JPH02175224A - Injection blow molding device - Google Patents

Abstract

PURPOSE:To enable a reliable actuation free from malactuation, by a method wherein a flange part of a bushing provided slidably on a core die is pressed against an actuation groove according to mold clamping, an air blow-off outlet of a core is clogged with the bushing at the time of molding of parison and the same is released at the time of blow molding. CONSTITUTION:At the time of molding of parison, an air blow-off outlet 28 of a core 21 is closed with a slide bushing 24 of a core die 3 in accordance with mold clamping of a cavity die 1 for the molding of the parison. Then after the core die 3 is turned to a blow molding cavity die 2, the slide bushing 24 is actuated by mold clamping force and the air blow-off outlet 28 is released in accordance with the mold clamping of the blow molding cavity die 2. Since the air blow-off outlet 28 is opened or closed in alignment with a mold clamping actuation of the dies 1, 2 like this, reliable actuation free from malactuation becomes possible and inferior molding at the time of blow molding can be reduced.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Field of Application) The present invention relates to an injection blow molding apparatus for producing a hollow molded product made of a thermoplastic synthetic resin, a thermoplastic wlastomer resin. It is something.

(Prior art) Index blow molding was developed primarily for the purpose of container production, and the general injection blow molding equipment used therefor is an index blow molding machine with a V for parison molding.
A Yavidi mold, a blow molding mold, and a core mold that rotates between these two molds are installed, and in parison molding, the core mold is For molding - 1-V It is wrapped in a metal hem, the mold is closed and the parison is injection molded, and then the molded parison is
It is known that the first core mold is rotated to the ↑ Yaviti mold for blow molding, the mold is closed, air is blown between the core of the core mold and the parison, and the parison is molded into the product shape.

By the way, in the injection blow molding apparatus described above, the air outlet for blowing air between the core and the parison during blow molding is generally arranged in the core mold section.

As an example of this, an M4 structure is used in which a gap 1, ie, a slit, is provided in the core mold part to allow air to pass through but not to flow into the 8I fat 1 in a normally open manner.

The slit IJ that forms the air outlet is generally provided in the core of the core mold. However, this core often requires a temperature adjustment R structure to keep the parison resin temperature constant during blow molding, so the slitting process is complicated and requires high AI viscosity. Also,
Since the slit 1 cannot be enlarged, the air blown out from the slit ω is not sufficient, and the shape of the molded product is limited. Furthermore, the slit that forms the air outlet that is always open (well, since resin inflow during parison molding cannot be completely prevented, it may become clogged due to this resin inflow, or it may be blown in by 63x4 blockage due to dust, oil, etc.) This causes molding defects.

As another example, a structure is adopted in which the core mold is provided with a blowout D n bM that is open only during blow molding and closed during parison molding. As a specific example, there is one in which the core is actuated by an air cylinder or the like to open the air outlet (111). However, such an outlet mechanism, combined with the core temperature control mechanism described above, requires a complicated structure. In addition, a core operation control device is required to operate the core at the same time as the mold is closed during blow molding.In addition, when molding a cylindrical molded product with openings at both ends, the core and the blow molding The mold fit C with the tee mold was difficult, leading to molding defects due to malfunction.

('R, the problem that Akira is trying to solve) As mentioned above, the sleeve l~ that forms the air outlet in the core.
Conventional injection blow molding equipment that is installed when the mold is normally open does not allow sufficient air to be blown out, which limits the shape of the molded product, and also causes defects in the blow molding due to clogging of the slits with resin, etc. There were other problems. In addition, conventional injection blow molding equipment, in which the core is actuated by an air cylinder or the like to open and close the air outlet, has a complex structure, is octavalent, and is prone to molding defects due to malfunction. there were.

The present invention has been made in view of the above-mentioned problems, and aims to provide an injection blow molding apparatus which has a structure in a cylinder, can be made at low cost, has sufficient air blowing interval, and is less likely to cause molding defects. It has a purpose.

