Injection molding device

Abstract

To provide a technology capable of downsizing an injection molding apparatus.SOLUTION: An injection molding apparatus includes a fixed mold having a first gate opening and a second gate opening, a movable mold configured to be clampable to the fixed mold, a first injection unit injecting a first molding material through the first gate opening into a cavity defined by the fixed mold and the movable mold, and a second injection unit injecting a second molding material into the cavity through the second gate opening.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to an injection molding apparatus.

Background Art

[0002] The injection molding apparatus disclosed in Patent Document 1 includes a plasticizing device that plasticizes a material by a rotor having a spiral groove formed on an end face and a barrel that abuts against the end face of the rotor.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By adopting a rotor as in the above document, the plasticizing device can be miniaturized. However, generally, when performing injection molding using a mold having a cavity with a large projected area, the required injection pressure and mold clamping pressure increase, making it difficult to miniaturize the entire device.

Means for Solving the Problems

[0005] According to a first aspect of the present disclosure, an injection molding apparatus is provided. The injection molding apparatus includes a fixed mold in which a first gate opening and a second gate opening are formed, a movable mold configured to be mold-clamped to the fixed mold, a first injection unit that injects a first molding material into a cavity partitioned by the fixed mold and the movable mold through the first gate opening, and a second injection unit that injects a second molding material into the cavity through the second gate opening.

Brief Description of the Drawings

[0006] [Figure 1]This is a front view showing the schematic configuration of the injection molding apparatus in the first embodiment. [Figure 2] This is a side view showing the schematic configuration of an injection molding apparatus. [Figure 3] This is a cross-sectional view showing the schematic configuration of the injection unit. [Figure 4] This is a perspective view showing the schematic configuration of a flat screw. [Figure 5] This is a schematic plan view of the barrel. [Figure 6] This is a schematic diagram showing the process of opening a molding die. [Figure 7] This is a schematic diagram showing the mold opening process in a comparative example. [Figure 8] The first figure shows an example of the placement of the injection unit relative to the cavity. [Figure 9] The second figure shows an example of the placement of the injection unit relative to the cavity. [Figure 10] This figure shows an example where multiple cavities are formed in a mold. [Figure 11] This figure shows the schematic configuration of the injection molding apparatus in the second embodiment. [Figure 12] This is an explanatory diagram showing an example of the molding process in the second embodiment. [Figure 13] This diagram shows variations in multi-color molding. [Modes for carrying out the invention]

[0007] A. First Embodiment: Figure 1 is a front view showing the schematic configuration of the injection molding apparatus 10 in the first embodiment. Figure 2 is a side view showing the schematic configuration of the injection molding apparatus 10. Figures 1 and 2 show arrows indicating the mutually orthogonal X, Y, and Z directions. The X and Y directions are parallel to the horizontal plane, and the Z direction is opposite to the direction of gravity. The X, Y, and Z directions shown in Figure 3 and subsequent figures correspond to the X, Y, and Z directions shown in Figures 1 and 2. In the following description, when specifying a direction, the positive direction indicated by the arrow will be denoted as "+" and the negative direction opposite to the direction indicated by the arrow will be denoted as "-", and positive and negative signs will be used in conjunction with the direction notation.

[0008] As shown in Figure 1, the injection molding apparatus 10 comprises an injection unit 100 and a clamping device 130. The injection molding apparatus 10 is a horizontal injection molding apparatus, and the injection unit 100 and the clamping device 130 are arranged horizontally. The injection unit 100 and the clamping device 130 are each fixed to a base 20. The base 20 is equipped with a control unit 500. The injection molding apparatus 10 forms a molded product by injecting molding material from the injection unit 100 into a mold 160 mounted on the clamping device 130. In this embodiment, a metal mold 160 is mounted on the clamping device 130. The mold 160 mounted on the clamping device 130 is not limited to metal, but may be made of resin or ceramic. A metal mold 160 is called a mold. The mold 160 includes a fixed mold 161 and a movable mold 162. The fixed mold 161 is a mold fixed to the injection unit 100, and the movable mold 162 is a mold that moves relative to the fixed mold 161 and is configured to be clamped onto the fixed mold 161. The fixed mold 161 is also called the first mold or female mold, and the movable mold 162 is also called the second mold or male mold.

