JPS6157214B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method and apparatus for controlling neutral travel, which saves fuel consumption by utilizing neutral travel during coasting, such as when an automobile is decelerating.

[Conventional technology]

Conventionally, when a car is driving and wants to stop temporarily at an intersection ahead, it first decelerates by releasing the accelerator pedal and applying engine braking, and then applies the brakes to accelerate the deceleration. Normally, the vehicle is brought to a temporary stop by depressing the pedal to apply braking force to the wheels.

[Problem that the invention seeks to solve]

However, when decelerating by engine braking by releasing the accelerator pedal, the engine operates at a slightly lower rotational speed than the rotational speed corresponding to the vehicle speed, so excess fuel is consumed until the vehicle speed becomes considerably low.

In recent years, more and more traffic lights have been installed, and as a result, the number of temporary stops has increased, so the above-mentioned extra fuel consumption also becomes a large proportion.

On the other hand, in order to save fuel consumption as mentioned above, some drivers may manually switch to neutral driving at their own discretion, but in that case, the driver must not accelerate until the vehicle comes to a stop or to accelerate again. Until the pedal is depressed, a simple operation is performed that leaves the vehicle in the neutral state, and fine-grained and appropriate timing is required to release the neutral except in the case of re-acceleration, or to switch back to the neutral after that. There is a problem that there is no neutral driving control.

The present invention has been developed in view of the above-mentioned problems, and it is possible to reliably issue a neutral command when the vehicle is decelerating by releasing the accelerator while the vehicle is running, or when coasting, such as when traveling gently downhill, and to issue the neutral command to be canceled in an appropriate manner. The purpose of this system is to easily realize fuel savings and ensure smooth and safe driving through neutral driving at the appropriate timing.

[Means for solving problems]

To this end, the first invention of the present application detects an accelerator operation while the vehicle is running and generates an operation signal, and also detects a neutral prohibition condition that makes the neutral state of the vehicle inappropriate and generates a prohibition signal. , automatically determining the release of the accelerator operation based on disappearance of the operation signal and issuing a command to transition to a neutral state, and upon receiving the prohibition signal, automatically issuing a command to cancel the neutral state;
A control method is constituted in which a transmission mechanism whose transmission position is switched and selected when the vehicle is running is switched to a neutral state by the transition command, and the neutral state of the transmission mechanism is canceled by the release command even when the accelerator operation is released. .

Further, the second invention of the present application configures a control device that automatically and appropriately implements the entire control method described above.

〔Example〕

An embodiment of the present invention shown in the drawings will be described below. Figure 1 shows the overall configuration of the system, which is applied to an automobile equipped with an automatic transmission control system. I am using it.

In FIG. 1, numeral 1 is a vehicle speed sensor that generates a vehicle speed signal corresponding to the traveling speed of the automobile. A throttle opening sensor 2 generates an opening signal corresponding to the opening of the throttle valve of the automobile engine. Reference numeral 3 denotes a shift control circuit which receives the vehicle speed signal and the throttle valve opening signal, determines a shift position according to the engine load, and generates a command signal therefor. Reference numeral 4 denotes a three-speed transmission mechanism, and when the first shift signal from the shift control circuit 3 is applied to the first switching valve 5, the hydraulic path is switched and the first gear shift position is established, which is suitable for starting the vehicle. In addition, the second shift signal is output from the shift control circuit 3.
When applied to the switching valve 6, the hydraulic path is switched and the 2nd gear shift position suitable for acceleration is established, and when the first and second shift signals are simultaneously applied to the first and second switching valves 5 and 6, the hydraulic path is changed. 3 suitable for switching and stable running
The gear position is set at the speed change position. 7 is a neutral N valve, which is provided at the starting point of the hydraulic path of the transmission mechanism 4; when a drive signal is applied, the hydraulic path is closed, the transmission mechanism 4 is forcibly switched to a neutral state, and the drive signal disappears. This opens the hydraulic path and returns to speed change control based on the operation of the first and second switching valves 5 and 6.

The automatic shift control system including the vehicle speed sensor 1, throttle opening sensor 2, shift control circuit 3, shift mechanism 4, first switching valve 5, and second switching valve 6 has the same configuration as the known system. , a detailed explanation thereof will be omitted.

