Metal / resin composite molded body and production method for metal / resin composite molded body

Abstract

A plurality of terminal grooves (38) are formed at a middle portion (36) of a metal terminal (30) by stamping terminal recesses (43) and terminal protrusions (41) around the entire circumference. The terminal grooves (38) are arranged in the longitudinal direction of the middle portion (36). The terminal recesses (43) are recessed from not-coined surfaces (31, 35) of the middle portion (36). The terminal protrusions (41) protrude from the not-coined surfaces (31, 35) of the middle portion (36). The present invention thereby makes it possible for the sealing properties of the grooves to be maintained when the grooves are coined in the metal terminal.

Description

Metal-resin composite molding and method for manufacturing metal-resin composite molding

[0001] This specification discloses a metal-resin composite molded product and a method for producing the same.

[0002] Patent Document 1 discloses a metal-resin composite molded body, which is formed by insert molding using, for example, a metal terminal as an insert part.

[0003] Both ends of the metal terminal are exposed from the resin, and the middle portion is embedded in the resin. One end of the metal terminal is connected to a substrate, for example. The other end of the metal terminal is placed in an environment exposed to liquid, such as the stator of a motor. In the embedded portion of the metal terminal (i.e., the middle portion), multiple grooves are formed along the longitudinal direction to provide sealing properties. The grooves are formed around the entire circumference of the metal terminal.

[0004] Patent No. 5667652

[0005] However, when attempting to form a groove in a metal terminal by coining using a press molding machine, there is a risk of material loss occurring during the press process, which can cause walls to form within the groove, blocking the entire cross section of the groove and making it difficult to maintain the sealing properties of the groove.

[0006] Therefore, this specification discloses a metal-resin composite molded body and a method for manufacturing the same that can maintain the sealing properties of a groove when the groove is formed in a metal terminal by coining.

[0007] This specification discloses a metal-resin composite molded body. The molded body includes a flat metal terminal and a resin part. The resin part exposes both ends of the metal terminal and embeds the middle portion of the metal terminal. The middle portion of the metal terminal has grooves formed by forming recesses and protrusions around the entire circumference by stamping, and multiple grooves are arranged along the longitudinal direction of the middle portion. The recesses are recessed from the non-coined surface of the middle portion. The protrusions protrude from the non-coined surface of the middle portion.

[0008] According to the above configuration, the excess material generated when the recess is formed can be used to increase the height of the protrusion.

[0009] In the above configuration, the side surfaces of the grooves formed by the recesses and protrusions may extend perpendicular to the non-coining surface.

[0010] According to the above configuration, when the resin filled in the recess undergoes thermal expansion and contraction, the interface between the resin and the metal terminal is sealed by the side surface and the resin.

[0011] In the above configuration, the protruding height of the convex portion from the non-coining surface may be smaller than the recessed depth from the non-coining surface of the concave portion.

[0012] According to the above configuration, the amount of material that escapes to the convex portions can be reduced compared to the amount of material that escapes when the concave portions are stamped. By filling the escape material used to raise the height of the convex portions at a high density, the shape of the mold in the convex portions can be transferred to the escape material with high precision.

[0013] In the above configuration, the groove may be formed around the entire circumference of the metal terminal by a first groove portion and a second groove portion. The first groove portion is formed on both sides of the metal terminal in the thickness direction. The second groove portion is formed on both sides of the metal terminal in the width direction and connected to the first groove portion. One of the first groove portion and the second groove portion is deeper than the other.

[0014] Coining may cause material to escape into the groove, forming a plate-like portion. If one of the first groove portion and the second groove portion is coined after the other is coined, a plate-like portion may be formed in the groove that was coined first due to material escape. Therefore, the relatively deep groove is coined first, and then the relatively shallow groove is coined. At this time, a relatively small amount of material escapes into the relatively deep groove, forming a plate-like portion. As a result, the entire cross section of the deep groove is prevented from being blocked by a relatively small amount of material escape.

[0015] In the above configuration, the first groove may be deeper than the second groove, and in this case, the plate-like portion is disposed at the end of the first groove in the longitudinal direction, with the plate-like portion lying on the bottom surface.

