JP2016179639A - Method for preheating tire vulcanizing mold - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for preheating a tire vulcanizing mold capable of efficiently preheating a tire vulcanizing mold by suppressing energy consumption.SOLUTION: An outside surface of a tire vulcanizing container 1 is heated by attaching each mold 10 to the tire vulcanizing container 1 comprising a segment 3 which is attached to the outer peripheral surface of a plurality of respective selector molds 11 annularly arranged, a lifting and lowering plate 4 to which an upper side mold 12a is attached, a bottom plate 5 to which a lower side mold 12b is attached and a container ring 2 which vertically moves and arranging a heat radiation suppressing material 6 at a position covering the tire molding surfaces S of the molds 10.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a method for preheating a tire vulcanization mold, and more particularly to a method for preheating a tire vulcanization mold that can efficiently preheat a tire vulcanization mold while suppressing energy consumption. .

  In the tire manufacturing process, green tires are successively vulcanized. When tires having different specifications (shape, size, etc.) are vulcanized by the same vulcanizer, the tire vulcanization mold installed in the vulcanizer is replaced with a different tire vulcanization mold. When the mold is replaced in this way, the vulcanization of the green tire cannot be started unless the mold is at a certain high temperature. Therefore, a time loss occurs in the process until the predetermined temperature is reached. If the vulcanization is interrupted for some reason while the green tire is continuously vulcanized, a time loss occurs in the process for the same reason when starting to vulcanize a new green tire.

  In order to reduce the time loss of such a process, the mold is preheated. In the conventional mold preheating method, for example, the outer peripheral surface of a vulcanizing container to which a mold is attached is heated by a hot plate. The region where the temperature is actually desired to be increased is the tire molding surface of the mold (tire molding surface), but the heat supplied from the hot plate is radiated from the tire molding surface of the mold, so the tire molding surface is heated to a predetermined temperature. There is a problem that it takes more time than necessary. In other words, useless energy is consumed for preheating the mold.

  Another method for preheating the mold is to supply a heating fluid to the vulcanizing bladder disposed inside the mold while heating the outer peripheral surface of the vulcanizing container attached with the mold with a hot plate. There has been proposed a method of heating from the tire molding surface side of the mold in a state where it is not brought into contact with the tire molding surface of the mold (see Patent Document 1). In this method, a large amount of energy is required because the hot plate and the vulcanizing bladder serve as heat sources. Further, even if a heating fluid is supplied to the vulcanizing bladder, heat from the heating fluid is radiated toward the tire molding surface of the mold through the vulcanizing bladder, so that the thermal conductivity is extremely deteriorated. In addition, this method also has a problem that preheating cannot be performed unless a vulcanizing bladder is installed in the mold.

JP 2009-90501 A

  An object of the present invention is to provide a method for preheating a tire vulcanization mold that can efficiently preheat a tire vulcanization mold while suppressing energy consumption.

  In order to achieve the above object, a tire vulcanization mold preheating method according to the present invention is a tire vulcanization mold preheating method in which a tire vulcanization mold is attached inside a tire vulcanization container and the mold is preheated. The heat radiation suppressing material is disposed at a position covering the tire molding surface formed on the mold, and the outer surface of the tire vulcanizing container is heated.

  According to the present invention, the heat radiation suppressing material disposed at a position covering the tire molding surface formed in the tire vulcanization mold attached to the inside of the tire vulcanization container is supplied from the outer surface of the vulcanization container. Heat is prevented from radiating from the tire molding surface of the mold. Therefore, it is advantageous to raise the temperature of the tire molding surface of the mold in a short time even by heating from the outer surface of the tire vulcanizing container. Therefore, energy consumption can be suppressed and the tire molding surface of the mold can be efficiently preheated. Along with this, time loss in the vulcanization process can be reduced, which contributes to improvement in tire productivity. Moreover, preheating can be performed without installing a vulcanizing bladder inside the mold.

  Here, for example, the heat dissipation suppressing material can be disposed in contact with the tire molding surface, or the heat dissipation suppressing material can be disposed at a distance from the tire molding surface. In the former case, it is possible to further suppress heat dissipation from the tire molding surface of the mold. In the case of the latter, the freedom degree of the shape of the heat dissipation suppression material to use increases.

  For example, glass wool or foam is used as the heat dissipation suppressing material. Alternatively, vulcanized tires can be used. As the vulcanized tire, one vulcanized by a mold having the same tire molding surface as the mold can be used. When such a vulcanized tire is used, the vulcanized tire that functions as a heat dissipation suppressing material can be brought into close contact with the tire molding surface of the mold.

