JP5053770B2 - Extrusion molding apparatus, method for producing unvulcanized rubber tape, and method for forming unvulcanized rubber cylinder - Google Patents

Description

  The present invention relates to an extrusion apparatus for producing an unvulcanized rubber tape wound around the outer surface of a mandrel when producing a thick rubber cylinder, a method for producing an unvulcanized rubber tape, and an unvulcanized rubber cylinder. The present invention relates to a forming method.

Conventionally, as a method of manufacturing a thick rubber cylinder such as a pumping tube of a squeeze pump, as shown in Patent Document 1, an unvulcanized rubber tape extruded from an extrusion molding apparatus is placed on an outer periphery of a mandrel in an upright state. A method is known in which a cylindrical body is formed by wrapping around a surface and this is vulcanized.
JP-A-2005-180502

  By the way, when the pumping tube is taken as an example of the rubber cylinder, fastening fittings are attached to both ends of the tube. Therefore, when the pumping tube is formed by a method in which an unvulcanized rubber tape is wound around a mandrel, it is necessary to wind over the end fitting (enlarged diameter portion) at both ends of the tube.

  At this time, since the outer diameter of the tube is formed to the same extent as a whole, the width of the unvulcanized rubber tape should be abruptly changed at the boundary between the enlarged diameter portion at both ends of the tube and the other general diameter portion. Is required.

  Patent Document 1 describes a method of adjusting the moving speed of the mandrel as a method of changing the thickness of the rubber cylinder, but this method can cope with a sudden change in the diameter of the object to be wound. In addition, the tape size fluctuates greatly and the tape is cut, which is not practical.

  Therefore, in the present invention, there is an extrusion molding apparatus for producing an unvulcanized rubber tape with adjustable tape width, a method for producing an unvulcanized rubber tape with adjustable tape width, and an enlarged diameter portion in the mandrel. However, it is an object of the present invention to provide a method for forming an unvulcanized rubber cylinder capable of making the outer diameter substantially constant.

  In order to solve the above-mentioned problem, in the present invention, an extrusion die is attached to the head of an extruder and extrudes unvulcanized rubber into a tape shape from a slit-like extrusion port formed in the extrusion die. The extrusion die is provided so as to be relatively movable along the head exit surface while being in contact with the exit surface of the head, and the extrusion die is relatively moved along the head exit surface. Thus, the overlapping portion between the head outlet and the extrusion port is changed, and the width of the rubber tape extruded from the extrusion port is adjusted.

  According to the above configuration, the unvulcanized rubber is extruded from the portion where the extrusion port overlaps the head outlet by arranging the extrusion die on the surface where the head outlet is formed (head outlet surface) without any gap. Therefore, the rubber tape width of the unvulcanized rubber tape can be adjusted by moving the extrusion die relatively to change the overlapping portion between the head outlet and the extrusion port.

  As a specific mode for making the extrusion die relatively movable with respect to the head outlet, for example, the extrusion die is provided in contact with the outlet surface of the head so as to be rotatable on the head outlet surface. The width of the rubber tape extruded from the extrusion port can be adjusted by changing the overlapping portion between the head exit and the extrusion port by rotating on the head exit surface.

  The shape of the head outlet of the extruder is not particularly limited as long as the overlapping portion with the extrusion port is changed by the rotation of the extrusion die, and may be the same shape as the slit shape of the extrusion port. However, if the shape of the head outlet is the same as the slit of the extrusion port, the overlap between the head outlet and the extrusion port will change drastically by slightly rotating the extrusion die. It is necessary to finely adjust the rotation of the die.

  Therefore, in the present invention, the head outlet can be formed in a long hole shape so that the width in the short direction is wider than the slit width of the extrusion port. Thereby, with the rotation of the extrusion die, the change in the overlapping portion between the head outlet and the extrusion port can be moderated, and the adjustment of the rubber tape width is facilitated.

  Moreover, it is preferable to match the center positions of the extrusion port and the head outlet with the position of the rotation center of the extrusion die. Thereby, it becomes possible to extrude from the center part of the unvulcanized rubber tape extrusion die. Accordingly, when the extruded unvulcanized rubber tape is directly wound around the mandrel, the position where the unvulcanized rubber tape is fed out is stabilized, so that the unvulcanized rubber tape can be accurately wound around the mandrel.

  As another aspect of enabling the extrusion die to move relative to the head outlet, the extrusion die is slidably provided along the head outlet surface, and the extrusion die is slid along the head outlet surface to thereby remove the head outlet. It is also possible to adjust the width of the rubber tape extruded from the extrusion port by changing the overlapping portion between the extrusion port and the extrusion port.

