阅读说明：本技术 橡胶挤出机以及橡胶挤出方法 (Rubber extruder and rubber extrusion method ) 是由 儿岛良治 河村幸伸 本田慎一郎 于 2020-02-07 设计创作，主要内容包括：提供橡胶挤出机以及橡胶挤出方法,能够兼具高粘度的未硫化橡胶的品质和生产率。该橡胶挤出机(1)包含：筒体(2)；投入部(3),其用于将未硫化橡胶(G)投入到筒体(2)的内部；以及螺杆(5),其用于向挤出方向(A)挤出被投入到筒体(2)的内部的未硫化橡胶(G)。在筒体(2)内设置有：截断部(6),其用于将未硫化橡胶(G)截断；搅拌部(7),其用于使被截断的未硫化橡胶(G)局部地搅入；以及加压部(8),其用于朝向挤出方向(A)对被搅入的未硫化橡胶(G)进行加压。加压部(8)构成为使螺杆(5)的螺纹(5b)间的空间容积朝向未硫化橡胶(G)的挤出方向(A)逐渐减小。(Provided are a rubber extruder and a rubber extrusion method, which can combine the quality and productivity of unvulcanized rubber having a high viscosity. The rubber extruder (1) comprises: a cylinder (2); an input unit (3) for inputting unvulcanized rubber (G) into the interior of the cylinder (2); and a screw (5) for extruding the unvulcanized rubber (G) injected into the cylinder (2) in the extrusion direction (A). The cylinder (2) is provided with: a cutting section (6) for cutting the unvulcanized rubber (G); a stirring section (7) for locally stirring in the cut unvulcanized rubber (G); and a pressurizing section (8) for pressurizing the kneaded unvulcanized rubber (G) in the extrusion direction (A). The pressurizing section (8) is configured such that the volume of the space between the flights (5b) of the screw (5) is gradually reduced toward the extrusion direction (A) of the unvulcanized rubber (G).)

1. A rubber extruder in which, in a rubber extruder,

the rubber extruder comprises: a barrel; a charging section for charging unvulcanized rubber into the cylinder; and a screw for extruding the unvulcanized rubber charged into the cylinder in an extrusion direction,

the barrel is internally provided with: a cutting section for cutting the unvulcanized rubber; a stirring section for locally stirring in the cut unvulcanized rubber; and a pressurizing section for pressurizing the kneaded unvulcanized rubber toward the extruding direction,

the pressurization part is configured to gradually decrease a volume of a space between the flights of the screw in the extrusion direction of the unvulcanized rubber.

2. The rubber extruder of claim 1,

the axial length of the pressing portion is greater than the axial length of the cut-off portion.

3. A rubber extruder in which, in a rubber extruder,

the rubber extruder comprises: a barrel; a charging section for charging unvulcanized rubber into the cylinder; and a screw for extruding the unvulcanized rubber charged into the cylinder in an extrusion direction,

the barrel is internally provided with: a cutting section for cutting the unvulcanized rubber; a stirring section for locally stirring in the cut unvulcanized rubber; and a pressing section that presses the kneaded unvulcanized rubber toward the extruding direction,

the cut-off part comprises a plurality of pin parts arranged on the cylinder body.

4. The rubber extruder of claim 3,

the plurality of pin portions are provided at least three positions in an axial direction of the cylinder,

the pitch of the pin portion in the axial direction is smaller on the stirring portion side than on the input portion side.

5. The rubber extruder according to claim 3 or 4,

the stirring section and the pressurizing section are not provided with pins.

6. A rubber extruder in which, in a rubber extruder,

the rubber extruder comprises: a barrel; a charging section for charging unvulcanized rubber into the cylinder; and a screw for extruding the unvulcanized rubber charged into the cylinder in an extrusion direction,

the barrel is internally provided with: a cutting section for cutting the unvulcanized rubber; a stirring section for locally stirring in the cut unvulcanized rubber; and a pressurizing section for pressurizing the kneaded unvulcanized rubber toward the extruding direction,

the input portion is provided with a biting portion for biting the unvulcanized rubber into the screw.

7. The rubber extruder of claim 6,

the input part comprises an input port arranged above the cylinder body,

the engaging portion includes a gear mechanism provided at the inlet.

8. The rubber extruder according to claim 6 or 7,

the bite portion includes a spreading mechanism for increasing a pitch length of the screw thread of the screw.

9. The rubber extruder according to any one of claims 6 to 8,

the bite portion includes a low-high mechanism that locally reduces the height of the thread of the screw.

10. The rubber extruder according to any one of claims 1 to 9,

the pressurization part is configured such that the depth of the screw thread of the screw gradually decreases toward the extrusion direction of the unvulcanized rubber.

11. The rubber extruder according to any one of claims 1 to 10,

the pressurization section is configured such that a pitch length of a screw thread of the screw is gradually reduced toward the extrusion direction of the unvulcanized rubber.

12. The rubber extruder according to any one of claims 1 to 11,

the stirring section includes a barrier extending between the flights of the screw.

13. The rubber extruder according to any one of claims 1 to 12,

the stirring section includes a cylindrical bank section provided concentrically with the screw.

14. The rubber extruder according to any one of claims 1 to 13,

the unvulcanized rubber charged has a Mooney viscosity ML1+4 of 90 or more at 100 ℃.

15. A method of extruding a rubber, wherein,

the rubber extrusion method comprises the following steps:

a charging step of charging unvulcanized rubber into the interior of a cylinder of a rubber extruder; and

an extrusion step of extruding the unvulcanized rubber charged into the cylinder in an extrusion direction by a screw,

the extrusion step includes the following steps: cutting the unvulcanized rubber; a step of locally stirring in the cut unvulcanized rubber; and a step of pressurizing the kneaded unvulcanized rubber in the extrusion direction,

the pressurizing step is configured to pressurize the unvulcanized rubber by gradually decreasing a volume of a space between flights of the screw in the extrusion direction of the unvulcanized rubber.

