JP2009040212A - Tire puncture preventive member and wheel assembly - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a structure capable temporarily making a two wheeler such as a bicycle travel in a stable state even in a puncture state, in a tire puncture preventive member arranged between an outward part in the tire radial direction in an inner peripheral surface of a tire for the two wheeler and an outer peripheral surface of a tube. <P>SOLUTION: This tire 3 puncture preventive member 5 is annularly arranged between the outward part in the tire radial direction in the inner peripheral surface 3b of the tire 3 for the two wheeler and the outer peripheral surface of the tube 4. An outer peripheral plane part 5a is formed in an outside place in the tire radial direction in a state of not receiving external force, and a wide inner peripheral plane part 5b is formed in an inside place in the tire radial direction, and is formed so that a cross-sectional shape becomes a substantially trapezoidal shape. This constitution can make the two wheeler travel in the stable state by stably grounding over the wide area, since a place corresponding to the outer peripheral plane part 5a of the puncture preventive member 5 in the tire 3 easily becomes a substantially plane shape in a grounding part vicinal place even in a puncture. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a puncture-preventing member that prevents a tire for a motorcycle from being punctured, and a wheel assembly in which the puncture-preventing member is assembled.

  In general, a bicycle tire is configured by being mounted on a rim forming an inner ring portion of a wheel in a state in which a tube into which air is injected is installed. There are two types of puncture factors other than mischief in this bicycle tire, namely “riding puncture (so-called rim strike puncture)” and “stabbed puncture”.

  Here, “climbing puncture (so-called rim-punching puncture)” means that the tube crushed between the stepped portion and the rim when riding on the stepped portion or the like when the air pressure in the tube was relatively low. This occurs when the tube is compressed until it reaches a certain state, and the tube cracks and the air in the tube escapes. On the other hand, “stabbed puncture” is a sharp metal or glass stab that has fallen on the ground and pierced from the outer periphery of the tire into the tire, creating a hole in the tube and causing air in the tube to escape. It is caused by. In this punctured state, if the rider forcibly rides a bicycle, the tire and the tube from which air has been removed are sandwiched between the grounding surface and the rim, and the impact force from the grounding surface and the rim. It often acts on the tube without being weakened, and is severely damaged, such as having many holes in the tube, making it impossible to use afterwards.

  As a method for preventing puncture of a bicycle tire, Patent Document 1 and the like describe a method of filling a tube with an elastic resin (referred to as an elastic resin) (specifically, most of the cross-sectional area in the tube is filled with an elastic resin). Or filling so that the inside of the tube is completely made of only the elastic resin). When the tube is filled with the elastic resin in this way, the stabbed object is pierced so as to reach the inside of the tube from the tire, and the pierced hole made in the elastic resin layer is not It is prevented from being punctured by being blocked by the elastic resin of the portion. Further, even when the tire rides on a stepped portion or the like, it does not deform until the tube is completely crushed between the rim and the stepped portion, so that no riding puncture occurs.

  However, when such a method of filling a large amount of elastic resin in the tire tube is employed, the weight of the wheel becomes extremely large (for example, the tire 1) as compared with a normal tire in which air is injected into the tire tube. In addition, the weight of the book becomes heavy at around 1200 g), and the shock absorption performance when receiving a shock during boarding is reduced, so that there is a drawback that riding comfort is deteriorated. Furthermore, since the degree of absorption of impact force is lower than that in which air is injected into the tire tube, the grounding surface is connected to the rim, fork, and frame that support the tire via the elastic resin in the tube. There is also a problem that the traveling distance of the rim, fork, and frame decreases.

  In addition, since expensive equipment is required for injecting the elastic resin, there is a disadvantage that the filling cost per tire is also expensive, and further, when the tire is worn and replaced, the resin is reused. When trying to use it, it is necessary to tear off the tire and take out the elastic resin, and there is a problem that it takes much time and labor.

  Patent Documents 2 and 3 disclose that a cross section (a cross section including a tire shaft) is substantially semicircular between a rim and a tube inside a tire (a portion closer to the inside of the tire in the radial direction of the tire, a portion closer to the rim). There is disclosed a structure in which a puncture-preventing member having a shape elasticity (however, the inner end in the tire radial direction is shaped to fit between rims) is disclosed.

  According to this structure, even when riding on a step or the like with the air pressure in the tube being relatively low, the tube is elastically received by the puncture-preventing member, so it is deformed until the tube is completely crushed. There is an advantage that the puncture is difficult to occur. In addition, even if a stabbed object pierces to reach the inside of the tube from the tire, and the air from the tube escapes and punctures, the tube from which the air has escaped can be received by the puncture-preventing member, so the tube is damaged much It is possible to temporarily run the bicycle without any problems. Further, since the cross-sectional area of the puncture-preventing member is only about half of that in the tire, the same material is used when compared with a structure in which almost the volume portion in the tube is filled with elastic resin as in Patent Document 1. Even when is used as a member for preventing puncture, there is an advantage that the increased weight of the tire can be halved. In addition, almost half of the tire has a tube filled with air, so it is possible to suppress the degree of reduction in shock absorption performance when receiving a shock during boarding. It is possible to minimize the decrease in the running durability distance.

  However, since the puncture-preventing member is disposed at a position near the rim inside the tire, there is a drawback that there is almost no function for reducing the occurrence rate of the puncture puncture.

