JPS60256663A - Stepless speed change gear controlling device for car - Google Patents

Abstract

PURPOSE:To control a line pressure to be a proper value corresponding to the actual output of an engine, without increasing the number of parameters to be detected. CONSTITUTION:First, engine speed Ne, intake air throttle opening theta, and engine cooling water temp. Tw are read (step 80). Next, the cooling water temp. Tw is compared with a defined value Tw1 to judge whether the warming up of engine is still under way or completed (step 82) and, if it is completed (Tw>=Tw1), a reference value Pinx is calculated from the Ne and theta, while an intake air negative pressure Pin is read. If the warming up is under way, a table A1 is designated, while if it has been completed with Pin>=Pinx, a table A2 is designated, whereas, with Pin<Pinx, a table A3 is designated. And, based on the designated table, an output torque Te, a speed ratio (e), and a line pressure Pl are calculated, and a controlling voltage Vc for a pressure regulating valve 32 is calculated.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a control device for a continuously variable transmission (hereinafter referred to as "CVT J") used as a power transmission device for a vehicle.
In particular, it relates to a CVT line pressure control device.

In the conventional C'VT, engine power is transmitted via a belt that is hung between an input pulley and an output pulley, and the line pressure of the hydraulic cylinder of one of the pulleys, usually the output pulley, is used to transmit the engine power to the output side boot. The pressing force on the belt is controlled. If this pressing force is small, the belt will slip on the pulley and torque cannot be transmitted, and if it is large, heat loss due to expansion and contraction of the belt and driving loss of the oil pump will increase, resulting in a worsening of fuel consumption. Therefore, it is desired that the line pressure be appropriately controlled according to the engine's output torque or transmission torque. However, in the conventional technology, the engine output torque, which is the basis for calculating the line pressure, is controlled based on the engine rotation speed and the intake throttle. It is calculated only from the opening degree (for example, Japanese Patent Application Laid-open No. 58-203259). However, since the output torque of the engine also changes depending on other operating parameters of the engine such as the air-fuel ratio of the air-fuel mixture, the line pressure is not currently controlled to a sufficiently appropriate value.

Therefore, in a separate application (Patent Application No. (2) dated June 1, 1980 filed by the applicant's agent), the applicant has filed a patent application for other operating parameters other than engine rotational speed and intake throttle opening, e.g. disclosed a control device that controls line pressure based on engine output torque calculated by taking into consideration whether exhaust gas recirculation is used and whether the engine is operating on all cylinders (or partial cylinder operation).

However, when there are many other operating parameters, each G
Based on this inspection Hr, and those G, the engine's output is 1.
Calculating the force torque &1 is complicated and the program ;1
'It also causes an increase in the number of steps in the ram.

Purpose An object of the present invention is to provide a CVT control device that can control line pressure to an appropriate value corresponding to the actual engine output without increasing the number of parameters to be detected. It is to be.

In order to achieve this object, according to the present invention, a belt is placed between the input pulley and the output pulley, and the engine power is transmitted through the belt, and the line pressure of the hydraulic cylinder of the L pulley is used to transmit the engine power. In a control device for a continuously variable transmission for a vehicle in which the pressing force of the belt by this pulley is controlled, either the first case is during warm-up, or the second case is when the intake pipe negative pressure is equal to or higher than the reference value after warm-up. and a third case in which the intake pipe negative pressure is less than the reference value after the end of warm-up. The engine includes a calculating means for calculating the output torque of the engine from the engine speed or the amount of intake air per unit rotation of the engine, and an adjusting means for adjusting the line pressure in relation to the calculated value of the calculating means.

EffectThe intake manifold vacuum affects the output torque of the engine, as during exhaust gas recirculation or during periods of partial cylinder operation, such as two-cylinder operation in a four-cylinder internal combustion engine, the intake manifold vacuum decreases. is closely related to the failure of given parameters. In the present invention, by representatively detecting the intake pipe negative pressure, it is possible to eliminate the complexity of individually detecting these predetermined parameters.

