JP5462107B2 - Method and apparatus for manufacturing hollow molded article - Google Patents

Description

  According to the present invention, in primary molding, a pair of semi-hollow molded products are formed to have a joining end surface by using a movable mold and a fixed mold that can be closed, and in the secondary molding, the fixing is performed. The joining end surface of one semi-hollow molded product remaining in the mold and the joining end surface of the other semi-hollow molded product remaining in the moving mold are opposed to each other so as to be at a predetermined interval. A heater is inserted between the end faces in a non-contact manner, the joining end faces are melted to retract the heater, and the movable mold is closed with respect to the fixed mold, or a pair of semi-hollow molded products The present invention relates to a method and an apparatus for manufacturing a hollow molded product, in which the end faces are pressed against each other in a mold and the joining end faces are fused.

  Hollow molded articles such as automobile fuel tanks, oil tanks, or buoys are also molded by injection molding. When forming a hollow molded product by injection molding, the primary molding that molds a pair of semi-hollow molded products and the openings of the pair of semi-hollow molded products that have been primary-molded are butted together and joined to the butted outer periphery The secondary molding is performed by injecting a molten resin. According to the molding method using this injection molding machine, a completely sealed hollow molded product can be molded, a hollow molded product with a uniform thickness can be produced, and complex shapes can be dealt with. Furthermore, there is an advantage that each process can be automated and a hollow molded product can be mass-produced. However, some hollow body products may be difficult to manufacture by this molding method. For example, when manufacturing a hollow body product in which the interior is partitioned by ribs or wall surfaces, such as a tank whose interior is divided into a plurality of chambers by a plurality of ribs, it is also necessary to join the rib portions in the secondary molding. However, it is difficult to manufacture with the above molding method. In this molding method, since the molten resin for bonding must be injected for secondary molding, the structure of the injection machine and the mold becomes complicated, and the molding time may be long. Further, if the secondary injection pressure is small, the joining force is weak, and conversely, if strong, the molten resin may leak from the joining end surface into the hollow molded product.

JP-A-10-166449 JP 2009-220429

  Thus, Patent Document 1 proposes a molding method in which secondary molding is performed by thermal fusion. According to this method, the first semi-molded product is formed by the first concave portion of the first mold and the first convex portion of the second mold, and the second concave portion of the second mold, The second semi-molded product is injection-molded with the second convex part of the first mold, the second mold is moved upward to face each other, and the heat source enters between the molds. Then, the joining end portion is heated and melted. Next, in a state where the heat source is retracted, the first mold can be brought close to the second mold so that the joining end portions are brought into close contact with each other and can be welded. According to this molding method, it is not necessary to inject a molten resin for joining when joining the end faces of a pair of semi-molded products. Therefore, the injection machine or the injection operation is simplified, and sufficient joining strength can be obtained. Further, there is an advantage that a hollow molded article having a complicated shape having a joint portion inside such as a rib as described above can be manufactured. Furthermore, since the joining end face of the semi-molded product can be melted in the primary molded mold to produce a hollow molded product in the mold, a hollow molded product with high dimensional accuracy can be obtained, such as a welding jig However, there is an advantage that a hollow molded product can be manufactured at a low cost.

  However, there are problems with the heat source. That is, Patent Document 1 does not particularly explain the heat source, but the heater may be a sheathed heater, a ceramic heater, an induction heater, or the like. Since these heaters have a disadvantage that the rise time from the power supply to the predetermined temperature is long, it is necessary to start the power supply in anticipation of the rise time. By the way, generally the heating of the target object by a heater is performed by radiation by infrared radiation. Since these heaters have a relatively low temperature of about 600 ° C., the emitted infrared rays have many components of far infrared rays. Since far-infrared radiation has relatively low radiation energy, it takes time to heat the object, and since the wavelength is long, the ability to penetrate into the object is high, and the inside of the object is also heated. For this reason, until the resin on the surface is sufficiently melted, it melts not only near the surface of the resin but also inside. In addition, since it takes time to melt, the resin may be heated for a long time and the quality may be impaired. Furthermore, the influence of heat conduction is increased. That is, if the heating time is long, the air around the heating body is heated, and the heated air heats the resin in a wide range, so that the quality of the resin is further impaired.

