JP2007145124A - Elastic wheel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an elastic wheel capable of improving the durability of a damper member over a long period. <P>SOLUTION: This elastic wheel 5 has a rim extending in the circumferential direction capable of supporting a tire, a disc fixed to an axle, and a damper member 5 constituted of an elastic body which extends in the circumferential direction and connects between the rim and the disc. The damper member 5 includes a body 5A formed out of fiber reinforced rubber which is reinforced by fiber and a covering part 5B which is integrally bonded to the outer circumferential surface 5Ao of the body 5A and protects the body 5A by covering at least 50% of the body 5A. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an elastic wheel capable of improving durability.

  FIG. 12 shows a cross-sectional view of a conventional elastic wheel r. The elastic wheel r includes a rim a that can support a tire and extends in the circumferential direction, a substantially disk-like disk b that is fixed to an axle, and a damper member c that is formed of a ring-like elastic rubber that connects these. (For example, see Patent Document 1 below). In such an elastic wheel r, the vibration of the rim a during traveling is absorbed by the damper member c, so that the amount of vibration transmitted to the disk b and the axle (not shown) is reduced. Therefore, riding comfort and noise performance in the passenger compartment are improved.

JP 2005-96642 A

  However, in the conventional elastic wheel r, the damper member c always receives heat from a brake device (not shown). Therefore, there is a problem that the physical properties of the damper member c change due to this heat and the sufficient performance cannot be exhibited, or the outer peripheral surface of the damper member c is damaged early, and cracks are likely to occur. Further, the outer peripheral surface of the damper member c may be damaged by contact with foreign matters during traveling, and is directly exposed to energy such as ultraviolet rays and ozone. For this reason, there existed a problem that deterioration and destruction were easy to occur. In addition, oils and fats around the vehicle suspension may adhere to the damper member c and cause swelling and the like.

  Further, the conventional damper member c is made of only a rubber composition. Therefore, in order to suppress the elongation in the circumferential direction, it is necessary to increase the rubber hardness. However, in this case, the rigidity of the entire rubber is increased, and the shock absorption tends to be lowered and the riding comfort tends to be deteriorated.

  The present invention has been devised in view of the above problems, and covers the damper member by covering a main body made of fiber-reinforced rubber reinforced with fibers and at least 50% of the outer peripheral surface of the main body. The main object is to provide an elastic wheel that can improve the durability of the damper member over a long period of time, based on the structure including the covering portion that protects the main body.

  Still another object of the present invention is to improve steering stability without impairing riding comfort in this type of elastic wheel.

  The invention according to claim 1 of the present invention comprises a rim extending in the circumferential direction capable of supporting a tire, a substantially disk-shaped disk fixed to an axle, a ring extending in the circumferential direction, and the rim and the An elastic wheel having a damper member made of an elastic body connecting between the disk and the damper member, wherein the damper member is integrally bonded to a main body made of fiber reinforced rubber reinforced with fibers and an outer peripheral surface of the main body. And a covering portion that protects the main body by covering at least 50% thereof.

  The invention according to claim 2 is the elastic wheel according to claim 1, wherein the covering portion is made of rubber or elastomer and covers the entire outer peripheral surface of the main body.

  According to a third aspect of the present invention, the covering portion is made of butyl rubber, halogenated butyl rubber, hydrogen-added diene rubber, hydrogen-free diene rubber, ethylene propylene rubber, ethylene propylene diene rubber, or chlorosulfonated polyethylene rubber. 2. The elastic wheel according to claim 1, comprising at least one of chloroprene rubber, fluororubber, acrylic rubber, silicone rubber, chlorinated polyethylene or a copolymer of brominated paramethylstyrene and isobutylene.

  According to a fourth aspect of the present invention, the covering portion includes a dynamically crosslinked rubber, a dynamically crosslinked polyolefin, a polyurethane, a styrene-butadiene-styrene copolymer, a styrene-isoprene-styrene copolymer, and a styrene-isobutylene- The elastic wheel according to claim 1, which is a styrene copolymer or a hydrogen compound of any one of the above copolymers.

According to a fifth aspect of the present invention, the covering portion has a conductivity having a volume resistivity of 1 × 10 ⁸ (Ω · cm) or less, and contacts both the rim and the disk. It is an elastic wheel in any one of.

  The invention according to claim 6 is the elastic wheel according to any one of claims 1 to 5, wherein the covering portion has a thickness of 0.1 to 5.0 mm.

