Abstract: A hydraulic control device for an automatic transmission includes a first solenoid valve, a second solenoid valve, a third solenoid valve, a preliminary shift speed switching valve, and a hydraulic pressure supply switching valve. A second friction engagement element is engaged at high speed side shift speeds, a low speed that is one of low speed side shift speeds is achieved by engagement of a first friction engagement element and a third friction engagement element, and a high speed that is one of the high speed side shift speeds is achieved by engagement of a second friction engagement element and the third friction engagement element.

Abstract: A valve assembly includes a plurality of solenoid valves, each solenoid valve having a pressure-regulating valve portion formed by a sleeve having a plurality of valve-side ports and a spool for opening and closing the valve-side ports, and a solenoid portion having a plunger for driving the spool and a coil for electromagnetically driving the plunger; and a valve body having a plurality of insertion holes into which the solenoid valves are inserted, and having ports that are connected to the plurality of valve-side ports in a state in which the solenoid valves are mounted.

Abstract: A lock-up clutch is arranged in parallel with a power transmission path between a pump impeller and a turbine runner of a fluid coupling arranged between the drive side and the load side, wherein the lock-up clutch changes the power transmission path. A stall capacity factor is determined using an engine speed at which the maximum engine torque on the drive side is generated, and the rotation on the drive side is transmitted to the load side by using the stall capacity factor. Therefore, optimal acceleration can be obtained by setting the stall capacity factor such that the stall rotational speed is in the vicinity of the rotational speed at which the maximum engine torque is generated. Thus, drivability can be improved by obtaining a control amount with which the vehicle speed responds as expected to the accelerator, there is no uncomfortable sensation, and fuel economy can be improved.

Abstract: A hydraulic control apparatus of an automatic transmission. The hydraulic control apparatus of the automatic transmission has a hydraulic servo for controlling an engaging state of a clutch C-1 on the basis of supplied oil pressure, a linear solenoid valve for C-1 for outputting signal pressure by adjusting the oil pressure, a control valve for outputting control pressure provided by adjusting line pressure PL on the basis of the signal pressure of the linear solenoid valve for C-1, and a C-1 apply relay valve for inputting, selectively switching and outputting the control pressure and the line pressure PL to the hydraulic servo. An orifice for regulating the flow rate of the oil is arranged in an oil path g for inputting the line pressure PL to this C-1 apply relay valve.

Abstract: Lubricating oil supply holes are drilled into a first member that is fitted to a plurality of first annular plates by a spline. Of splines to which each lubricating oil supply hole corresponds, lubricating oil grooves provided in the plurality of first annular plates do not overlap the splines on at least one of the front and rear surfaces of the first annular plates, and therefore lubricating oil flowing out of the lubricating oil supply holes is dispersed in a circumferential direction and flows from the inner periphery to the outer periphery of the first annular plates, rather than gathering in each lubricating oil groove and flowing in an outer peripheral direction. As a result, a force generated by an axial lubricating oil flow, which acts in a direction for causing the second annular plates to contact friction materials on the first annular plates, is suppressed, leading to a reduction in drag torque.

Abstract: A hydraulic control apparatus of an automatic transmission. The hydraulic control apparatus of the automatic transmission has a hydraulic servo for controlling an engaging state of a clutch C-1 on the basis of supplied oil pressure, a linear solenoid valve for C-1 for outputting signal pressure by adjusting the oil pressure, a control valve for outputting control pressure provided by adjusting line pressure PL on the basis of the signal pressure of the linear solenoid valve for C-1, and a C-1 apply relay valve for inputting, selectively switching and outputting the control pressure and the line pressure PL to the hydraulic servo. An orifice for regulating the flow rate of the oil is arranged in an oil path g for inputting the line pressure PL to this C-1 apply relay valve.

Abstract: A hydraulic control apparatus for an automatic transmission including a hydraulic pressure source, hydraulic paths, hydraulic servos for operating friction elements which are coupled with the hydraulic source an the hydraulic paths, a control device arranged on the hydraulic paths for operating engagement release through supply/removal of hydraulic pressure to the hydraulic servos and valves which are arranged on the hydraulic path for cutting off hydraulic pressure from the hydraulic pressure source to the hydraulic servo with hydraulic pressure in the downstream side of the control device as signal pressure.

