JP6941847B1 - Injection molding method and injection molding equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an injection molding method and an injection molding apparatus for preventing drooping in injection molding. SOLUTION: A nozzle 14 is provided on a lower end surface of a cylinder body 11 which holds a molten resin and can be raised and lowered, and has a sub-nozzle 22 and a temperature detection sensor 25 between the cylinder body 11 and a mold 3 arranged below the cylinder body 11. By arranging the sub-nozzle portion 2 and lowering the plunger 12 that moves up and down in the cylinder body 11 and the cylinder body 11 and pressing the sub-nozzle 22 with the nozzle 14 provided on the lower end surface, the sub-nozzle 22 is pressed by the gate 34 of the mold 3. The mold 3 is filled with a predetermined amount of molten resin. The start of filling of the molten resin is detected at the temperature of the resin detected by the temperature detection sensor 25, and when a predetermined amount of the molten resin is filled in the mold 3, the plunger 12 is raised together with the cylinder body 11 and the sub-nozzle by the nozzle 14 is used. At the same time as releasing the pressing of 22, the connection between the sub nozzle 22 and the gate 34 is released. [Selection diagram] Fig. 1

Description

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

Patent Document 1 describes an injection molding device that prevents the molten resin from flowing out from a nozzle that ejects the molten resin when the molten resin is filled in a mold to obtain an injection-molded product. As shown in FIG. 8, the heat that heats the cylinder 201 is insulated, and the molten resin 203 remaining in the injection port passage 202B of the injection nozzle portion 202 is when the mold 204 is removed or the injection nozzle portion 202 is the mold 204. A heat insulating portion 205 is provided in the injection nozzle portion 202 to prevent the injection nozzle portion 202 from maintaining the molten state even when the injection nozzle portion 202 is separated from the mold 204. The molten resin 203 in the nozzle portion 202 is solidified or semi-solidified, which clogs and blocks the injection port 202B of the injection nozzle 202, and the molten resin remaining from the injection port 202A at the tip of the injection port 202B of the injection nozzle 202. A structure for preventing a drooping phenomenon in an injection molding machine, which is configured to prevent the 203 from drooping, is disclosed.

Further, in Patent Document 2, as shown in FIG. 9, an injection cylinder 302 that stores a molding material and has an injection nozzle 304 in front, an injection plunger 303 that moves backward in the injection cylinder 302, and the injection plunger. An injection plunger drive device 305 for moving the 303 backward, an injection control device 306, and a position detection device 307 for detecting the position of the injection plunger 303 are provided, and the injection control device 306 is plastic for the n-1th injection cycle. The retreat speed of the injection plunger 303 in the plastic molding measurement step of the nth injection cycle is calculated from the measurement time of the injection plunger 303 measured by the position detection device 307 in the molding measurement step, and the retreat speed is used to calculate the retreat speed of the injection plunger 303. The injection device 301 that performs weighing by retracting the molding device 301 is disclosed. According to the injection device 301, the position detection device 307 for detecting the position of the injection plunger 303 is provided, and the measurement of the injection plunger 303 measured by the position detection device 307 in the plastic molding measurement step of the n-1th injection cycle is provided. By calculating the retreat speed of the injection plunger 303 in the plastic measurement step of the nth injection cycle from the time, it is possible to retreat the injection plunger 303 at an appropriate retreat speed, and molding defects and sagging phenomena are prevented. It is possible to do.

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

Japanese Unexamined Patent Publication No. 9-85782 Japanese Patent No. 6795716

The present invention provides an injection molding method and an injection molding apparatus in which a molten resin is filled in a cavity space of a mold with the mold closed, and which can be applied to an injection molded product having a large shape. The purpose is to do.

Injection molding method according to claim 1 of the present invention, a nozzle is provided on the lower end surface of the vertically movable cylinder body holds a molten resin, the cylinder between said cylinder body, and a mold arranged thereunder A sub-nozzle portion that is separate from the main body is arranged, and the sub-nozzle portion has a sub-nozzle, a temperature detection sensor, and a flow path to which a cooling fluid is supplied , and lowers the plunger that moves up and down in the cylinder body and the cylinder body. This is an injection molding method in which the sub-nozzle is pressed with a nozzle provided on the lower end surface to connect the sub-nozzle to the gate of the mold and fill the mold with a predetermined amount of molten resin. When the start of filling of the molten resin is detected at the temperature of the resin detected in the above, and when a predetermined amount of the molten resin is filled in the mold, the plunger is raised together with the cylinder body to release the pressing of the sub-nozzle by the nozzle at the same time. It is characterized in that the coupling between the sub-nozzle and the gate is 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 includes a filling detection sensor for monitoring a state in which the molten resin is filled in the mold, and the filling is provided. When the detection sensor detects that the mold is filled with the molten resin in a predetermined amount, the plunger is raised together with the cylinder body to release the pressing of the sub-nozzle by the nozzle, and at the same time, the connection between the sub-nozzle and the gate is released. It is characterized by that.

