JPH07255557A - Chair shell structure - Google Patents

Abstract

PURPOSE:To facilitate processes subsequent to molding by preventing damage to locking projections or slots, and preventing resin foam from leaking from the slots when a cushion is molded on one side of an inner shell. CONSTITUTION:Each of slots 18 bored through an inner shell 11 to accommodate locking projections 17 protrusively provided to an outer shell 12 has its cushion 13 side end blocked by a blocking wall, and so when the cushion 13 is molded on one side of the inner shell 11, resin foam is kept from entering the slots, and the need for removing the resin foam around the slots 18 after molding is eliminated. In use, no load is applied directly to the locking projections 17 from the side of the cushion 13, and the locking projections 17 and the edges of the slots 18 that fit over the projections are in no danger of being damaged.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shell structure applied to a seat plate or backrest of a chair, and more particularly to a chair shell structure having an improved middle shell made of a hard elastic material such as synthetic resin.

[0002]

2. Description of the Related Art Conventionally, as a shell structure applied to, for example, a backrest of a chair, a middle elastic shell made of a hard elastic material such as synthetic resin and having a cushion material mounted on the front surface and a back surface of the middle shell are covered. A structure is known in which an outer shell that is attached to the unit is integrally joined (Example: Actual Kaihei 5-1
354).

In such a shell structure, the surfaces of the shells to be joined are often formed into a curved surface. Therefore, when joining these shells, the curved surfaces of both molded shells are matched. Is important.

Conventionally, in the case where the outer shell is attached to the inner shell formed of a hard elastic material such as a synthetic resin as described above, for example, as shown in FIG. 6, hook portions are provided at a plurality of positions on one side surface of the outer shell (2). The engaging projection (5) having the (6) is projected, the fitting hole (3) is provided in the middle shell (1), and the engaging projection (5) is inserted into the fitting hole (3). It is like this.
Then, the hook portion (6) is attached to the locking claw (4) provided near the fitting hole (3).
The engagement projection (5) is prevented from coming off from the fitting hole (3) by locking the shell, and the shells (1) and (2) are coupled to each other.

[0005]

In such a conventional structure, with the outer shell (2) attached to the inner shell (1), the fitting hole (3) is formed on the cushion material mounting portion side of the inner shell. When the tip of the engaging projection (5) protrudes from the seat, and when a load is applied from the cushion material side such as sitting on a chair and backrest, the engaging projection (5)
Load is applied directly to the tip of the engaging projection (5) or the fitting hole
The edge of (3) may be damaged, or the engaging projection (5) may come off from the fitting hole (3). Also, for long-term use,
The tip of the engaging projection (5) protruding from the fitting hole (3) is repeatedly pressed against the cushion material, and the cushion material is damaged.

Further, the inner shell (1) is set in a mold for the cushion material, and an unfoamed undiluted solution of a foaming synthetic resin is injected into the mold to foam, and the cushion material is molded on one surface of the middle shell (1). For molding, middle shell (1) during foaming
Since the foamed resin leaks from the fitting hole (3) of the above and fills the fitting hole (3), the engaging protrusion (5) of the outer shell (1) cannot be inserted as it is, and after foaming, the middle shell (1) It was necessary to remove the foamed resin around the fitting hole (3), and the post-treatment after molding was troublesome.

The present invention has been made in view of such circumstances, and it is possible to prevent the engagement projection or the fitting hole from being damaged and to fit the foamed resin when the cushion material is molded on one surface of the middle shell. An object of the present invention is to provide a chair shell structure which does not leak from the holes and can be easily post-processed after molding.

[0008]

In order to achieve the above-mentioned object, the present invention (Claim 1) provides a middle shell having a cushioning material for a seat or a backrest mounted on one side, and another middle shell. For a chair having an outer shell that covers the side surface, and by engaging an engaging projection formed on the outer shell with a fitting hole formed in the inner shell, the middle shell is coupled to the outer shell. In the shell structure, the end of the fitting hole on the cushion material side is closed by a closing wall.

The closing wall is preferably integrally formed with the middle shell so as to bulge from the middle shell to the cushion material side.
(Claim 2). Further, the engaging projection has a hook portion projecting to both sides at the tip end thereof, and the hook portion is engaged with a pair of elastic locking pieces provided in the opening of the fitting hole on the outer shell side. Therefore, it is preferable to prevent it from coming off from the fitting hole (claim 3).

[0010]

When the cushion material is molded on one surface of the middle shell, the foamed resin penetrates into the fitting hole by closing the end of the fitting hole formed in the middle shell on the cushion material side with the closing wall. This eliminates the need to remove the foamed resin around the fitting hole after molding, and the load from the cushioning material side is not directly applied to the engaging protrusions during use. There is no possibility of damaging the edge of the fitting hole with which is engaged.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. As shown in FIG. 1, the chair shell structure of this embodiment is applied to, for example, a backrest of a chair,
Middle shell made of hard elastic material such as synthetic resin in which a cushion material (13) made of foamed resin such as urethane is molded on one side
It has (11) and an outer shell (12) which is attached to cover the other side surface of the inner shell (11).

