CN106113399B - Injection nozzle, injection device, Coinjection molding apparatus, injecting method and injection moulding method - Google Patents

Abstract

The present invention provides the injection nozzle for the irregular colour that can be adequately suppressed molded product.Injection nozzle (10) has outer barrel (20) and inner cylinder (40).Inner cylinder (40) contains：2nd end (43) of the 1st end (42) and nozzle head (30) side that multiple through holes (51,52,53) that molten resin reservoir (46) is connected to peripheral surface (45), the multiple protrusions (55,56,57) being provided on peripheral surface (45), molten resin are flowed into.So that the flow-rate ratio of the molten resin of through hole by being located at the 2nd end side (43) constitutes multiple through holes (51,52,53) by the small mode of the flow for being located at the molten resin of the through hole of the 1st end (42) side.

Description

Injection nozzle, injection device, injection molding device, injection method, and injection molding method

technical field

The invention relates to an injection nozzle, an injection device, an injection molding device, an injection method and an injection molding method.

Background technique

Used plastics recovered from used electrical products etc. are sorted into resin pellets for recycling. Various colors are used for the resin parts used in the product. Therefore, resin pellets for recycling have various colors. When such recycled resin pellets having various colors are used to produce molded articles by molding processing methods such as injection molding, color unevenness occurs in the molded articles. Therefore, it is known that a plurality of channels for molten resin are provided in the injection nozzle of an injection molding apparatus, and the molten resin that melts the resin pellets for regeneration is repeatedly divided into a plurality of channels and then merged again, whereby the molten resin is melted. The resin is kneaded to suppress color unevenness of molded products (see JP-A-11-34108 and JP-A-2004-17335).

Contents of the invention

However, even if the injection nozzles described in JP-A-11-34108 and JP-A-2004-17335 are used, color unevenness of molded articles cannot be sufficiently suppressed.

The present invention was made in view of the above-mentioned problems, and an object of the present invention is to provide an injection nozzle, an injection device, an injection molding device, an injection method, and an injection molding method capable of sufficiently suppressing color unevenness of a molded product.

The injection nozzle of the present invention includes an outer cylinder having a nozzle tip, and an inner cylinder arranged inside the outer cylinder. The inner cylinder includes: a molten resin storage portion for storing molten resin, an outer peripheral surface, a plurality of through holes connecting the molten resin storage portion and the outer peripheral surface, a plurality of protrusions provided on the outer peripheral surface, a first end portion into which the molten resin flows, and the second end on the nozzle head side compared to the first end. The plurality of through holes are formed such that the flow rate of molten resin passing through the through hole located on the second end side is smaller than the flow rate of molten resin passing through the through hole located on the first end side.

The injection nozzle of the present invention includes an outer cylinder having a nozzle tip, and an inner cylinder arranged inside the outer cylinder. The inner cylinder includes: a molten resin storage portion for storing molten resin, an outer peripheral surface, a plurality of through holes connecting the molten resin storage portion and the outer peripheral surface, a plurality of protrusions provided on the outer peripheral surface, a first end portion into which the molten resin flows, and the second end on the nozzle head side compared to the first end. The total area in the circumferential direction of the inner cylinder of the through-hole located on the second end side is smaller than the total area in the circumferential direction of the inner cylinder of the through-hole located on the first end side.

The injection device of the present invention includes the injection nozzle as described above.

The injection molding apparatus of the present invention includes the above-mentioned injection apparatus and mold clamping apparatus.

The injection method of the present invention includes: melting the resin; supplying the first molten resin as a part of the melted resin to the injection nozzle; supplying the second molten resin as a part of the melted resin to the injection nozzle after the first molten resin. Injection nozzle; in the injection nozzle, the flow rate of the first molten resin is relatively smaller than that of the second molten resin; in the injection nozzle, the flow rate of the first molten resin is relatively smaller than that of the second molten resin and kneading of the second molten resin; injecting the kneaded first molten resin and second molten resin from the injection nozzle.

The injection molding method of the present invention includes: injecting the kneaded first molten resin and the second molten resin into the mold by the above-mentioned injection method; cooling the first molten resin and the second molten resin injected into the mold to obtain the Cured moldings.

The above-mentioned and other objects, features, aspects, and advantages of this invention will become clear from the following detailed description related to this invention, which can be understood in conjunction with the accompanying drawings.

Description of drawings

FIG. 1 is a schematic partial cross-sectional view of an injection molding apparatus according to Embodiment 1 of the present invention.

2 is a schematic cross-sectional view of the injection nozzle according to Embodiment 1 of the present invention.

3 is a schematic perspective view of an inner cylinder of the injection nozzle according to Embodiment 1 of the present invention.

4A is a diagram showing a flowchart of the injection molding method according to Embodiment 1 of the present invention. 4B is a diagram showing a flowchart of the injection method according to Embodiment 1 of the present invention.

5 is a schematic perspective view of an inner cylinder of an injection nozzle according to Embodiment 2 of the present invention.

6 is a schematic cross-sectional view of an injection nozzle according to Embodiment 3 of the present invention.

7 is a schematic perspective view of an inner cylinder of an injection nozzle according to Embodiment 4 of the present invention.

8A is a schematic perspective view of an inner cylinder of an injection nozzle according to Embodiment 5 of the present invention. 8B is an enlarged view of first to third protrusions in Embodiment 5 of the present invention.

Detailed ways

Embodiments of the present invention will be described below based on the drawings.

(Embodiment 1)

Referring to FIG. 1 , an injection molding apparatus 1 according to this embodiment mainly includes an injection apparatus 2 and a mold clamping apparatus 80 .

The injection device 2 mainly includes a hopper 3 , a barrel 4 , a first heater 5 , a screw 6 , a first drive unit 7 , a screw head 9 , and an injection nozzle 10 .

The hopper 3 stores resin materials such as resin pellets for regeneration. The hopper 3 is connected to the cylinder 4 , and a resin material such as resin pellets for regeneration is supplied to the hollow portion 4 c of the cylinder 4 .

The cartridge 4 has a cylindrical shape having openings at both ends 4a, 4b. The end portion 4b is located on the injection nozzle 10 side, and the end portion 4a is located on the opposite side to the end portion 4b. The cartridge 4 has a hollow portion 4c inside, which extends between the end portion 4a and the end portion 4b.

A first heater 5 is provided on the outer peripheral surface of the cylinder 4 . The first heater 5 heats the resin material in the hollow portion 4 c of the cylinder 4 . To the resin material, not only the heat of the first heater 5 but also the frictional heat generated by the rotation of the screw 6 and the like are applied. These heats plasticize the resin material supplied from the hopper 3 . In this specification, the plasticized resin is referred to as molten resin.

A screw 6 is disposed in the hollow portion 4c of the cylinder 4, and the screw 6 has a spiral groove formed on the surface thereof. A first drive unit 7 for driving the screw 6 is provided at the end 4 a of the barrel 4 . The screw 6 is rotated while moving in the direction in which the cylinder 4 extends by the first drive unit 7 . The resin material supplied from the hopper 3 can be sent to the injection nozzle 10 side by rotating the screw 6 . The molten resin can be injected from the injection nozzle 10 by moving the screw 6 toward the injection nozzle 10 side.

A check valve 8 may be provided on the injection nozzle 10 side of the screw 6 . The check valve 8 prevents the molten resin from flowing to the first drive unit 7 . A screw head 9 is provided at the end of the screw 6 on the injection nozzle 10 side. The screw head 9 can have the shape of a cone that tapers towards the injection nozzle 10 .

An injection nozzle 10 is provided at the end 4 b of the cartridge 4 . Referring to FIGS. 1 and 2 , the injection nozzle 10 mainly includes an outer cylinder 20 and an inner cylinder 40 . The injection nozzle 10 may further include a second heater 35 . The second heater 35 can keep the resin in the injection nozzle 10 in a molten state.

The outer cylinder 20 may have a main body portion 21 and a nozzle tip 30 . The nozzle head 30 may be integrally formed with the main body part 21 . The nozzle head 30 may also be formed as a separate member from the main body 21 and then be mechanically connected to the main body 21 . The inner diameter and outer diameter of the main body part 21 may be larger than the inner diameter and outer diameter of the nozzle tip 30 . The outer cylinder 20 has a first end portion 22 on the cartridge 4 side and a second end portion 23 on the nozzle head 30 side. The outer cylinder 20 is a cylindrical member extending between the first end portion 22 and the second end portion 23 . The outer cylinder 20 has an inner peripheral surface 24 and an outer peripheral surface 25 . The second heater 35 may be provided on the outer peripheral surface 25 of the outer cylinder 20 .

