Method for manufacturing a traveling drum and mold

Abstract

To provide a method for manufacturing a running drum capable of accurately testing the tire performance, and a framework for molding a pseudo road surface used for the method.SOLUTION: A method of manufacturing a running drum includes: an installation step 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 has a rough surface facing the molding space; a first filling step of filling an uncured composition 5 constituting a pseudo road surface into a molding space S1 divided by the axial frame 42; a removing step of removing the axial frame 41 in contact with the composition 5 after the filled composition 5 is cured; and a second filling step of filling the uncured composition 5 constituting the pseudo road surface into a molding space S2 opposite to an end surface 5e of the composition 5 in contact with the rough surface of the removed axial frame 42.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present disclosure relates to a method for manufacturing a running drum used in tire performance tests and a mold for forming a pseudo road surface used in the method.

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 in 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, 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] If the compositions adjacent to each other in the circumferential direction of the drum do not blend well, the width (gap) of the seam may increase or a step may occur at the seam, which may cause the tire performance to not be accurately tested. In contrast, Patent Document 1 proposes a method for making the compositions adjacent to each other in the circumferential direction of the drum blend well. Specifically, before the filled composition cures, the axial frame that divides the molding space in the circumferential direction of the drum is removed, and the composition in contact with the axial frame is removed, and a method of filling the composition into the molding space adjacent to the remaining composition is proposed.

[0005] However, the method described in Patent Document 1 involves the unnecessary step of removing the composition that was in contact with the axial frame. Furthermore, removing the composition in this way reduces the circumferential length of the composition molded in each filling cycle, raising concerns that the number of seams will increase compared to the case where the composition is not removed. As mentioned above, seams can reduce the accuracy of tire performance testing, so it is desirable to have as few seams as possible. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2017-138158 [Overview of the project] [Problems that the invention aims to solve]

[0007] This disclosure has been made in view of the above circumstances, and its purpose is to provide a method for manufacturing a running drum that can accurately test tire performance, and a mold for shaping a simulated road surface used in this method. [Means for solving the problem]

[0008] 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 comprises: an installation step of installing a mold 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 in the axial direction of the drum, and an axial frame that divides a molding space sandwiched between the pair of circumferential frames in the circumferential direction of the drum and has a rough surface facing the molding space; a first filling step of filling the molding space divided by the axial frame with an unhardened composition constituting the pseudo-road surface; a removal step of removing the axial frame in contact with the composition after the filled composition has hardened; and a second filling step of filling the molding space opposite the end face of the composition that was in contact with the rough surface of the removed axial frame with an unhardened composition constituting the pseudo-road surface.

[0009] The mold of this disclosure is a mold for forming a pseudo-road surface, which is installed on the drum body of a traveling drum to provide a cylindrical pseudo-road surface, and includes a pair of circumferential frames that extend in the circumferential direction of the drum and are arranged at a distance apart 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 has a rough surface facing the molding space. [Brief explanation of the drawing]

[0010] [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] Diagram illustrating the removal direction of the axial frame. [Figure 7]A diagram illustrating the rough surface shape of the axial frame. [Figure 8] Schematic diagram showing a modified formwork. [Figure 9] Schematic diagram showing a modified formwork. [Figure 10] Schematic diagram showing a modified formwork. [Figure 11] Schematic diagram showing a modified formwork. [Modes for carrying out the invention]

[0011] 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.

[0012] 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.

[0013] 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.

[0014] 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.

[0015] 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).

[0016] In this embodiment, the pseudo road surface 3 is formed by curing a composition prepared by blending an aggregate and a binder. The aggregate has, for example, 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 mixture of 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 with the aggregate and the bonding strength with 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.

[0017] Next, a method for manufacturing the running drum will be described. The method for manufacturing the running drum 2 in this embodiment includes an installation step, a first filling step, a removal step, and a second filling step. By going through the steps including these, the pseudo road surface 3 can be provided on the drum body 20, whereby the running drum 2 shown in FIGS. 1 and 2 is manufactured.

[0018] As a method for manufacturing the running 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 has a rough surface 42f that divides the molding space S sandwiched by the pair of circumferential frames 41 in the drum circumferential direction and faces the molding space S.

[0019] 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.

[0020] 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 (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 encompasses the molding space (molding space S1 in Figure 4(B)) into which the uncured composition 5 is filled.

