JPH03270923A - Resin seat back frame and forming method thereof - Google Patents

Abstract

PURPOSE:To contrive to improve the strength and rigidity of the seat back frame concerned by a method wherein the direction of orientation of fibrous filler is selected so as to correspond to the direction of the tensile stress applied to the seat back frame having the structure supported by one-sides knuckle. CONSTITUTION:A knuckle 2 is mounted on one side at the lower end of a resin seat back frame 10, on the other side of which a free hinge 3 is mounted. In the frontal wall part 10a of the seat back frame, fibrous filler 11 consisting of glass fiber or the like is filled. Since these fillers 11 are orientated diagonally upwards by the angle of about 45 deg. from the side 10c, on which a knuckle 2 is mounted, the direction of the tensile stress generated in the seat back frame 10 having the structure supported by one-sided knuckle and the direction of orientation of the fibrous filler 11 fall in line with each other. Thus, flexural elastic modulus becomes larger, resulting in allowing to improve the strength and rigidity of the seat back frame 10.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a resin seat back frame for an automobile and a method for molding the same.

(Prior Art) An automobile seat structure having a hollow resin seat back frame manufactured by blow molding a hard synthetic resin material has been known for a long time, as disclosed in, for example, Japanese Utility Model Application No. 62-75916. ing.

In order to increase its strength and rigidity, such resin seat back frames are filled with fibrous filler made of glass fiber or the like. oriented.

On the other hand, in a reclining automobile seat, the seat back frame is reclinably attached to the seat cushion frame by a reclining knuckle (hereinafter simply referred to as "knuckle"), and
Movement in the rotational direction is regulated by an angle adjustment device included in this knuckle. In such a seat, in order to reduce both weight and cost, as shown in FIG. 11, one-sided knuckle support is provided where the knuckle 2 is provided only on one side of the seat back frame 1, and the other side is simply a free hinge 3. Many structures are now being used.

By the way, in the case of the seat back frame 1 having the one-sided knuckle support structure as described above, the movement in the rotational direction is restricted by the knuckle 2 at the lower end of the - side of the frame. As shown, when a load is applied to the seatback frame 1 from the front side, a tensile stress is applied diagonally upward from the portion where the knuckle 2 is attached to the front wall portion 1a, and the seatback frame 1 is It is known that compressive stress in the same direction acts on the back wall portion 1b. When this seat back frame 1 is a resin molded product, synthetic resin has high rigidity against compressive stress, but its rigidity against tensile stress is not so high. In order to improve this, special consideration must be given to tensile stress.

(Object of the Invention) Therefore, the present invention aims to improve strength and rigidity by selecting the orientation direction of the fibrous filler in accordance with the direction of tensile stress applied to the seat back frame with one side knuckle support structure. The purpose of the present invention is to provide a seat back frame and a method for molding the same.

(Structure of the Invention) The resin seat back frame according to the present invention is characterized in that the front wall is filled with a fibrous filler oriented obliquely upward from the side where the knuckle is attached. do.

Further, in the first molding method of the resin seat back frame according to the present invention, the fibrous filler in the part of the parison that becomes the front wall of the seat back frame after molding is applied to the side part of the front wall where the knuckles are attached. The parison is extruded from an extruder so as to be oriented obliquely upward from the corresponding side, and then the parison is sandwiched between molds in an upright position and blow molding is performed.

Furthermore, a second resin seat back frame according to the present invention
The molding method is to extrude the above-mentioned parison from an extruder so that the orientation direction of the fibrous fibers in the parison is vertical, and then to the knuckle attachment side of the part of the parison that will become the front wall of the seat back frame after molding. It is characterized in that blow molding is performed by sandwiching the above-mentioned parison between molds that are inclined to the corresponding sides.

(Effects of the Invention) In the resin seat back frame according to the present invention, the front wall of the resin seat back frame is filled with a fibrous filler that is oriented diagonally upward from the side of the knuckle. The direction of tensile stress generated in the seat back frame of the knuckle support structure matches the orientation direction of the fibrous filler, which increases the bending elastic modulus and improves the strength and rigidity of the seat back frame.

Further, according to the method for molding a resin seat back frame according to the present invention, it is possible to easily align the orientation direction of the fibrous filler in the front wall of the seat back frame with the direction of tensile stress generated in the front wall. Because you can
A seat back frame with high strength and rigidity can be obtained.

(Embodiments) Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

IO in FIG. 1 indicates a resin seat back frame according to the present invention, and a knuckle 2 is attached to one side of the lower end of the frame, and a free hinge 3 is attached to the other side. The front wall portion 10a of the seat back frame 10 is filled with a fibrous filler 11 made of glass fiber or the like, and these fillers 11 are diagonally upward at an angle of about 45° from the side portion 10c on which the knuckle 2 is attached. is oriented towards.

FIG. 2 is a schematic diagram of a molding device for molding the seat back frame 10, and 12 indicates a cylindrical parison made of thermoplastic resin that is extruded downward from an extruder 13. 14 and 15 are blow molding molds, and 16 is a blow bin.

