JP2000085000A - Blow molding apparatus and method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To finish even a deep draw product made complicated in shape by increasing the product length to a double wall distance to a desired final molded product without allowing a parison to reach a puncture in a molding process. SOLUTION: In a blow molding apparatus equipped with a die 9 extruding a parison 10 and a pair of split molds 1, 2 arranged so as to grasp the parison 10 under the die 9 and openable and closable in a horizontal direction, the frame body 3 surrounding the outer periphery of the side surface of one split mold 1, the upper plate body 4 attached in freely slidable manner in the opening and closing direction of the split mold in opposed relation to the upper front end surface 31 of the frame body 3 on the upper surface of the other split mold 2 and coming into contact with the upper front end surface 31 by mold closing and the lower plate body 5 attached in a freely slidable manner in the opening and closing direction of the split mold in opposed relation to the lower front end surface 32 of the frame body 3 on the under surface of the other split mold 2 are provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a blow molding apparatus and a blow molding method useful for producing a deep drawn product or the like.

[0002]

2. Description of the Related Art Various products are produced by blow molding.
No. 23 and Japanese Patent Application Laid-Open No. 7-214649 have been proposed, and the range of shapes that can be manufactured has been widened.

[0003]

However, when attempting to produce a deep drawing product with a flat double wall structure, the above-mentioned production method sometimes causes a parison to be punctured during the molding process and cannot be molded. In the case of forming a deep drawn product, according to the above-mentioned Japanese Patent Publication No. 6-55423, blow molding proceeds while the outer frame pinches the parison at the same timing and the sealed parison is completely enclosed by the outer frame. Therefore, there is no escape place for the pre-blow air, and the puncture occurs in the cavity. When the split mold closed, the pre-blown air sought refuge and a portion of the parison, for example, entered the gap between the outer frame and the split mold, causing puncture. In particular, in the case of a large deep drawn product such as an instrument panel, if the product length L2 with respect to the distance L1 between the double walls is large and the complex shape has irregularities in the short direction as shown in FIG. Was easy to invite.

The present invention solves the above-mentioned problem. Even if the product is a deep drawn product having a complicated shape having irregularities in the short direction due to a large product length with respect to the distance between the double walls, a parison is required during the molding process. It is an object of the present invention to provide a blow molding apparatus and a blow molding method capable of finishing a desired final molded product without causing puncturing.

[0005]

In order to achieve the above object,
The gist of the present invention according to claim 1 is a blow molding apparatus including a die for extruding a parison, and a pair of split dies that are arranged so as to be able to sandwich the parison below the die and that can be opened and closed in a horizontal direction. A frame body (3) slidably mounted around the outer periphery of the side surface of one of the split dies, and an opening / closing direction of the split die facing the upper front end surface of the frame on the upper surface of the other split die. The upper plate body (4) which is slidably mounted on the upper mold body and which comes into contact with the upper front end face when the mold is closed, and the lower surface of the other split mold,
A lower plate body (5) slidably mounted in the opening and closing direction of the split mold facing the lower front end face of the frame body and abutting on the lower front end face when the mold is closed. Blow molding equipment. The gist of the present invention described in claim 2 is that, using the blow molding device, the lower end of the parison is welded to form a closed portion and pre-blow is performed, and the closed portion passes between the frame and the lower plate. Drop the parison to the position
Next, the split mold is advanced in the closing direction, the frame and the upper plate are closed, and the upper end of the parison is sealed to form a sealed parison,
Subsequently, the frame body and the lower plate body are closed to form another closed portion above the closed portion, and thereafter, the pair of split dies are closed, and the cut-off portions of the split dies are brought into contact with each other so that the excess A blow molding method characterized by performing a main blow into a sealed parison after removing the parison.

