JPS61119857A - Gear shifting control method for automatic transmission gear for vehicle - Google Patents

Abstract

PURPOSE:To prevent excessive decrease of the number of gear shifting steps resulting from prevention of the occurrence of gear shift hunting, by a method wherein it is prohibited that the gear shifting step of an auxiliary transmission gear is shifted to a high speed step through control of a switch only when a main transmission gear is shifted to a maximum speed gear shift step. CONSTITUTION:A geared transmission gear 7 is formed such that an auxiliary geared transmission gear 10 and a main geared transmission gear 11 are coupled in series with each other, and the auxiliary geared transmission gear 10 is a transmission gear for overdrive. An electronic control device 60 outputs an ON-OFF signal to a solenoid valve 46 for direct coupling clutch and a solenoid valve 48 for an auxiliary transmission gear and a pulse signal in a given ratio to a solenoid valve 42 for line oil pressure and a solenoid 51 for a main transmission gear. A transmission control switch 65 is controlled by an operator, and shifting of an overdrive step is prohibited during the OFF-state of the switch 65.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a method of controlling an automatic transmission with 8 positions used in vehicles such as automobiles, and particularly relates to a method for controlling automatic transmissions with 8 positions used in vehicles such as automobiles, and in particular, a method for controlling automatic transmissions in which a main transmission and an auxiliary transmission are connected in a power transmission path. The present invention relates to a speed change control method for automatic transmissions for vehicles that are arranged in series with each other.

Conventional technologyAs one of the automatic transmissions used in vehicles such as automobiles,
A main transmission that switches between at least two gears and a sub-transmission that switches between two gears are arranged in series with each other when viewed from a power transmission path, and the gear of the main transmission is the highest. An automatic vehicular transmission configured to switch the gear position of the sub-transmission device between two gear positions when the high speed gear is in place and at least one other gear to obtain a large number of gear positions. has already been proposed in Japanese Patent Application No. 46-26604 (Japanese Unexamined Patent Publication No. 47-39861@) and Japanese Patent Application No. 4-176299 by the same applicant as the present applicant.

Problems to be Solved by the Invention During high-speed, high-load operation such as when traveling uphill, when the accelerator pedal is depressed, the sub So-called gear hunting, in which the gear of the transmission device repeatedly switches between a high gear and a low gear, may occur. In the so-called automatic transmission with overdrive, which is configured so that the sub-transmission changes from a low gear to a high gear only when the gear of the main transmission is at the highest gear, the above-mentioned gear hunting occurs. In order to prevent this from occurring, it may be completely prohibited for the auxiliary transmission to shift from a low gear to a high gear by switch operation. In automatic transmissions for vehicles that are configured to shift at different speeds, if switching to a high speed gear in the auxiliary gear position is completely prohibited by switch operation, a useful intermediate gear can also be achieved. Therefore, the multi-speed configuration becomes meaningless.

Means for Solving the Problems The shift control method for an automatic transmission for a vehicle according to the present invention includes a main transmission device that switches between at least two gear stages and a sub-transmission device that switches between two gear stages. In a speed change control method for automatic transmissions for a vehicle that are arranged in series with each other in a power transmission path, when the gear position of the main transmission device is the highest speed gear position and when the gear position is at least one other gear position, the above-mentioned D
The gear of the J transmission is changed between two gears, and the gear of the auxiliary transmission is changed to a high gear only when the gear of the main transmission is the highest gear by a switch operation. It is characterized by prohibition.

Effects of the Invention According to the shift control method according to the present invention, the shift of the sub-transmission gear to a high gear by switch operation is prohibited only when the gear of the main transmission is at the highest gear. Therefore, even if a switch is operated to prevent gear hunting, it will only prevent the establishment of an overdrive gear in which the main transmission is in the highest gear and the auxiliary transmission is in the high gear. , a useful intermediate gear is selectively established, and the number of gears is not excessively reduced to prevent gear hunting.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described in detail by way of embodiments with reference to the accompanying drawings.

