Abstract:
In order to configure the downshift method, and to create signals for an automobile automatic transmission more conveniently, a tilting device of a multi-function device with at least one moveable magnet element as a downshift sensor device is used. When a pedal element causes actuation of a magnet element, a downshift characteristic curve (KL 3 ) is generated with a curve-shaped increase and a maximum followed by a curve decrease (KLS) that ends in a stop window ( 60 ). A downshift point (KP) is determined using a tolerance window ( 59 ) with a path width, which corresponds to a downshift signal (KS) on a characteristic motion curve (AS) of a motion sensor element.

Description:
BACKGROUND OF THE INVENTION 
     The invention relates to a method for producing downshift signals for an automatic transmission via a pedal device with at least one pedal element that moves about at least one pivot point and includes at least one motion sensor element. 
     The invention also relates to a gas pedal device with at least one gas pedal element that may move about a gas pedal pivot point with respect to a surface element, with a motion sensor element that produces a movement characteristic curve, and a downshift-sensor element, whereby the motion sensor element and the downshift sensor device may be moved at least by movement of the gas pedal element, and also a downshift sensor device to perform the method. 
     A gas pedal device, known from the German Patent No. DE 195 03 335, includes a gas pedal element at whose pivot point is positioned a motion sensor element. A sensor or switch is assigned to the gas pedal element that is controlled by an actuation lever element that can create a downshift signal if necessary. 
     However, it is not indicated in this reference how the sensor or switch is constructed, or how the signal is created and transmitted. 
     Downshift switches, also called “kickdown switches”, are known in which a spring-loaded, tap-shaped pushrod body is pressed via a recess with spring-tensioned spheres. However, the downshift force characteristic curve may be altered only by the shape of the tap, the number and size of spheres, and the spring force of the spheres. Also, as a rule, the strike point of the pushrod body is the signal triggering point to control an automatic transmission. A further disadvantage is that the individual parts of this known downshift switch are subject to mechanical wear and thus subject to failure. The individual parts therefore cause additional inaccuracy. 
     A device for creating selector positions for use as a selector in an automobile on-board computer, in a washing machine control, or a gas pedal device is known from the International Patent Publication No. WO 98 26 341 A1, which is based on the German Patent Nos. DE 196 51 315 A1 and DE 297 14 164 U1. In the most simple embodiment of the selector switch, opposing magnetic units on a rotor are displaced from one position to the next, similar to the action of a mechanical detent mechanism. A position sensor unit is connected with the rotor that issues signals corresponding to each position. The rotor is rotatable about a tilt switch device. The tilt switch includes a tilt switch permanent magnet in a housing element secured to a magnetically. 
     For example, when the rotor is turned, a sensor may be selected in advance by the automobile on-board computer, and this pre-selection may be confirmed by subsequent pressure via the tilt switch. If the rotor is released after this pressure, the permanent magnet returns the rotor to its initial position. 
     SUMMARY OF THE INVENTION 
     Based on this state of the art, an object of the present invention is to better configure the downshift process and the creation of signals for an automobile automatic transmission. 
     Based on the invention, this object is achieved by using a tilting device with at least one movable magnet element as a downshift sensor device. When a pedal element causes actuation of a magnet element, a downshift characteristic curve (KL 3 ) is generated with a curve-shaped increase and a maximum followed by a curve decrease (KLS) that ends in a stop window. A downshift point (KP) is determined using a tolerance window with a path width, which corresponds to a downshift signal (KS) on a characteristic motion curve (AS) of a motion sensor element. 
     The advantages provided by the invention particularly include the fact that a downshift magnetic force characteristic curve is created that may be correspondingly influenced based on the selection of magnetic forces of the magnets used. A further advantage is that the downshift point on this characteristic curve may be positioned beyond the maximum curve value within a tolerance window. A further advantage is that the downshift magnetic force characteristic curve is created using magnets, so that the mechanical parts are kept to a minimum, thus reducing the possibility of overall wear on the switch and allowing maintenance of smaller tolerances. With mechanical downshift switches, the curve maximum value is achieved after about 3 mm; with a magnetic switch, it is achieved after about 0.3 mm. Since the magnetic downshift switch does not have strict tolerance as is the case with mechanical switches, a good Gaussian distribution curve is achieved at the switching point. 
     The rising curve slope may be sinusoidal. It may, however, have another wave-like shape. 
     The curve drop may have a cotangential shape. It may also, however, have another wave-like shape. 
