JPS6392860A - Kickdown controller for automatic transmission - Google Patents

Abstract

PURPOSE:To improve the traveling characteristic, by varying the kickdown vehicle speed of an automatic transmission under a specific operating condition of an engine. CONSTITUTION:An electronic circuit 210 for controlling an electromagnetic means 80 of a transmission is provided with a means 12 for varying the kickdown speed of the transmission for at least predetermined time after starting. Since engine stall can be prevented when a vehicle travels with full-open throttle immediately after starting, the traveling characteristic can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a kickdown control device for an automatic transmission used in an automobile.

(Prior Art) Conventionally, in a vehicle equipped with an electronically controlled fuel injection system (EGI), fuel is cut when the engine rotation speed exceeds a guaranteed engine speed in order to ensure engine reliability.

Furthermore, immediately after starting the engine, engine reliability cannot be ensured unless fuel is cut at a rotation speed lower than the guaranteed engine rotation speed, so a certain period of time (e.g. 60 seconds) must pass after the engine is started. Until then, the fuel injection system has been controlled to perform fuel cut at a rotation speed lower than the guaranteed rotation speed (for example, if the guaranteed rotation speed is 600 rpm, at 5500 rpo+).

On the other hand, in order to improve the driving characteristics and fuel efficiency of vehicles, electronically controlled vehicle automatic transmissions are used in conjunction with the above-mentioned electronically controlled fuel injection devices. For example, kick-down vehicle speeds (shift-up vehicle speeds and soft-down vehicle speeds when the throttle opening is almost fully opened) are set in a shift pattern as disclosed in Japanese Patent Publication No. 53-4195. The engine rotational speed at this kickdown vehicle speed is set to a slightly lower rotational speed than the above-mentioned guaranteed engine rotational speed (for example, if the guaranteed engine rotational speed is 600 rpm, the engine rotational speed at the kickdown vehicle speed is 5850 rpm). However, if the engine speed at this kickdown vehicle speed is set higher than the fuel cut speed immediately after the engine starts, if the throttle/torre is fully opened immediately after the engine starts, the fuel will be cut and the stall will occur, causing the driving characteristics to deteriorate. There was a problem that made things worse.

(Object of the Invention) In view of the above-mentioned circumstances, the present invention provides that the engine operates under predetermined operating conditions.
For example, the purpose is to improve running characteristics by eliminating stalls due to kickdown immediately after starting.

(Structure of the Invention) The present invention provides an automatic automatic transmission engine equipped with an engine in which fuel is cut under a predetermined operating condition, for example, when the engine rotation speed is equal to or higher than a set rotation speed until a certain period of time has elapsed after starting the engine. The vehicle with a transmission is characterized in that it is provided with means for changing the kickdown vehicle speed of the automatic transmission under a predetermined operating condition of the engine, for example, at least until the predetermined time period elapses after the engine is started.

(Effects of the Invention) According to the present invention, it is possible to prevent stalling and improve running characteristics under certain operating conditions of an engine in which a fuel cut is performed, for example, when the engine is running with the throttle fully open immediately after starting.

(Example) Examples of the present invention will be described in detail below with reference to the drawings.

FIG. 1 shows the configuration of an engine and an automatic transmission connected to the engine according to an embodiment of the present invention, and a control system diagram for these engines and automatic transmissions. , and this torque converter 10
A speed change gear mechanism 70 is connected to the output shaft of each. The speed change gear mechanism 70 has a power transmission path switched by a speed change switching means 75 operated by a fluid actuator 78.
The supply of pressure fluid is controlled by electromagnetic means 80. 2
00 is an electronic control circuit composed of a microcomputer that controls the fuel injection amount to the engine 1, and includes a start determination means 202 that determines that the engine has been started upon receiving a signal generated from the engine rotation speed sensor 201, and a timer 203 that measures the elapsed time and generates an output signal when a preset time (for example, 60 seconds) has elapsed after the engine is started; and an engine whose fuel is to be cut based on the output signal of the timer 203. It is equipped with a means 204 for changing the rotation speed, and a fuel rotation speed determination means 205 for determining that the engine rotation speed Ne obtained from the engine rotation speed sensor 201 has reached the fuel cut rotation speed obtained from the means 204, In response to the output of the determination means 205, the fuel injection valve control means 206 controls the fuel injection valve 2.
07 is controlled to cant the fuel.

