JP6293814B2 - Screw element removal jig, removal device and removal method - Google Patents

Description

  The present invention relates to a removal tool, a removal device and a removal method for removing a screw element from a screw shaft in a segment type screw of an extruder mainly used in a process for handling a thermoplastic resin.

  In general, the two screws in the twin screw extruder used mainly for the thermoplastic resin mixing process or devolatilization process take a segment system in which the screw elements are finely divided in the axial direction. By recombining various segment type screw elements, it is possible to realize screw configurations suitable for various processes. When changing the screw configuration, it is necessary to once remove the screw element from the screw shaft. When the screw element is removed from the cylinder (barrel) after the thermoplastic resin mixing process, the surface of the screw element is covered with the molten resin. The molten resin on the surface is removed with a wire brush or the like, but the screw elements are adhered to each other by the molten resin remaining slightly between the screw elements. For this reason, in order to remove a screw element, it is necessary to apply big force to an axial direction. Moreover, since it is a segment system, a part of molten resin may enter between the gaps between the screw elements and between the screw elements and the screw shaft. In this case, it is necessary to apply a greater force in order to remove the screw element, which increases the difficulty of removal.

  If it is difficult to remove the screw element by hand, the screw element can be beaten with a hammer through a sleeper while being heated with a gas burner, or the screw element can be beaten directly with a soft lead hammer. is there. However, since these methods apply an impact load oblique to the axial direction to the screw element, there is a concern that the screw shaft may be bent or the like in a small screw shaft of a small machine. In either case, the screw element may be deformed or damaged depending on how the hammer is applied, the position where the hammer is applied, and the strength with which the hammer is applied.

  Patent Documents 1 and 2 disclose a jig having a holding member of an upper and lower split system. The gripping member disclosed in Patent Document 1 has a pocket in which a flight of a screw element is accommodated. The gripping member disclosed in Patent Document 2 has a gripping surface having a shape that follows the outer surface shape of the screw element. By sandwiching the screw element from above and below with the gripping member, the outer surface of the screw element can be gripped over the entire circumference. The screw element can be removed from the screw shaft by applying an axial load to the screw element gripped by the gripping member.

Japanese Patent No. 3929366 JP 2011-51314 A

  The gripping members described in Patent Documents 1 and 2 are integrated members having a gripping surface simulating the shape of the outer surface of the screw element. Since a large contact area can be ensured between the screw element and the gripping member, the force applied to the screw element is dispersed, and the possibility of damaging the screw element and the screw shaft is reduced. However, a dedicated jig is required for each screw element, and enormous costs and time are required for manufacturing the jig.

  It is an object of the present invention to provide a screw element removal jig and a removal method that can secure a large contact area between a screw element and a gripping member and that are easy to manufacture.

The screw element removal jig of the present invention is a gripping member that surrounds and grips the screw element attached to the screw shaft of the extruder in the circumferential direction, and is laminated along the axial direction of the screw element , each of which is a screw. A plurality of thin plates having a thickness less than half of the outer diameter of the element , each thin plate being divided in the circumferential direction of the screw element, and a hole through which the screw element penetrates through the cooperation of the divided portions And a restraining means for restraining the plurality of thin plates in the axial direction. The inner edge portion that defines the hole of each thin plate faces the screw element in the axial direction.

The screw element removing method according to the present invention includes a gripping member that surrounds the screw element in a circumferential direction around the screw element attached to the screw shaft of the extruder, and an axial force of the screw element on the gripping member. And removing the screw element from the screw shaft while holding the screw element with the holding member. The gripping member has a plurality of axially constrained thin plates that are stacked along the axial direction, each having a thickness that is half or less of the outer diameter of the screw element , and each thin plate is in the circumferential direction of the screw element A plurality of divided portions cooperate to form a hole through which the screw element passes. The inner edge portion that defines the hole of each thin plate faces the screw element in the axial direction.

