Honda Giken Kogyo Kabushiki Kaisha

Noboru Sekine

Takamichi Shimada

Takashi Aoki

Sadanori Nishimura

Satoshi Terayama

Hiroyuki Shimada

Yoshihisa Iwaki

Sachito Fujimoto

Tatsuyuki Ohashi

Shigeru Kanehara

Hideaki Yoshida

Yoshimi Sakurai

Junichi Miyake

Tsunefumi Niiyama

Hideki Wakamatsu

Shuichi Fujimoto

Keiichi Ishikawa

Yasuo Kima

Hisashi Kunii

Shigeo Ozawa

Hitoshi Yamabe

Keiichi Hanyu

Kazumi Sato

Nobuo Takemasa

Shuichi Takagi

Kaoru Kajikawa

Yoshiyuki Ura

Yoshihiro Yoshimura

Hideki Kuratsu

Takabumi Sakai

Yutaka Yamamoto

Tatsuyuki Ohhashi

A shift control system for an automatic transmission comprises a shift lever , which is shifted among a &ldquo;P&rdquo; position, an &ldquo;N&rdquo; position and an &ldquo;S&rdquo; position. A first shift guide path is provided to guide the shift lever from the &ldquo;P&rdquo; position through the &ldquo;N&rdquo; position to the &ldquo;S&rdquo; position, and a second shift guide path is provided to guide the shift lever which has been positioned at the &ldquo;S&rdquo; position in a direction different from that of the first shift guide path. Along this second shift guide path, the shift lever is shifted to select and set a plurality of ranges necessary for driving a vehicle, including a forward drive range, a neutral range and a reverse drive range.

Shift control system for vehicular automatic transmission

A system for controlling gear (gear ratio) shifting in an automatic transmission mounted on a vehicle, including a shift control means for generating a shift command to upshift from one gear (gear ratio) currently established to a next gear (gear ratio) by determining a command to the solenoid valves to discharge the pressurized oil from the frictional engaging elements that establish the current gear (gear ratio) so as to slip-control the frictional engaging elements, and to charge the pressurized oil to the frictional engaging elements that establish the next gear (gear ratio) to be shifted to. The system includes a first step for determining the command such that an actual slip rate of the frictional engaging elements that establish the current gear (gear ratio) converges to a first desired slip rate, a second step for determining the command such that the actual slip rate of the frictional engaging elements that establish the current gear (gear ratio) converges to a second desired slip rate, maximum slip rate detecting means for detecting a maximum actual slip rate, slip rate difference calculating means for calculating a difference between the detected maximum actual slip rate and the second desired slip rate, command correcting means for correcting the command in response to the calculated difference, and command storing means for storing the corrected command to be used as the command in the first step in controlling a next upshift. This arrangement can avoid the clutches (and brakes) from being suffered excessive slippage, thereby improving the service life of the clutches and brakes and making the control to smooth shift to that for the next gear (gear ratio).

Gear ratio shift control system for automatic vehicle transmission

A shift control for a shift-down operation is executed by carrying out the following stages in order: an off-going range releasing stage STO1 which quickly lowers the engagement actuation pressure of the off-going engaging element to an engagement-releasing pressure; an off-going range controlling stage STO2, STO3 and STO4 which sets the engagement actuation pressure of the off-going engaging element to a pressure a little higher than the engagement-releasing pressure; an on-coming range void-stroke-clearing stage STR1 which sets the engagement actuation pressure of the on-coming engaging element to a predetermined high-pressure necessary for clearing the void stroke; an on-coming range waiting stage STR2 and STR3 which sets the engagement actuation pressure of the on-coming engaging element to a stand-by pressure necessary for retaining the on-coming engaging element in stand-by condition prior to engagement; an off-going range final stage which releases the off-going engaging element completely; and an on-coming range final stage which engages the on-coming engaging element completely.

