JP5073704B2 - Method and apparatus for forming hollow molded product - Google Patents

Description

In the present invention, in primary molding, a pair of semi-molded products are integrally formed to have a joining end surface using a movable mold that can be opened and closed and a fixed mold, and one half-molded product is fixed. With the other half-molded product remaining on the movable mold, the movable mold is moved relative to the fixed mold, and the paired half-molded products are opposed to each other with the joint end surfaces separated from each other. The present invention relates to a molding method and a manufacturing apparatus for a hollow molded product, in which a heater is inserted to melt a joined end surface to retract the heating body, and in secondary molding, a mold is closed and the joined end surface is crimped to obtain a hollow molded product. Is.

  A molding method using an injection molding machine is known as one method for producing a hollow molded product made of synthetic resin having a complicated shape, such as a curved pipe, an intake manifold, a tank or the like. This injection molding machine is composed of a set of molds as shown in Patent Documents 1 and 2. One mold of a set of molds is provided with a male mold and a female mold for forming one half hollow body, and the other mold is formed with the other half hollow body. A female mold and a male mold are provided. Therefore, the hollow body product is formed as a half-hollow body or split body in the primary molding by these molds, the split surfaces are butted in the secondary molding, and the molten resin is injected and filled into the joined space As a result, one hollow body product is obtained in which the pair of semi-hollow bodies are joined at the split surfaces. That is, a hollow molded product can be manufactured by injection molding. According to the molding method using this injection molding machine, a completely sealed hollow body product can be produced, and a hollow body product with a uniform wall thickness can be produced, and complex shapes can be dealt with, etc. There are also advantages. However, some hollow body products may be difficult to manufacture by this molding method. For example, when manufacturing a hollow body whose interior is partitioned by ribs or wall surfaces, such as a tank whose interior is divided into a plurality of compartments by a plurality of ribs, the rib portion also needs to be joined in secondary molding. This manufacturing method is difficult to manufacture. Further, in this molding method, since the joining molten resin must be injected in the secondary molding, the structure of the injection machine or the molding time is long, and the mold structure may be complicated. Furthermore, if the secondary injection pressure is small, the joining force is weak, and conversely, if it is strong, the molten resin may leak into the hollow body product from the joining space.

JP-A-62-87315 JP-A-6-246781 Japanese Patent No. 3855083

  On the other hand, Patent Document 3 can be cited as a direct prior art of the present invention. In Patent Document 3, the joined end surface of the paired semi-hollow molded product that is primary-molded is heated and melted in a non-contact manner with a heating body, and the paired semi-hollow molded product is pressed against the joined end surface to be hollow. A molding method for obtaining a molded article is described. According to this molding method, a mold consisting of a movable mold and a fixed mold is clamped to form a pair of semi-hollow molded articles so as to have a joining end surface, and one of the semi-hollow molded articles is converted into a movable mold. The mold is opened with the other half-hollow molded product remaining in the fixed mold. Next, the movable mold is slid to face the pair of semi-hollow molded products. At this time, the joining end surfaces of the pair of semi-hollow molded products are separated by a predetermined distance that is relatively close. During this time, a heating element provided with a sheet heater composed of a sheathed heater, a ceramic heater, an induction heater, etc. is inserted to melt the joint end surface in a non-contact manner and retract the heating element, and then the mold is closed. Then press the semi-hollow molded product in the mold to melt and crimp the joint end face.