  According to these inventions, the gripping member has a plurality of thin plates stacked along the axial direction. The plurality of thin plates are constrained in the axial direction and are substantially integrated. Moreover, since the inner edge part which defines the hole of each thin plate opposes a screw element, a some thin plate contact | abuts to a screw element when the force of an axial direction is applied. For this reason, the large contact area of a screw element and a holding member is securable. By appropriately combining a plurality of thin plates according to the shape of the screw element, a gripping member having a desired shape can be easily configured. Moreover, since the thin plate can be manufactured from a general-purpose thin steel plate, the manufacturing cost and manufacturing period of the gripping member can be reduced.

  ADVANTAGE OF THE INVENTION According to this invention, the large contact area can be ensured between a screw element and a holding member, and the removal tool and removal method of a screw element with easy manufacture can be provided.

It is a schematic diagram which shows the structure of the screw of a segment system. It is a conceptual diagram of the removal apparatus of the screw element which concerns on one Embodiment of this invention. It is the top view and side view of a thin plate which are used for the removal apparatus shown in FIG. It is detail drawing of a holding member. It is a top view of the thin board in various axial positions. It is a conceptual diagram which shows the mounting method of a holding member. It is the top view and side view of a thin board of a reference example.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a schematic diagram showing a configuration of a segment type screw to which the present invention is applied. The screw 1 of the present embodiment is used in a twin-screw extruder used for a thermoplastic resin mixing process or a devolatilization process. The screw 1 has a screw shaft 2 connected to a rotary drive device (not shown), and a plurality of screw elements 3 attached to the screw shaft 2 via spline joints (not shown). The screw element 3 includes a flight 15 that projects in a radial direction and winds spirally. The plurality of screw elements 3 includes a full flight type screw element, a kneading disc type screw element, and the like. These screw elements 3 are combined according to the process in the twin-screw extruder and attached to the screw shaft 2. However, the present invention can also be applied to a screw of a multi-screw extruder or a single-screw extruder having three or more screws. The illustrated screw 1 has a two-wing structure in which two flights 15 are spirally wound, but the structure of the screw is not limited to this.

  FIG. 2 shows a conceptual diagram of a screw element removal device. FIG. 3A is a plan view of a thin plate constituting the gripping member, and FIG. 3B is a side view of the thin plate. FIG. 4 shows the gripping member in more detail. 4A shows a gripping member viewed from the same direction as FIG. 2, and FIG. 4B shows a cross-sectional view viewed from the direction A in FIG. 2, that is, rotated 90 degrees with respect to FIG. 4A. . FIG. 4C is a detailed view of a portion A in FIG.

  Referring to FIG. 2, the detaching device 4 includes a detaching jig 5, and a pressurizing means 6 that applies a force in the axial direction X of the screw 1 to the detaching jig 5 and removes the screw element 3 from the screw shaft 2. .

  The removal jig 5 has a plurality of thin plates 7 and a restraining means 8 for restraining the plurality of thin plates 7 in the axial direction X. The thin plate 7 is divided in the circumferential direction Y of the screw element 3. The thin plate 7 of the present embodiment is divided into two equal parts in the circumferential direction Y of the screw element 3. Hereinafter, each part of the thin plate 7 divided into two is referred to as an upper half plate 7a and a lower half plate 7b. Since the thin plate 7 is equally divided in the circumferential direction Y, the shape and configuration of the upper half plate 7a and the lower half plate 7b can be made the same, and the manufacturing time and cost of the thin plate 7 are reduced. The number of divisions of the thin plate 7 is not limited to this, and may be three divisions, four divisions, or the like. Since the thin plate 7 can be formed by processing a general thin plate steel plate, it is inexpensive and has a short production time. The thin plate 7, that is, the combination of the upper half plate 7a and the lower half plate 7b has a circular outer edge portion 7c and a substantially oval inner edge portion 7d as a whole. The thickness of the thin plate 7 is preferably less than half of the outer diameter of the screw element 3. The number of thin plates 7 depends on the lead of the screw element 3 (axial length equal to one flight) and the thickness of the thin plate 7, and is selected from a range of several to several hundreds.

