JPS6226125A - Constant speed traveling device for car - Google Patents

Abstract

PURPOSE:To automatically shift a transmission to a gear position at which fuel consumption is the lowest when carrying out constant speed traveling by providing a means of comparing fuel consumption at the present gear position with that when said gear position is varied. CONSTITUTION:A shifting actuator 20 and a selecting actuator 21, for selecting a gear position, are provided in a transmission 18. And, a car speed sensor 22 for detecting the number of revolutions on the output side of the transmission 18 and a gear position sensor 25 for detecting the position of a gear, are also provided and their outputs are inputted into a microcomputer 14. This computer 14 compares present fuel consumption with that when the gear is shifted down and, when the fuel consumption is judged to be lower if the gear is shifted down, it disconnects a clutch by means of an actuator 19, while shifting the transmission 18 to a one stage lower gear position by means of the actuators 20, 21.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a constant speed running device for an automobile, and in particular detects the vehicle speed, compares this vehicle speed with a set vehicle speed, and changes the amount of fuel supplied according to this comparison to perform constant speed running. This invention relates to a constant speed traveling device for automobiles. K Summary of the Invention The present invention provides a system for driving at a constant speed by comparing an actual vehicle speed with a set vehicle speed and changing the amount of fuel supplied according to the comparison. Detects the gear position, calculates the fuel consumption at the current gear position, calculates the fuel consumption when changing the gear position, compares the fuel consumption obtained by these calculations, and determines whether the fuel efficiency is better if the gear position is changed. By changing the gear position of the transmission when it is determined that the fuel consumption is decreasing, constant speed driving is always performed at the gear position that provides the lowest fuel consumption.

[Conventional technology]

