Accelerator pedal unit for a motor vehicle

Abstract

Accelerator pedal unit (1) for a motor vehicle, comprising a base body (10) on which an accelerator pedal (11) is rotatably mounted in a pivot joint (12) and which, starting from a rest position, is movable by actuation in an actuation direction (13), wherein a sensor unit (14) is accommodated in the base body (10), which sensor unit senses the position of the accelerator pedal (11) by means of a tapping element (15), and wherein a return spring (16) is provided, with which the accelerator pedal (11) is pretensioned into the starting position, characterized in that a force jump unit (17) with a spring-pretensioned stop element (18) is arranged on the accelerator pedal (11), and in that a movable counter-stop element (19) is provided, - that the counter-stop element (19) is movable into a stop position (I) in which, upon actuation of the accelerator pedal (11), the stop element (18) comes into contact with the counter-stop element (19) and moves into the force jump unit (17) by applying an additional force (F), - that the counter-stop element (19) is movable into a release position (II) in which, upon actuation of the accelerator pedal (11), the stop element (18) is freely movable in a movement range (20) and - that the counter-stop element (19) is movably received in the base body (10).

Description

The present invention relates to an accelerator pedal unit for a motor vehicle having a base body on which an accelerator pedal is held rotatably mounted in a rotary joint and which, starting from a rest position, can be moved in an actuating direction by actuation, wherein a sensor unit is held in the base body, which sensor unit senses the position of the accelerator pedal by means of a pick-off element, and wherein a restoring spring is provided, with which the accelerator pedal is prestressed into the initial position.PRIOR ARTWO 2011 / 141459 A1 describes a generic accelerator pedal unit for a motor vehicle having a base body on which an accelerator pedal is held rotatably mounted via a rotary joint. The accelerator pedal is prestressed into an initial position by a restoring spring, and if a driver of the motor vehicle operates the accelerator pedal, then in addition to the actuating force generated by the restoring spring, which increases substantially linearly with the movement of the accelerator pedal in the actuating direction, a further actuating force can be added, which can be adjusted with respect to the force value and with respect to the point of use of the additional force over the path in the actuating direction of the accelerator pedal.The design of the accelerator pedal unit is complicated and a lifting magnet is provided which must press the magnet plunger against a contact surface upon activation, in order to keep the contact between the magnet plunger and the contact surface permanent, however, an additional spring element is necessary. The contact surface is formed on a cam-like cam disk. If the lifting magnet is energized and the tappet presses against the contact surface, the resulting total actuating force of the accelerator pedal is characterized as a function of the energization and the time of activation of the lifting magnet with a jump in force.Such a jump in force can be used, for example, in hybrid vehicles in order to provide the driver of the motor vehicle with information as to when a switchover between an electric drive and a drive takes place by means of an internal combustion engine. In this case, vibrations or specific pulse sequences applied to the accelerator pedal are also described as force information, which can be generated by a corresponding actuation of the lifting magnet.However, in addition to the complex construction, further disadvantages of known accelerator pedal units are that long actuating paths are required for the application of an additional jump in force, and position detection along an axis of movement must be provided for the plunger, which can be moved with the lifting magnet, as a result of which the construction of the accelerator pedal unit is additionally of a more complex design.Furthermore, a similar pedal is disclosed in DE 10 2008 054 625 A1.DISCLOSURE OF THE INVENTIONThe object of the invention is to improve an accelerator pedal unit for a vehicle with a simple structure, with which an additional force for actuating the accelerator pedal can be generated. In particular, it is the object of the invention to be able to switch on and switch off the generation of the additional force with the simplest possible means.This object is achieved on the basis of an accelerator pedal unit according to the preamble of claim 1 in conjunction with the characterizing features. Advantageous further developments of the invention are specified in the dependent claims.To achieve the aforementioned object, the invention provides that a force-shifting unit with a spring-biased stop element is arranged on the accelerator