JP6893828B2 - Injection equipment of injection molding machine for foam molding - Google Patents

Description

The present invention relates to an injection device of an injection molding machine for foam molding, and more particularly to a mechanism for supplying a physical foaming agent to a heating cylinder head.

The applicant of the present application has previously provided at least a part of a porous material in the heating cylinder head as an injection device of an injection molding machine for foam molding using _{CO 2} gas, N _{2 gas, etc. in a supercritical state as a foaming agent.} A sleeve having a center hole forming a part of the resin passage is built in the formed portion formed of the porous material, and foamed between the outer peripheral surface of the sleeve and the inner peripheral surface of the heating cylinder head. We have proposed a product that forms an introduction space for the agent (see, for example, Patent Document 1). In the present specification, the supercritical fluid used as a foaming agent is referred to as a "physical foaming agent".

In the injection device described in Patent Document 1, a physical foaming agent supply nozzle is attached to the heating cylinder head, and the physical foaming agent supplied from the nozzle is placed between the outer peripheral surface of the sleeve and the inner peripheral surface of the heating cylinder head. When injected into the formed physical foaming agent introduction space (hereinafter, abbreviated as "introduction space"), the physical foaming agent injected into the introduction space is fine in the portion formed by the porous material of the sleeve. It is supplied into the center hole and the resin passage through the various holes. Therefore, according to the injection device described in Patent Document 1, physical foaming is performed as compared with the case where the physical foaming agent is directly supplied into the resin passage of the heating cylinder head from the introduction hole of the physical foaming agent provided in the heating cylinder head. Since the contact area between the agent and the plasticized resin can be expanded, the diffusion rate of the physical foaming agent into the plasticized resin can be increased, the shot cycle can be shortened, and the molded product can be homogenized.

Japanese Unexamined Patent Publication No. 2012-232558

However, injection molding machines for foam molding are required to further shorten the shot cycle. In order to shorten the shot cycle, it is necessary to further increase the diffusion rate of the physical foaming agent into the plasticizer.

The present invention has been made to solve such a problem of the prior art, and an object of the present invention is to rapidly diffuse a physical foaming agent into a plasticized resin stored in a heating cylinder head. An object of the present invention is to provide an injection device for an injection molding machine for foam molding, which has high productivity of foam molded products.

In order to solve the above problems, the present invention comprises a screw provided with a check ring mechanism for preventing backflow on the tip side, a heating cylinder in which the screw is rotatably and forward-movingly housed, and a tip portion of the heating cylinder. A heating cylinder head provided in the above, an injection nozzle connected to the tip of the heating cylinder head, and a foaming agent supply nozzle for supplying a physical foaming agent attached to the heating cylinder head, at least a part of which is porous. A sleeve formed of a material and having a center hole having a resin passage in the center, and a plasticized resin stored in a measuring resin reservoir from the tip of the screw to the tip of the injection nozzle. In the injection device of an injection molding machine for foam molding, a mixture of the physical foaming agent supplied from the foaming agent supply nozzle and the physical foaming agent is injected and filled into the cavity of the mold to form a required foam molded product. The sleeve is housed in the heating cylinder head, and at least a part of the physical foaming agent is formed of a porous material in the center hole formed in the sleeve and is supplied to the center from the foaming agent supply nozzle. A resin that accommodates a needle provided with an introduction space , the needle is held by a torpedo housed in the heating cylinder head and arranged at the center of the center hole, and the torpedo communicates with the center hole. It is characterized by having a flow hole and an introduction hole for a physical foaming agent that communicates with the introduction space.