  In the invention according to claim 7, the ratio of the initial elongation at break EB1 to the elongation at break EB2 after aging at 160 ° C. for 5 days (EB2 / EB1) is 0.70 or more. The elastic wheel according to any one of claims 1 to 6, which has heat resistance.

  In the elastic wheel of the present invention, the damper member includes a main body and a covering portion that covers the outer peripheral surface thereof. The main body is made of fiber reinforced rubber reinforced with fibers, and substantially determines the strength, tensile rigidity, and the like of the damper member. Then, by appropriately setting the orientation direction of the fibers, the circumferential rigidity and the like can be easily increased without impairing the riding comfort. Moreover, since 50% or more of the outer peripheral surface is covered with the covering portion, the main body is protected from collision of foreign matter, ozone, and ultraviolet rays. In other words, the body is protected at the expense of the covering. Therefore, the performance of the damper member (main body) is maintained over a long period of time, and the durability of the elastic wheel is improved.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
1 is a cross-sectional view of an elastic wheel equipped with a pneumatic tire, FIG. 2 is an enlarged view of a main part of the elastic wheel, and FIG. 3 is an end view taken along line AA of FIG.

  The elastic wheel 1 of the present embodiment includes a rim 3 that can support a pneumatic tire (hereinafter, simply referred to as “tire”) 2, a disk 4 that is fixed to an axle (not shown), and a ring that extends in the circumferential direction. And a damper member 5 made of an elastic body that elastically connects the rim 3 and the disk 4 to each other.

  As the tire 2, for example, a radial tire for a toroidal passenger car having a pair of bead portions 2a and 2a seated on a rim 3 is shown.

  The rim 3 is a pair of rim seat portions 3a, 3a on which the bead portion 2a of the tire 2 is seated, and an outer end portion of the rim of each rim seat portion 3a in the rotational axis direction (hereinafter simply referred to as “axial direction”). It includes a pair of flange portions 3b and 3b which are continuous and extend outward in the radial direction of the rim (hereinafter simply referred to as “radial direction”). Further, the rim 3 includes a recessed groove-shaped well portion 3c having a smallest outer diameter between the rim seat portions 3a and 3a, and a body having an outer diameter larger than that of the well portion 3c and smaller than that of the rim seat portion. The portion 3d is provided side by side in the axial direction. For example, the well portion 3c is provided close to one rim sheet 3a, but may be a central portion, and the shape and / or arrangement thereof is not particularly limited. Further, the body portion 3d is formed with a larger width in the axial direction than the well portion 3c.

  Further, the rim 3 is formed of an annular body in which each of the parts extends substantially continuously in the circumferential direction around the rotation axis. Such a rim 3 is preferably formed of a substantially non-stretchable metal material such as iron, aluminum alloy or magnesium alloy.

  In the present embodiment, the disk 4 has a substantially disc shape offset to the outside of the vehicle, and is fixed to an axle (or axle hub) (not shown). Further, the disk 4 can be appropriately bent into a bowl shape as shown in the drawing in order to increase the rigidity, and further, a penetrating cavity 4a is provided as appropriate from the viewpoint of weight reduction and heat dissipation. Such a disk 4 is preferably formed of a substantially non-stretchable metal material, such as iron, aluminum alloy or magnesium alloy, similar to the rim 2.

  In addition, as shown in an enlarged view in FIG. 2, the rim 3 protrudes radially inward on the inner peripheral surface 3i side and extends in a ring shape in the circumferential direction provided at a distance in the axle direction. A pair of first ring pieces 6, 6 is provided. The inner peripheral surface 3i of the rim 3 means a surface on the side opposite to the side on which the tire 2 of the rim 3 is mounted. In the present embodiment, the first ring piece 6 is formed in a flange shape extending continuously in the circumferential direction. As a result, the inner ring-shaped void O extending in the circumferential direction surrounded by the two ring pieces 6, 6 facing each other and the inner peripheral surface 3 i of the rim 3 therebetween is formed in the rim 3.

  Further, first engagement grooves 9 extending in the circumferential direction are formed on the inner surfaces of the first ring pieces 6 facing each other. In the present embodiment, each of the first engagement grooves 9 has the same diameter, the same groove width GW, and the same groove depth GD with the rotation axis of the rim 3 as the center. In the present embodiment, the first engagement groove 9 extends continuously in the circumferential direction.

