DE102014108700A1 - Central actuator for a Schwenkmotorversteller a camshaft - Google Patents

Abstract

The invention relates to a central actuator (10), in particular for a solenoid valve of a Schwenkmotornockenwellenverstellers comprising a pole tube (12) which is disposed within at least one magnetic field generating coil (52) and at a first end (16) a pole tube region (14). having. The central actuator (10) further includes a termination member (18) terminating the first end (16) of the pole tube (12), the termination member (18) including at least one pole core insert (22) having a central bore (24) and one in the and an actuating tappet (20) which is supported on an armature (28), which in the pole tube (12) in the pole core (22) facing axial direction (L) is designed to be displaceable. In this case, the actuating plunger (20) in the bearing bush (26) is mounted axially displaceable, and the armature (28) by means of a on its outer circumference (44) arranged bearing ring (36) mounted on a part of its axial length in the pole tube (12).

Description

Technical area

The invention relates to a central actuator, in particular for a solenoid valve of a Schwenkmotornockenwellenverstellers an internal combustion engine of a motor vehicle.

State of the art

From the DE 10 2005 049 663 A1 An electromagnet is known having a cylindrical hollow magnet body having a yoke, a pole core with a characteristic influencing armature counterpart and a housing, and a cylindrical coil and a cylindrical armature with guide rod and armature piston which is slidably disposed to the pole.

In the electromagnet of the armature piston is mounted axially displaceably in a bearing tube or a bearing sleeve, wherein the bearing tube or the bearing sleeve ends at one end within the pole core or within the armature counterpart of the pole core and at another end to over the yoke, in particular up to the local Transverse wall of the housing extends, and at this end in the case of training as a bearing sleeve has the sleeve bottom.

The armature piston is mounted centrally in the region of the pole core or the armature counterpart of the pole core in a bearing tube or a bearing sleeve, which consists of thin, hard material and has a precisely defined inner and outer diameter and a precisely defined wall thickness, wherein the bearing tube or the sleeve non-magnetic material. The bearing tube or the bearing sleeve is disposed within the armature counterpart forming part of the pole core and is not performed as before around this part outside.

The anchor piston has at each end provided on its circumference bearing point, which bears against the inner surface of the bearing tube or the bearing sleeve. There are provided in particular at the two ends of the bearing piston two fixed on its circumference bearing points, which allow a transition of the magnetic lines of force on the armature or the armature piston.

Disclosure of the invention

An object of the invention is to provide a cost-effective to manufacture central actuator, in particular for a solenoid valve of a Schwenkmotornockenwellenverstellers, which can be operated wear-resistant with low friction.

The above object is achieved according to one aspect of the invention with the features of the independent claims.

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

It is proposed a central actuator, in particular for a solenoid valve of a Schwenkmotornockenwellenverstellers comprising a pole tube, which is disposed within at least one coil generating a magnetic field and having at a first end a Polrohrbereich. Furthermore, the central actuator comprises a closing element which closes off the first end of the pole tube, the closing element comprising at least one pole core insert with a central bore and a bearing bush arranged in the central bore of the pole core insert, and an actuating tappet supported on an armature, which in the pole tube is designed to be displaceable in the pointing in the direction of the Polkerneinsatz axial direction. In this case, the actuating plunger is mounted axially displaceably in the bearing bush, and the armature mounted by means of a bearing ring arranged on its outer circumference on a part of its axial length in the pole tube.

According to the invention, on the one hand, it is provided for this purpose that the pole tube has a continuous inner diameter over the entire work area crossed over by the armature. Thus, the anchor is guided over its entire length. This ensures that the armature can not tilt, which would otherwise lead to high magnetic radial forces on the armature and thus to a high friction against the pole tube. The armature can either be operated dry when the central actuator is sealed against the hydraulic fluid with which a connected solenoid valve is operated, or else with hydraulic fluid, for example with hydraulic oil operated. According to a further advantage, as a result of the continuous inside diameter, relatively heavily polluted hydraulic fluid can be used without there being any high wear endangering the function of the central actuator. High particle concentrations in the hydraulic fluid would otherwise lead to disproportionately high wear, especially at high radial forces.

