JP2006335017A - Method and apparatus of extruding strip-like rubber - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To raise pressure of an extruding passage to regular pressure in a short time. <P>SOLUTION: When a screw is rotated in the state that a small through-hole 35 is inter-communicated with the extruding passage, pressure of the extruding passage is rapidly increased even if a die is removed from a main body since raw material rubber in the extruding passage moves while the raw material rubber being squeezed in the small through-hole 35. Then a slide plate 33 is moved to make a large through-hole 34 inter-communicate with the extruding passage, the die is attached to the main body and the strip-like rubber is molded by extruding the raw material rubber through the die. Since the pressure of the extruding passage is rapidly increased in this way, it is possible to raise the pressure of the extruding passage to the regular pressure in a short time. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

    The present invention relates to a method and an apparatus for extruding a band-shaped rubber in which a raw rubber is extruded as a band-shaped rubber through a die.

As a conventional method and apparatus for extruding a belt-shaped rubber, for example, the one described in Patent Document 1 below is known.
JP 9-57816 A

  This consists of a cylinder barrel and an extrusion head, and a main body in which an extrusion passage through which the material rubber passes is formed, and is housed in the extrusion passage of the cylinder barrel and rotates to feed the material rubber in the extrusion passage A screw that is pushed and moved toward the side, and a die that is detachably attached to the tip of the extrusion head and that extrudes the rubber material supplied from the extrusion passage into a predetermined shape as a belt-like rubber.

  And in such an extrusion device, for example, when there is a change in the type of rubber to be extruded, after the extrusion operation is once finished, the base is removed from the main body of the extrusion device and remains in the extrusion passage. Remove the rubber material. Next, while feeding and filling different types of material rubber into the extrusion passage of the main body, the screw is rotated, and the material rubber in the extrusion passage is pressed and moved to the tip side while kneading, and the base is not attached. Extrude from the end of the extrusion passage in the state

  Then, as shown by the solid line in FIG. 3, when such pressure is continued for a certain time T2 and the pressure in the extrusion passage rises to a certain level of pressure P1, the base is attached to the main body and the material rubber is again attached. By rotating the screw while being supplied, the rubber material having a high viscosity in the extrusion passage is extruded through a die to form a rubber band.

    Here, in order to extrude a band-shaped rubber whose specifications are within the specification, that is, a band-shaped rubber usable in the next process, it is necessary to increase the pressure in the extrusion passage to a specified pressure P3. In such a conventional extrusion apparatus, since the raw rubber is extruded from the extrusion passage while the base is removed from the main body at the initial stage of extrusion, the extrusion passage remains in the extrusion passage even if a certain time T2 elapses. This pressure rises only to a certain level P1 which is considerably lower than the specified pressure P3.

  Thereafter, the raw rubber is extruded with the base attached, but since the pressure in the extrusion passage only rises to a certain pressure P1 as described above, the pressure in the extrusion passage is changed from the certain pressure P1 to the specified pressure. It took a long time to rise to P3, and as a result, there was a problem that a long time was required for the pressure in the extrusion passage to rise to the specified pressure P3 from the start of extrusion T1.

  A large amount of the rubber band extruded until the pressure in the extrusion passage reaches the specified pressure P3 (between the start of extrusion T1 and time T5) is out of specification and used in the next step as it is. Since it cannot be performed, it is necessary to recycle the rubber as a raw material rubber, thereby causing a problem that the yield is reduced and a process loss occurs.

  An object of the present invention is to provide a method and an apparatus for extruding a belt-like rubber capable of increasing the pressure in an extrusion passage to a specified pressure in a short time.

