CN116394566A - Bead core covering device - Google Patents

Abstract

The invention provides a bead core coating device, which comprises an extruder, a rotating drum, a covering device and a control part, wherein the covering device rotatably supports the bead core in a way that the outer peripheral surface of the rotating drum is close to the inner peripheral surface of the bead core, the control part controls the extruder, the rotating drum and the covering device so that a rubber sheet extruded from the extruder is wound on the outer peripheral surface of the rotating drum from the front end, a part of the width direction of the rubber sheet positioned on the outer peripheral surface of the rotating drum is adhered on the inner peripheral surface of the rotating bead core from the front end, the remaining part of the width direction of the rubber sheet adhered on the inner peripheral surface of the bead core is wound along the cross section shape of the bead core by the covering device, and the rotating shaft of the rotating drum is arranged on the same plane as the rotating shaft of the bead core and is inclined relative to the rotating shaft of the bead core.

Description

Bead core covering device

technical field

The present disclosure relates to bead core wrapping devices.

Background technique

Generally, a bead of a pneumatic tire is provided with an annular bead core in which a bundled body such as a steel wire is covered with rubber. The surface of the bead core is sometimes covered with a thin rubber sheet in order to integrate steel wires and the like. The rubber sheet is also sometimes referred to as cover rubber or bead cover rubber.

The following Patent Document 1 discloses a bead core covering method, which includes: a step of winding a rubber sheet extruded from an extruder onto the outer peripheral surface of a rotating drum from the front end; A step of affixing a part of the rubber sheet located on the outer peripheral surface of the rotary drum in the width direction from the front end to the outer surface of the rotating bead core until it goes around the entire circumference of the outer peripheral surface of the rotary drum and a step of winding the remaining portion in the width direction of the rubber sheet attached to the outer surface of the bead core along the cross-sectional shape of the bead core. That is, in the bead core covering method of Patent Document 1, after the rubber sheet extruded from the extruder is once wound around the outer peripheral surface of the rotating drum, the rubber sheet on the rotating drum is pasted on the outside of the bead core. surface. Accordingly, it is possible to prevent the size of the rubber sheet extruded from the extruder from changing, and to cover the bead core with the rubber sheet with high precision.

However, in the bead core covering method of Patent Document 1, for example, from the viewpoint of increasing the circumferential contact area between the rubber sheet on the rotating drum and the bead core to facilitate the adhesion of the rubber sheet to the bead core Starting from this, it is desirable to install the extruder and the rotary drum on the inner peripheral side of the bead core, and to increase the drum diameter of the rotary drum as much as possible. However, in the structure in which the extruder and the rotating drum are arranged on the inner peripheral side of the bead core, it is difficult to increase the drum diameter of the rotating drum because the size of the inner diameter of the bead core is restricted. Therefore, in order to increase the drum diameter of the rotary drum, it is necessary to improve the arrangement of the rotary drum and the bead core.

FB223624JP-I

prior art literature

patent documents

Patent Document 1: Japanese Patent Laid-Open No. 2019-51670

Contents of the invention

The problem to be solved by the invention

An object of the present disclosure is to provide a bead core covering device capable of increasing the drum diameter of the rotating drum in an apparatus for adhering a rubber sheet extruded from an extruder to a bead core via the rotating drum.

Technical solutions for solving problems

The bead core covering device of the present disclosure is a bead core covering device that covers an annular bead core with a strip-shaped rubber sheet, and includes:

an extruder, which extrudes the rubber sheet;

a rotating drum that winds the rubber sheet extruded from the extruder;

a covering device for covering the tire so that the outer peripheral surface of the rotating drum approaches the inner peripheral surface of the bead core at a position downstream of the extruder in the rotating direction of the rotating drum. the ring core is rotatably supported; and

a control unit that controls the extruder, the rotating drum, and the covering device so that the rubber sheet extruded from the extruder is wound onto the outer peripheral surface of the rotating drum from the front end, Before the rubber sheet is wound around the entire circumference of the outer peripheral surface of the rotating drum, a portion of the rubber sheet positioned on the outer peripheral surface of the rotating drum in the width direction is attached to the rotating drum from the front end. the inner peripheral surface of the bead core, and the remaining part in the width direction of the rubber sheet pasted on the inner peripheral surface of the bead core is wound along the cross-sectional shape of the bead core by the covering device,

The rotation axis of the rotary drum is arranged obliquely with respect to the rotation axis of the bead core on the same plane as the rotation axis of the bead core.

