Mold and method for producing molded article

Abstract

A mold (1) used for obtaining an electronic control device (100) has: a cavity (8) for molding the electronic control device (100); and an overhanging part (32) facing the cavity (8) and oriented toward a bottom part (2) of the cavity (8).

Description

Molding Die and Method for Manufacturing Molded Product

[0001] The present invention relates to a molding die used to obtain a molded product and a method for manufacturing the molded product obtained using this molding die.

[0002] In recent years, in vehicles such as automobiles, an electronic control device for controlling the operating state of an electric motor or the operating state of vehicle-mounted components has come to be used. In such an electronic control device, in order to protect a circuit board or electronic components, etc., it is common to adopt a configuration in which the periphery of the circuit board or electronic components, etc. is covered with resin.

[0003] Under such circumstances, Patent Document 1 discloses, in a conventional example, a method for manufacturing an electronic circuit block in which a part of a substrate is inserted into a resin receiving container, resin is poured into the resin receiving container from an upper opening, and the resin is injected so that the liquid surface of the resin reaches a position for sealing the electronic components mounted on the substrate, and after the resin is solidified or cured, the electronic circuit block is removed from the resin receiving container.

[0004] Japanese Patent Application Laid-Open No. 2001-210960

[0005] However, in Patent Document 1, since an edge portion is formed outside the upper end portion of the molded product, there is a problem that the edge portion cracks or chips during mold release or the like. In particular, when an edge portion having an acute angle is formed outside the upper end portion of the molded product, the above problem becomes prominent.

[0006] An object of the present invention is to provide a molding die and a method for manufacturing a molded product that can suppress cracking or chipping of an edge portion at the upper end portion of the molded product.

[0007] To achieve the above object, one aspect of the present invention is a molding die used to obtain a molded product, which has a cavity for molding the molded product and a first wall portion facing the cavity and facing the bottom of the cavity.

[0008] According to one aspect of the present invention, a molding die used to obtain a molded product has a cavity for molding the product and a first wall portion that faces the cavity and is directed toward the bottom of the cavity, thereby preventing the edge portion of the upper end of the molded product from cracking or chipping.

[0009] Figure 1 is a side view of a molding die according to the first embodiment of the present invention. Figure 2 is a plan view of a molding die according to the first embodiment of the present invention. Figure 3 is a cross-sectional view taken along line A-A in Figure 2. Figure 4 is a cross-sectional view of a molded product formed by a molding die according to the first embodiment of the present invention. Figure 5 is a cross-sectional view of a part of a molded product formed by a molding die according to the first embodiment of the present invention. Figure 6 is a cross-sectional view of a molding die according to the second embodiment of the present invention. Figure 7 is a cross-sectional view of a part of a molded product formed by a molding die according to the second embodiment of the present invention. Figure 8 is a cross-sectional view of a part of a molding die according to the third embodiment of the present invention. Figure 9 is a cross-sectional view of a part of a molded product formed by a molding die according to the third embodiment of the present invention.

[0010] Hereinafter, the molding die in the embodiment of the present invention will be described in detail with reference to the drawings as appropriate. In the drawings, the x, y, and z axes form a three-axis orthogonal coordinate system, with the positive direction of the y axis being the forward direction, the negative direction of the y axis being the backward direction, the positive direction of the x axis being the right direction, the negative direction of the x axis being the left direction, the positive direction of the z axis being the upward direction, and the negative direction of the z axis being the downward direction.

[0011] (First Embodiment) <Configuration of the Molding Mold> The configuration of the molding mold 1 according to the first embodiment of the present invention will be described in detail with reference to Figures 1 to 3.

[0012] The molding die 1 is integrally formed from a flexible and breakable sheet-like or plate-like member such as a synthetic resin material, and has a bottom portion 2, a right side wall portion 3, a left side wall portion 4, an inclined wall portion 5, a front wall portion 6, a rear wall portion 7, a cavity 8, an opening 9, a protrusion 10, a row of recesses 31, and an overhang 32. The bottom portion 2, the right side wall portion 3, the left side wall portion 4, the inclined wall portion 5, the front wall portion 6, and the rear wall portion 7 constitute the cavity 8.

