Abstract:
Disclosed in an accelerator pedal module in which a two-point calibration is performed, so that the idle travel distances are substantially shorter than could be chosen in the previously known accelerator pedal module. In particular, the sensor may first be calibrated in a so-called kick-down angle position, and the position of repose of the pedal lever then be set via an adjusting screw. The accelerator pedal module is intended for controlling the power of a driving machine of a motor vehicle.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a 35 USC 371 application of PCT/DE 00/02831 filed on Aug. 18, 2000. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention is directed to an accelerator pedal module more particularly to an accelerator pedal module for a motor vehicle. 
     2. Description of the Prior Art 
     For controlling the power of a driving engine or motor of a motor vehicle, the demands of the motor vehicle driver are transmitted to the driving machine from a pedal lever, disposed within range of the motor vehicle driver, by means of electric lines and via a controller. To that end, a sensor is provided that measures the position of the pedal lever. Measured values from the sensor, after suitable processing, are transmitted to the driving machine by the controller. A kick-down mechanism and an electric switch are often provided as well. 
     The sensor of the accelerator pedal module is intended, at a certain position of the pedal lever, to furnish an electrical signal at a precisely predetermined level. To that end, the sensor is adapted in a certain position of the pedal lever. In the accelerator pedal module shown in International Patent Disclosure WO97/12781 and in German Patent Disclosure DE 195 36 606 A1, this is done by rotating the sensor housing, in a certain position of the pedal lever, far enough that the electrical signal output by the sensor is located within a predetermined, narrow tolerance band. Upon an actuation of the pedal lever, the electrical signal output by the sensor then changes, so that the controller can detect the position of the pedal lever at that time. 
     Upon an actuation of the pedal lever between the position of repose of the pedal lever and the end position of the pedal lever, there is a so-called kick-down angle position, in which the restoring force exerted on the pedal lever rises abruptly. The kick-down angle position is located shortly before the end position of the pedal lever. An electric switch is provided on the accelerator pedal module. The electric switch typically serves to switch over a gear of the motor vehicle. The electric switch is switched over by the pedal lever whenever the pedal lever is located between the kick-down angle position and the end position. 
     Because the slope of the electrical signal output by the sensor is unavoidably affected by tolerances as a function of the angle position of the pedal lever, and because the switching point of the electric switch is also not entirely free of tolerance, and since furthermore the mechanism of the accelerator pedal module has tolerances with regard to the attainable angle positions, the switching path between the kick-down angle position and the angle position, at which the electric switch switches over, must be relatively long, in the known accelerator pedal module. The kick-down switching path between the kick-down angle position and the end position of the pedal lever is also fairly long in the known accelerator pedal module, for the tolerance reasons given. Another disadvantage is that because of tolerances, the fact that the electrical signal of the sensor upon reaching the kick-down angle position is relatively widely scattered must be accepted into the bargain. 
     As a result, the paths for actuating the pedal lever must be kept relatively long overall, and the scattering of the electrical signal of the sensor in the kick-down angle position must be taken into account by suitable design of the electric controller, for instance by means of a suitable control unit. 
     SUMMARY OF THE INVENTION 
     The accelerator pedal module embodied according to the invention has the advantage over the prior art that, largely independently of production-dictated tolerances in the electrical signal of the sensor, a very precise electrical signal of the sensor can be attained that is dependent on the particular position of the pedal lever at the time. In particular, it can be attained that in both the position of repose of the pedal lever and the kick-down angle position of the pedal lever, the electrical signal of the sensor is within very close tolerances. A further advantage is that the switching path between the kick-down angle position and the switchover of the electric switch can be kept desirably quite short, and the pivot angle between the kick-down angleposition of the pedal lever and the end position of the pedal lever can also be kept fairly short. As a result, the advantage is obtained that the driver operating the pedal lever has the feeling of precise control of the power of the driving machine between the position of repose of the pedal lever and the kick-down angle position of the pedal lever, and the switching path and the pivot angle between the kick-down angle position and the end position of the pedal lever can be kept fairly short. A long switching path and a long pivot angle between the kick-down angle position and the end position would in fact be perceived as a fairly unpleasant idle travel by the driver. Since only short idle travel distances for the pedal lever overall are required, the advantage is obtained that the accelerator pedal module can be made relatively small in size overall, and that the available installation space in the passenger compartment for actuating the pedal lever is fairly small. 
