Abstract:
The invention relates to a sensor-controlled anti jamming device for preventing jamming of an object, in particular in or for a motor vehicle. Said device comprises a body part and a motor-actuatable component which is connected in a pivotable manner to the body part, at least one support element which, when the component is in the open state, supports the component against the body part, and at least one capacitive sensor element which is arranged, when the component is open, between said component and the body part, and is configured such that in a closing step, an object can be detected in a predefined jamming area between the component and the body part.

Description:
[0001]    The present invention relates to a sensor-controlled anti-trapping device for preventing trapping of an object, in particular in or for a motor vehicle. The invention also relates to a corresponding motor vehicle. 
       TECHNICAL BACKGROUND 
       [0002]    Components in a motor vehicle which can be adjusted by motor are moveable devices such as, for example, sunroofs, tilt and slide sunroofs, side doors, sliding doors and tailgates. The invention and the problems on which it is based will be described below with reference to an anti-trapping device in a vehicle and here to an anti-trapping device in a tailgate of a motor vehicle without, however, restricting the invention to this. 
         [0003]    A motor drive in such a tailgate is configured to move said tailgate from a closed position into an opened position, and vice versa. During a closing process, a trapping event may occur in which, for example, a person&#39;s hand can be placed in the gap between the tailgate and the vehicle body. In order to detect in good time such situations which frequently lead to injuries, and therefore avoid them, electrically activatable components have safety systems. 
         [0004]    There are a large number of different embodiments and variants of such safety systems for making available anti-trapping protection, and said embodiments and variants differ from one another essentially in the method of detection of a hazardous situation. In the field of the motor vehicles, anti-trapping devices in motor-operated components frequently have proximity sensors which operate in a capacitive fashion. German patent applications DE 103 28 929 A1 and DE 40 04 353 A1 respectively describe anti-trapping devices, in particular for window lifters in a motor vehicle, which use capacitive sensors. 
         [0005]    The corresponding capacitive sensor electrodes in the anti-trapping devices can, for example, be integrated into corresponding rubber profiles of the tailgate, which profiles are attached along the clamping edge on the tailgate or the corresponding edge of the vehicle body which is located opposite. Such an arrangement is described, for example, in DE 10 2004 023 285 B3. Alternatively, the capacitive sensor electrodes can also be embodied as strips, such as is described in 10 2005 043 543.3, and for which a patent has been applied for by the applicant, but which has not yet been published on the application date of the present patent application. 
         [0006]    Motor-activated tailgates frequently have support elements which are provided laterally on the tailgate. These support elements are configured to support the tailgate in the opened state. Although the motor vehicle usually has a safety device with anti-trapping device protection, which has capacitive sensor elements, in the region of the tailgate, it is, however, problematic that depending on the location at which the sensor elements are provided there is a certain degree of shielding of a partial region between the tailgate and the vehicle body by the support element itself, which is typically composed of metal. In this shielded region, the anti-trapping protection is not ensured, or is ensured only to a limited degree. 
         [0007]    This problem will be explained briefly with reference to  FIGS. 1   a ,  1   b . In  FIG. 1   a , the sensor element  1  is arranged on an edge  2 , where there is a risk of trapping, of the tailgate  3 . In a region which is denoted by reference symbol  4  in  FIG. 1   a , between the support element  5  and a vehicle body part  6 , a region which cannot be monitored by the sensor element  1  occurs with this arrangement. Conversely in the example in  FIG. 1   b , the sensor element  1  is arranged on an edge  7 , where there is a risk of trapping, of the vehicle body part  6 . Here, the region which is denoted by reference symbol  8 , between the support element  5  and the tailgate  3 , cannot be monitored by the sensor element  1  or can only be inadequately monitored by it. In these two regions  4 ,  8 , a hazardous trapping gap is therefore produced in which anti-trapping protection is not ensured or is only ensured to a limited degree. This is a state which should be avoided as far as possible. 
         [0008]    Against this background, the object of the present invention is to provide anti-trapping protection which can be produced as simply as possible and permits, in particular, as far as possible complete monitoring of the entire region where there is a risk of trapping. 
