JPH10146882A - Blow molding method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To smoothly and accurately insert a functional member having a width dimension larger than the inner diameter of a cylindrical parison formed by extrusion into the cylindrical parison to position and hold the same at the expected position within a molded product. SOLUTION: A heater panel 4 is inserted into a cylindrical parison 6 having an inner diameter smaller than the width dimension of the heater panel 4 in a folded posture along with a pair of the extension pins 3a, 3b supporting the heater panel and a pair of the extension pins 3a, 3b are mutually separated to be displaced to expand the width of the parison 6 to deform the parison 6 into a flat cylindrical shape. Further, the heater panel 4 is returned to the initial form and pre-blow is applied to the flat cylindrical parison and, thereafter, the mold clamping and molding to the parison are performed and the heater panel 4 is integrated with the molded product.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a blow molding method for manufacturing a blow molded product having a functional member therein, and for example, when a seat portion and a backrest portion of a chair are blow molded, predetermined positions inside the chair portion and the backrest portion are formed. In addition, the present invention relates to a blow molding method suitable for use for positioning and holding a heating element, a passage forming member for a temperature adjusting medium, and the like.

[0002]

2. Description of the Related Art In blow molding, liquid,
Filling with powders, granules and other substances having no fixed shape has been widely and generally performed, but at the same time as blow molding a functional member such as a heating element having a specific size and shape, Positioning and holding the molded product at a predetermined position has not yet been put to practical use.

[0003]

For example, when a molded article is manufactured by extrusion blow molding, the thickness of a functional member having a specific size and shape, as well as the width, are not limited to a cylindrical shape extruded from an extrusion die. When the inner diameter of the parison is smaller than the inner diameter of the parison, the functional member can be reliably taken into the parison by positioning the functional member in the extrusion molding path of the cylindrical parison. It is possible to properly incorporate the functional member into the molded product by tightening and molding.

However, in this case, it is necessary to make the width of the functional member smaller than the inner diameter of the cylindrical parison. For example, the functional member is a heater panel or other heating element, and the molded article is formed. When the chair is relatively large, such as a seat or backrest, the relative width of the heating element of the heater panel to the seat or backrest is small, no matter how large the inner diameter of the cylindrical parison is formed. As a result, the seat portion, the backrest portion, and the like cannot be heated uniformly over the entire portion.

The present invention advantageously solves the above-mentioned problems. It is an object of the present invention to make the width of a functional member such as a heating element far larger than the inner diameter of a cylindrical parison. It is still another object of the present invention to provide a blow molding method capable of securely accommodating the functional member in a parison and reliably positioning and holding the functional member at a required position.

[0006]

According to the blow molding method of the present invention, a functional member having a width larger than the inner diameter of the parison is formed by bending or folding the parison in accordance with the extrusion of the cylindrical parison. A pair of extension pins that are supported in a split state are inserted into a cylindrical parison together with its functional members, and then the pair of extension pins are displaced from each other to expand and deform the cylindrical parison into a flat shape. The elastic member is returned to its initial form, and the lower end of the flat cylindrical parison is pinched, and the parison is pre-blowed.Further, the mold is clamped and molded on the pre-blown parison, The functional member is integrated with the molded product.

In this molding method, a functional member having a predetermined shape and dimensions is set in a curved posture, a folded posture, or a divided state, so that the diameter of a circumscribed circle is smaller than the inner diameter of the parison, and the function of the parison is reduced. The functional member is supported by a pair of extension pins located at an interval smaller than the inner diameter of the parison, and based on the downward displacement of the cylindrical parison, both the functional member and the pair of extension pins are smoothly and The cylindrical parison can be reliably inserted into the cylindrical parison, and the pair of extension pins are separated and displaced to expand and deform the cylindrical parison into a flat shape having a required width. The parison, by returning to its form, in other words, it is in a form sufficient to perform its intended function , It is possible to sufficiently secure the occupation space required for the functional member.

[0008] Thereafter, pre-blow to a parison whose lower end is pinched, followed by mold clamping and molding are sequentially performed, and at an appropriate time, the functional member is integrated with a molding material in a required manner. The functional member can be easily and reliably positioned and held inside the blow molded product, and the functional member having a predetermined shape and dimensions is
The function can be exerted on the molded article sufficiently uniformly over the whole.

By the way, the integration of the functional member into the molded product is performed by clamping at least a part of the functional member between the parisons with a molding die when clamping the pre-blown parison. Can be performed by locally sandwiching the functional member between the front side portion and the back side portion, and the adhesive provided on at least one surface of the functional member during molding after mold clamping. This can be done by fusing the layer to its inner surface, depending on the temperature of the molding material pressed into contact therewith, in any case ensuring that the functional member remains in the expected position can do. And this is more remarkable when both of the above are used in combination.

