JP6407041B2 - Resin leakage prevention packing - Google Patents

Description

  The present invention relates to a resin leakage prevention packing used when molding an insert member in an externally protruding state in injection molding.

  In the injection molding of thermosetting resin such as epoxy resin, when inserting a component such as a capacitor unit and pulling out the terminal board of that component to the outside of the resin molded product, a resin leakage prevention packing is used to prevent resin leakage. To seal the drawer boundary.

  FIG. 8 is a perspective view showing a conventional rubber resin leakage prevention packing 60L (see the solid line portion). The packing 60L is integrated with a seat surface plate portion 61 on which a flat seat surface for setting an insert member 70 (refer to a chain line portion) such as a terminal plate is formed and a step having a predetermined height on both sides thereof. And thick outer end portions 62 and 62 connected to each other. The packing 60L is flat on the mold 80L in a state where the outer surfaces of the thick outer end portions 62, 62 are regulated by the side plate portions 82, 82 on both sides of the lower mold 80L (see the broken line portion). The main surface plate portion 81 is set.

  9 to 12 show how the insert member 70 is set to the pair of upper and lower resin leakage prevention packings 60U and 60L. In FIG. 9, the lower packing 60L to which the insert member 70 is set is set in the lower mold 80L, and the upper packing 60U is set in the upper mold 80U, apart from the lower mold 80L. It is. FIG. 10 illustrates a state in which a pair of upper and lower molds 80U and 80L are clamped from the state of FIG. In mold clamping, the lower mold 80L is a fixed side and the upper mold 80U is a sliding side. 11 (a) and 11 (b), the change from the mold matching state to the mold clamping state is shown enlarged, and in FIGS. 12 (a) to 12 (c), the change is shown further enlarged. The packings 60U and 60L in the illustrated example have an elongated shape, and for convenience of illustration, a part of the intermediate portion is drawn together with the insert member 70 and the upper and lower molds 80U and 80L.

  The setting of the packing 60U for the upper mold 80U is the same as the setting of the packing 60L for the lower mold 80L. In this case, the upper and lower relationships are symmetric. The insert member 70 is inserted into a cavity 83 formed inside the upper and lower molds 80U and 80L in a clamped state, and a part of the insert member 70 protrudes outside the mold. Then, a thermosetting epoxy resin is injected into the cavity 83 to produce a resin molded product. At this time, a part of the insert member 70 is embedded in the resin molded product, and the remaining part projects outside the resin molded product. Therefore, there is a possibility that a gap is formed around the insert member 70 inside and outside the cavity 83, and the molten resin may leak out from the gap. The role of the packings 60U and 60L is to avoid such leakage of the molten resin. That is, as described above, the upper and lower packings 60U and 60L are interposed between the upper and lower molds 80U and 80L and the insert member 70 projecting to the outside, thereby preventing resin leakage from the gap.

Japanese Patent No. 4628125

  However, manufacturing tolerances are inevitable in the component dimensions, and it is common that a minute gap is generated at the boundary between the resin leakage prevention packing and the insert member when the mold is clamped. Therefore, for example, when injection molding is performed at a high pressure using a low viscosity molten resin such as a liquid epoxy resin, the resin may leak from the minute gap. To avoid this situation, one of the following measures is required.

  (1) In order to make the gap so small that the resin does not leak out, parts are manufactured with very small tolerances.

  (2) A gap is not generated by absorbing the component variation with the packing.

  The measure (1) can be implemented by selecting parts. In actual results, resin leakage occurred in a gap of 0.2 mm, so the tolerance of the terminal board and packing needs to be ± 0.05 mm or less. However, the parts cost and the sorting / inspection work cost are very heavy, and the solution is not practical.

  Therefore, for the purpose of countermeasure (2) above, the structure described with reference to FIGS. 8 to 12 is employed. In that case, when the mold is clamped, the upper and lower packings 60U and 60L are elastically deformed by the applied pressure from the upper and lower molds 80U and 80L so as to close the gap with the outer surface of the insert member 70 as much as possible. I have to. That is, the gap seal with the insert member 70 is performed by giving the upper and lower packings 60U and 60L a crushing margin due to elastic deformation. The idea of this method is that the packings 60U and 60L are elastically deformed by the amount of crushing when the mold is clamped, and the gap with the terminal board is filled.

