JP3569449B2 - Tires with lugs - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a tire having a lug, and more specifically, to a lug as a wheel-type traveling device of a traveling machine body (an agricultural work machine such as a tractor, a binder, a tiller, or a construction work machine such as a wheel loader). The present invention relates to a pneumatic tire having the same.
[0002]
[Prior art]
2. Description of the Related Art Tires in which lugs are arranged at intervals in a circumferential direction on a tread portion are employed in a wheel-type traveling device of an agricultural work machine such as a tractor, a binder, a tiller, or a construction work machine such as a wheel loader.
This lug tire is different from an automobile or the like in terms of work form, and is usually designed from the viewpoint of placing more emphasis on traction, mud drainage, and the like than on running performance.
[0003]
[Problems to be solved by the invention]
Since the conventional lug tire emphasizes work forms such as traction force and mud discharging property, when traveling on the road (generally 20 to 30 km / H), the natural vibration of the traveling body (engine vibration, traveling vibration, etc.) The vibration inherent in running) and the lug frequency of the lug tire (frequency associated with the variation of the lug grounding form due to the rotation of the tire) are synchronized (referred to as resonance and resonance), and large vibration or noise (whole body vibration of the operator, Local vibrations (hand-arm vibrations), referred to by the Japan Society of Agricultural Machinery, Handbook of Biological Production Machines published by Corona, pages 304 to 307) are generated, and the riding comfort is deteriorated, and the body or work is performed. There is a problem that it also affects the durability of the part.
[0004]
In view of the above situation, the present invention provides a lug capable of reducing vibration or noise during road running without sacrificing traction performance or the like by changing the pitch of the lug (pitch variation). It is an object to provide a tire having the same.
[0005]
[Means for Solving the Problems]
The present invention has taken the following measures to achieve the above object. That is, a feature of the first aspect of the present invention is that in a tire having lugs arranged in a protruding manner at circumferential intervals on a tread portion as a wheel-type traveling device of a traveling body, , together are arranged at an equal pitch to substantially regular intervals in the circumferential direction of the gap, the second ground portion is an oblique direction to a position from the first ground portion located equator side of the tread portion to the right and left shoulder portions of the tread portion , And the first ground contact portion is pitch-varied in a pattern that cancels or attenuates the natural vibration of the traveling body.
[0006]
Here, the traveling body refers to an agricultural work machine such as a tractor or a binder or a construction work machine such as a wheel loader or a front loader, and the tire according to the present invention is mounted as a driving tire of a wheel-type traveling device of the traveling body. When the vehicle travels at a speed of 20 to 30 km / H on the road, the natural vibration of the traveling body and the lag frequency are rarely synchronized (resonance, resonance), and the whole body vibration of the operator is reduced. Local vibrations are reduced, driving fatigue and the like are prevented, and riding comfort is improved.
[0007]
Further, a feature of the second aspect of the present invention is that in a tire having lugs arranged in a protruding manner at circumferential intervals on a tread portion as a wheel-type traveling device of a traveling body, the lugs are: the circumferential spacing with are arranged at an equal pitch to substantially equal pitch, the second ground portion located on the left and right shoulder portions of the tread portion minutes first grounding portion located on the equator side of the tread portion in the diagonal direction The second ground contact portion is extended alternately in the left and right directions, and the second ground contact portion is pitch-varied in a pattern that cancels or attenuates the natural vibration of the traveling body.
[0008]
Further, a feature of the third aspect of the present invention is that in a tire having lugs arranged in a protruding manner at circumferential intervals on a tread portion as a wheel-type traveling device of a traveling body, the lugs are: the circumferential spacing with are arranged at an equal pitch to substantially equal pitch, the second ground portion located on the left and right shoulder portions of the tread portion minutes first grounding portion located on the equator side of the tread portion in the diagonal direction The first and second ground contact portions are alternately extended left and right, and the first and second ground contact portions are pitch-varied in a pattern that cancels or attenuates the natural vibration of the traveling body.
[0009]
It is preferable that the variation of the pitch of the first ground contact portion is configured by changing a circumferential length of the ground contact portion by forming a tapered portion at a stepping tip portion of the ground contact portion.
[0010]
It is preferable that the variation of the pitch of the second ground portion is configured by changing a circumferential length of the ground portion by forming a tapered portion at an end of the ground portion .
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 2 is an external perspective view of a lug tire 1 used for a driving wheel in a wheel-type traveling device of a traveling body (not shown) such as a tractor and a binder, and FIG. 1 shows a part of a tread portion thereof. .
[0012]
1 and 2, a tread portion 2 of a tire (pneumatic) 1 has lugs 3 which are arranged so as to protrude at circumferential intervals.
The arrangement (lag pattern) of the lugs 3 is a pattern for canceling or attenuating the natural vibration of the traveling body.
Specifically, as shown in FIG. 1, the lugs 3 are arranged at equal or substantially equal pitches in the circumferential direction B, and are located on the equator XX side of the tread portion 2. The second ground contact portions 3B located on the left and right shoulder portions 4 of the tread portion 2 extend alternately left and right in an oblique direction from the 1 ground contact portion 3A, and the length of the first ground contact portion 3A or / and the stepping tip of the portion 3A By forming a tapered portion in the portion, pitch variation P1, P2, P3 is configured.
[0013]
In FIG.
P1 = B-a1 + a2
P2 = B-a2 + a3
_{P1-P2 = (- a n} + a1) + a1-a2 = 2a1- (a 2 + a n)
_{∴P n-1 -P n = 2P} n-1 - (a n + a n-2)
The pitch variation is achieved by changing the length a of the tapered portion of the first ground portion 3A and changing the lengths b1 and b2 of the portion 3A.
[0014]
FIGS. 3 and 4 show a variation in pitch by forming a tapered portion 103A having a height H1 and a length L1 at the leading end of the first ground contact portion 3A. The intervals B are arranged at equal pitches or substantially equal pitches, and the second ground contact portions located on the right and left shoulder portions 4 of the tread portion 2 from the first contact portion 3A located on the equator XX side of the tread portion 2 The tape is extended alternately left and right in a diagonal direction, and is formed as a pitch variation by forming a tapered portion at the length of the second ground portion 3B and / or at the end of the portion 3B. As shown in FIG. 5, a pitch variation is made by forming a tapered portion 103B having a height H2 and a length L2 at the end of the second ground contact portion 3B, thereby changing the pitch of the tapered portion. Tuning the dynamic and the lug frequency (resonance, resonance) is What is counteract or attenuate.
[0015]
FIG. 6 shows a pitch variation by providing an intermediate spacer portion C having a predetermined width between molding portions of lugs 3 in a mold (mold) for vulcanizing and molding the tire 1 and changing the length of the intermediate spacer portion C. It is a thing.
That is, in the mold, the basic form of the lug forming part is kept as it is, and the length, the height, the end length and the height of the stepped part are partially modified or the spacer part C is inserted so that the metal is changed. It is possible to vulcanize a low-vibration rug tire without increasing the mold allowance.
[0016]
FIG. 7 shows a fourth embodiment of the present invention, in which the shapes of the lugs 3 arranged in a zigzag pattern on the left and right sides of the equator XX are symmetrical, that is, when L3 = L4, L3 ′ = L4 ′. The pitch variation is obtained by changing the lug pitch P in the circumferential direction, and when L3 ≠ L4, L3 ′ ≠ L4 ′, by making the shape of the lug 3 large and small on the left and right. Can also cancel or attenuate the tuning between the natural vibration of the traveling vehicle and the lag frequency.
[0017]
8 and 9 show fifth and sixth embodiments of the present invention. FIG. 8 shows that the length a of the tapered portion of the first ground portion 3A is a1 <a2 when a1 = a3 and a2 = a4. In addition, the length b of the portion 3A is pitch-varied as b1 = b2 = b3 = b4, and FIG. 9 shows the length a of the tapered portion of the first ground portion 3A as a1 = a2 = a3 = In addition to a4, the length b of the first grounded portion 3A is set to b1> b2, b3> b4, and b1 = b3, b2 = b4, thereby providing pitch variation.
[0018]
In each of the above embodiments, the cross-sectional shape of the lug 3 is substantially trapezoidal, and the equatorial portion of the first grounding portion 3A of the lug 3 is indicated by reference numeral 3A1 in FIGS. It is considered that the side slip prevention and the mud brushing are good by forming them almost in parallel.
[0019]
【The invention's effect】
As described in detail above, according to the present invention, it is possible to provide a low-vibration lug tire without sacrificing traction or the like.
[Brief description of the drawings]
FIG. 1 is a partial plan view showing a first embodiment of the present invention.
FIG. 2 is an overall perspective view showing the first embodiment of the present invention.
FIG. 3 is a partial plan view showing a second embodiment of the present invention.
FIG. 4 is a perspective view of a main part of FIG. 3;
FIG. 5 is a perspective view of a main part showing another example of FIG. 3;
FIG. 6 is a partial plan view of a mold showing a third embodiment of the present invention.
FIG. 7 is a partial plan view showing a fourth embodiment of the present invention.
FIG. 8 is a partial plan view showing a fifth embodiment of the present invention.
FIG. 9 is a partial plan view showing a sixth embodiment of the present invention.
[Explanation of symbols]
1 tire 2 tread 3 lug