     By the provisions recited in the dependent claims, advantageous refinements of and improvements to the accelerator pedal module defined by the main claim are possible. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The foregoing and other features of the invention will be apparent from the detailed description contained below, taken with the drawings, in which: 
     FIG. 1 is a side view of a first exemplary embodiment of an accelerator pedal module; 
     FIG. 2, partly in section, is a side view of the first exemplary embodiment with the sensor removed; and 
     FIG. 3, partly in section, is a side view with the sensor removed from a further exemplary embodiment of the accelerator pedal module. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The accelerator pedal module embodied according to the invention can be used to control various driving machines. By way of example, the driving machine is an Otto engine, whose throttle valve is adjusted with a control motor. In that case, the accelerator pedal module is used to output electrical signals, which are delivered to the control motor that adjusts the throttle valve. However, by way of example, the driving machine can also be a Diesel engine or an electric motor, and in these cases as well, electrical signals originate at the accelerator pedal module and, suitably reshaped, control the power of the driving machine. 
     The accelerator pedal module is preferably secured to a vehicle part of the motor vehicle directly within action range of the motor vehicle driver. The pedal lever of the accelerator pedal module is often also called a gas pedal. 
     FIGS. 1 and 2 show a side view of a preferably selected, especially advantageous exemplary embodiment; in FIG. 2, for the sake of greater simplicity, the sensor has been omitted, and both the retaining structure that serves as a housing and the pedal lever of the accelerator pedal module are shown partly in section. 
     In all the drawings, identical or identically functioning parts are identified by the same reference numerals. Unless otherwise noted or shown in the drawings, what is said and shown in conjunction with one of the drawing figures applies to the other exemplary embodiments as well. Unless otherwise stated in the explanation, details of the various exemplary embodiments can be combined with one another. 
     FIGS. 1 and 2 show an accelerator pedal module  1 . The accelerator pedal module  1  includes a retaining structure  2 , a pedal lever  3 , a sensor  5 , an electric switch  6 , a kick-down mechanism  7 , a restoring spring assembly  8 , and a pivot bearing  9 . 
     The retaining structure  2  is preferably secured directly in the range of the foot of a motor vehicle driver to a vehicle part  12  of a motor vehicle, shown symbolically by shading in the drawings. The pedal lever  3  is preferably actuated directly by the driver&#39;s foot. However, it is also possible to connect a separate gas pedal pivotably to the pedal lever  3  via a simple rod linkage. 
     The retaining structure  2  carries the pedal lever  3 . Via the pivot bearing  9 , the pedal lever  3  is supported pivotably relative to the retaining structure  2 . The sensor  5  senses the position of the pedal lever  3  at any given time and furnishes an electrical signal, corresponding to the position of the pedal lever  3 , to a controller, not shown, via electric lines, also not shown in drawings. 
     The pedal lever  3  is adjustable between position of repose R and an end position E. Between the position of repose R and the end position E, there is a kick-down angle position KD. The pedal lever  3  reaches the kick-down angle position KD shortly before it reaches its end position E. Between the kick-down angle position KD and the end position E, there is also a particular, definable switching position S. 
     The electric switch  6  shown symbolically in FIG. 2 is integrated with the kick-down mechanism  7 . In the structurally definable switching position S of the pedal lever  3 , the electric switch  6  generates a signal to the controller, not shown, via the terminal pins  6   a  and  6   b  leading out of the kick-down mechanism  7  and via an electric line, not shown. By way of example, the switch  6  is a so-called opener or a so-called closer. 
     If the pedal lever  3  is not actuated, then the restoring spring assembly  8  puts the pedal lever  3  in the position of repose R. If sufficiently great force is exerted on a pedal plate  3   a  provided at the end of the pedal lever  3 , then the pedal lever  3  can be adjusted counter to the restoring force of the restoring spring assembly  8  as far as the end position E. 
