Resin molded product and first component

Abstract

This invention discloses a resin molded product that can suppress variations in the degree of melting of the melted portion of the melt rib provided in the first component, thereby promoting uniformity of the melted state of the melted portion and promoting uniformity of the strength at the welding site of the melted portion to the second component. [Solution] The resin molded product 10 comprises a first part 22 made of synthetic resin and a second part 24 made of synthetic resin. The first part 22 has an embedded portion 26 which is embedded in and integrated with the second part 24, a groove 28 which opens on the surfaces 62,84 of the embedded portion 26 facing the second part 24, and a melt rib 32 which protrudes into the groove 28 and has a molten portion 30. The molten portion 30 is welded to the second part 24 which fills the groove 28.

Description

Technical Field

[0001] The present disclosure relates to a resin molded product and a first component.

Background Art

[0002] In Patent Document 1, in a connector component which is a kind of resin molded product, a melt rib is provided that protrudes outward from the main body of an inner component which is a first component and around which an outer component which is a second component is integrally molded. A configuration is disclosed in which a part of the melted part provided on the melt rib melts during the molding of the outer part and adheres closely to the resin body of the outer part.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the structure of Patent Document 1, since the melt rib is provided to protrude outward from the main body of the inner component, when molding the outer component, variation is likely to occur in the time during which the melt rib is exposed to the flow of the molten resin based on the difference in the separation distance from the gate position of the melt rib. As a result, the melting state of the melted part of the melt rib is likely to become non-uniform, and there is a possibility that a difference will occur in the fixing strength between the melted part and the resin body of the outer part due to the variation in the melting state.

[0005] Therefore, a resin molded product and a first component are disclosed that can suppress variation in the melting state of the melted part of the melt rib provided on the first component, promote the uniformity of the melting state of the melted part, and promote the uniformity of the strength at the welding site of the melted part to the second component.

Means for Solving the Problems

[0006] The resin molded product of the present disclosure comprises a first component made of synthetic resin and a second component made of synthetic resin, wherein the first component has an embedded portion that is embedded in and integrated with the second component, a groove opening on the surface of the embedded portion facing the second component, and a melt rib protruding from the groove and having a molten portion, the molten portion being welded to the second component that fills the groove.

[0007] The first component of this disclosure is a synthetic resin component which is inserted into a second component made of synthetic resin and integrated with the second component, and comprises an embedded portion which is embedded in the second component, a groove which opens on the surface of the embedded portion facing the second component, and a melt rib which protrudes from the groove and whose tip is a melting portion, wherein the melting portion is melted when the second component is molded. [Effects of the Invention]

[0008] According to the resin molded product of this disclosure, variations in the degree of melting of the melted portion of the melt rib provided in the first component can be suppressed, thereby promoting uniformity of the melted state of the melted portion and promoting uniformity of the strength at the welding site of the melted portion to the second component.

[0009] According to the first component of this disclosure, in a resin molded product, variations in the degree of melting of the melted portion of the melt rib provided in the first component can be suppressed, thereby promoting uniformity of the melted state of the melted portion and promoting uniformity of the strength at the welding site of the melted portion to the second component. [Brief explanation of the drawing]

[0010] [Figure 1] Figure 1 is a plan view showing an electrical junction box, which is a resin molded product according to Embodiment 1. [Figure 2] Figure 2 is a longitudinal cross-sectional view showing an enlarged view of the main part of the II-II section in Figure 1. [Figure 3] Figure 3 is a longitudinal cross-sectional view showing an enlarged view of the main part of the III-III section in Figure 1. [Modes for carrying out the invention]

[0011] <Description of Embodiments in this Disclosure> First, embodiments of this disclosure will be listed and described. The resin molded articles disclosed herein are (1) The device comprises a first part made of synthetic resin and a second part made of synthetic resin, wherein the first part has an embedded portion that is embedded in and integrated with the second part, a groove that opens on the surface of the embedded portion facing the second part, and a melt rib that protrudes from the groove and has a molten portion, the molten portion being welded to the second part that fills the groove.

[0012] In the resin molded product of this embodiment, the first part is integrated with the second part, having an embedded portion that is embedded in the second part. Furthermore, the embedded portion is provided with a groove that opens to the surface facing the second part, and the molten portion of the melt rib protruding into the groove is welded to the second part that fills the groove. As a result, a welded portion is formed between the embedded portion of the first part and the opposing surface of the second part, where the molten portion has melted and solidified with the second part, thereby advantageously achieving the required bonding strength between the first and second parts and ensuring a seal between their opposing surfaces.

