JP2007331246A - Method and apparatus for molding of insert molding - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and an apparatus for molding an insert molding which can avoid occurrence of holes exposing the insert member of an insert molding, ensure waterproof performance of the insert molding with a mold of a simple structure and thereby improve the quality. <P>SOLUTION: The molding method comprises charging an insert member 40 in a mold 11 for injection molding, injecting a molding material in the charging direction of the insert member 40 from one or more gates 19 arranged (1) on the center-of-gravity line C which passes through the center of gravity of the insert member 40 and is in parallel with the charging direction of the insert member 40 or (2) at positions symmetrical with respect to the center-of-gravity line C and fixing the insert member 40 to the mold 11 for injection molding through the injection pressure of the molding material. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an insert molding method and an insert molding apparatus for molding an insert molded product in which an insert member is embedded in a molding material.

  2. Description of the Related Art Conventionally, a method for molding an insert molded product is known in which insert molding is performed while holding an insert member disposed in a cavity of a mold with a fixing pin (see, for example, Patent Document 1).

  As shown in FIG. 5, the insert-molded product disclosed in Patent Document 1 is a connector 101 in which a terminal fitting 103 is embedded in a resin-made housing 102. This connector 101 performs the steps of primary molding and secondary molding. Formed through.

  First, as shown in FIG. 6, the terminal fitting 103 is disposed in the cavity 106 defined by the primary molding dies 104 and 105, and is attached to the numerous pins 107 and 108 provided on the dies 104 and 105. In this state, the cavity 106 is filled with a molten resin, which is a molding material, and a primary molded product 109 shown in FIG. 7 is molded.

By supporting the terminal fitting 103 with a large number of pins 107 and 108, problems such as the deviation of the terminal fitting 103 due to the pressure of the injected molten resin and the uneven thickness of the resin due to this are solved. Yes.
Japanese Patent Laid-Open No. 11-185926

  Here, in the primary molded product 109 of Patent Document 1, the hole 110 remains on the trace where the pins 107 and 108 were located when the molten resin was filled. Therefore, a portion exposed through these holes 110 is formed in a portion of the terminal fitting 103 that should be covered with resin and waterproofed.

  With respect to this problem, in Patent Document 1, the connector 101 is molded in two stages, and the primary molded product 109 is disposed in the cavity of a secondary molding die that finally molds the outer shape of the connector 101. Thus, the small hole 110 is closed when the molten resin is filled and the outer shape of the connector 101 is molded. However, according to this, different molds are required for the primary molding and the secondary molding, and there is a risk that the mold facilities will increase and the manufacturing cost will increase.

  The present invention has been made in view of such circumstances, avoids the formation of a hole that exposes the insert member in the insert molded product, and ensures the waterproof performance of the insert molded product with a simple mold structure. An object of the present invention is to provide a molding method and a molding apparatus for an insert molded product that can improve quality.

  The above object is achieved by the following method (1) for molding an insert-molded product, and (2) to (3) the apparatus for molding an insert-molded product.

(1) Insert the insert member into the injection mold,
A molding material is injected in the loading direction of the insert member from one or two or more gates arranged on a centroid line passing through the centroid of the insert member and parallel to the loading direction of the insert member or symmetrically with respect to the centroid line. And
A method for molding an insert-molded product, wherein the insert member is fixed to the molding die by an injection pressure of the molding material.

(2) provided with an injection mold in which an insert member is loaded;
The injection mold is provided with one or more gates arranged on a center line passing through the center of gravity of the insert member and parallel to the loading direction of the insert member, or symmetrically with respect to the center of gravity line. Has been
A molding apparatus for an insert molded product, wherein a molding material is injected from the gate in a loading direction of the insert member.

  (3) The insert molding product forming apparatus according to (2), wherein the gate is a pin gate.

  According to the method for molding an insert-molded product according to (1) above and the molding apparatus for the insert-molded product according to (2) above, the gate passes on the center of gravity line passing through the center of gravity of the insert member and parallel to the loading direction of the insert member. Alternatively, they are arranged at symmetrical positions with respect to the center of gravity line. Therefore, when the molding material is injected from the gate in the loading direction of the insert member, the injection pressure of the molding material mainly acts as a force for urging the insert member to the mold without generating a moment in the direction in which the insert member tilts. To do. As a result, the insert member is firmly fixed to the mold, and since the molding material is injected evenly to the edge of the thickness of the insert member, it is difficult to apply a force in the bending direction of the insert member, preventing deviation. Therefore, fixing with a pin in the prior art is not required. Therefore, no hole or weld for exposing the insert member is formed in the insert molded product, and the waterproof performance of the insert molded product can be ensured to improve the quality. Further, it is not necessary to provide a pin or a pin driving mechanism in the molding apparatus, the molding apparatus can be simplified, and the manufacturing cost of the insert molded product can be reduced.

