JP2572911B2 - Rubber kneading machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rubber kneader. More specifically, when performing a so-called finishing kneading (a relatively small amount of a drug is added) in which a vulcanizing agent is mixed with rubber, a drug is efficiently dispersed in the rubber by providing a screw extruder with a drug press-in means, The present invention relates to a rubber kneader that can be mixed (hereinafter, simply referred to as a kneader).

[0002]

2. Description of the Related Art Conventionally, a process of mixing and dispersing a drug such as a vulcanization accelerator into rubber by a drug mixer in advance, and then supplying the rubber containing the drug to an extruder to mix and extrude the rubber. Two steps of a molding step were required.

[0003] As the chemical mixer, for example, a closed mixer, an open roll type warming machine and the like are known.

[0004]

As described above, conventionally, a process of adding and dispersing a drug is required before mixing and extruding rubber, so that it is necessary to prepare a drug mixing machine, so that the manufacturing cost is reduced. Had the problem of being extremely expensive. Further, if the storage period after mixing the chemicals exceeds 2 weeks, there is a problem that the rubber is deteriorated.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and a rubber kneader capable of greatly improving the productivity of a rubber material by simultaneously completing the mixing of rubber and the uniform dispersion of a drug. The purpose is to supply.

[0006]

The rubber kneader of the present invention comprises:
A cylinder, a screw having an external thread, housed concentrically in the cylinder, and rotatable around its own axis; and a rubber supply provided near one end of the cylinder for supplying rubber into the cylinder. A hopper and a medicine press-fitting means which is provided at a certain distance from the rubber supply hopper of the cylinder along the axis of the cylinder, the medicine press-fitting means comprising a medicine supply hopper for supplying a medicine into the cylinder; The medicine supply hopper is formed of a threaded rod that penetrates through the cylinder from the bottom of the medicine supply hopper, has an external thread, and is rotatable around its own axis. A slit through which the threaded rod can pass when rotating is formed in a plane perpendicular to the axis of the screw.

The distance between the end of the supply hole communicating with the rubber supply hopper into the cylinder and the center of the screw rod and the center of the threaded rod is 1.5 mm of the lead of the external thread of the screw.
It is preferably at least two times.

Preferably, the direction in which the threaded rod projects is the radial direction of the cylinder.

[0009]

The screw is screwed into the rubber in the mixing process (moving along the screw valley of the screw) by the screw, and the drug is mixed by rotating the screw rod of the press-fitting means. In this case, the drug is screwed into the rubber by the rotation of the screw rod, and the rubber is also suitably dispersed by stirring. Further, since the screw rod revolves relatively to the screw due to the rotation of the screw, the screw rod stirs in the circumferential direction of the screw so as to cut off the flow of rubber, so that the dispersion efficiency of the drug is dramatically improved. After that, the rubber is in contact with the inner surface of the cylinder and the surface of the screw by the rotation of the screw until it is extruded, so that good mixing is achieved.

[0010]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a kneader according to the present invention.

FIG. 1 is a partially cutaway front view showing an embodiment of the kneading machine of the present invention, and FIG. 2 is a cross-sectional view showing an embodiment of a medicine press-fitting means in the kneading machine of FIG.

FIG. 1 schematically shows the entire kneader 1.

Reference numeral 2 denotes a cylinder in which a screw 3 is accommodated concentrically. An extrusion port 4 through which rubber is extruded is opened at one end of the cylinder 2, and a rotation drive device 5 for rotating the screw 3 is provided at the other end. The rotation drive device 5 rotates the screw 3 via a transmission gear by an electric motor, an air motor, or the like. Then, adjacent to the rotary drive device 5, the cylinder 2
A rubber supply hopper 6 for supplying rubber into the inside is provided.

