WO2014146800A1

WO2014146800A1 - Electromagnetic actuating device

Info

Publication number: WO2014146800A1
Application number: PCT/EP2014/050354
Authority: WO
Inventors: Guenther Hohl
Original assignee: Robert Bosch Gmbh
Priority date: 2013-03-19
Filing date: 2014-01-10
Publication date: 2014-09-25
Also published as: DE102013204764A1

Abstract

The invention relates to an electromagnetic actuating device (20) having a housing (2), a magnet element (9), a spring element (5) and an actuating element (8), said actuating element (8) being designed to adopt a first position, in which it protrudes from the housing (2) by a first length, and at least one second position, in which it protrudes from the housing (2) by a second length which differs from the first. The magnet element (9) is designed to hold the actuating element (8) in one of the first or second positions and the spring element (5) is designed to hold the actuating element (8) in the other of the first and second positions. The actuating device is characterised in that the magnet element (9) is positioned in the housing (2) in an immobile manner in relation to said housing (2).

Description

Electromagnetic actuator

The present invention relates to engine technology in vehicles. More particularly, the present invention relates to an electromagnetic actuator, a camshaft assembly, and an engine for a vehicle, particularly an automobile, and a vehicle.

State of the art

Camshafts are used in engine technology and are part of the valve train there. They are used to control the intake and exhaust valves of a

Open engine or individual piston according to design-defined timing and close. A camshaft is a machine element on which at least one rounded projection, the so-called cam, is arranged. The shaft rotates about its own axis, with the longitudinal movement realized by the cam to open and

Closing the valves is used.

A specific shape and relative arrangement of several cams one

Camshaft thereby determine the characteristics of a thus controlled motor element.

Meanwhile, camshafts are known which provide a change in engine characteristics by a relative displacement of a camshaft, so that depending on the required engine characteristics

different cam assembly is present at the valves and controls them.

Such a realization of different camshaft profiles, thus a variable valve control, usually uses a suitable electromagnetic actuator, which is used to activate or deactivate a desired or specific camshaft arrangement. conventional

Electromagnetic actuators are known, for example, from DE 102 40 774 B4 and EP 1 421 591 B1. The ones described herein

However, electromagnetic actuators are difficult to use Working permanent magnets, which must be chambered for use in the working space of a valve. As a result, there is a risk that the permanent magnet accumulates abrasion and dirt particles, which can lead to a malfunction or functional impairment of the electromagnetic actuator. Due to the engine facing

Design of the permanent magnets these are increasingly exposed to the heat output of the engine, with maximum permissible temperatures, in particular for permanent magnet material due to the material is limited. Thus, the orientation of elemental magnets are lost at high temperatures.

Depending on the design of the electromagnetic actuator, however, this is due to their design and arrangement in the field of the engine of a vehicle exposed to mechanical, thermal and pollution loads that may affect the long-term operation of an electromagnetic actuator.

Disclosure of the invention

One aspect of the present invention may thus be seen to provide an improved electromagnetic actuator, in particular such an electromagnetic actuator which, due to its structural design, has a reduced lifetime degradation due to mechanical, thermal and contamination loads. Accordingly, an electromagnetic actuator, a

Camshaft assembly, an engine and a vehicle, in particular an automobile according to the independent claims displayed. Preferred embodiments will be apparent from the dependent claims. The improvement according to the invention is realized by the use of a

Permanent magnet in conjunction with a solenoid coil as drive. However, the permanent magnet is outside the working space of the valve or on the control pin or the actuator opposite side of the electromagnetic actuator and thus on the side facing away from the motor of the housing of the magnetic actuator. This results in at least reduced particle accumulation and a lower

Temperature load of the material. In addition, according to the invention, the magnetic element is not moved, but is static or immobile in the housing arranged and is therefore not mechanically stressed. As a result, the risk of edge injuries, outbreaks and the like is reduced or completely avoided. Basic requirements for an electromagnetic actuator is doing a

Extend control pin or an actuator several millimeters stable, the provision of the control pin via the camshaft itself can be done. The control pin or the adjusting element is thus to be held in the retracted position or the first position and an extended position or a second position respectively stable and in particular without external power supply.

The inventive electromagnetic actuating device thus has in principle at least two positions, a first position and a second position, of its control element, which is outside the electromagnetic

Distinguish actuator to the effect that the actuator protrudes with different lengths from the housing and allows this actuating end an adjustment process. It can do that

Actuating element further protrude out of the housing, especially in the second position than in the first position. The actuator may then be e.g. in a suitable guide on the camshaft of an engine a lateral

Allow displacement of a Nockenwellenkulisse on a rotation axis.