[0013] The bottom portion 2 has its longitudinal direction in the front-to-back direction and its short direction in the left-to-right direction. The bottom portion 2 connects the lower end of the right side wall portion 3, the lower end of the inclined wall portion 5, the lower end of the front wall portion 6, and the lower end of the rear wall portion 7. The bottom portion 2 constitutes the bottom of the cavity 8, which closes the lower end side of the cavity 8.

[0014] The right side wall 3 connects the front end of the bottom 2, the right end of the front wall 6, and the right end of the rear wall 7. The right side wall 3 is connected to the bottom 2 side relative to the overhang 32. The right side wall 3 faces the left side wall 4. The right side wall 3 faces the cavity 8.

[0015] The left side wall section 4 connects the upper end of the inclined wall section 5, the left end of the front wall section 6, and the left end of the rear wall section 7. The left side wall section 4 is connected to the bottom section 2 side of the overhang section 32. The left side wall section 4 faces the right side wall section 3. The left side wall section 4 faces the cavity 8.

[0016] The inclined wall section 5 connects the left end of the bottom section 2, the lower end of the left side wall section 4, the left end of the front wall section 6, and the left end of the rear wall section 7. The inclined wall section 5 slopes downward from the lower end of the left side wall section 4 towards the right side wall section 3. The inclined wall section 5 faces the cavity 8.

[0017] The front wall 6 connects the front end of the right wall 3, the front end of the left wall 4, and the front end of the bottom 2. The front wall 6 is connected to the bottom 2 side of the overhang 32. The front wall 6 faces the rear wall 7. The front wall 6 faces the cavity 8.

[0018] The rear wall 7 connects the rear end of the right wall 3, the rear end of the left wall 4, and the rear end of the bottom 2. The rear wall 7 is connected to the bottom 2 side relative to the overhang 32. The rear wall 7 faces the front wall 6. The rear wall 7 faces the cavity 8.

[0019] Cavity 8 is a space enclosed by the bottom portion 2, the right side wall portion 3, the left side wall portion 4, the inclined wall portion 5, the front wall portion 6, and the rear wall portion 7. Cavity 8 is used to mold the electronic control device 100, which will be described later, as a molded product.

[0020] The opening 9 connects the upper side of the cavity 8 to the outside.

[0021] The protrusion 10 extends to the right from the upper end of the right side wall 3, increasing the thickness of the right side wall 3. The protrusion 10 is provided from the viewpoint of improving the strength of the right side wall 3 and improving the grip of the worker.

[0022] The row of recesses 31 is formed continuously from the lower end of the right side wall portion 3, through the upper end of the right side wall portion 3, to the right end of the protrusion 10. The row of recesses 31 is formed in pairs with a gap between them in the front and back. Note that the row of recesses 31 is not limited to being formed in pairs; one or three or more may be formed.

[0023] The protruding portion 32, which serves as a wall or first wall, is bent inward from the upper ends of each of the right wall portion 3, left wall portion 4, front wall portion 6, and rear wall portion 7 at an angle of approximately 90 degrees relative to each of the right wall portion 3, left wall portion 4, front wall portion 6, and rear wall portion 7, and protrudes into the cavity 8, while also facing the cavity 8. The protruding portion 32 is provided along the opening 9.

[0024] The mold 1 having the above configuration is a container-shaped member into which molten potting resin material is injected from the opening 9 into the cavity 8, and which can accommodate the potting resin material inside the cavity 8. It is used when manufacturing an electronic control device 100.

[0025] <Method for Manufacturing an Electronic Control Device> A method for manufacturing an electronic control device 100 using a molding die 1 according to the first embodiment of the present invention will be described in detail with reference to Figures 1 to 5.

[0026] Here, the electronic control device 100 as a molded product is a control device such as an ECU (Electronic Control Unit) that controls the operating state of a drive source such as an internal combustion engine or electric motor of a vehicle such as an automobile, and has a configuration in which a part of the device body C is protected by a potting resin body 200. Specifically, the device body C includes, as an example, a circuit board 101 having a conductive part (not shown), various electronic components 102a, 102b, 102c and 102d such as a CPU (Central Processing Unit), memory and capacitor mounted on the circuit board 101, and a connector 103 in which a pin terminal 103a that electrically connects the conductive part of the circuit board 101 to an external connection device (not shown) is surrounded by a mating part 103b. Furthermore, the circuit board 101, electronic components 102a, 102b, 102c, 102d, and a portion of the pin terminals 103a of the device body C are protected by a potting resin body 200.

