JP2002276790A - Hydraulic control device for automatic transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To avoid the sliding of a friction engagement element to be generally fastened while allowing efficient air exhaustion, during air exhaustion control for supplying hydraulic pressure to a hydraulic circuit for the friction engagement element to be released and exhausting an air. SOLUTION: When the hydraulic pressure is supplied for air exhaustion, the minimum engine speed is set in response to an oil temperature. When an actual engine speed is lower than the minimum engine speed, the engine speed is increased. Thus, the delivery of an oil pump to be driven by an engine is kept as required.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulic control device for an automatic transmission, and more particularly, to a hydraulic control for discharging air mixed in a hydraulic circuit.

[0002]

2. Description of the Related Art Conventionally, in a hydraulic control device of an automatic transmission for hydraulically controlling the engagement and release of a friction engagement element, a friction engagement to be released from a request for a shift speed during non-shifting. There is known a configuration in which hydraulic pressure is supplied to an element (clutch) within a range in which a piston does not stroke to discharge air mixed in a hydraulic circuit (see Japanese Patent Application Laid-Open No. H10-169765).

[0003]

In the above-described air discharge control, the hydraulic pressure is supplied to the frictional engagement element to be released from the request for the shift speed at that time. If a large amount of oil is supplied to discharge air during idling operation in which the discharge rate of the pump decreases, slippage may occur due to insufficient oil supplied to the friction engagement element that should be engaged. In addition, if the amount of oil supplied for air discharge is suppressed in order to avoid the occurrence of the slip, there is a problem that air cannot be discharged efficiently.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has a hydraulic control of an automatic transmission capable of efficiently discharging air while avoiding the occurrence of slippage of a frictional engagement element to be originally engaged. It is intended to provide a device.

[0005]

According to the first aspect of the present invention, a hydraulic pressure is supplied to a frictional engagement element to be released at a current shift speed during non-shifting, so that the hydraulic pressure is mixed into a hydraulic circuit. In the hydraulic control device for an automatic transmission that discharges air, the discharge amount of an oil pump that supplies oil to the automatic transmission is increased when hydraulic pressure for discharging the air is supplied.

According to such a configuration, by increasing the discharge amount of the oil pump at the time of supplying the hydraulic pressure for discharging the air, even if a part of the oil discharged from the oil pump is used for discharging the air, The required amount for the frictional engagement element to be fastened is ensured. According to the second aspect of the present invention, the hydraulic pressure is supplied to the frictional engagement element to be released at the current shift speed during non-shifting, so that the hydraulic pressure of the automatic transmission that discharges the air mixed in the hydraulic circuit is released. The control device is configured to increase the discharge amount when the discharge amount of the oil pump that supplies oil to the automatic transmission is smaller than the minimum required amount at the time of supplying hydraulic pressure for discharging air.

With this configuration, when the actual discharge amount is smaller than the minimum required amount, which is the sum of the necessary amount for the friction engagement element to be originally engaged and the amount of oil for air discharge, the discharge amount To ensure a minimum demand. According to the third aspect of the present invention, the oil pump is driven by an engine combined with the automatic transmission, and when the engine rotation speed is lower than a predetermined minimum rotation speed, the discharge amount of the oil pump is reduced. Is determined to be less than the minimum required amount, and the discharge amount is increased by increasing the engine rotation speed.

According to this configuration, since the oil pump is driven by the engine, the rotational speed of the engine and the rotational speed of the oil pump are in a proportional relationship, and the discharge amount changes according to the rotational speed of the pump. Therefore, when the engine rotation speed is lower than the predetermined minimum rotation speed, it is estimated that the discharge amount of the oil pump is smaller than the minimum required amount, and the discharge amount is increased by increasing the engine rotation speed and increasing the pump rotation speed. To increase.

According to the present invention, the minimum rotation speed is set higher as the temperature of the hydraulic oil of the automatic transmission is lower. According to such a configuration, when the temperature of the hydraulic oil is low and the discharge amount tends to decrease, a higher engine rotation speed is required. According to the fifth aspect of the invention, the engine speed is changed by controlling the intake air amount of the engine.

According to such a configuration, for example, by controlling the opening of the throttle valve or the bypass control valve for controlling the amount of air bypassing the throttle valve, the amount of intake air of the engine is increased, thereby increasing the engine speed. (Oil pump discharge).