[0016] According to the above configuration, even if a plate-like portion is formed in the first groove portion of the deep groove, by arranging the plate-like portion in a lying position, clogging of the first groove portion is suppressed.

[0017] In the above configuration, at least some of the plurality of grooves may be arranged at different pitches.

[0018] According to the above-described configuration, sealing properties can be exhibited in response to various expansion and contraction states of the resin part and the metal terminal.

[0019] This specification also discloses a method for manufacturing a metal-resin composite molded body. The metal-resin composite molded body includes a flat metal terminal and a resin part. The resin part exposes both ends of the metal terminal and embeds the middle portion of the metal terminal. In the method for manufacturing a metal-resin composite molded body, both thickness-wise and width-wise sides of the middle portion of the metal terminal are coined using a mold with a concave-convex shape formed on the pressing surface. This forms a groove around the entire circumference of the middle portion. In addition, during the coining process, the position where the bottom surface of the recess on the pressing surface of the mold is recessed along the coining direction relative to the non-coined surface of the middle portion of the metal terminal is set as the coining stop position.

[0020] According to the above configuration, the excess material generated when the recess is formed can be used to increase the height of the protrusion.

[0021] In the above configuration, the distance between the bottom surface of the recess and the non-coining surface at the coining stop position may be shorter than the distance between the non-coining surface and the top surface of the protrusion on the pressing surface.

[0022] According to the above-mentioned configuration, the amount of material lost to the protrusions can be reduced compared to the amount of material lost when the recesses are stamped. The mold corresponding to the protrusions is densely filled with the material lost, so that the shape of the mold is transferred to the material lost with high precision.

[0023] In the above configuration, the mold may include a first mold, a second mold, and a third mold. The first mold forms a concave-convex shape on the pressing surface. The second mold and the third mold form concave-convex shapes with the same groove width and pitch as the first mold on the pressing surface. The coining process includes first groove processing, second groove processing, and bending. In the first groove processing, the first mold coins both thickness-wise surfaces of the intermediate portion of the metal terminal to form a first groove in the intermediate portion. In the second groove processing, after the first groove processing, the second mold coins both width-wise surfaces of the intermediate portion of the metal terminal to form a second groove connected to the first groove in the intermediate portion. In the bending process, after the second groove processing, the third mold bends the plate-shaped portion formed at the longitudinal end of the first groove so as to lie on the bottom surface of the first groove.

[0024] According to the above configuration, even if a plate-like portion is formed in the groove by the relief during groove processing, the plate-like portion is laid down in the groove by the bending process.

[0025] In the above configuration, the first mold may have deeper concave and convex grooves than the second mold.

[0026] According to the above configuration, by forming a plate-shaped portion in the groove of the metal terminal formed by the first mold, i.e., in a relatively deep groove, the entire cross section of the groove is prevented from being blocked.

[0027] According to the metal-resin composite molded product and the method for manufacturing the same disclosed in this specification, when a groove is formed in a metal terminal by coining, the sealing properties of the groove can be maintained.

[0028] Fig. 1 is a perspective view illustrating a metal resin composite molded product according to the present embodiment; Fig. 2 is a perspective view illustrating a metal terminal; Fig. 3 is a cross-sectional view illustrating the sealing effect of a groove; Fig. 4 is a perspective view illustrating a mold used to form a groove in a metal terminal; Fig. 5 is a cross-sectional view illustrating processing of a first groove portion; Fig. 6 is a perspective view illustrating processing of a second groove portion; Fig. 7 is a perspective view illustrating a bending process; Fig. 8 is a partially cross-sectional perspective view illustrating a groove structure; Fig. 9 is a cross-sectional view illustrating an example of an uneven pitch groove.

[0029] 1. Metal-Resin Composite Molded Product Fig. 1 illustrates a metal-resin composite molded product 10 according to this embodiment. Fig. 2 illustrates a metal terminal 30.

[0030] 1 to 9 show a Cartesian coordinate system, which is composed of a T-axis, an L-axis, and a W-axis.

[0031] The T-axis is the thickness direction axis. The T-axis is set based on the thickness direction of the intermediate portion 36 of the metal terminal 30. For example, the T-axis extends perpendicular to the flat surface 31 of the intermediate portion 36. The W-axis is the width direction axis. The W-axis is set parallel to the width direction of the metal terminal 30. Furthermore, the L-axis is the longitudinal direction axis of the intermediate portion 36.

[0032] The metal-resin composite molded product 10 includes a resin part 20 and a metal terminal 30. The metal-resin composite molded product 10 is manufactured by, for example, insert molding. The resin part 20 is, for example, a plate-shaped part. The resin part 20 is made of, for example, a highly heat-resistant crystalline thermoplastic resin such as PPS resin or PPA resin.

[0033] A terminal block (not shown), for example, is mounted on the upper surface 22 of the resin part 20. Therefore, the upper surface 22 is an area that should not be exposed to water. On the other hand, the lower surface 24 is connected to, for example, a pump stator and is an area that is exposed to water.

[0034] The metal terminals 30 have ends exposed from the upper surface 22 and the lower surface 24 of the resin component 20. The metal terminals 30 have a flat plate shape and are also called blanks. The metal terminals 30 are made of a conductive material such as copper, brass, or iron.

[0035] 1 and 2, both ends of the metal terminal 30 in the longitudinal direction are bent into a generally S-shape. The metal terminal 30 has a first end 32, a second end 34, and an intermediate portion 36.

[0036] A first end 32 at one longitudinal end of the metal terminal 30 is exposed from the upper surface 22 of the resin part 20. For example, the first end 32 is connected to a terminal block. A second end 34 at the other longitudinal end of the metal terminal 30 is exposed from the lower surface 24 of the resin part 20. For example, the second end 34 is connected to a stator of a motor.

[0037] An intermediate portion 36 is formed between the first end portion 32 and the second end portion 34. The intermediate portion 36 is embedded in the resin part 20. If a gap is formed at the interface between the intermediate portion 36 and the resin part 20, liquid may leak from the lower surface 24 (wet area) of the resin part 20 to the upper surface 22 (water-protected area). Therefore, a terminal groove 38 is formed in the intermediate portion 36.

[0038] 2. Groove Shape The terminal groove 38 is formed around the entire circumference of the intermediate portion 36 of the metal terminal 30. The terminal groove 38 is formed in an annular shape with the longitudinal axis L as its central axis. A plurality of terminal grooves 38 are formed in the intermediate portion 36 along the longitudinal direction.

[0039] 8 , the terminal groove 38 includes a first groove portion 40 and a second groove portion 50. The first groove portion 40 is formed on both thickness-wise surfaces of the metal terminal 30. The second groove portion 50 is formed on both width-wise surfaces of the metal terminal 30. The first groove portion 40 and the second groove portion 50 both extend in a straight line. The first groove portion 40 and the second groove portion 50 are connected to each other, thereby forming the terminal groove 38 around the entire circumference (i.e., annularly) of the intermediate portion 36.

[0040] 2 illustrates an enlarged cross-sectional view (A-A cross-sectional view) of the terminal groove 38. A plurality of terminal protrusions 41 and terminal recesses 43 are formed in the terminal groove 38. The terminal protrusions 41 protrude from the flat plate surface 31 (non-coining surface) of the intermediate portion 36. The terminal recesses 43 are recessed from the flat plate surface 31 (non-coining surface).

[0041] For example, the protruding height H20 of the terminal protrusion 41 is smaller than the recessed depth H21 of the terminal recess 43 (H20 < H21). As will be described later, the terminal protrusion 41 is formed by the relief material that occurs when the terminal recess 43 is coined.

[0042] FIG. 3 illustrates a T-L cross section of the first groove portion 40. The T-L cross section is the same cross section as the A-A cross section in FIG. 2. Except for the groove depth of the first groove portion 40, the second groove portion 50 also has the same cross-sectional shape as that shown in FIG. 3. In other words, the second groove portion 50 has the same groove width and pitch as the first groove portion 40. Here, even if there is a difference in groove width or groove pitch, it is considered to be the same as long as the difference falls within the tolerance. Furthermore, the groove pitch refers to the distance between adjacent terminal grooves 38, 38.