[0027] First, the device body C is positioned in a predetermined location within the cavity 8 of the molding mold 1. Then, molten potting resin material, as a liquid material, is supplied from the opening 9 into the gaps between the device body C and each of the bottom 2, right side wall 3, left side wall 4, inclined wall 5, front wall 6, and rear wall 7, until the protruding portion 32 is submerged in the molten potting resin material, and the gaps are filled by gravity. Here, the position where the protruding portion 32 is submerged in the molten potting resin material is above the lower end of the protruding portion 32. As a result, the entire circuit board 101, electronic components 102a, 102b, 102c, and 102d are submerged in the potting resin material, while only a portion of the connector 103 on the circuit board 101 side is submerged in the potting resin material.

[0028] Next, after a predetermined time has elapsed under predetermined environmental conditions, the potting resin material filled in the gaps between the main body of the device C and each of the bottom 2, right side wall 3, left side wall 4, inclined wall 5, front wall 6, and rear wall 7 hardens, and as shown in Figure 4, the main body of the device C and the potting resin body 200 become one, resulting in an electronic control device 100 in which the main body of the device C is protected by the potting resin body 200.

[0029] Next, for example, an external force is applied to the right side wall 3 such that a tensile force acting in the front-rear direction and a tensile force acting in the left-right direction are applied, and the row of recesses 31 is pulled in the front-rear direction, concentrating stress in the row of recesses 31. As a result, the right side wall 3 breaks starting from the row of recesses 31, and the molding die 1 is split, so the electronic control device 100 can be removed from the molding die 1. At this time, the shape of the potting resin body 200 is molded to match the shape of the cavity 8 of the molding die 1.

[0030] In the manufacturing method of the electronic control device 100 described above, since the molding mold 1 is a flexible sheet-like material, the structure of the molding mold 1 can be simplified, and the electronic control device 100 can be easily released from the molding mold 1. Furthermore, since the molding mold 1 is formed as a single unit, the electronic control device 100 can be easily released from the molding mold 1.

[0031] Furthermore, in the electronic control device 100, by providing an overhang 32 on the molding die 1, the outer edge portion of the upper end 200a of the potting resin body 200 can be recessed, as shown in Figure 5, thereby suppressing cracking or chipping of the edge portion of the upper end 200a of the potting resin body 200. Also, by providing an overhang 32 along the opening 9, the outer edge portion of the upper end 200a of the potting resin body 200 along the opening 9 can be recessed.

[0032] According to the molding die 1 of this embodiment, since it has a cavity 8 for molding the electronic control device 100 and a protruding portion 32 that faces the cavity 8 and faces the bottom portion 2 of the cavity 8, it is possible to suppress cracking or chipping of the edge portion of the upper end portion 200a of the electronic control device 100.

[0033] In this embodiment, the electronic control device 100 was molded using the molding mold 1, but the invention is not limited to this, and molded products other than the electronic control device 100 can also be molded using the molding mold 1.

[0034] (Embodiment 2) <Configuration of the molding die> The configuration of the molding die 51 according to the second embodiment of the present invention will be described in detail with reference to Figure 6.

[0035] In Figure 6, parts that have the same configuration as those in Figure 3 are denoted by the same reference numerals, and their descriptions are omitted. Also, in the configuration of the molding die 51 according to this embodiment, parts that have the same configuration as those in the molding die 1 are described using the same reference numerals, and their illustration and detailed description are omitted.

[0036] The molding die 51 is integrally formed from a flexible and breakable sheet-like or plate-like member such as a synthetic resin material, and has a bottom portion 2, a right side wall portion 3, a left side wall portion 4, an inclined wall portion 5, a front wall portion 6, a rear wall portion 7, a cavity 8, an opening 9, a protrusion 10, a row of recesses 31, and an overhang 33.