[0009] The mold clamping device 130 has the function of opening and closing the fixed mold 161 and the movable mold 162. Under the control of the control unit 500, the mold clamping device 130 rotates a ball screw 132 by driving a mold drive unit 131, which is composed of a motor, and moves the movable mold 162, which is coupled to the ball screw 132, relative to the fixed mold 161 to open and close the molding mold 160. In other words, the fixed mold 161 is stationary in the injection molding apparatus 10, and the molding mold 160 is opened and closed by the relative movement of the movable mold 162 with respect to the stationary fixed mold 161. In this embodiment, the movable mold 162 moves in the -Y direction, which is the direction intersecting the vertical direction, to perform mold clamping.

[0010] The movable mold 162 has one or more ejector pins 166 embedded in it. The ejector pins 166 are rod-shaped members that release the molded product formed in the cavity 165 from the movable mold 162 when the movable mold 162 is moved. The ejector pins 166 are provided to penetrate the movable mold 162 and reach the cavity 165. The rear end of the ejector pins 166 is supported by a support plate 167. A support rod 168 is fixed to the support plate 167, and the support rod 168 is inserted through a through hole formed in the movable mold 162. A spring 169 is inserted into the support rod 168 and is positioned in the space between the movable mold 162 and the support plate 167. The spring 169 biases the support plate 167 so that the head of the ejector pin 166 forms part of the wall surface of the cavity 165 during molding. An extruded plate 164 is fixed to the side of the support plate 167 facing the ball screw 132. A thrust bearing 163 is attached to the side of the extruded plate 164 facing the ball screw 132. The head of the ball screw 132 can contact the thrust bearing 163. A thrust sliding bearing or the like may be used instead of the thrust bearing 163.

[0011] The injection unit 100 comprises a plurality of injection units 140. As shown in Figure 2, in this embodiment, the plurality of injection units 140 include a first injection unit 141, a second injection unit 142, a third injection unit 143, and a fourth injection unit 144. When referring to these injection units without distinction, they are simply called injection units 140. In this embodiment, the injection units 140 are arranged in two rows each in the X direction and the Z direction in the injection unit 100.

[0012] Each injection unit 140 is connected to a hopper 30 into which the material for the molded product is fed. For example, a thermoplastic resin formed into pellets is used as the material for the molded product. Examples of thermoplastic resins include ABS (acrylonitrile butadiene styrene), PC (polycarbonate), POM (polyacetal), PP (polypropylene), and PBT (polybutylene terephthalate). The hopper 30 provided in each injection unit 140 can be filled with the same or different materials. In this embodiment, the same material is fed into all hoppers 30. The supply of material to the injection unit 140 is not limited to the hopper 30; for example, it may be done via a tube through which the material is pumped.

[0013] Each injection unit 140 plasticizes at least a portion of the material supplied from the hopper 30 to produce a molding material, and injects the molding material into a cavity 165 partitioned between the fixed mold 161 and the movable mold 162. In this embodiment, "plasticization" means that a thermoplastic material is heated and melted. Furthermore, "melting" means not only that a thermoplastic material becomes liquid when heated to a temperature above its melting point, but also that a thermoplastic material softens and becomes fluid when heated to a temperature above its glass transition point.

[0014] In the fixed mold 161, a first gate opening 171, a second gate opening 172, a third gate opening 173, and a fourth gate opening 174 are formed. Through the first gate opening 171, a first molding material is injected from the first injection unit 141 into the cavity 165. Through the second gate opening 172, a second molding material is injected from the second injection unit 142 into the cavity 165. Through the third gate opening 173, a third molding material is injected from the third injection unit 143 into the cavity 165. Through the fourth gate opening 174, a fourth molding material is injected from the fourth injection unit 144 into the cavity 165.

