Rubber Strip Manufacturing Equipment

Abstract

To provide a rubber strip manufacturing apparatus that can suppress an occurrence of bearing damage over a long period of time and reduce a frequency of bearing replacement.SOLUTION: A rubber strip manufacturing apparatus is equipped with a rubber extruder and a calender head with a pair of calender rolls. A rubber composition extruded from the rubber extruder is rolled into a predetermined shape by the pair of calender rolls to produce tape-shaped rubber strips. A rotating shaft of the calender roll supported by a shaft bearing of a bearing is inserted into an insertion hole in a side of the calender head. A collar with an outer diameter larger than the diameter of the insertion hole is fitted around a side edge of the calender roll to cover a gap between the rotating shaft of the calender roll and the insertion hole.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to an apparatus for producing a rubber strip. [Background technology]

[0002] As a method for manufacturing raw tires, a strip winding method (STW method) is known in which a tape-shaped rubber strip is spirally wound around a forming drum to be molded into a raw tire of a predetermined shape. In this strip winding method, the tape-shaped rubber strip is manufactured using a rubber strip manufacturing device.

[0003] The rubber strip manufacturing apparatus includes a rubber extruder and a calender head consisting of a pair of calender rolls. An unvulcanized rubber composition extruded from the extrusion port of the rubber extruder is rolled between the rolls of the calender head provided ahead of the extrusion port, thereby forming the composition into a rubber strip having a predetermined shape (profile) (for example, Patent Documents 1 to 4). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2006-82277 A [Patent Document 2] JP 2015-116704 A [Patent Document 3] JP 2016-196100 A [Patent Document 4] JP 2018-62109 A Summary of the Invention [Problem to be solved by the invention]

[0005] In the calender head of the rubber strip manufacturing apparatus described above, bearings are used as bearings for the rotating shafts of the calender rolls. Conventionally, the bearings have been periodically replaced to maintain the equipment so as to prevent breakdowns due to damage to the bearings.

[0006] However, when replacing the bearings, it is necessary to disassemble and reassemble the heavy calender head, and generally, a plurality of rubber strip manufacturing devices are arranged in one molding machine according to the tire components used. Therefore, replacing the bearings takes a lot of time and places a large burden on the worker, so that a rubber strip manufacturing device that requires less frequent replacement of the bearings is desired.

[0007] Therefore, an object of the present invention is to provide a rubber strip manufacturing apparatus that can suppress the occurrence of damage to the bearings over a long period of time and reduce the frequency of replacing the bearings. [Means for solving the problem]

[0008] The present inventors have conducted extensive research into solving the above problems, and have found that the above problems can be solved by the invention described below, thereby completing the present invention.

[0009] The invention described in claim 1 is A rubber strip manufacturing apparatus comprising: a rubber extruder; and a calender head having a pair of calender rolls, the apparatus producing a tape-shaped rubber strip by rolling a rubber composition extruded from the rubber extruder into a predetermined shape with the pair of calender rolls, The rotating shaft of the calender roll supported by the bearing is inserted into an insertion hole provided in a side portion of the calender head, A collar having an outer diameter larger than the diameter of the insertion hole is fitted on the peripheral surface of the side edge of the calender roll so as to cover the gap between the rotation shaft of the calender roll and the insertion hole. And, The collar is made of steelThe rubber strip manufacturing apparatus is characterized by the above.

[0011] Claim 2 The invention described in 4. The method according to claim 1, wherein the steel is a polished steel bar. 1 2 is a rubber strip manufacturing apparatus according to the first embodiment.

[0012] Claim 3 The invention described in 2. The method according to claim 1, wherein the collar is formed as a single ring-shaped piece. Or claim 2 2 is a rubber strip manufacturing apparatus according to the first embodiment. Effect of the Invention

[0013] According to the present invention, it is possible to provide a rubber strip manufacturing apparatus that can suppress the occurrence of damage to the bearings over a long period of time and reduce the frequency of replacing the bearings. [Brief description of the drawings]

[0014] [Figure 1] FIG. 2 is a schematic cross-sectional view of a calender head of the rubber strip manufacturing apparatus according to the present embodiment. [Diagram 2] 2 is a schematic cross-sectional view of the vicinity of a bearing portion of a calender head of the rubber strip manufacturing apparatus according to the present embodiment. FIG. [Diagram 3] FIG. 2 is a diagram showing an example of a color used in one embodiment of the present invention. [Figure 4] FIG. 1 is a schematic diagram showing an outline of a rubber strip manufacturing apparatus. [Diagram 5] FIG. 1 is a schematic cross-sectional view of a calender head of a conventional rubber strip manufacturing apparatus. [Figure 6] FIG. 1 is a schematic cross-sectional view of the vicinity of a bearing portion of a calender head of a conventional rubber strip manufacturing apparatus. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] 1. Conventional rubber strip manufacturing equipment and its problems The present inventors considered that in order to reduce the frequency of replacing bearings in rubber strip manufacturing equipment, it was necessary to first understand the cause of bearing damage, and conducted various experiments and studies. As a result, it was found that the rubber composition enters the rotating shaft of the calendar roll through a gap between the rotating shaft of the calendar roll and an insertion hole formed so that the rotating shaft of the calendar roll can be inserted, causing damage to the bearings arranged around the rotating shaft. The details will be described below.

