Method for manufacturing a travel drum and travel drum
The method addresses seam-induced input forces on tires by using a mold with inclined joints, ensuring accurate tire performance evaluation in running drum tests.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- TOYO TIRE CORP
- Filing Date
- 2022-06-29
- Publication Date
- 2026-07-07
AI Technical Summary
Conventional methods for manufacturing running drums result in seams on the pseudo-road surface, leading to excessive input forces on tires during testing, affecting the accuracy of tire performance evaluation such as noise and axial force.
A method involving a mold with circumferential and axial frames that form inclined joints on the pseudo-road surface, preventing simultaneous collision or separation of the tire contact surface with the seams, using a composition of aggregate and binder cured to form a cylindrical pseudo-road surface.
The method ensures accurate tire performance testing by minimizing large input forces from seams, enhancing the precision of noise and axial force measurements.
Smart Images
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Abstract
Description
Technical Field
[0001] The present disclosure relates to a method for manufacturing a running drum used in tire performance tests and to a running drum.
Background Art
[0002] Conventionally, bench tests have been carried out indoors to evaluate tire performance such as noise and axial force. In such bench tests, generally, a bench test apparatus having a running drum including a cylindrical pseudo-road surface and a drum body supporting the pseudo-road surface is used.
[0003] Patent Document 1 describes 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 peripheral surface of a drum body and cured to form a pseudo-road surface. The molding space is divided in the circumferential direction of the drum with an appropriate length so that the filled composition does not flow down. Therefore, while shifting the position of the molding space in the circumferential direction of the drum, the filling and curing of the composition are repeated to form a cylindrical pseudo-road surface. Therefore, seams of the composition are formed at a plurality of locations in the circumferential direction of the pseudo-road surface.
[0004] For a tire running on a pseudo-road surface, forces may be input due to contact with and separation from the seams formed on the pseudo-road surface. If this input is excessively large, it may affect the evaluation of tire performance such as noise and axial force and may cause a decrease in test accuracy. Due to the manufacturing method of the running drum, it is difficult to form a pseudo-road surface without seams, and thus a technique for preventing a large input caused by seams from being applied to the tire is desired.
Prior Art Documents
Patent Documents
[0005]
Patent Document 1
Summary of the Invention
Problems to be Solved by the Invention
[0006] This disclosure has been 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 to be attached to 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 curing it, wherein the axial frame has an inclined portion that extends obliquely with respect to the axial direction of the drum.
[0008] The traveling 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 the composition formed in the circumferential direction of the drum, and the joints have inclined portions that extend obliquely with respect to the drum axis. [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 unfolded drawing of the drum body after the installation process, and (B) Plan view unfolded drawing of the drum body after the first filling process. [Figure 5] (A) Plan view of the drum body after the removal process, and (B) Plan view of the drum body after the second filling process. [Figure 6] Schematic diagram showing formwork [Figure 7] Schematic diagram showing a modified formwork. [Figure 8] Schematic diagram showing a modified formwork. [Figure 9] Schematic diagram showing a modified formwork. [Figure 10] A diagram illustrating the rough surface shape of the axial frame. [Figure 11] Perspective view showing an example of a mounting component. [Modes 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 pseudo road surface 3 is formed by curing a composition prepared by blending an aggregate and a binder. The aggregate, for example, has a maximum aggregate grain size of 8 mm (the allowable range is 6.3 mm to 10 mm), and the target particle size curve of the aggregate is within the range of the particle size curve of the ISO road surface standard. Accordingly, a material prepared by blending coarse aggregate, fine aggregate, and filler is used. As the binder, for example, a known synthetic resin is used, but from the viewpoint of ensuring the bonding strength between the aggregate and the bonding strength between the outer peripheral surface of the drum body 20, an epoxy resin is preferably used. Although not shown in FIG. 2, joints of the composition are formed at a plurality of locations in the drum circumferential direction on the pseudo road surface 3.