  In this case, the extrusion port of the extrusion die is arranged so as to cross the head outlet, and the extrusion die can be slidable in the longitudinal direction of the head outlet. At this time, by forming the horizontal width of the head outlet so as to change in the vertical direction, it is possible to slide the extrusion die and change the overlapping portion between the head outlet and the extrusion port. As a specific shape of the head outlet, for example, it can be formed in a triangle or a trapezoid.

  The unvulcanized rubber tape manufacturing method according to the present invention also includes an extrusion die having a slit-like extrusion port, which is overlapped without any gap at the head outlet of an extruder for extruding unvulcanized rubber, and is not added from the extrusion port. When extruding the vulcanized rubber tape, the extrusion die is relatively movable along the head exit surface, and the extrusion die is moved relatively along the head exit surface while extruding the unvulcanized rubber tape. The overlapping portion between the head outlet and the extrusion port is changed to adjust the width of the rubber tape extruded from the extrusion port.

  According to the above configuration, the tape width can be arbitrarily adjusted in one continuous state without once cutting the unvulcanized rubber tape.

  In addition, the method for forming the unvulcanized rubber cylinder according to the present invention is an enlarged state in which the unvulcanized rubber tape pushed out from the slit-like extrusion port of the extrusion die attached to the head outlet of the extruder is erected. A method for forming an unvulcanized rubber cylinder by spirally winding a mandrel having a diameter portion, wherein an extrusion die is provided to be relatively movable along the head exit surface, and the head exit and By changing the overlapping portion with the extrusion port, the width of the rubber tape extruded from the extrusion port can be adjusted, and when the unvulcanized rubber tape is wound around a mandrel, the unvulcanized rubber tape is applied to the enlarged diameter portion. When winding, adjust the extrusion die to move relatively along the head exit surface so that the width of the rubber tape becomes narrow, and wind the unvulcanized rubber tape around the area other than the enlarged diameter part. Rutoki by adjusting such that the rubber tape width increases, characterized by a substantially constant outer diameter over the entire length.

  According to the said structure, even if an enlarged diameter part exists in a mandrel, it becomes possible to obtain easily the cylinder body made from an unvulcanized rubber with a substantially constant outer diameter. In the method for forming an unvulcanized rubber cylinder according to the present invention, as described above, it can be suitably used as a method for forming a thick inner rubber layer constituting a pumping tube of a squeeze pump.

  That is, since a fitting is attached to the end of the pumping tube, this acts as an enlarged diameter portion. Even in such a case, according to the method for forming an unvulcanized rubber cylinder according to the present invention, even if the width of the unvulcanized rubber tape to be wound is changed, an excessive force is not applied to the tape. It is possible to easily obtain an unvulcanized rubber tubular body having a substantially constant outer diameter without fear of being cut or disturbing the dimensions of the tape.

  In the present invention, an extrusion die having a slit-like extrusion port is overlaid without any gap at the head outlet of an extruder for extruding unvulcanized rubber, and when extruding the unvulcanized rubber tape from the extrusion port, the extrusion die is Overlap between the head outlet and the extrusion port is provided by being relatively movable along the head exit surface and moving the extrusion die relatively along the head exit surface while extruding the unvulcanized rubber tape. The width of the unvulcanized rubber tape can be adjusted by changing the part.

  The present invention will be described below with reference to the drawings. 1 is a cross-sectional view showing an extruder head of an extrusion molding apparatus according to the present invention, FIG. 2 is a front view of the head, and FIG. 3 shows a state in which the extrusion die of FIG. 2 is rotated. It is a front view of a head.

  The extrusion molding apparatus according to the present invention is disposed so as to overlap with an extruder 1 kneading and extruding unvulcanized rubber, a head 2 attached to the tip of the extruder 1, and an exit surface 2a of the head 2 without any gap. And an extrusion die 4. The unvulcanized rubber supplied from the extruder 1 to the extrusion head 2 is formed into a tape shape and extruded from an extrusion port 5 formed in the extrusion die 4.

  The extrusion die 4 is formed in a disk shape, and a slit-shaped extrusion port 5 is formed at the center thereof. The extrusion port 5 is formed in a tapered shape whose inner surface becomes narrower from the head outlet 3 side to the surface side, so that unvulcanized rubber can easily flow into the extrusion port 5. The extrusion die 4 is rotatably held by the guide member 6 on the head exit surface 2a without any gap. The rotation of the extrusion die 4 is controlled by a rotating means composed of a hydraulic cylinder 7.

