JPH1138U - Apparatus for detecting gear engagement in vehicle gearbox - Google Patents

Abstract

(57) [Problem] To provide a device capable of avoiding undesired re-switching-on of a vehicle speed limiting device and maintaining comfortable running characteristics. SOLUTION: A delay circuit is provided for delaying re-switching-on of the vehicle speed limiting device after the output signal stops appearing.

Description

[Detailed description of the invention]

[0001]

[Technical field to which the invention belongs]

 The present invention relates to a device for detecting the presence or absence of a gear engagement state in a gear box of a mechanically propelled vehicle, and a device for calculating a ratio between an engine rotation speed and a vehicle speed. A further device downstream of the device for monitoring said ratio to form an output signal indicating the occurrence of a change in said ratio, and a vehicle speed limiting device for a vehicle, for example a vehicle equipped with a diesel engine. Gear engagement in a vehicle gearbox, wherein the vehicle speed limiting device is provided with an output signal of the further device to release the vehicle speed limiting mode when no gear engagement has occurred. To a detection device.

[0002]

[Prior art]

 In the case of vehicles (vehicles) equipped with a travel speed limiting device, it is important to be able to confirm whether the gears are engaged. When the vehicle exceeds the permitted speed, the speed limiter acts on the EDC to reduce the amount of fuel injected to zero or to the amount of idling for the lowest idling speed. Restrict it. If the gearbox was neutral at that time, the driver would have no control over the engine speed, making it impossible for him to engage the gearbox with the desired gear. If the gearbox releases the gears and becomes neutral when the vehicle speed becomes too high, or if the driver releases the clutch when the vehicle speed is above the maximum allowed, no gears will be engaged. The output signal generated when out of engagement is used to switch off the speed limit mode, and to a value that allows the driver to engage the desired gear when vehicle speed exceeds the maximum allowed. The engine speed can be controlled by depressing the accelerator pedal so that the engine speed can be adjusted.

[0003] This uses the fact that there is no fixed relationship between vehicle speed and engine speed when the gearbox is neutral. It is irrelevant that the speed ratios (n / v) are different if they engage different gears.

If the engine speed is stable when the vehicle is traveling at a substantially constant speed by inertia, the engine speed / vehicle speed ratio (n / v) will be constant again. Immediately resuming (resetting) the speed control mode with the neutral gearbox will again prevent the driver from engaging the gears.

[0005]

[Problems to be solved by the invention]

 In view of the drawbacks of the conventional device, it is an object of the present invention to provide a device that can be improved to solve the problem and maintain comfortable driving characteristics.

[0006]

[Means for Solving the Problems]

 The problem is solved according to the present invention by a configuration in which a delay circuit is provided for delaying re-switching-on of the vehicle speed limiting device after an output signal no longer appears.

[0007] According to another advantageous embodiment, after a delay time when the vehicle is traveling downhill and during which the driver did not re-engage the gearbox, the speed limit mode is activated. Restarting (resetting) is prevented.

[0008]

[Embodiment of the invention]

The present invention is drawn to be suitable for vehicles with a diesel engine (not shown) (also not shown). The engine drives the wheels via a conventional clutch, transmission gearbox and transmission shaft. The fuel injector is provided with an electronic diesel control (EDC) including a main computer 10 which operates according to the principles described in DE-A-353198. For this purpose, various operating parameters are supplied to the main computer 10. They include the engine speed n, the vehicle speed v and the position FFG of the accelerator or drive pedal. The main computer 10 generates an output signal RWd indicative of the setting of the fuel injection pump to provide a desired amount of fuel injection determined by the pedal position FFG, the engine speed n and other parameters. In addition, the main computer 10 compares the vehicle speed v with the maximum allowable vehicle speed V _lim , ignores the pedal position signal FFG when V> V _lim and ignores the injected fuel amount RW d of the vehicle speed V A vehicle speed limiting device is provided to reduce the amount of idling to prevent further rise. If the car is traveling downhill, the vehicle speed may actually increase further.

