JP2009255442A - Die ring structure for blow molding machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable replacement of inner-periphery die rings alone by dividing the die ring into an inner-periphery die ring and an outer-periphery die ring and removably attaching the inner-periphery die ring to the outer-periphery die ring even when replacement is required due to changes of molding conditions and/or change with time. <P>SOLUTION: A die ring structure for blow molding machines includes a die (4) arranged on the outer periphery of the core (3) of the cross head (1) through a resin passage (11), and a die ring (5) freely slidable vertically relative to the outer periphery of the die (4). The die ring (5) is divided into an inner-periphery die ring (30) and an outer-periphery dir ring (31), and the inner-periphery die ring (30) is freely removably attached to the outer-periphery die ring (31). <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a die ring structure for a hollow molding machine, and in particular, by dividing a die ring into an inner peripheral die ring and an outer peripheral die ring, and making the inner peripheral die ring detachable from the outer peripheral die ring, Further, the present invention relates to a novel improvement for easily replacing only the inner peripheral die ring even when replacement or the like is required due to changes over time.

As a conventionally used die ring structure for a hollow molding machine, for example, a configuration similar to the configuration disclosed in Patent Document 1 can be disclosed in FIGS.
That is, what is indicated by reference numeral 1 in FIG. 2 is a crosshead of a well-known hollow molding machine (not shown). A die 4 disposed on the outer peripheral position of the core 3 and a die ring 5 disposed on the outer periphery of the die 4 are disposed concentrically.

  The die ring 5 is held with respect to a ring-shaped die ring holder 6 via mounting bolts 7 and a holding plate 7A. The die ring holder 6 is provided with a die holder fixed to the lower portion of the crosshead 1. Four rods 10 connected to each other through a guide link 9 are connected to the rod 8.

Each of the rods 10 penetrates the holding portion 9a of the guide link 9 so as to be movable up and down, so that the die ring holder 6 and the die ring are inserted through the rod 10 with respect to the guide link 9 in a fixed arrangement. 5 is configured to move up and down simultaneously.
A drive source for moving the rods 10 connected to the die ring holder 6 up and down is not shown, but is configured to be operated by any one of electric, hydraulic and pneumatic actuators.

FIG. 2 is a plan view showing the position of the extruder 1A relative to the crosshead 1. This extruder 1A (in the figure, one extruder is used, but in the case of a multilayer parison, two or three are used. Is supplied to the crosshead 1 and is formed at the lower end of the resin flow path 11 through a cylindrical resin flow path 11 formed between the die 4 and the core 3. It is constituted so that it may be discharged as a cylindrical parison 12 downward from the gap 4a. A heater 20 and a thermocouple 21 are provided on the die ring 5.
Therefore, in the above-described configuration, by sliding the die ring 5 up and down with respect to the fixedly arranged die 4, as is well known, the gap width of the gap 4a between the die 4 and the core 3 becomes variable, and the parison The thickness of 12 can be freely changed in the circumferential direction.
4 shows a side view of FIG. 2, and FIG. 5 shows a bottom view in the direction of arrow B in FIG.

JP 2008-044249 A

Since the conventional die ring structure for a hollow molding machine is configured as described above, the following problems exist.
That is, in the above-described conventional configuration, since the die ring is integrally formed, a material such as brass is employed in relation to sliding with the outer periphery of the flexible die made of the steel, etc., so that it is formed of the steel. When wear and deformation occurs due to sliding with the flexible die, the vertical position is controlled by a precise servo motor, etc., and an error occurs when the wall thickness of the parison is controlled. The surrounding structure to be held had to be disassembled and assembled, and the labor and cost were significant.

  In general, the optimal shape of the inner periphery of the die ring (wall thickness adjustment allowance) varies depending on the shape of the molded product that is hollow-molded using a parison, the type of resin, molding conditions, etc. Depending on the test results, it is often the case that the die ring is removed, added, or newly produced, and each time the die ring needs to be replaced, a great deal of labor is required.

