Resin molding apparatus and resin molded products

Abstract

To provide a resin molding apparatus capable of improving the aesthetic appearance of resin molded products. [Solution] The resin molding apparatus (10) is equipped with a cutting member (50) having a cutting section (52) that can cut the boundary (14) between the main body (40) and the gate filling section (12) by moving back and forth relative to the boundary (14). The end (43) of the main body (40) and the gate filling section (12) are connected to the opening and closing direction (up and down direction) of the mold 30 via the boundary (14). The cutting member (50) can cut the boundary (14) by moving back and forth in a direction intersecting the opening and closing direction of the mold (30).

Description

Technical Field

[0001] The present invention relates to a resin molding apparatus capable of manufacturing a resin molded product, which includes a cutting member capable of cutting molten resin in a mold.

Background Art

[0002] Some resin molded products are formed by filling molten resin into a space formed inside a mold and then curing the molten resin. Inside the mold, a flow path through which the molten resin flows to the space of the molded product is formed.

[0003] This flow path has a sprue into which the molten resin injected from an injection machine first flows, a gate that serves as an inlet to the space of the molded product, and a runner that serves as a path from the sprue to the gate. A technique related to a mold having such a flow path is disclosed in Patent Document 1.

[0004] The mold disclosed in Patent Document 1 includes, in addition to a mold body, a cutting member that cuts the boundary between the resin filled in the gate and the molded product. Since the cutting member is provided in the mold, the gate treatment after taking out the molded product can be omitted.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] By the way, the gate of the mold disclosed in Patent Document 1 is a side gate located on the side of the molded product. In the case of a side gate, since the side surface of the molded product becomes the cutting surface, there is room for improvement from the viewpoint of the appearance of the resin molded product.

[0007] The present invention aims to provide a resin molding apparatus capable of improving the aesthetic appearance of resin molded products. [Means for solving the problem]

[0008] This disclosure provides a mold having a molding space in which a resin molded product can be molded, and a gate which serves as an inlet for molten resin to flow into the molding space, and a mold capable of molding a main body portion which is the molten resin filled in the molding space, and a gate-filling portion which is the molten resin filled in the gate, The cutting member has a cutting portion that moves back and forth relative to the boundary between the end of the main body and the gate filling portion, thereby cutting the boundary, and is capable of forming the main body together with the mold when cutting the boundary. The end portion of the main body and the gate filling portion are connected via the boundary in the opening and closing direction of the mold. A resin molding apparatus is provided in which the cutting member moves back and forth in a direction intersecting the opening and closing direction of the mold, thereby capable of cutting the boundary. [Effects of the Invention]

[0009] The present invention provides a resin molding apparatus capable of improving the aesthetic appearance of resin molded products. [Brief explanation of the drawing]

[0010] [Figure 1] Figure 1A: A plan view of a portion of a resin molded product that has been filled into the mold and integrated with the gate and runner. Figure 1B: A side view taken from the direction of the arrow 1B in Figure 1A. [Figure 2] Figure 2A: Cross-sectional view of a resin molding apparatus. Figure 2B: Cross-sectional view taken along line 2B-2B in Figure 1B. [Figure 3] Figure 3A: This diagram illustrates the state after the cutting member has cut through the molten resin. Figure 3B: This diagram illustrates the state after the resin molded product has been removed from the resin molding apparatus. [Figure 4] This is a diagram illustrating the operation of the embodiment. [Modes for carrying out the invention]

[0011] An example will be described based on the attached diagram. Note that the example described herein is not intended to particularly limit the present invention. In the diagram, Fr indicates front, Rr indicates rear, Le indicates left, Ri indicates right, Up indicates top, and Dn indicates bottom.

[0012] <Examples> Refer to Figure 3B. It shows the end portion 23 of the resin molded product 20 that can be attached to a vehicle. Hereafter, the direction in which the surface 21 (the side easily visible from the outside, the design side) of the resin molded product 20 is facing will be referred to as the front side (top), and the direction in which the back surface 22 is facing will be referred to as the back side (bottom). The end portion 23 has a bent shape that is folded from the front side to the back side. In other words, it can be said that only the end portion 23 is set to be thicker.

[0013] In detail, this end portion 23 has an end surface 21, an end back surface 25, a side surface 26, and an opposite surface 27 opposite to the side surface 26. The side surface 26 has a slightly curved shape that bulges laterally. Of the side surface 26, the top 26a of the side surface 26 is defined as the boundary 14, with the front side being the first side portion 26b and the back side being the second side portion 26c. The shape of the resin molded product 20 and the shape of the end portion 23 are not limited to those shown in the embodiment. Furthermore, the application of the resin molded product 20 is not limited.

