JPS60220252A - Controller of stepless speed changer for vehicle - Google Patents

Abstract

PURPOSE:To improve fuel consumption ratio and drive performance by correctly setting a target engine rotational speed as an optimum engine rotational speed. CONSTITUTION:A stepless speed changer CVT10 is provided with an input shaft 12 and an output shaft 14 which are parallel to each other. The input shaft 12 is concentrically provided with respect to a crankshaft 18, and is connected to the crank shaft 18 through a clutch 20. A target engine rotational speed is set depending on the throttle opening degree, car speed, shifting position, engine cooling water temperature and other driving parameters of the engine, and the CVT10 is controlled depending on the above described rotational speed and the transmission torque of the CVT10.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a continuously variable transmission used as a power transmission device for a vehicle.
7) Party B regarding control device Party B.

In the control devices of background technologies C to rT, the actual engine rotation i, 4i I
QN+・ becomes the target engine simultaneous rotation speed Nc' to JI (~
! 1 speed ratio e (e s Noun,'Nin, where N oul is the output lJ side rotational speed, and Nin is controlled by human power (1111 rotational speed 1).In the conventional control device, 11 The standard engine rotational speed Ne' is set in relation to the throttle opening, vehicle speed, upper I (drive) range, shift position such as 2nd (second L) range, etc., but may vary depending on other operating parameters of the engine. is pl (relationship and f, 1-') 1, target engine rotation speed Ne' is the optimum engine rotation speed that can achieve both fuel consumption 4 (and drivability) in each JYli rotation situation of the engine. Therefore, in the conventional control device, the sufficiently optimal engine rotation speed is [ ] standard engine rotation speed Ne
For example, there is a control that switches the air-fuel ratio of the mixture between the extensible air-fuel ratio and the lean air-fuel ratio depending on the engine's In the case of P!, when the engine rotational speed suitable for the stoichiometric air-fuel ratio is commonly used as "I standard engine 1i'i1 rotation degree N?", Therefore, since the accelerator pedal depression increases, the fuel consumption rate becomes worse than when the target engine rotational speed Ne' is set so as to generate output horsepower at a low throttle opening.

DETAILED DESCRIPTION OF THE INVENTION The object of the present invention is to provide a control device for a medium-duty CVT that can accurately set the standard engine rotation speed noise as an aid to the optimum engine rotation speed and improve fuel consumption rate and driving performance. It is to provide.

To achieve this objective, the vehicle CvT control device of the present invention provides a target engine rotation speed of the engine based on the throttle opening, medium speed, and other operating parameters of the engine other than the shift position and at least the throttle opening. Setting means for setting speed and target engine set by the setting means @
II! /, CV so that the speed matches the actual engine rotation speed.
It is equipped with a control means for controlling the speed ratio of T.

In this way, by reflecting other operating parameters of the engine other than the lever opening, medium speed, and shift position in the setting of the 11-standard engine speed J5Ne', the fuel Balancing consumption rate and driving performance,
The optimal engine rotational elongation fJ can be set as the target engine rotational speed Ne', and as a result, driving performance and fuel consumption rate can be improved.

Other operating parameters include engine cooling water level, set air-fuel ratio, implementation status of gas recirculation, number of cylinders in operation (full cylinder operation or partial cylinder operation), or intake pipe. Contains all operating parameters that affect engine operating performance.

Example The present invention will be described in detail with reference to the drawings.

In FIG. 1, a CVTI (l is 11") is provided with an input shaft 12 and an output shaft 14 which are parallel to each other. The input shaft] 2 is provided coaxially with respect to a crankshaft 18 of an engine 16, and a clutch 20 The input pulleys 22a and 22b are provided opposite to each other, and one of the input pulleys 22a is movable in the axis direction as +'iJ movement-!-. The other pulley 22b is fixed to the input shaft 12 as a fixed pulley.Similarly, the output pulleys 24a+24b are also provided on the input shaft 12 in a fixed manner in the direction of rotation. One output pulley 24a is fixed to the output shaft 14 as a fixed pulley, and the other output pulley 24a is fixed to the output shaft 14 as a fixed pulley.
4b is provided as a movable pulley at the output Ot++4 so as to be movable in the axial direction and fixed in the rotational direction. Input side pulley 22+1 + 22h and output side pulley 2
Opposing surfaces of the input pulleys 22a and 24b are tapered, and a belt 26 having an isosceles trapezoid cross section is hung between the input pulleys 22a and 22b and the output pulleys 24a and 24b.