[0016] Next, a method for manufacturing the traveling drum will be described. The method for manufacturing the traveling drum 2 in this embodiment includes an installation step, a first filling step, a removal step, and a second filling step. By passing through the steps including these, the pseudo road surface 3 can be provided on the drum body 20, and thereby the traveling drum 2 shown in FIGS. 1 and 2 is manufactured.
[0017] As a method for manufacturing the traveling drum 2, first, the drum body 20 is prepared. The drum body 20 is held rotatably, for example, with the drum axis direction being horizontal. Next, as shown in FIG. 3, a mold 4 is installed on the drum body 20 (installation step). The mold 4 projects outward in the drum diameter direction from the outer peripheral surface of the drum body 20. The mold 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 in the drum axis direction. The axial frame 42 divides the molding space S sandwiched between the pair of circumferential frames 41 in the drum circumferential direction.
[0018] FIG. 4(A) is a developed plan view of the drum body 20, and the drum central axis 2C is shown by a chain line. The axial frame 42 extends along the drum axial direction 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 a plurality of molding spaces S1, S2, S3... by a plurality of axial frames 42 arranged at intervals in the drum circumferential direction. Although it is desirable to increase the drum circumferential length of each of the molding spaces S1, S2, S3... from the viewpoint of reducing the number of joints, if it is excessively large, the uncured composition will flow down. Therefore, the interval of the axial frames 42 is appropriately determined in consideration of their balance.
[0019] Subsequently, as shown in FIG. 4(B), an uncured composition 5 constituting the pseudo road surface 3 is filled into the molding space S1 divided by the axial frame 42 and cured (first filling step). The molding space S1 into which the composition 5 is filled is arranged upward (near the 12 o'clock direction when viewed from the drum axial direction) in advance so that the filled uncured composition 5 does not flow down. In the present embodiment, the circumferential frame 41 is formed in an annular shape along the drum circumferential direction. However, it is not limited thereto, and the circumferential frame 41 may be arranged in a range including the molding space (molding space S1 in FIG. 4(B)) into which the uncured composition 5 is filled.
[0020] As shown in FIG. 5(A), after the filled composition 5 is cured, the axial frame 42 in contact with the composition 5 is removed (removing step). As a result, the end face 5e of the composition 5 that was in contact with the side wall surface (the surface facing the drum circumferential direction) of the axial frame 42 is exposed. The shape of the exposed end face 5e in the drum radial direction view (for example, plan view) is the shape corresponding to the axial frame 42 that was in contact with the end face 5e. Such a removing step may be performed before the composition 5 is completely cured as long as the composition 5 is cured to such an extent that the shape of the end face 5e does not collapse significantly (it is not deformed by 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] Figure 6 is a schematic diagram showing the formwork 4. 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 Figures 7-9). Figure 6 shows the molding space S1, which is one of the molding spaces divided by the axial frame 42. The axial frame 42 has an inclined portion 42s that extends diagonally with respect to the drum axis direction. This forms an end face 5e with a shape corresponding to the inclined portion 42s (see Figure 5(A)), and consequently forms a joint 50 with a shape corresponding to the inclined portion 42s (see Figure 5(B)). As a result, the joint 50 of the pseudo-road surface 3 has an inclined portion that extends diagonally with respect to the drum axis direction.
[0024] In the case of the axial frame extending parallel to the drum axis direction, as in the prior art (Patent Document 1), a joint extending parallel to the drum axis direction is formed. A joint of this shape tends to coincide with the contour line of the tire contact surface. Therefore, when the tire is driven on a simulated road surface, there is a risk that a large input caused by the joint may be applied to the tire, either by the pressing side of the tire contact surface simultaneously colliding with the joint, or by the pushing side of the tire contact surface simultaneously separating from the joint. This can affect the evaluation of tire performance such as noise and axial force, and may cause a decrease in test accuracy.
[0025] In contrast, according to this embodiment, by forming a joint 50 having 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, with the joint 50 shown in Figure 5(B), the timing of the pressing side of the tire contact surface colliding with the joint will be different on 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, and allows for accurate testing of tire performance such as noise and axial force.
