Overhead transport vehicle
An overhead transport vehicle includes a vibration-proof portion disposed between a belt and a lift device. The vibration-proof portion includes a first connection mechanism disposed on a side where a first load acts in a width direction perpendicular or substantially perpendicular to both a travelling direction and a lifting direction of the lift device, and a second connection mechanism disposed on a side where a second load larger than the first load acts in the width direction, and which has a larger repulsive force than that of the first connection mechanism.
1. An overhead transport vehicle comprising:
a body capable of travelling along a track; and
a grip liftably provided in the body by a plurality of suspensions and capable of gripping an article; wherein
the overhead transport vehicle includes a vibration-proof portion disposed between the plurality of suspensions and the grip;
the vibration-proof portion includes:
a first vibration-proof portion disposed on a side, where a first load acts, in a travelling direction of the body or in a width direction perpendicular or substantially perpendicular to both the travelling direction and a lifting direction of the grip; and
a second vibration-proof portion disposed on a side, where a second load larger than the first load acts, in the travelling direction or in the width direction and having a larger repulsive force than a repulsive force of the first vibration-proof portion; and
the first vibration-proof portion and the second vibration-proof portion each includes a spring or a plurality of springs.
2. The overhead transport vehicle according to claim 1 , wherein the article is a container to house an object to be housed, or the container housing the object to be housed;
a spring constant of the spring or the plurality of springs in the first vibration-proof portion is equal or substantially equal to a spring constant of the spring or the plurality of springs in the second vibration-proof portion; and
the spring or the plurality of springs in the first vibration-proof portion and the spring or the plurality of springs in the second vibration-proof portion are pressurized so as to eliminate a tilt of the grip which occurs at a time of lifting the container due to presence of a deviation between a center of gravity of the grip and a center of gravity of the container that is in an empty state and gripped by the grip.
3. The overhead transport vehicle according to claim 1 , wherein
the grip is suspended from the body by four of the suspensions; and
two of the four suspensions are connected to one swing that is swingably fixed to the grip.