  According to the invention described in Patent Document 3, since it is not necessary to inject molten resin for joining when joining the joining end faces of a pair of semi-hollow molded products, the injection machine or the injection operation becomes simple, Sufficient bonding strength can be obtained. Further, there is an advantage that even a hollow molded product having a complicated shape having a joint portion inside such as a rib as described above can be easily manufactured. Furthermore, since the joint end face of the semi-hollow molded product can be melted in the primary molded mold to produce the hollow molded product in the mold, a hollow molded product with high dimensional accuracy can be obtained, and the welding jig Etc. are not particularly required, and there is an advantage that a hollow molded product can be manufactured at low cost. However, there are some points that should be improved. For example, the heating element in the invention described in Patent Document 3 is composed of a planar heater, but even if power is supplied to the heater, the heating element is deprived of heat at first and the temperature does not rise immediately. Therefore, in preparation for the process of melting the joint end faces, it is necessary to always supply power to the heater to heat the heating element, which requires wasteful energy and provides special heat insulation so that heat does not escape from the heating element to the outside. There is also a need to consider. Moreover, since a heating body will be heated uniformly, adjustments, such as heating at different temperature according to a fusion | melting location, cannot be performed. And since it heats with a planar heater, the range to heat will become wide and parts other than a joining end surface may also melt | dissolve. Furthermore, a problem is recognized also when the joining end surface has a complicated and three-dimensional shape that does not rest on the same plane. That is, it is difficult to make the shape of the planar heater correspond to such uneven three-dimensional joint end faces, and even if it is three-dimensionally formed to correspond, only a relatively close predetermined interval is opened. It is nearly impossible to insert between a pair of semi-hollow molded parts that are not formed. In addition, since the heating element made of a planar heater has a predetermined weight, there is a problem that a relatively large drive device such as a piston cylinder unit for inserting and withdrawing the heating element between the molds is required. .

There is also a problem with the type of heater. In the invention described in Patent Document 3, there is no particular limitation on the type of heater, but the specification describes a sheathed heater, a ceramic heater, and an induction heater as examples of the heater. These heaters have the disadvantage that the rise time from power feeding to a predetermined temperature is long, so it is necessary to start power feeding in anticipation of the rise time. By the way, generally the heating of the target object with a heater is performed by the radiation by infrared radiation, and the thermal convection through air. 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, the resin on the surface of the joining end surface is melted to the inside before it is sufficiently melted. 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.
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. Even if the shape is complicated, the shape of the heater can be easily accommodated, and even a heater formed in such a complicated shape can be easily inserted between the joining end faces of a pair of semi-hollow molded products The joining end face can be melted in a short time and only the vicinity of the surface can be melted. Therefore, there is no fear of damaging the quality of the resin by melting other parts, and the heating element is an inexpensive driving device. The method of forming a hollow molded product, a hollow molded product, and a heating method that can adjust the amount of heat depending on the melting point with little energy loss, and is light in weight so that it can be driven. Manufacturing It is an object of the present invention to provide a location.

In order to achieve the above object, the present invention provides a method for forming a hollow molded product in which a joining end surface of a pair of semi-hollow molded products in a mold is melted, the mold is closed, and the joining end surfaces are pressure-bonded. The melting of the joining end face is composed of a halogen heater or a carbon heater, and is configured to be performed by a linear heater that is formed in a single stroke shape similar to the joining end face. Then, the melting of the joining end face is performed by opening the mold so that the joining end faces are spaced apart at a predetermined interval, inserting the heater in a non-contact manner, and driving the mold in the mold closing direction. It is comprised so that the space | interval of a heater may be narrowed.

Thus, in order to achieve the above-mentioned object, the invention according to claim 1 is to join the semi-molded product paired by using a mold composed of a movable mold and a fixed mold that can be opened and closed in the primary molding. In the secondary molding, the movable mold in which one half-molded product remains is moved with respect to the fixed mold in which the other half-molded product remains, and the joining end surface is predetermined. A linear heater composed of a halogen heater or a carbon heater formed in a stroke shape similar to the joint end face is inserted between the joint end faces spaced apart from each other so as to be spaced apart from each other. Is driven in the mold closing direction, the interval between the joining end surface and the heater is narrowed, the heater is fed with power to melt the joining end surface in a non-contact manner, the moving mold is retracted and the die is closed. When crimping the joint end face, When a non-continuous portion (D) is generated in the portion (E1, E2), so that the two positions of the parts (E1, E2) is set to be above and below the relationship in the vertical direction, inserted between the joining end face Configured.
According to a second aspect of the invention, in the forming method according to claim 1, the heater is configured to use a controllable plurality of heaters independently.

The invention according to claim 3 comprises a combination of a mold and a heater, and the mold has at least a fixed mold and a movable mold, and the movable mold is in a first position with respect to the fixed mold. When the mold is clamped, the first and second cavities for forming the first and second semi-molded products having the joining end surfaces from these molds are configured, and when the movable mold is moved by a predetermined amount, the first, The two cavities are aligned with each other, and at the aligned second position, the movable mold and the fixed mold parting surface can be held in at least two different mold opening amounts and can be clamped. The heater is a linear halogen heater or carbon heater formed in a single stroke shape similar to the joining end surfaces of the first and second semi-molded products, and the heater is between the parting surfaces that have been opened. Near two places when inserted into Portions (E1, E2) when the discontinuous portion (D) is generated in the insertion such that the two positions of the parts (E1, E2) is vertically relationship in the vertical direction, provided freely retracted Yes.

