JPH08247271A - Speed change controller for automatic transmission - Google Patents

Abstract

PURPOSE: To prevent power-on-off from erroneous judgement by selecting either one of a plurality of power-on-off judging means for speed change control on the basis of the output driven rotational speed of an automatic transmission just before the input of a speed change signal. CONSTITUTION: During 1 speed stage travelling, TCU 7 reads the input information from an engine rotational speed sensor 8, throttle sensor 11, transfer drive gear rotational speed sensor 14 and ECU 6. Next, when an up-shift signal from the 1 speed stage to 2 speed stage is detected, the TCU 7 searches the transfer drive gear rotational speed just before the input of the up-shift signal to judge whether or not the value is below a threshold value for the judgement. Then, the TCU 7 judges whether or not the present running condition corresponds to power-on from the throttle opening and engine rotational speed. If the judgement shows Yes, the up-shift is carried out by the use of the control logic for power-on and If No is shown, the up-shift is carried out by the use of the control logic for the power-off.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shift control device for an automatic transmission used in an automobile, and more particularly to a technique for preventing erroneous power on / off determination.

[0002]

2. Description of the Related Art In automatic transmissions for automobiles, generally, a speed change mechanism using a planetary gear is used, and a hydraulic friction engagement element such as a hydraulic wet multi-plate clutch or brake engages or disengages a sun gear or a planetary carrier. The gear is released to obtain the desired gear.

Normally, the hydraulic friction engagement element of an automatic transmission uses a line pressure generated by a hydraulic pump that rotates together with the crankshaft of the engine as a drive source. In the electronically controlled type, the drive control is performed by an electromagnetic hydraulic control. A valve (hereinafter referred to as a solenoid valve) is used. That is, a TCU (transmission control unit) duty-controls a solenoid valve that supplies and discharges hydraulic oil to and from a hydraulic friction engagement element, and increases or decreases the control hydraulic pressure to be supplied at a predetermined ratio to engage a hydraulic clutch and a hydraulic brake. Or release. The gear shift is performed by switching the hydraulic clutch and hydraulic brake that operate, that is, by engaging one hydraulic friction engagement element while releasing the other hydraulic friction engagement element. For example, when shifting down from the fourth speed to the third speed, the hydraulic friction engagement element (disengagement side engagement element) that establishes the fourth speed is disengaged and the hydraulic pressure that establishes the third speed. The friction engagement element (coupling side engagement element) is engaged.
By this gripping operation of the hydraulic friction engagement element, the transmission path of the engine torque is switched, and the downshift is completed.

In addition, in the electronically controlled automatic transmission, a shift map is used for selecting the shift speed with the rotational speed NO (that is, the vehicle speed V) of the transfer drive gear integrated with the output shaft and the opening degree θTH of the throttle valve as parameters. From this shift map, the TCU selects the optimum gear stage (target gear stage) for the current operating state, and at the same time the power-on state (engine speed) based on load information from the ECU (engine control unit). It is determined whether the rotation speed is higher than the input shaft rotation speed of the automatic transmission) or the power-off state (the engine rotation speed is lower than the input shaft rotation speed of the automatic transmission). The control logic is switched based on the determination result to supply / discharge the control hydraulic pressure to / from the hydraulic friction engagement element.

For example, when performing an up-shift, in the power-off state, the input shaft rotation speed decreases only by releasing the disengagement side engagement element. Therefore, the hydraulic pressure to the disengagement side engagement element is reduced at the initial stage of gear shift, while the coupling side engagement element is supplied with a very low hydraulic pressure. Then, when the input shaft rotation speed matches the synchronous rotation speed of the target shift speed,
The hydraulic pressure to the coupling side engagement element is increased to complete the engagement, and the shift is completed. However, in the power-on state, the engine is blown up (runup) only by releasing the disengagement side engagement element, and the input shaft rotation speed is rapidly increased. Therefore, when the low hydraulic pressure is supplied to the coupling side engagement element, the hydraulic pressure is rapidly increased by the feedback control, and a large shift shock (run-up shock) occurs at the time of engagement. Therefore, a relatively high hydraulic pressure is supplied to the coupling side engagement element from the initial stage of gear shifting,
By matching the start timings of the disengagement of the disengagement side engagement element and the engagement of the coupling side engagement element, the input shaft rotation speed is reduced to the synchronous rotation speed of the target shift speed.