[0013] In particular, since the melt rib is provided protruding from a groove that opens onto the surface of the embedded part facing the second part, it is less affected by the flow velocity of the molten resin during injection molding of the second part. Therefore, compared to the conventional structure in which the melt rib of the embedded part directly protrudes from the surface facing the second part, it is possible to advantageously reduce the problem of variations in the degree of melting of the molten part depending on the distance from the molding gate position of the second part. As a result, the uniformity of the melt state of the molten part can be promoted, and the strength at the welding site of the molten part to the second part can be made uniform. In addition, the degree of freedom in setting the gate position during molding of the second part is improved.

[0014] In addition, since the resin constituting the second component is filled into the groove provided in the embedded portion of the first component, the groove can absorb the strain caused by the mutual displacement of the first and second components due to temperature changes during use of the resin molded product. This reduces stress concentration at the welding site to the second component in the molten portion, and stably maintains the adhesion and sealing properties of the first and second components.

[0015] (2) In (1) above, it is preferable that the embedded portion of the first component is arranged to surround the periphery of the waterproof area of ​​the second component, the groove is formed in an annular shape surrounding the periphery of the waterproof area of ​​the second component, and the molten portion is welded to the second component filling the groove over the entire circumference of the groove. When the embedded portion of the first component is arranged to surround the waterproof area of ​​the second component, the molten portion of the melt rib provided in the annular groove that opens to the embedded portion of the first component and surrounds the periphery of the waterproof area is welded to the second component filling the groove over the entire circumference of the groove. As a result, the watertightness of the waterproof area of ​​the second component can be ensured by welding the molten portion to the second component without having to arrange a sealing member around the waterproof area of ​​the second component. This makes it possible to simplify and miniaturize the resin molded product while ensuring the watertightness of the waterproof area.

[0016] (3) In (1) or (2) above, it is preferable that the melt rib protrudes from the bottom surface of the groove toward the opening side. Since the melt rib protrudes from the bottom surface of the groove toward the opening side, it is less affected by the flow velocity of the molten resin during injection molding of the second part, and the uniformity of the bonding strength of the molten portion of the melt rib to the second part can be further advantageously achieved.

[0017] (4) In (3) above, it is preferable that the protruding dimension of the melt rib is 2 / 3 or less of the depth dimension of the groove. Since the protruding dimension of the melt rib toward the opening side from the bottom surface of the groove is kept to 2 / 3 or less of the depth dimension of the groove, the influence of the flow velocity of the molten resin during injection molding of the second part can be further advantageously reduced, and the uniformity of the bonding strength of the welded portion of the melt rib to the second part can be further advantageously achieved.

[0018] (5) In the above (2), the second component includes a case that houses a circuit board inside, the first component includes a connector mounting portion provided at an opening of the case as the waterproof area, the connector mounting portion has a hood portion protruding on the case and an embedding portion that spreads in a flange shape on the proximal end side of the hood portion, and it is preferable that the embedding portion surrounds the periphery of the opening. When the second component of the resin molded product is a case that houses a circuit board inside and the first component is a connector mounting portion provided at the opening of the case, the resin molded product having the waterproof function of this aspect can be applied to an electrical connection box. At this time, by using the flange-shaped portion on the proximal end side that bears the load applied to the connector mounting portion as the embedding portion, an annular concave groove surrounding the periphery of the opening can be advantageously provided. And since the welding site of the molten portion of the melt rib to the second component is provided over the entire circumference of the concave groove surrounding the periphery of the opening, the waterproof performance due to the welding site of the molten portion to the second component between the opposing surfaces of the case and the embedding portion can be surely and stably realized over the entire circumference of the opening.

[0019] The first component of the present disclosure is (6) A first component made of synthetic resin that is inserted into a second component made of synthetic resin and integrated with the second component, having an embedding portion embedded in the second component, a concave groove opening to the opposing surface of the embedding portion to the second component, and a melt rib protruding in the concave groove and having a molten portion on the tip side, and the molten portion is configured to melt during the molding of the second component.

[0020] According to the first component of this aspect, it has an embedding portion embedded in the second component and is integrated with the second component. Moreover, the embedding portion is provided with a concave groove opening to the opposing surface to the second component, and the concave groove is provided with a molten portion that melts during the molding of the second component on the melt rib protruding in the concave groove. Therefore, by inserting the first component and injection molding the second component so that the embedding portion is embedded, the resin molded product according to any one of the aspects (1) to (5) above can be provided, and the same operational effects can be enjoyed.

[0021] <Details of Embodiments of the Present Disclosure> Specific examples of the resin molded products of the present disclosure will be described below with reference to the drawings. It should be noted that the present disclosure is not limited to these examples, but is defined by the claims, and is intended to include all modifications within the meaning and scope equivalent to the claims.