As described above, according to the present invention, the joint end surfaces of the semi-hollow molded products that are paired in the mold are melted, the mold is closed, and the joint end surfaces are pressure-bonded. However, it can be molded with high dimensional accuracy and sufficient bonding strength can be obtained. The melting of the joining end face of the semi-hollow molded product is performed by inserting a linear halogen heater or carbon heater formed in a single stroke shape similar to the joining end face. If the power is supplied to, the target temperature is reached quickly. Accordingly, it is sufficient to supply power to the heater in accordance with the molding operation, that is, only when the resin for secondary molding is melted, and the temperature can be adjusted. Thus, since the control responsiveness of the heater is excellent, it is possible to control the heater finely according to the heating condition. Further, since these heaters emit near infrared rays and medium infrared rays, only the relatively near surface of the joining end face is melted and melted in a short time, so there is no problem of thermal deterioration of the resin. In particular, according to the present invention, a linear heater formed in a single stroke shape similar to the joint end face is once inserted between the joint end faces of the semi-molded product, and then the mold is driven in the mold closing direction to join the end face. Therefore, even if the shape of the joining end face is complicated, the heater can be easily inserted and the joining end face can be appropriately melted. Accordingly, various shapes of hollow molded articles can be manufactured without being restricted by the shape of the joining end face. According to another invention, these heaters have a linear shape, so that the heaters can be formed in an arbitrary shape in a single stroke. Therefore, the heater can be easily made similar to the shape of the joining end face, and only the joining end face can be melted. In addition, since only the local area can be heated, there is no need to protect a portion other than the joining end face with a heat insulating material, the entire heater can be reduced in weight, and can be driven by an inexpensive and small driving device. . As described above, since the driving device can be reduced in size, it is easy to provide a robot chuck or the like for taking out a molded product in the vicinity of the manufacturing apparatus. Furthermore, since quartz glass does not deform even when the temperature rises, the distance between the joining end face and the heater can be adjusted with high accuracy, and the effect that only the joining end face can be accurately melted can also be obtained. In addition , when the heater is formed in a single stroke and a discontinuous portion is generated in two adjacent portions, the two portions are in a vertical relationship between the joint end surfaces. Since it inserts, heat rises so that a discontinuous part may be filled, and the effect that the joint end face located in a discontinuous part can also fully fuse | melt is acquired. According to yet another aspect of the present invention, because it uses independently controllable plurality of heaters, joining end face of the magnitude in addition to the above effects, shape, heated at a temperature suitable for the position and the like, and melt The effect of crimping is obtained.

It is a figure which shows the manufacturing apparatus which concerns on embodiment of this invention, (a) is sectional drawing shown in the state which closed the metal mold | die, (i) is a perspective view which shows a heater apparatus. BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic diagram for demonstrating the shaping | molding method of the hollow molded article which concerns on embodiment of this invention, The (a)-(e) shows each step in the middle of manufacturing a hollow molded article. It is sectional drawing. BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic diagram for demonstrating the shaping | molding method of the hollow molded article which concerns on embodiment of this invention, The (a)-(e) shows each step in the middle of manufacturing a hollow molded article. It is sectional drawing. Description of a pair of semi-hollow molded products having ribs inside and joint end surfaces formed in three dimensions, and a heater device for molding a hollow molded product having ribs inside from such a pair of semi-hollow molded products (A) is a perspective view showing a pair of semi-hollow molded products and a heater device, and (a) is a side view showing the joining end surfaces of the pair of semi-hollow molded products being melted by the heater device. It is.

  The manufacturing apparatus according to the present embodiment is composed of a mold and a heater device as shown in FIG. First, the mold will be described. In FIG. 1A, the mold according to the present embodiment is shown in a clamped state, but the mold is schematically a fixed mold 1 and a mold relative to the fixed mold 1. The movable mold 2 is opened and closed, the movable mold 2 is provided with a movable mold 3 that is slidably driven in the vertical direction in the figure, a piston cylinder unit 4 that drives the movable mold 3, and the like.

