JPH06270721A - Synthetic control device of power train - Google Patents

Abstract

PURPOSE:To avoid sudden variation of engine output and advance the practi cable switchover time of a variable valve system to a high speed operation mode when the oil temperature is equal to or less than a specified temperature by fixing the cam of an output characteristic variable engine to a certain cam and equipping a control means for accomplishing change control of an automatic transmission speed change characteristic. CONSTITUTION:The oil temperature of an oil pressure type variable valve system is detected by an oil temperature detecting means 103. When the detected result is equal to or lower than the specified temperature, a control means 104 judges that it is the low temperature time with high driving oil viscosity and fixes the can of an output characteristic variable engine 101 to a certain cam. When the oil temperature detection signal of an oil sensor 211 indicates a temperature lower than the specified temperature, a controller 213 fixes the cam to a fuel consumption cam by means of a cam switchover control. Power train control is accomplished by switching the speed change characteristic of an automatic transmission 202 over to a two-dimensional speed change characteristic, by means of speed change control, corresponding to a vehicle speed for low oil temperature time and the engine throttle opening.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a comprehensive control system for a power train which controls a driving force of a power train which is a tandem combination of an engine with variable output characteristics and an automatic transmission.

[0002]

2. Description of the Related Art As a conventional variable output characteristic engine, for example, as disclosed in Japanese Unexamined Patent Publication No. 3-111610, it is not necessary to use only one type of cam for opening and closing an engine intake / exhaust valve. 2. Description of the Related Art There is known a variable valve operating engine capable of switching output characteristics with respect to throttle opening.

As shown by the valve lift amount characteristic of FIG. 6, this engine has a fuel economy cam (hereinafter referred to as P-cam) that emphasizes fuel economy for engine partial load, and a low speed cam useful at low revolution ( Hereinafter, three types of intake / exhaust valve cams including an L-cam) and a high-speed cam useful for high rotation (hereinafter referred to as H-cam) are provided, and these cams are used for engine drive load and engine rotation. It is used properly from the number to match the current driving.

By properly using this, as shown in the output torque characteristic diagram when the throttle is fully opened in FIG.
The output characteristics can be switched between when the cam is used, when the L cam is used, and when the H cam is used.

However, in such a variable valve type engine, although the drive of the variable valve is controlled by controlling the hydraulic pressure of the hydraulic variable valve according to the engine speed, the drive at low temperature is performed. When the viscosity of the oil is high, the intake valve or the exhaust valve should be switched from the low-speed operation mode to the high-speed operation mode as the engine speed increases.
Even if the hydraulic pressure of the variable valve mechanism is switched, the variable valve mechanism does not operate immediately because the viscosity of the drive oil is high. Therefore, even though the engine is in the high-speed operation mode, the intake / exhaust valve remains in the low-speed operation mode, which causes a sudden variable movement when the oil temperature rises and the viscosity decreases. There is the inconvenience that the valve switches to a high-speed operating mode, causing a sudden change in engine output.

For this reason, as a device for avoiding a sudden change in engine output, there is, for example, the device disclosed in Japanese Patent Laid-Open No. 64-19131. According to this device, the variable drive type oil temperature is measured, and when it is lower than a predetermined temperature, it is fixed to the low speed cam so that the variable valve suddenly switches from the low speed operation mode to the high speed operation mode. By avoiding this, and further, by stopping the fuel supply at an engine speed lower than the fuel supply speed of the engine in the operation mode for high speed, excessive high engine speed is avoided.

[0007]

However, according to the above-mentioned prior art, when the temperature is lower than a predetermined temperature, the low-speed cam is fixed, and when the engine speed is higher than a predetermined value,
Although it is possible to avoid a sudden change in engine output by stopping the supply of fuel, there is a problem that emission of fuel (exhaust gas components) deteriorates due to fuel cut.

[0008] Further, in traveling with a low accelerator opening, there is also a problem that the temperature of the drive oil rises slowly, so that the variable valve is slow to reach the high-speed operation mode.

The present invention has been made in view of the above, and it is possible to avoid a sudden change in engine output without deteriorating the emission, and to switch the variable valve to a high-speed operation mode. The purpose is to expedite possible times.

[0010]

In order to achieve the above object, the present invention, as shown in the claim correspondence diagram of FIG. 1, switches a plurality of cams for opening and closing an engine intake / exhaust valve to output power with respect to a throttle opening. An oil for detecting the oil temperature of a hydraulic variable valve waiting for the output characteristic variable engine 101 in a power train including a tandem connection of an output characteristic variable engine 101 for changing the characteristic and an automatic transmission 102 for switching a plurality of shift stages. When the oil temperature detected by the temperature detecting means 103 and the oil temperature detecting means 103 is equal to or lower than a predetermined temperature, the cam of the output characteristic variable engine 101 is fixed to a specific cam, and the shift characteristic of the automatic transmission 102 is changed. And a control means 104 for performing the above.