[0022] <Embodiment 1> Hereinafter, an electric connection box 10, which is a resin molded product of Embodiment 1 of the present disclosure, will be described with reference to FIGS. 1 to 3. This electric connection box 10 includes a case 14 in which a circuit board 12 is housed. Specifically, the case 14 is composed of an upper case 16 and a lower case 18, and the upper opening 20 in the lower case 18 is covered by the upper case 16 to form the case 14. Although the electric connection box 10 can be arranged in any orientation, hereinafter, the upper side refers to the upper side in FIG. 2, the lower side refers to the lower side in FIG. 2, the front side refers to the left side in FIG. 1, the rear side refers to the right side in FIG. 1, the left side refers to the upper side in FIG. 1, and the right side refers to the lower side in FIG. 1. Also, for a plurality of identical members, only some members may be labeled with reference numerals, and the reference numerals may be omitted for other members.

[0023] <Resin Molded Product (Electric Connection Box 10)> The electric connection box 10 includes a first component 22 made of synthetic resin and a second component 24 made of synthetic resin. The first component 22 has an embedded portion 26 that is embedded in the second component 24 and integrated therewith, a concave groove 28 that opens to the opposing surface (outer surfaces 62 and 84 described later) of the embedded portion 26 to the second component 24, and a melt rib 32 that protrudes into the concave groove 28 and has a melting portion 30. The melting portion 30 of this melt rib 32 is welded to the second component 24 filled in the concave groove 28, whereby the first component 22 and the second component 24 are welded to each other. It should be noted that the embedded portion 26 of the first component 22 does not need to be entirely embedded in the second component 24, and a part of the embedded portion 26 may be exposed to the outside from the second component 24.

[0024] In particular, in Embodiment 1, the electrical connection box 10 (especially the upper case 16) comprises a plurality of first components 22, each first component 22 comprising a plurality of connector mounting portions 38 (described later) and a terminal block 40. The second component 24 includes a case 14 that houses the circuit board 12, and specifically comprises an upper bottom wall portion 42 and a lower case 18 in the upper case 16 (described later). Therefore, in Embodiment 1, the second component 24 comprises a plurality of members.

[0025] The circuit board 12 housed in the electrical connection box 10 (case 14) is not limited to any particular type, but a known circuit board such as a rigid printed circuit board or a flexible printed circuit board (FPC) may be used, and an electrical circuit (not shown) is printed on at least one surface of the circuit board 12 in the thickness direction. Furthermore, through-holes 34 that penetrate the circuit board 12 in the thickness direction are formed at predetermined locations on the circuit board 12. The method of fixing the circuit board 12 to the case 14 is not limited to any particular type.

[0026] <Upper Case 16> The upper case 16 comprises a plurality of connector mounting sections 38 and a terminal block 40, which are first components 22. The upper case 16 also includes a substantially flat upper bottom wall section 42, and as described above, the second component 24 is formed including the upper bottom wall section 42. Each first component 22 (each connector mounting section 38 and terminal block 40) is fixed to the upper bottom wall section 42. In Embodiment 1, the upper bottom wall section 42 comprises a plurality of waterproof areas 44 on which each first component 22 is provided. Each waterproof area 44 is a part of the upper bottom wall section 42 where watertight sealing is required, and the embedded portion 26 of the first component 22 is arranged to surround the waterproof area 44, and the embedded portion 26 and the second component 24 are fixed together to prevent water from entering the waterproof area 44. Specifically, the waterproof area 44 is composed of an opening 46 to which each connector mounting portion 38 is fixed, and a through portion 48 to which the terminal block 40 is fixed.

[0027] <Lower Case 18> The lower case 18 is generally box-shaped, opening upward (having an upper opening 20), and comprises a generally flat bottom wall portion 52 that extends horizontally (in a direction perpendicular to the vertical direction), and a lower peripheral wall portion 54 that protrudes upward from the outer peripheral edge of the bottom wall portion 52. Therefore, the upper opening 20 is formed by the upper end of the lower peripheral wall portion 54. The method of fixing the upper case 16 and the lower case 18 is not limited.

[0028] The lower case 18 can be formed from a rigid material such as metal or synthetic resin. When the lower case 18 is made of synthetic resin, materials such as polyphenylene sulfide (PPS) or polybutylene terephthalate (PBT) are preferably used. Furthermore, when the lower case 18 is made of synthetic resin, it may be reinforced with glass fibers or the like.

[0029] <Part 1 22 (Connector mounting section 38)> In Embodiment 1, as described above, some of the first components 22 are made up of connector mounting portions 38. Each connector mounting portion 38, as shown in Figure 2, includes a hood portion 60 that protrudes upward from the case 14 (particularly the upper bottom wall portion 42 of the upper case 16) and an embedded portion 26 that spreads out in a flange-like manner at the base end (lower end) of the hood portion 60. In Embodiment 1, the hood portion 60 is substantially cylindrical and continuous around the entire circumference, and the embedded portion 26 at the base end (lower end) of the hood portion 60 is formed as a substantially annular portion that protrudes outward around the entire circumference. In particular, in Embodiment 1, each hood portion 60 is formed in a substantially rectangular annular shape in plan view, and each embedded portion 26 is also formed in a substantially rectangular annular shape in plan view. A groove 28 that opens downward is formed on the lower surface of the embedded portion 26, which is thus substantially rectangular annular. As will be described later, in the connector mounting portion 38, the outer surface 62 of the embedded portion 26, including the inner circumferential surface, lower surface, and outer circumferential surface of the embedded portion 26, forms the opposing surface between the embedded portion 26 and the second component 24. Therefore, the groove 28 opens to the surface of the embedded portion 26 that faces the second component 24.