  In FIG. 12, the upper and lower packings 60U and 60L and the insert member 70 are shown in an enlarged manner, and the upper and lower molds 80U and 80L are not shown. FIG. 12 (a) shows the initial stage of mold clamping. The thick outer end 62 of the upper packing 60U is separated from the thick outer end 62 of the lower packing 60L, and the seat plate of the upper packing 60U. The part 61 is separated from the insert member 70. FIG. 12B shows a state where the mold clamping is further advanced, immediately after the thick outer end 62 of the upper packing 60U comes into contact with the thick outer end 62 of the lower packing 60L. FIG. 12B to FIG. 12C show a state in which the mold clamping is further advanced while elastically deforming the upper and lower packings 60U and 60L. FIG. 12 (c) shows the final stage of mold clamping, and the inner surfaces of the thick outer end portions 62, 62 are deformed due to elastic deformation corresponding to the crushing amount of the thick outer end portions 62, 62 of the packings 60U, 60L. It approaches the end surface of the insert member 70 in the horizontal direction, and the gap 90 between the two is narrowed compared to FIG. However, with such a measure, the amount of elastic deformation in the horizontal direction of the thick outer end portions 62, 62 is very small, and it is difficult to reliably fill the gap 90 on the end surface of the insert member 70. The resin leakage prevention performance must be low.

As another countermeasure, it is conceivable to use rubber having a sufficiently low hardness (soft) as a constituent material of the packings 60U and 60L. However, if you use a sufficiently soft packing,
[1] As the weight of the insert member (for example, a capacitor) increases, the amount of deformation of the packing becomes excessively large, making it difficult to accurately carry the insert member at the intended position, leading to deterioration in position accuracy. End up.

  [2] The pressure pressed against the insert member decreases, and the sealing performance deteriorates.

[3] As a result of the soft packing being deformed by being pressed by the pressure of the molten resin, a gap is formed, there is a risk of causing resin leakage.
Such a problem occurs.

  The present invention was created in view of such circumstances, and even when a low-viscosity molten resin is used, the gap between the end faces of the insert member is ensured while ensuring the proper positional accuracy of the insert member to be carried. The purpose of this is to improve the sealing performance against resin and reliably prevent resin leakage.

  The present invention solves the above problems by taking the following measures.

The resin leakage prevention packing according to the present invention is
Seals the opening facing the mating surface of a pair of molds to be clamped, and between the outer side surface of the insert member and the inner side surface of the opening that are arranged through the opening and inside and outside the cavity of the mold. Intervening in,
A pair of thick outer end portions that are integrally connected in a state of providing a step of a predetermined height on both sides of the seat surface plate portion and position-control the end surface of the insert member. And
The step forming portion from the seat surface of the seat plate portion to the main surface of the thick outer end contacts the inclined contact portion in a posture inclined with respect to the end surface corner of the insert member, and the inclined contact portion. A seal reinforcing ridge that continuously swells on the opposite side of the seat surface with respect to the main surface of the thick outer end,
When the insert member is moved closer to the seat plate portion by clamping the mold from a state in which the end surface corner portion of the insert member is in contact with the inclined contact portion, the insert member is pressed by the end surface corner portion of the insert member. Further, the inclined contact portion is elastically deformed, and accordingly, the seal reinforcing protrusion is pressed and elastically deformed so that the step forming portion is in close contact with the end surface of the insert member. It is characterized by being.

  The resin leakage prevention packing is interposed between the insert member disposed over the inside and outside of the mold cavity and the mold opening through which the insert member passes, and seals (seals) the gap between the insert member and the mold opening. Stop). In the pair of molds that form the cavity by mold clamping, an opening for inserting the insert member over the inside and outside of the cavity is formed on the mold mating surfaces of both molds. One of the resin leakage prevention packings may be used alone, or two may be used as a set. The resin leakage prevention packing is externally fitted to the insert member and fitted inside the mold opening, that is, interposed between the outer side surface of the insert member and the inner side surface of the opening. The opening facing the mating surfaces of the pair of molds in a state is sealed.

