JP2020055242A - Die plate and rubber extruder - Google Patents

Abstract

To provide a die plate capable of improving productivity of rubber extrusion molding, and a rubber extruder including the die plate.SOLUTION: An objective die plate includes a plate body 6 having a first face 6a faced to a rubber extruder 2 side, and a second face 6b of a side opposite thereto. The plate body 6 has: an inflow port 6c having an opening at a side of the first face 6a for receiving a rubber G from the extruder 2; a discharge port 6d having the opening at the side of the second face 6b for discharging the rubber G in a finished sectional shape; and a rubber flow channel 7 which is a space communicating the inflow port 6c with the discharge port 6d. The inflow port 6c is a long opening long in a first axial direction a and short in a second axial direction orthogonal to the first direction a. The rubber flow channel 7 includes a flow channel reduction part 7a in which the length in the second axial direction b reduces toward the discharge port 6d side from the inflow port 6c in the cross section orthogonal to the first axial direction a. The flow channel reduction part 7a is formed over the whole range in the first axial direction a.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a die plate for a rubber extruder and a rubber extruder including the die plate.

  Conventionally, a die plate used for a rubber extruder has been known. The die plate is provided downstream of the rubber extruder in the rubber extrusion direction in order to define the finished cross-sectional shape of the rubber member extruded from the rubber extruder. For example, Patent Literature 1 below proposes a die plate in which a rubber stagnation portion is provided on both sides of a rubber extrusion channel to prevent the extruded rubber member from being cut at an edge portion.

JP 2014-205331 A

  However, the die plate disclosed in Patent Document 1 has a problem that when rubber is extruded at a high speed, the surface of the extruded rubber member is wavy. For this reason, in the rubber extruder including the die plate disclosed in Patent Document 1, it is difficult to increase the extrusion speed, and there is a problem that the productivity of rubber extrusion molding is reduced.

  The present invention has been devised in view of the above situation, and has as its main object to provide a die plate capable of improving the productivity of rubber extrusion molding and a rubber extrusion device including the die plate.

  The present invention is a die plate for a rubber extruder, including a plate body having a first surface facing the rubber extruder side and a second surface opposite to the first surface, wherein the plate body has the first surface. Opening on the surface side, and an inlet for receiving rubber from the rubber extruder, and an opening for opening on the second surface side, and discharging the rubber in a finished cross-sectional shape, A rubber flow path that is a space communicating the inflow port and the discharge port, wherein the inflow port is long in a first axis direction and orthogonal to the first axis direction in a front view of the first surface. The rubber passage has a length in the second axis direction from the inflow port toward the discharge port side in a cross section orthogonal to the first axis direction. A channel reducing portion that decreases, wherein the channel reducing portion is Characterized in that it is formed over the entire range of the axial direction.

  In the die plate of the present invention, it is preferable that the rubber flow path includes the same flow path portion having a constant length in the second axis direction in a cross section orthogonal to the first axis direction.

  In the die plate of the present invention, in the cross section orthogonal to the first axis direction, the same channel portion has a length in a third axis direction orthogonal to the second axis direction, the length of the first surface and the second surface. Is preferably at least 25% of the distance between the two.

  In the die plate of the present invention, a back side chamfer is provided between the flow passage reducing portion and the same flow passage portion, and the back side chamfer extends over the entire range in the first axial direction. Preferably, it is formed.

  In the die plate of the present invention, it is preferable that the back side chamfer is an arc-shaped chamfer.

  In the die plate of the present invention, it is preferable that a front side chamfer is provided between the same channel and the second surface.

  The present invention is a rubber extruder including the above-described die plate, the rubber extruder provided with an extrusion opening for extruding the rubber, and a preformer for connecting the die plate and the rubber extruder, The preformer has an extrusion flow path that is a space that connects the inflow port and the extrusion port, and the length of the extrusion flow path in the second axial direction on the die plate side is equal to the length of the inflow port. It is substantially equal to the length in the second axis direction.

  In the rubber extruder of the present invention, the rubber extruder includes a first rubber extruder that extrudes a first rubber, and a second rubber extruder that extrudes a second rubber, and the extrusion flow path includes the first rubber extruder. It is desirable to include a merging portion for merging the second rubber with the second rubber.

