Claims
- 1. A method of judging a quality of an injection molded product, comprising the steps of:
- measuring a temperature T of an operating member of an injection molding machine during a pressure holding step at a time t elapsed after commencement of said pressure holding step of said injection molding machine;
- measuring a pressure P of an operating member of said injection molding machine at said time t;
- repeating said measuring temperature and measuring pressure steps at different times during said pressure holding step;
- calculating a time function A=f(t) using both said temperature T and said pressure P, where A is a function from the group consisting of T/P, P/T, T.times.P, T+P or T.+-.P at said different times;
- obtaining a reference time function having values at said different times of said pressure holding step that represent a satisfactory product;
- comparing said reference time function with the calculated time functions; and
- determining that said injection molded product is bad when said calculated time function differs from said reference time function, at any of said different times, by more than a predetermined amount.
- 2. The method according to claim 1 wherein said temperature T is a temperature of resin in a mold cavity of said injection molding machine.
- 3. The method according to claim 1 wherein said temperature T is a temperature of a metal mold of said injection metal mold.
- 4. The method according to claim 1 wherein said temperature T is a temperature of a barrel of said injection molding machine.
- 5. The method according to claim 1 wherein said temperature T is a temperature of resin in a nozzle of said injection molding machine.
- 6. The method according to claim 1 wherein said temperature T is a temperature of a nozzle of said injection molding machine.
- 7. The method according to claim 1 wherein said pressure P is a pressure of resin in a mold cavity of said injection molding machine.
- 8. The method according to claim 1 wherein as said pressure P is a pressure of resin in a barrel or nozzle of said injection molding machine.
- 9. The method according to claim 1 wherein said temperature T and pressure P are measured in a time band, a predetermined time later than commencement of said pressure holding step.
- 10. The method according to claim 1 wherein said temperature T and said pressure P are measured at two or more times elapsed after commencement of said pressure holding step.
- 11. An apparatus for determining a quality of an injection molded product, comprising:
- means for determining a plurality of times t during a pressure holding step of an injection molded product;
- means for measuring a temperature T of an operating member of an injection molding machine at each said time t;
- means for measuring a pressure P of injection molding at each said time t;
- means for calculating a function using both said temperature T and said pressure P to calculate the function at each said time t;
- means for storing a reference function having values at said plurality of times which represent a satisfactory product;
- means for comparing said function with said reference function; and
- alarm means for signalling that said product is defective when said comparing performed by said comparing means indicates that any of said functions at said plurality of times differ from said reference function for a corresponding time by more than a predetermined amount.
Priority Claims (3)
Number |
Date |
Country |
Kind |
62-296370 |
Nov 1987 |
JPX |
|
62-296371 |
Nov 1987 |
JPX |
|
62-296372 |
Nov 1987 |
JPX |
|
Parent Case Info
This is a continuation of application No. 07/275,987, filed on Nov. 25, 1988, which was abandoned upon the filing hereof.
US Referenced Citations (8)
Foreign Referenced Citations (1)
Number |
Date |
Country |
3608973 |
Sep 1987 |
DEX |
Continuations (1)
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Number |
Date |
Country |
Parent |
275987 |
Nov 1988 |
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