JPH0712214A - Control device of automatic transmission for vehicle - Google Patents

Abstract

PURPOSE:To prevent deterioration of oil accompanying temperature rise, and additionally maintain the operating performance in its favorable condition. CONSTITUTION:This is the control device of an automatic transmission A in which manual speed change mode can be set, and it is provided with an oil temperature judging means 3 detecting or estimating oil temperature, a starting shift step detecting means 4 detecting the shift step at starting by manual operation, and a low speed step indicating means 5 outputting so as to set the shift step at starting by manual operation in case of oil temperature over a decided value into a lower speed step than the shift step detected by the starting shift step detecting means 4. Further it is provided with a low output indicating means 6 changing the output of an engine E to low output when the low speed step indicating means 5 outputs so as to set the shift step into a lower speed step than the shift step detected by the starting shift step detecting means 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for an automatic transmission for a vehicle, which is capable of operating a shift operating means to shift to a selected gear.

[0002]

2. Description of the Related Art Generally, an automatic transmission for a vehicle is designed to start, run and stop by operating an accelerator pedal and a brake pedal.
It is connected to the engine via a fluid coupling such as a torque converter. This type of fluid coupling causes a spiral flow of a fluid such as oil to be generated by the rotation of the pump impeller, which is given to the turbine runner, and the turbine runner is rotated by the kinetic energy of the fluid. The torque is transmitted to the output side.

The rotational speeds of the pump impeller and the turbine runner must be different, but if the rotational speed difference is large, that is, if the speed ratio is small, the shearing action on the fluid becomes remarkable and the fluid It causes a rise in temperature. The oil used in fluid couplings such as torque converters becomes less durable as the temperature rises and the temperature rises more frequently, and the gear ratio set in the automatic transmission changes from the throttle opening. The velocity ratio of the fluid coupling becomes small when the velocity ratio is relatively small. Therefore, for example, in the invention disclosed in Japanese Patent Laid-Open No. 61-189354, a shift pattern is selected based on the rotational speed difference or the rotational speed ratio of the input / output shafts so that a shift speed for low speed is easily achieved, and the shift is performed. It is configured to achieve the shift speed based on the pattern.

[0004]

By the way, an electronically controlled automatic transmission, which has been widely used recently, is configured to achieve a shift speed according to a running state by controlling a solenoid valve based on an electric signal. Therefore, the degree of freedom in selecting the shift speed is high. Utilizing these characteristics, an automatic gear shift is configured so that a shift speed signal is output based on a manual operation of a shift operating device such as a shift lever or a shift switch, and thereby an appropriate shift speed can be achieved. Machines have also been developed. In an automatic transmission equipped with such a so-called manual shift mode, the selection of the shift speed is performed based on the driver's free will and does not depend on the shift pattern. is there. In such a case, the difference between the rotational speed of the pump impeller and the rotational speed of the turbine runner in the torque converter becomes large, that is, the speed ratio becomes small, and as a result, the oil temperature rises significantly. As described above, since the manual shift mode does not follow the shift pattern, it is not possible to perform control for lowering the oil temperature depending on the above-mentioned conventional device, and there is a possibility that fluid deterioration of the automatic transmission may be accelerated.

The present invention has been made in view of the above circumstances, and prevents an increase in temperature of a fluid such as oil and a deterioration in durability thereof in an automatic transmission in which a gear can be selected based on a manual operation. It is an object of the present invention to provide a control device that can do the above.

[0006]

The present invention is characterized in that it has the structure shown in FIG. 1 in order to achieve the above object. That is, the present invention relates to a control device for an automatic transmission A for a vehicle, which is connected to an engine E via a fluid coupling 1 and is capable of executing a shift commanded by manually operating a shift operating means 2. The oil temperature determination means 3 for detecting or estimating the oil temperature, the starting shift speed detecting means 4 for detecting the shift speed when the vehicle is manually started, and the oil temperature detected or estimated by the oil temperature determination means 3 are predetermined. When the temperature is equal to or higher than the temperature, a low-speed gear instruction means 5 for outputting to set the gear speed at the time of starting by manual operation to a lower gear speed than the gear speed detected by the starting gear speed detecting means 4, and the starting gear speed detecting means. And a low output instruction means 6 for changing the output of the engine E to a low output when the low speed instruction means 5 outputs so as to set a lower speed than the shift speed detected in 4. Do It is.