  In the die plate of the present invention, the rubber flow path includes a flow path reduction portion whose length in the second axis direction decreases from the inflow port toward the discharge port side in a cross section orthogonal to the first axis direction. The road reduction portion is formed over the entire range in the first axis direction. Such a die plate allows the rubber to flow smoothly in the rubber flow path, and can even out the surface of the rubber member that is extruded even when the rubber is extruded at a high speed. For this reason, the die plate of the present invention can improve the productivity of rubber extrusion molding.

It is a sectional view showing one embodiment of a rubber extrusion device of the present invention. It is a front view of the 1st surface of the die plate of this embodiment. It is an expanded sectional view of a die plate. It is an expanded sectional view of a die plate of other embodiments.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a cross-sectional view of the rubber extruder 1 of the present embodiment. As shown in FIG. 1, a rubber extruder 1 of the present embodiment includes a rubber extruder 2, a die plate 3, and a preformer 4 for connecting the die plate 3 and the rubber extruder 2. The rubber extrusion device 1 is suitable for extruding, for example, a rubber member Gm suitably used for a tire component such as tread rubber.

  The rubber extruder 2 extrudes the rubber G in the extrusion direction d while kneading the rubber G by, for example, the screw 5. As the rubber extruder 2, a conventionally well-known one suitable for extruding the rubber G can be appropriately used. The rubber extruder 2 includes, for example, an extrusion port 2a for extruding the rubber G. In the rubber extruder 1 of the present embodiment, the extrusion port 2 a of the rubber extruder 2 is connected to the preformer 4.

  The rubber extruder 2 includes, for example, a first rubber extruder 2A that extrudes the first rubber G1, and a second rubber extruder 2B that extrudes the second rubber G2. The first rubber extruder 2A and the second rubber extruder 2B of the present embodiment each include an extrusion port 2a and a screw 5. Note that the number of rubber extruders 2 is not limited to two, and may be one or three or more.

  When there are two rubber extruders 2, the first rubber G1 and the second rubber G2 may have different viscosities, for example. When the rubber member Gm is a tread rubber of a tire, the rubber member Gm includes, for example, a high-viscosity first rubber G1 and a low-viscosity second rubber G2 to achieve both steering stability and low fuel consumption. Tire that can be manufactured.

  The die plate 3 of the present embodiment is suitably used for defining the rubber G extruded from the rubber extruder 2 as a finished sectional shape of the rubber member Gm. The die plate 3 includes, for example, a plate body 6 having a first surface 6a directed toward the rubber extruder 2 and a second surface 6b opposite to the first surface 6a.

  The plate body 6 has an inlet 6c for receiving the rubber G from the rubber extruder 2, an outlet 6d for discharging the rubber G in a finished sectional shape, and a space communicating the inlet 6c and the outlet 6d. It is desirable to have a rubber flow path 7 which is The inflow port 6c of the present embodiment is open on the first surface 6a side. The discharge port 6d of the present embodiment is open on the second surface 6b side.

  FIG. 2 is a front view of the first surface 6 a of the die plate 3. As shown in FIG. 2, when viewed from the front of the first surface 6 a of the die plate 3, the inflow port 6 c is long in the first axial direction a and in the second axial direction b orthogonal to the first axial direction a. Preferably, the opening is short and long. Such an inflow port 6c can efficiently feed a large amount of rubber G into the rubber flow path 7.

  FIG. 3 is an enlarged sectional view of the die plate 3. As shown in FIGS. 2 and 3, the rubber flow path 7 of the present embodiment has a length in the second axial direction b from the inflow port 6 c toward the discharge port 6 d in a cross section orthogonal to the first axial direction a. L1 includes a channel reduction portion 7a that decreases. It is desirable that the flow path reducing portion 7a is formed over the entire range in the first axial direction a.

  Such a die plate 3 allows the rubber G to flow smoothly in the rubber flow path 7 and can smooth the surface of the rubber member Gm extruded even when the rubber G is extruded at a high speed. Further, even when the die plate 3 has two rubber extruders 2 and the difference in viscosity between the first rubber G1 and the second rubber G2 is large, the surface of the rubber member Gm to be extruded can be reduced. Can be smoothed. For this reason, the die plate 3 of the present embodiment can improve the productivity of rubber extrusion molding.

