Aisin Seiki Kabushiki Kaisha

Toyota Jidosha Kabushiki Kaisha

Yoshio Okabe

Hisashi Kodama

Yukimori Kobayashi

Eiji Shirai

Fuminao Arai

Masaharu Hayashi

Makoto Ishikawa

Takanobu Hori

Tomiaki Atsumi

Tamotsu Kamiya

Fumio Arai

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

A hermetically sealed autotensioner used for adjusting tension of engine belts comprises a cylinder, a plunger slidably fitted in the cylinder and having a rod projeced from the cylinder, a free piston slidably fitted in the cylinder, and a rod guide fitted in the tip portion of the cylinder so as to slidably support the rod. When a large thrust force acts on the rod, the rod guide serves as a bearing for the rod so that no scuffing or rocking motion occurs between the cylinder and the plunger.

Hermetically sealed autotensioner

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 self-contained hydraulic lash adjuster in which a bag member is disposed in a reservoir chamber formed within a plunger. An open upper end portion of the bag member is fixedly mounted with a metal ring therein so as to be fixed to an upper end portion of the reservoir chamber in spite of successive deformation of the bag member in accordance with oil-volume variation in the reservoir chamber.

Self-contained hydraulic lash adjuster

A self-contained type automatic belt tensioner adjusts a tension of an engine timing belt for automobiles. The tensioner comprises a body, a plunger slidably mounted in the body, a reservoir chamber located in the plunger, a pressure chamber disposed between the plunger and a closed wall of the body, a rod member fixed to the plunger, a bellows shaped elastic diaphragm located in the reservoir chamber with one end thereof being fixed to the rod member and the other end being fixed to the body, a check valve allowing a fluid flow only from the reservoir chamber to the pressure chamber, and a return spring interposed between the plunger and the closed wall of the body so as to bias said plunger in the direction of the rod member.

Self-contained type automatic belt tensioner

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 cylinder control device for a variable-cylindered engine. The device comprises a body slidable within a bore formed in a block and urged by a spring always in contact with a cam, a plunger mounted in the body and slidable by hydraulic pressure in the direction perpendicular to the direction of sliding of the body, the plunger having a groove which is adapted to be engaged by the upper end of a valve stem 40 and an escape bore which is adapted to be positioned right above the upper end of the valve stem when the plunger is slided to a cylinder-inoperative position; and means for controlling said application of the hydraulic pressure to the plunger under the control of a computer. When the computer provides an instruction for normal operation of the cylinder, the plunger is held at a position where the upper end of the valve stem engages with the groove in the plunger so that, when the cam is rotated, the valve stem is depressed through the body thereby to open the valve port, whereas, when the hydraulic pressure is applied to the plunger so as to urge the plunger to a valve-inoperative position, the upper end of the valve stem escapes into the escape bore in the plunger when the body is depressed by the cam, so that the valve stem is not depressed and the valve is kept closed, thereby keeping the cylinder inoperative.

Cylinder control device for variable-cylindered engine

An auto-tentioner of timing-belt used for apparatus such as automobiles, which comprises a body, a plunger inserted into the body, a piston inserted in the pluner and protruding from the body so as to push the timing-belt, and a spring at the rear end of the body and pushing the body to the direction of timing-belt, thereby making it possible for the auto-tentioner fully to follow up the extraordinary expansion of the timing-belt.

Auto-tensioner for timing-belt

An auto-tensioner for belt systems and a method for adjusting the belt tension, said auto-tensioner comprising an idler pulley, a tensioner body, a bracket fixed to the tensioner body and swingable around a first fixing bolt, a second fixing bolt inserted in a slit of the bracket so as to adjust the swing degree of the bracket, and a third bolt for positioning the idler pulley; while said adjusting method comprising the steps of making the first and second fixing bolts to be half-tightened state, tightening the third bolt to position the idler pulley, adjusting the spring force for biasing the bracket, fully tightening the first and second fixing bolts, and finally removing the third positioning bolt, thereby to avoid the troublesomeness in the adjusting works of belt tension.

Auto-tensioner for belt systems and a method for adjusting tension degree

An automatic tensioner for adjusting the tension in a timing belt, V belt, or the like has a locking mechanism. The tensioner has a plunger always biased toward a large oil chamber containing oil. A rod having a head that is pressed against the timing belt or the like is inserted in the body of the tensioner so as to form a small oil chamber. A piston is received in the body of the tensioner. Normally, the piston bears against the plunger. If oil should leak from the large oil chamber, then the plunger will move downward, permitting the piston to engage the rod. Thus, the rod is locked.

Automatic tensioner having locking mechanism

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.

Self-contained hydraulic valve lifter

A self-contained tensioning device for a belt or similar structure and which includes a plunger slidably mounted in a body member, a free piston slidably mounted in the plunger and having a head portion extending from a shoulder of the body member and which contacts with an idler pulley so as to apply a tensioning face to the belt, a projection provided on the shoulder and projecting axially so as to minimize the distance between a portion of the idler pulley contacting the head portion and the shoulder of the body member.

Self-contained tensioning device for a belt or similar structure

A hydraulic autotensioner of a sealed type is used to give tension to a belt or a chain. The hydraulic autotensioner includes a body member having a large diameter oil chamber, a plunger having a small diameter oil chamber and a small passage, a piston whose head extends outside the body member and a spring for biasing the plunger.

Tensioning device for belt or the like

A sealed-type automatic tensioner has a body assembly composed of upper and lower tubular bodies held in threaded engagement with each other, a tubular plunger slidably disposed in the body assembly, a piston slidably disposed in the tubular plunger and having a portion extending slidably through a hole in a top wall of the upper tubular body. The lower tubular body and the tubular plunger jointly define a larger-diameter hydraulic chamber, and the tubular plunger and the piston jointly define a smaller-diameter hydraulic chamber. A bottom wall of the tubular plunger has an aperture through which the larger- and smaller-diameter chambers communicate with each other. A compression coil spring is disposed in the first tubular body and acts between the top wall of the upper tubular body and the tubular plunger for normally urging the tubular plunger to move into the larger-diameter chamber.

Growing community of inventors

Chiryu, Japan

Yoshio Okabe