Apparatus for manufacturing rubber components and method for manufacturing rubber components

Abstract

This promotes shrinkage of the rubber material during cooling and suppresses deterioration of dimensional uniformity of the rubber material after cutting. [Solution] The rubber member manufacturing apparatus comprises an extrusion molding section for extruding and molding rubber members, a conveying section 22 for conveying rubber members, and a cooling section for cooling the rubber members conveyed by the conveying section 22. The conveying section 22 has a drive transmission section 24 that is driven in a caterpillar-like manner and is provided to face each other inside the cooling section, a plurality of conveying shafts 25 that are fixed at both ends to the drive transmission section 24 and are arranged at intervals along the conveying direction inside the cooling section, and a plurality of rollers 26 that are rotatably provided with respect to the conveying shafts 25 and support the rubber members.

Description

Technical Field

[0001] The present invention relates to a rubber member manufacturing apparatus and a rubber member manufacturing method, and particularly to the cooling of rubber members.

Background Art

[0002] Conventionally, in a manufacturing apparatus for rubber members such as tires, the rubber member at a high temperature immediately after extrusion molding is cooled by being conveyed so as to pass through a cooling water tank. Thereby, the rubber member is cooled and shrunk. After that, the shrunk rubber member is cut into predetermined dimensions.

[0003] Prior art document 1 discloses a rubber member manufacturing method and a rubber member manufacturing apparatus that have a conveyor belt with a concave central portion and supply cooling water to the concave portion to efficiently cool the rubber member in a short time.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In the cooling of rubber members, there is a problem that the shrinkage of the rubber member is suppressed because the rubber member temporarily adheres to the surface of the conveyor belt that conveys the rubber member. In the cooling of rubber members, when the rubber member does not shrink sufficiently, shrinkage occurs after the rubber member is cut after cooling. In that case, variations occur in the shrinkage amount of the rubber member after cutting, and the dimensional uniformity of the rubber member deteriorates. Note that the problems cannot be solved even by the rubber member manufacturing method and the rubber member manufacturing apparatus described in prior art document 1.

Means for Solving the Problems

[0006] The rubber member manufacturing apparatus according to the present invention comprises an extrusion molding section for extruding a rubber member, a conveying section for conveying the rubber member, and a cooling section for cooling the rubber member conveyed by the conveying section, wherein the conveying section is provided inside the cooling section facing each other and driven in a caterpillar-like manner, a plurality of conveying shafts fixed at both ends to the drive transmission section and arranged at intervals along the conveying direction inside the cooling section, and a plurality of rollers rotatably provided with respect to the conveying shafts and supporting the rubber member. [Effects of the Invention]

[0007] According to the rubber member manufacturing apparatus and rubber member manufacturing method of the present invention, it is possible to promote shrinkage of the rubber member during cooling and suppress deterioration of dimensional uniformity of the rubber member after cutting. [Brief explanation of the drawing]

[0008] [Figure 1] This is an overall view showing the rubber component manufacturing apparatus according to this embodiment. [Figure 2] This is a top view showing the internal transport section according to this embodiment. [Figure 3] This diagram illustrates the drive mechanism of the internal transport unit according to this embodiment. [Figure 4] This is a flowchart showing the rubber component manufacturing method according to this embodiment. [Modes for carrying out the invention]

[0009] Hereinafter, an example of an embodiment of the rubber member manufacturing apparatus according to the present invention will be described in detail with reference to the drawings. The embodiment described below is merely an example, and the present invention is not limited to the embodiments described below. Furthermore, forms obtained by selectively combining each component of the embodiments described below are included in the present invention.

[0010] The overall structure of the rubber component manufacturing apparatus 1 will be explained with reference to Figure 1. Figure 1 is a schematic diagram of the rubber component manufacturing apparatus 1 according to this embodiment. For the purposes of this explanation, the direction along the conveying direction will be referred to as the front-rear direction. In the conveying direction, the side with the extrusion molding section 10 will be the upstream side, and the side opposite the extrusion molding section 10 will be the downstream side. In the front-rear direction, the upstream side in the conveying direction will be referred to as "front," and the downstream side in the conveying direction will be referred to as "rear." In Figure 1, the direction perpendicular to the conveying direction (front-rear direction) will be referred to as the up-down direction, and the upward and downward directions are defined as shown in Figure 1.

