DE102010060181A1 - Central valve for oscillating motor adjuster of assembled cam shaft, has hollow-piston inserted within bushing that is inserted within hollow pipe and supported along axial direction by clamping device inserted into hollow pipe - Google Patents

Abstract

The valve (12) has a bushing (15) inserted within a hollow pipe (16). A hollow-piston (19) is inserted within the bushing and axially displaceable by an electromagnetic actuator (21). The bushing is supported along axial direction by a clamping device (27) that is inserted into the hollow pipe. A helical compression spring (24) is supported at a bottom part (59) of the hollow-piston for pressing the hollow-piston against an operation plunger (20) of the actuator, where the operation plunger rests against another bottom part of the hollow-piston.

Description

The invention relates according to the preamble of claim 1, a central valve for a Schwenkmotorversteller.

From the DE 10 2005 048 732 A1 is already known a central valve for a Schwenkmotorversteller a built camshaft with a hollow tube. Within this hollow tube, a bushing is used, which has annular channels, so that regardless of the angular position of the sleeve relative to the hollow tube, a hydraulic pressure on the one or the other pressure chamber of the Schwenkmotorverstellers is transferable. Thus, the Schwenkmotorversteller is pivotable in one or the other direction. For distributing the hydraulic pressure, a piston axially displaceable by an electromagnetic actuator is inserted within the sleeve.

The DE 102 11 467 A1 concerns a central valve, which takes over the function of a so-called central screw and braces the rotor against the camshaft. Thus occur in a disadvantageous manner voltages in the hydraulic valve.

The US 6,968,816 B2 relates to a hydraulic valve having a bushing and a piston arranged inside thereof. According to an alternative torn only briefly this valve can also be arranged within the Schwenkmotorverstellers.

The object of the invention is to provide a small and efficient Schwenkmotorversteller for a built camshaft.

This object is achieved with the features of claim 1.

According to an advantage of the invention, the hydraulic valve of the Schwenkmotorverstellers is designed as a central valve. Such a central valve has space advantages. In addition to central valves, there are the external hydraulic valves for actuating the Schwenkmotorverstellers. In the external hydraulic valve, the hydraulic passages for adjusting the camshaft from Schwenkmotorversteller to a separate Steuertriebdeckel with the screwed there hydraulic valve or to the cylinder head with the screwed there hydraulic valve. The hydraulic lines from the swivel motor adjuster to the external hydraulic valve are associated with line losses. In addition, the controls of external hydraulic valve are not implemented as dynamic as the central valve. The likewise hydraulic central valve is arranged radially inside the rotor hub of the Schwenkmotorverstellers.

In this case, according to the invention, a clamping element is used, which supports a bushing of the central valve in the axial direction within a hollow tube of the built camshaft. A frictional clamping element allows a stepless axial fixability of the sleeve relative to the hollow tube. This stepless fixability makes it possible to compensate for production-related tolerances. This allows a direct contact of a plunger of the electromagnetic actuator on the piston, so that only a very short Axialhub needs to be provided in this electromagnetic actuator. This allows a short construction of the central valve and the necessary electromagnetic actuator. Thus, the arranged radially outside the central valve Schwenkmotorversteller can be made axially short.

Thus, the axial fixing of the sleeve relative to the hollow shaft is separated from the axial clamping of the rotor relative to the camshaft. This allows a great deal of freedom in comparison to central valves, which are also central screws, without having to consider structural mechanical problems. It must therefore find no high-strength material application. For example, as a material light metal - especially aluminum - find application. Also, the hydraulic control edges on the central valve can be designed precisely. On sealing rings - in particular O-rings - for gap bridging can be dispensed with. Since no large screw head on the central valve is necessary, but the central valve can be made with a relatively uniform outer diameter, only relatively little material must be used, which makes the central valve cost. In order to non-rotatably connect the rotor while still with the camshaft, the rotor may be welded or pressed with a micro-toothing. In a particularly advantageous embodiment, it is also possible to axially clamp the rotor with a nut against a shoulder on the camshaft. The nut can be screwed onto an external thread at the end of the camshaft. The mother keeps the central valve free of tension.

The claimed in claim 9 embodiment of the socket of the central valve without screw head is to be construed such that tolerances are disregarded. D. h., The outer diameter of the sleeve is also the same size as the inner diameter of the hollow tube, even when the socket is pressed with a transition fit or a slight interference fit into the hollow tube. In this case, the outer diameter of the sleeve is slightly larger than the inner diameter of the hollow tube due to tolerances.

