JPS6076405A - Spike pin for tyre - Google Patents

Abstract

PURPOSE:To prevent damage to the road surface by forming a part of a tyre, which touches the road surface, by using resin whose taper wear and rockwell hardness are as predetermined. CONSTITUTION:At least the part of a tyre, which touches the ground surface, is fabricated by using resin, whose taper wear for CS-17, 1,000g does not exceed 10mg/1,000 times and moreover whose rockwell hardness in R-scale, by ASTM 785 is 35 or higher, for example, polyethylene of super-high molecular weight, whose mean molecular weight is one million or more, nylon 66, polyacetal, or the like. With this constitution, both remarkable wear of a spike pin and decrease in spike effect can be restricted and damage to the road surface can be prevented.

Description

[Detailed Description of the Invention] Technical field to which the invention relates The present invention relates to snow tires for tires, and more specifically, by making at least the portion that contacts the road surface of resin, almost no road surface damage occurs. This invention relates to a tire spike bin.

BACKGROUND OF THE INVENTION Conventional tires have significantly reduced dynamic characteristics on winter roads, especially on frozen roads. This is because the coefficient of friction (μ) between the rubber surface of the tire and the ice is extremely small. In order to improve this problem, spike bins for tires have been developed, and spiked tires to which these spike bins are applied have come to be used frequently, especially in snowy and cold regions.

This spike bin utilizes the so-called spike effect, which involves scratching the ice surface with a hard metal and using the resulting resistance to create a high overall frictional force. These spike bins are not effective unless they have better abrasion resistance than tire rubber, and if they are not hard, they cannot produce a sufficient spike effect, so cemented carbide such as tungsten carbide or cobalt carbide is generally used. It has been. Spiked tires made of such spike bottles can be driven safely even on frozen roads in winter, and are extremely effective in ensuring safety and convenience.

However, at the same time, several major problems have arisen, one of which is the problem of damage to the road surface caused by the cemented carbide of the spikes. Damage increases the risk of accidents, necessitating huge road repair costs and road sign repair costs. Another problem is noise. In particular, the former type of road damage is a major problem, and improving this problem is an urgent task for tire manufacturers and spike manufacturers.

However, concrete countermeasures that have been proposed so far include making the flanges of spike bottles smaller and reducing the overall weight.
The spike effect itself was still produced by the cemented carbide. Therefore, although the degree of road surface damage and resulting dust pollution may be improved to some extent, it cannot be said to be an essential solution.

On the other hand, regarding the spike effect, it was conventionally thought that hardness = spike effect, and 1+wear resistance = hardness.

Under such circumstances, the inventors of the present invention have conducted extensive research to improve the spike bin, and have found that it is acceptable if the Rockwell hardness (R scale: ASTM 786) is 85 or higher, and if it protrudes even slightly from the tire surface. , found that spike bins exhibit sufficient spiking effects. In other words, we confirmed that it is possible to make spike bins with sufficient performance without using cemented carbide if the material is extremely hard and has excellent abrasion resistance, and is also resistant to road surface damage. We also found that there was a positive correlation. Based on this knowledge, the present inventors are fully convinced that by using a resin that is much softer than cemented carbide in terms of hardness and improving its wear resistance, it will be possible to create a spike bin that will cause almost no damage to the road surface. The result of research is F! A'f! Achieved:

DISCLOSURE OF THE INVENTION Accordingly, the present invention provides at least the portion that contacts the road surface with tapered wear (O8-17,100Or) of 1O27100.
0 times or less and Rockwell hardness (R scale: AS
The present invention relates to a tire spike bin characterized in that it is made of a resin having a TM785) of 85 or more.

Taper wear of the resin used in the spike bottle of the present invention (
The reason why O3-17,1000f) is limited to 10■/1000 times or less is that if it exceeds this value, the tire's (B
) This is because during normal driving, the spike bin also wears out to a large extent, and the surface of the spike bin becomes as high as, or even lower than, the tire surface, making it impossible to obtain any spike effect.

The Rockwell hardness (R scale: AS
The reason why TM 785 ) is limited to 85 or more is because a spike effect cannot be obtained if it is less than 85.

In this way, taper wear (O8-17, 1000r)
is less than 10 71000 times and Rockwell hardness (R
Resins whose scale: ASTM 785) is 8Fi or more include, for example, ultra-high molecular weight polyethylene with an average molecular weight of 100 million or more, nylon 66, polyacetal, MO
There are nylon, fluororesin, polyurethane, polyester resin, etc.

In the present invention, when the tire temperature is 7.
In order to prevent creep at such temperatures, it is particularly preferable that the resin has a Vicat softening point of 120°C or higher.