    The purpose of the first object is to provide a slide plate that extends across the extrusion passage between the screw and the base when the base is removed from the main body in which the extrusion passage through which the rubber material passes is formed. A process of communicating in the extrusion passage with a small through hole whose opening area is smaller than the opening area of the extrusion passage at the crossing position by moving in the longitudinal direction, and rotating the screw, the rubber material in the extrusion passage is made to pass through the small through hole. A step of rapidly moving the pressure in the extrusion passage on the rear side of the slide plate by moving the pressure toward the front end side while passing, and moving the slide plate in the longitudinal direction to move the slide plate from the small through hole A large through hole which is provided apart in the longitudinal direction and has substantially the same opening area as the opening area of the extrusion passage at the intersection position is communicated with the extrusion passage. A method for extruding a band-shaped rubber comprising a step of attaching a base to the tip of the main body and a step of extruding a material rubber in an extrusion passage through a large through hole and a base by rotating a screw to form a band-shaped rubber of a predetermined shape Can be achieved by

  Secondly, a main body in which an extrusion passage through which raw rubber passes is formed, and a screw that is housed in the extrusion passage of the main body and rotates to press and move the raw rubber in the extrusion passage toward the tip side. A belt-shaped rubber extrusion device, which is detachably attached to the tip of the main body and includes a base for extruding the raw material rubber supplied from the extrusion passage into a predetermined shape as a belt-shaped rubber. A slide plate extending across the extrusion passage between the two is inserted so as to be movable in the longitudinal direction, and a large through-hole having substantially the same opening area as the opening area of the extrusion passage at the intersection position and the large penetration When a small through hole with a smaller opening area than the hole is provided in the longitudinal direction and the base is removed from the main body, the small through hole of the slide plate is connected to the extrusion passage. While rotating the screw, the pressure in the extrusion passage on the rear side of the slide plate is quickly raised, and then the slide plate is moved in the longitudinal direction so that the extrusion passage communicates with the large through hole. Can be achieved by an apparatus for extruding a band-shaped rubber in which the rubber is extruded through the die by rotating the screw and then the band-shaped rubber is formed.

  In this invention, a slide plate extending across the extrusion passage between the screw and the die is inserted into the main body so as to be movable in the longitudinal direction, and substantially the same as the opening area of the extrusion passage at the intersection position. Since the large through-hole having an opening area and the small through-hole having a smaller opening area than the large through-hole are provided apart in the longitudinal direction, the small through-hole of the slide plate is provided even when the base is removed from the main body. If the screw is rotated in a state where the pipe is in communication with the extrusion passage, the material rubber in the extrusion passage will be pressed and moved toward the tip side while being squeezed by the small through-hole, so the rear side from the slide plate The pressure in the extrusion passage increases rapidly.

  As a result, when a certain time has elapsed from the start of extrusion, the pressure in the extrusion passage rises to a pressure considerably higher than the above-described certain pressure. After that, the material rubber is extruded with the base attached, but as mentioned above, the pressure in the extrusion passage rises to a fairly high pressure, so the pressure in the extrusion passage rises from this pressure to the specified pressure in a short time. As a result, the time from the start of extrusion until the pressure in the extrusion passage rises to the specified pressure can be greatly shortened. And when the time from the start of extrusion to reaching the specified pressure is shortened in this way, it is possible to effectively reduce the amount of non-standard band-like rubber, thereby easily improving the yield. In addition, the process loss can be suppressed.

  When the pressure in the extrusion passage rises to a certain level, the base rubber may be attached to the main body and the material rubber may be pushed out. Since the pressure can be increased, the time from the start of extrusion until the pressure in the extrusion passage increases to the specified pressure can be greatly shortened.

In addition, if configured as described in claim 3, it is possible to effectively increase the pressure in the extrusion passage, while eliminating the possibility that it will be difficult for the material rubber to pass through the small through hole. If configured as described in claim 4, it is possible to prevent a foreign matter from being mixed into the belt-like rubber while reducing the manufacturing cost, and if configured as described in claim 5, the structure It is simple and the production cost can be reduced.
According to the sixth aspect of the present invention, since the pressure-increased raw rubber exists up to the extrusion passage near the rear side of the die, the pressure in the extrusion passage is regulated after the extrusion is started. The time until the pressure is reached can be shortened, and if it is configured as described in claim 7, it can be easily manufactured.

