JP4748365B2 - Method and apparatus for molding fiber reinforced resin molded product - Google Patents

Description

  The present invention plasticizes and kneads resin and reinforcing fibers and injects a physical foaming agent in an injection cylinder with a built-in screw, and injects the mixture into a mold cavity to form a fiber reinforced resin molded product. The present invention relates to a method and apparatus.

  Conventionally, as a molding technology for foamed resin molded products, plastic (synthetic resin) is plasticized (melted) in an injection cylinder with a built-in screw, and a supercritical fluid such as nitrogen or carbon dioxide is used as a physical foaming agent. (Super Critical Fluid: SCF) is injected, and this SCF-mixed plasticized resin is injected into the mold cavity and finely foamed by releasing the pressure. ing.

  In recent years, in order to further reduce the weight of foamed resin molded products and improve the strength and rigidity, fiber reinforced resin molded products in which reinforcing fibers such as carbon fibers and glass fibers are mixed are used frequently. Yes, as a molding technology for this fiber reinforced resin molded product, plastic and kneading resin and reinforced fiber in injection cylinder and injecting SCF, and injecting the mixture into the cavity of the molding die, fiber reinforced resin molded product The technique which shape | molds is put to practical use (refer patent document 1).

  In the molding apparatus of Patent Document 1, a check ring for backflow prevention is provided in the central portion in the longitudinal direction of the screw, and in the injection cylinder, the raw material of the resin and the reinforcing fiber is supplied to the rear portion of the check ring. The resin and the reinforcing fiber are introduced into the front side portion of the check ring while being plasticized and kneaded, and SCF is injected into the portion where the screw near the front side of the check ring exists. The screw moves backward and rotates from the injection completion position, the mixture (resin, reinforcing fiber, SCF) is introduced into the resin reservoir on the front side of the screw in the injection cylinder, and after the predetermined amount of the mixture is accumulated, the screw advances. Is injected into the mold cavity.

  Incidentally, as shown in FIG. 14, in a molding apparatus 100 in which SCF is injected into a portion of the injection cylinder 101 where the screw 102 is present on the front side of the check ring 103 and on the rear side of the resin reservoir 104. In order to perform proper foaming with SCF, it is necessary to knead SCF with resin securely, and to maintain the mixture (resin, reinforcing fiber, SCF) at high pressure and inject it into the mold cavity Therefore, a backflow prevention structure 105 that prevents the SCF from flowing back to the upstream side for supplying the raw materials of the resin and the reinforcing fiber is necessary.

This backflow prevention structure 105 is provided with a labyrinth structure 105a in which the flow path of the resin becomes a labyrinth in a portion upstream of the SCF injection position in the screw 102 to prevent the backflow of SCF together with the resin. ing.
JP 2005-1388 A

  In the molding apparatus of Patent Document 1, a check ring for backflow prevention is provided in the central portion in the longitudinal direction of the screw, and SCF is injected into the portion where the screw near the front side of the check ring exists in the injection cylinder. Since the internal pressure in the vicinity of the SCF injection position becomes very high and acts on the check ring, there is a concern that SCF and resin may flow back upstream from the check ring. Therefore, the mixture (resin, reinforcing fiber, SCF) is high pressure. However, there is a possibility that proper foaming by SCF cannot be performed by injecting into the cavity of the molding die.

  Therefore, as shown in FIG. 14, by adopting a backflow prevention structure having a labyrinth structure, SCF and resin backflow can be reliably prevented. However, in the injection cylinder, a resin is disposed upstream of the labyrinth structure. Since the reinforcing fiber raw material is supplied, the reinforcing fiber passes through the maze structure. At that time, the reinforcing fiber is damaged (broken) by the maze structure, and the fiber reinforced resin having the desired strength and rigidity. There arises a problem that the molded product cannot be molded.

  Further, in the molding apparatus of Patent Document 1, the SCF injection portion is fixedly provided in the injection cylinder, and the injection position is only one position in the length direction of the injection cylinder. There is a possibility that it cannot be performed reliably.

  An object of the present invention is to plasticize and knead resin and reinforcing fiber in an injection cylinder and to inject a physical foaming agent, and to inject the mixture into a cavity of a molding die to mold a fiber reinforced resin molded product and In the equipment, the mixture (resin, reinforcing fiber, physical foaming agent) is maintained at a high pressure and injected into the mold cavity to prevent damage to the reinforcing fiber and ensure that the physical foaming agent is dispersed and kneaded into the resin. And appropriate foaming with a physical foaming agent to form a lightweight, fiber-reinforced resin molded article having the desired strength and rigidity, which is uniformly finely foamed.

  According to a first aspect of the present invention, there is provided a method for molding a fiber reinforced resin molded article, wherein the resin and the reinforced fiber are plasticized and kneaded in an injection cylinder having a screw having a check ring for preventing backflow at a front end side portion on the mold side. And injecting the mixture into a cavity of a molding die to form a fiber reinforced resin molded article, while the screw is retracted and rotated, the front side of the check ring in the injection cylinder A resin introduction step of introducing the resin plasticized and kneaded in the plasticization kneading portion on the back side of the check ring and the reinforcing fiber into the weighing resin reservoir portion, and during or after execution of the resin introduction step, in the weighing resin reservoir portion And a foaming agent injection / dispersion promoting step for promoting dispersion and kneading of the physical foaming agent into the resin.

  In the resin introduction process, while the screw having the check ring at the front end side is moved backward and rotated, the plasticizing kneading is carried out in the plasticizing kneading part on the rear side of the check ring in the metering resin reservoir part on the front side of the check ring in the injection cylinder. In order to inject a physical foaming agent into the metered resin reservoir during or after execution of the resin introduction process in the foaming agent injection dispersion promotion process, the check resin on the front end side of the screw is used. Back flow of the physical foaming agent, resin, and reinforcing fiber from the metered resin reservoir to the plasticization kneading unit is suppressed, and the internal pressure of the metered resin reservoir is maintained at a high level by the check ring.