  In the present embodiment, the parting lines P of the fixed mold 1 and the movable mold 3 are not placed on the same plane. Specifically, the parting line P is composed of a plurality of surfaces P1, P2, P3, P4,..., And the surfaces P1 and P3, and the surfaces P2 and P4 constitute the same plane. P1 and surface P2 are not on the same plane. Further, although not shown in FIG. 1A, among the surfaces constituting the parting line P, the surface connecting the surfaces P1 and P2, and the surfaces P3 and P4 are connected. The inclined surface is inclined at a predetermined angle with respect to the surfaces P1, P2, P3, and P4. That is, the parting line P is three-dimensionally formed from a plurality of surfaces. A recessed portion 11 having a predetermined size that is recessed from the parting line P toward the inside is formed at an upper position of the fixed mold 1 in FIG. As will be described later, the recess 11 is for molding the outer surface of the first semi-molded product A. A hemispherical core 12 is provided so as to protrude from the parting line P at a lower position in FIG. The core 12 is for molding the inner surface of the second semi-molded product B.

  A gate (not shown) that communicates with the first sprue 14 is formed at the top of the concave portion 11 configured as described above, and a gate that is communicated with the second sprue 15 is not illustrated near the core 12 of the parting line P. Each gate is open. The first and second sprues 14 and 15 communicate with a resin hole of a locating ring (not shown) through a runner 16 and a main spru 17 formed in the fixed mold 1. The main sprue 17, runner 16, and sprues 14 and 15 are for primary molding, and in this embodiment, there are no secondary molding runners, sprues, and the like.

  On the upper parting line P side of the movable mold 3 in FIG. 1A, a hemispherical core that protrudes from the parting line P toward the fixed mold 1 and that forms a pair with the recess 11 of the fixed mold 1 31 is provided. When the movable die 3 is slid to a first position to be described later and clamped together with the fixed die 1, the first portion is formed by the recess 11 of the fixed die 1, the parting line P of the movable die 3, and the core 31. A first cavity C1 for forming the semi-molded product A is configured. As described above, the outer surface of the first half-molded product A is formed by the recess 11 and the inner surface is formed by the core 31. The height of the core 31 is lower than the depth of the recess 11, so that the first half-molded product A A is formed with a predetermined thickness. The joining end face of the first semi-molded product A to be joined with the second semi-molded product B is formed by the parting line P of the movable mold 3. Since the parting line P is three-dimensionally formed as described above, the joining end surface is formed in a three-dimensional shape that is not placed on the same plane.

  A recessed portion of a predetermined size, which forms a pair with the core 12 of the fixed die 1 and is recessed toward the inside from the parting line P on the lower parting line P side of the movable die 3 in FIG. 32 is formed. When the movable mold 3 and the fixed mold 1 are clamped at the first position, the second semi-molded product B is formed by the parting line P of the fixed mold 1, the core 12, and the recess 32. A cavity C2 is formed. As described above, the inner surface of the second semi-molded product B is formed by the core 12, and the outer surface is formed by the recess 32. The depth of the recess 32 is deeper than the height of the core 12, so that the second semi-molded product B B is formed with a predetermined thickness. The joining end surface of the second semi-molded product B to be joined with the first semi-molded product A is formed by the parting line P of the fixed mold 1. The parting line P is three-dimensionally formed, and the joining end surface is formed in a three-dimensional shape congruent with the joining end surface of the first semi-formed product A.

  The movable mold 3 is slid by the piston cylinder unit 4 and can take the first and second positions with respect to the fixed mold 1. FIG. 1A shows a primary molding position, that is, a state in which the movable mold 3 is clamped with the first position relative to the fixed mold 1. When the fixed mold 1 and the movable mold 2 are opened and the piston cylinder unit 4 is driven, the movable mold 3 can take the second position with respect to the fixed mold 1. In the second position, the concave portion 11 of the fixed mold 1 and the concave portion 32 of the movable mold 3 face each other. Therefore, as will be described later, a hollow molded product can be obtained by melting the joint end faces of the first and second semi-molded products A and B at this second position and clamping them.