[Structure of the invention]

(Means for Solving the Problems) In order to achieve the above object, the present invention provides a cavity mold 1 for parison molding, a cavity mold 2 for blow molding,
Core mold 3 moving between these two cavity molds 1.2
The parison molding cavity mold 1 including the core mold 3 is closed and the parison 61 is injection molded, and the core mold 3 with the parison 61 attached is inserted into the blow molding cavity mold 1. In an injection blow molding device, the parison 61 is moved into a mold 2, the mold is closed, and air is blown between the core mold 3 and the parison 61 through an air outlet 28 to mold the parison 61 into a product shape. The core 21 of the core mold 3 is provided with the air suita port 28, and
A 21 of the core mold 3 and an outer cylinder 22 which is installed on the outer circumferential side of the core 21 and forms the opening at one end of the molded product 63.
23, for example, a sleeve-shaped bushing 24 having a flange portion 33 protruding from the outer station 22, 23 and opening the air blowing hole 28 is provided so as to be slidable in the axial direction.
Roughly, to the above-mentioned parison molding -1 Yavitei gold 41,
With the mold closing, the flange portion 33 of the bushing 24
Press and release the air outlet 28 by pressing this J-button 24.
(operation for blocking) Old 51 was installed, and on the other hand, the above-mentioned blow molding accessory fl! 2, as the mold closes, the flange portion 33 of the bushing 24 is pressed in the opposite direction to open the air outlet 28.
H56 is provided.

(Function) In the injection blow molding machine d of the present invention, first, in order to perform parison molding, 13 is included in 17-karat gold and the cavity mold 1 for molding the parison is closed.

With this mold closing, 1 m outside the bushing 24 of the core mold 3
22. The flange part 33 protruding from 23 is for parison forming - 111 Hey all "! 1 J,
The bushing 24 slides in one axial direction between the core 21 of the core mold 3 and the outer cylinders 22 and 23, for example, and closes the air outlet 28 of ]721. Then, a parison 61) is molded. At this time, Bush 2
Since the air outlet 28 of the core 21 is blocked by the air outlet 28 of the core 21, the air outlet 2
8 is prevented from flowing into the resin. Next, in order to perform blow molding, the parison molding cavity mold 1 is spaced one space apart, and the core mold 3 with the molded parison 61 attached thereto is moved to the blow molding mold 1 and the Tobiai mold 2. The mold of '12' is closed onto this 21-bit mold for blow molding. Along with this desire 1'A, the flange part 33 of the bushing 24 of the core mold 3 is pressed by the opening part 1ln5G of the blow molding mold 2, and the bushing 24 slides in the opposite direction. Core 21
The air outlet 28 of is opened. Then, air is blown between A 21 and the parison 61 through the air outlet 28 to form the parison 61 into a product shape. Thus, cavity molds for parison molding and blow molding 1.
2, the bushing 24 is activated and the air outlet 28 opens only during blow molding to complete parison molding.
'f M i close. Note that the outer cylinder 22 of the core mold 3.
23 forms one end of the molded product 63.

(Example) Hereinafter, an example of the injection blow molding apparatus of the present invention will be described in detail with reference to the drawings.

The apparatus of this embodiment is for molding a cylindrical molded product (bellows) with openings at both ends and having a bellows-shaped part that can be expanded and filled. This cylindrical molded product number is suitable for the engineering machinery field.
3, which is used, for example, as a cover for a universal joint.

As shown in FIG. 1, which is a side view of the injection blow molding apparatus, this DI injection blow molding apparatus includes a parison molding cavity mold 1, a blow molding cavity mold 2, and a cavity mold 2 for blow molding. A pair of core molds 3 for parison molding that rotate and move the molds 1.2 and 21A rotation drive device (not shown) that rotates the core molds 3. The core support base 4 is connected to the core support base 4 and rotates horizontally.

As shown in FIG. 2, which is a vertical cross-sectional view of the main parts of the parison molding cavity mold 1 and the core mold 3,
The -1'-P cavity metal τ11 for parison molding consists of a movable cavity member 6 for parison molding which can be moved horizontally towards and away from it, and a fixed cavity N5 material 7 for parison molding. The Yaviai parts 6.7 are each mounted on a mounting plate 8.9 of the injection blow molding machine. Further, a heater 1 is provided at the lower part of the fixed cavity member 7.
04j: A hot runner 11 is marked with an installation number, and a resin inlet 12 is installed at the tip of this hot runner 11.
is formed.

