Resin molded products, molding equipment, molding methods and molds

Abstract

To provide a resin molded product which is molded in a shortened time.SOLUTION: The resin molded product is molded from plural resins and includes a runner with a joint at which a first resin and a second resin meet. The joint includes a first joint molded from the first resin and a second joint molded from the second resin, and the first joint is formed in a concave shape including a wall coming in contact with part of the second joint.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a resin molded product, a molding device, a molding method, and a mold. [Background technology]

[0002] For example, in a multicolor molded product formed using multiple resins, different resins may be connected to each other at the runner portion. Patent Document 1 describes a molding device for molding such a multicolor molded product. In the molding device described in Patent Document 1, a partition member is provided in the runner groove of the mold. The partition member blocks the flow of the primary molding resin from one side of the runner groove. After the primary molding resin hardens, a secondary molding resin different from the primary molding resin flows from the other side of the runner groove. At this time, the flow pressure of the secondary molding resin pushes the partition member down out of the runner groove, causing the secondary molding resin to flow into the position where the partition member was located and fuse with the primary molding resin. This results in the formation of a multicolor molded product consisting of the primary molding resin and the secondary molding resin of a different color from the primary molding resin. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 8-258082 Summary of the Invention [Problem to be solved by the invention]

[0004] However, with the molding device described in Patent Document 1, if the secondary molding resin reaches the partition member before the primary molding resin has hardened, the primary molding resin and the secondary molding resin may mix at the location where the partition member was located. As a result, the injection time must be adjusted, for example by delaying the injection of the secondary molding resin, so that the secondary molding resin reaches the partition member after the primary molding resin has hardened, which takes a long time for molding.

[0005] The present invention provides a resin molded product that requires less time for molding. [Means for solving the problem]

[0006] According to one aspect of the present invention, for example, there is provided a resin molded product molded from a plurality of resins and including a joint portion where a first resin and a second resin join on a runner, the joint portion including a first joint portion molded from the first resin and a second joint portion molded from the second resin, and the first joint portion formed in a concave shape having a wall portion that contacts a portion of the second joint portion. According to the present invention, there is also provided a resin molded product molded from a plurality of resins and including a joint portion where a first resin and a second resin join in a runner, the joint portion including a first joint portion molded from the first resin and a second joint portion molded from the second resin, the first joint portion being formed to have a wall portion in contact with a part of the second joint portion, the wall portion being thinner than the runner, and the first joint portion being thinner than the runner, At least a part of the inner circumferential surface of the wall portion is an inclined surface that inclines outward from the wall portion toward the end of the wall portion. . [Effects of the Invention]

[0007] According to the present invention, it is possible to provide a resin molded product in which the molding time is shortened. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a cross-sectional view of a molding device according to an embodiment of the present invention. [Figure 2] FIG. [Figure 3] 1A is a perspective view of a main part of a runner groove, FIG. 1B is a perspective view of a main part of a runner groove showing a state in which a partition member is retracted, and FIG. 1C is an enlarged perspective view of a partition member in the runner groove. [Figure 4] 1A and 1B are a perspective view and a cross-sectional view, respectively, of a runner of a resin molded product according to a first embodiment of the present invention. [Figure 5] (A) is a perspective view of the runner of the resin molded product in Figure 4, and (B) is a cross-sectional view. [Figure 6] (A) is a cross-sectional view of the mold after completion of injection of the first resin, and (B) is a cross-sectional view of the mold after completion of injection of the second resin. [Figure 7] FIG. 6 is a cross-sectional view of a main portion of a runner groove according to a second embodiment of the present invention. [Figure 8] (A) is a cross-sectional view of the mold after completion of injection of the first resin, and (B) is a cross-sectional view of the mold after completion of injection of the second resin. [Figure 9] 10A and 10B are a perspective view and a cross-sectional view, respectively, of a runner of a resin molded product according to a second embodiment of the present invention. [Figure 10] (A) is a perspective view of the runner of the resin molded product in Figure 9, and (B) is a cross-sectional view. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, exemplary embodiments of the present invention will be described with reference to the drawings. Note that the same reference numerals in each drawing indicate the same elements. Furthermore, in each drawing, the up, down, left, and right directions relative to the paper surface will be used in the description of the present embodiment as the up, down, left, and right directions of the device in this embodiment. Note that, although resin materials of different colors are exemplified as molding materials in the embodiments described below, the present invention is not limited to this, and can also be applied to molding materials of, for example, different materials (thermoplastic resins such as polystyrene, polyethylene, and ABS, thermosetting resins, metals, etc.), resins of different transparencies, etc.