     The drawings show the pedal lever  3  in its position of repose R in solid lines. Part of the pedal lever  3  is also shown in dashed lines in the kick-down angle position KD; short dashed lines also indicate the end position E of the pedal lever  3 , and the lower end of the pedal plate  3   a  is also furthermore shown symbolically, while the pedal lever  3  is in the switching position S. For the sake of greater simplicity, the pedal lever  3  is shown only in part in the kick-down angle position KD, the switching position S, and the end position E. An arrow marked R points to the lower end, in the position of repose R, of the pedal plate  3   a ; an arrow marked KD points to the lower end, in the kick-down angle position KD, of the pedal plate  3   a ; an arrow marked S points to the lower end, in the switching position S, of the pedal plate  3   a ; and an arrow marked E points to the lower end, in the end position E, of the pedal plate  3   a.    
     The sensor  5  is flanged to the retaining structure  2 , which acts as a housing or as a bearing block. The sensor  5  has a sensor housing  5   a , onto which two laterally protruding flanges  5   b  are formed. One oblong slot  5   c  is provided in each of the flanges  5   b . The sensor  5  is built onto the retaining structure  2  in such a way that the sensor  5  is rotatable about a sensor lever pivot axis  5   d  relative to the retaining structure  2 . To that end, a cylindrical protrusion is formed, for instance onto the sensor housing  5   a , concentrically to the sensor lever pivot axis  5   d , and the protrusion engages a cylindrical bore provided in the retaining structure  2 . The sensor lever pivot axis  5   d  extends perpendicular to the plane of the drawing in FIGS. 1 and 2; in FIG. 1, the sensor lever pivot axis  5   d  is indicated in symbolic form as an intersection point of two short lines perpendicular to one another. The sensor  5  has a sensor shaft  5   h  and a sensor lever  5   e . The sensor shaft  5   h  extends concentrically to the sensor lever pivot axis  5   d . The sensor shaft  5   h  penetrates the sensor housing  5   a  on the side of the sensor housing  5   a  that is remote from the side that is visible in FIG.  1 . The sensor level  5   e  is secured in a manner fixed against relative rotation on the end of the sensor shaft  5   h  toward the pedal lever  3  and protruding out of the sensor housing  5   a.    
     The sensor  5  is flanged to the retaining structure  2 , which acts as a housing or as a bearing block. The sensor  5  has a sensor housing  5   a , onto which two laterally protruding flanges  5   b  are formed. One oblong slot  5   c  is provided in each of the flanges  5   b . The sensor  5  is built onto the retaining structure  2  in such a way that the sensor  5  is rotatable about a sensor lever pivot axis  5   d  relative to the retaining structure  2 . To that end, a cylindrical protrusion is formed, for instance onto the sensor housing  5   a , concentrically to the sensor lever pivot axis  5   d , and the protrusion engages a cylindrical bore provided in the retaining structure  2 . The sensor lever pivot axis  5   d  extends perpendicular to the plane of the drawing in FIGS. 1 and 2; in FIG. 1, the sensor lever pivot axis  5   d  is indicated in symbolic form as an intersection point of two short lines perpendicular to one another. The sensor  5  has a sensor shaft  5   h  and a sensor lever  5   e . The sensor shaft  5   h  extends concentrically to the sensor lever pivot axis  5   d . The sensor shaft  5   h  penetrates the sensor housing  5   a  on the side of the sensor housing  5   a  that is remote from the side that is visible in FIG.  1 . The sensor lever  5   e  is secured in a manner fixed against relative rotation on the end of the sensor shaft  5   h  toward the pedal lever  3  and protruding out of the sensor housing  5   a.    
     Upon an actuation of the pedal lever  3 , the pin  3   b  of the pedal lever  3  moves about the pivot axis of the pivot bearing  9 . Since the pedal lever  3 , via the pin  3   b , is in engagement with the sensor lever  5   e  of the sensor  5 , an actuation of the pedal lever  3  leads to a correspondingly stepped-up pivoting motion of the sensor lever  5   e  about the sensor lever pivot axis  5   d , which in turn causes a corresponding change in the electrical signal of the sensor  5 . 
