JPH03169708A - Tire for agricultural machine - Google Patents

Abstract

PURPOSE:To simply and reliably prevent collapse of the side wall of a filed ridge by means of a tire by setting the tread width of a tread so that an angle of a tangential line for interconnecting a tread part and a tire side part with an earthing surface is set to a value lower than a specified value. CONSTITUTION:Lags 24 are protruded at intervals of a given distance in the peripheral direction of a tire from the outer peripheral part of a tread 22 of a pneumatic tire 10. Angles theta of tangential lines 30 for interconnecting two end parts 26 in the direction of the width of a tire of a tip part 24A of the lag 24 being the tread end part of the tread 22 and a tire side part 28 with an earthing surface 32 are respectively set to 60 deg. or less. A tread width TW of the tread 22 is set to 20mm or more. When the pneumatic tire 10 is moved aside from the root part of the field ridge of a rice field, a side part 28 is brought into smooth contact with the side wall part of the field ridge before two ends 26 tread in the side wall part of the field ridge. This constitution prevents collapse of the side walls of the field ridge and breakage of a vinyl stretched thereover.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a tire for an agricultural machine that runs on a field where row crops are cultivated.

[Conventional technology]

Various types of agricultural machinery perform tasks such as tilling, sowing, fertilizing, pest control, and harvesting in the field. For this reason, the agricultural machinery tires installed on these agricultural machinery are equipped with a pattern called a lug on the tire road surface in order to ensure sufficient running performance in the field. It is gaining momentum.

Therefore, in conventional tires for agricultural machinery, in order to increase running efficiency, the size of this lug, that is, the tread road surface width TW, is approximately the maximum width of the tire.

However, since most field crops are cultivated by ridge cultivation, agricultural machinery that performs operations such as tillage, sowing, fertilization, pest control, and harvesting must travel within the field by straddling the ridges.

In this case, as shown in FIG. 4, the width A of the ridges 50 and the ridge interval B are set depending on the characteristics of the crop, regional characteristics, cultivation efficiency, etc., but generally the ridge interval B is narrow, When the agricultural machinery tire 52 runs between furrows, the lug portion 54 collapses the side wall 50A of the ridge 50, reducing the amount of soil covering the root 56A of the crop 56, or in severe cases, damaging the root 56A of the crop 56. was there. In addition, there was a problem in that the vinyl 58 stretched on the ground surface for mulch cultivation was broken, adversely affecting the water retention within the ridges 50, and causing problems such as the proliferation of weeds.

[Problem to be solved by the invention]

In consideration of the above-mentioned facts, the present invention aims to provide a tire for agricultural machinery that can prevent the side walls of ridges from collapsing and the vinyl stretched on the ground surface from being torn.

[Means to solve the problem]

In order to achieve the above object, the present invention as set forth in claim (1) provides a trend road surface width TW in which the angle formed between the tangent line connecting the tread road surface end and the tire side portion and the ground contact surface is 60 degrees or less.
It is characterized by having the following.

Further, the present invention according to claim (2) provides a tread road surface width T
W satisfies the formula ▼2W/COS30@-Htan3Q°≧▼2TW for the tire maximum width W on the contact surface side and the tire radial direction distance H from the tire equator to the tire maximum width position on the contact surface side. It is a feature.

Further, the present invention as set forth in claim (3) is the invention set forth in claim (1) or claim (2), in which the tread road surface width TW is
is 20 mm or more.

[Effect]

In the present invention as described in claim (1) above, the angle formed between the contact area connecting the tread road surface edge and the tire side portion and the contact surface is 6
Since the tire has a tread surface width TW of 0° or less, the tire side portion smoothly contacts the side wall of the ridge before the lugs contact the side wall of the ridge and collapse the side wall of the ridge. Therefore, it is possible to prevent the rug from stepping into the hem of the side wall of the ridge, collapsing the side wall of the ridge, or tearing the vinyl stretched over the ground surface.

In addition, if the tread surface width TW is less than 20 mm, there is a risk of subsidence to the soil when the soil is muddy during rainy days, so the tread surface width TW should be set to 20 m.
m or more is preferable.

In the present invention as described in claim (2) above, the tread road surface width T
W is the tire maximum width W on the contact surface side and the tire radial direction distance H from the tire equator to the tire maximum width position on the contact surface side.
In order to satisfy the formula '/2TW, the tire side portion smoothly contacts the side wall of the ridge before the lug contacts the side wall of the ridge and collapses the side wall of the ridge. Therefore, it is possible to prevent the rug from stepping into the hem of the side wall of the ridge, collapsing the side wall of the ridge, or tearing the vinyl stretched over the ground surface.

In addition, if the tread road surface width TW is less than 20 mm, there is a risk of subsidence to the soil when the soil is muddy during rainy days, so the tread road surface width TW should be set to 20 m.
m or more is preferable.

〔Example〕

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

As shown in FIG. 2, the agricultural machine 12 equipped with the agricultural machine pneumatic tire 10 as the agricultural machine tire of this embodiment is configured to travel within a field by straddling ridges 14.

The width L of this ridge 14 is, for example, 200 mm, and the maximum ridge interval M1
is, for example, 250 mm, the minimum ridge interval M2 (width of the trough portion 14B) is, for example, approximately 75 mm, the distance N from center to center of the ridge 14 is, for example, 450 mm, the height S of the ridge 14 is, for example, 150 mm, and the side wall of the ridge 14 is, for example, 250 mm. The inclination angle α of 14A is, for example, 60°.

