JP5904248B1 - Parison holding and cutting device and Harrison holding and cutting method - Google Patents

Abstract

When a parison continuously discharged from a die head is cut in units of supply to a mold, the parison can be surely divided even if the operation of moving the die head upward is omitted. Deters crushing. A parison cutting device (1) includes a restraining chuck (2) that grips the periphery of the parison (P) and restrains the parison (P) discharged from the die head (10), and a cutter (3) that cuts the parison (P) immediately below the restraining chuck (2). . [Selection] Figure 1

Description

The present invention relates to a parison held cutting device and the parison held cutting method for cutting and holding a parison ejected from a die head of the extruder at a feed unit to the mold.

  An extrusion blow molding machine melts a thermoplastic resin by an extruder, discharges the melted resin from the die head of the extruder to form a hollow parison, sandwiches the parison between a pair of blow molds, and blow molds Is a molding machine for forming a hollow body by blowing blow air into a parison sandwiched between two.

  In such an extrusion blow molding machine, in order to continuously produce a molded product, parisons continuously discharged from a die head are sandwiched between molds one after another, and the mold is conveyed at that time. As a method, a vertical rotary type that conveys the mold up and down according to the downward direction of the parison, a shuttle type that sequentially conveys the molds arranged in a horizontal plane perpendicular to the downward direction of the parison to the downward position of the parison And horizontal rotary type are known.

  Here, since the parison is supplied to the mold that is transported in the direction intersecting the descending direction of the parison, the parison that is continuously discharged from the die head is transferred to the mold in systems other than the vertical rotary type. It is necessary to cut in units of supply. Conventionally, the parison is cut by holding the parison discharged from the die head with a mold and cutting with a parison cutter disposed on the mold (see Patent Document 1 below), or the parison with the mold itself. It is made to grab.

JP 2000-43138 A

  In order to cut the parison continuously discharged from the die head, even if the parison is cut using the parison cutter as in the above-mentioned conventional technique, if the cut parison is not immediately retracted to another position, the parison is lowered and cut. A problem arises in that the parisons are rejoined. Conventionally, in order to avoid this, the die head (extruder) is moved upward simultaneously with the parison cutting. However, since it is necessary to operate a heavy object, it is difficult to perform a rapid continuous operation. A problem arises that the cycle cannot be raised.

  In addition, when cutting the parison directly with a mold, when cutting the parison using a parison cutter, the soft hot parison is cut with a sickle-like or hook-like cutter, so the cut ends are crushed. Problems arise. It is desirable that the parison cut-out be opened in order to insert a blow pin or blow nozzle therefrom in a subsequent air blowing process. On the other hand, in the air blowing process, needle-shaped blow needles are inserted into the mold and pierced into the parison, but according to this, needle debris is generated and adhered to the inside of the molded product, and exhaust / cooling The problem of not being able to increase the molding cycle is mixed because of the low efficiency.

  This invention makes it an example of a subject to cope with such a problem. That is, when the parison continuously discharged from the die head is cut in units of supply to the mold, the parison can be reliably divided even if the operation of moving the die head upward is omitted. An object of the present invention is to prevent crushing so that air can be blown from an open cut end.

In order to achieve such an object, a parison holding and cutting apparatus and a parison holding and cutting method according to the present invention have the following configurations.
This is a parison holding and cutting device that holds and cuts the parison discharged vertically downward from the die head of the extruder in units of supply to the mold, and restrains the parison discharged from the die head by holding the periphery of the parison. And a cutter for cutting the parison immediately below the restraining chuck, the restraining chuck restrains the parison discharged from the die head while gripping the periphery of the parison and moving downward, and the cutter Is a parison holding and cutting device for cutting a parison directly below the restraining chuck while moving integrally with the restraining chuck .

