JPS59208255A - Controlling method of stepless speed change gear for vehicle - Google Patents

Abstract

PURPOSE:To operate engine brake appropriately, by a method wherein a change speed of a stepless speed change gear in a speed reduction period of time of a vehicle is established as a decrease function of a vehicle speed and at the same time during operation of a common use brake it is established at a value larger than the one to be obtained during nonoperation of the brake. CONSTITUTION:A change speed of a stepless speed change gear CVT4 in a speed reduction period of time of a vehicle is established as a decrease function of a vehicle speed and at the same time during operation of a common use brake it is established at a value larger than the one to be obtained during nonoperation of the brake. With this construction, as an engine brake acts upon weekly at the time of a high vehicle speed and nonoperation of a common use brake and acts upon strongly at the time of a low speed and operation of a common use brake, an appropriate engine brake corresponding to a driving state can be made to generate.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a 711 power transmission device used as a vehicle power transmission device.
[This article relates to a control method for a Danshami machine (hereinafter referred to as "CV Tj"), and more particularly to a method for controlling the speed change of a CVT.

The CVT can continuously control the appropriate ratio e (=output side rotational speed Nout/input side rotational speed Nin), and is used in vehicles as a power transmission device with excellent fuel consumption efficiency. In a conventional CVT, the shift speed e (absolute value 1dc/dtl of the value dc/dt obtained by differentiating the speed ratio C with respect to time t)
was set to a constant value regardless of the vehicle speed or the operation of the service brake. Therefore, the strength of the engine brake is almost constant regardless of the vehicle speed and the operation of the service brake, and there is a problem that it is too strong at high vehicle speeds and when the service brake is not activated, and too weak at low vehicle speeds and when the service brake is activated. .

The purpose of the present invention is to control vehicle speed and service brake operation.
It is an object of the present invention to provide a control method for a CVT that can operate an appropriate engine brake.

In order to achieve this object, the present invention sets the skin speed of the continuously variable transmission during the deceleration period of the vehicle as a decreasing function of the vehicle speed, and sets the skin speed to a larger value when the service brake is applied than when it is not applied. express

In the past, the engine brake was weak when the brakes for l:'d vehicle speed IL5 and 'i:g were not activated, and it was strong when the vehicle speed was low and when the service brake was activated. can be generated.

Middle school 4 i7) tli! A small function is defined as a discontinuous quantity or a continuous function that decreases stepwise or continuously as the medium oil \l increases. The station of the discontinuous function has the number of steps of the block and 0.1, self 1.・The advantage of being able to reduce the value of your data by 11, and in the case of a continuous function, it is possible to set the variable speed ratio 5 to a small value,',
There are 4.

Referring to the drawings, an embodiment of the present invention will be described.

Ru. A pair of input side disks 6a + 6b are provided facing each other, and the output side disk 6a of the input side is connected to the input side 11.
QI+ 5 is provided so as to be relatively movable in the axial direction, and the other input side disk 6b is fixed to input 4Ilb 5. Also, a pair of output side disks 7a.

71] is also pushed out opposite to the force, and the output side disk 7a of -F is fixed to the output shaft 8, and the other output side disk 7b is provided on the output shaft 8 so as to be movable in the axial direction. There is. The belt 9 has an isosceles trapezoidal cross section and is extended between the input side disks 6a', 6b and the output side disks 7d+7b.

The opposing surfaces of the input end disks 6a + 6b, and the output (
;11 The opposing surfaces of the disks 7a + 7b are formed into a tapered section IJ'l such that the distance between them increases by the distance [pal] as the force advances in the radial direction. The input side and output side disks 6a are related to increases and decreases in the distance between the opposing J.

The radius of engagement of the belt 9 at points 611.7a and 7b is reduced by Jj9, and the moderate ratio and transmission torque change.

