JP2512971B2 - Traction control device - Google Patents

Description

The present invention relates to a traction control device, and more particularly, to a traction control device in a vehicle equipped with a torque converter.

[Prior Art] When a vehicle accelerates on a road surface having a low coefficient of friction, such as a snowy road or a gravel road, a so-called acceleration slip phenomenon in which drive wheels spin idle is likely to occur. Conventionally, various traction control devices have been proposed in order to prevent the acceleration slip phenomenon. Among these, for example, when the slip ratio between the road surface and the drive wheels exceeds a predetermined value, a sub-throttle provided in the intake pipe in addition to the main throttle is closed to suppress the intake air amount and reduce the engine output. Things are known. Also, instead of closing the sub-throttle, the number of cylinders for combustion is reduced (described in JP-A-58-8436),
Alternatively, one that cuts fuel injection and one that adjusts the ignition advance angle are also known.

[Problems to be Solved by the Invention] However, further improvement has been demanded for the following points. Since these traction control devices control the torque generated by the engine, in a vehicle in which a torque converter and a transmission gear are provided between the crankshaft of the engine and the drive shaft of the drive wheels, the characteristics of the torque converter Was not sufficiently controlled. Therefore, for example, sufficient control is not performed even when the torque ratio of the torque converter is greatly different between the case of accelerating from a stop time and the case of accelerating from a running time, and traction control is performed depending on the torque ratio of the torque converter. There was a problem that was too effective or insufficient.

An object of the traction control device of the present invention is to solve the above problems and to accurately perform traction control of a vehicle equipped with a torque converter.

Configuration of the Invention The configuration of the present invention that achieves the above object will be described below.

[Means for Solving Problems] The traction control device of the present invention is mounted on a vehicle in which the output of the engine M1 is transmitted to the drive wheels M3 via a torque converter M2, as illustrated in FIG. A traction control device for suppressing the drive torque of the drive wheel M3 during traction control, wherein a speed ratio between the rotation speed of the engine M1 and the output rotation speed of the torque converter M2 is obtained, and the torque converter M2 is calculated from the speed ratio. Drive torque detection means M4 for detecting the drive torque of the drive wheel M3 based on the characteristics of the, and predict the engine generated torque that can be generated when the full accelerator in the current operating state, based on the predicted value A required torque determining means M7 for determining a required torque for traction control, and whether or not the detected driving torque exceeds the determined required torque. And a drive torque suppressing means M6 that suppresses the drive torque when it is determined that the drive torque exceeds the drive torque.

The required torque may be a value that the driver can arbitrarily set according to the frictional state between the drive wheel M3 and the road surface, or a value obtained by detecting the friction coefficient of the road surface and using this friction coefficient may be used. Further, the maximum drive torque at the time of full accelerator operation may be predicted from the current engine speed Ne and turbine speed Nt, and the required torque may be an appropriate ratio to the predicted maximum drive torque.

The driving torque suppressing means M6 can be realized by reducing the number of combustion cylinders, reducing the opening of the sub-throttle, cutting fuel, adjusting ignition timing, and the like.

[Operation] The traction control device of the present invention having the above configuration,
When the determining means M5 determines that the drive torque of the drive wheel M3 detected by the drive torque detecting means M4 exceeds the required torque, the drive torque suppressing means M6 suppresses the drive torque. In this way, since the drive torque is obtained and controlled in consideration of the characteristics of the torque converter M2, the traction control accuracy is improved.

[Embodiment] In order to further clarify the configuration and operation of the present invention described above, a preferred embodiment of the traction control device of the present invention will be described below.

As shown, the engine 1 is controlled by an engine controller (hereinafter also referred to as ECU) 3. Engine 1
The output shaft (crank shaft) 4 of the engine is the input shaft of the torque converter 5, and the power of the engine 1 is the torque converter.
5, transmitted to the drive wheels 9, 10 via the transmission gear 7.

The intake pipe 11 of the engine 1 is provided with an air flow meter 12, a sub throttle 13, a main throttle 15, a surge tank 18 and an injection valve 20 from the upstream side. The opening of the sub throttle 13 is adjusted during the torque down control, and the opening of the main throttle 15 is adjusted according to the depression amount of the accelerator pedal 23. Sub throttle 13
The main throttle 15 and the main throttle 15 are driven by DC motors 26 and 28, respectively, and the DC motors 26 and 28 are connected to the ECU 3.
The injection valve 20 is a well-known electromagnetic type, and is opened by a drive signal from the ECU 3 to inject fuel toward the intake port 31.