FIG. 1 schematically shows the structure of an automatic transmission for a vehicle to which the control method according to the present invention is applied. The automatic transmission 1 is
Pump impeller 3, turbine impeller 4, and stator impeller 5
The input member of the hydraulic torque converter 2 includes a three-element, one-stage, two-phase general hydraulic torque converter 2 with a direct-coupled clutch, and a gear transmission @ 7 as an auxiliary transmission. The pump impeller 3 is drivingly connected to the output shaft 101 of the internal combustion engine 10o, and the turbine blade 1i4, which is the output member of the hydraulic torque converter 2, is drivingly connected to the input shaft 9 of the gear transmission @7. The output shaft 8 of 7 is drivingly connected to a drive wheel (not shown) of a vehicle via a differential gear.

The gear transmission 7 has a 0'' gear transmission 10 and a main gear transmission 11 in series with each other.

The auxiliary gear transmission 10 is an overdrive gear transmission in a conventional 4th-speed automatic transmission.
2, and a ring gear 13 provided concentrically with the sun gear 12.
, a planetary pinion 14 that is located between the sun gear 12 and the ring gear 13 and meshes with the two, a carrier 15 that rotatably supports the planetary pinion 14, and a one-way clutch (Fo) that prevents the carrier 15 from rotating counterclockwise with respect to the sun gear 12. ) 16 and an OD clutch that selectively connects the sun gear 12 and carrier 15 <Go)
17 and an OD brake (Bo) 18 for selectively fixing the sun gear 12 to the transmission case, the carrier 15 is drivingly connected to the input shaft 9, and the oD brake (Bo) 18 selectively fixes the sun gear 12 to the transmission case.
By selectively engaging the clutch 17 and the OD brake 18, it is possible to switch between two gear stages.

The main gear transmission 11 includes a front sun gear 20 and a rear sun gear 21 that are connected to each other by one intermediate shaft.
A front ring gear 22 provided concentrically with the front sun gear 20, a rear ring gear 23 provided concentrically with the rear sun gear 21, and a front planetary binion located between the front sun gear 20 and the front ring gear 22 and meshing with both. 24, a rear planetary binion 25 that is located between the rear sun gear 21 and the rear ring gear 23 and meshes with them, a front carrier 26 that rotatably supports the front planetary binion 24, and a rear planetary binion 25 that is rotatable. The rear carrier 27 supported on
a forward clutch (C+>28) that selectively connects the ring gear 13, which is an output member, in a torque transmission relationship; and a direct clutch (C2) 29 that selectively connects the intermediate shaft 19 and the ring gear 13 in a torque transmission relationship. , a shift brake (B+) 30 that selectively fixes the intermediate shaft 19 to the transmission case, and a rear carrier 2.
Another shift brake (B2) 31 selectively fixes the rear carrier 27 to the transmission case, and a one-way clutch (F2) that locks the left rotation of the rear carrier 27.
l) 32, the front carrier 26 and the rear ring gear 23 are drivingly connected to the output shaft 8, and the plurality of clutches and the plurality of brakes are engaged and released in a predetermined combination. This allows switching between a plurality of gears, including three forward gears and one reverse gear.

The gear transmission 17 is connected to the auxiliary gear transmission W110 by engaging and disengaging the plurality of clutches and the plurality of brakes of the auxiliary gear transmission 10 and the main gear transmission @11 according to the table shown below. In cooperation with the main gear shift @ff111, a plurality of gears including three forward gears including an overdrive gear and one reverse gear are selectively achieved.

