JP2009101554A - Apparatus and method for manufacturing hollow molding - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an apparatus for manufacturing a hollow molding by which the hollow molding can be suitably manufactured without reducing productivity by suppressing damage due to steam generated during heating molding. <P>SOLUTION: The manufacturing apparatus of the hollow molding has a molding mold 2 which has a cavity 20 inside, a core material 3 which is inserted in the cavity 20, a molding raw material supply means 5 which supplies a molding raw material in the cavity 20 and further has a core material rotating mechanism 6 which rotates the core material 3 around its axis. In the manufacturing method using the manufacturing apparatus, the core material 3 is inserted in the cavity 20 and further the molding raw material 100 is charged therein. The core material 3 is rotated under this condition and the molding raw material 100 is molded by heating while performing steam drainage through a minute clearance produced between the core material 3 and the molding raw material 100. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a hollow molded body, in particular, a manufacturing apparatus and a manufacturing method for a hollow molded body suitable for a casting mold or structure (hereinafter, also referred to as a mold).

  When casting a hollow casting in a general casting manufacturing method, a core is formed with foundry sand, the core is set in a main mold, molten metal is cast, and the mold is opened after cooling. After demolding the casting, the core is disintegrated and removed to obtain the desired casting.

  By the way, since the core is shaped by curing casting sand obtained by adding a binder to normal sand, there is a problem that a decomposition gas such as amine is generated during casting. Moreover, since it was fragile, when it set to the main type | mold, or when kelen was mounted | worn, the point which was easy to break at the time of pouring was a subject. Furthermore, when sand is reused, a regeneration process is required. However, there is a problem that waste such as dust is generated during the regeneration process.

  The applicant has proposed the technique described in Patent Document 1 below. In this technique, a mold or the like used for casting is formed of a molded body containing organic fibers, inorganic fibers, and a thermosetting resin. The molded body by this technique is thin and lightweight and excellent in workability as compared with a mold using conventional casting sand. Further, there is no problem that the above-mentioned waste is generated. However, since this molded body is manufactured by papermaking, a technique capable of manufacturing the molded body by a simpler method has been desired. Moreover, in the manufacture by papermaking, it has been difficult to form a complicated shape in which the thickness of the molded body varies greatly.

  On the other hand, Patent Documents 2 and 3 propose techniques for forming a molded body by injection molding a raw material. However, these techniques are suitable from the viewpoint of molding a complicated shape in which the thickness of the molded body changes greatly, but there is no disclosure about the manufacturing technology of the hollow molded body, and it is due to the generation of steam caused by the raw material. The breakage of the hollow molded body could not be suppressed.

JP 2004-181472 A JP-A-11-280000 JP 2003-71897 A

  Accordingly, the present invention has been made in view of the above problems, and a hollow molded body that can be suitably manufactured without reducing the productivity by suppressing damage caused by steam generated during the heat molding. It aims at providing the manufacturing apparatus and manufacturing method of a molded object.

  The present invention is an apparatus for producing a hollow molded body comprising a molding die having a cavity therein, a core material inserted into the cavity, and a molding material supply means for supplying a molding material into the cavity, The object is achieved by providing an apparatus for manufacturing a hollow molded body having a core material rotation mechanism for rotating the core material around an axis of the core material.

  The present invention also relates to a method for manufacturing a hollow molded body using the hollow molded body manufacturing apparatus, wherein the core is inserted into the cavity and filled with the molding raw material. By providing a method for producing a hollow molded body by rotating a material and heat-molding the molding raw material while performing steam venting through a minute gap generated between the core material and the molding raw material. Is achieved.

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing apparatus and manufacturing method of a hollow molded object which can suppress the damage by the vapor | steam which generate | occur | produces at the time of the thermoforming, and can be manufactured suitably are provided.

Hereinafter, the present invention will be described based on preferred embodiments thereof.
First, the manufacturing apparatus of the hollow molded object of this invention is demonstrated, referring drawings based on the preferable embodiment.