16. A method of extruding a rubber, wherein,

the rubber extrusion method comprises the following steps:

a charging step of charging unvulcanized rubber into the interior of a cylinder of a rubber extruder; and

an extrusion step of extruding the unvulcanized rubber charged into the cylinder in an extrusion direction by a screw,

the extrusion step includes the following steps: cutting the unvulcanized rubber; a step of locally stirring in the cut unvulcanized rubber; and a step of pressurizing the kneaded unvulcanized rubber in the extrusion direction,

the cutting step cuts the unvulcanized rubber by a plurality of pin portions provided on the cylindrical body.

17. A method of extruding a rubber, wherein,

the rubber extrusion method comprises the following steps:

a charging step of charging unvulcanized rubber into the interior of a cylinder of a rubber extruder; and

an extrusion step of extruding the unvulcanized rubber charged into the cylinder in an extrusion direction by a screw,

the extrusion step includes the following steps: cutting the unvulcanized rubber; a step of locally stirring in the cut unvulcanized rubber; and a step of pressurizing the kneaded unvulcanized rubber in the extrusion direction,

the charging step is to charge the unvulcanized rubber through a nip portion of the rubber extruder.

Technical Field

The present invention relates to a rubber extruder and a rubber extrusion method for extruding unvulcanized rubber.

Background

Conventionally, a rubber extruder including a cylinder and a screw disposed inside the cylinder is known. For example, patent document 1 listed below proposes a rubber component manufacturing apparatus that can suppress a reduction in the quality of a low heat generating rubber component by providing a stopper region in the middle of a screw shaft.

Patent document 1: japanese laid-open patent publication (JP 2015-013414)

However, in the apparatus for producing a rubber member of patent document 1, when unvulcanized rubber having a high viscosity is extrusion-molded, productivity may be lowered, and further improvement is desired.

Disclosure of Invention

The present invention has been made in view of the above circumstances, and a main object thereof is to provide a rubber extruder capable of achieving both the quality and productivity of high-viscosity unvulcanized rubber.

The invention is a rubber extruder, characterized in that the rubber extruder comprises: a barrel; a charging section for charging unvulcanized rubber into the cylinder; and a screw for extruding the unvulcanized rubber charged into the cylinder in an extrusion direction, wherein: a cutting section for cutting the unvulcanized rubber; a stirring section for locally stirring in the cut unvulcanized rubber; and a pressurizing section configured to pressurize the kneaded unvulcanized rubber toward the extrusion direction, wherein a volume of a space between flights of the screw is gradually reduced toward the extrusion direction of the unvulcanized rubber.

In the rubber extruder of the present invention, it is preferable that the length of the pressing portion in the axial direction is longer than the length of the cutout portion in the axial direction.

The invention is a rubber extruder, characterized in that the rubber extruder comprises: a barrel; a charging section for charging unvulcanized rubber into the cylinder; and a screw for extruding the unvulcanized rubber charged into the cylinder in an extrusion direction, wherein: a cutting section for cutting the unvulcanized rubber; a stirring section for locally stirring in the cut unvulcanized rubber; and a pressing section that presses the kneaded unvulcanized rubber in the extrusion direction, wherein the cutting section includes a plurality of pins provided on the cylinder.

In the rubber extruder according to the present invention, it is preferable that the plurality of pin portions are provided at least three positions in the axial direction of the cylinder, and a pitch of the pin portions in the axial direction is smaller on the stirring portion side than on the input portion side.

In the rubber extruder of the present invention, it is preferable that no pin portion is provided in the stirring portion and the pressing portion.

The invention is a rubber extruder, characterized in that the rubber extruder comprises: a barrel; a charging section for charging unvulcanized rubber into the cylinder; and a screw for extruding the unvulcanized rubber charged into the cylinder in an extrusion direction, wherein: a cutting section for cutting the unvulcanized rubber; a stirring section for locally stirring in the cut unvulcanized rubber; and a pressurizing section for pressurizing the kneaded unvulcanized rubber in the extrusion direction, wherein the feeding section is provided with a biting section for biting the unvulcanized rubber into the screw.

In the rubber extruder of the present invention, it is preferable that the input portion includes an input port provided above the cylinder, and the engagement portion includes a gear mechanism provided at the input port.

In the rubber extruder of the present invention, it is preferable that the bite portion includes a widening mechanism for increasing a pitch length of the screw thread of the screw.

In the rubber extruder of the present invention, it is preferable that the bite portion includes a low-height mechanism that locally reduces a height of a flight of the screw.

In the rubber extruder of the present invention, it is preferable that the pressure section is configured such that a depth of a flight of the screw is gradually reduced toward the extrusion direction of the unvulcanized rubber.

In the rubber extruder of the present invention, it is preferable that the pressurizing section is configured such that a pitch length of the screw thread of the screw is gradually reduced toward the extruding direction of the unvulcanized rubber.

In the rubber extruder of the present invention, preferably, the stirring section includes a barrier section extending between the flights of the screw.

In the rubber extruder of the present invention, it is preferable that the stirring section includes a cylindrical bank provided concentrically with the screw.

In the rubber extruder of the present invention, it is preferable that the mooney viscosity ML1+4(100 ℃) of the unvulcanized rubber to be charged is 90 or more.

The present invention is a rubber extrusion method, comprising the steps of: a charging step of charging unvulcanized rubber into the interior of a cylinder of a rubber extruder; and an extrusion step of extruding the unvulcanized rubber charged into the cylinder in an extrusion direction by a screw, the extrusion step including the steps of: cutting the unvulcanized rubber; a step of locally stirring in the cut unvulcanized rubber; and a step of pressurizing the kneaded unvulcanized rubber in the extrusion direction, wherein the pressurizing step is configured to pressurize the unvulcanized rubber by gradually decreasing a volume of a space between flights of the screw in the extrusion direction of the unvulcanized rubber.

