JP7601120B2 - Composite molding - Google Patents

Description

The present disclosure relates to a composite molding.

Die slide injection molding (DSI molding) is a technique for forming structures with internal spaces through injection molding, and is used to manufacture a variety of products.

One known technique using die slide injection molding is to butt two divided primary molded products together to form a butt surface and a joining groove, and then fill the joining groove with resin to obtain an integrated molded product (see, for example, Patent Document 1).

JP 2002-361681 A

In the method of forming a joining groove and filling the joining groove with resin to obtain an integrated molded product as described in Patent Document 1, it is possible to butt two divided primary molded products together to form a configuration having an uneven portion fitted in a position adjacent to the joining groove. For example, a primary molded product having a recess and a primary molded product having a protrusion that fits into the recess are butted together to form an uneven portion fitted in a position adjacent to the joining groove. By providing such fitted uneven portions, it is possible to prevent secondary resin from leaking from the gap between the butted surfaces when filling the joining groove with resin.

However, when the mating uneven parts are subjected to pressure when filling the joining groove with molding material such as resin, there is a risk that part of the uneven parts may deform or break.

This disclosure has been made in consideration of the above-mentioned conventional circumstances, and aims to provide a composite molding in which deformation and destruction of the interlocking uneven portions is suppressed.

Specific means for achieving the above object are as follows.
<1> A first primary molding member having a convex portion located along a longitudinal direction and a concave portion adjacent to the convex portion and located along the longitudinal direction;
a second primary molding member having a first recess located along a longitudinal direction and into which the protrusion is fitted, and a second recess located adjacent to the first recess and along a longitudinal direction and facing the recess of the first primary molding member;
a secondary molding member filling a first space formed by the recess of the first primary molding member facing the second recess when the protrusion of the first primary molding member is fitted into the first recess of the second primary molding member,
A composite molding in which at least a portion of the region on the secondary molding member side in a cross section of the protrusion and a cross section of the first recess perpendicular to the longitudinal direction is arc-shaped.
<2> The composite molded body described in <1>, wherein a second space between the convex portion and the first recess formed on the secondary molding member when the convex portion of the first primary molding member is fitted into the first recess of the second primary molding member is filled with molding material contained in the secondary molding member.
<3> The composite molding according to <2>, wherein the second space is gradually narrowed between the surface of the protrusion and the surface of the first recess from the secondary molding member side toward the opposite side.
<4> The composite molding according to any one of <1> to <3>, wherein the entire surface of the secondary molding member on each of the surfaces of the protruding portion and the first recessed portion is arc-shaped.
<5> The composite molding according to any one of <1> to <4>, wherein a cross section of the first space perpendicular to the longitudinal direction is circular.
<6> The composite molding according to any one of <1> to <5>, wherein the ratio of the maximum width of the first recess to the maximum width of the first space, i.e., maximum width of first recess/maximum width of first space, is 0.2 to 1.5.
<7> The composite molding according to any one of <1> to <6>, wherein a ratio of a maximum depth of the first recess to a maximum height of the first space (maximum depth of the first recess/maximum height of the first space) is 0.1 to 1.

According to the present disclosure, it is possible to provide a composite molding in which deformation and destruction of the mated uneven portions is suppressed.

FIG. 1 is a schematic cross-sectional view of a main part of a composite molded body according to a first embodiment. FIG. 2A is a schematic cross-sectional view of the first embodiment when a first space and a fitted concave-convex portion are formed. FIG. FIG. 2B is a schematic cross-sectional view showing a process for producing the composite molded body of the first embodiment by filling the first space in FIG. 2A with resin. FIG. 3 is a schematic cross-sectional view of a main part of a composite molded body according to the second embodiment. FIG. 4 is a schematic cross-sectional view of a main part of a composite molded body according to the third embodiment. FIG. 5 is an end view showing a state in which the mold for forming the composite compact is opened. FIG. 6A is an enlarged view of region α in FIG. FIG. 6B is an enlarged view of region β in FIG. FIG. 7 is an end view showing a state in which a mold for forming a composite molded body is closed during primary injection. FIG. 8 is an end view showing a state after the second mold has been slid in the direction of arrow A. FIG. FIG. 9 is a diagram showing a state in which the first and second molds are closed after the second mold has been slid and moved, and the second resin material has been secondarily injected. FIG. 10 is an enlarged view of region γ in FIG. FIG. 11A is a schematic cross-sectional view of the main part when the first space and the fitted concave-convex portion are formed. FIG. 11B is a schematic cross-sectional view of a main part when the first space in FIG. 11A is filled with resin to produce a composite molded body to be compared.

