TW201422409A - Blow molding mold, blow molding method, and method for manufacturing molded article - Google Patents

Abstract

Provided are a blow molding mold, a blow molding method, and a method for manufacturing a molded article that enable the thickness of a deep drawn portion to be sufficiently maintained when blow molding a molded article in which the deep drawn portion is arranged adjacent to the weld portion of a parison. The blow molding mold and blow molding method form a molded article having: a weld portion formed by welding the inner surface of the parison; and a deep drawn portion arranged in the proximity of the weld portion. The blow molding mold is provided with a first mold and a second mold that form the weld portion by clamping. The second mold is configured from: a first split mold having a mold surface for forming the weld portion and a mold surface that constitutes a part of a deep draw recess for forming the deep drawn portion; and a second split mold having a mold surface that constitutes the remaining section of the deep draw recess. After blow molding, the deep drawn portion is cut at the mid point in the depth direction to form an opening, and the molded article is completed.

Description

Blow molding die, blow molding method, and manufacturing method of molded article

The present invention relates to a blow molding die, a blow molding method, and a method of producing a molded article, and particularly relates to a molded article which is very suitable for a molded article having a deep drawn shape portion in the vicinity of a fusion portion of a parison. An air blow molding die, a blow molding method, and a method of manufacturing a molded article.

In the instrument panel of the automobile, various air-conditioning ducts are attached. For example, in Patent Document 1, the inside of the vehicle instrument panel having a plurality of air outlets is provided, and the adjustment air is supplied from the air-conditioning unit to each of the air outlets. The structure of the duct. The air duct of Patent Document 1 is formed such that the lower defrosting duct and the lower central duct are integrally formed to constitute a lower front duct, and the upper defensive duct is formed from the upper side to the lower defrosting duct to be formed therein. The defrosting duct of the frost air passage also constitutes a central duct that joins the upper central duct to the lower central duct to form an air duct of the air conditioning air passage inside.

Similarly, in Patent Document 2, an air-conditioning duct in which a central duct portion, a booster duct portion, and a defrosting duct portion are integrally formed is disclosed. In the air conditioning duct disclosed in Patent Document 2, the first mount or the second mount is integrally formed, and the mounts are fixed to the automobile frame or the instrument panel, whereby the air conditioner duct is installed in the instrument panel.

As described in these patent documents, the air conditioning duct in the instrument panel must A hollow molded body having a complicated shape, as described in Patent Document 2, is generally formed by air blowing.

[First technical literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. Hei 11-198681

[Patent Document 2] Japanese Patent Laid-Open Publication No. 2003-136941

Further, in the air conditioning duct, for example, when the defrosting duct is used, it is necessary to provide the air vent along the front window, and in many cases, the air vent of the elongated shape protrudes toward the front window. When it is desired to form the air supply opening for the front window by the above-described air blow molding, it is necessary to form a deep-drawn drawing portion which is elongated and has a certain depth, and the moldability of the portion is required to be large.

In the deep drawing shape portion, when the opening size is small and the depth is deep, the parison is largely stretched at the time of blow molding, the wall thickness becomes very thin, and there is a possibility that the strength cannot be sufficiently ensured. . When the strength of the deep drawing shape portion is insufficient, the reliability of the defrosting duct is lowered. Further, when the air blowing port is formed, it is necessary to cut the tip end portion of the deep drawing shape portion to form an opening portion. However, when the rigidity of the deep drawing shape portion is insufficient, there is a problem that the cutting operation is difficult. In the vicinity of the fusion portion, resin accumulation is also likely to occur, which also causes difficulty in cutting work.

In order to eliminate these problems, the concave portion corresponding to the deep drawing shape portion is divided and formed on the opposing faces of the pair of molds, and the molds are joined to form Just fine. When the direction of the depth direction of the shape portion is drawn from the orthogonal direction, and the pair of molds are sandwiched to perform the air-blowing molding, the depth of the concave portion of each of the molds is formed as long as one half of the original opening size of the deep-drawn drawing portion is formed. That is, the wall thickness reduction by stretching can be suppressed.

