WO2018211863A1

WO2018211863A1 - Injection device of injection molding machine for foam molding

Info

Publication number: WO2018211863A1
Application number: PCT/JP2018/015048
Authority: WO
Inventors: 靖丈澤田; 井上　玲
Original assignee: 東洋機械金属株式会社
Priority date: 2017-05-18
Filing date: 2018-04-10
Publication date: 2018-11-22
Also published as: CN110621465B; JP2018192715A; JP6893828B2; CN110621465A

Abstract

An injection device (4) is provided with: a heating cylinder (31) in which a screw (34) is accommodated; a heating cylinder head (32) provided at a tip end of the heating cylinder; and an injection nozzle (33) coupled to a tip end of the heating cylinder head. The heating cylinder head accommodates a sleeve (61) partially made of porous sintered metal material, and a needle (62) partially made of porous sintered metal material is arranged inside a center hole (61d) formed in the sleeve. Thus, a physical foaming agent supplied from a physical foaming agent supplying device (5) is introduced into a plasticized resin stored in a metering resin storing part (54), from both the outer peripheral side and the inner peripheral side of the center hole.

Description

Injection device for injection molding machine for foam molding

The present invention relates to an injection apparatus 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 firstly, as an injection device of an injection molding machine for foam molding using CO ₂ gas, N ₂ gas or the like in a supercritical state as a foaming agent, at least partly has a porous material in the heating cylinder head. A sleeve formed with a center hole that constitutes a part of the resin passage is incorporated in a portion formed with the porous material, and foamed between the outer peripheral surface of the sleeve and the inner peripheral surface of the heating cylinder head. The thing which formed the introduction space of an agent was proposed (for example, refer patent document 1). In the present specification, a 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 has a fine portion of the sleeve formed of the porous material. It is supplied to the center hole and the resin passage through the open 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 established in the heating cylinder head. Since the contact area between the agent and the plasticizing resin can be expanded, the diffusion rate of the physical foaming agent into the plasticizing resin can be increased, and the shot cycle can be shortened and the molded product can be homogenized.

JP 2012-232558 A

However, the injection molding machine for foam molding is 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 plasticized resin.

The present invention was made to solve such problems of the prior art, and the purpose thereof is to rapidly diffuse the physical foaming agent into the plasticized resin stored in the heating cylinder head, An object of the present invention is to provide an injection apparatus for an injection molding machine for foam molding with high productivity of foam molded products.

In order to solve the above problems, the present invention provides a screw having a check ring mechanism for preventing backflow on the tip side, a heating cylinder in which the screw is rotatable and can be moved forward and backward, and a tip portion of the heating cylinder A heating cylinder head provided on the heating cylinder head, an injection nozzle connected to a tip of the heating cylinder head, a blowing agent supply nozzle for supplying a physical foaming agent attached to the heating cylinder head, and at least partly porous A sleeve formed with a material and having a center hole having a resin passage in the center, and a plasticized resin stored in a metered resin reservoir from the tip of the screw to the tip of the injection nozzle; Injection of a foam molding injection molding machine for molding a desired foam molding by injection filling a mixture of the physical foaming agent supplied from the foaming agent supply nozzle into a cavity of a mold The sleeve is accommodated in the heating cylinder head, and at least a part thereof is formed of a porous material in the center hole formed in the sleeve, and is supplied from the foaming agent supply nozzle to the center portion. A needle provided with a space for introducing a physical foaming agent is accommodated.

