JPH08278212A - Detector of engine torque and line pressure controller of automatic transmission - Google Patents

Abstract

PURPOSE: To make possible matching in small number of manhours by detecting an intake charge state of an engine and making a constant of an engine torque expression variable on the basis of the intake charge state. CONSTITUTION: An air intake flow detection means detects an air intake flow Q of an engine, and an engine speed detection means finds out an engine speed N. An engine torque calculation means calculates engine torque TQ in accordance with an expression TQ=K.Q/N (K: constant) from an air intake flow Q and an engine speed N. An intake charge state detection means detects an intake charge state of the engine, and a constant variation means make the constant K of the engine torque calculation expression variable on the basis of the detected intake charge state. A line pressure setting means sets line pressure on the basis of the engine torque calculated by the engine torque calculation means. The line pressure means drives a line pressure actuator on the basis of the set line pressure and controls the line pressure of an automatic transmission.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine torque detecting device and a line pressure control device for controlling the line pressure of an automatic transmission (automatic transmission) for a vehicle using the same.

[0002]

2. Description of the Related Art In an automatic transmission for automobiles, the discharge pressure of an oil pump is regulated to obtain a line pressure, which is supplied to a hydraulic circuit to operate hydraulic pressure of a torque converter and various transmission elements in a gear type transmission. However, the line pressure is controlled to an appropriate hydraulic pressure according to the engine output (torque).

That is, in an automatic transmission, the line pressure, which is the source of operating oil pressure for the torque converter and various speed change elements, must be adjusted to an appropriate oil pressure according to the torque generated by the engine. The gear shift is fast, but the torque transmission efficiency is high, and engine vibration and gear shift shock are transmitted to the output shaft, resulting in increased noise and vibration. If the hydraulic pressure is lower than the proper value during the shift, the shift shock is small, but slippage occurs and the transmission efficiency is reduced, which causes a feeling of extension during the shift, and also deteriorates the durability of the automatic transmission and further reduces fuel consumption. Becomes worse.

Therefore, conventionally, the intake air per unit rotation is calculated from the intake air flow rate Q detected based on the signal from the air flow meter and the engine speed N calculated based on the signal from the crank angle sensor. The engine torque TQ = K · Q / N (K is a constant) is calculated as the one corresponding to the amount, and the line pressure is set by referring to the map in which the optimum line pressure is determined in advance, Based on this, the line pressure actuator is driven to control the line pressure (see Japanese Patent Laid-Open No. 3-249466).

[0005]

However, in the engine torque detecting device in such a conventional automatic transmission line pressure control device, engine torque TQ = intake air amount per unit rotation (Q / N) × constant K. However, when K is a constant in the entire engine operating region, this engine torque calculation formula does not hold. This is because the intake charge efficiency of the engine changes depending on the engine speed and the like.

Further, Japanese Utility Model Application Laid-Open No. 1-69946 describes that a line pressure is referred to from a map based on an intake air amount Q / N per unit rotation and an engine speed N. According to this, since the line pressure is referred in consideration of the engine speed N as well, it is considered that the deterioration of the estimation accuracy of the engine torque due to the change of the intake charging efficiency of the engine does not pose a problem.

However, in order to match "relationship between Q / N and torque" and "relationship between torque and line pressure" in one map, a large number of man-hours are required for matching. Further, Japanese Patent Laid-Open No. 63-266258 discloses that the engine torque is calculated from the rotational speeds of the input shaft and the output shaft of the power transmission device (TOKUKU converter) to set the line pressure.

However, this system has a drawback that the engine torque cannot be calculated when the torque converter is locked up, and a sensor for detecting the rotational speed of the output shaft of the torque converter is required, which is expensive. In view of such conventional problems, an object of the present invention is to provide an accurate engine torque detection device that does not require an expensive device and can perform matching with a small number of steps.

Another object of the present invention is to provide an automatic transmission line pressure control device using such an engine torque detecting device.

[0010]

Therefore, in the invention according to claim 1, as shown in FIG. 1 (in the dotted frame), an intake air flow rate detecting means for detecting an intake air flow rate Q of the engine, and an engine From the engine speed detecting means for detecting the speed N and the intake air flow rate Q and the engine speed N, TQ
= K · Q / N (K is a constant), an engine torque calculating device including an engine torque calculating unit for calculating the engine torque TQ, and an intake filling state detecting unit for detecting an intake filling state of the engine; A constant varying means for varying the constant K in the engine torque calculation formula on the basis of the intake air charging state is provided.