In some cases, a die ring having several kinds of shapes is prepared, and a parison is actually formed to form a cut-and-try method for hollow forming.
Also, for example, when a large drum can is hollow-formed from a parison, it is necessary to make the wall thickness of the parison sufficiently thick at both ends in the longitudinal direction and the other portions sufficiently thin. In order to make it stably, there are many cases where additional machining of the die ring and a part of the shape change are required, and each time, the die ring and its peripheral parts have to be attached and detached.

  A die ring structure for a hollow molding machine according to the present invention includes a die provided at a peripheral position of a core provided at a lower portion of a cross head of the hollow molding machine via a resin flow path, and a vertical slide with respect to the outer periphery of the die. A die ring structure for a hollow molding machine, wherein the die ring is configured to adjust a circumferential thickness of a parison exiting from the resin flow path by sliding the die ring up and down. The inner peripheral die ring is slidably contacted with the outer periphery of the die, and the inner peripheral die ring is detachably provided on the outer peripheral die ring, and The lower surface of the inner peripheral die ring is provided with a recess, the outer peripheral die ring is provided with a screw hole corresponding to the recess, and the screw body provided in the recess is screwed into the screw hole. By A configuration wherein the inner die ring and the outer die ring is attached, also the inner circumferential die ring has a configuration which is screwed through the threaded portion to the outer peripheral die ring.

Since the die ring structure for a hollow molding machine according to the present invention is configured as described above, the following effects can be obtained.
That is, a die provided at the outer peripheral position of the core provided at the lower part of the cross head of the hollow molding machine via a resin flow path, and a die ring that can slide up and down with respect to the outer periphery of the die, In the die ring structure for a hollow molding machine in which the circumferential thickness of the parison exiting from the resin flow path is adjusted by the vertical sliding of the die ring, the die ring is divided into an inner peripheral die ring and an outer peripheral die ring. The inner peripheral die ring is slidably contacted to the outer periphery of the die, and the inner peripheral die ring is detachably provided on the outer peripheral die ring, and only the inner peripheral die ring of the die ring is removed. What is necessary is just to perform necessary processing and the like, and the work is greatly simplified as compared with the conventional whole attachment and detachment, and a minimum amount of labor and time are required.
In addition, the production cost for a new production can be greatly reduced.
In addition, surface treatment and the like are significantly cheaper.
In addition, a crosshead having a conventional structure can be replaced and used.
Further, the die ring can be easily exchanged, and the position adjustment and change of the shape of the die ring can be easily performed.
A recess is provided on the lower surface of the inner peripheral die ring, a screw hole is provided in the outer peripheral die ring corresponding to the recess, and a screw body provided in the recess is screwed into the screw hole. By doing so, the inner peripheral die ring and the outer peripheral die ring are coupled, so that the inner peripheral die ring can be attached and detached very easily.

  The present invention divides the die ring into an inner peripheral die ring and an outer peripheral die ring, and makes the inner peripheral die ring detachable from the outer peripheral die ring, so that only the inner peripheral die ring can be easily changed depending on molding conditions and changes over time. It is an object of the present invention to provide a die-ring structure for a hollow molding machine that can be exchanged.

Hereinafter, preferred embodiments of a die ring structure for a hollow molding machine according to the present invention will be described with reference to the drawings.
The same or equivalent parts as in the conventional example will be described using the same reference numerals, and the configuration of the crosshead itself is the same as in the conventional example, so only the configuration of the die ring 5 that is different from the conventional example in FIGS. 1 will be described, and the configurations of FIGS. 2 to 5 are incorporated in the present invention.

In FIG. 1, the conventional configuration of the die ring 5 and the configuration of the present invention are divided into half sections through a center line P, the left half from the center line P is the conventional configuration, and the right half is the configuration of the present invention.
In the configuration of the present invention of FIG. 1, the die ring 5 that is in sliding contact with the die 4 has a split two-body structure including an inner peripheral die ring 30 and an outer peripheral die ring 31.