According to the above configuration, the heating cylinder head accommodates a sleeve having at least a part formed of a porous material and having a center hole having a resin passage in the center, so that physical foaming jetted from a foaming agent supply nozzle is accommodated. The agent spreads in the surface direction of the sleeve through the fine pores of the sleeve, and is uniformly ejected from the entire circumference direction of the center hole into the plasticizer stored in the measuring resin reservoir. Further, according to the above configuration, since at least a part of the needle is formed of a porous material and a needle having a space for introducing a physical foaming agent in the center is housed in the center hole, the physical injection from the foaming agent supply nozzle is performed. The foaming agent first enters the introduction space and spreads in the length direction of the needle, and further, the physical foaming agent supplied into the introduction space spreads in the surface direction of the needle through the fine pores of the needle. , It is uniformly ejected from the entire circumference direction of the center hole to the plasticized resin stored in the measuring resin reservoir. As described above, according to the above configuration, since the plasticized resin stored in the measuring resin reservoir is uniformly ejected from both the outer peripheral direction and the inner peripheral direction of the center hole, the measuring is performed only from the outer peripheral direction of the center hole. The contact area between the plasticizer and the physical foaming agent can be increased as compared with the case where the physical foaming agent is supplied to the plasticizer stored in the resin reservoir. Therefore, the diffusion of the physical foaming agent into the plasticizer can be made rapid and uniform, and the productivity of the foam molded product having the required quality can be increased.

According to the above configuration, since the needle is held by using the torpedo housed in the resin passage, the needle can be stably held in the center hole. Further, according to the above configuration, since the needle is arranged at the center of the center hole formed in the sleeve, the diffusion of the physical foaming agent into the plasticizer can be made more uniform.

Further, the present invention is characterized in that, in the injection molding machine for foam molding having the above configuration, the needle is formed as a separate body independent of the torpedo and is screwed to the torpedo.

According to the above configuration, since the needle made of the porous material and the torpedo made of the bulk material are formed as independent bodies, for example, a portion corresponding to the needle and a portion corresponding to the torpedo are integrally formed by laser processing or the like. Compared with the case, the manufacturing of each part can be facilitated and the total manufacturing cost can be reduced. Further, when the needle or the torpedo is damaged, only necessary members need to be replaced, which is excellent in economy. Further, according to the above configuration, since the needle is screwed to the torpedo, the assembly work of the needle and the torpedo can be easily performed.

Further, the present invention is characterized in that, in the injection molding machine for foam molding having the above configuration, an introduction space for a physical foaming agent supplied from the foaming agent supply nozzle is formed between the heating cylinder head and the sleeve. To do.

According to the above configuration, since the introduction space of the physical foaming agent is formed between the heating cylinder head and the sleeve, the physical foaming agent supplied from the foaming agent supply nozzle is expanded in the length direction of the heating cylinder head, and then It is uniformly ejected from the entire circumference direction of the center hole to the plasticized resin stored in the measuring resin reservoir through the fine pores of the sleeve. Therefore, the diffusion of the physical foaming agent into the plasticized resin can be made more rapid and uniform than in the case where the introduction space of the physical foaming agent is not formed between the heating cylinder head and the sleeve.

Further, according to the present invention, in the injection molding machine for foam molding having the above configuration, the foaming agent supply nozzle supplies the physical foaming agent into the introduction space formed between the heating cylinder head and the sleeve. It is characterized in that it is composed of a combination of the foaming agent supply nozzle of No. 1 and a second foaming agent supply nozzle for supplying a physical foaming agent into the introduction space provided in the center of the needle.

According to the above configuration, since the injection molding machine for foam molding is provided with two foaming agent supply nozzles, a predetermined amount of physical foaming agent can be plasticized in a short time as compared with the case where only one foaming agent supply nozzle is provided. It can be introduced into the resin.

In the present invention, since the physical foaming agent can be supplied into the plasticizer stored in the center hole from both the outside and the inside of the center hole forming a part of the resin passage, the physical foaming agent to the plasticizer can be supplied. The diffusion rate of the physical foaming agent can be increased, and the diffusion of the physical foaming agent into the plasticizer can be made uniform. Therefore, according to the present invention, an effervescent molded product having a required quality can be produced with high efficiency.

