JP2544847B2 - Insert piece used for insert blow molding - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to improvements in insert pieces used in insert blow molding.

[0002]

2. Description of the Related Art The insert blow molding method is a method in which an insert piece such as a handle or a suspender and a preform are placed in a blow molding die, and the preform is blow molded to obtain a blow molded product and an insert piece. It is a molding method that integrates and integrates.

In such an insert blow molding method, the molding cycle can be improved by automatically arranging the insert piece in the blow molding die. Japanese Unexamined Patent Publication No. 63-95931 discloses a technique for automatically carrying a handle as an insert piece to a predetermined position of a blow molding die.

According to this technique, the preform is of a neck type, and the handle can be conveyed to the biaxial stretch blow molding apparatus through the temperature adjusting device by the supporting pin which is movable integrally with the neck type. . Then, with the blow molding die composed of the split mold opened, the preform and the handle are placed in the mold, and then the mold is clamped, so that the handle, which is an insert piece, is held at the predetermined position of the blow molding mold. Can be placed at.

[0005]

In the technique disclosed in the above publication, the handle, which is an insert piece, is inserted into the support pin and conveyed in an inverted state. However, the hole into which the support pin is inserted cannot be formed as deep as the handle is formed, and the problem that the insert piece falls off the support pin due to vibration during transportation is likely to occur.

Further, in such an apparatus, compared with a conventional apparatus which has a preform transfer path only along one cycle process, an insert piece transfer path must be provided in parallel with the preform transfer path. The size of the device is increased because it is not obtained. Furthermore, since the insert piece is transported to a temperature control process which is not necessary originally, there is a drawback that a wasteful part is generated due to the device configuration.

Therefore, the present inventor has adopted a method of disposing the insert piece in the blow molding die independently of the preform. FIG. 7 shows an example of a method of supporting the insert piece when such a method is adopted.

In the figure, a groove 204 for inserting and supporting the insert piece 220 is provided facing the parting surface 202 of one split mold 200 of the blow molding die. The groove 204 has a bottom surface 206 and side surfaces 208a and 208b rising from the bottom surface 206. further,
Positioning pins 210 are vertically fixed from the bottom surface 206. On the other hand, the insert piece 220 needs to have a structure having a hole 222 through which the positioning pin 210 is inserted. In order to form this hole 222 by injection molding, an injection molding die (not shown) must be a split mold that can be opened and closed in the directions of arrows A and B in the figure. Then, the insert piece 220 is formed with a draft taper surface 226 that is inclined at the draft taper angle of the angle α with the parting line 224 on the side surface as a boundary.

When the insert piece 220 is arranged in the blow cavity type, the hole 222 of the insert piece 220 is inserted into the positioning pin 210. However, in order to facilitate this insertion operation, the hole 222 must be enlarged with a predetermined tolerance with respect to the diameter of the positioning pin 210, and thus this pin 220 is required.
And the engagement of the holes 222 alone, the insert piece 220
It is impossible to accurately position and hold the. In addition, a draft taper surface 226 is formed on the insert piece 220, and the draft taper surface 226 is a side surface 208a provided on the split mold 200 of the blow cavity type.
Alternatively, a gap is formed between it and 208b. For this reason,
It is highly possible that the insert piece 220 is arranged in an inclined state with respect to the positioning pin 210. If the preform is blow-molded with the insert piece 220 tilted, a defective bottle will be molded.

Another problem is how to insert the insert piece into the blow mold. Usually, the blow mold is composed of two split molds, and when a plurality of split molds are taken simultaneously, a plurality of blow cavities are present in each split mold. Therefore, the width of the blow mold is relatively long. When the insert piece is conveyed to such a blow mold, it is difficult to carry out the insert mold from above and below. That is, there is often a bottom mold drive mechanism below the blow mold, and above it there is a neck mold, blow core, stretch rod, etc. for biaxial stretch blow molding. Therefore, a plurality of insert pieces must be loaded laterally with the two split molds open. In such a case, since the member that holds the plurality of insert pieces is a cantilever, it is considered extremely difficult to reliably set the insert pieces at each insert position.