However, in the mold clamping direction of the mold, there are various restrictions due to other factors, and it is not possible to take the above-mentioned deep drawing shape portion as a priority. For example, as described in Patent Document 2, the defrosting duct must be provided for the portion mounted on the instrument panel. The mounting portion is not hollow, and it is necessary to form a fusion portion (compression portion) after crushing the parison, and when blowing, it is necessary to sandwich the portion with the flat surface of the mold. Therefore, when the deep drawing shape portion is provided in the vicinity of the mounting portion, it is necessary to preferentially form the fusion portion, and it is difficult to eliminate the above-described problem in the deep drawing shape portion.

The present invention has been made in view of the above-described circumstances, and it is an object of the present invention to provide a molded article in which a deep drawn portion is sufficiently ensured when a melted portion of a blow molded preform and a deep drawn portion are closely arranged. A blow molding die having a wall thickness, a blow molding method, and a method of producing a molded article.

In order to achieve the above object, in the air blow molding die of the present invention, a molded article having a fusion portion and a deep drawing shape portion is formed, and an inner surface of the parison is formed by melting the fusion portion, and the deep drawing shape portion is formed. Located in the vicinity of the melting portion, the first mold and the second mold are formed by the mold clamping portion, and the second mold is composed of a first split mold and a second split mold. The first split mold has a mold surface for forming the fusion portion and a mold surface constituting a part of the deep drawing concave portion for forming the deep drawing shape portion, and the second split mold has the deep drawing The rest of the dimple Mold surface.

Further, in the air blowing forming method of the present invention, the aforementioned air blowing forming is used. In the mold, the first mold and the second split mold are gradually approached in a predetermined mold clamping direction, and the first split mold is blown while approaching the first mold and the second split mold. The first mold, the first split mold, and the second split mold are clamped. Further, in the method for producing a molded article of the present invention, after the air blow molding by the air blow molding method, the deep drawing shape portion is cut at a position in the depth direction to form an opening.

The second mold is made into the first split mold and the second split mold By dividing into two, it is possible to ensure the formability of both when forming the fusion portion and forming the deep drawing shape portion. In particular, in the deep drawing shape portion, the parting line is formed by division, and the stretching of the parison is alleviated. Further, since the excess parison which is a cause of resin accumulation is effectively used for the formation of the deep drawing shape portion, no resin accumulation occurs in the vicinity of the fusion portion.

According to the present invention, even if the melted portion of the blow molded preform is When the molded article in which the shape portion is arranged in close proximity is deeply drawn, the thickness of the deep drawing shape portion can be sufficiently ensured, and the strength and rigidity are excellent, and a molded article which can be easily subjected to cutting processing or the like can be obtained.

1‧‧‧Central duct

2,3‧‧‧ side exhaust duct

4,5‧‧‧Pre-defrost air supply

6,7,8,9‧‧‧Installation Department

21‧‧‧Mold

22‧‧‧Blank

23‧‧‧1st mould

24‧‧‧2nd mould

31‧‧‧1st mould

32‧‧‧1st split mold

33‧‧‧Second split mold

31a, 32a‧‧‧Fabric formation

32b, 33b‧‧‧Drawing recesses for forming the shape portion

32c, 32d‧‧‧ pinch

32e‧‧‧ containment recess

31f‧‧‧ tiny protrusions

32f‧‧‧ tiny recesses

Fig. 1 is a perspective view showing a schematic configuration of a defrosting duct.

Fig. 2 is a schematic view showing blow molding.

Fig. 3 is a view showing two molds of a first mold and a second mold, and a forming tool The drawing of the molded case in the case where there is a molded portion of the molten portion and the deep drawn portion is (a) the initial state of the mold clamping, (b) the state in which the mold clamping is in progress, and (c) the state in which the mold clamping is completed.

Fig. 4 is a schematic cross-sectional view showing an important part of a blow molding die to which the present invention is applied.