It is a block diagram of the injection molding machine for foam molding including the injection apparatus which concerns on embodiment. It is an enlarged sectional view of the main part of the injection apparatus which concerns on embodiment. It is sectional drawing which shows the 1st example of the sleeve which concerns on embodiment. It is sectional drawing which shows the 2nd example of the sleeve which concerns on embodiment. It is sectional drawing of the screwed state of a needle and a torpedo which concerns on embodiment. FIG. 5 is a sectional view taken along the line AA of FIG.

Hereinafter, embodiments of the injection device according to the present invention will be described with reference to the drawings. It should be noted that the embodiments described below show an example when embodying the present invention, and do not limit the scope of the present invention to the scope described in the embodiments. Therefore, the present invention can be implemented with various modifications to the embodiments.

First, with reference to FIG. 1, the entire injection molding machine 1 for foam molding provided with the injection device according to the embodiment will be described. As shown in FIG. 1, the injection molding machine 1 for foam molding of this example supplies a physical foaming agent to a mold opening / closing / mold clamping unit 3 and an injection device 4 arranged oppositely on a frame 2 and an injection device 4. The physical foaming agent supply device 5 is provided.

The mold opening / closing / mold clamping unit 3 is arranged between the tail stock 11 and the fixed die plate 12 arranged opposite to each other on the frame 2 at a predetermined interval, and the tail stock 11 and the fixed die plate 12, and the frame. 2 A movable die plate 13 movably mounted on the top 2 and a toggle link mechanism 14 having both ends connected to the tailstock 11 and the movable die plate 13 are provided. The movable die plate 13 moves on the frame 2 guided by a tie bar 15 whose both ends are connected to the tailstock 11 and the fixed die plate 12. A fixed-side mold 16 is mounted on the fixed die plate 12, and a movable-side mold 17 is mounted on the movable die plate 13.

An electric servomotor 18 for opening / closing and clamping the mold is mounted on the tailstock 11, and a nut body 19a of the ball screw mechanism 19 is rotatably attached to the tailstock 11. The screw shaft 19b of the ball screw mechanism 19 is screwed into the nut body 19a, and the tip of the screw shaft 19b is connected to the cross head 14a of the toggle link mechanism 14. The spindle of the electric servomotor 18 for opening / closing and clamping the mold is connected to the nut body 19a of the ball screw mechanism 19 via an appropriate rotation transmission mechanism such as a timing belt. Therefore, when the electric servomotor 18 for opening / closing / clamping the mold is rotated forward or reverse, the toggle link mechanism 14 is expanded or contracted via the ball screw mechanism 19 and the crosshead 14a, and the fixed side mold 16 and the movable side mold 16 and the movable side mold are expanded or contracted. The opening and closing of 17 and the mold clamping are performed.

A mold thickness adjusting motor 20 is mounted on the tailstock 11, and a mold thickness adjusting nut 21 screwed into a screw portion (not shown) formed at the end of the tie bar 15 can rotate. Be prepared. The spindle of the mold thickness adjusting motor 20 is connected to the gear portion 21a of the mold thickness adjusting nut 21 via an appropriate rotation transmission mechanism. Therefore, when the mold thickness adjusting motor 20 is rotated forward or reverse while the tailstock 11 is released from being fixed to the frame 2, the mold thickness adjusting nut 21 moves in the length direction of the tie bar 15 and the tailstock to the frame 2 is released. The set position of 11 is adjusted. Thereby, the mold thickness can be adjusted after the fixed side mold 16 and / or the movable side mold 17 is replaced.

