JP2004142383A - Vacuum extruder for rubber - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vacuum extruder for rubber, which can optimally maintain the amount of clearance in a compression part even if a screw is not replaced. <P>SOLUTION: This vacuum extruder for the rubber is equipped with a cylinder 10, a screw 11 which is provided in the cylinder 10, the compression part 15 which is set so as to narrow the clearance between the screw 11 and an inner wall surface of the cylinder 10, and a vacuum chamber which is arranged on a rubber-extrusion downstream side with respect to the compression part 15. In the compression part 15, a spacer ring 16 for adjusting the amount of the clearance between the screw 11 and the inner wall surface of the cylinder 10 is detachably constituted. The cylinder 10 is split into two parts, that is, first and second cylinder parts 10a and 10b before and behind the compression part 15, and the spacer ring 16 is split into two halves, so that replacement work can be facilitated. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a cylinder, a screw provided in the cylinder, a compression unit set so that a gap between the screw and the inner wall surface of the cylinder is narrowed, and a vacuum disposed downstream of the rubber extrusion from the compression unit. The present invention relates to a vacuum extruder for rubber provided with a chamber.
[0002]
[Prior art]
The structure of such a vacuum extruder is shown in the schematic diagram of FIG. A cylinder 1 extending in the front-rear direction and a screw 2 also extending in the front-rear direction are provided inside the cylinder 1, and are rotationally driven by a drive mechanism (not shown). A hopper 3 is provided at the base of the screw 2, from which a rubber material is charged. The injected rubber material is extruded forward while being compressed and kneaded between the screw 2 and the inner wall surface of the cylinder. A die (not shown) is provided at the tip of the screw 2, and a rubber molded product having a predetermined sectional shape is extruded.
[0003]
A suction port 4 is provided at an intermediate position of the screw 2 in the front-rear direction. A vacuum pump is connected to the suction port 4 to form a vacuum chamber inside the cylinder 1. By applying a vacuum, gas generated from air, moisture, and compounding chemicals contained in the rubber material and vaporized moisture can be discharged to the outside. In order to enhance this discharge effect, it is necessary to reduce the thickness of the rubber material passing therethrough. Therefore, the compression section 5 is provided, and the gap δ between the outer surface of the screw 2 and the inner wall surface of the cylinder is set to be small. Therefore, in the compression section 5, the large diameter section 2a is formed in the screw 2. As a result, the rubber material that has passed through the compression section 5 becomes a thin sheet. Further, the downstream side of the compression section 5 constitutes a vacuum chamber.
[0004]
[Problems to be solved by the invention]
The problems in the above configuration are as follows. That is, depending on how the clearance between the inner wall surface of the cylinder and the outer surface of the screw is determined, the effect of discharging gas, moisture, and the like changes, which affects the quality of the rubber product. Therefore, a plurality of screws having different clearance amounts must be prepared. Further, if the composition or type of rubber is changed, physical properties such as viscosity change, so that it is necessary to change the setting of the gap amount. Also, if the vacuum extruder continues to operate, the compression section gradually wears out, so that the optimal gap amount cannot be maintained.
[0005]
In the above case, the gap amount is optimized by replacing the screw, but the replacement of the screw is troublesome, and it is necessary to prepare several screws, and the management is complicated. Was.
[0006]
The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a vacuum extruder for rubber capable of optimally maintaining a gap amount in a compression section without replacing screws.
[Means for Solving the Problems]
In order to solve the above problems, a rubber vacuum extruder according to the present invention,
A cylinder, a screw provided in the cylinder, a compression unit set so that a gap between the screw and the inner wall surface of the cylinder is narrowed, and a vacuum chamber arranged downstream of the rubber extruder from the compression unit. Rubber extruder,
In the compression section, a gap adjusting member for adjusting the amount of the gap between the screw and the inner wall surface of the cylinder is detachably configured.
[0007]
According to this configuration, the gap adjusting member is configured to be detachable in the compression section. When it is desired to change the gap amount, the currently mounted gap adjustment member may be removed and another gap adjustment member may be mounted. That is, there is no need to remove the screw. As a result, it is possible to provide a vacuum extruder for rubber that can optimally maintain the gap amount in the compression section without replacing the screw.
[0008]
As a preferred embodiment of the present invention, the gap adjusting member may be a ring-shaped member fitted to the inner wall surface of the cylinder or the outer surface of the screw.
[0009]
If the gap adjustment member is configured as a ring-shaped member, multiple ring-shaped members with different dimensions of the inner diameter (when mounted on the inner wall surface of the cylinder) or the outer diameter (when mounted on the outer surface of the screw) are prepared. You should keep it. The ring-shaped member can be considerably smaller in size than the screw and is easier to manage. In addition, since it has a ring shape, manufacture is easy.