  FIGS. 1-6 is a schematic diagram of one Embodiment of the manufacturing apparatus (henceforth only a manufacturing apparatus) of the hollow molded object of this invention. In these drawings, reference numeral 1 is a manufacturing apparatus, 10 is a hollow molded body (hereinafter also simply referred to as a molded body), and 100 is a raw material for molding (prepared by adding a dispersion medium to a composition for manufacturing a molded body described later). Raw material).

  As shown in FIG. 1, the manufacturing apparatus 1 includes a molding die 2 having a cavity 20 therein, a core 3 inserted into the cavity 20 of the molding die 2, and a gate of the molding die 2 (hereinafter also referred to as a gate hole). 21) Opening / closing means 4 of 21, a forming raw material supply means 5 for supplying a forming raw material into the cavity 20, and a core material rotating mechanism 6 for rotating the core material 3 around the axis of the core material 3. Yes.

  The mold 2 is composed of a pair of split molds 2A and 2B. By combining these split molds, the mold 2 has a cavity 20 formed therein, and a gate hole (gate) 21 leading to the cavity 20 and an entrance / exit 22 of the core material 3 are formed. The formation surface of the cavity 20 formed by the inner surface of each split mold corresponds to the outer shape of the molded body 10. In the split mold 2 </ b> B, a forming raw material inlet 23 leading to the gate hole 21 is formed. The split mold is made of a metal such as an aluminum alloy or stainless steel. The mold 2 is attached to a platen of mold clamping means (not shown), and is opened and closed in the vertical direction. Each split mold is heated to a predetermined temperature by a heating means (not shown).

  As shown in FIGS. 1 and 3, the cross section of the distal end portion 30 of the core material 3 has a form that gradually narrows in the insertion direction of the core material 3. The ridgeline 31 of the tip 30 may be a curve or a straight line, but the core material 3 in the illustrated example has a rod-like shape having a tapered portion 32 (the ridgeline 31 is a straight line) at the tip 30. . The outer surface of the core material 3 corresponds to the shape of the inner surface of the hollow portion of the molded body 10. The core material 3 is driven back and forth (in the left-right direction in FIG. 1) by driving means (not shown), and is put into and out of the cavity 20 through the entrance / exit 22 of the mold 2.

  The gate opening / closing means 4 includes a gate pin 40 that slides in the gate hole 21. The gate pin 40 is driven back and forth (left and right direction in FIG. 1) by a driving means (not shown), and the tip portion slides inside the gate hole 21 of the mold 2.

  The molding material supply means 5 is constituted by a so-called fluid pressure cylinder / piston unit. The molding material supply means 5 includes a cylinder 50 in which the molding material is accommodated, a piston 51 that slides in the cylinder 50, and a nozzle 52 that discharges the molding material pressed by the piston 51. The forming raw material supply means 5 is configured such that when the nozzle 52 is inserted into the forming raw material inlet 23 and a fluid such as pressurized air is supplied into the cylinder 50, the piston 51 rises, The forming raw material 100 is supplied to the gate hole 21 through the nozzle 52.

  The core material rotation mechanism 6 includes a rotation drive unit 60 provided with a motor (not shown) therein, a rotation drive shaft 61 that is rotationally driven by the motor, and a connection unit 62 that connects the rotation drive shaft 61 and the core material 3. And. When the motor is rotated, the rotation drive shaft 61 and the core material 3 connected thereto rotate integrally, and the core material 3 rotates around the axis. The rotation drive unit 60, the rotation drive shaft 61, and the coupling unit 62 are integrally driven by the drive means (not shown) in the insertion direction of the core material 3 (left and right direction in FIG. 1), thereby the core material. 3 is put into and out of the cavity 20 through the inlet / outlet 22. The connecting portion 62 is a portion where the rotary drive shaft 61 and the core material 3 are connected by a known connecting means, and various means capable of connecting both can be adopted as the connecting means. For example, flange portions projecting to the periphery are provided at each of the end portions of the rotary drive shaft 61 and the core material 3, and the flange portions are coupled to each other by bolts, adhesive, welding, or the like. It is possible to provide a recessed portion into which the end portion of 3 can be fitted, an engaging portion that can be fixed by sandwiching the end portion of the core material 3 or pressing from the periphery.

