DE102014114847A1 - Electromagnetic actuator for a camshaft adjuster - Google Patents

Abstract

The invention relates to an electromagnetic actuator (10) having a central axis (L1), in particular for actuating a hydraulic valve (50) of a camshaft adjuster (100) having a coil (12) formed around the center axis (L1) and an armature (14). comprising an actuating pin (16) arranged in the axial direction. Further, the armature (14) is rotatable relative to the coil (12) about the axis (L1) and when energized, the coil (12) depending on the current direction along the axis (L1) up or down slidably. The actuating pin (16) is designed to actuate a piston (52) of a hydraulic valve (50) of a camshaft adjuster (100) as intended. The invention further relates to a camshaft adjuster (100) with such an electromagnetic actuator (10).

Description

Technical area

The invention relates to an electromagnetic actuator, in particular for actuating a hydraulic valve of a camshaft adjuster on an internal combustion engine of a motor vehicle.

State of the art

From the DE 10 2010 060 181 B4 is a hydraulic valve of a camshaft adjuster known, which is designed as a central valve. The hydraulic central valve is arranged radially inside the rotor hub of the camshaft adjuster. In this case, a clamping element is used, which supports a bushing of the central valve in the axial direction within a hollow tube of a built camshaft. A frictional clamping element allows a stepless axial fixability of the bushing with respect to the hollow tube, so as to compensate for production-related tolerances. This allows a direct contact of a plunger of an electromagnetic actuator on the piston, so that only a very short Axialhub is provided in this electromagnetic actuator.

From the DE 10 2013 101 737 A1 Further, a sealing device for a camshaft adjuster is known, which is driven by means of a belt and having a directional control valve with a piston, wherein the sealing means a first fastening portion which is fixedly arranged on the camshaft adjuster, a second fastening portion, which is fixedly mounted on the piston side, and a Has between the first mounting portion and the second mounting portion disposed flexible diaphragm portion. The phaser has a belt drive region and a valve region. In the belt drive area, a belt drive is arranged. The directional control valve is arranged in the valve region. The valve area is supplied with a hydraulic medium. The belt drive portion and the valve portion are separated by a box-like wall portion. The camshaft adjuster has an actuator for actuating the directional control valve, wherein the actuator is arranged outside the valve region. The directional control valve can be actuated from outside the valve area. The sealing device is arranged on the wall section separating the belt drive region and the valve region. The sealing means serves to separate the belt drive portion and the valve portion to prevent undesirable passage of hydraulic fluid from the valve portion to the belt drive portion. The sealing device has a ring-like shape with an outer edge and an inner edge. The first attachment portion is disposed on the outer edge. The second attachment portion is disposed on the inner edge. The membrane section is elastic and has an elastomeric plastic, which is also oil-resistant.

Disclosure of the invention

An object of the invention is to provide an electromagnetic actuator, in particular for actuating a hydraulic valve of a camshaft adjuster, which is simple and inexpensive to manufacture in a compact design, and has a high durability.

Another object of the invention is to provide a camshaft adjuster with such an electromagnetic actuator, which is simple and inexpensive to manufacture in a compact design, and has a high durability.

The above objects are achieved 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.

An electromagnetic actuator with a central axis is proposed, in particular for actuating a hydraulic valve of a camshaft adjuster, which comprises an electrical coil arranged around the center axis, and an armature with an actuating pin arranged in the axial direction. The armature is rotatable relative to the coil about the axis and when energized, the coil depending on the current direction along the axis up or down slidably disposed. In this case, the actuating pin is designed to operate according to a piston of a hydraulic valve of a camshaft adjuster.

An electromagnetic actuator, which is used to actuate a piston of a hydraulic valve of a camshaft adjuster, is usually subject to the requirement that the actuator is installed fixed to the engine and thereby has to transmit the actuating force to a rotating piston, for example a cylindrical roller. Typical solutions provide that the contact between the actuating pin of the actuator and the piston takes place via a ball, which undergoes lubrication with the hydraulic medium with which the hydraulic valve is also operated. Advantageously, the actuator according to the invention run dry, without lubricant, and the hydraulic valve against the actuator and surrounding units are operated sealed. Such an operating condition meets new requirements for the contact between the actuator and the piston, since a conventional ball For example, as a contact wears quickly without lubrication and the loads can not withstand. The occurring friction between ball, actuating pin of the actuator and the cylindrical roller is usually so large that the ball flattened depending on the material pairing after a short life or completely rubbed off. This is avoided by the actuator according to the invention.