FIGS. 3(A) to 3(C) are explanatory diagrams of the parison extrusion process. The cylindrical parison 12 hangs down in the vertical direction while rotating, but the fibrous filler 11 has a spiral shape as shown in FIG. The filler 11 in the region 12a which is oriented in the direction of the front wall 10a and becomes the front wall 10a of the seat back frame 10 after the parison 12 is formed is
The knuckle 2 is attached to the side part 12 corresponding to the side part 10c.
It is extruded from the extruder 13 so as to be oriented obliquely upward at an angle of about 45° from c. Such a parison 12 is placed in a blow molding mold 14 shown in FIG.
15, heated and softened, and then blowing air into the parison 12 through the blowbin 16,
The parison 12 is brought into close contact with the inner wall of the mold 14, 15, whereby a hollow seat back frame 10 as shown in FIG. 1 can be obtained.

5 and 6 are diagrams schematically showing the configuration of an extruder 13 for obtaining a parison 12 in which the fibrous filler material 1 is oriented in an oblique direction, and 17 is a cylindrical shape having a vertical axis. , 18 is a ring-shaped die, 19 is a parison 12, and 18 is a ring-shaped die, and 19 is a ring-shaped gap 2 between the core 17 and the die 18.
This is a piston for pushing out the parison 12 from 0. A large number of guide walls 21 are formed on the inner circumferential surface of the die 18 at an angle of about 45 degrees in a predetermined direction with respect to the axis of the core 17, and the resin material pressed by the piston 19 is moved as shown in FIG. As shown by the arrow in FIG. A parison 12 is obtained in which the particles are helically oriented.

The following FIGS. 7 and 8 are diagrams schematically showing the configuration of an extruder 13 equipped with a plurality of divided cylinders 22 in order to orient the fibrous filler 11 in an oblique direction. That is, as is clear from FIG. 8, a plurality of divided cylinders 22 each having a piston 23 are arranged in the upper part of the core 17 with their axes inclined at about 45 degrees in a predetermined direction with respect to the axis of the core 17. arranged around it. By extruding the resin material by synchronizing the pistons 23 of each divided cylinder 22 with each other, the resin material flows at an inclination of about 45° to the vertical direction, as shown by the arrow in FIG. 12 is extruded while rotating, and the fifth
Similarly to the case of using the extruder 13 shown in FIGS.
Parison 12 in which fibrous filler 11 is spirally oriented
will be obtained.

9 and 10, an extruder 13 is used to obtain a parison 12 in which the orientation direction of the fibrous filler 11 is vertical, as in the conventional extruder 13.
is used, but the direction of the blow molding mold 14.15 is approximately 45°.
A case is shown in which a molded product in which the fibrous filler 11 is oriented in an oblique direction is obtained by installing the mold at an angle and clamping the mold.

In this case, the part of the parison 12 that will become the front wall 10a of the seat back frame 10 shown in FIG. 1 after molding is tilted approximately 45 degrees to the side corresponding to the knuckle attachment side (to the left in FIG. 10). By installing the molds 14 and 15, the knuckles can be attached to the front wall 10a on the side 10.
It is clear that a seat back frame 10 is obtained which is filled with fibrous filler 11 oriented obliquely upward at an angle of about 45° from c. The seat back frame 10 filled with the fibrous filler 11 oriented at an angle of approximately 45 degrees has a bending elastic modulus of 1 compared to the seat back frame 10 in which the filler is oriented in the vertical direction.
．． It turned out to be 5 to 2 times as much.

[Brief explanation of drawings]

FIG. 1 is a front view of a resin seat back frame according to the present invention, FIG. 2 is a schematic diagram of a molding apparatus used for molding the seat back frame shown in FIG. 1, and FIGS.
) is an explanatory diagram of the parison extrusion process, FIG. 4 is a perspective view of the parison, FIG. 5 is a schematic sectional view of the extruder used in carrying out the present invention, FIG. 6 is a perspective view of the die, and FIG. 7 8 is a schematic cross-sectional view showing the configuration of another extruder used in carrying out the present invention, FIG. 8 is a perspective view of its divided cylinder, and FIGS. 9 and 10 are explanatory diagrams of other molding methods of the present invention. , 1st
1 to 14 are a perspective view, a front view, a side view, and a rear view, respectively, of a conventional seat back frame. 1. lO... Seat back frame 2... Knuckle 3... Free hinge 11.
...Fibrous filler 12...Parison 13...Extruder 14.1
5... Blow molding mold 16... Blow bin 17... Core 18... Die 19... Piston 21... Guide wall
22...Divided cylinder 23...Divided piston

Claims (1)

[Scope of Claims] 1. In a hollow resin seat back frame with a one-sided knuckle support structure in which a reclining knuckle is attached only to one side, a seat is provided on the front wall portion diagonally upward from the side on which the reclining knuckle is attached. A resin seat back frame characterized by being filled with oriented fibrous filler. 2. A method for molding a hollow resin seat back frame having a one-sided knuckle support structure in which a reclining knuckle is attached only on one side, wherein a fibrous filler is used in a parison portion that becomes the front wall of the seat back frame after molding. The parison is extruded from the extruder so as to be oriented obliquely upward from the side of the front wall corresponding to the side on which the reclining knuckle is attached, and then the parison is sandwiched between molds in an upright position and blow molded. A method for molding a resin seat back frame, characterized by performing the following steps. 3. A method for molding a hollow resin seat back frame with a one-sided knuckle support structure in which a reclining knuckle is attached only to one side, the parison being extruded from an extruder so that the orientation direction of the fibrous filler in the parison is vertical. Then, after molding, the parison is sandwiched between a mold that is inclined toward the side corresponding to the reclining knuckle attachment side of the part of the parison that will become the front wall of the seat back frame, and blow molding is performed. Molding method for manufactured seat back frames.