Transport carriage

1 . A transport carriage for transporting workpieces by traveling on a transport passageway installed over a processing apparatus, the transport carriage comprising:

a main body frame;

a receptacle for housing workpieces, wherein said receptacle includes a first workpiece unit and a second workpiece unit, said first workpiece unit having a first size and said second workpiece unit has a second size, wherein said first size and said second size are different;

a storage area on the main body frame configured for storing the receptacle;

a lifting and lowering unit attached to the main body frame configured for lifting and lowering the receptacle between the storage area and the processing apparatus; and

a determining unit for determining whether the workpiece is housed in the receptacle or not.

2 . The transport carriage according to claim 1 , wherein the determining unit includes a non-contact-type sensor for detecting the workpiece through the receptacle.

3 . The transport carriage according to claim 1 , wherein

the lifting and lowering unit includes a suspending member connected to the receptacle for suspending the receptacle, a rotatable reel with the suspending member wound therearound, and an electric motor for controlling rotation of the reel, and

the determining unit for determining whether the workpiece is housed in the receptacle or not on a basis of torque of the electric motor.

4 . The transport carriage according to claim 1 , wherein

an individual identification tag representing individual information of the workpiece is attached to the workpiece, and

the determining unit reads the individual information from the individual identification tag.

5 . The transport carriage according to claim 1 , wherein the main body frame includes first sensors mounted on front and rear ends of the main body frame and second sensors mounted on left and right sides of the main body frame, wherein the first sensors and the second sensors each face the transport passageway and are configured to detect marks on the transport passageway to control the movement of the main body frame on the transport passageway.

6 . The transport carriage according to claim 1 , wherein the main body frame includes third sensors mounted on a front end of the main body frame, the third sensors are configured for detecting an obstacle on the transport passageway.