摘要:
A control apparatus executes appropriate speed change control under any operating conditions encountered during an up-shift by change-over, without requiring an increase in control logic. Engagement side hydraulic pressure is swept up as a result of an arithmetic operation in torque phase speed change control. Disengagement side hydraulic pressure is calculated by initial speed change control, dependent on the engagement side hydraulic pressure. The engagement side hydraulic pressure is directly controlled and the disengagement side hydraulic pressure is indirectly controlled, i.e. responsive to the engagement side control. Consequently, the same control scheme can be executed regardless of power-on state or power-off state and regardless of vehicle operating conditions.
摘要:
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.
摘要:
In power-on, high-vehicle-speed and high-torque conditions, a control unit sets a torque allotment ratio such that a main clutch bears all the torque. Thereby, the input shaft rotational speed is increased by controlling solely the main clutch releasing pressure. In power-on and low-torque or low-vehicle-speed conditions, the control unit sets a torque allotment ratio for the main clutch torque and the sub-clutch torque to 1:1. Thereby, control of the main clutch releasing pressure and control of the sub-clutch engaging pressure simultaneously proceed in parallel to produce a change in the input shaft rotational speed without a time lag. The hydraulic control apparatus thus conducts proper downshift control for a shift involving clutch engagement changeover, under all vehicle running conditions, without need for additional control logic.
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:
A hydraulic pressure control apparatus for an automatic transmission including a microprocessor-based control unit for controlling hydraulic pressure supplied to hydraulic servos of friction engagement elements. The control apparatus calculates a target hydraulic pressure P.sub.TA for a condition at the start of the inertia phase in accordance with the input torque, and a gradient based on the target hydraulic pressure and a predetermined time t.sub.TA. A first up-sweep of hydraulic pressure is performed by the apparatus with the gradient. A relatively gradual gradient .delta.P.sub.TA is set based on a target rotation change rate for the input rotational speed to provide a predetermined change amount when the hydraulic pressure becomes the target hydraulic pressure P.sub.TA. The control apparatus performs a second up-sweep with the gradient .delta.P.sub.TA. When the rotational speed change .DELTA.N of the input rotation becomes a rotation change start-determining rotational speed dN.sub.S, the control apparatus feedback-controls the hydraulic pressure with a predetermined gradient while referring to the input rotation change. Further, the control apparatus detects the target shift start time and the rotational speed change rate at the target shift start time to correct the target hydraulic pressure P.sub.TA, the gradient .delta.P.sub.TA of the second sweep section, and the target shift start time t.sub.aim.
摘要:
A learning controller makes learning correction based on a time tST between start of a shift control routine and detection of start of a change in rotational speed of the transmission input shaft and further based on the amount of rotational speed change &ohgr;S′ at the detected start of the rotational speed change. When the time tST is longer than a basic time and when the rotational change amount &ohgr;S′ is too large, it is determined that a servo piston has not been sufficiently advanced and the shift control is corrected so that the time tST is lengthened. When the time tST to the detected start of the rotational speed change &ohgr;S′ is too small, it is determined that, while the piston has been advanced properly, the target engagement pressure PTA in torque phase control is too low because of a miscalculation, and the shift control is corrected so that the target engagement pressure is raised.
摘要:
A system for control of the discharge pressure of an input clutch hydraulic servo at the time of a D→N shift, in which the peak value (DN_Omega_max) rate of change of the rotational speed of an input shaft increases if the initial value (DN sol Sweep Start SLT signal) of the pressure adjusting control becomes high or low. A convergence region (DN_Omega_limit_max) is provided. On the basis of comparison between the previous peak value (DN_Omega_max_ave1) and the present peak value (DN_Omega_max_ave2), and the direction of correction, the learning is performed in accordance with various maps in a direction toward the convergence region.
摘要:
A fluid pressure control device including a torque converter that is placed between a output shaft of an engine and an input shaft of a transmission, a mechanical oil pump that is driven by the output shaft, a clutch that directly engages the output shaft and the input shaft by employing an engagement pressure based on a fluid pressure that is generated by the mechanical oil pump, an electric oil pump that can supply a fluid pressure to the clutch, and a control unit for controlling the electric oil pump, wherein when the engagement pressure based on the fluid pressure that is generated by the mechanical oil pump is an amount below a necessary engagement pressure that is necessary to engage the clutch, the control unit drives the electric oil pump so as to supply a fluid pressure by at least the amount to the clutch.
摘要:
An apparatus is provided which is to be used in producing single crystals for silicon wafers useful as semiconductor materials and which can stably produce large-diameter, long-length and high-quality single crystals from which wafers limited in the number of grown-in defects can be taken. This silicon single crystal production apparatus comprises a cooling member surrounding the single crystal to be pulled up and having an internal surface coaxial with the pulling axis and thermal insulating members disposed outside the outer surface and below the bottom surface of the cooling member, the cooling member having an internal surface diameter of 1.20D to 2.50D (D being the diameter of the single crystal to be pulled up) and a length of not less than 0.25D, the distance from the melt surface to the bottom surface of the cooling member being 0.30D to 0.85D and the bottom side of the thermal insulating member below the cooling member having an inside diameter smaller than the inside diameter of the bottom of the cooling member.
摘要:
A control apparatus for a vehicle which executes an automatic stop control of an engine on the basis of a stop condition, and executes a restart control of the engine on the basis of a start condition. The vehicle includes an engagement element which freely interrupts and establishes power transmission between an output of the engine and a drive wheel, a hydraulic servo which freely operates an engagement state of the engagement element and a control unit which executes a feedback control for bringing a hydraulic pressure of the hydraulic servo into a state immediately before the frictional engagement element is engaged, on the basis of the engagement state of the engagement element wherein the control unit starts the feedback control after the hydraulic pressure of the hydraulic servo is controlled to a predetermined hydraulic pressure when the restart control of the engine is executed.