EP3583615A1

EP3583615A1 - Electromagnetic linear actuator

Info

Publication number: EP3583615A1
Application number: EP18708591.5A
Authority: EP
Inventors: Franci Lahajnar
Original assignee: Kolektor Group doo
Current assignee: Kolektor Group doo
Priority date: 2017-02-15
Filing date: 2018-02-06
Publication date: 2019-12-25
Anticipated expiration: 2038-02-06
Also published as: KR102348537B1; DE102017103090B4; CN110326065A; WO2018149694A1; CN110326065B; US20190362875A1; KR20190113834A; EP3583615B1; DE102017103090A1; JP7113033B2; JP2020508034A; US11094442B2

Abstract

An electromagnetic linear actuator comprises a housing (1) having a casing section (6) and an end piece (5), a coil arrangement (2) which is arranged therein and has two coils (19, 20) which extend about a common axis (A), are wound in opposite directions and are offset axially with respect to one another, and an armature arrangement (3) which is mounted so as to be displaceable in the housing (1), along the axis (A) between two end positions, and has a shaft (8), which passes through the end piece (5), and a permanent magnet arrangement (9) which is arranged at the end of said shaft (8) and has an axially magnetized permanent magnet (10) and two disc-shaped flux conducting pieces (11) which are arranged on the front side thereof. The first coil (19) which faces away from the free end of the shaft (8) has, at its end facing away from the free end of the shaft (8), a region (27) with a reduced internal diameter. A core (28) made of a magnetically active material is held in said coil (19). In each of the two end positions of the armature arrangement, at least 50% of the axial length of the permanent magnet arrangement is overlapped by one of the two coils (19, 20).

Description

Electromagnetic linear actuator

The present invention relates to a

electromagnetic linear actuator. In particular, the present invention relates to an electromagnetic

A linear actuator comprising a housing having a skirt portion and an end portion, a coil assembly disposed in the housing having two around one

extending along the axis, in opposite directions

wound, axially offset coils and one in the housing along the axis between two

Armature arrangement displaceably mounted at the end positions, with a shaft passing through the end piece and an axially magnetized permanent magnet arranged thereon, and two end faces on the latter

arranged disc-shaped flux guides having permanent magnet assembly, wherein in each of the two

End positions of the armature assembly is at least 50% of the axial length of the permanent magnet assembly of one of the two coils is overlapped.

Electromagnetic linear actuators are in

various versions known and in use. Their respective design and individual design depends on the respective application. they hang

for example, starting from the space available in the application in question, the required adjustment (or switching path), which covers the shaft between the two end positions, and the required force, the shaft must be able to exert on a component to be actuated. Also the achievable

Switching dynamics, ie the time that the shaft for the movement from one to the other end position needed is a significant one for many applications

Size. It should be remembered that in part between the different aspects and performance characteristics

Dependencies exist. So is generally provided by the shaft adjusting (or.

Shift force) in a relationship to the size such that larger linear actuators can provide greater displacement. However, this suffers - as a result of the larger masses to be moved - typically the achievable switching dynamics. Furthermore, switching dynamics and switching force are so far in connection with each other, as for accelerating the

Anchor assembly required force in this

Movement phase of the armature assembly reduces effective switching power.

The initially specified design corresponding

Electromagnetic linear actuators may, as applies, for example, to the linear actuators according to JP 57- 198612 A and EP 1275886 A2, by the

Possibility of two stable switching states. They can therefore be designed as so-called bistable actuators, in which the shaft - due to an interaction of the permanent magnet assembly with the housing - each of its two end positions without

Applying (energization) of the coil assembly can comply, but partially in a corresponding manner for similar designs with a different

Execution of the permanent magnet arrangement and / or their coordination with the coil arrangement applies (see.

for example US 3504315 A, US 3503022 A, US 4490815 A, CN 101908420 A, US 3202886 A and DE 2423722 A). The aspects already discussed above are included Such bistable electromagnetic actuators as a further aspect still in the stable

Switching states on the armature assembly force (holding force) added; because a higher holding force typically has a noticeable effect in terms of a

reduced initial acceleration of the

Anchor arrangement and thus affects the

Switching dynamics.

US 4071042 A discloses a generic

electromagnetic linear actuator, which, as indicated in the preamble of claim 1, in addition to the features outlined above characterized in that the permanent magnet assembly is disposed on the end side of the shaft. However, this electromagnetic linear actuator is not designed as a bistable actuator, but rather designed for the operation of a hydraulic servo valve, for which purpose a for

Energization of the coil assembly is desired proportional deflection of the armature assembly from a neutral center position out.