The injection device 4 includes a heating cylinder 31, a heating cylinder head 32 attached to the tip of the heating cylinder 31, and an injection nozzle 33 attached to the tip of the heating cylinder head 32. Inside the heating cylinder 31, the screw 34 is housed so as to be rotatable and forward / backward. A band heater 35 is wound around the outer circumference of the heating cylinder 31. The heating cylinder 31 is attached to the hopper block 36, and the hopper block 36 is provided with a screw drive unit 37 which is a drive source of the screw 34 and a hopper 38 for storing the raw material resin. The heating cylinder 31 receives the supply of the raw material resin stored in the hopper 38 inside the hopper block 36. The hopper block 36 is driven forward and backward to the nozzle touch position or the nozzle back position by the nozzle touch / back motor 39 provided on the frame 2.

The heating cylinder 31 cooperates with the screw 34 to draw in, plasticize, measure, and inject the raw material resin stored in the hopper 38. That is, when the screw 34 is rotationally driven by the screw drive unit 37, the raw material resin stored in the hopper 38 is sequentially drawn into the heating cylinder 31 by the screw feeding action of the screw 34. The raw material resin drawn into the heating cylinder 31 is plasticized by the frictional heat and shear insulation generated by the rotation of the screw 34 and the electric heat given by the band heater 35. The plasticized resin is sequentially transferred to the tip end side of the heating cylinder 31 by the screw feeding action of the screw 34, and the amount of resin required for one injection is measured. Then, after a predetermined amount of plasticizer is stored in the tip of the heating cylinder 31, the screw 34 is driven forward, and the predetermined amount of plasticizer stored in the tip of the heating cylinder 31 is transferred to the fixed side mold. It is injected into the cavity formed between the 16 and the movable mold 17.

As shown in an enlarged manner in FIG. 2, the screw 34 is composed of a screw main body 41 having a screw groove 41a formed on an outer peripheral surface thereof, and a screw-shaped screw head 42 attached to the tip of the screw main body 41. A check ring mechanism 43 for preventing backflow is arranged between the screw body 41 and the screw head 42. The check ring mechanism 43 includes a check sheet 44 fixed to the screw main body 41 and a check ring 45 rotatably and forwardly fitted to the screw main body 41.

In the process of plasticizing the raw material resin, the check ring 45 moves in a direction away from the check sheet 44 due to the pressure of the plasticizing resin transferred from the screw body 41 side to the screw head 42 side, and the check ring mechanism 43 automatically operates. It is switched to the conductive state. Therefore, the plasticized resin transferred from the screw body 41 side is transferred to the tip end side of the screw head 42 through a gap (not shown) provided between the screw body 41 and the check ring 45. When a predetermined amount of plasticized resin is stored on the tip side of the screw head 42, the check ring 45 is brought into close contact with the check sheet 44 by the pressure, and the check ring mechanism 43 is automatically switched to the non-conducting state. Therefore, the backflow of the plasticized resin during weighing and injection of the plasticized resin is prevented.

Further, since the screw 34 according to the embodiment includes the check ring mechanism 43, it is possible to prevent the backflow of the physical foaming agent supplied to the heating cylinder head 32. Hereinafter, the mechanism for supplying the physical foaming agent to the heating cylinder head 32 will be described.

As shown in FIG. 2, the heating cylinder head 32 is formed in a cylindrical shape, and first and second nozzle mounting holes 52 and 53 are formed on the outer peripheral surface. The first and second nozzle mounting holes 52 and 53 also function as introduction holes for the physical foaming agent. In the heating cylinder head 32, the physical foaming agent supplied from the physical foaming agent supply device 5 through the first nozzle mounting hole 52 is put into the measuring resin reservoir 54 from the check ring 45 to the tip of the injection nozzle 33. The sleeve 61 dispersed and supplied to the stored plastic foam and the physical foaming agent supplied from the physical foaming agent supply device 5 through the nozzle mounting hole 53 are transferred to the plastic foam stored in the measuring resin reservoir 54. A needle 62 that is distributed and supplied and a torpedo 63 that holds the needle 62 are housed.