[0043] The first groove 40 and the second groove 50 are both rectangular U-shaped grooves. Referring to Figures 3 and 8, the first groove 40 has a bottom surface 46 and a pair of side surfaces 44 extending from the bottom surface 46. Similarly, the second groove 50 has a bottom surface 56 and a pair of side surfaces 54 extending from the bottom surface. Referring to Figure 3, adjacent terminal grooves 38 are connected by the top surface 42.

[0044] The side surfaces 44, 44 and the side surfaces 54, 54 all extend perpendicular to the flat plate surfaces 31, 35 (non-pressure surfaces, see FIG. 2 ). Note that perpendicular includes being substantially perpendicular. For example, if the angles of the side surfaces 44, 44 and the side surfaces 54, 54 with respect to the flat plate surfaces 31, 35 are within the range of 80° to 100°, the side surfaces 44, 44 and the side surfaces 54, 54 are considered to be perpendicular to the flat plate surfaces 31, 35.

[0045] The resin part 20 is filled into the terminal groove 38. The filling parts 23 (shown as 23A and 23B in FIG. 3) provide a sealing effect at the interface between the resin part 20 and the metal terminal 30.

[0046] The metal terminal 30 and the resin part 20 have different linear expansion coefficients. For example, the linear expansion coefficient of copper is 17.7×10 ―６ / °C, whereas the linear expansion coefficient of PPS resin is 4.9 x 10 ―５ / ° C. In other words, in a high temperature environment, the resin part 20 expands more than the metal terminal 30.

[0047] At this time, as the filling portion 23A thermally expands, it presses the side surfaces 44A, 44B of the terminal groove 38 as shown by the arrow (1). Then, due to the elasticity of the resin part 20, the side surfaces 44A, 44B are sealed.

[0048] Furthermore, in a low-temperature environment, the resin part 20 shrinks more than the metal terminal 30. At this time, as illustrated by the arrow (2), the filling portions 23A and 23B pressurize the side surfaces 44B and 44C. The elasticity of the resin part 20 then seals the side surfaces 44B and 44C.

[0049] To achieve this sealing effect, the side surfaces 44, 54 (see FIG. 8) of the terminal groove 38 extend perpendicular to the flat plate surfaces 31, 35 (see FIG. 2). As described above, the angles of the side surfaces 44, 44 and the side surfaces 54, 54 with respect to the flat plate surfaces 31, 35 are in the range of 80° to 100°.

[0050] In FIG. 3, the multiple terminal grooves 38 are formed with the same groove width and the same pitch. However, the groove width and groove pitch may vary across the multiple terminal grooves 38. For example, FIG. 9 illustrates terminal grooves 38A, 38B, and 38C with different groove widths. The groove width W1 of terminal groove 38A, the groove width W2 of terminal groove 38B, and the groove width W3 of terminal groove 38C have a relationship of W1 > W2 > W3. For example, by providing multiple terminal grooves 38 with different groove widths and groove pitches, the above-mentioned sealing effect can be obtained in various temperature environments.

[0051] 8, the groove depths of the first groove portion 40 and the second groove portion 50 may be different. In other words, one of the first groove portion 40 and the second groove portion 50 is deeper than the other. For example, as shown by depths H5 and H6 in FIG. 8, the first groove portion 40 is deeper than the second groove portion 50.

[0052] As shown in FIG. 6 , which will be described later, a plate-like portion 45 may be generated when forming the terminal groove 38 by coining. By forming a relatively deep groove (first groove portion 40) and then forming a relatively shallow groove (second groove portion 50), the plate-like portion 45 is generated at the longitudinal end of the deep groove. Because only a small amount of material loss is required when coining a relatively shallow groove, the height of the plate-like portion 45 is kept less than the depth of the deep groove. Therefore, the deep groove (first groove portion 40) is prevented from being blocked by the plate-like portion 45 across the entire cross section.

[0053] Furthermore, the plate-like portion 45 is laid down by a bending process described later. By laying the plate-like portion 45 down on the bottom surface 46 of the relatively deep groove (first groove portion 40), a sufficient groove depth can be obtained even if the plate-like portion 45 adds height.

[0054] 4 illustrates an example of a mold for forming the terminal groove 38 in the metal terminal 30. In the metal terminal 30 according to this embodiment, the terminal groove 38 is formed by press molding. More specifically, the terminal groove 38 is formed by coining, a coining process.

