JPH06340203A - Pneumatic solid tire - Google Patents

Abstract

PURPOSE:To prevent rim chafing so as to improve durability by disposing clincher rubber made of hard rubber and a canvas chafer at the contact part of a base rubber layer with a rim flange, and setting the thickness of the base rubber layer to a specific dimensional rate to the cross-sectional height of a tire. CONSTITUTION:A base rubber layer 2 on the radially innermost side of a tire 1 is formed of hard rubber reinforced by short fiber cords or hard rubber made of only rubber. At the time of mixing short fiber cords into rubber, in order to prevent the lowering of a radiating effect, the thickness TB of the base rubber layer 2 is made 30-60% of the tire cross-sectional height TH. Further in order to prevent the wear of rubber at the contact part of the base rubber layer 2 with a rim flange RF, clincher rubber 6 formed of strip rubber is stuck to the tire axial outer side of the base rubber layer 2, and one or two canvas chafers 7 formed by rubberizing organic fiber such as nylon fiber or inorganic fiber such as steel are stuck to the axial inner side of the clincher rubber 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pneumatic solid tire which prevents rim chafing of the tire.

[0002]

2. Description of the Related Art Solid tires, particularly pneumatic solid tires, are required to have improved durability by increasing the speed of industrial vehicles and increasing horsepower. In particular, rim chafing occurs in which the rubber on the bead side surface, that is, the clincher portion is worn away due to repeated local deformation in which the rim flange bites into the bead side surface of the tire due to lateral deformation during turning during high speed running.

On the other hand, as shown in FIG. 2, a pneumatic solid tire has a base rubber layer a made of hard rubber reinforced with short fibers and a JIS A hardness of 60 to 70 (HS).
There is known a two-layer structure having a cap rubber layer b made of a softer rubber than the base rubber layer a.

However, in such a tire, the base rubber layer a is inferior in heat dissipation, the temperature of the tire increases due to heat generation of the tire due to repeated bending strain due to rotation of the tire, and the rim chafing due to the local deformation is further promoted. At the same time, there is a problem that rim slip occurs due to a decrease in fitting pressure.

Further, as shown in FIG. 3, the base rubber layer a
Between a cap rubber layer b made of hard rubber and a band layer B formed by winding a fiber cord in the circumferential direction and having a cap rubber layer b made of hard rubber.
A three-layer structure in which an intermediate rubber layer c made of soft rubber or foam having an ISA hardness of 40 to 58 is arranged has been proposed. However, this specification has a large vertical deflection and is expected to improve riding comfort. The effect of preventing rim chafing is not sufficient.

An object of the present invention is to provide a pneumatic solid tire capable of preventing rim chafing and improving durability.

[0007]

The present invention comprises a base rubber layer located on the innermost side in the radial direction of a tire and a cap rubber layer located on the ground contact surface side and having a JIS A hardness of 50 to 70 (HS). A clincher rubber made of hard rubber is provided in a portion of the base rubber layer that comes into contact with the rim flange,
One or more canvas chafers made of organic or inorganic fiber cloth, which are located on the inner side in the axial direction and extend in the radial direction, are arranged, and the thickness TB of the base rubber layer is set to 30 to 60 of the tire cross-section height TH. It is a pneumatic solid tire with a range of%.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. In FIG. 1, a pneumatic solid tire (hereinafter referred to as a tire) 1 of the present invention includes a base rubber layer 2 located on the innermost side in the tire radial direction and a cap rubber layer 3 located on the ground contact surface side. In the example, a three-layer structure is formed in which the intermediate rubber layer 4 is located in the middle of the cap rubber layer 3 and the base rubber layer 2.

The tire 1 also has a cross-sectional shape close to that of a pneumatic tire mounted on the rim R, and the outer surface of the tire 1 extends from both sides of the tread surface 10 to a sidewall surface 11 and a bead side surface 12 fitted to the rim 12. It is connected to the bead bottom surface 13.