Fig. 5 is a view showing a molding state in which a molded article having a fusion portion and a deep drawing shape portion is molded by applying the air blowing mold of the present invention, (a) is an initial state of mold clamping, and (b) is a system. The state of the mode-locking is in progress, and (c) is the end state of the mode-locking.

Fig. 6(a) is a view showing a state in which the first split mold is clamped in the direction of the mold clamping of the first mold and the second split mold, and Fig. 6(b) shows the first mold in the skew. A schematic view of the case where the first split mold is clamped in the mold clamping direction of the second split mold.

Fig. 7 is a view showing an example of an air blowing mold when a projection is formed in a fusion portion.

Fig. 8(a) is a view showing a state in which the parison is eaten and cut in the tip end portion of the deep drawing shape portion, and Fig. 8(b) shows a state in which the mold is not clamped in the cut portion. Figure.

Hereinafter, embodiments of the blow molding die, the air blow molding method, and the method of manufacturing the molded article to which the present invention is applied will be described in detail with reference to the drawings.

First, a defrosting duct which is an example of a molded article formed by using the air blowing mold of the present invention will be described.

The defrosting duct of this example is installed in the dashboard of a car. Although not shown in the drawings, the articles are placed on the air conditioning duct in an overlapping state. As shown in Fig. 1, the central air duct portion 1 for suction is at the center, and has curved side exhaust ducts 2, 3 extending to the left and right, and exhaust ducts 2, 3 on each side. It has a ventilation port facing the interior of the car or a side defroster air supply port.

Moreover, in front of the center duct portion 1, along the front windshield, The front defroster air outlets 4, 5 form an elongated opening. Further, at the front position of the front defrosting air supply ports 4, 5, the mounting portions 6, 7, 8, and 9 for mounting the defrosting air duct on the instrument panel form four spaces. These mounting portions 6, 7, 8, and 9 are not hollow, and a compression portion that crushes the parison to be fused is formed.

The defrosting duct having the above configuration is formed into a hollow resin The shape and forming method are formed by air blowing. 2 is a schematic view showing a basic configuration of the blow molding, and the hollow cylindrical resin layer (parison) 22 supplied from the mold 21 is sandwiched by a pair of molds (the first mold 23 and the second mold 24). Into, air is fed into the parison 22. Thereby, the parison is pressed against the inner wall of the first mold 23 and the second mold 24 that are clamped, and a hollow body corresponding to the cavity shape of the first mold 23 and the second mold 24 is formed.

Here, in the air blowing forming of the aforementioned defrosting duct, it is necessary to make the front The defrosting air supply ports 4, 5 protrude from the front windshield side. Further, in the characteristics of the blow molding, the front defrosting air outlets 4, 5 cannot be formed with the opening portion first, and the so-called deep drawing shape portion must be formed, and the tip end or the like must be cut, and the position in the depth direction is halfway. Cut to make an opening.

Further, the defrosting air supply ports 4, 5 are formed before the deep drawing of the shape portion, and the mounting portions 6, 7, 8, and 9 form a fusion portion (compression portion). Such a When the deep drawing shape portion and the fusion portion are arranged close to each other, in the air blowing by the pair of dies (the first die 23 and the second die 24), the wall thickness of the deep drawing shape portion is The tendency to thin.

For the thinning of the deep-drawn shape portion, refer to Figure 3 Description. Further, the drawing of Fig. 3 and subsequent figures is a cross-sectional view of the x-x line position of Fig. 2, which is a horizontal sectional view of the mold viewed from above.

The first mold 23 and the second mold 24 are used to form the above shape In the case of the defrosting duct, it is necessary to use the first mold 23 and the second mold 24 having the fused portion forming faces 23a, 24a for forming the fused portions (the mounting portions 6, 7, 8, 9), respectively. Further, in the second mold 24, the deep drawing concave portion 24b for forming the deep drawing shape portions (the front defroster air blowing ports 4, 5) must be formed.

