JP3218094B2 - Blow molding equipment - Google Patents

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 more particularly to a blow molding apparatus for obtaining a blow molded product having a flat cross section.

[0002]

2. Description of the Related Art In recent years, in the case of automobile seats, in order to reduce the weight of vehicles, attempts have been made to replace a seat back frame, which has generally been made of metal, with a blow-molded product of a synthetic resin material. For example, Japanese Patent Publication No. 62-48
488).

[0003] In general, a hinge mechanism is provided at both ends of a seat back frame, and the hinge mechanism is connected to the vehicle body via the hinge mechanism. Although it is required to have a thin structure, the central portion serving as the backrest does not need to be as rigid as both ends, so a thin structure is sufficient.

When the seat back frame is manufactured by blow molding, since the seat back frame usually has a flat cross section, it is difficult to expand the parison extruded into a cylindrical shape in a molding die as it is. It is difficult to properly align the parison with the molding surface of the molding die, so that sufficient molding accuracy cannot be secured. As a method of solving such a problem, before the parison is put into the molding die, as a pre-process, the cylindrical parison is stretched flat to give a shape close to the product shape, and then attached to the molding die. Attempts have been made to perform predetermined blow molding. However, when the parison is stretched in a flat shape prior to the blow molding in this way, if this is simply stretched using a pair of left and right stretching pins,
The ends which are directly in contact with the respective extension pins and are subjected to the extension action have the largest extension and are thinner, while the central portion located between them is thicker because the extension is relatively small. You. That is, the seat back frame has a thickness structure opposite to that originally required.

[0005] From such a background, the applicant of the present application can maintain the thickness of both ends of a blow product having a flat cross-sectional shape by improving the inappropriateness of the thickness structure of the blow molded product as described above. A blow molding apparatus has been developed and filed (Japanese Patent Application No. 4-41408). That is, the blow molding apparatus according to the above-mentioned application applies a pair of elongate members having a semicircular contact surface along the inner peripheral surface of the parison and capable of maintaining the contact surface at a temperature lower than the parison temperature. They are arranged so as to be able to contact and separate from each other with the surface facing outward. Then, the pair of extending members are inserted into the parison in a state where they are brought close to each other (that is, in a substantially cylindrical state), and the parisons are moved in the separating direction to flatten the parison. In this case, the two ends of the parison, which are extended in direct contact with the respective extension members, are cooled by the contact with the extension members and their fluidity is reduced. Thickness is maintained in spite of the stretching action. Therefore, by mounting the parison having the thick ends at the both ends in a molding die and performing blow molding, a blow molded product having thick ends at both ends in the flat direction can be obtained. Therefore, when this blow molding apparatus is applied to the molding of a seat back frame, both ends required for rigidity are thick,
On the other hand, the central portion, which is relatively low in rigidity, is formed to be thin, and as a result, a seat back frame having the originally required thick structure can be obtained.

[0006]

However, generally, as shown in FIG. 23, the shape of the both ends required to be thick is not a straight line extending from the lower end to the upper end of the seat back frame, as shown in FIG. Because of the so-called tapered shape in which the portion from the middle part to the upper end is inclined inward, a parison that is stretched from a cylindrical shape to a flat shape as a pre-process of blow molding by a mold (hereinafter, referred to as a stretched parison) Need to be tapered and stretched to approximate the product shape. To this end, as shown in FIG. 24, the distal end portions 67a of the respective extension members 67, 67
Is formed in a conical shape, and its outer peripheral surface needs to be inclined toward the axis of the parison 66.

However, the inclination angle (θ) and the amount of deviation (t) of the distal end portion 67a of the extension member 67 are determined by adjusting the pair of extension members 67, 67 in an approaching state (the outer peripheral surface distance L ₁ ). 23 is limited by the inner diameter (D) of the parison 66 due to the insertion into the interior of the parison 66, and in some cases, the inclination angle (θ) of the upper part of the seat back frame 65 as a product as shown in FIG. ₀ ) and the amount of deviation (t ₀ ) cannot be ensured (that is, θ <θ ₀ , t <
t ₀ ).

In such a case, use is made of the stretching members 67, 67 having such a shape that the inclination angle and the amount of deviation are inappropriate, and this is inserted into a cylindrical parison 66 as shown in FIG. In this state, the parison 6 is separated (the outer peripheral surface distance L ₂ ).
If you extend 6 to make it an extended parison 68,
The shape of the upper portion 68a of the elongate parison 68 is larger than the shape originally required from the product side (shown by a dashed line, see reference numeral 68a '). In other words, the upper part of the extended parison 68 is extended more than necessary,
In addition, since the unnecessarily stretched portion is also in contact with the stretching member 67, the portion is naturally thicker than the central portion.

[0009] Therefore, the above-mentioned stretching members 67, 67 are removed from the stretching parison 68, and pressurized air is lightly blown into the stretching parison 68 with the lower end opening closed with a pre-pinch panel. In the inflated pre-blow state, as shown in FIG.
Prebrow parison 69 with the upper part swelling moderately
Where the extended parison 6 is used as described above.
Since the upper end portion 68a of the pre-blow parison 69 itself is unnecessarily elongated, the upper end portion 69a of the pre-blow parison 69 also has the shape originally required from the product side (shown by a dashed line, reference numeral 69a). ′), And portions of the thick portions 71 (hatched portions in FIG. 26) at both ends also protrude outward from the required shape.