  Therefore, Patent Document 2 proposes a method for forming a hollow molded product using a halogen heater or a carbon heater. According to this usage, the movable mold and the fixed mold are used to form the first and second semi-molded products so as to have joint end surfaces, and the movable mold is slid with the second semi-molded article remaining. The respective joining end faces can be aligned, a heater made of a halogen heater or a carbon heater can be inserted between them, the joining end faces can be melted, then the heater can be retracted, and the mold can be closed to weld the joining end faces.

  According to the molding method described in Patent Document 2, a halogen heater or a carbon heater is used for melting the joining end surface of the semi-hollow molded product, so that the target temperature is quickly reached when power is supplied to the heater. Therefore, according to the molding cycle, in other words, it is only necessary to supply power to the heater only when the resin on the joining end face is melted, and furthermore, it is easy to adjust the strength of the temperature, so that it can be joined without consuming wasteful energy. An effect is also obtained. Thus, since the heater control response is excellent, the heater can be finely controlled in accordance with the type of resin, the shape and size of the joining end face, and the like. In addition, since these heaters emit near infrared rays and mid infrared rays, only the relatively surface vicinity of the joining end face is melted, and other parts not related to joining are not melted. . Further, since the heater has a linear shape covered with a tubular quartz glass, the heater can be formed in an arbitrary shape with a single stroke. Therefore, the heater can be easily formed in a shape similar to the shape of the joining end face, and only the joining end face can be melted.

  According to the halogen heater or the carbon heater, a number of effects can be obtained as described above. However, problems may arise when the fused portion is long in the vertical direction or the vertical direction. The reason will be described below. 4A is a perspective view showing a hollow molded product in which the semi-hollow molded products A ′ and B ′ are heat-sealed at the joining end surfaces S ′ and S ′ in the mold, and FIG. (A) is a cross-sectional view as seen in the Y direction. When a heater is inserted between the joining end faces S ′ and S ′ of the semi-hollow molded products A ′ and B ′ to heat the joining end faces, The heat that has heated the longitudinal joining end faces S′t, S′t in the direction of gravity action rises as hot air, as indicated by a number of arrows, and therefore the longitudinal joining end faces S′t. , S′t is heated and melted earlier than the horizontal joining end faces S′h and S′h, or is overmelted. Then, when the joining end surfaces S ′ and S ′ of the semi-hollow molded products A ′ and B ′ are pressure-bonded, fusion burrs are generated on the joining end surfaces S′t and S′t in the vertical direction. Since there is no increase in hot air on the lateral joining end faces S′h and S′h, no burrs are generated. In FIG. 4A, reference numeral 1 'indicates a fixed mold.

  Since the fusion burrs as described above do not occur on the joining end faces S′h and S′h in the lateral direction or the horizontal direction, the semi-hollow bodies A ′ and B ′ shown in FIG. Although it is conceivable to mold in the horizontal direction, that is, in such a way that the semi-hollow molded products A ′ and B ′ are in a vertical relationship, depending on the shape of the semi-hollow molded product, the longitudinal joining end face may be unavoidable. is there. Further, when the molding is performed so that the joining end surfaces S ′ and S ′ are in the vertical direction, the space between the joining end surfaces S ′ and S ′ becomes horizontal, and the heater must be kept in the horizontal direction against gravity. Another problem arises that the heater driving device becomes complicated.

  The present invention has been made in view of the above-described problems. Specifically, a hollow molded product having a complicated shape can be molded with high dimensional accuracy and sufficient bonding strength can be obtained. When melting the joint end face of the above, only the vicinity of the surface of the joint end face can be melted in a short time, and other parts are not melted in a delusion, there is no problem of fusion burrs, thermal degradation of the resin, etc. It is another object of the present invention to provide a method for manufacturing a hollow molded product that can reduce the energy loss and adjust the heating amount according to the melting point, and a hollow molded product manufacturing apparatus that is used for carrying out this method.

  In order to achieve the above object, the present invention provides a method for forming a hollow molded product in which a joint end surface of a semi-molded product that is paired in a mold is melted, and the mold is closed and the joint end surface is fused. The melting is performed using a halogen heater or a carbon heater having a shape similar to the joining end face. At this time, it is configured such that air is blown to the joint end face in the vertical direction or the joint end face in the vertical direction with respect to gravity, or hot air is sucked from the vicinity of the joint end face.

