Mixing and water adjusting method for foundry sand

Patent metadata

Field	Value
Publication number	US-10144054-B2
Application number	US-201314391036-A
Country	US
Kind code	B2
Filing date	Jun 4, 2013
Priority date	Jun 13, 2012
Publication date	Dec 4, 2018
Grant date	Dec 4, 2018

Abstract

A mixing and adjusting method for foundry sand includes calculating a total supplied water amount until a compactability (CB) value of mixed sand becomes larger than a lower limit value of a target CB value range, determining the total supplied water amount as a predetermined amount of water associated with an electric resistance of the foundry sand, and determining a ratio of a variation in the CB value corresponding to an additionally supplied water amount from the additionally supplied water amount during an additional water pouring and the CB value of the mixed sand.

First claim

The invention claimed is:

1. A mixing and adjusting method for foundry sand that uses a sand muller for the foundry sand, the method comprising:
measuring a weight of the foundry sand before the foundry sand is charged into the sand muller;
measuring an electric resistance of the foundry sand before the foundry sand is charged into the sand muller;
charging the foundry sand into the sand muller;
calculating an estimated supplied water amount based, at least in part, on a predetermined amount of water associated with the electric resistance of the foundry sand, and pouring primary water in an amount less than the estimated supplied water amount into the foundry sand charged into the sand muller;
mixing the foundry sand with the primary water to obtain first mixed sand;
measuring a first compactability (CB) value of the first mixed sand;
when the first CB value is equal to or less than a lower limit value of a target CB value range, pouring additional water into the first mixed sand, wherein an amount of the additional water is less than a difference between the estimated supplied water amount and an amount of water supplied before measuring the first CB value;
mixing the first mixed sand with the additional water to obtain second mixed sand; and
measuring a second CB value of the second mixed sand, wherein
pouring the additional water, mixing the first mixed sand with the additional water, and measuring the second CB value are repeated until the second CB value becomes larger than the lower limit value;
a total supplied water amount until the second CB value becomes larger than the lower limit value is calculated, and the total supplied water amount is determined as the predetermined amount of water; and
a ratio of a variation in the CB value corresponding to the additionally supplied water amount is determined from the additionally supplied water amount during the additional water pouring and the second CB value.

2. The mixing and adjusting method for foundry sand according to claim 1 , wherein
an amount of water supplied in one cycle decreases as a number of water pouring cycles increases after the additional water pouring has been performed after the primary water pouring.

3. The mixing and adjusting method for foundry sand according to claim 2 , wherein
when water is supplied into the foundry sand, a leak water amount is corrected for each end of water pouring operation by a difference between a target amount of water that is to be supplied through a digital flow meter communicated with a water source and an accumulated flow rate measured by the digital flow meter, and
the leak water amount is caused by operation delay occurring when an electromagnetic valve communicated with the digital flow meter is closed.

4. The mixing and adjusting method for foundry sand according to claim 1 , wherein
when water is supplied into the foundry sand, a leak water amount is corrected for each end of water pouring operation by a difference between a target amount of water that is to be supplied through a digital flow meter communicated with a water source and an accumulated flow rate measured by the digital flow meter, and
the leak water amount is caused by operation delay occurring when an electromagnetic valve communicated with the digital flow meter is closed.

5. A mixing and adjusting method for foundry sand that uses a sand muller for the foundry sand, the method comprising:
measuring a weight of the foundry sand before the foundry sand is charged into the sand muller;
measuring an electric resistance of the foundry sand before the foundry sand is charged into the sand muller;
charging the foundry sand into the sand muller;
determining a primary supplied water amount based, at least in part, on a first relationship between a predetermined amount of water and the electric resistance of the foundry sand, and pouring primary water in the primary supplied water amount into the foundry sand charged into the sand muller;
mixing the foundry sand with the primary water to obtain first mixed sand;
measuring a compactability (CB) value of the first mixed sand;
when the CB value is equal to or less than a lower limit value of a target CB value range, calculating a difference between the CB value and a target CB value as a CB difference;
determining an additionally supplied water amount corresponding to the CB difference based, at least in part, on a second relationship between a ratio of a variation in the CB value and the additionally supplied water amount, and pouring additional water in the additionally supplied water amount into the first mixed sand; and
mixing the first mixed sand with the additional water to obtain second mixed sand.

6. The mixing and adjusting method for foundry sand according to claim 5 , wherein
the primary supplied water amount and the additionally supplied water amount are made proportional to the weight.

7. The mixing and adjusting method for foundry sand according to claim 6 , wherein
when water is supplied into the foundry sand, a leak water amount is corrected for each end of water pouring operation by a difference between a target amount of water that is to be supplied through a digital flow meter communicated with a water source and an accumulated flow rate measured by the digital flow meter, and
the leak water amount is caused by operation delay occurring when an electromagnetic valve communicated with the digital flow meter is closed.

8. The mixing and adjusting method for foundry sand according to claim 5 , wherein
the first relationship is corrected by a difference between the CB value and an estimated CB value of the first mixed sand which is determined based, at least in part, on the first relationship.

9. The mixing and adjusting method for foundry sand according to claim 8 , wherein
the first relationship is a function indicating a relationship between the predetermined amount of water and the electric resistance of the foundry sand, and
an intercept and an inclination of the function are corrected upon the correction of the first relationship.

10. The mixing and adjusting method for foundry sand according to claim 9 , wherein
when water is supplied into the foundry sand, a leak water amount is corrected for each end of water pouring operation by a difference between a target amount of water that is to be supplied through a digital flow meter communicated with a water source and an accumulated flow rate measured by the digital flow meter, and
the leak water amount is caused by operation delay occurring when an electromagnetic valve communicated with the digital flow meter is closed.

11. The mixing and adjusting method for foundry sand according to claim 8 , wherein
when water is supplied into the foundry sand, a leak water amount is corrected for each end of water pouring operation by a difference between a target amount of water that is to be supplied through a digital flow meter communicated with a water source and an accumulated flow rate measured by the digital flow meter, and
the leak water amount is caused by operation delay occurring when an electromagnetic valve communicated with the digital flow meter is closed.

12. The mixing and adjusting method for foundry sand according to claim 5 , wherein
the CB value of the first mixed sand comprises a first CB value, and wherein
the method further comprises
measuring a second CB value of the second mixed sand;
calculating a CB value variation ratio that is a ratio of a variation in the second CB value;
determining an average value of CB value variation ratios that have heretofore been calculated; and
correcting the second relationship by a diffe

Assignees

• Sintokogio Ltd

Inventors

• Ogura Yuichi
• Takishita Koji
• Harada Hisashi

Classifications

• B22C5/18

  Plants for preparing mould materials · CPC title

• B28C7/0409

  taking regard of the moisture content of the solid ingredients; Moisture indicators · CPC title

• B28C7/12

  Supplying or proportioning liquid ingredients · CPC title

• B22C19/04

  Controlling devices specially designed for moulding machines · CPC title

• B22C5/0463

  Plants · CPC title