  In other words, the mixture (resin, reinforcing fiber, physical foaming agent) is maintained at a high pressure and injected into the cavity of the molding die. Therefore, the conventional backflow prevention structure having a labyrinth structure becomes unnecessary, so that the damage of the reinforcing fiber ( Breakage) is prevented. In addition, in the foaming agent injection and dispersion promoting step, the physical foaming agent is injected into the metered resin reservoir, and the dispersion and kneading of the physical foaming agent into the resin is promoted, so that the dispersion and kneading of the physical foaming agent into the resin is ensured. The physical foaming agent is uniformly dispersed in the resin, and proper foaming with the physical foaming agent is performed. As a result, a lightweight, fiber-reinforced resin molded article having desired strength and rigidity that is foamed uniformly and finely is formed.

The following structure can be adopted as the structure of the dependent claim of the invention of claim 1.
In the foaming agent injection dispersion promoting step, physical foaming agent is sequentially or collectively injected into the metered resin reservoir from a plurality of different positions in the length direction of the injection cylinder from the front side to the rear side (Claim 2). In the agent injection dispersion promoting step, dispersion kneading of the physical foaming agent into the resin is promoted by the kneading head portion provided in the front part of the check ring of the screw.

  In the foaming agent injection dispersion promoting step, the physical foaming agent is sequentially moved from the plurality of positions different in the length direction of the injection cylinder into the metering resin reservoir portion, sequentially from the front side to the rear side corresponding to the position of the kneading head portion retreating. Injecting (Claim 4). In the foaming agent injection dispersion promoting step, a supercritical fluid is injected into the metered resin reservoir as a physical foaming agent.

  According to a sixth aspect of the present invention, there is provided a molding apparatus for a fiber reinforced resin molded article, comprising: a screw having a check ring for backflow prevention at a front end side portion on a molding die side; an injection cylinder incorporating the screw; It is equipped with a drive mechanism and a rotational drive mechanism that rotationally drives a screw, plasticizing and kneading resin and reinforcing fibers in an injection cylinder, injecting a physical foaming agent, and injecting the mixture into a mold mold cavity In an apparatus for molding a fiber reinforced resin molded article, a foaming agent injecting means for injecting a physical foaming agent into a metering resin reservoir on the front side of the check ring in the injection cylinder, and a physical foam injected by the foaming agent injecting means And a foaming agent dispersion promoting means for promoting dispersion and kneading of the agent into the resin.

  The screw is retracted and rotated by the advance / retreat drive mechanism and the rotation drive mechanism, and the resin and the reinforcing fiber are fed forward by the rotation of the screw, and plasticized and kneaded in the plasticizing and kneading part on the back side of the check ring in the injection cylinder. Resin and reinforcing fibers are introduced into the metering resin reservoir on the front side of the check ring, and the physical foaming agent is injected into the metering resin reservoir by the foaming agent injection means. The check ring provided on the front end side of the screw prevents the back flow of the physical foaming agent, resin, and reinforcing fiber from the metered resin reservoir to the plasticizing and kneading unit, so the internal pressure of the metered resin reservoir is controlled by the check ring. Is maintained at a high pressure.

  In other words, the mixture (resin, reinforcing fiber, physical foaming agent) is maintained at a high pressure and injected into the cavity of the molding die. Therefore, the conventional backflow prevention structure having a labyrinth structure becomes unnecessary, so that the damage of the reinforcing fiber ( Breakage) is prevented. In addition, the foaming agent dispersion promoting means promotes the dispersion and kneading of the physical foaming agent injected by the foaming agent injecting means into the resin, so that the physical foaming agent is surely dispersed and kneaded into the resin. Is uniformly dispersed in the resin, and proper foaming with a physical foaming agent is performed. As a result, a lightweight, fiber-reinforced resin molded article having desired strength and rigidity that is foamed uniformly and finely is formed.

The following structure can be adopted as the structure of the dependent claim of the invention of claim 6.
The foaming agent dispersion accelerating means has a kneading head portion provided in a front portion of the screw check ring. The foaming agent dispersion accelerating means allows the foaming agent injection means to inject the physical foaming agent into the metered resin reservoir part sequentially or collectively from the front side to the rear side from a plurality of different positions in the length direction of the injection cylinder. (Claim 8). The foaming agent injecting means includes a foaming agent injecting portion provided on the injection cylinder so as to be movable in the length direction and facing the metering resin reservoir, and the foaming agent injecting portion in the length direction of the injecting cylinder. And injection portion driving means for moving and driving.

  The foaming agent injecting means has a plurality of foaming agent injecting portions provided in the injection cylinder so as to be fixed at a plurality of different positions in the length direction and to face the metering resin reservoir. The foaming agent injecting means has injection switching means for switching so as to selectively inject a physical foaming agent from the plurality of foaming agent injecting portions. (Claim 11) The physical foaming agent is a fluid in a supercritical state. (Claim 12).

  According to the method for molding a fiber reinforced resin molded article according to claim 1, while the screw having a check ring for preventing backflow is moved backward and rotated at the front end side portion, the metering resin reservoir in the front side of the check ring in the injection cylinder Introducing a plastic foaming agent into the metered resin reservoir, during or after execution of the resin introduction step for introducing the plasticized and kneaded resin and the reinforcing fiber in the plasticization kneading portion on the rear side of the check ring In addition, a foaming agent injection / dispersion accelerating step that promotes dispersion and kneading of the physical foaming agent into the resin is included, so the mixture (resin, reinforcing fiber, physical foaming agent) is metered by checking the front end of the screw. The back flow from the resin reservoir to the plasticizing and kneading part is suppressed, and by the check ring, the mixture is maintained at a high pressure and injected into the cavity of the molding die. This can be achieved by eliminating the need for a backflow prevention structure having a road structure, preventing damage to the reinforcing fibers, ensuring that the physical foaming agent is dispersed and kneaded into the resin, and uniformly dispersing the physical foaming agent in the resin. Thus, it is possible to form a lightweight fiber-reinforced resin molded product having the desired strength and rigidity by appropriately foaming with a physical foaming agent and uniformly foaming finely.

