JP2015139898A - Method and device for measuring temperature of extruded rubber product - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and device for measuring the temperature of an extruded rubber product, achieving more accurate measurement of the internal temperature of an extruded rubber product immediately after extrusion from an extruder than before, without causing a negative effect in the subsequent process in a production line.SOLUTION: A metal wire 2 with a wire diameter of 0.2 mm or more and 0.5 mm or less internally having a thermocouple 6 is fixed to a die 8 installed on an extruder 7, and stretched in front of the extrusion port 9 of the die 8. An unvulcanized extruded rubber product R is extruded from the extrusion port 9, so as to be temporarily incised by the metal wire 2. Immediately after the incision and before the incision surfaces Rf of the extruded rubber product R are joined to each other, the temperature of the incised region is measured by the thermocouple 6.

Description

  The present invention relates to a temperature measurement method and a temperature measurement device for a rubber extrudate, and more specifically, the internal temperature of a rubber extrudate immediately after being extruded from an extruder can be measured with higher accuracy than before. In addition, the present invention relates to a temperature measurement method and a temperature measurement device for a rubber extrudate that can be measured without affecting the next process of the production line.

  When manufacturing rubber products such as tires, there is an extrusion process in which unvulcanized rubber is extruded by an extruder. In such an extrusion process, the unvulcanized rubber is extruded from an extrusion port of a die attached to the extruder, thereby forming a rubber extrudate molded into a predetermined shape. Here, for example, when unvulcanized rubber compounded with silica is extruded, the internal temperature of the rubber extrudate has a great influence on the stability of the rubber extrudate, for example, the inside of the rubber extrudate foams due to a temperature rise due to plasticization. It is important to accurately grasp the internal temperature of the rubber extrudate because local deformation of the rubber extrudate generated when plasticized by the screw of the extruder appears in the internal temperature distribution of the rubber extrudate. .

  Various methods for measuring the internal temperature of the rubber extrudate have been proposed (see, for example, Patent Document 1). In the measuring method proposed in Patent Document 1, the surface temperature of the rubber extrudate is measured at at least two locations, and the internal temperature of the rubber extrudate is determined based on the measured value and the thickness of the rubber extrudate. However, this method does not actually measure the internal temperature of the rubber extrudate, but predicts it, so there is a limit to increasing the measurement accuracy.

  In the method of directly measuring the internal temperature by inserting a thermometer probe directly into a rubber extrudate immediately after extrusion, the probe temperature affects the measurement temperature. It is necessary to take measures such as heating up to the temperature. Alternatively, it is also conceivable that the rubber extrudate immediately after extrusion is cut with a cutting tool such as a blade and the cut surface is measured with an infrared thermometer or the like. However, since the cutting tool such as a blade has a large contact area with the rubber extrudate (the contact time is long), the temperature difference between the rubber extrudate and the cutting tool affects the measurement temperature, and the temperature of the cut surface changes. Therefore, there is a problem that the internal temperature of the rubber extrudate (the temperature of the cut surface) cannot be accurately measured. Further, in a production line using a rubber extrudate, there is a problem that the rubber extrudate cut by the cutting tool cannot be used in the next process as it is.

JP-A-11-151747

  The object of the present invention is to measure the internal temperature of a rubber extrudate immediately after being extruded from an extruder with higher accuracy than before and to measure without affecting the next process of the production line. Another object of the present invention is to provide a temperature measuring method and a temperature measuring device for a rubber extrudate.

  In order to achieve the above object, the method for measuring the temperature of a rubber extrudate according to the present invention comprises fixing a metal wire having a wire diameter of 0.2 mm or more and 0.5 mm or less having a thermocouple to a die installed in an extruder. The rubber extrudate is tensioned to the front of the extrusion port of the die, unvulcanized rubber extrudate is extruded from the extrusion port, and the rubber extrudate is temporarily incised by the metal wire. Before the cut surfaces are joined, the temperature of the cut portion is measured by the thermocouple.

  The apparatus for measuring a temperature of a rubber extrudate according to the present invention comprises a metal wire having a wire diameter of 0.2 mm or more and 0.5 mm or less arranged in front of a die extrusion port installed in an extruder, and the metal wire as the die. A fixing means for fixing and tensioning, and a thermocouple provided in the metal wire, a rubber extrudate extruded from the extrusion port is temporarily incised by the metal wire, and immediately after the incision, the rubber extrusion Before the cut surfaces of the objects are joined, the temperature of the cut portion is measured by the thermocouple.