The inner peripheral die ring 30 is formed in an L-shaped cross section, and a recess 33 is formed on the lower surface 32 thereof.
The outer peripheral die ring 31 combined with the inner peripheral die ring 30 has a stepped cross section, and a screw hole 35 corresponding to the recess 33 is formed at a substantially central position of the outer peripheral die ring 31. Has been.

  A through hole 34 communicating with the screw hole 35 is formed in the upper portion of the recess 33 of the inner peripheral die ring 30, and a screw body 36 inserted into the recess 33 is inserted into the screw hole 35 via the through hole 34. The inner peripheral die ring 30 and the outer peripheral die ring 31 are integrally connected to each other.

  Accordingly, the inner peripheral die ring 30 and the outer peripheral die ring 31 constituting the die ring 5 having the configuration shown in FIG. 1 are integrated with each other, and only the inner peripheral die ring 30 is detachably attached to the outer peripheral die ring 31. When the die ring 5 is connected to the die ring holder 6 shown in FIG. 2 and only the inner peripheral die ring 30 is removed from the outer peripheral die ring 31, the inner peripheral die ring 30 is simply removed by removing the screw body 36. Can be removed from the outer peripheral die ring 31 very easily.

With the above-described configuration of the present invention, for example, the circumferential thickness of the parison exiting from the discharge outlet of the resin flow path 11 can be adjusted by sliding the die ring 5 in the vertical direction.
Further, as described above, when the die ring 5 is used to discharge the parison 12 from the gap 4a and hang down to form a molded product (not shown) by a hollow molding machine (not shown), the inner peripheral die ring 30 is used. Also in the replacement, processing, correction, etc., the inner peripheral die ring 30 can be easily and reliably removed only by removing the screw body 36.

  In the above-described configuration, the structure for attaching and detaching the inner peripheral die ring 30 with respect to the outer peripheral die ring 31 has been described with respect to the configuration using the screw body 36. By screwing the outer peripheral thread portion formed on the outer periphery of the die ring 30 to the inner peripheral thread portion formed on the inner periphery of the outer peripheral die ring 31, the inner peripheral die ring 30 can be used without using the screw body 36. The attachment / detachment structure can be obtained.

It is a half sectional view of the important section showing the die ring structure for hollow molding machines by the present invention compared with the conventional composition. It is a block diagram with a partial cross section which shows the die ring structure of the conventional crosshead. It is AA sectional drawing of FIG. 2 which shows the conventional crosshead. FIG. 3 is a right side view of FIG. 2. It is a bottom view seen from the arrow B of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Crosshead 2 Parison discharge part 3 Core 4 Die 5 Die ring 6 Die ring holder 30 Inner periphery die ring 31 Outer periphery die ring 32 Lower surface 33 Concave part 34 Through hole 35 Screw hole 36 Screw body

Claims (3)

The die (4) provided via the resin flow path (11) at the outer peripheral position of the core (3) provided at the lower part of the crosshead (1) of the hollow molding machine, and the outer periphery of the die (4) And a die ring (5) that can slide up and down,
In the die ring structure for a hollow molding machine in which the circumferential thickness of the parison (12) exiting from the resin flow path (11) is adjusted by sliding the die ring (5) up and down,
The die ring (5) is divided into an inner peripheral die ring (30) and an outer peripheral die ring (31), and the inner peripheral die ring (30) is in sliding contact with the outer periphery of the die (4), and the inner peripheral die ring A die ring structure for a hollow molding machine, wherein the ring (30) is detachably provided on the outer peripheral die ring (31).   A recess (33) is provided on the lower surface of the inner peripheral die ring (30), and a screw hole (35) is provided in the outer peripheral die ring (31) corresponding to the recess (33). The screw body (36) provided in (33) is screwed into the screw hole (35), whereby the inner peripheral die ring (30) and the outer peripheral die ring (31) are coupled. Item 2. A die ring structure for a hollow molding machine according to Item 1.   The die ring structure for a hollow molding machine according to claim 1, wherein the inner peripheral die ring (30) is screwed to the outer peripheral die ring (31) via a screw portion.

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