The composite molded body of the present disclosure will be described below with reference to the drawings. Note that the size of the members in each drawing is conceptual, and the relative relationship between the sizes of the members is not limited thereto. In addition, members having substantially the same function are given the same reference numerals throughout the drawings, and duplicated descriptions may be omitted.
The present disclosure is not limited to the following embodiments. In the following embodiments, the components (including element steps, etc.) are not essential unless otherwise specified. The same applies to numerical values and their ranges, and do not limit the present disclosure.

In the present disclosure, the term "step" includes not only a step that is independent of other steps, but also a step that cannot be clearly distinguished from other steps as long as the purpose of the step is achieved.
In the present disclosure, the numerical ranges indicated using "to" include the numerical values before and after "to" as the minimum and maximum values, respectively.
In the present disclosure, in which numerical ranges are described in stages, the upper or lower limit value described in one numerical range may be replaced with the upper or lower limit value of another numerical range described in stages.
In the present disclosure, "(meth)acrylic" means at least one of acrylic and methacrylic.

[Composite Molded Body]
The composite molded body of the present disclosure comprises a first primary molding member having a convex portion located along the longitudinal direction and a concave portion adjacent to the convex portion and located along the longitudinal direction; a second primary molding member having a first concave portion located along the longitudinal direction and into which the convex portion is fitted, and a second concave portion adjacent to the first concave portion and located along the longitudinal direction and facing the concave portion of the first primary molding member; and a secondary molding member filling a first space formed when the concave portion of the first primary molding member and the second concave portion face each other when the convex portion of the first primary molding member is fitted into the first concave portion of the second primary molding member, and at least a portion of the region on the secondary molding member side is arc-shaped in each of a cross section of the convex portion and a cross section of the first concave portion perpendicular to the longitudinal direction.

In the composite molding of the present disclosure, deformation and destruction of the mated concave-convex portions are suppressed. The reason for this is presumed to be as follows.

First, the composite molded body to be compared will be described with reference to Figure 11. Figure 11A is a schematic cross-sectional view of the main part when the convex part of the first primary molding member and the concave part of the second primary molding member are fitted together to form a first space and a fitted concave-convex part, and Figure 11B is a schematic cross-sectional view of the main part when the first space is filled with resin. Figure 11 illustrates the shape of the cross section perpendicular to the longitudinal direction.

11A, a first primary molding member 101 having a convex portion 103 and a second primary molding member 102 having a concave portion 104 form a circular first space 105 by fitting the trapezoidal convex portion 103 and concave portion 104, respectively. Furthermore, on the first space 105 side, a second space 106 is formed between the fitted convex portion 103 and concave portion 104, and on the opposite side to the first space 105 side, the slope constituting the convex portion 103 and the slope constituting the concave portion 104 are in contact. The first space 105 and the second space 106 are connected via a flow path 108 through which the resin flows.

As shown in Figure 11B, resin is filled into the first space 105 to form a secondary molded member 107 that joins the first primary molded member 101 and the second primary molded member 102. The resin supplied to the first space 105 is also supplied to the second space 106 via the resin. In this manner, the composite molded body 100 is manufactured.

When the resin supplied to the first space 105 is also supplied to the second space 106, as shown by arrow A in Fig. 11B, the uneven portion receives the pressure applied when filling the first space 105 with the resin, and stress tends to concentrate on the uneven portion. As a result, deformation and destruction tend to occur starting from the edges of the uneven portion, such as dotted line portion X and dotted line portion Y.

On the other hand, in the composite molded body of the present disclosure, at least a portion of the area on the secondary molding member side is arc-shaped in the cross section of each of the convex and concave portions that make up the uneven portion. This allows at least a portion of the pressure applied when filling the first space with a molding material such as resin to be dispersed in the direction of the first primary molding member side, reducing the concentration of stress on the uneven portion. As a result, deformation and destruction of the uneven portion are less likely to occur.

First Embodiment
A composite molded body of a first embodiment, which is an example of the composite molded body of the present disclosure, will be described with reference to Figures 1 and 2. Figure 1 is a schematic cross-sectional view of a main part of the composite molded body of the first embodiment. Figure 2A is a schematic cross-sectional view of the main part when a first space and a fitted uneven portion are formed in the first embodiment, and Figure 2B is a schematic cross-sectional view of the main part when the first space in Figure 2A is filled with resin to manufacture the composite molded body of the first embodiment. Figure 1 illustrates the shape of a cross section perpendicular to the longitudinal direction of the composite molded body.

1, the composite molding 10 comprises a first primary molding member 1 having a convex portion 3, a second primary molding member 2 having a concave portion 4 (first concave portion), and a secondary molding member 7 filling a first space formed by the concave portion of the first primary molding member 1 facing the concave portion (second concave portion) of the second primary molding member 2. Furthermore, in the composite molding 10, the cross section of the convex portion 3 and the cross section of the concave portion 4 are each arc-shaped. Point O represents the center of the arc-shaped convex portion.

The recess of the first primary molding member 1 and the recess (second recess) of the second primary molding member 2 that form the first space are positioned along the longitudinal direction. Therefore, the secondary molding member 7 that fills the first space is also positioned along the longitudinal direction.

The first primary molded member 1 has a rod-shaped convex portion 3 positioned along the longitudinal direction, and the second primary molded member 2 has a groove-shaped concave portion 4 positioned along the longitudinal direction. This allows the fitted concave-convex portions to exist along the longitudinal direction. It is preferable that the fitted concave-convex portions exist along the secondary molded member 7 filling the first space.
The longitudinal direction means a direction perpendicular to the width direction (left-right direction in FIG. 1) and the height direction (up-down direction in FIG. 1).

In the composite molding 10, the second space formed between the convex portion 3 and the concave portion 4 on the secondary molding member 7 side is filled with a resin constituting the secondary molding member 7. The secondary molding member 7 may be formed by filling the second space with a molding material other than resin, for example, a material containing metal and other components, or a material containing resin, metal, and other components. Examples of metals include iron, stainless steel, aluminum, copper, alloys, etc. Examples of other components include particulate fillers, fibrous fillers, release agents, etc.
The contents of other components contained in these members may be appropriately set depending on the application of the composite molded article.
The other components may be a surface treatment agent for modifying the surface of the inorganic material.

A part of the manufacturing process of the composite molding 10 will be described with reference to Fig. 2. As shown in Fig. 2A, the circular convex portion 3 and the concave portion 4 are fitted together, and the concave portion of the first primary molding member 1 and the concave portion (second concave portion) of the second primary molding member 2 are faced to each other to form a circular first space 5. Furthermore, the concave portion 4 and the convex portion 3 are in contact with each other at the bottom of the concave portion 4, so that a second space 6 is formed between the fitted convex portion 3 and the concave portion 4 on the first space 5 side, and a space is also formed between the fitted convex portion 3 and the concave portion 4 on the opposite side to the first space 5 side. In Fig. 2A, the space and the second space 6 are symmetrical with respect to a line segment passing through point O, but the present invention is not limited to this configuration.
On the side opposite to the first space 5, a space may or may not exist between the engaged convex portion 3 and concave portion 4.

In Fig. 2A, the first space 5 and the second space 6 are connected via a flow path 8 through which the resin flows. In Fig. 2A, an uneven portion in which the arc-shaped convex portion 3 and the concave portion 4 are fitted is formed on the left side of the first space 5 when viewed from the front, but it is preferable that an uneven portion in which the arc-shaped convex portion and the concave portion are fitted is also formed on the right side of the first space 5 when viewed from the front. It is more preferable that the uneven portions in which the arc-shaped convex portion and the concave portion are fitted are formed symmetrically on the left and right sides of the first space 5.

As shown in FIG. 2B, resin is filled into the first space 5 to form a secondary molded member 7 that joins the first primary molded member 1 and the second primary molded member 2. The resin supplied to the first space 5 is also supplied to the second space 6 via a flow path 8. In this manner, a composite molded body 10 is produced.

In the first embodiment, the cross section of the convex portion 3 and the cross section of the concave portion 4 that constitute the uneven portion have an arc-shaped region on the secondary molding member 7 side. As a result, when the resin supplied to the first space 5 is also supplied to the second space 6, as shown by arrow B in Figure 2B, the pressure when filling the first space 5 with resin is applied in the direction of point O, which is the direction toward the first primary molding member 1 side. Therefore, the concentration of stress on the uneven portion is mitigated, and as a result, the uneven portion is less likely to deform or break.