  According to the present invention, a rubber wire extruded from an extruder by fixing a metal wire having a wire diameter of 0.2 mm or more and 0.5 mm or less to a die installed in the extruder, and tensioning the front surface of the extrusion port of the die. Since the object is temporarily incised by the metal wire, the contact area between the rubber extrudate and the metal wire becomes very small, and accordingly, the contact time becomes very short. Since the metal wire has a small diameter, the temperature of the rubber extrudate hardly changes even when the extruded rubber extrudate comes into contact. Thereby, the influence of the temperature of a metal wire can be minimized and the inside of the rubber extrudate immediately after extrusion can be exposed as a cut surface. Since the temperature of the incised portion is measured by a thermocouple immediately after the incision and before the incised surfaces of the rubber extrudates are joined, measurement with higher accuracy than before can be performed.

  In addition, the rubber extrudate temporarily cut by the metal wire is joined and integrated immediately after the cut. Therefore, the temperature-measured rubber extrudate can be used as it is sent to the next step of the production line. That is, in the present invention, since the rubber extrudate is only temporarily cut, the internal temperature of the rubber extrudate can be measured without affecting the next process of the production line using the rubber extrudate.

It is explanatory drawing which illustrates the temperature measuring apparatus of the rubber extrudate of this invention. It is a top view which expands and illustrates the metal wire periphery of FIG. It is a front view which expands and illustrates the die periphery of FIG. It is an enlarged view of a metal wire. 5A is a cross-sectional view taken along line AA in FIG. 4, and FIG. 5B is a cross-sectional view taken along line BB in FIG. It is explanatory drawing which shows the modification of a metal wire. It is explanatory drawing which illustrates a tension mechanism by a partial cross section view. It is explanatory drawing which illustrates the process of tensioning a metal wire with a tension mechanism. It is a graph which shows the surface temperature and internal temperature of the rubber extrudate which were measured.

  Hereinafter, the method and apparatus for measuring the temperature of a rubber extrudate according to the present invention will be described based on the embodiments shown in the drawings.

  The embodiment of the rubber extrudate temperature measuring device 1 of the present invention illustrated in FIGS. 1 to 3 has a metal wire 2 having a wire diameter of 0.2 mm or more and 0.5 mm or less, and the metal wire 2 attached to an extruder 7. A fixing means 3 for fixing and tensioning the die 8 and a thermocouple 6 provided in the metal wire 2 are provided. The extruder 7 is a known extruder such as a single screw or a twin screw, and has a screw installed therein. A take-up conveyor 10 is disposed in front of the extrusion port 9 formed in the die 8.

  In this embodiment, further, a regulating member 4 installed in the vicinity of the extrusion port 9 of the die 8 and a tension mechanism 5 that constantly presses and tensions the metal wire 2 in a direction opposite to the extrusion direction of the rubber extrudate R. (5a, 5b, 5c).

  The metal wire 2 is disposed on the front surface of the extrusion port 9 of the die 8. In general, the shape of the extrusion port 9 has a width dimension larger than a thickness dimension. In this embodiment, the metal wire 2 extends in the thickness direction of the extrusion port 9 (vertical direction in FIG. 3) and is tensioned. As the metal wire 2, for example, a metal wire configured by twisting a plurality of metal filaments 2 a as exemplified in FIGS. 4 and 5 is used.

  As illustrated in FIGS. 4 and 5, the thermocouple 6 includes a temperature detection unit 6 a and a lead wire 6 b extending from the temperature detection unit 6 a, and is provided in the metal wire 2 having a twisted structure. In this embodiment, the metal wire 2 is configured by twisting a plurality of filaments 2a with the thermocouple 6 (temperature detection unit 6a) as a core. The lead wire 6 b extends from the middle position in the longitudinal direction of the metal wire 2 so as to protrude to the outside of the metal wire 2. The extended lead wire 6 b is connected to the data processor 11. Note that a cylindrical metal wire 2 may be used and a thermocouple 6 may be inserted into the metal wire 2.

  Of the outer peripheral surface of the metal wire 2, the portion located on the surface of the die 8 is covered with the film-like heat insulating material 2 b, and most of the portion located at the extrusion port 9 is not covered with the heat insulating material 2 b. . That is, the outer peripheral surface of the metal wire 2 and the die 8 are not in direct contact with each other, and the heat insulating material 2b is interposed. As the heat insulating material 2b, for example, a resin having a thermal conductivity of 0.17 W / (m · K) or less at 20 ° C. is used. The thickness of the heat insulating material 2b is 0.1 mm or less, for example, and is very small compared to the wire diameter of the metal wire 2.