[0055] As examples of molds for forming the terminal grooves 38, first molds 80A and 80B, second molds 60A and 60B, and third molds 70A-70D are shown in FIG.

[0056] The first molds 80A and 80B coin both thickness-wise surfaces of the intermediate portion 36 of the metal terminal 30. A concave-convex shape (concave-convex grooves) is formed on the pressing surfaces 82A and 82B of the first molds 80A and 80B. The concave-convex grooves on the pressing surface 82A have the same groove width and pitch as the concave-convex grooves on the pressing surface 82B.

[0057] Fig. 5 illustrates a T-L cross section of the first mold 80A. The first mold 80B also has a cross-sectional shape similar to that shown in Fig. 5. In the following description of the first mold 80A, the structure of the first mold 80B will be explained by replacing the suffix "A" with "B."

[0058] A plurality of die projections 81A and die recesses 83A are formed on the pressing surface 82A of the first die 80A. Figure 5 shows an example of a cross section of the first die 80A and the metal terminal 30 during the stamping process. The stamping stroke is shown as coining stop positions L11 and L12. The top surface 84A of the die projections 81A is pressed in to the coining stop position L11. The bottom surface 85A of the die recesses 83A moves to the coining stop position L12.

[0059] Here, the coining stop position L12 is located in front of the flat plate surface 31 (non-coining surface) of the intermediate portion 36 of the metal terminal 30. In other words, the coining stop position L12 is a position floating above the flat plate surface 31. That is, the bottom surface 85A of the mold recess 83A is set at a position receding from the flat plate surface 31 (non-coining surface) of the intermediate portion 36 along the coining direction, so that the coining stop position L12 is set.

[0060] By setting the position in this way, as will be described later, the excess material generated by coining the mold protrusion 81A flows into the mold recess 83A during coining. In other words, the terminal protrusion 41 (see FIG. 2) is protruded from the intermediate portion 36. By using the excess material to raise the groove instead of forming a wall that closes the groove, the sealing performance of the terminal groove 38 is improved.

[0061] At coining stop positions L11 and L12, the distance H1 between the bottom surface 85A of the mold recess 83A and the flat plate surface 31 (non-coining surface) may be shorter than the distance H2 between the top surface 84A of the mold protrusion 81A and the flat plate surface 31 (non-coining surface) (H1 < H2). By adopting this positional relationship, the escape material that flows in is densely packed inside the mold recess 83A. In other words, the shape of the mold recess 83A is accurately transferred to the escape material.

[0062] 4, second molds 60A, 60B coin both widthwise surfaces of intermediate portion 36 of metal terminal 30. Pressing surfaces 62A, 62B of second molds 60A, 60B are formed with concave-convex shapes (concave-convex grooves). The concave-convex grooves of pressing surfaces 62A, 62B have the same groove width and pitch as the concave-convex grooves of pressing surfaces 82A, 82B.

[0063] Fig. 6 illustrates a pressing surface 62A of the second mold 60A. The second mold 60B also has a pressing surface shape similar to that shown in Fig. 6. In the following description of the second mold 60A, the structure of the second mold 60B will be described by replacing the suffix "A" with "B."

[0064] A plurality of die protrusions 61A and die recesses 63A are formed on a pressing surface 62A of the second die 60A. In the second die 60A, the coining stop position of the bottom surface 65A of the die recess 63A is also located in front of the flat plate surface 35 (non-coining surface, see FIG. 2 ) of the intermediate portion 36 of the metal terminal 30. Furthermore, at the coining stop position, the distance between the bottom surface 85A of the die recess 83A and the flat plate surface 35 (non-coining surface) may be shorter than the distance between the top surface 84A of the die protrusion 81A and the flat plate surface 35 (non-coining surface).

[0065] Furthermore, the depth H7 of the mold recess 63A is shallower than the depth H8 (see FIG. 5) of the mold recess 83A of the first mold 80A. By performing coining using such a second mold 60A, the second groove 50, which is shallower than the first groove 40, is formed.

[0066] 4, the third molds 70A-70D are L-shaped in side view (L-axis direction). The third molds 70A-70D include first pressing surfaces 72A-72D and second pressing surfaces 74A-74D. The first pressing surfaces 72A-72D are disposed perpendicular to the second pressing surfaces 74A-74D.

