JP2002130460A - Control device for automatic transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a flat battery by current-carrying to solenoid valves of an automatic transmission. SOLUTION: The current-carrying to the respective solenoid valves 22 to 24 of a hydraulic control circuit 17 is prohibited in a period when an engine speed detected by an engine speed sensor 27 is lower than a prescribed engine speed (a minimum engine speed at which an engine can continuously rotates or an engine speed not more than that speed). Thus, even if an ignition switch is turned on and a power source of a control system is turned on, an electric current is not carried to the solenoid valves 22 to 24 in a period up to starting power generation by a generator after starting the engine, and then, after starting the power generation by the generator by starting (or restarting) the engine, the current-carrying to the solenoid valves 22 to 24 is started to prevent consumption of battery power by the current-carrying to the solenoid valves 22 to 24 before starting. When an engine speed sensor 27 is abnormal, and at low oil temperature time when responsiveness of hydraulic control reduces, the current-carrying to the solenoid valves 22 to 24 is not prohibited.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for an automatic transmission in which the driving oil pressure of an automatic transmission for a vehicle is controlled by an electromagnetic valve.

[0002]

2. Description of the Related Art In recent years, electronically controlled automatic transmissions in which a drive hydraulic pressure is controlled by an electromagnetic valve to change gears are often used for automatic transmissions for vehicles. This electronically controlled automatic transmission
For example, as shown in Japanese Patent No. 2912009, hydraulic pressure is supplied from a hydraulic pump driven by an engine to a hydraulic circuit of an automatic transmission, and a plurality of solenoid valves in the hydraulic circuit are controlled to thereby control the automatic transmission. The gear ratio is switched by controlling the driving oil pressure. In such an automatic transmission, when the ignition switch is turned on and the power of the control system is turned on, power is immediately supplied to each solenoid valve in the hydraulic circuit.

[0003]

As described above, in the conventional automatic transmission, the energization of each solenoid valve in the hydraulic circuit is started immediately after the ignition switch is turned on. Therefore, the engine is turned on after the ignition switch is turned on. It is necessary to energize each solenoid valve only by the charging power of the battery during the period from when the power is started to when the power generation is started by the generator. Normally, the engine is started immediately after the ignition switch is turned on and the generator starts generating electricity.Therefore, there is no problem of battery power consumption due to energization of each solenoid valve before the engine is started. The hydraulic circuit of the automated transmission uses a large number of solenoid valves with a current consumption of about 1 A and consumes a large amount of power. Therefore, the ignition switch is turned on and the engine is started by carelessness of the driver. If the state where the battery does not exist continues for a long time, the power to the solenoid valve may be depleted of battery power, which may cause a so-called dead battery, and the engine cannot be started. Such a problem occurs not only when the engine is started, but also when the engine stall (so-called engine stall) frequently occurs, the engine stall state continues for a long time, or when the engine key is moved to the accessory position (ACC) during parking.
When the engine key is turned to the position (ON position) by mistake, the engine key may be left in a state of being turned to the ON position (ON position) of the ignition switch.

[0004] As a well-known document related to solenoid valve control, there is JP-A-11-336578. In this publication, the engine startability is improved by controlling the energization of each solenoid valve in the hydraulic circuit to reduce the engine load until the engine start is completed, so as to suppress the hydraulic pressure supplied to the transmission. Although a technique has been proposed, in the technique disclosed in this publication, it is necessary to energize each solenoid valve in the hydraulic circuit during a period from when an ignition switch is turned on to when engine start is completed. The problem remains that it is possible.

SUMMARY OF THE INVENTION The present invention has been made in view of such circumstances, and therefore has as its object the control of an automatic transmission capable of preventing the battery from running down due to energization of a solenoid valve for hydraulic control. It is to provide a device.

[0006]

According to a first aspect of the present invention, there is provided a control apparatus for an automatic transmission, wherein an engine rotational speed detected by an engine rotational speed detecting means is controlled to a predetermined rotational speed (when the engine is at a predetermined speed). When the rotation speed is lower than the minimum rotation speed that can continue to rotate (or the rotation speed lower than the minimum rotation speed), the power supply to the electromagnetic valve is prohibited by the power supply prohibition means. In this way, even when the ignition switch is turned on and the power supply of the control system is turned on, the time until the engine is started (or restarted from the engine stall state) and power generation is started by the generator is started. During the period, the solenoid valve is not energized, and thereafter, after the engine is started (or restarted) and power generation is started by the generator, energization of the solenoid valve is started. Thus, it is possible to prevent the battery power from being consumed by energizing the solenoid valve before starting (or before restarting), and even if the ignition switch is turned on and the engine is not started for a long time,
The battery can be prevented from running out.

