Patent
Control device for controlling V-belt continuously variable transmission
| العنوان: | Control device for controlling V-belt continuously variable transmission |
|---|---|
| Patent Number: | 7,402,118 |
| تاريخ النشر: | July 22, 2008 |
| Appl. No: | 10/947201 |
| Application Filed: | September 23, 2004 |
| مستخلص: | A control device for controlling a continuously variable transmission (5) is disclosed. The control device has an oil pressure control unit (100) which supplies an oil pressure to a primary pulley (10) and secondary pulley (11) based on a command signal indicative of a target speed-reduction ratio, a sensor (26) which detects a rotation speed (Np1) of the primary pulley (26), and a controller (20) which transmits the command signal indicative of the target speed-reduction ratio to the oil pressure control unit (100). The controller is programmed to set the target speed-reduction ratio to a first speed-reduction ratio (R1); calculate a first predetermined rotation speed (N1) of the primary pulley at which the V-belt reaches a first limiting temperature (T1) at the first speed-reduction ratio (R1); calculate a first elapsed time after the detected rotation speed (Np1) of the primary pulley exceeds the first predetermined rotation speed (N1); maintain the first speed-reduction ratio (R1) when the first elapsed time is equal to or less than a first predetermined time; and set the target speed-reduction ratio to a second speed-reduction ratio (R2) smaller than the first speed-reduction ratio (R1) when the first elapsed time exceeds the first predetermined time. At the second speed-reduction ratio (R2), the temperature of the V-belt should become equal to or less than the first limiting temperature (T1) throughout the permitted rotation speed region of the primary pulley. Thus, starting acceleration performance of the continuously variable transmission is enhanced. |
| Inventors: | Kimura, Yusuke (Fuji, JP); Ochiai, Tatsuo (Fuji, JP); Yoneda, Kenji (Fuji, JP); Jozaki, Tateki (Fuji, JP); Chibahara, Takeshi (Fuji, JP); Shiomi, Jun (Fuji, JP) |
| Assignees: | Jatco Ltd (Shizuoka, JP) |
| Claim: | 1. A control device for controlling a continuously variable transmission, the continuously variable transmission having a primary pulley with a permitted rotation speed region and a secondary pulley with a V-belt looped around the primary and secondary pulleys, the control device comprising: an oil pressure control unit which supplies an oil pressure to the primary pulley and secondary pulley based on a command signal indicative of a target speed-reduction ratio, a sensor which detects a rotation speed of the primary pulley, and a controller which transmits the command signal indicative of the target speed-reduction ratio to the oil pressure control unit, the controller being programmed to: set the target speed-reduction ratio to a first speed-reduction ratio; calculate a first predetermined rotation speed of the primary pulley at which the V-belt reaches a first limiting temperature at the first speed-reduction ratio; compare the detected rotation speed of the primary pulley with the first predetermined rotation speed; calculate a first elapsed time after the detected rotation speed of the primary pulley exceeds the first predetermined rotation speed; maintain the first speed-reduction ratio when the first elapsed time is equal to or less than a first predetermined time; and set the target speed-reduction ratio to a second speed-reduction ratio smaller than the first speed-reduction ratio when the first elapsed time exceeds the first predetermined time; wherein, at the second speed-reduction ratio, the temperature of the V-belt should become equal to or less than the first limiting temperature throughout the permitted rotation speed region of the primary pulley. |
| Claim: | 2. The control device as defined in claim 1 , wherein the first limiting temperature is a temperature lower than a second limiting temperature at which heat deterioration of a metal constituting the V-belt occurs. |
| Claim: | 3. The control device as defined in claim 2 , wherein the first predetermined time is an elapsed time from when the V-belt reaches the first limiting temperature until the V-belt reaches the second limiting temperature. |
| Claim: | 4. The control device as defined in claim 1 , wherein the controller is programmed to: measure a second elapsed time after setting the target speed-reduction ratio to the second speed-reduction ratio, and when the second elapsed time is larger than a second predetermined time, permit the target speed-reduction ratio to change over to the first speed-reduction ratio. |
| Claim: | 5. The control device as defined in claim 4 , wherein the second predetermined time is a sufficient time for the temperature of the V-belt to become equal to or less than the first limiting temperature. |
