JP2019084792A - Extrusion apparatus - Google Patents

Abstract

To provide an extrusion apparatus capable of suppressing retention of a material.SOLUTION: The extrusion apparatus 1 contains: an extruder 2 having a screw 4 for extruding a plastic material G; and a gear pump 3 having a pair of gears 6 for discharging a material G extruded from the extruder 2. The apparatus contains a communicating channel 10 for sending a material G extruded from the extruder 2 to the gear pump 3. The communicating channel 10 has a first end part 11 on a side of the extruder 2 and a second end part 12 on a side of the gear pump 3. The communicating channel 10 contains, at a cross section orthogonal to its axis of rotation of the gear 6, an enlarged curve part 10a enlarging a diameter of the communicating channel 10 to the side of the second end part 12.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an extrusion device comprising an extruder and a gear pump.

  In the prior art, extruders are known which have a screw for extruding a plastic material such as, for example, an unvulcanized rubber. Such an extruder is capable of continuously extruding a plastic material. The extruder usually rotates the screw continuously, as stopping the screw during the extrusion operation may deteriorate the uniformity of the material and the quality of the extruded material may deteriorate.

  Therefore, for example, as described in Patent Document 1 below, when the device on the downstream side of the extruder is stopped by the gear pump disposed at the extrusion port of the extruder, discharge is performed in a state where the screw of the extruder is rotated. Various extrusion devices have been proposed to stop such materials.

Unexamined-Japanese-Patent No. 2017-087486

  FIG. 5 is a cross-sectional view of a conventional extrusion device as disclosed in Patent Document 1. As shown in FIG. In FIG. 5, the flow of material is indicated by arrows. As shown in FIG. 5, the extrusion device of Patent Document 1 has a communication channel c for sending the material G extruded from the extruder a to a gear pump b. The communication channel c smoothly connects, for example, the shape of the outlet side of the extruder a and the shape of the inlet side of the gear pump b.

  In the extrusion device of Patent Document 1, the material G extruded from the extruder a and the backflowed material G generated by the rotation of the gear of the gear pump b are located in the vicinity of the position indicated as the P point of the communication flow path c There was a problem that the material G stagnated. Such stagnation may inhibit the smooth flow of the material G and reduce the productivity of the material G. In addition, since the material G extruded from the extruder a has a high temperature, the retention of the material G holds the material G in a high temperature state, which may change the quality of the material G.

  The present invention has been made in view of the above-described actual situation, and has as its main object to provide an extrusion device capable of suppressing retention of material.

  The present invention is an extrusion apparatus comprising: an extruder equipped with a screw for extruding a plastic material; and a gear pump having a pair of gears for discharging the material extruded from the extruder. A communication channel for feeding the material pushed out of the machine to the gear pump, the communication channel having a first end on the extruder side and a second end on the gear pump side; In the cross section orthogonal to the rotation axis of the gear, the communication flow path is characterized in that the communication flow path includes an expansion curve portion that enlarges the diameter of the communication flow path on the second end side.

  In the extrusion device of the present invention, it is preferable that the gear pump includes a casing including the gear, and the enlarged curved portion of the communication channel is connected to the inner periphery of the casing without bending.

  In the extrusion device of the present invention, the inner circumferential portion of the casing includes an inner circumferential curved portion along the outer circumferential portion of the gear, and the enlarged curved portion of the communication flow path and the inner circumferential curved portion of the casing It is desirable that it is bent in the opposite direction.

  In the extrusion device of the present invention, the enlarged curved portion of the communication channel preferably has a single radius of curvature.

  In the extrusion apparatus of the present invention, it is desirable that the communication channel has a smallest diameter portion between the first end and the second end, the diameter being the smallest.

  In the extrusion apparatus of the present invention, the minimum diameter portion is preferably formed closer to the second end than the central portion between the first end and the second end in the extrusion direction of the material. .

  In the extrusion apparatus of the present invention, it is preferable to further include a connection portion disposed between the extruder and the gear pump, and the communication channel is formed in an insert inserted into the connection portion.

  In the extrusion apparatus of the present invention, the material is preferably an unvulcanized rubber.

  The extrusion apparatus of the present invention includes a communication channel for sending the material extruded from the extruder to the gear pump, and the communication channel has a first end on the extruder side and a second end on the gear pump side. And, in a cross-section perpendicular to the axis of rotation of the gear, the second end includes a curvilinear portion that increases the width of the communication channel. In such an extrusion device, the curved portion can suppress the backflow of the material due to the rotation of the gear of the gear pump, and the productivity and the quality of the material to be extruded can be improved without retaining the material.

