JPH0586513B2 - - Google Patents

Description

[Detailed description of the invention]

INDUSTRIAL APPLICATION FIELD The present invention relates to a method of controlling an automatic transmission used in a vehicle such as an automobile, and particularly to an anti-creep and hill hold control method when the vehicle is temporarily stopped. 2. Description of the Related Art Automatic transmissions used in vehicles such as automobiles generally include a hydraulic torque converter that receives rotational power from an internal combustion engine, and a plurality of frictional engagement devices that receive rotational power from the hydraulic torque converter. It has a planetary gear type gear transmission that can be switched between a plurality of gears by engagement and disengagement, and the gear transmission has a predetermined shift pattern according to the vehicle speed and the amount of depression of the accelerator pedal. Therefore, the gears can be changed. Conventionally, in the automatic transmission for vehicles as described above, when the manual shift range is set to a driving range such as the D range, the accelerator pedal is released and the vehicle speed is substantially zero. Even when the vehicle is temporarily stopped, the gear transmission is set to the first gear, so that the vehicle can be started with excellent responsiveness to the depression of the accelerator pedal. However, when the vehicle is temporarily stopped, the gear transmission is set to the first gear. When the engine is set to the first gear, the output of the internal combustion engine is transmitted to the forward drive input member of the gear transmission through the hydraulic torque converter, which causes large engine vibrations and creep, which can cause damage to the vehicle. In order to completely stop the vehicle, the brake pedal must be pressed relatively hard to activate the vehicle running brake, and the drag of the hydraulic torque converter at this time causes the vehicle to stop when the vehicle is temporarily stopped. It is known that fuel economy deteriorates and the temperature of the hydraulic fluid in the hydraulic torque converter increases. In view of the above-mentioned problems, in order to bring the gear transmission into a neutral state or equivalent to a neutral state during operation when the vehicle is substantially stopped, the output member of the hydraulic torque converter and the friction engagement device of the gear transmission are combined. Releasing the so-called forward clutch that selectively connects the input member of the gear transmission with the input member for forward travel of the vehicle, or lowering the engagement pressure of the forward clutch to a level lower than when the forward gear is achieved, so that the forward clutch does not transmit torque. The patent application provides an automatic transmission for a vehicle equipped with a control device that is set to a value that causes slippage so that the output torque of the hydraulic torque converter is not transmitted to the forward travel input member of the gear transmission via the forward clutch. Showa 41-18128
(Japanese Patent Publication No. 1977-19962), Patent Application No. 117742 (Sho 56-21047), Patent Application No. 10444 (Sho 58-128552), Patent Application No. 75829 (Sho 57) No. (Japanese Patent Publication No. 1983)
-193953), Japanese Patent Application No. 115087 (1983)
6454) has already been proposed. Furthermore, as an improvement to these anti-creep controls, when the forward clutch is not transmitting torque as described above, it is possible to prevent the vehicle from starting backward movement when the vehicle is stopped on an uphill slope, etc. In order to avoid loss of ease of operation, the output shaft of the gear transmission is rotated in the backward direction of the vehicle by effectively utilizing a one-way clutch and a shift brake that the gear transmission is equipped with to achieve the gear position. The automatic transmission operation control method that produces the so-called hill hold control function that prevents the vehicle from moving backward against the driver's will when the vehicle is temporarily stopped under anti-creep control is the same as the present application. Applicant's Japanese Patent Application No. 176302 (1982)
No. 55456). This automatic transmission operation control method includes a hydraulic torque converter and a gear transmission that is switched between a plurality of gear stages by engaging and disengaging a plurality of frictional engagement devices, The frictional engagement device includes a forward clutch that selectively connects the output member of the hydrodynamic torque converter and the forward travel input member of the gear transmission, and a frictional engagement device that cooperates with the forward clutch by a rotation blocking action. A one-way clutch that achieves a certain gear, such as first gear, and a shift brake that cooperates with the one-way clutch when engaged to prevent the output shaft of the gear transmission from rotating in a direction in which the vehicle moves backward. Applicable to automatic transmissions for vehicles that include automatic transmissions, when the manual shift range is set to a forward travel range such as the D range, the vehicle is substantially stopped, the accelerator pedal is released, and the vehicle travel braking brake is applied. When the vehicle is braking, the engagement pressure of the forward clutch is set to a value that causes the forward clutch to slip, lower than when the forward gear is achieved, and the shift brake is engaged, and from this state the vehicle When the braking action of the travel braking brake is released, the engagement pressure of the forward clutch is increased to the value when the forward gear is achieved, and the shift brake is subsequently engaged, and the accelerator pedal is further depressed. The shift brake is released when the shift brake is pressed. According to this automatic transmission operation control method when a vehicle is temporarily stopped, when the manual shift range is set to a forward driving range such as the D range and the accelerator pedal is released and the vehicle is substantially stopped. When the brake for braking the vehicle is operating, the engagement pressure of the forward clutch is set to a value lower than the value when the forward gear is achieved, so that the output torque of the hydraulic torque converter is applied to the gear shift. The transmission to the input member for forward travel of the device is prevented, thereby reducing engine vibration and preventing the occurrence of creep. The synergistic action of the brake and the one-way clutch prevents the output shaft of the gear transmission from rotating in the backward direction of the vehicle, so that even if the brake for braking the vehicle is not reliably operated when the vehicle is stopped on an uphill slope, That is, even if the brake pedal is not strongly depressed or the parking brake is not tightened reliably, the vehicle is prevented from moving backward against the driver's will. Under the above-mentioned anti-creep control state, when the braking operation of the vehicle travel control brake is released, the shift brake remains engaged and the forward clutch is brought into an engaged state in which torque can be transmitted. As a result, the gear transmission achieves a gear higher than the first gear, the vehicle is prevented from continuing to reverse, and the next time the accelerator pedal is depressed, the shift brake is released. The gear transmission then attains the first gear, and the vehicle is started. Problems to be Solved by the Invention However, in the automatic transmission operation control method when a vehicle is temporarily stopped as described above, the shift brake is released only after the accelerator pedal is depressed, and the shift gear is shifted from the high speed gear to the first gear. Since the engine is downshifted into gears, a power-on downshift shock occurs when the vehicle starts, and the starting feeling becomes significantly worse. An object of the present invention is to provide an improved idle operation control method that solves the above-mentioned problems. Means for Solving the Problems According to the present invention, the present invention provides a hydraulic torque converter and a gear that can be switched between a plurality of gears by engaging and disengaging a plurality of frictional engagement devices. a transmission, wherein the plurality of frictional engagement devices include a hydraulically actuated forward clutch that selectively connects the output member of the hydraulic torque converter and the forward travel input member of the gear transmission; ,
