JPH0481306A - Deep grooved tire for driving wheel of agricultural tractor - Google Patents

Abstract

PURPOSE:To narrow the distance between ridges or rows and generate a high tractive force on the work in plowland of paddy field and plowed field by specifying the width of lug row composed of lugs, the ratio of the width of lug row to a drop amount from the maximum radius of tire and tire width directional inner angle of the lugs. CONSTITUTION:A plurality of staggered lugs 14 are provided in the peripheral direction on both sides of the equatorial surface on the peripheral portion from the neighborhood of an equatorial surface 16 on the tread portion 12 of a tire 10 to a side wall portion 13. In this case, the grounding shape of each lug 14 is approximately linear wherein a width directional inner angle alpha between a front side ridgeline 14c in the rotational direction at the width directional outer edge and the rotational direction A is set in a range from 30 to 55 degrees. A width TW of the lug row composed of the lug 14 is not more than maximum width SW of a portion not including the tread 12 (the side wall portion 13). Further, the ratio D/TW of a fall height D, from the maximum radius, of an intersection P of an extension line M to be extended along an outer contour line 14A from neighborhood of the equatorial surface 16 to and an extension line N to be extended from an outer side 14D in the width direction of the lug 14 to outside in the radius direction is set in a range from 0.5 to 3%.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a drive wheel deep groove tire for an agricultural tractor used both in paddy fields and fields.

[Conventional technology]

Traditionally, deep groove tires for agricultural tractor drive wheels installed on agricultural machinery such as tractors have been used for paddy fields with high lug height and wide tread width, so-called high-lag tires (
For field use, so-called average lug tires (general groove tires) have low lug height and narrow tread width.
The general rule is to use .

However, due to changes in agricultural conditions in recent years, field crops have also changed, and conventional high-lag tires and medium-lag tires have encountered problems.

One of them is conventional high horsepower tractors (mainly 30PS).
The towing work in the fields, which used to be done by a small-scale farmer (class or above), is now being carried out by a small-scale farm near the city using a small-horsepower tractor (approximately 2-horsepower tractor).
PS class or lower). In this case, in addition to the light weight of the tractor, there is a problem in that it is difficult to obtain sufficient traction with medium lug tires with low lugs.

On the other hand, when using high-lug tires with wide treads to build soil in a field to create ridges for cultivation, the distance between the ridges should be adjusted to avoid stepping on adjacent ridges. The problem is that it has to be spread out over a wide area, resulting in fewer crops being planted. In addition, when applying mulch film, it is necessary to leave wide intervals between rows so as not to step on the mulch film, resulting in a problem in that fewer crops can be planted.

Furthermore, in the process of applying mulch film, soil adhering to the tire falls onto the mulch film while the tire is rotating, causing weeds to grow on top of the mulch film.

[Problem to be solved by the invention]

The present invention has been developed in consideration of the above facts, and has advantages such as narrowing the spacing between ridges or between rows in field work such as rowing and mulching. The object is to obtain a drive wheel deep groove tire for an agricultural tractor that can generate high tractive force in farmland work.

[Means and effects for solving the problem] In order to achieve the above object, the present invention provides that lugs extending from the vicinity of the tire equatorial plane of the tread portion to the sidewall portion are staggered in the tire circumferential direction on both sides of the tire equatorial plane. A drive wheel deep-groove tire for an agricultural tractor, in which a plurality of lugs are arranged in the radial cross section of the tire, and the starting end of each lug near the tire equatorial plane is located forward in the tire rotational direction from the end of the sidewall part, and The width TW of the row is set to be less than or equal to the tire maximum width SW excluding the lugs, and the extension line extending from near the tire equatorial plane to the tire outer line and the outer side of the lug in the tire width direction is set to the outside in the tire radial direction. The ratio D/TW of the drop height from the tire maximum radius at the intersection with the extended line extended to 0. 5% to 3%, and the outer end of the lug in the tire width direction is rounded, and the tire width formed by the front ridge line in the tire rotation direction of the lug at the tire width direction outer end and the tire rotation direction. Direction inside angle 3
It is characterized by being set at 0 to 55 degrees.

Therefore, in an agricultural machine equipped with the drive wheel deep groove tire for an agricultural tractor of the present invention, during field work such as rowing and mulching, the distance between ridges or the distance between rows is reduced. In addition to having advantages such as being able to carry out heavy lifting, it is also possible to generate high traction force in paddy field and farmland work.

