JPWO2012073694A1 - Insert molded body and method of manufacturing insert molded body - Google Patents

Abstract

Provided is an insert molded body including an insert member and a thermoplastic resin member that covers at least a part of the surface of the insert member, and provides a technique for improving the heat shock resistance of the thermoplastic resin member. An insert member, and a thermoplastic resin member that covers at least a part of the surface of the insert member, and when the thermoplastic resin member has one or more welds extending in a predetermined direction, A rough surface is formed in the region immediately below and / or in the vicinity of the region directly below the weld portion. More specifically, the rough surface is formed so that the positions of both ends of the rough surface are substantially coincident with the positions of both ends of the weld portion or more outward.

Description

  The present invention relates to an insert molded body and a method for manufacturing the insert molded body.

  The insert molding method is a molding method in which the insert member is embedded in the resin by taking advantage of the characteristics of the resin and the characteristics of the material of the metal, inorganic solid, etc. (hereinafter, the metal, inorganic solid, etc. may be referred to as the insert member). The obtained insert molded body includes a thermoplastic resin member and an insert member. Insert molded bodies obtained by the insert molding method are used as automobile parts, electrical / electronic parts, OA equipment parts, and the like. Thus, the insert molded body is a useful material used in a wide field.

  However, in the insert molded body, cracking of the thermoplastic resin member immediately after molding, and cracking of the thermoplastic resin member due to temperature change during use may be a problem. This problem is caused by the fact that the expansion rate and shrinkage rate due to temperature change of the thermoplastic resin are different from the expansion rate and shrinkage rate due to temperature change of the insert member. The problem is that when the thermoplastic resin member has a weld portion, there is a stress concentration portion (the thermoplastic resin member has a portion with a large change in thickness, or the insert member has a sharp corner portion. This is likely to occur. For this reason, use, a shape, etc. are restricted in order to prevent an insert molded object from cracking.

  By the way, recently, in the field of automobiles, studies for replacing metal parts around the engine with resin parts have been actively conducted. As one of the studies, studies have been made to use an insert molded body instead of a metal part. Specifically, for ignition-related parts, distributor parts, various sensor parts, various actuator parts, throttle parts, power module parts, ECU parts, various connector parts, etc., metals such as aluminum, copper, iron, brass and various alloys Parts and metal terminals are made of polyarylene sulfide resin (hereinafter sometimes referred to as PAS resin) represented by polyphenylene sulfide (hereinafter abbreviated as PPS) resin, polybutylene terephthalate resin (hereinafter also referred to as PBT resin). Many insert molded products have been studied.

  However, parts around the engine are complicated in structure, the thickness of the resin part is greatly changed, or exposed to an environment (for example, near the engine room) where the temperature changes greatly. As a result, the above-described problem of cracking of the thermoplastic resin member tends to occur. Therefore, there is a need for a technique that can prevent the thermoplastic resin member from cracking even when placed in an environment with a large temperature change. That is, a technique for improving the heat shock resistance of a thermoplastic resin member is required.

  As a resin material (raw material) having excellent heat shock resistance, a resin composition in which a fibrous filler having a flat cross-sectional shape is blended with a polyarylene sulfide resin is disclosed (see Patent Document 1). Further, a resin composition in which a specific impact resistance imparting agent, an inorganic filler, and an aromatic esterified product are blended with polybutylene terephthalate resin is disclosed (see Patent Document 2).

  The resin compositions described in Patent Documents 1 and 2 are excellent as a resin material that improves the heat shock resistance of a thermoplastic resin member. However, in recent years, there has been a strong demand for thinner thermoplastic resin members, and the shape of parts has become complicated, so it is inevitable that weld parts are formed on the thermoplastic resin members, and the above heat shock resistance is further improved. Is required.

JP-A-2005-161693 JP 2008-6829 A

  The present invention has been made in order to solve the above-described problems, and the object thereof includes an insert member and a thermoplastic resin member that covers at least a part of the surface of the insert member, and the thermoplastic resin member described above. Is to provide a technique for improving the heat shock resistance of a thermoplastic resin member in an insert molded body having a weld portion and / or a stress concentration portion.

  The inventors of the present invention have made extensive studies to solve the above problems. As a result, when the insert member and the thermoplastic resin member covering at least a part of the surface of the insert member are provided and the thermoplastic resin member has one or more weld portions extending in a predetermined direction, the surface of the insert member The present inventors have found that the above problem can be solved by forming a rough surface in the region directly below and / or in the vicinity of the region directly below all the welds, and the present invention has been completed. More specifically, the present invention provides the following.

  (1) An insert molded body comprising an insert member and a thermoplastic resin member that covers at least a part of the surface of the insert member, wherein the thermoplastic resin member has a weld portion extending in a predetermined direction. A rough surface extending in the same direction as the weld portion is formed on a part of the surface of the insert member. The rough surface is a region directly below all the weld portions on the surface of the insert member. And / or an insert molded body that is disposed in the vicinity of the region immediately below, and the positions of both ends of the rough surface substantially coincide with the positions of both ends of the weld portion or are more outward.

  (2) An insert molded body comprising an insert member and a thermoplastic resin member covering at least a part of the surface of the insert member, wherein the thermoplastic resin member is expanded and contracted by the thermoplastic resin member. There is one or more stress concentration portions where the generated stress is concentrated, the stress concentration portion extends in a predetermined direction, and a rough surface extending in the same direction as the stress concentration portion is formed on a part of the surface of the insert member. The rough surface is disposed on the surface of the insert member in the region immediately below and / or in the vicinity of the region immediately below the stress concentration portion, and the positions of both ends of the rough surface are the stress concentration portions. An insert molded body which is substantially coincident with the positions of both ends of the outer shape or is more outside.