  According to the method for molding a fiber-reinforced resin molded article according to claim 2, in the foaming agent injection dispersion promoting step, the physical foaming agent is introduced into the metering resin reservoir from a plurality of positions different in the length direction of the injection cylinder from the front side to the rear side. Since the physical foaming agent is uniformly injected in the length direction of the injection cylinder into the lightweight resin reservoir, the dispersion and kneading of the physical foaming agent into the resin can be surely promoted. it can.

  According to the method for molding a fiber-reinforced resin molded article according to claim 3, in the foaming agent injection dispersion promoting step, the physical foaming agent is dispersed and kneaded into the resin by the kneading head portion provided in the front part of the screw check ring. Therefore, more reliable dispersion and kneading of the physical foaming agent into the resin can be achieved with a simple configuration provided with a kneading head portion.

  According to the method for molding a fiber reinforced resin molded article according to claim 4, in the foaming agent injection dispersion promoting step, the physical foaming agent is retreated from a plurality of positions different in the length direction of the injection cylinder in the metering resin reservoir. Since the liquid is sequentially injected from the front side to the rear side corresponding to the position of the part, uniform dispersion kneading of the physical foaming agent into the resin can be promoted more reliably.

  According to the method for molding a fiber reinforced resin molded article of claim 5, in the foaming agent injection dispersion promoting step, a supercritical fluid is injected into the metered resin reservoir as a physical foaming agent. When the backflow prevention structure is not provided, it is difficult to prevent the backflow of the physical foaming agent. However, in the present invention, this can be improved and a finely foamed fiber reinforced resin molded product can be molded.

  According to the apparatus for molding a fiber-reinforced resin molded article according to claim 6, a screw having a check ring for backflow prevention at the front end side portion, an injection cylinder incorporating the screw, and a forward / backward drive mechanism for driving the screw forward / backward A rotation drive mechanism for rotating the screw, and a foaming agent injection means for injecting a physical foaming agent into a metering resin reservoir on the front side of the check ring in the injection cylinder, and a physical foam injected by the foaming agent injection means It is equipped with foaming agent dispersion accelerating means that promotes the dispersion and kneading of the agent into the resin, so plasticizing from the metered resin reservoir of the mixture (resin, reinforced fiber, physical foaming agent) by check ring on the front end side of the screw The back flow to the kneading part is suppressed, and the check ring keeps the mixture at a high pressure and injects it into the mold cavity, which has a conventional maze structure. This can be achieved by eliminating the need for a backflow prevention structure, preventing damage to the reinforcing fibers, and ensuring that the physical foaming agent is dispersed and kneaded into the resin, uniformly dispersing the physical foaming agent in the resin, Appropriate foaming with an agent can be performed to form a lightweight fiber-reinforced resin molded product having the desired strength and rigidity, which is uniformly finely foamed.

  According to the molding apparatus for the fiber-reinforced resin molded product of claim 7, since the foaming agent dispersion promoting means has the kneading head portion provided in the front part of the check ring of the screw, the kneading head portion is rotated. Thus, while more reliably kneading the resin and the reinforcing fiber, it is possible to reliably promote the dispersion kneading of the physical foaming agent into the resin, and a kneading head is provided for more reliable dispersion kneading of the physical foaming agent into the resin. This can be achieved with a simple configuration.

  According to the apparatus for molding a fiber-reinforced resin molded article according to claim 8, the foaming agent dispersion accelerating means causes the foaming agent injection means to place the physical foaming agent in the measuring resin reservoir from a plurality of positions different in the length direction of the injection cylinder. Since it is configured to be able to inject sequentially or collectively from the front side to the rear side, the physical foaming agent can be uniformly injected into the metering resin reservoir in the length direction of the cylinder for injection. The uniform dispersion kneading can be surely promoted.

  According to the apparatus for molding a fiber reinforced resin molded article according to claim 9, the foaming agent injecting means is provided on the injection cylinder so as to be movable in the length direction and to face the metering resin reservoir. Since the foaming agent injecting portion has an injecting portion driving means for moving and driving the foaming agent injecting portion in the length direction of the injection cylinder, the physical foaming agent is retracted from a plurality of positions different in the length direction of the injection cylinder in the metering resin reservoir portion. In accordance with the position of the kneading head portion to be carried out, it can be sequentially injected from the front side to the rear side, and uniform dispersion kneading of the physical foaming agent into the resin can be promoted more reliably.

  According to the apparatus for molding a fiber reinforced resin molded article according to claim 10, the foaming agent injection means is provided on the injection cylinder so as to be fixed at a plurality of different positions in the length direction and to face the measurement resin reservoir. Since it has a plurality of foaming agent injection portions, dispersion and kneading of the physical foaming agent into the resin can be surely promoted.

  According to the apparatus for molding a fiber reinforced resin molded article according to claim 11, the foaming agent injection means has injection switching means for switching so that the physical foaming agent is selectively injected from the plurality of foaming agent injection portions. The physical foaming agent can be sequentially injected into the resin reservoir from a plurality of positions different from each other in the length direction of the injection cylinder, from the front side to the rear side in accordance with the position of the kneading head that moves backward. Uniform dispersion kneading into the resin can be promoted more reliably.

  According to the apparatus for molding a fiber reinforced resin molded article according to claim 12, since the physical foaming agent is a fluid in a supercritical state, when a backflow prevention structure having a labyrinth structure is not provided in the prior art, Although it is difficult to prevent the backflow, the present invention improves this and makes it possible to mold a finely foamed fiber reinforced resin molded product.

  The molding method and molding apparatus for a fiber reinforced resin molded product of the present invention plasticize resin and reinforcing fiber in an injection cylinder having a screw having a check ring for preventing backflow in the front end side portion on the molding die side. In addition to kneading, a physical foaming agent is injected, and the mixture is injected into a cavity of a molding die to form a fiber reinforced resin molded product.

  The method for molding a fiber-reinforced resin molded product of the present invention is a method of plasticizing and kneading in a plasticizing and kneading part on the back side of a check ring in a metering resin reservoir part on the front side of the check ring in an injection cylinder while retreating and rotating a screw. Introducing a physical foaming agent into the metered resin reservoir and promoting dispersion and kneading of the physical foaming agent into the resin during or after execution of the resin introduction process for introducing the resin and the reinforcing fiber and the resin introduction process And a foaming agent injection dispersion promoting step.

