JP4238094B2 - Large bulk material resin molding apparatus and molding method thereof - Google Patents

Description

  The present invention relates to a resin molding apparatus for a large bulk material and a molding method therefor.

When the keel part of a ship is supported so as not to be damaged, or when a heavy object is placed on the floor or ground of a factory, the keel part or heavy object is placed on a wooden square. The vertical, horizontal and length dimensions of the square bars are large because the mass of the object to be placed is remarkably large. For example, in the case of a ship, the dimensions are 35 cm, 35 cm and 120 cm, respectively. Obtaining such a size of timber from natural trees requires very large trees, and due to the decrease in natural timber resources, it is difficult to obtain a sufficient number of trees, which is costly. It is also expensive.
JP-A-9-155895

  In order to solve the problems of square bars, that is, large bulk materials as described above, those made of concrete or steel are adopted, but it is difficult to put into practical use in terms of production and cost, and the mass is excessive. There's a problem. Further, when molding a large bulk material with a synthetic resin material, the cross-sectional area of the product is excessive in normal continuous extrusion molding, and the molding is extremely difficult due to the large mass as continuous extrusion molding. In addition, the method of injection molding in a mold has a problem that since it has a large size as described above, a cavity is formed inside the product and cannot support the support of heavy objects.

  The present invention has been made in view of the circumstances as described above, and when molding a large bulk material with a synthetic resin material using a mold, bubbles and cavities are not substantially problematic inside the product. An object of the present invention is to provide a resin molding apparatus for large bulk materials which is greatly reduced.

In order to achieve the above object, a resin molding apparatus for a large bulk material according to the present invention is a resin molding of a large bulk material in which a mold for product molding is coupled to a material supply apparatus that delivers a synthetic resin material in a molten state. A device,
The cross section of the mold is a closed cross section, and its cross sectional shape is substantially constant in the length direction.
A supply port for supplying the synthetic resin material from the material supply device into the mold is provided at an end portion in the longitudinal direction of the mold,
The volume of the product molding part gradually increases in the mold while facing the supply port and maintaining the pressure of the molten synthetic resin material in the process of increasing the synthetic resin material supplied in the mold at a predetermined value or more. A pressure control member that moves in the direction of increasing is provided,
The pressure control member is coupled to a drive device that maintains the pressure above a predetermined value,
Further, the gist of the invention is that a cooling member having a tip portion extending in the longitudinal direction in the vicinity of the supply port is disposed in the mold so that the pressure control member can slide.

  In the large bulk material resin molding apparatus of the present invention, the cross section of the mold is a closed cross section and the cross sectional shape thereof is substantially constant in the length direction, and the synthetic resin material from the material supply apparatus is supplied into the mold. A supply port is provided at an end portion in the longitudinal direction of the mold, is opposed to the supply port, and the pressure of the synthetic resin material in a molten state while increasing the amount of the synthetic resin material supplied into the mold is a predetermined value or more. A pressure control member is provided that gradually moves in the mold in a direction in which the volume of the product forming portion increases.

  For this reason, at the initial stage of molding, the space volume of the product molding part between the inner end face of the mold and the pressure control member is small, so the synthesis of the molten state supplied into the mold at a predetermined pressure from the material supply device Immediately filled with resin. At this stage, the molten synthetic resin flows into the mold as a synthetic resin flow from the supply port, and is immediately received by the pressure control member. In this way, while the molten synthetic resin is cooled on the surface of the pressure control member, it changes direction toward the inner peripheral surface of the mold and flows in a radial direction, and is further received by the inner peripheral surface of the mold. Cools and hardens. Therefore, in the synthetic resin, a portion near the inner peripheral surface of the mold on the surface of the pressure control member is hardened in an early stage, and the hardening region is sequentially expanded in the central portion of the pressure control member. The uncured synthetic resin is pressurized at a predetermined pressure by the material supply device, and while receiving the pressure, the pressure control member gradually moves in the mold in the direction in which the volume of the product molding portion increases, The pressure of the synthetic resin is maintained at a predetermined value or higher. Accordingly, the curing is continued following the cured synthetic resin, and the continuous curing under pressure is performed, so that bubbles and cavities are significantly reduced.

  After the initial stage, the region of the cured portion is expanded while the pressure control member further moves in the above direction, and continuous curing under pressure continues. Even at this stage, since the molten synthetic resin is sequentially supplied into the mold, the uncured synthetic resin pressure is maintained at a pressure higher than a predetermined value by the gradual movement of the pressure control member, and bubbles and cavities are greatly reduced. The reduced hardening phenomenon continues. As the pressure control member moves, the cured synthetic resin follows the pressure control member while sliding on the inner surface of the mold.

When the continuous pressure supply of the synthetic resin in the molten state as described above and the controlled movement of the pressure control member reach the final stage, the pressure control member hits the other end surface inside the mold and stops. At this time, by continuing the pressurized state of the synthetic resin, bubbles and cavities are greatly reduced when the uncured part is cooled and cured, resulting in a dense and normal internal state over the entire product, and a high load is applied. A large bulk material that does not deform even is obtained.
In addition, the molten synthetic resin is cooled at the inner peripheral surface of the mold, and at the same time, the molten synthetic resin is cooled at the center of the product molding portion by contacting the cooling member. Therefore, the molten synthetic resin is cooled by both the inner peripheral surface of the mold and the cooling member, and such a cooling state is continuously maintained when the pressure control member is retracted, and is cooled from the inside and outside of the large bulk material. The Due to the continuous cooling phenomenon in the longitudinal direction of such a mold, the large bulk material is cured in a short time, so that the growth of bubbles and cavities is suppressed over the entire length, the density is made uniform, and it can withstand high loads. A shaped bulk material is obtained.

