JPH04121433A - Device for preventing automatic transmission vehicle from backing on uphill road - Google Patents

Abstract

PURPOSE:To smoothly start a vehicle by sensing possibility of its backing in respect to a shift position at the time of starting, increasingly correcting a fuel jet amount, and thereby preventing the vehicle from backing at the time of starting on an uphill road. CONSTITUTION:In an electronic control device 50, a base fuel jet amount is calculated based on a signal from an intake air amount sensor 55, while the base fuel jet amount is corrected based on a signal from an engine condition detection sensor 56 to obtain a fuel jet amount. Whether a signal from a vehicle speed sensor is zero or not is judged, and when the answer is YES, whether a signal from a shift sensor 28 is set ON or not is judged. A vehicle inclination angle is calculated based on a signal from a vehicle inclination sensor 30, and a vehicle weight is calculated forma signal of a vehicle weight sensor 32. In case that the vehicle inclination angle is large, or the vehicle is heavy, the vehicle may be recede with a large gravity applied thereto. Thus, a correction coefficient is calculated based on the inclination angle and weight of the vehicle, thereby a fuel jet amount of a fuel jet device 12a is increasingly corrected.

Description

[Detailed Description of the Invention] [Summary] In order to prevent an automatic vehicle from moving backwards when starting on an uphill road, the vehicle is set to a shift position based on the outputs of a shift sensor, an inclination sensor, and a vehicle weight sensor. The system detects the possibility of moving backwards and corrects the fuel injection amount, or corrects the fuel injection amount when the vehicle moves in the opposite direction to the shift position based on the outputs of the shift sensor and forward/reverse movement sensor. I decided to do so.

[Industrial Field of Application] The present invention relates to an uphill road reverse prevention device for automatic vehicles.

[Conventional technology]

An automatic vehicle is equipped with a transmission consisting of a torque converter that transmits power using fluid, a gear unit, and a hydraulic control device. Automatic cars change gears automatically, so there is no engine stalling, and torque converters have a large torque ratio in the low speed ratio range, so there is no engine stalling even when starting. Therefore, an automatic car can start with ease just by releasing the brake pedal.

[Problems to be Solved by the Invention] In automatic vehicles, it is necessary to keep the brake pedal depressed when the vehicle is stopped. When the vehicle is stopped on a road, it is subject to a backward force due to gravity, and when the road is steep or the vehicle is heavily loaded, the force increases, and when the brake pedal is released to start, the vehicle moves backwards. Phenomena may exist. In such a case, if you felt the vehicle momentarily move backwards when starting up a hill, you would have had to press the accelerator before releasing the brake pedal.

However, for those who drive automatic cars, such busy continuous operation of the brake pedal and accelerator pedal is troublesome, and can be particularly difficult for beginners.

SUMMARY OF THE INVENTION An object of the present invention is to provide a device for preventing backward movement of an automatic vehicle on an uphill road, which prevents the vehicle from backing up when starting on an uphill road, and enables a smooth start.

[Means for Solving the Problems] A device for preventing backward movement on an uphill road for an automatic vehicle according to the first invention detects a shift position of a transmission in an automatic vehicle that controls the amount of fuel injection based on the engine operating state. A shift sensor, a tilt sensor that detects the vehicle's tilt state, a vehicle weight sensor that detects the vehicle weight, and based on the outputs of these sensors, it detects the possibility that the vehicle will move backwards from the shift position when starting. The present invention is characterized by comprising means for correcting the fuel injection amount.

A device for preventing backward movement on an uphill road for an automatic vehicle according to a second aspect of the present invention is an automatic vehicle that controls the amount of fuel injection based on the engine operating state, and includes a shift sensor that detects the shift position of the transmission, a shift sensor that detects the shift position of the transmission, and a forward direction and direction of the vehicle. The present invention is characterized by comprising forward and reverse movement sensors that detect movement in the backward direction, and means for correcting the fuel injection amount when the vehicle moves in the opposite direction to the shift position at the time of starting based on the outputs of these sensors. It is something to do.

[For production]

According to the first invention, the shift position of the transmission is detected, the possibility that the vehicle moves backward relative to the shift position at the time of starting is sensed, and the fuel injection amount determined according to the normal intake air amount etc. is corrected to increase. . The possibility that the vehicle will move backward is sensed based on the outputs of a tilt sensor that detects the tilt state of the vehicle and a vehicle weight sensor that detects the vehicle weight, that is, from the degree of tilt related to gravity and the vehicle weight. Ru.

According to the second invention, the shift position of the transmission is detected, and when the vehicle moves in the opposite direction to the shift position at the time of starting, the fuel injection amount determined according to the normal intake air amount etc. is increased. For this purpose, a forward/reverse movement sensor is provided that detects forward and reverse movement of the vehicle. For example, even if the transmission is in the D range (or R range), the vehicle is Detect when moving backward (or forward).

