JPS60143109A - Tyre - Google Patents

Abstract

PURPOSE:To enhance draining performance and wear resistance by providing cuts, which incline with respect to the equator of a tyre and moreover intersect with each other, on the entire width of a tread surface after a raw cover tyre is formed and when it is valcanized or after completion of valoanization. CONSTITUTION:After a raw cover tyre 1 is formed and vulcanized, cuts 9 and 10 are made with a knife having relatively thin blade of about 3mm. or thinner in such a manner that they traverse the projected portion between grooves 4 and 4 in a tread part 2. These cuts 9 and 10 are formed on all over the width of the tyre 1 so that they incline with respect to the equator C of the tyre 1 and at the same time intersect with each other. With this contrivance, the cuts 9 and 10 having substantially zero mm. in width can be formed, thereby getting rid of directional inhomogeneity and enhancing draining performance without deteriorating wear resistance.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention improves drainage performance and durability by providing a plurality of cuts that intersect with each other over almost the entire length of the l.red surface during or after vulcanization. Regarding Uru tires.

Generally, in order to improve the braking force and turning performance of a tire on a wet road surface, it is necessary to effectively eliminate water interposed between the tread surface and the road surface. Therefore, a rib type or lug type tread pattern is mainly adopted as a tread pattern, and the zigzag-shaped main groove extending in the circumferential direction has a large groove width and groove depth, and wide lateral grooves extend from the main groove to the tread end. By providing this, drainage performance is improved.

On the other hand, in such tires, especially steel radial tires for heavy vehicles, due to the heavy load and ground pressure distribution of the tread, so-called railway wear occurs along the convex portions on both edges sandwiching the main groove. Wear, blur in running direction
There are problems such as so-called heel-to-heel wear in which uneven wear occurs at the rear end of the tread, or so-called shoulder-drop wear in which a portion of the I/red sill der wears more progressively than the center of the tread. For example, for railway wear, narrow horizontal grooves are installed at regular intervals along both edges of the main groove.
In addition, shoulder drop wear can be reduced by providing a large number of thin lateral grooves on both ends of the l and red, but conventionally, such lateral grooves are Since the plate is protruded and formed at the same time as vulcanization, there is a limit to how small the groove can be from the perspective of preventing deformation of the blade. Rather, there was a problem that it caused the water to dry low or had a negative effect on the drainage performance.

The purpose of the present invention is to provide a tie-1 that can solve such problems, and the present invention aims to provide a tie-1 that can solve the above problems. The tire is characterized by having a plurality of incisions that are diagonal to the equator of the tire and intersect with each other.

An embodiment of the present invention will be described below with reference to the drawings.

First, to describe an example of the tire of the present invention, in FIG.
1.1 is provided with a zigzag-shaped main groove 4 continuous in the circumferential direction on the tread surface 3 at the center and both sides, and the trend section 2 is connected to the trend center section 5 and a pair of left and right tread shoulders. A carcass 7 consisting of cords arranged at an angle of 80° to 90° with respect to the equator C of the tire, and a steel cord on which the tread portion 2 is arranged. On the other hand, a large number of notches 9 and 10 are provided in the circumferential direction across the trend portion 2, which are inclined with respect to the equator C of the tire.