On the other hand, 210 is an electronic control circuit composed of a microcomputer for controlling the electromagnetic means 80 of the automatic transmission, and based on the output from the start determination means 202 of the electronic control circuit 200 on the engine side, the electronic control circuit 210 determines the elapsed time after starting the engine. A timing means 21 that measures time and generates an output signal when a preset time has elapsed after starting the engine (for example, 60 seconds).
1, and means 212 for changing the kickdown vehicle speed based on the output signal of the timer 211.

Reference numeral 213 denotes shift change determination means, which receives information from the kickdown vehicle speed change means, a signal generated from a rotation speed sensor 214 that detects the rotation speed of the output shaft of the torque converter 10 (rotation speed of the turbine impeller), and a throttle signal. The control means 217 controls the electromagnetic means 80 based on the shift change signal generated from the shift change determination means 213 based on the engine load warning signal generated from the opening sensor 215 and the signal from the kickdown switch 216.
is configured to drive and control.

FIG. 2 shows the structure of the mechanical part of an electronically controlled automatic transmission with a lock-up mechanism and its hydraulic control circuit.

The automatic transmission includes a torque converter 10 connected to the output shaft 1a of the engine 1, a multi-speed gear mechanism 20 connected to the output shaft 14 of the torque converter 10, and the torque converter 10 and the multi-speed gear mechanism 20. and an overdrive planetary gear transmission tti50 installed between the two.

The torque converter 10 includes a pump impeller 11 (hereinafter abbreviated as "pump") coupled to an output shaft 1a of an engine 1, and a turbine runner 12 (hereinafter abbreviated as "turbine") disposed opposite to this pump 11. ) and
It has a stator 13 disposed between the pump 11 and the turbine 12, and the turbine 12 has a converter output shaft 14.
are combined. Converter output shaft 14 and pump 11
A lock-up clutch 15 is provided between the torque converter 10 and the lock-up clutch 15, which is constantly pushed in the engagement direction by the pressure of hydraulic fluid circulating within the torque converter 10, which is supplied to the clutch 15 from the outside. It is held in the released state by the release hydraulic pressure.

The multi-speed gear mechanism 20 has a front planetary gear mechanism 21 and a rear planetary gear mechanism 22. The front planetary gear mechanism 2
1 sun gear 23 and rear planetary gear mechanism 22 sun gear 2
4 through a connecting shaft 25. The input shaft 26 of the multi-speed gear mechanism 20 is configured to be connected to the connecting shaft 25 via a front clutch 27 and to the ring gear 29 of the front planetary gear mechanism 21 via a rear clutch 28. shaft 25 or both'
Sun gear 23.24 in ti star gear mechanism 21.22
A second brake 30 is provided between the transmission case and the transmission case. The pinion carrier 31 of the front planetary gear mechanism 21 and the ring gear 33 of the rear planetary gear mechanism 22 are connected to the output shaft 34, and a low gear is connected between the pinion carrier 35 of the rear planetary gear mechanism 22 and the transmission case. A reverse brake 36 and a one-way clutch 37 are provided. This multi-speed gear mechanism 20 is of a conventionally known type and has three forward speeds and one reverse speed, and the required speed is obtained by appropriately operating the clutch 27.2 and the brake 30.36. be.

On the other hand, in the overdrive planetary gear transmission mechanism 50 , a pinion carrier 52 that rotatably supports a planetary gear 51 is connected to the output shaft 14 of the torque converter 10 , and a sun gear 53 is connected to a ring gear 55 via a direct coupling clutch 54 . The structure is such that An overdrive brake 56 is provided between the sun gear 53 and the transmission case, and the sun gear 55 is connected to the input shaft 26 of the multi-speed gear mechanism 20. The overdrive planetary gear transmission mechanism 50 operates when the direct coupling clutch 54 is engaged and the brake 56 is released.
4.26 are connected in a direct connection, and when the brake 56 is engaged and the clutch 54 is released, the shaft 14.26 is connected in overdrive.

Next, to explain the fluid control circuit, the engine 1
The hydraulic oil discharged from the oil pump 100 into a pressure line 101 has its pressure adjusted by a pressure regulating valve 102 and is then guided to a manual select valve 103. It will be destroyed. This select valve 103 has shift positions of 1.2, D, N, R, and P, and when the shift positions are at the 1.2 and D positions, the pressure line 101 is connected to the boat 103 of the valve 103.
a, 103b, and 103C. Boat 103a
is connected to the actuator 104 of the rear clutch 28, and holds the release clutch 28 in an engaged state when the valve 103 is in the above-mentioned position.