     The magnet counter-element may create a magnetic force progression, thus effectively determining the rising curve slope and the maximum curve value of the downshift magnetic force characteristic curve. 
     Additionally, a pressure spring element may be used that, along with the magnet counter-element, helps determine the curve rising slope of the downshift magnetic force characteristic curve. 
     A rotation angle sensor may be used as a motion sensor element. The sensor may operate according to the Hall principle. Thus, the most accurate motion characteristic curves may be used from which exact downshift signals may be taken. A rotary potentiometer could also be used here. 
     A Hall circuit may be used as the motion switch. It switches precisely at the downshift point, is equally exact, and is as free from external influences as the rotation angle sensor. An electrical switch could also be used as a motion switch that could provide a downshift signal upon actuation. This switch may operate according to mechanical, semi-conductor, or other principles. 
     The advantages connected with this device consist particularly from the fact that the use of magnetic elements to determine the progression of the downshift magnetic force characteristic curve reduces mechanical wear to a minimum. The characteristic curve may thus be significantly affected at critical points such as the rising slope, the maximum, and the falling slope. Instead of the fixed point using a mechanical switch, one may determine during actuation that the downshift point that creates the downshift signal lies beyond the maximum. 
     The repelling-magnet element may be disposed opposite the moveable magnet element on the one side, and opposite the plate element on the other side. 
     Thus, the moveable magnet element may be positioned with one pole opposite the same magnetic pole of the repelling-magnet element and with the other pole at least opposite the plate element. Thus, the curve progression may be very significantly influenced. 
     The curve progression of the characteristic force curve may be further influenced in that a pressure spring element is positioned between the plate element and the moveable magnet element. The pressure spring element may also be positioned between the moveable magnet element and the repelling-magnet element. The spring element may consist of rubber or spring steel. 
     The plate element may be made as a steel washer element. 
     The magnet element is to be moved by a pushrod element. Other elements may be used to move the magnet element. 
     The magnet element and the repelling-magnet element may be in the form of permanent magnets. The downshift magnetic force characteristic curve is effectively influenced by the selection of permanent magnets. 
     The magnet element and/or the repelling-magnet element may be divided into halves of a magnetic north and south pole, whereby the magnetic counterforce may be varied or increased. The magnetic counterforce and thereby also the downshift magnetic force characteristic curve may further be influenced if the magnet element is at least partially surrounded by an iron yoke. 
     Sensors that operate according to the Hall principle or the resistance principle may be used as a motion sensor element. 
     Switches that operate according to the Hall principle, a semi-conductor basis, or a mechanical basis may be used as a motion switch. 
     For a full understanding of the present invention, reference should now be made to the following detailed description of the preferred embodiments of the invention as illustrated in the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 a  is a schematic side view of a first gas pedal device with a downshift sensor device. 
     FIG. 1 b  is a schematic front view of a gas pedal device as in FIG. 1 a.    
     FIG. 2 a  is a schematic side view of a second embodiment of a gas pedal device with a downshift device and a motion sensor device. 
     FIG. 2 b  is a schematic front view of a gas pedal device as in FIG. 2 a.    
     FIG. 3 a  is a schematic, partial cutaway side view of a third embodiment of a gas pedal device with a downshift device and a motion sensor device. 
     FIG. 3 b  is a schematic, partial cutaway front view of a gas pedal device as in FIG. 3 a  with a footboard element. 
     FIG. 3 c  is in a schematic, partial cutaway side view of a gas pedal device as in FIGS. 3 a  and  3   b  in assembled condition. 
     FIG. 3 d  is a cross-sectional view of a film hinge element for a gas pedal module as in FIGS. 3 a  to  3   c  in assembled condition. 
     FIG. 4 is cross-sectional view of a modified form of one embodiment of a rotation angle sensor. 
     FIG. 5 is in a schematic side view of a downshift sensor device. 
     FIGS. 6 a  and  6   b  show different configurations of a device as in FIG.  5 . 
     FIGS. 7 and 8 illustrate different embodiments of a magnet device as in FIG.  6 . 
     FIG. 9 shows various downshift magnetic force characteristic curves of downshift sensor devices as in FIGS. 5 to  8 . 
     FIG. 10 graphically illustrates the movement progression of a gas pedal device with an associated downshift characteristic magnetic force curve and an associated characteristic movement curve parallel to the movement of the gas pedal device. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The preferred embodiments of the present invention will now be described with reference to FIGS. 1-10 of the drawings. Identical elements in the various figures are designated with the same reference numerals. 
