JPH05169910A - Flap for tire - Google Patents

Abstract

PURPOSE:To restrain the occurrence of puncture of a tube, and also to enhance the work efficiency in the replacing work of the tube by facilitating the relative displacement between the tube and a flap in accordance with the deflection of a tire. CONSTITUTION:In the assemblage both of a pneumatic tire 4 in which a tube 3 has been housed and of a rim 6, wing parts 10 that have been filled between the tube 3 and the bead part 5 of the tire and also that rise while being in contact with the inside surface of the bead part 5 are provided on both sides of the base part 9 being in contact with the rim, and also a plurality of grooves 12 extending in the circumferential direction of the tire are provided to the outer circumferential surface 11 of the base part being in contact with the tube 3. The ratio of the sum SIGMAYi of the groove lengths along the outer circumferential surface in the section including the axis of the tire to the length X of the outer circumferential surface along the outer circumferential surface, or the groove length ratio SIGMAYi/X is made to be 0.15 to 0.4 and the groove depth of each groove 12 is made to be 0.8 mm to 2.5 mm, so that the adhesion between the tube and the flap can be prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flap for a tire, which facilitates the movement between the tube and the flap depending on the bending of the tire during traveling and suppresses the occurrence of puncture.

[0002]

2. Description of the Related Art In a tire such as a tire for a light truck or a tire for a truck or a bus, which uses a tube to hold internal pressure air, a tube a and a rim r are generally provided as shown in FIG. By interposing an annular flap f made of a rubber composition between them, it is widely possible to prevent friction with the tube a at the rim r due to vibration during traveling or bending of the tire or damage to the tube a due to the bead portion b. It is being appreciated.

[0003]

However, the tube a and the flap f are formed by applying internal pressure to the tube.
When the tires are in contact with each other under a strong pressure and the vehicle continues to run in this state, the tires are repeatedly deformed to cause a relative displacement, resulting in adhesion between the tube a and the flap f. The problem arises. Further, this sticking phenomenon tends to cause the tube b to be deformed and the tube b to be broken in the blade portions fw and fw sandwiched between the tire b of the flap f and the tube a.

In order to solve one of the above problems, the outer peripheral surface e of the flap f facing the tube b is finished to be smooth, and a release agent is attached to the contact surface in order to prevent adhesion with the tube b during assembly. The method of applying is done,
The work efficiency is lowered by the application of the release agent, and the work environment is deteriorated by the release agent being scattered when the tube is replaced. Moreover, the adhesion of the flap wing fw to the tube b is not completely solved by the application of the release agent, and there is still the risk of the tube b being punctured.

The inventors have found that by providing a plurality of grooves extending in the tire circumferential direction on the outer peripheral surface facing the tube of the flap, it is possible to prevent the flap from sticking to the tube when the tire is running. Was completed.

It is an object of the present invention to provide a flap for a tire which can eliminate the risk of puncture by preventing the tube from sticking to the tube and preventing the tube from being damaged.

[0007]

According to the present invention, a pneumatic tire in which a tube is loaded in a tire inner cavity, and a pair of bead portions arranged radially inside a sidewall portion of the pneumatic tire are attached. A flap for a tire that is loaded between a tire consisting of a rim and the tube of an assembly of the rim and that orbits the rim in an annular manner, the flap being provided on both sides of a base portion contacting the rim, and a bead of the tire. The outer peripheral surface in contact with the tube is provided with a plurality of linear grooves extending in the tire circumferential direction, and the length of the linear groove along the outer peripheral surface in a cross section including the tire shaft. Of the groove length ratio ΣYi / X, which is a ratio of the sum ΣYi of the heights Yi to the length X of the outer peripheral surface along the outer peripheral surface in the cross section including the tire axis, is 0.15 or more and 0.4 or less. Groove depth 0.8 A flap for a tire, characterized in that it is not less than mm and not more than 2.5 mm.

The circumferential groove may have an endless shape in the circumferential direction, and may have a discontinuity at one location or at a plurality of locations.

[0009]

Function: A plurality of grooves extending in the tire circumferential direction are provided on the outer peripheral surface in contact with the tube. As a result, the tube and the outer peripheral surface of the flap are disconnected from each other in the groove portion. As a result, the contact area where the tube and the outer peripheral surface of the flap contact each other is reduced, and since the decrease in the contact area is dispersed over the entire outer peripheral surface of the flap, the adhesion between the both is relaxed over the entire outer peripheral surface. be able to.