In other words, in order to narrow the spacing between the ridges or the spacing between the rows of mulch film, it is essential to adjust and modify the tractor itself as an agricultural machine, especially the wheel width, but there are limitations and limitations on the tractor itself. Tires play an important role in the running part of the tractor body as a component. Usually, as shown in FIGS. 3 and 4, a high-lug tire 40 used for a tractor of 2 OPS class or less has a lug 42 extending from the vicinity of the tire equatorial plane 46 of the tread portion to the sidewall portion in the tire rotation direction. They are provided in a staggered manner in the direction indicated by the arrow in Figure 4). In addition, the width TW of the lug row made up of these lugs 42 (the lug height at the equatorial plane 46) is the maximum width SW of the tire not including the lugs 42.
Therefore, it is necessary to run the tire away from the ridges and the mulch film by the width LW of the end portion 42A of the lug 42 that protrudes outward in the tire width direction from the tire case 844.

Therefore, in order to obtain advantages such as narrowing the spacing between ridges or the spacing between rows in field work such as making rows and mulching, the width TW of the lug rows should be adjusted to include the lags. It is preferable that the width SW is equal to or less than the maximum width SW of the portion without the width SW.

On the other hand, narrowing the width TW of the lug row reduces the area of the lugs, thereby reducing the traction performance of the tire. Especially in soft paddy fields, how much soil is trapped between the lugs has a large effect on traction.

Furthermore, even in the case of a so-called deep groove tire, if the lug height L is made extremely large, there will be manufacturing problems such as the ply cord being disturbed by the sucking of rubber during vulcanization.

Furthermore, it is difficult to maintain lug rigidity and is less effective.

That is, in the present invention, it is important how to compensate for the decrease in traction caused by narrowing the width TW of the lug row.

Therefore, in order to improve traction, the intersection of an extension line extending from near the tire equatorial plane along the tire external line with respect to the TW and an extension line extending the outer side of the lug in the tire width direction outward in the tire radial direction. It is preferable to set the ratio D/TW of the drop height from the maximum radius to 0.5% to 3%.

On the other hand, when applying mulch film, even if we improve the width of the lugs and take precautions when driving, there are many cases where the film is broken by stepping on it. For this reason, it is preferable that the lug ends have a rounded shape.

Therefore, the curvature R of the round shape is desirably about 4% to 13% of the width TW of the tire's lug rows; if it is too large, the area of the lugs will be reduced and the traction performance will be reduced; if it is too small, the film will be protected. The effect of doing so disappears.

In addition, when running, the front side of the lug in the direction of rotation compresses or shears the soil, gaining reaction force from the soil and driving. At this time, soil adheres to the lugs, and as the lug rotates, the adhered soil falls to the side of the tire and remains on the mulch film. In particular, as shown in FIG. 4, soil adhering to the end portion (outer end portion in the tire width direction) 42A of the lug 42 becomes a problem. This soil adhesion increases as the inner angle α in the tire width direction formed by the tire rotation direction front ridge line 42F of the lug 42 at the tire width direction outer end and the tire rotation direction approaches 90°; decreases as becomes smaller. This is lug 4 within the ground plane.
As the tire advances (rotates), the soil held by the tire tries to move outward from the equatorial plane 46 along the front surface of the lug 42, but when the angle α becomes 90°, no outward force is generated. Since all of the soil is directed toward the lug 42, the amount of soil adhered increases, and conversely, as the angle α becomes smaller, the force directed outward along the lug 42 increases, so the amount of soil adhered decreases.

Therefore, in order to reduce the amount of soil adhering to the end portion 42A of the lug 42, the angle α may be reduced, but as the angle α becomes smaller, the reaction force of the soil becomes smaller.
Traction performance deteriorates.

Therefore, the inner angle α in the tire width direction formed by the front ridge line in the tire rotation direction of the lug at the outer end in the tire width direction and the tire rotation direction is best between 30° and 55°.

〔Example〕

An embodiment of the present invention will be described with reference to FIGS. 1 and 2.