In addition, as shown in FIG. 3, which is a vertical cross-sectional view of essential parts of the V cavity mold 2 for blow molding and the core mold 3, the cavity mold 2 for blow molding [... It consists of a freely movable side for blow molding ~1t biddy member 16 and a fixed side for blow molding 1 Yaviai member 17, and these t
, and the cavity members 16 and 17 are respectively attached to the receptacle plate 18 of the injection blow molding machine. It is attached to IQ.

Further, the core mold 3 has the core support 1. ! A shift-shaped core 21 fixedly connected to the lower side of the i-stand 4, a core holding outer cylinder 22 including the upper end of this core 21 and fixedly connected to the core support stand 4, and this core. Outside of holding i'!
122, and a sleeve-shaped slide button supported slidably in the axial direction between the outer cylinders 22, 23 and the core 21. 24. Note that the core mold 3 is movable in the radial direction with respect to the core support base 4.

Next, the structure near this slide bush 2441 will be explained based on FIG. In addition, Fig. 4) is the key 1 for parison molding. The bitty mold 1 side is shown, and FIG. 4(2) shows the cavity mold 2 side for blow molding. Further, FIG. 5 is a sectional view taken along the line v--■ in FIG. 4.

Inside the core 21, a temperature regulating medium passage 26 is formed, through which a cooling or heating medium such as water or oil flows, in order to maintain the core 21 at a constant degree of lagoon.

In addition, 1. [On the outer circumferential surface of the lower end of the core 21, there is an annular air circulation groove 27, and an annular air circulation groove 27 located below the air circulation groove 21 and facing the lower end of the opening diameter molded outer cylinder 23. An annular air outlet 28 and a plurality of air circulation grooves 29 extending in the axial direction communicating the annular air outlet 27 and the air outlet 28 are formed.

Further, between the outer circumferential surface of the upper end of the core 21 and the inner circumferential surface of the lower part of the core holding outer cylinder 22 and the opening diameter forming outer cylinder 23, the upper end is connected to the annular air flow 7'fA27. A facing gap 31 is formed, into which the cylindrical portion 32 of the slide pusher 24 is fitted airtightly and slidably in the axial direction and in the vertical direction.

Further, a pair of left and right flanges 33 are formed at the axially intermediate portion of the cylindrical portion 32 of the bushing 24, and the tip end portion 34 of the flange portion 33 has an inclined top surface and a bottom surface 35.
It has a tapered shape of 36.

On the other hand, the core holding outer n22 and the opening diameter forming outer cylinder 23 are connected together, and the core 21 and the cavity member 5. 7.16.Cylinder part 41 for positioning with 17
．． 42 and a pair of left and right flange portions 43 and 44, respectively. Then, the flange portion 33 of the slide bushing 24 is inserted into the through hole 45 formed between the flange portion 43 at the bottom of the core holding outer cylinder 22 and the flange portion 44 at the bottom of the aperture molding outer f523. The distal end portion 34 of the flange portion 33 protrudes outward from the inner and outer cylinders 22 and 23. The width of the through hole 45 in the vertical direction defines the slidability of the slide pusher 124, that is, the operating range. The air outlet 28 is opened when the air outlet 28 is closed and turned to the maximum.

Furthermore, the above-mentioned [1■ gap 31
An air inlet 46 communicating with the upper end is formed.

Further, a mold portion 47 is formed at the lower end of the outer circumferential surface of the opening-diameter molded outer cylinder 23 .

In addition, both sides of the Yavidei mold 1 for parison molding, the upper part of which is removably joined to the outer circumferential surface of the self-made 522.23: 1. A closed IJJ fi 51 is formed to which the tip end portion 34 of the flange portion 33 of the slide bush 24 labeled Ll and L is engaged. This operating temperature for closing 51 has an upper surface and a lower surface each having an inclined surface 52.53 inclined at the same angle as the inclined r1 surface 35.36 of the flange PIS33. When the parison mold 4:t-bitty mold 1 including the core mold 3 is closed, an upper slope 35 is formed on the upper slope 35 of the flange portion 33 of the slide bush 24 that has been lowered. 52 is pressed.