  As shown in FIG. 4, the core material rotating mechanism 6 inserts the core material 3 to a predetermined position in the cavity, and rotates the core material 3 in a state where the movement of the core material 3 in the insertion direction is stopped. In addition, as shown in FIG. 3, it is also possible to rotate the core material 3 being advanced toward the predetermined position. Furthermore, it is possible to move the core material 3 backward from the predetermined position in the left direction in FIG. 3 while rotating the core material 3.

  The manufacturing apparatus 1 includes a control means (not shown) provided with a sequencer that operates the molding die 2, the core material 3, the gate opening / closing means 4, the molding raw material supply means 5, and the core material rotating mechanism 6 according to the procedure described later. ).

  Next, referring to FIG. 1 to FIG. 6, based on the embodiment in which the manufacturing method of the hollow molded body of the present invention is applied to the manufacturing method of the hollow core used for casting using the manufacturing apparatus 1. While explaining.

  In the method for producing a hollow molded body of the present embodiment, first, a molding raw material is prepared. In the preparation of the forming raw material, inorganic powder is a main component, and inorganic fibers, a thermosetting resin, and a water-soluble binder are mixed in advance by a dry method. When the thermally expandable particles are included, they are included at the time of this dry mixing. And these mixtures (composition for molded object manufacture) are disperse | distributed to a dispersion medium, and it knead | mixes with a kneader, and prepares a shaping | molding raw material in dough shape. Here, having inorganic powder as a main component means that the inorganic powder is the largest in mass ratio among all components contained in the molded body.

  Here, preparing the forming raw material in a dough shape means that the powder, the fiber composition, and the dispersion medium are kneaded gently, and the powder, the fiber composition, and the dispersion medium are easily separated while having fluidity. It means to prepare in the state without.

  Examples of the dispersion medium include water, a solvent such as ethanol and methanol, and an aqueous dispersion medium such as a mixed system thereof. Water is particularly preferable from the viewpoints of molding stability, stability of the quality of the molded body, cost, ease of handling, and the like.

  Examples of the inorganic powder include graphite (eg, scale-like graphite), obsidian, mica, talc, mullite, silica, magnesia, and the like. One or more inorganic powders can be selected and used. From the viewpoint of moldability and cost, it is preferable to use graphite.

  The inorganic fiber mainly forms a skeleton of a molded body, and maintains its shape without being burned by the heat of molten metal during casting, for example. Examples of the inorganic fibers include artificial mineral fibers such as carbon fibers and rock wool, ceramic fibers, and natural mineral fibers. One or two or more inorganic fibers can be selected and used. Among these, it is preferable to use pitch-based or polyacrylonitrile (PAN) -based carbon fibers having high strength even at high temperatures from the viewpoint of effectively suppressing shrinkage associated with carbonization of the thermosetting resin.

  The inorganic fiber preferably has an average fiber length of 0.5 to 15 mm, particularly 1 to 8 mm, from the viewpoint of moldability and uniformity of a mold or the like.

  The thermosetting resin is necessary for maintaining the normal temperature strength and hot strength of the molded body, improving the surface properties of the molded body, and improving the surface roughness of the casting when the molded body is used as a mold. Is an essential ingredient. Examples of the thermosetting resin include a phenol resin, an epoxy resin, and a furan resin. Among these, in particular, there is little generation of combustible gas, there is a combustion suppressing effect, the residual carbon ratio after pyrolysis (carbonization) is as high as 25% or more, and a carbonized film is formed when the molded body is used as a mold. It is preferable to use a phenol resin from the viewpoint that a good casting surface can be obtained. As the phenol resin, a novolak phenol resin that requires a curing agent or a resol type phenol resin that does not require a curing agent is used. The said thermosetting resin can select and use 1 type, or 2 or more types.