[0011]

According to the first aspect of the present invention, when air is discharged, the discharge amount of the oil pump is increased. Therefore, the supply of hydraulic pressure for air discharge allows the friction engagement element to be originally engaged to be engaged. Insufficiency in the hydraulic pressure supply amount can be avoided, and there is an effect that air can be efficiently discharged while avoiding slippage of the friction engagement element.

According to the second aspect of the present invention, the state of insufficient oil supply to the frictional engagement element to be originally tightened is accurately determined by the supply of hydraulic pressure for air discharge, and the state of insufficient oil supply is determined. Can be surely eliminated. According to the third aspect of the invention, there is an effect that it is possible to accurately determine whether the discharge amount is excessive or insufficient from the information on the engine rotation speed, and to secure a required discharge amount.

According to the fourth aspect of the invention, there is an effect that the engine speed can be controlled to a required discharge amount even if the temperature of the hydraulic oil is different. According to the fifth aspect of the invention, there is an effect that the engine rotation speed can be easily changed by the intake air amount control which is a normal engine control, so that the discharge amount of the oil pump can be easily changed.

[0014]

Embodiments of the present invention will be described below. FIG. 1 shows a drive system of a vehicle according to an embodiment. An automatic transmission 3 is connected to an output shaft of an engine 1 via a torque converter 2.
The drive shaft of the vehicle (not shown) is driven to rotate by the output shaft of (1).

FIG. 2 is a skeleton showing a transmission mechanism of the automatic transmission 3. The transmission mechanism includes two sets of planetary gears G1, G2 and three sets of multi-plate clutches (high clutch H
/ C, reverse clutch R / C, low clutch L /
C) One set of brake bands 2 & 4 / B, one set of multiple disc brakes (low & reverse brake L & R / B), and one set of one-way clutch L / OWC.

The two sets of planetary gears G1 and G2 are simple planetary gears including sun gears S1 and S2, ring gears r1 and r2, and carriers c1 and c2, respectively. The sun gear S1 of the planetary gear set G1 has a reverse clutch R /
C is configured to be connectable to the input shaft IN, and is configured to be fixable by the brake bands 2 & 4 / B.

The sun gear S2 of the planetary gear set G2 is directly connected to the input shaft IN. The carrier c1 of the planetary gear set G1 is configured to be able to be coupled to the input shaft IN by a high clutch H / C, while the ring gear r2 of the planetary gear set G2 is connected to the carrier of the planetary gear set G1 by a low clutch L / C. The carrier c1 of the planetary gear set G1 can be fixed by a low & reverse brake L & R / B.

A ring gear r1 of the planetary gear set G1 and a carrier c2 of the planetary gear set G2 are directly connected to the output shaft OUT. In FIG. 2, reference numeral 10 denotes an oil pump that is driven by the engine 1 and supplies hydraulic oil to the automatic transmission. In the transmission mechanism having the above configuration, the first to fourth speeds of forward movement and the reverse R
Is realized by a combination of the engaged and released states of the clutches and brakes (friction engagement elements) as shown in FIG.

In FIG. 3, a circle indicates a fastened state, and a part without a symbol indicates a released state.
The fastening state indicated by a black circle of & R / B indicates fastening only in one range. The engagement / disengagement logic of the friction engagement element is realized by a combination of ON / OFF of the shift solenoid (A) 5 and the shift solenoid (B) 6 inserted in the shift control valve 4 shown in FIG. (See FIG. 4).

A line pressure solenoid 7 is inserted in the control valve 4, and the line pressure of the control valve 4 is controlled by the line pressure solenoid 7. The shift solenoid (A) 5, the shift solenoid (B) 6, and the line pressure solenoid 7 are controlled by an A / T controller 11. The A / T controller 11 includes an engine rotation sensor 12 for detecting a rotation speed Ne of the engine 1, an accelerator opening sensor 13 for detecting an opening APS of an accelerator pedal (not shown), and an automatic transmission fluid (ATF). ,
ATF temperature sensor 1 for detecting the temperature of ATF
4. A detection signal is inputted from a vehicle speed sensor 15, a vehicle speed sensor 15, an inhibitor switch 16 for detecting a range position selected by operating a shift knob, and the like.

