Mitsubishi Denki Kabushiki Kaisha

Katsuyuki Fukuhara

Mutsuo Sekiya

Masafumi Sugawara

Hiroyuki Kinugawa

Makoto Yamauchi

Chikara Ueno

Hajime Kako

Satoshi Asada

Hirofumi Hase

A valve timing adjusting device has a lock mechanism for restricting a rotational motion of an internal rotor relative to an external rotor . The lock mechanism has a plunger , which is movable along a radial direction of the external rotor and restricts the rotational motion of the internal rotor relative to the external rotor on condition that the prevention of the rotational motion of the internal rotor relative to the external rotor is removable, a receiving hole , which is arranged on an outer circumferential surface of the internal rotor and receives the plunger , a spring , which presses the plunger inwardly along the radial direction of the external rotor by a prescribed pressure, a holder , which determines a position of the spring , and a knock pin which prevents the holder from being moved outwardly along the radial direction of the external rotor

Valve timing adjusting device

A valve timing control device is mounted on an end of a camshaft having a plurality of cams opening and closing an intake or exhaust valve of an internal combustion engine to modify timing for the opening and closing of the intake or exhaust valve by way of a tappet. The device includes a bias means biasing the camshaft in an advanced direction with a biasing force approximately equal to or smaller than a peak value of frictional torque produced between a cam of the camshaft and the tappet.

A valve timing control device includes a purge path communicating between a hydraulic chamber allowing the entry of hydraulic pressure on starting an engine and a backward pressurized section in an accommodation hole. When the hydraulic chamber allowing the entry of hydraulic pressure on starting the engine is the retardation side hydraulic chamber, a hydraulic pressure derived from an oil pump is supplied to the retardation side hydraulic chamber on starting the engine. On the way, air-mixed oil is discharged to outside of the device by way of a purge path, a backward pressurized section in the accommodation hole and the discharge hole. When the air is discharged, a residual pressure is produced in the backward pressurized section due to oil supplied thereto. The residual pressure results in the increase of an unlocking hydraulic pressure to prevent a locking member from being unlocked. When the application of a retardation side hydraulic pressure is switched to that of an advance side hydraulic pressure, the pressure presses a front end of a locking member against only a biasing force of a biasing means to unlock a locking relation. The valve timing control device allows the use of any kinds of locking pins, and prevents the occurrence of beat noise (abnormal noise) when air-mixed oil unlocks a locking relation on starting the engine.

Valve timing control device

A valve timing control device has a hydraulic pressure supply passage for supplying a hydraulic pressure used for releasing lock due to the lock member. If a hydraulic pressure applied to the hydraulic pressure supply passage reaches a required pressure, a hydraulic pressure subjected to a major diameter section of the lock member is larger than the sum total of the biasing force of two biasing members. Thus, the lock member is returned in a direction of releasing the lock due to the lock member. The sliding member is moved backward while the lock member is also moved backward. The stroke of the sliding member is extremely shorter than that of the lock pin. With a locked state of leaving the engagement of a minor diameter section of the lock member with an engagement hole, a rear end face of a minor diameter section of the sliding member abuts with a rear wall face of a backward pressure chamber. Thus, it is difficult that a backward pressure space defined between the lock member and the sliding member communicates with a discharge hole. Since the opening area of the discharge hole substantially is throttled, a speed of discharging the backward pressure is considerably delayed.

A valve timing control device has a lock pin for controlling the rotation between first and second rotors. A purge valve is arranged at the lock pin, the purge valve discharging air-mixing oil into a discharge hole in a release operation. On application of first pressure of release hydraulic pressure, a part of the first pressure is discharged through the purge valve, a backward pressure chamber and the discharge hole to the outside the device. Therefore, the lock pin is slid to reduce applied pressure, and it can delay a release operation to prevent the occurrence of beat noise on starting an engine.

A valve timing control device has a purge path arranged at a vane of a rotor provided with a valve. The purge path communicates a retardation side oil hydraulic pressure chamber with an accommodation hole. Oil pressure in the retardation side oil hydraulic pressure chamber is supplied through the purge path to the accommodation hole to generate oil pressure acting to delay a release operation.

The vane type hydraulic actuator according to the present invention comprises a guide locking mechanism (guide stopper pin) (,) for guiding the rotor (,) to a locking position where the rotor (,) can be locked to the case (,), and a retaining locking mechanism (retaining stopper pin) (,) for retaining the rotor (,) to the case (,), after the rotor (,) is guided to the locking position. The actuator having vanes, wherein the length in the peripheral direction of the tip portion of the vane having the locking mechanism is substantially identical to that of the vane which is located symmetrically thereto. The length in the peripheral direction of the tip portion of the other vanes is shorter than that of the vane having the locking mechanism.

Vane type hydraulic actuator

The vane type hydraulic actuator according to the present invention includes a guide locking device (guide stopper pin) (,) for guiding the rotor (,) to a locking position where the rotor (,) can be locked to the case (,), and are taining locking device (retaining stopper pin) (,) for retaining the rotor (,) to the case (,), after the rotor (,) is guided to the locking position.