The supply pressure can be supplied in a particularly advantageous manner via the camshaft. In particular, a supply via the camshaft bearing is possible.

The supply pressure can also be introduced axially end face in the socket.

The piston is completely pressure balanced in a particularly advantageous embodiment.

In a particularly advantageous embodiment, the same clamping element supports the bushing in the two axial directions.

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

The invention is explained in more detail below with reference to two exemplary embodiments.

Show

1 a Schwenkmotorversteller in a sectional view,

2 the Schwenkmotorversteller off 1 wherein this is set to a hollow shaft, within which a central valve is inserted with a clamping element,

3 in a detail the central valve with the clamping ring and

4 disassembly of the central valve with built-in camshaft.

With a Schwenkmotorversteller 14 according to 1 During operation of an internal combustion engine, the angular position at the in 2 apparent camshaft 18 opposite a drive wheel 2 infinitely changed. By turning the camshaft 18 The opening and closing times of the gas exchange valves are shifted so that the internal combustion engine brings its optimum performance at the respective speed. The Schwenkmotorversteller 14 has a cylindrical stator 1 on, the rotation with the drive wheel 2 connected is. In the embodiment, the drive wheel 2 a sprocket over which a chain, not shown, is guided. The drive wheel 2 but may also be a toothed belt, over which a drive belt is guided as a drive element. About this drive element and the drive wheel 2 is the stator 1 Driven with the crankshaft.

The stator 1 comprises a cylindrical stator base body 3 , on the inner side radially inwardly at equal intervals webs 4 protrude. Between neighboring bridges 4 become spaces 5 formed, into, over, a in 2 closer illustrated central valve 12 controlled, pressure medium is introduced. Between neighboring bridges 4 protrude wings 6 radially outward from a cylindrical rotor hub 7 a rotor 8th protrude. These wings 6 divide the spaces between 5 between the bridges 4 each in two pressure chambers 9 and 10 ,

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

The rotor 8th is non-rotatable with the camshaft 18 connected. To the angular position between the camshaft 18 and the drive wheel 2 to change, the rotor becomes 8th relative to the stator 1 turned. For this purpose, depending on the desired direction of rotation, the pressure medium in the pressure chambers 9 or 10 pressurized while each other's pressure chambers 10 or 9 be relieved to the tank. To the rotor 8th opposite the stator 1 to pivot counterclockwise in the position shown, is from the central valve 12 a in 2 apparent annular rotor channel 13 in the rotor hub 7 pressurized by this rotor channel 13 then lead other channels 11 in the pressure chambers 10 , To the rotor 8th however, to pivot clockwise, is from the central valve 12 a in 2 apparent annular rotor channel 58 in the rotor hub 7 put under pressure. These two rotor channels 13 . 58 are with respect to a central axis 22 axially spaced from each other.

The rotor 8th is by means of a compensation spring 17 against the stator 1 torsionally elastic biased and on the camshaft 18 plugged.

2 shows a perspective cut representation of the Schwenkmotorverstellers 14 , which on the built camshaft 18 is attached and by means of the central valve 12 is pivotable.

For this purpose, the built camshaft 18 a hollow tube 16 on, in which cam in a manner not shown are pressed to actuate the gas exchange valves. An additional micro-toothing increases this interference fit or adds a slight positive fit. Inside the hollow tube 16 is a central valve 12 associated socket 15 used coaxially. In this socket 15 is a hollow piston 19 against the force of a helical compression spring 24 slidably guided. For this purpose, the helical compression spring is supported 24 on the one hand on a floor 59 of the piston 19 and on the other hand camshaft interior end 46 the socket 15 over a spring plate 67 from.

At the camshaft outer end of the socket 15 lies on the piston 19 a pestle 20 an electromagnetic actuator 21 on that in an anchor 23 is plugged in. To create a contact surface for an investment sphere 25 of the plunger 20 is in the pistons 19 a pen 26 pressed. The socket 15 is by means of an annular clamping element 27 opposite the hollow tube 16 axially supported, so that the piston 19 when shifting not the jack 15 over the helical compression spring 24 with shifts.

This supports the clamping element 27 the socket 15 in both axial directions against the hollow tube 16 from, so that a shift in both axial directions is prevented, unless a release force is exceeded.