  The resin leakage prevention packing has a seat plate portion for setting the main surface portion of the insert member and thick outer end portions on both sides thereof. The thick outer edges on both sides are integrally connected to the seat plate with a predetermined height difference from the seat plate, and the position of the end surface of the insert member set on the seat plate is restricted. To do. In the present invention, in particular, the following measures are taken for the shape of the step forming portion from the seat surface of the seat plate portion to the main surface of the thick outer end. That is, the step forming portion includes an inclined contact portion that comes into contact with the end surface corner portion of the insert member at the time of mold clamping, and a seat plate on the main surface of the thick outer end portion continuously from the inclined contact portion. And a seal reinforcing ridge that swells on the opposite side of the portion. As a result, when the mold member is clamped, when the insert member further presses the inclined contact portion from the state where the end face corner portion of the insert member contacts the inclined contact portion of the resin leakage prevention packing, the pressed inclined contact portion is elastically deformed. To do. Along with this, the seal reinforcing ridges of the packing are pressed and elastically deformed. Then, the step forming portion (inclined contact portion / seal reinforcing protrusion) is elastically and strongly adhered to the end surface of the insert member as dragged by the elastic deformation of these two modes.

In addition, in said structure, the following aspects are preferable when making a level | step difference formation part closely_contact | adhere to the end surface of an insert member. First, about the shape of the said inclination contact part, the aspect formed in the concave curve shape and the aspect formed in the slope shape are preferable. In addition, it is preferable that the seal reinforcing protrusion is set to have a height that is about half of the step between the seat plate and the thick outer end. Moreover, it is preferable that the said seal | sticker reinforcement | strengthening protrusion part is made into a 1/2 circular arc shape. As for the material constituting the resin leakage prevention packing aspect entire thick outer ends of the front Symbol a pair the seat plate portion is made of rubber are preferred.

  The resin leakage prevention packing of the present invention may be used as a set of the two or may be used alone.

  When the recessed portion is formed on each of the mating surfaces of the pair of molds, two resin leakage prevention packings are used as one set. In this case, the aligned two recessed portions form an opening for inserting the insert member.

  If the mating surface of one mold has a recessed portion, but the mating surface of the other mold has no recessed portion and is a flat surface, Only one is used. The recessed portion of one mold is covered with the flat surface of the other mold to form an opening.

  The former configuration can be said as follows. That is, the opening is formed by aligning a pair of molds each having a recessed portion formed on the mating surface in an aligned state between the recessed portions, It is set and used for each of the recesses.

  Moreover, the latter structure can be said as follows. That is, the opening is formed by mold matching between a mold having a recessed portion formed on the mating surface and a mold having a flat mating surface, and is set only in the recessed portion of the one mold. To be used.

  According to the present invention, when the mold is clamped, due to the strong deformation of the inclined contact portion pressed by the insert member and the strong contact of the step forming portion with the end surface of the insert member due to the elastic deformation of the seal reinforcing ridge portion, Since the gap with the insert member due to tolerance is surely sealed, even if the molten resin has a low viscosity, resin leakage can be reliably prevented. Further, there is no need to extremely soften the constituent material of the resin leakage prevention packing, and the resin leakage prevention packing having an appropriate elastic strength can be constituted, so that the positional accuracy of the insert member to be carried can be ensured.

The perspective view which shows the resin leak prevention packing of the lower side in the Example of this invention in a partially cut state The perspective view which shows a pair of upper and lower resin leak prevention packing in the middle of mold clamping in the Example of this invention in a partially cut state The perspective view which shows a pair of upper and lower resin leak prevention packing in the state just before completion of mold clamping in the Example of this invention in a partially cut state Sectional drawing which shows the change from the state just before mold clamping completion of the resin leak prevention packing in the Example of this invention to mold clamping completion state The principal part expanded sectional view which shows the change from the state just before the mold clamping completion of the resin leak prevention packing in the Example of this invention to the mold clamping completion state The principal part expanded sectional view which shows the change from the state just before the mold clamping completion of the resin leak prevention packing in another Example of this invention to the mold clamping completion state Dimensional explanatory diagram of each example The perspective view which shows the lower side resin leakage prevention packing in a prior art example in a partly cut state A perspective view showing a pair of upper and lower resin leakage prevention packings in the middle of mold clamping in a conventional example in a partially cut state. The perspective view which shows a pair of upper and lower resin leak prevention packing in the state just before completion of mold clamping in a conventional example in a partially cut state Sectional drawing which shows the change from the state just before mold clamping completion of the resin leak prevention packing in a prior art example to mold clamping completion state The principal part expanded sectional view which shows the change from the state just before mold clamping completion of the resin leak prevention packing in a prior art example to mold clamping completion state

  Hereinafter, the embodiment of the resin leakage prevention packing of the present invention having the above configuration will be described in detail at the level of specific examples.