Embodiment 1 of the present invention will be described below with reference to the drawings.
1 and 2, 11 is an extrusion device for extruding material rubber 12 kneaded by, for example, a Banbury mixer while heating and kneading again. This extrusion device 11 is a cylinder barrel having a substantially cylindrical shape extending in the front-rear direction. 13, and a passage 14 through which the material rubber 12 passes is formed inside the cylinder barrel 13. Further, a rotatable screw 15 is accommodated in the passage 14 of the cylinder barrel 13, and the screw 15 is rotated by receiving a driving force from a driving motor (not shown) so that the material in the passage 14 is rotated. The rubber 12 is pressed and moved toward the front (front end side) while being heated and kneaded.

  Reference numeral 18 denotes an extrusion head attached to the front end (front end) of the cylinder barrel 13, and a passage 19 communicating with the passage 14 is formed in the extrusion head 18, so that the screw 15 The material rubber 12 sent out from the passage 14 passes toward the front end side, and this passage 19 becomes lower in the vertical direction and wider as it goes to the front end. Is opened in a substantially rectangular cross section at the tip (front end).

  Here, the passages 14 and 19 described above constitute an extrusion passage 20 through which the material rubber 12 passes. Further, the cylinder barrel 13 and the extrusion head 18 described above constitute a main body 21 in which an extrusion passage 20 is formed. A die holder 25 is detachably attached to the tip (front surface) of the extrusion head 18 (main body 21), and a through passage 26 communicating with the extrusion passage 20 is formed in the die holder 25.

  A base 27 is accommodated in the front end portion of the die holder 25 so as to be able to enter and exit. As a result, the base 27 is detachably attached to the front end of the main body 21 via the die holder 25. The base is formed with a molding opening 28 that communicates with the extrusion passage 20 through the through passage 26 and has a predetermined shape with an opening area smaller than the opening area at the tip of the extrusion passage 20. The material rubber 12 pressed and moved by the screw 15 passes through the extrusion passage 20 and the through passage 26, and is then extruded through the molding opening 28 of the base 27, whereby a belt-like rubber 29 having a rectangular cross section (predetermined shape) is formed. To be molded.

  32 is a through-slit extending in the left-right direction formed in the vicinity of the body 21, more specifically, the boundary between the cylinder barrel 13 and the extrusion head 18, and the central part of the through-slit 32 intersects the extrusion passage 20 at right angles, and Communicate. 33 is a rectangular plate-like slide plate, and this slide plate 33 is inserted into a through slit 32 formed in the main body 21 in the vicinity of the boundary between the cylinder barrel 13 and the extrusion head 18 so as to be movable in the longitudinal direction of the slide plate 33. As a result, the slide plate 33 extends at right angles to the extrusion passage 20 between the screw 15 and the base 27.

  The slide plate 33 is connected to a moving means (not shown), for example, a tip of a piston rod of the cylinder. As a result, when the cylinder is operated and the piston rod is protruded or retracted, the slide plate 33 is moved in the longitudinal direction. Move in the direction. If the slide plate 33 is inserted in the vicinity of the boundary between the cylinder barrel 13 and the extrusion head 18 in this way, the structure can be simplified and the manufacturing cost can be reduced, and the slide plate 33 can be extruded as described above. If the passage 20 intersects at a right angle, the through slit 32 can be formed easily and can be manufactured easily compared to the case where the passage 20 intersects at an angle.

  The slide plate 33 has at least two types of holes having different opening areas, and here, the opening area of the extrusion passage 20 at the position where the slide plate 33 intersects the extrusion passage 20 (intersection position) is substantially the same. There are two types of holes: a large through hole 34 having an area and a small through hole 35 having an opening area smaller than that of the large through hole 34, specifically, a small through hole 35 having an opening area smaller than the opening area at the tip of the extrusion passage 20. The slide plate 33 is provided at a predetermined distance in the longitudinal direction. Then, when the moving means as described above is operated and the slide plate 33 is moved in the longitudinal direction, either the large through hole 34 or the small through hole 35 formed in the slide plate 33 is pushed through the extrusion passage 20. Communicate with.