  Further, in the present embodiment, the first ring piece 6 is fixed to the inner peripheral surface 3i of the rim 3 in advance by a fixing ring piece 6A and fixing means such as welding or screwing to the inner peripheral surface 3i. And a later attached ring piece 6B fixed to the inner peripheral surface 3i later than the ring piece 6A.

  The fixing ring piece 6A is provided on the well portion 3 side in the axial direction. The method for forming the fixing ring piece 6A is not particularly limited, but it is desirable that the fixing ring piece 6A be integrally formed by, for example, casting or forging. Thus, by previously forming one fixed ring piece 6A on the inner peripheral surface 3i of the rim 3, the productivity of the wheel 1 is improved.

  Further, in the present embodiment, the retrofitting ring piece 6B is formed in a ring shape whose outer peripheral surface 6o has an outer diameter slightly smaller than the inner diameter D1 of the body portion 3d of the rim 3. Therefore, the second ring piece 6B can be moved in the axial direction along the trunk portion 3d of the rim 3 before being fixed to the rim 3, and the position thereof is adjusted. The rim 3 has an inner diameter of the rim seat portion 3a or the like so that the post-attach ring piece 6B can be fitted into the inner peripheral surface of the body portion 3d from the flange 3b side far from the well portion 3c. It is set larger than the outer diameter D1.

  The disk 4 is provided with one second ring piece 7 projecting radially outward and extending in the circumferential direction between the first ring pieces 6, 6. The second ring piece 7 is disposed in the space O of the rim 3 and has an outer diameter D2 smaller than the inner peripheral surface 3i of the body portion 3d of the rim 3. Further, the second ring piece 7 has a width smaller than the width of the void O in the axial direction. As a result, a gap formed between the second ring piece 7 and the first ring piece 6 is formed on both axial sides of the second ring piece 7.

  Further, on both side surfaces of the second ring piece 7 in the axial direction, second engagement grooves 10 and 10 which are opposed to the first engagement groove 9 and are paired are provided. The second engagement groove 10 extends in the circumferential direction around the rotation axis of the rim 3 and has the same groove width GW and groove depth GD as the first engagement groove 9 in this embodiment. In addition, it is formed in an annular shape that is continuous in the tire circumferential direction.

  The damper member 5 has a rectangular shape whose cross section is horizontally long and includes a pair of axially juxtaposed members, and is mounted in a gap formed by the first ring piece 6 and the second ring piece 7. Specifically, both end portions 5e and 5e in the axial direction of the damper member 5 are inserted into the first engagement groove 9 and the second engagement groove 10 and locked. The intermediate portion 5c of the damper member 5 extends in the space O without being restricted in the axial direction, and does not contact the rim 3 and the disk 4 when no load is applied. Therefore, this portion can be easily deformed according to the relative movement between the rim 3 and the disk 4.

  A method for manufacturing such an elastic wheel 1 will be briefly described. First, as shown in FIG. 4, one damper member 5, the disk 4, the other damper member 5, and a retrofit ring 6B are sequentially mounted and temporarily assembled toward the fixed ring piece 6A. Thereafter, as shown in FIG. 5, the retrofitted ring piece 6 </ b> B is pressed in the axial direction with respect to the fixed ring piece 6 </ b> A using a press or the like, and each damper member 5 is compressed. The damper member 5 held in a compressed state is in close contact with the groove surfaces of the engagement grooves 9 and 10 with high pressure. As a result, a very large frictional force is obtained on the contact surface between the first and second ring pieces 6 and 7 and the damper member 5. While maintaining this state, the post-attachment ring piece 6B is fixed integrally to the inner peripheral surface 3i of the rim 3 by fixing means (welding in the present embodiment) such as welding or screwing.

  Here, although not particularly limited, if the pressing force for compressing the damper member 5 is too small, the frictional force between the damper member 5 and the engagement grooves 9 to 10 cannot be sufficiently increased. For this reason, the coupling force between the two tends to decrease, and slipping or the like is likely to occur, and as a result, the steering stability tends to decrease. In addition, when the pressing force is excessively large, the damper member 5 tends to be damaged such as cracks, or the vibration absorbability of the damper member 5 is lowered and noise performance tends to be deteriorated. From this point of view, it is desirable to press the retrofitting ring piece 6B toward the first ring piece 6A with a force in the axle direction of 10 kN or more, more preferably 15 kN or more, and the upper limit is 30 kN or less. More preferably, it is 25 kN or less.

  The damper member 5 compressed in this way can smoothly transmit torque between the rim 3 and the disk 4 and can greatly reduce transmission loss due to slip or the like. In addition, since such an elastic wheel 1 does not require, for example, the damper member 5 to be vulcanized and bonded to the rim 3 or the disk 4, it can be manufactured on a general wheel manufacturing line, and productivity is greatly improved. To do. However, it goes without saying that an adhesive or the like may be used in combination.

  In the elastic wheel 1, the radial displacement of the rim 3 with respect to the disk 4 is absorbed by the shear deformation of the damper member 5. This exhibits an excellent buffering effect against a small vibration input within the radial gap provided between the outer peripheral surface of the second ring piece 7 and the inner peripheral surface 3i of the rim 3. The comfort and noise performance in the passenger compartment can be greatly improved. On the other hand, when the elastic wheel 1 receives an extremely large vibration in the radial direction, the outer peripheral surface of the second ring piece 7 and the inner peripheral surface 3i of the rim 3 are both in direct contact with each other. Limits large radial displacement, ensuring safe travel.

  Here, the groove depth GD and the groove width GW of the first engagement groove 9 (or the second engagement groove 10) are not particularly limited, but a sufficient contact area with the damper member 5 is not limited. Therefore, the groove depth GD is preferably 3 mm or more, more preferably 5 mm or more, and still more preferably 8 mm or more. On the other hand, if the groove depth GD is too large, the damper member 5 becomes excessively large, so that it is preferably 15 mm or less. Further, the groove width GW along the radial direction of the first engaging groove 9 (or the second engaging groove 10) is preferably 100% or more, more preferably 150% or more with respect to the groove depth GD. Further, the upper limit is preferably 400% or less, more preferably 300% or less.

  As shown in the enlarged cross-sectional view of FIG. 6, the damper member 5 is integrally bonded to the outer peripheral surface of the main body 5A made of fiber reinforced rubber R and covers at least 50% of the main body 5A. And a cover portion 5B that protects 5A.

  The fiber reinforced rubber R constituting the main body 5A includes a rubber 5a and fibers 5b embedded in the rubber 5a and reinforcing the rubber 5a. Such a fiber reinforced rubber R can exhibit great rigidity without deteriorating the vibration absorption performance of the damper member 5 by the fibers 5b having a higher tensile elastic modulus than rubber. Therefore, problems such as delay in the steering response of the wheel when turning the steering wheel, which tends to occur in conventional elastic wheels, wobbling feeling at the neutral steering angle, and damping of the wheel at low speed (small vibration) are effective. To be suppressed.

  The material of the fiber 5b is not particularly limited. For example, organic fibers such as nylon, polyester, rayon, vinylon, aromatic polyamide, cotton, cellulose resin, or crystalline polybutadiene, boron, glass fiber, carbon, etc. Inorganic fibers can be preferably used. Particularly preferably, an organic fiber is desirable from the viewpoint of light weight and adhesiveness to rubber, and an organic fiber cord is employed in this embodiment. In addition, a metal fiber can also be used if necessary.

  Various fibers such as short fibers and / or long fibers are employed as the fibers 5b, and cords c formed by twisting long fibers, particularly filaments, are desirable. The main body 5A of the present embodiment has a cord c extending continuously in the circumferential direction, as shown in a simplified manner in FIG. The cord c preferably has a length exceeding the length of one circumference of the damper member 5 as a long fiber. Since the main body 5A has a large tensile rigidity in the circumferential direction, the shear strain in the circumferential direction of the damper member 5 can be suppressed to be smaller when torque is transmitted between the disk 4 and the rim 3. Accordingly, for example, the responsiveness of the wheels during acceleration or deceleration of the vehicle is greatly improved. In order to exhibit such an effect more reliably, the total mass of the cord c forming the long fiber per one damper member 5 is 50% or more of the total fiber mass, more preferably 60% or more, More preferably, 70% or more is desirable.

  FIG. 8 shows an example of a method for manufacturing the main body 5A. The main body 5A of the present embodiment is made, for example, by continuously winding a ribbon-shaped cord ply P in a spiral shape to form a ply laminate 5L and vulcanizing it. The cord ply P is preferably a sheet-like one including a plurality of cords 5b arranged in parallel and unvulcanized rubber 5a covering the cords 5b. Although not shown, the main body 5A can be formed by winding a cord-like body in which a topping rubber is attached to one cord c in a spiral manner and vulcanizing it.

