EP2395526A1 - Electromagnetic switching device - Google Patents

Abstract

The device (11) has a moving part (15) provided with handles (19) for an operator for performing rotary actuation and sliding operation. The moving part is mounted at a housing (13) of the device, and a braking device comprises a brake element (28) i.e. rubber band, that is provided with static friction value and sliding friction value. The brake element is provided with compression stress and friction during actuation of the device between the moving part and a base part (21) or remaining components of the device. The brake element is made of elastomer such as rubber or silicone.

Description

The invention relates to an electromechanical switching device for rotary actuation or sliding operation, which has a base part and a movement part mounted thereon. The moving part has a handle for an operator. Such switching devices are also referred to as controllers.

Such a switching device is for example from the DE 8716921 U1 known. Here is a detent system is described to be able to pretend with such a switching device different locking positions along a rotational path as actuating travel during rotation operation. The problem with this is generally that the voltage applied to the handle torque is very much determined by the construction of the detent gate of the detent system. Different locking parts, which can be either rotationally formed as a ball or roller or non-rotating as Schieberrastteile in hemispherical or cylindrical shape, just affect the torque. Strong grinding forces and concise locking positions such as a zero detent position or a main detent often cover the actual idle torque.

Task and solution

The invention is based on the object to provide an aforementioned switching device, can be eliminated with the problems of the prior art and in particular an advantageous way to set a well-defined torque can be achieved in the operation.

This object is achieved by a switching device with the features of claim 1. Advantageous and preferred embodiments of the invention are the subject of further claims and are explained in more detail below. The wording of the claims is incorporated herein by express reference.

According to the invention a braking device is provided on the switching device, which acts on the one hand on the moving part and on the other hand on the base part or the rest of the switching device or its housing. The braking device has a brake element provided with a defined static friction value and sliding friction value, which is advantageously elastic. This braking element is clamped or subjected to compressive stress and arranged with friction upon actuation of the switching device between the moving part and the base part or the rest of the switching device or a housing thereof. It is advantageously provided that both the said compressive stress and the said friction over the entire actuation path of the switching device when turning or pushing are present. It is thus achieved that the initially mentioned idling torque or a braking effect is present at each position or at each point of the actuating travel.

The advantage of the invention is that can be dispensed with other possible components such as progressively wound compression springs or coil springs. These would also mean a higher design effort. Also, too loose turning with undefined torque and thus undefined sense of rotation of the switching device can be avoided in areas outside a detent position.

In the case of the switching device, a detent position system may be present in order to predetermine certain detent positions along the actuation path of the switching device or of the movement part. Such a locking system can be constructed as basically known from the prior art and have a locking part, a compression spring and a detent gate. It is advantageously provided that the braking device is formed independently of the rest position system. Particularly advantageous, it can be spatially separated or spaced therefrom. This makes it possible in general that the braking element or the braking device is provided in addition to other functional parts of the switching device. It is possible that such a brake element could also be integrated in an aforementioned detent system. However, the structure would then be such that it is not absolutely necessary for the locking function.

In an advantageous embodiment of the invention, the switching device is designed for rotary actuation and has a rotary shaft along a rotation axis. It can be provided that the braking device surrounds the axis of rotation radially and has a distance thereto. By a slightly greater distance from the axis of rotation, a more uniform and manufacturing tolerance independent adjustment of the desired static friction or sliding friction, so the braking effect can be achieved.

In an advantageous embodiment of the invention, the braking device has two surfaces which are moved past each other upon actuation of the switching device. Between these surfaces, the braking element is arranged and acts between them or on them. Especially in a switching device designed for rotary actuation, it is advantageous if the surfaces face each other radially, that is to say form an inner surface and an outer surface. The moving part is advantageously radially inside or is an inner part with an inner surface. Alternatively, it is possible for the surfaces with the braking element to oppose each other axially, with radial surfaces being preferred.

Preferably, a braking element is in the form of a closed ring which extends in a radial plane and radially surrounds the axis of rotation. This ring thus extends between the aforementioned inner part and an outer part, for example a part of the housing or a Counter bearing, or between inner surface and outer surface. A ring as a braking element may preferably have a rounded or circular cross-section.