  As structures that can cope with this drawback, Patent Documents 4 to 6 describe a cross-section between a portion of the inner peripheral surface of the tire that is closer to the outer side in the radial direction of the tire and an outer peripheral surface of the tube (so-called a portion closer to the tire). (A cross section including a tire shaft) A structure in which a puncture-preventing member having an approximately crescent-shaped elasticity is provided is disclosed. As a material for forming the puncture-preventing member, hard rubber (having a Shore A hardness of about 60) is used.

  According to this structure, even when riding on a step or the like with the air pressure in the tube being relatively low, the puncture prevention member is interposed between the tube and the tire, so that the impact from the tire is prevented from being punctured. There is an advantage that it is difficult to be deformed until the tube is completely crushed by being elastically received by the working member, and it is difficult to generate a puncture. In addition, even when a stabbed object is stabbed, the stabbed object first stabs the puncture prevention member and does not easily reach the tube, so that the occurrence rate of the stabbed object puncture itself can be reduced. In addition, even if the stabbed material penetrates the puncture prevention member and reaches the tube, and the air from the tube escapes and punctures, the force from the ground plane can be received to some extent by the puncture prevention member, and Since the punctured tube can be received from the inside by the puncture-preventing member, it is possible to temporarily run the bicycle. In addition, since the cross-sectional area of the puncture-preventing member is less than half that in the tire, there is an advantage that the increased weight of the tire can be halved. Also, the volume of approximately half or more of the tire is equipped with a tube filled with air, so it is possible to suppress a reduction in shock absorption performance and a reduction in the running distance of the rim, fork, and frame. Can be minimized.

In this structure, the tire is mounted on the rim by fitting the puncture-preventing member at a position radially outward on the inner circumferential surface of the tire, and further fitting a tube inside the tire. This is done by fitting the inner peripheral end portion (bead portion) into the rim.
JP 2006-341679 A JP-A-11-245610 JP 2001-121907 A Microfilm of Japanese Utility Model No. 60-183518 (Japanese Utility Model Publication No. 62-90805, Fig. 3) Japanese Patent Laid-Open No. 5-201213 Japanese Patent Publication No. 4-36881

  In Patent Documents 4 to 6, the puncture-preventing member is described and illustrated as having a substantially crescent-shaped cross section, but the puncture-preventing member is not subjected to external force (that is, punctured. If it is formed to have a substantially crescent-shaped cross section even in a state where it does not receive the force from the tube), the cross-sectional shape of the outer peripheral surface portion (the portion on the outer surface in the tire radial direction) is circular. Therefore, when the tire is punctured, the shape of the ground contact portion of the tire tends to be an arc shape along the shape of the puncture preventing member. Therefore, in the punctured state where the air has escaped, the area of the ground contact portion of the tire is small, and there is a possibility that running at this time becomes unstable.

  The puncture-preventing member having a substantially crescent-shaped cross section also has a substantially circular cross-sectional shape on the inner peripheral surface portion (the portion on the inner surface in the tire radial direction). Therefore, when the tire is punctured, the rim is placed on the inner peripheral surface portion of the substantially circular arc-shaped anti-puncture member via the punctured tube, but the rim is contacted via the tube. Since the portion to be rounded has an arc shape, the position where the rim is received may be shifted during traveling, which may cause unstable traveling during puncture.

  Further, as the puncture-preventing member, a relatively hard rubber (for example, a Shore A hardness of around 60) is used, so that the tube is torn when both ends of the puncture-preventing member rub against the tube. There was a case. Also, because the puncture prevention member itself is hard, when air is injected into the tube, the tube enters the gap between the end of the puncture prevention member itself and the inner peripheral surface of the tire, and wrinkles are generated. In some cases, the wrinkled tube was torn.

  Furthermore, when manufacturing this type of puncture-preventing member in large quantities, there is an advantage that it can be manufactured at a relatively low cost when formed by a mold, and foaming can also be performed relatively easily. However, even if an attempt is made to form a puncture-preventing member having a substantially crescent-shaped cross section of this kind and a ring shape when viewed from the side, a puncture-preventing member 20 is formed as shown in FIGS. Since both end portions 20a of the corresponding cross-sectional shape are curved, when the puncture preventing member 20 is molded, the surface (so-called inner peripheral surface) 20b on the inner side in the tire radial direction of the puncture preventing member 20 is The puncture-preventing member 20 cannot be removed from the dies 21 and 22 because of interference with the surfaces 21a and 22a of the dies 21 and 22 corresponding to, and therefore cannot be manufactured by the dies 21 and 22. There was also a drawback.

  SUMMARY OF THE INVENTION The present invention solves the above-mentioned problem. In a tire puncture prevention member disposed between a tire radial outer side portion and an outer peripheral surface of a tube on an inner peripheral surface of a tire for a motorcycle, a bicycle or the like The motorcycle can be temporarily driven in a stable state even in a punctured state, and the tube does not come into contact with the puncture-preventing member during normal use. An object of the present invention is to provide a structure that can be manufactured relatively inexpensively using a mold.

  In order to solve the above-described problems, the tire puncture preventing member according to the present invention is annularly disposed between the radially outer portion of the inner peripheral surface of the tire for a motorcycle and the outer peripheral surface of the tube. A tire puncture prevention member that is not subjected to an external force, and is formed with an outer circumferential flat portion that is flat in a cross section including a tire shaft at an outer location in the tire radial direction, and inward in the tire radial direction. The cross section is flat in the cross section, the outer peripheral plane section and the inner peripheral plane section wider than the rim on which the tire is mounted are formed, and the cross section has a substantially trapezoidal shape. It is characterized by being.