Shift control method for an automatic transmission based upon slippage

A control for shifting from an off-going speed range to an on-coming speed range comprises an off-going range releasing stage, an on-coming range void-stroke-clearing stage, an on-coming range engaging stage and an on-coming range final stage. During the off-going range releasing stage, an off-going engaging element is released in response to a shift command signal. During the on-coming range void-stroke-clearing stage, the engagement-actuation pressure of the on-coming engaging element is set at a predetermined high-pressure for a predetermined time period after the shift command signal is generated, whereby the void stroke of the on-coming engaging element is cleared. During the on-coming range engaging stage, after the completion of the on-coming range void-stroke-clearing stage, the on-coming engaging element is engaged. During the on-coming range final stage, following the on-coming range engaging stage, the on-coming engaging element is engaged completely. In this control, based on the condition of the engaging operation of the on-coming engaging element during the on-coming range engaging stage, the predetermined time period for the on-coming range void-stroke-clearing stage is corrected for a next shift operation.

Shift control method for automatic transmission

An automatic transmission includes a plurality of power transmitting gear trains making up a combination of forward power transmitting paths that can be selected one at a time, a plurality of frictional engaging elements for selecting one of the forward power transmitting paths at a time, and a one-way clutch for establishing a lowest-speed gear position among the forward power transmitting paths. When a gear shift is to be made from a neutral gear range to a forward gear range, one of the frictional engaging elements which is mechanically coupled to the one-way clutch is preliminarily engaged. When the gear shift can be made from the neutral gear range to the forward gear range, one of the frictional engaging elements for establishing the starting gear position starts being engaged, and thereafter those frictional engaging elements which are not necessary to establish the starting gear position are released. Because the frictional engaging element is mechanically coupled to the one-way clutch is preliminarily engaged, vibrations produced upon rotation of the one-way clutch are reliably suppressed when the gear shift is made from the neutral gear range to the forward gear range.

Apparatus for controlling gear shift in automatic transmission

A shift control method for executing a shift-up control from an off-going range to an on-coming range comprises an off-going-range releasing stage, an off-going-range controlling stage, and an on-coming-range invalid-stroke-clearing stage. In the off-going-range releasing stage, a pressure command signal is generated to quickly lower the engagement-actuation pressure of the off-going engaging element. In the off-going-range controlling stage, a pressure command signal is generated to control the engagement-actuation pressure of the off-going engaging element in such a way that the off-going engaging element is kept slipping within a predetermined range of input/output rotational speed ratio (=output rotational speed/input rotational speed). In the on-coming-range invalid-stroke-clearing stage, a pressure command signal is generated to set the engagement-actuation pressure of the on-coming engaging element to a predetermined high-pressure which is necessary for the on-coming engaging element to clear its invalid stroke. This shift-up control initiates the on-coming-range invalid-stroke-clearing stage in response to a shift-up command and proceeds from the off-going-range releasing stage to the off-going-range controlling stage when the input/output speed ratio of the off-going engaging element reaches a first predetermined value in the off-going-range releasing stage. Then, pressure command signals are generated sequentially first to engage the on-coming engaging element in a predetermined engaging pattern and then to completely release the off-going engaging element.

An engagement-actuation control for a frictionally engaging element to establish a driving range in response to a shift command to shift from a neutral range to the driving range comprises a plurality of control stages including an invalid-stroke-clearing control. This invalid-stroke-clearing control is finished when invalid-stroke clearing is judged complete on the basis that the absolute value of the rate of rotational change of a turbine shaft is equal to or greater than a predetermined rate and that the difference between the rotational speed of an engine and the rotational speed of the turbine shaft is equal to or greater than a predetermined value.

Shift control apparatus for automatic transmission

A shift control apparatus controls the shifting of a transmission by selecting one power transmitting path at a time from a plurality of paths respectively having different speed reduction ratios. At least one power transmitting path is provided with a one-way clutch and an engine-brake clutch is included in the plurality of paths. The one-way clutch can be locked by the engine-brake clutch. An engine-brake clutch control valve is provided for controlling the engine-brake clutch. Two solenoid valves are provided for controlling the engine brake clutch control valve. When one of the two solenoid valves fails and is inactivated, the other solenoid valve is used to cause the engine-brake clutch control valve to engage the engine-brake clutch.

Transmission with one-way clutches and failsafe method of and apparatus

A metallic V belt for use in a V-belt-type continuously variable transmission has an endless metallic belt strap and a plurality of metallic blocks each having a strap insertion slot defined therein and opening outwardly of the V belt at one side of the metallic block, the metallic blocks being mounted on that belt strap with the belt strap positioned in the strap insertion slots in the metallic blocks. A retaining belt strap or retainer is disposed in engagement with portions of the metallic blocks in covering relation to the endless belt strap in the strap insertion slots for retaining the metallic blocks against dislodgment from the belt strap. The retainer is in the form of an endless web having a flat transverse cross section and having at least one hole defined in the endless web. The hole in the endless web may be a slot, a narrow slit, or an elliptical hole.