  The restraining means 8 restrains the plurality of thin plates 7 stacked around the screw element 3 in the axial direction X to form a gripping member 9 that grips the screw element 3. The restraining means 8 includes a pair of fixing plates 10 that restrain the plurality of thin plates 7 from both sides in the axial direction X, and a fastener 11 that fastens the pair of fixing plates 10 and the plurality of thin plates 7. The fastener 11 includes a bolt 11a and a nut 11b. The fixed plate 10 is composed of an upper half fixed plate 10 a and a lower half fixed plate 10 b which are equally divided into the circumferential direction Y of the screw element 3 in the same manner as the thin plate 7. Each of the upper half fixed plate 10a and the lower half fixed plate 10b has a semicircular portion 12a adjacent to the thin plate 7 and a flange portion 12b protruding in the axial direction X from the semicircular portion 12a. The upper half fixing plate 10a and the lower half fixing plate 10b are fixed to each other by passing bolts through through holes provided in the respective flange portions 12b and fastening them with nuts.

  4 (a) and 4 (b), the plurality of upper half plates 7a are stacked around the upper half circumference of the screw element 3 along the axial direction X of the screw element 3, and the upper half plate is formed on both sides of the axial direction X. It is sandwiched between the fixed plates 10a. Similarly, the same number of lower half plates 7b as the upper half plate 7a are stacked around the lower half periphery of the screw element 3 along the axial direction X of the screw element 3, and the lower half fixing plate 10b on both sides of the axial direction X. It is sandwiched between. The upper half plate 7a and the lower half plate 7b are not fixed to each other.

  As shown in FIG. 3, a pair of upper half fixing plates 10 a and a plurality of upper half plates 7 a are provided with three through holes 13 at the same position in the circumferential direction Y and the radial direction Z. Bolts 11a are inserted into the holes 13 and fastened with nuts 11b. Similarly, a pair of lower half fixing plates 10b and a plurality of lower half plates 7b are provided with three through holes 13 at the same position in the circumferential direction Y and the radial direction Z. 11a is inserted and fastened with a nut 11b. Accordingly, the plurality of upper half plates 7a are firmly fixed between the fixed plates 10a and are substantially integrated. Similarly, the plurality of lower half plates 7b are firmly fixed between the fixed plates 10b and are substantially integrated.

  As shown in FIG. 3, a hole 14 through which the screw element 3 penetrates is formed between the upper half plate 7a and the lower half plate 7b opposite to the upper half plate 7a. That is, the inner edge portion 7d of the upper half plate 7a and the inner edge portion 7d of the lower half plate 7b cooperate to form the hole 14 of the thin plate 7. Here, the upper half plate 7a and the lower half plate 7b may be in contact with each other, but may be separated from each other. Even when the upper half plate 7a and the lower half plate 7b are separated from each other, the imaginary line connecting the inner edge portion 7d of the upper half plate 7a and the inner edge portion 7d of the lower half plate 7b is assumed, and the hole is conceived. Can do. In the present invention, holes defined by such discontinuous lines are also included in the holes 14.

  Since the screw 1 has a two-blade structure, the cross section orthogonal to the axial direction X of the screw element 3 is substantially oval at an arbitrary position in the axial direction X. For this reason, the hole 14 has a substantially oval shape that receives the cross-sectional shape of the screw element 3. Further, since the two flights 15 extend spirally, the substantially oval cross section of the screw 1 rotates as the position of the cross section advances in the axial direction X. In other words, the screw cross section continuously changes in the axial direction X, and the long axis 14a of the hole 14 is at a different angular position in the circumferential direction Y with respect to the through hole 13 according to the axial position. That is, the rotation angle θ of the long axis 14a of the hole 14 is slightly shifted in the circumferential direction Y with respect to the through hole 13 according to the position in the axial direction, and takes a different value for each thin plate 7. 5 (a-1) to (a-5) show the upper half plate 7a at different axial positions, and FIGS. 5 (b-1) to (b-5) show the lower half at different axial positions. The rotation angle θ of the hole 14 is shown for the plate 7b. 5 (a-1) and FIG. 5 (b-1), FIG. 5 (a-2), FIG. 5 (b-2) and the like are respectively the upper half plate 7a and the lower half in the same axial position. A plate 7b is shown.

