Aisin Seiki Kabushiki Kaisha

Toyota Jidosha Kabushiki Kaisha

Kabushiki Kaisha Toyota Chuo Kenkyusho

Osamu Komazawa

Yoji Kanada

Toshio Onuma

Shuuichi Buma

Hiroshi Kubo

Takashi Yonekawa

Hiroyuki Ikemoto

Katsuhiko Hattori

Kunihito Sato

Kazumi Ogawa

Shigetaka Isogai

Tsukasa Watanabe

Naoto Yumisashi

Kenji Fujiwaki

Kazuhiko Maeda

Takeshi Hashizume

Masahiro Fukuta

Shinji Matsuda

Sigetaka Isogai

A variable valve timing control device includes a driving side rotational member () synchronously rotating with a crankshaft, a driven side rotational member () positioned coaxially with the driving side rotational member, and synchronously rotating with a camshaft, a fluid pressure chamber (), formed in at least one of the driving side rotational member and the driven side rotational member, for generating a biasing force for changing a relative rotational phase between the driving side rotational member and the driven side rotational member by hydraulic fluid supplied into or discharged from the fluid pressure chamber, a lock mechanism () movable between a lock position for preventing a relative rotation between the driving side rotational member and the driven side rotational member and a lock release position for allowing the relative rotation, a lock release pressure chamber () for generating a biasing force to move the lock mechanism () to the lock release position by supply of the hydraulic fluid, a phase control device () for controlling a rate of the relative rotational phase change by controlling supply or discharge of hydraulic fluid into or out of the fluid pressure chamber, and a lock control device () for controlling supply or discharge of hydraulic fluid into or out of the lock release pressure chamber, wherein the phase control device restricts an upper limit of the rate of the relative rotational phase change when the lock control device supplies hydraulic fluid to the lock release pressure chamber.

Variable valve timing control device

A valve timing control apparatus for controlling an opening and closing timing of a valve of an internal combustion engine includes a driving side rotational member synchronously rotated with a crankshaft, a driven side rotational member provided coaxially with the driving side rotational member and synchronously rotated with a camshaft, a fluid pressure chamber being separated into an advanced angle chamber and a retarded angle chamber, a phase control apparatus for displacing a relative rotational phase between the driving side rotational member and the driven side rotational member, a locking mechanism having a movable member, a judging device for judging a supply condition of the operation fluid relative to the fluid pressure chamber, and a control device for controlling a rotational speed of the crankshaft.

Valve timing control apparatus for internal combustion engine

In a valve timing control apparatus, a relative rotational phase between a drive rotational member rotated with a crankshaft and a driven rotational member rotated with a camshaft is controlled by a relative rotational phase-controlling mechanism utilizing a fluid pressure in a fluid pressure chamber divided by a vane. The relative rotational phase can be restrained by a locking mechanism at an intermediate phase between most advanced and most retarded angle phases. As a minimum set torque applied by a biasing mechanism to the drive rotational member relative to the driven rotational member, a larger minimum torque required for change from the most retarded angle phase to the intermediate phase during cranking, at a temperature before warming up while fluid pressure is discharged, or at a minimum temperature for relative rotational phase control while a fluid pressure remains, is selected.

Valve timing control apparatus and method for setting minimum torque

A variable valve timing control device which includes a driving side rotational member, a driven side rotational member, a rotational phase holding mechanism for holding a relative rotational phase between the driving side rotational member and the driven side rotational member at a locked phase, a rotational phase restriction mechanism for allowing and restricting the relative rotation, a groove formed at one of the rotational members, a restriction body provided at the rotational phase restriction mechanism for restricting the relative rotation, a plurality of said rotational phase restriction mechanisms for restricting the relative rotation in a predetermined direction at different relative rotational phases, a step portion provided at the groove being engaged with the restriction body for restricting the relative rotation in the predetermined direction, and the rotational phase restriction mechanism including the step portion for restricting the relative rotation in the predetermined direction at the plural relative rotational phases.