[0010] First Embodiment Numeral 1 denotes a molding device, which includes a known injection device (not shown), and is composed of a movable mold body 2 attached to the movable side of the injection device, and a fixed mold body 3 attached to the fixed side of the injection device. Figure 1 is a cross-sectional view of the entire molding device 1 in which the movable mold body 2 is joined to the fixed mold body 3.

[0011] The movable mold body 2 is made up of a male mold mounting plate 6 to which a male mold (movable mold) 5 is attached, a fixed base 7 to which the male mold mounting plate 6 is fixed, a movable side mounting plate 9 to be attached to the injection device, and spacers 10 provided on both sides between the fixed base 7 and the movable side mounting plate 9. Reference numerals 11 and 12 denote recesses for connecting injection nozzles for injecting molding resin materials of different colors via runner grooves 15 and 16 into a molding mold 18 formed between the male mold 5 and a female mold 51, which will be described later.

[0012] A cavity 19 is formed in the fixed base 7, and a push-out plate 20 is movably provided within this cavity 19. A plurality of knock-out pins 21 are implanted in this push-out plate 20. Each knock-out pin 21 penetrates the male mold mounting plate 6, the male mold 5, etc., with its tip extending into the molding mold 18 and the runner grooves 15, 16, and is configured to push out a multicolor molded product 24 molded within the molding mold 18 and a multicolor runner R molded in the runner grooves 15, 16, as described below. The push-out plate 20 is fixed to a pressing shaft 25 inserted through holes 22, 23 formed approximately in the center of the fixed base 7 and the movable mounting plate 9.

[0013] The fixed base 7 is formed with a mounting hole 29 that is open on the side facing the fixed mold body 3, and the rear portion of the partition member 30 is slidably provided within this mounting hole 29. Coil springs 31a and 31b are provided within this mounting hole 29 to bias the rear ends of the partition members 30a and 30b toward the fixed mold body 3. A flange 32 may be formed at the rear portion of the partition member 30a, and this flange 32 may be engaged with a step 33 formed in the mounting hole 29 to restrict the range of movement of the partition member 30a. The partition members 30a and 30b have their tips pressed against a female mold (fixed mold) 51 (described later) so as to divide the inside of the runner groove 16 and the forming mold 18 into at least two sections.

[0014] The fixed mold body 3 comprises a fixed-side mounting plate 50 that is attached to an injection device (not shown), a female mold mounting plate 52 to which a female mold 51 is attached, and spacers 53 provided on both sides of the plate and the female mold 51. Reference numeral 55 denotes an injection nozzle connecting recess formed in the fixed-side mounting plate 50. The tip of the injection nozzle attached to this connecting recess 55 is connected to a sprue hole 56 formed in the female mold mounting plate 52 and the female mold 51. This sprue hole 56 is formed to communicate with the runner grooves 15, 16.

[0015] <Partition member 30a> The partition member 30a will be described in detail with reference to Figures 1 and 2. The partition member 30a is provided on the movable mold body 2 (or fixed mold body 3) so as to be able to enter and exit the runner groove 16 so as to separate the inside of the runner groove 16. The partition member 30a is biased in a direction in which it moves out into the runner groove 16 by an elastic member 31a.

[0016] 2, the cross-sectional shape of the partition member 30a that separates the runner groove 16 is not particularly limited, but in this embodiment it is formed in a round shaft shape. A round shaft shape makes it easy to process a mold that accommodates the partition member 30a, and the partition member 30a can be manufactured by processing a conventional ejector pin. Note that the partition member 30a is not limited to a round shaft shape and may be formed in a rectangular column shape.

[0017] A small diameter portion 35 is formed at the tip of the partition member 30a, and the tip of this small diameter portion 35 is biased by a coil spring 31a, protruding into the runner groove 16 and pressed against the female die 51. One surface 36 of this small diameter portion 35 (the surface on the far side in FIG. 2, the regulating surface) is approximately perpendicular to the direction in which the molding resin material flows through the runner groove 16, which will be described later. In addition, the other surface 37 (the surface on the near side in FIG. 2) is formed with a stepped recess 40 that opens up to an upper end surface 39 of the partition member 30a.

[0018] There are no particular limitations on the shape of the stepped recess 40. For example, the stepped recess 40 shown in Fig. 2 includes a recess 40a that forms a hemispherical depression formed in the center of the upper end surface of a circular cross section, and a notch 40b that is cut out from this hemispherical recess toward the other surface 37.