[0014] Refer to Figures 2A and 2B. The resin molding apparatus 10 for manufacturing the resin molded product 20 can be attached to an injection molding machine (not shown).

[0015] The resin molding apparatus 10 includes a mold 30 having a molding space 30a capable of molding a resin molded product 20. The mold 30 comprises a fixed mold 32 and a movable mold 31 that is movable relative to the fixed mold 32. The direction of movement of the movable mold 31 is the opening and closing direction of the mold 30. The fixed mold 32 is located on the back side, and the movable mold 31 is located on the front side.

[0016] The fixed mold 32 is formed with a gate 33 that serves as an inlet for the molten resin M to flow into the molding space 30a, a sprue (not shown) into which the molten resin M injected from the injector of the injection molding machine first flows, and a runner 34 that serves as a path from the sprue to the gate 33.

[0017] Refer to FIGS. 1A, 1B, 2A, and 2B. The molten resin M filled in the mold 30 fills the molding space 30a and has a main body portion 40 having the same shape as the resin molded product 20, a gate filling portion 12 filled in the gate 33, and a runner filling portion 13 filled in the runner 34.

[0018] The end portion 43 of the main body portion 40 and the gate filling portion 12 are continuous in the opening and closing direction (vertical direction) of the mold 30 via a boundary 14 between the end portion 43 and the gate filling portion 12.

[0019] The surface 44 of the main body portion 40 and a part of the side surface 46 (the first side portion 46b on the front side of the top portion 46a in the side surface 46) are molded by the movable mold 31. The back surface 42 of the main body portion 40 and the opposite surface of the end portion 43 are molded by the fixed mold 32.

[0020] The resin molding apparatus 10 includes a cutting member 50 capable of cutting the molten resin M before curing filled in the mold 30. The cutting member 50 is a plate-shaped metal member slidable with respect to the mold 30 (see FIGS. 1A and 1B), retracts during the filling of the molten resin M (see FIG. 2B), and is capable of advancing and retreating toward the main body portion 40 during the cutting of the molten resin M (see FIG. 3A). The cutting member 50 can advance and retreat in a direction intersecting the opening and closing direction of the mold 30 (a direction other than the vertical direction, for example, a direction substantially orthogonal to the opening and closing direction (left and right direction)).

[0021] A drive device (not shown) for advancing and retreating the cutting member 50 can employ, for example, one provided with a hydraulic cylinder for advancement and a compression coil spring for retreat. In addition, as long as the cutting member 50 can advance and retreat, such as an air cylinder, an electric motor, or manual operation, the configuration is not limited. A drive device for a slide core corresponding to the undercut shape of the resin molded product 20 may also be employed.

[0022] The tip portion 51 of the cutting member 50 has a cutting portion 52 that cuts the boundary 14 between the main body portion 40 and the gate filling portion 12, a first extending portion 53 that extends from the rear end portion 52b of the cutting portion 52 toward the front side (upper side), and a planar first sliding portion 54 that extends from the first extending portion 53 in the retreat direction and is slidable with respect to the slidable surface portion 31a of the movable mold 31.

[0023] Refer to FIG. 2A. The first sliding portion 54 of the cutting member 50 and the slidable surface portion 31a of the movable mold 31 are located in the same plane as the mating surface 30b (parting line) of the fixed mold 32 and the movable mold 31.

[0024] Refer to FIG. 3A. The cutting portion 52 is a planar portion facing substantially the front side (upper side) with reference to the front and back directions of the main body portion 40, and forms the back surface 45 of the end portion 43 of the main body portion 40 during cutting. The back surface 45 can also be said to be a cut surface. The cutting portion 52 may be slightly downward sloping toward the front (tilting toward the back side as it advances).

[0025] Refer to FIGS. 2B and 3A. The first extending portion 53 extends obliquely from the rear end portion 52b of the cutting portion 52 toward the front rear (obliquely upper right), and pushes a part m of the molten resin M located on the side of the main body portion 40 when the cutting portion 52 cuts the boundary 14.

[0026] The first extending portion 53 forms a part of the side surface 46 of the end portion 43 (the second side portion 46c behind the top portion 46a in the side surface 46) during cutting. During this forming, the first extending portion 53 is continuous so as to have no step with the movable mold 31. Note that the first extending portion 53 may extend only to the front side (vertically upward). The cutting portion 52 and the first sliding portion 54 may be located in the same plane without providing the first extending portion 53.

