Abstract: A brake band drum for a planetary gear-type automatic transmission in which a clutch is formed inside a press-manufactured planetary gear input member coupled to a press-manufactured clutch cylinder and one member of a planetary gear mechanism, and a band brake is arranged on the outer peripheral side of the clutch cylinder or planetary gear input member, characterized in that the clutch cylinder or planetary gear input member is fitted by being splined, and an engaging surface of the band brake is formed on an outer peripheral surface of the clutch cylinder or planetary gear input member. Thus, the brake band drum is formed by fitting the brake band drum and clutch cylinder together. This makes it possible to dispense with electron beam welding. As a result, costs and weight can be reduced.
Abstract: A reverse shift control device of an automatic transmission prevents reverse running of the automatic transmission, even though a manual shift lever is set to a reverse range, when the vehicle runs at more than a predetermined speed. Certain shift valves have ports to which line pressure is applied from the manual valve when set to reverse, and also have ports which communicate with a hydraulic servo of a frictional engaging component which is engaged when the vehicle travels in reverse. When the manual valve is set to reverse and the vehicle speed is more than a predetermined speed (for example, 7 km/h), respective pairs of the ports are disconnected due to the shifting of the shift valves based on the signal issued by a controller.
Abstract: If a driver wishes to start off an automotive vehicle in second or third gear when the vehicle is at rest on a road surface having a low coefficient of friction, as is the case when a road surface is covered with snow, the driver operates a winter mode selection switch while the transmission is in the speed range in which the vehicle ordinarily travels, i.e. the D range. After the vehicle has started off in the higher gear following use of the switch, the transmission switches over to the ordinary travel mode automatically as vehicle velocity rises. In a case where the engine is turned off and then restarted, the transmission switches over to the ordinary travel mode automatically. This eliminates any inconvenience that might be caused by forgetting to operate the switch prior to the restarting of the engine.
Abstract: An automatic transmission comprising a single planetary gear unit and a dual planetary gear unit has an output member located in its center so that the output member encloses an input shaft.In the case of a three speed automatic transmission mechanism, a first clutch located around a ring gear of the single planetary gear unit connects the input shaft to this ring gear.In the case of a four speed automatic transmission mechanism, a third clutch which actuates overdrive is additionally located axially outside the first clutch for connecting the input member to a ring gear of the dual planetary gear unit.A sun gear common to both planetary units is connected to the input shaft by a second clutch. This clutch has a drum portion upon which a band may act to brake the sun gear.
Abstract: A road image input system for controlling an automotive vehicle includes a pick-up mounted on the vehicle for picking up the image of a road ahead of the traveling vehicle, a sensor for sensing the traveling condition of the vehicle, and an image processor for obtaining information indicative of the road by setting an image processing window on the image which has been picked up and processing data contained within the image processing window. The image processing window is set at a position based on values of the vehicle velocity and the steering angle of the steering wheel.
Abstract: A lubrication system is provided for a transmission mechanism supported on input and output shafts, and a chain drive rotatably connects these shafts. The chain and drive elements on the shafts are provided with a casing for isolating the mechanism, which collects an oil bath within the bottom of the transmission casing for lubricating a chain or other transmission member. An oil pump supplies oil from a reservoir to various areas to be specifically lubricated within the transmission. Feed means associated with the oil pump regulates the level of the transmission oil bath. The system may additionally contain an oil strainer, an external cooler, a relief valve to limit the pressure from the oil pump, or various combinations of such elements. The various points of lubrication within the casing, in turn, drain into the casing. Oil level within the transmission casing is regulated to keep the level low and at the same time to maintain sufficient oil for lubricating the chain.
Abstract: A rate of change in vehicle velocity is calculated by comparing a present vehicle velocity signal and an immediately preceding vehicle velocity signal. If the rate of change in vehicle velocity is greater than a rate of change capable of being produced by actual traveling of the vehicle, a decision is rendered to the effect that the vehicle velocity sensor is faulty, fail-safe mode processing is executed and the automatic transmission is controlled in such a manner that traveling of the vehicle will not be impaired. Thus, if the vehicle velocity sensor malfunctions, the automatic transmission can be controlled so as not to impair traveling of the vehicle, thereby allowing the vehicle to travel safely and stably. The fail-safe function can be performed satisfactorily even if only a single vehicle velocity sensor is provided.