According to the first and second aspects of the present invention, when a frame, an upper plate and a lower plate which can be moved separately from the split mold are provided, the frame and the upper plate, and the frame and the lower plate are provided. , Frame body and both sides of female mold, bite-cut parts, etc.
Because the closing timing of the open part according to
Excessive pre-blow air due to the parison being narrowed during the mold closing process can be successfully processed through the opening.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of a blow molding apparatus and a blow molding method according to the present invention will be described in detail. 1 to 10 show an embodiment of a blow molding apparatus and a blow molding method according to the present invention. FIG. 1 is a schematic perspective view of a blow molding apparatus in a mold open state, and FIG. 2 shows a closed part of a parison with a frame and a lower plate. FIG. 3 is an explanatory vertical cross-sectional view in which the body is suspended to a position passing through the body.
FIG. 4 is an explanatory longitudinal sectional view in which the entire pair of split dies are advanced in the closing direction to close the frame body and the upper plate body from the state of FIG. 4, FIG. 4 is a view taken along the line IV-IV in the state of FIG. FIG. 5 is an explanatory longitudinal sectional view in which the process proceeds from the state of FIG. 3 and the frame body and the lower plate body are closed, FIG. 6 is a view taken along the line VV in the state of FIG. 5, and FIG. Vertical sectional explanatory view at the time when one of the split dies is further advanced against the compression coil spring inserted into the cylinder rod for use, and both front end surfaces of the frame abut both front end surfaces of the other split die, 8 is a view taken along the line IX-IX of FIG. 7, FIG. 9 is a longitudinal sectional view when the cut-away portions of the split type abut each other, and FIG. 10 is a view taken along the line XX of FIG. is there.

(1) Blow Molding Apparatus The blow molding apparatus includes a pair of split dies 1 and 2, a frame 3, an upper plate 4 and a lower plate 5. The pair of split dies 1 and 2 are arranged so as to be openable and closable in the horizontal direction below a die 9 for extruding the cylindrical parison 10 so that the parison 10 descending from the die 9 can be clamped. Each of the split molds 1 and 2 has a quadrangular prism shape, and the cavity surfaces 11 and
21 are formed. After clamping the two halves 1 and 2, the main blow is performed to obtain a desired deep drawn product. One of the split male molds 1 having the convex cavity surface 11 forms an edge-shaped biting portion 12 related to a pinch-off portion around the cavity surface. Concave cavity surface 21
The other split female mold 2 having
A cutout portion 22 is formed at a position around the cavity surface 11 corresponding to 2. Further, the width W ₁ of the female die 2 have greater than the width W ₂ of the male mold 1 (FIG. 8), the end face 2 on both sides further outside than outright parts 22 eating the female mold 2
3,23 are overhanging. Reference symbol P ₁ is a support shaft for moving the male mold 1 forward and backward together with the frame 3 in the horizontal direction.
Fixed one end thereof to the male 1 male 1 so that the parison 10 can be clamped between the female mold 2 by advancing the support shaft P _1. Reference numeral P ₂ is fixed to one end to the female mold 2, the top plate 4, a support shaft for forwardly and backwardly moving the female mold 2 together with the lower plate body 5.

The frame 3 is a rectangular tubular frame having a predetermined thickness and a constant width. The upper plate 4 and the lower plate 5 which will be described later.
The front end surfaces 31 and 32 facing each other have a curved surface shape corresponding to the molded product. The frame 3 is slidably attached around the outer periphery of the square pillar-shaped side surface of the male mold 1. Specifically, the bearing 6 is fixed to both side surfaces of the male mold 1, and one end of a horizontal rod 6a is inserted into the bearing. After the compression coil spring 61 is inserted into the rod 6a, the other end of the rod is fixed to the rear end face of the frame 3. In response to the urging force of the coil spring 61, the front end surfaces 31, 32 of the frame 3 protrude more toward the parison than the cavity surface 11 of the male mold 1 in the mold open state (FIG. 1). When a force against the urging of the coil spring 61 is applied, the coil spring 61 is contracted, and the rod 6a retreats in the bearing 6, and together with this, the frame 3 also slides on the outer periphery of the side surface of the male mold 1 and moves backward in the male mold. I try to retreat. In FIGS. 3 to 5, 7, and 9, the upper front end face 31 and the lower front end face 32 of the frame body 3 are integrated so as to be easily understood.
Although the frame 3 is drawn in a box shape, the frame 3 is a rectangular cylindrical frame that is fitted around the outer periphery of the side surface of the male mold 1 as described above (FIG. 1). In the figure, the front end faces (the upper front end face 31 and the lower front end face 3) of the frame body 3, the upper plate body 4, and the lower plate body 5 are shown.
2 and the front end faces 41 and 52) mean those end faces facing the parison side.