Therefore, when this pre-blow parison 69 is finally mounted on a molding die (not shown) and blow molded, as shown in FIG. A lower surplus portion 74 is provided at a lower end portion, and a product portion 73 is provided.
The upper surplus portions 75 are respectively extended to the upper end portions of the pre-blow parisons 6 as described above.
Since the part which protrudes outside the required shape of 9, particularly a part of the thick part, is removed as excess, the product part 7 which should have been originally formed thick by this thick part
The upper end portions 73a, 73a of 3 have to be thinned due to lack of wall thickness. That is, despite the fact that both ends of the elongated parison 68 are formed thick from the lower end side to the upper end side in the parison extending step, this thick part cannot be fully utilized in the thick structure of the product part 73. As a result, as a result, dissatisfaction remains in terms of increasing the rigidity of both ends of the product, and the effective use of the material cannot be achieved due to an increase in excess thickness.

Therefore, the present invention secures an appropriate thickness at both ends of a product when a tapered product is formed by blow molding using a parison which is elongated in a flat shape and whose both ends are thickened. Accordingly, the present invention has been made to provide a blow molding apparatus capable of improving the rigidity thereof and promoting the effective use of the material.

[0012]

According to the present invention, as a specific means for solving the above-mentioned problems, in the present invention, a thermoplastic synthetic resin material is extruded as a cylindrical parison having a predetermined thickness. And a lower member and an upper member of a predetermined length each having a contact surface on an outer surface side are connected to bendable in a direction perpendicular to the contact surface, and the lower member is erected substantially vertically. A pair of extension members supported movably in the vertical direction and the bending direction in a state where
Each of the contact surfaces is opposed to each other with the respective contact surfaces facing outward, and each of the upper members is inwardly opposed in the opposite direction while abutting against the inner surface of the parison when the upper member is inserted into the parison to extend the parison. A parison extending means configured to be tiltable; a temperature adjusting member for maintaining the temperature of the contact surface of the extending member at a predetermined temperature lower than the temperature of the parison; In the combined state, a molding die for forming a molding space of a predetermined shape therein, and pressurized air supply means for supplying pressurized air to a parison accommodated in the molding space of the molding die are provided. Features.

According to a second aspect of the present invention, in the blow molding apparatus according to the first aspect, the upper members of the pair of extending members constituting the parison extending means are connected by pins at upper ends thereof. I have.

According to a third aspect of the present invention, in the blow molding apparatus according to the first aspect, the upper members of the pair of extending members constituting the parison extending means are connected at their upper ends via link members. It is characterized by:

According to a fourth aspect of the present invention, in the blow molding apparatus according to the first, second or third aspect, the upper member is divided into a plurality of members in an axial direction thereof.
The plurality of members are connected to each other so as to be bendable .

[0016]

In each invention of the present application, the following effects can be obtained by adopting such a configuration.

According to the first aspect of the present invention, a pair of elongating members of the parison elongating means are brought close to each other and are pushed out of the extruder into a cylindrical shape and are suspended inside the parison at the lower end thereof. Insert from.

In this state, the pair of stretching members of the parison stretching means are moved apart from each other, and the parison is stretched flat to form a stretched parison. in this case,
Among the parisons, both ends in the extending direction that directly contact the contact surfaces of the lower member and the upper member of each of the extending members are cooled by the lower member and the upper member and the fluidity thereof is reduced. The fluidity of the middle portion in the stretching direction, which does not directly contact the surface, is maintained relatively high. Therefore,
At both ends in the elongating direction, the thickness is maintained thick, while at the intermediate part, it is relatively thin, and a predetermined thickness difference occurs between the both ends and the intermediate part.

On the other hand, in accordance with the stretching action of the parison, the upper members of the respective stretching members are gradually inclined inward in the stretching direction by receiving the stretching force of the parison. To obtain a tapered elongated parison that is even more inclined than the molded shape when the extending member is integrated and the upper part is inclined, and is close to the product shape even if the product has a large degree of taper. Can be done.

In this manner, a tapered elongated parison, which more closely approximates the shape of the tapered product and whose both ends in the stretching direction are formed thick from the lower end to the upper end, is set in a molding die. When this is blow-molded, the portion removed as surplus in the thick portion at both ends is reduced by the amount of approximation of the shape of the elongated parison to the product shape. The thickness of the upper end portions is maintained as thick as the lower end portions in spite of being tapered.

According to the second aspect of the present invention, in addition to the above-described effects, the upper members of the pair of extending members are pin-connected at their upper ends, so that the lower members are separated from each other. The upper members are tilted and displaced in synchronization with the operation, and the tilt angles (that is, the degree of taper) on the upper left and right sides of the molded product are set to be the same.

According to the third aspect of the present invention, in addition to the above-described effects, the upper members of the pair of extending members are connected to each other via the link members at the upper ends thereof. With the separating operation of the side members, the respective upper members are separated from each other while being inclined in synchronization with each other, whereby the inclination angles of the upper left and right sides of the molded article are set to be the same, and substantially the entire upper member is formed. It is possible to participate in the stretching action of the parison (in other words, to eliminate the part remaining in a non-contact state inside the cylindrical parison), for example, the same length of the inclined part of the molded article In this case, it is possible to reduce the length of the upper member by an amount that does not involve the extension.