[0030] In Embodiment 1, the connector mounting portion 38 has a terminal retaining wall 66 that divides the hood portion 60 into an inward (downward) side and an outward (upward) side of the case 14. The connector mounting portion 38 also includes connection terminals 68 that penetrate the terminal retaining wall 66 and protrude to the inward (downward) side and outward (upward) side of the case 14. In Embodiment 1, a plurality of connection terminals 68 are provided, and each connection terminal 68 is fixedly held against the terminal retaining wall 66. Each connection terminal 68 is arranged in alignment in the front-to-back and left-to-right directions on the inner circumference of the hood portion 60.

[0031] Specifically, in the vertically intermediate portion of the hood portion 60, a terminal retaining wall 66 is provided that extends horizontally on the inner circumference side of the hood portion 60. The intermediate portion of each connection terminal 68 extending in the vertical direction is embedded and fixed to the terminal retaining wall 66, with one end (lower end) of each connection terminal 68 protruding downward from the terminal retaining wall 66 and the other end (upper end) of each connection terminal 68 protruding upward from the terminal retaining wall 66. In other words, when the upper case 16, which includes each connector mounting portion 38, is fixed to the lower case 18 to form the case 14 (electrical connection box 10), one end (lower end) of each connection terminal 68 protrudes inward from the case 14, and the other end (upper end) of each connection terminal 68 protrudes outward from the case 14.

[0032] In Embodiment 1, the connector mounting portion 38 is formed as an integrally molded product equipped with each connection terminal 68. Specifically, when molding the connector mounting portion 38, injection molding is performed with each connection terminal 68 set as an insert within the molding cavity of the connector mounting portion 38, thereby forming the connector mounting portion 38 as an integrally molded product equipped with each connection terminal 68. As a result, each connection terminal 68 is fixedly held against the terminal holding wall 66. The resin material constituting the connector mounting portion 38 (hood portion 60 and embedded portion 26) is not limited as long as it is rigid, but materials such as PPS and PBT are preferably used, similar to the lower case 18, and may be reinforced with, for example, glass fiber.

[0033] Furthermore, the other end (upper end) of each connection terminal 68 is located on the inner circumference side of the hood portion 60 and protrudes upward. As a result, each connector mounting portion 38 constitutes a male connector, and when a female connector (not shown) is attached to each connector mounting portion 38, each connection terminal 68 and the connection terminal of the female connector are electrically connected.

[0034] <Concave groove 28> Each groove 28 is an annular groove that extends continuously around the entire circumference in the circumferential direction. In Embodiment 1, each groove 28 is formed in the radially intermediate portion of the lower surface of each embedded portion 26. As mentioned above, each embedded portion 26 is provided surrounding the periphery of the waterproof area 44, and therefore each groove 28 is provided surrounding the periphery of each waterproof area 44. In particular, in Embodiment 1, each groove 28 opens downward and has a rectangular cross-sectional shape with an upper bottom surface 72 which is the bottom surface and an inner surface consisting of both sides.

[0035] <Meltriv 32> As described above, a melt rib 32 having a molten portion 30 protrudes from the groove 28. The melt rib 32 is integrally formed with the upper bottom wall portion 42 and has a shape that gradually or stepwise narrows towards the protruding tip. When the first part 22 and the second part 24 are fixed together as described later, when the second part 24 is molded with the first part 22 as an insert, the molten resin material of the second part 24 flows into the groove 28, causing the protruding tip portion of the melt rib 32 to melt and become integrated with the second part 24. Therefore, the protruding tip portion of the melt rib 32 is the molten portion 30. The molten portion 30 is welded to the second part 24 that fills the groove 28 around its entire circumference. In Figures 2 and 3, the melt rib 32 before the melting of the molten portion 30 is shown by a dashed line, and the melt rib 32 after the melting of the molten portion 30 is shown by a solid line. As shown in Figures 2 and 3, in Embodiment 1, the melt rib 32 of the molten portion 30 before melting has a substantially triangular cross-section and protrudes downward from the upper bottom surface 72 of the groove 28.

[0036] Furthermore, in Embodiment 1, the melt rib 32 is continuously provided within the groove 28 over the entire circumference in the circumferential direction, and is formed in an annular shape in plan view (projection in the axial direction). In particular, in Embodiment 1, two of these annular melt ribs 32 are provided within the groove 28, and the two melt ribs 32, 32 are provided substantially adjacent to each other on the inner and outer circumferential sides.