[0006]

By the way, in order to determine whether the engine is in the power-on state or the power-off state, load information such as the throttle opening θTH and the engine rotation speed Ne are generally used. . That is, when the engine rotation speeds Ne are the same, it is determined that the power is on when the load is large, and the power is off when the load is small. At this time, if it is determined that the power-off state is set in spite of the power-on state, the run-up shock may occur during the upshift as described above. Therefore, conventionally, such a problem has been prevented by using a map in which a wide power-on determination region is set in consideration of variations in engine performance and poor adjustment of the throttle opening sensor.

However, even if such a method is adopted, shift shock may occur during upshifting, as described below. That is, when the operation of releasing the throttle pedal from the depressed state (so-called lift foot operation) is performed, the power-on determination area is set wide and the return of the throttle valve is delayed due to the action of the dashpot. Together with this, there is a possibility that it may be determined to be power-on for a while even though it is power-off as an operating state. Then, as described above, the relatively high hydraulic pressure is supplied to the coupling side engaging element, so that the engagement of the coupling side engaging element progresses rapidly. as a result,
Since the driving torque on the engine side is small, the turbine rotation speed NT is instantly lowered, and a large shift shock occurs at the time of engagement. It should be noted that this malfunction of the lift foot is caused by a faulty setting of the throttle sensor when the vehicle is equipped with an engine that does not have an idle switch that detects the fully closed state of the throttle valve, such as a diesel engine or a gasoline engine with a carburetor. It becomes particularly remarkable due to the above.

The present invention has been made in view of the above situation, and uses a power on / off determination means properly based on the output shaft rotation speed immediately before a shift signal is input, thereby preventing an erroneous power on / off determination. The purpose is to provide.

[0009]

In order to achieve this object, therefore, according to claim 1 of the present invention, an automatic transmission which is connected to an internal combustion engine and performs a shift control according to the power on / off state of the internal combustion engine. In the shift control device of the above, a plurality of power-on / off determining means for determining whether the internal combustion engine is in a power-on state or a power-off state based on the rotation speed and the load of the internal-combustion engine; It is proposed to provide a selection means for selecting any one of the plurality of power on / off determination means for the shift control based on the output shaft rotation speed of the automatic transmission.

According to a second aspect of the present invention, in the shift control device according to the first aspect, the plurality of power-on / off determining means are at least a first determining means having a wide power-on determining area and a power-off determining area. It is proposed that the selection means includes a wide second determination means and selects the first determination means when the output shaft rotation speed is equal to or lower than a predetermined value.

According to a third aspect of the present invention, in the shift control device according to the first aspect, the plurality of power-on / off determining means include at least a first determining means having a wide power-on determining area and a power-off determining area. It is proposed that the selection means includes a wide second determination means and selects the second determination means when the output shaft rotation speed is higher than a predetermined value.

[0012]

According to the first aspect of the present invention, for example, after selecting one of a plurality of power on / off determination lines on the determination map based on the output shaft rotation speed immediately before the input of the shift signal, the selected power on / off determination is performed. From the line, it is determined whether the power-on state or the power-off state is based on the rotation speed and load of the internal combustion engine, and shift control is performed according to the determination result.