On the other hand, the flange portion 33 is attached to the opposing surfaces of both cavity members 16.17 of the blow molding key mold 2, to which the external surfaces of the inner and outer cylinders 22.23 are removably joined to the upper part.
An open rice field JiR 56 is formed in which the tip end portion 34 of the rice pad 56 is engaged. These opening operation grooves 56 have the same shape as the above-mentioned closed Tasaku IJ + Man s1, and have sloped surfaces 57.58 on the upper and lower surfaces, but are more equivalent to the operation ff1m of the slide pusher 124 than this closing operation groove 51. It is shifted upward by the amount that it is. In this way, when the one-tobity mold 2 for blow molding is closed including the core mold 3,
A lower inclined surface 58 is pressed against the lower inclined surface 36 of the flange portion 33, and the slide bush 24 is raised.

J3, above) In the air outlet mechanism described above, the relationship between the operating port m of the slide bush 24 and the closing d of the air outlet 28 is m>d, where m is approximately 3 m and d is approximately 1 to 2 m. The degree is appropriate. Further, the relationship between the vertical width W of the sloped surface 35.3f3 of the flange portion 33 of the slide bushing 24 and the operation in of the slide bushing 24 is w>m, and the slope angle θ of the sloped surface 35.36 is 25 to 30' is appropriate.

Next, injection blow molding using the above-mentioned equipment will be explained.

First, parison molding will be explained. As shown in FIG. 2, the core mold 3 is enclosed and the parison molding cavity surface 1 is closed. In this state, as shown in FIG. 4 (FIG. 1), the upper inclined surface 35 of the flange portion 33 of the slide pusher 24 serves to block both cavity members 6 and 7 of the cavity mold 1 for parison molding. ! The slide bush 24 is held in the lowest position by being pressed by the opposing upper inclined surface 52 of the jJi 1151. therefore,
This slide bush 24 is the air outlet 28 of
The closed state is maintained.

Then, the thermoplastic synthetic resin or thermoplastic elastomer resin (hereinafter collectively referred to simply as resin) is mixed and melted by the injection molding cylinder (not shown) of the injection blow molding machine, and the plasticized resin is A hot runner 11 is placed in a cavity space 60 formed by the movable cavity member 6 for parison molding, the fixed cavity member 7, the core 21, and the outer cylinder 23 for molding the opening diameter.
81 fat is injected from the inlet 12 to form a parison 61.

At this time, since the inclined surface 52 of the closing operation groove 51 of the cavity members 6 and 7 is in contact with the flange portion 33 of the slide bush 24 from the direction opposite to the direction in which the injection pressure of IjA fat is applied, this injection pressure Slide bushing 24
remains in the lowered position, and the air outlet 28 remains closed. Therefore, the resin is prevented from flowing into the air outlet 28.

After the parison θ1 is molded, the cavity members 6 and 7 of the parison molding mold 1 are opened. In addition, when opening the mold of this muyabitei member 6.7,
The core mold 3 is placed between the movable cavity member 6 and the stationary cavity member 7 with the parison 61 attached thereto, so that the core mold 3 is placed between the movable cavity member 6 and the fixed cavity member 7 by a device (not shown) consisting of a rack gear V and a pinion gear cap. is moved in the mold opening/closing direction.

Next, the core mold 3 with the parison 61 attached is moved to the core support base 4 by a core rotating device connected to the core support base 4.
At the same time, the mold is rotated and moved to an intermediate position between the movable cavity member 16 and the fixed cavity member 17 of the blow molding cavity mold 2 which is opened.

Thereafter, the core mold 3 is included and the blow molding mold 2 is closed. Along with this mold closing, Fig. 4 (2)
As shown in FIG.
The lower inclined surface 58 of the opening operation groove 56 of both cavity members 16 and 17 of the blow molding cavity mold 2 is pressed from below by the lower inclined surface 36 of the blow molding mold 2, and the slide button which had been lowered is pressed from below. The shoe 24 is gradually lifted against the load. In addition, the two-dot chain line in FIG. 4 O) indicates a state in the middle of mold closing. When the mold is completed, the slide bush 24 is in the highest position,
] The air outlet 28 of the core 1 is opened, and a space 62 is created between the air outlet 28 and the inner surface of the parison 61.

Compressed air is supplied from an air source (not shown).
The air is blown out from the space 62 between the slide bush 24 and the parison 61 through the air inlet 46 of the core holding outer cylinder 22, the air circulation grooves 27 and 29 of the core 21, and the air outlet 28, and is blown out from the space 62 between the slide bush 24 and the parison 61. It is blown between the parison 61 and the parison 61. As a result, the parison 61 expands and is peeled off from the core 21, and the cavity surfaces 16a of the inner surfaces of the movable cavity member 16 and the fixed cavity member 17 for blow molding.

17a and molded into a product shape. That is, a bellows-shaped hollow molded product 63 is molded.

Note that the shape of the opening at the upper end of the hollow molded product 63 formed by the open diameter molded outer cylinder 23 does not change due to the above-described blow molding.

After a predetermined period of time has elapsed from the completion of this blow molding, the blow molding cavity mold 2 is opened, and the formed hollow molded product 63 is released by blowing air from the air blowing port 28.
Or a device for taking out the molded product from the outside (not shown)
The core is removed from the core mold 3 and taken out.

The above begins with the molding of parison 61, and this parison 6
1 is blow-molded to produce one hollow molded product 63. However, after the mold is opened and the parison 61
The core mold 3 with attached is rotated by the core rotation [1a] connected to the core support stand 4, and the blow molding movable side 1-t.
171 part 4A16 and the fixed side 4-way part 17 The removed core gold of the molded product 63 between the member 7!
X'+ 3 is also rotated between the movable side Y cevity member 6 and the fixed side -1 cevity member 7 for parison forming. While blow molding is being carried out, resin is injected from the injection molding cylinder in the independent mold 1, and parison molding is carried out. The forming process is always repeated for 4f lines.

J3, the apparatus of the embodiment shown in FIG. 1 was one in which a pair of molds 1 for forming a parison and a mold 2 for blow molding were installed together. If necessary, you can increase productivity by running several of the same combinations in parallel.

By the way, in the above-mentioned embodiment, the slide bush 24 is lowered to close the air outlet 28 except when the cavity mold 2 for blow molding is closed.

However, for example, when the core 21 is arranged horizontally and the slide bush 24 slides horizontally, as the mold 1 for parison molding is closed, the cavity 1 part 6.7 0'l occlusion operation full 51 sloped surface 5
2 is the inclined surface 3 of the 7 flange portion 33 of the slide bush 24
5 and slide the slide bush 24 on the outer periphery of the core 21 toward the air outlet 28 .
8 will be closed. Then, when the mold closing is completed, the air outlet 28 is completely closed.

According to the above configuration, the following effects are achieved in injection blow molding of the hollow molded product 63.

As described above, during parison molding, the air outlet 28 of the core 21 is closed by the slide bush 24 of the core mold 3 as the parison molding cavity mold 1 is closed, and then the core mold 3 is closed. Blow molding cavity mold 2
When the blow molding cavity mold 2 is closed, the slide bush 24 is actuated by the mold closing force and the air outlet 28 is opened, and the air outlet 28 and the parison 61 are closed. A space 62 is obtained between the bolts.

1, the air outlet 2 is opened in synchronization with the mold closing operation of J3 for parison molding and 4-Yabity Kinashi 1 and 2 for blow molding.
8 is opened and closed, this air outlet 28 is made by blow molding.
Since only 4 is open and the parison is formed, and 1 is closed, there is no need for a structure in which the core 21 is grown in the axial direction, etc.
II device No other air outlet opening/closing 4+1 (Company) device is required, but with a simple structure, it is possible to realize the air outlet mechanism at low cost that synchronizes with mold opening/closing, and there is no malfunction. Enables reliable operation and reduces molding defects during blow molding.

Further, since the air outlet 28 is closed in the parison molding 1, it is possible to install the air outlet 28 of a size necessary and sufficient for blow molding. Therefore, it is also possible to manufacture complex blow molded products.

Moreover, since the air outlet 28 is completely and firmly closed 111 by closing the parison molding cavity mold 1 during parison molding, resin can be prevented from flowing into the air outlet 28.