The A / T controller 11
While performing normal shift control based on the various detection signals described above, control for discharging air (bubbles) mixed into the hydraulic circuit while the vehicle is idle (hereinafter referred to as air discharge) is performed as described later. Control). An engine controller 21 for controlling the engine 1 is provided. The engine controller 21 receives detection signals from the engine rotation sensor 12, the accelerator opening sensor 13, and the like.

A control signal is output to a motor 9 for opening and closing a throttle valve 8 provided in an intake passage of the engine 1, a fuel injection valve (not shown), and the like. The A / T controller 11 and the engine controller 2
1 is configured to be able to communicate with each other. Here, A
Details of the air discharge control by the / T controller 11
This will be described with reference to the flowchart of FIG.

The program shown in the flowchart of FIG. 5 is executed at predetermined time intervals. First, in step S1, it is determined whether or not a condition for permitting execution of air discharge control is satisfied. For example, the following conditions (1) to (3) are determined as the execution permission conditions (see FIG. 6).

(1) The D range (drive range) is initially switched from the N range (neutral range) after the ignition switch is turned on. (2) Line pressure control (ND select control) performed at a predetermined time immediately after switching from the N range to the D range
Has been completed. (3) 1st gear steady state with no shift request.

If it is determined in step S1 that the execution permission condition is satisfied, the process proceeds to step S2, where the ATF temperature (temperature of the hydraulic oil) is detected based on the detection signal from the ATF temperature sensor 14. In step S3, a table in which the minimum rotation speed corresponding to the ATF temperature (oil temperature) is stored in advance and the minimum rotation speed corresponding to the ATF temperature at that time is searched.

The minimum rotation speed is the minimum value of the engine rotation speed Ne required when executing the air discharge control. Since the oil pump 10 in this embodiment is driven by the engine 1, the minimum rotation speed corresponds to the minimum rotation speed of the oil pump 10, and the discharge amount of the oil pump 10 is determined according to the rotation speed. The minimum rotation speed is set as a value indicating the minimum required discharge amount during the air discharge control.

The minimum rotation speed is set to be higher as the ATF temperature (oil temperature) is lower, and the lowering of the discharge amount as the oil temperature lowers is offset by increasing the pump rotation. I have to do it. In step S4, the actual engine speed Ne at that time is detected from the detection signal of the engine speed sensor 12.

In step S5, it is determined whether or not the actual engine speed Ne detected in step S4 is lower than the minimum speed set in step S3. For example, when the engine 1 is idling and the engine temperature is high and the engine speed is relatively low, it is determined in step S5 that the actual engine speed Ne is lower than the minimum speed. Become.

If it is determined in step S5 that the actual engine rotation speed Ne is lower than the minimum rotation speed, the process proceeds to step S6, where a signal requesting forcibly increasing the throttle opening by a predetermined opening is output. Output to the engine controller 21. The engine controller 21 receiving the request signal outputs a control signal to the motor 9 to increase the throttle opening by a predetermined opening.

By increasing the throttle opening, the amount of intake air of the engine 1 increases, so that the engine rotation speed becomes higher than the minimum rotation speed, and the minimum required amount is secured as the discharge amount of the oil pump 10. Will be done. The minimum rotation speed is set in advance as a value that can ensure the amount of oil that can properly maintain the original engagement state of the friction engagement element while efficiently discharging the air. By performing control to forcibly increase the engine rotation speed when the engine speed falls below the speed, the execution of the air discharge control in a state where the amount of oil is insufficient is avoided, and slippage in the frictional engagement element to be originally engaged is prevented. Occurrence is avoided.

That is, if the air discharge control is performed without performing the above-described engine rotation speed control in a state where the engine rotation speed is lower than the minimum rotation speed, the oil amount becomes insufficient. Is compensated for by an increase in the discharge amount due to the increase in Oil pump 10 as described above
When the discharge amount is secured, the process proceeds to step S7 to execute the air discharge control.

Specifically, the shift solenoid (A)
5 and the shift solenoid (B) 6 are both turned off for a predetermined period of time at regular intervals (see FIG. 6). In the first speed, the shift solenoid (A) 5 and the shift solenoid (B) 6 are both controlled to the ON state, the high clutch H / C is released, and the low clutch L / C is engaged. The state where both the shift solenoid (A) 5 and the shift solenoid (B) 6 are OFF corresponds to the state of the third speed, and at the third speed, the low clutch L / C and the high clutch H
/ C is fastened (see FIGS. 3 and 4).