pedal, and that a movable counterstop element is provided, wherein the counterstop element is movable in a stop position in which, when the accelerator pedal is operated, the stop element comes to rest against the counterstop element and, when an additional force is applied, enters the force-shifting unit, and wherein the counterstop element is movable into a release position in which, when the accelerator pedal is operated, the stop element is freely movable in a range of movement.The core of the invention is a device for a jump in force when an accelerator pedal is actuated that can be switched on and off, in that a counterstop element is moved in a simple manner between a stop position and a release position. If the additional restoring force of the accelerator pedal is switched on, the counterstop element is moved into the stop position, and if the additional restoring force is switched off again, the accelerator pedal unit according to the invention makes it possible to move the counterstop element into a release position.A particular advantage is that the feed force for the stop is independent of the force step height, which is achieved by an independent feed relative to the vertically extending plunger movement. As a result, the same actuator with low actuating forces can be used for different haptic signals and accelerator pedal designs.With the exception of an electrical movement unit for generating the movement of the counterstop element, the idea of the invention is based on a purely mechanical design of the activation and deactivation of the additional restoring force. The stop element is moved along its range of movement with the actuation of the accelerator pedal by the accelerator pedal being moved in the actuation direction, for example in the direction of the base body via the connection to the rotary joint. Due to the spring-biased property of the stop element and due to the arrangement of the force-shifting unit on the accelerator pedal, the additional restoring force is switched on in a mechanical manner to the restoring force which is already present by the restoring spring in a manner known per se. An electrical connection of the force-transmitting unit is dispensed with here, since the counterstop element can be moved into the movement range and also moved out of the latter again in a simple mechanical manner. If the counterstop element is in the release position, the force-jumping unit with the spring-biased stop element remains in a resting arrangement, and only when the counterstop element is moved into the range of movement of the stop element is the stop element activated by the spring-biased arrangement in or on the force-jumping unit and generates the additional restoring force.Advantageously, the counterstop element is movably accommodated in the base body. If the accelerator pedal is activated and moved in the actuating direction against the base body via the rotary joint, the force-transmitting unit can at least partially retract into a corresponding opening in the base body. By retracting the force-transmitting unit, the spring-biased stop element also reaches the base body and can interact with the counterstop element in the stop position.The core of the invention also comprises an arrangement of the force-transmitting unit in the base body, and at the same time the counterstop element can be arranged movably on the accelerator pedal. The mode of operation and thus the basic idea of the invention is thus fulfilled in the same way.According to a further advantageous embodiment of the invention, an actuator is provided with which the counterstop element is movable between the stop position and the release position. For example, the actuator comprises a lifting magnet arrangement, with which the movement of the counterstop element can be generated. The lifting magnet arrangement can be designed very simply, since the counterstop element only has to be switched back and forth between the stop position and the release position. For this purpose, the lifting magnet arrangement only has to be electrically switched on and off, and it is conceivable for the lifting magnet arrangement to have a bistable configuration, so that the counterstop element assumes a stable arrangement either in the stop position or in the release position without current being supplied. Of course, there is also the possibility of a monostable embodiment of the lifting magnet arrangement, for example in the release position.The actuator advantageously further comprises a spring unit which is arranged between the counterstop element and the lifting magnet arrangement. By means of the spring unit, a flexibility is installed in the connection between the counterstop element and the lifting magnet arrangement, which flexibility is used in particular to prevent jamming between the stop element and the counterstop element. For example, a state may occur in which the counterstop element is arranged in the release position, and