Further, the crankshaft 4 of the engine 1 is provided with a distributor 39 that distributes and applies the high voltage generated by the igniter 34 to the ignition plug 37 of each cylinder according to the crank angle. Cylinder discrimination sensor in distributor 39
43 and the crank angle sensor 45 are connected to the ECU 3. In addition to the above, the ECU 3 further includes an accelerator opening sensor 49 for detecting the depression amount of the accelerator pedal 23, a traction control dial 51 including a volume operated by a driver, and left and right drive wheels.
Turbine for detecting the rotational speed (turbine rotational speed) Nt of the drive wheel speed sensor 52 provided in the transmission gear 7 for detecting the average rotational speed of 9, 10 and the output shaft provided for the output shaft of the torque converter 5. The rotation speed sensor 55 and the like are connected.

The ECU 3 is configured as an arithmetic and logic operation circuit centering on the well-known CPU 62, ROM 64, RAM 65, input / output (I / O) port 67 and analog-digital converter (ADC) 68. ROM6
A traction control routine program, which will be described later, and various characteristic data are stored in advance in 4.

The operation of the traction control device thus configured will be described. FIG. 3 shows a flowchart of the traction control routine. After starting, the ECU 3 executes this control routine at appropriate times. First, the engine speed Ne and the turbine speed Nt, which are obtained in advance based on the signals from the crank angle sensor 45 and the turbine speed sensor 55, are read, and the respective values are assigned to the variables x and y assigned to the RAM 65.
Store in (step 110, 120).

Engine speed for the read turbine speed Nt
The speed ratio e of Ne is calculated (step 130), and the process proceeds to the process of obtaining the current engine generated torque Te from the value of the speed ratio e.
The value of the capacity coefficient C with respect to the speed ratio e is obtained using the capacity coefficient characteristic curve f1 (e) shown in FIG. 4 which is stored in the ROM 64 in advance (step 140), and the capacity coefficient C is obtained by squaring the engine speed Ne. The engine generated torque Te is calculated (step 150).

Further, using the engine performance curve f2 (Ne) shown in FIG. 5, the maximum engine generated torque Temax (point B in the figure) at the current engine speed Ne (see point A in the figure) is determined (step 160). When the current engine generated torque Te (point A in the figure) is smaller than the maximum engine generated torque Temax (point B in the figure), 10 is added to the variable x and step 13 is performed again.
The process from 0 to step 160 is repeated to obtain the calculated engine generated torque Te and the maximum engine generated torque Temax (A1 and B1 points in the figure) (steps 170 and 180). The calculated engine torque Te is the maximum engine torque Te
The maximum engine-generated torque Temax (point C in the figure) when it reaches max is the predicted value of the engine-generated torque that can be generated when the full accelerator is maintained in the current operating state. That is, the predicted value of the maximum engine-generated torque Temax is obtained along the one-dot chain line arrow shown in FIG.

Furthermore, the torque converter performance curve f3 in FIG.
The torque ratio t is obtained from the speed ratio e using (e) (step 190), and the maximum generated torque Temax previously obtained for the torque ratio t is obtained.
Is calculated to obtain the predicted value of the maximum drive torque Ttm that can be generated on the turbine shaft of the torque converter 5 (the maximum drive torque of the turbine shaft that can be generated when the full accelerator is set in the current operating state) (step 200).

Next, read the engine speed Ne again (step
210), the current drive torque Tt of the torque converter 5 is calculated in the same procedure (steps 220, 230, 240, 250). Also, the value A of the traction control dial 51 is read and RAM6
Store in variable a of 5 (step 260). The driver's required torque a · Ttm is calculated by multiplying the variable a by the maximum driving torque Ttm obtained previously. The driver sets the traction control dial 51 to the value A in advance in consideration of the condition of the road surface. That is, the drive wheels 9, 9
When it is judged that the coefficient of friction with 10 is low, set the value A to 10-30
Set it as low as about [%] and 70 when the road surface is dry.
Set it to a high value of about 90%.