The brake element can advantageously be fastened or mounted on the movement part and project from it in such a way that it bears against the base part with friction and a certain compressive stress. Especially in the above-mentioned case, when the moving member is an inner part and surrounded by the base member, the brake member, especially in the form of an aforementioned ring, can be more easily slipped over the moving member for mounting.

The braking device is formed in a preferred embodiment of the invention so that it acts over an entire actuation path of the switching device. Then, an overall very pleasant and tactile satisfactory operation of the switching device can be achieved.

In a preferred embodiment of the invention can be used as a braking element, an elastic member or it consists of elastic material. Elastomers such as rubber or silicone or silicone rubber are advantageously used here. Static friction and sliding friction can be determined by this material selection, both by their surface properties and by their elasticity properties or compressibility. Likewise, by the formation of the voltage applied to the brake elements surfaces, the resulting braking effect can be influenced.

In one embodiment of the invention, the braking device may be provided between a rotary shaft along the axis of rotation of the switching device and a guide of the rotary shaft in the housing of the switching device, in which case the guide is to be regarded in the housing as a base. This can be advantageous at a front side of the housing, which sits under a panel or points to the handle. The brake element can be applied directly to the rotary shaft, so rub or stored in it. For this purpose, a groove may be formed in the rotary shaft, in which the brake element is arranged largely sunk. With an overhanging area or part, the brake element can rest against the housing or an inner side of the guide as another surface. Advantageously, it sits substantially rotationally fixed in the groove and rubs or brakes on the inside of the guide.

The rotary shaft may be made of metal so that a groove for the brake member can be generated therein or by a rotating or machining operation. The brake element or the groove assigned or opposite surface of the guide of the rotary shaft in the housing of the switching device is advantageously smooth without recesses, projections odgl ..

In a further embodiment of the invention can be provided that the braking element rests with certain, constructive predetermined compressive stress on the base. Here, a pre-pressing of the brake element between the movement part and the base part or between the two moving past each other surfaces. Such pre-pressing can be provided to increase the friction and thus to increase the braking effect. A braking element may be pre-pressed or compressed by 5% to 30%, preferably about 10% to 20%, of its thickness.

In a further embodiment of the invention may be provided to ensure advantageous or permanently same braking characteristics that the brake element is additionally provided with a lubricant or lubricant. Thus, certain static friction values and sliding friction values can be set as desired for certain applications. A lubricant can be selected from the group of PTFE, non-resinating greases or oils. Especially in the aforementioned elastomers such as rubber can by a lubricant the Stiction can be reduced, so that there is no unwanted high breakaway torque after prolonged non-actuation of the switching device. Although this also reduces the sliding friction along the actuation path. However, this can in turn be increased by an increased aforementioned compressive stress of the brake element between the two braking surfaces moved past one another.

A torque generated by a braking device according to the invention can be between 1 Ncm and 10 Ncm, advantageously about 4 Ncm. With these friction values it can be provided that the static friction value is only insignificantly above the sliding friction value. This can preferably be achieved by the mentioned lubricant.

These and other features will become apparent from the claims but also from the description and drawings, wherein the individual features each alone or more in the form of sub-combinations in an embodiment of the invention and in other fields be realized and advantageous and protectable Represent embodiments for which protection is claimed here. The subdivision of the application into intermediate headings and individual sections does not limit the general validity of the statements made thereunder.

Brief description of the drawings

Fig. 1

eine schematische Seitenschnittdarstellung durch ein erfindungsgemäßes Schaltgerät, das in ein Elektrogerät mit einer Bedienblende eingebaut ist,

Fig. 2

eine Vergrößerung des Schaltgeräts aus Fig. 1 mit Anordnung eines Gummirings als Bremselement zwischen Bewegungsteil und Gehäuse als Grundteil, wobei der Gummiring in dem Bewegungsteil gelagert ist,

Fig. 3

eine Abwandlung der Anordnung aus Fig. 2, bei der der Gummiring am Gehäuse gelagert ist,

Fig. 4

eine weitere Abwandlung des Schaltgeräts aus Fig. 1 mit einem Gummiring als Bremselement, der zwischen der Unterseite des Bewegungsteils und einem Gehäuseboden angeordnet ist,

Fig. 5

eine nochmals weitere Abwandlung des Schaltgeräts aus Fig. 1 mit einem Gummiring als Bremselement, der direkt an einer Drehwelle angeordnet ist und

Fig. 6

ein Diagramm des erzeugten Drehmoments über dem Drehwinkel.

