JPH1163198A - Shift controller for vehicular automatic transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively suppress racing and reduction (interlock) of rotation caused by sliding of a timing of a hydraulic pressure change, in a speed change for simultaneously carrying out respective hydraulic pressure control of a fastening side and an opening side. SOLUTION: Racing and interlock are detected at the time of speed change (by an interlock and racing detecting means A), hydraulic pressure and/or an engine output are corrected in a direction for suppressing generation of the racing and the interlock (by hydraulic pressure control means B, and engine output control means C). The change width of the engine output during changing speed is detected (by engine output change detecting means D), and the change width and a prescribed value are compared with each other (by engine output change width comparing means). When the change width exceeds the prescribed value, strong racing and interlock are generated, and thereby, a comparatively large value is applied as a correcting rate. On the other hand, when the change width is smaller than the prescribed value, weak racing and interlock are generated, and thereby, a comparatively small value is applied as the correcting rate (by a controlled variable switching means F).

Description

DETAILED DESCRIPTION OF THE INVENTION

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shift control device for an automatic transmission for a vehicle, and more particularly, to a shift control device that simultaneously controls engagement and disengagement of two friction engagement elements to perform a shift.

2. Description of the Related Art Conventionally, without using a one-way clutch,
2. Description of the Related Art There is known an automatic transmission for a vehicle that performs a shift by simultaneously controlling engagement and disengagement of two friction engagement elements. Further, in the automatic transmission having the above configuration, if the hydraulic pressure change on the engagement side is relatively slow with respect to the disengagement side, the engine speed is increased, and conversely, on the engagement side relative to the disengagement side. If the oil pressure changes too quickly, the torque will decrease and the engine speed will decrease (hereinafter,
(Referred to as “interlock”).
No. 28, etc.). As a technique for avoiding the occurrence of the interlock, Japanese Unexamined Patent Publication No. Hei 6-341527 discloses a correction that reduces the clutch pressure on the release side when the occurrence of the interlock is detected. Is added.

The interlock occurs due to various factors such as variation in hydraulic pressure and changes in engine output, and the degree of the interlock greatly varies depending on the factors. However, in the related art, when the occurrence of the interlock is detected, the same correction amount is always added, so that there is a problem that the interlock cannot be suppressed accurately. SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and provides an appropriate correction amount for the occurrence of interlock and blow-up, so that interlock and blow-up can be effectively suppressed. The purpose is to.

SUMMARY OF THE INVENTION Accordingly, the invention according to claim 1 is a shift control device for an automatic transmission for a vehicle, which performs a shift by simultaneously controlling engagement and disengagement of two friction engagement elements, It is configured as shown in FIG. In FIG. 1, the timing deviation detecting means detects occurrence of a relative timing deviation between a change in the engagement side hydraulic pressure and a change in the release side hydraulic pressure. The control amount correction means corrects the control amount at the time of shifting of at least one of the automatic transmission and the engine when the occurrence of the deviation is detected by the timing deviation detecting means.
The output change width detecting means detects a change width of the engine output during the shift, and the correction amount changing means corrects the control amount in the control amount correcting means in accordance with the change width detected by the output change width detecting means. Change the amount. According to this configuration, when the occurrence of the relative timing shift between the change in the engagement side hydraulic pressure and the change in the release side hydraulic pressure, in other words, the occurrence of the interlock or the blow-up due to the shift is detected, Alternatively, a correction is made to suppress the occurrence of a blow-up, but the correction amount is changed according to a variation width of the engine output during the shift. That is, the degree of interlock or blow-up varies depending on the change width of the engine output during gear shifting, and therefore, by changing the correction amount according to the change width, the degree of interlock or blow-up is consequently changed according to the degree of interlock or blow-up. The correction amount. According to a second aspect of the present invention, the timing shift detecting means detects the occurrence of the timing shift based on a change in engine rotation during a gear shift. According to such a configuration, if the hydraulic pressure change on the engagement side is relatively slow with respect to the release side, the rotation will be blown up. Since the decrease (interlock) occurs, the occurrence of a shift in the hydraulic pressure change timing is detected from the change in the engine rotation during gear shifting. According to the third aspect of the present invention, the control amount correction unit is configured to determine at least one of a reduction amount of the output torque of the engine during the shift and a supply hydraulic pressure to the engagement side and / or the release side friction engagement element during the shift. Was corrected. According to such a configuration, when an interlock occurs, for example, the occurrence of a shift shock due to the interlock is suppressed by reducing the hydraulic pressure on the release side or increasing the torque reduction request for reducing the engine output during shifting. When a blow-up occurs, the hydraulic pressure on the fastening side is increased to suppress the occurrence of a blow-up (a delay in the hydraulic pressure on the fastening side). Claim 4
In the invention described above, the correction amount changing unit increases the correction amount as the change width of the engine output during the shift is larger. According to this configuration, when the range of change in the engine output during gear shifting is large and the degree of interlock or blow-up is strong, the correction amount is made larger.