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

The injection molding apparatus according to claim 4 of the present invention is 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 molten resin is filled in the mold. It is a feature.

The injection molding apparatus according to claim 5 of the present invention is 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 molten resin and can be raised and lowered, and the cylinder body and the cylinder body are placed between the cylinder body and a mold arranged below the cylinder body. Arranges a separate sub-nozzle portion, which has a sub-nozzle, a temperature detection sensor, and a flow path to which a cooling fluid is supplied , and lowers the plunger that moves up and down in the cylinder body and the cylinder body. A method and apparatus for connecting the sub-nozzle to the gate of the mold by pressing the sub-nozzle with a nozzle provided on the lower end surface to fill the mold with a predetermined amount of molten resin, which is detected by the temperature detection sensor. When the start of filling of the molten resin is detected at the temperature of the resin, and a predetermined amount of the molten resin is filled in the mold, the plunger is raised together with the cylinder body to release the pressing of the sub-nozzle by the nozzle, and at the same time, the sub-nozzle and the sub-nozzle. Since an injection-molded product can be obtained by releasing the coupling with the gate and cooling the sub-nozzle, the presence of the sub-nozzle can prevent the molten resin from flowing out from the nozzle of the resin melting part, and molding control in injection molding. Is improved.

It is sectional drawing which shows the preparatory stage of the manufacturing process in the injection molding apparatus of this invention. FIG. 5 is a cross-sectional view taken along the line AA in FIGS. 1 and 5. It is a cross-sectional view of BB in FIGS. 1 and 5. It is a top view of the sub-nozzle in the injection molding apparatus of this invention. It is sectional drawing which shows the filling start stage of the manufacturing process in the injection molding apparatus of this invention. It is sectional drawing which shows the filling end stage of the manufacturing process in the injection molding apparatus of this invention. It is a figure which shows the manufacturing process which manufactures an injection-molded article by the injection-molding apparatus of this invention. It is sectional drawing which shows the time of completion of injection of the injection molding machine disclosed in Patent Document 1. It is a schematic block diagram including the cross section of the injection molding machine disclosed in Patent Document 2.

(Embodiment of Injection Molding Device)
An embodiment of the injection molding apparatus of the present invention will be described with reference to FIGS. 1 to 5, but various modifications and modifications can be made without departing from the technical scope of the present invention.

In FIGS. 1 and 5, reference numeral 1 denotes a molten resin supply unit, which includes a plunger 12 in the cylinder body 11 and a drive unit 4 for reciprocating the cylinder body 11 up and down. A resin supply unit 13 is provided on the outer surface of the cylinder body 11, and the resin supply unit 13 communicates with the inside of the cylinder body 11 to supply the resin into the cylinder body 11. The drive unit 4 includes a notch 42 formed in a support column 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 to raise and lower the cylinder body 11, and this feed. A gear 44B at the tip of the bar 43B that meshes with the notch 42, a feed bar 43A that is 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 that meshes with the notch 42. 44A and these gears 44A and 44B are rotated by an electric motor (not shown). The feed bar 43A and the feed bar 43B of the drive unit 4 may be interlocked with each other, but when the plunger 12 and the cylinder body 11 are lowered, the cylinder body 11 may be lowered and then the plunger 12 may be lowered.

Further, a nozzle 14 is provided on the lower end surface (lower surface in FIGS. 1 and 5) of the cylinder body 11, and a resin melting portion 16 is provided in the cylinder body 11 between the nozzle 14 and the resin supply portion 13. A heater 15 is formed on the outer peripheral surface of the cylinder body 11 surrounding the resin melting portion 16.