  (3) Further, the thermoplastic resin member has at least one stress concentration portion where stress generated by expansion and contraction of the thermoplastic resin member is concentrated, the stress concentration portion extends in a predetermined direction, and the stress concentration portion The rough surface extending in the same direction as the portion is disposed on the surface of the insert member in the region immediately below and / or in the vicinity of the region immediately below the stress concentration portion, and the positions of both ends of the rough surface are The insert molded body according to (1), which is substantially coincident with the positions of both ends of the stress concentration portion or on the outer side.

  (4) Further, the thermoplastic resin member has at least one stress concentration portion where stress generated by expansion and contraction of the thermoplastic resin member is concentrated, the stress concentration portion extends in a predetermined direction, and the stress concentration portion The insert molded body according to (1), wherein a position of the part and a position of the weld part substantially coincide with each other.

  (5) In any one of (1) to (4), at least one of the rough surfaces is provided so as to sandwich a region directly below the weld portion and / or the stress concentration portion on the surface of the insert member. The insert molded body described.

  (6) The insert molded body according to any one of (1) to (5), wherein the rough surface is a rough surface formed by a laser.

  (7) The insert molded body according to any one of (1) to (6), wherein the thermoplastic resin member is composed of a crystalline thermoplastic resin composition.

  (8) The insert molded article according to any one of (1) to (7), wherein the crystalline thermoplastic resin composition is a polyarylene sulfide-based resin composition or a polybutylene terephthalate-based resin composition.

  (9) A method of manufacturing an insert molded body comprising an insert member and a thermoplastic resin member covering at least a part of the surface of the insert member, wherein the thermoplastic resin member is a weld extending in a predetermined direction. When the thermoplastic resin member has a weld portion, at least one of the portion and the stress concentration portion, and when the thermoplastic resin member has a weld portion, the region directly below all the weld portions and / or the directly below the surface of the insert member When a rough surface extending in the same direction as the weld portion is formed in the vicinity of the region and the thermoplastic resin member does not have a weld portion, the surface of the insert member is directly below all the stress concentration portions. A rough surface extending in the same direction as the stress concentration portion is formed in the vicinity of the region and / or the region directly below, and the thermoplastic resin member is connected to the weld portion. If the position of the weld portion and the position of the stress concentration portion do not coincide or substantially coincide with each other, the region immediately below all the weld portions on the surface of the insert member and And / or a rough surface extending in the same direction as the weld portion in the vicinity of the region directly below, and extending in the same direction as the stress concentration portion in the region immediately below and / or in the vicinity of the region immediately below the stress concentration portion. A rough surface forming step for forming a rough surface; and an insert member after the rough surface forming step is disposed in a mold, and a molten thermoplastic resin is injected into the mold to at least part of the rough surface. A thermoplastic resin member forming step of forming a thermoplastic resin member on the surface of the insert member so as to cover the surface, and when the thermoplastic resin member has a weld portion, both ends of the rough surface Position is When the thermoplastic resin member does not have a weld part, the positions of both ends of the rough surface are the positions of both ends of the stress concentration part. In the case where the thermoplastic resin member has the weld part and the stress concentration part, and the position of the weld part and the position of the stress concentration part do not match or substantially coincide with each other. These are the manufacturing methods of the insert molding which the position of the both ends of the said rough surface substantially corresponds to the position of the both ends of the said weld part or stress concentration part formed substantially right, or is an outer side.

  (10) Before the rough surface forming step, the thermoplastic resin member of the insert molded body manufactured using the insert member on which the rough surface is not formed is expanded and contracted by heat, and the surface of the thermoplastic resin member is cracked. (9) The method for manufacturing an insert-molded body according to (9), further comprising a crack occurrence position confirmation step for confirming the occurrence position.

  (11) The method for manufacturing an insert molded body according to (10), wherein the rough surface is formed in the vicinity of a position where crack generation is predicted, which is confirmed in the crack generation position confirmation step.

  ADVANTAGE OF THE INVENTION According to this invention, the heat shock resistance of the thermoplastic resin member which comprises an insert molded object can be improved.

It is the figure which showed the concept of hatching width. It is a figure which shows an insert molded object typically, (a) is a perspective view, (b) is a top view of (a). It is a perspective view which shows the insert member 11 typically. It is a schematic diagram which shows a mode that a weld part is formed. BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic diagram of the insert molded object for demonstrating the effect of this invention, (a) is a front view of the insert molded object 1 of this embodiment, (b) is a rough perpendicular | vertical to the predetermined direction where a weld part is extended. It is a front view of an insert molded object when a surface is formed, and (c) is a front view of an insert molded object when a rough surface is not formed on the surface of an insert member. It is a top view which shows typically the specific example of the insert molded object from which the weld part and stress concentration part correspond different from the insert molded object shown in FIG. It is a perspective view which shows typically the specific example of the insert molded object from which the weld part and stress concentration part correspond unlike the insert molded object shown in FIG. It is a perspective view which shows typically an insert molded object in case a thermoplastic resin member has a weld part and a stress concentration part, and the position of a weld part and the position of a stress concentration part do not correspond. It is a perspective view which shows typically the specific example of an insert molded object in the case where the position of a weld part and the position of a stress concentration part do not correspond unlike the insert molded object shown in FIG. It is a perspective view which shows typically an insert molded object in case a thermoplastic resin assembly member does not have a weld part but has only a stress concentration part.

  Hereinafter, embodiments of the present invention will be described. In addition, this invention is not limited to the following embodiment.

The present invention improves the heat shock resistance of a thermoplastic resin member when the thermoplastic resin member has a weld portion or a stress concentration portion in an insert molded body including a thermoplastic resin member and an insert member. After describing the insert member and the thermoplastic resin member, the present invention will be described with reference to the following cases (i) to (iv).
(I) The thermoplastic resin member has a weld portion and a stress concentration portion, and the position of the weld portion and the position of the stress concentration portion coincide with each other (first embodiment).
(Ii) The thermoplastic resin member has a weld portion and a stress concentration portion, and the position of the weld portion does not match the position of the stress concentration portion (second embodiment).
(Iii) The case where the thermoplastic resin assembly member does not have a weld portion but has only a stress concentration portion (third embodiment).
(Iv) A method for producing an insert molded body of the present invention (fourth embodiment).

<Insert member>
As the insert member, a general member conventionally used for an insert molded body can be used. That is, the material constituting the insert member may be a metal, an inorganic material, or an organic material. Specific examples include metals such as steel, cast iron, stainless steel, aluminum, copper, gold, silver, and brass, thermally conductive ceramics, and carbon materials. Moreover, the metal etc. which the metal thin film was formed in the surface can also be used as an insert member. Examples of the metal thin film include a thin film formed by, for example, plating (wet plating, dry plating, etc.). In addition, an insert member may refer to the composite_body | complex which has several metals, resin, etc. as well as single-piece | units, such as a metal and an inorganic material.

  The material constituting the insert member is appropriately determined in consideration of physical properties such as the application and the thermal expansion coefficient of the resin material constituting the resin member.

  The insert member has a rough surface. The method of forming the rough surface is not particularly limited, but the method of forming the rough surface using a laser is preferable because it is simple. The rough surface formation position, rough surface area, rough surface roughness, and the like are determined so as to exhibit the effects of the present invention in relation to the weld portion and stress concentration portion of the thermoplastic resin member described later. The In addition, when forming a rough surface with a laser, processing machine output, hatching width, and laser beam spot diameter are parameters, but processing machine output is 20-40 W, hatching width is 0.02-0.6 mm, laser beam. The spot diameter is usually in the range of about 130 μm. FIG. 1 shows the concept of hatching width (circles in FIG. 1 represent laser irradiation by pulses, and white arrows represent laser scanning directions).

  The shape of the insert member is not particularly limited, and may be a simple shape such as a quadrangular prism shape or a cylindrical shape, or may be a complicated shape such as the shape of a part. The method for forming the insert member is not particularly limited. For example, in the case of metal, the insert member may be manufactured by a method such as die casting, injection molding, press casting, or the like such as machining using a conventionally known machine tool. Can do.

<Thermoplastic resin member>
The material which comprises a thermoplastic resin member is not specifically limited, A crystalline resin composition or an amorphous resin composition may be sufficient. General-purpose thermoplastic resins contained in these resin compositions include polyolefins such as polyethylene (PE), polypropylene (PP), poly-4-methyl-pentene-1, polycyclic olefin, polystyrene (PS), AS resin, ABS. Examples thereof include resins, polyvinyl chloride (PVC), polyacrylonitrile (PAN), (meth) acrylic resins, cellulosic resins, and elastomers. Engineering resins include various aliphatic polyamides such as nylon 6, 6, 6, 12 and 6, 12, or aromatic polyamide (PA), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyethylene Aromatic polyester resins such as phthalate (PEN), polycarbonate (PC), polyacetal (POM), polyphenylene ether (PPE), polyphenylene sulfide (PPS), polysulfone (PSu), polyimide (PI), liquid crystal polyester, liquid crystal amide Etc. In addition, aliphatic polyesters from aliphatic dicarboxylic acids, aliphatic diols, aliphatic hydroxycarboxylic acids or cyclic compounds thereof, and biodegradable resins such as aliphatic polyesters whose molecular weight is increased by diisocyanate, etc. Also good. Two or more kinds of the above-described resins can be used. Further, the resin composition includes a case where the resin composition is substantially made of a crystalline thermoplastic resin such as containing only a small amount of impurities.

  In particular, when the thermoplastic resin member is composed of a crystalline resin composition such as a polyarylene sulfide (PAS) resin composition or a polybutylene terephthalate (PBT) resin composition, the thermoplastic resin member is obtained by crystallization. Swells and shrinks, so that the problem of cracking of the thermoplastic resin member is likely to occur. However, according to the present invention, the problem of cracking of the thermoplastic resin member can be suppressed even when the thermoplastic resin member is made of a crystalline resin composition.

  Among crystalline resin compositions, PAS resin compositions have properties such as high heat resistance, mechanical properties, chemical resistance, dimensional stability, and flame retardancy. The PBT resin has properties such as high mechanical properties, electrical properties, and chemical resistance. These resins having such excellent properties are all applied to automobile parts, electrical / electronic parts and the like. In addition, as a PAS resin which can be used, the PPS resin described in Unexamined-Japanese-Patent No. 2009-132935 is mentioned. Examples of the PBT resin that can be used include PBT resins described in JP-A No. 2006-111893.

  In addition, PAS resins have the disadvantage of poor toughness and weakness. Therefore, when the thermoplastic resin member is formed using the PAS resin, the thermoplastic resin member is particularly easily cracked when the insert molded body is disposed in an environment where the temperature change is large. However, according to the present invention, the problem of cracking of the thermoplastic resin member can be sufficiently suppressed even when a PAS resin is used.

  Moreover, the resin composition which comprises a thermoplastic resin member may contain conventionally well-known additives, such as antioxidant, a stabilizer, a plasticizer, and a pigment, in a resin composition.

  The thermoplastic resin member in the present invention has at least one of a weld portion and a stress concentration portion.