[0019] FIG. 3A shows a perspective view of the male mold 5 with the partition member 30a accommodated in the runner groove 16. A pair of diaphragm pins 16a are arranged in the runner groove 16, sandwiching the partition member 30a. The diaphragm pins 16a suppress the force of the flowing resin and prevent it from overflowing the partition member 30a and flowing to the opposite side. A protrusion 16b is arranged adjacent to the partition member 30a in the runner groove 16. The protrusion 16b protrudes into the runner groove 16 on one surface (restriction surface) 36 of the partition member 30a and forms a recessed portion 17a having a wall portion 17a1 that covers a portion of the partition member 30a in the runner R (described later). FIG. 3B shows the partition member 30a accommodated in the runner groove 16 of the male mold 5 in a retracted position. FIG. 3C shows an enlarged perspective view of the partition member 30a. 3(A), 3(B), and 3(C) show a state in which the runner groove 16 is not filled with resin.

[0020] <Runner R> The runner R in this embodiment will be described with reference to FIGS. 4 and 5. FIGS. 4A and 5A are perspective views of the runner R constituting a part of the resin molded product according to the first embodiment of the present invention. FIG. 4B is a cross-sectional view taken along line IV-IV in FIG. 4A. FIG. 5B is a cross-sectional view taken along line VV in FIG. 5A. As shown in FIG. 4A, the runner R includes a first runner portion A1 formed of a first resin A, a second runner portion B1 formed of a second resin B, and a joint portion 17 where the first resin A and the second resin B join. Thus, the runner R forms a part of a resin molded product molded from multiple resins. The first runner portion A1 and the second runner portion B1 are disposed on opposite sides of the joint portion 17, and include openings A2 and B2 formed by drawing pins 16a, respectively.

[0021] The joint portion 17 includes a first joint portion 17a molded from a first resin A and a second joint portion 17b molded from a second resin B. The second joint portion 17b is molded in the runner groove 16 by retracting the partition member 30a (described later), and therefore includes a bottom portion onto which the shape of the stepped recess 40 of the partition member 30a is transferred, and a cylindrical portion having the same diameter as the small diameter portion 35 of the partition member 30a.

[0022] On the other hand, the first joint portion 17a is formed in a concave shape having a wall portion 17a1 that contacts a part of the side surface of the cylindrical portion of the second joint portion 17b and a bottom portion (deep portion) 17a2. In other words, the concave shape is composed of the bottom portion 17a2 and the wall portion 17a1 that stands around the bottom portion 17a2. However, the concave shape is not limited to the above. For example, instead of the space defined by the bottom portion 17a2 and the side wall 17a1, a hemispherical depression such as the recess 40a of the stepped recess 40 may be used. In other words, a concave shape without a bottom portion may be used. This allows the shape of the protrusion 16b, which will be described later, to be simplified.

[0023] In this embodiment, the bottom 17a2 has a shape in which an arc, which is the cross-sectional shape of the second joint portion 17b, is cut from one side of a rectangle. A portion of the wall 17a1 erected on the arc-shaped portion of the bottom 17a2 is disposed to cover the side surface of the second joint portion 17b. The inner peripheral surface of the wall 17a1 is formed along a portion of the second joint portion 17b. This allows the side surface of the second joint portion 17b to be covered by a portion of the thin wall 17a1, effectively strengthening the bonding force between the first joint portion 17a1 and the second joint portion 17a2 with a small volume of resin (see FIG. 4B).

[0024] On the other hand, for example, if second joint part 17b is a prism with a rectangular cross section, wall part 17a1 of first joint part 17a may be a partially linear wall part 17a1 that contacts one side of the prism of second joint part 17b. In other words, wall part 17a1 is not limited to a curved shape, and may be linear.

[0025] The first joint portion 17a will be described in detail with reference to the cross-sectional view shown in Figure 5(B). If the diameter of the second runner portion B1 (the same applies to the first runner portion A1), which has a circular cross section, is R1, the thickness of the first joint portion 17a is t1. In this case, the thickness t1 is set to be smaller than the diameter R1. For example, if R1 is set to approximately 3.0 mm, the thickness t1 may be set to approximately 1.5 mm. In other words, the first joint portion 17a is formed thinner than the first runner portion A1 or the second runner portion B1.

[0026] Furthermore, at least a portion of inner peripheral surface 17a1a of wall portion 17a1 in the left-right direction in Figure 5(B) is an inclined surface that slopes outward from bottom 17a2 of the concave shape at an inclination angle Θ1 toward the top of wall portion 17a1. At least a portion of outer peripheral surface 17a1b of wall portion 17a1 is an inclined surface that slopes inward from the concave shape at an inclination angle Θ2 toward the top of wall portion 17a1. The inclination angles Θ1 and Θ2 can be, for example, approximately 5 degrees.

[0027] The wall portion 17a1 is configured so that its horizontal cross-sectional area gradually decreases from the bottom portion 17a2 toward the top of the wall portion 17a1. In other words, by making the inner and outer peripheral surfaces of the wall portion 17a1 inclined, the force acting on the first joint portion 17a when the runner R is removed from the mold can be reduced, and unnecessary force can be prevented from acting on the fastening portion between the first joint portion 17a and the second joint portion 17b. Therefore, the first joint portion 17a and the second joint portion 17b can be prevented from being released from the connection and separating when the runner R is removed from the mold. Furthermore, by preventing unnecessary force from acting on the fastening portion between the first joint portion 17a and the second joint portion 17b when the runner R is removed from the mold, it is possible to prevent the connection between the first joint portion 17a and the second joint portion 17b from already being weakened by the time molding is completed. Therefore, even when the resin molded product according to this embodiment is applied to plastic model parts and the runners that support them in a plastic model kit, it is possible to prevent the connection between first joint portion 17a and second joint portion 17b from being released due to vibration or impact while the plastic model kit is being transported in a product packaging box.

[0028] In this embodiment, the wall 17a1 and bottom 17a2 constituting the first joint portion 17a are each formed of a thin material, which further reduces the force acting on the first joint portion 17a when the runner R is removed from the mold and accelerates the hardening of the first joint portion 17a, which will be described later. For example, if the thickness t1 of the first joint portion 17a is approximately 1.5 mm, the thickness of the bottom 17a2 can be approximately 0.5 mm.

[0029] Furthermore, the first joint portion 17a is molded with a smaller volume than the volume of the first joint portion 17a of the adjacent first runner portion A1 at the same length. Specifically, with reference to FIG. 5(A), the axial length of the first joint portion 17a is defined as d1, and the axial length of the first runner portion A1 at the same length as the first joint portion 17a is defined as d2. d1 and d2 are the same length. In this case, the volume of the first joint portion 17a at the length d1 is set smaller than the volume of the first runner portion A1 at the length d2. Note that, in the past, the portion corresponding to the first joint portion was molded as a solid piece with a thickness of, for example, about 2.5 mm.

[0030] That is, as described above, the first joint portion 17a is set to be thinner than the first runner portion A1, and furthermore, has a concave shape composed of a thin wall portion 17a1 and a bottom portion 17a2, so that the volume is smaller than that of the first runner portion A1 of the same length. In this way, the volume is reduced and the contact area with the mold is increased compared to the first runner portion A1 adjacent to the first joint portion 17a, and therefore the first joint portion 17a can be hardened more quickly during molding, which will be described later.

[0031] <Forming process> The molding process of the runner R in the first embodiment will be described with reference to Figures 6(A) and 6(B). The cross-sectional views shown in Figures 6(A) and 6(B) are cross-sectional views of the mold taken along line VI-VI in Figure 3(A), for example. First, when the male mold 5 and the female mold 51 are closed as shown in Figure 1, an injection device (not shown) is connected to the mold and injects a first resin A, which flows from one side of the runner groove, into the molding space 18 and the runner groove 16 from, for example, the recess 11 connecting the injection nozzle (first injection process). Next, without waiting for the injection of the first resin A to be completed, the injection device injects a second resin B, which flows from the other side of the runner groove 16, into the mold from, for example, the recess 12 connecting the injection nozzle (second injection process).

[0032] In the first injection step, as shown in FIG. 6A, the first resin A flows from the left side to the right side of the figure, filling the space within the runner groove 16 on one surface (restriction surface) 36 side of the partition member 30a, where the protrusion 16b is arranged. At this time, the restriction surface side of the partition member 30a restricts the flow of the first resin A from one side (the left side in the figure) of the runner groove 16 (restriction step). In other words, one surface 36 of the partition member 30a is approximately perpendicular to the inflow direction of the molding resin material, and can block the flow of the molding resin material flowing toward this one surface 36 side. The first resin A is then blocked by one surface 36 of the partition member 30a, and its flow stops.