In the direction from the rubber supply hopper 6 to the extrusion port 4,
Approximately 1. of the lead L of the screw 12 (described later) of the screw 3
At a position five times apart, a medicine injecting means 7 for injecting a medicine such as a vulcanization accelerator into the cylinder 2 is provided.
In the present invention, as described above, the separation distance between the rubber supply hopper and the medicine press-fitting means is determined by the distance of the screw lead L of the screw.
Although it is not limited to 1.5 times, at the chemical injection position, the rubber has already wound the screw 3 one or more times, and the separation distance between them is 1.5 L or more in that the flow is stable. preferable. The medicine press-fitting means 7 includes a screw rod 8 having a male screw 8a for screwing the medicine into the cylinder 2, and a medicine supply hopper 9 for accumulating the medicine around the screw rod 8.

The screw rod 8 is mounted on a bracket 10 fixed to the upper surface of the cylinder 2 via a thrust bearing 10a so as to be rotatable but not movable in the axial direction (see FIG. 2). . The screw rod 8 protrudes into the cylinder 2 through the bottom of the medicine supply hopper 9 and the wall of the cylinder 2 in the radial direction of the cylinder 2. Preferably, the screw rod 8 is detachably attached to the bracket 10 to facilitate cleaning. A bevel gear 11a is fixed to the upper end of the screw rod 8. A drive shaft 12 for transmitting a rotational force extends from the rotary drive device 5 in parallel with the cylinder 2. The drive shaft 12 has a bevel gear 11 b meshing with the bevel gear 11 a.
Is fixed. That is, the rotation drive device 5 has a role of driving both the screw 3 and the screw rod 8.
Needless to say, a drive device only for driving the screw rod 8 may be separately provided. The screw rod 8 is configured to rotate in the direction of retracting the screw (in the case of a right screw, rotate left).

A screw 12 is formed on the outer periphery of the screw 3. The screw 12 shown in FIGS. 1 and 2 is a right-hand thread,
A left-hand thread may be used, in which case the direction of rotation must be reversed. The screw 12 shown in FIGS. 1 and 2 is a double thread from the rubber supply hopper 6 to immediately before the medicine press-fitting means 7,
A single thread is formed from the medicine press-fitting means 7 to the extrusion port 4. However, the present invention is not limited to this, and for example, it may be a double-threaded screw over the entire length of the screw 3 or a single-threaded screw over the entire length. In addition,
If the portion of the screw 3 corresponding to the drug press-fitting means 7 is a double thread, a separate threaded rod 8 needs to be inserted into each of two adjacent screw valleys. This is because if the drug is a powder, it may not be possible to continuously inject it into the rubber, and in such a case, it is necessary to prevent the generation of rubber (screw valley) to which the drug is not added at all. is there.

The screw rod 8 protrudes into the valley of the screw 12 and reaches near the bottom of the valley.
A slit 13 is formed in a plane perpendicular to the axis of the screw 3 so that the threaded rod 12 can pass when rotating. If the size of the slit 13 is too large, the rubber does not easily move and the feeding of the rubber becomes difficult. Also,
An appropriate gap is provided between the crest of the screw thread and the inner surface of the cylinder 2, and the root of the screw 12 forms a rubber feed passage 14.

It is preferable that the lead of the screw 12 of the screw 3 from the rubber supply hopper 6 to the medicine press-fitting means 7 is kept constant without being changed. This is because, by this, the amount of drug added can be easily quantified.

The material of the threaded rod 8 is not particularly limited as long as it has excellent wear resistance and is a tough metal.
Nickel chrome class is preferably used.

The use of the kneader 1 configured as described above will be described.

The rotation driving device 5 supplies the rubber from the rubber supply hopper 6 while rotating the screw 3 and the screw rod 8, and fills the medicine from the medicine supply hopper 9. When the screw 3 is rotated so that the screw 12 (right-hand screw) rotates counterclockwise (indicated by an arrow A in FIGS. 1 and 2), the filled rubber is mixed through the feed passage 14 from the rubber supply hopper 6 side. While being sent to the extrusion port 4.