It is sectional drawing which shows one Embodiment of the extrusion apparatus of this invention. It is an expanded sectional view of the extrusion apparatus of FIG. It is sectional drawing which shows the extrusion apparatus of other embodiment. It is an expanded sectional view of the extrusion apparatus of FIG. It is sectional drawing of the conventional extrusion apparatus.

Hereinafter, an embodiment of the present invention will be described in detail based on the drawings.
FIG. 1 is a cross-sectional view showing the extrusion device 1 of the present embodiment, and FIG. 2 is an enlarged cross-sectional view of the extrusion device 1 of FIG. The flow of the material G is shown by the arrow in FIG.

  As shown in FIG. 1 and FIG. 2, the extrusion device 1 of this embodiment includes an extruder 2 for extruding a plastic material G, and a gear pump 3 for discharging the material G extruded from the extruder 2. Contains. The plastic material G is, for example, an unvulcanized rubber.

  The extruder 2 includes, for example, a screw 4 and a substantially cylindrical barrel 5 including the screw 4. The extruder 2 can extrude the material G, which has been fed from a feeding port (not shown) of the barrel 5, in the barrel 5 while being plasticized by the screw 4. Such an extruder 2 can uniformly plasticize the material G and can improve the quality of the extruded material G.

  The gear pump 3 has, for example, a pair of gears 6 and a casing 7 including the gears 6. The gear pump 3 preferably feeds the material G between the gear 6 and the casing 7 by rotating the pair of gears 6 in reverse.

  Such an extrusion device 1 can freely control the change or stop of the discharge amount of the material G by the gear pump 3 in a state where the operation of the extruder 2 is continued, so that the material G with good quality can be obtained. It can discharge quantitatively.

  Here, FIGS. 1 and 2 are cross sections orthogonal to the rotation axis of the gear 6. Hereinafter, based on FIG. 1 and FIG. 2, the extrusion apparatus 1 of this embodiment is demonstrated in the cross section orthogonal to the rotating shaft of the gear 6. As shown in FIG.

  The extrusion device 1 of the present embodiment includes a communication channel 10 for feeding the material G extruded from the extruder 2 to the gear pump 3. The communication channel 10 has a first end 11 which is an end on the extruder 2 side, and a second end 12 which is an end on the gear pump 3 side.

  The first end portion 11 desirably has a shape substantially equal to the shape of the outlet side of the inner peripheral portion of the barrel 5 of the extruder 2. The second end 12 preferably has a shape substantially equal to the shape of the inlet side of the inner peripheral portion of the casing 7 of the gear pump 3. Such a communication channel 10 can smoothly connect the inner peripheral portion of the barrel 5 and the inner peripheral portion of the casing 7 which have different shapes.

  The first end portion 11 of the present embodiment has a first inner diameter d1 substantially equal to the inner diameter of the outlet side of the barrel 5 of the extruder 2. Such an extrusion device 1 can send the material G extruded from the extruder 2 to the gear pump 3 without causing the retention and pressure loss of the material G. The first end portion 11 may be provided with a filter (not shown) for removing foreign matter in the material G.

  The communication channel 10 according to the present embodiment includes an enlarged curved portion 10 a that enlarges the diameter of the communication channel 10 on the second end 12 side. The second end 12 preferably has a second inner diameter d2 substantially equal to the inner diameter of the inlet side of the casing 7 of the gear pump 3.

  In such an extrusion device 1, as shown by the arrows in FIG. 1, the enlarged curved portion 10 a suppresses the backflow of the material G due to the rotation of the gear 6 of the gear pump 3 and does not retain the material G. For this reason, the extrusion device 1 of the present embodiment can improve the productivity and the quality of the material G to be extruded.

  The extrusion device 1 of the present embodiment further includes a connecting portion 8 disposed between the extruder 2 and the gear pump 3. The connecting portion 8 includes, for example, a first connecting portion 13 attached to the extruder 2, a second connecting portion 14 attached to the gear pump 3, and a shell clamp 15 for bringing the first connecting portion 13 and the second connecting portion 14 into close contact. Contains. Such a connecting portion 8 can easily disassemble the extruder 2 and the gear pump 3 and can improve the workability of the maintenance operation.

  As for the connection part 8, it is desirable for the insert 9 to be inserted in the inside. The insert 9 is integrally formed, for example, from the extruder 2 to the gear pump 3. The communication channel 10 is preferably formed in the insert 9 inserted into the connection portion 8. Such a communication channel 10 has no seam inside, and the material G can flow smoothly.