When the first mold 23 and the second mold having such a configuration are used When forming the defrosting duct, first, as shown in Fig. 3(a), the parison 22 is sandwiched between the first mold 23 and the second mold 24, and air is blown into the parison 22 while the mold is being locked. Blowing inside. At this time, as the mold clamping progresses, the parison 22 comes into contact with the opening edge of the deep drawing concave portion 24b of the second mold 24, and as shown in Fig. 3(b), the parison 22 draws the concave portion from this state deep. The inside of 24b is expanded. Finally, as shown in Fig. 3(c), the parison 22 is adhered to the wall surface of the deep drawing recess 24b.

In the above forming, the type stretched into the deep drawing recess 24b The length of the blank 22 is determined by the opening size L1 of the deep drawing recess 24b of the second die 24, and the shorter parison 22 restricted by the opening size L1 is pulled in the deep drawing recess 24b. Stretched and became thin. Further, when the fusion portion is formed, the two parisons 22 are crushed in close contact with each other. Therefore, the excess resin is pushed out and the resin accumulation (wall thickness accumulation) occurs at the position A in the figure.

The thinning is carried out in the final molded product (defrost duct) The thinning of the deep drawing shape portion for forming the front defroster air supply ports 4, 5 causes a problem of insufficient strength in this portion. Further, since the rigidity due to the thinning is reduced or the resin accumulation occurs, the cutting operation for the front defroster air supply ports 4, 5 becomes difficult. There is a portion where the rigidity is insufficient due to thinning, and a portion where the thickness becomes thick and hard due to the accumulation of the resin is difficult to be cut by, for example, a cutter. Therefore, when cutting, it is necessary to use, for example, a serrated cutter, and it is necessary to use a grinding operation for smoothing the cut surface, and the work is complicated.

Here, in the present invention, the second portion forming the deep drawing shape portion is formed. The mold is divided into two parts, and is composed of three members of the mold, and the melted portion of the parison and the molded article in which the deep drawing shape portion is disposed are blow-molded.

Figure 4 is an embodiment of an air blowing mold to which the present invention is applied. The picture. The air blow molding die of the present embodiment is composed of a first die 31, a first split die 32, and a second split die 33. The first split mold 32 and the second split mold 33 are formed in a shape in which the second mold is divided.

Among the above molds, the first mold 31 and the first split mold 32. There are melting portion forming faces 31a, 32a for forming the aforementioned melting portion (compression portion). In addition, the first split mold 32 and the second split mold 33 have deep drawn portion forming recesses 32b and 33b which are divided into two types of the deep drawing shape portions, and are combined to form a deep drawing shape. Further, at the tip end position of the fusion-molded portion forming surface 31a of the first divided mold 32, the pinching portion 32c that cuts the excess parison is formed to form a projection. In the same manner, the end portion of the deep drawing portion forming recess 32b of the first split mold 32 (the end portion that is in contact with the second split mold 33) is regarded as a projection portion, and is taken as a cut-in excess parison. The pinch portion 32d, At the same time, a housing recess 32e for accommodating the excess parison is formed in the vicinity thereof.

Moreover, in the blow molding die of this example, the first split mold In the second split mold 33, the deep drawing shape portion forming recess portions 32b and 33b having the shape of the two-division deep drawing shape portion are formed, but the present invention is not limited thereto. The deep-drawn shape forming portion forming recessed portions 32b and 33b may be formed by dividing the deep drawing recessed portion 32b into a shape of the deep drawing recessed portion. 32 has a mold surface constituting a portion of the deep drawing concave portion, and a deep drawing shape portion forming concave portion 33b is formed, and the second divided mold 33 has a mold surface constituting the remaining portion of the deep drawing concave portion, and the division ratio or the division position may be used. Arbitrarily set. However, it is preferable to use the recessed portions 32b and 33b for forming the deep drawing shape portions of the two divided shapes described above.

Next, the blow molding method using the above-described blow molding die will be described. law. When the air blow molding is performed using the mold shown in Fig. 4, the first mold 31 and the second mold (the first split mold 32 and the second split mold 33) are opened, and the first split mold 32 and the second mold 32 are second. The split mold 33 is also supplied to the parison 22 while being opened. Further, the three molds (the first die 31, the first split die 32, and the second split die 33) are blown while being molded.