  The fixing means 3 of this embodiment is a fixing screw 3a. The metal wire 2 is detachably fixed to the die 8 by the fixing means 3. The fixing means 3 may be any means as long as the metal wire 2 is fixed to the die 8 and is tensioned.

  The restricting member 4 is a metal plate, for example, and is detachably fixed to the die 8 with screws or the like. The regulating member 4 is fixed to the die 8 so as to cover the metal wire 2 and presses the metal wire 2. That is, the metal wire 2 is pressed against the die 8 by the regulating member 4 with the heat insulating material 2b interposed. For example, the restriction member 4 has a specification that does not easily bend so as to have rigidity higher than that of general carbon steel.

  The tension mechanism 5 is composed of, for example, a guide frame 5a and an adjustment screw 5b. By pressing the metal wire 2 guided by the guide frame 5a using the adjusting screw 5b, the metal wire 2 is always tensioned. Details will be described later.

  Next, the procedure of the measurement method of the present invention for measuring the internal temperature of the rubber extrudate R immediately after being extruded from the extruder 7 will be described.

  First, a predetermined amount of unvulcanized rubber and a compounding agent are charged into the extruder 7. These are mixed and kneaded by the extruder 7. The unvulcanized rubber that has been mixed and kneaded is softened to some extent (plasticized), shaped into the shape of the extrusion port 9 from the extrusion port 9, and extruded as a sheet of unvulcanized rubber extrudate R. Since the metal wire 2 is in tension on the front surface of the extrusion port 9, the central portion in the width direction of the rubber extrudate R is incised left and right by the metal wire 2.

  Since the metal wire 2 has a thermocouple 6 and has a thin diameter of 0.2 mm or more and 0.5 mm or less, contact with the rubber extrudate R when the rubber extrudate R extruded from the extruder 7 is incised. The area becomes very small, and accordingly, the contact time becomes very short. Therefore, even if the rubber extrudate R contacts the metal wire 2, the temperature of the rubber extrudate R hardly changes. Moreover, the metal wire 2 with a small diameter immediately becomes the same temperature as the temperature of the extruded rubber extrudate 2.

  The rubber extrudate R incised by the metal wire 2 is united by natural joining of the incised surfaces Rf immediately after being incised in the extruded flow. That is, the cut surfaces Rf of the rubber extrudate R are automatically joined together by the swell of unvulcanized rubber cut by the metal wire 2 (property to spread).

  Here, the thermocouple 6 (temperature detection unit 6a) installed in the metal wire 2 is a part (incised) immediately after the rubber extrudate R is cut and before the cut surfaces Rf of the rubber extrudate R are joined ( The temperature of the cut surface Rf) is measured. The temperature data measured by the temperature detector 6a is input to the data processor 11 through the lead wire 6b. The temperature of the cut surface Rf of the rubber extrudate R immediately after incision is the internal temperature of the rubber extrudate R immediately after extrusion. Since the outer peripheral surface of the metal wire 2 is covered with the heat insulating material 2b and is not in direct contact with the die 8, the heat of the die 8 transmitted to the metal wire 2 is slight. Therefore, the temperature detector 6a can accurately measure the internal temperature of the rubber extrudate R in real time by eliminating the influence of the temperature of the die 8.

  In this way, by measuring the temperature of the cut surface Rf of the rubber extrudate R with the thermocouple 6 immediately after the cut, it is possible to suppress the temperature of the cut surface Rf from being affected by the external environment or the like. Therefore, according to the present invention, it is possible to measure the internal temperature of the rubber extrudate R with higher accuracy than before. Since the temperature measuring device 1 of the present invention can be applied to an existing extruder 7, it has high versatility.

  After the rubber extrudate R is temporarily incised by the metal wire 2, the incision surfaces Rf are extinguished when the incision surfaces Rf are joined together, and are conveyed to the next process by the take-up conveyor 10. Therefore, the temperature-measured rubber extrudate R can be used as it is in the next process of the production line. That is, in the present invention, since the rubber extrudate R is only temporarily cut, the internal temperature of the rubber extrudate R can be measured without affecting the next process of the production line using the rubber extrudate R.