〔Example〕

FIG. 1 shows an automatic vehicle 10 according to a first embodiment of the present invention, which includes a vehicle body 10a, an engine 12, and a transmission 14. Engine 12 has a known electronically controlled fuel injection system. The transmission 14 includes a known torque converter 16, a gear unit, and a hydraulic control device, and a shift lever 18 is located at the driver's seat. The transmission 14 has a propeller shaft 20
It is connected to the rear axle shaft 22 via a differential and a differential, and drives the rear wheels 24. In the embodiment, the front wheel 26 is a free wheel.

In the embodiment shown in FIG.
A shift sensor 28 is provided to detect the No. 4 shift position. The shift sensor 28 may detect the position of the shift lever 18, or may receive a signal generated inside the transmission 14 depending on the position of the shift lever 18.

Furthermore, an inclination sensor 30 that detects the inclination state of the vehicle;
A vehicle weight sensor 32 for detecting vehicle weight is provided. An example of a tilt sensor 30 is shown in FIG. 2, and includes a magnetoresistive element 34 and a permanent magnet 36 arranged opposite each other. One of the magnetic resistance element 34 and the permanent magnet 36, for example, the permanent magnet 36, is fixed to the vehicle body 10a, and the magnetic resistance element 3
4 is attached to the vehicle body 10a so that it always remains vertical. Therefore, when the vehicle body 10a tilts, the relative positional relationship between the magnetoresistive element 34 and the permanent magnet 36 changes, and a changed electrical signal output is extracted from the magnetoresistive element 34. Further, an example of the vehicle weight sensor 32 is shown in FIG.
This consists of a displacement sensor 42 such as a piezoelectric element attached via a relatively strong spring 40 disposed between the suspension side member 38 and the vehicle body 10a.

FIG. 4 shows a fuel injection device 12a provided in the engine 12.
The configuration of an electronic control device 50 for controlling the electronic control device 50 is shown, and the electronic control device 50 is configured with a microcomputer,
Central processing unit (CPU) 51 with calculation and control functions
, to store programs or use one-domain memory (R
OM) 52 and a random access memory (RAM) 53 for storing data, etc., and these are interconnected by a bus 54. The electronic control device 50 includes a shift sensor 28, a tilt sensor 30, and a vehicle weight sensor 32.
In addition to inputting signals from the electronic control fuel injection device 12a, signals from various sensors basically used for the electronically controlled fuel injection device 12a are also inputted.

For example, in order to calculate the fuel injection amount, an intake air amount sensor 55, an engine state detection sensor 56 such as an engine cooling water sensor, an idle sensor, or a crank angle sensor, a vehicle speed sensor 57, etc. are used.

FIG. 6 is a flowchart showing a fuel injection amount calculation routine according to the first embodiment of the present invention. First, in step 60, the fuel injection amount is calculated. The fuel injection amount is normally obtained by determining the basic fuel injection amount based on the signal from the intake air amount sensor 55, and adding or multiplying the basic fuel injection amount by a correction amount based on the signal from the engine condition detection sensor 56. Next, in step 61, it is determined whether the vehicle speed is 0, and if YES, the process proceeds to step 62, where it is determined whether the signal from the shift sensor 28 is on. Here, shift-on means that the shift lever has shifted by 1 day, and 2. This includes forward positions such as L and reverse positions such as R, and excludes positions P and N.

If YES in step 62, the process proceeds to step 63 to determine whether the brake signal is on, and if NO in step 63, the process proceeds to step 64. Proceeding to step 64 through steps 61, 62, and 63 means that the automatic vehicle 10 is about to start from a stopped state.

In step 64, the vehicle inclination angle θ is calculated from the signal from the inclination sensor 30, and the process proceeds to step 65, where the vehicle weight G is calculated from the signal from the vehicle weight sensor 32.

If the vehicle inclination angle θ is large, or (including passengers)
When the vehicle weight G is heavy, there is a possibility that the vehicle will be subjected to large gravity and move backwards, and the present invention senses this possibility and increases the fuel injection amount determined according to the normal intake air amount, etc. .

Therefore, in step 66, a correction coefficient K is calculated from the vehicle inclination angle θ and the vehicle weight G. This correction factor has a fifth
As shown in the figure, it is predetermined and stored as a two-dimensional map of the vehicle inclination angle θ and the vehicle weight G. Therefore, the process proceeds to step 67, where the fuel injection amount determined in step 60 is further corrected by using this correction coefficient K. If the determinations at steps 61, 62, and 63 are opposite to those described above, the fuel injection amount determined at step 60 is used to perform fuel injection.

FIG. 7 shows a second embodiment of the invention, in which similar parts are given the same reference numerals as in the first embodiment.