The outer cylinder 20 may have a tapered portion 27 connecting the main body portion 21 with the nozzle head 30 . The outer cylinder 20 may have an inner protrusion 26 on the first end 22 side of the outer cylinder 20 . The surface of the inner protrusion 26 on the first end 22 side of the inner protrusion 26 may have an outer surface 26a. The outer surface 26a may be a conical surface capable of receiving the screw head 9 . The surface of the inner protrusion 26 on the second end 23 side of the inner protrusion 26 may have an inner surface 26b.

The configuration of the inner cylinder 40 will be described with reference to FIGS. 2 and 3 . The cross-sectional view of the inner cylinder 40 in FIG. 2 is a cross-sectional view on the section line II-II shown in FIG. 3 . The inner cylinder 40 may have a main body portion 41 , a molten resin storage portion 46 , a flange 47 and a tapered portion 48 . The inner cylinder 40 has a first end 42 on the cartridge 4 side and a second end 43 on the nozzle head 30 side. The inner cylinder 40 is a cylindrical member extending between the first end portion 42 and the second end portion 43 . The first end portion 42 of the inner cylinder 40 may be in contact with the inner surface 26 b of the inner protrusion 26 of the outer cylinder 20 . The inner cylinder 40 has an inner peripheral surface 44 and an outer peripheral surface 45 . The outer diameter of the main body portion 41 of the inner cylinder 40 is smaller than the inner diameter of the main body portion 21 of the outer cylinder 20 . The outer peripheral surface 45 of the inner cylinder 40 is located inside the inner peripheral surface 24 of the outer cylinder 20 . The molten resin reservoir 46 defined by the inner peripheral surface 44 of the inner cylinder 40 extends to the first end 42 , and the molten resin reservoir 46 has a large opening on the first end 42 side. The molten resin in the cylinder 4 (see FIG. 1 ) flows into the molten resin storage portion 46 from the first end portion 22 of the outer cylinder 20 and the first end portion 42 of the inner cylinder 40 . The molten resin storage part 46 receives molten resin from the cylinder 4, and temporarily stores it. The molten resin reservoir 46 may have a tapered shape (for example, a conical shape) toward the second end 43 on the side of the second end 43 .

A flange 47 is provided on the second end portion 43 side of the main body portion 41 . The flange 47 has a larger outer diameter than the main body portion 41 . The flange 47 may be in contact with the inner peripheral surface 24 of the main body portion 21 of the outer cylinder 20 . A tapered portion 48 may be provided on the second end portion 43 side of the flange 47 . The tapered portion 48 becomes tapered toward the second end portion 43 . The outer peripheral surface of the tapered portion 48 of the inner cylinder 40 may be in contact with the tapered portion 27 of the outer cylinder 20 . One or more penetration portions 49 are provided on the flange 47 and the tapered portion 48 . The penetration portion 49 connects the surface of the flange 47 on the first end portion 42 side and the surface of the tapered portion 48 on the second end portion 43 side.

The inner cylinder 40 includes a plurality of through holes (the first through hole 51 , the second through hole 52 and the third through hole 53 ) that communicate the molten resin reservoir 46 and the outer peripheral surface 45 . Specifically, the main body portion 41 of the inner tube 40 is provided with a first through hole 51 , a second through hole 52 , and a third through hole 53 . The second through hole 52 is located on the second end portion 43 side (downstream side of the molten resin, nozzle head 30 side) compared to the first through hole 51 , and the third through hole 53 is connected to the second through hole 53 . The hole 52 is located on the side of the second end portion 43 (the downstream side of the molten resin, the side of the nozzle head 30 ). In this embodiment, the size of the through hole (for example, the third through hole 53 ) located on the second end portion 43 side is smaller than the size of the through hole (for example, the first through hole 51 ) located on the first end portion 42 side. More specifically, the dimensions of the plurality of through holes (the first through hole 51 , the second through hole 52 , and the third through hole 53 ) become smaller as approaching the second end portion 43 from the first end portion 42 . Specifically, the size of the second through hole 52 is smaller than that of the first through hole 51 . The size of the third through hole 53 is smaller than that of the second through hole 52 . The size of the third through hole 53 is smaller than that of the first through hole 51 .

One or more first through-holes 51 , second through-holes 52 , and third through-holes 53 are respectively provided in the circumferential direction of the inner tube 40 . In this embodiment, the first through-holes 51 , the second through-holes 52 , and the third through-holes 53 are respectively provided in the same number in the circumferential direction of the inner cylinder 40 . A plurality of through holes (the first through hole 51, the second through hole 52, and the third through hole 53) may be provided at the same position in the circumferential direction of the inner cylinder 40, or may be disposed at different positions in the circumferential direction of the inner cylinder 40. s position.

In this embodiment, the flow ratio of the molten resin passing through the through hole (for example, the third through hole 53 ) on the second end portion 43 side is set to pass through the through hole (for example, the first through hole 53 ) on the first end portion 42 side. A plurality of through holes (the first through hole 51 , the second through hole 52 and the third through hole 53 ) are configured such that the flow rate of the molten resin in the through hole 51 is small. In the present embodiment, the total area of the inner tube 40 in the circumferential direction of the through hole (for example, the third through hole 53 ) located on the second end portion 43 side is larger than that of the through hole (for example, the third through hole 53 ) located on the first end portion 42 side. The total area in the circumferential direction of the inner cylinder 40 of the 1 through hole 51) is small. In this embodiment, the flow rate of the molten resin passing through the through hole (for example, the third through hole 53 ) on the second end portion 43 side is set to be higher than that of the molten resin passing through the through hole (for example, the third through hole 53 ) on the first end portion 42 side. A plurality of through holes (the first through hole 51, the second through hole 52, and the third through hole 53) are formed so that the flow velocity of the molten resin in the through hole 51) is slow. The flow resistance of the molten resin in the through hole on the second end 43 side (for example, the third through hole 53 ) is higher than that in the through hole in the first end 42 side (for example, the first through hole 51 ). A plurality of through-holes (the first through-hole 51 , the second through-hole 52 , and the third through-hole 53 ) are configured so that the flow resistance of the molten resin is large. Specifically, a plurality of through holes (the first through hole 51, the second through hole 52, and the third through hole 53) are formed so that the flow rate of the molten resin becomes smaller as the approach from the first end portion 42 to the second end portion 43 becomes smaller. ). The total area of the plurality of through-holes (first through-hole 51 , second through-hole 52 , and third through-hole 53 ) in the circumferential direction of the inner cylinder 40 becomes smaller as approaching from the first end 42 to the second end 43 . . A plurality of through-holes (first through-hole 51 , second through-hole 52 and third through-hole 53 ) are formed such that the flow velocity of molten resin becomes slower as approaching from first end 42 to second end 43 . A plurality of through-holes (first through-hole 51 , second through-hole 52 and third through-hole 53 ) are formed so that the flow resistance of the molten resin increases from the first end 42 to the second end 43 .

The first molten resin supplied to the injection nozzle 10 first is located at the second end 43 side of the molten resin storage part 46, and the second molten resin supplied to the injection nozzle 10 after the first molten resin is located at the side of the molten resin storage part 46. 1st end part 42 side. Therefore, in the present embodiment, in the injection nozzle 10, the flow rate of the first molten resin is relatively smaller than the flow rate of the second molten resin supplied to the injection nozzle 10 after the first molten resin. A plurality of through holes (the first through hole 51 , the second through hole 52 and the third through hole 53 ). In the present embodiment, the injection nozzle 10 is configured so that the flow velocity of the first molten resin is relatively slower than the flow velocity of the second molten resin supplied to the injection nozzle 10 after the first molten resin. A plurality of through holes (the first through hole 51 , the second through hole 52 and the third through hole 53 ). In the present embodiment, in the injection nozzle 10, a plurality of through-holes (the first molten resin) are formed so that the flow resistance of the first molten resin is greater than that of the second molten resin supplied to the injection nozzle 10 after the first molten resin. 1 through hole 51, second through hole 52, and third through hole 53). In addition, in this specification, the 1st molten resin and the 2nd molten resin are injected in the injection process of 1 molten resin.

The inner cylinder 40 may further include a fourth through-hole 54 that communicates the molten resin storage portion 46 and the second end portion 43 in order to suppress stagnation of the molten resin. In one resin injection process, in order to sufficiently knead the first molten resin and the second molten resin supplied to the injection nozzle 10 after the first molten resin, it is preferable to flow into the inner peripheral surface 44 of the inner cylinder 40 . A large amount of molten resin in the inner space passes not through the fourth through hole 54 but through the first through hole 51 , the second through hole 52 , and the third through hole 53 , and is injected from the injection nozzle 10 . Therefore, the fourth through hole 54 is preferably smaller than the first through hole 51 , the second through hole 52 , and the third through hole 53 .

