JPS60183205A - Wheel with pneumatic tire including rugs - Google Patents

Abstract

PURPOSE:To suppress vibrations so as to improve riding comfort by respectively specifying the hardness of a sidewall section and a tread section of the tire proper of a pneumatic tire including rugs so that the difference in the hardness between those two sections is at or above a prescribed level. CONSTITUTION:A pneumatic tire of a rice planter has a tire proper 29 consisting of a bead section 33 with a pair of beads 12 integrated in its right and left sides, a sidewall section 34 and a tread section 35. Also blade rugs 30 are integratedly formed on the external periphery of the tread section 35 in its peripheral direction at an interval to form a number of rugs 31 planted between the blade rugs 30. Whereas the tire is so formed as to keep the hardness of right and left sidewalls 34 at the level of 40 deg.-70 deg. while the hardness (Hd) of the tread section 35 including rugs 30 and 31 at the level of 60 deg.-95 deg., and the difference in hardness (Hd) between sections 34 and 35 at or above 10 deg.. The internal periphery of the tire proper 29 is formed into a toroidal surface by a metallic core jig.

Description

[Detailed description of the invention] TECHNICAL FIELD This invention relates to lug pneumatic tire wheels.

Lugged pneumatic tire wheels for agricultural and tracked trees are typically constructed from a combination of a lug pneumatic tire and a wheel with a rim.

Conventionally, in the production of nitrogen-inflated tires, tire members such as rubberized cord cloth layers and beads are sequentially pasted on a metal cylindrical former, and the outermost layer is further extruded with tread rubber/l! After wrapping the entire tire to form a so-called green tire, it is removed from the former, and then the green tire is placed in a vulcanizing mold and shaved into a toroidal shape using a bladder, etc., and heated and pressurized. It was then vulcanized and made into a finished tire.

By the way, the tread surface of a completed tire has a tread pattern (uneven pattern) that has been devised in various ways in order to obtain a predetermined tire performance.

For this reason, the thickness of the tread varies depending on its pattern.

On the other hand, the extruded tread rubber layer used in green tire molding does not have a uniform thickness in the longitudinal direction.
-I don't get it.

For this purpose, as shown in Figure 1, the tread surface after vulcanization (
In the tread rubber layer (3) having lugs (2) in 1), the tread rubber flows violently and its movement also affects the cord fabric layer (4), and as a result, the inner surface of the lugs (2) A concave surface (5) may be formed.

Furthermore, if the height difference between the height of the tread pad (2) and the tread surface (1) becomes extreme as shown in Fig. 2, the concave surface (5) will expose the cord fabric layer (4) at the base of the lug (2). ).

Also, while lug (2) requires a large amount of rubber, there is no need for rubber between lug (2) and lug (2), but with the conventional method, Since the tread rubber layer (3) must have a uniform thickness in the longitudinal direction, its thickness is determined according to the lug portion.

For this reason, the areas between the lugs where no rubber is needed become extremely thick as shown in FIG. 6, and as a result, the inner surface of the tread portion has a corrugated shape in the circumferential direction corresponding to the number of lugs.

For these reasons, pneumatic tires with lugs obtained by conventional general tire manufacturing methods have a tendency to increase the weight of the tire (
(due to excessive material use), resulting in high costs, as well as deterioration in straightness and field performance.

In particular, pneumatic tires for rice transplanters have webbed wings (a type of lug) to increase traction.

Furthermore, since agricultural tires such as binder and combine harvesters are so-called high-lag tires, the above-mentioned problems become more noticeable.

From this point of view, for example, there is a pneumatic tire manufactured by the method disclosed in Japanese Patent Publication No. 50-36672, which has certain advantages.