  That is, in order to achieve the above-mentioned object, the invention according to claim 1 is to join a semi-hollow molded product that forms a pair by using a movable mold and a fixed mold that can be closed in the primary molding. And in the secondary molding, a joining end surface of one semi-hollow molded product remaining in the stationary mold, and a joining end surface of the other semi-hollow molded product remaining in the moving mold, Are opposed to each other at a predetermined interval, a heater is inserted between the opposed joining end faces in a non-contact manner, the joining end faces are melted to retract the heater, and the movable mold is moved to the fixed mold In a method for manufacturing a hollow molded product in which the mold is closed against each other or a pair of semi-hollow molded products are pressed against each other in a mold and the joining end faces are fused, a halogen heater or a carbon heater is used as the heater. , Heat generation timing and heat generation temperature And controls, on the joining end face which is in the vertical direction of the positional relationship with respect to gravity, while heated by the heater, or blowing air after heating, or configured to suck the hot air. According to a second aspect of the present invention, in the molding method according to the first aspect, the amount of air to be blown or the amount of hot air to be sucked is configured to increase toward the joint end surface positioned above with respect to gravity.

  The invention according to claim 3 is a combination of a mold and a heater, and the mold includes at least a fixed mold and a movable mold, and the movable mold is moved to the fixed mold at a first position. When the mold is clamped, first and second cavities for forming a pair of first and second semi-hollow molded products having joint end surfaces are configured, and when the movable mold is moved by a predetermined amount, The concave portions constituting the first and second cavities are aligned with each other, and in the aligned second position, the parting surface of the fixed mold and the movable mold can be held at a predetermined interval, and the A manufacturing apparatus capable of clamping a moving mold to the fixed mold, comprising an opening of at least one of the recessed part of the fixed mold and the recessed part of the moving mold, In the vicinity of the opening edge that is longitudinal with respect to gravity, the gold A halogen heater or a carbon heater which is provided with an air blowing or suction air hole opened in the parting surface of the first and second semi-hollow molded products and has a shape similar to the joining end surface The heater is provided so as to be freely inserted and retracted between the parting surfaces, and the heat generation timing and the heat generation temperature are controlled. According to a fourth aspect of the present invention, in the manufacturing apparatus according to the third aspect of the present invention, a plurality of the air holes are provided along the opening edges in the vertical direction, and the amount of air blown out or sucked from these air holes is These are adjusted in individual air holes or divided into groups.

  As described above, according to the present invention, in the primary molding, a pair of semi-hollow molded products are molded using a movable mold that can be closed and a stationary mold so as to have a joining end surface, and 2 In the next molding, the joining end surface of one semi-hollow molded product remaining in the fixed mold and the joining end surface of the other semi-hollow molded product remaining in the moving mold are opposed to each other at a predetermined interval. And inserting a heater in a non-contact manner between the opposing joining end faces, melting the joining end faces to retract the heater, and closing the movable mold with respect to the fixed mold, or Since a pair of semi-hollow molded products are pressed against each other in the mold and the joining end faces are fused, that is, the joining end faces of the paired semi-hollow molded articles are melted, and the joining end faces are fused in the mold. Because it wears, it can be molded with high dimensional accuracy even for hollow molded products with complicated shapes. Both sufficient bonding strength can be obtained. According to the present invention, a halogen heater or a carbon heater is used for melting the joint end face of the semi-hollow molded product, so that the target temperature is quickly reached if power is supplied to the heater. Accordingly, it is only necessary to supply power to the heater in accordance with the molding cycle, that is, only when the resin at the joining end face is melted. Further, since the temperature can be easily adjusted, the effect of joining without wasting energy is achieved. Can also be obtained. Thus, since the heater control response is excellent, the heater can be finely controlled in accordance with the type of resin, the shape and size of the joining end face, and the like. In addition, since these heaters emit near infrared rays and mid infrared rays, only the relatively surface vicinity of the joining end face is melted, and other parts not related to joining are not melted. . Further, since the resin can be melted in a short time, the resin is not deteriorated by heat. Furthermore, since these heaters have a linear shape in which the heating element is covered with a tubular quartz glass, the heater can be formed in an arbitrary shape with a single stroke. Therefore, the heater can be easily formed in a shape similar to the shape of the joining end face, and only the joining end face can be melted. Further, since the heater is composed of a halogen heater or a carbon heater, it can be reduced in weight, and can be driven even with an inexpensive and small driving device. Thus, since the drive device can be reduced in size, it becomes easy to provide a robot chuck or the like for taking out a molded product in the vicinity of the manufacturing apparatus. In addition, since quartz glass does not deform even at high temperatures, the distance between the joining end face and the heater can be adjusted with high accuracy, and only the portion to be melted can be accurately melted.

