DE102010032133B4 - Central valve - Google Patents

Abstract

Hydraulic valve (12) for a swivel motor adjuster, in which a hollow piston (23) is guided within a bushing (22) which forms a main body of the hydraulic valve (12) and axially one after the other a radial oil supply connection (P), a first radial working connection (B ) and a second radial working connection (A), these working connections (B, A) assigned to these two opposite directions of rotation of the swivel motor adjuster being followed by a tank drain (T) which is arranged exclusively at one end of the hydraulic valve (12), the socket (22) circumferentially offset to the second working connection (A) has a tank drain channel (38) leading to the tank drain (T), - which drains the fluid from the first working connection (B) past the second working connection (A) when the latter from the oil supply connection ( P) is supplied with fluid and - which removes the fluid directly from the second working connection (A) when the first working connection (B ) is supplied with fluid from the oil supply connection (P), the tank drain channel (38) being delimited by a closed wall (59) of the bushing (22).

Description

According to claim 1, the invention relates to a central valve for a swivel motor adjuster.

From the DE 10 2005 041 393 A1 a central valve for a swivel motor adjuster is already known which, in accordance with the invention, has a piston which is guided within a bushing. A radial oil supply connection is in axial succession P provided a first radial working connection B and a second radial working port A follows. This second radial working connection A follows a tank drain T which is the only tank drain T forms. The piston is not rotationally symmetrical and has two separate channels that run past one another. In order to move the piston axially, a push rod of an actuator rests against it.

Also the DE 10 2005 052 481 A1 shows a central valve for a swivel motor adjuster. The two working connections also follow on this central valve A , B the oil supply connection P , which in turn is a single tank drain T follows. To distribute the oil from the oil supply connection P on the respective work connection A or. B there is provided a hollow piston which can be displaced by means of an actuator and which is supported on a helical compression spring.

Furthermore, from the DE 103 22 394 A1 a swivel motor adjuster is known, within which a hydraulic valve is provided.

The object of the invention is to provide a hydraulic valve - in particular a central valve - which can be connected in a cost-effective manner PBAT enables.

This object is achieved with the features of claim 1.

The hydraulic valve according to the invention is used in particular as a central valve radially within a camshaft or within a rotor. However, it is also possible to arrange the hydraulic valve outside the rotor.

According to an advantage of the invention, a hollow piston is used according to the invention which has a central recess. This hollow piston is displaceable in a bushing which is circumferentially offset from a first working connection A at least one to the tank drain T leading tank drainage channel. As a result of this circumferential offset, it is possible to connect the fluid to the second working connection A over to the tank drain T dissipate. The fluid can be discharged axially or radially from the hydraulic valve. The circumferentially offset tank drainage channel is formed in the socket. For this purpose, the tank drain channel is formed by a passage which is enclosed by a wall of the socket. In order to make optimal use of the existing cross sections, thin-walled and complex geometries are necessary, which is why the metal injection molding process can be used in particular. However, this complex geometry can alternatively or additionally be created with bores and / or millings. In this case of machining, the bushing can also be manufactured as a turned part.

In a particularly advantageous embodiment, the hydraulic valve according to the invention can have pressure fluctuations in the second working connection B use assigned pressure chambers of the swivel motor adjuster to supply the pressure chambers assigned to the opposite direction of rotation with sufficient fluidic volume flow. These pressure fluctuations result from the camshaft alternating torques that occur on the camshaft in response to the gas exchange valve forces. The lower the number of combustion chambers per camshaft, the stronger the camshaft alternating torques, so that the use of the camshaft alternating torques is particularly suitable for internal combustion engines with three cylinders. In addition, influencing parameters are the strength of the gas exchange valve springs and the camshaft speed.

The number of tank drain channels and their cross-section determine the flow resistance at the tank drain T .

Further advantages of the invention emerge from the further patent claims, the description and the drawing.

The invention is explained in more detail below using several exemplary embodiments.

• 1 einen Schwenkmotorversteller in einer geschnittenen Ansicht,
• 2 die Buchse eines Zentralventils, welches in einen Schwenkmotorversteller gemäß 1 eingesetzt ist,
• 3 in einem Längsschnitt das Zentralventil aus 2, wobei dessen Hohlkolben von einem elektromagnetischen Stellglied unbelastet ist,
• 4 das Zentralventil in einem Querschnitt entlang Linie IV-IV aus 2,
• 5 das Zentralventil in einem Querschnitt entlang Linie V-V aus 2
• 6 das Zentralventil in Mittenstellung und
• 7 das Zentralventil in Endlage.