| Claim: | 6. The control device as defined in claim 4 , wherein the controller is programmed to measure the second elapsed time only when the rotation speed of the primary pulley is less than a second predetermined rotation speed, and an input torque of the primary pulley is less than a predetermined torque. |
| Claim: | 7. The control device as defined in claim 1 , wherein the first speed-reduction ratio corresponds to a speed-reduction ratio when the continuously variable transmission starts. |
| Claim: | 8. The control device as defined in claim 1 , wherein the controller comprises a map which specifies a relation between the rotation speed of the primary pulley and a rotation speed of the secondary pulley at the first limiting temperature, and the controller is programmed to calculate the first predetermined rotation speed from the first speed-reduction ratio by referring to the map. |
| Claim: | 9. A control device for controlling a continuously variable transmission, the continuously variable transmission having a primary pulley with a permitted rotation speed region and a secondary pulley with a V-belt looped around the primary and secondary pulleys, the control device comprising: supply means for supplying an oil pressure to the primary pulley and secondary pulley based on a command signal indicative of a target speed-reduction ratio, detecting means for detecting a rotation speed of the primary pulley, transmitting means for transmitting the command signal indicative of the target speed-reduction ratio to the supply means, first setting means for setting the target speed-reduction ratio to a first speed-reduction ratio; first calculating means for calculating a first predetermined rotation speed of the primary pulley at which the V-belt reaches a first limiting temperature at the first speed-reduction ratio; comparing means for comparing the detected rotation speed of the primary pulley with the first predetermined rotation speed; second calculating means for calculating a first elapsed time after the detected rotation speed of the primary pulley exceeds the first predetermined rotation speed; maintaining means for maintaining the first speed-reduction ratio when the first elapsed time is equal to or less than a first predetermined time; and second setting means for setting the target speed-reduction ratio to a second speed-reduction ratio smaller than the first speed-reduction ratio when the first elapsed time exceeds the first predetermined time; wherein, at the second speed-reduction ratio, the temperature of the V-belt should become equal to or less than the first limiting temperature throughout the permitted rotation speed region of the primary pulley. |
| Claim: | 10. A control method for controlling a continuously variable transmission, the continuously variable transmission having a primary pulley with a permitted rotation speed region and a secondary pulley with a V-belt looped around the primary and secondary pulleys, and an oil pressure control unit which supplies an oil pressure to the primary pulley and secondary pulley based on a target speed-reduction ratio, the control method comprising: detecting a rotation speed of the primary pulley, setting the target speed-reduction ratio to a first speed-reduction ratio; calculating a first predetermined rotation speed of the primary pulley at which the V-belt reaches a first limiting temperature at the first speed-reduction ratio; comparing the detected rotation speed of the primary pulley with the first predetermined rotation speed; calculating a first elapsed time after the detected rotation speed of the primary pulley exceeds the first predetermined rotation speed; maintaining the first speed-reduction ratio when the first elapsed time is equal to or less than a first predetermined time; and setting the target speed-reduction ratio to a second speed-reduction ratio smaller than the first speed-reduction ratio when the first elapsed time exceeds the first predetermined time; wherein, at the second speed-reduction ratio, the temperature of the V-belt should become equal to or less than the first limiting temperature throughout the permitted rotation speed region of the primary pulley. |
| Current U.S. Class: | 474/18 |
| Patent References Cited: | 4673378 June 1987 Tokoro et al. 5067603 November 1991 Kato et al. 5713815 February 1998 Funatsu et al. 6547691 April 2003 Hino 7041018 May 2006 Ochiai et al. 7211013 May 2007 Watanabe et al. 2003/0032513 February 2003 Aoyama 2004/0063523 April 2004 Jozaki et al. 2004/0092344 May 2004 Watanabe et al. 2004/0116219 June 2004 Watanabe et al. 62-270855 November 1987 62-286847 December 1987 9-026021 January 1997 09014362 January 1997 |
| Primary Examiner: | Charles, Marcus |
| Attorney, Agent or Firm: | Foley & Lardner LLP |
| رقم الانضمام: | edspgr.07402118 |
| قاعدة البيانات: | USPTO Patent Grants |
| الوصف غير متاح. |