Abstract: To make it possible to maintain speeds during failures in an automatic transmission that does not have exclusive friction elements corresponding to the attainment of each speed. The hydraulic control apparatus of an automatic transmission, provided with control means 71-74 for supplying regulated pressure to each of the hydraulic servos 81-84 that are first through fourth friction elements to which hydraulic pressure is supplied from the oil path L1, and provided with switching valves (1)-(5) for cutting off the supply of hydraulic pressure to friction elements other than the friction elements that engage in each speed, on the upstream side of the supply paths L31, L32, L10, L11 and L12. Each switching valve is switched by hydraulic pressure (C1-C3, B1 pressures) regulated by the control means that achieve regulated pressure operating conditions during failures, and selective application of signal pressure (Sol, SolB, SoIC pressures) output by the control means as operating means.

Abstract: A hydraulic control apparatus for automatic transmissions, capable of adapting the apparatus to a change in the specifications for a lockup clutch which causes the relationship between the supplying and discharging of a hydraulic pressure for a lockup control operation to be reversed with respect to the connection of oil passages. A valve body of the hydraulic control apparatus is formed by laminating at least two members on each other, and has a valve for regulating a hydraulic pressure supplied to a lockup clutch of a hydraulic transmission unit, a control unit for applying a signal pressure to the pressure regulating valve, a source pressure oil passage for supplying a basic pressure for a pressure regulating operation, and drain oil passage communicated with a drain port. The pressure regulating passage is provided at both sides of a port, which communicates with a lockup oil chamber via an oil passage, with a port communicating with an oil passage, and a port communicating with another oil passage.

Abstract: A hydraulic control system includes switching mechanisms for receiving as a signal pressure a hydraulic pressure which is output from each shifting mechanism when all units of the shifting mechanisms are caused to output a hydraulic pressure, and being responsive to the reception of the signal pressure to be switched to a predetermined state for blocking a hydraulic-pressure supply path to specific hydraulic servos, thereby achieving a specific speed out of a plurality of speeds; and supply switching mechanisms provided in a hydraulic-pressure supply path to a hydraulic servo which is not included in the specific hydraulic servos, for switching between supply and cut-off of the hydraulic pressure to the hydraulic servo so as to assure two speeds in the event of the signal failure in a hydraulic control system for individually controlling engaging elements in an automatic transmission by using electric signals.

Abstract: A structure in which a hydraulic-pressure control applied pressure for controlling each engagement element of an automatic transmission is realized by using an electric signal such that combinations of engagement which encounter a tie-up in case of a failure of the signal lead to interlocking are inhibited to prevent deterioration in the durability of each engagement element. An automatic transmission incorporates a planetary gear transmission mechanism using selective engagement of at least five engagement elements to realize six gear ratios, and a hydraulic-pressure control apparatus for controlling the engagement elements of the transmission mechanism. Valves are provided which inhibit combinations of engagement of two or more engagement elements of the five engagement elements for interlocking the transmission mechanism.

Abstract: The automatic transmission of the present invention prevents fluctuation of torque transmission through a band brake. In the hydraulic operator for the band brake, a resilient elastic cushion is provided between a rod abutting one end of the band of the band brake and a piston. Any slippage between the band and drum of the band brake will result in oscillation of the rod. However, the elastic cushion absorbs oscillation of the rod, thereby isolating the piston from that oscillation.

Abstract: A hydraulic control system includes switching mechanisms for receiving as a signal pressure a hydraulic pressure which is output from each shifting mechanism when all units of the shifting mechanisms are caused to output a hydraulic pressure, and being responsive to the reception of the signal pressure to be switched to a predetermined state for blocking a hydraulic-pressure supply path to specific hydraulic servos, thereby achieving a specific speed out of a plurality of speeds; and supply switching mechanisms provided in a hydraulic-pressure supply path to a hydraulic servo which is not included in the specific hydraulic servos, for switching between supply and cut-off of the hydraulic pressure to the hydraulic servo so as to assure two speeds in the event of the signal failure in a hydraulic control system for individually controlling engaging elements in an automatic transmission by using electric signals.

Abstract: A hydraulic control system includes switching mechanisms for receiving as a signal voltage a hydraulic pressure which is output from each shifting mechanism when all units of the shifting mechanisms are caused to output a hydraulic pressure, and being responsive to the reception of the signal pressure to be switched to a predetermined state for blocking a hydraulic-pressure supply path to specific hydraulic servos, thereby achieving a specific speed out of a plurality of speeds; and supply switching mechanisms provided in a hydraulic-pressure supply path to a hydraulic servo which is not included in the specific hydraulic servos, for switching between supply and cut-off of the hydraulic pressure to the hydraulic servo so as to assure two speeds in the event of the signal failure in a hydraulic control system for individually controlling engaging elements in an automatic transmission by using electric signals.

