Binder supply apparatus and binder supply method for foundry sand

Abstract

Disclosed is a binder supply apparatus for supplying a liquid binder to foundry sand. The binder supply apparatus comprises: a reservoir tank for reserving the binder therein; a first pump for supplying the binder to the reservoir tank; a temperature adjusting device for adjusting the temperature of the binder in the reservoir tank to a given temperature; a second pump for circulating the binder such that the binder is discharged from the reservoir tank to a circulation passage and then re-suppled to the reservoir tank; a flowmeter for measuring the flow rate of the binder flowing through the circulation passage; and a binder ejection port for ejecting the binder.

1 . A binder supply apparatus for supplying a liquid binder to foundry sand, comprising:
 a reservoir tank for reserving the binder therein;   a first pump for supplying the binder to the reservoir tank;   a temperature adjusting device to adjust a temperature of the binder in reservoir tank to a given temperature;   a second pump for circulating the binder such that the binder is discharged from the reservoir tank to a circulation passage and then re-suppled to the reservoir tank;   a flowmeter for measuring a flow rate of the binder flowing through the circulation passage; and   a binder ejection port for ejecting the binder to allow the binder to be kneaded with the foundry sand.   
     
     
         2 . The binder supply apparatus according to  claim 1 , wherein the flowmeter is installed in the circulation passage at a position downstream of the second pump, and wherein the binder supply apparatus further comprises a three-way valve installed in the circulation passage at a position downstream of the flowmeter, and configured to switch a flow direction of the binder supplied from the second pump, between toward a first side allowing the binder to be supplied to the reservoir tank and toward a second side allowing the binder to be supplied to the binder ejection port. 
     
     
         3 . The binder supply apparatus according to  claim 1 , wherein the binder supply apparatus further comprises a bypass passage for removing air entrained in the binder, the bypass passage being communicably connected to the circulation passage at a position downstream of the second pump, and the reservoir tank, while bypassing the flowmeter. 
     
     
         4 . The binder supply apparatus according to  claim 1 , wherein the binder supply apparatus further comprises an opening-closing valve installed adjacent to and upstream of the binder eject port. 
     
     
         5 . The binder supply apparatus according to  claim 1 , wherein the foundry sand is core sand for making a core. 
     
     
         6 . The binder supply apparatus according to  claim 5 , wherein the core sand is core sand for making an inorganic core. 
     
     
         7 . A binder supply method for supplying a liquid binder to foundry sand, comprising the steps of:
 supplying, by a first pump, the binder to a reservoir tank;   circulating, by a second pump, the binder such that the binder is discharged from the reservoir tank to a circulation passage and then re-suppled to the reservoir tank;   adjusting, by a temperature adjusting device, a temperature of the binder in the reservoir tank to a given temperature; and   measuring, by a flowmeter, a flow rate of the binder flowing through the circulation passage.   
     
     
         8 . The binder supply method as recited in  claim 7 , wherein the binder supply method further comprises a step of switching, by a three-way valve installed in the circulation passage at a position downstream of the second pump via the flowmeter, a flow direction of the binder supplied from the second pump, between toward a first side allowing the binder to be supplied to the reservoir tank and toward a second side allowing the binder to be supplied to a binder ejection port. 
     
     
         9 . The binder supply method according to  claim 8 , wherein, during a time period during which the binder supplied from the second pump is ejected from the binder ejection port, the flow rate of the binder being supplied from the second pump is measured by the flowmeter to figure out an amount of the binder to be ejected from the binder ejection port, and, in response to ascertaining that the amount of the binder to be ejected reaches a setup amount set to a value less than a target ejection amount, the second pump is changed to be operated on a pulse-by-pulse basis. 
     
     
         10 . The binder supply method according to  claim 8 , wherein, during any time period except for a time period during which the binder supplied from the second pump is ejected from the binder ejection port, the binder supplied from the second pump is circulatingly supplied to the reservoir tank. 
     
     
         11 . The binder supply method according to  claim 7 , wherein the second pump is operated on a pulse-by-pulse basis, and wherein a pulse period is adjusted to reduce a flow rate per pulse of the binder to be supplied from the second pump.