JP3773588B2 - Epidermis for headrest and manufacturing method thereof - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a skin used for a headrest mounted on an upper part of a seat back of a vehicle or the like and a method for manufacturing the same.
[0002]
[Prior art]
A headrest is attached to an upper end of a seat back of an automobile or the like for comfort. The skin for headrests includes those that are sewn using fabric or genuine leather, those that are made by Zolslash molding, and those that are made by blow molding.
In the blow-molded skin, there are two types, a seamless type (conventional technology 1) and a so-called split stomach type (conventional technology 2). According to the headrest manufacturing method according to the prior art 1, a stay with a core is set in a blow mold to form a bag-like skin, then transferred to a foaming mold, and a foam raw material is injected into the skin to perform foam molding. I finished with a headrest.
On the other hand, according to the headrest manufacturing method according to the prior art 2, only the bag-shaped skin is first molded, then the bottom of the skin is cut with a cutter or the like to form a stay with a core and a foaming material inlet, and then with a core The stay was built into the skin, and then the foam material was injected into the skin to finish the headrest by foam molding.
[0003]
[Problems to be solved by the invention]
However, in the prior art 1, when the headrest is made, the setting of the stay with the core body to the blow mold at the time of blow molding is unexpectedly troublesome (40 seconds to 45 seconds / piece), the molding man-hour is increased, and the product cost is high. It was.
On the other hand, in the prior art 2, since the bottom of the skin is cut with a cutter or the like to form the stay with the core and the foaming material injection port, the foaming material often leaks from the cut part during foam molding. Even after wiping and removing the leaked portion, the trace remained and the appearance was poor.
[0004]
The present invention solves the above-mentioned problems, and is a method of manufacturing a headrest that finishes blow molding and later incorporates a stay with a core into the skin, but the assembly work is simple, and a stay with a core with a cutter or the like. , It is an object of the present invention to provide a skin for a headrest that eliminates foaming material leakage during foam molding and a method for manufacturing the same, without the need to cut the foaming material inlet.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, the gist of the present invention described in claim 1 is that a parison hanging from a die head has a pin shaft for forming a pair of stay holes and a funnel formed integrally with the bottom of the skin. A method for producing a skin for a headrest is characterized in that a blow mold is closed by inserting a nozzle, and then blow molding is performed by blowing air from the nozzle into the blow mold.
According to a second aspect of the present invention, there is provided a method of manufacturing a skin for a headrest, wherein the pin shaft is disposed in a direction in which the pin shaft extends out of the mold from a cavity forming a skin bottom surface when the blow mold is closed. An annular recess surrounding the pin shaft and a band-like space surrounding the pin shaft are formed via an annular recess that narrows the bottom surface of the annular recess.
A skin for a headrest according to a third aspect of the invention includes a funnel provided on the bottom surface of the skin, a stay hole portion where the stay protrudes outward from the bottom surface of the skin, a band portion substantially equal to the outer diameter of the stay, A strip for a headrest is characterized in that a band-shaped portion extending through a thin portion and having a hollow portion provided between the stay and the stay is integrated by blow molding.
[0006]
As in the first aspect of the present invention, when a pin shaft for forming a pair of stay holes and a nozzle for forming a funnel integrated with the bottom surface of the skin are included, the blow mold is closed, and blow molding is performed. The bottom surface of the blow-molded skin has stay holes and a funnel for injecting the foaming raw material, so that it does not have to be cut later with a cutter or the like. And since only a required part is opening, there is little possibility that a foaming raw material will leak out of an outer skin by foam molding. Also, in the foam molding stage, it is convenient because the foaming raw material can be injected into the skin using a funnel.
In the present invention, the stay hole is formed, and the stay with the core body is assembled into the skin later using the stay hole, but the shape of the stay with the core body is limited. However, a stay with a core used for a headrest of an automobile has recently been frequently bent in a “U” shape, and there is no problem as long as the stay with a core is used.
