JP5636948B2 - Manufacturing method of resin molded products - Google Patents

Description

The present invention relates to a method for producing a resin molded product .

As a method for producing this type of resin molded product, a production method disclosed in Patent Document 1 is known. In this manufacturing method, an arch-shaped frame (a structural member of a vehicle seat) can be manufactured.
The frame body is a resin member that can be attached to a frame member that forms a seat skeleton, and includes a planar body and a rib. The planar body is a mesh-shaped surface member attached to the center of the frame body, and can support an occupant. The rib is a flat reinforcing structure, and can be formed on the back side (the side different from the seating side) of the frame.

In the known technique, the above-described frame body is manufactured using a molding apparatus having a first mold, a second mold, and a cavity. The first mold and the second mold are members that can be closed together, and the cavity is a space formed between the first mold and the second mold.
And after arrange | positioning a planar body between a 1st type | mold and a 2nd type | mold, molten resin is supplied to a cavity and a frame is shape | molded. At this time, the planar body is held in a stretched state in a part of the cavity (the part where the rib is formed), so that the molten resin enters the planar body (mesh mesh) and is solidified. As a result, a part of the planar body (typically, the peripheral edge) is integrally attached to the frame body.

Japanese Patent Laid-Open No. 2002-240081

However, in the known technique, after molding, a part of the planar body may be disposed (exposed) on the back side, and the reinforcing strength of the rib may be slightly reduced. For this reason, the configuration of the known technique is not a configuration that can be easily adopted in consideration of the strength of the resin molded product.
The present invention has been devised in view of the above points, and a problem to be solved by the present invention is to mold a resin molded product while maintaining the strength of the resin molded product as much as possible.

As means for solving the above problems, in the method for producing a resin molded product of the first invention, the resin molded product is produced using a molding apparatus.
The resin molded product has a reinforcing structure such as a planar body, a holding member that holds the planar body, and a rib on one side of the holding member. The molding apparatus includes a first mold, a second mold that can be closed to the first mold, and a cavity formed between the first mold and the second mold.
And after arrange | positioning a planar body between a 1st type | mold and a 2nd type | mold, while supplying molten resin in a cavity, a holding member is shape | molded while integrating a planar body part with a holding member, and holding member In this configuration, a reinforcing structure such as a rib is formed on one surface side. In this type of manufacturing method, it is desirable that a resin molded product can be molded while maintaining the reinforcing strength of the reinforcing structure as much as possible.

Therefore, in the present invention, in the cavity part for molding the reinforcing structure, for example, the molten resin is inclined with respect to the surface of the planar body stretched and from the second mold side toward the surface. emitted, the planar body being displaced in the first mold side by the pressure of the injection of the molten resin (preferably while pressing), the second mold side in a state where extended to contact the inner surface of the first mold side The reinforcing structure was formed.
In this invention, the above-mentioned planar body is integrated with a holding member in the state arrange | positioned at the other surface side of the resin molded product. Thus, the reinforcement structure formed in the holding member one surface side can be maintained suitably by arrange | positioning a planar body in the other surface side of the resin molded product.

  The vehicle seat of the second invention is a method for manufacturing a resin molded product of the first invention, wherein the planar body pressed to the first mold side is cooled below the temperature of the molten resin by the cooling means of the first mold. To do. By cooling the planar body in this way, damage to the planar body due to high temperature during molding can be prevented or reduced as much as possible.

According to the first aspect of the present invention, a resin molded product can be molded while maintaining the strength of the resin molded product as much as possible. Moreover, according to the 2nd invention, the intensity | strength of a resin molded product can be maintained suitably .

It is a perspective view of a vehicle seat. It is a disassembled perspective view of a part of vehicle seat. It is a front view of a supporting member. It is a longitudinal cross-sectional view of a part of the molding apparatus.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to FIGS. In each of the drawings, a reference symbol F is attached to the front of the vehicle seat, a reference symbol B to the rear of the vehicle seat, a reference symbol UP to the vehicle seat and the molding device, and a symbol DW to the vehicle seat and the molding device.

In the present embodiment, a resin molded product (20) is manufactured using a molding apparatus 40 described later (see FIGS. 1, 3, and 4).
Here, the resin molded product (20) has a planar body 20b, a holding member (20a), and a reinforcing structure (34) (details will be described later). And the holding member (20a) of a present Example is a frame-shaped member as a structural member of the vehicle seat 2. As shown in FIG.
As will be described later, after the planar body 20b is disposed between the first mold 41 and the second mold 42, molten resin is supplied into the cavity 44, and a part of the planar body 20b is held by the holding member (20a). The holding member (20a) is formed while being integrated with each other.