     A gas pedal device, as in FIGS. 1 a  and  1   b  comprises: 
     a pedal element  3 , 
     a motion sensor element  2 , and 
     a base plate  4 . 
     Gas pedal element  3  is comprised of a foot pedal element  7  and a pedal lever element  9  that are joined together at a gas pedal pivot point  8  so that they may rotate. From one side, a coupling element  7 ′, that is connected to the base plate  4 , is attached to the foot pedal element  7 . The pedal lever element  9  is connected with the base plate  4  via a pivot pin  1 ′. The pivot pin  1 ′ also represents the gas pedal pivot point  1 . 
     FIGS. 2 a  and  2   b  show another embodiment of a gas pedal device in which the pedal element  13  comprises a pedal lever element  19  with a gas pedal element  17  attached to it. The pedal lever element  19  is secured in the area of a floor part  40  of the vehicle via the pivot pin  11 ′. The pivot pin  11 ′ also forms the gas pedal pivot point  11  here. 
     A motion sensor element  2  (FIG. 1) or  12  (FIG. 2) is positioned at the gas pedal pivot point  10  and  11 , respectively. The motion sensor element  2  or  12  may be configured as a rotation angle sensor  201  or as a rotary potentiometer element  204 . It is, of course, also possible that both a rotation angle sensor  201  and a rotary potentiometer element  204  be positioned at the gas pedal pivot point  1  (FIG. 1) or  11  (FIG.  2 ). 
     The rotation angle sensor  201  is decoupled via a motion-limiting actuator unit  20  opposite the pedal lever element  9  or  19 . 
     The motion sensor element as in FIG. 4 is composed of the stationary unit  219  and the moveable, i.e., rotating unit  220 , as already mentioned. 
     The stationary unit  219  includes a stator element  221  that is comprised of partial stator elements. These partial stator elements have a separation recess (not shown) between them. The partial stator elements of the stator element  221  are shaped as orange-shaped plates, and consist of individual plate packets. The corners of the orange-shaped pieces extending toward the separation recess are deflected at a 45° angle. The stator element  221  is secured to a round plate element  210  by means of tensioning pin elements  233 . 1  or  233 . 2 . The plate element preferably consists of a shaped aluminum plate. The base plate element  210  is drawn into a base element  223 ′. This base element  223 ′ is continued as a stepped element  223 ″. Both are formed monolithically from non-conducting plastic. A central recess in the plate element  210  is provided, opposite the separation recess, into which is inserted a Hall element  222 . 
     The rotating unit  220  includes a ring-shaped magnet element  224 . 
     The ring-shaped magnet element  224  is secured by a pot-shaped magnet bracket element  226 ′. Above this is disposed another pot-shaped friction bearing element  227 . The friction bearing element partially extends into round stepped element  223 ″ and rests on it with its remainder. 
     The round stationary and rotating units  219  or  220  of the rotation angle sensor of FIG. 4, are at least partially surrounded by a housing element  223 . The housing element is so shaped that it partially extends over the friction bearing element to better secure and guide its upper edges. Plug contacts  234  extend out of the housing. 
     FIGS. 3 a  to  3   d  show a gas pedal device  101 . 
     The gas pedal device  101  comprises: 
     a gas pedal element  112 , and 
     a base plate element  113  that is connected at a gas pedal pivot point  111 ,  160 . 
     The gas pedal pivot point is in the form of a barrel hinge link connector  111 . 
     The gas pedal element  112  possesses an overstrike element  123  opposing an understrike element  124  on the base plate element  113  in the area of the barrel hinge link connector  111 . 
     A pedal end  126  of the gas pedal element  112  is located in the area of the barrel hinge link connector  111 . Opposite it is a pedal tip area  125 . A gas pedal actuation surface element designated  127  is opposite a gas pedal underside  128 . The gas pedal actuation surface element possesses an actuation profile in the form of strips, a grid, or similar. Rubber, plastic, or similar materials may be used. On the gas pedal underside of the gas pedal element, corresponding cross strips are arranged that add to the mechanical stability of the gas pedal element  112 . Such cross strips are also on an underside of the base plate element  113 . 
     Two adjacent ski-jump-shaped flat spring elements  114  are positioned between the gas pedal element  112  and the base plate element  113 . 
     For a gas pedal module  101 , fixed spring bracket elements  116 ,  117  are positioned on an end of the base plate element  113  that is opposite the barrel hinge link connector  111 . The one end of the ski-jump-shaped flat spring element  114 ,  115  is held by the fixed spring bracket elements  116 ,  117 . 
