JPS63203948A - Control device for automatic transmission - Google Patents

Abstract

PURPOSE:To prevent the occurrence of unevenness in gear shift characteristics and a change with time, by a method wherein the working pressure of a friction fastening element is corrected so that only in the case of standard gear shift conforming to a condition under which a reference value is set, an actual gear shift time is coincided with a preset reference value. CONSTITUTION:When gear shift is commanded, it is decided whether gear shift is standard. When the gear shift is not standard, a gear shift time is detected by means of a gear shift time detecting means, and the actual gear shift time is compared with a reference value, set by a reference value set means, by means of a comparing means. Based on the comparing result, a signal is outputted to an oil pressure command means by means of an oil pressure correction command means. When an actual gear shift time is coincided with a reference value, a working pressure is not corrected. This constitution prevents the occurrence of unevenness in gear shift performance of an automatic transmission, and enables prevention of production of a change of gear sift performance with time.

Description

[Detailed description of the invention] (b) Industrial application field The present invention relates to a control device for an automatic transmission.

(b) Conventional technology In conventional automatic transmissions, for example,
As shown in Publication No. 8, the supply of hydraulic pressure to the frictional engagement element is switched according to the throttle opening degree and the vehicle speed to control the gear shift, and the hydraulic pressure applied to the frictional engagement element is adjusted according to the throttle opening degree. It is composed of As a result, the oil pressure of the FJ lever engagement element during gear shifting is also adjusted in accordance with the throttle opening.

(C) Problems to be Solved by the Invention However, the conventional automatic transmission control devices as described above have problems such as variations in shift performance such as shift shock, and changes in shift performance over time. be. That is, the shift performance differs from one automatic transmission to another due to variations in hydraulic characteristics due to variations in valves, springs, etc. of each automatic transmission, and variations in frictional characteristics of frictional engagement elements.

In addition, even if the shifting performance is initially set to be appropriate, the shifting shock may gradually increase due to changes in characteristics due to wear of the J9 friction member, changes in frictional characteristics due to deterioration of the hydraulic oil, etc. .

In order to solve the above-mentioned problems, the applicant proposed in Japanese Patent Application No. 61-237038 that the friction engagement element is adjusted so that the actual shifting time from the start of shifting to the completion of shifting matches a preset reference value. It has been disclosed that the operating pressure of the invention is corrected. However, this method also has the following problems. That is, since correction is performed even when shifting is performed under operating conditions different from the standard operating conditions for which the reference value is set, the correction of the shifting time may not be appropriate.

For example, if the reference value of the shift time is set to an appropriate value for shifting with almost no change in the throttle opening (standard shifting), then it can be set to an appropriate value for shifting with almost no change in the throttle opening (standard shifting). In the case of shifting, the shifting time is also corrected so that it matches the reference value. In such a case, there is a possibility that the correction is not appropriate, and the shift performance may deteriorate due to the correction. The present invention aims to solve these problems.

(d) Means for Solving the Problems The present invention provides an operating pressure for the frictional engagement element so that the actual shifting time matches the preset reference value only in the case of standard shifting, which is the same as the condition for which the reference value was set. The above problem is solved by correcting.

That is, the automatic transmission control device according to the present invention is an automatic transmission in which a gear position is determined according to the operating state of a plurality of friction engagement elements, and includes an engine load sensor that detects engine load and a vehicle speed control device. a vehicle speed sensor that detects the friction; A shift actuator that switches the supply state of hydraulic pressure to the engagement element to correspond to the gear position commanded by the shift command means, and operates based on a shift command signal from the shift command means to command a hydraulic pressure value during shifting. A hydraulic command means for outputting a signal, and f! This is applied to a control device for an automatic transmission that has a hydraulic adjustment actuator that adjusts the hydraulic pressure supplied to the in-clamping element based on a signal from a hydraulic command means, and the gear shift commanded by the shift command means is controlled by the hydraulic pressure. A standard shift determination means determines whether or not the standard shift should be corrected, and only when the standard shift determination means determines that the shift is the standard shift, the shift command means outputs a shift command signal and then actually performs the shift command. Shift time detection means for detecting the shift time until the end of the shift; reference value setting means for presetting a reference value for the shift time; and a reference value set in the reference value setting means and the time of shift. a comparison means for comparing the shift time detected by the amount detection means; and a hydraulic correction for outputting a signal to the oil pressure command means to change the oil pressure in a direction in which the actual shift time approaches a reference value based on the comparison result of the comparison means. It is characterized by having a command means.