Description of drawings

FIG. 1 is a front view schematically showing an example of the structure of a bead core covering device.

Fig. 2 is a sectional view taken along line II-II of the bead core covering device of Fig. 1 .

Fig. 3 is a sectional view of the bead core.

Detailed ways

Hereinafter, one embodiment of the bead core covering device will be described with reference to the drawings. In addition, in each drawing, the dimensional ratios in the drawings do not necessarily match the actual dimensional ratios, and the dimensional ratios between the drawings do not necessarily match.

The bead core covering device of the present embodiment covers an annular bead core with a long strip-shaped rubber sheet having a predetermined width. In addition, although the bead core of the present embodiment has been described as having a hexagonal cross-section, it is not limited thereto, and the cross-sectional shape of the bead core may be quadrangular, circular, or the like.

FIG. 1 is a front view schematically showing an example of the structure of a bead core covering device 1 . Fig. 2 is a sectional view taken along line II-II of the bead core covering device 1 in Fig. 1 . The bead core covering device 1 includes an extruder 2 , a rotary drum 3 , a covering device 4 , and a control unit (not shown) that controls the extruder 2 , the rotating drum 3 and the covering device 4 . In addition, in the sectional view of FIG. 2, the part other than the rotating drum 3, the rubber sheet S, and the bead core 8 is drawn in planar view.

In the following description, as shown in FIGS. 1 and 2 , the direction parallel to the central axis of the annular bead core 8 is referred to as the X direction, and the radial direction of the bead core 8 is referred to as the Y direction. The direction perpendicular to the X direction and the Y direction is defined as the Z direction. In addition, when expressing directions, when distinguishing between positive and negative directions, such as "+X direction" and "-X direction", add plus and minus symbols to describe, and when expressing directions without distinguishing between positive and negative directions In this case, only "X direction" is described.

The extruder 2 has a cylindrical barrel 2a, a hopper 2b connected to the supply port of the barrel 2a, a screw (not shown) for kneading rubber in the barrel 2a and sending it to the front end side, and a rotary A screw motor 2c for driving the screw. The operation of the screw motor 2c is controlled by the controller.

A gear pump 20 is connected to the front end side of the extruder 2 in the extrusion direction, and the front end side of the gear pump 20 is connected to a die 21 . The rubber material kneaded by the extruder 2 is supplied to the gear pump 20 . The gear pump 20 has an end surface 20b, and a discharge port (not shown) is formed on the end surface 20b. The gear pump 20 discharges the rubber supplied from the extruder 2 from the discharge port, and supplies a fixed amount of rubber to the die 21 . The rubber sheet S is extruded from the die 21 at a predetermined extrusion rate.

The gear pump 20 has a pair of gears 20 a and has a function of sending rubber to the die 21 . The pair of gears 20a are rotationally driven by a gear motor (not shown), and the operation of the gear motor is controlled by a control unit. The extruded amount of the rubber sheet S extruded from the die 21 can be controlled by interlocking and controlling the rotational speed of the gear motor and the rotational speed of the screw motor 2c by the control unit.

In addition, in this embodiment, an example in which a so-called external gear pump is used in which the gear pump 20 is connected to the front end side of the extruder 2 in the extrusion direction is shown. However, a gear-pump built-in extruder having a gear pump built in the extruder may be used instead. In the present disclosure, compared with an extruder connected with an external gear pump, the extruder with a built-in gear pump can more easily control the extrusion amount, and does not require a motor for gears, so the front end of the extruder becomes compact , is more preferable.

The extruder 2, the gear pump 20, and the die 21 are configured to be able to move forward and backward in the extrusion direction as a whole by a forward and backward drive device (not shown). The extruder 2 approaches the rotary drum 3 by advancing, and moves away from the rotary drum 3 by retreating. The movement of the front and rear driving devices is also controlled by the control unit.