The present invention is a rubber extrusion method, comprising the steps of: a charging step of charging unvulcanized rubber into the interior of a cylinder of a rubber extruder; and an extrusion step of extruding the unvulcanized rubber charged into the cylinder in an extrusion direction by a screw, the extrusion step including the steps of: cutting the unvulcanized rubber; a step of locally stirring in the cut unvulcanized rubber; and a step of pressing the kneaded unvulcanized rubber in the extrusion direction, wherein the cutting step cuts the unvulcanized rubber by a plurality of pins provided on the cylindrical body.

The present invention is a rubber extrusion method, comprising the steps of: a charging step of charging unvulcanized rubber into the interior of a cylinder of a rubber extruder; and an extrusion step of extruding the unvulcanized rubber charged into the cylinder in an extrusion direction by a screw, the extrusion step including the steps of: cutting the unvulcanized rubber; a step of locally stirring in the cut unvulcanized rubber; and a step of pressurizing the kneaded unvulcanized rubber in the extrusion direction, wherein the step of feeding feeds the unvulcanized rubber through a nip portion of the rubber extruder.

The rubber extruder of the present invention comprises: a barrel; a charging section for charging unvulcanized rubber into the cylinder; and a screw for extruding the unvulcanized rubber charged into the cylinder in an extrusion direction, wherein: a cutting section for cutting the unvulcanized rubber; a stirring section for locally stirring in the cut unvulcanized rubber; and a pressurizing section for pressurizing the kneaded unvulcanized rubber toward the extruding direction.

Such a cut portion of the rubber extruder can improve the flowability of the unvulcanized rubber, promote the heat generation and plasticization of the unvulcanized rubber, and improve the productivity of extrusion molding. In addition, the stirring section of the rubber extruder can uniformly stir the unvulcanized rubber even when the amount of the unvulcanized rubber to be charged varies. In addition, the pressing portion of the rubber extruder can integrate the unvulcanized rubber without increasing the residual stress of the cut unvulcanized rubber. Therefore, the rubber extruder can stably extrude the homogeneously stirred unvulcanized rubber into a desired shape.

In the rubber extruder of the present invention, the pressurizing section is configured such that the volume of the space between the flights of the screw is gradually reduced toward the extrusion direction of the unvulcanized rubber. Such a pressurization part can integrate the unvulcanized rubber without increasing the residual stress of the cut unvulcanized rubber, and can improve the quality of the extruded unvulcanized rubber.

In the rubber extruder of the present invention, the cutting portion includes a plurality of pins provided on the cylinder. Such a cut-off portion can easily adjust the projection amount of the pin portion in accordance with the viscosity of the unvulcanized rubber, and can further improve the productivity of the extrusion molding.

In the rubber extruder of the present invention, the input portion is provided with a biting portion for biting the unvulcanized rubber into the screw. Such an input unit can reliably input unvulcanized rubber continuously input as a strip into the cylinder, and can reduce production loss due to an input failure of the unvulcanized rubber.

Therefore, the rubber extruder of the present invention can combine the quality and productivity of unvulcanized rubber having a high viscosity.

The rubber extrusion method of the present invention includes the steps of: a charging step of charging unvulcanized rubber into the interior of a cylinder of a rubber extruder; and an extrusion step of extruding the unvulcanized rubber charged into the cylinder in an extrusion direction by a screw, the extrusion step including the steps of: cutting the unvulcanized rubber; a step of locally stirring in the cut unvulcanized rubber; and a step of pressurizing the kneaded unvulcanized rubber in the extrusion direction.

The step of cutting in such a rubber extrusion method can improve the flowability of the unvulcanized rubber, promote the heat generation and plasticization of the unvulcanized rubber, and improve the productivity of extrusion molding. In the step of kneading in the rubber extrusion method, the unvulcanized rubber can be homogeneously kneaded even when the amount of the unvulcanized rubber to be charged varies. In addition, the step of pressurizing in the rubber extrusion method can integrate the unvulcanized rubber G without increasing the residual stress of the cut unvulcanized rubber G. Therefore, the rubber extrusion method can stably extrude the homogeneously stirred unvulcanized rubber into a desired shape.

In the rubber extrusion method of the present invention, the pressurizing step is configured to pressurize the unvulcanized rubber by gradually decreasing the volume of the space between the flights of the screw in the extrusion direction of the unvulcanized rubber. The step of applying pressure as described above can integrate the unvulcanized rubber without increasing the residual stress of the unvulcanized rubber, and can improve the quality of the extruded unvulcanized rubber.

In the rubber extrusion method of the present invention, the step of cutting cuts the unvulcanized rubber by the plurality of pin portions provided in the cylindrical body. In such a cutting step, the projection amount of the pin portion can be easily adjusted according to the viscosity of the unvulcanized rubber, and the productivity of the extrusion molding can be further improved.

In the rubber extrusion method of the present invention, the charging step charges the unvulcanized rubber through a nip portion of the rubber extruder. In this charging step, the unvulcanized rubber continuously charged as the strip can be reliably charged into the cylinder, and the production loss due to the charging failure of the unvulcanized rubber can be reduced.

Therefore, the rubber extrusion method of the present invention can combine the quality and productivity of the unvulcanized rubber having a high viscosity.

Drawings

Fig. 1 is a sectional view showing one embodiment of a rubber extruder of the present invention.

FIG. 2 is a flow chart showing one embodiment of the rubber extrusion method of the present invention.

Fig. 3 is a flow chart of an extrusion process.

Fig. 4 is a sectional view showing a rubber extruder of embodiment 2.

Fig. 5 is a sectional view showing a rubber extruder of embodiment 3.

Fig. 6 is a sectional view showing a rubber extruder of embodiment 4.

Fig. 7 is a sectional view showing a rubber extruder of embodiment 5.

Fig. 8 is a sectional view showing a rubber extruder of embodiment 6.

Description of the reference symbols

1: a rubber extruder; 2: a barrel; 3: a charging section; 5: a screw; 6: a cut-off portion; 6 a: a pin portion; 7: a stirring section; 8: and a pressurization part.

Detailed Description

Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings.

