Method for manufacturing resin molded article

Abstract

Provided is a method for manufacturing a resin molded body, which increases the change in the shape of a resin molded body product and prevents the deformation of an electrical conductor and the damage to a mold. A method for manufacturing a resin molded body includes: a mold preparation step of preparing a movable-side mold and a fixed-side mold; a positioning step of positioning the electrical conductor on the fixed-side mold; a closing step of closing the mold and accommodating the electrical conductor in the mold; an injection step of injecting the liquid resin into the mold; a curing step in which the resin is cured in the mold and a part of the electrical conductor is fixed to the resin; and an opening step for separating the movable-side mold from the fixed-side mold, in the mold preparation step, a mold having a groove for accommodating at least a portion of the electrical conductor is prepared, and the groove has: a groove bottom wall having a bottom wall surface in surface contact with the electrical conductor; and a pair of groove side walls having a tapered surface inclined so as to expand from the groove bottom wall toward a groove opening provided at a position facing the groove bottom wall, the height of the pair of groove side walls being half the distance between adjacent electrical conductors.

Description

Technical Field

[0001] The present invention relates to a method for producing a resin molded body. Background Art

[0002] When manufacturing a resin molded body having metal terminals inside, resin is injected into the mold while the metal terminals are arranged in the mold. At this time, the metal terminals may sometimes be deformed due to the force of the resin flow in the mold. In order to prevent the metal terminals from being crushed and deformed in the horizontal direction due to the force of the resin flow in the mold, it is known to provide a structure on the mold that locks the side of the metal terminal on the downstream side of the resin flow direction. In the structure for locking the side of the metal terminal, for example, a protrusion located between a plurality of metal terminals is sometimes used. This structure in the injection molding of thermoplastic resins can generally only be provided on the mold on the fixed side where the metal terminal is provided, and therefore becomes a limitation when designing the product shape of the resin molded body. Prior art literature Patent Literature

[0003] Patent Document 1: Japanese Patent Application Publication No. 2003-163303 Patent Document 2: Japanese Patent Application Publication No. 2010-190596 Summary of the invention Problem that the invention aims to solve

[0004] In order to form an exposed surface on the metal terminal for bonding the metal terminal and the circuit substrate by wire bonding or the like, the mounting portion of the metal terminal provided on the fixed side mold (usually the lower mold) has a surface in close contact with the metal terminal. Specifically, the mounting portion is a groove for the metal terminal to be embedded, and the fixed side mold has a protrusion located between the metal terminals, which has the following functions: locking the side surface of the metal terminal on the downstream side of the resin flow direction and preventing deformation of the metal terminal in the horizontal direction.

[0005] The side structure (e.g., protrusion) of the metal terminal is generally provided on the fixed side mold. Assuming that the side protrusion of the metal terminal is provided on the movable side mold (upper mold), the movable side mold approaches the metal terminal as an insertion component provided on the fixed side mold (lower mold) in a manner of covering the groove forming the exposed surface and inserting the protrusion between the metal terminals relative to the fixed side mold. In this case, due to the size change and positional displacement of the metal terminal as the insertion component, the protrusion of the movable side mold contacts the metal terminal, and there is a possibility of deformation of the metal terminal, foreign matter (burrs, cracks, etc.), and other molding defects and mold damage. Therefore, the side structure of the metal terminal is usually mostly provided in parallel on the fixed side mold, which becomes the main reason for the limitation of the change of the product shape of the resin molded body.

[0006] Patent Document 1 describes a technique for positioning the arrangement direction and thickness direction of each lead terminal in the concave portion of the second mold by clamping the lead frame from above and below with a first mold and a second mold. In the technique described in Patent Document 1, the mounting base is molded while the lead terminal is positioned in the concave portion so as not to be displaced laterally. However, since the lead terminal is positioned in the concave portion while contacting the wall surface of the concave portion of the second mold, there is a possibility that the lead terminal may be deformed or the mold may be damaged.