  The connecting portion 8 may not include the insert 9. The communication flow path 10 in the case where the connecting portion 8 does not include the insert 9 is formed, for example, by the inner peripheral portion of the connecting portion 8 and the inner peripheral portion 16 of the casing 7 of the gear pump 3.

  The diameter from the 1st end part 11 to the expansion curve part 10a is the 1st internal diameter d1 of the connection flow path 10 of this embodiment. Such a communication channel 10 can maintain the flow rate in the extrusion direction of the material G without pressure loss.

  The second inner diameter d2 of the present embodiment is the largest diameter portion of the communication flow channel 10. In the present embodiment, the difference between the second inner diameter d2 and the first inner diameter d1 is preferably 20 mm or more. That is, the communication channel 10 of the present embodiment is suitable when the difference between the inner diameter on the inlet side of the casing 7 and the inner diameter on the outlet side of the barrel 5 is 20 mm or more.

  It is desirable that the enlarged curved portion 10a of the communication channel 10 have a single radius of curvature R. The radius of curvature R of the enlarged curved portion 10a is preferably 10 to 25 mm. Such a communication channel 10 can smoothly flow the material G and can improve the productivity of the material G. The enlarged curve portion 10a may be a compound curve having a plurality of curvature radii.

  The enlarged curved portion 10 a of the communication channel 10 of the present embodiment is smoothly connected to the inner circumferential portion 16 of the casing 7 without being bent. That is, a discontinuous point is not formed in the connection part of the expansion curve part 10a of the connection flow path 10, and the inner peripheral part 16 of the casing 7. Such an enlarged curved portion 10 a can smoothly flow the material G, and can further improve the productivity of the material G.

  The inner circumferential portion 16 of the casing 7 of the present embodiment includes an inner circumferential curved portion 16 a along the outer circumferential portion of the gear 6. In the present embodiment, the enlarged curved portion 10a of the communication flow channel 10 and the inner circumferential curved portion 16a of the casing 7 are bent in opposite directions and are smoothly connected without bending. Such a communication channel 10 can allow the material G to flow more smoothly because a straight portion is not formed at the second end 12.

  FIG. 3 is a cross-sectional view showing an extrusion apparatus 20 according to another embodiment, and FIG. 4 is an enlarged cross-sectional view of the extrusion apparatus 20 of FIG. In FIG. 3, the flow of the material G is indicated by an arrow. Those having the same functions as those of the above-described embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  As shown in FIG. 3 and FIG. 4, the extruder 20 of this embodiment includes an extruder 2 for extruding a plastic material G, and a gear pump 3 for discharging the material G extruded from the extruder 2. , And a connecting portion 21 disposed between the extruder 2 and the gear pump 3. The insert 22 is inserted into the inside of the connecting portion 21. The insert 22 is desirably integrally formed from the extruder 2 to the gear pump 3.

  Here, FIG. 3 and FIG. 4 are cross sections orthogonal to the rotation axis of the gear 6 of the gear pump 3. Hereinafter, based on FIG. 3 and FIG. 4, the extrusion apparatus 20 of this embodiment is demonstrated in the cross section orthogonal to the rotating shaft of the gear 6. As shown in FIG.

  The extrusion device 20 of this embodiment includes a communication channel 23 for feeding the material G extruded by the screw 4 of the extruder 2 to the gear pump 3. The communication channel 23 has a first end 24 on the extruder 2 side and a second end 25 on the gear pump 3 side. The communication channel 23 is preferably formed in the insert 22 inserted into the connecting portion 21.

  Desirably, the first end 24 has a first inner diameter d1 substantially equal to the inner diameter of the outlet side of the barrel 5 of the extruder 2. Such an extrusion device 20 can send the material G extruded from the extruder 2 to the gear pump 3 without causing the retention and pressure loss of the material G.

  The communication channel 23 of this embodiment includes an enlarged curved portion 23 a that enlarges the diameter of the communication channel 23 on the second end 25 side. It is desirable that the enlarged curved portion 23a be smoothly connected to the inner circumferential portion 16 of the casing 7 without being bent. Such an enlarged curved portion 23 a can smoothly flow the material G and can improve the productivity of the material G.

  The second end 25 preferably has a second inner diameter d2 substantially equal to the inner diameter of the inlet side of the casing 7 of the gear pump 3. In this embodiment, the difference between the second inner diameter d2 and the first inner diameter d1 is preferably less than 20 mm. That is, the communication channel 23 of this embodiment is suitable when the difference between the inner diameter on the inlet side of the casing 7 and the inner diameter on the outlet side of the barrel 5 is less than 20 mm. Note that the second inner diameter d2 of this embodiment may be smaller than the first inner diameter d1.