According to the above configuration, since the sleeve having the center hole formed at least in part with the porous material and having the resin passage at the center is accommodated in the heating cylinder head, the physical foaming injected from the foaming agent supply nozzle The agent spreads in the surface direction of the sleeve through the fine holes of the sleeve and is uniformly ejected from the entire circumference of the center hole to the plasticized resin stored in the metering resin reservoir. Further, according to the above configuration, since the needle having at least a part formed of a porous material and provided with a physical foaming agent introduction space in the center is accommodated in the center hole, the physical sprayed from the foaming agent supply nozzle The foaming agent first enters the introduction space and spreads in the length direction of the needle. Furthermore, the physical foaming agent supplied in the introduction space spreads in the surface direction of the needle through the fine pores of the needle. The resin is uniformly ejected from the entire circumference of the center hole into the plasticized resin stored in the weighing resin reservoir. As described above, according to the above configuration, since the plasticizing resin stored in the weighing resin reservoir is uniformly ejected from both the outer circumferential direction and the inner circumferential direction of the center hole, the weighing is performed only from the outer circumferential direction of the center hole. Compared with the case where the physical foaming agent is supplied to the plasticized resin stored in the resin reservoir, the contact area between the plasticized resin and the physical foaming agent can be increased. Therefore, the physical foaming agent can be diffused quickly and uniformly into the plasticized resin, and the productivity of the foam molded product having the required quality can be increased.

Further, the present invention is the foam molding injection molding machine having the above-described configuration, wherein the needle is held by a torpedo accommodated in the heating cylinder head and disposed at a center portion of the center hole, and the torpedo is It has a resin circulation hole communicating with the hole, and a physical foaming agent introduction hole communicating with the introduction space.

According to the above configuration, since the needle is held using the torpedo accommodated in the resin passage, the needle can be stably held in the center hole. Further, according to the above configuration, since the needle is disposed at the center of the center hole formed in the sleeve, the physical foaming agent can be diffused more uniformly into the plasticized resin.

Further, the present invention is characterized in that in the foam molding injection molding machine having the above-described configuration, the needle is formed as a separate body independent of the torpedo and 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 separate separate 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 to the case, each part can be easily manufactured, and the total manufacturing cost can be reduced. Further, when the needle or torpedo is damaged, only necessary members need to be replaced. Furthermore, according to the said structure, since a needle is screwed to a torpedo, the assembly operation | work of a needle and a torpedo can be performed easily.

Further, the present invention is characterized in that, in the foam molding injection molding machine configured as described above, a space for introducing 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 spread in the length direction of the heating cylinder head, and then Through the fine holes of the sleeve, the resin is uniformly ejected from the entire circumference of the center hole to the plasticized resin stored in the metering resin reservoir. Therefore, the physical foaming agent can be diffused more rapidly and uniformly into the plasticized resin than when the physical foaming agent introduction space is not formed between the heating cylinder head and the sleeve.

In the foam molding injection molding machine having the above-described configuration, the foaming agent supply nozzle may supply a physical foaming agent into the introduction space formed between the heating cylinder head and the sleeve. And a second foaming agent supply nozzle for supplying a physical foaming agent into the introduction space provided at the center of the needle.

According to the above configuration, since the injection molding machine for foam molding has two foaming agent supply nozzles, a predetermined amount of physical foaming agent can be plasticized in a shorter time than when only one foaming agent supply nozzle is provided. It can be introduced into the resin.

Since the present invention can supply a physical foaming agent into the plasticized resin stored in the center hole from both the outside and the inside of the center hole constituting a part of the resin passage, the physical foaming agent for the plasticized resin Can be accelerated, and the diffusion of the physical foaming agent into the plasticized resin can be made uniform. Therefore, according to the present invention, a foam-molded product having a required quality can be manufactured with high efficiency.

It is a block diagram of the injection molding machine for foam molding containing the injection apparatus which concerns on embodiment. It is a principal part expanded sectional view of the injection device concerning an 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 needle | hook and torpedo threaded state which concern on embodiment. FIG. 6 is a cross-sectional view taken along line AA in FIG. 5.

Hereinafter, an embodiment of an injection device according to the present invention will be described with reference to the drawings. In addition, embodiment described below shows an example at the time of actualizing this invention, Comprising: The range of this invention is not limited within the range of description of embodiment. Therefore, the present invention can be implemented with various modifications added to the embodiments.

First, the whole of an injection molding machine 1 for foam molding provided with an injection apparatus according to the embodiment will be described with reference to FIG. As shown in FIG. 1, the foam molding injection molding machine 1 in this example supplies a mold opening / closing / clamping unit 3 and an injection device 4 which are disposed opposite to each other on a frame 2, and supplies a physical foaming agent to the injection device 4. And a physical foaming agent supply device 5.