  Further, as shown in FIG. 9, the main body 5A may include a cord 5b1 extending along the circumferential direction and a cord 5b2 extending along the axial direction. Each cord 5b1 and 5b2 intersects at an angle of substantially 90 °. Since the cord 5b2 extending along the axial direction shows a large resistance to the axial compression or tensile force of the damper member 5 generated during turning, the lateral rigidity of the damper member 5 is improved, and steering stability is further improved. Helps to increase. Note that all the cords 5b of the damper member 5 may be arranged along the axial direction.

  Further, as shown in FIG. 10, the main body 5A may include cords 5b3 and 5b4 inclined obliquely with respect to the circumferential direction. Particularly in this example, the damper member 5 has a cord 5b3 inclined at an angle θ1 of greater than 10 ° and less than 50 ° with respect to the circumferential direction, and the cord 5b3 is opposite to the circumferential direction and 10 ° with respect to the circumferential direction. And a cord 5b4 inclined at an angle θ2 of less than 50 °. The cords 5b3 and 5b4 preferably have an intersection angle (θ1 + θ2) greater than 0 and less than 90 °. The main body 5A including the intersecting cords 5b3 and 5b4 has high rigidity in the circumferential direction of the damper 5. Therefore, as in the case of FIG. 7, when a large torque (torsion) is applied to the damper member 5 during driving or braking of the vehicle, the torsion angle of the damper 5 can be suppressed. Thereby, the response at the time of driving and braking of the vehicle can be improved.

  Each of the main bodies 5A does not change the rigidity in the radial direction (thickness direction) so much, and therefore does not impair the vibration absorption during traveling. Therefore, the excellent riding comfort of the elastic wheel 1 can be maintained as it is. In each of the above-described embodiments, the fiber 5b using the cord c is shown, but these may be replaced with short fibers, or short fibers may be used in combination. Further, the main body 5A of FIGS. 9 and 10 can be formed by alternately winding the cord plies P having the respective cords, for example.

  The amount of fibers contained in the main body 5A can be variously changed in accordance with the intended performance. However, when an organic fiber cord is used as in the present embodiment, the area occupied by the cord in the cross-sectional area of the main body is all. The cross-sectional area is preferably 45% or more, more preferably 50% or more, and the upper limit is preferably 90% or less, more preferably 80% or less.

  Further, the rubber 5a constituting the main body 5A is not particularly limited, but preferably has low exothermic property and fatigue resistance in addition to good adhesion to the fiber 5b. For example, natural rubber, styrene butadiene rubber or butadiene Rubber is desirable. These can be used alone or in combination of two or more.

  The rubber 5a of the main body 5A is preferably a rubber composition having a complex elastic modulus E * of 0.5 to 5.0 MPa, more preferably 1.0 to 3.0 MPa, from the viewpoint of vibration absorption effect. Further, the rubber composition preferably has a loss tangent tan δ of 0.01 to 0.4, more preferably 0.01 to 0.2 in order to suppress heat generation due to repeated deformation. The complex elastic modulus E and the loss tangent tan δ are both values measured with a viscoelastic spectrometer at a temperature of 70 ° C., initial elongation of 10%, dynamic strain of ± 1.0%, and a frequency of 10 Hz.

  The covering portion 5B is integrally bonded to the outer peripheral surface 5Ao of the main body 5A. The method for adhering the covering portion 5B to the main body 5A is not particularly limited, but various methods such as adhesion by curing of the covering portion 5B can be adopted in addition to vulcanization adhesion and adhesion by an adhesive.

  The covering portion 5B needs to cover at least 50% of the outer peripheral surface 5Ao of the main body 5A. If it is less than 50%, the area exposed to the outside of the main body 5A is increased, and the chance that the main body 5A is damaged by foreign matter or the like from the outside increases. From such a viewpoint, the covering portion 5B is preferably 70% or more of the outer peripheral surface 5Ao of the main body 5A, more preferably 80% or more, still more preferably 90% or more, and most preferably the entire region (this mode is shown in FIG. 6). It is desirable to coat. Thereby, the covering portion 5 </ b> B of the present embodiment is in contact with both the rim 3 and the disk 4.

  Further, the covering portion 5B is preferably one having elasticity capable of obtaining a large elongation. Accordingly, when the main body 5A is deformed, the body 5A can be deformed and follow it. Therefore, the original performance of the elastic wheel 1 is not impaired.

  The material constituting the covering portion 5B is not particularly limited, but preferably rubber or elastomer. In particular, those having heat resistance and / or oil resistance are suitable.

  Further, the brake device disposed close to the wheel 1 generates heat up to a high temperature, and braking is frequently repeated particularly on a winding road, so that the brake rotor or brake shoe rises to several hundred degrees Celsius. In the experiments by the inventors, when the covering portion 5B is not provided, it has been found that the main body 5A that receives the heat may generate heat up to about 100 to 150 ° C. Accordingly, it is desirable that the covering portion 5B has heat resistance that does not cause a significant change in physical properties up to a temperature of 100 ° C. or higher, more preferably 150 ° C. For example, an elastic material having a ratio (EB2 / EB1) of 0.70 or more of the initial (new) breaking elongation EB1 and the breaking elongation EB2 after aging at 160 ° C. for 5 days is 0.70 or more. desirable. The elongation at break is synonymous with “elongation at break” in JIS K6251.

  Examples of such heat-resistant elastic materials include butyl rubber such as butyl rubber and halogenated butyl rubber, ethylene propylene rubber, ethylene propylene diene rubber, fluorine rubber, silicone rubber or hydrogenated diene rubber, chlorinated polyethylene, A brominated copolymer of paramethylstyrene and isobutylene is desirable. These may be used alone or in combination of two or more if possible. Further, as described above, even if the rubber is inherently low in heat resistance, 5 parts by mass or more, more preferably 10 parts by mass or more of nanocomposite as a nanoscale filler is added to 100 parts by mass of the rubber polymer. By doing so, heat resistance can be easily improved. Further, a large amount of the anti-aging agent, more specifically, 1 part by mass or more, more preferably 3 parts by mass or more may be added to 100 parts by mass of the rubber polymer.

  Further, the oil resistance of the covering portion 8 only needs to withstand a relatively mild oil such as grease, and each of the above-described elastic materials has such oil resistance.

  The covering portion 5B includes a dynamically crosslinked rubber, a dynamically crosslinked polyolefin, a polyurethane, a styrene-butadiene-styrene copolymer, a styrene-isoprene-styrene copolymer, a styrene-isobutylene-styrene copolymer, or A thermoplastic elastomer such as a hydrogen compound of any one of the above copolymers can also be suitably used. Thermoplastic elastomers can be processed with ordinary plastic molding machines and do not require vulcanization (crosslinking). Therefore, the productivity of the covering portion 5B is improved.

Further, since the cord c of the organic fiber is densely embedded, the main body 5A of the damper member 5 tends to have a large electrical resistance value, and as a result, the rim 3 and the disk 4 tend to be insulated. is there. If the wheel 1 becomes an electrical non-conductor in this way, static electricity generated on the vehicle side cannot be released to the ground, and radio noise or the like is likely to occur. From this point of view, the covering portion 5B is preferably made of a conductive material having a volume resistivity of 1 × 10 ⁸ (Ω · cm) or less.

  A rubber material or the like that can exhibit such conductivity can be realized by blending a rubber or elastomer with a necessary amount of a conductive substance. As the conductive material, for example, carbon black, metal oxide, carbon nanotube, metal fine wire, and / or metal powder are used. When carbon black is blended, the blending amount is preferably 40 parts by weight or more, more preferably 50 parts by weight or more with respect to 100 parts by weight of the rubber polymer. In addition, since there exists a tendency for rubber | gum to become hard when the compounding quantity of carbon black increases too much, Preferably 70 weight part or less is desirable.

The covering portion 5B having such conductivity is disposed so as to contact both the rim 3 and the disk 4 as in the present embodiment, so that the electric resistance value of the wheel itself (the rim 3 and the disk 4 the electric resistance value) between 4 10 ⁸ (Ω) or less, and more preferably, to 10 ⁷ (Omega) below.

  Moreover, the coating thickness t of the coating portion 5B is not particularly limited, but if the thickness t is too small, there is a possibility that trauma or the like that penetrates the coating portion 5B and reaches the main body 5A easily occurs. From such a viewpoint, the covering thickness t of the covering portion 5B is preferably 0.1 mm or more, more preferably 0.3 mm or more. The upper limit of the coating thickness t is not particularly limited, but if it is too large, the weight of the wheel tends to increase. Therefore, it is preferable to keep the thickness to 5 mm or less, more preferably 2.5 mm or less.

  In the damper member 5 provided with such a covering portion 5B, the main body 5A, which is a substantial strength member, does not come into direct contact with external foreign substances and oils and fats during traveling, and directly receives ultraviolet rays and heat. There is nothing. Therefore, the performance of the main body 5A that substantially determines the performance of the damper member 5 can be maintained over a long period of time by sacrificing the covering portion 5B. Furthermore, since the covering portion 5B is provided by being bonded to the main body 5A, it is possible to block oxygen or reduce a permeation amount to the damper member 5. Therefore, oxygen deterioration of the main body 5A can be suppressed over a long period of time. In addition, in order to improve the oxygen impermeability of the covering portion 5B, a plate-like filler such as mica and / or montmorillonite may be included.

  FIG. 11 shows still another embodiment of the present invention. In this embodiment, the disk 4 is provided with a pair of first ring pieces 6 and the rim 3 is provided with a second ring piece 7. Thus, the first ring piece 6 can be provided on one of the rim 3 or the disk 4, and the second ring piece 7 can be provided on the other of the rim 3 or the disk 4.

  As mentioned above, although especially preferable embodiment of this invention was explained in full detail, it cannot be overemphasized that this invention can be deform | transformed into a various aspect, without being limited to embodiment of illustration.

  The following elastic wheel (size: 18 × 7) was prototyped, and the damage state of the damper member was examined by running the vehicle. Aluminum alloys were used for both the disc and rim.

Example 1
The following additive (unit: PHR) was blended with hydrogenated acrylonitrile rubber (manufactured by Nippon Zeon Co., Ltd., 2020) and kneaded with a kneader to extrude a rubber sheet having a thickness of 1 mm.
ISAF 60
Zinc oxide 5
Stearic acid 1
Dicumyl peroxide 3.2
Anti-aging agent 6
Wax 1.5
Tackifier 4
DOP 20
And the said rubber sheet was affixed on the whole outer peripheral surface of the ring-shaped main body prepared beforehand, the vulcanization | cure was performed with the metal mold | die, and the coating | coated part was adhere | attached integrally on the main body. The specifications of the main body and the finished damper member are as follows.
Specifications of the main body Rubber compounding ratio (NR: SBR: BR: H-NBR = 40: 30: 20: 10)
Textile material: Nylon Driving density: 50.4 / 50mm
Finished damper member (cross-sectionally long rectangular shape)
Width: 38mm
Thickness: 13mm
Corner chamfer: R = 2mm
Outer diameter: about 423mm
Inner diameter: about 397mm

Next, the damper member was mounted in a compressed state between the rim and the disk as shown in FIG. 1 to obtain an elastic wheel. The damper member and the rim or disk were not bonded. Then, a tire was assembled on this elastic wheel, and the vehicle was driven at 20000 km at an internal pressure of 2.4 kPa and a load of 4 kN on a drum tester at a speed of 80 km / H. After running, the coated part was checked with the naked eye and found to be intact.

Furthermore, the vehicle equipped with this elastic wheel traveled about 50 km on an unpaved rough road. Thereafter, when the coated portion was observed with the naked eye, small scratches were scattered on the surface, but were not peeled off at all. Further, when the covering portion was peeled off and the main body was observed, it was not damaged at all and no adhesion of oil was observed.

  Further, this elastic wheel was left outdoors for about one month in the summer, but no cracks or cracks were formed on the surface of the covering portion.

Furthermore, the volume specific resistance value of the covering portion is 2 × 10 ⁶ (Ω · cm), and the electric resistance value of the elastic wheel in which the covering portion is incorporated (resistance value between the rim and the disk is applied voltage 500 V, temperature 25 ° C. , Humidity 50%) was 1 × 10 ⁶ (Ω) or less, and it was confirmed that good conductivity was exhibited.

(Example 2)
The following additives (unit: PHR) were blended in 100 parts by weight of an elastic elastomer (EXXPRO90-10 manufactured by ExxonMobil Co., Ltd.) and kneaded with a kneader, and a 1 mm thick sheet was extruded and molded in the same manner as in Example 1. Affixed to the body and molded. The specifications of the main body and the finished damper member are the same as those in the first embodiment.
lSAF 50
Zinc oxide 5
Stearic acid 1
Paraffin oil 5
Tackifier 10
200 mesh sulfur 0.5
Vulcanization accelerator 1

Next, a damper member was assembled between the rim and the disk (FIG. 1) and, as in Example 1, was run on a drum tester at a speed of 80 km / H for 20000 km, but no damage was seen in the covering portion. .

In addition, after the above test, small scratches were found on the surface of the covering portion, which traveled about 50 km on an unpaved rough road, but there were no scratches reaching the main body. Furthermore, when the covering portion was peeled off and the main body of the damper member was observed, it was not damaged at all and no adhesion of oil was observed.

(Example 3)
A damper member was molded using a 1 mm-thick chloroprene rubber having the following composition (parts by mass) in the covering part. When the same test as in Examples 1 and 2 was performed, the same test result was obtained.
Chloroprene rubber (WRT) 100.0
Magnesium oxide 4.0
Zinc oxide 5.0
Stearic acid 1.0
Accelerator 22 1.0
GPF 50.0
DOP 8.0

(Comparative example)
An elastic wheel was prototyped using a damper member consisting only of a main body not provided with a covering portion, and a test similar to the example was performed. The volume resistivity of this elastic wheel was found to be larger than 1 × 10 ⁸ (Ω · cm) and substantially non-conductive. In addition, as a result of the actual vehicle running test, some scratches were generated on the main body, and some fibers were exposed. In addition, swelling that seemed to be due to the oil content of the suspension was partially observed. Further, when the temperature of the rubber surface was measured immediately after running, it reached 150 ° C. Further, when this elastic wheel was left outdoors on the 30th of summer, many cracks were generated on the surface of the damper member.

It is sectional drawing which shows one Example of the elastic wheel of this invention. FIG. FIG. 3 is an AA end view of FIG. 2. It is a fragmentary sectional view showing the temporary assembly state of a damper member. It is sectional drawing which shows the state which pressed the retrofit ring and compressed the damper member. It is sectional drawing of a damper member. It is a perspective view of the main body of a damper member. 4 is a schematic side view for explaining a method of molding the main body of the damper member. It is a fragmentary perspective view of the main body which shows other embodiment. It is a fragmentary perspective view of the main body which shows other embodiment. It is a fragmentary perspective view of the elastic wheel which shows other embodiment of a damper member. It is sectional drawing explaining a prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Elastic wheel 2 Tire 3 Rim 4 Disc 5 Damper member 5A Main body 5a Rubber 5b Fiber 5B Covering part 6 First ring piece 6A Fixed ring piece 6B Retrofit ring piece 7 Second ring piece 9 First engagement groove 10 Second engagement groove

Claims (7)

A rim extending in the circumferential direction capable of supporting a tire, a substantially disk-shaped disk fixed to an axle, and a ring having a ring shape extending in the circumferential direction and connecting the rim and the disk. An elastic wheel having a member,
The damper member includes a main body made of fiber reinforced rubber reinforced with fibers, and a covering portion that is integrally bonded to the outer peripheral surface of the main body and protects the main body by covering at least 50% thereof. And elastic wheel.   The elastic wheel according to claim 1, wherein the covering portion is made of rubber or elastomer and covers the entire outer peripheral surface of the main body.   The covering part is made of butyl rubber, halogenated butyl rubber, diene rubber added with hydrogen, diene rubber not added with hydrogen, ethylene propylene rubber, ethylene propylene diene rubber, chloroprene rubber, chlorosulfonated polyethylene rubber, fluorine rubber, acrylic rubber. The elastic wheel according to claim 1, comprising at least one of silicone rubber, chlorinated polyethylene, or a copolymer of brominated paramethylstyrene and isobutylene.   The covering portion may be dynamically cross-linked rubber, dynamically cross-linked polyolefin, polyurethane, styrene-butadiene-styrene copolymer, styrene-isoprene-styrene copolymer, styrene-isobutylene-styrene copolymer, or any one of the above The elastic wheel according to claim 1, which is a hydrogen compound of a copolymer. 5. The elastic wheel according to claim 1, wherein the covering portion has a conductivity having a volume resistivity of 1 × 10 ⁸ (Ω · cm) or less and contacts both the rim and the disk.   The elastic wheel according to claim 1, wherein the covering portion has a thickness of 0.1 to 5.0 mm.   The coating portion has heat resistance such that a ratio (EB2 / EB1) of an initial breaking elongation EB1 to a breaking elongation EB2 after aging at 160 ° C. for 5 days is 0.70 or more. The elastic wheel in any one of.

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