Another method of integrating the functional member is to partially or entirely sandwich the functional member between the front side portion and the back side portion of the molding material during molding after mold clamping. According to this method, a functional member having a particularly large thickness can be positioned and held as expected in the same manner as in the method described above.

Here, the functional member may be a relatively thin heating element, a composite material of the heating element and a heat insulating layer laminated on one side of the heating element, or a temperature control medium. It is particularly effective to use a passage constituting member.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic perspective view of an essential part showing an embodiment of the present invention in the case where a heater panel as an example of a heating element is installed in a seat of a chair as a blow molded product.

[0013] Here, at a position below a pair of molds 1a and 1b that define a molding cavity, guided by respective long holes 2a and 2b provided in the guide plate 2, in a direction approaching and separating from each other. A pair of relatively displaceable extension pins 3a and 3b are provided, and the heater panel 4 in the folded posture is attached to the respective extension pins 3a and 3b via a tape 4b made of the same material as the blow molding material. To support. In this case, the folding attitude heater panel 4 when the extension pins 3a and 3b are brought closest to each other, the circumscribed circle diameter to both the extension pins 3a and 3b including the extension pins 3a and 3b is extruded from the extrusion die 5. It has a dimension smaller than the inner diameter of the parison 6.

Further, as shown in the figure, the heater panel 4 is also supported on the guide plate 2 by a separate support pin 7 fixed or fixed at the center portion in the width direction of the heater panel 4. When the support pin 7 is used, it is possible to guide the lead wire, which has come into contact with the heater panel 4 in advance, through the hollow portion formed in the support pin 7, so that the lead wire can be led out of the chair seat as a molded product. .

In this arrangement of the heater panel 4, when the parison 6 is formed by extrusion from the extrusion die 5 and its lower end is gradually displaced downward, the heater panel 4 and the extension pins 3a and 3b in the folded posture are respectively displaced. , Smoothly and surely enter the inside of the parison 5. Therefore, thereafter, when the lower end of the cylindrical parison 6 is sufficiently close to the guide plate 2, the extrusion of the parison 6 is temporarily stopped, and both extension pins 3a, 3b are inserted into the long holes 2a, 2b, respectively. Along with this, the cylindrical parison 6 is widened and deformed into a required flat cylindrical shape, and the heater panel 4 is expanded to its initial shape.

FIG. 2 is a perspective view of a main part showing such a widened deformation state of the parison. Here, a pair of extension pins 3a and 3b move the cylindrical parison 6 without obstructing the expansion of the heater panel 4. Further, since the heater panel 4 is deformed into the widened parison 6a having a width sufficient to accommodate the heater panel 4 in the expanded state, the heater panel 4 has a function form in the parison 6a sufficient to perform a predetermined function. That is, an initial form can be secured.

Thereafter, the pair of pinch plates 8a and 8b disposed somewhat above the guide plate 2 are advanced and displaced so as to sandwich the widened parison 6a. The side portion and the back side portion are mutually fused. Here, both pinch plates 8a, 8b
Have notches at positions corresponding to the extension pins 3a, 3b and at positions corresponding to the support pins 7, respectively.
At positions other than the positions corresponding to, the respective portions on the front side and the back side of the widened parison 6a are directly fused to each other.

Next, the parison 6a is pre-blown by blowing a small amount of air into the widened parison 6a from an appropriate position thereof, so that the parison 6a is uniformly extended and deformed as shown in FIG. Brings
Thereafter, the pair of molds 1a and 1b are clamped, and air is also blown from an appropriate position into a parison portion sandwiched between the molds 1a and 1b, thereby bringing the parison portion into close contact with the inner surface of the mold. By doing so, the molding is performed in a shape that exactly follows the molding cavity, and then, by cooling and curing the molded part, a series of blow molding operations on the seat of the chair is completed, and the inside of the seat The heater panel 4 is installed at a required position and integrated therewith.

In the mold clamping and molding steps, it is not inconvenient for the support pins 7 of the heater panel 4 to be integrated with the seat, which is a molded product. And a groove (not shown) that allows the support pin 7 to enter the molding cavity. On the other hand, each extension pin 3
Since a and 3b need to be subsequently withdrawn from the molded article and reused, the mold 1 under the state where the extension pins 3a and 3b are most separated from each other is used.
In clamping the molds a and 1b, both pins 3a and 3b are positioned outside the dies 1a and 1b in the width direction.

FIG. 4 is a view showing this from the back side of one mold 1b. The extension pins 3a and 3b are located outside the clamped molds 1a and 1b. Therefore, the pins 3a and 3b can be easily removed from the molded product. Here, the heater panel 4 is connected to the extension pins 3a, 3b.
The tape 4b made of the same material as the molded product, which functions to support the molded product, is sandwiched between the molds, and is fused and integrated with the molded product.