Through this shift, different camshaft profiles can be overlapped with the valves and by the different

Camshaft profiles realize a modified or variable valve control. Depending on the structural design may be sufficient here a few millimeters to centimeters difference in length of the control element between the two positions for the realization of a valve control. According to the invention, the electromagnetic adjusting device is designed such that the two

Positions, when taken each, are held without further energy supply, in particular without electrical energy supply. By a suitable force acting from the outside on the actuator, for example, this pulls or pushes in the axial direction, the actuator can also be transferred from outside from one position to the other position. The electromagnetic actuator according to the present invention comprises, on the one hand, a magnetic element capable of holding the actuator in one of the first and second positions while providing a spring element which moves the actuator from the position held by the magnetic element toward the other position want to push or transfer.

In this case, the spring force or the magnetic force of the magnetic element in each case the position in which the adjusting element is held by spring element or magnetic element, greater than the adjusting force of the respective other element. Based on the magnetic element and the arrangement of the actuators on

Magnetic element outweighs the attractive magnetic force of the

Magnetic element on the actuator, the repulsive spring force of

Spring element, so that the actuating element is held on the magnetic element and remains in this position. In the other position, away from

Magnetic element, the force applied by the spring element of the force of the attractive effect of the magnetic element, e.g. due to the increased distance of actuator and magnetic element and the thus reduced effect of the magnetic force on the actuator. An inventive switching the positions, in particular of the

Position in which the actuator is held by the magnetic element, to the position in which the actuator is held by the spring element can be achieved by an additional force acting on the actuator, at least temporarily or temporarily, so that the Spring force supporting additional force acts on the actuating element, wherein the sum of the additionally acting force and the force of the spring element exceed the attractive force of the magnetic element. Due to the now higher sum of the two forces relative to the magnetic force, the actuator moves from the position in which it is held by the magnetic element to the position in which it is held by the spring element. After elimination of the additional external force outweighs in the position remote from the magnetic element still the force of the spring element against the attractive force of the magnetic element, so that the actuator is held by the spring force against the (lower) magnetic force in this position.

Such an additional or external force can on the one hand be effected by a pulling or pushing force acting on the adjusting element (for example from the outside) or by a further element, for example a coil element in FIG Inside of the housing, can be provided, which applies to the spring force adding (second) magnetic force on the actuator, the sum of the spring force and the additional second magnetic force through the coil element exceeds the (first) magnetic force of the magnetic element and thus the actuator of the first Position in the second position is able to bring.

After the offset of the positions in the position in which the spring element holds the actuator in the position, the additional (magnetic) force can be omitted, in the case of a coil element whose current can be suspended again. A return of the actuating element from the second position to the first position can be achieved by simply pushing or displacing the actuating element in the direction of the housing of the electromagnetic

Actuator, e.g. by an externally acting force in the axial direction.

If the actuator is pressed far enough into the housing of the electromagnetic actuator, then in turn outweighs the magnetic force of the magnetic element, and the actuator is held by the magnetic element alone in the first position.

Embodiments of the invention are illustrated in the drawings and explained in more detail in the following description.

Show it

Figure 1 shows an exemplary embodiment of an electromagnetic

Adjusting device in a first position according to the present invention; and

Figure 2 shows an exemplary embodiment of an electromagnetic

Actuator in a second position according to the present invention.

Still referring to FIG. 1, an exemplary embodiment of the electromagnetic actuator is shown in a first position in accordance with the present invention. The electromagnetic actuator 20 has an actuator 8 and a control pin, which can be acted upon by a spring element 5 with a force F _F , which is suitable to press the actuator 8 to the outside of the housing 2 of the electromagnetic actuator 20 and this thus of View outside extend .. This allows the actuator 8 in the

Extend control geometry of a camshaft (not shown) and thereby assumes a front position or a second position.

Control element 8 is fixedly connected to an armature disk 4, which is arranged such that a magnetic element 9, for example a permanent magnet, a

Magnetic force F _m can apply to the armature disk 4 and thus to the actuator 8 connected thereto. In the first position or the rear position of the armature disk 4 and thus the adjusting element 8 is pulled in the direction of the magnetic element 9 in the currentless position of the coil element 1, which, for example, using a closure cover 10 of the

Anchor plate 4 is separated. The force F _{m of} the magnetic element 9 predominates in this position, the first position, and is thus in particular greater than the force F _{F of} the spring element 5, which may apply this in the first position. As a result, the adjusting element 8 is retracted stable and held on the first or rear position.