[0027] The cutting member 50 further includes a second extension 55 extending backward (downward) from the tip 52a of the cutting portion 52, and a planar second sliding portion 56 extending backward from the second extension 55 and slidable relative to the sliding surface 32a of the fixed type 32.

[0028] The second extension 55 extends diagonally backward (diagonally downward to the right) from the tip 52a of the cutting portion 52. That is, the cutting member 50 has a pointed shape with the tip 52a of the cutting portion 52 as its apex. The second extension 55 may also extend only on the back side (straight down).

[0029] Refer to Figures 2A and 2B. In the first resin molding apparatus 10, A mold 30 has a molding space 30a into which a resin molded product 20 can be molded, and a gate 33 which is an inlet into which molten resin M flows into the molding space 30a, and a mold 30 that can mold a main body 40 which is molten resin M filled in the molding space 30a, and a gate filling part 12 which is molten resin M filled in the gate 33, The cutting member 50 has a cutting portion 52 that moves back and forth relative to the boundary 14 between the end portion 43 of the main body portion 40 and the gate filling portion 12, thereby cutting the boundary 14, and is capable of forming the main body portion 40 together with the mold 30 when cutting the boundary 14. The end portion 43 of the main body portion 40 and the gate filling portion 12 are connected to the mold 30 in the opening and closing direction (vertical direction) via the boundary 14. The cutting member 50 can move back and forth in a direction intersecting the opening and closing direction of the mold 30, thereby cutting the boundary 14.

[0030] Refer to Figure 4. With the above configuration, the cut surface 45 of the end portion 43 will face the back side. Since the cut surface 45 (back surface 45) is difficult to see, a resin molding apparatus 10 can be provided that can improve the aesthetic appearance of the resin molded product 20.

[0031] Refer to Figure 2B. Secondly, in the first resin molding apparatus 10, the tip 52a of the cutting section 52 is pointed. This reduces the load on the cutting member 50 during cutting. There are fewer burrs adhering to the main body 40. The fixed mold 32 may also be pointed, but pointing the cutting member 50 improves the maintainability of the resin molding apparatus 10.

[0032] Thirdly, the first or second resin molding apparatus 10 has a first extension portion 53 that extends from the rear end portion 52b of the cutting portion 52 in the direction in which the thickness of the cutting member 50 increases (towards the front side). When the boundary 14 is cut by the cutting member 50, the first extension portion 53 can push a portion m of the molten resin M toward the main body portion 40, so that the top portion 26a of the side surface 26 of the resin molded product 20 does not become stepped, and the aesthetic appearance of the resin molded product 20 can be further enhanced.

[0033] Fourth, the resin molded product 20 can be molded by using any of the first to third resin molding apparatus 10.

[0034] Refer to Figure 2A. The first sliding portion 54 of the cutting member 50 is located on the same plane as the mold mating surface 30b (parting line). Refer to Figure 3B. When the mold 30 is open, the first sliding portion 54 of the cutting member 50 is exposed. This makes it easy to inspect the cutting member 50 and replace it when it wears out. Furthermore, the length of the cutting member 50 in the forward and backward direction can be adjusted as needed. [Explanation of Symbols]

[0035] 10…Resin molding equipment 12...Gate filling section 14...boundary 20…Resin molded product 30…Mold 30a…Molding space 33…Gate 40...Main body 41…Surface of the main body 42...Back of the main unit 43...End of the main body 44… Surface of the end 45…Cut surface 50…Cutting piece 52…cutting section 52a... Rear end of the cut section 52b...Tip of the cut section 53...First extension part M...Molten resin

Claims

1. A mold having a molding space in which a resin molded product can be molded, and a gate which serves as an inlet for molten resin to flow into the molding space, wherein a main body portion is the molten resin filled in the molding space, and a gate-filling portion is the molten resin filled in the gate, The cutting member has a cutting portion that moves back and forth relative to the boundary between the end of the main body and the gate filling portion, thereby cutting the boundary, and is capable of forming the main body together with the mold when cutting the boundary. The end portion of the main body and the gate filling portion are connected via the boundary in the opening and closing direction of the mold. The cutting member is a resin molding apparatus capable of cutting the boundary by moving back and forth in a direction intersecting the opening and closing direction of the mold.

2. The resin molding apparatus according to claim 1, wherein the tip of the cut portion is pointed.

3. The resin molding apparatus according to claim 1, further comprising a first extension portion extending from the rear end of the cut portion in a direction that increases the thickness of the cut member.

4. A resin molded product formed using the resin molding apparatus described in any one of claims 1 to 3.

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