The oil pump 28 sends oil from the oil sump 30 to the pressure regulating valve 32. The pressure regulating valve 32 is composed of an electromagnetic relief valve, and controls the line pressure of the oil passage 36 by changing the amount of oil released to the drain 34. The line pressure of the oil passage 36 is controlled by the hydraulic cylinder of the output pulley 2411 and the +yt control valve 3
Sent to 8. Diversion control valve;) 8 is input side pulley 22
Oil passage 3 to oil passage 40 connected to the hydraulic cylinder a
The oil supply flow 111 from the oil f140 and the oil discharge flow from the oil f140 to the drain 34 are controlled. belt 2
The pressing force of the input pulleys 22a + 22b and the output pulleys 24a, 24b with respect to 6 is controlled by the oil pressure of the input hydraulic cylinder and the output hydraulic cylinder, and in relation to this pressing force, the input pulleys 22a, 22b and the output pulley 24a , 24h taper second belt 26
The radius of contact becomes C, and as a result, the CVTIO speed ratio e (= Nout / Nin).

However, Nout is the same rotational speed of the output shaft 14, Nin is the rotational speed of the input shaft 12, and in this embodiment, Nin=engine rotational speed Ne. ) changes. In order to suppress the drive loss of the oil pump 28, the line IE of the output side hydraulic cylinder is controlled to the minimum necessary value that can avoid the belt 26 from collapsing and ensure power transmission, and the line IE of the input side hydraulic cylinder is l) The speed ratio e is controlled. Note that the hydraulic pressure of the input side hydraulic cylinder ≦ the hydraulic pressure of the slope side hydraulic cylinder, but since the pressure receiving area of the input side hydraulic cylinder > the pressure receiving area of the output side hydraulic cylinder, the pressing force of the input side pulleys 22a and 22b is expressed as It can be made larger than the pressing force of pulleys 24a and 24b. The input rotation angle sensor 42 and the output rotation angle sensor 44 detect the rotation speeds Nin+Nout of the input shaft I2 and the output shaft 14, respectively, and the water temperature sensor 46 and the degree sensor 52 detect the throttle opening degree θ.

A shift position 11 sensor 54 detects the shift range of a shift lever located near the driver's seat. Negative pressure sensor 70 detects intake pipe negative pressure.

FIG. 2 is a block diagram of the electronic control device.

7 Treste'3 Has56 HaCPU 58. R.A.
M60. ROM62.1/F (interface) 6
d, A/D (Anna "Jgu/Digital slimming device)" 661
and a D/A (digital/analog C converter) 68 are connected to the phase y1-. The I/F 64 receives pulse signals from the input side rotation angle sensor 42, the output side rotation angle sensor 44, and the shift position sensor 54, and the A/D 66 receives pulse signals from the water temperature sensor 46, throttle opening sensor 52, and negative Upon receiving the analog signal from the pressure sensor 70, the D/A 68 outputs a pulse signal to the pressure regulating valve 32 and the flow rate control valve 38.

The 31121st is the flag of the CVTIO (7) control routine.
-It is a chart. Target engine speed Ne' is set in relation to throttle opening degree 0, medium speed v1 shift position, engine cooling water temperature Tw, and other operating parameters of the engine (for example, set air-fuel ratio, execution status of exhaust gas recirculation). is,
CVTlO is controlled in relation to the target engine speed Ne' and the transmission torque of the CVT 10. To explain each step, in step 76, the throttle opening degree 0 and the vehicle speed V are read. In steps 78, 80, and 82.84, it is determined whether the D range is selected, whether the engine cooling water temperature Tw is high or low, and what values other operating parameters of the engine are at. Then, the process proceeds to steps 86, 88, 90, and 92.9+1, respectively. Other operating parameters in step 82 include the lean signal (set air-fuel ratio) determined in the routine of FIG. 10, or the operating conditions determined in the routine of FIG. partial cylinder operation) is used. In steps 86 to 94, tables) to 5 are designated, respectively.