The base rubber layer 2 is a hard rubber reinforced with short fiber cords or a hard rubber consisting only of rubber. When short fiber cords are used, organic fiber cords such as polyester, nylon and rayon can be used. Preferably, a piece cut to a length of 10 mm or less is used.

Further, a case material used for a pneumatic tire or a case material recovered from a waste tire may be cut with a crusher mill or the like.

By using the rubber composition containing these short fiber cords in the base rubber layer 2, its rigidity is improved, the fitting pressure of the rim of the tire is increased, and slippage between the two can be prevented.

However, in the rubber composition containing the short fiber cord, when the short fiber cord is mixed into the rubber, air is also taken into the inside of the rubber, and as a result, the heat conduction and hence the heat radiation effect is reduced as described above. Base rubber layer 2 thickness T
B is 30 to 60% of the tire section height TH, preferably 3
The height range of 5 to 45% exceeds the height H of the rim flange RF of the rim R. If the value is less than 30%, the fitting pressure with the rim cannot be maintained, while if it exceeds 60%, the heat radiation effect is significantly reduced.

The short fiber cord is mixed in an amount of 40 parts by weight or less, preferably 15 to 25 parts by weight, based on 100 parts by weight of rubber.

In the case of the base rubber layer 2 made of a hard rubber containing no short fibers, a rubber having a high compression elastic modulus of JISA hardness 70 to 90 (HS) is used.

A rubber having a JISA hardness of 50 to 70 (HS) ° is used for the cap rubber layer 3, and a rubber composition having excellent wear resistance, crack resistance, and gripping property, such as natural rubber or isoprene rubber, is used. A so-called tread rubber compound in which a predetermined amount of carbon is compounded in a diene rubber such as styrene-butadiene rubber is used.

When the JISA hardness is less than 50 °, the wear resistance is poor, and when the JISA hardness exceeds 70 °, the grip performance is deteriorated.

Further, the thickness TC of the cap rubber layer 3 is in the range of 20 to 60%, preferably 20 to 50% of the tire cross-section height TH in the case of this embodiment using the intermediate rubber layer 4. . When the intermediate rubber layer 4 is not used, it is 40 to
70%.

The thickness TC of the cap rubber layer 3 correlates with the service life due to wear of the tire 1, and the service life can be extended by increasing the thickness, but in this example, the cap rubber layer 3 is thickened. As the thickness increases, the intermediate rubber layer 4 becomes thinner.

Next, the intermediate rubber layer 4 has a JIS A hardness of 4
A rubber having a hardness of 0 to 80 HS and harder or softer than the rubber of the cap rubber layer 3 can be appropriately used according to the purpose.

When soft rubber is used for the intermediate rubber layer 4, cushioning properties are excellent, while heat generation can be reduced by using hard rubber to suppress the amount of deformation. Even if a rubber material having a small resilience is used, the amount of deformation is small, the amount of heat generated is small, the degree of freedom in selecting the rubber material is high, and the product cost can be reduced.

Further, when a rubber having a large rubber hardness is used, the deformation under a high load is small, the load bearing capacity is improved, and the pitching property and rolling property are also decreased.
Forklift cargo handling becomes easy.

The thickness TE of the intermediate rubber layer 4 is selected within the range of 20 to 50% of the tire section height TH.

Further, in order to prevent the occurrence of cracks due to a sudden change in rigidity, the boundary surfaces of the base rubber layer 2, the cap rubber layer 3 and the intermediate rubber layer 4 have a difference in JISA hardness between adjacent rubbers of 8 ° or less. Is desirable.

Further, the rim flange RF of the base rubber layer 2
It is important to prevent abrasion of the rubber due to this rim flange RF at the contact portion with.

For this reason, the clincher rubber 6 made of strip rubber having a thickness of 3 to 5 mm is attached to the outer side of the base rubber layer 2 in the axial direction of the tire, and the inner side of the clincher rubber 6 is, for example, 84.
One or two canvas chafers 7 made of rubberized ply are attached to a cloth formed by plain weaving using organic fibers such as 0d nylon fibers and inorganic fibers such as steel.