[0015] In this embodiment, the second injection unit 142 injects the second molding material into the cavity 165 where the first injection unit 141 injects the first molding material. The third injection unit 143 injects the third molding material into the cavity 165 where the first injection unit 141 and the second injection unit 142 inject the first molding material and the second molding material. The fourth injection unit 144 injects the fourth molding material into the cavity 165 where the first injection unit 141, the second injection unit 142, and the third injection unit 143 inject the first molding material, the second molding material, and the third molding material. In this embodiment, the first molding material, the second molding material, the third molding material, and the fourth molding material are all the same material.

[0016] In this embodiment, an operation including clamping of the fixed mold 161 and the movable mold 162 and injection into the cavity 165 through each gate opening from each of the injection units 140 is performed once, whereby a molded product is molded. That is, the molded product is not molded through multiple injections, but is molded by a single injection.

[0017] The control unit 500 is comprised of a computer comprising one or more processors, main memory, and an input / output interface for inputting and outputting signals to and from the outside. The processor loads and executes a program from the main memory, thereby controlling the injection unit 100 and the clamping device 130 to manufacture molded products. The control unit 500 can individually set injection conditions for each injection unit 140. Each injection unit 140 can inject molding material according to the individually set injection conditions. The injection conditions include, for example, at least one of injection pressure, injection speed, injection temperature, and injection timing.

[0018] Figure 3 is a cross-sectional view showing the schematic configuration of the injection unit 140. For ease of illustration, in Figure 3, the parts are shown with the +Y direction, which is to the right in Figure 1, pointing downwards. The injection unit 140 comprises a plasticizing section 110, an injection control mechanism 120, and a nozzle 114.

[0019] The plasticizing section 110 includes a flat screw 111, a barrel 112, and a heater 113. The flat screw 111 is housed in a housing section 101. The flat screw 111 is also called a rotor or simply a screw. The flat screw 111 is rotationally driven by a drive motor 118 within the housing section 101 around the rotation axis RX. In this embodiment, the direction of the rotation axis RX is along the Y direction. A communication hole 116 is formed in the center of the barrel 112. An injection cylinder 121, which will be described later, is connected to the communication hole 116. A check valve 124 is provided in the communication hole 116 upstream of the injection cylinder 121. The rotation of the flat screw 111 by the drive motor 118 and the heating by the heater 113 are controlled by a control unit 500.

[0020] Figure 4 is a perspective view showing the schematic configuration of the flat screw 111. The flat screw 111 has a substantially cylindrical shape in which the height in the direction along its central axis is smaller than its diameter. On the groove-forming surface 201 of the flat screw 111 facing the barrel 112, a spiral groove 202 is formed, centered on the central part 205. The groove 202 communicates with a material inlet 203 formed on the side of the flat screw 111. The material supplied from the hopper 30 is supplied to the groove 202 through the material inlet 203. The groove 202 is formed by being separated by a protruding ridge 204. Figure 4 shows an example in which three grooves 202 are formed, but the number of grooves 202 may be one or two or more. Note that the groove 202 is not limited to a spiral shape, but may also be helical or involute curved, or may extend in an arc from the center toward the outer circumference.

[0021] Figure 5 is a schematic plan view of the barrel 112. The barrel 112 has an opposing surface 212 that faces the groove-forming surface 201 of the flat screw 111. A communication hole 116 is formed in the center of the opposing surface 212. Multiple guide grooves 211 are formed on the opposing surface 212, connected to the communication hole 116 and extending in a spiral shape from the communication hole 116 toward the outer circumference. The material supplied to the groove 202 of the flat screw 111 is plasticized between the flat screw 111 and the barrel 112 by the rotation of the flat screw 111 and the heating of the heater 113, and flows along the groove 202 and guide grooves 211 as the flat screw 111 rotates, and is guided to the central part 205 of the flat screw 111. The material that has flowed into the central part 205 flows out to the injection control mechanism 120 from the communication hole 116 provided in the center of the barrel 112. Note that the barrel 112 does not necessarily have to be provided with guide grooves 211. Furthermore, the guide groove 211 does not necessarily have to be connected to the communication hole 116.

