JP2022144157A - Injection molding method and injection molding device - Google Patents

Abstract

To provide an injection molding method and injection molding device that prevent dripping in injection molding.SOLUTION: A nozzle 14 is provided on a lower end surface of a cylinder body 11 that holds molten resin and can be raised and lowered freely; a sub-nozzle part 2 having a sub-nozzle 22 and a temperature detection sensor 25 is arranged between the cylinder body 11 and a mold 3 below it; a plunger 12, which is raised and lowered inside the cylinder body 11, and the cylinder body 11 are lowered, to press the sub-nozzle 22 with the nozzle 14 on the lower end surface; so that the sub-nozzle 22 is coupled to a gate 34 of the mold 3, causing the mold 3 to be filled with a predetermined amount of molten resin. A start of molten resin filling is detected by a temperature of a resin detected by the temperature detection sensor 25. When the predetermined amount of molten resin has filled the mold 3, the plunger 12 is raised together with the cylinder body 11 to release the pressing of the sub-nozzle 22 by the nozzle 14, and simultaneously release the coupling between the sub-nozzle 22 and the gate 34.SELECTED DRAWING: Figure 1

Description

The present invention relates to an injection molding method and an injection molding apparatus for filling a mold with a molten resin to obtain an injection molded product.

Patent Document 1 describes an injection molding apparatus that prevents the dripping phenomenon in which the molten resin flows out from a nozzle for injecting the molten resin when an injection molded product is obtained by filling the mold with the molten resin. As shown in FIG. 8, the heat that heats the cylinder 201 is insulated, and the molten resin 203 remaining in the injection port path 202B of the injection nozzle portion 202 is released from the mold 204 when the mold 204 is released or when the injection nozzle portion 202 is removed from the mold 204. The injection nozzle portion 202 is provided with a heat insulating portion 205 that prevents the molten state from being maintained even when the injection nozzle portion 202 is separated from the mold 204. The molten resin 203 in the nozzle portion 202 solidifies or semi-solidifies, clogging the injection opening path 202B of the injection nozzle portion 202, and remaining molten resin from the injection opening 202A at the tip of the injection opening passage 202B of the injection nozzle portion 202. A drooping prevention structure in an injection molding machine is disclosed, which is configured to prevent drooping of 203 .

Further, as shown in FIG. 9, Patent Document 2 discloses an injection cylinder 302 that stores molding material and is provided with an injection nozzle 304 in front thereof, an injection plunger 303 that moves backward within the injection cylinder 302, and the injection plunger 303, an injection control device 306, and a position detection device 307 for detecting the position of the injection plunger 303. The retraction speed of the injection plunger 303 in the plasticization weighing step of the n-th injection cycle is calculated from the weighing time of the injection plunger 303 measured by the position detection device 307 in the weighing step, and the injection plunger 303 is moved at the retraction speed. Disclosed is an injection device 301 for retracting and metering. According to the injection device 301, the position detection device 307 for detecting the position of the injection plunger 303 is provided, and the weighing of the injection plunger 303 measured by the position detection device 307 in the plasticization weighing process of the n-1th injection cycle. By calculating the retraction speed of the injection plunger 303 in the plasticization weighing process of the n-th injection cycle from time, it becomes possible to retract the injection plunger 303 at an appropriate retraction speed, thereby preventing molding defects and drooping phenomena. It is possible to

However, neither of these Patent Documents 1 and 2 discloses that a sub-nozzle portion is provided between a nozzle for injecting a molten resin toward the mold and the mold to prevent the drooping phenomenon.

