JPH0321937Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Field of Application) This invention relates to a mold for a cushion body having a hole in a portion for inserting a headrest stay.

(Prior Art) Depending on the purpose of the cushion body, a cushion body is used in which a hole is partially provided for mounting parts, etc. For example, it is a cushion body that is provided with a hole for attaching a stay to a headrest of a vehicle seat, or an operating lever that changes the angle of the seat.

FIG. 6 is a perspective view of a main part of a cushion body 12 (vehicle backrest) having such a hole 10.

As shown in the figure, this back cushion body 12 usually consists of a substantially rectangular cube having a predetermined thickness, so there is a hole for inserting the head rest stay.
0 is provided toward the longitudinal direction of the cushion body 12 from one end.

On the other hand, most of these cushion bodies 12 are made of molded soft polyurethane foam, and when molding them, the back surface of the cushion body 12 is aligned with the bottom surface of the cavity, that is, the lower surface, as shown in FIG. A horizontally placed split mold 14 such as the one shown in FIG. This is because when polyurethane foam is molded, the injected raw material rises inside the cavity 16 as it foams, but if the depth of the cavity 16 is too large, the density of the lower layer may vary or the time required for foaming may become longer. This is because the gas generated at that time is difficult to escape, and gas accumulation etc. are likely to occur in the cushion body 12. In contrast,
By configuring the mold in such a way that the cushion body 12 is placed horizontally as described above, the depth of the cavity 16 of the split mold 14 can be reduced, which can eliminate the above-mentioned drawbacks, and the opening of the cavity 16 can be enlarged, allowing the material to be This is because the injection machine head can be moved according to the opening thereof, and a uniform cushion body 12 which eliminates the above-mentioned disadvantages can be formed.

However, in the case where the cushion body 12 has the hole 10 on one side in the longitudinal direction as described above, the protrusion 18 for forming the hole 10 is inserted into the cavity 1.
6, the protrusion 18 forms an undercut with respect to the split surface of the split mold 14,
After molding, the cushion body 12 is locked and held in the cavity 16 by the protrusions 18, so that when demolding the cushion body 1
2 must be forcibly removed from the cavity 16 by utilizing its deformability. the result,
The protrusion 18, ie, the hole 10 of the cushion body, may be torn, and especially if the protrusion 18 is long, it is likely to be torn, resulting in a loss of workability.

(Problem that the invention aims to solve) This invention was made in view of the above points,
To provide a mold for molding a cushion body which does not cause tearing around the hole and has good workability when demolding the cushion body which has a hole for inserting a headrest stay in the longitudinal direction from one end.

(Means for solving the problem) This invention is a mold for molding a cushion body having a hole for inserting a headrest stay extending from one end in the longitudinal direction of the molded product, and in which a protrusion is inserted into the cavity. In the divided mold, the protrusion consists of a plate-shaped leg and a bead-shaped part at the tip of the protrusion, and the protrusion leg is attached to one side so that one end of the protrusion comes into contact with one side of the mold surface when the mold is closed. It is characterized in that it is erected on the mold surface of the split mold, and the bead-shaped portion is undercut with respect to the split surface.

(Function) Next, the function of this mold will be explained when molding a cushion body.

Liquid foaming material is injected into the mold cavity and the mold is closed. When the mold is closed, the protrusion hangs down from the surface of one of the divided molds, for example, the upper mold, and is located inside the cavity, and foaming is carried out in this state to form the cushion body. Therefore, a hollow portion in the shape of a protrusion is formed in the cushion body from the upper die surface. That is, a slit is formed by the protruding leg, and a hole is formed by the bead at the back of the slit. In other words,
The holes within the cushion body communicate with the outside through slits.

As a result, when the upper mold is opened, the protrusion provided on the upper mold comes out of the cushion body through the slit portion, and the cushion body can then be easily removed from the mold.