Advantageously, the coil may be formed concentrically around the central axis. Likewise, the armature may be formed concentrically around the central axis. Likewise, the actuating pin can be arranged concentrically to the central axis. The armature can be arranged parallel to an end face of the coil.

In an advantageous embodiment of the actuator according to the invention, the armature can be represented by the actuating pin of the actuator by a disc pin. The disk pin is advantageously designed as a permanent magnet. The pin rotates with the hydraulic valve and the camshaft. The actuator transmits the force within the actuator to the disk pin by building up a magnetic field. The coil of the actuator is firmly connected to the internal combustion engine and does not rotate. Since there is no tactile connection between the coil of the actuator and the disk pin, no wear occurs here. The plate pin can rotate so freely. When energizing the coil, the armature is repelled with a corresponding orientation of the permanent magnetization of the armature and thereby presses on the piston of the hydraulic valve to cause a desired switching action of the hydraulic valve.

The effect of the magnetic field generating coil can be enhanced by integration of an iron core. The iron core concentrates the magnetic field lines of the coil, so that the magnetic force can be favorably focused on the armature and thereby strengthened.

In another embodiment, the spool annularly comprises the disc pin so that the actuating pin is encompassed by the spool and the spool is disposed between the armature and the hydraulic valve. The armature is attracted in this case by the coil with appropriate alignment of the permanent magnetization of the armature. As a result, a higher force level can be exerted with the magnetic field.

According to a further embodiment, the plate of the plate pin may consist of a hollow cylinder part, which is arranged in the interior of the coil of the actuator. Such an arrangement is also favorable in order to exert a high level of force on the armature. Another advantage is that in such an arrangement, the rotating armature can be covered by the coil.

Significant advantages of the invention are on the one hand the durability of the actuator and its counterpart, the piston of the hydraulic valve, since the frictional contact between the actuating pin and piston is avoided. A possible wear of the plate pin thus plays no role in the operation of the actuator. The actuator has a simple structure consisting of a coil and the corresponding armature with actuating pin, which can not be arranged in a housing, but separated from each other. The component costs can be kept relatively low, since the required components are easy to manufacture, which represents a further advantage of the embodiments according to the invention. The assembly of the actuator itself is simple, the attachment to an internal combustion engine of the coil part is also easy to do and the armature with actuating pin can be arranged on the hydraulic valve, or the camshaft adjuster.

In this way, safe operations of a central screw as a hydraulic valve of a camshaft adjuster is possible. Dirt and moisture do not have access to the hydraulic valve. The coil part of the actuator can also be encapsulated and thus made tight, so that no adverse effects are to be expected from adverse environmental conditions here.

According to an advantageous embodiment of the actuating pin may be arranged on a side remote from the coil side of the armature. The armature is designed as a permanent magnet. The actuator transmits the force within the actuator to the armature by establishing a magnetic field. The coil of the actuator is firmly connected to the internal combustion engine and does not rotate. Since there is no tactile connection between the coil of the actuator and the armature, no wear occurs here. The anchor can rotate freely. When energizing the coil, the armature is repelled with a corresponding orientation of the permanent magnetization of the armature. The actuating pin located on the armature thereby presses on the piston of the hydraulic valve to effect a desired switching action of the hydraulic valve.

According to an advantageous embodiment of the actuating pin may be disposed on a side facing the coil of the armature and passed through an inner region of the coil. In this arrangement, the coil comprises an annular ring the actuating pin. The coil is arranged between armature and hydraulic valve. The armature is attracted in this case by the coil with appropriate alignment of the permanent magnetization of the armature. As a result, a higher force level can be exerted with the magnetic field.

According to an advantageous embodiment, the armature may have on an outer circumference a hollow cylinder-shaped ring, which is arranged rotatably in the inner region of the coil about the axis. Such an arrangement is also favorable in order to exert a high level of force on the armature. Another advantage is that in such an arrangement, the rotating armature can be covered by the coil.

According to an advantageous embodiment of the armature and / or the actuating pin may be formed of a magnetic, in particular hard magnetic material. By choosing a hard magnetic material, both armature and actuating pin can be magnetized so that they represent a permanent magnet and thus can be attracted or repelled by a magnetic field generated by energizing the coil, depending on the orientation of the magnetization of the permanent magnet. Thus, armature and / or actuating pin at least partially consist of a commonly used hard magnetic material such as neodymium-iron-boron. It is conceivable that in an anchor and / or actuating pin, which may consist of a different material, for example, plastic or ceramic, a core of a hard magnetic material is embedded.