- 0XOX××Δ△ D 2nd speed □xxxxo△x 3rd speed
0XOO×××Δn 4th gear 0OOX
×××△ 5th connection ooxxxxoxx - speed □x□xxxx△△ S 2nd speed 0xxxxOOΔ×'Cold 3rd speed
oxooxxxΔL -th speed QxQ
xQxΔ△1'4) 2nd speed QXXXOO
Δ× In this table, the O mark indicates that the relevant clutch or brake is engaged, the X mark indicates that the relevant clutch or brake is released, and the Δ mark indicates that the relevant one-way clutch is connected to the internal combustion engine. This indicates that it is engaged (locked) during engine drive to drive the drive wheels from the side, and released (free) during engine braking, where the internal combustion engine is driven from the drive wheels side.

In addition, in the HI range, an upshift to the second speed is not performed, and only a downshift from the second speed to the first speed is performed.

In the auxiliary gear transmission 10, when the oD brake 18 is released and the OD clutch 17 is engaged, the sun gear 12 and carrier 1
5 is connected, a direct gear is achieved, whereas when the OD clutch 17 is released and the OD brake 18 is engaged, and the sun gear 12 is fixed to the transmission case, an increased gear is achieved. . As is clear from the table above, in the auxiliary gear transmission 1°, when both the forward clutch 28 and the direct clutch 29 are engaged and the gear position of the main gear transmission 11 is the highest speed gear (directly coupled gear). When the forward clutch 28 is engaged and the gear position of the main gear transmission 11 is the lowest gear (first gear), the gear is switched between the direct gear and the increasing gear, and the main gear transmission 11 When the gears of the main gear transmission 11 are the second gear and the third gear, the gears are fixed to the direct gear, so that in addition to the overdrive gear which is the fifth gear, the lowest gear of the main gear transmission 11 and the lower gear are fixed. Another gear on the high speed side (conventional second gear)
Another gear stage is established between the two, and as a result, forward transmission is established as a whole.

The gear ratio of the lowest gear of the main gear transmission v1111 is set to 2.
826, when the gear ratio of the intermediate gear is 1.532, the gear ratio of the highest gear is 1.000, and the gear ratio of the increasing gear of the auxiliary gear transmission 10 is 0.705, the second gear The gear ratio of the gears is 1.992.

Direct coupling clutch 6 incorporated in fluid torque converter 2
The clutches 17, 28, 29, and brakes 18, 30, and 31 of the auxiliary gear transmission Wt10, the main gear transmission 1, and the brakes 18, 30, and 31 are each of a hydraulically operated type that is driven by a hydraulic servo device and selectively engaged. The vehicle speed and throttle opening are controlled for each manual shift range by a hydraulic control device that controls the supply and discharge of hydraulic pressure to and from the hydraulic servo device, and an electronic control device that includes a microcomputer that instructs switching of the oil path of the hydraulic control device. By engaging and disengaging the clutch and the brake in the above-described combination according to a predetermined shift pattern according to the speed, the gear position of the gear transmission 7 is switched and set, and the gear position of the direct coupling clutch 6 is set. Engagement and disengagement occur. An example of a shift pattern in the D range is shown in FIG.

FIG. 2 shows one embodiment of a control device for a vehicle automatic transmission used to implement the control method according to the present invention.

In FIG. 2, 4o indicates a hydraulic control device, and 60 indicates an electronic control device.

The hydraulic control device 40 includes an oil pump 41 driven by an internal combustion engine 100 that is drivingly connected to the pump impeller 3 of the hydraulic torque converter 2, and is supplied with hydraulic pressure from the oil pump 41, and controls the internal combustion engine 100 by controlling the duty ratio.
A line oil pressure solenoid valve 42 generates a predetermined line oil pressure according to the output state of the line oil pressure, a manual shift valve 44 that is manually operated by a manual shift lever 43 to set a manual shift range, and the engagement of the direct coupling clutch 6. A direct coupling clutch control valve 45 for disengaging, a direct coupling clutch solenoid valve 46 for controlling switching of the direct coupling clutch control valve 45, and an OD clutch 17 of the auxiliary gear transmission 10.
and an auxiliary transmission that performs switching control of the auxiliary transmission shift valve 47 that selectively supplies hydraulic pressure to either one of the OD brake 18 and the auxiliary gear transmission 10 to change the gear stage of the auxiliary gear transmission 10. a first shift valve 49 and a second shift valve 5o that control the supply and discharge of hydraulic pressure to the first clutch 28, direct clutch 29, and shift brakes 30 and 31 of the main gear transmission 11; The main transmission solenoid valve 51 includes a main transmission solenoid valve 51 that controls switching of the valve 49 and the second transmission valve 60 .