  The weld portion refers to a welded portion formed at the interface between the resin flows by joining a plurality of resin flows in the mold cavity when the thermoplastic resin member is formed. Whether or not the weld portion is formed, the number of the weld portions, and the position of the weld portion depend on the shape of the thermoplastic resin member, the position of the gate of the mold for forming the thermoplastic resin member, and the like.

  Examples of the stress concentration part include a corner part, a notch part, a flaw part, a through hole, a lightening part, and a flow mark part. The position and size of the stress concentration portion may be specified from the shape of the thermoplastic resin member or the like, or may not be specified. When it cannot be specified, it can be specified by actually manufacturing an insert molded body and confirming a fragile portion of the thermoplastic resin member or performing a simulation or the like.

  The shape of the thermoplastic resin member is not particularly limited. A mold having a desired cavity shape is used, an insert member is disposed in the mold, a molten resin composition is poured into the cavity, and the resin composition is solidified, so that a thermoplastic resin having a desired shape is obtained. The resin member can be formed on the insert member.

<First embodiment>
The insert molded body of the first embodiment will be described taking the insert molded body shown in FIG. 2 as an example. FIG. 2 is a view schematically showing the insert molded body of the first embodiment, (a) is a perspective view, and (b) is a plan view of (a). FIG. 3 is a perspective view schematically showing the insert member. FIG. 4 is a schematic diagram showing how the weld portion is formed.

  As shown in FIG. 2, the insert molded body 1 includes an insert member 11 and a thermoplastic resin member 12 (hereinafter simply referred to as a resin member 12), and the resin member 12 covers a part of the insert member 11. It is formed. In the first embodiment, the resin member 12 is formed on the insert member 11 such that the insert member 11 penetrates the upper surface of the rectangular parallelepiped resin member 12. And since it is an insert molded object manufactured with the metal mold | die which has a gate in the bottom face side, as shown to Fig.2 (a), when forming the resin member 12, the weld part 120 arises in four places.

  As shown in FIG. 2, since the insert member 11 has four corner portions, the resin member 12 has four stress concentration portions, and the positions of these stress concentration portions are the same as the positions of the weld portions 120. I'm doing it.

A portion of the insert member 11 that is closer to the bottom surface than the two-dot chain line shown in FIG. 3 is a portion that contacts the resin member 12. A rough surface 110 is formed on the surface in contact with the resin member 12. In the present embodiment, as shown in FIG. 3, a plurality of rectangular (long side L ₁ , short side L ₂ ) rough surfaces 110 are formed on the side surface of the insert member 11.

  The rough surface 110 is formed on the surface of the insert member 11 substantially parallel to a direction in which a weld portion 120 described later extends. “Substantially parallel” includes not only being completely parallel but also being substantially parallel. As long as the effect of the present invention is achieved, the angle formed by the direction in which the weld 120 extends and the direction in which the rough surface 110 extends is not particularly limited, but the angle formed above is preferably 2 ° or less.

In the first embodiment, the rough surface 110 is formed so that two rough surfaces 110 are arranged in parallel near both ends of each side surface, as shown in FIG. The position where the rough surface 110 is formed may be in the vicinity of the region directly below the weld portion 120. For example, there is no problem even if the weld portion 120 is about 2 mm away. On the other hand, the shortest is about 0.1 to 0.2 mm from the viewpoint of operability. In the present embodiment, since the position of the weld portion 120 is on the edge line present in the side surface of the insert member, the "vicinity" is the distance to rough 110 from the ridge line, it is represented by L ₃ in Fig. 3 The In addition, the said distance between the weld part 120 and the rough surface 110 points out the distance between both in the position where the weld part 120 and the rough surface 110 are the closest.

In the present embodiment, in the direction welds 120 extends, the position of both ends of the rough surface 110 is substantially coincides with the position of the ends of the welds 120 (bottom surface of the long sides L _{1 <insert} member 11 from the dashed line Length L _p ). The term “substantially coincides” means that the positions of both ends of the rough surface 110 may be slightly inside the positions of both ends of the weld portion 120 in the predetermined direction. “Slightly inside” means that the length is not particularly limited as long as it does not impair the effects of the present invention, but the difference between the lengths of the ends is within 10% of the long side L _1. Good. More preferably, it is within 5%. In the present invention, it is preferable that the positions of both ends of the rough surface 110 in a predetermined direction are outside the positions of both ends of the weld portion 120 in the predetermined direction.

The length of a short side _{L 2} is preferably 1 / 3-1 / 15 of the length of the sides parallel to the _{L 2} of the insert member 11, more preferably 1 / 5-1 / 10. Rough surface forming a large area as the resin shrinkage is larger is required, it is necessary to longer short side L _2.

  The rough surface 110 improves the adhesion between the resin member 12 and the insert member 11 by an anchor effect.

  The formation method of the rough surface 110 is not specifically limited, A conventionally well-known method is employable. For example, a method of forming a rough surface by laser treatment and a method of forming a rough surface by etching treatment can be mentioned. A method of forming a rough surface by laser treatment is particularly preferable.

  As described above, the resin member 12 has the weld portions 120 at four locations. The weld 120 is formed as follows.

  The insert member 11 on which the rough surface 110 is formed is set in a mold, and a molten thermoplastic resin is injected into the mold and solidified. In the present embodiment, since the molten resin is injected from the direction of the arrow Q in FIG. 4, the flow of the molten resin is divided into Q1 and Q2. And the weld part 120 is formed in the area | region where Q1 and Q2 collide.