[0016] FIG. 4 is a schematic diagram showing an outline of a rubber strip production apparatus, which is equipped with a rubber extruder and a calendar head. Rubber extruded from an extrusion port of the rubber extruder is rolled to a predetermined width and thickness by a pair of upper and lower calendar rolls of the calendar head, thereby forming a rubber strip having a predetermined cross-sectional shape. In this respect, the conventional rubber strip production apparatus and the rubber strip production apparatus of the present invention are basically the same.

[0017] Specifically, the rubber strip manufacturing apparatus 1 includes a rubber extruder 11 and a calender head 12. A rubber composition G extruded from an extrusion port 11a of the rubber extruder 11 is rolled to a predetermined width and thickness by a pair of upper and lower calender rolls 121, 122 of the calender head 12, thereby forming a rubber strip GS having a predetermined cross-sectional shape. Thereafter, the formed rubber strip GS is taken up by a take-up roll 13 and sent to the next process.

[0018] Fig. 5 is a schematic cross-sectional view of a calender head of a conventional rubber strip manufacturing apparatus. Fig. 6 is a schematic cross-sectional view of the vicinity of a bearing portion of the calender head of the conventional rubber strip manufacturing apparatus, and is a schematic cross-sectional view of the vicinity of the bearing portion on the right side of the page of the upper roll 31a shown in Fig. 5. In Figs. 5 and 6, 3 is the calender head, 31 is the calender roll, and 34 is a housing.

[0019] As shown in Fig. 5, the calender head 3 includes a calender roll 31 consisting of a pair of upper and lower rolls, an upper roll 31a and a lower roll 31b. The peripheral surface of one of the rolls (the upper roll 31a in Fig. 5) is provided with a circumferential groove 32 that corresponds to the cross-sectional shape (width, thickness) of the target rubber strip GS.

[0020] The calender rolls 31 (upper roll 31a and lower roll 31b) are housed in a housing 34. Specifically, the rotating shafts 33 of the rolls 31a and 31b, supported by bearings 36 as bearings, are inserted into insertion holes provided in the side portions (side plates 35) of the housing 34, thereby being housed in the housing 34. Note that lubricating oil is filled around the bearings 36 to maintain slidability between the rotating shafts 33 and the bearings 36.

[0021] One end of each of the rotating shafts 33 of the upper roll 31a and the lower roll 31b extends to the outside of a side plate 35 of the housing, and a gear 37 is attached to each of them. The gears mesh with each other, and when one gear is rotated, the other gear also rotates, so that the upper roll 31a and the lower roll 31b rotate in conjunction with each other.

[0022] At this time, a small clearance (gap 35a) is formed between each of the rotary shafts 33 and the insertion holes so that the upper roll 31a and the lower roll 31b can rotate smoothly.

[0023] During the production of a rubber strip, some factors such as extrusion conditions or rolling conditions may cause the rubber composition to adhere excessively to the rolls, making it impossible to obtain a rubber strip with a predetermined cross-sectional shape. As a countermeasure, the rubber strip production apparatus is temporarily stopped (a so-called "momentary stop"). At that time, the rubber composition on the rolls moves from the center of the rolls to the side edges.

[0024] The rubber composition that has moved to the side edge of the roll then penetrates into the inside of the side plate 35 through the gap 35a between the rotating shaft 33 and the insertion hole, as shown in Fig. 6. The infiltrating rubber composition then mixes with the lubricating oil filled around the bearing 36, causing a decrease in lubrication, and it was found that this ultimately leads to damage to the bearing 36.

[0025] Therefore, in the conventional rubber strip manufacturing apparatus, it is necessary to periodically inspect the calender head. Specifically, the calender head is disassembled to check the intrusion state of the rubber composition, and after replacing the bearings as necessary, the calender head is reassembled. However, as described above, disassembling and reassembling the heavy calender heads for each of the rubber strip manufacturing apparatuses arranged in a single molding machine takes a lot of time and places a heavy burden on the workers, so that it has been desired to reduce the frequency of replacing the bearings.

[0026] 2. Rubber strip manufacturing apparatus according to the present invention (1) Basic Concept of the Invention The present inventors considered that in order to reduce the frequency of replacing the bearings in the above-mentioned rubber strip manufacturing apparatus, it was necessary to prevent the rubber composition from entering through the gap between the rotating shaft and the insertion hole, and conducted extensive experiments and studies on specific methods for preventing the intrusion.

[0027] As a result, the inventors came up with the idea of ​​fitting a collar around the peripheral surface of the side edge of the calender roll so as to cover the gap between the rotation shaft of the calender roll and the insertion hole.

[0028] That is, when a collar having an outer diameter larger than the diameter of the insertion hole is fitted to the peripheral surface of the side edge of the calendar roll so as to cover the gap between the rotating shaft of the calendar roll and the insertion hole, even if the rubber composition on the roll moves from the center of the roll to the side edge during the above-mentioned momentary stop, the rubber composition moves radially outward along the fitted collar and does not penetrate into the inside of the side plate through the gap. As a result, the occurrence of damage to the bearing due to the penetration of the rubber composition is sufficiently suppressed, and it is not necessary to replace the bearing until the end of its life, and the frequency of replacement of the bearing can be reduced.

