IP Library Granted Patent US 8,478,495
Granted Patent B2
US 8,478,495 · App. 13/064,088 · Granted Jul 2, 2013

Shift control device for continuously variable transmission

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Quick Facts
Patent No.
US 8,478,495
App. No.
13/064,088
Granted
Jul 2, 2013
Kind
B2
Abstract

A requested cruise-control horsepower calculator obtains a requested cruise-control horsepower from a speed difference between a target cruising vehicle speed and an actual vehicle speed. A requested cruise-control torque calculator obtains a requested cruise-control torque on the basis of the requested cruise-control horsepower and an engine rotation speed. A cruise-control accelerator-opening calculator sets a cruise-control accelerator opening by referring to an engine torque map in which a cruise-control accelerator-opening characteristic curve is set along an equal horsepower line on the basis of the requested cruise-control torque and the engine rotation speed. A target primary rotation-speed calculator sets a target primary rotation speed by referring to a shift-line map on the basis of the cruise-control accelerator opening and the actual vehicle speed. A shift controller obtains a target gear shift ratio on the basis of the target primary rotation speed and the actual vehicle speed so as to perform shift control.

Claims (24)

1. A shift control device, implemented on a computer processor, for a continuously variable transmission, the shift control device comprising:

requested power calculating means that obtains a requested power, for making an actual vehicle speed reach a target vehicle speed set during a cruise control, on a basis of a speed difference between the target vehicle speed and the actual vehicle speed;

requested torque calculating means that obtains a requested torque on a basis of the requested power and an engine rotation speed;

accelerator-opening calculating means that obtains a cruise-control accelerator opening on a basis of the requested torque and the engine rotation speed; and

shift controlling means that performs shift control by setting a target gear shift ratio of the continuously variable transmission on a basis of the cruise-control accelerator opening obtained by the accelerator-opening calculating means and the actual vehicle speed,

wherein the accelerator-opening calculating means comprises a map for designating the cruise-control accelerator opening on the basis of the requested torque and the engine rotation speed, and

wherein the map stores a cruise-control accelerator-opening characteristic curve set basically along an equal power line.

2. The shift control device for a continuously variable transmission according to claim 1 , wherein, in the cruise-control accelerator-opening characteristic curve stored in the map, the cruise-control accelerator opening for a low rotation speed range of the engine rotation speed is set to be greater than an accelerator opening required for accelerating a vehicle from a complete stop.

3. The shift control device for a continuously variable transmission according to claim 1 , further comprising:

target throttle opening calculating means that, based on the requested torque, outputs a target throttle opening to engine controlling means that drives a throttle motor.

4. The shift control device for a continuously variable transmission according to claim 3 , wherein the engine controlling means drives the throttle motor independent of the accelerator-opening calculating means.

5. The shift control device for a continuously variable transmission according to claim 3 , wherein the engine controlling means drives the throttle motor independent of the shift controlling means.

6. The shift control device for a continuously variable transmission according to claim 1 , wherein the equal power line is obtained by connecting dots corresponding to equal power values, each of the equal power values being obtained from a product of the engine rotation speed and an engine torque.

7. A shift control device, implemented on a computer processor, for a continuously variable transmission, the shift control device comprising:

a requested power calculator that obtains a requested power, for making an actual vehicle speed reach a target vehicle speed set during a cruise control, on a basis of a speed difference between the target vehicle speed and the actual vehicle speed;

a requested torque calculator that obtains a requested torque on a basis of the requested power and an engine rotation speed;

an accelerator-opening calculator that obtains a cruise-control accelerator opening on a basis of the requested torque and the engine rotation speed;

a shift controller that performs shift control by setting a target gear shift ratio of the continuously variable transmission on a basis of the cruise-control accelerator opening obtained by the accelerator-opening calculator and the actual vehicle speed, wherein the accelerator-opening calculator comprises a map for designating the cruise-control accelerator opening on the basis of the requested torque and the engine rotation speed; and

a storage device, in which the map stores a cruise-control accelerator-opening characteristic curve set along an equal power line.

8. The shift control device according to claim 7 , further comprising:

a target throttle opening calculator that, based on the requested torque, outputs a target throttle opening to an engine controller that drives a throttle motor.

9. The shift control device according to claim 8 , wherein the engine controller drives the throttle motor independent of the accelerator-opening calculator.

10. The shift control device according to claim 8 , wherein the engine controller drives the throttle motor independent of the shift controller.

11. The shift control device according to claim 7 , wherein the equal power is obtained by connecting dots corresponding to equal power values, each of the equal power values being obtained from a product of the engine rotation speed and an engine torque.

Assignments (3)
CHANGE OF NAME Recorded May 12, 2017
From: FUJI JUKOGYO KABUSHIKI KAISHA
To: SUBARU CORPORATION
Reel/Frame 042624/0886 →
CHANGE OF ADDRESS Recorded Oct 15, 2014
From: FUJI JUKOGYO KABUSHIKI KAISHA
To: FUJI JUKOGYO KABUSHIKI KAISHA
Reel/Frame 033989/0220 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Mar 4, 2011
From: KATO, TETSUYA
To: FUJI JUKOGYO KABUSHIKI KAISHA
Reel/Frame 026086/0006 →