US 2004/0100345 A1 discloses an electromagnetic designed for use on a transmission

Linear actuator. This has two arranged in a shell-shaped housing coils, between which there is a central flux guide. At the end a fixed flux guide is inserted into the housing, through which the shaft of a

Anchor arrangement extends, on which end a first movable flux guide is arranged. Between the fixed flux guide and the first movable flux guide is a second movable Flux guide, which is movable both relative to the housing and relative to the armature assembly. Depending on the energization of a coil, the other coil or both coils, the armature assembly occupies one of three defined positions.

The present invention aims to provide a

electromagnetic linear actuator of the beginning

specified type, which is improved by a comparison with the prior art

Performance characterizes. In this sense, especially a highly dynamic working

electromagnetic linear actuator of the beginning

specified type with a particularly high adjustment

to be provided.

According to the invention, this task is solved by a generic electromagnetic

Linear actuator which faces away from the free end of the shaft first coil at its the free end of the shaft

facing away from a region having a reduced inner diameter and in the first coil

the end of a core of a magnetically active material is added. A decisive advantage that can be achieved in the inventive design of the electromagnetic linear actuator is the hitherto unknown, as explained in detail below, the optimum course of the between the stator and the

Anchor arrangement effective electromagnetic force.

This course of the force acting on the armature assembly electromagnetic force leaves - despite a

noteworthy in the first end position of the

Anchor arrangement on this holding force - a especially high initial acceleration of the

Anchor arrangement to, over the further adjustment of the armature assembly can act on these a particularly uniformly extending electromagnetic force, which is beneficial both on the further acceleration of the armature assembly and on the provided

Switching force affects. Towards the end of the adjustment path, a significant increase in the adjustment force is again possible, which is particularly favorable in typical applications. In particular, over a large part of the adjustment particularly homogeneous course of the force exerted on the armature assembly electromagnetic force is extremely advantageous.

A first preferred development of the invention is characterized in that the core accommodated in the first coil of the coil arrangement at the end reduces the entire axial extension of the one

Inner diameter portion of the first coil overlaps. This promotes a force curve that causes a particularly high initial acceleration of the armature assembly. It is particularly advantageous if the region of the first coil having a reduced inner diameter radially overlaps the permanent magnet arrangement in the sense that the outer diameter of the

Permanent magnet arrangement is greater than that

Inner diameter of the reduced inner diameter portion of the first coil.

For the force curve is also particularly advantageous if - according to another preferred embodiment of the invention - the axial distance between the first and the second coil is not much larger than necessary in terms of winding technology. Ideally, if the first and the second coil of the

Coil arrangement - particularly preferred on one

common support sleeve of magnetically inactive material - are continuously wound, which limits existing between the first and second coil axial distance to the extent required for a damage-free 180 ° bend of the winding wire. In practice, the distance in question should at least not be more than 50% above that

technically indispensable necessary measure.

According to another preferred embodiment of

Invention is provided that between the first coil and the second coil no flux guide is arranged. Such a result would lead to an inhomogeneous force curve and to that extent in the inventive

Design of the electromagnetic linear actuator adversely affect its performance.

Yet another preferred embodiment of

Invention is characterized in that in the first end position of the armature assembly in which the

Permanent magnet assembly overlaps more than 50% of the first coil (and typically the shaft is retracted into the tail), an axial gap exists between the core and the adjacent flux guide of the permanent magnet assembly. In this way, it is possible to exert a positive influence on the breakaway force that is required so that the armature arrangement-contrary to the holding force-is moved out of the first end position. One way to do this especially

easy way to achieve, is that the shaft axially through the permanent magnet assembly passes through and protrudes from this a bit far. Thus, the armature assembly with the respective projection of the shaft abut the core and keep the adjacent Flußleitstück the permanent magnet assembly to this distance. Incidentally, the stem exists

advantageously of a magnetically inactive

Material, preferably stainless steel. This is favorable not only for the above-described function as a "stop" for the armature arrangement, but also because of the achievable in this way reduction of the magnetic inductance and the associated concentration of

magnetic field on the outside, with the

Coil assembly interacting environment of the permanent magnet assembly.