In the present invention, not only the engine speed and the intake throttle opening (or the intake air ratio i; t per unit rotation of the engine), but also the engine warm-up condition and the intake pipe negative pressure are taken into account. Since the power per herk is calculated, the line pressure adjusted in relation to such a calculated value will be the appropriate value that correctly corresponds to the engine's actual power per herk, thus avoiding belt debris. At the same time, the fuel consumption rate can be reduced to the maximum.

Preferably, the reference value is set as a function of engine rotational speed and intake throttle opening.

Preferably, a table defining the output torque of the engine using the engine rotational speed and the intake throttle opening or the intake air amount per unit rotation of the engine as parameters is prepared for each of the J to third cases, and the calculation means Calculate the output torque of the engine based on the table specified according to the first to third cases, or use the engine rotation speed and intake throttle opening or intake air amount per unit rotation of the engine as parameters. A table defining the basic output torque of the engine is prepared, and the calculating means calculates the output torque of the engine from the product of the basic output torque and the coefficient set according to the first to third cases.

Example ”　7□□, -C’$1□.A□.Eng.

In Fig. 1, CVT io is an input shaft 1 parallel to each other.
2 and an output shaft 14. The input shaft I2 is provided coaxially with the crankshaft 18 of the engine 16, and is connected to the crankshaft 18 via the clutch 2o. The input pulleys 22a'+2211 are provided opposite to each other,
One input-side pulley 22a is provided on the input shaft 12 as a movable pulley so as to be movable in the axial direction and fixed in the rotational direction, and the other input-side pulley 22b is fixed to the input shaft 12 as a fixed pulley. Similarly, the pulley 24 on the exit side
a and 24b are also provided facing each other, one of the output side pulleys 24a is fixed to the output side @14 as a fixed pulley, and the other 8-side pulley 24b is a movable pulley that is movable in the axial direction and rotated in the rotational direction. It is fixedly mounted on the pressure shaft 14. Opposing surfaces of the far side pulleys 22a, 22b and the output side pulleys 24a, 24b are formed in a tapered shape, and a melt (V heald) 26 with a uniform cross section is connected to the input side pulleys 22a, 22b and the output side pulley 24a. ,2
It is hung between 4b. The oil pump 28 sends oil 5 ·i' in the oil sump 3o 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.
b is sent to the hydraulic cylinder and flow control valve 38. The flow control valve 38 controls the flow rate of oil supplied from the oil passage 36 to the oil passage 40 connected to the hydraulic cylinder of the input pulley 22a, and the flow rate of oil discharged from the oil passage 40 to the drain 34. Input side pulley 2 for belt 26
The pressing forces of the input pulleys 2a, 22b and the output pulleys 24a, 24b are controlled by the oil pressure of the input hydraulic cylinder and the output hydraulic cylinder, and the input pulleys 22a, 22b and the output pulley 24a are controlled in relation to this pressing force.

The radius of engagement of the belt 26 on the tapered surface of the belt 24b changes, and as a result, the CVTIO speed ratio e (=Nout/N
in, where Nout is the rotational speed of the output shaft 14, Ni
n is the rotational speed of the input shaft 12, and in this case, c2
Yo, collar pickle, yo, fast, 8□Ah. )Ka, Kai.

do. In order to suppress drive loss of the oil pump 28, the line pressure of the output side hydraulic cylinder is controlled to the minimum necessary value that can avoid slipping of the belt 26 and ensure power transmission, and is controlled by the oil pressure of the input side hydraulic cylinder. The speed ratio e is controlled. Note that the hydraulic pressure of the input side hydraulic cylinder is the hydraulic pressure of the output side hydraulic cylinder, but the pressure receiving area of the input side hydraulic cylinder is
Since this is the pressure receiving area of the output side hydraulic cylinder, the pressing force of the input side pulleys 22a and 22b is expressed as the output side pulley 24a,
It can be made larger than the pressing force of 24b. The input side rotation angle sensor 42 and the output side rotation angle sensor 44 correspond to the rotation speed Nin+No of the input shaft 12 and the output shaft 14, respectively.
ut is detected, and the water temperature sensor 46 detects the cooling water temperature of the engine 16. The driver's seat 48 is provided with an accelerator pedal 5o, and the throttle valve in the intake passage is provided with an accelerator pedal 5o.
The throttle opening sensor 52 is linked to the throttle opening 17.
Detects 11 degrees O. A shift position sensor 54 detects the shift range of a shift lever located near the driver's seat.