In the invention according to claim 3, as shown in FIG. 1, line pressure setting means for setting the line pressure based on the engine torque calculated by the engine torque calculating means, and based on the set line pressure And a line pressure control means for controlling the line pressure of the automatic transmission by driving the line pressure actuator.

According to the second and fourth aspects of the present invention, the intake charge state detection means detects the engine speed as the intake charge state of the engine.

[0013]

According to the first aspect of the present invention, the intake air flow rate Q and the engine speed N are detected to obtain the intake air amount (Q / N) per unit rotation, while the intake charge state of the engine is detected. The constant K in the engine torque calculation formula is variably set based on the detected intake charge state. And
The engine torque is calculated as TQ = K · Q / N.

Therefore, the engine torque can be accurately estimated even if the intake charge state of the engine changes. According to the third aspect of the present invention, the line pressure control becomes more appropriate by controlling the line pressure based on the engine torque accurately estimated as described above.

In the inventions according to claims 2 and 4, by detecting the engine speed as the intake charge state of the engine,
It does not require a special sensor and can be implemented at low cost.

[0016]

EXAMPLE An example of the present invention will be described below. Referring to FIG. 2, an automatic transmission 2 is provided on the output side of engine 1. The automatic transmission 2 includes a torque converter 3 interposed on the output side of the engine 1, a gear type transmission 4 connected via the torque converter 3, and a gear type transmission 4
And a hydraulic actuator 5 for performing connection / disconnection operations of various transmission elements therein. The operating oil pressure for the hydraulic actuator 5 is ON / OFF controlled via various electromagnetic valves, but only the electromagnetic solenoid valves 6A and 6B for shifting for automatic shifting are shown here. Reference numeral 7 is an output shaft of the automatic transmission 2.

Here, in order to obtain the line pressure which is the operating oil pressure for the torque converter 3 and the hydraulic actuator 5, the oil pump 8 driven by the input shaft of the gear type transmission is used, and the orifice 9 and the electromagnetic valve are used.
A pressure modifier valve 11 and a pressure regulator valve 12 are provided. Solenoid valve 10
Is subjected to duty control as will be described later, and obtains a pilot pressure based on the discharge pressure of the oil pump 8 guided through the orifice 9. The pressure modifier valve 11 amplifies its pilot pressure. The pressure regulator valve 12 regulates the discharge pressure from the oil pump 8 to a line pressure proportional to the pilot pressure from the pressure modifier valve 11, and sends it to a hydraulic circuit such as the torque converter 3 and the hydraulic actuator 5.

Signals are input to the control unit 13 from various sensors. As the various sensors, a hot-wire type air flow meter 14 for detecting the intake air flow rate Q is provided in the intake system of the engine 1. A crank angle sensor 15 is provided on the crankshaft of the engine 1 or a shaft that rotates in synchronization with the crankshaft. The signal from the crank angle sensor 15 is, for example, a pulse signal for each reference crank angle, and the engine speed N is calculated from the period.

Further, the throttle valve of the intake system of the engine 1
A potentiometer type throttle sensor 17 for detecting the opening TVO of 16 is provided. Further, a vehicle speed sensor 18 for detecting a vehicle speed VSP by obtaining a rotation signal from the output shaft 7 of the automatic transmission 2 is provided. Control unit 13
Incorporates a microcomputer and mainly performs shift control and line pressure control.

The shift control is performed in conformity with the operation position of the select lever, and particularly when the select lever is in the D range, the shift control is performed in accordance with the throttle valve opening TVO and the vehicle speed VSP.
The shift position from the 4th speed to the 4th speed is automatically set, and the shift solenoid valve 6
By controlling the ON / OFF combination of A and 6B, the gear type transmission 4 is controlled to the shift position via the hydraulic actuator 5.

The line pressure control is performed by duty-controlling the electromagnetic valve 10 as the line pressure actuator according to the line pressure control routine shown in FIG. Here, the line pressure can be increased by increasing the duty (valve opening time ratio). Next, the line pressure control routine of FIG. 3 will be described.