  FIG. 1 shows a lower resin leakage prevention packing 10L in the embodiment of the present invention. In this figure, a part of the central portion of the packing 10L is cut away so as to be shortened. FIG. 2 shows a pair of upper and lower resin leakage prevention packings 10U and 10L during mold clamping. FIG. 3 shows the upper and lower packings in a state immediately before completion of mold clamping. FIG. 4 shows a change from the state immediately before the mold clamping is completed to the mold clamping completed state. FIG. 5 shows a change from the state immediately before the mold clamping is completed to the mold clamping completed state.

  1 to 5, 10U is an upper resin leakage prevention packing (hereinafter simply referred to as upper packing 10U), 10L is a lower resin leakage prevention packing (hereinafter simply referred to as lower packing 10L), and 11 is an upper and lower portion. 10 is a seat plate portion in each of the packings 10U and 10L, 12 is a thick outer end portion in each of the upper and lower packings 10U and 10L, 20 is an insert member such as a terminal plate in the capacitor unit, 30U is an upper mold, and 30L is a lower side , 31 is a main plate portion, 32 and 32 are side plate portions on both sides of the die, and 33 is a cavity. The upper and lower packings 10U and 10L have elongated shapes, and are drawn in a state in which the central portion is cut for convenience of drawing (see hatching). Moreover, the insert member 20 is drawn in a state in which the central portion is cut out (see filling).

  As shown in FIG. 1, the lower packing 10 </ b> L has a seat surface plate portion 11 on which a flat seat surface for setting the insert member 20 is formed, and steps of a predetermined height on both sides of the seat surface plate portion 11. It has a pair of thick outer end portions 12, 12 that are integrally connected in the provided state. The thick outer end portions 12, 12 on both sides have the same thickness. The lower packing 10L further includes a step forming portion 13 extending from the seating surface of each seating surface plate portion 11 to each thick outer end portion 12, as shown in detail in FIG. An inclined contact portion 13a that comes into contact with the end surface corner portion 21 of the insert member 20 at the time of tightening, and a seat plate portion with respect to the main surface (surface) of the thick outer end portion 12 continuously to the inclined contact portion 13a. 11 is provided with a seal reinforcing ridge 13b that swells on the opposite side to 11. In the present embodiment, the inclined contact portion 13a has a substantially concave curved shape, and the seal reinforcing ridge portion 13b has a protruding curved shape of almost a half arc. The contact portion 13a and the seal reinforcing ridge portion 13b are smoothly continuous. Further, the inclined contact portion 13a and the seat surface of the seat surface plate portion 11, the seal reinforcing protrusion 13b, and the main surfaces of the thick outer end portion 12 are smoothly continuous. The lower mold 30L is a fixed side, and the upper mold 30U is a sliding side. The height of the seal reinforcing protrusion 13b is set to about half of the step between the seat surface plate 11 and the thick outer end 12 (90% to 110% of the height of the half of the step).

  The above is a description of the lower packing 10L, but the structure / shape of the upper packing 10U is symmetrical to the structure / shape of the lower packing 10L, as shown in FIGS. . The relationship between the upper packing 10U and the insert member 20 is also the same. Both the upper and lower packings 10U and 10L are made of rubber. That is, each of the seat plate portions 11 and the thick outer end portions 12 and 12 on both sides integral with the seat plate portions 11 are made of synthetic rubber.

  The pair of upper and lower molds 30U and 30L are formed in a clamped state to form a cavity 33 therebetween. The capacitor unit to be molded by injection of molten resin into the cavity 33 is used as a power source in actual use. It has a terminal board to be connected. The outer resin of the capacitor unit is formed by curing the molten resin, and a terminal board is formed between the inner and outer surfaces of the outer resin. The terminal board protrudes from the opening of the pair of upper and lower molds 30U and 30L. In this embodiment, this terminal board is used as the insert member 20.