  According to the molding apparatus for insert-molded products described in (3) above, the gate is a pin gate, and the molding material spreads radially from the gate and is filled. Therefore, it is difficult for the injection pressure acting on the insert member to be biased in the direction intersecting the loading direction of the insert member, and the bias of the insert member can be more reliably prevented. In addition, the runner connected to the gate and the insert-molded product can be easily separated, the broken portion in the gate can be minimized, and post-processing such as deburring can be eliminated.

  ADVANTAGE OF THE INVENTION According to this invention, it can avoid forming the hole which exposes an insert member in an insert molded product, and can ensure the waterproof performance of an insert molded product with a simple die structure, and can aim at quality improvement.

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.
1 is a cross-sectional view showing an embodiment of a molding apparatus for insert-molded products according to the present invention, FIG. 2 is a cross-sectional view taken along the line II-II in FIG. 1, and FIG. 3 is a flow of molding material of the molding apparatus shown in FIG. FIG. 4 is a sectional view of the molding apparatus shown in FIG. 1 in a state where the molding is completed.

  As shown in FIGS. 1 and 2, a molding apparatus 10 that performs an insert molding method according to the present invention includes an injection mold in which a connector terminal 40 that is an insert member is loaded, and this injection mold. Is composed of an inner mold 11 and an outer mold 12 which can be divided, and a cavity 13 filled with a molding material is defined between opposing surfaces of the inner mold 11 and the outer mold 12.

  A plurality of terminal insertion holes 14 for attaching the connector terminals 40 to the inner mold 11 are provided in the upper wall portion 11a of the inner mold 11 having the facing surface facing upward. The connector terminal 40 is a flat-plate terminal, and has a plurality of electrical connection portions 41 arranged in a comb shape. The electrical connection portions 41 of the connector terminal 40 are inserted into the terminal insertion holes 14 respectively. The connector terminal 40 is loaded into the inner mold 11 in a vertically downward direction so that the electrical connection portion 41 is inserted into the terminal insertion hole 14.

  A plurality of terminal support portions 15 that support the protruding ends of the electrical connection portions 41 that are inserted into the terminal insertion holes 14 and have entered the inside of the inner die 11 are provided inside the inner die 11. The terminal support portion 15 is disposed vertically below the terminal insertion hole 14, and the electrical connection portion 41 abuts on the terminal support portion 15 at the tip thereof and is supported by the terminal support portion 15.

  The outer mold 12 is provided with a gate 19 that opens to the cavity 13 and a torch receiver 18 that communicates with the gate 19 via a flow path 20. An injection torch 17 for injecting a molding material is attached to the torch receiver 18. The injection torch 17 is supplied with a molding material melted from a mixer (not shown) which is a stirring / preheating / injection device, and the injection molding material injected from the injection torch 17 is injected from the gate 19 into the cavity 13 through the flow path 20. Is done.

  Here, the line C shown in FIG. 1 and FIG. 2 is a line that passes through the center of the plate-like connector terminal 40 in the thickness direction, and the connector terminal 40 is formed symmetrically with respect to the line C. That is, the line C is a centroid line passing through the centroid of the connector terminal 40. The barycentric line C extends in parallel with the comb-like electrical connection portion 41 of the connector terminal 40, that is, parallel to the loading direction of the connector terminal 40 into the inner mold 11.

  The gate 19 is provided on the surface facing the upper wall portion 11a of the inner mold 11 provided with the terminal insertion hole 14, and passes through the center of gravity of the connector terminal 40 and the loading direction of the connector terminal 40 to the inner mold 11 It is arranged on the center of gravity line C parallel to the. Then, the molding material is injected from the gate 19 toward the vertically downward direction, which is the loading direction of the connector terminal 40 to the inner mold 11.

  The gate 19 is an orifice-shaped so-called pin gate, and the injected molding material MR is filled in the cavity 13 while spreading radially as shown in FIG. At this time, the molding material MR that has flowed into the cavity 13 hits the upper end surface of the connector terminal 40 on both sides of the connector terminal 40 in the plate thickness direction because the gate 19 is disposed on the center of gravity line C of the connector terminal 40. Divided into approximately the same amount. Therefore, the pressure acting on the connector terminal 40 from the molding material MR becomes substantially uniform in the thickness direction of the connector, and deviation such as tilting of the connector terminal 40 in the thickness direction is prevented.