[0022] As shown in Figure 3, the injection control mechanism 120 includes an injection cylinder 121, a plunger 122, and a plunger drive unit 123. The injection control mechanism 120 has the function of injecting the molding material in the injection cylinder 121 into the cavity 165. Under the control of the control unit 500, the injection control mechanism 120 controls the amount of molding material injected from the nozzle 114, the injection speed, and the injection pressure. The injection cylinder 121 is a substantially cylindrical member connected to the communication hole 116 of the barrel 112 and has a plunger 122 inside. The plunger 122 slides inside the injection cylinder 121 and pressurizes the molding material in the injection cylinder 121 to the nozzle 114 provided in the injection unit 100. The plunger 122 is driven by a plunger drive unit 123 which is configured as a motor. The molding material, which is pressurized into the nozzle 114, is injected from the nozzle 114 through the gate opening into the cavity 165.

[0023] In this embodiment, the nozzle 114 is configured as a hot runner nozzle. A heater is placed around the nozzle 114, and the control unit 500 controls the heating temperature and injection temperature of the molding material by controlling the heater. The gate structure of the hot runner nozzle may be an open gate or a valve gate.

[0024] Figure 6 is a schematic diagram showing the opening of the mold 160. After the molding material is injected into the cavity 165 and held and cooled, the clamping device 130 shown in Figure 1 drives the ball screw 132 to move the movable mold 162 a predetermined distance in the +Y direction relative to the fixed mold 161, as shown in Figure 6. When this happens, the -Y side end of the ball screw 132 comes into contact with the thrust bearing 163, and the ejector pin 166 stops moving further in the +X direction. In this state, if the movable mold 162 is moved further in the +Y direction, the ejector pin 166 comes into contact with the molded product MD, and only the movable mold 162 moves in the +Y direction, so the ejector pin 166 pushes the molded product MD in the cavity 165 relatively, and the molded product MD is released from the movable mold 162. In other words, in this embodiment, the ejector pin 166 pushes the molded product MD out of the movable mold 162 by relatively protruding from the movable mold 162 toward the fixed mold 161 as the mold opens, moving the movable mold 162 away from the fixed mold 161. With this configuration, a mechanism to move the ejector pin 166 itself is unnecessary, thus simplifying the configuration of the injection molding apparatus 10.

[0025] In the injection molding apparatus 10 of the first embodiment described above, molding material is injected from multiple injection units through each gate opening into a cavity 165 partitioned by a fixed mold 161 and a movable mold 162. Specifically, for example, molding material is injected from the first injection unit 141 through the first gate opening 171, and molding material is injected from the second injection unit 142 through the second gate opening 172. In this embodiment, since molding material can be injected into a single cavity 165 from multiple injection units 140 in this way, it becomes easy to distribute the molding material throughout the cavity 165 even if the injection pressure and clamping pressure are low. Furthermore, according to this embodiment, even if the projected area of ​​the cavity 165 is large, the injection pressure and clamping pressure required in injection molding can be reduced, so the injection control mechanism 120 and the clamping device 130 can be miniaturized relative to the projected area of ​​the cavity 165. The projected area of ​​the cavity 165 is the area of ​​the cavity 165 when viewed in the direction of movement of the movable mold 162.

[0026] Furthermore, in this embodiment, each injection unit 140 can perform injection according to individually set injection conditions. Therefore, for example, by changing the injection conditions of each injection unit 140 without modifying or creating a new mold, problems such as insufficient filling and warping can be addressed, and the quality of the molded product can be improved. Also, for example, by changing the injection conditions of each injection unit 140, it is possible to arbitrarily adjust the position of the weld line in the molded product.

[0027] Furthermore, in this embodiment, since each injection unit 140 can inject not only the same molding material but also different molding materials, it is possible to easily mold not only a molded product made of the same molding material, but also a molded product having multiple parts molded from different molding materials.