Further, when a temperature difference occurs in the tire assembled on the rim, the pressure difference between the air in the tube and the air interposed in the groove fluctuates, and this fluctuation causes a slight fluctuation in the tube. As a result of the movement, it is possible to further prevent the both from sticking.

Further, in a cross section including the tire shaft, a groove length ratio ΣYi / which is a ratio of the sum ΣYi of the lengths Yi of the line grooves along the outer peripheral surface of the flap and the length X of the outer peripheral surface in the cross section.
X is set to 0.15 to 0.4. If the ratio is less than 0.15, the adhesion between the flap and the tube is large, and the puncture rate of the tube is large. If the ratio exceeds 0.4, the contact area between the tube and the flap is reduced, resulting in the internal pressure of the tube. As a result, the contact pressure per unit area becomes large, resulting in an increase in the adhesive force and a decrease in the efficiency of tube exchange work after traveling.

The groove depth of each groove is in the range of 0.8 to 0.25 mm. If the groove depth is less than 0.8 mm, the inner surface of the tube will be loaded into the groove and the outer surface of the tube will come into strong contact with the groove bottom of the groove, preventing relative movement between the two and making the tube puncture easily. Also, the workability of the replacement work is poor. On the other hand, if it exceeds 0.25 mm, the thickness of the flap groove bottom, especially the blade, becomes small, and damage is likely to occur.

As described above, according to the present invention, the above-mentioned components are organically combined and integrated to prevent the flap and the tube from sticking to each other when the tire is running, so that the tube and the flap can be moved in accordance with the bending of the tire. This makes it easier to prevent puncture of the tube, enhances durability, and improves workability when replacing the tube and the tire.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. 1 to 3, a flap 1 for a tire includes a pneumatic tire 4 having a tube 3 loaded in a tire lumen 2,
A rim 6 to which the bead portion 5 of the pneumatic tire 4 is attached
It is mounted between the tube 3 and the rim 6 of the tire and rim assembly 7 consisting of.

The pneumatic tire 4 is composed of sidewall portions 23, 23 extending inward in the radial direction from both ends of the tread portion 22, and the bead portions 5, 5 radially inward of the sidewall portions 23, 23. There is a tire base 25 having the tire bore 2 surrounded by these members, and the tire bore 2 is loaded with a tube 3.

Further, in this embodiment, two bead cores 26, 26 arranged in the tire axial direction are arranged in the bead portion 5, and each of the bead cores 26, 26 passes from the tread portion 22 to the side wall portion 23 and becomes a bead portion. The carcass ply 27a extending to 5 is rewound and the carcass 27 is formed by the carcass ply 27a.

The tube 3 is a hollow torus made of a relatively soft rubber, and a valve (not shown) is provided so as to project on the radially inward surface.

The rim 6 includes a pair of bead seat portions 30, on which bead bottom surfaces 29 of the bead portions 5, 5 are seated.
It is formed by connecting between 30 by the cylindrical ring piece 31.

The flap 1 for a tire is made of a vulcanized rubber base material, and includes a base portion 9 whose radially inward surface is in contact with the rim 6 and a bead portion 5 of the pneumatic tire 4 as shown in FIG. A pair of wings 1 standing up in contact with the inner surface 5A
It has 0 and 10. Further, the flap 1 for a tire is provided with a plurality of grooves 12 extending in the circumferential direction over substantially the entire outer peripheral surface 11 in contact with the tube 3.

It is preferable that the grooves 12 are provided in a range of 8 to 15 symmetrically with respect to the tire axial direction about the tire equator CO. In this embodiment, three grooves are formed in the base portion 9 and each blade portion 10 on both sides. There are 3 grooves in each of 10 and a total of 9 groove grooves 12 ...
Is provided. In the present embodiment, each groove 12 is formed as a circumferential groove that is continuous in the circumferential direction.