The at least one coil may be cylindrical, for example. The first end with the pole tube region may expediently be an open end of the pole tube. The pole tube region can advantageously taper in an axial direction away from the first end, so that the outer diameter of the pole tube region becomes smaller at the transition to the adjacent region of the pole tube is as remote from it in the direction of the first end of the pole tube.

The reduction of wear is associated with an increase in the service life. In addition, the mechanical and the magnetic hysteresis is reduced, whereby a solenoid valve of a Schwenkmotornockenwellenverstellers operated via the central actuator can be better controlled. Also, it can be used to reduce the installation space of the coil and the outer dimensions of the solenoid valve. The so-called mechanical hysteresis is determined by the ratio of the guide length of the armature to the diameter.

According to the invention, it is thus advantageously possible to make the anchor relatively small in diameter, which is good for the dynamics and the ratio of anchor length to anchor diameter. Thus, it is also possible to arrange the control cone of the cone-shaped tapered pile tube region on a small diameter.

In an advantageous embodiment of the Polkerneinsatz may have on its outer circumference arranged in the axial direction recesses for pressure equalization between the armature space and the outer space of the central actuator. The pressure balance ensures a volume balance of the trapped hydraulic fluid or trapped air between the armature space and an outer space of the central actuator. Such pressure equalization is important both in dry operation, ie air-filled armature space, and thus also in operation with hydraulic fluid in the armature space. Even if hydraulic fluid has to be kept out of the area outside the pole tube, this hydraulic fluid within the pole tube is nevertheless of great advantage, since it can create a pressure equalization on both sides of the anchor. For this purpose, in a particularly advantageous embodiment, recesses are provided in the pole core insert which guide the hydraulic fluid from the hydraulic part of a solenoid valve to the electromagnetic part of the solenoid valve, ie the central actuator, in such a way that the pole core insert is subjected to the same hydraulic pressure on both sides.

Conveniently, the recesses of the Polkerneinsatzes be made by whipping. Turning is a very cost-effective manufacturing process that allows a surface machining on a lathe and is thus advantageous for the production of the recesses according to the invention on the outer circumference of the Polkerneinsatzes suitable.

In an expedient embodiment, the pole core insert can be pressed into the first end of the pole tube region. As a result, a firm and secure fit of the Polkerneinsatzes in the pole tube, in particular in the cone-shaped tapered pole tube area possible.

In this way, a permanent connection between pole tube and Polkerneinsatz be created, which holds even with shocks, as they are common in operation on an internal combustion engine safely.

In an advantageous embodiment of the bearing ring may have on its outer circumference extending in the axial direction recesses, which cause pressure equalization between the front of the armature and the back of the armature along the bearing surface. The pressure equalization is important again for dry operation, ie with air in the armature space, as well as for operation under hydraulic fluid in the armature space. Even if hydraulic fluid has to be kept out of the area outside the pole tube, this hydraulic fluid within the pole tube is nevertheless of great advantage, since it can create a pressure equalization on both sides of the anchor. For this purpose, recesses in the bearing ring of the armature are present in a particularly advantageous embodiment, which guide the hydraulic fluid from the hydraulic part of a solenoid valve to the electromagnetic part of the solenoid valve, so the central actuator, such that the armature is acted upon on both sides with the same hydraulic pressure.

Conveniently, the bushing may have on its side facing the armature a collar as a stop of the armature in its axial movement. Such a fixed stop holds the end face of the armature at a certain distance from the disc-shaped pole core insert and thus prevents sticking of the armature to the end face of the armature on the Polkerneinsatz. Gluing would change the movement behavior of the armature and significantly affect the magnetic forces necessary to operate the armature, thereby changing the overall dynamic behavior of the central actuator. Therefore, such a covenant as an anti-stick disc can positively influence the dynamic behavior as well as the energy consumption of a central actuator operated by magnetic forces.