[0067] 7 illustrates a first pressing surface 72A and a second pressing surface 74A of the third mold 70A. The third molds 70B-70D also have pressing surface shapes similar to those in FIG. 7. In the following description of the third mold 70A, the structures of the third molds 70B-70D will be explained by replacing the suffix "A" with "B," "C," or "D."

[0068] A concave-convex shape (concave-convex grooves) is formed on the first pressing surface 72A of the third mold 70A. That is, a plurality of mold convex portions 71A and mold concave portions 73A are formed on the first pressing surface 72A. The mold convex portions 71A and mold concave portions 73A have the same groove width and pitch as the mold convex portions 61A and mold concave portions 63A formed on the pressing surface 62A of the second mold 60A (see FIG. 6 ), for example.

[0069] Furthermore, a concave-convex shape (concave-convex grooves) is also formed on the second pressing surface 74A of the third mold 70A. That is, a plurality of mold convex portions 75A and mold concave portions 77A are formed on the second pressing surface 74A. The mold convex portions 75A and mold concave portions 77A have the same groove width and pitch as the mold convex portions 81A and mold concave portions 83A formed on the pressing surface 82A of the first mold 80A (see FIG. 5 ), for example.

[0070] As will be described later, the third dies 70A-70D are used in the bending process of the plate-shaped portion 45 (see FIG. 7). Since the bending process is an optional step and not an essential step, the third dies 70A-70D are optionally mounted on a press device.

[0071] 4, first molds 80A and 80B are pressed against the middle portion 36 of the metal terminal 30 (first groove forming). Next, second molds 60A and 60B press against the middle portion 36 (second groove forming). As an optional step, third molds 70A-70D press against the middle portion 36 (bending).

[0072] 5 illustrates the first groove processing. In the first groove processing, both thickness-wise surfaces of the intermediate portion 36 are coined into the first molds 80A and 80B. At this time, the coining stop position L12 of the bottom surfaces 85A and 85B of the mold recesses 83A and 83B is located in front of the flat surface 31 (non-coined surface) of the intermediate portion 36 of the metal terminal 30. In other words, the coining stop position L12 is set at a position where the bottom surfaces 85A and 85B of the mold recesses 83A and 83B are set back from the flat surface 31 (non-coined surface) of the intermediate portion 36 along the coining direction.

[0073] In the coining process, the metal (material) of the metal terminal 30 is pushed aside and moved by the mold protrusions 81A, 81B of the first molds 80A, 80B, resulting in "material escape." At the coining stop position L12, a gap is provided between the flat surface 31 (non-pressing surface) of the intermediate portion 36 and the bottom surface 85A of the mold recess 83A, and the escaped material is guided into the gap. This allows the terminal protrusion 41 (see FIG. 2) in the first groove 40 to be raised.

[0074] Furthermore, at coining stop positions L11 and L12, the distance H1 between the bottom surfaces 85A and 85B of the mold recesses 83A and 83B and the flat plate surface 31 (non-coining surface) may be shorter than the distance H2 between the top surfaces 84A and 84B of the mold protrusions 81A and 81B and the flat plate surface 31 (non-coining surface) (H1 < H2). This positional relationship allows the escape material to be densely packed into the mold recesses 83A and 83B. In other words, the shape of the mold recesses 83A and 83B is accurately transferred to the escape material.

[0075] After the first groove portion is formed, the second groove portion is formed. Referring to Fig. 6, second molds 60A and 60B coin both sides of the middle portion 36 in the width direction. During this coining, the mold protrusion 61A of the second mold 60A is aligned with the first groove portion 40. For example, the metal terminal 30 and the second molds 60A and 60B are aligned by an alignment mechanism such as a ball screw (not shown).

[0076] 5, when coining the second groove portion 50, the coining stop positions of the bottom surfaces 65A, 65B of the mold recesses 63A, 63B are positioned in front of the flat surface 35 (non-coined surface, see FIG. 2) of the middle portion 36 of the metal terminal 30. This allows the top surface 52 of the second groove portion 50 (see FIG. 8) to be raised.