  Examples of the water-soluble binder include thickening polysaccharides, polyvinyl alcohol, and polyethylene glycol. Examples of the polysaccharide include gum agents such as xanthan gum, tamarind gum, gellan gum, guar gum, locust bean gum and tara gum, cellulose derivatives such as carboxymethyl cellulose and hydroxyethyl cellulose, carrageenan, pullulan, pectin, alginic acid and agar. Among these polysaccharides, non-natural products such as cellulose derivatives and chemically modified products such as carboxymethyl cellulose are used in a small amount of the water-soluble binder in the composition for producing molded products, rather than natural products such as agar. It is favorable from the viewpoint of exhibiting performance.

  In the composition for manufacturing a molded body, the mixing ratio (mass ratio) of each component is based on the total mass of the inorganic powder, the inorganic fiber, the thermosetting resin, and the water-soluble binder (solid content). Inorganic powder / inorganic fiber / thermosetting resin / water-soluble binder (solid content) = 40 to 90/1 to 20/1 to 30/1 to 10 (mass ratio) is preferable, and 50 to 85/2 16/2 to 25/1 to 5 (mass ratio) is more preferable, and 50 to 85/2 to 16/2 to 20/1 to 5 (mass ratio) is more preferable. (However, the sum of the mass ratios is 100.)

  When the blending ratio of the inorganic powder is within the above range, the shape retention at the time of casting and the surface property of the molded product are good, and the releasability after molding is also suitable. When the blending ratio of the inorganic fibers is within the above range, moldability and shape retention during casting are good. When the blending ratio of the thermosetting resin is within the above range, moldability, shape retention after casting, and surface smoothness are good. When the blending ratio of the water-soluble binder is within the above range, when the molding raw material is filled in the molding die, the molding raw material can be filled with good fluidity, and the moldability of the molded body is improved. .

  When heat-expandable particles are included in the forming raw material, the heat-expandable particles are preferably microcapsules in which an expansion agent that expands by vaporization is encapsulated in the shell wall of a thermoplastic resin. When the microcapsule is heated at 80 to 200 ° C., the diameter preferably expands to 3 to 5 times, the volume preferably expands to 50 to 100 times, and the average particle diameter before expansion is preferably 5 to 80 μm, more preferably Particles of 20-50 μm are preferred. When the expansion of the thermally expandable particles is within such a range, the effect of addition can be sufficiently obtained while suppressing the adverse effect on the molding accuracy due to the expansion. The thermally expandable particles preferably have an average diameter before expansion of 5 to 80 μm, more preferably 20 to 50 μm.

  Examples of the thermoplastic resin constituting the shell wall of the microcapsule include polystyrene, polyethylene, polypropylene, polyacrylonitrile, acrylonitrile-vinylidene chloride copolymer, ethylene-vinyl acetate copolymer, or combinations thereof. Examples of the expanding agent contained in the shell wall include low-boiling organic solvents such as propane, butane, pentane, isobutane, and petroleum ether.

  The thermally expandable particles preferably include 0.5 to 10% (% by mass) with respect to the total mass of the inorganic powder, the inorganic fiber, the thermosetting resin, and the water-soluble binder. It is more preferable to contain 1 to 5% (mass%). When the thermally expandable particles are contained in such a range, the molding raw material is filled in the details of the mold by expansion, and the shape of the mold can be faithfully transferred, and the effect of addition can be sufficiently obtained. Moreover, in the case of the said range, since a large amount of thermally expansible particles are not included, overexpansion can be prevented and an extra cooling time is not required, so that high productivity can be maintained.

  In addition to the components described above, other components such as a colorant, a release agent, and colloidal silica can be added to the molded body of the present embodiment at an appropriate ratio. Moreover, the molded object of this embodiment can contain a tree fiber in the range which does not exert a bad influence on the effect. Examples of the organic fiber include paper fiber (pulp fiber), fibrillated synthetic fiber, and regenerated fiber (for example, rayon fiber). One or two or more organic fibers can be selected and used. Paper fiber is preferable from the viewpoints of moldability, strength after drying, and cost.