[0007]

The automatic transmission A of the present invention is connected to the engine E via the fluid coupling 1, and the oil temperature thereof is detected or estimated by the oil temperature detecting means 3. Further, the shift speed can be selected by the shift operating means 2 in addition to being selected based on the traveling state, and the shift speed selected by the manual operation at the time of starting is detected by the start shift speed detecting means 4. When the detected or estimated oil temperature is equal to or higher than a predetermined value, the low-speed gear is output by the low-speed gear indicating means 5 from the gear position at the time of starting selected by manual operation. The low output instructing means 6 outputs a signal so that the output of is low.
Therefore, if the oil temperature is high or the oil temperature is high, the shift speed at the start is set to the low shift speed regardless of the shift speed selected by the shift operating means 2, so that the increase in the oil temperature is suppressed. Further, the deterioration of its durability is prevented. Also, in order to reduce the engine output, despite the downsit,
No more driving force than necessary.

[0008]

Embodiments of the present invention will now be described with reference to the drawings. FIG. 2 is a block diagram showing a basic configuration of an embodiment of the present invention, in which an automatic transmission A is connected to an engine E via a torque converter described later. The engine E is configured to change the output characteristic into at least two stages, high and low, by changing the fuel injection amount with respect to the accelerator opening. Further, the automatic transmission A is configured to be capable of selecting an automatic shift mode in which a shift speed is set according to a running state and a manual shift mode in which a shift speed is set based on a manual operation. That is, the automatic transmission A
Are solenoid valves S1 and S2 for shifting in the hydraulic control device 20, a solenoid valve S3 for bringing the engine brake into an effective state, a line pressure solenoid valve SLT, a lockup clutch solenoid valve SLU, and an accumulator back. The solenoid valve for pressure SLN is connected to the electronic control unit (E
CU) 21 and a shift device 22 operated by a shift lever operates a manual valve to set a predetermined range, and also operates a gear switch to set a predetermined gear. There is. The electronic control unit 21 for the automatic transmission and the electronic control unit (E-ECU) 10 for the engine are connected to each other so that data communication is possible.

The shift device 22 includes a shift lever 23.
It has a function of selecting a driving range in the automatic shift mode while selecting a shift stage in the manual shift mode. An example of this is shown in FIGS. 3 and 4,
The parking (P), reverse (R), neutral (N), and drive (D) range positions are linearly arranged in the front-rear direction of the vehicle, and four shifts are centered around the drive range position. Step switch SW1, SW2,
SW3 and SW4 are arranged in an "H" shape. The position where these switches SW1 to SW4 are provided is "H" that intersects the "I" -shaped groove 24 connecting the range positions.
They are connected by a groove 25 having a V shape. The shift lever 23 rotates about a first shaft (tentatively referred to as a vertical axis) 26 and a second axis (provisionally referred to as a horizontal axis) 27 that extends in a direction parallel to the I-shaped groove 24. It is movably supported and extends upward through the upper plate 28 in which the grooves 24 and 25 are formed.

Two detent solenoids 30 for projecting a pin 29 in the left-right direction orthogonal to the I-shaped groove 24 at a position above the center of rotation of the shift lever 23,
31 are attached side by side vertically. The upper detent solenoid 30 is a detent solenoid for the first speed and the third speed, and is engaged with the pin 29 thereof so that the shift lever 23 enters the first and third speed positions in the H-shaped groove 25. As shown in FIG. 4, detent plates 32 and 33 for preventing the above-mentioned operation are provided at the entrances of these shift speed positions. Similarly, the detent plates 34 and 35 that engage with the pin 29 of the other detent solenoid 33 disposed on the lower side are provided at the entrances of the second speed position and the fourth speed position.

Then, the shift lever 23 is moved from the drive range position to the H-shaped groove 25 and one of the switches SW1 to SW4 is turned ON to switch to the manual shift mode, and the switches SW1 to SW4 are switched.
The gear stage instructed by the signal from is set in a state where the engine brake is effective. Further, regarding a gear position where a predetermined prohibition condition such as a possibility of engine overrun is satisfied, the detent solenoids 30 and 31 corresponding to the gear position are turned on and the pin 29 thereof is projected. The pin 29 engages with the detent plates 32 to 35 so that the shift lever 23 does not move to the gear position. The switches SW1 to SW4 are connected to the electronic control unit 21 so as to send signals to the electronic control unit 21, and the detent solenoids 30 and 31 are ON / OFF controlled by output signals from the electronic control unit 21. ing.

