FI103334B - Figure knob ring - Google Patents

Abstract

Tread comprises (i) two wide main circumferential grooves having axial grooves extending therebetween divide the tread portion into at least three rows of blocks; (ii) a series of 1st sipes, narrower than the circumferential and axial grooves, are provided in the tread surface, (iii) the depth of the axial grooves is 0.2 0.5 times the depth of the circumferential grooves, (iv) each axial groove has in its bottom face a 2nd sipe having a width of 0.2 to 1.1mm, (v) each 2nd sipe extends centrally in the axial groove, has a length between 0.7 and 1.0 times the groove length and terminates, within the groove, and the total of the depths of the axial groove and the second sipe is not more than 0.7 times the depth of the circumferential grooves. The axial grooves may be inclined at not more than 30 deg. w.r.t. the tyre axial direction. A pair of narrow zigzag circumferential grooves (3a) may be provided between the wide straight circumferential grooves (3b). The central portion of the axial grooves may comprise narrow grooves (6a) alternating with wider grooves (7a), the wider grooves (7a) having the same depth (P) as the adjacent circumferential groove (3a), and the narrow grooves (6a) being shallower than this depth (P).

Description

103334

Figure knob ring

The present invention relates to a pneumatic tire having an improved button pattern tread pattern which improves wet grip and resistance to uneven wear.

Recently, in order to prevent dust contamination, it has been started to use studless tires on icy and icy roads to use studded tires for heavy vehicles such as trucks and buses instead of studded tires.

Such studless tires are widely used for button tread patterns to achieve high traction and braking force.

The tread knobs are generally provided with axially extending sipes (sipes) for improved traction and braking force, but the narrow elements thus formed move easily during travel and exhibit uneven heel / toe wear along their front / rear edges.

25 Such uneven wear occurs particularly during the early part of the tread's lifetime because of its high wear and tear characteristics.

On the other hand, the rigidity of the tread elements increases as they move from the middle to the final stages and, as a result, wet grip, and in particular ice grip, deteriorates.

The main object of the present invention is to provide a pneumatic 35 tire with improved wet grip and effective prevention of uneven wear.

It is another object of the present invention to provide a 2,103,334 button ring pattern that retains wet grip even during the final phase of tread life.

Yet another object of the present invention is to provide an a-5 button ring with improved wet grip during both direct and curved driving.

According to one embodiment of the present invention, the button pattern ring having the tread member comprises: axial grooves 20 so that the tread portion adjacent and axially inside the axially outermost wide circumferential grooves is provided with a circumferential pole row; extending from said circumferential sipe to an axially inwardly adjacent wide circumferential groove characterized by a button pattern ring that said axial grooves 35 have a depth of 0.2 to 0.5 times the depth of said circumferential grooves so that the base of their 3 103334 is lower than the bottom of the circumferential grooves, that said base of the axial groove is provided with a second sipe extending along its centerline 5; the width of the sip is from 0.2 to 1.1 mm and the length is not less than 0.7 times but less than 1.0 times the length of the axial groove so that the ends 10 of the second sip terminate at the bottom surface and said second sip has a depth of 0.2 - 0.5 times the depth of said circumferential grooves such that the sum of the depth of the second socket and said depth of the axial groove is not more than 0.7 times the depth of the circumferential grooves.

In the following, an embodiment of the present invention will be described in detail with reference to the accompanying drawing, in which:

Fig. 1 is a cross-sectional view of a tire according to the present invention; Fig. 2 is a top view of a tread portion provided with a tread pattern;

Fig. 3 is a section along the line M-M in Fig. 2; Figure 4 is a sectional view taken along line N-N in Figure 2;

Fig. 5 is a graph showing the relationship between the braking performance of an icy road and the circumferential and axial component ratio;

Fig. 6 is a graph showing the relationship between the slip of the icy road and the circumferential and axial component ratio;

Fig. 7 graphically illustrates the relationship between the amount of uneven wear and the circumferential and axial component ratio 5;

Fig. 8 is a cross-sectional view of another tire according to the invention; Fig. 9 is a top view of the tread portion of the previous tire;

Fig. 10 shows a larger tread knob on a larger scale explaining the axial component and the circumferential component of the sapphire;

Fig. 11 shows another example of a tread pattern.

The pneumatic tire 1 of the present invention, shown in Figures 1-4, is a heavy-duty tire for trucks and buses (tire size 10.00R20, rim size 7.50V).

The ring 1 comprises a tread section 22 having a tread surface 2 having two edges, two bellows portions 24 spaced axially, two lateral portions 23 extending between the tread edges and the beads, annular yarn 25 of each of the beads 30. a carcass 26 which extends between the ball members and is folded up around the ball yarns 25, and a belt 27 disposed in the tread portion radially outside the carcass 26.

