JPH0550435A - Preparation of tire - Google Patents

Abstract

PURPOSE:To perform simply and strongly vulcanization adhesion of a friction decreasing member to a tire by a method wherein a projection is inserted into each recessed part formed on each of a pair of vulcanization mold and a sheet- like raw material is fixed on each vulcanization mold and a green tire is placed and vulcanized in both vulcanization molds and the projection is removed from the sheet-like raw material. CONSTITUTION:In preparing a tire wherein a friction decreasing member 2 is fixed on each of left and right side walls 1, a sheet-like raw material 2A for the friction decreasing member projecting integrally a projection 3 to the outer face side is formed and the projection 3 is inserted into a recessed part 5 respectively formed on a pair of a vulcanization molds 4. Then, the sheet-like raw material 2A is fixed on each vulcanization mold 4 and a green tire 6 is placed and vulcanized in both vulcanization molds 4 and after vulcanization, the projection 3 is removed from the sheet-like raw material 2A.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a tire that can be used in, for example, a tire-driven crawler belt device in which a crawler belt is mounted on a plurality of wheel tires.

[0002]

2. Description of the Related Art For example, as disclosed in Japanese Utility Model Publication No. 52-28258, a tire drive type crawler belt device is mounted on a wheel equipped with a tire made of an elastic material such as rubber and a plurality of the wheel tires. The crawler belt is made of an elastic material such as rubber, and side guides are formed inside the left and right sides of the crawler belt to prevent the crawler belt from separating from the tire.

[0003]

A low-pressure tire is used as the above-mentioned wheel tire of the prior art, and there is an idea to use a high-pressure tire. However, the sidewall portion of the tire is not subjected to any processing. No, the frictional resistance of the sidewall remains high. Therefore, when the wheel tire receives side force during turning, etc., the sidewall part rises above the side guide part of the crawler belt, and it does not slide down due to frictional resistance, and the rise develops and comes off the crawler belt. is there.

This problem can be solved by making a friction reducing member into a sheet shape and adhering it to the sidewall portion of the wheel tire, and such a proposal has already been made. This proposed friction reducing member is made of Teflon (trade name of synthetic resin made by polymerizing ethylene tetrafluoride) and is bonded to a vulcanized tire via an adhesive. The strength is not higher than that of vulcanization adhesion and there is a possibility of peeling.

Therefore, as in the comparative example shown in FIG. 5, a hole 22 is formed in the sheet material of the friction reducing member 21, and the hole 2 is formed.
Insert a Teflon pin 23 into 2 and fix this pin 23 to the hole of the vulcanization mold to attach the sheet material to the vulcanization mold, and place the green tire in the vulcanization mold, A method of joining the friction reducing member 21 to the tire 24 when vulcanizing the green tire can be considered.

However, according to such a pin mounting method, the pin hole 22 must be formed in the friction reducing member 21, and the pin hole 22 remains after the manufacture, and the pin hole 22 remains in the tire during use. Since the stress is concentrated, cracking is likely to occur, the friction reducing member 21 may be radially deformed between the pin holes 22, and the sheet material of the friction reducing member may be circumferentially deformed during vulcanization. It may be pulled and broken from the pin hole 22.

An object of the present invention is to vulcanize a green tire by integrally providing a projection on the sheet material of the friction reducing member, fixing the sheet material to the vulcanization mold by the projection. A tire that can solve all of the above-mentioned various problems by sometimes vulcanizing and adhering the sheet-shaped material at the same time, and then removing the protrusions from the sheet-shaped material to form a friction reducing member without pin holes. It is to provide a manufacturing method of.

[0008]

A concrete means for solving the problem in the present invention is a method of manufacturing a tire in which a friction reducing member 2 is attached to left and right sidewall portions 1, and a protrusion 3 is integrally formed on the outer surface side. The sheet material 2A for the friction reducing member 2 is formed to protrude, and the protrusions 3 are inserted into the recesses 5 formed in each of the pair of vulcanization molds 4 to form each vulcanization mold 4.
The sheet-shaped raw material 2A is attached to the sheet-shaped raw material 2A, the green tires 6 are arranged in both vulcanization molds 4 and vulcanized, and the protrusions 3 are removed from the sheet-shaped raw material 2A after vulcanization.