[0010]
As another preferred embodiment of the present invention, the ring-shaped member is constituted by a plurality of members divided in a circumferential direction.
By dividing the ring-shaped member in the circumferential direction, the attachment / detachment work of the ring-shaped member can be easily performed.
[0011]
As still another preferred embodiment of the present invention, the cylinder is configured to be divided into a first cylinder portion and a second cylinder portion in a front-rear direction of the compression portion, and when attaching and detaching a gap adjusting member, One configured to expose the compression section may be mentioned.
[0012]
If the cylinder is divided into first and second cylinder portions in the front-rear direction, and one or both of the first and second cylinders are moved in the front-rear direction, the compression portion can be exposed. In this state, the gap adjusting member can be detached. The amount by which the first and second cylinders are moved may be an amount necessary for performing the attaching / detaching operation, which is a simple operation as compared with the operation of exchanging screws.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
A preferred embodiment of a vacuum extruder for rubber according to the present invention will be described with reference to the drawings. FIG. 1 is a schematic diagram showing a configuration of a vacuum extruder. FIG. 2 is an enlarged view of a main part.
[0014]
<Configuration of the embodiment>
A cylinder 10 is provided along the front-rear direction, and a screw 11 is also provided inside the cylinder 10 along the front-rear direction. The rubber material moves from the right side to the left side in FIG. A drive mechanism 12 is provided on the root side of the screw 11. The drive mechanism 12 includes a motor and a reduction gear. Although not shown, a gear pump and a molding die are provided on the distal end side of the screw 11.
[0015]
A hopper 13 for charging a rubber material is provided slightly downstream from the root side of the screw 11. A suction port 14 is provided at a central position of the screw 11, and is connected to a vacuum pump. As shown in FIG. 2, a compression section 15 is provided at a central position of the screw 11. In the compression section 15, the rubber material is compressed, and when it passes therethrough, it is formed into a thin sheet shape. Further, the suction port 14 is disposed immediately downstream of the compression section 15, and the downstream side of the compression section 15 forms a vacuum chamber.
[0016]
The reason why the vacuum chamber is formed is to remove air and moisture contained in the rubber material, gas and moisture generated from the compounding chemicals, and discharge the gas from the suction port 14. Therefore, the rubber material passing through the vacuum chamber is formed thin in the compression section 15. This is because if the thickness of the rubber material is large, the inside of the vaporizable substance is difficult to be removed.
[0017]
Next, the configuration of the compression unit 15 will be described. In the compression section 15, the screw 11 is provided with a large-diameter section 11a. The large diameter portion 11 a is provided separately from the blade of the screw 11. In order to set a gap δ between the inner wall surface of the cylinder and the large-diameter portion 11a (corresponding to the outer surface) of the screw 11, a spacer ring 16 (corresponding to a gap adjusting member, a ring-shaped member) is configured to be detachable. ing. A concave portion 10c is formed in the cylinder 11, and a spacer ring 16 is fitted into the concave portion 10c.
[0018]
In the above configuration, the gap amount δ is set to about 1 to 2.5 mm. This gap amount δ affects the effect of discharging gas, moisture, and the like, and has an optimal numerical value. Further, if the composition or type of rubber is changed, physical properties such as viscosity change, so that it is necessary to change the setting of the gap amount. In addition, if the operation of the vacuum extruder is continued, the compression part gradually wears out, so that the spacer ring 16 needs to be appropriately replaced. Therefore, the spacer ring 16 is detachably configured so that it can be easily replaced. Next, a mechanism for replacing the spacer ring 16 will be described.
[0019]
First, the cylinder 11 is divided into a first cylinder portion 10a and a second cylinder portion 10b before and after the compression portion 15. The first cylinder portion 10a is configured to be able to be moved forward by a moving mechanism. FIG. 4 is a diagram illustrating a state in which the first cylinder unit 10a has been moved forward. Thereby, the compression part 15 is exposed to the outside. Although the concave portion 10c described above is formed in the first cylinder portion 10a, it may be formed in the second cylinder portion 10b as shown in FIG. A first contact surface 10d and a second contact surface 10e are respectively formed at the boundaries where the first cylinder portion 10a and the second cylinder portion 10b are divided, and these contact surfaces 10d and 10e are usually brought into close contact with each other. The inside can be sealed by bolting.