Embodiments of the invention are shown schematically in the drawings and are explained in more detail below. In the drawings show:

Fig. 1

a schematic side sectional view through a switching device according to the invention, which is installed in an electrical appliance with a control panel,

Fig. 2

an enlargement of the switching device Fig. 1 with the arrangement of a rubber ring as a braking element between the moving part and the housing as the base part, wherein the rubber ring is mounted in the moving part,

Fig. 3

a modification of the arrangement Fig. 2 in which the rubber ring is mounted on the housing,

Fig. 4

another modification of the switching device Fig. 1 with a rubber ring as a braking element, which is arranged between the underside of the moving part and a housing bottom,

Fig. 5

a further modification of the switching device Fig. 1 with a rubber ring as a braking element, which is arranged directly on a rotary shaft and

Fig. 6

a diagram of the generated torque over the rotation angle.

Detailed description of the embodiments

In Fig. 1 an inventive electromechanical switching device 11 is shown in a simplified sectional view, which has a housing 13, a mounted in the housing movement member 15 in the manner of a rotor and an outgoing rotary shaft 16. On the movement part 15, electrical or sensory devices such as contact switches, magnetic field sensors or the like can be in a manner not shown. be provided, which detect a movement as a rotary movement or a rotational movement position and output as a control signal. This is familiar to the person skilled in the art so that it will not be described further here.

The rotary shaft 16 passes through an aperture 18 of an electric appliance, not shown, for example, a cooker. At the front of the rotary shaft 16, a handle 19 is mounted in the manner of a rotary knob, with which an operator can rotate the switching device 11 and thus the moving member 15.

Radially outside of the movement part 15 extends in the housing 13, a counter-bearing ring 21. This could be formed at radially further outwardly drawn movement part 15 of a housing wall or the inside thereof. However, since such switching devices 11 and their housing 13 are often formed rectangular, such an abutment ring 21 is advantageously formed on an inwardly facing side, which is referred to here as outer surface 22, just as circular as the movement part 15 with its outside, here as Inner surface 23 is designated. The counter-bearing ring 21 corresponds to the aforementioned base.

Furthermore, in Fig. 1 illustrated how the rotary shaft 16 is extended, so to speak, or passes through the moving member 15 and has below a latching device 25, which corresponds to the aforementioned detent position system. This will not be detailed at this point, but may, for example, according to the aforementioned DE 8716921 U1 be educated. It also acts between the rotary shaft 16 and the housing 13 of the switching device 11.

In magnification in Fig. 2 is the right portion of the inner surface 23 of the moving part 15 and the outer surface 22 of the counter-bearing ring 21 shown in high magnification. It can be seen that in the inner surface 23 of the movement part 15, a recess 27 is provided, which is formed circumferentially. In this recess 27 sits a rubber ring 28, which is already in Fig. 1 is indicated between the inner surface 23 and outer surface 22nd

The rubber ring 28 has a circular cross-section in the non-inserted state and, as can be seen, is squeezed by the force-bearing or pressure-exerting abutment on the outer surface 22 of the counter-bearing ring 21 into a somewhat flattened shape. Possibly, this rubber ring 28 in addition to an aforementioned Lubricant be provided or the recess 27 so be partially filled, whereby a kind of permanent lubrication can be achieved. It is easy to see that upon rotation of the moving part 15 relative to the counter-bearing ring 21, the rubber ring 28 rubs between the inner surface 23 or even the surface of the recess 27 and the outer surface 22. In this way, the braking effect described above can be generated or a corresponding torque, which is noticeable to an operator on the rotary shaft 16 and the handle 19. This braking effect is also position-independent and regardless of whether the rotation is slow or fast, at least if this is within normal limits.

A facilitated insertion of the movement part 15 in the counter-bearing ring 21 is achieved by an insertion bevel 30 at the lower end of the moving part 15. Another such insertion bevel 31 is provided at the top of the counter-bearing ring 21. This is more important because it must compress the normally further protruding from the recess 27 rubber ring 28.