According to an advantageous embodiment of the ring may be formed of a magnetic, in particular hard magnetic material. By choosing a hard magnetic material, the hollow cylinder-shaped ring can be magnetized, so that it represents a permanent magnet and can be attracted or repelled by a magnetic field generated by energizing the coil, depending on the orientation of the magnetization of the permanent magnet. Thus, the ring may at least partially consist of a commonly used hard magnetic material such as neodymium-iron-boron. It is conceivable that a core made of a hard magnetic material is embedded in a ring, which may be made of a different material, for example, plastic or ceramic.

The invention relates in another aspect to a camshaft adjuster of an internal combustion engine having an electromagnetic actuator, wherein the camshaft adjuster comprises a hydraulically actuable actuator gear in a housing, and a hydraulic valve, which is arranged centrally in the interior of the actuator gear in the housing, which controls an adjustment of the actuator gear , An actuating pin arranged on an armature of the actuator in a central axis is connected to a piston of the hydraulic valve that can be displaced in a longitudinal axis. When energized with the actuating pin, the actuator actuates the piston of the hydraulic valve. In the actuator according to the invention, the armature with the actuating pin of the actuator is represented by a disc pin. The disk pin is designed as a permanent magnet. The pin rotates with the hydraulic valve and the camshaft. The actuator transmits the force within the actuator to the disk pin by building up a magnetic field. The coil of the actuator is firmly connected to the internal combustion engine and does not rotate. Since there is no tactile connection between the coil of the actuator and the disk pin, no wear occurs here. The plate pin can rotate so freely. When energizing the coil, the armature is repelled with a corresponding orientation of the permanent magnetization of the armature and thereby presses on the piston of the hydraulic valve to cause a desired switching action of the hydraulic valve and thus an adjustment of the camshaft adjuster.

According to an advantageous embodiment, a membrane can seal an inner region of the camshaft adjuster in a fluid-tight manner. In this case, the actuating pin is guided fluid-tightly through the membrane. Through the membrane, the actual valve region of the camshaft adjuster is fluid-tightly separated from a belt drive region, via which the drive of the camshaft adjuster is effected by a crankshaft. In this way, the camshaft adjuster can be operated so that no hydraulic medium leaks and so disturbing leaks occur or the engine compartment is polluted by escaping hydraulic fluid. Straight timing belts for driving the camshaft adjuster or similar plastic components could be degraded by leaked hydraulic medium, so that their service life would be significantly impaired. Their function could also be disturbed by the increased lubricity of the hydraulic medium.

According to an advantageous embodiment, the armature of the actuator can be arranged to be rotatable together with the hydraulic valve about the longitudinal axis. This prevents frictional losses and degradation of the materials due to friction. This is of particular importance when the operation is provided without lubrication of the contact point actuator hydraulic valve.

According to an advantageous embodiment, a coil of the actuator may be connected to a motor housing of the internal combustion engine. The motor-fixed arrangement of the coil part of the actuator represents a particularly safe and convenient form of mounting on the internal combustion engine. Contacting problems are thereby avoided. An exchange in case of failure is favored, since the coil is easily accessible and In addition, not the entire actuator must be replaced.

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 schematic actuator according to an embodiment of the invention, wherein the armature and actuating pin are arranged on one side of the coil;

2 a section through a schematic actuator according to another embodiment of the invention, wherein the actuating pin is disposed inside the coil;

3 a section through a schematic actuator according to another embodiment of the invention, in which a hollow cylindrical ring is disposed on an outer periphery of the armature;

4 a section through a camshaft adjuster according to an embodiment of the invention with an actuator according to the embodiment of 1 ;

5 a section through a camshaft adjuster according to an embodiment of the invention with an actuator according to the embodiment of 2 ; and

6 a section through a camshaft adjuster according to an embodiment of the invention with an actuator according to the embodiment of 3 ,