At this time, a reinforcing structure (34) such as a rib is formed on one side of the holding member (20a). In this type of manufacturing method, while maintaining the reinforcing strength of the reinforcing structure (34) as much as possible, a resin molded product ( It is desirable that 20) can be molded.
Therefore, in this embodiment, as will be described later, in the cavity part (44E) for molding the reinforcing structure (34), the planar body 20b is pushed away toward the first mold 41 by, for example, the pressure of molten resin injection, The reinforcing structure (34) is formed on the second mold 42 side. Hereinafter, each component will be described in detail by taking a component of the vehicle seat 2 as an example.

[Vehicle seat]
The vehicle seat 2 in FIG. 1 includes a seat cushion 4, a seat back 6, a headrest 8 (all of which are examples of seat constituent members), and a rail member 7. The rail member 7 is a member for sliding the vehicle seat.
The headrest 8 has a pair of stay members 8a, and is attached to the upper portion of the seat back 6 via the support member SM (see FIGS. 1 and 2).

[Seatback]
The seat back 6 is a member that is connected to the seat cushion 4 so as to be able to rise and fall (see FIGS. 1 and 2). The seat back 6 of the present embodiment includes a frame member 6F, a support member 20 (a holding member 20a, a planar body 20b, and a complementary member 60), and a board member 9.
In this embodiment, the support member 20 is attached to the seating side of the frame member 6F, and the board member 9 is attached to the rear side of the frame member 6F.

(Frame member)
The frame member 6F (substantially inverted U shape) has an upper frame 6a, a pair of side frames 6b, a lower frame 6c, and a reclining axis R (see FIG. 2).
The upper frame 6a is a rod-like member (substantially inverted U shape in a front view) that forms the upper part of the seat, and includes a pair of support brackets SB and a linear member 6d. Each of the pair of support brackets SB is a cylindrical member (substantially rectangular) into which the stay member 8a can be inserted. The linear member 6d is a rod-like member bridged to the upper frame 6a (a pair of free ends), and can lock a board member 9 (upper side) described later.
The lower frame 6c is a flat plate member that is bridged between the pair of side frames 6b at the lower part of the seat, and can lock a board member 9 (lower side) described later.

Each of the pair of side frames 6b is a flat plate member that forms a seat side, and is fixed to the lower end (free end) side of the upper frame 6a.
A reclining shaft R is attached in a bridging manner near the lower ends of the pair of side frames 6b. The reclining shaft R is a rotation center when the seat back 6 is tilted (rotated) with respect to the seat cushion 4 and is covered by the shield member Sr (see FIG. 1).
The brackets BL can be fixed to the upper and lower portions of the side frame 6b. The bracket BL is a substantially L-shaped flat plate member, and has a hole H (a through hole into which a screw BS can be inserted) on a side facing a holding member 20a described later (see FIG. 3).

(Board material)
The board member 9 (flat plate shape) has a pair of side piece portions 9b (flat plate shape), a pair of hook portions 9d, and a pair of bracket portions 9c (see FIG. 2).
The pair of hook portions 9d (substantially horizontal J-shaped portions) are portions that can be locked to the linear member 6d, and are provided on the upper surface of the back surface of the board member 9 at a predetermined interval. The pair of bracket portions 9c (substantially inverted L shape) are portions that can be fixed to the lower frame 6c, and are provided at a lower portion of the back surface of the board member 9 at a predetermined interval. And a pair of side piece part 9b is a flat plate part which protrudes in front of a sheet | seat from the side part of the board member 9, respectively, and can coat | cover the sheet | seat both sides partially.
In this embodiment, the board member 9 is attached to the frame member 6F and the rear side of the seat back 6 is covered (see FIGS. 1 and 2).

[Support member]
The support member 20 is a member capable of supporting an occupant, and can be attached to the seating side of the frame member 6F (see FIGS. 1 to 3).
The support member 20 of the present embodiment has a slightly wider outer shape than the frame member 6F, and includes a holding member 20a, a planar body 20b, and a complementary member 60.
The complementary member 60 is a member that complements the periphery of the support member 20, and typically has a skin portion and a cushion material (see FIGS. 1 and 2). The complementary member 60 can support the side of the occupant by projecting toward the front side of the seat at, for example, the side position of the seat (can function as a side support).

(Holding member)
The holding member 20a (an example of a resin molded product) is a frame-like member (arch shape) that can be assembled to the frame member 6F, and is typically made of resin (see FIG. 3).
Here, examples of the material of the holding member 20a include thermoplastic resins (polypropylene, vinyl chloride resin, polyethylene) and thermosetting resins (phenol resin, melamine resin, epoxy resin, urea resin).
The holding member 20a of the present embodiment is hollow at the center and has a basic configuration (an upper frame portion 22, a pair of side frame portions 24, and a lower frame portion 26).
The upper frame portion 22 is a portion forming the upper portion of the holding member 20a, and the pair of side frame portions 24 are portions forming the side portions of the holding member 20a. Further, the lower frame portion 26 is a portion forming a side portion of the holding member 20a, and is a flat plate portion below the holding member 20a in the present embodiment.