a one-way clutch that cooperates with the forward clutch to achieve a certain gear stage by a rotation-preventing action, and when engaged, the output shaft of the gear transmission cooperates with the one-way clutch to rotate in the direction in which the vehicle moves backward; In a driving control method of an automatic transmission when the vehicle is temporarily stopped, the manual shift range is set to the forward travel range and the accelerator pedal is released and the vehicle travel brake is applied. When the shift brake is operating and the vehicle is substantially stopped, the hydraulic pressure of the forward clutch is set to a value lower than the value when the forward gear is achieved, and the shift brake is engaged to maintain this state. When the braking action of the brake for braking the vehicle is released, the hydraulic pressure of the forward clutch is increased to the value when the forward gear is achieved, and when the hydraulic pressure of the forward clutch reaches a predetermined value, the shift is performed. This is achieved by a method for controlling the operation of an automatic transmission when a vehicle is temporarily stopped, which is characterized in that the automatic transmission brake is released. Effects and Effects of the Invention According to the method for controlling the operation of an automatic transmission when a vehicle is temporarily stopped according to the present invention, when the manual shift range is set to a forward travel range such as the D range, the accelerator pedal is released and the vehicle is substantially stopped. When the vehicle is stopped and the brake for braking the vehicle is operating, the engagement pressure of the forward clutch is set to a value lower than when the forward gear is achieved, causing the forward clutch to slip. This prevents the output torque of the hydraulic torque converter from being transmitted to the forward drive input member of the gear transmission, thereby reducing engine vibration and preventing the occurrence of creep. Sometimes, when the shift brake is engaged, the output shaft of the gear transmission is prevented from rotating in the backward direction of the vehicle due to the cooperative action of the shift brake and the one-way clutch, and this prevents the vehicle from moving backward when stopped on an uphill slope. Sometimes, even if the vehicle travel brake is not operated reliably, that is, the brake pedal is not strongly depressed, or the parking brake is not reliably tightened, the vehicle may move backwards against the driver's will. blocked. Under the anti-creep control condition as described above,
When the braking action of the vehicle running control brake is released, the forward clutch is in an engaged state capable of transmitting torque, and the gear transmission temporarily achieves a gear higher than the first gear; Then, the shift brake is released, so that the gear transmission achieves the first gear. This release of the shift brake, that is, the downshift, is performed without the accelerator pedal being depressed, so this is done smoothly without a shock, and this allows the power-on downshift to occur when the vehicle is started. Shocks are avoided. When the forward clutch is engaged, a forward driving force is generated, so even if the shift brake is released at this time, the vehicle will not move significantly backward. Further, in this case, the forward clutch is engaged while the shift brake is engaged, that is, when a high speed gear is achieved, so that the engagement shock is small. In addition, in the above-mentioned control, the detection that the vehicle speed has substantially stopped and the accelerator pedal has been released depends on the vehicle speed and the throttle opening of the engine intake system, or the vehicle speed and the engine rotation speed. It may be done by EXAMPLES The present invention will now be described in detail by way of examples with reference to the accompanying drawings. FIG. 1 schematically shows the structure of an automatic transmission for a vehicle to which a method for controlling automatic transmission operation during vehicle temporary stop according to the present invention is applied. The automatic transmission 1 includes a three-element, one-stage, two-phase general hydraulic torque converter 2 with a direct coupling clutch, which has a pump impeller 3, a turbine impeller 4, a stator impeller 5, and a direct coupling clutch 6, and an auxiliary transmission device. Gear transmission 7 as
Pump impeller 3, which is an input member of hydraulic torque converter 3, is drivingly connected to output shaft 101 of internal combustion engine 100, and turbine impeller 4, which is an output member of hydraulic torque converter 2, is connected to a gear transmission. The output shaft 8 of the gear transmission 7 is drivingly connected to the drive wheels (not shown) of the vehicle via a differential gear. The gear transmission 7 has a sub-gear transmission 10 and a main gear transmission 11 in series with each other. The auxiliary gear transmission 10 includes a sun gear 12, 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 (F ₀ )1
6, an OD clutch (C ₀ ) 17 that selectively connects sun gear 12 and carrier 15, and sun gear 1.
OD brake (B ₀ ) 18 for selectively fixing the transmission case 2 to the transmission case;
A carrier 15 is drivingly connected to the input shaft 9 and can be shifted between two gears by selective engagement of an OD clutch 17 and an OD brake 18. The main gear transmission 11 includes a front sun gear 20 and a rear sun gear 21 connected to each other by an intermediate shaft 19, a front ring gear 22 provided concentrically with the front sun gear 20, and a rear ring provided concentrically with the rear sun gear 21. gear 23
, a front planetary pinion 24 located between the front sun gear 20 and the front ring gear 22 and meshed with them; and a rear planetary pinion 25 located between the rear sun gear 21 and the rear ring gear 23 and meshed with both. , a front carrier 26 rotatably supporting the front planetary pinion 24, and a rear planetary pinion 25.
A rear carrier 27 rotatably supported, and a front ring gear 22, which is an input member for forward travel of the main gear transmission 11, are selectively connected in a torque transmission relationship to the ring gear 13, which is an output member of the auxiliary gear transmission 10. forward clutch (C ₁ ) 28
, a direct clutch (C ₂ ) 29 that selectively connects the intermediate shaft 19 and the ring gear 13 in a torque transmission relationship, and a shift brake (B ₁ ) that selectively fixes the intermediate shaft 19 to the transmission case. ) 30, another shift brake (B ₂ ) 31 that selectively fixes the rear carrier 27 to the transmission case, and a one-way clutch (F ₁ ) 32 that locks the rear carrier 27 from rotating counterclockwise. Front carrier 2
6 and 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 predetermined combinations, thereby providing three forward speeds and one reverse speed. It is designed to be able to shift between a plurality of gears. The gear transmission 7 is constructed by the clutches and brakes of the auxiliary gear transmission 10 and the main gear transmission 11 being engaged and released according to the table shown below. A plurality of gears, including five forward gears including an overdrive gear and one reverse gear, are selectively achieved by the cooperative action of the main gear transmission 11 and the main gear transmission 11.