[0077] Furthermore, at the coining stop position, the distance between the bottom surfaces 65A, 65B of the mold recesses 63A, 63B and the flat plate surface 35 (non-coining surface) may be shorter than the distance between the top surfaces 64A, 64B of the mold protrusions 61A, 61B and the flat plate surface 31 (non-coining surface). This allows the escape fill material to be densely packed into the mold recess 63A. In other words, the shape of the mold recess 63A is accurately transferred to the escape fill material.

[0078] Furthermore, the coining process using the second molds 60A and 60B causes relief material to enter the first groove portion 40. More specifically, the remaining relief material that did not enter the mold recesses 83A and 83B enters the first groove portion 40. This relief material becomes a plate-like portion 45 and stands on the longitudinal end portion 39 of the first groove portion 40.

[0079] However, because the second groove portion 50 is shallower than the first groove portion 40, the coining stroke is relatively short. In other words, the amount of material loss that occurs in the first place is smaller than the amount of material loss that occurs during the processing of the first groove portion 40. As a result, the height of the plate-like portion 45 is not so high that it blocks the entire cross section of the relatively deep first groove portion 40. In other words, even if the plate-like portion 45 occurs, as exemplified by gap H4 in Figure 6, the first groove portion 40 is sufficiently filled with resin, and the above-mentioned sealing effect is obtained.

[0080] After the second groove portion is formed, an optional bending process is performed. In the bending process, the plate-like portion 45 is bent by third molds 70A-70D. Referring to FIG. 4, the third molds 70A-70D press the intermediate portion 36 obliquely from the four corners of the cross section of the intermediate portion 36 toward the center of the cross section.

[0081] 7 and 8, by pressing in this manner, the plate-like portions 45 formed at the longitudinal ends 39 of the first groove portions 40 are bent so as to lie on the bottom surfaces 46 of the first groove portions 40. By bending the plate-like portions 45, the first groove portions 40 are opened to a sufficient depth around the entire periphery.

[0082] In the above-described embodiment, the first groove portion 40 is deeper than the second groove portion 50. Alternatively, the second groove portion 50 may be deeper than the first groove portion 40. For example, this alternative configuration is applicable when the height of the plate-shaped portion 45 is sufficiently smaller than the plate thickness of the intermediate portion 36.

[0083] In this alternative embodiment, the second groove portion is first machined, followed by the first groove portion, and then the plate-like portion 45 is formed on the bottom surface 56 of the second groove portion 50. The plate-like portion 45 is then laid down on the bottom surface 56 by a bending process.

[0084] Furthermore, if the height of the plate-like portion 45 is sufficiently smaller than the depths of the first groove portion 40 and the second groove portion 50, the first groove portion 40 and the second groove portion 50 may have the same depth. For example, if most of the relief material is used to raise the top surface 52 (see FIG. 8 ) in machining the second groove portion, the first groove portion 40 and the second groove portion 50 will have the same depth.

[0085] In the above embodiment, the terms "same" and "identical" encompass differences within a preset tolerance. That is, even if there is a difference between the two (for example, the groove depth of the first groove portion 40 and the second groove portion 50), the two are considered to be identical as long as the difference falls within the tolerance.

[0086] 10 Metal-resin composite molded body, 20 Resin part, 30 Metal terminal, 31, 35 Flat surface (non-coined surface) of metal terminal 32 First end, 34 Second end, 36 Middle portion, 38 Terminal groove, 39 Longitudinal end of first groove portion, 40 First groove portion, 41 Terminal convex portion, 43 Terminal concave portion, 44 Side surface of terminal groove, 45 Plate-shaped portion, 46 Bottom surface of first groove portion, 50 Second groove portion, 52A, 52B Pressing surface of first mold, 60A, 60B Second mold, 61, 71, 81 Mold convex portion, 62A, 62B Pressing surface of second mold, 63, 73, 83 Mold concave portion, 70A-70D Third mold, 72A-72D First pressing surface of third mold, 74A-74D Second pressing surface of third mold, 80A, 80B First mold.