  The fiber reinforced resin molded product molding apparatus according to the present invention includes a screw having a check ring for backflow prevention in a front end portion on the molding die side, an injection cylinder incorporating the screw, and a forward / backward drive for driving the screw forward / backward. A mechanism, a rotational drive mechanism for rotationally driving the screw, a foaming agent injecting means for injecting a physical foaming agent into the metering resin reservoir on the front side of the check ring in the injection cylinder, and physical foaming injected by the foaming agent injecting means And a foaming agent dispersion accelerating means for promoting dispersion and kneading of the agent into the resin.

First, the fiber reinforced resin molded product molding apparatus 1 will be described.
As shown in FIGS. 1 and 2, the molding apparatus 1 includes a molding die 2, a screw 3 having a check ring 20 for preventing a backflow at a front end side portion on the molding die 2 side, and an injection device incorporating the screw 3. Cylinder 4, advance / retreat drive mechanism 5 that drives the screw 3 back and forth, rotary drive mechanism 6 that drives the screw 3 to rotate, hopper 7 that feeds the raw material of the resin 15 and reinforcing fiber 16 into the injection cylinder 4, and inside the injection cylinder 4 The foaming agent injection mechanism 8 for injecting the physical foaming agent 17 into the foaming agent, the foaming agent supply mechanism 9 for supplying the physical foaming agent 17 to the foaming agent injection mechanism 8, and the resin 15 of the physical foaming agent 17 injected by the foaming agent injection mechanism 8. Is provided with a foaming agent dispersion accelerating mechanism 10 that promotes dispersion kneading.

  For example, the resin 15 is a synthetic resin such as polypropylene, the reinforcing fibers 16 are carbon fibers or glass fibers, the raw materials of the resin 15 and the reinforcing fibers 16 are resin pellets containing reinforcing fibers, and the physical foaming agent 17 is supercritical. This is a state of nitrogen or carbon dioxide fluid (Super Critical Fluid: SCF). Further, the molding apparatus 1 includes a control device 11, and the control device 11 controls the advance / retreat drive mechanism 5, the rotation drive mechanism 6, the foaming agent injection mechanism 8, and the like. The foaming agent dispersion promoting mechanism 10 includes a control device 11.

  Although illustration is omitted, the molding die 2 has a fixed die and a movable die, a die driving mechanism capable of clamping and opening the molding die 2, and the molding die 2 opened. An ejector mechanism for taking out a molded product (fiber reinforced resin molded product) is provided. The mold driving mechanism and the ejector mechanism are controlled by the control device 11.

  As shown in FIG. 2, the screw 3 has a check ring 20 for preventing backflow at the front end side portion, and has a second check ring 21 for preventing backflow at the rear side portion, and the check ring 20 of the screw 3. The kneading head 50 of the foaming agent dispersion accelerating mechanism 10 is provided at the front side. The screw 3 has a shaft portion 3a and screw portions 3b and 3c, and check rings 20 and 21 are movably attached to the shaft portion 3a by a predetermined stroke in the front-rear direction, and a kneading head 50 is fixedly attached. Screw portions 3b and 3c are integrally provided between the check rings 20 and 21 and on the rear side of the check ring 21 in the portion 3a.

  As shown in FIG. 2, the injection cylinder 4 has a front end portion connected to the molding die 2, a rear end portion fixed to the casing of the advance / retreat drive mechanism 5 and the rotation drive mechanism 6, and a rear end portion of the screw 3. Driving force is input from the advance / retreat drive mechanism 5 and the rotation drive mechanism 6. In the injection cylinder 4, the back side of the check ring 21 is configured as a raw material charging unit 25, the space between the check rings 20 and 21 is configured as a plasticizing and kneading unit 26, and the front side of the check ring 20 is configured as a weighing resin reservoir 27. It is configured. The hopper 7 is equipped on the rear end side portion of the injection cylinder 4 so that the raw material of the resin 15 and the reinforcing fiber 16 can be charged into the raw material charging portion 25.

  As shown in FIGS. 2 to 6, the foaming agent injection mechanism 8 injects the physical foaming agent 17 into the metered resin reservoir 27 of the injection cylinder 4, and the foaming agent dispersion promoting mechanism 10 is the foaming agent injection mechanism 8. Thus, the physical foaming agent 17 can be sequentially injected into the metered resin reservoir 27 from a plurality of positions different in the length direction of the injection cylinder 4 from the front side to the rear side.

  The foaming agent injection mechanism 8 includes a foaming agent injection unit 30 including an injection nozzle provided on the injection cylinder 4 so as to be movable in the front-rear direction and facing the measurement resin reservoir 27, and the foaming agent injection unit 30 in the front-rear direction. The injection unit drive mechanism 37 is driven to move. A movable sleeve 31 is provided on the injection cylinder 4 so as to be slidable back and forth in an outer fitting manner, and a foaming agent injection portion 30 is fixed to the movable sleeve 31. The injection cylinder 4 is formed with a slit 4a that is elongated in the front-rear direction in the moving region of the foaming agent injection portion 30, and an annular seal member 32 is provided between the injection cylinder 4 and the movable sleeve 31 on both front and rear sides of the slit 4a. It is sealed with.

  The physical foaming agent 17 is supplied from the foaming agent supply mechanism 9 to the foaming agent injection unit 30 through the supply passage 35, and an opening / closing valve 36 is provided in the supply passage 35. The injection part drive mechanism 37 has an actuator 38 composed of a fluid pressure cylinder and an electric motor, and an output part 38a thereof is connected to the movable sleeve 31. By this actuator 38, the foaming agent injection part 30 is moved forward and backward together with the movable sleeve 31. Is driven to move. About the blowing agent injection | pouring part 30 and the slit 4a, you may provide two or more in the position which differs in the circumferential direction in the front-back direction same position.

  As shown in FIG. 1, the foaming agent supply mechanism 9 includes a nitrogen or carbon dioxide cylinder 40 and a supercritical fluid (physical foaming agent 17) with the nitrogen or carbon dioxide sent from the cylinder 40 at a high temperature and high pressure. The physical foaming agent 17 is supplied from the SCF generation device 41 to the foaming agent injection unit 30 through the supply passage 35.