       SUMMARY OF THE INVENTION 
       [0009]    According to the invention, this object is achieved by means of an anti-trapping device having the features of patent claim  1  and/or by means of a motor vehicle having the features of patent claim  16 . 
         [0010]    Accordingly, there is provision of the following: 
         [0011]    A sensor-controlled anti-trapping device for preventing trapping of an object, in particular in or for a motor vehicle, having a vehicle body part and a motor-activated component which is pivotably connected to the vehicle body part, having at least one support element which supports the component against the vehicle body part in an opened state of the component, and having at least one capacitive sensor element which, in the opened state of the component, is arranged between the component and the vehicle body part, and which is configured to detect an object located in a predetermined trapping region between the component and the vehicle body part during a closing process. 
         [0012]    A motor vehicle having a sensor-controlled anti-trapping device according to the invention. 
         [0013]    The idea on which the present invention is based consists in the fact that a sensor element for monitoring regions where there is a risk of trapping is additionally or alternatively also arranged in the direct region about a support element or a pivoting axle for a motor-activated component. As a result, regions which are, for example, shielded by the support element or else by other vehicle body regions are preferably also monitored. With the present invention it is therefore possible, by comparison with known solutions, to make available significantly improved, optimum anti-trapping protection which is, in particular, also very easy to implement in terms of manufacturing technology and is therefore cost-effective. 
         [0014]    Advantageous refinements and developments of the invention emerge from the further sub-claims and from the description in conjunction with the drawings. 
         [0015]    One preferred refinement provides that the component is pivotably attached to the vehicle body part via a pivoting axle, and in that the predetermined trapping region denotes a first gap in the direct vicinity of the pivoting axle. Additionally or alternatively, the predetermined trapping region denotes a second gap between the vehicle body part and the support element and/or a third gap between the support element and the component. 
         [0016]    In one refinement of the invention, the support element is electrically insulated from the component and/or the vehicle body part. 
         [0017]    In a first, very advantageous refinement of the invention, the sensor element is part of the support element. The sensor element can be attached here to the support element by means of a bonding layer and/or clip closure and/or screwed connection and/or plug-in connection. 
         [0018]    In a second refinement of the invention, a laterally arranged panel element is provided between the component and/or the vehicle body part, wherein the sensor element is part of the panel element. The panel element is preferably attached to the support element here. 
         [0019]    The panel element is typically attached in an electrically insulated fashion to a pivoting axle for the tailgate. It would also alternatively be conceivable for the panel element to be attached in an electrically insulated fashion to the component or to the vehicle body part in the vicinity of a pivoting axle for the component. 
         [0020]    One particularly preferred refinement of the invention provides that a further sensor element is provided which is arranged on that edge of the component where there is a risk of trapping and/or on that edge of the vehicle body part where there is a risk of trapping. 
         [0021]    In one preferred refinement, the anti-trapping device has a contactless proximity sensor. This proximity sensor is preferably a sensor which operates in a capacitive fashion. Other contactless proximity sensors, for example on an infrared, ultrasonic or radar basis, would also be conceivable here. 
         [0022]    In one refinement of the invention, the sensor electrode is embodied as a conductive coating and/or as a conductive wire electrode and/or as a conductive piece of sheet metal and/or as a conductive (metal) foil. This type of sensor electrode can be integrated into the material of the component, of the vehicle body part or of the support element, for example through encapsulation by injection molding. 
         [0023]    Typically, but not necessarily, the support element has a gas pressure spring. Alternatively, it would also be conceivable for the support element to be acted on by a spring-elastic element. 
         [0024]    In one typical refinement, the anti-trapping device has an open-loop control device. This open-loop control device, which typically also contains an evaluation circuit for evaluating the sensor signals, controls the anti-trapping protection as a function of the evaluation of the sensor signals. Typically, but not necessarily, the open-loop control device is arranged within the motor-activated component. In one preferred development the open-loop control device is a component of a control unit for controlling the opening and/or closing process of the component. 