  Here, the opening area B of the small through-hole 35 is preferably in a range of 1/4 to 3/4 times the opening area A of the large through-hole 34. The reason for this is that if B is less than 1/4 times A, it may be difficult for the rubber material 12 to pass through the small through-hole 35, while B exceeds 3/4 times A. And the pressure difference between the front and rear of the slide plate 33 in the extrusion passage 20 is small, and it becomes impossible to effectively increase the pressure in the extrusion passage 20, specifically, the extrusion passage 20 on the rear side of the slide plate 33. It is.

  36 is a strainer body detachably fitted to the slide plate 33 around the large through-hole 34, and this strainer body 36 has a strainer net 37 that clogs foreign matter mixed in the material rubber 12. The strainer net 37 has a slightly larger overall shape than the opening shape of the extrusion passage 20 at the intersection position. Reference numeral 38 denotes a ring body that holds the strainer net 37 by sandwiching the outer edge portion of the strainer net 37. The inner peripheral surface of the ring body 38 is flush with the inner peripheral surface of the large through hole 34.

  As described above, if a strainer net 37 is provided in at least the large through-hole 34 of the small through-hole 35 and the large through-hole 34 to block foreign matter mixed in the material rubber 12, it is necessary to provide a strainer device separately. As a result, it is possible to prevent a foreign matter from being mixed into the belt-like rubber 29 while reducing the manufacturing cost.

Next, the operation of the first embodiment will be described.
Assume that, for example, the type of rubber to be extruded is changed in the extruding device 11 that extrudes the band-shaped rubber 29 in a state where the large through hole 34 provided in the slide plate 33 communicates with the extruding passage 20. In such a case, first, after the rotation of the screw 15 is stopped and the extrusion operation is once completed, the die holder 25 and the base 27 are removed from the main body 21 (extrusion head 18), and the extrusion passage 20 remains. Remove the rubber material. When the base 27 is removed from the main body 21 in this way, the slide plate 33 is moved in the longitudinal direction of the slide plate 33 by a moving means (not shown), and the large through hole 34 is separated from the extrusion passage 20. At the same time, the small through hole 35 is communicated with the extrusion passage 20.

  Next, at time T1 in FIG. 3, extrusion is started, that is, the material rubber 12 of a different type from the material rubber is supplied and filled into the extrusion passage 20, while the screw 15 is rotated by the drive motor. As a result, the raw rubber 12 in the extrusion passage 20 is heat-mixed and kneaded, and is pressed and moved toward the tip side while passing through the small through hole 35.

  Here, in order to extrude the band-shaped rubber 29 whose specifications are within the specification, that is, the band-shaped rubber 29 usable in the next step, it is necessary to increase the pressure in the extrusion passage 20 to the specified pressure P3. When the raw rubber 12 is extruded from the extrusion passage 20 without passing through the small through-hole 35 with the base 27 removed as in the prior art, even if a certain period of time has elapsed since the start of extrusion, That is, even at time T2, the pressure in the extrusion passage 20 rises only to a certain level P1 that is considerably lower than the specified pressure P3, as shown by the solid line in FIG.

  However, in this embodiment, a slide plate 33 extending perpendicularly to the extrusion passage 20 is inserted into the main body 21 so as to be movable in the longitudinal direction, and the large through hole 34 and the large through hole 34 are inserted into the slide plate 33. Since the small through hole 35 having a smaller opening area is provided in the longitudinal direction, the small through hole 35 communicates with the extrusion passage 20 as described above even when the base 27 is removed from the main body 21. If the screw 15 is rotated in this state, the material rubber 12 in the extrusion passage 20 is pressed and moved toward the tip side while being squeezed by the small through hole 35.