In the second embodiment, a shift sensor 28 that detects the shift position of the transmission 14 is provided, and a forward/reverse movement sensor 7o that detects forward and backward movement of the vehicle is provided. In the embodiment, the forward/reverse movement sensor 70 is comprised of a forward/reverse vehicle speed sensor that reads a mark 72 provided on the rear axle shaft 22.

As shown in FIG. 8, the marks 72 are three rows of bar marks 72a, 72b, 72c provided at predetermined intervals.
Consisting of The forward/reverse movement sensor 70 includes a light emitting element 74 that illuminates the mark 72, a slit forming plate 76 that receives the light reflected by the mark 72, and light receiving elements 76a, 76b, and 76c that receive the light that has passed through the slit forming plate 76. The light receiving element 76a receives only the light reflected in the area of the bar mark 72a, the light receiving element 76b receives only the light reflected in the area of the bar mark 72b, and the light receiving element 76c receives only the light reflected in the area of the bar marks 72a, 72b, 72c. It is designed to receive only light. Therefore, it is possible to know in which direction the rear axle shaft 22 is rotating from the outputs of the light receiving elements 76a, 76b, and 76c, and it is also possible to know the rotational speed of the rear axle shaft 22, that is, the speed of the vehicle. Therefore, for example, the shift sensor 28 can detect the shift position D (R), and at the same time, the forward/reverse movement sensor 70 can detect the backward (forward) movement of the vehicle.

FIG. 9 shows the configuration of an electronic control device 50 for controlling the fuel injection device 12a, and the configuration is similar to that of FIG. 4 except that a forward/reverse movement sensor 70 is provided in place of the tilt sensor 30 and vehicle weight sensor 32. is almost the same.

FIG. 11 is a flowchart showing a fuel injection amount calculation routine according to a second embodiment of the present invention. first step 80
Intake air amount sensor 55 and engine condition detection sensor 5
The fuel injection amount is calculated based on the signal from 6. Next, in step 81, it is determined whether the signal from the shift sensor 28 is on. If YES in step 81, the process proceeds to step 82, where it is determined whether the signal from the forward/reverse movement sensor 70 indicates that the vehicle is moving backward (forward) with respect to the shift position fD (R) determined in step 81. If YES in step 82, it is determined that the vehicle is moving in the opposite direction to the shift position when starting, and step 8
Proceed to step 3 to calculate the correction coefficient K. This correction coefficient is predetermined and stored as a one-dimensional function with respect to the vehicle speed S, as shown in FIG. Therefore, step 8
The process proceeds to step 4, where the fuel injection amount determined in step 80 is further corrected to increase using this correction coefficient K. Step 81, 8
If the determination in step 2 is opposite to the above, step 8
Fuel injection is performed using the fuel injection amount determined in step 0.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to prevent the vehicle from moving backward when starting on an uphill road, and to perform an accelerator operation with sufficient margin.

[Brief explanation of the drawing]

1 is a diagram showing a first embodiment of the present invention, FIG. 2 is a diagram showing an inclination sensor, FIG. 3 is a diagram showing a vehicle weight sensor, and FIG. 4 is a diagram showing a vehicle weight sensor.
5 is a diagram showing the configuration of the fuel injection control device, FIG. 5 is a diagram showing a map of correction coefficients used in FIG. 6, FIG. 6 is a flowchart for calculating the fuel injection amount in the first embodiment, and FIG. 8 is a diagram showing a forward/reverse movement sensor, FIG. 9 is a diagram showing the configuration of a fuel injection control device of the second embodiment, and FIG. 10 is a diagram showing a second embodiment of the present invention. FIG. 11 is a flowchart for calculating the fuel injection amount in the second embodiment. 10a -- Vehicle body, 12 -- Engine, 14
... Transmission, 16... Torque converter, 18... Shift lever 28... Shift sensor, 30
... Tilt sensor, 32 ... Vehicle weight sensor, 7
0...Forward/reverse movement sensor.

Claims (2)

[Claims] 1. In an automatic vehicle that controls fuel injection amount based on engine operating conditions, there is a shift sensor that detects the shift position of the transmission, a tilt sensor that detects the tilting state of the vehicle, and a vehicle weight sensor that detects the vehicle weight. , and means for correcting the amount of fuel injection by detecting the possibility that the vehicle will move backward relative to the shift position when starting based on the outputs of these sensors. 2. In an automatic vehicle that controls fuel injection amount based on engine operating conditions, there are a shift sensor that detects the shift position of the transmission, a forward/reverse movement sensor that detects forward and reverse movement of the vehicle, and a shift sensor that detects the shift position of the transmission. A device for preventing backward movement on an uphill road for an automatic vehicle, comprising means for correcting a fuel injection amount when the vehicle moves in a direction opposite to a shift position at the time of starting based on the output of a sensor.