Fig. 1 is a sectional view showing a rubber extruder 1 of the present embodiment. As shown in fig. 1, a rubber extruder 1 of the present embodiment includes: a cylinder body 2; an input unit 3 for inputting unvulcanized rubber G into the cylinder 2; and a discharge unit 4 that discharges the unvulcanized rubber G inside the cylinder 2. The rubber extruder 1 preferably includes a screw 5, and the screw 5 is used for extruding the unvulcanized rubber G injected into the cylinder 2 in an extrusion direction a from the injection portion 3 side toward the discharge portion 4 side.

The cylindrical body 2 of the present embodiment is provided with: a cutting section 6 for cutting the unvulcanized rubber G; a stirring section 7 for locally stirring in the unvulcanized rubber G cut by the cutting section 6; and a pressurizing section 8 for pressurizing the unvulcanized rubber G kneaded by the kneading section 7 in the extrusion direction a.

Here, "cutting the unvulcanized rubber G" means at least partially subdividing the unvulcanized rubber G which is introduced as a continuous strip. Further, "stirring the unvulcanized rubber G locally" means that the unvulcanized rubber G is stirred more strongly than the stirring by the cylinder 2 and the screw 5 by passing the unvulcanized rubber G through a locally narrow region.

The pressurizing section 8 can pressurize the unvulcanized rubber G so that the pressure gradually increases linearly, for example. The pressurizing portion 8 may increase the pressure of the unvulcanized rubber G in a stepwise manner by dividing the pressure of the unvulcanized rubber G into a plurality of stages, or may increase the pressure of the unvulcanized rubber G in a quadratic manner. In this way, the pressurizing portion 8 preferably gradually pressurizes the unvulcanized rubber G toward the extrusion direction a. The pressurizing section 8 may pressurize the unvulcanized rubber G at a rate of increase per unit time of the pressure of 0.1MPa/s or less, for example.

The cut portion 6 of the rubber extruder 1 can improve the flowability of the unvulcanized rubber G, promote the heat generation and plasticization of the unvulcanized rubber G, and improve the productivity of extrusion molding. The stirring section 7 of the rubber extruder 1 can stir the unvulcanized rubber G homogeneously even when the amount of the unvulcanized rubber G to be charged varies. Further, the pressing section 8 of the rubber extruder 1 can integrate the unvulcanized rubber G without increasing the residual stress of the cut unvulcanized rubber G. Therefore, the rubber extruder 1 of the present embodiment can stably extrude the homogeneously stirred unvulcanized rubber G into a desired shape.

More preferably, the unvulcanized rubber G to be charged is a high-viscosity unvulcanized rubber G having a Mooney viscosity ML1+4(100 ℃ C.) of 90 or more. The unvulcanized rubber G preferably contains at least a rubber component, silica and a silane coupling agent. Such an unvulcanized rubber G can suppress heat generation associated with deformation, and can improve fuel efficiency when used for a tire.

The rubber component is not particularly limited, and examples thereof include diene rubber, butyl rubber (IIR), Natural Rubber (NR), and the like. Examples of the diene rubber include styrene-butadiene rubber (SBR), Butadiene Rubber (BR), isoprene rubber (IP), ethylene-propylene-diene rubber (EPDM), Chloroprene Rubber (CR), and acrylonitrile-butadiene rubber (NBR). Styrene-butadiene rubber (SBR) includes, for example, a multipolymer composed of styrene-butadiene and a non-conjugated olefin, in addition to terminal-modified S-SBR, main chain-modified S-SBR, and hydrogenated SBR. The rubber component may be used alone or in combination of two or more.

As the silicon oxide, silicon oxide conventionally used in this technical field can be used without particular limitation. Examples of the silicon oxide include dry-process silicon oxide (anhydrous silicon oxide), wet-process silicon oxide (hydrous silicon oxide), and the like.

The silane coupling agent is not particularly limited, and examples thereof include thioether-based, mercapto-based, vinyl-based, amino-based, glycidoxy-based, nitro-based, and chlorine-based silane coupling agents. The silane coupling agent may be used alone or in combination of two or more.

The unvulcanized rubber G may contain, for example, carbon black, a filler, and the like in addition to the rubber component, silica, and a silane coupling agent.

The carbon black is not particularly limited, and known carbon black compounded to unvulcanized rubber G can be used. Examples of the carbon black include SAF, ISAF, HAF, FEF, GPF, and the like which are generally used in the art. One kind of carbon black may be used alone, or two or more kinds may be used in combination.

The filler is not particularly limited, and may include any of an organic filler and an inorganic filler. Examples of the filler include calcium carbonate, mica, aluminum hydroxide, magnesium oxide, clay, talc, titanium oxide, carbon fiber, cellulose fiber, carbon nanotube (multilayer, single-layer), graphene, and the like.

The unvulcanized rubber G may be compounded with compounding agents conventionally used in the art in addition to the above components. Examples of the compounding agent include zinc oxide, thermoplastic polyurethane, stearic acid, age resistor, oil, and wax.

The cylinder 2 is preferably formed in a hollow substantially cylindrical shape concentrically provided with the screw 5. The cylinder 2 is provided with, for example, an input portion 3 on one side in the axial direction and a discharge portion 4 on the other side. The temperature of the cylindrical body 2 of the present embodiment is adjusted to 120 ℃. Such a cylindrical body 2 can suppress the occurrence of residual stress in the unvulcanized rubber G inside, and can improve the quality of the unvulcanized rubber G.

The input portion 3 includes, for example, an input port 2a provided in the cylindrical body 2. The input portion 3 is preferably provided with a biting portion 9 for allowing the unvulcanized rubber G to bite into the screw 5. Such an input unit 3 can reliably input the unvulcanized rubber G, which is continuously input as a strip, into the cylinder 2, and can reduce production loss due to a failure in inputting the unvulcanized rubber G.

The engaging portion 9 includes, for example, a gear mechanism 9A provided at the inlet 2 a. The gear mechanism 9A preferably rotates the pair of gears in synchronization by a drive source (not shown). The gear mechanism 9A may be provided, for example, near the outer shape of the cylindrical body 2, or may be provided at two positions, i.e., near the outer shape of the cylindrical body 2 and at an intermediate position of the inlet 2 a. Even at the initial stage of charging the unvulcanized rubber G or when the charging of the unvulcanized rubber G is interrupted, the biting portion 9 can feed the unvulcanized rubber G toward the screw 5, and can forcibly charge the unvulcanized rubber G continuously charged as a strip into the inside of the cylinder 2.

