JP4884727B2 - Molding equipment - Google Patents

Description

  The present invention relates to a molding apparatus for molding a molded article made of foamed resin such as a seat back portion of a vehicle.

  Generally, in this type of molding apparatus, an open / close die such as an upper die or a core die is connected to a lower die so as to be openable and closable. Then, in a state where the open / close mold is closed with respect to the lower mold, the resin raw material is foamed in the cavity formed between the molding surfaces of those molds, so that a molded product such as a backrest portion is molded. It has become so.

  By the way, in this type of molding apparatus, the gas at the time of foaming of the resin raw material in the cavity is accumulated inside the downward molding surface of the open / close mold such as the upper mold or the core mold disposed on the upper side of the cavity. A so-called gas reservoir is formed. In such a case, there is a problem in that a missing portion is generated in the molded product at the gas reservoir. In order to deal with such a problem, in the conventional molding apparatus, a gas venting device is connected to a portion where a gas pool is likely to be generated in the cavity, and the gas accumulated in the cavity is extracted through the gas venting device. I was doing.

Further, in the method disclosed in Patent Document 1, when a portion where the resin raw material wraps around due to the shape of the molding surface of the cavity, the resin raw material is bypassed at a short distance to the wrapping portion. A passage is formed so as not to cause a gas pool due to the wraparound of the resin raw material.
JP 2002-336089 A

  However, in the conventional molding apparatus, since the gas venting tool is adapted to locally extract the gas in the cavity by means of a thin pipe, the extraction part is spot-like. Therefore, if the gas reservoir is arranged at a position deviated from the degassing position by the degassing device, the gas cannot be extracted. Therefore, when there are many portions where gas needs to be vented, it is necessary to provide a large number of gas venting devices, and the cost is considerably increased due to the fact that the gas venting devices are originally expensive. And since the degassing tool needs to be cleaned frequently, if the number increases, it will be inevitable that cleaning work will become complicated. In addition, there are areas where degassing equipment cannot be installed due to restrictions imposed by the peripheral equipment of the molding equipment, etc., and degassing cannot be performed in the area corresponding to this area, and therefore, lack of thickness is prevented in this area. I can't.

  Moreover, in the prior art disclosed in Patent Document 1, since only the bypass of the resin raw material is bypassed, it is possible to prevent gas accumulation in a portion other than the bypass portion, for example, a flat portion of the molding surface. It is not possible to effectively prevent the lack of a molded product.

  The present invention has been made paying attention to such problems existing in the prior art. An object of the present invention is to provide a molding apparatus that can effectively extract gas from the inside of a cavity and suppress the possibility of a lacking portion occurring in a molded product.

In order to achieve the above object, the present invention comprises a lower mold, a core mold that is openably and closably connected to the lower mold, and an upper mold that is openably and closably connected to the lower mold. In the molding apparatus provided, the core mold is formed so as to form a first vent hole that opens toward the outside on a dividing surface of the lower mold and the core mold, and to communicate with the vent hole. Forming a first gas vent groove on the downward molding surface, and wrapping a tip end portion of the first gas vent groove and a base end portion of the first gas vent hole ; with the split surface of the upper mold to form a second vent hole opened outward, its so as to communicate with the gas vent hole, downward of the molding surface of the upper mold and the second degassing forming a groove was wrapped a proximal end of the second degassing groove of the tip portion and the second gas vent holes this It is characterized in.

Therefore, when the resin raw material is foamed in the cavity with the upper mold and the core mold closed with respect to the lower mold, the gas generated in the cavity passes through the gas vent groove to the gas vent hole. After being guided, it is discharged to the outside through the vent hole. Therefore, unlike the conventional apparatus, it is possible to effectively extract gas from the cavity without using a gas venting tool, and it is possible to suppress the possibility of a lacking portion occurring in the molded product.

In addition, it is not necessary to prepare a gas venting tool separately, and it is only necessary to form a gas venting hole on the dividing surface of each mold and to form a gas venting groove on the molding surface, so that the structure is simple and the cost is reduced. it is possible, as possible out also possible to omit the cleaning venting device.
Furthermore, the strength of the ribbon-shaped molded part formed in the gas vent hole can be improved, and when the molded product is taken out from the cavity, the ribbon-shaped molded part is separated from the molded product and This eliminates the need to perform an extra operation such as removing the ribbon-shaped molded portion.