[0028] Furthermore, in this embodiment, as shown in Figure 6, as the mold opens to move the movable mold 162 away from the fixed mold 161, the ejector pin 166 protrudes relatively from the movable mold 162 toward the fixed mold 161, thereby pushing the molded product MD out of the movable mold 162. In contrast, in the comparative example shown in Figure 7, the movable mold 162 is moved a predetermined distance in the +Y direction relative to the fixed mold 161, then the movable mold 162 is stopped, and the ejector pin 166 itself is moved in the -Y direction. Therefore, in the comparative example, the molded product MD also moves along with the movement of the ejector pin 166, and the distance d2 between the fixed mold 161 and the molded product MD at the time of demolding becomes shorter than the distance d between the fixed mold 161 and the molded product MD before the ejector pin 166 was moved in the -Y direction. In other words, when the ejector pin 166 itself is moved, there is a higher possibility that the position where the molded product MD is demolded will vary with each molding. However, in this embodiment, as shown in Figure 6, demolding is performed by moving the movable mold 162 instead of the ejector pin 166. Therefore, the molded product MD can be demolded from the movable mold 162 without changing the distance d between the fixed mold 161 and the molded product before and after demolding. As a result, the molded product can be accurately removed by a removal device such as a robot.

[0029] Furthermore, in this embodiment, since a flat screw 111 is used in the plasticizing section 110, the injection molding apparatus 10 can be made smaller.

[0030] Furthermore, in this embodiment, the injection molding apparatus 10 is horizontal, and the movable mold 162 moves in a direction intersecting the vertical direction to perform mold clamping. Therefore, the movable mold 162 can be moved with less force than if it were moved vertically upward.

[0031] (A-1) In the first embodiment described above, the injection units 140 are arranged in two rows each in the X and Z directions in the injection section 100. In contrast, the number of injection units 140 and gate openings only needs to be two or more, and can be arbitrarily changed according to the projected area and shape of the cavity 165. Furthermore, the arrangement of the injection units 140 and gate openings can also be arbitrarily changed according to the projected area and shape of the cavity 165.

[0032] Figure 8 is the first diagram showing an example of the arrangement of injection units 140 in relation to a cavity 165. Figure 8 shows the shape of a cavity 165 comprising a first portion P1 having a first volume and a second portion P2 having a smaller volume than the first portion P1, with the first portion P1 and the second portion P2 communicating through a passage P3. In such a cavity 165, if two gate openings are placed in the first portion P1 and one gate opening is placed in the second portion P2, and the injection units 140 are arranged to correspond to these gate openings, then molding material can be injected into the larger first portion P1 from the two injection units 140. As a result, the molding material can be evenly distributed throughout the entire cavity 165.

[0033] Figure 9 is a second diagram showing an example of the arrangement of injection units 140 in relation to the cavity 165. Figure 9 shows a cavity 165 with the same shape as the cavity 165 shown in Figure 8. For example, as shown in Figure 9, even when one injection unit 140 is arranged for the first part P1 with a large volume and the second part P2 with a small volume, according to the above embodiment, injection conditions can be set individually for each injection unit 140. Therefore, for example, by increasing the injection speed or injection pressure of the injection unit 140 that injects into the first part P1 compared to the injection unit 140 that injects into the second part P2, the molding material can be evenly distributed throughout the cavity 165.

[0034] (A-2) In the first embodiment described above, molding material is injected into a single cavity 165 from multiple injection units 140. In contrast, the cavity 165 partitioned by the fixed mold 161 and the movable mold 162 may include, for example, a first cavity communicating with a first gate opening and a second cavity separated from the first cavity and communicating with a second gate opening. In other words, as shown in Figure 10, multiple cavities may be formed in the mold 160, and molding material may be injected into each cavity from separate injection units 140. By doing so, different injection conditions can be applied to each cavity, thereby suppressing quality variations caused by differences in the layout of individual cavities in the mold.

[0035] Furthermore, as shown in Figure 10, if the individual cavities have different shapes from each other, multiple molded parts of different shapes can be molded with a single injection from each injection unit 140. Therefore, so-called family molds can be easily realized.

[0036] Furthermore, as shown in Figure 10, when each cavity is independent and there is only one injection unit 140, the molding material is supplied to each cavity by branching it using a runner, which requires high injection pressure and clamping pressure. However, according to the above embodiment, since the molding material can be injected into each cavity from multiple injection units 140, it becomes easy to distribute the molding material to each cavity even with low injection pressure and clamping pressure.