[0037] Furthermore, the downward protrusion dimension T (see Figure 2) of each melt rib 32 before melting in the molten section 30 is preferably such that the protruding tip does not protrude below the lower opening of the groove 28, for example, it is preferably 2 / 3 or less of the depth dimension D (see Figure 2) of the groove 28. In Embodiment 1, the protrusion dimension T of each melt rib 32 is set to about 1 / 2 of the depth dimension D of the groove 28.

[0038] <Part 1 22 (Terminal Block 40)> In Embodiment 1, as described above, one of the first components 22 is comprised of a terminal block 40. This terminal block 40 includes a connecting terminal 76 having one end connected to a circuit board 12 and the other end having a terminal fastening portion 74, and a terminal base 78 that holds the connecting terminal 76 with the terminal fastening portion 74 exposed above the through portion 48, which is a waterproof area 44.

[0039] Specifically, in Embodiment 1, the connection terminal 76 is bent in a roughly L-shape, with one end extending downward and connected to the circuit board 12. The other end of the connection terminal 76 spreads horizontally, forming a terminal fastening portion 74 that is roughly rectangular in plan view. A bolt insertion hole 80 is formed in the central part of the terminal fastening portion 74, penetrating in the thickness direction (vertical direction), and the shaft of a stud bolt 82 positioned below the terminal fastening portion 74 protrudes upward through the bolt insertion hole 80. Thus, when a mating terminal (not shown) is connected to the connection terminal 76, the shaft of the stud bolt 82 is inserted through the bolt insertion hole provided in the mating terminal, and a nut is fastened to the stud bolt 82, thereby overlapping the mating terminal and the terminal fastening portion 74 and electrically connecting them.

[0040] The terminal fastening portion 74 and the stud bolt 82 are supported on the terminal base 78, and as described above, the terminal fastening portion 74 is exposed upward, and the shaft portion of the stud bolt 82 protrudes upward. The terminal base 78 is substantially rectangular in plan view and has a predetermined thickness. The embedded portion 26 is formed by the peripheral edge of the base end (lower end) of this terminal base 78. Specifically, the base end (lower end) of the terminal base 78 protrudes outward relative to the upper portion, and the embedded portion 26 is formed by this outwardly protruding portion. This embedded portion 26 is formed in a continuous ring shape over the entire circumference in the circumferential direction.

[0041] Furthermore, a groove 28 opening downwards is formed on the lower surface of the terminal base 78. This groove 28 has the same shape as the groove 28 in the connector mounting portion 38 and is an annular groove that extends continuously around the entire circumference. Within this groove 28, as in the connector mounting portion 38, two melt ribs 32, 32 protruding downwards are provided. This groove 28 may be provided in the embedded portion 26, or it may be provided on the inner circumference side of the embedded portion 26. As will be described later, in the terminal block 40 as well, the outer surface 84 of the embedded portion 26, including the inner surface, lower surface, and outer surface of the embedded portion 26, constitutes the opposing surface between the embedded portion 26 and the second component 24, so the groove 28 opens to the surface of the embedded portion 26 that is facing the second component 24.

[0042] In Embodiment 1, the terminal block 40 is formed as an integrally molded product equipped with connection terminals 76 and stud bolts 82. Specifically, when molding the terminal block 40, the connection terminals 76 and stud bolts 82 are inserted into the molding cavity of the terminal block 40 during injection molding, thereby forming the terminal block 40 as an integrally molded product equipped with connection terminals 76 and stud bolts 82. As a result, the connection terminals 76 and stud bolts 82 are fixedly held in place by the terminal base 78. The resin material constituting the terminal base 78 is not limited as long as it is rigid, but materials such as PPS or PBT are preferably used, similar to the connector mounting portion 38, and it may be reinforced with, for example, glass fiber.

[0043] <Part 2, Item 24> As described above, the second component 24 is composed of an upper bottom wall portion 42 and a lower case 18 in the upper case 16. In the upper bottom wall portion 42, an opening 46 is formed as a waterproof area 44 that penetrates the upper bottom wall portion 42 vertically at the location where each connector mounting portion 38, which is a first component 22, is fixed. Also, in the upper bottom wall portion 42, a penetration portion 48 is formed as a waterproof area 44 that penetrates the upper bottom wall portion 42 vertically at the location where the terminal block 40, which is a first component 22, is fixed. Since the embedded portion 26 of each first component 22 is provided to surround the periphery of each waterproof area 44, the embedded portion 26 provided in each connector mounting portion 38 surrounds the periphery of the opening 46, and the embedded portion 26 provided in the terminal block 40 surrounds the periphery of the penetration portion 48.