The sub-transmission speed change valve 47 is composed of a spool valve,
Switching is performed depending on whether or not a predetermined control oil pressure is being supplied to the control boat, and the control oil pressure is supplied to the control boat in an on-off manner by the sub-transmission solenoid valve 48. It has become.

For example, when the solenoid valve 48 is energized, the control oil pressure is supplied to the control boat of the sub-transmission speed change valve 47, and the speed change valve is switched to a position where the speed increase is achieved, thereby causing the sub-gear transmission 10 becomes an increasing speed, and on the other hand, when the solenoid valve 48 is not energized, the control oil pressure of the control boat of the sub-transmission control valve 47 is discharged, and the speed change valve achieves the direct gear. At this time, the auxiliary gear transmission 10 achieves a direct gear position.

The first speed change valve 49 and the second speed change valve 50 are configured to be switched individually depending on the height of the control oil pressure supplied to the control boat. The second speed change valve 50 is switched depending on whether or not a control oil pressure of a first predetermined value P+ is supplied, and the second speed change valve 50 is switched depending on whether a control oil pressure of a second predetermined value P2 higher than the first predetermined value P+ is supplied to its control boat. It is designed to change depending on whether it is on or off. The main transmission solenoid valve 51 generates control hydraulic pressure to be supplied to the control ports of the first transmission valve 49 and the second transmission valve 50 by duty ratio control,
The solenoid valve generates a hydraulic pressure of a first predetermined value P+ when driven by a pulse signal with a duty ratio of a first value R+, and when driven by a pulse signal with a duty ratio of a second value R2. the second predetermined value P
It is designed to generate 2 hydraulic pressure.

Incidentally, the above-mentioned speed change valve and its control device were developed in U.S. Pat.
26596 (Utility Model Publication No. 58-38186) and Japanese Patent Application No. 55-107260 (Japanese Patent Application No. 56-24246), if a more detailed explanation is required, Please refer to the publications of these applications.

The electronic i+IJ tell device 60 turns on the direct coupling clutch solenoid valve 46 and the sub-transmission solenoid valve 48.
An off signal is output, and a pulse signal with a predetermined duty ratio is output to the line oil pressure solenoid valve 42 and the main transmission solenoid valve 51, and these controls are provided by the throttle opening sensor 61. internal combustion engine 1
Information regarding the throttle opening of 00 and the vehicle speed sensor 62
This is performed according to a predetermined flowchart in accordance with information regarding the vehicle speed provided by the shift position sensor 64, information regarding the manual shift range provided by the shift position sensor 64, and information regarding on/off of the switch provided by the transmission control switch 65. ing.

The transmission control switch 65 is operated by the driver to issue an instruction to prohibit the establishment of the fifth gear, that is, the overdrive gear, and when the switch is in the OFF state, the establishment of the overdrive gear is prohibited. .

Note that the throttle opening degree is used as information representative of the engine output, and this may be the amount of depression of the accelerator pedal or the torque of the engine output shaft.

Next, an example of the procedure for controlling the speed change of an automatic transmission for a vehicle according to the present invention will be described with reference to the flowchart shown in FIG. The flowchart shown in FIG. 3 shows the control routine when setting the D range as a rear frame.

In step 11, it is determined whether the manual shift range is the D range. If the D range is selected, the process proceeds to step 12, whereas if the D range is not selected, the D range control routine is skipped and the process proceeds to the next control routine step.