[0011] The rubber member manufacturing apparatus 1 according to this embodiment includes an extrusion molding section 10 for extruding and molding a rubber member G, a conveying section 20 for conveying the rubber member G, and a cooling section 30 for cooling the rubber member G conveyed by the conveying section 20. As will be described in more detail later, the conveying section 20 has a drive transmission section 24 that is provided to face each other inside the cooling section 30 and is driven in a caterpillar-like manner. Furthermore, the conveying section 20 has a plurality of conveying shafts 25 that are fixed at both ends to the drive transmission section 24 and are arranged at intervals along the conveying direction inside the cooling section 30, and a plurality of rollers 26 that are rotatably provided with respect to the conveying shafts 25 and support the rubber member G.

[0012] The extrusion molding unit 10 includes a hopper (not shown) into which rubber material is fed, a screw (not shown) that extrudes the rubber material while applying heat, and a die 11 having an opening from which the rubber member G is extruded. The amount of rubber member G extruded by the extrusion molding unit 10 is controlled by the rotation speed of the screw. The opening shape of the die 11 is formed, for example, as a trapezoid or a rectangle. The rubber member G is extruded, for example, in a long, elongated shape (strip) in the conveying direction. Examples of rubber member G include tread rubber, sidewall rubber, and bead filler rubber used in tire molding.

[0013] As described above, the rubber member manufacturing apparatus 1 has a cooling unit 30 that cools the rubber member G conveyed by the conveying unit 20. In this embodiment, the cooling unit 30 is a water-cooled cooling device. As shown in Figure 1, the cooling unit 30 in this embodiment has a cooling water tank 31 in which cooling water is stored and an injection unit 32 that sprays cooling water from above the rubber member G. The rubber member G, which is hot after extrusion molding, is cooled as it passes through the inside of the cooling unit 30, including the cooling water tank 31 and the injection unit 32.

[0014] The cooling water tank 31 is, for example, a rectangular box that is long in the direction of transport. Cooling water is stored in the cooling water tank 31 to cool the high-temperature rubber member G. The cooling water may be supplied by a pump (not shown) connected to the cooling water tank 31. Alternatively, the cooling water may be supplied by an injection unit 32, which will be described later.

[0015] The spray unit 32 is located above the cooling water tank 31 and sprays cooling water toward the rubber member G passing through the cooling water tank 31. Preferably, multiple spray units 32 are provided along the conveying direction. The spray units 32 are arranged in one or more rows in the conveying direction. The number and arrangement of the spray units 32 are appropriately determined depending on the type of rubber member G being manufactured. Note that the cooling unit 30 may not include a cooling water tank 31. In this case, the rubber member G is cooled by the spray of cooling water by the spray units 32.

[0016] As described above, the rubber member manufacturing apparatus 1 has a conveying unit 20 that conveys the rubber member G extruded from the extrusion molding unit 10. As shown in Figure 1, the rubber member manufacturing apparatus 1 has a plurality of conveying units 20.

[0017] Multiple transport units 20 are arranged in a line along the transport direction, for example, as shown in Figure 1. They receive the rubber member G extruded from the extrusion molding unit 10 and begin transporting it, transporting the rubber member G so that it passes through the inside of the cooling unit 30. Of the multiple transport units 20, the transport unit 20 located upstream of the cooling unit 30 is designated as the upstream transport unit 21, the transport unit 20 located inside the cooling unit 30 is designated as the internal transport unit 22, and the transport unit 20 located downstream of the cooling unit 30 is designated as the downstream transport unit 23. Specifically, the transport unit 20 that transports the rubber member G into the inside of the cooling unit 30 is designated as the upstream transport unit 21, and the transport unit 20 that removes the rubber member G from inside the cooling unit 30 is designated as the downstream transport unit 23.

