JP2763554B2 - Engine control device for vehicles with torque converter - Google Patents

Description

The present invention relates to an engine control device of a vehicle equipped with a torque converter.

(Prior Art) In recent years, there has been a tendency to increase the output of an automobile engine by installing a supercharger (for example, see Japanese Patent Application Laid-Open No. 61-27).
No. 2420).

On the other hand, in automobiles, it has been widely attempted to provide an automatic transmission with a torque converter from the viewpoint of eliminating the inconvenience of the shifting operation and simplifying the driving operation. High-performance vehicles combined with supercharged engines are becoming mainstream.

(Problems to be Solved by the Invention) By the way, in a vehicle in which an automatic transmission with a torque converter is combined with an engine, in particular, a vehicle in which an engine is provided with a supercharger, the driving system is large and heavy due to the following reasons. It is feared that problems such as deterioration of fuel consumption performance or acceleration performance in a practical range due to the formation of a fuel cell or deterioration of durability of a drive system may occur.

That is, in the torque converter, as shown in FIG. 5, the torque ratio (ie, the ratio between the turbine shaft torque and the pump shaft torque) in a region where the speed ratio (ie, the ratio between the turbine speed and the pump speed) is low. Is increased, so-called torque increasing action is generated. This torque increasing action occurs in a stall region where the speed ratio is close to zero, specifically, at the time of starting acceleration or climbing a steep uphill, and the torque ratio is 2-3 times that at the time of normal running. Also. Therefore, for example, when a large output due to the supercharging effect is input from the engine side at such a high torque ratio (low speed ratio), two to three times the torque is transmitted to the drive system. As a result, the durability of the drive system is impaired by the load of excessive transmission torque, and if the drive system is increased in strength to withstand this large transmission torque, the size of the drive system is increased due to its large size and heavy weight. As a result, problems such as deterioration of fuel consumption performance and deterioration of acceleration performance occur.

Therefore, the present invention reduces the engine output itself when excessive torque is likely to be transmitted to the drive system due to the torque increasing effect of the torque converter, thereby preventing the transmission of excessive torque to the drive system, thereby improving the durability of the drive system. It is an object of the present invention to provide an engine control device for a vehicle equipped with a torque converter, which can improve the fuel consumption and maintain the fuel efficiency and acceleration performance of the engine at a high level.

(Means for Solving the Problems) The present invention employs the following configurations as means for solving such problems as shown in FIG.

According to the first aspect of the present invention, in an engine control device of a vehicle equipped with a torque converter equipped with a supercharged engine that transmits an output to a transmission mechanism via a torque converter, a value related to a torque ratio of the torque converter is detected. A torque ratio detecting means 51, an engine output detecting means 52 for detecting an engine output, and a value relating to the torque ratio and the engine output based on a detection result of the torque ratio detecting means 51 and the engine output detecting means 52. Determining means 53 for determining that the combination is in a state where it is necessary to reduce the engine output in order to improve the durability of the speed change mechanism, and when the determining means 53 determines that the state is the above, when not determining In contrast, a control means 54 for reducing the supercharging pressure by the supercharger is provided.

According to the second aspect of the present invention, in an engine control device for a vehicle equipped with a torque converter equipped with an engine for transmitting an output to a transmission mechanism via a torque converter, a torque ratio detecting means for detecting a value relating to a torque ratio of the torque converter. 51, an engine output detecting means 52 for detecting an engine output, and a combination of a value relating to the torque ratio and the engine output based on a detection result of the torque ratio detecting means 51 and the engine output detecting means 52. Determining means 53 for determining that the engine output needs to be reduced in order to improve the durability of the mechanism; and, when the determining means determines that the state is the above state, the engine output is reduced as compared with the non-determined state. Control means 54 for lowering the temperature.

(Operation and Effect of the Invention) With the present invention, the following effects can be obtained by adopting such a configuration.