     The opposite ends of the flat spring elements  114 ,  115  are each held by spring slide brackets  118 ,  119 . The spring slide brackets  118 ,  119  may be slid along slide rail elements  120 ,  121  that are arranged above a slide surface element  121 . The spring slide brackets  118 ,  119  may also be slid along the slide surface element  121 . The slide surface element  122 , the slide rail elements  120 ,  121  arranged on it, and the spring slide brackets  118 ,  119  free to move on them are arranged on the gas pedal underside  128  at the tip of the gas pedal  125  of the gas pedal element  112 . 
     As FIG. 3 c  shows, a footboard element  140  is positioned on the pedal surface element  127  near the pedal tip  136 . The footboard element includes a footboard body  144  that is secured to the pedal actuation surface element using a tilting element  141 . The tilting element  141  is in the form of a film hinge link. It has an X-shaped configuration in which bent plastic strips are in opposition; the free space between them is filled with foam. 
     Front and rear tilting bodies  142 ,  143  are mounted on the surface element  127  on both sides of the tilting element. The presence or height of the tilting bodies allows definition of motion play of the floorboard body. 
     As FIG. 3 d  shows, the gas pedal pivot point may be elegantly realized as a film hinge element  160  that 
     includes a resilient band  163  that is connected with 
     a pedal anchor body  161  and with 
     a base plate anchor body  162 . 
     The pedal anchor body is anchored via a T-anchor  164  in the gas pedal element  112  and the base plate anchor body is anchored via a T-anchor  165  in the base plate element  113 . Recesses in the T-anchors increase their grip. A rotation angle sensor device  172  ( 201 ) is assigned to the area of the hinge link  111  or the film hinge element  160 . 
     A downshift sensor device, or kickdown switch, is built into these gas pedal devices of differing design. 
     As FIGS. 1 a  and  1   b  show, the downshift sensor device  50  is inserted into the base plate. 
     As FIGS. 2 a  and  2   b  show, the downshift sensor device is attached above the pivot point of the pedal element  13 . For this, an intermediary device is used that actuates the device  50 . 
     For the gas pedal device  101  shown in FIGS. 3 a  to  3   d,  the downshift sensor device  50  is arranged at the tip of the base of a plate element  113 . 
     The installation locations indicated on the gas pedal device as in FIG. 1 a  to FIG. 3 d  are merely examples. The downshift sensor device  50  may be mounted at many other locations. Special intermediary mechanisms may also be provided that transfer gas pedal movement to a corresponding position of the downshift sensor device. 
     The downshift sensor device  50  is shown in FIG. 5 in detail. 
     It consists of a steel washer element  52  on which a pressure spring element  53  is positioned. The pressure spring element is here in the form of a rubber spring that additionally completely surrounds the steel plate washer element  52 . The pressure spring element  53  includes a surrounding rubber ring  53 . 1  that has an essentially triangular cross-section for the formation of spring characteristics. The rubber ring  53 . 1  is supported on an overlay plate  62 . 
     A magnet element  54  is positioned below the steel plate washer element  52 . It is opposite a repelling magnet element  55 . Both magnet elements  54 ,  55  are so positioned that their magnetic north poles oppose each other, so that a magnetic repulsive effect  58  is developed. FIGS. 6 a  and  6   b  show cutaway views of the steel plate element  52 , the magnet  54 , and the pushrod element  51 . As FIG. 6 b  shows, the magnet  54  is surrounded by a U-shaped iron yoke  64 . The north pole N of the magnet extends toward the pushrod element  51  and opposite the magnetic south pole S. This ensures that the steel plate element  52  has a north pole N and the U-shank of the iron yoke  64  has a south pole S and a magnetic short circuit with a highly attractive force is present. FIG. 7 and 8 show that the magnets  54  and  55  each have half a north pole N and half a south pole S. This increases the magnetic force very significantly. 
     A pushrod element  51  sits on the magnet element  54  that is guided by the steel washer element  52  and the pressure spring element  53 . 
     FIGS. 6 a  and  6   b  show cutaway views of the steel plate element  52 , the magnet  54 , and the pushrod element  51 . As FIG. 6 b  shows, the magnet  54  is surrounded by a U-shaped iron yoke  64 . The north pole N of the magnet extends toward the pushrod element  51  and opposite the magnetic south pole S. This ensures that the steel plate element has a north pole N and the U-shank of the iron yoke has a south pole S and a magnetic short circuit with a highly attractive force is present. FIGS. 7 and 8 show that the magnets  54  and  55  each have half a north pole N and half a south pole S. This increases the magnetic force  39  very significantly. 