by activation of the actuator, the counterstop element is transferred into the stop position, while, however, the stop element has already been moved into the movement range. Such an improper collision between the stop element and the counterstop element can possibly lead to jamming between the stop element and the counterstop element without the arrangement of the spring unit. The spring unit likewise prevents the situation in which the stop element strikes against the counterstop element, and the counterstop element is transferred into the release position by activation of the actuator. In this case, too, a negative interaction between the stop element and the counterstop element must be avoided, for which purpose the flexibility properties of the spring unit serve.For example, the stop element is formed by a plunger which is movable in its longitudinal direction. The plunger can come to rest with its end face against the counterstop element when the latter is in the stop position and when the plunger is moved into the range of movement by an actuation of the accelerator pedal. However, the stop element can alternatively also be designed in the form of a lever, a rocker, a rotary element or the like.According to a further embodiment of the invention, the force-transmitting unit has a housing in or on which the stop element is accommodated in a movably guided manner. The accelerator pedal has an actuation side, by means of which the driver generally actuates the accelerator pedal in the actuation direction with his foot. The force-transmitting unit is arranged on the side opposite the actuating side of the accelerator pedal and thus the rear side, wherein the housing of the force-transmitting unit can also be formed integrally with the accelerator pedal and in particular in the same material.With further advantage, the force-jumping unit comprises a spring element, with which the stop element is prestressed. The spring element and a part of the stop element, in particular a part of the plunger, can be accommodated with further advantage in the housing of the force-transmitting unit. The plunger can thus protrude over a partial length out of the housing of the force-transmitting unit, and if the end face of the plunger comes into contact with the counterstop element, the plunger is pressed along its longitudinal direction into the housing of the stop element under compression of the spring element.In a manner known per se, the tapping element taps off the position of the accelerator pedal in order to sense the latter. According to an advantageous arrangement which further simplifies the construction of the accelerator pedal unit, the tapping element can interact with the housing of the force-transmitting unit. In this way, in particular a transmission element between the accelerator pedal and the sensor unit with the tapping element is already replaced, in that the force-transmitting unit according to the invention is used for this purpose.Finally, according to yet another embodiment, the force-jumping unit has means with which a defined force-path profile of a retraction movement of the stop element into the housing of the force-jumping unit is generated. The means can be designed such that for the jump in force, in addition to the usual actuating force of the accelerator pedal, the additional restoring force begins at a specific point and rises sharply. The sudden increase in the total actuating force of the accelerator pedal is already achieved by the plunger being prestressed with a resting force via the spring unit in the housing of the force-jumping unit. If an operator actuates the accelerator pedal and the plunger comes into contact with the counterstop element, this high force already adds to the usual actuating force which is generated by the restoring spring. The means in the force step unit can, however, also be further developed in such a way that an initial force step falls again upon still further actuation of the accelerator pedal in the actuation direction.The actuator can be activated by the driver of the motor vehicle, for example by operating a control device in the motor vehicle, and the actuator can be designed for connection to a control device in the motor vehicle. If the driver of the motor vehicle wishes to provide information about a point of the accelerator pedal in the actuating direction, starting from or shortly before an internal combustion engine is switched on, the actuator can be activated and the counterstop element is transferred into the stop position. If the driver switches the actuator off again, since the driver does not wish to switch on the additional restoring force, the actuator is deactivated and the counterstop element is transferred into the release position.In particular, it is also possible to provide a sensor which detects whether the counterstop element is arranged in the stop position or in the release position. By detecting the position of the counterstop