  In the present invention, “the pressure of the molten synthetic resin material is maintained at or above a predetermined value”, but the pressure above this predetermined value can greatly reduce the occurrence of bubbles, cavities, and the like. Means pressure. The appropriate pressure value may be set as appropriate depending on the required characteristics of the material to be used and the bulk material, but the set pressure value is set by the supply pressure of the material supply device and the pressure applied to the pressure control member.

  In the resin molding apparatus for a large bulk material of the present invention, the outer peripheral surface of the pressure control member slides on the inner peripheral surface of the mold, or the gap between the outer peripheral surface and the inner peripheral surface is a minute value. In this case, the molten synthetic resin that has flowed in does not leak from the outer peripheral portion of the pressure control member, and the product portion can be accurately molded. Furthermore, since the synthetic resin begins to harden from a position close to the inner peripheral surface of the mold that is in contact with the pressure control member, the cured portion serves as a seal member for the molten synthetic resin and prevents leakage of the molten synthetic resin. Therefore, even when the gap is slightly large, normal molding can be performed.

  In the large bulk resin molding apparatus of the present invention, when the pressure control member is coupled to a driving device that maintains the pressure at a predetermined value or higher, the supply pressure of the molten synthetic resin from the material supply device The pressure control member moves while the drive device backs up the pressure control member in opposition to the speed of increase in the mold of the molten synthetic resin. Therefore, the pressure of the molten synthetic resin can be maintained at a predetermined value or higher during the molding of large bulk materials, and there is much less bubbles and cavities when cooling and curing the uncured part, resulting in a dense and normal internal state throughout the product. A large bulk material that does not deform even when a high load is applied can be obtained.

  In the large bulk material resin molding apparatus of the present invention, when the driving device is a hydraulic cylinder connected to the pressure control device, the supply pressure of the molten synthetic resin from the material supply device and the molten synthetic resin The output of the hydraulic cylinder is set to an optimum value by the pressurizing control device in opposition to the increasing speed in the mold, and the pressure control member is operated while the output of the hydraulic cylinder having the optimum value backs up the pressure control member. Moving. Furthermore, since the environmental temperature, the type of synthetic resin, the melting temperature of the synthetic resin, etc. change due to seasonal changes, the curing speed of the synthetic resin is slow. It is possible to set an optimal moving speed suitable for the above-mentioned various change factors of the curing speed. Therefore, the pressure of the molten synthetic resin can be accurately maintained above the specified value during the molding of large bulk materials, and bubbles and cavities are greatly reduced when the uncured part is cooled and cured. Thus, a large bulk material that does not deform even when a high load is applied can be obtained.

In order to achieve the above object, the resin molding method for a large bulk material according to the present invention is a method for synthesizing a large bulk material in which a molten synthetic resin material is injected into a mold for product molding to mold the large bulk material. In the resin molding method, the pressure of the pressure control member inserted in the mold so as to be able to advance and retreat is maintained at a predetermined pressure or higher in the molten synthetic resin material while the amount of the synthetic resin material supplied into the mold is increasing. While gradually curing the synthetic resin material from the side closer to the pressure control member by gradually moving the inside of the mold in the direction of increasing the volume of the product molding part,
In the mold, a cooling member having a tip portion extending in the longitudinal direction close to the supply port is disposed so that the pressure control member can slide, and the cooling resin also cools the synthetic resin material. The gist.

  The resin molding method for a large bulk material according to the present invention is the pressure of the molten synthetic resin material in the process of increasing the amount of the synthetic resin material supplied into the mold by inserting the pressure control member inserted in the mold so as to be able to advance and retreat. The synthetic resin material is sequentially cured from the side closer to the pressure control member by gradually moving the inside of the mold in the direction in which the volume of the product molding portion is increased while maintaining the value above a predetermined value.

  For this reason, at the initial stage of molding, the space volume of the product molding part between the inner end face of the mold and the pressure control member is small, so the synthesis of the molten state supplied into the mold at a predetermined pressure from the material supply device Immediately filled with resin. At this stage, the molten synthetic resin is immediately received by the pressure control member in a flow state that strikes the pressure control member directly. In this way, while the molten synthetic resin is cooled on the surface of the pressure control member, it changes direction toward the inner peripheral surface of the mold and flows in a radial direction, and is further received by the inner peripheral surface of the mold. Cools and hardens. Therefore, in the synthetic resin, a portion near the inner peripheral surface of the mold on the surface of the pressure control member is hardened in an early stage, and the hardening region is sequentially expanded in the central portion of the pressure control member. The uncured synthetic resin is pressurized at a predetermined pressure by the material supply device, and while receiving the pressure, the pressure control member gradually moves in the mold in the direction in which the volume of the product molding portion increases, The pressure of the synthetic resin is maintained at a predetermined value or higher. Accordingly, the curing is continued following the cured synthetic resin, and the continuous curing under pressure is performed, so that bubbles and cavities are significantly reduced.

  After the initial stage, the region of the cured portion is expanded while the pressure control member further moves in the above direction, and continuous curing under pressure continues. Even at this stage, since the molten synthetic resin is sequentially supplied into the mold, the uncured synthetic resin pressure is maintained at a pressure lower than a predetermined value by the gradual movement of the pressure control member, and bubbles and cavities are greatly reduced. The curing phenomenon continues to decrease. As the pressure control member moves, the cured synthetic resin follows the pressure control member while sliding on the inner surface of the mold.

