JPS58152608A - Tire serving concurrently as soft ground running use - Google Patents

Abstract

PURPOSE:To make the titled tire into a low noise, low oscillation and high speed stabilized running one, by constituting one mode through a positive and a negative direction half modes obtained by arranging a group of tread groove forming sections at gradually reducing pitches and constituting in the manner that this mode is arranged on both sides of a tread by providing a phase difference in the reverse order. CONSTITUTION:A group of sections 12 provided so as to decrease pitches down to ln- lo stepwise in a circumferential direction by an imaginary line 10 meeting at right angles with a center line 7 of a tread is made into a positive direction half mode 13, and a reverse direction half mode 14 is formed in connection with the half mode 13, through which a first mode 15 is formed. A second mode 17 is formed by reversing order of the positive and the reverse half modes 13 and 14, and both the modes 15 and 17 are arranged on both sides of the center line 7 of the tread, a number of which all over a circumference of the tread are made into a positive integral one in total by providing a phase difference (l) of 1/24-5/24 times of a mode length L1. A tread groove 19 is formed in each of the sections 12 so that an area ratio between the tread groove 19 and a lug part 20 of each of the sections 12 becomes about identical with each other. With this constitution, a low noise, a low oscillation and high speed stabilized running are obtained.

Description

[Detailed description of the invention] Kibatsu F! To provide a tire that can be used for running on soft ground such as At 1m field, with the purpose of making a vehicle run smoothly and at high speed with low noise and low vibration, whether on general roads or in fields such as wet fields.

Conventionally, tires for general roads have been formed with tread patterns to prevent noise and vibration from occurring when the wheels are running, but when the vehicle is driven into agricultural fields such as wet fields, the tires may The tire ended up sinking into the wet field, and the mud and dirt got into the tread grooves, making it impossible for the tires to maintain traction on the wet field surface.

The tires would slip, making it impossible to drive in the wet fields.

On the other hand, tires for soft terrain have a trend pattern with large undulations in order to maintain the tire's rolling resistance in the field when the vehicle is running in the field.

If you drive this vehicle on a public road,
Due to the tread pattern shown above, wheel noise,
The vibrations were extremely large, making it impossible to drive this type of tire on general roads, especially at high speeds.

However, it has been impossible to use tires with conventional tread pattern 7 to drive on both general roads and soft soil in fields. BACKGROUND OF THE INVENTION When moving to a field, the vehicle is often driven on general roads, and recently there has been a desire to provide a tire that can be used for both general roads and soft ground in fields.

The present invention was devised in response to such conventional demands, and provides a soft ground that allows a vehicle to run smoothly and at high speed with low noise and low vibration on soft ground such as general roads, farm fields, sandy soil, and snowy soil. The purpose of this tire is to provide a tire that can be used for both running and driving, and its characteristics are that on the tread half of the tread center line, a plurality of virtual lines are set perpendicularly to the tread center line at intervals, and the tread center line is set at right angles to the tread center line. The pitch of the adjacent imaginary line is configured to decrease sequentially in one direction in the circumferential direction from the maximum pitch to the minimum pitch, and between the maximum pitch and the minimum pitch, the pitch of the adjacent virtual line is The group of constituent parts defined by the virtual line is set as a square beef mode, and the virtual II! are arranged at the same pitch opposite to the above to form the reverse beef cattle mode, and these two-handed modes are collectively set as the W41 mode, while on the other half of the tread, the reverse beef cattle mode and the square beef cattle mode are arranged in the same direction. These two-handed modes are successively adjacent to each other, and these two-handed modes are integrated into the island 2 mode.

The same number of the above @1 and 2nd modes are arranged as positive integers all around the circumference, and both modes are given a phase difference in the circumferential direction by 24 24 ) times the circumferential length of the 1 mode, A tread groove that opens from the tread end to the tread side wall and extends from the opening toward the trend center line is formed in each component wing, and the space between these tread grooves is a lug portion, and the lug portion of each component The point is that the area ratio of the trend grooves is approximately the same in each section.

Hereinafter, implementation of the present invention will be explained with reference to the drawings.

Figure 1iL1 shows the meridional cross-sectional shape of a tire (υ) for running on soft terrain. The trend end outer surface (6) from the center outer surface (li
1) is crowned.

