Aisin Seiki Kabushiki Kaisha

Eiji Shirai

Yoshio Okabe

Yukimori Kobayashi

Hisashi Kodama

Masaharu Hayashi

Yoshiyuki Kawai

Koji Hotta

Shigeru Katsuragi

Shinji Otsuka

A valve gear device includes a stem having one end and the other end, an intake and exhaust valve connected to the other end of the stem and serving for opening and closing a port formed in a cylinder block of an internal combustion engine, a first spring biasing the stem toward a closing condition of the intake and exhaust valve, a cam, and a valve control device interposed between the cam and one end of the stem, the valve control device having a first member fitted in the cylinder block so as to be slidable along an axis of the stem and engaged with the cam, a second member receiving one end of the stem and movable within the first member relative thereto and a regulating device for permitting and preventing the movement of the second member relative to the first member. Such a structure enables that the top end of the stem is out of sliding engagement with any of related members, thereby preventing a friction wear of the top end of the stem.

Valve gear device

In a valve control device for an engine having a fuel supply means arranged in a suction passage, a valve arranged in an intake or exhaust passage, and a cam for driving the valve to open and close via a lifter, the lifter comprises a body which slides in a bore of a cylinder head of the engine, a cylinder arranged in the body and forming a sliding passage perpendicularly to an axial direction of the valve, a spool which is transferred between a first position and a second position in the sliding passage by hydraulic pressure, a slider arranged in the spool and having a driving force transmitting portion and a cavity portion, and a spring which holds the spool at the first position, and a stop valve is arranged between the fuel supply means and the valve in the suction passage in order to close the suction passage when the spool is at the first position. When the spool is held at the second position, the driving force of the cam is transmitted to the valve only via the body and the driving force transmitting portion of the slider, and never transmitted to the spool. Thus, a stabilized change-over operation of the valve control device is achieved.

Valve control device for an engine

A valve gear device for internal combustion engines comprises a suction and exhaust valve which is driven to be opened or closed by a high-speed cam or low-speed cams through a lifter wherein a guide plate is formed on the cam shaft and a guide groove which constantly engages with the guide plate is formed on the top portion of the body of the lifter. Also, the high-speed cam itself may function as the guide plate. The contacting surface of the high speed cam and the low speed cams can be surely regulated by the guide groove which constantly engages with the guide plate. Accordingly, the present invention can provide a small-sized valve gear device which surely regulates the contacting surface of the high-speed cam and the low-speed cams with the lifter.

Valve gear device for internal combustion engines

A tensioner for vehicle belts produces reduced rattling because radial forces are not transferred to the plunger. A tensioner body has a columnar hole extending from an open end toward a closed end. The plunger is fitted into the columnar hole and separates the columnar hole into first and second chambers. The plunger has sufficient clearance with respect to the body to permit restricted passage of fluid between the chambers. A rod pressed by the belt extends into the columnar hole and presses the plunger against the biasing force of a spring. In order to reduce the transfer of radial forces from the rod to the plunger, either the lower surface of the rod or the upper surface of the plunger is formed in a semi-spherical shape.

Tensioner with reduced rattling

For preventing very small amplitude vibrations of the rod in a tensioner during high speed movement of a belt to be tensioned by the tensioner, a tube which is connected to a plunger which moves together with the rod is overlapped with a stationary member so as to define an annular clearance therebetween in an operating chamber of the tensioner. By filling an operating fluid in the clearance, shear strain is generated upon high speed movement of the plunger, which resists movement of the plunger.

Tensioner

For adjusting an angular phase difference between an engine crank shaft and an engine cam shaft, fluid under pressure is supplied into one or more chambers defined therebetween. The adjusted condition is maintained or held by mechanical engagement between both shafts.

Device for adjusting an angular phase difference between two elements

A free piston type auto-tensioner adjusts a tension of an engine timing belt for automobiles. The auto-tensioner includes a body, a plunger slidably disposed in the body to form a first oil chamber, a free piston slidably disposed in the body to form a second oil chamber, a first seal member disposed between the body and the piston, a second seal member disposed between the piston and a rod of the plunger, an oil passage formed in the plunger to establish an oil communication between the first and second oil chambers, a check valve disposed in the oil passage, a first spring biasing the plunger, and a second spring biasing the piston.

Free piston type auto-tensioner

A self-container hydraulic valve lifter includes a lifter body slidably mounted in a lifter case, a free piston slidably mounted between the lifter body and the lifter case, a plunger slidably mounted in the lifter body and dividing an interior portion of the lifter body into a reservoir chamber and a pressure chamber, a check valve for allowing fluid flow from the reservoir chamber to the pressure chamber, and an operating chamber formed between the free piston and the lifter case and communicated with the reservoir chamber in order to decrease the diameter of the pressure chamber in comparison with that of the free piston.

Growing community of inventors

Okazaki, Japan

Eiji Shirai