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

The tail stock 11 is mounted with an electric servomotor 18 for mold opening / closing and clamping, and a nut body 19a of a ball screw mechanism 19 is rotatably attached. A screw shaft 19b of the ball screw mechanism 19 is screwed to 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 main shaft of the mold opening / closing / clamping electric servomotor 18 is connected to a nut body 19a of a ball screw mechanism 19 through an appropriate rotation transmission mechanism such as a timing belt. Therefore, when the mold opening / closing / clamping electric servomotor 18 is rotated forward or backward, the toggle link mechanism 14 is extended or contracted via the ball screw mechanism 19 and the cross head 14a, and the fixed mold 16 and the movable mold 16 are moved. Opening and closing 17 and mold clamping are performed.

In addition, 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 an end of the tie bar 15 is rotatable. Provided. The main shaft of the mold thickness adjusting motor 20 is connected to the gear portion 21a of the mold thickness adjusting nut 21 through an appropriate rotation transmission mechanism. Therefore, when the mold thickness adjusting motor 20 is rotated forward or reverse with the tail stock 11 being fixed to the frame 2, the mold thickness adjusting nut 21 is moved in the length direction of the tie bar 15, and the tail stock is fixed to the frame 2. 11 setting positions are adjusted. Thereby, the mold thickness adjustment after exchanging the fixed mold 16 and / or the movable mold 17 can be performed.

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. A screw 34 is housed inside the heating cylinder 31 so as to be rotatable and movable forward and backward. A band heater 35 is wound around the outer periphery of the heating cylinder 31. The heating cylinder 31 is attached to a hopper block 36, and the hopper block 36 is provided with a screw driving portion 37 that is a driving source of the screw 34 and a hopper 38 that stores a raw material resin. The heating cylinder 31 is supplied with the raw material resin stored in the hopper 38 inside the hopper block 36. The hopper block 36 is driven forward and backward to a nozzle touch position or a nozzle back position by a nozzle touch / back motor 39 provided on the frame 2.

The heating cylinder 31 cooperates with the screw 34 to draw, 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 driving 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 frictional heat and shearing heat generated with the rotation of the screw 34 and electric heat provided by the band heater 35. The plasticized resin is sequentially transferred to the front end side of the heating cylinder 31 by the screw feeding action of the screw 34, and the amount of resin necessary for one injection is measured. Then, after a predetermined amount of plasticized resin is stored at the tip of the heating cylinder 31, the screw 34 is driven forward, and the predetermined amount of plasticized resin stored at the tip of the heating cylinder 31 is fixed to the fixed mold. Injected into a cavity formed between 16 and the movable mold 17.

As shown in an enlarged view in FIG. 2, the screw 34 includes a screw main body 41 having a screw groove 41 a formed on the outer peripheral surface, 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 disposed 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 loosely fitted to the screw main body 41 so as to be able to move forward and backward and to be rotatable.

In the plasticizing process of the raw material resin, the check ring 45 is moved away from the check sheet 44 by the pressure of the plastic resin transferred from the screw body 41 side to the screw head 42 side, and the check ring mechanism 43 is automatically Automatically switched to the conductive state. Therefore, the plasticizing resin transferred from the screw main body 41 side passes through a gap (not shown) provided between the screw main body 41 and the check ring 45 and is transferred to the distal end side of the screw head 42. 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 a non-conductive state. Accordingly, the backflow of the plasticized resin at the time of metering and injection of the plasticized resin is prevented.

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

The heating cylinder head 32 is formed in a cylindrical shape as shown in FIG. 2, 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 physical foaming agent introduction holes. 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 placed in the weighing resin reservoir 54 from the check ring 45 to the tip of the injection nozzle 33. The sleeve 61 that supplies the plasticized resin dispersedly and the physical foaming agent supplied from the physical foaming agent supply device 5 through the second nozzle mounting hole 53 are stored in the metered resin reservoir 54. The needle 62 dispersed and supplied to the fluorinated resin and the torpedo 63 for holding the needle 62 are accommodated.