As in the second and third aspects of the invention, in the mold closing of the blow mold, the band-shaped space is formed through the annular recess and the biting protrusion in the direction in which the pin shaft extends out of the mold from the cavity forming the skin bottom surface. When the foam is formed, not only the band part that winds the outer peripheral surface of the stay but also the band part that extends from the band part across the thin part is formed on the bottom surface of the skin. The foam material that leaks through the stay is limited. In addition, even if there is a foam material that leaks beyond the band portion and the thin wall portion to connect the stay, the foam material accumulates in the cavity. And the foaming raw material accommodated in the cavity is solidified and removed together when the strip is removed at the stage of commercialization of the final headrest.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of a skin for a headrest and a method for manufacturing the same according to the present invention will be described in detail.
1 to 6 show an embodiment of a method for manufacturing a headrest skin according to the present invention. FIG. 1 is a longitudinal sectional view of a blow mold in a mold open state, and FIG. 2 is a perspective view of a receiver positioned below FIG. 3 is an enlarged cross-sectional view around the pin shaft when the blow mold of FIG. 1 is closed, FIG. 4 is a longitudinal cross-sectional view of the blow mold opened after forming the skin for the headrest, and FIG. 4 is a partially enlarged perspective view of the bottom surface of the blow-molded skin shown in FIG. 4, and FIG. 6 is a longitudinal sectional view around the band portion.
[0008]
Prior to the headrest skin and the manufacturing method thereof, first, the blow mold B for molding the headrest skin 1 will be described.
The blow mold B includes a split mold 4, a receiver 5, and a die head 6 (FIG. 1).
The split mold 4 forms a cavity α of the headrest skin 1 when the mold is closed. It is a split type with a two-part configuration that opens in the left and right side directions. In the blow mold B, in addition to forming the cavity α of the skin body portion in the mold closed state, the stay 21 extends from the cavity α forming the skin bottom surface to the outside of the skin. The pin shaft 54 ( An annular recess 41 is formed around (described later). Then, a projection 42 that approximates a so-called biting projection is narrowed down so that the bottom surface of the annular depression 41 is brought close to (or abuts) the pin shaft 54. A band-like space 43 is formed on the side. The lower surface of the belt-like space 43 has the cutting projection 44 squeezed so that the tip thereof is close to (or abuts on) the pin shaft 54.
The portion from the annular recess 41 in FIG. 3 to the belt-like space 43 has an axisymmetric shape formed concentrically with respect to the axial direction of the pin shaft 54.
[0009]
The support 5 is configured such that a nozzle 53 is placed in the middle of a plate-like body 55 supported by an air cylinder 52 via a block 51, and the pin shafts 54 and 54 are fixed upright on both sides thereof (FIG. 2).
The nozzle 53 forms the funnel 14 integrated with the bottom surface of the skin, and has a shape in which a short tube is welded to the tip of the truncated cone. The nozzle 53 also serves as an air outlet 531 for inflating the compressed air by blowing it into the parison in the mold after the mold is closed.
The pin shaft 54 is for forming the stay hole 16 on the bottom surface of the skin, and is made of a pipe (which may be a round bar) substantially equal to the outer diameter of the stay 21.
The receiver 5 moves up and down as the piston rod 521 moves forward and backward by the operation of the air cylinder 52. When the receiving tool 5 is disposed at the upper point position and the mold is closed, the blow mold B is configured to sandwich the pin shaft 54 and the upper half of the nozzle 53 (FIGS. 1 and 4). The tip of the pin shaft 54 and the nozzle 53 is inserted into the parison P by blow molding.
The die head 6 is positioned above the receiving member 5 and pushes out and supplies the semi-molten cylindrical parison P.
[0010]
Production of the skin for the headrest starts from the blow-opened state of the blow mold B as shown in FIG.
A parison P in a semi-molten state is supplied from the die head 6. A thermoplastic resin (here, vinyl chloride resin) plasticized by an extruder (not shown) is extruded from the die head 6 as a cylindrical parison. The parison P hangs until the lower end of the parison covers the pin shafts 54 and 54 and the nozzle 53 of the receiver 5.