The upper plate 4 is provided on the upper surface of the female die 2 and
Is a plate having a predetermined thickness arranged so as to face the upper front end surface 31 of the first plate. The upper plate body 4 is slidably mounted in the opening and closing direction of the split mold 2, and is closed when the upper front end face 31 is closed.
Abut. The upper plate 4 has bearings 7 fixed to two locations on the upper surface of the female mold 2 and one end of a rod 7a that is leveled with each bearing 7 is inserted. After the compression coil spring 71 is inserted into the rod, the other end of the rod is fixed to the rear end face of the upper plate 4. Under the bias of the coil spring, the front end surface 41 of the upper plate 4 protrudes from the cavity surface 21 of the female mold 2 toward the parison side from the lower plate 5 to be described later in the mold open state (FIG. 1). ). In addition, the front end face 41 of the upper plate body 4 facing the frame body 3
Also, similarly to the frame 3, by forming a curved surface shape corresponding to the product of the molded product and closing the frame 3 and the upper plate 4 with the parison 10 interposed therebetween, the closed portions 101,
104 is made easy.

The lower plate 5 is provided on the lower surface of the female die 2 and
Is a plate of a predetermined thickness arranged so as to face the lower front end surface 32 of the lower plate. The lower plate 5 is slidably mounted in the opening and closing direction of the split mold 2, and is closed when the mold is closed.
Abut. The lower plate 5 also has two bearings 8 fixed to the lower surface of the female die 2, and one end of a rod 8 a that is horizontal to each bearing 8 is inserted. After the compression coil spring 81 is inserted into the rod, the other end of the rod is fixed to the rear end face of the lower plate 5. The front end surface 52 of the lower plate 5 protrudes toward the parison side from the cavity surface 21 of the female mold 2 in the mold open state under the bias of the coil spring 81. However, as described above, the upper plate 4 is disposed at a position retracted rearward. Here, the lower plate 5
The strength of the urging force against the external force of the coil spring 81 is set to be substantially the same as that of the upper plate 4. On the other hand, the strength of the pressing urging force opposing the external force of the coil spring 61 of the frame 3 is determined by the two coil springs 71 of the upper plate 4 and the lower plate 5,
81 is set to be larger than the strength of the urging force against the external force. The front end face 52 of the lower plate 5 facing the frame 3 also has a curved shape corresponding to the molded product, similarly to the frame.

The bearings 6, rods 6a, and coil springs 61 of the frame 3 are fixed, for example, by fixing an air cylinder to the male mold 1 and fixing the cylinder rod of the cylinder to the frame 3, and by operating the cylinder. The frame 3 is slidable, and the front end face 3 of the frame 3 is opened as described above.
1 and 32 can also be arranged on the parison side from the cavity surface 11 of the male mold 1. Similarly, instead of the bearing 7, the rod 7a, and the coil spring 71 of the upper plate 4 (or the lower plate 5),
An air cylinder is fixed to the female mold 2 and a cylinder rod of the cylinder is fixed to the upper plate 4 (or the lower plate 5),
The upper plate 4 (or the lower plate 5) may be arranged to be slidable by a cylinder operation.

(2) Blow molding method Next, a blow molding method using the above blow molding apparatus will be described. First, the parison 10 is extruded between the split dies 1 and 2 in the mold opened state. Then, the lower end of the parison 10 is welded by a known pinch-off means to close the closed portion 1.
01 to form a bottomed parison (FIG. 1). Code 10
3 indicates a surplus end.

