Heat build-up/fatigue measuring method for viscoelastic body and hydraulic servo flexometer

A heat build-up/fatigue measuring method which measures heat build-up/fatigue of a viscoelastic body, in which

• a strain and a stress applied to a test piece are detected,
• static and dynamic loads applied to the test piece are controlled by a hydraulic servo mechanism based on the detected strain and stress,
• a loss tangent of the test piece is obtained based on the detected strain and stress, and
• a relationship between a minimum value of loss tangent and a time point at which blow-out occurs is obtained in advance, so that the time point at which blow-out occurs is obtained from the minimum value of the loss tangent.

A hydraulic servo flexometer for measuring heat build-up/fatigue of the viscoelastic body, comprising:

• an upper anvil and a lower anvil arranged in a thermostatic chamber to oppose each other to sandwich a viscoelastic test piece;
• a hydraulic servo mechanism for moving said upper anvil or said lower anvil in a vertical direction to apply static and dynamic loads to the test piece;
• hydraulic servo control means for controlling said hydraulic servo mechanism based on a preset test condition;
• a temperature detector for measuring a temperature of the test piece;
• a strain detector for detecting a strain applied to the test piece;
• a stress detector for detecting a stress applied to the test piece;
• a transfer turret which is arranged between said upper anvil and said lower anvil, has an insertion hole formed therein to insert a test piece therein, is provided with fixing means for holding and fixing the test piece inserted in the insertion hole, and rotates intermittently;
• a rotary driving unit for rotating said transfer unit;
• opening means for opening said fixing means, thereby releasing the test piece;
• and
• a control unit for controlling said hydraulic servo control means, said rotary driving unit, and said opening means to fix the test piece at a supply position with fixing means, rotating said transfer turret until a test position and releasing the test piece, fixing the test piece again with fixing means after the test, and rotating said transfer turret until a discharge position and releasing the test piece.

A hydraulic servo flexometer for measuring heat build-up/fatigue of a viscoelastic test piece, comprising:

• an upper anvil and a lower anvil arranged in a thermostatic chamber to oppose each other to sandwich said viscoelastic test piece;
• a hydraulic servo mechanism for moving said upper anvil or said lower anvil in a vertical direction to apply static and dynamic loads to the test piece;
• hydraulic servo control means for controlling said hydraulic servo mechanism based on a preset test condition;
• a temperature detector for measuring a temperature of the test piece;
• a strain detector for detecting a strain applied to the test piece;
• and
• a stress detector for detecting a stress applied to the tests piece;
• wherein said temperature detector comprises a vertically movable temperature sensor having a pointed distal end, temperature sensor driving means for vertically moving said temperature sensor, and a control unit which performs a control operation in accordance with a detection value of said strain detector so that a distal end of said temperature sensor is located at a center of the test piece.

A hydraulic servo flexometer for measuring heat build-up/fatigue of a viscoelastic test piece, comprising:

• an upper anvil and a lower anvil arranged in a thermostatic chamber to oppose each other to sandwich a viscoelastic test piece;
• a hydraulic servo mechanism for moving said upper anvil or said lower anvil in a vertical direction to apply static and dynamic loads to the test piece;
• hydraulic servo control means for controlling said hydraulic servo mechanism based on a preset test condition;
• a temperature detector for measuring a temperature of the test piece;
• a strain detector for detecting a strain applied to the test piece;
• and
• a stress detector for detecting a stress applied to the test piece;
• wherein said hydraulic servo flexometer is accommodated and fixed in a hollow frame, and a vibration absorbing member is packed in said frame.

A hydraulic servo flexometer for measuring heat build-up/fatigue of a viscoelastic test piece, comprising:

• an upper anvil and a lower anvil arranged in a thermostatic chamber to oppose each other to sandwich a viscoelastic test piece;
• a hydraulic servo mechanism for moving said upper anvil or said lower anvil in a vertical direction to apply static and dynamic loads to the test piece;
• hydraulic servo control means for controlling said hydraulic servo mechanism based on a preset test condition;
• a temperature detector for measuring a temperature of the test piece;
• a strain detector for detecting a strain applied to the test piece;
• a stress detector for detecting a stress applied to the test piece;
• and
• an air circulation plate arranged on a surface opposing air blowing means of said thermostatic chamber to circulate air along a side wall.