As shown in FIGS. 3 and 4, the sleeve 61 includes a cylindrical portion 61 a and

flange portions

61 b and 61 c formed at both ends thereof, and passes through from the end surface of the flange portion 61 b to the end surface of the flange portion 61 c. 61d is established. 3 and 4, the outer diameter of the flange portion 61b is formed larger than the outer diameter of the flange portion 61c, but the gist of the present invention is not limited to this. In other words, the outer diameters of the

flange portions

61b and 61c only need to be formed in the heating cylinder head 32 so that the sleeve 61 can be stably held. The sleeve 61 is accommodated in the heating cylinder head 32 so that the center in the length direction of the cylindrical portion 61 a substantially coincides with the central axis of the first nozzle mounting hole 52 formed in the heating cylinder head 32.

As described above, the sleeve 61 of this example is composed of the small-diameter cylindrical portion 61a and the large-

diameter flange portions

61b and 61c formed at both ends thereof. When installed at a predetermined position, a ring-shaped physical foaming agent introduction space 61 f 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 surface direction of the cylindrical portion 61a.

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. In this way, when the entire cylindrical portion 61a is formed of a porous sintered metal material, the physical foaming agent can be supplied into the weighing resin reservoir portion 54 through the entire cylindrical portion 61a, so that it is stored in the weighing resin reservoir portion 54. The diffusion rate of the physical foaming agent into the plasticized resin can be maximized, and the productivity of the foam molded product can be optimized. Further, since the porosity of the cylindrical portion is 5% to 60%, the physical foaming agent can be quickly and sufficiently ejected into the plasticized resin, and the mechanical strength of the sleeve 61 is kept appropriate. be able to.

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

3 and 4 can be manufactured by laser processing. That is, when high-level laser is irradiated to metal powder (including alloy powder), the metal powder is completely melted by the heat and solidified to become a bulk material, and when irradiated with low-level laser, the metal powder is heated by the heat. Since only a part of the metal powder is melted and becomes a porous sintered metal after solidification, a metal powder layer having a predetermined thickness is formed on the work table in a ring shape, and then in the circumferential direction of the metal powder layer. By irradiating a laser at an appropriate level along the whole, the entire circumferential direction of the metal powder layer can be made into a porous sintered metal or a bulk material. In addition, by appropriately switching the laser power with respect to the circumferential direction of the metal powder layer, it is possible to alternately form the porous sintered metal portion and the bulk material portion in the circumferential direction. Therefore, the sleeve 61 having the required shape can be manufactured by repeating the lamination of the metal powder layers in the thickness direction and the laser irradiation of each metal powder layer, and finally performing the 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 cylindrical shape having an external thread 62a at one end, and at least a portion excluding the external thread 62a is porous with a porosity of 5% to 60%. It is formed with a sintered metal material. At the center of the needle 62, a physical foaming agent introduction space 62b penetrating the end of the male screw 62a is formed. The introduction space 62 b has a function of expanding 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 produced by the same method 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 62 a of the needle 62 is screwed into the center of one end. A female screw 63a is formed. Further, in the torpedo 63, when the torpedo 63 is accommodated at a predetermined position in the heating cylinder head 32, the center portion of the female screw 63a is located from the position facing the second nozzle mounting hole 53 provided in the heating cylinder head 32. A physical foaming agent introduction hole 63b extending to the center of the sleeve 61 and a resin flow hole 63c communicating with the center hole 61d provided in the sleeve 61 are provided. The needle 62 is integrated with the torpedo 63 by screwing the male screw 62a with the female screw 63a. As shown in FIG. 2, the torpedo 63 into which the needle 62 is screwed is accommodated in the heating cylinder head 32 with the needle 62 disposed in the center hole 61 d 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 reduced as much as possible. Therefore, in the torpedo 63 of this example, as shown in FIG. 6, the four resin circulation holes 63 c formed in a fan shape are equally arranged on the circumference centering on the axis O of the torpedo 63. Yes. The shape of the resin circulation hole 63c is not limited to a fan shape, and the number of the resin circulation holes 63c can be changed as appropriate without any problem even when the shape is round.