Thereafter, a pre-blowing process is performed by blowing a predetermined amount of air into the parison to prevent fusing, and the parison 10 having a certain degree of swelling while securing an appropriate internal pressure is drooped. Pre-blow is by top blowing. The parison 10 extruded from the die 9 reaches a position where the closed portion 101 passes between the frame 3 and the lower plate 5. The closed portion 101 is moved to a position slightly below the horizontal line connecting the frame 3 and the lower plate 5 as shown in FIG. 2 (first step).

Next, the support axes P ₁ and P ₂ are advanced to start the mold closing of the split molds 1 and 2. As the mold closing progresses, first, the frame 3 and the upper plate 4 are closed as shown in FIG. 3 (second step). The frame 3 protrudes from the male mold 1 and the upper plate 4
Is projected from the female mold 2 and the lower plate 5 toward the parison. When the frame 3 and the upper plate 4 are closed, the upper end of the parison close to the die 9 is sealed to form a seal portion 104, and the sealed parison 10a is formed. The sealed parison 10a is formed by the frame 3 and the upper plate 4, but the frame 3 and the lower plate 5 are still separated at this point, so that the parison between the two is not closed, and the conductive portion 102 is formed. Is secured. In addition, the closed portion 101 is lowered to a position slightly below a horizontal line connecting the frame 3 and the lower plate 5.
Accordingly, as the mold closing progresses, the conducting portion 102 of the parison 10 functions as a relief. Excess pre-blown air passes through the conducting portion 102 and forms a bulging portion 105a outside the mold (downward) in search of a place to escape, thereby preventing puncturing. FIG. 4 is a plan sectional view taken along line IV-IV in FIG.
It is like. The male mold 1 and the female mold 2 are still in a mold open state far apart.

Subsequently, the mold is further closed by advancing the support shafts P ₁ and P ₂ . Upper plate 4
Is already in contact with the frame 3 with the parison 10 interposed therebetween, and as the female mold 2 advances (in the direction of the white arrow in FIG. 1) as the mold closes, the lower plate 5 is While moving forward together, the upper plate 4 contracts the coil spring 71 and retreats relatively to the female mold 2. Then, as shown in FIG.
Then, the lower plate 5 is closed (third step). When the frame 3 and the lower plate 5 are closed, another seal portion 109 is formed on the parison 10 slightly above the closed portion 101 provided at the lower end of the parison. The conducting portion 102 is closed, and the parison is narrowed by closing the mold, so that excess pre-blow air is discharged into the inflatable bag 105. A plan sectional view taken along line VV in FIG. 5 is as shown in FIG. Even when the mold is tightened from the second step to the third step, the male mold 1 and the female mold 2 are still in the mold open state apart from each other, and the front end surfaces 33 on both sides of the frame 3 and the female mold 2 There is an open space S between them. When the mold is tightened, the parison 10 moves to the front end face 33 on both sides of the frame.
And the female die 2 swells toward the open space S, and absorbs the surplus portion of the pre-blow air well.

Further, the mold closing is further advanced by advancing the support shafts P ₁ and P ₂ . By compressing the coil springs 61, 71, 81, the upper plate 4 and the lower plate 5 retreat relatively to the female mold 2, and the frame 3 retreats relatively to the male mold 1 ( As shown in FIG. 7) and FIG.
The front end faces 33 of both sides abut on both side end faces 23 of the female mold 2 (fourth step). Frame body both side front end face 33 and female mold 2
The excess pre-blow air which sewed the opening space S of the side and sought an escape in both sides creates a bulging part 106,
I will dodge the punk of Parison 10. FIG.
8, the front end surfaces 33 on both sides of the frame 3 are in contact with the both end surfaces 23 of the female mold 2 to form a seal portion of the bulging portion 106. It is not necessary to seal the bulging portion 106 over the entire area, and it is also possible to provide a partial cutout in the frame 3 or the female mold 2 and leave a conduction portion in the parison 10. By doing so, the escape of the surplus pre-blow air into the bulging portion 106 continues even after the fourth step.