Show

• 1 a swivel motor adjuster in a sectional view,
• 2nd the socket of a central valve, which according to a swivel motor adjuster 1 is used
• 3rd the central valve in a longitudinal section 2nd , the hollow piston of which is not loaded by an electromagnetic actuator,
• 4th the central valve in a cross section along line IV-IV out 2nd ,
• 5 the central valve in a cross section along line VV out 2nd
• 6 the central valve in the middle position and
• 7 the central valve in the end position.

With a swivel motor adjuster according to 1 the angular position of 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 in such a way that the internal combustion engine performs optimally at the respective speed. The swivel motor adjuster enables stepless adjustment of the camshaft relative to the crankshaft. The swivel motor adjuster has a cylindrical stator 1 on the rotatable with a drive wheel 2nd connected is. In the exemplary embodiment, the drive wheel 2nd a sprocket over which a chain, not shown, is guided. The drive wheel 2nd can also be a toothed belt wheel over which a drive belt is guided as a drive element. About this drive element and the drive wheel 2nd is the stator 1 drive connected to the crankshaft.

The stator 1 comprises a cylindrical stator body 3rd , on the inside of which radially inwards webs at equal intervals 4th stand out. Between neighboring bridges 4th become spaces 5 formed, into, about, in 2nd to 8th Central valve shown in more detail 12 controlled, pressure medium is introduced. Between neighboring bridges 4th protrude wings 6 that are radially outward from a cylindrical rotor hub 7 of a rotor 8th stand out. These wings 6 divide the gaps 5 between the bridges 4th each in two pressure chambers 9 and 10th .

The bridges 4th are sealed with their end faces on the outer surface of the rotor hub 7 on. The wings 6 in turn lie with their end faces sealingly against the cylindrical inner wall of the stator main body 3rd on.

The rotor 8th is rotatably connected to the camshaft, not shown. By the angular position of the camshaft in relation to the drive wheel 2nd to change is the rotor 8th relative to the stator 1 turned. Depending on the desired direction of rotation, the pressure medium in the pressure chambers is used for this purpose 9 or 10th pressurized while the other pressure chambers 10th or 9 relieved to the tank. Around the rotor 8th towards the stator 1 to pivot counterclockwise into the position shown are from the central valve 12 radial bores 11 in the rotor hub 7 put under pressure.

A socket 22 this central valve 12 is in 2nd visible as a single part. This is the central valve 12 in the assembled state, not shown in the drawing, into the rotor hub 7 screwed. In further alternative configurations, not shown in the drawing, it is also possible for the central valve 12 Insert and / or screw into the camshaft or a separate camshaft end piece. The radial holes 11 the rotor hub 7 lead into an annular groove 15 of the central valve 12 who have a first job connection A forms. In this ring groove 15 leads a group of radial recesses 14 of the central valve 12 . This group of radial recesses 14 is on the circumference of the central valve 12 distributed. Because the the main body of the central valve 12 forming socket 22 In metal injection molding, these recesses must be made 14 as well as axially adjacent recesses 17th , 18th , 21st not be bored. It is possible to make these recesses 14 , 17th , 18th , 21st to be carried out according to the drawing with a square shape. This enables better use of the cross-sections.

Regarding a central axis 13 axially next to this first working connection A is a second work connection B provided by an annular groove 16 is formed. This second work port B leads into the radial holes 58 the rotor hub 7 which in the pressure chambers 9 to lead. These pressure chambers 9 are swiveling the rotor 8th assigned clockwise. The two work connections A , B assigned and immediately adjacent groups of radial recesses 14 , 17th are basically equivalent connections. The first work connection B assigned recesses 17th set themselves apart from the special group B1 from. This special group B1 is an in 3rd apparent check valve 43 assigned which is within the socket 22 behind recesses 18th lies. The special group B1 of the recesses 18th in the first work connection B serves the use of camshaft alternating torques for swiveling the rotor quickly 8th or a pivoting of the rotor 8th despite low oil pressure at an oil supply connection P .