(E) When a working shift is commanded, it is determined whether it is a standard shift or not, and if it is not a standard shift, no correction is made to the shift time. In the case of standard shifting, the shifting time is detected by the shifting time amount detection means. This actual shift time and the reference value set in the reference value setting means are compared by the comparison means. Based on the comparison result of the comparison means, the oil pressure correction command means outputs a signal to the oil pressure command means to increase the operating pressure, for example, if the actual shift time is longer than the reference value. Conversely, if the actual gear shifting time is shorter than the reference value, the hydraulic command means (
Output No. 3. If the actual shift time matches the reference value, the operating pressure is not corrected. This eliminates variations in shift performance of the automatic transmission, and also prevents changes in shift performance over time.

(F) Embodiment FIG. 2 shows an embodiment of the present invention. The present invention is applicable to an automatic transmission with three forward speeds having two multi-disc clutches, one band brake, and one multi-disc brake as disclosed in, for example, Japanese Unexamined Patent Publication No. 60-1444. Since the number of frictional engagement elements is arbitrary, it can also be applied to automatic transmissions with four forward speeds, five forward speeds, etc. other than those mentioned above. Frictional engagement elements 10.12.14 and 16, which are multi-disc clutches, band brakes, multi-disc brakes, etc.
Operating pressure can be selectively supplied from the control valve 18. The supply of actuation pressure to the frictional engagement elements 10, 12, 14 and 16 is controlled by a variable speed actuator 20 located in the control valve 18. Also,
The hydraulic value of the operating pressure supplied to the frictional engagement elements 10.12.14 and 16 is regulated by a hydraulic adjustment actuator 22. The control valve 18 is the oil pump 2
The hydraulic pressure is adjusted and distributed as described above using the discharge pressure of No. 4 as a hydraulic pressure source. The speed change actuator 20 is composed of a plurality of solenoids and shift valves, and controls the hydraulic pressure supply state to the friction engagement elements 10, 12, 14, and 16 by switching the shift valves by turning on and off the solenoids. The hydraulic pressure adjustment actuator 22 is composed of a solenoid and a regulator valve whose duty ratio is controlled, and the pilot pressure is adjusted by controlling the opening/closing time ratio of the orifice with the solenoid, and this is applied to the regulator valve to achieve the desired result. Adjust the oil pressure. The control unit 26 operates the speed change actuator 20 and the hydraulic adjustment actuator 22.
controlled by electrical signals from A control unit 26 composed of a microcomputer receives signals from an engine load sensor 28 (for example, composed of a potentiometer that detects the throttle opening) and a vehicle speed sensor 30 that detects the speed of the vehicle.

The control unit 26 executes control as shown in FIG. First, an engine load signal is read from the engine load sensor 28 (step 100), then a vehicle speed signal is read from the vehicle speed sensor 30 (step 102), and then the read engine load signal and heavy speed signal are combined into a preset shift pattern. A comparison is made to determine an appropriate gear position for the current operating condition (step 104).