JP-A-9-85782 Japanese Patent No. 6795716

The present invention provides an injection molding method and injection molding apparatus in which molten resin is filled into the cavity space of the mold while the mold is closed, and which can be applied to large-shaped injection molded products. intended to

In the injection molding method according to claim 1 of the present invention, a nozzle is provided on the lower end surface of a cylinder body that holds molten resin and can be moved up and down, and a sub-nozzle is provided between the cylinder body and a mold arranged below it. A sub-nozzle portion having a temperature detection sensor is arranged, and a plunger that moves up and down in the cylinder body and a nozzle that is provided on the lower end surface of the cylinder body are lowered to press the sub-nozzle, thereby moving the sub-nozzle to the gate of the mold. and filling a predetermined amount of molten resin into a mold, wherein the start of filling of the molten resin is detected by the temperature of the resin detected by the temperature detection sensor, and the molten resin is placed in the mold. When a certain amount of fuel is filled, the plunger is lifted together with the cylinder body to release the pressure of the sub-nozzle by the nozzle, and at the same time, the sub-nozzle and the gate are released to cool the sub-nozzle.

The injection molding method according to claim 2 of the present invention is the injection molding method according to claim 1, wherein the mold is equipped with a filling detection sensor for monitoring a state in which the mold is filled with the molten resin, and When the detection sensor detects that the mold has been filled with a predetermined amount of molten resin, the plunger is lifted together with the cylinder body to release the sub-nozzle from being pressed by the nozzle and at the same time to release the connection between the sub-nozzle and the gate. It is characterized by

In the injection molding apparatus according to claim 3 of the present invention, a nozzle is provided on the lower end surface of a cylinder body that holds molten resin and can be moved up and down, and a plunger that can be moved up and down is provided in the cylinder body. and a sub-nozzle portion having a sub-nozzle and a temperature detection sensor is arranged between the mold arranged below the sub-nozzle and an urging means for pressing the sub-nozzle in the direction of the nozzle.

According to claim 4 of the present invention, there is provided an injection molding apparatus according to claim 3, wherein the sub-nozzle section has a flow path through which a cooling fluid is supplied.

According to claim 5 of the present invention, the injection molding apparatus according to claim 3 or 4, wherein the mold is provided with a filling detection sensor for monitoring a state in which the mold is filled with molten resin. It is characterized by

According to a sixth aspect of the present invention, there is provided the injection molding apparatus according to any one of the third to fifth aspects, wherein the cylinder body includes a resin melting portion having a through hole communicating with the nozzle. characterized by having

In the injection molding method and injection molding apparatus of the present invention, a nozzle is provided on the lower end surface of a cylinder body that holds molten resin and can be moved up and down, and a sub-nozzle and a temperature sensor are provided between the cylinder body and a mold arranged below the cylinder body. A sub-nozzle portion having a sensor is arranged, and a plunger that moves up and down in the cylinder body and a nozzle provided on the lower end surface of the cylinder body are lowered to press the sub-nozzle, thereby connecting the sub-nozzle to the gate of the mold. A method and apparatus for filling a predetermined amount of molten resin into a mold by allowing the temperature sensor to detect the start of filling of the molten resin, and filling the mold with the predetermined amount of molten resin. Then, the plunger is lifted together with the cylinder body to release the pressure of the sub-nozzle by the nozzle, and at the same time, the connection between the sub-nozzle and the gate is released and the sub-nozzle is cooled to obtain an injection molded product. Due to the presence of , it is possible to prevent drooping phenomenon in which the molten resin flows out from the nozzle of the resin-melting part, and molding control in injection molding is improved.

FIG. 4 is a cross-sectional view showing a preparatory stage of the manufacturing process in the injection molding apparatus of the present invention; FIG. 6 is a cross-sectional view taken along line AA in FIGS. 1 and 5; FIG. 6 is a cross-sectional view taken along the line BB in FIGS. 1 and 5; FIG. 4 is a plan view of a sub-nozzle in the injection molding apparatus of the present invention; FIG. 4 is a cross-sectional view showing the filling start stage of the manufacturing process in the injection molding apparatus of the present invention; FIG. 4 is a cross-sectional view showing the filling end stage of the manufacturing process in the injection molding apparatus of the present invention; It is a figure which shows the manufacturing process which manufactures an injection molded product with the injection molding apparatus of this invention. FIG. 4 is a cross-sectional view showing the completion of injection of the injection molding machine disclosed in Patent Document 1; 1 is a schematic configuration diagram including a cross section of an injection molding machine disclosed in Patent Document 2; FIG.