Therefore, an object of the present invention is to achieve high accuracy at the insert position even when inserting a part formed by sandwiching the parting line so that the surface having the punched taper faces the inner surface of the blow molding die. Positioning and holding is to provide a possible insert piece.

[0012]

[0013]

In the insert piece according to the present invention, a surface formed with a draft taper across a parting line is inserted so as to face an inner surface of a blow mold, and the insert piece is arranged in the blow mold. The blow-molded preform is an insert piece that engages with and is integrated with the blow-molded product, and is orthogonal to the parting line on the draft taper forming surface that abuts the inner surface of the blow-molding die. It is characterized in that ribs having the same height are formed along the direction.

[0014]

[0015]

[0016]

According to the insert piece according to the present invention, when the parting line is sandwiched and the surface having the draft taper is made to face the inner surface of the blow molding die, the insert piece is inserted.
Since the ribs having the same height are formed on the punched taper forming surface, there is almost no gap between the rib and the inner surface of the blow molding die, and the insert piece can be positioned and held with high accuracy. Since this rib is formed along the direction orthogonal to the parting line, it can be easily formed by two split molds which are driven to open in the opposite direction across the parting line.

Further , positioning pins are provided in the plurality of positioning holes.
Stable holding and positioning is possible by inserting and holding.
I can. Further, the side adjacent to the draft taper
By forming a concave portion for vacuum suction on the surface,
Performs reliable suction drive to the mold and inserts the insert piece.
It can be set securely.

[0018]

EXAMPLES Hereinafter, insert pieces to which the present invention is applied,
An embodiment of the insert blow molding die and the insert blow molding device will be specifically described with reference to the drawings.

First, an embodiment of the insert piece will be described with reference to FIG.

Insert piece 10 according to the present embodiment
Is configured as a handle that is engaged with the bottle. The insert piece 10 includes a grip portion 12 and first and second fixing leg portions 14 and 16 formed to project from both ends thereof.
And has a U shape as a whole. The grip portion 12 includes an inner surface 20 and a back surface 22 facing the inner surface 20.
And side surfaces 24a, 24b adjacent to the respective surfaces 20, 22
have. As shown in FIG. 1A, the two side surfaces 2
4a, 24b (side face 24b is not shown in the figure),
A concave portion is formed to make the thickness of the grip portion 12 substantially constant, and the concave portion at the central portion is formed as the vacuum suction concave portion 2
It is configured as 6. Further, on both sides of the vacuum suction concave portion 26, a circular hole 30 and an elongated hole 32 are formed so as to penetrate both side surfaces 24a and 24b. A first protrusion 34 that is bent upward is formed at the tip end position of the first fixing leg portion 14 that rises vertically from the grip portion 12. On the other hand, a second protrusion 36 bent downward is provided at the tip of the second fixing leg portion 16. When the bottle is formed by the biaxial stretch blow molding, the wall portions of the bolt resin wrap around both sides of the first and second protrusions 34, 36, so that the insert piece 10 is engaged and integrated with the bottle body. It will be.

Since the above-mentioned insert piece 10 has the vacuum suction concave portion 26, the circular hole 30, and the elongated hole 32, it is injection-molded using two split molds.
Therefore, as shown in FIGS. 1B and 1C, the inner surface 20
And a parting line 38 on the center line of the back surface 22.
Is formed. Then, on the inner surface 20, the draft taper forming surfaces 20 a and 22 b are formed on both sides of the parting line 38 such that the parting line 38 has the highest height on the line and lowers toward the left and right ends. Similarly, on the back surface 22 of the insert piece 10, on both sides of the parting line 38, the punched taper forming surface 22 is formed.
a and 22b are formed.

In this embodiment, ribs 40 having the same height as the parting line 38 are formed on the surfaces of the inner surface 20 and the back surface 22 along the direction orthogonal to the parting line 38 on each surface 20a. 20b respectively.
The ribs 40 may be formed at the same height as or higher than the parting line 38 and in a direction orthogonal to the parting line 38.

According to the insert piece 10 as described above, the surface facing the inner surface of the blow cavity mold (not shown), that is, the inner surface 20 and the back surface 22 of the blow cavity mold is a tapered surface, but the parting line 3 is formed.
8 and two ribs 40, 40 of the same height as this exist, when the blow molding die composed of two split molds is driven to be closed, the ribs are placed on the inner surface of the mold and on three lines. Since they come into contact with each other, the insert piece 10 can be stably held and housed in the mold.

FIG. 2 shows the insert piece 1 shown in FIG.
An example of the 0 insertion method is shown.

One split mold 52 of the blow cavity mold 50
In a, an insert groove having a bottom surface at a position lower than the parting surface 58 by a half of the thickness of the insert piece 10, and a side wall around the bottom surface is substantially along the outer shape of the insert piece 10. 60 is formed. The inner surface 20 faces one side surface 60b shown in the figure, and the back surface 22 faces the side surface (not shown) facing this. On the bottom surface 60a of the insert groove 60, two positioning pins 62, 62 are arranged over the parting surface 58 at the same pitch as the pitch between the circular holes 30 and the long holes 32 of the insert piece 10 facing each other. It is formed to project. Further, a vacuum suction passage 64 communicates with the bottom surface 60a.

On the other hand, a piece suction portion 70 for carrying the insert piece 10 is provided. The piece suction portion 70 has a groove 70 for accommodating the insert piece 10.
a, and two supporting pins 72, 72 are formed from this groove 70a.
Are formed to project. The support pin 72 is axially movable along the pin insertion hole 74a, and the flange 72a of the support pin 72 can abut on the stepped portion with the large-diameter cutout portion 74b communicating with the pin insertion hole 74a. Has become. The coil spring 76 is provided in the cutout portion 74b.
The support pin 72 is constantly discharged and biased by the biasing force of the spring 76. Further, a vacuum suction passage 78 that is opened in the groove 70a of the piece suction portion 70 is formed.

When the insert piece 10 is conveyed, FIG.
As shown in (A), the insert piece 10 is housed in the groove 70 a of the piece suction unit 70 and conveyed. At this time, in the circular hole 30 and the long hole 32 of the insert piece 10,
Two support pins 72, 7 protruding from the piece suction portion 70
By inserting 2 and vacuuming through the vacuum suction passage 78, the insert piece 10 is securely sucked and held at a predetermined position of the piece suction portion 70. Two split molds 52a of the blow cavity mold 50,
After opening 52b, the piece suction part 70 is horizontally moved from the lateral direction and stopped at a position corresponding to the insert groove of the split mold 52a. After that, the piece suction part 70 is divided into 5 pieces.
Move toward 2a.

FIG. 2B shows a state in which the insert piece 10 is delivered from the piece suction portion 70 side to the split mold 52a side. In this state, the two positioning pins 62, 62 on the split mold 52a side are inserted into the circular hole 30 and the long hole 32 of the insert piece 10. The tips of the positioning pins 62, 62 come into contact with the tips of the support pins 72, 72, whereby the support pins 72, 72 move backward against the biasing force of the coil springs 76, 76, and the positioning pins 62, 72 The positioning operation by 62 is realized. After storing the insert piece 10 as described above, the piece suction portion 70
The suction on the side is released and the suction drive on the split die 52a side is started, whereby the insert piece 10 is suction-held on the split die 52a side.

Here, the side surface 24 of the insert piece 10
By providing the vacuum suction recesses 26, 26 in a and 24b, reliable suction drive by the split mold 52a or the piece suction unit 70 becomes possible. If such a concave portion 26 is not provided, when a slight gap is created between the side surfaces 24a, 24b of the insert piece 10 and the suction surface, air leaks from the gap and reliable suction drive cannot be performed. Is.