The flap 1 for a tire has a groove 12 extending along the outer peripheral surface 11 in a cross section including the tire shaft.
The total sum ΣYi of the respective lengths Y1, Y2, Y3 ... Y9 and the outer peripheral surface length X along the outer peripheral surface 11 in the cross section including the tire axis.
The groove length ratio ΣYi / X, which is the ratio to the above, is 0.15 or more and 0.4 or less. The groove depth H of each groove 12 is 0.8 mm or more and 2.5 mm or less.

In this embodiment, in the wing portion 10, the groove lengths 12B of the wing portion arranged on the wing portion 10 are longer than the groove lengths 12A of the base portion arranged on the base portion 9. Sa 1.1
It is 1.2 times larger. In this way, the wing 10 has the base 9
Compared with the above, the relative movement with the tube 3 is facilitated, the close contact with the tube 3 that tends to occur in the blade portion 10 can be more effectively prevented, and the damage of the tube 3 can be further prevented.

The groove 12 has a groove length ratio ΣYi.
In the range of / X, the groove 12 may be formed as an interrupted groove having a single or a plurality of interrupted portions.

[0024]

SPECIFIC EXAMPLE A tire having a tire size of 10.00R20 and a tube and flaps mounted on a 7.00T rim was subjected to a running test, and the state after running was investigated.

In the test, the groove length ratio was changed stepwise from 0 to 1.0, and the assembling was performed without applying a release agent for preventing adhesion.

The test was conducted as follows. B) Peeling between tube and flap Attached to a real vehicle, after traveling 100,000 km, disassembled tube
The difficulty of peeling between the flaps was judged by the operator's feeling, and the index without a groove was indicated as 100. The larger the value, the better.

(B) Puncture rate Flap samples having different groove length ratios are manufactured stepwise,
A trial use was requested for the field test, and the puncture occurrence rate was displayed as a percentage for each of 100 samples. The smaller the number, the better.

The peelability is shown in FIG. 3, and the puncture rate is shown in FIG. 4, respectively.

As a result of the test, the groove length ratio ΣYi / X was set to 0.
It was confirmed that the peelability and the puncture rate can both be improved by setting the range to 15 to 0.4.

[0030]

As described above, in the flap for a tire of the present invention, a plurality of grooves are provided on the outer peripheral surface in contact with the tube, and the total length of the grooves and the groove depth are within a predetermined range. Since it is regulated in the tube, it prevents adhesion between the tube and the flap caused by running, facilitates relative movement between the tube and the flap according to the bending of the tire during running, and can suppress the occurrence of puncture of the tube, and The work efficiency in the replacement work can be improved.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

FIG. 2 is an enlarged end view showing the flap.

FIG. 3 is a graph showing the relationship between the groove length ratio and the peelability between the tube and the flap.

FIG. 4 is a graph showing a relationship between a groove length ratio and a puncture rate.

FIG. 5 is a cross-sectional view showing a conventional technique.

[Explanation of symbols]

 2 lumen 3 tube 4 pneumatic tire 5 bead 5A inner surface 6 rim 7 tire-rim assembly 9 base 10 wing 11 outer peripheral surface 12, 12A, 12B groove CO tire equator H groove depth Y groove length X Outer peripheral length

Claims (3)

[Claims] 1. A tire comprising a pneumatic tire having a tube inside a tire bore and a rim to which a pair of beads arranged radially inward of a sidewall of the pneumatic tire are attached. A flap for a tire that is mounted between the tube of the assembly of FIG. 1 and orbits around a rim in an annular shape, and the flap is a wing that rises on both sides of a base portion that contacts the rim and that contacts the inner surface of the bead portion of the tire. A plurality of grooves extending in the tire circumferential direction on the outer peripheral surface in contact with the tube, and the sum Σ of the lengths Yi of the grooves along the outer peripheral surface in a cross section including the tire shaft.
The groove length ratio ΣYi / X, which is the ratio of Yi to the length X of the outer peripheral surface along the outer peripheral surface in the cross section including the tire axis, is 0.15.
A flap for a tire, characterized in that it is not less than 0.4 and not more than 0.4, and the groove depth of each groove is not less than 0.8 mm and not more than 2.5 mm. 2. The flap for a tire according to claim 1, wherein the outer peripheral surface includes 8 to 15 groove grooves symmetrically with respect to the tire equator in the tire axial direction. 3. The wing has a groove length of 1.1 to the base.
The flap for a tire according to claim 1, wherein the flap is 1.2 times larger.