         [0025]    The component is typically provided with a drive motor which moves the motor-activated component as a function of an open-loop control operation of the open-loop control device. For an opening and/or closing process of the component the drive motor acts on an adjustment mechanism, wherein the component is connected to this adjustment mechanism preferably via a driver. 
         [0026]    In one typical refinement, the motor-activated component is embodied as a tailgate or as a trunk lid, which can be activated by means of an electric motor drive. Further applications are, for example, electric sliding doors, side doors, sunroofs and/or tilt and slide sunroofs of a motor vehicle and the like. 
     
    
     
       CONTENTS OF THE INVENTION 
         [0027]    The invention will be explained in more detail below with reference to the exemplary embodiments given in the schematic figures of the drawings, in which: 
           [0028]      FIGS. 1   a ,  1   b  are lateral illustrations of the rear part of a vehicle explaining the general problems; 
           [0029]      FIG. 2  is a lateral illustration of the rear part of a vehicle explaining a first exemplary embodiment of the anti-trapping device according to the invention; 
           [0030]      FIG. 3  is a lateral illustration of the rear part of a vehicle explaining a second exemplary embodiment of the anti-trapping device according to the invention; and 
           [0031]      FIG. 4  is a lateral illustration of a rear part of a vehicle explaining a third exemplary embodiment of the anti-trapping device according to the invention. 
       
    
    
       [0032]    Identical and functionally identical elements, features and signals are, unless stated otherwise, provided with the same reference symbols in the figures of the drawings. 
       DESCRIPTION OF EXEMPLARY EMBODIMENTS 
       [0033]      FIGS. 2-4  are lateral illustrations of the rear part of a vehicle explaining exemplary embodiments of the anti-trapping device according to the invention. 
         [0034]      FIGS. 2-4  show, by way of example, the rear part of a motor vehicle  10  of which only a portion is illustrated. The motor vehicle  10  has a rear-end vehicle body part  11  to which a pivotable tailgate  12  is attached. The tailgate  12  can be moved into an open and closed position in the pivoting direction  16  by means of a rotational axle  13  which is provided on the roof  15  of the motor vehicle  10 , for example a pivot joint  13  which defines a pivoting axis. For this a motor drive (for example in the form of an electric motor) is provided which activates the tailgate  12  by motor by means of an adjustment mechanism (not illustrated in  FIGS. 2-4 ). Depending on the direction of rotation of the motor drive, an opening process or a closing process can therefore be respectively implemented in or counter to the pivoting direction  16 . This opening and closing of the tailgate  12  which is activated by means of the drive motor can be implemented in a large number of embodiments and variants, for example by direct engagement of the drive on the rotational axle  13  or alternatively by means of a lever driver which is attached to the tailgate  12  and to the motor vehicle  10  and is activated by means of the drive. In the present application, more details are not given on the precise configuration of this drive motor with an adjustment mechanism. 
         [0035]    In the examples shown in  FIGS. 2-4 , the tailgate  12  is in the opened state, i.e. it is in a position in which it is pivoted away from the vehicle body part  11  by means of the pivot joint  13 . In this opened state of the tailgate  12 , a region  14  is produced which is located between the tailgate  12  and the vehicle body part  11 . In order to avoid trapping of an object, for example of a hand, in this region  14  in the case of a closing process of the tailgate  12 , the motor vehicle  10  has, in the rear part  12 , an anti-trapping device according to the invention, more details on which anti-trapping device will be given below. 
         [0036]    In the exemplary embodiment in  FIG. 2 , a first sensor element  18  is arranged in the region of an edge  17 , where there is a risk of trapping, of the tailgate  12 . In  FIG. 2 , this first sensor element  18  is arranged more or less along the entire edge  17 , where there is a risk of trapping, of the tailgate  12 . This sensor element  18  is, for example, part of a capacitive proximity sensor. The sensor element  18  is configured to monitor the region  14  between the tailgate  12  and vehicle body part  11  with respect to a situation where there is a risk of trapping when the tailgate  12  closes. 