A parison holding and cutting method in which a parison discharged vertically downward from a die head of an extruder is cut in units of supply to a mold, wherein a restraining chuck that moves downward grips the periphery of the parison and is below the restraining chuck. After the parison holding means holds the parison of the supply unit on the side, the parison is cut by a cutter that moves integrally with the restraining chuck immediately below the restraining chuck, and the restraining chuck grips the periphery of the parison and moves downward. A parison holding and cutting method characterized in that the parison discharged from the die head is restrained while moving and the cutter cuts the parison directly below the restraining chuck while moving integrally with the restraining chuck .

According to such a parison holding and cutting apparatus and a parison holding and cutting method, when the parison continuously discharged from the die head is cut in units of supply to the mold, the operation of moving the die head upward can be omitted. Can be reliably divided. In addition, it is possible to suppress the crushing of the parison cut and to blow air from the opened cut.

Pas Rison cutting apparatus and explanatory views illustrating a parison cutting method ((a) is explanatory view in a side view, (b) is illustration of a plan view) is. It is an explanatory view showing the form of a cutter path Rison cutting device comprises (a plan view and a sectional view taken along line X-X). Is an explanatory view showing an operation example of the path Rison cutting device. It is explanatory drawing which shows the operation example (example in which a parison holding means is a pick-up chuck) of the parison holding | maintenance cutting device which concerns on embodiment of this invention. It is explanatory drawing which shows the operation example (example in which a parison holding means is a metal mold | die) of the parison holding | maintenance cutting device which concerns on embodiment of this invention. (Examples of (a) is a rack and pinion mechanism, (b) Examples of the crank mechanism) explanatory view showing an example of a gripping and cutting operation mechanism Pas Rison cutting device is. Is (operating state diagram over time) explanatory view showing an operation example of downward movement of the path Rison cutting device. It is an explanatory diagram showing an operation example of downward movement of the path Rison cutting device (performance chart of the restraint chuck).

Hereinafter, embodiments of the present invention will be described with reference to the drawings. A parison holding and cutting device and a parison holding and cutting method according to an embodiment of the present invention include a parison cutting device 1 shown below and a parison holding means 4 described later. As shown in FIG. 1, the parison cutting device 1 cuts a parison P discharged vertically downward from a die head 10 of an extruder by a supply unit Ps to a die (not shown). A cutter 3 is provided. The pair of left and right chuck pieces 2R, 2L of the restraint chuck 2 grips the periphery of the parison P, restrains the parison P discharged from the die head 10, and the cutter 3 holds the parison P directly under the restraint chuck 2. Disconnect. The restraining chuck 2 and the cutter 3 can be integrated, and the distance between the lower surface of the restraining chuck 2 and the upper surface of the cutter 3 is set to 10 mm or less, preferably 1 to 10 mm.

  The pair of chuck pieces 2R, 2L of the restraining chuck 2 have semicircular recesses 2p for maintaining the hollow state of the parison P, as shown in FIGS. By having such a recess 2p, the parison P is gripped only by the restraining chuck 2 while maintaining a state in which air passes through the inside. Further, as shown in FIG. 1B, the restraining chuck 2 has a pair of chuck pieces 2R and 2L that approach and separate along a uniaxial direction in a horizontal plane, and the cutter 3 is a direction orthogonal to the uniaxial direction. Go to and cut the parison P. The cutter 3 can install the heater 3H inside as needed, and can set the temperature of a cutter to temperature (for example, 400-600 degreeC) suitably according to the object resin of Parison P.

  As shown in FIG. 2, the shape of the cutter 3 can be appropriately set to a strip shape (a), a plate-like shape (b), a plate-like flat shape (c), a plate-like guillotine type (d), or the like. The material of the cutter 3 can be selected as appropriate. When the cutter 3 is heated, SUS, Ni alloy or the like that is less deformed during heating can be used. The cutter blade may be provided only on one side and cut by one-way movement, or may be provided on both sides and alternately cut by reciprocating movement.

  According to such a parison cutting device 1, the parison P is gripped by the restraining chuck 2 and the portion immediately below the parison P is cut by the cutter 3, so that reliable cutting is possible and a high quality cut surface can be obtained. The pair of chuck pieces 2R, 2L of the restraint chuck 2 have a recess 2p to form a hole concentric with the center of the parison, and can grip only the periphery of the parison P. Since the cutting is performed in the maintained state, the cut end can be prevented from being crushed (blocked).