4 to 8 show the characteristics of the target engine rotational speed Ne' (at steady state) set in Tables 1 to 5, respectively. Table I in FIG. 4 is selected during warm-up of the D range, so the target engine speed Ne' is set to a slightly higher value in the low throttle opening range, and Il
The margin torque (the amount of torque that can be increased in proportion to the throttle opening during acceleration) has been increased to ensure operational performance due to the increased friction of the previous model. Table 2 in FIG. 5 is selected in the D range, after warm-up, and, for example, during the stoichiometric air-fuel ratio control period, and the target engine rotation speed Ne' is set so that the engine output torque becomes lJO>L and a predetermined margin]
- The system is set to ensure that the Table 3 in FIG. 6 is selected in the D range, after warm-up, and during, for example, the control period of the low air-fuel ratio, and the target engine rotational speed Ne' is set with emphasis on the fuel consumption rate. Table 4 in Figure 7
is selected in the 2nd range, and the target engine rotational speed Ne' is set with emphasis on acceleration performance. Table 5 in FIG. 8 is selected in the N (courtral) range and the R (reverse) range, and the target engine rotational speed Ne' is the CVT I
The speed ratio e of n is set to be the minimum. At step 96, a target engine rotational speed Ne' is calculated based on the table designated at any one of steps 86-94. In step 98, a bending speed control routine is executed.

FIG. 9 shows flowchart 1 of the speed change control routine.

Output side rotational speed Nout/target engine target engine degree Ne' is calculated by 1 [calculating the target speed ratio e', and the flow control + control a of the II valve 38 is applied so that the actual speed ratio e becomes the target speed ratio e'.
Calculate the voltage Va. In addition, the output torque 1e of the engine is calculated as a function of the throttle opening degree 0, etc., and the control voltage vb of the pressure regulating valve 32 is calculated as Te+input side rotational speed Nin, and t
11 as a function of the force side rotational speed Nout, that is, as a function of the torque of the output side pulleys 24a and 24h. To explain each step, in step 104, the output side rotation speed No+input and the input side rotation speed Nin are read. In step +06, the actual speed ratio e of CVT 10 is No.
Substitute ut/Nin. In step +08, Nouj/Ne' is substituted for the target speed ratio e'. In step +10-116, the two limits and the lower limit of the target speed ratio e' are limited to emax and emin, respectively. In step 118, e'-e is substituted for the deviation Δe. At step +20, the control voltage Va of the flow rate control valve 38 is set to Kl-e-.
Substitute 2・Δe for . However, Kl and 2 are constants. In step 122, the engine output torque Te is calculated from the throttle opening θ. In step 124, the pressure regulating valve 3
2 system? aThe voltage Vb is Te, the function f of Nin+NouL
(Te+Nin+N0ul). Step 12
6(11) outputs Va and Vb.

As a result of starvation, as shown in No. 11, the air-fuel ratio A/F is the basic value of the fuel. It is switched in relation to the injection amount 'rp, and the switching from the stoichiometric air-fuel ratio to the lean air-fuel ratio l\ is performed when 'rp is Tp2.
The switching from the lean side air-fuel ratio to the stoichiometric air-fuel ratio is carried out when rp becomes 7 or above, and when Tp becomes less than 1.
This is performed when the value becomes less than 91 and when rp becomes `rp4 or more.

When the air-fuel ratio A/F is limited to the lean side, a lean signal is set, and when the throttle opening degree 0 is greater than the predetermined value 01, and the air-fuel ratio A/F is
1j If the air-fuel ratio is controlled to the stoichiometric air-fuel ratio, the back-on signal is reset. Note that when the engine cooling water temperature rw is not equal to the predetermined value Twl, the A/F is the pH stoichiometric specific fuel ratio. Wart 11 (of the lean signal) is used as the value of the operating parameter of the lock in step 82 of the figure.Furthermore, flag F is used to generate hysteresis, and A/
(12) is set when the air-fuel ratio is switched from the stoichiometric air-fuel ratio to the lean air-fuel ratio.