2B, the second space 5 may have a space between the convex portion 3 and the concave portion 4 that gradually narrows from the secondary molding member 7 side toward the opposite side (i.e., from the right side toward the left side when viewed from the front). This makes it easier for the pressure applied when filling the first space 5 with resin to be applied in the direction of point O toward the first primary molding member 1 side when resin is supplied to the second space 6 through the first space 5, and tends to favorably suppress deformation and destruction of the uneven portion.

2A, the cross section of the first space 5 perpendicular to the longitudinal direction is preferably circular, so that the pressure applied to the first space 5 when filling the first space 5 with resin is easily distributed uniformly in all directions.
The cross section of the first space is not limited to a circular shape, but may be a rectangular shape, an elliptical shape, or the like.

As in the first embodiment, in each of the cross sections of the convex portion and the cross section of the concave portion, the entire region on the secondary molding member side may be arc-shaped, or only a portion of the region on the secondary molding member side may be arc-shaped. Also, in the present disclosure, along the longitudinal direction, the entire region on the secondary molding member side may be arc-shaped, or only a portion of the region on the secondary molding member side may be arc-shaped.

In the present disclosure, the arc shape is not particularly limited as long as it is a curved shape, and may be a circular arc shape, an ellipse shape, an arch shape, etc.

The molding material constituting the first primary molded member and the second primary molded member is not particularly limited, and examples thereof include resins, the above-mentioned metals, and other components.
Resins that can be used to form the first and second primary molded members and the secondary molded member can be appropriately selected from conventionally known resins depending on the application of the composite molded body.
Resins that can form these members include, independently of one another, thermoplastic resins, elastomers, and the like.

Specific examples of thermoplastic resins include polyimide resin, polyamideimide resin, polyamide resin, polyetherimide resin, polybenzoxazole resin, polybenzimidazole resin, polystyrene resin, acrylonitrile-butadiene-styrene copolymer resin, acrylonitrile-styrene copolymer resin, polyethylene resin, polypropylene resin, polyvinyl chloride resin, polyvinylidene chloride resin, polycarbonate resin, (meth)acrylic resin, polyester resin, polyacetal resin, polyphenylene sulfide resin (PPS), etc.

Specific examples of elastomers include silicone rubber, styrene butadiene rubber (SBR), nitrile rubber (NBR), urethane rubber, etc.

The molding materials constituting the first primary molding member and the second primary molding member may be the same or different. Also, the molding material constituting the first primary molding member or the second primary molding member and the molding material constituting the secondary molding member may be the same or different.

From the viewpoint of moldability, a thermoplastic resin is preferred as the molding material constituting the first primary molding member, the second primary molding member, and the secondary molding member. When these members contain a thermoplastic resin, it is preferred that the melting point or glass transition temperature of the thermoplastic resin constituting the first primary molding member and the second primary molding member is lower than the melting point or glass transition temperature of the thermoplastic resin constituting the secondary molding member in order to increase the bonding strength by making it easier to melt or soften the thermoplastic resin constituting the first primary molding member and the second primary molding member when filling the first space with the thermoplastic resin constituting the secondary molding member.

The ratio of the maximum width of the recess 4 (first recess) to the maximum width of the first space 5 in which the secondary molded member is formed, i.e., maximum width of recess/maximum width of first space, may be 0.2 to 1.5.

The ratio of the maximum depth of the recess 4 to the maximum height of the first space 5, i.e., maximum depth of the recess/maximum height of the first space, may be between 0.1 and 1.

The maximum width of the protrusion 3 relative to the maximum width of the recess 4 may be such that the maximum width of the recess 4 is equal to or greater than the maximum width of the protrusion 3, and the maximum width of the recess 4 may be greater than the maximum width of the protrusion 3.

The maximum depth of the recess 4 relative to the maximum height of the protrusion 3 may be such that the maximum height of the protrusion is equal to or greater than the maximum depth of the recess, and the maximum height of the protrusion may be greater than the maximum depth of the recess.

The maximum distance from point O to the surface of convex portion 3 (if the cross section of convex portion 3 is arc-shaped, the radius of a circle centered at point O and with the surface of convex portion 3 as its circumference) is less than the maximum distance from point O to the surface of concave portion 4.

Second Embodiment
A composite molded body of a second embodiment, which is another example of the composite molded body of the present disclosure, will be described with reference to Fig. 3. Fig. 3 is a schematic cross-sectional view of a main part of the composite molded body of the second embodiment. Fig. 3 shows a composite molded body 20 having a structure in which a convex portion 13 of a first primary molding member 11 is fitted into a concave portion 14 of a second primary molding member 12. The second embodiment is similar to the first embodiment, except that instead of the convex portion 3, a circular arc-shaped convex portion 13 that exists only on the secondary molding member 7 side is used, and the convex portion 13 is fitted into the concave portion 14.

In the second embodiment, when the molding material such as resin supplied to the first space is also supplied to the second space, the pressure applied when filling the first space with the molding material such as resin is applied in the direction of point O, which is the direction toward the first primary molding member 11. Therefore, the concentration of stress on the unevenly shaped portion is alleviated, and as a result, deformation and destruction of the unevenly shaped portion are less likely to occur.

Third Embodiment
A composite molded body of a third embodiment, which is another example of the composite molded body of the present disclosure, will be described with reference to FIG. 4. FIG. 4 is a schematic cross-sectional view of a main part of the composite molded body of the third embodiment. FIG. 4 shows a composite molded body 30 having a structure in which the convex portion 23 of the first primary molding member 21 is fitted into the concave portion 24 of the second primary molding member 22. In the composite molded body 10 of the first embodiment shown in FIG. 1, the maximum distance from point O, which is the center of the arc-shaped convex portion 3, to the surface of the convex portion 3 and the maximum height of the convex portion 3 are approximately equal, but the present invention is not limited to such a configuration. For example, as in the composite molded body 30 of the third embodiment, the maximum distance from point O', which is the center of the arc-shaped convex portion 23, to the surface of the convex portion 23 may be greater than the maximum height of the convex portion 23. As a result, in the composite molded body 30 shown in FIG. 4, the shape of the convex portion is gentler than that of the composite molded bodies 10 and 20 shown in FIG. 1 and FIG. 3.

In the third embodiment, when the molding material such as resin supplied to the first space is also supplied to the second space, the pressure applied when filling the first space with the molding material such as resin is applied in the direction of point O', which is the direction toward the first primary molding member 21. Therefore, the concentration of stress on the uneven portion is alleviated, and as a result, deformation and destruction of the uneven portion are less likely to occur.

The composite molding of the present invention is not limited to the first to third embodiments described above, and includes various modified examples within the technical concept of the present invention.

The composite molded body of the present disclosure may be manufactured by any method, for example, by a die slide injection (DSI) molding method as described below. Hereinafter, a method for manufacturing a composite molded body of one embodiment by a DSI molding method using a resin material will be described with reference to Figures 5 to 10.

First, the mold used in the DSI molding method will be described.
Fig. 5 is an end view showing a state in which a mold for forming a composite molded body is opened, and Fig. 7 is an end view showing a state in which a mold for forming a composite molded body is closed during primary injection.

5 and 7, the mold 48 is provided in a molding machine (not shown) that performs die slide injection (DSI) molding. The mold 48 includes a first mold 50 and a second mold 52. The first mold 50 and the second mold 52 are formed from a metal material such as stainless steel.

The first mold 50 is provided with a cavity portion 54 for forming the first primary molded member 1. The cavity portion 54 has a recess corresponding to the external shape of the first primary molded member 1 formed therein.
The second mold 52 is provided with a core portion 55 for forming the first primary molded member 1 together with the cavity portion 54. The core portion 55 is formed with a convex portion corresponding to the internal shape of the first primary molded member 1. As shown in Fig. 6A, the area α at both ends of the core portion 55 is provided with a concave portion 44 for forming the convex portion 3 of the first primary molded member 1, and a convex portion 46 for forming a concave portion for forming a first space by combining with the second primary molded member 2. The second mold 52 may also be formed with an uneven shape that allows other internal shapes of the first primary molded member 1 to be formed.

The second mold 52 is provided with a cavity portion 56 for forming the second primary molded member 2. The cavity portion 56 has a recessed portion formed therein that corresponds to the external shape of the second primary molded member 2.
The first mold 50 is provided with a core portion 53 for forming the second primary molded member 2 together with a cavity portion 56. The core portion 53 is formed with a convex portion corresponding to the internal shape of the second primary molded member 2. As shown in FIG. 6B, in the region β at both ends of the core portion 53, a convex portion 40 for forming the concave portion 4 of the second primary molded member 2 and a convex portion 42 for forming a concave portion for forming a first space by combining with the first primary molded member 1 are provided. In addition, the first mold 50 may be formed with an uneven shape that allows other internal shapes of the second primary molded member 2 to be formed.