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

7 Tre 7, -F 9 Lotus 56 HaCPt+ 58.
RAM60. ROM62.17P (interface)
-64, A/D (analog/digital converter) 66
, and a D/A (digital/analog converter) 68 are interconnected. 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 ÷ intake air flow rate. It receives analog signals from the air flow meter 70 that detects the
A68 outputs a pulse signal to the pressure regulating valve 32 and the flow rate control valve 38.

FIG. 3 is a flowchart of the line pressure control routine. Before explaining the routine in FIG.
FIGS. 11 to 11 will be explained. Figures 4 to 6 show the engine rotation speed Ne using the intake throttle opening θ as a parameter.
(=Nin) and the engine output torque Te.

Figure 4 shows the relationship during warm-up, where the output torque Te is low due to the viscosity of the engine oil and fuel efficiency. FIG. 5 shows the relationship during the period when the intake pipe negative pressure is high after the end of warm-up, and FIG. 6 shows the relationship during the period when the intake pipe negative pressure is low after the end of warm-up. During periods when two cylinders are operating in a four-cylinder internal combustion engine or when exhaust gas recirculation is being performed, the intake pipe negative pressure decreases, and
The output torque Te of the engine also decreases. The data of the engine output torque Te as defined in FIGS. 4 to 6 are shown in Table A1. A2. It is stored in RoM62 as A3. Figures 7 to 9 show the amount of intake air per unit rotation of the engine. /Ne (where Q is the intake air flow rate and Ne is the engine rotational speed), and shows the relationship between the engine rotational speed Ne and the engine output torque Te using Q/Ne as a parameter. As in the case of Figures 4 to 6, Figure 7 is during warm-up, Figure 8 is during the period when the intake pipe negative pressure is high after warm-up, and Figure 9 is during the period when the intake pipe negative pressure is high.
The diagram is IIIJJ! ! The relationship between the periods during which the intake pipe negative pressure is high after the end is shown.

Instead of the relationships shown in FIGS. 4 to 6, the relationships shown in FIGS. 7 to 9 may be used as the tables A1 to A3.

Note that wOT means maximum throttle opening. FIG. 1O shows the relationship between the line pressure Pl and the control voltage Vc of the pressure regulating valve 32. Pl and Vc have a linear relationship. FIG. 11 shows the relationship between the engine rotational speed Ne and the reference value Pinx of the intake pipe negative pressure Pin, using the intake throttle opening θ as a parameter. In the case of partial cylinder operation such as two-cylinder operation in a four-cylinder internal combustion engine, and when exhaust gas recirculation is implemented, the intake pipe negative pressure P1n becomes less than the reference value Pinx. In FIG. 11, the reference value Pinx may be set using Q/Ne, which corresponds to θ, as a parameter instead of the intake throttle opening degree 0.

The routine of FIG. 3 will be explained in detail.

First, the engine rotational speed Ne, intake throttle opening degree 01, and engine cooling water temperature Tw are read (step 80). Instead of the intake throttle opening degree of 0, Q/Ne as the intake air Mk per engine rotation may be read. Next, the cooling water temperature 'rw is compared with a predetermined value Twl to determine whether the engine is warming up or after warming up (step 82). If after warming up (Tw≧Twl), Ne and θ (or Q/
Ne), the reference value Pinx is calculated from (step 84), and the intake pipe negative pressure Pin is read (step 86).
), compare Pin and Pinx (step 88)
.

As mentioned above, during partial cylinder operation and when exhaust gas recirculation is in effect, Pin < Pinx.

Finally, table AI is specified during warm-up (step 90), and table A2 is specified if Pin 2 Pinx after warm-up is completed (step 92), and if Pin < Pinx after warm-up is completed, table A2 is specified (step 92). Table A3 is designated (step 94).