[0033] At this time, the first resin A forms a concave-shaped first joint portion (concave portion) 17a (first molding step) in the runner groove 16 on one surface (restriction surface) 36 side. The concave-shaped first joint portion 17a includes a wall portion 17a1 and a bottom portion 17a2 that surround a portion of the partition member 30a. Referring to FIGS. 3A and 3C, the protrusion 16b in the runner groove 16 includes a first side surface 16b1 facing the surface 16d of the runner groove 16 and a second side surface 16b2 that is spaced a predetermined distance from one surface of the partition member 30a and follows a portion of the partition member 30a. As shown in FIG. 3C, the second side surface 16b2 is spaced a predetermined distance d from one surface of the partition member 30a. As described above, the wall portion 17a1 of the first joint portion 17a includes an inclined surface, so that at least the first side surface 16b1 of the protrusion 16b and the surface 16d of the runner groove 16 are inclined.

[0034] As described above, the concave first joint portion 17a is formed by the thin wall portion 17a1 and bottom portion 17a2, and its volume is set small, so it hardens quickly. In other words, the first joint portion 17a has the thin bottom portion 17a2 and the thin wall portion 17a1 surrounding it due to the protrusion 16b of the runner groove 16, so the contact area with the mold is large and it hardens quickly.

[0035] For example, in a runner groove 16 without a protrusion 16b, a solid runner without a concave shape is formed in the location corresponding to the first joint portion. In this case, a certain amount of time is required for the inside of the solid runner to cool, which means that it takes a certain amount of time to harden compared to the concave-shaped first joint portion 17a of this embodiment. Therefore, the concave-shaped first joint portion 17a molded from the first resin A hardens more quickly (hardening process) than in the conventional method.

[0036] Next, as shown in FIG. 6B, a second resin B, for example, of a different color, is injected into the runner groove 16 by an injection nozzle connected to the connecting recess 55. When the second resin B flows from the other side of the runner groove 16 (from right to left in the figure), it is temporarily blocked by the other surface 37 of the small-diameter portion 35 of the partition member 30a, but then flows into the stepped recess 40. The flow pressure of this second resin B presses the hemispherical recess 41a of the stepped recess 40 in the direction of arrow A, and the partition member 30a is pressed down against the biasing force of the elastic member 31a. This state is shown in FIG. 3B. Therefore, the flow of the second resin B from the other side of the runner groove 16 causes the partition member 30a to retreat from the runner groove 16 (retraction process). In this way, the second resin B forms a joining portion that joins with the recessed portion formed in the first molding process (second forming process).

[0037] In other words, when the second resin B reaches the partition member 30a, the first joint portion 17a has already hardened, so after the first injecting unit injects the first resin A, the second injecting unit can inject the second resin B without waiting for the completion of injection of the first resin A. Therefore, it is possible to provide a resin molded product with a reduced molding time.

[0038] The timing at which second resin B reaches partition member 30a can be changed as needed depending on the position from the mold gate to partition member 30a and protrusion 16b of the present invention, but at least the area corresponding to first joint portion 17a hardens faster than before, thereby shortening the injection molding cycle and improving the degree of freedom in mold design. Comparing the molding cycle of the present invention with the conventional mold using the same mold design, the molding cycle can be shortened by, for example, 3 seconds.

[0039] In the runner R thus molded, as shown in Fig. 4, a cylindrical second joint portion 17b corresponding to the shape of the partition member 30a is fitted into the curved surface formed by part of the wall portion 17a1 of the first joint portion 17a. That is, the first joint portion 17a forms a molded recess that surrounds half of the small-diameter portion of the second joint portion 17b, and this molded recess embraces the second joint portion 17b, thereby strengthening the welding between the first joint portion 17a made of the first resin A and the second joint portion 17b made of the second resin B. Therefore, even when the resin molded product according to this embodiment is applied to plastic model parts in a plastic model kit and the runner that supports them, it is possible to prevent the welding between the first joint portion 17a and the second joint portion 17b from being released due to vibration or impact while the plastic model kit is being transported in a product packaging box.

[0040] 1 is then separated from the fixed mold body 3, and the pusher shaft 25 is pressed to move the pusher plate 20. The knockout pins 21 provided on the pusher plate 20 push out the multicolor runner R and the multicolor molded product adhering to the male mold 5 of the movable mold body 2, allowing them to be removed. In the above embodiment, the partition member 30 and the protrusion 16b are provided on the movable mold body 2 side, but they may also be provided on the fixed mold body 3 side. Also, although a coil spring 31 is used as the elastic member for biasing the partition member 30, other elastic parts such as rubber or a leaf spring may also be used.

[0041] Second Embodiment 7 and 8 show an example in which a pair of partition members 100 are arranged in the runner groove 85 so as to sandwich the protrusion 127, and the restriction surface 106 of each partition member 100 is arranged opposite the protrusion 127. The second embodiment differs from the first embodiment in that a pair of partition members 100 is provided, and the first and second embodiments are otherwise configured the same.

[0042] 2, the partition member 100 is formed in the shape of a round shaft, with a stepped recess 110 formed at its tip and a flange 102 at its bottom end. The rear of this partition member 100 is slidably mounted in a shaft hole 99 formed in the front push-out plate 90. The flange 102 of the partition member 100 is slidably mounted in the slide hole 96 of the front push-out plate 90, and is urged in the direction of the runner groove 85 by a spring 101 provided in a spring receiving hole 104 of the rear push-out plate 91, so as to engage with an upper wall 103 of the slide hole 96.

[0043] Furthermore, the flange 102 is pushed down against the elasticity of the spring 101 until it abuts against a step 117 formed at the top of the spring receiving hole 104. Furthermore, an engagement groove 116 is formed on one side of the sliding hole 96, and an engagement shaft 115 provided on the flange 102 is slidably engaged with this engagement groove 116. Therefore, the partition member 100 does not rotate.

[0044] The tip of the partition member 100 is biased by the elasticity of the coil spring 101, protruding into the runner groove 85 and pressing against the female die 122. One surface 106 of this partition member 100 is approximately perpendicular to the direction in which the molding resin material flows through the runner groove 85. The other surface 107 is formed with a stepped recess 110 that opens up to the upper end surface 109 of the partition member 100. A pair of these partition members 100 protrude into each runner groove 85. The two partition members 100, 100 are arranged so that one surface 106, 106 faces each other.

[0045] As shown in FIG. 8(A), the injection device causes a first resin A to flow from one side (the left side in the figure) of the runner groove 85. This first resin A flows into a stepped recess 110 formed on the other surface 107 of the partition member 100 on the left side in the figure. The flow pressure of this first resin A presses the bottom surface 111 of the stepped recess 110, and the partition member 100 on the left side in the figure is pressed down against the biasing force of the elastic member 101. The first resin A continues to flow within the runner groove 85 and is blocked by one surface 106 of the next partition member 100, stopping its flow. At this time, a concave first joint portion 217a is formed.

[0046] As shown in FIG. 8(B), when a second resin B of a different color is injected from the other side of the runner groove 85 (the right side in the figure) by the injection device, this second resin B flows into a stepped recess 110 formed on the other surface 107 of the partition member 100 on the right side in the figure. The flow pressure of this second resin B presses against the bottom surface 111 of the stepped recess 110, and the partition member 100 on the right side in the figure is pressed down against the biasing force of the elastic member 101. The second resin B of a different color flows into the position where the partition member 100 on the right side in the figure was located, and is welded to the initial first resin A. In this way, a multi-colored runner 84 is formed within the runner groove 85.

[0047] Runner 84 formed as described above is shown in Figures 10 and 11. Runner 84 shown in Figures 10 and 11 has the same component as runner R shown in Figures 5 and 6, with the addition of a 2 to the beginning of its reference number. Runner 84 has the same shape as runner R, except that first joint portion 217a of runner 84 has a portion 200 formed in a shape corresponding to partition member 100.

[0048] In the second embodiment described above, for example, because partition members 100 are disposed on both sides of protrusion 127 of runner groove 85, it is possible to, for example, perform simultaneous injection without adjusting the injection time of each injection nozzle. In this way, by providing a pair of opposing partition members 30 in one runner groove, if either first resin A or second resin B reaches protrusion 127 first, the curing of that resin will be accelerated, and therefore the resins can be injected simultaneously without adjusting the injection time of each injection nozzle, further improving molding efficiency.

[0049] As explained above, in this embodiment, unlike conventional molding devices, there is no need to wait for the joint portions to harden, and an extremely simple mechanism that simply provides a protrusion with one mold can shorten the injection time when molding a multi-color runner or a multi-color molded product. Furthermore, because the mechanism is simple and can be made small and lightweight, it can be manufactured inexpensively and places little strain on the injection device when attached to it. Furthermore, because it is not necessary to inject molding resin materials of each color sequentially, and they can be injection molded simultaneously, the molding cycle for the molded product is extremely short, improving production efficiency and reducing production costs.