Thereafter, the mold closing is advanced by further extending the support shafts P ₁ and P ₂ to close the pair of split dies 1 and 2, and as shown in FIG. 22 and 12 are brought into contact (fifth step). And
After closing the mold and removing the surplus parison 107, finally, a main blow is performed into the parison in the cavity to form a blow-molded article shaped into a cavity (sixth step). After the blow-molded article is cooled, it is demolded to obtain a desired product.

The blow molding apparatus and the blow molding method configured as described above cause the parison 10 to be punctured during the blow molding process even in a deep drawing shape such as an instrument panel having a complicated shape having irregularities in the short direction. It is possible to produce a desired molded product without the need. When trying to produce the deep drawn product, the parison 10
Is performed so as not to inadvertently fuse, but in the process of closing the mold and closing the mold, the parison tends to be narrowed, and excess processing of the pre-blown air is required. The surplus portion of the pre-blowing air has lost a place to escape and has caused a puncture of the parison 10, but in the present invention, the surplus portion is closed while the mold is closed and the molding process is advanced to eliminate the puncture. As the mold closes, the frame 3,
By moving the upper plate 4, the lower plate 5, the split molds 1 and 2 independently, the frame 3 and the upper plate 4, the frame 3 and the lower plate 5, the frame 3 and both sides of the female die. 33, the parison 10 is narrowed in the blow molding process, and the surplus portion of the generated air is sequentially eliminated while shifting the closing timing of the open portion according to conditions such as the bite portions 12 and 22. That is, in the first and second steps, the excess portion of the pre-blowing air is released below the split mold using the conductive portion 102. Further, in the third step to the fourth step, the excess portion of the pre-blowing air is released to both sides by using the open spaces S on both sides of the frame 3 and the female mold 2. In the process of closing the mold, the frame 3, upper plate 4, lower plate 5
However, while contributing to maintaining the shape of the sealed parison 10a, the surplus portion of the pre-blow air is dissipated in a stepwise manner outside the split dies 1 and 2 to effectively avoid puncturing of the parison. Like an instrument panel, it has a large deep drawing, a long car width direction and a relatively short car direction, and is effective for complex shapes with irregularities in the short car direction. The frame 3, the upper plate 4, and the lower plate 5 form a sealed parison 10.
Since the main part of the parison can be reliably filled in the cavity by guarding a and using the double blow method, it is possible to improve the creasing transferability and the like, which has been a concern in the past. In addition, in the present embodiment, support shaft P _1, P ₂ only a pair split 1 moves, the frame 3, the top plate 4, there is also a mold closing capable of advancing the benefits of the lower plate body 5 . Thus, it is possible to successfully manufacture even a complicated deep drawing product by blow molding.

The present invention is not limited to the embodiment described above, but can be variously modified within the scope of the present invention depending on the purpose and application. The shape, size, and the like of the split molds 1, 2, the frame 3, the upper plate 4, the lower plate 5, and the parison 10 can be appropriately selected according to the application.

[0021]

As described above, according to the blow molding apparatus and the blow molding method of the present invention, even a deep drawn product having a complicated shape can be formed into a desired blow molded product without puncturing the parison. It has excellent effects, such as giving the product a wider shape and helping to improve yield.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view of one embodiment of a blow molding apparatus according to the present invention, showing the blow molding apparatus in a mold open state.

FIG. 2 is an explanatory longitudinal sectional view in which a closed portion of a parison is suspended to a position passing through a frame and a lower plate.

FIG. 3 is an explanatory longitudinal sectional view in which a pair of split dies are advanced from the state of FIG. 2 to close a frame and an upper plate.

FIG. 4 is a view taken along the line IV-IV in the state of FIG. 3;

5 is an explanatory longitudinal sectional view in which the process proceeds from the state of FIG. 3 and the frame and the lower plate are closed.

FIG. 6 is a view taken along line VV in the state of FIG. 5;

FIG. 7 is an explanatory longitudinal sectional view when the male mold is further advanced against the compression coil spring of the cylinder rod for the frame, and the front end faces on both sides of the frame contact the front end faces on both sides of the female mold. .