The discharge portion 4 is not particularly limited, and a discharge portion conventionally used in the art may be used. Although not shown, the discharge portion 4 may be coupled to a head portion provided with a gear pump, a mold, or the like, for example.

Preferably, the screw 5 includes a screw shaft 5a and a flight 5b extending spirally around the screw shaft 5 a. The pitch length P of the flight 5b of the present embodiment is substantially the same over the entire flight length of the screw 5. The screw 5 is configured to be rotationally driven by a driving portion M provided at an end portion on the side of the input portion 3 so as to freely change a rotational speed, for example. Since the rotation speed of the screw 5 can be adjusted according to the viscosity of the unvulcanized rubber G, the quality of the unvulcanized rubber G can be maintained.

The cut-off portion 6 of the present embodiment includes a plurality of pin portions 6A provided on the cylindrical body 2. Such a cut-off portion 6 can easily adjust the projection amount of the pin portion 6A in accordance with the viscosity of the unvulcanized rubber G, and the productivity of extrusion molding can be further improved.

The plurality of pin portions 6A are provided at least two positions, for example, in the axial direction of the cylinder 2, and in the present embodiment, at three positions. The pin portion 6A of the present embodiment has substantially the same pitch P1 in the axial direction. Although not shown, the plurality of pin portions 6A are provided at least two positions in the circumferential direction of the cylindrical body 2, and in the present embodiment, at three positions. The circumferential installation pitches of the pin portions 6A in the present embodiment are substantially the same. The plurality of pin portions 6A may be provided in a spiral shape on the cylindrical body 2, for example.

Each pin portion 6A is provided so that, for example, the amount of projection from the inner surface of the cylinder 2 can be freely adjusted. At a position of the screw 5 corresponding to the pin portion 6A, for example, a portion where the height H of the thread 5b is small or the thread 5b is partially lost is provided so as not to interfere with the pin portion 6A even when the projection amount is adjusted to the maximum. Here, "the height H of the flight 5 b" is 1/2 of the difference between the outer diameter of the flight 5b at that position and the diameter of the screw shaft 5a at that position. That is, the "height H of the flight 5 b" is the radial distance of the outer surface of the screw shaft 5a at this position from the outer surface of the flight 5 b.

The stirring section 7 includes, for example, at least one (one in the present embodiment) stopper 7A extending between the flights 5b of the screw 5. The stopper portion 7A may be provided in plural numbers in the axial direction, or may be provided in plural numbers in the circumferential direction, for example.

The stopper 7A of the present embodiment is provided at an angle with respect to the axial direction of the screw 5. The stopper 7A may be provided, for example, along the axial direction of the screw 5. Such a stopper 7A can cause unvulcanized rubber G to locally intrude into a narrow region between the stopper 7A and the cylinder 2 without reducing the discharge amount of the unvulcanized rubber G.

The pressurizing section 8 of the present embodiment is configured such that the volume of the space between the flights 5b of the screw 5 gradually decreases toward the extrusion direction a of the unvulcanized rubber G. For example, a plurality of the pressurizing portions 8 may be provided with a space having a constant volume between the threads 5b interposed therebetween. Such a pressurization part 8 can integrate the unvulcanized rubber G without increasing the residual stress of the cut unvulcanized rubber G, and can improve the quality of the extruded unvulcanized rubber G. Further, a portion for making the volume of the space between the flights 5b constant may be provided on the downstream side of the pressing portion 8 in the extrusion direction a, for example.

The pressurizing portion 8 is configured such that, for example, the depth D of the flight 5b of the screw 5 gradually decreases toward the extrusion direction a of the unvulcanized rubber G. Here, "the depth D of the flight 5 b" is 1/2 of the difference between the maximum outer diameter of the flight 5b and the diameter of the screw shaft 5a at that position. That is, the "depth D of the flight 5 b" is the radial distance of the outer surface of the screw shaft 5a at that position from the outer surface at the position of the maximum outer diameter of the flight 5 b.

In the pressurization part 8, the ratio (D2-D1)/L1 of the difference between the depth D1 at the start position of the pressurization part 8 and the depth D2 at the end position of the pressurization part 8 to the length L1 in the axial direction of the pressurization part 8 is preferably 1% to 5%. Such a pressurizing portion 8 can reduce the rate of increase per unit time of the pressure of the unvulcanized rubber G, and can integrate the unvulcanized rubber G without increasing the residual stress even when the discharge amount of the unvulcanized rubber G is increased.

The axial length L1 of the pressurization part 8 is preferably larger than the axial length L2 of the cutout part 6. The axial length L1 of the pressurizing portion 8 is preferably 10% or more of the screw length of the screw 5. Such a pressurizing portion 8 can reduce the rate of increase per unit time of the pressure of the unvulcanized rubber G, and can integrate the unvulcanized rubber G without increasing the residual stress even when the discharge amount of the unvulcanized rubber G is increased.

The pin portion 6A is not provided in the stirring portion 7 and the pressurizing portion 8 of the present embodiment. Therefore, the quality of the extruded unvulcanized rubber G can be improved without being cut by the stirring section 7 and the pressing section 8.

Next, a rubber extrusion method for extruding unvulcanized rubber G by using the rubber extruder 1 of the present embodiment will be described with reference to fig. 1.

Fig. 2 is a flowchart of the rubber extrusion method of the present embodiment. As shown in fig. 2, in the rubber extrusion method of the present embodiment, first, the charging step S1 is performed to charge the unvulcanized rubber G into the cylinder 2 of the rubber extruder 1. In the charging step S1, the unvulcanized rubber G is preferably charged through the nip portion 9 provided in the charging portion 3 of the rubber extruder 1. In the charging step S1, the unvulcanized rubber G continuously charged as a strip can be reliably charged into the cylinder 2, and the production loss due to the charging failure of the unvulcanized rubber G can be reduced.