The rotary drum 3 is configured to be rotatable around a rotary shaft 3 r by a servo motor 30 . The operation of the servo motor 30 is controlled by the control unit. The rubber sheet S extruded through the die 21 is supplied to the outer peripheral surface 3 a of the rotary drum 3 , and the rotary drum 3 is rotationally driven in the R1 direction with the rubber sheet S stuck thereon, whereby the rubber sheet S can be wound in the circumferential direction. The outer peripheral surface 3a of the rotary drum 3 is made of metal. The outer diameter (hereinafter also referred to as drum diameter) of the rotary drum 3 is, for example, 200 to 400 mm.

The rotary drum 3 preferably includes a cooling mechanism for cooling the outer peripheral surface 3 a or a heating mechanism for heating the outer peripheral surface 3 a (both are not shown). As the cooling mechanism or the heating mechanism, for example, a mechanism that circulates cooling water or warm water inside the rotary drum 3 is used. In addition, the outer peripheral surface 3 a of the rotary drum 3 is subjected to a surface treatment to make the attached rubber sheet S easy to peel off or to use the above-mentioned material.

The covering device 4 covers the bead core 8 so that the outer peripheral surface 3 a of the rotary drum 3 and the inner peripheral surface of the bead core 8 are close to each other at a position downstream of the extruder 2 in the rotation direction R1 of the rotary drum 3 . Supported by rotation. The bead core 8 rotates around the rotation axis 4r. The drum diameter of the rotary drum 3 is smaller than the inner diameter of the bead core 8 , and the rotary drum 3 is arranged on the inner peripheral side of the bead core 8 supported by the covering device 4 in a front view. The drum diameter of the rotary drum 3 is preferably 0.3 times or more, more preferably 0.4 times or more, the inner diameter of the bead core 8 . By setting the drum diameter of the rotary drum 3 to 0.3 times or more the inner diameter of the bead core 8, the circumferential contact area between the rubber sheet S on the rotary drum 3 and the bead core 8 becomes large, so that the rubber sheet S can be easily moved. Paste on the bead core 8. In addition, since the drum diameter of the rotating drum 3 is different from the inner diameter of the bead core 8, the rubber sheet S and the bead core 8 theoretically come into line contact with each other, but in practice, the rubber sheet S is deformed due to being pressed when pasted. Therefore, they may be in surface contact with each other. By making the drum diameter of the rotating drum 3 close to the inner diameter of the bead core 8, the circumferential contact length between the rubber sheet S and the bead core 8 increases, so the circumferential contact length between the rubber sheet S and the bead core 8 increases. The contact area becomes larger. Although not particularly limited, the circumferential contact length between the rubber sheet S and the bead core 8 is about 2 to 5 mm.

The covering device 4 is used to wind the rubber sheet S stuck on the inner peripheral surface of the bead core 8 along the cross-sectional shape of the bead core 8 . The covering device 4 can rotate the supported bead core 8 in the R2 direction. The bead core 8 is driven to rotate by the rotation of the rotary drum 3 .

FIG. 3 shows a cross-sectional view of the bead core 8 . The bead core 8 has a cross-sectional hexagonal shape and has an inner peripheral surface 8a, an outer peripheral surface 8d, a pair of lower side surfaces 8b and 8f on the inner peripheral side, and a pair of upper side surfaces 8c and 8e on the outer peripheral side.

The inner peripheral surface 8 a is inclined with respect to the rotation axis 4 r of the bead core 8 . The inclination angle θ1 of the inner peripheral surface 8 a with respect to the rotation axis 4 r of the bead core 8 is 15 to 20 degrees. Also, in the present disclosure, the inner peripheral surface 8a of the bead core 8 is the inclination of the outer surface (outer surfaces 8a to 8f in this embodiment) of the bead core 8 with respect to the rotation axis 4r of the bead core 8 The face with the smallest angle.

The inner diameter of the bead core 8 is, for example, 400 to 650 mm. In addition, the inner diameter of the bead core 8 refers to the diameter at the position closest to the rotation axis 4r on the inner peripheral surface 8a, and in the bead core 8 shown in FIG. The diameter of the circle formed by the lines.