After the blow molding of the seat has been completed as described above, the molds 1a and 1b are opened, and each of the extension pins 3a and 3b is extracted from the molded product in a required order. In addition, by removing the support pins 7 from the guide plate 2 or cutting the support pins 7 in the middle thereof, the seat as a molded product is taken out.

In the case where the seat portion is blow-molded in this way, in order to make the integration of the heater panel 4 into the seat portion more reliable, at least a part of the heater panel 4 is shown in FIG. As shown in the drawing, three portions A, B, and C of the peripheral portion of the heater panel 4 are clamped together with the widened parison 6a in the pair of dies 1a and 1b in the die clamping process. And as a result,
These parts A, B and C are sandwiched between parisons.

FIG. 6A is a view showing the bottom surface of the seat portion 11 formed in this manner. The hatched portion in the figure is particularly large, and FIG. 6B is a longitudinal sectional view. As shown, the heater panel 4 can be positioned and held by firmly sandwiching the heater panel 4 between the seat panel 11 and the front surface side portion 11a.

FIG. 7 shows a parison 6a of the heater panel 4.
FIG. 7 is a view similar to FIG. 6 showing another embodiment of a sandwiching portion between the heater panel 4 and the heater panel 4.
, Can be positioned and held sufficiently firmly.

The heater panel 4 is integrated with the seat portion 11 by, for example, bonding an adhesive layer provided on one surface of the heater panel 4 at the time of blow molding after closing the molds 1a and 1b. It can also be performed by fusing to the inner surface based on the temperature of the molded part before cooling, and according to this, as shown in a vertical sectional view in FIG. Since the gap between the side portion 11a and the side portion 11a is sufficiently buried with the adhesive layer 12 and the gap functioning as a heat insulating layer can be effectively removed from the space between the side portion 11a and the heater panel 4, the heater panel 4 It is also possible to increase the efficiency of heat transfer from the panel 4 to the seat surface.

Accordingly, when the heater panel 4 is fused to the front side portion 11a of the seat portion 11 by the adhesive layer 12, as described above, when the heater panel 4 is sandwiched between the parisons, 4 can realize more robust positioning and holding, and can sufficiently increase the heating efficiency of the seat surface.

Further, the seat 11 of the heater panel 4
As another integration method, the heater panel 4 is directly or, as shown in a longitudinal sectional view in FIG. 9, the heater panel 4 is attached together with the heat insulating layer 13 laminated on the back side thereof. There is a method in which the heater panel 4 is sandwiched between the front side portion 11a and the back side portion 11b of the portion, and this also firmly positions and holds the heater panel 4 at a predetermined position in the seat portion 11. be able to. Here, when the heater panel 4 is laminated on the heat insulating layer 13 as shown in FIG. 9, the heat transfer from the heater panel 4 to the back side of the seat 11 is effectively prevented to heat the seat surface. There is an advantage that the efficiency can be increased.

As described above, when blow molding the seat portion 11 of the chair, the heater panel 4 is inserted into the cylindrical parison 6 as a folded form thereof, and the heater panel 4 is placed inside the seat portion 11. Although the respective cases of integration are described, the heater panel 4 can be inserted into the cylindrical parison with its curved posture as shown in FIG. 10.
1 (a) is a passage forming member 1 for a temperature control medium.
As shown in FIG. 11 (b), the heat medium or the refrigerant supplied from the fluid supply port 14 a may be defined by the passage constituting member 14. By flowing through the flow path 14b, the surface side portion 11a of the seat portion 11 can be effectively heated or cooled,
Further, when the passage constituting member itself is made of a heat insulating material, heat loss to the back side of the seat portion 11 can be effectively prevented.

Here, as described with reference to FIG. 9, the passage forming member 14 and the seat 11 are integrated with each other.
Blow molding after completion of the mold clamping of a and 1b can be performed by sandwiching the passage constituting member 14 between the front side portion 11a and the back side portion 11b of the seat.

By the way, when a relatively thick functional member like the passage constituting member 14 is inserted into the cylindrical parison 6 formed by the extrusion die 5, the passage constituting member 14 is moved. For example, as shown in FIG. 12 (a), the front and rear direction dividing surfaces provided at the center in the width direction and the outer sides in the width direction of the respective partition walls 14c that define the flow path 14b are divided into four in the width direction. At the same time, the central portion 14d of the front end wall is divided from the bottom portion, and the portions adjacent to each other across the front-rear dividing surface are connected to each other by a hinge tape 14e.
As shown in (b) and (c), each partition 14c is tilted outward in the width direction, and the front end wall central portion 14d is formed.
By projecting them outwards in a chevron, this can be done to provide a sufficient reduction in overall width.