The frame 26 comprises at least one frame layer of belt or semi-belt type construction. In this embodiment, the frame cords are disposed in the radial direction 103334 so that they form an angle of 70-90 ° with the center line C of the ring. For steel cord, steel cord and organic fiber cord may be used, for example, nylon, polyester, rib-5, aromatic polyamide and the like.

The belt 27 comprises two or more layers, in this case four cross layers, in which the belt cords are disposed parallel to each other but transversely to the cords in the next 10 layers. Steel cords are used for belt cords, but it is possible to use organic fiber cords, which may be, for example, nylon, polyester, rayon, aromatic polyamide and the like.

15

Fig. 2 shows a tread portion 22 provided with circumferential grooves 3 extending uniformly in the circumferential direction of the tire and axial grooves 5 extending axially in the tire to divide the tread portion 20 into at least three rows of buttons. To clarify the circumferential grooves 3, they are shaded in Figure 2.

The axial grooves 5 form the angular direction of the ring. 25 not greater than 30 °.

In this example, the circumferential grooves 3 consist of two parallel wide straight circumferential grooves 3b and two narrow parallel curved circumferential grooves 3a between them.

The axial grooves 5 further consist of a central axial groove 5a extending from one circumferential groove 3a to another circumferential groove 3a, an intermediate axial groove 5b extending from each axial direction to an inner peripheral groove 3a to an adjacent peripheral groove 3a 6b 5c extending from each of the axially extending peripheral grooves 3b to the adjacent edge of the wear surface.

As a result, a center row 15a consisting of center knobs 13a is formed between narrow curved circumferential grooves 3a, two spacer rows 15b consisting of spacers 13b, each located between narrow curvilinear 10 circumferential groove 3a and wide straight circumferential groove 11b , each located axially outside each circumferential groove 3b.

15 The number of pieces in each row ranges from 25 to 60.

The above-mentioned center axial grooves 5a consist of narrow grooves 6a and wide grooves 7a alternating in the circumferential direction of the ring 20.

The axial grooves 7a have the same depth P as the adjacent circumferential grooves 3a.

The axial grooves 6a are lower than the axial grooves 7a or adjacent circumferential grooves 3a.

The aforementioned axial grooves 5b are all shallow grooves 6b which are shallower than adjacent radial grooves 3b.

As shown in Figures 3 and 4, each axial groove 6a, 6b is provided with a sapphire from its base surface 6S.

35 As a result, the rubber beneath the bottom of the lower axial grooves forms a tread support for adjacent knobs during the initial life of the tread, 103334 7 and consequently the movement of the knobs is reduced to prevent uneven wear.

As the tread wear reaches the bottom of the lower axial-5 sliders, the edges of the soaps on the other hand come into contact with the road surface to improve ice grip.

In order to effectively improve ice grip and effectively control the movement of the pieces, axial grooves and soaps are formed in the axi-10 in the following manner: each soap 20 extends along the centerline of the axial groove and terminates at the bottom surface; 15, soaps 20 have a width (Z) of 0.2-1.1 mm; each bar 20 has a length (Y) of 70-100% of the length (X) of the axial groove 6a, 6b at base 6S; The depth (A) of the axial grooves 6a, 6b is 20-50% of the depth (P) of the circumferential grooves 3, 3b; the depth (B) of the soaps 20 is 20-50% of the depth (P) of the circumferential grooves 3a, 3b; and the sum (A + B) of depth (A) and depth (B) is not greater than 70% of depth (P).

If the axial groove depth (A) is greater than 50% of the depth (P) of the circumferential grooves, the stiffness of the tread pattern decreases and the movement of the knobs increases and causes uneven wear.

If the depth (A) is less than 20% of the depth (P), poor-35 snow grip during the initial tread life.

If the soap length (Y) is less than 70% of the length (X) of the axial grooves 103334, the ice holding deteriorates during the middle of the service life.

If the soap depth (B) is greater than 50% of the depth (P) of the circumferential grooves, and particularly when the total depth (A + B) is greater than 70% of the depth (P), the stiffness of the tread pattern is reduced.

If the soap depth (B) is less than 20% of the depth (P) 10, the braking performance deteriorates on icy roads.

The axial groove depth (A) is preferably set in the range of 30-70% of the total depth (A + B), and the width (Z) of the soaps 20 is 10-30% of the width (W) of the axial grooves 6 the combination of axial grooves between mid-to-late ice traction decreases.

To further improve ice grip, the central, intermediate, and shoulder buttons 13a, 13b, and 10 in this embodiment are provided with sinks 21 (21a, 21b, 21c, 21d).

The siphons 21 are deeper than the aforementioned siphons 20, ·. 25 wherein the depth of each sink 21 corresponds to the aforementioned total depth (A + B).