  Although the thermocouple 6 (temperature detection part 6a) is installed in the metal wire 2 illustrated in FIG. 4 without being exposed to the outside, the temperature detection part 6a is external to the metal wire 2 as illustrated in FIG. It can also be set in an exposed state. In the metal wire 2 illustrated in FIG. 6, the filaments 2a are twisted with a gap. Due to this twisted structure, the temperature detector 6a is exposed to the outside of the metal wire 2 from the gap between the filaments 2a. When the metal wire 2 having this structure is used, the temperature detection unit 6a can be brought into direct contact with the rubber extrudate R, which is more advantageous for improving measurement accuracy.

  The movement of the metal wire 2 is restricted by the restricting member 4 at both ends in the thickness direction of the extrusion port 9. Therefore, the metal wire 2 is restrained from swinging left and right while being pressed by the rubber extrudate R. Therefore, the rubber extrudate R can be stably incised at a predetermined position, and the internal temperature of the rubber extrudate R immediately after extrusion can be stably measured.

  In addition, when the wire diameter of the metal wire 2 is less than 0.2 mm, the metal wire 2 is easily cut by being pressed by the rubber extrudate 2, and the deflection of the metal wire 2 when pressed by the rubber extrudate R is increased. On the other hand, when the wire diameter of the metal wire 2 exceeds 0.5 mm, the contact area with the rubber extrudate R increases, and accordingly, the contact time also increases. Thereby, the temperature of the metal wire 2 affects the temperature of the cut surface Rf, which is disadvantageous for accurately measuring the internal temperature of the rubber extrudate R.

  Since the metal wire 2 continues to be pressed by the rubber extrudate R, the elongation may occur or the tension may be loosened. In such a case, the rubber extrudate R cannot be stably incised at a predetermined position. Therefore, in this embodiment, a tension mechanism 5 as illustrated in FIG. 7 is provided. The guide frame 5a constituting the tension mechanism 5 is formed with a guide hole through which the metal wire 2 is guided and a screw hole. The metal wire 2 passes through the guide hole, and the adjustment screw 5b passes through the screw hole. And the pressing piece 5c is inserted. A part of the guide frame 5 a is embedded in the die 8, and the guide hole through which the metal wire 2 passes is at the same level as the front surface of the die 8.

  As illustrated in FIG. 8, by rotating the adjustment screw 5 b and tightening it on the guide frame 5 a, the pressing piece 5 c is pushed in, and the pressing piece 5 c pushes the metal wire 2 opposite to the extrusion direction of the rubber extrudate R. Always press in the direction. In FIG. 8, the direction from left to right is the extrusion direction of the rubber extrudate R. By constantly pressing the metal wire 2 in the direction opposite to the extrusion direction in this way, the tension state of the metal wire 2 is always maintained, so that the rubber extrudate R can be cut more stably. The tensioning mechanism 5 can be provided not only at one end of the metal wire 2 but also at the other end. The direction in which the metal wire 2 is pressed in order to maintain the tension state of the metal wire 2 can be, for example, the same direction as the extrusion direction of the rubber extrudate R. It can be avoided that an additional burden is generated.

  When the rubber extrudate R is extruded at an extrusion speed of less than 10 cm / sec, the load on the metal wire 2 is not so large, but when it is extruded at an extrusion speed of 10 cm / sec or more, the load on the metal wire 2 is excessive. become. Therefore, when the extrusion speed of the rubber extrudate R is set to 10 cm / sec or more, it is preferable that the metal wire 2 is stretched in the thickness direction of the extrusion port 9 to be tensioned as illustrated in FIG. Although the tension direction of the metal wire 2 can be orthogonal to the width direction of the extrusion port 9 (intersection angle 90 °), it is inclined to some extent with respect to the width direction of the extrusion port 9 as illustrated in FIG. When intersecting (for example, intersecting angle of 45 ° to 80 °), it becomes easy to join the cut surfaces Rf that are temporarily cut by the metal wire 2.

  The internal temperature data of the rubber extrudate R obtained by the present invention can be used effectively when determining the optimum condition setting when the rubber extrudate R is extruded by the extruder 7. Further, since the temperature distribution inside the rubber extrudate R can be grasped, the high temperature portion of the rubber extrudate R can be cooled more intensively and used to prevent burns and to stabilize the member. Burns can be prevented and the yield of the rubber extrudate R can be improved, which contributes to energy saving and is also an ecological measure.