  By the way, according to the present embodiment, in this second position, the movable mold 2, that is, the movable mold 3, has a relatively large distance between the movable mold 3 and the fixed mold 1 relative to the fixed mold 1. The position and the narrow second mold opening position can be taken. When the first mold opening position is adopted, the heater 41 described below can be easily inserted and retracted between the movable mold 3 and the fixed mold 1, and the distance between the movable mold 3 and the fixed mold 1 is increased. When the narrow second mold opening position is adopted, the joining end surfaces of the first and second semi-molded products A and B can be brought close to the heater 41.

  The heater device 40 will be described. The heater device 40 according to the present embodiment is provided in the vicinity of the fixed die 1 and the movable die 3, and is roughly a linear heater 41 having a predetermined thickness formed in a predetermined shape, The heater 41 is composed of a drive device or the like for inserting or retracting the heater 41 between the fixed mold 1 and the movable mold 3.

  The heater 41 is a halogen heater or a carbon heater. The halogen heater is composed of 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 binds to the tungsten atoms due to the so-called halogen cycle effect, and then returns the tungsten atoms to the filament. Consumption is suppressed, 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 heated quickly and the quality of the resin is not impaired. In addition, the mid-infrared has the ability to penetrate into the object slightly compared with the near-infrared, so the thickness of the resin to be melted is slightly thick, but it is easily absorbed by the resin and efficiently melts only in the vicinity of the joint end face. .

  Such a heater 41 is formed in a single stroke so as to resemble the shape of the joint end surface, but the shape of the joint end surface is a three-dimensional shape that does not rest on the same plane as described above. The shape of the heater 41 is also three-dimensionally formed in accordance with the shape of the joining end face, as shown in FIG. At this time, a gap that cannot be formed with a single stroke, that is, a break portion or a discontinuous portion D is generated. The break portion D is substantially sandwiched between two portions E1 and E2 in the vicinity of the break portion D from above and below in the vertical direction. Even if the heater 41 is inserted between the joining end faces and the heater 41 is heated, near infrared rays and middle infrared rays are not radiated from the break portion D, so that the portion of the joining end surface corresponding to the break portion D is irradiated. The heat dose is reduced. However, if the heater 41 is arranged so that the portions E2 and E1 are vertically related to each other in the vertical direction, the break portion D is positioned above the portion E2, so that hot air that is heated by the portion E2 of the heater 41 and rises. The air also sufficiently heats and melts the joining end surface corresponding to the break portion D.

  Such a heater 41 is supported by the heat-resistant support portion 42 and attached to the drive device. The drive device includes a guide rail 44 attached to a member (not shown), a support frame 45 guided by the guide rail 44, a piston cylinder unit 46 that drives the support frame 45, and the like. And the heater 41 is attached to the front-end | tip part of the support frame 45 via the heat-resistant support part 42. As shown in FIG. When the piston cylinder unit 46 is driven, the heater 41 is inserted between the fixed mold 1 and the movable mold 3 or retreats to the position shown in FIG. The heater 41 is supplied with power from the power control device 47 through cables 48 and 48 as necessary.

  Next, with reference to FIG. 2 and FIG. 3, a molding method for manufacturing a hollow molded product using the above manufacturing apparatus will be described. The piston cylinder unit 4 is driven, the movable mold 3 is slid to the first position, that is, the position shown in FIG. 2A, and the mold is clamped by a mold clamping device (not shown). Then, as already described, the first cavity C1 for molding the first semi-molded product A and the second cavity C2 for molding the second semi-molded product B are configured. A plasticized molten resin is injected through a main sprue 17 from an injection machine (not shown). The molten resin is filled from the runner 16 and the first and second sprues 14 and 15 into the cavities C1 and C2 almost simultaneously via the gates. As a result, the first and second semi-molded products A and B having the joining end surfaces are molded substantially simultaneously. Wait for some cooling and solidification. This completes the primary molding.

  Next, as shown in FIG. 2A, the movable mold 2, that is, the movable mold 3, is opened so as to be in the first mold opening position. Then, the first semi-molded product A is directed toward the fixed mold 1 and the second semi-molded product B is directed toward the movable mold 3 depending on the shape, area, or presence or absence of protrusions of the semi-molded products A and B, respectively. It remains and is opened.

