Patents Assigned to Jatco Transtechnology Ltd.
  • Patent number: 6409624
    Abstract: An automatic transmission has a low clutch that assumes its engaged condition at a plurality of lower gear positions of D-range and a high clutch that assumes its engaged condition at a plurality of higher gear positions of D-range, A hydraulic control system for the transmission comprises a hydraulic section that produces a line pressure; a solenoid valve that produces a solenoid pressure upon receiving a solenoid signal; a first pressure control valve that produces a first output pressure from the line pressure by using the solenoid pressure and the first output pressure as operation signal pressures, the first output pressure having a smaller gain with respect to the solenoid pressure; a second pressure control valve that produces a second output pressure from the line pressure by using the solenoid pressure and the second output pressure as operation signal pressures, the second output pressure having a larger gain with respect to the solenoid pressure; and a switching valve that selectively assumes a fir
    Type: Grant
    Filed: June 23, 2000
    Date of Patent: June 25, 2002
    Assignee: Jatco Transtechnology Ltd.
    Inventor: Takashi Sano
  • Patent number: 6398684
    Abstract: In a control device of an automatic transmission that controls a plurality of solenoid valves by an ATCU to thereby supply and release signal pressure for controlling friction elements according to selected gear positions, the solenoid valves generate a signal pressure to be supplied to the friction elements which are engaged at a predetermined gear position in a low speed gear position group, when the ATCU stops functioning while the vehicle is driven at a low speed gear position. Shift valves supply the signal pressure to the friction elements. If the ATCU stops functioning while a gear position in a high speed gear position group is selected, the shift valves supply a signal pressure generated by manual valve to friction elements which are engaged at a predetermined gear position in the high speed gear position group.
    Type: Grant
    Filed: September 18, 2000
    Date of Patent: June 4, 2002
    Assignee: Jatco Transtechnology Ltd.
    Inventor: Kenichi Kaizu
  • Patent number: 6397968
    Abstract: A transmission unit for a hybrid vehicle includes a housing formed with a water jacket for cooling a stator of a motor. The water jacket includes a hollow annular passage having a water inlet and a water outlet. The water jacket has at least one uneven or depressed portion for avoiding an adjacent component. At the uneven portion, the cross sectional shape of the flow passage is varied gradually and smoothly so that the cross-sectional area of the flow passage remains constant. The water jacket further includes an inflow passage extending in a tangential direction to the water inlet, and an outflow passage extending in a radial direction from the water outlet.
    Type: Grant
    Filed: February 20, 2001
    Date of Patent: June 4, 2002
    Assignee: Jatco Transtechnology Ltd.
    Inventors: Taku Sugano, Sachiyo Hasegawa
  • Patent number: 6382942
    Abstract: An internal gear oil pump made of Al alloys having less mutual damage property and superior wear resistance is provided. The internal gear oil pump has a casing with a gear compartment, a drive gear, and a driven gear, all of which are the structural members of the internal gear oil pump. The casing is constituted of an Al-alloy casting. The drive gear and the driven gear are constituted of a hot plastic working material of Al—Si alloy powder. The hot plastic working material is constituted of an Al—Si alloy having a structure in which unit crystal phases are dispersed in a base matrix by 10 to 40 area percent. by the structural observation with an optical microscope, the unit. crystal phases being harder than the base matrix. The base matrix is constituted of an Al—Si alloy which contains, on weight basis, 10% to 18% Si, 4% to 8% Fe, 1% to 3% Ni, 1% to 3% Cr, and the balance being Al and incidental impurities.
    Type: Grant
    Filed: November 9, 2000
    Date of Patent: May 7, 2002
    Assignees: Mitsubishi Materials Corporation, Nissan Motor Co., Ltd., JATCO TransTechnology Ltd.
    Inventors: Masato Otsuki, Masahisa Miyahara, Makoto Yoshida, Haruo Okamoto, Akira Fujiki, Hiroyuki Nishiyama, Motohiro Suzuki
  • Patent number: 6374977
    Abstract: A drum supporting structure in an automatic transmission has a drum support immovably installed in the transmission case. The drum support includes a cylindrical hollow shaft portion on which the drum is rotatably disposed and a circular wall portion which is concentrically and integrally formed on one end of the cylindrical hollow shaft portion. A first part of the circular wall portion is secured to the transmission case and has a plurality of hydraulic fluid passages defined therein, and a second, diametrically opposed part of the circular wall portion has a plurality of blind bores defined therein. The number of the blind bores is at least the same as that of the hydraulic fluid passages. With this arrangement, the circular wall portion and thus the drum supporting structure is able to have a well-balanced structure.
    Type: Grant
    Filed: October 18, 2000
    Date of Patent: April 23, 2002
    Assignee: Jatco Transtechnology Ltd.
    Inventor: Tetsuya Inaba
  • Patent number: 6361472
    Abstract: In gear-shift control performed during normal travelling, a drive frequency of each solenoid valve is set to a higher one to suppress fluctuations or changes of a quantity or speed of a flow of a hydraulic oil concerned when the solenoid current is turned on/off to suppress fluctuations of the output hydraulic pressure. In start selection, the drive frequency of the solenoid valve is set to a lower one to reduce the number of times a plunger and a ball hit each other within the solenoid valve to reduce a sound produced by the operation of the solenoid.
    Type: Grant
    Filed: April 28, 2000
    Date of Patent: March 26, 2002
    Assignee: Jatco Transtechnology Ltd.
    Inventor: Takashi Murasugi
  • Patent number: 6361464
    Abstract: A control device of an automatic transmission has automatic shift ranges and manual setting ranges including a first speed gear position at which an engine brake is operable. The control device turns on all solenoid valves at the first speed gear position in the automatic shift driving range, turns on only the second and third solenoid valves at the first speed gear position in the manual setting range, and turns on at least one of the three solenoid valves in normal operation. This prevents a shock resulting from a shift and easily starts a vehicle even if all of the three solenoid valves supplying oil pressure to the first through third shift valves for changing gear positions are turned off. Oil channels are preset in such a manner as to achieve a high speed gear position if no oil pressure is supplied to all shift valves.
    Type: Grant
    Filed: June 21, 2000
    Date of Patent: March 26, 2002
    Assignee: Jatco Transtechnology Ltd.
    Inventor: Nobuyuki Yoneyama
  • Patent number: 6361465
    Abstract: An automatic transmission, which has automatic shift ranges and manual setting ranges having a first speed gear position at which an engine brake is operable, is constructed in such a manner that a first friction element engaged at the first speed gear position and at a backward driving gear position is connected to a pressure regulating valve controlled by a timing solenoid valve. If a gear position is automatically shifted from a gear position at which the first friction element is unengaged to a gear position at which the first friction element is engaged, the timing solenoid valve is kept on for a predetermined time to delay the engagement of the first friction element to thereby prevent the shock from the shift.
    Type: Grant
    Filed: June 21, 2000
    Date of Patent: March 26, 2002
    Assignee: Jatco Transtechnology Ltd.
    Inventor: Ikuo Hirose
  • Publication number: 20020033313
    Abstract: Drive system torsional vibration resonance while an engine is idling is prevented. An input clutch pack is connected to a rotating drive plate connected to the engine. The input clutch pack is formed from a drive side comprising an input drum, metal plates, and a retaining plate and from a driven side comprising an input clutch hub and facing plates. When the input clutch pack is disengaged, the inertial mass on the engine side with the engine serving as the vibration source, the coil spring, and the inertial mass on the drive side form a single-degree-of-freedom drive system torsional vibration model. By increasing the thickness in the axial direction of the metal plates, the drive side inertial mass is made to be 50% to 100% of the engine side inertial mass. As a result, drive system torsional vibration resonance during idling is prevented while the weight increase is kept to a minimum.
    Type: Application
    Filed: September 12, 2001
    Publication date: March 21, 2002
    Applicant: JATCO TransTechnology Ltd.
    Inventors: Yoshiaki Katou, Nobushi Yamazaki
  • Patent number: 6357289
    Abstract: An automatic transmission control system having a fail-safe function includes an automatic transmission control unit which prestores a normal state of ON-OFF settings of engaging elements and actually detects an actual state of ON-OFF positions (engagements and disengagements) of the engaging elements. The automatic transmission control unit has a comparator capable of comparing the normal state of ON-OFF settings with the actual state of ON-OFF positions of the engaging elements, and determines that a hydraulic system failure occurs when the normal state and the actual state disagree with each other.
    Type: Grant
    Filed: August 4, 2000
    Date of Patent: March 19, 2002
    Assignee: Jatco Transtechnology Ltd.
    Inventor: Toru Futawatari
  • Patent number: 6350214
    Abstract: During a shifting operation that a first engaging element is changed from an engaged state to a disengaged state, a fail-safe valve is used to forcibly drain a first engaging-element pressure from the first engaging element by using a second engaging-element pressure applied to a second engaging element brought into an engaging state from a releasing state. The fail-safe valve includes a spool and uses the second engaging-element pressure acting on the spool in one axial direction and an opposing pressure acting on the spool in the opposing direction as operating signal pressures. The fail-safe valve is switchable to a drain position, when the second engaging-element pressure is regulated toward a specified fail-safe valve operating point pressure higher than a maximum pressure value of the second engaging-element pressure regulated during the shifting operation and lower than a maximum possible engaging-element pressure.
    Type: Grant
    Filed: June 21, 2000
    Date of Patent: February 26, 2002
    Assignee: Jatco Transtechnology Ltd.
    Inventor: Takashi Murasugi
  • Patent number: 6332855
    Abstract: A sealless accumulator 14, which intervenes between a solenoid valve 4 and a spool valve 5 for absorbing vibrations of a hydraulic oil concerned, is disposed in an upper half of a valve body above an oil path 18 formed in the upper half of the valve body 16. Air discharge path 24 is provided on an opposite side of an accumulator 14 from its oil chamber in which the oil pressure is applied to the piston 22 such that when the oil pressure is applied to the oil path 18, the piston 22 is moved, the hydraulic oil is discharged through the air discharge path 24 to the outside, possible air present up within the oil path 18 flows into the accumulator 14, and then is discharged through the air discharge path 24 to the outside.
    Type: Grant
    Filed: April 28, 2000
    Date of Patent: December 25, 2001
    Assignee: Jatco Transtechnology Ltd.
    Inventor: Takashi Murasugi
  • Patent number: 6208498
    Abstract: A solenoid supply current value is predicted from a detected battery voltage, an operational fluid temperature, and the like, and a chopper ON time during chopping drive is reduced, and relatively, a chopper OFF time is increased by using, for example, a voltage correction coefficient which becomes smaller as the battery voltage becomes larger, or a temperature correction coefficient which is set smaller as the operational fluid temperature is smaller. Alternatively, an overexciting current of the solenoid is detected at least at two time points during overexcitation, and a termination time point of the overexcitation at which the overexciting current reaches a target overexciting current is predicted from the overexciting current value, and the overexcitation is terminated when the termination time point is reached.
    Type: Grant
    Filed: December 2, 1998
    Date of Patent: March 27, 2001
    Assignee: Jatco Transtechnology Ltd.
    Inventor: Yoshiaki Ueda