  In particular, according to the present invention, in addition to the above-described effects, air is blown or joined to the joining end faces that are in a vertical positional relationship with respect to gravity when heated by the heater or after heating. Since hot air is sucked from the vicinity of the end face, the joining end face in the vertical positional relationship is not overmelted, and an effect peculiar to the present invention that no fusion burr occurs on the joining end face is obtained. Further, according to another invention, the amount of air to be blown or the amount of hot air to be sucked increases toward the joint end surface located above the gravity, so that the joint end surface is uniformly melted and fused with a uniform fusing force.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows the manufacturing apparatus which concerns on embodiment of this invention, The (a) is a perspective view which opens a fixed mold and a moving mold in a double-spread form, The (a) is when a moving mold is closed Sectional drawing which shows the vicinity of the 1st cavity comprised as a cross section, The (c) is sectional drawing which shows the vicinity of the 2nd cavity as a cross section. It is sectional drawing which shows typically the stage in the middle of manufacturing the hollow molded article using the manufacturing apparatus which concerns on embodiment of this invention. It is a top view which shows embodiment of the heater suitable for heating the joining end surface of the semi-hollow molded product which has a rib inside. It is a figure which shows the hollow molded article manufactured by the conventional manufacturing method, The (a) is the perspective view, The (a) is sectional drawing seen in the arrow ii direction in (a).

  The apparatus for manufacturing a hollow molded article according to the present embodiment is composed of a mold and a heater device. First, the mold will be described. In FIG. 1A, the mold according to the present embodiment is shown in a state of being opened in a double-spread manner. The mold is generally composed of a fixed mold 1 shown on the right side in FIG. 1A and a movable mold 20 that is opened and closed with respect to the fixed mold 1. . The moving mold 20 is provided on the movable platen 19 so as to be slidable in the vertical direction. Although the fixed mold 1 is attached to the fixed platen, the fixed platen is not shown in FIG. Similarly, a driving device for driving the movable mold 20 in the vertical direction, a mold clamping device for clamping the movable plate 19 to the fixed plate, an injection unit, and the like are not shown in FIG.

  A fixed-side concave portion 2 of a predetermined size drawn from the parting surface P toward the inside is formed at an upper position of the fixed mold 1 in FIG. This fixed side recessed part 2 is for shape | molding the outer surface of the 1st semi-molded product A so that it may demonstrate later. A fixed-side core 5 having a predetermined size is provided so as to protrude from the parting surface P at a lower position of the fixed mold 1 in FIG. The fixed core 5 is for molding the inner surface of the second semi-molded product B. Although not shown in FIG. 1A, a small recess 9 is formed at a predetermined interval around the fixed core 5 as shown in FIG. 1C. A small convex shape is formed on the joint end surface of the second semi-molded product B by the concave portion 9.

  A movable core 22 is formed at the upper position of the movable mold 20 in FIG. 1A so as to protrude from the parting surface P. This moving core 22 is for molding the inner surface of the first semi-molded product A, as will be described later. Therefore, the moving core 22 is smaller than the fixed recess 2 by the thickness of the first semi-molded product A. A moving-side recess 25 that is larger than the fixed-side core 5 by a predetermined amount is provided at a position below the moving mold 20 in FIG. This movement side recessed part 25 is for shape | molding the outer surface of the 2nd semi-molded product B. As shown in FIG. Therefore, the moving-side recess 25 is larger than the fixed-side core 5 by the thickness of the second semi-molded product B. According to the present embodiment, since the pair of first and second semi-molded products A and B have the same size and the same shape for convenience, the fixed-side recess 2 and the moving-side recess 25 have the same size and the same shape. The fixed core 5 and the movable core 22 have the same size and the same shape. As shown in FIG. 1A, a small recess 23 is formed on the outside of the moving core 22. A small convex shape is formed on the joint end surface of the first semi-molded product A by the concave portion 23.