FIG. 8 is a view taken along line IX-IX in FIG. 7;

FIG. 9 is an explanatory vertical cross-sectional view when the split-type bite portions come into contact with each other.

FIG. 10 is a view taken along line XX of FIG. 9;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Male type (one split type) 12 Biting portion 2 Female type (the other split type) 22 Biting portion 3 Frame 31 Upper front end surface 32 Lower front end surface 4 Upper plate 5 Lower plate 9 Dice 10 Parison 10a Sealed parison 101 Blockage 107 Extra parison 109 Another seal (another block)

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[Procedure amendment]

[Submission date] October 27, 1999 (1999.10.
27)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claims

[Correction method] Change

[Correction contents]

[Claims]

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0005

[Correction method] Change

[Correction contents]

[0005]

In order to achieve the above object,
The gist of the present invention according to claim 1 is a blow molding apparatus including a die for extruding a parison, and a pair of split dies that are arranged so as to be able to sandwich the parison below the die and that can be opened and closed in a horizontal direction. A frame body (3) slidably mounted around the outer periphery of the side surface of one of the split dies, and an opening / closing direction of the split die facing the upper front end surface of the frame on the upper surface of the other split die. The upper plate body (4) which is slidably mounted on the upper mold body and which comes into contact with the upper front end face when the mold is closed, and the lower surface of the other split mold,
The frame is slidably mounted opposite to the lower front end face in the closing direction of the split type, comprises contacting the lower plate member to the lower front end in the mold closing and (5), the said frame And upper plate and lower plate
Can be moved independently and independently, and
In the open state, the front end face of the frame is one of the split-type cavities.
Protruding toward the parison side from the
The end face and the front end face of the lower plate are the same as the cavity face of the other split mold.
Protruding toward the parison, and in front of the upper plate
The end face is protruded to the parison side from the front end face of the lower plate.
First, as the mold closing progresses, first, the frame and the upper plate
A blow molding apparatus characterized in that the body is closed . Gist of the present invention according to claim 2, in claim 1
Using the blow molding apparatus described , the lower end of the parison is welded to form a closed part and pre-blow is performed, and the parison is suspended until the closed part passes between the frame and the lower plate, Then, the split mold is advanced in the closing direction, the frame and the upper plate are closed, and the upper end of the parison is sealed to form a sealed parison. Subsequently, the frame and the lower plate are closed and the upper portion of the closed portion is closed. After making another closed part, after closing the pair of split molds and abutting the bite-cutting parts pertaining to both split molds to eliminate the surplus parison, the main blow is performed into the sealed parison. Blow molding method.

[Procedure amendment 3]

[Document name to be amended] Statement

[Correction target item name] 0010

[Correction method] Change

[Correction contents]

The upper plate 4 is provided on the upper surface of the female die 2 and
Is a plate having a predetermined thickness arranged so as to face the upper front end surface 31 of the first plate. The upper plate body 4 is slidably mounted in the opening and closing direction of the split mold 2, and is closed when the upper front end face 31 is closed.
Abut. The upper plate 4 has bearings 7 fixed to two locations on the upper surface of the female mold 2 and one end of a rod 7a that is leveled with each bearing 7 is inserted. After the compression coil spring 71 is inserted into the rod, the other end of the rod is fixed to the rear end face of the upper plate 4. A structure in which the front end surface 41 of the upper plate 4 projects toward the parison side from the cavity surface 21 of the female mold 2 and further from the front end surface 52 of the lower plate 5 to be described below in a mold open state by receiving the urging force of the coil spring. (FIG. 1). The front end face 41 of the upper plate body 4 facing the frame body 3 also has a curved surface shape corresponding to the molded product, similarly to the frame body 3, and the frame body 3 and the upper plate body 4
To close the closed part 1 along the shape of the molded product.
01 and 104 are made easier.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0019

[Correction method] Change

[Correction contents]