In Fig. 3 is a modification of the arrangement Fig. 2 shown. Although here is also a rubber ring 28 'between a moving part 15' and a counter-bearing ring 21 'accordingly Fig. 1 , However, here a recess 27 'on the counter-bearing ring 21' or its outer surface 22 'is provided, while the inner surface 23' of the moving part 15 'is straight or has no recess.

Again, the moving part 15 'is provided with an insertion 30', but above, since it is introduced from below into the counter-bearing ring 21 '. Furthermore, this insertion bevel 30 'must compress the rubber ring 28' during insertion. A corresponding insertion bevel 31 'is provided below on the counter-bearing ring 21'.

While in the embodiment according to Fig. 2 the rubber ring 28 reasonably fed or tight or very slightly tense in the recess 27 can sit on the moving part 15, wherein the gliding is facilitated by the insertion 30 below the movement part 15, he should in the embodiment of Fig. 3 quasi be pressed by its shape outwardly into the recess 27 '. So how he in Fig. 2 in the loose state should have a slightly smaller diameter than the recess 27 inside, it should be in Fig. 3 in the loose state have a slightly larger diameter than the recess 27 'outside.

Even if the recesses 27 and 27 'openings of the outer surface or inner surface of the moving part and the counter-bearing ring, so their radially outward or inward-facing surfaces are virtually seen as part of the inner surface and outer surface. Here rubs namely the rubber ring with rotary actuator.

In yet another embodiment of the invention, a recess for the rubber ring with half depth can be provided both on the moving part and on the counter bearing ring. But then there is a risk that he slips when inserting.

In yet another alternative embodiment of the switching device 11 "accordingly Fig. 4 a latching device 25 "is provided where in Fig. 1 the braking device is arranged. In extension of the rotary shaft 16 "is close to a housing bottom 14", the braking device is provided. For this purpose, in turn, the disk-like movement part 15 "extends to just before the housing bottom 14". On its side pointing downwards, a recess, which is not shown here in detail, is provided, which is designed as an extension in the manner of an annular ring about the rotary shaft 16 "or its axis of rotation. This rubs thus upon rotation of the switching device 11 "on the one hand in its recess on the moving part 15" itself and on the other hand on the housing bottom 14 ". A biasing force acting on the rubber ring 28" similar to FIGS. 2 and 3 can be achieved here by the fact that the moving part 15 "presses with force against the housing bottom 14" and thereby slightly compresses the rubber ring 28 ".Lubricants or the like may also be provided here.

Also in the embodiment according to Fig. 4 are the actual facilities, which recognize the rotational operation of the switching device 11 "or a rotational position, not shown.

In Fig. 5 a further switching device 111 is shown with a housing 113 which is open at the bottom and is mounted on a circuit board 114 as a housing bottom. In the switching device 111 is located as a moving part 115, a rotor made of plastic, which is sprayed onto a rotary shaft 116 made of metal or otherwise applied. Rotary shaft 116 and rotor form the aforementioned movement part.

The rotary shaft 116 extends in a known manner to the front or top of the housing 113 in a guide 117 and can there by an indicated latching connection or the like. be held in the axial direction, while a rotational movement is well possible. The guide 117, which corresponds to the base part mentioned at the beginning, has the outer surface 122 towards the rotary shaft 116, while the corresponding surface of the rotary shaft 116 is the inner surface 123 of this guide or mounting. In the inner surface 123 of the rotary shaft 116, a recess 127 is provided, which is designed as a circumferential groove with exemplary rectangular cross-section and is introduced by turning, preferably as precise CNC turning, in the rotary shaft 116. Thus, a bearing for a rubber ring 128 disposed therein can be provided, which is very precise. This ensures that the rubber ring 128 protrudes with a precisely defined extent from the recess 127 or over the inner surface 123 and thus precisely defined on the outer surface 122 of the guide 117 and the housing 113 is applied. Thus, the braking torque generated by the braking effect is well defined. Finally, a latching device 125 is shown in the side view.