In step 1 (denoted as S1 in the drawing, the same applies hereinafter), the intake air flow rate Q detected based on the signal from the air flow meter 14 is read. This portion corresponds to the intake air flow rate detecting means together with the air flow meter 14. In step 2, the engine speed N calculated based on the signal from the crank angle sensor 15 is read. This portion corresponds to the engine speed detection means together with the crank angle sensor 15, and in the present embodiment, since the engine speed is detected as the intake charge state of the engine, this part also corresponds to the intake charge state detection means. .

In step 3, the constant K is set from the engine speed N by searching with reference to a map in which the value of the constant K is predetermined according to the engine speed N as a parameter of the intake charge state. This part corresponds to the constant variable means. Here, according to the engine speed N, there is a relationship as shown in FIG. 4 between the intake air amount (Q / N) per unit rotation and the engine torque TQ depending on the engine speed N. Have been confirmed by. This is because the intake charging efficiency changes depending on the engine speed N.

In step 4, the intake air flow rate Q and the engine rotation speed N are used to determine the intake air amount per unit rotation (Q /
N) and a constant K, the engine torque TQ = K
-Calculate Q / N. This portion corresponds to the engine torque calculation means. In step 5, the optimum line pressure PL is set almost proportional to the engine torque TQ by referring to a predetermined map, and the line pressure PL is set by searching. This part corresponds to the line pressure setting means.

The line pressure map is divided into a normal time map used during non-shifting and a shift time map used during shifting, and the shift time map is a type of shift (first speed → second speed, A plurality of them are provided for each of the 2nd speed → the 3rd speed. Then, the routine proceeds to step 6, where the duty corresponding to this line pressure PL is output and the electromagnetic valve 10 is driven to obtain the optimum line pressure. This portion corresponds to the line pressure control means.

In this embodiment, the intake charge state of the engine is detected by the engine speed N. However, if the intake manifold volume variable device is provided and the intake charge state changes by this. Alternatively, the value of the constant K may be changed by detecting the state of the device (the valve thereof).

[0027]

As described above, according to the first aspect of the present invention, the engine torque is detected in consideration of the intake charge state of the engine, so that the engine torque can be detected accurately and an expensive device can be provided. The effect that it is not necessary and matching can be performed with a small number of man-hours can be obtained.

According to the third aspect of the invention, there is an effect that the line pressure control can be made more appropriate by accurately detecting the engine torque. Further, according to the second and fourth aspects of the invention, by detecting the engine speed as the intake charge state of the engine, there is an effect that it can be implemented inexpensively without requiring a special sensor.

[Brief description of drawings]

FIG. 1 is a functional block diagram showing the configuration of the present invention.

FIG. 2 is a system diagram showing an embodiment of the present invention.

FIG. 3 is a flowchart of a line pressure control routine.

FIG. 4 is a diagram showing a relationship between Q / N and torque.

[Explanation of symbols]

 1 Engine 2 Automatic Transmission 8 Oil Pump 10 Electromagnetic Valve 11 Pressure Modifier Valve 12 Pressure Regulator Valve 13 Control Unit 14 Air Flow Meter 15 Crank Angle Sensor

Claims (4)

[Claims] 1. An intake air flow rate detecting means for detecting an intake air flow rate Q of an engine, an engine speed detecting means for detecting an engine speed N, and an intake air flow rate Q and an engine speed N, TQ = K ·
Q / N (K is a constant)
In an engine torque detecting device comprising: an engine torque calculating means for calculating Q; and an intake charge state detecting means for detecting an intake charge state of the engine, and a constant K in the engine torque calculation formula based on the detected intake charge state. An engine torque detection device, comprising: a constant variable means for changing the. 2. The engine torque detecting device according to claim 1, wherein the intake charge state detection means detects an engine speed as an intake charge state of the engine. 3. An intake air flow rate detecting means for detecting an intake air flow rate Q of the engine, an engine speed detecting means for detecting an engine speed N, and an intake air flow rate Q and an engine speed N, TQ = K ·
Q / N (K is a constant)
An engine torque calculating means for calculating Q, a line pressure setting means for setting a line pressure based on the calculated engine torque, and a line pressure actuator based on the set line pressure to drive a line pressure of the automatic transmission. In an automatic transmission line pressure control device including: a line pressure control means for controlling the intake air charging state detection means for detecting an intake air charging state of the engine; An automatic transmission line pressure control device comprising: a constant variable means for changing the constant K; 4. The automatic transmission line pressure control device according to claim 3, wherein the intake charge state detection means detects an engine speed as an intake charge state of the engine.