[0007] In the event that the engine rotational speed detecting means becomes abnormal during engine operation and the detected rotational speed of the engine rotational speed detecting means abnormally decreases, the above-described electromagnetic valve energization prohibition condition (engine rotational speed detection value May be lower than a predetermined rotation speed). If the energization of the solenoid valve is prohibited, the automatic transmission may not be able to shift during traveling.

Therefore, the presence or absence of an abnormality in the engine rotational speed detecting means is determined by the abnormality diagnosing means, and when it is diagnosed that the engine rotational speed detecting means is abnormal, energization of the solenoid valve is prohibited. It is better not to do it. In this way, even if the engine rotational speed detecting means becomes abnormal during engine operation and the solenoid valve energization prohibition condition is satisfied, energization of the solenoid valve is not inhibited, and the shift operation of the automatic transmission is performed. Can be controlled.

By the way, when the temperature of the hydraulic oil of the automatic transmission is low, the viscosity of the hydraulic oil increases (the fluidity deteriorates), and the responsiveness of the hydraulic control by the solenoid valve decreases. For this reason, at low oil temperature, if energization of the solenoid valve is prohibited until engine start is completed and energization of the solenoid valve is started after the start is completed, the hydraulic pressure inside the automatic transmission is appropriately controlled immediately after the start. When the driver operates the shift lever immediately after the start, the shift operation may be delayed.

As a countermeasure, the oil temperature of the automatic transmission is detected or estimated by an oil temperature detecting means, and when the oil temperature is lower than a predetermined temperature, energization of the solenoid valve is not prohibited. It is good to do. With this configuration, at a low oil temperature at which the responsiveness of the hydraulic control is reduced, when the ignition switch is turned on and the power supply of the control system is turned on,
Immediately after the energization of the solenoid valve is started, even at a low oil temperature, the automatic transmission can be shifted normally immediately after the start.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. First, a schematic configuration of the automatic transmission 11 will be described with reference to FIGS. As shown in FIG. 2, an input shaft 13 of a torque converter 12 is connected to an output shaft of an engine (not shown), and an output shaft 14 of the torque converter 12 is connected to a hydraulically driven transmission gear mechanism 15.
Are connected. Inside the torque converter 12,
A pump impeller 31 and a turbine runner 32 that constitute a fluid coupling are provided to face each other, and a stator 33 that rectifies the flow of oil is provided between the pump impeller 31 and the turbine runner 32. Further, the torque converter 12 is provided with a lock-up clutch 16 for fastening or disconnecting between the input shaft 13 side and the output shaft 14 side. The output torque of the engine is transmitted to the transmission gear mechanism 15 via the torque converter 12, is shifted by a plurality of gears (e.g., planetary gears) of the transmission gear mechanism 15, and is transmitted to driving wheels (front wheels or rear wheels) of the vehicle. Is done.

The transmission gear mechanism 15 has a plurality of clutches C
0, C1, C2 and brakes B0, B1. These clutches C0, C1, C2 and brakes B0, B1 are provided.
The gear ratio is switched by switching the engagement / disengagement by hydraulic pressure to switch the combination of gears.

As shown in FIG. 1, the transmission gear mechanism 15 is provided with a hydraulic pump 18 driven by engine power, and an oil pan (not shown) for storing hydraulic oil is provided in the transmission gear mechanism 15.
A hydraulic control circuit 17 is provided. The hydraulic control circuit 17 includes a line pressure control circuit 19, an automatic speed change control circuit 2
0, a lock-up control circuit 21, a manual switching valve 26, and the like. Supplied.
The line pressure control circuit 19 includes a line pressure control solenoid valve 2 for controlling the hydraulic pressure from the hydraulic pump 18 to a predetermined line pressure.
The automatic transmission control circuit 20 includes clutches C0, C1, C2 of the transmission gear mechanism 15 and brakes B
A plurality of shift electromagnetic valves 23 for controlling the oil pressure supplied to 0 and B1 are provided. Further, the lock-up control circuit 21 is provided with a lock-up control solenoid valve 24 for controlling the hydraulic pressure supplied to the lock-up clutch 16.