Further, the inner surface 2 of the insert piece 10
By providing the ribs 40 described above on the 0 and the back surface 22,
The side surface 60b of the insert groove 60 and the opposite side surface thereof come into line contact with each other at three points, and the hole 3
Even if there is a tolerance between the pins 0, 32 and the pin 62, this three-line contact enables the insert piece 10 to be accurately stored and held without tilting.

Since this operation can also be realized on the suction section 70 side, the positional accuracy at the time of delivery can be improved.

FIG. 3 shows an arrangement of a plurality of blow cavities in the blow cavity mold 50. In this embodiment, there are four blow cavities, and two adjacent blow cavities are arranged in line symmetry so that the insert grooves 60 are close to each other. In FIG. 3, the blow cavity 54 is formed substantially along the outer shape of the finished bottle, and the neck mold notch 56 on the upper end side is a neck mold for conveying the preform to this blow molding station. Functions as an escape area. The surfaces other than the blow cavity 54, the neck mold notch 56 and the insert groove 60 are all configured as a parting surface 58.

FIG. 4 shows a state in which the insert device 80 is arranged between the two split molds 52a and 52b constituting the blow cavity mold 50 in the open condition.
FIG. 5 shows an overall layout of a hot parison type injection stretch blow device including the insert device 80. In FIG. 5, the injection stretch blow molding apparatus has an injection molding stage 120, a temperature control stage 130, a blow molding stage 140 and a take-out stage 150, and a neck mold 11 for holding a neck portion of a preform or a bottle.
0 can be cycled to each stage. The layout of each stage, such as the type without the temperature control stage 120, can be freely changed, and a cold parison type device may be used.

In both types of devices, as shown in FIGS. 4 and 5, the insert device 80 has an arrow that is in the same direction as the mold opening / closing direction of the two split molds 52a, 52b in the blow molding stage 140. Forward / backward drive is possible in each of the A direction and the arrow B direction orthogonal thereto. The two piece suction portions 70, 70 are provided on the cantilever beam 82 which is driven to move back and forth in the A and B directions. In this embodiment, the two insert pieces 10, 10 can be suction-held in one piece suction portion 70.

The holding pitch of the two insert pieces 10, 10 sucked and held by the one piece suction portion 70 is such that the two adjacent blow cavities 5 shown in FIG.
It is the same as the arrangement pitch of the positioning pins 62, 62 in 4, 54. The arrangement pitch of the two insert pieces 10, 10 in one piece suction portion 70 is P ₁
And the arrangement pitch of the two outermost insert pieces 10, 10 in the two suction portions 70, 70 is P.
_{Assume 2} .

FIG. 6 shows a comparative example of the embodiment shown in FIG. The four blow cavities 92 formed in the split mold 90 shown in FIG. 6 are formed in the same direction, and accordingly, the insert groove 94 is present on the right side of each blow cavity 92. The insert device 100 for transporting the four insert pieces 10 to the split mold 90 has four cantilever beams 102 on which four piece suction portions 104 having an equal pitch P ₃ are arranged. Therefore, the two farthest two piece suction units 104,
The pitch between 104 is P ₄ = 3 × P ₃ .

In the embodiment shown in FIG. 4, the pitch P ₁ between the adjacent pieces 10, 10 is the pitch P ₃ in FIG.
The size can be made considerably smaller than the above, and as a result, a structure for holding the two pieces 10, 10 in one piece suction portion 70 can be adopted. Moreover, the pitch P ₂ between the two furthest insert pieces 10, 10 in the embodiment shown in FIG. 4 can also be made shorter than the corresponding pitch P ₄ in the comparative example shown in FIG. Cantilever 82 or 102
In the insert device of the type using, even when the rigidity is considerably high, the free end portion is bent, so that it is difficult to insert the insert piece on the free end side into the insert groove accurately. However, by making the pitches P ₁ and P ₂ shorter as in the device shown in FIG. 4, it is possible to realize an insert with higher accuracy than in the case shown in FIG. 6 which is a comparative example. Moreover, by shortening the pitches P ₁ and P ₂ , it is possible to further increase the mechanical accuracy during die processing, which also contributes to accurate insert operation of the insert piece 10.