(Embodiment of injection molding apparatus)
Although one embodiment of the injection molding apparatus of the present invention will be described with reference to FIGS. 1 to 5, various modifications and modifications are possible without departing from the technical scope of the present invention.

In FIGS. 1 and 5, reference numeral 1 denotes a molten resin supply section, which includes a plunger 12 in a cylinder body 11 and a drive section 4 for reciprocating the cylinder body 11 up and down. A resin supply portion 13 is provided on the outer surface of the cylinder body 11 , and the resin supply portion 13 communicates with the inside of the cylinder body 11 to supply resin into the cylinder body 11 . The drive unit 4 includes a notch 42 formed in a post 41 erected on a base 36 on which the mold 3 is placed, a feed bar 43B formed on the outer surface of the cylinder body 11 for raising and lowering the cylinder body 11, and a A gear 44B at the tip of the bar 43B and meshing with the notch 42, a feed bar 43A connected to the shaft 121 of the plunger 12 to raise and lower the plunger 12, and a gear at the tip of the feed bar 43A and meshing with the notch 42. 44A, and these gears 44A and 44B are rotated by an electric motor (not shown). The feed bars 43A and 43B of the drive unit 4 may be interlocked, but when the plunger 12 and the cylinder body 11 are lowered, the plunger 12 may be lowered after the cylinder body 11 is lowered.

A nozzle 14 is provided on the lower end surface of the cylinder body 11 (lower surface in FIGS. 1 and 5). A heater 15 is formed on the outer peripheral surface of the cylinder body 11 surrounding the resin melting portion 16 .

A sub-nozzle part 2 is arranged between the nozzle 14 and the mold 3 . A sub-nozzle body 21 of the sub-nozzle part 2 is formed with a sub-nozzle 22 that protrudes toward the mold 3 side in communication with a nozzle receiving part 22A having a recess formed on the cylinder body 11 side. It is supported by a biasing member 24 that presses toward the nozzle 14 of the molten resin supply unit 1 in the direction away from the nozzle 3 . The urging members 24 are composed of a shaft 24A supported by the mold 3 and a spring 24B, and two pairs are arranged on the left and right sides of the sub-nozzle main body 21 in FIGS. As shown in FIG. 4, the sub-nozzle main body 21 is provided with a cooling member 23 so as to bypass the shaft 24A of the biasing member 24. Further, the sub-nozzle main body 21 is provided with a temperature detection sensor 25 for detecting the temperature of the resin. is provided. In this case, the biasing member 24 may be configured as a pair. Further, the shaft 24A of the biasing member 24 may be threaded and fixed to the mold 3 by screwing. Thus, when the sub-nozzle 22 of the sub-nozzle part 2 is coupled to the gate 34 of the mold 3 to fill the cavity 33 of the mold 3 with the molten resin A, the biasing member 24 using the shaft 24A is arranged to move the sub-nozzle part 2 vertically and horizontally. It acts as a support so that it does not move.

The mold 3 has a movable upper mold 31 and a fixed lower mold 32 on a base 36. The upper mold 31 and the lower mold 32 are closed to form a cavity 33 filled with molten resin. A gate 34 is formed in 31 and the sub-nozzle 22 is coupled to this gate 34 . Further, the lower mold 32 is provided with a filling detection sensor 35 that monitors the state of filling of the molten resin A into the cavity 33 by detecting the pressure and temperature of the mold 3 .

A drive control device 5 controls the drive unit 4 based on detection signals from the temperature detection sensor 25 and the filling detection sensor 35 .

FIG. 2 shows the arrangement of the plunger 12 and the resin supply section 13 in the cylinder body 11. The cylinder body 11 is cylindrical and is opened to the resin supply section 13 on the side surface, so that the resin supply section 13 is located between the cylinder body 11 and the cylinder body 11. , and resin such as thermoplastic resin is extruded toward the nozzle 14 by lowering the plunger 12 via the shaft 121 .

