Hydraulic control device of belt-type continuously variable transmission

Patent metadata

Field	Value
Publication number	US-10054221-B2
Application number	US-201414784364-A
Country	US
Kind code	B2
Filing date	Apr 18, 2014
Priority date	Apr 19, 2013
Publication date	Aug 21, 2018
Grant date	Aug 21, 2018

Abstract

In a hydraulic control device of a belt-type continuously variable transmission that includes: a first hydraulic actuator that is provided in a primary pulley and reduces a width of a belt groove when hydraulic pressure is applied thereto; and a first control valve that regulates predetermined source pressure to be gear-change hydraulic pressure for setting or changing a gear change ratio and outputs the gear-change hydraulic pressure to the first hydraulic actuator, gear change equipment is included that regulates the source pressure to be the gear-change hydraulic pressure so as to regulate the hydraulic pressure of the first hydraulic actuator when the hydraulic pressure of the first hydraulic actuator is rapidly changed to change the width of the belt groove.

First claim

The invention claimed is:

1. A belt-type continuously variable transmission, comprising:
paired pulleys, each having a belt groove around which a belt is wound;
a first hydraulic actuator that is provided to either one of the paired pulleys and reduces a width of the belt groove when hydraulic pressure is applied thereto;
a hydraulic pressure control valve that regulates predetermined source pressure to be gear-change hydraulic pressure for setting or changing a gear change ratio and outputs the gear-change hydraulic pressure to the first hydraulic actuator through a fluid passage; and
gear change equipment that applies a hydraulic pressure to the first hydraulic actuator through the fluid passage or lowers a hydraulic pressure of the first hydraulic actuator without regulating the source pressure to be the gear-change hydraulic pressure by the hydraulic pressure control valve when the hydraulic pressure of the first hydraulic actuator is changed rapidly to change the width of the belt groove in the one pulley,
wherein:
the hydraulic pressure control valve includes a first pressure regulator valve that applies the hydraulic pressure to or lowers the hydraulic pressure of the first hydraulic actuator in accordance with first signal pressure and feedback pressure of the first hydraulic actuator that are applied thereto, and
the gear change equipment includes signal pressure applying equipment that exerts second signal pressure in a direction to increase or lower the feedback pressure applied to the first pressure regulator valve and applies the hydraulic pressure to or lowers the hydraulic pressure of the first hydraulic actuator without regulating the source pressure to be the gear-change hydraulic pressure by the hydraulic pressure control valve.

2. The belt-type continuously variable transmission according to claim 1 wherein:
the hydraulic pressure of the first hydraulic actuator is rapidly changed to change the width of the belt groove in the one pulley when a speed to change the gear change ratio is increased.

3. The belt-type continuously variable transmission according to claim 1 wherein:
the signal pressure applying equipment includes a first switching valve that is configured to rapidly change the hydraulic pressure of the first hydraulic actuator so as to change the width of the belt groove in the one pulley and thereby switch an oil passage communicated to the first pressure regulator valve to exert the second signal pressure on the first pressure regulator valve.

4. The belt-type continuously variable transmission according to claim 3 further comprising:
a first clutch that is configured be engaged even when power transmission between a power source and a drive wheel is blocked; and
a first control valve that outputs fourth signal pressure for engaging the first clutch wherein:
the first switching valve exerts the second signal pressure on the first pressure regulator valve when the fourth signal pressure is increased.

5. The belt-type continuously variable transmission according to claim 4 wherein:
the first switching valve exerts the second signal pressure on the first pressure regulator valve in accordance with the first signal pressure and the fourth signal pressure.

6. The belt-type continuously variable transmission according to claim 4 wherein:
the first clutch includes a second clutch that is engaged during start of a vehicle and allows power transmission between the power source and the drive wheel without interposing the belt therebetween.

7. The belt-type continuously variable transmission according to claim 3 further comprising:
a third clutch that is engaged to allow power transmission between a power source and a drive wheel; and
a second control valve that outputs fifth signal pressure for engaging the third clutch wherein:
the first switching valve exerts the second signal pressure on the first pressure regulator valve when the fifth signal pressure is lowered.