[0007] Patent Document 2 describes a technique in which a concave portion for embedding a metal terminal is formed on an upper mold constituting a resin molding mold, a pin that contacts the back surface of the metal terminal is formed on a lower mold, and the metal terminal is clamped by the concave portion and the pin. However, in the technique described in Patent Document 2, when the metal terminal is embedded in the concave portion of the upper mold, the upper mold contacts the metal terminal, which may cause deformation of the metal terminal or damage to the mold.

[0008] The present invention has been made in view of the above circumstances, and an object thereof is to provide a method for producing a resin molded body, which method can increase the variation of the product shape of the resin molded body and prevent deformation of the electric conductor and damage to the mold. Technical means of solving problems

[0009] In order to solve the above-mentioned problems, a method for manufacturing a resin molded body of the present invention is a method for manufacturing a resin molded body in which an electric conductor is arranged in a mold and a resin is injected. The method for manufacturing a resin molded body is characterized in that it includes: a mold preparation step of preparing a movable side mold and a fixed side mold as the mold; a positioning step of positioning a part of the electric conductor on the fixed side mold; a closing step of closing the mold by bringing the movable side mold into contact with the fixed side mold to accommodate the electric conductor in the mold; an injection step of injecting a liquefied resin into the mold; and a curing step of The resin is solidified in the mold to fix a part of the electrical conductor on the resin; and an opening step is performed to separate the movable side mold from the fixed side mold. In the mold preparation step, a mold having a groove for accommodating at least a part of the electrical conductor is prepared as the mold, the groove having: a groove bottom wall having a bottom wall surface in contact with the surface of the electrical conductor; and a pair of groove side walls having a tapered surface inclined in a manner extending from the groove bottom wall to a groove opening provided at a position opposite to the groove bottom wall, and the height of the pair of groove side walls is half the distance between adjacent electrical conductors. Effects of the Invention

[0010] According to the method for manufacturing a resin molded body of the present invention, it is possible to prevent deformation of the electrical conductor and damage to the mold while increasing the variation of the product shape of the resin molded body. Further features related to the present invention will become clear from the description of this specification and the accompanying drawings. In addition, the above-mentioned problems, structures and effects will be further clarified through the description of the following embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 This is an overall view of a resin molded body produced by the production method of the present invention. Figure 2 yes Figure 1 AA cross-section diagram. Figure 3 The diagrams illustrate the steps of the production method according to the first embodiment of the present invention. Figure 4 Yes Description Figure 3 An enlarged cross-sectional view of one step of the manufacturing method is shown. Figure 5 Yes Description Figure 3 An enlarged cross-sectional view of one step of the manufacturing method is shown. Figure 6 Yes Description Figure 3 Graph showing the migration prevention effect of the manufacturing method shown. Figure 7 It is an enlarged cross-sectional view for explaining a mold used in a production method according to a second embodiment of the present invention. Figure 8 It is an enlarged cross-sectional view for explaining a mold used in a production method according to a third embodiment of the present invention. Fig. 9 It is an enlarged cross-sectional view for explaining a mold used in a production method according to a fourth embodiment of the present invention. Fig.10 It is an enlarged cross-sectional view for explaining a mold used in a production method according to a fifth embodiment of the present invention. Fig.11 This is an enlarged cross-sectional view illustrating one step of a conventional manufacturing method. Fig.12 It is a description of Fig.11 The steps shown are enlarged cross-sectional views of different steps. Fig.13 This is an enlarged cross-sectional view illustrating one step of another conventional manufacturing method. Fig.14 It is a description of Fig.13 The steps shown are enlarged cross-sectional views of different steps. Fig.15 This is a diagram for explaining migration in a conventional manufacturing method. DETAILED DESCRIPTION

[0012] Hereinafter, a method for producing a resin molded body according to an embodiment of the present invention will be described in detail with reference to the drawings.