[0044] <Waterproof area 44 (opening 46)> The opening 46, which serves as the waterproof area 44, has a shape that substantially corresponds to the connector mounting portion 38 in a plan view and is substantially rectangular. The opening 46 is formed by penetrating the upper bottom wall portion 42 in the vertical direction, and a receiving recess 88 is formed on the periphery of the opening 46 to accommodate the embedded portion 26 provided at the lower end of the connector mounting portion 38. As shown in Figure 2, the receiving recess 88 has a rectangular cross-sectional shape that substantially corresponds to the embedded portion 26 and is an annular recess that is continuous around the entire circumference in the circumferential direction around the opening 46. In short, when the first component (connector mounting portion 38) and the second component (upper bottom wall portion 42) are fixed together, each embedded portion 26 is housed within each receiving recess 88, and the outer surface 62 of each embedded portion 26 (including the inner circumferential surface, bottom surface, and outer circumferential surface of the embedded portion 26) and the inner surface 90 of each receiving recess 88 (including the inner circumferential side surface, bottom surface, and outer circumferential side surface of the receiving recess 88) are the opposing surfaces of the embedded portion 26 and the second component 24. Note that when the first component 22 and the second component 24 are fixed together and each embedded portion 26 is housed in the receiving recess 88, the upper surface of each embedded portion 26 is exposed to the outside.

[0045] <Waterproof area 44 (penetration 48)> The through-hole 48, which serves as a waterproof area 44, is the portion in the upper bottom wall 42 through which the longitudinal middle portion of the connection terminal 76 provided on the terminal block 40 is inserted, and is rectangular in shape in plan view, corresponding to the connection terminal 76. Around the through-hole 48, a housing recess 92 is formed to accommodate the terminal base 78 and the embedded portion 26. In short, when the first component (terminal block 40) and the second component (upper bottom wall 42) are fixed together, the terminal base 78 and the embedded portion 26 are housed in the housing recess 92, and the outer surfaces 84 of the terminal base 78 and the embedded portion 26 (including the lower surfaces of the terminal base 78 and the embedded portion 26 and the outer peripheral surface of the embedded portion 26) and the inner surface 94 of the housing recess 92 (including the inner peripheral side surface, bottom surface and outer peripheral side surface of the housing recess 92) are the opposing surfaces of the embedded portion 26 and the second component 24. When the first part 22 and the second part 24 are fixed together and the terminal base 78 and the embedded part 26 are housed in the recess 92, the upper portion of the terminal base 78 and the upper surface of the embedded part 26 are exposed to the outside.

[0046] <Manufacturing method for resin molded product (electrical connection box 10)> The following describes a specific example of a method for manufacturing the electrical junction box 10. However, the method for manufacturing the electrical junction box 10 is not limited to the description below.

[0047] First, in the first component molding process, the first component 22, namely the connector mounting portion 38 and the terminal block 40, is formed by injection molding. In Embodiment 1, since the connector mounting portion 38 is formed integrally with each connection terminal 68, a connector mounting portion 38 equipped with each connection terminal 68 is obtained. Also, since the terminal block 40 is formed integrally with the connection terminals 76, a terminal block 40 equipped with the connection terminals 76 is obtained by the first component molding process.

[0048] Next, in the second part molding process, multiple first parts 22 (each connector mounting part 38 and terminal block 40) manufactured in the first part molding process are set as inserts in the molding cavity of the upper bottom wall 42 which constitutes a part of the second part 24, and the upper bottom wall 42 is formed by injection molding. As a result, a receiving recess 88 is formed to cover the area around the embedded part 26 of each connector mounting part 38, and a receiving recess 92 is formed to cover the area around the terminal base 78 and embedded part 26 of the terminal block 40, thereby forming a second part 24 (upper bottom wall 42) that integrally incorporates each first part 22. When molding this upper bottom wall 42, the molten upper bottom wall 42 is filled into the molding cavity in which each first part 22 is inserted, so the molten upper bottom wall 42 flows into the groove 28 of each first part 22. Then, the heat from the molten upper bottom wall 42 melts the molten portion 30, which is the protruding tip of each melt rib 32, causing these melt ribs 32 (each embedded portion 26) to fuse and adhere to the upper bottom wall 42. As a result, the upper case 16 is completed.

[0049] Then, for example, the circuit board 12 is brought close to the upper case 16 manufactured as described above from below and fixed with screws. As a result, one end (lower end) of each connection terminal 68 and connection terminal 76 that protrudes downward from the upper case 16 is inserted into each through-hole 34 in the circuit board 12. Each connection terminal 68 and connection terminal 76 inserted into each through-hole 34 may be electrically connected to the circuit board 12 by solder or the like (not shown). Furthermore, the upper case 16 with the circuit board 12 assembled is brought close to the separately formed lower case 18 from above, and with the upper case 16 covering the upper opening 20 of the lower case 18, the upper case 16 and lower case 18 are fixed together, for example, with screws. As a result, the entire second component 24 is formed by the upper bottom wall 42 and the lower case 18, and a case 14 containing the circuit board 12 is formed inside, completing the electrical connection box 10.