Step 130
Then, the intake air flow ff1Q and the engine rotation speed Ne.

Read the throttle opening θ and the engine cooling water temperature Tw. In step +32, the basic injection amount Tp is calculated as a function of Q/Ne. In step 134, 0 and the predetermined value OI
If o>θ1, that is, if the throttle opening is high, the process advances to step 156 and θ≦01.
If so, proceed to step 136. In step +36, Tw is compared with a predetermined value Tw+, and if TV < TWI, that is, if the TV is being warmed up, the process proceeds to step 158.
If Tw≧]w1, the process advances to step +38. In steps 138 to +54, as shown in No. 1111, it is determined which region the basic injection @Tp is in;
In relation to this judgment result, step 158 or +62
Proceed to. Step! At 56, 'rp is corrected by increasing the power to obtain the power air-fuel ratio. In step 158, Tp(13) is corrected by feedback correction to obtain the stoichiometric air-fuel ratio. STETSU! At 160, the lean signal is reset. In step 162, Tp is lean-corrected to obtain a lean air-fuel ratio.

In step 164, the lean signal is set to Sera1.

Figure 12 shows the engine operating power meter X from the absorption pipe negative pressure Pa.
This is the routine step for setting the value of .

Exhaust gas recirculation or partial cylinder operation (e.g. dual cylinder operation in a 4α internal combustion engine)
During the period in which the intake pipe negative pressure Pa decreases,
X=Xl, and during the non-implementation period, it becomes X-X2. To describe each step, in step 170, the engine rotation speed N
Read e, thrower 1 heel opening degree 0, and intake pipe f3 pressure Pa. In step 172, a reference negative pressure Pal is calculated based on Ne and θ. Figure 13 shows Np.

0 and the reference 0 pressure Pal. When [J torque opening degree O is small, and engine [1j1 rotation speed N
The larger e is, the greater the intake pipe negative pressure Pa when exhaust gas internal circulation or partial cylinder operation is not performed.
The reference negative pressure Pa1 also increases l 14 ). In step 174, Pa and Pal are compared, and Pa
< If Pal, set X to Xl in step 176.
If Pa>Pal, then in step +78, X2 is substituted for X.

[Brief explanation of the drawing]

1 II is an overview of the entire CVT (7) in Figures 11&'5, and 2
Figure 3 is a flowchart of the CVT control routine, Figures 4 to 8 are graphs defining the target engine speed under each operating condition, FIG. 9 is a flowchart of the CVr speed change control routine, FIG. 10 is a flowchart of the fuel injection amount control routine, FIG. 11 is a graph showing the relationship between the basic injection amount and the set air-fuel ratio in the 101m routine, and FIG. This figure is a flowchart of a routine for setting values of operating parameters, and FIG. 13 is a diagram showing the reference pressure calculated in the routine of FIG. 12 as a function of engine rotational speed and throttle opening. lO...CVT, 38...Flow rate control valve, 42...
Input side rotation angle sensor, 44... Output side rotation angle sensor (15
) Sensor, 716...Water wetness sensor, 52...S [J-turn opening sensor, 54...Shift position sensor, 70...
・Negative pressure sensor. (16) Throttle opening θ Figure 5 Throttle opening θ Figure 6 Throttle opening θ Figure 7 Throttle opening θ Tpl Tp2 Tp3 Tp4 Basic injection amount Tp

Claims (1)

[Scope of Claims] 1. A setting means for setting a target engine rotational speed of an engine based on at least the throttle opening and other operating parameters of the engine other than the throttle opening, vehicle speed, and shift position, and setting by the setting means. characterized by comprising a control means for controlling the speed ratio of the continuously variable transmission so that the actual engine rotation speed becomes equal to the set target engine rotation speed,
Control device for continuously variable transmission for vehicles. 2. Claim 1, characterized in that the other operating parameters are the engine cooling water temperature, the set air-fuel ratio, the implementation status of exhaust gas recirculation, the number of operated cylinders, or the intake pipe negative pressure. Control device as described.