In addition, each of these values L, Ml, M2, NSS and α are as follows:
It is set depending on the characteristics of each crop, regional characteristics, cultivation efficiency, etc.

In addition, in the ridge 14, a crop 16 such as cabbage is planted along the ridge 14 (in the direction perpendicular to the page of FIG. 2), and the crop 1
The root 16A of No. 6 is buried underground in the ridge 14.

In addition, for example, in the case of mulch cultivation, one layer of vinyl is placed on the ground surface.
On top of the vinyl 18B stretched on the ground surface in the valley l4B between the ridges 14, soil 20 is piled up to hold down the vinyl 18.

As shown in FIG. 1, lugs 24 are protruded from the outer periphery of the tread 22 of the pneumatic tire 10 for agricultural machinery according to this embodiment at predetermined intervals in the tire circumferential direction. this rug 2
The tire meridian cross-sectional shape of No. 4 is approximately trapezoidal. Further, an angle θ between a tangent line 30 connecting both ends 26 in the tire width direction of the tip end portion 24A of the lug 24 as a tread road surface end portion and the tire side portion 28 and the ground contact surface 32 is 60° or less. .

Further, the tread road surface width TW is set to be 20 mm or more.

Note that the reference numeral 33 in FIG. 1 indicates the tire equatorial plane.

Next, the operation of this embodiment will be explained.

If the agricultural machine pneumatic tire 10 comes off the approximate center of the trough 14B of the ridge 14 while the agricultural machine 12 of this embodiment is running in the field across the ridge 14, the tip of the lug One of both ends 26 in the tire width direction is connected to the side wall 14A of the ridge 14.
or the hem of the inclined surface 18B of the vinyl 18, the inclined side portion 28 smoothly contacts the side wall 14 of the ridge 14 or the inclined surface 18B of the vinyl 18. This can prevent the side n14A of the ridge 14 from collapsing or tearing the vinyl 18 stretched on the ground surface. In addition, since the torpedo road surface width TW is set to be 20 mm or more, the soil may become muddy during rainy days. Even in the case where the pneumatic tire 10 for agricultural machinery is submerged in the soil, sufficient running performance can be obtained.

Next, a second embodiment of the present invention will be explained with reference to FIG.

Incidentally, the same members as in the first embodiment are given the same reference numerals and the explanation thereof will be omitted.

As shown in FIG. 3, in the pneumatic tire 40 for agricultural machinery of this embodiment, the tread road surface width TW is the maximum tire width W on the contact surface side and the tire maximum width W on the contact surface side from the tire equator 42 to the tire maximum width position 46. For the radial distance H of
1) is satisfied.

/2W/COS30@-Htan30゜≧wa, TW
... (1) Here, the lth term'/2W/C O S 3 0 of formula <1)
° indicates the distance X in FIG. 3, and the second term Htan30° in equation (1) indicates the distance Y in FIG.

Therefore, the tread surface width TW of the pneumatic tire 40 for agricultural machinery is calculated from the tire maximum width W and the radial distance H from the tire equator 42 to the tire maximum width position 46 using the formula (1).
is smaller than twice the value calculated on the left side of . Therefore, the pneumatic tire 40 for agricultural machinery of this embodiment also provides the same effects as those of the first embodiment.

(Experimental example) The ridges 14 shown in Fig. 2 (width L = 200 mm, maximum ridge interval Ml = 250 mm, minimum ridge interval M2'' = .75 mm,
Distance from center to center of ridge N = 450 mm, ridge 1
A conventional pneumatic tire for agricultural machinery with the specifications shown in Table 1 (tire size is AG400) is installed in a field in which the height S of the ridge 14 is 150 mm and the inclination angle α of the side wall 14A of the ridge 14 is 60°. -9 2PR) A and the pneumatic tire for agricultural machinery of the present invention (tire size is AG400-9
2PR) We conducted a driving test with B.

The test results are shown in Table 2.

/ From the results shown in Table 1 and Table 2, it is clear that the tire for agricultural machinery of the present invention is particularly excellent.

〔Effect of the invention〕

Since the present invention has the above structure, it is possible to collapse the side walls of the ridge,
It has the excellent effect of preventing vinyl etc. placed on the ground surface from being torn.

[Brief explanation of the drawing]

FIG. 1 is a sectional view along the tire meridian showing a tire for agricultural machinery according to a first embodiment of the present invention, and FIG. 2 is a sectional view along the tire meridian showing a tire for agricultural machinery according to the first embodiment of the present invention and ridges FIG. 3 is a sectional view taken along the tire meridian showing a tire for agricultural machinery according to a second embodiment of the present invention, and FIG. 4 is a sectional view taken along the tire meridian showing a conventional tire for agricultural machinery. It is. DESCRIPTION OF SYMBOLS 10... Pneumatic tire for agricultural machinery, 26... Tire width direction both ends, 28... Tire side part, 30... Tangent line, 32... Ground contact surface, 42... Tire equator, 46 ...Tire maximum width.

Claims (3)

[Claims] (1) A tire for agricultural machinery characterized by having a tread road surface width TW such that the angle formed between the tangent line connecting the tread road surface end and the tire side portion and the ground contact surface is 60 degrees or less. (2) The tread road surface width TW is the maximum width of the tire on the contact surface side W
and (1/2W)/cos30 for the tire radial direction distance H from the tire equator to the tire maximum width position on the contact surface side.
A tire for agricultural machinery, characterized in that it satisfies the following formula: ゜-Htan30゜≧1/2TW. (3) The tire for agricultural machinery according to claim (1) or claim (2), wherein the tread road surface width TW is 20 mm or more.