  According to the present embodiment, as shown in FIG. 1A, the opening 3 of the fixed recess 2 has upper and lower horizontal opening edges 3U and 3L and left and right vertical opening edges 3S. 3S. These vertical opening edges 3S, 3S have a vertical positional relationship with respect to gravity. The opening 26 of the moving-side recess 25 also includes horizontal opening edges 26U and 26L having the same shape and left and right vertical opening edges 26S and 26S. According to the illustrated embodiment, since the openings 3 and 26 are substantially square, the vertical opening edges 3S, 26S,... Are linear, but the openings or opening edges are circular. Even in the case of a curved shape, there is an opening edge in the vertical direction.

  According to the present embodiment, a plurality of air holes 4, 4,... Are provided at predetermined intervals in the vertical direction on the side portions of the left and right vertical opening edges 3S, 3S of the fixed side recess 2. Yes. A plurality of air holes 7, 7,... Are also provided in the vertical direction on the side portions of the left and right vertical opening edges 26S, 26S of the moving side recess 25. FIGS. 1A and 1C are cross-sectional views showing a state in which the moving mold 20 is clamped to the fixed mold 1 at the primary molding position. The configuration of the side recess 2, the moving side core 22, the air holes 4, 4... Will be described in more detail. A fixed-side recess 2 is formed on the parting surface P side of the fixed mold 1, and a plurality of air holes 4, 4,... Constitute the opening 3 of the fixed-side recess 2. Opening is performed obliquely on the parting surface P, that is, in the direction of the opening 3 in the vicinity of the outside of the opening edges 3S and 3S in the vertical direction. A plurality of such air holes 4, 4,... Are provided at predetermined intervals in the vertical direction as shown in FIG. Air is blown from the air holes 4, 4,... In the direction of the left and right vertical opening edges 3S, 3S, or hot air is sucked from the vicinity of the left and right vertical opening edges 3S, 3S, and left and right vertical edges. The joining end surface in the direction is heated to an appropriate temperature. These air holes 4, 4, ... are connected to the respective plenum chambers 6, 6, ..., and the plenum chambers 6, 6, ... are connected to an air source (not shown). Although not specifically shown in FIG. 1, the air holes 4, 4,... Are managed individually or grouped into a plurality of groups. The air holes 7, 7,... Are also formed in the vicinity of the longitudinal opening edges 26S, 26S of the moving side recess 25 of the moving mold 20. These air holes 7, 7,... Are connected to the respective plenum chambers 8, 8,..., And the plenum chambers 8, 8, etc. are connected to an air source and are managed individually or in groups. It is like that.

  A first gate 11 for primary molding connected to an injection unit (not shown) is opened at the bottom of the fixed-side recess 2 thus configured. In addition, a second gate 12 connected to the injection unit similarly opens at the top of the fixed core 5. In the present embodiment, secondary molding is performed with a heater, so there is no runner, gate or the like for secondary molding, and a simple mold structure is obtained.

  Although the heater device is not shown in the drawing, a linear heater having a predetermined thickness formed in a predetermined shape, a power supply control device that supplies power to the heater as needed, and the heater as a fixed mold 1 It is comprised from the drive device etc. which are inserted and retracted between the movable molds 20. The heater is a halogen heater or a carbon heater. The halogen heater includes a filament made of tungsten, a tube-shaped quartz glass covered with the filament, and a halogen gas sealed in the tube. When power is supplied to the filament and the filament becomes hot, tungsten atoms evaporate from the filament, but the halogen gas temporarily bonds with the tungsten atoms due to the so-called halogen cycle effect, and then returns the tungsten atoms to the filament. Consumption is suppressed, and the filament can be heated to a high temperature and has a long life. On the other hand, the carbon heater is composed of a heating element made of carbon wire and a tubular quartz glass covered on the heating element. The carbon heater can also be heated to a high temperature and has a long life. Since such a heater reaches the target temperature 1 to several seconds after the start of power feeding, the control responsiveness is good and the temperature can be easily adjusted. The halogen heater emits near infrared light having a center wavelength of about 1.2 μm, and the carbon heater emits medium infrared light having a center wavelength of about 2 to 3 μm. Since both near-infrared rays and mid-infrared rays have large radiation energy, the resin can be melted in a short time. And since these infrared rays have a small ability to penetrate into an object, only the resin in the vicinity of the surface is quickly melted and the quality of the resin is not impaired. Since the mid-infrared has the ability to penetrate into the object slightly compared with the near-infrared, the thickness of the molten resin is slightly thick, but it is easily absorbed by the resin and efficiently melts the resin.

