JP6178700B2 - Tread ring stiffness measuring apparatus and tread ring uniformity measuring method - Google Patents

Description

  The present invention relates to a tread ring stiffness measuring apparatus and a tread ring uniformity measuring method.

  Conventionally, in the production line of pneumatic tires, various characteristics (eg, RFV, LFV, conicity, etc.) of manufactured tires are inspected before shipment in order to suppress tire vibration during rolling. ing. A pneumatic tire is mounted on a rim for measurement, and various characteristics of uniformity are measured. For example, by rotating a rim equipped with a pneumatic tire, the measurement area that is in contact with the drum or the like of the uniformity measurement device is moved to a different position in the circumferential direction of the pneumatic tire. Is obtained.

  When a load is applied to the pneumatic tire, the measurement area that is in contact with the ground is greatly deformed, and the deformation in the non-measurement area that is not in contact with the ground is small. It depends greatly on the rigidity.

  On the other hand, even in an airless tire comprising a cylindrical tread ring having a ground contact surface, a hub that is arranged radially inside the tread ring and fixed to an axle, and a spoke that connects the tread ring and the hub, Similar to tires, excellent uniformity performance is required. The uniformity of the completed airless tire can be measured in the same way as a pneumatic tire by attaching the hub to the measuring device.

  By the way, in the airless tire, in addition to the eccentricity of the tread ring and the hub, the uniformity of the tread ring alone, that is, the distribution of the longitudinal rigidity in the circumferential direction of the tread ring alone, is considered to affect the uniformity. . Therefore, if the distribution of longitudinal rigidity in the circumferential direction of the tread ring alone can be measured, the uniformity performance of the airless tire can be further enhanced.

  However, when a vertical load is applied to the tread ring to measure the vertical rigidity of the measurement area that is grounded with a single tread ring, the entire tread ring is deformed into an oval shape, unlike the finished airless tire, Each part generates a corresponding stress. For example, in the measurement region and the region immediately above it, compressive stress is generated on the outer peripheral side of the tread ring, and tensile stress is generated on the inner peripheral side. On the other hand, in other regions, tensile stress is generated on the outer peripheral side of the tread ring, and compressive stress is generated on the inner peripheral side. For this reason, in addition to the stress that occurs in the measurement area that is in contact with the ground, the stress that occurs in the non-measurement area that is not in contact with the ground affects the measurement value of the longitudinal rigidity.

  The present invention has been devised in view of the above circumstances, and a tread ring rigidity measuring device capable of measuring only a portion of the rigidity in the circumferential direction of a tread ring alone of an airless tire and a uniform tread ring. Its main purpose is to provide a sex measurement method.

  The present invention relates to an airless comprising a cylindrical tread ring having a grounding surface, a hub that is arranged radially inside the tread ring and fixed to an axle, and a spoke that connects the tread ring and the hub. A tread ring rigidity measuring device for measuring the rigidity of a part of the tread ring used in a tire in the circumferential direction, comprising a support jig for detachably holding the tread ring alone, and the support jig. The tool includes an open part that exposes the measurement region that is a part of the tread ring to the outside so as to be deformable, and a restraint that substantially restrains a non-measurement region that is a region other than the measurement region of the tread ring so as not to be deformable. Part.

  In the tread ring stiffness measurement device according to the present invention, it is preferable that the restraining portion has an outer support portion that abuts the grounding surface of the tread ring in the non-measurement region and restrains the tread ring.

  In the tread ring stiffness measurement apparatus according to the present invention, it is desirable that the outer support portion has a ring-shaped outer ring portion that continuously contacts the ground contact surface of the tread ring in the non-measurement region.

  In the tread ring stiffness measurement device according to the present invention, the restraining portion has an inner support portion that abuts against the inner circumferential surface of the tread ring in the non-measurement region and restrains the tread ring. Is desirable.

  In the rigidity measuring apparatus for a tread ring according to the present invention, it is desirable that the inner support portion has a cylindrical inner ring portion that continuously contacts the inner peripheral surface of the tread ring in the non-measurement region.

  In the tread ring stiffness measuring apparatus according to the present invention, it is preferable that the opening portion of the support jig exposes the tread ring with a chord length in a circumferential direction of 30 to 300 mm.

  In the tread ring stiffness measuring apparatus according to the present invention, a ratio Ji / Ro between the inner diameter Ji of the outer support portion and the outer diameter Ro of the grounding surface of the tread ring is 0.995 to 1.02. It is desirable.