In the charging step S1, the unvulcanized rubber G is charged through, for example, a gear mechanism 9A provided at the charging port 2a of the rubber extruder 1. Even in the case where the unvulcanized rubber G is fed into the feeding step S1 in the initial stage of feeding the unvulcanized rubber G or the feeding of the unvulcanized rubber G is interrupted, the unvulcanized rubber G can be fed toward the screw 5, and the unvulcanized rubber G continuously fed as a band can be forcibly fed into the cylinder 2.

In the rubber extrusion method of the present embodiment, the extrusion step S2 is performed after the charging step S1, and the unvulcanized rubber G charged into the cylinder 2 is extruded in the extrusion direction a by the screw 5. The details of the extrusion step S2 will be described later. In the rubber extrusion method, it is preferable to perform the discharging step S3 after the extrusion step S2. The discharge step S3 may be a step that is conventional in the art, and a detailed description thereof is omitted here.

Fig. 3 is a flowchart of the extrusion process S2. As shown in fig. 3, in the extrusion step S2 of the present embodiment, first, a step S21 of cutting the unvulcanized rubber G is performed. The step S21 of performing such a cutting can improve the flowability of the unvulcanized rubber G, promote the heat generation and plasticization of the unvulcanized rubber G, and improve the productivity of the extrusion molding.

In the cutting step S21, the unvulcanized rubber G is preferably cut by the plurality of pin portions 6A provided on the cylinder 2. The step S21 of performing such cutting can easily adjust the projection amount of the pin portion 6A according to the viscosity of the unvulcanized rubber G, and can further improve the productivity of the extrusion molding.

The extrusion step S2 of the present embodiment is a step S22 of partially stirring the cut unvulcanized rubber G after the step S21 of cutting. In the step S22 of stirring in this manner, even when the amount of the unvulcanized rubber G to be charged varies, the unvulcanized rubber G can be uniformly stirred.

In the kneading step S22, the unvulcanized rubber G is kneaded by, for example, the dam portion 7A extending between the flights 5b of the screw 5. In the step S22 of kneading, the unvulcanized rubber G can be locally kneaded into a narrow region between the stopper 7A and the cylinder 2 without reducing the discharge amount of the unvulcanized rubber G.

The extrusion step S2 of the present embodiment includes, after the step S22 of kneading, a step S23 of pressurizing the kneaded unvulcanized rubber G in the extrusion direction a. In the step S23 of pressurizing, the unvulcanized rubber G is preferably pressurized by gradually decreasing the volume of the space between the flights 5b of the screw 5 in the extrusion direction a of the unvulcanized rubber G. The step S23 of performing such pressurization can integrate the unvulcanized rubber G without increasing the residual stress of the unvulcanized rubber G. Therefore, the rubber extrusion method of the present embodiment can stably extrude the homogeneously stirred unvulcanized rubber G into a desired shape.

In the step S23 of pressurizing, the unvulcanized rubber G is pressurized by, for example, gradually decreasing the depth D of the flight 5b of the screw 5 in the extrusion direction a of the unvulcanized rubber G. In the step S23 of performing pressurization, the rate of increase per unit time of the pressure of the unvulcanized rubber G can be reduced, and the unvulcanized rubber G can be pressurized without increasing the residual stress of the unvulcanized rubber G.

Fig. 4 is a sectional view of the rubber extruder 11 of embodiment 2. The same reference numerals are given to constituent elements having the same functions as those of the above-described embodiment, and the description thereof will be omitted. As shown in fig. 4, the rubber extruder 11 according to embodiment 2 includes a cylinder 2, an input portion 3, a discharge portion 4, and a screw 5, as in the case of the rubber extruder 1. Further, the blocking portion 6, the stirring portion 7, and the pressurizing portion 8 are preferably provided in the cylindrical body 2.

The bite portion 9 provided in the input portion 3 of this embodiment includes, for example, a widening mechanism 9B for increasing the pitch length P of the thread 5B of the screw 5. The pitch length P2 of the thread 5B of the tenter mechanism 9B is preferably 110% to 150% of the pitch length P of the thread 5B in the portion other than the tenter mechanism 9B. Even in the initial stage of charging the unvulcanized rubber G or in the case where the charging of the unvulcanized rubber G is interrupted, the biting portion 9 can insert the unvulcanized rubber G between the threads 5b, and can reliably charge the unvulcanized rubber G continuously charged as a strip into the cylinder 2.

The stirring section 7 of this embodiment includes, for example, a cylindrical bank section 7B provided concentrically with the screw 5. Such a stirring section 7 can locally and strongly stir the entire unvulcanized rubber G passing through the bank section 7B into a narrow region between the bank section 7B and the cylindrical body 2. The bank portion 7B may be provided with a plurality of small holes (not shown) penetrating in the axial direction, for example.

It is preferable that an exhaust unit 10 for sucking air in the cylindrical body 2 is provided on the downstream side of the bank 7B in the extrusion direction a. The exhaust unit 10 includes, for example, a vacuum pump V. Such a vent part 10 can degas air and volatile components contained in the unvulcanized rubber G on the downstream side in the extrusion direction a of the bank part 7B, and can further improve the quality of the unvulcanized rubber G.

A rubber extrusion method for extruding unvulcanized rubber G using the rubber extruder 11 of embodiment 2 is shown in the flowcharts shown in fig. 2 and 3. That is, the rubber extrusion method of this embodiment includes the charging step S1, the extrusion step S2, and the discharging step S3. The extrusion step S2 preferably includes a step S21 of cutting, a step S22 of stirring, and a step S23 of pressing.

In the charging step S1 of this embodiment, for example, the unvulcanized rubber G is charged by the expanding mechanism 9B that increases the pitch length P of the flight 5B of the screw 5 of the rubber extruder 1. In the charging step S1, even at the initial stage of charging the unvulcanized rubber G or when the charged unvulcanized rubber G is interrupted, the unvulcanized rubber G can be inserted between the threads 5b, and the unvulcanized rubber G continuously charged as a strip can be reliably charged into the cylinder 2.

