position (19 and 18, respectively) is controllable in order to utilise the camshaft alternating torques.
3. Oscillating-motor camshaft adjuster having a hydraulic valve according to Claim 2, characterised in that the hydraulic valve (3) has a piston (22), which is guided inside a bush (27), and two outer webs (23, 24) for blocking the two standard openings (A1, B1), two ribs (31, 32) being provided axially between these outer webs (23, 24), with which ribs, on the one hand, the supply port (P) can be blocked in the blocking centre position (7) against the two working ports (A, B) and, on the other hand, the opening (B2 and A2, respectively) for utilising pressure peaks as a result of camshaft alternating torques can be blocked in the first switching position (16 and 15, respectively) against the supply port (P), from which the hydraulic pressure is guided to the standard opening (A1 and B1, respectively) past the other opening (A2 and B2, respectively) blocked by a non-return valve (RSV-A and RSV-B, respectively).
4. Oscillating-motor camshaft adjuster having a hydraulic valve according to Claim 3, characterised in that the standard opening (B1) of the working port (B) to be relieved is blocked in the first switching position (16 and 15, respectively) by means of the one web (23 and 24, respectively) against the opening (B2) of the same working port (B).
5. Oscillating-motor camshaft adjuster having a hydrualic valve according to Claim 4, characterised in that the outer web (23 and 24, respectively) has a cross bore (29 and 30, respectively), which guides hydraulic fluid to the tank port (T) from the standard opening (B1) of the working port (B) to be relieved in the first switching position (16 and 15, respectively) via the piston (22) which is of hollow design.
6. Oscillating-motor camshaft adjuster having a hydraulic valve according to one of the preceding claims, characterised in that, in said proportionally controllable switching position (16 and 15, respectively), the pressure peaks of the working port (B and A, respectively) to be relieved are blocked relative to the working port (A and B, respectively) to be loaded and the supply port (P).

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