A rubber sheet S is wound around the outer surface of the bead core 8 . The belt-shaped rubber sheet S is first attached to the inner peripheral surface 8a of the bead core 8 at the central portion in the width direction, and then one side in the width direction is attached to the lower side 8b, the upper side 8c, and the outer peripheral surface 8d in order, and the The other side in the width direction is stuck to the lower side 8f, the upper side 8e, and the outer peripheral surface 8d in this order.

The covering device 4 includes a pressing roller 41 . The pressing roller 41 is disposed at a position facing the rotary drum 3 with a part of the bead core 8 interposed therebetween. As shown in FIG. 2 , the pressing roller 41 is a so-called flanged roller having a roller main body 411 and a flange 412 provided at an axial end of the roller main body 411 .

The rotation axis 41A of the pressing roller 41 is substantially parallel to the rotation axis 3 r of the rotary drum 3 , and the pressing roller 41 rotates while the outer peripheral surface of the roller body 411 is in contact with the outer peripheral surface 8 d of the bead core 8 . In addition, the pressing roller 41 is configured to be movable back and forth toward the bead core 8 . Thus, when the central portion in the width direction of the rubber sheet S positioned on the outer peripheral surface 3 a of the rotary drum 3 is attached to the inner peripheral surface 8 a of the rotating bead core 8 , the pressing roller 41 can press the outer periphery of the bead core 8 . Face 8d. Furthermore, the pressing roller 41 is a driven roller that is driven to rotate by the rotation of the bead core 8 .

The bead core 8 is pressed from the rotating drum 3 to apply a force in the +X direction when the rubber sheet S is attached to the inner peripheral surface 8a. The movement of the bead core 8 in the +X direction can be restricted by providing the pressing roller 41 with the flange 412 .

The covering device 4 includes a plurality of rollers 42 to 46 in order to wind the rubber sheet S along the cross-sectional shape of the bead core 8 . The plurality of rollers 42 to 46 are not particularly limited, and each has the following functions. The roller 42 sticks the rubber sheet S to the lower side surfaces 8b and 8f, for example. The roller 44 sticks the rubber sheet S to, for example, the upper side surface 8c and the outer peripheral surface 8d. The roller 45 sticks the rubber sheet S to, for example, the upper side surface 8e and the outer peripheral surface 8d. The rollers 43 bend both ends of the rubber sheet S in the width direction toward the bead core 8 so that the rubber sheets S can be easily attached to the upper surfaces 8c, 8e and the outer peripheral surface 8d by the rollers 44 and 45 . The rollers 46 press-contact both ends of the rubber sheet S in the width direction to the outer peripheral surface 8 d of the bead core 8 . In addition, auxiliary rollers are disposed at positions facing the rollers 42 , 44 , 45 , and 46 with the bead core 8 interposed therebetween. In addition, the covering device 4 includes a plurality of guide rollers 47 for preventing meandering of the rotating bead core 8 .

Next, the positional relationship between the rotary drum 3 and the bead core 8 will be described. As shown in FIG. 1 , the rotation axis 3r of the rotary drum 3 and the rotation axis 4r of the bead core 8 are arranged on the same XY plane. In addition, as shown in FIG. 2 , the rotation axis 3r of the rotary drum 3 is provided obliquely with respect to the rotation axis 4r of the bead core 8 . As a result, the overlap between the rotating drum 3 and the bead core 8 can be reduced when viewed in the Z direction, so that the drum diameter of the rotating drum 3 can be increased to approach the inner diameter of the bead core 8 . By increasing the drum diameter of the rotary drum 3 , the circumferential contact area between the rubber sheet S on the rotary drum 3 and the bead core 8 becomes larger, so that the rubber sheet S is easily attached to the bead core 8 . In addition, by increasing the drum diameter of the rotary drum 3, the cooling effect of the cooling mechanism on the outer peripheral surface 3a can be easily obtained, and troubles such as the rubber sheet S not peeling off from the outer peripheral surface 3a can be prevented. Further, since the curvature of the outer peripheral surface 3a can be reduced by increasing the drum diameter of the rotary drum 3, it is easy to adjust the thickness of the rubber sheet S formed in the gap between the die 21 and the outer peripheral surface 3a.