[0037] The protruding portion 33, which serves as the first wall, is provided along the opening 9. The protruding portion 33 extends into the cavity 8 from the upper ends of the right wall portion 3, the left wall portion 4, the front wall portion 6, and the rear wall portion 7, and faces the cavity 8. The protruding portion 33 is inclined toward the inside of the cavity 8, away from the bottom 2. The protruding portion 33 is inclined toward the right wall portion 3, the left wall portion 4, the front wall portion 6, and the rear wall portion 7, which serve as the second wall portion. Each of the right wall portion 3, the left wall portion 4, the front wall portion 6, and the rear wall portion 7 is connected to the bottom 2 side relative to the protruding portion 33.

[0038] The molding die 51 having the above configuration is a container-shaped member into which molten potting resin material is injected from the opening 9 into the cavity 8, and which can accommodate the potting resin material inside the cavity 8. It is used when manufacturing the electronic control device 100.

[0039] <Method for Manufacturing an Electronic Control Device> A method for manufacturing an electronic control device 100 using a molding die 51 according to a second embodiment of the present invention will be described in detail with reference to Figures 6 and 7.

[0040] After positioning the device body C in a predetermined location within the cavity 8 of the molding die 51, molten potting resin material is supplied from the opening 9 into the gaps between the device body C and each of the bottom 2, right side wall 3, left side wall 4, inclined wall 5, front wall 6, and rear wall 7, until the protruding portion 33 is submerged in the molten potting resin material, and then filled by gravity. Here, the position where the protruding portion 33 is submerged in the molten potting resin material is above the lower end of the protruding portion 33. As a result, the entire circuit board 101, electronic components 102a, 102b, 102c, and 102d are submerged in the potting resin material, while only a portion of the connector 103 on the circuit board 101 side is submerged in the potting resin material.

[0041] At this time, the molten potting resin material rises as it fills the cavity 8 and reaches the protruding portion 33, and then moves along the protruding portion 33 to the inside of the cavity 8. The potting resin material that has moved to the inside of the cavity 8 is held in place at the end of the protruding portion 33 in the protruding direction by surface tension. As the potting resin material that has filled the cavity 8 in this way hardens, an edge portion E2 is formed on the inside of the potting resin body 200.

[0042] Furthermore, the manufacturing methods of the electronic control device 100 using the molding die 51 according to this embodiment, other than those described above, are the same as the manufacturing methods of the electronic control device 100 using the molding die 1, so their explanation will be omitted.

[0043] In the electronic control device 100 manufactured using the molding die 51 according to the present embodiment, by providing the overhanging portion 33 along the opening 9, the edge portion outside the upper end portion 200a along the opening 9 of the potting resin body 200 can be recessed. Further, the overhanging portion 33 is inclined with respect to each of the right side wall portion 3, the left side wall portion 4, the front wall portion 6, and the rear wall portion 7, and the overhanging portion 33 is inclined in a direction away from the bottom portion 2 toward the inside of the cavity 8, so that the angle α1 of the edge portion E1 and the angle α2 of the edge portion E2 on the upper end portion 200a side of the potting resin body 200 can be made obtuse angles. Therefore, it is possible to suppress the edge portion E1 and the edge portion E2 of the potting resin body 200 from cracking or chipping. Further, the overhanging portion 33 controls the direction of burr generation, and a burr can be formed on the inner edge portion E2 of the potting resin body 200. Further, by suppressing the formation of burrs protruding outside the potting resin body 200, the process for removing burrs from the electronic control device 100 can be eliminated. Further, by controlling the direction of burr generation by the overhanging portion 33, it is possible to make it difficult for the burr formed on the edge portion E② to become a thin needle shape.

[0044] According to the molding die 51 according to the present embodiment, since the overhanging portion 33 is inclined in a direction away from the bottom portion 2 toward the inside of the cavity 8, in addition to the effects of the first embodiment described above, it is possible to suppress the formation of burrs protruding outside the potting resin body 200.

[0045] Further, in the present embodiment, the electronic control device 100 is molded using the molding die 51. However, the present invention is not limited to this, and molded products other than the electronic control device 100 can be molded using the molding die 51.

[0046] (Embodiment 3) <Configuration of molding die> The configuration of the molding die 61 according to the third embodiment of the present invention will be described in detail with reference to FIGS. 8 and 9.