The oil pump 14 sends oil sucked from the oil sump 15 to the pressure regulating valve 16. The linear solenoid pressure regulating valve 16 controls the oil flow to the train 17 (11) and controls the line B2 of the oil passage (8). The passage 18 of No. 41 is IK-connected to the hydraulic cylinder of the output side disc 7b. When increasing the linear solenoid inflow Fik control valve 19Ne), the i of the input side disk Lia to the hydraulic cylinder is
Flow between the road 20 and the oil road 18 [1r1j l
While increasing li, the connection between the oil passage 20 and the drain 17 (
Cut off the X gun, and reduce the push force between the input side disk (a + tib) to reduce the speed ratio to δ11.
In the station building, 49 +l, la of C Yamajiko 8 and 20 are 1
Distribution 1 ino between A11 road 20 and 1-ren 17 along with Ura?槓を：lr'J Jll to do. The rotation angle sensors 23 and 1 are the rotation angles of the input end disk 611 and the output side disk 7a, respectively.
7, the cylinder oil pressure of the output side disc 71), that is, the line pressure, is the minimum Mll that allows the heald 9 to reserve the torque transmission to 1.:゛) 1. :l: As a result, the driving loss of pump I4 is +l:lI 1
LiU will be done. Flow of words to the input side disk 6a: 1
The speed ratio of the CVT 4 is controlled by 1, and the cylinder curvature of the output side disk 7b ≧ the cylinder i'llll of the input side disk 6a. , and speed ratios of 1 or more are possible. The water temperature sensor 25 detects the temperature of the cooling water of the engine 1.

The throttle opening sensor 26 detects the opening of an intake system throttle valve that is linked to the accelerator pedal 27 .

The shift position sensor 28 is located at a shift lever near the seat 29.
Detects the range of The brake switch 30 detects depression of the brake pedal 31.

FIG. 2 shows a block IK of the electronic control device +'<ffi.

CPU 32, RAM 33.190M 34, I
/F (interface) 35, A/D (analog/digital converter) 36, and D/Δ (decile/analog converter) 37 are connected to each other by 4× bus 38. Rotation angle sensors 23, 24. Shift position: :S
The output pulses of the t sensor 28 and the brake switch 30 are sent to the interface 35, and the analog outputs of the water temperature sensor 25 and throttle i power sensor 26 are sent to the A/D
36, and the output of the D/A 37 is sent to the pressure regulating valve 16 and the flow Ijk control valve 19.

FIG. 3 is a control block diagram of the CVT 4.

In block 44, from throttle opening 0 to CVT 4
The target a (αNin') of the input side rotational speed N1n (engine rotational speed Nc) is reduced.In CVT 4, the required horsepower of the engine qA+ is set as a function of the throttle mountain opening 0, and The engine rotational speed Nc that achieves the desired horsepower at the minimum fuel consumption of 11 is used as the target value Nin' of the input rotational speed at the throttle opening of 0 at that time.In block 46, Nin is changed to Nin'. Follow the goal 1 until
Learn the y ratio e' by ΔC. However, change: I) Δe is positive 4H. The initial value of the apparent speed ratio (・′ is the actual speed ratio e, 80 is where 5i=j, l, and Ni
If n <Nin',-ΔeXNi11> N i
+Δe is selected for each lifting platform of i'.

Then, the feedback gain S1 is calculated from fiiRm of the actual Mutsumi ratio C with respect to the target speed ratio C'. Feedback gain flow J production 1 amplifier 5
0 to the flow-1 control valve 19, c v 'ra
The speed ratio C of is controlled. In block 52, the shaft torque Te of the engine 1 is calculated from the input side rotational speed Nin and the throttle III degree 0. Block 54 calculates line pressure as a function of CVT 4 transmitted torque. CVT
The transmitted torque of No. 4 is a function of the shaft torque Te of the engine J, the input side rotational speed Nin, and the output side rotational speed Nout. The output of the block 54 is sent to the pressure regulating valve 16 via the pressure regulating valve amplifier 56, and the line pressure of the CVT 4 is controlled.

FIG. 21 is a flowchart 1- of a routine that executes control according to the side cloth 1 block diagram of FIG. 3. The outline of the control is as already explained in Figure 3. Note that the upper and lower limits of the target speed ratio e' are emax and emi
n, and the flow I11 as the input voltage of one meteor control valve.
The control voltage is K(e'-e) (K is a constant),
The pressure regulating valve control voltage as the input voltage of the pressure regulating valve 16 is g(T
e+Nin.

Nout). In steps 60, 62, and 64, the throttle opening degree 0, the input side rotation speed Nin, and the output side rotation dKNout are read, and in step 66, the target input side rotation speed Nin' is calculated. In step 68, Nin and Nin' are compared, and if Nin = Nin', C' is held in step 70, and Nin<N.
If in', e' is decreased by Δcl in step 72, and if Nin >Nin', step 768
Then, (・' is increased by △e. Steps 73, 7
In step 4, we limit the lower bound of e' to em i n, and in step 7
At 8°80, the two limits of e' are restricted to cmax. Step 82 subtracts the flow I11 control voltage, step 84 calculates the engine shaft torque l'c, and then step 80 subtracts the H1r4 pressure valve control voltage by +1.