Next, as shown in FIG. 1, the mold 2 is clamped and the core material 3 and the gate pin 40 are set. The core material 3 is set so that the front end portion 31 is positioned at the entrance / exit 22 of the mold 2.
The temperature of the mold at this time is preferably 120 to 250 ° C. in consideration of the evaporation of the dispersion medium, the curing rate of the thermosetting resin, the expansion rate of the thermally expandable particles, the burning of the forming raw material, and the like.
Then, as shown in FIG. 2, the molding material 100 is filled into the molding die 2 while being pressurized from the molding material inlet 23 by raising the piston 51 of the molding material supply means 5. When air is used for the pressurized fluid of the forming raw material supply means 5, the air pressure is preferably 0.5 to 3 MPa. Further, the filling pressure of the forming raw material into the mold 2 changes while filling, but the maximum filling pressure is equal to the air pressure.

Next, as shown in FIG. 3, the gate pin 40 is moved forward by the driving means so that the cavity 20 is sealed.
Then, as shown in FIG. 3, while the core material 3 is rotated by the core material rotation mechanism 6, the core material 3 is advanced in the direction of insertion into the cavity 20. As shown in FIG. 4, the core material 3 is inserted to a predetermined position set in advance, and stops moving in the front-rear direction (left-right direction in FIG. 4) at the predetermined position.
Then, heat forming for a predetermined time is performed. The rotation of the core material 3 is continued during the heat forming. Steam generated from the forming raw material 100 through a minute gap (not shown) generated between the core material 3 and the forming raw material 100 by performing the heat forming of the forming raw material 100 while rotating the core material 3. Can be efficiently released to the outside of the mold 2. More specifically, the steam that has passed through the minute gap generated between the core material 3 and the forming raw material 100 passes through the gap between the outer peripheral surface 33 of the core material 3 and the inlet / outlet port 22, so that Released to the outside.
Thereby, the damage of the molded object 10 by rapid deaeration can be suppressed efficiently. The core material 3 is preferably rotated at least when the forming raw material 100 changes from a fluidized state to a non-fluidized state (solidified state).

The rotation speed of the core material 3 is preferably 10 to 1000 rpm, particularly 200 to 800 rpm. Further, the steam can escape between the outer peripheral surface 33 of the core material 3 and the inlet / outlet port 22, but from the viewpoint of forming a gap that prevents the molding material in a fluid state from leaking, the outer diameter of the core material 3 The difference from the inner diameter of the inner peripheral surface of the entrance / exit 22 is preferably 10 to 500 μm , more preferably 30 to 200 μm . In addition, the outer peripheral surface of the core material 3 and the inner peripheral surface of the entrance / exit 22 in this embodiment are circular in cross section.

Next, although the core material 3 is retracted from the predetermined position shown in FIG. 4, the core material 3 is kept rotating during the retraction.
Further, at the time of the retreat, as shown in FIG. 5, the drawing out of the core material 3 is stopped when the tapered portion 32 is applied to the entrance / exit 22. In this state, further steam removal is performed through the gap between the tapered portion 32 and the inner peripheral surface of the entrance / exit 22. Thereby, the damage of the molded object 10 by rapid deaeration can be suppressed more effectively.

  The steam is generated because the molding material contains the dispersion medium, but even if a gas other than the dispersion medium vapor is generated, the core material 3 is rotated as described above, and during the pressure molding. By performing the vapor removal, the gas can be discharged from the mold. As a gas other than the vapor of the dispersion medium, when a phenol resin is used as the thermosetting resin, formalin gas, free phenol gas, ammonia gas, etc. are generated, and further from the thermally expandable particles to the particles. Hydrocarbon gas and the like inside the microcapsules used are generated.