The hollow piston 19 has five circumferential tax grooves 28 to 32 on, which together with four inner ring grooves 33 to 36 the socket 15 form so-called control edges. In the axial positions of the inner ring grooves 33 to 36 are four through holes 37 to 40 intended. These through holes 37 to 40 lead into ring channels 41 to 44 , so that regardless of the angular position of the socket 15 opposite the hollow tube 16 a hydraulic pressure on the one pressure chambers 9 or the other pressure chambers 10 of the Schwenkmotorverstellers 14 is transferable. The hydraulic pressure from the supply port P comes through the axially innermost annular channel 41 , in which an annular and band-shaped sieve 60 is used. From the supply port P, the hydraulic pressure through an opening 61 in the wall of the hollow piston 19 in its interior 62 passed, from which the Hydraulikfkluid through another opening 63 to the ring channel 44 is directed. This ring channel 44 is associated with a direction of rotation, wherein the hydraulic fluid from the other direction of rotation associated annular channel 43 to the ring channel 42 is passed, which is associated with a first tank drain T1. Will the piston 19 from the actuator 21 displaced maximally inward, so the hydraulic fluid from the annular channel 44 directed to a second tank drain T2. This second tank outlet T2 leads axially out of the socket 15 and the hollow shaft 16 out, so that the hydraulic fluid drips into a chain box. The first tank drain T1, however, lies axially between a cylinder head housing 64 and the swing motor camshaft adjuster 14 , The first tank drain T1 leads through a bearing ring 65 through which also the supply terminal P runs. At this bearing ring 65 is also a paragraph 66 arranged against which the rotor 8th by means of a on the hollow shaft 16 screwed nut 47 is tense.

The hollow piston 19 is closed on both sides by means of shelves. In this case, the axially inside bottom of said floor 67 formed, whereas the axially outside bottom of the pin 26 is formed.

• – Kolben 19,
• – Stift 26,
• – Buchse 15,
• – Hohlrohr 16 und
• – Stellglied 21

kompensierbar. Dies ermöglicht es, das elektrische Stellglied 21 mit sehr kleinen Axialhüben auszuführen und damit sehr kurz zu bauen.The tensioning element 27 is designed as a sheet metal ring in a groove 49 the socket 15 attacks. This sheet metal ring has an axial clamping area 48 on, at the two axial boundary walls 50 . 51 the groove 49 is applied. This is the clamping range 48 curled. The metal ring has a U-profile. Two bridges 52 . 53 this U-profile protrude radially inward, whereas the intermediate region 54 Frictionally engaged on the inner wall under tension 67 of the hollow tube 16 is applied. To produce the voltage, the sheet metal ring in the disassembled state has a larger outer diameter and is with a gap 55 Mistake. Due to the frictionally infinitely variable axial positioning, the tolerances of the components

• - Piston 19 .
• - Pen 26 .
• - Rifle 15 .
• - hollow tube 16 and
• - actuator 21

compensated. This allows the electric actuator 21 To execute with very small Axialhüben and thus very short to build.

• – Zylinderkopfgehäuse 64,
• – Nockenwelle 18,
• – diverse Abdeckungen, wie ein Kettenkasten und
• – der Spurlagerposition

vorgesehen sein.Due to this, further, significantly larger tolerances can also be applied to the surrounding components / geometries:

• - Cylinder head housing 64 .
• - Camshaft 18 .
• - various covers, such as a chain case and
• - the track storage position

be provided.

3 shows the area around the clamping element 27 in a detail.

The axially inner web 52 forms the axial clamping area 48 , On the other hand serves the axially outer web 53 as a tool attack. So it is with dismantled actuator 21 possible with a tool behind this axially outer web 53 to grab and the socket 15 or the entire central valve 12 from the hollow tube 16 to pull out. Depending on the available installation space in the area of the removed actuator 21 It may be necessary, the almost completely withdrawn central valve 12 to topple over in the last millimeters, as in 4 is apparent. This is the axially inner end 68 the socket 15 provided with a smaller diameter. To prevent the piston during assembly / disassembly 19 from the socket 15 slips out, is in an inner ring groove 56 the socket 15 a circlip 57 used in wire.

In an alternative embodiment of the invention, the clamping element supports the socket 15 only in the one axial direction relative to the hollow tube. For the other axial direction another support measure is provided. For example, a second clamping element may be provided. Likewise, an axial stop within the camshaft is possible.

In a further alternative embodiment of the invention, to facilitate the assembly / disassembly of the two of the gap 55 be provided separate ends of the clamping element tool attacks. For example, holes may be drilled or stamped, such as those of circlips, for example DIN 472 are known. These holes then allow the clamping element to be compressed and the gap width to be reduced in order to release or reduce the frictional engagement. Other shapes as a tool attack are also conceivable. These other shapes may be, for example, noses, hooks, beads, internal threads or material recesses. Alternatively, additional components, such as pressed-in bolts, are possible.