In the second aspect, for example, when the output shaft rotation speed is equal to or lower than a predetermined value, a power-on / off determination line having a wide power-on determination area is used to prevent erroneous determination on the power-off side. Further, in claim 3, for example, when the output shaft rotation speed is higher than a predetermined value, a power-on determination line is used to prevent an erroneous determination on the power-on side.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings. FIG. 1 is a schematic configuration diagram of a power plant to which a shift control device for an automatic transmission according to the present invention is applied. In FIG. 1, 1 is a gasoline engine with an electronically controlled carburetor for an automobile (hereinafter, simply referred to as an engine),
An automatic transmission 2 having four forward gears is connected to the rear end thereof, and the output of the engine 1 is transmitted to the drive wheels (not shown) via the automatic transmission 2. The automatic transmission 2 is composed of a torque converter 3, a transmission main body 4, and a hydraulic controller 5. The transmission main body 4 incorporates hydraulic friction engagement elements such as a hydraulic clutch and a hydraulic brake in addition to a plurality of sets of planetary gears. In addition to the integrally formed hydraulic circuit, the hydraulic controller 5 also houses a plurality of solenoid valves for hydraulic control. The engine 1 and the automatic transmission 2 are each an ECU including an input / output device (not shown), a storage device (ROM, RAM, BURAM, etc.) containing a large number of control programs, a central processing unit (CPU), a timer counter, etc.
Drive control is performed by an (engine control unit) 6 and a TCU (transmission control unit) 7.

On the input side of the ECU 6, a crank angle sensor 8 for detecting the engine speed Ne and the crank angle of each cylinder, a water temperature sensor 9 for detecting the cooling water temperature TW, and a throttle sensor 11 for detecting the throttle opening θTH. In addition to the above, various sensors and switches not shown are connected. On the other hand, the torque converter 4 is connected to the input side of the TCU 7.
Turbine shaft rotation speed (input shaft rotation speed) NT
Sensor 13 for detecting the speed of the vehicle, and NO sensor 14 for detecting the rotational speed NO of the transfer drive gear instead of the vehicle speed V.
Besides, various sensors and switches such as an oil temperature sensor and an inhibitor switch are connected. Further, the ECU 6 and the T
It is connected to the CU 7 by a signal cable 15 and exchanges information with each other by serial communication. The ECU 6 then, based on various input information,
Comprehensive control of the engine 1 such as air-fuel ratio feedback control and idle-up control is performed. In addition, the TCU 7 also drives the hydraulic friction engagement element in the transmission main body 4 via the hydraulic controller 5 based on the input information to control the shift of the automatic transmission 2.

The procedure of upshift control in this embodiment will be described below with reference to the flowcharts of FIGS. 2 and 3 and the maps of FIGS. TC while driving in 1st gear
U7 firstly performs the various sensors and E described above in step S1.
Input information from the CU 6 is read into the RAM. Next, TC
U7 determines whether or not an upshift signal (1-2 upshift signal) from the first gear to the second gear has been detected in step S2, and if the determination is No (negative), proceeds to step S1. Return Continue reading input information. And 1
When the -2 upshift signal is detected and the determination in step S2 becomes Yes (affirmative), the TCU 7 searches the transfer drive gear rotation speed N0 stored in the RAM in step S3 immediately before the input of the upshift signal, It is determined whether or not the value is equal to or less than a predetermined determination threshold NOa (420 rpm in this embodiment). Here, the determination threshold NOa is
As shown in the upshift map of FIG. 4, it is set to be equal to the lower limit rotation speed of the 1-2 upshift determination line. Therefore, if the determination in step S3 is Yes, it can be determined that the 1-2 upshift determination line has been crossed from left to right due to the increase in the transfer drive gear rotation speed NO.

At this time, the TCU 7 executes the step S5.
In the power-on / off judgment map of FIG. 5, after setting the first judgment line L1 shown by the solid line with a wide power-on region to be used, in step S7, the current operation is determined from the throttle opening θTH and the engine speed Ne. Determine if the state is power on. If the determination is Yes, the TCU 7 performs upshift using the power-on control logic in step S9, and if No, upshift using the power-off control logic in step S11. To do. As a result, there is no risk of determining that the power-off state is in spite of the power-on state, and the run-up shock described above is prevented.