[0013] First, refer to Figure 1 and Figure 2 , an airflow sensor (resin molded body) 1 manufactured by a manufacturing method according to an embodiment of the present invention will be described. Figure 1 1 is an overall view of the airflow sensor 1 manufactured by the manufacturing method of the present invention. Figure 2 yes Figure 1 AA cross-section diagram.

[0014] like Figure 1 As shown, the airflow sensor 1 includes: a resin body portion 1a, a metal terminal (electric conductor) 2 as an insertion component, and a substrate 17 electrically connected to the metal terminal 2. The metal terminal 2 is electrically connected to an external control device (not shown) at one end. One end of the metal terminal 2 is located on the connector portion 6 of the resin body portion 1a.

[0015] like Figure 1 and Figure 2 As shown, the metal terminal 2 is electrically connected to the substrate 17 via the aluminum wire 4 at the other end. The metal terminal 2 has an exposed surface 3 at the other end that is not covered by the resin body portion 1a. The exposed surface 3 is a portion of the metal terminal 2 that is exposed to the outside from the resin body portion 1a. On the exposed surface 3, the aluminum wire 4 is welded (wire-bonded) to electrically connect the metal terminal 2 and the substrate 17. In order to form the exposed surface 3 at the other end of the metal terminal 2, a groove 7 is provided on the mold 15 described later for manufacturing the airflow sensor 1. In addition, a gate 5 is formed on the airflow sensor 1, as shown in FIG. Figure 2 As shown in the resin flow 8, the resin is injected into the mold 15 from the gate 5.

[0016] Here, a conventional method for producing a resin molded body will be described. Fig.11 This is an enlarged cross-sectional view illustrating one step of a conventional manufacturing method. Fig.12 It is a description of Fig.11 The process shown is an enlarged cross-sectional view of different processes. Fig.11 and Fig.12 In the following, a case where the groove 10 c for arranging the metal terminal 2 is provided in the fixed side mold 10 is described.

[0017] like Fig.11As shown, the mold 15 has a fixed side mold 10 (also called a lower mold) and a movable side mold 9 (also called an upper mold). In the past, it was widely used to form a groove 10c for fitting the metal terminal 2 on the fixed side mold (also called a lower mold) 10, and the metal terminal 2 was set in the groove 10c for injection molding to form the airflow sensor 1. The shape between the adjacent grooves 10c of the fixed side mold 10, that is, between the metal terminals 2, becomes a protrusion shape 10b. In this way, since the metal terminal 2 is set on the fixed side mold 10 for injection molding, the exposed surface 3 of the metal terminal 2 is generally formed by the fixed side mold 10.

[0018] like Fig.12 As shown, the protrusion shape 10b is located between the metal terminals 2, and when the mold 15 is closed, the metal terminal 2 is constrained in the up and down directions by the fixing pin 9p and the groove 10c. Therefore, even when the resin is injected into the mold 15 and the resin flow 8 is generated in the mold 15, the metal terminal 2 is suppressed from being hit by the resin flow 8 and causing the metal terminal 2 to deform in the horizontal direction. In addition, the depth of the groove 10c is formed to be shallower than the thickness of the metal terminal 2. As a result, the surface other than the exposed surface 3 of the metal terminal 2 (including a part of the side 2a) is covered with resin. Therefore, since the metal terminal 2 is fixed on the resin main body 1a, after molding, when the aluminum wire 4 is welded to the exposed surface 3 of the metal terminal 2, the deformation of the metal terminal 2 can be avoided.

[0019] Conventionally, it has been difficult to provide the movable mold (upper mold) 9 with the groove 10 c into which the metal terminal 2 is fitted from the viewpoint of mold protection. Fig.13 This is an enlarged cross-sectional view illustrating one step of another conventional manufacturing method. Fig.14 It is a description of Fig.13 The process shown is an enlarged cross-sectional view of different processes. Fig.13 and Fig.14 In the following, a case where the movable die 9 is provided with the groove 9d for providing the metal terminal 2 is described.