The clincher rubber 6 is softer than the base rubber layer 2 in order to reduce slippage between the clincher rubber 6 and the rim R.
A rubber having an ISA hardness of about 55 to 75 ° is used.

The canvas chafer 7 is intended to reinforce this portion and prevent rim chafing due to the local deformation.
Also serves to maintain the fitting pressure between the flanges of the tire by breaking the base rubber layer 2 even when the clincher rubber 5 is worn out under severe conditions, prevent rim slip, and maintain durability.

Therefore, the camber chafer 7 has a height of 1.0 to 1. ． 3 times, namely 1.0
Set to H to 1.3H.

[0030]

[Examples] Tires of tire size 650-10 are shown in Table 1.
It was manufactured according to the specifications shown in, and the durability and ride comfort of the base were tested. The riding comfort was evaluated by a feeling test with Comparative Example Product 1 being 100 using an actual vehicle. Preferably 100
The above is good.

[0031]

[Table 1]

The durability of the base is shown by setting the time until a rim slip occurs when a forklift of 1.5 ton product is loaded with a specified load and a figure 8 course of 50 m per lap is made as 100 for Comparative Example product 1. ing. The tread life is
The wear volume of the tread was measured in the above test, and is shown as an index with Comparative Example 1 being 100. The test tires are mounted on the front wheels, and the conventional tires of 7.00-12 size are mounted on the rear wheels. Further, the tire has a structure mainly shown in FIG. 1, and the intermediate rubber layer is removed by the tire.

[0033]

As described above, the tire of the present invention can prevent rim chafing and improve durability.

[Brief description of drawings]

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

FIG. 2 is a cross-sectional view illustrating a conventional tire.

FIG. 3 is a cross-sectional view illustrating a conventional tire.

[Explanation of symbols]

 2 Base rubber layer 3 Cap rubber layer 4 Intermediate rubber layer 6 Clincher rubber 7 Canvas chafer TH Tire section height TB Base rubber layer thickness TC Cap rubber layer thickness TE Intermediate rubber layer thickness

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[Procedure amendment]

[Submission date] September 10, 1992

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] 0030

[Correction method] Change

[Correction content]

[0030]

SPECIFIC EXAMPLE A tire having a tire size of 6.50-10 was manufactured according to the specifications shown in Table 1, and the durability of the base portion and the riding comfort were tested. The ride quality of the comparative example product 1 is 100 depending on the actual vehicle.
Was evaluated by a feeling test. Preferably 10
0 or more is preferable.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0031

[Correction method] Change

[Correction content]

[0031]

[Table 1]

[Procedure 3]

[Document name to be amended] Statement

[Name of item to be corrected] 0032

[Correction method] Change

[Correction content]

The durability of the base is shown by setting the time until a rim slip occurs when a forklift of 1.5 ton product is loaded with a specified load and a figure 8 course of 50 m per lap is made as 100 for Comparative Example product 1. ing. The tread life is
The wear volume of the tread was measured in the above test, and is shown as an index with Comparative Example 1 being 100. Test tires are attached to the front wheels, and conventional tires of the size 5.00-8 are attached to the rear wheels. Further, the tire has a structure mainly shown in FIG. 1, and the intermediate rubber layer is removed by the tire.

Claims (2)

[Claims] 1. A base rubber layer located on the innermost side in the radial direction of a tire, and a ground surface side JISA hardness of 50 to 70.
A clincher rubber made of hard rubber is provided in a portion of the base rubber layer that is in contact with the rim flange, and an organic or inorganic fiber cloth that is located inward in the axial direction and extends in the radial direction. And one or more canvas chafers each of which has a thickness TB of the base rubber layer of 30 to 60 of a tire cross-section height TH.
Pneumatic solid tire with a range of%. 2. The canvas chafer is arranged over a range from a bead base portion to a height Hc which is 1.0 to 1.3 times the height H of the rim flange.
Pneumatic solid tire described.