초록 ▼

A belt (3) of a continuously variable transmission comprises a pair of endless rings (2a) and plural elements (1) held between the pair of endless rings (2a). The endless rings (2) are formed of plural laminated thin plates (2a). A prestress in a compression direction is applied beforehand to the su

A belt (3) of a continuously variable transmission comprises a pair of endless rings (2a) and plural elements (1) held between the pair of endless rings (2a). The endless rings (2) are formed of plural laminated thin plates (2a). A prestress in a compression direction is applied beforehand to the surfaces of the thin plates (2a) by a nitriding treatment. In this process, a defect part (2b) is formed as a hollow in the thin plate (2a) due to scatter in the nitriding treatment. This invention measures the depth of the defect part (2b), and if the measured depth exceeds a predetermined tolerance value, it is determined that the prestress is insufficient. Due to this determination method, a highly precise inspection of the thin plates (2a) forming the endless rings (2) can be performed in a short time.

대표청구항 ▼

What is claimed is: 1. A method for inspecting a belt of a continuously variable transmission, the belt comprising an endless ring comprising a thin plate which has undergone a prestress in a compression direction by nitriding treatment, the nitriding treatment, when applied insufficiently, forming

What is claimed is: 1. A method for inspecting a belt of a continuously variable transmission, the belt comprising an endless ring comprising a thin plate which has undergone a prestress in a compression direction by nitriding treatment, the nitriding treatment, when applied insufficiently, forming a hollow in a surface of the thin plate, the method comprising: measuring a depth of the hollow in the surface of the thin plate, wherein the hollow has a bottom and the depth of the hollow represents a level difference between a reference surface which has undergone a sufficient prestress and the bottom of the hollow; determining a target value of the prestress; determining a permitted minimum value which has a fixed relation to the target value of the prestress; calculating a prestress difference between the target value of the prestress and the permitted minimum value; converting the prestress difference into a predetermined tolerance value; comparing the measured depth of the hollow with the predetermined tolerance value; and determining that the nitriding treatment is insufficient when the measured depth exceeds the predetermined tolerance value. 2. The inspection method as defined in claim 1, wherein the belt further comprises another endless ring to form a pair of endless rings, plural elements which are held between the pair of the endless rings, and a pair of pulleys around which the belt is looped in a state where two sides of the plural elements contact the pulleys, each of the pair of the endless rings is formed of plural laminated thin plates which undergo a tensile stress and a bending moment when the belt transmits a torque between the pair of pulleys.