[0037] Although Figure 10 shows an example where the individual cavities have different shapes, the individual cavities may all have the same shape. In this case, multiple molded parts of the same shape can be molded with a single injection from each injection unit 140.

[0038] (A-3) In the first embodiment described above, each injection unit 140 is capable of injecting molding materials containing fibrous materials such as carbon fibers and glass fibers. For example, by using molding materials containing fibrous materials as the first and second molding materials, and by having the first injection unit 141 and the second injection unit 142 perform injection according to different injection conditions, it is possible to mold a molded product in which the orientation of the fibrous material differs between the part molded by the first molding material and the part molded by the second molding material. For example, by increasing the injection pressure and injection speed of the first injection unit 141 compared to the second injection unit 142, the orientation of the fibrous material in the molding material injected from the first injection unit 141 can be increased compared to the orientation of the fibrous material in the molding material injected from the second injection unit 142. With such a configuration, the orientation of the fibrous material can be made different for each part of the molded product. Also, as shown in Figure 10, if the cavity is separated into multiple parts, it is possible to mold a molded product containing fibrous materials with different orientations for each cavity.

[0039] (A-4) In the above embodiment, the injection molding apparatus 10 moves the movable mold 162 to make the ejector pin 166 protrude relative to the fixed mold 161. Alternatively, as shown in Figure 6, the injection molding apparatus 10 may make the ejector pin 166 protrude from the movable mold 162 by moving the ejector pin 166 itself.

[0040] B. Second Embodiment: Figure 11 shows a schematic configuration of the injection molding apparatus 10b in the second embodiment. One of the differences between the first and second embodiments is that the injection molding apparatus 10 in the first embodiment is a horizontal injection molding apparatus, whereas the injection molding apparatus 10b in the second embodiment is a vertical injection molding apparatus. Another difference is that in the first embodiment, the molded product is completed by one injection from each injection unit 140 into the cavity 165 during one mold clamping cycle, whereas in the second embodiment, multiple mold clamping cycles are performed, and the molded product is completed by injection at each mold clamping cycle.

[0041] The injection molding apparatus 10b is configured with an injection unit 100, a mold 160, and a clamping device 130 arranged vertically from top to bottom. The mold 160 has an upper mold 161b and a lower mold 162b. The upper mold 161b corresponds to the fixed mold 161 in the first embodiment, and the lower mold 162b corresponds to the movable mold 162 in the first embodiment.

[0042] In the second embodiment, the mold clamping device 130 is located below the base 21. Under the control of the control unit 500, the mold clamping device 130 drives a ball screw 184 to move a support column 182 that penetrates the base 21 up and down via a movable plate 183. This causes the injection unit 100 and the upper mold 161b, which are fixed to the support column, to move along the vertical direction, performing mold opening and mold clamping. The lower mold 162b is located on a rotary table 180 fixed to the base 20. The rotary table 180 is rotationally driven by a drive motor 181 under the control of the control unit 500. In other words, in this embodiment, the lower mold 162b is configured to be rotatable.

[0043] Figure 12 is an explanatory diagram showing an example of the molding process in the second embodiment. The right side of Figure 12 schematically shows the convex and concave shapes of the upper mold 161b and lower mold 162b as viewed from above. In step S1, after mold clamping, injection is performed from the corresponding injection unit 140 into two horizontally aligned cavities, and primary molding is carried out. In the cavity on the left in the figure, an upwardly convex first hemisphere is formed, and in the cavity on the right, a downwardly convex second hemisphere is formed. In step S2, the mold is opened, and in step S3, the lower mold 162b is rotated 90° by the rotary table 180. As a result, the first and second hemispheres formed in step S1 face each other. In this state, mold clamping is performed in step S4, and secondary molding is carried out in step S5. In this secondary molding, molding material is supplied to the connection part between the first and second hemispheres, and the first and second hemispheres are joined together. After the mold is opened, a hollow, spherical molded product is completed.