As shown in FIGS. 1 and 2, the outer circumference of the tire from the vicinity of the tire equatorial plane 16 of the tread portion 12 of the agricultural tractor drive wheel deep groove tire 10 of this embodiment to the sidewall portion 13 has a tire equatorial plane. A plurality of lugs 14 are provided on both sides of the tire in a staggered manner in the tire circumferential direction.

As shown in FIG. 2, the ground contact shape of these lugs 14 corresponds to the tire width formed by the tire rotation direction forward side ridge line 14c at the outer end in the tire width direction and the tire rotation direction (direction of arrow A in FIG. 2). It has a substantially linear shape with an inner direction angle α of 30° to 55°.

Furthermore, the width TW of the lug row made up of these staggered lugs 14 is set to be less than or equal to the maximum width SW of the portion (sidewall portion 13) that does not include the tread 12.

Also, with respect to TW, the intersection point P between an extension line M extending from near the tire equatorial plane 16 along the tire external line 14A and an extension line N extending the tire width direction outer side 14D of the lug 14 outward in the tire radial direction. The ratio D/TW of the drop height from the tire maximum radius is set to 0.5% to 3%.

The end portions 14B of the lugs 14 have a round shape with a curvature, and the curvature R is approximately 4% to 13% of the width (tread width) TW of the lug rows of the tire 10.

Therefore, the drive wheel deep groove tire 1 for agricultural tractors of this embodiment
Agricultural machinery equipped with 0 has the advantage of being able to narrow the spacing between ridges or the spacing between rows during field work such as rowing, mulching, etc. It can generate high traction force in field work.

(Experiment example) Drive wheel deep groove tires for agricultural tractors of this example (first example and second example) with specifications shown in Table 1 and drive wheels for agricultural tractors of comparative examples 1 to 5. deep groove tires,
It was attached to a small 17PS tractor and measured for traction performance, mud removal, and mulch film tearing.

From the results shown in Tables 1 and 2, it is clear that the deep groove tires for drive wheels for agricultural tractors of the present invention are particularly excellent.

〔Effect of the invention〕

Since the present invention has the above configuration, it has advantages such as being able to narrow the spacing between ridges or the spacing between rows in field work such as making rows and mulching. It has the excellent effect of being able to generate high traction force during work.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing the upper left half of a drive wheel deep groove tire for an agricultural tractor according to an embodiment of the present invention, with hatching omitted along the tire meridian, and FIG. 2 is a cross-sectional view of an agricultural tractor according to an embodiment of the present invention. A line diagram showing the ground contact shape of the lug of a drive wheel deep groove tire. Fig. 3 is a cross-sectional view showing the upper left half of a conventional drive wheel deep groove tire for an agricultural tractor with hunting omitted along the tire meridian. FIG. 2 is a diagram showing the ground contact shape of a lug of a conventional deep groove tire for a drive wheel for an agricultural tractor. 10... Driving wheel deep groove tire for agricultural tractors, 12...
・Tread part, 13... Sidewall part, 14... Lug, 14A... Tire external line, 14C... Front side ridge line, 14D... Tire width direction outer side, 16... Equatorial plane . Fig. 10 Kuiya for agricultural and cold horizontal rams 12Fl, F: gl1 13 Sidewall sound p 14 Raku 16: -i, J side Fig. Fig. Fig. 10

Claims (1)

[Claims] (1) A plurality of lugs extending from near the tire equatorial plane of the tread part to the sidewall part are arranged in a staggered manner in the tire circumferential direction on both sides of the tire equatorial plane, and the starting end of each lug near the tire equatorial plane is on the sidewall. A drive wheel deep groove tire for an agricultural tractor located forward in the tire rotational direction from the end of the tire, in which the width TW of the lug row consisting of the lugs in the tire radial cross section is equal to the tire maximum width SW excluding the lugs.
Set as below, from the tire maximum radius at the intersection of the extension line extending from near the tire equatorial plane along the tire external line to the TW and the extension line extending the tire width direction outer side of the lug outward in the tire radial direction. Ratio D/TW of falling height D is 0
．． 5% to 3%, and the outer end of the lug in the tire width direction is rounded, and the tire width formed by the front ridge line in the tire rotation direction of the lug at the tire width direction outer end and the tire rotation direction. A deep groove tire for a drive wheel for an agricultural tractor, characterized in that the inside angle is set at 30 to 55 degrees.