Injection molding equipment

Abstract

To provide an injection molding machine with high mass production efficiency.SOLUTION: An injection molding machine has: multiple injection nozzles P1, P2 that inject different types of resin material; a plate-shaped runner plate 3 that has multiple sprues 22, 23 corresponding to each of the injection nozzles P1, P2; a plate-shaped cavity plate 4 that is arranged to be able to be separated from and attached to the runner plate 3 and has a runner forming surface 32, a cavity surface 34, and a gate 36; and a core 5 that is arranged to be able to be separated from and attached to the cavity plate 4 and is arranged opposite to the cavity surface 34. The runner plate 3 includes a plate-shaped switching plate 6 that includes through holes 51 corresponding to the sprues 22, 23 and selectively opens and closes the sprues 22, 23 by moving the through holes 51.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an injection molding apparatus. [Background technology]

[0002] Injection molding machines are known as a technique for molding resins such as plastics. The injection molding machine disclosed in Patent Document 1 includes a plunger that moves back and forth within an injection barrel having a single molten resin injection nozzle to inject and measure the molten resin, and a drive device that moves the plunger back and forth. The injection molding machine disclosed in Patent Document 1 also includes a plurality of first heated barrels arranged around the injection barrel, each equipped with a hopper at its resin material supply port, and screws rotatably inserted into the first heated barrels. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 8-281736 Summary of the Invention [Problem to be solved by the invention]

[0004] In the injection molding machine of Patent Document 1, for example, when changing the color or material type of the resin molded product, the inside of the machine must be cleaned with a large amount of detergent each time. This makes the cleaning work complicated, and there is room for improvement in terms of mass production efficiency.

[0005] Therefore, an object of the present invention is to provide an injection molding apparatus that has high mass production efficiency. [Means for solving the problem]

[0006] In order to solve the above-mentioned problems, the present invention provides an injection molding apparatus for molding a resin molded product, comprising: a plate-shaped runner plate having a plurality of injection nozzles each for injecting a different resin material; a plate-shaped cavity plate arranged so as to be removably attached to the runner plate, the plate-shaped cavity plate having a runner molding surface which is filled with the resin material to form a runner; a cavity surface which forms the resin molded product; and a core arranged so as to be removably attached to the cavity plate and disposed opposite the cavity surface, the runner plate having through holes corresponding to each of the sprues and which selectively opens and closes the sprues by moving the through holes.

[0007] According to the present invention, by separating the runner plate from the cavity plate, the cooled and solidified runner can be easily removed. Furthermore, since the sprue, runner molding surface, and gate are connected, the cooled and solidified liner remaining in each area can be easily removed. This eliminates the need to clean the sprue, runner molding surface, and gate, or simplifies cleaning. Furthermore, the provision of a switching plate makes it easy to change the color or material of the resin.

[0008] Preferably, the switching plate rotates or slides. According to the present invention, the switching operation can be easily performed.

[0009] It is also preferable that a fixed mounting plate be provided between the runner plate and the injection nozzle, and that the fixed mounting plate have a plurality of nozzle arrangement sections in which the injection nozzles are arranged, and a plurality of communication holes that connect each of the nozzle arrangement sections to each of the sprues.

[0010] According to the present invention, since the fixed mounting plate is provided with the nozzle placement portion and the communication hole, the resin injected from the injection nozzle can be smoothly guided to the through hole. [Effects of the Invention]

[0011] According to the present invention, an injection molding apparatus with high mass production efficiency can be provided. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a vertical cross-sectional view of an injection molding apparatus according to an embodiment of the present invention (before filling with resin material). [Figure 2] 1 is a vertical cross-sectional view of an injection molding apparatus according to an embodiment of the present invention (after filling with resin material). [Figure 3] FIG. 2 is a plan view of a switching plate of the injection molding apparatus according to the embodiment of the present invention. [Figure 4] FIG. 2 is a cross-sectional view of the injection molding apparatus according to the embodiment of the present invention after demolding. [Figure 5] FIG. 2 is a vertical cross-sectional view of the injection molding apparatus according to one embodiment of the present invention (after a color change process). [Figure 6] 4 is a plan view of a switching plate of the injection molding apparatus according to one embodiment of the present invention (after a color change process). FIG. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a vertical cross-sectional view of an injection molding apparatus according to this embodiment (before resin material is filled). This injection molding apparatus 1 is an apparatus that molds molten resin material to produce a resin molded product 101 (see FIG. 4). Injection molding apparatus 1 is equipped with, from the right in FIG. 1, injection nozzles P1 and P2, a fixed mounting plate 2, a runner plate 3, a cavity plate 4, and a core 5. Note that up and down and left and right in the explanation follow the state in FIG. 1. These directions are used for convenience of explanation and do not limit the directions of the present invention.

[0014] The injection nozzles P1 and P2 are nozzles that inject resin materials of different colors or materials. In this embodiment, the injection nozzles P1 and P2 are configured to inject resin materials arbitrarily.

[0015] The fixed mounting plate 2 is a plate-like member disposed between the injection nozzles P1, P2 and the runner plate 3. The fixed mounting plate 2 is equipped with communication holes 11, 12 that communicate in the left-right direction, and nozzle arrangement portions 14, 15. The communication hole 11 is provided at a position continuous with the opening of the injection nozzle P1. The communication hole 12 is provided at a position continuous with the opening of the injection nozzle P2. The nozzle arrangement portion 14 is continuous with the communication hole 11 and is recessed to match the shape of the tip of the injection nozzle P1. Similarly, the nozzle arrangement portion 15 is continuous with the communication hole 12 and is recessed to match the shape of the tip of the injection nozzle P2. The injection nozzles P1, P2 are disposed in contact with the nozzle arrangement portions 14, 15, respectively.

[0016] The communicating holes 11, 12 may be provided integrally with the fixed mounting plate 2, or may be formed as separate members as in this embodiment. This allows the member having the communicating holes 11, 12 to be removed from the fixed mounting plate 2 for easy maintenance. The communicating holes 11, 12 may be holes of a fixed size, or may gradually increase in diameter in the direction of flow of the resin material as in this embodiment.

[0017] The runner plate 3 is a plate-like member disposed between the fixed mounting plate 2 and the cavity plate 4. The opposing surface 27 on the right side of the runner plate 3 is in contact with the opposing surface 18 on the left side of the fixed mounting plate 2. The runner plate 3 can be in surface contact with the fixed mounting plate 2 or can be separated from it.

[0018] The runner plate 3 includes a switching plate 6 disposed in a recess 21, and sprues 22 and 23. The recess 21 includes a cylindrical hollow portion that opens toward the fixed mounting plate 2. The switching plate 6 is disk-shaped and rotatably disposed in the recess 21. The switching plate 6 is formed with a through hole 51 that penetrates in the plate thickness direction. The through hole 51 is provided at a position that communicates with the communication holes 11 and 12 when the switching plate 6 rotates. The through hole 51 may be a hole of a constant size, or may gradually increase in diameter in the flow direction of the resin material, as in this embodiment.

[0019] The switching plate 6 is connected to an actuator 8 via a rotation shaft 7 connected to the center of the switching plate 6. The actuator 8 is formed so as to be rotatably driven based on a control signal from a control unit (not shown).

[0020] The sprue 22 is formed adjacent to the switching plate 6 at a position corresponding to the communication hole 11. The sprue 22 penetrates from the communication hole 11 side to the opposing surface 28. In the state shown in FIG. 1, the sprue 22 communicates with the through hole 51.

[0021] The sprue 23 is formed adjacent to the switching plate 6 at a position corresponding to the communicating hole 12. The sprue 23 penetrates from the communicating hole 12 side to the opposing surface 28. In the state shown in FIG. 1 , the sprue 23 is covered by the switching plate 6.

[0022] The sprues 22, 23 may be provided integrally with the runner plate 3, or may be formed as separate members as in this embodiment. This allows the members having the sprues 22, 23 to be removed from the runner plate 3 for easy maintenance. The sprues 22, 23 may be holes of a fixed size, or may be gradually enlarged in diameter in the direction of flow of the resin material as in this embodiment.

[0023] The cavity plate 4 is a plate-like member disposed between the runner plate 3 and the core 5. A right opposing surface 31 of the cavity plate 4 is in contact with a left opposing surface 28 of the runner plate 3. The cavity plate 4 is capable of being in surface contact with the runner plate 3 or being separated therefrom.

[0024] The cavity plate 4 has a runner molding surface 32, a cavity surface 34, and a gate 36. The runner molding surface 32 is a portion where a runner 111 (see FIG. 4) described later is molded, and is open to the runner plate 3 side and has a concave shape. The cavity surface 34 is a portion where a resin molded product 101 (see FIG. 4) described later is molded, and is open to the core 5 side and has a concave shape.

[0025] The gate 36 is a hole that communicates from the runner molding surface 32 to the cavity surface 34. The gate 36 is formed so that its diameter gradually decreases in the direction in which the resin material flows. The gate 36 is a portion that unifies the paths of the resin material injected from the injection nozzle P1 (or injection nozzle P2).

[0026] The core 5 is a plate-like member disposed on the left side of the cavity plate 4. The right facing surface 41 of the core 5 is in contact with the left facing surface 35 of the cavity plate 4. The core 5 is capable of being in surface contact with or separated from the cavity plate 4. A core molding surface 55 is formed on the surface of the core 5 facing the cavity plate 4. The core molding surface 55 is formed to protrude toward the cavity surface 34 so as to correspond to the cavity surface 34. The cavity surface 34 and the core molding surface 55 form a cavity in which the resin molded product 101 is molded.

[0027] Next, a resin molding method using the injection molding apparatus 1 will be described. Here, an example will be shown in which a resin molded product 101 of color A is first formed, and then a resin molded product of color B is formed. The resin molding method of this embodiment includes a mold clamping process, an injection process, a solidification process, a demolding process, a removal process, a mold clamping process (color change process), an injection process, a solidification process, a demolding process, and a removal process.

[0028] In the mold clamping process, the fixed mounting plate 2, runner plate 3, cavity plate 4, and core 5 are brought into contact with each other and clamped together, as shown in Fig. 1. At this time, the through-hole 51 is positioned so as to communicate with the communication hole 11 and the sprue 22, as shown in Fig. 1 (also see Fig. 3).

[0029] In the injection process, the molten resin material Z1 of color A is injected from the injection nozzle P1, thereby filling each space in the injection molding device 1 with the resin material Z1 of color A, as shown in FIG.

[0030] In the solidification step, the resin material is cooled for a predetermined period of time to solidify. In the demolding step, as shown in FIG. 4, the runner plate 3, the cavity plate 4, and the core 5 are separated from each other and demolded.

[0031] 4, the resin molded product 101 and the runner 111 are removed. By removing the runner 111 from the resin molded product 101, the resin molded product 101 of color A can be obtained. The runner 111 includes a runner main body 112, a first runner limb 113, a second runner limb 114, and a third runner limb 115.

[0032] The runner main body 112 is a portion molded by the runner molding surface 32 and the opposing surface 28. The first runner limb 113 is a portion molded by the sprue 22, the through hole 51, and the communicating hole 11. The second runner limb 114 is a portion molded by the sprue 23. The third runner limb 115 is a portion molded by the gate 36.

[0033] In the mold clamping process (color change process), as shown in Figure 5, the fixed mounting plate 2, runner plate 3, cavity plate 4, and core 5 are again brought into contact with each other and the mold is clamped. At this time, the actuator 8 is driven to position the through-hole 51 (see also Figure 6) so that it communicates with the communication hole 12 and the sprue 23. As a result, the flow path on the injection nozzle P1 side is blocked by the switching plate 6.

[0034] In the injection process, molten B resin material Z2 is injected from the injection nozzle P2. As a result, the resin material Z2 fills each space in the injection molding device 1, as shown in Fig. 5. The subsequent solidification process, demolding process, and removal process are the same as those described above, and therefore their explanations are omitted. As a result, a B resin molded product is obtained.