As shown in FIG. 1, the physical foaming agent supply device 5 includes a gas cylinder 71 for storing a source gas such as CO ₂ gas and N ₂ gas, and a source gas supplied from the gas cylinder 71 at a high temperature and a high pressure to achieve physical properties in a supercritical state. From a supercritical fluid generator 72 as a foaming agent, a first foaming agent supply nozzle 73 for injecting a physical foaming agent supplied from the supercritical fluid generator 72 into the introduction space 61f, and the supercritical fluid generator 72 Pipe line connecting the second blowing agent supply nozzle 74 for injecting the supplied physical blowing agent into the introduction space 62b, the supercritical fluid generator 72, and the first and second blowing

agent supply nozzles

73, 74. And an on-off valve 76 provided in 75.

The first blowing agent supply nozzle 73 is attached to the first nozzle mounting hole 52 provided in the heating cylinder head 32, and the second blowing agent supply nozzle 74 is provided in the second nozzle opening hole provided in the heating cylinder head 32. It is attached to the nozzle attachment hole 53. The first foaming agent supply nozzle 73 is attached to the first nozzle mounting hole 52 by, for example, engraving a female screw in the first nozzle mounting hole 52 and a male screw on the outer periphery of the tip of the first foaming agent supply nozzle 73. Can be carried out by engraving and screwing the male screw into the female screw. The second blowing agent supply nozzle 74 can be attached to the second nozzle attachment hole 53 in the same manner. The supply of the physical foaming agent into the heating cylinder head 32 is performed by opening the on-off valve 76 during the metering process of each shot performed by the foam molding injection molding machine 1 or after the metering process is completed.

The physical foaming agent injected into the introduction space 61f from the first foaming agent supply nozzle 73 is a fine part of the cylindrical portion 61a formed in the sleeve 61 and formed from a porous sintered metal material. The center hole 61d of the sleeve 61 is reached through a simple hole. Further, the physical foaming agent sprayed from the second foaming agent supply nozzle 74 is supplied into the introduction space 62b of the needle 62 through the introduction hole 63b provided in the torpedo 63, and the fine holes of the needle 62 are provided. And reaches the center hole 61d of the sleeve 61. As a result, the physical foaming agent comes into contact with the plasticized resin stored in the metering resin reservoir 54, and the physical foaming agent is diffused into the plasticized resin.

After the metering step, when the screw 34 is driven forward, a plasticizing resin 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 produced.

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

The injection device 4 according to the embodiment is configured to supply a physical foaming agent to the plasticized resin stored in the metering resin reservoir 54 from both the outer peripheral side and the inner peripheral side of the center hole 61d provided in the sleeve 61. have.
Therefore, the injection device 4 according to the embodiment is plasticized as compared with a conventional foam molding injection molding machine that supplies a physical foaming agent into the plasticized resin only from the outer peripheral side of the center hole 61d provided in the sleeve 61. The diffusion rate of the physical foaming agent into the resin can be increased, and the productivity of the foamed molded product can be increased.

In addition, the injection device 4 according to the embodiment discloses a configuration in which the needle 62 is held by a torpedo 63 accommodated in the heating cylinder head 32 and is arranged in the center portion of the center hole 61 d opened in the sleeve 61. Yes.
Therefore, since the injection device 4 according to the embodiment can stably hold the needle 62 in the center portion of the center hole 61d, the physical foaming agent is more diffused into the plasticized resin stored in the metering resin reservoir portion 54. It can be uniform.

Moreover, the injection device 4 according to the embodiment has a configuration in which the needle 62 and the torpedo 63 are formed as separate separate bodies, and these members are assembled together by screwing.
Therefore, the injection device 4 according to the embodiment can facilitate the manufacture of the needle 62 and the torpedo 63, and when either the needle 62 or the torpedo 63 is damaged, it is only necessary to replace only necessary members. Excellent. Moreover, since the injection apparatus 4 which concerns on embodiment integrates the needle 62 and the torpedo 63 by screwing, the assembly operation | work of the needle 62 and the torpedo 63 can be performed easily.

