A self-hardening molding apparatus that throws self-hardening foundry sand kneaded by adding a hardener and a binder into foundry sand into a molding flask so that the molding flask is filled with the self-hardening, foundry sand to be hardened to form a mold, the self-hardening molding apparatus comprising:
- a conveyor arm that is pivotally supported around a pivot and has a conveyor for feeding the foundry sand;
- a first pivot motor that pivotally drives the conveyor arm;
- a first pulse generator that generates a pulse signal in accordance with rotation of the first pivot motor;
- a first shaft detector that includes a plurality of detection switches each being associated with a pivot angle and being configured to generate an angle detection signal indicating the pivot angle when the conveyor arm is pivoted by the pivot angle;
- a kneading arm that is pivotally attached around a pivot at a leading end of the conveyor arm to receive the foundry sand fed by the conveyor in the conveyor arm, and that feeds the foundry sand to a leading end of the kneading arm while kneading the foundry sand together with the hardener and the binder to discharge the kneaded self-hardening foundry sand from a discharge port provided at the leading end of the kneading arm;
- a second pivot motor that pivotally drives the kneading arm with respect to the conveyor arm;
- a second pulse generator that generates a pulse signal in accordance with rotation of the second pivot motor;
- a second shaft detector that includes a plurality of detection switches each being associated with a pivot angle and being configured to generate an angle detection signal indicating the pivot angle when the kneading arm is pivoted by the pivot angle;
- a processor configured to:
- perform teaching storage operation of storing teaching data created on the basis of signals from the first pulse generator, the first shaft detector, the second pulse generator, and the second shaft detector when teaching operation of throwing the kneaded self-hardening foundry sand from the discharge port into the molding flask is performed by moving the conveyor arm and the kneading arm manually, the teaching data being stored in a storage unit as a sequence control program of molding operation of a self-hardening mold;
- and
- perform molding playback operation to perform the molding operation of a self-hardening mold by reading, out the sequence control program from the storage unit to control and drive the first pivot motor and the second pivot motor on the basis of the sequence control program,
- wherein the processor calculates a rotation angle of the conveyor arm or the kneading arm by counting the pulse signal outputted from the first pulse generator or the second pulse generator from a starting point at which the angle detection signal to be outputted from each of the first shaft detector and the second shaft detector is generated, thereby performing the teaching storage operation or the molding playback operation.