element, it is possible to output feedback to the control device, which increases the safety of the arrangement. The sensor is advantageously accommodated in the base body.PREFERRED EMBODIMENT OF THE INVENTIONFurther measures which improve the invention are described in more detail below together with the description of a preferred exemplary embodiment of the invention on the basis of the figures. It shows: FIG. 1 is a schematic side view of an accelerator pedal unit for a motor vehicle having the features of the invention, the accelerator pedal being shown in a starting position, FIG. 2 shows the view of the accelerator pedal unit with a force-transmitting unit and a counterstop element, wherein the counterstop element is arranged in a stop position and interacts with the force-transmitting unit, FIG. 3 is the view according to FIG. 2, wherein the counterstop element is arranged in a release position and does not interact with the force-transmitting unit, FIG. 4 shows a further exemplary embodiment of the accelerator pedal unit with a suspended arrangement of the accelerator pedal, wherein the counterstop element is shown advanced into the stop position, FIG. 5 shows the exemplary embodiment of the accelerator pedal unit according to FIG. 4, wherein the counterstop element is shown moved back into the release position, FIG. 6 is a diagram in which the pedal force is plotted against the pedal travel in the actuation direction, and wherein a force jump is applied to the actuation force, and FIG. 7 shows a further diagram in which the pedal force is plotted against the pedal travel in the actuation direction, and a force threshold is connected to the actuation force.FIG. 1 shows a schematic side view of the accelerator pedal unit 1 for a motor vehicle having a base body 10 on which an accelerator pedal 11 is rotatably mounted in a rotary joint 12. If the accelerator pedal 11 is actuated, it moves from the initial position shown along an actuation direction 13, wherein the accelerator pedal 11 is moved towards the base body 10. In this case, a sensor unit 14 is activated in a manner not shown in more detail via a pick-off element 15 which is designed in the manner of a lever, and the position of the accelerator pedal can be sensed along the actuating direction 13 via the sensor unit 14. An accelerator pedal signal is thus provided to a control unit, via which the driving speed of the motor vehicle can be predefined in a manner known per se.In order to prestress the accelerator pedal 11 in the direction of an initial position which the accelerator pedal 11 assumes when no actuation of the accelerator pedal 11 takes place, a restoring spring 16 is shown. The restoring spring 16 generates a pedal normal force which a driver of the motor vehicle experiences in a known manner, wherein the pedal normal force brings about a restoring force of the accelerator pedal 11 counter to the movement in the actuating direction 13.The accelerator pedal unit 1 has a force-transmitting unit 17 arranged on the accelerator pedal 11. The force-transmitting unit 17 is arranged on the rear side of the accelerator pedal 11, so that the force-transmitting unit 17 is located on a side opposite the actuating side 29 of the accelerator pedal 11. The force-transmitting unit 17 has a housing 26, and a stop element 18 is accommodated in the housing 26, and the stop element 18 is designed as a plunger 24, which protrudes predominantly from the housing 26 in a longitudinal direction 25.A spring element 27 is accommodated in the housing 26 of the force-transmitting unit 17, said spring element prestressing the plunger 24 in its longitudinal direction 25 in such a way that the plunger 24 is pressed out of the housing 26 as far as an end point.Furthermore, an end stop means 30 is located on the housing 26, which comes to rest against a rubber element 31 on the base body 10 when the accelerator pedal 11 has been actuated into a full load position.A counterstop element 19 is accommodated in the base body 10, and the counterstop element 19 can be moved back and forth between a stop position (see FIG. 2 in this regard) and a release position (see FIG. 3 in this regard) via an actuator 21, which is designed as a lifting magnet arrangement 22. The direction of movement 32 between the stop position and the release position is indicated by a double arrow and it can be seen that the direction of movement 32 runs perpendicular to the longitudinal direction 25 of the plunger 24.The actuator 21 comprises a spring unit 23 which is arranged between the counterstop element 19 and the lifting magnet arrangement 22. By means of the spring unit 23, a flexibility is generated in the connection between the counterstop element 19 and the lifting magnet arrangement 22, which flexibility is used in particular to prevent jamming between the stop element 18 and the counterstop element 19.FIG. 2 shows the accelerator pedal unit 1 with the force step unit 17 and with the counterstop