The inner cylinder 40 includes a plurality of protrusions (first protrusions 55 , second protrusions 56 and third protrusions 57 ) on the outer peripheral surface 45 of the inner cylinder 40 . Specifically, a first protrusion 55 , a second protrusion 56 , and a third protrusion 57 are provided on the outer peripheral surface 45 of the main body portion 41 of the inner cylinder 40 . A plurality of protrusions (first protrusion 55 , second protrusion 56 , and third protrusion 57 ) are located in the space between the outer peripheral surface 45 of the inner cylinder 40 and the inner peripheral surface 24 of the outer cylinder 20 . A plurality of protrusions (the first protrusion 55 , the second protrusion 56 , and the third protrusion 57 ) may be in contact with the inner peripheral surface 24 of the outer cylinder 20 . The second protrusion 56 is located on the second end portion 43 side (downstream side of the molten resin, nozzle head 30 side) compared to the first protrusion 55 , and the third protrusion 57 is located on the second end portion 43 side (downstream side) from the second protrusion 56 . the downstream side of the molten resin, the nozzle head 30 side). In this embodiment, the first protrusion 55, the second protrusion 56, and the third protrusion 57 have the same size and shape. The first protrusion 55, the second protrusion 56, and the third protrusion 57 may have different sizes or shapes from each other. One or more first protrusions 55 , second protrusions 56 , and third protrusions 57 are respectively provided in the circumferential direction of the inner cylinder 40 . In this embodiment, the same number of first protrusions 55 , second protrusions 56 , and third protrusions 57 are provided in the circumferential direction of the inner cylinder 40 .

The molten resin passes through the first through hole 51 , the second through hole 52 and the third through hole 53 , and flows from the molten resin storage portion 46 of the inner cylinder 40 between the outer peripheral surface 45 of the inner cylinder 40 and the inner peripheral surface 24 of the outer cylinder 20 . Space. In order to fully knead the molten resin through the first protrusion 55, the second protrusion 56, and the third protrusion 57, a plurality of protrusions (the first protrusion 55, the second protrusion 56, and the third protrusion 57) can be arranged in multiple positions. Each of the through holes (the first through hole 51 , the second through hole 52 and the third through hole 53 ) is on the second end 43 side (the downstream side of the molten resin, the nozzle head 30 side). Specifically, the first protrusion 55 may be arranged on the second end portion 43 side of the first through hole 51 (the downstream side of the molten resin, the nozzle head 30 side). The second protrusion 56 can be arranged on the second end portion 43 side of the second through hole 52 (the downstream side of the molten resin, the nozzle head 30 side). The third protrusion 57 can be arranged on the second end portion 43 side of the third through hole 53 (the downstream side of the molten resin, the nozzle head 30 side). The first protrusion 55 may be arranged on the first end portion 42 side (the upstream side of the molten resin, the rear end side of the nozzle) with respect to the second through hole 52 . The second protrusion 56 may be arranged on the first end portion 42 side (the upstream side of the molten resin, the rear end side of the nozzle) with respect to the third through hole 53 .

The molten resin passes through the first through hole 51 , the second through hole 52 and the third through hole 53 , and flows from the molten resin storage portion 46 of the inner cylinder 40 between the outer peripheral surface 45 of the inner cylinder 40 and the inner peripheral surface 24 of the outer cylinder 20 . Space. In order to fully knead the molten resin, a plurality of protrusions (first protrusions 55, second protrusions 56, and third protrusions 57) adjacent to each other in the direction in which the inner cylinder 40 extends may be formed by extending the inner cylinder 40. The directions are configured in such a way that they do not overlap each other. Each of the plurality of protrusions (the first protrusion 55, the second protrusion 56, and the third protrusion 57) and the plurality of through holes (the first through hole 51, the second through hole 52, and the third through hole 53) can each be connected to the inner cylinder 40. The circumferential direction of the inner cylinder 40 may be set at the same position, and the circumferential direction of the inner cylinder 40 may also be set at different positions. In the present embodiment, each of the plurality of protrusions (first protrusion 55, second protrusion 56, and third protrusion 57) is connected to a plurality of through holes (first through hole 51, second through hole) in the direction in which the inner cylinder 40 extends. The holes 52 and the third through holes 53) are provided so as to partially overlap each other. Specifically, the first protrusion 55 is provided so as to partially overlap the first through hole 51 in the direction in which the inner cylinder 40 extends. The second protrusion 56 is provided so as to partially overlap the second through hole 52 in the direction in which the inner cylinder 40 extends. The third protrusion 57 is provided so as to partially overlap the third through hole 53 in the direction in which the inner cylinder 40 extends.

The mold clamping device 80 mainly includes a fixed platen 81 , a movable platen 82 , a connecting rod 83 connecting the fixed platen 81 and the movable platen 82 , and a second drive unit 84 for moving the movable platen 82 . The fixed mold 71 is attached to the fixed platen 81 . The movable mold 72 is attached to the movable platen 82 . The mold 70 includes a fixed mold 71 and a movable mold 72 .

An injection method using the injection device 2 and an injection molding method using the injection molding device 1 in this embodiment will be described with reference to FIGS. 1 to 4B .

Referring to FIGS. 1 to 4A , the injection molding method using the injection molding apparatus 1 of this embodiment may include the following steps. The mold 70 is closed by the mold clamping device 80 (S10). Specifically, the movable platen 82 is moved toward the fixed platen 81 by the second drive unit 84 . The movable mold 72 is pressed against the fixed mold 71 to close the mold 70 and form a mold cavity between the fixed mold 71 and the movable mold 72 . Next, the kneaded first molten resin and second molten resin are injected into the mold 70 using the injection method of the present embodiment shown in FIG. 4B ( S20 ). The cavity between the fixed mold 71 and the movable mold 72 is filled with the first molten resin and the second molten resin. Then, the first molten resin and the second molten resin injected into the mold 70 are cooled to obtain a solidified molded article (S40). The mold 70 is opened, and the cured molded article is taken out from the mold 70 (S50). Specifically, the movable platen 82 is moved by the second driving unit 84 so as to be separated from the fixed platen 81 , the mold 70 is opened, and the cured molded product is taken out from the mold 70 . The injection molding method of this embodiment can be applied to the injection molding method of the recycled resin composition, for example.

Referring to FIG. 1 to FIG. 3 and FIG. 4B , the injection method using the injection device 2 of this embodiment may include the following steps. The resin is melted (S21). Resin materials such as resin pellets for regeneration are supplied from the hopper 3 to the hollow portion 4 c of the cylinder 4 . The screw 6 is rotated by the first drive unit 7 . Resin materials such as resin pellets for regeneration are heated and plasticized by heat from the first heater 5 , frictional heat accompanying the rotation of the screw 6 , and the like. As a result, the resin material becomes molten resin. The molten resin is sent to the end 4 b of the cylinder 4 on the side of the injection nozzle 10 by the rotation of the screw 6 . When the molten resin accumulates on the end 4b side of the injection nozzle 10 side of the cylinder 4, the pressure of the molten resin causes the screw 6 to retreat toward the first drive unit 7 to measure the molten resin. When the screw 6 retreats toward the first driving unit 7 , the first driving unit 7 stops the rotation of the screw 6 .

Next, the first molten resin that is a part of the molten resin is supplied to the injection nozzle 10 (S22). After the first molten resin is supplied to the injection nozzle 10, the second molten resin which is a part of the melted resin is supplied to the injection nozzle 10 (S23). Specifically, the first driving unit 7 advances the screw 6 toward the injection nozzle 10 side. The molten resin is filled into the molten resin reservoir 46 of the inner cylinder 40 . The first molten resin is filled into the second end portion 43 side of the molten resin reservoir 46 of the inner cylinder 40 (the downstream side of the molten resin, the nozzle head 30 side), and the first molten resin is supplied to the injection nozzle 10 after the first molten resin. 2. The molten resin is filled into the first end portion 42 side of the molten resin reservoir 46 of the inner cylinder 40 (the upstream side of the molten resin, the rear end side of the nozzle). The supply of the first molten resin to the injection nozzle 10 and the supply of the second molten resin to the injection nozzle 10 are performed in one injection step of the molten resin.