In particular, a cylindrical molded product 63 with openings at both ends having a bellows-shaped portion.
(Bellows) molding 1, parison 61 was molded, core gold ¥ 1 with molded parison 61 still attached!
3 is rotated and blow molded, at the upper and lower ends of the parison 61] A 21 is formed (parison molded in the gap between the outer diameter molded outer cylinder 23 and the 1-today member 16 and 17). By positioning the product without any gaps, the outer and inner diameters of the upper and lower ends of the part are reliably regulated by the mold 23. Therefore, the openings of both ends are fixed to other separate parts such as the seat 71- In addition to the usefulness of injection blow molding, the bellows to be blow molded Due to the above-mentioned sufficient air blowing, the shape of the part 16.
, 17a, and the usefulness of injection blow molding can be further enhanced.

J3, the apparatus of the present invention is a cylindrical molded product 6 with a length of 1"i between both ends of the expandable bellows-shaped part shown in the above embodiment.
In addition to 3, it is possible to manufacture hollow molded products of any shape using ordinary containers. In addition, the materials for 8Arfi to be molded include polyethylene, polypropylene, polyvinyl chloride, polyethylene terephthalate, borisdylene,
Thermoplastic synthetic resins such as polyamide, polyolefins,
Polyurethane type, poly 1 stel type, polyvinyl chloride type,
Examples include polyamide-based thermoplastic elastomer resins.

C Effects of the Invention] According to the present invention, the flange portion of the bushing slidably provided on the core mold is opened into the operating groove of the parison molding phase kit mold or the cavity mold for blow molding. Since the air outlet in the core is opened during parison molding and opened again during blow molding, there is no need for other air outlet closure devices, resulting in a simple structure. The opening and opening of the air outlet in synchronization with the opening of the mold can be realized at low cost, allowing reliable operation without malfunction, and reducing molding defects during blow molding. In addition, since the air outlet can provide sufficient air blowing capacity, it is possible to manufacture complex blow molded products.

Furthermore, it is possible to prevent resin, etc. from flowing into the GJ and air outlet during parison molding, thereby preventing defects in blow molding.

[Brief explanation of the drawing]

Figure 1 [91] A side view showing an embodiment of (g) Blow molding 'A11 of the present invention, Figure 2 is a side view of the parison molding phase cavity edge and core mold part of the mold shown in Figure 1. 1 Vertical cross-sectional view of the main part when the mold is closed, Figure 3 A vertical cross-section of the main part of the blow molding key 1F bit 14J3 of the apparatus shown in Fig. 1 and the core mold part when the mold is opened. Figure 4 is the opening/closing operation of the air outlet of the mold shown in Figure 1.
A sectional view showing the main parts from the side, (c) is for parison molding 1
” - Indicates bidet mold side (Ll) 1. , i shows the side of the cavity mold for blow molding, and Figure 5 shows ■ in Figure 4.
−■ It is a sectional view. 1..Cavity mold for parison molding, 2..4-Tobitity mold for blow molding, 3..Core mold, 21..Core, 22.23..Outer cylinder, 24..Push l, 28. ...Air outlet, 33..Flange part, 51.. December 28, 1988 Nikko Akina Shirai Tadayo Doyama Morimasa Special N Applicant Stone Iron Works Co., Ltd. Mitsubishi [Nzanto Kasei Co., Ltd. Kaba Kaba Sawazawa'N@ 11 ~ Atsushi 9 SH

Claims (1)

[Claims] (1) Comprising a cavity mold for parison molding, a cavity mold for blow molding, and a core mold that moves between these two cavity molds, the above-mentioned cavity mold for parison molding includes this core mold. After the mold is closed and a parison is injection molded, the core mold with this parison attached is moved to the blow molding cavity mold, the mold is closed, and an air outlet is created between the core of the core mold and the parison. In an injection blow molding device for molding the parison into a product shape by blowing air through the core, the air outlet is provided in the core of the core mold, and the air outlet is provided in the core of the core mold and on the outer peripheral side of this core for molding. A bush for opening and closing the air outlet, which has a flange portion protruding from the outer cylinder, is provided between the outer cylinder and the outer cylinder forming an opening at one end of the product, and is slidable in the axial direction, The mold is provided with a closing operation groove that presses the flange of the bushing to close the air outlet with the bushing when the mold is closed; An injection blow molding apparatus characterized in that an opening operation groove is provided for pressing the flange portion of the bush in a reverse direction to open the air outlet.