Claims

1. A metal resin composite molding comprising: a flat metal terminal; and a resin part that exposes both ends of the metal terminal and embeds a middle portion of the metal terminal, wherein a groove is formed in the middle portion of the metal terminal; the groove is formed around the entire circumference of the metal terminal by a first groove portion formed on both thickness-wise surfaces of the metal terminal and a second groove portion formed on both width-wise surfaces of the metal terminal and connected to the first groove portion; the first groove portion is deeper than the second groove portion; and a plate-shaped portion is positioned at the longitudinal end of the first groove portion with its bottom surface laid flat.

2. A metal resin composite molding as claimed in claim 1, wherein the groove is formed by forming recesses and protrusions around the entire circumference by coining, a plurality of the grooves are arranged along the longitudinal direction of the intermediate portion, the recesses are recessed from the non-coined surface of the intermediate portion, the protrusions protrude from the non-coined surface of the intermediate portion, and the side surfaces of the groove formed by the recesses and protrusions extend perpendicular to the non-coined surface.

3. A metal resin composite molding according to claim 1 or 2, wherein at least some of the plurality of grooves are arranged at different pitches.

4. A method for manufacturing a metal resin composite molded product comprising: a flat metal terminal; and a resin part that exposes both ends of the metal terminal and embeds a middle portion of the metal terminal, wherein a groove is formed around the entire circumference of the middle portion by coining both thickness-wise and width-wise surfaces of the middle portion with a mold having an uneven shape formed on its pressing surface, the mold comprising a first mold having an uneven shape formed on its pressing surface, and a second mold and a third mold having an uneven shape formed on their pressing surfaces with the same groove width and pitch as the first mold, the coining process comprising: first groove portion processing, in which a first groove portion is formed in the middle portion by coining both thickness-wise surfaces of the middle portion with the first mold; and second groove portion processing, in which a second groove portion connected to the first groove portion is formed in the middle portion by coining both width-wise surfaces of the middle portion with the second mold after the first groove portion processing. a bending process in which, after processing the second groove portion, the plate-shaped portion formed at the longitudinal end of the first groove portion is bent in the third mold so as to lie on a bottom surface of the first groove portion.

5. A method for manufacturing a metal resin composite molded body according to claim 4, wherein the first mold has deeper concave and convex grooves than the second mold.

6. A method for manufacturing a metal resin composite molded product comprising: a flat metal terminal; and a resin part that exposes both ends of the metal terminal and embeds a middle portion of the metal terminal, wherein a groove is formed around the entire circumference of the middle portion by coining both thickness-wise and width-wise surfaces of the middle portion with a mold having an uneven shape formed on its pressing surface, the mold comprising a first mold having an uneven shape formed on its pressing surface, and a second mold and a third mold having an uneven shape formed on their pressing surfaces with the same groove width and pitch as the first mold, the coining process comprising: second groove portion processing, in which a second groove portion is formed in the middle portion by coining both width-wise surfaces of the middle portion with the second mold; and first groove portion processing, in which a first groove portion connected to the second groove portion is formed in the middle portion by coining both thickness-wise surfaces of the middle portion with the first mold after the second groove portion processing. a bending process in which, after processing the first groove portion, the plate-shaped portion formed at the longitudinal end of the second groove portion is bent in the third mold so as to lie on a bottom surface of the second groove portion.

7. A metal resin composite molding comprising: a flat metal terminal; and a resin part that exposes both ends of the metal terminal and embeds a middle portion of the metal terminal, wherein a groove is formed in the middle portion of the metal terminal; the groove is formed around the entire periphery of the metal terminal by a first groove portion formed on both thickness-wise surfaces of the metal terminal and a second groove portion formed on both width-wise surfaces of the metal terminal and connected to the first groove portion; and a plate-shaped portion is placed on the bottom surface of the longitudinal end of the first groove portion or the second groove portion.

8. A metal resin composite molding comprising: a flat metal terminal; and a resin part that exposes both ends of the metal terminal and embeds a middle portion of the metal terminal, wherein a groove is formed in the middle portion of the metal terminal; the groove is formed around the entire circumference of the metal terminal by a first groove portion formed on both thickness-wise surfaces of the metal terminal and a second groove portion formed on both width-wise surfaces of the metal terminal and connected to the first groove portion; the second groove portion is deeper than the first groove portion; and a plate-shaped portion is placed at the bottom of the longitudinal end of the second groove portion with the bottom surface laid flat.

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