The sub-nozzle portion 2 is arranged between the nozzle 14 and the mold 3. The sub-nozzle body 21 of the sub-nozzle portion 2 is formed with a sub-nozzle 22 that communicates with a nozzle receiving portion 22A having a recess formed on the cylinder body 11 side and projects toward the mold 3 side, and the sub-nozzle 22 is a mold. It is supported by an urging member 24 that presses the molten resin supply unit 1 toward the nozzle 14 in a direction away from 3. The urging member 24 includes a shaft 24A supported by the mold 3 and a spring 24B, and in FIGS. 1 and 5, two pairs are arranged on the left and right sides of the sub-nozzle main body 21. 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 urging member 24, and 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 urging members 24 may be configured as a pair. Further, a screw may be formed on the shaft 24A of the urging member 24 and screwed to the mold 3 to fix the screw. In this way, in the urging member 24 using the shaft 24A, when the sub-nozzle 22 of the sub-nozzle portion 2 is coupled to the gate 34 of the mold 3 and the molten resin A is filled into the cavity 33 of the mold 3, the sub-nozzle portion 2 is vertically and horizontally arranged. It acts as a support to prevent it from moving.

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

Reference numeral 5 denotes a drive control device, which controls the drive unit 4 based on the 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 unit 13 in the cylinder body 11. The cylinder body 11 is cylindrical and is opened to the resin supply unit 13 on the side surface, so that the resin supply unit 13 becomes the cylinder-main body 11. A resin such as a thermoplastic resin is pushed out 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 electromagnetically heats the resin extruded by lowering the plunger 12 via the shaft 121 to a temperature equal to or higher than the glass transition temperature of the resin to obtain the molten resin A (see FIGS. 5 and 6). Induction heating is used as the heat source. Further, the resin melting portion 16 is made of a columnar body having a plurality of through holes 16A. The resin melting portion 16 may be a cavity without a columnar body, but by forming the resin melting portion 16 into a columnar body having a plurality of through holes 16A, the inside of the cylinder body 11 near the nozzle 14 is only a cavity. Compared to the structure, the filling action of filling the molten resin A (see FIGS. 5 and 6) from the sub-nozzle portion 2 into the cavity 33 of the mold 3 can be improved.

FIG. 4 is a plan view of the sub-nozzle portion 2 as viewed from the nozzle 14 of the molten resin supply portion 1. The sub-nozzle main 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 the cooling fluid flows is formed inside. The cooling member 23 having this flow path has flow paths 23A and 23B extending to the 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 main body 21, and the flow paths 23A, The 23B merges with the annular flow path 23C and is connected to the cooling generator 6. The cooling generator 6 acts so that a cooling fluid such as air or water circulates in a flow path from the flow path 23A to the flow path 23B via the annular flow path 23C by an electric pump (not shown). In this case, 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 at the same time, the coupling between the sub-nozzle 22 and the gate 34 is released to cool the sub-nozzle 22. Instead of providing the sub-nozzle portion 2 with a 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).

(Explanation of manufacturing process for manufacturing injection molded products by injection molding equipment)
The manufacturing process for manufacturing an injection molded product by the injection molding apparatus of the present invention will be described below.

In injection molding using the injection molding apparatus of the present invention, a nozzle 14 is provided on the lower end surface of a cylinder body 11 that holds molten resin and can be raised and lowered, and is between the cylinder body 11 and a mold 3 arranged below the nozzle 14. A sub-nozzle portion 2 having a sub-nozzle 22 and a temperature detection sensor 25 is arranged therein, 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 a nozzle 14 provided on the lower end surface. This is a method in which the sub-nozzle 22 is coupled to the gate 34 of the mold 2 to fill the mold 3 with a predetermined amount of the molten resin A, and the molten resin A is at the temperature of the resin detected by the temperature detection sensor 25. When a predetermined amount of the molten resin A is filled in the cavity 33 of the mold 3 by detecting the start of filling, 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 at the same time, the sub-nozzle 22 and the sub-nozzle 22 are released. By releasing the coupling 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 the molten resin filling preparation step 100, the molten resin filling start step 101, the molten resin filling end step 102, and the pressure holding step 103. First, in the molten resin filling preparation step 100, in FIG. 1, the mold 3 is closed, the plunger 12 is moved upward, the sub-nozzle portion 2 is cooled, and the nozzle 14 and the sub-nozzle portion 2 are separated from each other. ..