  In the present embodiment, the weld portion 120 is formed in a region surrounded by an alternate long and short dash line shown in FIG. 4 (only one location is shown in FIG. 4 for convenience of explanation). The weld portion 120 is a rectangular region. One of the long sides of the weld portion 120 is at a position overlapping the side of the insert member 11. As shown in FIG. 4, the short side of the weld portion 120 overlaps a part of a line that bisects the upper surface and the bottom surface of the resin member 12.

  Then, the effect which the insert molded object of a first embodiment has is explained. In the insert molded body 1 of the first embodiment, a rough surface 110 is formed on a part of the surface of the insert member 11. In the portion where the rough surface 110 is formed, the adhesive force between the insert member 11 and the resin member 12 is increased. As a result, the insert molded body of the first embodiment can suppress the expansion and contraction of the resin member 12 at a portion where the adhesion force is strong even when exposed to an environment with a large temperature change. It is possible to suppress the occurrence of cracks.

  The above effect will be described more specifically. FIG. 5 is a schematic view of an insert molded body for explaining the effect of the present invention, (a) is a front view of the insert molded body 1 of the present embodiment, and (b) is a direction in which the weld portion extends. It is a front view of the insert molded object when the rough surface extended in the direction perpendicular | vertical with respect to is formed, (c) is a front view of the insert molded object when the rough surface is not formed on the surface of the insert member. .

  First, in the insert molded body 1, there is a high possibility that a crack is generated in parallel with the weld portion 120 on the surface of the resin member 12. In the present embodiment, the resin member 12 and the insert member 11 are formed even when the shrinkage of the resin in the direction of the white arrow occurs due to the rough surface 110 as shown in FIG. Since the adhesive force is strong and the contraction movement is inhibited, the amount of contraction can be suppressed. By suppressing the amount of shrinkage, the burden on the resin member 12 is reduced and cracks are less likely to occur. In addition, since the rough surface 110 extends in parallel to the direction in which the weld portion 120 extends, the generation of cracks can be efficiently suppressed while suppressing the area of the rough surface 110 that must be formed. As will be described later, there is a problem if the area of the rough surface 110 is large.

  Further, as shown in FIG. 5A, even if the rough surface 110 formed on the insert member 11 sandwiches the weld portion 120, even if the resin contracts in the direction of the white arrow, The amount of resin shrinkage can be reduced. This is because the insert member 11 and the resin member 12 are firmly adhered to each other by the rough surface 110 formed on the surface of the insert member 11, and the resin near the weld portion 120 is prevented from shrinking. As a result, even if the insert molded body 1 of the present invention is exposed to an environment where the temperature change is large, the amount of shrinkage and expansion of the resin member 12 in the vicinity of the weld portion 120 becomes small. The burden due to expansion can be reduced and the occurrence of cracks can be suppressed.

  Since the positions of both ends of the rough surface 110 in the predetermined direction are substantially coincident with the positions of both ends of the welded portion 120 in the predetermined direction or on the outer side, the occurrence of cracks can be greatly suppressed.

  When the rough surface as shown in FIG. 5B is formed on the insert member 11, for example, only a part of the portion (weld portion 120 in this embodiment) where breakage easily occurs due to contraction is fastened. For the reason, the shrinkage of the resin member 12 can hardly be inhibited, and the effect of improving the heat shock resistance is hardly exhibited. Further, if the shrinkage amount of the resin in the vicinity of the weld portion is sufficiently suppressed with a rough surface extending perpendicularly to the direction in which the weld portion extends as shown in FIG. 5B, the area of the rough surface becomes too large ( That is, it is necessary to form a rough surface on many portions of the surface of the insert member that overlaps the resin member. When the size of the rough surface becomes too large, it tends to lead to a change in physical properties such as electrical conductivity and a decrease in design. In addition, when plating is performed on the surface of the insert member including the rough surface after the formation of the rough surface, plating is formed on the unevenness of the rough surface, and the adhesion between the resin member and the insert member does not tend to increase. .

  As shown in FIG. 5 (c), when the rough surface 110 is not formed on the insert member, the amount of shrinkage and expansion of the resin member cannot be reduced, and the resin member 12 expands and contracts. The burden on the member 12 cannot be suppressed.

  In the present embodiment, the rough surface is formed on the surface of the insert member 11 by laser processing. If the method is a method of forming a rough surface by laser processing, partial processing is also easy, so that the rough surface can be easily formed in a desired range.

  The insert molded body of the first embodiment has been described above. However, an insert molded body in which the weld portion and the stress concentration portion match as shown in FIG. 6A may be used. The insert molded body shown in FIG. 6A has a shape in which a part of the side surface of the columnar insert member 11 is covered with the cylindrical resin member 12, and the side surface of the resin member 12 extends in the direction in which the cylinder extends. Grooves are formed. In the insert molded body shown in FIG. 6A, this groove portion corresponds to a stress concentration portion. Further, a weld 120 is formed along the bottom of the groove. A rough surface 110 is formed in a region of the surface of the insert member 11 immediately below the weld portion 120. Even when the rough surface 110 is formed in the region directly below the weld portion 120, the shrinkage of the resin member 12 at the weld portion 120 is suppressed, and as a result, the same as in the case of the first embodiment shown in FIGS. It is possible to suppress the occurrence of cracks.

  Moreover, as shown in FIG.6 (b), the insert molded object in which a weld part and a stress concentration part correspond may be sufficient. The insert molded body shown in FIG. 6B is different from the insert molded body shown in FIG. 6A only in the shape of the groove of the resin member 12. In the case of the insert molded body shown in FIG. 6B, the corner portion and the thin portion at the bottom of the groove correspond to the stress concentration portion. When the weld 120 is formed at the same position as one of the corners at the bottom of the groove, the rough surface 110 is formed on the surface of the insert member in the region directly below or near the region directly below the weld 120. do it. In addition, since the insert molded body shown in FIG. 6B has a plurality of stress concentration portions, even if the rough surface 110 is formed in the region directly below or near the region immediately below the stress concentration portion on the surface of the insert member. Good. If the rough surface 110 is formed also in the region directly under the stress concentration portion or in the vicinity thereof, the occurrence of cracks in the stress concentration portion can be suppressed.