Accordingly, by periodically switching both the shift solenoid (A) 5 and the shift solenoid (B) 6 to OFF, the high clutch H / C to be released at the first speed
The supply of the hydraulic pressure is periodically repeated for the high clutch H / C, and the air mixed in the hydraulic circuit of the high clutch H / C is discharged by the supply of the hydraulic pressure. In the above embodiment, the intake air amount of the engine 1 is increased by correcting the opening of the throttle valve 8, and the engine speed Ne is increased.
(Discharge amount of the oil pump 10) is increased. For example, a bypass air passage that bypasses the throttle valve 8 is provided, and by controlling the opening of a bypass control valve interposed in the bypass air passage, the bypass air is controlled. In the configuration for controlling the amount, the opening degree of the bypass control valve may be corrected to increase the intake air amount of the engine 1 and increase the engine rotation speed Ne.

Since the rotation speed lower than the minimum rotation speed is limited only at the time of idling operation, the target rotation speed at the time of feedback control of the engine rotation speed at the time of idling operation to the target rotation speed is set at the minimum rotation speed at the time of air discharge control. The configuration may be limited to the above. Further, simply, when performing the air discharge control, the throttle opening (the intake air amount of the engine) may be uniformly increased without determining the engine rotation speed.

[Brief description of the drawings]

FIG. 1 is a system diagram showing a vehicle drive system according to an embodiment.

FIG. 2 is a skeleton diagram showing a transmission mechanism in the embodiment.

FIG. 3 is a diagram showing combinations of engagement states of frictional engagement elements at each shift speed in the embodiment.

FIG. 4 is a diagram showing a combination of ON and OFF of shift solenoids A and B at each shift speed in the embodiment.

FIG. 5 is a flowchart illustrating an embodiment of air discharge control.

FIG. 6 is a time chart showing a hydraulic control state in the air discharge control.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Engine 2 ... Torque converter 3 ... Automatic transmission 4 ... Control valve 5 ... Shift solenoid (A) 6 ... Shift solenoid (B) 7 ... Line pressure solenoid 8 ... Throttle valve 9 ... Motor 10 ... Oil pump 11 ... A / T controller 12 ... Engine rotation sensor 13 ... Accelerator opening sensor 14 ... ATF temperature sensor 15 ... Vehicle speed sensor 16 ... Inhibitor switch 21 ... Engine controller G1, G2 ... Planetary gear H / C ... High clutch R / C ... Reverse clutch L / C ... Low clutch 2 & 4 / B ... Brake band L & R / B ... Low & reverse brake L / OWC ... One-way clutch

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (reference) F16H 59:72 F16H 59:72 63:12 63:12 F term (reference) 3G093 AA05 AA15 BA15 CA10 DA01 DA06 DB05 EA03 EA06 EB03 EB06 FB01 3J552 MA02 MA12 MA26 NA01 NB01 PA00 PA58 PA62 QA30C RC13 SA01 SA59 TA01 TB11 UA09 VA48W VC01W

Claims (5)

[Claims] An oil pressure control device for an automatic transmission that discharges air mixed in a hydraulic circuit by supplying oil pressure to a friction engagement element to be released at a current gear position during non-shifting. An oil pressure control device for an automatic transmission, wherein a discharge amount of an oil pump that supplies oil to the automatic transmission is increased at the time of oil pressure supply for air discharge. 2. A hydraulic control device for an automatic transmission, which discharges air mixed in a hydraulic circuit by supplying hydraulic pressure to a friction engagement element to be released at a current shift speed during non-shifting. The hydraulic pump for supplying air to the automatic transmission when the discharge amount of the oil pump that supplies oil to the automatic transmission is smaller than a minimum required amount, the discharge amount is increased. Hydraulic control device. 3. The system according to claim 1, wherein said oil pump is driven by an engine combined with said automatic transmission, and when said engine rotation speed is lower than a predetermined minimum rotation speed, said oil pump has a minimum discharge amount. 3. The discharge amount is increased by determining that the state is smaller than the amount and increasing the engine rotation speed.
A hydraulic control device for an automatic transmission according to claim 1. 4. The hydraulic control device for an automatic transmission according to claim 3, wherein the minimum rotation speed is set higher as the temperature of the hydraulic oil of the automatic transmission is lower. 5. The hydraulic control device for an automatic transmission according to claim 3, wherein said engine rotational speed is changed by controlling an intake air amount of said engine.