  As shown in FIG. 2C, the piston cylinder unit 4 is driven to slide the movable die 3 to the 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. The piston cylinder unit 46 is driven. Then, the heater 41 is inserted between the joining end surfaces a and b. At this time, since the fixed mold 1 and the movable mold 3 are opened to the first mold opening position and the mold opening amount is relatively large, even if the heater 41 is formed in a three-dimensional shape, The heater 41 can be inserted without contact. During or after insertion, fine adjustment is made so that the space between the heater 41 and the joining end surface a is close to, for example, 0.5 mm to 30 mm.

  The movable mold 3 is driven to the second mold opening position. At the second mold opening position, the mold opening amounts of the fixed mold 1 and the movable mold 3 are narrowed, the joining end surface b of the heater 41 and the second semi-molded product B, and the joining of the heater 41 and the first semi-molded product A. The end surfaces a are each close to a distance of 0.5 mm to 30 mm, for example. Power is supplied to the heater 41. Then, the joining end faces a and b are irradiated with near-infrared rays or mid-infrared rays and are heated and melted in a non-contact manner. The state of heating in this way is shown in FIG.

  When the joining end faces a and b are melted, power supply to the heater 41 is stopped. Next, as shown in FIG. 3A, the movable mold 2, that is, the movable mold 3, is opened so as to be in the first mold opening position. As shown in FIG. 3A, the piston cylinder unit 46 is driven to retract the heater 41. Then, the mold is clamped as shown in FIG. With this clamping force, the first and second semi-molded products A and B are welded at the joining end surfaces a and b. As shown in FIG. 3D, the mold is opened so as to be in the first mold opening position, and an ejector pin (not shown) is protruded to take out the hollow molded product AB. The movable mold 3 is slid to the first position shown in FIG. 2A, and primary molding is performed as described above. In the same manner, the hollow molded product AB is manufactured.

  With the manufacturing apparatus according to the present embodiment, a tank whose interior is divided into a plurality of chambers by a plurality of ribs can be manufactured. 4A, first and second semi-molded products 51 and 52 constituting a tank having two ribs 57 and 58 therein, and joining end faces 55 of these semi-molded products 51 and 52, A heater 53 for melting 56 is shown. The second half-molded product 52 is shown rotated in the direction of the arrow Y1.

  As shown in FIG. 4A, the opening of the first semi-molded product 51 includes a first opening A located above, a third opening C located below, It consists of the 2nd opening part B located in the middle of these. A three-dimensional joining end surface 55 is formed from the top surfaces of these openings A, C, and B. More specifically, the first opening A is configured to have a planar shape from the upper side a, the left and right side parts d and f, and the first rib 57. The third opening C is also configured to have a planar shape from the second rib 58, the left and right side portions e and g, and the lower side portion c in substantially the same manner. On the other hand, the second opening B is composed of the first and second ribs 57 and 58 and the left and right side portions d ′ and f ′, but is substantially at the center of one side portion f ′. The portion is a protruding portion 60 that protrudes smoothly forward. The third opening C is lower or shallower than the first opening A. Therefore, in FIG. 4A, one side part d, d ', e shown on the left side and the other side part f, f', g shown on the right side are shown in FIG. As shown in the side view of (A), they are connected by a smooth curve. Thus, according to this Embodiment, the joining end surface 55 is three-dimensional.

Since the second half-molded product 52 is paired with the first half-molded product 51, a detailed description thereof will not be given, but the joining end surface 56 is similar to the joining end surface 55 of the first half-molded product 51 and is three-dimensional. It has become. As will be readily understood by those skilled in the art, when the first and second semi-molded products 51 and 52 are welded to the respective joining end faces 55 and 56, the inside is divided into three compartments. Will be formed. In FIG. 4A, reference numerals 59 and 59 denote ribs corresponding to the first and second ribs 57 and 58 of the first semi-molded product 51, and reference numeral 61 denotes a side portion d ′. The corresponding side portions are shown respectively.