Figure 5 shows the use of the mold shown in Figure 4 over time. The surface of the blow molding. Similarly to the example shown in the third embodiment, when the air is blow molded, as shown in Fig. 5(a), the first mold 31, the first split mold 32, and the second split mold 33 are opened after the mold is opened. The parison 22 is blown into the parison 22 while being clamped. At this time, the parison 22 comes into contact with the first split mold 32 and the second split mold 33 as the mold clamping progresses. However, at this time, the first split mold 32 and the second split mold 33 are kept at a distance. Stretched The size L2 of the parison 22 which is drawn deep into the shape portion is longer than that of the example of Fig. 3. Further, as the mode locking of the fifth (b) and fifth (c) drawings is performed, the distance between the first split mold 32 and the second split mold 33 is reduced, and the parison 22 is drawn deep into the shape forming recess. 32b, 33b slack. Because of these factors, the recess 22b is formed in the shape forming portion 32b, and the parison 22 stretched in the 33b is margined, as shown in Fig. 5(c), even if the parison 22 is adhered to the first split mold. The deep drawing portion forming recesses 32b of the second split die 33 are stretched on the wall surface of the deep drawing portion forming portions 32b, and the thinning is also suppressed.

Regarding the fused portion forming faces 31a, 32a for forming the fused portion In the crushing of the parison 22, the first split mold 32 is clamped to the second split mold 33, and the parison that has been excessively clamped is pushed out into the deep-drawn shape forming portion recesses 32b and 33b. . As a result, no resin is formed, and the resin which is pushed out contributes to the formation of the deep drawing shape portion, and also acts to suppress the thinning due to the stretching of the parison 22 .

Further, in the above-described mold clamping, the first mold 31 and the second split mold The 33 series is clamped in the left and right direction in the figure. Further, the first split mold 32 must be mold-locked with respect to the first mold 31, and the second split mold 33 must also be mold-locked with respect to the first mold 31. At this time, from the viewpoint of the stroke of the first split mold 32, the mold clamping direction of the first split mold 32 is preferably the first mold 31 and the second split mold as shown in Fig. 6(a). The direction of the clamping mode of 33 is the direction of the orthogonal direction (front and rear direction: the upper and lower directions on the drawing).

Further, when the aforementioned fusion portion is formed, a surface is sometimes formed on the surface. Start. For example, the mounting portions 6, 7, 8, and 9 for mounting the aforementioned defrosting duct on the instrument panel are fixed on the instrument panel by means of ultrasonic welding, etc., but The protrusions allow the ultrasonic fusion to be performed smoothly. When such a projection is formed, as shown in Fig. 7, the microprotrusion portion 31f is formed on the fusion-molded portion forming surface 31a of the first mold 31, and accordingly, the fusion-forming portion forming surface 32a of the first split mold 32 is necessary. A minute recess 32f is formed.

In the formation of these minute protrusions 31f or minute recesses 32f In the mold clamping and mold opening of the first mold 31 and the first split mold 32, the mold clamping and mold opening directions of the first split mold 32 are made to the first mold 31 and the second mold as shown in Fig. 6(a). When the mold clamping direction of the split mold 33 is orthogonal, the minute projections 31f are hooked by the minute recesses 32f, and it is difficult to smoothly operate. In extreme cases, the mold is damaged. Therefore, when the projection is formed in the fusion portion, as shown in Fig. 6(b), it is preferable to lock the first split mold 31 with respect to the mold clamping direction of the first mold 31 and the second split mold 33. The mode direction is oblique. It is more preferable that the first split mold 32 is mold-locked and opened in the height direction of the minute projection portion 31f formed on the fusion portion.