The upper frame portion 22 and the side frame portion 24 are substantially L-shaped (in cross-sectional view), and each have an outer frame portion 30, an inner frame portion 32, and a rib 34 (see FIG. 3). .
The outer frame part 30 is a flat plate part constituting the outer shape of the holding member 20a. The inner frame portion 32 is a portion that is bent inward from the outer edge of the outer frame portion 30, and can face the side frame 6b. In the present embodiment, holes H are provided in the upper and lower portions of the inner frame portion 32 so as to face the bracket BL described above (so that the screw BS can be inserted).
The rib 34 (an example of a reinforcing structure) is a flat plate portion erected across the outer frame portion 30 and the inner frame portion 32, and is a configuration for reinforcing the support member 20. A plurality of ribs 34 can be formed at a predetermined interval along the outer periphery of the holding member 20a (in FIG. 3, only some of the ribs are provided with symbols for convenience).

(Planar body)
The planar body 20b is a planar member that elastically supports an occupant, and is preferably a member that can elastically expand and contract (see FIGS. 1 and 2).
The planar body 20b of the present embodiment is a face material having appropriate stretchability, and has a dense property that does not allow the molten resin described later to pass (pass) extremely. Examples of the planar body 20b include a fabric (woven fabric, knitted fabric, non-woven fabric) and a net body (surface material formed by knitting fibers in a mesh shape).
For example, by using a fabric woven and knitted with TPE (thermoplastic elastomer) or PTT (polytrimethylene terephthalate) as the planar body 20b, appropriate stretchability can be imparted. By using a monofilament (single long fiber) of TPE or PTT for the planar body 20b, more suitable stretchability can be imparted.
Further, as the planar body 20b, the air permeability is 400 cc / m ² . A net body of sec or less can be used. The air permeability of the net body can be measured by, for example, a method for measuring the air permeability of a fabric using a Frazier type tester.

[Method of forming support member]
In this embodiment, the planar body 20b is attached to the center of the holding member 20a by the molding device 40 (see FIGS. 2 and 4).
The molding apparatus 40 includes a first mold 41, a second mold 42, a cavity 44, and a cooling means described later. The first mold 41 and the second mold 42 are members that can be closed together (both are substantially rectangular), and a space (cavity 44) is formed between the two members.
The inner surface of the first die 41 has a shape that follows the shape on the seating side of the holding member 20a, and the inner surface of the second die 42 has a shape that follows the shape on the back surface side of the holding member 20a.
The edge 44E of the cavity 44 (part of the cavity for forming the reinforcing structure) has a shape that follows the upper frame portion 22 or the side frame portion 24 (the outer frame portion 30, the inner frame portion 32, and the rib 34). . Here, the rib 34 (an example of a reinforcing structure) can be formed by a recess 48 provided on the inner surface of the second mold 42.
In this embodiment, an injection gate 46 is provided at the edge 44E of the second mold 42 so that the molten resin can be injected into the cavity 44. The injection gate 46 is a hole that vertically penetrates the second mold 42, and can open to the planar body 20 b in the cavity 44 in a face-to-face manner.

(Cooling means)
Here, in this embodiment, the first mold 41 can be provided with a cooling means to cool the first mold 41 below the temperature of the molten resin.
The cooling means is configured to maintain the first mold 41 below the temperature of the molten resin (for example, maintain at 30 ° to 40 °). For example, the first mold 41 itself can be air-cooled or water-cooled, and various cold insulating materials can be attached to the first mold 41. Also, the first mold 41 can be heated to a temperature lower than the molten resin.

With reference to FIG. 4, the planar body 20 b is stretched in the cavity 44 when the holding member 20 a (made of resin) is molded.
At this time, the first mold 41 is closed while the planar body 20 b is stretched on the inner surface side of the second mold 42. Next, a planar material 20b is integrally attached while molding the holding member 20a by pouring a molding material (such as molten resin) from the injection gate 46 into the cavity 44.
In this embodiment, the molten resin is injected only into the edge 44E of the cavity 44 without injecting the molten resin into the central portion 44C of the cavity 44. By doing so, the planar body 20b can be exposed at the center of the holding member 20a while the retaining member 20a is formed in an arch shape on the periphery of the planar body 20b.

In this embodiment, the planar body 20b is pressed against the first mold 41 side by the molten resin injection pressure at the edge 44E of the cavity 44. The planar body 20b extends moderately and contacts the inner surface of the first mold 41. Thus, the planar body 20b can be arrange | positioned by pressing the planar body 20b against the 1st type | mold 41 on the seating surface side (other surface side different from one surface) of the holding member 20a.
Furthermore, in the present embodiment, the planar body 20b is pressed against the first mold 41 to be cooled below the temperature of the molten resin by a cooling means (not shown). By cooling the planar body 20b in this manner, damage (deterioration such as fiber breakage) of the planar body 20b due to high temperature during molding can be prevented or reduced as much as possible.