For all soaps 21 formed in the area 30 of the tread in contact with the ground when the tire is mounted on a normal rim and filled with operating pressure and then loaded with normal or operating load, the sum of their circumferential component lengths 35 is EXi 0.7. 1.2 times, preferably 0.85-1.10 times the sum of the lengths of the axial components EYj, and 103334 9 the sum of the lengths of the axial components ZYj is 4.0-10.0 times, more preferably 5.5-10.0 times, and most preferably 6.0 to 10.0 times the maximum axial width of the area in contact with the aforementioned earth 5 TW.

Each central knob 13a is provided with a single axial blade 20a, which is flexively extending from the circumferential groove 3a to the circumferential groove 3a.

10

Each spacer 13b is provided with a plurality of axial blades 20b because of its greater circumferential length. In addition, it is provided with a single circumferential sink 21c.

15

The circumferential soap 21c extends parallel to the outer adjacent circumferential groove 3b in the axial direction. The axial sipes 21b extend directly and parallel to each other from the inner lean-to-siphon-shaped truncated groove 3a to the circumferential siphon 21c and terminate at the circumferential siphon 21c.

Each shoulder piece 10 is provided with a single axial tab 20d which extends directly and axially outwardly from the outermost circumferential groove 3b toward the edge of the wear surface.

In this example, the axial soaps 21a, 21b, and 21d form a shape of 30 at or less than 30 ° in the axial direction of the ring. and the circumferential sipes 21c are parallel to the circumferential direction of the ring. Due to the circumferential soaps 21c, the aforementioned total length of the circumferential components is increased to meet the above-mentioned limitations.

Figures 5, 6 and 7 show the results of the braking test, the slip test and the uneven wear test.

In the braking test shown in Fig. 5, it was confirmed that the braking effect was reduced if the ratio EXi / ECj 5 was either less than 0.7 or greater than 1.2.

In the slip test shown in Fig. 6, it was confirmed that the lateral slip resistance or ice grip during curvature reduction was reduced if the 10 ratio EXi / TW was less than 4.0.

If the ratio ΣΧΐ / TW is greater than 10.0, the stiffness of the knobs will decrease and both wet and dry grip will deteriorate.

In the uneven wear test, heel / toe wear after a 40,000 km run was also measured and, as shown in Figure 7, there was confirmation that the uneven wear (heel / toe wear) was effectively reduced by setting the ratio EXi / ECj to the above 20.

Figures 8 to 10 show a pneumatic ring having five circumferential grooves for forming a button pattern comprising six of the buttons with soaps. 25 formed rows in which the total circumferential component length EXi and the total axial component length ΣΥj are determined as described above.

In Fig. 8, ring 1 is a heavy-duty tire 30 with rectangular shoulder portions. (tire size 10.00R20, rim size 7.50V)

The ring 1 comprises a tread portion 2 having a button pattern on its tread S, two bead members 4 spaced apart in axial direction 35, two side members 3 extending between the tread edges and the bead members, two diaphragm yarns 5 each of which a bead portion 4, a carcass 6 extending between the bead portions 4 and folded up around the bead yarns 5, and a belt 7 disposed radially outside the carcass and within the rubber wear surface 5.

The tread section 2 is provided with five circumferential grooves G and an axial groove M to form a button pattern having a sea / land 10 ratio of about 35/65.

These five circumferential grooves G comprise a single meandering circumferential groove GO extending along the tire centreline C, two straight circumferential grooves G1 and two axially extending outer circumferential grooves G2.

The serpentine circumferential groove comprises alternating groove segments (gl) forming an angle of 15-20 to 30 ° and groove segments (g2) forming an angle of 75-60 ° with the circumferential direction of the ring.

The axial grooves M comprise an axial groove MO extending from a circumferential center groove GO to a circumferential groove G1, an axial groove M1 extending from a circumferential intermediate groove G1 to a circumferential outer groove G2, and an axial groove M2 extending from a peripheral outer groove edge G2.

Each of the axial grooves MO and M1 comprises two segments (ml and m2) forming an angle of 15-30 ° with the axial direction of the ring to form a V-shaped pattern.

Each of the axial grooves M2 comprises a segment (m3) which forms an angle of 15-30 ° with the axial direction of the ring, and a segment (m4) which forms substantially 0 ° 103334 with an angle 12 of the ring.

The axial grooves M0, M1, and M2 are arranged so that they extend elusively from one tread edge to the other tread edge with the left side tilted up (Fig. 8) or the right side tilted up. The ends of the axial grooves on each side of each circumferential groove G2 are shown in Fig. 8 in a slightly stepped manner. The axial grooves are arranged in 10 regular intervals or in regular intervals, but they can be arranged in irregular intervals or in variable intervals.

