JPH0531714B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to a shift control device for an automatic transmission used in vehicles such as automobiles, and particularly for so-called part-time 4WD type automatic transmissions that can switch the drive state between four-wheel drive and two-wheel drive. This invention relates to a shift control device for automatic transmissions used in vehicles. [Prior Art] Automatic transmissions used in vehicles such as automobiles generally include a fluid-type torque converter and a gear-type transmission that switches between a plurality of gear stages, and change the engine output and vehicle speed. Accordingly, the gear position of the transmission device is automatically controlled to switch according to a predetermined shift control characteristic. [Problems to be Solved by the Invention] As vehicles such as automobiles, so-called part-time 4DW vehicles are known that can switch the drive state between four-wheel drive and two-wheel drive. In this type of vehicle, four-wheel drive generally requires greater driving force than two-wheel drive, and therefore four-wheel drive requires a greater number of intermediate gears than two-wheel drive. It is preferable that shift control is performed between a plurality of gear stages so that a large driving force can be obtained. In view of the above-mentioned demands, it is an object of the present invention to provide a speed change control device for a vehicle automatic transmission that performs speed change control. [Means for Solving the Problems] In order to achieve the above problems, the present application provides an automatic transmission for a part-time 4WD vehicle that can switch the drive state between four-wheel drive and two-wheel drive. In a speed change control device for selectively achieving the following, a first speed change pattern and a speed change pattern based on the first speed change pattern are used as a speed change pattern that determines the speed to be executed in accordance with the running state of the vehicle. means for setting a second shift pattern with a smaller number of gears; means for detecting whether or not the vehicle is set to a four-wheel drive state; and means for detecting whether or not the vehicle is set to a four-wheel drive state; The present invention proposes a speed change control device characterized by having a control means for selecting a speed change pattern and performing speed change control. In the above-mentioned speed change control device, the second speed change pattern is, as one example, a speed change pattern that excludes at least one intermediate speed among the speeds included in the first speed change pattern. That's fine. The transmission used to implement the shift control device of the automatic transmission for vehicles of the present invention includes a first transmission that switches between two gears, and a second gear that switches between at least two gears. transmission, and in the case of four-wheel drive, at least two N gears of the second transmission, each of which connects the first transmission between two gears. The gear shift control is performed between at least four gear stages, and when the two-wheel drive is performed, the second transmission (N-
1) switching the first transmission between two gears in each gear, and at least three of the at least four gears not including at least one intermediate gear; The gear change control may be carried out between the gears. When automatic shift control is performed using the second shift pattern, upshifting may be performed at a lower vehicle speed than when automatic shift control is performed using the first shift pattern. [Operations and Effects of the Invention] According to the shift control device of the present invention, in four-wheel drive mode, when high power performance is desired rather than a small number of shift shifts and a small number of shift shocks, an automatic system that automatically ensures this is achieved. Shift control is performed. [Example] The present invention will be described in detail below 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 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. The pump impeller 3, which is an input member of the hydraulic torque converter 2, is drivingly connected to the output shaft 101 of the internal combustion engine 100, and the pump impeller 3, which is an input member of the hydraulic torque converter 2, is drive-coupled to the output shaft 101 of the internal combustion engine 100. The wheel 4 is drivingly connected to an input shaft 9 of a gear transmission 7, and an output shaft 8 of the gear transmission 7 is drivingly connected to 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 is an overdriver gear transmission in a conventional 4th speed automatic transmission, and includes a sun gear 12, a ring gear 13 provided concentrically with the sun gear 12, and a ring gear 13 provided concentrically with the sun gear 12. A planetary pinion 14 that is located between the gear 13 and meshes with both, a carrier 15 that rotatably supports the planetary pinion 14, and a sun gear 1.
2, a one-way clutch (F ₀ ) 16 that prevents the carrier 15 from rotating to the left, an OD clutch (C ₀ ) 17 that selectively connects the sun gear 12 and the carrier 15, and the sun gear 12 selected for the transmission case. The carrier ₁₅ is drivingly connected to the input shaft 9, and the two gears can be changed by selectively engaging the OD clutch 17 and the OD brake 18. It is now possible to switch between 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 running of the main gear transmission 11, are selectively connected to the ring gear 13, which is an output member of the auxiliary gear transmission 10, in a torque transmission relationship. 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 a predetermined combination, thereby providing three forward speeds and one reverse speed. It is designed so that it can be changed between the following 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. Through the cooperative action of the main gear transmission 11 and the main gear transmission 11, a plurality of gears, five forward gears including an overdrive gear and one reverse gear, are selectively achieved.

[Table] Nji
2nd speed ○ × × × ○ ○ △ ×

[Table] 2nd speed ○ × × × ○ ○ △ ×

Claims (1)

[Scope of Claims] 1. A shift control device for selectively achieving a plurality of gears in an automatic transmission of a part-time 4WD vehicle that can switch the drive state between four-wheel drive and two-wheel drive. and setting a first shift pattern and a second shift pattern having a smaller number of gears than the first shift pattern as shift patterns that define the gears to be executed in accordance with the running state of the vehicle. means for detecting whether or not the vehicle is set in a four-wheel drive state; and control means for selecting the first shift pattern and performing shift control when the vehicle is set in a four-wheel drive state. A speed change control device comprising: 2. In the speed change control device according to claim 1, the second speed change pattern is a speed change pattern that excludes at least one intermediate speed among the speeds included in the first speed change pattern. A speed change control device characterized by: