JPS58170958A - Reduction gear ratio control method of automatic stepless speed change gear for car - Google Patents

Abstract

PURPOSE:To start down shift of a V-belt stepless speed change gear just after the operation of a brake by starting down shift of a reduction gear ratio control mechanism in an oil pressure control circuit when an operation signal of the brake is input. CONSTITUTION:As a reduction gear ratio control for an automatic speed change gear for cars, first a brake signal is detected by a control device, and on stepping on a brake, down shift is immediately started. Thus, when the brake is stepped, and a throttle opening theta is 0, down shift is immediately started by stepping on the brake so as to avoid unnecessary down shift.

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-belt continuously variable transmission.

The V-belt type continuously variable transmission consists of an input pulley and an output pulley, which are installed on the input and output shafts, and whose effective diameters are increased or decreased by a hydraulic servo, and a V-belt that transmits power between these manual pulleys and output pulleys. The continuously variable automatic transmission for vehicles used is suitably used as a continuously variable automatic transmission for vehicles such as automobiles in combination with a fluid coupling such as a torque converter or fluid coupling, and a forward/reverse switching mechanism. However, in this type of automatic transmission for vehicles, when the vehicle suddenly brakes while driving and comes to a stop, the V-belt continuously variable transmission may stop without downshifting to the maximum reduction ratio, and the V-belt while the vehicle is stopped may stop. Since it is difficult to change the speed reduction ratio in a continuously variable transmission, the next time the vehicle starts, a sudden downshift occurs, causing the V-belt to slip, making it impossible to restart the vehicle 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, which 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 the control w@t of a continuously variable automatic transmission for a vehicle that uses a V-belt type continuously variable transmission consisting of these human-powered pulleys and a V-belt that transmits power between the output turn and the output turn.
An electric control circuit includes means for detecting vehicle running conditions such as output shaft torque and brake operation, and logic means for outputting in accordance with input from the detecting means, and is controlled by the output of the electric control circuit, and the human power from a hydraulic control circuit including a reduction ratio control mechanism that controls the supply and discharge of hydraulic oil to the hydraulic servo of the pulley and the output pulley, and changes the reduction ratio of the V-belt continuously variable transmission according to the vehicle running conditions; In the control device for a continuously variable automatic transmission for a vehicle, when a brake activation signal is input, the electric control circuit outputs an output to a reduction ratio control mechanism in the hydraulic control circuit to start a downshift, thereby The reduction ratio control 1 mechanism is configured to cause the V-belt continuously variable transmission to start downshifting immediately after the brake is applied.

Next, the present invention will be explained based on an 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 a fluid coupling room 110 which is open on the opposite side from the engine and in which differential gears are stored and the differential gear is stored. A torque converter case 200 has a differential room 120 that supports one output shaft, and an idler gear room 130 that is open on the side opposite to the engine and that accommodates an idler gear and supports one of the shafts of the idler gear. A transmission room 2101 which is open and houses a V-belt continuously variable transmission; a differential room 220 which covers the opening surface of the differential room of the torque converter case and supports the other output shaft of the differential; J'3 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, and the side surface 100 of the torque converter case opposite to the engine.
The transmission case is fastened to B with bolts, and forms the outer shell (case) of the automatic transmission for a vehicle together with the above-mentioned 1 to LU converter cases and an intermediate case to be described later. Reference numeral 300 designates a center case that pivotally supports the transmission shaft between the fluid coupling and the transmission, and in this embodiment, it is bolted to the side 100B of the torque converter case opposite to the engine while being housed in the transmission case. ! ζ Has a center case configuration. automatic change 3
! In this embodiment, the machine includes a known fluid coupling 400 disposed in a lux converter case 100 and connected to the output shaft of the engine, and a transmission case 200.
It consists of a transmission installed inside. The transmission includes an input shaft 5 whose shaft center is hollow, and the hollow portion 511 serves as an oil supply and drainage path for hydraulic oil and lubricating oil for a hydraulic servo.
10 is arranged to have a coaxial center with the fluid coupling 400, the shaft center is hollow, and the hollow part 511 is used as an oil supply/drainage path for hydraulic oil of a hydraulic servo.
is a V-belt continuously variable transmission 500 arranged parallel to the input shaft 510, and an input shaft 510 of the V-belt continuously variable transmission.
and the planetary gear transmission mechanism 600 disposed between the output shaft of the fluid coupling and the V-belt continuously variable transmission 500.
A differential 700 in which an output shaft 710 is connected to an axle and is arranged parallel to an input shaft 510 and an output shaft 550, and an input large gear 720 of the differential 700 and the output of the V-belt continuously variable transmission 500. It is inserted between the output gear 590 of a V-belt type continuously variable transmission provided at the end of the shaft 550 near the engine, and parallel to the output shaft 550, one end is pivotally supported by the torque converter case. An idler gear shaft 8 whose end is pivotally supported by a center case 300 serving as an inner case
10, and an input gear 820 provided on the idler gear shaft.
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 cover which is fastened to the wall of the center case near the fluid coupling where the engine is located, and which houses an oil pump 106 driven by a hollow shaft 410 that is integrated with the fluid coupling 400. be.

The output shaft 420 of the fluid coupling 400 is rotatably supported by a sleeve 310 fitted in the center of the center 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 turbine 450 with 7 roof coupling springs.
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 formed hollow,
In the hollow part, an oil passage 421 is installed and a plug 420 is fitted, and the input shaft 5 of the V-belt type continuously variable transmission is fitted.
The engine side end of the sleeve 422 fixed to the sleeve 10 is rotatably fitted.

The planetary m heavy speed 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 7-lunge of a V-belt type continuously variable transmission, which will be described later, via a multi-disc clutch 630. Connected carrier 6
20, center case 30 via multi-plate brake 650
0, a sun gear 67o1 is provided 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.
A planetary gear 640 is pivotally supported by the carrier 620 and meshed with the sun gear 670 and the ring gear 66, and the multi-disc brake 65 is formed on the wall of the center case 300.
0, a hydraulic servo 6801 formed on the fixed 7 flange wall, and a hydraulic servo 69 that operates the multi-disc clutch 630.

The V-belt continuously variable transmission 500 has a planetary gear transmission mechanism 60.
0 output shaft 610 and an input shaft 510 integrally formed with a fixed 7-lunge 520Δ, and a movable 7-lunge 5213 driven by a hydraulic servo 530 in the fixed 7-lunge 52Δ direction; A fixed 7-lunge 560A formed integrally with the output shaft 550 of the V-belt type continuously variable transmission, and a movable 7-lunge 560 driven in the direction of the fixed flange 560A by the hydraulic servo 57.
3, and a V-belt 580 that transmits power between the input pulley 520 and the output pulley 560.

The input shaft 510 of the V-belt type continuously variable transmission has an engine side end 510 that serves as the output shaft 610 of the planetary gear transmission mechanism.
Δ is supported by the input shaft 601 of the planetary gear transmission mechanism via a bearing 340, supported by the center case 300 via the input shaft 601 and the bearing 330, and the other end 510B is supported by the transmission case via a bearing 350. It is supported by the side wall 250 opposite to the engine, and furthermore, its distal end surface 510C is fastened to the side part 250 and abuts against the IC lid 260 via a needle (roller) bearing 270.

A hollow portion 511 formed at the center of the input shaft 510 of the V-belt continuously variable transmission has the sleeve 42 attached to the side of the engine.
2 is fitted, and the engine side part 511A sends 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 the oil passage 513 formed at the base of the fixed 7 flange 520A. The opposite side portion 511B serves as an oil passage for supplying hydraulic pressure, and the opposite side portion 511B is a lid 26 whose tip is attached to close a hole 250Δ formed in a portion of the side wall 250 of the transmission case that corresponds to the input shaft 510.
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.
The pressure oil supplied through the protruding portion 261 of 0 acts as an oil passage for being supplied to the hydraulic servo 530.

The output gear 590 is formed integrally 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 an engine side end 591A forming one support point, and the other end 591B. is supported by the center case 300 via a roller bearing 593, and is further supported by the engine side surface 59 of the output gear 590.
0△ is in contact with the side wall of the torque converter case via a needle bearing 594 forming an intermediate fulcrum,
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 an inner spline 596 is formed on the support shaft 591 on the side of the transmission.

The output shaft 550 of the V-belt type continuously variable transmission (well, at the engine end there is an outer spline 550A that fits into the inner spline 596 formed on the support shaft 591 of the output gear).
is formed, and the support shaft 59 of the output gear is formed by spline fitting.
1 and supported by the center case 300 via the other end 55
0B connects the transmission case to the opposite side of the engine via the ball bearing 920 that forms the other fulcrum.
250 and supported by C' l+).

A sensing tube body 552 is fitted in the middle part of the oil passage 551 formed at the axis of the output shaft 550 of this Pell 1 continuously variable transmission, and the engine side part 552A of the valve body 552 is The hydraulic pressure supplied from the oil passage 140 formed in the transmission case and communicating with the hydraulic control device is an oil passage through which the hydraulic pressure is supplied to the hydraulic servo 570.
52B is a hole 250 whose tip is formed in a portion corresponding to the output shaft 550 of the side wall 250 of the transmission case.
Pipe-shaped protrusion 55 of the lid 553 placed on the lid so as to close B
4 and is formed in the transmission case and the lid 553 fastened to the transmission case, and serves as the oil passage 3 in which the oil pressure is adjusted by the reduction ratio detection valve 50 that detects the displacement position of the movable flange 560B from the hydraulic control device. There is. In the reduction ratio detection valve 50, an engagement pin 51A attached to the right end of the detection rod 51 as shown in the drawing is attached to a movable flange 560.
The oil passage 3 is engaged with the stepped portion 561 formed on the inner periphery of the spool 560B, and the oil passage 3
Adjust the oil pressure.

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
adjusts the line pressure supplied from the oil passage 1 in accordance with throttle opening, outputs it as the first throttle pressure from the oil passage 2, and the reduction ratio detection valve 50 is supplied from the oil passage 3 via the orifice 22. 50 is a throttle valve that outputs the reduction ratio pressure output from the oil passage 3a as a second throttle pressure when the throttle opening is equal to or higher than the set value 01; The reduction ratio detection valve 60, which regulates the pressure according to the displacement of the movable flange 5603 that increases the output of the V-belt type continuously variable transmission, communicates with the oil passage 1 via the orifice 24, and also communicates with the pressure regulation valve 30. A second pressure regulating valve 65 is provided at each operating level to regulate the oil pressure of the oil passage 4 through which surplus oil is discharged and to supply the surplus oil passage from the oil passage 5 as lubricating oil to the parts requiring lubrication of the continuously variable automatic transmission. A manual valve 70 is actuated by a shift lever and distributes the line pressure of the oil passage 1 according to the driver's operation; A lock-up control mechanism 80 that controls engagement and release outputs the hydraulic pressure of the oil passage 1a, which communicates with the oil passage 1 via the large-diameter orifice 25, from the oil passage 1b to the hydraulic servo 530 of the input pulley according to the input. ■ A belt type continuously variable 1TA500 reduction ratio (torque ratio) control mechanism, 10 is installed in the oil passage 1C that communicates with oil passage 1 when the manual valve 65 is shifted to the L range, and regulates the line pressure. 12 is a relief valve provided in the oil cooler oil path 11; 25 is a relief valve provided in the oil path 1; 26 is a relief valve provided in the oil path 1; A check circulation flow control valve provided in the line pressure supply oil passage 6 to the hydraulic servo 680 of the plate brake, 27 is a planetary gear transmission mechanism 3
This is a check rotation flow rate control valve provided in the line pressure supply oil passage 7 to the hydraulic servo 690 of the multi-disc clutch shown in FIG.

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 one end wound around an engagement pin 51A that engages with a movable flange 560B of an output pulley of a V-belt type continuously variable transmission, and a spring 52 provided in front of the other end. ,
A spool 54 having lands 54A and 543 arranged in series through the detection rod 51 and the spring 53, a boat 55 communicating with the oil passage 3, a drain boat 56, and a boat 55 and lands 54Δ and 5413 provided on the spool 55.
The hydraulic pressure Pi as shown in FIG. 3 is generated in the oil passage 3 according to the displacement of the movable 7-lunge 560B.

The throttle valve 40 includes a throttle plunger t42 that is displaced in contact with a throttle cam 41 linked to an accelerator pedal on the driver's seat, a spool 44 that is connected in series with the throttle plunger 42 via a spring 43,
As the throttle opening degree θ increases, the plunger 42 and the spool 44 are displaced to the left in the drawing. Plunger 42
When the rotation angle of the throttle cam 41 and the hydraulic throttle opening e of the oil passage 2 fed back to the land 42a become equal to or higher than the set value e1 (θ>01), the oil passage 3 and the oil passage 3
a to produce a second throttle pressure equal to the reduction ratio pressure in the oil passage 3a, and when e is θ1, the plunger 4
Drain boat 40 via oil passage 42B provided in 2
The hydraulic pressure in the oil passage 3a is discharged from the oil passage 3a, and a second throttle pressure Pj is generated in the oil passage 3a as shown in FIG.

The movement of the throttle cam is transmitted to the spool 44 via the spring 43, and the spool 44 is displaced by the throttle opening and the oil pressure of the oil passage 2 fed back to the land 44a via the orifice 45, thereby increasing the communication area between the oil passages 1 and 2. The throttle pressure 1-"th generated in the oil passage 2 is adjusted as shown in FIGS. 5 and 6.

The pressure regulating valve 30 has a spring 31 disposed in front on one side (left side in the figure), a spool 32 provided with lands 32A and 328132G, a spool 32 disposed in series with the spool 32, and a small-diameter land 33△ and a large-diameter land. 33B, and a second regulator plunger 34 arranged in series in contact with the plunger 33.
A boat 34a1 and an orifice 3 that communicate with the oil passage 1
Boat 34 to which line pressure is fed back via 5
b Drain port 34c1 Boat 34d for discharging surplus oil into oil passage 4 Drain port 34e for discharging leaked oil from between the land and valve wall, input port 34f1 for inputting the reduction specific pressure from oil passage 3 Oil passage 2 The input port 34o receives the first throttle pressure from the oil passage 3a, and the input port 34h receives the second throttle pressure from the oil passage 3a.

The low modulator valve 10 outputs a low modulator rXPlow shown in FIG. 7 that is independent of the throttle opening when the manual valve 70 is set to the forward range. Here, both the low modulator valve and the throttle valve have no exhaust pressure oil passage for vA, and are configured to regulate the throttle pressure pth by utilizing the fact that it is constantly exhausted from the reduction ratio control mechanism 80. , and both these valves are arranged in parallel.

Therefore, in the microwave, there is a Plow line in oil path 2 as shown in Figure 8.
The larger hydraulic pressure will be generated. Therefore, as shown in FIG. 9, the line pressure PL in the range low throttle opening is higher than in the D range.

This pressure regulating valve 30 is configured to control the reduction specific pressure inputted from the boat 34f and applied to the second plunger 34, the first throttle pressure inputted from the boat 34Q and applied to the land 33B of the first plunger 33, and the first throttle pressure inputted from the boat 34h and applied to the land 33B of the first plunger 33. 1 through the second throttle pressure spring 31 applied to the land 33A of the first plunger 33 and the orifice 35
The spool land 32c from the boat 34b that was contacted
The spool 42 is
is displaced and the opening areas of the boat 34a communicating with the oil passage 1, the boat 34d communicating with the oil passage 4, and the drain boat 34c are adjusted to increase or decrease the leakage of pressure oil in the oil passage 1, as shown in FIGS. 9 and 10. , and the line pressure PL shown in FIG.

In the 1-range, it is necessary to downshift to obtain strong engine braking. Hydraulic servo 530 with V-belt continuously variable transmission has a slow input when downshifting.
By connecting the oil passage to the exhaust pressure oil passage, the oil in the servo oil chamber can be drained and a downshift can be achieved. However, in order to obtain strong engine braking, it is necessary to rotate the primary sheave at a high rotation speed, and the hydraulic 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 make the hydraulic pressure applied to the hydraulic servo 570 of the output pulley higher than normal, which is particularly important when the throttle opening is low. For this reason, in the Nishi range, the low modulator valve is used to adjust the throttle +t, pt when the throttle opening θ is small.
h is increased, and the line pressure PL (line pressure - hydraulic servo supply pressure of the output pulley) is increased.

The manual valve 65 is a shift lever installed in the driver's seat.
It has a spool 66 that is set to each shift position of P (park), R (reverse), courtral (N), D (drive), and L (low), and when set to each shift position. Oil passage 1 or oil passage 2, oil passage 1c oil passage, 6
Connect with oil passage 7 as shown in Table 3.

Table 1 RNDL Oilway 7 × × × △ △ Oilway 6 × ○ ××× Oilway IG −−△ △ ○ In Table ■, ○ indicates communication with oilway 1, △ indicates communication with oilway 2, and - indicates connection with oilway 2. Blockage of oil passage, × indicates exhaust pressure. As shown in this table (■), line pressure is supplied to the brake 680 of the M star gear transmission mechanism in the R range, and throttle pressure (or low modulator pressure) of the oil passage 2 is supplied to the clutch 690 in the D and - ranges. The vehicle is then switched between forward and reverse.

The 21st ill pressure valve 60 has a spool 62 with a spring 61 installed in front on one side and lands 62A, 62B, and 62C.
The spool 62 is displaced by the spring load of the spring 61 and the hydraulic pressure applied to the land 62Δ via the orifice 63, and is connected to the oil passage 4, the oil passage 5, and the drain boat 6.
The oil pressure in the oil passage 4 is regulated by changing the flow resistance of 0A, and lubricating oil is supplied from the oil passage 5 to the parts requiring lubrication, and excess hydraulic oil is drained from the drain boat 60A.

The reduction ratio control I1 mechanism 80 includes a reduction ratio control valve 81, orifices 82 and 83, and an upshift electromagnetic solenoid valve 84.
, and a downshift electromagnetic solenoid valve 85.

The reduction ratio control valve 81 has a first land 812A, a second land 812B, and a third land 812C, and one land 812C has a spool 812 in which a spring 811 is installed in front, and a spring 811 is connected to the spool 812 through orifices 82 and 83, respectively. side end oil chambers 815 and 816, land 81 at both ends to which throttle pressure or low modulator pressure is supplied from the oil passage 2;
Intermediate oil chamber 810 between 2B and land 812C, oil chamber 8
15 and the oil chamber 810, an input port 817 and V that communicate with the oil path 1 to which line pressure is supplied and whose opening area increases or decreases according to the movement of the spool 812.
Output boat 8 connected to hydraulic servo 530 of input pulley 520 of belt bottom continuously variable speed @ 500 via oil path 1b
18, and a drain boat 814 that evacuates the oil chamber 819 according to the movement of the spool 812.
, 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 downshift electromagnetic solenoid valve 85 are the reduction ratio control valve 81, respectively.
oil chamber 815 and oil chamber 816, both of which are operated by the output of an electric control circuit to be described later.
15 and the oil chambers 810 and 816 are evacuated.

The lock-up control am mechanism 70 includes a lock-up control valve 71
, an orifice 77, and an electromagnetic solenoid valve 7G that controls the oil pressure of the oil passage 4a that communicates with the oil passage 4 via the orifice 17. The lock-up control valve 71 has a spring 12 installed in front of it on one side (right side in the figure), and a spool 73 equipped with lands 73A173 [3, 73C] of the same diameter.
and a sleeve 75 which is provided in series with the spool 73 and has a spring 74 in front of the other (left side in the figure) and has a larger diameter than the land of the spool 73,
The oil pressure P4 of the oil passage 4 and the spring load FS1 of the spring 72 are applied to the land 73C through the input port door 1A connected to the input port door 1A. 4a solenoid pressure P
The spool 73 is displaced in response to the hydraulic pressure P8 in the oil passage 8 on the release side of the lock-up clutch 430 applied to the land 73A via the boat 41B and the spring load I F s2 by the spring 74, and the spool 73 is displaced. The release goggle controls communication with the oil passage 8 or the engagement side of the lock-up clutch 430 with the oil passage 9. When the solenoid valve 76 is energized and turned ON, the oil pressure in the oil passage 4a is discharged, the spool 73 is fixed to the left in the figure, and the oil passage 4 and the oil passage 9 are
and the hydraulic oil flows from oil line 9 to lock-up clutch 4.
30→oil path 8→drain boat 71C, and lock-up clutch 430 is in an engaged state. When the 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 is is oil road 8→
Flows in the order of lock-up clutch 430 → oil passage 9 → oil cooler connecting oil passage 10, and lock-up clutch 43
0 is free.

Figure 12 shows the electromagnetic solenoid valve 7 of the lock-up clutch controller 4f170 in the hydraulic control device shown in Figure 2.
6. The configuration of an electric control circuit 90 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, R, N, or L; 92;
is a rotation speed sensor that detects the rotation speed of input pulley △,
93 is a vehicle speed sensor; 94 is a throttle sensor that detects the throttle opening of the engine; 95 is a brake switch that is turned on when the brake is activated; 96 is a speed detection processing circuit that converts the output of the rotational speed sensor 92 into voltage;
7 is a vehicle speed detection circuit that converts the output of the vehicle speed sensor 93 into a voltage, 98 is a throttle distance detection processing circuit that converts the output of the throttle sensor 94 into voltage, 907 to 911 are input interfaces for each sensor, and 912 is a central processing unit. (
CPU), 913 is ffi! Magnetic solenoid valve 76.84
．． 914 is a random access memory (RAM) that temporarily stores input data and parameters necessary for control; 915 is a clock; 916 is an output interface, 917 is a solenoid output driver, and output interface 916
is converted into the operating output of the downshift electromagnetic solenoid valve 85, the upshift 1i magnetic solenoid valve 84, and the shift control solenoid 74. Input interfaces 908 to 911, CPU912, ROM913, R
AM 914 and output interface 916 are communicated via data bus 918 and address bus 919.

Next, the operation of the reduction ratio control mechanism 80 controlled by the electric control circuit 90 is illustrated in FIGS. 13 to 26.

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

The reduction ratio control mechanism 80 is controlled by increasing or decreasing the speed ratio between the input and output pulleys by comparing the best fuel efficiency manual pulley rotation speed and the actual input pulley rotation speed N. Two electromagnetic solenoid valves 84 and 85
The actual input pulley rotation speed N is made to match the best fuel efficiency manual pulley rotation speed. 1, the best fuel efficiency fluid coupling output line can be obtained from the equal fuel consumption rate curve (Figure 13) and the equal horsepower curve of the fluid coupling output (Figure 14). (Fig. 15), this best fuel efficiency fluid coupling combined output line and the engine + fluid coupling combined output performance at each throttle opening θ
6), the best fuel efficiency fluid coupling output rotation speed (first
Figure 7) is required. 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 has been performed even when the throttle opening is fully open. However, when the brakes are applied suddenly, the downshift cannot catch up, so even if the vehicle has stopped, the downshift may not have been completed. However, there was a problem in that the belt slipped and the transmission could not be re-transmitted smoothly. To solve this problem, it is possible to downshift quickly, but the time required to complete the downshift (the time required to move the pulley from a certain reduction ratio position to the maximum reduction position) must be extremely shortened. It is technically difficult to do so.

However, when the best fuel economy is limited as described above, the downshift does not start immediately even when the brake is applied, and the drive sheave rotation speed at that time is such that the best fuel economy is achieved when the throttle is fully open. If the rotation speed is higher than that, it will upshift. 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 vehicle speed decreases.

Therefore, by starting the downshift l- from an early stage, even if the brakes are suddenly applied, it is possible to downshift more before stopping the vehicle. Therefore, a method can be considered that causes the electric control circuit to immediately issue a downshift signal when the throttle opening becomes fully open, and causes the hydraulic control circuit to start downshift l~. However, with this method,
For example, when the throttle is fully opened at high speeds, strong engine braking is applied, which is dangerous and does not give a good driving feeling. Also, while driving at high speed, even if you release the accelerator and drive with throttle opening θ = 0, the vehicle will often coast, and even if you apply the brakes, there will be enough time to stop, so V The downshift of the belt-type continuously variable transmission can be completed with ample time and does not require a very fast downshift.

Therefore, as a first method for controlling the reduction ratio of an automatic transmission for a vehicle, first, the controller is made to be able to detect a brake signal.
Cover so that the downshift begins immediately when the brake is pressed. In this way, the above problems are almost solved,
Further, by starting the downshift immediately when the brake is depressed and the throttle opening is e-O, unnecessary downshifts can be avoided. However, since the time from when the brake is applied to when the vehicle stops is shorter as the vehicle speed is lower, if the brakes are suddenly applied, it may not be possible to downshift in time just by detecting the brake signal. Therefore, as a second method for controlling the reduction ratio of the automatic transmission for a vehicle, the vehicle speed is further detected, and the lower the vehicle speed is, the lower the shift 1 is. In this way, when the brake is depressed, the lower the vehicle speed, the smaller the shift width, and the downshift can be completed in a shorter time. Furthermore, when the accelerator is released at high speed, the degree of engine braking can be reduced, improving safety and driving feeling.

FIG. 19 shows a block diagram of the control circuit of the V-belt continuously variable transmission. Shift 1 - By inputting the lever shift position, input pulley rotation speed N, vehicle speed V, throttle opening θ, and brake signal, the upshift electromagnetic solenoid turns the downshift electromagnetic solenoid ON or OFF, thereby changing the gear ratio. control.

After reading 921 the throttle opening degree θ using the throttle sensor 904, the input pulley rotation speed sensor 92
Then, the input pulley rotation speed and vehicle speed are read 922 using the vehicle speed sensor 93, the brake signal is read 923 using the brake switch 95, and the shift position is read 924 using the shift lever switch. After reading this information, shift lever switch 901
The shift 1-lever position is determined 925 by P, N.
The process advances to a subroutine 930 for processing, a subroutine 940 for L and D processing, or a subroutine 960 for R processing. Second
0 to 23 show a flowchart of the control circuit shown in FIG. 19, and FIG. 24 shows a graph for explaining the operation.

b) When the shift lever is set to the P position or the N position, both the upshift electromagnetic solenoid valve 84 and the downshift electromagnetic solenoid valve 85 are set to 0FFL by the P position and N position processing subroutine 930 shown in FIG.
(931) The P or N state is stored in the RAM 914. (932) As a result, the nicotral state of the hekapulley 520 is obtained.

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

According to the first method for controlling the reduction ratio of an automatic transmission for a vehicle, the upshift electromagnetic solenoid valve 84 and the downshift electromagnetic solenoid valve 85 are operated as shown in the flowchart of FIG. Control.

If the brake is not pressed, the throttle is not fully closed, and the shift lever is in the D position, the best fuel efficiency control is performed. In this case, the best fuel efficiency control line in FIG.
3 in the form of a table, the input pulley rotation speed corresponding to the throttle opening is subtracted from the table, and control is performed using the input pulley rotation speed as the input boolean control rotation speed. That is, if the input pulley rotation speed N is larger than the input pulley control rotation speed NO, the upshift 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 or not there is a brake signal. When there is a brake signal (ON), the brake flag is 0N94.
2 and set the input pulley control rotation speed to RH (943
) L, Next, compare the current input pulley rotation speed N with the input pulley control rotation speed NO (944). If N>NC, turn on the upshift electromagnetic solenoid L//-1'l'84.
(945), and when N<NO, the downshift electromagnetic solenoid 85 is turned ON (946), and when N=NO, both solenoid valves 84 and 85 are turned OFF (947).
). When there is no brake signal (OFF), it is determined whether the throttle opening e is 0 or not (950), and when θ-0, it is determined whether the brake flag is ON or OFF (950).
52), and when the brake flag is ON, the input pulley control rotation speed is set to RH (943). When the brake flag is OFF, the relationship between the current vehicle speed V and the set vehicle speeds VL and VH (VL<VH) is determined (954), and when V<VL, the input pulley control rotation speed is set to RM (956). ) L, proceed to comparison 944 of the current input pulley rotation speed N and input pulley control rotation speed NC. Also, VH
＞V≧VL, input pulley control rotation speed is RL (R
L < RM < RH), and a comparison 944 is performed between the current input pulley rotation speed N and the input boolean control rotation speed NO. When the brake is not activated and the throttle opening is 0-0, the best fuel efficiency control is performed. That is, in the determination 950 of whether the throttle opening degree θ is O or not, when θ-0, the brake flag is turned 0FF962, and then the vehicle speed V and the set vehicle speed V
When the relationship between L and VH is determined 954, when V≧VH, a determination 964 is directly performed as to whether the set position of the shift lever is in the forward range or in the D range.
Set the input boolean control rotation speed Nc corresponding to the throttle opening θ from the D range table in OM 913 to achieve the best fuel efficiency (965).
Input the data from the range table in 13 and set the manual control rotation speed NG corresponding to the throttle opening θ (
966) L...In either case, the process proceeds to 944, where the current input pulley rotation speed N is compared with the input pulley control rotation speed NO.

The control method is the same when the shift lever is set to the extended position, but the input pulley control rotation speed NO relative to the throttle opening θ is generally higher than that for the best fuel efficiency control (shift lever D position). For example, the speed is set to the fastest acceleration control rotation speed. Even if the throttle opening θ is fully open, the same control is performed if the vehicle speed is equal to or higher than VH.

When the throttle opening is fully closed (e = o) and the vehicle speed is below VH, the input pulley control rotation speed is set to RL (the control rotation speed when the shift lever is in the L position, the throttle opening is fully closed, and the vehicle speed is VH). Set the rotation speed to Nc or higher.

Further, when the vehicle speed becomes equal to or lower than VM (VM<VH), the input pulley control rotation speed NO is set to RM (RM>RL). In addition, when the brake is stepped on, the input pulley control rotation speed NO is RH (R1-1>
RM). This state is maintained even if the brake is released, and is released by depressing the accelerator. In this way, when the throttle opening θ is fully closed,
The rotation speed of the input pulley is controlled in three stages depending on the vehicle speed, but it can be controlled in any number of stages by changing the program.

FIG. 22 is a flowchart of a program when controlling with an arbitrary number of stages. When the throttle opening Be is not fully open, the control is the same as that shown in FIG. 20, but when the throttle opening O is fully open, the input pulley corresponding to the vehicle speed is (971, 972).

At this time, the control line shown in FIG. 18, like the best fuel economy control line, is stored in the memory in the form of a table, and the rotational speed corresponding to the vehicle speed is extracted from the table for control. With this method, if you want to increase the number of shift stages or change the shift point, you only need to change the table, with almost no changes to the program.

Further, as shown in FIG. 24, when the input pulley control rotation speed NC is expressed as a relatively simple function of vehicle speed, it is not necessary to have a table.

A flowchart of this process is shown in FIG. When the brake flag is ON (942), it is determined 981 whether the vehicle speed V is less than or equal to S-. ) Then, the process proceeds to 944, where the current rotation speed N of the manual pulley is compared with the control rotation speed NO. Here, S' is the set vehicle speed, k21 is a constant, and RH is the set inlet J pulley rotation speed. Also, when v >S', the input pulley control rotation speed N
Set 0=R”H (983) and proceed to 944.Furthermore, turn off the brake flag at throttle opening θ-〇 (fully closed).
In this case, it is determined whether the current vehicle speed V is greater than or equal to S- (984
), and when V>S=, the manual pulley control rotation speed Nc
=R'H and proceed to 944. When V<S-, NC-
(S--V) xkll +R-L to LT 944 hem.

kll is a constant, R-L is the set input pulley rotation speed (R
=L<R=H). In this method, the vehicle speed V is taken into consideration, and the lower the vehicle speed is, the more the vehicle is shifted to the down side. Furthermore, as shown in FIG. 24, the input pulley control rotational speed Nc can be expressed as a relatively simple function of vehicle speed, which not only eliminates the need for a table but also allows the maximum number of shift stages.

Next, the operation of the reduction ratio control m+ mechanism 80 will be explained with reference to FIG. 25.

When the vehicle is running at a constant speed, the electromagnetic solenoid valves 84 and 85 controlled by the output of the electric control circuit 90 are turned off, as shown in FIG. 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 2A and the oil chamber 8.
The spool 812 is communicated with the drain boat 813 via the drain boat 813 and pressure is discharged, so the spool 812 is moved to the right in the figure by the oil pressure P1 of the oil chamber 816. When spool 812 is moved to the right, drain port 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 1 813 of 12B, it is possible to more stably hold the spool 812 at the equilibrium point at the intermediate position as shown in FIG. 26A. Become.

When the oil passage 1b is maintained at the intermediate equilibrium point as shown in FIG. 25 Δ, the oil passage 1b is closed and the input pulley 520
The oil pressure of the t-bo 530 is compressed via the V-belt 112 by the line pressure applied to the hydraulic servo 570 of the output pulley 560, and as a result, the oil pressure of the t-bo 530 is in equilibrium with the oil pressure of the hydraulic servo 570. do.

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

During UP-8HIFT, the upshift electromagnetic solenoid valve 84 is turned on by the output of the electric control circuit 90, as shown in FIG. 25B.

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 hydraulic servo 313 increases, the input pulley 520 operates in the closing direction, and the torque ratio T decreases. Therefore, the solenoid valve 84 is turned ON.
The upshift is performed by reducing the desired torque ratio by controlling the time as necessary.

During DOWN-8HIFT, as shown in FIG. 25C, 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 port 813 and the pressure is discharged, and the input pulley 520 is moved in the direction of rapid expansion. As a result, the torque ratio T increases. In this way, the O of the solenoid valve 85
By controlling the N time, the 1~lux 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 led to the hydraulic servo 570 of the output (driven side) boob 9560, and if the hydraulic pressure of the hydraulic servo 530 of the input tube 9520 is Pl, and the hydraulic pressure PO of the hydraulic servo 570 of the output pulley 560 is P.

/Pi has characteristics as shown in the graph of FIG. 26 with respect to torque ratio T, for example, throttle opening 0-50%,
When driving at torque ratio T-1,5' (point a in the figure), release the accelerator and set it to 0 = 30% po/p
When i is maintained as it is, torque ratio T = 0.87
The state shifts to the operating state shown at the point in the figure, and conversely the torque ratio T=
1.5, the value of PO/Pi is increased by the output of the reduction ratio control mechanism 80 that controls the input pulley and changed to the value at point C in the figure. In this way, by controlling the value of Po/Pi as necessary, a desired torque ratio can be set in response to all load conditions.

As described above, the reduction ratio control method for a continuously variable automatic transmission for vehicles 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 for controlling a reduction ratio in a continuously variable automatic transmission for a vehicle 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 oil to the hydraulic servo of the input pulley and the output boolean, and that In a control device for a continuously variable automatic transmission for a vehicle, comprising 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 When input, it outputs a command to the reduction ratio control mechanism in the hydraulic control circuit to start downshifting, and as a result, the reduction ratio control mechanism causes the belt type continuously variable transmission to immediately start downshifting after applying the brake. , even if the vehicle comes to a sudden stop while driving at low speeds, it is possible to restart the vehicle smoothly. Furthermore, by shifting to the down side the slower the vehicle speed is, it is possible to more reliably complete the downshift when stopping suddenly.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of a continuously variable automatic transmission for vehicles, Fig. 2 is a circuit diagram of its hydraulic control device, Fig. 3 is a graph showing the output hydraulic characteristics of the reduction ratio control valve, and Fig. 4 is a graph showing the output hydraulic characteristics of the reduction ratio control valve. Graphs showing output second throttle pressure characteristics, Figures 5 and 6
Figure 7 is a graph showing the first throttle pressure characteristics output by the throttle valve, Figure 7 is a graph showing the low modulator pressure characteristics output by the low modulator valve, Figure 8 is a graph showing the hydraulic characteristics occurring in oil passage 2, Figure 9, Figure 10, Figure 11
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 equal fuel consumption curves of fluid couplings, Figure 14 is a graph showing output equal horsepower curves of fluid couplings, and Figure 15 is the best fuel efficiency fluid coupling. A graph showing the output line, Fig. 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 rotation speed control line, and Fig. 18 is a graph showing the combined output performance characteristics of the engine and fluid coupling at each throttle opening. A graph showing the input pulley rotation speed control line when the throttle opening is fully closed, Fig. 19 is a block diagram showing the control method of the reduction ratio control m mechanism, Figs. 20, 21, 2
Figures 2 and 23 are flowcharts for explaining the operation, and Figure 24 is a characteristic graph 1 of vehicle speed and input boolean rotation speed.
, Fig. 25 is an explanatory diagram of the operation of the reduction ratio control t[1 mechanism, Fig. 26
The figure is a graph for explaining its operation. In the diagram: 30...pressure regulating valve, 40...throttle valve, 5
0... Reduction ratio detection valve whistle 3 Figure 6F-1 - Volume 1 9G To IL-2 1゛31 □, ;15 171 L?
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Claims (1)

[Claims] 1) An input pulley and an output pulley that are provided on the input shaft and output shaft, respectively, and whose effective diameters are increased or decreased by a hydraulic servo, and a V-belt that transmits 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 a means for detecting vehicle running conditions such as vehicle speed, throttle opening, output shaft torque, and brake operation, and the detecting means. an electric control circuit comprising logic means for outputting an output according to an input from the electric control circuit; and an electric control circuit that is controlled by the output of the electric control circuit and controls the supply and discharge of hydraulic oil to the hydraulic servo of the input pulley and the output pulley; In a control device for a continuously variable automatic transmission for a vehicle, comprising a hydraulic control circuit including a reduction ratio control mechanism that changes the reduction ratio of the V-belt continuously variable transmission according to vehicle running conditions, the electric control circuit comprises: When a brake activation signal is input, it is output to the reduction ratio control mechanism in the hydraulic control circuit to start downshifting, and as a result, the reduction ratio control mechanism causes the V-belt continuously variable transmission to immediately start downshifting after the brake is applied. A reduction ratio control method for a continuously variable automatic transmission for a vehicle, characterized by starting a downshift. 2) An input pulley and an output pulley are installed on the input and output shafts, and the effective diameter is increased or decreased by a hydraulic servo! This is a control device for a continuously variable automatic transmission for vehicles that uses a V-belt type continuously variable transmission consisting of a V-belt that transmits power between the human pulley and the output pulley, and controls vehicle speed, throttle opening, and output shaft. An electric control circuit includes means for detecting vehicle running conditions such as torque and brake operation, and logic means for outputting an output according to input from the detecting means, and is controlled by the output of the electric control circuit, and the input boolean is and a hydraulic control circuit including a reduction ratio control mechanism that controls the supply and discharge of hydraulic oil to the hydraulic servo of the output pulley and changes the reduction ratio of the continuously variable transmission between the V-belt and the V-belt depending on the vehicle running conditions. In a control device for a continuously variable automatic transmission for a vehicle, when a brake activation signal is input and a throttle opening θ is 0, the electric control circuit causes a downshift i to a reduction ratio control mechanism in the hydraulic control circuit. A reduction ratio control method for a continuously variable automatic transmission for a vehicle, characterized in that the reduction ratio control mechanism causes the V-belt continuously variable transmission to start downshifting immediately after the brake is applied. . 3) V-belt type continuously variable transmission consisting of an input pulley and an output pulley, which are installed on the input and output shafts, and whose effective diameters are increased or decreased by a hydraulic servo, and a V-belt that transmits power between these manual pulleys and the output knob. This is a control device for a continuously variable automatic transmission for vehicles that uses a device to detect vehicle running conditions such as vehicle speed, throttle opening, output shaft torque, and brake operation, and outputs according to the input from the detection device. an electrical control circuit comprising logic means for
and the output of the electric control circuit, and controls the supply and discharge of hydraulic oil to the hydraulic servo I of the input and output pulleys, and controls the V-belt continuously variable transmission according to the vehicle running conditions. In a control device for a continuously variable automatic transmission for a vehicle, comprising a hydraulic control circuit including a reduction ratio control mechanism that changes a reduction ratio, the electric control circuit controls deceleration in the hydraulic control circuit when a brake activation signal is input. A reduction ratio control method for an automatic transmission for a vehicle, comprising causing a ratio control mechanism to start downshifting and downshifting to a reduction ratio corresponding to vehicle speed.