  As a result, the material rubber 12 that has been kneaded by the screw 15 and has increased viscosity stays in the extrusion passage 20 on the rear side of the slide plate 33, and the inside of the extrusion passage 20 on the rear side of the slide plate 33 remains. Pressure rises quickly. As a result, when a certain time elapses from the start of extrusion and reaches time T2, the pressure in the extrusion passage 20 rises to a pressure P2 that is considerably higher than the above-described certain pressure P1, as indicated by a broken line in FIG. Thus, when the pressure rises to P2 at time T2, the rotation of the screw 15 is stopped, and the extrusion of the material rubber 12 is temporarily stopped.

  Thereafter, the slide plate 33 is moved in the longitudinal direction so that the small through hole 35 is separated from the extrusion passage 20, while the large through hole 34 is communicated with the extrusion passage 20, and the die holder is attached to the tip of the main body 21 (extrusion head 18). 25. Install the base 27. When such work is completed and time T3 is reached, the screw 15 is rotated again with the base 27 attached to the main body 21, and the material rubber 12 in the extrusion passage 20 is extruded through the large through hole 34 and the base 27. In this case, the belt-shaped rubber 29 having a predetermined shape is molded. At this time, as described above, the pressure in the extrusion passage 20 once rises to a considerably high pressure P2, so that the pressure in the extrusion passage 20 is defined in a short time from the pressure P2. The pressure can be increased to P3. As a result, the time from the start of extrusion until the pressure in the extrusion passage 20 increases to the specified pressure P3 can be greatly shortened.

  That is, in the prior art, time T5 was required to increase to the specified pressure P3. In this embodiment, however, the pressure in the extrusion passage 20 is increased to the specified pressure P3 when a time T4 shorter than the time T5 has elapsed. Can do it. And when the time from the start of extrusion until reaching the specified pressure P3 is shortened in this way, the amount of non-standard band-like rubber can be effectively reduced, thereby easily improving the yield. And process loss can be suppressed.

  When the pressure in the extrusion passage 20 rises to a certain pressure P1, the base 27 may be attached to the main body 21 to extrude the material rubber 12. In this case, the pressure in the extrusion passage 20 is conventionally increased. Since the pressure P1 can be increased to a certain level in a shorter time, the time from the start of extrusion until the pressure in the extrusion passage 20 increases to the specified pressure P3 can be greatly shortened.

    4 and 5 are views showing Embodiment 2 of the present invention. In this embodiment, the slide plate 33 described in the first embodiment is inserted into a through slit 32 formed between the extrusion head 18 and the die holder 25 in the vicinity of the rear side of the base 27, specifically, immediately after the base 27. is doing. In this way, the slide plate 33 is arranged immediately after the base 27, in other words, to intersect the tip of the extrusion passage 20, and when the base 27 is removed from the main body 21, the slide plate 33 has a rectangular shape. If the screw 15 is rotated in a state where the through hole 35 is in communication with the extrusion passage 20, the material rubber 12 in the extrusion passage 20 is pressed and moved toward the tip side while being squeezed by the small through hole 35. Therefore, the pressure in the extrusion passage 20 on the rear side of the slide plate 33, here, the pressure in almost the entire region in the extrusion passage 20 increases rapidly.

  At this time, since the pressure-increased material rubber 12 exists up to the extrusion passage 20 immediately after the base 27 (near the rear side), the pressure in the extrusion passage 20 reaches the specified pressure P3 after the extrusion is started. Can be shortened. Other configurations and operations are the same as those in the first embodiment.

    In the above-described embodiment, the slide plate 33 is provided with one large and one small through hole 34, 35, but in this embodiment, the slide plate has two large through holes and one small through hole. While providing a hole, a strainer net | network may be provided in each large through-hole, and when one strainer net | network performs the strainer operation | work, you may make it replace | exchange the other strainer net | network. In the above-described embodiment, the strainer net 37 is provided only in the large through hole 34. However, in the present invention, a strainer net may be provided in the small through hole.