  As described above, the drawing of the core material 3 is stopped at one end and the steam is released. Then, the molded body is dried by continuing heating for a predetermined time. And as shown in FIG. 6, the gate pin 40 is retracted, the shaping | molding die 2 is opened, and the molded object 10 is taken out. The molded body 10 is post-cooled and subjected to post-processing such as trimming, chemical application, and reheating as necessary after completion of cooling.

  In the method for manufacturing a hollow molded body according to the present embodiment, the molding material 100 is heat-molded while the core material 3 is rotated. Therefore, steam is efficiently discharged to the outside through a minute gap between the core material 3 and the molding material 100. It can escape well, and the molded body can be manufactured at high speed while suppressing damage to the molded body due to steam explosion.

  Moreover, when the core material 3 is retracted, steam is removed through the gap between the inner periphery of the inlet / outlet 22 and the tapered portion 32, and then the molded body 10 is continuously heated and dried, so that molding by steam explosion or the like is performed. Damage to the body can be prevented more reliably, and a molded body without damage can be produced at a higher speed.

  Further, since the core material 3 is inserted into the cavity 20 filled with the forming raw material 100 while the core material 3 is rotated, the core material 3 is prevented from being inserted into the cavity 20 in a bent state. In addition, it is possible to prevent unevenness in thickness around the core material 3 from occurring.

  FIG. 7 is a schematic view of a molded body produced in this way. The front end 101 of the molded body 10 is closed and the rear end 102 is open. Moreover, the molded object 10 has a part where an outer diameter becomes thick, and in this embodiment, the outer diameter of the rear-end part 102 is formed thicker than another part.

  Moreover, when the molded object 10 is manufactured from the shaping | molding raw material containing water, 5% or less is preferable and the moisture content before using of this molded object (before using for casting) is preferable, and 2% or less is more preferable. . The lower the moisture content, the lower the amount of gas generated due to thermal decomposition (carbonization) of the thermosetting resin during casting.

  Further, the molded body 10 is mainly composed of inorganic powder, contains inorganic fibers, a thermosetting resin, and a water-soluble binder, is lightweight, has high normal temperature strength, and uses kelen or the like. Excellent handling when used as a child. Moreover, since there is little generation | occurrence | production of the gas accompanying thermal decomposition at the time of use, the bad influence on an environment can be restrained low. In addition, since the dimensional accuracy is high and the hot strength is high, a highly accurate casting can be stably manufactured. In particular, when heat-expandable particles are included, since it is a molded body with high molding accuracy in every detail, a casting with higher accuracy can be manufactured. Moreover, since the inside is hollow, the gas generated during casting can be efficiently discharged from the hollow portion to the outside, and it is lighter. After use, it can be easily made fine by blasting, etc. Also excellent for later handling.

  The present invention is not limited to the above-described embodiment, and can be modified as appropriate without departing from the spirit of the present invention.

For example, instead of inserting the core material 3 into the cavity 20 filled with the forming raw material 100 while rotating, the core material 3 is inserted into the cavity 20 before the molding raw material 100 is filled, While the core material 3 is rotated, the forming raw material 100 can be pressurized and filled into the cavity 20. Also in this case, by rotating the core material 3, the core material 3 is prevented from being bent in the cavity 20, and a high-quality hollow molded body whose thickness is controlled with high accuracy is obtained.
In addition, even when the forming raw material 100 is filled in the cavity 20 in the state where the core material 3 is inserted, the core material 3 is rotated to generate minute amounts generated between the core material 3 and the forming raw material 100. By performing the heat forming of the forming raw material 100 while removing the steam through the gap, damage to the formed body due to steam explosion or the like can be suppressed, and a formed body without damage can be manufactured at high speed.

  Moreover, the core material 3 and the rotational drive shaft 61 may be integrally formed. The core material 3 may be driven by other than a motor.