  The tire vulcanization container can be preheated before being installed in a vulcanizer equipped with a vulcanizing bladder, or the tire vulcanizing container can be used as a vulcanizer equipped with a vulcanizing bladder. The preheating can be performed in the installed state. In the former case, since the vulcanizer is not occupied for preheating the mold, the tire productivity does not decrease due to the shortage of the vulcanizer. In the latter case, it is possible to avoid a decrease in the temperature of the preheated mold until the tire vulcanizing container is installed in the vulcanizer.

  When the preliminary heating is performed in a state where the tire vulcanizing container is installed in a vulcanizer equipped with a vulcanizing bladder, the vulcanizing bladder is expanded by a non-heated and pressurized medium injected therein. The expanded vulcanizing bladder can be brought into contact with the heat dissipation suppressing material. As a result, the heat radiation suppressing material can be easily brought into close contact with the tire molding surface of the mold.

It is a longitudinal cross-sectional view which illustrates the container for tire vulcanization to which the mold for tire vulcanization was attached. It is a top view which illustrates the sector mold and segment of FIG. It is a right half longitudinal cross-sectional view which illustrates the container for tire vulcanization | cure of FIG. 1 which has arrange | positioned the heat dissipation suppression material in the position which covers the tire molding surface of a tire vulcanization mold. It is a right half longitudinal cross-sectional view of the container for tire vulcanization | cure of FIG. 1 which shows the modification of a heat dissipation suppression material. It is a right half longitudinal cross-sectional view of the container for tire vulcanization | cure of FIG. 1 which shows another modification of a heat dissipation suppression material. It is a right half longitudinal cross-sectional view of the container for tire vulcanization | cure of FIG. 1 which shows another modification of the heat dissipation suppression material. It is a right half longitudinal cross-sectional view which illustrates the container for tire vulcanization | cure of FIG. 1 which has arrange | positioned the heat dissipation suppression material in the position which covers the tire molding surface of the mold for tire vulcanization | curing before installing in a vulcanizer. It is a graph which shows the preheating required time by the difference in a heat dissipation suppression material. It is a graph which shows the heat retention effect by the difference in the magnitude | size of the clearance gap between the thermal radiation suppression material and the tire molding surface of a mold.

  Hereinafter, a method for preheating a tire vulcanizing mold according to the present invention will be described based on an embodiment shown in the drawings, taking as an example the case of preheating a sectional type mold.

  A sectional type tire vulcanization mold 10 (hereinafter referred to as a mold 10) is attached to the inside of a tire vulcanization container 1 (hereinafter referred to as a container 1) illustrated in FIG. As illustrated in FIG. 2, the mold 10 includes a plurality of (for example, about eight) sector molds 11 that are annularly arranged to mold a tire tread, an annular upper side mold 12 a that molds a tire sidewall, and It is comprised by the lower side mold 12b. A tire molding surface S is formed on the inner surface of each mold 10. An alternate long and short dash line in the figure indicates an annular center line CL of the sector mold 11 arranged in an annular shape.

  In this embodiment, the container 1 is installed in the vulcanizer 8. The vulcanizer 8 has a central mechanism 9 provided with a vulcanizing bladder 9 a, and the vulcanizing bladder 9 a is disposed inside the mold 10.

  The container 1 includes a segment 3 attached to the outer peripheral surface of each sector mold 11, a lift plate 4 to which an upper side mold 12a is attached, a bottom plate 5 to which a lower side mold 12b is attached, and a container ring 2 that moves up and down. And. The elevating plate 4 and the container ring 2 are moved up and down independently by a hydraulic cylinder or the like. The outer peripheral surface of the segment 3 and the inner peripheral surface of the container ring 2 are inclined so as to spread downward toward the outer peripheral side.

  The segment 3 is suspended from the lifting plate 4 so as to be slidable in the horizontal direction. The outer peripheral inclined surface of the segment 3 and the inner peripheral inclined surface of the container ring 2 are slidably engaged, and the segment 3 slides in the horizontal direction when the container ring 2 moves up and down.

  The segment 3 that has been moved downward and abutted against the upper surface of the bottom plate 5 slides on the upper surface of the bottom plate 5 by moving the container ring 2 downward, so that each sector mold 11 is moved to the annular center line CL. In contrast, it is configured to move forward.

  By moving the container ring 2 further downward and moving the sector mold 11 together with the respective segments 3 forward with respect to the annular center line CL, the respective sector molds 11 can be assembled in an annular shape, and the upper side mold 12a and the lower side mold 12a. The mold 10 is clamped by being assembled with the side-side mold 12b.

  A heating body 7 such as a hot plate is installed on the outer surface of the container 1. The heating body 7 is installed on each of the upper surface, the side surface, and the lower surface of the container 1 so as to correspond to the outer position of each mold 10.

  Hereinafter, an example of a procedure for preheating the mold 10 according to the present invention will be described.