[Vehicle seat assembly work]
With reference to FIG.1 and FIG.2, the supporting member 20 is assembled | attached with respect to the frame member 6F. At this time, the hole H of the bracket BL and the hole H of the holding member 20a are overlapped while the holding member 20a is covered on the seating side of the frame member 6F. The holding member 20a can be attached to the side frame 6b by inserting the screws BS in both hole portions.
Next, the board member 9 is assembled to the frame member 6F. At this time, the board member 9 is disposed on the rear side of the frame member 6F while overlapping the side frame portion 24 and the side piece portion 9b. Then, the pair of hook portions 9d are locked to the linear member 6d, and the pair of bracket portions 9c are fixed to the lower frame 6c.

As described above, in the present embodiment, the above-described planar body 20b is integrated with the holding member 20a in a state of being disposed on the seating surface side of the holding member 20a. Thus, by arranging the planar body 20b on the seating surface side of the holding member 20a, the reinforcing strength of the ribs 34 formed on the back surface side of the holding member 20a can be suitably maintained.
Further, in this embodiment, by cooling the planar body 20b at the time of molding the holding member 20a, damage to the planar body 20b due to a high temperature during molding can be prevented or reduced as much as possible .

The vehicle seat of the present embodiment is not limited to the above-described embodiment, and can take other various embodiments.
(1) In the present embodiment, the rib (flat plate) is exemplified as the reinforcing structure, but the configuration of the reinforcing structure is not intended to be limited. For example, a columnar (boss) or lattice-shaped reinforcing structure can be formed on the holding member.
(2) Moreover, in this embodiment, the example which presses the planar body 20b against the 1st type | mold 41 was demonstrated. At this time, the reinforcing strength of the ribs can be relatively maintained even by pushing the planar body toward the first mold (by approaching the first mold).
(3) Moreover, in this embodiment, although the shaping | molding apparatus 40 using the 1st type | mold 41 and the 2nd type | mold 42 was used, the shaping | molding apparatus which has a 1st type | mold, a 2nd type | mold, and an intermediate | middle type | mold can also be used. In the present embodiment, the first mold is disposed on the second mold. However, the second mold can be disposed on the first mold (can be disposed upside down).

(4) Moreover, in this embodiment, the example (simple structure) which pushed away the planar body 20b to the 1st type | mold 41 side with the injection pressure of molten resin was demonstrated. Unlike this, the planar body 20b can be pushed away to the first mold 41 side by the vacuum suction part provided in the first mold. Moreover, the planar body 20b can also be pushed away to the 1st type | mold 41 side with the press member provided in the 2nd type | mold. In this embodiment, the planar body 20b (part or all) can be pressed against the first mold 41 side by the pressure of injection of the molten resin.

(5) Moreover, in this embodiment, when the planar body 20b has moderate intensity | strength, it is not necessary to provide a cooling means in the 1st type | mold 41. FIG.
(6) In the present embodiment, the holding member 20a of the seat back 6 has been described as an example of a resin molded product. The configuration of the present embodiment can be applied to various seat components such as a seat cushion. Moreover, the structure of a present Example is applicable to the various resin molded products which have a planar body and a reinforcement structure.

2 Vehicle seat 4 Seat cushion 6 Seat back 6F Frame member 8 Headrest 9 Board member 20 Support member 20a Holding member 20b Planar body 34 Rib (reinforcing structure)
40 Molding device 41 First mold 42 Second mold 44 Cavity 44E Cavity edge 44C Cavity center 46 Injection gate 48 Second mold recess 60 Complementary member

Claims (2)

In a method for producing a resin molded product that produces a resin molded product using a molding device,
The resin molded product has a reinforcing structure such as a planar body, a holding member that holds the planar body, and a rib on one side of the holding member;
The molding apparatus has a first mold, a second mold that can be closed to the first mold, and a cavity formed between the first mold and the second mold,
After the planar body is disposed between the first mold and the second mold, molten resin is supplied into the cavity, and the holding member is integrated with the retaining member while integrating a part of the planar body. And forming a reinforcing structure such as a rib on one side of the holding member,
In a part of the cavity forming the reinforcing structure, the molten resin is injected from the second mold side in an inclined direction with respect to the surface of the stretched planar body and toward the surface, and the surface shaped body is being pushed away to the first mold side by the pressure of the molten resin, elongating the resin molding configuration for molding the reinforcement structure to the second type side in a state of contact with the inner surface of the first mold side Product manufacturing method.   The method for producing a resin molded product according to claim 1, wherein the planar body pressed against the first mold side is cooled to a temperature lower than the temperature of the molten resin by the cooling means of the first mold.

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