According to the invention described in claim 4, the above-mentioned.
In addition to the operation described, since the upper member foldably connected to the lower member is divided into a plurality of members in the axial direction and these are foldably connected to each other, As the lower member moves in the stretching direction, the upper member is bent in multiple stages, and both ends of the upper portion of the stretching parison are formed in an appropriate curved shape.

[0024]

According to the blow molding apparatus of the present invention, the following effects can be obtained.

(A) According to the blow molding apparatus of the first aspect, when a product having a tapered shape whose cross section is flat and whose upper end portion is inclined inward in the width direction is obtained by blow molding,
By making the upper member of the stretching member, which is subjected to the parison stretching operation as a pre-stage of molding by the molding die, tiltable in the stretching direction, the cross-section obtained by the stretching operation has a flat cross section and both ends in the stretching direction. The thickness of the inclined parison is reduced by reducing the amount of part of the thick part removed as excess as much as possible by approximating the shape of the thickened parison to the product shape. Because it can be maintained properly, regardless of the diameter of the parison, it is possible to easily obtain a product with a large degree of taper while securing the appropriate thickness at both ends thereof, This has the effect of ensuring both rigidity at both ends of the tapered product and effective use of the molding material.

(B) According to the blow molding device of the second aspect, in addition to the effect of the above (a), the upper members of the respective extending members are inclined in synchronization with the progress of the parison extending operation. By doing so, it is possible to obtain an extended parison having the same shape on the left and right sides, so that an effect that a high level of molding accuracy of the product can be secured can be obtained.

(C) According to the blow molding apparatus of the third aspect, in addition to the effect described in the above (a), the upper members of the respective extending members are inclined in synchronization with the progress of the parison extending operation. By separating them from each other, it is possible to obtain a stretched parison of the same shape on the left and right, so that a high level of molding accuracy of the product can be secured, and the above upper member has been removed from the part that does not contribute to the stretching action of the parison As a result, it is possible to reduce the size and weight of the device as a short shape. (d) According to the blow molding apparatus according to claim 4, (a)
(C) In addition to the effects described in (c), since the upper end portions of the elongated parison can be formed in a curved shape, the shape of the elongated parison can be more closely approximated to the product shape, and accordingly, the taper is reduced. Ensuring the rigidity of both ends of the shaped product and effectively utilizing the molding material are further promoted.

[0028]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a blow molding apparatus according to the present invention.

First Embodiment FIG. 1 shows a blow molding apparatus Z according to a first embodiment of the present invention. As shown in FIGS. 9 and 10, the blow molding apparatus Z has a center part in the width direction as a backrest part 61a made of two plate materials facing each other with a small gap, and has both ends in the width direction in front of the seat. It has a substantially concave flat cross section as a bank portion 61b, 61b bulging to the side, and has substantially the same width dimension from the lower end portion 61c to the middle step portion 61d.
1d to an upper end portion 61e are for integrally molding by blow molding an automobile seat back frame 61 having a tapered planar shape whose width is gradually reduced. An extruder 1 which is sequentially extruded in a semi-molten state at 225 ° C. in a hanging state to form a parison 2, a pair of molding dies 3, 3 and a pair of pre-pinch panels 5, described later, and the gist of the present invention. And a pair of elongate members 7,7.

The molding dies 3, 3 are arranged below the extruder 1 so as to be movable in the direction of contact and separation with the axis of the extruder 1 interposed therebetween. A molding space of a predetermined shape is formed inside. The molding dies 3, 3 are always kept at 60 to 65 ° C. by appropriate heating means.
At that temperature. Further, one side of the pair of molding dies 3, 3 is provided with a blow nozzle 4 (pressurized air in the claims) in a state where it penetrates from the outer surface and its tip projects above the molding surface 3a. (Corresponding to a supply means).

The pre-pinch panels 5, 5 are plate members which are disposed at positions below the molding dies 3, 3 so as to sandwich the parison 2 in the radial direction thereof and to be opposed to each other by cylinders 6, 6 so as to be able to approach and separate from each other. In the approach state, the lower end of the parison 2, more precisely, the lower end of the later-described extended parison 50, is tightened from both sides to act to seal it.

As shown in FIGS. 1 and 2, the stretching member 7 has a two-part structure including a lower member 7A and an upper member 7B, which will be described later. The lower member 7A includes a body 7Aa formed of a column having a substantially semicircular cross section, and a skirt 7Ab formed in an enlarged shape continuously from a lower end 7Ae of the body 7Aa.
And a four hemispherical spherical portion 7Ac continuously formed at the upper end of the body portion 7Aa. The lower member 7A is supported by the lifting cylinder 14 with its axis centered in the vertical direction. The lower member 7A is vertically moved by the operation of the lifting cylinder 14 and is fixed to the lifting cylinder 14. The contact / separation cylinder 15 allows the cylinder 7Aa to move in the normal direction at the center in the circumferential direction of the body 7Aa (that is, the direction perpendicular to the plane of the inner side surface 7Ad).

The upper member 7B has a body 7Ba composed of a pyramid having a semicircular cross section as if the truncated cone is vertically divided into two parts through its axis, and a lower end of the body 7Ba. Is formed with a spherical concave portion 7Bc that can be fitted into the spherical portion 7Ac of the lower member 7A. And this upper member 7
B is the spherical concave portion 7Bc of the spherical member 7 of the lower member 7A.
In a state in which Ac is fitted, it is foldably connected by a pair of left and right pivot pins 10, 10.