[0044] According to the second embodiment, molding material can be injected into multiple cavities from multiple injection units 140, and furthermore, since the lower mold 162b is configured to be rotatable, it is possible to easily mold hollow bodies and molded products having undercuts. In addition, in the second embodiment, since the lower mold 162b rotates, the entire apparatus can be configured more compactly than structures in which the mold slides, such as DSI (die slide injection molding).

[0045] Figure 12 shows an example of molding a hollow molded product. However, by forming two to four cavities in the mold and injecting from each injection unit each time the lower mold 162b is rotated 90°, it is possible to perform a variety of molding processes, such as two-color molding, two-color two-type molding, three-color molding, and four-color molding, as shown in Figure 13.

[0046] Although Figure 11 shows a vertical injection molding apparatus 10b, the horizontal injection molding apparatus 10 shown in Figure 1 can also be used to perform the aforementioned molding of hollow molded products and multi-color molding by configuring the movable mold 162 to be rotatable.

[0047] C. Other embodiments: (C1) In the above embodiment, some or all of the injection units 140 may be plasticizers equipped with inline screws instead of flat screws 111.

[0048] (C2) In the above embodiment, the injection molding apparatus 10 may employ a cold runner instead of a hot runner. Alternatively, some of the multiple injection units 140 may be equipped with hot runner nozzles.

[0049] D. Other forms: This disclosure is not limited to the embodiments described above, and can be implemented in various configurations without departing from its spirit. For example, the technical features of the embodiments corresponding to the technical features in each of the embodiments described below can be replaced or combined as appropriate in order to solve some or all of the above-described problems, or to achieve some or all of the above-described effects. Furthermore, if a technical feature is not described as essential in this specification, it can be deleted as appropriate.

[0050] (1) According to a first embodiment of the present disclosure, an injection molding apparatus is provided. This injection molding apparatus is The apparatus comprises a fixed mold having a first gate opening and a second gate opening, a movable mold configured to be clamped onto the fixed mold, a first injection unit that injects a first molding material through the first gate opening into a cavity partitioned by the fixed mold and the movable mold, and a second injection unit that injects a second molding material through the second gate opening into the cavity. With this configuration, even when the projected area of ​​the cavity is large, the molding material can be injected from both the first and second injection units, thereby reducing the required injection pressure and clamping pressure. As a result, the injection molding apparatus can be miniaturized.

[0051] (2) In the above embodiment, the second injection unit may inject the second molding material into the cavity from which the first injection unit injects the first molding material. With this embodiment, one molded product can be formed by a single injection from each injection unit.

[0052] (3) In the above embodiment, the cavity may include a first cavity communicating with the first gate opening and a second cavity separated from the first cavity and communicating with the second gate opening. With this embodiment, multiple molded products can be molded by a single injection from each injection unit.

[0053] (4) In the above embodiment, the first cavity and the second cavity may have different shapes from each other. With such an embodiment, multiple molded products of different shapes can be molded in a single injection from each injection unit.

[0054] (5) In the above configuration, the movable mold may be moved in a direction intersecting the vertical direction to perform mold clamping. With this configuration, the movable mold can be moved with less force than when moving it vertically upward.

[0055] (6) In the above configuration, the molded product may be formed by performing an operation once which includes clamping the fixed mold and the movable mold, and injecting into the cavity from the first injection unit and the second injection unit, respectively.

[0056] (7) In the above embodiment, the first molding material and the second molding material may be the same or different materials. With this embodiment, a molded product can be formed using the same or different materials.

[0057] (8) In the above configuration, the first injection unit and the second injection unit may perform injection according to individually set injection conditions. This configuration makes it possible to improve the quality of the molded product.

[0058] (9) In the above embodiment, the first molding material and the second molding material include a fiber material, and the first injection unit and the second injection unit may perform injection according to different injection conditions to form a molded product in which the part molded by the first molding material and the part molded by the second molding material have different orientations of the fiber material. With such an embodiment, the orientation of the fiber material can be made different for each part of the molded product or for each molded product.

