Abstract: Exhaust passage control valve 10 may comprise housing 30, valve member 20, and helical torsion spring 40. Housing 30 has an exhaust passage. Exhaust gas from an internal combustion engine flows through the exhaust passage of the housing 30. Valve member 20 opens and closes the exhaust passage of the housing. Helical torsion spring 40 may be disposed at the opposite side of the valve member from the housing side thereof. Helical torsion spring 40 comprises a coil part wherein spring wires have been wound in a coil shape, and arms formed at both ends of the coil part. The coil part may be disposed at approximately the center of the valve member. When the arms bend with respect to the coil part, the counter-force of this bending energizes the valve member towards a closing side. The spring mounting member may be arranged and constructed to adjust a position in which the spring mounting member is mounted on the housing such that a rotation angle of the arms can be changed.

Abstract: To provide a fuel sealing structure capable of preventing the leakage of not only liquid fuel but also gasified fuel, an annular packing 30 is interposed between an annular sealing surface 15 on an opening part 11 of a container 20 and an annular sealing surface 25 of a closure 20. The distance between the second regions 15b, 25b of the sealing surfaces 15, 25 is shorter than that between the first regions 15a, 25a. The packing 30 includes a first sealing part 31 sandwiched between the first regions 15a,25a and a second sealing part 32 sandwiched between the 15b, 25b. The second sealing part 32 is smaller in thickness than the first sealing part 31 and the difference of the thicknesses is larger than the difference of distances between the above-mentioned regions. With the closure 20 attached, the compression ratio of the second sealing part 32 is smaller than that of the first sealing part 31.

Abstract: Exhaust passage control valve 10 may comprise housing 30, valve member 20, and helical torsion spring 40. Housing 30 has an exhaust passage. Exhaust gas from an internal combustion engine flows through the exhaust passage of the housing 30. Valve member 20 opens and closes the exhaust passage of the housing. Helical torsion spring 40 may be disposed at the opposite side of the valve member from the housing side thereof. Helical torsion spring 40 comprises a coil part wherein spring wires have been wound in a coil shape, and arms formed at both ends of the coil part. The coil part may be disposed at approximately the center of the valve member. When the arms bend with respect to the coil part, the counter-force of this bending energizes the valve member towards a closing side. The spring mounting member may be arranged and constructed to adjust a position in which the spring mounting member is mounted on the housing such that a rotation angle of the arms can be changed.

Abstract: At the time of spinning a tip reduced portion 3, an angle of inclination of the outer periphery of the tip reduced portion 3 with respect to an axis of a tube stock 2 is increased on a center side of the tube stock 2 and reduced on an end edge side thereof. By this, a generating line of an outer peripheral surface of the tip reduced portion 3 is made into a form like a center recessed curved surface.

Abstract: A revolution center line (C) of a roll (R) is made eccentric with respect to an axis (L) of an elliptic tube (1). The eccentric amount &egr; is set such that when the revolution radius of the roll (R) is gradually reduced from a state in which the roll (R) is not in contact with any part of the elliptic tube (1), the roll (R) contacts one (4) of the two protuberances (4, 4) which is located on the opposite side to the eccentric direction generally earlier than any other part of the eccentric tube (1). The roll (R) is revolved and reciprocally moved in a direction of the revolution center line (C). At least at one end portion of the reciprocal movement, the roll (R) is moved towards the revolution center line (C) side. By repeating this procedure, the roll (R) is press contacted with the first-mentioned protuberance (4) so as to crush it for elimination.