The tread width (Wl) of trend (2) above is the tire width I
Approximately Q, 9 times of W,), and the center outer surface (Ws) Id,
, is (0.6±0.2) times the tread width (wl),
The semi-major axis (R1) is (1,6±028
) times the short radius (R1) of the same tire width) (0,7±
0.2) times, and the major axis (R1) is always the major axis of the minor axis (R2). Longitudinal f! The center point (6
) is on the tire radial direction line (8) perpendicular to the tread center line (7).

11! IJ right, shows a part of the tread pattern developed on the plane, and shows the tread pattern relative to the trend center line (7).
On the front side of the tread center line (7) indicated by the half surface (91, zr), a plurality of virtual! The stepwise VCj decreases linearly from the pitch (In) of the virtual line part to the minimum pitch (j6) VC, and from the maximum pitch (7n) to the minimum pitch (10), the tread center line ( 7) and the adjacent virtual 11 (10) are considered to be square beef modero, and the ai of the above adjacent pitches is:
n=2-+1 (nti positive integer), log &
It is preferable that og(n-1) Log(n-1) m(n-4) - constant, and the maximum pitch (7n) is the minimum pitch (jo) (
1.4 to 2.0) times. In the above case, the maximum pitch (7n) is 1.4 of the minimum pitch (jo).
If it is less than double, the noise of the tire (1) during running becomes large and ftp, that is, the noise level at each frequency (H2) (
dB) mutual difference becomes large, which is undesirable, and tfC,
If the above-mentioned numerical value becomes twice or more, the difference in the component @ between the maximum pitch (In) and the minimum pitch (10) becomes too large, which is undesirable as it causes uneven wear.

Also, the imaginary line portion adjacent from the 0 end of the square beef cattle mode in the same direction of the arrow as above is the same pitch (to) opposite to the above.

11...711. In), the reverse endogenous mode α4 is set, and the above-mentioned forward and reverse endogenous mode α
In Figure 1, a half mode consists of 8 pitches, that is, 1 mode consists of 6 pitches.

On the other hand, focus on tread! i! On the other half of the trend for (7) @, the circumferential direction VC # of the same arrow I is written in the opposite direction half the same rate de α
4 and the positive direction single mode (2) are sequentially adjacent to each other, and these two-handed modes α403 are integrated into 11!2 modes [171
It is said that Then, the same number of the above collection 1 and m2 modes (
to) 171 is a positive integer of 5 for the entire tread circumference, preferably
The l mode has a large number of pitches and is given as a single mode.

Each of the above constituent parts υ has an opening on the tread side IiD.

A tread groove 1191 extending from the opening toward the tread center line (7) is formed, and these tread grooves (
The area between 19 and 19 is the lug part ■, and the lug part ■ in each component @
The area ratio of the tread groove and the tread groove opening is approximately the same for each component (2).
That is, the area ratio of the lug portion (2) to the tread groove mouth in a unit area of the tread (2) is approximately the same at each portion of the tread (1). Preferably, the area ratio of the lug portion (2) to the tread (1 m1) (II) is (1,2±0.8)=1.

The tread #I (111) has a tread end fllj (211) in the tread end (4) region which is substantially straight in the longitudinal direction, and whose center is substantially orthogonal to the tread center line (7). Tread center of end groove surface*
(7) From the lit end, on the tread half surface 191, a bending groove (2) which curves convexly in a plan view in the circumferential direction opposite to the arrow l is extended, and on the other half of the tread (2), the bending groove (2) extends in the circumferential direction opposite to the arrow l. Similarly, bend #I@ is extended, and the width of each bend groove ■ on the tread center line (7) side gradually decreases approximately linearly toward the tread center line (7). It has a triangular head shape.

Tread #1 (Tread centerline l which is the groove apex of #11)
l1l#I end] L Located on the tentative line center line @ of the center of both imaginary lines ω in the component (2) of the tread groove α-.

Moreover, it is located in front of the tread center line (7). Also,
In the tread half surface 191, the center between the imaginary lines 1I71
Trend end #l (at the circumferential position of arrow l from a141)
The dimension ratio between the forward direction groove width (%V4) to the edge of the imaginary line and the reverse direction groove width (hi) in the swing direction from the center line between the imaginary lines is approximately l
: (l, 16 to IJ6), and the sum of these forward and reverse direction groove widths (W4) (W, ), that is, the groove width of the trend end groove 0, is the component part (2) of the tread #119. The pitch is approximately 0.6 times the pitch (7) of both virtual lines. On the other hand, on the other half of the tread (2), tread grooves [ILa] are formed in the opposite circumferential direction of the arrow l from the imaginary line center line (to) in the same manner as described above.

