JPS58170959A - Reduction gear ratio control method of automatic stepless speed change gear for car - Google Patents

Abstract

PURPOSE:To smoothly restart a car even if the car is suddenly stopped during low-speed running by starting down shift of a reduction gear ratio control mechanism in an oil pressure control circuit when a throttle opening is 0. CONSTITUTION:When a throttle opening theta is 0, down shift is immediately started and a car velocity is detected. Corresponding to the car velocity, the down shift amount of a V-belt stepless speed change gear is increased or decreased. As the lower the car velocity is, the shorter is the time required for stopping a car after stepping on a brake, the lower the car velocity is, the more the speed change gear is shifted to the down side. In that case, when the brake is stepped, at a lower car velocity, down shift can be completed at smaller shift width, in a short time. If an accelerating pedal is released during high speed running, gripping of an engine brake is lessened so as to improve safety and driving feeling.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a reduction ratio control method for a continuously variable automatic transmission for a vehicle using a V-pel 1 to adult stage transmission.

An input pulley and an output pulley are provided on the input shaft and output shaft, respectively, and the effective diameter is increased or decreased by a hydraulic servo, and a V is transmitted between the manual pulley and the output pulley.
Continuously variable automatic transmissions for vehicles using a V-belt type continuously variable transmission, which consists of a belt, are used in combination with a fluid coupling such as a 1 to LU converter or fluid coupling, and a forward/reverse switching MS to provide continuously variable automatic transmission of vehicles such as automobiles. It is suitable for use as a machine. However, in this type of automatic transmission for vehicles,
When you brake suddenly while driving and come to a stop, the V-belt continuously variable transmission may stop without downshifting to the maximum reduction ratio. Since it is difficult to change, the next time you start, a sudden downshift occurs and the V-belt slips, making it impossible to restart smoothly. Therefore, in order to get a smooth restart, it is desirable that the V-belt continuously variable transmission perform a quick downshift when sudden braking is applied, but it is not possible to shorten the downshift time beyond a certain point. Technically difficult.

An object of the present invention is to provide a reduction ratio control method for a continuously variable automatic transmission for a vehicle that can reliably downshift to the maximum reduction ratio even during such sudden braking and can provide smooth restart.

The reduction ratio control method for a continuously variable automatic transmission for a vehicle according to the present invention includes an input pulley and an output pulley that are provided on an input shaft and an output shaft, respectively, and whose effective diameters are increased or decreased by a hydraulic servo;
This is a control device for a continuously variable automatic transmission for vehicles that uses a V-bell mill type continuously variable transmission consisting of a V-belt that transmits power between the human power booster and the output booster. an electric control circuit comprising means for detecting vehicle running conditions such as torque and brake operation; and logic means for outputting an output in accordance with input from the detecting means; Controls the supply and discharge of hydraulic oil to the hydraulic servo of the output pulley,
In the control device for a continuously variable automatic transmission for a vehicle, the controller includes a hydraulic control circuit including a reduction ratio control t [1 mechanism that changes the reduction ratio of the V-belt continuously variable transmission according to vehicle running conditions, wherein the electric control In the circuit, when the throttle opening θ is 0,
The reduction ratio control mechanism in the hydraulic control circuit is outputted to start a downshift, and the reduction ratio control mechanism causes the V-belt continuously variable transmission to immediately start a downshift after the accelerator pedal is released, thereby increasing the vehicle speed. The configuration is to downshift to the corresponding set reduction ratio.

Next, the present invention will be explained based on one embodiment shown in the drawings.

FIG. 1 shows a continuously variable automatic transmission for a vehicle.

100 is a fluid coupling room 110 in which a fastening surface 100A with the engine is open and fluid controllers such as fluid couplings and torque converters are stored; and 2 l b in which the side opposite to the engine is open and a Dino differential gear is stored. There is also a differential room 120 that supports one output shaft of the differential gear, and an idler gear room 1 that similarly opens on the side opposite to the engine and houses the idler gear and supports one of the shafts of the idler gear.
A torque converter case 200 has a transmission room 21'o1 which is open on the engine side and houses a belt-type continuously variable transmission. It consists of a differential room 220 that supports one output shaft, and an idler gear room 230 that covers the side opposite to the engine side of the idler gear room 130 of the torque converter case,
Said [-Side 1 opposite to the engine of the lux converter case
This is a transmission case fastened to 00B at ports 1 to 1, and forms an outer shell (case) of a vehicle automatic transmission together with the torque converter case and an intermediate case to be described later. 300 is a center case that pivotally supports the transmission shaft between the fluid coupling and the transmission, and in this embodiment, the center case is housed in the transmission case and fastened with bolts to the side 100F3 of the torque converter case opposite to the engine. It has a case configuration. The automatic transmission in this embodiment C is 1-roux converter case 10.
A known fluid coupling 400 and a transmission case 2 arranged in the transmission case 2 and connected to the output shaft of the engine.
It consists of a transmission installed in 00. The transmission has a hollow shaft center, and the hollow portion 511
An input shaft 510, which serves as a supply and discharge path for hydraulic oil and lubricating oil for a hydraulic servo, is disposed so as to have the same axis as the fluid coupling 400, and the shaft center is hollow, and the hollow portion 511
The output shaft 5 is used as an oil supply/drainage path for hydraulic oil of the hydraulic servo.
50 is a V-belt continuously variable transmission 5001 arranged parallel to the input shaft 510; the input shaft 5 of the V-belt continuously variable transmission;
10 and a planetary gear transmission mechanism 600 disposed between the fluid coupling output shaft and the V-belt continuously variable transmission 5.
A differential 700 in which an output shaft 710 arranged in parallel with the input shaft 510 and output shaft 550 of the 00 is connected to an axle, and the input large gear 720 of the differential 700 and the V-belt type The output shaft 550 of the step-change transmission 500 is inserted between the output gear 590 of a V-belt type continuously variable transmission provided at the end of the engine,
A j-hydrauler gear shaft 810 is provided parallel to the output shaft 550 with one end being pivotally supported by the torque converter case and the other end being pivotally supported by the renter case 300, which is an inner case. The idler gear 800 includes an input gear 820 and an output gear 830.

V-belt continuously variable transmission 500 and planetary gear transmission mechanism 6
00, predetermined controls such as reduction ratio, forward movement, and reverse movement are performed by a hydraulic control device according to vehicle running conditions such as vehicle speed and throttle opening.

Reference numeral 104 denotes an oil pump which is fastened to the wall of the center case (the fluid coupling where the engine is mounted) and houses an oil pump 106 driven by a hollow shaft 410 that is integrated with the fluid coupling 400. It's a cover.

The output shaft 420 of the fluid coupling 400 is rotatably supported by a sleeve 310 fitted in the center of the hinter case 300 via a metal bearing 320, and the hub 44 of the lock-up clutch 430 is attached to the engine side end.
0 and the hub 4 of the fluid coupling turbine 450
60 are spline-fitted, and the other end has a step-like enlarged diameter, and the large diameter portion serves as an input shaft 601 of the planetary gear transmission mechanism 600, and is supported by the intermediate support wall 3 via a bearing 330. The output shaft 420 of the fluid coupling and the input shaft 601 of the planetary gear transmission mechanism are hollow (formed in this way), and the hollow part is provided with an oil passage 421 and fitted with a plug 420, and furthermore, the V-belt type continuously variable transmission Machine input shaft 5
The engine side end of the sleeve 422, which is attached to the sleeve 10, is rotatably fitted.

The planetary gear transmission mechanism 600 is connected to an input shaft 601 that is integrated with the output shaft 420 of the fluid coupling 400, and is also connected to a fixed flange of a V-belt type continuously variable transmission, which will be described later, via a multi-plate clutch 630. carrier 6
20, center case 30 via multi-plate brake 650
The ring gear 660 is engaged with the sun gear 660, and the sun gear 660 is installed on the outer periphery of the output shaft 610 of the planetary gear transmission mechanism, which is integrally formed with the input shaft 510 of the V-belt continuously variable transmission.
1 It was pivotally supported by the carrier 620 and meshed with the sun gear 670 and ring gear 66! Lane clearance gear 640, formed on the wall of the center case 300, and the multi-disc brake 6
50, and a hydraulic servo 69 formed on the stationary wall and operating the multi-disc clutch 630.

The V-belt continuously variable transmission 500 has a planetary gear transmission mechanism 60.
Fixed 7 langes 520A formed integrally with the input shaft 510 integrated with the output shaft 610 of 0, and the hydraulic servo 530
an input horn pulley 520 consisting of a movable flange 52B driven in the direction of the fixed flange 52A, a fixed flange 560Δ integrally formed with the output shaft 5j) 0 of the Pel 1 to adult stage transmission, and the oil y1 servo. 57, an output pulley 560 consisting of a movable flange 560B driven in the fixed 7 lange 560 direction, and an input pulley 5
V-belt 58 transmitting power between 20 and output pulley 560
Consists of 0.

The input shaft 510 of the V-belt type continuously variable transmission has an engine side end 5108, which serves as an output shaft 610 of the planetary gear transmission mechanism, supported by the input shaft 601 of the planetary gear transmission mechanism via a bearing 340. , is supported by the center case 300 via the input shaft 601 and the bearing 330, and the other end 510B is supported by the side wall 250 of the transmission case opposite to the engine via the bearing 350, and furthermore, its tip surface 5100 is supported by the side wall 250 of the transmission case via the bearing 350. A needle (roller) bearing 2 is attached to a lid 260 fastened to 250.
It is brought into contact via 70.

A hollow portion 511 formed at the axial center of the human power shaft 510 of the V-belt type continuously variable transmission has the sleeve 42 attached to the side of the engine.
2 is fitted, and the engine side part 511A transfers the hydraulic pressure supplied from the oil passage 421 through the center case 300 and the oil passage 301 to the hydraulic servo 690 through an oil passage 513 formed at the base of the fixed flange 520A. The opposite side portion 511B is a lid 26 whose tip end is designed to close a hole 250Δ formed in a portion corresponding to the input shaft 510 of the side wall 250 of the transmission case.
0, the transmission case 200 is formed in the transmission case 200 including the lid 260, and the entire space is connected to the oil passage 514 communicating with the hydraulic control device.
Pressure oil supplied through the protrusion 261 of the hydraulic servo 5
It acts as an oil passage for supplying oil to 30.

The output gear 590 is integrally formed with a hollow support shaft 591, and the support shaft 591 is supported by the side wall of the torque converter case via a roller bearing 592 with the engine side @I 591A forming one support point and the other. The end 591B is zt? through the roller bearing 593. Intercase 30
0, and the engine side side 590Δ of the output gear 590 is a needle bearing 5 that forms an intermediate fulcrum.
94, and the opposite side surface 590B of the output gear is brought into contact with the side surface of the center case 300 via a needle bearing 595, and the transmission of the support shaft 591 is An inner spline 596 is formed.

The output shaft 550 of the V-belt type continuously variable transmission has an outer spline 550A formed at the end near the engine that fits into the inner spline 596 formed on the support shaft 591 of the output gear, and the output gear supporting shaft 591
is supported by the center case 300 via the other end 550
B is attached to the side wall 2 of the transmission case opposite to the engine via a ball bearing 920 forming the other supporting point 1.
It is supported by 50.

A sensing valve body 552 is fitted in the middle part of an oil passage 551 formed at the axial center of the output shaft 550 of this V-belt type continuously variable transmission. Hydraulic pressure supplied from an oil passage 140 formed in the engine case and communicating with a hydraulic control device is used as an oil passage to guide the hydraulic servo 570 to the side 552 [34 of the Harushibo eye 552 opposite to the engine].
The tip of the transmission case is fitted into the pipe-like protrusion 554 of the swallow 553 formed in the hole 250B formed at the corresponding part of the output 550 of the side q 250 of the transmission case. This is an oil passage 3 in which the oil pressure is adjusted by a reduction ratio detection valve 50 formed in a lid 55) 3 fastened to the case and which detects the displacement position of the movable flange 560B from a hydraulic control device. The reduction ratio detection valve 50c and the engagement pin 51Δ, which are cut out at the right end of the detection rod 51 in the illustration, are engaged with a step 561 formed on the inner circumference of the movable flange 560B, and as the movable 7 langes 560B are displaced. The oil pressure of the oil passage 3 is adjusted by displacement of the spool.

FIG. 2 shows a hydraulic control device for controlling the continuously variable automatic transmission for a vehicle shown in FIG. 21 is an oil reservoir; 20 is an oil pump that is driven by the engine and discharges the hydraulic oil sucked from the oil reservoir 21 into the oil passage 1; 30 is an oil pump that adjusts the oil pressure of the oil passage 1 according to the input oil pressure, and adjusts the line pressure. pressure regulating valve, 40
The line H supplied from the oil passage 1 is adjusted according to the opening degree of the first slot (L), the line H supplied from the oil passage 1 is outputted as pressure from the first slot (-), and the orifice 22 is output from the oil passage 3. When the throttle opening is equal to or greater than the set value 01, the reduction ratio pressure output from the reduction ratio detection valve 50 supplied through the oil passage 3a is
A throttle valve 50 outputs the oil pressure as a throttle valve, and the oil pressure in the oil passage 3 communicating with the oil passage 1 via the orifice 23 is set to V.
Movable flange 5 of output pulley of belt type continuously variable transmission
the reduction ratio detection valve that regulates pressure according to the amount of displacement of 60B;
0 communicates with the oil passage 1 via an orifice 24, and regulates the oil pressure of the oil passage 4 through which excess oil from the pressure regulating valve 30 is discharged, and uses the excess oil passage as lubricating oil from the oil passage 5 to continuously variable automatic transmission. 7o is a manual valve that is operated by a shift lever installed at the operating level and distributes the line pressure of oil passage 1 according to the operation of the driver; The hydraulic pressure of the oil passage 4 is connected to the fluid coupling 40.
8o is a lock-up control mechanism that controls engagement and release of the lock-up clutch 430;
Input the hydraulic pressure of a from the oil path 1b to the hydraulic servo 5 of the pulley.
V bell which outputs to 30] Reduction ratio (torque ratio) control mechanism of continuously variable transmission llA300, 1o is oil passage 1 that communicates with oil passage 1 when manual valve 65 is shifted to 1-range.
C, a low modulator valve that regulates the line pressure and supplies it to the oil passage 2 as a low modulator valve; 12, a relief valve provided in the oil cooler oil passage 11; 25;
is a relief valve provided in the oil passage 1, 26 is a check pressure flow control valve provided in the line pressure supply oil passage 6 to the hydraulic servo 680 of the multi-disc brake of the planetary gear transmission mechanism 300, and 27 is a planetary gear The check valve A is a flow rate control valve provided in the line pressure supply oil passage 7 to the hydraulic lever 690 of the multi-disc clutch in the transmission mechanism 300.

The hydraulic pressure adjustment device is composed of the pressure regulating valve 30, the throttle valve 40, and the reduction ratio detection valve 50. The reduction ratio detection valve 50 includes a detection rod 51 having an engagement pin 51A fixed to one end that engages with the movable 7 langes 560B of the output pulley of the belt type continuously variable transmission, and a detection rod 51 having a spring 52 installed in front of the other end. ,
A spool 54 having lands 54A and 54B arranged in series through the detection rod 51 and a spring 53, a boat 55 communicating with the oil passage 3, a drain boat 56, and a boat 55 and lands 54A and 54 provided on the spool 55. 3
The hydraulic pressure Pi as shown in FIG. 3 is generated in the oil passage 3 according to the displacement of the movable flange 56013.

The throttle valve 40 is a throttle valve 1 that is displaced by contacting a throttle cam linked to an accelerator pedal at the driver's seat.
The throttle plunger 42 includes a spool 44 connected in series with the throttle plungers 4 and 42 via a spring 43, and the plunger 42 and spool 44 are displaced to the left in the figure as the throttle opening increases to 0. plunge p4
2 is the rotation angle of the screwdriver cam 41 and the land 42a.
Hydraulic throttle opening degree O of oil passage 2 fed back to
When is equal to or higher than the set value 01 (θ・θ1), connect the oil passage 3 and the oil passage 3a and install a second slot equal to the reduction ratio pressure in the oil passage 3a. o<01, the hydraulic pressure in the oil passage 3a is discharged from the drain boat 40a via the oil passage 423 provided in the plunger 42, and the oil pressure in the oil passage 3a is set to the second slot pressure Pj as shown in FIG. to occur.

The movement of the throttle cam is transmitted to the spool 44 via the spring 43, and the throttle cam is connected to the opening of the throttle 1 to the orifice 45.
The throttle pressure pth generated in the oil passage 2 is adjusted by changing the communication area between the oil passage 1 and the oil passage 2, as shown in FIGS. 5 and 6. Press.

The pressure regulating valve 30 has a spring 31 installed in front on one side (left side in the drawing), a spool 32 equipped with lands 32A, 32B, and 32C, and a spool 32 installed in front in series with the spool 32, and a small diameter land 33A. A first regicolator plunger 33 having a large-diameter land 33B, and a second regicolator plunger 34 arranged in series in contact with the plunger 33.
A boat 34a and an orifice 3 are connected to the oil passage 1.
Pormill 3 to which line pressure is fed back via 5
4b drain boat 34C1 boat 34d for discharging surplus oil into oil passage 4, drain boat 34e for discharging leaked oil from between the land and valve wall, input port 34 [, It consists of an input port 34Q to which the first throttle pressure is input from the oil passage 2, a second throttle I from the oil passage 3a, and an input port 34h to which the throttle pressure is input.

When the manual valve 70 is set to the 1-range, the low modulator valve 10 has a 7th position that does not depend on the throttle opening.
10 - Outputs the modicolator juice plOW as shown in the figure. Here, neither the low modulator valve nor the strike 1 torque valve has an exhaust pressure oil passage for pressure regulation, and the pressure is adjusted by utilizing the fact that the throttle VLPth is constantly exhausted from the reduction ratio control mechanism 80. Moreover, these two valves are arranged in parallel.

Therefore, in the lunge, the larger hydraulic pressure of Plow and pth is generated in the oil passage 2 as shown in FIG.

Therefore, as shown in FIG. 9, the line pressure "1" that is applied to the low throttle opening of the range increases compared to the case of the D range.

This pressure regulating valve 30 is configured to control the reduction ratio pressure inputted from the port 34f and applied to the second plunger 34, the first throttle pressure inputted from the port 34g and applied to the land 33B of the first plunger 33, and the first throttle pressure inputted from the port 34h and applied to the land 33B of the first plunger 33. 2nd slot 1~ applied to land 33A of 1 plunger 33
The lands 3 of the spool include the balls 1 to 34b which are connected to the oil passage 1 via the oil pressure spring 31 and the orifice 35.
The spool 42 is displaced by the line pressure fed back to the port 34a, which is connected to the oil passage 1, and the oil passage 4.
Port 34d and drain 1-34c connecting to
The line pressure P shown in FIGS. 9, 10, and 11 is adjusted by adjusting the area of the line 1 to increase or decrease the leakage amount of pressure oil in the oil passage 1.
give rise to L.

In the range, it is necessary to downshift to obtain strong engine braking. ■For Pell 1 to Valorous gear transmissions, when downshifting, the input pulley hydraulic servo 530
By connecting the oil passage to the exhaust pressure oil passage, the oil in the servo oil chamber is drained and a downshift is realized. but,
In order to obtain strong engine braking, the primary sheave must be rotated at a high rotation speed, but the oil pressure generated by the centrifugal force generated by this rotation may prevent waste oil from being generated. Therefore, when a quick downshift is required, it is necessary to apply a higher hydraulic pressure to the hydraulic servo 570 of the output pulley than usual, and this is particularly important when the throttle opening is low. For this reason, in the Nishi range, the low modulator valve adjusts the throttle I'f when the throttle opening θ is small.
r) The line pressure P[-(line pressure=hydraulic servo supply J, E of the output pulley) is increased while avoiding an increase in th.

The manual valve 65 is moved by a shift lever installed in the driver's seat, and is moved to the following positions: P <Park), R (Reverse>, Courtral to N), D (Drive), and L ([]-). It has a spool 66 to be set, and when set in each shift device, connects oil passage 1 or oil passage 2 with oil passage 1C oil passage and oil passage 6 oil passage 1 as shown in Table 2.

Table I P RN D L Oilway 7 × × × △ △ Oilway 6 × ○ ××× Oilway 1C--△ △ ○ In a3 in Table I, ○ indicates the connection with oilway 1, △ indicates which oilway 2 Connection, - indicates blockage of oil passage, and × indicates discharge pressure. As shown in Table I, in the R range, the line 1f is supplied to the brake 680 of the 11 gear transmission mechanism, and in the D and L ranges, the throttle pressure (or low modulator pressure) of the oil passage 2 is supplied to the clutch 690. The vehicle is switched between forward and reverse motion.

The second pressure regulating valve 60 has a spool 62 with a spring 61 on its back and lands 62Δ, 62B, and 62C. Displaced by oil passage 4, oil passage 5, and drain l-60A
The oil pressure in the oil passage 4 is regulated by changing the flow resistance of the oil passage 4, and lubricating oil is supplied from the oil passage 5 to the parts requiring lubrication, and excess hydraulic oil is drained from the drain 1-60A.

The reduction ratio control mechanism 80 includes a reduction ratio control valve 81, orinois 82 and 83, an electromagnetic solenoid valve 84 for upshift 1,
and downshift] to an electromagnetic solenoid valve 85.

The reduction ratio control valve 81G has a first land 812A, a second land 812B, and a third land 812C, and a spool 812 with a spring 811 mounted on the back of one land 812C, through orifices 82 and 83, respectively. side end oil chambers 815 and 816 at both ends to which thrower pressure or low modulator low is supplied from oil passage 2, intermediate oil chamber 810 between land 812B and land 812C, oil v815 and oil chamber 810. an input port 817 that communicates with the oil passage 1 to which line pressure is supplied and whose opening area increases or decreases according to the movement of the spool 812; A pressure regulating oil chamber 819 and a spool 812 are provided with an output boat 818 that communicates with the hydraulic servo 530 via an oil path 1b.
The drain boat 8 drains the pressure from the oil chamber 819 according to the movement of the drain boat 8.
14, and a drain boat 813 that evacuates the oil chamber 810 and the oil chamber 815 according to the movement of the spool 812. The upshift electromagnetic solenoid valve 84 and the town shift electromagnetic solenoid valve 85 are respectively attached to an oil chamber 815 and an oil chamber 816 of the reduction ratio control valve 81, and both are operated by the output of an electric control circuit to be described later. The oil chamber 815, the oil chamber 810, and the oil chamber 816 are evacuated.

The lock-up control mechanism 70 includes a lock-up control valve 71
, an orifice 77, and an electromagnetic solenoid valve 76 that controls the oil pressure of the oil passage 4a that communicates with the oil passage 4 via the orifice 77. [The J pull-up control valve 71 is
A spool 73 with a spring 72 installed on one side (right side in the drawing) and lands 73Δ, 73B, and 73C of the same diameter.
and a sleeve 75 which is provided in series with the spool 73 and has a spring 14 loaded on the other side (left side in the figure) and has a larger diameter than the land of the spool 73.
The oil HP4 in the oil passage 4 applied to the land 73C and the spring load Fs1 of the spring 72 are applied to the land 73C via the input port door 1A connected to Solenoid pressure Ps
Or oil pressure P in the oil passage 8 on the release side of the lock-up clutch 430 applied to the land 73A via the boat 41B.
8 and the spring load Fs2 by the spring 74, the spool 73 is displaced, and the oil passage 4 and the release oil passage 8 or the engagement oil passage 9 of the lock-up clutch 430 are displaced.
Control contact with. Solenoid valve 7G is energized and O
When the state is N, the hydraulic pressure in the oil passage 4a is discharged, the spool 73 is fixed to the left in the figure, the oil passage 4 and the oil passage 9 are in communication, and the hydraulic oil is transferred from the oil passage 9 to the lock-up clutch 430. →
The oil flows in the order of oil path 8→drain port 71C, and lock-up clutch 430 is in an engaged state. solenoid valve 76
is de-energized and the valve port is closed (OFF>), the oil pressure in the oil passage 4a is maintained, the spool 73 is fixed to the right in the figure, the oil passage 4 is in communication with the oil passage 8, and the hydraulic oil flows through the oil passage. The oil flows in the order of 8→lockup clutch 430→oil passage 9→connection oil passage 10 to the oil cooler, and lockup clutch 430 is released.

FIG. 12 shows the electromagnetic solenoid valve 7 of the pull-up clutch control mechanism 70 in the hydraulic control system shown in FIG.
6. The configuration of an electric control circuit 9o that controls the upshift electromagnetic solenoid valve 84 and the downshift electromagnetic solenoid valve 85 of the reduction ratio control mechanism 80 is shown.

91 is a shift lever switch that detects whether the shift cover is shifted to P, RIN, or L; 92;
is a rotation speed sensor that detects the rotation speed of input pulley A,
93 is a vehicle speed sensor, 94 is a throttle 1 sensor that detects the throttle opening of the engine, 95 is a brake switch that turns ON when the brake is applied, and 96 is a speed detector that converts the output of the rotation speed sensor 92 into voltage. A processing circuit 97 is a vehicle speed detection circuit that converts the output of the sensor 93 into a voltage, 98 is a throttle distance detection processing circuit that converts the output of the throttle sensor 94 into voltage, and 907 to 911 are seven input interfaces of each sensor. Chair, 912 is central processing center T9
device (Cf31]), 913 is an electromagnetic solenoid valve 76.
Read-on memory (ROM), 91, which stores programs and data necessary for controlling the 84.85.
4 is a random access memory (RAM) 915 that temporarily stores input data and parameters necessary for control;
is a clock, 916 is an output interface, 917 is a solenoid output driver, and output interface 9
16 is converted into the operating output of the downshift electromagnetic solenoid valve 85, the upshift electromagnetic solenoid valve 84, and the shift control solenoid 74. Input interfaces 908 to 911, CPU 912, ROM 91
3. A data bus 918 and an address bus 919 communicate with the RAM 914 and the output interface 916.

Next, the operation of the reduction ratio control mechanism 80 controlled by the electric control circuit 9o is illustrated in FIGS. 13 to 24.

During normal driving, the continuously variable automatic transmission for vehicles controls the reduction ratio (torque ratio) of the V-belt type continuously variable transmission using an electric control circuit 90 to achieve the best fuel efficiency at each throttle opening θ. So-called best fuel efficiency control is performed in which the pulley rotation speed N is determined.

The control of the reduction ratio control mechanism 80 is performed by controlling the reduction ratio control mechanism 80 to increase or decrease the speed ratio between the input and output pulleys by comparing the rotation speed N of the manual pulley with the best fuel efficiency and the actual input boolean rotation speed. This is done by the action of two electromagnetic solenoid valves 84 and 85, and the actual input pulley rotation speed is made to match the input pulley rotation speed for the best fuel efficiency. Sunawa 1
5. The best fuel consumption fluid coupling output line can be obtained from the fluid coupling output shaft equal fuel consumption rate curve (Figure 13) and the fluid coupling output equal horsepower curve (Figure 14) (Figure 15) , This best fuel efficiency Nord coupling combined output line and the engine + Nord coupling combined output performance (16th
By combining the values shown in Fig. 17), the best fuel efficiency fluid coupling output rotation speed (Fig. 17) at each throttle opening degree can be determined. The best fuel efficiency control can be achieved by controlling the gear ratio to achieve the best fuel efficiency fluid coupling output rotation speed for each throttle opening.

Conventionally, this optimum fuel efficiency control was performed even when the door was fully closed. However, when I suddenly applied the brakes,
Because the downshift cannot catch up, even if the vehicle stops, downshift 1~ may not be completed.
Immediately after that, when I stepped on the accelerator to start, there was a sudden downshift and the belt could not smoothly re-send C. To solve this problem, you can perform a quick downshift, but the time required to move the pulley from a certain reduction ratio position to the maximum reduction position during a town shift is approximately 7'.
It is technically difficult to make it extremely short.

However, if the best fuel efficiency limit is applied as described above, the downshift will not start immediately even when the brake is applied, and the drive sheave rotation speed will be such that the best fuel economy is achieved when the throttle is fully open. If it is higher than the rotation speed, the engine will upsit. Then, a downshift signal is issued only when the electric control circuit detects that the actual drive sheave rotation speed is lower than the drive sheave rotation speed that provides the best fuel efficiency as the medium speed decreases. Therefore, by starting the downshift earlier, even if the brakes are applied suddenly, it is possible to downshift more before stopping. Therefore, one possible method is to have the electric control circuit issue a town shift signal immediately when the throttle opening is fully opened, and cause the oil F1 control circuit to start downshifting. However, with this method, for example, when the throttle is fully opened at high speed, strong engine braking is applied, which is dangerous and undesirable in terms of driving feeling. Also, while driving at high speed, even if you release the accelerator and drive with the throttle opening θ-0, the vehicle will often coast, and even if you apply the brakes,
Since there is a time of 11 minutes until the vehicle stops, the downshift of the V-belt type continuously variable transmission can be completed with plenty of time, and a downshift that fast is not necessary.

Therefore, as a reduction ratio control method for a vehicle automatic transmission according to the present invention, a downshift is started immediately when the throttle opening is θ-0, the vehicle speed is detected, and the V-belt continuously variable transmission is controlled according to the vehicle speed. Increase or decrease the amount of downshift. In other words, the time from when the brake is pressed to when the vehicle stops is shorter as the vehicle speed is lower, so the lower the vehicle speed is, the more the vehicle is shifted to the down side. In this way, when the brake is depressed, the lower the vehicle speed, the smaller the shift width, which means that the downshift can be completed in a shorter time.

Furthermore, when the accelerator is released at high speed, the amount of engine braking applied can be reduced, improving safety and driving feeling.

FIG. 19 shows a block diagram of the control circuit of the belt-type continuously variable transmission. Input the shift position of the shift lever, the rotation speed of the hexagonal pulley N, the city speed■, the throttle opening θ, and the brake signal, and check whether the electromagnetic solenoid for upshift is for downshift?
The transmission gear ratio is controlled by turning the 1m solenoid ON or OFF.

After reading 921 the throttle opening 1e using the throttle sensor 9.04, the input pulley rotation speed sensor 9
2 and vehicle speed sensor 93 to read the input pulley rotation speed and vehicle speed 922, and then read the input pulley rotation speed and vehicle speed using brake switch 95.
The brake signal is read 923 using the shift lever switch, and the shift position is read 924 using the shift lever switch.

After loading these information shift lever switch F-9
01, the shift lever (Ht is determined 925 and P
, N processing subroutine 930, L, D processing subroutine 940, or N processing subroutine 960.

20 to 22 show flowcharts of the control circuit shown in FIG. 19.

b) If the shift lever is in the P or N position, the 20th
By the P position and N position processing subroutine 930 shown in the figure, both the upshift electromagnetic solenoid valve 84 and the downshift electromagnetic solenoid valve 85 are turned OFF FL,
(931) Store the P or N state in the RAM 914. (932) This brings the input pulley 520 into a neutral state.

0) When the shift lever is set to L position or D position.

According to the reduction ratio control method for a vehicle automatic transmission of the present invention, L
The upshift electromagnetic solenoid valve 84 and the downshift electromagnetic solenoid valve 85 are controlled according to the subroutine of the position and N position processing 940 as shown in the flowchart shown in FIG.

The throttle is not fully open and the shift lever is in D or 1-
If the position is correct, the best fuel efficiency control is performed. In this case, the 17th
The best fuel economy control line shown in the figure is stored in the form of a table in the ROM 913, and the input pulley rotation speed corresponding to the throttle opening is drawn from the table, and the input pulley rotation speed is used as the input pulley control rotation speed. Take control. That is, if the input pulley rotation speed N is less than the control rotation speed NO by 4J, the upshift 1~ electromagnetic solenoid valve 84 is turned on, and if it is smaller than the control rotation speed, the downshift electromagnetic solenoid valve 85 is turned on and the control is performed. If the rotation speed is equal, turn off both solenoid valves.