Regarding the dimensional relationship, as shown in FIG. 7 (a), when the step between the seat plate 11 and the thick outer end 12 is a and the thickness of the insert member 20 is t,
a × 2 ≧ t
And More specifically, if the level difference of one packing is a1, and the level difference of the other packing is a2,
a1 + a2 ≧ t
It is. The reason for this is to cause elastic deformation in the thickness direction of the upper and lower thick outer end portions 12 and 12 (see the change from FIG. 5A to FIG. 5D).

  In addition, a silicone rubber can be mentioned as a preferable material about the upper and lower packings 10U and 10L. The preferred hardness is 70 to 90 degrees. By setting the hardness in this way, the mold is clamped while the end face corner portion 21 of the insert member 20 is in contact with the inclined contact portion 13a, so that the insert member 20 can be positioned by a self-alignment action.

  Next, the operation at the time of clamping the pair of upper and lower molds 30U and 30L will be described.

  First, as shown in FIGS. 4A and 3, the lower packing 10 </ b> L on which the insert member 20 is set is set on the lower mold 30 </ b> L. In this state, the insert member 20 is in a posture parallel to the lower packing 10L, and the lower end corners 21 and 21 on both sides of the insert member 20 are in contact with the middle portions of the inclined contact portions 13a and 13a. A minute gap 40 is opened between the insert member 20 and the seat surface plate portion 11. In a state immediately before clamping, the upper mold 30U with the upper packing 10U set is positioned above the insert member 20.

  Next, as shown in FIG. 4B, mold clamping is performed. That is, the upper mold 30U and the upper packing 10U are moved downward to cover the lower mold 30L and the insert member 20 on the lower packing 10L. In this state, the seal reinforcing protrusions 13b and 13b on both sides of the upper packing 10U are in contact with or close to the seal reinforcing protrusions 13b and 13b on both sides of the lower packing 10L. The upper and lower molds 30U and 30L are still separated from each other. That is, the lower ends of the side plate portions 32, 32 on both sides of the upper mold 30U are spaced upward from the upper ends of the side plate portions 32, 32 on both sides of the lower mold 30L. An enlarged view of the main part of FIG. 4B is shown in FIG. There is a gap 40 between the lower surface of the insert member 20 and the seat surface plate portion 11 of the lower packing 10L. Similarly, a gap 40 is also formed between the upper surface of the insert member 20 and the seat surface plate portion 11 of the upper packing 10U. There is. And the lower end surface corners 21 and 21 of the insert member 20 are in contact with the middle portions of the inclined contact portions 13a and 13a of the lower packing 10L, and the upper end surface corners 21 and 21 of the insert member 20 are the upper side. It contacts the middle part of the inclined contact portions 13a and 13a of the packing 10U (see FIG. 5A).

  The thickness of the thick outer end 12 in the packings 10U and 10L is greater than the height of the side plate 32 in the molds 30U and 30L. This is because when the mold is clamped until the side plate portions 32, 32 of the pair of upper and lower molds 30U, 30L are brought into contact with each other, elastic pressing deformation of the upper and lower thick outer end portions 12, 12 is brought about. .

  Next, the mold clamping is advanced by forcibly pushing down the upper mold 30U and the upper packing 10U from the state shown in FIGS. 4 (b) and 5 (a). The detailed progress state at this time is shown in FIGS. 5 (b), (c) and (d). FIG. 4C corresponds to FIG. That is, as shown in FIG. 5B, the upper mold 30U is moved closer to the lower mold 30L, and the seal reinforcing protrusions 13b and 13b that are in contact with each other at the top and bottom are pressed against each other. Then, it is deformed elastically together with the inclined contact portions 13a, 13a.

  Hereinafter, with reference to FIGS. 5B, 5 </ b> C, and 5 </ b> D, the step forming portion 13 (the inclined contact portion 13 a and the seal reinforcing ridge portion 13 b) in the vicinity of the left end portion of the insert member 20 is used. (The operation in the vicinity of the right end is the same as this.)