When the vehicle is above the allowed maximum speed V _lim and the gearbox is neutral, the gearbox must be neutral in order for the driver to be able to control the engine speed n. It is necessary to be able to detect when the vehicle is in use and thereby remove the speed limit.

In a preferred embodiment of the present invention, the engine speed n and the vehicle speed V are provided to a division circuit 12 which calculates a ratio n / v. As long as a given gear is engaged, this ratio will be different for different gear ratios, and even when the vehicle is stationary, regardless of the actual engine speed and vehicle speed (acceleration, deceleration, stop). n / v is constant (within closed limits). When no gears are engaged, there is no fixed relationship between engine speed and vehicle speed, and the ratio n / v changes over time. Thus, this ratio n / v is supplied to a differentiating circuit 14, where the ratio is differentiated to produce Y = d / dt (nv) to Y = d (n / v) / dt, This value is zero as long as the gear is engaged, but will have some positive or negative value when the gearbox is neutral.

Since the sign of Y is not relevant, only its absolute value is relevant, the signal Y is applied through an absolute value generator 16 to an allowable threshold comparator 18 and the absolute value | Y | Is applied to the comparator 18 irrespective of its sign Y, and as soon as the absolute value | Y | is large enough to indicate that n and v are no longer correlated, ie as soon as the permissible threshold is exceeded. , The comparator 18 supplies a prohibition signal S to the main computer 10. This inhibit signal S switches off the vehicle speed limiting device so that the signal FFG is not ignored and allows the driver to control the engine speed n by means of the neutral gearbox.

If the driver does not engage the gearbox quickly, the engine speed n stabilizes with Y, and thus Y returns to zero, so that the signal S is removed. However, the main computer 10 incorporates a delay circuit 20, which prevents the vehicle speed limiting device from being switched on again after S = 0, for example, until a delay period of approximately 5 seconds has elapsed.

In the case of a vehicle traveling downhill with vehicle speed V> V _lim , the vehicle speed limiting device is prevented from being switched on again, even after this delay of about 5 seconds. Should. For this purpose, the engine speed n is compared in a comparator 22 with a speed n _max corresponding to the maximum permissible vehicle speed V _lim in the gearbox in which the top gear is engaged, and the output of the comparator 22 is determined by the computer. Supplied to 10 to prevent the vehicle speed limit mode from being switched on again when the engine is running at a constant speed, such as an idling speed, for more than a delay of about 5 seconds.

The vehicle speed signal V need not be a direct measurement of the speed of the vehicle. The appropriate signal can be obtained from the output of the clutch or from the transmission shaft.

[Brief description of the drawings]

FIG. 1 is a diagram showing an embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 10 main computer 16 absolute value generator 18 comparator 20 delay circuit

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Dayter Seer Germany D-7129 Ilsfeld Tour Burgoisichtulase 10

Claims (2)

[Utility model registration claims] An apparatus for detecting the presence or absence of a gear engagement state in a gear box of a mechanically propelled vehicle, for calculating a ratio between an engine rotation speed (n) and a vehicle speed (V). A further device (12) downstream of the device (12) for monitoring the ratio (n / V) to form an output signal indicating the occurrence of a change in the ratio (n / V). Equipment (14,16,1
8) and a vehicle speed limiting device (10) for a vehicle, for example, a vehicle equipped with a diesel engine, wherein the vehicle speed limiting device (10) has a vehicle speed limiting mode when no gear is engaged. A delay circuit (20) for delaying the re-switching-on of the vehicle speed limiting device after the output signal no longer appears, wherein An apparatus characterized in that: 2. The maximum allowable vehicle speed (V) when the actual engine speed (n) is engaged with the highest gear.
_{2. The} device according to claim 1, wherein the speed limiting device is switched off if the speed (n _max ) is lower than the speed (n _max ).