[0021] 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 exposed end face 5e is formed as a rough surface by the rough surface 42f of the axial frame 42. If the entire side wall surface of the axial frame 42 is formed of a rough surface 42f, the end face 5e will also be finished as a rough surface. This removal step may be performed before the composition 5 has completely hardened, provided that the composition 5 has hardened to the extent that an end face 5e with the properties of the rough surface 42f appropriately transferred to it is obtained.

[0022] In this embodiment, because the axial frame 42 has a rough surface 42f, there is a risk that the rough surface 42f formed on the side wall surface of the axial frame 42 may get caught on the composition 5 (especially the aggregate) when the axial frame 42 is removed during the removal process. However, if the axial frame 42 is moved away from the composition 5 along the circumferential direction of the drum, rather than simply being pulled out radially outward in the drum, as shown in Figure 6, the risk of the composition 5 getting caught is suppressed, and no problems arise due to the rough surface 42f.

[0023] 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 the end face 5e of composition 5 that was in contact with the rough surface 42f of the removed axial frame 42 (second filling step). 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 divided by the axial frame 42, and the other side is divided by the end face 5e of composition 5. For convenience of explanation, of the adjacent compositions 5 in the drum circumferential direction, the one that hardened first and exposed its end face 5e is called composition 5X, and the one that was filled afterward is called composition 5Y.

[0024] As described above, the end face 5e of composition 5X is formed as a rough surface. Therefore, composition 5Y filled into the molding space S2 adheres well with composition 5X at the end face 5e. As a result, composition 5X and composition 5Y adhere well, and the widening of the joint 50 formed between them and the occurrence of steps are suppressed. In addition, since it is not necessary to remove composition 5 as in the prior art (Patent Document 1), the work is simplified, and the circumferential length of the drum of composition 5 molded in one filling does not decrease, so there is no concern that the number of joints 50 will increase. Thus, it is possible to manufacture a running drum that can accurately test tire performance such as noise.

[0025] After the composition 5 filled into the molding space S2 has hardened, the axial frame 42 in contact with the composition 5 is removed. The end face of the composition 5 that is then exposed is formed as a rough surface by the rough surface 42f of the removed axial frame 42, and thus blends well with the unhardened composition 5 that is subsequently filled into the molding space S3. In this way, 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.

[0026] 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 7 can be cited. Figure 7(A) shows an example in which the rough surface 42f has been roughened 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 a maximum height Rz of 3.2 to 12.5 μm.

[0027] In Figures 7(B) to 7(D), the rough surface 42f is formed by an uneven surface containing numerous grooves. Figure 7(B) is an example in which grooves in multiple directions are used. In Figure 7(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 modification, grooves G1 and G2 may each be made at an angle. 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.

[0028] Figures 7(C) and 7(D) show examples where grooves are arranged in a single direction. In Figure 7(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 7(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.

[0029] 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.

[0030] 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.

[0031] 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).

[0032] 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.

[0033] 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.

[0034] 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.

[0035] In this embodiment, an example is shown in which 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. In that case, the joint 50 of the composition 5 formed on the pseudo-road surface 3 (see Figure 5(B)) will have an inclined portion that extends diagonally with respect to the drum axis direction. In an axial frame 42 having such an inclined portion 42s, it is preferable that the rough surface 42f is formed at least on the inclined portion 42s.

[0036] 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.

[0037] 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.

[0038] 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. Furthermore, it is preferable that a rough surface 42f is formed on the inclined portion 42s set in that region. 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).

[0039] 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 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. Modifications of the axial frame 42 will be described with reference to Figures 9 to 11.

[0040] 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.

[0041] 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.

[0042] 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.

[0043] 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.

[0044] [1] As described above, this embodiment is a method for manufacturing a traveling drum comprising a cylindrical pseudo-road surface 3 and a drum body 20 supporting the pseudo-road surface 3, comprising: an installation step of installing a mold 4 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 has a rough surface 42f facing the molding space; a first filling step of filling the molding space divided by the axial frame 42 with an unhardened composition 5 constituting the pseudo-road surface 3; a removal step of removing the axial frame 42 that is in contact with the composition 5 after the filled composition 5 has hardened; and a second filling step of filling the molding space opposite the end face 5e of the composition 5 that was in contact with the rough surface 42f of the removed axial frame 42 with the unhardened composition 5 constituting the pseudo-road surface 3.

[0045] According to this method, the end face 5e of composition 5 (composition 5X) that was in contact with the rough surface 42f of the axial frame 42 removed in the removal step is formed as a rough surface. This makes it easier to adhere composition 5 (composition 5Y) to be filled in the second filling step to the end face 5e of composition 5 (composition 5X). Furthermore, since it does not require the removal of the composition as in the conventional technology, the work is simplified, and there is no concern that the drum circumferential length of composition 5 formed in each filling step will decrease, thus increasing the number of joints 50. As a result, a running drum that can accurately test tire performance can be manufactured.

[0046] [2] In the method for manufacturing the travel drum described in [1] above, the rough surface 42f may be subjected to a roughening treatment by blasting or polishing. In this case, the rough surface 42f of the axial frame 42, which has been subjected to the roughening treatment, forms a rough surface on the end face 5e of the composition 5.

[0047] [3] In the method for manufacturing the travel drum described in [1] above, the rough surface 42f may be formed by an uneven surface containing a large number of grooves. In this case, the end face 5e of the composition 5 is formed as a rough surface by the rough surface 42f of the axial frame 42 which is formed by an uneven surface containing a large number of grooves.

[0048] [4] In any one of the above [1] to [3] methods for manufacturing a running drum, the axial frame 42f may have an inclined portion 42s that extends diagonally with respect to the drum axis, and the rough surface 42f may be formed at least on the inclined portion 42s. This forms a joint 50 having an inclined portion corresponding to the inclined portion 42s, thereby preventing large inputs caused by the tire contact surface simultaneously colliding with or separating from the joint 50. Furthermore, because the rough surface 24f is formed on the inclined portion 24s, it is easier to allow the composition 5Y to conform to the end face 5e of the composition 5X formed on the inclined portion 24s.

[0049] [5] Furthermore, the mold 4 of this embodiment is a mold 4 for forming a pseudo-road surface, which is installed on the drum body 20 of the traveling drum 2 to provide a cylindrical pseudo-road surface 3, and includes a pair of circumferential frames 41 that extend in the circumferential direction of the drum and are spaced apart 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 has a rough surface 42f facing the molding space. By manufacturing the traveling drum 2 using such a mold 4, the compositions 5 become easier to blend together as described above, so that a traveling drum that can accurately test tire performance can be manufactured.

[0050] 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.

[0051] Therefore, for example, in the above-described embodiment, the traveling drum 2 is shown as an outer drum that presses the tire T against its outer surface for driving, but it is not limited to this, and may be an inner drum that presses the tire against its inner surface for driving. In that case, a mold can be set on the inner surface of the cylindrical drum body, and a simulated road surface can be formed on the drum body 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).

[0052] The method for manufacturing a running drum and the mold for forming a simulated road surface used in the present disclosure 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 adopted in the embodiments described above can be used in any combination. [Explanation of symbols]

[0053] 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 section 50 joints

Claims

1. A method for manufacturing a traveling drum comprising a cylindrical simulated road surface and a drum body supporting the simulated road surface, Installation step of installing a mold on the drum body, which 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 and has a rough surface facing the molding space, A first filling step involves filling the molding space partitioned by the axial frame with the uncured composition constituting the simulated road surface, After the filled composition has hardened, a removal step is taken to remove the axial frame in contact with the composition, A method for manufacturing a running drum, comprising: a second filling step of filling the molding space opposite to the end face of the composition that was in contact with the rough surface of the removed axial frame with the uncured composition constituting the pseudo-road surface and adhering it to the end face.

2. The method for manufacturing a travel drum according to claim 1, wherein the rough surface is subjected to a surface roughening treatment by blasting or polishing.

3. The method for manufacturing a traveling drum according to claim 1, wherein the rough surface is formed by an uneven surface containing a large number of grooves.

4. The method for manufacturing a traveling drum according to any one of claims 1 to 3, wherein the axial frame has an inclined portion that extends diagonally with respect to the drum axis direction, and the rough surface is formed at least on the inclined portion.

5. A mold for forming a simulated road surface, which is installed on the drum body of a traveling drum to provide a cylindrical simulated road surface, comprising: a pair of circumferential frames extending in the circumferential direction of the drum and arranged at a distance apart in the axial direction of the drum; and an axial frame that divides the forming space sandwiched between the pair of circumferential frames in the circumferential direction of the drum and has a rough surface facing the forming space.

Images