     The kick-down mechanism  7  has a housing  7   a . The housing  7   a  is built into the retaining structure  2 . Inside the housing  7   a , there is an axially displaceable pin  7   b  that can be pressed in resiliently. On the face end of the pin  7   b  toward the pedal lever  3 , a kick-down stop  7   k  is provided. There is a counterpart stop  3   k  on the pedal lever  3 . 
     On the retaining structure  2 , there is an end stop  2   e , and there is a counterpart end stop  3   e  on the pedal lever  3 . Upon actuation of the pedal lever  3  until it reaches the end position E, the counterpart end stop  3   e  of the pedal lever  3  comes to rest on the end stop  2   e  of the retaining structure  2 . As a result, the maximum actuatable pivot angle of the pedal lever  3  is limited, and the end position E is defined. 
     Upon an actuation of the pedal lever  3  beginning at the position of repose R, the counterpart stop  3   k  provided on the pedal lever  3  comes to rest, in an intermediate position, on the kick-down stop  7   k . The angle position at which the counterpart stop  3   k  comes to rest on the kick-down stop  7   k  is called the kick-down angle position KD. If the pedal lever  3  is actuated farther, past the kick-down angle position KD, then the resiliently prestressed pin  7   b  is pressed into the housing  7   a . As a result, when the kick-down angle position KD is exceeded, the restoring force acting on the pedal lever  3  rises abruptly. 
     While the sensor lever  5   e  is in engagement with the pedal lever  3  via the pin  3   b , the entire sensor housing  5   a  can be pivoted about the sensor lever pivot axis  5   d . The result is a rotational guidance of the sensor housing  5   a  relative to the retaining structure  2 , via the protrusion that is formed onto the sensor housing  5   a  and engages the cylindrical bore provided in the retaining structure  2 . By means of rotating the sensor housing  5   a , calibration of the sensor  5  can be done. The sensor  5  can be rotated about the sensor lever pivot axis  5   d  so far that the desired, predetermined electrical signal corresponding to the position of the pedal lever  3  at the time is output at the plug connection  5   g  of the sensor  5 . 
     Two plastic pins  2   a  are formed onto the retaining structure  2 . The pins  2   a  protrude through the oblong slots  5   c  of the sensor  5 . The oblong slots  5   c  extend concentrically to the sensor lever pivot axis  5   d . For calibration of the sensor  5 , the sensor housing  5   a  can be rotated about the sensor lever pivot axis  5   d  so far that the pins  2   a  of the retaining structure  2  abut the ends of the oblong slots  5   c  of the sensor  5 . This calibration takes place while the pedal lever  3  is in a first angle position. In the first angle position, the sensor  5  is calibrated, by rotation of the sensor housing  5   a , in such a way that the signal output by the sensor  5  corresponds to a desired, predeterminable, first electrical setting signal. 
     It is especially proposed that the kick-down angle position KD of the pedal lever  3  be provided as the first angle position for setting the first electrical setting signal. As a result, especially low tolerances are obtained overall. However, it is also possible to provide the end position E of the pedal lever  3  as the first angle position for setting the first electrical setting signal. 
     After the calibration of the first electrical setting signal of the sensor  5 , the pins  2   a  are deformed, by axial pressure and optionally by supplying heat, far enough that a permanent, immovable clamping connection is created between the pins  2   a  of the retaining structure  2  and the flanges  5   b  of the sensor  5 . Even after a long time in operation, this assures a fixed association between the position of the pedal lever  3  and the electrical signal output by the sensor  5 . 
     On the retaining structure  2 , there is a repose stop  2   r . A counterpart repose stop  3   r  is provided on the pedal lever  3 . The repose stop  2   r  forms an adjustable stop  15 . An adjusting element  14  is provided on the retaining structure  2 . To keep the production cost low, the adjusting element  14  is an adjusting screw  14   a  screwed into the retaining structure  2 . The repose stop  2   r  that forms the adjustable stop  15  in this exemplary embodiment is located on the end of the adjusting screw  14   a  toward the counterpart repose stop  3   r . As FIGS. 1 and 2 show, the repose stop  2   r  and thus the adjustable stop  15  of the adjusting element  14  are assigned, via the retaining structure  2 , to the vehicle part  12  of the motor vehicle. Correspondingly, the counterpart repose stop  3   r  is assigned to the pivotable pedal lever  3 . 
