JP2006297875A - Rubber molding apparatus and rubber molding method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rubber molding apparatus and a rubber molding method which can improve the tackiness of a rubber member without applying a rubber cement. <P>SOLUTION: The rubber molding apparatus comprises a sheet board 10 which contacts the surface of an extruded stiffener rubber member 1 and cools the surface of the stiffener rubber member 1, and a bladder 3 which presses the stiffener rubber member 1 arranged around the perimeter on the sheet board 10 by expanding. The sheet board 10 comprises a water passage 14 which lets cooling water pass in the inside thereof, and molds the stiffener rubber member 1 contacted while cooling it. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a rubber molding apparatus and a rubber molding method for molding rubber in a process of producing a rubber member.

  Conventionally, there is a process of molding a rubber member in a production process of a rubber member such as a stiffener rubber used for a tire. At this time, zinc stearate may be deposited on the surface of the rubber member, which may reduce the tackiness (adhesiveness) of the rubber.

For this reason, the adhesiveness (rubber cement) is apply | coated to the surface of a rubber member, and it respond | corresponds to the fall of tackiness (for example, refer patent document 1).
JP-A-2-251586

  However, in order to apply rubber cement, various facilities such as local exhaust equipment and explosion-proof equipment are required, and management of the application state of rubber cement is complicated.

  Then, an object of this invention is to provide the rubber molding apparatus and rubber molding method which improve the tackiness of a rubber member, without apply | coating rubber cement in view of said problem.

  In order to solve the above-mentioned problems, the first feature of the present invention is that (a) a cooling jig that contacts the surface of the extruded rubber member and cools the surface of the rubber member, and (b) expands. Thus, the gist of the present invention is a rubber molding apparatus including a bladder that presses the rubber member disposed around the cooling member against the cooling jig.

  According to the rubber molding apparatus according to the first feature, by molding the rubber member while cooling, precipitation of zinc stearate on the rubber member surface can be suppressed, and the tackiness of the rubber member can be improved. For this reason, it is not necessary to apply rubber cement to the surface of the rubber member.

  In the rubber molding apparatus according to the first feature, the surface temperature of the cooling jig is preferably 40 ° C. or lower.

  In the rubber molding device according to the first feature, the temperature of the surface of the rubber member that contacts the cooling jig is preferably 70 ° C. or higher.

  In the rubber molding apparatus according to the first feature, the contact time between the cooling jig and the rubber member is preferably 5 seconds or more.

  Moreover, in the rubber molding apparatus according to the first feature, the cooling jig preferably has a water channel through which cooling water passes.

  The rubber molding apparatus according to the first feature can be suitably used for molding a tire stiffener rubber member.

  The second feature of the present invention is that (a) a step of cooling the cooling jig, (b) a step of disposing a rubber member around the bladder, and (c) inflating the bladder, The gist of the present invention is a rubber molding method including a step of pressing the surface against the cooling jig and a step (d) of molding the surface of the pressed rubber member while cooling.

  According to the rubber molding method according to the second feature, by molding the rubber member while cooling, precipitation of zinc stearate on the rubber member surface can be suppressed and the tackiness of the rubber member can be improved. For this reason, it is not necessary to apply rubber cement to the surface of the rubber member.

  ADVANTAGE OF THE INVENTION According to this invention, the rubber molding apparatus and rubber molding method which improve the tackiness of a rubber member can be provided, without apply | coating rubber cement.

  Next, embodiments of the present invention will be described with reference to the drawings. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals. However, it should be noted that the drawings are schematic and ratios of dimensions and the like are different from actual ones. Accordingly, specific dimensions and the like should be determined in consideration of the following description. Moreover, it is a matter of course that portions having different dimensional relationships and ratios are included between the drawings.

(Rubber molding equipment)
In the embodiment of the present invention, an apparatus for extruding and molding a stiffener rubber member used for a tire will be described. The stiffener rubber member is a bead portion reinforcing rubber extending in a tapered manner from the bead core toward the end of the tread portion along the carcass main body portion and the folded portion.

  FIG.1 (c) is sectional drawing of the rubber molding apparatus which concerns on embodiment of this invention. As shown in FIG. 1 (c), the rubber molding apparatus is in contact with the surface of the extruded stiffener rubber member 1 and expands with a sheet disk 10 (cooling jig) that cools the surface of the stiffener rubber member 1. And a bladder 3 for pressing the stiffener rubber member 1 disposed around the sheet board 10 against the sheet board 10. The sheet board 10 is a metal substantially disk-shaped jig. The bladder 3 is a device made of an elastic material that expands by injecting air into the inside, and plays a role of turning back the stiffener rubber member 1.

  The temperature of the surface of the stiffener rubber member 1 disposed around the bladder 3, that is, the temperature of the surface of the stiffener rubber member 1 immediately before contacting the sheet board 10 is 70 ° C. or more.

  The temperature of the surface of the sheet board 10 is 40 ° C. or less. Thus, the stiffener rubber member 1 is pressed onto the cooled sheet board 10 to mold the stiffener rubber member 1 while cooling.

  The contact time between the sheet board 10 and the stiffener rubber member 1 is preferably 5 seconds or more.

  As shown in FIG. 2, the sheet board 10 has a water channel 14 through which cooling water passes. The cooling water is introduced into the sheet board 10 from the cooling water inlet 12 by a pump, circulates through the water channel 14, and is discharged from the cooling water outlet 13. For example, the surface temperature of the sheet board 10 is about 30 ° C. by circulating cooling water of 25 to 30 ° C.

  In addition, the surface temperature of the sheet board 10 which does not have the conventional water channel 14 is 50-60 degreeC, and surface temperature falls 20-30 degreeC.

