JP2007069494A - Blow molding machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a blow molding machine constituted so as to facilitate the adjustment of bottom burr cutting-off height corresponding to the height of a blow molded article and capable of easily cutting off bottom burr without damaging the blow molded article. <P>SOLUTION: The blow molding machine is equipped with a drive device 40 for allowing a grasping body 20 for grasping the blow molded article after blow molding to approach/separate in a vertical direction with respect to bottom burr cutting-off jigs 51 and 52 and the drive device 40 for moving the grasping body 20 in the approach/separation direction with respect to the bottom burr cutting-off jigs is provided on the side of the grasping body 20. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention is a hollow that can adjust the height position of a bottom beam with respect to a jig for cutting off a bottom beam that is a resin surplus portion at the bottom generated when blow molding a hollow molded product made of a synthetic resin. The present invention relates to a molding apparatus.

  A conventional general hollow molding apparatus is a closed molding in which a thermoplastic resin is heated and melted and is continuously extruded from a die using a screw, and compressed air is blown through a blowing nozzle into an extruded parison. A blower for expanding in a mold and a transport mechanism for blown hollow molded products are provided.

  The occurrence of bottom flash in hollow molding is caused by introducing the parison into the molding die so that the lower part of the hollow molding product has a predetermined shape, and protruding into the molding die. This is because when the mold is clamped and the lower protruding portion of the parison is bitten by the cutting blade at the lower end of the molding die, the protruding portion remains as a surplus portion at the bottom of the hollow molded product.

  Conventionally, cutting and separating the bottom beam is performed by manually transferring the hollow molded product to the molded product gripping body attached to the molding die after removing and removing it from the molding die while leaving the bottom beam at the bottom. A method is used in which a cutting jig for adjusting the height position is operated by an air cylinder or the like, and the bottom beam is cut and separated from the bottom of the hollow molded product.

  However, in the method using the bottom bevel cutting jig having a set of two blades, the height position of the jig varies depending on the product, and the height of the bottom bevel cutting jig of each set of two pieces is different for each product. It was necessary to adjust the size.

  For this reason, an unexpected time may be required to adjust the height dimension of the cutting jig, and it has been demanded to shorten the adjustment time and simplify the adjustment.

  Further, for example, as in the hollow molding machine described in Patent Document 1, the bottom flash remaining in the hollow molded product is clamped by a pair of deburring claws, and is forcibly removed by rotational force and vertical movement. A method has also been proposed.

  Hereinafter, the outline of this method will be described with reference to FIG. 7. The bottom deburring device 113 can be moved up and down on the rotary cylinder 103 attached to the gantry 101 via the bracket 102 and the piston rod of the cylinder 103. The air chuck 104 is pivotably attached to the air chuck 104, and a pair of bottom deburring claws 105 that are attached to the upper portion of the air chuck 104 so as to be openable and closable and grip a bottom beam 117a of the product 117. Below the pair of bottom deburring claws 105, a shooter 110 that discharges the bottom bevel 117a is inclined.

  In the bottom deburring device 113, when a device (not shown) that holds the molded product after blow molding is moved to the bottom deburring position, the rotary cylinder 103 is activated and the bottom deburring claw 105 is raised. The bottom deburring claw 105 is closed by the air chuck to grasp the bottom burr 117a. The bottom deburring claw 105 is rotated from 0 ° to 90 ° by the rotary cylinder 103, and the bottom deburring claw 105 is lowered.

Next, the bottom deburring claw 105 is turned from 90 ° to 0 °, the bottom deburring claw 105 is opened by the air chuck 104 to drop the bottom burr 117a, and the bottom burr 117a is collected by the shooter 110.
JP-A-11-70576

  However, in the above-described method, it is necessary to adjust the rising position of the bottom deburring claw according to the height dimension of each product, and the bottom deburring is performed by jointly using the turning force and the lowering force of the deburring claw. Therefore, an excessive force is applied to the molded product in relation to the device for holding the molded product, and the molded product may be damaged.

  The present invention is intended to solve the problems of such a conventional hollow molding apparatus, so that the height of the gripping body of the hollow molded product can be adjusted, and the hollow molded product is bottomed. The purpose is to adjust the height of the cutting tool according to the height of the hollow molded product by adjusting the height dimension above the cutting jig, and to easily cut the bottom without damaging the molded product. It is what.

  In order to achieve the above object, the present invention provides a hollow molding equipped with a drive device for causing a gripping body for gripping a hollow molded article after blow molding to approach and separate in a vertical direction with respect to a bottom flash cutting jig of the hollow molded article. Device.