  FIG. 3 shows an operation example of the parison cutting device 1. Although the parison cutting device 1 can hold and cut the parison P in a stationary state, the example shown in FIG. 3 performs a cutting operation while holding the parison P and moving downward. In this example, the restraining chuck 2 restrains the parison P discharged from the die head 10 while gripping the periphery of the parison P and moving downward, and the cutter 3 moves together with the restraining chuck 2 while restraining the chuck 2. Cut the parison P directly under

In this way, the parison cutting device 1 performs an operation of moving the die head 10 upward with respect to the parison P continuously discharged from the die head 10 by performing a cutting operation while holding the parison and moving downward. Owing to this, the parison P can be reliably divided by avoiding recombination after cutting. At this time, the parison holding means 4 that the constraining chuck 2 holds the parison P and moves downward in accordance with the movement of the parison cutting device 1 below the cutter 3 holds the parison supply unit Ps. After that, the cutting operation is performed. The parison holding means 4 also moves horizontally while moving downward, and retracts the parison supply unit Ps after cutting from directly below the die head 10.

  As shown in FIG. 4, the parison holding means 4 described above can be configured by a pickup chuck 5 that holds the parison at the upper and lower portions of the supply unit Ps and conveys the parison to the mold 6. The pickup chuck 5 includes an upper chuck 5A composed of a pair of left and right chuck pieces that grasps the upper portion of the supply unit Ps below the cutter 3, and a lower chuck 5B composed of a pair of left and right chuck pieces that grasp the lower portion of the supply unit Ps. Yes. At this time, the distance between the lower surface of the cutter 3 and the upper surface of the upper chuck 5A is preferably set to about 5 to 15 mm. The interval between the upper chuck 5A and the lower chuck 5B is set according to the height of the mold 6 for supplying the parison supply unit Ps so that the parison supply unit Ps can be held on the upper and lower sides of the mold 6. Is set. Each of the pair of chuck pieces of the upper chuck 5A includes a semicircular recess 5p so as to form a hole concentric with the center of the parison. By providing the recess 5p, the parison supply unit Ps can be supplied to the mold 6 while maintaining the state in which the cut end of the parison is opened.

  Further, as shown in FIG. 5, the above-described parison holding means 4 can be constituted by a mold 6. In this case, it is preferable that the upper end portion 6A of the mold 6 holds and restrains the upper portion of the parison supply unit Ps. The distance between the cutter 3 and the upper surface of the mold 6 at this time is set to about 5 to 15 mm.

  FIG. 6 shows an example of a gripping / cutting operation mechanism of the parison cutting device 1. The pair of left and right chuck pieces 2R and 2L of the restraining chuck 2 provided in the parison cutting device 1 are moved toward and away from each other along a uniaxial direction in a horizontal plane by a lead screw 20 as shown in, for example, (a) and (b). Can be driven. The lead screw 20 is provided with screw portions 20R and 20L whose guide directions are opposite to each other.

  In the example shown in (a), the cutter 3 provided in the parison cutting device 1 is supported by a support frame 30 attached to the operation frame 31, and the operation frame 31 is paired with a pair of chuck pieces 2R by a rack and pinion mechanism 32. , 2L reciprocates in a direction orthogonal to the direction in which the two are approaching and separating. In the example shown in (b), the operation frame 31 that supports the cutter 3 reciprocates in a direction perpendicular to the direction in which the pair of chuck pieces 2R and 2L approach and separate by the crank mechanism 33. These mechanism examples are merely examples, and various operation mechanisms can be employed.

  7 and 8 show an example of the downward movement of the parison cutting device 1 (FIG. 7 shows an operation state with respect to time, and FIG. 8 shows an operation diagram of the restraint chuck 2 (2A, 2B). ing.). As shown in FIG. 7, the parison cutting device 1 includes a downward movement unit 7 that moves the restraint chuck 2 and the cutter 3 downward together. Although the parison cutting device 1 provided with the restraint chuck 2 and the cutter 3 is illustrated as two holding the upper and lower sides of the parison P in the same time zone, a plurality of two or more parisons may be provided and sequentially fed out. it can.