         [0037]    In order to support the tailgate  12  against the vehicle body part  11 , a support element  19  is provided which, in the opened state of the tailgate  12 , is arranged in the region  14  between the gate  12  and the vehicle body part  11 . In the present exemplary embodiment, the support element  19  contains a gas pressure spring. The support element  19  is connected to these elements  11 ,  12  via a first attachment point  20  on the vehicle body side and via a second attachment point  21  on the tailgate side. 
         [0038]    According to the invention, the support element  19  has a further sensor element  22 . This further sensor element  22  is configured to monitor a region  14 ′ between the support element  19  and the vehicle body part  11  for a situation where there is a risk of trapping. The first sensor element  18  is also designed to monitor the region  14  between the support element  19  and vehicle body part  11 . However, due to the presence of the typically metal, and therefore shielding, support element  19 , the regions  14 ′ in the vicinity of the attachment point  20  are not monitored, or are only inadequately monitored, using the sensor element  18 , for a situation where there is a risk of trapping. For this, the further sensor element  22  is provided, which sensor element  22  is especially configured for monitoring the region  14 ′ where there is a risk of trapping, in the vicinity of the attachment point  20 . Optimum monitoring in order to prevent trapping can therefore be made available over the entire region  14 ,  14 ′ between the tailgate  12  and the vehicle body part  11 . 
         [0039]    The support element  19 , which, for example, is mainly composed of a metal or a metal alloy, is itself preferably used as a sensor electrode for the further sensor element  19 . However, for this purpose the attachment points  20 ,  21  of the support element  19  have to be embodied so as to be electrically insulated from the vehicle body part  11  on the one hand and from the tailgate  21  on the other. This can be implemented, for example, by forming the attachment points  20 ,  21  of the support element  19  by means of spherical heads or rollers which contain an electrically insulating material, for example plastic, at least on their outer surfaces. Additionally or alternatively, the corresponding bearing shells, which serve to hold these spherical heads or rollers, can also have an electrically insulating material on their outer surfaces. 
         [0040]    If the tailgate  12  and/or the vehicle body part  11  are composed of an electrically insulating material at least in the region at which the support element  19  is attached to these elements via the attachment points  20 ,  21 , it is also possible to dispense with the insulation of the bearings of the support element  19 . 
         [0041]    Instead of using, as a further sensor element  22 , an electrically conductive support element  19 , which is for example composed of metal, it is also possible to provide a separate sensor element  22  which is, for example, attached to or provided on etc. the support element  19 . For example, the further sensor element  22  can be bonded by means of a bonded connection, plugged on by means of a plug-type connection, or clipped on by means of a clip connection etc. to the support element  19 . The advantage of a plug-type or clip connection is that the corresponding further sensor element  22  can easily be removed again, which is advantageous, in particular in terms of maintenance. 
         [0042]    An evaluation and open-loop control device  23  is illustrated schematically in the vehicle body part  11 . This evaluation and open-loop control device  23  serves to evaluate the sensor signals S 1 , S 2  which are generated by means of the sensor elements  18 ,  22 . For this purpose, the evaluation and open-loop control device  23  is connected to the first sensor element  18  via a first connecting line  24 . The evaluation and open-loop control device  23  is connected to the further sensor element  22  via a further connecting line  25 . The sensor signals S 1 , S 2  are fed via the connecting lines  24 ,  25  to the evaluation device  23  for evaluation. In the case of the connecting line  25 , said line can, for example, be led out of the support element  19  through corresponding drilled holes or cutouts within the shell or the spherical element in the region of the attachment point  20 . 
         [0043]    The evaluation and open-loop control device  23  is configured to perform evaluation and open-loop control of the opening and closing process of the tailgate  12 . In the case of a hazardous trapping situation in which, for example, trapping in the region of the gap  14  between the tailgate  12  and motor vehicle  10  is imminent, this is detected by means of the evaluation and open-loop control device  23 . The evaluation and open-loop control device  23  is then capable of activating anti-trapping protection, for example in that, in the case of closing of the tailgate  12 , said tailgate  12  is opened again or the closing process is at least stopped. 
         [0044]    The evaluation device can, of course, also be made separate from the open-loop control device  23 , for example the evaluation device can be part of the respective sensor element  18 ,  22  itself. It would also be conceivable to arrange the evaluation and open-loop control device  23  in the tailgate  12 . 