The cooling water passage 11 (see FIG. 5) formed inside the lower member 7A and the cooling water passage (not shown) formed inside the upper member 7B are mutually connected via a connecting hose 13. The cooling water supply pipe 12 (corresponding to a temperature adjusting member in the claims) provided on the lower member 7A side is connected to the cooling water passage 11 by the cooling water. The member 7A and the upper member 7B are appropriately cooled (the surface temperature of the contact surface is about 3 to 6 ° C.).

The pair of left and right extending members 7, 7 constructed as described above are connected to the inner surface 7Ad of the lower member 7A and the upper member 7A.
B is arranged so as to be able to approach and separate from each other in a state where the inner side surface 7Bd of the second member B is opposed to that of the other extension member 7, and the two upper members 7B, 7B facing each other are connected to the top surface 7B.
The parison extending means in the claims is constituted by being rotatably connected by a hinge 8 provided on Bb.

The extension members 7, 7 can be inserted into the parison 2 in a non-contact state as shown in FIG. 3 and FIG. As shown in FIGS. 4 and 6, relative positions in the contact and separation directions are set so that the parison 2 can project radially outward more than the cylindrical parison 2 and extend the parison 2 in a flat shape. .

Next, a description will be given of an operation procedure and the like when molding a seat back frame using the blow molding apparatus Z.

A: Extrusion of parison 2 First, as shown in FIG. 1, the molds 3, 3 are opened, the pre-pinch panels 5, 5 are separated from each other, and the elongating members 7, 7 are moved to the raised position. Bring it closest. In this state, the extruder 1 is operated to extrude a parison 2 having a predetermined diameter (for example, a diameter of 170 mm) and a predetermined thickness (for example, 8 to 9 mm) from a lower end thereof to a hanging state by an appropriate dimension, and the elongating member 7 is extruded. , 7 (see FIG. 3).

B: Stretching of the parison 2 Next, as shown in FIG. 4, the stretching members 7, 7 are moved away from each other from the state shown in FIG. 2 is flattened to form a stretched parison 50. In this case, since the upper ends of the upper members 7B, 7B of the respective extending members 7, 7 are connected by the hinges 8, the pivot pins 10, 10 are respectively rotated about the rotation center with the separating operation of the lower members 7A, 7A. As tilt inward in the stretching direction. Therefore, the extension parison 50 is formed by the vertical ends 50a, 50a formed by the lower members 7A, 7A that move apart from each other in the vertical standing state, and the upper members 7B, 7B that move apart while tilting. It has a tapered shape having inclined end portions 50b, 50b to be molded, and has a shape more similar to the outer shape of the seat back frame 61 (see FIG. 9) as a product, and is indicated by a chain line (reference numeral 50 ') in FIG. As described above, the upper shape of the parison is smaller than that of the expansion parison when the expansion member 7 is integrated (in other words, there is no unnecessary expansion part).

On the other hand, in the process of extending the parison 2, the outer surfaces of the lower member 7A and the upper member 7B of the parison 2 of the parison 2 are moved with the separating operation of the extending members 7,7. Since the contact surface 7a has a curved shape substantially matching the inner peripheral surface shape of the parison 2, the portion facing the continuous contact surface 7a has a curved shape.
7 from the initial stage of the separating operation of the contact surface 7a.
Will be contacted almost simultaneously. Accordingly, the portion of the parison 2 which is in contact with the contact surface 7a is substantially uniformly and positively cooled by the contact surface 7a having a lower temperature, so that the solidification proceeds at an early stage and the fluidity of the parison 2 increases. In contrast, the portion not in contact with the contact surface 7a is only subjected to the air cooling action, so that its solidification is slow and high fluidity is still maintained.

As described above, the parison 2 is stretched by the above-mentioned stretching members 7 in a state where a difference in fluidity occurs in the circumferential direction, and finally, the parison 2 has a flat cross section as shown by a chain line in FIG. In this case, as described above, the fluidity of the portion in contact with the contact surface 7a of the stretching member 7 is lower than that of the other portion and is substantially uniform over the entire area. Therefore, when the stretching is performed by the stretching members 7, 7, the low fluidity portion does not entirely extend so much, and the high fluidity portion actively extends. As a result, the thickness of the extended parison 50 is such that the entire area of the both ends that have been in contact with the contact surface 7a of the elongate member 7 from the vertical end 50a to the inclined end 50b is thick 51 (for example, 4 , 5 to 5.0 mm), while the middle portion 50c in the stretching direction is thin 52 (for example, 2 mm).
〜2.5 mm).

After the elongate members 7, 7 are separated to a predetermined position to form the elongate parison 50, the elongate members 7, 7 are lowered as they are to be separated from the elongate parison 50. In this case, in the case of this embodiment, the lower end portions of the respective extending members 7, 7 (the lower end portions 7A of the lower member 7A).
Since the skirt portion 7Ab is formed in e), the lower end portion of the extended parison 50 is expanded outward by the skirt portion 7Ab. Accordingly, when the extension member 7 is taken out from the extension parison 50, the lower end of the extension parison 50 does not stick to the contact surface 7a of the extension member 7, and the detachment of the extension member 7 is prevented. This can be performed easily and without breaking the shape of the elongated parison 50.