  The restraining chuck 2 in the parison cutting device 1 grips the parison P at the first position (I) close to the die head 10 and moves to the second position (II) farther from the die head 10 than the first position (I). . At this time, the other restraining chuck 2 (2B) grips the parison P at the first position (I) before one restraining chuck 2 (2A) reaches the second position (II). The parison holding means 4 holds the parison supply unit Ps while the pair of upper and lower restraint chucks 2A and 2B hold the parison P. At this time, the speed at which the restraining chuck 2A (2B) moves from the first position (I) to the second position (II) is made faster than the descending speed of the parison P discharged from the die head 10, and the parison P is moved to the die head 10. Pull between.

  The downward movement unit 7 operates the individual restraint chucks 2A and 2B that move together with the cutter 3 repeatedly at a predetermined cycle, and always restrains the parison P discharged from the die head 10 to continue its pulling state. Let The downward movement of the restraining chucks 2A and 2B is a movement for restraining the parison P and applying a pull, but the upward movement of the restraining chucks 2A and 2B is as follows. This is a return operation for preparing for the restraint operation.

  7A to 7E show the change in the discharge state of the parison P and the operation of the restraining chuck 2 (2A, 2B) that moves together with the cutter 3 in chronological order. 7 (a) and 7 (b), the restraining chuck 2A moves downward while gripping the parison P, and the restraining chuck 2B moves without gripping the parison P in the reverse direction. . In FIG. 7C, the preceding restraining chuck 2A restrains the parison P, and the succeeding restraining chuck 2B grips the parison P at the first position (I). After the state of FIG. 7C, the parison P is held by the pair of upper and lower restraint chucks 2A and 2B as shown in FIG. 7D, and thus the parison P is held by the restraint chucks 2A and 2B. Is held, the above-described parison holding means 4 performs the operation of holding the parison P, and then the cutting operation by the cutter 3 is performed.

  FIG. 8 is an operation curve of the restraint chucks 2A and 2B shown in FIG. 7, where the horizontal axis is the time T, the vertical axis is the distance Z from the die head 10, the solid line is the operation curve of the restraint chuck 2A, and the broken line is a broken line. Indicates an operation curve of the restraining chuck 2B. Note that the states at times [1] to [5] in FIG. 8 correspond to the states (a) to (e) in FIG.

  In FIG. 8, the restraining chucks 2A and 2B that move integrally with the cutter 3 are moved downward at a constant speed, and from the timing T2 when one restraining chuck 2A (2B) reaches the second position (II). The subsequent restraint chuck 2B (2A) grips the parison P at the first position (I) at the timing T1 that is earlier by the time Ts, and then the two restraint chucks 2A and 2B both hold the parison P for the time Ts. Move while pinching. A part or all of the above-described time Ts is set in a process of holding the parison P by the parison holding means 4 and separating it by the cutter 3 and transporting it to the mold 6.

  Such a parison cutting device 1 can always restrain the parison P discharged from the die head 10 and apply a linear tension by moving the restraining chuck 2 (2A, 2B) downward. As a result, it is possible to suppress uneven thickness due to drawdown of the parison P discharged downward in the vertical direction, and apply appropriate tension that does not change the direction and speed, and the parison is held by the cutter 3 while maintaining this tension state. P can be cut. As a result, the high-quality parison P having high thickness uniformity and excellent molecular orientation can be separated and supplied to the mold 6.

  According to the parison cutting device 1 and the parison cutting method using the parison cutting device 1, the restraining chuck 2 (2A, 2B) moving downward holds the periphery of the parison, and the parison holding means 4 below the restraining chuck 2 After holding the parison of the supply unit Ps, the parison P is cut by the cutter 3 that moves integrally with the restraining chuck 2 immediately below the restraining chuck 2, so that the parison P can be reliably divided and the cut end is It becomes possible to supply to the mold 6 while maintaining the opened state.

