The accelerator pedal, also known as the accelerator pedal or accelerator pedal (only in the German standard DIN 73001), is a control element of motor vehicles (motor vehicles) with which the mean pressure and thus the engine torque can be regulated. It is located in the footwell of the driver’s seat area and is usually operated with the right foot. On motorcycles, in some light vehicles, and motor vehicles individually modified for people with physical disabilities, a throttle twist grip or hand throttle control is used in place of the accelerator pedal. Drivers of short stature often use pedal raisers.
The term “accelerator pedal” originates from the time of the motor vehicle, when the corresponding pedal was used to regulate the air flow through the carburetor, through a throttle valve or slider by means of a cable or linkage. With the introduction of the diesel engine, fuel injection and the electric car, the term has lost its concrete meaning.
Types and designs
A distinction is made between two designs. The upright accelerator pedal is attached to the car floor with a hinge, and is usually high and narrow. The associated linkage can lead either downwards into the car floor (rear engine) or forwards upwards (through the bulkhead) into the engine compartment
The smaller hanging accelerator pedal is attached to a lever that always extends from the front at the top of the footwell, and has its pivot point at the top. Hanging pedals are most commonly used in passenger cars; upright pedals are most common in sports cars. In both designs, the pedal can be made of metal or plastic, and often the top has longitudinal grooves to prevent the foot from slipping off. Metal pedals with holes are common in racing, they are also offered as retrofit kits for ordinary passenger cars
For powerboats, upright throttle pedals with a raised edge are used to provide sufficient lateral support for the foot even when the boat is moving. Especially for built-in and large outboard engines, fixed cable-operated hand levers are used, which also allow direction reversal in reversing gearboxes. For small outboard engines, the “throttle” is often done directly on the engine
In the past, attempts were made to combine the accelerator pedal with the brake pedal into one control lever in order to relieve the driver and to cope with the increasing traffic density. One of the inventors was G. Peiseler from Leipzig with the Peiseler pedal. An Opel Kadett retrofitted in this way was approved by the KTA of the GDR and was in service in Berlin. The biggest argument for this design is still today the clearly shortened braking distance, since the foot does not need to be moved first and a shock experience can be converted immediately into the stretching of the leg. For undocumented reasons, the accelerator-brake pedal has not been able to establish itself in internal combustion engines to this day.
Electronic accelerator pedal (e-gas pedal)
In newer motor vehicles, the accelerator pedal no longer acts mechanically-directly via linkage or cable, but via the engine control unit on throttle elements (in the case of the petrol engine) or on the injection system (in the case of the diesel engine). The sensor that informs the control unit of the driver’s throttle request is called a pedal value sensor and is usually a double potentiometer for safety reasons. In newer vehicles, lower-wear but more expensive sensor principles, e.g. using Hall elements, are also used instead of potentiometers. The sensor transmits the accelerator pedal position analogously in the form of two voltage values to the control unit. In the case of CAN bus networking, digital setpoint signals are also implemented.
The traction control system can thus reduce the engine power relatively easily.
In addition, force feedback solutions are also possible, which support an energy-saving mode of operation by “resisting” inefficient operating modes or states, as it were.
For people who can no longer operate the accelerator with their right leg due to paralysis, stiffening or an amputation, this is often moved to the left next to the brake pedal. In this case, the left leg is used to operate the accelerator and brake pedals, while an automatic transmission instead of a manual transmission makes clutch operation unnecessary
The accelerator pedal relocation is available in different structural designs, just as different is the retention of the original pedal and/or the quick changeover to “right throttle” or “left throttle” when changing drivers
The easiest way is to convert the accelerator pedal to an extended axle shaft or on a side lever extension to the left without replacement on the right side. For the accompanying retention of the original pedal, there are numerous mechanical solutions with foldable, reversible or removable pedals, as well as electrically reversible double pedal solutions.
Alternative hand throttle
An alternative solution to motor vehicle conversion for physically disabled people is offered by converting to a hand throttle control. The hand throttle is also used on motorcycles, quads, motorboats and tractors, either regularly or as additional equipment, without the need for a physical disability-related adaptation.
In some cases, both when relocating the pedal and when installing a hand throttle control, there is a need for a pedal lock which prevents accidental actuation by contact with the inactive leg or the prosthetic leg on the original pedal which is still present but is not currently required. In the simple case, the pedal lock or “foot throttle lock” consists of a fixed or removable metal cover.
- Current pedal
- Hans-Hermann Braess, Ulrich Seiffert: Vieweg Handbook of Automotive Engineering. 2. Auflage, Friedrich Vieweg & Sohn Verlagsgesellschaft mbH, Braunschweig/Wiesbaden, 2001, ISBN 3-528-13114-4
- Kai Borgeest: Elektronik in der Fahrzeugtechnik. 1. Edition, Friedr. Vieweg & Sohn Verlag, Wiesbaden, 2007, ISBN 978-3-8348-0207-1
- Shortening the stopping distance with the aid of the Peiseler pedal. In: Kraftfahrzeugtechnik 3/1956, pp. 93-95.
- Combined brake/gas pedal (Peiseler pedal). In: Kraftfahrzeugtechnik 5/1960, pp. 177-178.