FIG. 3 shows the arrangement of the resin melting portion 16 and the heater 15 in the cylinder body 11 , and the heater 15 is formed on the outer peripheral surface of the cylinder body 11 . The heater 15 heats the resin extruded by lowering the plunger 12 through the shaft 121 to a temperature higher than the glass transition temperature of the resin to obtain a molten resin A (see FIGS. 5 and 6). Induction heating is used as the heat source. Also, the resin melting portion 16 is made of a columnar body having a plurality of through holes 16A. Although the resin melting portion 16 may be a cavity without a columnar body, by making the resin melting portion 16 a columnar body with a plurality of through holes 16A, the inside of the cylinder body 11 near the nozzle 14 is made only a cavity. Compared to the structure, the filling action of filling the cavity 33 of the mold 3 with the molten resin A (see FIGS. 5 and 6) from the sub-nozzle portion 2 can be improved.

4 is a plan view of the sub-nozzle portion 2 viewed from the nozzle 14 of the molten resin supply portion 1. A sub-nozzle body 21 in the center is formed with a sub-nozzle 22 having a nozzle receiving portion 22A. A cooling member 23 having a flow path through which a cooling fluid flows is formed inside. The cooling member 23 having this flow path has flow paths 23A and 23B extending left and right so as to bypass the shafts 24A of the two pairs of urging members 24 on both sides of the sub-nozzle body 21. 23B joins at an annular channel 23C and is connected to the cooling generator 6 . The cooling generating device 6 operates such that a cooling fluid such as air or water is circulated through a flow path from the flow path 23A through the annular flow path 23C to the flow path 23B by an electric pump (not shown). In this case, the plunger 12 is lifted together with the cylinder body 11 to release the pressure of the sub-nozzle 22 by the nozzle 14 and at the same time release the connection between the sub-nozzle 22 and the gate 34 to cool the sub-nozzle 22 . Instead of providing the sub-nozzle portion 2 with the cooling member 23 as a cooling device for cooling the sub-nozzle 22, the sub-nozzle 22 may be cooled by an external cooling member (not shown).

(Description of manufacturing process for manufacturing injection molded products using injection molding equipment)
A manufacturing process for manufacturing an injection-molded product by the injection molding apparatus of the present invention will be described below.

Injection molding using the injection molding apparatus of the present invention is performed by providing a nozzle 14 on the lower end surface of a cylinder body 11 that holds molten resin and can be moved up and down, and between the cylinder body 11 and the mold 3 arranged below it. A sub-nozzle part 2 having a sub-nozzle 22 and a temperature detection sensor 25 is arranged in the cylinder body 11, and the plunger 12 that moves up and down in the cylinder body 11 and the cylinder body 11 are lowered to press the sub-nozzle 22 with the nozzle 14 provided on the lower end surface. Thus, the sub-nozzle 22 is connected to the gate 34 of the mold 2 and the mold 3 is filled with a predetermined amount of molten resin A. When the start of filling is detected, and a predetermined amount of molten resin A is filled into the cavity 33 of the mold 3, the plunger 12 is lifted together with the cylinder body 11 to release the pressure of the sub-nozzle 22 by the nozzle 14, and at the same time, the sub-nozzle 22 and By releasing the connection with the gate 34 and cooling the sub-nozzle 22, an injection molded product is manufactured in the following manufacturing process.

In FIG. 7, the molten resin is injection-molded into a predetermined shape by a molten resin filling preparation step 100, a molten resin filling start step 101, a molten resin filling end step 102, and a holding pressure step 103. First, the molten resin filling preparation step 100 in FIG. .