The electronic control unit 21 will be briefly described below. The electronic control unit 21 is a central processing unit (CP).
U) and storage elements such as ROM and RAM. The electronic control unit 21 includes an input interface circuit 36 as shown in the block diagram of FIG.
Via the switches, the signals from the respective speed stage switches SW1 to SW4,
D / G / T signal, signal from auto drive computer, signal from neutral start switch, signal from oil temperature sensor, signal from water temperature sensor, signal from throttle position sensor, engine speed N
e signal, signal from speed sensors NO.1 and NO.2, signal from transmission (TM) input speed sensor, signal from kick down switch, signal from transmission control switch, signal from stop lamp switch, pattern The signals from the select switches are input respectively. Further, a signal is output to the fuel injection control computer (EFI computer) via the output interface circuit 37, and via another output interface circuit 37.
Signals are output to the solenoid valves S1 and S2 for speed change, the solenoid valve S3 for engine brake, the solenoid valve SLT for line pressure control, the solenoid valve SLU for lockup clutch control, and the solenoid valve SLN for accumulator back pressure control. Further, a signal is output to the detent solenoids 30 and 31, and a diagnosis signal is also output. The electronic control unit 21 is connected to the battery 39 via the constant voltage power supply 38.

The automatic transmission A controlled by the electronic control unit 21 is, for example, the automatic transmission described in Japanese Patent Laid-Open No. 4-185967, and an automatic transmission mode and a manual transmission mode are targeted for the automatic transmission A. An example of the hydraulic control device for executing the shift is the hydraulic circuit described in the publication. The gear train and hydraulic circuit in the automatic transmission will be briefly described below.

That is, the automatic transmission A shown in FIG. 6 has a torque converter Tc having a lockup clutch Lc.
A second speed change section G2 having a set of planetary gear mechanisms, and a first speed change section G1 for setting a plurality of forward speeds and reverse speeds by the two sets of planetary gear mechanisms.

The second speed change section G2 is for performing two-stage switching between high and low, and the carrier 40 of the planetary gear mechanism is connected to the turbine runner Tr of the torque converter Tc, and this carrier 40 is also connected. Between the sun gear 41 and the sun gear 41, a clutch C0 and a one-way clutch Fo are provided in parallel with each other.
A brake B0 is provided between the housing and the housing Hu.

The sun gears 42, 43 in each planetary gear mechanism of the first speed change unit G1 are provided on a common sun gear shaft 44, and in the planetary gear mechanism on the left side (front side) in the figure of the first speed change unit G1. Ring gear 45 and second
A first clutch C1 is provided between the gear unit G2 and the ring gear 46, and a second clutch C2 is provided between the sun gear shaft 44 and the ring gear 46 of the second gear unit 38. The carrier 47 of the planetary gear mechanism on the left side of the drawing and the ring gear 48 of the planetary gear mechanism on the right side (rear side) in the first transmission portion G1 are integrally connected, and
The output shaft 49 is attached to the carrier 47 and the ring gear 48.
Are connected.

The first brake B1 which is a band brake is provided on the outer peripheral side of the clutch drum of the second clutch C2 so as to stop the rotation of the sun gear shaft 44, more specifically, the sun gear shaft 44 and the housing. A first one-way clutch F1 and a second brake B2 are arranged in series with Hu, and a second one-way clutch F2 with a carrier Hu and a housing Hu in the planetary gear mechanism on the rear side. The third brake B3 is arranged in parallel.

The automatic transmission A having the above gear train can set the first speed to the fourth speed at the forward speed, and among these, the first speed and the second speed are engine brakes in the automatic speed change mode. Does not work and it is necessary to apply the engine brake in the manual shift mode. Therefore, the hydraulic control device 20 includes the hydraulic circuit shown in FIG.

The manual valve 60 is a shift lever 2
It is switched to four positions of P, R, N and D corresponding to the range position which can be selected by 3, and the line pressure PL is supplied and discharged from a predetermined port according to each range position. .

In the 1-2 shift valve 70, the signal pressure from the second solenoid valve S2 is selectively supplied to the control port 71, and the hydraulic pressure of the second clutch C2 is selectively supplied to the hold port 72. As a result, in the first speed, the state shown in the right half of the figure is obtained, and in the second to fourth speeds, the state shown in the left half is obtained, and the first to third brakes B are provided.
Supply and discharge hydraulic pressure to 1 and B3.

