JPS62214909A - Mold for vulcanizing tire - Google Patents

Abstract

PURPOSE:To uniformize the vulcanizing temperature of a tire and improve the performance thereof as well as its productivity by a method wherein an annular recess is formed on the main body of a mold at a position corresponding to the thick portion of the tire and a specified high heat transfer metal is embedded into the annular recess. CONSTITUTION:Annular recesses 5a, 5b are formed on a top force 1a and a bottom force 1b at the outer peripheral surface corresponding to the thick portion of a tire W or the part of the tire W whereat vulcanizing is most delayed while annular high heat conductive metals 6a, 6b, provided with the heat conductivity of 250kcal.m<-1>.h<-1>.deg<-1> or more under the temperature of 0 deg.C, are embedded into the annular recesses 5a, 5b. Further, the high heat conductive metals 6a, 6b are embedded so as to contact with platens 2a, 2b with the sectional area of 0.015m<2> with a distance at least more than 20% of a distance between the surfaces of the plattens 2a, 2b and the surface of a tire profile whereby the degree of vulcanizing of the tire W may be uniformized.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a tire curing mold, and more specifically to a platen-type vulcanizer configured to uniformize the tire vulcanization temperature. This invention relates to a tire curing mold.

[Prior art]

In recent years, the vulcanization method for small tires is to vulcanize and mold tires by heating the mold body using a platen (vulcanization hot platen) equipped with a heating medium placed at the top and bottom of the mold body. A platen type vulcanizer is commonly used.

In addition, each part of the tire has different times to reach proper vulcanization and different degrees of vulcanization at the same time due to differences in gauge and material, so making these times and degrees of vulcanization uniform is important for tire performance. This is desirable because it improves productivity and improves productivity.

By the way, in the past, for the purpose of improving tire performance and productivity, for example, Japanese Utility Model Application Publication No. 57-187727 (method of dividing the steam chamber of a platen in the circumferential direction), Japanese Patent Application Publication No. 52-117383 ( A method of fabricating a chamber in a mold), Japanese Utility Model Application Publication No. 54-154377 (a method of embedding a heat vibrator), etc. have been proposed.

However, with the above method of dividing the steam chamber of the platen in the circumferential direction, there is a problem in that it is difficult to freely control the temperature of each part of the tire. However, there are problems in that it is difficult to install the heat pipe into an existing mold, and the equipment becomes complicated to adjust the temperature of each of the multiple chambers. There is a difference in the heat transmission efficiency of the heat pipe depending on the vertical relationship between the upper mold and the lower mold, that is, the heat receiving side and the heat radiating side, causing problems such as a temperature difference, and these problems have been clarified as a result of experiments and the like.

[Purpose of the invention]

This invention was devised by paying attention to such conventional problems, and its purpose is to uniformize the vulcanization temperature of tires during tire vulcanization in a platen type vulcanizer. The present invention provides a tire curing mold designed to improve tire performance and productivity.

[Structure of the invention]

In order to achieve the above object, the present invention has a tire vulcanizing mold which heats a mold body and vulcanizes a tire using a platen equipped with a heating medium disposed at the upper and lower parts of the mold body. In the mold, an annular recess is formed in the mold body corresponding to the thick part of the tire, and the inside of the annular recess has a thermal conductivity of 250 kcal -ra -'·h-' at 0°C.
The gist is that a metal with a high thermal conductivity of -d e g-' or higher is buried and provided.

[Embodiments of the invention]

The present invention will be described in detail below based on the accompanying drawings.

The attached drawings show a model made of iron (thermal conductivity: 5) in which this invention is implemented.
0 kcal -ts-1h-' ・de g-') A partial cross-sectional view of a tire curing mold body 1 is composed of an upper mold 1a and a lower mold 1b. On the upper and lower surfaces thereof, platens 2a and 2b equipped with a heating medium (not shown) are provided. Further, 3a and 3b are bead rings of the tire W made of iron, and 4a and 4b are made of aluminum (thermal conductivity: 175 kcalm -' -h-鵞-
d e g-') tread ring is shown.

An annular recess is formed on the outer peripheral surfaces of the upper mold 1a and the lower mold 1b corresponding to the thick part of the tire W (part of the tire shoulder in this embodiment), that is, the part where the vulcanization of the tire W is delayed the most. 5a, 5b are formed, and in these annular recesses 5a, 5b,
Thermal conductivity at 0°C is 250 kcal-m −' ・
Ring-shaped high heat conductive metal 6a with h-deg-1 or more
, 6b (for example, copper) is buried.

Further, the high heat conductive metals 6a and 6b have a cross-sectional area (0,0
By making contact with platens 72a, 2b at 15r/) and further embedding at least 20% of the distance between the surface of platens 2a, 2b and the tire profile surface, the degree of vulcanization of tire W can be made uniform. be.

Note that the shape of the high heat conductive metals 6a and 6b is not limited to the ring shape as described above, but may be columnar (furthermore, as a means for fixing the high heat conductive metals 6a and 6b, the upper mold 1a and the lower mold 1
b or to the platens 2a and 2b. A heat insulating space 7a, 7b is provided between the annular recess 5a, 5b and the outer side surface of the high heat conductive metal 6a, 6b.
is formed.

As mentioned above, the thermal conductivity of the part of the tire W where vulcanization is the slowest is 250 kcal・m−1・h−1・de
By embedding the ring-shaped high heat conductive metals 6a and 5b of g-' or more, it is possible to speed up the temperature rise in the part where the vulcanization temperature rise is the slowest, thereby shortening the vulcanization time of the entire tire. This makes it possible to lower the degree of vulcanization of the portions that conventionally received excessive heat, that is, the thinner portions of the tire W.

For this reason, the vulcanized tire can be more uniformly vulcanized, and the tire performance can be significantly improved.

Next, the graph explanatory diagram of FIG. 2 compares the temperature curve during vulcanization of the part where vulcanization was delayed the most in the conventional method with the example of the present invention. It is clear that the

Further, the results of an indoor durability test using the tire showing the measurement results of the above-mentioned vulcanization temperature were as follows.

〔Effect of the invention〕

The present invention provides a tire vulcanization mold of the type that vulcanizes and molds a tire by heating the mold body using a platen equipped with a heating medium disposed at the top and bottom of the mold body as described above. An annular recess is formed in the mold body corresponding to the thick part of the tire, and the thermal conductivity at 0°C is 250 kcal-m −'-h-' ・d e g-'
Since the above-mentioned high heat conductive metal is buried and provided, the tire vulcanization temperature can be made uniform during tire vulcanization, thereby improving tire performance and productivity.

[Brief explanation of drawings]

Fig. 1 is a partially enlarged cross-sectional view of the main body of a tire curing mold in which the present invention is implemented, and Fig. 2 shows the temperature curve during vulcanization of the part where vulcanization was delayed the most in the conventional case. It is a graph explanatory diagram compared with an example. 1... Tire curing mold body, 2a, 2b...
Platen, 5a, 5b... Annular recess, 6a, 6b...
・High heat conductive metal, W...tire.

Claims (1)

[Claims] A tire vulcanizing mold is a mold for vulcanizing a tire by heating the mold body using a platen equipped with a heating medium disposed at the upper and lower parts of the mold body. An annular recess is formed in the corresponding mold body, and the thermal conductivity at 0°C is 250 kcal m^-^ in this annular recess.
A tire curing mold characterized in that a metal having a high thermal conductivity of 1.k^-^1.deg^-^1 or more is embedded therein.