(Rubber molding method)
Next, a rubber molding method according to an embodiment of the present invention will be described with reference to FIG. Here, as described above, the case where the stiffener rubber member 1 used for a tire is produced as an example of the rubber member will be described.

  First, the sheet board 10 shown in FIG. 2 is cooled. Specifically, the cooling water is circulated through the water channel 14 inside the sheet board 10. On the other hand, as shown in FIG. 1A, the stiffener rubber member 1 is extruded from the extrusion portion 2. The stiffener rubber member 1 is a rubber member having a substantially triangular cross section.

  Next, the stiffener rubber member 1 is cut into a predetermined length, and the stiffener rubber member 1 is disposed around the bladder 3 as shown in FIG.

  Next, as shown in FIG. 1C, the surface of the stiffener rubber member 1 is pressed against the sheet board 10 by expanding the bladder 3. And it shape | molds, cooling the surface of the pressed stiffener rubber member 1.

(Action and effect)
According to the rubber molding apparatus and the rubber molding method according to this embodiment, the stiffener rubber member 1 is cooled at the time of molding by cooling the sheet disk 10 in contact with the train, and zinc stearate on the surface of the stiffener rubber member 1 is cooled. Precipitation can be suppressed. Therefore, the tackiness of the stiffener rubber member 1 can be improved, and the conventional cement application is not required.

  In the rubber molding device according to the present embodiment, the temperature of the surface of the cooling jig is 40 ° C. or less. By making it 40 degrees C or less, tackiness can be improved reliably.

  In the rubber molding device according to the present embodiment, the temperature of the surface of the rubber member that contacts the cooling jig is 70 ° C. or higher. When the temperature is lower than 70 ° C., the cooling effect by the cooling jig is not exhibited so much.

  In the rubber molding device according to the present embodiment, the contact time between the cooling jig and the rubber member is 5 seconds or more. When the time is shorter than 5 seconds, the cooling effect by the cooling jig is not exhibited so much.

  Moreover, in the rubber molding apparatus according to the present embodiment, the cooling jig has a water channel through which the cooling water passes, so that the cooling jig can be efficiently cooled by the cooling water passing through the water channel.

  Moreover, the kind of rubber member molded by the rubber molding apparatus according to the present embodiment is not limited, but it can be suitably used particularly for a stiffener rubber member for tires.

  EXAMPLES Next, although an Example demonstrates this invention further in detail, this invention is not limited at all by these examples.

  The cooling water was passed through the water channel 14 of the sheet board 10 shown in FIG. 2 to change the temperature of the cooling water, thereby changing the temperature of the surface of the sheet board and measuring the tackiness. At this time, the rubber member used was a tire stiffener rubber member, which was formed into a sheet having a thickness of OOmm.

  In addition, two types of sheet discs 10 were used for the measurement, and each of the sheet discs 10 was a disc shape having a diameter of about 940 cm and a thickness of about 70 cm.

  The measurement results of the two types of sheet board 10 are shown in FIGS.

Here, tackiness was measured as follows. That is, the stiffener rubber member 1 immediately after contacting the sheet board 10 is wound around the ring. The wound rubber member and a rubber sheet having the same composition as the rubber member are pressure-bonded, and the adhesive force is measured. For example, force during crimping: 4.9 N; crimping time: 30 seconds; pulling speed: 30 mm / min; number of measurements: 5 times (the average value is adopted); measuring instrument: Toyo Seiki Seisakusho Picumatac Tester Measurements can be made under conditions. 3 and 4 show the adhesive force (g) per 1 cm ² .

  As shown in FIG. 3, even when the cement was not applied (cementless in the figure), the average was 1165 g, and the adhesive strength was larger than the average of 980 g when the current cement was applied.

  Similarly, in the sheet board 10 shown in FIG. 4, even when no cement is applied (cementless in the figure), the average is 1134 g, and the adhesive strength is larger than the average 995 g when the current cement is applied. Had.

  In addition, when cement was applied, the adhesive strength was further improved.

  Therefore, it was confirmed that the tackiness of rubber can be improved by using the sheet disk 10 cooled at the time of molding.

It is a figure for demonstrating the rubber molding method which concerns on this embodiment. It is a model top view of the sheet board of the rubber molding apparatus which concerns on this embodiment. It is a figure for demonstrating the effect of the rubber molding apparatus which concerns on this embodiment (the 1). It is a figure for demonstrating the effect of the rubber molding apparatus which concerns on this embodiment (the 2).

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Stiffener rubber member, 2 ... Extrusion part, 3 ... Bladder, 10 ... Sheet board, 11 ... Cooling water exit, 12 ... Cooling water entrance, 14 ... Waterway

Claims (7)

A cooling jig for contacting the surface of the extruded rubber member and cooling the surface of the rubber member;
And a bladder that presses the rubber member disposed around to the cooling jig by expanding the rubber member.   The rubber molding apparatus according to claim 1, wherein the temperature of the surface of the cooling jig is 40 ° C. or less.   The rubber molding apparatus according to claim 1, wherein the temperature of the surface of the rubber member that contacts the cooling jig is 70 ° C. or higher.   The rubber molding apparatus according to any one of claims 1 to 3, wherein a contact time between the cooling jig and the rubber member is 5 seconds or more.   The rubber molding apparatus according to any one of claims 1 to 4, wherein the cooling jig has a water channel through which cooling water passes.   The rubber molding apparatus according to claim 1, wherein the rubber member is a tire stiffener rubber member. Cooling the cooling jig;
Arranging a rubber member around the bladder;
A step of pressing the surface of the rubber member against the cooling jig by inflating a bladder;
And a step of molding while cooling the surface of the pressed rubber member.

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