  With this configuration, since the outer peripheral flat portion that is flat in the cross section is formed at the outer portion in the tire radial direction of the puncture preventing member, even if puncture occurs and air has escaped from the tube In the vicinity of the ground contact part, the part corresponding to the outer peripheral plane part of the puncture preventing member in the tire is likely to be substantially flat, so that it can be stably grounded in a wide area and can be stably driven even when temporarily traveling. it can. In addition, since the outer peripheral plane part and the inner peripheral plane part wider than the rim are formed at the inner part in the tire radial direction of the puncture preventing member, a tube is placed on the inner peripheral plane part at the time of puncture. The vehicle can be run with the rim placed well. Furthermore, at the time of puncture, the outer peripheral flat portion and the inner peripheral flat portion of the puncture preventing member act so that the cross-sectional shape of the tire becomes flat, and the inner peripheral end portion of the tire may come off and fall off from the rim during traveling. Thus, the puncture can be performed in a safer and more stable state. Further, since the shape of the cross section of the puncture-preventing member is formed to be a substantially trapezoidal shape, it can be formed without any trouble by a casting mold or a rubber press mold.

  In addition to the above configuration, the present invention is characterized in that the entire puncture preventing member is formed of a material having a Shore A hardness of 10 to 40 or a Shore C hardness of 30 to 60. Since the prevention member is relatively soft (softer than the tube as well as the tire), when the puncture prevention member is installed, it is disposed between the inner peripheral surface of the tire for the motorcycle and the outer peripheral surface of the tube Thus, when air is injected into the tube, the bulge preventing member is pressed against and closely contacts the inner peripheral surface of the tire. Therefore, unlike the conventional case, the tube does not enter between the end portion of the puncture preventing member itself and the inner peripheral surface of the tire, and there is no problem that the tube is wrinkled and broken due to this. . Even when the puncture-preventing member and the tube are rubbed, the puncture-preventing member is very soft and the tube will not be torn. Also, in the unlikely event that puncture and air escapes from the tube, the tube and rim are placed on the puncture prevention member, but the puncture prevention member is a soft material, The impact force received from the ground contact surface on the tube from which the air has escaped is alleviated, and it is possible to satisfactorily prevent the tube from being damaged even when the motorcycle or the like is temporarily run.

  In addition, the puncture-preventing member of the present invention is characterized by being formed of an elastomer (including rubber) having an expansion ratio of 1.0 to 5.0. The impact force can be absorbed well, and by increasing the foaming ratio to be greater than 1, the puncture-preventing member can be reduced in weight, and therefore the increased weight of the wheel assembly can be reduced. . By setting the expansion ratio to 5.0 times or less, even when used for a long period of time, deterioration due to aging of the puncture-preventing member, almost no deterioration due to so-called sag, and a good anti-puncture function, etc. are prolonged. Can be maintained over a period of time. In other words, if the expansion ratio is larger than 5.0 times, if it is used for a long period of time, it may be compressed in the direction of gravity due to so-called sag, and a good anti-puncture function may not be obtained. However, according to the above configuration, such a problem does not occur.

  In addition, the puncture-preventing member of the present invention is characterized by being formed of a material made of thermoplastic elastomer, urethane or rubber. According to this, the puncture-preventing member is a foamable material. The weight of the member can be reduced, and the increased weight due to the provision of the puncture-preventing member can be suppressed.

  Further, the puncture-preventing member of the present invention is characterized in that a hollow portion is formed from the central portion in the width direction to the vicinity of both ends in the width direction, and according to this, a relatively hard material is used as the puncture-preventing member. Even in this case, when air is injected into the tube, both end portions of the puncture-preventing member are likely to be well shaped along the inner peripheral surface of the tire and the outer peripheral surface of the tube, and each end portion of the puncture-preventing member itself The tube does not enter between the tire and the inner peripheral surface of the tire, and the tube does not cause a problem that the tube is wrinkled and broken. In addition, even when the end portion of the puncture preventing member and the tube are rubbed, the end portion of the puncture preventing member is likely to be recessed toward the hollow portion, so that the tube can be prevented from being broken.

  Further, the puncture-preventing member of the present invention is made of a material having different hardness in the width direction center part including the outer peripheral flat part and the width direction both end parts, and the width direction both end parts are softer than the width direction center part. It is formed.

  With this configuration, the central portion in the width direction of the puncture-preventing member is formed of a material that is harder than both end portions in the width direction, so that the possibility that a stabbed object penetrates through this portion can be suppressed to a lower level. The occurrence rate of physical puncture can be further reduced. In addition, since the central portion in the width direction including the outer peripheral plane portion is formed of a hard material, even if puncture occurs, the force from the ground contact surface and the tire side is applied by the central portion in the width direction including the outer peripheral plane portion. It can be received well and can travel better. In addition, since the central portion in the width direction including the outer peripheral flat portion is formed of a hard material, the portion corresponding to the outer peripheral flat portion of the puncture preventing member 5 at the time of puncturing can be made closer to a planar shape. Thus, the installation area during traveling can be increased, and the traveling stability during puncture can be improved. On the other hand, since both end portions in the width direction are formed of a softer material than the central portion in the width direction, when air is injected into the tube when the anti-puncture member is attached to the tire, both end portions of the anti-puncture member are Due to this, the shape is well aligned with the inner peripheral surface and the outer peripheral surface of the tube, so that the tube does not enter between each end of the puncture prevention member itself and the inner peripheral surface of the tire. There is no problem that the tube is wrinkled and broken. Even when the end portion of the puncture preventing member and the tube are rubbed, the end portion of the puncture preventing member is soft, so that the tube can be prevented from being broken.

Further, the puncture-preventing member of the present invention is characterized in that a hollow portion is not formed in the central portion in the width direction including the outer peripheral flat portion, and hollow portions are formed in the vicinity of both ends in the width direction. To do.
With this configuration, even when the whole member for puncture prevention is formed of a single material having a certain hardness, the hollow portion is not formed in the central portion in the width direction of the member for puncture prevention. The possibility of piercing can be kept low, the incidence rate of puncture puncture itself can be reduced, and since there is no hollow part at the location corresponding to the outer peripheral plane part, It can be favorably supported by the flat portion and can travel well. On the other hand, since hollow portions are formed in the vicinity of both ends in the width direction, when air is injected into the tube when the puncture-preventing member is attached to the tire, both ends of the puncture-preventing member are on the inner peripheral surface of the tire. And the outer peripheral surface of the tube are likely to be well-shaped, and the tube will not enter between the end portions of the puncture prevention member itself and the inner peripheral surface of the tire. There is no problem that occurs and breaks. Moreover, even when each end portion of the puncture preventing member and the tube are rubbed, each end portion of the puncture preventing member is likely to be recessed toward the hollow portion, and the tube can be prevented from being broken.

  As described above, according to the present invention, since the outer peripheral flat portion that is flat in the cross section is formed at the outer portion in the tire radial direction of the puncture preventing member, the stable state even when traveling in a punctured state In addition, an outer peripheral plane part and an inner peripheral plane part wider than the rim are formed in the tire radial direction inner part of the puncture preventing member. It is possible to run well in a state where the rim is satisfactorily placed through the tube and in a state where the inner peripheral end of the tire is detached from the rim and prevented from falling off during running. Thereby, the driving | running | working at the time of puncture can be performed in a safer and stable state, and reliability improves. In addition, since the cross-sectional shape of the puncture-preventing member is formed to be a substantially trapezoidal shape, it can be formed without hindrance by the casting mold, and is used when manufacturing a large amount of puncture-preventing members. It can be manufactured relatively inexpensively using a mold.

  Moreover, when the puncture-preventing member is formed entirely from a material having a Shore A hardness of 10 to 40 or a Shore C hardness of 30 to 60, the puncture-preventing member is provided when air is injected into the tube and the tube is inflated. The tube is not pressed between the end portion of the puncture prevention member itself and the inner peripheral surface of the tire as in the past, and is pressed and in close contact with the inner peripheral surface side of the tire. Damage can be prevented, and damage due to rubbing between the puncture-preventing member and the tube can be prevented, improving reliability and durability. In addition, the impact force received from the ground contact surface on the tube from which air has escaped during puncture is well mitigated by the soft puncture preventing member, and damage to the tube at this time can be prevented well.

  Moreover, the impact force from a ground-contact surface can be favorably absorbed by using an elastomer having an expansion ratio of 1.0 to 5.0 as the puncture-preventing member. Moreover, by making the expansion ratio larger than 1, it is possible to reduce the weight of the puncture-preventing member, thereby reducing the increased weight of the wheel assembly. By setting the expansion ratio to 5.0 times or less, the puncture prevention member will not be deteriorated by so-called sag even if it is used for a long period of time, and a good puncture prevention function etc. Can be maintained.

  In addition, since a material made of thermoplastic elastomer, urethane, or rubber is used as the puncture prevention member, it is a foamable material. Therefore, the puncture prevention member can be reduced in weight, and the puncture prevention member can be arranged. Increased weight due to installation can be suppressed.

  Further, the puncture-preventing member is made of a material having different hardness in the width direction center portion including the outer peripheral flat portion and the width direction both end portions, and the width direction both end portions are made of a material softer than the width direction center portion. Thus, the occurrence rate of the puncture puncture itself can be further reduced, the puncture can be performed more favorably, and each end portion of the puncture prevention member itself and the inner peripheral surface of the tire It is possible to reduce problems that the tube is wrinkled and broken due to the tube entering between them, and that the tube is broken due to rubbing between the end portion of the puncture preventing member and the tube.

  Further, as a member for preventing puncture, a hollow portion is not formed in the central portion in the width direction including the outer peripheral plane portion, and by using a member in which a hollow portion is formed in the vicinity of both ends in the width direction, It is possible to further reduce the occurrence rate of puncture punctures and to improve the performance during puncture, and between the end portions of the puncture prevention member itself and the inner peripheral surface of the tire. It is possible to reduce inconvenience that the tube is wrinkled and broken due to the tube entering, and that the tube is broken due to rubbing between the end portion of the puncture preventing member and the tube.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1A is a sectional view of a wheel assembly according to an embodiment of the present invention (cross section including a tire shaft), FIG. 1B is a sectional view of the wheel assembly in a punctured state, and FIG. ) Is an overall side view of a single member for preventing puncture according to an embodiment of the present invention, and FIGS. 3A and 3B are a sectional view (cross section including a tire shaft) and an enlarged sectional view of the member for preventing puncture. It is. 1A, 1B, 3A, and 3B are cross-sectional views of a portion on the grounding side of the wheel assembly and the puncture prevention member.