Advantageously, the actuating tappet can be pressed into a central bore of the armature. Anchors and actuating tappets are usually made of different materials.

The armature is preferably formed of soft iron, while the actuating plunger is made for example of non-ferrous metal to have the necessary material properties such as hardness for the operation of a solenoid valve. Of the However, armature must have substantially the correct magnetic properties to operate in the magnetic circuit of the coil. Therefore, for example, the armature can be provided with a bore into which the actuating tappet can be inserted, wherein it can preferably be pressed in, which produces a cost-effective and durable connection between armature and actuating tappet.

In an advantageous embodiment, a pole yoke can surround the coil on its outer sides, wherein the pole yoke can have a cover plate in a transverse surface to the axial direction. The yoke ensures that the magnetic field generated by the coil is guided and amplified in a closed space, so that the coil is conveniently enclosed on all sides with a sheath of magnetic material, wherein the area inside the coil is closed by the pole tube.

Conveniently, the pole tube region can be pressed into an opening of the end plate. According to a further advantage of the invention, the pole tube extends from a pole yoke to the end plate, which seals the interior of the coil against ingress of hydraulic fluid. This ensures that the hydraulic fluid can not crawl into a column of the central actuator lying outside the pole tube. Thus, it is also prevented that hydraulic fluid can escape from the housing of the central actuator or can get to the electrical contact with the coil or to a connector. Accordingly, the sealing arrangement according to the invention is particularly advantageous when the hydraulic fluid in the region of the pole tube is under pressure.

Due to the creeping ability of the warm hydraulic fluid, however, the embodiment according to the invention seals also makes sense in solenoid valves in which the hydraulic fluid in the region of the pole tube rests under tank pressure. It also makes sense with central actuators, the pole tube in the interior installation is only in the oil mist.

In an alternative embodiment, the actuating tappet may be formed of a soft magnetic material. Such an embodiment may be advantageous if the actuating tappet is to be included in the magnetic circuit in order to have the highest possible magnetic force for driving the Zentralaktuators available as compact as possible design. It would also be possible to perform anchor and actuating plunger in one piece, whereby a good coaxiality of the two components armature and actuating plunger can be achieved at low manufacturing costs. Anchor and actuating tappets could thus be produced, for example, in one piece as a turned part made of free-cutting steel.

In an advantageous embodiment, the bearing bush can be produced by a plastic injection molding process. Thus, in a particularly advantageous embodiment of the invention, plastic injection molded parts with inserts can be used. As plastic injection molded part, for example, the bearing bush with the Polkerneinsatz comes into consideration. As a result, a permanent sealing of the bearing bush is given against the Polkerneinsatz. In addition, the plastic injection molding process is a very cost-effective manufacturing process.

Advantageously, a housing enclosing the central actuator may be manufactured by a plastic injection molding process. In this way, it is possible in a cost effective manner to manufacture the housing of the central actuator of injection-molded plastic, provided that the various components of the yoke are inserted in the injection molding process, which ensure the closed magnetic flux. The end of the housing against an external space of the central actuator then forms the end plate with pressed-pole tube, as well as also pressed-in end element of Polkerneinsatz and bearing bush.

 Brief description of the drawings

Further advantages emerge from the following description of the drawing. In the drawings, embodiments of the invention are shown. The drawings, the description and the claims contain numerous features in combination. The person skilled in the art will expediently also consider the features individually and combine them into meaningful further combinations.

They show by way of example:

1 a section through a central actuator according to an embodiment of the invention;

2 a Polkerneinsatz in plan view according to an embodiment of the invention; and

3 a bearing ring in plan view according to an embodiment of the invention.

Embodiments of the invention

In the figures, the same or similar components are numbered with the same reference numerals. The figures are merely examples and are not intended to be limiting.