Between the line pressure control circuit 19 and the automatic transmission control circuit 20, there is provided a manual switching valve 26 which is switched in conjunction with the operation of the shift lever 25.
When the shift lever 25 is operated in the neutral range (N range) or the parking range (P range), even if the power supply to the shift solenoid valve 23 is stopped (OFF), the shift gear is operated by the manual switching valve 26. Mechanism 15
Is switched so that the transmission gear mechanism 15 is in a neutral state.

As a fail-safe in the event of an abnormality in the electric system such as disconnection of the solenoid valve driving circuit, each of the shifting solenoid valves 23 causes the transmission gear mechanism 15 to operate at a specific speed ratio by means of a spring or the like when power supply is stopped. (For example, third speed) so that the vehicle can run at a specific gear ratio even when the power to the electromagnetic valve 23 for gear shifting is cut off. Further, the line pressure control solenoid valve 22 is configured to be switched to a position where the line pressure is set to the maximum pressure by a spring or the like when power supply is stopped. The line pressure is supplied to the automatic transmission control circuit 20 so that the clutch C
0, C1, C2 and the brakes B0, B1 are prevented from slipping to prevent burn-in. The lock-up control solenoid valve 24 is configured to be switched to a position where the lock-up clutch 16 is released by a spring or the like when the power supply is stopped.

On the other hand, the engine has an engine rotation speed N
e is provided with an engine speed sensor 27 (engine speed detection means) for detecting the rotation speed e.
An input shaft rotation speed sensor 28 for detecting an input shaft rotation speed Nt of the transmission gear mechanism 15 (an output shaft rotation speed of the torque converter 12), and an output shaft rotation speed No of the transmission gear mechanism 15
An output shaft rotation speed sensor (vehicle speed sensor) 29 for detecting (vehicle speed V) is provided.

The output signals of these various sensors are sent to an automatic transmission electronic control circuit (hereinafter referred to as "AT-ECU") 3.
Input to 0. The AT-ECU 30 is mainly composed of a microcomputer, and has a built-in ROM.
The shift control and the lock-up control of the automatic transmission 11 are executed by executing various control programs stored in the (storage medium).

The AT-ECU 30 operates according to the operating position of the shift lever 25 and operating conditions (throttle opening, vehicle speed, etc.) so that the speed of the transmission gear mechanism 15 is changed according to the previously set shift pattern of FIG. By controlling energization of the electromagnetic valves 23 for shifting and controlling hydraulic pressures applied to the clutches C0, C1, C2 and the brakes B0, B1 of the shifting gear mechanism 15, the shifting operation of the shifting gear mechanism 15 is performed. Control. Further, the AT-ECU 30 controls the energization of the solenoid valve 22 for line pressure control and the solenoid valve 24 for lock-up control in accordance with the operation position of the shift lever 25 and operating conditions, thereby controlling the line pressure and the lock-up clutch 16. Control of the engagement / disengagement operation.

By the way, when energization of each of the solenoid valves 22 and 23 is started from the time when an ignition switch (not shown) is turned on and the power supply of the system is turned on, the engine is started after the ignition switch is turned on. Until the generator (not shown) starts generating electricity,
It is necessary to energize each of the solenoid valves 22 and 23 only with the electric power stored in the battery (not shown). For this reason, if the engine is not started (or restarted) for a long time with the ignition switch turned on, the power to the solenoid valves 22 and 23 may drain the battery power and cause the battery to run down. is there.

The AT-ECU 30 executes the solenoid valve control program shown in FIG. 3 so that the engine rotation speed Ne is reduced to a predetermined rotation speed Neo (the minimum rotation speed at which the engine can continue to run or a rotation speed lower than the minimum rotation speed Neo). During a period lower than (), the power supply to the solenoid valves 22 to 24 is prohibited, and after the engine start is completed and power generation is started by the generator, the power supply to the solenoid valves 22 to 24 is started.

In this case, before starting the engine, the solenoid valves 22 to
Even if the power supply to the motor 24 is prohibited, the shift lever 25 is operated to the parking range (P range) or the neutral range (N range) before the engine is started. The oil pressure is switched so that the transmission gear mechanism 15 is in the neutral state. For this reason, even if energization of the electromagnetic valves 22 to 24 is prohibited before the engine is started, power is prevented from being transmitted to the drive wheels via the transmission gear mechanism 15 when the engine is started. Further, after the engine is started, there is some time before the driver operates the shift lever 25 from the parking range (P range) or the neutral range (N range) to the drive range (D range). Even if the energization of the solenoid valves 22 to 24 is started, the clutches C0, C1, C2 and the brakes B0, B1 of the transmission gear mechanism 15 are not changed until the driver operates the shift lever 25 to the drive range (D range). The supplied hydraulic pressure can be controlled appropriately.

