JP2537664Y2 - tire - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial application field) The present invention relates to a tire used for, for example, an agricultural tractor.

(Prior Art) For example, tires of agricultural tractors are provided with relatively tall lugs at circumferential intervals from the tread to the shoulder in order to obtain traction in fields such as wetlands and semi-wetlands. ing.

(Problems to be Solved by the Invention) Conventional tires sometimes cause clogging of mud between lags when traveling in the field, and the tractive force may be reduced because the vehicle travels without removing the mud. The higher the lag, the more noticeable.

By the way, there is a technique in which lugs having different axial lengths are alternately arranged on lugs of a tread portion to increase traction force (see Japanese Patent Application Laid-Open No. 60-244606).

However, even in this technique, it is difficult to prevent a decrease in traction force due to clogging with soil and mud, and it is not possible to improve soil discharging performance.

An object of the present invention is to provide a tire in which a small lug having a lower thickness and a smaller thickness is arranged between main lugs so that clogging mud can be eliminated by utilizing elastic deformation of the small lug. I do.

(Means for Solving the Problem) A specific configuration for solving the problem in the present invention is to dispose main lugs 6 at intervals in the circumferential direction from the tread portion 2 to the shoulder portion 3, and between the main lugs 6. In a tire in which a small lug 7 whose length on the tread portion 2 is shorter than the main lug 6 is arranged, the small lug 7 is formed to be lower than the main lug 6 and to have a small thickness t in the circumferential direction.

(Operation) When the small lug 7 is stepped into the mud while traveling on the field, the small lug 7 is elastically deformed so as to bend toward the trailing side in the rotational direction, and the mud is moved between the main lugs 6 where the small lug 7 is arranged. Even if clogged, when the part comes out of the mud and is released from the traction resistance, the small lug 7 elastically restores and discharges the mud clogged between the small lug 7 and the main lug 6, Eliminate clogged mud.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

1 to 3, reference numeral 1 denotes a pneumatic tire used for a driving wheel of an agricultural tractor, which has a tread portion 2, left and right shoulder portions 3, left and right sidewall portions 4 and left and right bead portions 5, and a tread portion 2. The main lug 6 and the small lug 7 are provided from to the right and left shoulder portions 3.

The main lugs 6 are relatively tall, tapered from the base 6a to the tip 6b, are arranged at required intervals in the tire circumferential direction, and the main lugs 6 on the left and right (in the tire axial direction) are arranged in a staggered manner. I have.

The main lug 6 is formed in an arc shape from the center of the tire to the left and right sides, and the center side end is a leading side in the tire rotation direction (usually, the rotation direction when the vehicle advances). However, the main lug 6 may be formed linearly in a plan view, or may be parallel to the tire axial direction.

The small lugs 7 are arranged one by one between the main lugs 6, and are offset from the center between the main lugs 6 on the trailing side in the rotation direction, and are located near the leading surface 9 of the main lug 6.

The small lug 7 has a tapered shape from the base 7a to the tip 7b, and its thickness t in the rotation direction is smaller than the thickness T of the main lug 6 and is made of the same material as the main lug 6.
The rigidity is lower, and the height is set lower than the main lug 6.

The axial length of the small lug 7 is set shorter than the main lug 6 in the tread portion 2, and the side end on the shoulder portion 3 side is formed to be the same as the main lug 6.

Although the small lug 7 is arranged in an arc shape in a plan view and arranged in parallel with the main lug 6, the small lug 7 may be formed in a straight line shape, and the circumferential position of the small lug 7 is the main lug on the trailing side in the rotation direction. The distance 1 from the lug 6 is good up to about two-thirds of the distance L between the main lugs 6, but the small lug 7 bends to the trailing side. Is preferred. However, it is necessary to form a gap S between the small lug 7 and the main lug 6 on the succeeding side to allow the small lug 7 to be elastically deformed.

It is possible to extend the end of the small lug 7 on the center side of the tire to the same position as that of the main lug 6, but it is too close to the main lug 6 on the right and left opposite sides and the main lug has drainage and soil discharging properties. Can be adversely affected, and there is little mud clogging in the center of the tire, and there is little need to extend it.

When the tire 1 is rolled in mud such as a wetland, the fourth
As shown in the figure, a small lug 7 having a lower rigidity than the main lug 6
It is elastically deformed by the traction resistance of the mud and bends so as to approach the main lug 6. The mud clogged between the main rugs 6 is entrained when the main rug 6 is pulled out of the mud. However, when the main rug 6 is drawn out of the mud, the traction resistance is lost. The state is restored, and the clogging mud between the small lug 7 and the main lug 6 ahead of the small lug 7 is discharged so as to be compressed and discharged by the restoring force.

Although the gap S between the small lug and the main lug 6 behind it may be clogged with mud, the deformation and restoration of the small lug 7
The gap S expands, and the clogged mud falls naturally.

FIG. 5 shows a modified example of the small lug. The outer portion of the small lug 7 'protrudes more in the tire axial direction than the main lug 6, and the inner portion is located closer to the center of the tire than in the previous embodiment. ing. The small lugs 7 ′ may be formed of a material having a lower rubber hardness than the main lugs 6.

This small lug 7 'undergoes greater traction resistance and undergoes large elastic deformation as compared with that of the above embodiment. Therefore, the restoring force is large, and the clogging mud is more reliably eliminated.

In addition, this invention is not limited to the said Example etc., can be variously deformed, and can be applied also to a low pressure tire, a tire for civil engineering / construction machinery, etc.

(Effects of the Invention) According to the present invention described in detail above, the small lugs 7 disposed between the main lugs 6 are formed to be lower and thinner than the main lugs 6, and thus have lower rigidity than the main lugs 6. When traveling on the road, it does not touch the ground, and when traveling in mud, the small lug 7 performs elastic deformation and restoring action, and even if the mud is clogged with the main lug 6, it can be eliminated. When traveling on the road, there is no wear due to ground contact, and durability can be provided.

[Brief description of the drawings]

1 to 4 show an embodiment of the present invention. FIG. 1 is a perspective view, FIG. 2 is a sectional view, FIG. 3 is a development view, FIG. 4 is an operation explanatory view, and FIG. It is sectional drawing which shows an example. 1 ... tire, 2 ... tread, 6 ... main lug, 7 ...
... Small lugs, t, T ... Thickness, S ... Gap.

 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-60-244606 (JP, A) JP-A-48-24404 (JP, A) JP-A-59-227511 (JP, A) JP-A-58- 139804 (JP, A) JP-A-2-28006 (JP, A) JP-A-56-124502 (JP, A) JP-A-1-160710 (JP, A) JP-A-1-293206 (JP, A) 3-93202 (JP, U) JP-B 33-7701 (JP, B1)

Claims (1)

(57) [Scope of request for utility model registration] A main lug (6) is arranged at intervals in the circumferential direction from a tread portion (2) to a shoulder portion (3), and a main lug (6) is arranged between the main lugs (6) on the tread portion (2). In a tire having a small lug (7) shorter than the main lug (6), the small lug (7) is formed to be lower than the main lug (6) and to have a small circumferential thickness (t). A tire characterized by the following.