1 shows a section through a central actuator 10 according to an embodiment of the invention. The central actuator 10 , which is particularly suitable for a solenoid valve of a Schwenkmotornockenwellenverstellers, in this case comprises a pole tube 12 that within a cylindrically shaped, a magnetic field generating coil 52 is arranged and at a first, open end 16 an in a axial direction L tapered pole tube area 14 having. Furthermore, the central actuator comprises 10 a conclusion element 18 which is the first end 16 of the pole tube 12 completes, with the final element 18 a Polkernleinsatz 22 with a central bore 24 and one in the central hole 24 of the Polkerneinsatzes 22 arranged bearing bush 26 includes, as well as an actuating tappet 20 holding an anchor 28 is supported, which in the pole tube 12 in the on the Polkerneinsatz 22 pointing axial direction L is designed to be displaceable. The actuating tappet 20 is in the bushing 26 mounted axially displaceable while the anchor 28 by means of one on its outer circumference 44 arranged bearing ring 36 on a part of its axial length in the pole tube 12 is stored. The anchor 28 can be so in the pole tube 12 , which can be designed as a rotating part and therefore has a smooth inner surface, move as smoothly as possible.

The Polkerneinsatz 22 indicates on its outer circumference 56 in the axial direction L arranged recesses 32 for pressure equalization between armature space 60 and outdoor space 54 of the central actuator 10 on, with the recesses 32 of the Polkerneinsatzes 22 can be produced for example by whipping. The pressure balance provides a volume balance of the trapped hydraulic fluid or trapped air between the armature space 60 and an outer space of the central actuator 10 for sure. Such a pressure equalization is both in dry operation, so air-filled armature space 60 , so also when operating with hydraulic fluid in the armature space 60 significant. The Polkerneinsatz 22 is in the first end 16 of the pole tube area 14 be pressed.

The bearing ring 36 points to its outer circumference 58 in the axial direction L extending recesses 38 on, along the bearing surface 62 a pressure equalization between the front 64 of the anchor 28 and the back 66 of the anchor 28 cause. The pressure equalization is again for dry operation, ie with air in the armature space 60 , as well as for operation under hydraulic fluid in the armature space 60 significant. Even if hydraulic fluid from outside the pole tube 12 must be kept out, so this hydraulic fluid is inside the pole tube 12 yet of great benefit as there is a pressure equalization on both sides of the anchor 28 can create. For this purpose, recesses are in a particularly advantageous embodiment 38 in the bearing ring 36 of the anchor 28 present, the hydraulic fluid from the hydraulic part of a solenoid valve to the electromagnetic part of the solenoid valve, so the central actuator 10 , so pass through that anchor 28 is acted upon on both sides with the same hydraulic pressure.

The bearing bush 26 points to her the anchor 28 facing side a covenant 40 as a stop of the anchor 28 during its axial movement. Such a firm stop holds the front of the anchor 28 at a certain distance from the disc-shaped pole core insert 22 and thus prevents sticking of the anchor 28 with the front of the anchor 28 at the Polkerneinsatz 22 , Gluing would change the movement behavior of the anchor 28 change and the operation of the anchor 28 necessary magnetic forces significantly affect, so that the entire dynamic behavior of the central actuator 10 would be changed. That's why such a covenant 40 as an anti-stick disc the dynamic behavior as well as the energy consumption of a central actuator 10 , which is operated with magnetic forces, positively influence. The bearing bush 26 itself is produced for example by a plastic injection molding process.

The actuating tappet 20 is in a central hole 30 of the anchor 28 be pressed. When the actuating plunger 20 made of a different material than the anchor 28 is executed, this represents a favorable solution of the connection between the two components. If both components should be made of the same material, for example, for magnetic reasons, then it is also conceivable that anchor 28 and actuating tappets 20 are made in one piece. The actuating tappet 20 Thus, in an alternative embodiment of a soft magnetic material, as well as the anchor 28 be formed. This makes it possible to build a compact actuator as compact as possible.