When the continuous pressure supply of the synthetic resin in the molten state as described above and the controlled movement of the pressure control member reach the final stage, the pressure control member stops by hitting the other end surface or the like inside the mold. At this time, by continuing the pressurized state of the synthetic resin, there is much less bubbles and cavities when cooling and curing the uncured part, and the product is in a dense and normal internal state throughout the product, even if a high load is applied A large bulk material that does not deform is obtained.
In addition, the molten synthetic resin is cooled at the inner peripheral surface of the mold, and at the same time, the molten synthetic resin is cooled at the center of the product molding portion by contacting the cooling member. Therefore, the molten synthetic resin is cooled by both the inner peripheral surface of the mold and the cooling member, and such a cooling state is continuously maintained when the pressure control member is retracted, and is cooled from the inside and outside of the large bulk material. The Due to the continuous cooling phenomenon in the longitudinal direction of such a mold, the large bulk material is cured in a short time, so that the growth of bubbles and cavities is suppressed over the entire length, the density is made uniform, and it can withstand high loads. A shaped bulk material is obtained.

  Next, the best mode for carrying out the present invention will be described.

  In the following description, the cross section of the mold is a closed cross section, the cross sectional shape thereof is substantially constant in the length direction, and the supply port for supplying the synthetic resin material from the material supply device into the mold is the end in the longitudinal direction of the mold. Product in the mold gradually while maintaining the pressure of the synthetic resin material in the molten state facing the supply port and in the middle of increasing the amount of the synthetic resin material supplied into the mold at a predetermined value or more. A pressure control member that moves in a direction in which the volume of the molding part increases is provided, and the pressure control member is coupled to a drive device that maintains the pressure at a predetermined value or more. The hydraulic cylinder is connected to the device.

1 to 3 show an Example of the resin molding apparatus of a large form bulk material.

  FIG. 1 is a cross-sectional view showing the entire structure of a large bulk resin molding apparatus, FIG. 2 is a cross-sectional view of [2]-[2] in FIG. 1, and FIG. It is sectional drawing which shows the change state which becomes large within a type | mold.

  The entire large bulk material resin molding apparatus is denoted by reference numeral 1, and the apparatus 1 is a material supply apparatus 2 for sending out a synthetic resin material, and a large type in which a molten synthetic resin is supplied from the material supply apparatus 2. It comprises a mold 3 for forming a bulk material, and a drive device 4 that is output-controlled by a pressure control device and connected to the die 3.

  Although various types of materials can be adopted as the material supply device 2, here, it is an injection molding device generally used. In this injection molding apparatus, a long screw 6 is inserted into a supply cylinder 5 having a circular cross section, and a feed rotation is applied to the screw 6 by a rotation driving device 7. A heater 8 for melting the synthetic resin material is attached to the outer periphery of the supply cylinder 5. A hopper 9 is provided at the end of the supply cylinder 5 to store a synthetic resin material such as pellets or a filler and supply the material into the supply cylinder 5. A nozzle plate 10 is attached to the other end of the supply cylinder 5, and molten synthetic resin is extruded from a number of openings 11 provided in the nozzle plate 10.

  A relay pipe 12 is connected to the nozzle plate 10, and synthetic resin is supplied into the mold 3 through the relay pipe 12. The mold 3 has a closed cross section, and its cross sectional shape and cross sectional dimensions are substantially constant in the length direction. A circular supply port 13 for supplying the synthetic resin material from the relay pipe 12 into the mold 3 3 at the end in the longitudinal direction. As shown in FIG. 2, the mold 3 is made of a thick steel plate and has a substantially square cross-sectional shape. A substantially square end plate 14 is disposed at the end of the mold 3, and the supply port 13 is provided at a substantially central portion thereof.

  The pressure control which receives the synthetic resin which flowed in into the type | mold 3 from the said supply port 13, maintains the pressure of the synthetic resin of a molten state more than predetermined value, and comprises the product shaping | molding part 15 between the end plates 14 A member 16 is provided. The pressure control member 16 has a substantially square shape similar to the cross-sectional shape of the mold 3, and a minute gap C is formed between the outer peripheral surface 17 and the inner peripheral surface 3 </ b> A of the mold 3. The pressure control member 16 is arranged as described above, and the pressure of the synthetic resin material in a molten state is increased to a predetermined value or more while facing the supply port 13 and in the process of increasing the amount of the synthetic resin material supplied into the mold 3. While maintaining, the inside of the mold 3 is gradually moved in the direction in which the volume of the product molding portion 15 is increased.

  The end plate 14 or the end plate 18 on the opposite side to the end plate 14 can be removed in order to complete the forming of the large bulk material and extract it from the mold 3. In this example, the end plate 18 can be removed, and the flange 19 provided on the end plate 18 side and the flange 20 provided on the main body side of the mold 3 are abutted to separate the abutting portion. The end of the mold 3 is opened. Further, the synthetic resin is injected while the abutting portion is in close contact. In order to reliably maintain the abutting state of the abutting portion, the clamp mechanisms 21 are arranged at a plurality of positions on the flanges 19 and 20 at equal intervals. The clamp mechanism 21 is of a type that is generally used. In this example, the clamp mechanism 21 includes a shaft member 22 that passes through both flanges 19 and 20 and a clamp lever 23 coupled thereto. The state shown in FIG. 1 is a state in which the clamp lever 23 is stopped at the tightening position and the flanges 19 and 20 are in close contact with each other. Further, when the clamp lever 23 is rotated to loosen the tightening state and the shaft member 22 is removed from both the flanges 19 and 20, the end plate 18 can be opened.