If the control element 8 is to extend into the control geometry of a camshaft, the coil element 1 is briefly energized. Figure 2 shows the from

Actuator 8 occupied second position, in the anchor element 4 by way of example connects to disk element 6 or rests.

The magnetic flux runs as an example over the housing shell 2, a slotted magnet sleeve 3 and armature 4, which closes the air gap to an inner pole 7 and a fixedly connected disc 6. With the additional force F _em des

Electromagnet is applied a positive force to the spring force F _F adding additional force, causing the armature 4 releases from the rear or first position. After a certain partial stroke, the spring force F _{F of} the spring element 5 alone already outweighs the force F _{m of} the magnetic element 9 due to the now resulting larger air gap between the magnetic element 9 and armature disk 4. Already now could / coil element 1 of the electromagnet is turned off

(Be) or only when the armature disk 4 (with its other / second side) by way of example to disk 6. In this second position, the position away from the magnetic element 9, the spring force F _{F of} the spring element 5 alone outweighs the attraction force F _{m of} the magnetic element, and the actuator 8 is stably maintained in the rear or second position, without any further energy supply for the electromagnetic actuator 20 is required.

However, by an external force F _ext can be control element 8 against the

Spring force F _{F back} in the direction of the magnetic element 9 and thus in its first position. This external force can be applied for example by the camshaft and thus reset the actuator 8.

Terminals or Spulenkontaktlerung 11 for the coil element 1 can be passed through a slot in the magnet sleeve 4 and a recess in the closure pot 10 to the outside, for example in the direction of the magnetic element 9 and thus to the motor side facing away. Magnetic element 9 may in particular be fixedly connected, for example glued, to the closure lid 10, whereby it is protected against mechanical damage and soiling, in particular by further use of a cover 12, for example by a potting compound.

Claims

An electromagnetic actuator (20) comprising

a housing (2);

a magnetic element (9);

a spring element (5); and

an actuator (8);

wherein the actuator (8) is arranged to assume a first position in which it protrudes a first length out of the housing (2) and at least a second position in which there is a second, different from the first length, from the housing (2 ) stands out;

wherein the magnetic element (9) is arranged to hold the actuator (8) in one of the first and second positions;

wherein the spring element (5) is arranged to hold the actuator (8) in the other of the first and second positions;

characterized in that

the magnetic element (9) is arranged in the housing (2) such that it is immovable with respect to the housing (2).

Actuator according to claim 1, further comprising

a coil element (1),

wherein the coil element (1) is arranged to move the adjusting element (8) between the first and the second position, in particular the

Actuator (8) from the position in which it is held by the magnetic element (9) in the position in which it is held by the spring element (5) to move.

Adjusting device according to claim 1 or 2,

wherein the magnetic element (9) exerts a force (F _m ) on the actuator (8) and holds it in position against the force (F _F ) applied by the spring element (5); and or

wherein the spring element (5) exerts a force (F _F ) on the adjusting element (8) and holds it in position against the force (F _m ) applied by the magnetic element (9). Adjusting device according to one of claims 1 to 3,

wherein the adjusting element (8) can be displaced from the position held by the spring element (5) by a force (F _ext ) acting externally on the adjusting element (8) into the position held by the magnetic element (9).

Adjusting device according to one of claims 1 to 4,

wherein the magnetic element (9) in the housing (2) on the one outlet opening (13) of the adjusting element (8) from the housing (2) opposite side of the housing (2) is arranged.

Adjusting device according to one of claims 1 to 5,

wherein by, in particular short-term, energization of the coil element (1), the adjusting element (8) from the position in which it from the

Magnetic element (9) is held in the position in which it is held by the spring element (5) is displaceable.

Camshaft arrangement for a vehicle, in particular automobile, comprising an adjusting device (8) according to one of claims 1 to 6.

Engine for a vehicle, in particular automobile, having a

Camshaft arrangement according to the preceding claim and / or an adjusting device (8) according to one of claims 1 to 6.

Vehicle, in particular automobile, having an engine according to the preceding claim, a camshaft arrangement according to claim 7 and / or an adjusting device (8) according to one of claims 1 to 6