However, in this conventional example, the tread rubber layer is molded in advance as a crown shape connected in the circumferential direction of the tire, and the inner periphery of the crown-shaped tread rubber layer is mainly coated with a rubberized cord cloth layer formed separately on a former. Since the tire is obtained by deforming a raw case body consisting of a pair of nine beads into a toroidal shape and bonding them together, the tread rubber layer is inevitably unvulcanized or semi-vulcanized during manufacturing. Therefore, when the upper mold is opened and the core mold is removed, the rubber layer will adhere to the core mold, and the tread rubber layer will not remain in the mold or will be deformed even if it remains. It can become something.

Therefore, in the conventional example of Jin, it is necessary to apply chrome plating to at least all parts of the surface of the core mold that come into contact with the mold rubber, while the corresponding surface of the mold has to be specially treated by making it rough. Even with these special modifications, the tread rubber layer could remain in a deformed state within the mold, which could result in tires with irregular shapes. Furthermore, it was necessary to inflate the raw case body, which was extremely difficult to control.

In addition, as agricultural wheels, there is also a type ■ in which a solid rubber ring is fitted to the rim (publication of Utility Model Publication No. 57-18163), and a type ■ in which a rubber ring is integrally covered with a metal pipe wheel (publication of Utility Model Publication No. 57-18163).
However, these are all too heavy and difficult to manufacture.

In that respect, % Jitko Publication No. 58-36561, Publication No. 58-5
Since the agricultural wheel disclosed in Japanese Patent No. 3202 is a pneumatic tire in which a hollow tire body is attached to the rim, it is recognized that it is more advantageous than the above-mentioned types in terms of fuel consumption, material cost, and manufacturing.

However, since a hollow tire body is used, the cross-sectional shape is irregular, and a large number of gauges must be removed due to this, which has the problem of causing excessive running resistance and earth resistance when used in rice transplanters.

Further, although the sidewall portion and the tread portion need to have a difference in hardness due to their nature, they are made of the same properties, and in this respect, they are not perfect.

The present invention was devised in view of the above-mentioned circumstances.
This eliminates the conventional uuM.

1.2+1 According to the present invention, in a pneumatic tire RLV wheel with lugs formed by combining a pneumatic tire with lugs and a wheel with a rim, the tire body with lugs has a pair of left and right bead portions, a sidewall portion, and a wheel with rims. The inner circumferential surface of the tire body is a toroidal surface formed entirely of metal core-shaped elements, and a pair of left and right tread portions of the tire body are formed. The hardness of the sidewall part is 40° to 70°,
The hardness of the tread part including the puffer fish must be between 60' and 95°, and the difference in hardness between the two must be at least 10°, and the bead part of the tire body must fit into the wheel rim. The present invention provides a pneumatic tire wheel with lugs characterized by:

Note that the term "rag" as used herein is defined as a puffer fish including the blades of a pneumatic tire for a rice transplanter.

Embodiments of the present invention will be described in detail with reference to FIG. 4 and subsequent figures, but prior to this, manufacturing will be explained and then the structure of the middle wheel of the present tire will be explained in detail.

Fig. 4 and Fig. 5 show the forming process or procedure of the green tire Qf), and Fig. 4 shows a general cylindrical former-a.
On D, a pair of left and right beads (2) are wound N4, and a rubber cord cloth layer 03, which becomes an unvulcanized or uncured carcass cord layer, is wound over the beads (C). Furthermore, on the outer circumferential side of the cord cloth layer 03, a rubberized cord layer (1
3B) is wrapped around the tire, and a rubber sheet 01 made of only unvulcanized or semi-vulcanized rubber is attached to prevent the cord from being disturbed during vulcanization molding, which will be described later. It is molded separately.The cord layer (1
313) can be omitted.

In the example of FIG. 5, a pair of left and right beads Oz, unvulcanized or A cord cloth layer o3 (13n) with semi-vulcanized rubber is sequentially wrapped and attached, and on top of that a green tire OQ with a rubber sheath made of only unvulcanized or semi-vulcanized rubber (I) is installed. molded.

Here, the stretchable element a9 is composed of a first mold (15A) and a second mold (15(1)) which is attached to the first mold (15A) so as to be able to fix the nuphid thereon via a cotter (15)1), and its outer circumferential surface shape is has a shape that follows the inner surface shape of the tire body.

In addition, the cord of the cord cloth layer Q3 (13F) may be made of stretched nylon, polyester, rayon, other synthetic or man-made fibers, or natural fibers, as well as metal materials such as steel and aluminum. It may be a composite material, or may be a monofilament, a tape, a cage-like material, or a thick-edged material, and an unvulcanized or semi-vulcanized topping rubber is provided on the cord.

When the cord cloth layer θ3 has a radial structure, the carcass cord angle is 90' in the circumferential direction.
20', and when the carcass cord is made into a four-way construction with bias stroke, the carcass cord angle is set to 15° to 50° with respect to the circumferential direction. In the case of a bias structure, a plurality of even number sheets (2 to 8 sheets) are pasted alternately.

In addition, when the belt cord layer (13) 1) has the aforementioned radial structure, the belt cord angle is 00 to 30 in the circumferential direction.
', and when the carcass has the aforementioned bias structure,
The angle is 5° to 60° lower than this angle.

Also, Gomshi) Q41 is a band-shaped one,
Cord cloth # (13B) is provided around it and is not shown, but it constitutes part or all of the rubber material of the tire body, such as abrasion gum strips and sidewall rubber, and has a carcass part here. Tire (IQ is formed.

The green tire 0Q formed or molded according to the method described above is mounted on a tire manufacturing machine shown in FIGS. 6 and 7.

The tire manufacturing machine is composed of at least five mold parts that can match, namely an upper mold element Q61, a lower mold element 0 force, and a core mold element 0&; in this example, the lower mold element θ7) is fixed, and Relatively, the lower mold element (171) and the core mold element (to) can be raised and lowered freely, and the upper and lower mold elements OGOη can be clamped and opened.

When the molds are matched, the cavity a9 having the outer shape of the pneumatic tire with lugs to be manufactured is formed into a configuration opening.
In this embodiment, lug molding portions indicated by large protruding blades extending from the sidewall portion to the tread portion are formed at predetermined intervals in the circumferential direction on the upper and lower mold elements 08θ, and furthermore, the lug molding portion copper amount includes a plurality of lug molding portions. Trapezoidal lug forming portions Qυ are formed at predetermined intervals in the circumferential direction. Note that in some cases, the molded portion aD is not necessary.

A cylinder (not shown) is attached to the annular rim (a) of the core-shaped element α&, so that it can be raised and lowered freely, and a bolt (
The first type (c) is installed through the first type ■jc
@', 2 m (c) is a split mold made of metal ('A4, aluminum, etc.) that can be freely slid and fixed via a kotsuta (to), and the 1st type ■ and the 2nd type ( When the molds of c) are matched, the inner surface shape of the toroidal tire body is formed. Note that this core mold element 08 is a core mold element 0 for green tire molding.
9 can also be used as is.

In this example, the shape is such that a part of the outer surface thickness of the core-type element W tread gauge and side gauge is subtracted, and the subtracted gauge is supplemented by rubber described later.

Thus, a separately molded green tire 110 is mounted on the core mold element 08 via a tire mounting machine, and the lug molding portion of this core mold element (18Th @ lower mold element o'1 as shown in Figure 6) It is charged according to the gradient.

Moreover, an annular slug, that is, an unvulcanized rubber slug, which constitutes a part of the puffer and tread portion is attached to the mating surface of the lower mold element Uη.

Therefore, this rubber @ has a capacity at least equivalent to the lug volume, and as shown in Fig. 7, the upper mold element (
17) As the mold clamping causes the cavity o9 to be filled with fluid, 1L of unvulcanized cord cloth layer 0 due to this flow resistance.
The disorder of the cord in 3 (1311) is caused by the rubber sheet α4.
This will be prevented by

Further, when the cord cloth layer u3 (13n) is semi-vulcanized (it may be unvulcanized), its rubber quality can be different from that of the tread, lugs, and tire body.