element 19, which is shown in a stop position I. The accelerator pedal 11 is pressed down completely in the position shown, and the force-transmitting unit 17 dips into the base body 10 with the plunger 24. Due to the arrangement of the counterstop element 19 in the movement region 20 of the tappet 24, the end face 24 aof the tappet 24 comes into contact against the counterstop element 19 and is pressed into the housing 26 of the force-transmitting unit 17 upon further actuation of the accelerator pedal 11 in the actuation direction 13. Due to the compression of the spring element 27 (see FIG. 1 in this regard), the spring force of the spring element 27 adds to the spring force of the restoring spring 16, so that the driver experiences a jump in force when the accelerator pedal 11 is actuated. The beginning of the force jump occurs at the moment at which the end face 24 aof the plunger 16 abuts against the counterstop element 19. Since the tappet 24 is prestressed in the housing 26 of the force-transmitting unit 17, the actuating force of the accelerator pedal 11 rises spontaneously, since an additional restoring force is added to the restoring force generated by the restoring spring 16.The tapping element 15 is designed such that it abuts with one end side against the front side of the housing 26 of the force-transmitting unit 17. As a result, the pick-off element 15 is activated, so that the position of the accelerator pedal can be sensed simultaneously with the sensor unit 14. The full load position shown results from the end stop means 30 coming to rest against the rubber element 31. Further actuation of the accelerator pedal 11 in the actuation direction 13 is thus not possible.FIG. 3 shows the accelerator pedal unit 1 according to FIG. 2 with the counterstop element 19 which is in a release position II. As a result, the counterstop element 19 is not located in the movement region 20 of the plunger 24, and the plunger 24 remains in a position extended out of the housing 26 of the force-transmitting unit 17. Consequently, no additional restoring force is added to the restoring force of the accelerator pedal 11 counter to the actuating direction 13 generated in a known manner by the restoring spring 16.FIGS. 4 and 5 show a further exemplary embodiment of the accelerator pedal unit 1 for a motor vehicle having a base body 10, on which an accelerator pedal 11 is mounted suspended in a rotary joint 12. If the accelerator pedal 11 is actuated, it moves from an initial position along an actuation direction 13 into the full load position shown, wherein the accelerator pedal 11 pivots under the base body 10 due to the suspended arrangement. A sensor unit 14 is activated in a manner not shown in detail, and the position of the accelerator pedal 11 along the actuation direction 13 can be sensed via the sensor unit 14.In order to prestress the accelerator pedal 11 in the direction of an initial position which the accelerator pedal 11 assumes when no actuation of the accelerator pedal 11 takes place, a restoring spring 16 is shown. The restoring spring 16 generates a pedal normal force which a driver of the motor vehicle experiences in a known manner, wherein the pedal normal force brings about a restoring force of the accelerator pedal 11 counter to the movement in the actuating direction 13.The accelerator pedal unit 1 has a force-transmitting unit 17 arranged on the accelerator pedal 11. The force-transmitting unit 17 is arranged on the accelerator pedal 11 on the rear side or on the top side with respect to the actuating side 29, and said force-transmitting unit has a housing 26 in which a stop element 18 is accommodated, which is prestressed by a spring element 27 in a manner projecting out of the housing 26.A counterstop element 19 is movably accommodated in the base body 10, and the counterstop element 19 can be moved back and forth between a stop position I, shown in FIG. 4, and a release position II, shown in FIG. 5, via the actuator 21, which is designed as a lifting magnet arrangement 22.The actuator 21 comprises a spring unit 23 which is arranged between the counterstop element 19 and the lifting magnet arrangement 22. By means of the spring unit 23, a flexibility is generated in the connection between the counterstop element 19 and the lifting magnet arrangement 22, which flexibility is used in particular to prevent jamming between the stop element 18 and the counterstop element 19.In FIG. 4, the counterstop element 19 is in the stop position shown, and when the accelerator pedal 11 is actuated, the stop element 18 is planned to bear against the counterstop element 19.In FIG. 5, the counterstop element 19 is in the release position II, and when the accelerator pedal 11 is actuated, the stop element 18 does not plan for contact with the counterstop element 19, since the latter is led out of the movement region 20.FIG. 6 shows a diagram with which a pedal force P is plotted over a pedal travel s. The pedal normal force