The pole yoke 50 , which may be formed of a plurality of plates and / or tubes, surrounds the coil 52 on their outsides, being the pole yoke 50 in a transverse surface to the axial direction L, an end plate 42 having. That way is the coil 52 surrounded as completely as possible by magnetic material, as inside the coil 52 the pole tube 12 is trained. This will be the one from the coil 52 generated magnetic flux as low as possible to the volume range in which the anchor 28 can move, concentrated.

The pole tube area 14 is in an opening 68 the end plate 42 einpressbar, so as to enter as solid as possible and permanent connection. This will also provide a permanent seal on the area of the coil 52 to the outside area 54 as well as the anchor space 60 created so that the coil 52 so permanently sealed against the hydraulic fluid. The hydraulic fluid could possibly attack the insulation of the coil wire as well as the electrical leads.

The housing 46 , which encloses the central actuator, is manufactured by a plastic injection molding process. The conclusion of the case 46 against an outdoor space 54 of the central actuator 10 then forms the end plate 42 with pressed in pole tube 12 including pole tube area 14 , as well as pressed-in closing element 18 made of Polkerneinsatz 22 and bearing bush 26 ,

2 provides a Polkerneinsatz 22 in plan view according to an embodiment of the invention. The Polkerneinsatz 22 is designed as a disk-shaped component with a round cross-section, which has a central bore 24 as well as recesses 32 on its outer circumference 56 for pressure equalization between armature space 60 and outdoor space 54 of the central actuator 10 having. The pressure balance provides a volume balance of the trapped hydraulic fluid or trapped air between the armature space 60 and an outer space of the central actuator 10 for sure. Such a pressure equalization is both in dry operation, so air-filled armature space 60 , so also when operating with hydraulic fluid in the armature space 60 significant. Even if hydraulic fluid from outside the pole tube 12 must be kept out, so this hydraulic fluid is inside the pole tube 12 yet of great benefit as there is a pressure equalization on both sides of the anchor 28 can create. For this purpose, recesses are in a particularly advantageous embodiment 32 in Polkerneinsatz 22 present, the hydraulic fluid from the hydraulic part of a solenoid valve to the electromagnetic part of the solenoid valve, so the central actuator 10 , so pass through, that the Polkerneinsatz 22 is acted upon on both sides with the same hydraulic pressure.

The hole 24 serves to accommodate the bearing bush 26 , The Polkerneinsatz 22 is preferably made of soft magnetic material and can be used as Einlegteil in plastic injection molding process for producing the bearing bush 26 be provided. In this way, a secure and permanent connection between bushing 26 and Polkernereinsatz 22 created.

3 shows a bearing ring 36 in plan view according to an embodiment of the invention. The bearing ring 36 can be performed in plastic such as PTFE and serves to support and guide the anchor 28 on a part of his coat length. The anchor 28 is so by means of on its outer circumference 44 arranged bearing ring 36 on a part of its axial length in the pole tube 12 stored and can be so in the pole tube 12 , which can be designed as a rotating part and therefore has a smooth inner surface, move as smoothly as possible. The bearing ring 36 indicates on its outer circumference 58 recesses 38 on, along the bearing surface 62 a pressure equalization between the front 64 of the anchor 28 and the back 66 of the anchor 28 cause. The pressure equalization is again for dry operation, ie with air in the armature space 60 , as well as for operation under hydraulic fluid in the armature space 60 significant. Even if hydraulic fluid from outside the pole tube 12 must be kept out, so this hydraulic fluid is inside the pole tube 12 yet of great benefit as there is a pressure equalization on both sides of the anchor 28 can create. For this purpose, recesses are in a particularly advantageous embodiment 38 in the bearing ring of the anchor 28 present, the hydraulic fluid from the hydraulic part of a solenoid valve to the electromagnetic part of the solenoid valve, so the central actuator 10 , so pass through that anchor 28 is acted upon on both sides with the same hydraulic pressure.