[0035] The injection molding apparatus 1 (injection molding method) according to the present embodiment described above can improve mass production efficiency when changing the color of a resin molded product. Specifically, by separating the runner plate 3 from the cavity plate 4, the runner 111 that has cooled and solidified can be easily removed. Furthermore, because the sprues 22 and 23, the runner molding surface 32, and the gate 36 are connected, the runner 111 that has cooled and solidified and remained in each location can be easily removed. This eliminates or simplifies the cleaning of the sprues 22 and 23, the runner molding surface 32, and the gate 36. This shortens the manufacturing cycle compared to conventional methods, improving mass productivity.

[0036] Furthermore, according to this embodiment, since the switching plate 6 is provided, the switching operation (opening and closing operation) of the injection nozzles P1 and P2 can be easily performed. In other words, color change can be performed simply by removing the runner 111 and switching the switching plate 6. Furthermore, since the rotating shaft 7 and the actuator 8 are provided, the rotation of the switching plate 6 can be easily controlled. Furthermore, since it is only necessary to rotate the switching plate 6, the structure and control can be simplified.

[0037] Furthermore, since the fixed mounting plate 2 is provided with the nozzle arrangement portions 14, 15 and the communication holes 11, 12, the resin material injected from the injection nozzles P1, P2 can be smoothly guided to the through-hole 51. Although the fixed mounting plate 2 may be omitted, providing the fixed mounting plate 2 makes it possible to avoid contact between the rotating switching plate 6 and the injection nozzles P1, P2, thereby preventing wear and damage to the injection nozzles P1, P2. Furthermore, since the fixed mounting plate 2 is provided with the nozzle arrangement portions 14, 15 that are recessed to follow the shape of the tips of the injection nozzles P1, P2, the injection nozzles P1, P2 can be held stably.

[0038] Although the embodiments of the present invention have been described above, design changes are possible within the scope of the present invention. For example, although the switching plate 6 rotates in this embodiment, it may also be slid linearly to move the position of the through-hole 51. Also, although the number of injection nozzles is two in this embodiment, it may be three or more. Accordingly, the number of communication holes and sprues may also be increased appropriately.

[0039] Also, the fixed mounting plate 2 may be omitted so that the injection nozzle directly faces the through-hole 51. Also, in this embodiment, the fixed mounting plate 2, runner plate 3, cavity plate 4, and core 5 have the same vertical height, making the overall compact, but they may be different. Also, in this embodiment, the resin materials are illustrated as being different colors, but they may be of different materials. [Explanation of symbols]

[0040] 1 Injection molding equipment 2 Fixed mounting plates 3 Runner Plate 4 Cavity Plate 5 cores 6 Switching plate 11,12 Communication hole 22,23 sprue 32 Runner molding surface 34 Cavity surface Gate 36 51 Through hole 101 Resin molded products P1 injection nozzle P2 injection nozzle

Claims

1. An injection molding apparatus for molding a resin molded product, a plurality of injection nozzles each for injecting a different resin material; a plate-shaped runner plate having a plurality of sprues corresponding to the respective injection nozzles; a plate-like cavity plate, which is disposed so as to be removably attached to the runner plate, and which has a runner molding surface which fills the resin material to form a runner, a cavity surface which forms a resin molded product, and a gate which penetrates from the runner molding surface to the cavity surface and which unifies paths for the resin material injected from each of the injection nozzles; a core that is disposed so as to be removably attached to the cavity plate and that is disposed opposite the cavity surface, an injection molding apparatus, characterized in that the runner plate includes a plate-shaped switching plate having through holes corresponding to each of the sprues and selectively opening and closing the sprues by moving the through holes.

2. 2. The injection molding apparatus according to claim 1, wherein the switching plate rotates or slides.

3. a fixed mounting plate between the runner plate and the injection nozzle; 3. The injection molding apparatus according to claim 1, wherein the fixed mounting plate has a plurality of nozzle arrangement sections in which the injection nozzles are arranged, and a plurality of communication holes that communicate from each of the nozzle arrangement sections to each of the sprues.

Images