A vane type hydraulic actuator, wherein a chip seal,, as a seal element between the case,and the rotor,can be pressed to contact tightly with the counter surface, without using a spring,as in the prior art, when a working oil is supplied either from the oil pressure chambers for timing retard or for timing advance. Simultaneously, the locking between the rotor,and the case,can be released. The hydrodynamic resistance at the gap between the tip of the seal element (chip seal),and the counter surface of the seal element is made larger than that at the gap between the flank of the seal element,and the flank of the seal groove,which accomodates the seal element, so that the working oil of the hydraulic actuator flows between the flanks. The working oil at the bottom of the seal element urges the seal element to contact tightly with the counter surface. An oil channel,connects the bottom of the seal groove and a stopper pin holding hole,which holds a stopper pin,pressed by a spring,When a working oil is supplied from either of oil pressure chambers for timing retard or advance, the channel,opens to supply a working oil into the stopper pin holding hole,so as to displace the pin against the biasing force of the spring,to release the suppression of rotation.

A hydraulic apparatus for adjusting the timing of opening and closing of an engine valve includes a cam shaft driven to rotate in synchronization with the engine rotation. An actuator is installed on the cam shaft for changing the timing of opening and closing of an intake valve and/or exhaust valve using a control of a working oil supply. A slidable plunger is disposed in the actuator, and a rotor is disposed in the actuator to engage with the plunger by an engaging hole. A spring urges the plunger to move into the engaging hole to make an engagement therebetween when the engine is stopped, and when the engine begins to run, the working oil is supplied into the engaging hole to push out the plunger from the engaging hole to release the engagement between a housing of the actuator and the rotor. The engaging hole and the plunger have a surface parallel with a slide direction of the plunger, and a clearance therebetween is smaller than 0.17 mm when the engaging hole and plunger engage each other.

Hydraulic apparatus for adjusting the timing of opening and closing of an engine valve

The valve timing adjusting apparatus comprises a bias means that generates an urging force between the casing and the rotor, and the thus generated urging force is set to the level equal to or below the average inertia torque of the camshaft within the time period until the spark ignition is generated after one rotation of the crank shaft at the starting time of the combustion engine, so that by the varied torque at the time of starting of the combustion engine and the urging force, the rotor can be rapidly shifted toward the advance side or retard side with a relatively small force, improving thereby the response characteristic of the valve opening/closing system.

Valve timing adjusting apparatus for internal combustion engine

A hydraulic apparatus for adjusting the timing of opening and closing of an engine valve of a prior art has the drawback that sludge from the oil pressure chamber tends to accumulate on the inner surface of the housing of the actuator, which controls the rotor in a valve timing adjusting system for controlling the valve timing of the engine. This causes troubles in the operation of the rotor. In the present invention, while the fuel delivery to the engine M1 is being cut off, the hydraulic media providing means M10 is controlled by the timing advance control means M13 to rotate further the rotor from the position at the moment that the fuel delivery is cut off, so as to clean the inner side of the housing of the actuator M9, the control of the setting and the execution of the cleaning mode is carried out by a cleaning condition judging means M14. A mode exchange means M15 controls the hydraulic media providing means M10 to exchange its normal mode and the cleaning mode, according to the state of the engine.

Hydraulic apparatus for adjusting the timing of opening and closing of

A hydraulic valve timing adjusting apparatus to be provided in a driving force transmission system for transmitting driving force to a camshaft with a cam for opening and closing an intake valve or an exhaust valve, comprising a housing assembly; a rotor provided so as to be relatively rotatable with respect to the housing assembly; hydraulic chambers formed between the rotor and the housing assembly; a convex member provided in one of the housing assembly and the rotor so as to be slidable therein; a recessed portion provided in the other one of the housing assembly and the rotor so as to be engageable with the convex member; an urging member for urging the convex member toward the recessed portion; and an oil passage which is able to supply oil pressure to the recessed portion; wherein when the oil pressure is supplied to one of the hydraulic chambers, the rotor is relatively rotated with respect to the housing assembly, and when the oil pressure is supplied to the recessed portion, the convex member is slidden in a direction opposite to the recessed portion to release engagement between the convex member and the recessed portion.

Hydraulic valve timing adjusting apparatus

A rotary hydraulic actuator including a sealed vessel including brackets and a casing, a partition vane attached to a shaft supported by the brackets for dividing an inside of the sealed vessel into a first pressure chamber and a second pressure chamber and pivoting the shaft by a pressure difference between the first and the second pressure chambers, suction and exhaust hydraulic ports and a drain port installed to the casing, a hydraulic control valve mounted to the casing for conducting a hydraulic control along with the suction and exhaust hydraulic ports and the drain port, groove-like hydraulic pressure supply paths installed to a face of one of the brackets in contact with the casing for communicating the first pressure chamber and the second pressure chamber respectively to the suction and exhaust hydraulic ports and a groove-like drain path installed to a face of other one of the brackets in contact with the casing for communicating to the drain port.

Rotary hydraulic actuator including groove-like fluid supply paths in a

In a rotary hydraulic actuator wherein a hermetic casing has the inside divided into a first hydraulic chamber and a second hydraulic chamber by a vane slidably rotatable on an inner curved wall of the casing, the vane is rotatable by an oil pressure supplied to the respective chambers, and the movement of the vane is taken out from an output shaft, the inner wall of the casing which is in sliding contact with the vane is formed with a polytetrafluoroethylene sliding member.

Growing community of inventors

Hyogo, Japan

Katsuyuki Fukuhara