The lock mold and the air blow are shown in Fig. 5, and the defrosting duct is formed as The hollow body, however, when the deep drawing shape portion is formed, as shown in Fig. 8(a), in the bottom portion of the deep drawing shape portion, if the cutting parison is sandwiched and eaten by the pinch portion 32d At the tip end, the parison 22 can be surely adhered to the inner walls of the deep drawing shape portion forming recesses 32b, 33b. Further, as shown in Fig. 8(b), the parison 22 can be made to abut against the bottom of the deep drawing shape portion, so that the parison 22 can be effectively utilized as much as possible, and the wall thickness of the deep drawing portion is made as thick as possible. .

Whether or not the tip end of the parison 22 is cut by the pinch-off portion 32d, It can be selected by controlling the timing of mode locking and blowing. After the parison 22 is sufficiently expanded, if the first split mold 32 and the second split mold 33 are in contact with each other, the parison 22 The tip end is pinched, and is cut by the pinch-off portion 32d against the second split mold 33. Further, if there is a slight timing of early clamping, when the mold clamping is completed before the parison 22 is fully expanded, the tip end of the parison 22 does not interfere with the bottom of the deep drawing shape forming recesses 32b, 33b, and is eaten and cut. Broken.

As described above, although a blow molded article can be obtained, it is In the case of the defrosting duct, the blow molded article is not a finished product. As described above, it is necessary to cut the tip formed at the deep drawing shape portion of the blow molded article to form a front defrosting air supply port. When the cutting is performed, the tip end portion of the deep drawing shape portion is obliquely cut toward the melting portion, for example, but the deep drawing portion has a thick wall thickness and high rigidity, and is in the vicinity of the melting portion. Since the resin does not form an accumulated resin, it can be easily cut using a conventional cutter. Further, it is not necessary to perform processing after polishing or the like.

In the present invention, by using the air-blowing molding and the above-described cutting of the above-described air blowing mold, a molded article (defrost air duct) can be obtained as a product, and the obtained molded product has a high strength in the deep drawing shape portion. It is very good in quality.

The embodiments of the present invention have been described above, but the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the invention.

22‧‧‧Blank

31‧‧‧1st mould

32‧‧‧1st split mold

32b‧‧‧Drawing recesses for forming the shape part

32d‧‧‧Clamping

32e‧‧‧ containment recess

33‧‧‧Second split mold

33b‧‧‧Drawing recesses for forming the shape part

Claims (10)

An air blow molding die for molding a molded article having a fusion portion and a deep drawing shape portion, wherein an inner surface of the parison is formed by melting the fusion portion, and the deep drawing shape portion is located in the vicinity of the fusion portion The first mold and the second mold which form the fusion portion by means of a mold clamping, the second mold is composed of a first split mold and a second split mold, and the first split mold has a a mold surface forming the fusion portion and a mold surface constituting a part of the deep drawing concave portion for forming the deep drawing shape portion, wherein the second divided mold has a remaining portion constituting the deep drawing concave portion Mold surface. The air blow molding die according to claim 1, wherein the melted portion is a compressed portion after the crushed parison is crushed. The blow molding die according to the first or second aspect of the invention, wherein the first split mold is slightly orthogonal to the mold clamping direction of the first die and the second split die. Being advanced. The blow molding die according to the first or second aspect of the invention, wherein the first split die is inclined in a direction of a mold clamping direction of the first die and the second split die. advance and retreat. An air blow molding method according to the first aspect of the invention, characterized in that the first mold and the second split mold are gradually brought closer to each other in a predetermined mold clamping direction, and the first 1 split mold side close to the first mold The second split mold is blown with the second split mold, and the first mold, the first split mold, and the second split mold are clamped. The blow molding method according to claim 5, wherein the first split mold advances and retreats in a direction slightly orthogonal to a mold clamping direction of the first mold and the second split mold. The air blow molding method according to claim 5, wherein the first split mold advances and retreats in a direction inclined with respect to a mold clamping direction of the first mold and the second split mold. A method of producing a molded article, which is characterized in that the deep drawing shape is cut at a midway position in the depth direction after the air blowing forming method according to any one of claims 5 to 7. The portion forms an opening. The method for producing a molded article according to claim 8, wherein the fused portion is obliquely cut. The method for producing a molded article according to claim 8 or 9, wherein the molded article is a defrosting duct.