  As a result, the operation of moving the die head 10 (extruder) upward can be omitted, and the mold 6 has a good exhaust / cooling efficiency by inserting a blow nozzle or blow pin through the upper opening of the sandwiched parison. A blow process can be performed. As a result, the molding cycle can be increased and high productivity of the molded product can be obtained. In addition, since the step of piercing the blow needle into the parison in the mold can be eliminated, the generation of needle dust can be eliminated and a high-quality molded product can be obtained.

  As described above, the embodiments of the present invention have been described in detail with reference to the drawings. However, the specific configuration is not limited to these embodiments, and the design can be changed without departing from the scope of the present invention. Is included in the present invention. In addition, the above-described embodiments can be combined by utilizing each other's technology as long as there is no particular contradiction or problem in the purpose and configuration.

1: Parison cutting device, 2, 2A, 2B: Restraint chuck, 2p: Recess,
2R, 2L: Chuck piece, 3: Cutter, 4: Parison holding means,
5: Pickup chuck, 5A: Upper chuck, 5B: Lower chuck,
5p: recess, 6: mold,
7: Downward moving part, 10: Die head, P: Parison, Ps: Supply unit

Claims (11)

A parison holding and cutting device for holding and cutting a parison discharged vertically downward from a die head of an extruder by a supply unit to a mold,
A restraint chuck that grips the periphery of the parison and restrains the parison discharged from the die head; and a cutter that cuts the parison directly under the restraint chuck ,
The restraining chuck restrains the parison discharged from the die head while moving downward by gripping the periphery of the parison,
The parison holding and cutting device characterized in that the cutter cuts the parison immediately below the restraining chuck while moving integrally with the restraining chuck . 2. The restraint chuck has a pair of chuck pieces that are close to and separated from each other along a uniaxial direction in the water surface, and the chuck pieces have a concave portion that holds and holds the parison in a hollow state. The parison holding and cutting device as described. The parison holding and cutting device according to claim 2 , wherein the cutter moves in a direction orthogonal to the uniaxial direction to cut the parison. The parison holding and cutting device according to any one of claims 1 to 3, wherein a gap between a lower surface of the restraining chuck and an upper surface of the cutter is set to 10 mm or less. The cutter according to any one of claims 1 to 4, wherein the cutter performs a cutting operation after the restraining chuck grips the parison and the parison holding means holds the supply unit of the parison below the cutter. The parison holding and cutting device according to item 1. The restraining chuck repeats an operation of gripping a parison at a first position close to the die head and moving to a second position farther from the die head than the first position, and one restraining chuck moves to the second position. Before the other, the other restraining chuck grips the parison at the first position, and the parison holding means holds the parison while the pair of restraining chucks grip the parison. The parison holding cutting device according to claim 5. 7. The parison holding and cutting device according to claim 6, wherein a speed at which the restraining chuck moves from the first position to the second position is faster than a descent speed of the parison discharged from the die head. The parison holding and cutting device according to any one of claims 5 to 7, wherein the parison holding means is a mold to which a parison is supplied. The parison holding and cutting device according to any one of claims 5 to 7, wherein the parison holding means is a pickup chuck that holds the parison at the upper and lower parts of the supply unit and conveys the parison to a mold. The pickup chuck includes an upper chuck and a lower chuck made of a pair of left and right chuck pieces, and each of the chuck pieces has a semicircular recess so as to form a hole concentric with the center of the parison. The parison holding and cutting device according to claim 9. A parison holding and cutting method for cutting a parison discharged vertically downward from a die head of an extruder in a unit of supply to a mold,
A downwardly moving restraint chuck grips the periphery of the parison, and a parison holding means holds the parison of the supply unit below the restraint chuck and then moves integrally with the restraint chuck immediately below the restraint chuck Cut the parison with
The restraining chuck restrains the parison discharged from the die head while moving downward by gripping the periphery of the parison,
A parison holding and cutting method , wherein the cutter cuts the parison directly below the restraining chuck while moving integrally with the restraining chuck .

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