In the injection nozzle 10, the flow rate of the first molten resin is made relatively smaller than the flow rate of the second molten resin (S24). In the injection nozzle 10, the flow velocity of the first molten resin is made relatively slower than the flow velocity of the second molten resin. Specifically, the molten resin flows from the molten resin reservoir 46 of the inner cylinder 40 through the first through hole 51, the second through hole 52, and the third through hole 53, and flows into the outer peripheral surface 45 of the inner cylinder 40 and the inner periphery of the outer cylinder 20. The space enclosed by face 24. For example, since the size of the third through hole 53 is smaller than that of the first through hole 51 , the flow resistance of the molten resin in the third through hole 53 is greater than that in the first through hole 51 . The flow rate of the first molten resin flowing through the third through hole 53 having relatively large flow resistance becomes smaller than the flow rate of the second molten resin flowing through the first through hole 51 having relatively small flow resistance. The flow velocity of the first molten resin flowing through the third through hole 53 having relatively large flow resistance becomes slower than the flow velocity of the second molten resin flowing through the first through hole 51 having relatively small flow resistance. As a result, in the space surrounded by the outer peripheral surface 45 of the inner cylinder 40 and the inner peripheral surface 24 of the outer cylinder 20, the first molten resin and the first molten resin of the molten resin reservoir 46 injected into the inner cylinder 40 after the first molten resin 2 The molten resin is thoroughly mixed.

Next, in the injection nozzle 10, the first molten resin whose flow rate is relatively smaller than that of the second molten resin is kneaded with the second molten resin (S25). In the injection nozzle 10, the first molten resin and the second molten resin whose flow rate is relatively slower than that of the second molten resin are kneaded. When the first molten resin and the second molten resin mixed with each other flow toward the second end portion 43 of the inner cylinder 40 in the space surrounded by the outer peripheral surface 45 of the inner cylinder 40 and the inner peripheral surface 24 of the outer cylinder 20, the first molten resin mixed with each other flows to the second end 43 of the inner cylinder 40. The first molten resin and the second molten resin are branched by a plurality of protrusions (the first protrusion 55, the second protrusion 56, and the third protrusion 57) and merged. In this way, in one resin injection step, the first molten resin and the first molten resin can be supplied to the injection nozzle through the plurality of protrusions (the first protrusion 55, the second protrusion 56, and the third protrusion 57). The second molten resin of 10 is fully kneaded.

The kneaded first molten resin and second molten resin are injected from the injection nozzle 10 (S26). Specifically, the first molten resin and the second molten resin kneaded by the plurality of protrusions (the first protrusion 55 , the second protrusion 56 and the third protrusion 57 ) pass through the penetration portion 49 and are drawn from the outer peripheral surface 45 of the inner tube 40 The space surrounded by the inner peripheral surface 24 of the outer cylinder 20 flows to the nozzle head 30 . The kneaded first molten resin and second molten resin are injected from the nozzle head 30 into the cavity of the mold 70 .

In this embodiment, the flow ratio of the first molten resin passing through the through-hole (for example, the third through-hole 53 ) on the second end portion 43 side passes through the through-hole (for example, third through-hole 53 ) on the first end portion 42 side. The injection nozzle 10, the injection device 2, and the injection molding device 1 are configured such that the flow rate of the second molten resin in the first through hole 51) is small. In the present embodiment, the injection nozzle 10 , the injection device 2 , and the injection molding device 1 are configured such that the flow velocity of a part of the first molten resin is slower than that of a part of the second molten resin. In a modified example of the present embodiment, the injection nozzle 10 , the injection device 2 , and the injection molding device 1 may be configured such that the flow rate of the second molten resin is greater than the flow rate of the first molten resin. In a modified example of the present embodiment, the injection nozzle 10, the injection device 2, and the injection molding device 1 may be configured such that the flow velocity of a part of the second molten resin becomes faster than the flow velocity of a part of the first molten resin. . In the injection method and the injection molding method of this embodiment, the flow rate of the first molten resin is made smaller than the flow rate of the second molten resin. In the injection method and the injection molding method of this embodiment, the flow velocity of a part of the first molten resin is made slower than the flow velocity of a part of the second molten resin. In the injection method and the injection molding method according to the modified example of this embodiment, the flow rate of the second molten resin may be made larger than the flow rate of the first molten resin. In the injection method and the injection molding method according to the modified example of this embodiment, the flow velocity of a part of the second molten resin may be made faster than the flow velocity of a part of the first molten resin.

Operations and effects of this embodiment will be described.

The injection nozzle 10 of the present embodiment includes an outer cylinder 20 having a nozzle head 30 and an inner cylinder 40 disposed inside the outer cylinder 20 . The inner cylinder 40 includes: a molten resin storage portion 46 for storing molten resin, an outer peripheral surface 45, and a plurality of through holes (first through hole 51, second through hole 52, third through hole) connecting the molten resin storage portion 46 and the outer peripheral surface 45. through hole 53), a plurality of protrusions (first protrusion 55, second protrusion 56, third protrusion 57) provided on the outer peripheral surface 45, the first end 42 where the molten resin flows, and the first end 42 Compared with the second end portion 43 located on the nozzle head 30 side. The flow ratio of the molten resin passing through the through hole (for example, the third through hole 53 ) on the side of the second end portion 43 is such that the flow ratio of the molten resin passing through the through hole (for example, the first through hole 51 ) on the side of the first end portion 42 is controlled. A plurality of through-holes (first through-hole 51 , second through-hole 52 , and third through-hole 53 ) are formed so that the flow rate of the resin is small.

The injection nozzle 10 of the present embodiment includes an outer cylinder 20 having a nozzle head 30 and an inner cylinder 40 disposed inside the outer cylinder 20 . The inner cylinder 40 includes: a molten resin storage portion 46 for storing molten resin, an outer peripheral surface 45, and a plurality of through holes (first through hole 51, second through hole 52, third through hole) connecting the molten resin storage portion 46 and the outer peripheral surface 45. through hole 53), a plurality of protrusions (first protrusion 55, second protrusion 56, third protrusion 57) provided on the outer peripheral surface 45, the first end 42 where the molten resin flows, and the first end 42 Compared with the second end portion 43 located on the nozzle head 30 side. The total area of the inner cylinder 40 in the circumferential direction of the through hole (for example, the third through hole 53 ) located on the second end portion 43 side is larger than that of the through hole (for example, the first through hole 51 ) located on the first end portion 42 side. The total area in the circumferential direction of the inner cylinder 40 is small.

The injection nozzle 10 of this embodiment is configured such that the flow rate of the first molten resin in the injection nozzle 10 is relatively smaller than the flow rate of the second molten resin supplied to the injection nozzle 10 after the first molten resin. The injection nozzle 10 of this embodiment is configured such that the flow velocity of the first molten resin in the injection nozzle 10 is relatively slower than the flow velocity of the second molten resin supplied to the injection nozzle 10 after the first molten resin. The injection nozzle 10 of the present embodiment is configured such that the first molten resin in the injection nozzle 10 receives greater flow resistance than the second molten resin supplied to the injection nozzle 10 after the first molten resin.

According to the injection nozzle 10 of the present embodiment, in the injection nozzle 10 , the flow rate of the first molten resin is relatively smaller than the flow rate of the second molten resin supplied to the injection nozzle 10 after the first molten resin. According to the injection nozzle 10 of the present embodiment, the flow velocity of the first molten resin in the injection nozzle 10 becomes relatively slower than the flow velocity of the second molten resin supplied to the injection nozzle 10 after the first molten resin. Therefore, in one resin injection process, after the first molten resin is sufficiently mixed with the second molten resin supplied to the injection nozzle 10 after the first molten resin, the resin passes through a plurality of protrusions (first protrusions 55, The second protrusions 56 and the third protrusions 57 ) can sufficiently knead the first molten resin and the second molten resin supplied to the injection nozzle 10 after the first molten resin. Such sufficiently kneaded first molten resin and second molten resin can be mixed. As a result, according to the injection nozzle 10 of the present embodiment, color unevenness of molded products can be sufficiently suppressed.