According to the first aspect of the present invention, it is possible to effectively reduce the occurrence of interlock or blow-up due to a shift in hydraulic control timing in a shift in which the engagement and release of the friction engagement elements are simultaneously controlled. Thus, there is an effect that the shifting performance can be improved. According to the second aspect of the invention, it is possible to easily detect occurrence of an interlock or a blow-up due to a shift in hydraulic control timing based on a change in engine rotation. According to the third aspect of the invention, by correcting the torque down amount at the time of shifting and correcting the supply of the hydraulic pressure to the engagement side and / or the release side frictional engagement element, a shift shock due to an interlock or blowing is generated. There is an effect that occurrence of rising can be prevented. According to the fourth aspect of the invention, there is an effect that the correction amount is increased as the degree of the interlock or the blow-up is higher, so that the occurrence of the interlock or the blow-up can be surely suppressed.

Embodiments of the present invention will be described below. FIG. 2 is a diagram showing a system configuration of an automatic transmission for a vehicle according to the present invention. The output torque of an engine 1 mounted on a vehicle (not shown) is transmitted to drive wheels via an automatic transmission 2. The automatic transmission 2 has a configuration in which a shift is performed by controlling the supply of operating hydraulic pressure to frictional engagement elements such as clutches and brakes by a solenoid valve unit 3.
Operate according to a control signal from a control unit 4 containing a microcomputer. The control unit 4 has a function of controlling fuel supply to the engine 1 together with the shift control. Specifically, as shown in FIG. 3, the automatic transmission 2 is configured to input the output torque of the engine via a torque converter T / C, and includes a front planetary gear set 83 and a rear planetary gear set 84.
And a reverse clutch R / C, a high clutch H / C, a band brake B /
B, low & reverse brake L & R / B, and forward clutch FWD / C. In FIG. 3, reference numeral 81 denotes an input shaft of the transmission, 82 denotes an output shaft of the transmission.
Indicates the engine rotation speed, Nt indicates the turbine rotation speed, and No indicates the output shaft rotation speed. In the above configuration, as shown in FIG. 4, the reverse clutch R / C and the high clutch H
/ C, band brake B / B, low & reverse brake L & R / B, engagement and disengagement of forward clutch FWD / C.
At the time of the 4th upshift, the forward clutch FWD
/ C and the engagement of the band brakes B / B are performed simultaneously. That is, the automatic transmission 2 in the present embodiment executes a shift (so-called clutch-to-clutch shift) in which the engagement and release of the two friction engagement elements are simultaneously performed by hydraulic control without using the one-way clutch. It has a configuration (see FIG. 5). In the clutch-to-clutch shift described above, if the change in the hydraulic pressure on the engagement side is relatively slow with respect to the release side, the engine speed will increase, and conversely, the change in the hydraulic pressure on the engagement side relative to the release side will occur. If it is too early, torque may be reduced or engine rotation may be reduced (hereinafter, referred to as an interlock). When an interlock occurs, a shift shock is applied, and when a blow-up occurs, an uncomfortable feeling is given to the driver. Therefore, in the present embodiment, as shown in FIG. 6, the occurrence of the interlock and blow-up is suppressed. In FIG. 6, an interlock / upward detecting unit A (timing shift detecting unit) monitors the engine rotation during a gear shift, and when an uprising of the engine rotation occurs, a change in the hydraulic pressure on the engagement side with respect to the release side. When it is determined that the engine speed is relatively delayed and, on the other hand, a decrease in the engine rotation occurs, it is determined that the change in the hydraulic pressure on the engagement side is relatively quick with respect to the release side, and the occurrence of the interlock is detected.
It should be noted that the occurrence of the interlock may be detected on the basis of the torque reduction at the time of gear shifting, and as disclosed in Japanese Patent Application Laid-Open No. 6-341527, from the start of the torque phase to the start of the inertia phase. The configuration may be such that the occurrence of an interlock is detected from the time. When the interlock / upward detection means A detects the occurrence of interlock and uptake (occurrence of a timing shift of the hydraulic pressure change), the hydraulic control means B (control amount correction means) sets the engagement side frictional engagement. The interlock and the blow-up are suppressed by correcting the hydraulic pressure for the element and / or the disengagement-side friction engagement element. For example, when an interlock occurs, the hydraulic pressure on the engagement side is relatively faster than that on the release side. Since the change in oil pressure on the engagement side is relatively slow, the oil pressure on the frictional engagement element on the engagement side is increased. That is, the hydraulic pressure is corrected as a control amount in a direction to suppress interlock and blow-up. In a configuration in which the output torque of the engine at the time of shifting is forcibly reduced (torque down), a method of suppressing occurrence of a shift shock due to an interlock may be configured to increase and correct the torque down amount. The engine output control means C (control amount correction means) increases and corrects the torque down amount (engine control amount) when the occurrence of the interlock is detected by the interlock / upward detection means A. As a method of lowering the output torque of the engine,
There are fuel cut for each cylinder and ignition timing retard correction, etc.
In the case of a configuration in which a fuel cut is performed, the number of cylinders in which a fuel cut is performed when an interlock occurs is increased, and in the case of a configuration in which ignition timing is retarded, the amount of retard correction is increased. I do. On the other hand, the engine output change detecting means D (output change width detecting means) detects the change width of the engine output during the gear shift. For simplicity, the throttle valve opening of the engine may be monitored, and the range of change from the throttle valve opening at the start of shifting may be detected as a value corresponding to the range of change in engine output during shifting. Instead of the valve opening, the output change width may be detected based on a parameter representing the engine load such as the intake air amount of the engine. The engine output change width comparison means E
The change width of the engine output detected by the engine output change detection means D is compared with a predetermined value, and the change width of the engine output during the shift is determined to be large or small. Control amount switching means F
(Correction amount changing means) is based on the comparison result by the engine output change width comparing means E, and the hydraulic control means B,
In the engine output control means C, a correction amount when correcting the hydraulic pressure or the engine output (control amount) to suppress interlock and blow-up is switched and set. When it is determined by the engine output change width comparing means E that the output change width during shifting is larger than a predetermined value, a relatively large value is set as the correction amount, and when the output change width is smaller than the predetermined value, , A relatively small value is set as the correction amount. When the variation range of the engine output is large, the degree of the interlock and the blow-up becomes stronger. Therefore, a large value is given as the correction amount so that the interlock and the blow-up can be surely suppressed.
On the other hand, when the variation range of the engine output is relatively small,
Since the degree of interlock and blow-up is weaker than when the variation width is large, a relatively small value is given as the correction amount in order to avoid excessive correction. As described above, if the correction amount for suppressing the interlock and the blow-up is switched in accordance with the degree of the interlock and the blow-up that varies depending on the variation width of the engine output, the strong interlock and the blow-up can be effectively achieved. And the occurrence of a shift shock due to the interlock or a sense of incongruity due to a blow-up can be prevented. Further, it is possible to prevent the control from overshooting due to an excessive correction amount when a relatively weak interlock or blow-up occurs. The control performed to suppress the occurrence of the interlock and the blow-up may be both the hydraulic control and the engine output control, or may be only one of them. A configuration may be employed in which control is performed so as to suppress only one of the lock and the blow-up. Further, in the above-described embodiment, the change width of the engine output during the shift is determined to be large or small by comparing with a predetermined value. However, the change width is determined in three or more stages, and A configuration may be adopted in which three or more different correction amounts are provided in response.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of the invention according to claim 1;

