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US5135688A Expired / Lapsed US ⏱️ 0.0 years remaining

Fuzzy inference thermocontrol method for an injection molding machine with a plurality of means for heating or cooling

Assignee: Nissei Plastic Industrial Co Ltd
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Filing: 1991-10-02
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Granted: 1992-08-04
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Expires: 2011-10-02
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Abstract

Abstract To eliminate a temperature overshoot or an undershoot during thermocontrol of thermocontrolled components, e.g. an injection cylinder, with respect to an object temperature in each operating status of the injection molding machine, the Fuzzy Control theory is used for controlling the injection molding machine. By using the Fuzzy Control theory, the object temperature of the thermocontrolled components can be attained with practically eliminated overshoot and undershoot.

Inventors

  • 👤 Nobuyuki Nakamura
  • 👤 Kiyoto Takizawa
  • 👤 Masashi Suganuma

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-05 04:38
CPC Classifications
B; B29; B29C; B29C45/00; B29C45/17; B29C45/76; B29C45/78; Y; Y10; Y10S; Y10S706/00; Y10S706/90

Claims Analysis

Total Claims: 10
Claim 1
Independent Claim 275 words
A thermocontrol method for an injection molding machine having a plurality of means for heating or cooling, which are arranged at prescribed intervals, so as to control thermocontrolled components to maintain an object temperature corresponding to an operating status of the injection molding machine, comprising the steps of: detecting the operating status of the injection molding machine and the temperature of the thermocontrolled components thereof; calculating a first deviation between the object temperature of the thermocontrolled components corresponding to the present status of the injection molding machine and the present temperature detected, and the rate of deviation change between the present first deviation and the previous first deviation; calculating a second deviation between an object temperature of separating parts, which are parts between the thermocontrolled components, and the present temperature thereof; performing fuzzy inference to define a control value for the means for heating or cooling by inferring the status of the injection molding machine, the first deviation calculated, the rate of deviation change and the second deviation wherein the status of the injection molding machine, the first deviation, the rate of deviation change, the second deviation and the control value of the means for heating or cooling are defined as fuzzy variables, and wherein the inference is based both on rules governing a mutual relationship among groups within membership functions, and membership functions which have groups to which are previously assigned optional probabilities which correspond to respective optional values; calculating an actual control value of the means for heating or cooling based on the fuzzy inference and controlling the temperature of the plurality of means for heating or cooling with the actual control value.
Claim 2
Dependent Claim 275 words
A thermocontrol method for an injection molding machine having a plurality of means for heating or cooling, which are arranged at prescribed intervals, so as to control thermocontrolled components to maintain an object temperature corresponding to an operating status of the injection molding machine, comprising the steps of: detecting the operating status of the injection molding machine and the temperature of the thermocontrolled components thereof; calculating a first deviation between the object temperature of the thermocontrolled components corresponding to the present status of the injection molding machine and the present temperature detected, and the rate of deviation change between the present first deviation and the previous first deviation; calculating a second deviation between an object temperature of separating parts, which are parts between the thermocontrolled components, and the present temperature thereof; performing fuzzy inference to define a control value for the means for heating or cooling by inferring the status of the injection molding machine, the first deviation calculated, the rate of deviation change and the second deviation wherein the status of the injection molding machine, the first deviation, the rate of deviation change, the second deviation and the control value of the means for heating or cooling are defined as fuzzy variables, and wherein the inference is based both on rules governing a mutual relationship among groups within membership functions, and membership functions which have groups to which are previously assigned optional probabilities which correspond to respective optional values; calculating an actual control value of the means for heating or cooling based on the fuzzy inference and controlling the temperature of the plurality of means for heating or cooling with the actual control value.
Claim 3
Dependent Claim 22 words
The thermocontrol method for an injection molding machine according to claim 1, wherein the thermocontrolled components are an injection cylinder or molds.
Claim 4
Dependent Claim 25 words
The thermocontrol method for an injection molding machine according to claim 2, wherein the injection cylinder includes an injection nozzle provided to an end thereof.
Claim 5
Dependent Claim 35 words
The thermocontrol method for an injection molding machine according to claim 1, wherein each membership function is divided into a plurality of groups which have mutually overlapping sectors when the membership functions are graphically depicted.
Claim 6
Dependent Claim 21 words
The thermocontrol method for an injection molding machine according to claim 4, wherein the overlapped sectors are triangular when graphically depicted.
Claim 7
Dependent Claim 26 words
The thermocontrol method for an injection molding machine according to claim 1, wherein the status of the injection molding machine is controlled by a programmable controller.
Claim 8
Dependent Claim 21 words
The thermocontrol method for an injection molding machine according to claim 1, wherein the means for heating is an electric heater.
Claim 9
Dependent Claim 22 words
The thermocontrol method for an injection molding machine according to claim 1, wherein the means for cooling is a water circulation pipe.
Claim 10
Dependent Claim 29 words
The thermocontrol method for an injection molding machine according to claim 1, wherein the membership functions and the rules are previously stored in a memory unit of a computer.

References Cited (Backward Citations)

US3822867A Cited
US4094940A Cited
US4707310A Cited
US4899288A Cited
US4841459A Cited
JPS6348691A Cited
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US4911629A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1995-08-04 1996-02-03 1996-08-04 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1999-08-04 2000-02-03 2000-08-04 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2003-08-04 2004-02-03 2004-08-04 $7700.00 Window Closed / Lapsed

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