In the above configuration, the bottom of the recess formed in the molding surface of the lower mold is connected to the first vent hole formed in the dividing surface of the lower mold and the core mold . 3 degassing grooves are formed.

  Therefore, in this case as well, only the position of the gas vent groove is different, and the gas can be effectively extracted from the cavity without using a gas venting device as described above, and a thin portion is generated in the molded product. The risk of doing so can be suppressed.

Further, in the above-described configuration, when the width of the gas vent groove is W and the depth is D, 1.5 mm ≦ W ≦ 3.0 mm and 2.0 ≦ D / W ≦ 3.0 It can comprise so that it may represent with the relational expression of these.

  When configured in this way, the width and depth of the gas vent groove can be set appropriately, and the gas can be effectively extracted through the gas vent groove when the resin raw material is foamed. It is possible to prevent the rib-shaped molded part from remaining broken in the gas vent groove when the mold is released.

  As described above, according to the present invention, it is possible to effectively extract gas from the cavity at a low cost without using a gas venting tool, thereby eliminating the possibility of a lacking portion occurring in a molded product. be able to.

(First embodiment)
Below, 1st Embodiment of this invention is described based on FIGS.
The molding apparatus according to the first embodiment molds the backrest of the seat shown in FIG. 1 and FIG.

  As shown in FIGS. 3 and 4, in this molding apparatus, an upper mold 12 as an open / close mold is connected to a lower mold 11 via a hinge 13 so as to be openable and closable at one end. A core die 14 as an open / close die is connected to the lower die 11 so as to be openable / closable via a hinge 15 at one end on the same side as the upper die 12 so as to be positioned between the lower die 11 and the upper die 12. ing. In the state where the upper mold 12 and the core mold 14 are closed with respect to the lower mold 11, the resin raw material P is foamed in the cavity C formed between the molding surfaces 11a, 12a, and 14a. The molded product M is molded.

  As shown in FIG. 3 and FIG. 5 (sectional view taken along line 5-5 in FIG. 3), a plurality of shallow groove shapes are formed between the divided surfaces of the upper mold 12 and the core mold 14 in the closed state. Gas vent holes 16 are formed at predetermined intervals, and one end portions of the gas vent holes 16 are opened in the cavity C and the other end portion is opened outside the cavity C. On the downward molding surface 12a of the upper mold 12 arranged above the cavity C in the mold closed state, a plurality of side-section substantially triangular gas vent grooves 17 are formed at predetermined intervals. The right end in FIG. 3 communicates with the lower end of each gas vent hole 16.

  As shown in FIGS. 3 and 6 (cross-sectional view taken along line 6-6 in FIG. 3), the lower mold 11 and the core mold 14 are closed on the opposite side of the vent hole 16 through the cavity C. Between the divided surfaces, a plurality of gas vent holes 18 having a wide shallow groove shape are formed at predetermined intervals. One end portions of the gas vent holes 18 are opened in the cavity C, and the other end portion is formed. Opened outside the cavity C. A plurality of degassing grooves 19 and 20 are formed on the downward molding surface 14a of the core mold 14 disposed on the upper side of the cavity C in a closed state so as to extend in a crossing manner at predetermined intervals. The right end of each gas vent groove 19 extending in the left-right direction is communicated with the lower end of each gas vent hole 18.

The gas vent grooves 19 and 20 on the molding surface 14a of the core mold 14 are 1.5 mm ≦ W ≦ 3.0 mm when the width is W and the depth is D, and 2. It is configured to be expressed by a relational expression of 0 ≦ D / W ≦ 3.0. For example, the degassing grooves 19 and 20 are formed so that the width W is 2.5 mm and the depth D is 5 mm.

Next, the operation of the molding apparatus configured as described above will be described.
Now, after the resin raw material P is put on the molding surface 11a of the lower mold 11 in a state where the upper mold 12 and the core mold 14 are opened with respect to the lower mold 11, as shown in FIG. When the mold 12 and the core mold 14 are closed on the lower mold 11, a cavity C is formed between the molding surfaces 11a, 12a, and 14a of the molds 11, 12, and 14. In this state, when the resin raw material P is expanded and expanded, the expanded and expanded resin raw material P is gradually moved upward in the cavity C as shown by the arrows in FIG. The As a result, a molded product M made of foamed resin at the backrest portion of the seat in the vehicle as shown in FIGS. 1 and 2 is formed.