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 schematic actuator 10 according to an embodiment of the invention, wherein the armature 14 and actuating pin 16 on one side of the coil 12 are arranged. The electromagnetic actuator 10 in particular for actuating a hydraulic valve 50 a camshaft adjuster 100 like in the 4 to 6 shown, has a central axis L1, and comprises a coil formed concentrically around the central axis L1 12 , and an anchor formed concentric with the central axis L1 14 with an actuating pin arranged concentrically to the central axis L1 16 , The anchor 14 is parallel to a front side 18 . 19 the coil 12 spaced apart. The anchor 14 is relative to the coil 12 rotatable about the axis L1 and slidably disposed in the axis L1. This is the anchor 14 when energizing the coil 12 depending on the current direction of the coil 12 attracted or repelled. The actuating pin 16 is designed, intended a piston 52 a hydraulic valve 50 a camshaft adjuster 100 to press. The actuating pin 16 is at the in 1 illustrated embodiment on one of the coil 12 opposite side of the anchor 14 arranged. The anchor 14 and / or the actuating pin 16 is made of a hard magnetic material, so that anchor 14 and / or actuating pin 16 can be magnetized and attracted or repelled as a permanent magnet of the magnetic field generated during energization of the coil depending on Bestromungsrichtung the coil. As the actuating pin 16 a piston 52 a hydraulic valve 50 is to operate, is useful if in the in 1 illustrated embodiment of the anchor 14 from the coil 12 is repelled and so the actuating pin 16 is moved in the central axis L1 and a piston 52 can operate.

The sink 12 is in an actuator housing 26 embedded with which the actuator 10 also suitable for the internal combustion engine can be mounted.

In 2 is a section through a schematic actuator 10 illustrated according to a further embodiment of the invention, wherein the actuating pin 16 inside the coil 12 is arranged. The actuating pin 16 is doing on one of the coil 12 facing side of the anchor 14 arranged and through an interior area 20 the coil 12 passed. As the actuating pin 16 a piston 52 a hydraulic valve 50 it is expedient, if at the in 2 illustrated embodiment of the anchor 14 from the coil 12 is attracted and so the actuating pin 16 is moved in the central axis L1 and a piston 52 can operate.

Alternatively to this shows 3 a section through a schematic actuator 10 according to another embodiment of the invention, wherein a hollow cylindrical ring 24 on an outer circumference 22 of the anchor 14 is arranged. The anchor 14 points to an outer circumference 22 a hollow cylindrical ring 24 on which in the interior area 20 the coil 12 rotatable about the axis L1 is arranged. The ring 24 is made of a hard magnetic material, so that the ring 24 can be magnetized and attracted or repelled as a permanent magnet of the magnetic field generated during energization of the coil depending on Bestromungsrichtung the coil. As the actuating pin 16 a piston 52 a hydraulic valve 50 it is expedient, if at the in 3 illustrated embodiment of the ring 24 from the coil 12 is repelled and so the actuating pin 16 is moved in the central axis L1 and a piston 52 can operate.

4 shows a section through a camshaft adjuster 100 according to an embodiment of the invention with an actuator 10 according to the embodiment 1 , The camshaft adjuster 100 an internal combustion engine with an electromagnetic actuator 10 includes a hydraulically actuated actuator gear 54 in a housing 56 , as well as a hydraulic valve 50 , which is centrally located inside the gearbox 54 in the case 56 is arranged, and which an adjustment of the actuator gear 54 controls. One is at an anchor 14 of the actuator 10 concentric with a central axis L1 arranged actuating pin 16 with a displaceable in a longitudinal axis L2 piston 52 of the hydraulic valve 50 connected. The actuator 10 operated when energized with the actuating pin 16 the piston 52 , A membrane 58 seals an interior area 60 of the camshaft adjuster fluid-tight. Here is the actuating pin 16 fluid-tight through the membrane 58 guided. In this way, the camshaft adjuster 100 be operated so that no hydraulic fluid leaks and so disturbing leaks occur or the engine compartment is polluted by escaping hydraulic fluid. Straight toothed belt for driving the camshaft adjuster 100 or similar plastic components could be degraded by leaked hydraulic medium, so that their life would be significantly impaired. Their function could also be disturbed by the increased lubricity of the hydraulic medium.

The anchor 14 of the actuator 10 is with the hydraulic valve 50 together rotatably arranged about the longitudinal axis L2. The hydraulic valve 50 is as a central screw 104 of the camshaft adjuster 100 executed. The central screw 104 in turn is in the camshaft 102 continued. Both central screw 104 as well as camshaft 102 are with a rotor of the camshaft adjuster 100 connected and rotate in sync with this.

The sink 12 of the actuator 10 is connected to a motor housing of the internal combustion engine, but in 4 not shown. The coil part of the actuator 10 is therefore mechanically decoupled from the anchor 14 , Because no tactile connection between the coil 12 of the actuator 10 and the anchor 14 exists, no wear occurs here. The anchor 14 can rotate so freely. When energizing the coil 12 becomes the anchor 14 with appropriate orientation of the permanent magnetization of the armature 14 repelled and thereby presses on the piston 52 of the hydraulic valve 50 to a desired switching action of the hydraulic valve 50 and thus an adjustment of the camshaft adjuster 100 to effect.