  The drive device preferably has a function capable of adjusting the position steplessly using electrical control. In addition, it is preferable from the viewpoint of efficiency that the gripping body is transferred by a product conveying device that moves between a blowing device for blowing compressed air into a parison and a bottom flash cutting jig, for example. As the bottom bevel cutting jig, one using a pair of blade-shaped jigs is desirable from the viewpoint of ease of cutting, but may be any as long as the bottom bevel is cut.

  The second problem-solving means is configured such that the driving device includes a moving rod that supports the gripping body, and an electric motor that moves the moving rod toward and away from the bottom-beam cutting jig in a vertical direction. It is what. As the moving rod, a ball screw is preferable from the viewpoint that the size can be finely adjusted. In addition, the motor is preferably a servo motor from the viewpoint of fine adjustment of the movement of the moving rod, but a linear motor or the like may be used.

  A third problem solving means is that the gripping body is a product restraining pin that inserts a pin tip from the mouth of the hollow molded product and inflates the tip of the pin with a fluid to hold the hollow molded product suspended. It is a configuration. However, the gripping body is not limited to such a configuration, and may be anything as long as it can grip a hollow molded product.

  The operation of the first problem solving means is as follows. That is, after blow molding, the hollow molded product is gripped by the gripping body, and the height position of the gripping body is adjusted by the driving device according to the height of the hollow molded product on the bottom flash cutting jig. There is an effect that the bottom beam remaining at the bottom of the can can be easily cut out by a cutting jig. More specifically, since the bottom position of the product can be adjusted according to the product height, it is not necessary to adjust the position of the bottom cutting tool, and the adjustment work time when changing the setup for each product is shortened. Play.

  The effect | action by the said 2nd problem-solving means has an effect that adjustment of the product bottom part position according to product height can be performed with the simple structure of an operating rod and an electric motor.

  The action of the third problem solving means has been conventionally required to replace the product gripping jig in accordance with the product shape, but it can be shared because it is sufficient to prepare several types of product restraining pins according to the inner diameter of the product mouth portion. There is an effect that the range becomes large and the setup change time for each product can be shortened.

  As described above, the hollow molding apparatus of the present invention can automatically adjust the height dimension of the gripping body of the hollow molded product relative to the bottom flash cutting jig. In other words, the height of the bottom to be cut can be adjusted automatically and easily instead of manually, and the bottom can be easily cut without damaging the molded product.

  Embodiments of a hollow molding apparatus according to the present invention will be described below with reference to the drawings.

  As shown in FIGS. 1 and 2, the hollow molding apparatus includes an extruder (not shown) that melts and extrudes a resin composition as an operating part for molding, a crosshead 1, and a parison cutting device (not shown). , A molding die 2, a blowing device 3, a clamping device 4, a molding die moving device 5, and the like.

  The extruder not shown includes a hopper 7 for charging the resin composition, and a screw not shown for transferring, kneading, melting, and discharging the resin composition inside the extruder.

  As shown in FIG. 1, the crosshead 1 is for multiple heads and is connected to the tip of an extruder. The resin composition melted in the extruder is supplied from the extruder to the crosshead 1, and as shown in FIG. 2, a cylindrical parison P indicated by a two-dot chain line in the figure is formed. Yes.

  The parison cutting device (not shown) cuts the upper part of the cylindrical parison P hanging from the cross head 1 and includes a cutter holder having an electric heating cutter.

  As shown in FIG. 2, the molding die 2 is composed of a pair of split molds 2a and 2b, and a cylindrical parison P is inserted to form a hollow molded product B as shown in FIG. Left and right cavities are formed.

  The molding die 2 is moved by a molding die moving device 5 having an accompanying die moving electric motor, and the positions of the right and left blowing nozzles 8 and 8 of the air blowing device 3 and the position immediately below the multi-head crosshead 1 and 1. It can be reciprocated alternately in the horizontal direction between the positions immediately below. In FIG. 2, reference numeral 6 denotes left and right rails for mold movement that constitute a part of the molding mold moving apparatus 5.

  The blowing device 3 is inserted into the cylindrical parison P and blows compressed air above the left and right cavities of the molding die 2, and therefore a pair of left and right blowing nozzles 8, 8 and these blowing nozzles 8, 8. A blowing nozzle driving device 9 for raising and lowering the nozzle is provided. The blowing nozzle driving device 9 includes a variable speed type blowing device driving motor connected to a control unit (not shown).

  The blowing nozzle 8 is supplied with compressed air from an air source (not shown), and blows air into the cylindrical parison P supplied into the left and right cavities of the molding die 2.