On the other hand, when the determination in step S3 is No, the 1-2 upshift signal is detected and the transfer drive gear rotation speed NO is larger than the determination threshold NOa, so the accelerator pedal is pressed. It can be determined that the lift foot is released to cross the 1-2 upshift determination line from the high load side to the low load side. Therefore, the TCU7 is likely to be in the power-off state.
Is set in step S13 to use the second determination line L2 having a wider power-off area indicated by the broken line in the power-on / off determination map of FIG. 5, and then step S15
Then, it is determined from the throttle opening θTH and the engine speed Ne whether the current operating state is power-on. Then, if this determination is Yes, the TCU 7 performs the upshift using the control logic for power-on in step S17, and if the determination is No, the upshift is performed using the control logic for power-off in step S19. To do. As a result, there is no risk of determining that the power-on state is set in spite of the power-off state, and shift shock due to lift-up is prevented.

By the way, the determination of Yes in step S3 is generally made in the power-on state, but it can also occur in the accelerator released state and when the transfer drive gear rotation speed NO increases during the downhill. in this case,
Although the operating state is power off, if the transfer drive gear rotation speed NO is larger than the determination threshold NOa, the determination in step S3 becomes No, and the second determination line L2 having a wider power off region is selected, There will be no problem as it matches the condition. On the other hand, when the transfer drive gear rotation speed NO is smaller than the judgment threshold value NOa, the first judgment line L1 having a wider power-on region is selected. However, since the transfer drive gear rotation speed NO is small, the throttle valve is operated due to the lift foot operation. Even if the dashpot, which slows the return of the car, acts, it does not cross the 1-2 upshift determination line. Therefore, in this case, since the 1-2 upshift signal is not output, there is no particular problem even if the first determination line L1 is selected on the power on / off determination map. Further, after finishing the lift foot operation, the transfer drive gear rotation speed N
When O rises and crosses the 1-2 upshift determination line, a Yes determination is made in step S3, and the first determination line L1 with a wider power-on region is selected, and the throttle opening for the engine speed Ne is opened. Since the degree θTH is also small enough, despite being in the power off state,
There is no risk of determining that the power is on.

While traveling at the second speed, the TCU 7 first reads into RAM the input information from the various sensors and the ECU 6 described above in step S21. Next, the TCU 7 determines in step S22 that the upshift signal (2
-3 upshift signal) is detected,
If the determination is No, the process returns to step S21 to continue reading the input information. When the 2-3 upshift signal is detected and the determination in step S22 is Yes,
The TCU 7 searches the transfer drive gear rotation speed NO immediately before the input of the upshift signal stored in the RAM in step S23, and the value is a predetermined determination threshold NOb.
(In this embodiment, it is determined whether it is 750 rpm or less. Here, the determination threshold NOb is set to be equal to the lower limit rotation speed of the 2-3 upshift determination line, as shown in the upshift map of FIG. Therefore, also in this case, as in the upshift from the first gear to the second gear,
If the determination in step S23 is Yes, there is no risk of determining that the power is on due to the lift foot operation despite the power being off.

If the determination in step S23 is Yes, the TCU 7 uses the first determination line L1 shown in the solid line in which the power-on region is wide in the power-on / off determination map in FIG. 5 in step S25. After setting, in step S27 the throttle opening θTH and the engine speed N
It is judged from e and whether the current operating condition is power on. Then, if this determination is Yes, the TCU 7 performs upshift using the power-on control logic in step S29, and if No, step S3.
At 1, the control logic for power off is used for upshifting. As a result, there is no risk of determining that the power-off state is in spite of the power-on state, and the run-up shock described above is prevented.

On the other hand, if the determination in step S23 is No, in step S33, the TCU 7 uses the second determination line L2 shown in the broken line in which the power off region is wide in the power on / off determination map of FIG. After setting, in step S35 the throttle opening θTH and engine speed N
It is judged from e and whether the current operating condition is power on. Then, if this determination is Yes, the TCU 7 performs upshift using the power-on control logic in step S37, and if No, step S3.
At 9, an upshift is performed using the control logic for power off. As a result, there is no possibility of determining that the power-on state is set in spite of the power-off state, and the shift shock caused by the lift-up operation is prevented.