The boat 103a is also connected to the vicinity of the left end of the 1-2 shift valve 110 in the figure, and pushes the spool 110a to the right in the figure. Further, the boat 103a is connected to the right end of the 1-2 shift valve 110 in the figure via the first line L1, and to the 2-3 shift valve 1 via the second line L2.
20 is connected to the upper end of the 3-4 shift valve 130 via the third line L3.

The first, second and third lines L1, L2 and L3 have first, second and third drain lines D1, D2, respectively.
and D3 are branched and connected, and these drain lines D1 to D3 are connected to drain lines D1 to D3, respectively.
The first, second, and third solenoid valves SLI to SLI open and close the
When L3 is connected and the solenoid valves 5LI-3L3 are energized, the first to third lines L1 to L3 are closed by closing each drain line DI-D3 while the pressure line 101 and boat 103a are in communication. The pressure inside L3 is increased.

Further, the boat 103b of the select valve 103 is connected to the second lock valve 105 via a line 140, and the pressure from this boat 103b is transferred to the spool 105a of the valve 105.
acts to push down the figure. And valve 1
When the spool 105a of 05 is in the lower position, the line 140 and the line 141 are in communication, and the hydraulic pressure is applied to the engagement side pressure chamber 1 of the actuator 108 of the second brake 30.
It is configured to be introduced on day 0 a and to hold the second brake 30 in the operating direction.

Furthermore, the boat 103c of the select valve 103 is connected to the second lock valve 105, and the pressure from the boat 103c acts to push the spool 105a of the valve 105 upward in the figure.

Further, the boat 103c is connected to the 2-3 shift valve 120 via the pressure line 106.

In this line 106, the solenoid valve SL2 of the second drain line D2 is energized to increase the pressure in the second line L2, and the pressure moves the spool 120a of the 2-3 shift valve 120 to the left in the figure. When line 10
It connects to 7. Line 107 is the second brake 30
When hydraulic pressure is introduced into this pressure chamber, the actuator 108 operates the brake 30 in the release direction against the pressure in the engagement pressure chamber 108a. .

Further, the pressure in the line 107 is also guided to the actuator 109 of the front clutch 27 to engage and operate the clutch 27.

The select valve 103 also has a bow 103d that communicates with the main line 101 in the 1 position, and this boat 103d is connected to the 1-2 shift valve 11L via the line 112.
) and is further connected to the actuator 114 of the low reverse brake 36 via a line 113.

The 1-2 shift valve 110 and the 2-3 shift valve 120 are
When the solenoid valves SLI and SL2 are energized by a predetermined signal, the respective spools 110a, 120a are moved to switch the lines, thereby operating a predetermined brake or clutch to operate the 1st-2nd and 2nd-3rd speeds, respectively.
It is configured such that a speed change operation is performed. Also,
115 is a cuffed pack valve that stabilizes the oil pressure from the pressure regulating valve 102, and 116 is a pressure regulating valve 1 according to the magnitude of the intake negative pressure.
A vacuum throttle valve 117 that changes the line pressure from 02 is a throttle valve 117 that assists this throttle valve 116.

In addition, the above fluid control circuit includes an overdrive 'i'
i star gear transmission side 50 clutch 54 and brake 5
6, an actuator 132 controlled by a 3-4 shift valve 130 is provided. The maintenance side pressure chamber 132a of the actuator 132 is connected to the pressure line 1.
01, and the pressure of the line 101 pushes the brake 56 in the engaging direction. Similarly to the 1-2, 2-3 shift valves 110 and 120, the spool 130a of the 3-4 shift valve +30 moves downward in the drawing when the solenoid valve SL3 is energized. Therefore, communication between pressure line 101 and line 122 is cut off, and line 122 is drained. As a result, the hydraulic pressure acting on the release side pressure chamber 132b of the actuator 132 of the brake 56 disappears, and the brake 56 is actuated in the engagement direction, and the actuator 134 of the clutch 54 acts to release the clutch 54.

Furthermore, the hydraulic control circuit includes a lock-up control valve 13.
3 is provided. This lock-up control valve 133 is connected to the boat 10 of the select valve 103 via a fourth line L4.
3a. A drain line D4, which is provided with a solenoid valve SL4, is branched and connected to the line L4, similarly to the drain lines DI to D3. and,
The lock-up control valve 133 is configured so that when the solenoid valve SL4 is energized to close the drain line D4 and the pressure in the line 4 increases, the spool 133a is
23 and line 124, and then line 1
24 is drained, thereby moving the rotary holder opening 15 in the connection direction.