In the kneading step S22 of this embodiment, the unvulcanized rubber G is kneaded by the cylindrical bank 7B provided concentrically with the screw 5, for example. In the step S22 of performing such stirring, the whole unvulcanized rubber G passing through the bank 7B can be locally and strongly stirred into the narrow region between the bank 7B and the cylindrical body 2.

In the extrusion step S2 of this embodiment, a step (not shown) of degassing air and volatile components contained in the unvulcanized rubber G may be performed after the stirring-in step S22. Such an extrusion step S2 can further improve the quality of the unvulcanized rubber G.

Fig. 5 is a sectional view of the rubber extruder 21 of embodiment 3. The same reference numerals are given to constituent elements having the same functions as those of the above-described embodiment, and the description thereof will be omitted. As shown in fig. 5, the rubber extruder 21 according to embodiment 3 includes a cylinder 2, an input portion 3, a discharge portion 4, and a screw 5, as in the rubber extruders 1 and 11 described above. Further, the blocking portion 6, the stirring portion 7, and the pressurizing portion 8 are preferably provided in the cylindrical body 2.

The bite portion 9 provided in the input portion 3 of this embodiment includes, for example, a low-high mechanism 9C that partially reduces the height H of the flight 5b of the screw 5. The low-high mechanism 9C may be, for example, a portion where the thread 5b is partially missing. Even in the initial stage of charging the unvulcanized rubber G or in the case where the charging of the unvulcanized rubber G is interrupted, the biting portion 9 can cause the unvulcanized rubber G to enter the low-high mechanism 9C, and can reliably charge the unvulcanized rubber G continuously charged as a strip into the cylinder 2.

The cut-off portion 6 of this embodiment includes a plurality of pin portions 6A provided on the cylindrical body 2, similarly to the cut-off portion 6 described above. The pin portion 6A of this embodiment is provided at least three positions in the axial direction of the cylinder 2. The axial pitch of the pin portions 6A is preferably set to a pitch P3 on the stirring portion 7 side smaller than the pitch P4 on the input portion 3 side. Such a cutting portion 6 can cut the unvulcanized rubber G more finely on the downstream side in the extrusion direction a, and can further improve the flowability of the unvulcanized rubber G.

The stirring section 7 of this embodiment includes, for example, a bank section 7B and a dam section 7A. The dam portion 7A is preferably located on the downstream side of the bank portion 7B in the extrusion direction a. Such a stirring section 7 can stir the unvulcanized rubber G stirred in by the bank section 7B further by the stopper section 7A, and therefore can stir the unvulcanized rubber G more strongly.

In this embodiment, it is preferable to provide a gas discharge portion 10 for sucking air in the cylindrical body 2 between the bank portion 7B and the barrier portion 7A. Such a vent part 10 can efficiently degas air and volatile components contained in the unvulcanized rubber G between the bank part 7B and the barrier part 7A.

A rubber extrusion method for extruding unvulcanized rubber G using the rubber extruder 21 of embodiment 3 is shown in the flowcharts shown in fig. 2 and 3. That is, the rubber extrusion method of this embodiment includes the charging step S1, the extrusion step S2, and the discharging step S3. The extrusion step S2 preferably includes a step S21 of cutting, a step S22 of stirring, and a step S23 of pressing.

In the charging step S1 of the embodiment, the unvulcanized rubber G is charged by, for example, the low-high mechanism 9C that locally reduces the height H of the screw 5b of the rubber extruder 1. In the charging step S1, even at the initial stage of charging the unvulcanized rubber G or when the charging of the unvulcanized rubber G is interrupted, the unvulcanized rubber G can be introduced into the low-high mechanism 9C, and the unvulcanized rubber G continuously charged as a strip can be reliably charged into the cylinder 2.

In the cutting step S21 of the present embodiment, for example, the unvulcanized rubber G is cut by the plurality of pin portions 6A having the pitch P3 on the stirring portion 7 side smaller than the pitch P4 on the loading portion 3 side. In the step S21 of performing such cutting, the unvulcanized rubber G can be cut into smaller pieces on the downstream side in the extrusion direction a, and the productivity of the extrusion molding can be further improved.

In the kneading step S22 of this embodiment, the unvulcanized rubber G is kneaded by the bank portion 7B and the dam portion 7A provided in the screw 5, for example. In this embodiment, it is preferable to deaerate air and volatile components contained in the unvulcanized rubber G in the stirring-in step S22. In the step S22 of kneading, the unvulcanized rubber G can be kneaded more strongly, and the quality of the extruded unvulcanized rubber G can be further improved.

Fig. 6 is a sectional view of the rubber extruder 31 of embodiment 4. The same reference numerals are given to constituent elements having the same functions as those of the above-described embodiment, and the description thereof will be omitted. As shown in fig. 6, the rubber extruder 31 according to embodiment 4 includes a cylinder 2, an input portion 3, a discharge portion 4, and a screw 5, as in the case of the rubber extruder 1 and the like. Further, the blocking portion 6, the stirring portion 7, and the pressurizing portion 8 are preferably provided in the cylindrical body 2.

The biting portion 9 provided in the input portion 3 of the present embodiment includes, for example: a gear mechanism 9A provided at the inlet 2 a; a widening mechanism 9B for increasing the pitch length P of the thread 5B; and a low-high mechanism 9C that locally reduces the height H of the thread 5 b. The bite portion 9 may include two mechanisms of the gear mechanism 9A, the width expanding mechanism 9B, and the low-high mechanism 9C, for example. Such a biting portion 9 can be more reliably put into the cylinder 2 even with high-viscosity unvulcanized rubber G by the interaction of a plurality of mechanisms.

The cutting portion 6 of this embodiment is exemplified as a case where the plurality of pin portions 6A are provided at substantially the same pitch, but the cutting portion 6 may be provided at different pitches of the plurality of pin portions 6A, for example. Further, the stirring section 7 of this embodiment exemplifies the barrier section 7A, but the stirring section 7 may include, for example, a bank section 7B.