5 alternatively shows a section through a camshaft adjuster 100 according to an embodiment of the invention with an actuator 10 according to the embodiment 2 , The actuating pin 16 is doing on one of the coil 12 facing side of the anchor 14 arranged and through the interior 20 the coil 12 passed. As the actuating pin 16 the piston 52 of the hydraulic valve 50 it is expedient, if at the in 5 illustrated embodiment of the anchor 14 from the coil 12 is attracted and so the actuating pin 16 is moved in the central axis L1 and the piston 52 can operate.

In 6 is another alternative, a section through a camshaft adjuster 100 according to an embodiment of the invention with an actuator 10 according to the embodiment 3 shown. The anchor 14 points to an outer circumference 22 a hollow cylindrical ring 24 on which in the interior area 20 the coil 12 is arranged rotatably about the axis L1. The ring 24 is made of a hard magnetic material, so that the ring 24 can be magnetized and attracted or repelled as a permanent magnet of the magnetic field generated during energization of the coil depending on Bestromungsrichtung the coil. As the actuating pin 16 the piston 52 of the hydraulic valve 50 it is expedient, if at the in 6 illustrated embodiment of the ring 24 from the coil 12 is repelled and so the actuating pin 16 is moved in the central axis L1 and the piston 52 can operate.

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 102010060181 B4 [0002]
• DE 102013101737 A1 [0003]

Claims (10)

Electromagnetic actuator ( 10 ) with a central axis (L1), in particular for actuating a hydraulic valve ( 50 ) of a camshaft adjuster ( 100 ), comprising - an electrical coil arranged around the central axis (L1) ( 12 ), - an anchor ( 14 ) with an actuating pin arranged in the axial direction ( 16 ), the anchor ( 14 ) relative to the coil ( 12 ) rotatable about the axis (L1) and when energizing the coil ( 12 ) is displaceable up or down along the axis (L1) depending on the current direction. Electromagnetic actuator according to claim 1, wherein the actuating pin ( 16 ) on one of the coil ( 12 ) facing away from the armature ( 14 ) is arranged. Electromagnetic actuator according to claim 1, wherein the actuating pin ( 16 ) on one of the coil ( 12 ) facing side of the anchor ( 14 ) and by an interior area ( 20 ) of the coil ( 12 ) is passed. Electromagnetic actuator according to claim 1, wherein the armature ( 14 ) on an outer circumference ( 22 ) a hollow cylindrical ring ( 24 ), which in the interior ( 20 ) of the coil ( 12 ) is rotatably disposed about the axis (L1). Electromagnetic actuator according to one of claims 1 to 3, wherein the armature ( 14 ) and / or the actuating pin ( 16 ) is formed of a magnetic, in particular hard magnetic, material. Electromagnetic actuator according to claim 4, wherein the ring ( 24 ) is formed of a magnetic, in particular hard magnetic material. Camshaft adjuster ( 100 ) an internal combustion engine with an electromagnetic actuator ( 10 ) according to one of the preceding claims, comprising - a hydraulically actuable position gearing ( 54 ) in a housing ( 56 ), - a hydraulic valve ( 50 ), which centrally in the interior of the gearbox ( 54 ) in the housing ( 56 ) is arranged, which an adjustment range of the actuator gear ( 54 ), one at an anchor ( 14 ) of the actuator ( 10 ) in a central axis (L1) arranged actuating pin ( 16 ) with a in a longitudinal axis (L2) displaceable piston ( 52 ) of the hydraulic valve ( 50 ) and wherein the actuator ( 10 ) when energized with the actuating pin ( 16 ) the piston ( 52 ). Camshaft adjuster according to claim 7, wherein a diaphragm ( 58 ) an interior area ( 60 ) of the camshaft adjuster fluid-tight seals and wherein the actuating pin ( 16 ) fluid-tight through the membrane ( 58 ) is guided. Camshaft adjuster according to claim 7 or 8, wherein the armature ( 14 ) of the actuator ( 10 ) with the hydraulic valve ( 50 ) is arranged rotatably together about the longitudinal axis (L2). Camshaft adjuster according to one of claims 7 to 9, wherein a coil ( 12 ) of the actuator ( 10 ) is connected to a motor housing of the internal combustion engine.

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