JPH023754A - Device for controlling line pressure during changing speed for automatic speed change gear - Google Patents

Abstract

PURPOSE:To improve a speed change feeling by a method wherein shift control in which a line pressure characteristic pattern is caused to approach gradually by using one of line pressure characteristic patterns is effected during a time in which an automatic fluid oil temperature is increased to a set high oil temperature. CONSTITUTION:An A/T control unit 3 has a shift solenoid control part 31 which performs speed change by means of an engine load by a throttle opening sensor 6 and a signal from a car speed sensor 7, and by means of a speed change command and a signal from an ATF (automatic field) oil temperature sensor 8, a line pressure characteristic pattern is changed by a line pressure solenoid control means 32. In which case, the control means 32 has at least two different line pressure characteristics patterns, and shift control in which gradual approaching of an oil temperature to a high oil temperature pattern from a low oil temperature pattern is effected by means of at least one pattern is performed during a time in which an ATF oil temperature is increased to a set high oil temperature from a low oil temperature state. This constitution enables improvement of a speed change feeling in an ATF oil temperature region where the oil temperature approaches a set high oil temperature from a set low oil temperature.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to a line pressure control device for automatic transmission during gear shifting, and in particular to a line pressure control technology that corresponds to automatic fluid temperature (hereinafter referred to as ATF oil temperature). Regarding.

(Prior art) Conventionally, as a line pressure control device during gear shifting of an automatic transmission,
For example, the device described on page C-29 of "Nirasan Service Bulletin No. 578" (published by Nissan Motor Co., Ltd. on June 1, 1988) is known.

In order to improve the shift feeling (reducing shift shock), this conventional source describes line pressure control during gear shifts that sets the line pressure characteristics most suitable for that shift, and also describes viscosity changes due to ATF oil temperature. In order to prevent deterioration of the shift feeling (shift shock) due to the ATF oil temperature, line pressure control at low oil temperature is shown in which the line pressure characteristics are corrected according to the ATF oil temperature.

(Problem to be Solved by the Invention) However, in such conventional devices, two characteristic patterns are selectively controlled: line pressure characteristics at low oil temperature and line pressure characteristics at normal times. Because there is, ATF
Oil temperature settingIf the line pressure characteristics suddenly change after reaching a high oil temperature, and if the ATF oil temperature is in the low oil temperature range or stable in the range exceeding the set high oil temperature, shift shock may occur. However, in the oil temperature range where ATF oil temperature and low oil temperature approach the set high oil temperature, line pressure may be too low or too high during gear shifting, or even suddenly during gear shifting. There is a problem in that it is not possible to obtain a preferable shift feeling due to changes in line pressure.

Therefore, as a solution to the above problem, a line pressure characteristic pattern is set for each ATF oil temperature from the low oil temperature 1 state to the set high oil temperature, and It is conceivable to control the line pressure accordingly.

However, this method is disadvantageous in terms of cost because it is necessary to prepare many line pressure characteristic patterns, it takes time and effort to set the line pressure characteristic patterns, and a ROM with a high storage capacity is required.

The present invention focuses on the above-mentioned problems and aims to develop a low-cost shift line pressure control device that can improve the shift feeling in the ATF oil temperature range where the oil temperature approaches the set high oil temperature from a low oil temperature state. shall be.

We solved this problem by using the following means using shift control, and while being low cost, we tried to improve the shift feeling in the range of low oil temperature to close to the set high oil temperature <ATF oil temperature range. An object of the present invention is to provide a line pressure control device during gear shifting of an automatic transmission.

(Means for Solving the Problems) In order to solve the above-mentioned problems and achieve the above-mentioned objects, the shift line pressure control device of the present invention provides a shift-shifting system that performs shifting according to engine load, vehicle speed, and predetermined shift point characteristics. Line pressure control that inputs a control means, a shift command signal from the shift control means, and an oil temperature signal from the ATF oil temperature detection means, and performs control to change a line pressure characteristic pattern according to the ATF oil temperature during gear shifting. In the line pressure control device during gear shifting of an automatic transmission, the line pressure control means has at least two different line pressure characteristic patterns, and the line pressure control means changes from an ATF oil temperature state to a low oil temperature state to a set high oil temperature state. The means is characterized in that it is a means for performing shift control to gradually approach a low oil temperature pattern to a high oil temperature pattern using at least one of the line pressure characteristic patterns while the oil temperature changes up to .

(Function) While the ATF oil temperature changes from a low oil temperature state to a set high oil temperature, the line pressure control means selects at least one of at least two different preset line pressure characteristic patterns. Shift control is performed using two patterns to gradually bring the line pressure characteristic pattern closer from a low oil temperature pattern to a high oil temperature pattern.

Therefore, while reducing the number of preset line pressure characteristic patterns, line pressure control corresponding to the ATF oil temperature is performed sequentially by shift control from a low ATF oil temperature state to a set high oil temperature state. It turns out.