[0020] like Fig.14 As shown in FIG. 1 , when the movable side mold 9 is brought close to the fixed side mold 10 and the mold 15 is closed, the protrusion shape 9f formed between the grooves 9d is inserted between the metal terminals 2. In addition, in the state of the closed mold 15, the metal terminals 2 are constrained in the vertical direction by the fixing pins 10d and the grooves 9d. Due to the dimensional change and deformation of the metal terminal 2, when the metal terminal 2 leaves the fixed position 19 relative to the groove 9d, the protrusion shape 9f of the movable side mold 9 collides with the metal terminal 2, and sometimes both are damaged.

[0021] In order to avoid damage to the metal terminal 2 and the mold 15, a groove for fitting the metal terminal 2 is usually provided on the fixed side mold 10, and in the past, the exposed surface 3 of the metal terminal 2 was generally formed by the fixed side mold 10. Therefore, as the product shape of the airflow sensor 1, it is necessary to select a shape in which the exposed surface 3 of the metal terminal 2 is formed by the fixed side mold 10, which becomes a limitation to the variation of the product shape of the airflow sensor 1.

[0022] (First Embodiment) The manufacturing method of the resin molded body of the first embodiment is described. In addition, in this embodiment, although the groove 7 is formed on the movable side mold 9, the groove 7 may be formed on the fixed side mold 10. The manufacturing method of this embodiment is a method of placing the metal terminal (electric conductor) 2 in the mold 15, injecting resin, and molding the airflow sensor 1.

[0023] Figure 3 The diagrams illustrate the steps of the production method according to the first embodiment of the present invention. Figure 4 Yes Description Figure 3 An enlarged cross-sectional view of one step of the manufacturing method is shown. Figure 5 Yes Description Figure 3 An enlarged cross-sectional view of one step of the manufacturing method is shown. Figure 6 Yes Description Figure 3 Graph showing the migration prevention effect of the manufacturing method shown.

[0024] like Figure 3 As shown, the manufacturing method of the airflow sensor 1 of the first embodiment includes: a mold preparation step S1, a positioning step S2, a closing step S3, an injection step S4, a curing step S5 and an opening step S6.

[0025] The mold preparation step S1 is a step of preparing the movable side mold 9 and the fixed side mold 10 as the mold 15. Figure 4 and Figure 5 As shown, the mold 15 has a groove 7 on the movable side mold 9 for accommodating at least a portion of the metal terminal 2 when the mold 15 is closed. The groove 7 includes: a groove bottom wall 7g, which has a bottom wall surface 9g that contacts the metal terminal 2; and a pair of groove side walls 7b, 7b, which have a tapered surface 9b that is inclined to expand from the groove bottom wall 7g toward the groove opening 7a provided at a position opposite to the groove bottom wall 7g. The pair of groove side walls 7b, 7b are connected to the groove bottom wall 7g at one end. The bottom wall surface 9g and the pair of tapered surfaces 9b, 9b are formed toward the groove interior of the groove 7. The groove 7 has a groove opening 7a at a position opposite to the bottom wall surface 9g.

[0026] By tilting the pair of groove side walls 7b, 7b, the resin can be filled into the space between the side surface 2a of the metal terminal 2 and the tapered surface 9b in the injection step S4 described later. By filling the side surface 2a of the metal terminal 2 with resin, the amount of resin covering the metal terminal 2 after molding increases, and the fixing force of the metal terminal 2 by the resin is improved. Figure 6 As shown, by covering the side surface 2a of the metal terminal 2 with resin, a structure is formed in which the water droplets 150 do not adhere to the side surface 2a of the metal terminal 2, and the distance until a short circuit due to migration occurs can be increased. Fig.15 Compared with the conventional manufacturing method shown, the risk of migration caused by water droplets 150 adhering between metal terminals 2 can be reduced. In addition, by fixing metal terminals 2 more firmly, substrate 17 and metal terminals 2 can be welded more reliably by aluminum wires 4.