The solenoid valve control program shown in FIG. 3 is started at the same time when the ignition switch is turned on, and is executed at predetermined time intervals. When the program is started, first, in step 101, the engine speed Ne detected by the engine speed sensor 27 is read, and in the next step 102
Then, it is determined whether or not the response time of the hydraulic control is low at the time of low oil temperature based on whether or not the temperature (oil temperature) of the hydraulic oil is lower than a predetermined temperature. At this time, the oil pressure may be actually detected by an oil temperature sensor, or the oil temperature may be estimated from a cooling water temperature, an intake air temperature, or the like. This function corresponds to the oil temperature detecting means in the claims.

If it is determined in step 102 that the oil temperature is low, the responsiveness of the hydraulic control by each of the solenoid valves 22 to 24 is poor, so the routine proceeds to step 106 where normal solenoid valve control is performed and the engine is controlled. Even before starting, each solenoid valve 22 ~
The energization control of 24 is started.

On the other hand, if it is determined in step 102 that the oil temperature is not low (the oil temperature is equal to or higher than a predetermined temperature), it is determined that the responsiveness of the hydraulic control by the solenoid valves 22 to 24 is good. Then, the program proceeds to a step 103, wherein it is determined whether or not the engine speed sensor 27 is normal. This determination is made based on a diagnosis result of an abnormality diagnosis program (abnormality diagnosis means) for monitoring the presence or absence of an abnormality in the engine speed sensor 27. Before starting the engine, it is determined whether or not the engine speed sensor 27 is normal based on data stored in the diagnosis result performed during the previous operation of the engine. In addition, during the operation of the engine, it is determined whether or not the engine speed sensor 27 is normal based on the latest diagnosis result performed during the operation of the engine. Note that the abnormality determination method of the engine rotation speed sensor 27 is such that, for example, when the vehicle is running with the accelerator depressed, whether the engine rotation speed sensor 27 outputs a pulse signal is determined to be normal / abnormal. Is also good. In addition, any known method may be adopted as a method for determining an abnormality in the engine rotation speed sensor 27.

If it is determined in step 103 that the engine speed sensor 27 is normal, the next step 104
It is determined whether the engine speed Ne detected by the engine speed sensor 27 is lower than a predetermined speed Neo. Here, the predetermined rotation speed Neo is set to a minimum rotation speed at which the engine can continue to rotate (for example, a start completion determination rotation speed) or a lower rotation speed. If the engine rotation speed Ne is lower than the predetermined rotation speed Neo, even if the engine is currently running, the engine will stall immediately and cannot be generated by the generator. Prohibition of energization. The processing of step 105 plays a role corresponding to the power supply prohibition means described in the claims.

Thereafter, when the engine is started (or restarted) and the engine rotation speed Ne becomes equal to or higher than the predetermined rotation speed Neo, it is determined that power generation has been started by the generator, and the routine proceeds to step 106. Of the solenoid valves 22 to 24 to start the energization control of the solenoid valves 22 to 24.

On the other hand, if it is determined in step 103 that the engine rotation speed sensor 27 is abnormal, it is not possible to correctly determine whether the engine rotation speed Ne is lower than the predetermined rotation speed Neo. Without performing the processing, the process proceeds to step 107, where the control at the time of the sensor abnormality is performed and appropriate processing is performed, and then this program is terminated. In this control when the sensor is abnormal, energization of each of the solenoid valves 22 to 24 is not prohibited.

According to the embodiment described above, while the engine speed Ne is lower than the predetermined speed Neo (the minimum speed at which the engine can continue to run or at a lower speed), the hydraulic control circuit 17 solenoid valves 2
Since the power supply to 2 to 24 is prohibited, even if the ignition switch is turned on and the system is turned on, the engine is started (or restarted from the engine stall state) and the generator Until power generation is started, the solenoid valves 22 to 24 are not energized. Thereafter, after the engine is started (or restarted) and the generator starts generating power, the solenoid valves 22 to 24 are energized. Will be started. This can prevent battery power from being consumed by energizing the solenoid valves 22 to 24 before starting (or before restarting). Even if the ignition switch is turned on and the engine is not started for a long time, The battery can be prevented from running out.