[0026] The acute angle θ of the axial frame 42 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 seams 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 seams 50 is reduced. The relationship between the length L of the molding space and the number of seams 50 will be explained later.
[0027] The axial frame 42 shown in Figure 6 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 7(A) to (C), the axial frame 42 does not need to 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).
[0028] In the example shown in Figure 6, the inclined portion 42s is formed in a straight line, and as a result, the axial frame 42 as a whole is also formed in a straight line. 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 7 to 9.
[0029] In Figure 7, 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 6) 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.
[0030] In Figure 7(A), one end of the axial frame 42 extends parallel to the drum axis, and in Figure 7(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 7(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 7(C) has the same shape as in Figure 7(B), except that it is formed in a zigzag line shape when viewed radially from the drum. The axial frame 42 shown in Figure 7 has one or more inflection points 42p.
[0031] In the example shown in Figure 8, the inclined portion 42s is formed in a curved shape when viewed in the radial direction of the drum. In Figure 8(A), the inclined portion 42s is formed in an arc shape without an inflection point. In Figure 8(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 8(C), one end of the axial frame 42, and in Figure 8(D), both ends of the axial frame 42, are formed in a straight line substantially parallel to the drum axis direction.
[0032] In the example shown in Figure 9, the inclined portion 42s is formed in a V-shape or U-shape when viewed in the radial direction of the drum. In Figure 9(A), the inclined portion 42s is formed in a V-shape by combining two straight lines. In Figure 9(B), the inclined portion 42s is formed in a V-shape by combining two curves (arcs). In Figure 9(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 be formed in a straight line substantially parallel to the drum axis direction.
[0033] The axial frame 42 preferably has a rough surface 42f (see Figure 10) facing the molding space S. With this configuration, the end face 5e of the composition 5 exposed by the removal process is formed as a rough surface by the rough surface 42f. As a result, when uncured composition 5 is filled into the molding space facing the end face 5e of composition 5, the compositions 5 fit together well and adhere well, and the widening of the seam and the occurrence of steps formed between them are suppressed. The rough surface 42f is preferably formed on at least the inclined portion 42s.
[0034] The form of the rough surface 42f is not particularly limited as long as it provides the effect of making the compositions blend together as described above, but for example, the form shown in Figure 10 can be cited. Figure 10(A) shows an example in which the rough surface 42f has been subjected to roughening treatment by blasting or polishing. Examples of blasting include shot blasting and sandblasting. Examples of polishing include polishing using abrasive cloth, abrasive paper (sandpaper), files, and electrolytic polishing. For example, polishing using abrasive cloth with a grit size of #50, #60, or #80 in accordance with JIS R 6010 is also acceptable. The surface roughness (finished surface roughness) of the rough surface 42f in accordance with JIS B 0601 is preferably an arithmetic mean roughness Ra of 0.8 to 3.2 μm, and the maximum height Rz is preferably 3.2 to 12.5 μm.
[0035] In Figures 10(B) to (D), the rough surface 42f is formed by an uneven surface containing numerous grooves. Figure 10(B) is an example in which grooves in multiple directions are used. In Figure 10(B), the uneven surface forming the rough surface 42f is composed of a grid of grooves: longitudinal grooves G1 corresponding to the drum diameter direction and transverse grooves G2 corresponding to the drum axis direction. As a variation, grooves G1 and G2 may each be angled. With an uneven surface containing such a grid of grooves, a relatively fine-grained rough surface 42f is formed, which is excellent in making it easier for the compositions to blend together.
[0036] Figures 10(C) and (D) show examples in which grooves are arranged in a single direction. In Figure 10(C), the uneven surface forming the rough surface 42f is composed of stripe-shaped grooves formed by longitudinal grooves G1. This reduces the resistance when moving the axial frame 42 along the drum diameter during the removal process of removing the axial frame 42. In Figure 10(D), the uneven surface forming the rough surface 42f is composed of stripe-shaped grooves formed by transverse grooves G2. This prevents the jagged shape of the rough surface 42f from appearing on the outer surface of the composition 5.
[0037] The grooves G1 and G2 described above can be provided, for example, by machining. The spacing of grooves G1 is, for example, 1 to 10 mm. The width of grooves G1 is, for example, 1 to 10 mm. The depth of grooves G1 is, for example, 1 to 10 mm. The cross-sectional shape of grooves G1 is not particularly limited, and various shapes such as semicircular, rectangular, or triangular shapes can be used. The same applies to the dimensions and cross-sectional shape of grooves G2. Grooves G1 and G2 reach the ends of the axial frame 42 in the drum axial direction and / or drum radial direction, but are not limited to this, and do not need to reach the ends.
[0038] Although not shown in the illustration, other possible examples of the rough surface 42f include forms employing dimples (indentations), protrusions, or combinations thereof. Another possible example of the rough surface 42f is a form employing a three-dimensional shape with amplitude in the drum axial direction and drum diameter direction. For example, a form employing a Miura-fold-like uneven surface formed by combining parallelogram surfaces is conceivable. In these examples, the amount of unevenness on the side wall surface (the distance between the most recessed and most protruding points in the thickness direction of the axial frame 42) is, for example, 1 to 10 mm.
[0039] In this embodiment, the entire side wall surface of the axial frame 42 is formed with a rough surface 42f, but this is not limited to this. For example, the rough surface 42f does not need to be formed in the region of the side wall surface of the axial frame 42 on the inner side in the drum radial direction. Also, the region of the side wall surface of the axial frame 42 on the outer side in the drum radial direction may be rougher than the inner region. This is because, in order to suppress the widening of the joint 50 and the occurrence of steps, it is sufficient to allow the compositions to blend well on the outer circumferential surface of the pseudo-road surface 3 that contacts the tire. Similarly, the rough surface 42f only needs to be formed in the central part in the drum axial direction, and does not need to be formed at the ends. This is because the tire T is assumed to be in contact with the central part of the pseudo-road surface 3 (see Figure 1).
[0040] The side wall surface of the axial frame 42 on which the roughened surface 42f is formed is preferably rougher than the bottom surface of the axial frame 42 (the surface in contact with the outer circumferential surface of the drum body 20). In other words, the bottom surface of the axial frame 42 is preferably smoother than the side wall surface of the axial frame 42. With this configuration, it is easier to bring the axial frame 42 into close contact with the outer circumferential surface of the drum body 20, which is convenient for dividing the molding space into which the uncured composition 5 is filled. The bottom surface of the axial frame 42 does not necessarily have to be roughened.
[0041] The side wall surface of the axial frame 42 on which the roughened surface 42f is formed is preferably rougher than the end face of the axial frame 42 (the surface in contact with the circumferential frame 41). In other words, the end face of the axial frame 42 is preferably smoother than the side wall surface of the axial frame 42. With this configuration, it is easier to bring the axial frame 42 into close contact with the circumferential frame 41, which is convenient for dividing the molding space into which the uncured composition 5 is filled. The end face of the axial frame 42 does not necessarily have to be roughened.
[0042] 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 can be easily made to adhere closely to the outer surface of the drum body 20.
[0043] 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 joints 50 have inclined portions that extend diagonally with respect to the drum axis. These inclined portions of the joints 50 are formed by the inclined portions 42s of the axial frame 42 as described above.
[0044] The acute angle of the joint 50 with respect to the drum axis direction is preferably 30 to 60 degrees. This angle corresponds to the acute angle θ of the axial frame 42 with respect to the drum axis direction (see Figure 6). The inclined portion of the joint 50 may be formed in a linear, curved, bent, zigzag, or a combination thereof in view in the radial direction of the drum. At least one end of the joint 50 is preferably substantially parallel to the drum axis direction.
[0045] 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 11 shows an example of a mounting member used in such a method.
[0046] The mounting member 60 shown in Figure 11 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 11) 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.
[0047] [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 a mounting member 60 detachably configured to be attached to the drum body 20, the mold 4 including 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 axial frame 42 has an inclined portion 42s that extends obliquely with respect to the axial direction of the drum.
[0048] Because the axial frame 42 has an inclined portion 42s, a joint 50 with a corresponding inclined portion is formed. Therefore, 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 all at once, or that the pushing side of the tire contact surface detaches from the joint all at once. As a result, a driving drum is manufactured that prevents large inputs caused by the joint 50 from being applied to the tires, and allows for accurate testing of tire performance such as noise and axial force.
[0049] [2] In the manufacturing method of the running drum described in [1] above, it is preferable that the acute angle θ of the axial frame 42 with respect to the drum axis is 30 to 60 degrees. When the angle θ exceeds 30 degrees, the effect of preventing large inputs caused by the tire contact surface simultaneously colliding with or separating from the joints 50 is more effectively achieved. Also, when the angle θ is less than 60 degrees, the length L of the molding space separated by the axial frame 42 does not become too large, which is convenient for reducing the number of joints 50.
[0050] [3] In the manufacturing method of the traveling drum described in [1] or [2] above, the inclined portion 42s may be formed in a linear, curved, bent, zigzag, or a combination thereof when viewed in the radial direction of the drum. Various such shapes can be adopted for the inclined portion 42s and the axial frame 42 having it.
[0051] [4] In any one of the above [1] to [3] methods for manufacturing a running drum, at least one end of the axial frame 42 may extend substantially parallel to the drum axis direction. This makes it possible to reduce the drum circumferential length L of the molding space (molding space S1, etc.) separated by the axial frame 42, compared to the case where the inclined portion 42s is extended to the end, which is advantageous in reducing the number of seams 50. As previously mentioned, from the viewpoint of suppressing a decrease in the accuracy of tire performance testing, it is desirable to have as few seams 50 as possible.
[0052] [5] Furthermore, the traveling drum 2 of this embodiment comprises a cylindrical simulated road surface 3 and a drum body 20 that supports the simulated road surface 3. Multiple joints 50 of composition 5 are formed on the simulated road surface 3 in the circumferential direction of the drum, and these joints 50 have inclined portions that extend diagonally with respect to the drum axis.
[0053] The presence of such an inclined section in the joint 50 prevents the entire tire contact surface from simultaneously colliding with the joint or the entire tire contact surface from simultaneously separating from the joint when the tires are driven on the simulated road surface 3. As a result, it prevents large inputs caused by the joint 50 from being applied to the tires, and enables the manufacture of a running drum that can accurately test tire performance such as noise and axial force.
[0054] 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.
[0055] 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).
[0056] 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]
[0057] 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 42f Rough surface 42s slope part 50 joints 60 Mounting components
Claims
1. In 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. A step of filling the molding space partitioned by the axial frame with the composition constituting the pseudo-road surface and hardening it, After the filled composition has hardened, the axial frame in contact with the composition is removed. The process includes filling the molding space opposite the end face of the composition that was in contact with the removed axial frame with the uncured composition constituting the pseudo-road surface, adhering it to the end face, and curing it, 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.
2. The method for manufacturing a traveling drum according to claim 1, wherein the angle of the axial frame on the acute side with respect to the drum axis direction is 30 to 60 degrees.
3. The method for manufacturing a traveling drum according to claim 1, wherein the inclined portion is formed in a linear, curved, bent, zigzag, or a combination thereof shape when viewed in the radial direction of the drum.
4. A method for manufacturing a traveling drum according to any one of claims 1 to 3, wherein at least one end of the axial frame extends substantially parallel to the drum axis direction.
5. 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 circumferential direction of the drum where the compositions are bonded together. A traveling drum in which the aforementioned joint has an inclined portion that extends diagonally with respect to the drum axis.