The first mold 50 is formed with a gate 62 for injecting the first resin material for primary injection into the cavity portion 54 and the cavity portion 56. The position of the injection opening of the gate 62 is not particularly limited.

Furthermore, a gate for injecting the second resin material for secondary injection is formed in the first mold 50. In this embodiment, the gate 62 for injecting the first resin material for primary injection also serves as a gate for injecting the second resin material for secondary injection, but the gate for injecting the second resin material for secondary injection may be provided independently of the gate 62 for injecting the first resin material for primary injection.
Components that can be contained in the first resin material include the resins that can form the first primary molded member and the second primary molded member, the above-mentioned metals, other components, and the like.
Examples of components that can be contained in the second resin material include the resin that can constitute the secondary molded member, the above-mentioned metals, and other components.

In addition to the mold 48, the molding machine includes an injector 64 that injects a first resin material for primary injection and a second resin material for secondary injection from a gate 62, a first driving means for switching between closing and opening of the first mold 50 and the second mold 52, and a second driving means for sliding the second mold 52 relative to the first mold 50 when the first mold 50 and the second mold 52 are in the open state.
Furthermore, the molding machine includes a control unit for controlling the operations of various devices such as the injection machine 64, the first driving means, the second driving means, etc. The control unit is composed of a non-volatile memory in which a program is stored, a volatile memory which is a temporary storage area for executing the program, an input/output port, a processor which executes the program, etc.

Next, the operation of a molding machine used to carry out the method for producing a composite molded article according to one embodiment will be described.
In one embodiment, a control unit of the molding machine executes a program to control the operations of the first driving means, the second driving means, the injector 64, etc., thereby implementing the method for manufacturing a composite molded body.

Before the first primary molded member 1 and the second primary molded member 2 are formed by the molding machine, the first mold 50 and the second mold 52 are in an open state, as shown in Figure 5.

Next, the first mold 50 and the second mold 52 are closed as shown in Figure 7 to start molding the first primary molded member 1 and the second primary molded member 2.

After the mold is closed, the first resin material is primarily injected from the injector 64 into the cavity portion 54 and the cavity portion 56 through the gate 62. This forms the first primary molded member 1 and the second primary molded member 2, respectively. In this embodiment, the method of simultaneously forming the first primary molded member 1 and the second primary molded member 2 in parallel has been described, but this configuration is not limited to this. For example, the first primary molded member 1 and the second primary molded member 2 may be formed sequentially, or the second primary molded member 2 molded separately may be placed in the cavity portion 56 in advance, and only the first primary molded member 1 may be molded by the injector 64.

Next, as shown in Fig. 8, the second mold 52 is slid in the direction of arrow A to bring the first primary molded member 1 and the second primary molded member 2 face each other. Then, as shown in Fig. 9, the first mold 50 and the second mold 52 are closed.

When the first mold 50 and the second mold 52 shown in Figure 9 are closed, the convex portion 3 of the first primary molded member 1 and the concave portion 4 of the second primary molded member 2 are engaged with each other, and a first space is further formed.

Next, as shown in Figure 9, the second resin material is secondarily injected from the injector 64 into the first space through the gate 62. By filling the first space with the secondarily injected second resin material, a hollow composite molded body 10A is obtained in which the first primary molded member 1 and the second primary molded member 2 are joined by the secondary molded member 7, as shown in Figures 9 and 10. At this time, the second resin material supplied to the first space 5 is also supplied to the second space.

In addition, in this embodiment, when the second resin material is supplied to the second space through the first space, the pressure applied when filling the first space with resin is more likely to be applied in the direction toward the first primary molding member 1, which tends to effectively suppress deformation and destruction of the uneven shaped portion.

Below, the stress generation during the manufacturing of composite moldings was analyzed using computer simulation.