     FIG. 9 shows various downshift magnetic force characteristic curves KL 1 , KL 2 , KL 3  that may be created by means of the downshift sensor device  50 . The various characteristic curves are formed by the implementation of magnet elements  54 ,  55  that develop magnetic forces of different strengths. Permanent magnets are used as magnet elements. 
     When the pushrod element  51  is actuated, only that force that forces the rubber ring  53 . 1  together must be overcome at first. If the pressure spring element  53  is relaxed, the increasing magnetic opposing force  58 , due to the magnet  55 , determines further curve progression. At the beginning is a curve-shaped increase, particularly a sine wave curve shaped increase, KLA that continues to the curve maximum KLM, somewhere within the range  61  defined by a window  59 . For this, the magnetic force  56  is overcome by the magnetic opposing force  58 . After the curve maximum, a curve-shaped, particularly cotangent curve, decrease KLS continues. This may have a different progression, and is eventually led into a stop region  60 . 
     The creation of downshift signals KS, as result from the preferred embodiments, will now be explained using the gas pedal element shown in FIG. 1 a  and  1   b,  the rotation angle sensor elements shown in FIG. 4, and the downshift sensor device  50  shown in FIGS. 5 to  8  with the downshift characteristic magnetic force curves shown in FIG.  9 . 
     The creation of downshift signals KS, as result from the exemplary embodiments, are explained using the gas pedal element shown in FIGS. 1 a  and  1   b , the rotation angle sensor elements shown in FIG. 4, and the downshift sensor device shown in FIGS. 5 to  8  with the downshift characteristic magnetic force curves shown in FIG.  9 . 
     The creation of downshift signals KS is required only when a brief acceleration of a vehicle with an automatic transmission is necessary. 
     For this, the foot pedal element  7  of the gas pedal element  3  is forced toward the base plate  4 . At this time, the pedal lever element  9  of the pedal element  3  is pressed against the pushrod element  51  of the downshift sensor device  50 . 
     The movement interactions are shown summarized in FIG.  10 . Here, the upper curve shows the force N as a function of the pedal path P. Below this is a motion characteristic curve AS of the rotation angle sensor  201  dependent on rotational angle α that corresponds to the returned pedal path P. 
     Upon sudden depression of the gas pedal element  7 , a pedal path P is pushed back that is shown increasing linearly for the sake of illustration. The rotating unit  219  of the rotation angle sensor is rotated to the same extent. By means of the ring-shaped magnet element  224 , initial voltage values are created using the Hall element  222  that determine the linearly-increasing characteristic curve AS. 
     If the passing maneuver is terminated, the gas pedal element  7  is relieved from tension and the pushrod element  51  is released. The magnet element  54  again immediately moves toward the steel plate element  52  and again presses on the rubber ring  53 . 1  of the pressure spring element  53 . 
     If it is required to further influence the downshift characteristic magnetic force curve, an additional pressure spring  60  with a characteristic spring curve to be determined may be placed between the magnet elements  54  and  55 , as shown in FIG. 5, or the magnet element  55  may be replaced by the spring  60 . The particular advantage of the device  50  consists primarily of the fact that it is almost completely free of wear problems because of the use of magnetic forces. In any event, the most varying downshift characteristic magnetic force curves required to provide convenient operation of the automatic transmission may be created. 
     There has thus been shown and described a novel method and apparatus for producing downshift signals which fulfill all the objects and advantages sought therefor. Many changes, modifications, variations and other uses and applications of the subject invention will, however, become apparent to those skilled in the art after considering this specification and the accompanying drawings which disclose the preferred embodiments thereof. All such changes, modifications, variations and other uses and applications which do not depart from the spirit and scope of the invention are deemed to be covered by the invention, which is to be limited only by the claims which follow. If it is required to further influence the downshift characteristic magnetic force curve, an additional pressure spring  63  with a characteristic spring curve to be determined may be placed between the magnet elements  54  and  55 , as shown in FIG. 5, or the magnet element  55  may be replaced by the spring  63 . The particular advantage of the device  50  consists primarily of the fact that it is almost completely free of wear problems because of the use of magnetic forces. In any event, the most varying downshift characteristic magnetic force curves required to provide convenient operation of the automatic transmission may be created.