8 is the accelerator pedal of an automobile, which is pressed by the driver to adjust the driving speed. Reference numeral 9 denotes an accelerator sensor, which is a switch that closes in conjunction with depression of the accelerator pedal and generates an operation signal. Reference numeral 10 denotes a neutral N prohibition condition sensor, which detects a driving condition that prohibits neutral driving, such as a steep downhill slope, and generates a prohibition signal. Reference numeral 11 denotes a neutral N switch, which is manually operated by the driver to issue a switch signal. Reference numeral 12 denotes a starting switch that is turned on when starting the automobile.When turned on, the engine is started, and when the switch is turned on, a starting signal is generated.

13 is a single-chip microcomputer that executes digital arithmetic processing according to a control program including a predetermined neutral control program, and a crystal oscillator 14 of several megahertz (MHz).
A stabilizing power supply circuit (not shown) that starts operating when the engine key switch is connected and the engine key switch is turned on.
It enters the operating state by receiving a stabilized voltage of 5V from For driving control, an operation signal from the accelerator sensor 9, a prohibition signal from the N prohibition condition sensor 10, a switch signal from the N switch 11, and a start signal from the start switch 12 are received, and both the operation signal and the prohibition signal disappear. It generates a neutral N command signal when any signal is generated, generates an N reset signal when any of the signals is generated, and generates a similar signal depending on the presence or absence of a start signal or switch signal. This microcomputer 1
3 is a read-only memory (ROM) that stores various control programs including a neutral control program that defines calculation procedures for neutral travel control, and a read-only memory (ROM) that sequentially reads out the control programs in this ROM and executes the procedures. The central processing unit (Central processing unit) executes the corresponding arithmetic processing.
Processing Unit (CPU)) and memory (Random Access Memory (RAM)) that temporarily stores various data related to the arithmetic processing of this CPU and allows the CPU to read the data when necessary.
The main components include a clock generator that uses a crystal oscillator 14 to generate reference clock pulses for the various calculations described above, and an input/output (I/O) circuit that adjusts the input and output of various signals to and from the outside. of semiconductors
It is made of LSI (Large Scale Integration) circuit. Reference numeral 15 denotes a drive circuit that latches the N command signal from the microcomputer 13 to operate the N valve 7. The latch signal is reset by the N reset signal from the microcomputer 13, and the operation is performed by latching the N command signal. When the N-valve 7 is activated, the transmission mechanism 4 is controlled to a neutral state, and upon reset, the N-valve 7 is turned off to release the neutral state and return to the shift position under automatic shift control.

The microcomputer 13 constitutes an arithmetic processing means, and the drive circuit 15 and the N valve 7 constitute a drive means.

Next, the operation of the above configuration will be explained with reference to the calculation flowcharts of FIGS. 2 and 3.

2 is a calculation flowchart showing the overall calculation processing of the microcomputer 13 according to the control program, and FIG. 3 is a calculation flowchart showing the detailed calculation processing of the neutral control routine forming the neutral control program in FIG.

First, the arithmetic processing of this microcomputer 13 will be explained. Now, in an automobile equipped with this device, when the vehicle starts operating, the microcomputer 13 receives a stabilized voltage from the stabilized power supply circuit and starts operating. As a result, the calculation process starts from the start step 100 in FIG.
Proceeding to the initial setting routine 200, the registers, counters, latches, etc. in the microcomputer 13 are set to the initial state necessary for starting arithmetic processing.
Proceed to neutral control routine 300.

In this neutral control routine 300, calculations are performed to control the on/off operation of the N valve 7 based on signals from the accelerator sensor 9, the N prohibition condition sensor 10, the N switch 11, and the start switch 12, and to set and reset the neutral state. The process is executed and the process proceeds to the next various system control routines 400.

This various system control routine 400 executes arithmetic processing for controlling various in-vehicle systems, and then returns to the neutral control routine 300.
Descriptions of the various sensors and their respective drive units related to the arithmetic processing of the various system control routines 400 will be omitted.