PNshown has a substantially linear course, wherein a parallel course for a path in the actuation direction 13 and counter to the actuation direction 13 is produced in a hysteresis-like manner.In an activation point 33 shown, the additional restoring force F is added to the pedal normal force PN, so that a sudden increase in the pedal force is perceptible to the driver of the motor vehicle.FIG. 7 finally shows a diagram with the pedal force P over the pedal travel s, wherein the additional restoring force F is shown as a force threshold, which increases abruptly starting at the activation point 33 and then slowly decays again with increasing pedal travel after the beginning force point. Such a course of the additional restoring force F is obtained by means 28 which can be present in the force-jumping unit 17. The pedal normal force PNshown has, as already described in connection with FIG. 4, an essentially linear course, wherein a parallel course for a path in the actuation direction 13 and against the actuation direction 13 arises in a hysteresis-like manner.List of reference characters1 Accelerator pedal unit 10 Base body 11 Accelerator pedal 12 Rotary joint 13 Actuating direction 14 Sensor unit 15 Pick-off element 16 Restoring spring 17 Force-transmitting unit 18 Stop element 19 Counterstop element 20 Movement region 21 Actuator 22 Lifting magnet arrangement 23 Spring unit 24 Plunger 24 aEnd side 25 Longitudinal direction 26 Housing 27 Spring element 28 Means 29 Actuating side 30 End stop means 31 Rubber element 32 Movement direction 33 Engagement point I Stop position II Release position P Pedal force PN Pedal normal force PZR Additional restoring force s Pedal travel

Claims

Accelerator pedal unit (1) for a motor vehicle, having a base body (10) on which an accelerator pedal (11) is held rotatably mounted in a rotary joint (12) and which, starting from a rest position, can be moved in an actuating direction (13) by an actuation, wherein a sensor unit (14) is held in the base body (10), which sensor unit senses the position of the accelerator pedal (11) by means of a pick-off element (15), and wherein a restoring spring (16) is provided, by means of which the accelerator pedal (11) is prestressed into the initial position, characterized in that a force-step unit (17) with a spring-prestressed stop element (18) is arranged on the accelerator pedal (11), and in that a movable counterstop element (19) is provided, - in that the counterstop element (19) can be moved into a stop position (I), in which, when the accelerator pedal (11) is actuated, the stop element (18) comes to rest against the counterstop element (19) and, when an additional force (F) is applied, enters the force-imparting unit (17), - the counterstop element (19) can be moved into a release position (II), in which, when the accelerator pedal (11) is actuated, the stop element (18) can be moved freely in a movement range (20), and - the counterstop element (19) is accommodated movably in the main body (10).Accelerator pedal unit (1) according to Claim 1, characterized in that an actuator (21) is provided, with which the counterstop element (19) is movable between the stop position (I) and the release position (II).Accelerator pedal unit (1) according to Claim 2, characterized in that the actuator (21) comprises a lifting magnet arrangement (22), with which the movement of the counterstop element (19) can be generated.Accelerator pedal unit (1) according to Claim 3, characterized in that the actuator (21) comprises a spring unit (23) which is arranged between the counterstop element (19) and the lifting magnet arrangement (22).Accelerator pedal unit (1) according to one of the preceding claims, characterized in that the stop element (18) is formed by a plunger (24) and is movable in a longitudinal direction (25), wherein the plunger (24) comes to bear with its end face (24a) against the counterstop element (19) when the latter is located in the stop position (I).Accelerator pedal unit (1) according to one of the preceding claims, characterized in that the force-transmitting unit (17) has a housing (26), in or on which the stop element (18) is accommodated in a movably guided manner.Accelerator pedal unit (1) according to Claim 6, characterized in that the force-transmitting unit (17) comprises a spring element (27), with which the stop element (18) is prestressed.Accelerator pedal unit (1) according to one of the preceding claims, characterized in that the tapping element (15) interacts with the housing (26) of the force-transmitting unit (17) in order to sense the position of the accelerator pedal (11).Accelerator pedal unit (1) according to one of the preceding claims, characterized in that the force-transmitting unit (17) has means (28) with which a defined force-path profile of a retraction movement of the stop element (18) into the housing (25) of the force-transmitting unit (17) is generated.

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