  As shown in FIGS. 1 and 2, the mold clamping device 4 clamps the split molds 2 a and 2 b of the molding die 2, and a pair of horizontal molds arranged at a predetermined interval in a direction parallel to the paper surface. Rails 12 extending in the direction, a front platen 10 and a rear platen 11 provided on the rails 12 so as to be movable at predetermined intervals, and inserted through the platens 10, 11, and these platens are inserted into the parting line of the molding die 2. The left and right reverse lead ball screws 13 are moved in synchronism with the approaching / separating direction, the convex engagement portions 14 provided on the left and right sides of the platens 10 and 11, and the concave engagement portions for grasping the corresponding convex engagement portions. Located on the back side of the rear platen 11, the stop portion 15, the ball screw 16 coupled to the concave locking portion 15 so that the concave locking portion 15 can be pulled when the convex locking portion 14 is gripped. Left and right reverse leads A platen moving motor 17 connected to Lumpur screw 13, and a motor (not shown) is a servo motor for driving the ball screw 16 located on the rear side of the rear platen 11. The front platen 10 is detachably attached with the split mold 2a, and the rear platen 11 is detachably attached with the split mold 2b.

  Each of the left and right ball screws 16 is provided with pulleys 18 and 18 via a thrust bearing (not shown), and these pulleys 18 and 18 are connected to an electric motor (not shown) via an endless belt 19 and a speed reducer 25. ing.

  The product holder (not shown) grips the hollow molded product blow-molded by the blow nozzles 8 and 8 when the mold 2 is closed by inserting the parison P suspended from the cross head 1. In the gripping state, the blowing nozzles 8 and 8 are lifted so as to be detached from the hollow molded product. After the molding die 2 again moves directly below the blowing nozzle 8, as shown in FIGS. 3 to 6, the product restraining pin 20 that is a gripping body for the hollow molded product is lowered, and the hollow molded product B is suspended and supported. Then, after the mold is opened, it is removed from the blowing line and transferred from the product holder to the bottom flash cutting device 50 by the product conveying device 30 that reciprocates in the horizontal direction.

  As shown in FIG. 6, the product restraining pin 20 has a hollow molded product B in which a cylindrical rubber hollow body 20a at the tip of the pin is inserted, and the hollow body 20a is inflated annularly by air injection. It is brought into contact with the inner surface of the mouth part of B and is held in the form of lifting from the molded product. The product restraining pin 20 is coupled to the air tube 21 supported in the vertical direction by the pin support bar 41.

  As shown in FIGS. 4 to 6, the drive device 40 that adjusts the position of the product restraining pin 20 to move up and down includes left and right pin support bars 41, holding arms 42 that support the respective pin support bars 41, and A ball screw 43 that is coupled to the holding arm 42 and moves integrally therewith, and a servo motor 44 that is driven up and down while rotating the ball screw 43.

  The ball screw 43 is rotated by the drive of the servo motor 44, and following the rotation, guides 42 a and 42 b provided on the left and right holding arms 42 are guided by the guide rail 45, and the product restraining pin 20 is moved to the upper limit stopper 46. And the lower limit stopper 47 move in the vertical direction.

  In FIG. 6, the holding arm 42, the air tube 21, and the product restraining pin 20 indicated by a two-dot chain line indicate a standby position, and the holding arm 42, the air tube 21 and the product restraining pin 20 indicated by a solid line are hollow molded. The position for cutting off the bottom of the product B is shown. 3 and 6, the guide rail 45 shown in FIGS. 4 and 5 is omitted in order to clarify the configuration of the ball screw 43.

  The product conveyance device 30 includes a guide rail 31 that extends in the horizontal direction so that the drive device 40 itself can be guided in the horizontal direction, a timing belt 32 that moves the drive device 40 along the guide rail 31, and a motor that drives the timing belt 32. 33.

  The bottom beam cutting device 50 includes a set of two bottom beam cutting jigs 51 and 52, stands 53 and 54 that respectively support the jigs 51 and 52, and guides for making these stands approach and separate from each other. The rails 55, 56 and the stands 53, 54 are attached to the bearing rails 57, 58 that slide on the guide rails 55, 56 by bearings, and the racks 59, 60 as mechanisms for moving the stands 53, 54 closer to or away from each other. A gear pinion 61 between these racks and a cylinder 62 for moving the cutting jig 51 toward and away from the cutting jig 52 are provided. The racks 59 and 60 are moved toward and away from each other in the horizontal direction by rotation of a gear pinion 61 driven by a motor (not shown).

  Each of the bottom beam cutting jigs 51 and 52 has irregularly shaped blades which are cut in a shearing manner when the blades intersect each other. Further, in order to fix and hold the hollow molded product B when the bottom beam is cut off, a pair of left and right upper fasteners 63 and 64 and lower fasteners 65 and 66 are attached to the stands 53 and 54 so as to extend horizontally. Yes.

  The bottom beam B1 cut by the pair of cutting jigs 51 and 52 falls on the shooter 67 and is accommodated in the hopper 68, and is taken out of the molding apparatus by a belt (not shown) below the hopper.