Tread center line (7) of each trend end groove above
The ends are located at approximately the same position in the tread width direction, and from the tread center 111 (7) to approximately 0 in the tread (Wl).
．． 86 times), and the bending apex of bending #I@ is also at approximately the same position in the tread width direction.

From the tread center line (7) to the middle of the tread (Wl) approximately 0.
It is formed at a position 27 times larger.

The above tread center mass (c) is the tread center line (
7), the tread centers are formed alternately at far and near positions in the direction of the tread center, and each tread center lit @ groove end (c) at the far position and each tread center line 111 #l end @ at the near position are respectively tread width. The tread center lll111 edge (C) near the tread center is located at a position approximately (0.04 to 0.16) times the tread center line (Ws) from the tread center line (7). , the center of the tread at the far position * the edge of the gutter (c) is
Focus on tread! ! From (7) to (
0,12~Oj! 5>> times the dimension position.

The lug portion I of the tread groove facing the tread center line (7) is continuous along the tread circumferential direction, and trend #11! An annular groove ■ spaced apart from i is formed. In the figure, the tread center line 11# of the tread ##- is alternately opposed to the tread center line (7) in the trend circumferential direction.
It is preferable that the annular groove (c) is formed in a zigzag shape so as to bypass the llIC23, and the runout (W-) of this zigzag shape is approximately 0.1 times that of the tread (WX), and the same pitch is , preferably have substantially equal lengths corresponding to the pitches forming the tread pattern. 1'f
ic, the groove width (Wl) of this annular #I (end) is (0ρ2 to 0.05) times that of the middle tread (Wl), and the groove depth is the same, ) is the trend (1/4 point in the width direction of 21) It is preferable that it is (Oj! ~ 0.6) times the tread + 1 pI (lI#!S).

5. This ring #I- may have a wave shape in which alternately inverted circular arc shapes are arranged like a conductive wire, or may be linear or plural in shape.

82(a) shows the tread groove (19) as a simplified tread pattern which is inclined with respect to the virtual line αQtC perpendicular to the tread center line (7).
) The tread groove portions in the region are substantially linear in the longitudinal direction, and the corner end grooves are formed substantially parallel to each other at a predetermined crossing angle (θl) with respect to the virtual line Qfl. The intersection angle [
(θI) is preferably 0”t’, but 0 to lO8
It may be within the range of

Figure 2 (b) is a simplified diagram showing the deformation of trend #I.
At 91 (to), the ends (c) of the tread center line am of tread #1 (19) arranged in the tread station direction are formed at the same position in the trend width direction.

Each figure in FIG. 8 (1) to (i) shows the lI'i plane in the longitudinal cross-sectional position of the trend center line, and each wT plane gradually moves from the bottom S of the trend [1] toward the opening. The groove width is widened, and the tread groove 11 near the outer surface of the puffer part
The wall surface of 1 is 20' in relation to the lug section■vertical line on the outside surface■
-40°), the groove edge angle [(θ,) is defined as the tread groove [1
The bottom surface of No. 1 is formed by an arc that is tangent to the lower end tube of both opposing Ii surfaces. In the above case, the groove edge angles f(θ,) of both opposing wall surfaces @knots do not need to be the same.

↓Specifically, the groove edge angle (θ2
) is preferably approximately 26° (Figure 8 (a), Figure 8 6))
. In addition, at the bend groove 0 position, the groove edge angle t at the concave edge when viewed from the center line between the imaginary lines (θ is the tread edge (4)
Ton is approximately 80° (Fig. 188 (c) left groove edge), and Ton is approximately 86° on the tread center M (7) side (Fig. Figure (c) Right groove edge, Figure 118 (X)).i, Tread center line of bent groove ■ (7) lIi Groove edge angle at position 11111 (#,)
is a tread # having a tread center line @ pancreatic end (c) located far from the trend center line (7) on the concave arc groove edge side
In the case of 1■, the groove edge angle (θ, ) at the tread center line (7) end position of the bent groove @ is approximately 80' on the concave arc edge side (Fig. 8 (Shu), The convex arc angle is approximately 26° at the edge of the trout (Figure 8 (i)).