  At least two heaters 53 for melting the joining end faces 55 and 56 having such a complicated shape are required. FIG. 4A shows first and second heaters 63 and 64 constituting the heater 53. The first heater 63 is formed so as to correspond to the side portions d ′ and f ′ which are the joining end surfaces 55 and 56 and the end surfaces of the first and second ribs 57 and 58. A curved portion 66 is formed corresponding to the protruding portion 60. Therefore, when the first heater 63 is viewed from the direction indicated by the arrow Y2 in FIG. 4A, that is, from the side, the left curved portion 67 and the curved portion 66 do not overlap. The second heater 64 is formed so as to correspond to the upper side a of the first opening A and the lower side c of the third opening C, which are the joining end surfaces 55 and 56, and is formed in the second opening B. The corresponding part is detoured to the outside. Therefore, it does not interfere with the first heater 63. When the second heater 64 is viewed from the side, the left portion 69 and the right portion 70 overlap on the same line. The state in which the heater 53 is inserted between the joining end faces of the first and second semi-molded products 51 and 52 is shown in FIG. Note that the fixed mold 1 and the movable mold 3 are not shown. Also in the manufacturing apparatus according to the present embodiment, the fixed mold 1 and the movable mold 3 can be opened to the first and second mold opening positions. The heater 53 can be inserted without contacting the second half-molded products 51 and 52, and the second mold is opened, so that the heater 53 is non-contacted as shown in FIG. The joint end faces 55 and 56 and the ribs 57 and 58 can be melted.

  The manufacturing apparatus according to the present embodiment can be variously modified. For example, when the rib portions of the joining end surfaces of the first and second semi-molded products as described above are thin and the upper and lower side portions and the side portions are formed thick, power is supplied to the first and second heaters. It can be controlled independently and melted almost simultaneously regardless of the wall thickness. Or it can melt uniformly irrespective of the site | part of a joining end surface. In addition, the heater is described as being driven in the insertion direction and the retraction direction, but not only in such insertion and retraction directions, but also in the direction close to or away from the fixed type or the movable type. It can also be implemented so that it can be driven. When implemented in this manner, when the movable mold is driven to the second mold opening position, that is, when heated, the distance between the joining end surface of the first and second semi-molded products and the heater can be finely adjusted. .

  In the above-described 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. Therefore, the hollow molded product includes a molded product partially opened and a molded product molded from three or more primary molded products. It is also clear that the movable mold can be rotated instead of sliding.

DESCRIPTION OF SYMBOLS 1 Fixed type 2 Movable type 3 Moving type 4 Piston cylinder unit 40 Heater apparatus 41 Heater 46 Piston cylinder unit 47 Power supply control apparatus
C1, C2 first and second cavities
D Cut point E1, E2 Heater part

Claims (3)

In primary molding, a pair of semi-molded products are molded to have a joining end surface by using a mold composed of a movable mold that can be opened and closed and a fixed mold,
In the secondary molding, the movable mold in which one half-molded product remains is moved with respect to the fixed mold in which the other half-molded product remains, so that the joining end surfaces are separated at a predetermined interval. Face each other
A linear heater composed of a halogen heater or a carbon heater formed in a single stroke shape similar to the joining end face is inserted between the separated joining end faces, and the moving mold is driven in the mold closing direction to join. When the gap between the end face and the heater is narrowed, the heater is fed to melt the joining end face in a non-contact manner, the moving mold is retracted, the mold is closed, and the joining end face is crimped. When a discontinuous portion (D) occurs in the adjacent portions (E1, E2), the two portions (E1, E2) are inserted between the joining end faces so that the two portions (E1, E2) are vertically related to each other. A method for forming a hollow molded article, comprising: 2. The molding method according to claim 1 , wherein a plurality of independently controllable heaters are used as the heater. 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 at a first position with respect to the fixed mold, first and second semi-molds having joint end surfaces from these molds. First and second cavities for forming a product are configured, and when the movable mold is moved by a predetermined amount, the first and second cavities are aligned with each other, and are fixed to the movable mold at the second position where they are aligned. Between the parting surfaces of the mold, at least two different mold opening amounts can be held and the mold can be clamped. The heater is similar to the joint end surface of the first and second semi-molded products. It consists of a linear halogen heater or carbon heater formed in a single stroke, and when the heater is inserted between the parting surfaces that have been opened, it is discontinuous in two adjacent parts (E1, E2) When part (D) has occurred , The two locations of the portion (E1, E2) is inserted so that the vertical relationship in the vertical direction, retracting the hollow molded article manufacturing apparatus characterized by being freely provided.

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