Furthermore, it is favorable for the force curve, if - according to yet another preferred embodiment of the invention - the overlap of the permanent magnet arrangement by the first coil in the first end position of

Anchor arrangement is less than the overlap of

Permanent magnet arrangement through the second coil in the second end position of the armature arrangement. So can

For example, the permanent magnet arrangement in the first end position of the armature assembly to 55% to 85% by the first coil, but in the second end position of

Anchor assembly through the second coil to be axially overlapped to a greater extent in a proportion between 65% and 100%. Particularly preferred ranges are at an axial overlap of the permanent magnet arrangement by the first coil in the first end position of the armature assembly to 65% to 75% and by the second coil in the second

End position of the armature arrangement to 75% to 90%. Yet another preferred embodiment is characterized in that the end piece of the housing is designed as an assembly and guide block. In this sense, the end piece of the housing has both such structural features (eg, a flange)

Einschraubgewinde, a mounting extension, etc.), the attachment of the linear actuator to a member having the actuated element structural structure (eg., The cylinder head of an internal combustion engine in the case of using the linear actuator for

Camshaft adjustment), as well as the guidance of the armature assembly serving structural features (eg., Running as a sliding guide for the shaft of the armature assembly bore). In particularly preferred

Design is the armature assembly exclusively guided in the assembly and guide block slidably guided.

Advantageously, furthermore, the

Permanent magnet arrangement on its outer circumference at least one extending over the axial length

Compensation channel on. This proves to be favorable in terms of switching dynamics; This is also the case for a relatively small radial gap between the air gap, which has a positive effect on the efficiency

Permanent magnet arrangement and the surrounding

Coil arrangement (outside the at least one

Compensation channels) when moving the armature assembly, the permanent magnet assembly with low resistance (through the at least one compensation channel through) are flowed around by air. In a very special way come the

advantages set forth above of the present invention

Invention for carrying when the linear actuator is designed as a double linear actuator with two parallel

to each other, juxtaposed armature assemblies and associated coil assemblies, wherein the housing has two separate shell sections and a

common tail, through which both shafts

pass through. Thus, two functionalities can be realized in a confined space, wherein the compactness benefits that the tail for both units can be magnetically effective together. The same applies to an advantageously opposite to the tail provided common end plate of the

Housing.

Preferably, the above-described double linear actuator has an enclosure with a common protective cap surrounding the two shells of the housing. The latter is particularly preferably tight with a attached to the tail flange plate or a

Flange ring connected.

In the following, the present invention will be described with reference to a preferred embodiment illustrated in the drawing

Embodiment explained. It shows

1 shows an axial section through a double as

Linear actuator running electromagnetic

Linear actuator according to the present invention, Fig. 2, the linear actuator according to Fig. 1 in a

cut perspective view and

Fig. 3 is a diagram for illustrating the course of the current flow through the coil assembly, the acting on the armature assembly resulting force and the movement of the armature assembly over time after the beginning of the energization of the coil assembly.

The illustrated in Figures 1 and 2 of the drawing, designed as a double linear actuator electromagnetic linear actuator comprises four main functional components in the form of a housing 1, two housed therein coil assemblies 2, two anchor assemblies 3 and an enclosure. 4

The housing 1 comprises an end piece 5, two cylindrical shell portions 6 and, opposite the end piece 5, a common end plate 7. These parts are made of a ferromagnetic material. For centering and positionally accurate positioning of the sheath sections 6 on the end piece 5 while producing a good magnetic flow behavior, the end piece 5 dives in each case accurately with a projection end in the respective shell portion 6 a. In the opposite end region, the two shell sections 6 each have (opposite each other) a recess through which the end plate 7 passes. In the area of those

Recesses are the two shell sections 6 in blunt contact with the end plate 7. Incidentally, the end plate 7 nestles as possible gap-free to the inner contour of the shell sections 6. In each of the two jacket sections 6, a coil arrangement 2 is arranged.

The two armature assemblies 3 each comprise a shaft 8 and an end arranged on this Permanent magnet arrangement 9 with an axially magnetized permanent magnet 10 and two frontally thereto

arranged disk-shaped Flussleitstücken 11. The - consisting of a magnetically inactive material - shaft 8 occurs thereby reduced with a range

Diameter axially dergestalt through the - accordingly axially pierced - permanent magnet assembly 9 through, that it protrudes at the opposite end face a little way from the flux guide 11 and a projection 12 forms. On the outer circumference of the respective

Permanent magnet arrangement 9 are four over the axial length extending compensation channels 13 are provided.

In each case, the shaft 8 is each of the two

Anchor assemblies 3 in the end piece 5 slidably guided along an axis A. The end piece 5 is designed for this purpose as an assembly and guide block 14. It has an axial projection 15 and has two as sliding guide for the respective shaft 8 of

Anchor assembly 3 executed holes 16. Each shaft 8 has two to the bore 16 corresponding, matched to this, spaced apart

Guide portions 17, 18, between which the shaft 8 tapers to a reduced diameter. The shafts 8 pass through the end piece 5. Above the figures 1 and 2 while the armature assembly 3 is shown in the first end position with fully retracted into the housing 1 shaft 8, whereas the bottom

Anchor assembly 3 is shown in the second end position with maximally extended from the housing 1 shaft 8.