(Example) Embodiments of the present invention will be described below based on the drawings.

First, the configuration will be explained.

FIG. 1 is a diagram showing the overall configuration of the electronic control device of the automatic transmission according to the embodiment, in which 1 is the automatic transmission, 2 is the engine, and 3 is the control for controlling the speed change and line pressure of the automatic transmission 1 to the solenoid. This is an A/T control unit that operates based on operation commands.

The automatic transmission 1 includes a gear transmission mechanism operated by a torque converter and a hydraulic engagement element, and a hydraulic controller 4 that controls hydraulic pressure to the engagement element.The hydraulic controller 4 includes an A/T control unit. Shift solenoids A and B are incorporated as shift control actuators operated by commands from 3, and a line pressure solenoid 5 is incorporated as a line pressure control actuator.

The A/T control unit 3 includes a throttle opening sensor 6 (engine load detection means) that detects the throttle opening TH (engine load) and a vehicle speed sensor that detects the vehicle speed V, as means for providing input information. 7 (vehicle speed detection means), an ATF oil temperature sensor 8 (automatic fluid temperature detection means) that outputs an ATF oil temperature oil temperature film, and other sensors and switches 9 for obtaining other necessary information are connected.

Then, the A/T control unit 3 receives the shift solenoid A according to the throttle opening TH and vehicle speed V detection signals and predetermined shift point characteristics (Fig. 2).
, by the combination of ON and OFF signals to B (Figure 3)
, a shift solenoid control section 31 (shift control means) that performs automatic shift from 1st speed to 4th speed.

Further, the A/T control unit 3 has two different types of low oil temperature line pressure characteristic patterns LP and high oil temperature line pressure characteristic patterns HP (FIG. 6). The gear change command signal and the oil temperature signal from the ATF oil temperature sensor 8 are input, and the oil temperature changes from when the ATF oil temperature reaches the constant low oil temperature TLO until the set high oil temperature T1 is reached. It has a line pressure solenoid control unit 32 (line pressure control means) that performs shift control to gradually approach the high oil temperature line pressure characteristic pattern HP from the low oil temperature line pressure characteristic pattern LP using the oil temperature line pressure characteristic pattern LP. .

The line pressure control section 41 of the hydraulic controller 4, which is controlled by the line pressure solenoid 5, will be explained with reference to FIG.

The components include an oil pump 42, a pressure regulator valve 43, a pilot valve 44, and a pressure modifier valve 45. During normal times when no gear changes are being performed, the line pressure solenoid 5 is 0N-OFF controlled based on the throttle opening TH. The pressure modifier pressure P is regulated in the pressure modifier valve 45 using the throttle pressure PTH regulated by the signal pressure as a signal pressure and the pilot pressure PP regulated to a constant pressure by the operation of the pilot valve 44 as a hydraulic pressure source. By applying this pressure modifier pressure PM to the plug 43a of the engine regulator valve 43, the discharge pressure P0 from the oil pump 42 is changed as shown in the normal line pressure characteristic pattern NP shown by the dotted line in FIG. Then, the line pressure PL is adjusted according to the throttle opening TH.

The line pressure control during gear shifting is 0N-OFF ratio control (duty ratio control) of the line pressure solenoid 5 based on the shift command signal from the shift solenoid control unit 31 and the oil temperature signal from the ATF oil temperature sensor 8. This is done by

Next, the effect will be explained.

First, the flow of the line pressure control processing operation in the line pressure solenoid control section 32 of the A/T control unit 3 will be explained in the fifth section.
This will be explained with reference to the flowchart shown in the figure.

In step a, necessary input information such as a shift command signal and an ATF oil temperature oil film are input.

In step b, it is determined based on the shift command signal whether or not a shift command is being issued.

When the shift command is not issued, the process proceeds to step C, where line pressure control is performed based on the normal line pressure characteristic pattern NP, and when the shift command is issued, the process proceeds to step d and subsequent steps.

In step d, the ATF oil temperature oil temperature film constant low oil temperature TL0 and the set high oil temperature T1 are detected. A comparison was made with II.
Different line pressure controls are performed when T≦TLo, TLo<T<THI, and T≧T1.

When T≦TLo, the process proceeds from step d to step e, and line pressure control is performed based on the low oil temperature line pressure characteristic pattern LP.

When T L O < T < T H+, step d
Proceeds to step f, and in step f, the amount of change in oil temperature is calculated from the difference between the ATF oil temperature TN sampled this time and the ATF oil temperature oil temperature film -1 sampled a predetermined time ago. In step 9, the line pressure duty increase amount Δ is determined by the oil temperature change amount ΔT and a constant.
L is determined, and in step h, based on the line pressure duty increase amount ΔL and the low oil temperature line pressure characteristic pattern LP, as shown in FIG. 7, a proportional shift is performed to approach the high oil temperature line pressure characteristic pattern HP. Line pressure control is performed by the control.