As illustrated in FIG. 3, the heat radiation suppressing material 6 is disposed at a position covering the tire molding surface S of each sector mold 11, the upper side mold 12 a and the lower side mold 12 b. As the heat dissipation suppressing member 6, for example, a member excellent in heat insulation, such as a fiber heat insulating material such as glass wool, or a foamed heat insulating material of various materials such as resin, rubber, or elastomer can be used. A heat insulating material having a thermal diffusion coefficient (temperature diffusivity) of 1 mm ² / s or less is preferably used as the heat dissipation suppressing material 6.

  Although it is desirable to cover the entire surface of the tire molding surface S of the mold 10 with the heat dissipation suppressing member 6, for example, it is sufficient that the area of 70% or more of the entire surface of the tire forming surface S can be covered with the heat dissipation suppressing member 6. In this embodiment, the heat radiation suppressing material 6 is placed in contact with (in close contact with) the tire molding surface S of the mold 10.

  Then, the container 1 to which the mold 10 is attached is placed in the vulcanizer 8 and is clamped. In this state, the heating body 7 attached to the outer surface of the container 1 is heated (heated). The heating temperature of the heating body 7 is, for example, 150 ° C. to 190 ° C.

  Heat is supplied to the mold 10 from the heating body 7 and preheated. Here, the heat radiation suppressing material arranged at a position covering the tire molding surface S of the mold 10 suppresses the heat supplied from the heating body 7 from radiating from the tire molding surface S of the mold 10. Therefore, even if it heats only from the outer surface of the container 1, the tire molding surface S of the mold 10 can be raised in a short time. Therefore, energy consumption can be suppressed and the tire molding surface S of the mold 10 can be efficiently preheated.

  When the tire molding surface S of the mold 10 rises to a predetermined temperature due to preheating, the mold 10 is opened and a green tire is installed therein, then the mold 10 is closed and then clamped to vulcanize the green tire. To start. Therefore, according to the present invention, the waiting time until the tire molding surface S of the mold 10 rises to a predetermined temperature is shortened, and the time loss in the vulcanization process can be reduced, which contributes to the improvement of tire productivity. .

  As in this embodiment, when the heat radiation suppressing material 6 is arranged in contact with the tire molding surface S of each mold 10, a gap (air layer) is formed between the tire molding surface S of each mold 10 and the heat radiation suppressing material 6. ) Almost disappears. Therefore, there is no gap where heat is dissipated, and heat dissipation from the tire molding surface S of the mold 10 can be further suppressed.

  As illustrated in FIG. 4, the heat radiation suppressing material 6 can be disposed with a space from the tire molding surface S of each mold 10. Even if there is a gap between the heat radiation suppressing material 6 and the tire molding surface S of each mold 10, if it is not excessive (if the gap is, for example, 20 mm or less), a considerable heat radiation suppressing effect can be obtained. In this case, there is an advantage that the degree of freedom of the shape of the heat radiation suppressing material 6 that can be used increases.

  As illustrated in FIG. 5, a vulcanized tire 6 a can be used as the heat dissipation suppressing member 6. Since the vulcanized rubber can store a large amount of heat, it can function as the heat radiation suppressing material 6. As the vulcanized tire 6a, those vulcanized by a mold having the same tire molding surface S as these molds 10 can also be used. In this case, the vulcanized tire 6 a that functions as the heat dissipation suppressing member 6 can be brought into close contact with the tire molding surface S of the mold 10. Therefore, it is advantageous for further suppressing heat dissipation.

  The heat radiation suppressing material 6 illustrated in FIG. 6 is a rubber or resin cylindrical film having elasticity. The heat dissipation suppressing member 6 is disposed on the outer surface of the vulcanizing bladder 9a. Then, a non-heated and pressurized medium such as air is injected into the vulcanizing bladder 9a to expand the bladder 9a, thereby bringing it into contact with the heat radiation suppressing material 6. Thus, by using the vulcanizing bladder 9a, the heat radiation suppressing material 6 can be stably disposed at a position covering the tire molding surface S of each mold 10. Further, if the vulcanizing bladder 9a is greatly expanded, the heat radiation suppressing material 6 can be easily placed in contact with the tire molding surface S of the mold 10. In particular, it is possible to make the heat radiation suppressing material 6 adhere to the tire molding surface S of each mold 10 with almost no gap between the tire molding surface S of each mold 10 and the heat radiation suppressing material 6. .

  In the embodiment described above, since the mold 10 is preheated with the container 1 installed in the vulcanizer 8, vulcanization of the green tire is started as soon as the tire molding surface S of the mold 10 rises to a predetermined temperature. be able to. Therefore, there is no problem that the temperature of the mold 10 preheated before the container 1 is installed in the vulcanizer 8 is lowered.