In the injection nozzle 10 of this embodiment, a plurality of through-holes (first through-hole 51, second through-hole 51, hole 52, the third through hole 53). In the injection nozzle 10 of this embodiment, the total area of the plurality of through-holes (first through-hole 51, second through-hole 52, and third through-hole 53) in the circumferential direction of the inner tube 40 can be increased from the first end to the first end. The portion 42 becomes smaller as it approaches the second end portion 43 . Specifically, the dimensions of the plurality of through holes (the first through hole 51 , the second through hole 52 , and the third through hole 53 ) may become smaller as approaching the second end portion 43 from the first end portion 42 . The injection nozzle 10 of the present embodiment is configured such that the flow rate of the molten resin becomes smaller as it approaches the second end portion 43 from the first end portion 42 . The injection nozzle 10 of the present embodiment is configured such that the flow velocity of the molten resin becomes slower as it approaches the second end portion 43 from the first end portion 42 . The injection nozzle 10 of the present embodiment is configured such that the flow resistance of the molten resin gradually increases from the first end portion 42 to the second end portion 43 . Therefore, according to the injection nozzle 10 of the present embodiment, the first molten resin and the second molten resin supplied to the injection nozzle 10 after the first molten resin can be further sufficiently kneaded in one resin injection step. . The sufficiently kneaded first molten resin and second molten resin can be injected from the injection nozzle 10 . As a result, according to the injection nozzle 10 of the present embodiment, color unevenness of molded products can be further suppressed.

The injection device 2 of the present embodiment includes the injection nozzle as described above. According to the injection device 2 of the present embodiment, the first molten resin and the second molten resin supplied to the injection nozzle 10 after the first molten resin can be sufficiently kneaded in one resin injection step. The sufficiently kneaded first molten resin and second molten resin can be injected from the injection device 2 . As a result, according to the injection device 2 of the present embodiment, color unevenness of molded products can be sufficiently suppressed.

The injection molding apparatus 1 of the present embodiment includes the above-mentioned injection apparatus 2 and mold clamping apparatus 80 . According to the injection molding apparatus 1 of the present embodiment, the first molten resin and the second molten resin supplied to the injection nozzle 10 after the first molten resin can be sufficiently kneaded in one resin injection step. The sufficiently kneaded first molten resin and second molten resin can be injected from the injection device 2 . As a result, according to the injection molding apparatus 1 of the present embodiment, color unevenness of molded products can be sufficiently suppressed.

The injection method of this embodiment includes: melting the resin; supplying the first molten resin as a part of the melted resin to the injection nozzle 10; supplying the second molten resin as a part of the melted resin after the first molten resin supplied to the injection nozzle 10; in the injection nozzle 10, the flow rate of the first molten resin is relatively small compared with the flow rate of the second molten resin supplied to the injection nozzle 10 after the first molten resin; in the injection nozzle 10, The first molten resin whose flow rate is relatively smaller than that of the second molten resin is kneaded with the second molten resin; the kneaded first molten resin and the second molten resin are injected from the injection nozzle 10 . The injection method of this embodiment includes: melting the resin; supplying the first molten resin as a part of the melted resin to the injection nozzle 10; supplying the second molten resin as a part of the melted resin after the first molten resin supplied to the injection nozzle 10; in the injection nozzle 10, the flow velocity of the first molten resin becomes relatively slow compared with the flow velocity of the second molten resin supplied to the injection nozzle 10 after the first molten resin; In the injection nozzle 10, the first molten resin whose flow rate is relatively slow compared with the second molten resin is kneaded with the second molten resin; the kneaded first molten resin and the second molten resin are injected from the injection nozzle 10 resin. According to the injection method of the present embodiment, after the first molten resin is sufficiently mixed with the second molten resin supplied to the injection nozzle 10 after the first molten resin, the mixed first molten resin and second molten resin are mixed together. Resin mixing. Therefore, in one resin injection step, the first molten resin and the second molten resin supplied to the injection nozzle 10 after the first molten resin can be sufficiently kneaded. As a result, according to the injection method of the present embodiment, color unevenness of molded articles can be sufficiently suppressed.

In the injection method of the present embodiment, the injection nozzle 10 includes an outer cylinder 20 having a nozzle head 30 and an inner cylinder 40 arranged inside the outer cylinder 20 . The inner cylinder 40 includes: a molten resin storage portion 46 for storing molten resin, an outer peripheral surface 45, and a plurality of through holes (first through holes 51, second through holes 52, third through-hole 53), a plurality of protrusions (first protrusion 55, second protrusion 56, and third protrusion 57) provided on the outer peripheral surface 45, the first end 42 into which molten resin flows, and the The 1st end part 42 is located rather than the 2nd end part 43 of the nozzle head 30 side. The inner cylinder 40 extends between the first end 42 and the second end 43 . The total area of the inner cylinder 40 in the circumferential direction of the through hole (for example, the third through hole 53 ) located on the second end portion 43 side is larger than that of the through hole (for example, the first through hole 51 ) located on the first end portion 42 side. The total area in the circumferential direction of the inner cylinder 40 is small. According to the injection method of the present embodiment, the first molten resin and the second molten resin supplied to the injection nozzle 10 after the first molten resin can be sufficiently kneaded in one resin injection step. As a result, according to the injection method of the present embodiment, color unevenness of molded articles can be sufficiently suppressed.

The injection molding method of this embodiment includes: injecting the kneaded first molten resin and the second molten resin into the mold 70 by the above-mentioned injection method; cooling the first molten resin and the second molten resin injected into the mold 70; , to obtain a cured molded product. According to the injection molding method of the present embodiment, the first molten resin and the second molten resin supplied to the injection nozzle 10 after the first molten resin can be sufficiently kneaded in one resin injection step. Thus sufficiently kneaded first molten resin and second molten resin can be injected. As a result, according to the injection molding method of the present embodiment, color unevenness of molded articles can be sufficiently suppressed.

(Embodiment 2)

The inner cylinder 40a of the injection nozzle according to Embodiment 2 will be described with reference to FIG. 5 . In this embodiment, the structure of the injection nozzle and the injection molding apparatus, the injection method, and the injection molding method that do not include the inner cylinder 40 a are the same as the structure of the injection nozzle 10 and the injection molding apparatus 1 of Embodiment 1, and the injection method and injection molding The method is the same. The inner cylinder 40a of the injection nozzle of this embodiment basically has the same configuration as the inner cylinder 40 of the injection nozzle 10 in Embodiment 1 shown in FIGS. different.

In the present embodiment, the inner cylinder 40a includes a plurality of through holes (first through hole 51a, second through hole 52a, and third through hole 53a) communicating the molten resin reservoir 46 and the outer peripheral surface 45 . Specifically, the main body portion 41 of the inner cylinder 40a is provided with a first through hole 51a, a second through hole 52a, and a third through hole 53a. The second through hole 52a is located on the second end portion 43 side (downstream side of the molten resin, nozzle head 30 side) compared to the first through hole 51a, and the third through hole 53a is located on the second end side compared to the second through hole 52a. part 43 side (downstream side of molten resin, nozzle head 30 side). In this embodiment, the 1st through-hole 51a, the 2nd through-hole 52a, and the 3rd through-hole 53a have the same size. In this embodiment, the number of through-holes (for example, third through-holes 53 a ) located on the second end portion 43 side is greater than the number of through-holes (for example, first through-holes 51 a ) located on the first end portion 42 side. few. More specifically, the number of through-holes (first through-hole 51 a , second through-hole 52 a , and third through-hole 53 a ) decreases as approaching from first end 42 to second end 43 . The number of second through holes 52a in the circumferential direction of the inner cylinder 40a is smaller than the number of first through holes 51a in the circumferential direction of the inner cylinder 40a. The number of objects of the 3rd through-hole 53a of the circumferential direction of the inner cylinder 40a is smaller than the number of objects of the 2nd through-hole 52a of the circumferential direction of the inner cylinder 40a. The number of objects of the third through-holes 53a in the circumferential direction of the inner cylinder 40a is smaller than the number of objects of the first through-holes 51a in the circumferential direction of the inner cylinder 40a.

In this embodiment, the flow ratio of the molten resin passing through the through hole (for example, the third through hole 53 a ) on the second end portion 43 side is set to pass through the through hole (for example, the first through hole 53 a ) on the first end portion 42 side. A plurality of through holes (the first through hole 51a, the second through hole 52a, and the third through hole 53a) are configured such that the flow rate of the molten resin in the through hole 51a) is small. In the present embodiment, the total area of the inner tube 40a in the circumferential direction of the through hole (for example, the third through hole 53a ) located on the second end portion 43 side is larger than that of the through hole (for example, the third through hole 53a ) located on the first end portion 42 side. The total area in the circumferential direction of the inner cylinder 40a of the 1 through hole 51a) is small. In the present embodiment, the flow rate of the molten resin passing through the through hole (for example, the third through hole 53a) on the second end portion 43 side is set to be higher than that of the molten resin passing through the through hole (for example, the third through hole 53a) on the first end portion 42 side. A plurality of through holes (the first through hole 51a, the second through hole 52a, and the third through hole 53a) are formed such that the flow velocity of the molten resin in the through hole 51a) is slow. The flow resistance of the molten resin in the through hole (for example, the third through hole 53a) located on the second end portion 43 side becomes lower than that in the through hole located on the first end portion 42 side (for example, the first through hole 51a). A plurality of through-holes (first through-hole 51a, second through-hole 52a, and third through-hole 53a) are formed so that the flow resistance of the molten resin in the resin is large.