In the 2-3 shift valve 80, the signal pressure of the first solenoid valve S1 is selectively supplied to the control port 81, so that in the first speed and the second speed, the state shown in the right half of the figure is obtained. In the third speed and the fourth speed, the state shown in the left half of the figure is established, and the hydraulic pressure is selectively supplied to and discharged from the second clutch C2.

In the 3-4 shift valve 90, the signal pressure from the second solenoid valve S2 is selectively supplied to the control port 91, and the line pressure PL is 2-3 shift valve 80.
As a result of being selectively supplied to the hold port 92 via the gears, the state shown in the right half of the figure is obtained in the first to third speeds, and the state shown in the left half of the figure is obtained in the fourth speed. As a result, the clutch C0 and the brake B0 of the second speed change section G2 are
And selectively supply hydraulic pressure to.

The third solenoid valve S3 controls the coast brake cutoff valve 100, and when the first speed or the second speed is selected in the manual shift mode, the third solenoid valve S3 is turned on, and as a result, The line pressure PL is supplied from the coast brake cutoff valve 100 to the first brake B1 or the third brake B3 via the 2-3 shift valve 80 and the 1-2 shift valve 70 so that the engine brake is effective at these shift speeds. Has become.

Here, the ON / OFF states of the first to third solenoid valves S1, S2, S3 for setting the respective shift speeds in the automatic shift mode and the manual shift mode, and the engagement / disengagement of each friction engagement device. If you show the state of release,
This is as shown in FIG. 8 is an operation table,
The mark indicates ON for the solenoid valve, engagement for the friction engagement device, and the cross indicates OFF for the solenoid valve, release for the friction engagement device.

When the vehicle is traveling forward in the automatic transmission mode in the above-described automatic transmission, the shift lever 23 is set to the D range position. In this state, the gear position is determined based on the traveling state represented by the throttle opening θ and the vehicle speed V, and the electronic control unit 21 determines the solenoid valve S.
A signal is output to 1, S2 and S3 to set a predetermined gear. Also, when shifting in the manual shift mode,
The shift lever 23 is moved to any gear position in the H-shaped groove 25. As a result, the switches SW1 to SW4 at the gear position are turned on to output a signal, so that the friction engagement devices are engaged or released so as to set the gear position corresponding to the gear position. To be made. When setting the first speed or the second speed in this manual shift mode, the third solenoid valve S3 must be turned on.
It is operated and the engine brake is activated.

In the above-mentioned automatic transmission, the shift stage can be freely selected by the shift lever 23. However, the selected shift stage at the time of starting or when the vehicle speed is lower than a predetermined speed is the state of the automatic transmission A, specifically, If it is not suitable for the state of the torque converter Tc, a gear stage different from the selected gear stage is set. FIG. 9 is a flowchart showing a control routine therefor.

In FIG. 9, after the input signal is processed (step 1), the manual shift mode (direct mode:
It is determined whether or not the DM mode) is selected (step 2). If the DM mode is not selected, the process returns, and if the DM mode is selected,
It is determined whether each sensor is normal (step 3). If there is an abnormality, the routine returns, and if normal, the routine proceeds to step 4, where the vehicle speed V is a predetermined reference speed α (for example, 20 km).
/ h) Judgment is over. This judgment is made only at the start. If the vehicle speed V is lower than the reference speed α, it is determined whether the oil temperature To is higher than a predetermined reference temperature β ° C (step 5).

When the oil temperature To is higher than the reference temperature β ° C., the routine proceeds to step 6, where the current shift speed selected in the manual shift mode, that is, the output signal from the switches SW1 to SW4 is instructed. The gear that is one speed lower than the existing gear is output as the gear when starting. At the same time, the engine output characteristic with respect to the accelerator opening is changed (step 7). Specifically, it has a low output characteristic. Figure 1
The map is shown in 0, and the curve marked with in FIG. 10 is the output characteristic at the normal time, and the curve marked with is forcibly the starting shift speed and the shift speed on the lower speed side. Is the output characteristic when. By performing the engine output reduction control as described above, the increase in the driving force that accompanies the forcibly setting the shift speed to the low speed is corrected by the decrease in the engine output. Sexual deterioration is prevented.