It should be noted that the above-mentioned control means 104 controls the transmission characteristic of the changed automatic transmission 102 and the automatic transmission 1 before the change.
When compared with the gear shift characteristic of 02, the gear shift characteristic is changed so that the gear shift up is performed at a lower vehicle speed side than the normal time in the region where the throttle opening is large, and in the region where the throttle opening is small, the gear shift is smaller than that at the normal time. It is desirable to change the gear shifting characteristics so that the gear shift up is performed at the higher vehicle speed side.

[0012]

The oil temperature detecting means 103 detects the oil temperature of the hydraulic variable valve. When the detection result is equal to or lower than the predetermined temperature, the control means 104 determines that the driving oil has a high viscosity and is at a low temperature, fixes the cam of the variable output characteristic engine 101 to a specific cam, and automatically shifts the automatic transmission 102. In the above control, the driving force is controlled by switching to the two-dimensional gear shift characteristic corresponding to the vehicle speed for low oil temperature and the engine throttle opening.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings.

FIG. 2 shows a configuration diagram of a power train to which the present invention is applied. In the figure, 201 denotes an output characteristic variable engine that switches a plurality of cams that open and close an engine intake / exhaust valve to change the output characteristic with respect to a throttle opening, and 202 denotes an automatic transmission that switches a plurality of gear stages.

The variable output characteristic engine 201 burns the injected fuel by the intake air sucked from the air cleaner 203 through the throttle valve 204, transmits the output thus obtained to the automatic transmission 202, and exhausts the fuel exhaust gas to the exhaust pipe 205. To release through. The accelerator pedal 206 is mechanically connected to the throttle valve 204. Further, in the cam switching mechanism 207, the cam switching is performed by the cam switching control valve 208.

The automatic transmission 202 shifts the rotational power from the variable output characteristic engine 201 at a gear ratio according to the selected gear and transmits it to the output shaft 209. In addition, the automatic transmission 20
2 is electronically shift-controlled via the control valve 210.

Reference numeral 211 denotes an output characteristic variable engine 2
01 is an oil temperature sensor as an oil temperature detecting means for detecting the oil temperature of the hydraulic variable valve waiting, 01 is a throttle valve 2
A throttle opening sensor for detecting the throttle opening 04, 213 indicates a controller as a control means for controlling the entire power train configured by using a macro processor.

Here, the controller 213 includes an oil temperature detection signal from the oil temperature sensor 211, an engine status signal such as engine speed (Ne), a transmission status signal such as vehicle speed (V), and a throttle opening sensor. 212 throttle opening (T
VO) is input to execute cam switching control (control command CAM) and shift control (control command S).

The operation of the above configuration will be described. When the oil temperature detection signal of the oil temperature sensor 211 indicates a temperature lower than a predetermined temperature, the controller 213 fixes the cam to the fuel consumption cam by the cam switching control, and changes the shift characteristic of the automatic transmission 202 to the low oil temperature by the shift control. The power train is controlled by switching to a two-dimensional gear shift characteristic corresponding to the vehicle speed and engine throttle opening for time.

FIG. 3 shows a two-dimensional gear shift characteristic with respect to the vehicle speed and the engine throttle opening in the low gear shift range in the gear shift control of the automatic transmission 202.
Dimensional shift characteristics, the broken line shows the two-dimensional shift characteristics when the oil temperature is low. Also, → in the figure indicates shift up,
When the two-dimensional gear shift characteristic at low oil temperature and the two-dimensional gear shift characteristic at normal oil temperature are compared, when the oil temperature is low, the shift shift is made at a lower vehicle speed side than in the normal state in a region where the throttle opening is large. In the region where the throttle opening is small, the gear shift up is performed at a higher vehicle speed side than in normal times.

FIG. 4 shows a cam map for normal temperature (that is, a cam map other than when the temperature is low).
Reference numeral 13 determines the next cam shift speed from the normal temperature cam map based on the engine speed and the throttle opening.

FIG. 5 shows that the controller 213
9 shows a flowchart of cam switching control / shift control processing executed every msec. The controller 213 first inputs the detection signal (here, an analog signal) of the oil temperature sensor 211, performs A / D conversion to measure and calculate the oil temperature T _oil (S501), and a pulse signal synchronized with the rotation of the engine. The output value of each crank sensor (not shown) that generates
The engine speed Ne is measured and calculated by measuring the frequency or the period (S502).