The advantage of the arrangement of the rubber ring 128 as a braking element of the braking device directly on the rotary shaft 116 is that then a small radius is present in the area in which the rubber ring 128 rests with its outer diameter on the outer surface 122 and rubs along. Thus, with these small diameters greater precision is possible and thus a more precisely definable and repeatable braking torque or torque in the aforementioned areas. Also by generating the recess 127 in the metallic rotary shaft 116, a very high precision is possible, especially by the possibility of turning or CNC turning.

The Fig. 6 shows a diagram of the embodiment of the Fig. 2 which torque M is present at which angle of rotation along the X-axis or can be felt by the operator on the handle 19. Significantly, several strong rashes are seen as the main latching steps of the latching device 25, for example, at a rotation angle of about 16 ° and almost 40 °. Between these notches, however, the torque is fairly even, at about 4 Ncm. In the range of a rotation angle between about 250 ° and about 330 ° it drops slightly.

Claims (15)

Electromechanical switching device for rotary operation or sliding operation with a moving part with a handle for an operator for rotary operation or sliding operation, wherein the moving part is mounted on a base, in particular a housing of the switching device, for rotational or sliding operation, characterized in that a braking device is provided which engages the moving part and on the base part or the other switching device, wherein the braking device has a provided with a defined static friction coefficient and Gleitreibungswert braking element, wherein the brake element with compressive stress and friction upon actuation of the switching device between the moving part and the base part or the rest of the switching device is arranged. Switching device according to claim 1, characterized by a detent position system for specifying certain detent positions along an actuation path of the switching device or the moving part, wherein preferably the detent system comprises a detent part, a compression spring and a detent gate, wherein preferably the detent system is independent of the braking device, in particular spatially separated or at a distance. Switching device according to claim 1 or 2, characterized in that the braking element is provided in addition to other functional parts of the switching device. Switching device according to one of the preceding claims, characterized in that it is designed for rotary actuation with a rotary shaft along an axis of rotation, wherein the braking device the axis of rotation radially surrounds and has a distance therefrom. Switching device according to one of the preceding claims, characterized in that the braking device comprises two upon actuation of the switching device past each other moved surfaces between which the brake element is arranged and acts, preferably the surfaces are radially opposite each other, wherein in particular the moving part is radially inward. Switching device according to one of the preceding claims, characterized in that the braking element is a closed ring, preferably with a rounded or circular cross-section which extends in a radial plane and radially surrounds the axis of rotation. Switching device according to one of the preceding claims, characterized in that the braking element is an elastic member, preferably made of elastomer such as rubber or silicone, by the choice of material static friction and sliding friction can be determined. Switching device according to one of the preceding claims, characterized in that the braking device is designed so that it acts over an entire actuation path of the switching device. Switching device according to one of the preceding claims, characterized in that the braking element is attached to the moving part or mounted and rests against the base part with friction and a certain compressive stress. Switching device according to one of the preceding claims, characterized in that the braking device between a rotary shaft is arranged along the axis of rotation of the switching device and a guide of the rotary shaft in the housing of the switching device as a base, in particular on a front side of the housing facing the handle. Switching device according to claim 10, characterized in that the braking element bears directly on the rotary shaft, wherein preferably in the rotary shaft, a groove is formed, in which the braking element is mounted for the most part sunk, wherein it is provided with an outwardly facing portion of the housing or a Inside the guide of the rotary shaft rests in the housing. Switching device according to claim 10 or 11, characterized in that the rotary shaft is made of metal and a recess or groove for the brake element is generated therein or thereto by a rotating machining operation, preferably the associated surface of the guide of the rotary shaft in the housing of the switching device smooth is without recesses, protrusions odgl .. Switching device according to one of the preceding claims, characterized in that the braking element with structurally predetermined compressive stress between the moving part and the base or switching device is arranged for pre-pressing of the braking element, wherein preferably the pre-pressing of the braking element a Pressweg of 5% to 30% of the thickness of the braking element in Prepressing direction, in particular about 10% to 20%. Switching device according to one of the preceding claims, characterized in that the braking element is provided with additional lubricant or has on its outside for adjusting certain static friction values and sliding friction, wherein preferably a lubricant selected from the group PTFE, non-resinous greases or oils. Switching device according to one of the preceding claims, characterized in that the static friction value is only slightly above the sliding friction value.

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