  Even when the end plate 14 on the side where the supply port 13 is opened is attached or detached, a clamp mechanism similar to that on the end plate 18 side is employed.

  Next, a drive shaft 24 is coupled to the central portion of the pressure control member 16, and the drive shaft 24 passes through the bearing portion 25 of the end plate 18 and is coupled to the drive device 4. As the driving device 4, a hydraulic cylinder 26 is used. The pressure control member 16 is opposed to the pressure of the molten synthetic resin introduced from the material supply device 2, and the pressure control member 16 is moved at a predetermined speed to the product molding unit. In order to move in the direction in which the pressure increases, a pressure control device 27 is provided. The pressure control device 27 is a normal device capable of operating a pressure control valve by using a means for converting the pressure signal of the molten synthetic resin of the product molding unit 15. The hydraulic pressure transmitted to is set in accordance with the pressure of the molten synthetic resin by the pressure control valve.

  In order to maintain the pressure of the molten synthetic resin in the course of increasing to a predetermined value or more, it is performed by setting the moving speed of the pressure control member 16 in accordance with the increasing amount of the molten synthetic resin per unit time. That is, by setting the moving speed of the pressure control member 16 slightly slower than the increase amount, the molten synthetic resin is always put in a compressed state. In order to set the moving speed of the pressure control member 16 as described above, a predetermined throttle resistance is given to the hydraulic oil moving from the right side to the left side of the hydraulic piston 28 shown in FIG. Is performed by the pressure control device 27.

  Although the cross-sectional shape of the mold 3 is substantially square, it can be a circular cross-section, a rectangular cross-section, a trapezoidal cross-section, or the like according to the shape of the large bulk material. Further, the gap C can be further reduced so that the outer peripheral surface 17 slides on the inner peripheral surface 3A of the mold 3. Furthermore, although the hydraulic cylinder 26 is employed as the driving device 4, it can be replaced with an electric motor or the like.

  Next, as the type of synthetic resin, various synthetic resins can be used as long as they can withstand the compressive load on the large bulk material. In this example, the waste material of olefin resin (polypropylene) is particulate. What was made and wood powder as a filler were mixed and put into the hopper 9. The mixing ratio of the synthetic resin waste material and wood powder is 60% of the waste material and 40% of the wood powder in weight%. In addition, about the said synthetic resin and a filler, according to the pressure | voltage resistant performance of a large-sized bulk material, a magnitude | size, etc., the kind of synthetic resin selected, a filler, and the mixture ratio of both are set.

  FIG. 3 shows a state in which the synthetic resin flowing into the product molding portion 15 is cured while maintaining a predetermined pressure. FIG. 4A shows the initial stage of molding in which the volume of the product molding unit 15 is minimized. At this stage, the molten synthetic resin flowing in from the supply port 13 strikes the center of the end face of the pressure control member 16 and flows in the radial direction while being cooled by the pressure control member 16. Thereafter, the synthetic resin is received by the inner peripheral surface 3A of the mold 3 and further cooled there. By such an initial synthetic resin flow phenomenon, curing starts from the inner peripheral surface 3A of the mold 3 close to the pressure control member 16, and subsequently, the curing region expands toward the central portion of the pressure control member 16. Go. Then, since the molten synthetic resin sequentially flows in, the pressure control member 16 is gradually moved to the right while facing it, and the pressure of the molten synthetic resin is substantially the same as or higher than the supply pressure of the material supply device 2. Maintained at slightly lower pressure. In FIG. 3, 29 is an uncured portion where the synthetic resin is in a molten state, and 30 is a cured portion.

  At the stage of FIG. 3 (B), the area of the cured portion 30 is enlarged, and the uncured portion 29 is an area larger than (A). Even at this stage, since the moving speed of the pressure control member 16 is a slow speed that suppresses an increase in the volume of the product molding portion 15, the pressure of the uncured portion 29 is substantially the same as the supply pressure of the material supply device 2. Or at a slightly lower pressure.

  At the stage of FIG. 3C, the capacity of the uncured portion 29 is the same as that in FIG. 3B, but the cured portion 30 is increased and the cured product portion is further enlarged. Also in this stage, the pressure of the uncured portion 29 is in the same pressure state as in the stage shown in (B) above.

Conditions for setting the pressure of the uncured portion 29 include the volume of the product molding portion 15, the viscosity of the synthetic resin, the degree of cooling of the mold 3, etc. In this example, the supply pressure of the material supply device 2 is 1500 kg. ^{/ cm 2 (14709.975 × 10 -4} Pa), the pressure of the hydraulic cylinder opposite to the 1500 Kg / cm ² is ^{800Kg / cm 2 (7845.32 × 10} -4 Pa). The ratio of the two pressures is in the range of 10: 5 to 10: 9.

  When the synthetic resin is cured in the mold 3, the clamp mechanism 21 is operated to remove the end plate 18, and then the mold 3 is separated from the relay pipe 12, and the mold 3 is lifted up and down to cure and shrink. Pull out the large bulk material. Alternatively, by providing an opening function like the end plate 18 on the end plate 14 side, a large bulk material can be extruded from the mold 3 by the pressing output of the hydraulic cylinder 26, and workability is improved. Moreover, workability can be improved by applying a release agent to the inner surface of the mold 3 in order to facilitate extraction of the large bulk material as described above.