A rubber extrusion method for extruding unvulcanized rubber G using the rubber extruder 31 of embodiment 4 is shown in the flowcharts shown in fig. 2 and 3. That is, the rubber extrusion method of this embodiment includes the charging step S1, the extrusion step S2, and the discharging step S3. The extrusion step S2 preferably includes a step S21 of cutting, a step S22 of stirring, and a step S23 of pressing.

In the charging step S1 of the embodiment, the unvulcanized rubber G is charged through, for example, the gear mechanism 9A, the widening mechanism 9B, and the low-high mechanism 9C of the rubber extruder 1. In the charging step S1, even the unvulcanized rubber G having a high viscosity can be charged into the cylindrical body 2 more reliably by the interaction of the plurality of mechanisms.

Fig. 7 is a sectional view of a rubber extruder 41 of embodiment 5. The same reference numerals are given to constituent elements having the same functions as those of the above-described embodiment, and the description thereof will be omitted. As shown in fig. 7, the rubber extruder 41 according to embodiment 5 includes a cylinder 2, an input portion 3, a discharge portion 4, and a screw 5, as in the case of the rubber extruder 1 and the like. Further, the blocking portion 6, the stirring portion 7, and the pressurizing portion 8 are preferably provided in the cylindrical body 2. In the screw 5 of this embodiment, for example, the diameter of the screw shaft 5a is made substantially the same over the entire length of the flight of the screw 5.

The gear mechanism 9A is illustrated as the engaging portion 9 of the input portion 3 in this embodiment, but the engaging portion 9 may include at least one of the widening mechanism 9B and the low-high mechanism 9C, for example. The cutting portion 6 of this embodiment is exemplified as a case where the plurality of pin portions 6A are provided at substantially the same pitch, but the cutting portion 6 may be provided at different pitches of the plurality of pin portions 6A, for example. Further, the stirring section 7 of this embodiment exemplifies the barrier section 7A, but the stirring section 7 may include, for example, a bank section 7B.

The pressing section 8 of this embodiment is configured such that, for example, the pitch length P of the flight 5b of the screw 5 gradually decreases toward the extrusion direction a of the unvulcanized rubber G. For the pressurization section 8, the ratio (P5-P6)/L1 of the difference between the pitch length P5 at the start position of the pressurization section 8 and the pitch length P6 at the end position of the pressurization section 8 to the length L1 in the axial direction of the pressurization section 8 is preferably 3% to 8%. Such a pressurization section 8 can reduce the rate of increase per unit time of the pressure of the unvulcanized rubber G, and can integrate the unvulcanized rubber G without increasing the residual stress of the unvulcanized rubber G.

A rubber extrusion method for extruding unvulcanized rubber G using the rubber extruder 41 of embodiment 5 is shown in the flowcharts shown in fig. 2 and 3. That is, the rubber extrusion method of this embodiment includes the charging step S1, the extrusion step S2, and the discharging step S3. The extrusion step S2 preferably includes a step S21 of cutting, a step S22 of stirring, and a step S23 of pressing.

In the pressurizing step S23 of the present embodiment, the unvulcanized rubber G is pressurized by, for example, gradually decreasing the pitch length P of the flight 5b of the screw 5 in the extrusion direction a of the unvulcanized rubber G. In the step S23 of performing pressurization, the rate of increase per unit time of the pressure of the unvulcanized rubber G can be reduced, and the unvulcanized rubber G can be pressurized without increasing the residual stress of the unvulcanized rubber G.

Fig. 8 is a sectional view of a rubber extruder 51 of embodiment 6. The same reference numerals are given to constituent elements having the same functions as those of the above-described embodiment, and the description thereof will be omitted. As shown in fig. 8, the rubber extruder 51 according to embodiment 6 includes a cylinder 2, an input portion 3, a discharge portion 4, and a screw 5, as in the case of the rubber extruder 1 and the like. Further, the blocking portion 6, the stirring portion 7, and the pressurizing portion 8 are preferably provided in the cylindrical body 2.

The gear mechanism 9A and the low-high mechanism 9C are illustrated as the engaging portion 9 of the input portion 3 in this embodiment, but the engaging portion 9 may include at least one of the above-described mechanisms. The cutting section 6 of the present embodiment illustrates a case where the pitch P3 on the stirring section 7 side is smaller than the pitch P4 on the input section 3 side, but the cutting section 6 may be provided with substantially the same pitch of the plurality of pin sections 6A, for example. Further, the stirring section 7 of this embodiment exemplifies the barrier section 7A, but the stirring section 7 may include, for example, a bank section 7B.

The pressing portion 8 of this embodiment is configured such that the depth D of the flight 5b of the screw 5 gradually decreases toward the extrusion direction a of the unvulcanized rubber G and the pitch length P of the flight 5b of the screw 5 gradually decreases toward the extrusion direction a of the unvulcanized rubber G. Such a pressurizing portion 8 can appropriately increase the pressure of the unvulcanized rubber G, and can efficiently integrate the unvulcanized rubber G.

A rubber extrusion method for extruding unvulcanized rubber G using the rubber extruder 51 of embodiment 6 is shown in the flowcharts shown in fig. 2 and 3. That is, the rubber extrusion method of this embodiment includes the charging step S1, the extrusion step S2, and the discharging step S3. The extrusion step S2 preferably includes a step S21 of cutting, a step S22 of stirring, and a step S23 of pressing.

In the pressurizing step S23 of the present embodiment, the unvulcanized rubber G is pressurized by, for example, gradually decreasing the depth D and the pitch length P of the flight 5b of the screw 5 in the extrusion direction a of the unvulcanized rubber G. In the step S23 of performing pressurization, the pressure of the unvulcanized rubber G can be appropriately increased, and the unvulcanized rubber G can be efficiently integrated.

While the above description has been made in detail with respect to the particularly preferred embodiments of the present invention, the present invention is not limited to the above embodiments, and may be modified into various embodiments.