Each button BO in the center button rows RiO is provided with three parallel axial soaps KaO extending from groove G0 to groove G1 parallel to the axial grooves MO so that they form a V-shaped pattern.

Each of the knobs B1 in the spacer rows Ril is provided with one circumferential sipe Kbl extending parallel to the axially extending circumferentially adjacent circumferentially extending peripheral groove G2, and three parallel axial flaps Kai extending axially from the circumferentially adjacent circumference forming a V-shaped pattern.

30

Each knob B2 in the outer knob rows Rs is provided with one axially inner circumferential socket Kb2 extending parallel to the axially directionally adjacent circumferential groove G2 35, with two parallel axially extending outer circumferentially spaced tabs Kb2. extending axially between the inner and outer circumferential soaps Kb2 and Kb3, parallel to the axial grooves M2.

These saps K (KaO, Kai, Ka2, Kb1, Kb2, Kb3) are 0.3-1.5 mm wide, preferably 0.5-1.0 mm wide.

As described above, the area Q in contact with the ground will settle under conditions where the tire is mounted on a normal rim and inflated to a normal pressure and then loaded with an operating or normal load 15 of the total lengths of the the ratio EXi / ECj between 0.70 and 1.2, and the ratio EXi / TW of the aforementioned total length of the circumferential components and the width TW in contact with the ground, between 4.0 and 10.0.

At 10.00R20, the tire has a standard rim size of 7.50V, a 25 normal pressure of 7.25 kp / mm2, and a normal tire load of 2700 kg.

Fig. 10 shows the lengths Xi of the circumferential components of one seam K (KaO) and the length Yj of the axial component 30.

The ground contact width TW is the maximum axial width of the area Q in contact with the ground. In this example, the ground contact width TW is essentially equal to the tread width between the tread edges.

103334 14

Figure 11 illustrates another example of a button latching surface pattern, wherein the button pattern comprises a straight circumferential groove GO, two curving circumferential grooves G1, two axially outermost 5 straight circumferential grooves G2, and two center-forming ribs forming an axial groove. Ril, and to form two rows of outer knobs, Rs. Each knob is provided with a plurality of axial syllables K. Each knob 10 in the spacer rows Ril is provided with two circumferential syllables Kbl in the same manner as above, and its axial syllables Kai terminate axially axially inside the innermost circumferential syllable Kbl.

Claims (3)

103334 15 A button pattern ring having a tread portion (2, 22) 5 comprising two axially outermost wide circumferential main grooves (3b, G2), each of which is disposed on each side of the ring center line (C), at least one of axial grooves (5; M) extending between a wide circumferential main groove (3a; G1, G1) and adjacent wide circumferential grooves (3a, 3b; 15 G0, G1, G2) such that the tread portion (2, 22) is axially extending outermost wide circumferential grooves (3b; G2) adjacent and axially within them is provided with a circumferential-row of buttons (15; Ri), each button (13; B) is provided with a plurality of axial saps (21a, 21b, Ka) and a circumferential socket (21c, Kb). , which saps (21a, 21b, 21c; Ka, Kb) are ka-. 25 greater than the circumferential grooves (3; G) and the axial grooves (5; M), said axial flaps (21a, 21b; Ka) extend from said circumferential flange (21c, Kb) to an axially wide main circumferential groove (30); 3; G), characterized in that said axial grooves (5; M) have a depth of 0.2 to 0.5 times the depth of said circumferential grooves (3, G) so that their bottom is lower than the circumferential grooves (3, G). G) a base, wherein said base of the axial groove (5; M) is provided with a second siphon (20) extending along its centerline, wherein said second siphon (20) has a width of 0.2 to 1.1 mm and a length of not less than 0. , 7 times but less than 1.0 times the length of the axial groove (5; M) so that the ends of the second sapphire (20) terminate at the bottom surface, and that the depth of said second sapphire (20) is 0.2 to 0.5 times the depth of the grooves (3, G) such that the depth of the second siphon (20) and the sum of said depth of the axial groove (5; M) is not more than 0.7 times the 15 circumferential grooves (3; G) Depth. Ring according to Claim 1, characterized in that said circumferential soap (21c; Kb) extends along the outermost wide circumferential main groove (3b; G2). 20 Tire according to claim 1 or 2, characterized in that the tread section (22) is provided with treads (21) having a width of 0.3 to 1.5 mm including said axial traps (21a, 21b, Ka). and 25 circumferential saps (21c; Kb), and for all soaps (21; Ka, Kb) in contact with the ground on the tread (2), the quotient of the total length of their circumferential components and the total length of their axial components lies between 0.70 and 1.2 , and is the quotient of the total length of the circumferential components and the maximum axial width of the area in contact with said ground surface, ranging from 4.0 to 10.0. 5 17 103334