[0050] According to the resin molded product (electrical connection box 10) of Embodiment 1, which has the structure described above, a groove 28 is provided between a first component 22 made of synthetic resin and a second component 24 made of synthetic resin, and the first component 22 and the second component 24 are more firmly welded together by utilizing the melt ribs 32 that protrude into the groove 28. More specifically, the first component 22 has an embedded portion 26 that is embedded in the second component 24, and each groove 28 and each melt rib 32 is provided between the opposing surfaces (outer surfaces 62, 84 and inner surfaces 90, 94) of the embedded portion 26 and the second component 24, and the first component 22 and the second component 24 are welded together by melting the molten portion 30 in each melt rib 32 with the heat of the second component 24 that is filled into each groove 28. As a result, the first component 22 and the second component 24 are more firmly fixed together, and the intrusion of water through them can be more reliably prevented.

[0051] In particular, when molding the second part 24, the molten second part 24 (upper bottom wall portion 42) flows into each groove 28 in each first part 22. Within each groove 28, the flow velocity of the molten upper bottom wall portion 42 is less likely to change, and the molten portion 30 in each melt rib 32 within each groove 28 melts almost uniformly. As a result, gaps are less likely to form between the first part 22 and the second part 24 after the electrical connection box 10 is manufactured, and the above-mentioned water intrusion prevention effect is achieved even more reliably. As a result, the degree of freedom in setting the gate position when molding the second part 24 can also be improved. Furthermore, since each melt rib 32 is provided within each groove 28, even when the resin molded product (electrical connection box 10) expands or contracts due to temperature changes in the external environment, stress does not concentrate at the protruding tip of each melt rib 32. This strain can be received by each groove 28, making it even less likely for gaps to form between the first part 22 and the second part 24, especially at the formation positions of each melt rib 32.

[0052] The first component 22 (each connector mounting portion 38 and terminal block 40) is arranged to surround the waterproof area 44 (each opening 46 and through portion 48) of the second component 24 (upper bottom wall portion 42), with each groove 28 formed in an annular shape, and each melt rib 32 within each groove 28 also formed in an annular shape. Therefore, when the second component 24 is molded, the molten portion 30 of each melt rib 32 melts and integrates with the second component 24 around the waterproof area 44, thereby effectively preventing water from entering the area around the waterproof area 44 where a waterproof structure is required.

[0053] Each melt rib 32 is provided so as to protrude downward from the bottom surface (upper bottom surface 72) of each groove 28 toward the opening side. This makes it possible to make the timing of contact between the molten upper bottom wall 42 and each melt rib 32 when the molten second part 24 (upper bottom wall 42) flows into each groove 28 approximately equal. As a result, the molten portion 30 in each melt rib 32 can be melted approximately uniformly, and problems such as the occurrence of gaps between the first part 22 and the second part 24 due to uneven melting of the molten portion 30 can be suppressed even more reliably.

[0054] In particular, since the protruding dimension T of each melt rib 32 is 2 / 3 or less of the depth dimension D of each groove 28, compared to, for example, the case where the protruding tip of each melt rib 32 is located near the opening of each groove 28, the timing difference in contact between the molten upper bottom wall 42 and each melt rib 32 when the molten upper bottom wall 42 is filled into the molding cavity of the upper bottom wall 42 can be made smaller. As a result, the influence of the molten upper bottom wall 42 can be reduced, and the molten portion 30 can be melted substantially uniformly, thereby more firmly fixing the first part 22 and the second part 24.

[0055] In Embodiment 1, a plurality of first parts 22 are provided, some of which are connector mounting parts 38, and the second part 24 is the upper bottom wall 42 of the upper case 16 and the lower case 18 that constitute the case 14. Thus, an electrical junction box 10 equipped with a plurality of connector mounting parts 38 is constructed as a resin molded product comprising the first part 22 and the second part 24. That is, when providing the connector mounting parts 38 in the electrical junction box 10, an opening 46 that penetrates in the thickness direction is formed in the upper bottom wall 42, and by fixing the connector mounting parts 38 (embedded parts 26) to this opening 46 which serves as a waterproof area 44, the intrusion of water through the opening 46 can be effectively prevented.

[0056] <Variation> While Embodiment 1 has been described in detail above as a specific example of the present disclosure, the present disclosure is not limited by this specific description. Modifications, improvements, etc., to the extent that they can achieve the objectives of the present disclosure are included in the present disclosure. For example, the following modifications of the embodiments are also included in the technical scope of the present disclosure.