According to the engine control device for a vehicle equipped with the torque converter according to the first aspect, the combination of the value related to the torque ratio and the engine output indicates that the engine output needs to be reduced in order to improve the durability of the transmission mechanism. When the determination is made, the supercharging pressure is reduced as compared with the non-determined state, and the engine output is reduced accordingly. Therefore, transmission of excessive torque to the drive system is prevented beforehand. As a result, the durability of the drive system can be improved without increasing the strength of the drive system, and the increase in the strength of the drive system can be prevented from increasing the size and weight, so that the fuel consumption performance and acceleration performance in the normal range are maintained at a high level. And the like.

According to the engine control device for a vehicle equipped with a torque converter, the combination of the value related to the torque ratio and the engine output is a state in which it is necessary to reduce the engine output in order to improve the durability of the transmission mechanism. When the determination is made, the engine output is reduced as compared with when the determination is not made, so that the transmission of excessive torque to the drive system is prevented beforehand. As a result, the durability of the drive system can be improved without increasing the strength of the drive system, and the increase in the strength of the drive system can be prevented from increasing the size and weight, so that the fuel consumption performance and acceleration performance in the normal range are maintained at a high level. And the like.

(Embodiment) Hereinafter, a preferred embodiment of the present invention will be described with reference to FIG. 2 to FIG.

FIG. 2 shows an entire system of an engine control device for a vehicle equipped with a torque converter according to an embodiment of the present invention. In FIG. 2, reference numeral 1 denotes an engine, and 2 denotes a turbine including a turbine 21, a pump 22, and a stator 23. Torque converter, 3
Is a transmission, and the torque converter 2
The transmission 3 comprises the automatic transmission 4. A supercharger 5 composed of a roots blower is provided in an intake passage 6 of the engine 1, and a throttle valve 10 is provided upstream of the supercharger 5. Further, a relief valve 8 that controls a supercharging pressure by opening and closing the bypass passage 7 is provided in a bypass passage 7 that bypasses the supercharger 5 (in this embodiment, the relief valve 8 is a device in the scope of claims). Which constitutes the control means).

Note that the relief valve 8 is driven by an actuator 9 which operates in response to a control signal S _A from the controller 11 to be described later.

The controller 11 controls the supercharging pressure of the intake air absorbed by the engine 1 by controlling the relief valve 8 as described later, thereby preventing excessive torque from being transmitted from the engine 1 to the drive system. It is for, as a control factor, the engine speed Ne from the engine speed sensor 15 provided in the engine 1, the pressure sensor 14 provided in the intake system supercharging pressure P _B is also the torque converter 2 A pump speed _NP and a turbine speed _NT are respectively input from the provided first speed sensor 12 and second speed sensor 13.

Next, the actual control of the engine by the controller 11 will be described in the third section.
Prior to this, the basic concept of the control will be described with reference to FIGS. 4 and 5.

The torque converter 2 performs a torque increasing action in a low speed ratio range (see FIG. 5). In a range where the torque increasing action is large, a high level engine output obtained from the engine 1 by a supercharging effect is generated. As described above, when the torque is input to the torque converter 2 side, an excessive torque of two to three times the engine output is transmitted to the drive system, and the durability of the drive system is impaired. It is on the street.

Therefore, in this embodiment, an operating region where excessive torque may be transmitted to the drive system, specifically, as shown in FIG. 5, the speed ratio is equal to or less than the set value e ^* , that is, the torque ratio is set to the set value. When the engine output is in a high output range of τ ^* or higher and the engine output is higher than the set value Pt ^* , that is, in a high boost pressure range, as shown in FIG. The supply pressure is reduced to suppress the engine output itself, thereby preventing excessive torque from being transmitted to the drive system. In this embodiment, the "speed ratio" corresponds to the "value relating to the torque ratio" in the claims.

Next, the actual operation of this control will be described with reference to FIG.
Read After control starts, first in step S ₁ the current turbine speed N _T and the pump rotational speed N _P and the engine speed Ne and the boost pressure P _B, respectively. Next, the calculating the turbine speed N _T and the current speed ratio e of the pump speed N _P and the torque converter 2 from (Step S _2), the engine speed
Ne and calculates the current engine output Pt from the supercharging pressure P _B (step S _3).