  As shown in FIG. 1A, a wheel assembly 1 has a bead portion 3a that is an inner peripheral end portion of a rubber tire 3 on a rim 2 that is an inner ring portion attached to an axle and a spoke (not shown). The rubber tube 4 into which air is injected and the puncture-preventing member 5 according to the embodiment of the present invention are internally fitted in an internal space constituted by the rim 2 and the tire 3. Is done. The puncture-preventing member 5 is disposed between a radially outward portion 3b in the tire radial direction and an outer peripheral surface of the tube 4 on the inner peripheral surface of a bicycle tire 3 as an example of a two-wheeled vehicle. Note that a relatively hard rubber material (Shore A hardness of 60 or more) is used as the tire 3, and a relatively soft rubber material (Shore A hardness of 40 to 60) is used as the tube 4.

  As shown in FIG. 2A, the puncture-preventing member 5 has an annular shape when viewed from the side. Further, as shown in FIGS. 3A, 3B, and 1B, the puncture preventing member 5 is in a naturally left state where it does not receive external force (it receives a force from the tube 4 as described later). In a state where there is no puncture (including a puncture state), an outer periphery which is flat in a lateral cross section including the tire shaft (axle) (that is, the cross section shown in FIGS. 3A and 3B) at an outer location in the tire radial direction. A flat surface portion 5a is formed, and an inner peripheral flat surface portion 5b that is flat in the cross section is formed at an inner position in the tire radial direction. Similarly, in a natural state where no external force is received, the inner peripheral plane part 5b is formed to be wider than the outer peripheral plane part 5a and the rim 2 (see FIG. 1B), The inner peripheral plane part 5b is connected via the inclined surface part 5c that inclines and spreads from both ends of the outer peripheral plane part 5a toward both ends 5e in the width direction. It is formed so that the cross-sectional shape is a substantially trapezoidal shape. In addition, 8 in FIG.1 (b) is the ground (grounding surface). In addition, the inclined surface portion 5c does not necessarily have to be inclined linearly in the cross section, and may have a curved shape (a convex curved shape or a concave curved shape). As shown in FIG. 1A, the puncture-preventing member 5 has a size such that the area ratio with respect to the total cross-sectional area in the tire 3 is 20% to 40% when air is injected into the tube 4. Is formed.

  The puncture prevention member 5 is entirely formed of a material having a Shore A hardness of 10 to 40 (or a Shore C hardness of 30 to 60). More specifically, it is manufactured using an elastomer having an expansion ratio of 1.0 to 5.0, more specifically, a material made of a thermoplastic elastomer, urethane, or rubber.

  In the case of using a thermoplastic elastomer or rubber, the puncture preventing member 5 is formed by, for example, extrusion molding, cutting after the extrusion process, and joining the cut surfaces into an annular shape. The cut surfaces may be bonded using an adhesive or may be mechanically bonded using a so-called tucker or the like.

  When cast urethane is used, the cross section of the puncture-preventing member 5 is divided into left and right as shown in FIGS. 4 (a) and 4 (b) or FIGS. 5 (a) and 5 (b). For example, two-component urethane or the like is injected between the upper mold (upper mold) 11 and the lower mold (lower mold) 12 having the grooves 11a and 12a having such cross sections. And mold. At this time, since the cross-sectional shape of the puncture preventing member 5 is trapezoidal, the formed puncture preventing member 5 can be easily removed from the upper mold 11 and the lower mold 12 without any trouble after molding. Further, in this case, the circular shape having the same shape as the puncture preventing member 5 shown in FIG. 2A and having circular grooves 11a and 12a in plan view as shown in FIGS. When the upper mold 11 and the lower mold 12 are used, the upper mold 11 and the lower mold 12 need to have large plane areas, and the manufacturing cost becomes expensive. As shown in a) and (b), when a circular upper mold 11 and a lower mold 12 having elliptical grooves 11a and 12a in plan view are used, the upper mold is compared with the case of the circular shape. The area of 11 and the lower mold 12 can be small, and the manufacturing cost can be reduced. FIG. 2B shows the puncture-preventing member 5 manufactured by this method. Even in this case, the puncture-preventing member 5 is relatively soft, so that the tire radial direction on the inner peripheral surface of the tire 3 is shown in FIG. When it is disposed between the outer portion 3 b and the outer peripheral surface of the tube 4 and air is injected into the tube 4, a circular shape in a side view along the tire 3 and the tube 4 is obtained.

  The mounting operation to the rim 2 such as the tire 3 in the above configuration is performed as follows. First, the puncture-preventing member 5 is fitted into the tire radial direction outward position 3b on the inner circumferential surface of the tire, then the tube 4 is further fitted inside, and further, the inner circumferential end portion (bead portion 3a) of the tire 3 Is fitted into the rim 2 (specifically, a groove formed inside the rim 2). In this state, air is injected into the tube 4. In the state where air is not injected into the tube 4, the puncture preventing member 5 does not receive the compressive force from the tube 4, and thus has a substantially trapezoidal cross section as in the manufacturing process. Is relatively soft, and when air is injected into the tube 4, it is arranged in a substantially crescent shape that is well along the radially outward position 3 b on the inner peripheral surface of the tire 3 and the outer peripheral surface of the tube 4. Established. Further, since the puncture-preventing member 5 is softer than the tube 4, when the air is injected, the puncture-preventing member 5 is pressed and brought into close contact with the inner peripheral surface 3b side of the tire 3 when the tube 4 expands. Therefore, unlike the prior art, the tube does not enter between the width direction both ends 5e of the puncture preventing member 5 itself and the inner peripheral surface of the tire, and the tube 4 is wrinkled and broken due to this. There will be no inconvenience. Even when the puncture-preventing member 5 and the tube 4 are rubbed, the tube 4 is not broken even if the puncture-preventing member 5 is worn away because the puncture-preventing member 5 is soft. As a result, damage to the tube 4 due to rubbing of the tube 4 with the wrinkle or puncture-preventing member 5 can be prevented, and reliability and durability are improved.

  In addition, since the vibration received from the ground contact surface of the tire 3 is well absorbed not only by the tube 4 but also by the relatively soft puncture-preventing member 5, the shock absorbing performance during boarding is maintained well. As a result, the ride comfort is maintained well, and the impact force on the rim 2, fork, and frame is reduced, and the reduction in the running durability distance can be minimized.

  Further, as described above, the cross-sectional area of the puncture-preventing member 5 is formed such that the area ratio with respect to the total cross-sectional area in the tire 3 is 20% to 40% in a state where air is injected into the tube 4. Therefore, the weight of the tire can be reduced to less than half (for example, when the area ratio is 40%, in the case of an unfoamed thermoplastic elastomer), Weight can be reduced to about 550 g). Further, by foaming so that the expansion ratio is greater than 1, the puncture preventing member 5 can be further reduced in weight. If the expansion ratio is larger than 5.0 times, when used for a long period of time, the so-called sag may result in a state of being compressed in the direction of gravity, making it impossible to obtain a good anti-puncture function or the like. As described above, by suppressing the foaming ratio to 5.0 times or less, such a problem does not occur.

  Further, according to this structure, since the puncture preventing member 5 is interposed between the tube 4 and the tire 3, even when riding on a step or the like while the air pressure in the tube 4 is relatively low, the contact is prevented. The impact from the ground side (tire 3) is elastically received by the puncture-preventing member 5, and it is difficult to deform until the tube 4 is completely crushed, and it is difficult to get on and puncture. Further, even when the stabbed object is stabbed, the stabbed object is first stabbed into the puncture prevention member 5, so that it is difficult to reach the tube 4, and the occurrence rate of the stabbed object puncture itself can be reduced.

  Furthermore, even if the stabbed material penetrates the puncture-preventing member 5 and reaches the tube 4, and the air from the tube 4 escapes and punctures, the force from the grounding surface is received to some extent by the puncture-preventing member 5. The punctured tube 4 can be received by the puncture-preventing member 5 from the inner side, so that the bicycle can be temporarily run.

  In particular, according to the above configuration, the outer peripheral flat surface portion 5a that is flat in the cross section is formed in the outer portion of the tire anti-puncture member 5 in the radial direction of the tire. 1B, the portion corresponding to the outer peripheral flat portion 5a of the puncture preventing member 5 in the tire 3 has a substantially planar shape in the vicinity of the portion of the ground contact surface 8 as shown in FIG. Thus, it is possible to ground stably over a wide area, and to travel in a stable state even when temporarily traveling in a punctured state. Further, since the outer peripheral flat surface portion 5a and the inner peripheral flat surface portion 5b wider than the rim 2 are formed in the inner portion in the tire radial direction of the puncture preventing member 5, the inner peripheral flat surface portion 5b of the inner peripheral flat surface portion 5b is formed during puncture. The rim 2 can be traveled with the tube 4 placed on the top, and the puncture-preventing member 5 is relatively soft, so that vibrations and impacts acting on the tire 3 can be reduced. Further, as shown in FIG. 1 (b), at the time of puncture, the outer peripheral flat surface portion 5a and the inner peripheral flat surface portion 5b of the puncture preventing member 5 have a flat cross-sectional shape of the tire 3 (the inner periphery of the tire 3). The end portion (bead portion 3a) acts so that the inner peripheral end portion 3a of the tire 3 is detached from the rim 2 during traveling, and is prevented from falling off. It can be performed in a safe and stable state.

  In addition, when a conventional method of filling a large amount of elastic resin in a tube of a tire is used, when the tire is worn and replaced, if the resin is to be reused, the tire is torn and the elasticity is increased. Resin had to be taken out, and it took a lot of time and effort. However, according to the above configuration, even when the tire 3 is replaced, the tire 3 is removed by a procedure reverse to the procedure for mounting the tire 3 described above. The tire 3 can be attached to the rim 2 by removing and replacing with a new tire 3, fitting the puncture-preventing member 5 and the tube 4. That is, the tire can be assembled to the new tire 3 with relatively little effort and time without tearing the tire or the like. In particular, a soft member is used as the puncture prevention member 5 as described above, and the attachment work of the puncture prevention member 5 into the tire 3 is facilitated by using a horizontally long but relatively small cross-sectional area. There are advantages that can be made.

  As described above, when a soft material is used as the puncture-preventing member 5, there is an advantage that it is possible to satisfactorily absorb the impact on the bicycle. However, the present invention is not limited to this, and as shown in FIG. While using the same hardness (for example, Shore A hardness 50-60) as the prevention member 5 from the center in the width direction of the puncture prevention member 5 to the vicinity of both ends in the width direction (that is, prevention of puncture) The hollow part 6 may be formed in the central part of the member 5 for use.

  According to this configuration, since the hollow portion 6 is provided, the weight can be reduced, and at the same time, the rigidity can be suppressed to be relatively low while using a hard material. Therefore, as compared with the case where a hard material not provided with the hollow portion 6 is used as the puncture preventing member 5, the tube 4 swells when air is injected, so that the puncture preventing member 5 is the tube 4 and the inside of the tire 3. As a result, the tube 4 is less likely to enter between the width direction both ends 5e of the puncture preventing member 5 itself and the inner peripheral surface of the tire. The trouble that the tube 4 is torn is less likely to occur. When the hollow portion 6 is formed in a wide range inside the puncture-preventing member 5 in this way, deterioration (so-called sag) is likely to occur with aging, so that a material having high elasticity is used. It is desirable to deal with it.

  Also in this configuration, the puncture preventing member 5 has a substantially trapezoidal shape similar to the case shown in FIG. 3 and FIG. Even when the air has escaped from the tube 4 due to puncture, the vehicle can travel in a stable state even when traveling temporarily in a punctured state.

Next, FIG. 7 and FIG. 8 show sectional views of a puncture preventing member and a wheel assembly according to another embodiment of the present invention.
As shown in FIGS. 7 and 8, the puncture-preventing member 5 according to this embodiment is made of a material having different hardness in the width direction center portion 5d including the outer peripheral flat surface portion 5a and the width direction both end portions 5e. It is comprised, and the width direction both ends 5e are formed with the softer material than the width direction center part 5d. In this embodiment, for example, the center part 5d in the width direction of the puncture preventing member 5 is formed of a material having a Shore A hardness of 40 to 60, and both end parts 5e in the width direction of the puncture preventing member 5 are The material is softer and has a Shore A hardness of 10 to 40 (or a Shore C hardness of 30 to 60).

  The puncture-preventing member 5 is formed, for example, on an extrusion molding machine in which the respective filling and feeding locations are partitioned, on the widthwise center portion 5d of the puncture-preventing member 5 and the widthwise end portions 5e of the puncture-preventing member 5. Although it is good to join and form each other, extruding a corresponding part, it is not restricted to this, After forming separately, you may join using an adhesive agent etc.

  According to this configuration, since the central portion 5d in the width direction of the puncture-preventing member 5 is hard, the entire puncture-preventing member 5 is relatively soft and has a Shore A hardness of 10 to 40 as in the above embodiment. Compared to the case of being formed of a certain material, vibrations received from the ground contact surface of the tire 3 during normal running in a non-punctured state cause the axles and the frame to pass through the relatively hard width direction central portion 5d. There is a disadvantage that it is easy to be transmitted to the passengers. However, since the central portion 5d in the width direction of the puncture-preventing member 5 is hard, even when the stabbed object is stuck in the widthwise central portion 5d where the stabbed object is highly likely to pierce during running, The possibility of penetrating 5d can be further reduced, and the occurrence rate of stinging punctures can be further reduced. Moreover, since the width direction center part 5d including the outer peripheral plane part 5a is formed with a hard material, even if it should be punctured, the width direction center part 5d including the outer periphery plane part 5a causes the ground contact surface and the tire 3 to The force from the side can be received well, and the vehicle can travel better. Moreover, since the width direction center part 5d including the outer peripheral plane part 5a is formed of a hard material, the portion corresponding to the outer peripheral plane part 5a of the puncture preventing member 5 in the tire 3 at the time of puncture is more It can be made close to a planar shape, the installation area during travel can be increased, and travel stability during puncture can be improved.

  Furthermore, while the incidence rate of the puncture puncture itself can be further reduced as described above, the width direction both end portions 5e are formed of a softer material than the width direction central portion 5d. When air is injected into the tube 4 at the time of mounting on the tire 3, the tube 4 swells so that both end portions 5 e in the width direction of the puncture-preventing member 5 are pressed and brought into close contact with the inner peripheral surface 3 b side of the tire 3. Therefore, unlike the prior art, the tube 4 does not enter between the width direction both ends 5e of the puncture preventing member 5 itself and the inner peripheral surface of the tire, and the tube 4 is wrinkled and broken due to this. There will be no inconvenience. Moreover, even when the width direction both ends 5e of the puncture preventing member 5 and the tube 4 are rubbed, since the width direction both ends 5e of the puncture preventing member 5 are soft, it is possible to reduce the breakage of the tube 4.

  That is, when the entire puncture-preventing member 5 is formed of a material that is relatively soft (of a material softer than the tube 4) and has a Shore A hardness of 10 to 40 (or a Shore C hardness of 30 to 60). Further, the tube 4 is torn due to the tube 4 entering between the widthwise both ends 5e of the puncture-preventing member 5 itself and the inner peripheral surface of the tire 3, and the width of the puncture-preventing member 5 While there is an advantage that the tube 4 can be prevented from being broken by rubbing the direction end portions 5e and the tube 4, the effect of suppressing the occurrence rate of stinging puncture is slightly reduced, and the support force for the tire 3 at the time of puncture is slightly There was a problem that there was a risk of lowering. However, according to the above-described configuration, it is possible to solve such a problem, while preventing the tube 4 from being broken, the occurrence rate of the stabbed object puncture can be further improved, and the supporting force for the tire 3 at the time of the puncture can be improved. The reliability can be further improved.

  FIG. 9 shows a cross-sectional view of a puncture-preventing member according to still another embodiment of the present invention. The puncture-preventing member 5 according to this embodiment includes the entire puncture-preventing member 5 as shown in FIG. Although it is formed of a relatively hard material, for example, a material having a Shore A hardness of 40 to 60, the hollow portion 6 is formed only in the vicinity of both ends 5e in the width direction, and the width direction including the outer peripheral plane portion 5a. The central portion 5d is in a solid state where no hollow portion is formed.

  With this configuration, even when the whole puncture preventing member 5 is formed of a single material having a constant hardness, the hollow portion 6 is not formed in the central portion 5d in the width direction of the puncture preventing member 5, The possibility that the stabbed object penetrates through the portion can be kept low, the occurrence rate of the stabbed object puncture itself can be reduced, and the hollow portion 6 is not provided at the location corresponding to the outer peripheral flat surface portion 5a. Therefore, it can be favorably supported by the outer peripheral plane portion 5a even during puncture and can travel well. Further, since the central portion 5d in the width direction including the outer peripheral flat portion 5a is formed of a solid hard material, the portion corresponding to the outer peripheral flat portion 5a of the puncture preventing member 5 in the tire 3 at the time of puncture is It can be made closer to a planar shape, the installation area during travel can be increased, and travel stability during puncture can be improved.

  On the other hand, since the hollow portion 6 is formed in the vicinity of both ends 5e in the width direction, when air is injected into the tube 4 when the puncture preventing member 5 is attached to the tire 3, the width of the puncture preventing member 5 is increased. Both end portions 5e in the direction tend to be well shaped along the inner peripheral surface of the tire 3 and the outer peripheral surface of the tube 4, and the width direction both end portions 5e of the puncture-preventing member 5 itself and the inner periphery of the tire as in the past The tube does not enter between the surfaces and the tube does not wrinkle due to this. Moreover, since each width direction both-ends part 5e of the member 5 for puncture prevention becomes easy to dent in the hollow part side, it can reduce that the tube 4 is torn and can improve reliability.

  In the above embodiment, the case where the wheel assembly to which the anti-puncture member is mounted is for a bicycle as an example of a motorcycle, but is not limited to this, and for motorcycles such as motorcycles and motorcycles. It is also applicable.

(A) is sectional drawing (cross section containing a tire shaft) of the wheel assembly which concerns on embodiment of this invention, (b) is sectional drawing of a puncture state (A) is the whole side view of the puncture prevention member according to the embodiment of the present invention, and (b) is the puncture prevention manufactured by the mold (casting mold) shown in FIGS. 5 (a) and 5 (b). Overall side view of a single component (A) And (b) is sectional drawing (cross section containing a tire shaft) and an expanded sectional view of the member for puncture prevention (A) And (b) is a plan view and a sectional view of a molding die (casting die) for producing the puncture preventing member (A) And (b) is a plan view and a cross-sectional view of another molding die (casting die) for manufacturing the puncture-preventing member Sectional drawing of the modification of the member for puncture prevention which concerns on embodiment of this invention Sectional drawing of the member for puncture prevention which concerns on other embodiment of this invention (A) is a sectional view of a wheel assembly using the puncture-preventing member (cross section including a tire shaft), and (b) is a sectional view in a punctured state. Sectional drawing of the member for puncture prevention which concerns on other embodiment of this invention (A) And (b) is a sectional view and an enlarged sectional view of a molding die for producing a conventional puncture-preventing member

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Wheel assembly 2 Rim 3 Tire 4 Tube 5 Puncture prevention member 6 Hollow part

Claims (8)

A tire puncture prevention member disposed in an annular shape between a radially outer portion of the tire for a motorcycle and an outer peripheral surface of the tube,
In a state where no external force is received, an outer peripheral plane portion that is flat in a cross section including the tire shaft is formed in an outer location in the tire radial direction, and is flat in the cross section in an inner location in the tire radial direction, Puncture prevention for a tire, characterized in that the outer peripheral flat part and an inner peripheral flat part wider than a rim on which the tire is mounted are formed, and the shape of the cross section is substantially trapezoidal. Materials.   2. The tire puncture prevention member according to claim 1, wherein the tire is entirely formed of a material having a Shore A hardness of 10 to 40 or a Shore C hardness of 30 to 60. 3.   The member for preventing puncture of a tire according to claim 1 or 2, wherein the member is formed of an elastomer having an expansion ratio of 1.0 to 5.0.   The tire puncture prevention member according to claim 3, wherein the tire puncture prevention member is formed of a material made of thermoplastic elastomer, urethane, or rubber.   The tire puncture prevention member according to claim 1, wherein a hollow portion is formed from a central portion in the width direction to a portion in the vicinity of both ends in the width direction.   The width direction center part including the outer peripheral plane part and the width direction both end parts are made of different hardness materials, and the width direction both end parts are formed of a softer material than the width direction center part. The member for preventing puncture of a tire according to claim 1.   2. The tire puncture preventing tire according to claim 1, wherein a hollow portion is not formed in a central portion in the width direction including the outer peripheral flat portion, and a hollow portion is formed in the vicinity of both ends in the width direction. Element.   A wheel assembly, wherein the puncture preventing member according to any one of claims 1 to 7 is disposed between an inner peripheral surface of a tire for a motorcycle and an outer peripheral surface of a tube.

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