Patent ID: 7726380

Claim:
A method of producing a sand mold, comprising: after defining a mold space by at least a pattern plate, a flask, and a squeeze means, and after blow-charging molding sand held in a sand blowing device located above the mold space into the mold space by ejecting a first compressed air near sand ejecting ports of the sand blowing device thereby fluidizing the molding sand near the sand ejecting ports, while supplying a second compressed air to a surface of the molding sand held in the sand blowing device, moving the squeeze means toward the pattern plate, wherein the distance of the movement of the squeeze means toward the pattern plate is measured when the squeeze of the molding sand in the mold space is completed, the difference between the measured distance and a target distance is calculated, and based on the result of the calculation the period of time for ejecting the first compressed air is made shorter or lengthened to change a condition for blow-charging the molding sand in the mold space.