  From the state (FIG. 5A) where the lower end face corner 21 of the insert member 20 is in contact with the middle portion of the inclined contact portion 13a of the lower packing 10L, as shown in FIG. When the insert member 20 moves downward so as to narrow the gap 40 with the seating surface plate portion 11, the end surface corner portion 21 presses the middle portion of the inclined contact portion 13a downward. Then, the slanting contact portion 13a is elastically deformed so as to wrap around by the action of a lever having a contact point with the end face corner portion 21 as a fulcrum. The elastic deformation is a deformation in the direction approaching the end face of the insert member 20 (clockwise around the fulcrum) (counterclockwise at the right end). Simultaneously with the elastic deformation of the inclined contact portion 13 a, the lower seal reinforcing ridge 13 b pressed downward from the upper seal reinforcing ridge 13 b is also elastically deformed so as to approach the end surface of the insert member 20. The operations of the upper inclined contact portion 13a and the seal reinforcing ridge portion 13b are vertically symmetrical with the operations of the lower inclined contact portion 13a and the seal reinforcing ridge portion 13b. In this way, as shown in FIG. 5B, the upper and lower seal reinforcing protrusions 13 b and 13 b are pressed against the end surface of the insert member 20, and the lateral gap 41 on the end surface of the insert member 20 is narrowed. To go. In other words, the step forming portion 13 composed of the inclined contact portion 13a and the seal reinforcing protrusion 13b is partially and elastically closely adhered to the end surface of the insert member 20 so as to be dragged by the elastic deformation of the above two modes. (See FIG. 5B).

  When the mold clamping further proceeds to the state shown in FIG. 5 (c), the mutual pressing between the upper and lower seal reinforcing protrusions 13b and 13b is increased and both are elastically deformed and flattened, and the lower surface of the insert member 20 is flattened. And the gap 40 between the seating plate 11 of the lower packing 10L and the gap 40 between the upper surface of the insert member 20 and the seating plate 11 of the upper packing 10U substantially disappear, and the end surface of the insert member 20 and the lower and upper side The gap 41 on the side of the step forming portion 13 (the inclined contact portion 13a and the seal reinforcing ridge portion 13b) is also considerably reduced.

  When the mold clamping further proceeds to the state shown in FIGS. 5D and 4C, the lateral gap 41 is almost completely eliminated, and the outer surface of the insert member 20 and the inner surfaces of the pair of upper and lower packings 10U and 10L. And strongly adhere to the whole. At this time, the lower ends of the side plate portions 32, 32 on both sides of the upper mold 30U are in contact with or sufficiently close to the upper ends of the side plate portions 32, 32 on both sides of the lower mold 30L ( 5A and 5B are separated from each other). 5D and 4C, the upper and lower molds 30U, 30L and the upper and lower packings 10U, 10L are in close contact with each other without a gap, and the upper and lower packings 10U, 10L The insert member 20 is also in strong contact with no gap, and resin leakage from the boundary of the external drawer of the insert member 20 protruding from the cavity 33 to the outside of the molds 30U and 30L can be reliably prevented.

As a result of the above, when performing injection molding of molded resin molded products using molten resin, even if the molten resin is of low viscosity such as liquid epoxy resin, it is caused by the dimensional tolerance that was on the end face of the insert member Therefore, it is possible to reliably and firmly seal the gap with the packing that is difficult to avoid. Thus, even without severe consideration the point of dimensional tolerance, it is possible to reliably prevent the leakage of resin. This is useful in avoiding an increase in parts cost and sorting / inspection work cost. In addition, there is no need to extremely soften the constituent material of the packing, and the packing can be configured to have an appropriate elastic strength, so that the position accuracy of the insert member to be carried can be secured sufficiently high.

As described above, the packing is used in a pair of upper and lower pairs as in the above-described embodiment, and there is also a single use form. FIG. 6 is an operation explanatory diagram showing a change from the state immediately before completion of mold clamping corresponding to FIG. 5 to the state of completion of mold clamping in another embodiment of the present invention.

In this other embodiment, the opening formed on the mating surface of the upper and lower molds 30U, 30L is due to a recessed portion formed in the lower mold 30L, and the upper mold 30U is recessed. There is no entrance and the surface is flat. The lower packing 10L is set in the recessed portion (mold opening) of the lower mold 30L. The upper side of the insert member 20 placed on the seat plate 11 is above the upper side. The packing 10U does not exist and can be pushed down directly by a flat surface which is the lower surface of the upper mold 30U.
When the mold clamping is performed as shown in FIG. 6A, the upper mold 30U is moved downward to cover the lower mold 30L and the insert member 20 on the lower packing 10L. The lower end face corners 21 and 21 of the insert member 20 are in contact with the middle part of the inclined contact portion 13a of the lower packing 10L (see FIG. 6A).

