JPH01297301A - Flap for tyre and its manufacture - Google Patents

Abstract

PURPOSE:To enhance the durability of a flap interposed between the tube and the rim of a tyre and provided with a hole through which a valve is guided to pass by burying in the flap a reinforcing plate of high rigidity provided with a through-hole communicated with the hole. CONSTITUTION:A flap 16 is interposed between the rim and the tube of a tyre and provided with a cylindrical portion 17 engaged to the periphery of the rim, and a pair of wing portions 18, 19 engaged to the inner face of the bead portion of the tyre, and the same is also provided with a hole 20 formed at one portion of its periphery, hole which extends radially and through which a valve is guided to pass. In this case, a reinforcing plate 22 of high rigid material is buried inside the flap 16. The reinforcing plate 22 is formed of a rectangular portion 23 being parallel to the cylindrical portion 17 and each of extension portions 24, 25 which extends form each edge of the rectangular portion 23 to the respective center portions of the wing portions 18, 19 of the flap, and on the center portion of the rectangular portion 23 is a through-hole 26 is formed coaxial with the hole 20 and communicated with the hole.

Description

DETAILED DESCRIPTION OF THE INVENTION -■ This invention relates to a tire flap and a method for manufacturing the same.

Generally speaking, the rim on which a pneumatic tire is mounted has valve holes formed at l locations around the circumference, into which valves for filling internal pressure are loosely fitted into the tube. When the pneumatic tire to be used is a large tire such as a truck or bus tire, a portion of the flap bulges outward from the valve hole due to high internal pressure and heat radiation from the brake drum. This can cause cracks and jamming in the tube. In order to prevent such a situation, conventionally, a rubberized cloth is attached to the flap around the hole through which the valve passes, thereby reinforcing the flap in contact with the valve hole.

- However, in order to attach the rubber sheet as mentioned above, the flap is attached by cleaning the part with an organic solvent and then applying an adhesive, while for the rubberized cloth, it is punched out into a predetermined shape. The problem is that it is necessary to apply post-adhesive and then attach such rubberized cloth to the flap, resulting in a large number of steps and manpower, resulting in high processing costs. There is a point. Moreover, when used for a long time,
Another problem is that the rubberized fabric may peel off from the flap due to fatigue, deterioration, etc.

This invention can be manufactured easily and quickly, and
It is an object of the present invention to provide a flap whose performance does not deteriorate even after long-term use, and a method for manufacturing the flap.

Further, such a purpose is to provide an annular tire flap which is interposed between the tube and rim of a pneumatic tire and has a hole through which a valve passes through at one location on the circumference, the flap having the hole in the center. A rubber sheet is attached to at least one surface of the tire flap and the reinforcing plate, in which a high-rigidity reinforcing plate is formed with a through-hole communicating with the tire flap, which is embedded in the flap near the hole, and then this reinforcing plate is attached. This can be achieved by a manufacturing method in which the flap is manufactured by storing the flap in a mold containing a cavity having the same shape as the flap, and then injecting rubber into the cavity.

1. When manufacturing the tire flap according to this invention,
First, a highly rigid reinforcing plate with a through hole formed in the center is prepared, and a rubber sheet is attached to at least one surface of this reinforcing plate. Here, at least one surface on which the rubber sheet is pasted is the side on which the reinforcing plate moves due to the rubber when the rubber described later is injected into the cavity, and generally it is difficult for the rubber to go around the reinforcing plate to the flap. This is the side with the thinner wall thickness up to the surface. The rubber sheet may be attached to both surfaces of the reinforcing plate.Next, the reinforcing plate with the rubber sheet attached is placed in a mold having a cavity having the same shape as the flap, and then, Rubber is injected into the cavity.

Thereby, a flap is produced and the reinforcing plate is embedded within this flap. here.

As mentioned above, since a rubber sheet is attached to at least one surface of the reinforcing plate, even if the rubber injected into the cavity presses the reinforcing plate, this rubber sheet will prevent the reinforcing plate from moving, and as a result, the reinforcing plate will not move. 0 Next, such a flap is interposed between the tube and the rim, but at this time, the flap is formed at one location on the circumference of the flap. Pass the valve of the tube through the hole in the hole and the through hole in the reinforcing plate. As a result, the flap near the valve is strongly reinforced by the reinforcing plate, and the flap in this area will not bulge out of the valve hole formed in the rim. Moreover, the reinforcing plate is buried within the flap. Because of this, the flap does not come off even after long periods of driving, making it highly durable.