On the other hand, the screw rod 8 of the medicine press-fitting means 7 is inserted into the rubber flowing through the feed passage 14 and rotates in the direction of loosening the screw (indicated by an arrow B in FIG. 2) (movement in the axial direction). As a result, the rubber is moved toward the axis from the inner surface side of the cylinder 2 while stirring the rubber. Therefore, the drug that has reached the rubber from the drug supply hopper 7 via the male screw 8a of the screw rod 8 is screwed into the rubber toward the bottom of the feed passage 14. The drug thus screwed is efficiently dispersed in the rubber by the rotation of the screw rod 8 and the relative revolution with respect to the screw 3. Further, it goes without saying that the medicine is dispersed even from the medicine press-fitting means 7 to the extrusion port 4 by the mixing function (by rotation of the screw 3, etc.) originally provided as a screw extruder.

As described above, the addition of a drug and the kneading of the added rubber can be simultaneously performed by the present kneading machine, which has been conventionally performed in another process by another apparatus. In order to cover a slight decrease in the rubber kneading effect due to the conventional two-step kneading in one step, even if a method such as slightly increasing the length of the screw is adopted, the manufacturing cost of the apparatus is increased. Is greatly reduced, and rubber productivity is dramatically improved. Further, since the chemicals can be mixed for the required time and amount, the kneading and production plan of the rubber can be set more precisely and efficiently.

The projecting direction of the threaded rod is the radial direction of the cylinder 2 in FIGS. 1 and 2, but is not limited to the radial direction in the present invention. It may be inclined or inclined in the direction of rubber flow. However, it is preferable to protrude the screw rod in the radial direction in that the slit of the screw thread can be reduced.

The outer diameter of the threaded rod, the pitch and the number of rotations of the male screw may be appropriately selected according to the amount of rubber extruded. Usually, the outer diameter is 30 to 80 mm, the pitch of the male screw is 30 to 80 mm, and the number of rotations is It is selected in the range of 5 to 50 rpm.

The kneading machine of the present invention comprises a screw extruder provided with a drug press-in means having a screw rod. The type of the screw extruder employed in the present invention is not particularly limited as long as it has a high mixing efficiency.For example, a fixed mixing pin as shown in JP-B-56-53500 is protruded from the inner surface of the cylinder. A screw extruder with improved mixing efficiency and the like are preferred.

[0027]

The kneader of the present invention has an effect that the medicine can be efficiently and uniformly dispersed in the rubber, and the operation can be performed simultaneously in the steps of mixing and extruding the rubber.

[Brief description of the drawings]

FIG. 1 is a partially cutaway front view showing an embodiment of a kneading machine of the present invention.

FIG. 2 is a sectional view showing an embodiment of a medicine press-fitting means in the kneading machine of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Kneader 2 Cylinder 3 Screw 6 Rubber supply hopper 7 Drug press-in means 8 Screw rod 8a Male screw 9 Drug supply hopper 12 Screw 13 Slit

 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-4-358814 (JP, A) JP-A-61-213121 (JP, A) JP-A 58-48419 (JP, U)

Claims (3)

(57) [Claims] 1. A cylinder, a screw having an external thread, housed concentrically in the cylinder, and rotatable around its own axis, and provided near one end of the cylinder.
A rubber supply hopper for supplying rubber into the cylinder,
Drug press-in means provided at a certain distance from the rubber supply hopper of the cylinder along the axis of the cylinder, the drug press-in means comprising a drug supply hopper for supplying a drug into the cylinder; When the screw rotates on the screw thread of the external screw of the screw, the screw rod has an external thread and is rotatable around its own axis. Wherein a slit through which the screw rod can pass is formed in a plane perpendicular to the axis of the screw. 2. A distance between an end edge of a supply hole communicating with the rubber supply hopper into the cylinder and a center of the screw rod and a center of the screw rod is equal to 1.1 of an external screw lead of the screw.
2. The rubber kneader according to claim 1, which is at least 5 times. 3. The rubber kneading machine according to claim 1, wherein said screw rod is provided so as to protrude in a radial direction of the cylinder.