[0059] (10) In the above embodiment, an ejector pin may be provided which pushes the molded product out of the movable mold by relatively protruding from the movable mold toward the fixed mold as the mold opens to move the movable mold away from the fixed mold. With such an embodiment, the configuration of the injection molding apparatus can be simplified.

[0060] (11) In the above embodiment, at least one of the first injection unit and the second injection unit may have a plasticizing section comprising a screw that rotates around a rotation axis and has a groove-forming surface on which grooves are formed, and a barrel that has an opposing surface facing the groove-forming surface and has a communication hole on the opposing surface through which the molding material flows out. With such an embodiment, the injection unit can be made smaller. [Explanation of Symbols]

[0061] 10,10b…Injection molding machine, 20,21…Base, 30…Hopper, 100…Injection section, 101…Storage section, 110…Plasticizing section, 111…Flat screw, 112…Barrel, 113…Heater, 114…Nozzle, 116…Communication hole, 118…Drive motor, 120…Injection control mechanism, 121…Injection cylinder, 122…Plunger, 123…Plunger drive section, 124…Check valve, 130…Mold clamping device, 131…Mold drive section, 132…Ball screw, 140…Injection unit, 141…First injection unit, 142…Second injection unit, 143…Third injection unit, 144…Fourth injection unit, 160 ...Mold, 161...Fixed mold, 161b...Upper mold, 162...Movable mold, 162b...Lower mold, 163...Thrust bearing, 164...Extrusion plate, 165...Cavity, 166...Ejector pin, 167...Support plate, 168...Support rod, 169...Spring, 171...First gate opening, 172...Second gate opening, 173...Third gate opening, 174...Fourth gate opening, 180...Rotating table, 181...Drive motor, 182...Support column, 183...Movable plate, 184...Ball screw, 201...Groove forming surface, 202...Groove, 203...Material input port, 204...Protruding part, 205...Center part, 211...Guide groove, 212...Opposite surface, 500...Control unit

Claims

1. A fixed type having a first gate opening and a second gate opening formed therein, A movable mold configured to be clamped to the aforementioned fixed mold, A first injection unit for injecting a first molding material through the first gate opening is provided within the cavity partitioned by the fixed mold and the movable mold. A second injection unit for injecting a second molding material through the second gate opening is provided within the cavity. Equipped with, The aforementioned movable mold moves in a direction intersecting the vertical direction to perform mold clamping. The first injection unit and the second injection unit perform injection in a direction intersecting the vertical direction. At least one of the first injection unit and the second injection unit is The plasticizing section comprises a screw that rotates around a rotation axis and has a groove-forming surface in which grooves are formed, and a barrel that has an opposing surface facing the groove-forming surface and has a communication hole provided on the opposing surface through which the molding material flows out. The cavity includes a first cavity communicating with the first gate opening and a second cavity separated from the first cavity and communicating with the second gate opening. The first cavity and the second cavity have different shapes from each other. By performing a single operation including clamping the fixed mold and the movable mold, and injecting from the first injection unit into the first cavity and injecting from the second injection unit into the second cavity, multiple separate molded parts of different shapes are molded simultaneously. The first injection unit and the second injection unit perform injection according to individually set injection conditions. Injection molding equipment.

2. An injection molding apparatus according to claim 1, An injection molding apparatus in which the first molding material and the second molding material are the same or different materials.

3. An injection molding apparatus according to claim 2, The first molding material and the second molding material include a fiber material. An injection molding apparatus comprising a first injection unit and a second injection unit that perform injection according to different injection conditions, thereby forming molded products in which the part molded with the first molding material and the part molded with the second molding material have different orientations of the fiber material.

4. An injection molding apparatus according to any one of claims 1 to 3, An injection molding apparatus comprising an ejector pin that, in conjunction with mold opening which moves the movable mold away from the fixed mold, pushes out a molded product from the movable mold by relatively protruding from the movable mold toward the fixed mold without moving toward the fixed mold.

5. An injection molding apparatus according to any one of claims 1 to 4, The injection molding apparatus comprises the first injection unit and the second injection unit, each having the plasticizing portion.

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