The oil supply connection P joins the special group B1 with respect to the central axis 13 axially on. This is the second work connection B and the special group B1 axially between the first working connection A and the oil supply connection P . In an annular groove 19th the oil supply connection P is an annular sieve 44 used which this oil supply connection P before dirt particles enter the central valve 12 protects. The ring-shaped sieve 44 is shaped in the manner of an annular band. Instead of a closed one Ring, the sieve can also be formed as an open band that overlaps at the ends. In this case, the tape is spread out for assembly and then onto the socket 22 postponed. In an annular groove 45 the oil supply connection P is a band-shaped pump check valve 39 used. However, a check valve arranged outside the central valve, for example a ball check valve, can also be provided.

In 3rd it can be seen that also in the ring groove 19th the oil supply connection P Holes 21st are provided on the circumference of the central valve 12 the socket 22 are arranged.

Within this socket 22 is a hollow piston 23 axially displaceable. 3rd shows the relieved central valve 12 . The central valve 12 is considered to be relieved when one on the P-side end of the hollow piston 23 adjacent end of a push rod 24th is not loaded by an electromagnet or electromagnetic actuator. In this state, the electromagnet is de-energized. The push rod 24th is at the central valve 12 facing end 26 executed with a curve so that the contact surface is idealized - that is, by hiding the Herz's pressure - point-shaped.

In this in 3rd Relieved state of the central valve shown 12 becomes the hollow piston 23 from a helical compression spring 29 against an axial stop 34 pressed. This axial stop 34 is formed by an axial locking ring, which at the P-side end in an inner ring groove of the socket 22 is used. The helical compression spring 29 on the other hand is at the opposite end - ie at a T-side end - of the socket 22 arranged. This helical compression spring is supported 29 on the one hand at the socket 22 from. On the other hand, the helical compression spring is supported 29 indirectly via a closure body 36 on the hollow piston 23 from. This is the closure body 36 at the T-side end within a first ring web 1 on the hollow piston 23 inserted so that this end is closed. At this first ring bridge 30th is a first paragraph 32 provided that this first ring land 30th from an annular groove 40 delimits.

In the state shown, hydraulic fluid from the first working connection A to the tank drain T dissipated. For this, the hydraulic fluid from the first working connection A through its recesses 14 and the ring groove 40 in the hollow piston 23 to an inner ring groove 28 in the socket 22 headed. This inner ring groove 28 leads into passages 35 which tank drainage channels 38 are associated.

In the ring groove 40 make recesses 27th into an interior of the hollow piston 23 . These recesses 27th are formed semicircular on the side axially facing the P-side end, so that the tank drain T not suddenly, but to an increasing extent, can be closed and opened.

This is the ring groove 40 axially on one side of said paragraph 32 and on the opposite side from the rounded paragraph 33 limited. This rounded paragraph 33 is therefore on a second ring land 31 arranged. If the electromagnet according to 7 is fully energized, so the push rod 24th the hollow piston 23 this rounded paragraph closes as far as possible 33 the inner ring groove 28 to the tank drain T .

In the in 7 shown maximum disengaged position of the hollow piston 23 becomes the first work connection A with hydraulic fluid from the supply connection P supplied, whereas the second work connection B against the tank connection T is relieved.

6 shows the central valve 12 with the hollow piston 23 in a central position, which is reached when the electromagnet is disengaged halfway. This turns on the central valve 12 an overlap control in which a higher volume flow can be supplied to the pressure chambers assigned to the two directions of rotation than can be discharged to the tank.

The socket 22 has the external thread at its P-side end 20th on, which is followed by a collar that leads to the tool attack 41 is formed. For example, as a tool attack 41 a hexagon be formed. This makes it possible to use the central valve 12 to screw into the swivel motor adjuster or into the camshaft or a camshaft end piece. In an alternative embodiment, the external thread can also be provided at the other end in order to brace the rotor against the camshaft. The external thread 20th can already in the manufacture of the socket 22 in metal injection molding into this socket 22 be molded. It is not necessary to cut the thread.

On the tool attack 41 opposite end are in the bottom of the ring groove 15 the recesses 14 intended. This ring groove 15 is axially delimited on both sides by ring bars. The socket is at the T-side end 22 cone-shaped. On a floor 42 this pin-shaped end is the helical compression spring 29 axially supported.