As described above, the multi-speed gear mechanism 20 and the overdrive planetary gear mechanism 50 constitute the speed change gear mechanism 70 connected to the output shaft 14 of the torque converter 10, and the multi-speed gear mechanism 20 front clutch 27, rear clutch 28, second brake 30, low reverse brake 36, and direct clutch 54 of the overdrive planetary gear transmission mechanism 50.
The overdrive brake 5G constitutes a speed change switching means 75 which switches the power transmission path of the speed change gear mechanism 70 and performs a speed change operation.

In addition, the first to fourth solenoid valves SL1 to SL4 control each fluid actuator 104.
108, 109, 114, 132, and 134.

In the above configuration, the operational relationship between each gear, the lockup, and each solenoid, and the relationship between each gear and the clutch,
The operational relationship with the brake is shown in Tables 1 to 3 below.

Table 1 Table 2 On the other hand, the RAM of the microcomputer including the electronic control circuit 210 shown in FIG. A preset shift diagram, that is, change data consisting of an upshift shift line Lu and a downshift shift line Ld is stored. Also, although it is omitted in the diagram, is it a 7-book release system? The 11 line and the lockup activation control line are also stored. Furthermore, as shown in Fig. 3, the line indicating the kickdown rotation speed at the upper end of the shift amplifier speed line Lu is the normal kickdown mode A (solid line) where the turbine rotation speed is 585 rpm, and the normal kickdown mode A (solid line) where the turbine rotation speed is 5400 rpm. and low kickdown mode B (dashed line).

FIG. 5 shows a flowchart of a kickdown mode selection routine performed by the electronic control circuit 210. First, initialization settings are made in step S21. In this initialization setting, all flags and timers are reset, a start determination is made in step 322, and the timer is set in step S23. Then, in step 324, it is determined whether 60 seconds have elapsed or not. If 60 seconds have not elapsed, the process proceeds to step S25, where the low kickdown mode B, that is, the shift-up rotation speed during kickdown shown in FIG. The fuel cut rotation speed of the engine is set to 5850 rpm, which is lower than the 600 rpm. Further, if it is detected in step 324 that 60 seconds have elapsed, the process proceeds to step 326, and the normal kickdown mode A1, that is, the shift-up rotation speed during kickdown shown in FIG. Set to a lower 5400 rpm.

Note that instead of selecting the normal kickdown mode in step 326, a power mode and an economy mode with different shift amplifier transmission lines are set in advance, and after the elapsed time determination in step 324, it is determined whether the economy switch has been operated or not. The power mode and the economy mode may be selected by determining the power mode.

Furthermore, in the above embodiment, as is clear from FIG.
Engine starting is determined by the electronic control circuit 200 on the engine side, and this determination output is sent to the electronic control circuit 210 on the automatic transmission side.
However, instead of this, the electronic control circuit 210 on the automatic transmission side may calculate the timing based on the time when the turbine rotation speed reaches a predetermined rotation speed or higher. Instead of changing only the vehicle speed, other shift patterns may be used that include changing the kickdown vehicle speed.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the overall configuration of an embodiment of the present invention;
Fig. 2 is a diagram showing the structure and fluid control circuit of the automatic transmission, Fig. 3 is an explanatory diagram of shift-up shift control, Fig. 4 is an explanatory diagram of shift-down shift control, and Fig. 5 is a kick-down mode selection routine. This is a flowchart. 1-Engine 10...torque converter 14
- ) Lucon Hearter output shaft 20 - Multi-speed gear mechanism 21 - Front planetary gear mechanism 22 - Rear planetary gear mechanism 7〇 - Speed gear mechanism 75 - Speed change switching means 78 -
Fluid actuator 80--Electromagnetic control means 200.21O--Electronic control circuit 201--Engine speed sensor 207-Fuel injection valve

Claims (1)

[Claims] In a vehicle with an automatic transmission equipped with an engine that cuts fuel at an engine speed equal to or higher than a set engine speed when the engine is under a specified operating condition, the kickdown vehicle speed of the automatic transmission is set when the engine is under the specified operating condition. A kickdown control device for an automatic transmission, comprising a kickdown vehicle speed changing means for changing the kickdown vehicle speed.