CN105538734B

CN105538734B - Device and method for manufacturing rubber strip

Info

Publication number: CN105538734B
Application number: CN201510626364.5A
Authority: CN
Inventors: 山田裕史
Original assignee: Sumitomo Rubber Industries Ltd
Current assignee: Sumitomo Rubber Industries Ltd
Priority date: 2014-10-27
Filing date: 2015-09-28
Publication date: 2020-06-02
Anticipated expiration: 2035-09-28
Also published as: JP2016083862A; CN105538734A; JP6055454B2

Abstract

The invention provides a manufacturing device and a manufacturing method of a rubber strip, which can form the rubber strip into a preset shape with high precision. A rubber strip manufacturing apparatus (1) forms a strip-shaped rubber strip (Gs) made of unvulcanized rubber. The rubber strip manufacturing device (1) comprises: a rubber extrusion device (2) having an extrusion port (10) for preliminarily molding a rubber (G1) to be fed and extruding a preformed rubber (G2); a rolling device (3) for rolling the preformed rubber (G2) to form a rubber strip (Gs); a heating device (4) for heating the preformed rubber (G2) between the extrusion opening (10) and the rolling device (3).

Description

Device and method for manufacturing rubber strip

Technical Field

The invention relates to a manufacturing device and a manufacturing method of a rubber strip.

Background

Patent document 1 proposes a method of forming an unvulcanized green tire by sequentially winding a long rubber strip around the outer surface of a doughnut-shaped rigid core. The apparatus for manufacturing the rubber strip includes, for example: a rubber extrusion device having a gear pump for extruding a rubber to be charged and an extrusion port for preforming the rubber to form a preformed rubber; and a rolling device that shapes the rubber strip by rolling the preformed rubber.

However, the gear pump was temporarily stopped due to the interruption of the extrusion of the preformed rubber. When the gear pump is stopped, the preformed rubber exposed between the extrusion port and the rolling device is cooled by air, and as a result, shrinkage and hardening occur. When the operation of the gear pump is resumed, there is a problem that the preformed rubber cannot be molded into a predetermined shape of the rubber strip even if it is rolled by the rolling device.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2014-73590

Disclosure of Invention

The present invention has been made in view of the above circumstances, and a main object thereof is to provide a device and a method for manufacturing a rubber strip, which can suppress a decrease in temperature of a preformed rubber extending between a rubber extrusion device and a rolling device and can accurately form the rubber strip into a predetermined shape.

The present invention provides a rubber strip manufacturing apparatus for forming a strip-shaped rubber strip made of unvulcanized rubber, the rubber strip manufacturing apparatus including: a rubber extrusion device for preforming the charged rubber and extruding a preformed rubber, the rubber extrusion device having an extrusion port; a rolling device that shapes the rubber strip by rolling the preformed rubber; and a warming machine for warming the preformed rubber between the extrusion port and the calendering device.

In the apparatus for manufacturing a rubber strip according to the present invention, it is preferable that the warming machine includes a warm air blowing device for blowing warm air to the preformed rubber.

In the apparatus for producing a rubber strip according to the present invention, it is preferable that the rubber extrusion device includes a gear pump for extruding rubber into the extrusion port, the gear pump is alternately operated and stopped, and the heater heats the preformed rubber only when the gear pump is stopped.

The method for producing a rubber strip according to the present invention is a method for producing a belt-shaped rubber strip made of unvulcanized rubber, the method comprising: an extrusion step of extruding the charged rubber as a preformed rubber after preliminary molding; and a rolling step of rolling the preformed rubber and forming the rubber strip, wherein the extrusion step includes a rest state in which extrusion of the preformed rubber is temporarily stopped, and the preformed rubber before the rolling step is heated in the rest state.

[ Effect of the invention ]

The apparatus for manufacturing rubber strip of the present invention comprises: a rubber extrusion device having an extrusion port for preliminarily molding the rubber to be fed and extruding the preformed rubber; a rolling device for forming the rubber strip by rolling the preformed rubber; and a heating machine for heating the preformed rubber between the extrusion port and the calendering device. This suppresses the temperature of the preformed rubber extending between the extrusion port and the rolling device from decreasing, and thus suppresses shrinkage and hardening thereof. Therefore, the apparatus for manufacturing a rubber strip of the present invention can continuously form the rubber strip into a predetermined shape with high accuracy.

The method for manufacturing the rubber strip comprises the following steps: an extrusion step of extruding the charged rubber as a preformed rubber after preliminary molding; and a rolling step of rolling the preformed rubber to form the rubber strip, wherein the extrusion step includes a rest state in which the extrusion of the preformed rubber is temporarily stopped, and the preformed rubber before the rolling step is heated in the rest state. Thus, in the resting state, the temperature decrease of the preformed rubber exposed to the air is suppressed, and therefore, shrinkage and hardening thereof are suppressed. Therefore, the method for manufacturing a rubber strip of the present invention can continuously form the rubber strip into a predetermined shape with high accuracy.

Drawings

Fig. 1 is a side view showing a rubber strip manufacturing apparatus according to an embodiment of the present invention.