Abstract: Automatic transmission including a main-transmission-mechanism consisting of two planetary gear units (three speed or four speed transmission mechanism for example) and a sub-transmission-mechanism consisting of one planetary gear unit (underdrive mechanism, for example). One speed and two speed for the whole transmission are obtained, with a low speed stage of the main-transmission-mechanism lower than two speed, by shifting the main-transmission-mechanism to one and two speed, respectively, while the sub-transmission-mechanism is kept at low speed (underdrive). And three speed for the whole transmission is obtained by shifting the sub-transmission-mechanism to high speed (direct coupling) while the main-transmission-mechanism is left at the two speed state. Further, four speed or five speed for the whole is obtained by shifting the main-transmission-mechanism to three speed or, if it is of four speed type, to four speed, respectively, while the sub-transmission-mechanism is kept at the high speed state.
Abstract: An automatic transmission has a main transmission mechanism having two planetary gear units made on a first axle, and a sub transmission mechanism having two planetary gear units made on a second axle; the main transmission mechanism having a single planetary gear unit and dual planetary gear unit, carriers of the gear units being connected to one another and sun gears of the gear units being connected one another, an input member connecting a ring gear of the single planetary gear unit through a first clutch, and connecting a sun gear through a second clutch, a brake restraining the sun gear and a ring gear of the dual planetary gear unit at a required moment; the main transmission mechanism having three forward speeds and one reverse speed. A fourth clutch may be added which connects an input shaft and the ring gear of the dual planetary gear unit, so that four forward speeds and one reverse speed are obtained. The sub transmission mechanism has three forward speeds.
Abstract: A four-wheel drive vehicle having a front- and rear-wheel engaging mechanism designed to enable differential limiting means provided between the front and rear wheels to be controlled over the range from the direct coupling position to the disengaged position through the slip region by the control of the degree of engagement. The vehicle is provided with engaging means for driving the front- and rear-wheel engaging mechanism at a set degree of engagement, detecting means for detecting a running condition, and control means for setting a degree of engagement to control the engaging means. The control means has reference data concerning degrees of engagement respectively corresponding to various running conditions, and sets a degree of engagement selected from the reference data in accordance with the detected running condition. Thus, it is possible to engage the front- and rear-wheel engaging mechanism in such a manner as to prevent the occurrence of tight corner braking while avoiding slipping.
Abstract: A hydraulic control device for an automatic transmission, having a gear ratio different from that of usual D range by a manual shift down from the D range to range 3 or 2, is mounted on an automobile. A first solenoid valve, a first shift valve and a second shift valve are connected so that the first solenoid valve controls the first and second shift valves. A second solenoid valve, a third shift valve and a down shift control valve are connected so that the second solenoid valve controls the third shift valve and the down shift control valve. Oil paths through which line pressure is applied in accordance with the range at which the manual valve is set are connected to certain shift valves, so that motions of the valves in the shift valves and the down shift control valve are constrained in accordance with the set range of the manual valve.
Abstract: An automatic transmission for motor vehicles, including a first shaft rotatably supported by the automatic transmission case and consisting of an input shaft coupled with the engine output shaft through a joint like a fluid joint or a friction clutch and an output shaft disposed in series and coaxially with the input shaft and mounting an output gear; a second shaft consisting of a long shaft rotatably supported by the transmission case parallel with the first shaft and a short shaft rotatably mounted on the long shaft, one of the long and short shafts having an input gear connected to the output gear of the first shaft by direct meshing engagement therewith or through a chain or an idler gear while the other one having an output gear mounted thereon; a differential having a large drive gear connected to the output gear of the second shaft by direct meshing engagement therewith or through a chain or an idler gear; a first speed-changing planetary gear mechanism provided between the input and output shafts of
Abstract: In accordance with the invention, as shown, for example, in FIG. 1, when a second counter 14 attains a number of pulses n needed for period measurement, the time required for n pulses to enter is obtained from a second memory 16, which stores the time that prevailed n pulses ago, and a first memory 15, which stores the time prevailing when the present velocity signal enters. Vehicle velocity is calculated from the time obtained. A second timer 11 is reset whenever the velocity signal enters in order to check the pulse input time interval. When the value in the second timer 11 exceeds a predetermined value t, the second counter 14 is reset in order to remeasure the time required for the n pulses to enter. Thereafter, the contents of the first memory 15 are stored in the second memory 16 and the second timer 11 is also reset.