Here, the notches 9 and 10 are inclined in opposite directions and are formed to intersect with each other. The tire 1 is preferably formed by molding and vulcanizing a green cover tire, and then
It is manufactured by forming said incisions 9.10. The raw cover tire has a 1-roid shape in which a carcass 7, a bell 1-waste 8, a bead part (not shown) and a 1-red part 2 are combined on a molding drum, and this is molded by a conventional method. After vulcanization, a cut 9.10 is cut into the original tie-1 taken out from the mold using a knife. Here, the notch 9.10 is a ridge between the main grooves 4.4 of the tread portion 2, which is carved with a sharp and relatively thin knife, bit, grindstone, or saw blade with a thickness of about 3M or less. It is a transverse cut, can be formed without substantially having a groove, and is provided obliquely to the equator C of the tire over the entire width of the tire 1 as described above. The lateral grooves of conventional tires, which are formed at the same time as vulcanization in a mold equipped with blades, have a relatively wide groove diameter which cannot be achieved in principle with a small IR. In tire 1, the width of the groove 9.10 of the notch 9.10 can be made so small that it can be virtually ignored, so the compressive stress acting within the contact patch causes the edges of the notch 9.10 to overlap each other. The rubber layer functions as if it were a continuous, integrated rubber layer, which improves rigidity and prevents deterioration of wear resistance. In addition, since the cuts 9 and 10 are formed so as to be inclined in opposite directions, the directionality is eliminated compared to when the cuts in the tread surface are formed only in one direction, and uneven wear can be reduced. When used for the front wheels, straight-line performance can also be improved. In addition, for bending stress generated near the grounding edge,
The cuts 9 and 10 allow the tire to be flexibly deformed, effectively dispersing and alleviating stress, and preventing shoulder drop wear of the tread portion 2, as well as improving the spring-off and depression during running, that is, the grip. Ru. Furthermore, both edges of the notches 9 and 10 that are opened during bending deformation cut the water film and improve drainage in the direction of the main groove 4. In order to enhance this effect, the cuts 9 and 10 are substantially straight over the entire 11 of the tread portion 2, and at an angle of 30° to 90°, preferably in the range of 50° to 80", with respect to the equator C of the tire. It is better to set the cut 9.10 so that it is inclined.If the extension angle of the cut 9.10 is too small, the effect of preventing uneven wear will be reduced and the effect of improving wet grip properties will be small. The depth d is 50 to 110 of the groove depth D of the main groove 4.
%, and the spacing between the cuts 9 is in the range of 5 to 50 degrees, preferably 10 to 3 Qva. Cut 9
．． If an excessively large number of holes 10 are provided, the rigidity of the I-Red 2 will be lowered and the handling stability and wear resistance will be impaired. Note that the notches 9 can be arranged at irregular intervals in addition to regular intervals in the circumferential direction, and can also be formed so as to periodically repeat several kinds of intervals. Furthermore, several types of cuts with different groove depths d may be mixed. In addition, cut 9.
10 is usually performed by machining from the viewpoint of productivity and processing accuracy, and furthermore, by using an automatic cutting machine that can adjust the cutting position and angle.

In this way, the tire of the present invention has a plurality of incisions that are inclined in opposite directions during or after vulcanization of the tire, so that the directionality of the tread surface due to the incisions can be eliminated and the groove width can be substantially reduced. Since it is formed to have a narrow width without having any cracks, grip properties, abrasion resistance, drainage properties, etc. are improved. .

The tire of the present invention can be used for various tire types such as passenger car tires and heavy vehicle tires, such as lug type, lug type, and soft type, but in particular, the tire has two zigzag-shaped main grooves continuous in the circumferential direction on the trend surface. It is suitable for use in steel radial tires for 1-rank buses, which are equipped with ~5 tires.

Actual JU properties The 1000R20 steel radial tires shown in Figures 1 and 2 were cut according to the specifications shown in Table 1, and the characteristics such as abrasion resistance and wet grip were evaluated.Table 1 shows the results. It is clear that the tire manufactured by the tire manufacturing method of the present invention has improved mechanical characteristics.

Note 1) As shown in Figure 1. Note 2) Measured with a trailer tester under g and n conditions on JARI's comprehensive test track, and is shown as a relative value to the comparative example. The larger the value, the better.

Note 3) The distance traveled until L-Red wears 1 mm in actual vehicle driving tests is shown as a relative value.

Note 4) Measured using a transfer resistance tester.

[Brief explanation of drawings]

FIG. 1 is a partial plan view illustrating the tire of the present invention, and FIG. 2 is a sectional view taken along the line AA. 1-tire, 2-) red part, 3--tread surface, 4-main groove, 9.10-notch, c-tire equatorial patent applicant
Jumingo J, Industrial Co., Ltd. Attorney ± 6゛1 Tadashi Mura

Claims (1)

[Scope of Claims] +11 After forming a green cover tire and vulcanizing it or after vulcanizing it, the Tie 4 of the trend surface of the tire is inclined to the equator and intersects each other. A tire characterized by having a plurality of notches. (2) The tire according to claim 1, wherein the cuts are substantially linear and are provided at equal intervals in the circumferential direction of the tire. (3) The cut is 30° to the equator of the tire.
A tire according to claim 1, characterized in that it is inclined at an angle of 90'. (4) The tire according to claim 1, wherein the incisions are provided at intervals of 5 to 50 mm in the circumferential direction of the tire. (5) The tire according to claim 1, wherein the tread surface of the tire has two to five zigzag-shaped main grooves continuous in the circumferential direction. (6) The tire according to claim 1, wherein the tire is a steel radial tire for an L-rack or bus.