Abstract:
An actuating apparatus includes a housing, an actuating unit, a receiver element, and a transmitter element. The actuating unit comprises a first end with a circular arc-shaped contour whose circular arc central axis is configured to act as a first pivot axis. The actuating unit is configured to be moved via an actuator and to undertake a translational main movement and a pivoting movement. The translational main movement is superimposed by the pivoting movement. The receiver element is fixedly arranged in the housing. The transmitter element comprises a magnetic field. The transmitter element is configured to be translationally movable, to be biased so as to bear against the first end of the actuating unit, and to cooperate with the receiver element.

Description:
CROSS REFERENCE TO PRIOR APPLICATIONS 
       [0001]    This application is a U.S. National Phase application under 35 U.S.C. §371 of International Application No. PCT/EP2012/063978, filed on Jul. 17, 2012 and which claims benefit to German Patent Application No. 10 2011 054 082.2, filed on Sep. 30, 2011. The International Application was published in German on Apr. 4, 2013 as WO 2013/045132 A1 under PCT Article 21(2). 
     
    
     FIELD 
       [0002]    The present invention relates to an actuating apparatus with an actuating unit which is movable via an actuator, whose translational main movement is superimposed by a pivoting movement, a translationally movable transmitter element with a magnetic field which bears on a first end of the actuating unit in a pressure-loaded manner and which cooperates with a receiver element fixedly arranged in a housing. 
       BACKGROUND 
       [0003]    In the field of vehicle construction, such actuating apparatuses can find many applications in the context of an internal combustion engine. Exhaust gas recirculation valves, waste gate valves, register flaps or VNT actuators can, for example, be driven by such actuation apparatuses. 
         [0004]    These actuating apparatuses have an electric motor as the drive unit via which a transmission and a downstream crank is driven or via which a crank is driven directly. The crank is operatively connected with a slotted guide plate in a drive element acting in a rotator manner, via which the movement of the electric motor is converted into a substantially linear movement of an actuating element. In contrast to linear, pneumatically, or electromagnetically operated actuators, electromotive actuators allow for a finer positioning of the downstream actuating element, as well as for a greater actuating force by varying the rotatory lever, which effect can be intensified further by an intermediate transmission. 
         [0005]    It is reasonable for various reasons not to convert the rotational movement into an exclusively linear movement of the downstream actuating element, but to also allow radial movement components. This can reduce production and assembly costs. 
         [0006]    U.S. Pat. No. 6,886,546 B1 describes a rotationally operated poppet valve whose valve rod is not exclusively moved rotationally and is not moved in a plain bearing, but also has movement components radial to the main direction of movement. 
         [0007]    The position of the actuating element must be known in order to be able to control such an actuating apparatus as desired. A magnet is usually coupled with a Hall sensor for this purpose. The measurement is contactless and thus free of wear. The measurement can be provided directly at the drive or at transmission components which has the advantage that, in applications under high thermal loads, such as exhaust gas recirculation valves, the magnet and the Hall sensor cannot be damaged by the occurring high temperatures. This positioning has the disadvantage, however, that tolerances in the drive components cause a high measuring inaccuracy. For this reason, it is attempted to determine the position of the actuating element directly at the actuating element or at a component making the same linear movement as the actuating element. 
         [0008]    DE 10 2009 054 311 A1 describes a valve device in which a rotational movement of an actuator is converted into a translational movement of an adjusting element adjusting the valve, wherein the position of the actuating element is determined using a carrier element rigidly connected with the adjusting element and carrying the magnet, and a contactless sensor measuring the position of the magnet. 
         [0009]    Since the movement in this case is not, however, purely translational, which would compromise a measurement using only one sensor, at least two sensors are required in order to first determine the spatial position of the actuator element and to calculate the translational proportion therefrom. The use of two sensors entails higher material costs. 
       SUMMARY 
       [0010]    An aspect of the present invention is to provide an actuating device having an actuating unit which can be moved via an actuator, the translational main movement of which is superimposed by a pivoting movement, wherein it is possible to determine the exact position of the actuating element in a simple and economic manner. 
         [0011]    An actuating apparatus includes a housing, an actuating unit, a receiver element, and a transmitter element. The actuating unit comprises a first end with a circular arc-shaped contour whose circular arc central axis is configured to act as a first pivot axis. The actuating unit is configured to be moved via an actuator and to undertake a translational main movement and a pivoting movement. The translational main movement is superimposed by the pivoting movement. The receiver element is fixedly arranged in the housing. The transmitter element comprises a magnetic field. The transmitter element is configured to be translationally movable, to be biased so as to bear against the first end of the actuating unit, and to cooperate with the receiver element. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]    The present invention is described in greater detail below on the basis of embodiments and of the drawings in which: 
           [0013]      FIG. 1 : shows a side elevational view of an actuating device of the present invention, illustrated in section; and 
           [0014]      FIG. 2 : shows a side elevational view of the actuating device of the present invention in  FIG. 1 , illustrated in partial section. 