[0050] Furthermore, because the amount of first resin A in the joint portion near one surface of the partition member is reduced, the first resin A near one surface of the partition member hardens faster than with conventional molding devices. This allows the second resin B to be injected more quickly than with conventional molding devices, improving molding efficiency and increasing the degree of freedom in mold design. The present invention is applicable to resin molded products that are distributed without separating the molded product from the runner, such as plastic model kits. [Explanation of symbols]

[0051] 17a: first joint portion, 17a1: wall portion, 17b: second joint portion, A: first resin, B: second resin, 84: runner, R: runner

Claims

1. A resin molded product is molded from a plurality of resins and has a joint portion at which a first resin and a second resin join in a runner, the joint portion includes a first joint portion molded from the first resin and a second joint portion molded from the second resin, the first joint portion is formed to have a wall portion that contacts a part of the second joint portion; the wall portion is thinner than the runner, and the first joint portion is thinner than the runner; A resin molded product, characterized in that at least a portion of an inner peripheral surface of the wall portion is an inclined surface that slopes outwardly toward the end of the wall portion.

2. A resin molded product molded from multiple resins and having a joint portion where a first resin and a second resin join on a runner, the joint portion includes a first joint portion molded from the first resin and a second joint portion molded from the second resin, the first joint portion is formed to have a wall portion that contacts a part of the second joint portion; the wall portion is thinner than the runner, and the first joint portion is thinner than the runner, A resin molded product, wherein at least a portion of the outer peripheral surface of the wall portion is an inclined surface that slopes inward toward the end of the wall portion.

3. A resin molded product molded from multiple resins and having a joint portion where a first resin and a second resin join on a runner, the joint portion includes a first joint portion molded from the first resin and a second joint portion molded from the second resin, the first joint portion is formed to have a wall portion that contacts a part of the second joint portion; the wall portion is thinner than the runner, and the first joint portion is thinner than the runner, A resin molded product, characterized in that the first joint portion is molded to have a smaller volume than the volume of the first joint portion of an adjacent runner over the same length.

4. The resin molded product according to claim 1 , wherein the wall portion covers the part of the second joint portion.

5. 5. The resin molded product according to claim 1, wherein an inner circumferential surface of the wall portion is formed along a part of the second joint portion.

6. an injection device that injects a molding material; a plurality of molds that, when fitted together, form a molding space for molding a molded product and a runner groove connected to the molding space; a partition member provided in at least one of the molds, capable of entering and leaving the runner groove, and partitioning the inside of the runner groove; A molding apparatus comprising: the injection device is connected to the mold and injects the molding material into the molding space and the runner groove; the partition member includes a regulating surface that regulates the flow of the molding material flowing from one side of the runner groove, and a stepped recess that allows the partition member to retract from the runner groove by the flow of the molding material flowing from the other side of the runner groove, the mold includes a protrusion that protrudes into the runner groove on the regulating surface side and forms a wall portion on the runner that comes into contact with a part of the partition member, the protrusion has a side surface, and the wall is formed by the side surface; The width and thickness of the wall portion are formed thinner than those of the runner, A molding device characterized in that the protrusion portion has an inclined surface for molding at least a portion of the inner surface of the wall portion of the runner so that it slopes outward from the wall portion as it approaches the end of the wall portion.

7. An injection device that injects a molding material; a plurality of molds that, when fitted together, form a molding space for molding a molded product and a runner groove connected to the molding space; a partition member provided in at least one of the molds, capable of entering and leaving the runner groove, and partitioning the inside of the runner groove; A molding apparatus comprising: the injection device is connected to the mold and injects the molding material into the molding space and the runner groove; the partition member includes a regulating surface that regulates the flow of the molding material flowing from one side of the runner groove, and a stepped recess that allows the partition member to retract from the runner groove by the flow of the molding material flowing from the other side of the runner groove, the mold includes a protrusion that protrudes into the runner groove on the regulating surface side and forms a wall portion on the runner that comes into contact with a part of the partition member, the protrusion has a side surface, and the wall is formed by the side surface; The width and thickness of the wall portion are formed thinner than those of the runner, A molding apparatus characterized in that the runner groove has an inclined surface for forming at least a portion of the outer peripheral surface of the wall portion of the runner so that it slopes inward toward the end of the wall portion.

8. 8. The molding apparatus according to claim 6, wherein the protrusion has a side surface that is spaced a predetermined distance from the partition member and that extends along a portion of the partition member.

9. The injection device comprises at least a first injection unit that injects a first resin that flows from the one of the runner grooves; a second injection section that injects a second resin that flows from the other of the runner grooves; Equipped with 9. The molding device according to claim 6, wherein after the first injection section has injected the first resin, the second injection section injects the second resin without waiting for completion of injection of the first resin.

10. The mold is a movable mold attached to the movable side of the molding device; a fixed-side mold attached to a fixed side of the molding device; Equipped with The molding apparatus according to any one of claims 6 to 9, wherein the partition member and the protrusion are disposed on the movable mold.