The coil assemblies 2 each comprise two axially wound around the axis A, wound in opposite directions mutually offset coils 19, 20, namely a - the free, guided in the end piece 5 end of the shaft 8 arranged away - first coil 19 and a second coil 20. The two coils 19, 20 are on a common carrier sleeve 21 of magnetically inactive

Material added. By means of a first end plate 22, a second end plate 23 and an intermediate ring 24 is in each case the outer surface of the carrier sleeve 21 in two

Compartments for receiving the first coil 19 and the second coil 20 divided. The first end plate 22 and the intermediate ring 24 each have openings 25 for the passage of the winding wire of the two - continuously, but with reversal of the winding direction at the transition from the first coil 19 to the second coil 20 wound - on coils. Also, the end plate 7 of the housing 1 has on the implementation of the respective winding wire serving breakthroughs 26th

The first coil 19 has, in each case at its end remote from the free end of the shaft 8, a region 27 with a reduced inner diameter. For this is the

Carrier sleeve 21 executed appropriately stepped. The reduced inner diameter of the first coil 19 in the relevant region 27 is selected such that the permanent magnet arrangement 9 and the first coil 19 in that reduced internal diameter region 27 in an annular

Overlap overlap zone radially.

In the end region of the support sleeve 21 - a gap 28 of a magnetically active material is used - gap-free on the end plate 7 fitting.

This overlaps the entire axial extent of the one Reduced inner diameter portion 27 having the first coil 19. For this purpose, it is designed corresponding to the support sleeve 21 stepped. In the first

End position of the armature assembly 3 (shown in Figs. 1 and 2 above) is outstanding from the permanent magnet assembly 9 protrusion 12 of the shaft 8 to the core 28 at. In this way, the core 28 adjacent to the flux guide 11 of the permanent magnet assembly 9 to the core 28 maintains a corresponding distance, d. H. it exists between the core 28 and the adjacent one

Flux guide 11 of the permanent magnet assembly 9 an axial gap 29th

The axial extent of the permanent magnet arrangement 9 and the respective axial extension and arrangement of the first coil 19 and the second coil 20 are coordinated so that the axial overlap of the

Permanent magnet assembly 9 through the first coil 19 in the first end position of the armature assembly 3 is less than the axial overlap of the permanent magnet assembly 9 through the second coil 20 in the second end position of the armature assembly 3. Thus, the axial overlap of the permanent magnet assembly 9 through the first coil 19 in the first end position of the armature assembly 3 about 70%, whereas the axial overlap of the

Permanent magnet assembly 9 through the second coil 20 in the second end position of the armature assembly 3 is about 82%.

The housing 4 serving for the protection of external influences comprises a common protective cap 30 which surrounds the two jacket sections 6 of the housing 1 and which seals tightly with a flange ring 31 attached to the end piece 5 connected is. Protective cap 30 and flange 31 have mutually aligned bores 32 which the

Attachment of the double linear actuator to one

serve existing structure by means of appropriate screws.

The illustrated in the drawing embodiment of the linear actuator is highest from the viewpoint

Switching dynamics and maximum switching power at one

Movement of the armature assembly 3 optimized from the first to the second end position. With regard to a simple design with only minimal dimensions is omitted in this embodiment, an electromagnetically successful return of the armature assembly 3 from the second end position to the first end position. Such a return takes place at this

Embodiment by means of a separate, acting on the respective shaft 8 external

Reset device. Meanwhile, the double linear actuator shown also with respect to a

Electromagnetic feedback of the

Anchor arrangement to be modified. Could do this

In particular, the second coil 20 are axially slightly extended and at its the free end of the shaft 8 facing the end of a region having a reduced inner diameter, wherein this one

Reduced inner diameter portion having the second coil, the permanent magnet assembly 9 radially overlap and in the second coil 20 end a core sleeve of a magnetically active material

could be included. Fig. 3 illustrates the outstanding performance of a designed according to the embodiment of Figures 1 and 2, on a respective 4.75 mm amount of stroke of the armature assemblies 3 designed double linear actuator with a diameter of

Permanent magnet arrangements 9 of only 8 mm. Without

Energization of the coil assembly 2 is - by

Cooperation of the respective permanent magnet assembly 9 with the core 28 - the armature assembly 3 with a

Holding force of about 9.5 N held in its first end position. When energizing the coil assembly 2, this holding force is compensated after only 0.25 ms, and by equally rapid further increase in