The outer peripheral side portion of the middle shell (11) is divided into a plurality of portions in the circumferential direction by the dividing lines (14) formed in a radial pattern, and the divided outer peripheral side portions are independently formed in the central side portion. It is supposed to be able to bend.

As shown in FIG. 1, the dividing line (14) is a middle shell.
It may be a score line or slit formed from the outer peripheral end side of (11) toward the center side, or may be a thin portion formed from the outer peripheral end side of the middle shell (11) toward the center side.
(Not shown).

A fitting holding hole (15) for setting the middle shell in the upper mold of the foaming mold is formed in the central portion of the middle shell.

A receiving portion (16) as a connecting portion for integrating with the outer shell (12) is provided on the divided outer peripheral side portion of the inner shell (11), while the outer shell (12) has a receiving portion (16). Engaging projections (17) are provided on the opposite surface, and these receiving portions (16) and engaging projections (1)
Both shells (11), (12) through the mating connection consisting of
Are integrally connected to each other.

That is, as shown in FIG. 2, the receiving portion (16) has a plurality of rectangular fitting holes (1) into which the engaging protrusions (17) can be inserted.
8) and the opening of the fitting hole (18) on the outer shell (12) side, which are inclined inward toward each other toward the cushion material (13), and whose tip is the tip of the engaging projection (17). And a pair of elastic locking pieces (19) for engaging with a hook portion (22) described later to prevent the engaging projection (17) from coming off from the fitting hole (18).

The fitting hole (18) is a cushion material for the middle shell (11)
(13) It is closed by a closing wall (18a) protruding toward the mounting surface side, and the closing wall (18a) is formed by bulging from the middle shell (11) by integral molding.

The elastic locking piece (19) has a thin portion (19a) protruding outward from the opening of the fitting hole (18) in an arc shape, and the thin portion (19).
Locking part (19b) inclined from a) toward the inside of the fitting hole (18)
The elastic locking pieces (19) are arranged such that their opposite ends are parallel to each other.

On the other hand, the engaging projections (17) are composed of a pair of opposing walls (17a),
(17a) and the end wall (17b) integrally connected to the opposing walls (17a) and (17a) have a U-shaped cross section, and the reinforcement is continuously provided on the outer peripheral side of the end wall (17b). Reinforced by ribs (23).
Then, on both sides of the tip of the engaging projection (17), a hook portion (22) having arrow-shaped inclined end edges (22a), (22a) protruding in a large-diameter brim shape is integrally formed, and the hook portion (22 Both inclined edges of () are parallel to each other and come into contact with the tip of the elastic locking piece (19) of the middle shell (11). Although not shown, the cross section of the engagement protrusion may be H-shaped.

According to this embodiment having such a structure, when integrally mounting the cushion material (13) on the inner shell (11), the outer shell side portion of the inner shell (11) is divided into a plurality of parts. Good flexibility can be achieved by making each section flexible.

That is, as shown in FIG. 5, a middle shell (11) is set in a foam type upper mold (30) such as urethane, and is placed between the upper mold (30) and the lower mold (31). When the cushioning material (13) and the inner shell (11) are integrated by injecting a foaming undiluted solution such as urethane to foam the urethane foam, even if the inner shell (11) is deformed due to molding, etc. In the foaming process such as
The outer peripheral portion of the middle shell (11) is first subjected to a foaming pressure of urethane or the like, and the divided outer peripheral side portions are bent and pressed against the upper mold. Therefore, during molding of the cushion material (13), urethane or the like that is foaming does not wrap around between the middle shell (11) and the upper mold (30), and the fitting hole (attachment part for attaching to the outer shell ( It is possible to prevent the occurrence of defects such as filling up 18) and the elastic locking piece (19).

In particular, since the end of the fitting hole (18) on the cushion material (13) side is closed by the closing wall (18a), the foamed resin does not enter the fitting hole (18). There is no need to remove the foamed resin around the fitting hole (18) after molding.

At the time of assembly, an elastic locking piece in which the hook portion (22) of the engaging projection (17) of the outer shell (12) is provided at the opening of the fitting hole (18) of the middle shell (11) The shells (11) and (12) are pressed against each other in this state in conformity with (22). In this case, the fitting hole
Since the pair of elastic locking pieces (19) provided in the opening of (18) are in the shape of a letter V and are inclined toward the inside of the fitting hole (18), as shown in FIG. , The hook (22) of the engaging protrusion (17) is
9) is pushed out and inserted in a state of overcoming this, and the hook portions (22) on both ends of the engaging projection (17) are locked by the elastic locking pieces (19) on both sides.