LIST OF REFERENCE NUMBERS

 10

Zentralaktuator

12

pole tube

14

Polrohrbereich

16

End pole tube

18

termination element

20

actuating ram

22

Polkerneinsatz

24

drilling

26

bearing bush

28

anchor

30

Bore anchor

32

Recess Polkerneinsatz

34

Rejuvenation Polkern

36

bearing ring

38

Recess bearing ring

40

Bearing bushing

42

End plate

44

Outer circumference anchor

46

casing

50

yoke

52

Kitchen sink

54

outer space

56

Outer circumference Polkerneinsatz

58

Outer circumference of bearing ring

60

armature space

62

Bearing shell surface

64

Front anchor

66

Back anchor

68

Opening end plate

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 102005049663 A1 [0002]

Claims (12)

Central actuator ( 10 ), in particular for a solenoid valve of a Schwenkmotornockenwellenverstellers, comprising - a pole tube ( 12 ), which within at least one magnetic field generating coil ( 52 ) and at a first end ( 16 ) a pole tube area ( 14 ), - a terminating element ( 18 ), which is the first end ( 16 ) of the pole tube ( 12 ), the terminating element ( 18 ) at least one Polkerneinsatz ( 22 ) with a central bore ( 24 ) and one in the central bore ( 24 ) of the Polkerneinsatzes ( 22 ) arranged bushing ( 26 ), - an actuating tappet ( 20 ) attached to an anchor ( 28 ), which in the pole tube ( 12 ) in the on the Polkerneinsatz ( 22 ) facing axial direction (L) is designed to be displaceable, wherein the actuating plunger ( 20 ) in the bearing bush ( 26 ) is mounted axially displaceable, and wherein the armature ( 28 ) by means of one on its outer periphery ( 44 ) arranged bearing ring ( 36 ) on a part of its axial length in the pole tube ( 12 ) is stored. Central actuator according to claim 1, wherein the pole core insert ( 22 ) on its outer circumference ( 56 ) in the axial direction (L) arranged recesses ( 32 ) for pressure equalization between armature space ( 60 ) and outdoor space ( 54 ) of the central actuator. Central actuator according to claim 2, wherein the recesses ( 32 ) of the Polkerneinsatzes ( 22 ) are produced by whipping. Central actuator according to one of the preceding claims, wherein the pole core insert ( 22 ) in the first end ( 16 ) of the pole tube region ( 14 ) is einpressbar. Central actuator according to one of the preceding claims, wherein the bearing ring ( 36 ) on its outer circumference ( 58 ) in the axial direction (L) extending recesses ( 38 ), which along the bearing surface ( 62 ) a pressure equalization between the front ( 64 ) of the anchor ( 28 ) and the back ( 66 ) of the anchor ( 28 ) cause. Central actuator according to one of the preceding claims, wherein the bearing bush ( 26 ) on her the anchor ( 28 ) facing side a bunch ( 40 ) as a stop of the anchor ( 28 ) in its axial movement. Central actuator according to one of the preceding claims, wherein the actuating tappet ( 20 ) in a central bore ( 30 ) of the anchor ( 28 ) is einpressbar. Central actuator according to one of the preceding claims, wherein a pole yoke ( 50 ) the sink ( 52 ) encloses on its outer sides and wherein the Poljoch ( 50 ) in a transverse surface to the axial direction (L) a closure plate ( 42 ) having. Central actuator according to claim 8, wherein the pole tube region ( 14 ) in an opening ( 68 ) of the end plate ( 42 ) is einpressbar. Central actuator according to one of the preceding claims, wherein the actuating tappet ( 20 ) is formed of a soft magnetic material. Central actuator according to one of the preceding claims, wherein the bearing bush ( 26 ) is produced by a plastic injection molding process. Central actuator according to claim 11, wherein a housing ( 46 ), which encloses the central actuator, is made by a plastic injection molding process.

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