FIG. 2 is a system diagram showing an automatic transmission to which the present invention is applied.

FIG. 3 is a configuration diagram showing details of an automatic transmission.

FIG. 4 is a view showing a state of shifting by a combination of engagement states of friction engagement elements in the automatic transmission.

FIG. 5 is a time chart showing a state of hydraulic control during clutch-to-clutch shifting.

FIG. 6 is a control block diagram showing control for suppressing interlock and blow-up in the embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Engine 2 Automatic transmission 3 Solenoid valve unit 4 Control unit 83 Front planetary gear set 84 Rear planetary gear set R / C reverse clutch H / C high clutch B / B band brake L & R / B low & reverse brake FWD / C forward clutch

Continued on the front page (72) Inventor Hiroyuki Yuasa 1370 Onna, Atsugi-shi, Kanagawa Japan

Claims (4)

[Claims] A shift control device for an automatic transmission for a vehicle, which controls the engagement and disengagement of two friction engagement elements simultaneously to perform a shift, wherein a relative change between a change in engagement side hydraulic pressure and a change in release side hydraulic pressure. Timing deviation detecting means for detecting the occurrence of a timing deviation, and when the occurrence of the deviation is detected by the timing deviation detecting means, the control amount at the time of shifting of at least one of the automatic transmission and the engine is corrected. Control amount correction means; output change width detection means for detecting a change width of the engine output during shifting; correction of the control amount in the control amount correction means according to the change width detected by the output change width detection means. A shift control device for an automatic transmission for a vehicle, comprising: a correction amount changing unit that changes an amount. 2. A shift control device for an automatic transmission for a vehicle according to claim 1, wherein said timing shift detecting means detects occurrence of the timing shift based on a change in engine rotation during a shift. . 3. The control amount correcting means corrects at least one of a reduction amount of an output torque of an engine during a shift and an oil pressure supplied to a frictional engagement element on an engagement side and / or a release side during a shift. The shift control device for an automatic transmission for a vehicle according to claim 1 or 2, wherein 4. The vehicle according to claim 1, wherein the correction amount changing means increases the correction amount as the change width of the engine output during the shift is larger. Transmission control device for automatic transmission.