[0057] (1) In the above embodiment 1, the first component 22 was made up of connector mounting parts 38 and terminal blocks 40, and the second component 24 was made up of the upper bottom wall part 42 and lower case 18, and the resin molded product comprising these first component 22 and second component 24 was made up of an electrical connection box 10, but the present invention is not limited to this embodiment. The specific embodiments of the first component, the second component and the resin molded product comprising them are not limited. Also, in the above embodiment 1, the second component 24 (upper bottom wall part 42) was integrally molded with the first component 22 as an insert, but the present invention is not limited to this embodiment. Furthermore, a waterproof area is not essential in the resin molded product according to the present disclosure. That is, the embedded part, groove and melt rib in the first component do not need to be provided in the part of the second component that particularly requires watertight sealing.

[0058] For example, the second component may consist only of the upper bottom wall portion, and the upper case may be a resin molded product comprising the first component (each connector mounting portion and terminal block) and the second component. Alternatively, the first component may be the upper bottom wall portion, or an integrated upper bottom wall portion and lower case. In these cases, the upper bottom wall portion, which is the first component, may be provided with an embedded portion and a groove, with a melt rib provided in the groove, while the connector mounting portion, which is the second component, may have a receiving recess that accommodates the embedded portion.

[0059] (2) In the embodiment 1 described above, each connection terminal 68 and each connector mounting portion 38 were integrally molded so that each connection terminal 68 was fixedly held by the terminal retaining wall 66 of each connector mounting portion 38. However, each connection terminal and each connector mounting portion may be formed separately, and each connection terminal may be press-fitted into a through hole provided in the terminal retaining wall of each connector mounting portion so that each connection terminal is fixedly held by the terminal retaining wall of each connector mounting portion. Alternatively, each connection terminal does not have to be fixedly held by the terminal retaining wall, and each connection terminal may be separated from the inner circumferential surface of the terminal retaining wall by a gap.

[0060] (3) In Embodiment 1, each melt rib 32 protruded from the upper bottom surface 72 of each groove 28, but the embodiment is not limited to this. Each melt rib only needs to protrude from at least one of the upper bottom surface and both sides that constitute the inner surface of each groove. Furthermore, the shape and number of each melt rib are not limited; for example, they may be cylindrical or polygonal prism shapes that taper in stages, or one or more annular melt ribs may be provided within the groove.

[0061] (4) The circuit board is not limited to being fixed to the upper case, but may also be fixed to the lower case. Furthermore, the upper case and the lower case are not limited to being fixed together by screws, but may also be fixed together by, for example, a known locking mechanism. [Explanation of symbols]

[0062] 10. Electrical junction box 12 Circuit boards 14 cases 16 Upper Case 18 Lower Case 20 Upper opening 22 Part 1 24 Part 2 26 Buried section 28 grooves 30 Molten part 32 Meltlibu 34 Through Holes 38 Connector mounting section 40 Terminal block 42 Upper bottom wall 44 Waterproof Area 46 openings 48 Penetration section 52 Bottom wall section 54 Lower peripheral wall 60 Hood section 62 Outer surface (opposing surface) 66 Terminal retaining wall 68 connection terminals 72 Upper base (bottom) 74 Terminal fastening section 76 Connection terminals 78 Terminal base 80 bolt insertion holes 82 Stud bolts 84 Outer surface (opposing surface) 88 Confinement Depression 90 Inner surface (opposite surface) 92 Containment Depression 94 Inner surface (opposite side)

Claims

1. The first component is made of synthetic resin, It comprises a second component made of synthetic resin, The first component includes an embedded portion which is embedded in and integrated with the second component, A recessed groove opening on the surface of the embedded portion facing the second part, It comprises a melt rib protruding from the groove and having a molten portion, The molten portion is welded to the second part that fills the groove, in a resin molded product.

2. The embedded portion of the first component is arranged to surround the periphery of the waterproof area of ​​the second component. The groove is formed in an annular shape surrounding the waterproof area of ​​the second component, The resin molded product according to claim 1, wherein the molten portion is welded to the second part that fills the groove over the entire circumference of the groove.

3. The resin molded article according to claim 1 or claim 2, wherein the melt rib is provided protruding from the bottom surface of the groove toward the opening side.

4. The resin molded article according to claim 3, wherein the protruding dimension of the melt rib is 2 / 3 or less of the depth dimension of the groove.

5. The second component includes a case that houses a circuit board inside, The first component includes a connector mounting portion provided in the opening of the case which serves as the waterproof area, The connector mounting portion has a hood portion that protrudes onto the case and an embedded portion that extends in a flange-like manner towards the base end of the hood portion. The resin molded product according to claim 2, wherein the embedded portion surrounds the periphery of the opening.

6. A first component made of synthetic resin, which is inserted into a second component made of synthetic resin and integrated with the second component, The embedded portion embedded in the second component, A recessed groove opening on the surface of the embedded portion facing the second part, It has a melt rib that protrudes from the groove and whose tip is a molten portion, The molten portion is the first component, which is designed to melt during the molding of the second component.

Images