Claims (5)

A tire having a lug (3) which is arranged so as to protrude with a circumferential interval on a tread portion (2) as a wheel-type traveling device of a traveling vehicle,
It said lug (3) is, the circumferential interval (B) together are arranged at an equal pitch to substantially equal pitch, first tread from the ground portion (3A) located on the equator side of the tread portion (2) The second ground contact portions (3B) located on the left and right shoulder portions (4) of the portion (2) are alternately extended in the diagonal left and right directions,
Tires having the first ground portion (3A) has lugs you characterized in that it is the pitch variation of (P1 to P3) in a pattern that canceling or Metsu衰the natural vibration of the vehicle body. In a tire having lugs arranged in a protruding manner with a circumferential interval on a tread portion as a wheel-type traveling device of a traveling aircraft,
The lug, the circumferential spacing (B) is together are arranged at an equal pitch to substantially equal pitch, first located on the left and right shoulder portions of the tread portion minutes first grounding portion located on the equator side of the tread portion 2 The grounding portion is extended alternately left and right in an oblique direction,
Tire having the second ground portion, lug you characterized in that it is the pitch variation of a pattern of canceling or Metsu衰the natural vibration of the vehicle body. In a tire having lugs arranged in a protruding manner with a circumferential interval on a tread portion as a wheel-type traveling device of a traveling aircraft,
The lug, the circumferential spacing (B) is together are arranged at an equal pitch to substantially equal pitch, first located on the left and right shoulder portions of the tread portion minutes first grounding portion located on the equator side of the tread portion 2 The grounding portion is extended alternately left and right in an oblique direction,
Tire having a lug you characterized in that it is the pitch variation of the pattern of the first and second ground portions, to canceling or Metsu衰the natural vibration of the vehicle body. 2. The method according to claim 1, wherein the variation of the pitch of the first contact portion is configured by changing a circumferential length of the contact portion by forming a tapered portion at a leading end of the contact portion of the contact portion. Or a tire having the lug according to 3. The pitch variation of the second contact portion is configured by changing a circumferential length of the contact portion by forming a tapered portion at an end of the contact portion. A tire having the lug according to 3.

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