In this embodiment, a plurality of through holes (first through hole 51a, second through hole 52a, and third through hole 53a). In this embodiment, the total area of the plurality of through holes (the first through hole 51a, the second through hole 52a, and the third through hole 53a) in the circumferential direction of the inner cylinder 40a increases from the first end 42 to the second end. The end 43 becomes smaller. In this embodiment, a plurality of through-holes (first through-hole 51a, second through-hole 52a, and second 3 through hole 53a). In this embodiment, a plurality of through holes (first through hole 51a, second through hole 52a, and second 3 through hole 53a).

The first molten resin supplied to the injection nozzle first is located on the second end portion 43 side of the molten resin storage part 46, and the second molten resin supplied to the injection nozzle after the first molten resin is located on the first side of the molten resin storage part 46. end 42 side. Therefore, in this embodiment, the flow rate of the first molten resin in the injection nozzle is relatively smaller than the flow rate of the second molten resin supplied to the injection nozzle after the first molten resin. holes (the first through hole 51a, the second through hole 52a, and the third through hole 53a). In the present embodiment, the plurality of through-holes are formed so that the flow velocity of the first molten resin in the injection nozzle is relatively slower than the flow velocity of the second molten resin supplied to the injection nozzle after the first molten resin. holes (the first through hole 51a, the second through hole 52a, and the third through hole 53a). In the present embodiment, the plurality of through-holes are formed so that the first molten resin in the injection nozzle receives a flow resistance greater than that of the second molten resin supplied to the injection nozzle of the present embodiment after the first molten resin (the first molten resin). 1 through hole 51a, the second through hole 52a, and the third through hole 53a).

Operations and effects of this embodiment will be described.

In the injection nozzle including the inner cylinder 40a of the present embodiment, the number of through-holes (for example, third through-holes 53a ) positioned on the second end portion 43 side is greater than the number of through-holes (for example, third through-holes 53a ) positioned on the first end portion 42 side. The number of objects of the 1st through-hole 51a) is small. The total area of the inner cylinder 40a in the circumferential direction of the through hole (for example, the third through hole 53a) located on the second end portion 43 side is larger than that of the through hole located on the first end portion 42 side (for example, the first through hole 51a). The total area in the circumferential direction of the inner cylinder 40a is small. Therefore, in the injection nozzle, the flow rate of the first molten resin is relatively smaller than the flow rate of the second molten resin supplied to the injection nozzle after the first molten resin. In the injection nozzle, the flow velocity of the first molten resin becomes relatively slower than the flow velocity of the second molten resin supplied to the injection nozzle after the first molten resin. In the injection nozzle, the first molten resin receives greater flow resistance than the second molten resin supplied to the injection nozzle after the first molten resin. Therefore, in the resin injection step once, after the first molten resin is sufficiently mixed with the second molten resin supplied to the injection nozzle after the first molten resin, the resin passes through a plurality of protrusions (the first protrusion 55, the second 2 protrusions 56 and 3rd protrusions 57) can sufficiently knead the first molten resin and the second molten resin supplied to the injection nozzle after the first molten resin. The sufficiently kneaded first molten resin and second molten resin can be injected from the injection nozzle. As a result, according to the injection nozzle provided with the inner cylinder 40a of this embodiment, the color unevenness of a molded product can fully be suppressed.

In the injection nozzle including the inner tube 40a of this embodiment, the number of the plurality of through holes (the first through hole 51a, the second through hole 52a, and the third through hole 53a) increases from the first end portion 42 to the third through hole. 2 ends 43 and become less. The injection nozzle including the inner cylinder 40 a of the present embodiment is configured such that the flow rate of the molten resin becomes smaller as it approaches the second end portion 43 from the first end portion 42 . The injection nozzle including the inner cylinder 40a of this embodiment is configured such that the flow velocity of the molten resin becomes slower as it approaches the second end portion 43 from the first end portion 42 . The injection nozzle including the inner cylinder 40 a of the present embodiment is configured such that the flow resistance of the molten resin increases from the first end portion 42 to the second end portion 43 . Therefore, according to the injection nozzle provided with the inner cylinder 40a of this embodiment, in one resin injection process, the first molten resin and the second molten resin supplied to the injection nozzle after the first molten resin can be more fully mixed. kneading. The sufficiently kneaded first molten resin and second molten resin can be injected from the injection nozzle. As a result, according to the injection nozzle provided with the inner cylinder 40a of this embodiment, the color unevenness of a molded product can be further suppressed.

(Embodiment 3)

An injection nozzle 10 b including an inner cylinder 40 b according to Embodiment 3 will be described with reference to FIG. 6 . The configuration, injection method, and injection molding method of the injection molding apparatus excluding the injection nozzle 10b in this embodiment are the same as the configuration, injection method, and injection molding method of the injection molding apparatus 1 in Embodiment 1. The injection nozzle 10 b of this embodiment basically has the same configuration as the injection nozzle 10 in Embodiment 1 shown in FIGS. 1 to 3 , and can obtain the same effect, but mainly differs in the following points.

The injection nozzle 10b in this embodiment is equipped with the outer cylinder 20 and the inner cylinder 40b. In the injection nozzle 10b in this embodiment, one of the openings (the first through hole 51b, the second through hole 52b, and the third through hole 53b) of the outer peripheral surface 45 of the inner tube 40b of at least one through hole (the first through hole 51b, the second through hole 52b, and the third through hole 53b) 1 opening 51h, 3rd opening 52h, 5th opening 53h) and at least 1 through-hole (first through-hole 51b, second through-hole 52b, third through-hole 53b) of the molten resin reservoir 46. The openings (the second opening 51i, the fourth opening 52i, and the sixth opening 53i) are located on the side of the first end portion 42 rather than the other. Specifically, the first opening 51h in the outer peripheral surface 45 of the inner cylinder 40b of the first through hole 51b is located on the first end 42 side than the second opening 51i in the molten resin reservoir 46 of the first through hole 51b. The third opening 52h in the outer peripheral surface 45 of the inner cylinder 40b of the second through hole 52b is located on the first end 42 side than the fourth opening 52i in the molten resin reservoir 46 of the second through hole 52b. The fifth opening 53h in the outer peripheral surface 45 of the inner cylinder 40b of the third through hole 53b is located on the first end portion 42 side than the sixth opening 53i in the molten resin storage portion 46 of the third through hole 53b.

This embodiment has the following actions and effects in addition to the actions and effects described in Embodiment 1.

In the injection nozzle 10b in this embodiment, one of the openings (the first through hole 51b, the second through hole 52b, and the third through hole 53b) of the outer peripheral surface 45 of the inner tube 40b of at least one through hole (the first through hole 51b, the second through hole 52b, and the third through hole 53b) 1 opening 51h, 3rd opening 52h, 5th opening 53h) and at least 1 through-hole (first through-hole 51b, second through-hole 52b, third through-hole 53b) of the molten resin reservoir 46. The openings (the second opening 51i, the fourth opening 52i, and the sixth opening 53i) are located on the side of the first end portion 42 rather than the other. The molten resin flows from the second end portion 43 side to the first end portion 42 side in at least one through hole (the first through hole 51b, the second through hole 52b, and the third through hole 53b). Part of it flows from the first end portion 42 side to the second end portion 43 side. Therefore, according to the injection nozzle 10b of the present embodiment, the first molten resin and the second molten resin supplied to the injection nozzle 10b after the first molten resin can be more fully mixed in one resin injection step. refining. The sufficiently kneaded first molten resin and second molten resin can be injected from the injection nozzle 10b. As a result, according to the injection nozzle 10b of the present embodiment, color unevenness of molded products can be further suppressed.

(Embodiment 4)

The inner cylinder 40c of the injection nozzle according to Embodiment 4 will be described with reference to FIG. 7 . In the present embodiment, the structure of the injection nozzle and the injection molding apparatus excluding the inner cylinder 40c, and the injection method and the injection molding method are the same as the structure of the injection nozzle 10 and the injection molding apparatus 1 of Embodiment 1, the injection method, and the injection molding The method is the same. The inner cylinder 40c of the injection nozzle of this embodiment basically has the same configuration as the inner cylinder 40 of the injection nozzle 10 in Embodiment 1 shown in FIGS. .