Then, the arithmetic processing from the neutral control routine 300 to the various system control routines 400 is repeated to control neutral driving.

The detailed arithmetic processing of this neutral control routine 300 is shown in FIG. That is, by arriving at this neutral control routine 300, the start determination step 30 in FIG.
1, whether or not it is time to start the engine is determined based on the presence or absence of a starting signal from the start switch 12, and the determination is YES at startup, but the determination is NO at times other than startup. Then, the process proceeds to the next N switch determination step 302. In this N switch determination step 302, the presence or absence of a switch signal due to manual operation of the N switch 11 is determined.
When the switch signal is generated, the determination becomes YES, but when the switch signal disappears, the determination becomes N, and the process proceeds to the next accelerator operation determination step 303. In this accelerator operation determination step 303, whether or not the accelerator pedal 8 is depressed is determined based on the presence or absence of an operation signal from the accelerator sensor 9. When the accelerator pedal 8 is released, the operation signal from the accelerator sensor 9 disappears, so this determination is made. becomes NO, but since an operation signal is generated from the accelerator sensor 9 when the accelerator pedal 8 is depressed, the determination is not possible.
When the result is YES, the program proceeds to the next N reset step 304, where an N reset signal for resetting the neutral state is applied to the drive circuit 15, and one operation of the neutral control routine 300 is completed.

On the other hand, when the judgment in the accelerator operation judgment step 303 is NO, the process proceeds to the N prohibition condition judgment step 305. In this judgment step 305, it is determined whether or not a neutral prohibition condition has occurred based on the presence or absence of a prohibition signal from the N prohibition condition sensor 10, and when a prohibition signal is generated, the determination is YES.
The process proceeds to N reset step 304, but if no prohibition signal is generated, the determination is NO.
Then, the process advances to N command step 306. In this N command step 306, an N command signal is applied to the drive circuit 15 in order to control switching to a neutral state.
One operation of the neutral control routine is completed.

Also, if either one of the start-up determination step 301 and the N switch determination step 302 is determined,
When the result is YES, the N command step 306 is reached, and the control is switched to the neutral state, and one calculation of the neutral control routine 300 is completed.

Next, the overall operation of the neutral control in various states will be sequentially explained.

First, when the key switch is turned on to start driving this automobile, the microcomputer 13 is activated by supplying a stabilized voltage from the stabilized power supply circuit, and the process proceeds from the start step 100 in FIG. 2 to the initial setting routine 200. After the initial settings are made, the calculations of the neutral control routine 300 and various system control routines 400 are repeated. At this time,
In the neutral control routine 300, steps 301 to 301 for determining the start time, step 302 for determining the N switch, step 303 for determining the accelerator operation,
The N command step 306 is reached through the N prohibition condition determination step 305, and the N command signal is sent to the drive circuit 1.
Add to the S terminal of 5. Therefore, this drive circuit 15
latches the signal, closes the N valve 7, and forcibly controls the transmission mechanism 4 to a neutral state. Then, the arithmetic processing through each of the above steps 301, 302, 303, 305, and 306 is repeated until the various detection states change.

Next, press start switch 1 to start the engine.
2, the starter rotates and a starting signal is applied to the microcomputer 13. Therefore, when the start time determination step 301 in FIG. In addition to the circuit 15, the N valve 7 is kept closed to maintain the transmission mechanism 4 in a neutral state to ensure safe engine starting. Then, when the start is completed, the start signal from the start switch 12 disappears, so the calculation of the neutral control routine 300 is based on the determination at the start time determination step 301 in FIG.
Reversed from YES to NO, N switch determination step 302, accelerator operation determination step 303, N prohibition condition determination step 305, N command step 30
Pass through 6. Return to arithmetic processing and maintain neutral state.

Next, when the accelerator pedal 8 is depressed to start the vehicle, an operation signal is generated from the accelerator sensor 9, so that the accelerator operation determination step 3 in FIG. 3 is performed.
03, the determination is reversed from NO to YES, and the process does not proceed to N prohibition condition determination step 305.
Proceeding to reset step 304, the N reset signal is applied to the R terminal of the drive circuit 15. Therefore, this drive circuit 15 is reset to open the hydraulic path of the transmission mechanism 4 to turn off the N valve 7, and the automatic transmission control device controls the transmission position. As a result, when starting, the first switching valve 5 operates and the transmission mechanism 4
is controlled to the 1st gear position to perform an appropriate start. Thereafter, as the traveling speed increases, the vehicle switches from the second gear position to the third gear position, and shifts to stable running.