The inclination angle θ2 of the rotation axis 3r of the rotary drum 3 with respect to the rotation axis 4r of the bead core 8 is 15±10 degrees, preferably 15±5 degrees. In addition, the inclination angle θ2 is an angle on a plane (XY plane in this embodiment, as described above) including the rotation axis 3r of the rotary drum 3 and the rotation axis 4r of the bead core 8 . If the inclination angle θ2 is less than 5 degrees, the overlapping of the rotary drum 3 and the bead core 8 increases when viewed in the Z direction, and thus it becomes difficult to increase the drum diameter of the rotary drum 3 . If the inclination angle θ2 is larger than 25 degrees, the difference from the inclination angle θ1 becomes large, and it becomes difficult to properly stick the rubber sheet S to the inner peripheral surface 8 a of the bead core 8 .

The inclination angle θ2 is preferably in the range of ±5 degrees relative to the inclination angle θ1, more preferably in the range of ±2 degrees, and particularly preferably in the range of ±0 degrees. That is, the inclination angle θ2 is particularly preferably the same as the inclination angle θ1, and is, for example, 15 to 20 degrees. If the inclination angle θ2 exceeds the range of ±5 degrees relative to the inclination angle θ1, it will be difficult to stick the rubber sheet S on the rotary drum 3 to the inner peripheral surface 8a of the bead core 8 .

Next, the positional relationship between the extruder 2 and the rotary drum 3 will be described. As shown in FIG. 1 , the discharge port formed on the end surface 20 b of the gear pump 20 is arranged on the same XY plane as the rotation axis 3 r of the rotary drum 3 . On the XY plane including the discharge port of the gear pump 20 and the rotating shaft 3 r of the rotating drum 3 , the end surface 20 b of the gear pump 20 is arranged obliquely with respect to the outer peripheral surface 3 a of the rotating drum 3 . The angle θ3 formed by the end surface 20b of the gear pump 20 and the outer peripheral surface 3a of the rotary drum 3 is 30 degrees or less, preferably 20 degrees or less. By setting the angle θ3 to 30 degrees or less, the bending of the rubber flow path formed inside the die 21 can be reduced, so that the flow velocity difference in the opening width direction of the die 21 can be reduced.

As described above, the bead core covering device 1 according to the present embodiment is a bead core covering device 1 for covering the ring-shaped bead core 8 with the belt-shaped rubber sheet S, and includes the extruder 2 , which extrudes the rubber sheet S; the rotating drum 3, which winds the rubber sheet S extruded from the extruder 2; The position makes the outer peripheral surface 3a of the rotary drum 3 approach the inner peripheral surface 8a of the bead core 8, and the bead core 8 is rotatably supported; and the control unit controls the extruder 2, the rotary drum 3 And the covering device 4, so that the rubber sheet S extruded from the extruder 2 is wound on the outer peripheral surface 3a of the rotary drum 3 from the front end, before the rubber sheet S enters the entire circumference of the outer peripheral surface 3a of the rotary drum 3, A part of the width direction of the rubber sheet S located on the outer peripheral surface 3 a of the rotating drum 3 is stuck to the inner peripheral surface 8 a of the rotating bead core 8 from the front end, and is pasted on the inner peripheral surface of the bead core 8 by the covering device 4 . The remaining part of the width direction of the rubber sheet S on the surface 8a is wound along the cross-sectional shape of the bead core 8, and the rotation axis 3r of the rotary drum 3 is opposite to the bead core 8 on the same plane as the rotation axis 4r of the bead core 8. The rotating shaft 4r is arranged obliquely.

According to this configuration, the overlapping of the rotating drum 3 and the bead core 8 can be reduced when viewed in the Z direction, so the drum diameter of the rotating drum 3 can be increased to be close to the inner diameter of the bead core 8 .

In addition, in the bead core coating device 1 according to the present embodiment, the rotation axis 3r of the rotary drum 3 is inclined at an angle θ2 of 15±10 degrees with respect to the rotation axis 4r of the bead core 8 .