In the inner cylinder 40c of the injection nozzle of this embodiment, when viewed from the direction perpendicular to the direction in which the inner cylinder 40c extends (the normal direction of the outer peripheral surface 45 of the inner cylinder 40c), at least one protrusion (the first protrusion) 55c, 2nd protrusion 56c, and 3rd protrusion 57c) have the shape which has an opening in the 1st end part 42 side, and closed the 2nd end part 43 side. Specifically, the first protrusion 55c, the second protrusion 56c, and the third protrusion 57c may have a shape having an opening on the first end 42 side and a closed second end 43 side. As a shape which has an opening on the first end portion 42 side and is closed on the second end portion 43 side, a cup shape, an L-shape, etc. can be exemplified.

This embodiment has the following actions and effects in addition to the actions and effects described in Embodiment 1.

In the inner cylinder 40c of the injection nozzle according to this embodiment, at least one protrusion (the first protrusion 55c , the second protrusion 56c, and the third protrusion 57c) have an opening on the first end portion 42 side and a closed shape on the second end portion 43 side. By at least one protrusion (the first protrusion 55c, the second protrusion 56c, the third protrusion 57c) having such a shape, the molten metal that flows into the space surrounded by the outer peripheral surface 45 of the inner cylinder 40c and the inner peripheral surface 24 of the outer cylinder 20 Resin flow is reduced. By at least one protrusion (the first protrusion 55c, the second protrusion 56c, the third protrusion 57c) having such a shape, the molten metal that flows into the space surrounded by the outer peripheral surface 45 of the inner cylinder 40c and the inner peripheral surface 24 of the outer cylinder 20 The flow rate of the resin is reduced. Therefore, according to the injection nozzle provided with the inner cylinder 40c of this embodiment, in one resin injection step, the first molten resin and the second molten resin supplied to the injection nozzle after the first molten resin can be further sufficiently injected. Resin mixing. The sufficiently kneaded first molten resin and second molten resin can be injected from the injection nozzle 10 . As a result, according to the injection nozzle provided with the inner cylinder 40c of this embodiment, the color unevenness of a molded product can be further suppressed.

(Embodiment 5)

An inner cylinder 40d of an injection nozzle according to Embodiment 5 will be described with reference to FIG. 8A . In this embodiment, the structure of the injection nozzle and the injection molding apparatus, the injection method, and the injection molding method that do not include the inner cylinder 40d are the same as the structure of the injection nozzle 10 and the injection molding apparatus 1 of Embodiment 1, and the injection method and injection molding The method is the same. The inner cylinder 40d of the injection nozzle of this embodiment basically has the same configuration as the inner cylinder 40 of the injection nozzle 10 in Embodiment 1 shown in FIGS. 1 to 3, and can obtain the same effects, mainly in the following points different.

Referring to FIGS. 8A and 8B , in the inner cylinder 40d of the injection nozzle according to this embodiment, at least one protrusion (first protrusion 55d, second protrusion 56d, The third protrusion 57d) has a third end portion 61a on the first end portion 42 side, a fourth end portion 61b on the second end portion 43 side, and a central portion between the third end portion 61a and the fourth end portion 61b. 61c, the third end portion 61a and the fourth end portion 61b have a narrower width than the central portion 61c. Specifically, the first protrusion 55c, the second protrusion 56c, and the third protrusion 57c have a third end portion 61a on the first end portion 42 side, a fourth end portion 61b on the second end portion 43 side, and a third end portion 61b on the third end portion 43 side. There is a central portion 61c between the portion 61a and the fourth end portion 61b, and the third end portion 61a and the fourth end portion 61b have a narrower width than the central portion 61c. At least one protrusion (first protrusion 55d, second protrusion 56d, third protrusion 57d) can be Have the shape of an ellipse, a rhombus, or the like.

This embodiment has the following actions and effects in addition to the actions and effects described in Embodiment 1.

When viewed from a direction intersecting the direction in which the inner cylinder 40d extends (the normal direction of the outer peripheral surface 45 of the inner cylinder 40d), at least one protrusion (the first protrusion 55d, the second protrusion 56d, and the third protrusion 57d) There is a third end 61a on the side of the first end 42, a fourth end 61b on the side of the second end 43, a central portion 61c between the third end 61a and the fourth end 61b, and the third end 61a And the 4th end part 61b has width narrower than the center part 61c. Therefore, at least one protrusion (first protrusion 55d, second protrusion 56d, third protrusion 57d) in this embodiment is different from the plurality of protrusions (first protrusion 55, second protrusion 56, second protrusion 57d) in Embodiment 1. 3 protrusions 57) have lower flow resistance for molten resin. In the space surrounded by the outer peripheral surface 45 of the inner cylinder 40 and the inner peripheral surface 24 of the outer cylinder 20, at least one protrusion (the first protrusion 55d, the second protrusion 56d, and the third protrusion 57d) of this embodiment , the pressure of the molten resin can be suppressed from rising. As a result, deterioration of the molten resin and damage to the outer cylinder 20 and the inner cylinder 40 can be suppressed.

(Example)

Examples of the above-mentioned embodiment will be described while comparing with comparative examples. In the following examples and comparative examples, as the resin pellets for regeneration stored in the hopper 3, white resin pellets and black resin pellets of polypropylene resin (manufactured by Japan Polypro Co., Ltd.) at a ratio of 1:1 were used. Resin pellets mixed in weight ratio. The resin pellets were injection-molded using a general-purpose injection molding apparatus (manufactured by Nissei Plastic Industry Co., Ltd.), thereby obtaining a flat plate-shaped test piece having a length of 100 mm, a width of 100 mm, and a thickness of 2 mm. The color unevenness of the test piece was evaluated by visually inspecting the test piece.

(Example 1)

The inner cylinder 40 of the first embodiment is an example of the inner cylinder 40 of the first embodiment. The inner cylinder 40 of Example 1 has a total length of 44 mm and an inner diameter of 10 mm. The entire length of the inner cylinder 40 is the length between the first end 42 and the second end 43 . The inner diameter of the inner cylinder 40 is the inner diameter of the inner peripheral surface 44 of the inner cylinder 40 . The third through hole 53 located on the side closest to the second end portion 43 (the downstream side of the molten resin, the nozzle head 30 side) has a diameter of 2 mm. The second through hole 52 located on the side of the first end portion 42 relative to the third through hole 53 has a diameter of 3 mm. The first through hole 51 located on the side closest to the first end portion 42 (the upstream side of the molten resin, the rear end side of the nozzle) has a diameter of 4 mm. Four first through-holes 51 , second through-holes 52 , and third through-holes 53 are arranged at equal intervals along the circumferential direction of the inner cylinder 40 .

Each of the first protrusion 55 , the second protrusion 56 and the third protrusion 57 on the outer peripheral surface 45 of the inner cylinder 40 has a height of 2 mm and a width of 2 mm. Eight first protrusions 55 , second protrusions 56 , and third protrusions 57 are arranged at equal intervals along the circumferential direction of the inner tube 40 . The total length in the circumferential direction of the inner cylinder 40 of each of the first protrusion 55 , the second protrusion 56 , and the third protrusion 57 is half the length of the outer circumference of the inner cylinder 40 . The first protrusion 55 is arranged on the second end portion 43 side (the downstream side of the molten resin, the nozzle head 30 side) with respect to the first through hole 51 , and is arranged at the first end portion 42 side (the molten resin side) with respect to the second through hole 52 . Resin upstream side, nozzle rear end side). The second protrusion 56 is arranged on the second end portion 43 side (downstream side of the molten resin, nozzle head 30 side) with respect to the second through hole 52 , and is arranged at the first end portion 42 side with respect to the third through hole 53 ( the upstream side of the molten resin, the rear end side of the nozzle). The third protrusion 57 is arranged on the second end portion 43 side (the downstream side of the molten resin, the nozzle head 30 side) with respect to the third through hole 53 . By using the injection molding apparatus provided with the inner cylinder 40 of this Example, the test piece which does not have color unevenness was obtained.

(Example 2)

The inner cylinder 40a of the second embodiment is an example of the inner cylinder 40a of the second embodiment. The inner cylinder 40a of Example 2 has a total length of 44 mm and an inner diameter of 10 mm. The entire length of the inner cylinder 40 a is the length between the first end 42 and the second end 43 . The inner diameter of the inner cylinder 40a is the inner diameter of the inner peripheral surface 44 of the inner cylinder 40a. The first through hole 51a, the second through hole 52a, and the third through hole 53a have a diameter of 3 mm. Four first through-holes 51 a located closest to the first end portion 42 (the upstream side of the molten resin, the rear end side of the nozzle) are arranged at equal intervals along the circumferential direction of the inner cylinder 40 a. Three second through holes 52a located on the second end portion 43 side (downstream side of molten resin, nozzle head 30 side) than the first through holes 51a are arranged at equal intervals along the circumferential direction of the inner cylinder 40a. Two third through-holes 53a located closest to the second end portion 43 (downstream side of the molten resin, nozzle head 30 side) are arranged at equal intervals along the circumferential direction of the inner cylinder 40a.