Abstract: To make it possible to maintain speeds during failures in an automatic transmission that does not have exclusive friction elements corresponding to the attainment of each speed. The hydraulic control apparatus of an automatic transmission, provided with control means 71-74 for supplying regulated pressure to each of the hydraulic servos 81-84 that are first through fourth friction elements to which hydraulic pressure is supplied from the oil path L1, and provided with switching valves (1)-(5) for cutting off the supply of hydraulic pressure to friction elements other than the friction elements that engage in each speed, on the upstream side of the supply paths L31, L32, L10, L11 and L12. Each switching valve is switched by hydraulic pressure (C1-C3, B1 pressures) regulated by the control means that achieve regulated pressure operating conditions during failures, and selective application of signal pressure (So1, So1B, So1C pressures) output by the control means as operating means.

Abstract: A hydraulic control apparatus of automatic transmission comprising a hydraulic pressure source, hydraulic paths, hydraulic servos for operating friction elements which are coupled with the hydraulic source and the hydraulic paths, a control device arranged on the hydraulic paths for operating engagement release through supply/removal of hydraulic pressure to the hydraulic servos and valves which are arranged on the hydraulic path for cutting off hydraulic pressure from the hydraulic pressure source to the hydraulic servo with hydraulic pressure in the downstream side of the control means as signal pressure.

Abstract: A hydraulic control apparatus for automatic transmissions, capable of adapting the apparatus to a change in the specifications for a lockup clutch which causes the relationship between the supplying and discharging of a hydraulic pressure for a lockup control operation to be reversed with respect to the connection of oil passages. A valve body of the hydraulic control apparatus is formed by laminating at least two members on each other, and has a valve for regulating a hydraulic pressure supplied to a lockup clutch of a hydraulic transmission unit, a control unit for applying a signal pressure to the pressure regulating valve, a source pressure oil passage for supplying a basic pressure for a pressure regulating operation, and drain oil passage communicated with a drain port. The pressure regulating passage is provided at both sides of a port, which communicates with a lockup oil chamber via an oil passage, with a port communicating with an oil passage, and a port communicating with another oil passage.

Abstract: A hydraulic servo includes a cylinder, a piston and a rod. The piston divides the interior space of the cylinder between a closed hydraulic chamber and a back chamber which has an opening to the interior space of an automatic transmission. The rod is slidably mounted in the piston for relative movement through a predetermined distance. A frictional engagement element is engaged by the rod which is extended from one end of the cylinder by applying a hydraulic pressure to the hydraulic chamber. A passage is provided between the piston and the rod which is opened or closed by the relative movement between the piston and rod so that the hydraulic chamber and the back chamber are connected or disconnected. A valving arrangement (“closer”) closes the passage at the end of the return stroke of the piston toward the hydraulic chamber.

Abstract: When a shift to a second gear ratio (second ratio) is determined during a shift control for a first shift (shift from fourth ratio to third ratio), the process status, or circumstances, of the first shift is determined using a hydraulic pressure for a fourth brake being engaged at the determination. When the process status, that is, the process circumstances, is in early phase, the first shift is interrupted and shift control for the direct shift to the second ratio (shift from fourth ratio to second ratio) is performed (first shift pattern). When the process status is in a late phase, the first shift control is continued, and after ending of the first shift control, the control for the shift to the second gear ratio (shift from third ratio to second ratio) is performed (second shift pattern). In the case of power off state, the second shift pattern is performed irrespective of the process status.

Abstract: When a vehicle driving state of an automatic transmission is changed to a power-off state from a power-on state during a down shift involving the disengagement of one friction element and the engagement of another friction element, a disengagement side pressure PA is reduced rapidly by a feedback control based on the change in gear ratio because of a reduction of an input torque. The disengagement side pressure control is unable to complete change of the gear ratio to complete the down shift. When the disengagement side pressure is reduced to a value less than a return spring load pressure PG or when the gear ratio change has not achieved a basic value in a predetermined time, the down shift control is changed from primary control by the disengagement side pressure control to primary control by an engagement side control so that the gear ratio change is completed by control of the engagement side pressure.