  In the tread ring stiffness measuring apparatus according to the present invention, a ratio Jo / Ri between the outer diameter Jo of the inner support portion and the inner diameter Ri of the inner peripheral surface of the tread ring is 0.99 to 1.03. It is desirable to be.

  Furthermore, the present invention includes a cylindrical tread ring having a ground contact surface, a hub that is arranged radially inside the tread ring and fixed to an axle, and a spoke that connects the tread ring and the hub. A method for measuring the uniformity of the rigidity of the tread ring used in an airless tire in the circumferential direction of the tread ring, wherein a measurement region that is a part of the tread ring in the circumferential direction can be deformed. And a holding step for restraining and holding a non-measurement region other than the measurement region, and a measurement step for measuring a deformation state by applying a load to the measurement region, wherein the measurement region is a circle of the tread ring. The holding step and the measuring step are performed by moving to different positions in the circumferential direction.

  The apparatus for measuring rigidity of a tread ring according to the present invention includes a support jig that removably holds a single tread ring. The support jig includes an open portion that exposes a measurement region that is a part of the circumferential direction of the tread ring to the outside in a deformable manner, and a restraining portion that restrains a non-measurement region other than the measurement region of the tread ring. The rigidity of the tread ring is measured by pressing the contact surface of the measurement area of the tread ring exposed from the open portion against, for example, a drum or a flat plate. At this time, the restraining portion restrains the non-measurement region of the tread ring substantially undeformable. As a result, no stress is generated in the non-measurement region of the tread ring, and the rigidity of only the measurement region that is a part of the circumferential direction of the tread ring alone can be measured.

  The method for measuring uniformity of a tread ring according to the present invention includes a holding step for holding the tread ring and a measuring step for measuring a deformation state of the tread ring. In the holding step, the measurement region which is a part of the tread ring in the circumferential direction can be deformed, and the non-measurement region other than the measurement region is constrained. In the measurement process, a load is applied to the measurement region, and the deformation state is measured. The measurement area is moved to different positions in the circumferential direction of the tread ring, the holding process and the measurement process are performed, and the deformation state over the entire circumference of the tread ring is measured, and the uniformity of the tread ring alone is measured. It becomes possible.

It is a side view which shows one Embodiment of the rigidity measuring apparatus of the tread ring of this invention. It is a perspective view which shows the support jig | tool of the rigidity measuring apparatus of FIG. FIG. 3 is an assembly perspective view of the support jig of FIG. 2. (A) is a side view of the support jig | tool of FIG. 2, (b) is a side view of a tread ring. It is a side view which shows the method of measuring the uniformity of the tread ring of an airless tire using the rigidity measuring apparatus of FIG.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a side view of a tread ring stiffness measuring device (hereinafter, simply referred to as a stiffness measuring device) 1 of an airless tire according to the present embodiment. As shown in FIG. 1, the stiffness measuring device 1 of the present embodiment is a device for measuring the stiffness of a part of the tread ring 100 used in an airless tire in the circumferential direction alone.

  The rigidity measuring apparatus 1 includes, for example, a support jig 2 that holds a single tread ring 100, a flat plate 3 that is pressed against the tread ring 100, and a drive that drives the support jig 2 in the direction of the flat plate 3 (vertical direction). A unit 4; a measuring unit 5 that measures a longitudinal force acting on the flat plate 3; and a processing unit 6 that calculates the rigidity of the tread ring 100 from the force measured by the measuring unit 5. Here, the single tread ring 100 is a tread ring 100 before being integrated with a spoke, a hub, and the like as an airless tire.

  A cylindrical drum or the like may be used instead of the flat plate 3 on which the tread ring 100 is pressed. The drive unit 4 presses the tread ring 100 against the flat plate 3 via the support jig 2, and imparts deformation corresponding to, for example, the amount of vertical deflection of the airless tire to the tread ring 100. The amount of displacement of the support jig 2 by the drive unit 4 is input to the processing unit 6 via the measurement unit 5, for example. The measurement unit 5 may be provided on the drive unit 4 side. The processing unit 6 calculates the longitudinal rigidity of the tread ring 100 based on the displacement of the support jig 2 and the force measured by the measurement unit 5.

  The support jig 2 may be driven in the horizontal direction or the front-rear direction perpendicular to the vertical direction by the drive unit 4. In this case, the measuring unit 5 measures a lateral or front-rear direction force acting on the flat plate 3.

  2 and 3 show the configuration of the support jig 2. The support jig 2 holds the tread ring 100 so as to be removable. The support jig 2 substantially deforms the open portion 21 that exposes the measurement region 100A that is a part of the tread ring 100 to the outside and the non-measurement region 100B that is a region other than the measurement region 100A of the tread ring 100. And a restraining portion 22 for restraining it impossible. When the restraining portion 22 restrains the non-measurement region 100B of the tread ring 100, no stress is generated in the non-measurement region 100B of the tread ring 100, and only the measurement region 100A, which is a part of the tread ring 100 alone in the circumferential direction. Stiffness can be measured.

  The chord length CL in the circumferential direction of the opening 21 that exposes the tread ring 100 is set according to, for example, the contact length of the airless tire to be measured. In general, passenger cars that are easy to drive at high speed and are sensitive to vibrations are required to have better uniformity performance. Therefore, in the present embodiment, the chord length CL is desirably 30 to 300 mm, for example, so as to correspond to the ground contact length of the passenger car tire. When the chord length CL is less than 30 mm, the contact length becomes short, and the rigidity of the tread ring 100 cannot be measured with a sufficient load. On the other hand, when the chord length CL exceeds 300 mm, the tread ring 100 cannot be constrained in a wide range, and the deformation of the non-measurement region 100B may not be sufficiently suppressed.

  The restraint portion 22 is disposed outside the ground contact surface 100C in the non-measurement region 100B of the tread ring 100, and disposed inside the inner peripheral surface 100D in the non-measurement region 100B of the tread ring 100. And an inner support portion 24.

  The outer support portion 23 abuts on the ground contact surface 100C of the tread ring 100 in the non-measurement region 100B and restrains the tread ring 100 from the outside in the radial direction. The outer support portion 23 has a ring-shaped outer ring portion 23A continuously formed in the circumferential direction in the non-measurement region 100B, and an edge portion 23B provided at one end of the outer ring portion 23A.

  The outer ring portion 23A is in contact with the ground contact surface 100C of the tread ring 100 in almost the entire non-measurement region 100B and restrains the tread ring 100 from the outside in the radial direction. As a result, the tread ring 100 is restrained by the outer ring portion 23A in substantially the entire area of the ground contact surface 100C of the non-measurement region 100B, and the non-measurement region 100B is substantially undeformable. The outer support part 23 is not limited to the form shown in FIG. 3 and the like, and may be a form provided intermittently on the outer side in the radial direction of the non-measurement region 100B of the tread ring 100, for example.

  The end edge portion 23B is formed integrally with the outer ring portion 23A and suppresses deformation of the outer ring portion 23A. The tread ring 100 is mounted so that the edge of the tread ring 100 abuts the edge 23B of the outer support 23 in the entire non-measurement region 100B. Thereby, the eccentricity of the tread ring 100 and the outer support part 23 is suppressed. The edge portion 23B has an opening 23C in a region corresponding to the opening portion 21. By providing the opening 23C in the end edge portion 23B, contact between the end edge of the tread ring 100 and the end edge portion 23B of the outer support portion 23 in the measurement region 100A is avoided, and deformation of the measurement region 100A is hindered. There is nothing. The inner support portion 24 is coupled to the end edge portion 23B. A pair of alignment portions 23D for aligning the relative positions of the outer support portion 23 and the inner support portion 24 project from the end edge portion 23B.

  4A shows a side surface of the support jig 2, and FIG. 4B shows a side surface of the tread ring 100 before being attached to the support jig 2. FIG. By connecting the outer support portion 23 and the inner support portion 24 at an appropriate relative position, a groove portion 27 is formed between the outer support portion 23 and the inner support portion 24. The non-measurement region 100 </ b> B of the tread ring 100 is attached to the groove portion 27 and is restrained by the outer support portion 23 and the inner support portion 24.

  The ratio Ji / Ro between the inner diameter Ji of the outer ring portion 23A of the outer support portion 23 and the outer diameter Ro of the ground contact surface 100C of the tread ring 100 is desirably 0.995 to 1.02.

  When the ratio Ji / Ro is less than 0.995, it is difficult to mount the tread ring 100 on the inner side of the outer ring portion 23A of the outer support portion 23. On the other hand, when the ratio Ji / Ro exceeds 1.02, the gap between the ground contact surface 100C of the tread ring 100 and the inner peripheral surface of the outer ring portion 23A of the outer support portion 23 is increased, and the non-measurement region 100B of the tread ring 100 is increased. There is a possibility that the deformation of the material cannot be sufficiently suppressed.

  As shown in FIG. 2, the inner support portion 24 abuts on the inner peripheral surface 100D of the tread ring 100 in the non-measurement region 100B and restrains the tread ring 100 from the inner side in the radial direction. The inner support portion 24 has a cylindrical inner ring portion 24A formed continuously in the circumferential direction. The inner ring portion 24A comes into contact with the inner peripheral surface 100D of the tread ring 100 in the non-measurement region 100B and restrains the tread ring 100 from the inside in the radial direction. Thereby, the tread ring 100 is restrained by the inner ring portion 24A in almost the entire inner peripheral surface 100D of the non-measurement region 100B, and deformation of the non-measurement region 100B is further effectively suppressed.

  As shown in FIG. 3, the inner ring portion 24 </ b> A has an opening 24 </ b> C in a region corresponding to the opening portion 21. By providing the opening 24C in the inner ring portion 24A, contact between the edge of the tread ring 100 and the inner ring portion 24A of the inner support portion 24 in the measurement region 100A is avoided, and deformation of the measurement region 100A is hindered. Absent. The inner support part 24 is not limited to the form shown in FIG. 3 and the like, and may be a form provided intermittently inside the non-measurement region 100B of the tread ring 100, for example.

  The inner support portion 24 is coupled to the end edge portion 23B of the outer support portion 23 by a bolt 25 or the like. The bolt 25 is mounted from a hole 28 provided in the end surface of the inner ring portion 24 </ b> A of the inner support portion 24. A handle portion 26 for holding the support jig 2 is provided on the end face of the inner ring portion 24A of the inner support portion 24 as necessary. An end face of the inner ring portion 24A of the inner support portion 24 may be provided with a flange portion that comes into contact with the end edge of the tread ring 100 as necessary. The tread ring 100 is accurately positioned in the support jig 2 by the flange portion and the end edge portion 23B of the outer support portion 23, and the axial displacement of the tread ring 100 is prevented.

  As shown in FIG. 4, the ratio Jo / Ri between the outer diameter Jo of the inner ring portion 24A of the inner support portion 24 and the inner diameter Ri of the inner peripheral surface 100D of the tread ring 100 is preferably 0.99 to 1.03. .

  When the ratio Jo / Ri is less than 0.99, the gap between the inner peripheral surface 100D of the tread ring 100 and the outer peripheral surface of the inner ring portion 24A of the inner support portion 24 becomes large, and the non-measurement region 100B of the tread ring 100 is deformed. May not be sufficiently suppressed. On the other hand, when the ratio Jo / Ri exceeds 1.03, it is difficult to mount the tread ring 100 on the outer side of the inner ring portion 24A of the inner support portion 24.

  FIG. 5 shows a method of measuring the uniformity of the tread ring 100 of the airless tire using the stiffness measuring device 1. The method for measuring the uniformity of the tread ring 100 includes a holding step for holding the tread ring 100 and a measuring step for measuring the deformation state of the tread ring 100.

  As shown in FIG. 5A, in the holding process, the tread ring 100 is held using the support jig 2. That is, in the tread ring 100, the non-measurement region 100B other than the measurement region 100A is restrained and held by the restraining portion 22 of the support jig 2. At this time, the measurement region 100A, which is a part in the circumferential direction, is opened by the opening 21 of the support jig 2 so as to be deformable.

  As shown in FIG. 5B, in the measurement process, the support jig 2 driven by the drive unit 4 is displaced toward the flat plate 3, that is, in the direction of the arrow A1, and the measurement region 100A of the tread ring 100 is measured. Is given a load. At this time, since the non-measurement region 100B is restrained so as not to be deformed by the restraining portion 22 of the support jig 2, only the measurement region 100A is deformed to generate stress. In this measurement process, the deformation state of the tread ring 100 is measured by the amount of displacement of the support jig 2 and the force acting on the flat plate 3.

  Thereafter, as shown in FIG. 5C, the support jig 2 is displaced in the direction opposite to the flat plate 3, that is, in the direction of the arrow A <b> 2, and the tread ring 100 is separated from the flat plate 3. Further, the tread ring 100 is rotated with respect to the support jig 2 in the circumferential direction of the tread ring 100, for example, in the direction of arrow B. Thereby, the measurement area 100A is shifted by the rotation angle, and a new measurement area 100A is set. That is, the measurement region 100A is moved to a different position in the circumferential direction of the tread ring 100. When it is difficult to rotate the tread ring 100 due to friction between the tread ring 100 and the outer support portion 23 and the inner support portion 24, the inner support portion 24 is separated from the outer support portion 23, and the tread ring 100 is moved. It may be shifted. Thereafter, the deformation state over the entire circumference of the tread ring 100 is measured by repeating the steps of FIGS.

  The tread ring stiffness measuring apparatus and the tread ring uniformity measuring method according to the present invention have been described in detail above. However, the present invention is not limited to the specific embodiments described above, and various modifications can be made. To be implemented.

   A tread ring stiffness measuring apparatus having the support jig of the embodiment having the basic structure shown in FIG. 2 was prototyped, and the longitudinal stiffness of the tread ring alone was measured. In the comparative example, the longitudinal rigidity of the tread ring alone was measured without using a support jig. In measuring the longitudinal rigidity, loads corresponding to 50%, 100%, and 120% of the load index of the equivalent pneumatic tire were applied from the specifications of the airless tire, for example, the dimensions such as the outer diameter and the width.

Evaluation “S” in the determination of whether or not rigidity can be measured indicates a case where only the measurement region is deformed and the longitudinal rigidity is measured. The evaluation “A” indicates a case where a part of the non-measurement region is slightly deformed, but it is considered that most of the measured longitudinal rigidity is derived from the rigidity of the measurement region. The evaluation “B” indicates a case where only the measurement region is deformed and the longitudinal rigidity thereof is measured, but the tread ring attaching / detaching operation is difficult. Evaluation “C” indicates the case where the deformation of the tread ring is insufficient and the longitudinal rigidity cannot be measured with the set load. Evaluation “D” indicates a case where almost the entire region of the tread ring is deformed, and the measured longitudinal rigidity is considered to be affected by a considerable proportion of the rigidity of the non-measurement region.

  As can be seen from Table 1, it was confirmed that the rigidity measuring device of the tread ring of the example can accurately measure the rigidity of the measurement region as compared with the comparative example.

DESCRIPTION OF SYMBOLS 1 Stiffness measuring apparatus 2 Support jig 3 Flat plate 21 Opening part 22 Restraint part 23 Outer support part 23A Outer ring part 24 Inner support part 24A Inner ring part 100 Tread ring 100A Measurement area 100B Non-measurement area

Claims (9)

Used in an airless tire including a cylindrical tread ring having a contact surface, a hub that is arranged radially inside the tread ring and fixed to an axle, and a spoke that connects the tread ring and the hub. A tread ring stiffness measuring device for measuring the stiffness of a portion of the tread ring alone in the circumferential direction,
Including a support jig for detachably holding the tread ring alone;
The support jig is an open portion that exposes the measurement region that is the part of the tread ring to the outside in a deformable manner,
A tread ring stiffness measuring device comprising: a restraining portion that restrains a non-measuring region that is a region other than the measuring region of the tread ring so as to be substantially undeformable.   2. The tread ring stiffness measurement device according to claim 1, wherein the restraining portion includes an outer support portion that abuts the grounding surface of the tread ring in the non-measurement region and restrains the tread ring.   The tread ring stiffness measurement device according to claim 2, wherein the outer support portion has a ring-shaped outer ring portion that continuously contacts the ground contact surface of the tread ring in the non-measurement region.   4. The tread ring stiffness measurement device according to claim 1, wherein the restraining portion includes an inner support portion that abuts on a radially inner circumferential surface of the tread ring and restrains the tread ring in the non-measurement region.   The tread ring stiffness measurement device according to claim 4, wherein the inner support portion includes a cylindrical inner ring portion that continuously contacts the inner peripheral surface of the tread ring in the non-measurement region.   6. The tread ring stiffness measurement device according to claim 1, wherein the opening portion of the support jig exposes the tread ring with a chord length in a circumferential direction of 30 to 300 mm.   3. The tread ring stiffness measurement device according to claim 2, wherein a ratio Ji / Ro between an inner diameter Ji of the outer support portion and an outer diameter Ro of the grounding surface of the tread ring is 0.995 to 1.02.   5. The tread ring stiffness measurement device according to claim 4, wherein a ratio Jo / Ri between an outer diameter Jo of the inner support portion and an inner diameter Ri of the inner peripheral surface of the tread ring is 0.99 to 1.03. Used in an airless tire including a cylindrical tread ring having a contact surface, a hub that is arranged radially inside the tread ring and fixed to an axle, and a spoke that connects the tread ring and the hub. A tread ring uniformity measurement method for examining the rigidity uniformity in the circumferential direction of the tread ring alone,
A holding step for deforming a measurement region that is a part of the circumferential direction of the tread ring and holding and holding a non-measurement region other than the measurement region;
Measuring the deformation state by applying a load to the measurement region,
A method for measuring the uniformity of a tread ring of an airless tire, wherein the holding step and the measuring step are performed by moving the measurement region to different positions in the circumferential direction of the tread ring.

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