Operation of a tire vulcanization system

Patent metadata

Field	Value
Publication number	US-10688742-B2
Application number	US-201716070108-A
Country	US
Kind code	B2
Filing date	Jan 6, 2017
Priority date	Jan 14, 2016
Publication date	Jun 23, 2020
Grant date	Jun 23, 2020

Abstract

In an electric vulcanization process, open loop and closed loop control modes can be used for controlling a heater output.

First claim

What is claimed is:

1. A method of operating a tire vulcanization system during a curing cycle in which a tire is vulcanized in a mold for a predetermined duration under pressure, the tire vulcanization system including an axially movable plate and a stationary plate connected by a bladder disposed inside a tire to be vulcanized and at least partially delineating a cavity in which a heating medium circulates, with a fan and a heater being immersed in the heating medium and the heater having one or more heating elements that provide energy to the heating medium traversing thereover, the method comprising:
providing data, for a current curing cycle, that includes at least a bladder exchange surface area S for a tire being vulcanized, a temperature differential ΔT between the bladder and the heating medium, and a coefficient of exchange by forced convection h;
detecting a heating medium temperature in the cavity during the current curing cycle;
on the basis of the detected heating medium temperature, calculating a thermal flux ϕ that traverses the bladder during a subsequent curing cycle as a function of at least the bladder exchange surface area S and the temperature differential;
comparing the calculated thermal flux with a required thermal flux to be realized upon commencement of the subsequent curing cycle; and
adjusting the heating medium temperature in the cavity when a comparison between the calculated thermal flux and the required thermal flux indicates a non-equivalence therebetween.

2. The method of claim 1 , further comprising:
configuring at least one temperature sensor to perform the detecting step and to generate one or more temperature signals indicative of the detected heating medium temperature, the at least one temperature sensor being mounted on or near the stationary plate immediately proximate an egress from which the fan delivers the heating medium and that is disposed along an exit path from the fan into the cavity; and
configuring a monitoring system to receive the one or more temperature signals and send one or more control signals to perform the adjusting.

3. The method of claim 1 , further comprising:
initiating a timer upon introducing the heating medium into the cavity for monitoring an elapsed time of the duration under pressure.

4. The method of claim 3 , wherein the adjusting includes attaining a predicted final heating medium temperature upon termination of the current curing cycle.

5. The method of claim 3 , wherein the adjusting includes at least one of adjusting a fan speed, adjusting a heating medium pressure and adjusting a heater output, and
wherein adjusting the heater output is accomplished by adjusting a heater supply voltage.

6. The method of claim 5 , wherein the adjusting includes increasing the heater output during a phase of the elapsed time necessary to attain and maintain a predetermined temperature level of the heating medium, during a predetermined time less than or equal to the duration under pressure.

7. The method of claim 1 , further comprising, based on the detected heating medium temperature, calculating an energy required to cure the tire being vulcanized as a function of at least the energy to be supplied for vulcanization of an inner tire surface, energy lost upon opening the mold between the current curing cycle and the subsequent curing cycle, and energy lost by the vulcanization system during curing.

8. The method of claim 7 , wherein the calculated energy is delivered upon commencement of the duration under pressure.

9. The method of claim 8 , wherein, during at least a portion of the duration under pressure, a heating medium pressure increases and wherein, during another portion of the elapsed time, the heating medium pressure remains constant.

10. The method of claim 9 , wherein the adjusting includes terminating the adjusting so as to attain a predicted final heating medium temperature upon lapse of the duration under pressure.

11. The method of claim 7 , further comprising, on the basis of predicted energy, calculating an adjustment as a function of the energy lost by the vulcanization system and a period during which the mold is open.

12. The method of claim 1 , wherein the heating medium comprises nitrogen.

13. The method of claim 1 , further comprising providing at least one programmable controller in signal communication with the vulcanization system for programming at least one of the current curing cycle and the subsequent curing cycle.

Assignees

• Michelin & Cie

Inventors

• Boncompagne Thibault
• Simonelli Thomas
• Guerin Franck
• Ferrand Jean-Charles

Classifications

• B29D2030/0677

  Controlling temperature differences · CPC title

• B29D30/0662 Primary

  Accessories, details or auxiliary operations · CPC title

• B29D2030/0675

  Controlling the vulcanization processes · CPC title

• B29D30/0654

  Flexible cores therefor, e.g. bladders, bags, membranes, diaphragms (elastic cores or mandrels for shaping of plastics B29C33/505; bags for isostatic pressing in compression moulding B29C43/12, B29C43/3642) · CPC title

• B29D2030/0669

  the fluids being circulated by a turbine type pump associated with the mould, e.g. positioned in the mould · CPC title