Abstract: An actuator for a four wheel drive transfer mechanism which is laid in a power transmission device and is controlled by an electrical signal sent from a controlling unit comprises a torque generating mechanism which converts electrical energy into a torque, and a torque-thrust conversion mechanism which converts the torque generated by the torque generating mechanism into a thrust force. The thrust force generated from the torque-thrust conversion mechanism is applied to the frictional engaging device to control torque distribution between front and rear vehicle wheels.
Abstract: In a dual planetary gear of an automatic transmission, tooth surface pressure generated at a relatively short pinion is decreased and distributed since the pinion is formed as a pair of pinions. These pinions can be pinions which mesh with a sun gear or pinions which mesh with a ring gear and a single first pinion. Torque exerted on the ring gear (or the sun gear) is transmitted to the sun gear (or the ring gear) through one point of contact (or two) between the sun gear and one pinion (or a pair of pinions) and the ring gear and two points of contact (or one) between a pair of pinions (or one pinion) and the ring gear.
Abstract: A hydraulic servo regulating device of an automatic transmission, which according to the present invention applies enough line pressure quickly to a hydraulic servo and obviates a delay when the line pressure is to be drained, is disposed in an oil path between a shift valve and an accumulator. The device employs regulator valve which has an application port connected to a shift valve, a regulating port in selective communication with the application port, a first feedback port through which feedback pressure is applied to one end of a spool, a second feedback port through which feedback pressure is applied to the other end of the spool, a spring and a drain port connected to the regulating port. Furthermore, the regulating port communicates with a hydraulic servo through a first oil path, and an accumulator chamber through a second oil path having an orifice and branched off from the first oil path.
Abstract: An automatic transmission having Ravigneaux Type planetary gear unit comprises a first and a second sun gear, a long pinion meshing the first sun gear, a short pinion meashing the long pinion and the second sun gear, a carrier supporting the long pinion and the short pinion and a ring gear meshing the long pinion;the input shaft connects the second sun gear through a first clutch, and connects the first sun gear through a second clutch;the output member is located in the center of the automatic transmission mechanism so that the output member encloses the input shaft;in case of three speed transmission mechanism, a first clutch is located axially and extreme outside the transmission mechanism;in case of four speed transmission mechanism a third clutch is located axially and outside the first clutch.
Abstract: A lockup control valve is provided to control the discharge from the lockup clutch during clutch engagement and a solenoid valve to supply the control pressure to the lockup control valve. The aforesaid lockup control valve has a face on which the oil supply pressure acts during lockup clutch engagement, an opposing face of equal area on which the lockup clutch discharge pressure acts, a face on which the supply pressure from the aforesaid solenoid valve acts, and an opposing face on which a constant pressure acts. The hydraulic controlling system controls the discharge pressure of the lockup clutch during lockup clutch engagement according to the control pressure from the solenoid valve. This maintains a constant relationship between the solenoid pressure and the lockup clutch capacity (pressure difference) and permits precise slip control even if the oil pressure supplied to the lockup clutch fluctuates.
Abstract: A manual valve which is used for an automatic transmission is designed to be shortened axially.A port for reverse running and the ports for forward running are made on the same axial direction against ports for the port for line pressure application.A spool has; a first oil chamber which connects the port for line pressure application and the ports for forward running, a second oil chamber which connects the port for reverse running and the port for line pressure application or a drain hole, and a drain path connecting the ports for forward running and the drain portion.
Abstract: A sensed shift time and a standard value of shift time set for this shift are compared. If the result of the comparison is that the shift time does not fall within an allowable range of standard values, a signal outputted to a linear solenoid is varied in such a manner that the shift time will be held with the range of the standard values. Accordingly, actual shift time while a vehicle is traveling is constantly fed back and controlled so as to attain an optimum shift time. Therefore, even if a change in the shift time is brought about by a change in oil temperature in the transmission or by aging of friction elements or the like, the shift time can be corrected to an optimum value to improve shift sensation as well as the durability of the friction elements.