  Next, a manufacturing example of a hollow molded product using the manufacturing apparatus will be described with reference to FIG. The movable mold 20 is driven to the first molding position, that is, the position shown in FIG. 1A, and the mold is clamped by the mold clamping device. Then, as already described, the first cavity C1 for forming the first semi-molded product A is constituted by the fixed recess 2 of the fixed mold 1 and the moving core 22 of the moving mold 20; The fixed side core 5 and the moving side concave portion 25 constitute a second cavity C2 for molding the second semi-molded product B. These first and second cavities C1 and C2 are shown in FIGS. 1A and 1C, respectively.

  The plasticized molten resin is injected from the injection unit. The molten resin passes through the sprue, the runner and the like, and is filled into the cavities C1 and C2 through the first and second gates 11 and 12 almost simultaneously. As a result, the first and second semi-molded products A and B are molded substantially simultaneously. At this time, as shown in FIG. 2, small convex shapes a 'and b' are also formed on the joining end faces a and b of the first and second semi-molded products A and B, respectively. Wait for some cooling and solidification. This completes the primary molding.

  Next, the movable platen 19, that is, the moving mold 20 is opened. Then, the first and second semi-molded products A and B have the first semi-molded product A toward the fixed mold 1 and the second semi-molded product B depending on the shape, area, presence or absence of protrusions, and the like. Are left open on the moving mold 20 respectively. The movable mold 20 is slid to the upper second position. Then, the joining end surfaces a and b of the first and second semi-molded products A and B are aligned with a predetermined interval. Such an aligned state is shown in FIG.

  Depending on the type of resin, the shape and size of the joining end faces a and b, the strength of joining, the energization timing, the heat generation temperature, etc. are set in the power supply control device. The heater is driven and inserted between the joining end faces a and b. When inserted, the distance between the surface of the heater and the joining end surface a, and between the surface of the heater and the joining end surface b, more strictly between the small convex shapes a 'and b', is about 0.5 mm to 50 mm. Then, power is supplied to the heater. Then, near-infrared rays or mid-infrared rays are irradiated to the joining end surfaces a and b and the convex shapes a ′ and b ′ and instantaneously heated and melted in a non-contact manner. When melted, power supply to the heater is stopped and the heater is retracted. At this time, air is blown out or sucked from the air holes 4, 4,... 7, 7,. Clamp the mold. By the mold clamping, the first and second semi-molded products A and B are spread by the small convex shapes a ′ and b ′ and welded at the joining end surfaces a and b. This completes the secondary molding. When the moving mold 20 is opened, an ejector pin (not shown) protrudes and a hollow molded product is taken out. The moving mold 20 is slid to the first position shown in FIG. 1A, and primary molding is performed as described above. Thereafter, a hollow molded product is produced in the same manner.

  According to the present embodiment, air is blown to the joint end faces a and b that are in a vertical positional relationship with respect to gravity, or because hot air is sucked, the joint end faces a and b in the vertical direction and other joint end faces Are heated to the same degree, and the joining end faces a and b are not overheated. Therefore, no fusion burr is produced by fusion without excess or deficiency.

  Next, a heater device in the case of manufacturing a tank whose interior is divided into a plurality of chambers by a plurality of ribs will be described. In FIG. 3, the openings X and X ′ and the internal ribs Y and Z of one semi-hollow molded product constituting the tank are shown by dotted lines. The opening made up of X and X 'has a substantially square shape, but the ribs Y and Z are cut halfway. The openings X and X 'and the ribs Y and Z are joint end faces, and these are fused to the opening and rib joint end faces of the other semi-hollow molded product by secondary molding. Although it will be easily understood by those skilled in the art, it will not be described in detail. However, when such a pair of semi-hollow molded products are fused at the joining end surfaces, a tank whose interior is divided into three chambers is formed. It will be. When melting such a joining end face, at least two heaters are required. FIG. 3 shows a first heater H1 that melts the joining end face of the semi-hollow molded product, that is, the openings X and X, and a second heater H2 that melts the joining end face of the ribs Y and Z and the openings X ′ and X ′. It is formed as shown in FIG. The first and second heaters H1 and H2 are supplied with power from the power supply control device S. Also in this embodiment, when a longitudinal joining end face exists, overheating is prevented by blowing air on the joining end face or sucking hot air.