First, a determination 941 is made as to whether the throttle opening is O or not. θ
-0, it is determined 942 whether the current vehicle speed V is greater than the set vehicle speed vO, and if V<VO, the input boolean control rotation speed is set to NC=k(VO-V)+R. (
943) When L/, v≧vO, set NC=R (
944). Here, k is a constant preset according to the vehicle, and R is a preset input pulley rotation speed.

Next, compare the current input pulley rotation speed N with the input pulley control rotation speed NC (945). If L, N>NC, turn on the upshift electromagnetic solenoid 84 (946), and turn down if N<NC. Shift electromagnetic solenoid 85
is turned ON (948), and when N=Nc, both solenoid valves 84 and 85 are turned OFF (947). When it is e-0 in determination 941 as to whether the shift lever degree θ is O or not, determination 964 is made as to whether the shift lever setting position is lunge or D range, and when it is in D range, the D range table in ROM 913 is performed. In order to achieve the best fuel efficiency, the input boolean control rotation speed NO corresponding to the throttle opening θ is set (965), and when in the L range, the ROM 91 is set.
Input the data from the L range table in 3 and set the input pulley control rotation speed NC corresponding to the throttle opening θ (9
136), and in either case, the current input pulley rotation speed N
The process proceeds to a comparison 944 between the input pulley control rotation speed Nc and the input pulley control rotation speed Nc.

The control method is the same when the shift lever is set to the release position, but the input boolean control rotation speed Nc relative to the throttle opening θ is generally lower than that in the case of best fuel economy control II (shift lever D position). For example, set it to the fastest acceleration control rotation speed.

Fig. 22 shows the case where the downshift amount of the V-belt type continuously variable transmission is changed in three stages according to the vehicle speed.
In 51, when the vehicle speed V of the hole is V<VL, the input boolean control rotation speed NO is set as NC=RH (953) L,
, when VL<V<Vf-1, set No-RL (9
53) When L,,vH<v, the shift lever setting position D goes to determination 964 and the best fuel efficiency control is performed. >VL, and RL and RH are input pulley rotation speeds set in advance, and the relationship is RH>RL.

Next, the operation of the deceleration pressure t[I mechanism 80 will be explained with reference to FIG. 23.

When the vehicle is traveling at a constant speed, the electromagnetic solenoid valves 84 and 85 controlled by the output of the electric control circuit 9o are turned off, as shown in FIG. 23. As a result, the oil pressure P1 in the oil chamber 816 becomes the line pressure, and the oil pressure P2 in the oil chamber 815 also becomes the line pressure when the spool 812 is on the right side in the figure.

Since the spool 812 has a pressing force P3 due to the spring load of the spring 811, the spool 81 is moved to the left in the figure.
2 is moved to the left, and the oil chamber 815 is connected to the oil passage 2△ and the oil chamber 8.
The spool 812 is communicated with the drain boat 813 through the drain boat 813 and the pressure P2 is exhausted, so that the spool 812 is pushed to the right in the figure by the oil pressure P1 of the oil chamber 816. When the spool 812 is moved in six directions, the drain boat 813 is closed. Therefore, in this case, the spool 812 is connected to the land 8 of the spool 812.
By providing a flat plane (tapered surface) 812b on the edge of the drain boat 813 of 12B, it becomes possible to hold the spool 812 in a more stable state at an equilibrium point at an intermediate position as shown by △ in FIG.

When the oil passage 1b is held at the intermediate equilibrium point as shown in FIG. 23A, the oil passage 1b is closed, and the input pulley 520
The hydraulic pressure of the hydraulic servo 530 is compressed via the V-belt 112 by the line pressure applied to the hydraulic 1/novo 510 of the output pulley 560, and is cohesively balanced with the hydraulic pressure of the hydraulic servo 570.

Actually, since there is oil leakage in the oil passage 1b as well, the input pulley 520 is gradually expanded and the torque ratio T changes in the direction of increasing. Therefore, at the position where the spool 812 is balanced as shown in FIG. A flat tapered surface 812a is provided to compensate for oil leakage in the oil passage 1b. Furthermore, by providing a flange 1 to 812C (tapered surface) at the edge of the drain boat 814 of the land 812A, changes such as the rise and rise of oil pressure changes in the oil passage 1b can be made smooth. In this case, the only line pressure leakage is the pressure oil discharged from the drain boat 813 via the A-refrigerator 82, and there is only one leakage location.

At the time of UP-8HIFT, the electromagnetic solenoid valve 84 is turned on by the output of the electric control circuit 90 as shown in FIG. 23B.

As a result, the oil chamber 815 is depressurized, so the spool 81
2 is moved to the right in the figure, the spring 811 is compressed, and the spool 812 is set to the right end in the figure.

In this state, the line pressure of the oil passage 1a is supplied to the oil passage 1b via the boat 818, so the oil pressure of the oil 1F servo 313 is stored by 1, and the input pulley 520 operates in the direction of closing, and the torque ratio T decreases. do. Therefore, O of the solenoid valve 84
By controlling the N time as necessary, the desired 1-
Reduce the torque ratio by 1 and perform an upshift.

At the time of DOWN-8111FT, as shown in FIG. 23C, the solenoid valve 85 is turned on by the output of the electric control circuit 90, and the oil chamber 816 is evacuated.

The spool 812 is rapidly moved to the right in the figure by the spring load of the spring 811 and the line pressure of the oil chamber 815, the oil passage 1b is communicated with the drain boat 813 and the pressure is exhausted, and the input pulley 520 is moved in the direction of rapid expansion. The torque ratio increases as the solenoid valve 85 operates.
By controlling the N time, the torque ratio is increased and downshifted.

