Honda Motor Co., Ltd.

Honda Giken Kogyo Kabushiki Kaisha

Hideaki Aoyama

Toru Yagasaki

Shigeru Kanehara

Takamichi Shimada

Hideaki Yoshida

Yuichiro Takemori

Yoshiharu Watabe

Hirofumi Akagi

Ukyo Ogata

Seiichi Minegishi

Tooru Yagasaki

Ryo Katayama

Manabu Murakami

Ryohta Aoki

A control device includes: a clamping force determination unit that determines a clamping force Fs so that a transmission gear ratio R of a stepless transmission is a target transmission gear ratio; a correction unit that corrects the clamping force Fs determined by the clamping force determination unit, based on an oil temperature TO of a lubricant interposed between each of pulleys and a belt and the transmission gear ratio R; and a clamping force control unit that controls clamping of the pulleys and to be performed with the clamping force Fs corrected by the correction unit.

Control device for stepless transmission

A continuously variable transmission metal belt includes a metal ring assembly and metal elements. The metal ring assembly includes stacked endless metal rings. Each of the stacked endless metal rings includes a flat peripheral surface and a substantially semicircular end face. The substantially semicircular end face is connected to an end of the peripheral surface in a width direction of each of the stacked endless metal rings. The metal elements are supported on the metal ring assembly. A displacement Z of the end face is smaller than or equal to 0.1R. The displacement Z is defined as Z=R&#x2212;H. R is a radius of an imaginary circle that passes through a contact point between the peripheral surface and the end face and that is tangent to the end face. H is a distance from a center of the imaginary circle to the peripheral surface.

Method for manufacturing metal ring of continuously variable transmission metal belt

Although a radial outside portion of a metal ring contact surface of a neck section of a metal element which is contactably opposed to a side edge of a metal ring of a metal ring assembly has high frequencies of contacting with a side edge of the metal ring, it is possible to suppress abrasion of the side edge of the metal ring and to improve durability of the metal ring by setting a surface hardness of the radial outside portion lower than a surface hardness of the metal ring. In addition, by setting a surface hardness of the metal ring contact surface at its portion of the radial outside lower than the surface hardness of the metal ring contact surface at other portions thereof where the frequencies of contacting with the side edge of the metal ring becomes low, in comparison with a case of setting the surface hardness of the whole metal ring contact surface low, it is possible to increase strength of the metal element and to improve the durability of the metal element.

Metal belt for continuously variable transmission

A metal V-belt includes a plurality of metal elements supported by a metal ring. The metal ring includes front and rear main surfaces, a pair of left and right slots that receive the metal ring therein, the slots being defined between a saddle surface and an ear-part bottom surface. A protrusion is provided on one of the front and rear main surfaces, and a concavity is provided in the other of the front and rear main surfaces. A clearance defined between an outermost peripheral surface of the metal ring and the ear-part bottom surface of the metal element is set to a value that at an exit of a driven pulley, contact of the innermost peripheral surface of the metal ring with the saddle surface of the metal element, and contact of the protrusion of a succeeding metal element and the concavity of a preceding metal element is avoided.

Metal V-belt

In a continuously variable transmission metal belt, a lateral-most projecting portion of a side edge of a metal ring assembly wherein each metal ring is located between a radially central plane and a radially inner peripheral surface of the metal ring. A contact point in which the projecting portion abuts against a V-face of a pulley is closer to the radially central plane than to the radially inner peripheral surface. Moreover, as the metal rings are laminated on one another, recesses are formed between the side edges of the adjacent metal rings to retain oil therein, which lubricates the sliding faces of adjacent metal rings and enhances durability of the assembly.

Continuously variable transmission metal belt, process for producing metal ring, and process for measuring shape of metal ring

A metal belt includes a metal ring assembly formed from a plurality of layered endless metal rings, and a large number of metal elements supported on the metal ring assembly, the metal belt assembly being wound around a pulley and transmitting a driving force. The clearance between adjacent metal rings is set to be in a range from negative to positive from the innermost ring to a middle ring and to be only positive from the middle ring to the outermost ring. Therefore, good lubricating conditions can be maintained by virtue of the clearance being always positive for sliding surfaces of the metal rings from the middle ring to the outermost ring, for which lubrication easily becomes insufficient in the prior art. Thus the behavior is stabilized, preventing a side face of the metal ring from coming into dynamic contact with a metal ring contact face of a neck portion of the metal element, and maintaining the tension of the metal ring in the innermost ring at a low level, so that friction is suppressed to extend the life of the ring.