[0011]
After securing such a state, the left and right split dies 4a and 4b are then closed. By this time, the air cylinder 52 is operated, and the receiving member 5 is arranged at the upper point position. In this way, the blow mold B is closed by holding the pin shafts 54 and 54 and the nozzle 53 in the parison P.
The split mold 4 forms the cavity α of the skin body by closing the mold. As described above, the annular recess 41, the protrusion 42, the belt-like space 43, and the biting protrusion 44 are formed around the pin shaft, and the parison P is interposed there.
[0012]
After completion of mold closing, air is supplied into the parison from the nozzle 53 of the receptacle 5 for forming the funnel 14. Compressed air of about 0.5 to 1.1 MPa enters the block 51 through the conduit 9 and blows out from the air outlet 531.
Due to the injection of the compressed air, the parison P sandwiched between the blow molds B swells, is welded and fixed to the cavity surface 46 of the blow mold B, and is shaped into a shape along the mold surface. Since the melt-extruded parison P is blow-molded before being cooled, it is in close contact with the mold surface.
[0013]
A skin 1 for a headrest is obtained by the blow molding, and the skin 1 is provided with a band portion 11, a thin portion 12 and a belt-like portion 13 in a stay hole portion where a stay 21 projects outward from the skin 1. 4 and 5).
The band portion 11 is formed by the annular recess 41, and the band portion 13 is formed by the band-shaped space 43. Then, the protrusion 42 forms the thin part 12 and separates the band part 11 and the band-like part 13.
The band portion 11 has an inner diameter substantially equal to the stay outer diameter so that the stay 21 can be tightened literally. However, in blow molding, it is difficult to control the inner diameter, and leakage of the foam raw material to the outside of the skin can be considered during the foam molding process. Therefore, in the present invention, the hollow portion 131 of the band-like portion 13 is used for measures against leakage of the foaming raw material (described later). The belt-like portion 13 is thin as shown in FIG. 6, and the hole diameter of the bottom surface is substantially equal to the outer diameter of the stay, but the main body portion is larger than the outer diameter of the stay, and the cavity 131 exists.
Further, a trumpet-shaped funnel 14 is integrally formed at a substantially intermediate position between the pair of stays 21 and 21 on the bottom surface of the skin 1. Since the nozzle 53 that forms the funnel 14 is used as the air outlet 531 for blow molding, the funnel 14 inevitably communicates with the bag-shaped skin.
Thereafter, the shaped semi-molten resin is cooled and solidified.
[0014]
Thereafter, the mold is opened (FIG. 4), and after demolding, the variros that has been divided by the biting projection 44 is removed. The scraping bag portion 19 is easily removed by the biting projection 44.
Thus, a desired skin 1 for the headrest as shown in FIG. 5 can be obtained around the band portion where the whole is as shown in FIG. 7 and the stay 21 protrudes outward from the skin 1. Reference numeral 15 indicates a trace of the parting portion.
[0015]
The skin 1 manufactured as described above is incorporated into a headrest as a final product, and the procedure is as follows.
First, the U-shaped stay 2 is inserted into the skin 1 (FIG. 7). One stay 21 of the U-shaped stay 2 is inserted from the hole 132 of the band-shaped portion 13 into the skin through the thin-walled portion 12, the band portion 11, and the stay hole 16. Then, while turning the tip of the stay 21, the stay tip 211 is made to reach the other stay hole 16, and the stay hole 16, the band portion 11, the thin portion 12, the belt-like portion 13 are passed through and taken out from the outer skin (see FIG. 8).
Next, with the stay 21 facing up, the skin 1 with the U-shaped stay 2 inserted is set in the foaming mold 7 (FIG. 9).
The foaming mold 7 is divided in half so that the skin 1 is housed in the cavity β and the band part 11, the thin part 12, the band-like part 13, and the vertical half of the lower part of the stay are provided in the foaming mold 7. Fit into the recessed part. The recess is composed of a band hole 75, a band-shaped hole 74, and a stay lower hole 76. The band-shaped part hole 74 (or the band part hole 75) includes a part in which the thin part 12 is accommodated.