[0009]

The pair of upper and lower vulcanization dies 4 are provided with the recesses 5 at the side wall corresponding portions, and the sheet-shaped material 2A of the friction reducing member 2 has the projection 3 integrally projected to the outer surface side.
When the protrusion 3 is inserted into the recess 5, the sheet-shaped material 2A
Will be attached to each vulcanizing mold 4, and in that state, when the green tires 6 are placed in both vulcanizing molds 4 and the molds are closed and vulcanized, the sheet-shaped material 2A having the protrusions 3 is attached. When the protrusions 3 are formed on the tire and the sheet-shaped material 2A of the tire after vulcanization is removed, the friction reducing member 2 is formed and the tire as a product is obtained.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. In FIG. 3, T is a tire made of an elastic material, which is mounted on the rim 16 to form a wheel tire, and is used for a rear wheel for driving, a front wheel, or an idler wheel arranged between the rear wheel and the front wheel, The crawler belt 14 formed of an elastic material is hung on the rear wheel and the idler wheel (or the front wheel) to form a tire-driven crawler belt device.

The crawler belt 14 is formed with projecting side guide portions 15 at regular intervals in the longitudinal direction on the inner periphery on both sides in the width direction. The side guide portions 15 contact the side wall portion 1 of the wheel tire. And prevent derailment with it. In the tire T, the tread portion 17 is flat and the outer peripheral portion of the sidewall portion 1 following the left and right shoulder portions 18 is tapered.

That is, the tire T has a maximum width in the tire radial direction center of the sidewall portion 1, and is gradually narrowed from the center of the left and right sidewall portions 1 to the tread portion 17 side. The outer peripheral portion of No. 1 is formed into a flat tapered surface and is a portion that engages with the side guide portion 15 of the crawler belt 14. This engaging portion is in surface contact with the side guide portion 15 when the crawler belt 14 is wound, and is in sliding contact with the side guide portion 15 when it is moved back and forth.

In order to reduce the frictional resistance between the side guide portion 15 and the side guide portion 15, a friction reducing member 2 is attached to the sidewall portion 1 of the tire T. The friction reducing member 2 is formed of a Teflon sheet and is vulcanized and adhered during vulcanization of the green tire. In FIGS. 1 to 3, 4 is a pair of upper and lower vulcanization dies, each of which has a recess 5 formed at the center in the radial direction of its corresponding sidewall portion. The concave portion 5 is a thin groove in the circumferential direction and is continuously formed in the circumferential direction.

2A is a sheet material for the friction reducing member 2,
The Teflon sheet is formed into a substantially disc shape, and the projection 3 is integrally projected from the inner peripheral edge of the disc to the outer surface side which is the outside of the tire T. The protrusion 3 has a shape corresponding to the recess 5, and is continuously formed in the tire circumferential direction. In addition to continuously forming the protrusions 3, this sheet material 2A has a structure shown in FIG.
As in the modified example shown in FIG. 3, the projections may be formed as intermittent projections protruding at regular intervals in the circumferential direction.

The sheet material 2A is formed so that the plate thickness and the plate width are uniform all over the circumference, and the plate thickness P is 1 to 3 mm. It becomes difficult to follow the movement of bending, and it is preferably about 2 mm. In addition, the projection 3 that serves as a fixing allowance for the sheet material 2A,
The thickness t is preferably 2 mm or more and the height h is preferably 2 mm or more,
The height h is best 4 mm, and the thickness t is the sheet material 2A.
It is easier to manufacture if the plate thickness P is set to be the same.

With respect to the two sheet materials 2A formed in such a shape, the vulcanization mold 4 is opened and the projections 3 are inserted into the recesses 5 of each vulcanization mold 4. Then, the sheet material 2A
Will be attached and fixed to each vulcanization mold 4. In that state, the green tire 6 that was made in advance
Is placed in both vulcanization dies 4, and when the vulcanization dies 4 are closed and vulcanized, the sheet material 2A is vulcanized and adhered to the green tire 6, and the tire T with the sheet material 2A having the protrusions 3 is attached.
Formed in. During this vulcanization, the sheet material 2A itself thermally expands and is closely fixed to the vulcanization mold 4, and is not affected by shaping and is not deformed.