  The head outlet 3 is formed in a long hole shape so that the width in the short direction is wider than the slit width of the extrusion port 5 and the length in the longitudinal direction is slightly longer than the slit length d of the extrusion port 5. ing. The center of the head outlet 3 and the center of the extrusion port 5 are formed so as to coincide with the rotation center of the extrusion die.

  In the above configuration, when the extrusion die 4 is not rotated, as shown in FIG. 2, the entire extrusion port 5 overlaps with the head outlet 3, so that the slit length d of the extrusion port 5 is not pushed out as it is. This is the tape width of the vulcanized rubber tape.

  When the extrusion die 4 rotates, as shown in FIG. 3, the unvulcanized rubber tape is pushed out from the overlapping portion E (shaded portion) between the central portion of the extrusion port 5 and the central portion of the head outlet 3, so that the tape width is narrowed. . As described above, the width of the unvulcanized rubber tape to be extruded can be adjusted by rotating the extrusion die 4.

  Next, a method for forming an unvulcanized rubber cylinder on the mandrel 8 having an enlarged diameter portion using the extrusion molding apparatus having the above configuration will be described. FIG. 4 is a schematic view showing a method of forming the inner rubber layer 11 constituting the pumping tube of the squeeze pump as the unvulcanized rubber cylinder. As shown in the figure, a metal fitting 9 is externally mounted on the outer peripheral surface of the mandrel 8. As a result, the general diameter portion A where the fitting 9 does not exist and the enlarged diameter portion B expanded by the fitting 9 are formed on the mandrel 8.

  The unvulcanized rubber tape 10 extruded from the extrusion port 5 of the extrusion molding apparatus is first wound around the enlarged diameter portion B. At this time, the extrusion die 4 is rotated so that the slit of the extrusion port 5 intersects the long hole of the head outlet 3. Thereby, since the unvulcanized rubber tape 10 is extruded from the overlapping part of the head outlet 3 and the extrusion port 5, the width of the rubber tape 10 becomes narrower than the slit length d. The obtained rubber tape 10 is wound around the enlarged diameter portion B in an upright state, that is, with one side surface of the rubber tape 10 contacting the outer peripheral surface of the mandrel 8.

  When the unvulcanized rubber tape 10 is wound around the mandrel 8, the mandrel 8 is moved around the central axis 12 according to the extrusion speed of the rubber tape 10 and moved in the central axis direction C of the mandrel. As a result, the rubber tape 10 can be wound with no gap between the tapes with a certain tension applied.

  When the boundary between the enlarged diameter portion B and the general diameter portion A is reached, the extrusion die 4 is returned to the original state, and the length directions of the head outlet 3 and the extrusion outlet 5 are made to coincide. Thereby, the width of the unvulcanized rubber tape 10 extruded from the extrusion port 5 becomes d which is the same as the length of the slit of the extrusion port 5. That is, it is possible to continuously change the tape width while extruding the rubber tape 10.

  Note that the width of the unvulcanized rubber tape 10 tends to become narrower when it is wound around the mandrel 8 while applying tension, and is set in consideration of that amount. Further, when the unvulcanized rubber tape 10 is actually wound around the mandrel 8, the inclination angle of the tape 10 with respect to the mandrel is changed by adjusting the moving speed and rotation speed of the mandrel 8 in addition to the tape width. The rubber thickness may be adjusted as appropriate.

  According to the above method, even when the general diameter part A and the enlarged diameter part B are mixed in the mandrel 8, the inner surface rubber layer 11 (unvulcanized rubber cylinder) whose outer diameter is substantially constant as a whole. Can be formed. After the inner rubber layer 11 is formed, a reinforcing rubber layer covering the outer peripheral surface and an outer rubber layer covering the outer peripheral surface are formed, followed by vulcanization treatment to form a three-layer pumping tube. Obtainable.

  The reinforcing rubber layer is formed on the outer circumferential surface of the inner rubber layer so that the fiber direction intersects the tube axis at a predetermined molding angle with a sheet-like material obtained by topping a known unvulcanized rubber on a steel cord. Formed by winding two plies.

  In the present embodiment, the embodiment in which the extrusion die 4 is rotatably held on the head exit surface 2a has been described as a specific mode in which the extrusion die 4 is relatively moved along the head exit surface 2a. For example, as shown in FIG. 5, it is possible to adopt a mode in which the extrusion die 4 is held slidably along the head exit surface 2a as another mode.