At this time, the elastic locking piece (19) has the locking portion (19b).
Is connected to the opening of the fitting hole (18) through the thin portion (19a), the thin portion (19a) is elastically deformed,
The engagement protrusion (17) can be easily inserted into the fitting hole (18).

During use, the load of the user sitting on the chair leans against the load, and the middle shell (11) or outer shell
Even if (12) is deformed, the elastic locking piece (19) is mainly
9a) elastically deforms to engage the engaging projection (17)
The relative movement with respect to (18) is allowed, the engagement protrusion (17) is not subjected to a large load and is broken, and the middle shell (11) may rattle against the outer shell (12). Absent.

Further, by making the opposite ends of the elastic locking piece (19) parallel to each other, and by making both side surfaces of the engaging projection (17) abutting the tip of the elastic locking piece (19) parallel. The contact area between the tip of the elastic locking piece (19) and the engaging projection (17) can be made large, and the engaging projection (17) can be reliably held by the elastic locking piece (19).

Further, the engaging projection (17) is a pair of parallel facing walls (17a), (17a) and an end wall (17b) integrally connected to the facing walls (17a), (17a). Since the cross section is U-shaped or H-shaped in cross section, the strength of the engaging protrusion (17) can be improved, and breakage and the like can be effectively prevented.

In the present embodiment, the hook portion (22) has the closing wall (1
It is inserted into the fitting hole (18) with 8a). As described above, on the cushion material mounting side of the middle shell (11), the hook portion (22) and the fitting hole (18) at the tip of the engaging projection (17) are covered with the closing wall, and thus the cushion material (13 ) And the tip of the engaging projection (17) do not come into direct contact with each other. Therefore, when a load is applied from the cushion material (13) side such as a backrest while sitting on a chair, the tip of the engaging protrusion (17) and the hook portion (22) of the tip portion
No load is applied to the elastic locking piece (19) via the, and the engagement protrusion (17) or the elastic locking piece (19) is damaged or
(17) will not come off from the elastic locking piece (19).

In the long-term use, the cushion material (13)
Is not repeatedly pressed against the tip of the engaging projection (17), and the cushioning material (13) is not damaged. In addition,
Although the structure of the present invention is applied to the backrest of the chair in the above-mentioned embodiment, it is needless to say that it can be applied to the seat of the chair in the same manner as described above.

[0030]

As described above, according to the present invention, since the engaging projection is inserted into the fitting hole with the closing wall, the tip of the engaging projection on the cushion material mounting side of the middle shell and the tip thereof. Since the hook portion and the engaging portion on the fitting hole side are covered with the closing wall, the tips of the engaging protrusions do not come into direct contact with the cushion material. Therefore, when a load is applied from the cushion material side such as a backrest while sitting on a chair, the load is not applied to the tip of the engaging protrusion, and the edge of the engaging protrusion or the fitting hole with which the engaging protrusion engages. There is no risk of damage to the fitting or disengagement of the engaging projection from the fitting hole. In addition, when used for a long period of time, the cushioning material is not repeatedly pressed against the tips of the engaging protrusions, and the cushioning material is not damaged, which is an excellent effect.

[Brief description of drawings]

FIG. 1 is a perspective view before assembly showing an embodiment of the present invention.

FIG. 2 is an enlarged view showing an assembled state of FIG.

FIG. 3 is a cross-sectional view showing a state in which a shell is being connected in the embodiment.

FIG. 4 is a sectional view showing a shell connection state of the embodiment.

FIG. 5 is a cross-sectional view showing a shell-molded state in the example.

FIG. 6 is a partially enlarged cross-sectional view showing a conventional example.

[Explanation of symbols]

 (11) Middle shell (12) Outer shell (13) Cushion material (16) Receiving part (17) Engagement protrusion (22) Hook part (18) Fitting hole (18a) Closure wall (19) Elastic locking piece ( 19a) Thin part (19b) Locking part

Claims (3)

[Claims] 1. A middle shell having a cushioning material for a seat or a backrest mounted on one side surface, and an outer shell covering the other side surface of the middle shell. In a chair shell structure in which an inner shell is joined to an outer shell by engaging an engaging projection provided on a shell, the cushion material side end of the fitting hole is closed by a closing wall. The shell structure for chairs. 2. The shell structure for a chair according to claim 1, wherein the closing wall is integrally formed so as to bulge from the middle shell to the cushion material side. 3. The engaging projection has a hook portion projecting to both sides at a tip portion thereof, and the hook portion is engaged with a pair of elastic locking pieces provided at an opening of the fitting hole on the outer shell side. The shell structure for a chair according to claim 1 or 2, wherein the chair shell structure is configured so as to be prevented from coming off from the fitting hole by being fitted together.