摘要:
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. In a speed that has been attained, the supply path to friction elements that are not to be engaged is cut off. Through this, even during failures the regulated pressure action of the control means corresponding to friction elements that are not to be engaged is ineffective, so the speed that has been attained is fixed.
摘要:
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.
摘要:
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. The openings of the oil passages provided in one member of the valve body are provided so as to overlap respectively both the openings of the source oil passage and drain oil passage provided in the other member thereof. The communication relationship between the two oil passages and the source pressure oil passage and drain oil passage is changed by the communication ports and closing portions of a separator plate inserted between the two members of the valve body.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
In a driven state, a hydraulic pressure of disengagement side is set at a stroke pressure, a one-way clutch in an operating state is over-run, an engine rotation speed is in an idle state, and an automatic transmission is in a neutral state. In a drive state, the hydraulic pressure of disengagement side is controlled so that a difference between an engine rotation speed and an input rotation speed reaches a difference between the both rotation speeds at a start of the shift control. In a state of a synchronized rotation after the shift, the hydraulic pressure of disengagement side is controlled so that the input rotation reaches the synchronized rotation.
摘要:
If a shift to the 3rd speed is decided during the 5th-4th speed shift, in which the hydraulic servo for a second clutch is released by pressure regulation control, a changeover valve is switched by a solenoid valve so that the fluid pressure P.sub.C2 from the pressure regulating valve is conducted to a third clutch hydraulic servo. Thereby, the third clutch hydraulic servo pressure P.sub.C3 stands by at a predetermined engaging pressure P.sub.H and, at the same time, the servo-start of a fourth brake fluid pressure P.sub.B4 is performed by another pressure regulating valve. Meanwhile, the fluid pressure P.sub.C2 is released by an accumulator. After the servo-start ends and the 4th speed is established, the 4-3 speed shift control is performed, thus preventing shift shock and reducing shift duration.
摘要:
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.