As shown in FIGS. 3 and 4, the sleeve 61 is composed of a cylindrical portion 61a and flange portions 61b and 61c formed at both ends thereof, and a center hole penetrating from the end surface of the flange portion 61b to the end surface of the flange portion 61c. 61d has been opened. In the examples of FIGS. 3 and 4, the outer diameter of the flange portion 61b is formed to be larger than the outer diameter of the flange portion 61c, but the gist of the present invention is not limited to this. That is, it is sufficient that the outer diameters of the flange portions 61b and 61c are formed in the heating cylinder head 32 so as to be able to stably hold the sleeve 61. The sleeve 61 is housed in the heating cylinder head 32 so that the center of the cylindrical portion 61a in the length direction is substantially aligned with the central axis of the first nozzle mounting hole 52 provided in the heating cylinder head 32.

As described above, since the sleeve 61 of this example is composed of a small-diameter cylindrical portion 61a and large-diameter flange portions 61b and 61c formed at both ends thereof, the sleeve 61 is inside the heating cylinder head 32. When installed at a predetermined position, a ring-shaped physical foaming agent introduction space 61f communicating with the first nozzle mounting hole 52 is formed. The physical foaming agent introduction space 61f has a function of spreading the physical foaming agent supplied from the first nozzle mounting hole 52 in the plane direction of the cylindrical portion 61a.

In the sleeve 61 shown in FIG. 3, the entire cylindrical portion 61a is formed of a porous sintered metal material having a porosity of 5% to 60%, and the flange portions 61b and 61c are formed of a bulk material. When the entire cylindrical portion 61a is formed of the porous sintered metal material in this way, the physical foaming agent can be supplied into the measuring resin reservoir 54 through the entire cylindrical portion 61a, so that the physical foaming agent is stored in the measuring resin reservoir 54. The diffusion rate of the physical foaming agent into the plasticized resin can be most efficiently performed, and the productivity of the foamed molded product can be maximized. Further, since the porosity of the cylindrical portion is set to 5% to 60%, the physical foaming agent can be quickly and sufficiently ejected into the plasticizer, and the mechanical strength of the sleeve 61 is maintained appropriately. be able to.

On the other hand, the sleeve 61 shown in FIG. 4 has a reinforcing portion 61e formed of a bulk material in the length direction and the circumferential direction of the cylindrical portion 61a, and only the portion surrounded by the reinforcing portion 61e is formed. , It is made of a porous sintered metal material having a porosity of 5% to 60%. In the sleeve 61 of this example, since the reinforcing portion 61e made of a bulk material is formed on the cylindrical portion 61a, the mechanical strength of the sleeve 61 is high and the durability is excellent. In addition, in FIG. 3 and FIG. 4, the portion formed of the porous sintered metal material is represented by a dot pattern.

The sleeve 61 shown in FIGS. 3 and 4 can be manufactured by laser machining. That is, when a metal powder (including an alloy powder) is irradiated with a high-level laser, the metal powder is completely melted by the heat and becomes a bulk material after solidification, and when a low-level laser is irradiated, the metal powder is generated by the heat. Since only a part of the metal powder is melted and solidified to become a porous sintered metal, a metal powder layer having a ring-shaped planar shape and a predetermined thickness is formed on the workbench, and then in the circumferential direction of the metal powder layer. By irradiating an appropriate level of laser along the metal powder layer, the entire circumferential direction of the metal powder layer can be made into a porous sintered metal or a bulk material. Further, by appropriately switching the laser power with respect to the circumferential direction of the metal powder layer, the portion made of the porous sintered metal and the portion made of the bulk material can be alternately formed in the circumferential direction. Therefore, the sleeve 61 having a required shape can be produced by repeating laminating the metal powder layers in the thickness direction and irradiating each metal powder layer with a laser, and finally performing a required finishing process. The porosity of the porous sintered metal can be adjusted by changing the laser power.