         [0045]    The evaluation and open-loop control device  23  can be formed, for example, as a program-controlled device, for example as a microcontroller or microprocessor, and is typically a component of a control unit. 
         [0046]    Two support elements  19  are typically provided in the rear part. Since these support elements  19  are typically attached symmetrically to lateral edges of the tailgate  12 , a change in capacitance which originates from a change in position of the tailgate  12  and which is detected by the corresponding sensor elements  18 ,  22  can be gated out by forming differences between the corresponding sensor signals. If a situation is present where there is no risk of trapping whatsoever, this formation of differences results in a zero signal. A situation where there is a risk of trapping is detected only if a signal which is different from zero is detected, for example using a corresponding switching threshold for the difference signal, and the corresponding measures for anti-trapping protection can be initiated. These measures may be, for example, to stop the electric motor for the tailgate  12  which is activated by electric motor or else to open the tailgate  12  again using the electric motor. 
         [0047]    The sensor elements  18 ,  22  can, for example, be embodied from a piece of sheet metal, a wire, an electrically conductive layer or the like. In the region of the tailgate  12  and/or of the vehicle body part  11 , the corresponding sensor element  18  can be provided on or attached to the surface of these elements or else arranged in the material of these elements if this material is not electrically conductive. In the case of an electrically conductive material for the elements  11 ,  12 , the corresponding sensor element  18  can also be integrated into a sealing material on the corresponding edges  17 ,  26  where there is a risk of trapping. 
         [0048]    In contrast to the exemplary embodiment in  FIG. 2 , in the exemplary embodiment in  FIG. 3  the sensor element  18  is arranged along an edge  26 , where there is a risk of trapping, of the vehicle body part  11 . While this sensor element  18  is configured to monitor wide ranges  14  between the tailgate  12  and vehicle body part  11  for a situation where there is a risk of trapping, the further sensor element  22  which is arranged in the support element  19  serves the purpose of additionally monitoring a region  14 ″. This additional region  14 ″ is located on the tailgate side in the direct vicinity of the attachment point  21  between the support element  19  and the tailgate  12 . In this arrangement of the sensor element  18  in the region of the vehicle body part  11 , optimum monitoring of the region  14  for a situation where there is a risk of trapping is therefore also ensured. 
         [0049]    In the exemplary embodiment in  FIG. 4 , the support element  19  itself cannot contain a further sensor element  22 , as is the case in the exemplary embodiments 2 and 3. The function of the further sensor element  22  is carried out here by a panel element  27  which is attached to the support element  19 . This panel  27  extends from a region directly in the vicinity of the pivot joint  13  at least partially into the region  14 . The panel  27  is spaced apart here from the tailgate  12  on the one hand and from the vehicle body part  11  on the other. The panel element  27  contains the further sensor element  22 , which is preferably arranged over the entire length of the panel  27 . The panel  27  is typically connected in a moveable fashion to the support element  19  and the pivoting axle  13  so that during a closing process the panel element  27  moves, for example, along a rail on the support element  19  in the direction of the vehicle body part  11 . The panel  27  is preferably clipped onto the support element  19 . It is also essential here that the panel  27  is, in particular, embodied so as to be electrically insulated from the vehicle body part  11  and the tailgate  12 , and typically also from the support element  19 . This can be done, for example, by an electrically non-conductive attachment of the panel  27  to the support element  19  and/or to the pivoting axle  13 . 
         [0050]    The panel  27  is preferably embodied in such a way that in the closed state of the tailgate  12  it can be countersunk in a cutout, especially provided for that purpose, in the vehicle body part  11  or the tailgate  12 . Additionally or alternatively it would also be conceivable for the panel  27  to be embodied in the form of folding bellows which can unfold completely when opening occurs and be folded together completely when closing occurs. 
         [0051]    The panel element  27  can be completely composed of a conductive material, for example a metal or a metal alloy. In this case, the entire panel  27  would carry out the function of the further sensor element  22 . Additionally or alternatively it would also be conceivable for the panel  27  to have suitably shaped, electrically conductive conductor structures which comprise the function of the further sensor element  22 . 