Then, this rubber (2) is flowed inward in the radial direction, adhesively integrated with the green tire αQ, and heated and vulcanized to complete a specified tire.

In addition, when a block shape is used as the rubber wire, the cross section thereof may be of any shape such as circular, rectangular, or square, and may be arranged at predetermined intervals in the circumferential direction depending on the case.

Further, the rubber tube may be of a type in which a rubber injection port shown in FIG. 7 is formed and rubber is injected from this port by injection or the like to fill the cavity a9. In this case, A plurality of cavities α9 and rubber injection ports are connected radially, and an air vent is formed.

In this example, the blade lugs (7
) and trapezoidal puffer C3υ are vulcanized and molded, and after going through processes such as opening the mold and disassembling the core mold elements, they are moved to the next inspection process etc. by a tire take-out machine (unloader, etc.). That will happen.

Note that when the semi-vulcanized cord cloth layer Q3 (13B) described above is used for producing a green tire, it is not necessary to use the rubber sheet α.

That is, since it is semi-vulcanized, the cord cloth layer (13(
This is because there is no possibility of chord disturbance or directional disturbance of the chord angle occurring in 13s0.

Referring to FIGS. 8 to 15, wheels in which various pneumatic wheels (2) according to the present invention manufactured in the above-mentioned examples are fitted to the wheel rims are illustrated, and the 8th From the figure, Fig. 12 mainly shows pneumatic tires for rice transplanters, Fig. 13 shows pneumatic tires for agricultural use, mainly in the form of a high puffer, used for binders, combines, harvesters, etc., and Fig. 14 (1) (21) These are pneumatic tires that are mainly used as rear wheels for agricultural purposes and tracked trees, and Figures 15 (1) and 15 (2) show pneumatic tires that are used as paddy field wheels for power tillers.

In any of the embodiments, the tire body has a bead section in which a pair of left and right beads (2) are embedded, a sidewall section (end), and a tread that is connected to the sidewall section via a shoulder. There are 0 lugs on the outer circumferential side of the tread part (to) at intervals of IJJ in the circumferential direction]
) are integrally formed to protrude, and the blade lugs (to) are integrally formed to protrude from the tread portion to the sidewall portion (b) in FIGS. 8 to 12 (in the case shown). .

Historically, the inner peripheral surface of the tire body (support) is a toroidal surface (29
A), where the gauge of the tire body is uniform throughout.

It's amazing, it's wrapped around Vidro Z and the tire itself is t2! , e, the carcass cord layer 03 has a radial structure with a cord angle as described above or a bias groove structure, and in either case, the cord terminal (13
Even in the so-called center overlap type, in which the terminals A) overlap each other in the tread part and are located on the side of the tread part, the terminals
3A) is the blade lug (1) in the sidewall part (b).
It may be located at the base of the
As shown in 1), the cord terminal (13A) may be housed in the rim hood (36A) of the rim (G), and the point is that the cord terminal (13A ), and it is desirable to prevent cracks from that terminal (13h) as much as possible.

t&, the cord angle of the belt cord layer (1311) provided around the tread portion-9 on the outer peripheral side of the carcass cord layer 03 is the groove structure as described above. The belt width of this belt cord layer (i3B) is set to span the right shoulder portion of the chisel.

In addition, as mentioned above, it is desirable that the rubber that constitutes the tire body and the rubber that constitutes the tire tread have different rubber properties due to their functions. For example, the hardness of the rubber of a green tire, especially The hardness (ffl) of the pair of left and right sidewall parts is JISA 40° to 70°, preferably 45° to 65°, and the hardness (fact) of the tread (end) part including the lug cyjc+υ is JISA/, υ0
~95°, preferably 70''~9D0, and whichever range is selected, the difference in hardness between the two should be 10° or more.

Here, it is after vulcanization to a hardness of t.

That is, when the driving wheels of a riding rice transplanter were equipped with pneumatic tire wheels with lugs marked F 1 to 12, traction force and vibration tests were conducted, and the traction force results shown in Fig. 17 (1) were conducted. , - The imaging results shown in FIG. 17 (2) were obtained.

This test result also makes clear the significance of the hardness described above.

Therefore, for the rice transplanters shown in Figures 8 to 12, the blade lugs require considerable rigidity to obtain traction, while the sidewalls are flexible from the standpoint of vibration absorption. Although elasticity is required, it is desirable to simply change the rubber quality between the tire body and the lug portion (which may or may not include part of the red part and part of the sidewall part). can be made into tires.

Also, even in the case of the high-lug type shown in FIGS. 13 to 15,
It is possible to provide rigidity and wear resistance to the lug portion. Furthermore, when the rubber sheet A41 is used, its physical properties can be the same as or different from those of the rubber gradient or the diamond body.

Although FIG. 10 shows a so-called single-blade type and FIG. 11 shows an inner-blade type, the tires of each embodiment according to the present invention are wheels (A) consisting of spokes (A) and a rim 9.
For example, as shown in FIG. 14, air is injected into the tube (7) through a valve (7). In this case, it may be a tube (7).

Figure 16 (shape of the lug with reference to 11 (21 (3)))
I will explain about the stock purchase.

Fig. 16 (1) (2+
) and lugs (small lugs) 0υ arranged with a lug gap (8) between the blade lugs 01.

The vane lug body) is for obtaining buoyancy and traction, and is formed from the surface of the tread part (to) to approximately the middle of the outer surface of the sidewall part C+, and has a height of 0υ.
For example, the height is half the width of the tire body,
The width is set to 2.5 times the width of the tire body, and the inclination angle (to the tire radial center line (P)) is set to 30 degrees.

It is for obtaining traction force, and is formed on the surface of the tread in the shape of a substantially hexagonal truncated pyramid block. Because this small lug c11) is approximately in the shape of a hexagonal truncated pyramid, the tre/nod surface and the small lug (3υ
The space (α) formed by the vane lug (1) is wide-angled (widening toward the end) and is located radially outward from the tread surface and outward from the left and right axes from the tread center.

A small lug C (point IA is formed approximately at the center in the width direction on the leading side of υ in the rotational direction (N)), and serves to cut through the mud when the small lug clυ is pulled out of the mud. small rug O
The leading side of D by forming a tip.

It holds less mud than a flat surface, and the traction force is slightly lower, but it also reduces mud lifting and adhesion, and even if mud adheres, when the mud is pressed during the next rotation, the tip ( 31A), and an increase in adhering soil that would fill the space (α) is prevented.

The apex angle ψ) of the pointed end (31 mm) is preferably in the range of 80 to 170° as shown in FIG. 1
If it is larger than 70°, it will be difficult to remove the adhered mud, and the angle will be 80°.
If it becomes smaller, there will be a loss in traction force.

On the surface of the tread portion (end) of the tire main body 4, there is a raised portion (35A) that is pointed in the radially outward direction at the tread center.
is formed and is continuous with the pointed end (31A). The raised portions (35A) have a mountain-shaped cross section, are formed between the small lugs 6υ and between the small lugs 6υ and the feather puffer (1), and are lower than these.

Next, the tread pattern will be explained.

The tread pattern of the tire (to) is based on the basic requirement of ensuring the required wet field performance, and in consideration of the tire outer diameter and allowable load, there are 8 to 10 blade lugs (7) between each blade puffer part. The small lag 0υ is set within the range of 1 to 5.

In addition, in order to increase the strength when attaching the vane lug (1) to the tire body, the rigidity of that part is set higher than the small lug 0), but the vane lug (1) and its rear side in the rotational direction are , that is, by making the lug gap (S4) between the trailing side small lug 0] larger than the other lug gaps (8+ to 8.), the deflection under load is reduced compared to the case of the same spacing. The amount increases and approaches the amount of deflection of the small lug 0]), reducing the vibration energy and lowering the maximum value of the impact force.

In addition, the circumferential length of the ground contact surface of the feathered puffer fish (1) is a small lug 6]
), even if the lug gap (84) is increased, the lug pitch (R4) can be made the same as any of the other lug pitches (R+ -Rs).

In addition, to the above-mentioned structure shown in FIG. 16 (1) (21 (3)), a belt cord layer (1
3B), and the entire inner circumferential surface of the tire body is a toroidal surface (29A) shaped with a metal core-type element.
) is of course true.

In summary, in the pneumatic tire wheel with lugs of the present invention, the tire body having lugs is composed of a pair of left and right bead portions, a sidewall portion, and a tread portion continuous to the sidewall portions, and the inner circumferential surface of the tire body The entire tire has a toroidal surface shaped with metal core-type elements, and historically, the hardness (Ild) of the pair of left and right sidewalls of the tire body is said to be between 40° and 70°, including blowfish. The hardness (lid) of the tread is said to be 60° to 95°, and the difference in hardness between the two is 10° or more, and since the bead of the tire body is attached to the wheel rim, the following There are advantages.

Since the tire body is a hollow tire, it has the advantages of a general hollow tire in that it is simpler and lighter in structure than solid tires or tires made of metal pipes, but it also has a cord layer surrounding the tire body. Because of this, it is possible to increase the rigidity and improve the puncture resistance.

Furthermore, since the entire inner peripheral surface of the tire body is a toroidal surface shaped with metal core-shaped elements, the gauge is uniform throughout the tire body, and there are no irregularities compared to a shaped surface with a bladder. Therefore, in conjunction with the cord layer, the gauge of the tire body can be made as thin as possible,
Here, the paddy field performance can be improved, and moreover, a large traction force can be obtained.

In addition, the hardness of the sidewall part of the tire body is 40° to 70°, and the hardness of the tread part including the lugs is 60°.
95°, and the difference in hardness between the two is said to be more than 10°, so the traction performance is good, and vibrations can be suppressed even though they are laggy. Since it has a toroidal surface shaped by the metal core-shaped element described above, it becomes a uniform tire, and when this is fitted onto a rim to form a wheel, rotational resistance is reduced and straight-line performance can be improved.

[Brief explanation of drawings]

FIGS. 1 to 3 are explanatory diagrams of a tread portion showing a conventional example,
FIG. 4 is an explanatory diagram of the first example of green tire molding in the production of the tire of the present invention, and FIG. 5 is a sectional view of the main parts of the second example.
FIG. 6 is a sectional view of the main parts of a manufacturing machine for manufacturing the tire of the present invention;
The ISZ diagram is also a cross-sectional view of the type A: +”a state, No. 8 is a cross-sectional view of the first example of implementation, No. 1 is a wooden complete light tie, Fig. 9 is a front view with the same part omitted, and Fig. 10. FIG. 11 is a partially omitted side lj diagram with a different lug shape from FIG. Figure 14 (1) (2) is a re-map of the city shown with tractor tires and a developed plan view, Figure 15 (1)
(2) is a cross-sectional view and a developed plan view for the seat turning machine, No. 16
Figure 11(2+(3) is a detailed partial front view and partially enlarged plan view of the lug shape, and Figure 11(2) shows the results of the traction test and vibration test of the center shaft of the present invention. It is a graph.

Claims (1)

[Claims] 1. A pneumatic tire wheel with lugs formed by combining a pneumatic tire with lugs and a wheel with a rim. The tire body having lugs is composed of a pair of left and right bead parts, a sidewall part; 112, and a tread part connected to the sidewall parts. The inner circumferential surface of the tire body is a rhoidal surface (the entire inner peripheral surface is shaped with metal UW core-shaped elements), and historically, the hard J of the pair of left and right sidewalls of the tire body.
5 (lkl) is 40° to 70°, the hardness of the tread portion including the lugs (1:1.d) is 600 to 95°, and the difference in hardness between the two is 10° or more. Then, the bead of the tire body fits into the wheel rim.
A pneumatic tire R1 with lugs, which is characterized by a wheel.