Subsequently, it is compared whether or not the current drive torque Tt of the turbine shaft exceeds the required torque a · Ttm (step 270). When it does not exceed the value, the value of the variable x is increased by 10, the processes of steps 220 to 270 are executed again, and the calculated drive torque Tt of the turbine shaft is obtained. The value of the variable x when the calculated driving torque Tt exceeds the required torque a · Ttm is set as the fuel cut speed Nefc of the engine 1 (step 280). This fuel cut speed Nefc
When the engine speed Ne exceeds, the flag XEFC is set to the value 1, fuel injection is stopped, and the fuel cut speed
When Nefc is not reached, flag XEFC remains reset and fuel injection continues (steps 290, 300, 31).
0). Therefore, when the fuel cut speed Nefc is exceeded, even if the driver attempts to accelerate by depressing the accelerator pedal 23, fuel injection is stopped and the drive torque Tt of the turbine shaft is suppressed.

As described above, the traction control device of the present embodiment has the maximum driving torque Tt of the turbine shaft from the current operating state.
Predicting m, multiplying the predicted maximum driving torque Ttm by the value A set by the driver to obtain the required torque a · Ttm, and driving the turbine shaft obtained from the engine speed Ne and turbine speed Nt. The engine speed when the torque Tt exceeds the required torque a · Ttm is set as the fuel cut speed Nefc. Therefore, when the engine speed Ne exceeds the fuel cut speed Nefc, the traction control is necessary and the drive torque is suppressed.

Therefore, according to the traction control device of the present embodiment, the traction control is performed with due consideration of the characteristics of the torque converter, and the control accuracy can be improved. The fact that the traction control is too effective or insufficient depending on the magnitude of the torque ratio of the torque converter is eliminated. Although the turbine rotation speed Nt is obtained from the turbine rotation speed sensor 55 in this embodiment, it may be calculated from the drive wheel speed sensor 52 and the gear ratio of the transmission gear 7 instead.

Next, a modified example of the traction control device of the above embodiment will be described. All other configurations are the same except that steps 270 to 310 are replaced with steps 350 to 370 of the traction control routine. In the traction control device of this embodiment, the driving torque Tt is the required torque a.
・ If it exceeds Ttm, set flag XEFC, and if not, keep reset (steps 350, 360,
370) only. Therefore, when the flag XEFC is set to the value 1 without paying attention to the engine speed Ne, the sub-throttle 13 is fully closed or the ignition timing of the ignition plug 37 is adjusted and driven by another control routine. Torque can be suppressed.

Effects of the Invention As described in detail above, according to the traction control device of the present invention, the traction control is performed with due consideration of the characteristics of the torque converter, and the control accuracy can be improved. Moreover, the required torque, which is the determination condition, predicts the engine-generated torque that can be generated when the full accelerator is applied in the current operating state, and is determined based on the predicted value. Even if the torque ratio of the torque converter greatly differs from the acceleration from the time, the traction control can be preferably maintained.

[Brief description of drawings]

FIG. 1 is a block diagram illustrating the configuration of a traction control device of the present invention, FIG. 2 is a configuration diagram schematically showing the configuration of an engine and its peripheral devices of an embodiment, and FIG. 3 is a flowchart showing a traction control routine. FIG. 4 is a characteristic diagram showing a performance curve of the torque converter, FIG. 5 is a characteristic diagram showing a performance curve of the engine, and FIG. 6 is a flowchart showing a traction control routine of another embodiment. M1 ...... engine M2 ...... torque converter M3 ...... drive wheel M4 ...... drive torque detection means M5 ...... determination means M6 ...... drive torque suppression means M7 ...... required torque determination means 1 ...... engine 3 ...... engine controller ( ECU) 5 …… Torque converter 7 …… Transmission gear 9,10 …… Drive wheel 45 …… Crank angle sensor 51 …… Traction control dial 55 …… Turbine speed sensor

Claims (1)

(57) [Claims] 1. A traction control device mounted on a vehicle in which an output of an engine is transmitted to a drive wheel through a torque converter, and suppressing a drive torque of the drive wheel during traction control, wherein: A drive torque detecting means for obtaining a speed ratio with respect to the output speed of the torque converter and detecting the drive torque of the drive wheels based on the characteristics of the torque converter from the speed ratio, and a full accelerator in the current operating state. And a demanded torque determining means for determining a demanded torque for traction control based on the estimated value, and a demanded torque for which the detected drive torque is determined. Determination means for determining whether or not the drive torque exceeds the drive torque, and drive torque suppression for suppressing the drive torque when determined to exceed the drive torque And a traction control device comprising: