Method for manufacturing a travel drum and travel drum

Abstract

To provide a method of manufacturing a running drum and a running drum capable of accurately testing the tire performance.SOLUTION: A method of manufacturing a running drum includes the steps of: installing, on a drum body 20, a formwork 4 including a pair of circumferential frames 41 extending in a drum circumferential direction and spaced apart from each other in a drum axial direction, and an axial frame 42 which divides a molding space S sandwiched between the pair of circumferential frames 41 in the drum circumferential direction; and filling a composition constituting the pseudo road surface into the molding space divided by the axial frame 42 and curing the composition. The installation locations of the axial frame 42 are set with different circumferential pitches, and the maximum value of the circumferential pitches is less than twice the minimum value.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] This disclosure relates to a method for manufacturing a running drum used in tire performance testing, and to a running drum. [Background technology]

[0002] Traditionally, bench tests have been conducted indoors to evaluate tire performance, such as noise and axial force. These bench tests generally utilize a bench testing apparatus that has a running drum equipped with a cylindrical simulated road surface and a drum body that supports the simulated road surface.

[0003] Patent documents 1 and 2 describe a method for manufacturing a running drum, in which an uncured composition is filled into a molding space within a mold installed on the outer surface of the drum body, and a simulated road surface is formed by curing the composition. The molding space is divided into sections of appropriate length in the circumferential direction of the drum to prevent the filled composition from flowing out. Therefore, the filling and curing of the composition are repeated while shifting the position of the molding space in the circumferential direction of the drum, thereby forming a cylindrical simulated road surface. Consequently, multiple seams of the composition are formed on the simulated road surface in the circumferential direction of the drum.

[0004] When tires are driven on such a simulated road surface, inputs caused by the joints occur at regular intervals, which may lead to an increase in frequency components such as vibrations, potentially negatively impacting the accuracy of tire performance tests, including noise and axial force. Patent documents 1 and 2 suggest, as a countermeasure, that when installing the axial frames that form the joints, the distance between adjacent axial frames in the circumferential direction of the drum be varied, but no specific form suitable for this is disclosed. Furthermore, simply varying the distance between adjacent axial frames in the circumferential direction of the drum may not yield sufficient improvement. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2017-138158 [Patent Document 2] Japanese Patent Publication No. 2015-135289 [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] This disclosure is made in view of the above circumstances, and its purpose is to provide a method for manufacturing a running drum and a running drum that can accurately test tire performance. [Means for solving the problem]

[0007] The present disclosure is a method for manufacturing a running drum, comprising a cylindrical pseudo-road surface and a drum body supporting the pseudo-road surface, wherein the method includes the steps of installing a mold on the drum body or a mounting member detachably configured on the drum body, the mold including a pair of circumferential frames extending in the circumferential direction of the drum and arranged at a distance from each other in the axial direction of the drum, and an axial frame that divides the molding space sandwiched between the pair of circumferential frames in the circumferential direction of the drum, and filling the molding space divided by the axial frame with a composition constituting the pseudo-road surface and hardening it, wherein the installation locations of the axial frames are set to have different circumferential pitches, and the maximum value of the circumferential pitch is less than twice the minimum value.

[0008] The travel drum of this disclosure comprises a cylindrical pseudo-road surface and a drum body supporting the pseudo-road surface, wherein the pseudo-road surface has multiple joints of composition formed in the circumferential direction of the drum, and the locations where the joints are formed are set to have different circumferential pitches, and the maximum value of the circumferential pitch is less than twice the minimum value. [Brief explanation of the drawing]

[0009] [Figure 1] A schematic diagram showing an example of a bench-mounted test apparatus with a traveling drum. [Figure 2] Schematic diagram showing the traveling drum as viewed from the drum axis direction. [Figure 3] Perspective view of the drum body with the formwork installed [Figure 4] (A) Plan view development diagram of the drum body during the installation process, and (B) Plan view development diagram of the drum body during the first filling process [Figure 5] (A) Plan view development diagram of the drum body during the removal process, and (B) Plan view development diagram of the drum body during the second filling process [Figure 6] Development diagram schematically showing one turn of the formwork [Figure 7] Development diagram showing a modification example of the circumferential pitch of the installation position of the axial frame [Figure 8] Schematic diagram showing a modification example of the formwork [Figure 9] Schematic diagram showing a modification example of the formwork [Figure 10] Schematic diagram showing a modification example of the formwork [Figure 11] Schematic diagram showing a modification example of the formwork [Figure 12] Development diagram schematically showing a part of the formwork [Figure 13] Schematic diagram showing a modification example of the formwork [Figure 14] Schematic diagram showing a modification example of the formwork [Figure 15] Schematic diagram showing a modification example of the formwork [Figure 16] Schematic diagram showing a modification example of the formwork [Figure 17] Perspective view showing an example of the mounting member

Embodiment for Carrying out the Invention

[0010] First, a brief explanation will be given of the configuration of a bench test apparatus having a running drum. Figure 1 shows an example of a bench test apparatus used for testing tire performance such as noise. The bench test apparatus 1 shown in Figure 1 has a running drum 2 on which a tire T is pressed against its outer surface. The running drum 2 is rotatably supported by a horizontally extending drum rotation shaft 11. A drum power source 12, such as a motor that rotates the running drum 2, is connected to the drum rotation shaft 11. A simulated road surface 3 is provided on the outer surface of the running drum 2. The tire T pressed against the outer surface of the running drum 2 is in contact with the simulated road surface 3.

[0011] The tire T is rotatably supported by a horizontally extending tire rotation shaft 13. A tire power source 14, such as a motor, which can apply driving or braking force to the tire rotation shaft 13, is connected to the tire rotation shaft 13. The tire power source 14 may be a brake to apply braking force, or a motor and brake may be used in combination. A load cell 15 for measuring torque and longitudinal force of the tire T, and a fixing member 16 for fixing the tire rotation shaft 13 in the pressing direction (up and down direction in Figure 1) are attached to the tire rotation shaft 13.

[0012] The bench testing apparatus 1 includes a lifting device 17 as a pressing means for pressing the tire T against the travel drum 2. The lifting device 17 raises and lowers the tire power source 14. This allows the tire T, which is attached to the tire rotation shaft 13, to be moved closer to or further away from the travel drum 2. A lifting device configured to raise and lower the travel drum 2 may also be used as the pressing means. Based on the measurement results from the load cell 15, the load on the tire T is adjusted to a predetermined value by the lifting device 17, and then the tire rotation shaft 13 is fixed with the fixing member 16, thereby allowing the tire T to be brought to ground with a predetermined load.

[0013] The bench-mounted testing apparatus 1 includes a control unit 18 that controls the operation of the bench-mounted testing apparatus 1. The control unit 18 can be configured using a computer such as a personal computer or a PLC (programmable logic controller). The control unit 18 is electrically connected to the drum power source 12, the tire power source 14, the load cell 15, the fixing member 16, and the lifting device 17, and is configured to control the operation of each of these parts.

[0014] Figure 2 shows the running drum 2 as viewed from the drum axis direction (direction along the drum rotation axis 11). The running drum 2 comprises a cylindrical simulated road surface 3 and a drum body 20 that supports the simulated road surface 3. The tire T used for testing is pressed against the simulated road surface 3 provided on the outer circumference of the running drum 2. The simulated road surface 3 is constructed, for example, according to the particle size curve of the ISO road surface standard (see the allowable particle size curve range for asphalt mixtures described in Annex C of ISO 10844, design guidelines).

[0015] In this embodiment, the simulated road surface 3 is formed by curing a composition prepared by mixing aggregate and a binder. For example, the aggregate has a maximum aggregate particle size of 8 mm (tolerance range is 6.3 mm to 10 mm), and the target particle size curve of the aggregate is within the range of the ISO road surface standard particle size curve. A mixture of coarse aggregate, fine aggregate and filler is used accordingly. For the binder, for example, a known synthetic resin is used, but epoxy resin is preferably used from the viewpoint of ensuring bonding strength with the aggregate and bonding strength with the outer surface of the drum body 20. Although not shown in Figure 2, the simulated road surface 3 has multiple joints of the composition formed in the circumferential direction of the drum.

[0016] Next, a method for manufacturing the travel drum will be described. The manufacturing method for the travel drum 2 in this embodiment comprises an installation step, a first filling step, a removal step, and a second filling step. By going through these steps, a simulated road surface 3 can be provided on the drum body 20, thereby manufacturing the travel drum 2 shown in Figures 1 and 2.

[0017] As a method for manufacturing the traveling drum 2, first a drum body 20 is prepared. The drum body 20 is held so as to be rotatable, for example, with the drum axis direction horizontal. Next, as shown in Figure 3, a mold frame 4 is installed on the drum body 20 (installation step). The mold frame 4 protrudes outward from the outer peripheral surface of the drum body 20 in the drum radial direction. The mold frame 4 includes a pair of circumferential frames 41 and an axial frame 42. The pair of circumferential frames 41 extend in the drum circumferential direction and are arranged at a distance from each other in the drum axis direction. The axial frame 42 divides the molding space S, which is sandwiched between the pair of circumferential frames 41, in the drum circumferential direction.

[0018] Figure 4(A) is a plan view of the drum body 20, with the drum's central axis 2C indicated by a dashed line. The axial frame 42 extends along the drum axis so as to connect a pair of circumferential frames 41. The molding space S, sandwiched between the pair of circumferential frames 41, is divided into multiple molding spaces S1, S2, S3, etc. by multiple axial frames 42 arranged at intervals in the circumferential direction of the drum. While it is desirable to increase the circumferential length of each molding space S1, S2, S3, etc. in the drum direction from the viewpoint of reducing the number of seams, if it is too large, the uncured composition will flow out. Therefore, the spacing of the axial frames 42 is determined appropriately, taking these factors into consideration.

[0019] Next, as shown in Figure 4(B), the uncured composition 5 constituting the pseudo-road surface 3 is filled into the molding space S1 separated by the axial frame 42 and cured (first filling step). To prevent the filled uncured composition 5 from flowing out, the molding space S1 into which the composition 5 is filled is initially positioned upwards (around the 12 o'clock position when viewed from the drum axis direction). In this embodiment, the circumferential frame 41 is formed in an annular shape along the circumferential direction of the drum. However, it is not limited to this, and the circumferential frame 41 only needs to be positioned within a range that includes the molding space (molding space S1 in Figure 4(B)) into which the uncured composition 5 is filled.

[0020] As shown in Figure 5(A), after the filled composition 5 has hardened, the axial frame 42 in contact with the composition 5 is removed (removal step). This exposes the end face 5e of the composition 5 that was in contact with the side wall surface (the surface facing the circumferential direction of the drum) of the axial frame 42. The shape of the exposed end face 5e in a view in the radial direction of the drum (for example, a plan view) corresponds to the shape of the axial frame 42 that was in contact with that end face 5e. This removal step may be performed before the composition 5 has completely hardened, provided that the composition 5 has hardened to the extent that the shape of the end face 5e does not deteriorate significantly (to the extent that it does not deform under gravity).

[0021] After the removal process, as shown in Figure 5(B), the uncured composition 5 constituting the pseudo-road surface 3 is filled into the molding space S2 opposite to the end face 5e of composition 5 that was in contact with the removed axial frame 42 and cured (second filling process). The molding space S2 into which composition 5 is filled is positioned above in advance to prevent the uncured composition 5 from flowing out. At this stage, one side of the molding space S2 in the drum circumferential direction is separated by the axial frame 42, and the other side is separated by the end face 5e of composition 5. The composition 5 filled into the molding space S2 adheres to the composition 5 that has been filled into the molding space S1 and cured, and a joint 50 is formed between them.

[0022] After the composition 5 filled into the molding space S2 has hardened, the axial frame 42 in contact with the composition 5 is removed. Then, the unhardened composition 5 is filled into the molding space S3 opposite the end face of the composition 5 that has been exposed and hardened. This is done in the same manner as filling and hardening the composition 5 into the molding space S2. Thus, the second filling step becomes the first filling step in the next molding cycle, and thereafter the removal step and the (second) filling step are repeated. A cylindrical pseudo-road surface 3 is formed by connecting a full circumference of composition 5 along the circumferential direction of the drum.

[0023] As shown in Figure 5, the length of the composition 5 filled into the molding space S2 is the length of the molding space S2 divided by the axial frame 42 plus the thickness of the axial frame 42, and the same applies to the molding spaces S3 and beyond. Therefore, the circumferential pitch of the locations where the seams 50 are formed corresponds to the circumferential pitch of the locations where the axial frame 42 is installed. However, the length of the composition 5 that is initially filled is equal to the length of the molding space S1, and the seams 50 formed on the end face 5e of the composition 5 are shifted by the thickness of the axial frame 42. Therefore, with respect to the circumferential pitch of the locations where the axial frame 42 is installed, the length of the composition 5 that is initially filled becomes shorter by the thickness of the axial frame 42, and the length of the composition 5 that is last filled becomes longer by the thickness of the axial frame 42.

[0024] Figure 6 is a schematic unfolded view showing a mold 4 that extends around the drum in the circumferential direction. In Figure 6, the vertical direction corresponds to the drum axis direction, and the horizontal direction corresponds to the drum circumferential direction (the same applies to Figure 7). In this embodiment, the molding space S, which is sandwiched between a pair of circumferential frames 41, is divided into nine molding spaces S1 to S9 by an axial frame 42. In other words, the axial frame 42 is set to be installed at nine locations in the drum circumferential direction. The circumferential pitches P2 to P8 of the installation locations of the axial frame 42 each have a length that is the drum circumferential length of each molding space S2 to S8 plus the thickness of one axial frame 42. The circumferential pitch P1 has a length that corresponds to the drum circumferential length of molding space S1, and the circumferential pitch P9 has a length that is the drum circumferential length of molding space S9 plus the thickness of two axial frames 42.

[0025] In this embodiment, the installation locations of the axial frame 42 are set with different circumferential pitches. Furthermore, the maximum value of the circumferential pitch (PL, described later) N The PL9 is less than twice the minimum value (PL1, described later), and preferably less than 1.9 times. This disperses the frequency components caused by the joint 50, suppressing adverse effects on the test accuracy of tire performance such as noise and axial force. Moreover, by setting the maximum value of the circumferential pitch to less than twice the minimum value, it is possible to avoid the frequency of the component that is twice the minimum circumferential pitch matching the frequency of the maximum circumferential pitch, thereby obtaining a sufficient improvement effect.

[0026] In FIG. 6, the lengths of the circumferential pitches P1 to P9 at the installation positions of the axial frame 42 are classified by type, and they are arranged in ascending order as PL1, PL2, PL3 ··· PL N is. The minimum value of the circumferential pitch is PL1, and the maximum value is P N is. FIG. 6 is an example where N = 9. When classifying by type, if the lengths of the circumferential pitches are the same as each other, or if the difference in length is less than 4 mm, they are regarded as the same type (see FIG. 7 described later). Therefore, the smallest of the lengths of the circumferential pitches P1 to P9 becomes PL1, and the smallest of the lengths with a difference of 4 mm or more from it becomes PL2, and the classification is made in the same manner thereafter.

[0027] As described above, the lengths of the circumferential pitches P1 to P9 are classified by type, and they are arranged in ascending order as PL1, PL2, ··· PL N when, PL k (however, k = 1 to N - 1) and PL k+1 is preferably 0.2% or more of the circumferential length of the drum body 20. Thereby, the circumferential pitches at the installation positions of the axial frame 42 can be appropriately made different, and the dispersion effect of the frequency components caused by the joint 50 can be ensured well. From the viewpoint of enhancing such an effect, PL k and PL k+1 is more preferably 0.4% or more of the circumferential length of the drum body 20, and even more preferably 0.6% or more.

[0028] The maximum value of the circumferential pitch at the installation position of the axial frame 42 (that is, PL N ) is preferably 15% or less of the circumferential length of the drum body 20, and more preferably 12% or less. Thereby, it is possible to avoid the circumferential pitch becoming excessively large, which is convenient for preventing the uncured composition 5 filled in the molding space from flowing down.

[0029] In this embodiment, an example is shown in which the molding space S has nine divisions. Although this number of divisions is not particularly limited, the circumference of the drum body 20 is set to the maximum value of the circumferential pitch of the installation locations of the axial frame 42 (i.e., PL N It is preferable that the number obtained by dividing by (however, rounding up to the nearest whole number) is used. This minimizes the number of divisions in the molding space S within a practical range, and consequently reduces the number of seams 50. From the viewpoint of minimizing the decrease in the accuracy of tire performance testing, it is desirable to have as few seams 50 as possible.

[0030] In Figure 6, the circumferential pitches P1 to P9 at the installation locations of the axial frame 42 are all different from each other. Therefore, the number of circumferential pitch lengths PL1 to PL9, categorized by type, is nine, the same as the circumferential pitches P1 to P9. In other words, the number of types of circumferential pitch lengths is the same as the number of divisions in the molding space S, which is nine in this embodiment. This allows for a more favorable improvement of the dispersion effect of frequency components caused by the seams 50. Note that there should be at least two types of circumferential pitch lengths, preferably three or more, but it is even more preferable that the number of types is the same as the number of divisions in the molding space S, as described above.

[0031] Figure 7 shows a modified example regarding the circumferential pitch of the installation locations of the axial frame 42. Figure 7(A) is an example where there are three different lengths for the circumferential pitch, and N=3. In this formwork 4, the installation locations of the axial frame 42 are set up so that the combination of lengths PL1, PL2, and PL3 is repeated. Figure 7(B) is an example where there are two different lengths for the circumferential pitch, and N=2. In this formwork 4, the installation locations of the axial frame 42 are set up so that lengths PL1 and PL2 are alternating.

[0032] As shown in Figures 6 and 7(A), it is preferable that at each installation location of the axial frame 42, circumferential pitches of different lengths are adjacent to each other in the circumferential direction of the drum. This allows for a more favorable improvement of the dispersion effect of frequency components caused by the joints 50. However, this is not limited to this, and as shown in Figure 7(B), a pair of circumferential pitches of the same length (P9 and P1 in Figure 7(B)) may be adjacent to each other in the circumferential direction of the drum in a part of the circumferential direction of the drum (for example, one or two locations in the circumferential direction of the drum).

[0033] As an example, one embodiment is conceivable in which the lengths of the circumferential pitch at the installation locations of the axial frame 42 are classified into types, and when these are arranged in ascending order, an arithmetic or geometric progression relationship is established. Such an embodiment is particularly useful when there are preferably three or more types of circumferential pitch lengths. More preferably, it is particularly useful when all the circumferential pitches are different from each other. If the lengths of the circumferential pitches are determined haphazardly, it is possible that only similar frequencies will be generated, whereas by using such a sequence, the frequencies can be shifted in a planned manner.

[0034] In the examples shown in Figures 6 and 7, the axial frame 42 extends parallel to the drum axis direction, but it is not limited to this. For example, as shown in Figure 8, the axial frame 42 may have an inclined portion 42s that extends diagonally with respect to the drum axis direction. With such a configuration, the joints 50 of the composition 5 formed on the simulated road surface 3 (see Figure 5(B)) will have an inclined portion that extends diagonally with respect to the drum axis direction. This allows for more accurate testing of tire performance, in addition to the dispersion effect of frequency components caused by the joints 50, as well as the improvement effects described later.

[0035] By forming a joint 50 with the inclined portion described above, when the tires are driven on the simulated road surface 3, it is suppressed that the pressing side of the tire contact surface collides with the joint simultaneously, or that the pushing side of the tire contact surface detaches from the joint simultaneously. For example, in the case of a joint 50 formed by the axial frame 42 shown in Figure 8, the timing of the pressing side of the tire contact surface colliding with the joint will differ between one side and the other side in the direction of the drum axis. This prevents large inputs caused by the tire contact surface colliding with or detaching from the joint 50 simultaneously, allowing for accurate testing of tire performance such as noise and axial force.

[0036] The angle θ on the acute side of the axial frame 42 having the inclined portion 42s with respect to the drum axis is preferably 30 to 60 degrees. The angle θ is determined based on a straight line connecting both ends of the axial frame 42. When the angle θ exceeds 30 degrees, the effect of preventing large inputs caused by the joints 50 as described above is more effectively achieved. Also, when the angle θ is less than 60 degrees, the drum circumferential length L of the molding space (molding space S1, etc.) separated by the axial frame 42 does not become too large, and the number of joints 50 is reduced. The relationship between the length L of the molding space and the number of joints 50 will be explained later.

[0037] The axial frame 42 shown in Figure 8 has an inclined portion 42s along its entire length in the direction of the drum axis. However, it is not limited to this, and for example, as shown in Figures 9(A) to (C), the axial frame 42 may not have an inclined portion 42s in a part of its length in the direction of the drum axis. However, it is preferable that the inclined portion 42s is set in a region that includes a range 41r of 30% of the distance 41a between the pair of circumferential frames 41, centered on the intermediate position 41c of the pair of circumferential frames 41, and more preferably in a region that includes the range of the maximum tire contact width that can be tested by the bench test device 1. This is because it is assumed that the tire T will be in contact with the central part of the simulated road surface 3 (see Figure 1).

[0038] In the example shown in Figure 8, the inclined portion 42s is formed in a straight line, and as a result, the axial frame 42 is also formed in a straight line overall. However, this is not the only option, and various shapes can be used for the inclined portion 42s and the axial frame 42 having it. For example, the inclined portion 42s may be formed in a straight line, curved line, bent line, zigzag line, or a combination of these shapes when viewed in the radial direction of the drum. Modified examples of the axial frame 42 will be described with reference to Figures 9 to 11.

[0039] In Figure 9, at least one end of the axial frame 42 extends substantially parallel to the drum axis direction. This allows for a smaller molding space length L (see Figure 8) compared to the case where the inclined portion 42s is extended to the end. The molding space partitioned by the axial frame 42 needs to be of an appropriate length to prevent the filled composition 5 from flowing out. If the molding space becomes excessively long, the spacing between the axial frames 42 must be reduced. However, this increases the number of partitions by the axial frame 42, and consequently, the number of seams 50. Therefore, by not making the molding space excessively long, the number of seams 50 can be kept down.

[0040] In Figure 9(A), one end of the axial frame 42 extends parallel to the drum axis, and in Figure 9(B), both ends of the axial frame 42 extend parallel to the drum axis. These ends are connected to the inclined portion 42s via inflection points 42p. The axial frame 42 in Figure 9(B) is formed in a crank shape (an example of a bent line shape) when viewed radially from the drum. The inclined portion 42s in Figure 9(C) has the same shape as in Figure 9(B), except that it is formed in a zigzag line shape when viewed radially from the drum. The axial frame 42 shown in Figure 9 has one or more inflection points 42p.

[0041] In the example shown in Figure 10, the inclined portion 42s is formed in a curved shape when viewed in the radial direction of the drum. In Figure 10(A), the inclined portion 42s is formed in an arc shape without an inflection point. In Figure 10(B), the inclined portion 42s is formed in an S-shape with one inflection point. As a modification, the inclined portion 42s may be formed in a curved shape with multiple inflection points. In Figure 10(C), one end of the axial frame 42, and in Figure 10(D), both ends of the axial frame 42, are formed in a straight line substantially parallel to the drum axis direction.

[0042] In the example shown in Figure 11, the inclined portion 42s is formed in a V-shape or U-shape when viewed in the radial direction of the drum. In Figure 11(A), the inclined portion 42s is formed in a V-shape by combining two straight lines. In Figure 11(B), the inclined portion 42s is formed in a V-shape by combining two curves (arcs). In Figure 11(C), the inclined portion 42s is formed in a U-shape. As a variation of these, at least one end of the axial frame 42 may extend substantially parallel to the drum axis direction.

[0043] In Figures 12-16, the shapes of the axial frames 42 installed adjacent to each other in the circumferential direction of the drum are different when viewed in the radial direction of the drum. For example, axial frame 42A and the adjacent axial frame 42B have different shapes. Similarly, axial frame 42B and the adjacent axial frame 42C have different shapes. As a result, the circumferential pitch of the installation locations of the axial frames 42 changes in the axial direction of the drum, and the dispersion effect of frequency components caused by the joints 50 is enhanced.

[0044] The axial frame 42 shown in Figure 12 extends at an inclination with respect to the drum axis direction. In this example, the inclination directions of the axial frames 42 installed adjacent to each other in the circumferential direction of the drum are different from those of the drum axis direction, thereby making their shapes different when viewed in the radial direction of the drum. The inclination angle θ of the axial frames 42 with respect to the drum axis direction is the same for all of them, but as will be described later, it is possible to make the inclination angle θ different in place of or in addition to the direction of inclination.

[0045] The axial frame 42 shown in Figure 13 extends at an inclination with respect to the drum axis direction. In this example, the angle θ of inclination with respect to the drum axis direction is made different for axial frames 42 installed adjacent to each other in the circumferential direction of the drum, thereby making their shapes different when viewed in the radial direction of the drum. The direction of inclination of the axial frames 42 with respect to the drum axis direction is the same for all of them, but the angle θ may be different, and the direction of inclination may also be different as shown in Figure 12. In other words, it is possible to make both the direction of inclination and the angle θ of axial frames 42 installed adjacent to each other in the circumferential direction of the drum different, which is convenient for increasing the variations in the shape of the axial frame 42.

[0046] Figure 14 shows an example where the axial frame 42 is formed in a curved shape when viewed radially from the drum, and all of the axial frames 42 extend at an inclination with respect to the drum axis. In Figure 14(A), the direction of inclination of the axial frames 42 with respect to the drum axis is different from each other. In Figure 14(B), the angle of inclination of the axial frames 42 with respect to the drum axis is different. Instead of or in addition to the direction and angle of inclination, the direction of curvature or curvature may also be different. In Figure 14(C), the number of inflection points of the axial frame 42 is different.

[0047] Figure 15 shows examples where the axial frame 42 is formed in a bent or zigzag shape when viewed radially from the drum, and in all cases, the axial frame 42 extends at an inclination with respect to the drum axis. In Figure 15(A), the direction of inclination of the axial frame 42 with respect to the drum axis is different from each other. In Figure 15(B), the angle of inclination of the axial frame 42 with respect to the drum axis is different. In Figure 15(C), the number of inclination points of the axial frame 42 is different.

[0048] In Figure 16(A), linear, curved, and zigzag axial frames 42 are used in combination. In Figure 16(B), the axial frames 42 are formed in a V-shape or U-shape when viewed in the radial direction of the drum. The axial frame 42D is formed in a V-shape by combining two straight lines. The axial frame 42E is formed in a V-shape by combining two curves (arcs). The axial frame 42F is formed in a U-shape.

[0049] Examples of materials for the formwork 4 include elastic materials such as rubber, metals such as aluminum alloys, resins (plastics), ceramics, and wood, but are not particularly limited. The circumferential frame 41 may be made of the same material as the axial frame 42, or it may be made of a different material. When the circumferential frame 41 and / or the axial frame 42 are made of an elastic material such as rubber, there is an advantage in that they can be curved to match the curvature of the outer surface of the drum body 20 and easily made to adhere closely to the outer surface of the drum body 20. In addition, by appropriately deforming the axial frame 42 made of an elastic material, various shapes of the axial frame 42, as illustrated in Figure 14, can be obtained.

[0050] The traveling drum 2 of this embodiment is manufactured by the method described above. Therefore, the traveling drum 2 comprises a cylindrical pseudo-road surface 3 and a drum body 20 that supports the pseudo-road surface 3, and multiple joints of composition 50 are formed on the pseudo-road surface 3 in the circumferential direction of the drum. The locations where the joints 50 are formed are set to have different circumferential pitches, and the maximum value of the circumferential pitch is less than twice the minimum value.

[0051] The lengths of the circumferential pitch at the joint 50 are classified into types, and these are ordered in ascending order as SL1, SL2, ... SL N In that case, SL k (However, k=1 to N-1) and SL k+1 It is preferable that the difference between the two is 0.2% or more of the circumference of the drum body 20. It is preferable that the circumferential pitches of the locations where the joints 50 are formed are all different from each other. When the lengths of the circumferential pitches of the locations where the joints 50 are formed are classified and arranged in ascending order, an arithmetic or geometric progression relationship may be established. The joints 50 may have inclined portions that extend diagonally with respect to the drum axis. The shapes of the joints 50 in the radial direction of the drum may each be different from each other.

[0052] In this embodiment, a method is employed in which the pseudo-road surface 3 is directly applied to the main drum 20 by installing a formwork 4 on the main drum 20 and filling and curing the composition as described above, but the method is not limited to this. For example, a method may be employed in which the formwork 4 is installed on a mounting member that is detachably configured on the drum body 20, the composition is filled and cured, and then the mounting member is attached to the main drum 20 to apply the pseudo-road surface 3. Figure 17 shows an example of a mounting member used in such a method.

[0053] The mounting member 60 shown in Figure 17 is formed from an arc-shaped plate material curved along the circumferential direction of the drum. The outer surface of the mounting member 60 is provided with a hardened composition 5 that will become part of the simulated road surface 3. This composition 5 is formed by filling and hardening the unhardened composition as described above after installing a mold 4 (not shown in Figure 17) on the mounting member 60. The mounting member 60 is provided with mounting holes 60h for attachment to the outer surface of the drum body 20. By arranging a plurality of mounting members 60 in a ring shape around the outer circumference of the drum body 20, a cylindrical simulated road surface 3 supported by the drum body 20 is provided.

[0054] [1] As described above, this embodiment is a method for manufacturing a traveling drum 2 comprising a cylindrical pseudo-road surface 3 and a drum body 20 supporting the pseudo-road surface 3, comprising the steps of: installing a mold 4 on the drum body 20 or an attachment member 60 detachably configured on the drum body 20, which includes a pair of circumferential frames 41 extending in the circumferential direction of the drum and arranged at a distance in the axial direction of the drum, and an axial frame 42 that divides the molding space S sandwiched between the pair of circumferential frames 41 in the circumferential direction of the drum; and filling the molding space divided by the axial frame 42 with a composition 5 constituting the pseudo-road surface 3 and hardening it, wherein the installation locations of the axial frame 42 are set with different circumferential pitches, and the maximum value of the circumferential pitch is less than twice the minimum value.

[0055] This disperses the frequency components caused by the joint 50, suppressing adverse effects on the test accuracy of tire performance such as noise and axial force. Moreover, by setting the maximum circumferential pitch to less than twice the minimum value, it is possible to avoid the frequency of twice the minimum circumferential pitch component matching the frequency of the maximum circumferential pitch, thereby achieving a sufficient improvement effect.

[0056] [2] In the manufacturing method of the travel drum described in [1] above, the length of the circumferential pitch of the installation locations of the axial frame 42 is classified into types, and these are listed in ascending order as PL1, PL2, ... PL N In that case, PL k (However, k=1 to N-1) and PL k+1 It is preferable that the difference between these two values ​​is 0.2% or more of the circumference of the drum body 20. This allows for an appropriate variation in the circumferential pitch of the installation locations of the axial frame 42, thereby ensuring a good dispersion effect of frequency components caused by the joints 50.

[0057] [3] In the manufacturing method of the traveling drum described in [1] or [2] above, it is preferable that the circumferential pitches of all the installation locations of the axial frame 42 are different from each other. This makes it possible to more effectively improve the dispersion effect of frequency components caused by the joints 50.

[0058] [4] In any one of the above methods for manufacturing the travel drum [1] to [3], the lengths of the circumferential pitch at the installation locations of the axial frame 42 may be classified into types, and when these are arranged in ascending order, an arithmetic or geometric progression may be established. This allows for a planned shift in frequency.

[0059] [5] In any one of the above [1] to [4] methods for manufacturing a running drum, the axial frame 42 may have an inclined portion 42s that extends diagonally with respect to the drum axis. By having such an inclined portion 42s, it is possible to prevent large inputs caused by the tire contact surface simultaneously colliding with or separating from the joint 50. Therefore, in combination with the dispersion effect of frequency components caused by the joint 50, tire performance can be tested with greater precision.

[0060] [6] In any one of the above [1] to [5] methods for manufacturing a traveling drum, the axial frames 42 installed adjacent to each other in the circumferential direction of the drum may have different shapes when viewed in the radial direction of the drum. This causes the circumferential pitch of the installation locations of the axial frames 42 to change in the axial direction of the drum, thereby enhancing the dispersion effect of frequency components caused by the joints 50.

[0061] [7] Furthermore, the traveling drum 2 of this disclosure comprises a cylindrical pseudo-road surface 3 and a drum body 20 that supports the pseudo-road surface 3. Multiple joints 50 of composition 5 are formed on the pseudo-road surface 3 in the circumferential direction of the drum, and the locations where the joints 50 are formed are set to have different circumferential pitches, with the maximum value of the circumferential pitch being less than twice the minimum value.

[0062] With this running drum 2, frequency components caused by the joints 50 can be dispersed, suppressing adverse effects on the test accuracy of tire performance such as noise and axial force. Moreover, by setting the maximum value of the circumferential pitch to less than twice the minimum value, it is possible to avoid the frequency of the component that is twice the minimum circumferential pitch matching the frequency of the maximum circumferential pitch, thereby achieving a sufficient improvement effect.

[0063] While embodiments of this disclosure have been described above, it should be understood that the specific configuration is not limited to these embodiments. The scope of this disclosure is defined not only by the above-described embodiments but also by the claims, and further includes all modifications within the meaning and scope of equivalence to the claims.

[0064] Therefore, for example, in the above-described embodiment, the traveling drum 2 is shown as an outer drum that drives by pressing the tire T against its outer circumferential surface, but it is not limited to this, and may be an inner drum that drives by pressing the tire against its inner circumferential surface. In that case, a mold can be installed on the inner circumferential surface of the cylindrical drum body, or a mold can be installed on a mounting member that is detachably configured on the inner circumferential surface of the drum body, and the simulated road surface can be formed in the same manner as in the above-described embodiment. In addition, in the first and second filling steps, it is preferable that the molding space into which the composition is filled is located downwards (around the 6 o'clock position when viewed from the drum axis direction).

[0065] The manufacturing method and the traveling drum described herein are not limited in any way to the embodiments described above, and various improvements and modifications are possible without departing from the spirit of the invention. Furthermore, the components used in the embodiments described above can be used in any combination. [Explanation of Symbols]

[0066] 1. On-board testing apparatus 2. Travel drum 3 Simulated road surface 4 Formwork 5 Composition 5e End face 20 Drum Body 41 Circumferential Frame 42 Axial frame 42s slope part 50 joints 60 Mounting components

Claims

1. A method for manufacturing a traveling drum comprising a cylindrical simulated road surface and a drum body supporting the simulated road surface, A step of installing a mold on the drum body or a mounting member detachably configured on the drum body, the mold includes a pair of circumferential frames extending in the circumferential direction of the drum and arranged at a distance from each other in the axial direction of the drum, and an axial frame that divides the molding space sandwiched between the pair of circumferential frames in the circumferential direction of the drum. The process includes filling the molding space partitioned by the axial frame with the composition constituting the simulated road surface and allowing it to harden, The installation locations of the aforementioned axial frame are set with different circumferential pitches, and the maximum value of the circumferential pitch is less than twice the minimum value. The lengths of the circumferential pitch at the installation locations of the axial frame are classified into types, and these are ordered from smallest to largest. １ , PL ２ ,...PL Ｎ In that case, PL ｋ (However, k = 1 to N-1) and PL ｋ＋１ A method for manufacturing a traveling drum, characterized in that the difference between the two is 0.2% or more of the circumference of the drum body.

2. A method for manufacturing a traveling drum comprising a cylindrical simulated road surface and a drum body supporting the simulated road surface, A step of installing a mold on the drum body or a mounting member detachably configured on the drum body, the mold includes a pair of circumferential frames extending in the circumferential direction of the drum and arranged at a distance from each other in the axial direction of the drum, and an axial frame that divides the molding space sandwiched between the pair of circumferential frames in the circumferential direction of the drum. The process includes filling the molding space partitioned by the axial frame with the composition constituting the simulated road surface and allowing it to harden, The installation locations of the aforementioned axial frame are set with different circumferential pitches, and the maximum value of the circumferential pitch is less than twice the minimum value. A method for manufacturing a traveling drum, characterized in that the lengths of the circumferential pitch at the installation locations of the axial frame are classified into types, and when these are arranged in ascending order, an arithmetic or geometric progression relationship is established.

3. A method for manufacturing a traveling drum comprising a cylindrical simulated road surface and a drum body supporting the simulated road surface, A step of installing a mold on the drum body or a mounting member detachably configured on the drum body, the mold includes a pair of circumferential frames extending in the circumferential direction of the drum and arranged at a distance from each other in the axial direction of the drum, and an axial frame that divides the molding space sandwiched between the pair of circumferential frames in the circumferential direction of the drum. The process includes filling the molding space partitioned by the axial frame with the composition constituting the simulated road surface and allowing it to harden, The installation locations of the aforementioned axial frame are set with different circumferential pitches, and the maximum value of the circumferential pitch is less than twice the minimum value. A method for manufacturing a traveling drum, characterized in that the axial frame has an inclined portion that extends diagonally with respect to the drum axis.

4. A method for manufacturing a traveling drum comprising a cylindrical simulated road surface and a drum body supporting the simulated road surface, A step of installing a mold on the drum body or a mounting member detachably configured on the drum body, the mold includes a pair of circumferential frames extending in the circumferential direction of the drum and arranged at a distance from each other in the axial direction of the drum, and an axial frame that divides the molding space sandwiched between the pair of circumferential frames in the circumferential direction of the drum. The process includes filling the molding space partitioned by the axial frame with the composition constituting the simulated road surface and allowing it to harden, The installation locations of the aforementioned axial frame are set with different circumferential pitches, and the maximum value of the circumferential pitch is less than twice the minimum value. A method for manufacturing a traveling drum, characterized in that the axial frames, which are installed adjacent to each other in the circumferential direction of the drum, have different shapes when viewed in the radial direction of the drum.

5. comprising a cylindrical simulated road surface and a drum body supporting the simulated road surface, The aforementioned simulated road surface has multiple joints formed in the composition at various locations in the circumferential direction of the drum. The locations where the aforementioned joints are formed are set to have different circumferential pitches, and the maximum value of the circumferential pitch is less than twice the minimum value. A traveling drum in which the lengths of the circumferential pitch of the joint formation locations are classified into types, and these are designated in ascending order as PL1, PL2, ... PLN, such that the difference between PLk (where k = 1 to N-1) and PLk+1 is 0.2% or more of the circumferential length of the drum body.

6. A cylindrical simulated road surface and a drum body supporting the simulated road surface, The aforementioned simulated road surface has multiple joints formed in the composition at various locations in the circumferential direction of the drum. The locations where the aforementioned joints are formed are set to have different circumferential pitches, and the maximum value of the circumferential pitch is less than twice the minimum value. A travel drum in which the lengths of the circumferential pitch of the joint formation locations are classified and arranged in ascending order such that an arithmetic or geometric progression is established.

7. It comprises a cylindrical simulated road surface and a drum body that supports the simulated road surface, The aforementioned simulated road surface has multiple joints formed in the composition at various locations in the circumferential direction of the drum. The locations where the aforementioned joints are formed are set to have different circumferential pitches, and the maximum value of the circumferential pitch is less than twice the minimum value. The aforementioned joint has an inclined portion that extends diagonally with respect to the drum axis, in a traveling drum.

8. A cylindrical simulated road surface and a drum body supporting the simulated road surface, The aforementioned simulated road surface has multiple joints formed in the composition at various locations in the circumferential direction of the drum. The locations where the aforementioned joints are formed are set to have different circumferential pitches, and the maximum value of the circumferential pitch is less than twice the minimum value. A traveling drum in which the joints formed adjacent to each other in the circumferential direction of the drum have different shapes when viewed in the radial direction of the drum.

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