Moreover, in the said embodiment, although the cross section of the front-end | tip part of a core material was made into the form (form which has a taper part in a front-end | tip part) that narrows gradually toward the insertion direction of this core material, Instead of such a form, the cross-section of the entrance / exit of the core material can be gradually narrowed toward the insertion direction of the core material, and both the cross-section of the tip of the core material and the cross-section of the entrance / exit of the core material Can be gradually narrowed toward the insertion direction of the core material.
Furthermore, the core member does not have to have a configuration in which the cross-section of the tip portion gradually narrows in the insertion direction of the core member.

  In addition to the core used for casting as in the above-described embodiment, the hollow molded body manufacturing apparatus and manufacturing method of the present invention include a mold (main mold), a runner, a hot water stop, a receiving port, a gate, a gate bottom, It is suitable for the use of structures such as cough, degassing, frying, and hot water, and other incidental structures. Moreover, it can apply also to uses other than the casting field | area which requires heat resistance, and can make it a thing with high shaping | molding precision over the detail of the shape according to the use.

Further, the manufacturing apparatus and the manufacturing method of the present invention are the same as in the embodiment described above, in which the inorganic powder, the inorganic fiber, the thermosetting resin, the water-soluble binder (solid content), and the thermally expandable particles. Although it is suitable for the manufacture of a hollow molded body using a molding raw material containing, it can also be applied to the manufacture of a hollow molded body using other molding raw materials.
For example, the present invention can also be applied to the production of a molded body using a mixture of organic fiber and starch kneaded with water as a dispersion medium.

It is a fragmentary sectional view which shows typically one Embodiment of the manufacturing apparatus of the hollow molded object of this invention. It is a fragmentary sectional view which shows typically the supply process of the shaping | molding raw material in one Embodiment of the manufacturing method of the hollow molded object of this invention using the manufacturing apparatus. It is a fragmentary sectional view which shows typically the insertion process of the core material in one Embodiment of the manufacturing method of the hollow molded object of this invention using the manufacturing apparatus. It is a fragmentary sectional view which shows typically the formation process in one Embodiment of the manufacturing method of the hollow molded object of this invention using the manufacturing apparatus. It is a fragmentary sectional view which shows typically the heat drying process in one Embodiment of the manufacturing method of the hollow molded object of this invention using the manufacturing apparatus. It is a fragmentary sectional view which shows typically the demolding process in one Embodiment of the manufacturing method of the hollow molded object of this invention using the manufacturing apparatus. It is a half sectional view showing one embodiment of the hollow fabrication object manufactured by the manufacturing method of the hollow fabrication object of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Manufacturing apparatus of molded object 2 Mold 2A, 2B Split mold 20 Cavity 21 Gate hole (gate)
22 Entrance / Exit 3 Core Material 4 Gate Opening / Closing Means 40 Gate Pin 5 Molding Raw Material Supplying Means 50 Cylinder 51 Piston 52 Nozzle 6 Core Material Rotating Mechanism 60 Rotation Drive Unit 61 Rotation Drive Shaft 62 Connection Unit 10 Molded Body

Claims (5)

An apparatus for producing a hollow molded body comprising a molding die having a cavity therein, a core material inserted into the cavity, and a molding material supply means for supplying a molding material into the cavity,
An apparatus for manufacturing a hollow molded body having a core material rotation mechanism for rotating the core material about an axis of the core material.   2. The core material rotation mechanism according to claim 1, wherein the core material in a state where the core material is inserted to a predetermined position in the gap is rotatable, and the core material being advanced toward the predetermined position is also rotatable. Equipment for producing hollow molded bodies. A method for producing a hollow molded body using the hollow molded body production apparatus according to claim 1,
The core material is rotated in a state where the core material is inserted into the cavity and the molding material is filled, and steam is released through a minute gap generated between the core material and the molding material. A process for producing a hollow molded body, wherein the molding raw material is thermoformed while performing.   The manufacturing method of the hollow molded object of Claim 3 which inserts the said core material in the said cavity with which the said shaping | molding raw material was filled, rotating this core material.   The manufacturing method of the hollow molded object of Claim 3 which fills the said shaping | molding raw material, rotating this core material in the said cavity in which the said core material was inserted.

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