1 light 1 Hereinafter, one embodiment of the present invention will be described based on the drawings.

In Figure 1.2.3, summer is a rim, and a large pneumatic tire 2 used for trucks and buses is mounted on this rim 1. This tire 2 has a pair of bead portions 3 seated on a rim 1, a pair of sidewall portions 4 extending radially outward from each bead portion 3, and a tread portion 5 spanning these sidewall portions 4.
8 is the tire inner chamber s surrounded by the rim l and the tire 2
It is a hollow donut-shaped tube housed inside the tube 8, and inside this tube 8 there is a valve 1 attached to the tube 8.
0 through high pressure, e.g. 4 Kg/Cj to 7 Kg/[
It is filled with an internal pressure of about j. ! 1 is an oblong valve hole formed in the rim 1, and this valve hole 11
The valve 10 is loosely fitted in the middle of the valve 10, and as a result, changes in the position of the valve 10 due to changes in internal pressure, etc. are allowed.
1B is an annular tire flap interposed between the rim 1 and the tube 8;
a cylindrical portion 17 that engages with the outer periphery of the tire, and a pair of wing portions 18 and 19 that extend radially outward from both axial ends of the cylindrical portion 17 and engage with the inner surface of the bead portion 3 of the tire 2. , the tips of these wing parts 18.18 are connected to the tire 2
The wing portions 18 and 19 are sharp so as not to damage the tube 8 during transfer. The flap 1B is made of rubber and prevents the tube 8 from coming into contact with the rim 1 and the valve hole 11 when the tire 2 is transferred, thereby preventing the tube 8 from being damaged. Also, this flap 1
A hole 20 extending in the radial direction is formed at one location same as above in e,
A portion of the valve 10 passes through the hole 20. 22 is completely buried in the flap 1B to prevent damage to the tube 8, i.e., fuller, butt 6.
This reinforcing plate 22 has a rectangular part 23 located inside the cylindrical part 17 and parallel to the cylindrical part 17, a wing part 18, ! The reinforcing plate 22 is made of a thin metal plate made of aluminum, iron, copper, etc. Constructed from highly rigid materials such as wire mesh or heat-resistant plastics. A through hole 26 communicating with and coaxial with the hole 20 is formed in the center of the rectangular portion 23. As a result, the reinforcing plate 22 is located near the hole 20 and covers the entire valve hole 11. can do.

Further, a cylindrical portion 27 coaxial with the through hole 26 is formed around the through hole 26, and the tip of the cylindrical portion 27 is spaced apart from the outer periphery of the flap 16 by a distance ML. Further, this reinforcing plate 22 is arranged inside the flap 18 so that the wall thickness U of the flap 1B from the rectangular portion 23 to the inner periphery of the flap 16 is thinner than the wall thickness T of the flap 18 from the rectangular portion 23 to the outer periphery of the flap 16. It is buried in Further, the rectangular portion 23 of the reinforcing plate 22 is formed with a large number of coupling holes 28 arranged in parallel, and the rubber in these coupling holes 28 is located on the inner surface of the reinforcing plate 22 with the rubber located on the outer surface of the reinforcing plate 22. The reinforcing plate 22 and the flap 16 are connected to the rubber.
to strongly combine.

Next, the operation of one embodiment of the present invention will be explained.

When manufacturing the flap 1B as described above, first, as shown in FIG. 4, a rubber sheet 31 is attached to at least one surface of the reinforcing plate 22. here,
At least one surface to which the rubber sheet 31 is pasted is the surface on which the reinforcing plate 22 is moved by the rubber when the rubber is injected into the cavity of the mold as described later, and generally it is a surface on which it is difficult for the rubber to go around. The thin wall thickness U side is the inner circumferential surface of the reinforcing plate 22 in this embodiment. And, the wall thickness of this rubber seam) 31 is the flap 1 when it becomes a product.
The thickness is equal to the thickness of B, and in this embodiment, the thickness is equal to the thickness U. Note that the above-mentioned rubber sheets may be attached to both surfaces of the reinforcing plate 22 if necessary, and a cylindrical rubber ring 32 is fitted around the cylindrical portion 27.
The distance between the tip of this rubber ring 32 and the tip of the cylindrical portion 27 is equal to the pressure @L. Next, this rubber sheet 31 is pasted, and the cylindrical portion 27 of the reinforcing plate 22 into which the rubber ring 32 is fitted are fitted to the pins 30 of the outer mold 2S as shown in FIG.
The mold 36 consisting of the following is closed and housed in the mold 36. Here, inside this mold 3B, the upper, lower and outer molds 33.3
4. When 29 is closed, a cavity 37 with the same shape as the flap 16 is formed.Next, when high temperature and high pressure rubber is injected into the cavity 37 of the preheated mold 36, this rubber When it is extruded into the cavity 37, it undergoes adiabatic expansion, its temperature rises, and becomes vulcanized rubber. When the cavity 37 is filled with rubber in this manner, the periphery of the reinforcing plate 22 is covered with vulcanized rubber, and the reinforcing plate 22 and the flap 16 are integrated. As a result, the flap 16 with the reinforcing plate 22 embedded therein
is manufactured by injection molding.

