JP4141302B2 - Vehicle speed limiter - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a speed limiting device for an automatic transmission vehicle.
[0002]
[Prior art]
The speed limiter controls the engine speed so that the vehicle speed does not exceed the limit value. In order to match the engine rotation to the gear rotation at the time of shift down, the clutch may be disengaged and the accelerator may be depressed during shift down, and even if this operation is performed while the vehicle speed is limited, the maximum engine rotation will be low. Because it can be suppressed, there is a possibility that the rotation of the engine does not match well.
[0003]
In the conventional example, there is a switch that is turned on when the clutch pedal is depressed, and a means for temporarily releasing the vehicle speed limit while the switch is turned on. Since it is set to turn on when it is depressed to the extent that it becomes a half-clutch, the vehicle speed restriction can be intentionally released not by adjusting the engine speed during downshifting but by pedal operation. For this reason, a switch that detects the neutral of the shift lever is provided to allow the release of the vehicle speed limit only during a shift (Patent Document 1).
[0004]
In order to realize both fuel consumption and easy drive, there is an electronically controlled mechanical type as one of automatic transmissions mainly for large vehicles (Patent Document 2). This system performs an engine control unit that controls engine rotation / engine torque according to the accelerator opening or engine rotation / engine torque according to the control command for automatic shift, and automatic shift to the target stage according to the operating state. A transmission control unit for controlling the engagement / disengagement of the clutch (mechanical friction clutch) and the gear shift of the transmission (gear-type transmission), a communication means for exchanging control commands between them, the engagement / disengagement of the clutch, and the transmission And a means for manually controlling the accelerator opening of the engine manually.
[0005]
[Patent Document 1]
JP-A-11-351000 [Patent Document 2]
JP 2001-227630 A
[Problems to be solved by the invention]
Even in such an automatic transmission, it is conceivable to add a speed limiting function (including a function of temporarily canceling the vehicle speed limitation during shifting). In that case, the speed limit function is set in the engine control unit, but when the engine control unit receives a control command from the transmission control unit, it performs control to match the engine rotational speed to the request, Since the clutch is not engaged and the shift position of the transmission is not ascertained, if the vehicle is manually controlled manually (during manual shifting by the driver), the engine is There is a possibility that rotation alignment cannot be performed. At least at the time of shifting by the driver's manual operation, the engine speed cannot be increased beyond the maximum speed limit of the vehicle speed limit.
[0007]
An object of this invention is to provide an effective means for solving such a problem.
[0008]
[Means for Solving the Problems]
According to a first aspect of the present invention, there is provided an engine control means for controlling engine rotation / engine torque according to an accelerator opening degree during non-shifting, and engine rotation / engine torque according to a control command for automatic shifting during shifting, Transmission control means for controlling the clutch engagement and transmission gear shift to perform automatic shift to the target stage according to the state, communication means for exchanging control commands between them, clutch engagement and transmission Means for controlling the engine speed so that the vehicle speed does not exceed the limit value, and a control command from the transmission control means in an automatic transmission vehicle having a gear shift and means for manually controlling the accelerator opening of the engine and means for performing control command from transmission control means during shifting undergoing is in preference to the vehicle speed limit, Trang During shifting not receiving a control command from the transmission control means is characterized in that setting means for canceling the vehicle speed limiting, to the engine control unit.
[0009]
According to a second aspect of the present invention, in the vehicle speed limiting device according to the first aspect of the invention, no control command is received from the transmission control means, and the control command of the communication means does not exist or is invalid .
[0010]
According to a third aspect of the present invention, in the vehicle speed limiting device according to the first aspect of the invention, there is provided means for determining whether or not communication between the engine control means and the transmission control means is normal, and receives a control command from the transmission control means. The communication means is not normal .
[0011]
According to a fourth aspect of the present invention, in the vehicle speed limiting device according to the third aspect of the present invention, there is provided clutch pedal detecting means for detecting that the clutch pedal is not depressed, and the result of detection by the clutch pedal detecting means is not accepted during the shift. Suppose that there is .
[0013]
【The invention's effect】
In the first aspect of the invention, during the shift receiving the control command (engine control command necessary for automatic shift) from the transmission control means, the engine control necessary for the shift is executed in the engine control means in preference to the vehicle speed limit. Therefore, it is possible to increase the engine rotation at the time of downshifting to a value higher than the maximum rotation speed limit.
[0014]
Further , during the shift without receiving a control command from the transmission control means, the vehicle speed limit is released, so that the engine speed can be increased to the maximum speed or higher of the vehicle speed limit by the driver's accelerator operation.
[0015]
In the second aspect of the invention , the vehicle speed limit is canceled during a shift in which a control command from the transmission control means does not exist or is invalid, so that the engine speed is increased to a value higher than the maximum speed limit by the driver's accelerator operation. It becomes possible to make it.
[0016]
In the third aspect of the invention , the vehicle speed limit is released during a shift where the communication with the transmission control means is not normal, so that the engine speed can be increased to the maximum speed limit or higher by the driver's accelerator operation. It becomes.