Metal belt

A circumferential length correcting method for a metal ring including: a circumferential length measuring step of passing the metal ring around a driving roller and a driven roller, displacing the driving roller and the driven roller away from each other, and measuring the actual circumferential length of the ring under tension; and a circumferential length correcting step of correcting the circumferential length of the ring by displacing a circumferential length correcting roller by a predetermined distance in a direction in which the metal ring is extended. The method is capable of imparting an appropriate arc shape to the metal ring while correcting the circumferential length to fall within an appropriate value range. Before the circumferential length correcting step, the method includes an arc-shape imparting step of displacing an arc-shape imparting roller, which has an arc-shaped circumference and is positioned inside a metal ring, by a predetermined distance in a direction in which the metal ring is extended, thereby imparting an arc shape conforming to the shape of the circumference of the arc-shape imparting roller to the metal ring.

Circumferential length correcting method and apparatus for metal ring

In a metal belt for a continuously variable transmission, when a laterally inner end of a metal ring assembly abuts a neck, a laterally outer end of the metal ring assembly is positioned at a location displaced toward the neck from a laterally outer end of an ear. When the metal belt is transported as an independent item or even when assembled to the continuously variable transmission, contact with another article with the laterally outer end of the metal ring assembly is prohibited by a laterally outer end of the ear to prevent damage to the metal ring assembly and the metal ring assembly from falling off of the ring slot. In addition, the entire widthwise region of the metal ring assembly is opposite to the lower ear face, so that a sufficient amount of oil is retained on the opposite surface, to enhance a metal element-cooling effect.

Belt for continuously variable transmission

A belt for a continuously variable transmission including a plurality of metal ring assemblies and a plurality of metal elements is provided, wherein a main surface of each of the plurality of metal elements is formed at its three portions with contact faces for transmitting a pushing force in the fore-and-aft direction, and the radial position of the centroid of the contact faces is set between a center line in a thickness direction of the metal ring assembly fitted into the ring slot of the metal element and a line along a radial outer edge of the ring slot. With this structure, a compressed-side chord of the metal belt can assume a straight shape or a slightly outwardly warped shape, and it is possible to elongate the life of the metal ring assemblies to reduce noise and vibration, and to enhance the power transmitting efficiency.

A metal belt includes a pair of metal rings and a plurality of metal elements supported along the metal rings. Each metal ring includes a plurality of endless metal bands that are stacked on each other. Each metal element includes a nose portion and a corresponding hole and is constructed to satisfy a relationship that L /L >0.8 such that L is a lateral distance between the center of the nose portion and a contact point P defined when the metal element pivots about its nose portion to form point contact between one of the pair of lobes and a corresponding one of the pair of metal rings and L is a lateral distance between the center of the nose portion and a contact point P defined when the metal element pivots about its nose portion to form point contact between the other metal ring and the body portion.

A metal V-belt comprising an endless metal ring member and a plurality of metal element members supported along said metal ring member wherein the clearance between a slot portion S of the metal element members and the endless metal ring member is set larger than the clearance in the thickness direction of the belt between the concave and convex portions of a coupling portion used for linking disposed on the front and rear surfaces of the metal element members . This controls damage to the metal ring member caused by contact between the metal ring member outermost periphery of the metal V-belt used in, for example, an infinite variable-speed drive and the metal element members.

In a metal V-belt type continuously variable transmission having a driving pulley and a driven pulley, the inclination angle .alpha. of a V-groove in the pulleys is set in a range represented by tan.sup.-1 .mu.a&lt;.alpha.&lt;tan.sup.-1 .mu.s, wherein .mu.s represents the static friction coefficient between the pulley and an endless belt, and .mu.a represents the dynamic friction coefficient between the pulley and the endless belt. In a conventional metal V-belt type continuously variable transmission, the inclination angle .alpha. is set in a range represented by .alpha.&gt;tan.sup.-1 .mu.s. If the transmittable torque Tin is increased, the tensile force of the endless belt is increased to produce slipping between the endless belt and the pulley. However, according to the present invention, by decreasing the inclination angle .alpha. to reduce the tensile force of the endless belt, the transmittable torque Tin can be increased while preventing slipping of the endless belt.

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Wako, Japan

Hideaki Aoyama