FIG. 8 (j) of the kite is a cross section in the longitudinal direction of the tread groove, and the cross section 1iii is an upwardly opening U-shaped groove,
The wall surface of the trend #I#■ outside and near the surface of the lug part ■ is approximately in line with the outer surface of the lug sao.

In the above case, the bottom surface of the tread #I [19 may be a concave arc surface with tangents to both opposing wall surfaces. Moreover, the cross section of the same as above may also be triangular.

In Figure 1, the tread center in the longitudinal cross section of each tread #1! 1.G3 is the trend center line (7
), and the trend groove -〇 bottom surface (■) on the trend center line side is formed into a concave arc surface with the ml radius (R3). The radius 1 of the axle (R1) has a dimension of (86±15)a, and the concave arc surface passes through the trend center line l111#I end (■) or its vicinity (as well as in the tire radial direction @
(The center of the second radius (Rs) is determined to be approximately tangent to the arc of the second radius (R4) having the center on 81. The center of the second radius (R4) is determined as follows. That is, Approximately 0.1 of the 870 value in JIS D4202 (this bait indicates the tire width determined by IC#J when the tire is mounted on a rim equivalent to more than 70 of the tire width in the meridian section). The tread (2
An arc l:Iu of @2 radius (R4) is drawn so as to pass through the virtual point ■ which is a predetermined groove depth from the surface of
The dimension of 1!2 radius (R4) is (0,7) of the above 870 value.
~1.0) times.

The tread end (4111) of the center side sole 1iiicia is layered with a circular arc a11 according to the diameter (R4) of the above-mentioned thread 2,
An intermediate bottom iii bell extends as a convex arc surface from the center side bottom surface (support) end, and a tread end side bottom surface extends as a second concave arc surface from the intermediate bottom surface (material) end, and the tread The bottom inscription opens at the tread end (4) and the tread wall surround.

The bottom surface of the tread end side is formed with an eighth radius (Rs), and the center of the eighth radius (R8) is the tread center.
(7) and is located approximately on the line μs perpendicular to the tire radial direction line (8), and its dimensions are (0,7
~1.0) times, and the tread edge 1III bottom surface and tread side 1! The boundary with U is located at a distance from the tread end (4) by a dimension (Oj! to 0J6) times the tire cross-sectional height R3).

The bottom surface 132 of the intermediate portion is formed with a radius of ji44 (tRs), and the inner end of the bottom surface of the intermediate portion is formed with a radius of 2 radius (R4
), i.e., the center side bottom surface ■ end and the eighth radius (
RM), that is, the tread end is in contact with the bottom end of the tread, and the dimension of the fourth radius (Rs) is the second radius (R4).
(01 to 0.8) times.

In Figure 1 and Figure 11n4, the carcass (to) of tire (1) and the cord angle (θ
, ) has the following structure.

In other words, the material of trend rubber has a hardness (JIS-
A) is 60° to 66', dynamic viscoelastic properties are 20'C, l
When the loss tangent (m J ) is 0.15 or more in lOH2, the dynamic elastic wheel is 2o'Pcw or more, and the hysteresis loss is relatively large, the code angle (θ3) of the carcass trowel.

That is, the angle [ti] of the carcass cord with respect to an imaginary angle perpendicular to the tread center line (7) is from 47° to less than 52°.

Second, the material of the tread rubber is the same (ii! [55° ~
60°, dynamic viscoelastic properties at 20°C, 110) LZ loss tangent (tma) 0.15 or less, dynamic 51ii elastic modulus (E)' 15 kg/j M or less.

In addition, if the hysteresis loss is relatively small, the cord angle (#S) of the carcass is 52° or more. 67
It is said to be up to ゜.

When wL8 is made of the trend rubber material of 3182 above and a breaker age is added to the carcass □□□, the cord angle (θ3) Fi of the carcass and breaker age is from 47° to less than 62°.

In the above case, what are the materials of the carcass and breaker age?

Two strands of 840 denier nylon cord, or
Fi 12ao denier 2 wood strands or polyester cord, carcass margin 2 pukui, breaker C1
71til or 2pukui, and adjacent plies are sequentially laminated at the code angle (θs)° in the opposite direction to the virtual 1i1fi181.