[0029] (2) Specific embodiments of the invention The following describes the present invention based on specific embodiments.

[0030] As described above, the rubber strip manufacturing apparatus according to this embodiment includes a rubber extruder and a calender head, and is configured basically the same as a conventional rubber strip manufacturing apparatus in that rubber extruded from an extrusion port of the rubber extruder is rolled to a predetermined width and thickness by a pair of upper and lower calender rolls of the calender head to form a rubber strip having a predetermined cross-sectional shape.

[0031] However, the rubber strip manufacturing apparatus according to the present embodiment differs from the conventional rubber strip manufacturing apparatus in that, as described above, a collar is fitted onto the peripheral surface of the side edge portion of the calender roll so as to cover the gap between the rotation shaft of the calender roll and the insertion hole.

[0032] Fig. 1 is a schematic cross-sectional view of a calender head of a rubber strip manufacturing apparatus according to this embodiment. Fig. 2 is a schematic cross-sectional view of the vicinity of a bearing portion of the calender head of the rubber strip manufacturing apparatus according to this embodiment, and is a schematic cross-sectional view of the vicinity of the bearing portion on the right side of the paper surface of the upper roll 31a shown in Fig. 1. Fig. 3 is a diagram showing an example of a collar used in this embodiment. In Figs. 1 and 2, the reference characters other than the collar 38 are the same as those in Figs. 5 and 6.

[0033] As shown in FIG. 1, the calendar head of this embodiment is different from the conventional calendar heads shown in FIGS. 5 and 6 in that a collar 38 is fitted around the circumferential surface of the side edge of the rotating shaft 33 of the roll so as to cover the gap 35a between the rotating shaft 33 and the insertion hole.

[0034] As shown in Figs. 2 and 3, the collar 38 has an outer diameter R larger than the diameter r of the insertion hole. By providing such a collar 38, even if the rubber composition G on the roll moves from the center of the roll (the upper roll 31a in Fig. 2) to the side edge, the rubber composition G moves further in the radial outward direction of the roll along the collar 38, and does not invade the inside of the side plate 35 through the gap 35a. As a result, the occurrence of damage to the bearing due to the intrusion of the rubber composition can be sufficiently suppressed, and it is not necessary to replace the bearing until the end of the bearing's life, so that the frequency of replacing the bearing can be reduced. The collar 38 can be fixed, for example, by screwing it to the peripheral surface of the side edge of the rotating shaft 33.

[0035] As described above, in the present embodiment, there is no need to make major modifications to the calender head itself, and such collars are available at low cost. Therefore, even when a conventional rubber strip manufacturing apparatus is modified, an increase in cost can be sufficiently suppressed.

[0036] In this embodiment, considering that the collar 38 is fitted into the roll and rotates together with the roll, a steel collar having excellent strength and durability is preferable, and among these, a collar made of polished steel bar such as SS400D is preferable.

[0037] The collar 38 may be formed by combining a plurality of members, but in consideration of manufacturing costs, it is preferable that the collar 38 be formed as a single ring-shaped member.

[0038] As described above, according to this embodiment, the occurrence of damage to the bearing due to the penetration of the rubber composition can be sufficiently suppressed, so that it is no longer necessary to replace the bearing until just before the end of its lifespan (approximately 10 years), and the frequency of bearing replacement can be significantly reduced.

[0039] Although the present invention has been described above based on the embodiment, the present invention is not limited to the above embodiment. Various modifications can be made to the above embodiment within the same and equivalent scope of the present invention. [Explanation of symbols]

[0040] 1. Rubber strip manufacturing equipment 3, 12 Calendar Head 11 Rubber extruder 11a: Extrusion port of rubber extruder 13 Take-off roll 31, 121, 122 Calendar Roll 31a Upper roll 31b Lower Roll 32 Circumferential groove 33 (Roll) axis of rotation 34 Housing 35 (Housing) Side Plate 35a Gap 36 Bearings 37 Gear 38 Color G. Rubber composition GS Rubber Strip

Claims

1. A rubber strip manufacturing apparatus comprising: a rubber extruder; and a calender head having a pair of calender rolls, the apparatus producing a tape-shaped rubber strip by rolling a rubber composition extruded from the rubber extruder into a predetermined shape with the pair of calender rolls, The rotating shaft of the calender roll supported by the bearing is inserted into an insertion hole provided in a side portion of the calender head, a collar having an outer diameter larger than a diameter of the insertion hole is fitted on a peripheral surface of a side edge of the calender roll so as to cover a gap between a rotation shaft of the calender roll and the insertion hole; 13. An apparatus for manufacturing rubber strips, comprising: a collar made of steel;

2. 2. The rubber strip manufacturing apparatus according to claim 1, wherein the steel is a polished steel bar.

3. 3. The rubber strip manufacturing apparatus according to claim 1, wherein the collar is formed as a ring-shaped integral part.

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