C: Blow molding Since the elongated parison 50 from which the elongated members 7, 7 have been removed is suspended in a wide state, it is difficult to maintain its shape. For this reason, after removing the extension members 7,7, the lower end of the extension parison 50 is connected to the pre-pinch panels 5,5.
And sealed as a pre-pinch section 55, and low-pressure air is appropriately injected from the extruder 1 side, and the expanded parison 50 is slightly expanded from the shape at the time of molding by the air pressure, and this is expanded into a pre-blown parison. 54 (see FIG. 7). In this case, the stretching member 7 is composed of a lower member 7A and an upper member 7B which are bendable to each other, and in the stretching step of the parison 2, the upper member 7B is tilted to make the parison 2 more than necessary. As shown in FIG. 7, the pre-blow parison 54 is provided with a pre-blow parison (shown by a dashed line and denoted by reference numeral 5) in the case where excessive elongation is performed.
4 '), the upper end has a tapered shape that is cut in a greatly inclined state at the both ends, and has a shape more similar to the product shape.

Next, the pre-blow parison 54 is housed in the molding space of the molding dies 3, 3 and
Is blown through one wall surface of the pre-blow parison 54 into the pre-blow parison 54, and pressurized air of a predetermined pressure is supplied from the blow nozzle 4 to form the pre-blow parison 54 into the molding die 3. , 3 is expanded and deformed along the molding surface. After the molding operation is completed, the molds 3, 3 are opened,
The molded article 57 is taken out from the inside. This molded product 57
As shown in FIG. 8, a lower surplus portion 59 is provided at a lower end of a product portion 58 serving as a seat back frame 61 (see FIG. 9) as a final object, and an upper surplus portion 60 is provided at an upper end. The seat back frame 61 is obtained by removing the lower surplus portion 59 and the upper surplus portion 60 from the molded product 57.

In this case, as described above, since the pre-blow parison 54 is formed into a shape more similar to the product shape, the upper end portions 58a of the product portion 58 in the above-mentioned molded product 57 have extra thickness. Almost no parts are deleted. The fact that the portion to be removed as surplus is reduced as described above means that the upper end portions 58a, 5
In FIG. 8A, the thickness structure in the state of the pre-blow parison 54 is directly reflected as the thickness structure of the molded article 57. Therefore, in the seat back frame 61 as a product, as shown in FIG. 10, the banks 61b, 61b located at both ends in the width direction are formed to be thick, and the backrest 61a at the center is formed to be thin. Needless to say, the thickness of the bank 61b is tapered at the upper end 6 as it is.
1e, the seat back frame 6
The two end portions have a continuous thick structure from the lower end portion 61c to the upper end portion 61e, and the thick structure required for the function of the seat back frame 61 is achieved.

As described above, according to the blow molding apparatus of this embodiment, the parison 2 is prevented from being unnecessarily extended in the elongating step by the divided structure and the bent structure of the elongating member 7, so that the shape is more approximated to the product shape. By obtaining the extended parison 50, the thickness structure at the stage of the extended parison 50 can be directly reflected on the thickness structure of the product after blow molding.

Second Embodiment FIG. 11 shows a blow molding apparatus Z according to a second embodiment of the present invention. The blow molding apparatus Z of this embodiment differs from that of the first embodiment only in the connection structure of the elongating members 7, 7, and the other structures are the same. The description will focus on the connection structure of the extending members 7, 7, and the other portions will be denoted by the same reference numerals as those shown in FIGS.

As shown in FIGS. 11 to 14, each of the extending members 7, 7 has a two-part structure composed of a lower member 7A and an upper member 7B. It is configured to be bendably connected (the basic configuration is the same as that of the first embodiment). Then, the upper members 7B and 7B of the pair of left and right extending members 7 and 7 composed of the lower member 7A and the upper member 7B are attached to the top surface 7B.
The b side is linked via a link member 9 described later.

The link member 9 has a pair of link bars 9A and 9B connected by connecting pins 17, and the other end of one link bar 9A is connected to the upper member 7 of the one extension member 7.
B, the other end of the other link bar 9B is connected to the top surface 7Bb of the upper member 7B of the other extension member 7, and the connecting pin 17 is connected to the cylinder 2
0 engages a guide elongated hole 19 of a guide member 18 which is supported to be vertically movable. The cylinder 2
0 is such that its operation is controlled so as to move up and down in synchronization with the lifting cylinders 14 and 14 (see FIG. 11).

Further, a projection-like stopper 24 is provided on the spherical portion 7Ac of the lower member 7A of each of the extending members 7, 7, and the stopper 24 is allowed to engage with the spherical recess 7Bc of the upper member 7B. And the end of the receiving surface 2
6, a stopper receiving groove 25 is formed, and as shown in FIG. 14, the stopper 24 comes into contact with and engages with the receiving surface 26 to regulate the maximum bending angle of the upper member 7B with respect to the lower member 7A. I am trying to be. In FIG. 12, reference numerals 22 and 23 are respectively formed on the link accommodating portions formed on the upper member 7B and the lower member 7A so that the link members 9 can be accommodated in the state where the extending members 7 and 7 approach each other. It is the rod accommodation part which was done.