Here, the size of the band portion holes 74, although there is greater margin of strip-shaped portion 13, the for the band section bore 75, the diameter of which is made in smaller than the diameter D ₂ of the band portion 11 made of blow molding Is preferred. This is because when the band part 11 is fitted into the half part, the half part becomes a shape to fasten the band part 11. The band part 11 is made of a resin skin and is somewhat elastic so that it can be contracted and pushed into the band part hole 75.
Since the inner diameter of the band portion 11 varies, the stay 21 is held by positioning means (not shown).
[0016]
Subsequently, the foam mold 7 is closed. The other half part of the foaming mold 7 (not shown) has the same shape as the above-mentioned half part, and when the mold closing of the foaming mold 7 is completed, the two half parts related to the foaming mold 7 become the band part 11. Will tighten all around.
Thereafter, a liquid foam raw material (for example, liquid urethane foam raw material) is poured from the funnel 14 into the skin, and the foam 3 is formed by foam molding.
Here, as described above, it is difficult to manage the inner diameter in blow molding, and a gap may be formed between the inner diameter of the band portion 11 and the outer diameter of the stay 21. Even if the band part 11 is tightened by the band part hole 75, there is a foaming raw material that attempts to go beyond the band part 11 and go out of the skin in the foam molding process. In the present invention, in consideration of such variation in the inner diameter of the band portion, even if the foaming raw material goes out of the skin, the foaming raw material is suppressed by the cavity 131 of the belt-like portion 11. The foaming material that has leaked due to increased foaming pressure is contained in the cavity 131 and does not stain the skin 1 or the stay 21. In the case of a liquid material such as a foaming raw material, the pressure drops suddenly when a small amount of liquid is removed. Therefore, it is sufficient that the cavity 131 needs a space that can hold the amount of liquid.
Thus, foam curing is finished, cooled, and the headrest as shown in FIG. 10 is taken out by demolding.
Finally, the strip 13 and the funnel 14 are removed from the skin 1, and a desired headrest is completed. The strip 13 is easily removed with the thin portion 12 as a boundary. And if the strip | belt-shaped part 13 is removed, it will leak in a foam molding process, and the foaming raw material accommodated in the cavity part 131 and solidified will also be removed cleanly.
[0017]
The method for manufacturing the headrest skin configured in this way is to assemble a stay with a core to the skin 1 later, and at first glance, the stay with a core is set in a blow mold B to manufacture a bag-shaped skin. Compared to prior art 1, it seems to take time. However, the U-shaped stay 2 can be used to easily assemble the headrest later on the skin 1 and finish it into a headrest.
First, the distal end portion 211 of the U-shaped stay 2 is generally tapered, and the stay distal end portion can be easily inserted into the hole 132 of the band-shaped portion 13. When the stay 21 is inserted into the skin as it is, the conical portion of the belt-like portion 13 leads to the band portion 11. The stay interval of the U-shaped stay 2 and the distance between the stay holes 16 and 16 are naturally the same, and there is no difficulty in making the stay tip 211 reach the other stay hole 16. And the stay front-end | tip part 211 passes through the stay hole 16-the strip | belt-shaped part 13 as it is, and comes out of the outer skin. In fact, it has been confirmed that this assembly can be completed in only 5 seconds.
Further, the U-shaped stay 2 assembled to the outer skin 1 wobbles at two points if only the band portions 11, 11 provided around both stay holes, but the stay 21 also exists in the hole portion 132 of the band-shaped portion 13. Is supported, and the U-shaped stay 2 is stabilized. Therefore, the work of foam molding in the subsequent process is also facilitated.
[0018]
Further, in the foam molding stage, the set failure of the U-shaped stay 2 is reduced by increasing the stay contact area of the band portion 11 to the belt-shaped portion 13 and increasing the mechanical joining force in the thin-walled portion 12. Further, since the band portion 11 is formed on the skin 1, leakage from the stay hole portion at the foam molding stage can be suppressed. The foaming mold 7 (specifically, the halved part) fastens the band part 11 so that the foaming raw material hardly leaks out of the skin. Further, due to the difficulty in managing the inner diameter of the band part in blow molding, it is conceivable that the foaming raw material passes through the band part 11. Even in such a case, the cavity 131 contains the foaming raw material. The skin design surface is not soiled.