【table】

[Table] 2nd speed ○ ×
× × ○ ○ △ ×

Claims (1)

[Claims] 1 comprises a hydraulic torque converter and a gear transmission that is switched between a plurality of gears by engaging and disengaging a plurality of frictional engagement devices, wherein the plurality of frictional engagement devices are connected to the hydraulic torque converter. A hydraulically actuated forward clutch selectively connects the output member of the torque converter and the forward travel input member of the gear transmission, and cooperates with the forward clutch by a rotation blocking action to shift a certain gear position. a one-way clutch for achieving a vehicle temporary stop of an automatic transmission; and a shift brake that, when engaged, cooperates with the one-way clutch to prevent rotation of the output shaft of the gear transmission in a direction in which the vehicle is traveling in reverse. In the driving control method, when the manual shift range is set to the forward driving range, the accelerator pedal is released, and the vehicle travel braking brake is operating and the vehicle is substantially stopped. The hydraulic pressure of the forward clutch is set to a value lower than the value when the forward gear is achieved, and the shift brake is engaged, and when the braking operation of the vehicle travel braking brake is released from this state, the forward clutch is activated. An automatic transmission when a vehicle is temporarily stopped, characterized in that the hydraulic pressure of the clutch is increased to a value when a forward gear is achieved, and the shift brake is released when the hydraulic pressure of the forward clutch reaches a predetermined value. operation control method.