According to this configuration, the drum diameter of the rotary drum 3 can be increased. Furthermore, even in the case of the bead core 8 in which the inner peripheral surface 8a is inclined with respect to the rotation axis 4r of the bead core 8 as shown in FIG. Inner peripheral surface 8a.

In addition, the bead core coating device 1 according to the present embodiment is configured to include a gear pump 20 connected to the front end side of the extruder 2 in the extrusion direction, and the end surface 20b is formed to discharge the pump from the extruder. 2. A discharge port for supplied rubber; and a die 21, which is connected to the front end side of the gear pump 20 in the extrusion direction, and extrudes the rubber supplied from the gear pump 20 as a rubber sheet S. The angle θ3 formed by the end surface 20b of the gear pump 20 and the outer peripheral surface 3a of the rotary drum 3 in the plane of the rotating shaft 3r is 30 degrees or less.

According to this structure, since the curvature of the rubber flow path formed inside the die 21 can be reduced, the flow velocity difference in the opening width direction of the die 21 can be reduced.

In addition, in the bead core coating device 1 according to the present embodiment, the drum diameter of the rotary drum 3 is configured to be 0.3 times or more the inner diameter of the bead core 8 .

According to this structure, the contact area in the circumferential direction between the rubber sheet S on the rotary drum 3 and the bead core 8 becomes large, so that the rubber sheet S is easily attached to the bead core 8 .

In addition, in the bead core covering device 1 according to the present embodiment, the covering device 4 is configured such that the covering device 4 includes the pressing roller 41 that presses the bead core 8 so as to face the rotating drum 3 with the bead core 8 in between, and the pressing roller 41 has a The roller main body 411 and the flange 412 provided at the axial end of the roller main body 411 .

According to this configuration, when the rubber sheet S is attached to the inner peripheral surface 8a, the bead core 8 can be prevented from being pressed from the rotary drum 3 and moving in the axial direction.

As mentioned above, although embodiment of this disclosure was described based on drawing, a specific structure is not limited to these embodiment. The scope of the present disclosure is shown not only by the description of the above-mentioned embodiments but also by claims, and includes meanings equivalent to the claims and all changes within the range.

The structures employed in the above-described embodiments can be used in other arbitrary embodiments. The specific configuration of each part is not limited to the above-mentioned embodiment, and various modifications are possible without departing from the gist of the present disclosure.

(1) In the bead core coating device 1 according to the above embodiment, the rotation axis 3r of the rotary drum 3 is inclined at an angle θ2 of 15±10 degrees with respect to the rotation axis 4r of the bead core 8 . However, the bead core covering device 1 is not limited to this structure. For example, when the inclination angle θ1 of the inner peripheral surface 8 a of the bead core 8 with respect to the rotating shaft 4 r is smaller than 15 degrees, it may be preferable to make the inclination angle θ2 smaller than 15 degrees.

(2) In the bead core covering device 1 according to the above-mentioned embodiment, the gear pump 20 is connected to the front end side of the extruder 2 in the extrusion direction, and the end surface 20 b is formed with a discharge pump 20 from the extruded pump. The discharge port of the rubber supplied by the machine 2; and the die 21, which is connected to the front end side of the gear pump 20 in the extrusion direction, and extrudes the rubber supplied from the gear pump 20 as a rubber sheet S. The angle θ3 formed by the end surface 20 b of the gear pump 20 and the outer peripheral surface 3 a of the rotary drum 3 in a plane including the discharge port and the rotary shaft 3 r of the rotary drum 3 is 30 degrees or less. However, the bead core covering device 1 is not limited to this structure. For example, when the die 21 has a mechanism capable of reducing the flow velocity difference in the opening width direction, the angle θ3 can be made larger than 30 degrees, thereby further increasing the drum diameter of the rotary drum 3 . In addition, in the above embodiment, the end surface 20b of the gear pump 20 is inclined with respect to the outer peripheral surface 3a of the rotary drum 3 , but the present invention is not limited to this, and the end surface 20b of the gear pump 20 may be parallel to the outer peripheral surface 3a of the rotary drum 3 .