As described above, in the shift control device of this embodiment, it is determined whether the transfer drive gear rotation speed NO immediately before the input of the upshift signal is less than or equal to the predetermined determination threshold value, and the power on / off is determined according to the determination result. By using the two power-on / off judgment lines properly in the judgment map, it is possible to prevent the above-mentioned run-up shock and shift shock caused by lift-up operation.

Although the description of the specific embodiments has been completed, the embodiments of the present invention are not limited to the above embodiments. For example, in the above embodiment, the present invention is applied to the upshift from the first gear to the second gear and the upshift from the second gear to the third gear. It may be applied to shifts or the like, or may be applied to downshifts. Further, in the above embodiment, two power on / off determination lines are provided in the power on / off determination map, but three or more power on / off determination lines may be provided. Further, the power on / off determination line may be one, and the power on / off determination may be performed after adding or subtracting a predetermined value to the load of the internal combustion engine according to the output shaft speed immediately before the input of the shift signal. Further, the specific control procedure can be changed without departing from the gist of the present invention.

[0025]

As described above in detail, according to the shift control device of the first aspect of the present invention, an automatic shift that is connected to an internal combustion engine and performs shift control according to the power on / off state of the internal combustion engine. And a plurality of power-on / off determining means for determining whether the internal combustion engine is in a power-on state or a power-off state on the basis of the rotation speed and the load of the internal combustion engine, immediately before the input of a shift signal. Since the selection means for selecting one of the plurality of power on / off determination means for the shift control based on the output shaft rotation speed of the automatic transmission is provided, the accuracy of the power on / off determination is improved. To do.

According to the speed change control device of the second aspect,
2. The shift control device according to claim 1, wherein the plurality of power-on / off determination means include at least a first determination means having a wide power-on determination area and a second determination means having a wide power-off determination area, and the selection means. When the output shaft rotation speed is equal to or lower than the predetermined value, the first determining means is selected, so that an erroneous determination on the power-off side does not occur and a run-up shock is prevented.

According to the speed change control device of the second aspect,
2. The shift control device according to claim 1, wherein the plurality of power-on / off determination means include at least a first determination means having a wide power-on determination area and a second determination means having a wide power-off determination area, and the selection means. When the output shaft rotation speed is higher than the predetermined value, the second determination means is selected, so that an erroneous determination on the power-on side does not occur and a shift shock caused by a lift-up operation is prevented.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a power plant to which a shift control device according to the present invention is applied.

FIG. 2 is a flowchart showing a shift control procedure in the embodiment.

FIG. 3 is a flowchart showing a shift control procedure in the embodiment.

FIG. 4 is an upshift map used in the embodiment.

FIG. 5 is a power on / off determination map used in the embodiment.

[Explanation of symbols]

 1 Engine 2 Transmission 5 Controller 6 ECU 7 TCU 8 Ne Sensor 11 Throttle Sensor 13 NT Sensor 14 NO Sensor 15 Signal Cable

Front page continuation (72) Inventor Nobuyuki Katayama 5-3-8 Shiba, Minato-ku, Tokyo Mitsubishi Motors Corporation

Claims (3)

[Claims] 1. A shift control device for an automatic transmission, which is connected to an internal combustion engine and performs shift control according to a power-on / off state of the internal combustion engine, wherein the internal combustion engine is controlled based on a rotational speed and a load of the internal combustion engine. A plurality of power on / off determining means for determining whether the power is on or off, and one of the plurality of power on / off determining means based on the output shaft rotation speed of the automatic transmission immediately before the input of the shift signal. A shift control device for an automatic transmission, comprising: a selecting unit that selects one for the shift control. 2. The plurality of power on / off determination means,
At least a first determination means having a wide power-on determination area and a second determination means having a wide power-off determination area are included, and the selection means has the first determination means when the output shaft rotation speed is equal to or lower than a predetermined value. 2. The shift control device for an automatic transmission according to claim 1, wherein 3. The plurality of power on / off determination means,
At least a first determination means having a wide power-on determination area and a second determination means having a wide power-off determination area are included, and the selection means, when the output shaft rotation speed is higher than a predetermined value, the second determination means. 2. The shift control device for an automatic transmission according to claim 1, wherein