The parison 2 is stretched in a flat shape by using the stretching members 7 and 7 having the above-described structure, and the stretched parison 5 is stretched.
To explain the case of setting to 0, first, as shown in FIG. 13, the extending members 7, 7 are brought close to each other and inserted into the inside of the cylindrical parison 2. In this case, the extending members 7, 7 are inserted. 7, the link member 9 is bent and the upper member 7B extends substantially coaxially with the lower member 7A.
In this state, the lower members 7A, 7A and the upper members 7B, 7B of the pair of extending members 7, 7 are in close proximity to each other.
The respective elongating members 7, 7 are moved in a direction away from each other. Then, the lower members 7A, 7A of the respective extension members 7, 7 are vertically extended and their body portions 7Aa contact the inner surface of the parison 2 to extend them. On the other hand, each of the upper members 7B, 7B receives the stretching force from the parison 2 side when the trunk portion 7Ba comes into contact with the inner surface of the parison 2 in accordance with the separating operation of the stretching members 7, 7. It is gradually extended around the pivot pin 10 and tilted inward,
When the stopper 24 comes into contact with the receiving surface 26, further tilting is restricted. Therefore, thereafter, when the link member 9 is deployed, the pair of upper members 7B,
7B further moves in the separating direction while maintaining the tilt angle, and extends the parison 2 in a tapered shape.
When the upper member 7B is tilted, the spherical portion 7Ac of the lower member 7A is exposed to the outside and the parison 2
Contact

As described above, the tapered elongated parison 50 is formed by the separating operation of the extending members 7, 7 and the tilting operation of the upper members 7B, 7B. Both ends of the extended parison 50 that is in direct contact with 7, 7 are formed to be thick because the fluidity thereof is reduced by the cooling action from the extending members 7, 7 side. Then, the elongated parison 50 formed with such a thick structure is pre-blown to form a pre-blown parison 54, and the pre-blown parison 54 is blow-molded using the molds 3, 3, thereby forming a seat back frame. 61 (see FIG. 9) is formed, but the expanded parison 50 or the pre-blow parison 54 is formed into a shape more similar to the product shape, so that the thick structure of the pre-blow parison 54 is directly used as the product. This is reflected on the seat back frame 61, and the thickness of both ends is maintained as a whole thick despite the tapered shape of the seat back frame 61.

In this embodiment, since the upper members 7B, 7B of the respective extending members 7, 7 are linked to each other as described above, the upper ends of the upper members 7B, 7B are simply formed. In addition to tilting, perform the separating operation at the same time. For this reason, the upper members 7B, 7B including the upper end thereof can be entirely involved in the stretching action. This is because, for example, the upper ends of the upper members 7B, 7B are connected by hinges 8 as in the first embodiment, and the upper members 7B, 7B are only allowed to rotate and are prevented from being separated from each other. This means that there is no need to provide a portion (a portion indicated by reference numeral 7b in FIG. 4) that remains as it is inside the parison 2, so that the extension member 7 can be made more compact.

Third Embodiment FIGS. 15 and 16 show stretching members 7, 7 used in a blow molding apparatus according to the first, third and fourth embodiments of the present invention. . The extension member 7 of this embodiment,
As shown in FIG. 17, a lower part 42a whose left and right ends rise substantially parallel to each other, an intermediate part 42b which rises in a tapered shape continuously from the upper end of the lower part 42a, and a continuous part which is continuous with the upper end of the intermediate part 42b. Frame 42 for the so-called high-back seat, which comprises
15 and 16 are applied to the molding of FIG.
As shown in the upper member 7B made of a supported lower member 7A in the vertical standing state by lifting cylinders 14, the first member 7B ₁ and the second member 7B ₂ Metropolitan which are foldable connected to each other And The first members 7B ₁ and 7B ₁ of the pair of extending members 7 and 7 are connected to each other by the first link member 31 and the second members 7B ₂ and 7B ₂ are connected to each other by the second link member 32. Two link members 31,3
2 are connected to each other by a connecting bar 33, and the connecting pins 34 and 35 of the link members are engaged in the guide elongated holes 19 of the guide member 18 so that the link members 31 and
32 to constitute a parallel link mechanism connecting bar 33 and the pair of second member 7B _2, 7B _2.

Therefore, when the extending members 7, 7 are brought close to each other, as shown in FIG. 15, each of the extending members 7, 7 is linearly opposed to each other and close to each other. When the members 7, 7 are separated from each other, as shown in FIG.
The first members 7B ₁ , 7B ₁ tilt inward in the extending direction in the same manner as the upper member 7B in each of the above embodiments, while the second members 7B ₂ , 7B ₂ The parallel link mechanism is moved in the separating direction while maintaining the parallel state with the lower member 7A by the attitude holding action of the parallel link mechanism.

As a result, the elongate parison 50 stretched and formed by the elongate members 7, 7 has three parts: a wide linear lower part 50a, a tapered intermediate part 50b, and a narrow linear upper part 50c. It becomes a tapered form consisting of parts,
The shape is approximated to the shape of the seat back frame 42 (see FIG. 17) as a product. Therefore,
Like the tapered seat back frame 61 (see FIG. 9) formed by the blow molding apparatus of each of the above-described embodiments, the seat back frame 42 has both ends formed to be thick from the lower end to the upper end. Things.