[0020]
FIG. 3 is a perspective view showing the configuration of the spacer ring 16. The spacer ring 16 has a split structure of a first member 16a and a second member 16b. The spacer ring 16 is preferably configured by dividing the ring-shaped member into a plurality of pieces along the circumferential direction. In the example of FIG. 3, the spacer ring is divided into two, but may be divided into three or more. Since the spacer ring 16 is divided, the work of attaching and detaching the spacer ring 16 to and from the recess 10c is facilitated. The spacer ring 16 is formed with a tapered portion 16c. Thereby, the rubber material can be smoothly guided into the gap (see also FIG. 2).
[0021]
The spacer ring 16 has a predetermined inner diameter, and a gap δ is formed between the inner diameter portion and the large diameter portion 10 a of the screw 11. When the setting of the gap δ is changed, various spacer rings 16 having different inner diameters may be prepared.
[0022]
<Operation of vacuum extruder>
In order to form a rubber molded product, first, a rubber material is charged from the hopper 13. The screw 11 is driven to rotate, and the rubber is plasticized while being compressed and kneaded, and is gradually pushed forward. After passing through the compression section 15, the rubber material is made into a thin sheet shape. After passing through the compression unit 15, it is a vacuum chamber, and the gas, vaporized moisture, and the like inside the rubber material are discharged from the suction port 14. The kneaded rubber material is extruded further forward from the distal end side of the screw 11, and extruded as a rubber molded product having a predetermined cross-sectional shape via a gear pump and a molding die.
[0023]
Next, the operation for replacing the spacer ring 16 will be described. The screw 11 is stopped, and the first cylinder portion 10a is moved forward. Thereby, as shown in FIG. 4, the compression part 15 is exposed. Then, the spacer ring 16 is taken out from the concave portion 10c, and another spacer ring 16 is mounted. Next, the first cylinder portion 10a is moved backward to return to the original sealed state. As described above, the replacement work of the spacer ring 16 can be easily performed.
[0024]
<Another embodiment>
(1) In this embodiment, the spacer ring 16 is configured to be detachable from the cylinder 10, but may be configured to be detachable from the outer surface of the screw 11. In this case, if a fitting groove corresponding to the width dimension of the spacer ring 16 is formed in the screw 11, the spacer ring 16 can be positioned at a predetermined position.
[0025]
(2) In the present embodiment, only the first cylinder portion 10a is configured to be movable in the front-rear direction, but only the second cylinder portion 10b may be configured to be movable. Further, both the first cylinder portion 10a and the second cylinder portion 10b may be configured to be movable. Instead of dividing the cylinder 10, an opening / closing door may be provided at the position of the compression unit, and the compression unit may be exposed by opening the door.
[0026]
(3) In this embodiment, the spacer ring 16 is divided in the circumferential direction. However, the ring may not be divided. In this case, if the screw 11 can be divided before and after the compression unit 15, even a closed ring can be easily replaced.
[Brief description of the drawings]
FIG. 1 is a schematic diagram showing a configuration of a vacuum extruder according to the embodiment. FIG. 2 is an enlarged view of a main part of the vacuum extruder shown in FIG. 1. FIG. 3 is a perspective view showing a configuration of a spacer ring. 4 is a diagram showing a state in which the first cylinder portion is moved forward. FIG. 5 is a diagram showing a configuration example in which a concave portion is formed in the second cylinder portion. FIG. 6 is a diagram showing a configuration of a vacuum extruder according to the prior art. Schematic diagram [Explanation of reference numerals]
DESCRIPTION OF SYMBOLS 10 Cylinder 10a 1st cylinder part 10b 2nd cylinder part 10c Concave part 11 Screw 11a Large diameter part 12 Screw 13 Hopper 14 Suction port 15 Compression part 16 Spacer ring 16a First member 16b Second member

Claims (4)

A cylinder, a screw provided in the cylinder, a compression unit set so that a gap between the screw and the inner wall surface of the cylinder is narrowed, and a vacuum chamber arranged downstream of the rubber extruder from the compression unit. Rubber extruder,
A vacuum extruder for rubber, wherein a gap adjusting member for adjusting the amount of the gap between the screw and the inner wall surface of the cylinder is detachably provided in the compression section. The vacuum extruder for rubber according to claim 1, wherein the gap adjusting member is a ring-shaped member fitted to an inner wall surface of the cylinder or an outer surface of the screw. The rubber extruder according to claim 2, wherein the ring-shaped member is constituted by a plurality of members divided in a circumferential direction. The cylinder is configured to be divided into a first cylinder portion and a second cylinder portion in the front-rear direction of the compression portion, and configured to expose the compression portion when a gap adjusting member is attached and detached. The vacuum extruder for rubber according to any one of claims 1 to 3.

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