Next, in the melted resin filling start step 101, the heater 15 is energized to energize the resin melting portion 16 so that the resin can be heated to the glass transition temperature or higher, the sub nozzle portion 2 is not cooled, and the temperature Based on the detection signal from the detection sensor 25 , the plunger 12 and the cylinder main body 11 are lowered by the driving section 4 and the sub-nozzle section 2 is pressed by the nozzle 14 . In this case, the plunger 12 is lowered together with the cylinder body 11 by the drive section 4 by interlocking the feed bars 43A and 43B of the drive section 4, and the cylinder body 11 is lowered to move the nozzle 14 to the nozzle receiving position of the sub-nozzle 22. After pressing the sub-nozzle part 2 by contacting the part 22A, the plunger 12 may be lowered. Subsequently, in FIG. 5, the plunger 12 and the cylinder body 11 are lowered by the driving portion 4, and the nozzle 14 is brought into contact with the nozzle receiving portion 22A of the sub-nozzle 22 to press the sub-nozzle portion 2 and project toward the mold 3 side. The sub-nozzle 22 is connected to the gate 34 of the mold 3, and the resin supplied from the resin supply part 13 to the cylinder body 11 is made into molten resin A in the resin melting part 16, and the molten resin A is poured into the cavity 33 of the mold 3. to fill. Then, while the pressure and temperature of the mold 3 are detected by the filling detection sensor 35 to monitor the filling of the cavity 33 with the molten resin, the filling of the molten resin into the cavity 33 is continued.

Then, the molten resin filling end step 102, in which the pressure and temperature of the mold 3 detected by the filling detection sensor 35 reach predetermined values, is as shown in FIG. A detection signal from the filling detection sensor 35 is sent to the drive control device 5, and the drive unit 4 raises the plunger 12 together with the cylinder body 11, causing the nozzle 14 to move the plunger 12 upward. When the sub-nozzle 22 is released from the pressure, the sub-nozzle 22 and the gate 34 of the mold 3 are released at the same time, and the cooling fluid is allowed to flow through the channels 23A, 23C and 23B of the cooling member 23 of the sub-nozzle part 2. . Then, the supply of electricity to the heater 15 of the resin melting portion 16 is stopped, the filling of the molten resin A is finished, and the holding pressure step 103 is reached.

In the holding pressure process 103, the mold 3 is held under pressure in a clamped state, the mold 3 is cooled, the mold 3 is opened, and injection molding is performed into a predetermined shape by a vertically movable ejector rod (not shown). The article is removed from the mold 3 to obtain an injection molded article.

In this way, the presence of the sub-nozzle portion 2 can prevent the drooping phenomenon in which the molten resin flows out from the nozzle 14 of the molten resin supply portion 1, thereby improving molding control in injection molding.

The injection molding apparatus of the present invention is useful for injection molding that requires prevention of drooping.

1 Molten resin supply part 11 Cylinder main body 12 Plunger 13 Resin supply part 14 Nozzle 15 Heater 16 Resin melting part 2 Sub-nozzle part 21 Sub-nozzle main body 22 Sub-nozzle 23 Cooling member 24 Biasing member 25 Temperature detection sensor 3 Mold 31 Upper mold 32 Lower Mold 33 Cavity 34 Gate 35 Filling detection sensor 4 Drive section 5 Drive control device 100 Molten resin filling preparation process 101 Molten resin filling start process 102 Molten resin filling end process 103 Holding pressure process

In the injection molding method according to claim 1 of the present invention, a nozzle is provided on the lower end surface of a cylinder body that holds a molten resin and can be moved up and down, and the cylinder is placed between the cylinder body and a mold arranged below it. A sub-nozzle part is arranged separately from the main body, and the sub- nozzle part has a sub-nozzle, a temperature detection sensor, and a flow path for supplying a cooling fluid, and a plunger that moves up and down in the cylinder body and descends the cylinder body. an injection molding method for filling a predetermined amount of molten resin into a mold by pressing the sub-nozzle with a nozzle provided on the lower end face of the mold, thereby coupling the sub-nozzle to the gate of the mold and filling the mold with a predetermined amount of molten resin; The start of filling of the molten resin is detected by the temperature of the resin detected in , and when the mold is filled with a predetermined amount of molten resin, the plunger is lifted together with the cylinder body to release the pressure of the sub-nozzle by the nozzle at the same time. The sub-nozzle is cooled by releasing the connection between the sub-nozzle and the gate.