Subsequently, an analog signal corresponding to the throttle opening output from the throttle opening sensor 212 is
/ D conversion to measure and calculate throttle opening TVO (S5
03), the vehicle speed V is measured and calculated by measuring the frequency or the cycle of the output value of a vehicle speed sensor (not shown) that generates a pulse signal synchronized with the rotation of the wheels (S504).

Next, the oil temperature T _oil is compared with a predetermined oil temperature T _cold at which normal cam switching drive cannot be performed (S
505), if T _oil ≤T _cold , the fuel economy cam (P cam) is selected as the next cam CM _next (S506), and the vehicle speed V and the throttle opening are calculated using the low temperature shift map shown by the broken line in FIG. Next gear G _next is selected from TVO (S507).

On the other hand, if T _oil ≤T _cold is not satisfied, the condition shown in FIG.
Using the cam map for normal temperature shown in, the engine speed N
Next cam C based on e and throttle opening TVO
M _next is selected (S508), and the vehicle speed V and the throttle opening T are calculated using the normal speed shift map shown by the solid line in FIG.
The next gear G _next is selected from VO (S509). Next, in the selected cam output in step S510, the control command CAM is output to the cam switching control valve 208 based on the selected next cam CM _next to perform the cam switching control (S51).
0), similarly, with the selected gear output in step S510,
Based on the selected next gear G _next , a control command S is output to the control valve 210 to perform gear shift control (S
511).

As described above, in the present embodiment, when the oil temperature is low, the gear shift characteristic used for gear shift control of the automatic transmission 202 is changed to a gear shift up at a vehicle speed lower than usual in a region where the throttle opening is large. By changing to the gear shift characteristics that enable, it is possible to avoid excessive high engine speed even when the fuel consumption cam is fixed.

When the oil temperature is low, the automatic transmission 20
By changing the shift characteristics used for shift control 2 to shift characteristics that shift up at higher vehicle speeds than normal in the region where the throttle opening is small, the oil temperature rise is promoted and switching to a high-speed cam is performed. It is possible to accelerate the possible time.

Further, since the above control is carried out without stopping the fuel supply, it is possible to avoid a rapid change in the engine output without deteriorating the emission, and to operate the variable valve at a high speed. It is possible to speed up the time when it can be switched to.

[0029]

As described above, according to the present invention,
The oil temperature of the hydraulic variable valve is detected by the oil temperature detecting means, and when the detection result is lower than a predetermined temperature, it is determined that the viscosity of the driving oil is high, and the output characteristic variable engine cam is set to a specific cam. In addition, in the control of the automatic transmission, the control of the driving force is executed by switching to the two-dimensional gear shift characteristic corresponding to the vehicle speed for low oil temperature and the engine throttle opening, which causes deterioration of emission. It is possible to avoid a sudden change in the engine output without having to do so, and it is possible to accelerate the time when the variable valve can be switched to the high-speed operation mode.

[Brief description of drawings]

FIG. 1 is a diagram corresponding to a claim of the present invention.

FIG. 2 is a configuration diagram of an integrated control device for a power train according to the present embodiment.

FIG. 3 is an explanatory diagram showing a two-dimensional gear shift characteristic with respect to a vehicle speed and an engine throttle opening in a low gear range of the automatic transmission.

FIG. 4 is an explanatory diagram showing a cam map for normal temperature.

FIG. 5 is a flowchart of a cam switching control / shift control process of the present embodiment.

FIG. 6 is an explanatory diagram showing valve lift amount characteristics of three conventional types of intake and exhaust valve cams.

FIG. 7 is a conventional output torque characteristic diagram when the throttle is fully opened.

[Explanation of symbols]

 101 Variable Output Characteristic Engine 102 Automatic Transmission 103 Oil Temperature Detection Means 104 Control Means

Claims (2)

[Claims] 1. A power train comprising a tandem combination of an output characteristic variable engine for switching a plurality of cams for opening and closing an engine intake / exhaust valve to change an output characteristic with respect to a throttle opening, and an automatic transmission for switching a plurality of shift stages. In the output characteristic variable engine, the oil temperature detecting means for detecting the oil temperature of the hydraulic variable valve waiting for the output characteristic variable engine; and if the oil temperature detected by the oil temperature detecting means is below a predetermined temperature, the cam of the output characteristic variable engine Is fixed to a specific cam and is provided with control means for changing the shift characteristic of the automatic transmission. 2. The control means, when comparing the shift characteristic of the changed automatic transmission with the shift characteristic of the changed automatic transmission before the change, in a region where the throttle opening is large, the vehicle speed side is lower than the normal speed. 2. The shift characteristic is changed so as to shift up in the shift mode, and the shift characteristic is changed so as to shift up in a higher vehicle speed side than a normal time in a region where the throttle opening is small. Integrated control system for power train.