On the other hand, since the funnel 14 is formed by the nozzle 53, it is easy to inject the foam raw material into the skin in the foam molding.
Of course, the U-shaped stay 2 is assembled later on the skin 1, but the stay hole 16 and the foaming material injection port which must be provided in the skin 1 are formed together by the pin shaft 54 and the nozzle 53 in the blow molding process. Therefore, it is not necessary to cut the skin bottom with a cutter or the like as in the prior art 2. Therefore, the trouble that the foaming material leaks out from the cut portion at the time of foam molding, and further, the man-hour to cut by the cutter or the like can be solved.
The stay with the core body is limited to the U-shaped stay 2 having the same diameter as the stay, but the core body portion 22 connecting the stays 21 and 21 sufficiently serves as the core body. Recently, the U-shaped stay 2 is frequently used for the stay with the core, and the method of manufacturing the skin for the headrest of the present invention is very useful.
[0019]
The present invention is not limited to those shown in the above-described embodiments, and various modifications can be made within the scope of the present invention depending on the purpose and application. The shape, size, and the like of the skin 1, the U-shaped stay 2 (stay with a core), the foam 3, the split mold 4, the receiver 5, the die head 6, and the foam 7 can be appropriately selected depending on the application. The headrest can be applied to any headrest such as a perforated headrest. At that time, the stay with the core body is slightly deformed from the U-shaped stay.
[0020]
【The invention's effect】
As described above, according to the skin for the headrest of the present invention and the manufacturing method thereof, the stay with the core body is a rear assembly, but the stay hole, the foaming material injection port, etc. can be cut with a cutter. It is easy to assemble the stay, and exhibits excellent effects in improving productivity and quality.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view of a blow mold in a mold open state in an embodiment of a method for producing a skin for a headrest of the present invention.
FIG. 2 is a perspective view of a receiving member located below FIG.
3 is an enlarged cross-sectional view around a pin axis when the blow mold of FIG. 1 is closed. FIG.
FIG. 4 is a longitudinal sectional view showing a state in which a blow mold is opened after molding a skin for a headrest.
FIG. 5 is a partially enlarged perspective view of the bottom surface of the blow-molded skin of FIG. 4;
FIG. 6 is a longitudinal sectional view around a band part.
FIG. 7 is a perspective view showing a state in which a U-shaped stay is inserted into the epidermis.
FIG. 8 is a perspective view showing a state in which a U-shaped stay is inserted into the epidermis.
FIG. 9 is a partial perspective view showing a state in which the epidermis with the U-shaped stay of FIG. 8 is set in a foaming mold.
10 is an overall perspective view of a foam molded product that has been subjected to foam molding with the foam mold of FIG. 9 and has been removed from the mold.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Skin 11 Band part 12 Thin part 13 Strip part 131 Cavity part 14 Funnel 16 Stay hole 21 Stay 41 Annular depression 42 Protrusion 43 Band space 53 Nozzle 54 Pin shaft 6 Die head B Blow type P Parison

Claims (3)

A parison that hangs down from the die head includes a pin shaft for forming a pair of stay holes and a nozzle for forming a funnel integrated with the bottom of the skin, and the blow mold is closed. A method for manufacturing a skin for a headrest, wherein blow molding is performed by blowing air into a blow mold. When the blow mold is closed, the pin shaft is inserted through an annular recess surrounding the pin shaft in a direction in which the pin shaft extends out of the mold from the cavity forming the skin bottom surface, and a projection for narrowing the bottom surface of the annular recess. The manufacturing method of the skin for headrests of Claim 1 with which the strip | belt-shaped space which surrounds was formed. Along with the funnel (14) provided on the bottom surface of the skin, a stay hole portion where the stay protrudes outward from the bottom surface of the skin is provided with a band portion (11) substantially equal to the outer diameter of the stay and a thin portion extending from the band portion. A skin for a headrest, wherein a band-like portion (13) in which a hollow portion is provided between the stay and the stay is integrated by blow molding.

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