     Beginning at the position of repose R, the pedal lever  3  passes through the kick-down angle position KD and then the switching position S to reach the end position E. For reasons of comfort and because of the required installation space, the pivot angle between the kick-down angle position KD and the end position E should be as small as possible, and assurance should also be provided that the electrically usable range of the sensor  5  is in fact also fully exploited. Since the pivot angle between the kick-down angle position KD and the end position E, and thus also the pivot angle between the switching position S and the end position E, should be quite small, it is proposed that a calibration be performed in two positions of the pedal lever  3 . Besides the calibration in the first angle position to the first electrical setting signal, the accelerator pedal module  1  is also calibrated in a second angle position of the pedal lever  3  to a desired, predetermined, second electrical setting signal. 
     The setting of the predeterminable first electrical setting signal is preferably done whenever the pedal lever  3  is in its kick-down angle position KD. During the setting of the first electrical setting signal, the pedal lever  3  is acted upon by a force that suffices to keep the counterpart stop  3   k  of the pedal lever  3  in contact with the kick-down stop  7   k , but without pressing the pin  7   b  inward. To set the first electrical setting signal, while the pedal lever  3  is in the kick-down angle position KD, the sensor housing  5   a  is rotated relative to the retaining structure  2  far enough that the desired first electrical setting signal is output by the sensor  5  at the plug connection  5   g . Next, the sensor  5  is permanently fixed relative to the retaining structure  2  with the aid of the pins  2   a , while the pedal lever  3  is held in the is kick-down angle position KD. 
     In the unloaded state, the restoring spring assembly  8  actuates the pedal lever  3  to its position of repose R. During the setting of the desired, predetermined, second electrical setting signal, the pedal plate  3   a  is not loaded. As a result, the pedal lever  3  is in its position of repose R, and the counterpart repose stop  3   r  rests on the adjustable stop  15 . While the pedal lever  3  is in the position of repose R, the adjusting screw  14   a  is rotated at the wrench face  14   c . By rotation at the adjusting screw  14   a , the adjustable stop  15  is adjusted, and as a result the pedal lever  3  is pivoted somewhat. This causes the electrical signal output by the sensor  5  to change, while the pedal lever  3  is in the non-actuated position of repose R. Rotation is performed at the adjusting screw  14   a  of the adjusting element  14  long enough that the sensor  5  outputs the desired, predeterminable, second electrical setting signal. Thus by rotation of the adjusting screw  14   a  acting as an adjusting element  14 , the desired second electrical setting signal is calibrated. 
     The wrench face  14   c  of the adjusting screw  14   a  is accessible from the side of the retaining structure  2  oriented toward the vehicle part  12 . This makes it possible for the adjusting element  14  to be set even after the accelerator pedal module  1  has been completely assembled. Since the wrench face  14   c  of the adjusting screw  14   a  is no longer accessible once the accelerator pedal module  1  has been mounted on the vehicle part  12 , unintended adjustment of the adjusting element  14  is prevented with certainty. 
     As the preferably selected exemplary embodiment described in conjunction with the drawings shows, it is proposed that a first electrical setting signal and in addition a predeterminable second electrical setting signal be calibrated. It is especially proposed that the first electrical setting signal be set while the pedal lever  3  is in its actuated kick-down angle position KD; however, it is also possible to set the first electrical setting signal while the pedal lever  3  is in its fully actuated end position E. It is further proposed that the predeterminable second electrical setting signal be set while the pedal lever  3  is in the unactuated position of repose R. The double calibration can be done especially simply and without major engineering effort or expense by providing that the first electrical setting signal is effected by pivoting the sensor  5  about the sensor lever pivot axis  5   d , and the setting of the second electrical setting signal is done by calibrating the angular position of the pedal lever  3  in the position of repose R such that in the position of repose R, the predeterminable electrical setting signal occurs, and this second setting takes place by way of the adjustable stop  15  provided between the pedal lever  3  and the retaining structure  2 . 