As shown in an enlarged view in FIG. 5, the needle 62 is formed in a bottomed tubular shape having a male screw 62a at one end, and at least the portion excluding the male screw 62a is porous with a porosity of 5% to 60%. It is made of sintered metal material. At the center of the needle 62, an introduction space 62b of a physical foaming agent that penetrates the end of the male screw 62a is formed. The introduction space 62b has a function of spreading the physical foaming agent supplied from the physical foaming agent supply device 5 through the second nozzle mounting hole 53 in the length direction of the needle 62. The needle 62 can also be manufactured in the same manner as the sleeve 61.

As shown in FIGS. 5 and 6, the torpedo 63 is formed in a cylindrical shape having a diameter that can be inserted into the heating cylinder head 32, and a male screw 62a of the needle 62 is screwed into the central portion of one end. A female screw 63a for the purpose is formed. Further, when the torpedo 63 is housed in the torpedo 63 at a predetermined position in the heating cylinder head 32, the central portion of the female screw 63a is formed from a position facing the second nozzle mounting hole 53 provided in the heating cylinder head 32. Along with opening an introduction hole 63b for a physical foaming agent extending to, a resin flow hole 63c communicating with a center hole 61d opened in the sleeve 61 is opened. The needle 62 is integrated with the torpedo 63 by screwing the male screw 62a into the female screw 63a. As shown in FIG. 2, the torpedo 63 in which the needle 62 is screwed is housed in the heating cylinder head 32 by arranging the needle 62 in the center hole 61d of the sleeve 61.

The shape and size of the resin flow hole 63c are formed so that the pressure loss of the plasticized resin flowing in the resin flow hole 63c can be minimized. Therefore, in the torpedo 63 of this example, as shown in FIG. 6, four resin flow holes 63c formed in a fan shape are arranged equally on the circumference centered on the axis O of the torpedo 63. There is. The shape of the resin flow holes 63c is not limited to a fan shape, and the number may be appropriately changed even if it is a round shape.

As shown in FIG. 1, the physical foaming agent supply device 5 uses a _{gas cylinder 71 for storing raw material gases such as CO 2} gas and N ₂ gas, and a raw material gas supplied from the gas bomb 71 at a high temperature and high pressure to achieve supercritical physics. From the supercritical fluid generator 72 as a foaming agent, the first foaming agent supply nozzle 73 that injects the physical foaming agent supplied from the supercritical fluid generator 72 into the introduction space 61f, and the supercritical fluid generator 72. A pipeline connecting the second foaming agent supply nozzle 74 that injects the supplied physical foaming agent into the introduction space 62b, the supercritical fluid generator 72, and the first and second foaming agent supply nozzles 73 and 74. It is composed of an on-off valve 76 provided in the 75.

The first foaming agent supply nozzle 73 is attached to the first nozzle mounting hole 52 provided in the heating cylinder head 32, and the second foaming agent supply nozzle 74 is a second foaming agent supply nozzle 74 opened in the heating cylinder head 32. It is mounted in the nozzle mounting hole 53. To attach the first foaming agent supply nozzle 73 to the first nozzle mounting hole 52, for example, a female screw is engraved in the first nozzle mounting hole 52 and a male screw is formed on the outer periphery of the tip of the first foaming agent supply nozzle 73. It can be done by engraving and screwing a male screw into a female screw. The second foaming agent supply nozzle 74 can be attached to the second nozzle attachment hole 53 in the same manner. The physical foaming agent is supplied into the heating cylinder head 32 by opening the on-off valve 76 during or after the weighing process of each shot executed by the injection molding machine 1 for foam molding.

The physical foaming agent injected from the first foaming agent supply nozzle 73 into the introduction space 61f is formed from a portion of the cylindrical portion 61a formed in the sleeve 61 made of the porous sintered metal material, and the fine particles of the portion. It reaches the center hole 61d of the sleeve 61 through the various holes. Further, the physical foaming agent injected from the second foaming agent supply nozzle 74 is supplied into the introduction space 62b of the needle 62 through the introduction hole 63b formed in the torpedo 63, and is a fine hole in the needle 62. Through, it reaches the center hole 61d of the sleeve 61. As a result, the physical foaming agent comes into contact with the plasticizer stored in the measuring resin reservoir 54, and the physical foaming agent is diffused into the plasticizer.