Next, the output l·lux Te is calculated based on the specified table (step 96), and the speed ratio e (-h·out / Nz+) of the CVT 10 is calculated as TXt13 saf.
L (step 5-imp 98), line pressure Pl! 1. +)P
It is calculated from i=f −Te−+/e (step 100). The force f is a coefficient, and Te·l/e corresponds to 1-lux at the output pulleys 24a and 24b of CV1'IQ. Based on the graph in Figure 10, P
7! The control wJ'WL pressure Vc of the pressure regulating valve 32 is calculated from the calculated value (step 102), and this Vc is output to the pressure regulating valve 32 (step 104).

FIG. 12 shows another embodiment of the line pressure control routine. To explain only the parts that are different from the routine in FIG. 3, steps 90b, 92b, 94
In b, the coefficient K is respectively Ka + K b +
K c is substituted, and in step 96b -Tea is set as the calculated value of the output torque Te to the product of K and the basic torque Tea. The basic torque Tea is set as the relationship between %e and θ (or Q/Ne), and Ka+Kb+Kc
is set as a correction coefficient for the period during warm-up, when Pin ≥ Pin The value is close to the output torque of

Although the present invention has been described with reference to the embodiments shown in the drawings, it will be obvious to those skilled in the art that various modifications and variations can be made without departing from the spirit of the present invention as set forth in the claims.

[Brief explanation of drawings]

Figure 1 is a schematic diagram of the entire CVT, Figure 2 is a block diagram of the electronic control unit, Figure 3 is a flowchart of the line pressure control routine, and Figures 4 to 9 are engine outputs in each operating state of the engine. A diagram showing the torque characteristics, Figure 10 is a graph showing the relationship between the control voltage of the pressure regulating valve and the line pressure, @11
The figure is a graph showing the characteristics of the reference value of the intake pipe negative pressure, and FIG. 12 is a flowchart of another line pressure control routine. 10--- CVT, 22a, 22b---Input end pulley, 24a, 24b... Output side pulley, 26...
Belt, 32... Pressure regulating valve, 42... Input side rotation angle sensor, 46... Water wetness sensor, 52... Throttle opening sensor, 58... CPU, 70... Air flow meter, 72 ...Negative pressure sensor. Patent Applicant: Toyota Motor Corporation Figure 1 0 hiku 90 and t+. FIG. 2 FIG. 4 Engine rotation speed Nθ FIG. 5 Engine rotation speed Ne FIG. 6 Engine rotation speed Ne FIG. 7 Engine rotation speed N0.1 FIG. 8 Engine rotation speed N. Figure 9 Engine rotation speed Na Line pressure pIl Intake throttle opening θ [chi]

Claims (1)

[Claims] 1. A belt is placed between the input pulley and the output pulley, and engine power is transmitted through the belt, and the line pressure of the hydraulic cylinder of one pulley causes the belt to be pushed by this pulley. In a control device for a continuously variable transmission for a vehicle, whether the first case is during warm-up, the second case when the intake pipe negative pressure is equal to or higher than the reference value after warm-up, and Judgment means for determining whether it is the third case where the intake pipe negative pressure is less than the reference value after the end, and the engine rotation speed and intake throttle opening or per unit rotation of the engine depending on each of the first to third cases. A continuously variable transmission for a vehicle, characterized by comprising a calculation means for calculating the output torque of the engine from the intake air amount, and an adjustment lever for adjusting the line pressure in relation to the calculated value of the calculation means. Control device. 2. Ma filling device 3 according to claim 1, wherein the reference value is set as a function of engine rotational speed and intake throttle opening 3. One pulley is an output pulley. A table is prepared for each of the first to third cases in which the output torque of the engine is defined using the first claim or the second intake air amount per unit rotation as a parameter, and the calculation means is the first to third table. or third
4. The control device according to any one of the patents to claim 3, wherein the control device calculates the output torque of the engine based on a table specified depending on the case. 5. A table is prepared in which the basic output torque of the engine is defined using the engine speed and the intake throttle opening or the amount of intake air per unit rotation of the engine as parameters, and the calculation means is set according to the first to third cases. 4. The control device according to claim 1, wherein the output torque of the engine is calculated from the product of the calculated coefficient and the basic output torque.