  As shown in FIG. 4C, a gap 16 is formed between the inner edge 7 d or hole 14 of the thin plate 7 and the screw element 3. Since the through-hole 13 is at the same angular position in all the thin plates 7, if there is no gap 16, the thin plate 7 is specified so that the rotation angle θ of the hole 14 matches the rotation angle of the center line of the flight 15 of the screw element 3. It cannot be arranged other than the axial position. When the gap 16 is present, the thin plate 7 can be disposed even at a position slightly deviated in the axial direction X from a specific axial position, so that workability is improved.

  Referring to FIG. 2, the pressurizing means 6 is a cylindrical hammer 6. The cylindrical hammer 6 has a cylindrical portion 17 through which the screw 1 passes and a flange 18 protruding from the cylindrical portion 17. Instead of the flange 18, a rod-shaped member protruding from the cylindrical portion 17 may be provided. The cylindrical hammer 6 can move in the axial direction X along the screw element 3. The cylindrical hammer 6 can be moved in the axial direction X by pushing the flange 18 or striking the flange 18. Alternatively, the cylindrical hammer 6 may be moved in the axial direction X using a jack.

  Next, a method for removing the screw element 3 will be described.

  As shown in FIG. 6, first, a plurality of upper half plates 7a are stacked, and upper half fixing plates 10a are provided on both sides. At this time, the through holes 13 of the plurality of upper half plates 7a and the through holes 13 of the upper half fixed plate 10a are aligned. Next, the bolt 11a is passed through the through hole 13 and fastened with the nut 11b to form the upper laminate 18a. The upper laminated body 18 a is disposed on the screw element 3 from above the screw element 3. Similarly, a plurality of lower half plates 7b are laminated to form a lower laminate 18b provided with lower half fixing plates 10b on both sides. The lower laminated body 18 b is disposed on the screw element 3 from below the screw element 3. Next, the upper half fixing plate 10 a and the lower half fixing plate 10 b are fixed with bolts 19 and nuts 20. Thereby, the gripping member 9 that covers the screw element 3 in the circumferential direction Y and grips the screw element 3 is formed.

  Since the upper laminated body 18 a and the lower laminated body 18 b are mounted from above and below the screw element 3, the upper half plate 7 a and the lower half plate 7 b are connected to the flight 15 depending on the central axis of the flight 15 and the rotation angle θ of the hole 14. have a finger in the pie. FIG. 3 shows the hole 14 at the rotation angle θ shown in FIGS. 5 (a-4) and (b-4). Since the center axis of the flight 15 is greatly rotated clockwise, the edge of the hole 14 hits the flight 15 in the shape of the hole 14 shown by the broken line, and the upper half plate 7a and the lower half plate 7b are arranged at predetermined positions. I can't. For this reason, the inner edge portion 7d of the thin plate 7 shown in FIG. 3 extends vertically from the dividing surface 7e of the thin plate 7 as indicated by a solid line, and an extension portion 14b of the hole 14 is formed by the vertical inner edge portion 7d. Has been. As a result, when the upper half plate 7a is lowered from the upper side in the figure, the vertical inner edge portion 7d of the hole 14 descends along the rightmost portion of the flight 15 so that the interference between the upper half plate 7a and the flight 15 occurs. Can be avoided. The same applies to the lower half plate 7b. On the other hand, when the rotation angle θ of the hole 14 is small as shown in FIGS. 5A-1 and 5A-2, interference between the upper half plate 7a or the lower half plate 7b and the flight 15 does not occur. It is not necessary to provide the extended portion 14b. That is, the shape of the hole 14 may be a shape indicated by a broken line. In this way, by extending the holes 14 of some of the thin plates 7 in the Z-axis direction, when the upper laminated body 18a and the lower laminated body 18b are mounted from above and below, all the upper half plates 7a and the lower The half plate 7 b can be attached to the screw element 3 without interfering with the flight 15.

