JP2018176918A - Non-puncture tube - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a non-puncture tube having excellent riding feel while the tube includes lightness and durability by injection molding of thermoplastic elastomer.SOLUTION: A non-puncture tube Cof a hollow pipe shape in which, by thermoplastic elastomer, a cross sectional shape is formed in a similar shape by injection molding slightly larger than a cross sectional shape of an annular space 52 of a tire skin 51 which is detachably attached to an annular tire rim 53, the whole body is formed in an annular shape, and the tube is fitted into the annular space 52 in a slightly compressed state due to the tensile stress of the tire skin 51 in all directions, and has a constitution that a large number of continuous first hole portions 11 along an annular direction are continuously formed in an opposing state along a diameter direction at a prescribed pitch P on opposing both side face parts 3 between a grounding part 1 and an anti-grounding part 2 of the tube C.SELECTED DRAWING: Figure 7

Description

  The present invention relates to a hollow pipe-shaped no-puncture tube which has a durability which is not damaged even by numerous contact with the tire outer shell during elastic deformation and which is lightened in weight and excellent in ride comfort. is there.

  In the present specification, the "circumferential direction" of the tube or the tube divided body indicates the direction along the outer shape in the cross sectional view, and the "annular direction" indicates the axial direction of the annularly formed tube The “longitudinal direction” indicates the axial direction of the tube segment before forming in the tube.

  No-puncture tubes (hereinafter sometimes simply referred to as “tubes”) that do not puncture even when nails are pierced have been filed for various structures. As one of the no-puncture tubes, one disclosed in Patent Document 1 is known, and a large number of groove portions in a direction orthogonal to the annular direction of the tube are specified on the non-contact side (the rim side of the tire) of the tube. By providing the pitch, it is intended to simultaneously achieve both the weight reduction of the tube and the facilitation of the bending operation.

  In the tube of Patent Document 1, the tube is divided into a total of five tube divided bodies and injection-molded, and the five tube divided bodies are bent to form an annularly connected tube. In a (27 × 13/8) size tire, the length of one tube segment was 420 mm and its weight was 160 g. Therefore, the weight of one tube in which five tube divided bodies are connected in an annular shape is 800 g, and the circumferential length is 2100 mm.

  In the development of no-puncture tube, it is essential to simultaneously achieve the three factors of ride comfort, durability, and lightness due to the resilience and bending elasticity of the material in terms of the nature or function of the tube. Although the ride comfort and durability can be achieved by devising the material or shape of the tube, the achievement of light weight exacerbates the difficulty, in part in contradiction to the ride comfort and durability. Even in the above-described conventional tubes, although the ride comfort and durability can achieve the standard, there is a problem that the weight increase ratio to the air tube is too large in terms of weight and weight reduction can not be realized. The And, in the bicycle industry which is the main user of the tube, 500 g is considered as a standard for weight increase with respect to the air tube as a standard satisfying lightness.

JP, 2014-198552, A

  The present invention is based on the above findings and is excellent in lightness and durability due to the combination of the resilience and bending elasticity intrinsically provided by the thermoplastic elastomer which is a molding material, and the overall shape of the tube. The challenge is to provide a no-punk tube with a comfortable ride.

The invention of claim 1 for solving the above-mentioned problems is characterized in that the thermoplastic elastomer has a cross-sectional shape slightly smaller than the cross-sectional shape of the annular space of the tire shell removably attached to the annular tire rim. A hollow pipe-like no-puncture tube which is formed by injection molding in a large similar shape and is formed into a toroidal whole, and is fitted into the toroidal space in a slightly compressed state by tensile stress in all directions of the tire outer skin. There,
A large number of first holes continuous along the annular direction are continuous at a predetermined pitch in a state in which they are opposed along the radial direction on the mutually opposing side surfaces between the ground portion and the non-ground portion of the tube. It is characterized in that it is formed.

  The tube according to the invention of claim 1 is injection-molded in a hollow pipe shape by a thermoplastic elastomer so that the cross-sectional shape becomes a slightly larger similar shape to the cross-sectional shape of the tire outer skin, and the whole is circular It is deformed in an annular shape, slightly deformed in a cross sectional view, and in a state in which mutually opposing forces are applied at the abutment portions of the end faces of the tubes, that is, the tube formed in an annular shape is connected With no parts, it is fitted into the tire skin. Thus, in a state where the tube is fitted into the tire outer skin, the outer peripheral surface of the tube adheres closely to the inner peripheral surface of the tire outer skin except for the portion facing the tire rim, and the tube becomes integral with the tire And elastically deform. A hollow structure in which the tube is formed into a hollow pipe shape by a thermoplastic elastomer, and a plurality of first side surfaces which are continuous to each other between the ground portion and the non-ground portion of the tube along the annular direction. One hole is continuously formed at a predetermined pitch in a state of being opposed along the diametrical direction, and a portion excluding the first hole is continuous along the circumferential direction along the longitudinal direction of the tube. Since the tube has a shape-retaining rigidity and resilience required as a tube, the weight of the tube can be reduced, and good ride comfort can be ensured.

  Also, the portions of both side portions connected to the grounding portion in the tube are the portions with the largest amount of deformation in use and are the portions that are rubbed against the inner circumferential surface of the tire outer skin. Since the one hole portion is continuously formed along the annular direction, the contact area itself with the tire outer skin becomes small, and the wear or damage of the tube to the inner circumferential surface of the tire outer skin is reduced. As a result, the durability of each side portion of the tube can be secured.

  In the invention of claim 2, in the invention of claim 1, a large number of first groove portions are continuously formed at a predetermined pitch along the direction orthogonal to the annular direction of the tube in the anti-grounding portion of the tube. It is characterized by

  According to the second aspect of the present invention, the anti-contact portion of the tube is a portion which is contracted by applying a compressive force by curving the linear tube in an annular shape, so the annular direction of the portion In addition to the weight reduction of the tube itself by forming a large number of first groove portions continuously at a predetermined pitch along the direction orthogonal to the direction, the linear tube is bent to form an annular shape In this case, the bending operation becomes easy, and the generated compressive force decreases, so that the internal stress generated in the tube itself becomes small, and a stable annular shape can be maintained.

  In the invention of claim 3, according to the invention of claim 2, the anti-grounding portion of the tube is formed to be thicker than other portions, and the first hole portion and the first groove portion are circles of the tube. Between the adjacent first grooves in the tube, a plurality of second holes are formed at the same pitch as the first grooves along the direction in which the first grooves are formed. Are formed continuously.

  According to the invention of claim 3, the tube itself is reduced in weight by forming a large number of second holes in a portion close to the anti-grounding portion of the tube. Since the anti-grounding portion of the tube is formed to be thicker than other portions, the deformation resistance of the tube is not reduced even if the second hole portion is formed in the anti-grounding portion.

  The invention of claim 4 is the invention according to any one of claims 1 to 3, wherein a large number of oblong triangles having an obtuse-triangular cross section are formed between the first holes adjacent in the annular direction in the ground portion of the tube. The second groove portion is characterized by being continuously formed at the same pitch as the first hole portion along the formation direction of the first groove portion.

  According to the invention of claim 4, the tube itself is further reduced in weight by forming a large number of second groove portions having an obtuse-angled triangular cross section in the above-mentioned portion of the ground portion of the tube. Since the space between the second groove portions in the ground portion of the tube is in close contact with the inner peripheral surface of the tire and grounded, there is almost no deterioration in ride comfort.

  The invention of claim 5 is characterized in that, in the invention of any one of claims 1 to 4, the resin hardness (A) of the thermoplastic elastomer which is a molding material of the tube is 93 to 97.

  According to the invention of claim 5, the resin hardness (A) of the thermoplastic elastomer which is the molding material of the tube is provided to each side surface for weight reduction of the tube by using one of 93 to 97. Due to the presence of the first hole, the required rigidity is secured by preventing the rigidity of the tube from decreasing.

In the invention of claim 6, according to the invention of any one of claims 1 to 5, the tube is divided into a plurality of sections along the annular direction, and the ends thereof are connected to each other to form a plurality of rings. Consists of tube segments,
Both end portions in the annular direction of each tube segment are characterized in that the whole is annularly coupled via a coupling portion formed integrally with itself.

  According to the invention of claim 6, since the tube is constituted by a plurality of tube divided bodies, there is a molding advantage when there is a restriction of molding length at the time of injection molding. In addition, it is necessary to form a tube segment in an arc shape corresponding to the diameter of the center of the tire in order to be able to be fitted into the tire, and as this method, a molded article of a tube segment molded in a straight line There are two cases: deformation by annealing, which is secondary processing, and injection molding, in advance, in an arc shape corresponding to the diameter of the center of the annular space of the tire outer shell. Further, the plurality of tube segments fitted in the annular space of the tire outer shell are connected with one another by fitting the tube segments together by being connected via the integrally formed connecting portion. It can prevent that the phase of the circumferential direction of two tube divisions becomes different (the two tube divisions to be connected get relatively caught).

  The invention according to claim 7 is the fitting according to the invention according to claim 6, wherein one end of the tube segment in the annular direction is inserted into and fitted to the hollow hole of another tube segment to be connected. The projection is characterized in that it is integrally formed.

  According to the invention of claim 7, in the tube segments connected with each other, the fitting projection integrally formed at one end of the annular direction of one of the tube segments is the other of the tube segments. By being fitted in the hollow portion, the integrity of connection is enhanced, and the rod becomes like a single tube.

  According to the present invention, the opposite side surface portions between the grounding portion and the non-contacting portion of the annular tube fitted in the annular space of the tire outer shell are opposed in the diameter direction of the cross section of the tube A plurality of first holes formed continuously along the torus direction, and a plurality of holes formed in a direction opposite to the torus direction in a thicker anti-ground portion than the other portions of the tube By forming a large number of second holes or the like formed between the adjacent first groove portions in the anti-grounding portion of the tube or the tube, it has the necessary shape holding rigidity and resilience as a tube. The weight of the tube can be reduced, and good ride comfort can be ensured.

Is a front view of a partially cutaway of the tube divided bodies C ₁ a to form a tube C _1. (A), (b) is a perspective view of the tube divided bodies C ₁ a from different directions. (A), (b) are each a enlarged sectional view of the X ₁ -X ₁ line, respectively, of FIG. 1 and X ₂ -X ₂ line. Is a partial perspective view showing the connecting structure of the tube divided bodies C ₁ a. (A) ~ (c) are diagrams showing a process of forming a tube C ₁ of 5 tubes divided body C ₁ a and connected to the annular shape. It is a cross-sectional view of a state where the tube C ₁ is fitted to the tire outer skin 51. FIG. 6 is a front view in which a portion of the tire T in which a tube C ₁ is fitted into an annular space 52 of a tire outer skin 51 is cut away. Is a cross-sectional view of a tube split body C ₂ a of the tube C _2.

Hereinafter, the present invention will be described in more detail by way of examples. First, with reference to FIGS. 1 to 5, it will be described the tube C ₁ according to the present invention. The tube C ₁ corresponds to a (27 × 1 3/8) -sized tire, and is constituted by five straight tube divided bodies C ₁ a ′ ′ and fitted into a tire T of a bicycle In this case, the five linear tube divided bodies C ₁ a ′ ′ are arc-shaped corresponding to the diameter (Dt) of the tire T (the diameter of the center K of the cross section of the tire outer skin 51 shown in FIG. 7). is Niwan song at both ends in the longitudinal direction, itself being connected with each other via a connection portion integrally formed, is formed into a tube C ₁ of annular as a whole. The straight tube divided body C ₁ a ′ ′ is an irregular cylindrical shape having a hollow portion 4 with a circular cross section of inner diameter (dc), as shown in FIGS. 1 to 3, and is formed in the tube C ₁ A total of the grounding portion 1 on the outer circumferential side in the state, the non-grounding portion 2 facing the grounding portion 1 and the inner circumferential side, and the side portion 3 between the grounding portion 1 and the non-grounding portion 2 The portion of each side surface portion 3 opposite to the ground portion 1 has a constant thickness, so the external shape of the cross section of the portion of the tube segment C ₁ a ′ ′ excluding the anti-ground portion 2 is It is part of a circle. The anti-contact portion 2 of the tube segment C ₁ a ′ ′ is formed to have a trapezoidal partial cross section to correspond to the form in which it is fitted into the opening of the rim 53 of the tire T via the tire skin 51 The thickness of the anti-ground portion 2 of C ₁ a ′ ′ is formed thicker than the thicknesses of the ground portion 1 and the side portions 3. For this reason, in the tube division body C ₁ a ′ ′, a portion to be the anti-grounding portion 2 of a part in the circumferential direction of the cylindrical portion having a constant thickness is formed into a trapezoidal cross-section It has become a state.

The length (L) of the tube segment C ₁ a ′ ′ is 420 mm, the inner diameter (dc) and the outer diameter (Dc) of the circular hollow portion are 200 mm and 280 mm, respectively, The height (H) between the part 2 and the part 2 is 310 mm.

A large number of first holes 11 extend in the longitudinal direction (tube C _{1 in} each of the side surface portions 3 between the grounding portion 1 and the non-contacting portion 2 in the tube segment C ₁ a ′ ′) in a state of facing along the diameter direction. In the state where it is formed, it is continuously formed at a constant pitch P along the annular direction). In the anti-grounding portion 2 of the tube segment C ₁ a ′ ′, a large number of first grooves 12 are formed. The first groove 11 is formed at the same position as the first hole 11 along the longitudinal direction and at the same pitch P as the first hole 11 along the direction orthogonal to the longitudinal direction. A plurality of second holes 13 having an inner diameter smaller than that of the first holes 11 are formed at a pitch P between them. Furthermore, in the ground portion 1 of the tube segment C ₁ a ′ ′, a large number of second groove portions 14 having an obtuse triangular cross-section are formed continuously at a pitch P at the same position as the second hole portion 13 along the longitudinal direction. By forming the first and second holes 11 and 13 and the first and second grooves 12 and 14 in the tube divided body C ₁ a ′ ′, the tube divided body C can be obtained. ₁ a ′ ′ Thus, the first groove formed in the anti-grounding portion 2 of the tube divided body C ₁ a ′ is reduced in weight, and the tube C ₁ in which a total of five tube divided bodies C ₁ a ′ ′ are annularly connected is reduced 12 and the second hole 13 make it easy to bend the tube segment C ₁ a ′ ′ in an annular shape without generating a large compressive deformation, that is, without generating a large compressive internal stress .

A total of five tube segments C ₁ a ′ ′ are curved in an arc and are connected to each other at both ends in the longitudinal direction to form an annular tube C ₁ as shown in FIGS. 2 and 4. and as shown in FIG. 6, Hamago突"the longitudinal end of the other tube divided bodies C ₁ a to be connected" tubes divided body C ₁ a is fitted into the hollow portion 4 of the A connecting piece portion 16 having a projecting portion 15 and a hook-like locking projection 16a formed at the tip end portion is projected in the longitudinal direction on the portion of the non-contacting portion 2, and the other end portion is A fitting groove portion 17 to which the connection piece portion 16 is fitted is formed in the non-grounding portion 2, and an engagement end portion of the fitting groove portion 17 is inserted and engaged with the locking projection 16 a Recess groove portion 18 is formed by this connection structure, divided into two tube segments which are annealed and arc-shaped as described later. 'By connecting, when fitted into the annular space 52 of the tire outer skin 51, two tubes divided body C ₁ a coupled' C ₁ a without is rotated relative circumferential direction There is also an advantage that the two tube segments C ₁ a ′ are connected to each other with the regular connection position secured along the circumferential direction.

Since each tube segment C ₁ a ′ ′ is curved in an arc shape and is connected to each other at the end in the longitudinal direction, the circumferential length on the inner circumferential side becomes shorter than the circumferential length on the outer circumferential side, Corresponding to the above, both end surfaces 5 of the tube segment C ₁ a ′ ′ are formed to be inclined at a predetermined angle (θ) with respect to the longitudinal direction.

The divided tube body C ₁ a ′ is made of various thermoplastic elastomers (TPE) such as styrene-based (SBC), olefin-based (TPO), urethane-based (TPU), ester-based (TPEE), and amide-based (TPAE) as raw materials Thermoplastic elastomers (TPE) suitable for obtaining impact resilience and flexural modulus, which are physical properties essential as a tube, are ester-based elastomers (TPEE) and urethane-based elastomers (resins). TPU) or polymer alloys of these, and injection molding dies include the outer shape of the tube segment C ₁ a ′ ′ and the first and second holes 11 and 13 and the first and second holes. A pair of split molds for forming the groove portions 12 and 14 and a central portion of a hollow cylindrical cavity formed by the pair of split molds, Cube divided body C ₁ a "can be molded using a rod-shaped slide die for molding the hollow portion 4 of. Also, if the number of divided tubes (the number of tubes split body) is large, or toddlers When the outer diameter is small as in the case of a bicycle tube, it may be formed into an arc shape which is the final shape at the time of injection molding. In this case, a pair of splits whose entire shape is an arc shape The rod-shaped slide mold inserted into the center of the hollow curved cylindrical cavity formed by the mold is formed in the same arc shape as the arc shape of the tube segment to be molded, and after molding, the arc It becomes possible to mold by taking out the arc rod-like slide mold from the inside of the molded product by rotating it around the center and molding it into an arc shape which is the final shape at the time of injection molding. No need for subsequent molding .

With regard to the elastic properties of the thermoplastic elastomer that is the material of the tube, the flexural modulus needs to be in the range of 15-1700 MPa to ensure riding comfort, and 45% with respect to the impact resilience. It needs to be larger than that. Here, as the resin height (A) of the thermoplastic elastomer, (90) is sufficient for the tube of the shape described in Patent Literature 1 described in the item of “Background Art”, but in the present invention, _Since the first holes 11 are provided in the opposing side surfaces 3 for the weight reduction of 1, using (93 to 97) as the resin height (A) of the thermoplastic elastomer by increasing the hardness, it employs a means for securing the rigidity of the both side surfaces 3 of the tube C _1. Due to this hardness, the hardness of the thermoplastic elastomer itself which is the material of the tube is increased, the rigidity of the tube C ₁ is secured, and the first hole 11 of each side portion 3 provided for weight reduction is used. In order to support the elastic deformation of the side portion 3, the necessary resilience as the tube C ₁ is obtained.

Then, in order to connect the three tube divisions C ₁ a ′ ′ linearly injection-molded into an annular shape to form the tube C ₁ , the following secondary molding is performed. That is, FIG. 5A. As shown in (b) and (b), the divided tube C ₁ a ′ is held in a curved state with respect to the curved copying surface formed on a dedicated annealing jig (not shown). Set and leave in this condition for about 20 hours in a temperature-controlled room holding a temperature of about 80 ° C. to make the straight tube divided body C ₁ a ′ ′ follow the copying surface of the annealing jig. are annealed to the song. straight tube divided bodies C ₁ a radius of curvature "was annealed tube divided body C ₁ is curved in the intermediate state a 'is coupled by a tube became tube C ₁ Since it is larger than the radius of curvature of the divided body C ₁ a, a total of five tube divided bodies C ₁ a ′ Is further bent when it is fitted into the annular space 52 of the tire outer skin 51. FIG. 5 (c), 5 tubes divided body C ₁ a ', one of the tubes divided body C ₁ a to be connected' connection piece 16 and the locking projections 16a of the other tube divided body C _It is connected in an annular shape by being respectively fitted in the fitting groove portion 17 and the locking groove portion 18 of ₁ a ′, and a state in which the annular space 52 of the tire outer shell 51 is fitted is shown. Before fitting into 52, it is non-circular. A total of five tube divided bodies C ₁ a ′ connected without connecting one of a total of five connecting portions to the annular space 52 of the tire outer shell 51 can be used as the tire outer skin 51. The tube C ₁ can be easily fitted into the annular space 52 of the tire outer skin 51 by connecting the non-connected tube divisions C ₁ a ′ to each other in the annular space 52. It becomes.

As described above, both end surfaces 5 of the arc-shaped tube divided body C ₁ a fitted in the annular space 52 of the tire outer skin 51 are in the longitudinal direction (annular direction) generated inside the tire outer skin 51. The five tube divisions C ₁ a are integrally formed in the annular space 52 of the tire outer skin 51, because the state in which they are in contact with each other is maintained by the tensile force (internal stress) along the The tube segment C ₁ a ′ in the connected state and subjected to secondary forming has a bending radius larger than that of the tube segment C ₁ a of the final shape. When fitting the two tube divided bodies C ₁ a ′ into the annular space 52 of the tire outer skin 51 in a connected state, the phases along the circumferential direction are not shifted and inserted.

Thus, the first and second holes 11 and 13 and the first and second grooves 12 and 14, and in particular, the tube divisions C ₁ a ′ ′ constituting the tube C ₁ , in particular, each tube division body C ₁ a "on each side portion 3 opposite the by forming a first hole portion 11, one tube divided bodies C ₁ a" is to reduce the weight of the 115 g, as a result, a single made the weight of the entire tube C ₁ to 575 g, compared to the tube described in Patent Document 1, was able to significantly reduce its weight. in this way, after having a required shape holding rigidity and impact resilience as a tube Then, since the first holes 11 are formed in the facing side portions 3 of the tube divided bodies C ₁ a ′ ′ to reduce the weight of the tubes, good ride comfort can be ensured.

In the present invention, the first hole portion 11 formed on each side portion 3 of the tube C ₁ is not limited to a circular described above, may be elliptical, the size (area) and the total number of tubes It is appropriately determined from the viewpoint of achieving weight reduction. The ground portion 1 of the tube C ₁ is without providing the groove in the shape of the ground continuously across the entire length of the annular direction, as shown in FIG. 8, the inside of the ground portion 1, the By forming the through holes 19 in the direction parallel to the one groove 12, it is also possible to reduce the weight.

C ₁ , C ₂ : no punk tube
C ₁ a, C ₂ a: Tube division body
K: Center of tire (axial center)
P: pitch of holes and grooves formed in the tube
T: Tire
1: Tube grounding part
2: Anti-contact portion of the tube
3: Side of tube
4: Hollow part of tube
5: End face of tube segment
11: First hole
12: First groove
13: second hole
14: Second groove
15: Fitting projection
16: Connection piece
16a: Locking projection
17: Fitting groove
18: Locking groove
19: Through hole
51: tire skin
52: Annular space of the tire shell
53: tire rim

Claims (7)

The thermoplastic elastomer has a cross-sectional shape formed by injection molding so as to be slightly larger than the cross-sectional shape of the annular space of the tire shell removably attached to the annular tire rim, so that the whole is annular. A hollow pipe-like no-puncture tube which is formed and fitted into the annular space in a slightly compressed state by tensile stress in all directions of the tire outer skin,
A large number of first holes continuous along the ring direction on each of the opposing side surfaces between the ground portion and the non-ground portion of the tube are continuous at a predetermined pitch in a state where they are opposed along the diameter direction No puncturing tube characterized by being formed.   The non-puncture according to claim 1, wherein a large number of first grooves are continuously formed at a predetermined pitch along the direction orthogonal to the annular direction of the tube in the anti-grounding portion of the tube. tube.   The anti-ground portion of the tube is formed thicker than the other portions, and the first hole and the first groove are formed at the same position along the annular direction of the tube, A plurality of second holes are continuously formed at the same pitch as the first groove along the formation direction of the first groove between the adjacent first grooves in the above. The no-punk tube described in Item 2.   Between the first holes adjacent along the annular direction in the ground portion of the tube, a large number of second grooves having an obtuse triangular cross section are formed along the direction in which the first grooves are formed. The no-puncture tube according to any one of claims 1 to 3, wherein the no-puncture tube is continuously formed at the same pitch.   The non-puncture tube according to any one of claims 1 to 4, wherein a resin hardness (A) of a thermoplastic elastomer which is a molding material of the tube is 93 to 97. The tube is divided into a plurality of tubes along the annular direction, and the ends thereof are connected to each other to form a plurality of tube segments formed in an annular shape,
The no-puncture according to any one of claims 1 to 5, characterized in that both ends of the annular direction of each tube segment are connected in an annular shape as a whole via a connecting portion integrally formed on the tube dividing body. tube.   At one end of the annular direction of the tube segment, a fitting projection to be inserted into and fitted to the hollow portion of another tube segment to be connected is integrally formed. The no-punk tube according to claim 6.

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