8. The belt-type continuously variable transmission according to claim 7 comprising:
a second hydraulic actuator that is provided in another pulley of the paired pulleys and reduces the width of the belt groove when being applied with the hydraulic pressure; and
a third control valve that outputs sixth signal pressure for controlling the hydraulic pressure of the second hydraulic actuator wherein:
the first switching valve exerts the second signal pressure on the first pressure regulator valve in accordance with the fifth signal pressure and the sixth signal pressure.

9. The belt-type continuously variable transmission according to claim 8 wherein:
the first switching valve exerts the second signal pressure on the first pressure regulator valve in accordance with the first signal pressure, the fifth signal pressure, and the sixth signal pressure.

10. The belt-type continuously variable transmission according to claim 1 wherein:
the gear change equipment includes a second switching valve that is provided in a first oil passage communicated with the hydraulic pressure control valve and the first hydraulic actuator, and that, when the hydraulic pressure of the first hydraulic actuator is changed rapidly to change the width of the belt groove in the one pulley, switches an oil passage communicated to the first hydraulic actuator when seventh signal pressure is applied thereto, and applies the hydraulic pressure to or lowers the hydraulic pressure of the first hydraulic actuator.

11. The belt-type continuously variable transmission according to claim 10 further comprising:
a fourth clutch that is configured to be engaged even when power transmission between a power source and a drive wheel is blocked; and
a fourth control valve that outputs eighth signal pressure for engaging the fourth clutch wherein:
the second switching valve applies the hydraulic pressure to or lowers the hydraulic pressure of the first hydraulic actuator when the eighth signal pressure is increased.

12. The belt-type continuously variable transmission according to claim 11 further comprising:
a second pressure regulator valve that outputs ninth signal pressure for applying the hydraulic pressure to and lowering the hydraulic pressure of the first hydraulic actuator wherein:
the second switching valve applies the hydraulic pressure to or lowers the hydraulic pressure of the first hydraulic actuator in accordance with the eighth signal pressure and the ninth signal pressure.

13. The belt-type continuously variable transmission according to claim 11 wherein:
the fourth clutch includes a fifth clutch that is engaged during start of a vehicle and allows the power transmission between the power source and the drive wheel without interposing the belt therebetween.

14. The belt-type continuously variable transmission according to claim 10 further comprising:
a sixth clutch that is engaged to allow power transmission between a power source and a drive wheel; and
a fifth control valve that outputs tenth signal pressure for engaging the sixth clutch wherein:
the second switching valve applies the hydraulic pressure to or lowers the first hydraulic pressure of the hydraulic actuator when the tenth signal pressure is lowered.

15. The belt-type continuously variable transmission according to claim 14 comprising:
a third hydraulic actuator that is provided in another pulley of the paired pulleys and reduces the width of the belt groove when the hydraulic pressure is applied thereto; and
a sixth control valve that outputs eleventh signal pressure for controlling the hydraulic pressure of the third hydraulic actuator where

Assignees

• Ogata Yusuke
• Mizuno Yoshihiro
• Watanabe Yasuyuki
• Hattori Masashi
• Tokunaga Junichi
• Hayashi Toshiaki
• Toyota Motor Co Ltd

Inventors

• Ogata Yusuke
• Mizuno Yoshihiro
• Watanabe Yasuyuki
• Hattori Masashi
• Tokunaga Junichi
• Hayashi Toshiaki

Classifications

• F16H61/662

  with endless flexible members · CPC title

• F16H61/66259 Primary

  using electrical or electronical sensing or control means · CPC title

• F16H2061/6605

  Control for completing downshift at hard braking · CPC title

• F16H61/0265 Primary

  for gearshift control, e.g. control functions for performing shifting or generation of shift signals · CPC title

• F16H9/16

  using two pulleys, both built-up out of adjustable conical parts · CPC title