At this time, the accelerator pedal 8 is being depressed and the accelerator sensor 9 continues to generate operation signals, so the microcomputer 13 executes the starting judgment step 301, the N switch judgment step 302, and the accelerator operation judgment step in the neutral control routine 300. 303, performs arithmetic processing through N reset step 304, and resets the drive circuit 1.
5 is applied with an N reset signal to maintain the N valve 7 in the OFF state.

Next, when the accelerator pedal 8 is released during deceleration, if the N prohibition condition has not occurred, the operation signal from the accelerator sensor 9 disappears, and the prohibition signal from the N prohibition condition sensor 10 is generated. The neutral control routine 300
At this time, the judgment at the accelerator operation judgment step 303 is reversed from YES to NO, and the process proceeds to the N prohibition condition judgment step 305, where the judgment becomes NO, and the process proceeds to the N command step 306. 15, the N valve 7 is operated to forcibly switch the transmission mechanism 4 to a neutral state. Thereafter, while the accelerator is released, the same calculation process is used to maintain the neutral state, and the engine rotation is maintained at a low speed regardless of the traveling speed at that time, thereby saving fuel consumption. Therefore, when the vehicle temporarily stops at an intersection or the like, it is possible to save fuel consumption from the start of deceleration until the vehicle stops, and the more frequently the vehicle stops, the greater the saving effect becomes.

Furthermore, even when the accelerator pedal 8 is released on a gentle downhill slope, it is possible to control the vehicle to a neutral state in the same way as described above, thereby saving fuel consumption.

On the other hand, under conditions where it is dangerous to switch to neutral, such as a steep downhill slope, the N prohibition condition sensor 10 generates a prohibition signal, so when the accelerator is released, the neutral control routine 300 reaches the N prohibition condition determination step 305. When this happens, the judgment becomes YES and the N command step 3
Instead of proceeding to step 06, the program proceeds to N reset step 304 to apply the N reset signal to the drive circuit 15. Therefore, the N valve 7 is turned off and the vehicle does not enter the neutral state, maintaining the shift position under automatic shift control, so that safe downhill travel can be achieved by applying appropriate engine braking.

On the other hand, if a re-acceleration operation is performed after a temporary deceleration while the N prohibition condition is not occurring, the operation signal from the accelerator sensor 9 disappears when the accelerator pedal 8 is released at the start of deceleration, and the N prohibition sensor Since the prohibition signal from 10 is not generated, the neutral control routine 300 performs arithmetic processing through the start determination step 301, the N switch determination step 302, the accelerator operation determination step 303, the N prohibition condition determination step 305, and the N command step 306. , an N command signal is applied to the drive circuit 15, the N valve 7 is operated, and the transmission mechanism 4 is forcibly switched to the neutral state. Therefore, the vehicle gradually decelerates due to coasting. To accelerate again from this decelerated driving state, the accelerator pedal 8
When the accelerator sensor 9 is depressed, an operation signal is generated from the accelerator sensor 9. As a result, in the neutral control routine 300 of the microcomputer 13, the determination in the accelerator operation determination step 303 is performed.
Reverse from NO to YES, N reset step 30
Proceeding to step 4, the N reset signal is applied to the drive circuit 15, the N valve 7 is turned off to release the neutral state, and the hydraulic path is opened to supply hydraulic pressure to the first and second switching valves 5 and 6. Therefore, the transmission control circuit 3, which receives signals from the vehicle speed sensor 1 and the throttle opening sensor 2, controls the operation of the first and second switching valves 5 and 6 to switch the transmission mechanism 4 to an appropriate transmission position. , it is possible to shift to appropriate acceleration driving.