Then, then the current speed ratio e and the set speed ratio e ^* and the current engine output Pt setting engine output Pt ^* and the respectively compared (Step S _4, step S _5), "e ≦
e ^* ”and“ Pt ≧ Pt ^* ”(ie, when excessive torque is expected to be transmitted to the drive system), the opening of the relief valve 8 is increased by a small opening Δθ, and reducing the Kyu圧achieve control of engine output (step S _6).

On the other hand, in cases other than the above, it is determined that there is no possibility of transmission of excessive torque to the drive system, and the opening of the relief valve 8 is not adjusted.

As described above, by performing the opening adjustment of the relief valve 8 in relation to the speed ratio (that is, the torque ratio) of the torque converter 2 and the engine output, transmission of excessive torque to the drive system is reliably prevented, whereby the drive is performed. This ensures the durability of the system. In addition, since it is not necessary to increase the strength of the drive system, deterioration of fuel consumption performance or acceleration performance in a steady range due to an increase in the size and weight of the drive system is prevented.

In this embodiment, the control range of the supercharging pressure by the relief valve 8 is defined by the speed ratio of the torque converter 2 (that is, the torque ratio).
And the engine output, but the present invention is not limited to this. For example, the allowable transmission torque to the drive system is determined in advance, and the torque ratio of the torque converter 2 and the engine output are determined. The opening degree of the relief valve 8 may be adjusted only when the actual transmission torque obtained based on the correlation of (1) exceeds this allowable transmission torque. In this case, there is no supercharging pressure control in an unnecessary region, and it is particularly advantageous in terms of maintaining engine performance.

[Brief description of the drawings]

1 is a diagram corresponding to the claims of the present invention, FIG. 2 is an overall system diagram of a vehicle equipped with a torque converter having an engine control device according to an embodiment of the present invention, FIG. 3 is a control flowchart of the engine control device, FIG. 4 is an engine output characteristic diagram, and FIG. 5 is a correlation diagram between a speed ratio and a torque ratio of the torque converter. DESCRIPTION OF SYMBOLS 1 ... Engine 2 ... Torque converter 3 ... Transmission 4 ... Automatic transmission 5 ... Supercharger 6 ... Intake passage 7 ... Bypass passage 8 ... Relief valve 9 ... Actuator 10 ... Throttle valve 11 …… Controller 12,13 …… Rotation speed sensor 14 …… Pressure sensor 15 …… Engine rotation speed sensor

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Claims (2)

(57) [Claims] 1. An engine control device for a vehicle equipped with a torque converter having an engine with a supercharger for transmitting an output to a transmission mechanism via a torque converter, the torque ratio detecting a value relating to a torque ratio of the torque converter. Detecting means; an engine output detecting means for detecting an engine output; and a combination of a value relating to the torque ratio and the engine output based on a detection result of the torque ratio detecting means and the engine output detecting means. Discriminating means for discriminating that the engine output needs to be reduced to improve durability; and when the discriminating means discriminates that the state is as described above, the supercharger by the turbocharger as compared with the non-discriminating state. An engine control device for a vehicle equipped with a torque converter, comprising: control means for reducing a supply pressure. 2. An engine control device for a vehicle equipped with a torque converter having an engine for transmitting an output to a transmission mechanism via a torque converter, comprising: a torque ratio detecting means for detecting a value relating to a torque ratio of the torque converter; An engine output detecting means for detecting an engine output; and a combination of a value relating to the torque ratio and the engine output based on a detection result of the torque ratio detecting means and the engine output detecting means, thereby improving the durability of the transmission mechanism. Determining means for determining that the engine output needs to be reduced in order to cause the engine output to decrease, and control means for reducing the engine output when the determining means determines that the state is the above state, as compared to a non-determining state. An engine control device for a vehicle equipped with a torque converter.