Electromagnetically generated force sets in only 0.5 ms after the beginning of the energization (response time), the movement of the armature assembly 3 a. The shaft 8 lifts off the core 21, and the holding force rapidly collapses. About 1 ms after the start of the current supply, the electromagnetically generated force acting on the armature arrangement 3 has an effect

Plateau reached on average 8.5 N, which is maintained with very high uniformity almost over the entire displacement of the armature assembly 3. As a result, the armature assembly 3 performs a continuously accelerated movement. Towards its end (about 3.2 ms after the beginning of energizing the coil assembly 2 and about 1 mm before reaching the second end position) is increasingly the second end position of the armature assembly 3 associated holding force added, resulting in a strong progressive increase in Total power leads. After just 3.5 ms, the armature arrangement 3 reaches its second end position after a switching travel of 4.75 mm. During continued energization of the coil assembly, the resulting total force here is about 22 N.

Claims

claims

An electromagnetic linear actuator comprising

a housing (1) having a jacket section (6) and an end piece (5),

- One in the housing (1) arranged

Coil arrangement (2) with two around a common axis (A) around, in opposite directions wound, axially offset from each other coils (19, 20) and

- One in the housing (1) along the axis (A) between two end positions slidably mounted armature assembly (3) passing through the end piece (5) shaft (8) and arranged thereon, an axially magnetized permanent magnet (10) and two frontally arranged on this

Disc-shaped flux guides (11) having permanent magnet assembly (9), wherein

the permanent magnet arrangement (9) arranged on the end of the shaft (8) and in each of the two

End positions of the armature assembly (3) at least 50% of the axial length of the permanent magnet assembly (9) of one of the two coils (19, 20) is overlapped, characterized in that

- The first coil (19) facing away from the free end of the shaft (8) at its end facing away from the free end of the shaft (8) has a region (27) with a reduced inner diameter and - In the first coil (19) end a core (28) is received from a magnetically active material.

Linear actuator according to claim 1, characterized

characterized in that the core (28) reduces the total axial extent of the one

Inner diameter portion (27) of the first coil (19) overlaps.

Linear actuator according to claim 1 or claim 2, characterized in that the region (27) of the first coil (19) having a reduced inner diameter radially overlaps the permanent magnet arrangement (9).

Linear actuator according to one of claims 1 to 3, characterized in that the axial distance between the first and the second coil (19; 20) is not substantially greater than winding technology absolutely necessary.

Linear actuator according to one of claims 1 to 4, characterized in that between the first coil (19) and the second coil (20) no

Flow guide is arranged.

Linear actuator according to one of claims 1 to 5, characterized in that the two coils (19, 20) are received on a common carrier sleeve (21) made of magnetically inactive material.

7. Linear actuator according to one of claims 1 to 6, characterized in that in the first

End position of the armature arrangement (3), in which the

Permanent magnet assembly (9) is overlapped by more than 50% of the first coil (19), an axial gap (29) exists between the core (28) and the

adjacent flux guide (11) of

Permanent magnet arrangement (9).

8. Linear actuator according to one of claims 1 to 7, characterized in that the shaft (8) consists of a magnetically inactive material and passes axially through the permanent magnet assembly (9).

9. Linear actuator according to one of claims 1 to 8, characterized in that the overlap of the permanent magnet arrangement (9) through the first coil

(19) in the first end position of the armature assembly (3) is less than the overlap of

Permanent magnet arrangement (9) through the second coil

(20) in the second end position of the armature assembly (3).

10. Linear actuator according to one of claims 1 to 9, characterized in that the end piece (5) of the housing (1) as an assembly and guide block (14) is executed.

11. Linear actuator according to claim 10, characterized

characterized in that the armature arrangement (3)

is mounted displaceably guided exclusively in the assembly and guide block (14).

12. Linear actuator according to one of claims 1 to 11, characterized in that the

Permanent magnet arrangement (9) on its outer circumference at least one over the axial length

having extending compensation channel (13).

13. Linear actuator according to one of claims 1 to 12, characterized in that it is designed as a double linear actuator with two juxtaposed armature assemblies (3) and associated coil assemblies (2), wherein the

Housing (1) has two separate shell sections (6) and a common end piece (5) through which both

Shanks (8) pass through, has.

14. Linear actuator according to claim 13, characterized

characterized in that the housing (1) opposite the end piece (5) has a common end plate (7).

15. Linear actuator according to claim 13 or claim 14, characterized in that it comprises an enclosure (4) with a two jacket sections (6) of the housing (1) surrounding the common protective cap

(30).

16. Linear actuator according to claim 15, characterized

in that the protective cap (30) is sealed to a flange ring attached to the end piece (5)

(31) is connected.