Here, since the rubber sheet 31 is attached to at least one surface, that is, the inner peripheral surface, of the reinforcing plate 22 as described above, the rubber injected into the cavity 37 is attached to the reinforcing plate 22.
Even if the rubber sheet 31 is pressed, the reinforcing plate 22
This prevents the reinforcing plate 22 from moving to the upper and lower molds 33 and 34, and as a result, the reinforcing plate 22 is reliably buried inside the flap 1G and is not exposed to the outside. The flap 1B is interposed between the tube 8 and the rim l. At this time, the valve lO of the tube 8 is inserted into the hole 20 of the flap 1B and the through hole 26 of the reinforcing plate 22.
penetrate.

For this reason, the flap 18 in the vicinity of the valve IO is strongly reinforced by the reinforcing plate 22, and a situation in which the flap 1B in this area is W (supported) from the valve hole 11 of the rim 1 is prevented. Moreover, the reinforcing plate 2
2 is buried within the flap 16, so it will not come off from the flap 16 even after long hours of travel, and has excellent durability.

In the above-mentioned embodiment, the reinforcing plate 22 was constructed from a flat metal plate, but in the present invention, reinforcing ribs 4 are provided on the outer circumferential side of the reinforcing plate 22, as shown in FIG.
In this way, the valve hole 1 may be formed.
The rigidity of the flap 16 located near the flap 1 can be further increased. In this case, the rib 41 is partially exposed on the surface of the flap 16, but since the exposed portion of the rib 41 has a circular curved surface, it will not have any adverse effect on the tube 8. In the embodiment described above, the reinforcing plate 22 is approximately rectangular, but in the present invention it may be circular. If this is done, there will be no problem even if the reinforcing plate is rotated by the rubber injected into the cavity 37. Further, in the above embodiment, the flap 1B was molded by injection molding, but in the present invention, it may be molded by transfer molding or compression molding.

As explained above, according to the present invention, it is possible to easily and quickly manufacture a flap whose performance does not deteriorate even after long-term use.

[Brief explanation of the drawing]

Fig. 1 is a meridian sectional view showing an embodiment of the present invention as it is mounted on a tire, Fig. 2 is an enlarged meridian sectional view of the flap, Fig. 3 is a plan view of the reinforcing plate, and Fig. 4 is a manufactured flap. FIG. 5 is a cross-sectional view of the vicinity of the mold showing an intermediate step in manufacturing the flap; FIG. 6 is a meridian cross-sectional view of the flap showing another embodiment of the present invention. It is. 1...Rim 2...Tire end...Tube 10...Valve 11...Valve hole
18...Flap 20...Hole 2
2...Reinforcement plate 26...Through hole Patent applicant Brideston Co., Ltd. Agent Patent attorney Tadashi 1) Toshio Figure 1 Trim 8...Tube 10...Valve 16...Flare, knob 20...Hole 22 ... Reinforcement plate 26 / Through hole Fig. 2, Fig. 3, Fig. 4] 31 ・Gomu-1・ Fig. 6

Claims (2)

[Claims] (1) An annular tire flap that is interposed between the tube and rim of a pneumatic tire and has a hole through which a valve passes through at one location on the circumference, and has a through hole in the center that communicates with the hole. 1. A flap for a tire, characterized in that a highly rigid reinforcing plate in which a hole is formed is embedded within the flap near the hole. (2) pasting a rubber sheet on at least one surface of the reinforcing plate, then storing this reinforcing plate in a mold having a cavity with the same shape as the flap;
A method for manufacturing a tire flap, wherein the flap according to claim 1 is manufactured by injecting rubber into the cavity.