The injection device 4 according to the embodiment has a configuration in which a physical foaming agent introduction space 61 f is formed between the heating cylinder head 32 and the sleeve 61.
Therefore, in the injection device 4 according to the embodiment, the physical foaming agent supplied from the first foaming agent supply nozzle 73 is expanded in the length direction of the heating cylinder head 32 and then stored in the weighing resin reservoir 54. Therefore, the diffusion of the physical foaming agent into the plasticized resin can be made quicker and more uniform.

The injection device 4 according to the embodiment includes a first foaming agent supply nozzle 73 that supplies a physical foaming agent into an introduction space 61f formed between the heating cylinder head 32 and the sleeve 61, and the center of the needle 62. And a second foaming agent supply nozzle 74 for supplying a physical foaming agent into an introduction space 62b provided in the section.
Therefore, the injection device 4 according to the embodiment can introduce a predetermined amount of the physical foaming agent into the plasticized resin in a short time compared to a case where only one foaming agent supply nozzle is provided.

Note that the scope of the present invention is not limited to the configuration of the embodiment described above. For example, in the above-described embodiment, the needle 62 and the torpedo 63 are integrated by screwing. However, 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 separate bodies, but the needle 62 and the torpedo 63 can be integrally formed instead of such a configuration. Even with such a configuration, the diffusion rate of the physical foaming agent into the plasticized resin can be increased.

The injection nozzle 33 is attached to the tip of the heating cylinder head 32 by a method such as screwing, and one end is abutted against the end of the torpedo 63. Thereby, 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.

DESCRIPTION OF SYMBOLS 1 ... Injection molding machine for foam molding, 2 ... Frame, 3 ... Mold opening / closing and clamping unit, 4 ... Injection device, 5 ... Physical foaming agent supply device, 11 ... Tail stock, 12 ... Fixed die plate, 13 ... Movable die Plate ... 14 Toggle link mechanism, 15 ... tie bar, 16 ... fixed side mold, 17 ... movable side mold, 18 ... electric for mold opening / closing and clamping, 20 ... motor for adjusting mold thickness, 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 ... Motor for nozzle touch / back, 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, 6 a ... 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 ... Open / close valve.

Claims

A screw having a check ring mechanism for preventing backflow on the tip side;
A heating cylinder in which the screw is rotatable and can be moved forward and backward; and
A heating cylinder head provided at the tip of the heating cylinder;
An injection nozzle connected to the tip of the heating cylinder head;
A foaming agent supply nozzle for supplying a physical foaming agent attached to the heating cylinder head;
A sleeve having at least a part formed of a porous material and having a center hole having a resin passage in the center,
A mixture of the plasticizing resin stored in the metering 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 mold cavity. In an injection apparatus of an injection molding machine for foam molding, which is injection-filled to form a required foam molded article,
A physical foaming agent that accommodates the sleeve in the heating cylinder head, is formed with a porous material in the center hole formed in the sleeve, and is supplied from the foaming agent supply nozzle to the center portion. An injection device for an injection molding machine for foam molding, characterized in that a needle provided with an introduction space is accommodated.
The needle is held by a torpedo accommodated in the heating cylinder head and disposed at the center of the center hole, and the torpedo communicates with a resin circulation hole communicating with the center hole and a physical communicating with the introduction space. The injection device for an injection molding machine for foam molding according to claim 1, further comprising an introduction hole for a foaming agent.
3. The injection apparatus for an injection molding machine for foam molding according to claim 2, wherein the needle is formed separately from the torpedo and is screwed to the torpedo.
The injection of a foam molding injection molding machine according to claim 1, wherein a space for introducing 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 a first foaming agent supply nozzle that supplies a 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 4, comprising a combination with a second foaming agent supply nozzle for supplying a physical foaming agent into the introduction space.