Each of the first protrusion 55, the second protrusion 56, and the third protrusion 57 on the outer peripheral surface 45 of the inner cylinder 40a has a height of 2 mm and a width of 2 mm. Eight first protrusions 55, second protrusions 56, and third protrusions 57 are arranged at equal intervals along the circumferential direction of the inner cylinder 40a. The total length in the circumferential direction of the inner cylinder 40a of each of the first protrusion 55, the second protrusion 56, and the third protrusion 57 is half the length of the outer circumference of the inner cylinder 40a. The first protrusion 55 is arranged on the second end portion 43 side (the downstream side of the molten resin, the nozzle head 30 side) with respect to the first through hole 51 a, and is arranged on the first end portion 42 side with respect to the second through hole 52 a ( the upstream side of the molten resin, the rear end side of the nozzle). The second protrusion 56 is arranged on the second end portion 43 side (the downstream side of the molten resin, the nozzle head 30 side) with respect to the second through hole 52a, and is arranged on the first end portion 42 side with respect to the third through hole 53a ( the upstream side of the molten resin, the rear end side of the nozzle). The third protrusion 57 is arranged on the second end portion 43 side (the downstream side of the molten resin, the nozzle head 30 side) with respect to the third through hole 53 a. By using the injection molding apparatus provided with the inner cylinder 40a of this Example, the test piece which does not have color unevenness was obtained.

(comparative example 1)

In Comparative Example 1, a test piece including white parts, black parts, and gray parts and having color unevenness was obtained by using a general-purpose injection molding apparatus not equipped with an inner cylinder.

(comparative example 2)

The inner cylinder of Comparative Example 2 had a total length of 44 mm and an inner diameter of 10 mm. The inner cylinder of Comparative Example 2 includes a first through hole, a second through hole, and a third through hole connecting the inner peripheral surface and the outer peripheral surface. The first through hole is located on the side closest to the first end portion (the upstream side of the molten resin, the rear end side of the nozzle). The second through hole is located on the second end side (downstream side of the molten resin, nozzle head side) than the first through hole. The third through hole is located on the second end side (downstream side of the molten resin, nozzle head side) than the second through hole. The first through hole, the second through hole, and the third through hole have a diameter of 3 mm. Three first through-holes, second through-holes, and third through-holes are arranged at equal intervals along the circumferential direction of the inner cylinder.

The inner cylinder of Comparative Example 2 includes first, second, and third protrusions on the outer peripheral surface of the inner cylinder. Each of the first protrusion, the second protrusion, and the third protrusion has a height of 2 mm and a width of 2 mm. Eight first protrusions, second protrusions, and third protrusions are each arranged at equal intervals along the circumferential direction of the inner cylinder. The total length in the circumferential direction of the inner cylinder of each of the first protrusion, the second protrusion, and the third protrusion is half the length of the outer circumference of the inner cylinder. The first protrusion is arranged on the second end side (downstream side of the molten resin, nozzle head side) with respect to the first through hole, and is arranged at the first end side (upstream side of the molten resin, on the nozzle head side) with respect to the second through hole. nozzle rear side). The second protrusion is arranged on the second end side (downstream side of the molten resin, nozzle head side) with respect to the second through hole, and is arranged at the first end side (upstream side of the molten resin, on the nozzle head side) with respect to the third through hole. nozzle rear side). The third protrusion is arranged on the second end side (downstream side of the molten resin, nozzle head side) with respect to the third through hole. By using the injection molding apparatus provided with the inner cylinder of the comparative example, a test piece having color unevenness was obtained including black streaks in a part of the gray molded product.

Although the embodiment of the present invention has been described, it should be understood that the embodiment disclosed this time is an illustration and not restrictive in all points. The scope of the present invention is shown by the claims, and it is intended that all modifications within the meaning and range equivalent to the claims are included.

Claims (15)

1. An injection nozzle, which is an injection nozzle for injecting molten resin, It includes: an outer cylinder having a nozzle head, and an inner cylinder arranged inside the outer cylinder, The inner cylinder includes: a molten resin storage portion for storing the molten resin, an outer peripheral surface, a plurality of through holes connecting the molten resin storage portion and the outer peripheral surface, and a plurality of protrusions provided on the outer peripheral surface. , a first end portion into which the molten resin flows, and a second end portion located on the nozzle head side compared to the first end portion, The flow rate of the molten resin passing through the through hole on the second end side is smaller than the flow rate of the molten resin passing through the through hole on the first end side. a plurality of through holes. 2 . The injection nozzle according to claim 1 , wherein the plurality of through holes are configured such that a flow rate of the molten resin becomes smaller as approaching the second end from the first end. 3. An injection nozzle, which is an injection nozzle for injecting molten resin, It includes: an outer cylinder having a nozzle head, and an inner cylinder arranged inside the outer cylinder, The inner cylinder includes a molten resin reservoir for storing the molten resin, an outer peripheral surface, a plurality of through holes communicating the molten resin reservoir and the outer peripheral surface, a plurality of protrusions provided on the outer peripheral surface, a first end into which the molten resin flows, and a second end on the nozzle head side of the first end, A total area in the circumferential direction of the inner cylinder of the through-holes located on the second end side is smaller than a total area in the circumferential direction of the inner cylinder of the through-holes located on the first end side. . 4. The injection nozzle according to claim 3, wherein the total area of the plurality of through-holes in the circumferential direction of the inner tube becomes smaller as approaching the second end from the first end. . 5. The injection nozzle according to any one of claims 1 to 4, wherein the through hole located on the second end side has a larger size than the through hole located on the first end side. Small size. 6. The injection nozzle according to any one of claims 1-4, wherein the size of the plurality of through-holes becomes smaller as approaching the second end from the first end. 7. The injection nozzle according to any one of claims 1 to 4, wherein the number of the through-holes located on the second end side is greater than the number of the through-holes located on the first end side The number is small. 8. The injection nozzle according to any one of claims 1 to 4, wherein the number of the plurality of through holes decreases as approaching the second end from the first end. 9. The injection nozzle according to any one of claims 1-4, wherein an opening of one of the outer peripheral surfaces of the inner tube of at least one of the through holes is connected to the at least one of the through holes. The other opening of the molten resin storage portion of the through hole is located on the side of the first end portion. 10. The injection nozzle according to any one of claims 1 to 4, wherein at least one of the protrusions has a surface at the first end when viewed from a normal direction of the outer peripheral surface of the inner cylinder. The side has an opening and the second end side is closed. 11. The injection nozzle according to any one of claims 1 to 4, wherein at least one of the protrusions is located at the first end when viewed from the direction normal to the outer peripheral surface of the inner cylinder. has a third end on one side, a fourth end on the second end side, and a central portion between the third end and the fourth end, and the third end and the The fourth end portion has a narrower width than the central portion. 12. An injection device comprising the injection nozzle according to any one of claims 1-4. 13. An injection molding device comprising the injection device according to claim 12, and a mold clamping device. 14. A method of injection comprising: melt the resin; supplying a first molten resin that is a portion of the resin to be melted to an injection nozzle; supplying a second molten resin as a part of the melted resin to the injection nozzle after the first molten resin; In the injection nozzle, the flow rate of the first molten resin is relatively smaller than the flow rate of the second molten resin; In the injection nozzle, kneading the first molten resin and the second molten resin whose flow rate is relatively smaller than that of the second molten resin; injecting the kneaded first molten resin and the second molten resin from the injection nozzle, The injection nozzle includes: an outer cylinder having a nozzle head, and an inner cylinder arranged inside the outer cylinder, The inner cylinder includes: a molten resin storage portion for storing the molten resin, an outer peripheral surface, a plurality of through holes connecting the molten resin storage portion and the outer peripheral surface, and multiple holes provided on the outer peripheral surface. a protrusion, a first end portion into which the melted resin flows, and a second end portion located on the nozzle head side compared to the first end portion, A total area in the circumferential direction of the inner cylinder of the through-holes located on the second end side is smaller than a total area in the circumferential direction of the inner cylinder of the through-holes located on the first end side. . 15. A method of injection molding comprising: injecting the kneaded first molten resin and the second molten resin into a mold by the injection method according to claim 14; The first molten resin and the second molten resin injected into the mold are cooled to obtain a solidified molded article.