11. A molding device described in any one of claims 6 to 10, characterized in that the partition member is positioned while being biased in a direction protruding into the runner groove by an elastic member, and is retracted from the runner groove against the biasing force of the elastic member by the molding material flowing into the step recess.

12. a pair of the partition members are arranged in the runner groove so as to sandwich the protrusion, The molding apparatus according to claim 6 , wherein the restricting surface of each partition member is disposed opposite the protrusion.

13. an injection device that injects molding resin; a plurality of molds that, when fitted together, form a molding space for molding a molded product and a runner groove connected to the molding space; a partition member provided in at least one of the molds, capable of entering and leaving the runner groove, and partitioning the inside of the runner groove; A molding method for a molding device comprising: a first injection step in which the injection device is connected to the mold and injects a first resin flowing from one of the runner grooves into the molding space and the runner groove; a second injection step in which the injection device injects a second resin flowing from the other of the runner grooves into the mold without waiting for the completion of injection of the first resin; a restricting step in which the partition member restricts the flow of the first resin flowing from the one side of the runner groove; a first molding step in which the first resin is molded into the runner groove on the regulating surface side to form a wall portion surrounding a part of the partition member; a curing step of curing the wall portion molded from the first resin; a retraction step in which the partition member is retracted from the runner groove by the flow of the second resin flowing from the other of the runner grooves; a second molding step in which the second resin is used to form a joint portion that joins with the wall portion molded in the first molding step; Equipped with The width and thickness of the wall portion are formed thinner than the runner formed by the runner groove, A molding method for a molding device, characterized in that in the first molding process, the wall portion is molded so that at least a portion of the inner surface of the wall portion has an inclined surface that slopes outwardly toward the end of the wall portion.

14. An injection device that injects molding resin; a plurality of molds that, when fitted together, form a molding space for molding a molded product and a runner groove connected to the molding space; a partition member provided in at least one of the molds, capable of entering and leaving the runner groove, and partitioning the inside of the runner groove; A molding method for a molding device comprising: a first injection step in which the injection device is connected to the mold and injects a first resin flowing from one of the runner grooves into the molding space and the runner groove; a second injection step in which the injection device injects a second resin flowing from the other of the runner grooves into the mold without waiting for the completion of injection of the first resin; a restricting step in which the partition member restricts the flow of the first resin flowing from the one side of the runner groove; a first molding step in which the first resin is molded into the runner groove on the regulating surface side to form a wall portion surrounding a part of the partition member; a curing step of curing the wall portion molded from the first resin; a retraction step in which the partition member is retracted from the runner groove by the flow of the second resin flowing from the other of the runner grooves; a second molding step in which the second resin is used to form a joint portion that joins with the wall portion molded in the first molding step; Equipped with The width and thickness of the wall portion are formed thinner than the runner formed by the runner groove, A molding method for a molding device, characterized in that in the first molding process, the wall portion is molded so that at least a portion of the outer surface of the wall portion has an inclined surface that slopes inward toward the end of the wall portion.

15. A mold forming a molding space for molding a molded product and a runner groove connected to the molding space, a partition member that divides the runner groove and is capable of entering and exiting the runner groove and that includes a regulating surface that regulates the flow of molding material flowing from one side of the runner groove and a stepped recess that allows the partition member to retract from the runner groove due to the flow of molding material flowing from the other side of the runner groove; a protrusion that protrudes into the runner groove on the restricting surface side and forms a wall portion on the runner that covers a part of the partition member; Equipped with The width and thickness of the wall portion are formed thinner than those of the runner, A mold characterized in that the protrusion portion has an inclined surface for molding at least a portion of the inner surface of the wall portion of the runner so that it slopes outward from the wall portion as it approaches the end of the wall portion.

16. A mold forming a molding space for molding a molded product and a runner groove connected to the molding space, a partition member that divides the runner groove and is capable of entering and exiting the runner groove and that includes a regulating surface that regulates the flow of molding material flowing from one side of the runner groove and a stepped recess that allows the partition member to retract from the runner groove due to the flow of molding material flowing from the other side of the runner groove; a protrusion that protrudes into the runner groove on the restricting surface side and forms a wall portion on the runner that covers a part of the partition member; Equipped with The width and thickness of the wall portion are formed thinner than those of the runner, A mold characterized in that the runner groove has an inclined surface for forming at least a portion of the outer peripheral surface of the wall portion of the runner so that it slopes inward toward the end of the wall portion.

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