         [0052]    The inventive panel  27  which contains the further sensor element  22  can preferably monitor the entire region  14 ′″ between the tailgate  12 , the vehicle body part  11  and the support element  19  for a situation where there is a risk of trapping. In this context, in particular the region which is otherwise critical in the direct vicinity of the pivot joint  13 , which can otherwise only be monitored inadequately, is now monitored to an optimum degree. Since the panel element  27  in  FIG. 4  protects the entire region  14 ′″, the first sensor element  18  can be dispensed with in this region of the tailgate  12  (or of the vehicle body part  11 ). 
         [0053]    The electrical connection of the panel element  27  to the evaluation and open-loop control device  23  can be implemented by means of a connecting line which is especially provided for that purpose, as is illustrated in analogous fashion in  FIGS. 2 and 3 . It is also advantageous that complex cabling is not necessary for the further sensor element  22  within the panel  27 . Contacts can be formed here, for example, very easily by clipping a sensor element  22  onto the panel  27  or by some other type of surface contact of the sensor element  22 , since good capacitive coupling in the region of several piko-Farads is already sufficient for the reliable functioning of the sensor element  22 . This would also be conceivable by means of a thin insulating layer, for example an electrolytically oxidized layer, a thin surface coating etc. It is very easily possible to form a capacitive sensor element in the case of the exemplary embodiment in  FIG. 4 . The described formation of contacts can, however, also be extended or applied to the exemplary embodiments in  FIGS. 2 and 3  by virtue of the fact that the formation of contacts which has just been described is also used for electrical connection of the support elements  19  to the further sensor element  22  in the examples in  FIGS. 2 and 3 . 
         [0054]    Although the present invention has been described above with reference to preferred embodiments and variants, it is not to be considered as being restricted thereto but rather can, of course, be modified in any desired way. 
         [0055]    In particular, the invention is not to be considered as being restricted to the specific embodiments of the sensor element or to the materials used for the sensor elements or to the materials used for the tailgate, the vehicle body part or the support element. Any material or any object which is electrically conductive can be used as a sensor element, and in this context materials which can very easily be processed in terms of manufacturing technology and attached in terms of mounting technology are preferably used. Such a sensor which emits electromagnetic signals and/or receives them and evaluates them can be used as sensor elements. 
         [0056]    The invention is also not exclusively restricted to a tailgate in a motor vehicle but rather can, of course, also be applied to other motor-activated components such as, for example, side doors, sunroof/tilt and slide sunroof structures, trunk lids, engine hoods and the like. Furthermore, the invention is not restricted exclusively to the field of automobiles but rather can also be used advantageously in other vehicles such as trucks, buses, train cars and the like. 
         [0057]    The drive motor system and adjustment motor system which are described in the patent application are to be understood as merely by way of example and they can be modified as desired without involving an inventive step by a person skilled in the art. 
       LIST OF REFERENCE SYMBOLS 
       [0000]    
       
           1  Sensor element 
           2  Edge where there is a risk of trapping 
           3  Tailgate 
           4  Region where there is a risk of trapping 
           5  Support element 
           6  Vehicle body part 
           7  Edge where there is a risk of trapping 
           8  Region where there is a risk of trapping 
           10  Vehicle, motor vehicle 
           11  Vehicle body part (in the rear part of the vehicle) 
           12  Tailgate, motor-activated component 
           13  Pivot joint, pivoting axle 
           14  Region between tailgate and vehicle body part 
           14 ′- 14 ″″Critical regions 
           15  Roof region of the motor vehicle, roof 
           16  Pivoting direction 
           17  Edge where there is a risk of trapping 
           18  Sensor element, sensor electrode 
           19  Support element 
           20 ,  21  Attachment points (of the support element) 
           22  Further sensor element 
           23  Evaluation and open-loop control circuit 
           24 ,  25  Connecting lines 
           26  Edge where there is a risk of trapping 
           27  Panel, panel element 
         S 1 , S 2  Sensor signals