Further, in this embodiment, when the engine speed sensor 27 becomes abnormal, the energization of the solenoid valves 22 to 24 is not prohibited. 27, the energization of the solenoid valves 22 to 24 is not inhibited, and the shift of the automatic transmission 11 is not stopped even if the solenoid valve energization prohibition condition (the engine rotation speed detection value is lower than the predetermined rotation speed) is satisfied. Operation can be controlled.

By the way, when the temperature of the hydraulic oil is low, the viscosity of the hydraulic oil increases, so that the responsiveness of the hydraulic control by each of the solenoid valves 22 to 24 decreases. Therefore, when the oil temperature is low, the energization of the solenoid valves 22 to 24 is prohibited until the engine start is completed, and the energization of the solenoid valves 22 to 24 is started after the start of the engine is completed. There is a possibility that the control of the hydraulic pressure inside the motor 11 will be delayed, and the gearshift operation will be delayed when the driver operates the shift lever 25 immediately after the start.

As a countermeasure against this, in the present embodiment, at low oil temperature when the responsiveness of the hydraulic control decreases, the solenoid valves 22 to 24
We do not prohibit electricity supply to F. As a result, when the ignition switch is turned on and the system is turned on at low oil temperature, energization of the solenoid valves 22 to 24 is started immediately. Automatic transmission 11 according to the operation of lever 25
Can be shifted normally.

However, when the influence of the decrease in oil temperature is small, as in a vehicle in a warm zone specification, the process of determining whether or not the oil temperature is low (step 102) is omitted, and regardless of the oil temperature,
It may be determined whether or not the energization to the solenoid valves 22 to 24 is prohibited based on whether or not the engine rotation speed Ne is lower than the predetermined rotation speed Neo.

In the above embodiment, the transmission gear mechanism 15 is used as the transmission mechanism of the automatic transmission. However, a continuously variable transmission (CVT) may be used. In addition, the present invention may be applied to an automatic transmission having no lock-up mechanism,
The present invention can be applied to various automatic transmissions in which drive hydraulic pressure is controlled by an electromagnetic valve.

[Brief description of the drawings]

FIG. 1 is a diagram showing a schematic configuration of an entire automatic transmission according to an embodiment of the present invention.

FIG. 2 is a diagram schematically showing a mechanical configuration of the automatic transmission.

FIG. 3 is a flowchart showing the flow of processing of a solenoid valve control program;

FIG. 4 is a diagram showing an example of a shift pattern.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 11 ... Automatic transmission, 12 ... Torque converter, 13 ... Transmission gear mechanism, 16 ... Lock-up clutch, 17 ... Hydraulic control circuit, 18 ... Hydraulic pump, 19 ... Line pressure control circuit, 20 ... Automatic transmission control circuit, 21 ... Lock-up control circuit, 22: solenoid valve for line pressure control, 23: solenoid valve for speed change, 24: solenoid valve for lock-up control, 26: manual switching valve, 27: engine speed sensor (engine speed detection Means), 30... AT-ECU (power supply prohibition means, power supply prohibition canceling means, abnormality diagnosis means), C0 to C2.
Clutch, B0, B1 ... brake.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3J552 MA02 MA12 NA01 NB01 PB03 QA26A QB08 RC06 SA59 TB13 UA09 VA48W VA48X VB01Z VC01W VC01X VC03Z

Claims (3)

[Claims] An automatic transmission control device for controlling the drive oil pressure of an automatic transmission for a vehicle by an electromagnetic valve, wherein the engine rotational speed is detected by the engine rotational speed detecting means, and the engine rotational speed is detected by the engine rotational speed detecting means. A control device for an automatic transmission, comprising: an energization inhibiting unit that inhibits energization of the solenoid valve when the engine rotation speed is lower than a predetermined rotation speed. 2. An abnormality diagnosing means for judging the presence or absence of an abnormality in the engine rotational speed detecting means, wherein the energization inhibiting means is configured to execute the abnormality detecting means when the abnormality diagnosing means diagnoses that the engine rotational speed detecting means is abnormal. The control device for an automatic transmission according to claim 1, wherein energization of the solenoid valve is not prohibited. 3. An oil temperature detecting means for detecting or estimating an oil temperature of the automatic transmission, wherein the energization prohibiting means is provided when the oil temperature detected or estimated by the oil temperature detecting means is lower than a predetermined temperature. 2. The method according to claim 1, wherein energization of the solenoid valve is not prohibited.
Or the control device for an automatic transmission according to 2.