[0027] In the movable side mold 9, a top wall surface 9c is formed between adjacent grooves 7. The top wall surface 9c is a part of the top wall 7c, and the top wall 7c connects the other end sides of the groove side walls 7b and 7b of the adjacent grooves 7. The top wall surface 9c is a surface facing the same direction as the bottom wall surface 9g. The top wall surface 9c can be formed to be convexly curved toward the fixed side mold 10, or it can be formed to be flat. The top wall 7c is positioned offset relative to the groove bottom wall 7g in the arrangement direction of the metal terminal 2. In this way, the movable side mold 9 of this embodiment is repeatedly provided with the groove bottom wall 7g, the groove side wall 7b, the top wall 7c, the groove side wall 7b, and the groove bottom wall 7g.

[0028] Since the base 20 of the pair of groove side walls 7 b and 7 b locks the corner of the metal terminal 2 on the exposed surface 3 side, the metal terminal 2 can be restricted in the horizontal direction with respect to the direction of the resin flow 8 .

[0029] In the present embodiment, the height 17b of a pair of groove side walls 7b, 7b is half of the distance 17a between adjacent metal terminals 2. The higher the height 17b of the groove side wall 7b, the better the effect of preventing the metal terminal 2 from being deformed due to the collision with the movable side mold 9. However, from the viewpoint of suppressing the reduction in the strength of the movable side mold 9, the height 17b of the groove side wall 7b is preferably half of the distance 17a between the metal terminals 2. The inventors have the following understanding: the height 17b of the groove side wall 7b of the mold 15 is preferably about 70% relative to the width of the distance 17a between the metal terminals 2. In the case of setting the groove side wall 7b with a height exceeding 70% relative to the distance 17a between the metal terminals 2, the risk of damage to the mold 15 may increase.

[0030] The inclination angle 18 of the pair of groove side walls 7b, 7b is in the vertical direction of the movable side mold 9 ( Figure 4) is used as a reference, preferably 25° to 45°. The smaller the inclination angle 18 of a pair of groove side walls 7b, 7b, the higher the effect of locking the metal terminal 2, but in order to avoid the sticky resin material not being filled, the inclination angle 18 is preferably greater than 25°. In addition, if the inclination angle 18 is greater than 45°, when the mold 15 is closed, when the metal terminal 2 contacts the tapered surface 9b, the force pushing the metal terminal 2 in the vertical direction is more dominant than the force moving the metal terminal 2 in the horizontal direction. Therefore, the effect of guiding the metal terminal 2 to the fixed position 19 by the tapered surface 9b becomes smaller. Therefore, the inclination angle 18 is preferably less than 45°.

[0031] In addition, the height 17b of the pair of groove side walls 7b, 7b is preferably half the thickness 17c of the metal terminal 2. This can reduce the area where the resin injected from the gate 5 into the mold 15 directly collides with the side surface 2a of the metal terminal 2, and by reducing the horizontal stress applied to the metal terminal 2, it is possible to prevent the deformation of the metal terminal 2 caused by the resin flow 8.

[0032] like Figure 4 and Figure 5 As shown, in the mold preparation process, a mold 15 is prepared, and the mold 15 is provided with a flow change portion 10a at a position of the fixed side mold 10 opposite to the bottom wall surface 9g of the movable side mold 9. The flow change portion 10a has a collision surface 10n, and the collision surface 10n collides with the liquefied resin injected in the injection process S4. The collision surface 10n changes the direction of the resin flow 8 at least partially toward the covering surface 3a of the metal terminal 2. Therefore, when the resin flow 8 is generated in the state where the mold 15 is closed, the movement of the metal terminal 2 in the up and down direction is restricted by the resin flow 8 and the bottom wall surface 9g.

[0033] As described above, the fixed side mold 10 is not provided with the fixing pin 10d ( Fig.13 , Fig.14 ). Thus, the metal terminal 2 is clamped by the bottom wall surface 9g of the movable side mold 9 for forming the exposed surface 3 of the metal terminal 2 and the fixing pin 10d, so that the risk of damage to the metal terminal 2 can be reduced.