(3) In the bead core coating device 1 according to the above embodiment, the drum diameter of the rotary drum 3 is configured to be 0.3 times or more the inner diameter of the bead core 8 . However, the bead core covering device 1 is not limited to this structure. For example, when the inner diameter of the bead core 8 is sufficiently large, even if the drum diameter of the rotating drum 3 is made smaller than 0.3 times the inner diameter of the bead core 8, the rubber sheet S on the rotating drum 3 can be properly secured to the bead. The circumferential contact area between the cores 8 .

(4) In the bead core coating device 1 according to the above-mentioned embodiment, the position where the front end of the die 21 of the extruder 2 is closest to the outer peripheral surface 3 a of the rotary drum 3 and the inner portion of the bead core 8 The closest position of the peripheral surface 8a to the outer peripheral surface 3a of the rotary drum 3 is shifted by 180° in the rotation direction R1 of the rotary drum 3 , but the position is not limited thereto, and may be shifted by 90° or 270°.

Symbol Description

1...Bead core covering device

2…Extruder

3…rotating drum

3a...The outer peripheral surface of the rotating drum

3r... the axis of rotation of the rotating drum

4…covering device

4r...the axis of rotation of the bead core

8...Bead core

8a...Inner peripheral surface of the bead core

8b...The underside of the bead core

8c...The upper side of the bead core

8d...The outer peripheral surface of the bead core

8e...The upper side of the bead core

8f...The underside of the bead core

20…Gear pump

20a...gear

20b...The end face of the gear pump

21...die

41...press roller

41A...Rotating shaft of pressing roller

42～46...Rolls

47...Guide roller

411…Roller body

412...Flange

R1…The direction of rotation of the rotating drum

R2…The direction of rotation of the bead core

S…rubber sheet

θ1…The angle of inclination of the inner peripheral surface of the bead core relative to the rotation axis

θ2…The inclination angle of the rotation axis of the rotating drum relative to the rotation axis of the bead core

θ3...The angle formed by the end surface of the gear pump and the outer peripheral surface of the rotating drum.

Claims (5)

1. A bead core coating device for coating an annular bead core with a strip-shaped rubber sheet, wherein the bead core coating device comprises:

an extruder that extrudes the rubber sheet;

a rotating drum that winds the rubber sheet extruded from the extruder;

a covering device for rotatably supporting the bead core so that an outer peripheral surface of the rotating drum approaches an inner peripheral surface of the bead core at a position downstream of the extruder in a rotation direction of the rotating drum; and

a control unit that controls the extruder, the rotating drum, and the covering device such that the rubber sheet extruded from the extruder is wound around the outer peripheral surface of the rotating drum from the front end, a part of the rubber sheet in the width direction on the outer peripheral surface of the rotating drum is stuck to the inner peripheral surface of the rotating bead core from the front end before the rubber sheet is wound around the entire circumference of the outer peripheral surface of the rotating drum, and the remaining part of the rubber sheet in the width direction stuck to the inner peripheral surface of the bead core is wound along the cross-sectional shape of the bead core by the covering device,

the rotation axis of the rotating drum is disposed obliquely to the rotation axis of the bead core on the same plane as the rotation axis of the bead core.

2. The bead core cladding apparatus according to claim 1, wherein,

the rotation axis of the rotating drum is inclined at an angle of 15±10 degrees with respect to the rotation axis of the bead core.

3. Bead core cladding apparatus according to claim 1 or 2, wherein,

the bead core coating device comprises:

a gear pump connected to the front end side of the extruder in the extrusion direction, the gear pump having a discharge port formed in an end surface thereof for discharging rubber supplied from the extruder; and

a die connected to the front end side of the gear pump in the extrusion direction, for extruding the rubber supplied from the gear pump as the rubber sheet,

in a plane including the discharge port and the rotation axis of the rotary drum, an angle formed between an end surface of the gear pump and an outer peripheral surface of the rotary drum is 30 degrees or less.

4. Bead core cladding apparatus according to claim 1 or 2, wherein,

the drum diameter of the rotary drum is more than 0.3 times of the inner diameter of the bead core.

5. Bead core cladding apparatus according to claim 1 or 2, wherein,

the covering device is provided with a pressing roller for pressing the bead core opposite to the rotary drum through the bead core,

the pressing roller has a roller body and a flange provided at an axial end of the roller body.

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