JPH04107360A - Shift control device for automatic transmission - Google Patents

Abstract

PURPOSE:To suppress variation of a speed as a drive force demanded by a driver is satisfied by providing a control means to prohibit shift up for a given time starting from under-mentioned shift down when the shift down is effected within a given time starting from a point of time when a transmission is shifted up. CONSTITUTION:A multistage shift gear mechanism 3 has a power transmission route switched by a shift switching means 5 operated by a fluid type actuator 4. An electronic control circuit composed by a microcomputer for controlling an electromagnetic means 6 for an automatic transmission is provided. An electronic control circuit 10 is provided with a shift up prohibiting means 14 and prohibits shift up until a second timer started by under-mentioned shift down shows zero when the shift down is effected before a first down timer shows zero. This constitution suppresses frequent variation of a speed as a drive force demanded by a driver is satisfied.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a shift control device for an automatic transmission having a plurality of gear stages.

(Prior art) In a vehicle equipped with a normal automatic transmission with multiple gears, shift control is performed by determining the optimal gear of the transmission from the throttle opening and vehicle speed or the turbine rotation speed of the torque converter. It is equipped with an electronic control circuit.

In such vehicles, when the vehicle speed fluctuates greatly depending on the road surface condition, the gear position is changed frequently.
This frequently causes shift shocks, which worsens the riding comfort of the vehicle. Therefore, for example, in the shift control device for an automatic transmission disclosed in Japanese Patent Application Laid-Open No. 1-164846, the transmission is shifted up. Downshifting is prohibited until a predetermined time has elapsed from the time when the transmission was shifted down, and upshifting is prohibited until a predetermined time has elapsed from the time when the transmission was downshifted.

However, as in the above publication, if downshifting is always prohibited until a predetermined period of time has elapsed from the time the transmission is upshifted, the driver must depress the accelerator pedal within the downshifting prohibited section. Even if acceleration by downshifting is requested, the transmission will not respond to the request, which has the drawback of giving the driver a sense of discomfort. On the other hand, if upshifting is always prohibited until a predetermined period of time has elapsed after the transmission is downshifted, then upshifting will not occur even though the driver no longer requests acceleration. This not only gives the driver a sense of discomfort, but also has the problem of worsening fuel efficiency.

(Objective of the Invention) Therefore, an object of the present invention is to provide a shift control device for an automatic transmission that can suppress frequent gear changes while satisfying the driving force required by the driver. .

(Structure of the Invention) In the shift control device for an automatic transmission according to the present invention, if a downshift is performed within a predetermined time from the time when the transmission is upshifted, a control means for prohibiting an upshift for a predetermined period thereafter. It is characterized by having the following.

Further, the control means is configured to cancel the prohibition of the upshift when the engine rotational speed exceeds a predetermined rotational speed within the time period during which the upshifting is prohibited.

(Effects of the Invention) According to the present invention, upshifting is prohibited within a predetermined time after the transmission is downshifted, only when upshifting is performed within a predetermined time before the downshifting point, If the time from upshift to downshift is equal to or greater than a predetermined value, there is no restriction on subsequent upshifts, so gears can be changed frequently while satisfying the driving force required by the driver. can be suppressed.

Furthermore, according to the present invention, even during the period in which upshifting is prohibited, if the engine speed exceeds a predetermined speed, the prohibition of upshifting is canceled. , it is possible to prevent deterioration of fuel efficiency and overspeeding of the engine due to prohibition of upshifts.

(Embodiments) Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a control system diagram of an automatic transmission according to an embodiment of the present invention, in which a torque converter 2 of the automatic transmission is connected to the output shaft of an engine 1, and a multi-speed gear mechanism is connected to the output shaft of the torque converter 2. 3 are connected to each other. The multi-speed gear mechanism 3 is configured such that a power transmission path is switched by a speed change switching means 5 operated by a fluid type actuator 4, and this fluid type actuator 4 is supplied with pressure fluid by an electromagnetic means 6 consisting of a solenoid. controlled.

10 is an electronic control circuit (ECU) consisting of a microcomputer for controlling the electromagnetic means 6 of the automatic transmission, and a signal output from the turbine rotation speed sensor 7 for detecting the turbine rotation speed NT of the torque converter 2; , a shift change determining means 11 that determines the timing of a shift based on a load detecting signal output from a throttle opening sensor 8 for detecting a throttle opening θ of the engine 1, and this shift change determining means The control means 12 drives and controls the electromagnetic means 6 based on a signal generated from the electromagnetic means 11 to change the speed. Further, the electronic control circuit 10 includes a timer 13, and the timer 13 includes a first timer TA, which is a down timer that starts from the time when an upshift is performed, with a predetermined time TA being set. If the set time is a predetermined time TB and a downshift is performed before the first timer TA becomes zero, the second timer TB is a downtimer that starts from the time of the downshift.