  Next, the cylindrical hammer 6 is passed through the screw 1 and the gripping member 9 is beaten in the axial direction X with the cylindrical hammer 6. At this time, the cylindrical hammer 6 may be beaten with another hammer. The gripping member 9 located at the position shown in FIG. 4C moves in the direction in which the force F acts, and comes into contact with the slope of the flight 15 of the screw element 3 as shown in FIG. Ideally, all the thin plates 7 abut on the slope of the flight 15, but only some of the thin plates 7 may abut on the slope of the flight 15. In this way, the gripping member 9 exerts a force in the axial direction X on the screw element 3. Thus, the screw element 3 can be moved along the screw shaft 2 and removed from the screw shaft 2. In order for the gripping member 9 to come into contact with the slope of the flight 15 of the screw element 3, the inner edge 7 d of the thin plate 7 needs to face the flight 15 of the screw element 3 in the axial direction X. The inner edge 7d of the thin plate 7 and the gap 16 between the screw elements 3 are set so as to satisfy this condition. In the present embodiment, the inner edge portion 7d is parallel to the axial direction X. However, as is apparent from the above description, the inner edge portion 7d is in contact with the slope of the flight 15 of the screw element 3 at least at one point in the axial direction X. As long as it can touch, the shape is not limited. The shape of the inner edge 7d may be, for example, a shape along the outer surface of the screw element 3 or a rounded shape.

  As described above, in this embodiment, since the hole 14 of the thin plate 7 is formed in a shape simulating the outer shape of the screw element 3 at each position in the axial direction, each thin plate 7 is a flight of the screw 1. Contact 15 slopes. For this reason, a large contact area between the gripping member and the screw element can be secured, the gripping efficiency of the screw element 3 is increased, and the screw element 3 can be easily pulled out. Furthermore, since the external force applied to the screw element 3 is dispersed, the load on the surface of the screw element 3 is reduced and damage is less likely to occur. Since the load in the axial direction X can be applied to the screw element 3 uniformly in the circumferential direction Y through the gripping member 9, the screw element 3 can be easily removed. Further, the gripping member 9 composed of the thin plate 7 is highly versatile and can handle gripping and removing of almost any shape of the screw element.

  When removing a kneading disk type screw element having the same screw cross-sectional shape in the axial direction, the rotational angle θ of the hole 14 of each thin plate 7 may be changed in accordance with the axial position. In the case of removing screw elements having different screw cross-sectional shapes in the axial direction, for example, screw elements having irregularities on the surface, the shape of the hole 14 and the rotation angle θ may be changed according to the shape of the screw element. .

(Example)
The above-described gripping member 9 was applied to a screw element of the same size as the screw element for the twin screw extruder TEX54 manufactured by Japan Steel Works, and it was confirmed that the screw element could be gripped satisfactorily. Although the thickness of the gripping member 9 is 2 mm, the thickness is preferably 0.4 mm to 3.2 mm in the case of a screw element for TEX54. If the thin plate 7 is thinner than this, the number of necessary thin plates 7 increases, and the working efficiency is lowered. If the thin plate 7 is thicker than this, a large gap is required to secure a margin for the lead when it is attached to the screw element 3, and there is a possibility that the gripping efficiency is lowered. The gap between the screw element and the hole 14 is set to 0.5 mm in all directions, but in the case of the screw element for TEX54, the gap is preferably set to 0.1 mm to 3.0 mm. The rotation angle θ of the hole 14 may be changed according to the lead of the thin plate 7 and the screw element 3, and in the combination of the thin plate 7 having the thickness of 0.4 mm to 3.2 mm and the screw element for TEX54, 1 It is necessary to change in the range of .78 ° to 42.67 °.