       
    
    
     DETAILED DESCRIPTION 
       [0015]    Only the translational component of the movement of the actuator unit is measured because the first end of the actuating unit has a circular-arc shaped contour, where the central axis of the circular arc is a first pivot axis. The necessity of using two Hall sensors measuring the movement of the actuating elements in two mutually perpendicular directions is therefore obsolete. The material costs are therefore reduced, and the calculation of the translational component of movement is avoided. The reliability of the sensor unit is further doubled due to the omission of one of the sensors. 
         [0016]    In an embodiment of the present invention, the first pivot axis can, for example, be the central axis of a cylindrical bearing pin. The pivoting movement of the actuating element can thereby be realized in a simple manner. 
         [0017]    In an embodiment of the present invention, the transmitter element can, for example, be a magnet or a carrier element with a magnet. This has the advantage that a magnet is particularly well suited for a contactless measurement and can be positioned freely in the carrier element, thereby providing more room for positioning the receiver element. 
         [0018]    In an embodiment of the present invention, a spherical segment shaped surface can, for example, be formed at the first end of the actuating unit whose center is the intersection of the first pivot axis and a second pivot axis orthogonal to the first pivot axis. It is thereby possible to compensate for pivoting movements in all directions orthogonal to the translational main direction of movement of the actuating unit in order to measure only the translational component. 
         [0019]    In an embodiment of the present invention, the first end of the actuating unit can, for example, be a rod head fastened to an actuating element. The contour can be formed particularly easily on the surface of the rod head. 
         [0020]    In an embodiment of the present invention, the housing can, for example, be provided with a stationary guide for the transmitter element. The magnet thereby makes exactly the same translational movement as the actuating unit. 
         [0021]    In an embodiment of the present invention, the guide can, for example, be formed integrally with the housing. The number of parts required is thus reduced and, as a consequence, the material and assembly costs are also reduced. 
         [0022]    In an embodiment of the present invention, a resilient element can, for example, directly or indirectly bias the transmitter element against the first end of the actuating unit. This has the advantage that the magnet is always, even against the action of gravity, moved in proportion to the translational main direction of movement of the actuating unit. 
         [0023]    In an embodiment of the present invention, the resilient element can, for example, be a spring. A spring is corrosion-resistant and also thermally resistant. 
         [0024]    In an embodiment of the present invention, the transmitter element can, for example, be at least partially hollow and be closed on its side facing the actuating unit. A part of the spring and of the guide can thus be disposed in the transmitter element, whereby the structural space required is reduced. 
         [0025]    In an embodiment of the present invention, the spring can, for example, surround the transmitter element. The spring is thereby guided and a kinking of the spring prevented. 
         [0026]    In embodiment of the present invention, the spring can, for example, at least partially be surrounded by the guide and abut against the housing. This has the advantage that the spring is protected against the outside. 
         [0027]    In an embodiment of the present invention, the guide can, for example, be at least partially surrounded by the spring. This is advantageous in that less material and structural space is required for the guide. 
         [0028]    In an embodiment of the present invention, the transmitter element can, for example, at least partially surround the guide. The transmitter element can thereby be guided in a particularly safe manner and, at the same time, can no longer get caught in the windings of the spring. 
         [0029]    In an embodiment of the present invention, the guide can, for example, at least partially surround the transmitter element. This allows for the realization of stable guides. 
         [0030]    In an embodiment of the present invention, a thermally insulating element can, for example, be arranged between the magnet and the actuating unit. The thermal load on the magnet is thereby reduced, whereby its durability is enhanced. 
         [0031]    In an embodiment of the present invention, the transmitter element can, for example, have a circumferential protrusion on its side facing the actuating unit, the protrusion being biased by the spring. The spring can thereby surround the guide and the transmitter element, thereby simplifying assembly. 
         [0032]    In an embodiment of the present invention, the thermally insulating element can, for example, be formed integrally with the rod head or be formed integrally with the transmitter element. The number of parts used is thus reduced, thereby reducing assembly costs. 
         [0033]    In an embodiment of the present invention, the sensor can, for example, be cast or injection molded into the housing. This has the advantage of protecting the sensor from environmental influences. 
         [0034]    An actuating device is thus provided which allows for an exact determination of the translational component of movement of the not purely translational movement of the actuating unit in an economic and simple manner. 
         [0035]    Further features and an embodiment are hereinafter described with reference to the drawings. 
         [0036]    The actuating device  10  is composed of a two-piece housing  16  in which an electric motor, serving as the drive unit  8 , is arranged in a correspondingly shaped seat  9  in the housing  16 . The housing  16  is of a two-piece structure, the two housing halves being fixedly connected with each other by housing screws  54 . 
         [0037]    Via a transmission (not illustrated), the drive unit  8  drives an input shaft s(not illustrated), on which an eccentric  40  is mounted, with an eccentric output bolt  42  being fastened at the opposite end thereof, the eccentric output bolt  42  extending in parallel with the input shaft so that the input shaft, the eccentric output bolt  42  and the eccentric  40  form a crank. 