[0057] In the those in this embodiment, while is not shown the first member 7B ₁ of the lower member 7A and the upper member 7B, the same structure as that of the second embodiment Needless to say, the stopper mechanism (the stopper 24 and the receiving surface 26 in FIG. 14) is provided. Further, in this embodiment, since the first member 7B ₁ and the second member 7B ₂ are prevented from involving a portion of the parison 2 into the corner portion in the case of performing a folding operation to each other, the second Member 7B
₂ of diameter was smaller than that of the first member 7B ₁ provided predetermined step h (see illustration 15) therebetween, the second member 7B after the first member 7B ₁ is tilted to a maximum position ₂ The contact timing of both members with the parison 2 is adjusted so that the side contacts the parison 2.

As described above, the seat back frame 61 or the seat back frame 4 is
2, a technique for saving labor and recycling of an assembling operation when a seat back is manufactured using the seat back frame thus formed, and a seat back frame. A technique for preventing abnormal noise between the pad material and the pad material will be described.

Technology for Labor Saving and Recycling a: Part 1 When a seat back is manufactured by attaching a pad material to a seat back frame of a resin integral molding type, conventionally both are fixed by using a metal fitting. However, in such a case, the fixing work is complicated and the cost is increased, and when the seat back frame is melted and reused, the metal fittings must be removed one by one. This has been a bottleneck in recycling because it must be done.

Therefore, the connection and fixing between the seat back frame and the pad material and the like are performed by a dual lock commonly called a magic tape or the like, thereby enabling labor saving in assembling work and recycling of the seat back frame. It is. Specifically, as shown in FIG. 18, when the seat back frame 61 is blow-molded, a pair of dual lock one-side members 80A, 80A,.
Are mounted, and the one side members 80A, 80A,... Of the dual lock are embedded and fixed in place on the surface of the seat back frame 61 by blow molding. On the other hand, the pad member 78 put on the front side of the seat back frame 61 has a dual-locked other member 8 at an appropriate position.
Are embedded and fixed at the time of integral foam molding of the pad material 78. Further, the seat back frame 61
The other side members 80B, 80B,... Of the dual lock are also attached to the cover member 79 that covers the rear side of. The pad material 78 is provided on the front side of the seat back frame 61.
And fixed by dual locks 80A and 80B, and a cover member 79 is also attached to the back side of the seat back frame 61 to secure the dual locks 80A and 80B.
80B. In FIG. 18, reference numeral 81 denotes a trim material that covers the entire area of the pad material 78 except for the back surface.

With this configuration, it is possible to improve the assembling workability (labor saving) by eliminating the fitting work, improve the disassembling workability (labor saving), and recycle the seat back frame 61. It is something that can be done.

B: Part 2 FIGS. 19 and 20 show the seat back frame 61.
A pad material 78 in a unitary state is fitted and inserted from the upper end side thereof, and a trim material 81 formed in a bag shape is further covered from the upper end side of the pad material 78 and sequentially pulled down. 2 shows a seat back manufactured by mounting. In this case, the seat back frame 61 and the pad member 78 are fixed to the seat back frame 61 by the dual lock one-side members 80A, 80A.
A,... Are performed by arranging the other members of the dual lock on the inner surface of the pad material 78, respectively. The pad material 78
Similarly, the fixing between the trim member 81 and the trim member 81 is performed by the dual lock one side member 80A disposed on the surface of the pad member 78 and the dual lock other side member 80B disposed on the inner surface of the trim member 81.

In this case as well, since it is not necessary to mount the metal fittings as in the prior art, labor saving in assembling work and recycling of the seat back frame 61 can be achieved.

Technique for Preventing Unusual Noise When a seatback is formed by putting a pad material on a seatback frame, when the occupant sits on the seat, the pad material expands and contracts, and a noise is generated between the two. As a means for preventing this, there is a problem that the occupant feels unpleasant as an abnormal noise. As a means for preventing this, conventionally, as shown in FIG. 83, the pad material 78 is buried at the time of integral foam molding, and a coarse felt 82 is further mounted on the pad material 78 so as to prevent abnormal noise between the seat back frame 84 and the pad material 78. .

However, in this case, when the pad material 78 is integrally foamed, urethane penetrates to the surface of a cotton cloth or the like as a reinforcing material. There has been a problem in that the amount of urethane used increases by the amount that penetrates into cotton cloth and the like, resulting in an increase in cost.

Therefore, as shown in FIG. 21, the seat back frame 61 is placed on the surface of the seat back frame 61.
In this case, a reinforcing material 84 such as vinylon cloth is laminated and arranged at the time of blow molding. In such a case, it is not necessary to attach coarse felt or the like as in the related art, and the seat back frame 61 and the pad can be connected without causing a problem such as an increase in the amount of use due to penetration of urethane into the reinforcing material. It is possible to reliably prevent the generation of the squealing noise between the seat back frame 78 and the seat back frame 6.
1 can also improve the strength performance.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an overall configuration of a blow molding apparatus according to a first embodiment of the present invention.

FIG. 2 is an exploded perspective view showing a configuration of a stretching member shown in FIG.

FIG. 3 is an explanatory view of a state before starting a parison stretching operation using the stretching member shown in FIG. 1;

FIG. 4 is an explanatory view of a state in which a parison stretching operation using the stretching member shown in FIG. 1 is completed.

FIG. 5 is a sectional view taken along line VV of FIG. 3;

FIG. 6 is a sectional view taken along line VI-VI of FIG. 4;

FIG. 7 is a front view showing a pre-blow state of the parison.