  As shown in FIGS. 1, 2, and 4 to 6, the foaming agent dispersion promoting mechanism 10 includes a foaming agent injection mechanism 8, a control device 11, and a kneading head 50, and the kneading head 50 has a top end at the top. A plurality of ridges 51 that are formed in a conical shape and extend radially around the top along the tapered portion are formed. The control device 11 controls the on-off valve 36 and the injection portion drive mechanism 37 (actuator 38) of the foaming agent injection mechanism 8 in synchronization with the backward drive and the rotation drive of the screw 3, and physically enters the metered resin reservoir 27. The foaming agent 17 is sequentially injected from the front side to the rear side corresponding to the position of the kneading head unit 50 that moves backward.

Next, a method for molding a fiber reinforced resin molded product will be described.
As shown in FIG. 7, in this molding method, the screw 3 is moved back and rotated from the injection completion position in FIG. 4 to the injection preparation position in FIG. The resin introduction step (P3) and the blowing agent injection dispersion promotion step (P4) are performed substantially simultaneously, and then the injection step (P5) is performed, and P1 to P5 are repeatedly performed to form a plurality of fiber reinforced resin moldings. Products are being molded.

  In the raw material charging step of P1, the raw materials of the resin 15 and the reinforcing fibers 16 are charged into the raw material charging unit 25 from the hopper 7, and the screw 3 is rotated so that the resin 15 and the reinforcing fibers 16 are plasticized and kneaded while being plasticized and kneaded. Introduced into the plasticizing and kneading unit 26 from the inside of the charging unit 25 through the passage reversely checked by the check ring 21, and in the plasticizing and kneading step P <b> 2, the screw 3 rotates, The resin 15 and the reinforcing fibers 16 are completely plasticized and kneaded while being transferred forward with respect to the screw 3.

  In the resin introduction process of P3, the screw 3 moves backward from the injection completion position of FIG. 4 to the injection preparation position of FIG. 6, so that the volume of the metering resin reservoir 27 increases, and the screw 3 rotates at that time. A passage through which the resin 15 and the reinforced fiber 16 plasticized and kneaded in the plasticizing and kneading unit 26 are sequentially returned from the plasticizing and kneading unit 26 by the check ring 20 in the weighing resin reservoir 27 whose volume increases. Introduced through. During the execution of this resin introduction step, the P4 blowing agent injection dispersion promotion step is executed.

  In the P4 blowing agent injection dispersion promoting step, the kneading head unit 50 moves backward integrally with the screw 3, but the kneading is performed so that the blowing agent injection unit 30 maintains a position where the injection direction faces the kneading head unit 50. The physical foaming agent 17 is injected into the metered resin reservoir 27 while retreating with the retreat of the head portion 50. In this way, the physical foaming agent 17 is sequentially and continuously injected from the plurality of positions different in the length direction of the injection cylinder 4 into the metering resin reservoir 27 from the front side to the rear side corresponding to the position of the kneading head unit 50 that moves backward. Is done. Further, since the kneading head portion 17 rotates integrally with the screw 3, the kneading head portion 17 disperses and kneads the physical foaming agent 17 into the resin 15 while more reliably kneading the resin 15 and the reinforcing fibers 16. Is done.

  In the injection process of P5, after a predetermined amount of the mixture (resin 15, reinforcing fiber 16 and physical foaming agent 17) is stored in the metered resin reservoir 27, the screw 3 moves forward so that the mixture is molded into the mold 2 After the resin 15 is cured to some extent, the molding die 2 is opened and finely foamed by releasing the pressure to form a fiber-reinforced resin molded product.

  According to the molding technique of the fiber-reinforced resin molded article described above, in the molding apparatus 1, the screw 3 having the check ring 20 for preventing the backflow in the front end side portion on the molding die 2 side, and the injection for incorporating the screw 3 A cylinder 4, a forward / backward drive mechanism 5 for driving the screw 3 back and forth, and a rotary drive mechanism 6 for driving the screw 3 to rotate are provided, and a physical foaming agent is placed in the metering resin reservoir 27 on the front side of the check ring 20 of the injection cylinder 4. A foaming agent injection mechanism 8 for injecting 17 and a foaming agent dispersion promoting mechanism 10 for promoting dispersion and kneading of the physical foaming agent 17 injected by the foaming agent injection mechanism 8 into the resin 15 are provided.

  Therefore, in the molding method of the fiber reinforced resin molded product, the plasticizing kneading on the rear side of the check ring 20 is performed in the metering resin reservoir 27 on the front side of the check ring 20 in the injection cylinder 4 while the screw 3 is moved backward and rotated. The resin introduction step of introducing the plasticized and kneaded resin 15 and the reinforcing fiber 16 in the portion 26, and the physical foaming agent 17 is injected into the metered resin reservoir portion 27 during the execution of this resin introduction step, and this physical A foaming agent injection / dispersion accelerating step for promoting the dispersion and kneading of the foaming agent 17 into the resin 15 can be realized.

  As a result, the check ring 20 on the front end side portion of the screw 3 suppresses the backflow of the mixture (resin 15, reinforcing fiber 16, physical foaming agent 17) from the metered resin reservoir portion 27 to the plasticizing kneading portion 26. 20, the mixture can be maintained at a high pressure and injected into the cavity of the molding die 2, which can be achieved without the need for a backflow prevention structure having a conventional labyrinth structure. 16 can be maintained at a desired length (for example, about 5 mm), and the physical foaming agent 17 is reliably dispersed and kneaded into the resin 15 to uniformly disperse the physical foaming agent 17 in the resin 15. It is possible to form a lightweight fiber-reinforced resin molded product having the desired strength and rigidity by foaming properly with the physical foaming agent 17 and foaming uniformly and finely (for example, about 10 μm). Na .