  In such an extrusion device 20, as shown by the arrow in FIG. 3, the enlarged curved portion 23a suppresses the backflow of the material G due to the rotation of the gear 6 of the gear pump 3, and does not retain the material G. For this reason, the extrusion device 20 of this embodiment can improve the productivity and quality of the material G to be extruded.

  The communication channel 23 of this embodiment has a minimum diameter portion 26 between the first end portion 24 and the second end portion 25 which has a minimum third inner diameter d3. It is desirable that the diameter of the communication channel 23 gradually decreases from the first end 24 to the minimum diameter portion 26. The third inner diameter d3 of the minimum diameter portion 26 is preferably 60% to 90% of the first inner diameter d1. Such a communication channel 23 can increase the flow velocity in the extrusion direction of the material G.

  The minimum diameter portion 26 is preferably formed closer to the second end 25 than the central portion between the first end 24 and the second end 25 in the extrusion direction of the material G. The minimum diameter portion 26 of this embodiment is formed in the enlarged curved portion 23a. Such a communication flow path 23 can reduce the rate of change in diameter from the first end 24 to the minimum diameter portion 26, and the material G can flow smoothly.

  It is desirable that the enlarged curved portion 23a of the communication channel 23 have a single radius of curvature R. The radius of curvature R of the enlarged curved portion 23a is preferably 10 to 25 mm. Such a communication channel 23 can flow the material G more smoothly, and can improve the productivity of the material G. The enlarged curve portion 23a may be a compound curve having a plurality of curvature radii.

  As mentioned above, although the especially preferable embodiment of this invention was explained in full detail, this invention can be deform | transformed into a various aspect, and can be implemented, without being limited to the above-mentioned embodiment.

  A first extruder having an inner diameter (first inner diameter) of 60 mm on the outlet side or a second extruder having an inner diameter (first inner diameter) of 90 mm on the outlet side, and a gear pump having an inner diameter (second inner diameter) of 90 mm on the inlet side Tests were used to push out the unvulcanized rubber. As shown in Table 1, each embodiment and each example and the extrusion apparatus having the first extruder or the second extruder, the gear pump, and the communication channel of any of FIG. 1, FIG. 3 and FIG. Tests of the comparative example were conducted.

The test was carried out using these extrusion devices to produce rubber strips for 48 hours, and then the presence or absence of rubber retention in the communication channel was confirmed.
The results are shown in Table 1.

  As a result of the test, while the retention of rubber occurred in the extrusion apparatus of the comparative example, the retention of rubber did not occur, and the extrusion apparatus of the example extruded a rubber strip excellent in productivity and quality. confirmed.

DESCRIPTION OF SYMBOLS 1 Extrusion apparatus 2 Extrusion machine 3 Gear pump 4 Screw 6 Gear 10 Connection flow path 10a Enlargement curve part 11 1st end part 12 2nd end part

Claims (8)

An extrusion apparatus comprising: an extruder provided with a screw for extruding a plastic material; and a gear pump having a pair of gears for discharging the material extruded from the extruder,
Including a communication channel for feeding the material extruded from the extruder to the gear pump;
The communication channel has a first end on the extruder side and a second end on the gear pump side.
In a cross section orthogonal to the rotation axis of the gear,
The communication channel includes an enlarged curved portion that enlarges the diameter of the communication channel on the second end side.
Extrusion device. The gear pump includes a casing containing the gear,
The extrusion device according to claim 1, wherein the enlarged curved portion of the communication channel is connected to the inner circumferential portion of the casing without bending. The inner circumferential portion of the casing includes an inner circumferential curved portion along an outer circumferential portion of the gear,
The extrusion device according to claim 2, wherein the enlarged curved portion of the communication channel and the inner circumferential curved portion of the casing are bent in opposite directions.   The extrusion device according to any one of claims 1 to 3, wherein the enlarged curved portion of the communication channel has a single radius of curvature.   The extrusion device according to any one of claims 1 to 4, wherein the communication channel has a smallest diameter portion with a smallest diameter between the first end and the second end.   The extrusion apparatus according to claim 5, wherein the minimum diameter portion is formed closer to the second end portion than a central portion between the first end portion and the second end portion in the extrusion direction of the material. Further comprising a connection disposed between the extruder and the gear pump,
The extrusion device according to any one of claims 1 to 6, wherein the communication channel is formed in an insert inserted into the connection portion.   The extrusion device according to any one of claims 1 to 7, wherein the material is an unvulcanized rubber.

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