         [0038]    A bearing (not illustrated) is arranged on the eccentric output bolt  42 , which bearing rolls in a slotted guide plate  44  of a drive element  12 . 
         [0039]    The drive element  12  is substantially of a disc-shaped design and is provided with a bore in a first end portion (not visible in the drawings), through which bore a rotation axis extends in the form of a bolt rotationally supported in bearings, the bolt being fixedly connected with the drive element  12  so that the drive element  12  is rotatably supported along the plane of its extension by means of bearings. 
         [0040]    The drive element  12  has a shaped through hole  46  formed therein, which has a circular arc shaped inner contour  38  as illustrated in  FIG. 1 . In this shaped through hole  46 , a spherical ring shaped bushing  22  of plastic material with an outer contour  34  corresponding to the circular arc shaped inner contour  38  of the shaped through hole  46 , whereby the bushing  22  is supported in the shaped through hole  46  in the drive element  12  for pivotal movement about the pivot axis  30 , whereby it is possible to compensate an offset between the actuating device and a valve to be actuated via the actuating element  14 , which offset is caused by manufacture and results in tensions. 
         [0041]    A cylindrical bearing pin  20  is rotatably arranged in the bushing  22 , which bearing pin  20  has the same central axis  28  as the bushing  22 . On either side, the bearing pin  20  projects into bores  48  in legs  50  of a U-shaped rod head  24  and is fixedly connected therewith. The bushing  22  is secured against axial displacement by means of the two legs  50  of the rod head  24  that contact the bushing  22  on either side. 
         [0042]    The end of the actuating element  14  opposite the rod head  24  protrudes outward through a housing opening  52 . The housing opening  52  is substantially formed as a through bore whose diameter, however, is larger than that of the actuating element  14  so that the latter can make a tilting movement within the housing opening  52 . The housing opening  52  is closed with an elastomeric ring  56  fixed in the housing opening  52  in the housing  16 , the elastomeric ring  56  radially surrounding the actuating element  14 , while at the same time allowing for a tilting movement of the actuating element  14 . 
         [0043]    A surface  62  of the rod head  24  has a spherical segment shaped, wherein a center  70  of the spherical segment shaped surface  62  is the intersection of the pivot axes  30  and  32 . The surface  62  is biased towards the actuating element  14  by a carrier element  68 , the carrier element  68  surrounding a guide (not illustrated) formed in the housing  16  and translationally movable in the main direction of movement of the actuating element  14  and containing at least one magnet  72 . A spring  64  in the form of a helical spring is the carrier element  68  and is arranged in the housing  16  to surround the guide, wherein one end of the spring  64  abuts against the housing  16  and the other end rests on a circumferential projection  74  of the carrier element  68  so that the carrier element  68  is pressed towards the rod head  24 . The surface  76  of the carrier element  68  that biases the surface  62  of the rod head  24  is plane. A non-illustrated receiver element in the form of a Hall sensor is arranged in the housing  16 , which measures the position of the magnet  72 , whereby the position of the actuating element is determined in a manner known per se. 
         [0044]    When the drive unit  8  is activated, the transmission rotationally operates the input shaft and, together with the same, also the eccentric  40 . The eccentric output bolt  42  thereby moves around the input shaft along a circular arc, with the bearing arranged on the eccentric output bolt  42  rolling in the slotted guide plate  44 , whereby the drive element  12  rotates about its rotational axis. The bushing  22  guided in the shaped through hole  46  in the drive element  12  is thus moved around the rotational axis of the drive element  12  along a circular arc-shaped path. 
         [0045]    The rotational axis and the bushing  22  are arranged so that the circular arc-shaped path, along which the bushing  22  moves, has a clearly more important component in the main direction of movement of the actuating element  14  than in a direction perpendicular thereto. The actuating element  14  is correspondingly moved along the central axis  28  via the rod head  24  and the bushing  22 . The circular arc-shaped path at the same time causes a slight tilting movement about pivot axis  32 . 
         [0046]    Since the surface  62  of the rod head  24  has a spherical segment-shaped contour, around the center  70  of which the actuating unit  18  pivots, the pivoting causes no displacement of the carrier element  68 . Only the translational main movement is transferred onto the carrier element  68  and is measured with the Hall sensor. Similarly, a pivoting movement around the pivot axis  30 , which may be caused by manufacturing and assembly tolerances, is compensated by the surface. 
         [0047]    An exact measurement of the adjustment path of the actuating element is thus achieved with only a single sensor. 
         [0048]    It should be clear that the scope of protection of the present application is not restricted to the embodiments described. In particular, various applications of the actuating device are conceivable and also the structure of the device can be modified. It should accordingly be clear that any translational movement of an element, superimposed by a pivoting movement, can be detected in this manner by a corresponding design of the point of support. The present invention is not limited to embodiments described herein; reference should be had to the appended claims.