  The present invention can be applied to the industrial field of an extrusion apparatus for extruding a strip rubber.

It is front sectional drawing which shows Example 1 of this invention. It is II sectional view taken on the line of FIG. It is a graph which shows the relationship between the pressure in an extrusion channel | path, and time. It is front sectional drawing which shows Example 2 of this invention. It is II-II arrow sectional drawing of FIG.

Explanation of symbols

11 ... Extruder 12 ... Rubber material
13 ... Cylinder barrel 15 ... Screw
18 ... Extrusion head 20 ... Extrusion passage
21… Body 27… Base
29 ... Strip rubber 33 ... Slide plate
34… Large through hole 35… Small through hole
37 ... Strainer net

Claims (7)

    When the base is removed from the main body formed with an extrusion passage through which the rubber material passes, the slide plate extending across the extrusion passage between the screw and the base is moved in the longitudinal direction to A process of communicating a small through hole with an opening area smaller than the opening area of the extrusion passage to the extrusion passage, and rotating the screw to push the raw rubber in the extrusion passage toward the tip while passing through the small through hole A step of quickly increasing the pressure in the extrusion passage on the rear side of the slide plate, and moving the slide plate in the longitudinal direction so that the slide plate is provided away from the small through hole in the longitudinal direction, and The large through hole, which has substantially the same opening area as the extrusion passage at the position, is connected to the extrusion passage, and a base is attached to the tip of the main body. That process and extrusion methods of the strip-shaped rubber characterized by comprising a large through hole material rubber extrusion passage by rotating the screw, extruded through a spinneret, a step of forming a strip-shaped rubber having a predetermined shape.     A main body having an extrusion passage through which the rubber material passes is formed, a screw that is housed in the extrusion passage of the main body and rotates to push the raw rubber in the extrusion passage toward the front end side, and the front end of the main body In a belt rubber extruding device, which is detachably attached to a base and includes a base for extruding a raw rubber supplied from an extrusion passage into a predetermined shape as a strip rubber, an extrusion between the screw and the base is made on the main body. A slide plate extending across the passage is inserted so as to be movable in the longitudinal direction, and a large through hole having an opening area substantially the same as the opening area of the extrusion passage at the intersecting position and an opening area from the large through hole When the small through-hole is provided apart in the longitudinal direction and the base is removed from the main body, do not allow the small through-hole of the slide plate to communicate with the extrusion passage. By rotating the screw, the pressure in the extrusion passage on the rear side of the slide plate is quickly increased, and then the slide plate is moved in the longitudinal direction so that the extrusion passage and the large through-hole communicate with each other. An apparatus for extruding a band-shaped rubber, which is attached to a main body and then extrudes material rubber through the die by rotating a screw to form a band-shaped rubber.     3. An apparatus for extruding a strip-shaped rubber according to claim 2, wherein the opening area of the small through-hole is in the range of 1/4 to 3/4 times the opening area of the large through-hole.     4. A belt rubber extruding device according to claim 2, wherein a strainer net is provided in at least the large through hole of the small through hole and the large through hole to block foreign matter mixed in the raw rubber.     The main body comprises a cylinder barrel in which a screw is housed and an extrusion head attached to the tip of the cylinder barrel, and a slide plate is inserted in the vicinity of the boundary between the cylinder barrel and the extrusion head. 5. An apparatus for extruding a belt-shaped rubber according to any one of 4 above.     The main body is composed of a cylinder barrel in which a screw is stored, and an extrusion head attached to the tip of the cylinder barrel and having a base attached to the tip, and a slide plate is inserted into the extrusion head near the rear side of the base. The extrusion apparatus of the strip | belt-shaped rubber | gum in any one of Claims 2-4.     The belt rubber extrusion device according to any one of claims 2 to 6, wherein the slide plate intersects the extrusion passage at a right angle.

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