  As a more preferred embodiment, the rubber flow channel 7 has the same length L2 in the second axial direction b on the discharge port 6d side of the flow channel reducing portion 7a in a cross section orthogonal to the first axial direction a. 7b. It is desirable that the same flow path portion 7b is substantially equal to the finished cross-sectional shape of the rubber member Gm. Such a rubber channel 7 can define an arbitrary finished cross-sectional shape of the rubber member Gm.

  In the cross section orthogonal to the first axis direction a, the length L3 of the third channel direction c orthogonal to the second axis direction b is preferably equal to or less than the length L3 of the first surface 6a and the second surface 6b. It is 25% or more of the distance L4. The same flow path portion 7b can improve the accuracy of the finished cross-sectional shape of the rubber member Gm. Note that the extrusion direction d of the rubber G of the present embodiment is a direction substantially along the third axis direction c.

  As shown in FIGS. 1 to 3, the plate body 6 of the present embodiment includes a first plate 6 </ b> A provided on one side in the second axial direction b and a second plate 6 </ b> B provided on the opposite side. Contains. The first plate 6A has, for example, a concave portion that forms the rubber flow channel 7. The second plate 6 </ b> B has, for example, a substantially rectangular parallelepiped shape, and forms a part of the rubber channel 7. Such a plate body 6 is easy to maintain, and the production cost can be reduced because only the first plate 6A needs to be replaced when the shape of the rubber flow path 7 is changed.

  As shown in FIG. 1, the preformer 4 has, for example, an extrusion flow path 8 which is a space communicating the inflow port 6 c of the die plate 3 and the extrusion port 2 a of the rubber extruder 2. Desirably, the extrusion flow path 8 includes a merging portion 8a for merging the first rubber G1 and the second rubber G2. Such an extrusion flow channel 8 can smoothly merge the first rubber G1 and the second rubber G2.

  For example, the preformer 4 includes a first base preformer 4A on the die plate 3 side, a second base preformer 4B on the rubber extruder 2 side, and a first base preformer 4A and a second base preformer 4B. And a preformer main body 4C arranged in the main body. The junction 8a of the extrusion flow path 8 is desirably provided in the preformer main body 4C. Such a preformer 4 is easy to maintain and can share components, so that production costs can be reduced.

  The length L5 in the second axial direction b of the extrusion flow path 8 of the preformer 4 on the die plate 3 side is substantially equal to the length L1 (shown in FIG. 3) of the inflow port 6c of the die plate 3 in the second axial direction. Desirably equal. Such a rubber extruder 1 can efficiently flow the rubber G, and can improve productivity.

  FIG. 4 is an enlarged sectional view of a die plate 10 according to another embodiment. As shown in FIG. 4, the die plate 10 of this embodiment includes a plate main body 11 having a first surface 11a and a second surface 11b opposite thereto, similarly to the above-described die plate 3.

  The plate body 11, like the plate body 6, has an inflow port 11c for receiving the rubber G, a discharge port 11d for discharging the rubber G in a finished sectional shape, and a communication between the inflow port 11c and the discharge port 11d. It is desirable to provide a rubber flow path 12 which is a space for forming. The inflow port 11c of this embodiment is open on the first surface 11a side. The discharge port 11d of this embodiment is open on the second surface 11b side.

  In the rubber flow channel 12 of this embodiment, a cross section orthogonal to the first axial direction a has a flow channel reducing portion 12a in which the length L6 in the second axial direction b decreases from the inflow port 11c toward the discharge port 11d. Contains. The channel reduction portion 12a is desirably formed over the entire range in the first axial direction a, similarly to the channel reduction portion 7a described above.

  Such a die plate 10 can smoothly flow the rubber G in the rubber flow channel 12 and can smooth the surface of the rubber member Gm that is extruded even when the rubber G is extruded at a high speed. For this reason, the die plate 10 of this embodiment can also improve the productivity of rubber extrusion molding.

  The rubber flow channel 12 of this embodiment has the same length L7 in the second axial direction b on the side of the discharge port 11d of the flow channel reducing portion 12a in the cross section orthogonal to the first axial direction a. Contains. The length L8 of the same flow path portion 12b in the third axial direction c is preferably at least 25% of the distance L9 between the first surface 11a and the second surface 11b. The same flow path portion 12b can improve the accuracy of the finished cross-sectional shape of the rubber member Gm.