  In this case, a plurality of degassing grooves 17, 19, 20 communicate with the degassing holes 16, 18 on the downward molding surfaces 12 a, 14 a of the upper mold 12 and the core mold 14 disposed above the cavity C. It is formed to do. For this reason, the gas in the cavity C generated with the foaming of the resin raw material P is guided to the gas vent holes 16 and 18 through the gas vent grooves 17, 19 and 20, and then the gas vent holes 16 and 18. It is discharged to the outside through. Therefore, a gas reservoir portion does not occur in the cavity C, and the possibility of a lacking portion occurring in the molded product M can be suppressed.

  After the gas is exhausted, each of the gas vent grooves 17, 19, and 20 is filled with the resin raw material P, and as shown in FIGS. 1 and 2, a triangular rib-shaped molded portion Ma and a low lattice are formed on the back side of the molded product M. A rib-shaped molded part Mb is formed. Further, the resin raw material P is filled in the gas vent holes 16 and 18, and a plurality of ribbon-like protrusions Mc and Md are formed on the periphery of the molded product M in succession to the molding parts Ma and Mb.

In this embodiment, the width W and the depth D of each of the gas vent grooves 17, 19, and 20 are 1.5 mm ≦ W ≦ 3.0 mm and 2.0 ≦ D / W ≦ 3. 0.0, the width W is about 2 mm, and the depth D is about 5 mm. For this reason, the gas can be effectively extracted through the gas vent grooves 17, 19, and 20, and when the molded product M is released, the rib-shaped molded portions Ma and Mb are formed in the gas vent grooves 17, 19, and 20. The possibility of remaining broken can be prevented.

  Incidentally, when the width W of the gas vent grooves 17, 19, 20 exceeds 3.0 mm or the ratio to the depth D is smaller than 1.5, the resin raw material in the gas vent grooves 17, 19, 20 As the propulsive force of P increases, the resin raw material P is filled in the gas vent grooves 17, 19, and 20 at an early stage, and the gas is not effectively discharged. On the other hand, when the width W is smaller than 1.5 mm or the ratio with the depth D exceeds 3.0, the rib-shaped molding parts Ma and Mb become too thin and the mold M is released. Sometimes the molded parts Ma and Mb are easily broken and remain in the gas vent grooves 17, 19, and 20, and the removal and cleaning becomes troublesome.

When the molded product thus formed is a backrest portion, the ribbon-like protrusions Mc and Md are removed, and the entire outer peripheral surface is covered with a fabric or leather skin.
The first embodiment described above has the following effects.

  (1) Since the degassing grooves 17 and 19 are formed in the downward molding surfaces 12a and 14a forming the cavity C so as to degas, it is different from the case where the conventional degassing device described above is provided. A wide range of gases can be vented. Therefore, the lack of the molded product M can be appropriately prevented, and the commercial value of the molded product M can be increased.

(2) Since the configuration for venting the gas is merely the formation of the gas vent grooves 17 and 19 on the molding surfaces 12a and 14a, the number of parts is not increased, and the configuration is simple and low cost.
(3) As described above, the configuration for venting the gas is merely formed by the gas vent grooves 17 and 19 on the molding surfaces 12a and 14a. Gas vent grooves 17 and 19 can be formed at necessary positions. Therefore, it is possible to effectively prevent the lack of the molded product.

  (4) Since no gas venting device is used as a configuration for venting gas, and the gas vent grooves 17 and 19 are formed in a shape in which no ribs remain therein, the molding surfaces 12a and 14a Cleaning is not complicated.

(Second Embodiment)
Next, a second embodiment of the present invention will be described with respect to parts different from the first embodiment.
As shown in FIG. 7B, in the second embodiment, the gas vent groove 17 of the upper mold 12 of the molding apparatus is extended to a part of the gas vent hole 16 and the tip of the gas vent groove 17 is extended. The portion and the base end portion of the gas vent hole 16 wrap at the portion R. PL indicates a parting line between the core mold 14 and the upper mold 12. For this reason, in the molded product M molded by this molding apparatus, as shown in FIG. 7A, a gas vent hole is formed with respect to the tip of the rib-shaped molded portion Ma molded by the gas vent groove 17. The base end portion of the ribbon-like protruding piece Md formed at 16 is integrally continuous at the wrap portion Ra. Therefore, when the strength of the projecting piece Md is improved and the molded product M is removed from the cavity C, it is possible to effectively prevent the projecting piece Md from remaining in the gas vent hole 16 and to remove the remaining projecting piece Md. It can save extra trouble.