Next, in the spike bottle of the present invention, at least (4) the part that contacts the road surface may be made of the above-mentioned resin, but considering the wear of the resin, etc., the spike bottle should be 5 mm from the tip that contacts the road surface.
It is preferable that the above-mentioned parts are made of resin, and from the viewpoint of manufacturing, it is more preferable that the entire part be made of resin because the manufacturing process is simple.

Examples of the invention The invention will be illustrated by the following examples and comparative examples.

Example 1. Comparative Example 1.2 The spike bottle 1 shown in FIG. 1 was manufactured under the following conditions.

Mold temperature: 220°C Pressing time: 40 minutes Material: Ultra-high molecular weight polyethylene Hizex Million 840M (Mitsui Petrochemical Industries, Ltd., trade name) Powder of Hizex Mirio/840M is placed in a mold heated to 2120°C, and pressed at 50 kp/m. After 40 minutes, the mixture was cooled for 80 minutes using a press machine at room temperature under 10Okf/30 conditions to obtain a spike bottle. 1) Taper wear of ethylene is 0
, 6η/1000 times, the Hikat softening point was 184°C, and the Rockwell hardness was 40 (R scale).

Then, 12 spikes were inserted into each radial snow tire of tire size 176SR14 for 1 s to produce a tire of Example 1.

For comparison, the tip 2 having the dimensions shown in Fig. 2 was made of cemented carbide made of tungsten carbide (Ikubin (manufactured by Toshiba Tungaloy Corporation) 1), and the tire size was 1758.
R14 radial snow tire with 1 tire J I4
A tire of Comparative Example 1 was made by driving two tires.

For these tires and similar tires that do not have snowboard pins driven in, the braking distance on dry asphalt, the braking distance on ice, and the degree of road damage were all evaluated.The values of Comparative Example 1 were
00 and expressed as an index.

The braking distance on dry asphalt and ice is measured at 40 mph with each tire mounted on a 2000 cc passenger car.
km/hr"'C When driving, sudden braking was applied and the distance from the point where the brake was applied to a complete stop was evaluated, and Q was calculated using the following formula: Using a tire test drum with a
0 km/hr Tire internal pressure 1.7'q/cm2 Load According to JIS 100 coefficient load, the drum was run for 8 hours, evaluated at the deepest point of the ring, and calculated using the following formula; (7) From Table 1 above, it is clear that the spike bin of the present invention provides almost the same traction on icy roads as the cemented carbide spike bin, and hardly damages the road surface on normal road surfaces.

In Figure 1, / = 18. Otnm, l,=
8. Orvand (diameter) - 1Qmti, d, (diameter) = 71111rrL, R = 0.5 mrm.

In Figure 2 / = 12. '1mm, l! ,=
IJmtn.

! ! a "11,?t'nme l4"
8 t'n'In l dl (diameter) = 10 mm
.

d (diameter) = 6.6rnm, d8 (diameter) = 2,
5 mm.

d (diameter) = 2.1rnrn, Rx = '0.6'nL
mo.

Examples 2-6. Comparative Examples 8 to 5 Spike bottles of Examples 8 to 6 and Comparative Examples B to 6 (8) having the shapes shown in FIG. 1 were made in the same manner as in Example 1 using the resins shown in Table 8. These spike bottles were similarly driven into tires similar to those in Example 1, and their performance was evaluated. The obtained results are also listed in Table 2. In the actual vehicle wear test in the table, the vehicle was driven for 10,000 km, the spike bottle was taken out, and the wear volume was calculated from the wear weight before the run using the following formula.

Regarding creep, the larger the deformation of the spike bin, the smaller the spike effect.

Dry asphalt surface braking distance and ice braking distance are Comparative Example 1
It is expressed as an index with the case of 100 as 100.

From the results in Table 2, the taper wear of the resin is 10■/100
It is clear that it is necessary that the hardness is 0 times or less and the Rockwell hardness is 85 or more, and it is preferable that the reed and Vicat softening points are 120° C. or more.

Effects of the Invention As described above, the tire spike bin of the present invention has at least the portion that contacts the road surface made of resin, and the taper wear (O8-17, 100Of) of this resin is 10"f/
By using a Rockwell hard 111 (R scale: Ai9TM 785) of 85 or higher and less than 1,000 times, the spike pin hardly damages the pressure surface under normal pressure conditions, compared to spike pins made of cemented carbide.
A spiked tire with these spikes provides almost the same traction as a tire with cemented carbide spike pins, and eliminates all the traction caused by conventional spike pins.

[Brief explanation of the drawing]

FIG. 1 is a side view of a tire spike bin as an example of the present invention, and FIG. 2 is a partially cutaway side view of a conventional spike pin. 1... Spike pin 2... Chip.

Claims (1)

[Claims] L At least the part that comes into contact with the road surface has a wear (O8-17,100Of) of 10 71,000 times or less and a Rockwell hardness [(R scale: ASTM 7
86) is made of resin with a grade of 85 or higher.