Circumferentially between the recesses 14 are at the peg-shaped end which are parallel to the central axis 13 extending passages 35 intended. This is particularly evident in 4th evident. So it shows 4th the hydraulic valve 12 in a cross section along an in 2nd apparent line IV-IV . This line IV-IV runs perpendicular to the central axis 13 through the recesses 14 . It can be seen that these passages 35 or tank drainage channels 38 circumferentially even between the recesses 14 are arranged. The passages 35 the tank drainage channels 38 are of walls 59 enclosed. Through these walls 59 the four recesses run 14 without the passages 35 to cross. Of the four recesses 14 two are aligned with each other, the recesses 14 are arranged orthogonally to each other.

5 shows the hydraulic valve 12 in a cross section along an in 2nd apparent line VV which are perpendicular to the central axis 13 through the recesses 21st runs. This the supply connection P assigned recesses 21st are not evenly spaced. The arrangement of the recesses is, however, selected so that a tool geometry is made possible for the production in metal injection molding, which enables the bushing to be released easily 22 allowed out of the tool. In the same way, the recesses 18th the special group B1 manufactured.

The tool points to the production of the recesses 14 , 18th , 21st in the socket 22 so-called slide.

• - für die Einlassventile oder
• - für die Auslassventile

aufgesetzt ist. Außerdem wird die bevorzugte Drehrichtung des Schwenkmotorverstellers durch die Vorspannung einer nicht näher dargestellten Spiralfeder bestimmt, welche den Rotor gegenüber dem Stator vorspannt und das Reibmoment der Nockenwelle gegenüber dem Gaswechselventiltrieb kompensiert. Dabei kann die Spiralfeder so stark ausgelegt sein, dass sie das Reibmoment überkompensiert oder auch so schwach ausgelegt sein, dass sie das Reibmoment nicht gänzlich kompensieren kann. Eine solche Spiralfeder ist beispielsweise in der nicht vorveröffentlichten DE 10 2009 048 238 A1 dargestellt. Auch von deren Auslegung hängt es ab, ob der Anschluss für die Nockenwellenwechselmomentennutzung eher zu den der Drehrichtung in Früh oder der Drehrichtung in Spät zugeordneten Druckkammern führt.The pressure chambers at the first working connection assigned to the use of camshaft alternating torques B1 can be assigned to the early adjustment or the late adjustment. Depending on whether the swivel motor adjuster on the camshaft

• - for the intake valves or
• - for the exhaust valves

is put on. In addition, the preferred direction of rotation of the swivel motor adjuster is determined by the pretension of a spiral spring, not shown, which prestresses the rotor relative to the stator and compensates the frictional torque of the camshaft relative to the gas exchange valve train. The spiral spring can be designed so strongly that it overcompensates for the frictional torque or it can also be designed so weakly that it cannot fully compensate for the frictional torque. Such a coil spring is, for example, in the unpublished DE 10 2009 048 238 A1 shown. It also depends on their design whether the connection for the use of the camshaft alternating torque leads more to the pressure chambers assigned to the direction of rotation in early or the direction of rotation in late.

It is also possible to assign the use of camshaft alternating torques to both directions of rotation by using two working connections A , B additional recesses for the use of camshaft alternating torques can be assigned.

The socket according to 2nd does not have to be in a swivel motor adjuster 1 be used, but can also be used in the camshaft. Accordingly, the central valve can in particular be screwed into the camshaft itself or into a camshaft end piece. However, it is also possible to screw the central valve into the rotor. Instead of the screw shape shown, the central valve can also be designed with a threaded pin onto which a nut is screwed. The external thread does not have to be provided on the P-side end. Another axial position is also possible. Such a different axial position is particularly useful when the rotor is to be braced against the camshaft with the central valve.

The slots in the socket do not have to be aligned parallel to the central axis.

The hollow piston does not have to be designed with ring webs. It is also possible to design the hollow piston with only radial recesses. In that case, the shoulders are formed by the edges of the recesses.

Both the bushing and the hollow piston can be manufactured with the respective recesses in metal injection molding, as an injection molded part or as a turned part. The recesses can also be drilled.

In an alternative embodiment, use of camshaft alternating torques is provided for both working connections.