The bush can be, for example, a turned part or manufactured in aluminum die cast and / or be ground.

The through holes 37 to 40 in the axial positions of the inner ring grooves 33 to 36 can be executed in different configurations. So it is possible, one through the two diametrical pipe wall portions of the socket 15 to create continuous through holes. Also, further through holes on the circumference of the socket 15 - For example, at an angle of 90 ° to the first-mentioned through holes - be provided. But it is also possible to provide instead of through holes such holes that go only through a pipe wall area and thus do not go through the diametrically arranged pipe wall area. It must also not exactly four holes / through holes axially spaced from each other. So it is also possible to provide more holes / through holes, which are associated with, for example, an additional use of the camshaft alternating torques for a faster / more efficient adjustment.

Instead of the piston 19 pressed pen 26 may be the bottom on the part of the actuator 21 also be executed differently. For example, a floor designed as a ball or cap can also be provided.

The tensioning element 27 does not have to be a metal ring that fits into a groove 49 the socket 15 attacks. There are also other versions feasible. For example, detents or clip connections and also a bayonet closure are feasible.

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

stator

2

drive wheel

3

stator base

4

Stege

5

interspaces

6

wing

7

rotor hub

8th

rotor

9

pressure chambers

10

pressure chambers

11

channels

12

central valve

13

rotor channel

14

Schwenkmotorversteller

15

Rifle

16

hollow tube

17

compensation spring

18

camshaft

19

piston

20

tappet

21

actuator

22

central axis

23

anchor

24

Helical compression spring

25

plant ball

26

pen

27

clamping ring

28

control groove

29

control groove

30

control groove

31

control groove

32

control groove

33

inner annular

34

inner annular

35

inner annular

36

inner annular

37

Through holes

38

Through holes

39

Through holes

40

Through holes

41

annular channel

42

annular channel

43

annular channel

44

annular channel

45

channel

46

channel

47

mother

48

clamping range

49

groove

50

boundary wall

51

boundary wall

52

web

53

web

54

Area

55

gap

56

inner annular

57

circlip

58

rotor channel

59

ground

60

scree

61

opening

62

inner space

63

further opening

64

Cylinder head housing

65

bearing ring

66

paragraph

67

spring plate

68

inner wall

69

Inner end of the socket

QUOTES INCLUDE IN THE DESCRIPTION

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

Cited patent literature

• DE 102005048732 A1 [0002]
• DE 10211467 A1 [0003]
• US 6968816 B2 [0004]

Cited non-patent literature

• DIN 472 [0038]

Claims (9)

Central valve ( 12 ) for a Schwenkmotorversteller ( 14 ) a built camshaft ( 18 ) with a hollow tube ( 16 ) within which a socket ( 15 ) within which one of an electromagnetic actuator ( 21 ) axially displaceable piston ( 19 ), characterized in that the bushing ( 15 ) by means of a in the hollow tube ( 16 ) used clamping element ( 27 ) is supported in the one axial direction. Central valve according to claim 1, characterized in that the hollow tube ( 16 ) by means of the same clamping element ( 27 ) is supported in both axial directions. Central valve according to claim 1, characterized in that the hollow tube is supported by means of a further clamping element in the other axial directions relative to the hollow tube. Central valve according to one of the preceding claims, characterized in that the piston ( 19 ) is hollow and is closed on both sides by means of floors, wherein at one bottom ( 59 ) a helical compression spring ( 24 ), which endeavors to move the piston ( 19 ) against an actuating tappet ( 20 ) of the actuator ( 21 ), which at the other bottom of the piston ( 19 ) is present. Central valve according to one of the preceding claims, characterized in that the other bottom one from the piston ( 19 ) is a separate component, which with the piston ( 19 ) connected is. Central valve according to one of the preceding claims, characterized in that a rotor ( 8th ) of the Schwenkmotorverstellers ( 14 ) by means of a on the end of the hollow tube ( 16 ) screwed nut ( 47 ) firmly against a shoulder on the camshaft ( 18 ) is braced. Central valve according to one of the preceding claims, characterized in that the clamping element ( 27 ) is a sheet metal ring which is in a groove ( 49 ) of the socket ( 15 ) attacks. Central valve according to Patent Claim 8, characterized in that the sheet-metal ring has an axial clamping region which, at the two axial boundary walls ( 50 . 51 ) of the groove ( 49 ) is present. Central valve according to one of the preceding claims, characterized in that all diameters of the bushing ( 15 ) equal to the inner diameter of the hollow tube ( 19 ) or smaller than this inner diameter of the hollow tube ( 19 ) are.

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