Fig. 2 is a side view of a manufacturing apparatus according to another embodiment.

Description of the symbols

1 apparatus for producing rubber strip

2 rubber extrusion device

3 calendering device

4 heating machine

10 extrusion opening

G1 rubber

G2 preformed rubber

Gs rubber strip

Detailed Description

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

Fig. 1 is a side view of a tire rubber strip manufacturing apparatus (hereinafter, may be simply referred to as "manufacturing apparatus") 1 according to the present embodiment. An applicator and a molding machine of a known configuration, not shown, for example, are provided downstream of the manufacturing apparatus 1. The applicator winds a belt-like rubber strip Gs made of unvulcanized rubber supplied from the manufacturing apparatus 1 around the outer peripheral surface of a rotating molding machine to mold a rubber member of a tire. After the rubber member is molded, the molding machine is stopped. The manufacturing apparatus 1 of the present embodiment also intermittently operates in accordance with the formation cycle of the rubber member, and manufactures the rubber strip Gs only when necessary.

As shown in fig. 1, the manufacturing apparatus 1 includes a rubber extrusion apparatus 2 and a rolling apparatus 3 disposed on the downstream side (hereinafter, simply referred to as "downstream side") in the rubber extrusion direction x.

The rubber extrusion device 2 is a device for preliminarily forming and intermittently extruding the charged material rubber G1, and includes, for example, a rubber extruder body 7, a gear pump 8 provided on the downstream side thereof, and a die plate 9 provided on the downstream side of the gear pump 8.

The rubber extruder main body 7 has a cylinder 7a provided with an inlet 7c for the material rubber G1, and a screw 7b disposed in the cylinder 7 a. The screw 7b is rotationally driven by, for example, a motor 7d, and kneads the input material rubber G1 and feeds it to the gear pump 8.

The gear pump 8 is a constant volume pump including a casing 8a and a pair of extrusion gears 8b provided in the casing 8 a. The extrusion gear 8b is rotationally driven by a motor not shown. Thereby, the rubber (not shown) extruded by the screw 7b is filled between the tooth grooves of the extrusion gear 8b and the housing 8a, and is pressure-fed to the die plate 9 in a fixed amount.

The die plate 9 includes a block-shaped head body 9a connected to the housing 8a of the gear pump 8 so as to be exchangeable, and a die opening 9b attached to the head body 9a so as to be exchangeable. An extrusion port 10 for preliminary molding is opened in the die 9 b.

The rubber extrusion apparatus 2 quantitatively extrudes the material rubber G1 fed from the feeding port 7c as the preformed rubber G2 from the extrusion port 10 by the gear pump 8 through the operation of the rubber extruder main body 7 and the gear pump 8 (extrusion step).

The rolling device 3 includes

rolling rolls

3a and 3b arranged vertically with a gap (gap). The upper and

lower reduction rolls

3a and 3b are disposed with their rotation axes substantially parallel to each other, and are rotatably supported by the frame 11. The frame 11 is fixed to a support member (not shown).

The upper rolling rolls 3a are supported by an elevating unit (not shown) that can be elevated with respect to the frame 11. This enables adjustment of the gap between the upper and

lower reduction rolls

3a and 3 b. The lower reduction roll 3b cooperates with, for example, a motor (not shown).

The preformed rubber G2 formed by the rubber extrusion device 2 is supplied between the upper and

lower reduction rolls

3a, 3 b. The preformed rubber G2 is rolled between the upper and

lower rollers

3a, 3b to form a rubber strip Gs having a predetermined cross-sectional shape (rolling step).

After the rolling step, the rubber strip Gs is wound around the outer peripheral surface (not shown) of the molding machine in order to mold the rubber member on the downstream side of the manufacturing apparatus 1.

When the rubber member is formed on the molding machine, the molding machine is stopped. While the molding machine is stopped, the extrusion process and the rolling process of the rubber strip Gs are temporarily stopped (stopped state). In the rest state, the upper reduction roll 3a is raised, and the pressure on the preformed rubber G2 is reduced. This suppresses, for example, breakage or the like due to a shift in the start-up of the rolling device 3 and the gear pump 8 during the restart.

In the rest state, the preformed rubber G2 joined between the die plate 9 and the rolling device 3 is exposed to air, and its temperature gradually decreases. Such a decrease in the temperature of the preformed rubber G2 causes shrinkage of the preformed rubber G2 and hardening of the rubber. Even if the shrunk and hardened preformed rubber G2 is rolled in the rolling step which is started again, the cross-sectional shape may not be the intended one. Therefore, in the present embodiment, in the resting state, a heating step of heating the preformed rubber G2 between the die plate 9 and the rolling device 3 is performed.

The warmer 4 is used in the warming step of the present embodiment. As long as the preformed rubber G2 extending between the die plate 9 and the rolling device 3 can be warmed, various warmers 4 can be used. As the warmer 4, various heaters are used, and for example, a warmer of a warm air blower type capable of supplying warm air is preferable. The heater 4 heats the preformed rubber G2 to suppress the temperature of the preformed rubber G2 extending between the die plate 9 and the rolling device 3 from decreasing, thereby suppressing shrinkage and hardening thereof. Therefore, the rubber strip Gs can be accurately molded. In particular, since the heater 4 capable of supplying warm air easily heats the entire preformed rubber G2, the rubber strip Gs can be molded with higher accuracy.