Metallic V-belt

When a gearshift command for a power-on/downshift or power-off/upshift mode is issued, the magnitude of a change in the engine rotational speed due to the gearshift is calculated from the vehicle speed or the engine rotational speed when the gearshift starts to be effected and the gear ratio of a gear position to be reached by the gearshift. If the magnitude of the engine speed change is large, then a hydraulic control pressure is lowered for a certain period of time to advance the timing of operating of a hydraulic pressure release valve to quickly disengage a previous-gear-position clutch. If the magnitude of the engine speed change is small, then the control pressure is increased to delay the timing of operation of the hydraulic pressure release valve to allow the previous-gear-position clutch to be disengaged after a next-gear-position clutch starts to be engaged.

Apparatus for controlling gearshifts in automatic transmission

A controller for an automatic transmission hydraulic clutch includes a hydraulic clutch engaged by hydraulic pressure, a hydraulic pressure control valve for regulating the hydraulic pressure, and a detector for detecting a condition immediately before engagement of the hydraulic clutch based upon a change in the hydraulic pressure. A timing controller adjusts timing to change a control force in the hydraulic pressure control valve in response to detection of a condition immediately before engagement of the clutch.

Apparatus for and method of controlling hydraulic clutch operation in an

A fuel supply control method for an engine having a fluid torque converter with a clutch for mechanically connecting the input and output sides of the fluid torque converter wherein the clutch is engaged and the fuel supply to the engine is stopped during speed reduction when the engine speed or the vehicular speed is over a predetermined value under a no load condition of the engine, such as during deceleration from a high speed. In the present method the clutch is released first at a predetermined speed and then the fuel supply to the engine is restarted when the speed, either engine speed or vehicular speed, drops below the first predetermined speed.

Fuel supply control method for an engine with a fluid torque converter

A clutch control method for a fluid torque converter of a vehiclar transmission which has a clutch for mechanically connecting the input and output sides of the fluid torque converter within a predetermined vehicular speed range by such a relatively low engaging force as to allow slippage of said clutch. The control method includes a step of determining that the throttle opening of the engine has been decreased at a rate higher than a predetermined value and to a value lower than a predetermined reference throttle opening, even if the vehicular speed is within said predetermined range for allowing clutch slippage, and then increasing the engaging force of said clutch to a value higher than that for said reference opening to provide vehicle braking by the engine.

Clutch control method for fluid torque converter of vehicular

A gear-change apparatus for a vehicle transmission having multiple forward speed gear trains and one reverse gear train that is established by a slide meshing action of a reverse idler gear. A cam mechanism between the reverse gear shift fork and one of the forward gear shift forks causes that forward gear shift fork to move a small stroke toward gear engagement to engage the synchronizing mechanism to stop or reduce inertial rotation of components within the transmission without actually causing engagement of that forward gear, which function occurs just prior to actual engagement of the reverse gear train. A recess in the interlocking plate permits the small stroke of movement of the forward shift fork. In one embodiment the cam mechanism includes a one-way device to eliminate any substantial resistance to shifting the apparatus out of reverse gear.

Gear-change apparatus for vehicle transmission

A vehicular transmission having a fluid torque converter of the type in which a clutch is provided for mechanically connecting the input and output sides of a fluid torque converter above certain vehicle speeds for improved operation and economy and in which the clutch is operated within a predetermined vehicular speed range by such a relatively low engaging force as to allow slippage of said clutch for minimizing vibration. A control system causes the engaging force of the clutch to be increased more than that which is normally established below a reference value of small throttle valve opening for providing a braking effect by the engine. The control system also may provide for stopping the increase in engaging force at small throttle valve openings when the r.p.m. of the output side of the fluid torque converter falls below the r.p.m. at the input side, such as during a transition from a steep downward slop to a gentle downward slope, or when low oil temperature and high oil viscosity would cause operation too abruptly.

Growing community of inventors

Kasukabe, Japan

Noboru Sekine