FIG. 5 shows the flowchart A1 of the routine for changing the speed change speed a, specifically, from step 46o5 in FIG. 31 to step 72 and 76 in FIG.
-1-. Note that the speed ratio & is completely redundant, but the speed ratio e is differentiated with time and the absolute value of the value dC/dt is 1.
dc/d1. There is one out of this routine.
The length δ is set in stages according to the medium V and the service brake A'15. Figure 7 shows the heavy speed V and service brake operating state I1 in this routine. ”, (
When the 'r13 brake is in operation, it is defined as brake main, and when it is not in operation, it is defined as brake off. ) and the shift speed δ. As a result, the larger the heavy speed V is, the smaller the shift speed δ is set, and when the brake is on, the shift speed δ is set to a larger value than when the brake is off. It operates strongly at vehicle speed and when the brake is on (+Q+) and weakly at vehicle speed and when the brake is off, and can generate good engine braking according to the vehicle speed and the operating state of the service brake. 1j, the shift speed is set to a small value a. To explain each step in FIG. If the idle switch is on continuously for Y time 1" or more, it is determined that it is a deceleration period for 141 cars and the process goes to step 92. If not, it is a non-deceleration period. If you do not understand this, proceed to step 100.Step 9
In step 2, the speed change moderation subroutine shown in FIG. 6 is executed. Step 94 determines whether the service brake is on or off;
If it is turned on, the process proceeds to step 9, and if it is off, the process proceeds to step 98. In steps 96, 98, and 100, y-6, e, and a are respectively substituted for the conversion speed. However, y
>I. In subroutine 8 of FIG. 6, step 110 't:' is r1g speed v(=(-Nout.

However, C is 1 number) and the predetermined value Vl are compared, ■≧\11
If so, the process proceeds to step 118, and if V<Vl, the process proceeds to step 112. In step 112, the vehicle speed V is compared with a predetermined value V2 (where V2<Vl), and ■-2V2
If so, the process proceeds to step 116; Step l1ll, If(i,
At +18, C1b and a are set to C1b and a (however, C2>b>a) at the variable iJm degree of 5, respectively.

FIG. 8 is a flowchart of another frugal tracing routine. In this H1 calculation routine, the quick speed is defined as a continuous function f (V) of the short distance V. Steps 120, 122 are executed instead of step 92 in FIG. In step 120, V and Vl are compared, and if ■≧■1, go to step 100; if V<Vl, go to step 1.
22, and in step 122, the shift speed is changed to f (V
). Figure 9 shows f (V) and y4 (V).

By setting a continuous function, the value of the shift speed d can be made more appropriate.

[Brief explanation of the drawing]

FIG. 1 is an overall schematic diagram of a CVT to which the present invention is applied, FIG. 2 is a block diagram of an electronic control device, and FIG. 3 is a CVT to which the present invention is applied.
FIG. 4 is a flowchart of the CVT control routine according to the control block diagram of FIG. 3, and FIG.
The figure is a flowchart of the shift speed calculation routine, FIG. 6 is a flowchart of the subroutine used in the routine of FIG. FIG. 8 is a flowchart of another shift speed subtraction routine, and FIG. 9 is a graph showing the relationship between the IL speed and the operating state of the service brake and the shift speed in the routine of FIG. 4...CVT, +9...Flow rate control valve, 24...Output side rotation angle sensor, 26...Throttle 1111 degree sensor, 30...Brake switch. Special 7F Applicant: Toyota Motor Corporation LIZ Co., Ltd. Figure 5 Figure 6 Figure 8 Figure 9 ■1 Vehicle speed V

Claims (1)

[Claims] 1. ``The force 1 during the deceleration period of the 41 cars (the shift curvature of the gear transmission is set as a decreasing function of the middle speed and
The i:lt dual-use f! is characterized by setting the river brake to a larger value when it is in operation than when it is not in operation. ((Danku Muji's starvation control method. 2. The range number of the special tjl' 1. The control method according to claim 1. 11. The apportionment method according to claim 1, characterized in that it is determined as a continuous function of 3 1ji + decreasing function or 1.