It is as follows when the effect by the structure of said reference example is listed.

  At the initial stage of molding, since the space volume of the product molding portion 15 between the inner end face of the mold 3, that is, the end plate 14 and the pressure control member 16 is small, the material supply device 2 supplies the mold 3 with a predetermined pressure. Immediately filled with the melted synthetic resin. At this stage, the molten synthetic resin flows into the mold 3 as a synthetic resin flow from the supply port 13 and is immediately received by the pressure control member 16. In this way, the molten synthetic resin is cooled on the surface of the pressure control member 16, changes its direction toward the inner peripheral surface 3 </ b> A of the mold 3, and flows in a radial direction. It is received by the surface 3A, cooled and hardened. Therefore, the synthetic resin is hardened at an early stage at a portion close to the mold inner peripheral surface 3 </ b> A on the surface of the pressure control member 16, and the hardening region is gradually expanded in the central portion of the pressure control member 16. The uncured synthetic resin is pressurized at a predetermined pressure by the material supply device 2, and the pressure control member 16 gradually moves in the mold 3 in the direction in which the volume of the product molding portion 15 increases while receiving the pressure. The pressure of the uncured synthetic resin is maintained at a predetermined value or higher. Accordingly, the curing is continued following the cured synthetic resin, and the continuous curing under pressure is performed, so that bubbles and cavities are significantly reduced.

  After the initial stage, the region of the cured portion 30 is expanded while the pressure control member 16 is further moved in the above direction, and continuous curing under pressure continues. Also in this stage, since the molten synthetic resin is sequentially supplied into the mold 3, the uncured synthetic resin pressure is maintained at a predetermined value or more by the gradual movement of the pressure control member 16, and bubbles and cavities are greatly increased. The curing phenomenon continues to decrease. As the pressure control member 16 moves, the cured synthetic resin follows the pressure control member 16 while sliding on the inner peripheral surface 3A of the mold 3.

  When the continuous pressure supply of the synthetic resin in the molten state as described above and the controlled movement of the pressure control member 16 reach the final stage, the pressure control member 16 hits the other end surface inside the mold and stops. At this time, by continuing the pressurized state of the synthetic resin, bubbles and cavities are greatly reduced when the uncured portion 29 is cooled and cured, resulting in a dense and normal internal state throughout the product, and a high load is applied. A large bulk material that does not deform even is obtained.

  A sliding relationship or a minute gap C is set between the outer peripheral surface 17 of the pressure control member 16 and the inner peripheral surface 3A of the mold 3. Therefore, the molten synthetic resin that has flowed in does not leak from the outer peripheral surface 17 of the pressure control member 16, and the product portion can be accurately molded. Further, since the synthetic resin begins to harden from a location near the inner peripheral surface 3A of the mold 3 that is in contact with the pressure control member 16, the cured portion 30 serves as a sealing member for the molten synthetic resin, and leaks the molten synthetic resin. To prevent. Therefore, even when the gap C is slightly large, normal molding can be performed.

  Since the pressure control member 16 is operated by the driving device 4, the driving device 4 is opposed to the supply pressure of the molten synthetic resin from the material supply device 2 and the increasing speed of the molten synthetic resin in the mold 3. The pressure control member 16 moves while backing up the pressure control member 16. Therefore, the pressure of the molten synthetic resin can be maintained at a predetermined value or more during the molding of the large bulk material, and bubbles and cavities are greatly reduced when the uncured portion 29 is cooled and cured, and the product is dense and normal throughout the entire product. A large bulk material that is in an internal state and does not deform even when a high load is applied can be obtained.

  Since the drive device 4 is a hydraulic cylinder 26 connected to the pressure control device 27, the drive pressure of the molten synthetic resin from the material supply device 2 and the increasing speed of the molten synthetic resin in the mold 3 are opposed to each other. The output of the hydraulic cylinder 26 is set to an optimum value by the pressure control device 27, and the pressure control member 16 moves while the output of the hydraulic cylinder 26 having the optimum value backs up the pressure control member 16. Furthermore, since the environmental temperature, the type of synthetic resin, the melting temperature of the synthetic resin, and the like change due to seasonal changes and the like, the synthetic resin is cured at a slow rate. It is possible to set an optimum moving speed in which the moving speed of 16 is adapted to the change factors of the above various curing speeds. Accordingly, the pressure of the molten synthetic resin can be accurately maintained at a predetermined value or more during the molding of the large bulk material, and bubbles and cavities are greatly reduced when the uncured portion 29 is cooled and cured, so that the entire product is dense. A large bulk material that is in a normal internal state and does not deform even when a high load is applied can be obtained.

  As mentioned above, since the synthetic resin is cured under pressurized conditions, even if the waste material of the thermoplastic plastic synthetic resin is granulated and reused, it cures at a high density so that bubbles and cavities do not become a problem. This is advantageous for cost reduction. Moreover, since fillers such as wood powder are also mixed in the synthetic resin cured under the pressure conditions as described above, the compressive strength of the large bulk material due to mixing of the fillers is not reduced.

  If the retreat speed of the pressure control member 16 is made constant over the entire length of the mold 3, the pressure of the product molding portion 15 does not become sufficiently high at the initial stage of injection of the molten synthetic resin. A phenomenon occurs in which the distribution exceeds the reference value. On the other hand, in the state in which the pressure control member 16 is retracted to the final position, the pressure of the molten synthetic resin is stably set to a predetermined value or higher, so that the bubbles and the like that are cured in the final stage are less than the reference value. Become. Since the distribution of bubbles and the like can vary in the vicinity of both ends of the large bulk material in this way, the large bulk material having the uniform distribution of bubbles and cavities over the entire length by truncating the both ends as necessary. Finish.