[0018] The upstream conveying section 21 is provided at an angle downward toward the downstream side in the conveying direction. In this embodiment, the downstream side of the upstream conveying section 21 is housed in the cooling water tank 31. That is, the downstream side of the upstream conveying section 21 is immersed in the cooling water in the cooling water tank 31. This allows the rubber member G to enter the cooling water in the cooling water tank 31. The upstream conveying section 21 is, for example, a belt conveyor.

[0019] The internal transfer unit 22 transfers the rubber member G by supporting the rubber member G on its upper surface. The internal transfer unit 22 is provided in plurality in the cooling water tank 31 of the cooling unit 30, for example, as shown in FIG. 2. Specifically, the internal transfer unit 22 is submerged so that its entirety is immersed in the cooling water tank 31. Further, the internal transfer unit 22 is preferably provided at a position where the upper surface of the rubber member G does not get immersed in the cooling water in the cooling water tank 31. In other words, the distance between the water surface of the cooling water tank 31 and the upper surface of the internal transfer unit 22 in the cooling water tank 31 is preferably shorter than the vertical dimension (thickness) of the rubber member G. Thereby, by spraying cooling water onto the upper surface of the rubber member G using the spraying unit 32, a part of the cooling water that comes into contact with the upper surface of the rubber member G vaporizes, and the rubber member G is cooled by the heat of vaporization. As a result, the cooling effect of the rubber member G can be enhanced compared to the case where the rubber member G is completely immersed in the cooling water tank 31. Also, the reason for not submerging the entire rubber member G is to prevent the rubber member G from floating in the cooling water tank 31 because the specific gravity of rubber is lighter than water, and as a result, meandering occurs, leading to problems in receiving the rubber member G.

[0020] The downstream transfer unit 23 is provided inclined upward toward the downstream side in the transfer direction. In the present embodiment, the upstream side portion of the downstream transfer unit 23 is housed in the cooling water tank 31. That is, the upstream side portion of the downstream transfer unit 23 is immersed in the cooling water tank 31. Thereby, the rubber member G is taken out from the cooling water tank 31. The downstream transfer unit 23 is, for example, a belt conveyor.

[0021] Referring further to FIGS. 2 and 3, the structure of the internal transfer unit 22 according to the present embodiment will be described in detail. FIG. 2 is a top view of the internal transfer unit 22. FIG. 3 is a diagram for explaining the drive of the internal transfer unit 22. In FIG. 2, only the upper surface of the internal transfer unit 22 is shown for clarity of the drawing. In FIG. 2, the direction orthogonal to the front - rear direction is defined as the left - right direction, and left and right are defined as shown in FIG. 2. Note that FIG. 3 is a view of the internal transfer unit 22 in FIG. 2 as seen from the right side.

[0022] As shown in FIG. 2, the internal transfer unit 22 is provided inside the cooling unit 30 so as to face each other, and includes a drive transmission unit 24 driven in a caterpillar shape, and a plurality of transfer shafts 25 whose both ends are fixed to the drive transmission unit 24 and arranged along the transfer direction inside the cooling unit 30, and a plurality of rollers 26 rotatably provided with respect to the transfer shafts 25 and supporting the rubber member G.

[0023] As described above, the drive transmission unit 24 is arranged inside the cooling unit 30 so as to face each other. Specifically, as shown in FIG. 2, it is arranged so as to face each other in the left - right direction. Here, the inside of the cooling unit 30 is a region where the rubber member G is substantially cooled. In the present embodiment, since the cooling unit 30 is a water - cooled cooling device, it is a region where the rubber member G is cooled by the water - cooled cooling device. Specifically, it is a region inside the cooling water tank 31 and in the region where cooling water is sprayed by the injection unit 32. Hereinafter, the case where the drive transmission unit 24 is provided inside the cooling water tank 31 will be taken as an example for explanation. In addition, when the cooling unit 30 does not have the cooling water tank 31, the inside of the cooling unit 30 is a region where cooling water is sprayed by the injection unit 32.

[0024] As described above, the drive transmission unit 24 is driven in a caterpillar shape. Specifically, as shown in FIG. 3, it is rotationally driven in an oval shape having a straight portion. More specifically, as shown in FIG. 3, on the upper surface side of the drive transmission unit 24, it is driven from the downstream direction to the downstream direction, and on the lower surface side, it is driven from the upstream direction to the downstream direction. Also, at the upstream end of the drive transmission unit 24, it is driven so as to transition from the upper surface side to the lower surface side, and at the downstream end, it is driven so as to transition from the lower surface side to the upper surface side.