When the protrusions 3 of the sheet material 2A that are protruding are removed from the vulcanized tire with a knife or the like for finishing, the crawler driving tire T as a product having no pin holes and unevenness in the sidewall portion 1 You can (Experimental Example) A tire T manufactured according to the present invention and FIG.
The tire with a pin hole manufactured by the method shown in
Drum diameter 80 with the equivalent of 5.00-12-8PR
It was mounted on a 0 mm drum, an internal pressure was 2.0 kgf / m ² , a vehicle speed was 40 km / h, a load was 200 kgf, and a slat was fixed to the drum.

As a result, in the case of the tire with pin holes, 152
While the crack occurred from the pin hole 22 at 0 km, the tire T of the present invention did not crack even after traveling 4000 km and the friction reducing member 2 did not peel off. The present invention is not limited to the above embodiment, but can be variously modified. For example, the friction reducing member 2 is made of a synthetic resin other than Teflon, which has low surface friction resistance, durability, weather resistance, and good adhesiveness to rubber, and the protrusion 3 is formed from the outer peripheral edge of the sheet material 2A. Alternatively, the friction reducing member 2 may be projected from the middle portion in the width direction by integral molding or adhesion, or the friction reducing member 2 may be extended to the shoulder portion 18.

Further, the outer peripheral side of the sidewall portion 1 of the tire T is formed into a flat taper surface so as to prevent the tire T from climbing up on the side guide portion 15 when a side force is applied to the tire T. Although it is designed to have a guide function of being housed in the crawler belt 14, the friction reducing member 2
When the frictional resistance can be significantly reduced by the above, the tire may be curved in a gentle arc like a general tire.

Further, the tire T of the present invention may be used not only as a wheel tire for a tire-driven crawler belt device but also as a running tire in which the crawler belt 14 is not hung like a general tire. It is possible to prevent the sidewall portion 1 from being damaged when it comes into contact with the like, or to reduce the abrasion of the sidewall portion 1 when traveling on a sandy or gravel road.

[0021]

According to the present invention described in detail above, the sheet material 2A for the friction reducing member 2 having the projection 3 integrally projected on the outer surface side is formed and formed on each of the pair of vulcanization molds 4. The protrusion 3 is inserted into the recess 5 formed, the sheet material 2A is attached to each vulcanization mold 4, the green tires 6 are placed in both vulcanization molds 4 and vulcanized. Since the protrusions 3 are removed from the material 2A to form the tire T with the friction reducing member 2, the friction reducing member 2 can be easily and firmly vulcanized and adhered to the tire, which is stronger than the adhesive bonding. Since the finished product does not have pin holes in the friction reducing member 2, there is no fear of cracking and the durability can be improved.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a tire after vulcanization according to the present invention.

FIG. 3 is a cross-sectional view when used as a crawler driving tire.

FIG. 4 is a cross-sectional view showing a tire after vulcanization in which protrusions are intermittently formed.

FIG. 5 is a cross-sectional view showing a comparative example of the present invention.

[Explanation of symbols]

 1 Sidewall part 2 Friction reducing member 2A Sheet material 3 Protrusion 4 Vulcanizing mold 5 Recess 6 Green tire

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁵ Identification number Office reference number FI technical display location B29D 30/72 8824-4F // B29K 21:00 105: 24 B29L 9:00 4F

Claims (1)

[Claims] 1. A method for manufacturing a tire in which a friction reducing member (2) is attached to left and right side wall portions (1), the friction reducing member (2) integrally protruding on an outer surface side. The sheet-shaped material (2A) is formed, and the projections (3) are inserted into the recesses (5) formed in each of the pair of vulcanization molds (4), and each vulcanization mold (4) is sheet-shaped. It is characterized in that the material (2A) is attached, the green tires (6) are placed in both vulcanization molds (4) and vulcanized, and the projections (3) are removed from the sheet-shaped material (2A) after vulcanization. And a method for manufacturing a tire.