  When an unvulcanized rubber extrudate with the same specifications (width: about 180 mm, thickness: about 15 mm) was extruded under the same conditions using the same extruder, the surface temperature of the rubber extrudate immediately after extrusion was measured with a thermography device (comparison) Example) In addition, the temperature of the cut surface when the position of about 1/4 of the width dimension from the one end in the width direction of the rubber extrudate is temporarily cut left and right with a metal wire is a thermocouple built in the metal wire. Measurement (Example). To measure the temperature of the cut surface, a metal wire having a wire diameter of 0.4 mm was strained in the thickness direction on the front surface of the extrusion port using the same equipment as the temperature measuring device illustrated in FIGS. The measurement results are schematically shown in FIG. A broken line indicates a comparative example, and a solid line indicates an example.

  From the results shown in FIG. 9, it can be seen that the measurement temperature of the example is generally higher than that of the comparative example, and the internal temperature of the rubber extrudate immediately after extrusion can be accurately grasped.

DESCRIPTION OF SYMBOLS 1 Temperature measuring device 2 Metal wire 2a Filament 3 Fixing means 3a Fixing screw 4 Restriction member 5 Tension mechanism 5a Guide frame 5b Adjustment screw 5c Pressing piece 6 Thermocouple 6a Temperature detection part 6b Lead wire 6c Heat insulating material 7 Extruder 8 Die 9 Press Exit 10 Take-up conveyor 11 Data processing part R Rubber extrudate Rf Cut surface

Claims (12)

  A metal wire having a wire diameter of 0.2 mm or more and 0.5 mm or less, in which a thermocouple is installed, is fixed to a die installed in the extruder, and is tensioned on the front surface of the extrusion port of the die. While extruding the rubber extrudate and temporarily incising the rubber extrudate with the metal wire, immediately before the incision surfaces of the rubber extrudates are joined, A method for measuring a temperature of a rubber extrudate, wherein the temperature is measured by a thermocouple.   The method for measuring a temperature of a rubber extrudate according to claim 1, wherein the temperature detection part of the thermocouple is set in a state of being exposed to the outside of the metal wire.   The method for measuring a temperature of a rubber extrudate according to claim 1 or 2, wherein the metal wire is composed of a plurality of filaments, and the filaments are twisted with the thermocouple as a core.   The method for measuring a temperature of a rubber extrudate according to any one of claims 1 to 3, wherein a deflection of the metal wire pressed by the rubber extrudate is regulated by a regulating member attached in the vicinity of the extrusion port.   The method for measuring a temperature of a rubber extrudate according to any one of claims 1 to 4, wherein the metal wire is always pressed and tensioned in a direction opposite to an extruding direction of the rubber extrudate by a tension mechanism.   The method for measuring a temperature of a rubber extrudate according to any one of claims 1 to 5, wherein the metal wire is stretched and stretched in a thickness direction of the extrusion port, and the rubber extrudate is extruded at an extrusion speed of 10 cm / sec or more. .   A metal wire having a wire diameter of 0.2 mm or more and 0.5 mm or less arranged on the front surface of the die outlet installed in the extruder, a fixing means for fixing the metal wire to the die and tensioning, and the metal wire A rubber extrudate extruded from the extrusion port is temporarily incised by the metal wire, and immediately after the incision surface of the rubber extrudate is joined to the rubber extrudate. An apparatus for measuring a temperature of a rubber extrudate, wherein the temperature of an incised part is measured by the thermocouple.   The temperature measurement device for a rubber extrudate according to claim 7, wherein the temperature detection unit of the thermocouple is set in a state of being exposed to the outside of the metal wire.   The temperature measurement device for a rubber extrudate according to claim 7 or 8, wherein the metal wire is composed of a plurality of filaments, and the filaments have a twisted structure in which the thermocouple is used as a core.   The rubber extrusion according to any one of claims 7 to 9, further comprising a regulating member that is installed in the vicinity of the extrusion port and regulates the deflection of the metal wire by an unvulcanized rubber extrudate extruded from the extrusion port. An object temperature measuring device.   The temperature measuring device for a rubber extrudate according to any one of claims 7 to 10, further comprising a tensioning mechanism that constantly presses and tensions the metal wire in a direction opposite to an extruding direction of the rubber extrudate.   The temperature measurement of the rubber extrudate according to any one of claims 7 to 11, wherein the metal wire extends in the thickness direction of the extrusion port and is tensioned, and the extrusion speed of the rubber extrudate is set to 10 cm / sec or more. apparatus.

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