[0047] In FIG. 8, the parts having the same configuration as those in FIG. 3 are denoted by the same reference numerals, and the description thereof is omitted. Further, in the configuration of the molding die 61 according to the present embodiment, the parts having the same configuration as those in the molding die 1 are described using the same reference numerals, and the illustration and description thereof are omitted.

[0048] The molding die 61 is integrally formed of a flexible and breakable sheet-like or plate-like member such as a synthetic resin material, and has a bottom portion 2, an inclined wall portion 5, a front wall portion 6, a rear wall portion 7, a cavity 8, an opening portion 9, a convex portion 10, a concave portion row 31, an overhanging portion 34, a right side wall portion 62, and a left side wall portion 63.

[0049] The bottom portion 2 connects the lower end portion of the right side wall portion 62, the lower end portion of the inclined wall portion 5, the lower end portion of the front wall portion 6, and the lower end portion of the rear wall portion 7.

[0050] The right side wall portion 62 connects the front end portion of the bottom portion 2, the right end portion of the front wall portion 6, and the right end portion of the rear wall portion 7. The right side wall portion 62 is inclined so as to approach the left side wall portion 63 downward.

[0051] The left side wall portion 63 connects the upper end portion of the inclined wall portion 5, the left end portion of the front wall portion 6, and the left end portion of the rear wall portion 7. The left side wall portion 63 is inclined so as to approach the right side wall portion 62 downward.

[0052] The inclined wall portion 5 connects the left end portion of the bottom portion 2, the lower end portion of the left side wall portion 63, the left end portion of the front wall portion 6, and the left end portion of the rear wall portion 7. The inclined wall portion 5 is inclined in a direction approaching the right side wall portion 62 downward from the lower end portion of the left side wall portion 63.

[0053] The front wall portion 6 connects the front end portion of the right side wall portion 62, the front end portion of the left side wall portion 63, and the front end portion of the bottom portion 2.

[0054] The rear wall portion 7 connects the rear end portion of the right side wall portion 62, the rear end portion of the left side wall portion 63, and the rear end portion of the bottom portion 2.

[0055] The cavity 8 is a space surrounded by the bottom portion 2, the right side wall portion 62, the left side wall portion 63, the inclined wall portion 5, the front wall portion 6, and the rear wall portion 7.

[0056] The protrusion 10 extends to the right from the upper end of the right side wall 62, increasing the thickness of the right side wall 62. The protrusion 10 is provided from the viewpoint of improving the strength of the right side wall 62 and improving the grip of the worker.

[0057] The row of recesses 31 is formed continuously from the lower end of the right side wall portion 62, through the upper end of the right side wall portion 62, to the right end of the protrusion 10.

[0058] The protruding portion 34, which serves as the first wall, is provided along the opening 9. The protruding portion 34 extends into the cavity 8 from the upper ends of the right wall portion 62, the left wall portion 63, the front wall portion 6, and the rear wall portion 7, and faces the cavity 8. The protruding portion 34 is inclined toward the inside of the cavity 8, away from the bottom portion 2. The protruding portion 34 is inclined toward the right wall portion 62, the left wall portion 63, the front wall portion 6, and the rear wall portion 7, which serve as the second wall portion. The right wall portion 62, the left wall portion 63, the front wall portion 6, and the rear wall portion 7 are connected to the bottom portion 2 side relative to the protruding portion 34.

[0059] <Method for Manufacturing an Electronic Control Device> A method for manufacturing an electronic control device 100 using a molding die 61 according to the third embodiment of the present invention will be described in detail with reference to Figures 8 and 9.

[0060] After positioning the device body C in a predetermined location within the cavity 8 of the molding die 61, molten potting resin material is supplied from the opening 9 into the gaps between the device body C and each of the bottom 2, right side wall 62, left side wall 63, inclined wall 5, front wall 6, and rear wall 7, until the protruding portion 34 is submerged in the molten potting resin material, and then filled by gravity. Here, the position where the protruding portion 34 is submerged in the molten potting resin material is above the lower end of the protruding portion 34. As a result, the entire circuit board 101, electronic components 102a, 102b, 102c, and 102d are submerged in the potting resin material, while only a portion of the connector 103 on the circuit board 101 side is submerged in the potting resin material.