In step 12, it is determined whether the gear position of the main gear transmission 11 is the highest gear position.

If the gear position of the main gear transmission 11 is the highest gear position, the process advances to step 13;
If the first gear is not the highest gear, the process advances to the next control step.

In step 13, it is determined whether the gear position of the auxiliary gear transmission 10 is a high gear position.

If the gear position of the auxiliary gear transmission 1o is a high gear position, the process advances to step 14, whereas if the gear position of the auxiliary gear transmission 10 is not a high gear position, the process advances to the next step of the control routine.

In step 14, it is determined whether the transmission control switch is in the OFF state. When this switch is off, the process proceeds to step 15, whereas when it is not off, the process proceeds to the next step of the control routine.

In step 15, the gear position of the auxiliary gear transmission @10 is forcibly changed from the high speed position to the low speed position while the direct coupling clutch is released.

After step 15, the process proceeds to the next step of the control routine.

By performing control according to the flowchart as described above, when the transmission control switch is in the OFF state, the establishment of the fifth gear (overdrive gear) is prohibited without preventing the establishment of the second gear.

Although the present invention has been described in detail with respect to specific embodiments above, the present invention is not limited thereto.
It will be apparent to those skilled in the art that various embodiments are possible within the scope of the invention.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram showing one embodiment of an automatic transmission for a vehicle used to implement the speed change control method according to the present invention, and FIG. 2 is a hydraulic control diagram used to implement the speed change control method according to the present invention. A schematic configuration diagram showing one embodiment of an IA system and an electronic control device, FIG. 3 is a flowchart showing an example of the implementation procedure of the speed change control method for an automatic transmission for a vehicle according to the present invention, and FIG. 4 shows a D range speed change. FIG. 3 is a shift diagram showing an example of a pattern. 1...Automatic transmission for vehicles, 2...Hydraulic torque converter, 3...Pump impeller, 4...Turbine impeller. 5... Stator impeller, 6... Direct clutch, 7...
...Gear transmission, 8...Output shaft, 9...Input shaft,
DESCRIPTION OF SYMBOLS 10... Secondary gear transmission, 11... Main gear transmission, 12... Sun gear, 13... Ring gear, 14...
...Planetary Binion, 15...Carrier, 16.
...One-way clutch, 17...OD clutch, 1
8...OD brake. 19... Intermediate shaft, 20... Front sun gear, 21
...Rear sun gear, 22...Front ring gear,
23... Rear ring gear, 24... Front planetary binion, 25... Rear planetary binion, 2
6...Front carrier, 27...Rear carrier,
28...Forward clutch, 29...Direct clutch. 30.31... Shift brake, 32... One-way clutch, 40... Hydraulic control device, 41... Oil pump, 42... Line hydraulic solenoid valve, 4
3...Manual shift lever 144...Manual shift valve, 45...Direct clutch control valve, 46...
・Solenoid valve for direct coupling clutch, 47... Speed change valve for auxiliary transmission, 48... Solenoid valve for auxiliary transmission, 49...
- First speed change valve, 50... Second speed change valve, 51... Main transmission solenoid valve, 60... Electronic control device, 61
...Throttle opening sensor, 62...Vehicle speed sensor,
64...Shift position sensor, 65...Transmission control switch Patent applicant: Toyota Motor Corporation representative
Attorney Patent Attorney Masatake Akashi 2nd Figure 3

Claims (1)

[Claims] In a shift control method for an automatic transmission for a vehicle having a main transmission that switches between at least two gears and a sub-transmission that switches between two gears that are in series with each other when viewed from a power transmission path. , when the gear of the main transmission is the highest gear and at least one other gear, the gear of the auxiliary transmission is switched between two gears, and the main gear is changed by a switch operation. A shift control method, characterized in that the shift gear of the sub-transmission device is prohibited from switching to a high gear only when the gear gear of the device is the highest gear.