(Third embodiment)
Next, a third embodiment of the present invention will be described.
As shown in FIG. 8A, in the third embodiment, molding is performed so that a recess Me for accommodating the reclining mechanism component is formed at the lower end of the molded product M as the backrest. . And as shown in FIG.8 (b), in order to shape | mold the recessed part Me, the convex part 11b is partially formed in the molding surface 11a of the lower mold | type 11 of a shaping | molding apparatus. A gas vent groove 21 communicating with the gas vent hole 18 is formed at the bottom of the concave portion 11c adjacent to the convex portion 11b (corresponding to the convex portion of the molded product M).

  Accordingly, even if the concave portion 11c adjacent to the partial convex portion 11b is formed in the molding apparatus and the convex portion adjacent to the concave portion Me is formed in the molded product M as in the third embodiment, the convex portion The lack of part can be prevented.

(Example of change)
In addition, this embodiment can also be changed and embodied as follows.
-In the said embodiment, it comprises so that the outer opening part of each degassing hole 16 and 18 may be connected to the degassing mechanism of the whole shaping | molding apparatus, and the gas in the cavity C is made into each degassing groove 17, 19 and 20 and each vent hole 16 and 18 should be positively extracted.

The present invention is embodied in a molding apparatus for molding other molded products such as seats and headrests other than the backrest as the molded product M, for example .

  In the third embodiment, the convex portion 11b of the lower mold 11 is formed sideways.

The rear view which shows the molded product shape | molded with the shaping | molding apparatus of embodiment. Sectional drawing in the 2-2 line of FIG. Sectional drawing which shows the state at the time of shaping | molding of the shaping | molding apparatus of 1st Embodiment. Sectional drawing which shows the open state of the shaping | molding apparatus of 1st Embodiment. FIG. 5 is a partially enlarged sectional view taken along line 5-5 in FIG. FIG. 6 is a partially enlarged sectional view taken along line 6-6 in FIG. 3; (A) is a partial perspective view which shows the molded product shape | molded by the shaping | molding apparatus of 2nd Embodiment, (b) is a partial cross section figure which shows the shaping | molding state by the shaping | molding apparatus of 2nd Embodiment. (A) is a partial perspective view which shows the molded product shape | molded by the shaping | molding apparatus of 3rd Embodiment, (b) is a partial cross section figure which shows the shaping | molding state by the shaping | molding apparatus of 3rd Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 ... Lower mold | type, 11a ... Molding surface, 11b ... Convex part, 11c ... Recessed part, 12 ... Upper mold as an opening / closing mold, 12a ... Molding surface, 14 ... Core mold as an opening / closing mold, 14a ... Molding surface, 16, 18 ... degassing holes, 17 ... second degassing grooves, 19, 20 ... second degassing grooves, 21 ... third degassing grooves , C ... cavity, D ... depth, W ... width, P ... Resin raw material, M ... molded product.

Claims (3)

In a molding apparatus comprising a lower mold, a core mold connected to the lower mold so as to be opened and closed, and an upper mold connected to the lower mold so as to be opened and closed,
A split surface of the lower mold and the core mold is formed with a first gas vent hole that opens toward the outside, and is formed on the downward molding surface of the core mold so as to communicate with the gas vent hole. are formed a first gas release groove, to wrap a proximal end of said the tip portion of the first gas release groove first degassing holes,
The split surface of the core mold and the upper mold is formed with a second vent hole that opens outward, and the upper mold has a downward molding surface so as to communicate with the vent hole. A molding apparatus characterized in that a second gas vent groove is formed to wrap a tip end portion of the second gas vent groove and a base end portion of the second gas vent hole . A third gas vent groove is formed at the bottom of the recess formed in the molding surface of the lower mold so as to communicate with the first gas vent hole formed in the split surface of the lower mold and the core mold. The molding apparatus according to claim 1, wherein the molding apparatus is formed. When the width of the gas vent groove is W and the depth is D,
1.5mm ≦ W ≦ 3.0mm
And,
2.0 ≦ D / W ≦ 3.0
The molding apparatus according to claim 1, wherein the molding apparatus has a shape represented by the relational expression:

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