The present invention is not limited to the above embodiment, but various modifications can be made within the scope of the present invention.

Although each of the above embodiments has been described by assuming a handle as an insert piece, it is needless to say that it can be applied to various other insert pieces that are engaged with and integrated with a blow molded product during blow molding.

Further, the arrangement of the blow cavities in the blow cavity mold shown in FIG. 3 and the construction of the insert blow molding apparatus shown in FIG. 4 are as shown in FIG.
It is more preferred to use i Nsatopisu 10,
Even for the insert piece 10 that does not necessarily have the rib 40, an accurate insert operation can be ensured.

[0041]

As described above, according to the insert piece of the present invention, when the draft taper forming surface is arranged so as to face the inner surface of the blow molding die, a parting line is formed on the draft taper forming surface. By providing the ribs of the same height along the direction orthogonal to each other, it is possible to eliminate the gap between the inner surface and the inner surface facing each other, and to accurately position and insert the insert piece into the blow mold.

Further , positioning pins are provided in the plurality of positioning holes.
Stable holding and positioning is possible by inserting and holding.
I can. Further, the side adjacent to the draft taper
By forming a concave portion for vacuum suction on the surface,
Performs reliable suction drive to the mold and inserts the insert piece.
It can be set securely.

[Brief description of drawings]

1A to 1D are respectively a front view, a left side view, a right side view and I of an insert piece according to the present invention.
It is an expanded sectional view of the I line.

FIG. 2A and FIG. 2B are operation explanatory views for explaining the insert operation of the insert piece.

FIG. 3 is a plan view of a blow cavity split mold in which adjacent blow cavities are arranged in line symmetry.

FIG. 4 is a schematic cross-sectional view of the entire apparatus for inserting a plurality of insert pieces simultaneously taken into a blow cavity mold composed of the split mold shown in FIG.

FIG. 5 is a plan view showing the layout of the entire injection stretch blow molding apparatus including the insert device.

6 is a schematic cross-sectional view showing a comparative example of the apparatus of the embodiment shown in FIG.

FIG. 7 is a schematic explanatory view for explaining an adverse effect when the punched taper forming surface is brought into contact with the inner wall of the cavity and is inserted.

[Explanation of symbols]

10 Insert Pieces 20a, 20b, 22a, 22b Die Taper Forming Surfaces 26 Vacuum Suction Recesses 30, 32 Holes 38 Parting Lines 40 Ribs 50 Blow Cavity Molds 52a, 52b Split Molds 54 Blow Cavities 60 Insert Grooves 62 Positioning Pins 64, 78 Vacuum suction passage 70 Piece suction part 72 Support pin 80 Insert device 82 Cantilever beam
NS009501

Claims (3)

(57) [Claims] 1. A blowing tape is formed by sandwiching a parting line so as to face the inner surface of a blow molding die, and the preform arranged in the blow molding die is blow-molded to form a blow mold. An insert piece that engages with a molded product and is integrated, wherein the draft taper forming surface facing the inner surface of the blow molding die,
An insert piece, wherein ribs having the same height are formed along a direction orthogonal to the parting line. 2. The plurality of positioning holes according to claim 1, wherein a plurality of positioning holes are formed on a side surface adjacent to the draft taper forming surface, and the positioning holes can be inserted into a plurality of positioning pins protruding from an inner surface of the blow molding die. And insert piece. 3. The insert piece according to claim 1, wherein a concave portion for vacuum suction is formed on a side surface adjacent to the draft taper forming surface.