When T≧THI, the process proceeds from step d to step 1, and line pressure control is performed based on the high oil temperature line pressure characteristic pattern HP.

Therefore, during a shift from 1st to 2nd speed, etc., the line pressure duty increase amount △ Based on L and the low oil temperature line pressure characteristic pattern LP, proportional shift control is used to gradually approach the high oil temperature line pressure characteristic pattern HP from the low oil temperature line pressure characteristic pattern LP. Similarly, line pressure control corresponding to the ATF oil temperature and oil temperature is performed.

As explained above, in the automatic transmission line pressure control device during gear shifting according to the embodiment, the ATF oil if T exceeds the set low oil temperature TLQ until it reaches the set high oil temperature T□1. Because this is a device that performs proportional shift control based on the low oil temperature line pressure characteristic pattern LP, it is a low cost device that has only two line pressure characteristic patterns, but it can change from a set low oil temperature to a set high oil temperature. It is possible to improve the shift feeling in the <ATF oil temperature region.

That is, it is possible to avoid a situation where the line pressure P is too low or too high during a shift, or where the line pressure PL suddenly changes during a shift, which worsens the shift feeling.

Although the embodiments have been described above based on the drawings, the specific configuration is not limited to these embodiments, and any changes or additions that do not depart from the gist of the present invention are included in the present invention. It will be done.

For example, in the embodiment, as a line pressure characteristic pattern, a low oil temperature line pressure characteristic pattern L, which is most advantageous in terms of equipment cost.
Although an example has been shown in which there are two patterns, P and the high oil temperature line pressure characteristic pattern HP, it is also possible to have three or four patterns.

In addition, in the example, this pattern is based on the low oil temperature line pressure characteristic pattern LP (high oil temperature line pressure characteristic pattern).
We have shown an example of proportional shift control that approaches IP, but on the contrary,
Proportional shift control may be used to bring this pattern closer to the high oil temperature line pressure characteristic pattern UP from the low oil temperature line positive characteristic pattern LP side based on the high oil temperature line pressure characteristic pattern HP. Temperature TLQ and set high oil temperature T
Until the intermediate oil temperature with HI is reached, shift control is performed based on the low oil temperature line pressure characteristic pattern LP, and once this intermediate oil temperature is exceeded, shift control is performed based on the high oil temperature line pressure characteristic pattern HP. You can also do it.

(Effects of the Invention) As explained above, in the line pressure control device during gear shifting of an automatic transmission of the present invention, the line pressure control means has at least two different line pressure characteristic patterns, and the automatic fluid Shift control in which the low oil temperature pattern gradually approaches the high oil temperature pattern using at least one of the line pressure characteristic patterns while the oil temperature changes from a low oil temperature state to a set high oil temperature. As a means of doing this, it is a low-cost device with few pre-set line pressure characteristic patterns, but it can move from a low set oil temperature to a high set oil temperature, improving the shift feeling in the <ATF oil temperature range. The effect of being able to achieve this goal is obtained.

[Brief explanation of the drawing]

Fig. 1 is an overall diagram showing a line pressure control device during shifting of an automatic transmission according to an embodiment of the present invention, Fig. 2 is a shift point characteristic diagram in shift control of the embodiment device, and Fig. 3 is a shift point characteristic diagram of the embodiment device. A diagram of the shift solenoid operation during control. Fig. 4 is a diagram showing the line pressure control device of the main part of the embodiment device. Fig. 5 is a flowchart of the line pressure control processing operation in the line pressure solenoid control section of the embodiment device. FIG. 6 is a line pressure characteristic diagram, and FIG. 7 is a line pressure duty characteristic diagram showing proportional shift control of line pressure when oil temperature rises. 1... Automatic transmission 2... Engine 3... A/T control unit 31... Shift solenoid control section (shift control means) 32... Line pressure solenoid control section (line pressure control means) 4 ...-Hydraulic controller 5...Line pressure solenoid 6...Throttle opening sensor (engine load detection means) 7...Vehicle speed sensor (vehicle speed detection means) 8...ATF oil temperature sensor (automatic... tank fluid temperature detection means) A, B...
・Shift solenoid

Claims (1)

[Scope of Claims] A shift control means for shifting according to the engine load, vehicle speed, and predetermined shift point characteristics; a shift command signal from the shift control means; and an oil temperature signal from the automatic fluid temperature detection means. and a line pressure control means for controlling a line pressure characteristic pattern to change according to the automatic fluid temperature during a shift. In a line pressure control device for an automatic transmission, the line pressure control means includes at least two types of line pressure control means. have different line pressure characteristic patterns, and while the automatic fluid temperature changes from a low oil temperature state to a set high oil temperature, at least one of the line pressure characteristic patterns is used to change the automatic fluid temperature from a low oil temperature pattern to a set high oil temperature. A shift line pressure control device for an automatic transmission, characterized in that it is a means for performing shift control to gradually approach a high oil temperature pattern.