It should be noted that the path constituting member 1 thus folded is
As described above, the return of the extension member 4 to the initial state in the parison is performed smoothly and reliably by the mutual displacement of the extension pins 3a and 3b supporting the passage constituting member 14 via the tape 4b. Done in

Here, a relatively thick functional member that can function as a passage constituting member, a heat insulating material, or the like,
In the case of having a plate-like or other simple initial form, it is divided into a plurality of required members, and these divided parts are interconnected by hinge tapes 14e. , (B), by relatively displacing it into an appropriate bent shape,
The width dimension can be reduced as required.

Although the preferred embodiment of the present invention has been described with reference to the drawings, three or more molding dies can be used as a set to define a required molding cavity, and a chair back can be formed. It is needless to say that the same functional member can be molded in the same manner as described above even when the same functional member is provided in the portion.

[0034]

As is apparent from the above description, according to the present invention, a functional member having a width larger than the inner diameter of a cylindrical parison is formed in a cylindrical parison extruded by an extrusion die. Based on the support of the extension pins, the extension pins can be inserted smoothly, reliably, and accurately, and the functional member can be initially moved to the position where the extension pins are sufficiently displaced by the separation displacement of the extension pins. It can be surely returned to its shape, and its functional members are integrated into the desired position of the molded product by clamping, fusing, etc., so that it can be positioned and held in the molded product. Can be performed firmly with high reliability, and the functional member can exert its function sufficiently uniformly over the entire molded article.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view of an essential part showing an embodiment of the present invention.

FIG. 2 is a perspective view of a main part showing a state in which a functional member returns to an initial form.

FIG. 3 is a schematic perspective view showing a pre-blow state with respect to a widened parison.

FIG. 4 is a rear view showing a mold clamping state of the mold.

FIG. 5 is a plan view illustrating a holding portion of the heater panel.

FIG. 6 is a plan view showing a state in which the heater panel is integrated into a seat.

FIG. 7 is a plan view showing another integrated state of the heater panel with the seat.

FIG. 8 is a longitudinal sectional view showing another integrated form of the heater panel to the seat.

FIG. 9 is a longitudinal sectional view showing still another integrated form of the heater panel to the seat.

FIG. 10 is a perspective view showing a support state of the heater panel in a curved posture.

FIG. 11 is a longitudinal sectional view showing another type of functional member and its integrated state with a seat.

FIG. 12 is a view showing a divided state of a passage constituting member and a folded state thereof.

FIG. 13 is a diagram showing an example of reducing the width of the thick simple functional member.

[Explanation of symbols]

 1a, 1b Mold 2 Guide Plate 2a, 2b Slot 3a, 3b Extension Pin 4 Heater Panel 5 Extrusion Die 6 Cylindrical Parison 6a Wide Parison 7 Support Pin 8a, 8b Pinch Plate 11 Seat 12 Adhesive Layer 13 Heat Insulating Layer 14 Passage Component member 14a Fluid supply port 14b Channel A, B, C portion

Claims (7)

[Claims] When manufacturing a blow-molded article having a functional member inside, the functional member is bent and folded with the extrusion of a cylindrical parison having an inner diameter smaller than the width of the functional member. Or, a step of inserting a pair of extension pins supported in a divided state together with the functional member into a cylindrical parison, and displacing the pair of extension pins from each other,
Along with widening deformation of the cylindrical parison into a flat cylindrical shape,
A step of returning the functional member to its initial form, a step of pinching the lower end of the flat cylindrical parison, and a step of pre-blowing the parison, and performing mold clamping and molding on the pre-blown parison. And a step of integrating the functional member into a molded article. 2. The blow according to claim 1, wherein the integration of the functional member into the molded product is performed by clamping at least a part of the functional member between the parisons when clamping the pre-blown parison. Molding method. 3. The method according to claim 1, wherein the integration of the functional member into the molded product is performed by fusing an adhesive layer provided on the surface of the functional member to the inner surface of the molded material during molding after mold clamping. 3. The blow molding method according to 1 or 2. 4. The method according to claim 1, wherein the integration of the functional member into the molded product is performed by sandwiching the functional member between the front side portion and the back side portion of the molded material during molding after mold clamping. Blow molding method. 5. The blow molding method according to claim 1, wherein the functional member is a heating element. 6. The composite material comprising a heating element and a heat insulating layer laminated on one side of the heating element.
The blow molding method according to any one of the above. 7. The blow molding method according to claim 1, wherein the functional member is a member constituting a passage for a temperature adjusting medium.