  The foaming agent dispersion accelerating mechanism 10 has the kneading head portion 50 provided in the front portion of the check ring 20 of the screw 3. Therefore, in the foaming agent injection and dispersion promoting step, the kneading head portion 50 is rotated to perform physical foaming. Kneading of the agent 17 into the resin 15 can be promoted, that is, the kneading of the resin 15 and the reinforcing fiber 16 can be more reliably performed, and the dispersion kneading of the physical foaming agent 17 into the resin 15 can be reliably promoted. More reliable dispersion and kneading of the physical foaming agent 17 into the resin 15 can be achieved with a simple configuration provided with the kneading head portion 50. In this case, the kneading head portion 50 is provided integrally with the screw 3, so Rotation is available.

  The foaming agent dispersion accelerating mechanism 10 allows the foaming agent injection mechanism 8 to sequentially inject the physical foaming agent 17 into the metered resin reservoir 27 from a plurality of positions in the length direction of the injection cylinder 4 from the front side to the rear side. For this purpose, the foaming agent injection mechanism 8 includes a foaming agent injection unit 30 that is provided on the injection cylinder 4 so as to be movable in the lengthwise direction and face the metering resin reservoir 27, and this foaming agent injection unit Since the injection unit drive mechanism 37 for moving and driving the portion 30 in the length direction of the injection cylinder 4 is provided, the physical foaming agent 17 is disposed in the metering resin reservoir 27 in the injection injection dispersion promoting step. From a plurality of positions different in the length direction, it is possible to sequentially inject from the front side to the rear side in correspondence with the position of the kneading head unit 50 that moves backward. Therefore, the physical foaming agent 17 is injected into the metering resin reservoir 27 in the injection cylinder. 4 head Can be uniformly injected into the direction can be more reliably promote uniform dispersion kneading to the resin 15 of the physical foaming agent 17.

  Since the physical foaming agent 17 is a supercritical fluid, the supercritical fluid can be injected into the metered resin reservoir 27 as the physical foaming agent 17 in the foaming agent injection dispersion promoting step. When no labyrinth structure is provided, it is difficult to prevent the backflow of the physical foaming agent 17, but in the present invention, this can be improved and a fiber-reinforced resin molded product that is very finely foamed can be reliably molded. .

  In the first embodiment, the following changes may be made. In the fiber reinforced resin molded product molding apparatus 1, the kneading head 50 is omitted, and in the fiber reinforced resin molded product molding method, a foaming agent injection dispersion promoting step is executed after the resin introduction step, and this foaming agent injection is performed. In the dispersion promoting step, the physical foaming agent 17 is placed in the metering resin reservoir 27 by moving the foaming agent injecting portion 30 in the front-rear direction with the screw 3 positioned at the injection preparation position in FIG. Injection is sequentially performed from a plurality of positions different in the length direction from the front side to the rear side (or from the rear side to the front side). Further, the check ring 21 in the rear portion of the screw 3 is omitted.

  As shown in FIG. 8, the molding apparatus 1A for the fiber-reinforced resin molded product of Example 2 is obtained by changing the foaming agent injection mechanism 8 and the foaming agent dispersion promoting mechanism 10 in the molding apparatus 1 of Example 1. In this molding apparatus 1A, the foaming agent injection mechanism 8A injects the physical foaming agent 17 into the metering resin reservoir 27 of the injection cylinder 4, and the foaming agent dispersion promoting mechanism 10A is controlled by the foaming agent injection mechanism 8A. The physical foaming agent 17 can be sequentially injected into the reservoir portion 27 from a plurality of positions different in the length direction of the injection cylinder 4 from the front side to the rear side.

  The foaming agent injection mechanism 8A includes a plurality of (for example, five) injection nozzles provided on the injection cylinder 4 so as to be fixed at a plurality of different positions in the length direction and to face the measuring resin reservoir 27. The foaming agent injecting unit 60 has an injection switching mechanism 68 for switching so that the physical foaming agent 17 is selectively injected from the plurality of foaming agent injecting units 60. The physical foaming agent 17 is supplied from the foaming agent supply mechanism 9 to the plurality of foaming agent injection portions 60 through the supply passage 65, and a plurality of on-off valves 66 are provided in the supply passage 65, and the injection switching mechanism 68 is opened and closed. It has a valve 66. About the foaming agent injection | pouring part 60, you may provide two or more in the position which differs in the circumferential direction in the front-back direction same position.

  The foaming agent dispersion accelerating mechanism 10A includes a foaming agent injection mechanism 8A, a control device 11, and a kneading head 50. The control device 11 is in the same position as the kneading head unit 50 in synchronization with the backward drive and the rotational drive of the screw 3. The position of the kneading head unit 50 for retreating the physical foaming agent 17 into the metered resin reservoir 27 by controlling the opening / closing of the plurality of on / off valves 66 so that only the on / off valve 66 corresponding to the foaming agent injection unit 60 is opened. Correspondingly, the injection is sequentially performed from the front side to the rear side.

  In the foaming agent injection dispersion promotion step of the molding method of the fiber reinforced resin molded product of Example 2, the physical foaming agent 17 is placed in the metering resin reservoir 27 in the injection cylinder 4 as in the foaming agent injection dispersion promotion step of Example 1. Are sequentially and sequentially injected from the front side to the rear side in correspondence with the position of the kneading head unit 50 that moves backward from a plurality of positions that differ in the length direction. In this fiber-reinforced resin molded product molding technique, the same actions and effects as in Example 1 can be obtained, and the same changes as those in Example 1 can be made.

  As shown in FIG. 9, the molding apparatus 1B for the fiber-reinforced resin molded product of Example 3 is obtained by changing the foaming agent injection mechanism 8 and the foaming agent dispersion promoting mechanism 10 in the molding apparatus 1 of Example 1. In this molding apparatus 1B, the foaming agent injection mechanism 8B injects the physical foaming agent 17 into the metering resin reservoir 27 of the injection cylinder 4, and the foaming agent dispersion promoting mechanism 10B is controlled by the foaming agent injection mechanism 8B. The physical foaming agent 17 can be injected into the reservoir portion 27 from a plurality of different positions in the length direction of the injection cylinder 4.