  That is, in the embodiment shown in FIG. 5, the head outlet 3 is formed in a triangular shape, and there is no gap so that the extrusion die 4 having the slit-like extrusion port 5 crosses the head outlet 3 on the head outlet surface 2 a. The extrusion die 4 is slidable in the longitudinal direction F along the head exit surface 2a.

  In such a configuration, when the extrusion die 4 is slid in the longitudinal direction F, the overlapping portion E between the head outlet 3 and the extrusion port 5 can be changed, and the unvulcanized rubber tape 10 extruded from the extrusion port 5 can be changed. The tape width can be adjusted.

  However, in this case, it should be noted that the width of the unvulcanized rubber tape 10 is not proportional to the moving speed of the extrusion die 4 that is slid in the longitudinal direction F. That is, when the unvulcanized rubber 13 that has been pressurized inside the head 2 is pushed out of the head 2, a force to expand the unvulcanized rubber 13 acts.

  Therefore, when the unvulcanized rubber 13 is extruded directly from the head outlet 3 without passing through the extrusion die 4, the cross section of the extruded unvulcanized rubber 13 has a triangular side as shown in FIG. It becomes a shape that expands outward and curves. Therefore, it is necessary to adjust the moving speed of the extrusion die 4 that is slid in the vertical direction F in consideration of the expansion amount of the unvulcanized rubber 13.

  In the present embodiment, the case where the inner rubber layer of the pumping tube having a three-layer structure is manufactured as an unvulcanized rubber cylinder has been described, but a single-layer structure may be used. Furthermore, the enlarged diameter part may be formed in the cylinder center part. Specifically, in the rubber roller in which rubber is laminated around the shaft core, the present invention can be suitably used when the roller shape is changed to a barrel shape.

Sectional drawing which shows the extruder head of the extrusion molding apparatus which concerns on this invention Front view of the head of FIG. The front view of the head which shows the state which rotated the extrusion die of FIG. Schematic diagram showing the method of forming the inner rubber layer constituting the pumping tube Schematic which shows another aspect of the extruder head and extrusion die in FIG. Schematic showing the cross-sectional shape of the unvulcanized rubber extruded from the head outlet in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Extruder 2 Head 3 Head exit 4 Extrusion die 5 Extrusion port 6 Guide member 7 Hydraulic cylinder 8 Mandrel 9 Port metal fitting 10 Unvulcanized rubber tape 11 Inner rubber layer 12 Mandrel center shaft 13 Unvulcanized rubber A General diameter part B Expanded diameter Part C Mandrel moving direction E Overlapping part

Claims (4)

An extrusion die is attached to a head of an extruder, and unvulcanized rubber is extruded into a tape shape from a slit-like extrusion port formed in the extrusion die, wherein the extrusion die is a head outlet surface. It is provided so as to be rotatable on the top, and the overlapping portion between the head outlet and the extrusion port is changed by rotating the extrusion die on the head outlet surface , and the width of the rubber tape extruded from the extrusion port is adjusted. An extrusion apparatus characterized by that. An extrusion die provided with a slit-like extrusion port is overlaid without any gap on the head outlet of an extruder that extrudes unvulcanized rubber, and when extruding unvulcanized rubber tape from the extrusion port , in rotatably provided to vary the overlap between the head outlet and the extrusion port by rotating the extrusion die while extruding an unvulcanized rubber tape on the head exit surface, the rubber tape width extruded from the extrusion port A method for producing an unvulcanized rubber tape, characterized by adjusting. Made of unvulcanized rubber by spirally winding it on a mandrel with an enlarged diameter part with the unvulcanized rubber tape extruded from the slit-shaped extrusion port of the extrusion die attached to the head outlet of the extruder A method of forming a cylindrical body, wherein the extrusion die is provided so as to be relatively movable along the head exit surface, and is extruded from the extrusion port by changing an overlapping portion between the head exit and the extrusion port. When the unvulcanized rubber tape is wound around the mandrel and the unvulcanized rubber tape is wound around the enlarged diameter portion, the extrusion die is moved along the head outlet surface. When adjusting the width of the rubber tape to be relatively narrow by moving the unvulcanized rubber tape around a portion other than the enlarged diameter portion, the width of the rubber tape By adjusting to be wider, the method of forming the unvulcanized rubber cylindrical body, characterized by a substantially constant outer diameter over the entire length. The unvulcanized rubber cylindrical body is a inner rubber layer constituting the pumping tube squeeze pump, non of claim 3, wherein the expansion diameter is one that was formed by the armored cap member to the mandrel Method for forming a vulcanized rubber cylinder.

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