There is typically less space left between the die plate 9 and the calender 3. Therefore, it is preferable that the heater 4 includes, for example, a heater unit main body 4a that generates warm air, and an air guide duct 4b that guides the warm air from the heater unit main body 4a to the preformed rubber G2. The air guide pipe 4b is preferably flexible enough to be easily bent and deformed, and has heat resistance such as a copper pipe. This enables the warm air to be efficiently supplied to the preformed rubber G2 between the die plate 9 and the rolling device 3. The fan heater body 4a is preferably of an electric heating type or a heat pump type, for example. Thus, even if the installation position of the fan heater body 4a is separated from the preformed rubber G2, the air guide duct 4b can be deformed into a predetermined shape by bending or the like, and the air outlet 12 can be brought close to the preformed rubber G2.

The temperature of the warm air is preferably 60 degrees or more in order to sufficiently heat the preformed rubber G2. On the other hand, if the temperature of the warm air becomes high, the preformed rubber G2 may be heated excessively, and scorching of the rubber may occur. Therefore, the temperature of the warm air is preferably 130 ℃ or lower. The volume of the warm air is appropriately determined according to the rubber material and the shape of the preformed rubber G2.

Fig. 2 is a side view of the manufacturing apparatus 1 according to another embodiment. As shown in fig. 2, the manufacturing apparatus 1 shown in fig. 1 is included as it is in this embodiment. Description about the structure shown in fig. 1 is omitted. In this embodiment, the surrounding portion 20 surrounding the preformed rubber G2 between the form 9 and the rolling device 3 is provided. The outlet 12 of the air guide duct 4b is provided inside the surrounding portion 20. Such a surrounding portion 20 can efficiently transmit the heat of the warm air from the heater 4 to the entire preformed rubber G2, and therefore can further suppress the occurrence of shrinkage. The enclosing section 20 of the present embodiment is configured to have a side surface section 20a extending from the die plate 9 to the rolling device 3 side, and an end surface section 20b extending from the end of the side surface section 20a to the preformed rubber G2 side.

While the above description has been made of the particularly preferred embodiments of the present invention, the present invention is not limited to the illustrated embodiments,

the present invention can be modified into various embodiments.

Examples

Using the manufacturing apparatus shown in fig. 1, rubber strips after restarting the operation of the gear pump were manufactured in a trial manner based on the specifications of table 1, and the state of each rubber strip was tested. The common specification and test method of the rubber strip are as follows.

Thickness of preformed rubber: 3.0mm

Target thickness of rubber strip: 1.0mm

Temperature of warm air: measured at 10mm from the front end of the air outlet

Thickness of rubber strip and presence or absence of rubber scorching

The thickness (maximum thickness) of the rubber strip after the operation of the gear pump was reopened was measured, and scorching of the rubber strip was determined by the tester.

The results of the tests are shown in table 1.

[ TABLE 1 ]

The results of the tests confirmed that the rubber strip of the example was good compared with the rubber strip of the comparative example, having a thickness close to the target thickness. It was confirmed that the rubber strip of the comparative example and the rubber strip of the example in which the temperature of the warm air was low were hardened when the gear pump was stopped, and therefore, even when the rubber strip was rolled to a target thickness by the rolling device, the rubber strip could not be elastically deformed to the target thickness. In addition, it was confirmed that the rubber strip to which the warm air of a relatively high temperature was blown was scorched.

Claims

1. A method for manufacturing a rubber strip, which is a strip-shaped rubber strip made of unvulcanized rubber, is characterized by comprising:

an extrusion step of extruding the charged rubber as a preformed rubber after preliminary molding; and

a rolling step of rolling the preformed rubber and forming the rubber strip;

the operation and the stop of the extrusion process are alternately carried out,

the extrusion step includes a rest state in which extrusion of the preformed rubber is temporarily stopped, and,

in the idle state, the preformed rubber is heated by hot air at 60 to 130 ℃ in order to suppress a temperature decrease of the preformed rubber before the rolling step.

2. The method for manufacturing a rubber strip according to claim 1, wherein a manufacturing apparatus is used, the apparatus comprising:

a rubber extrusion device for preforming the charged rubber and extruding a preformed rubber, the rubber extrusion device having an extrusion port;

a rolling device that shapes the rubber strip by rolling the preformed rubber; and

and the warming machine is used for warming the preformed rubber between the extrusion port and the calendering device.

3. The method of manufacturing a rubber strip according to claim 2,

the warming machine includes a warm air blowing device that blows warm air to the preformed rubber.

4. The method of manufacturing a rubber strip according to claim 2 or 3,

the rubber extrusion device is provided with a gear pump for extruding rubber to the extrusion port,

the gear pump alternately operates and stops,

the warming machine warms the preformed rubber only when the gear pump is stopped.