If the oil temperature To is equal to or lower than the reference temperature β ° C., the process proceeds to step 8 to judge the speed ratio. Here, the speed ratio is the ratio of the turbine speed Nt in the tor converter Tc to the engine speed Ne which is the input speed (N
t / Ne), and the smaller the value, the more pronounced the shearing action that acts on the oil inside the torque converter Tc, resulting in an increase in the oil temperature. In step 8, it is determined whether or not this speed ratio is equal to or less than a predetermined value γ (for example, “0.5”) and whether or not the duration of the state is a predetermined time δ (for example, 30 seconds) or more. If the determination result is "yes", the process proceeds to step 6 and the oil temperature To is the reference temperature β.
Similarly to the case where the temperature is higher than ℃, the shift speed at the time of starting is changed to the shift speed on the lower side by one step, and the output characteristic of the engine E is changed to the low characteristic (step 7).

The gears set in step 6 are shown in a table as shown in FIG. 11. When the gears of the second speed and higher are selected by manual operation, the gears are respectively selected. The shift speed lower by one speed is set as the shift speed at the start.

On the other hand, when the result of the determination in step 8 is "NO", the routine proceeds to step 9, where control is performed in the normal DM mode, that is, when the vehicle is started, the vehicle is started at the gear selected by manual operation. .

Therefore, according to the above control, when the oil temperature is high, or when the oil temperature is likely to be even higher, the shift speed at the start is changed to the shift speed on the low speed side. The speed ratio in the converter Tc becomes relatively large, and as a result, the temperature rise of the oil is suppressed and deterioration of the oil is prevented.

In the above embodiment, the automatic transmission in which the shift lever is used to select the shift speed in the manual shift mode is shown as an example, but the present invention is not limited to the above embodiment. Thus, the present invention can be applied to a control device for an automatic transmission that selects a shift speed by operating a switch. The present invention can also be applied to a control device for an automatic transmission including a gear train other than the gear train shown in FIG. 6 or a hydraulic circuit other than the hydraulic circuit shown in FIG.

[0034]

As is apparent from the above description, according to the control device of the present invention, when the oil temperature is high, or when the oil temperature is likely to be high, the start speed selected in the manual shift mode is selected. When changing the current gear to a lower gear and also changing the engine output characteristics to low characteristics, it is possible to reduce the shearing action on the oil in the fluid coupling and suppress its temperature rise, which in turn deteriorates it. Can be prevented. Further, since the output characteristic of the engine is changed to the low characteristic in accordance with the shift speed being changed to the low speed side, the driving force is not excessive, and therefore the operability (drivability) of the vehicle is improved. be able to.

[Brief description of drawings]

FIG. 1 is a block diagram for explaining a basic configuration of the present invention.

FIG. 2 is a block diagram schematically showing an embodiment of the present invention.

FIG. 3 is a diagram showing a shape and a shift position of a guide groove of a shift lever of a shift device.

FIG. 4 is a diagram schematically showing a detent mechanism in the shift device shown in FIG.

FIG. 5 is a block diagram schematically showing a control system of the electronic control unit.

FIG. 6 is a skeleton diagram showing a gear train.

FIG. 7 is a hydraulic circuit diagram showing a main part of a hydraulic circuit.

FIG. 8 is a diagram showing an engagement operation table of the friction engagement device for setting each shift speed.

FIG. 9 is a flow chart showing a control routine for changing a shift speed and changing an output characteristic of an engine when starting.

FIG. 10 is a diagram showing a relationship between accelerator opening and engine output.

FIG. 11 is a chart showing a shift speed selected by a manual operation and a changed shift speed.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Fluid coupling 2 Shift operation means 3 Oil temperature determination means 4 Start gear stage detection means 5 Low speed stage instruction means 6 Low output instruction means A Automatic transmission E Engine

Claims (1)

[Claims] 1. A control device for an automatic transmission for a vehicle, which is connected to an engine through a fluid coupling and is capable of executing a gear shift instructed by manually operating a shift operating means. An oil temperature determination means for detecting or estimating, a start shift speed detecting means for detecting a shift speed when starting by manual operation, and a manual operation when the oil temperature detected or estimated by the oil temperature determining means is equal to or higher than a predetermined temperature. And a low-speed gear indicating means for outputting to set the gear speed at the time of starting at a lower gear than the gear detected by the start gear detecting means, and a lower gear than the gear detected by the start gear detecting means. And a low-output instruction means for changing the output of the engine to a low output when the low-speed instruction means outputs the low-speed instruction means.