In this way, the hydraulic servo 530 of the input (drive side) pulley 520 is supplied with the output hydraulic pressure of the reduction ratio control valve 81.
Line pressure is introduced to the hydraulic servo 570 of the output (driven side) pulley 560, and the oil pressure of the input pulley 520 is
If the hydraulic pressure of the servo 530 is l)j and the hydraulic pressure Po of the hydraulic servo 570 of the 1-output pulley 560, then P.

/Pi has characteristics as shown in the graph of FIG. 24 with respect to torque ratio T, for example, throttle opening 0-50%,
When driving with torque ratio T = 1.5 < point a in the figure, release the accelerator and set θ = 30%, po/Pi
When the torque ratio T = 0.87 is maintained as it is, it shifts to the operating state shown at the point in the figure, and conversely, the torque ratio T = 0.87, and vice versa.
, 5, the value of Po/Pi is increased by the output of the reduction ratio control mechanism 80 that controls the input boolean and changed to the value at point C in the figure. In this way, by controlling the value of Po/Pi as necessary, it is possible to set a desired torque ratio in response to all load conditions.

As described above, the reduction ratio control method for a continuously variable automatic transmission for a vehicle according to the present invention includes a means for detecting vehicle running conditions such as vehicle speed, throttle opening, output shaft torque, and brake operation, and a method according to the input from the detecting means. an electric control circuit having logic means for outputting an output; and an electric control circuit that is controlled by the output of the electric control circuit to control the supply and discharge of hydraulic fluid to the hydraulic servos of the input and output pulleys, and controls the supply and discharge of hydraulic fluid to the hydraulic servos of the input and output pulleys, and A control device for a continuously variable automatic transmission for a vehicle includes a hydraulic control circuit including a reduction ratio control mechanism that changes the reduction ratio of the V-belt continuously variable transmission according to the throttle opening. When O, the reduction ratio control mechanism in the hydraulic control circuit is outputted to start a town shift, and the reduction ratio control mechanism causes the V-belt continuously variable transmission to start a town shift immediately after the brake is applied, thereby increasing the vehicle speed. Since the downshift 1 is made to the reduction ratio corresponding to the speed, restarting can be done smoothly even if the vehicle suddenly stops while driving at low speed.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view of a continuously variable automatic transmission for vehicles, Figure 2 is a circuit diagram of its hydraulic control device, Figure 3 is a graph of the output hydraulic pressure of the reduction ratio control valve, and Figure 4 is a diagram of the throttle valve. Graphs showing the pressure characteristics of the second slot 1 to 1 output from the throttle valve, Figures 5 and 6 are graphs showing the pressure characteristics of the 1st slot 1 to 1 output by the throttle valve, and Figure 7 shows the characteristics of the pressure output by the low modulator valve. Figure 8 is a graph showing the hydraulic characteristics occurring in the oil passage 2, Figures 9, 10, and 11 are graphs showing the hydraulic characteristics occurring in the oil passage 2.
The figure is a graph showing the line pressure characteristics output by the pressure regulating valve.
Figure 2 is a block diagram of the electronic control circuit, Figure 13 is a graph showing the equal fuel efficiency curve of the fluid coupling, Figure 14 is a hob graph showing the equivalent horsepower curve of the fluid coupling, and Figure 15 is the best fuel efficiency fluid coupling output. 16 is a graph showing the combined output performance characteristics of the engine and fluid coupling at each throttle opening, FIG. 17 is a graph showing the best fuel efficiency manual pulley rotation speed control line, and 18th Figure 1 shows the input booley rotation speed control line when the throttle opening is fully closed; Figure 19 is a block diagram showing the control method of the reduction ratio control mechanism; Figures 20, 21, and 22. 23 is a flowchart for explaining the operation, FIG. 23 is a diagram for explaining the operation of the reduction ratio control mechanism, and FIG. 24 is a graph for explaining the operation. In the diagram: 30... Soup control valve, 40... Throttle valve, 5
0...Reduction ratio detection valve B-I:'I Deputy manager: Kenji Ishiguro. % , =4・1 --1--1++J Figure 3 Figure 6, Figure 9, Figure 19; The flute is Nof 8 Sonta “output times kl
)lshiitoh・/7°Irug output n
14th figure 16 F 1l-L
7
+l-p. Cup or game output times #-number, ('hh7-so(
88] latitude) Fig. 17 ＼ Cabuso 〦 11f gon turn east, ke Nc Fig. 18

Claims (1)

[Claims] 1) An input pulley and an output pulley that are provided on the input shaft and the output shaft, respectively, and whose effective diameters are increased or decreased by a hydraulic servo, and a V-bell 1 to transmit power between the manual pulley and the output pulley. This is a control device for a continuously variable automatic transmission for a vehicle using a V-belt type continuously variable transmission consisting of means for detecting vehicle running conditions such as II speed, throttle opening, output shaft torque, and brake operation; an electrical control circuit comprising logic means for outputting in response to input from the means;
and the output of the electric control circuit, and controls the supply and discharge of hydraulic oil to the hydraulic servos of the input and output pulleys, and controls the V
A control system for a continuously variable automatic transmission for a vehicle consisting of a hydraulic control circuit including a reduction ratio control mechanism that changes the reduction ratio of the belt type continuously variable transmission [II! In the vehicle, when the throttle opening is 0, the electric control circuit causes a reduction ratio control mechanism in the hydraulic control circuit to start downshifting to a reduction ratio corresponding to the vehicle speed. Reduction ratio control method for automatic transmissions.