  Next, the operation of the hollow molding apparatus will be described. First, as shown in FIGS. 1 and 2, the resin is suspended from the multi-head crosshead 1 to form the left and right cylindrical parisons P in the lateral direction in FIG. Then, these parisons P are inserted into the left and right cavities of the molding die 2, and then compressed air is blown into the parison P from the blowing nozzles 8 and 8 corresponding to these parisons P, and these parisons P are molded. A bottle which is a hollow molded product B as shown in FIGS. 3 to 5 is formed by blow molding which swells until it coincides with the two cavities 2c and 2d.

  When the molding die 2 is closed, the upper part of the parison P is cut by a parison cutting device (not shown), and the die (not shown) of the molding die and the blowing nozzle 8 introduced into the parison B are used. And shearing by a cutting sleeve. This sheared portion becomes the upper beam. On the other hand, a bottom beam B1 as shown in FIG.

  After the mold 2 is opened, the hollow molded product B is suspended from the blow nozzle 8 together with the upper beam attached to the tip thereof and is held by a product holder (not shown). After the gripping, the blowing nozzle 8 rises and the upper beam is detached from the blowing nozzle and falls by a dropping plate (not shown). The fallen beam is placed on the mouth of the hollow molded product B and is transported together with the hollow molded product B in the subsequent steps. However, in FIGS. When the illustration of the upper beam is omitted, the explanation of the elimination method is also omitted.

  Next, the product restraining pin 20 is inserted in such a manner that the hollow body 20a at the tip of the pin is inserted into the mouth of the hollow molded product B, air is introduced into the hollow body 20a to be inflated, and the hollow molded product B is lifted from the inside. Meanwhile, the product holder releases the grip of the hollow molded product B.

  The product carrying device 30 moves to the bottom cutting process of the next step while supporting the product restraining pin 20. Then, the servo motor 44 is driven above the pair of bottom bevel cutting jigs 51 and 52, and the product restraining pin 20 is lowered together with the holding arm 42 and the pin support bar 41 according to the downward rotation of the ball screw 43, so that a hollow molded product is obtained. The bottom edge B1 of B is positioned between the cutting jigs 51 and 52.

  Thereafter, the gear pinion 61 is rotated to move the racks 59 and 60 to each other, the stands 53 and 54 are brought close to each other, and the hollow molded product B is held by the upper fasteners 63 and 64 and the lower fasteners 65 and 66. To do. Then, the pair of cutting jigs 51, 52 are brought close to each other by driving the cylinder 62, and the bottom beam B 1 is sheared and the cut bottom beam B 1 is removed to the outside through the shooter 67 and the hopper 68.

  The hollow molded product B from which the bottom beam B1 has been removed, after releasing the gripping force by the upper stage fasteners 63 and 64 and the lower stage fasteners 65 and 66, drives the servo motor 44 again and follows the upward rotation of the ball screw 43 to hold arm The product restraining pin 20 is raised together with 42 and the pin support bar 41. Next, the product conveyance device 30 is driven to move the hollow molded product B out of the molding device.

  As described above, according to the present embodiment, it is possible to easily adjust the height dimension of the bottom beam cutting jig for surely removing the bottom beam.

It is a front view of the hollow molding apparatus which shows embodiment of this invention. It is a side view of the hollow shaping | molding apparatus shown in FIG. It is a front view which shows a product restraint pin drive device and a bottom bezel cutting device. It is a perspective view which shows the product restraint pin drive device and bottom flash cutting device shown in FIG. It is the perspective view which looked at the product restraint pin drive device and bottom flash cutting device shown in FIG. 3 from another direction. It is an enlarged front view which shows the product restraint pin drive device shown in FIG. It is a front view which shows the conventional bottom flash cutting device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 20 ... Product restraint pin 30 ... Product conveyance apparatus 31 ... Guide rail 32 ... Timing belt 33 ... Drive motor 40 ... Drive apparatus 43 ... Ball screw 44 ... Servo motor 50 ... Bottom flash cutting device 51, 52 ... Bottom flash cutting jig B ... Hollow molding B1 ... Bottom

Claims (3)

A hollow molding apparatus comprising a drive device for causing a gripping body that grips a hollow molded article after blow molding to approach and separate in a vertical direction with respect to a bottom flash cutting jig of the hollow molded article. 2. The hollow according to claim 1, wherein the driving device includes a moving rod that supports the gripping body and an electric motor that moves the moving rod toward and away from the bottom beam cutting jig in a vertical direction. Molding equipment. 3. The product restraining pin, wherein the gripping body is a product restraining pin that inserts a pin tip from a mouth portion of the hollow molded article and inflates the pin tip with a fluid to hold the hollow molded article in a suspended state. The hollow molding apparatus as described.

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