Next, it is determined whether the determined gear position matches the current actual gear position, that is, whether a gear change is necessary (step 106). If a shift is not required, the current operating state of the shift actuator 20 is maintained.
), the process returns to step 100. If a shift is required, the type of shift is identified (step 110). That is, it is determined whether the transmission is a 1-2 shift, a 2-3 shift, or the like. Next, the duty ratio P corresponding to the pressure value of the reference working pressure is calculated from the engine load signal (120), the calculated duty ratio P is multiplied by the correction coefficient k (122), and this is output (124). ). Further, a signal instructing the speed change actuator 20 to change speed is outputted to cause the speed change to be performed (126). Next, it is determined whether the commanded shift is a standard shift (see 1).
27). A standard shift is a shift under operating conditions similar to those for which the reference value of the shift time is set (for example, a shift under which the throttle opening degree is hardly changed). If the shift is not standard, it returns as is. Therefore,
For the next shift, the same value as the correction coefficient for the current shift will be used. In the case of standard shifting, the shifting time is measured (128). Note that measurement of the shift time starts after a signal instructing the shift actuator 20 to shift is output, and ends when the engine rotational speed completes a predetermined change. Next, the measured shift time is compared with a preset reference value (
132). If the shift time is equal to the reference value (strictly speaking, if the shift time is between the upper and lower limits of the reference value), the correction coefficient is not corrected (134). If the shift time is longer than the reference value, a small constant α is added to the previous correction coefficient k.
The value obtained by adding the above is used as a new correction coefficient (136).

Conversely, if the shift time is shorter than the reference value, a new correction coefficient is determined by subtracting α from the previous correction coefficient k (step 138). Then return. Therefore, in the next shift, the duty ratio will be determined based on the new correction coefficient k.

As a result, the -j control adjusts the operating pressure during the shift time so that the actual shift time coincides with the reference value. Therefore, all automatic transmissions having the same reference value are shifted in the same shift time, eliminating variations in shift performance. Further, even if the characteristics of the ia fastening element, hydraulic oil, etc. change over time, the shift time can be kept constant. Furthermore, since the shift time remains constant even if engine characteristics or vehicle weight change, there is no need for adjustment work for each vehicle and engine, which was required in the past. Since the correction coefficient is only corrected in the case of standard shifting, the correction is made only under the same driving conditions as the one for which the standard value was set, and the shifting performance can be corrected with precision. be able to.

Note that the reference value for the shift time can be set to a constant value regardless of driving conditions, the type of shift, etc., or can be changed depending on the engine load, vehicle speed, and type of shift.

(g) As described in detail, according to the present invention, the operating pressure is adjusted so that the actual shifting time matches a preset reference value only in the case of standard shifting, so It is possible to reliably prevent variations in performance and changes over time.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the relationship between the constituent elements of the invention, FIG. 2 is a diagram showing an embodiment of the invention, and FIG. 3 is a diagram showing a control flow. 10.12, 14.16... Frictional fastening element, 20...
・Speed change actuator, 22... Hydraulic pressure adjustment actuator, 24... Oil pump, 26... Control unit, 28... Engine load sensor, 30...
··Vehicle Speed Sensor.

Claims (1)

[Scope of Claims] An automatic transmission in which a gear stage is determined according to the operating state of a plurality of frictional engagement elements, comprising: an engine load sensor that detects engine load; a vehicle speed sensor that detects vehicle speed; A shift command means that compares signals input from the engine load sensor and vehicle speed sensor with a preset shift pattern and outputs a shift command signal under operating conditions that require a shift, and supplies hydraulic pressure to the friction engagement element. A shift actuator that switches its state to correspond to the gear position commanded by the shift command means, and a hydraulic command means that operates based on a shift command signal from the shift command means and outputs a signal that commands a hydraulic pressure value during shifting. and a hydraulic adjustment actuator that adjusts the hydraulic pressure supplied to the friction engagement element based on a signal from the hydraulic pressure command means, in which the gear shift commanded by the shift command means should perform hydraulic correction. A standard shift determination means determines whether or not the shift is a standard shift, and only when the standard shift determination means determines that the shift is a standard shift, the shift command means outputs a shift command signal, and then the shift actually ends. Shift time detection means for detecting the shift time up to 100%, reference value setting means for which a reference value of the shift time is set in advance, and the reference value set in the reference value setting means and the shift time detected by the shift time detection means. and a hydraulic correction command means for outputting a signal to the hydraulic pressure command means to change the hydraulic pressure in a direction in which the actual shift time approaches a reference value based on the comparison result of the comparison means. An automatic transmission control device featuring: