Patents by Inventor Makio Tsubota

Makio Tsubota has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 6347521
    Abstract: The invention provides a temperature control device with excellent temperature uniformity and thermal response, which can be manufactured easily, and a manufacturing method for the same. A thermoelectric device 21 is arranged between a substrate mounting plate 1 and a cooling plate 3. Copper foil electrodes 5, 5, . . . on the upper side of the thermoelectric device 21 are adhered to a lower surface of the substrate mounting plate 1 with an adhesive sheet 17 covering substantially the entire lower surface of the substrate mounting plate 1, and copper foil electrodes 7, 7, . . . on the lower side of the thermoelectric device 21 are adhered to an upper surface of the cooling plate 3 with an adhesive sheet 19 covering substantially the entire upper surface of the substrate mounting plate 1.
    Type: Grant
    Filed: October 11, 2000
    Date of Patent: February 19, 2002
    Assignee: Komatsu LTD
    Inventors: Kanichi Kadotani, Makio Tsubota, Hironori Akiba, Tadayuki Hanamoto
  • Patent number: 5740315
    Abstract: A fluid heating apparatus in which a heating unit (2) and a fluid supply adjusting unit (3) are accommodated in a casing in a manner separated from each other and connected through a flow-in tube (8) and a flow-out tube (9) and the fluid supply adjusting unit (3) is arranged vertically upward and downward on the side of the heating unit (2).
    Type: Grant
    Filed: December 22, 1994
    Date of Patent: April 14, 1998
    Assignee: Kabushiki Kaisha Komatsu Seisakusho
    Inventors: Tetsuo Onishi, Hiromasa Takamatsu, Makio Tsubota
  • Patent number: 5573473
    Abstract: A lock-up clutch by way of which input/output shafts of a torque converter are operatively connected to each other is connected to an electronic type pressure control valve. During speed changing in a transmission, the problem of interruption of torque transmission can be solved by turning off the lock-up clutch at the time when filling of one of the speed changing clutches to be next brought into an operatively engaged state with hydraulic oil is completed. Hydraulic pressure (P.sub.t) in the torque converter is exerted on the back 100 pressure portion of a piston of the lock-up clutch while hydraulic pressure (P.sub.t) in the torque converter is exerted on the proportional solenoid side of the pressure control valve, making it possible to reduce the initial hydraulic pressure. During speed changing, the lock-up clutch is not fully released from the engaged state but maintains its operative state at low pressure, causing shock from shifting the lock-up state to be reduced.
    Type: Grant
    Filed: February 17, 1995
    Date of Patent: November 12, 1996
    Assignee: Kabushiki Kaisha Komatsu Seisakusho
    Inventors: Yoshio Asayama, Makio Tsubota, Yasunori Okura, Takayuki Sato
  • Patent number: 5417622
    Abstract: A lock-up clutch by way of which input/output shafts of a torque converter are operatively connected to each other is connected to an electronic type pressure control valve. During speed changing in a transmission, the problem of interruption of torque transmission can be solved by turning off the lock-up clutch at the time when filling of one of the speed changing clutches to be next brought into an operatively engaged state with hydraulic oil is completed. Hydraulic pressure (P.sub.t) in the torque converter is exerted on the back pressure portion of a piston of the lock-up clutch while hydraulic pressure (P.sub.t) in the torque converter is exerted on the proportional solenoid side of the pressure control valve, making it possible to reduce the initial hydraulic pressure. During speed changing, the lock-up clutch is not fully released from the engaged state but maintains its operative state at low pressure, causing shock from shifting the lock-up state to be reduced.
    Type: Grant
    Filed: June 18, 1991
    Date of Patent: May 23, 1995
    Assignee: Kabushiki Kaisha Komatsu Seisakusho
    Inventors: Yoshio Asayama, Makio Tsubota, Yasunori Okura, Takayuki Sato
  • Patent number: 5209141
    Abstract: During shift change, a discrimination is made as to a load, a quantity of residual hydraulic oil in respective shift change clutches (F, R, 1 to 4) and a state of shift change which has been effected from what speed stage to what speed stage so that a pattern of electrical commands to be issued to pressure control valves (51 to 56) for required shift change clutches is variably controlled depending on results derived from the above discrimination. Thus, smooth shift change can always be achieved regardless of running conditions. Electrical commands (C.sub.1 to C.sub.6) to be fed to the respective pressure control valves (51 to 56) are compared with electrical currents (I.sub.1 to I.sub.6) outputted from drive circuits and outputs (S.sub.1 to S.sub.6) from clutch pressure detecting means (101 to 106) for each clutch, whereby an abnormality is detected with the relevant clutch based on results derived from the comparison.
    Type: Grant
    Filed: February 26, 1992
    Date of Patent: May 11, 1993
    Assignee: Kabushiki Kaisha Komatsu Seisakusho
    Inventors: Yoshio Asayama, Makio Tsubota, Yasunori Okura, Takayuki Sato
  • Patent number: 5168973
    Abstract: The present invention provides an apparatus for controlling a hydraulic pressure usable for a clutch wherein the appratus is employed for a transmission mounted on a construction machine or the like in such a manner that it is provided separately for a plurality of clutches 1 and it is controlled individually. The apparatus includes a first valve 3 for allowing a large amount of hydraulic oil to flow in the clutch and a second valve 4 for electronically controlling a clutch pressure so that the termination of filling and the clutch pressure are detected by a simple structural arrangement on the basis of a displacement of a spool 21 for the first valve 3 and a separately disposed piston. In addition, appearing of an overshoot pressure on the termination of filling is prevented by providing a difference in pressue receiving areas on the spool 21 for the first valve.
    Type: Grant
    Filed: April 29, 1991
    Date of Patent: December 8, 1992
    Assignee: Kabushiki Kaisha Komatsu Seisakusho
    Inventors: Yoshio Asayama, Makio Tsubota, Yasunori Okura, Takayuki Sato
  • Patent number: 5113720
    Abstract: During shift change, a discrimination is made as to a load, a quantity of residual hydraulic oil in respective shift change clutches (F, R, 1 to 4) and a state of shift change which has been effected from what speed stage to what speed stage so that a pattern of electrical commands to be issued to pressure control valves for required shift change clutches is variably controlled depending on results derived from the above discrimination. Thus, smooth shift change can always be achieved regardless of running conditions. Electrical commands to be fed to the respective pressure control valves are compared with electrical currents outputted from drive circuits and outputs from clutch pressure detecting means for each clutch, whereby an abnormality is detected with the relevant clutch based on results derived from the comparison. Once an abnormality is detected, an adequate disposal for processing the abnormality is executed so as to reliably prevent double engagement from taking place with clutches.
    Type: Grant
    Filed: December 20, 1989
    Date of Patent: May 19, 1992
    Assignee: Kabushiki Kaisha Komatsu Seisakusho
    Inventors: Yoshio Asayama, Makio Tsubota, Yasunori Okura, Takayuki Sato
  • Patent number: 5092200
    Abstract: The present invention is concerned with a transmission constructed in the two-staged structure including main speed changing units (1st, 2nd) and auxiliary speed changing units (H, L) which are provided with clutches (H, L, 1st, 2nd) which in turn are individually connected to electronic type pressure control valves (21 to 24) so as to enable the respective clutches to be controlled separately. When it is found that pressurized hydraulic oil delivered from a hydraulic pump has a shortage in amount at the time of starting of forward movement of a vehicle, feeding of hydraulic oil to the clutches (H, L) on the main speed changing unit side and the clutches (1st, 2nd) on the auxiliary speed changing unit side is effected with a certain time difference kept therebetween in order to suppress fluctuation in filling time due to reduction of an amount of hydraulic oil delivered from the hydraulic pump.
    Type: Grant
    Filed: September 20, 1990
    Date of Patent: March 3, 1992
    Assignee: Kabushiki Kaisha Komatsu Seisakusho
    Inventors: Yoshio Asayama, Makio Tsubota, Yasunori Okura, Takayuki Sato
  • Patent number: 5038286
    Abstract: A method for controlling a transmission system mounted on such as a traveling machine or a construction machine, the transmission system having a two-stage clutch configuration in which a speed is selected through a combination of a plurality of sub transmission clutches and a plurality of main transmission clutches. At the time of speed change, engagement is started beginning with the main transmission clutch side, and the engagement of the sub transmission clutch is commenced upon completion of the filling of the oil in the main transmission clutch, thereby reducing the two speed-change shocks, including a reverse shock, which are conventionally experienced.
    Type: Grant
    Filed: June 7, 1990
    Date of Patent: August 6, 1991
    Assignee: Kabushiki Kaisha Komatsu Seisakusho
    Inventors: Yoshio Asayama, Makio Tsubota, Yasunori Okura, Takayuki Sato
  • Patent number: 5035312
    Abstract: The present invention provides an apparatus for controlling a hydraulic pressure usable for a clutch wherein the apparatus is employed for a transmission mounted on a construction machine or the like in such a manner that it is provided separately for a plurality of clutches and it is controlled individually. The apparatus includes a first valve for allowing a large amount of hydraulic oil to flow in the clutch and a second valve for electronically controlling a clutch pressure so that the termination of filling and the clutch pressure are detected by a simple structural arrangement on the basis of a displacement of a spool for the first valve and a separately disposed piston. In addition, appearing of an overshoot pressure on the termination of filling is prevented by providing a difference in pressure receiving areas on the spool for the first valve.
    Type: Grant
    Filed: November 22, 1988
    Date of Patent: July 30, 1991
    Assignee: Kabushiki Kaisha Komatsu Seisakusho
    Inventors: Yoshio Asayama, Makio Tsubota, Yasunori Okura, Takayuki Sato
  • Patent number: 4993285
    Abstract: The present invention is concerned with a transmission constructed in the two-staged structure including main speed changing units (1st, 2nd) and auxiliary speed changing units (H, L) which are provided with clutches (H, L 1st, 2nd) which in turn are individually connected to electronic type pressure control valves (21 and 24) so as to enable the respective clutches to be controlled separately. When it is found that pressurized hydraulic oil delivered from a hydraulic pump has a shortage in amount at the time of starting of forward movement of a vehicle, feeding of hydraulic oil to the clutches (H, L) on the main speed changing unit side and the clutches (1st, 2nd) on the auxiliary speed changing unit side is effected with a certain time difference kept therebetween in order to suppress fluctuation in filling time due to reduction of an amount of hydraulic oil delivered from the hydraulic pump.
    Type: Grant
    Filed: December 7, 1988
    Date of Patent: February 19, 1991
    Assignee: Kabushiki Kaisha Komatsu Seisakusho
    Inventors: Yoshio Asayama, Makio Tsubota, Yasunori Okura, Takayuki Sato
  • Patent number: 4836057
    Abstract: A plurality of clutch hydraulic pressure gradual increase patterns for maintaining jerk value at a level of a target value are previously determined in dependence on vehicle weight and speed stages; a clutch hydraulic pressure gradual increase pattern corresponding to the vehicle weight and speed stage selected at the time of speed change is selected from the aforesaid plurality of clutch hydraulic pressure gradual increases patterns. Then, hydraulic pressure in a speed change clutch to be engaged is caused to increase gradually in accordance with the thus selected clutch hydraulic pressure gradual increase pattern.At the time point when a speed change command is issued, a speed change clutch to be subsequently brought in the engaged state is fed with hydraulic oil and gradually increasing hydraulic pressure is exerted on the speed change clutch after the time point when termination of filling time is confirmed with respect to this speed change clutch.
    Type: Grant
    Filed: December 16, 1986
    Date of Patent: June 6, 1989
    Assignee: Kabushiki Kaisha Komatsu Seisakusho
    Inventors: Yoshio Asayama, Makio Tsubota, Yukitaka Takitani, Yasunori Okura