[0025] The drive transmission unit 24 is driven in a caterpillar-like manner by a drive unit 27 provided at least one end on the upstream and downstream sides in the conveying direction. Preferably, the drive transmission unit 24 has a connection structure for connecting to the drive unit 27 and receiving driving force. The connection structure is, for example, a plurality of bumps, teeth, or holes formed around the entire circumference of the inner diameter side of the drive transmission unit 24. Through this connection structure, the drive transmission unit 24 meshes with the drive unit 27, thereby receiving driving force from the drive unit 27. The drive transmission unit 24 is, for example, a timing belt or a roller chain.

[0026] The drive unit 27, for example as shown in Figure 2, has a motor 27a and a drive assist unit 27b connected to the motor 27a and around which the drive transmission unit 24 is wrapped. The motor 27a drives the drive transmission unit 24 via the drive assist unit 27b. The drive assist unit 27b is, for example, a sprocket or a toothed pulley, and drives the drive transmission unit 24 by rotating while meshing with a plurality of grooves and protrusions provided on the drive transmission unit 24. Although not shown in Figure 2 for clarity, the drive assist units 27b facing each other in the left-right direction are connected to each other by an shaft or the like. That is, the drive assist units 27b facing each other in the left-right direction rotate in a similar manner to each other.

[0027] In the examples shown in Figures 2 and 3, the drive unit 27 is provided on the front (upstream) side of the drive transmission unit 24. The drive unit 27 only needs to be provided on one side, either the upstream or downstream side in the conveying direction. In that case, a guide unit 28 that rotates freely and is driven by the drive transmission unit 24 is provided at the other end. In the examples shown in Figures 2 and 3, the guide unit 28 is provided on the rear side of the drive transmission unit 24. The guide unit 28 does not rotate on its own, but engages with the drive transmission unit 24 and is rotated by the drive transmission unit 24. Also, as shown in Figure 3, the guide unit 28 guides the drive transmission unit 24 from the bottom side to the top side. The guide unit 28 is a sprocket or toothed pulley, etc., similar to the drive assist unit 27b, and rotates while engaging with a connecting structure provided on the drive transmission unit 24. Also, guide units 28 facing each other in the left-right direction are connected to each other by a shaft, etc., similar to the drive assist unit 27b, and rotate similarly to each other.

[0028] The drive transmission unit 24 is preferably configured to fix the conveying shaft 25. The drive transmission unit 24 may have, for example, a plurality of bearings provided at intervals along the conveying direction. The conveying shaft 25 may be fixed to the drive transmission unit 24 by having both shafts supported by the bearings.

[0029] As described above, the conveying shafts 25 are fixed to the drive transmission unit 24. More specifically, as shown in Figure 2, multiple conveying shafts 25 are provided and arranged at intervals along the conveying direction. The conveying shafts 25 are fixed, for example, by having both ends supported by multiple bearings provided on the drive transmission unit 24. Here, it is preferable that the conveying shafts 25 are arranged at equal intervals. This allows the weight of the rubber member G to be evenly distributed, and the stability of conveying can be maintained. In addition, because the conveying shafts 25 are provided at intervals, the cooling water in the cooling water tank 31 permeates through the gaps between the conveying shafts 25 and comes into contact with the lower surface of the rubber member G, thus improving the cooling efficiency of the rubber member G compared to a belt conveyor with no gaps.

[0030] As described above, multiple rollers 26 are provided rotatably on the conveying shaft 25. Preferably, multiple rollers 26 are provided on the conveying shaft 25 at equal intervals, as shown in Figure 2. The number of rollers 26 per conveying shaft 25 is not particularly limited, but from the viewpoint of stability when supporting the rubber member G, it is preferable, for example, to be 2 to 10. Furthermore, it is more preferable that the number of rollers 26 per conveying shaft 25 be 4 to 8. This allows for more reliable support of the rubber member G, thereby improving the stability of conveying the rubber member G. Note that the number of rollers 26 per conveying shaft 25 may be appropriately set based on the dimensions of the rubber member G, etc. That is, the number of rollers 26 per conveying shaft 25 should be a number that can support the rubber member G.

[0031] The shape and dimensions of the roller 26 are not particularly limited, but it is preferable that it has a ring shape with a hole formed in the center of the disc shape for passing the conveying shaft 25 through. The following explanation will use the case where the roller 26 has a ring shape as an example. The outer diameter of the roller 26 is appropriately set based on the distance between adjacent conveying shafts 25 in the front-rear direction. The width of the roller 26 is appropriately set based on the length of the conveying shaft 25 in the left-right direction and the number of rollers 26 provided on the conveying shaft 25. For example, if the number of rollers 26 provided on the conveying shaft 25 is small, the width of the roller 26 is increased.

[0032] In the internal transport section 22, as described above, multiple rollers 26 directly support the rubber member G. Therefore, compared to a belt conveyor, the contact area with the rubber member G during transport is smaller. As a result, the area on which the rubber member G adheres is reduced, and the inhibition of the rubber member G's contraction due to adhesion is suppressed.

[0033] The roller 26 may be provided with a gap between it and the conveying shaft 25. That is, the inner diameter of the roller 26 may be formed to be larger than the shaft diameter of the conveying shaft 25. This allows the roller 26 to rotate freely relative to the conveying shaft 25. In particular, it is preferable that the inner diameter of the roller 26 is more than 100% but 150% or less of the shaft diameter of the conveying shaft 25. It is even more preferable that it is between 105% and 130%. The gap between the inner diameter of the roller 26 and the shaft diameter of the conveying shaft 25 is preferably 0.5 mm or more and 2.0 mm or less, for example, 0.6 mm.

[0034] When the roller 26 is installed with a gap between it and the conveying shaft 25, the roller 26 can move freely in the left-right direction on the conveying shaft 25. Therefore, a collar may be provided on the conveying shaft 25 to suppress the left-right movement of the roller 26. Preferably, the radial dimension of the collar on the conveying shaft 25 is smaller than the outer diameter of the roller 26. The collar is fixed to the conveying shaft 25, for example, between the rollers 26. Preferably, the collar is provided between adjacent rollers 26 in the left-right direction. This allows the roller 26 to move to some extent in the left-right direction, promoting the left-right contraction of the rubber member G, and the collar prevents the roller 26 from being biased to one side in the left-right direction. The collar may also be provided at both ends of the conveying shaft 25 in the left-right direction. In this case, the shaft diameter at both ends of the conveying shaft 25 may be made larger than the inner diameter of the roller 26 to be used as a collar.

[0035] The roller 26 is preferably made of synthetic resin. For example, the roller 26 is made of a synthetic resin such as monomer cast nylon. Because the roller 26 is made of synthetic resin, even when the roller 26 is positioned with a gap between it and the conveying shaft 25 as described above, the roller 26 slides more easily on the conveying shaft 25, allowing it to rotate more smoothly. In addition, since the roller 26 provided on the conveying shaft 25 is located inside the cooling water tank 31, using synthetic resin prevents deterioration of the roller 26, such as rust, compared to metal rollers.

[0036] As shown in Figure 2, it is preferable that the rollers 26 be arranged in a staggered pattern when the internal conveying section 22 is viewed from above. A staggered pattern means that the rollers 26 provided on adjacent conveying shafts 25 in the front-to-back direction are not aligned in the left-to-right direction, but are instead arranged alternately with a slight offset. This ensures that the rollers 26 are evenly distributed within the internal conveying section 22, thereby evenly distributing the load received from the rubber member G. As a result, the stability when supporting the rubber member G is improved, and the stability during the transport of the rubber member G is enhanced.

[0037] The transport unit 20 described above transports the rubber member G to a cutting unit (not shown) where, after the rubber member G has passed through the cooling unit 30 and been cooled, the rubber member G is dried and then cut into predetermined dimensions. At this time, according to the transport unit 20 (internal transport unit 22) of this embodiment, the rubber member G is sufficiently cooled and shrunk within the cooling unit 30, so dimensional changes due to shrinkage after being cut in the cutting unit are less likely to occur.

[0038] The rubber member manufacturing method according to this embodiment will be described below with reference to Figure 4. Figure 4 is a flowchart of the rubber member manufacturing method according to this embodiment.

[0039] In the extrusion molding process, a rubber member G is extruded and molded as shown in Figure 1 (step S1). Specifically, in the extrusion molding process S1, a long rubber member G is molded by extruding the rubber material while applying heat. The rubber member manufacturing method then includes a transport process (step S2) for transporting the rubber member G molded in the extrusion molding process S1. Furthermore, it includes a cooling process (step S3) for cooling the rubber member G transported in the transport process S2. Here, the transport process S2 starts after the completion of the extrusion molding process S1 and is performed during the cooling process S3 and after the completion of the cooling process S3. That is, the cooling process S3 is performed in the middle of the transport process S2.

[0040] In the cooling process S3, the contraction of the rubber member G is absorbed by the rotation of multiple rollers that are rotatably mounted on multiple transport shafts arranged at intervals along the transport direction. This improves the cooling efficiency during the cooling process S3 and allows the rubber member G to contract sufficiently. The cooling process S3 is performed by cooling the rubber member G using, for example, a rubber member manufacturing apparatus 1 having a cooling water tank 31 and an internal transport section 22 as shown in Figures 1 and 2.

[0041] In the cooling process S3, the rubber member G may be transported by the transport process S2 as described above and cooled by passing through the cooling water tank. That is, the rubber member G is transported so that it passes through the cooling water tank 31 during the transport process S2. Preferably, the transport process S2 transports the rubber member G so that it passes through the cooling water tank 31 in 100 seconds or more and 200 seconds or less. This allows the rubber member G to be sufficiently cooled and shrunk, and enables a quick transition to the process after the cooling process S3, thereby improving productivity.

[0042] As described above, the rubber member manufacturing apparatus and rubber member manufacturing method having the above configuration can promote shrinkage of the rubber member during cooling and suppress deterioration of dimensional uniformity of the rubber member after cutting. [Explanation of symbols]

[0043] 1 Rubber component manufacturing apparatus, 10 Extrusion molding section, 11 Die, 20 Conveying section, 21 Upstream conveying section, 22 Internal conveying section, 23 Downstream conveying section, 24 Drive transmission section, 25 Conveying shaft, 26 Roller, 27 Drive section, 27a Motor, 27b Drive assist section, 28 Guiding section, 30 Cooling section, 31 Cooling water tank, 32 Injection section, G Rubber component

Claims

1. An extrusion molding section for extruding and molding rubber components, A conveying unit for conveying the aforementioned rubber member, A cooling unit for cooling the rubber member being transported by the transport unit, A rubber component manufacturing apparatus equipped with, The aforementioned transport unit is The drive transmission units are arranged inside the cooling section so as to face each other and are driven in a caterpillar-like manner, Multiple transport shafts, each fixed at both ends to the drive transmission unit and arranged at intervals along the transport direction inside the cooling unit, Multiple rollers are provided to be rotatably mounted on the transport shaft and to support the rubber member, A rubber component manufacturing apparatus having the following features.

2. The rubber member manufacturing apparatus according to claim 1, wherein the plurality of rollers are arranged in a staggered pattern.

3. The rubber member manufacturing apparatus according to claim 1 or 2, wherein the plurality of rollers are made of synthetic resin.

4. An extrusion molding process for extruding rubber components, A transport process for transporting the aforementioned rubber member, A cooling step for cooling the rubber member being transported in the transport step, Includes, A method for manufacturing a rubber member, wherein in the cooling step, the contraction of the rubber member is absorbed by the rotation of a plurality of rollers that are rotatably mounted on a plurality of transport shafts arranged at intervals along the transport direction.

5. The cooling step involves the rubber member being cooled by passing through a cooling water tank during the transport step. The method for manufacturing a rubber member according to claim 4, wherein the conveying step is to convey the rubber member so that it passes through the cooling water tank in 100 seconds or more and 200 seconds or less.

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