[0061] At this time, the molten potting resin rises as it fills the cavity 8 and reaches the protruding portion 34, and then moves along the protruding portion 34 to the inside of the cavity 8. The potting resin that has moved to the inside of the cavity 8 is held in place at the end of the protruding portion 34 in the protruding direction by surface tension. As the potting resin that has filled the cavity 8 in this way hardens, an edge portion E4 is formed on the inside of the potting resin body 200.

[0062] Furthermore, the manufacturing methods of the electronic control device 100 using the molding die 61 according to this embodiment, other than those described above, are the same as the manufacturing methods of the electronic control device 100 using the molding die 1, so their descriptions will be omitted.

[0063] In the electronic control device 100 manufactured using the molding die 61 according to this embodiment, by providing a protruding portion 33 along the opening 9, the outer edge portion of the upper end 200a of the potting resin body 200 along the opening 9 can be recessed. Furthermore, by inclining the protruding portion 34 with respect to each of the right side wall portion 62, the left side wall portion 63, the front wall portion 6, and the rear wall portion 7, and by inclining the protruding portion 34 toward the inside of the cavity 8 away from the bottom portion 2, the angle α3 of the edge portion E3 and the angle α4 of the edge portion E4 on the upper end 200a side of the potting resin body 200 can be made obtuse, thereby suppressing cracking or chipping of the edge portions E3 and E4 of the potting resin body 200. In addition, the direction of burr generation can be controlled by the protruding portion 34, allowing burrs to be formed on the inner edge portion E4 of the potting resin body 200. Furthermore, by suppressing the formation of burrs that protrude outward from the potting resin body 200, the process of removing burrs from the electronic control device 100 can be eliminated. Furthermore, by controlling the direction of burr generation with the protruding portion 34, it is possible to prevent the burrs formed on the edge portion E4 from becoming thin and needle-shaped. In particular, in the electronic control device 100 molded by the molding die 61, the sharp-angled edge portion of the upper end portion 200a of the potting resin body 200 that would be formed if the protruding portion 34 were not provided can be eliminated, thus reliably preventing the sharp-angled edge portion of the potting resin body 200 from cracking or chipping.

[0064] Furthermore, although the electronic control device 100 was molded using the molding die 61 in this embodiment, the invention is not limited to this, and molded products other than the electronic control device 100 can be molded using the molding die 61.

[0065] The present invention is not limited to the above-described embodiments in terms of the type, shape, arrangement, number, etc. of the components, and it is of course possible to modify them as appropriate without departing from the spirit of the invention, such as by appropriately substituting the components with those that produce equivalent effects.

[0066] As described above, the present invention can suppress cracking or chipping of the edge portion at the upper end of a molded product, and due to its general-purpose and universal nature, it is expected to be widely applicable to molds for obtaining molded products such as electronic control devices and to methods for manufacturing molded products.

[0067] 1... Molding mold 2... Bottom 3... Right side wall 4... Left side wall 5... Slanted wall 6... Front wall 7... Rear wall 8... Cavity 9... Opening 10... Convex part 31... Concave row 32... Overhang 33... Overhang 34... Overhang 51... Molding die 61... Molding die 62... Right side wall 63... Left side wall 100...Electronic control device 200...Potting resin body

Claims

1. A molding die used to obtain a molded product, characterized by having a cavity for molding the molded product, and a first wall portion facing the cavity and facing the bottom of the cavity.

2. The molding die according to claim 1, characterized in that it has a second wall portion that faces the cavity and is connected to the bottom side with respect to the first wall portion, the first wall portion is inclined with respect to the second wall portion and is inclined toward the inside of the cavity toward away from the bottom portion.

3. The molding die according to claim 1, characterized in that it has an opening that communicates the cavity with the outside, and the first wall portion is provided along the opening.

4. The molding die according to claim 1, characterized in that the molding die is formed from a flexible sheet-like member.

5. The molding die according to any one of claims 1 to 4, characterized in that the molding die is formed integrally.

6. A method for manufacturing a molded product obtained using a molding die, comprising: a first step of supplying a liquid material to a cavity of the molding die for molding the molded product; and a second step of curing the liquid material supplied to the cavity in the first step, wherein the molding die has a wall portion facing the cavity and facing the bottom of the cavity, and the first step is to supply the liquid material to a position where the wall portion is immersed in the liquid material.

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