  The foaming agent injection mechanism 8 </ b> B has a cylindrical foaming agent injection member 70 provided integrally with the front portion of the injection cylinder 4, and a plurality of foaming agent injection portions 71 formed in the foaming agent injection member 70. In addition, the injection cylinder 4 has a foaming agent injecting portion 71 composed of a plurality of injection ports provided so as to be fixed to a plurality of different positions in the length direction and to face the measuring resin reservoir portion 27.

  Inside the foaming agent injecting member 70, a passage communicating with the plurality of foaming agent injecting portions 71 is formed, and the physical foaming agent 17 from the foaming agent supply mechanism 9 passes through the supply passage 75 in the passage of the foaming agent injecting member 70. An open / close valve 76 is provided in the supply passage 75. The foaming agent dispersion accelerating mechanism 10B includes a foaming agent injection mechanism 8B, a control device 11, and a kneading head 50. The control device 11 controls the open / close valve 76 to open after the screw 3 is driven backward, and a plurality of control devices 11 are operated. The physical foaming agent 17 is simultaneously injected from the foaming agent injection portion 71 into the metered resin reservoir portion 27.

  In the foaming agent injection dispersion promoting step of the molding method of the fiber reinforced resin molded product of Example 3, the foam injection injecting dispersion promoting step of P4 is executed after the execution of the P3 resin introducing step. The physical foaming agent 17 is collectively injected from a plurality of different positions in the length direction of the injection cylinder 4 into the metered resin reservoir 27 by the plurality of foaming agent injection portions 71. This fiber-reinforced resin molded product has the same functions and effects as those of the first embodiment. The kneading head 50 may be omitted.

  As shown in FIG. 10, the molding apparatus 1C for the fiber-reinforced resin molded product of Example 3 is different from the molding apparatus 1 of Example 1 in that the foaming agent injection mechanism 8, the foaming agent dispersion promoting mechanism 10, and the kneading head 50 are changed. Is. In this molding apparatus 1C, the foaming agent injection mechanism 8C injects the physical foaming agent 17 into the metering resin reservoir 27 of the injection cylinder 4, and the foaming agent dispersion promoting mechanism 10C is controlled by the foaming agent injection mechanism 8C. The physical foaming agent 17 can be sequentially injected into the reservoir portion 27 from a plurality of positions different in the length direction of the injection cylinder 4 from the front side to the rear side.

  The foaming agent injection mechanism 8C has a foaming agent injection part 80 composed of a plurality of injection ports formed on the kneading head 50C so as to face forward from the taper part. A passage 81 communicating with the plurality of blowing agent injection portions 80 is formed over the entire length. The kneading head 50C is obtained by forming a plurality of blowing agent injection portions 80 on the kneading head 50 of the first embodiment.

  The physical foaming agent 17 is supplied to the passage 81 of the screw 3 from the foaming agent supply mechanism 9 through the supply passage 85, and an opening / closing valve 86 is provided in the supply passage 85. The foaming agent dispersion accelerating mechanism 10C includes a foaming agent injection mechanism 8C, a control device 11, and a kneading head 50C. The control device 11 synchronizes with the backward drive and rotational drive of the screw 3 to open and close the foaming agent injection mechanism 8C. 86 is controlled to sequentially inject the physical foaming agent 17 into the metered resin reservoir 27 from the kneading head portion 50 </ b> C that moves backward.

  In the foaming agent injection dispersion promotion step of the molding method of the fiber reinforced resin molded article of Example 4, the P4 foam injection dispersion promotion step is executed during the execution of the P3 resin introduction step. The physical foaming agent 17 is sequentially injected into the metered resin reservoir 27 from a plurality of different positions in the length direction of the injection cylinder 4 by the plurality of foaming agent injection portions 80. In this fiber-reinforced resin molded product molding technique, the physical foaming agent 17 is injected from the kneading head 50C, so that the dispersion kneading of the physical foaming agent 17 into the resin 15 can be reliably promoted by the kneading head 50C.

  Example 5 discloses the kneading heads 50D to 50F applicable in the molding apparatuses 1 and 1A to 1C and the molding method of the fiber reinforced resin molded products of Examples 1 to 4. In addition, the basic shape of the kneading heads 50D to 50F is formed in a conical shape with the front end being the top, as in the first to fourth embodiments. As shown in FIG. 11, the kneading head 50 </ b> D has a plurality of (for example, three) convex portions 53 and a plurality of (for example, three) concave portions 54 in the taper portion alternately in the circumferential direction around the top portion. And is formed by dividing the above.

  As shown in FIG. 12, the kneading head 50E is formed with a plurality of protrusions 55 extending spirally from the top to the outer peripheral side along the taper portion. As shown in FIG. 13, the kneading head 50 </ b> F has a plurality of protrusions 56 extending spirally from the top to the outer peripheral side along the taper portion, and a plurality of kneading heads 50 </ b> F so as to face forward from the taper portion. A hole 57 is formed. Since the plurality of holes 57 can be used as a passage between the plasticized and kneaded resin 15 and the reinforcing fiber 16, the kneading of the resin 15 and the reinforcing fiber 16 can be promoted, and is applied to the molding apparatus 1C of the fourth embodiment. In some cases, it can be used as a blowing agent injection part. The kneading heads 50E and 50F are preferably rotated clockwise in front view.

  In addition, about the kneading heads 50 and 50C to 50F of Examples 1 to 5, as described above, the kneading heads 50 and 50C to 50F can be provided independently and rotatable in addition to being provided integrally with the screw 3. In this case, by providing an actuator such as an electric motor for rotationally driving the kneading head, the kneading head can be rotated independently of the screw 3, that is, the kneading head can be rotated faster than the rotational speed of the screw 3. Even if 3 is in a rotation stopped state, only the kneading head can be rotated. Therefore, further dispersion and kneading of the physical foaming agent 17 into the resin 15 can be expected.

  In addition, in the range which does not deviate from the meaning of the present invention, various modifications other than the above disclosed matters can be added and implemented, and the present invention can be applied to apparatuses and apparatuses for molding various fiber-reinforced resin molded products. It is possible to apply.