[0017]
In the fourth invention , when the communication with the transmission control means is not normal, the detection result of the clutch pedal detection means becomes “No” (the clutch pedal is depressed), and during that period, the vehicle speed restriction is released. The engine speed can be increased beyond the maximum speed of the vehicle speed limit by the driver's speed change operation.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
In FIG. 1, 1 is a diesel engine, 2 is a friction clutch, 3 is a synchronous mesh transmission (transmission), and the output shaft of the transmission 3 is connected to a rear axle via a propeller shaft (not shown). An electronic governor device 1A for controlling the fuel injection amount in the engine fuel injection pump, a clutch booster 2A for driving the clutch 2 to connect / disconnect (an automatic control system and a manual control system are provided in the circuit configuration), and a gear shift for driving the gear shift to the transmission 23 A unit 3A is provided. Reference numeral 27 denotes a supply / exhaust valve of the clutch booster 2.
[0019]
As detection means necessary for vehicle shift control, an engine rotation sensor 29 that detects the engine speed, an accelerator opening sensor 28 that detects the amount of depression of the accelerator pedal 7 (the required amount of accelerator opening), and the stroke position of the clutch 2 A clutch stroke sensor 22 that detects the shift position, a shift position sensor that detects the shift position of the transmission 3 (built in the gear shift unit 3A), a vehicle speed sensor 21 that detects the rotational speed from the output shaft of the transmission 3, and a main shaft of the transmission 3 Is provided with a gear rotation sensor 23 for detecting the rotation speed of the main gear that idles.
[0020]
In order to switch between manual control and automatic control of the clutch 2, a clutch engagement switch 24 that detects an initial position of the clutch pedal (clutch 2 engagement state) and a clutch disconnection switch 25 that also detects a depression position (disengagement state of the clutch 2). And are provided. A shift lever unit 4 is provided in the cab as a shift instruction means of the transmission 3 and outputs a shift position signal (shift instruction signal) of the shift lever 4A. In addition, a display unit 13 that displays the shift position of the transmission 3 in the driver's cab, a manual shift mode in which the vehicle shift is performed in accordance with the shift operation of the driver, and an automatic shift mode in which the shift is automatically performed according to the driving state A switch 31 (automatic shift switch) for selection and a foot brake switch 26 for detecting depression of a brake pedal (not shown) are provided. 13A is an alarm buzzer.
[0021]
The transmission control unit 11 and the engine control unit 12 are responsible for transmission control, and are connected by serial communication so that transmission information and control commands (control commands) can be exchanged. The engine control unit 12 normally controls the electronic governor device 1A so that the fuel injection pump supplies the fuel injection amount corresponding to the detection signal of the accelerator opening sensor 28 and the detection signal of the engine rotation sensor 29, while the transmission When a control command (control command) is received from the control unit 11 , the electronic governor device 1A is controlled so that an engine speed corresponding to the command is obtained.
[0022]
When the automatic shift switch 31 is ON, the transmission control unit 11 obtains the target stage from the shift map (preliminarily set in the memory) based on the detection signal of the vehicle speed sensor 21 and the detection signal of the accelerator opening sensor 28, and shifts. When the detection signal (current stage) of the position sensor does not coincide with the target stage, it is determined that a shift to the target stage is necessary, and the detection signal of the clutch stroke sensor 29 and the shift position are set so as to smoothly perform the shift to the target stage. Based on the detection signal of the sensor, the detection signal of the gear rotation sensor 23, and the detection signal of the vehicle speed sensor 21, the clutch booster 1A and the gear shift unit 3A are controlled. Communicate to. When the automatic shift switch 31 is OFF, the gear shift unit 3A is controlled based on the shift instruction signal of the shift lever unit 4 and the detection signal of the shift position sensor in order to perform a gear shift according to the shift lever operation of the shift lever unit 4. . The clutch booster 2A is switched to manual control when the clutch pedal is depressed, and can be operated with a stroke corresponding to the amount of depression. This operation is communicated from the transmission control unit 11 to the engine control unit 12 as shift information.
[0023]
A vehicle speed limiting function is added to the engine control unit 12. The vehicle speed limiting function controls the electronic governor device 1A based on the detection signal of the vehicle speed sensor 21 so that the vehicle speed does not exceed the limit value (the fuel injection is reduced), so that the rotation can be adjusted during shifting. The vehicle speed limit release condition is set. FIG. 2 is a flowchart for explaining the vehicle speed limiting function. In S1, the detection value of the vehicle speed is compared with the limited vehicle speed, and it is determined whether or not the vehicle speed> the limited vehicle speed. If the determination of S1 is yes, the process proceeds to S2, while if the determination of S1 is no, there is no need to limit the vehicle speed, the process jumps to S8 and normal control of the electronic governor device 1A (according to the engine speed and accelerator opening) Control for supplying the fuel injection amount).