A variable valve timing control device includes a drive member rotatable in synchronization with a crankshaft, a rotatable driven member connected to a camshaft arranged co-axially with the drive member, a hydraulic chamber formed at one of the drive member and the driven member, a vane dividing the hydraulic chamber into an advanced angle chamber and a retarded angle chamber, a relative rotation phase controlling mechanism which controls a relative rotation phase between the drive member and the driven member between a most retarded angle phase in which a volume of the advanced angle chamber is a maximum and a most advanced angle phase in which a volume of the retarded angle chamber is a maximum by supplying or discharging operation fluid to and/or from the advanced angle chamber and the retarded angle chamber, a lock mechanism which restricts relative rotation between the drive member and the driven member, when the relative rotation phase is a predetermined lock phase between the most advanced angle phase and the most retarded angle phase, a control mechanism performing an intermediate phase operation upon input of a signal indicating engine stop to position the relative rotation phase intermediate between the most advanced angle phase and the most retarded angle phase by operating the relative rotation phase controlling mechanism, and performing a drain operation to drain the operation fluid from both the advanced angle chamber and the retarded angle chamber after performing the intermediate phase operation.

Valve timing control device

A variable valve timing control apparatus includes a relative rotation control mechanism and a fluid pressure passage. The relative rotation control mechanism restrains a relative rotation between a rotor and a housing at an intermediate phase position between the most advanced angle phase position and the most retarded angle phase position. The fluid pressure passage includes a first fluid path for supplying the fluid to the relative rotation control mechanism and for draining the fluid therefrom and a second fluid path for supplying the fluid to an advance angle chamber and a retard angle chamber and for draining the fluid therefrom. The first fluid path is defined independently of the second fluid path.

Variable valve timing control apparatus

A valve timing control device is provided, which has an advantageous point of locking a relative rotation phase at an intermediate phase based on an engine halt signal. The valve opening-closing timing control device has a relative rotation control mechanism including the first path for supplying or discharging oil to or from the retard angle chamber and the advance angle chamber and for moving a relative rotation phase between the retard angle chamber and the advance angle chamber in the range between the most retarded angle phase and the most advanced angle phase. The relative rotation control mechanism has a lock oil passage for actuating lock portions for locking the relative rotation phase at the intermediate phase between the most retarded angle phase and the most advanced angle phase. The second path is provided separately from the first path. The second path supplies oil to and discharges oil from a lock oil passage. ECU outputs, based on an engine halt signal, a command for discharging oil of the retard angle chamber and the advance angle chamber through the first path and for performing a main drain operation for discharging oil of a lock oil passage through the second path.

A variable valve timing control device includes a relative rotation control mechanism restricting relative rotation between the housing member and the rotor member at an intermediate phase position between a most advanced angle phase position and a most retarded angle phase position, and a hydraulic pressure circuit which controlling supply and discharge of operation fluid with respect to advance and retarded angle hydraulic chambers while also controlling supply and discharge of operation fluid for the relative rotation control mechanism. The hydraulic pressure circuit includes a variable type spool valve adapted to discharge the operation fluid from the advance and retarded angle chambers and from the relative rotation control mechanism. The variable type spool valve has different discharge opening widths at a both drain function region in which the operation fluid can be drained from the advanced and retarded angle hydraulic chambers.

A variable valve timing system includes a first controlling mechanism through which operation fluid is supplied to and discharged from an advanced angle chamber to restrict the relative rotation to an advanced angle side at the lock phase, and a second controlling mechanism through which operation fluid is supplied to and discharged from a retarded angle chamber to restrict the relative rotation to a retarded angle side at the lock phase. The variable valve timing system further includes passages which function as a throttle at the lock phase to connect the advanced angle chamber with the first controlling mechanism and the retarded angle chamber with the second controlling mechanism.