Figures 4-8 show the Kazumi施例the resin molding apparatus of large bulk material of the present invention.

  In this embodiment, the density in the longitudinal direction of the molded large bulk material is made as uniform as possible, and the cooling property during and after molding is improved.

  FIG. 4 is a cross-sectional plan view mainly showing the internal structure of the mold 3. The pressure control member 16 has a double structure in which a front plate 16A and a rear plate 16B are arranged at an interval, and the front plate 16A and the rear plate 16B are integrated at a connecting portion 16C at the center. In this example, two drive shafts 24 are arranged in parallel, one end of which is coupled to the support plate 31 and the other end is coupled to the pressure control member 16. The support plate 31 is coupled to the piston rod 32 of the hydraulic cylinder 26. In addition, the drive shaft 24 and the pressure control member 16 can be connected by a so-called screw structure of a male screw portion formed at the end of the drive shaft 24 and a nut screwed to the male screw portion. The drive shaft 24 is slidably penetrated through the rear plate 16B, and the front end thereof is abutted against the back surface of the front plate 16A.

  A steel cooling pipe 33 is disposed in a substantially central portion of the mold 3 over the longitudinal direction of the mold 3. The cooling pipe 33 passes through an insertion hole 16D formed in the connection portion 16C of the pressure control member 16 in a slidable state, and a rear portion is guided by a guide hole 34 formed in the end plate 18. The guide hole 34 includes a large-diameter portion 34A that supports the cooling pipe 33 in the center, and a passage portion 34B through which the drive shaft 24 passes on both sides of the large-diameter portion 34A. As shown in FIG. 6, two bolts 36 pass through a stopper plate 35 that receives the rear end of the cooling pipe 33, and the front end side is screwed into the end plate 18.

  As shown in FIG. 8, the cooling pipe 33 is a hollow pipe having a circular cross section and having a hollow portion 33A. A tapered portion 33B is provided at the tip of the cooling tube 33 to close the hollow portion 33A. . The diameter of the cooling pipe 33 is set larger than the inner diameter of the supply port 13. In this example, the diameter of the cooling pipe 33 is 90 mm and the inner diameter of the opening of the supply port 13 is 80 mm. Further, the position where the cooling pipe 33 is most retracted is a position where the tip of the tapered portion 33B has entered the supply port 13, and the flow path 37 through which the synthetic resin material flows into the mold 3 at this position. Is formed. As shown in FIG. 7, the flow path 37 has a shape of an annular flow space, and the flow path width is indicated by a symbol W. In order to make the central axis of the tapered portion 33B coincide with the central axis of the supply port 13, a receiving member 38 having a "<" shape in cross section is disposed below the cooling pipe 33 and welded to the inner surface of the end plate 14. It is.

  When the bolt 36 is tightened, the stopper plate 35 moves toward the end plate 18, so that the cooling pipe 33 is pushed toward the supply port 13 and the tapered portion 33 </ b> B is pressed against the opening edge of the supply port 13. The Therefore, the tapered portion 33B and the opening edge of the supply port 13 serve as a valve.

As described above, in this example, the diameter of the cooling pipe 33 is 90 mm and the inner diameter of the opening of the supply port 13 is 80 mm. On the other hand, the internal dimensions of the mold 3 are 350 mm in length and width, and 1700 mm in length. It is. Other than that, it is the same as that of the above-mentioned reference example, and the same numerals are given to the same portion. In addition, it is convenient to collect large bulk materials for ships in order to recover large bulk materials so that the ships float after launch, and it is also advantageous to be lightweight when transported on the ground. is there. From such a viewpoint, the specific gravity of the large bulk material is set to 1 g / cc or less, preferably 0.5 g / cc close to natural wood. Such setting of specific gravity is adjusted according to the type of synthetic resin to be used, the type of filler, and the mixing amount.

  With the above configuration, the molten synthetic resin material flows into the product molding portion 15 from the annular flow path 37. The flow form of the molten synthetic resin at this time is a flow diffused in a substantially tapered shape due to the shape of the tapered portion 33B, and the main flow is directed toward the inner peripheral surface 3A of the die 3. Therefore, the molten synthetic resin is cooled by the inner peripheral surface 3 </ b> A of the mold 3. At the same time, the molten synthetic resin is cooled at the center of the product molding portion 15 by contacting the cooling pipe 33. Therefore, the molten synthetic resin is cooled by both the inner peripheral surface 3A of the mold 3 and the cooling pipe 33, and such a cooling state is continuously maintained when the pressure control member 16 is retracted, and the inside of the large bulk material Cooled from the outside. Due to the continuous cooling phenomenon in the longitudinal direction of the mold 3, the large bulk material is cured in a short time, so that the growth of bubbles and cavities is suppressed over the entire length, the density is made uniform, and it can withstand high loads. Large bulk material is obtained.