  The connector terminal 40 receives the pressure of the molding material MR injected in the loading direction of the connector terminal 40 into the inner mold 11 at the upper end surface orthogonal to the loading direction, and is thus biased toward the inner mold 11. . Thereby, the connector terminal 40 is firmly fixed to the inner mold 11.

  After the cavity 13 is filled with the molding material MR and the molding material MR is solidified as shown in FIG. 4 through the cooling / drying process, the outer mold 12 is raised, and the runner 21 formed in the flow path 20 is connected to the gate 19. Is disconnected. And the ejector pin 16 provided in the inner mold | type 11 raises, and the connector 30 which is an insert molded product holding the connector terminal 40 is isolate | separated from the inner mold | type 11. FIG.

  As described above, according to the insert molding method and molding apparatus 10 of this embodiment, the gate 19 passes through the center of gravity of the connector terminal 40 and is on the center of gravity line C parallel to the loading direction of the connector terminal 40 or the center of gravity. Arranged symmetrically with respect to the line. Therefore, when the molding material is injected from the gate 19 in the loading direction of the connector terminal 40, the injection pressure of the molding material mainly applies the connector terminal 40 to the inner mold 11 without generating a moment in the direction in which the connector terminal 40 tilts. Acts as an energizing force. As a result, the connector terminal 40 is firmly fixed to the inner mold 11, and the molding material is uniformly injected onto the edge of the plate thickness of the connector terminal 40, so that it is difficult to apply force in the direction in which the connector terminal 40 bends. It is not necessary to fix with a pin in the prior art for preventing deviation. Therefore, no hole or weld that exposes the connector terminal 40 in the connector 30 is formed, and the waterproof performance of the connector 30 can be secured to improve the quality. Moreover, it is not necessary to provide the molding apparatus 10 with a pin or a pin driving mechanism, the molding apparatus 10 can be simplified, and the manufacturing cost of the connector 30 can be reduced.

  Further, according to the molding apparatus 10, the gate 19 is a pin gate, and the molding material spreads radially from the gate 19 and is filled. Therefore, it is difficult for the injection pressure acting on the connector terminal 40 to be biased in the direction intersecting the loading direction of the connector terminal 40, and the bias of the connector terminal 40 can be prevented more reliably. In addition, the runner 21 and the connector 30 connected to the gate 19 can be easily separated, the broken portion in the gate 19 can be minimized, and post-processing such as deburring can be made unnecessary.

  In addition, this invention is not limited to embodiment mentioned above, A deformation | transformation, improvement, etc. are possible suitably. In addition, the material, shape, dimension, numerical value, form, number, arrangement location, and the like of each component in the above-described embodiment are arbitrary and are not limited as long as the present invention can be achieved.

  For example, in the above-described embodiment, the gate 19 is disposed on the center line C passing through the center of gravity of the connector terminal 40 and parallel to the loading direction of the connector terminal 40. Even if the gate 19 is arranged, the same effect can be obtained.

It is sectional drawing which shows one Embodiment of the shaping | molding apparatus of the insert molded product which concerns on this invention. It is the II-II arrow sectional drawing in FIG. It is sectional drawing explaining the flow of the molding material of the molding apparatus shown in FIG. It is sectional drawing of the shaping | molding apparatus shown in FIG. 1 in the state which shaping | molding completed. It is a perspective view of the insert molded product shape | molded by the conventional insert molding method. It is sectional drawing of the metal mold | die for shape | molding the primary molded product which comprises the insert molded product of FIG. It is a perspective view of the primary molded product shape | molded with the metal mold | die of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Molding device 11 Inner mold 12 Outer mold 13 Cavity 19 Gate 30 Connector (insert molding product)
40 Connector terminal (insert member)
C Center of gravity line MR Molding material

Claims (3)

Insert the insert member into the injection mold,
A molding material is injected in the loading direction of the insert member from one or two or more gates arranged on a centroid line passing through the centroid of the insert member and parallel to the loading direction of the insert member or symmetrically with respect to the centroid line. And
A method for molding an insert-molded product, wherein the insert member is fixed to the injection-molding die by an injection pressure of the molding material. It has an injection mold in which an insert member is loaded,
The injection mold is provided with one or more gates arranged on a center line passing through the center of gravity of the insert member and parallel to the loading direction of the insert member, or symmetrically with respect to the center of gravity line. Has been
A molding apparatus for an insert molded product, wherein a molding material is injected from the gate in a loading direction of the insert member.   The apparatus for molding an insert-molded product according to claim 2, wherein the gate is a pin gate.

Images