It is a side view of the shaping | molding apparatus of the fiber reinforced resin molded product of Example 1. FIG. It is a fragmentary sectional view of the principal part of the shaping | molding apparatus of a fiber reinforced resin molded product. It is a fragmentary sectional view of the principal part of the shaping | molding apparatus of a fiber reinforced resin molded product. It is operation | movement explanatory drawing of the shaping | molding apparatus of a fiber reinforced resin molded product. It is operation | movement explanatory drawing of the shaping | molding apparatus of a fiber reinforced resin molded product. It is operation | movement explanatory drawing of the shaping | molding apparatus of a fiber reinforced resin molded product. It is process drawing of the shaping | molding method of a fiber reinforced resin molded product. It is a fragmentary sectional view of the principal part of the molding apparatus of the fiber reinforced resin molded product of Example 2. It is a fragmentary sectional view of the principal part of the molding apparatus of the fiber reinforced resin molded product of Example 3. It is a fragmentary sectional view of the principal part of the molding apparatus of the fiber reinforced resin molded product of Example 4. 6 is a front view of a kneading head of Example 5. FIG. 10 is a front view of another kneading head of Example 5. FIG. 10 is a front view of still another kneading head of Example 5. FIG. It is a fragmentary sectional view of the principal part of the shaping | molding apparatus of the conventional fiber reinforced resin molded product.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,1A-1C Fiber-reinforced resin molded product molding apparatus 2 Molding die 3 Screw 4 Injection cylinder 5 Advance / retract drive mechanism 6 Rotation drive mechanism 8, 8A-8C Foaming agent injection mechanism 10, 10A-10C Foaming agent dispersion promoting mechanism DESCRIPTION OF SYMBOLS 15 Resin 16 Reinforcement fiber 17 Physical foaming agent 20 Check ring 26 Plasticization kneading part 27 Metering resin reservoir part 30, 60, 71, 80 Foaming agent injection part 37 Injection part drive mechanism 50, 50C-50F Kneading head part 68 Injection switching mechanism

Claims (12)

In a cylinder for injection with a screw having a check ring for backflow prevention in the front end side part on the molding die side, plastic and kneading resin and reinforcing fiber and injecting physical foaming agent, and the mixture is molded into the molding die In a method of injecting into a cavity of the above and molding a fiber reinforced resin molded product,
Resin introduction that introduces resin and reinforced fiber plasticized and kneaded in the plasticizing and kneading part on the rear side of the check ring into the weighing resin reservoir part on the front side of the check ring in the injection cylinder while the screw is moved backward and rotated Process,
During or after execution of the resin introduction step, a physical foaming agent is injected into the metered resin reservoir, and a foaming agent injection dispersion promoting step for promoting dispersion and kneading of the physical foaming agent into the resin,
A method for molding a fiber-reinforced resin molded product, comprising:   The foaming agent injection dispersion promoting step is characterized in that physical foaming agents are sequentially or collectively injected into the metered resin reservoir from a plurality of different positions in the length direction of the injection cylinder from the front side to the rear side. 2. A method for molding a fiber-reinforced resin molded article according to 1.   The said foaming agent injection | distribution acceleration | stimulation process WHEREIN: The dispersion | distribution kneading | mixing to the resin of a physical foaming agent is accelerated | stimulated by the kneading head part provided in the front side part rather than the check ring of the said screw. Molding method of fiber reinforced resin molded product.   In the foaming agent injection dispersion promoting step, the physical foaming agent is sequentially moved from the plurality of positions different in the length direction of the injection cylinder into the metering resin reservoir portion, sequentially from the front side to the rear side corresponding to the position of the kneading head portion retreating. The method for molding a fiber-reinforced resin molded product according to claim 3, wherein injection is performed.   In the said foaming agent injection | spreading acceleration | stimulation process, the fluid of a supercritical state is inject | poured in the said measurement resin reservoir as a physical foaming agent, The shaping | molding of the fiber reinforced resin molded product in any one of Claims 1-4 characterized by the above-mentioned. Method. A screw having a check ring for backflow prevention at the front end portion on the molding die side, an injection cylinder incorporating the screw, an advance / retreat drive mechanism for driving the screw forward and backward, and a rotation drive mechanism for rotating the screw In an apparatus for molding a fiber reinforced resin molded product by plasticizing and kneading resin and reinforcing fiber in an injection cylinder and injecting a physical foaming agent, and injecting the mixture into a cavity of a molding die,
A foaming agent injection means for injecting a physical foaming agent into the metering resin reservoir on the front side of the check ring in the injection cylinder;
Foaming agent dispersion promoting means for promoting dispersion and kneading of the physical foaming agent injected by the blowing agent injection means into the resin;
An apparatus for molding a fiber-reinforced resin molded product, comprising:   The said foaming agent dispersion | distribution acceleration | stimulation means has a kneading head part provided in the front side part rather than the check ring of the said screw, The shaping | molding apparatus of the fiber reinforced resin molded product of Claim 6 characterized by the above-mentioned.   The foaming agent dispersion accelerating means allows the foaming agent injection means to inject the physical foaming agent into the metered resin reservoir part sequentially or collectively from the front side to the rear side from a plurality of different positions in the length direction of the injection cylinder. The apparatus for molding a fiber-reinforced resin molded article according to claim 6 or 7, wherein the apparatus is configured.   The foaming agent injecting means includes a foaming agent injecting portion provided on the injection cylinder so as to be movable in the length direction and facing the metering resin reservoir, and the foaming agent injecting portion in the length direction of the injecting cylinder. 9. The apparatus for molding a fiber-reinforced resin molded product according to claim 8, further comprising injection unit driving means for moving and driving.   The foaming agent injecting means has a plurality of foaming agent injecting portions provided on the injection cylinder so as to be fixed at a plurality of different positions in the length direction and to face the measuring resin reservoir portion. Item 9. A molding apparatus for a fiber-reinforced resin molded article according to Item 8.   The fiber-reinforced resin molded article according to claim 10, wherein the foaming agent injection means includes injection switching means for switching so that a physical foaming agent is selectively injected from the plurality of foaming agent injection portions. Molding equipment.   The apparatus for molding a fiber-reinforced resin molded article according to any one of claims 6 to 11, wherein the physical foaming agent is a fluid in a supercritical state.

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