  When the pressure control member 16 retreats most and the product molding portion 15 is filled with the uncured portion 29 and the cured portion 30, the bolt 36 is tightened to move the cooling pipe 33 toward the supply port 13, and the tapered portion 33B is moved. It is seated on the opening edge of the supply port 13. As a result, the molten synthetic resin continuous from the supply port 13 to the product molding portion 15 is cut, and the supply of the molten synthetic resin from the material supply device 2 is terminated. Thereafter, when the entire product molding portion 15 is cured, the clamp mechanism 21 is released, the end plate 18 is removed from the mold 3, and the drive shaft 24 is further retracted to extract the pressure control member 16 from the mold 3. As a result, a large bulk material and a cooling pipe passing therethrough remain in the mold 3. Thereafter, the large bulk material is pulled out from the mold 3 by grasping the rear end of the cooling pipe 33. Furthermore, the cooling pipe 33 is extracted from the large bulk material to be in a state of a single molded product.

  As described above, when the molten synthetic resin is supplied to the product molding portion 15, the heat of the molten synthetic resin is dissipated through the hollow portion 33A of the cooling pipe 33, and the curing of the synthetic resin is promoted. The generation of parts can be greatly reduced. Also. After the cooling pipe 33 is extracted from the large bulk material, the through holes formed in the large bulk material are useful for heat dissipation and effective in promoting air cooling.

  In addition, as described above, the cooling pipe 33 that performs the cooling function performs the valve function that blocks the inflow of the molten synthetic resin, which is effective in simplifying the structure by making the cooling pipe 33 multifunctional.

  Since the cooling pipe 33 has a hollow structure, it can perform a cooling function over its entire length, and continuous cooling can be performed as the pressure control member 16 moves backward. Further, since the pressure of the molten synthetic resin acts on the cooling pipe 33, the rear end portion is pressed against the stopper plate 35, whereby the relative position between the tapered portion 33 </ b> B and the opening edge of the supply port 13. That is, the flow path width W is accurately set, and an appropriate flow of molten synthetic resin into the product molding portion 15 is obtained.

  When the pressure control member 16 moves backward, the tip of the cooling pipe 33 is cantilevered and displaced downward by its own weight, and the central axis of the tapered portion 33B and the central axis of the supply port 13 may be displaced. However, since the receiving member 38 is provided, the center line as described above is not shifted, the flow path width W is also maintained in a uniform state in the circumferential direction, and a good inflow of molten synthetic resin can be secured. Although it is conceivable that the presence of the receiving member 38 disturbs the flow of the molten synthetic resin, the influence on the flow can be reduced by reducing the size of the receiving member 38 or circulating the gap 38A shown in FIG. Can be minimized.

  As shown in FIG. 6, it is possible to further enhance the cooling effect by opening the vent hole 39 in the stopper plate 35 to promote the heat radiation from the hollow portion 33A. Further, the cooling performance can be further improved by supplying cooling air from the vent hole 39. Alternatively, although not shown, the cooling pipe 33 can be water-cooled.

  The guide hole 34 formed in the end plate 18 includes a large-diameter portion 34A that allows the cooling pipe 33 to pass therethrough and a passage portion 34B that allows the driving shaft 24 to pass. Can be easily arranged.

  Further, since the drive shaft 24 is coupled to the pressure control member 16 so as to back up the pressure control member 16, and the cooling pipe 33 passes through the insertion hole 16D of the pressure control member 16, the molten synthetic resin Is supplied to the product molding part 15 and the moving operation when the pressure control member 16 is gradually retracted becomes smooth, and no abnormal mechanical resistance is generated. Therefore, a factor that disturbs the pressure state of the molten synthetic resin is removed, and a pressure equal to or higher than a predetermined value is accurately maintained.

  It is desirable to close the supply port 13 with the tapered portion 33B after the volume of the uncured portion 29 is reduced as much as possible. By closing the supply port 13 at such a time, condensation when the uncured portion 29 is cured can be reduced, and the molded shape can be accurately formed.

Figure 9 shows a second embodiment of the resin molding apparatus of large bulk material of the present invention.

In this embodiment, the pressurizing pump 40 is arranged on the upstream side of the supply port 13. As the pressurizing pump 40, a gear pump capable of adjusting the extrusion pressure is employed. Otherwise, the same as the above you施例, are denoted by the same reference numerals to like parts.

With the above configuration, since the supply pressure of the molten synthetic resin into the mold 3 can be adjusted, the pressure state of the uncured portion 29 can be controlled more accurately, and the generation of bubbles and cavities can be minimized. Can do. The pressure of the uncured portions 29 of the upper you施例is the supply pressure of the material supply device 2 is substantially the same or slightly lower pressure than, by arranging the pressure pump 40, uncured portions 29 Can be set to a value higher than the supply pressure of the material supply device 2, which is effective in minimizing the generation of bubbles and cavities. Otherwise, the same effects as above you施例.

  Further, according to the method for molding a large bulk material according to the present invention, at the initial stage of molding, the space volume of the product molding portion 15 between the inner end face of the mold 3, that is, the end plate 14 and the pressure control member 16, is small. Therefore, it is immediately filled with the molten synthetic resin supplied into the mold 3 from the material supply device 2 at a predetermined pressure. At this stage, the molten synthetic resin is immediately received by the pressure control member 16 in a flow state that strikes the pressure control member 16 directly. In this way, the molten synthetic resin is cooled on the surface of the pressure control member 16, changes its direction toward the inner peripheral surface of the mold 3 and flows in a radial direction, and further the inner peripheral surface of the mold 3. It is received and cooled and hardened. Therefore, the synthetic resin is hardened at an early stage at a portion close to the inner peripheral surface of the mold on the surface of the pressure control member 16, and the hardening region is sequentially expanded in the central portion of the pressure control member 16. The uncured synthetic resin is pressurized at a predetermined pressure by the material supply device 2, and the pressure control member 16 gradually moves in the mold in the direction in which the volume of the product molding portion 15 increases while receiving the pressure. The pressure of the uncured synthetic resin is maintained at a predetermined value or higher. Accordingly, the curing is continued following the cured synthetic resin, and the continuous curing under pressure is performed, so that bubbles and cavities are significantly reduced.