(Analysis model 1)
As the analysis model 1, a first primary molding member and a second primary molding member each having a height of 17 mm x width of 20 mm x length of 20 mm were adopted. As the material of the first primary molding member and the second primary molding member, polyphenylene sulfide (product name: 1130T6) manufactured by Polyplastics Co., Ltd. was adopted. The shape of the convex portion of the first primary molding member and the concave portion of the second primary molding member were the shapes shown in FIG. 11, and the cross-sectional shape perpendicular to the longitudinal direction of the first space was a circle with a diameter of 3 mm. In addition, for the first primary molding member, the maximum width of the convex portion was 1.4 mm, and the maximum height was 1.5 mm. For the second primary molding member, the maximum width of the concave portion was 1.4 mm, and the maximum height was 1.5 mm. The convex portion of the first primary molding member and the concave portion of the second primary molding member were fitted together to form an uneven portion and a first space, and the maximum stress applied to the uneven portion was analyzed assuming that the first space was filled with polyphenylene sulfide (product name: 1130T6) manufactured by Polyplastics Co., Ltd. at 35 MPa. The maximum stress of the analysis model 1 was 102 MPa.

(Analysis model 2)
As the analysis model 2, a first primary molding member and a second primary molding member of the same size and material as those of the analysis model 1 were adopted. The shape of the convex portion of the first primary molding member and the concave portion of the second primary molding member was an arc shape as shown in FIG. 1, and the cross-sectional shape perpendicular to the longitudinal direction of the first space was a circle with a diameter of 1.8 mm. In addition, for the first primary molding member, the maximum width of the convex portion was 0.9 mm, and the maximum height was 0.9 mm. For the second primary molding member, the maximum width of the concave portion was 1.8 mm, and the maximum height was 0.9 mm. The convex portion of the first primary molding member and the concave portion of the second primary molding member were fitted together to form an uneven portion and a first space, and the maximum stress applied to the uneven portion when it was assumed that the first space was filled with polyphenylene sulfide (product name: 1130T6) of Polyplastics Co., Ltd. under the same conditions as those of the analysis model 1 was analyzed. The maximum stress of the analysis model 2 was 39 MPa.

From the results of analytical models 1 and 2, it was inferred that the maximum stress when manufacturing the composite molding of the present disclosure is small, and a composite molding can be obtained in which deformation and destruction of the interlocking uneven portions is suppressed.

The disclosure of Japanese Patent Application No. 2021-010418, filed on January 26, 2022, is incorporated herein by reference in its entirety.
All publications, patent applications, and standards mentioned in this specification are herein incorporated by reference to the same extent as if each individual publication, patent application, or standard was specifically and individually indicated to be incorporated by reference.

10, 10A, 20, 30, 100 Composite molded body 1, 11, 21, 101 First primary molded member 2, 12, 22, 102 Second primary molded member 3, 13, 23, 103 Convex portion 4, 14, 24, 104 Concave portion 5, 105 First space 6, 106 Second space 7, 107 Secondary molded member 8, 108 Flow path 48 Mold 53, 55 Core portion 54, 56 Cavity portion 62 Gate 64 Injection machine

Claims (7)

a first primary molding member having a protruding portion located along a longitudinal direction and a recessed portion adjacent to the protruding portion and located along the longitudinal direction;
a second primary molding member having a first recess located along a longitudinal direction and into which the protrusion is fitted, and a second recess located adjacent to the first recess and along a longitudinal direction and facing the recess of the first primary molding member;
a secondary molding member filling a first space formed by the recess of the first primary molding member facing the second recess when the protrusion of the first primary molding member is fitted into the first recess of the second primary molding member,
A composite molding in which at least a portion of the region on the secondary molding member side in a cross section of the protrusion and a cross section of the first recess perpendicular to the longitudinal direction is arc-shaped. The composite molded body according to claim 1, wherein a second space between the convex portion and the first recess formed on the secondary molded member when the convex portion of the first primary molded member is fitted into the first recess of the second primary molded member is filled with molding material contained in the secondary molded member. The composite molding described in claim 2, wherein the second space is gradually narrowed between the surface of the convex portion and the surface of the first concave portion from the secondary molding member side to the opposite side. A composite molding as described in any one of claims 1 to 3, wherein the entire secondary molding member side is arc-shaped on each of the surfaces of the convex portion and the first concave portion. A composite molding according to any one of claims 1 to 4, wherein the cross section of the first space perpendicular to the longitudinal direction is circular. A composite molding according to any one of claims 1 to 5, wherein the ratio of the maximum width of the first recess to the maximum width of the first space, i.e., maximum width of first recess/maximum width of first space, is 0.2 to 1.5. A composite molding according to any one of claims 1 to 6, wherein the ratio of the maximum depth of the first recess to the maximum height of the first space (maximum depth of the first recess/maximum height of the first space) is 0.1 to 1.