Furthermore, the electronic control circuit 10 includes upshift inhibiting means 14. If a downshift is performed before the first downtimer TA reaches zero, the upshift prohibiting means 14 prohibits upshifting until the second downtimer TB started by this downshift reaches zero. are doing.

Furthermore, this shift-up inhibiting means 14 receives a signal output from the engine rotation speed sensor 9 to prevent the engine rotation speed Ne from reaching a predetermined rotation speed Nov.
When the shift-up is exceeded, the prohibition of upshifting is canceled even during the upshifting prohibition period.

Next, the speed change control routine executed by the electronic control circuit (ECU) 10 will be explained with reference to the flowchart shown in FIG.

First, in step S1, the turbine rotation speed N output from the turbine rotation speed sensor 7 of the torque converter 2 is
T and the throttle opening θ output from the throttle opening sensor 8, and in the next step S2, the shift change determining means 11 determines whether the shift up condition is satisfied based on the current turbine rotation speed NT and the throttle opening θ. If the determination is YES, the control means 12 drives the electromagnetic means (solenoid) 6 to perform upshifting in step S3, and the timing means 1 in step S4.
3 starts the first down timer TA. In the next step S5, the shift change determining means 11 checks whether a downshift condition is satisfied based on the current turbine rotational speed NT and throttle opening θ, and if this determination is YES, the control means 11 performs a downshift. In the next step S7, it is checked whether the first down timer TA has become zero at the time when this downshift is executed, and if this determination is No, that is, from the upshift time 10 in FIG. When it is determined that the time T1 until the downshift time t1 is shorter than the predetermined time TA, the second down timer TB of the timer 13 is started in step S8.

Next, the process proceeds to step S9, where the shift change determination means 11
checks whether the upshift condition is satisfied based on the current turbine rotation speed NA and throttle opening θ, and if this determination is YES, the process advances to step S10 and the second down timer TB becomes zero. Check to see if it is. Then, when the determination in step SIO is No, that is, as shown in FIG. The inhibiting means 14 prohibits upshifting in step Sll, but when the determination in step SIO is YES, that is, as shown in FIG. When it is determined that the predetermined time TB has elapsed, the process advances to step S14 to execute an upshift.

On the other hand, during the period in which upshifting is prohibited in step S11, the output signal from the engine rotation speed sensor 9 is read in step S11, and it is determined in step S13 whether or not the engine rotation speed Ne exceeds the predetermined rotation speed Nov. Find out. While the determination in step S13 is No, the process returns to step S10 to continue prohibiting the upshift. However, if the determination in step S13 is YES, the process immediately advances to step S14, canceling the prohibition of the upshift and prohibiting the upshift. Execute.

As is clear from the above description, according to the present embodiment, the upshift inhibiting means 14 is provided, and if the downshift is performed before the predetermined time TA has elapsed after the downshift is performed, the shift Since the upshift prohibiting means 14 prohibits upshifting until the predetermined time TB has elapsed from the time of downshifting, it is possible to suppress frequent gear changes while satisfying the driving force required by the driver.

[Brief explanation of drawings]

FIG. 1 is a block diagram of an automatic transmission according to an embodiment of the present invention, FIG. 2 is a flowchart of a control routine executed by an electronic control circuit that controls the automatic transmission of FIG. 1, and FIGS. 3 and 4. 2 is a timing chart illustrating the operation of the automatic transmission shown in FIG. 1. FIG. 1... Engine 2... Torque converter 3... Multi-speed gear mechanism 6... Electromagnetic means 7...
Turbine rotation speed sensor 8...Throttle opening sensor 9...Engine rotation speed sensor 10...Electronic control circuit 11...Shift change determination means 12...Control means 13...Time measurement means 14...・Means for prohibiting upshifting

Claims (2)

[Claims] 1. In an automatic transmission having a plurality of gears, if a downshift is performed within a predetermined time from the time when the automatic transmission is shifted up, the automatic transmission is provided with a shift-up prohibition means for prohibiting a shift-up for a predetermined period thereafter. A shift control device for an automatic transmission characterized by: 2. 2. The shift control device according to claim 1, wherein the shift-up prohibition means cancels the shift-up prohibition when the engine rotation speed exceeds a predetermined rotation speed within the time period during which the shift-up is prohibited.