When a car is driving on a highway, etc., it is not only difficult for the driver to adjust the amount of pressure on the accelerator pedal in order to maintain a constant vehicle speed, but it is also difficult for the driver to adjust the amount of pressure on the accelerator pedal while constantly detecting the vehicle speed using the speedometer. The operation becomes troublesome because the screw must be adjusted. Therefore, attempts have been made to equip vehicles with constant speed running devices. This constant speed traveling device is an application of a microcomputer, which detects the vehicle speed, compares this vehicle speed with a set vehicle speed by the microcomputer, and increases or decreases the amount of fuel supplied according to this comparison. Therefore, the actual vehicle speed is always controlled to be close to the set vehicle speed, and this enables automatic constant speed driving. Problem 1 that the invention aims to solve: However, in conventional constant-speed driving systems for automobiles, the engine is controlled by a microcomputer, so the gear position of the transmission remains fixed. Become. In other words, in the case of a passenger car, constant speed driving is performed with the transmission fixed at 4th or 5th speed. Therefore, it is not always possible to drive at a constant speed with optimal fuel efficiency, which leads to a deterioration in the fuel efficiency of the automobile. The present invention has been made in view of these problems, and reduces the fuel consumption of automobiles by always driving at a constant speed with the transmission switched to the gear position with the least fuel consumption. It is an object of the present invention to provide a constant speed traveling device for an automobile that is designed to achieve the following. Means for Solving Problem K] The present invention detects the vehicle speed, compares this vehicle speed with a set vehicle speed, and changes the amount of fuel supplied according to this comparison to perform constant speed driving. As shown in Fig. 1, this device has a means for detecting the gear position of the transmission, a means for calculating the fuel consumption at the current gear position, and a means for calculating the fuel consumption when the gear position is changed. and means for comparing the fuel efficiency at the current gear position with the fuel efficiency when changing the gear position, and when it is determined that changing the gear position will result in lower fuel consumption, the transmission gear position is changed. This is what I decided to change. [1] According to the present invention, the transmission is automatically switched to the gear position with the least fuel consumption when the vehicle is traveling at a constant speed, thereby minimizing the fuel consumption when driving at a constant speed. It becomes possible to limit K Embodiment The present invention will be described below with reference to an illustrated embodiment. FIG. 2 shows an engine for an automobile equipped with a constant speed traveling device according to an embodiment of the present invention, and this engine is composed of, for example, a diesel engine 10 for a truck. A fuel injection pump 11 is provided on the side of the engine 10, and is configured to sequentially inject and supply fuel to the cylinders of the engine 10. Further, this fuel injection pump 11 is driven by the engine 10 via a timer 12, and the timer 12
The injection timing is adjusted by The fuel injection pump 11 also includes an actuator 13,
This actuator 13 moves the control rack to control the amount of fuel supplied. And the actuator 13 is a microcomputer 14
It is now controlled by. Note that detection outputs from a rotation detection sensor 15 that detects the rotation of the engine 10 and a rack position sensor 16 that detects the rack position of the fuel injection pump 11 are input to the microcomputer 14, respectively. The flywheel housing 1 is located on the back side of the engine 10.
7 is provided, and a transmission 18 is disposed on the rear side of the housing 17. The clutch on the back side of the flywheel disposed inside the flywheel housing 17 is the clutch actuator 1.
9 controls its contact and separation. The transmission 18 also includes a shift actuator 20 and a select actuator 21 for selecting gear positions. The transmission 18 is also provided with a vehicle speed sensor 22 that detects the rotation speed on the output side of the transmission 18 and a gear position sensor 25 that detects the gear A7 position of the transmission 18. The output of .25 is input to the microcomputer 14. Furthermore, a constant speed running switch 24 is provided on the steering column 23, and this switch 24 is connected to the microcomputer 14. In the above configuration, when the vehicle equipped with this engine 10 is to travel at a constant speed, the constant speed travel switch 24 provided on the steering column 23 is turned on. Furthermore, the vehicle speed is set by a setting means not shown. Then, the microcomputer 14 compares the set vehicle speed with the actual vehicle speed obtained by the vehicle speed sensor 22, and controls the amount of fuel injected at one time by the fuel injection pump 11 according to this comparison. If the actual vehicle speed is lower than the set vehicle speed, the microcomputer 14 causes the actuator 13 to move the control rack in a direction that increases the amount of fuel. On the other hand, if the actual vehicle speed is higher than the set vehicle speed, the control rack is moved via the actuator 13 in a direction that reduces the fuel consumption. By such control of the fuel injection pump 11 by the microcomputer 14 and actuator 13, the vehicle equipped with this engine 10 runs at a substantially constant speed. Furthermore, during this constant speed driving, the transmission 18
is designed to automatically switch so that the gear position is always optimal. This operation is performed based on flowcharts 1 to 1 as shown in FIG. That is, the microcomputer 14 reads the rotational speed of the engine 10 using the rotation detection sensor 15, and also reads the gear position of the transmission 18 using the gear position sensor 25. Then, the current fuel consumption is calculated from the rotational speed of the engine 1O and the gear position of the transmission 18 while referring to the equal fuel consumption curve previously written in the ROM of the microcomputer 14. Furthermore, this microcomputer 14 sets the gear position of the transmission 18 to 1.
Similarly, the fuel consumption when downshifting is calculated with reference to the above-mentioned equal fuel consumption curve. Based on these calculation results, microcomputer 1
4 compares the current fuel consumption with the fuel consumption when downshifting, and if it is determined that shifting from 1 to down will result in lower fuel consumption, downshifting of transmission 18 is performed. done automatically. That is, the microcomputer 14 first disengages the clutch with the actuator 19, and then disengages the clutch with the shift actuator 20 and select actuator 21.
Transmission 1 in the downshifted gear position
Switch 8. According to the above judgment, if it is determined that downshifting will increase the fuel consumption, then conversely, the fuel consumption when shifting up by one gear is calculated. If it is determined that shifting up will reduce fuel consumption, one actuator disengages the clutch, and the shift actuator 20 and select actuator 2
1 to shift the transmission 18 up one step. Furthermore, if it is determined that shifting up will increase fuel consumption, the gear position of the 1-transmission 18 is not changed and the current state is maintained as it is. In general, conventional automatic transmission devices shift down only when the vehicle speed is still decreasing even under full load. On the other hand, in the vehicle according to this embodiment, the equal fuel consumption curve of the engine 10 is written in advance in the ROM of the microcomputer 14, and the microcomputer 14 detects the gear position with the gear position sensor 25, and also performs the gear shifting operation. After this has been carried out, the rotation speed of the engine 10 is detected by the rotation detection sensor 15, and the fuel efficiency when downshifting or upshifting is compared with the current fuel consumption, and it is determined that the fuel efficiency will be lower if downshifting or upshifting. In this case, the shift 1-down or shift-up operation is automatically performed as described above. Therefore, even if there is still room for the full load of the engine 10, downshifting will be performed if fuel efficiency is to be improved. Therefore, the constant speed traveling device according to this embodiment not only controls the amount of fuel supplied to drive the vehicle at a constant speed, but also automatically shifts the transmission 18 to the gear position that provides the lowest fuel consumption. It will be switched. Therefore, it is possible to significantly reduce fuel consumption, and since the gear position of the transmission 18 is automatically switched to the state with the lowest fuel consumption, the controllability of constant-speed driving is roughly improved. become. Effects of the Invention As described above, the present invention provides a means for detecting the gear position of a transmission, a means for calculating fuel consumption at the current gear position, and a means for calculating fuel consumption when changing the gear position. and a means for comparing the fuel efficiency at the current gear position with the fuel efficiency when changing the gear position, and when it is determined that changing the gear position will result in lower fuel consumption, the transmission gear position It was designed to change the . Therefore, according to the present invention, constant speed driving is performed while the transmission is always automatically switched to the lowest gear position, thereby making it possible to improve the fuel efficiency of the automobile.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the gist of the present invention, FIG. 2 is a side view of an engine equipped with a constant speed traveling device according to an embodiment of the present invention, and FIG. 5 is a flowchart showing an operation for changing the gear position of the gear. In the symbols used in the drawings, 10...Diesel engine 11...Fuel injection pump 13...Actuator 14...Microcomputer 18...One transmission...Clutch actuator 20... Shift actuator 21...Select actuator 22...Vehicle speed sensor 24...Constant speed running switch 25...Gear position sensor.

Claims (1)

[Claims] Means for detecting the gear position of a transmission in a device that detects vehicle speed, compares this vehicle speed with a set vehicle speed, and changes the amount of fuel supplied in accordance with this comparison to perform constant speed driving. a means for calculating fuel efficiency at the current gear position; a means for calculating fuel efficiency when changing the gear position; and a means for comparing the fuel efficiency at the current gear position and the fuel efficiency when changing the gear position. 1. A constant speed driving device for an automobile, characterized in that the gear position of the transmission is changed when it is determined that changing the gear position will reduce fuel consumption.