When the screw 34 is driven forward after the weighing step, a plasticizer containing a physical foaming agent is injected into a cavity formed between the fixed-side mold 16 and the movable-side mold 17, and a foam-molded product having a predetermined shape is injected. Is produced.

Hereinafter, the effect of the injection device 4 configured as described above will be described.

The injection device 4 according to the embodiment has a configuration in which a physical foaming agent is supplied to the plasticizer stored in the measuring resin reservoir 54 from both the outer peripheral side and the inner peripheral side of the center hole 61d formed in the sleeve 61. have.
Therefore, the injection device 4 according to the embodiment is plasticized as compared with a conventional injection molding machine for foam molding in which a physical foaming agent is supplied into the plasticizing resin only from the outer peripheral side of the center hole 61d formed in the sleeve 61. The diffusion rate of the physical foaming agent into the resin can be increased, and the productivity of the foam molded product can be increased.

Further, the injection device 4 according to the embodiment discloses a configuration in which the needle 62 is held by the torpedo 63 housed in the heating cylinder head 32 and arranged in the center of the center hole 61d formed in the sleeve 61. There is.
Therefore, the injection device 4 according to the embodiment can stably hold the needle 62 in the central portion of the center hole 61d, so that the physical foaming agent can be more diffused into the plasticizer stored in the measuring resin reservoir 54. It can be uniform.

Further, the injection device 4 according to the embodiment has a configuration in which the needle 62 and the torpedo 63 are formed as independent bodies, and these members are integrally assembled by screwing.
Therefore, the injection device 4 according to the embodiment can facilitate the production of the needle 62 and the torpedo 63, and when either the needle 62 or the torpedo 63 is damaged, only necessary members need to be replaced, which is economical. Excellent for. Further, in the injection device 4 according to the embodiment, since the needle 62 and the torpedo 63 are integrated by screwing, the assembly work of the needle 62 and the torpedo 63 can be easily performed.

Further, the injection device 4 according to the embodiment has a configuration in which a physical foaming agent introduction space 61f is formed between the heating cylinder head 32 and the sleeve 61.
Therefore, the injection device 4 according to the embodiment spreads the physical foaming agent supplied from the first foaming agent supply nozzle 73 in the length direction of the heating cylinder head 32, and then stores the physical foaming agent in the measuring resin reservoir 54. Since it can be supplied into the plasticizer, the diffusion of the physical foaming agent into the plasticizer can be made more rapid and uniform.

Further, in the injection device 4 according to the embodiment, the first foaming agent supply nozzle 73 for supplying the physical foaming agent into the introduction space 61f formed between the heating cylinder head 32 and the sleeve 61, and the center of the needle 62. It has a configuration including a second foaming agent supply nozzle 74 for supplying a physical foaming agent in the introduction space 62b provided in the portion.
Therefore, the injection device 4 according to the embodiment can introduce a predetermined amount of the physical foaming agent into the plasticizer in a short time as compared with the case where only one foaming agent supply nozzle is provided.

The scope of the present invention is not limited to the configuration of the above-described embodiment. For example, in the above-described embodiment, the needle 62 and the torpedo 63 are integrated by screwing, but instead of such a configuration, the needle 62 and the torpedo 63 can be integrated by other means such as press fitting. .. Further, in the above-described embodiment, the needle 62 and the torpedo 63 are configured as independent bodies, but instead of such a configuration, the needle 62 and the torpedo 63 can be integrally formed. Even with such a configuration, the diffusion rate of the physical foaming agent into the plasticizer can be increased.