The blow molding apparatus and the blow molding method configured as described above cause the parison 10 to be punctured during the blow molding process even in a deep drawing shape such as an instrument panel having a complicated shape having irregularities in the short direction. It is possible to produce a desired molded product without the need. When trying to produce the deep drawn product, the parison 10
Is performed so as not to inadvertently fuse, but in the process of closing the mold and closing the mold, the parison tends to be narrowed, and excess processing of the pre-blown air is required. The surplus portion of the pre-blowing air has lost a place to escape and has caused a puncture of the parison 10, but in the present invention, the surplus portion is closed while the mold is closed and the molding process is advanced to eliminate the puncture. As the mold closes, the frame 3,
By moving the upper plate 4, the lower plate 5, the split molds 1 and 2 independently, the frame 3 and the upper plate 4, the frame 3 and the lower plate 5, the frame 3 and both sides of the female die. 23 , the parison 10 is narrowed in the blow molding process, and the surplus portion of the generated air is sequentially eliminated while shifting the closing timing of the open portion, such as the bite portions 12 and 22. That is, in the first and second steps, the excess portion of the pre-blowing air is released below the split mold using the conductive portion 102. Further, in the third step to the fourth step, the excess portion of the pre-blowing air is released to both sides by using the open spaces S on both sides of the frame 3 and the female mold 2. In the process of closing the mold, the frame 3, upper plate 4, lower plate 5
However, while contributing to maintaining the shape of the sealed parison 10a, the surplus portion of the pre-blow air is dissipated in a stepwise manner outside the split dies 1 and 2 to effectively avoid puncturing of the parison. Like an instrument panel, it has a large deep drawing, a long car width direction and a relatively short car direction, and is effective for complex shapes with irregularities in the short car direction. The frame 3, the upper plate 4, and the lower plate 5 form a sealed parison 10.
Since the main part of the parison can be reliably filled in the cavity by guarding a and using the double blow method, it is possible to improve the creasing transferability and the like, which has been a concern in the past. In addition, in this embodiment, there is an advantage that the mold closing of the pair of split dies 1, 2, the frame 3, the upper plate 4, and the lower plate 5 can be advanced only by moving the support shafts P1, P2. Thus, it is possible to successfully manufacture even a complicated deep drawing product by blow molding.

[Procedure amendment 5]

[Document name to be amended] Drawing

[Correction target item name] Fig. 8

[Correction method] Change

[Correction contents]

FIG. 8

Continuing from the front page (72) Inventor Takaya Tejima 8-1, Tocho, Fujii-cho, Anjo-shi, Aichi Prefecture Inoac Corporation Sakurai Office (72) Inventor Yasunori Sakamoto 1-4-1, Chuo, Wako-shi, Saitama Co., Ltd. Honda R & D F term (reference) 4F202 CA15 CB01 CK53 4F208 LA01 LA05 LA07 LB01 LD04 LD08 LD12 LD14 LG02 LG10 LG22 LG31 LH02 LJ01 LN01 LW01

Claims (2)

[Claims] 1. A blow molding apparatus comprising: a die for extruding a parison; and a pair of split dies arranged so as to be able to hold the parison below the die and capable of being opened and closed in the horizontal direction. A frame (3) that is slidably mounted around the frame, and the upper surface of the other split die is slidably mounted in the opening and closing direction of the split die in opposition to the upper front end surface of the frame. Upper plate body (4) which is brought into contact with the upper front end face when the mold is closed
And a lower plate body (5) that is slidably mounted on the lower surface of the other split mold in the opening and closing direction of the split mold so as to face the lower front end face of the frame, and abuts on the lower front end face when the mold is closed. And a blow molding apparatus. 2. Using the blow molding apparatus, the lower end of the parison is welded to form a closed portion and pre-blow is performed, and the parison is suspended to a position where the closed portion passes between the frame and the lower plate. Then, the split mold is advanced in the closing direction, the frame body and the upper plate body are closed, and the upper end of the parison is sealed to form a sealed parison. Subsequently, the frame body and the lower plate body are closed to close the closed parison. Create another closed part above the part, then close the pair of split molds and abut the cutout parts of both split molds to eliminate excess parison, then perform main blow into the sealed parison Blow molding method characterized by the above-mentioned.