In a further alternative embodiment, the check valve feed bores for using the camshaft alternating torques are axial between the two working connections A , B arranged.

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

Reference symbol list

1

stator

2nd

drive wheel

3rd

Stator body

4th

Walkways

5

Gaps

6

wing

7

Rotor hub

8th

rotor

9

Pressure chamber

10th

Pressure chamber

11

radial bores

12

Central valve, hydraulic valve

13

Central axis

14

Recesses

15

Ring groove

16

Ring groove

17th

Recesses

18th

Recesses

19th

Ring groove

20th

External thread

21st

Recesses

22

Rifle

23

Hollow piston

24th

Push rod

25th

..

26

The End

27th

Recesses

28

Inner ring groove

29

Helical compression spring

30th

Ring bridge

31

Ring bridge

32

paragraph

33

paragraph

34

Axial stop

35

Passages

36

Closure body

37

Ring bridge

38

Tank drainage channels

39

check valve

40

Ring groove

41

Tool attack

42

ground

43

check valve

44

Sieve

45

Ring groove

58

Holes

59

Wall

Claims (10)

Hydraulic valve (12) for a swivel motor adjuster, in which a hollow piston (23) is guided within a bushing (22) which forms a main body of the hydraulic valve (12) and axially one after the other a radial oil supply connection (P), a first radial working connection (B ) and a second radial working connection (A), these working connections (B, A) assigned to these two opposite directions of rotation of the swivel motor adjuster being followed by a tank drain (T) which is arranged exclusively at one end of the hydraulic valve (12), the socket (22) circumferentially offset from the second working connection (A) has a tank drain channel (38) leading to the tank drain (T), - Which discharges the fluid from the first working connection (B) past the second working connection (A) when the latter is supplied with fluid from the oil supply connection (P) and - Which discharges the fluid from the second working connection (A) directly when the first working connection (B) is supplied with fluid from the oil supply connection (P), the tank drain channel (38) being delimited by a closed wall (59) of the bushing (22) . Hydraulic valve (12) after Claim 1 , characterized in that the first working connection (B) can be supplied with fluid from the oil supply connection (P) via a hydraulic current which runs radially between the hollow piston (23) and the bushing (22), whereas the second working connection (A) with fluid can be supplied from the oil supply connection (P) via a hydraulic current which runs inside the hollow piston (23). Hydraulic valve (12) according to one of the preceding claims, characterized in that a recess (17) is provided in the bushing (22) for the first working connection (B), a recess between this recess (17) and the oil supply connection (P) (18) is provided for the use of camshaft alternating torques. Hydraulic valve (12) after Claim 3 , characterized in that in the socket (22) On the inside of the two axially adjacent recesses (17, 18) of the first working connection (B) there is provided a radially inwardly projecting inner web, which together with an annular web (37) can form a sealing gap which allows the fluid exchange between the two axially adjacent recesses (17 , 18) blocks when a fluid flow is led from the oil supply connection (P) to the second working connection (A) and a separate fluid flow from the recess (17) of the first working connection (B) to the tank drain (T), so that from the recess (18 ) fluid is introduced into the first-mentioned fluid flow in order to use the camshaft alternating moments. Hydraulic valve (12) after Claim 3 or 4th , characterized in that check valves (39, 43) are inserted into the socket (22) on the inside of the recess (21) of the oil supply connection (P) and the recess (18) axially adjacent to this recess (21) in order to use the camshaft alternating torques. Hydraulic valve (12) after Claim 5 , characterized in that the check valves (39, 43) are band-shaped and are axially separated from one another by means of an inner web (4) projecting radially inward within the bushing (22). Hydraulic valve (12) according to one of the preceding claims, characterized in that a helical compression spring (29) is supported axially on the one hand on a bushing base made in one piece with the bushing and on the other hand on the hollow piston (23). Hydraulic valve (12) after Claim 7 , characterized in that the helical compression spring (29) is supported in relation to a closure body (36) which is inserted in the hollow piston (23). Hydraulic valve (12) according to one of the preceding claims, characterized in that an external thread is cut into the bushing (22) at the end opposite the tank outlet (T). Hydraulic valve (12) according to one of the preceding claims, characterized in that the hydraulic valve (12) is designed as a central valve.

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