  After the initial stage, the region of the cured portion 30 is expanded while the pressure control member 16 is further moved in the above direction, and continuous curing under pressure continues. Even in this stage, since the molten synthetic resin is sequentially supplied into the mold, the uncured synthetic resin pressure is maintained at a predetermined value or more by the gradual movement of the pressure control member 16, and bubbles and cavities are greatly reduced. The curing phenomenon continues to decrease. As the pressure control member 16 moves, the cured synthetic resin follows the pressure control member 16 while sliding on the inner surface of the mold 3.

  When the continuous pressure supply of the synthetic resin in the molten state as described above and the controlled movement of the pressure control member 16 reach the final stage, the pressure control member 16 hits the other end surface inside the mold and stops. At this time, by continuing the pressurized state of the synthetic resin, bubbles and cavities are greatly reduced when the uncured portion 29 is cooled and cured, resulting in a dense and normal internal state over the entire product, and a high load is applied. A large bulk material that does not deform even if it is obtained.

  When manufacturing large bulk materials by resin molding, the generation of internal bubbles and cavities is virtually eliminated, and it can be effectively used as a support member for heavy objects such as ships and machine tools, and can be used in a wide range of industrial fields. It is.

It is sectional drawing which shows the whole structure of the apparatus which shows the reference example of this invention. It is [2]-[2] sectional drawing of FIG. It is sectional drawing which shows the state in which a product is shape | molded later on in order. It is a cross-sectional top view which shows the whole structure inside the type | mold which shows 1st Example of this invention. It is [5]-[5] sectional drawing of FIG. It is sectional drawing which shows the operation | movement structure of a cooling pipe. It is a side view which shows the front-end | tip part of a cooling pipe. It is [8]-[8] sectional drawing of FIG. It is a fragmentary sectional view showing the 2nd example of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Large bulk material resin molding apparatus 2 Material supply apparatus 3 Type | mold 3A Inner peripheral surface 4 Drive apparatus 5 Supply cylinder 6 Screw 7 Rotation drive apparatus 8 Heater 9 Hopper 10 Nozzle plate 11 Opening 12 Relay pipe 13 Supply port 14 End plate 15 Product forming portion 16 Pressure control member 16A Front plate 16B Rear plate 16C Connection portion 16D Insertion hole 17 Outer peripheral surface 18 End plate C Gap 19 Flange 20 Flange 21 Clamp mechanism 22 Shaft member 23 Clamp lever 24 Drive shaft 25 Bearing portion 26 Hydraulic cylinder 27 Pressure control device 28 Hydraulic piston P Hydraulic pump 29 Uncured portion 30 Cured portion 31 Support plate 32 Piston rod 33 Cooling tube 33A Hollow portion 33B Tapered portion 34 Guide hole 34A Large diameter portion 34B Passing portion 35 Stopper plate 36 Bolt 37 Flow path W Channel width 38 Receiving member 38A Cavity 39 Ventilation hole 40 Pressure pump

Claims (5)

A large-bulk resin molding device in which a mold for product molding is coupled to a material supply device that delivers a synthetic resin material in a molten state,
The cross section of the mold is a closed cross section, and its cross sectional shape is substantially constant in the length direction.
A supply port for supplying the synthetic resin material from the material supply device into the mold is provided at an end portion in the longitudinal direction of the mold,
The volume of the product molding part gradually increases in the mold while facing the supply port and maintaining the pressure of the molten synthetic resin material in the process of increasing the synthetic resin material supplied in the mold at a predetermined value or more. A pressure control member that moves in the direction of increasing is provided ,
The pressure control member is coupled to a drive device that maintains the pressure above a predetermined value,
Further, in the mold, a cooling member having a distal end extending in the longitudinal direction close to the supply port is disposed so that the pressure control member is slidable . Resin molding equipment.   2. The large bulk material according to claim 1, wherein an outer peripheral surface of the pressure control member slides on an inner peripheral surface of the mold or a gap between the outer peripheral surface and the inner peripheral surface is set to a minute value. Resin molding equipment. A taper is provided at the tip of the cooling member, and the cooling member is disposed at a position where the tip of the taper enters the supply port, so that resin flows between the opening edge of the supply port and the taper. An apparatus for molding a large bulk material according to claim 1 or 2, wherein an annular inflow space is formed . The cooling member is moved to the supply port side after injection of the synthetic resin material, and a tapered portion is seated on the opening edge of the supply port so that the supply of the molten supply resin can be aborted. The large bulk material resin molding apparatus as described in the item . A large bulk synthetic resin molding method in which molten synthetic resin material is injected into a mold for product molding to form a large bulk material. The pressure control is inserted into the mold in a state where it can be advanced and retracted. While maintaining the pressure of the synthetic resin material in a molten state in the course of increasing the amount of the synthetic resin material supplied into the mold at a predetermined value or more, the member is gradually moved in the mold in the direction in which the volume of the product molding part increases. When curing synthetic resin materials sequentially from the side closer to the pressure control member ,
In the mold, a cooling member having a tip portion extending in the longitudinal direction close to the supply port is disposed so that the pressure control member can slide, and the cooling resin also cools the synthetic resin material. A synthetic resin molding method for large bulk materials.

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