[0034] like Figure 4 As shown, the positioning step S2 is a step of positioning a part of the metal terminal 2 on the fixed side mold 10. The metal terminal 2 is fixed to the fixed side mold 10 at one end and the other end. For example, one end (connector part 6 side) of the metal terminal 2 can be fixed to the fixed side mold 10 by a sliding block. In addition, the other end (exposed surface 3 side) of the metal terminal 2 can also be fixed to the fixed side mold 10 by inserting the other end into a pin.

[0035] The closing step S3 is a step of closing the mold 15 by bringing the movable side mold 9 into contact with the fixed side mold 10, and accommodating the metal terminal 2 in the mold 15. In the closing step S3, when the metal terminal 2 contacts the bottom wall surface 9g forming the exposed surface 3, when the metal terminal 2 is not in the fixed position 19 relative to the groove 7, the metal terminal 2 contacts the tapered surface 9b, and the metal terminal 2 can be guided to the bottom wall surface 9g along the tapered surface 9b without clamping the metal terminal 2 by the mold 15.

[0036] like Figure 5 As shown, the injection step S4 is a step of injecting a liquefied resin into the mold 15. In the present embodiment, as the resin injected into the mold 15, not only a thermoplastic resin but also a thermosetting resin can be used.

[0037] The curing step S5 is a step of curing the resin in the mold 15 to fix a part of the metal terminal 2 to the resin. In the injection step, when the thermoplastic resin is injected into the mold 15, the resin is cured by cooling.

[0038] The opening step S6 is a step of separating the movable side mold 9 from the fixed side mold 10 .

[0039] According to the manufacturing method of this embodiment, the groove 7 for accommodating a part of the metal terminal 2 is formed in the movable side mold 9. Therefore, in the positioning step S2, even if the position displacement, dimensional change, deformation, etc. of the metal terminal 2 occur, these changes can be flexibly absorbed, and the metal terminal 2 is guided to the groove bottom wall 7g by the tapered surface 9b. Therefore, in the closing step S3, the damage, deformation, foreign matter, etc. of the mold 15 and the metal terminal 2 caused by the collision between the metal terminal 2 and the movable side mold 9 can be improved, and the structure of the metal terminal 2 can be set without restricting the fixed side mold 10 and the movable side mold 9.

[0040] In addition, since the height 17b of the pair of groove side walls 7b, 7b is set to half the distance 17a between the adjacent metal terminals 2, a structure (the root 20 of the pair of groove side walls 7b, 7b) that locks the metal terminal 2 can be obtained, and the strength of the movable side mold 9 can be prevented from being excessively increased. Therefore, even when the metal terminal 2 contacts the groove side wall 7b, deformation of the metal terminal 2, damage to the mold 15 and the metal terminal 2, etc. can be avoided. In this way, even if the groove 7 is provided on the movable side mold 9, the mold 15 and the metal terminal 2 will not be damaged. Therefore, the product shape of the airflow sensor 1 in the direction of the exposed surface 3 of the metal terminal 2 formed by the movable side mold 9 can be selected, and the variation of the product shape can be expanded.

[0041] (Second Embodiment) Next, a second embodiment of the present invention will be described. Figure 7 It is an enlarged cross-sectional view for explaining a mold 15 used in the production method according to the second embodiment of the present invention.

[0042] In the manufacturing method of the second embodiment, in the mold preparation step S1, a mold 15 having the following structure is prepared as the mold 15: a pair of groove side walls 7b, 7b have a groove bottom side tapered surface 11a located on the groove bottom wall 7g side and an opening side tapered surface 11b continuous with the groove bottom side tapered surface 11a and located on the groove opening 7a side as tapered surfaces. The angle between the side surface 2a of the metal terminal 2 perpendicular to the bottom wall surface 9g and the opening side tapered surface 11b is 45 degrees or less. The angle between the side surface 2a of the metal terminal 2 and the groove bottom side tapered surface 11a is smaller than the angle between the side surface 2a of the metal terminal 2 and the opening side tapered surface 11b. In this way, the movable side mold 9 has two stages of tapered surfaces 11a, 11b with different angles as tapered surfaces of a pair of groove side walls 7b, 7b. In addition, the tapered surfaces of a pair of groove side walls 7b, 7b may also be tapered surfaces with three or more stages of different angles.