In the injection molding apparatus according to claim 3 of the present invention, a nozzle is provided on the lower end surface of a cylinder body that holds molten resin and can be moved up and down, and a plunger that can be moved up and down is provided in the cylinder body. , a sub-nozzle portion which is separate from the cylinder main body is arranged between the mold arranged below it, the sub- nozzle portion has a sub-nozzle, a temperature detection sensor, and a flow path for supplying a cooling fluid , It is characterized by having an urging means for pressing the sub-nozzles in the nozzle direction.

According to claim 4 of the present invention, there is provided the injection molding apparatus according to claim 3 , wherein the mold is provided with a filling detection sensor for monitoring a state in which the mold is filled with the molten resin. Characterized by

According to claim 5 of the present invention, there is provided the injection molding apparatus according to claim 3 or 4 , wherein the cylinder body has a resin melting portion having a through hole communicating with the nozzle. do.

In the injection molding method and injection molding apparatus of the present invention, a nozzle is provided on the lower end surface of a cylinder body that holds a molten resin and can be moved up and down, and the cylinder body and the mold arranged below the cylinder body are provided. is a separate sub-nozzle unit, and the sub-nozzle unit has a sub-nozzle, a temperature detection sensor, and a flow path for supplying a cooling fluid. A method and apparatus for filling a mold with a predetermined amount of molten resin by pressing the sub-nozzle with a nozzle provided on the lower end surface to connect the sub-nozzle to the gate of the mold, wherein the temperature is detected by the temperature sensor. When the mold is filled with a predetermined amount of molten resin, the plunger is lifted together with the cylinder body to release the pressure of the sub-nozzle by the nozzle, and at the same time, the sub-nozzle and the sub-nozzle are released. Since an injection-molded product can be obtained by releasing the connection with the gate and cooling the sub-nozzle, the presence of the sub-nozzle part can prevent the drooping phenomenon in which the molten resin flows out from the nozzle of the resin-melting part. improves.

Claims (6)

A nozzle is provided on the lower end surface of a cylinder body that holds molten resin and can be raised and lowered, a sub-nozzle part having a sub-nozzle and a temperature detection sensor is arranged between the cylinder body and a mold arranged below it, and the cylinder body is arranged. By lowering the plunger that moves up and down inside and the cylinder body and pressing the sub-nozzle with the nozzle provided on the lower end surface, the sub-nozzle is connected to the gate of the mold and the mold is filled with a predetermined amount of molten resin. In the injection molding method, the start of filling of the molten resin is detected by the temperature of the resin detected by the temperature detection sensor, and when the mold is filled with a predetermined amount of molten resin, the plunger is moved together with the cylinder body. A method of injection molding, characterized in that the sub-nozzle is lifted to release the pressure of the nozzle on the sub-nozzle, and at the same time, the connection between the sub-nozzle and the gate is released to cool the sub-nozzle. The mold is provided with a filling detection sensor that monitors the state of filling of the mold with molten resin, and when the filling detection sensor detects that the mold is filled with a predetermined amount of molten resin, the plunger is 2. The injection molding method according to claim 1, wherein the sub-nozzle is lifted together with the cylinder body to release the pressure of the sub-nozzle by the nozzle, and at the same time, the connection between the sub-nozzle and the gate is released. A nozzle is provided on the lower end surface of a cylinder body that holds molten resin and can be raised and lowered, a plunger that can be raised and lowered is provided in the cylinder body, and a sub-nozzle is provided between the cylinder body and a mold arranged below it. An injection molding apparatus, comprising: a sub-nozzle portion having a temperature detection sensor; and biasing means for pressing the sub-nozzle toward the nozzle. 4. The injection molding apparatus according to claim 3, wherein the sub-nozzle portion has a flow path through which a cooling fluid is supplied. 5. The injection molding apparatus according to claim 3, wherein the mold is provided with a filling detection sensor for monitoring the state of filling of the mold with the molten resin. 6. The injection molding apparatus according to claim 3, wherein said cylinder body has a resin melting portion having a through hole communicating with said nozzle.

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