     In the preferably selected exemplary embodiment, the electric switch  6  is integrated with the kick-down mechanism  7 . Instead of the electric switch  6  in the kick-down mechanism  7 , or in addition to the electric switch  6  in the kick-down mechanism  7 , an electric switch  6 ′ can selectively also be provided inside the sensor  5 . The alternative switch  6 ′ is shown symbolically by dashed lines in FIG.  1 . The switch  6 ′ in the sensor  5  is constructed such that when the pedal lever  3  exceeds the switching position S, the electric switch  6 ′ provided in the sensor  5  switches over. 
     Depending on the type of motor vehicle and in particular on the embodiment of the electric controller, it is possible to dispense with both the switch  6  and the switch  6 ′. The electric controller can also be constructed such that when the pedal lever  3  is in the switching position S, the downstream controller sends a corresponding electrical switching signal to a component of the motor vehicle that is to be switched, doing so on the basis of electrical values output by the sensor  5  and ascertained for instance via the potentiometer built into the sensor  5 . 
     FIG. 3 shows a further preferably selected, especially advantageous exemplary embodiment. 
     Since in the second exemplary embodiment the sensor  5  and the pivotable connection of the sensor  5  to the retaining structure  2  and to the pedal lever  3  are designed identically to the first exemplary embodiment, the sensor  5  has not been shown in FIG. 3 for the sake of greater simplicity in the second exemplary embodiment, and parts of the retaining structure  2  and of the pedal lever  3  are also shown in section for the sake of greater simplicity. 
     In the exemplary embodiment shown in FIG. 3, the housing  7   a  of the kick-down mechanism  7  is built into the pedal lever  3 . Thus in this exemplary embodiment, the kick-down stop  7   k  is assigned to the pedal lever  3 , and a counterpart stop  2   k  to the kick-down stop  7   k  is provided on the retaining structure  2 . Upon actuation of the pedal lever  3  to the kick-down angle position KD, the kick-down stop  7   k  contacts the counterpart stop  2   k . If the pedal lever  3  is actuated past the kick-down angle position KD, then the counterpart stop  2   k  presses the pin  7   b  into the housing  7   a , until the counterpart end stop  3   e  rests on the end stop  2   e , thereby defining both the end position E and hence the maximum pivotability of the pedal lever  3 . 
     The adjusting screw  14   a  that forms the adjusting element  14  is screwed into the pedal lever  3 , in the exemplary embodiment shown in FIG.  3 . The repose stop  2   r  is located on the retaining structure  2 , and the counterpart repose stop  3   r  is located on the face end of the adjusting screw  14   a  toward the repose stop  2   r . In this exemplary embodiment, the counterpart repose stop  3   r  forms the adjustable stop  15  of the adjusting element  14 . That is, in this example the adjustable stop  15  is assigned to the pedal lever  3 . When the pedal lever  3  is in the position of repose R, then the counterpart repose stop  3   r  of the pedal lever  3  rests on the repose stop  2   r  of the retaining structure  2 . Also in this exemplary embodiment, the setting of the second setting signal can be done in the unactuated position of repose R, by adjustment of the adjusting element  14 . 
     An opening  16  is provided in the retaining structure  2 . Through the opening  16 , the adjusting screw  14   a  can be rotated with a wrench, via the wrench face  14   c . After the calibration, the opening  6  is closed with a stopper  18 . 
     To avoid an electrical connection line that is constantly in motion, it is proposed that in the exemplary embodiment shown in FIG. 3, no electric switch be provided in the kick-down mechanism  7 , but instead, that the electric switch  6 ′ in the sensor  5  be used, as represented symbolically by dashed lines in FIG.  1 . 
     The accelerator pedal module  1  can also be modified, for instance in such a way that the kick-down mechanism  7  is assigned to the retaining structure  2 , while the adjusting element  14  with the adjustable stop  15  is provided on the pedal lever  3 . A further example of modification is possible in such a way that the kick-down mechanism  7  is built into the pedal lever  3 , and the adjusting screw  14   a  that forms the adjusting element  14  and has the adjustable stop  15  is provided on the retaining structure  2 . 
     The foregoing relates to preferred exemplary of embodiments of the invention, it being understood that other variants and embodiments thereof are possible within the spirit and scope of the invention, the latter being defined by the appended claims.