[0043] By making the side surface 2a of the metal terminal 2 perpendicular to the bottom wall surface 9g as a reference, the opening side tapered surface 11b is made larger in angle than the groove bottom side tapered surface 11a, and since the groove opening 7a is widened, it is easy to make the metal terminal 2 contact with the opening side tapered surface 11b, and it is easy to insert the metal terminal 2 into the groove 7. In addition, by making the angle of the groove bottom side tapered surface 11a smaller than the angle of the opening side tapered surface 11b, a structure that easily locks the metal terminal 2 can be formed.

[0044] (Third Embodiment) Next, a third embodiment of the present invention will be described. Figure 8 It is an enlarged cross-sectional view for explaining a mold 15 used in a production method according to a third embodiment of the present invention.

[0045] In the manufacturing method of the third embodiment, in the mold preparation step S1, a mold 15 in which the portion 12 of a pair of groove side walls 7b, 7b located on the groove bottom wall 7g side is formed into a cross-sectional R shape is prepared as the mold 15. In this way, the pair of groove side walls 7b, 7b are connected to the groove bottom wall 7g via the R-shaped portion 12 at one end.

[0046] By providing the R-shaped portion 12 that smoothly connects the groove side walls 7b, 7b and the groove bottom wall 7g, the strength of the movable side mold 9 is improved. In addition, since the resin filled on the side surface 2a of the metal terminal 2 can be increased, the fixing strength of the metal terminal 2 relative to the resin body 1a can be improved.

[0047] (Fourth Embodiment) Next, a fourth embodiment of the present invention will be described. Fig. 9FIG. 1 is an enlarged cross-sectional view of a mold 15 used in a manufacturing method according to a fourth embodiment of the present invention. Fig. 9 , the case where the opening side tapered surface 13 a and the vertical surface 13 b are provided on the fixed side mold 10 is illustrated, but the opening side tapered surface 13 a and the vertical surface 13 b may also be provided on the movable side mold 9 .

[0048] In the manufacturing method of the fourth embodiment, in the mold preparation step S1, a mold is prepared as a mold 15 in which a pair of groove side walls 18b, 18b have an opening side tapered surface 13a located on the groove opening 7a side as a tapered surface. In addition, a mold 15 is prepared in which a pair of groove side walls 18b, 18b have a vertical surface 13b that is continuous with the opening side tapered surface 13a and located on the groove bottom wall 18g side. The vertical surface 13b is a surface that is perpendicular to the bottom wall surface 10g and is formed toward the inside of the groove 7. In this way, the mold 15 is configured as follows: the opening side tapered surface 13a is provided on the groove opening 7a side of the groove 7 for inserting the metal terminal 2, and the vertical surface 13b that extends continuously from the tapered surface 13a to the bottom wall surface 10g is provided.

[0049] An opening side tapered surface 13a is provided on the groove opening 7a side of the groove 7, and by enlarging the groove opening 7a, the metal terminal 2 is easily inserted into the groove 7. In addition, by providing a vertical surface 13b located on the groove bottom wall 18g side, the effect of preventing the metal terminal 2 from deforming in the horizontal direction due to the resin flow 8 can be further improved.

[0050] (Fifth Embodiment) Next, a fifth embodiment of the present invention will be described. Fig.10 It is an enlarged cross-sectional view for explaining a mold 15 used in a production method according to a fifth embodiment of the present invention.

[0051] In the manufacturing method of the fifth embodiment, in the mold preparation step S1, a mold 15 formed by bending the top wall surface 9c of the top wall 7c is prepared as the mold 15. Specifically, the top wall surface 9c is formed to have an R shape convex toward the fixed side mold 10.

[0052] By making the top wall surface 9c of the movable side mold 9 into an R shape as described above, the strength of the movable side mold 9 is improved. The sharp edge portion can be eliminated from the movable side mold 9, and when the top wall 7c is inserted between the metal terminals 2, even if the top wall surface 9c contacts the metal terminals 2, it is possible to suppress damage to the metal terminals 2 and the movable side mold 9. In addition, foreign matter in the metal terminals 2 caused by dents, plating peeling, etc. can be reduced.

[0053] The embodiments of the present invention are described in detail above, but the present invention is not limited to the embodiments described above, and various design changes can be made without departing from the spirit of the present invention recorded in the technical solution. For example, the embodiments described above are embodiments that are described in detail in order to easily explain the present invention, and are not necessarily limited to embodiments having all the described structures. In addition, a part of the structure of an embodiment can be replaced with the structure of other embodiments, or the structure of other embodiments can be added to the structure of one embodiment. Furthermore, for a part of the structure of each embodiment, other structures can be added, deleted, or replaced. Explanation of symbols

[0054] 1: resin molded body (air flow sensor), 2: metal terminal (electrical conductor), 7: groove, 7a: groove opening, 7b: a pair of groove side walls, 7g: groove bottom wall, 9b: tapered surface, 9g: bottom wall surface, 10a: flow changing portion, 11a: groove bottom side tapered surface, 11b: opening side tapered surface, 12: R-shaped portion, 17a: distance between metal terminals, 17b: height of groove side wall, 17c: height of metal terminal, 9: movable side mold, 10: fixed side mold, 15: mold, S1: mold preparation process, S2: positioning process, S3: closing process, S4: injection process, S5: curing process, S6: opening process.

Claims

1. A method for producing a resin molded body, wherein an electric conductor is arranged in a mold and a resin is injected, the method for producing a resin molded body comprising: A mold preparation step of preparing a movable side mold and a fixed side mold as the mold; A positioning step of positioning a portion of the electrical conductor on the fixed side mold; a closing step of closing the mold by bringing the movable mold into contact with the fixed mold to accommodate the electrical conductor in the mold; An injection step of injecting liquefied resin into the mold; a curing step of curing the resin in the mold to fix a portion of the electrical conductor to the resin; as well as an opening step of separating the movable side mold from the fixed side mold, In the mold preparation step, a mold having a groove for accommodating at least a portion of the electrical conductor is prepared as the mold, wherein the groove has: a groove bottom wall having a bottom wall surface in surface contact with the electrical conductor; and a pair of groove side walls having tapered surfaces inclined so as to expand from the groove bottom wall toward a groove opening disposed at a position opposite to the groove bottom wall, wherein the height of the pair of groove side walls is half the distance between adjacent electrical conductors.

2. The method for producing a resin molded body according to claim 1, wherein In the mold preparation step, a mold in which the height of the pair of groove side walls is half the thickness of the electrical conductor is prepared as the mold.

3. The method for producing a resin molded body according to claim 1, wherein: In the mold preparation step, the following mold is prepared as the mold, in which the conical surface has: a groove bottom side conical surface located on the groove bottom wall side, and an opening side conical surface continuous with the groove bottom side conical surface and located on the groove opening side, the angle between the side surface of the conductor perpendicular to the bottom wall surface and the opening side conical surface is less than 45 degrees, and the angle between the side surface of the conductor and the groove bottom side conical surface is smaller than the angle between the side surface of the conductor and the opening side conical surface.

4. The method for producing a resin molded body according to claim 1, wherein: In the mold preparation step, a mold in which portions of the pair of groove side walls located on the groove bottom wall side are formed in an R-shaped cross section is prepared as the mold.

5. The method for producing a resin molded body according to claim 1, wherein: In the mold preparation step, a mold having a flow change portion is prepared as the mold. The flow change portion is provided at a position opposite to the bottom wall surface and collides with the liquefied resin injected in the injection step, thereby at least partially changing the flow direction of the resin toward the electrical conductor.

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