  A back side chamfer 12c is provided between the flow passage reducing portion 12a and the same flow passage portion 12b in this embodiment. The back side chamfered portion 12c is desirably formed over the entire range in the first axial direction a. Such a back side chamfer 12c can prevent the rubber G in the rubber flow channel 12 from being caught and can smooth the surface of the rubber member Gm that is extruded even when the rubber G is extruded at a high speed.

  The back side chamfer 12c is, for example, an arc-shaped chamfer. The length L10 of the back side chamfer 12c in the third axial direction c is preferably 5% to 15% of the distance L9 between the first surface 11a and the second surface 11b. The back side chamfered portion 12c can achieve both the accuracy of the finished cross-sectional shape of the rubber member Gm and the productivity of rubber extrusion molding.

  A front side chamfered portion 14 is provided between the same flow passage portion 12b and the second surface 11b in this embodiment. The front side chamfer 14 is preferably formed over the entire range in the first axial direction a. Such a front side chamfering portion 14 can prevent the rubber member Gm discharged from the discharge port 6d from being caught and can smooth the surface of the rubber member Gm that is extruded even when the rubber G is extruded at a high speed. .

  The front side chamfer 14 is, for example, an arc-shaped chamfer. The length L11 of the front side chamfer 14 in the third axial direction c is preferably 5% to 15% of the distance L9 between the first surface 11a and the second surface 11b. Such a front side chamfer 14 can achieve both the accuracy of the finished cross-sectional shape of the rubber member Gm and the productivity of rubber extrusion molding.

  As described above, particularly preferred embodiments of the present invention have been described in detail. However, the present invention is not limited to the above-described embodiments, and can be implemented in various modes.

2 Rubber Extruder 3 Die Plate 6 Plate Body 6a First Surface 6b Second Surface 6c Inlet 6d Discharge Port 7 Rubber Channel 7a Channel Reduction Section

Claims (8)

A die plate for a rubber extruder,
A plate body having a first surface facing the rubber extruder side and a second surface opposite to the first surface,
The plate body is opened on the first surface side, and has an inflow port for receiving rubber from the rubber extruder, and is opened on the second surface side, and discharges the rubber in a finished sectional shape. Outlet, and a rubber flow path which is a space communicating the inflow port and the discharge port,
In a front view of the first surface, the inflow port is a long opening that is long in a first axis direction and short in a second axis direction orthogonal to the first axis direction,
The rubber flow path includes a flow path reducing portion whose length in the second axis direction decreases from the inflow port toward the discharge port side in a cross section orthogonal to the first axis direction,
The flow path reducing portion is formed over the entire range in the first axis direction.
Die plate.   2. The die plate according to claim 1, wherein the rubber flow path includes a same flow path portion having a constant length in the second axis direction in a cross section orthogonal to the first axis direction. 3.   In the cross section orthogonal to the first axis direction, the same portion of the flow path has a length in a third axis direction orthogonal to the second axis direction of 25% or more of a distance between the first surface and the second surface. The die plate according to claim 2, wherein A back side chamfer is provided between the channel reducing portion and the same channel portion,
The die plate according to claim 2, wherein the back side chamfer is formed over an entire range in the first axial direction.   The die plate according to claim 4, wherein the back side chamfer is an arc-shaped chamfer.   The die plate according to claim 2, wherein a front side chamfer is provided between the same portion of the flow path and the second surface. A rubber extruder comprising: the die plate according to any one of claims 1 to 6, the rubber extruder provided with an extrusion opening for extruding the rubber; and a preformer for connecting the die plate and the rubber extruder. And
The preformer has an extrusion flow path that is a space that connects the inflow port and the extrusion port,
The length of the extrusion flow path on the die plate side in the second axial direction is substantially equal to the length of the inflow port in the second axial direction.
Rubber extrusion equipment. The rubber extruder includes a first rubber extruder that extrudes a first rubber, and a second rubber extruder that extrudes a second rubber.
The rubber extrusion device according to claim 7, wherein the extrusion flow path includes a joining portion that joins the first rubber and the second rubber.

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