  According to the present embodiment, since a halogen heater or a carbon heater is applied as the heater, the gap between the joining end faces a and b is as narrow as 0.5 mm to 50 mm as described above. Therefore, the air can be blown only from one of the air holes 4, 4,... Of the fixed mold 1 or the air holes 7, 7,. . In the above embodiment, an example of manufacturing a completely sealed hollow molded product has been described. However, it is obvious that a hollow molded product partially opened can be manufactured in the same manner. It is also clear that one hollow molded product can be manufactured from three or more primary molded products. Accordingly, the hollow molded product includes a molded product partially opened and a hollow molded product molded from a plurality of half molded products of three or more. It is also clear that the present invention can be implemented by rotating the moving mold 20 instead of sliding. Further, in the above embodiment, the secondary molding is performed by clamping the movable mold 20 to the fixed mold 1, but the secondary molding is performed using another mold not shown. It can also be used to melt the joining end face as described above and to fuse the joining end face. Furthermore, it is possible to carry out temperature-adjusted air spraying on the longitudinal joining end face, or with a single air hole on the joining end face which is low in the longitudinal direction.

DESCRIPTION OF SYMBOLS 1 Fixed metal mold | die 2 Fixed side recessed part 3 Opening part of fixed side recessed part 3S The opening edge of the vertical direction of an opening part
4 Fixed side air holes 5 Fixed side core
7 Movable side air hole 20 Moving mold 22 Moving side core 25 Moving side recess 26 Moving side recess opening 26S Vertical opening edge of opening

Claims (4)

In the primary molding, a pair of semi-hollow moldings are molded to have a joining end surface using a movable mold and a stationary mold that can be closed, and remain in the stationary mold in the secondary molding. A heater between the joint end faces facing each other, with the joining end face of the one semi-hollow molded article and the joining end face of the other semi-hollow molded article remaining in the moving mold facing each other at a predetermined interval. Is inserted in a non-contact manner, the joining end face is melted to retract the heater, and the moving mold is closed with respect to the fixed mold, or a pair of semi-hollow molded products are placed in the mold. In the method of manufacturing a hollow molded product that is pressed against each other to fuse the joining end faces,
As the heater, a halogen heater or a carbon heater is used to control the timing and temperature of heat generation, and the joint end face in the vertical position with respect to gravity is heated by the heater, Alternatively, a method for producing a hollow molded article, wherein air is blown after heating or hot air is sucked from the vicinity of the joining end face. 2. The method for manufacturing a hollow molded article according to claim 1, wherein the amount of air to be blown or the amount of hot air to be sucked is increased toward the joint end face located above in relation to gravity. It consists of a combination of a mold and a heater.
The mold includes at least a fixed mold and a movable mold, and when the movable mold is clamped with respect to the fixed mold at a first position, a pair of first and second halves having joint end surfaces are provided. First and second cavities for forming a hollow molded product are configured, and when the movable mold is moved by a predetermined amount, the concave portions constituting the first and second cavities are aligned with each other, and the aligned In the second position, the manufacturing apparatus can hold the fixed mold and the parting surface of the moving mold at a predetermined interval and can clamp the moving mold to the fixed mold. There,
An opening is formed in the parting surface of the mold in the vicinity of the opening edge that is in the vertical direction with respect to gravity, constituting the opening of at least one of the recessed part of the fixed mold and the recessed part of the moving mold Air holes for air blowing out or suction are provided,
The heater is composed of a halogen heater or a carbon heater having a shape similar to the joining end surface of the first and second semi-hollow molded products, and the heater is provided so as to be inserted and retracted between the parting surfaces. And a device for manufacturing a hollow molded product in which the timing and temperature of heat generation are controlled. 4. The manufacturing apparatus according to claim 3, wherein a plurality of the air holes are provided along the opening edge in the vertical direction, and the amount of air blown out from these air holes or the amount of air to be sucked in is individual air holes or in groups. A device for manufacturing a hollow molded product that is adjusted separately.

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