  Moreover, as shown in FIG.6 (c), the insert molded object in which a weld part and a stress concentration part correspond may be sufficient. The insert molded body shown in FIG. 6C is that the resin member 12 does not have a groove, and the center axis of the cylindrical resin member 12 is shifted from the center axis of the columnar insert member 11. It is different from the insert molded body shown in FIG. The thinnest portion of the resin member 12 is a stress concentration portion, and the weld portion 120 is formed so as to coincide with the position of the stress concentration portion. And the rough surface 110 is formed in the area | region directly under the weld part 120 in the surface of an insert member.

  Moreover, as shown in FIG. 7, an insert molded body in which the weld portion and the stress concentration portion coincide with each other may be used. The insert member 11 of the insert molded body shown in FIG. 7 has a rectangular parallelepiped shape. Moreover, the resin member 12 of the insert molded body shown in FIG. 7 wraps the rectangular parallelepiped insert member 11, and is formed so that the entire insert molded body has a rectangular parallelepiped shape. The resin member 12 has six portions formed on the side surface. The stress concentration part of the resin member 12 of the insert molded body shown in FIG. 7 is indicated by a dot pattern. Further, the weld portion 120 is indicated by a broken line. As shown in FIG. 7, since the position of the weld 120 overlaps with the stress concentration area, it can be said that the position of the weld 120 matches the position of the stress concentration area.

<Second embodiment>
FIG. 8 is a perspective view schematically showing the insert molded body of the second embodiment. As shown in FIG. 8, the resin member 12 is formed so as to cover a part of the side surface of the quadrangular columnar insert member 11. Four corner portions present on the side surface of the insert member 11 correspond to the stress concentration portion. Then, by adjusting the position of the gate, the weld portion 120 is formed between the stress concentration portion and the stress concentration portion so as to be substantially parallel to the stress concentration portion. In the second embodiment, on the surface of the insert member 11, the rough surface 110 is formed in the region immediately below the weld portion 120 or in the vicinity of the region immediately below, in the region immediately under the stress concentration portion or in the vicinity of the region below, The heat shock resistance of the resin member is improved. Note that the shape of the insert member 11 of the second embodiment is the same as that of the insert member 11 of the first embodiment, and the surface of the insert member 11 is also rough in the region directly below the weld portion 120 or in the vicinity of the region directly below. Except that the surface 110 is formed, it is the same as the insert member used in the first embodiment.

  Moreover, as shown in FIG. 9, an insert molded body in which the weld portion 120 and the stress concentration portion do not coincide with each other may be used. The shape of the insert molded body shown in FIG. 9 is the same as that of the insert molded body shown in FIG. 7, except that the position of the weld portion 120 (broken line) does not overlap the stress concentration portion (dot portion). Different from insert molding. In the case of the insert molded body shown in FIG. 9, a rough surface is formed in the region directly below or near the region below the weld 120, the region directly below or near the region immediately below the stress concentration portion, and the resin member 12 Improves heat shock resistance.

<Third embodiment>
FIG. 10 is a perspective view showing an insert molded body of the third embodiment. The shape of the insert molded body shown in FIG. 10 is the same as that of the insert molded body shown in FIG. 8, but differs from the insert molded body shown in FIG. 8 in that the resin member 12 does not have the weld portion 120. The weld 120 is not formed by adjusting the position of the gate to the bottom surface side of the insert molded body. In the insert molded body of the third embodiment, the rough surface 110 is formed on the surface of the insert member in the region directly below or near the region immediately below the stress concentration portion.

<Fourth embodiment>
The fourth embodiment is a method for manufacturing an insert molded body of the present invention. The method of manufacturing an insert molded body according to the fourth embodiment includes a rough surface forming step of forming a rough surface on the surface of the insert member, and forming a thermoplastic resin member on at least a part of the surface of the insert member on which the rough surface is formed. A thermoplastic resin member forming step (sometimes referred to as a resin member forming step in this specification).

  When the resin member has a weld portion, the rough surface on the surface of the insert member is formed in the region immediately below and / or in the vicinity of the region immediately below all the weld portions, and the resin member does not have the weld portion. Is formed in the region directly below and / or in the vicinity of the region directly below all the stress concentration portions, and the thermoplastic resin member has a weld portion and a stress concentration portion. If the position of the portion does not match or substantially does not match, the region immediately below and / or the region immediately below all the welds on the surface of the insert member, and the region directly below all the stress concentration portions and / or It is formed in the vicinity of the region immediately below. In addition, about the specific content of a rough surface and an insert member, since it is as having demonstrated in 1st embodiment-3rd embodiment, the description is abbreviate | omitted.

  About a weld part, a stress concentration part, etc., since it is as having demonstrated in 1st embodiment-3rd embodiment, the description is abbreviate | omitted. As described above, the position where the weld portion is formed and whether the weld portion is formed are determined by the position of the gate of the mold to be used.

  According to the method for manufacturing an insert molded body of this embodiment, even if the insert molded body is exposed to an environment with a large temperature change, the shrinkage and expansion of the resin can be reduced. This is because the movement of the resin contraction and expansion is hindered by the presence of the portion where the adhesion force between the insert member 11 and the resin member 12 is increased. As a result, the heat shock resistance of the resin member is improved, and the occurrence of cracks due to shrinkage and expansion of the resin member can be suppressed.