(Example) FIG. 3 is a perspective view of a main part of a cushion body 22 molded using a mold according to this invention. This cushion body 22 has a hole 24 for inserting the stay of the headrest, and a slit 2 following the hole 24.
6 is formed. The slit 26 extends to an end 28 of the cushion body 22.

FIG. 1 is a perspective view of a mold 30 for molding the cushion body 22. As shown in FIG.

This mold 30 is made up of a split mold consisting of an upper mold 32 and a lower mold 34, and has a product-shaped cavity 36 inside.
is formed. A protrusion 40 is erected on the mold surface 38a of the upper mold 32 toward the mold surface 42 of the lower mold 34,
When the mold is closed, the protrusion 40 hangs down so that one end of the protrusion 40 comes into contact with one side 42a of the mold surface. The mold surface 38 of the upper mold 32 has a stepped shape of 38a and 38b, and when the mold is closed, a side surface 38c of the stepped portion and a side surface 42a of the lower mold surface 42 are separated as shown in FIG. A protrusion 40 is provided on. The protrusion 40 consists of a plate-shaped leg 40a erected on the mold surface, and a bead-shaped portion 40b at the tip of the leg 40a. The plate-like leg portion 40a is the slit 2 of the cushion body.
6. The beaded portion 40b forms the hole 24.

FIG. 2 is a cross-sectional view of the cushion body 22 formed by injecting liquid foaming raw material into the cavity 36 of the mold 30. This cushion body 2
2 includes a protrusion 4 on the upper mold surface as shown in FIG.
0 holes 24 and slits 26 are formed. Thereafter, the upper mold 32 is opened and the cushion body 22 is removed from the mold.

The protrusions 40 are attached to the upper mold 32 when the upper mold 32 is opened.
At the same time, it rises and exits from the cushion body 22 through the slit 26. Due to the elasticity of the cushion body 22, the slit 26 easily expands when the beaded portion 40b passes through, allowing the beaded portion 40b to pass through and escape.

Thereby, the cushion body 22 can be removed from the lower mold without any hindrance. Moreover, even if the hole 24 or its vicinity is undercut,
Since the projections 40 are no longer present in the cushion body 22 at the time of demolding, the cushion body 22 can be easily deformed and demolded.

Note that the position, shape, etc. of the protrusion 40 are not limited to those shown in the drawings, and may be appropriately changed in design depending on the desired shape of the cushion body, etc.

(Effect of the invention) The mold according to this invention has a protrusion consisting of a plate-shaped leg and a beaded part at the tip thereof erected on one of the split molds, for example, the upper mold surface. A hole communicating with the outside is formed by a slit in the cushion body that is molded using a mold. As a result, when the upper mold is opened, the protrusions pass through the slit portion of the cushion body and come out of the cushion body, and subsequent demolding can be performed without any trouble. Moreover, since the cushion body is covered with a skin material or the like, the slits do not impede the appearance in any way.

[Brief explanation of the drawing]

Figures 1 to 3 relate to the embodiment of this invention; Figure 1 is a perspective view of the mold, Figure 2 is a sectional view of the mold during molding of the cushion body, and Figure 3 is a perspective view of the main parts of the cushion body. , FIGS. 4 to 6 relate to conventional examples,
FIG. 4 is a perspective view of the mold, FIG. 5 is a sectional view of the mold during demolding, and FIG. 6 is a perspective view of essential parts of the cushion body. 36... Cavity, 38a... Upper mold surface, 4
0...Protrusion, 40a...Plate-shaped leg portion, 40b...Bead-shaped portion.

Claims (1)

[Scope of utility model registration request] A mold for molding a cushion body having a hole for inserting a headrest stay extending from one end in the longitudinal direction of the molded product, the split mold having a protrusion for forming the hole provided in the cavity,
The protrusion consists of a plate-like leg and a bead-shaped part at the tip of the protrusion, and the protrusion leg is made to stand on one mold surface of one split mold so that one end of the protrusion touches one side of the mold surface when the mold is closed. A cushion body forming mold characterized in that the bead-shaped portion is undercut with respect to the dividing surface.