The injection nozzle 33 is attached to the tip of the heating cylinder head 32 by, for example, screwing, and one end of the injection nozzle 33 is abutted against the end of the torpedo 63. As a result, the sleeve 61 and the torpedo 63 are stably held in the heating cylinder head 32. The method of attaching the injection nozzle 33 to the heating cylinder head 32 is not limited to screwing, and other methods may be used.

1 ... Injection molding machine for foam molding, 2 ... Frame, 3 ... Mold opening / closing / molding unit, 4 ... Injection device, 5 ... Physical foaming agent supply device, 11 ... Tailstock, 12 ... Fixed die plate, 13 ... Movable die Plate, 14 ... Toggle link mechanism, 15 ... Tie bar, 16 ... Fixed side mold, 17 ... Movable side mold, 18 ... Mold opening / closing / mold clamping electric, 20 ... Mold thickness adjustment motor, 31 ... Heating cylinder, 32 ... heating cylinder head, 33 ... injection nozzle, 34 ... screw, 35 ... band heater, 36 ... hopper block, 37 ... screw drive unit, 38 ... hopper, 39 ... nozzle touch / back motor, 41 ... screw body, 42 ... Screw head, 43 ... Check ring mechanism, 44 ... Check sheet, 45 ... Check ring, 52 ... First nozzle mounting hole, 53 ... Second nozzle mounting hole, 61 ... Sleeve, 61a ... Cylindrical part, 61b, 61c ... Flange part, 61d ... Center hole, 61e ... Reinforcing part, 61f ... Physical foaming agent introduction space, 62 ... Needle, 62a ... Male screw, 62b ... Physical foaming agent introduction space, 63 ... Torpedo, 63a ... Female screw, 63b ... Physical foaming agent Introduction hole, 63c ... Resin flow hole, 71 ... Gas cylinder, 72 ... Supercritical fluid generator, 73 ... First foaming agent supply nozzle, 74 ... Second foaming agent supply nozzle, 75 ... Pipe line, 76 ... On-off valve ..

Claims (4)

A screw equipped with a check ring mechanism to prevent backflow on the tip side,
A heating cylinder in which the screw is stored so that it can rotate and move forward and backward,
A heating cylinder head provided at the tip of the heating cylinder and
An injection nozzle connected to the tip of the heating cylinder head and
A foaming agent supply nozzle that supplies the physical foaming agent attached to the heating cylinder head, and
A sleeve that is at least partially formed of a porous material and has a center hole with a resin passage in the center.
A mixture of the plasticized resin stored in the measuring resin reservoir from the tip of the screw to the tip of the injection nozzle and the physical foaming agent supplied from the foaming agent supply nozzle is placed in the cavity of the mold. In the injection device of an injection molding machine for foam molding, which injects and fills the foam to form the required foam molded product.
The sleeve is housed in the heating cylinder head, and at least a part of the sleeve is formed of a porous material in the center hole formed in the sleeve, and the physical foaming agent is supplied to the center from the foaming agent supply nozzle. introducing space accommodates a needle which is provided for,
The needle is held by a torpedo housed in the heating cylinder head and arranged at the center of the center hole, and the torpedo is physically communicated with the resin flow hole communicating with the center hole and the introduction space. An injection device of an injection molding machine for foam molding , which comprises an introduction hole for a foaming agent. The injection device of an injection molding machine for foam molding according to claim 1 , wherein the needle is formed as a separate body independent of the torpedo and is screwed to the torpedo. The injection of the injection molding machine for foam molding according to claim 1, wherein an introduction space for a physical foaming agent supplied from the foaming agent supply nozzle is formed between the heating cylinder head and the sleeve. apparatus. The foaming agent supply nozzle is provided at the center of the needle and the first foaming agent supply nozzle that supplies the physical foaming agent into the introduction space formed between the heating cylinder head and the sleeve. The injection device for an injection molding machine for foam molding according to claim 3 , further comprising a combination of a second foaming agent supply nozzle that supplies a physical foaming agent into the introduction space.

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