Next, in the molten 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 a temperature equal to or higher than the glass transition temperature, and the sub-nozzle portion 2 is not cooled. Based on the detection signal from the detection sensor 25, the drive unit 4 lowers the plunger 12 and the cylinder body 11, and the nozzle 14 presses the sub-nozzle unit 2. In this case, the feed bar 43A and the feed bar 43B of the drive unit 4 are interlocked to lower the plunger 12 together with the cylinder body 11 by the drive unit 4, but the cylinder body 11 is lowered to receive the nozzle 14 as the nozzle of the sub nozzle 22. After contacting the portion 22A and pressing the sub-nozzle portion 2, the plunger 12 may be lowered. Subsequently, in FIG. 5, the plunger 12 and the cylinder body 11 are lowered by the drive unit 4, the nozzle 14 is brought into contact with the nozzle receiving portion 22A of the sub nozzle 22, and the sub nozzle portion 2 is pressed and protrudes toward the mold 3. The sub-nozzle 22 is coupled to the gate 34 of the mold 3, the resin supplied from the resin supply unit 13 to the cylinder body 11 is used as the molten resin A by the resin melting unit 16, and the molten resin A is used as the cavity 33 of the mold 3. Fill. Then, the filling detection sensor 35 detects the pressure and temperature of the mold 3, and while monitoring the filling of the molten resin in the cavity 33, the filling of the molten resin into the cavity 33 is continued.

Then, in 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, in FIG. 6, the molten resin A is the cavity of the mold 3 by the filling detection sensor 35. It is detected that the 33 is filled with a predetermined amount, a detection signal from the filling detection sensor 35 is sent to the drive control device 5, the plunger 12 is raised together with the cylinder body 11 by the drive unit 4, and the nozzle 14 is used. At the same time as releasing the pressing of the sub-nozzle 22, the coupling between the sub-nozzle 22 and the gate 34 of the mold 3 is released, and the cooling fluid is circulated through the flow path 23A, the annular flow path 23C, and the flow path 23B of the cooling member 23 of the sub-nozzle portion 2. .. Then, the energization of the resin melting unit 16 to the heater 15 is stopped, the filling of the molten resin A is completed, and the pressure holding step 103 is reached.

In the pressure holding step 103, the mold 3 is held in a mold-tightened state, the mold 3 is cooled, the mold 3 is opened, and injection molding is formed into a predetermined shape by a vertically movable ejector rod (not shown). The product is taken out from the mold 3 to obtain an injection-molded product.

As described above, the presence of the sub-nozzle unit 2 can prevent the molten resin from flowing out from the nozzle 14 of the molten resin supply unit 1, and improve the molding control in injection molding.

The injection molding apparatus of the present invention is useful for injection molding in which it is necessary to prevent the drooping phenomenon.

1 Molten resin supply part 11 Cylinder body 12 Plunger 13 Resin supply part 14 Nozzle 15 Heater 16 Resin melting part 2 Sub-nozzle part 21 Sub-nozzle 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 unit 5 Drive control device 100 Molten resin filling preparation process 101 Molten resin filling start process 102 Molten resin filling end process 103 Pressure holding process

Claims (5)

Holds molten resin nozzle provided at the lower end surface of the vertically movable cylinder body, arranged with the cylinder body, the sub-nozzle portion and the cylinder body are separate between the mold arranged thereunder, wherein The sub-nozzle portion has a sub-nozzle, a temperature detection sensor, and a flow path to which a cooling fluid is supplied, and presses the sub-nozzle with a plunger that moves up and down in the cylinder body and a nozzle that lowers the cylinder body and is provided on the lower end surface. This is an injection molding method in which the sub-nozzle is coupled to the gate of the mold and a predetermined amount of molten resin is filled in the mold, and the filling of the molten resin is started at the temperature of the resin detected by the temperature detection sensor. When it is detected and a predetermined amount of molten resin is filled in the mold, the plunger is raised together with the cylinder body to release the pressing of the sub-nozzle by the nozzle, and at the same time, the connection between the sub-nozzle and the gate is released to cool the sub-nozzle. An injection molding method characterized by that. The mold is provided with a filling detection sensor that monitors the state in which the molten resin is filled in the mold, and when the filling detection sensor detects that the mold is filled with a predetermined amount of the molten resin, the plunger is loaded. The injection molding method according to claim 1, wherein the injection molding method is raised together with the cylinder body to release the pressing of the sub-nozzle by the nozzle and at the same time release the coupling between the sub-nozzle and the gate. Holds molten resin nozzle provided at the lower end surface of the vertically movable cylinder body having a plunger movable up and down in the cylinder body, the cylinder between said cylinder body, and a mold arranged thereunder A sub-nozzle portion that is separate from the main body is arranged, and the sub-nozzle portion has a sub-nozzle, a temperature detection sensor, and a flow path to which a cooling fluid is supplied , and has an urging means for pressing the sub-nozzle in the nozzle direction. A featured injection molding device. The injection molding apparatus according to claim 3 , wherein the mold is provided with a filling detection sensor that monitors a state in which the molten resin is filled in the mold. 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.

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