  In addition, in the manufacturing method of this invention, it is preferable to provide the crack generation position confirmation process before a rough surface formation process. The crack generation position confirmation process is a process in which the thermoplastic resin member of an insert molded body manufactured using an insert member with no rough surface is expanded and contracted by heat, and the crack generation position on the surface of the thermoplastic resin member is confirmed. It is a process to do. By providing this step, even if the position where the crack is likely to occur (the position of the stress concentration portion) is not known in advance, the position can be confirmed from the crack generation position.

  Therefore, by confirming the position of the stress concentration portion as described above and forming a rough surface on the surface of the insert member immediately below the stress concentration portion or in the vicinity of the region immediately below, the position of the stress concentration portion is determined. Even if it is not clear beforehand, the heat shock resistance of the resin member can be enhanced.

  EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto.

<Example 1>
The insert molded body shown in FIG. 2 was manufactured by the method shown below using PPS resin for forming the thermoplastic resin member and using SUS (S52C) as the insert member. The dimensions of the insert member are 14 mm long × 14 mm wide × 46 mm high. As shown in FIG. 3, a rough surface of L ₁ = 22 mm and L ₂ = 2 mm is formed on the side surface of the insert member that comes into contact with the resin member by laser processing with a laser beam spot diameter of about 130 μm. did. It should be noted that the distance _{L 3} was 2mm. The rough surface was formed on all four side surfaces (total of 8 locations).

  The resin molded body was placed in a mold, and a molten PPS resin was poured into the mold to produce the insert molded body of the example. Specifically, it was produced by the following method. Using resin pellets (heat shock grade marketed product containing elastomer “FN1150T7”), cylinder temperature is 320 ° C., mold temperature is 150 ° C., injection time is 0.84 seconds, and cooling time is 40 seconds. 22 mm, 22 mm wide, 28 mm high inside a prism with a length of 14 mm, a width of 14 mm, and a height of 46 mm, a metal mold) is insert injection molded so that the minimum thickness of the resin part is 1 mm. A molded article was produced. In addition, in order to evaluate heat shock resistance, which will be described later, a total of three identical molded inserts were produced.

<Comparative Example 1>
An insert molded body of Comparative Example 1 was produced in the same manner as in Example 1 except that a rough surface was not formed on the surface of the insert member. In addition, in order to evaluate heat shock resistance, which will be described later, a total of three identical molded inserts were produced.

<Comparative example 2>
The same method as in Example 1 except that the rough surface extends in a direction perpendicular to the direction in which the weld portion extends, passes through the central portion of the weld portion, and the size of the rough surface is 2 mm wide × full circumference. The insert molded body of Comparative Example 2 was manufactured. In addition, in order to evaluate heat shock resistance, which will be described later, a total of three identical molded inserts were produced.

<Evaluation>
The heat shock resistance was evaluated by the following method. The process of heating 3 obtained insert molded bodies at 180 ° C. for 2 hours using a thermal shock tester, cooling to −40 ° C., cooling for 2 hours, and further raising the temperature to 180 ° C. is one cycle. The heat shock resistance test was performed, and the number of cycles until cracks occurred in the molded product was measured while taking out and checking every 20 cycles to evaluate the heat shock resistance. The evaluation results are shown in Table 1.

  From Table 1, it was confirmed that the heat shock resistance is improved by forming a rough surface extending in the same direction as the weld portion in the region directly below the weld portion or in the vicinity of the region directly below the insert member surface. . It was also confirmed that heat shock resistance was not improved even when a rough surface extending in a direction perpendicular to the direction in which the weld portion extends was formed.

<Example 2>
The insert molded body shown in FIG. 10 was manufactured by the method shown below using PBT resin for forming the thermoplastic resin member and using SUS (S52C) as the insert member. The dimensions of the insert member are 14 mm long × 14 mm wide × 46 mm high. As shown in FIG. 3, a rough surface of L ₁ = 22 mm and L ₂ = 2 mm is formed on the side surface of the insert member that comes into contact with the resin member by laser processing with a laser beam spot diameter of about 130 μm. did. The distance _{L 3} was 100 [mu] m. The rough surface was formed on all four side surfaces (total of 8 locations).

  The resin molded body was placed in a mold, and a molten PBT resin was poured into the mold to produce the insert molded body of the example. Specifically, it was produced by the following method. Using resin pellets (commercially available product “DX733LD”), a cylinder temperature of 250 ° C., a mold temperature of 80 ° C., an injection time of 0.8 seconds, a cooling time of 10 seconds, and a test piece molding die (length 15.4 mm, width 15.4 mm, 28 mm high inside a prism with a length of 14 mm, a width of 14 mm, and a metal core with a height of 46 mm, insert injection molding so that the minimum thickness of the resin part is 0.7 mm, An insert molded product was produced. In addition, for the evaluation of heat shock resistance, which will be described later, a total of five insert molded bodies were manufactured.

<Comparative Example 3>
An insert molded body of Comparative Example 3 was produced in the same manner as in Example 2 except that the rough surface was not formed on the surface of the insert member. In addition, for the evaluation of heat shock resistance, which will be described later, a total of five insert molded bodies were manufactured.

表２から、応力集中部と同じ方向に延びる粗面を、インサート部材の表面における応力集中部の真下の領域又は真下の領域の近傍に形成することで、耐ヒートショック性が向上することが確認された。<Evaluation>
The heat shock resistance was evaluated by the following method. A process of heating 5 obtained insert molded bodies at 140 ° C. for 1.5 hours using a thermal shock tester, lowering to −40 ° C., cooling for 1.5 hours, and further raising the temperature to 140 ° C. The heat shock resistance test was performed with 1 cycle, and the number of cycles until cracks occurred in the molded product was measured while taking out and checking every 20 cycles, and the heat shock resistance was evaluated. The evaluation results are shown in Table 2.