  As illustrated in FIG. 7, before installing the container 1 in the vulcanizer 8, by disposing the heat radiation suppressing material 6 at a position covering the tire molding surface S of each mold 10 and heating the heating element 7. The tire molding surface S of each mold 10 can also be preheated. For example, this preheating is performed at a preheating station located in the vicinity of the vulcanizer 8. In this case, the vulcanizer 8 is not occupied for preheating of the mold 10, so that the tire productivity is not reduced due to the shortage of the vulcanizer.

  As the heat dissipation suppressing member 6, a rigid inner mold (metal core) on which a green tire is fitted during vulcanization can also be used. Since the rigid inner mold is made of metal, it has better thermal conductivity than the rubber vulcanized bladder 9a. Therefore, by heating the outer side surface of the container 1 and heating the rigid inner mold, it is possible to quickly preheat while suppressing heat radiation from the tire molding surface S of the mold 10. Therefore, if the rigid inner mold is used, the energy required for preheating the mold 10 can be minimized.

  The present invention is not limited to a sectional type mold, and can also be applied to preheating a so-called two-division type tire vulcanization mold that is divided in the tire width direction on the tire equatorial plane.

  As shown in Fig. 1, the same mold is attached to the container and installed in the vulcanizer, and the outer surface of the container is heated under the same conditions. The mold preheating required time was measured for the four methods (conventional example, Examples 1 to 3). In Example 3, the rigid inner mold was heated to about 80 ° C. The measurement results are shown in FIG.

  In the graph shown in FIG. 8, the vertical axis indicates the time required for the tire molding surface of the mold to reach a certain target temperature from a certain initial temperature (necessary preheating time). Show. The smaller the index value, the shorter the required preheating time.

  From the results shown in FIG. 8, it can be seen that Examples 1 to 3 can shorten the time required for preheating as compared with the conventional example.

  Moreover, the same mold is attached to the container as illustrated in FIG. 1 and installed in the vulcanizer, the outer surface of the container is heated under the same conditions, and the same heat radiation suppressing material is used. The heat retention effect on the tire molding surface was measured by varying the size of the gap between the mold and the tire molding surface. In the graph shown in FIG. 9, the vertical axis indicates the heat retention effect on the tire molding surface as an index with a reference 100 when there is no gap between the two (both are in close contact). It means that the smaller the index value, the better the heat retaining effect.

  From the results shown in FIG. 9, if the clearance between the heat dissipation suppressing material and the tire molding surface of the mold is 20 mm or less, there is a heat retention effect of 50% or more compared to the case where there is no clearance between the two, sufficient heat retention It turns out that there is an effect.

DESCRIPTION OF SYMBOLS 1 Tire vulcanization container 2 Container ring 3 Segment 4 Elevating plate 5 Bottom plate 6, 6a Heat radiation suppression material 7 Heating body 8 Vulcanizer 9 Central mechanism 9a Vulcanization bladder 10 Tire vulcanization mold 11 Sector mold 12a Upper side Mold 12b Lower side mold S Tire molding surface

Claims (9)

A tire vulcanization mold preheating method for attaching a tire vulcanization mold to a tire vulcanization container and preheating the mold,
A method for preheating a tire vulcanization mold, comprising disposing a heat radiation suppressing material at a position covering a tire molding surface formed on the mold and heating an outer surface of the tire vulcanization container.   The method for preheating a tire vulcanization mold according to claim 1, wherein the heat dissipation suppressing material is disposed in contact with the tire molding surface.   The method for preheating a tire vulcanization mold according to claim 1, wherein the heat dissipation suppressing material is disposed with a space from the tire molding surface.   The method for preheating a tire vulcanization mold according to any one of claims 1 to 3, wherein glass wool or foam is used as the heat dissipation suppressing material.   The method for preheating a tire vulcanization mold according to any one of claims 1 to 3, wherein a vulcanized tire is used as the heat dissipation suppressing material.   The method for preheating a tire vulcanization mold according to claim 5, wherein the vulcanized tire is vulcanized by a mold having the same tire molding surface as the mold.   The method for preheating a tire vulcanization mold according to any one of claims 1 to 6, wherein the preheating is performed before the tire vulcanization container is installed in a vulcanizer equipped with a vulcanization bladder.   The method for preheating a tire vulcanization mold according to any one of claims 1 to 6, wherein the preheating is performed in a state where the tire vulcanization container is installed in a vulcanizer equipped with a vulcanization bladder.   The tire vulcanization mold preheating method according to claim 8, wherein the vulcanization bladder is expanded by a non-heated and pressurized medium injected therein, and the expanded vulcanization bladder is brought into contact with the heat radiation suppressing material.

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