FIG. 8 is a perspective view showing a molded product removed from a molding die.

9 is a perspective view showing a seat back frame as a product obtained by removing burrs from the molded product shown in FIG.

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

FIG. 11 is a perspective view showing an overall configuration of a blow molding apparatus according to a second embodiment of the present invention.

FIG. 12 is an exploded perspective view of the stretching member shown in FIG.

FIG. 13 is an explanatory view of a state before starting a parison stretching operation using the stretching member shown in FIG. 11;

FIG. 14 is an explanatory diagram of a state at the time of completion of a parison stretching operation using the stretching member shown in FIG. 12;

FIG. 15 is a structural explanatory view of a stretching member in a blow molding apparatus according to a third embodiment of the present invention.

16 is a state change diagram of the stretching member shown in FIG.

FIG. 17 is an overall perspective view of a seat back frame for a high back seat.

FIG. 18 is an exploded perspective view of a seat back provided with a seat back frame formed by using the blow molding device of the present invention.

FIG. 19 is a perspective view from the diagonally rear side showing an assembled state of a seat back provided with a seat back frame molded by using the blow molding apparatus of the present invention.

20 is a perspective view of the seat back shown in FIG. 19 as viewed obliquely from the front.

21 is an enlarged sectional view of a part XXI-XXI of FIG. 18;

FIG. 22 is a cross-sectional view showing an assembled state of a conventional general seat back frame and a pad.

FIG. 23 is a conceptual diagram of a seat back frame having a tapered upper end shape.

FIG. 24 is an explanatory diagram of a parison stretching operation using a blow molding device before improvement according to the present invention.

FIG. 25 is a state change diagram of FIG. 24.

26 is an explanatory diagram of a pre-blow state of the parison shown in FIG. 25.

FIG. 27 is a perspective view of a molded product molded using the parison shown in FIG. 26.

[Explanation of symbols]

1 is an extruder, 2 is a parison, 3 is a molding die, 4 is a blow nozzle (pressurized air supply means), 5 is a pre-pinch panel, 6 is a cylinder, 7 is a stretching member (parison stretching means), and 7A is The lower member, 7B is the upper member, 7a is the contact surface, 8 is the hinge, 9,
31 and 32 are link members, 10 is a pivot pin, 11 is a cooling water passage (temperature adjusting means), 12 is a cooling water supply pipe, 13 is a connecting hose, 14 is a lifting / lowering cylinder, 15 is a contact / separation cylinder, 17 Is a connecting pin, 18 is a guide member, 19 is a guide slot, 20 is a cylinder, 22 is a link housing, 23 is a rod housing, 24 is a stopper, 25 is a stopper receiving groove, 42 and 61 are seat back frames, 50 is an extended parison, 51 is a thick portion, 52 is a thin portion, 54 is a pre-blow parison, 55 is a pre-pinch portion, 57 is a molded product, 58
Is a product portion, 59 is a lower excess portion, and 60 is an upper excess portion.

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Terumi Akazawa 1-6-25 Kunishin, Kaita-cho, Aki-gun, Hiroshima Prefecture Toyo Sheet Hiroshima Plant (72) Inventor Masao Hara Shinchi 3, Fuchu-cho, Aki-gun, Hiroshima Prefecture No. 1 Mazda Co., Ltd. (72) Inventor Takafumi Yamane 2-31 Kabe Minami 2-chome, Asakita-ku, Hiroshima-shi, Hiroshima Prefecture Nishikawa Kasei Co., Ltd. Mitsubishi Yuka Corporation Yokkaichi Research Institute (72) Inventor Takeyuki Uchida 1 Tohocho, Yokkaichi City, Mie Prefecture Mitsubishi Yuka Corporation Yokkaichi Research Institute (56) References JP-A-3-153335 (JP, A) JP-A-4-223130 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B29C 49/00-49/80

Claims (4)

(57) [Claims] 1. An extruder for extruding a thermoplastic synthetic resin material as a cylindrical parison having a predetermined thickness, a lower member and an upper member having predetermined lengths each having a contact surface on an outer surface side, and the contact surface A pair of extension members that are connected to be able to bend in a direction perpendicular to the direction and that are movably supported in the vertical direction and in the bending direction with the lower member standing substantially vertically. Each of the upper members is tilted inward in the opposite direction while being in contact with the inner surface of the parison when the upper member is inserted into the inside of the parison and the parison is extended, while the respective contact surfaces are arranged facing outward. A parison extending means configured so as to be able to perform the operation, a temperature adjusting member for maintaining the temperature of the contact surface of the elongating member at a predetermined temperature lower than the temperature of the parison, Condition And a pressurized air supply means for supplying pressurized air to a parison housed in the molding space of the molding die. Features blow molding equipment. 2. The blow molding apparatus according to claim 1, wherein upper members of a pair of elongating members constituting said parison elongating means are pin-connected at upper ends thereof. 3. The blow molding apparatus according to claim 1, wherein upper members of a pair of elongating members constituting said parison elongating means are connected to each other via a link member at upper ends thereof. 4. The device according to claim 1, 2 or 3, wherein the upper member is divided into a plurality of members in an axial direction thereof, and the plurality of members are connected to each other so as to be bendable.
Blow molding apparatus characterized by being.