From Table 2, it is confirmed that the heat shock resistance is improved by forming a rough surface extending in the same direction as the stress concentration portion in the region immediately below the stress concentration portion or in the vicinity of the region immediately below the insert member surface. It was done.

DESCRIPTION OF SYMBOLS 1 Insert molded object 11 Insert member 110 Rough surface 12 Resin member 120 Weld part

Claims (11)

An insert molded body comprising an insert member and a thermoplastic resin member covering at least a part of the surface of the insert member,
The thermoplastic resin member has one or more welds extending in a predetermined direction,
A rough surface extending in the same direction as the weld portion is formed on a part of the surface of the insert member,
The rough surface is disposed on the surface of the insert member in the region directly below all the welds and / or in the vicinity of the region immediately below.
The insert molded body in which the positions of both ends of the rough surface are substantially the same as the positions of both ends of the weld portion or are on the outer side. An insert molded body comprising an insert member and a thermoplastic resin member covering at least a part of the surface of the insert member,
The thermoplastic resin member has at least one stress concentration portion where stress generated by expansion and contraction of the thermoplastic resin member is concentrated, and the stress concentration portion extends in a predetermined direction,
A rough surface extending in the same direction as the stress concentration portion is formed on a part of the surface of the insert member,
The rough surface is disposed on the surface of the insert member in a region immediately below all stress concentration portions and / or in the vicinity of the region immediately below.
The insert molded body in which the positions of both ends of the rough surface are substantially the same as the positions of both ends of the stress concentration portion or are on the outer side. Furthermore, the thermoplastic resin member has one or more stress concentration portions where stress generated by expansion and contraction of the thermoplastic resin member is concentrated, and the stress concentration portion extends in a predetermined direction,
A rough surface extending in the same direction as the stress concentration portion is disposed on the surface of the insert member in a region directly below all stress concentration portions and / or in the vicinity of the region immediately below.
The insert molded body according to claim 1, wherein positions of both ends of the rough surface are substantially coincident with positions of both ends of the stress concentration portion or more outside. Furthermore, the thermoplastic resin member has one or more stress concentration portions where stress generated by expansion and contraction of the thermoplastic resin member is concentrated, and the stress concentration portion extends in a predetermined direction,
The insert molded body according to claim 1, wherein the position of at least one of the stress concentration portions and the position of the weld portion substantially coincide with each other.   The insert molded body according to any one of claims 1 to 4, wherein at least one of the rough surfaces is provided so as to sandwich a region immediately below the weld portion and / or the stress concentration portion on the surface of the insert member. .   The insert molded body according to any one of claims 1 to 5, wherein the rough surface is a rough surface formed by a laser.   The insert molded body according to any one of claims 1 to 6, wherein the thermoplastic resin member is composed of a crystalline thermoplastic resin composition.   The insert molded body according to any one of claims 1 to 7, wherein the crystalline thermoplastic resin composition is a polyarylene sulfide-based resin composition or a polybutylene terephthalate-based resin composition. An insert molded body comprising: an insert member; and a thermoplastic resin member that covers at least a part of the surface of the insert member.
The thermoplastic resin member has one or more of at least one of a weld portion extending in a predetermined direction and a stress concentration portion extending in a predetermined direction,
When the thermoplastic resin member has a weld portion, a rough surface extending in the same direction as the weld portion in the region directly below and / or in the vicinity of the region immediately below the weld portion on the surface of the insert member. Form the
In the case where the thermoplastic resin member does not have a weld portion, the same area as the stress concentration portion in the area directly below and / or in the vicinity of the area immediately below the stress concentration portion on the surface of the insert member. Forming a rough surface extending in the direction,
In the case where the thermoplastic resin member has the weld part and the stress concentration part, and the position of the weld part and the position of the stress concentration part do not match or substantially match, in the surface of the insert member, Rough surfaces extending in the same direction as the welds in the vicinity of all the welds and / or in the vicinity of the areas directly under the welds, and the areas directly under the stresses and / or the areas under the stresses A rough surface forming step of forming a rough surface extending in the same direction as the stress concentration portion,
The insert member after the rough surface forming step is placed in a mold, and a thermoplastic resin member is injected into the mold so as to cover at least a part of the rough surface. A thermoplastic resin member forming step formed on the surface of the insert member,
When the thermoplastic resin member has a weld portion, the positions of both ends of the rough surface are substantially coincident with the positions of both ends of the weld portion or more outside.
When the thermoplastic resin member does not have a weld portion, the positions of both ends of the rough surface are substantially coincident with the positions of both ends of the stress concentration portion, or more outside.
In the case where the thermoplastic resin member has the weld part and the stress concentration part, and the position of the weld part and the position of the stress concentration part match or do not substantially match, the positions of both ends of the rough surface These are the manufacturing methods of the insert molded object which are substantially the same as the position of the both ends of the said weld part or stress concentration part formed substantially right, or more outside.   Before the rough surface forming step, the thermoplastic resin member of the insert molded body manufactured using the insert member on which the rough surface is not formed is expanded and contracted by heat, and the crack occurrence position on the surface of the thermoplastic resin member is determined. The manufacturing method of the insert molded object of Claim 9 further equipped with the crack generation position confirmation process to confirm.   The said rough surface is a manufacturing method of the insert molded object of Claim 10 formed in the vicinity of the position which generation | occurrence | production of the crack confirmed which was confirmed in the said crack generation position confirmation process.

Images