In addition, in order for the driver to forcefully switch to the neutral state by manual operation, the N switch 11 is activated.
When the N switch 11 is turned on, a switch signal is applied to the microcomputer 13. Therefore, when the N switch determination step 302 is reached from the startup determination step 301 in the neutral control routine 300 of the microcomputer 13, the determination is reversed from NO to YES.
The process does not proceed to the accelerator operation determination step 303, but proceeds to the N command step 306, where the N command signal is applied to the drive circuit 15, the N valve 7 is operated, and the hydraulic path to the first and second switching valves 5 and 6 is closed. The transmission mechanism 4 is forcibly switched to a neutral state.

Furthermore, since the switch signal disappears when the N switch 11 is released, the N switch determination step 30 is performed.
2, the determination is reversed from YES to NO, and the process returns to normal arithmetic processing, which proceeds to accelerator operation determination step 303.

In the above-described embodiment, the automatic shift control is performed by the shift control circuit 3, but the automatic shift control may also be centrally controlled by the microcomputer 13.

Further, although the example shown is applicable to an automobile equipped with an automatic transmission control device, it may also be applied to a manual transmission type automobile. It may also be of a semi-automatic type, which includes a display that indicates the switch to the neutral state and allows the driver to manually switch to the neutral state based on the display.

Furthermore, although the neutral running control is performed by digital calculation processing of software by the microcomputer 13, similar control may be performed by a digital electronic circuit, an analog electronic circuit, etc. of ordinary hard logic.

〔Effect of the invention〕

As described above, in the first invention of the present application, when the vehicle is decelerating by releasing the accelerator while the vehicle is running, or when coasting such as when traveling on a gentle downhill slope, a neutral shift command is appropriately and reliably issued to promptly It will now be possible to switch to neutral driving, and even after switching to neutral driving, automatic detection of neutral prohibition conditions will enable prompt release commands to be issued to precisely control neutral driving. It has excellent effects. Therefore, there is an excellent effect that it is possible to easily achieve fuel savings through neutral running and ensure smooth running that follows changes in conditions at an appropriate timing.

Furthermore, in the second invention of the present application, in addition to the above-mentioned effects, it is possible to provide a device that appropriately and automatically controls transition to and cancellation of neutral driving in response to various condition changes. This has an excellent effect.

[Brief explanation of the drawing]

FIG. 1 is an overall configuration diagram showing an embodiment of the present invention;
FIG. 2 is a calculation flowchart showing the calculation processing of the control program of the microcomputer shown in FIG. 1, and FIG. 3 is a calculation flowchart showing the detailed calculation processing of the neutral control routine shown in FIG. 4... Speed change mechanism, 7, 15... N valve and drive circuit forming drive means, 9... Accelerator sensor, 10... N prohibition condition sensor, 13... Microcomputer forming calculation processing means.

Claims (1)

[Scope of Claims] 1. Detecting accelerator operation while the vehicle is running and generating an operation signal, detecting a neutral prohibition condition that makes the neutral state of the vehicle inappropriate and generating a prohibition signal, and detecting the accelerator operation. automatically determines the release of the operation signal based on disappearance of the operation signal and issues a command to shift to a neutral state, switches a transmission mechanism whose shift position is selected while the vehicle is running to a neutral state by the shift command, and prohibits the above-mentioned prohibition. A method for controlling neutral running, comprising: automatically issuing a command to release the neutral state upon receiving a signal; and using the release command, the neutral state of the transmission mechanism is released even when the accelerator operation is released. 2. An accelerator sensor that emits an operation signal when an accelerator operation is detected while the vehicle is running; a determination means that determines the presence or absence of an operation signal from this accelerator sensor and generates a neutral command signal when the operation signal disappears; and a neutral control signal by this determination means. A drive means that receives a command signal and controls a transmission mechanism, whose transmission position is switched and selected when the vehicle is running, to a neutral state, and a prohibition device that generates a prohibition signal when detecting a neutral prohibition condition that makes the neutral state of this vehicle inappropriate. A condition sensor, and a prohibition determining means for reversing the driving means and releasing the neutral state of the transmission mechanism upon receiving a prohibition signal from the prohibition condition sensor, with priority over a neutral command signal from the determination means. Neutral travel control device.