Abstract: A joined body includes: a thin plate including through holes; a first member including a proximal portion having a portion contacting the thin plate, and a protruding portion that protrudes in relation to a contact surface of the proximal portion and is inserted through the through hole; and a second member arranged oppositely to the proximal portion via the thin plate and made of a material that is same as that of the first member. The thin plate is made of a material having a specific gravity smaller than that of the material forming the first and the second members. The second member and an end portion of the protruding portion are connected to each other, by a part of the second member and a part of the end portion being melt-solidified, the end portion being at a side opposite to a side connected to the proximal portion.

Abstract: A joined body includes: a thin plate including through holes; first members each including: a base portion and a protruding portion inserted into one of the through holes; and a second member placed oppositely to the base portion via the thin plate and made of a material that is of a same kind as a material of the first members. The thin plate is made of a material having a specific gravity smaller than the materials of the first and the second members. The second member and an end portion of the protruding portion are connected together by melt-solidification. A post-joining hardness difference in a range of 30% along a direction orthogonal to a joint interface between the second member and the protruding portion, the range being centered on the joint interface, is equal to or less than 90% of a pre-joining hardness difference.

Abstract: A joined body includes: a thin plate including through holes; first members each including: a base portion and a protruding portion inserted into one of the through holes; and a second member placed oppositely to the base portion via the thin plate and made of a material that is of a same kind as a material of the first members. The thin plate is made of a material having a specific gravity smaller than the materials of the first and the second members. The second member and an end portion of the protruding portion are connected together by melt-solidification. A post-joining hardness difference in a range of 30% along a direction orthogonal to a joint interface between the second member and the protruding portion, the range being centered on the joint interface, is equal to or less than 90% of a pre-joining hardness difference.

Abstract: A joined body includes: a thin plate including through holes; a first member including a proximal portion having a portion contacting the thin plate, and a protruding portion that protrudes in relation to a contact surface of the proximal portion and is inserted through the through hole; and a second member arranged oppositely to the proximal portion via the thin plate and made of a material that is same as that of the first member. The thin plate is made of a material having a specific gravity smaller than that of the material forming the first and the second members. The second member and an end portion of the protruding portion are connected to each other, by a part of the second member and a part of the end portion being melt-solidified, the end portion being at a side opposite to a side connected to the proximal portion.

Abstract: A vibration damping device comprises: a spindle member through which a shaft portion is inserted, the spindle member being movable along a length direction of the shaft portion; a first coil spring disposed between the spindle member and one end portion of the shaft portion in the length direction, the one end portion of the shaft portion being inserted through the first coil spring, and the first coil spring urging the spindle member toward a side of another end portion of the shaft portion in the length direction; and a second coil spring disposed between the another end portion of the shaft portion and the spindle member, the another end portion of the shaft portion being inserted through the second coil spring, and the second coil spring urging the spindle member toward a side of the one end portion of the shaft portion.

Abstract: A vibration damping device comprises: a spindle member through which a shaft portion is inserted, the spindle member being movable along a length direction of the shaft portion; a first coil spring disposed between the spindle member and one end portion of the shaft portion in the length direction, the one end portion of the shaft portion being inserted through the first coil spring, and the first coil spring urging the spindle member toward a side of another end portion of the shaft portion in the length direction; and a second coil spring disposed between the another end portion of the shaft portion and the spindle member, the another end portion of the shaft portion being inserted through the second coil spring, and the second coil spring urging the spindle member toward a side of the one end portion of the shaft portion.