Therefore, under each of the above conditions, the code angle (θJ)
Within the range, the S degree of noise is small, and outside the same range, the degree of noise is large.

Next, experimental results using the above-mentioned 4+11 tires will be shown.

<For tires with tire size 5.00-10> Number of modes: 5 Number of pitches in 1 mode: 6 Minor radius = 80M Major radius 8160 times Tire internal pressure: 1.8kg/aj Load: 260kg Generally under the above conditions When I measured the sound inside the car while driving on the road at 80 kg/h, the noise level was around 76 (dB), which is slightly lower than the noise level measured with snow tires at the same speed. There was no problem in driving the vehicle. Moreover, each frequency of the above noise (R
2) The difference in the noise level (dB) for snow tires is large, whereas the difference in uninvented tires is relatively small. The noise reduction was achieved.

In addition, in field running experiments, surface and middle layer hardness (reading 1
) are both K 25 LbS, the uninvented tire was able to run and start, which was not possible with snow tires and general ribbed tires.

In addition, in running tests on grass and sand, there was no improvement in running compared to snow tires or regular ribbed tires.

If the present invention is applied, the pitch of the first and second modes (to) αη is variously changed, and the pitch of the first mode αη is offset in the circumferential direction. The noise and vibrations generated by the machine are dispersed and averaged out.

Beneficially, low noise and vibration are achieved.

However, in view of the uninvented overall structure, the tire (1) according to the present invention is advantageous because it can be run with low noise and low vibration both on general roads and on relatively soft farmland.

[Brief explanation of drawings]

(a) is a simplified diagram showing a modified example of the tread, and (b) is a simplified diagram showing a modified example of the tread.
A simplified diagram showing another modification of the ti tread, m8 diagram (1
)～(1)Igti, Husband*II$IIK%A-A! Partial cross-sectional view corresponding to arrow a to I-I line arrow view, Fig. 8 U)
Figure 4 shows the cord angle of the carcass and breaker. i, clear diagram. (1)...tire, (2)...tread, (3)...
... Tread center outer surface, (4) ... Trend end, (
6)...Trend outer surface, virtual line, (2)...Division part, Q3...Square beef cow mode, α leak...Reverse beef cow mode, C15...1st mode, (to) ...Other half of the tread, node...2nd mode, (2)...trend side wall, 111...trend #11. CID...lug part,
■...Trend end s#I, ■...Tread center 1il
iIliiltl#熾、兾...Annular groove、骪...Wall surface @...Tread center! ! @Bottom, older sister...middle S bottom. Fermentation...trend end g4 bottom, (R1)...major axis,
(R2)...Short radius (Wl)...Tread width, (Wri...Inside the tire, (Wl)...Inside trend center outer surface, (L)...L mode circumferential length .

Claims (1)

[Claims] 1.) On the tread half surface (9) with respect to the red center line (7), a plurality of virtual 111@ are set that are orthogonal to the trend center line (7) at intervals, and are adjacent to each other in the direction of the tread station. The pitch of the above virtual 1lQo (jn* jn-1...
It * lo ) is configured to decrease sequentially in one direction in the circumferential direction from the maximum pitch (In) to the minimum pitch (lo), and this maximum pitch (jn)
to the minimum pitch C1o), the tread center line (7
) and adjacent imaginary lines (to), and the nine constituent parts υ group are assumed to be positive half modes (to), and the imaginary line surfaces adjacent in the same circumferential direction from the positive half mode 0 end are the above. Reverse same pitch (1
0 * 4......jn-1+jn), and the reverse beef mode Q4 is set, and these two-handed modes υα
On the other hand, the reverse half mode α and the forward half mode 0 are successively adjacent to each other in the same circumferential direction on the tread surface, and these two-handed modes α
4 (13 are collectively considered as the second mode plane, the same number of the above 1%, 2 modes M (171) are arranged as positive integers in all stations, and both modes (2) 6 171 are the 1 mode station direction Length Ll)'$!4-24
) is given a phase difference in the local direction, and each component υ has an opening from the tread end (4) to the tread side wall [stock] and from the opening to the tread center! A tread groove extending toward i (7) is formed, and the area between these tread grooves is defined as a puffer part ■, and the area ratio of the lug part ■ and the tread width α in each component (2) is equal to that of each component (■). A tire for running on soft terrain, characterized by being substantially the same.