The present invention relates to an activation device for controlling the power of a vehicle drive having a foot pedal.
Such a device is known, for example, from German patent document DE 102 12 904 A1. In the disclosed device, the reaction force of the switching element, which has to be overcome for the switching element (which is acted on by the foot pedal) to switch, is generated by a spring which is integrated into the switching element.
In another known device according to German patent document DE 195 00 666 C2, an elastically deformable element, which has to be elastically deformed just before the foot pedal strikes the rigid stop, is provided outside the rigid stop. The switching element disclosed in this document has a position signal transmitter provided on the pivoting axis of the foot pedal. The position signal transmitter triggers a switching signal as soon as the foot pedal strikes the rigid stop. In contrast to the device according to the first-mentioned document, the switching element here is not activated by the foot pedal abutting against the switching element. The switching element here has a position signal transmitter which detects the angular position of the foot pedal on the axis of the foot pedal and activates the switching element at a predetermined angular position.
The switching element which the invention and the two abovementioned documents relate to is known in practice as a kickdown switching element, which is also referred to as a kickdown button.
In a device of the generic type according to German patent document DE 102 12 904 A1, the device is concerned with the problem of damping (i.e., reducing) the impacting noise of the foot pedal which impacts on the switching element. Such an impacting noise occurs in the known device if an operator activates the foot pedal extremely quickly for a kickdown acceleration.
This problem is solved in a device according to exemplary embodiments of the present invention which are based on the general idea of connecting a sprung damping element in front of the switching element on which the foot pedal directly impacts. In this context it is important for the function of such a damping element that the damping travel up to the time when the foot pedal abuts against the switching element remains exactly the same and does not experience any change during the operating time of a vehicle. This is important because the power control of the vehicle drive which has its origin in the foot pedal is based on precisely predefined angular positions of the foot pedal, or these angular positions have to be maintained unconditionally for the function to remain constant.
For example, damping elements such as felt layers or elastically deformable cushions are unsuitable, because they generally change their spring compression travel length over long operating times. Such changes are, on the one hand, conditioned by deformation of materials, and on the other hand, are dependent on wear of such elastic materials which is generally impossible to avoid.
In one exemplary embodiment of the present invention, when the damping spring reaches its maximum spring compression travel the damping spring dips completely into the surface of the switching element on which the foot pedal impacts with damping by the spring. As a result, the displacement of the switching element, which is dependent on the pivoting angle of the foot pedal and is brought about by the foot pedal which bears directly against the switching element, remains independent of the shape and position of the damping spring according to the invention.
The refinement of a spring according to the invention which is expediently composed of spring steel is particularly advantageously in the form of an angle at which the two angular webs include an obtuse angle between them. The angular web, which is not tightly secured to the switching element, protrudes obliquely from the impact face of the switching element for the foot pedal with such a design of the spring. The protruding angle can be, for example, approximately 30 degrees.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.
a-e show various foot pedal positions between a non-activated foot pedal and a foot pedal which is in a completely activated kickdown position.
An activation operation in order to control the power of a vehicle drive includes a foot pedal 1 which is pivotable and is secured to the vehicle, and a rigid stop 2 as a pivoting travel limiter for the foot pedal 1.
A switching element 3 is mounted ahead of the rigid stop 2 within the pivoting travel of the foot pedal 1. In this context, this switching element 3 is mounted in a pliant fashion within the rigid stop 2, specifically in such a way that when the foot pedal 1 impacts on the rigid stop 2 the switching element 3 is pushed into the interior of the rigid stop 2 by an exactly predefined amount of travel. In practice, the switching element 3 is usually referred to as a kickdown button. This switching element 3 can be embodied in a known, customary fashion with kickdown buttons.
A damping spring 4 is provided within the impact face of the switching element 3 for the stop of the foot pedal 1.
As is apparent from
The spring 4 is attached in the switching element 3 by virtue of the fact that a first of the two angular webs is secured in it, in which case the first angular web engages completely in the switching element 3. The second angular web projects obliquely from the impact face of the switching element 1 and in doing so has, for example, an angle of inclination of approximately 30 degrees.
In the switching element 3, the spring 4 is mounted within a groove 5 in such a way that the sprung angular web, which protrudes in an inclined fashion, can be completely accommodated in this groove 5 when the foot pedal 1 abuts completely. Completely accommodated means that when the foot pedal 1 abuts completely against the switching element 3 only the adjoining surfaces of the switching element 3 and the foot pedal 1 are in “inelastic contact” with one another.
The function of the device according to the invention is, with particular reference to
If the foot pedal 1 is depressed (i.e., pivoted) quickly by an operator in the direction of the rigid stop 2 for a kickdown acceleration, the foot pedal 1 impacts on the damping spring 4 provided on the impact face of the switching element 3 before it impacts directly on the impact face (
The foregoing disclosure has been set forth merely to illustrate the invention and is not intended to be limiting. Since modifications of the disclosed embodiments incorporating the spirit and substance of the invention may occur to persons skilled in the art, the invention should be construed to include everything within the scope of the appended claims and equivalents thereof.
Number | Date | Country | Kind |
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10-2004-051-888.2 | Oct 2004 | DE | national |
This application is a national stage of PCT International Application No. PCT/EP2005/011177, filed Oct. 18, 2005, which claims priority under 35 U.S.C. § 119 to German Patent Application No. 10 2004 051 888.2, filed Oct. 26, 2004, the entire disclosures of which are herein expressly incorporated by reference.
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/EP05/11177 | 10/18/2005 | WO | 00 | 2/27/2008 |