  Next, the mold clamping is advanced by forcibly pushing down the upper mold 30U. That is, as shown in FIG. 6B, the upper mold 30U is moved closer to the lower mold 30L, and the seal reinforcement protrusion of the lower packing 10L is caused by the flat surface of the upper mold 30U. The strip portion 13b is pressed and elastically deformed together with the inclined contact portion 13a.

  The lower end face corner portion 21 of the insert member 20 presses the middle portion of the inclined contact portion 13a of the lower packing 10L downward, similarly to the above, through the state of FIG. d) The mold clamping completion state is reached. As a result, the upper mold 30U and the lower packing 10L are in close contact with each other without any gap, and the insert member 20 and the lower packing 10L are also in close contact with each other without any gap. , 30L can be reliably prevented from leaking from the boundary portion of the external drawer of the insert member 20 protruding to the outside.

  As a result, the same effects as those of the above-described embodiment can be obtained.

  In addition, about the form of the inclination contact part 13a, although it was set as the concave curve shape in said Example, it may replace with this and it may be a slope shape (taper shape). Further, the seal reinforcing protrusion 13b may be trapezoidal or triangular.

  The present invention provides an appropriate position accuracy of the insert member to be supported even in the case of using a low-viscosity molten resin in the resin leakage prevention packing used when molding the insert member in an external projecting state in injection molding. This is useful as a technique for reliably preventing resin leakage from the gaps at the end faces of the insert member while ensuring.

10U upper packing 10L lower packing 11 seat surface plate portion 12 thick outer end portion 13 step forming portion 13a inclined contact portion 13b seal reinforcing protrusion 20 insert member 21 end face corner portion 30U upper die 30L lower side Mold 33 cavity

Claims (8)

Seals the opening facing the mating surface of a pair of molds to be clamped, and between the outer side surface of the insert member and the inner side surface of the opening that are arranged through the opening and inside and outside the cavity of the mold. A resin leakage prevention packing interposed between
A pair of thick outer end portions that are integrally connected in a state of providing a step of a predetermined height on both sides of the seat surface plate portion and position-control the end surface of the insert member. And
The step forming portion from the seat surface of the seat plate portion to the main surface of the thick outer end contacts the inclined contact portion in a posture inclined with respect to the end surface corner of the insert member, and the inclined contact portion. A seal reinforcing ridge that continuously swells on the opposite side of the seat surface with respect to the main surface of the thick outer end,
When the insert member is moved closer to the seat plate portion by clamping the mold from a state in which the end surface corner portion of the insert member is in contact with the inclined contact portion, the insert member is pressed by the end surface corner portion of the insert member. Further, the inclined contact portion is elastically deformed, and accordingly, the seal reinforcing protrusion is pressed and elastically deformed so that the step forming portion is in close contact with the end surface of the insert member. Resin leak-proof packing characterized by the above.   The resin leakage prevention packing according to claim 1, wherein the inclined contact portion is formed in a concave curved shape.   The resin leakage prevention packing according to claim 1, wherein the inclined contact portion is formed in a slope shape.   2. The resin leakage prevention packing according to claim 1, wherein the height of the seal reinforcing ridge is set to about half of the step.   The resin leakage prevention packing according to claim 1, wherein the seal reinforcing ridge portion has a half arc shape. Resin leakage prevention gasket according to claim 1 as a whole thick outer end portion of the front Symbol a pair and the seat surface plate portion is made of rubber. The opening is formed by aligning a pair of molds each having a recessed portion formed on the mating surface in an aligned state between the recessed portions,
The resin leakage prevention packing according to any one of claims 1 to 6, wherein the packing is set and used in each of the recessed portions of the pair of molds. The opening is formed by mold matching between a mold having a recessed portion formed on the mating surface and a mold having a flat mating surface,
Resin leakage prevention gasket according to any one of up to claims 1 to 6 for use are setting only to the recesses of the mold recess is formed on the mating surface.

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