(Reference example)
Instead of the thin plate 7 divided in the circumferential direction, an integrated thin plate 107 with a hole can be used. FIG. 7 shows a plan view of the thin plate 107 with holes of the reference example. When attaching the thin plate 107, the thin plate 107 is fitted into the end portion of the screw 1, and the thin plate 107 is moved in the axial direction X while rotating along the spiral shape of the flight 15. In order to facilitate this operation, the hole 114 of the thin plate 107 has an extended portion 114b expanded in the rotational direction. The same effect can be obtained by securing a large gap between the hole 114 of the thin plate 107 and the screw element 3. The fixing plate is an integrated plate with a hole like the thin plate 107. Similar to the embodiment, several to several hundred thin plates 107 are sequentially attached between a pair of fixing plates, and the fixing plates and the thin plates 107 are fixed with bolts. Thereby, the holding member similar to the embodiment is configured. Thereafter, the screw element 3 can be detached from the screw shaft 2 in the same manner as in the embodiment.

  Since the thin plate 107 of the reference example can be manufactured from a general-purpose thin steel plate as in the embodiment, the manufacturing time and the manufacturing cost are the same. However, since the thin plates 107 are attached one by one, the attachment time becomes longer. The screw element 3 is preferably removed from the screw shaft 2 while the screw is hot. This is because the molten resin is solidified as the temperature of the screw shaft 2 and the screw element 3 decreases due to heat radiation, so that it becomes difficult to remove the screw element 3. As described above, the embodiment can attach the plurality of divided thin plates 7 together with the fixing plates 10 on both sides, so that it does not take time for the attachment.

DESCRIPTION OF SYMBOLS 1 Screw 2 Screw shaft 3 Screw element 4 Removal apparatus 5 Removal jig 6 Pressurizing means 7 Thin plate 7a Upper half plate 7b Lower half plate 7d Inner edge 8 Restriction means 9 Holding member 13 Through-hole 14 Hole
15 flights

Claims (9)

A gripping member that surrounds and grips a screw element attached to a screw shaft of an extruder in the circumferential direction, and is laminated along the axial direction of the screw element, each of which is less than half of the outer diameter of the screw element A gripping member having a plurality of thin plates each having a thickness, each thin plate being divided in the circumferential direction of the screw element, and a plurality of divided portions working together to form a hole through which the screw element passes; ,
Restraining means for restraining the plurality of thin plates in the axial direction;
A screw element removal jig in which an inner edge portion that defines the hole of each thin plate faces the screw element in the axial direction. The removal jig according to claim 1, wherein a gap is formed between the inner edge of the thin plate and the screw element. The detachment according to claim 1 or 2 , wherein the restraining means has a pair of fixing plates that restrain the plurality of thin plates from both sides in the axial direction, and each of the fixing plates is divided in the circumferential direction. Jig. The pair of fixing plates and the plurality of thin plates have through holes through which bolts for fastening the pair of fixing plates and the plurality of thin plates pass,
The hole of the thin plate has a substantially oval shape that accepts a cross-sectional shape orthogonal to the axial direction of the screw element, and the long axis of the hole of the plurality of thin plates is the screw element of each thin plate The removal jig according to claim 3 , wherein the removal jig is located at a different angular position in the circumferential direction with respect to the through hole according to the position in the axial direction. The removal jig according to any one of claims 1 to 4 , wherein the thin plate is divided into two equal parts in the circumferential direction. The removal jig according to claim 5 , wherein the inner edge portion of a part of the thin plates extends perpendicularly from a dividing surface of the thin plates. The removal jig according to any one of claims 1 to 6 ,
A screw element detaching apparatus, comprising: a pressing unit that applies a force in the axial direction to the gripping member and removes the screw element from the screw shaft. Providing a gripping member surrounding the screw element in a circumferential direction around the screw element attached to the screw shaft of the extruder;
Applying a force in the axial direction of the screw element to the gripping member, and removing the screw element from the screw shaft while gripping the screw element with the gripping member,
The gripping member has a plurality of thin plates constrained in the axial direction that are stacked along the axial direction and each has a thickness of half or less of the outer diameter of the screw element. The screw element is divided in the circumferential direction, and a plurality of divided parts cooperate to form a hole through which the screw element passes,
A method of removing a screw element, wherein an inner edge portion defining the hole of each thin plate is opposed to the screw element in the axial direction. Providing the gripping member
Laminating each of the divided portions of the plurality of thin plates to form a plurality of laminates;
The removal method according to claim 8 , comprising arranging the plurality of laminated bodies around the screw element.

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