Variable valve timing system

A variable valve timing system includes a relative rotation controlling mechanism restricting relative rotation of a housing member and a rotor member at the intermediate lock phase between the most advanced angle phase and the most retarded angle phase. An auxiliary controlling mechanism actuated in response to the operation fluid to be supplied to and discharged from a fluid pressure circuit allows the relative rotation of the housing member and the rotor member under the unlock condition and restricts the rotation of the rotor member to the retarded angle side or to the advanced angle side relative to the housing member at a set phase between the most retarded angle phase or the most advanced angle phase and the intermediate lock phase under the lock condition.

A variable valve timing system includes a hydraulic pressure circuit for controlling an operation fluid supply/discharge of the relative rotation controlling mechanism and for controlling an operation fluid supply/discharge of each of the advanced angle chamber and the retarded angle chamber. The hydraulic pressure circuit, upon initiation of the internal combustion engine, discharges the operation fluid from the relative rotation controlling mechanism and the advanced and retarded angle chambers until a pressure of the operation fluid reaches a controllable pressure value. The hydraulic pressure circuit, after the pressure of the operation fluid reaches the controllable pressure value, effecting filling of one of the advanced and retarded angle chambers which is at the superior side of in phase transfer response with operation fluid, subsequently effecting filling of the other of the advanced and retarded angle chambers, and being adapted to supply the operation fluid to the relative rotation controlling mechanism.

A pressure control valve delivers a pressure which is proportional to a current level chosen to energize a solenoid therein to a shock absorber of a suspension. A spool in the valve has an annular groove for communicating an output port to a high pressure port or a low pressure port selectively. There are conical surfaces or inclined surfaces at edges of lands adjacent to the groove, which incline from annular surfaces of the lands toward the bottom of the groove. The inclined surfaces slow down a change of the flow rate from the high pressure port to the output port and from the output port to the low pressure port when the annular groove communicates with the high pressure port and the low pressure port respectively.

Pressure control valve device

In a hydraulic suspension system, a plurality of actuators having working fluid chambers are provided. Each actuator is adapted to increase and decrease vehicle height as the results of the supply and the discharge of working fluid into and from its working fluid chamber, respectively. A plurality of accumulators are connected with associated working fluid chambers. Working fluid supply passages supply working fluid into the working fluid chambers and working fluid discharge passages discharge working fluid from the working fluid chambers. Pressure control devices are provided in the supply passages and the discharge passages. Each pressure control device means is adapted to control the supply of the working fluid into and the discharge from the associated working fluid chamber to adjust the pressure within the chamber. The suspension system further comprises flow resistance control devices. Each flow resistance control devices is adapted to adjust at least one of the first flow resistance between the associated working fluid chamber and the associated accumulator and the second flow resistance of the associated discharge passage in response to the flow rate of the working fluid discharging through the discharge passage so that the higher the discharging flow rate is, the higher the ratio of the second to the first flow resistances may be, not only to reduce the flow rate of the working fluid discharging from the working fluid chamber through the discharge passage but also to increase the flow rate of the working fluid flowing into the accumulator from the working fluid chamber.

Hydraulic suspension system for a vehicle

A pressure control system for suspension delivers a pressure which is proportional to a current level chosen to energize a solenoid of a pressure control valve to a shock absorber of a suspension. A change in the pressure of a return path which supplies a low pressure to the pressure control valve causes the pressure which is applied to the suspension to change. In order to suppress such change, a junction of the pressure control valve with the return path has an orifice interposed therein or is connected to a low pressure accumulator. On the other hand, in the event a depression occurs in the output of the high pressure piping, a cut valve which functions to isolate the suspension from the pressure control valve may be temporarily cut off in response to a pressure fluctuation in the high pressure piping. In order to prevent this, an orifice is interposed between the high pressure piping and a pilot chamber of the cut valve.

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Chita, Japan

Osamu Komazawa