Control for vehicle provided with continuously variable speed system power transmission

• US 4,546,673 A
• Filed: 08/01/1983
• Issued: 10/15/1985
• Est. Priority Date: 08/04/1982
• Status: Expired due to Term

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Watanabe, Tomoyuki, Shigematsu, Takashi
• Primary Examiner(s): Braun, Leslie A.
• Assistant Examiner(s): Diehl, Dwight G.
• Application Number:
  US06/519,149
• Time in Patent Office: 806 Days
• Field of Search: 74/689, 74/856, 74/857, 74/858, 74/859, 74/862, 74/864, 74/865, 74/866
• US Class Current: 477/48
• CPC Class Codes: B60W 10/04 including control of propulsion units
• CPC Class Codes: B60W 10/06 including control of combustion engines
• CPC Class Codes: B60W 10/101 Infinitely variable gearings
• CPC Class Codes: B60W 30/1819 Propulsion control with control means using analogue circuits, relays or mechanical links
• CPC Class Codes: B60W 30/1882 characterised by the working point of the engine, e.g. by using engine output chart
• CPC Class Codes: F16H 61/66 specially adapted for continuously variable gearings control of exclusively fluid gearing F16H61/38
• CPC Class Codes: Y10S 477/905 Acceleration of throttle signal

Abstract

According to this invention the driver'"'"'s will to accelerate and decelerate is detected by a pressing amount of an accelerator pedal, or the like. Speed ratio of a continuously variable speed transmission and air-fuel ratio of air mixture in a combustion chamber of an engine are controlled according to that will. As a result, a WOT (Wide Open Throttle) period in which the vehicle travels with the optimum rate of fuel comsumption becomes longer, and an appropriate responsive property in acceleration and the maximum output horse power of an engine is ensured.

Claims

1. A control for a vehicle provided with:

(a) a continuously variable speed system power transmission which utilizes a continuously variable transmission comprising;

(i) a belt trained over a plurality of disks, at least one of said plurality of disks being movable to control the speed of the belt, and

(ii) a pressing force controlling means for controlling the force with which the belt presses against said disks in relation to acceleration fuel increments;

(b) an engine having a combustion chamber, said engine being operatively connected to said continuously variable transmission;

(c) a fuel injector operatively connected to said engine;

(d) an accelerator pedal operatively connected to said engine to control engine speed;

(e) an air-flow rate detecting means operatively connected to said fuel injector;

(f) a line pressure generating valve;

(g) a hydraulic pressure means operatively connected to said line pressure generating valve;

(h) a flow controlling valve operatively connected to said line pressure generating valve and to said pressing force controlling means;

(i) an electronic control unit having inputs from said engine and from said air-flow rate detecting means and outputs to said fuel injector, said flow controlling valve, and said line pressure generating valve;

(j) a torque sensor operatively connected to said engine and having an input to said electronic control unit;

(k) a rate of acceleration detecting means operatively connected to said accelerator pedal and having an input to said electronic control unit;

(l) a first angle sensor operatively connected to a first one of said plurality of disks mounted on a first shaft and having an input to said electronic control unit; and

(m) a second angle sensor operatively connected to a second one of said plurality of disks mounted on a second shaft and having an input to said electronic control unit,

said control comprising;

(n) a detecting means for detecting acceleration and deceleration intended by a driver;

(o) a computation means for figuring out desired air-fuel ratios in said combustion chamber and the desired speed ratios of said continuously variable transmission in relation to the output of said detecting means;

(p) a speed ratio controlling means for controlling the speed ratio of said continuously variable transmission such that the speed ratio of the continuously variable transmission becomes the desired speed ratio; and

(q) an air-fuel ratio controlling means for controlling the air-fuel ratio such that the air-fuel ratio in the combustion chamber becomes the desired air-fuel ratio, the air-fuel ratio being lowered together with the speed ratio of said continuously variable transmission during transient periods in which the input side rotational speed of said engine (Nin) does not equal the desired input side rotational speed of said engine (Nin*), the amount by which the air-fuel ratio is lowered being a function of the rotational speed of the engine.

2. A control as recited in claim 1 wherein said at least one of said plurality of disks which is movable to control the speed of the belt is the output side disk of the continuously variable transmission and it is moved by means of a hydraulic cylinder, said pressing force controlling means being adapted to control line pressure sent to said hydraulic cylinder.

3. A control for a vehicle provided with;

(a) a continuously variable speed system power transmission which utilizes a continously variable transmission comprising;

(i) a belt trained over a plurality of disks, at least one of said plurality of disks being movable to control the speed of the belt, and

(ii) a pressing force controlling means for controlling the force with which the belt presses against said disks in relation to acceleration fuel increments;

(b) an engine having a combustion chamber, said engine being operatively connected to said continuously variable transmission;

(c) a fuel injector operatively connected to said engine;

(d) an accelerator pedal operatively connected to said engine to control engine speed;

(e) an air-flow rate detecting means operatively connected to said fuel injector;

(f) a line pressure generating valve;

(g) a hydraulic pressure means operatively connected to said line pressure generating valve;

(h) a flow controlling valve operatively connected to said line pressure generating valve and to said pressing force controlling means;

(i) an electronic control unit having inputs from said engine and from said air-flow rate detecting means and outputs to said fuel injector, said flow controlling valve, and said line pressure generating valve;

(j) a torque sensor operatively connected to said engine and having an input to said electronic control unit;

(k) a rate of acceleration detecting means operatively connected to said accelerator pedal and having an input to said electronic control unit;

(l) a first angle sensor operatively connected to a first one of said plurality of disks mounted on a first shaft and having an input to said electronic control unit; and

(m) a second angle sensor operatively connected to a second one of said plurality of disks mounted on a second shaft and having an input to said electronic control unit,

said control comprising;

(n) a detecting means for detecting acceleration and deceleration intended by a driver;

(o) a computation means for figuring out desired air-fuel ratios in said combustion chamber and the desired speed ratios of said continuously variable transmission in relation to the output of said detecting means;

(p) a speed ratio controlling means for controlling the speed ratio of said continuously variable transmission such that the speed ratio of the continuously variable transmission becomes the desired speed ratio; and

(q) an air-fuel ratio controlling means for controlling the air-fuel ratio such that the air-fuel ratio in the combustion chamber becomes the desired air-fuel ratio, the air-fuel ratio being lowered together with the speed ratio of said continuously variable transmission during transient periods in which the input side rotational speed of said engine (Nin) does not equal the desired input side rotational speed of said engine (Nin*), the amount by which the air-fuel ratio is lowered being a function of the amount by which said accelerator pedal is pressed.

4. A control as recited in claim 3 wherein said at least one of said plurality of disks which is movable to control the speed of the belt is the output side disk of the continuously variable transmission and it is moved by means of a hydraulic cylinder, said pressing force controlling means being adapted to control line pressure sent to said hydraulic cylinder.