[0024]
In S2, it is determined whether the serial communication connecting the transmission control unit 11 and the engine control unit 12 is normal. If the determination of S2 is yes, the process proceeds to S3. If the determination of S2 is no, the process jumps to S7. In S7, it is determined whether the clutch engagement switch is OFF (whether the clutch pedal is depressed). When the determination in S7 is yes, it is determined that the manual shift operation by the driver is started, so the process proceeds to S8, while when the determination in S7 is no, the process proceeds to S6.
[0025]
In S3, it is determined whether or not shifting is in progress (whether or not transmission information is communicated). When the determination of S3 is yes, the process proceeds to S4, while when the determination of S3 is no, the process jumps to S6 and executes vehicle speed restriction based on the determination of S1. In S4, it is determined whether or not the engine control command is absent (or invalid). If the determination in S4 is yes, it is determined in S5 that the shifting in S3 is due to manual control, so the vehicle speed restriction is canceled (fuel injection amount reduction control is temporarily canceled). On the other hand, when the determination of S4 is no, it is determined that the shift in S3 is due to automatic control. Therefore, in S6, the engine control according to the control command from the transmission control unit 11 is given priority over the control of the vehicle speed limit. And execute.
[0026]
With such a configuration, during normal times, the fuel injection amount corresponding to the accelerator opening and the engine speed is supplied within the vehicle speed limit range, and when the vehicle speed limit is exceeded, the fuel injection is reduced, and the engine speed is limited to the vehicle speed. It can be suppressed below the maximum rotation. When the automatic shift is started during traveling, the engine speed, the engagement / disengagement of the clutch 2, the gear disengagement and the gear engagement of the transmission 3 are controlled in accordance with a predetermined processing sequence. Since the engine control according to the control command from the unit 11 is executed with priority over the vehicle speed limit control, the shift operation to the target stage is also smoothly performed.
[0027]
When a manual shift is performed, the engine control unit 12 determines that a shift without a control command is in progress, and if the vehicle speed is being limited, the limitation is canceled. Therefore, the engine rotation can be increased beyond the maximum rotation speed limit by the driver's accelerator operation.
[0028]
If communication between the transmission control unit 11 and the engine control unit 12 is impaired, it is not determined whether or not the gear is being shifted, but the vehicle speed limit is released by the depression of the clutch pedal by the driver. The rotation of the engine can be matched with the shift, and the vehicle can continue running without any problem.
[0029]
In FIG. 2, the process from S1 to S5 is a means for canceling the vehicle speed limit during a shift where the control command is not received (or invalid) from the transmission control unit 11, and the process from S1 to S4 to S6 is the transmission control unit. 11 is a means for executing a control command in preference to vehicle speed limitation during a speed change in which a control command is received. Processing from S1, S2, S7 to S8 is not normal, and if the clutch pedal is depressed, the vehicle speed is Means for releasing the restriction.
[0030]
With such control settings, the vehicle speed limit function (including the function to temporarily cancel the vehicle speed limit during shifting) of an automatic transmission vehicle is inexpensive, without newly increasing the number of detection means using existing detection means. Can be realized.
[Brief description of the drawings]
FIG. 1 is a schematic diagram of a system representing an embodiment of the present invention.
FIG. 2 is a flowchart for explaining the control content of the engine control unit.
[Explanation of symbols]
1A Electronic governor device 2A Clutch booster 3A Gear shift unit 4 Shift lever unit 11 Transmission control unit 12 Engine control unit 21 Vehicle speed sensor 22 Clutch stroke sensor 23 Gear rotation sensor 24 Clutch contact switch 28 Acceleration opening sensor 29 Engine rotation sensor 31 Automatic transmission switch

Claims (4)

Engine control means for controlling engine rotation / engine torque according to accelerator opening during non-shifting, and engine rotation / engine torque according to control command for automatic shifting during shifting,
Transmission control means for controlling the engagement and disengagement of the clutch and the gear shift of the transmission to perform automatic gear shifting to the target stage according to the driving state;
A communication means for exchanging control commands between them,
Means for artificially manually controlling clutch engagement / disengagement, gear shifting of the transmission, and accelerator opening of the engine;
In an automatic transmission vehicle comprising:
Means for controlling the engine speed so that the vehicle speed does not exceed the limit value;
Means for executing the control command from the transmission control means in preference to the vehicle speed limit during the shift receiving the control command from the transmission control means;
Means for releasing the vehicle speed limit during a shift that does not receive a control command from the transmission control means;
A speed limiting device for an automatic transmission vehicle, characterized in that is set as an engine control means. 2. The vehicle speed limiting device according to claim 1, wherein not receiving a control command from the transmission control means means that the control command of the communication means does not exist or is invalid . The means for determining whether or not the communication between the engine control means and the transmission control means is normal and not receiving a control command from the transmission control means means that the communication means is not normal. The speed limiter described . 4. The speed limiting device according to claim 3, wherein clutch pedal detecting means for detecting that the clutch pedal is not depressed is provided, and the result of detection by the clutch pedal detecting means is negative during the shift .

Images